994116f88657a4cb5e214cee65185a1628bc3e2b
[l2tpns.git] / l2tpns.c
1 // L2TP Network Server
2 // Adrian Kennard 2002
3 // Copyright (c) 2003, 2004, 2005 Optus Internet Engineering
4 // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
5 // vim: sw=8 ts=8
6
7 char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.145 2005-10-18 07:19:28 bodea Exp $";
8
9 #include <arpa/inet.h>
10 #include <assert.h>
11 #include <errno.h>
12 #include <fcntl.h>
13 #include <linux/if_tun.h>
14 #define SYSLOG_NAMES
15 #include <syslog.h>
16 #include <malloc.h>
17 #include <math.h>
18 #include <net/route.h>
19 #include <sys/mman.h>
20 #include <netdb.h>
21 #include <netinet/in.h>
22 #include <netinet/ip6.h>
23 #include <stdarg.h>
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include <string.h>
27 #include <ctype.h>
28 #include <sys/ioctl.h>
29 #include <sys/socket.h>
30 #include <sys/stat.h>
31 #include <sys/time.h>
32 #include <sys/resource.h>
33 #include <sys/wait.h>
34 #include <linux/if.h>
35 #include <stddef.h>
36 #include <time.h>
37 #include <dlfcn.h>
38 #include <unistd.h>
39 #include <sched.h>
40 #include <sys/sysinfo.h>
41 #include <libcli.h>
42
43 #include "md5.h"
44 #include "l2tpns.h"
45 #include "cluster.h"
46 #include "plugin.h"
47 #include "ll.h"
48 #include "constants.h"
49 #include "control.h"
50 #include "util.h"
51 #include "tbf.h"
52
53 #ifdef BGP
54 #include "bgp.h"
55 #endif
56
57 // Globals
58 configt *config = NULL; // all configuration
59 int tunfd = -1; // tun interface file handle. (network device)
60 int udpfd = -1; // UDP file handle
61 int controlfd = -1; // Control signal handle
62 int clifd = -1; // Socket listening for CLI connections.
63 int daefd = -1; // Socket listening for DAE connections.
64 int snoopfd = -1; // UDP file handle for sending out intercept data
65 int *radfds = NULL; // RADIUS requests file handles
66 int ifrfd = -1; // File descriptor for routing, etc
67 int ifr6fd = -1; // File descriptor for IPv6 routing, etc
68 int rand_fd = -1; // Random data source
69 int cluster_sockfd = -1; // Intra-cluster communications socket.
70 int epollfd = -1; // event polling
71 time_t basetime = 0; // base clock
72 char hostname[1000] = ""; // us.
73 static int tunidx; // ifr_ifindex of tun device
74 static int syslog_log = 0; // are we logging to syslog
75 static FILE *log_stream = 0; // file handle for direct logging (i.e. direct into file, not via syslog).
76 uint32_t last_id = 0; // Unique ID for radius accounting
77
78 // calculated from config->l2tp_mtu
79 uint16_t MRU = 0; // PPP MRU
80 uint16_t MSS = 0; // TCP MSS
81
82 struct cli_session_actions *cli_session_actions = NULL; // Pending session changes requested by CLI
83 struct cli_tunnel_actions *cli_tunnel_actions = NULL; // Pending tunnel changes required by CLI
84
85 static void *ip_hash[256]; // Mapping from IP address to session structures.
86 struct ipv6radix {
87 int sess;
88 struct ipv6radix *branch;
89 } ipv6_hash[256]; // Mapping from IPv6 address to session structures.
90
91 // Traffic counters.
92 static uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
93 static uint32_t eth_rx = 0, eth_rx_pkt = 0;
94 uint32_t eth_tx = 0;
95
96 static uint32_t ip_pool_size = 1; // Size of the pool of addresses used for dynamic address allocation.
97 time_t time_now = 0; // Current time in seconds since epoch.
98 static char time_now_string[64] = {0}; // Current time as a string.
99 int time_changed = 0; // time_now changed
100 char main_quit = 0; // True if we're in the process of exiting.
101 char main_reload = 0; // Re-load pending
102 linked_list *loaded_plugins;
103 linked_list *plugins[MAX_PLUGIN_TYPES];
104
105 #define membersize(STRUCT, MEMBER) sizeof(((STRUCT *)0)->MEMBER)
106 #define CONFIG(NAME, MEMBER, TYPE) { NAME, offsetof(configt, MEMBER), membersize(configt, MEMBER), TYPE }
107
108 config_descriptt config_values[] = {
109 CONFIG("debug", debug, INT),
110 CONFIG("log_file", log_filename, STRING),
111 CONFIG("pid_file", pid_file, STRING),
112 CONFIG("random_device", random_device, STRING),
113 CONFIG("l2tp_secret", l2tp_secret, STRING),
114 CONFIG("l2tp_mtu", l2tp_mtu, INT),
115 CONFIG("ppp_restart_time", ppp_restart_time, INT),
116 CONFIG("ppp_max_configure", ppp_max_configure, INT),
117 CONFIG("ppp_max_failure", ppp_max_failure, INT),
118 CONFIG("primary_dns", default_dns1, IPv4),
119 CONFIG("secondary_dns", default_dns2, IPv4),
120 CONFIG("primary_radius", radiusserver[0], IPv4),
121 CONFIG("secondary_radius", radiusserver[1], IPv4),
122 CONFIG("primary_radius_port", radiusport[0], SHORT),
123 CONFIG("secondary_radius_port", radiusport[1], SHORT),
124 CONFIG("radius_accounting", radius_accounting, BOOL),
125 CONFIG("radius_interim", radius_interim, INT),
126 CONFIG("radius_secret", radiussecret, STRING),
127 CONFIG("radius_authtypes", radius_authtypes_s, STRING),
128 CONFIG("radius_dae_port", radius_dae_port, SHORT),
129 CONFIG("allow_duplicate_users", allow_duplicate_users, BOOL),
130 CONFIG("bind_address", bind_address, IPv4),
131 CONFIG("peer_address", peer_address, IPv4),
132 CONFIG("send_garp", send_garp, BOOL),
133 CONFIG("throttle_speed", rl_rate, UNSIGNED_LONG),
134 CONFIG("throttle_buckets", num_tbfs, INT),
135 CONFIG("accounting_dir", accounting_dir, STRING),
136 CONFIG("setuid", target_uid, INT),
137 CONFIG("dump_speed", dump_speed, BOOL),
138 CONFIG("multi_read_count", multi_read_count, INT),
139 CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
140 CONFIG("lock_pages", lock_pages, BOOL),
141 CONFIG("icmp_rate", icmp_rate, INT),
142 CONFIG("packet_limit", max_packets, INT),
143 CONFIG("cluster_address", cluster_address, IPv4),
144 CONFIG("cluster_interface", cluster_interface, STRING),
145 CONFIG("cluster_mcast_ttl", cluster_mcast_ttl, INT),
146 CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
147 CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
148 CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT),
149 CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
150 { NULL, 0, 0, 0 },
151 };
152
153 static char *plugin_functions[] = {
154 NULL,
155 "plugin_pre_auth",
156 "plugin_post_auth",
157 "plugin_packet_rx",
158 "plugin_packet_tx",
159 "plugin_timer",
160 "plugin_new_session",
161 "plugin_kill_session",
162 "plugin_control",
163 "plugin_radius_response",
164 "plugin_radius_reset",
165 "plugin_radius_account",
166 "plugin_become_master",
167 "plugin_new_session_master",
168 };
169
170 #define max_plugin_functions (sizeof(plugin_functions) / sizeof(char *))
171
172 // Counters for shutdown sessions
173 static sessiont shut_acct[8192];
174 static sessionidt shut_acct_n = 0;
175
176 tunnelt *tunnel = NULL; // Array of tunnel structures.
177 sessiont *session = NULL; // Array of session structures.
178 sessionlocalt *sess_local = NULL; // Array of local per-session counters.
179 radiust *radius = NULL; // Array of radius structures.
180 ippoolt *ip_address_pool = NULL; // Array of dynamic IP addresses.
181 ip_filtert *ip_filters = NULL; // Array of named filters.
182 static controlt *controlfree = 0;
183 struct Tstats *_statistics = NULL;
184 #ifdef RINGBUFFER
185 struct Tringbuffer *ringbuffer = NULL;
186 #endif
187
188 static void cache_ipmap(in_addr_t ip, int s);
189 static void uncache_ipmap(in_addr_t ip);
190 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s);
191 static void free_ip_address(sessionidt s);
192 static void dump_acct_info(int all);
193 static void sighup_handler(int sig);
194 static void shutdown_handler(int sig);
195 static void sigchild_handler(int sig);
196 static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response);
197 static void update_config(void);
198 static void read_config_file(void);
199 static void initplugins(void);
200 static int add_plugin(char *plugin_name);
201 static int remove_plugin(char *plugin_name);
202 static void plugins_done(void);
203 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
204 static tunnelidt new_tunnel(void);
205 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
206
207 // on slaves, alow BGP to withdraw cleanly before exiting
208 #define QUIT_DELAY 5
209
210 // quit actions (master)
211 #define QUIT_FAILOVER 1 // SIGTERM: exit when all control messages have been acked (for cluster failover)
212 #define QUIT_SHUTDOWN 2 // SIGQUIT: shutdown sessions/tunnels, reject new connections
213
214 // return internal time (10ths since process startup), set f if given
215 // as a side-effect sets time_now, and time_changed
216 static clockt now(double *f)
217 {
218 struct timeval t;
219 gettimeofday(&t, 0);
220 if (f) *f = t.tv_sec + t.tv_usec / 1000000.0;
221 if (t.tv_sec != time_now)
222 {
223 time_now = t.tv_sec;
224 time_changed++;
225 }
226 return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
227 }
228
229 // work out a retry time based on try number
230 // This is a straight bounded exponential backoff.
231 // Maximum re-try time is 32 seconds. (2^5).
232 clockt backoff(uint8_t try)
233 {
234 if (try > 5) try = 5; // max backoff
235 return now(NULL) + 10 * (1 << try);
236 }
237
238
239 //
240 // Log a debug message. Typically called via the LOG macro
241 //
242 void _log(int level, sessionidt s, tunnelidt t, const char *format, ...)
243 {
244 static char message[65536] = {0};
245 va_list ap;
246
247 #ifdef RINGBUFFER
248 if (ringbuffer)
249 {
250 if (++ringbuffer->tail >= RINGBUFFER_SIZE)
251 ringbuffer->tail = 0;
252 if (ringbuffer->tail == ringbuffer->head)
253 if (++ringbuffer->head >= RINGBUFFER_SIZE)
254 ringbuffer->head = 0;
255
256 ringbuffer->buffer[ringbuffer->tail].level = level;
257 ringbuffer->buffer[ringbuffer->tail].session = s;
258 ringbuffer->buffer[ringbuffer->tail].tunnel = t;
259 va_start(ap, format);
260 vsnprintf(ringbuffer->buffer[ringbuffer->tail].message, 4095, format, ap);
261 va_end(ap);
262 }
263 #endif
264
265 if (config->debug < level) return;
266
267 va_start(ap, format);
268 vsnprintf(message, sizeof(message), format, ap);
269
270 if (log_stream)
271 fprintf(log_stream, "%s %02d/%02d %s", time_now_string, t, s, message);
272 else if (syslog_log)
273 syslog(level + 2, "%02d/%02d %s", t, s, message); // We don't need LOG_EMERG or LOG_ALERT
274
275 va_end(ap);
276 }
277
278 void _log_hex(int level, const char *title, const uint8_t *data, int maxsize)
279 {
280 int i, j;
281 const uint8_t *d = data;
282
283 if (config->debug < level) return;
284
285 // No support for _log_hex to syslog
286 if (log_stream)
287 {
288 _log(level, 0, 0, "%s (%d bytes):\n", title, maxsize);
289 setvbuf(log_stream, NULL, _IOFBF, 16384);
290
291 for (i = 0; i < maxsize; )
292 {
293 fprintf(log_stream, "%4X: ", i);
294 for (j = i; j < maxsize && j < (i + 16); j++)
295 {
296 fprintf(log_stream, "%02X ", d[j]);
297 if (j == i + 7)
298 fputs(": ", log_stream);
299 }
300
301 for (; j < i + 16; j++)
302 {
303 fputs(" ", log_stream);
304 if (j == i + 7)
305 fputs(": ", log_stream);
306 }
307
308 fputs(" ", log_stream);
309 for (j = i; j < maxsize && j < (i + 16); j++)
310 {
311 if (d[j] >= 0x20 && d[j] < 0x7f && d[j] != 0x20)
312 fputc(d[j], log_stream);
313 else
314 fputc('.', log_stream);
315
316 if (j == i + 7)
317 fputs(" ", log_stream);
318 }
319
320 i = j;
321 fputs("\n", log_stream);
322 }
323
324 fflush(log_stream);
325 setbuf(log_stream, NULL);
326 }
327 }
328
329 // update a counter, accumulating 2^32 wraps
330 void increment_counter(uint32_t *counter, uint32_t *wrap, uint32_t delta)
331 {
332 uint32_t new = *counter + delta;
333 if (new < *counter)
334 (*wrap)++;
335
336 *counter = new;
337 }
338
339 // initialise the random generator
340 static void initrandom(char *source)
341 {
342 static char path[sizeof(config->random_device)] = "*undefined*";
343
344 // reinitialise only if we are forced to do so or if the config has changed
345 if (source && !strncmp(path, source, sizeof(path)))
346 return;
347
348 // close previous source, if any
349 if (rand_fd >= 0)
350 close(rand_fd);
351
352 rand_fd = -1;
353
354 if (source)
355 {
356 // register changes
357 snprintf(path, sizeof(path), "%s", source);
358
359 if (*path == '/')
360 {
361 rand_fd = open(path, O_RDONLY|O_NONBLOCK);
362 if (rand_fd < 0)
363 LOG(0, 0, 0, "Error opening the random device %s: %s\n",
364 path, strerror(errno));
365 }
366 }
367 }
368
369 // fill buffer with random data
370 void random_data(uint8_t *buf, int len)
371 {
372 int n = 0;
373
374 CSTAT(random_data);
375 if (rand_fd >= 0)
376 {
377 n = read(rand_fd, buf, len);
378 if (n >= len) return;
379 if (n < 0)
380 {
381 if (errno != EAGAIN)
382 {
383 LOG(0, 0, 0, "Error reading from random source: %s\n",
384 strerror(errno));
385
386 // fall back to rand()
387 initrandom(NULL);
388 }
389
390 n = 0;
391 }
392 }
393
394 // append missing data
395 while (n < len)
396 // not using the low order bits from the prng stream
397 buf[n++] = (rand() >> 4) & 0xff;
398 }
399
400 // Add a route
401 //
402 // This adds it to the routing table, advertises it
403 // via BGP if enabled, and stuffs it into the
404 // 'sessionbyip' cache.
405 //
406 // 'ip' and 'mask' must be in _host_ order.
407 //
408 static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, int add)
409 {
410 struct rtentry r;
411 int i;
412
413 if (!mask) mask = 0xffffffff;
414
415 ip &= mask; // Force the ip to be the first one in the route.
416
417 memset(&r, 0, sizeof(r));
418 r.rt_dev = config->tundevice;
419 r.rt_dst.sa_family = AF_INET;
420 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(ip);
421 r.rt_gateway.sa_family = AF_INET;
422 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr) = htonl(gw);
423 r.rt_genmask.sa_family = AF_INET;
424 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
425 r.rt_flags = (RTF_UP | RTF_STATIC);
426 if (gw)
427 r.rt_flags |= RTF_GATEWAY;
428 else if (mask == 0xffffffff)
429 r.rt_flags |= RTF_HOST;
430
431 LOG(1, s, 0, "Route %s %s/%s%s%s\n", add ? "add" : "del",
432 fmtaddr(htonl(ip), 0), fmtaddr(htonl(mask), 1),
433 gw ? " via" : "", gw ? fmtaddr(htonl(gw), 2) : "");
434
435 if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0)
436 LOG(0, 0, 0, "routeset() error in ioctl: %s\n", strerror(errno));
437
438 #ifdef BGP
439 if (add)
440 bgp_add_route(htonl(ip), htonl(mask));
441 else
442 bgp_del_route(htonl(ip), htonl(mask));
443 #endif /* BGP */
444
445 // Add/Remove the IPs to the 'sessionbyip' cache.
446 // Note that we add the zero address in the case of
447 // a network route. Roll on CIDR.
448
449 // Note that 's == 0' implies this is the address pool.
450 // We still cache it here, because it will pre-fill
451 // the malloc'ed tree.
452
453 if (s)
454 {
455 if (!add) // Are we deleting a route?
456 s = 0; // Caching the session as '0' is the same as uncaching.
457
458 for (i = ip; (i&mask) == (ip&mask) ; ++i)
459 cache_ipmap(i, s);
460 }
461 }
462
463 void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add)
464 {
465 struct in6_rtmsg rt;
466 char ipv6addr[INET6_ADDRSTRLEN];
467
468 if (ifr6fd < 0)
469 {
470 LOG(0, 0, 0, "Asked to set IPv6 route, but IPv6 not setup.\n");
471 return;
472 }
473
474 memset(&rt, 0, sizeof(rt));
475
476 memcpy(&rt.rtmsg_dst, &ip, sizeof(struct in6_addr));
477 rt.rtmsg_dst_len = prefixlen;
478 rt.rtmsg_metric = 1;
479 rt.rtmsg_flags = RTF_UP;
480 rt.rtmsg_ifindex = tunidx;
481
482 LOG(1, 0, 0, "Route %s %s/%d\n",
483 add ? "add" : "del",
484 inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN),
485 prefixlen);
486
487 if (ioctl(ifr6fd, add ? SIOCADDRT : SIOCDELRT, (void *) &rt) < 0)
488 LOG(0, 0, 0, "route6set() error in ioctl: %s\n",
489 strerror(errno));
490
491 // FIXME: need to add BGP routing (RFC2858)
492
493 if (s)
494 {
495 if (!add) // Are we deleting a route?
496 s = 0; // Caching the session as '0' is the same as uncaching.
497
498 cache_ipv6map(ip, prefixlen, s);
499 }
500
501 return;
502 }
503
504 // defined in linux/ipv6.h, but tricky to include from user-space
505 // TODO: move routing to use netlink rather than ioctl
506 struct in6_ifreq {
507 struct in6_addr ifr6_addr;
508 __u32 ifr6_prefixlen;
509 unsigned int ifr6_ifindex;
510 };
511
512 //
513 // Set up TUN interface
514 static void inittun(void)
515 {
516 struct ifreq ifr;
517 struct in6_ifreq ifr6;
518 struct sockaddr_in sin = {0};
519 memset(&ifr, 0, sizeof(ifr));
520 ifr.ifr_flags = IFF_TUN;
521
522 tunfd = open(TUNDEVICE, O_RDWR);
523 if (tunfd < 0)
524 { // fatal
525 LOG(0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
526 exit(1);
527 }
528 {
529 int flags = fcntl(tunfd, F_GETFL, 0);
530 fcntl(tunfd, F_SETFL, flags | O_NONBLOCK);
531 }
532 if (ioctl(tunfd, TUNSETIFF, (void *) &ifr) < 0)
533 {
534 LOG(0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
535 exit(1);
536 }
537 assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
538 strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
539 ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
540
541 sin.sin_family = AF_INET;
542 sin.sin_addr.s_addr = config->bind_address ? config->bind_address : 0x01010101; // 1.1.1.1
543 memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));
544
545 if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0)
546 {
547 LOG(0, 0, 0, "Error setting tun address: %s\n", strerror(errno));
548 exit(1);
549 }
550 /* Bump up the qlen to deal with bursts from the network */
551 ifr.ifr_qlen = 1000;
552 if (ioctl(ifrfd, SIOCSIFTXQLEN, (void *) &ifr) < 0)
553 {
554 LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
555 exit(1);
556 }
557 ifr.ifr_flags = IFF_UP;
558 if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
559 {
560 LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
561 exit(1);
562 }
563 if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
564 {
565 LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
566 exit(1);
567 }
568 tunidx = ifr.ifr_ifindex;
569
570 // Only setup IPv6 on the tun device if we have a configured prefix
571 if (config->ipv6_prefix.s6_addr[0]) {
572 ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0);
573
574 // Link local address is FE80::1
575 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
576 ifr6.ifr6_addr.s6_addr[0] = 0xFE;
577 ifr6.ifr6_addr.s6_addr[1] = 0x80;
578 ifr6.ifr6_addr.s6_addr[15] = 1;
579 ifr6.ifr6_prefixlen = 64;
580 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
581 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
582 {
583 LOG(0, 0, 0, "Error setting tun IPv6 link local address:"
584 " %s\n", strerror(errno));
585 }
586
587 // Global address is prefix::1
588 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
589 ifr6.ifr6_addr = config->ipv6_prefix;
590 ifr6.ifr6_addr.s6_addr[15] = 1;
591 ifr6.ifr6_prefixlen = 64;
592 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
593 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
594 {
595 LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n",
596 strerror(errno));
597 }
598 }
599 }
600
601 // set up UDP ports
602 static void initudp(void)
603 {
604 int on = 1;
605 struct sockaddr_in addr;
606
607 // Tunnel
608 memset(&addr, 0, sizeof(addr));
609 addr.sin_family = AF_INET;
610 addr.sin_port = htons(L2TPPORT);
611 addr.sin_addr.s_addr = config->bind_address;
612 udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
613 setsockopt(udpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
614 {
615 int flags = fcntl(udpfd, F_GETFL, 0);
616 fcntl(udpfd, F_SETFL, flags | O_NONBLOCK);
617 }
618 if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
619 {
620 LOG(0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
621 exit(1);
622 }
623
624 // Control
625 memset(&addr, 0, sizeof(addr));
626 addr.sin_family = AF_INET;
627 addr.sin_port = htons(NSCTL_PORT);
628 controlfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
629 setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
630 if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
631 {
632 LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
633 exit(1);
634 }
635
636 // Dynamic Authorization Extensions to RADIUS
637 memset(&addr, 0, sizeof(addr));
638 addr.sin_family = AF_INET;
639 addr.sin_port = htons(config->radius_dae_port);
640 daefd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
641 setsockopt(daefd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
642 if (bind(daefd, (void *) &addr, sizeof(addr)) < 0)
643 {
644 LOG(0, 0, 0, "Error in DAE bind: %s\n", strerror(errno));
645 exit(1);
646 }
647
648 // Intercept
649 snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
650 }
651
652 //
653 // Find session by IP, < 1 for not found
654 //
655 // Confusingly enough, this 'ip' must be
656 // in _network_ order. This being the common
657 // case when looking it up from IP packet headers.
658 //
659 // We actually use this cache for two things.
660 // #1. For used IP addresses, this maps to the
661 // session ID that it's used by.
662 // #2. For un-used IP addresses, this maps to the
663 // index into the pool table that contains that
664 // IP address.
665 //
666
667 static int lookup_ipmap(in_addr_t ip)
668 {
669 uint8_t *a = (uint8_t *) &ip;
670 uint8_t **d = (uint8_t **) ip_hash;
671
672 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
673 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
674 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
675
676 return (int) (intptr_t) d[(size_t) *a];
677 }
678
679 static int lookup_ipv6map(struct in6_addr ip)
680 {
681 struct ipv6radix *curnode;
682 int i;
683 int s;
684 char ipv6addr[INET6_ADDRSTRLEN];
685
686 curnode = &ipv6_hash[ip.s6_addr[0]];
687 i = 1;
688 s = curnode->sess;
689
690 while (s == 0 && i < 15 && curnode->branch != NULL)
691 {
692 curnode = &curnode->branch[ip.s6_addr[i]];
693 s = curnode->sess;
694 i++;
695 }
696
697 LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
698 inet_ntop(AF_INET6, &ip, ipv6addr,
699 INET6_ADDRSTRLEN),
700 s);
701
702 return s;
703 }
704
705 sessionidt sessionbyip(in_addr_t ip)
706 {
707 int s = lookup_ipmap(ip);
708 CSTAT(sessionbyip);
709
710 if (s > 0 && s < MAXSESSION && session[s].opened)
711 return (sessionidt) s;
712
713 return 0;
714 }
715
716 sessionidt sessionbyipv6(struct in6_addr ip)
717 {
718 int s;
719 CSTAT(sessionbyipv6);
720
721 if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
722 (ip.s6_addr[0] == 0xFE &&
723 ip.s6_addr[1] == 0x80 &&
724 ip.s6_addr16[1] == 0 &&
725 ip.s6_addr16[2] == 0 &&
726 ip.s6_addr16[3] == 0)) {
727 s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
728 } else {
729 s = lookup_ipv6map(ip);
730 }
731
732 if (s > 0 && s < MAXSESSION && session[s].opened)
733 return s;
734
735 return 0;
736 }
737
738 //
739 // Take an IP address in HOST byte order and
740 // add it to the sessionid by IP cache.
741 //
742 // (It's actually cached in network order)
743 //
744 static void cache_ipmap(in_addr_t ip, int s)
745 {
746 in_addr_t nip = htonl(ip); // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
747 uint8_t *a = (uint8_t *) &nip;
748 uint8_t **d = (uint8_t **) ip_hash;
749 int i;
750
751 for (i = 0; i < 3; i++)
752 {
753 if (!d[(size_t) a[i]])
754 {
755 if (!(d[(size_t) a[i]] = calloc(256, sizeof(void *))))
756 return;
757 }
758
759 d = (uint8_t **) d[(size_t) a[i]];
760 }
761
762 d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
763
764 if (s > 0)
765 LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
766
767 else if (s == 0)
768 LOG(4, 0, 0, "Un-caching ip address %s\n", fmtaddr(nip, 0));
769 // else a map to an ip pool index.
770 }
771
772 static void uncache_ipmap(in_addr_t ip)
773 {
774 cache_ipmap(ip, 0); // Assign it to the NULL session.
775 }
776
777 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
778 {
779 int i;
780 int bytes;
781 struct ipv6radix *curnode;
782 char ipv6addr[INET6_ADDRSTRLEN];
783
784 curnode = &ipv6_hash[ip.s6_addr[0]];
785
786 bytes = prefixlen >> 3;
787 i = 1;
788 while (i < bytes) {
789 if (curnode->branch == NULL)
790 {
791 if (!(curnode->branch = calloc(256,
792 sizeof (struct ipv6radix))))
793 return;
794 }
795 curnode = &curnode->branch[ip.s6_addr[i]];
796 i++;
797 }
798
799 curnode->sess = s;
800
801 if (s > 0)
802 LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
803 inet_ntop(AF_INET6, &ip, ipv6addr,
804 INET6_ADDRSTRLEN),
805 prefixlen);
806 else if (s == 0)
807 LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
808 inet_ntop(AF_INET6, &ip, ipv6addr,
809 INET6_ADDRSTRLEN),
810 prefixlen);
811 }
812
813 //
814 // CLI list to dump current ipcache.
815 //
816 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
817 {
818 char **d = (char **) ip_hash, **e, **f, **g;
819 int i, j, k, l;
820 int count = 0;
821
822 if (CLI_HELP_REQUESTED)
823 return CLI_HELP_NO_ARGS;
824
825 cli_print(cli, "%7s %s", "Sess#", "IP Address");
826
827 for (i = 0; i < 256; ++i)
828 {
829 if (!d[i])
830 continue;
831 e = (char **) d[i];
832 for (j = 0; j < 256; ++j)
833 {
834 if (!e[j])
835 continue;
836 f = (char **) e[j];
837 for (k = 0; k < 256; ++k)
838 {
839 if (!f[k])
840 continue;
841 g = (char **)f[k];
842 for (l = 0; l < 256; ++l)
843 {
844 if (!g[l])
845 continue;
846 cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
847 ++count;
848 }
849 }
850 }
851 }
852 cli_print(cli, "%d entries in cache", count);
853 return CLI_OK;
854 }
855
856
857 // Find session by username, 0 for not found
858 // walled garden users aren't authenticated, so the username is
859 // reasonably useless. Ignore them to avoid incorrect actions
860 //
861 // This is VERY inefficent. Don't call it often. :)
862 //
863 sessionidt sessionbyuser(char *username)
864 {
865 int s;
866 CSTAT(sessionbyuser);
867
868 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
869 {
870 if (!session[s].opened)
871 continue;
872
873 if (session[s].walled_garden)
874 continue; // Skip walled garden users.
875
876 if (!strncmp(session[s].user, username, 128))
877 return s;
878
879 }
880 return 0; // Not found.
881 }
882
883 void send_garp(in_addr_t ip)
884 {
885 int s;
886 struct ifreq ifr;
887 uint8_t mac[6];
888
889 s = socket(PF_INET, SOCK_DGRAM, 0);
890 if (s < 0)
891 {
892 LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
893 return;
894 }
895 memset(&ifr, 0, sizeof(ifr));
896 strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
897 if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
898 {
899 LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
900 close(s);
901 return;
902 }
903 memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
904 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
905 {
906 LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
907 close(s);
908 return;
909 }
910 close(s);
911 sendarp(ifr.ifr_ifindex, mac, ip);
912 }
913
914 static sessiont *sessiontbysessionidt(sessionidt s)
915 {
916 if (!s || s >= MAXSESSION) return NULL;
917 return &session[s];
918 }
919
920 static sessionidt sessionidtbysessiont(sessiont *s)
921 {
922 sessionidt val = s-session;
923 if (s < session || val >= MAXSESSION) return 0;
924 return val;
925 }
926
927 // actually send a control message for a specific tunnel
928 void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
929 {
930 struct sockaddr_in addr;
931
932 CSTAT(tunnelsend);
933
934 if (!t)
935 {
936 static int backtrace_count = 0;
937 LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
938 STAT(tunnel_tx_errors);
939 log_backtrace(backtrace_count, 5)
940 return;
941 }
942
943 if (!tunnel[t].ip)
944 {
945 static int backtrace_count = 0;
946 LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
947 log_backtrace(backtrace_count, 5)
948 STAT(tunnel_tx_errors);
949 return;
950 }
951
952 memset(&addr, 0, sizeof(addr));
953 addr.sin_family = AF_INET;
954 *(uint32_t *) & addr.sin_addr = htonl(tunnel[t].ip);
955 addr.sin_port = htons(tunnel[t].port);
956
957 // sequence expected, if sequence in message
958 if (*buf & 0x08) *(uint16_t *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
959
960 // If this is a control message, deal with retries
961 if (*buf & 0x80)
962 {
963 tunnel[t].last = time_now; // control message sent
964 tunnel[t].retry = backoff(tunnel[t].try); // when to resend
965 if (tunnel[t].try)
966 {
967 STAT(tunnel_retries);
968 LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
969 }
970 }
971
972 if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
973 {
974 LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
975 strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
976 STAT(tunnel_tx_errors);
977 return;
978 }
979
980 LOG_HEX(5, "Send Tunnel Data", buf, l);
981 STAT(tunnel_tx_packets);
982 INC_STAT(tunnel_tx_bytes, l);
983 }
984
985 //
986 // Tiny helper function to write data to
987 // the 'tun' device.
988 //
989 int tun_write(uint8_t * data, int size)
990 {
991 return write(tunfd, data, size);
992 }
993
994 // adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
995 void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
996 {
997 int d = (tcp[12] >> 4) * 4;
998 uint8_t *mss = 0;
999 uint8_t *opts;
1000 uint8_t *data;
1001 uint16_t orig;
1002 uint32_t sum;
1003
1004 if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
1005 return;
1006
1007 if (tcp + d > buf + len) // short?
1008 return;
1009
1010 opts = tcp + 20;
1011 data = tcp + d;
1012
1013 while (opts < data)
1014 {
1015 if (*opts == 2 && opts[1] == 4) // mss option (2), length 4
1016 {
1017 mss = opts + 2;
1018 if (mss + 2 > data) return; // short?
1019 break;
1020 }
1021
1022 if (*opts == 0) return; // end of options
1023 if (*opts == 1 || !opts[1]) // no op (one byte), or no length (prevent loop)
1024 opts++;
1025 else
1026 opts += opts[1]; // skip over option
1027 }
1028
1029 if (!mss) return; // not found
1030 orig = ntohs(*(uint16_t *) mss);
1031
1032 if (orig <= MSS) return; // mss OK
1033
1034 LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s: adjusted mss from %u to %u\n",
1035 fmtaddr(*(in_addr_t *) (buf + 12), 0), ntohs(*(uint16_t *) tcp),
1036 fmtaddr(*(in_addr_t *) (buf + 16), 1), ntohs(*(uint16_t *) (tcp + 2)),
1037 (tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "", orig, MSS);
1038
1039 // set mss
1040 *(int16_t *) mss = htons(MSS);
1041
1042 // adjust checksum (see rfc1141)
1043 sum = orig + (~MSS & 0xffff);
1044 sum += ntohs(*(uint16_t *) (tcp + 16));
1045 sum = (sum & 0xffff) + (sum >> 16);
1046 *(uint16_t *) (tcp + 16) = htons(sum);
1047 }
1048
1049 // process outgoing (to tunnel) IP
1050 //
1051 static void processipout(uint8_t *buf, int len)
1052 {
1053 sessionidt s;
1054 sessiont *sp;
1055 tunnelidt t;
1056 in_addr_t ip;
1057
1058 uint8_t *data = buf; // Keep a copy of the originals.
1059 int size = len;
1060
1061 uint8_t b[MAXETHER + 20];
1062
1063 CSTAT(processipout);
1064
1065 if (len < MIN_IP_SIZE)
1066 {
1067 LOG(1, 0, 0, "Short IP, %d bytes\n", len);
1068 STAT(tun_rx_errors);
1069 return;
1070 }
1071 if (len >= MAXETHER)
1072 {
1073 LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
1074 STAT(tun_rx_errors);
1075 return;
1076 }
1077
1078 // Skip the tun header
1079 buf += 4;
1080 len -= 4;
1081
1082 // Got an IP header now
1083 if (*(uint8_t *)(buf) >> 4 != 4)
1084 {
1085 LOG(1, 0, 0, "IP: Don't understand anything except IPv4\n");
1086 return;
1087 }
1088
1089 ip = *(uint32_t *)(buf + 16);
1090 if (!(s = sessionbyip(ip)))
1091 {
1092 // Is this a packet for a session that doesn't exist?
1093 static int rate = 0; // Number of ICMP packets we've sent this second.
1094 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1095
1096 if (last != time_now)
1097 {
1098 last = time_now;
1099 rate = 0;
1100 }
1101
1102 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1103 {
1104 LOG(4, 0, 0, "IP: Sending ICMP host unreachable to %s\n", fmtaddr(*(in_addr_t *)(buf + 12), 0));
1105 host_unreachable(*(in_addr_t *)(buf + 12), *(uint16_t *)(buf + 4),
1106 config->bind_address ? config->bind_address : my_address, buf, len);
1107 }
1108 return;
1109 }
1110 t = session[s].tunnel;
1111 sp = &session[s];
1112
1113 // DoS prevention: enforce a maximum number of packets per 0.1s for a session
1114 if (config->max_packets > 0)
1115 {
1116 if (sess_local[s].last_packet_out == TIME)
1117 {
1118 int max = config->max_packets;
1119
1120 // All packets for throttled sessions are handled by the
1121 // master, so further limit by using the throttle rate.
1122 // A bit of a kludge, since throttle rate is in kbps,
1123 // but should still be generous given our average DSL
1124 // packet size is 200 bytes: a limit of 28kbps equates
1125 // to around 180 packets per second.
1126 if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
1127 max = sp->throttle_out;
1128
1129 if (++sess_local[s].packets_out > max)
1130 {
1131 sess_local[s].packets_dropped++;
1132 return;
1133 }
1134 }
1135 else
1136 {
1137 if (sess_local[s].packets_dropped)
1138 {
1139 INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
1140 LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
1141 sess_local[s].packets_dropped, sess_local[s].packets_out,
1142 fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
1143 sp->user);
1144 }
1145
1146 sess_local[s].last_packet_out = TIME;
1147 sess_local[s].packets_out = 1;
1148 sess_local[s].packets_dropped = 0;
1149 }
1150 }
1151
1152 // run access-list if any
1153 if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
1154 return;
1155
1156 // adjust MSS on SYN and SYN,ACK packets with options
1157 if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
1158 {
1159 int ihl = (buf[0] & 0xf) * 4; // length of IP header
1160 if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
1161 adjust_tcp_mss(s, t, buf, len, buf + ihl);
1162 }
1163
1164 if (sp->tbf_out)
1165 {
1166 // Are we throttling this session?
1167 if (config->cluster_iam_master)
1168 tbf_queue_packet(sp->tbf_out, data, size);
1169 else
1170 master_throttle_packet(sp->tbf_out, data, size);
1171 return;
1172 }
1173 else if (sp->walled_garden && !config->cluster_iam_master)
1174 {
1175 // We are walled-gardening this
1176 master_garden_packet(s, data, size);
1177 return;
1178 }
1179
1180 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1181
1182 // Add on L2TP header
1183 {
1184 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
1185 if (!p) return;
1186 tunnelsend(b, len + (p-b), t); // send it...
1187 }
1188
1189 // Snooping this session, send it to intercept box
1190 if (sp->snoop_ip && sp->snoop_port)
1191 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1192
1193 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1194 sp->cout_delta += len;
1195 sp->pout++;
1196 udp_tx += len;
1197
1198 sess_local[s].cout += len; // To send to master..
1199 sess_local[s].pout++;
1200 }
1201
1202 // process outgoing (to tunnel) IPv6
1203 //
1204 static void processipv6out(uint8_t * buf, int len)
1205 {
1206 sessionidt s;
1207 sessiont *sp;
1208 tunnelidt t;
1209 in_addr_t ip;
1210 struct in6_addr ip6;
1211
1212 uint8_t *data = buf; // Keep a copy of the originals.
1213 int size = len;
1214
1215 uint8_t b[MAXETHER + 20];
1216
1217 CSTAT(processipv6out);
1218
1219 if (len < MIN_IP_SIZE)
1220 {
1221 LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
1222 STAT(tunnel_tx_errors);
1223 return;
1224 }
1225 if (len >= MAXETHER)
1226 {
1227 LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
1228 STAT(tunnel_tx_errors);
1229 return;
1230 }
1231
1232 // Skip the tun header
1233 buf += 4;
1234 len -= 4;
1235
1236 // Got an IP header now
1237 if (*(uint8_t *)(buf) >> 4 != 6)
1238 {
1239 LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
1240 return;
1241 }
1242
1243 ip6 = *(struct in6_addr *)(buf+24);
1244 s = sessionbyipv6(ip6);
1245
1246 if (s == 0)
1247 {
1248 ip = *(uint32_t *)(buf + 32);
1249 s = sessionbyip(ip);
1250 }
1251
1252 if (s == 0)
1253 {
1254 // Is this a packet for a session that doesn't exist?
1255 static int rate = 0; // Number of ICMP packets we've sent this second.
1256 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1257
1258 if (last != time_now)
1259 {
1260 last = time_now;
1261 rate = 0;
1262 }
1263
1264 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1265 {
1266 // FIXME: Should send icmp6 host unreachable
1267 }
1268 return;
1269 }
1270 t = session[s].tunnel;
1271 sp = &session[s];
1272
1273 // FIXME: add DoS prevention/filters?
1274
1275 if (sp->tbf_out)
1276 {
1277 // Are we throttling this session?
1278 if (config->cluster_iam_master)
1279 tbf_queue_packet(sp->tbf_out, data, size);
1280 else
1281 master_throttle_packet(sp->tbf_out, data, size);
1282 return;
1283 }
1284 else if (sp->walled_garden && !config->cluster_iam_master)
1285 {
1286 // We are walled-gardening this
1287 master_garden_packet(s, data, size);
1288 return;
1289 }
1290
1291 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1292
1293 // Add on L2TP header
1294 {
1295 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIPV6);
1296 if (!p) return;
1297 tunnelsend(b, len + (p-b), t); // send it...
1298 }
1299
1300 // Snooping this session, send it to intercept box
1301 if (sp->snoop_ip && sp->snoop_port)
1302 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1303
1304 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1305 sp->cout_delta += len;
1306 sp->pout++;
1307 udp_tx += len;
1308
1309 sess_local[s].cout += len; // To send to master..
1310 sess_local[s].pout++;
1311 }
1312
1313 //
1314 // Helper routine for the TBF filters.
1315 // Used to send queued data in to the user!
1316 //
1317 static void send_ipout(sessionidt s, uint8_t *buf, int len)
1318 {
1319 sessiont *sp;
1320 tunnelidt t;
1321 in_addr_t ip;
1322
1323 uint8_t b[MAXETHER + 20];
1324
1325 if (len < 0 || len > MAXETHER)
1326 {
1327 LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
1328 return;
1329 }
1330
1331 // Skip the tun header
1332 buf += 4;
1333 len -= 4;
1334
1335 ip = *(in_addr_t *)(buf + 16);
1336
1337 if (!session[s].ip)
1338 return;
1339
1340 t = session[s].tunnel;
1341 sp = &session[s];
1342
1343 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1344
1345 // Add on L2TP header
1346 {
1347 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
1348 if (!p) return;
1349 tunnelsend(b, len + (p-b), t); // send it...
1350 }
1351
1352 // Snooping this session.
1353 if (sp->snoop_ip && sp->snoop_port)
1354 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1355
1356 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1357 sp->cout_delta += len;
1358 sp->pout++;
1359 udp_tx += len;
1360
1361 sess_local[s].cout += len; // To send to master..
1362 sess_local[s].pout++;
1363 }
1364
1365 // add an AVP (16 bit)
1366 static void control16(controlt * c, uint16_t avp, uint16_t val, uint8_t m)
1367 {
1368 uint16_t l = (m ? 0x8008 : 0x0008);
1369 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1370 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1371 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1372 *(uint16_t *) (c->buf + c->length + 6) = htons(val);
1373 c->length += 8;
1374 }
1375
1376 // add an AVP (32 bit)
1377 static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
1378 {
1379 uint16_t l = (m ? 0x800A : 0x000A);
1380 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1381 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1382 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1383 *(uint32_t *) (c->buf + c->length + 6) = htonl(val);
1384 c->length += 10;
1385 }
1386
1387 // add an AVP (string)
1388 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
1389 {
1390 uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
1391 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1392 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1393 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1394 memcpy(c->buf + c->length + 6, val, strlen(val));
1395 c->length += 6 + strlen(val);
1396 }
1397
1398 // add a binary AVP
1399 static void controlb(controlt * c, uint16_t avp, uint8_t *val, unsigned int len, uint8_t m)
1400 {
1401 uint16_t l = ((m ? 0x8000 : 0) + len + 6);
1402 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1403 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1404 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1405 memcpy(c->buf + c->length + 6, val, len);
1406 c->length += 6 + len;
1407 }
1408
1409 // new control connection
1410 static controlt *controlnew(uint16_t mtype)
1411 {
1412 controlt *c;
1413 if (!controlfree)
1414 c = malloc(sizeof(controlt));
1415 else
1416 {
1417 c = controlfree;
1418 controlfree = c->next;
1419 }
1420 assert(c);
1421 c->next = 0;
1422 *(uint16_t *) (c->buf + 0) = htons(0xC802); // flags/ver
1423 c->length = 12;
1424 control16(c, 0, mtype, 1);
1425 return c;
1426 }
1427
1428 // send zero block if nothing is waiting
1429 // (ZLB send).
1430 static void controlnull(tunnelidt t)
1431 {
1432 uint8_t buf[12];
1433 if (tunnel[t].controlc) // Messages queued; They will carry the ack.
1434 return;
1435
1436 *(uint16_t *) (buf + 0) = htons(0xC802); // flags/ver
1437 *(uint16_t *) (buf + 2) = htons(12); // length
1438 *(uint16_t *) (buf + 4) = htons(tunnel[t].far); // tunnel
1439 *(uint16_t *) (buf + 6) = htons(0); // session
1440 *(uint16_t *) (buf + 8) = htons(tunnel[t].ns); // sequence
1441 *(uint16_t *) (buf + 10) = htons(tunnel[t].nr); // sequence
1442 tunnelsend(buf, 12, t);
1443 }
1444
1445 // add a control message to a tunnel, and send if within window
1446 static void controladd(controlt *c, sessionidt far, tunnelidt t)
1447 {
1448 *(uint16_t *) (c->buf + 2) = htons(c->length); // length
1449 *(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
1450 *(uint16_t *) (c->buf + 6) = htons(far); // session
1451 *(uint16_t *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
1452 tunnel[t].ns++; // advance sequence
1453 // link in message in to queue
1454 if (tunnel[t].controlc)
1455 tunnel[t].controle->next = c;
1456 else
1457 tunnel[t].controls = c;
1458
1459 tunnel[t].controle = c;
1460 tunnel[t].controlc++;
1461
1462 // send now if space in window
1463 if (tunnel[t].controlc <= tunnel[t].window)
1464 {
1465 tunnel[t].try = 0; // first send
1466 tunnelsend(c->buf, c->length, t);
1467 }
1468 }
1469
1470 //
1471 // Throttle or Unthrottle a session
1472 //
1473 // Throttle the data from/to through a session to no more than
1474 // 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
1475 // user).
1476 //
1477 // If either value is -1, the current value is retained for that
1478 // direction.
1479 //
1480 void throttle_session(sessionidt s, int rate_in, int rate_out)
1481 {
1482 if (!session[s].opened)
1483 return; // No-one home.
1484
1485 if (!*session[s].user)
1486 return; // User not logged in
1487
1488 if (rate_in >= 0)
1489 {
1490 int bytes = rate_in * 1024 / 8; // kbits to bytes
1491 if (session[s].tbf_in)
1492 free_tbf(session[s].tbf_in);
1493
1494 if (rate_in > 0)
1495 session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
1496 else
1497 session[s].tbf_in = 0;
1498
1499 session[s].throttle_in = rate_in;
1500 }
1501
1502 if (rate_out >= 0)
1503 {
1504 int bytes = rate_out * 1024 / 8;
1505 if (session[s].tbf_out)
1506 free_tbf(session[s].tbf_out);
1507
1508 if (rate_out > 0)
1509 session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
1510 else
1511 session[s].tbf_out = 0;
1512
1513 session[s].throttle_out = rate_out;
1514 }
1515 }
1516
1517 // add/remove filters from session (-1 = no change)
1518 void filter_session(sessionidt s, int filter_in, int filter_out)
1519 {
1520 if (!session[s].opened)
1521 return; // No-one home.
1522
1523 if (!*session[s].user)
1524 return; // User not logged in
1525
1526 // paranoia
1527 if (filter_in > MAXFILTER) filter_in = -1;
1528 if (filter_out > MAXFILTER) filter_out = -1;
1529 if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
1530 if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
1531
1532 if (filter_in >= 0)
1533 {
1534 if (session[s].filter_in)
1535 ip_filters[session[s].filter_in - 1].used--;
1536
1537 if (filter_in > 0)
1538 ip_filters[filter_in - 1].used++;
1539
1540 session[s].filter_in = filter_in;
1541 }
1542
1543 if (filter_out >= 0)
1544 {
1545 if (session[s].filter_out)
1546 ip_filters[session[s].filter_out - 1].used--;
1547
1548 if (filter_out > 0)
1549 ip_filters[filter_out - 1].used++;
1550
1551 session[s].filter_out = filter_out;
1552 }
1553 }
1554
1555 // start tidy shutdown of session
1556 void sessionshutdown(sessionidt s, char *reason, int result, int error)
1557 {
1558 int walled_garden = session[s].walled_garden;
1559
1560
1561 CSTAT(sessionshutdown);
1562
1563 if (!session[s].opened)
1564 {
1565 LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
1566 return; // not a live session
1567 }
1568
1569 if (!session[s].die)
1570 {
1571 struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
1572 LOG(2, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
1573 run_plugins(PLUGIN_KILL_SESSION, &data);
1574 }
1575
1576 if (session[s].ip && !walled_garden && !session[s].die)
1577 {
1578 // RADIUS Stop message
1579 uint16_t r = radiusnew(s);
1580 if (r)
1581 {
1582 // stop, if not already trying
1583 if (radius[r].state != RADIUSSTOP)
1584 radiussend(r, RADIUSSTOP);
1585 }
1586 else
1587 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
1588
1589 // Save counters to dump to accounting file
1590 if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
1591 memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
1592 }
1593
1594 if (session[s].ip)
1595 { // IP allocated, clear and unroute
1596 int r;
1597 int routed = 0;
1598 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
1599 {
1600 if ((session[s].ip & session[s].route[r].mask) ==
1601 (session[s].route[r].ip & session[s].route[r].mask))
1602 routed++;
1603
1604 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
1605 session[s].route[r].ip = 0;
1606 }
1607
1608 if (session[s].ip_pool_index == -1) // static ip
1609 {
1610 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
1611 session[s].ip = 0;
1612 }
1613 else
1614 free_ip_address(s);
1615
1616 // unroute IPv6, if setup
1617 if (session[s].ppp.ipv6cp == Opened && session[s].ipv6prefixlen)
1618 route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
1619 }
1620
1621 if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
1622 throttle_session(s, 0, 0);
1623
1624 if (result)
1625 { // Send CDN
1626 controlt *c = controlnew(14); // sending CDN
1627 if (error)
1628 {
1629 uint8_t buf[4];
1630 *(uint16_t *) buf = htons(result);
1631 *(uint16_t *) (buf+2) = htons(error);
1632 controlb(c, 1, buf, 4, 1);
1633 }
1634 else
1635 control16(c, 1, result, 1);
1636
1637 control16(c, 14, s, 1); // assigned session (our end)
1638 controladd(c, session[s].far, session[s].tunnel); // send the message
1639 }
1640
1641 if (!session[s].die)
1642 session[s].die = TIME + 150; // Clean up in 15 seconds
1643
1644 // update filter refcounts
1645 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1646 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1647
1648 // clear PPP state
1649 memset(&session[s].ppp, 0, sizeof(session[s].ppp));
1650 sess_local[s].lcp.restart = 0;
1651 sess_local[s].ipcp.restart = 0;
1652 sess_local[s].ipv6cp.restart = 0;
1653 sess_local[s].ccp.restart = 0;
1654
1655 cluster_send_session(s);
1656 }
1657
1658 void sendipcp(sessionidt s, tunnelidt t)
1659 {
1660 uint8_t buf[MAXETHER];
1661 uint8_t *q;
1662
1663 CSTAT(sendipcp);
1664 LOG(3, s, t, "IPCP: send ConfigReq\n");
1665
1666 if (!session[s].unique_id)
1667 {
1668 if (!++last_id) ++last_id; // skip zero
1669 session[s].unique_id = last_id;
1670 }
1671
1672 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP);
1673 if (!q) return;
1674
1675 *q = ConfigReq;
1676 q[1] = session[s].unique_id & 0xf; // ID, dont care, we only send one type of request
1677 *(uint16_t *) (q + 2) = htons(10); // packet length
1678 q[4] = 3; // ip address option
1679 q[5] = 6; // option length
1680 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1681 config->bind_address ? config->bind_address :
1682 my_address; // send my IP
1683
1684 tunnelsend(buf, 10 + (q - buf), t); // send it
1685 }
1686
1687 void sendipv6cp(sessionidt s, tunnelidt t)
1688 {
1689 uint8_t buf[MAXETHER];
1690 uint8_t *q;
1691
1692 CSTAT(sendipv6cp);
1693 LOG(3, s, t, "IPV6CP: send ConfigReq\n");
1694
1695 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP);
1696 if (!q) return;
1697
1698 *q = ConfigReq;
1699 q[1] = session[s].unique_id & 0xf; // ID, don't care, we
1700 // only send one type
1701 // of request
1702 *(uint16_t *) (q + 2) = htons(14);
1703 q[4] = 1; // interface identifier option
1704 q[5] = 10; // option length
1705 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1706 *(uint32_t *) (q + 10) = 0;
1707 q[13] = 1;
1708
1709 tunnelsend(buf, 14 + (q - buf), t); // send it
1710 }
1711
1712 static void sessionclear(sessionidt s)
1713 {
1714 memset(&session[s], 0, sizeof(session[s]));
1715 memset(&sess_local[s], 0, sizeof(sess_local[s]));
1716 memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
1717
1718 session[s].tunnel = T_FREE; // Mark it as free.
1719 session[s].next = sessionfree;
1720 sessionfree = s;
1721 }
1722
1723 // kill a session now
1724 void sessionkill(sessionidt s, char *reason)
1725 {
1726
1727 CSTAT(sessionkill);
1728
1729 if (!session[s].opened) // not alive
1730 return;
1731
1732 if (session[s].next)
1733 {
1734 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1735 return;
1736 }
1737
1738 session[s].die = TIME;
1739 sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
1740 if (sess_local[s].radius)
1741 radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
1742
1743 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1744 sessionclear(s);
1745 cluster_send_session(s);
1746 }
1747
1748 static void tunnelclear(tunnelidt t)
1749 {
1750 if (!t) return;
1751 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1752 tunnel[t].state = TUNNELFREE;
1753 }
1754
1755 // kill a tunnel now
1756 static void tunnelkill(tunnelidt t, char *reason)
1757 {
1758 sessionidt s;
1759 controlt *c;
1760
1761 CSTAT(tunnelkill);
1762
1763 tunnel[t].state = TUNNELDIE;
1764
1765 // free control messages
1766 while ((c = tunnel[t].controls))
1767 {
1768 controlt * n = c->next;
1769 tunnel[t].controls = n;
1770 tunnel[t].controlc--;
1771 c->next = controlfree;
1772 controlfree = c;
1773 }
1774 // kill sessions
1775 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1776 if (session[s].tunnel == t)
1777 sessionkill(s, reason);
1778
1779 // free tunnel
1780 tunnelclear(t);
1781 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1782 cli_tunnel_actions[t].action = 0;
1783 cluster_send_tunnel(t);
1784 }
1785
1786 // shut down a tunnel cleanly
1787 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1788 {
1789 sessionidt s;
1790
1791 CSTAT(tunnelshutdown);
1792
1793 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1794 {
1795 // never set up, can immediately kill
1796 tunnelkill(t, reason);
1797 return;
1798 }
1799 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1800
1801 // close session
1802 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1803 if (session[s].tunnel == t)
1804 sessionshutdown(s, reason, 0, 0);
1805
1806 tunnel[t].state = TUNNELDIE;
1807 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1808 cluster_send_tunnel(t);
1809 // TBA - should we wait for sessions to stop?
1810 if (result)
1811 {
1812 controlt *c = controlnew(4); // sending StopCCN
1813 if (error)
1814 {
1815 uint8_t buf[64];
1816 int l = 4;
1817 *(uint16_t *) buf = htons(result);
1818 *(uint16_t *) (buf+2) = htons(error);
1819 if (msg)
1820 {
1821 int m = strlen(msg);
1822 if (m + 4 > sizeof(buf))
1823 m = sizeof(buf) - 4;
1824
1825 memcpy(buf+4, msg, m);
1826 l += m;
1827 }
1828
1829 controlb(c, 1, buf, l, 1);
1830 }
1831 else
1832 control16(c, 1, result, 1);
1833
1834 control16(c, 9, t, 1); // assigned tunnel (our end)
1835 controladd(c, 0, t); // send the message
1836 }
1837 }
1838
1839 // read and process packet on tunnel (UDP)
1840 void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
1841 {
1842 uint8_t *chapresponse = NULL;
1843 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1844 uint8_t *p = buf + 2;
1845
1846
1847 CSTAT(processudp);
1848
1849 udp_rx += len;
1850 udp_rx_pkt++;
1851 LOG_HEX(5, "UDP Data", buf, len);
1852 STAT(tunnel_rx_packets);
1853 INC_STAT(tunnel_rx_bytes, len);
1854 if (len < 6)
1855 {
1856 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1857 STAT(tunnel_rx_errors);
1858 return;
1859 }
1860 if ((buf[1] & 0x0F) != 2)
1861 {
1862 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1863 STAT(tunnel_rx_errors);
1864 return;
1865 }
1866 if (*buf & 0x40)
1867 { // length
1868 l = ntohs(*(uint16_t *) p);
1869 p += 2;
1870 }
1871 t = ntohs(*(uint16_t *) p);
1872 p += 2;
1873 s = ntohs(*(uint16_t *) p);
1874 p += 2;
1875 if (s >= MAXSESSION)
1876 {
1877 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1878 STAT(tunnel_rx_errors);
1879 return;
1880 }
1881 if (t >= MAXTUNNEL)
1882 {
1883 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1884 STAT(tunnel_rx_errors);
1885 return;
1886 }
1887 if (*buf & 0x08)
1888 { // ns/nr
1889 ns = ntohs(*(uint16_t *) p);
1890 p += 2;
1891 nr = ntohs(*(uint16_t *) p);
1892 p += 2;
1893 }
1894 if (*buf & 0x02)
1895 { // offset
1896 uint16_t o = ntohs(*(uint16_t *) p);
1897 p += o + 2;
1898 }
1899 if ((p - buf) > l)
1900 {
1901 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1902 STAT(tunnel_rx_errors);
1903 return;
1904 }
1905 l -= (p - buf);
1906
1907 // used to time out old tunnels
1908 if (t && tunnel[t].state == TUNNELOPEN)
1909 tunnel[t].lastrec = time_now;
1910
1911 if (*buf & 0x80)
1912 { // control
1913 uint16_t message = 0xFFFF; // message type
1914 uint8_t fatal = 0;
1915 uint8_t mandatory = 0;
1916 uint16_t asession = 0; // assigned session
1917 uint32_t amagic = 0; // magic number
1918 uint8_t aflags = 0; // flags from last LCF
1919 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1920 char called[MAXTEL] = ""; // called number
1921 char calling[MAXTEL] = ""; // calling number
1922
1923 if (!config->cluster_iam_master)
1924 {
1925 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1926 return;
1927 }
1928
1929 // control messages must have bits 0x80|0x40|0x08
1930 // (type, length and sequence) set, and bits 0x02|0x01
1931 // (offset and priority) clear
1932 if ((*buf & 0xCB) != 0xC8)
1933 {
1934 LOG(1, s, t, "Bad control header %02X\n", *buf);
1935 STAT(tunnel_rx_errors);
1936 return;
1937 }
1938
1939 // check for duplicate tunnel open message
1940 if (!t && ns == 0)
1941 {
1942 int i;
1943
1944 //
1945 // Is this a duplicate of the first packet? (SCCRQ)
1946 //
1947 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1948 {
1949 if (tunnel[i].state != TUNNELOPENING ||
1950 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1951 tunnel[i].port != ntohs(addr->sin_port) )
1952 continue;
1953 t = i;
1954 LOG(3, s, t, "Duplicate SCCRQ?\n");
1955 break;
1956 }
1957 }
1958
1959 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1960 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1961
1962 // if no tunnel specified, assign one
1963 if (!t)
1964 {
1965 if (!(t = new_tunnel()))
1966 {
1967 LOG(1, 0, 0, "No more tunnels\n");
1968 STAT(tunnel_overflow);
1969 return;
1970 }
1971 tunnelclear(t);
1972 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1973 tunnel[t].port = ntohs(addr->sin_port);
1974 tunnel[t].window = 4; // default window
1975 STAT(tunnel_created);
1976 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1977 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1978 }
1979
1980 // If the 'ns' just received is not the 'nr' we're
1981 // expecting, just send an ack and drop it.
1982 //
1983 // if 'ns' is less, then we got a retransmitted packet.
1984 // if 'ns' is greater than missed a packet. Either way
1985 // we should ignore it.
1986 if (ns != tunnel[t].nr)
1987 {
1988 // is this the sequence we were expecting?
1989 STAT(tunnel_rx_errors);
1990 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
1991 t, ns, tunnel[t].nr);
1992
1993 if (l) // Is this not a ZLB?
1994 controlnull(t);
1995 return;
1996 }
1997
1998 // check sequence of this message
1999 {
2000 int skip = tunnel[t].window; // track how many in-window packets are still in queue
2001 // some to clear maybe?
2002 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
2003 {
2004 controlt *c = tunnel[t].controls;
2005 tunnel[t].controls = c->next;
2006 tunnel[t].controlc--;
2007 c->next = controlfree;
2008 controlfree = c;
2009 skip--;
2010 tunnel[t].try = 0; // we have progress
2011 }
2012
2013 // receiver advance (do here so quoted correctly in any sends below)
2014 if (l) tunnel[t].nr = (ns + 1);
2015 if (skip < 0) skip = 0;
2016 if (skip < tunnel[t].controlc)
2017 {
2018 // some control packets can now be sent that were previous stuck out of window
2019 int tosend = tunnel[t].window - skip;
2020 controlt *c = tunnel[t].controls;
2021 while (c && skip)
2022 {
2023 c = c->next;
2024 skip--;
2025 }
2026 while (c && tosend)
2027 {
2028 tunnel[t].try = 0; // first send
2029 tunnelsend(c->buf, c->length, t);
2030 c = c->next;
2031 tosend--;
2032 }
2033 }
2034 if (!tunnel[t].controlc)
2035 tunnel[t].retry = 0; // caught up
2036 }
2037 if (l)
2038 { // if not a null message
2039 int result = 0;
2040 int error = 0;
2041 char *msg = 0;
2042
2043 // process AVPs
2044 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
2045 {
2046 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
2047 uint8_t *b = p;
2048 uint8_t flags = *p;
2049 uint16_t mtype;
2050 if (n > l)
2051 {
2052 LOG(1, s, t, "Invalid length in AVP\n");
2053 STAT(tunnel_rx_errors);
2054 return;
2055 }
2056 p += n; // next
2057 l -= n;
2058 if (flags & 0x3C) // reserved bits, should be clear
2059 {
2060 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
2061 fatal = flags;
2062 result = 2; // general error
2063 error = 3; // reserved field non-zero
2064 msg = 0;
2065 continue; // next
2066 }
2067 b += 2;
2068 if (*(uint16_t *) (b))
2069 {
2070 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
2071 fatal = flags;
2072 result = 2; // general error
2073 error = 6; // generic vendor-specific error
2074 msg = "unsupported vendor-specific";
2075 continue; // next
2076 }
2077 b += 2;
2078 mtype = ntohs(*(uint16_t *) (b));
2079 b += 2;
2080 n -= 6;
2081
2082 if (flags & 0x40)
2083 {
2084 uint16_t orig_len;
2085
2086 // handle hidden AVPs
2087 if (!*config->l2tp_secret)
2088 {
2089 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
2090 fatal = flags;
2091 result = 2; // general error
2092 error = 6; // generic vendor-specific error
2093 msg = "secret not specified";
2094 continue;
2095 }
2096 if (!session[s].random_vector_length)
2097 {
2098 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
2099 fatal = flags;
2100 result = 2; // general error
2101 error = 6; // generic
2102 msg = "no random vector";
2103 continue;
2104 }
2105 if (n < 8)
2106 {
2107 LOG(2, s, t, "Short hidden AVP.\n");
2108 fatal = flags;
2109 result = 2; // general error
2110 error = 2; // length is wrong
2111 msg = 0;
2112 continue;
2113 }
2114
2115 // Unhide the AVP
2116 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
2117
2118 orig_len = ntohs(*(uint16_t *) b);
2119 if (orig_len > n + 2)
2120 {
2121 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
2122 orig_len, n);
2123
2124 fatal = flags;
2125 result = 2; // general error
2126 error = 2; // length is wrong
2127 msg = 0;
2128 continue;
2129 }
2130
2131 b += 2;
2132 n = orig_len;
2133 }
2134
2135 LOG(4, s, t, " AVP %d (%s) len %d%s%s\n", mtype, l2tp_avp_name(mtype), n,
2136 flags & 0x40 ? ", hidden" : "", flags & 0x80 ? ", mandatory" : "");
2137
2138 switch (mtype)
2139 {
2140 case 0: // message type
2141 message = ntohs(*(uint16_t *) b);
2142 mandatory = flags & 0x80;
2143 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_code(message));
2144 break;
2145 case 1: // result code
2146 {
2147 uint16_t rescode = ntohs(*(uint16_t *) b);
2148 const char* resdesc = "(unknown)";
2149 if (message == 4)
2150 { /* StopCCN */
2151 resdesc = l2tp_stopccn_result_code(rescode);
2152 }
2153 else if (message == 14)
2154 { /* CDN */
2155 resdesc = l2tp_cdn_result_code(rescode);
2156 }
2157
2158 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2159 if (n >= 4)
2160 {
2161 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2162 LOG(4, s, t, " Error Code %d: %s\n", errcode, l2tp_error_code(errcode));
2163 }
2164 if (n > 4)
2165 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2166
2167 break;
2168 }
2169 break;
2170 case 2: // protocol version
2171 {
2172 version = ntohs(*(uint16_t *) (b));
2173 LOG(4, s, t, " Protocol version = %d\n", version);
2174 if (version && version != 0x0100)
2175 { // allow 0.0 and 1.0
2176 LOG(1, s, t, " Bad protocol version %04X\n", version);
2177 fatal = flags;
2178 result = 5; // unspported protocol version
2179 error = 0x0100; // supported version
2180 msg = 0;
2181 continue; // next
2182 }
2183 }
2184 break;
2185 case 3: // framing capabilities
2186 // LOG(4, s, t, "Framing capabilities\n");
2187 break;
2188 case 4: // bearer capabilities
2189 // LOG(4, s, t, "Bearer capabilities\n");
2190 break;
2191 case 5: // tie breaker
2192 // We never open tunnels, so we don't care about tie breakers
2193 // LOG(4, s, t, "Tie breaker\n");
2194 continue;
2195 case 6: // firmware revision
2196 // LOG(4, s, t, "Firmware revision\n");
2197 break;
2198 case 7: // host name
2199 memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
2200 memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
2201 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2202 // TBA - to send to RADIUS
2203 break;
2204 case 8: // vendor name
2205 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2206 memcpy(tunnel[t].vendor, b, (n < sizeof(tunnel[t].vendor)) ? n : sizeof(tunnel[t].vendor) - 1);
2207 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2208 break;
2209 case 9: // assigned tunnel
2210 tunnel[t].far = ntohs(*(uint16_t *) (b));
2211 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2212 break;
2213 case 10: // rx window
2214 tunnel[t].window = ntohs(*(uint16_t *) (b));
2215 if (!tunnel[t].window)
2216 tunnel[t].window = 1; // window of 0 is silly
2217 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2218 break;
2219 case 11: // Challenge
2220 {
2221 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2222 build_chap_response(b, 2, n, &chapresponse);
2223 }
2224 break;
2225 case 13: // Response
2226 // Why did they send a response? We never challenge.
2227 LOG(2, s, t, " received unexpected challenge response\n");
2228 break;
2229
2230 case 14: // assigned session
2231 asession = session[s].far = ntohs(*(uint16_t *) (b));
2232 LOG(4, s, t, " assigned session = %d\n", asession);
2233 break;
2234 case 15: // call serial number
2235 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2236 break;
2237 case 18: // bearer type
2238 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2239 // TBA - for RADIUS
2240 break;
2241 case 19: // framing type
2242 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2243 // TBA
2244 break;
2245 case 21: // called number
2246 memset(called, 0, sizeof(called));
2247 memcpy(called, b, (n < sizeof(called)) ? n : sizeof(called) - 1);
2248 LOG(4, s, t, " Called <%s>\n", called);
2249 break;
2250 case 22: // calling number
2251 memset(calling, 0, sizeof(calling));
2252 memcpy(calling, b, (n < sizeof(calling)) ? n : sizeof(calling) - 1);
2253 LOG(4, s, t, " Calling <%s>\n", calling);
2254 break;
2255 case 23: // subtype
2256 break;
2257 case 24: // tx connect speed
2258 if (n == 4)
2259 {
2260 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2261 }
2262 else
2263 {
2264 // AS5300s send connect speed as a string
2265 char tmp[30];
2266 memset(tmp, 0, sizeof(tmp));
2267 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2268 session[s].tx_connect_speed = atol(tmp);
2269 }
2270 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2271 break;
2272 case 38: // rx connect speed
2273 if (n == 4)
2274 {
2275 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2276 }
2277 else
2278 {
2279 // AS5300s send connect speed as a string
2280 char tmp[30];
2281 memset(tmp, 0, sizeof(tmp));
2282 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2283 session[s].rx_connect_speed = atol(tmp);
2284 }
2285 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2286 break;
2287 case 25: // Physical Channel ID
2288 {
2289 uint32_t tmp = ntohl(*(uint32_t *) b);
2290 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2291 break;
2292 }
2293 case 29: // Proxy Authentication Type
2294 {
2295 uint16_t atype = ntohs(*(uint16_t *)b);
2296 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, ppp_auth_type(atype));
2297 break;
2298 }
2299 case 30: // Proxy Authentication Name
2300 {
2301 char authname[64];
2302 memset(authname, 0, sizeof(authname));
2303 memcpy(authname, b, (n < sizeof(authname)) ? n : sizeof(authname) - 1);
2304 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2305 authname);
2306 break;
2307 }
2308 case 31: // Proxy Authentication Challenge
2309 {
2310 LOG(4, s, t, " Proxy Auth Challenge\n");
2311 break;
2312 }
2313 case 32: // Proxy Authentication ID
2314 {
2315 uint16_t authid = ntohs(*(uint16_t *)(b));
2316 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2317 break;
2318 }
2319 case 33: // Proxy Authentication Response
2320 LOG(4, s, t, " Proxy Auth Response\n");
2321 break;
2322 case 27: // last sent lcp
2323 { // find magic number
2324 uint8_t *p = b, *e = p + n;
2325 while (p + 1 < e && p[1] && p + p[1] <= e)
2326 {
2327 if (*p == 5 && p[1] == 6) // Magic-Number
2328 amagic = ntohl(*(uint32_t *) (p + 2));
2329 else if (*p == 7) // Protocol-Field-Compression
2330 aflags |= SESSIONPFC;
2331 else if (*p == 8) // Address-and-Control-Field-Compression
2332 aflags |= SESSIONACFC;
2333 p += p[1];
2334 }
2335 }
2336 break;
2337 case 28: // last recv lcp confreq
2338 break;
2339 case 26: // Initial Received LCP CONFREQ
2340 break;
2341 case 39: // seq required - we control it as an LNS anyway...
2342 break;
2343 case 36: // Random Vector
2344 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2345 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2346 if (n > sizeof(session[s].random_vector))
2347 n = sizeof(session[s].random_vector);
2348 memcpy(session[s].random_vector, b, n);
2349 session[s].random_vector_length = n;
2350 break;
2351 default:
2352 {
2353 static char e[] = "unknown AVP 0xXXXX";
2354 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2355 fatal = flags;
2356 result = 2; // general error
2357 error = 8; // unknown mandatory AVP
2358 sprintf((msg = e) + 14, "%04x", mtype);
2359 continue; // next
2360 }
2361 }
2362 }
2363 // process message
2364 if (fatal & 0x80)
2365 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2366 else
2367 switch (message)
2368 {
2369 case 1: // SCCRQ - Start Control Connection Request
2370 tunnel[t].state = TUNNELOPENING;
2371 if (main_quit != QUIT_SHUTDOWN)
2372 {
2373 controlt *c = controlnew(2); // sending SCCRP
2374 control16(c, 2, version, 1); // protocol version
2375 control32(c, 3, 3, 1); // framing
2376 controls(c, 7, hostname, 1); // host name
2377 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2378 control16(c, 9, t, 1); // assigned tunnel
2379 controladd(c, 0, t); // send the resply
2380 }
2381 else
2382 {
2383 tunnelshutdown(t, "Shutting down", 6, 0, 0);
2384 }
2385 break;
2386 case 2: // SCCRP
2387 tunnel[t].state = TUNNELOPEN;
2388 break;
2389 case 3: // SCCN
2390 tunnel[t].state = TUNNELOPEN;
2391 controlnull(t); // ack
2392 break;
2393 case 4: // StopCCN
2394 controlnull(t); // ack
2395 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2396 break;
2397 case 6: // HELLO
2398 controlnull(t); // simply ACK
2399 break;
2400 case 7: // OCRQ
2401 // TBA
2402 break;
2403 case 8: // OCRO
2404 // TBA
2405 break;
2406 case 9: // OCCN
2407 // TBA
2408 break;
2409 case 10: // ICRQ
2410 if (sessionfree && main_quit != QUIT_SHUTDOWN)
2411 {
2412 controlt *c = controlnew(11); // ICRP
2413
2414 s = sessionfree;
2415 sessionfree = session[s].next;
2416 memset(&session[s], 0, sizeof(session[s]));
2417
2418 if (s > config->cluster_highest_sessionid)
2419 config->cluster_highest_sessionid = s;
2420
2421 session[s].opened = time_now;
2422 session[s].tunnel = t;
2423 session[s].far = asession;
2424 session[s].last_packet = time_now;
2425 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2426 control16(c, 14, s, 1); // assigned session
2427 controladd(c, asession, t); // send the reply
2428
2429 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2430 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2431
2432 session[s].ppp.phase = Establish;
2433 session[s].ppp.lcp = Starting;
2434
2435 STAT(session_created);
2436 break;
2437 }
2438
2439 {
2440 controlt *c = controlnew(14); // CDN
2441 if (!sessionfree)
2442 {
2443 STAT(session_overflow);
2444 LOG(1, 0, t, "No free sessions\n");
2445 control16(c, 1, 4, 0); // temporary lack of resources
2446 }
2447 else
2448 control16(c, 1, 2, 7); // shutting down, try another
2449
2450 controladd(c, asession, t); // send the message
2451 }
2452 return;
2453 case 11: // ICRP
2454 // TBA
2455 break;
2456 case 12: // ICCN
2457 if (amagic == 0) amagic = time_now;
2458 session[s].magic = amagic; // set magic number
2459 session[s].l2tp_flags = aflags; // set flags received
2460 session[s].mru = PPPMTU; // default
2461 controlnull(t); // ack
2462
2463 // start LCP
2464 sess_local[s].lcp.restart = time_now + config->ppp_restart_time;
2465 sess_local[s].lcp.conf_sent = 1;
2466 sess_local[s].lcp.nak_sent = 0;
2467 sess_local[s].lcp_authtype = config->radius_authprefer;
2468 sess_local[s].ppp_mru = MRU;
2469 session[s].ppp.lcp = RequestSent;
2470 sendlcp(s, t);
2471
2472 break;
2473 case 14: // CDN
2474 controlnull(t); // ack
2475 sessionshutdown(s, "Closed (Received CDN).", 0, 0);
2476 break;
2477 case 0xFFFF:
2478 LOG(1, s, t, "Missing message type\n");
2479 break;
2480 default:
2481 STAT(tunnel_rx_errors);
2482 if (mandatory)
2483 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2484 else
2485 LOG(1, s, t, "Unknown message type %d\n", message);
2486 break;
2487 }
2488 if (chapresponse) free(chapresponse);
2489 cluster_send_tunnel(t);
2490 }
2491 else
2492 {
2493 LOG(4, s, t, " Got a ZLB ack\n");
2494 }
2495 }
2496 else
2497 { // data
2498 uint16_t proto;
2499
2500 LOG_HEX(5, "Receive Tunnel Data", p, l);
2501 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2502 { // HDLC address header, discard
2503 p += 2;
2504 l -= 2;
2505 }
2506 if (l < 2)
2507 {
2508 LOG(1, s, t, "Short ppp length %d\n", l);
2509 STAT(tunnel_rx_errors);
2510 return;
2511 }
2512 if (*p & 1)
2513 {
2514 proto = *p++;
2515 l--;
2516 }
2517 else
2518 {
2519 proto = ntohs(*(uint16_t *) p);
2520 p += 2;
2521 l -= 2;
2522 }
2523
2524 if (s && !session[s].opened) // Is something wrong??
2525 {
2526 if (!config->cluster_iam_master)
2527 {
2528 // Pass it off to the master to deal with..
2529 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2530 return;
2531 }
2532
2533
2534 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2535 STAT(tunnel_rx_errors);
2536 return;
2537 }
2538
2539 if (proto == PPPPAP)
2540 {
2541 session[s].last_packet = time_now;
2542 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2543 processpap(s, t, p, l);
2544 }
2545 else if (proto == PPPCHAP)
2546 {
2547 session[s].last_packet = time_now;
2548 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2549 processchap(s, t, p, l);
2550 }
2551 else if (proto == PPPLCP)
2552 {
2553 session[s].last_packet = time_now;
2554 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2555 processlcp(s, t, p, l);
2556 }
2557 else if (proto == PPPIPCP)
2558 {
2559 session[s].last_packet = time_now;
2560 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2561 processipcp(s, t, p, l);
2562 }
2563 else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[0])
2564 {
2565 session[s].last_packet = time_now;
2566 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2567 processipv6cp(s, t, p, l);
2568 }
2569 else if (proto == PPPCCP)
2570 {
2571 session[s].last_packet = time_now;
2572 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2573 processccp(s, t, p, l);
2574 }
2575 else if (proto == PPPIP)
2576 {
2577 if (session[s].die)
2578 {
2579 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2580 return; // closing session, PPP not processed
2581 }
2582
2583 session[s].last_packet = time_now;
2584 if (session[s].walled_garden && !config->cluster_iam_master)
2585 {
2586 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2587 return;
2588 }
2589
2590 processipin(s, t, p, l);
2591 }
2592 else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
2593 {
2594 if (session[s].die)
2595 {
2596 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2597 return; // closing session, PPP not processed
2598 }
2599
2600 session[s].last_packet = time_now;
2601 if (session[s].walled_garden && !config->cluster_iam_master)
2602 {
2603 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2604 return;
2605 }
2606
2607 processipv6in(s, t, p, l);
2608 }
2609 else if (session[s].ppp.lcp == Opened)
2610 {
2611 uint8_t buf[MAXETHER];
2612 uint8_t *q;
2613 int mru = session[s].mru;
2614 if (mru > sizeof(buf)) mru = sizeof(buf);
2615
2616 l += 6;
2617 if (l > mru) l = mru;
2618
2619 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
2620 if (!q) return;
2621
2622 *q = ProtocolRej;
2623 *(q + 1) = ++sess_local[s].lcp_ident;
2624 *(uint16_t *)(q + 2) = htons(l);
2625 *(uint16_t *)(q + 4) = htons(proto);
2626 memcpy(q + 6, p, l - 6);
2627
2628 if (proto == PPPIPV6CP)
2629 LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
2630 else
2631 LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
2632
2633 tunnelsend(buf, l + (q - buf), t);
2634 }
2635 else
2636 {
2637 LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
2638 proto, ppp_state(session[s].ppp.lcp));
2639 }
2640 }
2641 }
2642
2643 // read and process packet on tun
2644 static void processtun(uint8_t * buf, int len)
2645 {
2646 LOG_HEX(5, "Receive TUN Data", buf, len);
2647 STAT(tun_rx_packets);
2648 INC_STAT(tun_rx_bytes, len);
2649
2650 CSTAT(processtun);
2651
2652 eth_rx_pkt++;
2653 eth_rx += len;
2654 if (len < 22)
2655 {
2656 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2657 STAT(tun_rx_errors);
2658 return;
2659 }
2660
2661 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2662 processipout(buf, len);
2663 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2664 && config->ipv6_prefix.s6_addr[0])
2665 processipv6out(buf, len);
2666
2667 // Else discard.
2668 }
2669
2670 // Handle retries, timeouts. Runs every 1/10th sec, want to ensure
2671 // that we look at the whole of the tunnel, radius and session tables
2672 // every second
2673 static void regular_cleanups(double period)
2674 {
2675 // Next tunnel, radius and session to check for actions on.
2676 static tunnelidt t = 0;
2677 static int r = 0;
2678 static sessionidt s = 0;
2679
2680 int t_actions = 0;
2681 int r_actions = 0;
2682 int s_actions = 0;
2683
2684 int t_slice;
2685 int r_slice;
2686 int s_slice;
2687
2688 int i;
2689 int a;
2690
2691 // divide up tables into slices based on the last run
2692 t_slice = config->cluster_highest_tunnelid * period;
2693 r_slice = (MAXRADIUS - 1) * period;
2694 s_slice = config->cluster_highest_sessionid * period;
2695
2696 if (t_slice < 1)
2697 t_slice = 1;
2698 else if (t_slice > config->cluster_highest_tunnelid)
2699 t_slice = config->cluster_highest_tunnelid;
2700
2701 if (r_slice < 1)
2702 r_slice = 1;
2703 else if (r_slice > (MAXRADIUS - 1))
2704 r_slice = MAXRADIUS - 1;
2705
2706 if (s_slice < 1)
2707 s_slice = 1;
2708 else if (s_slice > config->cluster_highest_sessionid)
2709 s_slice = config->cluster_highest_sessionid;
2710
2711 LOG(4, 0, 0, "Begin regular cleanup (last %f seconds ago)\n", period);
2712
2713 for (i = 0; i < t_slice; i++)
2714 {
2715 t++;
2716 if (t > config->cluster_highest_tunnelid)
2717 t = 1;
2718
2719 // check for expired tunnels
2720 if (tunnel[t].die && tunnel[t].die <= TIME)
2721 {
2722 STAT(tunnel_timeout);
2723 tunnelkill(t, "Expired");
2724 t_actions++;
2725 continue;
2726 }
2727 // check for message resend
2728 if (tunnel[t].retry && tunnel[t].controlc)
2729 {
2730 // resend pending messages as timeout on reply
2731 if (tunnel[t].retry <= TIME)
2732 {
2733 controlt *c = tunnel[t].controls;
2734 uint8_t w = tunnel[t].window;
2735 tunnel[t].try++; // another try
2736 if (tunnel[t].try > 5)
2737 tunnelkill(t, "Timeout on control message"); // game over
2738 else
2739 while (c && w--)
2740 {
2741 tunnelsend(c->buf, c->length, t);
2742 c = c->next;
2743 }
2744
2745 t_actions++;
2746 }
2747 }
2748 // Send hello
2749 if (tunnel[t].state == TUNNELOPEN && !tunnel[t].controlc && (time_now - tunnel[t].lastrec) > 60)
2750 {
2751 controlt *c = controlnew(6); // sending HELLO
2752 controladd(c, 0, t); // send the message
2753 LOG(3, 0, t, "Sending HELLO message\n");
2754 t_actions++;
2755 }
2756
2757 // Check for tunnel changes requested from the CLI
2758 if ((a = cli_tunnel_actions[t].action))
2759 {
2760 cli_tunnel_actions[t].action = 0;
2761 if (a & CLI_TUN_KILL)
2762 {
2763 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2764 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2765 t_actions++;
2766 }
2767 }
2768 }
2769
2770 for (i = 0; i < r_slice; i++)
2771 {
2772 r++;
2773 if (r >= MAXRADIUS)
2774 r = 1;
2775
2776 if (!radius[r].state)
2777 continue;
2778
2779 if (radius[r].retry <= TIME)
2780 {
2781 radiusretry(r);
2782 r_actions++;
2783 }
2784 }
2785
2786 for (i = 0; i < s_slice; i++)
2787 {
2788 s++;
2789 if (s > config->cluster_highest_sessionid)
2790 s = 1;
2791
2792 if (!session[s].opened) // Session isn't in use
2793 continue;
2794
2795 // check for expired sessions
2796 if (session[s].die)
2797 {
2798 if (session[s].die <= TIME)
2799 {
2800 sessionkill(s, "Expired");
2801 s_actions++;
2802 }
2803 continue;
2804 }
2805
2806 // PPP timeouts
2807 if (sess_local[s].lcp.restart <= time_now)
2808 {
2809 int next_state = session[s].ppp.lcp;
2810 switch (session[s].ppp.lcp)
2811 {
2812 case RequestSent:
2813 case AckReceived:
2814 next_state = RequestSent;
2815
2816 case AckSent:
2817 if (sess_local[s].lcp.conf_sent < config->ppp_max_configure)
2818 {
2819 LOG(3, s, session[s].tunnel, "No ACK for LCP ConfigReq... resending\n");
2820 sess_local[s].lcp.restart = time_now + config->ppp_restart_time;
2821 sess_local[s].lcp.conf_sent++;
2822 sendlcp(s, session[s].tunnel);
2823 change_state(s, lcp, next_state);
2824 }
2825 else
2826 {
2827 sessionshutdown(s, "No response to LCP ConfigReq.", 3, 0);
2828 STAT(session_timeout);
2829 }
2830
2831 s_actions++;
2832 }
2833
2834 if (session[s].die)
2835 continue;
2836 }
2837
2838 if (sess_local[s].ipcp.restart <= time_now)
2839 {
2840 int next_state = session[s].ppp.ipcp;
2841 switch (session[s].ppp.ipcp)
2842 {
2843 case RequestSent:
2844 case AckReceived:
2845 next_state = RequestSent;
2846
2847 case AckSent:
2848 if (sess_local[s].ipcp.conf_sent < config->ppp_max_configure)
2849 {
2850 LOG(3, s, session[s].tunnel, "No ACK for IPCP ConfigReq... resending\n");
2851 sess_local[s].ipcp.restart = time_now + config->ppp_restart_time;
2852 sess_local[s].ipcp.conf_sent++;
2853 sendipcp(s, session[s].tunnel);
2854 change_state(s, ipcp, next_state);
2855 }
2856 else
2857 {
2858 sessionshutdown(s, "No response to IPCP ConfigReq.", 3, 0);
2859 STAT(session_timeout);
2860 }
2861
2862 s_actions++;
2863 }
2864
2865 if (session[s].die)
2866 continue;
2867 }
2868
2869 if (sess_local[s].ipv6cp.restart <= time_now)
2870 {
2871 int next_state = session[s].ppp.ipv6cp;
2872 switch (session[s].ppp.ipv6cp)
2873 {
2874 case RequestSent:
2875 case AckReceived:
2876 next_state = RequestSent;
2877
2878 case AckSent:
2879 if (sess_local[s].ipv6cp.conf_sent < config->ppp_max_configure)
2880 {
2881 LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq... resending\n");
2882 sess_local[s].ipv6cp.restart = time_now + config->ppp_restart_time;
2883 sess_local[s].ipv6cp.conf_sent++;
2884 sendipv6cp(s, session[s].tunnel);
2885 change_state(s, ipv6cp, next_state);
2886 }
2887 else
2888 {
2889 LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq\n");
2890 change_state(s, ipv6cp, Stopped);
2891 }
2892
2893 s_actions++;
2894 }
2895 }
2896
2897 if (sess_local[s].ccp.restart <= time_now)
2898 {
2899 int next_state = session[s].ppp.ccp;
2900 switch (session[s].ppp.ccp)
2901 {
2902 case RequestSent:
2903 case AckReceived:
2904 next_state = RequestSent;
2905
2906 case AckSent:
2907 if (sess_local[s].ccp.conf_sent < config->ppp_max_configure)
2908 {
2909 LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq... resending\n");
2910 sess_local[s].ccp.restart = time_now + config->ppp_restart_time;
2911 sess_local[s].ccp.conf_sent++;
2912 sendccp(s, session[s].tunnel);
2913 change_state(s, ccp, next_state);
2914 }
2915 else
2916 {
2917 LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq\n");
2918 change_state(s, ccp, Stopped);
2919 }
2920
2921 s_actions++;
2922 }
2923 }
2924
2925 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2926 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2927 {
2928 sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
2929 STAT(session_timeout);
2930 s_actions++;
2931 continue;
2932 }
2933
2934 // No data in ECHO_TIMEOUT seconds, send LCP ECHO
2935 if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT) &&
2936 (time_now - sess_local[s].last_echo >= ECHO_TIMEOUT))
2937 {
2938 uint8_t b[MAXETHER];
2939
2940 uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP);
2941 if (!q) continue;
2942
2943 *q = EchoReq;
2944 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2945 *(uint16_t *)(q + 2) = htons(8); // Length
2946 *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
2947
2948 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2949 (int)(time_now - session[s].last_packet));
2950 tunnelsend(b, 24, session[s].tunnel); // send it
2951 sess_local[s].last_echo = time_now;
2952 s_actions++;
2953 }
2954
2955 // Check for actions requested from the CLI
2956 if ((a = cli_session_actions[s].action))
2957 {
2958 int send = 0;
2959
2960 cli_session_actions[s].action = 0;
2961 if (a & CLI_SESS_KILL)
2962 {
2963 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2964 sessionshutdown(s, "Requested by administrator.", 3, 0);
2965 a = 0; // dead, no need to check for other actions
2966 s_actions++;
2967 }
2968
2969 if (a & CLI_SESS_NOSNOOP)
2970 {
2971 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2972 session[s].snoop_ip = 0;
2973 session[s].snoop_port = 0;
2974 s_actions++;
2975 send++;
2976 }
2977 else if (a & CLI_SESS_SNOOP)
2978 {
2979 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2980 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2981 cli_session_actions[s].snoop_port);
2982
2983 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2984 session[s].snoop_port = cli_session_actions[s].snoop_port;
2985 s_actions++;
2986 send++;
2987 }
2988
2989 if (a & CLI_SESS_NOTHROTTLE)
2990 {
2991 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2992 throttle_session(s, 0, 0);
2993 s_actions++;
2994 send++;
2995 }
2996 else if (a & CLI_SESS_THROTTLE)
2997 {
2998 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2999 cli_session_actions[s].throttle_in,
3000 cli_session_actions[s].throttle_out);
3001
3002 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
3003 s_actions++;
3004 send++;
3005 }
3006
3007 if (a & CLI_SESS_NOFILTER)
3008 {
3009 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
3010 filter_session(s, 0, 0);
3011 s_actions++;
3012 send++;
3013 }
3014 else if (a & CLI_SESS_FILTER)
3015 {
3016 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
3017 cli_session_actions[s].filter_in,
3018 cli_session_actions[s].filter_out);
3019
3020 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
3021 s_actions++;
3022 send++;
3023 }
3024
3025 if (send)
3026 cluster_send_session(s);
3027 }
3028
3029 // RADIUS interim accounting
3030 if (config->radius_accounting && config->radius_interim > 0
3031 && session[s].ip && !session[s].walled_garden
3032 && !sess_local[s].radius // RADIUS already in progress
3033 && time_now - sess_local[s].last_interim >= config->radius_interim)
3034 {
3035 int rad = radiusnew(s);
3036 if (!rad)
3037 {
3038 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
3039 STAT(radius_overflow);
3040 continue;
3041 }
3042
3043 LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
3044 session[s].user, session[s].unique_id);
3045
3046 radiussend(rad, RADIUSINTERIM);
3047 sess_local[s].last_interim = time_now;
3048 s_actions++;
3049 }
3050 }
3051
3052 LOG(4, 0, 0, "End regular cleanup: checked %d/%d/%d tunnels/radius/sessions; %d/%d/%d actions\n",
3053 t_slice, r_slice, s_slice, t_actions, r_actions, s_actions);
3054 }
3055
3056 //
3057 // Are we in the middle of a tunnel update, or radius
3058 // requests??
3059 //
3060 static int still_busy(void)
3061 {
3062 int i;
3063 static clockt last_talked = 0;
3064 static clockt start_busy_wait = 0;
3065
3066 if (!config->cluster_iam_master)
3067 {
3068 #ifdef BGP
3069 static time_t stopped_bgp = 0;
3070 if (bgp_configured)
3071 {
3072 if (!stopped_bgp)
3073 {
3074 LOG(1, 0, 0, "Shutting down in %d seconds, stopping BGP...\n", QUIT_DELAY);
3075
3076 for (i = 0; i < BGP_NUM_PEERS; i++)
3077 if (bgp_peers[i].state == Established)
3078 bgp_stop(&bgp_peers[i]);
3079
3080 stopped_bgp = time_now;
3081
3082 // we don't want to become master
3083 cluster_send_ping(0);
3084
3085 return 1;
3086 }
3087
3088 if (time_now < (stopped_bgp + QUIT_DELAY))
3089 return 1;
3090 }
3091 #endif /* BGP */
3092
3093 return 0;
3094 }
3095
3096 if (main_quit == QUIT_SHUTDOWN)
3097 {
3098 static int dropped = 0;
3099 if (!dropped)
3100 {
3101 int i;
3102
3103 LOG(1, 0, 0, "Dropping sessions and tunnels\n");
3104 for (i = 1; i < MAXTUNNEL; i++)
3105 if (tunnel[i].ip || tunnel[i].state)
3106 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3107
3108 dropped = 1;
3109 }
3110 }
3111
3112 if (start_busy_wait == 0)
3113 start_busy_wait = TIME;
3114
3115 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
3116 {
3117 if (!tunnel[i].controlc)
3118 continue;
3119
3120 if (last_talked != TIME)
3121 {
3122 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
3123 last_talked = TIME;
3124 }
3125 return 1;
3126 }
3127
3128 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
3129 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
3130 {
3131 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
3132 return 0;
3133 }
3134
3135 for (i = 1; i < MAXRADIUS; i++)
3136 {
3137 if (radius[i].state == RADIUSNULL)
3138 continue;
3139 if (radius[i].state == RADIUSWAIT)
3140 continue;
3141
3142 if (last_talked != TIME)
3143 {
3144 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
3145 last_talked = TIME;
3146 }
3147 return 1;
3148 }
3149
3150 return 0;
3151 }
3152
3153 #ifdef HAVE_EPOLL
3154 # include <sys/epoll.h>
3155 #else
3156 # define FAKE_EPOLL_IMPLEMENTATION /* include the functions */
3157 # include "fake_epoll.h"
3158 #endif
3159
3160 // the base set of fds polled: cli, cluster, tun, udp, control, dae
3161 #define BASE_FDS 6
3162
3163 // additional polled fds
3164 #ifdef BGP
3165 # define EXTRA_FDS BGP_NUM_PEERS
3166 #else
3167 # define EXTRA_FDS 0
3168 #endif
3169
3170 // main loop - gets packets on tun or udp and processes them
3171 static void mainloop(void)
3172 {
3173 int i;
3174 uint8_t buf[65536];
3175 clockt next_cluster_ping = 0; // send initial ping immediately
3176 struct epoll_event events[BASE_FDS + RADIUS_FDS + EXTRA_FDS];
3177 int maxevent = sizeof(events)/sizeof(*events);
3178
3179 if ((epollfd = epoll_create(maxevent)) < 0)
3180 {
3181 LOG(0, 0, 0, "epoll_create failed: %s\n", strerror(errno));
3182 exit(1);
3183 }
3184
3185 LOG(4, 0, 0, "Beginning of main loop. clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d\n",
3186 clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd);
3187
3188 /* setup our fds to poll for input */
3189 {
3190 static struct event_data d[BASE_FDS];
3191 struct epoll_event e;
3192
3193 e.events = EPOLLIN;
3194 i = 0;
3195
3196 d[i].type = FD_TYPE_CLI;
3197 e.data.ptr = &d[i++];
3198 epoll_ctl(epollfd, EPOLL_CTL_ADD, clifd, &e);
3199
3200 d[i].type = FD_TYPE_CLUSTER;
3201 e.data.ptr = &d[i++];
3202 epoll_ctl(epollfd, EPOLL_CTL_ADD, cluster_sockfd, &e);
3203
3204 d[i].type = FD_TYPE_TUN;
3205 e.data.ptr = &d[i++];
3206 epoll_ctl(epollfd, EPOLL_CTL_ADD, tunfd, &e);
3207
3208 d[i].type = FD_TYPE_UDP;
3209 e.data.ptr = &d[i++];
3210 epoll_ctl(epollfd, EPOLL_CTL_ADD, udpfd, &e);
3211
3212 d[i].type = FD_TYPE_CONTROL;
3213 e.data.ptr = &d[i++];
3214 epoll_ctl(epollfd, EPOLL_CTL_ADD, controlfd, &e);
3215
3216 d[i].type = FD_TYPE_DAE;
3217 e.data.ptr = &d[i++];
3218 epoll_ctl(epollfd, EPOLL_CTL_ADD, daefd, &e);
3219 }
3220
3221 #ifdef BGP
3222 signal(SIGPIPE, SIG_IGN);
3223 bgp_setup(config->as_number);
3224 if (config->bind_address)
3225 bgp_add_route(config->bind_address, 0xffffffff);
3226
3227 for (i = 0; i < BGP_NUM_PEERS; i++)
3228 {
3229 if (config->neighbour[i].name[0])
3230 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3231 config->neighbour[i].as, config->neighbour[i].keepalive,
3232 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3233 }
3234 #endif /* BGP */
3235
3236 while (!main_quit || still_busy())
3237 {
3238 int more = 0;
3239 int n;
3240
3241
3242 if (main_reload)
3243 {
3244 main_reload = 0;
3245 read_config_file();
3246 config->reload_config++;
3247 }
3248
3249 if (config->reload_config)
3250 {
3251 config->reload_config = 0;
3252 update_config();
3253 }
3254
3255 #ifdef BGP
3256 bgp_set_poll();
3257 #endif /* BGP */
3258
3259 n = epoll_wait(epollfd, events, maxevent, 100); // timeout 100ms (1/10th sec)
3260 STAT(select_called);
3261
3262 TIME = now(NULL);
3263 if (n < 0)
3264 {
3265 if (errno == EINTR ||
3266 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
3267 continue;
3268
3269 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
3270 break; // exit
3271 }
3272
3273 if (n)
3274 {
3275 struct sockaddr_in addr;
3276 socklen_t alen;
3277 int c, s;
3278 int udp_ready = 0;
3279 int tun_ready = 0;
3280 int cluster_ready = 0;
3281 int udp_pkts = 0;
3282 int tun_pkts = 0;
3283 int cluster_pkts = 0;
3284 #ifdef BGP
3285 uint32_t bgp_events[BGP_NUM_PEERS];
3286 memset(bgp_events, 0, sizeof(bgp_events));
3287 #endif /* BGP */
3288
3289 for (c = n, i = 0; i < c; i++)
3290 {
3291 struct event_data *d = events[i].data.ptr;
3292 switch (d->type)
3293 {
3294 case FD_TYPE_CLI: // CLI connections
3295 {
3296 int cli;
3297
3298 alen = sizeof(addr);
3299 if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
3300 {
3301 cli_do(cli);
3302 close(cli);
3303 }
3304 else
3305 LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
3306
3307 n--;
3308 break;
3309 }
3310
3311 // these are handled below, with multiple interleaved reads
3312 case FD_TYPE_CLUSTER: cluster_ready++; break;
3313 case FD_TYPE_TUN: tun_ready++; break;
3314 case FD_TYPE_UDP: udp_ready++; break;
3315
3316 case FD_TYPE_CONTROL: // nsctl commands
3317 alen = sizeof(addr);
3318 processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
3319 n--;
3320 break;
3321
3322 case FD_TYPE_DAE: // DAE requests
3323 alen = sizeof(addr);
3324 processdae(buf, recvfrom(daefd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
3325 n--;
3326 break;
3327
3328 case FD_TYPE_RADIUS: // RADIUS response
3329 s = recv(radfds[d->index], buf, sizeof(buf), 0);
3330 if (s >= 0 && config->cluster_iam_master)
3331 processrad(buf, s, d->index);
3332
3333 n--;
3334 break;
3335
3336 #ifdef BGP
3337 case FD_TYPE_BGP:
3338 bgp_events[d->index] = events[i].events;
3339 n--;
3340 break;
3341 #endif /* BGP */
3342
3343 default:
3344 LOG(0, 0, 0, "Unexpected fd type returned from epoll_wait: %d\n", d->type);
3345 }
3346 }
3347
3348 #ifdef BGP
3349 bgp_process(bgp_events);
3350 #endif /* BGP */
3351
3352 for (c = 0; n && c < config->multi_read_count; c++)
3353 {
3354 // L2TP
3355 if (udp_ready)
3356 {
3357 alen = sizeof(addr);
3358 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
3359 {
3360 processudp(buf, s, &addr);
3361 udp_pkts++;
3362 }
3363 else
3364 {
3365 udp_ready = 0;
3366 n--;
3367 }
3368 }
3369
3370 // incoming IP
3371 if (tun_ready)
3372 {
3373 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
3374 {
3375 processtun(buf, s);
3376 tun_pkts++;
3377 }
3378 else
3379 {
3380 tun_ready = 0;
3381 n--;
3382 }
3383 }
3384
3385 // cluster
3386 if (cluster_ready)
3387 {
3388 alen = sizeof(addr);
3389 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
3390 {
3391 processcluster(buf, s, addr.sin_addr.s_addr);
3392 cluster_pkts++;
3393 }
3394 else
3395 {
3396 cluster_ready = 0;
3397 n--;
3398 }
3399 }
3400 }
3401
3402 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
3403 STAT(multi_read_used);
3404
3405 if (c >= config->multi_read_count)
3406 {
3407 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
3408 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3409
3410 STAT(multi_read_exceeded);
3411 more++;
3412 }
3413 }
3414
3415 if (time_changed)
3416 {
3417 double Mbps = 1024.0 * 1024.0 / 8 * time_changed;
3418
3419 // Log current traffic stats
3420 snprintf(config->bandwidth, sizeof(config->bandwidth),
3421 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3422 (udp_rx / Mbps), (eth_tx / Mbps), (eth_rx / Mbps), (udp_tx / Mbps),
3423 ((udp_tx + udp_rx + eth_tx + eth_rx) / Mbps),
3424 udp_rx_pkt / time_changed, eth_rx_pkt / time_changed);
3425
3426 udp_tx = udp_rx = 0;
3427 udp_rx_pkt = eth_rx_pkt = 0;
3428 eth_tx = eth_rx = 0;
3429 time_changed = 0;
3430
3431 if (config->dump_speed)
3432 printf("%s\n", config->bandwidth);
3433
3434 // Update the internal time counter
3435 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3436
3437 {
3438 // Run timer hooks
3439 struct param_timer p = { time_now };
3440 run_plugins(PLUGIN_TIMER, &p);
3441 }
3442 }
3443
3444 // Runs on every machine (master and slaves).
3445 if (next_cluster_ping <= TIME)
3446 {
3447 // Check to see which of the cluster is still alive..
3448
3449 cluster_send_ping(basetime); // Only does anything if we're a slave
3450 cluster_check_master(); // ditto.
3451
3452 cluster_heartbeat(); // Only does anything if we're a master.
3453 cluster_check_slaves(); // ditto.
3454
3455 master_update_counts(); // If we're a slave, send our byte counters to our master.
3456
3457 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3458 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3459 else
3460 next_cluster_ping = TIME + config->cluster_hb_interval;
3461 }
3462
3463 if (!config->cluster_iam_master)
3464 continue;
3465
3466 // Run token bucket filtering queue..
3467 // Only run it every 1/10th of a second.
3468 {
3469 static clockt last_run = 0;
3470 if (last_run != TIME)
3471 {
3472 last_run = TIME;
3473 tbf_run_timer();
3474 }
3475 }
3476
3477 // Handle timeouts, retries etc.
3478 {
3479 static double last_clean = 0;
3480 double this_clean;
3481 double diff;
3482
3483 TIME = now(&this_clean);
3484 diff = this_clean - last_clean;
3485
3486 // Run during idle time (after we've handled
3487 // all incoming packets) or every 1/10th sec
3488 if (!more || diff > 0.1)
3489 {
3490 regular_cleanups(diff);
3491 last_clean = this_clean;
3492 }
3493 }
3494
3495 if (*config->accounting_dir)
3496 {
3497 static clockt next_acct = 0;
3498 static clockt next_shut_acct = 0;
3499
3500 if (next_acct <= TIME)
3501 {
3502 // Dump accounting data
3503 next_acct = TIME + ACCT_TIME;
3504 next_shut_acct = TIME + ACCT_SHUT_TIME;
3505 dump_acct_info(1);
3506 }
3507 else if (next_shut_acct <= TIME)
3508 {
3509 // Dump accounting data for shutdown sessions
3510 next_shut_acct = TIME + ACCT_SHUT_TIME;
3511 if (shut_acct_n)
3512 dump_acct_info(0);
3513 }
3514 }
3515 }
3516
3517 // Are we the master and shutting down??
3518 if (config->cluster_iam_master)
3519 cluster_heartbeat(); // Flush any queued changes..
3520
3521 // Ok. Notify everyone we're shutting down. If we're
3522 // the master, this will force an election.
3523 cluster_send_ping(0);
3524
3525 //
3526 // Important!!! We MUST not process any packets past this point!
3527 LOG(1, 0, 0, "Shutdown complete\n");
3528 }
3529
3530 static void stripdomain(char *host)
3531 {
3532 char *p;
3533
3534 if ((p = strchr(host, '.')))
3535 {
3536 char *domain = 0;
3537 char _domain[1024];
3538
3539 // strip off domain
3540 FILE *resolv = fopen("/etc/resolv.conf", "r");
3541 if (resolv)
3542 {
3543 char buf[1024];
3544 char *b;
3545
3546 while (fgets(buf, sizeof(buf), resolv))
3547 {
3548 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3549 continue;
3550
3551 if (!isspace(buf[6]))
3552 continue;
3553
3554 b = buf + 7;
3555 while (isspace(*b)) b++;
3556
3557 if (*b)
3558 {
3559 char *d = b;
3560 while (*b && !isspace(*b)) b++;
3561 *b = 0;
3562 if (buf[0] == 'd') // domain is canonical
3563 {
3564 domain = d;
3565 break;
3566 }
3567
3568 // first search line
3569 if (!domain)
3570 {
3571 // hold, may be subsequent domain line
3572 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3573 domain = _domain;
3574 }
3575 }
3576 }
3577
3578 fclose(resolv);
3579 }
3580
3581 if (domain)
3582 {
3583 int hl = strlen(host);
3584 int dl = strlen(domain);
3585 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3586 host[hl -dl - 1] = 0;
3587 }
3588 else
3589 {
3590 *p = 0; // everything after first dot
3591 }
3592 }
3593 }
3594
3595 // Init data structures
3596 static void initdata(int optdebug, char *optconfig)
3597 {
3598 int i;
3599
3600 if (!(config = shared_malloc(sizeof(configt))))
3601 {
3602 fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
3603 exit(1);
3604 }
3605
3606 memset(config, 0, sizeof(configt));
3607 time(&config->start_time);
3608 strncpy(config->config_file, optconfig, strlen(optconfig));
3609 config->debug = optdebug;
3610 config->num_tbfs = MAXTBFS;
3611 config->rl_rate = 28; // 28kbps
3612 config->cluster_mcast_ttl = 1;
3613 config->cluster_master_min_adv = 1;
3614 config->ppp_restart_time = 3;
3615 config->ppp_max_configure = 10;
3616 config->ppp_max_failure = 5;
3617 strcpy(config->random_device, RANDOMDEVICE);
3618
3619 log_stream = stderr;
3620
3621 #ifdef RINGBUFFER
3622 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3623 {
3624 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3625 exit(1);
3626 }
3627 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3628 #endif
3629
3630 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3631 {
3632 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3633 exit(1);
3634 }
3635 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3636 {
3637 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3638 exit(1);
3639 }
3640 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3641 {
3642 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3643 exit(1);
3644 }
3645
3646 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3647 {
3648 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3649 exit(1);
3650 }
3651
3652 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3653 {
3654 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3655 exit(1);
3656 }
3657
3658 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3659 {
3660 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3661 exit(1);
3662 }
3663
3664 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3665 {
3666 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3667 exit(1);
3668 }
3669 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3670
3671 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3672 {
3673 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3674 exit(1);
3675 }
3676 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3677
3678 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3679 {
3680 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3681 exit(1);
3682 }
3683 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3684
3685 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3686 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3687 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3688 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3689
3690 // Put all the sessions on the free list marked as undefined.
3691 for (i = 1; i < MAXSESSION; i++)
3692 {
3693 session[i].next = i + 1;
3694 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3695 }
3696 session[MAXSESSION - 1].next = 0;
3697 sessionfree = 1;
3698
3699 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3700 for (i = 1; i < MAXTUNNEL; i++)
3701 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3702
3703 if (!*hostname)
3704 {
3705 // Grab my hostname unless it's been specified
3706 gethostname(hostname, sizeof(hostname));
3707 stripdomain(hostname);
3708 }
3709
3710 _statistics->start_time = _statistics->last_reset = time(NULL);
3711
3712 #ifdef BGP
3713 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3714 {
3715 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3716 exit(1);
3717 }
3718 #endif /* BGP */
3719 }
3720
3721 static int assign_ip_address(sessionidt s)
3722 {
3723 uint32_t i;
3724 int best = -1;
3725 time_t best_time = time_now;
3726 char *u = session[s].user;
3727 char reuse = 0;
3728
3729
3730 CSTAT(assign_ip_address);
3731
3732 for (i = 1; i < ip_pool_size; i++)
3733 {
3734 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3735 continue;
3736
3737 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3738 {
3739 best = i;
3740 reuse = 1;
3741 break;
3742 }
3743
3744 if (ip_address_pool[i].last < best_time)
3745 {
3746 best = i;
3747 if (!(best_time = ip_address_pool[i].last))
3748 break; // never used, grab this one
3749 }
3750 }
3751
3752 if (best < 0)
3753 {
3754 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3755 return 0;
3756 }
3757
3758 session[s].ip = ip_address_pool[best].address;
3759 session[s].ip_pool_index = best;
3760 ip_address_pool[best].assigned = 1;
3761 ip_address_pool[best].last = time_now;
3762 ip_address_pool[best].session = s;
3763 if (session[s].walled_garden)
3764 /* Don't track addresses of users in walled garden (note: this
3765 means that their address isn't "sticky" even if they get
3766 un-gardened). */
3767 ip_address_pool[best].user[0] = 0;
3768 else
3769 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3770
3771 STAT(ip_allocated);
3772 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3773 reuse ? "Reusing" : "Allocating", best);
3774
3775 return 1;
3776 }
3777
3778 static void free_ip_address(sessionidt s)
3779 {
3780 int i = session[s].ip_pool_index;
3781
3782
3783 CSTAT(free_ip_address);
3784
3785 if (!session[s].ip)
3786 return; // what the?
3787
3788 if (i < 0) // Is this actually part of the ip pool?
3789 i = 0;
3790
3791 STAT(ip_freed);
3792 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3793 session[s].ip = 0;
3794 ip_address_pool[i].assigned = 0;
3795 ip_address_pool[i].session = 0;
3796 ip_address_pool[i].last = time_now;
3797 }
3798
3799 //
3800 // Fsck the address pool against the session table.
3801 // Normally only called when we become a master.
3802 //
3803 // This isn't perfect: We aren't keep tracking of which
3804 // users used to have an IP address.
3805 //
3806 void rebuild_address_pool(void)
3807 {
3808 int i;
3809
3810 //
3811 // Zero the IP pool allocation, and build
3812 // a map from IP address to pool index.
3813 for (i = 1; i < MAXIPPOOL; ++i)
3814 {
3815 ip_address_pool[i].assigned = 0;
3816 ip_address_pool[i].session = 0;
3817 if (!ip_address_pool[i].address)
3818 continue;
3819
3820 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3821 }
3822
3823 for (i = 0; i < MAXSESSION; ++i)
3824 {
3825 int ipid;
3826 if (!(session[i].opened && session[i].ip))
3827 continue;
3828
3829 ipid = - lookup_ipmap(htonl(session[i].ip));
3830
3831 if (session[i].ip_pool_index < 0)
3832 {
3833 // Not allocated out of the pool.
3834 if (ipid < 1) // Not found in the pool either? good.
3835 continue;
3836
3837 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3838 i, fmtaddr(session[i].ip, 0), ipid);
3839
3840 // Fall through and process it as part of the pool.
3841 }
3842
3843
3844 if (ipid > MAXIPPOOL || ipid < 0)
3845 {
3846 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3847 ipid = -1;
3848 session[i].ip_pool_index = ipid;
3849 continue;
3850 }
3851
3852 ip_address_pool[ipid].assigned = 1;
3853 ip_address_pool[ipid].session = i;
3854 ip_address_pool[ipid].last = time_now;
3855 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3856 session[i].ip_pool_index = ipid;
3857 cache_ipmap(session[i].ip, i); // Fix the ip map.
3858 }
3859 }
3860
3861 //
3862 // Fix the address pool to match a changed session.
3863 // (usually when the master sends us an update).
3864 static void fix_address_pool(int sid)
3865 {
3866 int ipid;
3867
3868 ipid = session[sid].ip_pool_index;
3869
3870 if (ipid > ip_pool_size)
3871 return; // Ignore it. rebuild_address_pool will fix it up.
3872
3873 if (ip_address_pool[ipid].address != session[sid].ip)
3874 return; // Just ignore it. rebuild_address_pool will take care of it.
3875
3876 ip_address_pool[ipid].assigned = 1;
3877 ip_address_pool[ipid].session = sid;
3878 ip_address_pool[ipid].last = time_now;
3879 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3880 }
3881
3882 //
3883 // Add a block of addresses to the IP pool to hand out.
3884 //
3885 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3886 {
3887 int i;
3888 if (mask == 0)
3889 mask = 0xffffffff; // Host route only.
3890
3891 addr &= mask;
3892
3893 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3894 return ;
3895
3896 for (i = addr ;(i & mask) == addr; ++i)
3897 {
3898 if ((i & 0xff) == 0 || (i&0xff) == 255)
3899 continue; // Skip 0 and broadcast addresses.
3900
3901 ip_address_pool[ip_pool_size].address = i;
3902 ip_address_pool[ip_pool_size].assigned = 0;
3903 ++ip_pool_size;
3904 if (ip_pool_size >= MAXIPPOOL)
3905 {
3906 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3907 return;
3908 }
3909 }
3910 }
3911
3912 // Initialize the IP address pool
3913 static void initippool()
3914 {
3915 FILE *f;
3916 char *p;
3917 char buf[4096];
3918 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3919
3920 if (!(f = fopen(IPPOOLFILE, "r")))
3921 {
3922 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3923 exit(1);
3924 }
3925
3926 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3927 {
3928 char *pool = buf;
3929 buf[4095] = 0; // Force it to be zero terminated/
3930
3931 if (*buf == '#' || *buf == '\n')
3932 continue; // Skip comments / blank lines
3933 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3934 if ((p = (char *)strchr(buf, ':')))
3935 {
3936 in_addr_t src;
3937 *p = '\0';
3938 src = inet_addr(buf);
3939 if (src == INADDR_NONE)
3940 {
3941 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3942 exit(1);
3943 }
3944 // This entry is for a specific IP only
3945 if (src != config->bind_address)
3946 continue;
3947 *p = ':';
3948 pool = p+1;
3949 }
3950 if ((p = (char *)strchr(pool, '/')))
3951 {
3952 // It's a range
3953 int numbits = 0;
3954 in_addr_t start = 0, mask = 0;
3955
3956 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3957 *p++ = 0;
3958 if (!*p || !(numbits = atoi(p)))
3959 {
3960 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3961 continue;
3962 }
3963 start = ntohl(inet_addr(pool));
3964 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3965
3966 // Add a static route for this pool
3967 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3968 fmtaddr(htonl(start), 0), 32 + mask);
3969
3970 routeset(0, start, mask, 0, 1);
3971
3972 add_to_ip_pool(start, mask);
3973 }
3974 else
3975 {
3976 // It's a single ip address
3977 add_to_ip_pool(inet_addr(pool), 0);
3978 }
3979 }
3980 fclose(f);
3981 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3982 }
3983
3984 void snoop_send_packet(uint8_t *packet, uint16_t size, in_addr_t destination, uint16_t port)
3985 {
3986 struct sockaddr_in snoop_addr = {0};
3987 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3988 return;
3989
3990 snoop_addr.sin_family = AF_INET;
3991 snoop_addr.sin_addr.s_addr = destination;
3992 snoop_addr.sin_port = ntohs(port);
3993
3994 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3995 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3996 htons(snoop_addr.sin_port));
3997
3998 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3999 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
4000
4001 STAT(packets_snooped);
4002 }
4003
4004 static int dump_session(FILE **f, sessiont *s)
4005 {
4006 if (!s->opened || !s->ip || !(s->cin_delta || s->cout_delta) || !*s->user || s->walled_garden)
4007 return 1;
4008
4009 if (!*f)
4010 {
4011 char filename[1024];
4012 char timestr[64];
4013 time_t now = time(NULL);
4014
4015 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
4016 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
4017
4018 if (!(*f = fopen(filename, "w")))
4019 {
4020 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
4021 return 0;
4022 }
4023
4024 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
4025 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
4026 "# host: %s\n"
4027 "# endpoint: %s\n"
4028 "# time: %ld\n"
4029 "# uptime: %ld\n"
4030 "# format: username ip qos uptxoctets downrxoctets\n",
4031 hostname,
4032 fmtaddr(config->bind_address ? config->bind_address : my_address, 0),
4033 now,
4034 now - basetime);
4035 }
4036
4037 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
4038 fprintf(*f, "%s %s %d %u %u\n",
4039 s->user, // username
4040 fmtaddr(htonl(s->ip), 0), // ip
4041 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
4042 (uint32_t) s->cin_delta, // uptxoctets
4043 (uint32_t) s->cout_delta); // downrxoctets
4044
4045 s->cin_delta = s->cout_delta = 0;
4046
4047 return 1;
4048 }
4049
4050 static void dump_acct_info(int all)
4051 {
4052 int i;
4053 FILE *f = NULL;
4054
4055
4056 CSTAT(dump_acct_info);
4057
4058 if (shut_acct_n)
4059 {
4060 for (i = 0; i < shut_acct_n; i++)
4061 dump_session(&f, &shut_acct[i]);
4062
4063 shut_acct_n = 0;
4064 }
4065
4066 if (all)
4067 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4068 dump_session(&f, &session[i]);
4069
4070 if (f)
4071 fclose(f);
4072 }
4073
4074 // Main program
4075 int main(int argc, char *argv[])
4076 {
4077 int i;
4078 int optdebug = 0;
4079 char *optconfig = CONFIGFILE;
4080
4081 time(&basetime); // start clock
4082
4083 // scan args
4084 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
4085 {
4086 switch (i)
4087 {
4088 case 'd':
4089 if (fork()) exit(0);
4090 setsid();
4091 freopen("/dev/null", "r", stdin);
4092 freopen("/dev/null", "w", stdout);
4093 freopen("/dev/null", "w", stderr);
4094 break;
4095 case 'v':
4096 optdebug++;
4097 break;
4098 case 'c':
4099 optconfig = optarg;
4100 break;
4101 case 'h':
4102 snprintf(hostname, sizeof(hostname), "%s", optarg);
4103 break;
4104 default:
4105 printf("Args are:\n"
4106 "\t-d\t\tDetach from terminal\n"
4107 "\t-c <file>\tConfig file\n"
4108 "\t-h <hostname>\tForce hostname\n"
4109 "\t-v\t\tDebug\n");
4110
4111 return (0);
4112 break;
4113 }
4114 }
4115
4116 // Start the timer routine off
4117 time(&time_now);
4118 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
4119
4120 initplugins();
4121 initdata(optdebug, optconfig);
4122
4123 init_cli(hostname);
4124 read_config_file();
4125 update_config();
4126 init_tbf(config->num_tbfs);
4127
4128 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
4129 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
4130 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
4131 {
4132 struct rlimit rlim;
4133 rlim.rlim_cur = RLIM_INFINITY;
4134 rlim.rlim_max = RLIM_INFINITY;
4135 // Remove the maximum core size
4136 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
4137 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
4138
4139 // Make core dumps go to /tmp
4140 chdir("/tmp");
4141 }
4142
4143 if (config->scheduler_fifo)
4144 {
4145 int ret;
4146 struct sched_param params = {0};
4147 params.sched_priority = 1;
4148
4149 if (get_nprocs() < 2)
4150 {
4151 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
4152 config->scheduler_fifo = 0;
4153 }
4154 else
4155 {
4156 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
4157 {
4158 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
4159 }
4160 else
4161 {
4162 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
4163 config->scheduler_fifo = 0;
4164 }
4165 }
4166 }
4167
4168 /* Set up the cluster communications port. */
4169 if (cluster_init() < 0)
4170 exit(1);
4171
4172 inittun();
4173 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
4174
4175 initudp();
4176 initrad();
4177 initippool();
4178
4179 // seed prng
4180 {
4181 unsigned seed = time_now ^ getpid();
4182 LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
4183 srand(seed);
4184 }
4185
4186 signal(SIGHUP, sighup_handler);
4187 signal(SIGCHLD, sigchild_handler);
4188 signal(SIGTERM, shutdown_handler);
4189 signal(SIGINT, shutdown_handler);
4190 signal(SIGQUIT, shutdown_handler);
4191
4192 // Prevent us from getting paged out
4193 if (config->lock_pages)
4194 {
4195 if (!mlockall(MCL_CURRENT))
4196 LOG(1, 0, 0, "Locking pages into memory\n");
4197 else
4198 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
4199 }
4200
4201 // Drop privileges here
4202 if (config->target_uid > 0 && geteuid() == 0)
4203 setuid(config->target_uid);
4204
4205 mainloop();
4206
4207 /* remove plugins (so cleanup code gets run) */
4208 plugins_done();
4209
4210 // Remove the PID file if we wrote it
4211 if (config->wrote_pid && *config->pid_file == '/')
4212 unlink(config->pid_file);
4213
4214 /* kill CLI children */
4215 signal(SIGTERM, SIG_IGN);
4216 kill(0, SIGTERM);
4217 return 0;
4218 }
4219
4220 static void sighup_handler(int sig)
4221 {
4222 main_reload++;
4223 }
4224
4225 static void shutdown_handler(int sig)
4226 {
4227 main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
4228 }
4229
4230 static void sigchild_handler(int sig)
4231 {
4232 while (waitpid(-1, NULL, WNOHANG) > 0)
4233 ;
4234 }
4235
4236 static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response)
4237 {
4238 MD5_CTX ctx;
4239 *challenge_response = NULL;
4240
4241 if (!*config->l2tp_secret)
4242 {
4243 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
4244 return;
4245 }
4246
4247 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
4248
4249 *challenge_response = calloc(17, 1);
4250
4251 MD5_Init(&ctx);
4252 MD5_Update(&ctx, &id, 1);
4253 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
4254 MD5_Update(&ctx, challenge, challenge_length);
4255 MD5_Final(*challenge_response, &ctx);
4256
4257 return;
4258 }
4259
4260 static int facility_value(char *name)
4261 {
4262 int i;
4263 for (i = 0; facilitynames[i].c_name; i++)
4264 {
4265 if (strcmp(facilitynames[i].c_name, name) == 0)
4266 return facilitynames[i].c_val;
4267 }
4268 return 0;
4269 }
4270
4271 static void update_config()
4272 {
4273 int i;
4274 char *p;
4275 static int timeout = 0;
4276 static int interval = 0;
4277
4278 // Update logging
4279 closelog();
4280 syslog_log = 0;
4281 if (log_stream)
4282 {
4283 if (log_stream != stderr)
4284 fclose(log_stream);
4285
4286 log_stream = NULL;
4287 }
4288
4289 if (*config->log_filename)
4290 {
4291 if (strstr(config->log_filename, "syslog:") == config->log_filename)
4292 {
4293 char *p = config->log_filename + 7;
4294 if (*p)
4295 {
4296 openlog("l2tpns", LOG_PID, facility_value(p));
4297 syslog_log = 1;
4298 }
4299 }
4300 else if (strchr(config->log_filename, '/') == config->log_filename)
4301 {
4302 if ((log_stream = fopen((char *)(config->log_filename), "a")))
4303 {
4304 fseek(log_stream, 0, SEEK_END);
4305 setbuf(log_stream, NULL);
4306 }
4307 else
4308 {
4309 log_stream = stderr;
4310 setbuf(log_stream, NULL);
4311 }
4312 }
4313 }
4314 else
4315 {
4316 log_stream = stderr;
4317 setbuf(log_stream, NULL);
4318 }
4319
4320 #define L2TP_HDRS (20+8+6+4) // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
4321 #define TCP_HDRS (20+20) // TCP encapsulation: ip + tcp
4322
4323 if (config->l2tp_mtu <= 0) config->l2tp_mtu = PPPMTU;
4324 else if (config->l2tp_mtu < MINMTU) config->l2tp_mtu = MINMTU;
4325 else if (config->l2tp_mtu > MAXMTU) config->l2tp_mtu = MAXMTU;
4326
4327 // reset MRU/MSS globals
4328 MRU = config->l2tp_mtu - L2TP_HDRS;
4329 MSS = MRU - TCP_HDRS;
4330
4331 // Update radius
4332 config->numradiusservers = 0;
4333 for (i = 0; i < MAXRADSERVER; i++)
4334 if (config->radiusserver[i])
4335 {
4336 config->numradiusservers++;
4337 // Set radius port: if not set, take the port from the
4338 // first radius server. For the first radius server,
4339 // take the #defined default value from l2tpns.h
4340
4341 // test twice, In case someone works with
4342 // a secondary radius server without defining
4343 // a primary one, this will work even then.
4344 if (i > 0 && !config->radiusport[i])
4345 config->radiusport[i] = config->radiusport[i-1];
4346 if (!config->radiusport[i])
4347 config->radiusport[i] = RADPORT;
4348 }
4349
4350 if (!config->numradiusservers)
4351 LOG(0, 0, 0, "No RADIUS servers defined!\n");
4352
4353 // parse radius_authtypes_s
4354 config->radius_authtypes = config->radius_authprefer = 0;
4355 p = config->radius_authtypes_s;
4356 while (p && *p)
4357 {
4358 char *s = strpbrk(p, " \t,");
4359 int type = 0;
4360
4361 if (s)
4362 {
4363 *s++ = 0;
4364 while (*s == ' ' || *s == '\t')
4365 s++;
4366
4367 if (!*s)
4368 s = 0;
4369 }
4370
4371 if (!strncasecmp("chap", p, strlen(p)))
4372 type = AUTHCHAP;
4373 else if (!strncasecmp("pap", p, strlen(p)))
4374 type = AUTHPAP;
4375 else
4376 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
4377
4378 config->radius_authtypes |= type;
4379 if (!config->radius_authprefer)
4380 config->radius_authprefer = type;
4381
4382 p = s;
4383 }
4384
4385 if (!config->radius_authtypes)
4386 {
4387 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
4388 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
4389 }
4390
4391 // normalise radius_authtypes_s
4392 if (config->radius_authprefer == AUTHPAP)
4393 {
4394 strcpy(config->radius_authtypes_s, "pap");
4395 if (config->radius_authtypes & AUTHCHAP)
4396 strcat(config->radius_authtypes_s, ", chap");
4397 }
4398 else
4399 {
4400 strcpy(config->radius_authtypes_s, "chap");
4401 if (config->radius_authtypes & AUTHPAP)
4402 strcat(config->radius_authtypes_s, ", pap");
4403 }
4404
4405 if (!config->radius_dae_port)
4406 config->radius_dae_port = DAEPORT;
4407
4408 // re-initialise the random number source
4409 initrandom(config->random_device);
4410
4411 // Update plugins
4412 for (i = 0; i < MAXPLUGINS; i++)
4413 {
4414 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4415 continue;
4416
4417 if (*config->plugins[i])
4418 {
4419 // Plugin added
4420 add_plugin(config->plugins[i]);
4421 }
4422 else if (*config->old_plugins[i])
4423 {
4424 // Plugin removed
4425 remove_plugin(config->old_plugins[i]);
4426 }
4427 }
4428
4429 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4430 if (!config->multi_read_count) config->multi_read_count = 10;
4431 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4432 if (!*config->cluster_interface)
4433 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4434
4435 if (!config->cluster_hb_interval)
4436 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4437
4438 if (!config->cluster_hb_timeout)
4439 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4440
4441 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4442 {
4443 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4444 // late, ensure we're sufficiently larger than that
4445 int t = 4 * config->cluster_hb_interval + 11;
4446
4447 if (config->cluster_hb_timeout < t)
4448 {
4449 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4450 config->cluster_hb_timeout = t;
4451 }
4452
4453 // Push timing changes to the slaves immediately if we're the master
4454 if (config->cluster_iam_master)
4455 cluster_heartbeat();
4456
4457 interval = config->cluster_hb_interval;
4458 timeout = config->cluster_hb_timeout;
4459 }
4460
4461 // Write PID file
4462 if (*config->pid_file == '/' && !config->wrote_pid)
4463 {
4464 FILE *f;
4465 if ((f = fopen(config->pid_file, "w")))
4466 {
4467 fprintf(f, "%d\n", getpid());
4468 fclose(f);
4469 config->wrote_pid = 1;
4470 }
4471 else
4472 {
4473 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4474 }
4475 }
4476 }
4477
4478 static void read_config_file()
4479 {
4480 FILE *f;
4481
4482 if (!config->config_file) return;
4483 if (!(f = fopen(config->config_file, "r")))
4484 {
4485 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4486 return;
4487 }
4488
4489 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4490 cli_do_file(f);
4491 LOG(3, 0, 0, "Done reading config file\n");
4492 fclose(f);
4493 }
4494
4495 int sessionsetup(sessionidt s, tunnelidt t)
4496 {
4497 // A session now exists, set it up
4498 in_addr_t ip;
4499 char *user;
4500 sessionidt i;
4501 int r;
4502
4503 CSTAT(sessionsetup);
4504
4505 LOG(3, s, t, "Doing session setup for session\n");
4506
4507 if (!session[s].ip)
4508 {
4509 assign_ip_address(s);
4510 if (!session[s].ip)
4511 {
4512 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4513 sessionshutdown(s, "No IP addresses available.", 2, 7); // try another
4514 return 0;
4515 }
4516 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4517 fmtaddr(htonl(session[s].ip), 0));
4518 }
4519
4520
4521 // Make sure this is right
4522 session[s].tunnel = t;
4523
4524 // zap old sessions with same IP and/or username
4525 // Don't kill gardened sessions - doing so leads to a DoS
4526 // from someone who doesn't need to know the password
4527 {
4528 ip = session[s].ip;
4529 user = session[s].user;
4530 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4531 {
4532 if (i == s) continue;
4533 if (!session[s].opened) continue;
4534 if (ip == session[i].ip)
4535 {
4536 sessionkill(i, "Duplicate IP address");
4537 continue;
4538 }
4539
4540 if (config->allow_duplicate_users) continue;
4541 if (session[s].walled_garden || session[i].walled_garden) continue;
4542 if (!strcasecmp(user, session[i].user))
4543 sessionkill(i, "Duplicate session for users");
4544 }
4545 }
4546
4547 {
4548 int routed = 0;
4549
4550 // Add the route for this session.
4551 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4552 {
4553 if ((session[s].ip & session[s].route[r].mask) ==
4554 (session[s].route[r].ip & session[s].route[r].mask))
4555 routed++;
4556
4557 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4558 }
4559
4560 // Static IPs need to be routed if not already
4561 // convered by a Framed-Route. Anything else is part
4562 // of the IP address pool and is already routed, it
4563 // just needs to be added to the IP cache.
4564 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4565 if (session[s].ip_pool_index == -1) // static ip
4566 {
4567 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4568 }
4569 else
4570 cache_ipmap(session[s].ip, s);
4571 }
4572
4573 sess_local[s].lcp_authtype = 0; // RADIUS authentication complete
4574 lcp_open(s, t); // transition to Network phase and send initial IPCP
4575
4576 // Run the plugin's against this new session.
4577 {
4578 struct param_new_session data = { &tunnel[t], &session[s] };
4579 run_plugins(PLUGIN_NEW_SESSION, &data);
4580 }
4581
4582 // Allocate TBFs if throttled
4583 if (session[s].throttle_in || session[s].throttle_out)
4584 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4585
4586 session[s].last_packet = time_now;
4587
4588 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4589 fmtaddr(htonl(session[s].ip), 0),
4590 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4591
4592 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4593
4594 return 1; // RADIUS OK and IP allocated, done...
4595 }
4596
4597 //
4598 // This session just got dropped on us by the master or something.
4599 // Make sure our tables up up to date...
4600 //
4601 int load_session(sessionidt s, sessiont *new)
4602 {
4603 int i;
4604 int newip = 0;
4605
4606 // Sanity checks.
4607 if (new->ip_pool_index >= MAXIPPOOL ||
4608 new->tunnel >= MAXTUNNEL)
4609 {
4610 LOG(0, s, 0, "Strange session update received!\n");
4611 // FIXME! What to do here?
4612 return 0;
4613 }
4614
4615 //
4616 // Ok. All sanity checks passed. Now we're committed to
4617 // loading the new session.
4618 //
4619
4620 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4621
4622 // See if routes/ip cache need updating
4623 if (new->ip != session[s].ip)
4624 newip++;
4625
4626 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4627 if (new->route[i].ip != session[s].route[i].ip ||
4628 new->route[i].mask != session[s].route[i].mask)
4629 newip++;
4630
4631 // needs update
4632 if (newip)
4633 {
4634 int routed = 0;
4635
4636 // remove old routes...
4637 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4638 {
4639 if ((session[s].ip & session[s].route[i].mask) ==
4640 (session[s].route[i].ip & session[s].route[i].mask))
4641 routed++;
4642
4643 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4644 }
4645
4646 // ...ip
4647 if (session[s].ip)
4648 {
4649 if (session[s].ip_pool_index == -1) // static IP
4650 {
4651 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4652 }
4653 else // It's part of the IP pool, remove it manually.
4654 uncache_ipmap(session[s].ip);
4655 }
4656
4657 routed = 0;
4658
4659 // add new routes...
4660 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4661 {
4662 if ((new->ip & new->route[i].mask) ==
4663 (new->route[i].ip & new->route[i].mask))
4664 routed++;
4665
4666 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4667 }
4668
4669 // ...ip
4670 if (new->ip)
4671 {
4672 // If there's a new one, add it.
4673 if (new->ip_pool_index == -1)
4674 {
4675 if (!routed) routeset(s, new->ip, 0, 0, 1);
4676 }
4677 else
4678 cache_ipmap(new->ip, s);
4679 }
4680 }
4681
4682 // check v6 routing
4683 if (new->ipv6prefixlen && new->ppp.ipv6cp == Opened && session[s].ppp.ipv6cp != Opened)
4684 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4685
4686 // check filters
4687 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4688 {
4689 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4690 new->filter_in = 0;
4691 }
4692
4693 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4694 {
4695 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4696 new->filter_out = 0;
4697 }
4698
4699 if (new->filter_in != session[s].filter_in)
4700 {
4701 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4702 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4703 }
4704
4705 if (new->filter_out != session[s].filter_out)
4706 {
4707 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4708 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4709 }
4710
4711 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4712 // for walking the sessions to forward byte counts to the master.
4713 config->cluster_highest_sessionid = s;
4714
4715 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4716
4717 // Do fixups into address pool.
4718 if (new->ip_pool_index != -1)
4719 fix_address_pool(s);
4720
4721 return 1;
4722 }
4723
4724 static void initplugins()
4725 {
4726 int i;
4727
4728 loaded_plugins = ll_init();
4729 // Initialize the plugins to nothing
4730 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4731 plugins[i] = ll_init();
4732 }
4733
4734 static void *open_plugin(char *plugin_name, int load)
4735 {
4736 char path[256] = "";
4737
4738 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4739 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4740 return dlopen(path, RTLD_NOW);
4741 }
4742
4743 // plugin callback to get a config value
4744 static void *getconfig(char *key, enum config_typet type)
4745 {
4746 int i;
4747
4748 for (i = 0; config_values[i].key; i++)
4749 {
4750 if (!strcmp(config_values[i].key, key))
4751 {
4752 if (config_values[i].type == type)
4753 return ((void *) config) + config_values[i].offset;
4754
4755 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4756 key, type, config_values[i].type);
4757
4758 return 0;
4759 }
4760 }
4761
4762 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4763 return 0;
4764 }
4765
4766 static int add_plugin(char *plugin_name)
4767 {
4768 static struct pluginfuncs funcs = {
4769 _log,
4770 _log_hex,
4771 fmtaddr,
4772 sessionbyuser,
4773 sessiontbysessionidt,
4774 sessionidtbysessiont,
4775 radiusnew,
4776 radiussend,
4777 getconfig,
4778 sessionshutdown,
4779 sessionkill,
4780 throttle_session,
4781 cluster_send_session,
4782 };
4783
4784 void *p = open_plugin(plugin_name, 1);
4785 int (*initfunc)(struct pluginfuncs *);
4786 int i;
4787
4788 if (!p)
4789 {
4790 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4791 return -1;
4792 }
4793
4794 if (ll_contains(loaded_plugins, p))
4795 {
4796 dlclose(p);
4797 return 0; // already loaded
4798 }
4799
4800 {
4801 int *v = dlsym(p, "plugin_api_version");
4802 if (!v || *v != PLUGIN_API_VERSION)
4803 {
4804 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4805 dlclose(p);
4806 return -1;
4807 }
4808 }
4809
4810 if ((initfunc = dlsym(p, "plugin_init")))
4811 {
4812 if (!initfunc(&funcs))
4813 {
4814 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4815 dlclose(p);
4816 return -1;
4817 }
4818 }
4819
4820 ll_push(loaded_plugins, p);
4821
4822 for (i = 0; i < max_plugin_functions; i++)
4823 {
4824 void *x;
4825 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4826 {
4827 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4828 ll_push(plugins[i], x);
4829 }
4830 }
4831
4832 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4833 return 1;
4834 }
4835
4836 static void run_plugin_done(void *plugin)
4837 {
4838 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4839
4840 if (donefunc)
4841 donefunc();
4842 }
4843
4844 static int remove_plugin(char *plugin_name)
4845 {
4846 void *p = open_plugin(plugin_name, 0);
4847 int loaded = 0;
4848
4849 if (!p)
4850 return -1;
4851
4852 if (ll_contains(loaded_plugins, p))
4853 {
4854 int i;
4855 for (i = 0; i < max_plugin_functions; i++)
4856 {
4857 void *x;
4858 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4859 ll_delete(plugins[i], x);
4860 }
4861
4862 ll_delete(loaded_plugins, p);
4863 run_plugin_done(p);
4864 loaded = 1;
4865 }
4866
4867 dlclose(p);
4868 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4869 return loaded;
4870 }
4871
4872 int run_plugins(int plugin_type, void *data)
4873 {
4874 int (*func)(void *data);
4875
4876 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4877 return PLUGIN_RET_ERROR;
4878
4879 ll_reset(plugins[plugin_type]);
4880 while ((func = ll_next(plugins[plugin_type])))
4881 {
4882 int r = func(data);
4883
4884 if (r != PLUGIN_RET_OK)
4885 return r; // stop here
4886 }
4887
4888 return PLUGIN_RET_OK;
4889 }
4890
4891 static void plugins_done()
4892 {
4893 void *p;
4894
4895 ll_reset(loaded_plugins);
4896 while ((p = ll_next(loaded_plugins)))
4897 run_plugin_done(p);
4898 }
4899
4900 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen)
4901 {
4902 struct nsctl request;
4903 struct nsctl response;
4904 int type = unpack_control(&request, buf, len);
4905 int r;
4906 void *p;
4907
4908 if (log_stream && config->debug >= 4)
4909 {
4910 if (type < 0)
4911 {
4912 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4913 fmtaddr(addr->sin_addr.s_addr, 0), type);
4914 }
4915 else
4916 {
4917 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4918 dump_control(&request, log_stream);
4919 }
4920 }
4921
4922 switch (type)
4923 {
4924 case NSCTL_REQ_LOAD:
4925 if (request.argc != 1)
4926 {
4927 response.type = NSCTL_RES_ERR;
4928 response.argc = 1;
4929 response.argv[0] = "name of plugin required";
4930 }
4931 else if ((r = add_plugin(request.argv[0])) < 1)
4932 {
4933 response.type = NSCTL_RES_ERR;
4934 response.argc = 1;
4935 response.argv[0] = !r
4936 ? "plugin already loaded"
4937 : "error loading plugin";
4938 }
4939 else
4940 {
4941 response.type = NSCTL_RES_OK;
4942 response.argc = 0;
4943 }
4944
4945 break;
4946
4947 case NSCTL_REQ_UNLOAD:
4948 if (request.argc != 1)
4949 {
4950 response.type = NSCTL_RES_ERR;
4951 response.argc = 1;
4952 response.argv[0] = "name of plugin required";
4953 }
4954 else if ((r = remove_plugin(request.argv[0])) < 1)
4955 {
4956 response.type = NSCTL_RES_ERR;
4957 response.argc = 1;
4958 response.argv[0] = !r
4959 ? "plugin not loaded"
4960 : "plugin not found";
4961 }
4962 else
4963 {
4964 response.type = NSCTL_RES_OK;
4965 response.argc = 0;
4966 }
4967
4968 break;
4969
4970 case NSCTL_REQ_HELP:
4971 response.type = NSCTL_RES_OK;
4972 response.argc = 0;
4973
4974 ll_reset(loaded_plugins);
4975 while ((p = ll_next(loaded_plugins)))
4976 {
4977 char **help = dlsym(p, "plugin_control_help");
4978 while (response.argc < 0xff && help && *help)
4979 response.argv[response.argc++] = *help++;
4980 }
4981
4982 break;
4983
4984 case NSCTL_REQ_CONTROL:
4985 {
4986 struct param_control param = {
4987 config->cluster_iam_master,
4988 request.argc,
4989 request.argv,
4990 0,
4991 NULL,
4992 };
4993
4994 int r = run_plugins(PLUGIN_CONTROL, &param);
4995
4996 if (r == PLUGIN_RET_ERROR)
4997 {
4998 response.type = NSCTL_RES_ERR;
4999 response.argc = 1;
5000 response.argv[0] = param.additional
5001 ? param.additional
5002 : "error returned by plugin";
5003 }
5004 else if (r == PLUGIN_RET_NOTMASTER)
5005 {
5006 static char msg[] = "must be run on master: 000.000.000.000";
5007
5008 response.type = NSCTL_RES_ERR;
5009 response.argc = 1;
5010 if (config->cluster_master_address)
5011 {
5012 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
5013 response.argv[0] = msg;
5014 }
5015 else
5016 {
5017 response.argv[0] = "must be run on master: none elected";
5018 }
5019 }
5020 else if (!(param.response & NSCTL_RESPONSE))
5021 {
5022 response.type = NSCTL_RES_ERR;
5023 response.argc = 1;
5024 response.argv[0] = param.response
5025 ? "unrecognised response value from plugin"
5026 : "unhandled action";
5027 }
5028 else
5029 {
5030 response.type = param.response;
5031 response.argc = 0;
5032 if (param.additional)
5033 {
5034 response.argc = 1;
5035 response.argv[0] = param.additional;
5036 }
5037 }
5038 }
5039
5040 break;
5041
5042 default:
5043 response.type = NSCTL_RES_ERR;
5044 response.argc = 1;
5045 response.argv[0] = "error unpacking control packet";
5046 }
5047
5048 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
5049 if (!buf)
5050 {
5051 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
5052 return;
5053 }
5054
5055 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
5056 if (r > 0)
5057 {
5058 sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
5059 if (log_stream && config->debug >= 4)
5060 {
5061 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
5062 dump_control(&response, log_stream);
5063 }
5064 }
5065 else
5066 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
5067 fmtaddr(addr->sin_addr.s_addr, 0), r);
5068
5069 free(buf);
5070 }
5071
5072 static tunnelidt new_tunnel()
5073 {
5074 tunnelidt i;
5075 for (i = 1; i < MAXTUNNEL; i++)
5076 {
5077 if (tunnel[i].state == TUNNELFREE)
5078 {
5079 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
5080 if (i > config->cluster_highest_tunnelid)
5081 config->cluster_highest_tunnelid = i;
5082 return i;
5083 }
5084 }
5085 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
5086 return 0;
5087 }
5088
5089 //
5090 // We're becoming the master. Do any required setup..
5091 //
5092 // This is principally telling all the plugins that we're
5093 // now a master, and telling them about all the sessions
5094 // that are active too..
5095 //
5096 void become_master(void)
5097 {
5098 int s, i;
5099 static struct event_data d[RADIUS_FDS];
5100 struct epoll_event e;
5101
5102 run_plugins(PLUGIN_BECOME_MASTER, NULL);
5103
5104 // running a bunch of iptables commands is slow and can cause
5105 // the master to drop tunnels on takeover--kludge around the
5106 // problem by forking for the moment (note: race)
5107 if (!fork_and_close())
5108 {
5109 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5110 {
5111 if (!session[s].opened) // Not an in-use session.
5112 continue;
5113
5114 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
5115 }
5116 exit(0);
5117 }
5118
5119 // add radius fds
5120 e.events = EPOLLIN;
5121 for (i = 0; i < RADIUS_FDS; i++)
5122 {
5123 d[i].type = FD_TYPE_RADIUS;
5124 d[i].index = i;
5125 e.data.ptr = &d[i];
5126
5127 epoll_ctl(epollfd, EPOLL_CTL_ADD, radfds[i], &e);
5128 }
5129 }
5130
5131 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
5132 {
5133 int s, i;
5134 int count = 0;
5135 int buckets[64];
5136
5137 if (CLI_HELP_REQUESTED)
5138 return CLI_HELP_NO_ARGS;
5139
5140 time(&time_now);
5141 for (i = 0; i < 64;++i) buckets[i] = 0;
5142
5143 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5144 {
5145 int idle;
5146 if (!session[s].opened)
5147 continue;
5148
5149 idle = time_now - session[s].last_packet;
5150 idle /= 5 ; // In multiples of 5 seconds.
5151 if (idle < 0)
5152 idle = 0;
5153 if (idle > 63)
5154 idle = 63;
5155
5156 ++count;
5157 ++buckets[idle];
5158 }
5159
5160 for (i = 0; i < 63; ++i)
5161 {
5162 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
5163 }
5164 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
5165 cli_print(cli, "%d total sessions open.", count);
5166 return CLI_OK;
5167 }
5168
5169 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
5170 {
5171 int s, i;
5172 int count = 0;
5173 int buckets[64];
5174
5175 if (CLI_HELP_REQUESTED)
5176 return CLI_HELP_NO_ARGS;
5177
5178 time(&time_now);
5179 for (i = 0; i < 64;++i) buckets[i] = 0;
5180
5181 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5182 {
5183 int open = 0, d;
5184 if (!session[s].opened)
5185 continue;
5186
5187 d = time_now - session[s].opened;
5188 if (d < 0)
5189 d = 0;
5190 while (d > 1 && open < 32)
5191 {
5192 ++open;
5193 d >>= 1; // half.
5194 }
5195 ++count;
5196 ++buckets[open];
5197 }
5198
5199 s = 1;
5200 for (i = 0; i < 30; ++i)
5201 {
5202 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
5203 s <<= 1;
5204 }
5205 cli_print(cli, "%d total sessions open.", count);
5206 return CLI_OK;
5207 }
5208
5209 /* Unhide an avp.
5210 *
5211 * This unencodes the AVP using the L2TP secret and the previously
5212 * stored random vector. It overwrites the hidden data with the
5213 * unhidden AVP subformat.
5214 */
5215 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
5216 {
5217 MD5_CTX ctx;
5218 uint8_t digest[16];
5219 uint8_t *last;
5220 size_t d = 0;
5221 uint16_t m = htons(type);
5222
5223 // Compute initial pad
5224 MD5_Init(&ctx);
5225 MD5_Update(&ctx, (unsigned char *) &m, 2);
5226 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
5227 MD5_Update(&ctx, vector, vec_len);
5228 MD5_Final(digest, &ctx);
5229
5230 // pointer to last decoded 16 octets
5231 last = value;
5232
5233 while (len > 0)
5234 {
5235 // calculate a new pad based on the last decoded block
5236 if (d >= sizeof(digest))
5237 {
5238 MD5_Init(&ctx);
5239 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
5240 MD5_Update(&ctx, last, sizeof(digest));
5241 MD5_Final(digest, &ctx);
5242
5243 d = 0;
5244 last = value;
5245 }
5246
5247 *value++ ^= digest[d++];
5248 len--;
5249 }
5250 }
5251
5252 int find_filter(char const *name, size_t len)
5253 {
5254 int free = -1;
5255 int i;
5256
5257 for (i = 0; i < MAXFILTER; i++)
5258 {
5259 if (!*ip_filters[i].name)
5260 {
5261 if (free < 0)
5262 free = i;
5263
5264 continue;
5265 }
5266
5267 if (strlen(ip_filters[i].name) != len)
5268 continue;
5269
5270 if (!strncmp(ip_filters[i].name, name, len))
5271 return i;
5272 }
5273
5274 return free;
5275 }
5276
5277 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
5278 {
5279 switch (p->op)
5280 {
5281 case FILTER_PORT_OP_EQ: return port == p->port;
5282 case FILTER_PORT_OP_NEQ: return port != p->port;
5283 case FILTER_PORT_OP_GT: return port > p->port;
5284 case FILTER_PORT_OP_LT: return port < p->port;
5285 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
5286 }
5287
5288 return 0;
5289 }
5290
5291 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
5292 {
5293 switch (op)
5294 {
5295 case FILTER_FLAG_OP_ANY:
5296 return (flags & sflags) || (~flags & cflags);
5297
5298 case FILTER_FLAG_OP_ALL:
5299 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
5300
5301 case FILTER_FLAG_OP_EST:
5302 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
5303 }
5304
5305 return 0;
5306 }
5307
5308 int ip_filter(uint8_t *buf, int len, uint8_t filter)
5309 {
5310 uint16_t frag_offset;
5311 uint8_t proto;
5312 in_addr_t src_ip;
5313 in_addr_t dst_ip;
5314 uint16_t src_port = 0;
5315 uint16_t dst_port = 0;
5316 uint8_t flags = 0;
5317 ip_filter_rulet *rule;
5318
5319 if (len < 20) // up to end of destination address
5320 return 0;
5321
5322 if ((*buf >> 4) != 4) // IPv4
5323 return 0;
5324
5325 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
5326 proto = buf[9];
5327 src_ip = *(in_addr_t *) (buf + 12);
5328 dst_ip = *(in_addr_t *) (buf + 16);
5329
5330 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
5331 {
5332 int l = (buf[0] & 0xf) * 4; // length of IP header
5333 if (len < l + 4) // ports
5334 return 0;
5335
5336 src_port = ntohs(*(uint16_t *) (buf + l));
5337 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
5338 if (proto == IPPROTO_TCP)
5339 {
5340 if (len < l + 14) // flags
5341 return 0;
5342
5343 flags = buf[l + 13] & 0x3f;
5344 }
5345 }
5346
5347 for (rule = ip_filters[filter].rules; rule->action; rule++)
5348 {
5349 if (rule->proto != IPPROTO_IP && proto != rule->proto)
5350 continue;
5351
5352 if (rule->src_wild != INADDR_BROADCAST &&
5353 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
5354 continue;
5355
5356 if (rule->dst_wild != INADDR_BROADCAST &&
5357 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
5358 continue;
5359
5360 if (frag_offset)
5361 {
5362 if (!rule->frag || rule->action == FILTER_ACTION_DENY)
5363 continue;
5364 }
5365 else
5366 {
5367 if (rule->frag)
5368 continue;
5369
5370 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
5371 {
5372 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
5373 continue;
5374
5375 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
5376 continue;
5377
5378 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
5379 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
5380 continue;
5381 }
5382 }
5383
5384 // matched
5385 rule->counter++;
5386 return rule->action == FILTER_ACTION_PERMIT;
5387 }
5388
5389 // default deny
5390 return 0;
5391 }