5ba7fe9996fd5ee0eb07f27de106d324797abad6
[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 1.106 2005/06/02 04:04:07 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 /* BGP */
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 snoopfd = -1; // UDP file handle for sending out intercept data
64 int *radfds = NULL; // RADIUS requests file handles
65 int ifrfd = -1; // File descriptor for routing, etc
66 int ifr6fd = -1; // File descriptor for IPv6 routing, etc
67 static int rand_fd = -1; // Random data source
68 time_t basetime = 0; // base clock
69 char hostname[1000] = ""; // us.
70 static int tunidx; // ifr_ifindex of tun device
71 static int syslog_log = 0; // are we logging to syslog
72 static FILE *log_stream = 0; // file handle for direct logging (i.e. direct into file, not via syslog).
73 extern int cluster_sockfd; // Intra-cluster communications socket.
74 uint32_t last_id = 0; // Unique ID for radius accounting
75
76 struct cli_session_actions *cli_session_actions = NULL; // Pending session changes requested by CLI
77 struct cli_tunnel_actions *cli_tunnel_actions = NULL; // Pending tunnel changes required by CLI
78
79 static void *ip_hash[256]; // Mapping from IP address to session structures.
80 struct ipv6radix {
81 int sess;
82 struct ipv6radix *branch;
83 } ipv6_hash[256]; // Mapping from IPv6 address to session structures.
84
85 // Traffic counters.
86 static uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
87 static uint32_t eth_rx = 0, eth_rx_pkt = 0;
88 uint32_t eth_tx = 0;
89
90 static uint32_t ip_pool_size = 1; // Size of the pool of addresses used for dynamic address allocation.
91 time_t time_now = 0; // Current time in seconds since epoch.
92 static char time_now_string[64] = {0}; // Current time as a string.
93 static char main_quit = 0; // True if we're in the process of exiting.
94 linked_list *loaded_plugins;
95 linked_list *plugins[MAX_PLUGIN_TYPES];
96
97 #define membersize(STRUCT, MEMBER) sizeof(((STRUCT *)0)->MEMBER)
98 #define CONFIG(NAME, MEMBER, TYPE) { NAME, offsetof(configt, MEMBER), membersize(configt, MEMBER), TYPE }
99
100 config_descriptt config_values[] = {
101 CONFIG("debug", debug, INT),
102 CONFIG("log_file", log_filename, STRING),
103 CONFIG("pid_file", pid_file, STRING),
104 CONFIG("random_device", random_device, STRING),
105 CONFIG("l2tp_secret", l2tpsecret, STRING),
106 CONFIG("primary_dns", default_dns1, IPv4),
107 CONFIG("secondary_dns", default_dns2, IPv4),
108 CONFIG("primary_radius", radiusserver[0], IPv4),
109 CONFIG("secondary_radius", radiusserver[1], IPv4),
110 CONFIG("primary_radius_port", radiusport[0], SHORT),
111 CONFIG("secondary_radius_port", radiusport[1], SHORT),
112 CONFIG("radius_accounting", radius_accounting, BOOL),
113 CONFIG("radius_interim", radius_interim, INT),
114 CONFIG("radius_secret", radiussecret, STRING),
115 CONFIG("radius_authtypes", radius_authtypes_s, STRING),
116 CONFIG("allow_duplicate_users", allow_duplicate_users, BOOL),
117 CONFIG("bind_address", bind_address, IPv4),
118 CONFIG("peer_address", peer_address, IPv4),
119 CONFIG("send_garp", send_garp, BOOL),
120 CONFIG("throttle_speed", rl_rate, UNSIGNED_LONG),
121 CONFIG("throttle_buckets", num_tbfs, INT),
122 CONFIG("accounting_dir", accounting_dir, STRING),
123 CONFIG("setuid", target_uid, INT),
124 CONFIG("dump_speed", dump_speed, BOOL),
125 CONFIG("cleanup_interval", cleanup_interval, INT),
126 CONFIG("multi_read_count", multi_read_count, INT),
127 CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
128 CONFIG("lock_pages", lock_pages, BOOL),
129 CONFIG("icmp_rate", icmp_rate, INT),
130 CONFIG("packet_limit", max_packets, INT),
131 CONFIG("cluster_address", cluster_address, IPv4),
132 CONFIG("cluster_interface", cluster_interface, STRING),
133 CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
134 CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
135 CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT),
136 CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
137 { NULL, 0, 0, 0 },
138 };
139
140 static char *plugin_functions[] = {
141 NULL,
142 "plugin_pre_auth",
143 "plugin_post_auth",
144 "plugin_packet_rx",
145 "plugin_packet_tx",
146 "plugin_timer",
147 "plugin_new_session",
148 "plugin_kill_session",
149 "plugin_control",
150 "plugin_radius_response",
151 "plugin_become_master",
152 "plugin_new_session_master",
153 };
154
155 #define max_plugin_functions (sizeof(plugin_functions) / sizeof(char *))
156
157 // Counters for shutdown sessions
158 static sessiont shut_acct[8192];
159 static sessionidt shut_acct_n = 0;
160
161 tunnelt *tunnel = NULL; // Array of tunnel structures.
162 sessiont *session = NULL; // Array of session structures.
163 sessionlocalt *sess_local = NULL; // Array of local per-session counters.
164 radiust *radius = NULL; // Array of radius structures.
165 ippoolt *ip_address_pool = NULL; // Array of dynamic IP addresses.
166 ip_filtert *ip_filters = NULL; // Array of named filters.
167 static controlt *controlfree = 0;
168 struct Tstats *_statistics = NULL;
169 #ifdef RINGBUFFER
170 struct Tringbuffer *ringbuffer = NULL;
171 #endif
172
173 static void cache_ipmap(in_addr_t ip, int s);
174 static void uncache_ipmap(in_addr_t ip);
175 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s);
176 static void free_ip_address(sessionidt s);
177 static void dump_acct_info(int all);
178 static void sighup_handler(int sig);
179 static void sigalrm_handler(int sig);
180 static void sigterm_handler(int sig);
181 static void sigquit_handler(int sig);
182 static void sigchild_handler(int sig);
183 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response);
184 static void update_config(void);
185 static void read_config_file(void);
186 static void initplugins(void);
187 static int add_plugin(char *plugin_name);
188 static int remove_plugin(char *plugin_name);
189 static void plugins_done(void);
190 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
191 static tunnelidt new_tunnel(void);
192 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
193
194 // return internal time (10ths since process startup)
195 static clockt now(void)
196 {
197 struct timeval t;
198 gettimeofday(&t, 0);
199 return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
200 }
201
202 // work out a retry time based on try number
203 // This is a straight bounded exponential backoff.
204 // Maximum re-try time is 32 seconds. (2^5).
205 clockt backoff(uint8_t try)
206 {
207 if (try > 5) try = 5; // max backoff
208 return now() + 10 * (1 << try);
209 }
210
211
212 //
213 // Log a debug message. Typically called via the LOG macro
214 //
215 void _log(int level, sessionidt s, tunnelidt t, const char *format, ...)
216 {
217 static char message[65536] = {0};
218 va_list ap;
219
220 #ifdef RINGBUFFER
221 if (ringbuffer)
222 {
223 if (++ringbuffer->tail >= RINGBUFFER_SIZE)
224 ringbuffer->tail = 0;
225 if (ringbuffer->tail == ringbuffer->head)
226 if (++ringbuffer->head >= RINGBUFFER_SIZE)
227 ringbuffer->head = 0;
228
229 ringbuffer->buffer[ringbuffer->tail].level = level;
230 ringbuffer->buffer[ringbuffer->tail].session = s;
231 ringbuffer->buffer[ringbuffer->tail].tunnel = t;
232 va_start(ap, format);
233 vsnprintf(ringbuffer->buffer[ringbuffer->tail].message, 4095, format, ap);
234 va_end(ap);
235 }
236 #endif
237
238 if (config->debug < level) return;
239
240 va_start(ap, format);
241 vsnprintf(message, sizeof(message), format, ap);
242
243 if (log_stream)
244 fprintf(log_stream, "%s %02d/%02d %s", time_now_string, t, s, message);
245 else if (syslog_log)
246 syslog(level + 2, "%02d/%02d %s", t, s, message); // We don't need LOG_EMERG or LOG_ALERT
247
248 va_end(ap);
249 }
250
251 void _log_hex(int level, const char *title, const char *data, int maxsize)
252 {
253 int i, j;
254 const uint8_t *d = (const uint8_t *) data;
255
256 if (config->debug < level) return;
257
258 // No support for _log_hex to syslog
259 if (log_stream)
260 {
261 _log(level, 0, 0, "%s (%d bytes):\n", title, maxsize);
262 setvbuf(log_stream, NULL, _IOFBF, 16384);
263
264 for (i = 0; i < maxsize; )
265 {
266 fprintf(log_stream, "%4X: ", i);
267 for (j = i; j < maxsize && j < (i + 16); j++)
268 {
269 fprintf(log_stream, "%02X ", d[j]);
270 if (j == i + 7)
271 fputs(": ", log_stream);
272 }
273
274 for (; j < i + 16; j++)
275 {
276 fputs(" ", log_stream);
277 if (j == i + 7)
278 fputs(": ", log_stream);
279 }
280
281 fputs(" ", log_stream);
282 for (j = i; j < maxsize && j < (i + 16); j++)
283 {
284 if (d[j] >= 0x20 && d[j] < 0x7f && d[j] != 0x20)
285 fputc(d[j], log_stream);
286 else
287 fputc('.', log_stream);
288
289 if (j == i + 7)
290 fputs(" ", log_stream);
291 }
292
293 i = j;
294 fputs("\n", log_stream);
295 }
296
297 fflush(log_stream);
298 setbuf(log_stream, NULL);
299 }
300 }
301
302 // initialise the random generator
303 static void initrandom(char *source)
304 {
305 static char path[sizeof(config->random_device)] = "*undefined*";
306
307 // reinitialise only if we are forced to do so or if the config has changed
308 if (source && !strncmp(path, source, sizeof(path)))
309 return;
310
311 // close previous source, if any
312 if (rand_fd >= 0) close(rand_fd);
313
314 rand_fd = -1;
315
316 if (source)
317 {
318 // register changes
319 snprintf(path, sizeof(path), "%s", source);
320
321 if (*path == '/')
322 {
323 rand_fd = open(path, O_RDONLY|O_NONBLOCK);
324 if (rand_fd < 0)
325 LOG(0, 0, 0, "Error opening the random device %s: %s\n",
326 path, strerror(errno));
327 }
328 }
329
330 // no source: seed prng
331 {
332 unsigned seed = time_now ^ getpid();
333 LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
334 srand(seed);
335 }
336 }
337
338 // fill buffer with random data
339 void random_data(uint8_t *buf, int len)
340 {
341 int n = 0;
342
343 CSTAT(random_data);
344 if (rand_fd >= 0)
345 {
346 n = read(rand_fd, buf, len);
347 if (n >= len) return;
348 if (n < 0)
349 {
350 if (errno != EAGAIN)
351 {
352 LOG(0, 0, 0, "Error reading from random source: %s\n",
353 strerror(errno));
354
355 // fall back to rand()
356 initrandom(0);
357 }
358
359 n = 0;
360 }
361 }
362
363 // append missing data
364 while (n < len)
365 // not using the low order bits from the prng stream
366 buf[n++] = (rand() >> 4) & 0xff;
367 }
368
369 // Add a route
370 //
371 // This adds it to the routing table, advertises it
372 // via BGP if enabled, and stuffs it into the
373 // 'sessionbyip' cache.
374 //
375 // 'ip' and 'mask' must be in _host_ order.
376 //
377 static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, int add)
378 {
379 struct rtentry r;
380 int i;
381
382 if (!mask) mask = 0xffffffff;
383
384 ip &= mask; // Force the ip to be the first one in the route.
385
386 memset(&r, 0, sizeof(r));
387 r.rt_dev = config->tundevice;
388 r.rt_dst.sa_family = AF_INET;
389 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(ip);
390 r.rt_gateway.sa_family = AF_INET;
391 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr) = htonl(gw);
392 r.rt_genmask.sa_family = AF_INET;
393 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
394 r.rt_flags = (RTF_UP | RTF_STATIC);
395 if (gw)
396 r.rt_flags |= RTF_GATEWAY;
397 else if (mask == 0xffffffff)
398 r.rt_flags |= RTF_HOST;
399
400 LOG(1, s, 0, "Route %s %s/%s%s%s\n", add ? "add" : "del",
401 fmtaddr(htonl(ip), 0), fmtaddr(htonl(mask), 1),
402 gw ? " via" : "", gw ? fmtaddr(htonl(gw), 2) : "");
403
404 if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0)
405 LOG(0, 0, 0, "routeset() error in ioctl: %s\n", strerror(errno));
406
407 #ifdef BGP
408 if (add)
409 bgp_add_route(htonl(ip), htonl(mask));
410 else
411 bgp_del_route(htonl(ip), htonl(mask));
412 #endif /* BGP */
413
414 // Add/Remove the IPs to the 'sessionbyip' cache.
415 // Note that we add the zero address in the case of
416 // a network route. Roll on CIDR.
417
418 // Note that 's == 0' implies this is the address pool.
419 // We still cache it here, because it will pre-fill
420 // the malloc'ed tree.
421
422 if (s)
423 {
424 if (!add) // Are we deleting a route?
425 s = 0; // Caching the session as '0' is the same as uncaching.
426
427 for (i = ip; (i&mask) == (ip&mask) ; ++i)
428 cache_ipmap(i, s);
429 }
430 }
431
432 void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add)
433 {
434 struct in6_rtmsg rt;
435 char ipv6addr[INET6_ADDRSTRLEN];
436
437 if (ifr6fd < 0)
438 {
439 LOG(0, 0, 0, "Asked to set IPv6 route, but IPv6 not setup.\n");
440 return;
441 }
442
443 memset(&rt, 0, sizeof(rt));
444
445 memcpy(&rt.rtmsg_dst, &ip, sizeof(struct in6_addr));
446 rt.rtmsg_dst_len = prefixlen;
447 rt.rtmsg_metric = 1;
448 rt.rtmsg_flags = RTF_UP;
449 rt.rtmsg_ifindex = tunidx;
450
451 LOG(1, 0, 0, "Route %s %s/%d\n",
452 add ? "add" : "del",
453 inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN),
454 prefixlen);
455
456 if (ioctl(ifr6fd, add ? SIOCADDRT : SIOCDELRT, (void *) &rt) < 0)
457 LOG(0, 0, 0, "route6set() error in ioctl: %s\n",
458 strerror(errno));
459
460 // FIXME: need to add BGP routing (RFC2858)
461
462 if (s)
463 {
464 if (!add) // Are we deleting a route?
465 s = 0; // Caching the session as '0' is the same as uncaching.
466
467 cache_ipv6map(ip, prefixlen, s);
468 }
469
470 return;
471 }
472
473 // defined in linux/ipv6.h, but tricky to include from user-space
474 // TODO: move routing to use netlink rather than ioctl
475 struct in6_ifreq {
476 struct in6_addr ifr6_addr;
477 __u32 ifr6_prefixlen;
478 unsigned int ifr6_ifindex;
479 };
480
481 //
482 // Set up TUN interface
483 static void inittun(void)
484 {
485 struct ifreq ifr;
486 struct in6_ifreq ifr6;
487 struct sockaddr_in sin = {0};
488 memset(&ifr, 0, sizeof(ifr));
489 ifr.ifr_flags = IFF_TUN;
490
491 tunfd = open(TUNDEVICE, O_RDWR);
492 if (tunfd < 0)
493 { // fatal
494 LOG(0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
495 exit(1);
496 }
497 {
498 int flags = fcntl(tunfd, F_GETFL, 0);
499 fcntl(tunfd, F_SETFL, flags | O_NONBLOCK);
500 }
501 if (ioctl(tunfd, TUNSETIFF, (void *) &ifr) < 0)
502 {
503 LOG(0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
504 exit(1);
505 }
506 assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
507 strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
508 ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
509
510 sin.sin_family = AF_INET;
511 sin.sin_addr.s_addr = config->bind_address ? config->bind_address : 0x01010101; // 1.1.1.1
512 memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));
513
514 if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0)
515 {
516 LOG(0, 0, 0, "Error setting tun address: %s\n", strerror(errno));
517 exit(1);
518 }
519 /* Bump up the qlen to deal with bursts from the network */
520 ifr.ifr_qlen = 1000;
521 if (ioctl(ifrfd, SIOCSIFTXQLEN, (void *) &ifr) < 0)
522 {
523 LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
524 exit(1);
525 }
526 ifr.ifr_flags = IFF_UP;
527 if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
528 {
529 LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
530 exit(1);
531 }
532 if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
533 {
534 LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
535 exit(1);
536 }
537 tunidx = ifr.ifr_ifindex;
538
539 // Only setup IPv6 on the tun device if we have a configured prefix
540 if (config->ipv6_prefix.s6_addr[0] > 0) {
541 ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0);
542
543 // Link local address is FE80::1
544 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
545 ifr6.ifr6_addr.s6_addr[0] = 0xFE;
546 ifr6.ifr6_addr.s6_addr[1] = 0x80;
547 ifr6.ifr6_addr.s6_addr[15] = 1;
548 ifr6.ifr6_prefixlen = 64;
549 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
550 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
551 {
552 LOG(0, 0, 0, "Error setting tun IPv6 link local address:"
553 " %s\n", strerror(errno));
554 }
555
556 // Global address is prefix::1
557 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
558 ifr6.ifr6_addr = config->ipv6_prefix;
559 ifr6.ifr6_addr.s6_addr[15] = 1;
560 ifr6.ifr6_prefixlen = 64;
561 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
562 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
563 {
564 LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n",
565 strerror(errno));
566 }
567 }
568 }
569
570 // set up UDP port
571 static void initudp(void)
572 {
573 int on = 1;
574 struct sockaddr_in addr;
575
576 // Tunnel
577 memset(&addr, 0, sizeof(addr));
578 addr.sin_family = AF_INET;
579 addr.sin_port = htons(L2TPPORT);
580 addr.sin_addr.s_addr = config->bind_address;
581 udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
582 setsockopt(udpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
583 {
584 int flags = fcntl(udpfd, F_GETFL, 0);
585 fcntl(udpfd, F_SETFL, flags | O_NONBLOCK);
586 }
587 if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
588 {
589 LOG(0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
590 exit(1);
591 }
592 snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
593
594 // Control
595 memset(&addr, 0, sizeof(addr));
596 addr.sin_family = AF_INET;
597 addr.sin_port = htons(NSCTL_PORT);
598 controlfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
599 setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
600 if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
601 {
602 LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
603 exit(1);
604 }
605 }
606
607 //
608 // Find session by IP, < 1 for not found
609 //
610 // Confusingly enough, this 'ip' must be
611 // in _network_ order. This being the common
612 // case when looking it up from IP packet headers.
613 //
614 // We actually use this cache for two things.
615 // #1. For used IP addresses, this maps to the
616 // session ID that it's used by.
617 // #2. For un-used IP addresses, this maps to the
618 // index into the pool table that contains that
619 // IP address.
620 //
621
622 static int lookup_ipmap(in_addr_t ip)
623 {
624 uint8_t *a = (uint8_t *) &ip;
625 uint8_t **d = (uint8_t **) ip_hash;
626
627 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
628 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
629 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
630
631 return (int) (intptr_t) d[(size_t) *a];
632 }
633
634 static int lookup_ipv6map(struct in6_addr ip)
635 {
636 struct ipv6radix *curnode;
637 int i;
638 int s;
639 char ipv6addr[INET6_ADDRSTRLEN];
640
641 curnode = &ipv6_hash[ip.s6_addr[0]];
642 i = 1;
643 s = curnode->sess;
644
645 while (s == 0 && i < 15 && curnode->branch != NULL)
646 {
647 curnode = &curnode->branch[ip.s6_addr[i]];
648 s = curnode->sess;
649 i++;
650 }
651
652 LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
653 inet_ntop(AF_INET6, &ip, ipv6addr,
654 INET6_ADDRSTRLEN),
655 s);
656
657 return s;
658 }
659
660 sessionidt sessionbyip(in_addr_t ip)
661 {
662 int s = lookup_ipmap(ip);
663 CSTAT(sessionbyip);
664
665 if (s > 0 && s < MAXSESSION && session[s].opened)
666 return (sessionidt) s;
667
668 return 0;
669 }
670
671 sessionidt sessionbyipv6(struct in6_addr ip)
672 {
673 int s;
674 CSTAT(sessionbyipv6);
675
676 if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
677 (ip.s6_addr[0] == 0xFE && ip.s6_addr[1] == 0x80 &&
678 (ip.s6_addr16[1] == ip.s6_addr16[2] == ip.s6_addr16[3] == 0))) {
679 s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
680 } else {
681 s = lookup_ipv6map(ip);
682 }
683
684 if (s > 0 && s < MAXSESSION && session[s].opened)
685 return s;
686
687 return 0;
688 }
689
690 //
691 // Take an IP address in HOST byte order and
692 // add it to the sessionid by IP cache.
693 //
694 // (It's actually cached in network order)
695 //
696 static void cache_ipmap(in_addr_t ip, int s)
697 {
698 in_addr_t nip = htonl(ip); // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
699 uint8_t *a = (uint8_t *) &nip;
700 uint8_t **d = (uint8_t **) ip_hash;
701 int i;
702
703 for (i = 0; i < 3; i++)
704 {
705 if (!d[(size_t) a[i]])
706 {
707 if (!(d[(size_t) a[i]] = calloc(256, sizeof(void *))))
708 return;
709 }
710
711 d = (uint8_t **) d[(size_t) a[i]];
712 }
713
714 d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
715
716 if (s > 0)
717 LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
718
719 else if (s == 0)
720 LOG(4, 0, 0, "Un-caching ip address %s\n", fmtaddr(nip, 0));
721 // else a map to an ip pool index.
722 }
723
724 static void uncache_ipmap(in_addr_t ip)
725 {
726 cache_ipmap(ip, 0); // Assign it to the NULL session.
727 }
728
729 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
730 {
731 int i;
732 int bytes;
733 struct ipv6radix *curnode;
734 char ipv6addr[INET6_ADDRSTRLEN];
735
736 curnode = &ipv6_hash[ip.s6_addr[0]];
737
738 bytes = prefixlen >> 3;
739 i = 1;
740 while (i < bytes) {
741 if (curnode->branch == NULL)
742 {
743 if (!(curnode->branch = calloc(256,
744 sizeof (struct ipv6radix))))
745 return;
746 }
747 curnode = &curnode->branch[ip.s6_addr[i]];
748 i++;
749 }
750
751 curnode->sess = s;
752
753 if (s > 0)
754 LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
755 inet_ntop(AF_INET6, &ip, ipv6addr,
756 INET6_ADDRSTRLEN),
757 prefixlen);
758 else if (s == 0)
759 LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
760 inet_ntop(AF_INET6, &ip, ipv6addr,
761 INET6_ADDRSTRLEN),
762 prefixlen);
763 }
764
765 //
766 // CLI list to dump current ipcache.
767 //
768 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
769 {
770 char **d = (char **) ip_hash, **e, **f, **g;
771 int i, j, k, l;
772 int count = 0;
773
774 if (CLI_HELP_REQUESTED)
775 return CLI_HELP_NO_ARGS;
776
777 cli_print(cli, "%7s %s", "Sess#", "IP Address");
778
779 for (i = 0; i < 256; ++i)
780 {
781 if (!d[i])
782 continue;
783 e = (char **) d[i];
784 for (j = 0; j < 256; ++j)
785 {
786 if (!e[j])
787 continue;
788 f = (char **) e[j];
789 for (k = 0; k < 256; ++k)
790 {
791 if (!f[k])
792 continue;
793 g = (char **)f[k];
794 for (l = 0; l < 256; ++l)
795 {
796 if (!g[l])
797 continue;
798 cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
799 ++count;
800 }
801 }
802 }
803 }
804 cli_print(cli, "%d entries in cache", count);
805 return CLI_OK;
806 }
807
808
809 // Find session by username, 0 for not found
810 // walled garden users aren't authenticated, so the username is
811 // reasonably useless. Ignore them to avoid incorrect actions
812 //
813 // This is VERY inefficent. Don't call it often. :)
814 //
815 sessionidt sessionbyuser(char *username)
816 {
817 int s;
818 CSTAT(sessionbyuser);
819
820 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
821 {
822 if (!session[s].opened)
823 continue;
824
825 if (session[s].walled_garden)
826 continue; // Skip walled garden users.
827
828 if (!strncmp(session[s].user, username, 128))
829 return s;
830
831 }
832 return 0; // Not found.
833 }
834
835 void send_garp(in_addr_t ip)
836 {
837 int s;
838 struct ifreq ifr;
839 uint8_t mac[6];
840
841 s = socket(PF_INET, SOCK_DGRAM, 0);
842 if (s < 0)
843 {
844 LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
845 return;
846 }
847 memset(&ifr, 0, sizeof(ifr));
848 strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
849 if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
850 {
851 LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
852 close(s);
853 return;
854 }
855 memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
856 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
857 {
858 LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
859 close(s);
860 return;
861 }
862 close(s);
863 sendarp(ifr.ifr_ifindex, mac, ip);
864 }
865
866 static sessiont *sessiontbysessionidt(sessionidt s)
867 {
868 if (!s || s >= MAXSESSION) return NULL;
869 return &session[s];
870 }
871
872 static sessionidt sessionidtbysessiont(sessiont *s)
873 {
874 sessionidt val = s-session;
875 if (s < session || val >= MAXSESSION) return 0;
876 return val;
877 }
878
879 // actually send a control message for a specific tunnel
880 void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
881 {
882 struct sockaddr_in addr;
883
884 CSTAT(tunnelsend);
885
886 if (!t)
887 {
888 static int backtrace_count = 0;
889 LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
890 STAT(tunnel_tx_errors);
891 log_backtrace(backtrace_count, 5)
892 return;
893 }
894
895 if (!tunnel[t].ip)
896 {
897 static int backtrace_count = 0;
898 LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
899 log_backtrace(backtrace_count, 5)
900 STAT(tunnel_tx_errors);
901 return;
902 }
903
904 memset(&addr, 0, sizeof(addr));
905 addr.sin_family = AF_INET;
906 *(uint32_t *) & addr.sin_addr = htonl(tunnel[t].ip);
907 addr.sin_port = htons(tunnel[t].port);
908
909 // sequence expected, if sequence in message
910 if (*buf & 0x08) *(uint16_t *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
911
912 // If this is a control message, deal with retries
913 if (*buf & 0x80)
914 {
915 tunnel[t].last = time_now; // control message sent
916 tunnel[t].retry = backoff(tunnel[t].try); // when to resend
917 if (tunnel[t].try > 1)
918 {
919 STAT(tunnel_retries);
920 LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
921 }
922 }
923
924 if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
925 {
926 LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
927 strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
928 STAT(tunnel_tx_errors);
929 return;
930 }
931
932 LOG_HEX(5, "Send Tunnel Data", buf, l);
933 STAT(tunnel_tx_packets);
934 INC_STAT(tunnel_tx_bytes, l);
935 }
936
937 //
938 // Tiny helper function to write data to
939 // the 'tun' device.
940 //
941 int tun_write(uint8_t * data, int size)
942 {
943 return write(tunfd, data, size);
944 }
945
946 // process outgoing (to tunnel) IP
947 //
948 static void processipout(uint8_t * buf, int len)
949 {
950 sessionidt s;
951 sessiont *sp;
952 tunnelidt t;
953 in_addr_t ip;
954
955 char *data = buf; // Keep a copy of the originals.
956 int size = len;
957
958 uint8_t b[MAXETHER + 20];
959
960 CSTAT(processipout);
961
962 if (len < MIN_IP_SIZE)
963 {
964 LOG(1, 0, 0, "Short IP, %d bytes\n", len);
965 STAT(tun_rx_errors);
966 return;
967 }
968 if (len >= MAXETHER)
969 {
970 LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
971 STAT(tun_rx_errors);
972 return;
973 }
974
975 // Skip the tun header
976 buf += 4;
977 len -= 4;
978
979 // Got an IP header now
980 if (*(uint8_t *)(buf) >> 4 != 4)
981 {
982 LOG(1, 0, 0, "IP: Don't understand anything except IPv4\n");
983 return;
984 }
985
986 ip = *(uint32_t *)(buf + 16);
987 if (!(s = sessionbyip(ip)))
988 {
989 // Is this a packet for a session that doesn't exist?
990 static int rate = 0; // Number of ICMP packets we've sent this second.
991 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
992
993 if (last != time_now)
994 {
995 last = time_now;
996 rate = 0;
997 }
998
999 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1000 {
1001 LOG(4, 0, 0, "IP: Sending ICMP host unreachable to %s\n", fmtaddr(*(in_addr_t *)(buf + 12), 0));
1002 host_unreachable(*(in_addr_t *)(buf + 12), *(uint16_t *)(buf + 4), ip, buf, (len < 64) ? 64 : len);
1003 }
1004 return;
1005 }
1006 t = session[s].tunnel;
1007 sp = &session[s];
1008
1009 // DoS prevention: enforce a maximum number of packets per 0.1s for a session
1010 if (config->max_packets > 0)
1011 {
1012 if (sess_local[s].last_packet_out == TIME)
1013 {
1014 int max = config->max_packets;
1015
1016 // All packets for throttled sessions are handled by the
1017 // master, so further limit by using the throttle rate.
1018 // A bit of a kludge, since throttle rate is in kbps,
1019 // but should still be generous given our average DSL
1020 // packet size is 200 bytes: a limit of 28kbps equates
1021 // to around 180 packets per second.
1022 if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
1023 max = sp->throttle_out;
1024
1025 if (++sess_local[s].packets_out > max)
1026 {
1027 sess_local[s].packets_dropped++;
1028 return;
1029 }
1030 }
1031 else
1032 {
1033 if (sess_local[s].packets_dropped)
1034 {
1035 INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
1036 LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
1037 sess_local[s].packets_dropped, sess_local[s].packets_out,
1038 fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
1039 sp->user);
1040 }
1041
1042 sess_local[s].last_packet_out = TIME;
1043 sess_local[s].packets_out = 1;
1044 sess_local[s].packets_dropped = 0;
1045 }
1046 }
1047
1048 // run access-list if any
1049 if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
1050 return;
1051
1052 if (sp->tbf_out)
1053 {
1054 // Are we throttling this session?
1055 if (config->cluster_iam_master)
1056 tbf_queue_packet(sp->tbf_out, data, size);
1057 else
1058 master_throttle_packet(sp->tbf_out, data, size);
1059 return;
1060 }
1061 else if (sp->walled_garden && !config->cluster_iam_master)
1062 {
1063 // We are walled-gardening this
1064 master_garden_packet(s, data, size);
1065 return;
1066 }
1067
1068 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1069
1070 // Add on L2TP header
1071 {
1072 uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
1073 if (!p) return;
1074 tunnelsend(b, len + (p-b), t); // send it...
1075 }
1076
1077 // Snooping this session, send it to intercept box
1078 if (sp->snoop_ip && sp->snoop_port)
1079 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1080
1081 sp->cout += len; // byte count
1082 sp->total_cout += len; // byte count
1083 sp->pout++;
1084 udp_tx += len;
1085 sess_local[s].cout += len; // To send to master..
1086 }
1087
1088 // process outgoing (to tunnel) IPv6
1089 //
1090 static void processipv6out(uint8_t * buf, int len)
1091 {
1092 sessionidt s;
1093 sessiont *sp;
1094 tunnelidt t;
1095 in_addr_t ip;
1096 struct in6_addr ip6;
1097
1098 char *data = buf; // Keep a copy of the originals.
1099 int size = len;
1100
1101 uint8_t b[MAXETHER + 20];
1102
1103 CSTAT(processipv6out);
1104
1105 if (len < MIN_IP_SIZE)
1106 {
1107 LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
1108 STAT(tunnel_tx_errors);
1109 return;
1110 }
1111 if (len >= MAXETHER)
1112 {
1113 LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
1114 STAT(tunnel_tx_errors);
1115 return;
1116 }
1117
1118 // Skip the tun header
1119 buf += 4;
1120 len -= 4;
1121
1122 // Got an IP header now
1123 if (*(uint8_t *)(buf) >> 4 != 6)
1124 {
1125 LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
1126 return;
1127 }
1128
1129 ip6 = *(struct in6_addr *)(buf+24);
1130 s = sessionbyipv6(ip6);
1131
1132 if (s == 0)
1133 {
1134 ip = *(uint32_t *)(buf + 32);
1135 s = sessionbyip(ip);
1136 }
1137
1138 if (s == 0)
1139 {
1140 // Is this a packet for a session that doesn't exist?
1141 static int rate = 0; // Number of ICMP packets we've sent this second.
1142 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1143
1144 if (last != time_now)
1145 {
1146 last = time_now;
1147 rate = 0;
1148 }
1149
1150 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1151 {
1152 // FIXME: Should send icmp6 host unreachable
1153 }
1154 return;
1155 }
1156 t = session[s].tunnel;
1157 sp = &session[s];
1158
1159 // FIXME: add DoS prevention/filters?
1160
1161 if (sp->tbf_out)
1162 {
1163 // Are we throttling this session?
1164 if (config->cluster_iam_master)
1165 tbf_queue_packet(sp->tbf_out, data, size);
1166 else
1167 master_throttle_packet(sp->tbf_out, data, size);
1168 return;
1169 }
1170 else if (sp->walled_garden && !config->cluster_iam_master)
1171 {
1172 // We are walled-gardening this
1173 master_garden_packet(s, data, size);
1174 return;
1175 }
1176
1177 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1178
1179 // Add on L2TP header
1180 {
1181 uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIPV6);
1182 if (!p) return;
1183 tunnelsend(b, len + (p-b), t); // send it...
1184 }
1185
1186 // Snooping this session, send it to intercept box
1187 if (sp->snoop_ip && sp->snoop_port)
1188 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1189
1190 sp->cout += len; // byte count
1191 sp->total_cout += len; // byte count
1192 sp->pout++;
1193 udp_tx += len;
1194 sess_local[s].cout += len; // To send to master..
1195 }
1196
1197 //
1198 // Helper routine for the TBF filters.
1199 // Used to send queued data in to the user!
1200 //
1201 static void send_ipout(sessionidt s, uint8_t *buf, int len)
1202 {
1203 sessiont *sp;
1204 tunnelidt t;
1205 in_addr_t ip;
1206
1207 uint8_t b[MAXETHER + 20];
1208
1209 if (len < 0 || len > MAXETHER)
1210 {
1211 LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
1212 return;
1213 }
1214
1215 // Skip the tun header
1216 buf += 4;
1217 len -= 4;
1218
1219 ip = *(in_addr_t *)(buf + 16);
1220
1221 if (!session[s].ip)
1222 return;
1223
1224 t = session[s].tunnel;
1225 sp = &session[s];
1226
1227 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1228
1229 // Add on L2TP header
1230 {
1231 uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
1232 if (!p) return;
1233 tunnelsend(b, len + (p-b), t); // send it...
1234 }
1235
1236 // Snooping this session.
1237 if (sp->snoop_ip && sp->snoop_port)
1238 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1239
1240 sp->cout += len; // byte count
1241 sp->total_cout += len; // byte count
1242 sp->pout++;
1243 udp_tx += len;
1244 sess_local[s].cout += len; // To send to master..
1245 }
1246
1247 // add an AVP (16 bit)
1248 static void control16(controlt * c, uint16_t avp, uint16_t val, uint8_t m)
1249 {
1250 uint16_t l = (m ? 0x8008 : 0x0008);
1251 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1252 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1253 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1254 *(uint16_t *) (c->buf + c->length + 6) = htons(val);
1255 c->length += 8;
1256 }
1257
1258 // add an AVP (32 bit)
1259 static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
1260 {
1261 uint16_t l = (m ? 0x800A : 0x000A);
1262 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1263 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1264 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1265 *(uint32_t *) (c->buf + c->length + 6) = htonl(val);
1266 c->length += 10;
1267 }
1268
1269 // add an AVP (string)
1270 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
1271 {
1272 uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
1273 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1274 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1275 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1276 memcpy(c->buf + c->length + 6, val, strlen(val));
1277 c->length += 6 + strlen(val);
1278 }
1279
1280 // add a binary AVP
1281 static void controlb(controlt * c, uint16_t avp, char *val, unsigned int len, uint8_t m)
1282 {
1283 uint16_t l = ((m ? 0x8000 : 0) + len + 6);
1284 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1285 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1286 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1287 memcpy(c->buf + c->length + 6, val, len);
1288 c->length += 6 + len;
1289 }
1290
1291 // new control connection
1292 static controlt *controlnew(uint16_t mtype)
1293 {
1294 controlt *c;
1295 if (!controlfree)
1296 c = malloc(sizeof(controlt));
1297 else
1298 {
1299 c = controlfree;
1300 controlfree = c->next;
1301 }
1302 assert(c);
1303 c->next = 0;
1304 *(uint16_t *) (c->buf + 0) = htons(0xC802); // flags/ver
1305 c->length = 12;
1306 control16(c, 0, mtype, 1);
1307 return c;
1308 }
1309
1310 // send zero block if nothing is waiting
1311 // (ZLB send).
1312 static void controlnull(tunnelidt t)
1313 {
1314 uint8_t buf[12];
1315 if (tunnel[t].controlc) // Messages queued; They will carry the ack.
1316 return;
1317
1318 *(uint16_t *) (buf + 0) = htons(0xC802); // flags/ver
1319 *(uint16_t *) (buf + 2) = htons(12); // length
1320 *(uint16_t *) (buf + 4) = htons(tunnel[t].far); // tunnel
1321 *(uint16_t *) (buf + 6) = htons(0); // session
1322 *(uint16_t *) (buf + 8) = htons(tunnel[t].ns); // sequence
1323 *(uint16_t *) (buf + 10) = htons(tunnel[t].nr); // sequence
1324 tunnelsend(buf, 12, t);
1325 }
1326
1327 // add a control message to a tunnel, and send if within window
1328 static void controladd(controlt * c, tunnelidt t, sessionidt far)
1329 {
1330 *(uint16_t *) (c->buf + 2) = htons(c->length); // length
1331 *(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
1332 *(uint16_t *) (c->buf + 6) = htons(far); // session
1333 *(uint16_t *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
1334 tunnel[t].ns++; // advance sequence
1335 // link in message in to queue
1336 if (tunnel[t].controlc)
1337 tunnel[t].controle->next = c;
1338 else
1339 tunnel[t].controls = c;
1340
1341 tunnel[t].controle = c;
1342 tunnel[t].controlc++;
1343
1344 // send now if space in window
1345 if (tunnel[t].controlc <= tunnel[t].window)
1346 {
1347 tunnel[t].try = 0; // first send
1348 tunnelsend(c->buf, c->length, t);
1349 }
1350 }
1351
1352 //
1353 // Throttle or Unthrottle a session
1354 //
1355 // Throttle the data from/to through a session to no more than
1356 // 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
1357 // user).
1358 //
1359 // If either value is -1, the current value is retained for that
1360 // direction.
1361 //
1362 void throttle_session(sessionidt s, int rate_in, int rate_out)
1363 {
1364 if (!session[s].opened)
1365 return; // No-one home.
1366
1367 if (!*session[s].user)
1368 return; // User not logged in
1369
1370 if (rate_in >= 0)
1371 {
1372 int bytes = rate_in * 1024 / 8; // kbits to bytes
1373 if (session[s].tbf_in)
1374 free_tbf(session[s].tbf_in);
1375
1376 if (rate_in > 0)
1377 session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
1378 else
1379 session[s].tbf_in = 0;
1380
1381 session[s].throttle_in = rate_in;
1382 }
1383
1384 if (rate_out >= 0)
1385 {
1386 int bytes = rate_out * 1024 / 8;
1387 if (session[s].tbf_out)
1388 free_tbf(session[s].tbf_out);
1389
1390 if (rate_out > 0)
1391 session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
1392 else
1393 session[s].tbf_out = 0;
1394
1395 session[s].throttle_out = rate_out;
1396 }
1397 }
1398
1399 // add/remove filters from session (-1 = no change)
1400 static void filter_session(sessionidt s, int filter_in, int filter_out)
1401 {
1402 if (!session[s].opened)
1403 return; // No-one home.
1404
1405 if (!*session[s].user)
1406 return; // User not logged in
1407
1408 // paranoia
1409 if (filter_in > MAXFILTER) filter_in = -1;
1410 if (filter_out > MAXFILTER) filter_out = -1;
1411 if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
1412 if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
1413
1414 if (filter_in >= 0)
1415 {
1416 if (session[s].filter_in)
1417 ip_filters[session[s].filter_in - 1].used--;
1418
1419 if (filter_in > 0)
1420 ip_filters[filter_in - 1].used++;
1421
1422 session[s].filter_in = filter_in;
1423 }
1424
1425 if (filter_out >= 0)
1426 {
1427 if (session[s].filter_out)
1428 ip_filters[session[s].filter_out - 1].used--;
1429
1430 if (filter_out > 0)
1431 ip_filters[filter_out - 1].used++;
1432
1433 session[s].filter_out = filter_out;
1434 }
1435 }
1436
1437 // start tidy shutdown of session
1438 void sessionshutdown(sessionidt s, char *reason, int result, int error)
1439 {
1440 int walled_garden = session[s].walled_garden;
1441
1442
1443 CSTAT(sessionshutdown);
1444
1445 if (!session[s].opened)
1446 {
1447 LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
1448 return; // not a live session
1449 }
1450
1451 if (!session[s].die)
1452 {
1453 struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
1454 LOG(2, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
1455 run_plugins(PLUGIN_KILL_SESSION, &data);
1456 }
1457
1458 if (session[s].ip && !walled_garden && !session[s].die)
1459 {
1460 // RADIUS Stop message
1461 uint16_t r = sess_local[s].radius;
1462 if (!r)
1463 r = radiusnew(s);
1464
1465 if (r)
1466 {
1467 // stop, if not already trying
1468 if (radius[r].state != RADIUSSTOP)
1469 radiussend(r, RADIUSSTOP);
1470 }
1471 else
1472 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
1473
1474 // Save counters to dump to accounting file
1475 if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
1476 memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
1477 }
1478
1479 if (session[s].ip)
1480 { // IP allocated, clear and unroute
1481 int r;
1482 int routed = 0;
1483 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
1484 {
1485 if ((session[s].ip & session[s].route[r].mask) ==
1486 (session[s].route[r].ip & session[s].route[r].mask))
1487 routed++;
1488
1489 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
1490 session[s].route[r].ip = 0;
1491 }
1492
1493 if (session[s].ip_pool_index == -1) // static ip
1494 {
1495 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
1496 session[s].ip = 0;
1497 }
1498 else
1499 free_ip_address(s);
1500
1501 // unroute IPv6, if setup
1502 if (session[s].flags & SF_IPV6_ROUTED)
1503 route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
1504 }
1505
1506 if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
1507 throttle_session(s, 0, 0);
1508
1509 if (result)
1510 { // Send CDN
1511 controlt *c = controlnew(14); // sending CDN
1512 if (error)
1513 {
1514 char buf[4];
1515 *(uint16_t *) buf = htons(result);
1516 *(uint16_t *) (buf+2) = htons(error);
1517 controlb(c, 1, buf, 4, 1);
1518 }
1519 else
1520 control16(c, 1, result, 1);
1521
1522 control16(c, 14, s, 1); // assigned session (our end)
1523 controladd(c, session[s].tunnel, session[s].far); // send the message
1524 }
1525
1526 if (!session[s].die)
1527 session[s].die = TIME + 150; // Clean up in 15 seconds
1528
1529 // update filter refcounts
1530 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1531 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1532
1533 cluster_send_session(s);
1534 }
1535
1536 void sendipcp(tunnelidt t, sessionidt s)
1537 {
1538 uint8_t buf[MAXCONTROL];
1539 uint16_t r = sess_local[s].radius;
1540 uint8_t *q;
1541
1542 CSTAT(sendipcp);
1543
1544 if (!r)
1545 r = radiusnew(s);
1546
1547 if (!r)
1548 {
1549 sessionshutdown(s, "No free RADIUS sessions for IPCP", 3, 0);
1550 return;
1551 }
1552
1553 if (radius[r].state != RADIUSIPCP)
1554 {
1555 radius[r].state = RADIUSIPCP;
1556 radius[r].try = 0;
1557 }
1558
1559 radius[r].retry = backoff(radius[r].try++);
1560 if (radius[r].try > 10)
1561 {
1562 radiusclear(r, s); // Clear radius session.
1563 sessionshutdown(s, "No reply to IPCP.", 3, 0);
1564 return;
1565 }
1566
1567 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
1568 if (!q) return;
1569
1570 *q = ConfigReq;
1571 q[1] = r >> RADIUS_SHIFT; // ID, dont care, we only send one type of request
1572 *(uint16_t *) (q + 2) = htons(10);
1573 q[4] = 3;
1574 q[5] = 6;
1575 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1576 config->bind_address ? config->bind_address :
1577 my_address; // send my IP
1578
1579 tunnelsend(buf, 10 + (q - buf), t); // send it
1580 session[s].flags &= ~SF_IPCP_ACKED; // Clear flag.
1581
1582 // If we have an IPv6 prefix length configured, assume we should
1583 // try to negotiate an IPv6 session as well. Unless we've had a
1584 // (N)ACK for IPV6CP.
1585 if (config->ipv6_prefix.s6_addr[0] > 0 &&
1586 !(session[s].flags & SF_IPV6CP_ACKED) &&
1587 !(session[s].flags & SF_IPV6_NACKED))
1588 {
1589 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
1590 if (!q) return;
1591
1592 *q = ConfigReq;
1593 q[1] = r >> RADIUS_SHIFT; // ID, don't care, we
1594 // only send one type
1595 // of request
1596 *(uint16_t *) (q + 2) = htons(14);
1597 q[4] = 1;
1598 q[5] = 10;
1599 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1600 *(uint32_t *) (q + 10) = 0;
1601 q[13] = 1;
1602
1603 tunnelsend(buf, 14 + (q - buf), t); // send it
1604 }
1605 }
1606
1607 static void sessionclear(sessionidt s)
1608 {
1609 memset(&session[s], 0, sizeof(session[s]));
1610 memset(&sess_local[s], 0, sizeof(sess_local[s]));
1611 memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
1612
1613 session[s].tunnel = T_FREE; // Mark it as free.
1614 session[s].next = sessionfree;
1615 sessionfree = s;
1616 }
1617
1618 // kill a session now
1619 void sessionkill(sessionidt s, char *reason)
1620 {
1621
1622 CSTAT(sessionkill);
1623
1624 if (!session[s].opened) // not alive
1625 return;
1626
1627 if (session[s].next)
1628 {
1629 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1630 return;
1631 }
1632
1633 session[s].die = TIME;
1634 sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
1635 if (sess_local[s].radius)
1636 radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
1637
1638 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1639 sessionclear(s);
1640 cluster_send_session(s);
1641 }
1642
1643 static void tunnelclear(tunnelidt t)
1644 {
1645 if (!t) return;
1646 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1647 tunnel[t].state = TUNNELFREE;
1648 }
1649
1650 // kill a tunnel now
1651 static void tunnelkill(tunnelidt t, char *reason)
1652 {
1653 sessionidt s;
1654 controlt *c;
1655
1656 CSTAT(tunnelkill);
1657
1658 tunnel[t].state = TUNNELDIE;
1659
1660 // free control messages
1661 while ((c = tunnel[t].controls))
1662 {
1663 controlt * n = c->next;
1664 tunnel[t].controls = n;
1665 tunnel[t].controlc--;
1666 c->next = controlfree;
1667 controlfree = c;
1668 }
1669 // kill sessions
1670 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1671 if (session[s].tunnel == t)
1672 sessionkill(s, reason);
1673
1674 // free tunnel
1675 tunnelclear(t);
1676 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1677 cli_tunnel_actions[t].action = 0;
1678 cluster_send_tunnel(t);
1679 }
1680
1681 // shut down a tunnel cleanly
1682 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1683 {
1684 sessionidt s;
1685
1686 CSTAT(tunnelshutdown);
1687
1688 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1689 {
1690 // never set up, can immediately kill
1691 tunnelkill(t, reason);
1692 return;
1693 }
1694 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1695
1696 // close session
1697 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1698 if (session[s].tunnel == t)
1699 sessionshutdown(s, reason, 3, 0);
1700
1701 tunnel[t].state = TUNNELDIE;
1702 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1703 cluster_send_tunnel(t);
1704 // TBA - should we wait for sessions to stop?
1705 if (result)
1706 {
1707 controlt *c = controlnew(4); // sending StopCCN
1708 if (error)
1709 {
1710 char buf[64];
1711 int l = 4;
1712 *(uint16_t *) buf = htons(result);
1713 *(uint16_t *) (buf+2) = htons(error);
1714 if (msg)
1715 {
1716 int m = strlen(msg);
1717 if (m + 4 > sizeof(buf))
1718 m = sizeof(buf) - 4;
1719
1720 memcpy(buf+4, msg, m);
1721 l += m;
1722 }
1723
1724 controlb(c, 1, buf, l, 1);
1725 }
1726 else
1727 control16(c, 1, result, 1);
1728
1729 control16(c, 9, t, 1); // assigned tunnel (our end)
1730 controladd(c, t, 0); // send the message
1731 }
1732 }
1733
1734 // read and process packet on tunnel (UDP)
1735 void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
1736 {
1737 char *chapresponse = NULL;
1738 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1739 uint8_t *p = buf + 2;
1740
1741
1742 CSTAT(processudp);
1743
1744 udp_rx += len;
1745 udp_rx_pkt++;
1746 LOG_HEX(5, "UDP Data", buf, len);
1747 STAT(tunnel_rx_packets);
1748 INC_STAT(tunnel_rx_bytes, len);
1749 if (len < 6)
1750 {
1751 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1752 STAT(tunnel_rx_errors);
1753 return;
1754 }
1755 if ((buf[1] & 0x0F) != 2)
1756 {
1757 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1758 STAT(tunnel_rx_errors);
1759 return;
1760 }
1761 if (*buf & 0x40)
1762 { // length
1763 l = ntohs(*(uint16_t *) p);
1764 p += 2;
1765 }
1766 t = ntohs(*(uint16_t *) p);
1767 p += 2;
1768 s = ntohs(*(uint16_t *) p);
1769 p += 2;
1770 if (s >= MAXSESSION)
1771 {
1772 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1773 STAT(tunnel_rx_errors);
1774 return;
1775 }
1776 if (t >= MAXTUNNEL)
1777 {
1778 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1779 STAT(tunnel_rx_errors);
1780 return;
1781 }
1782 if (*buf & 0x08)
1783 { // ns/nr
1784 ns = ntohs(*(uint16_t *) p);
1785 p += 2;
1786 nr = ntohs(*(uint16_t *) p);
1787 p += 2;
1788 }
1789 if (*buf & 0x02)
1790 { // offset
1791 uint16_t o = ntohs(*(uint16_t *) p);
1792 p += o + 2;
1793 }
1794 if ((p - buf) > l)
1795 {
1796 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1797 STAT(tunnel_rx_errors);
1798 return;
1799 }
1800 l -= (p - buf);
1801 if (*buf & 0x80)
1802 { // control
1803 uint16_t message = 0xFFFF; // message type
1804 uint8_t fatal = 0;
1805 uint8_t mandatory = 0;
1806 uint8_t authtype = 0; // proxy auth type
1807 uint16_t asession = 0; // assigned session
1808 uint32_t amagic = 0; // magic number
1809 uint8_t aflags = 0; // flags from last LCF
1810 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1811 char called[MAXTEL] = ""; // called number
1812 char calling[MAXTEL] = ""; // calling number
1813
1814 if (!config->cluster_iam_master)
1815 {
1816 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1817 return;
1818 }
1819
1820 // control messages must have bits 0x80|0x40|0x08
1821 // (type, length and sequence) set, and bits 0x02|0x01
1822 // (offset and priority) clear
1823 if ((*buf & 0xCB) != 0xC8)
1824 {
1825 LOG(1, s, t, "Bad control header %02X\n", *buf);
1826 STAT(tunnel_rx_errors);
1827 return;
1828 }
1829
1830 // check for duplicate tunnel open message
1831 if (!t && ns == 0)
1832 {
1833 int i;
1834
1835 //
1836 // Is this a duplicate of the first packet? (SCCRQ)
1837 //
1838 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1839 {
1840 if (tunnel[i].state != TUNNELOPENING ||
1841 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1842 tunnel[i].port != ntohs(addr->sin_port) )
1843 continue;
1844 t = i;
1845 LOG(3, s, t, "Duplicate SCCRQ?\n");
1846 break;
1847 }
1848 }
1849
1850 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1851 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1852
1853 // if no tunnel specified, assign one
1854 if (!t)
1855 {
1856 if (!(t = new_tunnel()))
1857 {
1858 LOG(1, 0, 0, "No more tunnels\n");
1859 STAT(tunnel_overflow);
1860 return;
1861 }
1862 tunnelclear(t);
1863 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1864 tunnel[t].port = ntohs(addr->sin_port);
1865 tunnel[t].window = 4; // default window
1866 STAT(tunnel_created);
1867 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1868 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1869 }
1870
1871 // If the 'ns' just received is not the 'nr' we're
1872 // expecting, just send an ack and drop it.
1873 //
1874 // if 'ns' is less, then we got a retransmitted packet.
1875 // if 'ns' is greater than missed a packet. Either way
1876 // we should ignore it.
1877 if (ns != tunnel[t].nr)
1878 {
1879 // is this the sequence we were expecting?
1880 STAT(tunnel_rx_errors);
1881 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
1882 t, ns, tunnel[t].nr);
1883
1884 if (l) // Is this not a ZLB?
1885 controlnull(t);
1886 return;
1887 }
1888
1889 // This is used to time out old tunnels
1890 tunnel[t].lastrec = time_now;
1891
1892 // check sequence of this message
1893 {
1894 int skip = tunnel[t].window; // track how many in-window packets are still in queue
1895 // some to clear maybe?
1896 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
1897 {
1898 controlt *c = tunnel[t].controls;
1899 tunnel[t].controls = c->next;
1900 tunnel[t].controlc--;
1901 c->next = controlfree;
1902 controlfree = c;
1903 skip--;
1904 tunnel[t].try = 0; // we have progress
1905 }
1906
1907 // receiver advance (do here so quoted correctly in any sends below)
1908 if (l) tunnel[t].nr = (ns + 1);
1909 if (skip < 0) skip = 0;
1910 if (skip < tunnel[t].controlc)
1911 {
1912 // some control packets can now be sent that were previous stuck out of window
1913 int tosend = tunnel[t].window - skip;
1914 controlt *c = tunnel[t].controls;
1915 while (c && skip)
1916 {
1917 c = c->next;
1918 skip--;
1919 }
1920 while (c && tosend)
1921 {
1922 tunnel[t].try = 0; // first send
1923 tunnelsend(c->buf, c->length, t);
1924 c = c->next;
1925 tosend--;
1926 }
1927 }
1928 if (!tunnel[t].controlc)
1929 tunnel[t].retry = 0; // caught up
1930 }
1931 if (l)
1932 { // if not a null message
1933 int result = 0;
1934 int error = 0;
1935 char *msg = 0;
1936
1937 // process AVPs
1938 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
1939 {
1940 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
1941 uint8_t *b = p;
1942 uint8_t flags = *p;
1943 uint16_t mtype;
1944 if (n > l)
1945 {
1946 LOG(1, s, t, "Invalid length in AVP\n");
1947 STAT(tunnel_rx_errors);
1948 return;
1949 }
1950 p += n; // next
1951 l -= n;
1952 if (flags & 0x3C) // reserved bits, should be clear
1953 {
1954 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
1955 fatal = flags;
1956 result = 2; // general error
1957 error = 3; // reserved field non-zero
1958 msg = 0;
1959 continue; // next
1960 }
1961 b += 2;
1962 if (*(uint16_t *) (b))
1963 {
1964 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
1965 fatal = flags;
1966 result = 2; // general error
1967 error = 6; // generic vendor-specific error
1968 msg = "unsupported vendor-specific";
1969 continue; // next
1970 }
1971 b += 2;
1972 mtype = ntohs(*(uint16_t *) (b));
1973 b += 2;
1974 n -= 6;
1975
1976 if (flags & 0x40)
1977 {
1978 uint16_t orig_len;
1979
1980 // handle hidden AVPs
1981 if (!*config->l2tpsecret)
1982 {
1983 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
1984 fatal = flags;
1985 result = 2; // general error
1986 error = 6; // generic vendor-specific error
1987 msg = "secret not specified";
1988 continue;
1989 }
1990 if (!session[s].random_vector_length)
1991 {
1992 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
1993 fatal = flags;
1994 result = 2; // general error
1995 error = 6; // generic
1996 msg = "no random vector";
1997 continue;
1998 }
1999 if (n < 8)
2000 {
2001 LOG(2, s, t, "Short hidden AVP.\n");
2002 fatal = flags;
2003 result = 2; // general error
2004 error = 2; // length is wrong
2005 msg = 0;
2006 continue;
2007 }
2008
2009 LOG(4, s, t, "Hidden AVP\n");
2010
2011 // Unhide the AVP
2012 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
2013
2014 orig_len = ntohs(*(uint16_t *) b);
2015 if (orig_len > n + 2)
2016 {
2017 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
2018 orig_len, n);
2019
2020 fatal = flags;
2021 result = 2; // general error
2022 error = 2; // length is wrong
2023 msg = 0;
2024 continue;
2025 }
2026
2027 b += 2;
2028 n = orig_len;
2029 }
2030
2031 LOG(4, s, t, " AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
2032 switch (mtype)
2033 {
2034 case 0: // message type
2035 message = ntohs(*(uint16_t *) b);
2036 mandatory = flags & 0x80;
2037 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_message_type(message));
2038 break;
2039 case 1: // result code
2040 {
2041 uint16_t rescode = ntohs(*(uint16_t *) b);
2042 const char* resdesc = "(unknown)";
2043 if (message == 4)
2044 { /* StopCCN */
2045 resdesc = stopccn_result_code(rescode);
2046 }
2047 else if (message == 14)
2048 { /* CDN */
2049 resdesc = cdn_result_code(rescode);
2050 }
2051
2052 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2053 if (n >= 4)
2054 {
2055 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2056 LOG(4, s, t, " Error Code %d: %s\n", errcode, error_code(errcode));
2057 }
2058 if (n > 4)
2059 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2060
2061 break;
2062 }
2063 break;
2064 case 2: // protocol version
2065 {
2066 version = ntohs(*(uint16_t *) (b));
2067 LOG(4, s, t, " Protocol version = %d\n", version);
2068 if (version && version != 0x0100)
2069 { // allow 0.0 and 1.0
2070 LOG(1, s, t, " Bad protocol version %04X\n", version);
2071 fatal = flags;
2072 result = 5; // unspported protocol version
2073 error = 0x0100; // supported version
2074 msg = 0;
2075 continue; // next
2076 }
2077 }
2078 break;
2079 case 3: // framing capabilities
2080 // LOG(4, s, t, "Framing capabilities\n");
2081 break;
2082 case 4: // bearer capabilities
2083 // LOG(4, s, t, "Bearer capabilities\n");
2084 break;
2085 case 5: // tie breaker
2086 // We never open tunnels, so we don't care about tie breakers
2087 // LOG(4, s, t, "Tie breaker\n");
2088 continue;
2089 case 6: // firmware revision
2090 // LOG(4, s, t, "Firmware revision\n");
2091 break;
2092 case 7: // host name
2093 memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
2094 memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
2095 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2096 // TBA - to send to RADIUS
2097 break;
2098 case 8: // vendor name
2099 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2100 memcpy(tunnel[t].vendor, b, (n < sizeof(tunnel[t].vendor)) ? n : sizeof(tunnel[t].vendor) - 1);
2101 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2102 break;
2103 case 9: // assigned tunnel
2104 tunnel[t].far = ntohs(*(uint16_t *) (b));
2105 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2106 break;
2107 case 10: // rx window
2108 tunnel[t].window = ntohs(*(uint16_t *) (b));
2109 if (!tunnel[t].window)
2110 tunnel[t].window = 1; // window of 0 is silly
2111 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2112 break;
2113 case 11: // Challenge
2114 {
2115 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2116 build_chap_response(b, 2, n, &chapresponse);
2117 }
2118 break;
2119 case 13: // Response
2120 // Why did they send a response? We never challenge.
2121 LOG(2, s, t, " received unexpected challenge response\n");
2122 break;
2123
2124 case 14: // assigned session
2125 asession = session[s].far = ntohs(*(uint16_t *) (b));
2126 LOG(4, s, t, " assigned session = %d\n", asession);
2127 break;
2128 case 15: // call serial number
2129 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2130 break;
2131 case 18: // bearer type
2132 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2133 // TBA - for RADIUS
2134 break;
2135 case 19: // framing type
2136 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2137 // TBA
2138 break;
2139 case 21: // called number
2140 memset(called, 0, sizeof(called));
2141 memcpy(called, b, (n < sizeof(called)) ? n : sizeof(called) - 1);
2142 LOG(4, s, t, " Called <%s>\n", called);
2143 break;
2144 case 22: // calling number
2145 memset(calling, 0, sizeof(calling));
2146 memcpy(calling, b, (n < sizeof(calling)) ? n : sizeof(calling) - 1);
2147 LOG(4, s, t, " Calling <%s>\n", calling);
2148 break;
2149 case 23: // subtype
2150 break;
2151 case 24: // tx connect speed
2152 if (n == 4)
2153 {
2154 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2155 }
2156 else
2157 {
2158 // AS5300s send connect speed as a string
2159 char tmp[30];
2160 memset(tmp, 0, sizeof(tmp));
2161 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2162 session[s].tx_connect_speed = atol(tmp);
2163 }
2164 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2165 break;
2166 case 38: // rx connect speed
2167 if (n == 4)
2168 {
2169 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2170 }
2171 else
2172 {
2173 // AS5300s send connect speed as a string
2174 char tmp[30];
2175 memset(tmp, 0, sizeof(tmp));
2176 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2177 session[s].rx_connect_speed = atol(tmp);
2178 }
2179 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2180 break;
2181 case 25: // Physical Channel ID
2182 {
2183 uint32_t tmp = ntohl(*(uint32_t *) b);
2184 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2185 break;
2186 }
2187 case 29: // Proxy Authentication Type
2188 {
2189 uint16_t atype = ntohs(*(uint16_t *)b);
2190 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, auth_type(atype));
2191 if (atype == 2)
2192 authtype = AUTHCHAP;
2193 else if (atype == 3)
2194 authtype = AUTHPAP;
2195
2196 break;
2197 }
2198 case 30: // Proxy Authentication Name
2199 {
2200 char authname[64];
2201 memset(authname, 0, sizeof(authname));
2202 memcpy(authname, b, (n < sizeof(authname)) ? n : sizeof(authname) - 1);
2203 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2204 authname);
2205 break;
2206 }
2207 case 31: // Proxy Authentication Challenge
2208 {
2209 LOG(4, s, t, " Proxy Auth Challenge\n");
2210 if (sess_local[s].radius)
2211 memcpy(radius[sess_local[s].radius].auth, b, 16);
2212 break;
2213 }
2214 case 32: // Proxy Authentication ID
2215 {
2216 uint16_t authid = ntohs(*(uint16_t *)(b));
2217 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2218 if (sess_local[s].radius)
2219 radius[sess_local[s].radius].id = authid;
2220 break;
2221 }
2222 case 33: // Proxy Authentication Response
2223 LOG(4, s, t, " Proxy Auth Response\n");
2224 break;
2225 case 27: // last sent lcp
2226 { // find magic number
2227 uint8_t *p = b, *e = p + n;
2228 while (p + 1 < e && p[1] && p + p[1] <= e)
2229 {
2230 if (*p == 5 && p[1] == 6) // Magic-Number
2231 amagic = ntohl(*(uint32_t *) (p + 2));
2232 else if (*p == 3 && p[1] == 4 && *(uint16_t *) (p + 2) == htons(PPPPAP)) // Authentication-Protocol (PAP)
2233 authtype = AUTHPAP;
2234 else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol (CHAP)
2235 authtype = AUTHCHAP;
2236 else if (*p == 7) // Protocol-Field-Compression
2237 aflags |= SESSIONPFC;
2238 else if (*p == 8) // Address-and-Control-Field-Compression
2239 aflags |= SESSIONACFC;
2240 p += p[1];
2241 }
2242 }
2243 break;
2244 case 28: // last recv lcp confreq
2245 break;
2246 case 26: // Initial Received LCP CONFREQ
2247 break;
2248 case 39: // seq required - we control it as an LNS anyway...
2249 break;
2250 case 36: // Random Vector
2251 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2252 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2253 memcpy(session[s].random_vector, b, n);
2254 session[s].random_vector_length = n;
2255 break;
2256 default:
2257 {
2258 static char e[] = "unknown AVP 0xXXXX";
2259 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2260 fatal = flags;
2261 result = 2; // general error
2262 error = 8; // unknown mandatory AVP
2263 sprintf((msg = e) + 14, "%04x", mtype);
2264 continue; // next
2265 }
2266 }
2267 }
2268 // process message
2269 if (fatal & 0x80)
2270 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2271 else
2272 switch (message)
2273 {
2274 case 1: // SCCRQ - Start Control Connection Request
2275 {
2276 controlt *c = controlnew(2); // sending SCCRP
2277 control16(c, 2, version, 1); // protocol version
2278 control32(c, 3, 3, 1); // framing
2279 controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
2280 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2281 control16(c, 9, t, 1); // assigned tunnel
2282 controladd(c, t, 0); // send the resply
2283 }
2284 tunnel[t].state = TUNNELOPENING;
2285 break;
2286 case 2: // SCCRP
2287 tunnel[t].state = TUNNELOPEN;
2288 break;
2289 case 3: // SCCN
2290 tunnel[t].state = TUNNELOPEN;
2291 controlnull(t); // ack
2292 break;
2293 case 4: // StopCCN
2294 controlnull(t); // ack
2295 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2296 break;
2297 case 6: // HELLO
2298 controlnull(t); // simply ACK
2299 break;
2300 case 7: // OCRQ
2301 // TBA
2302 break;
2303 case 8: // OCRO
2304 // TBA
2305 break;
2306 case 9: // OCCN
2307 // TBA
2308 break;
2309 case 10: // ICRQ
2310 if (sessionfree)
2311 {
2312 uint16_t r;
2313
2314 s = sessionfree;
2315 sessionfree = session[s].next;
2316 memset(&session[s], 0, sizeof(session[s]));
2317
2318 if (s > config->cluster_highest_sessionid)
2319 config->cluster_highest_sessionid = s;
2320
2321 // make a RADIUS session
2322 if ((r = radiusnew(s)))
2323 {
2324 controlt *c = controlnew(11); // sending ICRP
2325 session[s].opened = time_now;
2326 session[s].tunnel = t;
2327 session[s].far = asession;
2328 session[s].last_packet = time_now;
2329 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2330 control16(c, 14, s, 1); // assigned session
2331 controladd(c, t, asession); // send the reply
2332
2333 strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
2334 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2335 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2336 STAT(session_created);
2337 break;
2338 }
2339
2340
2341 LOG(1, s, t, "No free RADIUS sessions for ICRQ\n");
2342 sessionclear(s);
2343 }
2344 else
2345 {
2346 STAT(session_overflow);
2347 LOG(1, 0, t, "No free sessions\n");
2348 }
2349
2350 {
2351 controlt *c = controlnew(14); // CDN
2352 control16(c, 1, 4, 1); // temporary lack of resources
2353 controladd(c, session[s].tunnel, asession); // send the message
2354 }
2355 return;
2356 case 11: // ICRP
2357 // TBA
2358 break;
2359 case 12: // ICCN
2360 if (amagic == 0) amagic = time_now;
2361 session[s].magic = amagic; // set magic number
2362 session[s].l2tp_flags = aflags; // set flags received
2363 LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
2364 controlnull(t); // ack
2365 // proxy authentication type is not supported
2366 if (!(config->radius_authtypes & authtype))
2367 authtype = config->radius_authprefer;
2368
2369 // start LCP
2370 sendlcp(t, s, authtype);
2371 break;
2372 case 14: // CDN
2373 controlnull(t); // ack
2374 sessionshutdown(s, "Closed (Received CDN).", 0, 0);
2375 break;
2376 case 0xFFFF:
2377 LOG(1, s, t, "Missing message type\n");
2378 break;
2379 default:
2380 STAT(tunnel_rx_errors);
2381 if (mandatory)
2382 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2383 else
2384 LOG(1, s, t, "Unknown message type %d\n", message);
2385 break;
2386 }
2387 if (chapresponse) free(chapresponse);
2388 cluster_send_tunnel(t);
2389 }
2390 else
2391 {
2392 LOG(4, s, t, " Got a ZLB ack\n");
2393 }
2394 }
2395 else
2396 { // data
2397 uint16_t prot;
2398
2399 LOG_HEX(5, "Receive Tunnel Data", p, l);
2400 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2401 { // HDLC address header, discard
2402 p += 2;
2403 l -= 2;
2404 }
2405 if (l < 2)
2406 {
2407 LOG(1, s, t, "Short ppp length %d\n", l);
2408 STAT(tunnel_rx_errors);
2409 return;
2410 }
2411 if (*p & 1)
2412 {
2413 prot = *p++;
2414 l--;
2415 }
2416 else
2417 {
2418 prot = ntohs(*(uint16_t *) p);
2419 p += 2;
2420 l -= 2;
2421 }
2422
2423 if (s && !session[s].opened) // Is something wrong??
2424 {
2425 if (!config->cluster_iam_master)
2426 {
2427 // Pass it off to the master to deal with..
2428 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2429 return;
2430 }
2431
2432
2433 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2434 STAT(tunnel_rx_errors);
2435 return;
2436 }
2437
2438 if (prot == PPPPAP)
2439 {
2440 session[s].last_packet = time_now;
2441 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2442 processpap(t, s, p, l);
2443 }
2444 else if (prot == PPPCHAP)
2445 {
2446 session[s].last_packet = time_now;
2447 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2448 processchap(t, s, p, l);
2449 }
2450 else if (prot == PPPLCP)
2451 {
2452 session[s].last_packet = time_now;
2453 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2454 processlcp(t, s, p, l);
2455 }
2456 else if (prot == PPPIPCP)
2457 {
2458 session[s].last_packet = time_now;
2459 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2460 processipcp(t, s, p, l);
2461 }
2462 else if (prot == PPPIPV6CP)
2463 {
2464 if (config->ipv6_prefix.s6_addr[0] > 0)
2465 {
2466 session[s].last_packet = time_now;
2467 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2468 processipv6cp(t, s, p, l);
2469 }
2470 else
2471 {
2472 LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n");
2473 }
2474 }
2475 else if (prot == PPPCCP)
2476 {
2477 session[s].last_packet = time_now;
2478 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2479 processccp(t, s, p, l);
2480 }
2481 else if (prot == PPPIP)
2482 {
2483 if (session[s].die)
2484 {
2485 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2486 return; // closing session, PPP not processed
2487 }
2488
2489 session[s].last_packet = time_now;
2490 if (session[s].walled_garden && !config->cluster_iam_master)
2491 {
2492 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2493 return;
2494 }
2495
2496 processipin(t, s, p, l);
2497 }
2498 else if (prot == PPPIPV6)
2499 {
2500 if (!config->ipv6_prefix.s6_addr[0] > 0)
2501 {
2502 LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
2503 return;
2504 }
2505 if (session[s].die)
2506 {
2507 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2508 return; // closing session, PPP not processed
2509 }
2510
2511 session[s].last_packet = time_now;
2512 if (session[s].walled_garden && !config->cluster_iam_master)
2513 {
2514 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2515 return;
2516 }
2517
2518 processipv6in(t, s, p, l);
2519 }
2520 else
2521 {
2522 STAT(tunnel_rx_errors);
2523 LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
2524 }
2525 }
2526 }
2527
2528 // read and process packet on tun
2529 static void processtun(uint8_t * buf, int len)
2530 {
2531 LOG_HEX(5, "Receive TUN Data", buf, len);
2532 STAT(tun_rx_packets);
2533 INC_STAT(tun_rx_bytes, len);
2534
2535 CSTAT(processtun);
2536
2537 eth_rx_pkt++;
2538 eth_rx += len;
2539 if (len < 22)
2540 {
2541 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2542 STAT(tun_rx_errors);
2543 return;
2544 }
2545
2546 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2547 processipout(buf, len);
2548 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2549 && config->ipv6_prefix.s6_addr[0] > 0)
2550 processipv6out(buf, len);
2551
2552 // Else discard.
2553 }
2554
2555 //
2556 // Maximum number of actions to complete.
2557 // This is to avoid sending out too many packets
2558 // at once.
2559 #define MAX_ACTIONS 500
2560
2561 static int regular_cleanups(void)
2562 {
2563 static sessionidt s = 0; // Next session to check for actions on.
2564 tunnelidt t;
2565 int count=0,i;
2566 uint16_t r;
2567 static clockt next_acct = 0;
2568 static clockt next_shut_acct = 0;
2569 int a;
2570
2571 LOG(3, 0, 0, "Begin regular cleanup\n");
2572
2573 for (r = 1; r < MAXRADIUS; r++)
2574 {
2575 if (!radius[r].state)
2576 continue;
2577 if (radius[r].retry)
2578 {
2579 if (radius[r].retry <= TIME)
2580 radiusretry(r);
2581 } else
2582 radius[r].retry = backoff(radius[r].try+1); // Is this really needed? --mo
2583 }
2584 for (t = 1; t <= config->cluster_highest_tunnelid; t++)
2585 {
2586 // check for expired tunnels
2587 if (tunnel[t].die && tunnel[t].die <= TIME)
2588 {
2589 STAT(tunnel_timeout);
2590 tunnelkill(t, "Expired");
2591 continue;
2592 }
2593 // check for message resend
2594 if (tunnel[t].retry && tunnel[t].controlc)
2595 {
2596 // resend pending messages as timeout on reply
2597 if (tunnel[t].retry <= TIME)
2598 {
2599 controlt *c = tunnel[t].controls;
2600 uint8_t w = tunnel[t].window;
2601 tunnel[t].try++; // another try
2602 if (tunnel[t].try > 5)
2603 tunnelkill(t, "Timeout on control message"); // game over
2604 else
2605 while (c && w--)
2606 {
2607 tunnelsend(c->buf, c->length, t);
2608 c = c->next;
2609 }
2610 }
2611 }
2612 // Send hello
2613 if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < TIME + 600)
2614 {
2615 controlt *c = controlnew(6); // sending HELLO
2616 controladd(c, t, 0); // send the message
2617 LOG(3, 0, t, "Sending HELLO message\n");
2618 }
2619
2620 // Check for tunnel changes requested from the CLI
2621 if ((a = cli_tunnel_actions[t].action))
2622 {
2623 cli_tunnel_actions[t].action = 0;
2624 if (a & CLI_TUN_KILL)
2625 {
2626 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2627 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2628 }
2629 }
2630
2631 }
2632
2633 count = 0;
2634 for (i = 1; i <= config->cluster_highest_sessionid; i++)
2635 {
2636 s++;
2637 if (s > config->cluster_highest_sessionid)
2638 s = 1;
2639
2640 if (!session[s].opened) // Session isn't in use
2641 continue;
2642
2643 // check for expired sessions
2644 if (session[s].die)
2645 {
2646 if (session[s].die <= TIME)
2647 {
2648 sessionkill(s, "Expired");
2649 if (++count >= MAX_ACTIONS) break;
2650 }
2651 continue;
2652 }
2653
2654 if (session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
2655 {
2656 // IPCP has not completed yet. Resend
2657 LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
2658 sendipcp(session[s].tunnel, s);
2659 }
2660
2661 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2662 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2663 {
2664 sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
2665 STAT(session_timeout);
2666 if (++count >= MAX_ACTIONS) break;
2667 continue;
2668 }
2669
2670 // No data in ECHO_TIMEOUT seconds, send LCP ECHO
2671 if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
2672 {
2673 uint8_t b[MAXCONTROL] = {0};
2674
2675 uint8_t *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
2676 if (!q) continue;
2677
2678 *q = EchoReq;
2679 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2680 *(uint16_t *)(q + 2) = htons(8); // Length
2681 *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
2682
2683 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2684 (int)(time_now - session[s].last_packet));
2685 tunnelsend(b, 24, session[s].tunnel); // send it
2686 if (++count >= MAX_ACTIONS) break;
2687 }
2688
2689 // Check for actions requested from the CLI
2690 if ((a = cli_session_actions[s].action))
2691 {
2692 int send = 0;
2693
2694 cli_session_actions[s].action = 0;
2695 if (a & CLI_SESS_KILL)
2696 {
2697 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2698 sessionshutdown(s, "Requested by administrator.", 3, 0);
2699 a = 0; // dead, no need to check for other actions
2700 }
2701
2702 if (a & CLI_SESS_NOSNOOP)
2703 {
2704 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2705 session[s].snoop_ip = 0;
2706 session[s].snoop_port = 0;
2707 send++;
2708 }
2709 else if (a & CLI_SESS_SNOOP)
2710 {
2711 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2712 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2713 cli_session_actions[s].snoop_port);
2714
2715 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2716 session[s].snoop_port = cli_session_actions[s].snoop_port;
2717 send++;
2718 }
2719
2720 if (a & CLI_SESS_NOTHROTTLE)
2721 {
2722 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2723 throttle_session(s, 0, 0);
2724 send++;
2725 }
2726 else if (a & CLI_SESS_THROTTLE)
2727 {
2728 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2729 cli_session_actions[s].throttle_in,
2730 cli_session_actions[s].throttle_out);
2731
2732 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
2733 send++;
2734 }
2735
2736 if (a & CLI_SESS_NOFILTER)
2737 {
2738 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
2739 filter_session(s, 0, 0);
2740 send++;
2741 }
2742 else if (a & CLI_SESS_FILTER)
2743 {
2744 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
2745 cli_session_actions[s].filter_in,
2746 cli_session_actions[s].filter_out);
2747
2748 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
2749 send++;
2750 }
2751
2752 if (send)
2753 cluster_send_session(s);
2754
2755 if (++count >= MAX_ACTIONS) break;
2756 }
2757
2758 // RADIUS interim accounting
2759 if (config->radius_accounting && config->radius_interim > 0
2760 && session[s].ip && !session[s].walled_garden
2761 && !sess_local[s].radius // RADIUS already in progress
2762 && time_now - sess_local[s].last_interim >= config->radius_interim)
2763 {
2764 if (!(r = radiusnew(s)))
2765 {
2766 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
2767 STAT(radius_overflow);
2768 continue;
2769 }
2770
2771 LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
2772 session[s].user, session[s].unique_id);
2773
2774 radiussend(r, RADIUSINTERIM);
2775 sess_local[s].last_interim = time_now;
2776
2777 if (++count >= MAX_ACTIONS)
2778 break;
2779 }
2780 }
2781
2782 if (*config->accounting_dir)
2783 {
2784 if (next_acct <= TIME)
2785 {
2786 // Dump accounting data
2787 next_acct = TIME + ACCT_TIME;
2788 next_shut_acct = TIME + ACCT_SHUT_TIME;
2789 dump_acct_info(1);
2790 }
2791 else if (next_shut_acct <= TIME)
2792 {
2793 // Dump accounting data for shutdown sessions
2794 next_shut_acct = TIME + ACCT_SHUT_TIME;
2795 if (shut_acct_n)
2796 dump_acct_info(0);
2797 }
2798 }
2799
2800 if (count >= MAX_ACTIONS)
2801 return 1; // Didn't finish!
2802
2803 LOG(3, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
2804 return 0;
2805 }
2806
2807
2808 //
2809 // Are we in the middle of a tunnel update, or radius
2810 // requests??
2811 //
2812 static int still_busy(void)
2813 {
2814 int i;
2815 static clockt last_talked = 0;
2816 static clockt start_busy_wait = 0;
2817 if (start_busy_wait == 0)
2818 start_busy_wait = TIME;
2819
2820 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
2821 {
2822 if (!tunnel[i].controlc)
2823 continue;
2824
2825 if (last_talked != TIME)
2826 {
2827 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
2828 last_talked = TIME;
2829 }
2830 return 1;
2831 }
2832
2833 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
2834 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
2835 {
2836 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
2837 return 0;
2838 }
2839
2840 for (i = 1; i < MAXRADIUS; i++)
2841 {
2842 if (radius[i].state == RADIUSNULL)
2843 continue;
2844 if (radius[i].state == RADIUSWAIT)
2845 continue;
2846
2847 if (last_talked != TIME)
2848 {
2849 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
2850 last_talked = TIME;
2851 }
2852 return 1;
2853 }
2854
2855 return 0;
2856 }
2857
2858 static fd_set readset;
2859 static int readset_n = 0;
2860
2861 // main loop - gets packets on tun or udp and processes them
2862 static void mainloop(void)
2863 {
2864 int i;
2865 uint8_t buf[65536];
2866 struct timeval to;
2867 clockt next_cluster_ping = 0; // send initial ping immediately
2868 time_t next_clean = time_now + config->cleanup_interval;
2869
2870 LOG(4, 0, 0, "Beginning of main loop. udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
2871 udpfd, tunfd, cluster_sockfd, controlfd);
2872
2873 FD_ZERO(&readset);
2874 FD_SET(udpfd, &readset);
2875 FD_SET(tunfd, &readset);
2876 FD_SET(controlfd, &readset);
2877 FD_SET(clifd, &readset);
2878 if (cluster_sockfd) FD_SET(cluster_sockfd, &readset);
2879 readset_n = udpfd;
2880 if (tunfd > readset_n) readset_n = tunfd;
2881 if (controlfd > readset_n) readset_n = controlfd;
2882 if (clifd > readset_n) readset_n = clifd;
2883 if (cluster_sockfd > readset_n) readset_n = cluster_sockfd;
2884
2885 while (!main_quit || still_busy())
2886 {
2887 fd_set r;
2888 int n = readset_n;
2889 #ifdef BGP
2890 fd_set w;
2891 int bgp_set[BGP_NUM_PEERS];
2892 #endif /* BGP */
2893
2894 if (config->reload_config)
2895 {
2896 // Update the config state based on config settings
2897 update_config();
2898 }
2899
2900 memcpy(&r, &readset, sizeof(fd_set));
2901 to.tv_sec = 0;
2902 to.tv_usec = 100000; // 1/10th of a second.
2903
2904 #ifdef BGP
2905 FD_ZERO(&w);
2906 for (i = 0; i < BGP_NUM_PEERS; i++)
2907 {
2908 bgp_set[i] = bgp_select_state(&bgp_peers[i]);
2909 if (bgp_set[i] & 1)
2910 {
2911 FD_SET(bgp_peers[i].sock, &r);
2912 if (bgp_peers[i].sock > n)
2913 n = bgp_peers[i].sock;
2914 }
2915
2916 if (bgp_set[i] & 2)
2917 {
2918 FD_SET(bgp_peers[i].sock, &w);
2919 if (bgp_peers[i].sock > n)
2920 n = bgp_peers[i].sock;
2921 }
2922 }
2923
2924 n = select(n + 1, &r, &w, 0, &to);
2925 #else /* BGP */
2926 n = select(n + 1, &r, 0, 0, &to);
2927 #endif /* BGP */
2928
2929 STAT(select_called);
2930
2931 TIME = now();
2932 if (n < 0)
2933 {
2934 if (errno == EINTR ||
2935 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
2936 continue;
2937
2938 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
2939 main_quit++;
2940 break;
2941 }
2942 else if (n)
2943 {
2944 struct sockaddr_in addr;
2945 int alen, c, s;
2946 int udp_pkts = 0;
2947 int tun_pkts = 0;
2948 int cluster_pkts = 0;
2949
2950 // nsctl commands
2951 if (FD_ISSET(controlfd, &r))
2952 {
2953 alen = sizeof(addr);
2954 processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
2955 n--;
2956 }
2957
2958 // RADIUS responses
2959 if (config->cluster_iam_master)
2960 {
2961 for (i = 0; i < config->num_radfds; i++)
2962 {
2963 if (FD_ISSET(radfds[i], &r))
2964 {
2965 processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
2966 n--;
2967 }
2968 }
2969 }
2970
2971 // CLI connections
2972 if (FD_ISSET(clifd, &r))
2973 {
2974 int cli;
2975
2976 alen = sizeof(addr);
2977 if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
2978 {
2979 cli_do(cli);
2980 close(cli);
2981 }
2982 else
2983 LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
2984
2985 n--;
2986 }
2987
2988 #ifdef BGP
2989 for (i = 0; i < BGP_NUM_PEERS; i++)
2990 {
2991 int isr = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0;
2992 int isw = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0;
2993 bgp_process(&bgp_peers[i], isr, isw);
2994 if (isr) n--;
2995 if (isw) n--;
2996 }
2997 #endif /* BGP */
2998
2999 for (c = 0; n && c < config->multi_read_count; c++)
3000 {
3001 // L2TP
3002 if (FD_ISSET(udpfd, &r))
3003 {
3004 alen = sizeof(addr);
3005 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
3006 {
3007 processudp(buf, s, &addr);
3008 udp_pkts++;
3009 }
3010 else
3011 {
3012 FD_CLR(udpfd, &r);
3013 n--;
3014 }
3015 }
3016
3017 // incoming IP
3018 if (FD_ISSET(tunfd, &r))
3019 {
3020 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
3021 {
3022 processtun(buf, s);
3023 tun_pkts++;
3024 }
3025 else
3026 {
3027 FD_CLR(tunfd, &r);
3028 n--;
3029 }
3030 }
3031
3032 // cluster
3033 if (FD_ISSET(cluster_sockfd, &r))
3034 {
3035 alen = sizeof(addr);
3036 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
3037 {
3038 processcluster(buf, s, addr.sin_addr.s_addr);
3039 cluster_pkts++;
3040 }
3041 else
3042 {
3043 FD_CLR(cluster_sockfd, &r);
3044 n--;
3045 }
3046 }
3047 }
3048
3049 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
3050 STAT(multi_read_used);
3051
3052 if (c >= config->multi_read_count)
3053 {
3054 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
3055 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3056
3057 STAT(multi_read_exceeded);
3058 }
3059 }
3060
3061 // Runs on every machine (master and slaves).
3062 if (cluster_sockfd && next_cluster_ping <= TIME)
3063 {
3064 // Check to see which of the cluster is still alive..
3065
3066 cluster_send_ping(basetime); // Only does anything if we're a slave
3067 cluster_check_master(); // ditto.
3068
3069 cluster_heartbeat(); // Only does anything if we're a master.
3070 cluster_check_slaves(); // ditto.
3071
3072 master_update_counts(); // If we're a slave, send our byte counters to our master.
3073
3074 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3075 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3076 else
3077 next_cluster_ping = TIME + config->cluster_hb_interval;
3078 }
3079
3080 // Run token bucket filtering queue..
3081 // Only run it every 1/10th of a second.
3082 // Runs on all machines both master and slave.
3083 {
3084 static clockt last_run = 0;
3085 if (last_run != TIME)
3086 {
3087 last_run = TIME;
3088 tbf_run_timer();
3089 }
3090 }
3091
3092 /* Handle timeouts. Make sure that this gets run anyway, even if there was
3093 * something to read, else under load this will never actually run....
3094 *
3095 */
3096 if (config->cluster_iam_master && next_clean <= time_now)
3097 {
3098 if (regular_cleanups())
3099 {
3100 // Did it finish?
3101 next_clean = time_now + 1 ; // Didn't finish. Check quickly.
3102 }
3103 else
3104 {
3105 next_clean = time_now + config->cleanup_interval; // Did. Move to next interval.
3106 }
3107 }
3108 }
3109
3110 // Are we the master and shutting down??
3111 if (config->cluster_iam_master)
3112 cluster_heartbeat(); // Flush any queued changes..
3113
3114 // Ok. Notify everyone we're shutting down. If we're
3115 // the master, this will force an election.
3116 cluster_send_ping(0);
3117
3118 //
3119 // Important!!! We MUST not process any packets past this point!
3120 }
3121
3122 static void stripdomain(char *host)
3123 {
3124 char *p;
3125
3126 if ((p = strchr(host, '.')))
3127 {
3128 char *domain = 0;
3129 char _domain[1024];
3130
3131 // strip off domain
3132 FILE *resolv = fopen("/etc/resolv.conf", "r");
3133 if (resolv)
3134 {
3135 char buf[1024];
3136 char *b;
3137
3138 while (fgets(buf, sizeof(buf), resolv))
3139 {
3140 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3141 continue;
3142
3143 if (!isspace(buf[6]))
3144 continue;
3145
3146 b = buf + 7;
3147 while (isspace(*b)) b++;
3148
3149 if (*b)
3150 {
3151 char *d = b;
3152 while (*b && !isspace(*b)) b++;
3153 *b = 0;
3154 if (buf[0] == 'd') // domain is canonical
3155 {
3156 domain = d;
3157 break;
3158 }
3159
3160 // first search line
3161 if (!domain)
3162 {
3163 // hold, may be subsequent domain line
3164 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3165 domain = _domain;
3166 }
3167 }
3168 }
3169
3170 fclose(resolv);
3171 }
3172
3173 if (domain)
3174 {
3175 int hl = strlen(host);
3176 int dl = strlen(domain);
3177 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3178 host[hl -dl - 1] = 0;
3179 }
3180 else
3181 {
3182 *p = 0; // everything after first dot
3183 }
3184 }
3185 }
3186
3187 // Init data structures
3188 static void initdata(int optdebug, char *optconfig)
3189 {
3190 int i;
3191
3192 if (!(config = shared_malloc(sizeof(configt))))
3193 {
3194 fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
3195 exit(1);
3196 }
3197
3198 memset(config, 0, sizeof(configt));
3199 time(&config->start_time);
3200 strncpy(config->config_file, optconfig, strlen(optconfig));
3201 config->debug = optdebug;
3202 config->num_tbfs = MAXTBFS;
3203 config->rl_rate = 28; // 28kbps
3204 config->cluster_master_min_adv = 1;
3205 strcpy(config->random_device, RANDOMDEVICE);
3206
3207 log_stream = stderr;
3208
3209 #ifdef RINGBUFFER
3210 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3211 {
3212 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3213 exit(1);
3214 }
3215 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3216 #endif
3217
3218 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3219 {
3220 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3221 exit(1);
3222 }
3223 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3224 {
3225 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3226 exit(1);
3227 }
3228 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3229 {
3230 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3231 exit(1);
3232 }
3233
3234 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3235 {
3236 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3237 exit(1);
3238 }
3239
3240 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3241 {
3242 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3243 exit(1);
3244 }
3245
3246 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3247 {
3248 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3249 exit(1);
3250 }
3251
3252 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3253 {
3254 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3255 exit(1);
3256 }
3257 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3258
3259 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3260 {
3261 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3262 exit(1);
3263 }
3264 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3265
3266 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3267 {
3268 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3269 exit(1);
3270 }
3271 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3272
3273 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3274 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3275 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3276 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3277
3278 // Put all the sessions on the free list marked as undefined.
3279 for (i = 1; i < MAXSESSION; i++)
3280 {
3281 session[i].next = i + 1;
3282 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3283 }
3284 session[MAXSESSION - 1].next = 0;
3285 sessionfree = 1;
3286
3287 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3288 for (i = 1; i < MAXTUNNEL; i++)
3289 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3290
3291 if (!*hostname)
3292 {
3293 // Grab my hostname unless it's been specified
3294 gethostname(hostname, sizeof(hostname));
3295 stripdomain(hostname);
3296 }
3297
3298 _statistics->start_time = _statistics->last_reset = time(NULL);
3299
3300 #ifdef BGP
3301 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3302 {
3303 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3304 exit(1);
3305 }
3306 #endif /* BGP */
3307 }
3308
3309 static int assign_ip_address(sessionidt s)
3310 {
3311 uint32_t i;
3312 int best = -1;
3313 time_t best_time = time_now;
3314 char *u = session[s].user;
3315 char reuse = 0;
3316
3317
3318 CSTAT(assign_ip_address);
3319
3320 for (i = 1; i < ip_pool_size; i++)
3321 {
3322 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3323 continue;
3324
3325 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3326 {
3327 best = i;
3328 reuse = 1;
3329 break;
3330 }
3331
3332 if (ip_address_pool[i].last < best_time)
3333 {
3334 best = i;
3335 if (!(best_time = ip_address_pool[i].last))
3336 break; // never used, grab this one
3337 }
3338 }
3339
3340 if (best < 0)
3341 {
3342 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3343 return 0;
3344 }
3345
3346 session[s].ip = ip_address_pool[best].address;
3347 session[s].ip_pool_index = best;
3348 ip_address_pool[best].assigned = 1;
3349 ip_address_pool[best].last = time_now;
3350 ip_address_pool[best].session = s;
3351 if (session[s].walled_garden)
3352 /* Don't track addresses of users in walled garden (note: this
3353 means that their address isn't "sticky" even if they get
3354 un-gardened). */
3355 ip_address_pool[best].user[0] = 0;
3356 else
3357 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3358
3359 STAT(ip_allocated);
3360 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3361 reuse ? "Reusing" : "Allocating", best);
3362
3363 return 1;
3364 }
3365
3366 static void free_ip_address(sessionidt s)
3367 {
3368 int i = session[s].ip_pool_index;
3369
3370
3371 CSTAT(free_ip_address);
3372
3373 if (!session[s].ip)
3374 return; // what the?
3375
3376 if (i < 0) // Is this actually part of the ip pool?
3377 i = 0;
3378
3379 STAT(ip_freed);
3380 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3381 session[s].ip = 0;
3382 ip_address_pool[i].assigned = 0;
3383 ip_address_pool[i].session = 0;
3384 ip_address_pool[i].last = time_now;
3385 }
3386
3387 //
3388 // Fsck the address pool against the session table.
3389 // Normally only called when we become a master.
3390 //
3391 // This isn't perfect: We aren't keep tracking of which
3392 // users used to have an IP address.
3393 //
3394 void rebuild_address_pool(void)
3395 {
3396 int i;
3397
3398 //
3399 // Zero the IP pool allocation, and build
3400 // a map from IP address to pool index.
3401 for (i = 1; i < MAXIPPOOL; ++i)
3402 {
3403 ip_address_pool[i].assigned = 0;
3404 ip_address_pool[i].session = 0;
3405 if (!ip_address_pool[i].address)
3406 continue;
3407
3408 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3409 }
3410
3411 for (i = 0; i < MAXSESSION; ++i)
3412 {
3413 int ipid;
3414 if (!(session[i].opened && session[i].ip))
3415 continue;
3416
3417 ipid = - lookup_ipmap(htonl(session[i].ip));
3418
3419 if (session[i].ip_pool_index < 0)
3420 {
3421 // Not allocated out of the pool.
3422 if (ipid < 1) // Not found in the pool either? good.
3423 continue;
3424
3425 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3426 i, fmtaddr(session[i].ip, 0), ipid);
3427
3428 // Fall through and process it as part of the pool.
3429 }
3430
3431
3432 if (ipid > MAXIPPOOL || ipid < 0)
3433 {
3434 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3435 ipid = -1;
3436 session[i].ip_pool_index = ipid;
3437 continue;
3438 }
3439
3440 ip_address_pool[ipid].assigned = 1;
3441 ip_address_pool[ipid].session = i;
3442 ip_address_pool[ipid].last = time_now;
3443 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3444 session[i].ip_pool_index = ipid;
3445 cache_ipmap(session[i].ip, i); // Fix the ip map.
3446 }
3447 }
3448
3449 //
3450 // Fix the address pool to match a changed session.
3451 // (usually when the master sends us an update).
3452 static void fix_address_pool(int sid)
3453 {
3454 int ipid;
3455
3456 ipid = session[sid].ip_pool_index;
3457
3458 if (ipid > ip_pool_size)
3459 return; // Ignore it. rebuild_address_pool will fix it up.
3460
3461 if (ip_address_pool[ipid].address != session[sid].ip)
3462 return; // Just ignore it. rebuild_address_pool will take care of it.
3463
3464 ip_address_pool[ipid].assigned = 1;
3465 ip_address_pool[ipid].session = sid;
3466 ip_address_pool[ipid].last = time_now;
3467 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3468 }
3469
3470 //
3471 // Add a block of addresses to the IP pool to hand out.
3472 //
3473 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3474 {
3475 int i;
3476 if (mask == 0)
3477 mask = 0xffffffff; // Host route only.
3478
3479 addr &= mask;
3480
3481 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3482 return ;
3483
3484 for (i = addr ;(i & mask) == addr; ++i)
3485 {
3486 if ((i & 0xff) == 0 || (i&0xff) == 255)
3487 continue; // Skip 0 and broadcast addresses.
3488
3489 ip_address_pool[ip_pool_size].address = i;
3490 ip_address_pool[ip_pool_size].assigned = 0;
3491 ++ip_pool_size;
3492 if (ip_pool_size >= MAXIPPOOL)
3493 {
3494 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3495 return;
3496 }
3497 }
3498 }
3499
3500 // Initialize the IP address pool
3501 static void initippool()
3502 {
3503 FILE *f;
3504 char *p;
3505 char buf[4096];
3506 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3507
3508 if (!(f = fopen(IPPOOLFILE, "r")))
3509 {
3510 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3511 exit(1);
3512 }
3513
3514 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3515 {
3516 char *pool = buf;
3517 buf[4095] = 0; // Force it to be zero terminated/
3518
3519 if (*buf == '#' || *buf == '\n')
3520 continue; // Skip comments / blank lines
3521 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3522 if ((p = (char *)strchr(buf, ':')))
3523 {
3524 in_addr_t src;
3525 *p = '\0';
3526 src = inet_addr(buf);
3527 if (src == INADDR_NONE)
3528 {
3529 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3530 exit(1);
3531 }
3532 // This entry is for a specific IP only
3533 if (src != config->bind_address)
3534 continue;
3535 *p = ':';
3536 pool = p+1;
3537 }
3538 if ((p = (char *)strchr(pool, '/')))
3539 {
3540 // It's a range
3541 int numbits = 0;
3542 in_addr_t start = 0, mask = 0;
3543
3544 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3545 *p++ = 0;
3546 if (!*p || !(numbits = atoi(p)))
3547 {
3548 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3549 continue;
3550 }
3551 start = ntohl(inet_addr(pool));
3552 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3553
3554 // Add a static route for this pool
3555 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3556 fmtaddr(htonl(start), 0), 32 + mask);
3557
3558 routeset(0, start, mask, 0, 1);
3559
3560 add_to_ip_pool(start, mask);
3561 }
3562 else
3563 {
3564 // It's a single ip address
3565 add_to_ip_pool(inet_addr(pool), 0);
3566 }
3567 }
3568 fclose(f);
3569 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3570 }
3571
3572 void snoop_send_packet(char *packet, uint16_t size, in_addr_t destination, uint16_t port)
3573 {
3574 struct sockaddr_in snoop_addr = {0};
3575 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3576 return;
3577
3578 snoop_addr.sin_family = AF_INET;
3579 snoop_addr.sin_addr.s_addr = destination;
3580 snoop_addr.sin_port = ntohs(port);
3581
3582 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3583 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3584 htons(snoop_addr.sin_port));
3585
3586 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3587 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
3588
3589 STAT(packets_snooped);
3590 }
3591
3592 static int dump_session(FILE **f, sessiont *s)
3593 {
3594 if (!s->opened || !s->ip || !(s->cin || s->cout) || !*s->user || s->walled_garden)
3595 return 1;
3596
3597 if (!*f)
3598 {
3599 char filename[1024];
3600 char timestr[64];
3601 time_t now = time(NULL);
3602
3603 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
3604 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
3605
3606 if (!(*f = fopen(filename, "w")))
3607 {
3608 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
3609 return 0;
3610 }
3611
3612 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
3613 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
3614 "# host: %s\n"
3615 "# time: %ld\n"
3616 "# uptime: %ld\n"
3617 "# format: username ip qos uptxoctets downrxoctets\n",
3618 hostname,
3619 now,
3620 now - basetime);
3621 }
3622
3623 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
3624 fprintf(*f, "%s %s %d %u %u\n",
3625 s->user, // username
3626 fmtaddr(htonl(s->ip), 0), // ip
3627 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
3628 (uint32_t) s->cin, // uptxoctets
3629 (uint32_t) s->cout); // downrxoctets
3630
3631 s->pin = s->cin = 0;
3632 s->pout = s->cout = 0;
3633
3634 return 1;
3635 }
3636
3637 static void dump_acct_info(int all)
3638 {
3639 int i;
3640 FILE *f = NULL;
3641
3642
3643 CSTAT(dump_acct_info);
3644
3645 if (shut_acct_n)
3646 {
3647 for (i = 0; i < shut_acct_n; i++)
3648 dump_session(&f, &shut_acct[i]);
3649
3650 shut_acct_n = 0;
3651 }
3652
3653 if (all)
3654 for (i = 1; i <= config->cluster_highest_sessionid; i++)
3655 dump_session(&f, &session[i]);
3656
3657 if (f)
3658 fclose(f);
3659 }
3660
3661 // Main program
3662 int main(int argc, char *argv[])
3663 {
3664 int i;
3665 int optdebug = 0;
3666 char *optconfig = CONFIGFILE;
3667
3668 time(&basetime); // start clock
3669
3670 // scan args
3671 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
3672 {
3673 switch (i)
3674 {
3675 case 'd':
3676 if (fork()) exit(0);
3677 setsid();
3678 freopen("/dev/null", "r", stdin);
3679 freopen("/dev/null", "w", stdout);
3680 freopen("/dev/null", "w", stderr);
3681 break;
3682 case 'v':
3683 optdebug++;
3684 break;
3685 case 'c':
3686 optconfig = optarg;
3687 break;
3688 case 'h':
3689 snprintf(hostname, sizeof(hostname), "%s", optarg);
3690 break;
3691 default:
3692 printf("Args are:\n"
3693 "\t-d\t\tDetach from terminal\n"
3694 "\t-c <file>\tConfig file\n"
3695 "\t-h <hostname>\tForce hostname\n"
3696 "\t-v\t\tDebug\n");
3697
3698 return (0);
3699 break;
3700 }
3701 }
3702
3703 // Start the timer routine off
3704 time(&time_now);
3705 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3706 signal(SIGALRM, sigalrm_handler);
3707 siginterrupt(SIGALRM, 0);
3708
3709 initplugins();
3710 initdata(optdebug, optconfig);
3711
3712 init_cli(hostname);
3713 read_config_file();
3714 init_tbf(config->num_tbfs);
3715
3716 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
3717 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
3718 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
3719 {
3720 struct rlimit rlim;
3721 rlim.rlim_cur = RLIM_INFINITY;
3722 rlim.rlim_max = RLIM_INFINITY;
3723 // Remove the maximum core size
3724 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
3725 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
3726
3727 // Make core dumps go to /tmp
3728 chdir("/tmp");
3729 }
3730
3731 if (config->scheduler_fifo)
3732 {
3733 int ret;
3734 struct sched_param params = {0};
3735 params.sched_priority = 1;
3736
3737 if (get_nprocs() < 2)
3738 {
3739 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
3740 config->scheduler_fifo = 0;
3741 }
3742 else
3743 {
3744 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
3745 {
3746 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
3747 }
3748 else
3749 {
3750 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
3751 config->scheduler_fifo = 0;
3752 }
3753 }
3754 }
3755
3756 /* Set up the cluster communications port. */
3757 if (cluster_init() < 0)
3758 exit(1);
3759
3760 #ifdef BGP
3761 signal(SIGPIPE, SIG_IGN);
3762 bgp_setup(config->as_number);
3763 bgp_add_route(config->bind_address, 0xffffffff);
3764 for (i = 0; i < BGP_NUM_PEERS; i++)
3765 {
3766 if (config->neighbour[i].name[0])
3767 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3768 config->neighbour[i].as, config->neighbour[i].keepalive,
3769 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3770 }
3771 #endif /* BGP */
3772
3773 inittun();
3774 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
3775
3776 initudp();
3777 initrad();
3778 initippool();
3779
3780 signal(SIGHUP, sighup_handler);
3781 signal(SIGTERM, sigterm_handler);
3782 signal(SIGINT, sigterm_handler);
3783 signal(SIGQUIT, sigquit_handler);
3784 signal(SIGCHLD, sigchild_handler);
3785
3786 // Prevent us from getting paged out
3787 if (config->lock_pages)
3788 {
3789 if (!mlockall(MCL_CURRENT))
3790 LOG(1, 0, 0, "Locking pages into memory\n");
3791 else
3792 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
3793 }
3794
3795 alarm(1);
3796
3797 // Drop privileges here
3798 if (config->target_uid > 0 && geteuid() == 0)
3799 setuid(config->target_uid);
3800
3801 mainloop();
3802
3803 #ifdef BGP
3804 /* try to shut BGP down cleanly; with luck the sockets will be
3805 writable since we're out of the select */
3806 for (i = 0; i < BGP_NUM_PEERS; i++)
3807 if (bgp_peers[i].state == Established)
3808 bgp_stop(&bgp_peers[i]);
3809 #endif /* BGP */
3810
3811 /* remove plugins (so cleanup code gets run) */
3812 plugins_done();
3813
3814 // Remove the PID file if we wrote it
3815 if (config->wrote_pid && *config->pid_file == '/')
3816 unlink(config->pid_file);
3817
3818 /* kill CLI children */
3819 signal(SIGTERM, SIG_IGN);
3820 kill(0, SIGTERM);
3821 return 0;
3822 }
3823
3824 static void sighup_handler(int sig)
3825 {
3826 if (log_stream)
3827 {
3828 if (log_stream != stderr)
3829 fclose(log_stream);
3830
3831 log_stream = NULL;
3832 }
3833
3834 read_config_file();
3835 }
3836
3837 static void sigalrm_handler(int sig)
3838 {
3839 // Log current traffic stats
3840
3841 snprintf(config->bandwidth, sizeof(config->bandwidth),
3842 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3843 (udp_rx / 1024.0 / 1024.0 * 8),
3844 (eth_tx / 1024.0 / 1024.0 * 8),
3845 (eth_rx / 1024.0 / 1024.0 * 8),
3846 (udp_tx / 1024.0 / 1024.0 * 8),
3847 ((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
3848 udp_rx_pkt, eth_rx_pkt);
3849
3850 udp_tx = udp_rx = 0;
3851 udp_rx_pkt = eth_rx_pkt = 0;
3852 eth_tx = eth_rx = 0;
3853
3854 if (config->dump_speed)
3855 printf("%s\n", config->bandwidth);
3856
3857 // Update the internal time counter
3858 time(&time_now);
3859 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3860 alarm(1);
3861
3862 {
3863 // Run timer hooks
3864 struct param_timer p = { time_now };
3865 run_plugins(PLUGIN_TIMER, &p);
3866 }
3867
3868 }
3869
3870 static void sigterm_handler(int sig)
3871 {
3872 LOG(1, 0, 0, "Shutting down cleanly\n");
3873 main_quit++;
3874 }
3875
3876 static void sigquit_handler(int sig)
3877 {
3878 int i;
3879
3880 LOG(1, 0, 0, "Shutting down without saving sessions\n");
3881
3882 if (config->cluster_iam_master)
3883 {
3884 for (i = 1; i < MAXSESSION; i++)
3885 {
3886 if (session[i].opened)
3887 sessionkill(i, "L2TPNS Closing");
3888 }
3889 for (i = 1; i < MAXTUNNEL; i++)
3890 {
3891 if (tunnel[i].ip || tunnel[i].state)
3892 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3893 }
3894 }
3895
3896 main_quit++;
3897 }
3898
3899 static void sigchild_handler(int sig)
3900 {
3901 while (waitpid(-1, NULL, WNOHANG) > 0)
3902 ;
3903 }
3904
3905 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
3906 {
3907 MD5_CTX ctx;
3908 *challenge_response = NULL;
3909
3910 if (!*config->l2tpsecret)
3911 {
3912 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
3913 return;
3914 }
3915
3916 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
3917
3918 *challenge_response = (char *)calloc(17, 1);
3919
3920 MD5Init(&ctx);
3921 MD5Update(&ctx, &id, 1);
3922 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
3923 MD5Update(&ctx, challenge, challenge_length);
3924 MD5Final(*challenge_response, &ctx);
3925
3926 return;
3927 }
3928
3929 static int facility_value(char *name)
3930 {
3931 int i;
3932 for (i = 0; facilitynames[i].c_name; i++)
3933 {
3934 if (strcmp(facilitynames[i].c_name, name) == 0)
3935 return facilitynames[i].c_val;
3936 }
3937 return 0;
3938 }
3939
3940 static void update_config()
3941 {
3942 int i;
3943 char *p;
3944 static int timeout = 0;
3945 static int interval = 0;
3946
3947 // Update logging
3948 closelog();
3949 syslog_log = 0;
3950 if (log_stream)
3951 {
3952 if (log_stream != stderr)
3953 fclose(log_stream);
3954
3955 log_stream = NULL;
3956 }
3957
3958 if (*config->log_filename)
3959 {
3960 if (strstr(config->log_filename, "syslog:") == config->log_filename)
3961 {
3962 char *p = config->log_filename + 7;
3963 if (*p)
3964 {
3965 openlog("l2tpns", LOG_PID, facility_value(p));
3966 syslog_log = 1;
3967 }
3968 }
3969 else if (strchr(config->log_filename, '/') == config->log_filename)
3970 {
3971 if ((log_stream = fopen((char *)(config->log_filename), "a")))
3972 {
3973 fseek(log_stream, 0, SEEK_END);
3974 setbuf(log_stream, NULL);
3975 }
3976 else
3977 {
3978 log_stream = stderr;
3979 setbuf(log_stream, NULL);
3980 }
3981 }
3982 }
3983 else
3984 {
3985 log_stream = stderr;
3986 setbuf(log_stream, NULL);
3987 }
3988
3989 // Update radius
3990 config->numradiusservers = 0;
3991 for (i = 0; i < MAXRADSERVER; i++)
3992 if (config->radiusserver[i])
3993 {
3994 config->numradiusservers++;
3995 // Set radius port: if not set, take the port from the
3996 // first radius server. For the first radius server,
3997 // take the #defined default value from l2tpns.h
3998
3999 // test twice, In case someone works with
4000 // a secondary radius server without defining
4001 // a primary one, this will work even then.
4002 if (i > 0 && !config->radiusport[i])
4003 config->radiusport[i] = config->radiusport[i-1];
4004 if (!config->radiusport[i])
4005 config->radiusport[i] = RADPORT;
4006 }
4007
4008 if (!config->numradiusservers)
4009 LOG(0, 0, 0, "No RADIUS servers defined!\n");
4010
4011 config->num_radfds = 1 << RADIUS_SHIFT;
4012
4013 // parse radius_authtypes_s
4014 config->radius_authtypes = config->radius_authprefer = 0;
4015 p = config->radius_authtypes_s;
4016 while (p && *p)
4017 {
4018 char *s = strpbrk(p, " \t,");
4019 int type = 0;
4020
4021 if (s)
4022 {
4023 *s++ = 0;
4024 while (*s == ' ' || *s == '\t')
4025 s++;
4026
4027 if (!*s)
4028 s = 0;
4029 }
4030
4031 if (!strncasecmp("chap", p, strlen(p)))
4032 type = AUTHCHAP;
4033 else if (!strncasecmp("pap", p, strlen(p)))
4034 type = AUTHPAP;
4035 else
4036 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
4037
4038 config->radius_authtypes |= type;
4039 if (!config->radius_authprefer)
4040 config->radius_authprefer = type;
4041
4042 p = s;
4043 }
4044
4045 if (!config->radius_authtypes)
4046 {
4047 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
4048 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
4049 }
4050
4051 // normalise radius_authtypes_s
4052 if (config->radius_authprefer == AUTHPAP)
4053 {
4054 strcpy(config->radius_authtypes_s, "pap");
4055 if (config->radius_authtypes & AUTHCHAP)
4056 strcat(config->radius_authtypes_s, ", chap");
4057 }
4058 else
4059 {
4060 strcpy(config->radius_authtypes_s, "chap");
4061 if (config->radius_authtypes & AUTHPAP)
4062 strcat(config->radius_authtypes_s, ", pap");
4063 }
4064
4065 // re-initialise the random number source
4066 initrandom(config->random_device);
4067
4068 // Update plugins
4069 for (i = 0; i < MAXPLUGINS; i++)
4070 {
4071 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4072 continue;
4073
4074 if (*config->plugins[i])
4075 {
4076 // Plugin added
4077 add_plugin(config->plugins[i]);
4078 }
4079 else if (*config->old_plugins[i])
4080 {
4081 // Plugin removed
4082 remove_plugin(config->old_plugins[i]);
4083 }
4084 }
4085
4086 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4087 if (!config->cleanup_interval) config->cleanup_interval = 10;
4088 if (!config->multi_read_count) config->multi_read_count = 10;
4089 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4090 if (!*config->cluster_interface)
4091 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4092
4093 if (!config->cluster_hb_interval)
4094 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4095
4096 if (!config->cluster_hb_timeout)
4097 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4098
4099 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4100 {
4101 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4102 // late, ensure we're sufficiently larger than that
4103 int t = 4 * config->cluster_hb_interval + 11;
4104
4105 if (config->cluster_hb_timeout < t)
4106 {
4107 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4108 config->cluster_hb_timeout = t;
4109 }
4110
4111 // Push timing changes to the slaves immediately if we're the master
4112 if (config->cluster_iam_master)
4113 cluster_heartbeat();
4114
4115 interval = config->cluster_hb_interval;
4116 timeout = config->cluster_hb_timeout;
4117 }
4118
4119 // Write PID file
4120 if (*config->pid_file == '/' && !config->wrote_pid)
4121 {
4122 FILE *f;
4123 if ((f = fopen(config->pid_file, "w")))
4124 {
4125 fprintf(f, "%d\n", getpid());
4126 fclose(f);
4127 config->wrote_pid = 1;
4128 }
4129 else
4130 {
4131 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4132 }
4133 }
4134
4135 config->reload_config = 0;
4136 }
4137
4138 static void read_config_file()
4139 {
4140 FILE *f;
4141
4142 if (!config->config_file) return;
4143 if (!(f = fopen(config->config_file, "r")))
4144 {
4145 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4146 return;
4147 }
4148
4149 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4150 cli_do_file(f);
4151 LOG(3, 0, 0, "Done reading config file\n");
4152 fclose(f);
4153 update_config();
4154 }
4155
4156 int sessionsetup(tunnelidt t, sessionidt s)
4157 {
4158 // A session now exists, set it up
4159 in_addr_t ip;
4160 char *user;
4161 sessionidt i;
4162 int r;
4163
4164 CSTAT(sessionsetup);
4165
4166 LOG(3, s, t, "Doing session setup for session\n");
4167
4168 if (!session[s].ip)
4169 {
4170 assign_ip_address(s);
4171 if (!session[s].ip)
4172 {
4173 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4174 sessionshutdown(s, "No IP addresses available.", 2, 7);
4175 return 0;
4176 }
4177 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4178 fmtaddr(htonl(session[s].ip), 0));
4179 }
4180
4181
4182 // Make sure this is right
4183 session[s].tunnel = t;
4184
4185 // zap old sessions with same IP and/or username
4186 // Don't kill gardened sessions - doing so leads to a DoS
4187 // from someone who doesn't need to know the password
4188 {
4189 ip = session[s].ip;
4190 user = session[s].user;
4191 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4192 {
4193 if (i == s) continue;
4194 if (!session[s].opened) continue;
4195 if (ip == session[i].ip)
4196 {
4197 sessionkill(i, "Duplicate IP address");
4198 continue;
4199 }
4200
4201 if (config->allow_duplicate_users) continue;
4202 if (session[s].walled_garden || session[i].walled_garden) continue;
4203 if (!strcasecmp(user, session[i].user))
4204 sessionkill(i, "Duplicate session for users");
4205 }
4206 }
4207
4208 {
4209 int routed = 0;
4210
4211 // Add the route for this session.
4212 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4213 {
4214 if ((session[s].ip & session[s].route[r].mask) ==
4215 (session[s].route[r].ip & session[s].route[r].mask))
4216 routed++;
4217
4218 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4219 }
4220
4221 // Static IPs need to be routed if not already
4222 // convered by a Framed-Route. Anything else is part
4223 // of the IP address pool and is already routed, it
4224 // just needs to be added to the IP cache.
4225 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4226 if (session[s].ip_pool_index == -1) // static ip
4227 {
4228 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4229 }
4230 else
4231 cache_ipmap(session[s].ip, s);
4232 }
4233
4234 if (!session[s].unique_id)
4235 {
4236 // did this session just finish radius?
4237 LOG(3, s, t, "Sending initial IPCP to client\n");
4238 sendipcp(t, s);
4239 session[s].unique_id = ++last_id;
4240 }
4241
4242 // Run the plugin's against this new session.
4243 {
4244 struct param_new_session data = { &tunnel[t], &session[s] };
4245 run_plugins(PLUGIN_NEW_SESSION, &data);
4246 }
4247
4248 // Allocate TBFs if throttled
4249 if (session[s].throttle_in || session[s].throttle_out)
4250 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4251
4252 session[s].last_packet = time_now;
4253
4254 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4255 fmtaddr(htonl(session[s].ip), 0),
4256 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4257
4258 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4259
4260 return 1; // RADIUS OK and IP allocated, done...
4261 }
4262
4263 //
4264 // This session just got dropped on us by the master or something.
4265 // Make sure our tables up up to date...
4266 //
4267 int load_session(sessionidt s, sessiont *new)
4268 {
4269 int i;
4270 int newip = 0;
4271
4272 // Sanity checks.
4273 if (new->ip_pool_index >= MAXIPPOOL ||
4274 new->tunnel >= MAXTUNNEL)
4275 {
4276 LOG(0, s, 0, "Strange session update received!\n");
4277 // FIXME! What to do here?
4278 return 0;
4279 }
4280
4281 //
4282 // Ok. All sanity checks passed. Now we're committed to
4283 // loading the new session.
4284 //
4285
4286 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4287
4288 // See if routes/ip cache need updating
4289 if (new->ip != session[s].ip)
4290 newip++;
4291
4292 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4293 if (new->route[i].ip != session[s].route[i].ip ||
4294 new->route[i].mask != session[s].route[i].mask)
4295 newip++;
4296
4297 // needs update
4298 if (newip)
4299 {
4300 int routed = 0;
4301
4302 // remove old routes...
4303 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4304 {
4305 if ((session[s].ip & session[s].route[i].mask) ==
4306 (session[s].route[i].ip & session[s].route[i].mask))
4307 routed++;
4308
4309 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4310 }
4311
4312 // ...ip
4313 if (session[s].ip)
4314 {
4315 if (session[s].ip_pool_index == -1) // static IP
4316 {
4317 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4318 }
4319 else // It's part of the IP pool, remove it manually.
4320 uncache_ipmap(session[s].ip);
4321 }
4322
4323 routed = 0;
4324
4325 // add new routes...
4326 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4327 {
4328 if ((new->ip & new->route[i].mask) ==
4329 (new->route[i].ip & new->route[i].mask))
4330 routed++;
4331
4332 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4333 }
4334
4335 // ...ip
4336 if (new->ip)
4337 {
4338 // If there's a new one, add it.
4339 if (new->ip_pool_index == -1)
4340 {
4341 if (!routed) routeset(s, new->ip, 0, 0, 1);
4342 }
4343 else
4344 cache_ipmap(new->ip, s);
4345 }
4346 }
4347
4348 // check v6 routing
4349 if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED))
4350 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4351
4352 // check filters
4353 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4354 {
4355 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4356 new->filter_in = 0;
4357 }
4358
4359 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4360 {
4361 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4362 new->filter_out = 0;
4363 }
4364
4365 if (new->filter_in != session[s].filter_in)
4366 {
4367 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4368 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4369 }
4370
4371 if (new->filter_out != session[s].filter_out)
4372 {
4373 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4374 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4375 }
4376
4377 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4378 // for walking the sessions to forward byte counts to the master.
4379 config->cluster_highest_sessionid = s;
4380
4381 // TEMP: old session struct used a uint32_t to define the throttle
4382 // speed for both up/down, new uses a uint16_t for each. Deal with
4383 // sessions from an old master for migration.
4384 if (new->throttle_out == 0 && new->tbf_out)
4385 new->throttle_out = new->throttle_in;
4386
4387 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4388
4389 // Do fixups into address pool.
4390 if (new->ip_pool_index != -1)
4391 fix_address_pool(s);
4392
4393 return 1;
4394 }
4395
4396 static void initplugins()
4397 {
4398 int i;
4399
4400 loaded_plugins = ll_init();
4401 // Initialize the plugins to nothing
4402 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4403 plugins[i] = ll_init();
4404 }
4405
4406 static void *open_plugin(char *plugin_name, int load)
4407 {
4408 char path[256] = "";
4409
4410 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4411 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4412 return dlopen(path, RTLD_NOW);
4413 }
4414
4415 // plugin callback to get a config value
4416 static void *getconfig(char *key, enum config_typet type)
4417 {
4418 int i;
4419
4420 for (i = 0; config_values[i].key; i++)
4421 {
4422 if (!strcmp(config_values[i].key, key))
4423 {
4424 if (config_values[i].type == type)
4425 return ((void *) config) + config_values[i].offset;
4426
4427 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4428 key, type, config_values[i].type);
4429
4430 return 0;
4431 }
4432 }
4433
4434 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4435 return 0;
4436 }
4437
4438 static int add_plugin(char *plugin_name)
4439 {
4440 static struct pluginfuncs funcs = {
4441 _log,
4442 _log_hex,
4443 fmtaddr,
4444 sessionbyuser,
4445 sessiontbysessionidt,
4446 sessionidtbysessiont,
4447 radiusnew,
4448 radiussend,
4449 getconfig,
4450 sessionshutdown,
4451 sessionkill,
4452 throttle_session,
4453 cluster_send_session,
4454 };
4455
4456 void *p = open_plugin(plugin_name, 1);
4457 int (*initfunc)(struct pluginfuncs *);
4458 int i;
4459
4460 if (!p)
4461 {
4462 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4463 return -1;
4464 }
4465
4466 if (ll_contains(loaded_plugins, p))
4467 {
4468 dlclose(p);
4469 return 0; // already loaded
4470 }
4471
4472 {
4473 int *v = dlsym(p, "plugin_api_version");
4474 if (!v || *v != PLUGIN_API_VERSION)
4475 {
4476 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4477 dlclose(p);
4478 return -1;
4479 }
4480 }
4481
4482 if ((initfunc = dlsym(p, "plugin_init")))
4483 {
4484 if (!initfunc(&funcs))
4485 {
4486 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4487 dlclose(p);
4488 return -1;
4489 }
4490 }
4491
4492 ll_push(loaded_plugins, p);
4493
4494 for (i = 0; i < max_plugin_functions; i++)
4495 {
4496 void *x;
4497 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4498 {
4499 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4500 ll_push(plugins[i], x);
4501 }
4502 }
4503
4504 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4505 return 1;
4506 }
4507
4508 static void run_plugin_done(void *plugin)
4509 {
4510 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4511
4512 if (donefunc)
4513 donefunc();
4514 }
4515
4516 static int remove_plugin(char *plugin_name)
4517 {
4518 void *p = open_plugin(plugin_name, 0);
4519 int loaded = 0;
4520
4521 if (!p)
4522 return -1;
4523
4524 if (ll_contains(loaded_plugins, p))
4525 {
4526 int i;
4527 for (i = 0; i < max_plugin_functions; i++)
4528 {
4529 void *x;
4530 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4531 ll_delete(plugins[i], x);
4532 }
4533
4534 ll_delete(loaded_plugins, p);
4535 run_plugin_done(p);
4536 loaded = 1;
4537 }
4538
4539 dlclose(p);
4540 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4541 return loaded;
4542 }
4543
4544 int run_plugins(int plugin_type, void *data)
4545 {
4546 int (*func)(void *data);
4547
4548 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4549 return PLUGIN_RET_ERROR;
4550
4551 ll_reset(plugins[plugin_type]);
4552 while ((func = ll_next(plugins[plugin_type])))
4553 {
4554 int r = func(data);
4555
4556 if (r != PLUGIN_RET_OK)
4557 return r; // stop here
4558 }
4559
4560 return PLUGIN_RET_OK;
4561 }
4562
4563 static void plugins_done()
4564 {
4565 void *p;
4566
4567 ll_reset(loaded_plugins);
4568 while ((p = ll_next(loaded_plugins)))
4569 run_plugin_done(p);
4570 }
4571
4572 static void processcontrol(uint8_t * buf, int len, struct sockaddr_in *addr, int alen)
4573 {
4574 struct nsctl request;
4575 struct nsctl response;
4576 int type = unpack_control(&request, buf, len);
4577 int r;
4578 void *p;
4579
4580 if (log_stream && config->debug >= 4)
4581 {
4582 if (type < 0)
4583 {
4584 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4585 fmtaddr(addr->sin_addr.s_addr, 0), type);
4586 }
4587 else
4588 {
4589 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4590 dump_control(&request, log_stream);
4591 }
4592 }
4593
4594 switch (type)
4595 {
4596 case NSCTL_REQ_LOAD:
4597 if (request.argc != 1)
4598 {
4599 response.type = NSCTL_RES_ERR;
4600 response.argc = 1;
4601 response.argv[0] = "name of plugin required";
4602 }
4603 else if ((r = add_plugin(request.argv[0])) < 1)
4604 {
4605 response.type = NSCTL_RES_ERR;
4606 response.argc = 1;
4607 response.argv[0] = !r
4608 ? "plugin already loaded"
4609 : "error loading plugin";
4610 }
4611 else
4612 {
4613 response.type = NSCTL_RES_OK;
4614 response.argc = 0;
4615 }
4616
4617 break;
4618
4619 case NSCTL_REQ_UNLOAD:
4620 if (request.argc != 1)
4621 {
4622 response.type = NSCTL_RES_ERR;
4623 response.argc = 1;
4624 response.argv[0] = "name of plugin required";
4625 }
4626 else if ((r = remove_plugin(request.argv[0])) < 1)
4627 {
4628 response.type = NSCTL_RES_ERR;
4629 response.argc = 1;
4630 response.argv[0] = !r
4631 ? "plugin not loaded"
4632 : "plugin not found";
4633 }
4634 else
4635 {
4636 response.type = NSCTL_RES_OK;
4637 response.argc = 0;
4638 }
4639
4640 break;
4641
4642 case NSCTL_REQ_HELP:
4643 response.type = NSCTL_RES_OK;
4644 response.argc = 0;
4645
4646 ll_reset(loaded_plugins);
4647 while ((p = ll_next(loaded_plugins)))
4648 {
4649 char **help = dlsym(p, "plugin_control_help");
4650 while (response.argc < 0xff && help && *help)
4651 response.argv[response.argc++] = *help++;
4652 }
4653
4654 break;
4655
4656 case NSCTL_REQ_CONTROL:
4657 {
4658 struct param_control param = {
4659 config->cluster_iam_master,
4660 request.argc,
4661 request.argv,
4662 0,
4663 NULL,
4664 };
4665
4666 int r = run_plugins(PLUGIN_CONTROL, &param);
4667
4668 if (r == PLUGIN_RET_ERROR)
4669 {
4670 response.type = NSCTL_RES_ERR;
4671 response.argc = 1;
4672 response.argv[0] = param.additional
4673 ? param.additional
4674 : "error returned by plugin";
4675 }
4676 else if (r == PLUGIN_RET_NOTMASTER)
4677 {
4678 static char msg[] = "must be run on master: 000.000.000.000";
4679
4680 response.type = NSCTL_RES_ERR;
4681 response.argc = 1;
4682 if (config->cluster_master_address)
4683 {
4684 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
4685 response.argv[0] = msg;
4686 }
4687 else
4688 {
4689 response.argv[0] = "must be run on master: none elected";
4690 }
4691 }
4692 else if (!(param.response & NSCTL_RESPONSE))
4693 {
4694 response.type = NSCTL_RES_ERR;
4695 response.argc = 1;
4696 response.argv[0] = param.response
4697 ? "unrecognised response value from plugin"
4698 : "unhandled action";
4699 }
4700 else
4701 {
4702 response.type = param.response;
4703 response.argc = 0;
4704 if (param.additional)
4705 {
4706 response.argc = 1;
4707 response.argv[0] = param.additional;
4708 }
4709 }
4710 }
4711
4712 break;
4713
4714 default:
4715 response.type = NSCTL_RES_ERR;
4716 response.argc = 1;
4717 response.argv[0] = "error unpacking control packet";
4718 }
4719
4720 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
4721 if (!buf)
4722 {
4723 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
4724 return;
4725 }
4726
4727 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
4728 if (r > 0)
4729 {
4730 sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
4731 if (log_stream && config->debug >= 4)
4732 {
4733 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4734 dump_control(&response, log_stream);
4735 }
4736 }
4737 else
4738 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
4739 fmtaddr(addr->sin_addr.s_addr, 0), r);
4740
4741 free(buf);
4742 }
4743
4744 static tunnelidt new_tunnel()
4745 {
4746 tunnelidt i;
4747 for (i = 1; i < MAXTUNNEL; i++)
4748 {
4749 if (tunnel[i].state == TUNNELFREE)
4750 {
4751 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
4752 if (i > config->cluster_highest_tunnelid)
4753 config->cluster_highest_tunnelid = i;
4754 return i;
4755 }
4756 }
4757 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
4758 return 0;
4759 }
4760
4761 //
4762 // We're becoming the master. Do any required setup..
4763 //
4764 // This is principally telling all the plugins that we're
4765 // now a master, and telling them about all the sessions
4766 // that are active too..
4767 //
4768 void become_master(void)
4769 {
4770 int s, i;
4771 run_plugins(PLUGIN_BECOME_MASTER, NULL);
4772
4773 // running a bunch of iptables commands is slow and can cause
4774 // the master to drop tunnels on takeover--kludge around the
4775 // problem by forking for the moment (note: race)
4776 if (!fork_and_close())
4777 {
4778 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4779 {
4780 if (!session[s].opened) // Not an in-use session.
4781 continue;
4782
4783 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
4784 }
4785 exit(0);
4786 }
4787
4788 // add radius fds
4789 for (i = 0; i < config->num_radfds; i++)
4790 {
4791 FD_SET(radfds[i], &readset);
4792 if (radfds[i] > readset_n)
4793 readset_n = radfds[i];
4794 }
4795 }
4796
4797 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
4798 {
4799 int s, i;
4800 int count = 0;
4801 int buckets[64];
4802
4803 if (CLI_HELP_REQUESTED)
4804 return CLI_HELP_NO_ARGS;
4805
4806 time(&time_now);
4807 for (i = 0; i < 64;++i) buckets[i] = 0;
4808
4809 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4810 {
4811 int idle;
4812 if (!session[s].opened)
4813 continue;
4814
4815 idle = time_now - session[s].last_packet;
4816 idle /= 5 ; // In multiples of 5 seconds.
4817 if (idle < 0)
4818 idle = 0;
4819 if (idle > 63)
4820 idle = 63;
4821
4822 ++count;
4823 ++buckets[idle];
4824 }
4825
4826 for (i = 0; i < 63; ++i)
4827 {
4828 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
4829 }
4830 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
4831 cli_print(cli, "%d total sessions open.", count);
4832 return CLI_OK;
4833 }
4834
4835 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
4836 {
4837 int s, i;
4838 int count = 0;
4839 int buckets[64];
4840
4841 if (CLI_HELP_REQUESTED)
4842 return CLI_HELP_NO_ARGS;
4843
4844 time(&time_now);
4845 for (i = 0; i < 64;++i) buckets[i] = 0;
4846
4847 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4848 {
4849 int open = 0, d;
4850 if (!session[s].opened)
4851 continue;
4852
4853 d = time_now - session[s].opened;
4854 if (d < 0)
4855 d = 0;
4856 while (d > 1 && open < 32)
4857 {
4858 ++open;
4859 d >>= 1; // half.
4860 }
4861 ++count;
4862 ++buckets[open];
4863 }
4864
4865 s = 1;
4866 for (i = 0; i < 30; ++i)
4867 {
4868 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
4869 s <<= 1;
4870 }
4871 cli_print(cli, "%d total sessions open.", count);
4872 return CLI_OK;
4873 }
4874
4875 /* Unhide an avp.
4876 *
4877 * This unencodes the AVP using the L2TP secret and the previously
4878 * stored random vector. It overwrites the hidden data with the
4879 * unhidden AVP subformat.
4880 */
4881 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
4882 {
4883 MD5_CTX ctx;
4884 uint8_t digest[16];
4885 uint8_t *last;
4886 size_t d = 0;
4887
4888 // Compute initial pad
4889 MD5Init(&ctx);
4890 MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
4891 MD5Update(&ctx, (uint8_t) type & 0xff, 1);
4892 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4893 MD5Update(&ctx, vector, vec_len);
4894 MD5Final(digest, &ctx);
4895
4896 // pointer to last decoded 16 octets
4897 last = value;
4898
4899 while (len > 0)
4900 {
4901 // calculate a new pad based on the last decoded block
4902 if (d >= sizeof(digest))
4903 {
4904 MD5Init(&ctx);
4905 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4906 MD5Update(&ctx, last, sizeof(digest));
4907 MD5Final(digest, &ctx);
4908
4909 d = 0;
4910 last = value;
4911 }
4912
4913 *value++ ^= digest[d++];
4914 len--;
4915 }
4916 }
4917
4918 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
4919 {
4920 switch (p->op)
4921 {
4922 case FILTER_PORT_OP_EQ: return port == p->port;
4923 case FILTER_PORT_OP_NEQ: return port != p->port;
4924 case FILTER_PORT_OP_GT: return port > p->port;
4925 case FILTER_PORT_OP_LT: return port < p->port;
4926 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
4927 }
4928
4929 return 0;
4930 }
4931
4932 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
4933 {
4934 switch (op)
4935 {
4936 case FILTER_FLAG_OP_ANY:
4937 return (flags & sflags) || (~flags & cflags);
4938
4939 case FILTER_FLAG_OP_ALL:
4940 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
4941
4942 case FILTER_FLAG_OP_EST:
4943 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
4944 }
4945
4946 return 0;
4947 }
4948
4949 int ip_filter(uint8_t *buf, int len, uint8_t filter)
4950 {
4951 uint16_t frag_offset;
4952 uint8_t proto;
4953 in_addr_t src_ip;
4954 in_addr_t dst_ip;
4955 uint16_t src_port = 0;
4956 uint16_t dst_port = 0;
4957 uint8_t flags = 0;
4958 ip_filter_rulet *rule;
4959
4960 if (len < 20) // up to end of destination address
4961 return 0;
4962
4963 if ((*buf >> 4) != 4) // IPv4
4964 return 0;
4965
4966 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
4967 proto = buf[9];
4968 src_ip = *(in_addr_t *) (buf + 12);
4969 dst_ip = *(in_addr_t *) (buf + 16);
4970
4971 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
4972 {
4973 int l = (buf[0] & 0xf) * 4; // length of IP header
4974 if (len < l + 4) // ports
4975 return 0;
4976
4977 src_port = ntohs(*(uint16_t *) (buf + l));
4978 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
4979 if (proto == IPPROTO_TCP)
4980 {
4981 if (len < l + 14) // flags
4982 return 0;
4983
4984 flags = buf[l + 13] & 0x3f;
4985 }
4986 }
4987
4988 for (rule = ip_filters[filter].rules; rule->action; rule++)
4989 {
4990 if (rule->proto != IPPROTO_IP && proto != rule->proto)
4991 continue;
4992
4993 if (rule->src_wild != INADDR_BROADCAST &&
4994 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
4995 continue;
4996
4997 if (rule->dst_wild != INADDR_BROADCAST &&
4998 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
4999 continue;
5000
5001 if (frag_offset)
5002 {
5003 if (!rule->frag || rule->action == FILTER_ACTION_DENY)
5004 continue;
5005 }
5006 else
5007 {
5008 if (rule->frag)
5009 continue;
5010
5011 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
5012 {
5013 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
5014 continue;
5015
5016 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
5017 continue;
5018
5019 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
5020 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
5021 continue;
5022 }
5023 }
5024
5025 // matched
5026 rule->counter++;
5027 return rule->action == FILTER_ACTION_PERMIT;
5028 }
5029
5030 // default deny
5031 return 0;
5032 }