7c9adbe53a952918abf93904664e4407b2979e6e
[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 1.159 2006-04-05 02:13:48 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 static int time_changed = 0; // time_now changed
100 char main_quit = 0; // True if we're in the process of exiting.
101 static 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, struct in_addr *local);
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 /* set MTU to modem MRU */
558 ifr.ifr_mtu = MRU;
559 if (ioctl(ifrfd, SIOCSIFMTU, (void *) &ifr) < 0)
560 {
561 LOG(0, 0, 0, "Error setting tun MTU: %s\n", strerror(errno));
562 exit(1);
563 }
564 ifr.ifr_flags = IFF_UP;
565 if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
566 {
567 LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
568 exit(1);
569 }
570 if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
571 {
572 LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
573 exit(1);
574 }
575 tunidx = ifr.ifr_ifindex;
576
577 // Only setup IPv6 on the tun device if we have a configured prefix
578 if (config->ipv6_prefix.s6_addr[0]) {
579 ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0);
580
581 // Link local address is FE80::1
582 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
583 ifr6.ifr6_addr.s6_addr[0] = 0xFE;
584 ifr6.ifr6_addr.s6_addr[1] = 0x80;
585 ifr6.ifr6_addr.s6_addr[15] = 1;
586 ifr6.ifr6_prefixlen = 64;
587 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
588 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
589 {
590 LOG(0, 0, 0, "Error setting tun IPv6 link local address:"
591 " %s\n", strerror(errno));
592 }
593
594 // Global address is prefix::1
595 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
596 ifr6.ifr6_addr = config->ipv6_prefix;
597 ifr6.ifr6_addr.s6_addr[15] = 1;
598 ifr6.ifr6_prefixlen = 64;
599 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
600 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
601 {
602 LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n",
603 strerror(errno));
604 }
605 }
606 }
607
608 // set up UDP ports
609 static void initudp(void)
610 {
611 int on = 1;
612 struct sockaddr_in addr;
613
614 // Tunnel
615 memset(&addr, 0, sizeof(addr));
616 addr.sin_family = AF_INET;
617 addr.sin_port = htons(L2TPPORT);
618 addr.sin_addr.s_addr = config->bind_address;
619 udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
620 setsockopt(udpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
621 {
622 int flags = fcntl(udpfd, F_GETFL, 0);
623 fcntl(udpfd, F_SETFL, flags | O_NONBLOCK);
624 }
625 if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
626 {
627 LOG(0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
628 exit(1);
629 }
630
631 // Control
632 memset(&addr, 0, sizeof(addr));
633 addr.sin_family = AF_INET;
634 addr.sin_port = htons(NSCTL_PORT);
635 controlfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
636 setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
637 setsockopt(controlfd, SOL_IP, IP_PKTINFO, &on, sizeof(on)); // recvfromto
638 if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
639 {
640 LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
641 exit(1);
642 }
643
644 // Dynamic Authorization Extensions to RADIUS
645 memset(&addr, 0, sizeof(addr));
646 addr.sin_family = AF_INET;
647 addr.sin_port = htons(config->radius_dae_port);
648 daefd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
649 setsockopt(daefd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
650 setsockopt(daefd, SOL_IP, IP_PKTINFO, &on, sizeof(on)); // recvfromto
651 if (bind(daefd, (void *) &addr, sizeof(addr)) < 0)
652 {
653 LOG(0, 0, 0, "Error in DAE bind: %s\n", strerror(errno));
654 exit(1);
655 }
656
657 // Intercept
658 snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
659 }
660
661 //
662 // Find session by IP, < 1 for not found
663 //
664 // Confusingly enough, this 'ip' must be
665 // in _network_ order. This being the common
666 // case when looking it up from IP packet headers.
667 //
668 // We actually use this cache for two things.
669 // #1. For used IP addresses, this maps to the
670 // session ID that it's used by.
671 // #2. For un-used IP addresses, this maps to the
672 // index into the pool table that contains that
673 // IP address.
674 //
675
676 static int lookup_ipmap(in_addr_t ip)
677 {
678 uint8_t *a = (uint8_t *) &ip;
679 uint8_t **d = (uint8_t **) ip_hash;
680
681 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
682 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
683 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
684
685 return (int) (intptr_t) d[(size_t) *a];
686 }
687
688 static int lookup_ipv6map(struct in6_addr ip)
689 {
690 struct ipv6radix *curnode;
691 int i;
692 int s;
693 char ipv6addr[INET6_ADDRSTRLEN];
694
695 curnode = &ipv6_hash[ip.s6_addr[0]];
696 i = 1;
697 s = curnode->sess;
698
699 while (s == 0 && i < 15 && curnode->branch != NULL)
700 {
701 curnode = &curnode->branch[ip.s6_addr[i]];
702 s = curnode->sess;
703 i++;
704 }
705
706 LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
707 inet_ntop(AF_INET6, &ip, ipv6addr,
708 INET6_ADDRSTRLEN),
709 s);
710
711 return s;
712 }
713
714 sessionidt sessionbyip(in_addr_t ip)
715 {
716 int s = lookup_ipmap(ip);
717 CSTAT(sessionbyip);
718
719 if (s > 0 && s < MAXSESSION && session[s].opened)
720 return (sessionidt) s;
721
722 return 0;
723 }
724
725 sessionidt sessionbyipv6(struct in6_addr ip)
726 {
727 int s;
728 CSTAT(sessionbyipv6);
729
730 if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
731 (ip.s6_addr[0] == 0xFE &&
732 ip.s6_addr[1] == 0x80 &&
733 ip.s6_addr16[1] == 0 &&
734 ip.s6_addr16[2] == 0 &&
735 ip.s6_addr16[3] == 0)) {
736 s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
737 } else {
738 s = lookup_ipv6map(ip);
739 }
740
741 if (s > 0 && s < MAXSESSION && session[s].opened)
742 return s;
743
744 return 0;
745 }
746
747 //
748 // Take an IP address in HOST byte order and
749 // add it to the sessionid by IP cache.
750 //
751 // (It's actually cached in network order)
752 //
753 static void cache_ipmap(in_addr_t ip, int s)
754 {
755 in_addr_t nip = htonl(ip); // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
756 uint8_t *a = (uint8_t *) &nip;
757 uint8_t **d = (uint8_t **) ip_hash;
758 int i;
759
760 for (i = 0; i < 3; i++)
761 {
762 if (!d[(size_t) a[i]])
763 {
764 if (!(d[(size_t) a[i]] = calloc(256, sizeof(void *))))
765 return;
766 }
767
768 d = (uint8_t **) d[(size_t) a[i]];
769 }
770
771 d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
772
773 if (s > 0)
774 LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
775
776 else if (s == 0)
777 LOG(4, 0, 0, "Un-caching ip address %s\n", fmtaddr(nip, 0));
778 // else a map to an ip pool index.
779 }
780
781 static void uncache_ipmap(in_addr_t ip)
782 {
783 cache_ipmap(ip, 0); // Assign it to the NULL session.
784 }
785
786 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
787 {
788 int i;
789 int bytes;
790 struct ipv6radix *curnode;
791 char ipv6addr[INET6_ADDRSTRLEN];
792
793 curnode = &ipv6_hash[ip.s6_addr[0]];
794
795 bytes = prefixlen >> 3;
796 i = 1;
797 while (i < bytes) {
798 if (curnode->branch == NULL)
799 {
800 if (!(curnode->branch = calloc(256,
801 sizeof (struct ipv6radix))))
802 return;
803 }
804 curnode = &curnode->branch[ip.s6_addr[i]];
805 i++;
806 }
807
808 curnode->sess = s;
809
810 if (s > 0)
811 LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
812 inet_ntop(AF_INET6, &ip, ipv6addr,
813 INET6_ADDRSTRLEN),
814 prefixlen);
815 else if (s == 0)
816 LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
817 inet_ntop(AF_INET6, &ip, ipv6addr,
818 INET6_ADDRSTRLEN),
819 prefixlen);
820 }
821
822 //
823 // CLI list to dump current ipcache.
824 //
825 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
826 {
827 char **d = (char **) ip_hash, **e, **f, **g;
828 int i, j, k, l;
829 int count = 0;
830
831 if (CLI_HELP_REQUESTED)
832 return CLI_HELP_NO_ARGS;
833
834 cli_print(cli, "%7s %s", "Sess#", "IP Address");
835
836 for (i = 0; i < 256; ++i)
837 {
838 if (!d[i])
839 continue;
840 e = (char **) d[i];
841 for (j = 0; j < 256; ++j)
842 {
843 if (!e[j])
844 continue;
845 f = (char **) e[j];
846 for (k = 0; k < 256; ++k)
847 {
848 if (!f[k])
849 continue;
850 g = (char **)f[k];
851 for (l = 0; l < 256; ++l)
852 {
853 if (!g[l])
854 continue;
855 cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
856 ++count;
857 }
858 }
859 }
860 }
861 cli_print(cli, "%d entries in cache", count);
862 return CLI_OK;
863 }
864
865
866 // Find session by username, 0 for not found
867 // walled garden users aren't authenticated, so the username is
868 // reasonably useless. Ignore them to avoid incorrect actions
869 //
870 // This is VERY inefficent. Don't call it often. :)
871 //
872 sessionidt sessionbyuser(char *username)
873 {
874 int s;
875 CSTAT(sessionbyuser);
876
877 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
878 {
879 if (!session[s].opened)
880 continue;
881
882 if (session[s].walled_garden)
883 continue; // Skip walled garden users.
884
885 if (!strncmp(session[s].user, username, 128))
886 return s;
887
888 }
889 return 0; // Not found.
890 }
891
892 void send_garp(in_addr_t ip)
893 {
894 int s;
895 struct ifreq ifr;
896 uint8_t mac[6];
897
898 s = socket(PF_INET, SOCK_DGRAM, 0);
899 if (s < 0)
900 {
901 LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
902 return;
903 }
904 memset(&ifr, 0, sizeof(ifr));
905 strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
906 if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
907 {
908 LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
909 close(s);
910 return;
911 }
912 memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
913 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
914 {
915 LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
916 close(s);
917 return;
918 }
919 close(s);
920 sendarp(ifr.ifr_ifindex, mac, ip);
921 }
922
923 static sessiont *sessiontbysessionidt(sessionidt s)
924 {
925 if (!s || s >= MAXSESSION) return NULL;
926 return &session[s];
927 }
928
929 static sessionidt sessionidtbysessiont(sessiont *s)
930 {
931 sessionidt val = s-session;
932 if (s < session || val >= MAXSESSION) return 0;
933 return val;
934 }
935
936 // actually send a control message for a specific tunnel
937 void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
938 {
939 struct sockaddr_in addr;
940
941 CSTAT(tunnelsend);
942
943 if (!t)
944 {
945 LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
946 STAT(tunnel_tx_errors);
947 return;
948 }
949
950 if (!tunnel[t].ip)
951 {
952 LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
953 STAT(tunnel_tx_errors);
954 return;
955 }
956
957 memset(&addr, 0, sizeof(addr));
958 addr.sin_family = AF_INET;
959 *(uint32_t *) & addr.sin_addr = htonl(tunnel[t].ip);
960 addr.sin_port = htons(tunnel[t].port);
961
962 // sequence expected, if sequence in message
963 if (*buf & 0x08) *(uint16_t *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
964
965 // If this is a control message, deal with retries
966 if (*buf & 0x80)
967 {
968 tunnel[t].last = time_now; // control message sent
969 tunnel[t].retry = backoff(tunnel[t].try); // when to resend
970 if (tunnel[t].try)
971 {
972 STAT(tunnel_retries);
973 LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
974 }
975 }
976
977 if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
978 {
979 LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
980 strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
981 STAT(tunnel_tx_errors);
982 return;
983 }
984
985 LOG_HEX(5, "Send Tunnel Data", buf, l);
986 STAT(tunnel_tx_packets);
987 INC_STAT(tunnel_tx_bytes, l);
988 }
989
990 //
991 // Tiny helper function to write data to
992 // the 'tun' device.
993 //
994 int tun_write(uint8_t * data, int size)
995 {
996 return write(tunfd, data, size);
997 }
998
999 // adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
1000 void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
1001 {
1002 int d = (tcp[12] >> 4) * 4;
1003 uint8_t *mss = 0;
1004 uint8_t *opts;
1005 uint8_t *data;
1006 uint16_t orig;
1007 uint32_t sum;
1008
1009 if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
1010 return;
1011
1012 if (tcp + d > buf + len) // short?
1013 return;
1014
1015 opts = tcp + 20;
1016 data = tcp + d;
1017
1018 while (opts < data)
1019 {
1020 if (*opts == 2 && opts[1] == 4) // mss option (2), length 4
1021 {
1022 mss = opts + 2;
1023 if (mss + 2 > data) return; // short?
1024 break;
1025 }
1026
1027 if (*opts == 0) return; // end of options
1028 if (*opts == 1 || !opts[1]) // no op (one byte), or no length (prevent loop)
1029 opts++;
1030 else
1031 opts += opts[1]; // skip over option
1032 }
1033
1034 if (!mss) return; // not found
1035 orig = ntohs(*(uint16_t *) mss);
1036
1037 if (orig <= MSS) return; // mss OK
1038
1039 LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s: adjusted mss from %u to %u\n",
1040 fmtaddr(*(in_addr_t *) (buf + 12), 0), ntohs(*(uint16_t *) tcp),
1041 fmtaddr(*(in_addr_t *) (buf + 16), 1), ntohs(*(uint16_t *) (tcp + 2)),
1042 (tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "", orig, MSS);
1043
1044 // set mss
1045 *(int16_t *) mss = htons(MSS);
1046
1047 // adjust checksum (see rfc1141)
1048 sum = orig + (~MSS & 0xffff);
1049 sum += ntohs(*(uint16_t *) (tcp + 16));
1050 sum = (sum & 0xffff) + (sum >> 16);
1051 *(uint16_t *) (tcp + 16) = htons(sum + (sum >> 16));
1052 }
1053
1054 // process outgoing (to tunnel) IP
1055 //
1056 static void processipout(uint8_t *buf, int len)
1057 {
1058 sessionidt s;
1059 sessiont *sp;
1060 tunnelidt t;
1061 in_addr_t ip;
1062
1063 uint8_t *data = buf; // Keep a copy of the originals.
1064 int size = len;
1065
1066 uint8_t b[MAXETHER + 20];
1067
1068 CSTAT(processipout);
1069
1070 if (len < MIN_IP_SIZE)
1071 {
1072 LOG(1, 0, 0, "Short IP, %d bytes\n", len);
1073 STAT(tun_rx_errors);
1074 return;
1075 }
1076 if (len >= MAXETHER)
1077 {
1078 LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
1079 STAT(tun_rx_errors);
1080 return;
1081 }
1082
1083 // Skip the tun header
1084 buf += 4;
1085 len -= 4;
1086
1087 // Got an IP header now
1088 if (*(uint8_t *)(buf) >> 4 != 4)
1089 {
1090 LOG(1, 0, 0, "IP: Don't understand anything except IPv4\n");
1091 return;
1092 }
1093
1094 ip = *(uint32_t *)(buf + 16);
1095 if (!(s = sessionbyip(ip)))
1096 {
1097 // Is this a packet for a session that doesn't exist?
1098 static int rate = 0; // Number of ICMP packets we've sent this second.
1099 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1100
1101 if (last != time_now)
1102 {
1103 last = time_now;
1104 rate = 0;
1105 }
1106
1107 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1108 {
1109 LOG(4, 0, 0, "IP: Sending ICMP host unreachable to %s\n", fmtaddr(*(in_addr_t *)(buf + 12), 0));
1110 host_unreachable(*(in_addr_t *)(buf + 12), *(uint16_t *)(buf + 4),
1111 config->bind_address ? config->bind_address : my_address, buf, len);
1112 }
1113 return;
1114 }
1115 t = session[s].tunnel;
1116 sp = &session[s];
1117
1118 // DoS prevention: enforce a maximum number of packets per 0.1s for a session
1119 if (config->max_packets > 0)
1120 {
1121 if (sess_local[s].last_packet_out == TIME)
1122 {
1123 int max = config->max_packets;
1124
1125 // All packets for throttled sessions are handled by the
1126 // master, so further limit by using the throttle rate.
1127 // A bit of a kludge, since throttle rate is in kbps,
1128 // but should still be generous given our average DSL
1129 // packet size is 200 bytes: a limit of 28kbps equates
1130 // to around 180 packets per second.
1131 if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
1132 max = sp->throttle_out;
1133
1134 if (++sess_local[s].packets_out > max)
1135 {
1136 sess_local[s].packets_dropped++;
1137 return;
1138 }
1139 }
1140 else
1141 {
1142 if (sess_local[s].packets_dropped)
1143 {
1144 INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
1145 LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
1146 sess_local[s].packets_dropped, sess_local[s].packets_out,
1147 fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
1148 sp->user);
1149 }
1150
1151 sess_local[s].last_packet_out = TIME;
1152 sess_local[s].packets_out = 1;
1153 sess_local[s].packets_dropped = 0;
1154 }
1155 }
1156
1157 // run access-list if any
1158 if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
1159 return;
1160
1161 // adjust MSS on SYN and SYN,ACK packets with options
1162 if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
1163 {
1164 int ihl = (buf[0] & 0xf) * 4; // length of IP header
1165 if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
1166 adjust_tcp_mss(s, t, buf, len, buf + ihl);
1167 }
1168
1169 if (sp->tbf_out)
1170 {
1171 // Are we throttling this session?
1172 if (config->cluster_iam_master)
1173 tbf_queue_packet(sp->tbf_out, data, size);
1174 else
1175 master_throttle_packet(sp->tbf_out, data, size);
1176 return;
1177 }
1178
1179 if (sp->walled_garden && !config->cluster_iam_master)
1180 {
1181 // We are walled-gardening this
1182 master_garden_packet(s, data, size);
1183 return;
1184 }
1185
1186 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1187
1188 // Add on L2TP header
1189 {
1190 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
1191 if (!p) return;
1192 tunnelsend(b, len + (p-b), t); // send it...
1193 }
1194
1195 // Snooping this session, send it to intercept box
1196 if (sp->snoop_ip && sp->snoop_port)
1197 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1198
1199 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1200 sp->cout_delta += len;
1201 sp->pout++;
1202 udp_tx += len;
1203
1204 sess_local[s].cout += len; // To send to master..
1205 sess_local[s].pout++;
1206 }
1207
1208 // process outgoing (to tunnel) IPv6
1209 //
1210 static void processipv6out(uint8_t * buf, int len)
1211 {
1212 sessionidt s;
1213 sessiont *sp;
1214 tunnelidt t;
1215 in_addr_t ip;
1216 struct in6_addr ip6;
1217
1218 uint8_t *data = buf; // Keep a copy of the originals.
1219 int size = len;
1220
1221 uint8_t b[MAXETHER + 20];
1222
1223 CSTAT(processipv6out);
1224
1225 if (len < MIN_IP_SIZE)
1226 {
1227 LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
1228 STAT(tunnel_tx_errors);
1229 return;
1230 }
1231 if (len >= MAXETHER)
1232 {
1233 LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
1234 STAT(tunnel_tx_errors);
1235 return;
1236 }
1237
1238 // Skip the tun header
1239 buf += 4;
1240 len -= 4;
1241
1242 // Got an IP header now
1243 if (*(uint8_t *)(buf) >> 4 != 6)
1244 {
1245 LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
1246 return;
1247 }
1248
1249 ip6 = *(struct in6_addr *)(buf+24);
1250 s = sessionbyipv6(ip6);
1251
1252 if (s == 0)
1253 {
1254 ip = *(uint32_t *)(buf + 32);
1255 s = sessionbyip(ip);
1256 }
1257
1258 if (s == 0)
1259 {
1260 // Is this a packet for a session that doesn't exist?
1261 static int rate = 0; // Number of ICMP packets we've sent this second.
1262 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1263
1264 if (last != time_now)
1265 {
1266 last = time_now;
1267 rate = 0;
1268 }
1269
1270 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1271 {
1272 // FIXME: Should send icmp6 host unreachable
1273 }
1274 return;
1275 }
1276 t = session[s].tunnel;
1277 sp = &session[s];
1278
1279 // FIXME: add DoS prevention/filters?
1280
1281 if (sp->tbf_out)
1282 {
1283 // Are we throttling this session?
1284 if (config->cluster_iam_master)
1285 tbf_queue_packet(sp->tbf_out, data, size);
1286 else
1287 master_throttle_packet(sp->tbf_out, data, size);
1288 return;
1289 }
1290 else if (sp->walled_garden && !config->cluster_iam_master)
1291 {
1292 // We are walled-gardening this
1293 master_garden_packet(s, data, size);
1294 return;
1295 }
1296
1297 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1298
1299 // Add on L2TP header
1300 {
1301 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIPV6);
1302 if (!p) return;
1303 tunnelsend(b, len + (p-b), t); // send it...
1304 }
1305
1306 // Snooping this session, send it to intercept box
1307 if (sp->snoop_ip && sp->snoop_port)
1308 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1309
1310 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1311 sp->cout_delta += len;
1312 sp->pout++;
1313 udp_tx += len;
1314
1315 sess_local[s].cout += len; // To send to master..
1316 sess_local[s].pout++;
1317 }
1318
1319 //
1320 // Helper routine for the TBF filters.
1321 // Used to send queued data in to the user!
1322 //
1323 static void send_ipout(sessionidt s, uint8_t *buf, int len)
1324 {
1325 sessiont *sp;
1326 tunnelidt t;
1327 in_addr_t ip;
1328
1329 uint8_t b[MAXETHER + 20];
1330
1331 if (len < 0 || len > MAXETHER)
1332 {
1333 LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
1334 return;
1335 }
1336
1337 // Skip the tun header
1338 buf += 4;
1339 len -= 4;
1340
1341 ip = *(in_addr_t *)(buf + 16);
1342
1343 if (!session[s].ip)
1344 return;
1345
1346 t = session[s].tunnel;
1347 sp = &session[s];
1348
1349 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1350
1351 // Add on L2TP header
1352 {
1353 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
1354 if (!p) return;
1355 tunnelsend(b, len + (p-b), t); // send it...
1356 }
1357
1358 // Snooping this session.
1359 if (sp->snoop_ip && sp->snoop_port)
1360 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1361
1362 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1363 sp->cout_delta += len;
1364 sp->pout++;
1365 udp_tx += len;
1366
1367 sess_local[s].cout += len; // To send to master..
1368 sess_local[s].pout++;
1369 }
1370
1371 // add an AVP (16 bit)
1372 static void control16(controlt * c, uint16_t avp, uint16_t val, uint8_t m)
1373 {
1374 uint16_t l = (m ? 0x8008 : 0x0008);
1375 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1376 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1377 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1378 *(uint16_t *) (c->buf + c->length + 6) = htons(val);
1379 c->length += 8;
1380 }
1381
1382 // add an AVP (32 bit)
1383 static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
1384 {
1385 uint16_t l = (m ? 0x800A : 0x000A);
1386 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1387 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1388 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1389 *(uint32_t *) (c->buf + c->length + 6) = htonl(val);
1390 c->length += 10;
1391 }
1392
1393 // add an AVP (string)
1394 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
1395 {
1396 uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
1397 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1398 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1399 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1400 memcpy(c->buf + c->length + 6, val, strlen(val));
1401 c->length += 6 + strlen(val);
1402 }
1403
1404 // add a binary AVP
1405 static void controlb(controlt * c, uint16_t avp, uint8_t *val, unsigned int len, uint8_t m)
1406 {
1407 uint16_t l = ((m ? 0x8000 : 0) + len + 6);
1408 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1409 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1410 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1411 memcpy(c->buf + c->length + 6, val, len);
1412 c->length += 6 + len;
1413 }
1414
1415 // new control connection
1416 static controlt *controlnew(uint16_t mtype)
1417 {
1418 controlt *c;
1419 if (!controlfree)
1420 c = malloc(sizeof(controlt));
1421 else
1422 {
1423 c = controlfree;
1424 controlfree = c->next;
1425 }
1426 assert(c);
1427 c->next = 0;
1428 *(uint16_t *) (c->buf + 0) = htons(0xC802); // flags/ver
1429 c->length = 12;
1430 control16(c, 0, mtype, 1);
1431 return c;
1432 }
1433
1434 // send zero block if nothing is waiting
1435 // (ZLB send).
1436 static void controlnull(tunnelidt t)
1437 {
1438 uint8_t buf[12];
1439 if (tunnel[t].controlc) // Messages queued; They will carry the ack.
1440 return;
1441
1442 *(uint16_t *) (buf + 0) = htons(0xC802); // flags/ver
1443 *(uint16_t *) (buf + 2) = htons(12); // length
1444 *(uint16_t *) (buf + 4) = htons(tunnel[t].far); // tunnel
1445 *(uint16_t *) (buf + 6) = htons(0); // session
1446 *(uint16_t *) (buf + 8) = htons(tunnel[t].ns); // sequence
1447 *(uint16_t *) (buf + 10) = htons(tunnel[t].nr); // sequence
1448 tunnelsend(buf, 12, t);
1449 }
1450
1451 // add a control message to a tunnel, and send if within window
1452 static void controladd(controlt *c, sessionidt far, tunnelidt t)
1453 {
1454 *(uint16_t *) (c->buf + 2) = htons(c->length); // length
1455 *(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
1456 *(uint16_t *) (c->buf + 6) = htons(far); // session
1457 *(uint16_t *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
1458 tunnel[t].ns++; // advance sequence
1459 // link in message in to queue
1460 if (tunnel[t].controlc)
1461 tunnel[t].controle->next = c;
1462 else
1463 tunnel[t].controls = c;
1464
1465 tunnel[t].controle = c;
1466 tunnel[t].controlc++;
1467
1468 // send now if space in window
1469 if (tunnel[t].controlc <= tunnel[t].window)
1470 {
1471 tunnel[t].try = 0; // first send
1472 tunnelsend(c->buf, c->length, t);
1473 }
1474 }
1475
1476 //
1477 // Throttle or Unthrottle a session
1478 //
1479 // Throttle the data from/to through a session to no more than
1480 // 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
1481 // user).
1482 //
1483 // If either value is -1, the current value is retained for that
1484 // direction.
1485 //
1486 void throttle_session(sessionidt s, int rate_in, int rate_out)
1487 {
1488 if (!session[s].opened)
1489 return; // No-one home.
1490
1491 if (!*session[s].user)
1492 return; // User not logged in
1493
1494 if (rate_in >= 0)
1495 {
1496 int bytes = rate_in * 1024 / 8; // kbits to bytes
1497 if (session[s].tbf_in)
1498 free_tbf(session[s].tbf_in);
1499
1500 if (rate_in > 0)
1501 session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
1502 else
1503 session[s].tbf_in = 0;
1504
1505 session[s].throttle_in = rate_in;
1506 }
1507
1508 if (rate_out >= 0)
1509 {
1510 int bytes = rate_out * 1024 / 8;
1511 if (session[s].tbf_out)
1512 free_tbf(session[s].tbf_out);
1513
1514 if (rate_out > 0)
1515 session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
1516 else
1517 session[s].tbf_out = 0;
1518
1519 session[s].throttle_out = rate_out;
1520 }
1521 }
1522
1523 // add/remove filters from session (-1 = no change)
1524 void filter_session(sessionidt s, int filter_in, int filter_out)
1525 {
1526 if (!session[s].opened)
1527 return; // No-one home.
1528
1529 if (!*session[s].user)
1530 return; // User not logged in
1531
1532 // paranoia
1533 if (filter_in > MAXFILTER) filter_in = -1;
1534 if (filter_out > MAXFILTER) filter_out = -1;
1535 if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
1536 if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
1537
1538 if (filter_in >= 0)
1539 {
1540 if (session[s].filter_in)
1541 ip_filters[session[s].filter_in - 1].used--;
1542
1543 if (filter_in > 0)
1544 ip_filters[filter_in - 1].used++;
1545
1546 session[s].filter_in = filter_in;
1547 }
1548
1549 if (filter_out >= 0)
1550 {
1551 if (session[s].filter_out)
1552 ip_filters[session[s].filter_out - 1].used--;
1553
1554 if (filter_out > 0)
1555 ip_filters[filter_out - 1].used++;
1556
1557 session[s].filter_out = filter_out;
1558 }
1559 }
1560
1561 // start tidy shutdown of session
1562 void sessionshutdown(sessionidt s, char *reason, int result, int error)
1563 {
1564 int walled_garden = session[s].walled_garden;
1565
1566
1567 CSTAT(sessionshutdown);
1568
1569 if (!session[s].opened)
1570 {
1571 LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
1572 return; // not a live session
1573 }
1574
1575 if (!session[s].die)
1576 {
1577 struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
1578 LOG(2, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
1579 run_plugins(PLUGIN_KILL_SESSION, &data);
1580 }
1581
1582 if (session[s].ip && !walled_garden && !session[s].die)
1583 {
1584 // RADIUS Stop message
1585 uint16_t r = radiusnew(s);
1586 if (r)
1587 {
1588 // stop, if not already trying
1589 if (radius[r].state != RADIUSSTOP)
1590 radiussend(r, RADIUSSTOP);
1591 }
1592 else
1593 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
1594
1595 // Save counters to dump to accounting file
1596 if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
1597 memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
1598 }
1599
1600 if (session[s].ip)
1601 { // IP allocated, clear and unroute
1602 int r;
1603 int routed = 0;
1604 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
1605 {
1606 if ((session[s].ip & session[s].route[r].mask) ==
1607 (session[s].route[r].ip & session[s].route[r].mask))
1608 routed++;
1609
1610 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
1611 session[s].route[r].ip = 0;
1612 }
1613
1614 if (session[s].ip_pool_index == -1) // static ip
1615 {
1616 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
1617 session[s].ip = 0;
1618 }
1619 else
1620 free_ip_address(s);
1621
1622 // unroute IPv6, if setup
1623 if (session[s].ppp.ipv6cp == Opened && session[s].ipv6prefixlen)
1624 route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
1625 }
1626
1627 if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
1628 throttle_session(s, 0, 0);
1629
1630 if (result)
1631 { // Send CDN
1632 controlt *c = controlnew(14); // sending CDN
1633 if (error)
1634 {
1635 uint8_t buf[4];
1636 *(uint16_t *) buf = htons(result);
1637 *(uint16_t *) (buf+2) = htons(error);
1638 controlb(c, 1, buf, 4, 1);
1639 }
1640 else
1641 control16(c, 1, result, 1);
1642
1643 control16(c, 14, s, 1); // assigned session (our end)
1644 controladd(c, session[s].far, session[s].tunnel); // send the message
1645 }
1646
1647 if (!session[s].die)
1648 session[s].die = TIME + 150; // Clean up in 15 seconds
1649
1650 // update filter refcounts
1651 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1652 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1653
1654 // clear PPP state
1655 memset(&session[s].ppp, 0, sizeof(session[s].ppp));
1656 sess_local[s].lcp.restart = 0;
1657 sess_local[s].ipcp.restart = 0;
1658 sess_local[s].ipv6cp.restart = 0;
1659 sess_local[s].ccp.restart = 0;
1660
1661 cluster_send_session(s);
1662 }
1663
1664 void sendipcp(sessionidt s, tunnelidt t)
1665 {
1666 uint8_t buf[MAXETHER];
1667 uint8_t *q;
1668
1669 CSTAT(sendipcp);
1670 LOG(3, s, t, "IPCP: send ConfigReq\n");
1671
1672 if (!session[s].unique_id)
1673 {
1674 if (!++last_id) ++last_id; // skip zero
1675 session[s].unique_id = last_id;
1676 }
1677
1678 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP);
1679 if (!q) return;
1680
1681 *q = ConfigReq;
1682 q[1] = session[s].unique_id & 0xf; // ID, dont care, we only send one type of request
1683 *(uint16_t *) (q + 2) = htons(10); // packet length
1684 q[4] = 3; // ip address option
1685 q[5] = 6; // option length
1686 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1687 config->bind_address ? config->bind_address :
1688 my_address; // send my IP
1689
1690 tunnelsend(buf, 10 + (q - buf), t); // send it
1691 restart_timer(s, ipcp);
1692 }
1693
1694 void sendipv6cp(sessionidt s, tunnelidt t)
1695 {
1696 uint8_t buf[MAXETHER];
1697 uint8_t *q;
1698
1699 CSTAT(sendipv6cp);
1700 LOG(3, s, t, "IPV6CP: send ConfigReq\n");
1701
1702 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP);
1703 if (!q) return;
1704
1705 *q = ConfigReq;
1706 q[1] = session[s].unique_id & 0xf; // ID, don't care, we
1707 // only send one type
1708 // of request
1709 *(uint16_t *) (q + 2) = htons(14);
1710 q[4] = 1; // interface identifier option
1711 q[5] = 10; // option length
1712 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1713 *(uint32_t *) (q + 10) = 0;
1714 q[13] = 1;
1715
1716 tunnelsend(buf, 14 + (q - buf), t); // send it
1717 restart_timer(s, ipv6cp);
1718 }
1719
1720 static void sessionclear(sessionidt s)
1721 {
1722 memset(&session[s], 0, sizeof(session[s]));
1723 memset(&sess_local[s], 0, sizeof(sess_local[s]));
1724 memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
1725
1726 session[s].tunnel = T_FREE; // Mark it as free.
1727 session[s].next = sessionfree;
1728 sessionfree = s;
1729 }
1730
1731 // kill a session now
1732 void sessionkill(sessionidt s, char *reason)
1733 {
1734
1735 CSTAT(sessionkill);
1736
1737 if (!session[s].opened) // not alive
1738 return;
1739
1740 if (session[s].next)
1741 {
1742 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1743 return;
1744 }
1745
1746 session[s].die = TIME;
1747 sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
1748 if (sess_local[s].radius)
1749 radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
1750
1751 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1752 sessionclear(s);
1753 cluster_send_session(s);
1754 }
1755
1756 static void tunnelclear(tunnelidt t)
1757 {
1758 if (!t) return;
1759 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1760 tunnel[t].state = TUNNELFREE;
1761 }
1762
1763 // kill a tunnel now
1764 static void tunnelkill(tunnelidt t, char *reason)
1765 {
1766 sessionidt s;
1767 controlt *c;
1768
1769 CSTAT(tunnelkill);
1770
1771 tunnel[t].state = TUNNELDIE;
1772
1773 // free control messages
1774 while ((c = tunnel[t].controls))
1775 {
1776 controlt * n = c->next;
1777 tunnel[t].controls = n;
1778 tunnel[t].controlc--;
1779 c->next = controlfree;
1780 controlfree = c;
1781 }
1782 // kill sessions
1783 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1784 if (session[s].tunnel == t)
1785 sessionkill(s, reason);
1786
1787 // free tunnel
1788 tunnelclear(t);
1789 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1790 cli_tunnel_actions[t].action = 0;
1791 cluster_send_tunnel(t);
1792 }
1793
1794 // shut down a tunnel cleanly
1795 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1796 {
1797 sessionidt s;
1798
1799 CSTAT(tunnelshutdown);
1800
1801 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1802 {
1803 // never set up, can immediately kill
1804 tunnelkill(t, reason);
1805 return;
1806 }
1807 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1808
1809 // close session
1810 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1811 if (session[s].tunnel == t)
1812 sessionshutdown(s, reason, 0, 0);
1813
1814 tunnel[t].state = TUNNELDIE;
1815 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1816 cluster_send_tunnel(t);
1817 // TBA - should we wait for sessions to stop?
1818 if (result)
1819 {
1820 controlt *c = controlnew(4); // sending StopCCN
1821 if (error)
1822 {
1823 uint8_t buf[64];
1824 int l = 4;
1825 *(uint16_t *) buf = htons(result);
1826 *(uint16_t *) (buf+2) = htons(error);
1827 if (msg)
1828 {
1829 int m = strlen(msg);
1830 if (m + 4 > sizeof(buf))
1831 m = sizeof(buf) - 4;
1832
1833 memcpy(buf+4, msg, m);
1834 l += m;
1835 }
1836
1837 controlb(c, 1, buf, l, 1);
1838 }
1839 else
1840 control16(c, 1, result, 1);
1841
1842 control16(c, 9, t, 1); // assigned tunnel (our end)
1843 controladd(c, 0, t); // send the message
1844 }
1845 }
1846
1847 // read and process packet on tunnel (UDP)
1848 void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
1849 {
1850 uint8_t *chapresponse = NULL;
1851 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1852 uint8_t *p = buf + 2;
1853
1854
1855 CSTAT(processudp);
1856
1857 udp_rx += len;
1858 udp_rx_pkt++;
1859 LOG_HEX(5, "UDP Data", buf, len);
1860 STAT(tunnel_rx_packets);
1861 INC_STAT(tunnel_rx_bytes, len);
1862 if (len < 6)
1863 {
1864 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1865 STAT(tunnel_rx_errors);
1866 return;
1867 }
1868 if ((buf[1] & 0x0F) != 2)
1869 {
1870 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1871 STAT(tunnel_rx_errors);
1872 return;
1873 }
1874 if (*buf & 0x40)
1875 { // length
1876 l = ntohs(*(uint16_t *) p);
1877 p += 2;
1878 }
1879 t = ntohs(*(uint16_t *) p);
1880 p += 2;
1881 s = ntohs(*(uint16_t *) p);
1882 p += 2;
1883 if (s >= MAXSESSION)
1884 {
1885 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1886 STAT(tunnel_rx_errors);
1887 return;
1888 }
1889 if (t >= MAXTUNNEL)
1890 {
1891 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1892 STAT(tunnel_rx_errors);
1893 return;
1894 }
1895 if (*buf & 0x08)
1896 { // ns/nr
1897 ns = ntohs(*(uint16_t *) p);
1898 p += 2;
1899 nr = ntohs(*(uint16_t *) p);
1900 p += 2;
1901 }
1902 if (*buf & 0x02)
1903 { // offset
1904 uint16_t o = ntohs(*(uint16_t *) p);
1905 p += o + 2;
1906 }
1907 if ((p - buf) > l)
1908 {
1909 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1910 STAT(tunnel_rx_errors);
1911 return;
1912 }
1913 l -= (p - buf);
1914
1915 // used to time out old tunnels
1916 if (t && tunnel[t].state == TUNNELOPEN)
1917 tunnel[t].lastrec = time_now;
1918
1919 if (*buf & 0x80)
1920 { // control
1921 uint16_t message = 0xFFFF; // message type
1922 uint8_t fatal = 0;
1923 uint8_t mandatory = 0;
1924 uint16_t asession = 0; // assigned session
1925 uint32_t amagic = 0; // magic number
1926 uint8_t aflags = 0; // flags from last LCF
1927 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1928 char called[MAXTEL] = ""; // called number
1929 char calling[MAXTEL] = ""; // calling number
1930
1931 if (!config->cluster_iam_master)
1932 {
1933 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1934 return;
1935 }
1936
1937 // control messages must have bits 0x80|0x40|0x08
1938 // (type, length and sequence) set, and bits 0x02|0x01
1939 // (offset and priority) clear
1940 if ((*buf & 0xCB) != 0xC8)
1941 {
1942 LOG(1, s, t, "Bad control header %02X\n", *buf);
1943 STAT(tunnel_rx_errors);
1944 return;
1945 }
1946
1947 // check for duplicate tunnel open message
1948 if (!t && ns == 0)
1949 {
1950 int i;
1951
1952 //
1953 // Is this a duplicate of the first packet? (SCCRQ)
1954 //
1955 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1956 {
1957 if (tunnel[i].state != TUNNELOPENING ||
1958 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1959 tunnel[i].port != ntohs(addr->sin_port) )
1960 continue;
1961 t = i;
1962 LOG(3, s, t, "Duplicate SCCRQ?\n");
1963 break;
1964 }
1965 }
1966
1967 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1968 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1969
1970 // if no tunnel specified, assign one
1971 if (!t)
1972 {
1973 if (!(t = new_tunnel()))
1974 {
1975 LOG(1, 0, 0, "No more tunnels\n");
1976 STAT(tunnel_overflow);
1977 return;
1978 }
1979 tunnelclear(t);
1980 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1981 tunnel[t].port = ntohs(addr->sin_port);
1982 tunnel[t].window = 4; // default window
1983 STAT(tunnel_created);
1984 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1985 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1986 }
1987
1988 // If the 'ns' just received is not the 'nr' we're
1989 // expecting, just send an ack and drop it.
1990 //
1991 // if 'ns' is less, then we got a retransmitted packet.
1992 // if 'ns' is greater than missed a packet. Either way
1993 // we should ignore it.
1994 if (ns != tunnel[t].nr)
1995 {
1996 // is this the sequence we were expecting?
1997 STAT(tunnel_rx_errors);
1998 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
1999 t, ns, tunnel[t].nr);
2000
2001 if (l) // Is this not a ZLB?
2002 controlnull(t);
2003 return;
2004 }
2005
2006 // check sequence of this message
2007 {
2008 int skip = tunnel[t].window; // track how many in-window packets are still in queue
2009 // some to clear maybe?
2010 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
2011 {
2012 controlt *c = tunnel[t].controls;
2013 tunnel[t].controls = c->next;
2014 tunnel[t].controlc--;
2015 c->next = controlfree;
2016 controlfree = c;
2017 skip--;
2018 tunnel[t].try = 0; // we have progress
2019 }
2020
2021 // receiver advance (do here so quoted correctly in any sends below)
2022 if (l) tunnel[t].nr = (ns + 1);
2023 if (skip < 0) skip = 0;
2024 if (skip < tunnel[t].controlc)
2025 {
2026 // some control packets can now be sent that were previous stuck out of window
2027 int tosend = tunnel[t].window - skip;
2028 controlt *c = tunnel[t].controls;
2029 while (c && skip)
2030 {
2031 c = c->next;
2032 skip--;
2033 }
2034 while (c && tosend)
2035 {
2036 tunnel[t].try = 0; // first send
2037 tunnelsend(c->buf, c->length, t);
2038 c = c->next;
2039 tosend--;
2040 }
2041 }
2042 if (!tunnel[t].controlc)
2043 tunnel[t].retry = 0; // caught up
2044 }
2045 if (l)
2046 { // if not a null message
2047 int result = 0;
2048 int error = 0;
2049 char *msg = 0;
2050
2051 // process AVPs
2052 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
2053 {
2054 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
2055 uint8_t *b = p;
2056 uint8_t flags = *p;
2057 uint16_t mtype;
2058 if (n > l)
2059 {
2060 LOG(1, s, t, "Invalid length in AVP\n");
2061 STAT(tunnel_rx_errors);
2062 return;
2063 }
2064 p += n; // next
2065 l -= n;
2066 if (flags & 0x3C) // reserved bits, should be clear
2067 {
2068 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
2069 fatal = flags;
2070 result = 2; // general error
2071 error = 3; // reserved field non-zero
2072 msg = 0;
2073 continue; // next
2074 }
2075 b += 2;
2076 if (*(uint16_t *) (b))
2077 {
2078 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
2079 fatal = flags;
2080 result = 2; // general error
2081 error = 6; // generic vendor-specific error
2082 msg = "unsupported vendor-specific";
2083 continue; // next
2084 }
2085 b += 2;
2086 mtype = ntohs(*(uint16_t *) (b));
2087 b += 2;
2088 n -= 6;
2089
2090 if (flags & 0x40)
2091 {
2092 uint16_t orig_len;
2093
2094 // handle hidden AVPs
2095 if (!*config->l2tp_secret)
2096 {
2097 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
2098 fatal = flags;
2099 result = 2; // general error
2100 error = 6; // generic vendor-specific error
2101 msg = "secret not specified";
2102 continue;
2103 }
2104 if (!session[s].random_vector_length)
2105 {
2106 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
2107 fatal = flags;
2108 result = 2; // general error
2109 error = 6; // generic
2110 msg = "no random vector";
2111 continue;
2112 }
2113 if (n < 8)
2114 {
2115 LOG(2, s, t, "Short hidden AVP.\n");
2116 fatal = flags;
2117 result = 2; // general error
2118 error = 2; // length is wrong
2119 msg = 0;
2120 continue;
2121 }
2122
2123 // Unhide the AVP
2124 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
2125
2126 orig_len = ntohs(*(uint16_t *) b);
2127 if (orig_len > n + 2)
2128 {
2129 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
2130 orig_len, n);
2131
2132 fatal = flags;
2133 result = 2; // general error
2134 error = 2; // length is wrong
2135 msg = 0;
2136 continue;
2137 }
2138
2139 b += 2;
2140 n = orig_len;
2141 }
2142
2143 LOG(4, s, t, " AVP %d (%s) len %d%s%s\n", mtype, l2tp_avp_name(mtype), n,
2144 flags & 0x40 ? ", hidden" : "", flags & 0x80 ? ", mandatory" : "");
2145
2146 switch (mtype)
2147 {
2148 case 0: // message type
2149 message = ntohs(*(uint16_t *) b);
2150 mandatory = flags & 0x80;
2151 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_code(message));
2152 break;
2153 case 1: // result code
2154 {
2155 uint16_t rescode = ntohs(*(uint16_t *) b);
2156 const char* resdesc = "(unknown)";
2157 if (message == 4)
2158 { /* StopCCN */
2159 resdesc = l2tp_stopccn_result_code(rescode);
2160 }
2161 else if (message == 14)
2162 { /* CDN */
2163 resdesc = l2tp_cdn_result_code(rescode);
2164 }
2165
2166 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2167 if (n >= 4)
2168 {
2169 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2170 LOG(4, s, t, " Error Code %d: %s\n", errcode, l2tp_error_code(errcode));
2171 }
2172 if (n > 4)
2173 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2174
2175 break;
2176 }
2177 break;
2178 case 2: // protocol version
2179 {
2180 version = ntohs(*(uint16_t *) (b));
2181 LOG(4, s, t, " Protocol version = %d\n", version);
2182 if (version && version != 0x0100)
2183 { // allow 0.0 and 1.0
2184 LOG(1, s, t, " Bad protocol version %04X\n", version);
2185 fatal = flags;
2186 result = 5; // unspported protocol version
2187 error = 0x0100; // supported version
2188 msg = 0;
2189 continue; // next
2190 }
2191 }
2192 break;
2193 case 3: // framing capabilities
2194 // LOG(4, s, t, "Framing capabilities\n");
2195 break;
2196 case 4: // bearer capabilities
2197 // LOG(4, s, t, "Bearer capabilities\n");
2198 break;
2199 case 5: // tie breaker
2200 // We never open tunnels, so we don't care about tie breakers
2201 // LOG(4, s, t, "Tie breaker\n");
2202 continue;
2203 case 6: // firmware revision
2204 // LOG(4, s, t, "Firmware revision\n");
2205 break;
2206 case 7: // host name
2207 memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
2208 memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
2209 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2210 // TBA - to send to RADIUS
2211 break;
2212 case 8: // vendor name
2213 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2214 memcpy(tunnel[t].vendor, b, (n < sizeof(tunnel[t].vendor)) ? n : sizeof(tunnel[t].vendor) - 1);
2215 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2216 break;
2217 case 9: // assigned tunnel
2218 tunnel[t].far = ntohs(*(uint16_t *) (b));
2219 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2220 break;
2221 case 10: // rx window
2222 tunnel[t].window = ntohs(*(uint16_t *) (b));
2223 if (!tunnel[t].window)
2224 tunnel[t].window = 1; // window of 0 is silly
2225 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2226 break;
2227 case 11: // Challenge
2228 {
2229 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2230 build_chap_response(b, 2, n, &chapresponse);
2231 }
2232 break;
2233 case 13: // Response
2234 // Why did they send a response? We never challenge.
2235 LOG(2, s, t, " received unexpected challenge response\n");
2236 break;
2237
2238 case 14: // assigned session
2239 asession = session[s].far = ntohs(*(uint16_t *) (b));
2240 LOG(4, s, t, " assigned session = %d\n", asession);
2241 break;
2242 case 15: // call serial number
2243 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2244 break;
2245 case 18: // bearer type
2246 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2247 // TBA - for RADIUS
2248 break;
2249 case 19: // framing type
2250 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2251 // TBA
2252 break;
2253 case 21: // called number
2254 memset(called, 0, sizeof(called));
2255 memcpy(called, b, (n < sizeof(called)) ? n : sizeof(called) - 1);
2256 LOG(4, s, t, " Called <%s>\n", called);
2257 break;
2258 case 22: // calling number
2259 memset(calling, 0, sizeof(calling));
2260 memcpy(calling, b, (n < sizeof(calling)) ? n : sizeof(calling) - 1);
2261 LOG(4, s, t, " Calling <%s>\n", calling);
2262 break;
2263 case 23: // subtype
2264 break;
2265 case 24: // tx connect speed
2266 if (n == 4)
2267 {
2268 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2269 }
2270 else
2271 {
2272 // AS5300s send connect speed as a string
2273 char tmp[30];
2274 memset(tmp, 0, sizeof(tmp));
2275 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2276 session[s].tx_connect_speed = atol(tmp);
2277 }
2278 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2279 break;
2280 case 38: // rx connect speed
2281 if (n == 4)
2282 {
2283 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2284 }
2285 else
2286 {
2287 // AS5300s send connect speed as a string
2288 char tmp[30];
2289 memset(tmp, 0, sizeof(tmp));
2290 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2291 session[s].rx_connect_speed = atol(tmp);
2292 }
2293 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2294 break;
2295 case 25: // Physical Channel ID
2296 {
2297 uint32_t tmp = ntohl(*(uint32_t *) b);
2298 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2299 break;
2300 }
2301 case 29: // Proxy Authentication Type
2302 {
2303 uint16_t atype = ntohs(*(uint16_t *)b);
2304 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, ppp_auth_type(atype));
2305 break;
2306 }
2307 case 30: // Proxy Authentication Name
2308 {
2309 char authname[64];
2310 memset(authname, 0, sizeof(authname));
2311 memcpy(authname, b, (n < sizeof(authname)) ? n : sizeof(authname) - 1);
2312 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2313 authname);
2314 break;
2315 }
2316 case 31: // Proxy Authentication Challenge
2317 {
2318 LOG(4, s, t, " Proxy Auth Challenge\n");
2319 break;
2320 }
2321 case 32: // Proxy Authentication ID
2322 {
2323 uint16_t authid = ntohs(*(uint16_t *)(b));
2324 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2325 break;
2326 }
2327 case 33: // Proxy Authentication Response
2328 LOG(4, s, t, " Proxy Auth Response\n");
2329 break;
2330 case 27: // last sent lcp
2331 { // find magic number
2332 uint8_t *p = b, *e = p + n;
2333 while (p + 1 < e && p[1] && p + p[1] <= e)
2334 {
2335 if (*p == 5 && p[1] == 6) // Magic-Number
2336 amagic = ntohl(*(uint32_t *) (p + 2));
2337 else if (*p == 7) // Protocol-Field-Compression
2338 aflags |= SESSION_PFC;
2339 else if (*p == 8) // Address-and-Control-Field-Compression
2340 aflags |= SESSION_ACFC;
2341 p += p[1];
2342 }
2343 }
2344 break;
2345 case 28: // last recv lcp confreq
2346 break;
2347 case 26: // Initial Received LCP CONFREQ
2348 break;
2349 case 39: // seq required - we control it as an LNS anyway...
2350 break;
2351 case 36: // Random Vector
2352 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2353 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2354 if (n > sizeof(session[s].random_vector))
2355 n = sizeof(session[s].random_vector);
2356 memcpy(session[s].random_vector, b, n);
2357 session[s].random_vector_length = n;
2358 break;
2359 default:
2360 {
2361 static char e[] = "unknown AVP 0xXXXX";
2362 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2363 fatal = flags;
2364 result = 2; // general error
2365 error = 8; // unknown mandatory AVP
2366 sprintf((msg = e) + 14, "%04x", mtype);
2367 continue; // next
2368 }
2369 }
2370 }
2371 // process message
2372 if (fatal & 0x80)
2373 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2374 else
2375 switch (message)
2376 {
2377 case 1: // SCCRQ - Start Control Connection Request
2378 tunnel[t].state = TUNNELOPENING;
2379 if (main_quit != QUIT_SHUTDOWN)
2380 {
2381 controlt *c = controlnew(2); // sending SCCRP
2382 control16(c, 2, version, 1); // protocol version
2383 control32(c, 3, 3, 1); // framing
2384 controls(c, 7, hostname, 1); // host name
2385 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2386 control16(c, 9, t, 1); // assigned tunnel
2387 controladd(c, 0, t); // send the resply
2388 }
2389 else
2390 {
2391 tunnelshutdown(t, "Shutting down", 6, 0, 0);
2392 }
2393 break;
2394 case 2: // SCCRP
2395 tunnel[t].state = TUNNELOPEN;
2396 break;
2397 case 3: // SCCN
2398 tunnel[t].state = TUNNELOPEN;
2399 controlnull(t); // ack
2400 break;
2401 case 4: // StopCCN
2402 controlnull(t); // ack
2403 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2404 break;
2405 case 6: // HELLO
2406 controlnull(t); // simply ACK
2407 break;
2408 case 7: // OCRQ
2409 // TBA
2410 break;
2411 case 8: // OCRO
2412 // TBA
2413 break;
2414 case 9: // OCCN
2415 // TBA
2416 break;
2417 case 10: // ICRQ
2418 if (sessionfree && main_quit != QUIT_SHUTDOWN)
2419 {
2420 controlt *c = controlnew(11); // ICRP
2421
2422 s = sessionfree;
2423 sessionfree = session[s].next;
2424 memset(&session[s], 0, sizeof(session[s]));
2425
2426 if (s > config->cluster_highest_sessionid)
2427 config->cluster_highest_sessionid = s;
2428
2429 session[s].opened = time_now;
2430 session[s].tunnel = t;
2431 session[s].far = asession;
2432 session[s].last_packet = time_now;
2433 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2434 control16(c, 14, s, 1); // assigned session
2435 controladd(c, asession, t); // send the reply
2436
2437 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2438 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2439
2440 session[s].ppp.phase = Establish;
2441 session[s].ppp.lcp = Starting;
2442
2443 STAT(session_created);
2444 break;
2445 }
2446
2447 {
2448 controlt *c = controlnew(14); // CDN
2449 if (!sessionfree)
2450 {
2451 STAT(session_overflow);
2452 LOG(1, 0, t, "No free sessions\n");
2453 control16(c, 1, 4, 0); // temporary lack of resources
2454 }
2455 else
2456 control16(c, 1, 2, 7); // shutting down, try another
2457
2458 controladd(c, asession, t); // send the message
2459 }
2460 return;
2461 case 11: // ICRP
2462 // TBA
2463 break;
2464 case 12: // ICCN
2465 if (amagic == 0) amagic = time_now;
2466 session[s].magic = amagic; // set magic number
2467 session[s].flags = aflags; // set flags received
2468 session[s].mru = PPPoE_MRU; // default
2469 controlnull(t); // ack
2470
2471 // start LCP
2472 sess_local[s].lcp_authtype = config->radius_authprefer;
2473 sess_local[s].ppp_mru = MRU;
2474 sendlcp(s, t);
2475 change_state(s, lcp, RequestSent);
2476 break;
2477
2478 case 14: // CDN
2479 controlnull(t); // ack
2480 sessionshutdown(s, "Closed (Received CDN).", 0, 0);
2481 break;
2482 case 0xFFFF:
2483 LOG(1, s, t, "Missing message type\n");
2484 break;
2485 default:
2486 STAT(tunnel_rx_errors);
2487 if (mandatory)
2488 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2489 else
2490 LOG(1, s, t, "Unknown message type %d\n", message);
2491 break;
2492 }
2493 if (chapresponse) free(chapresponse);
2494 cluster_send_tunnel(t);
2495 }
2496 else
2497 {
2498 LOG(4, s, t, " Got a ZLB ack\n");
2499 }
2500 }
2501 else
2502 { // data
2503 uint16_t proto;
2504
2505 LOG_HEX(5, "Receive Tunnel Data", p, l);
2506 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2507 { // HDLC address header, discard
2508 p += 2;
2509 l -= 2;
2510 }
2511 if (l < 2)
2512 {
2513 LOG(1, s, t, "Short ppp length %d\n", l);
2514 STAT(tunnel_rx_errors);
2515 return;
2516 }
2517 if (*p & 1)
2518 {
2519 proto = *p++;
2520 l--;
2521 }
2522 else
2523 {
2524 proto = ntohs(*(uint16_t *) p);
2525 p += 2;
2526 l -= 2;
2527 }
2528
2529 if (s && !session[s].opened) // Is something wrong??
2530 {
2531 if (!config->cluster_iam_master)
2532 {
2533 // Pass it off to the master to deal with..
2534 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2535 return;
2536 }
2537
2538
2539 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2540 STAT(tunnel_rx_errors);
2541 return;
2542 }
2543
2544 if (proto == PPPPAP)
2545 {
2546 session[s].last_packet = time_now;
2547 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2548 processpap(s, t, p, l);
2549 }
2550 else if (proto == PPPCHAP)
2551 {
2552 session[s].last_packet = time_now;
2553 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2554 processchap(s, t, p, l);
2555 }
2556 else if (proto == PPPLCP)
2557 {
2558 session[s].last_packet = time_now;
2559 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2560 processlcp(s, t, p, l);
2561 }
2562 else if (proto == PPPIPCP)
2563 {
2564 session[s].last_packet = time_now;
2565 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2566 processipcp(s, t, p, l);
2567 }
2568 else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[0])
2569 {
2570 session[s].last_packet = time_now;
2571 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2572 processipv6cp(s, t, p, l);
2573 }
2574 else if (proto == PPPCCP)
2575 {
2576 session[s].last_packet = time_now;
2577 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2578 processccp(s, t, p, l);
2579 }
2580 else if (proto == PPPIP)
2581 {
2582 if (session[s].die)
2583 {
2584 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2585 return; // closing session, PPP not processed
2586 }
2587
2588 session[s].last_packet = time_now;
2589 if (session[s].walled_garden && !config->cluster_iam_master)
2590 {
2591 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2592 return;
2593 }
2594
2595 processipin(s, t, p, l);
2596 }
2597 else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
2598 {
2599 if (session[s].die)
2600 {
2601 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2602 return; // closing session, PPP not processed
2603 }
2604
2605 session[s].last_packet = time_now;
2606 if (session[s].walled_garden && !config->cluster_iam_master)
2607 {
2608 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2609 return;
2610 }
2611
2612 processipv6in(s, t, p, l);
2613 }
2614 else if (session[s].ppp.lcp == Opened)
2615 {
2616 session[s].last_packet = time_now;
2617 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2618 protoreject(s, t, p, l, proto);
2619 }
2620 else
2621 {
2622 LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
2623 proto, ppp_state(session[s].ppp.lcp));
2624 }
2625 }
2626 }
2627
2628 // read and process packet on tun
2629 static void processtun(uint8_t * buf, int len)
2630 {
2631 LOG_HEX(5, "Receive TUN Data", buf, len);
2632 STAT(tun_rx_packets);
2633 INC_STAT(tun_rx_bytes, len);
2634
2635 CSTAT(processtun);
2636
2637 eth_rx_pkt++;
2638 eth_rx += len;
2639 if (len < 22)
2640 {
2641 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2642 STAT(tun_rx_errors);
2643 return;
2644 }
2645
2646 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2647 processipout(buf, len);
2648 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2649 && config->ipv6_prefix.s6_addr[0])
2650 processipv6out(buf, len);
2651
2652 // Else discard.
2653 }
2654
2655 // Handle retries, timeouts. Runs every 1/10th sec, want to ensure
2656 // that we look at the whole of the tunnel, radius and session tables
2657 // every second
2658 static void regular_cleanups(double period)
2659 {
2660 // Next tunnel, radius and session to check for actions on.
2661 static tunnelidt t = 0;
2662 static int r = 0;
2663 static sessionidt s = 0;
2664
2665 int t_actions = 0;
2666 int r_actions = 0;
2667 int s_actions = 0;
2668
2669 int t_slice;
2670 int r_slice;
2671 int s_slice;
2672
2673 int i;
2674 int a;
2675
2676 // divide up tables into slices based on the last run
2677 t_slice = config->cluster_highest_tunnelid * period;
2678 r_slice = (MAXRADIUS - 1) * period;
2679 s_slice = config->cluster_highest_sessionid * period;
2680
2681 if (t_slice < 1)
2682 t_slice = 1;
2683 else if (t_slice > config->cluster_highest_tunnelid)
2684 t_slice = config->cluster_highest_tunnelid;
2685
2686 if (r_slice < 1)
2687 r_slice = 1;
2688 else if (r_slice > (MAXRADIUS - 1))
2689 r_slice = MAXRADIUS - 1;
2690
2691 if (s_slice < 1)
2692 s_slice = 1;
2693 else if (s_slice > config->cluster_highest_sessionid)
2694 s_slice = config->cluster_highest_sessionid;
2695
2696 LOG(4, 0, 0, "Begin regular cleanup (last %f seconds ago)\n", period);
2697
2698 for (i = 0; i < t_slice; i++)
2699 {
2700 t++;
2701 if (t > config->cluster_highest_tunnelid)
2702 t = 1;
2703
2704 // check for expired tunnels
2705 if (tunnel[t].die && tunnel[t].die <= TIME)
2706 {
2707 STAT(tunnel_timeout);
2708 tunnelkill(t, "Expired");
2709 t_actions++;
2710 continue;
2711 }
2712 // check for message resend
2713 if (tunnel[t].retry && tunnel[t].controlc)
2714 {
2715 // resend pending messages as timeout on reply
2716 if (tunnel[t].retry <= TIME)
2717 {
2718 controlt *c = tunnel[t].controls;
2719 uint8_t w = tunnel[t].window;
2720 tunnel[t].try++; // another try
2721 if (tunnel[t].try > 5)
2722 tunnelkill(t, "Timeout on control message"); // game over
2723 else
2724 while (c && w--)
2725 {
2726 tunnelsend(c->buf, c->length, t);
2727 c = c->next;
2728 }
2729
2730 t_actions++;
2731 }
2732 }
2733 // Send hello
2734 if (tunnel[t].state == TUNNELOPEN && !tunnel[t].controlc && (time_now - tunnel[t].lastrec) > 60)
2735 {
2736 controlt *c = controlnew(6); // sending HELLO
2737 controladd(c, 0, t); // send the message
2738 LOG(3, 0, t, "Sending HELLO message\n");
2739 t_actions++;
2740 }
2741
2742 // Check for tunnel changes requested from the CLI
2743 if ((a = cli_tunnel_actions[t].action))
2744 {
2745 cli_tunnel_actions[t].action = 0;
2746 if (a & CLI_TUN_KILL)
2747 {
2748 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2749 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2750 t_actions++;
2751 }
2752 }
2753 }
2754
2755 for (i = 0; i < r_slice; i++)
2756 {
2757 r++;
2758 if (r >= MAXRADIUS)
2759 r = 1;
2760
2761 if (!radius[r].state)
2762 continue;
2763
2764 if (radius[r].retry <= TIME)
2765 {
2766 radiusretry(r);
2767 r_actions++;
2768 }
2769 }
2770
2771 for (i = 0; i < s_slice; i++)
2772 {
2773 s++;
2774 if (s > config->cluster_highest_sessionid)
2775 s = 1;
2776
2777 if (!session[s].opened) // Session isn't in use
2778 continue;
2779
2780 // check for expired sessions
2781 if (session[s].die)
2782 {
2783 if (session[s].die <= TIME)
2784 {
2785 sessionkill(s, "Expired");
2786 s_actions++;
2787 }
2788 continue;
2789 }
2790
2791 // PPP timeouts
2792 if (sess_local[s].lcp.restart <= time_now)
2793 {
2794 int next_state = session[s].ppp.lcp;
2795 switch (session[s].ppp.lcp)
2796 {
2797 case RequestSent:
2798 case AckReceived:
2799 next_state = RequestSent;
2800
2801 case AckSent:
2802 if (sess_local[s].lcp.conf_sent < config->ppp_max_configure)
2803 {
2804 LOG(3, s, session[s].tunnel, "No ACK for LCP ConfigReq... resending\n");
2805 sendlcp(s, session[s].tunnel);
2806 change_state(s, lcp, next_state);
2807 }
2808 else
2809 {
2810 sessionshutdown(s, "No response to LCP ConfigReq.", 3, 0);
2811 STAT(session_timeout);
2812 }
2813
2814 s_actions++;
2815 }
2816
2817 if (session[s].die)
2818 continue;
2819 }
2820
2821 if (sess_local[s].ipcp.restart <= time_now)
2822 {
2823 int next_state = session[s].ppp.ipcp;
2824 switch (session[s].ppp.ipcp)
2825 {
2826 case RequestSent:
2827 case AckReceived:
2828 next_state = RequestSent;
2829
2830 case AckSent:
2831 if (sess_local[s].ipcp.conf_sent < config->ppp_max_configure)
2832 {
2833 LOG(3, s, session[s].tunnel, "No ACK for IPCP ConfigReq... resending\n");
2834 sendipcp(s, session[s].tunnel);
2835 change_state(s, ipcp, next_state);
2836 }
2837 else
2838 {
2839 sessionshutdown(s, "No response to IPCP ConfigReq.", 3, 0);
2840 STAT(session_timeout);
2841 }
2842
2843 s_actions++;
2844 }
2845
2846 if (session[s].die)
2847 continue;
2848 }
2849
2850 if (sess_local[s].ipv6cp.restart <= time_now)
2851 {
2852 int next_state = session[s].ppp.ipv6cp;
2853 switch (session[s].ppp.ipv6cp)
2854 {
2855 case RequestSent:
2856 case AckReceived:
2857 next_state = RequestSent;
2858
2859 case AckSent:
2860 if (sess_local[s].ipv6cp.conf_sent < config->ppp_max_configure)
2861 {
2862 LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq... resending\n");
2863 sendipv6cp(s, session[s].tunnel);
2864 change_state(s, ipv6cp, next_state);
2865 }
2866 else
2867 {
2868 LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq\n");
2869 change_state(s, ipv6cp, Stopped);
2870 }
2871
2872 s_actions++;
2873 }
2874 }
2875
2876 if (sess_local[s].ccp.restart <= time_now)
2877 {
2878 int next_state = session[s].ppp.ccp;
2879 switch (session[s].ppp.ccp)
2880 {
2881 case RequestSent:
2882 case AckReceived:
2883 next_state = RequestSent;
2884
2885 case AckSent:
2886 if (sess_local[s].ccp.conf_sent < config->ppp_max_configure)
2887 {
2888 LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq... resending\n");
2889 sendccp(s, session[s].tunnel);
2890 change_state(s, ccp, next_state);
2891 }
2892 else
2893 {
2894 LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq\n");
2895 change_state(s, ccp, Stopped);
2896 }
2897
2898 s_actions++;
2899 }
2900 }
2901
2902 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2903 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2904 {
2905 sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
2906 STAT(session_timeout);
2907 s_actions++;
2908 continue;
2909 }
2910
2911 // No data in ECHO_TIMEOUT seconds, send LCP ECHO
2912 if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT) &&
2913 (time_now - sess_local[s].last_echo >= ECHO_TIMEOUT))
2914 {
2915 uint8_t b[MAXETHER];
2916
2917 uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP);
2918 if (!q) continue;
2919
2920 *q = EchoReq;
2921 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2922 *(uint16_t *)(q + 2) = htons(8); // Length
2923 *(uint32_t *)(q + 4) = session[s].ppp.lcp == Opened ? htonl(session[s].magic) : 0; // Magic Number
2924
2925 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2926 (int)(time_now - session[s].last_packet));
2927 tunnelsend(b, 24, session[s].tunnel); // send it
2928 sess_local[s].last_echo = time_now;
2929 s_actions++;
2930 }
2931
2932 // Check for actions requested from the CLI
2933 if ((a = cli_session_actions[s].action))
2934 {
2935 int send = 0;
2936
2937 cli_session_actions[s].action = 0;
2938 if (a & CLI_SESS_KILL)
2939 {
2940 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2941 sessionshutdown(s, "Requested by administrator.", 3, 0);
2942 a = 0; // dead, no need to check for other actions
2943 s_actions++;
2944 }
2945
2946 if (a & CLI_SESS_NOSNOOP)
2947 {
2948 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2949 session[s].snoop_ip = 0;
2950 session[s].snoop_port = 0;
2951 s_actions++;
2952 send++;
2953 }
2954 else if (a & CLI_SESS_SNOOP)
2955 {
2956 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2957 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2958 cli_session_actions[s].snoop_port);
2959
2960 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2961 session[s].snoop_port = cli_session_actions[s].snoop_port;
2962 s_actions++;
2963 send++;
2964 }
2965
2966 if (a & CLI_SESS_NOTHROTTLE)
2967 {
2968 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2969 throttle_session(s, 0, 0);
2970 s_actions++;
2971 send++;
2972 }
2973 else if (a & CLI_SESS_THROTTLE)
2974 {
2975 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2976 cli_session_actions[s].throttle_in,
2977 cli_session_actions[s].throttle_out);
2978
2979 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
2980 s_actions++;
2981 send++;
2982 }
2983
2984 if (a & CLI_SESS_NOFILTER)
2985 {
2986 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
2987 filter_session(s, 0, 0);
2988 s_actions++;
2989 send++;
2990 }
2991 else if (a & CLI_SESS_FILTER)
2992 {
2993 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
2994 cli_session_actions[s].filter_in,
2995 cli_session_actions[s].filter_out);
2996
2997 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
2998 s_actions++;
2999 send++;
3000 }
3001
3002 if (send)
3003 cluster_send_session(s);
3004 }
3005
3006 // RADIUS interim accounting
3007 if (config->radius_accounting && config->radius_interim > 0
3008 && session[s].ip && !session[s].walled_garden
3009 && !sess_local[s].radius // RADIUS already in progress
3010 && time_now - sess_local[s].last_interim >= config->radius_interim)
3011 {
3012 int rad = radiusnew(s);
3013 if (!rad)
3014 {
3015 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
3016 STAT(radius_overflow);
3017 continue;
3018 }
3019
3020 LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
3021 session[s].user, session[s].unique_id);
3022
3023 radiussend(rad, RADIUSINTERIM);
3024 sess_local[s].last_interim = time_now;
3025 s_actions++;
3026 }
3027 }
3028
3029 LOG(4, 0, 0, "End regular cleanup: checked %d/%d/%d tunnels/radius/sessions; %d/%d/%d actions\n",
3030 t_slice, r_slice, s_slice, t_actions, r_actions, s_actions);
3031 }
3032
3033 //
3034 // Are we in the middle of a tunnel update, or radius
3035 // requests??
3036 //
3037 static int still_busy(void)
3038 {
3039 int i;
3040 static clockt last_talked = 0;
3041 static clockt start_busy_wait = 0;
3042
3043 if (!config->cluster_iam_master)
3044 {
3045 #ifdef BGP
3046 static time_t stopped_bgp = 0;
3047 if (bgp_configured)
3048 {
3049 if (!stopped_bgp)
3050 {
3051 LOG(1, 0, 0, "Shutting down in %d seconds, stopping BGP...\n", QUIT_DELAY);
3052
3053 for (i = 0; i < BGP_NUM_PEERS; i++)
3054 if (bgp_peers[i].state == Established)
3055 bgp_stop(&bgp_peers[i]);
3056
3057 stopped_bgp = time_now;
3058
3059 // we don't want to become master
3060 cluster_send_ping(0);
3061
3062 return 1;
3063 }
3064
3065 if (time_now < (stopped_bgp + QUIT_DELAY))
3066 return 1;
3067 }
3068 #endif /* BGP */
3069
3070 return 0;
3071 }
3072
3073 if (main_quit == QUIT_SHUTDOWN)
3074 {
3075 static int dropped = 0;
3076 if (!dropped)
3077 {
3078 int i;
3079
3080 LOG(1, 0, 0, "Dropping sessions and tunnels\n");
3081 for (i = 1; i < MAXTUNNEL; i++)
3082 if (tunnel[i].ip || tunnel[i].state)
3083 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3084
3085 dropped = 1;
3086 }
3087 }
3088
3089 if (start_busy_wait == 0)
3090 start_busy_wait = TIME;
3091
3092 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
3093 {
3094 if (!tunnel[i].controlc)
3095 continue;
3096
3097 if (last_talked != TIME)
3098 {
3099 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
3100 last_talked = TIME;
3101 }
3102 return 1;
3103 }
3104
3105 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
3106 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
3107 {
3108 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
3109 return 0;
3110 }
3111
3112 for (i = 1; i < MAXRADIUS; i++)
3113 {
3114 if (radius[i].state == RADIUSNULL)
3115 continue;
3116 if (radius[i].state == RADIUSWAIT)
3117 continue;
3118
3119 if (last_talked != TIME)
3120 {
3121 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
3122 last_talked = TIME;
3123 }
3124 return 1;
3125 }
3126
3127 return 0;
3128 }
3129
3130 #ifdef HAVE_EPOLL
3131 # include <sys/epoll.h>
3132 #else
3133 # define FAKE_EPOLL_IMPLEMENTATION /* include the functions */
3134 # include "fake_epoll.h"
3135 #endif
3136
3137 // the base set of fds polled: cli, cluster, tun, udp, control, dae
3138 #define BASE_FDS 6
3139
3140 // additional polled fds
3141 #ifdef BGP
3142 # define EXTRA_FDS BGP_NUM_PEERS
3143 #else
3144 # define EXTRA_FDS 0
3145 #endif
3146
3147 // main loop - gets packets on tun or udp and processes them
3148 static void mainloop(void)
3149 {
3150 int i;
3151 uint8_t buf[65536];
3152 clockt next_cluster_ping = 0; // send initial ping immediately
3153 struct epoll_event events[BASE_FDS + RADIUS_FDS + EXTRA_FDS];
3154 int maxevent = sizeof(events)/sizeof(*events);
3155
3156 if ((epollfd = epoll_create(maxevent)) < 0)
3157 {
3158 LOG(0, 0, 0, "epoll_create failed: %s\n", strerror(errno));
3159 exit(1);
3160 }
3161
3162 LOG(4, 0, 0, "Beginning of main loop. clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d\n",
3163 clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd);
3164
3165 /* setup our fds to poll for input */
3166 {
3167 static struct event_data d[BASE_FDS];
3168 struct epoll_event e;
3169
3170 e.events = EPOLLIN;
3171 i = 0;
3172
3173 d[i].type = FD_TYPE_CLI;
3174 e.data.ptr = &d[i++];
3175 epoll_ctl(epollfd, EPOLL_CTL_ADD, clifd, &e);
3176
3177 d[i].type = FD_TYPE_CLUSTER;
3178 e.data.ptr = &d[i++];
3179 epoll_ctl(epollfd, EPOLL_CTL_ADD, cluster_sockfd, &e);
3180
3181 d[i].type = FD_TYPE_TUN;
3182 e.data.ptr = &d[i++];
3183 epoll_ctl(epollfd, EPOLL_CTL_ADD, tunfd, &e);
3184
3185 d[i].type = FD_TYPE_UDP;
3186 e.data.ptr = &d[i++];
3187 epoll_ctl(epollfd, EPOLL_CTL_ADD, udpfd, &e);
3188
3189 d[i].type = FD_TYPE_CONTROL;
3190 e.data.ptr = &d[i++];
3191 epoll_ctl(epollfd, EPOLL_CTL_ADD, controlfd, &e);
3192
3193 d[i].type = FD_TYPE_DAE;
3194 e.data.ptr = &d[i++];
3195 epoll_ctl(epollfd, EPOLL_CTL_ADD, daefd, &e);
3196 }
3197
3198 #ifdef BGP
3199 signal(SIGPIPE, SIG_IGN);
3200 bgp_setup(config->as_number);
3201 if (config->bind_address)
3202 bgp_add_route(config->bind_address, 0xffffffff);
3203
3204 for (i = 0; i < BGP_NUM_PEERS; i++)
3205 {
3206 if (config->neighbour[i].name[0])
3207 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3208 config->neighbour[i].as, config->neighbour[i].keepalive,
3209 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3210 }
3211 #endif /* BGP */
3212
3213 while (!main_quit || still_busy())
3214 {
3215 int more = 0;
3216 int n;
3217
3218
3219 if (main_reload)
3220 {
3221 main_reload = 0;
3222 read_config_file();
3223 config->reload_config++;
3224 }
3225
3226 if (config->reload_config)
3227 {
3228 config->reload_config = 0;
3229 update_config();
3230 }
3231
3232 #ifdef BGP
3233 bgp_set_poll();
3234 #endif /* BGP */
3235
3236 n = epoll_wait(epollfd, events, maxevent, 100); // timeout 100ms (1/10th sec)
3237 STAT(select_called);
3238
3239 TIME = now(NULL);
3240 if (n < 0)
3241 {
3242 if (errno == EINTR ||
3243 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
3244 continue;
3245
3246 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
3247 break; // exit
3248 }
3249
3250 if (n)
3251 {
3252 struct sockaddr_in addr;
3253 struct in_addr local;
3254 socklen_t alen;
3255 int c, s;
3256 int udp_ready = 0;
3257 int tun_ready = 0;
3258 int cluster_ready = 0;
3259 int udp_pkts = 0;
3260 int tun_pkts = 0;
3261 int cluster_pkts = 0;
3262 #ifdef BGP
3263 uint32_t bgp_events[BGP_NUM_PEERS];
3264 memset(bgp_events, 0, sizeof(bgp_events));
3265 #endif /* BGP */
3266
3267 for (c = n, i = 0; i < c; i++)
3268 {
3269 struct event_data *d = events[i].data.ptr;
3270
3271 switch (d->type)
3272 {
3273 case FD_TYPE_CLI: // CLI connections
3274 {
3275 int cli;
3276
3277 alen = sizeof(addr);
3278 if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
3279 {
3280 cli_do(cli);
3281 close(cli);
3282 }
3283 else
3284 LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
3285
3286 n--;
3287 break;
3288 }
3289
3290 // these are handled below, with multiple interleaved reads
3291 case FD_TYPE_CLUSTER: cluster_ready++; break;
3292 case FD_TYPE_TUN: tun_ready++; break;
3293 case FD_TYPE_UDP: udp_ready++; break;
3294
3295 case FD_TYPE_CONTROL: // nsctl commands
3296 alen = sizeof(addr);
3297 s = recvfromto(controlfd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen, &local);
3298 if (s > 0) processcontrol(buf, s, &addr, alen, &local);
3299 n--;
3300 break;
3301
3302 case FD_TYPE_DAE: // DAE requests
3303 alen = sizeof(addr);
3304 s = recvfromto(daefd, buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen, &local);
3305 if (s > 0) processdae(buf, s, &addr, alen, &local);
3306 n--;
3307 break;
3308
3309 case FD_TYPE_RADIUS: // RADIUS response
3310 alen = sizeof(addr);
3311 s = recvfrom(radfds[d->index], buf, sizeof(buf), MSG_WAITALL, (struct sockaddr *) &addr, &alen);
3312 if (s >= 0 && config->cluster_iam_master)
3313 {
3314 if (addr.sin_addr.s_addr == config->radiusserver[0] ||
3315 addr.sin_addr.s_addr == config->radiusserver[1])
3316 processrad(buf, s, d->index);
3317 else
3318 LOG(3, 0, 0, "Dropping RADIUS packet from unknown source %s\n",
3319 fmtaddr(addr.sin_addr.s_addr, 0));
3320 }
3321
3322 n--;
3323 break;
3324
3325 #ifdef BGP
3326 case FD_TYPE_BGP:
3327 bgp_events[d->index] = events[i].events;
3328 n--;
3329 break;
3330 #endif /* BGP */
3331
3332 default:
3333 LOG(0, 0, 0, "Unexpected fd type returned from epoll_wait: %d\n", d->type);
3334 }
3335 }
3336
3337 #ifdef BGP
3338 bgp_process(bgp_events);
3339 #endif /* BGP */
3340
3341 for (c = 0; n && c < config->multi_read_count; c++)
3342 {
3343 // L2TP
3344 if (udp_ready)
3345 {
3346 alen = sizeof(addr);
3347 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
3348 {
3349 processudp(buf, s, &addr);
3350 udp_pkts++;
3351 }
3352 else
3353 {
3354 udp_ready = 0;
3355 n--;
3356 }
3357 }
3358
3359 // incoming IP
3360 if (tun_ready)
3361 {
3362 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
3363 {
3364 processtun(buf, s);
3365 tun_pkts++;
3366 }
3367 else
3368 {
3369 tun_ready = 0;
3370 n--;
3371 }
3372 }
3373
3374 // cluster
3375 if (cluster_ready)
3376 {
3377 alen = sizeof(addr);
3378 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
3379 {
3380 processcluster(buf, s, addr.sin_addr.s_addr);
3381 cluster_pkts++;
3382 }
3383 else
3384 {
3385 cluster_ready = 0;
3386 n--;
3387 }
3388 }
3389 }
3390
3391 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
3392 STAT(multi_read_used);
3393
3394 if (c >= config->multi_read_count)
3395 {
3396 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
3397 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3398
3399 STAT(multi_read_exceeded);
3400 more++;
3401 }
3402 }
3403
3404 if (time_changed)
3405 {
3406 double Mbps = 1024.0 * 1024.0 / 8 * time_changed;
3407
3408 // Log current traffic stats
3409 snprintf(config->bandwidth, sizeof(config->bandwidth),
3410 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3411 (udp_rx / Mbps), (eth_tx / Mbps), (eth_rx / Mbps), (udp_tx / Mbps),
3412 ((udp_tx + udp_rx + eth_tx + eth_rx) / Mbps),
3413 udp_rx_pkt / time_changed, eth_rx_pkt / time_changed);
3414
3415 udp_tx = udp_rx = 0;
3416 udp_rx_pkt = eth_rx_pkt = 0;
3417 eth_tx = eth_rx = 0;
3418 time_changed = 0;
3419
3420 if (config->dump_speed)
3421 printf("%s\n", config->bandwidth);
3422
3423 // Update the internal time counter
3424 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3425
3426 {
3427 // Run timer hooks
3428 struct param_timer p = { time_now };
3429 run_plugins(PLUGIN_TIMER, &p);
3430 }
3431 }
3432
3433 // Runs on every machine (master and slaves).
3434 if (next_cluster_ping <= TIME)
3435 {
3436 // Check to see which of the cluster is still alive..
3437
3438 cluster_send_ping(basetime); // Only does anything if we're a slave
3439 cluster_check_master(); // ditto.
3440
3441 cluster_heartbeat(); // Only does anything if we're a master.
3442 cluster_check_slaves(); // ditto.
3443
3444 master_update_counts(); // If we're a slave, send our byte counters to our master.
3445
3446 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3447 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3448 else
3449 next_cluster_ping = TIME + config->cluster_hb_interval;
3450 }
3451
3452 if (!config->cluster_iam_master)
3453 continue;
3454
3455 // Run token bucket filtering queue..
3456 // Only run it every 1/10th of a second.
3457 {
3458 static clockt last_run = 0;
3459 if (last_run != TIME)
3460 {
3461 last_run = TIME;
3462 tbf_run_timer();
3463 }
3464 }
3465
3466 // Handle timeouts, retries etc.
3467 {
3468 static double last_clean = 0;
3469 double this_clean;
3470 double diff;
3471
3472 TIME = now(&this_clean);
3473 diff = this_clean - last_clean;
3474
3475 // Run during idle time (after we've handled
3476 // all incoming packets) or every 1/10th sec
3477 if (!more || diff > 0.1)
3478 {
3479 regular_cleanups(diff);
3480 last_clean = this_clean;
3481 }
3482 }
3483
3484 if (*config->accounting_dir)
3485 {
3486 static clockt next_acct = 0;
3487 static clockt next_shut_acct = 0;
3488
3489 if (next_acct <= TIME)
3490 {
3491 // Dump accounting data
3492 next_acct = TIME + ACCT_TIME;
3493 next_shut_acct = TIME + ACCT_SHUT_TIME;
3494 dump_acct_info(1);
3495 }
3496 else if (next_shut_acct <= TIME)
3497 {
3498 // Dump accounting data for shutdown sessions
3499 next_shut_acct = TIME + ACCT_SHUT_TIME;
3500 if (shut_acct_n)
3501 dump_acct_info(0);
3502 }
3503 }
3504 }
3505
3506 // Are we the master and shutting down??
3507 if (config->cluster_iam_master)
3508 cluster_heartbeat(); // Flush any queued changes..
3509
3510 // Ok. Notify everyone we're shutting down. If we're
3511 // the master, this will force an election.
3512 cluster_send_ping(0);
3513
3514 //
3515 // Important!!! We MUST not process any packets past this point!
3516 LOG(1, 0, 0, "Shutdown complete\n");
3517 }
3518
3519 static void stripdomain(char *host)
3520 {
3521 char *p;
3522
3523 if ((p = strchr(host, '.')))
3524 {
3525 char *domain = 0;
3526 char _domain[1024];
3527
3528 // strip off domain
3529 FILE *resolv = fopen("/etc/resolv.conf", "r");
3530 if (resolv)
3531 {
3532 char buf[1024];
3533 char *b;
3534
3535 while (fgets(buf, sizeof(buf), resolv))
3536 {
3537 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3538 continue;
3539
3540 if (!isspace(buf[6]))
3541 continue;
3542
3543 b = buf + 7;
3544 while (isspace(*b)) b++;
3545
3546 if (*b)
3547 {
3548 char *d = b;
3549 while (*b && !isspace(*b)) b++;
3550 *b = 0;
3551 if (buf[0] == 'd') // domain is canonical
3552 {
3553 domain = d;
3554 break;
3555 }
3556
3557 // first search line
3558 if (!domain)
3559 {
3560 // hold, may be subsequent domain line
3561 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3562 domain = _domain;
3563 }
3564 }
3565 }
3566
3567 fclose(resolv);
3568 }
3569
3570 if (domain)
3571 {
3572 int hl = strlen(host);
3573 int dl = strlen(domain);
3574 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3575 host[hl -dl - 1] = 0;
3576 }
3577 else
3578 {
3579 *p = 0; // everything after first dot
3580 }
3581 }
3582 }
3583
3584 // Init data structures
3585 static void initdata(int optdebug, char *optconfig)
3586 {
3587 int i;
3588
3589 if (!(config = shared_malloc(sizeof(configt))))
3590 {
3591 fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
3592 exit(1);
3593 }
3594
3595 memset(config, 0, sizeof(configt));
3596 time(&config->start_time);
3597 strncpy(config->config_file, optconfig, strlen(optconfig));
3598 config->debug = optdebug;
3599 config->num_tbfs = MAXTBFS;
3600 config->rl_rate = 28; // 28kbps
3601 config->cluster_mcast_ttl = 1;
3602 config->cluster_master_min_adv = 1;
3603 config->ppp_restart_time = 3;
3604 config->ppp_max_configure = 10;
3605 config->ppp_max_failure = 5;
3606 strcpy(config->random_device, RANDOMDEVICE);
3607
3608 log_stream = stderr;
3609
3610 #ifdef RINGBUFFER
3611 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3612 {
3613 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3614 exit(1);
3615 }
3616 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3617 #endif
3618
3619 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3620 {
3621 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3622 exit(1);
3623 }
3624 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3625 {
3626 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3627 exit(1);
3628 }
3629 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3630 {
3631 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3632 exit(1);
3633 }
3634
3635 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3636 {
3637 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3638 exit(1);
3639 }
3640
3641 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3642 {
3643 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3644 exit(1);
3645 }
3646
3647 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3648 {
3649 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3650 exit(1);
3651 }
3652
3653 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3654 {
3655 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3656 exit(1);
3657 }
3658 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3659
3660 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3661 {
3662 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3663 exit(1);
3664 }
3665 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3666
3667 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3668 {
3669 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3670 exit(1);
3671 }
3672 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3673
3674 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3675 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3676 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3677 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3678
3679 // Put all the sessions on the free list marked as undefined.
3680 for (i = 1; i < MAXSESSION; i++)
3681 {
3682 session[i].next = i + 1;
3683 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3684 }
3685 session[MAXSESSION - 1].next = 0;
3686 sessionfree = 1;
3687
3688 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3689 for (i = 1; i < MAXTUNNEL; i++)
3690 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3691
3692 if (!*hostname)
3693 {
3694 // Grab my hostname unless it's been specified
3695 gethostname(hostname, sizeof(hostname));
3696 stripdomain(hostname);
3697 }
3698
3699 _statistics->start_time = _statistics->last_reset = time(NULL);
3700
3701 #ifdef BGP
3702 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3703 {
3704 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3705 exit(1);
3706 }
3707 #endif /* BGP */
3708 }
3709
3710 static int assign_ip_address(sessionidt s)
3711 {
3712 uint32_t i;
3713 int best = -1;
3714 time_t best_time = time_now;
3715 char *u = session[s].user;
3716 char reuse = 0;
3717
3718
3719 CSTAT(assign_ip_address);
3720
3721 for (i = 1; i < ip_pool_size; i++)
3722 {
3723 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3724 continue;
3725
3726 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3727 {
3728 best = i;
3729 reuse = 1;
3730 break;
3731 }
3732
3733 if (ip_address_pool[i].last < best_time)
3734 {
3735 best = i;
3736 if (!(best_time = ip_address_pool[i].last))
3737 break; // never used, grab this one
3738 }
3739 }
3740
3741 if (best < 0)
3742 {
3743 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3744 return 0;
3745 }
3746
3747 session[s].ip = ip_address_pool[best].address;
3748 session[s].ip_pool_index = best;
3749 ip_address_pool[best].assigned = 1;
3750 ip_address_pool[best].last = time_now;
3751 ip_address_pool[best].session = s;
3752 if (session[s].walled_garden)
3753 /* Don't track addresses of users in walled garden (note: this
3754 means that their address isn't "sticky" even if they get
3755 un-gardened). */
3756 ip_address_pool[best].user[0] = 0;
3757 else
3758 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3759
3760 STAT(ip_allocated);
3761 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3762 reuse ? "Reusing" : "Allocating", best);
3763
3764 return 1;
3765 }
3766
3767 static void free_ip_address(sessionidt s)
3768 {
3769 int i = session[s].ip_pool_index;
3770
3771
3772 CSTAT(free_ip_address);
3773
3774 if (!session[s].ip)
3775 return; // what the?
3776
3777 if (i < 0) // Is this actually part of the ip pool?
3778 i = 0;
3779
3780 STAT(ip_freed);
3781 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3782 session[s].ip = 0;
3783 ip_address_pool[i].assigned = 0;
3784 ip_address_pool[i].session = 0;
3785 ip_address_pool[i].last = time_now;
3786 }
3787
3788 //
3789 // Fsck the address pool against the session table.
3790 // Normally only called when we become a master.
3791 //
3792 // This isn't perfect: We aren't keep tracking of which
3793 // users used to have an IP address.
3794 //
3795 void rebuild_address_pool(void)
3796 {
3797 int i;
3798
3799 //
3800 // Zero the IP pool allocation, and build
3801 // a map from IP address to pool index.
3802 for (i = 1; i < MAXIPPOOL; ++i)
3803 {
3804 ip_address_pool[i].assigned = 0;
3805 ip_address_pool[i].session = 0;
3806 if (!ip_address_pool[i].address)
3807 continue;
3808
3809 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3810 }
3811
3812 for (i = 0; i < MAXSESSION; ++i)
3813 {
3814 int ipid;
3815 if (!(session[i].opened && session[i].ip))
3816 continue;
3817
3818 ipid = - lookup_ipmap(htonl(session[i].ip));
3819
3820 if (session[i].ip_pool_index < 0)
3821 {
3822 // Not allocated out of the pool.
3823 if (ipid < 1) // Not found in the pool either? good.
3824 continue;
3825
3826 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3827 i, fmtaddr(session[i].ip, 0), ipid);
3828
3829 // Fall through and process it as part of the pool.
3830 }
3831
3832
3833 if (ipid > MAXIPPOOL || ipid < 0)
3834 {
3835 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3836 ipid = -1;
3837 session[i].ip_pool_index = ipid;
3838 continue;
3839 }
3840
3841 ip_address_pool[ipid].assigned = 1;
3842 ip_address_pool[ipid].session = i;
3843 ip_address_pool[ipid].last = time_now;
3844 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3845 session[i].ip_pool_index = ipid;
3846 cache_ipmap(session[i].ip, i); // Fix the ip map.
3847 }
3848 }
3849
3850 //
3851 // Fix the address pool to match a changed session.
3852 // (usually when the master sends us an update).
3853 static void fix_address_pool(int sid)
3854 {
3855 int ipid;
3856
3857 ipid = session[sid].ip_pool_index;
3858
3859 if (ipid > ip_pool_size)
3860 return; // Ignore it. rebuild_address_pool will fix it up.
3861
3862 if (ip_address_pool[ipid].address != session[sid].ip)
3863 return; // Just ignore it. rebuild_address_pool will take care of it.
3864
3865 ip_address_pool[ipid].assigned = 1;
3866 ip_address_pool[ipid].session = sid;
3867 ip_address_pool[ipid].last = time_now;
3868 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3869 }
3870
3871 //
3872 // Add a block of addresses to the IP pool to hand out.
3873 //
3874 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3875 {
3876 int i;
3877 if (mask == 0)
3878 mask = 0xffffffff; // Host route only.
3879
3880 addr &= mask;
3881
3882 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3883 return ;
3884
3885 for (i = addr ;(i & mask) == addr; ++i)
3886 {
3887 if ((i & 0xff) == 0 || (i&0xff) == 255)
3888 continue; // Skip 0 and broadcast addresses.
3889
3890 ip_address_pool[ip_pool_size].address = i;
3891 ip_address_pool[ip_pool_size].assigned = 0;
3892 ++ip_pool_size;
3893 if (ip_pool_size >= MAXIPPOOL)
3894 {
3895 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3896 return;
3897 }
3898 }
3899 }
3900
3901 // Initialize the IP address pool
3902 static void initippool()
3903 {
3904 FILE *f;
3905 char *p;
3906 char buf[4096];
3907 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3908
3909 if (!(f = fopen(IPPOOLFILE, "r")))
3910 {
3911 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3912 exit(1);
3913 }
3914
3915 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3916 {
3917 char *pool = buf;
3918 buf[4095] = 0; // Force it to be zero terminated/
3919
3920 if (*buf == '#' || *buf == '\n')
3921 continue; // Skip comments / blank lines
3922 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3923 if ((p = (char *)strchr(buf, ':')))
3924 {
3925 in_addr_t src;
3926 *p = '\0';
3927 src = inet_addr(buf);
3928 if (src == INADDR_NONE)
3929 {
3930 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3931 exit(1);
3932 }
3933 // This entry is for a specific IP only
3934 if (src != config->bind_address)
3935 continue;
3936 *p = ':';
3937 pool = p+1;
3938 }
3939 if ((p = (char *)strchr(pool, '/')))
3940 {
3941 // It's a range
3942 int numbits = 0;
3943 in_addr_t start = 0, mask = 0;
3944
3945 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3946 *p++ = 0;
3947 if (!*p || !(numbits = atoi(p)))
3948 {
3949 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3950 continue;
3951 }
3952 start = ntohl(inet_addr(pool));
3953 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3954
3955 // Add a static route for this pool
3956 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3957 fmtaddr(htonl(start), 0), 32 + mask);
3958
3959 routeset(0, start, mask, 0, 1);
3960
3961 add_to_ip_pool(start, mask);
3962 }
3963 else
3964 {
3965 // It's a single ip address
3966 add_to_ip_pool(ntohl(inet_addr(pool)), 0);
3967 }
3968 }
3969 fclose(f);
3970 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3971 }
3972
3973 void snoop_send_packet(uint8_t *packet, uint16_t size, in_addr_t destination, uint16_t port)
3974 {
3975 struct sockaddr_in snoop_addr = {0};
3976 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3977 return;
3978
3979 snoop_addr.sin_family = AF_INET;
3980 snoop_addr.sin_addr.s_addr = destination;
3981 snoop_addr.sin_port = ntohs(port);
3982
3983 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3984 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3985 htons(snoop_addr.sin_port));
3986
3987 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3988 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
3989
3990 STAT(packets_snooped);
3991 }
3992
3993 static int dump_session(FILE **f, sessiont *s)
3994 {
3995 if (!s->opened || !s->ip || !(s->cin_delta || s->cout_delta) || !*s->user || s->walled_garden)
3996 return 1;
3997
3998 if (!*f)
3999 {
4000 char filename[1024];
4001 char timestr[64];
4002 time_t now = time(NULL);
4003
4004 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
4005 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
4006
4007 if (!(*f = fopen(filename, "w")))
4008 {
4009 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
4010 return 0;
4011 }
4012
4013 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
4014 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
4015 "# host: %s\n"
4016 "# endpoint: %s\n"
4017 "# time: %ld\n"
4018 "# uptime: %ld\n"
4019 "# format: username ip qos uptxoctets downrxoctets\n",
4020 hostname,
4021 fmtaddr(config->bind_address ? config->bind_address : my_address, 0),
4022 now,
4023 now - basetime);
4024 }
4025
4026 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
4027 fprintf(*f, "%s %s %d %u %u\n",
4028 s->user, // username
4029 fmtaddr(htonl(s->ip), 0), // ip
4030 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
4031 (uint32_t) s->cin_delta, // uptxoctets
4032 (uint32_t) s->cout_delta); // downrxoctets
4033
4034 s->cin_delta = s->cout_delta = 0;
4035
4036 return 1;
4037 }
4038
4039 static void dump_acct_info(int all)
4040 {
4041 int i;
4042 FILE *f = NULL;
4043
4044
4045 CSTAT(dump_acct_info);
4046
4047 if (shut_acct_n)
4048 {
4049 for (i = 0; i < shut_acct_n; i++)
4050 dump_session(&f, &shut_acct[i]);
4051
4052 shut_acct_n = 0;
4053 }
4054
4055 if (all)
4056 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4057 dump_session(&f, &session[i]);
4058
4059 if (f)
4060 fclose(f);
4061 }
4062
4063 // Main program
4064 int main(int argc, char *argv[])
4065 {
4066 int i;
4067 int optdebug = 0;
4068 char *optconfig = CONFIGFILE;
4069
4070 time(&basetime); // start clock
4071
4072 // scan args
4073 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
4074 {
4075 switch (i)
4076 {
4077 case 'd':
4078 if (fork()) exit(0);
4079 setsid();
4080 freopen("/dev/null", "r", stdin);
4081 freopen("/dev/null", "w", stdout);
4082 freopen("/dev/null", "w", stderr);
4083 break;
4084 case 'v':
4085 optdebug++;
4086 break;
4087 case 'c':
4088 optconfig = optarg;
4089 break;
4090 case 'h':
4091 snprintf(hostname, sizeof(hostname), "%s", optarg);
4092 break;
4093 default:
4094 printf("Args are:\n"
4095 "\t-d\t\tDetach from terminal\n"
4096 "\t-c <file>\tConfig file\n"
4097 "\t-h <hostname>\tForce hostname\n"
4098 "\t-v\t\tDebug\n");
4099
4100 return (0);
4101 break;
4102 }
4103 }
4104
4105 // Start the timer routine off
4106 time(&time_now);
4107 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
4108
4109 initplugins();
4110 initdata(optdebug, optconfig);
4111
4112 init_cli(hostname);
4113 read_config_file();
4114 update_config();
4115 init_tbf(config->num_tbfs);
4116
4117 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
4118 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
4119 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
4120 {
4121 struct rlimit rlim;
4122 rlim.rlim_cur = RLIM_INFINITY;
4123 rlim.rlim_max = RLIM_INFINITY;
4124 // Remove the maximum core size
4125 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
4126 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
4127
4128 // Make core dumps go to /tmp
4129 chdir("/tmp");
4130 }
4131
4132 if (config->scheduler_fifo)
4133 {
4134 int ret;
4135 struct sched_param params = {0};
4136 params.sched_priority = 1;
4137
4138 if (get_nprocs() < 2)
4139 {
4140 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
4141 config->scheduler_fifo = 0;
4142 }
4143 else
4144 {
4145 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
4146 {
4147 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
4148 }
4149 else
4150 {
4151 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
4152 config->scheduler_fifo = 0;
4153 }
4154 }
4155 }
4156
4157 /* Set up the cluster communications port. */
4158 if (cluster_init() < 0)
4159 exit(1);
4160
4161 inittun();
4162 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
4163
4164 initudp();
4165 initrad();
4166 initippool();
4167
4168 // seed prng
4169 {
4170 unsigned seed = time_now ^ getpid();
4171 LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
4172 srand(seed);
4173 }
4174
4175 signal(SIGHUP, sighup_handler);
4176 signal(SIGCHLD, sigchild_handler);
4177 signal(SIGTERM, shutdown_handler);
4178 signal(SIGINT, shutdown_handler);
4179 signal(SIGQUIT, shutdown_handler);
4180
4181 // Prevent us from getting paged out
4182 if (config->lock_pages)
4183 {
4184 if (!mlockall(MCL_CURRENT))
4185 LOG(1, 0, 0, "Locking pages into memory\n");
4186 else
4187 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
4188 }
4189
4190 // Drop privileges here
4191 if (config->target_uid > 0 && geteuid() == 0)
4192 setuid(config->target_uid);
4193
4194 mainloop();
4195
4196 /* remove plugins (so cleanup code gets run) */
4197 plugins_done();
4198
4199 // Remove the PID file if we wrote it
4200 if (config->wrote_pid && *config->pid_file == '/')
4201 unlink(config->pid_file);
4202
4203 /* kill CLI children */
4204 signal(SIGTERM, SIG_IGN);
4205 kill(0, SIGTERM);
4206 return 0;
4207 }
4208
4209 static void sighup_handler(int sig)
4210 {
4211 main_reload++;
4212 }
4213
4214 static void shutdown_handler(int sig)
4215 {
4216 main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
4217 }
4218
4219 static void sigchild_handler(int sig)
4220 {
4221 while (waitpid(-1, NULL, WNOHANG) > 0)
4222 ;
4223 }
4224
4225 static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response)
4226 {
4227 MD5_CTX ctx;
4228 *challenge_response = NULL;
4229
4230 if (!*config->l2tp_secret)
4231 {
4232 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
4233 return;
4234 }
4235
4236 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
4237
4238 *challenge_response = calloc(17, 1);
4239
4240 MD5_Init(&ctx);
4241 MD5_Update(&ctx, &id, 1);
4242 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
4243 MD5_Update(&ctx, challenge, challenge_length);
4244 MD5_Final(*challenge_response, &ctx);
4245
4246 return;
4247 }
4248
4249 static int facility_value(char *name)
4250 {
4251 int i;
4252 for (i = 0; facilitynames[i].c_name; i++)
4253 {
4254 if (strcmp(facilitynames[i].c_name, name) == 0)
4255 return facilitynames[i].c_val;
4256 }
4257 return 0;
4258 }
4259
4260 static void update_config()
4261 {
4262 int i;
4263 char *p;
4264 static int timeout = 0;
4265 static int interval = 0;
4266
4267 // Update logging
4268 closelog();
4269 syslog_log = 0;
4270 if (log_stream)
4271 {
4272 if (log_stream != stderr)
4273 fclose(log_stream);
4274
4275 log_stream = NULL;
4276 }
4277
4278 if (*config->log_filename)
4279 {
4280 if (strstr(config->log_filename, "syslog:") == config->log_filename)
4281 {
4282 char *p = config->log_filename + 7;
4283 if (*p)
4284 {
4285 openlog("l2tpns", LOG_PID, facility_value(p));
4286 syslog_log = 1;
4287 }
4288 }
4289 else if (strchr(config->log_filename, '/') == config->log_filename)
4290 {
4291 if ((log_stream = fopen((char *)(config->log_filename), "a")))
4292 {
4293 fseek(log_stream, 0, SEEK_END);
4294 setbuf(log_stream, NULL);
4295 }
4296 else
4297 {
4298 log_stream = stderr;
4299 setbuf(log_stream, NULL);
4300 }
4301 }
4302 }
4303 else
4304 {
4305 log_stream = stderr;
4306 setbuf(log_stream, NULL);
4307 }
4308
4309 #define L2TP_HDRS (20+8+6+4) // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
4310 #define TCP_HDRS (20+20) // TCP encapsulation: ip + tcp
4311
4312 if (config->l2tp_mtu <= 0) config->l2tp_mtu = 1500; // ethernet default
4313 else if (config->l2tp_mtu < MINMTU) config->l2tp_mtu = MINMTU;
4314 else if (config->l2tp_mtu > MAXMTU) config->l2tp_mtu = MAXMTU;
4315
4316 // reset MRU/MSS globals
4317 MRU = config->l2tp_mtu - L2TP_HDRS;
4318 if (MRU > PPPoE_MRU)
4319 MRU = PPPoE_MRU;
4320
4321 MSS = MRU - TCP_HDRS;
4322
4323 // Update radius
4324 config->numradiusservers = 0;
4325 for (i = 0; i < MAXRADSERVER; i++)
4326 if (config->radiusserver[i])
4327 {
4328 config->numradiusservers++;
4329 // Set radius port: if not set, take the port from the
4330 // first radius server. For the first radius server,
4331 // take the #defined default value from l2tpns.h
4332
4333 // test twice, In case someone works with
4334 // a secondary radius server without defining
4335 // a primary one, this will work even then.
4336 if (i > 0 && !config->radiusport[i])
4337 config->radiusport[i] = config->radiusport[i-1];
4338 if (!config->radiusport[i])
4339 config->radiusport[i] = RADPORT;
4340 }
4341
4342 if (!config->numradiusservers)
4343 LOG(0, 0, 0, "No RADIUS servers defined!\n");
4344
4345 // parse radius_authtypes_s
4346 config->radius_authtypes = config->radius_authprefer = 0;
4347 p = config->radius_authtypes_s;
4348 while (p && *p)
4349 {
4350 char *s = strpbrk(p, " \t,");
4351 int type = 0;
4352
4353 if (s)
4354 {
4355 *s++ = 0;
4356 while (*s == ' ' || *s == '\t')
4357 s++;
4358
4359 if (!*s)
4360 s = 0;
4361 }
4362
4363 if (!strncasecmp("chap", p, strlen(p)))
4364 type = AUTHCHAP;
4365 else if (!strncasecmp("pap", p, strlen(p)))
4366 type = AUTHPAP;
4367 else
4368 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
4369
4370 config->radius_authtypes |= type;
4371 if (!config->radius_authprefer)
4372 config->radius_authprefer = type;
4373
4374 p = s;
4375 }
4376
4377 if (!config->radius_authtypes)
4378 {
4379 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
4380 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
4381 }
4382
4383 // normalise radius_authtypes_s
4384 if (config->radius_authprefer == AUTHPAP)
4385 {
4386 strcpy(config->radius_authtypes_s, "pap");
4387 if (config->radius_authtypes & AUTHCHAP)
4388 strcat(config->radius_authtypes_s, ", chap");
4389 }
4390 else
4391 {
4392 strcpy(config->radius_authtypes_s, "chap");
4393 if (config->radius_authtypes & AUTHPAP)
4394 strcat(config->radius_authtypes_s, ", pap");
4395 }
4396
4397 if (!config->radius_dae_port)
4398 config->radius_dae_port = DAEPORT;
4399
4400 // re-initialise the random number source
4401 initrandom(config->random_device);
4402
4403 // Update plugins
4404 for (i = 0; i < MAXPLUGINS; i++)
4405 {
4406 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4407 continue;
4408
4409 if (*config->plugins[i])
4410 {
4411 // Plugin added
4412 add_plugin(config->plugins[i]);
4413 }
4414 else if (*config->old_plugins[i])
4415 {
4416 // Plugin removed
4417 remove_plugin(config->old_plugins[i]);
4418 }
4419 }
4420
4421 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4422 if (!config->multi_read_count) config->multi_read_count = 10;
4423 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4424 if (!*config->cluster_interface)
4425 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4426
4427 if (!config->cluster_hb_interval)
4428 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4429
4430 if (!config->cluster_hb_timeout)
4431 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4432
4433 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4434 {
4435 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4436 // late, ensure we're sufficiently larger than that
4437 int t = 4 * config->cluster_hb_interval + 11;
4438
4439 if (config->cluster_hb_timeout < t)
4440 {
4441 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4442 config->cluster_hb_timeout = t;
4443 }
4444
4445 // Push timing changes to the slaves immediately if we're the master
4446 if (config->cluster_iam_master)
4447 cluster_heartbeat();
4448
4449 interval = config->cluster_hb_interval;
4450 timeout = config->cluster_hb_timeout;
4451 }
4452
4453 // Write PID file
4454 if (*config->pid_file == '/' && !config->wrote_pid)
4455 {
4456 FILE *f;
4457 if ((f = fopen(config->pid_file, "w")))
4458 {
4459 fprintf(f, "%d\n", getpid());
4460 fclose(f);
4461 config->wrote_pid = 1;
4462 }
4463 else
4464 {
4465 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4466 }
4467 }
4468 }
4469
4470 static void read_config_file()
4471 {
4472 FILE *f;
4473
4474 if (!config->config_file) return;
4475 if (!(f = fopen(config->config_file, "r")))
4476 {
4477 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4478 return;
4479 }
4480
4481 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4482 cli_do_file(f);
4483 LOG(3, 0, 0, "Done reading config file\n");
4484 fclose(f);
4485 }
4486
4487 int sessionsetup(sessionidt s, tunnelidt t)
4488 {
4489 // A session now exists, set it up
4490 in_addr_t ip;
4491 char *user;
4492 sessionidt i;
4493 int r;
4494
4495 CSTAT(sessionsetup);
4496
4497 LOG(3, s, t, "Doing session setup for session\n");
4498
4499 if (!session[s].ip)
4500 {
4501 assign_ip_address(s);
4502 if (!session[s].ip)
4503 {
4504 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4505 sessionshutdown(s, "No IP addresses available.", 2, 7); // try another
4506 return 0;
4507 }
4508 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4509 fmtaddr(htonl(session[s].ip), 0));
4510 }
4511
4512
4513 // Make sure this is right
4514 session[s].tunnel = t;
4515
4516 // zap old sessions with same IP and/or username
4517 // Don't kill gardened sessions - doing so leads to a DoS
4518 // from someone who doesn't need to know the password
4519 {
4520 ip = session[s].ip;
4521 user = session[s].user;
4522 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4523 {
4524 if (i == s) continue;
4525 if (!session[s].opened) continue;
4526 if (ip == session[i].ip)
4527 {
4528 sessionkill(i, "Duplicate IP address");
4529 continue;
4530 }
4531
4532 if (config->allow_duplicate_users) continue;
4533 if (session[s].walled_garden || session[i].walled_garden) continue;
4534 if (!strcasecmp(user, session[i].user))
4535 sessionkill(i, "Duplicate session for users");
4536 }
4537 }
4538
4539 {
4540 int routed = 0;
4541
4542 // Add the route for this session.
4543 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4544 {
4545 if ((session[s].ip & session[s].route[r].mask) ==
4546 (session[s].route[r].ip & session[s].route[r].mask))
4547 routed++;
4548
4549 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4550 }
4551
4552 // Static IPs need to be routed if not already
4553 // convered by a Framed-Route. Anything else is part
4554 // of the IP address pool and is already routed, it
4555 // just needs to be added to the IP cache.
4556 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4557 if (session[s].ip_pool_index == -1) // static ip
4558 {
4559 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4560 }
4561 else
4562 cache_ipmap(session[s].ip, s);
4563 }
4564
4565 sess_local[s].lcp_authtype = 0; // RADIUS authentication complete
4566 lcp_open(s, t); // transition to Network phase and send initial IPCP
4567
4568 // Run the plugin's against this new session.
4569 {
4570 struct param_new_session data = { &tunnel[t], &session[s] };
4571 run_plugins(PLUGIN_NEW_SESSION, &data);
4572 }
4573
4574 // Allocate TBFs if throttled
4575 if (session[s].throttle_in || session[s].throttle_out)
4576 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4577
4578 session[s].last_packet = time_now;
4579
4580 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4581 fmtaddr(htonl(session[s].ip), 0),
4582 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4583
4584 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4585
4586 return 1; // RADIUS OK and IP allocated, done...
4587 }
4588
4589 //
4590 // This session just got dropped on us by the master or something.
4591 // Make sure our tables up up to date...
4592 //
4593 int load_session(sessionidt s, sessiont *new)
4594 {
4595 int i;
4596 int newip = 0;
4597
4598 // Sanity checks.
4599 if (new->ip_pool_index >= MAXIPPOOL ||
4600 new->tunnel >= MAXTUNNEL)
4601 {
4602 LOG(0, s, 0, "Strange session update received!\n");
4603 // FIXME! What to do here?
4604 return 0;
4605 }
4606
4607 //
4608 // Ok. All sanity checks passed. Now we're committed to
4609 // loading the new session.
4610 //
4611
4612 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4613
4614 // See if routes/ip cache need updating
4615 if (new->ip != session[s].ip)
4616 newip++;
4617
4618 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4619 if (new->route[i].ip != session[s].route[i].ip ||
4620 new->route[i].mask != session[s].route[i].mask)
4621 newip++;
4622
4623 // needs update
4624 if (newip)
4625 {
4626 int routed = 0;
4627
4628 // remove old routes...
4629 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4630 {
4631 if ((session[s].ip & session[s].route[i].mask) ==
4632 (session[s].route[i].ip & session[s].route[i].mask))
4633 routed++;
4634
4635 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4636 }
4637
4638 // ...ip
4639 if (session[s].ip)
4640 {
4641 if (session[s].ip_pool_index == -1) // static IP
4642 {
4643 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4644 }
4645 else // It's part of the IP pool, remove it manually.
4646 uncache_ipmap(session[s].ip);
4647 }
4648
4649 routed = 0;
4650
4651 // add new routes...
4652 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4653 {
4654 if ((new->ip & new->route[i].mask) ==
4655 (new->route[i].ip & new->route[i].mask))
4656 routed++;
4657
4658 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4659 }
4660
4661 // ...ip
4662 if (new->ip)
4663 {
4664 // If there's a new one, add it.
4665 if (new->ip_pool_index == -1)
4666 {
4667 if (!routed) routeset(s, new->ip, 0, 0, 1);
4668 }
4669 else
4670 cache_ipmap(new->ip, s);
4671 }
4672 }
4673
4674 // check v6 routing
4675 if (new->ipv6prefixlen && new->ppp.ipv6cp == Opened && session[s].ppp.ipv6cp != Opened)
4676 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4677
4678 // check filters
4679 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4680 {
4681 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4682 new->filter_in = 0;
4683 }
4684
4685 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4686 {
4687 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4688 new->filter_out = 0;
4689 }
4690
4691 if (new->filter_in != session[s].filter_in)
4692 {
4693 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4694 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4695 }
4696
4697 if (new->filter_out != session[s].filter_out)
4698 {
4699 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4700 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4701 }
4702
4703 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4704 // for walking the sessions to forward byte counts to the master.
4705 config->cluster_highest_sessionid = s;
4706
4707 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4708
4709 // Do fixups into address pool.
4710 if (new->ip_pool_index != -1)
4711 fix_address_pool(s);
4712
4713 return 1;
4714 }
4715
4716 static void initplugins()
4717 {
4718 int i;
4719
4720 loaded_plugins = ll_init();
4721 // Initialize the plugins to nothing
4722 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4723 plugins[i] = ll_init();
4724 }
4725
4726 static void *open_plugin(char *plugin_name, int load)
4727 {
4728 char path[256] = "";
4729
4730 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4731 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4732 return dlopen(path, RTLD_NOW);
4733 }
4734
4735 // plugin callback to get a config value
4736 static void *getconfig(char *key, enum config_typet type)
4737 {
4738 int i;
4739
4740 for (i = 0; config_values[i].key; i++)
4741 {
4742 if (!strcmp(config_values[i].key, key))
4743 {
4744 if (config_values[i].type == type)
4745 return ((void *) config) + config_values[i].offset;
4746
4747 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4748 key, type, config_values[i].type);
4749
4750 return 0;
4751 }
4752 }
4753
4754 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4755 return 0;
4756 }
4757
4758 static int add_plugin(char *plugin_name)
4759 {
4760 static struct pluginfuncs funcs = {
4761 _log,
4762 _log_hex,
4763 fmtaddr,
4764 sessionbyuser,
4765 sessiontbysessionidt,
4766 sessionidtbysessiont,
4767 radiusnew,
4768 radiussend,
4769 getconfig,
4770 sessionshutdown,
4771 sessionkill,
4772 throttle_session,
4773 cluster_send_session,
4774 };
4775
4776 void *p = open_plugin(plugin_name, 1);
4777 int (*initfunc)(struct pluginfuncs *);
4778 int i;
4779
4780 if (!p)
4781 {
4782 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4783 return -1;
4784 }
4785
4786 if (ll_contains(loaded_plugins, p))
4787 {
4788 dlclose(p);
4789 return 0; // already loaded
4790 }
4791
4792 {
4793 int *v = dlsym(p, "plugin_api_version");
4794 if (!v || *v != PLUGIN_API_VERSION)
4795 {
4796 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4797 dlclose(p);
4798 return -1;
4799 }
4800 }
4801
4802 if ((initfunc = dlsym(p, "plugin_init")))
4803 {
4804 if (!initfunc(&funcs))
4805 {
4806 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4807 dlclose(p);
4808 return -1;
4809 }
4810 }
4811
4812 ll_push(loaded_plugins, p);
4813
4814 for (i = 0; i < max_plugin_functions; i++)
4815 {
4816 void *x;
4817 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4818 {
4819 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4820 ll_push(plugins[i], x);
4821 }
4822 }
4823
4824 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4825 return 1;
4826 }
4827
4828 static void run_plugin_done(void *plugin)
4829 {
4830 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4831
4832 if (donefunc)
4833 donefunc();
4834 }
4835
4836 static int remove_plugin(char *plugin_name)
4837 {
4838 void *p = open_plugin(plugin_name, 0);
4839 int loaded = 0;
4840
4841 if (!p)
4842 return -1;
4843
4844 if (ll_contains(loaded_plugins, p))
4845 {
4846 int i;
4847 for (i = 0; i < max_plugin_functions; i++)
4848 {
4849 void *x;
4850 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4851 ll_delete(plugins[i], x);
4852 }
4853
4854 ll_delete(loaded_plugins, p);
4855 run_plugin_done(p);
4856 loaded = 1;
4857 }
4858
4859 dlclose(p);
4860 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4861 return loaded;
4862 }
4863
4864 int run_plugins(int plugin_type, void *data)
4865 {
4866 int (*func)(void *data);
4867
4868 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4869 return PLUGIN_RET_ERROR;
4870
4871 ll_reset(plugins[plugin_type]);
4872 while ((func = ll_next(plugins[plugin_type])))
4873 {
4874 int r = func(data);
4875
4876 if (r != PLUGIN_RET_OK)
4877 return r; // stop here
4878 }
4879
4880 return PLUGIN_RET_OK;
4881 }
4882
4883 static void plugins_done()
4884 {
4885 void *p;
4886
4887 ll_reset(loaded_plugins);
4888 while ((p = ll_next(loaded_plugins)))
4889 run_plugin_done(p);
4890 }
4891
4892 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struct in_addr *local)
4893 {
4894 struct nsctl request;
4895 struct nsctl response;
4896 int type = unpack_control(&request, buf, len);
4897 int r;
4898 void *p;
4899
4900 if (log_stream && config->debug >= 4)
4901 {
4902 if (type < 0)
4903 {
4904 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4905 fmtaddr(addr->sin_addr.s_addr, 0), type);
4906 }
4907 else
4908 {
4909 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4910 dump_control(&request, log_stream);
4911 }
4912 }
4913
4914 switch (type)
4915 {
4916 case NSCTL_REQ_LOAD:
4917 if (request.argc != 1)
4918 {
4919 response.type = NSCTL_RES_ERR;
4920 response.argc = 1;
4921 response.argv[0] = "name of plugin required";
4922 }
4923 else if ((r = add_plugin(request.argv[0])) < 1)
4924 {
4925 response.type = NSCTL_RES_ERR;
4926 response.argc = 1;
4927 response.argv[0] = !r
4928 ? "plugin already loaded"
4929 : "error loading plugin";
4930 }
4931 else
4932 {
4933 response.type = NSCTL_RES_OK;
4934 response.argc = 0;
4935 }
4936
4937 break;
4938
4939 case NSCTL_REQ_UNLOAD:
4940 if (request.argc != 1)
4941 {
4942 response.type = NSCTL_RES_ERR;
4943 response.argc = 1;
4944 response.argv[0] = "name of plugin required";
4945 }
4946 else if ((r = remove_plugin(request.argv[0])) < 1)
4947 {
4948 response.type = NSCTL_RES_ERR;
4949 response.argc = 1;
4950 response.argv[0] = !r
4951 ? "plugin not loaded"
4952 : "plugin not found";
4953 }
4954 else
4955 {
4956 response.type = NSCTL_RES_OK;
4957 response.argc = 0;
4958 }
4959
4960 break;
4961
4962 case NSCTL_REQ_HELP:
4963 response.type = NSCTL_RES_OK;
4964 response.argc = 0;
4965
4966 ll_reset(loaded_plugins);
4967 while ((p = ll_next(loaded_plugins)))
4968 {
4969 char **help = dlsym(p, "plugin_control_help");
4970 while (response.argc < 0xff && help && *help)
4971 response.argv[response.argc++] = *help++;
4972 }
4973
4974 break;
4975
4976 case NSCTL_REQ_CONTROL:
4977 {
4978 struct param_control param = {
4979 config->cluster_iam_master,
4980 request.argc,
4981 request.argv,
4982 0,
4983 NULL,
4984 };
4985
4986 int r = run_plugins(PLUGIN_CONTROL, &param);
4987
4988 if (r == PLUGIN_RET_ERROR)
4989 {
4990 response.type = NSCTL_RES_ERR;
4991 response.argc = 1;
4992 response.argv[0] = param.additional
4993 ? param.additional
4994 : "error returned by plugin";
4995 }
4996 else if (r == PLUGIN_RET_NOTMASTER)
4997 {
4998 static char msg[] = "must be run on master: 000.000.000.000";
4999
5000 response.type = NSCTL_RES_ERR;
5001 response.argc = 1;
5002 if (config->cluster_master_address)
5003 {
5004 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
5005 response.argv[0] = msg;
5006 }
5007 else
5008 {
5009 response.argv[0] = "must be run on master: none elected";
5010 }
5011 }
5012 else if (!(param.response & NSCTL_RESPONSE))
5013 {
5014 response.type = NSCTL_RES_ERR;
5015 response.argc = 1;
5016 response.argv[0] = param.response
5017 ? "unrecognised response value from plugin"
5018 : "unhandled action";
5019 }
5020 else
5021 {
5022 response.type = param.response;
5023 response.argc = 0;
5024 if (param.additional)
5025 {
5026 response.argc = 1;
5027 response.argv[0] = param.additional;
5028 }
5029 }
5030 }
5031
5032 break;
5033
5034 default:
5035 response.type = NSCTL_RES_ERR;
5036 response.argc = 1;
5037 response.argv[0] = "error unpacking control packet";
5038 }
5039
5040 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
5041 if (!buf)
5042 {
5043 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
5044 return;
5045 }
5046
5047 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
5048 if (r > 0)
5049 {
5050 sendtofrom(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen, local);
5051 if (log_stream && config->debug >= 4)
5052 {
5053 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
5054 dump_control(&response, log_stream);
5055 }
5056 }
5057 else
5058 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
5059 fmtaddr(addr->sin_addr.s_addr, 0), r);
5060
5061 free(buf);
5062 }
5063
5064 static tunnelidt new_tunnel()
5065 {
5066 tunnelidt i;
5067 for (i = 1; i < MAXTUNNEL; i++)
5068 {
5069 if (tunnel[i].state == TUNNELFREE)
5070 {
5071 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
5072 if (i > config->cluster_highest_tunnelid)
5073 config->cluster_highest_tunnelid = i;
5074 return i;
5075 }
5076 }
5077 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
5078 return 0;
5079 }
5080
5081 //
5082 // We're becoming the master. Do any required setup..
5083 //
5084 // This is principally telling all the plugins that we're
5085 // now a master, and telling them about all the sessions
5086 // that are active too..
5087 //
5088 void become_master(void)
5089 {
5090 int s, i;
5091 static struct event_data d[RADIUS_FDS];
5092 struct epoll_event e;
5093
5094 run_plugins(PLUGIN_BECOME_MASTER, NULL);
5095
5096 // running a bunch of iptables commands is slow and can cause
5097 // the master to drop tunnels on takeover--kludge around the
5098 // problem by forking for the moment (note: race)
5099 if (!fork_and_close())
5100 {
5101 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5102 {
5103 if (!session[s].opened) // Not an in-use session.
5104 continue;
5105
5106 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
5107 }
5108 exit(0);
5109 }
5110
5111 // add radius fds
5112 e.events = EPOLLIN;
5113 for (i = 0; i < RADIUS_FDS; i++)
5114 {
5115 d[i].type = FD_TYPE_RADIUS;
5116 d[i].index = i;
5117 e.data.ptr = &d[i];
5118
5119 epoll_ctl(epollfd, EPOLL_CTL_ADD, radfds[i], &e);
5120 }
5121 }
5122
5123 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
5124 {
5125 int s, i;
5126 int count = 0;
5127 int buckets[64];
5128
5129 if (CLI_HELP_REQUESTED)
5130 return CLI_HELP_NO_ARGS;
5131
5132 time(&time_now);
5133 for (i = 0; i < 64;++i) buckets[i] = 0;
5134
5135 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5136 {
5137 int idle;
5138 if (!session[s].opened)
5139 continue;
5140
5141 idle = time_now - session[s].last_packet;
5142 idle /= 5 ; // In multiples of 5 seconds.
5143 if (idle < 0)
5144 idle = 0;
5145 if (idle > 63)
5146 idle = 63;
5147
5148 ++count;
5149 ++buckets[idle];
5150 }
5151
5152 for (i = 0; i < 63; ++i)
5153 {
5154 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
5155 }
5156 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
5157 cli_print(cli, "%d total sessions open.", count);
5158 return CLI_OK;
5159 }
5160
5161 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
5162 {
5163 int s, i;
5164 int count = 0;
5165 int buckets[64];
5166
5167 if (CLI_HELP_REQUESTED)
5168 return CLI_HELP_NO_ARGS;
5169
5170 time(&time_now);
5171 for (i = 0; i < 64;++i) buckets[i] = 0;
5172
5173 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5174 {
5175 int open = 0, d;
5176 if (!session[s].opened)
5177 continue;
5178
5179 d = time_now - session[s].opened;
5180 if (d < 0)
5181 d = 0;
5182 while (d > 1 && open < 32)
5183 {
5184 ++open;
5185 d >>= 1; // half.
5186 }
5187 ++count;
5188 ++buckets[open];
5189 }
5190
5191 s = 1;
5192 for (i = 0; i < 30; ++i)
5193 {
5194 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
5195 s <<= 1;
5196 }
5197 cli_print(cli, "%d total sessions open.", count);
5198 return CLI_OK;
5199 }
5200
5201 /* Unhide an avp.
5202 *
5203 * This unencodes the AVP using the L2TP secret and the previously
5204 * stored random vector. It overwrites the hidden data with the
5205 * unhidden AVP subformat.
5206 */
5207 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
5208 {
5209 MD5_CTX ctx;
5210 uint8_t digest[16];
5211 uint8_t *last;
5212 size_t d = 0;
5213 uint16_t m = htons(type);
5214
5215 // Compute initial pad
5216 MD5_Init(&ctx);
5217 MD5_Update(&ctx, (unsigned char *) &m, 2);
5218 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
5219 MD5_Update(&ctx, vector, vec_len);
5220 MD5_Final(digest, &ctx);
5221
5222 // pointer to last decoded 16 octets
5223 last = value;
5224
5225 while (len > 0)
5226 {
5227 // calculate a new pad based on the last decoded block
5228 if (d >= sizeof(digest))
5229 {
5230 MD5_Init(&ctx);
5231 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
5232 MD5_Update(&ctx, last, sizeof(digest));
5233 MD5_Final(digest, &ctx);
5234
5235 d = 0;
5236 last = value;
5237 }
5238
5239 *value++ ^= digest[d++];
5240 len--;
5241 }
5242 }
5243
5244 int find_filter(char const *name, size_t len)
5245 {
5246 int free = -1;
5247 int i;
5248
5249 for (i = 0; i < MAXFILTER; i++)
5250 {
5251 if (!*ip_filters[i].name)
5252 {
5253 if (free < 0)
5254 free = i;
5255
5256 continue;
5257 }
5258
5259 if (strlen(ip_filters[i].name) != len)
5260 continue;
5261
5262 if (!strncmp(ip_filters[i].name, name, len))
5263 return i;
5264 }
5265
5266 return free;
5267 }
5268
5269 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
5270 {
5271 switch (p->op)
5272 {
5273 case FILTER_PORT_OP_EQ: return port == p->port;
5274 case FILTER_PORT_OP_NEQ: return port != p->port;
5275 case FILTER_PORT_OP_GT: return port > p->port;
5276 case FILTER_PORT_OP_LT: return port < p->port;
5277 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
5278 }
5279
5280 return 0;
5281 }
5282
5283 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
5284 {
5285 switch (op)
5286 {
5287 case FILTER_FLAG_OP_ANY:
5288 return (flags & sflags) || (~flags & cflags);
5289
5290 case FILTER_FLAG_OP_ALL:
5291 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
5292
5293 case FILTER_FLAG_OP_EST:
5294 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
5295 }
5296
5297 return 0;
5298 }
5299
5300 int ip_filter(uint8_t *buf, int len, uint8_t filter)
5301 {
5302 uint16_t frag_offset;
5303 uint8_t proto;
5304 in_addr_t src_ip;
5305 in_addr_t dst_ip;
5306 uint16_t src_port = 0;
5307 uint16_t dst_port = 0;
5308 uint8_t flags = 0;
5309 ip_filter_rulet *rule;
5310
5311 if (len < 20) // up to end of destination address
5312 return 0;
5313
5314 if ((*buf >> 4) != 4) // IPv4
5315 return 0;
5316
5317 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
5318 proto = buf[9];
5319 src_ip = *(in_addr_t *) (buf + 12);
5320 dst_ip = *(in_addr_t *) (buf + 16);
5321
5322 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
5323 {
5324 int l = (buf[0] & 0xf) * 4; // length of IP header
5325 if (len < l + 4) // ports
5326 return 0;
5327
5328 src_port = ntohs(*(uint16_t *) (buf + l));
5329 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
5330 if (proto == IPPROTO_TCP)
5331 {
5332 if (len < l + 14) // flags
5333 return 0;
5334
5335 flags = buf[l + 13] & 0x3f;
5336 }
5337 }
5338
5339 for (rule = ip_filters[filter].rules; rule->action; rule++)
5340 {
5341 if (rule->proto != IPPROTO_IP && proto != rule->proto)
5342 continue;
5343
5344 if (rule->src_wild != INADDR_BROADCAST &&
5345 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
5346 continue;
5347
5348 if (rule->dst_wild != INADDR_BROADCAST &&
5349 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
5350 continue;
5351
5352 if (frag_offset)
5353 {
5354 // layer 4 deny rules are skipped
5355 if (rule->action == FILTER_ACTION_DENY &&
5356 (rule->src_ports.op || rule->dst_ports.op || rule->tcp_flag_op))
5357 continue;
5358 }
5359 else
5360 {
5361 if (rule->frag)
5362 continue;
5363
5364 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
5365 {
5366 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
5367 continue;
5368
5369 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
5370 continue;
5371
5372 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
5373 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
5374 continue;
5375 }
5376 }
5377
5378 // matched
5379 rule->counter++;
5380 return rule->action == FILTER_ACTION_PERMIT;
5381 }
5382
5383 // default deny
5384 return 0;
5385 }