534601eebc72ac775c723cfc5b6bfffacf5b49d1
[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 1.151 2005-12-07 05:21:37 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);
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 + 4 (tun header) */
558 ifr.ifr_mtu = MRU + 4;
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 if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
638 {
639 LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
640 exit(1);
641 }
642
643 // Dynamic Authorization Extensions to RADIUS
644 memset(&addr, 0, sizeof(addr));
645 addr.sin_family = AF_INET;
646 addr.sin_port = htons(config->radius_dae_port);
647 daefd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
648 setsockopt(daefd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
649 if (bind(daefd, (void *) &addr, sizeof(addr)) < 0)
650 {
651 LOG(0, 0, 0, "Error in DAE bind: %s\n", strerror(errno));
652 exit(1);
653 }
654
655 // Intercept
656 snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
657 }
658
659 //
660 // Find session by IP, < 1 for not found
661 //
662 // Confusingly enough, this 'ip' must be
663 // in _network_ order. This being the common
664 // case when looking it up from IP packet headers.
665 //
666 // We actually use this cache for two things.
667 // #1. For used IP addresses, this maps to the
668 // session ID that it's used by.
669 // #2. For un-used IP addresses, this maps to the
670 // index into the pool table that contains that
671 // IP address.
672 //
673
674 static int lookup_ipmap(in_addr_t ip)
675 {
676 uint8_t *a = (uint8_t *) &ip;
677 uint8_t **d = (uint8_t **) ip_hash;
678
679 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
680 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
681 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
682
683 return (int) (intptr_t) d[(size_t) *a];
684 }
685
686 static int lookup_ipv6map(struct in6_addr ip)
687 {
688 struct ipv6radix *curnode;
689 int i;
690 int s;
691 char ipv6addr[INET6_ADDRSTRLEN];
692
693 curnode = &ipv6_hash[ip.s6_addr[0]];
694 i = 1;
695 s = curnode->sess;
696
697 while (s == 0 && i < 15 && curnode->branch != NULL)
698 {
699 curnode = &curnode->branch[ip.s6_addr[i]];
700 s = curnode->sess;
701 i++;
702 }
703
704 LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
705 inet_ntop(AF_INET6, &ip, ipv6addr,
706 INET6_ADDRSTRLEN),
707 s);
708
709 return s;
710 }
711
712 sessionidt sessionbyip(in_addr_t ip)
713 {
714 int s = lookup_ipmap(ip);
715 CSTAT(sessionbyip);
716
717 if (s > 0 && s < MAXSESSION && session[s].opened)
718 return (sessionidt) s;
719
720 return 0;
721 }
722
723 sessionidt sessionbyipv6(struct in6_addr ip)
724 {
725 int s;
726 CSTAT(sessionbyipv6);
727
728 if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
729 (ip.s6_addr[0] == 0xFE &&
730 ip.s6_addr[1] == 0x80 &&
731 ip.s6_addr16[1] == 0 &&
732 ip.s6_addr16[2] == 0 &&
733 ip.s6_addr16[3] == 0)) {
734 s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
735 } else {
736 s = lookup_ipv6map(ip);
737 }
738
739 if (s > 0 && s < MAXSESSION && session[s].opened)
740 return s;
741
742 return 0;
743 }
744
745 //
746 // Take an IP address in HOST byte order and
747 // add it to the sessionid by IP cache.
748 //
749 // (It's actually cached in network order)
750 //
751 static void cache_ipmap(in_addr_t ip, int s)
752 {
753 in_addr_t nip = htonl(ip); // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
754 uint8_t *a = (uint8_t *) &nip;
755 uint8_t **d = (uint8_t **) ip_hash;
756 int i;
757
758 for (i = 0; i < 3; i++)
759 {
760 if (!d[(size_t) a[i]])
761 {
762 if (!(d[(size_t) a[i]] = calloc(256, sizeof(void *))))
763 return;
764 }
765
766 d = (uint8_t **) d[(size_t) a[i]];
767 }
768
769 d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
770
771 if (s > 0)
772 LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
773
774 else if (s == 0)
775 LOG(4, 0, 0, "Un-caching ip address %s\n", fmtaddr(nip, 0));
776 // else a map to an ip pool index.
777 }
778
779 static void uncache_ipmap(in_addr_t ip)
780 {
781 cache_ipmap(ip, 0); // Assign it to the NULL session.
782 }
783
784 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
785 {
786 int i;
787 int bytes;
788 struct ipv6radix *curnode;
789 char ipv6addr[INET6_ADDRSTRLEN];
790
791 curnode = &ipv6_hash[ip.s6_addr[0]];
792
793 bytes = prefixlen >> 3;
794 i = 1;
795 while (i < bytes) {
796 if (curnode->branch == NULL)
797 {
798 if (!(curnode->branch = calloc(256,
799 sizeof (struct ipv6radix))))
800 return;
801 }
802 curnode = &curnode->branch[ip.s6_addr[i]];
803 i++;
804 }
805
806 curnode->sess = s;
807
808 if (s > 0)
809 LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
810 inet_ntop(AF_INET6, &ip, ipv6addr,
811 INET6_ADDRSTRLEN),
812 prefixlen);
813 else if (s == 0)
814 LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
815 inet_ntop(AF_INET6, &ip, ipv6addr,
816 INET6_ADDRSTRLEN),
817 prefixlen);
818 }
819
820 //
821 // CLI list to dump current ipcache.
822 //
823 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
824 {
825 char **d = (char **) ip_hash, **e, **f, **g;
826 int i, j, k, l;
827 int count = 0;
828
829 if (CLI_HELP_REQUESTED)
830 return CLI_HELP_NO_ARGS;
831
832 cli_print(cli, "%7s %s", "Sess#", "IP Address");
833
834 for (i = 0; i < 256; ++i)
835 {
836 if (!d[i])
837 continue;
838 e = (char **) d[i];
839 for (j = 0; j < 256; ++j)
840 {
841 if (!e[j])
842 continue;
843 f = (char **) e[j];
844 for (k = 0; k < 256; ++k)
845 {
846 if (!f[k])
847 continue;
848 g = (char **)f[k];
849 for (l = 0; l < 256; ++l)
850 {
851 if (!g[l])
852 continue;
853 cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
854 ++count;
855 }
856 }
857 }
858 }
859 cli_print(cli, "%d entries in cache", count);
860 return CLI_OK;
861 }
862
863
864 // Find session by username, 0 for not found
865 // walled garden users aren't authenticated, so the username is
866 // reasonably useless. Ignore them to avoid incorrect actions
867 //
868 // This is VERY inefficent. Don't call it often. :)
869 //
870 sessionidt sessionbyuser(char *username)
871 {
872 int s;
873 CSTAT(sessionbyuser);
874
875 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
876 {
877 if (!session[s].opened)
878 continue;
879
880 if (session[s].walled_garden)
881 continue; // Skip walled garden users.
882
883 if (!strncmp(session[s].user, username, 128))
884 return s;
885
886 }
887 return 0; // Not found.
888 }
889
890 void send_garp(in_addr_t ip)
891 {
892 int s;
893 struct ifreq ifr;
894 uint8_t mac[6];
895
896 s = socket(PF_INET, SOCK_DGRAM, 0);
897 if (s < 0)
898 {
899 LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
900 return;
901 }
902 memset(&ifr, 0, sizeof(ifr));
903 strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
904 if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
905 {
906 LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
907 close(s);
908 return;
909 }
910 memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
911 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
912 {
913 LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
914 close(s);
915 return;
916 }
917 close(s);
918 sendarp(ifr.ifr_ifindex, mac, ip);
919 }
920
921 static sessiont *sessiontbysessionidt(sessionidt s)
922 {
923 if (!s || s >= MAXSESSION) return NULL;
924 return &session[s];
925 }
926
927 static sessionidt sessionidtbysessiont(sessiont *s)
928 {
929 sessionidt val = s-session;
930 if (s < session || val >= MAXSESSION) return 0;
931 return val;
932 }
933
934 // actually send a control message for a specific tunnel
935 void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
936 {
937 struct sockaddr_in addr;
938
939 CSTAT(tunnelsend);
940
941 if (!t)
942 {
943 static int backtrace_count = 0;
944 LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
945 STAT(tunnel_tx_errors);
946 log_backtrace(backtrace_count, 5)
947 return;
948 }
949
950 if (!tunnel[t].ip)
951 {
952 static int backtrace_count = 0;
953 LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
954 log_backtrace(backtrace_count, 5)
955 STAT(tunnel_tx_errors);
956 return;
957 }
958
959 memset(&addr, 0, sizeof(addr));
960 addr.sin_family = AF_INET;
961 *(uint32_t *) & addr.sin_addr = htonl(tunnel[t].ip);
962 addr.sin_port = htons(tunnel[t].port);
963
964 // sequence expected, if sequence in message
965 if (*buf & 0x08) *(uint16_t *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
966
967 // If this is a control message, deal with retries
968 if (*buf & 0x80)
969 {
970 tunnel[t].last = time_now; // control message sent
971 tunnel[t].retry = backoff(tunnel[t].try); // when to resend
972 if (tunnel[t].try)
973 {
974 STAT(tunnel_retries);
975 LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
976 }
977 }
978
979 if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
980 {
981 LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
982 strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
983 STAT(tunnel_tx_errors);
984 return;
985 }
986
987 LOG_HEX(5, "Send Tunnel Data", buf, l);
988 STAT(tunnel_tx_packets);
989 INC_STAT(tunnel_tx_bytes, l);
990 }
991
992 //
993 // Tiny helper function to write data to
994 // the 'tun' device.
995 //
996 int tun_write(uint8_t * data, int size)
997 {
998 return write(tunfd, data, size);
999 }
1000
1001 // adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
1002 void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
1003 {
1004 int d = (tcp[12] >> 4) * 4;
1005 uint8_t *mss = 0;
1006 uint8_t *opts;
1007 uint8_t *data;
1008 uint16_t orig;
1009 uint32_t sum;
1010
1011 if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
1012 return;
1013
1014 if (tcp + d > buf + len) // short?
1015 return;
1016
1017 opts = tcp + 20;
1018 data = tcp + d;
1019
1020 while (opts < data)
1021 {
1022 if (*opts == 2 && opts[1] == 4) // mss option (2), length 4
1023 {
1024 mss = opts + 2;
1025 if (mss + 2 > data) return; // short?
1026 break;
1027 }
1028
1029 if (*opts == 0) return; // end of options
1030 if (*opts == 1 || !opts[1]) // no op (one byte), or no length (prevent loop)
1031 opts++;
1032 else
1033 opts += opts[1]; // skip over option
1034 }
1035
1036 if (!mss) return; // not found
1037 orig = ntohs(*(uint16_t *) mss);
1038
1039 if (orig <= MSS) return; // mss OK
1040
1041 LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s: adjusted mss from %u to %u\n",
1042 fmtaddr(*(in_addr_t *) (buf + 12), 0), ntohs(*(uint16_t *) tcp),
1043 fmtaddr(*(in_addr_t *) (buf + 16), 1), ntohs(*(uint16_t *) (tcp + 2)),
1044 (tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "", orig, MSS);
1045
1046 // set mss
1047 *(int16_t *) mss = htons(MSS);
1048
1049 // adjust checksum (see rfc1141)
1050 sum = orig + (~MSS & 0xffff);
1051 sum += ntohs(*(uint16_t *) (tcp + 16));
1052 sum = (sum & 0xffff) + (sum >> 16);
1053 *(uint16_t *) (tcp + 16) = htons(sum + (sum >> 16));
1054 }
1055
1056 // process outgoing (to tunnel) IP
1057 //
1058 static void processipout(uint8_t *buf, int len)
1059 {
1060 sessionidt s;
1061 sessiont *sp;
1062 tunnelidt t;
1063 in_addr_t ip;
1064
1065 uint8_t *data = buf; // Keep a copy of the originals.
1066 int size = len;
1067
1068 uint8_t b[MAXETHER + 20];
1069
1070 CSTAT(processipout);
1071
1072 if (len < MIN_IP_SIZE)
1073 {
1074 LOG(1, 0, 0, "Short IP, %d bytes\n", len);
1075 STAT(tun_rx_errors);
1076 return;
1077 }
1078 if (len >= MAXETHER)
1079 {
1080 LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
1081 STAT(tun_rx_errors);
1082 return;
1083 }
1084
1085 // Skip the tun header
1086 buf += 4;
1087 len -= 4;
1088
1089 // Got an IP header now
1090 if (*(uint8_t *)(buf) >> 4 != 4)
1091 {
1092 LOG(1, 0, 0, "IP: Don't understand anything except IPv4\n");
1093 return;
1094 }
1095
1096 ip = *(uint32_t *)(buf + 16);
1097 if (!(s = sessionbyip(ip)))
1098 {
1099 // Is this a packet for a session that doesn't exist?
1100 static int rate = 0; // Number of ICMP packets we've sent this second.
1101 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1102
1103 if (last != time_now)
1104 {
1105 last = time_now;
1106 rate = 0;
1107 }
1108
1109 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1110 {
1111 LOG(4, 0, 0, "IP: Sending ICMP host unreachable to %s\n", fmtaddr(*(in_addr_t *)(buf + 12), 0));
1112 host_unreachable(*(in_addr_t *)(buf + 12), *(uint16_t *)(buf + 4),
1113 config->bind_address ? config->bind_address : my_address, buf, len);
1114 }
1115 return;
1116 }
1117 t = session[s].tunnel;
1118 sp = &session[s];
1119
1120 // DoS prevention: enforce a maximum number of packets per 0.1s for a session
1121 if (config->max_packets > 0)
1122 {
1123 if (sess_local[s].last_packet_out == TIME)
1124 {
1125 int max = config->max_packets;
1126
1127 // All packets for throttled sessions are handled by the
1128 // master, so further limit by using the throttle rate.
1129 // A bit of a kludge, since throttle rate is in kbps,
1130 // but should still be generous given our average DSL
1131 // packet size is 200 bytes: a limit of 28kbps equates
1132 // to around 180 packets per second.
1133 if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
1134 max = sp->throttle_out;
1135
1136 if (++sess_local[s].packets_out > max)
1137 {
1138 sess_local[s].packets_dropped++;
1139 return;
1140 }
1141 }
1142 else
1143 {
1144 if (sess_local[s].packets_dropped)
1145 {
1146 INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
1147 LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
1148 sess_local[s].packets_dropped, sess_local[s].packets_out,
1149 fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
1150 sp->user);
1151 }
1152
1153 sess_local[s].last_packet_out = TIME;
1154 sess_local[s].packets_out = 1;
1155 sess_local[s].packets_dropped = 0;
1156 }
1157 }
1158
1159 // run access-list if any
1160 if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
1161 return;
1162
1163 // adjust MSS on SYN and SYN,ACK packets with options
1164 if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
1165 {
1166 int ihl = (buf[0] & 0xf) * 4; // length of IP header
1167 if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
1168 adjust_tcp_mss(s, t, buf, len, buf + ihl);
1169 }
1170
1171 if (sp->tbf_out)
1172 {
1173 // Are we throttling this session?
1174 if (config->cluster_iam_master)
1175 tbf_queue_packet(sp->tbf_out, data, size);
1176 else
1177 master_throttle_packet(sp->tbf_out, data, size);
1178 return;
1179 }
1180
1181 if (sp->walled_garden && !config->cluster_iam_master)
1182 {
1183 // We are walled-gardening this
1184 master_garden_packet(s, data, size);
1185 return;
1186 }
1187
1188 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1189
1190 // Add on L2TP header
1191 {
1192 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
1193 if (!p) return;
1194 tunnelsend(b, len + (p-b), t); // send it...
1195 }
1196
1197 // Snooping this session, send it to intercept box
1198 if (sp->snoop_ip && sp->snoop_port)
1199 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1200
1201 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1202 sp->cout_delta += len;
1203 sp->pout++;
1204 udp_tx += len;
1205
1206 sess_local[s].cout += len; // To send to master..
1207 sess_local[s].pout++;
1208 }
1209
1210 // process outgoing (to tunnel) IPv6
1211 //
1212 static void processipv6out(uint8_t * buf, int len)
1213 {
1214 sessionidt s;
1215 sessiont *sp;
1216 tunnelidt t;
1217 in_addr_t ip;
1218 struct in6_addr ip6;
1219
1220 uint8_t *data = buf; // Keep a copy of the originals.
1221 int size = len;
1222
1223 uint8_t b[MAXETHER + 20];
1224
1225 CSTAT(processipv6out);
1226
1227 if (len < MIN_IP_SIZE)
1228 {
1229 LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
1230 STAT(tunnel_tx_errors);
1231 return;
1232 }
1233 if (len >= MAXETHER)
1234 {
1235 LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
1236 STAT(tunnel_tx_errors);
1237 return;
1238 }
1239
1240 // Skip the tun header
1241 buf += 4;
1242 len -= 4;
1243
1244 // Got an IP header now
1245 if (*(uint8_t *)(buf) >> 4 != 6)
1246 {
1247 LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
1248 return;
1249 }
1250
1251 ip6 = *(struct in6_addr *)(buf+24);
1252 s = sessionbyipv6(ip6);
1253
1254 if (s == 0)
1255 {
1256 ip = *(uint32_t *)(buf + 32);
1257 s = sessionbyip(ip);
1258 }
1259
1260 if (s == 0)
1261 {
1262 // Is this a packet for a session that doesn't exist?
1263 static int rate = 0; // Number of ICMP packets we've sent this second.
1264 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1265
1266 if (last != time_now)
1267 {
1268 last = time_now;
1269 rate = 0;
1270 }
1271
1272 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1273 {
1274 // FIXME: Should send icmp6 host unreachable
1275 }
1276 return;
1277 }
1278 t = session[s].tunnel;
1279 sp = &session[s];
1280
1281 // FIXME: add DoS prevention/filters?
1282
1283 if (sp->tbf_out)
1284 {
1285 // Are we throttling this session?
1286 if (config->cluster_iam_master)
1287 tbf_queue_packet(sp->tbf_out, data, size);
1288 else
1289 master_throttle_packet(sp->tbf_out, data, size);
1290 return;
1291 }
1292 else if (sp->walled_garden && !config->cluster_iam_master)
1293 {
1294 // We are walled-gardening this
1295 master_garden_packet(s, data, size);
1296 return;
1297 }
1298
1299 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1300
1301 // Add on L2TP header
1302 {
1303 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIPV6);
1304 if (!p) return;
1305 tunnelsend(b, len + (p-b), t); // send it...
1306 }
1307
1308 // Snooping this session, send it to intercept box
1309 if (sp->snoop_ip && sp->snoop_port)
1310 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1311
1312 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1313 sp->cout_delta += len;
1314 sp->pout++;
1315 udp_tx += len;
1316
1317 sess_local[s].cout += len; // To send to master..
1318 sess_local[s].pout++;
1319 }
1320
1321 //
1322 // Helper routine for the TBF filters.
1323 // Used to send queued data in to the user!
1324 //
1325 static void send_ipout(sessionidt s, uint8_t *buf, int len)
1326 {
1327 sessiont *sp;
1328 tunnelidt t;
1329 in_addr_t ip;
1330
1331 uint8_t b[MAXETHER + 20];
1332
1333 if (len < 0 || len > MAXETHER)
1334 {
1335 LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
1336 return;
1337 }
1338
1339 // Skip the tun header
1340 buf += 4;
1341 len -= 4;
1342
1343 ip = *(in_addr_t *)(buf + 16);
1344
1345 if (!session[s].ip)
1346 return;
1347
1348 t = session[s].tunnel;
1349 sp = &session[s];
1350
1351 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1352
1353 // Add on L2TP header
1354 {
1355 uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
1356 if (!p) return;
1357 tunnelsend(b, len + (p-b), t); // send it...
1358 }
1359
1360 // Snooping this session.
1361 if (sp->snoop_ip && sp->snoop_port)
1362 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1363
1364 increment_counter(&sp->cout, &sp->cout_wrap, len); // byte count
1365 sp->cout_delta += len;
1366 sp->pout++;
1367 udp_tx += len;
1368
1369 sess_local[s].cout += len; // To send to master..
1370 sess_local[s].pout++;
1371 }
1372
1373 // add an AVP (16 bit)
1374 static void control16(controlt * c, uint16_t avp, uint16_t val, uint8_t m)
1375 {
1376 uint16_t l = (m ? 0x8008 : 0x0008);
1377 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1378 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1379 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1380 *(uint16_t *) (c->buf + c->length + 6) = htons(val);
1381 c->length += 8;
1382 }
1383
1384 // add an AVP (32 bit)
1385 static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
1386 {
1387 uint16_t l = (m ? 0x800A : 0x000A);
1388 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1389 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1390 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1391 *(uint32_t *) (c->buf + c->length + 6) = htonl(val);
1392 c->length += 10;
1393 }
1394
1395 // add an AVP (string)
1396 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
1397 {
1398 uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
1399 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1400 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1401 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1402 memcpy(c->buf + c->length + 6, val, strlen(val));
1403 c->length += 6 + strlen(val);
1404 }
1405
1406 // add a binary AVP
1407 static void controlb(controlt * c, uint16_t avp, uint8_t *val, unsigned int len, uint8_t m)
1408 {
1409 uint16_t l = ((m ? 0x8000 : 0) + len + 6);
1410 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1411 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1412 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1413 memcpy(c->buf + c->length + 6, val, len);
1414 c->length += 6 + len;
1415 }
1416
1417 // new control connection
1418 static controlt *controlnew(uint16_t mtype)
1419 {
1420 controlt *c;
1421 if (!controlfree)
1422 c = malloc(sizeof(controlt));
1423 else
1424 {
1425 c = controlfree;
1426 controlfree = c->next;
1427 }
1428 assert(c);
1429 c->next = 0;
1430 *(uint16_t *) (c->buf + 0) = htons(0xC802); // flags/ver
1431 c->length = 12;
1432 control16(c, 0, mtype, 1);
1433 return c;
1434 }
1435
1436 // send zero block if nothing is waiting
1437 // (ZLB send).
1438 static void controlnull(tunnelidt t)
1439 {
1440 uint8_t buf[12];
1441 if (tunnel[t].controlc) // Messages queued; They will carry the ack.
1442 return;
1443
1444 *(uint16_t *) (buf + 0) = htons(0xC802); // flags/ver
1445 *(uint16_t *) (buf + 2) = htons(12); // length
1446 *(uint16_t *) (buf + 4) = htons(tunnel[t].far); // tunnel
1447 *(uint16_t *) (buf + 6) = htons(0); // session
1448 *(uint16_t *) (buf + 8) = htons(tunnel[t].ns); // sequence
1449 *(uint16_t *) (buf + 10) = htons(tunnel[t].nr); // sequence
1450 tunnelsend(buf, 12, t);
1451 }
1452
1453 // add a control message to a tunnel, and send if within window
1454 static void controladd(controlt *c, sessionidt far, tunnelidt t)
1455 {
1456 *(uint16_t *) (c->buf + 2) = htons(c->length); // length
1457 *(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
1458 *(uint16_t *) (c->buf + 6) = htons(far); // session
1459 *(uint16_t *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
1460 tunnel[t].ns++; // advance sequence
1461 // link in message in to queue
1462 if (tunnel[t].controlc)
1463 tunnel[t].controle->next = c;
1464 else
1465 tunnel[t].controls = c;
1466
1467 tunnel[t].controle = c;
1468 tunnel[t].controlc++;
1469
1470 // send now if space in window
1471 if (tunnel[t].controlc <= tunnel[t].window)
1472 {
1473 tunnel[t].try = 0; // first send
1474 tunnelsend(c->buf, c->length, t);
1475 }
1476 }
1477
1478 //
1479 // Throttle or Unthrottle a session
1480 //
1481 // Throttle the data from/to through a session to no more than
1482 // 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
1483 // user).
1484 //
1485 // If either value is -1, the current value is retained for that
1486 // direction.
1487 //
1488 void throttle_session(sessionidt s, int rate_in, int rate_out)
1489 {
1490 if (!session[s].opened)
1491 return; // No-one home.
1492
1493 if (!*session[s].user)
1494 return; // User not logged in
1495
1496 if (rate_in >= 0)
1497 {
1498 int bytes = rate_in * 1024 / 8; // kbits to bytes
1499 if (session[s].tbf_in)
1500 free_tbf(session[s].tbf_in);
1501
1502 if (rate_in > 0)
1503 session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
1504 else
1505 session[s].tbf_in = 0;
1506
1507 session[s].throttle_in = rate_in;
1508 }
1509
1510 if (rate_out >= 0)
1511 {
1512 int bytes = rate_out * 1024 / 8;
1513 if (session[s].tbf_out)
1514 free_tbf(session[s].tbf_out);
1515
1516 if (rate_out > 0)
1517 session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
1518 else
1519 session[s].tbf_out = 0;
1520
1521 session[s].throttle_out = rate_out;
1522 }
1523 }
1524
1525 // add/remove filters from session (-1 = no change)
1526 void filter_session(sessionidt s, int filter_in, int filter_out)
1527 {
1528 if (!session[s].opened)
1529 return; // No-one home.
1530
1531 if (!*session[s].user)
1532 return; // User not logged in
1533
1534 // paranoia
1535 if (filter_in > MAXFILTER) filter_in = -1;
1536 if (filter_out > MAXFILTER) filter_out = -1;
1537 if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
1538 if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
1539
1540 if (filter_in >= 0)
1541 {
1542 if (session[s].filter_in)
1543 ip_filters[session[s].filter_in - 1].used--;
1544
1545 if (filter_in > 0)
1546 ip_filters[filter_in - 1].used++;
1547
1548 session[s].filter_in = filter_in;
1549 }
1550
1551 if (filter_out >= 0)
1552 {
1553 if (session[s].filter_out)
1554 ip_filters[session[s].filter_out - 1].used--;
1555
1556 if (filter_out > 0)
1557 ip_filters[filter_out - 1].used++;
1558
1559 session[s].filter_out = filter_out;
1560 }
1561 }
1562
1563 // start tidy shutdown of session
1564 void sessionshutdown(sessionidt s, char *reason, int result, int error)
1565 {
1566 int walled_garden = session[s].walled_garden;
1567
1568
1569 CSTAT(sessionshutdown);
1570
1571 if (!session[s].opened)
1572 {
1573 LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
1574 return; // not a live session
1575 }
1576
1577 if (!session[s].die)
1578 {
1579 struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
1580 LOG(2, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
1581 run_plugins(PLUGIN_KILL_SESSION, &data);
1582 }
1583
1584 if (session[s].ip && !walled_garden && !session[s].die)
1585 {
1586 // RADIUS Stop message
1587 uint16_t r = radiusnew(s);
1588 if (r)
1589 {
1590 // stop, if not already trying
1591 if (radius[r].state != RADIUSSTOP)
1592 radiussend(r, RADIUSSTOP);
1593 }
1594 else
1595 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
1596
1597 // Save counters to dump to accounting file
1598 if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
1599 memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
1600 }
1601
1602 if (session[s].ip)
1603 { // IP allocated, clear and unroute
1604 int r;
1605 int routed = 0;
1606 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
1607 {
1608 if ((session[s].ip & session[s].route[r].mask) ==
1609 (session[s].route[r].ip & session[s].route[r].mask))
1610 routed++;
1611
1612 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
1613 session[s].route[r].ip = 0;
1614 }
1615
1616 if (session[s].ip_pool_index == -1) // static ip
1617 {
1618 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
1619 session[s].ip = 0;
1620 }
1621 else
1622 free_ip_address(s);
1623
1624 // unroute IPv6, if setup
1625 if (session[s].ppp.ipv6cp == Opened && session[s].ipv6prefixlen)
1626 route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
1627 }
1628
1629 if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
1630 throttle_session(s, 0, 0);
1631
1632 if (result)
1633 { // Send CDN
1634 controlt *c = controlnew(14); // sending CDN
1635 if (error)
1636 {
1637 uint8_t buf[4];
1638 *(uint16_t *) buf = htons(result);
1639 *(uint16_t *) (buf+2) = htons(error);
1640 controlb(c, 1, buf, 4, 1);
1641 }
1642 else
1643 control16(c, 1, result, 1);
1644
1645 control16(c, 14, s, 1); // assigned session (our end)
1646 controladd(c, session[s].far, session[s].tunnel); // send the message
1647 }
1648
1649 if (!session[s].die)
1650 session[s].die = TIME + 150; // Clean up in 15 seconds
1651
1652 // update filter refcounts
1653 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1654 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1655
1656 // clear PPP state
1657 memset(&session[s].ppp, 0, sizeof(session[s].ppp));
1658 sess_local[s].lcp.restart = 0;
1659 sess_local[s].ipcp.restart = 0;
1660 sess_local[s].ipv6cp.restart = 0;
1661 sess_local[s].ccp.restart = 0;
1662
1663 cluster_send_session(s);
1664 }
1665
1666 void sendipcp(sessionidt s, tunnelidt t)
1667 {
1668 uint8_t buf[MAXETHER];
1669 uint8_t *q;
1670
1671 CSTAT(sendipcp);
1672 LOG(3, s, t, "IPCP: send ConfigReq\n");
1673
1674 if (!session[s].unique_id)
1675 {
1676 if (!++last_id) ++last_id; // skip zero
1677 session[s].unique_id = last_id;
1678 }
1679
1680 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP);
1681 if (!q) return;
1682
1683 *q = ConfigReq;
1684 q[1] = session[s].unique_id & 0xf; // ID, dont care, we only send one type of request
1685 *(uint16_t *) (q + 2) = htons(10); // packet length
1686 q[4] = 3; // ip address option
1687 q[5] = 6; // option length
1688 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1689 config->bind_address ? config->bind_address :
1690 my_address; // send my IP
1691
1692 tunnelsend(buf, 10 + (q - buf), t); // send it
1693 restart_timer(s, ipcp);
1694 }
1695
1696 void sendipv6cp(sessionidt s, tunnelidt t)
1697 {
1698 uint8_t buf[MAXETHER];
1699 uint8_t *q;
1700
1701 CSTAT(sendipv6cp);
1702 LOG(3, s, t, "IPV6CP: send ConfigReq\n");
1703
1704 q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP);
1705 if (!q) return;
1706
1707 *q = ConfigReq;
1708 q[1] = session[s].unique_id & 0xf; // ID, don't care, we
1709 // only send one type
1710 // of request
1711 *(uint16_t *) (q + 2) = htons(14);
1712 q[4] = 1; // interface identifier option
1713 q[5] = 10; // option length
1714 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1715 *(uint32_t *) (q + 10) = 0;
1716 q[13] = 1;
1717
1718 tunnelsend(buf, 14 + (q - buf), t); // send it
1719 restart_timer(s, ipv6cp);
1720 }
1721
1722 static void sessionclear(sessionidt s)
1723 {
1724 memset(&session[s], 0, sizeof(session[s]));
1725 memset(&sess_local[s], 0, sizeof(sess_local[s]));
1726 memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
1727
1728 session[s].tunnel = T_FREE; // Mark it as free.
1729 session[s].next = sessionfree;
1730 sessionfree = s;
1731 }
1732
1733 // kill a session now
1734 void sessionkill(sessionidt s, char *reason)
1735 {
1736
1737 CSTAT(sessionkill);
1738
1739 if (!session[s].opened) // not alive
1740 return;
1741
1742 if (session[s].next)
1743 {
1744 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1745 return;
1746 }
1747
1748 session[s].die = TIME;
1749 sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
1750 if (sess_local[s].radius)
1751 radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
1752
1753 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1754 sessionclear(s);
1755 cluster_send_session(s);
1756 }
1757
1758 static void tunnelclear(tunnelidt t)
1759 {
1760 if (!t) return;
1761 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1762 tunnel[t].state = TUNNELFREE;
1763 }
1764
1765 // kill a tunnel now
1766 static void tunnelkill(tunnelidt t, char *reason)
1767 {
1768 sessionidt s;
1769 controlt *c;
1770
1771 CSTAT(tunnelkill);
1772
1773 tunnel[t].state = TUNNELDIE;
1774
1775 // free control messages
1776 while ((c = tunnel[t].controls))
1777 {
1778 controlt * n = c->next;
1779 tunnel[t].controls = n;
1780 tunnel[t].controlc--;
1781 c->next = controlfree;
1782 controlfree = c;
1783 }
1784 // kill sessions
1785 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1786 if (session[s].tunnel == t)
1787 sessionkill(s, reason);
1788
1789 // free tunnel
1790 tunnelclear(t);
1791 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1792 cli_tunnel_actions[t].action = 0;
1793 cluster_send_tunnel(t);
1794 }
1795
1796 // shut down a tunnel cleanly
1797 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1798 {
1799 sessionidt s;
1800
1801 CSTAT(tunnelshutdown);
1802
1803 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1804 {
1805 // never set up, can immediately kill
1806 tunnelkill(t, reason);
1807 return;
1808 }
1809 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1810
1811 // close session
1812 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1813 if (session[s].tunnel == t)
1814 sessionshutdown(s, reason, 0, 0);
1815
1816 tunnel[t].state = TUNNELDIE;
1817 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1818 cluster_send_tunnel(t);
1819 // TBA - should we wait for sessions to stop?
1820 if (result)
1821 {
1822 controlt *c = controlnew(4); // sending StopCCN
1823 if (error)
1824 {
1825 uint8_t buf[64];
1826 int l = 4;
1827 *(uint16_t *) buf = htons(result);
1828 *(uint16_t *) (buf+2) = htons(error);
1829 if (msg)
1830 {
1831 int m = strlen(msg);
1832 if (m + 4 > sizeof(buf))
1833 m = sizeof(buf) - 4;
1834
1835 memcpy(buf+4, msg, m);
1836 l += m;
1837 }
1838
1839 controlb(c, 1, buf, l, 1);
1840 }
1841 else
1842 control16(c, 1, result, 1);
1843
1844 control16(c, 9, t, 1); // assigned tunnel (our end)
1845 controladd(c, 0, t); // send the message
1846 }
1847 }
1848
1849 // read and process packet on tunnel (UDP)
1850 void processudp(uint8_t *buf, int len, struct sockaddr_in *addr)
1851 {
1852 uint8_t *chapresponse = NULL;
1853 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1854 uint8_t *p = buf + 2;
1855
1856
1857 CSTAT(processudp);
1858
1859 udp_rx += len;
1860 udp_rx_pkt++;
1861 LOG_HEX(5, "UDP Data", buf, len);
1862 STAT(tunnel_rx_packets);
1863 INC_STAT(tunnel_rx_bytes, len);
1864 if (len < 6)
1865 {
1866 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1867 STAT(tunnel_rx_errors);
1868 return;
1869 }
1870 if ((buf[1] & 0x0F) != 2)
1871 {
1872 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1873 STAT(tunnel_rx_errors);
1874 return;
1875 }
1876 if (*buf & 0x40)
1877 { // length
1878 l = ntohs(*(uint16_t *) p);
1879 p += 2;
1880 }
1881 t = ntohs(*(uint16_t *) p);
1882 p += 2;
1883 s = ntohs(*(uint16_t *) p);
1884 p += 2;
1885 if (s >= MAXSESSION)
1886 {
1887 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1888 STAT(tunnel_rx_errors);
1889 return;
1890 }
1891 if (t >= MAXTUNNEL)
1892 {
1893 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1894 STAT(tunnel_rx_errors);
1895 return;
1896 }
1897 if (*buf & 0x08)
1898 { // ns/nr
1899 ns = ntohs(*(uint16_t *) p);
1900 p += 2;
1901 nr = ntohs(*(uint16_t *) p);
1902 p += 2;
1903 }
1904 if (*buf & 0x02)
1905 { // offset
1906 uint16_t o = ntohs(*(uint16_t *) p);
1907 p += o + 2;
1908 }
1909 if ((p - buf) > l)
1910 {
1911 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1912 STAT(tunnel_rx_errors);
1913 return;
1914 }
1915 l -= (p - buf);
1916
1917 // used to time out old tunnels
1918 if (t && tunnel[t].state == TUNNELOPEN)
1919 tunnel[t].lastrec = time_now;
1920
1921 if (*buf & 0x80)
1922 { // control
1923 uint16_t message = 0xFFFF; // message type
1924 uint8_t fatal = 0;
1925 uint8_t mandatory = 0;
1926 uint16_t asession = 0; // assigned session
1927 uint32_t amagic = 0; // magic number
1928 uint8_t aflags = 0; // flags from last LCF
1929 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1930 char called[MAXTEL] = ""; // called number
1931 char calling[MAXTEL] = ""; // calling number
1932
1933 if (!config->cluster_iam_master)
1934 {
1935 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1936 return;
1937 }
1938
1939 // control messages must have bits 0x80|0x40|0x08
1940 // (type, length and sequence) set, and bits 0x02|0x01
1941 // (offset and priority) clear
1942 if ((*buf & 0xCB) != 0xC8)
1943 {
1944 LOG(1, s, t, "Bad control header %02X\n", *buf);
1945 STAT(tunnel_rx_errors);
1946 return;
1947 }
1948
1949 // check for duplicate tunnel open message
1950 if (!t && ns == 0)
1951 {
1952 int i;
1953
1954 //
1955 // Is this a duplicate of the first packet? (SCCRQ)
1956 //
1957 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1958 {
1959 if (tunnel[i].state != TUNNELOPENING ||
1960 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1961 tunnel[i].port != ntohs(addr->sin_port) )
1962 continue;
1963 t = i;
1964 LOG(3, s, t, "Duplicate SCCRQ?\n");
1965 break;
1966 }
1967 }
1968
1969 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1970 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1971
1972 // if no tunnel specified, assign one
1973 if (!t)
1974 {
1975 if (!(t = new_tunnel()))
1976 {
1977 LOG(1, 0, 0, "No more tunnels\n");
1978 STAT(tunnel_overflow);
1979 return;
1980 }
1981 tunnelclear(t);
1982 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1983 tunnel[t].port = ntohs(addr->sin_port);
1984 tunnel[t].window = 4; // default window
1985 STAT(tunnel_created);
1986 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1987 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1988 }
1989
1990 // If the 'ns' just received is not the 'nr' we're
1991 // expecting, just send an ack and drop it.
1992 //
1993 // if 'ns' is less, then we got a retransmitted packet.
1994 // if 'ns' is greater than missed a packet. Either way
1995 // we should ignore it.
1996 if (ns != tunnel[t].nr)
1997 {
1998 // is this the sequence we were expecting?
1999 STAT(tunnel_rx_errors);
2000 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
2001 t, ns, tunnel[t].nr);
2002
2003 if (l) // Is this not a ZLB?
2004 controlnull(t);
2005 return;
2006 }
2007
2008 // check sequence of this message
2009 {
2010 int skip = tunnel[t].window; // track how many in-window packets are still in queue
2011 // some to clear maybe?
2012 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
2013 {
2014 controlt *c = tunnel[t].controls;
2015 tunnel[t].controls = c->next;
2016 tunnel[t].controlc--;
2017 c->next = controlfree;
2018 controlfree = c;
2019 skip--;
2020 tunnel[t].try = 0; // we have progress
2021 }
2022
2023 // receiver advance (do here so quoted correctly in any sends below)
2024 if (l) tunnel[t].nr = (ns + 1);
2025 if (skip < 0) skip = 0;
2026 if (skip < tunnel[t].controlc)
2027 {
2028 // some control packets can now be sent that were previous stuck out of window
2029 int tosend = tunnel[t].window - skip;
2030 controlt *c = tunnel[t].controls;
2031 while (c && skip)
2032 {
2033 c = c->next;
2034 skip--;
2035 }
2036 while (c && tosend)
2037 {
2038 tunnel[t].try = 0; // first send
2039 tunnelsend(c->buf, c->length, t);
2040 c = c->next;
2041 tosend--;
2042 }
2043 }
2044 if (!tunnel[t].controlc)
2045 tunnel[t].retry = 0; // caught up
2046 }
2047 if (l)
2048 { // if not a null message
2049 int result = 0;
2050 int error = 0;
2051 char *msg = 0;
2052
2053 // process AVPs
2054 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
2055 {
2056 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
2057 uint8_t *b = p;
2058 uint8_t flags = *p;
2059 uint16_t mtype;
2060 if (n > l)
2061 {
2062 LOG(1, s, t, "Invalid length in AVP\n");
2063 STAT(tunnel_rx_errors);
2064 return;
2065 }
2066 p += n; // next
2067 l -= n;
2068 if (flags & 0x3C) // reserved bits, should be clear
2069 {
2070 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
2071 fatal = flags;
2072 result = 2; // general error
2073 error = 3; // reserved field non-zero
2074 msg = 0;
2075 continue; // next
2076 }
2077 b += 2;
2078 if (*(uint16_t *) (b))
2079 {
2080 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
2081 fatal = flags;
2082 result = 2; // general error
2083 error = 6; // generic vendor-specific error
2084 msg = "unsupported vendor-specific";
2085 continue; // next
2086 }
2087 b += 2;
2088 mtype = ntohs(*(uint16_t *) (b));
2089 b += 2;
2090 n -= 6;
2091
2092 if (flags & 0x40)
2093 {
2094 uint16_t orig_len;
2095
2096 // handle hidden AVPs
2097 if (!*config->l2tp_secret)
2098 {
2099 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
2100 fatal = flags;
2101 result = 2; // general error
2102 error = 6; // generic vendor-specific error
2103 msg = "secret not specified";
2104 continue;
2105 }
2106 if (!session[s].random_vector_length)
2107 {
2108 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
2109 fatal = flags;
2110 result = 2; // general error
2111 error = 6; // generic
2112 msg = "no random vector";
2113 continue;
2114 }
2115 if (n < 8)
2116 {
2117 LOG(2, s, t, "Short hidden AVP.\n");
2118 fatal = flags;
2119 result = 2; // general error
2120 error = 2; // length is wrong
2121 msg = 0;
2122 continue;
2123 }
2124
2125 // Unhide the AVP
2126 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
2127
2128 orig_len = ntohs(*(uint16_t *) b);
2129 if (orig_len > n + 2)
2130 {
2131 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
2132 orig_len, n);
2133
2134 fatal = flags;
2135 result = 2; // general error
2136 error = 2; // length is wrong
2137 msg = 0;
2138 continue;
2139 }
2140
2141 b += 2;
2142 n = orig_len;
2143 }
2144
2145 LOG(4, s, t, " AVP %d (%s) len %d%s%s\n", mtype, l2tp_avp_name(mtype), n,
2146 flags & 0x40 ? ", hidden" : "", flags & 0x80 ? ", mandatory" : "");
2147
2148 switch (mtype)
2149 {
2150 case 0: // message type
2151 message = ntohs(*(uint16_t *) b);
2152 mandatory = flags & 0x80;
2153 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_code(message));
2154 break;
2155 case 1: // result code
2156 {
2157 uint16_t rescode = ntohs(*(uint16_t *) b);
2158 const char* resdesc = "(unknown)";
2159 if (message == 4)
2160 { /* StopCCN */
2161 resdesc = l2tp_stopccn_result_code(rescode);
2162 }
2163 else if (message == 14)
2164 { /* CDN */
2165 resdesc = l2tp_cdn_result_code(rescode);
2166 }
2167
2168 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2169 if (n >= 4)
2170 {
2171 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2172 LOG(4, s, t, " Error Code %d: %s\n", errcode, l2tp_error_code(errcode));
2173 }
2174 if (n > 4)
2175 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2176
2177 break;
2178 }
2179 break;
2180 case 2: // protocol version
2181 {
2182 version = ntohs(*(uint16_t *) (b));
2183 LOG(4, s, t, " Protocol version = %d\n", version);
2184 if (version && version != 0x0100)
2185 { // allow 0.0 and 1.0
2186 LOG(1, s, t, " Bad protocol version %04X\n", version);
2187 fatal = flags;
2188 result = 5; // unspported protocol version
2189 error = 0x0100; // supported version
2190 msg = 0;
2191 continue; // next
2192 }
2193 }
2194 break;
2195 case 3: // framing capabilities
2196 // LOG(4, s, t, "Framing capabilities\n");
2197 break;
2198 case 4: // bearer capabilities
2199 // LOG(4, s, t, "Bearer capabilities\n");
2200 break;
2201 case 5: // tie breaker
2202 // We never open tunnels, so we don't care about tie breakers
2203 // LOG(4, s, t, "Tie breaker\n");
2204 continue;
2205 case 6: // firmware revision
2206 // LOG(4, s, t, "Firmware revision\n");
2207 break;
2208 case 7: // host name
2209 memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
2210 memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
2211 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2212 // TBA - to send to RADIUS
2213 break;
2214 case 8: // vendor name
2215 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2216 memcpy(tunnel[t].vendor, b, (n < sizeof(tunnel[t].vendor)) ? n : sizeof(tunnel[t].vendor) - 1);
2217 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2218 break;
2219 case 9: // assigned tunnel
2220 tunnel[t].far = ntohs(*(uint16_t *) (b));
2221 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2222 break;
2223 case 10: // rx window
2224 tunnel[t].window = ntohs(*(uint16_t *) (b));
2225 if (!tunnel[t].window)
2226 tunnel[t].window = 1; // window of 0 is silly
2227 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2228 break;
2229 case 11: // Challenge
2230 {
2231 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2232 build_chap_response(b, 2, n, &chapresponse);
2233 }
2234 break;
2235 case 13: // Response
2236 // Why did they send a response? We never challenge.
2237 LOG(2, s, t, " received unexpected challenge response\n");
2238 break;
2239
2240 case 14: // assigned session
2241 asession = session[s].far = ntohs(*(uint16_t *) (b));
2242 LOG(4, s, t, " assigned session = %d\n", asession);
2243 break;
2244 case 15: // call serial number
2245 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2246 break;
2247 case 18: // bearer type
2248 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2249 // TBA - for RADIUS
2250 break;
2251 case 19: // framing type
2252 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2253 // TBA
2254 break;
2255 case 21: // called number
2256 memset(called, 0, sizeof(called));
2257 memcpy(called, b, (n < sizeof(called)) ? n : sizeof(called) - 1);
2258 LOG(4, s, t, " Called <%s>\n", called);
2259 break;
2260 case 22: // calling number
2261 memset(calling, 0, sizeof(calling));
2262 memcpy(calling, b, (n < sizeof(calling)) ? n : sizeof(calling) - 1);
2263 LOG(4, s, t, " Calling <%s>\n", calling);
2264 break;
2265 case 23: // subtype
2266 break;
2267 case 24: // tx connect speed
2268 if (n == 4)
2269 {
2270 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2271 }
2272 else
2273 {
2274 // AS5300s send connect speed as a string
2275 char tmp[30];
2276 memset(tmp, 0, sizeof(tmp));
2277 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2278 session[s].tx_connect_speed = atol(tmp);
2279 }
2280 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2281 break;
2282 case 38: // rx connect speed
2283 if (n == 4)
2284 {
2285 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2286 }
2287 else
2288 {
2289 // AS5300s send connect speed as a string
2290 char tmp[30];
2291 memset(tmp, 0, sizeof(tmp));
2292 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2293 session[s].rx_connect_speed = atol(tmp);
2294 }
2295 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2296 break;
2297 case 25: // Physical Channel ID
2298 {
2299 uint32_t tmp = ntohl(*(uint32_t *) b);
2300 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2301 break;
2302 }
2303 case 29: // Proxy Authentication Type
2304 {
2305 uint16_t atype = ntohs(*(uint16_t *)b);
2306 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, ppp_auth_type(atype));
2307 break;
2308 }
2309 case 30: // Proxy Authentication Name
2310 {
2311 char authname[64];
2312 memset(authname, 0, sizeof(authname));
2313 memcpy(authname, b, (n < sizeof(authname)) ? n : sizeof(authname) - 1);
2314 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2315 authname);
2316 break;
2317 }
2318 case 31: // Proxy Authentication Challenge
2319 {
2320 LOG(4, s, t, " Proxy Auth Challenge\n");
2321 break;
2322 }
2323 case 32: // Proxy Authentication ID
2324 {
2325 uint16_t authid = ntohs(*(uint16_t *)(b));
2326 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2327 break;
2328 }
2329 case 33: // Proxy Authentication Response
2330 LOG(4, s, t, " Proxy Auth Response\n");
2331 break;
2332 case 27: // last sent lcp
2333 { // find magic number
2334 uint8_t *p = b, *e = p + n;
2335 while (p + 1 < e && p[1] && p + p[1] <= e)
2336 {
2337 if (*p == 5 && p[1] == 6) // Magic-Number
2338 amagic = ntohl(*(uint32_t *) (p + 2));
2339 else if (*p == 7) // Protocol-Field-Compression
2340 aflags |= SESSION_PFC;
2341 else if (*p == 8) // Address-and-Control-Field-Compression
2342 aflags |= SESSION_ACFC;
2343 p += p[1];
2344 }
2345 }
2346 break;
2347 case 28: // last recv lcp confreq
2348 break;
2349 case 26: // Initial Received LCP CONFREQ
2350 break;
2351 case 39: // seq required - we control it as an LNS anyway...
2352 break;
2353 case 36: // Random Vector
2354 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2355 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2356 if (n > sizeof(session[s].random_vector))
2357 n = sizeof(session[s].random_vector);
2358 memcpy(session[s].random_vector, b, n);
2359 session[s].random_vector_length = n;
2360 break;
2361 default:
2362 {
2363 static char e[] = "unknown AVP 0xXXXX";
2364 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2365 fatal = flags;
2366 result = 2; // general error
2367 error = 8; // unknown mandatory AVP
2368 sprintf((msg = e) + 14, "%04x", mtype);
2369 continue; // next
2370 }
2371 }
2372 }
2373 // process message
2374 if (fatal & 0x80)
2375 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2376 else
2377 switch (message)
2378 {
2379 case 1: // SCCRQ - Start Control Connection Request
2380 tunnel[t].state = TUNNELOPENING;
2381 if (main_quit != QUIT_SHUTDOWN)
2382 {
2383 controlt *c = controlnew(2); // sending SCCRP
2384 control16(c, 2, version, 1); // protocol version
2385 control32(c, 3, 3, 1); // framing
2386 controls(c, 7, hostname, 1); // host name
2387 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2388 control16(c, 9, t, 1); // assigned tunnel
2389 controladd(c, 0, t); // send the resply
2390 }
2391 else
2392 {
2393 tunnelshutdown(t, "Shutting down", 6, 0, 0);
2394 }
2395 break;
2396 case 2: // SCCRP
2397 tunnel[t].state = TUNNELOPEN;
2398 break;
2399 case 3: // SCCN
2400 tunnel[t].state = TUNNELOPEN;
2401 controlnull(t); // ack
2402 break;
2403 case 4: // StopCCN
2404 controlnull(t); // ack
2405 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2406 break;
2407 case 6: // HELLO
2408 controlnull(t); // simply ACK
2409 break;
2410 case 7: // OCRQ
2411 // TBA
2412 break;
2413 case 8: // OCRO
2414 // TBA
2415 break;
2416 case 9: // OCCN
2417 // TBA
2418 break;
2419 case 10: // ICRQ
2420 if (sessionfree && main_quit != QUIT_SHUTDOWN)
2421 {
2422 controlt *c = controlnew(11); // ICRP
2423
2424 s = sessionfree;
2425 sessionfree = session[s].next;
2426 memset(&session[s], 0, sizeof(session[s]));
2427
2428 if (s > config->cluster_highest_sessionid)
2429 config->cluster_highest_sessionid = s;
2430
2431 session[s].opened = time_now;
2432 session[s].tunnel = t;
2433 session[s].far = asession;
2434 session[s].last_packet = time_now;
2435 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2436 control16(c, 14, s, 1); // assigned session
2437 controladd(c, asession, t); // send the reply
2438
2439 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2440 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2441
2442 session[s].ppp.phase = Establish;
2443 session[s].ppp.lcp = Starting;
2444
2445 STAT(session_created);
2446 break;
2447 }
2448
2449 {
2450 controlt *c = controlnew(14); // CDN
2451 if (!sessionfree)
2452 {
2453 STAT(session_overflow);
2454 LOG(1, 0, t, "No free sessions\n");
2455 control16(c, 1, 4, 0); // temporary lack of resources
2456 }
2457 else
2458 control16(c, 1, 2, 7); // shutting down, try another
2459
2460 controladd(c, asession, t); // send the message
2461 }
2462 return;
2463 case 11: // ICRP
2464 // TBA
2465 break;
2466 case 12: // ICCN
2467 if (amagic == 0) amagic = time_now;
2468 session[s].magic = amagic; // set magic number
2469 session[s].flags = aflags; // set flags received
2470 session[s].mru = PPPMTU; // default
2471 controlnull(t); // ack
2472
2473 // start LCP
2474 sess_local[s].lcp_authtype = config->radius_authprefer;
2475 sess_local[s].ppp_mru = MRU;
2476 sendlcp(s, t);
2477 change_state(s, lcp, RequestSent);
2478 break;
2479
2480 case 14: // CDN
2481 controlnull(t); // ack
2482 sessionshutdown(s, "Closed (Received CDN).", 0, 0);
2483 break;
2484 case 0xFFFF:
2485 LOG(1, s, t, "Missing message type\n");
2486 break;
2487 default:
2488 STAT(tunnel_rx_errors);
2489 if (mandatory)
2490 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2491 else
2492 LOG(1, s, t, "Unknown message type %d\n", message);
2493 break;
2494 }
2495 if (chapresponse) free(chapresponse);
2496 cluster_send_tunnel(t);
2497 }
2498 else
2499 {
2500 LOG(4, s, t, " Got a ZLB ack\n");
2501 }
2502 }
2503 else
2504 { // data
2505 uint16_t proto;
2506
2507 LOG_HEX(5, "Receive Tunnel Data", p, l);
2508 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2509 { // HDLC address header, discard
2510 p += 2;
2511 l -= 2;
2512 }
2513 if (l < 2)
2514 {
2515 LOG(1, s, t, "Short ppp length %d\n", l);
2516 STAT(tunnel_rx_errors);
2517 return;
2518 }
2519 if (*p & 1)
2520 {
2521 proto = *p++;
2522 l--;
2523 }
2524 else
2525 {
2526 proto = ntohs(*(uint16_t *) p);
2527 p += 2;
2528 l -= 2;
2529 }
2530
2531 if (s && !session[s].opened) // Is something wrong??
2532 {
2533 if (!config->cluster_iam_master)
2534 {
2535 // Pass it off to the master to deal with..
2536 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2537 return;
2538 }
2539
2540
2541 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2542 STAT(tunnel_rx_errors);
2543 return;
2544 }
2545
2546 if (proto == PPPPAP)
2547 {
2548 session[s].last_packet = time_now;
2549 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2550 processpap(s, t, p, l);
2551 }
2552 else if (proto == PPPCHAP)
2553 {
2554 session[s].last_packet = time_now;
2555 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2556 processchap(s, t, p, l);
2557 }
2558 else if (proto == PPPLCP)
2559 {
2560 session[s].last_packet = time_now;
2561 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2562 processlcp(s, t, p, l);
2563 }
2564 else if (proto == PPPIPCP)
2565 {
2566 session[s].last_packet = time_now;
2567 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2568 processipcp(s, t, p, l);
2569 }
2570 else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[0])
2571 {
2572 session[s].last_packet = time_now;
2573 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2574 processipv6cp(s, t, p, l);
2575 }
2576 else if (proto == PPPCCP)
2577 {
2578 session[s].last_packet = time_now;
2579 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2580 processccp(s, t, p, l);
2581 }
2582 else if (proto == PPPIP)
2583 {
2584 if (session[s].die)
2585 {
2586 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2587 return; // closing session, PPP not processed
2588 }
2589
2590 session[s].last_packet = time_now;
2591 if (session[s].walled_garden && !config->cluster_iam_master)
2592 {
2593 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2594 return;
2595 }
2596
2597 processipin(s, t, p, l);
2598 }
2599 else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
2600 {
2601 if (session[s].die)
2602 {
2603 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2604 return; // closing session, PPP not processed
2605 }
2606
2607 session[s].last_packet = time_now;
2608 if (session[s].walled_garden && !config->cluster_iam_master)
2609 {
2610 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2611 return;
2612 }
2613
2614 processipv6in(s, t, p, l);
2615 }
2616 else if (session[s].ppp.lcp == Opened)
2617 {
2618 session[s].last_packet = time_now;
2619 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2620 protoreject(s, t, p, l, proto);
2621 }
2622 else
2623 {
2624 LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
2625 proto, ppp_state(session[s].ppp.lcp));
2626 }
2627 }
2628 }
2629
2630 // read and process packet on tun
2631 static void processtun(uint8_t * buf, int len)
2632 {
2633 LOG_HEX(5, "Receive TUN Data", buf, len);
2634 STAT(tun_rx_packets);
2635 INC_STAT(tun_rx_bytes, len);
2636
2637 CSTAT(processtun);
2638
2639 eth_rx_pkt++;
2640 eth_rx += len;
2641 if (len < 22)
2642 {
2643 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2644 STAT(tun_rx_errors);
2645 return;
2646 }
2647
2648 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2649 processipout(buf, len);
2650 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2651 && config->ipv6_prefix.s6_addr[0])
2652 processipv6out(buf, len);
2653
2654 // Else discard.
2655 }
2656
2657 // Handle retries, timeouts. Runs every 1/10th sec, want to ensure
2658 // that we look at the whole of the tunnel, radius and session tables
2659 // every second
2660 static void regular_cleanups(double period)
2661 {
2662 // Next tunnel, radius and session to check for actions on.
2663 static tunnelidt t = 0;
2664 static int r = 0;
2665 static sessionidt s = 0;
2666
2667 int t_actions = 0;
2668 int r_actions = 0;
2669 int s_actions = 0;
2670
2671 int t_slice;
2672 int r_slice;
2673 int s_slice;
2674
2675 int i;
2676 int a;
2677
2678 // divide up tables into slices based on the last run
2679 t_slice = config->cluster_highest_tunnelid * period;
2680 r_slice = (MAXRADIUS - 1) * period;
2681 s_slice = config->cluster_highest_sessionid * period;
2682
2683 if (t_slice < 1)
2684 t_slice = 1;
2685 else if (t_slice > config->cluster_highest_tunnelid)
2686 t_slice = config->cluster_highest_tunnelid;
2687
2688 if (r_slice < 1)
2689 r_slice = 1;
2690 else if (r_slice > (MAXRADIUS - 1))
2691 r_slice = MAXRADIUS - 1;
2692
2693 if (s_slice < 1)
2694 s_slice = 1;
2695 else if (s_slice > config->cluster_highest_sessionid)
2696 s_slice = config->cluster_highest_sessionid;
2697
2698 LOG(4, 0, 0, "Begin regular cleanup (last %f seconds ago)\n", period);
2699
2700 for (i = 0; i < t_slice; i++)
2701 {
2702 t++;
2703 if (t > config->cluster_highest_tunnelid)
2704 t = 1;
2705
2706 // check for expired tunnels
2707 if (tunnel[t].die && tunnel[t].die <= TIME)
2708 {
2709 STAT(tunnel_timeout);
2710 tunnelkill(t, "Expired");
2711 t_actions++;
2712 continue;
2713 }
2714 // check for message resend
2715 if (tunnel[t].retry && tunnel[t].controlc)
2716 {
2717 // resend pending messages as timeout on reply
2718 if (tunnel[t].retry <= TIME)
2719 {
2720 controlt *c = tunnel[t].controls;
2721 uint8_t w = tunnel[t].window;
2722 tunnel[t].try++; // another try
2723 if (tunnel[t].try > 5)
2724 tunnelkill(t, "Timeout on control message"); // game over
2725 else
2726 while (c && w--)
2727 {
2728 tunnelsend(c->buf, c->length, t);
2729 c = c->next;
2730 }
2731
2732 t_actions++;
2733 }
2734 }
2735 // Send hello
2736 if (tunnel[t].state == TUNNELOPEN && !tunnel[t].controlc && (time_now - tunnel[t].lastrec) > 60)
2737 {
2738 controlt *c = controlnew(6); // sending HELLO
2739 controladd(c, 0, t); // send the message
2740 LOG(3, 0, t, "Sending HELLO message\n");
2741 t_actions++;
2742 }
2743
2744 // Check for tunnel changes requested from the CLI
2745 if ((a = cli_tunnel_actions[t].action))
2746 {
2747 cli_tunnel_actions[t].action = 0;
2748 if (a & CLI_TUN_KILL)
2749 {
2750 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2751 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2752 t_actions++;
2753 }
2754 }
2755 }
2756
2757 for (i = 0; i < r_slice; i++)
2758 {
2759 r++;
2760 if (r >= MAXRADIUS)
2761 r = 1;
2762
2763 if (!radius[r].state)
2764 continue;
2765
2766 if (radius[r].retry <= TIME)
2767 {
2768 radiusretry(r);
2769 r_actions++;
2770 }
2771 }
2772
2773 for (i = 0; i < s_slice; i++)
2774 {
2775 s++;
2776 if (s > config->cluster_highest_sessionid)
2777 s = 1;
2778
2779 if (!session[s].opened) // Session isn't in use
2780 continue;
2781
2782 // check for expired sessions
2783 if (session[s].die)
2784 {
2785 if (session[s].die <= TIME)
2786 {
2787 sessionkill(s, "Expired");
2788 s_actions++;
2789 }
2790 continue;
2791 }
2792
2793 // PPP timeouts
2794 if (sess_local[s].lcp.restart <= time_now)
2795 {
2796 int next_state = session[s].ppp.lcp;
2797 switch (session[s].ppp.lcp)
2798 {
2799 case RequestSent:
2800 case AckReceived:
2801 next_state = RequestSent;
2802
2803 case AckSent:
2804 if (sess_local[s].lcp.conf_sent < config->ppp_max_configure)
2805 {
2806 LOG(3, s, session[s].tunnel, "No ACK for LCP ConfigReq... resending\n");
2807 sendlcp(s, session[s].tunnel);
2808 change_state(s, lcp, next_state);
2809 }
2810 else
2811 {
2812 sessionshutdown(s, "No response to LCP ConfigReq.", 3, 0);
2813 STAT(session_timeout);
2814 }
2815
2816 s_actions++;
2817 }
2818
2819 if (session[s].die)
2820 continue;
2821 }
2822
2823 if (sess_local[s].ipcp.restart <= time_now)
2824 {
2825 int next_state = session[s].ppp.ipcp;
2826 switch (session[s].ppp.ipcp)
2827 {
2828 case RequestSent:
2829 case AckReceived:
2830 next_state = RequestSent;
2831
2832 case AckSent:
2833 if (sess_local[s].ipcp.conf_sent < config->ppp_max_configure)
2834 {
2835 LOG(3, s, session[s].tunnel, "No ACK for IPCP ConfigReq... resending\n");
2836 sendipcp(s, session[s].tunnel);
2837 change_state(s, ipcp, next_state);
2838 }
2839 else
2840 {
2841 sessionshutdown(s, "No response to IPCP ConfigReq.", 3, 0);
2842 STAT(session_timeout);
2843 }
2844
2845 s_actions++;
2846 }
2847
2848 if (session[s].die)
2849 continue;
2850 }
2851
2852 if (sess_local[s].ipv6cp.restart <= time_now)
2853 {
2854 int next_state = session[s].ppp.ipv6cp;
2855 switch (session[s].ppp.ipv6cp)
2856 {
2857 case RequestSent:
2858 case AckReceived:
2859 next_state = RequestSent;
2860
2861 case AckSent:
2862 if (sess_local[s].ipv6cp.conf_sent < config->ppp_max_configure)
2863 {
2864 LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq... resending\n");
2865 sendipv6cp(s, session[s].tunnel);
2866 change_state(s, ipv6cp, next_state);
2867 }
2868 else
2869 {
2870 LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq\n");
2871 change_state(s, ipv6cp, Stopped);
2872 }
2873
2874 s_actions++;
2875 }
2876 }
2877
2878 if (sess_local[s].ccp.restart <= time_now)
2879 {
2880 int next_state = session[s].ppp.ccp;
2881 switch (session[s].ppp.ccp)
2882 {
2883 case RequestSent:
2884 case AckReceived:
2885 next_state = RequestSent;
2886
2887 case AckSent:
2888 if (sess_local[s].ccp.conf_sent < config->ppp_max_configure)
2889 {
2890 LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq... resending\n");
2891 sendccp(s, session[s].tunnel);
2892 change_state(s, ccp, next_state);
2893 }
2894 else
2895 {
2896 LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq\n");
2897 change_state(s, ccp, Stopped);
2898 }
2899
2900 s_actions++;
2901 }
2902 }
2903
2904 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2905 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2906 {
2907 sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
2908 STAT(session_timeout);
2909 s_actions++;
2910 continue;
2911 }
2912
2913 // No data in ECHO_TIMEOUT seconds, send LCP ECHO
2914 if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT) &&
2915 (time_now - sess_local[s].last_echo >= ECHO_TIMEOUT))
2916 {
2917 uint8_t b[MAXETHER];
2918
2919 uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP);
2920 if (!q) continue;
2921
2922 *q = EchoReq;
2923 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2924 *(uint16_t *)(q + 2) = htons(8); // Length
2925 *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
2926
2927 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2928 (int)(time_now - session[s].last_packet));
2929 tunnelsend(b, 24, session[s].tunnel); // send it
2930 sess_local[s].last_echo = time_now;
2931 s_actions++;
2932 }
2933
2934 // Check for actions requested from the CLI
2935 if ((a = cli_session_actions[s].action))
2936 {
2937 int send = 0;
2938
2939 cli_session_actions[s].action = 0;
2940 if (a & CLI_SESS_KILL)
2941 {
2942 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2943 sessionshutdown(s, "Requested by administrator.", 3, 0);
2944 a = 0; // dead, no need to check for other actions
2945 s_actions++;
2946 }
2947
2948 if (a & CLI_SESS_NOSNOOP)
2949 {
2950 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2951 session[s].snoop_ip = 0;
2952 session[s].snoop_port = 0;
2953 s_actions++;
2954 send++;
2955 }
2956 else if (a & CLI_SESS_SNOOP)
2957 {
2958 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2959 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2960 cli_session_actions[s].snoop_port);
2961
2962 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2963 session[s].snoop_port = cli_session_actions[s].snoop_port;
2964 s_actions++;
2965 send++;
2966 }
2967
2968 if (a & CLI_SESS_NOTHROTTLE)
2969 {
2970 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2971 throttle_session(s, 0, 0);
2972 s_actions++;
2973 send++;
2974 }
2975 else if (a & CLI_SESS_THROTTLE)
2976 {
2977 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2978 cli_session_actions[s].throttle_in,
2979 cli_session_actions[s].throttle_out);
2980
2981 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
2982 s_actions++;
2983 send++;
2984 }
2985
2986 if (a & CLI_SESS_NOFILTER)
2987 {
2988 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
2989 filter_session(s, 0, 0);
2990 s_actions++;
2991 send++;
2992 }
2993 else if (a & CLI_SESS_FILTER)
2994 {
2995 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
2996 cli_session_actions[s].filter_in,
2997 cli_session_actions[s].filter_out);
2998
2999 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
3000 s_actions++;
3001 send++;
3002 }
3003
3004 if (send)
3005 cluster_send_session(s);
3006 }
3007
3008 // RADIUS interim accounting
3009 if (config->radius_accounting && config->radius_interim > 0
3010 && session[s].ip && !session[s].walled_garden
3011 && !sess_local[s].radius // RADIUS already in progress
3012 && time_now - sess_local[s].last_interim >= config->radius_interim)
3013 {
3014 int rad = radiusnew(s);
3015 if (!rad)
3016 {
3017 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
3018 STAT(radius_overflow);
3019 continue;
3020 }
3021
3022 LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
3023 session[s].user, session[s].unique_id);
3024
3025 radiussend(rad, RADIUSINTERIM);
3026 sess_local[s].last_interim = time_now;
3027 s_actions++;
3028 }
3029 }
3030
3031 LOG(4, 0, 0, "End regular cleanup: checked %d/%d/%d tunnels/radius/sessions; %d/%d/%d actions\n",
3032 t_slice, r_slice, s_slice, t_actions, r_actions, s_actions);
3033 }
3034
3035 //
3036 // Are we in the middle of a tunnel update, or radius
3037 // requests??
3038 //
3039 static int still_busy(void)
3040 {
3041 int i;
3042 static clockt last_talked = 0;
3043 static clockt start_busy_wait = 0;
3044
3045 if (!config->cluster_iam_master)
3046 {
3047 #ifdef BGP
3048 static time_t stopped_bgp = 0;
3049 if (bgp_configured)
3050 {
3051 if (!stopped_bgp)
3052 {
3053 LOG(1, 0, 0, "Shutting down in %d seconds, stopping BGP...\n", QUIT_DELAY);
3054
3055 for (i = 0; i < BGP_NUM_PEERS; i++)
3056 if (bgp_peers[i].state == Established)
3057 bgp_stop(&bgp_peers[i]);
3058
3059 stopped_bgp = time_now;
3060
3061 // we don't want to become master
3062 cluster_send_ping(0);
3063
3064 return 1;
3065 }
3066
3067 if (time_now < (stopped_bgp + QUIT_DELAY))
3068 return 1;
3069 }
3070 #endif /* BGP */
3071
3072 return 0;
3073 }
3074
3075 if (main_quit == QUIT_SHUTDOWN)
3076 {
3077 static int dropped = 0;
3078 if (!dropped)
3079 {
3080 int i;
3081
3082 LOG(1, 0, 0, "Dropping sessions and tunnels\n");
3083 for (i = 1; i < MAXTUNNEL; i++)
3084 if (tunnel[i].ip || tunnel[i].state)
3085 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3086
3087 dropped = 1;
3088 }
3089 }
3090
3091 if (start_busy_wait == 0)
3092 start_busy_wait = TIME;
3093
3094 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
3095 {
3096 if (!tunnel[i].controlc)
3097 continue;
3098
3099 if (last_talked != TIME)
3100 {
3101 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
3102 last_talked = TIME;
3103 }
3104 return 1;
3105 }
3106
3107 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
3108 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
3109 {
3110 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
3111 return 0;
3112 }
3113
3114 for (i = 1; i < MAXRADIUS; i++)
3115 {
3116 if (radius[i].state == RADIUSNULL)
3117 continue;
3118 if (radius[i].state == RADIUSWAIT)
3119 continue;
3120
3121 if (last_talked != TIME)
3122 {
3123 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
3124 last_talked = TIME;
3125 }
3126 return 1;
3127 }
3128
3129 return 0;
3130 }
3131
3132 #ifdef HAVE_EPOLL
3133 # include <sys/epoll.h>
3134 #else
3135 # define FAKE_EPOLL_IMPLEMENTATION /* include the functions */
3136 # include "fake_epoll.h"
3137 #endif
3138
3139 // the base set of fds polled: cli, cluster, tun, udp, control, dae
3140 #define BASE_FDS 6
3141
3142 // additional polled fds
3143 #ifdef BGP
3144 # define EXTRA_FDS BGP_NUM_PEERS
3145 #else
3146 # define EXTRA_FDS 0
3147 #endif
3148
3149 // main loop - gets packets on tun or udp and processes them
3150 static void mainloop(void)
3151 {
3152 int i;
3153 uint8_t buf[65536];
3154 clockt next_cluster_ping = 0; // send initial ping immediately
3155 struct epoll_event events[BASE_FDS + RADIUS_FDS + EXTRA_FDS];
3156 int maxevent = sizeof(events)/sizeof(*events);
3157
3158 if ((epollfd = epoll_create(maxevent)) < 0)
3159 {
3160 LOG(0, 0, 0, "epoll_create failed: %s\n", strerror(errno));
3161 exit(1);
3162 }
3163
3164 LOG(4, 0, 0, "Beginning of main loop. clifd=%d, cluster_sockfd=%d, tunfd=%d, udpfd=%d, controlfd=%d, daefd=%d\n",
3165 clifd, cluster_sockfd, tunfd, udpfd, controlfd, daefd);
3166
3167 /* setup our fds to poll for input */
3168 {
3169 static struct event_data d[BASE_FDS];
3170 struct epoll_event e;
3171
3172 e.events = EPOLLIN;
3173 i = 0;
3174
3175 d[i].type = FD_TYPE_CLI;
3176 e.data.ptr = &d[i++];
3177 epoll_ctl(epollfd, EPOLL_CTL_ADD, clifd, &e);
3178
3179 d[i].type = FD_TYPE_CLUSTER;
3180 e.data.ptr = &d[i++];
3181 epoll_ctl(epollfd, EPOLL_CTL_ADD, cluster_sockfd, &e);
3182
3183 d[i].type = FD_TYPE_TUN;
3184 e.data.ptr = &d[i++];
3185 epoll_ctl(epollfd, EPOLL_CTL_ADD, tunfd, &e);
3186
3187 d[i].type = FD_TYPE_UDP;
3188 e.data.ptr = &d[i++];
3189 epoll_ctl(epollfd, EPOLL_CTL_ADD, udpfd, &e);
3190
3191 d[i].type = FD_TYPE_CONTROL;
3192 e.data.ptr = &d[i++];
3193 epoll_ctl(epollfd, EPOLL_CTL_ADD, controlfd, &e);
3194
3195 d[i].type = FD_TYPE_DAE;
3196 e.data.ptr = &d[i++];
3197 epoll_ctl(epollfd, EPOLL_CTL_ADD, daefd, &e);
3198 }
3199
3200 #ifdef BGP
3201 signal(SIGPIPE, SIG_IGN);
3202 bgp_setup(config->as_number);
3203 if (config->bind_address)
3204 bgp_add_route(config->bind_address, 0xffffffff);
3205
3206 for (i = 0; i < BGP_NUM_PEERS; i++)
3207 {
3208 if (config->neighbour[i].name[0])
3209 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3210 config->neighbour[i].as, config->neighbour[i].keepalive,
3211 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3212 }
3213 #endif /* BGP */
3214
3215 while (!main_quit || still_busy())
3216 {
3217 int more = 0;
3218 int n;
3219
3220
3221 if (main_reload)
3222 {
3223 main_reload = 0;
3224 read_config_file();
3225 config->reload_config++;
3226 }
3227
3228 if (config->reload_config)
3229 {
3230 config->reload_config = 0;
3231 update_config();
3232 }
3233
3234 #ifdef BGP
3235 bgp_set_poll();
3236 #endif /* BGP */
3237
3238 n = epoll_wait(epollfd, events, maxevent, 100); // timeout 100ms (1/10th sec)
3239 STAT(select_called);
3240
3241 TIME = now(NULL);
3242 if (n < 0)
3243 {
3244 if (errno == EINTR ||
3245 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
3246 continue;
3247
3248 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
3249 break; // exit
3250 }
3251
3252 if (n)
3253 {
3254 struct sockaddr_in addr;
3255 socklen_t alen;
3256 int c, s;
3257 int udp_ready = 0;
3258 int tun_ready = 0;
3259 int cluster_ready = 0;
3260 int udp_pkts = 0;
3261 int tun_pkts = 0;
3262 int cluster_pkts = 0;
3263 #ifdef BGP
3264 uint32_t bgp_events[BGP_NUM_PEERS];
3265 memset(bgp_events, 0, sizeof(bgp_events));
3266 #endif /* BGP */
3267
3268 for (c = n, i = 0; i < c; i++)
3269 {
3270 struct event_data *d = events[i].data.ptr;
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 processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
3298 n--;
3299 break;
3300
3301 case FD_TYPE_DAE: // DAE requests
3302 alen = sizeof(addr);
3303 processdae(buf, recvfrom(daefd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
3304 n--;
3305 break;
3306
3307 case FD_TYPE_RADIUS: // RADIUS response
3308 s = recv(radfds[d->index], buf, sizeof(buf), 0);
3309 if (s >= 0 && config->cluster_iam_master)
3310 processrad(buf, s, d->index);
3311
3312 n--;
3313 break;
3314
3315 #ifdef BGP
3316 case FD_TYPE_BGP:
3317 bgp_events[d->index] = events[i].events;
3318 n--;
3319 break;
3320 #endif /* BGP */
3321
3322 default:
3323 LOG(0, 0, 0, "Unexpected fd type returned from epoll_wait: %d\n", d->type);
3324 }
3325 }
3326
3327 #ifdef BGP
3328 bgp_process(bgp_events);
3329 #endif /* BGP */
3330
3331 for (c = 0; n && c < config->multi_read_count; c++)
3332 {
3333 // L2TP
3334 if (udp_ready)
3335 {
3336 alen = sizeof(addr);
3337 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
3338 {
3339 processudp(buf, s, &addr);
3340 udp_pkts++;
3341 }
3342 else
3343 {
3344 udp_ready = 0;
3345 n--;
3346 }
3347 }
3348
3349 // incoming IP
3350 if (tun_ready)
3351 {
3352 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
3353 {
3354 processtun(buf, s);
3355 tun_pkts++;
3356 }
3357 else
3358 {
3359 tun_ready = 0;
3360 n--;
3361 }
3362 }
3363
3364 // cluster
3365 if (cluster_ready)
3366 {
3367 alen = sizeof(addr);
3368 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
3369 {
3370 processcluster(buf, s, addr.sin_addr.s_addr);
3371 cluster_pkts++;
3372 }
3373 else
3374 {
3375 cluster_ready = 0;
3376 n--;
3377 }
3378 }
3379 }
3380
3381 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
3382 STAT(multi_read_used);
3383
3384 if (c >= config->multi_read_count)
3385 {
3386 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
3387 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3388
3389 STAT(multi_read_exceeded);
3390 more++;
3391 }
3392 }
3393
3394 if (time_changed)
3395 {
3396 double Mbps = 1024.0 * 1024.0 / 8 * time_changed;
3397
3398 // Log current traffic stats
3399 snprintf(config->bandwidth, sizeof(config->bandwidth),
3400 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3401 (udp_rx / Mbps), (eth_tx / Mbps), (eth_rx / Mbps), (udp_tx / Mbps),
3402 ((udp_tx + udp_rx + eth_tx + eth_rx) / Mbps),
3403 udp_rx_pkt / time_changed, eth_rx_pkt / time_changed);
3404
3405 udp_tx = udp_rx = 0;
3406 udp_rx_pkt = eth_rx_pkt = 0;
3407 eth_tx = eth_rx = 0;
3408 time_changed = 0;
3409
3410 if (config->dump_speed)
3411 printf("%s\n", config->bandwidth);
3412
3413 // Update the internal time counter
3414 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3415
3416 {
3417 // Run timer hooks
3418 struct param_timer p = { time_now };
3419 run_plugins(PLUGIN_TIMER, &p);
3420 }
3421 }
3422
3423 // Runs on every machine (master and slaves).
3424 if (next_cluster_ping <= TIME)
3425 {
3426 // Check to see which of the cluster is still alive..
3427
3428 cluster_send_ping(basetime); // Only does anything if we're a slave
3429 cluster_check_master(); // ditto.
3430
3431 cluster_heartbeat(); // Only does anything if we're a master.
3432 cluster_check_slaves(); // ditto.
3433
3434 master_update_counts(); // If we're a slave, send our byte counters to our master.
3435
3436 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3437 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3438 else
3439 next_cluster_ping = TIME + config->cluster_hb_interval;
3440 }
3441
3442 if (!config->cluster_iam_master)
3443 continue;
3444
3445 // Run token bucket filtering queue..
3446 // Only run it every 1/10th of a second.
3447 {
3448 static clockt last_run = 0;
3449 if (last_run != TIME)
3450 {
3451 last_run = TIME;
3452 tbf_run_timer();
3453 }
3454 }
3455
3456 // Handle timeouts, retries etc.
3457 {
3458 static double last_clean = 0;
3459 double this_clean;
3460 double diff;
3461
3462 TIME = now(&this_clean);
3463 diff = this_clean - last_clean;
3464
3465 // Run during idle time (after we've handled
3466 // all incoming packets) or every 1/10th sec
3467 if (!more || diff > 0.1)
3468 {
3469 regular_cleanups(diff);
3470 last_clean = this_clean;
3471 }
3472 }
3473
3474 if (*config->accounting_dir)
3475 {
3476 static clockt next_acct = 0;
3477 static clockt next_shut_acct = 0;
3478
3479 if (next_acct <= TIME)
3480 {
3481 // Dump accounting data
3482 next_acct = TIME + ACCT_TIME;
3483 next_shut_acct = TIME + ACCT_SHUT_TIME;
3484 dump_acct_info(1);
3485 }
3486 else if (next_shut_acct <= TIME)
3487 {
3488 // Dump accounting data for shutdown sessions
3489 next_shut_acct = TIME + ACCT_SHUT_TIME;
3490 if (shut_acct_n)
3491 dump_acct_info(0);
3492 }
3493 }
3494 }
3495
3496 // Are we the master and shutting down??
3497 if (config->cluster_iam_master)
3498 cluster_heartbeat(); // Flush any queued changes..
3499
3500 // Ok. Notify everyone we're shutting down. If we're
3501 // the master, this will force an election.
3502 cluster_send_ping(0);
3503
3504 //
3505 // Important!!! We MUST not process any packets past this point!
3506 LOG(1, 0, 0, "Shutdown complete\n");
3507 }
3508
3509 static void stripdomain(char *host)
3510 {
3511 char *p;
3512
3513 if ((p = strchr(host, '.')))
3514 {
3515 char *domain = 0;
3516 char _domain[1024];
3517
3518 // strip off domain
3519 FILE *resolv = fopen("/etc/resolv.conf", "r");
3520 if (resolv)
3521 {
3522 char buf[1024];
3523 char *b;
3524
3525 while (fgets(buf, sizeof(buf), resolv))
3526 {
3527 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3528 continue;
3529
3530 if (!isspace(buf[6]))
3531 continue;
3532
3533 b = buf + 7;
3534 while (isspace(*b)) b++;
3535
3536 if (*b)
3537 {
3538 char *d = b;
3539 while (*b && !isspace(*b)) b++;
3540 *b = 0;
3541 if (buf[0] == 'd') // domain is canonical
3542 {
3543 domain = d;
3544 break;
3545 }
3546
3547 // first search line
3548 if (!domain)
3549 {
3550 // hold, may be subsequent domain line
3551 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3552 domain = _domain;
3553 }
3554 }
3555 }
3556
3557 fclose(resolv);
3558 }
3559
3560 if (domain)
3561 {
3562 int hl = strlen(host);
3563 int dl = strlen(domain);
3564 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3565 host[hl -dl - 1] = 0;
3566 }
3567 else
3568 {
3569 *p = 0; // everything after first dot
3570 }
3571 }
3572 }
3573
3574 // Init data structures
3575 static void initdata(int optdebug, char *optconfig)
3576 {
3577 int i;
3578
3579 if (!(config = shared_malloc(sizeof(configt))))
3580 {
3581 fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
3582 exit(1);
3583 }
3584
3585 memset(config, 0, sizeof(configt));
3586 time(&config->start_time);
3587 strncpy(config->config_file, optconfig, strlen(optconfig));
3588 config->debug = optdebug;
3589 config->num_tbfs = MAXTBFS;
3590 config->rl_rate = 28; // 28kbps
3591 config->cluster_mcast_ttl = 1;
3592 config->cluster_master_min_adv = 1;
3593 config->ppp_restart_time = 3;
3594 config->ppp_max_configure = 10;
3595 config->ppp_max_failure = 5;
3596 strcpy(config->random_device, RANDOMDEVICE);
3597
3598 log_stream = stderr;
3599
3600 #ifdef RINGBUFFER
3601 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3602 {
3603 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3604 exit(1);
3605 }
3606 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3607 #endif
3608
3609 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3610 {
3611 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3612 exit(1);
3613 }
3614 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3615 {
3616 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3617 exit(1);
3618 }
3619 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3620 {
3621 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3622 exit(1);
3623 }
3624
3625 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3626 {
3627 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3628 exit(1);
3629 }
3630
3631 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3632 {
3633 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3634 exit(1);
3635 }
3636
3637 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3638 {
3639 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3640 exit(1);
3641 }
3642
3643 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3644 {
3645 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3646 exit(1);
3647 }
3648 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3649
3650 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3651 {
3652 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3653 exit(1);
3654 }
3655 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3656
3657 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3658 {
3659 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3660 exit(1);
3661 }
3662 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3663
3664 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3665 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3666 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3667 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3668
3669 // Put all the sessions on the free list marked as undefined.
3670 for (i = 1; i < MAXSESSION; i++)
3671 {
3672 session[i].next = i + 1;
3673 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3674 }
3675 session[MAXSESSION - 1].next = 0;
3676 sessionfree = 1;
3677
3678 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3679 for (i = 1; i < MAXTUNNEL; i++)
3680 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3681
3682 if (!*hostname)
3683 {
3684 // Grab my hostname unless it's been specified
3685 gethostname(hostname, sizeof(hostname));
3686 stripdomain(hostname);
3687 }
3688
3689 _statistics->start_time = _statistics->last_reset = time(NULL);
3690
3691 #ifdef BGP
3692 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3693 {
3694 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3695 exit(1);
3696 }
3697 #endif /* BGP */
3698 }
3699
3700 static int assign_ip_address(sessionidt s)
3701 {
3702 uint32_t i;
3703 int best = -1;
3704 time_t best_time = time_now;
3705 char *u = session[s].user;
3706 char reuse = 0;
3707
3708
3709 CSTAT(assign_ip_address);
3710
3711 for (i = 1; i < ip_pool_size; i++)
3712 {
3713 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3714 continue;
3715
3716 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3717 {
3718 best = i;
3719 reuse = 1;
3720 break;
3721 }
3722
3723 if (ip_address_pool[i].last < best_time)
3724 {
3725 best = i;
3726 if (!(best_time = ip_address_pool[i].last))
3727 break; // never used, grab this one
3728 }
3729 }
3730
3731 if (best < 0)
3732 {
3733 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3734 return 0;
3735 }
3736
3737 session[s].ip = ip_address_pool[best].address;
3738 session[s].ip_pool_index = best;
3739 ip_address_pool[best].assigned = 1;
3740 ip_address_pool[best].last = time_now;
3741 ip_address_pool[best].session = s;
3742 if (session[s].walled_garden)
3743 /* Don't track addresses of users in walled garden (note: this
3744 means that their address isn't "sticky" even if they get
3745 un-gardened). */
3746 ip_address_pool[best].user[0] = 0;
3747 else
3748 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3749
3750 STAT(ip_allocated);
3751 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3752 reuse ? "Reusing" : "Allocating", best);
3753
3754 return 1;
3755 }
3756
3757 static void free_ip_address(sessionidt s)
3758 {
3759 int i = session[s].ip_pool_index;
3760
3761
3762 CSTAT(free_ip_address);
3763
3764 if (!session[s].ip)
3765 return; // what the?
3766
3767 if (i < 0) // Is this actually part of the ip pool?
3768 i = 0;
3769
3770 STAT(ip_freed);
3771 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3772 session[s].ip = 0;
3773 ip_address_pool[i].assigned = 0;
3774 ip_address_pool[i].session = 0;
3775 ip_address_pool[i].last = time_now;
3776 }
3777
3778 //
3779 // Fsck the address pool against the session table.
3780 // Normally only called when we become a master.
3781 //
3782 // This isn't perfect: We aren't keep tracking of which
3783 // users used to have an IP address.
3784 //
3785 void rebuild_address_pool(void)
3786 {
3787 int i;
3788
3789 //
3790 // Zero the IP pool allocation, and build
3791 // a map from IP address to pool index.
3792 for (i = 1; i < MAXIPPOOL; ++i)
3793 {
3794 ip_address_pool[i].assigned = 0;
3795 ip_address_pool[i].session = 0;
3796 if (!ip_address_pool[i].address)
3797 continue;
3798
3799 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3800 }
3801
3802 for (i = 0; i < MAXSESSION; ++i)
3803 {
3804 int ipid;
3805 if (!(session[i].opened && session[i].ip))
3806 continue;
3807
3808 ipid = - lookup_ipmap(htonl(session[i].ip));
3809
3810 if (session[i].ip_pool_index < 0)
3811 {
3812 // Not allocated out of the pool.
3813 if (ipid < 1) // Not found in the pool either? good.
3814 continue;
3815
3816 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3817 i, fmtaddr(session[i].ip, 0), ipid);
3818
3819 // Fall through and process it as part of the pool.
3820 }
3821
3822
3823 if (ipid > MAXIPPOOL || ipid < 0)
3824 {
3825 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3826 ipid = -1;
3827 session[i].ip_pool_index = ipid;
3828 continue;
3829 }
3830
3831 ip_address_pool[ipid].assigned = 1;
3832 ip_address_pool[ipid].session = i;
3833 ip_address_pool[ipid].last = time_now;
3834 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3835 session[i].ip_pool_index = ipid;
3836 cache_ipmap(session[i].ip, i); // Fix the ip map.
3837 }
3838 }
3839
3840 //
3841 // Fix the address pool to match a changed session.
3842 // (usually when the master sends us an update).
3843 static void fix_address_pool(int sid)
3844 {
3845 int ipid;
3846
3847 ipid = session[sid].ip_pool_index;
3848
3849 if (ipid > ip_pool_size)
3850 return; // Ignore it. rebuild_address_pool will fix it up.
3851
3852 if (ip_address_pool[ipid].address != session[sid].ip)
3853 return; // Just ignore it. rebuild_address_pool will take care of it.
3854
3855 ip_address_pool[ipid].assigned = 1;
3856 ip_address_pool[ipid].session = sid;
3857 ip_address_pool[ipid].last = time_now;
3858 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3859 }
3860
3861 //
3862 // Add a block of addresses to the IP pool to hand out.
3863 //
3864 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3865 {
3866 int i;
3867 if (mask == 0)
3868 mask = 0xffffffff; // Host route only.
3869
3870 addr &= mask;
3871
3872 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3873 return ;
3874
3875 for (i = addr ;(i & mask) == addr; ++i)
3876 {
3877 if ((i & 0xff) == 0 || (i&0xff) == 255)
3878 continue; // Skip 0 and broadcast addresses.
3879
3880 ip_address_pool[ip_pool_size].address = i;
3881 ip_address_pool[ip_pool_size].assigned = 0;
3882 ++ip_pool_size;
3883 if (ip_pool_size >= MAXIPPOOL)
3884 {
3885 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3886 return;
3887 }
3888 }
3889 }
3890
3891 // Initialize the IP address pool
3892 static void initippool()
3893 {
3894 FILE *f;
3895 char *p;
3896 char buf[4096];
3897 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3898
3899 if (!(f = fopen(IPPOOLFILE, "r")))
3900 {
3901 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3902 exit(1);
3903 }
3904
3905 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3906 {
3907 char *pool = buf;
3908 buf[4095] = 0; // Force it to be zero terminated/
3909
3910 if (*buf == '#' || *buf == '\n')
3911 continue; // Skip comments / blank lines
3912 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3913 if ((p = (char *)strchr(buf, ':')))
3914 {
3915 in_addr_t src;
3916 *p = '\0';
3917 src = inet_addr(buf);
3918 if (src == INADDR_NONE)
3919 {
3920 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3921 exit(1);
3922 }
3923 // This entry is for a specific IP only
3924 if (src != config->bind_address)
3925 continue;
3926 *p = ':';
3927 pool = p+1;
3928 }
3929 if ((p = (char *)strchr(pool, '/')))
3930 {
3931 // It's a range
3932 int numbits = 0;
3933 in_addr_t start = 0, mask = 0;
3934
3935 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3936 *p++ = 0;
3937 if (!*p || !(numbits = atoi(p)))
3938 {
3939 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3940 continue;
3941 }
3942 start = ntohl(inet_addr(pool));
3943 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3944
3945 // Add a static route for this pool
3946 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3947 fmtaddr(htonl(start), 0), 32 + mask);
3948
3949 routeset(0, start, mask, 0, 1);
3950
3951 add_to_ip_pool(start, mask);
3952 }
3953 else
3954 {
3955 // It's a single ip address
3956 add_to_ip_pool(inet_addr(pool), 0);
3957 }
3958 }
3959 fclose(f);
3960 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3961 }
3962
3963 void snoop_send_packet(uint8_t *packet, uint16_t size, in_addr_t destination, uint16_t port)
3964 {
3965 struct sockaddr_in snoop_addr = {0};
3966 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3967 return;
3968
3969 snoop_addr.sin_family = AF_INET;
3970 snoop_addr.sin_addr.s_addr = destination;
3971 snoop_addr.sin_port = ntohs(port);
3972
3973 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3974 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3975 htons(snoop_addr.sin_port));
3976
3977 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3978 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
3979
3980 STAT(packets_snooped);
3981 }
3982
3983 static int dump_session(FILE **f, sessiont *s)
3984 {
3985 if (!s->opened || !s->ip || !(s->cin_delta || s->cout_delta) || !*s->user || s->walled_garden)
3986 return 1;
3987
3988 if (!*f)
3989 {
3990 char filename[1024];
3991 char timestr[64];
3992 time_t now = time(NULL);
3993
3994 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
3995 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
3996
3997 if (!(*f = fopen(filename, "w")))
3998 {
3999 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
4000 return 0;
4001 }
4002
4003 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
4004 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
4005 "# host: %s\n"
4006 "# endpoint: %s\n"
4007 "# time: %ld\n"
4008 "# uptime: %ld\n"
4009 "# format: username ip qos uptxoctets downrxoctets\n",
4010 hostname,
4011 fmtaddr(config->bind_address ? config->bind_address : my_address, 0),
4012 now,
4013 now - basetime);
4014 }
4015
4016 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
4017 fprintf(*f, "%s %s %d %u %u\n",
4018 s->user, // username
4019 fmtaddr(htonl(s->ip), 0), // ip
4020 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
4021 (uint32_t) s->cin_delta, // uptxoctets
4022 (uint32_t) s->cout_delta); // downrxoctets
4023
4024 s->cin_delta = s->cout_delta = 0;
4025
4026 return 1;
4027 }
4028
4029 static void dump_acct_info(int all)
4030 {
4031 int i;
4032 FILE *f = NULL;
4033
4034
4035 CSTAT(dump_acct_info);
4036
4037 if (shut_acct_n)
4038 {
4039 for (i = 0; i < shut_acct_n; i++)
4040 dump_session(&f, &shut_acct[i]);
4041
4042 shut_acct_n = 0;
4043 }
4044
4045 if (all)
4046 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4047 dump_session(&f, &session[i]);
4048
4049 if (f)
4050 fclose(f);
4051 }
4052
4053 // Main program
4054 int main(int argc, char *argv[])
4055 {
4056 int i;
4057 int optdebug = 0;
4058 char *optconfig = CONFIGFILE;
4059
4060 time(&basetime); // start clock
4061
4062 // scan args
4063 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
4064 {
4065 switch (i)
4066 {
4067 case 'd':
4068 if (fork()) exit(0);
4069 setsid();
4070 freopen("/dev/null", "r", stdin);
4071 freopen("/dev/null", "w", stdout);
4072 freopen("/dev/null", "w", stderr);
4073 break;
4074 case 'v':
4075 optdebug++;
4076 break;
4077 case 'c':
4078 optconfig = optarg;
4079 break;
4080 case 'h':
4081 snprintf(hostname, sizeof(hostname), "%s", optarg);
4082 break;
4083 default:
4084 printf("Args are:\n"
4085 "\t-d\t\tDetach from terminal\n"
4086 "\t-c <file>\tConfig file\n"
4087 "\t-h <hostname>\tForce hostname\n"
4088 "\t-v\t\tDebug\n");
4089
4090 return (0);
4091 break;
4092 }
4093 }
4094
4095 // Start the timer routine off
4096 time(&time_now);
4097 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
4098
4099 initplugins();
4100 initdata(optdebug, optconfig);
4101
4102 init_cli(hostname);
4103 read_config_file();
4104 update_config();
4105 init_tbf(config->num_tbfs);
4106
4107 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
4108 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
4109 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
4110 {
4111 struct rlimit rlim;
4112 rlim.rlim_cur = RLIM_INFINITY;
4113 rlim.rlim_max = RLIM_INFINITY;
4114 // Remove the maximum core size
4115 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
4116 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
4117
4118 // Make core dumps go to /tmp
4119 chdir("/tmp");
4120 }
4121
4122 if (config->scheduler_fifo)
4123 {
4124 int ret;
4125 struct sched_param params = {0};
4126 params.sched_priority = 1;
4127
4128 if (get_nprocs() < 2)
4129 {
4130 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
4131 config->scheduler_fifo = 0;
4132 }
4133 else
4134 {
4135 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
4136 {
4137 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
4138 }
4139 else
4140 {
4141 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
4142 config->scheduler_fifo = 0;
4143 }
4144 }
4145 }
4146
4147 /* Set up the cluster communications port. */
4148 if (cluster_init() < 0)
4149 exit(1);
4150
4151 inittun();
4152 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
4153
4154 initudp();
4155 initrad();
4156 initippool();
4157
4158 // seed prng
4159 {
4160 unsigned seed = time_now ^ getpid();
4161 LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
4162 srand(seed);
4163 }
4164
4165 signal(SIGHUP, sighup_handler);
4166 signal(SIGCHLD, sigchild_handler);
4167 signal(SIGTERM, shutdown_handler);
4168 signal(SIGINT, shutdown_handler);
4169 signal(SIGQUIT, shutdown_handler);
4170
4171 // Prevent us from getting paged out
4172 if (config->lock_pages)
4173 {
4174 if (!mlockall(MCL_CURRENT))
4175 LOG(1, 0, 0, "Locking pages into memory\n");
4176 else
4177 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
4178 }
4179
4180 // Drop privileges here
4181 if (config->target_uid > 0 && geteuid() == 0)
4182 setuid(config->target_uid);
4183
4184 mainloop();
4185
4186 /* remove plugins (so cleanup code gets run) */
4187 plugins_done();
4188
4189 // Remove the PID file if we wrote it
4190 if (config->wrote_pid && *config->pid_file == '/')
4191 unlink(config->pid_file);
4192
4193 /* kill CLI children */
4194 signal(SIGTERM, SIG_IGN);
4195 kill(0, SIGTERM);
4196 return 0;
4197 }
4198
4199 static void sighup_handler(int sig)
4200 {
4201 main_reload++;
4202 }
4203
4204 static void shutdown_handler(int sig)
4205 {
4206 main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
4207 }
4208
4209 static void sigchild_handler(int sig)
4210 {
4211 while (waitpid(-1, NULL, WNOHANG) > 0)
4212 ;
4213 }
4214
4215 static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response)
4216 {
4217 MD5_CTX ctx;
4218 *challenge_response = NULL;
4219
4220 if (!*config->l2tp_secret)
4221 {
4222 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
4223 return;
4224 }
4225
4226 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
4227
4228 *challenge_response = calloc(17, 1);
4229
4230 MD5_Init(&ctx);
4231 MD5_Update(&ctx, &id, 1);
4232 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
4233 MD5_Update(&ctx, challenge, challenge_length);
4234 MD5_Final(*challenge_response, &ctx);
4235
4236 return;
4237 }
4238
4239 static int facility_value(char *name)
4240 {
4241 int i;
4242 for (i = 0; facilitynames[i].c_name; i++)
4243 {
4244 if (strcmp(facilitynames[i].c_name, name) == 0)
4245 return facilitynames[i].c_val;
4246 }
4247 return 0;
4248 }
4249
4250 static void update_config()
4251 {
4252 int i;
4253 char *p;
4254 static int timeout = 0;
4255 static int interval = 0;
4256
4257 // Update logging
4258 closelog();
4259 syslog_log = 0;
4260 if (log_stream)
4261 {
4262 if (log_stream != stderr)
4263 fclose(log_stream);
4264
4265 log_stream = NULL;
4266 }
4267
4268 if (*config->log_filename)
4269 {
4270 if (strstr(config->log_filename, "syslog:") == config->log_filename)
4271 {
4272 char *p = config->log_filename + 7;
4273 if (*p)
4274 {
4275 openlog("l2tpns", LOG_PID, facility_value(p));
4276 syslog_log = 1;
4277 }
4278 }
4279 else if (strchr(config->log_filename, '/') == config->log_filename)
4280 {
4281 if ((log_stream = fopen((char *)(config->log_filename), "a")))
4282 {
4283 fseek(log_stream, 0, SEEK_END);
4284 setbuf(log_stream, NULL);
4285 }
4286 else
4287 {
4288 log_stream = stderr;
4289 setbuf(log_stream, NULL);
4290 }
4291 }
4292 }
4293 else
4294 {
4295 log_stream = stderr;
4296 setbuf(log_stream, NULL);
4297 }
4298
4299 #define L2TP_HDRS (20+8+6+4) // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
4300 #define TCP_HDRS (20+20) // TCP encapsulation: ip + tcp
4301
4302 if (config->l2tp_mtu <= 0) config->l2tp_mtu = PPPMTU;
4303 else if (config->l2tp_mtu < MINMTU) config->l2tp_mtu = MINMTU;
4304 else if (config->l2tp_mtu > MAXMTU) config->l2tp_mtu = MAXMTU;
4305
4306 // reset MRU/MSS globals
4307 MRU = config->l2tp_mtu - L2TP_HDRS;
4308 MSS = MRU - TCP_HDRS;
4309
4310 // Update radius
4311 config->numradiusservers = 0;
4312 for (i = 0; i < MAXRADSERVER; i++)
4313 if (config->radiusserver[i])
4314 {
4315 config->numradiusservers++;
4316 // Set radius port: if not set, take the port from the
4317 // first radius server. For the first radius server,
4318 // take the #defined default value from l2tpns.h
4319
4320 // test twice, In case someone works with
4321 // a secondary radius server without defining
4322 // a primary one, this will work even then.
4323 if (i > 0 && !config->radiusport[i])
4324 config->radiusport[i] = config->radiusport[i-1];
4325 if (!config->radiusport[i])
4326 config->radiusport[i] = RADPORT;
4327 }
4328
4329 if (!config->numradiusservers)
4330 LOG(0, 0, 0, "No RADIUS servers defined!\n");
4331
4332 // parse radius_authtypes_s
4333 config->radius_authtypes = config->radius_authprefer = 0;
4334 p = config->radius_authtypes_s;
4335 while (p && *p)
4336 {
4337 char *s = strpbrk(p, " \t,");
4338 int type = 0;
4339
4340 if (s)
4341 {
4342 *s++ = 0;
4343 while (*s == ' ' || *s == '\t')
4344 s++;
4345
4346 if (!*s)
4347 s = 0;
4348 }
4349
4350 if (!strncasecmp("chap", p, strlen(p)))
4351 type = AUTHCHAP;
4352 else if (!strncasecmp("pap", p, strlen(p)))
4353 type = AUTHPAP;
4354 else
4355 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
4356
4357 config->radius_authtypes |= type;
4358 if (!config->radius_authprefer)
4359 config->radius_authprefer = type;
4360
4361 p = s;
4362 }
4363
4364 if (!config->radius_authtypes)
4365 {
4366 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
4367 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
4368 }
4369
4370 // normalise radius_authtypes_s
4371 if (config->radius_authprefer == AUTHPAP)
4372 {
4373 strcpy(config->radius_authtypes_s, "pap");
4374 if (config->radius_authtypes & AUTHCHAP)
4375 strcat(config->radius_authtypes_s, ", chap");
4376 }
4377 else
4378 {
4379 strcpy(config->radius_authtypes_s, "chap");
4380 if (config->radius_authtypes & AUTHPAP)
4381 strcat(config->radius_authtypes_s, ", pap");
4382 }
4383
4384 if (!config->radius_dae_port)
4385 config->radius_dae_port = DAEPORT;
4386
4387 // re-initialise the random number source
4388 initrandom(config->random_device);
4389
4390 // Update plugins
4391 for (i = 0; i < MAXPLUGINS; i++)
4392 {
4393 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4394 continue;
4395
4396 if (*config->plugins[i])
4397 {
4398 // Plugin added
4399 add_plugin(config->plugins[i]);
4400 }
4401 else if (*config->old_plugins[i])
4402 {
4403 // Plugin removed
4404 remove_plugin(config->old_plugins[i]);
4405 }
4406 }
4407
4408 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4409 if (!config->multi_read_count) config->multi_read_count = 10;
4410 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4411 if (!*config->cluster_interface)
4412 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4413
4414 if (!config->cluster_hb_interval)
4415 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4416
4417 if (!config->cluster_hb_timeout)
4418 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4419
4420 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4421 {
4422 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4423 // late, ensure we're sufficiently larger than that
4424 int t = 4 * config->cluster_hb_interval + 11;
4425
4426 if (config->cluster_hb_timeout < t)
4427 {
4428 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4429 config->cluster_hb_timeout = t;
4430 }
4431
4432 // Push timing changes to the slaves immediately if we're the master
4433 if (config->cluster_iam_master)
4434 cluster_heartbeat();
4435
4436 interval = config->cluster_hb_interval;
4437 timeout = config->cluster_hb_timeout;
4438 }
4439
4440 // Write PID file
4441 if (*config->pid_file == '/' && !config->wrote_pid)
4442 {
4443 FILE *f;
4444 if ((f = fopen(config->pid_file, "w")))
4445 {
4446 fprintf(f, "%d\n", getpid());
4447 fclose(f);
4448 config->wrote_pid = 1;
4449 }
4450 else
4451 {
4452 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4453 }
4454 }
4455 }
4456
4457 static void read_config_file()
4458 {
4459 FILE *f;
4460
4461 if (!config->config_file) return;
4462 if (!(f = fopen(config->config_file, "r")))
4463 {
4464 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4465 return;
4466 }
4467
4468 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4469 cli_do_file(f);
4470 LOG(3, 0, 0, "Done reading config file\n");
4471 fclose(f);
4472 }
4473
4474 int sessionsetup(sessionidt s, tunnelidt t)
4475 {
4476 // A session now exists, set it up
4477 in_addr_t ip;
4478 char *user;
4479 sessionidt i;
4480 int r;
4481
4482 CSTAT(sessionsetup);
4483
4484 LOG(3, s, t, "Doing session setup for session\n");
4485
4486 if (!session[s].ip)
4487 {
4488 assign_ip_address(s);
4489 if (!session[s].ip)
4490 {
4491 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4492 sessionshutdown(s, "No IP addresses available.", 2, 7); // try another
4493 return 0;
4494 }
4495 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4496 fmtaddr(htonl(session[s].ip), 0));
4497 }
4498
4499
4500 // Make sure this is right
4501 session[s].tunnel = t;
4502
4503 // zap old sessions with same IP and/or username
4504 // Don't kill gardened sessions - doing so leads to a DoS
4505 // from someone who doesn't need to know the password
4506 {
4507 ip = session[s].ip;
4508 user = session[s].user;
4509 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4510 {
4511 if (i == s) continue;
4512 if (!session[s].opened) continue;
4513 if (ip == session[i].ip)
4514 {
4515 sessionkill(i, "Duplicate IP address");
4516 continue;
4517 }
4518
4519 if (config->allow_duplicate_users) continue;
4520 if (session[s].walled_garden || session[i].walled_garden) continue;
4521 if (!strcasecmp(user, session[i].user))
4522 sessionkill(i, "Duplicate session for users");
4523 }
4524 }
4525
4526 {
4527 int routed = 0;
4528
4529 // Add the route for this session.
4530 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4531 {
4532 if ((session[s].ip & session[s].route[r].mask) ==
4533 (session[s].route[r].ip & session[s].route[r].mask))
4534 routed++;
4535
4536 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4537 }
4538
4539 // Static IPs need to be routed if not already
4540 // convered by a Framed-Route. Anything else is part
4541 // of the IP address pool and is already routed, it
4542 // just needs to be added to the IP cache.
4543 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4544 if (session[s].ip_pool_index == -1) // static ip
4545 {
4546 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4547 }
4548 else
4549 cache_ipmap(session[s].ip, s);
4550 }
4551
4552 sess_local[s].lcp_authtype = 0; // RADIUS authentication complete
4553 lcp_open(s, t); // transition to Network phase and send initial IPCP
4554
4555 // Run the plugin's against this new session.
4556 {
4557 struct param_new_session data = { &tunnel[t], &session[s] };
4558 run_plugins(PLUGIN_NEW_SESSION, &data);
4559 }
4560
4561 // Allocate TBFs if throttled
4562 if (session[s].throttle_in || session[s].throttle_out)
4563 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4564
4565 session[s].last_packet = time_now;
4566
4567 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4568 fmtaddr(htonl(session[s].ip), 0),
4569 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4570
4571 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4572
4573 return 1; // RADIUS OK and IP allocated, done...
4574 }
4575
4576 //
4577 // This session just got dropped on us by the master or something.
4578 // Make sure our tables up up to date...
4579 //
4580 int load_session(sessionidt s, sessiont *new)
4581 {
4582 int i;
4583 int newip = 0;
4584
4585 // Sanity checks.
4586 if (new->ip_pool_index >= MAXIPPOOL ||
4587 new->tunnel >= MAXTUNNEL)
4588 {
4589 LOG(0, s, 0, "Strange session update received!\n");
4590 // FIXME! What to do here?
4591 return 0;
4592 }
4593
4594 //
4595 // Ok. All sanity checks passed. Now we're committed to
4596 // loading the new session.
4597 //
4598
4599 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4600
4601 // See if routes/ip cache need updating
4602 if (new->ip != session[s].ip)
4603 newip++;
4604
4605 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4606 if (new->route[i].ip != session[s].route[i].ip ||
4607 new->route[i].mask != session[s].route[i].mask)
4608 newip++;
4609
4610 // needs update
4611 if (newip)
4612 {
4613 int routed = 0;
4614
4615 // remove old routes...
4616 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4617 {
4618 if ((session[s].ip & session[s].route[i].mask) ==
4619 (session[s].route[i].ip & session[s].route[i].mask))
4620 routed++;
4621
4622 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4623 }
4624
4625 // ...ip
4626 if (session[s].ip)
4627 {
4628 if (session[s].ip_pool_index == -1) // static IP
4629 {
4630 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4631 }
4632 else // It's part of the IP pool, remove it manually.
4633 uncache_ipmap(session[s].ip);
4634 }
4635
4636 routed = 0;
4637
4638 // add new routes...
4639 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4640 {
4641 if ((new->ip & new->route[i].mask) ==
4642 (new->route[i].ip & new->route[i].mask))
4643 routed++;
4644
4645 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4646 }
4647
4648 // ...ip
4649 if (new->ip)
4650 {
4651 // If there's a new one, add it.
4652 if (new->ip_pool_index == -1)
4653 {
4654 if (!routed) routeset(s, new->ip, 0, 0, 1);
4655 }
4656 else
4657 cache_ipmap(new->ip, s);
4658 }
4659 }
4660
4661 // check v6 routing
4662 if (new->ipv6prefixlen && new->ppp.ipv6cp == Opened && session[s].ppp.ipv6cp != Opened)
4663 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4664
4665 // check filters
4666 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4667 {
4668 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4669 new->filter_in = 0;
4670 }
4671
4672 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4673 {
4674 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4675 new->filter_out = 0;
4676 }
4677
4678 if (new->filter_in != session[s].filter_in)
4679 {
4680 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4681 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4682 }
4683
4684 if (new->filter_out != session[s].filter_out)
4685 {
4686 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4687 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4688 }
4689
4690 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4691 // for walking the sessions to forward byte counts to the master.
4692 config->cluster_highest_sessionid = s;
4693
4694 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4695
4696 // Do fixups into address pool.
4697 if (new->ip_pool_index != -1)
4698 fix_address_pool(s);
4699
4700 return 1;
4701 }
4702
4703 static void initplugins()
4704 {
4705 int i;
4706
4707 loaded_plugins = ll_init();
4708 // Initialize the plugins to nothing
4709 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4710 plugins[i] = ll_init();
4711 }
4712
4713 static void *open_plugin(char *plugin_name, int load)
4714 {
4715 char path[256] = "";
4716
4717 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4718 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4719 return dlopen(path, RTLD_NOW);
4720 }
4721
4722 // plugin callback to get a config value
4723 static void *getconfig(char *key, enum config_typet type)
4724 {
4725 int i;
4726
4727 for (i = 0; config_values[i].key; i++)
4728 {
4729 if (!strcmp(config_values[i].key, key))
4730 {
4731 if (config_values[i].type == type)
4732 return ((void *) config) + config_values[i].offset;
4733
4734 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4735 key, type, config_values[i].type);
4736
4737 return 0;
4738 }
4739 }
4740
4741 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4742 return 0;
4743 }
4744
4745 static int add_plugin(char *plugin_name)
4746 {
4747 static struct pluginfuncs funcs = {
4748 _log,
4749 _log_hex,
4750 fmtaddr,
4751 sessionbyuser,
4752 sessiontbysessionidt,
4753 sessionidtbysessiont,
4754 radiusnew,
4755 radiussend,
4756 getconfig,
4757 sessionshutdown,
4758 sessionkill,
4759 throttle_session,
4760 cluster_send_session,
4761 };
4762
4763 void *p = open_plugin(plugin_name, 1);
4764 int (*initfunc)(struct pluginfuncs *);
4765 int i;
4766
4767 if (!p)
4768 {
4769 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4770 return -1;
4771 }
4772
4773 if (ll_contains(loaded_plugins, p))
4774 {
4775 dlclose(p);
4776 return 0; // already loaded
4777 }
4778
4779 {
4780 int *v = dlsym(p, "plugin_api_version");
4781 if (!v || *v != PLUGIN_API_VERSION)
4782 {
4783 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4784 dlclose(p);
4785 return -1;
4786 }
4787 }
4788
4789 if ((initfunc = dlsym(p, "plugin_init")))
4790 {
4791 if (!initfunc(&funcs))
4792 {
4793 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4794 dlclose(p);
4795 return -1;
4796 }
4797 }
4798
4799 ll_push(loaded_plugins, p);
4800
4801 for (i = 0; i < max_plugin_functions; i++)
4802 {
4803 void *x;
4804 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4805 {
4806 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4807 ll_push(plugins[i], x);
4808 }
4809 }
4810
4811 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4812 return 1;
4813 }
4814
4815 static void run_plugin_done(void *plugin)
4816 {
4817 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4818
4819 if (donefunc)
4820 donefunc();
4821 }
4822
4823 static int remove_plugin(char *plugin_name)
4824 {
4825 void *p = open_plugin(plugin_name, 0);
4826 int loaded = 0;
4827
4828 if (!p)
4829 return -1;
4830
4831 if (ll_contains(loaded_plugins, p))
4832 {
4833 int i;
4834 for (i = 0; i < max_plugin_functions; i++)
4835 {
4836 void *x;
4837 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4838 ll_delete(plugins[i], x);
4839 }
4840
4841 ll_delete(loaded_plugins, p);
4842 run_plugin_done(p);
4843 loaded = 1;
4844 }
4845
4846 dlclose(p);
4847 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4848 return loaded;
4849 }
4850
4851 int run_plugins(int plugin_type, void *data)
4852 {
4853 int (*func)(void *data);
4854
4855 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4856 return PLUGIN_RET_ERROR;
4857
4858 ll_reset(plugins[plugin_type]);
4859 while ((func = ll_next(plugins[plugin_type])))
4860 {
4861 int r = func(data);
4862
4863 if (r != PLUGIN_RET_OK)
4864 return r; // stop here
4865 }
4866
4867 return PLUGIN_RET_OK;
4868 }
4869
4870 static void plugins_done()
4871 {
4872 void *p;
4873
4874 ll_reset(loaded_plugins);
4875 while ((p = ll_next(loaded_plugins)))
4876 run_plugin_done(p);
4877 }
4878
4879 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen)
4880 {
4881 struct nsctl request;
4882 struct nsctl response;
4883 int type = unpack_control(&request, buf, len);
4884 int r;
4885 void *p;
4886
4887 if (log_stream && config->debug >= 4)
4888 {
4889 if (type < 0)
4890 {
4891 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4892 fmtaddr(addr->sin_addr.s_addr, 0), type);
4893 }
4894 else
4895 {
4896 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4897 dump_control(&request, log_stream);
4898 }
4899 }
4900
4901 switch (type)
4902 {
4903 case NSCTL_REQ_LOAD:
4904 if (request.argc != 1)
4905 {
4906 response.type = NSCTL_RES_ERR;
4907 response.argc = 1;
4908 response.argv[0] = "name of plugin required";
4909 }
4910 else if ((r = add_plugin(request.argv[0])) < 1)
4911 {
4912 response.type = NSCTL_RES_ERR;
4913 response.argc = 1;
4914 response.argv[0] = !r
4915 ? "plugin already loaded"
4916 : "error loading plugin";
4917 }
4918 else
4919 {
4920 response.type = NSCTL_RES_OK;
4921 response.argc = 0;
4922 }
4923
4924 break;
4925
4926 case NSCTL_REQ_UNLOAD:
4927 if (request.argc != 1)
4928 {
4929 response.type = NSCTL_RES_ERR;
4930 response.argc = 1;
4931 response.argv[0] = "name of plugin required";
4932 }
4933 else if ((r = remove_plugin(request.argv[0])) < 1)
4934 {
4935 response.type = NSCTL_RES_ERR;
4936 response.argc = 1;
4937 response.argv[0] = !r
4938 ? "plugin not loaded"
4939 : "plugin not found";
4940 }
4941 else
4942 {
4943 response.type = NSCTL_RES_OK;
4944 response.argc = 0;
4945 }
4946
4947 break;
4948
4949 case NSCTL_REQ_HELP:
4950 response.type = NSCTL_RES_OK;
4951 response.argc = 0;
4952
4953 ll_reset(loaded_plugins);
4954 while ((p = ll_next(loaded_plugins)))
4955 {
4956 char **help = dlsym(p, "plugin_control_help");
4957 while (response.argc < 0xff && help && *help)
4958 response.argv[response.argc++] = *help++;
4959 }
4960
4961 break;
4962
4963 case NSCTL_REQ_CONTROL:
4964 {
4965 struct param_control param = {
4966 config->cluster_iam_master,
4967 request.argc,
4968 request.argv,
4969 0,
4970 NULL,
4971 };
4972
4973 int r = run_plugins(PLUGIN_CONTROL, &param);
4974
4975 if (r == PLUGIN_RET_ERROR)
4976 {
4977 response.type = NSCTL_RES_ERR;
4978 response.argc = 1;
4979 response.argv[0] = param.additional
4980 ? param.additional
4981 : "error returned by plugin";
4982 }
4983 else if (r == PLUGIN_RET_NOTMASTER)
4984 {
4985 static char msg[] = "must be run on master: 000.000.000.000";
4986
4987 response.type = NSCTL_RES_ERR;
4988 response.argc = 1;
4989 if (config->cluster_master_address)
4990 {
4991 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
4992 response.argv[0] = msg;
4993 }
4994 else
4995 {
4996 response.argv[0] = "must be run on master: none elected";
4997 }
4998 }
4999 else if (!(param.response & NSCTL_RESPONSE))
5000 {
5001 response.type = NSCTL_RES_ERR;
5002 response.argc = 1;
5003 response.argv[0] = param.response
5004 ? "unrecognised response value from plugin"
5005 : "unhandled action";
5006 }
5007 else
5008 {
5009 response.type = param.response;
5010 response.argc = 0;
5011 if (param.additional)
5012 {
5013 response.argc = 1;
5014 response.argv[0] = param.additional;
5015 }
5016 }
5017 }
5018
5019 break;
5020
5021 default:
5022 response.type = NSCTL_RES_ERR;
5023 response.argc = 1;
5024 response.argv[0] = "error unpacking control packet";
5025 }
5026
5027 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
5028 if (!buf)
5029 {
5030 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
5031 return;
5032 }
5033
5034 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
5035 if (r > 0)
5036 {
5037 sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
5038 if (log_stream && config->debug >= 4)
5039 {
5040 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
5041 dump_control(&response, log_stream);
5042 }
5043 }
5044 else
5045 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
5046 fmtaddr(addr->sin_addr.s_addr, 0), r);
5047
5048 free(buf);
5049 }
5050
5051 static tunnelidt new_tunnel()
5052 {
5053 tunnelidt i;
5054 for (i = 1; i < MAXTUNNEL; i++)
5055 {
5056 if (tunnel[i].state == TUNNELFREE)
5057 {
5058 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
5059 if (i > config->cluster_highest_tunnelid)
5060 config->cluster_highest_tunnelid = i;
5061 return i;
5062 }
5063 }
5064 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
5065 return 0;
5066 }
5067
5068 //
5069 // We're becoming the master. Do any required setup..
5070 //
5071 // This is principally telling all the plugins that we're
5072 // now a master, and telling them about all the sessions
5073 // that are active too..
5074 //
5075 void become_master(void)
5076 {
5077 int s, i;
5078 static struct event_data d[RADIUS_FDS];
5079 struct epoll_event e;
5080
5081 run_plugins(PLUGIN_BECOME_MASTER, NULL);
5082
5083 // running a bunch of iptables commands is slow and can cause
5084 // the master to drop tunnels on takeover--kludge around the
5085 // problem by forking for the moment (note: race)
5086 if (!fork_and_close())
5087 {
5088 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5089 {
5090 if (!session[s].opened) // Not an in-use session.
5091 continue;
5092
5093 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
5094 }
5095 exit(0);
5096 }
5097
5098 // add radius fds
5099 e.events = EPOLLIN;
5100 for (i = 0; i < RADIUS_FDS; i++)
5101 {
5102 d[i].type = FD_TYPE_RADIUS;
5103 d[i].index = i;
5104 e.data.ptr = &d[i];
5105
5106 epoll_ctl(epollfd, EPOLL_CTL_ADD, radfds[i], &e);
5107 }
5108 }
5109
5110 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
5111 {
5112 int s, i;
5113 int count = 0;
5114 int buckets[64];
5115
5116 if (CLI_HELP_REQUESTED)
5117 return CLI_HELP_NO_ARGS;
5118
5119 time(&time_now);
5120 for (i = 0; i < 64;++i) buckets[i] = 0;
5121
5122 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5123 {
5124 int idle;
5125 if (!session[s].opened)
5126 continue;
5127
5128 idle = time_now - session[s].last_packet;
5129 idle /= 5 ; // In multiples of 5 seconds.
5130 if (idle < 0)
5131 idle = 0;
5132 if (idle > 63)
5133 idle = 63;
5134
5135 ++count;
5136 ++buckets[idle];
5137 }
5138
5139 for (i = 0; i < 63; ++i)
5140 {
5141 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
5142 }
5143 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
5144 cli_print(cli, "%d total sessions open.", count);
5145 return CLI_OK;
5146 }
5147
5148 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
5149 {
5150 int s, i;
5151 int count = 0;
5152 int buckets[64];
5153
5154 if (CLI_HELP_REQUESTED)
5155 return CLI_HELP_NO_ARGS;
5156
5157 time(&time_now);
5158 for (i = 0; i < 64;++i) buckets[i] = 0;
5159
5160 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
5161 {
5162 int open = 0, d;
5163 if (!session[s].opened)
5164 continue;
5165
5166 d = time_now - session[s].opened;
5167 if (d < 0)
5168 d = 0;
5169 while (d > 1 && open < 32)
5170 {
5171 ++open;
5172 d >>= 1; // half.
5173 }
5174 ++count;
5175 ++buckets[open];
5176 }
5177
5178 s = 1;
5179 for (i = 0; i < 30; ++i)
5180 {
5181 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
5182 s <<= 1;
5183 }
5184 cli_print(cli, "%d total sessions open.", count);
5185 return CLI_OK;
5186 }
5187
5188 /* Unhide an avp.
5189 *
5190 * This unencodes the AVP using the L2TP secret and the previously
5191 * stored random vector. It overwrites the hidden data with the
5192 * unhidden AVP subformat.
5193 */
5194 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
5195 {
5196 MD5_CTX ctx;
5197 uint8_t digest[16];
5198 uint8_t *last;
5199 size_t d = 0;
5200 uint16_t m = htons(type);
5201
5202 // Compute initial pad
5203 MD5_Init(&ctx);
5204 MD5_Update(&ctx, (unsigned char *) &m, 2);
5205 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
5206 MD5_Update(&ctx, vector, vec_len);
5207 MD5_Final(digest, &ctx);
5208
5209 // pointer to last decoded 16 octets
5210 last = value;
5211
5212 while (len > 0)
5213 {
5214 // calculate a new pad based on the last decoded block
5215 if (d >= sizeof(digest))
5216 {
5217 MD5_Init(&ctx);
5218 MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
5219 MD5_Update(&ctx, last, sizeof(digest));
5220 MD5_Final(digest, &ctx);
5221
5222 d = 0;
5223 last = value;
5224 }
5225
5226 *value++ ^= digest[d++];
5227 len--;
5228 }
5229 }
5230
5231 int find_filter(char const *name, size_t len)
5232 {
5233 int free = -1;
5234 int i;
5235
5236 for (i = 0; i < MAXFILTER; i++)
5237 {
5238 if (!*ip_filters[i].name)
5239 {
5240 if (free < 0)
5241 free = i;
5242
5243 continue;
5244 }
5245
5246 if (strlen(ip_filters[i].name) != len)
5247 continue;
5248
5249 if (!strncmp(ip_filters[i].name, name, len))
5250 return i;
5251 }
5252
5253 return free;
5254 }
5255
5256 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
5257 {
5258 switch (p->op)
5259 {
5260 case FILTER_PORT_OP_EQ: return port == p->port;
5261 case FILTER_PORT_OP_NEQ: return port != p->port;
5262 case FILTER_PORT_OP_GT: return port > p->port;
5263 case FILTER_PORT_OP_LT: return port < p->port;
5264 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
5265 }
5266
5267 return 0;
5268 }
5269
5270 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
5271 {
5272 switch (op)
5273 {
5274 case FILTER_FLAG_OP_ANY:
5275 return (flags & sflags) || (~flags & cflags);
5276
5277 case FILTER_FLAG_OP_ALL:
5278 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
5279
5280 case FILTER_FLAG_OP_EST:
5281 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
5282 }
5283
5284 return 0;
5285 }
5286
5287 int ip_filter(uint8_t *buf, int len, uint8_t filter)
5288 {
5289 uint16_t frag_offset;
5290 uint8_t proto;
5291 in_addr_t src_ip;
5292 in_addr_t dst_ip;
5293 uint16_t src_port = 0;
5294 uint16_t dst_port = 0;
5295 uint8_t flags = 0;
5296 ip_filter_rulet *rule;
5297
5298 if (len < 20) // up to end of destination address
5299 return 0;
5300
5301 if ((*buf >> 4) != 4) // IPv4
5302 return 0;
5303
5304 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
5305 proto = buf[9];
5306 src_ip = *(in_addr_t *) (buf + 12);
5307 dst_ip = *(in_addr_t *) (buf + 16);
5308
5309 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
5310 {
5311 int l = (buf[0] & 0xf) * 4; // length of IP header
5312 if (len < l + 4) // ports
5313 return 0;
5314
5315 src_port = ntohs(*(uint16_t *) (buf + l));
5316 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
5317 if (proto == IPPROTO_TCP)
5318 {
5319 if (len < l + 14) // flags
5320 return 0;
5321
5322 flags = buf[l + 13] & 0x3f;
5323 }
5324 }
5325
5326 for (rule = ip_filters[filter].rules; rule->action; rule++)
5327 {
5328 if (rule->proto != IPPROTO_IP && proto != rule->proto)
5329 continue;
5330
5331 if (rule->src_wild != INADDR_BROADCAST &&
5332 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
5333 continue;
5334
5335 if (rule->dst_wild != INADDR_BROADCAST &&
5336 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
5337 continue;
5338
5339 if (frag_offset)
5340 {
5341 // layer 4 deny rules are skipped
5342 if (rule->action == FILTER_ACTION_DENY &&
5343 (rule->src_ports.op || rule->dst_ports.op || rule->tcp_flag_op))
5344 continue;
5345 }
5346 else
5347 {
5348 if (rule->frag)
5349 continue;
5350
5351 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
5352 {
5353 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
5354 continue;
5355
5356 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
5357 continue;
5358
5359 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
5360 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
5361 continue;
5362 }
5363 }
5364
5365 // matched
5366 rule->counter++;
5367 return rule->action == FILTER_ACTION_PERMIT;
5368 }
5369
5370 // default deny
5371 return 0;
5372 }