28eca3b64cb5236e58f210a089f50f2969cc9ef1
[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 1.96 2005/05/07 08:17:25 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("bind_address", bind_address, IPv4),
117 CONFIG("peer_address", peer_address, IPv4),
118 CONFIG("send_garp", send_garp, BOOL),
119 CONFIG("throttle_speed", rl_rate, UNSIGNED_LONG),
120 CONFIG("throttle_buckets", num_tbfs, INT),
121 CONFIG("accounting_dir", accounting_dir, STRING),
122 CONFIG("setuid", target_uid, INT),
123 CONFIG("dump_speed", dump_speed, BOOL),
124 CONFIG("cleanup_interval", cleanup_interval, INT),
125 CONFIG("multi_read_count", multi_read_count, INT),
126 CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
127 CONFIG("lock_pages", lock_pages, BOOL),
128 CONFIG("icmp_rate", icmp_rate, INT),
129 CONFIG("packet_limit", max_packets, INT),
130 CONFIG("cluster_address", cluster_address, IPv4),
131 CONFIG("cluster_interface", cluster_interface, STRING),
132 CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
133 CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
134 CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
135 { NULL, 0, 0, 0 },
136 };
137
138 static char *plugin_functions[] = {
139 NULL,
140 "plugin_pre_auth",
141 "plugin_post_auth",
142 "plugin_packet_rx",
143 "plugin_packet_tx",
144 "plugin_timer",
145 "plugin_new_session",
146 "plugin_kill_session",
147 "plugin_control",
148 "plugin_radius_response",
149 "plugin_become_master",
150 "plugin_new_session_master",
151 };
152
153 #define max_plugin_functions (sizeof(plugin_functions) / sizeof(char *))
154
155 // Counters for shutdown sessions
156 static sessiont shut_acct[8192];
157 static sessionidt shut_acct_n = 0;
158
159 tunnelt *tunnel = NULL; // Array of tunnel structures.
160 sessiont *session = NULL; // Array of session structures.
161 sessionlocalt *sess_local = NULL; // Array of local per-session counters.
162 radiust *radius = NULL; // Array of radius structures.
163 ippoolt *ip_address_pool = NULL; // Array of dynamic IP addresses.
164 ip_filtert *ip_filters = NULL; // Array of named filters.
165 static controlt *controlfree = 0;
166 struct Tstats *_statistics = NULL;
167 #ifdef RINGBUFFER
168 struct Tringbuffer *ringbuffer = NULL;
169 #endif
170
171 static void cache_ipmap(in_addr_t ip, int s);
172 static void uncache_ipmap(in_addr_t ip);
173 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s);
174 static void free_ip_address(sessionidt s);
175 static void dump_acct_info(int all);
176 static void sighup_handler(int sig);
177 static void sigalrm_handler(int sig);
178 static void sigterm_handler(int sig);
179 static void sigquit_handler(int sig);
180 static void sigchild_handler(int sig);
181 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response);
182 static void update_config(void);
183 static void read_config_file(void);
184 static void initplugins(void);
185 static int add_plugin(char *plugin_name);
186 static int remove_plugin(char *plugin_name);
187 static void plugins_done(void);
188 static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
189 static tunnelidt new_tunnel(void);
190 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
191
192 // return internal time (10ths since process startup)
193 static clockt now(void)
194 {
195 struct timeval t;
196 gettimeofday(&t, 0);
197 return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
198 }
199
200 // work out a retry time based on try number
201 // This is a straight bounded exponential backoff.
202 // Maximum re-try time is 32 seconds. (2^5).
203 clockt backoff(uint8_t try)
204 {
205 if (try > 5) try = 5; // max backoff
206 return now() + 10 * (1 << try);
207 }
208
209
210 //
211 // Log a debug message. Typically called via the LOG macro
212 //
213 void _log(int level, sessionidt s, tunnelidt t, const char *format, ...)
214 {
215 static char message[65536] = {0};
216 va_list ap;
217
218 #ifdef RINGBUFFER
219 if (ringbuffer)
220 {
221 if (++ringbuffer->tail >= RINGBUFFER_SIZE)
222 ringbuffer->tail = 0;
223 if (ringbuffer->tail == ringbuffer->head)
224 if (++ringbuffer->head >= RINGBUFFER_SIZE)
225 ringbuffer->head = 0;
226
227 ringbuffer->buffer[ringbuffer->tail].level = level;
228 ringbuffer->buffer[ringbuffer->tail].session = s;
229 ringbuffer->buffer[ringbuffer->tail].tunnel = t;
230 va_start(ap, format);
231 vsnprintf(ringbuffer->buffer[ringbuffer->tail].message, 4095, format, ap);
232 va_end(ap);
233 }
234 #endif
235
236 if (config->debug < level) return;
237
238 va_start(ap, format);
239 vsnprintf(message, sizeof(message), format, ap);
240
241 if (log_stream)
242 fprintf(log_stream, "%s %02d/%02d %s", time_now_string, t, s, message);
243 else if (syslog_log)
244 syslog(level + 2, "%02d/%02d %s", t, s, message); // We don't need LOG_EMERG or LOG_ALERT
245
246 va_end(ap);
247 }
248
249 void _log_hex(int level, const char *title, const char *data, int maxsize)
250 {
251 int i, j;
252 const uint8_t *d = (const uint8_t *) data;
253
254 if (config->debug < level) return;
255
256 // No support for _log_hex to syslog
257 if (log_stream)
258 {
259 _log(level, 0, 0, "%s (%d bytes):\n", title, maxsize);
260 setvbuf(log_stream, NULL, _IOFBF, 16384);
261
262 for (i = 0; i < maxsize; )
263 {
264 fprintf(log_stream, "%4X: ", i);
265 for (j = i; j < maxsize && j < (i + 16); j++)
266 {
267 fprintf(log_stream, "%02X ", d[j]);
268 if (j == i + 7)
269 fputs(": ", log_stream);
270 }
271
272 for (; j < i + 16; j++)
273 {
274 fputs(" ", log_stream);
275 if (j == i + 7)
276 fputs(": ", log_stream);
277 }
278
279 fputs(" ", log_stream);
280 for (j = i; j < maxsize && j < (i + 16); j++)
281 {
282 if (d[j] >= 0x20 && d[j] < 0x7f && d[j] != 0x20)
283 fputc(d[j], log_stream);
284 else
285 fputc('.', log_stream);
286
287 if (j == i + 7)
288 fputs(" ", log_stream);
289 }
290
291 i = j;
292 fputs("\n", log_stream);
293 }
294
295 fflush(log_stream);
296 setbuf(log_stream, NULL);
297 }
298 }
299
300 // initialise the random generator
301 static void initrandom(char *source)
302 {
303 static char path[sizeof(config->random_device)] = "*undefined*";
304
305 // reinitialise only if we are forced to do so or if the config has changed
306 if (source && !strncmp(path, source, sizeof(path)))
307 return;
308
309 // close previous source, if any
310 if (rand_fd >= 0) close(rand_fd);
311
312 rand_fd = -1;
313
314 if (source)
315 {
316 // register changes
317 snprintf(path, sizeof(path), "%s", source);
318
319 if (*path == '/')
320 {
321 rand_fd = open(path, O_RDONLY|O_NONBLOCK);
322 if (rand_fd < 0)
323 LOG(0, 0, 0, "Error opening the random device %s: %s\n",
324 path, strerror(errno));
325 }
326 }
327
328 // no source: seed prng
329 {
330 unsigned seed = time_now ^ getpid();
331 LOG(4, 0, 0, "Seeding the pseudo random generator: %u\n", seed);
332 srand(seed);
333 }
334 }
335
336 // fill buffer with random data
337 void random_data(uint8_t *buf, int len)
338 {
339 int n = 0;
340
341 CSTAT(random_data);
342 if (rand_fd >= 0)
343 {
344 n = read(rand_fd, buf, len);
345 if (n >= len) return;
346 if (n < 0)
347 {
348 if (errno != EAGAIN)
349 {
350 LOG(0, 0, 0, "Error reading from random source: %s\n",
351 strerror(errno));
352
353 // fall back to rand()
354 initrandom(0);
355 }
356
357 n = 0;
358 }
359 }
360
361 // append missing data
362 while (n < len)
363 // not using the low order bits from the prng stream
364 buf[n++] = (rand() >> 4) & 0xff;
365 }
366
367 // Add a route
368 //
369 // This adds it to the routing table, advertises it
370 // via BGP if enabled, and stuffs it into the
371 // 'sessionbyip' cache.
372 //
373 // 'ip' and 'mask' must be in _host_ order.
374 //
375 static void routeset(sessionidt s, in_addr_t ip, in_addr_t mask, in_addr_t gw, int add)
376 {
377 struct rtentry r;
378 int i;
379
380 if (!mask) mask = 0xffffffff;
381
382 ip &= mask; // Force the ip to be the first one in the route.
383
384 memset(&r, 0, sizeof(r));
385 r.rt_dev = config->tundevice;
386 r.rt_dst.sa_family = AF_INET;
387 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(ip);
388 r.rt_gateway.sa_family = AF_INET;
389 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr) = htonl(gw);
390 r.rt_genmask.sa_family = AF_INET;
391 *(uint32_t *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
392 r.rt_flags = (RTF_UP | RTF_STATIC);
393 if (gw)
394 r.rt_flags |= RTF_GATEWAY;
395 else if (mask == 0xffffffff)
396 r.rt_flags |= RTF_HOST;
397
398 LOG(1, s, 0, "Route %s %s/%s%s%s\n", add ? "add" : "del",
399 fmtaddr(htonl(ip), 0), fmtaddr(htonl(mask), 1),
400 gw ? " via" : "", gw ? fmtaddr(htonl(gw), 2) : "");
401
402 if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0)
403 LOG(0, 0, 0, "routeset() error in ioctl: %s\n", strerror(errno));
404
405 #ifdef BGP
406 if (add)
407 bgp_add_route(htonl(ip), htonl(mask));
408 else
409 bgp_del_route(htonl(ip), htonl(mask));
410 #endif /* BGP */
411
412 // Add/Remove the IPs to the 'sessionbyip' cache.
413 // Note that we add the zero address in the case of
414 // a network route. Roll on CIDR.
415
416 // Note that 's == 0' implies this is the address pool.
417 // We still cache it here, because it will pre-fill
418 // the malloc'ed tree.
419
420 if (s)
421 {
422 if (!add) // Are we deleting a route?
423 s = 0; // Caching the session as '0' is the same as uncaching.
424
425 for (i = ip; (i&mask) == (ip&mask) ; ++i)
426 cache_ipmap(i, s);
427 }
428 }
429
430 void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add)
431 {
432 struct in6_rtmsg rt;
433 char ipv6addr[INET6_ADDRSTRLEN];
434
435 if (ifr6fd < 0)
436 {
437 LOG(0, 0, 0, "Asked to set IPv6 route, but IPv6 not setup.\n");
438 return;
439 }
440
441 memset(&rt, 0, sizeof(rt));
442
443 memcpy(&rt.rtmsg_dst, &ip, sizeof(struct in6_addr));
444 rt.rtmsg_dst_len = prefixlen;
445 rt.rtmsg_metric = 1;
446 rt.rtmsg_flags = RTF_UP;
447 rt.rtmsg_ifindex = tunidx;
448
449 LOG(1, 0, 0, "Route %s %s/%d\n",
450 add ? "add" : "del",
451 inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN),
452 prefixlen);
453
454 if (ioctl(ifr6fd, add ? SIOCADDRT : SIOCDELRT, (void *) &rt) < 0)
455 LOG(0, 0, 0, "route6set() error in ioctl: %s\n",
456 strerror(errno));
457
458 // FIXME: need to add BGP routing (RFC2858)
459
460 if (s)
461 {
462 if (!add) // Are we deleting a route?
463 s = 0; // Caching the session as '0' is the same as uncaching.
464
465 cache_ipv6map(ip, prefixlen, s);
466 }
467
468 return;
469 }
470
471 // defined in linux/ipv6.h, but tricky to include from user-space
472 // TODO: move routing to use netlink rather than ioctl
473 struct in6_ifreq {
474 struct in6_addr ifr6_addr;
475 __u32 ifr6_prefixlen;
476 unsigned int ifr6_ifindex;
477 };
478
479 //
480 // Set up TUN interface
481 static void inittun(void)
482 {
483 struct ifreq ifr;
484 struct in6_ifreq ifr6;
485 struct sockaddr_in sin = {0};
486 memset(&ifr, 0, sizeof(ifr));
487 ifr.ifr_flags = IFF_TUN;
488
489 tunfd = open(TUNDEVICE, O_RDWR);
490 if (tunfd < 0)
491 { // fatal
492 LOG(0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
493 exit(1);
494 }
495 {
496 int flags = fcntl(tunfd, F_GETFL, 0);
497 fcntl(tunfd, F_SETFL, flags | O_NONBLOCK);
498 }
499 if (ioctl(tunfd, TUNSETIFF, (void *) &ifr) < 0)
500 {
501 LOG(0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
502 exit(1);
503 }
504 assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
505 strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
506 ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
507
508 sin.sin_family = AF_INET;
509 sin.sin_addr.s_addr = config->bind_address ? config->bind_address : 0x01010101; // 1.1.1.1
510 memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));
511
512 if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0)
513 {
514 LOG(0, 0, 0, "Error setting tun address: %s\n", strerror(errno));
515 exit(1);
516 }
517 /* Bump up the qlen to deal with bursts from the network */
518 ifr.ifr_qlen = 1000;
519 if (ioctl(ifrfd, SIOCSIFTXQLEN, (void *) &ifr) < 0)
520 {
521 LOG(0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
522 exit(1);
523 }
524 ifr.ifr_flags = IFF_UP;
525 if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
526 {
527 LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
528 exit(1);
529 }
530 if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
531 {
532 LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
533 exit(1);
534 }
535 tunidx = ifr.ifr_ifindex;
536
537 // Only setup IPv6 on the tun device if we have a configured prefix
538 if (config->ipv6_prefix.s6_addr[0] > 0) {
539 ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0);
540
541 // Link local address is FE80::1
542 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
543 ifr6.ifr6_addr.s6_addr[0] = 0xFE;
544 ifr6.ifr6_addr.s6_addr[1] = 0x80;
545 ifr6.ifr6_addr.s6_addr[15] = 1;
546 ifr6.ifr6_prefixlen = 64;
547 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
548 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
549 {
550 LOG(0, 0, 0, "Error setting tun IPv6 link local address:"
551 " %s\n", strerror(errno));
552 }
553
554 // Global address is prefix::1
555 memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
556 ifr6.ifr6_addr = config->ipv6_prefix;
557 ifr6.ifr6_addr.s6_addr[15] = 1;
558 ifr6.ifr6_prefixlen = 64;
559 ifr6.ifr6_ifindex = ifr.ifr_ifindex;
560 if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
561 {
562 LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n",
563 strerror(errno));
564 }
565 }
566 }
567
568 // set up UDP port
569 static void initudp(void)
570 {
571 int on = 1;
572 struct sockaddr_in addr;
573
574 // Tunnel
575 memset(&addr, 0, sizeof(addr));
576 addr.sin_family = AF_INET;
577 addr.sin_port = htons(L2TPPORT);
578 addr.sin_addr.s_addr = config->bind_address;
579 udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
580 setsockopt(udpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
581 {
582 int flags = fcntl(udpfd, F_GETFL, 0);
583 fcntl(udpfd, F_SETFL, flags | O_NONBLOCK);
584 }
585 if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
586 {
587 LOG(0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
588 exit(1);
589 }
590 snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
591
592 // Control
593 memset(&addr, 0, sizeof(addr));
594 addr.sin_family = AF_INET;
595 addr.sin_port = htons(NSCTL_PORT);
596 controlfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
597 setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
598 if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
599 {
600 LOG(0, 0, 0, "Error in control bind: %s\n", strerror(errno));
601 exit(1);
602 }
603 }
604
605 //
606 // Find session by IP, < 1 for not found
607 //
608 // Confusingly enough, this 'ip' must be
609 // in _network_ order. This being the common
610 // case when looking it up from IP packet headers.
611 //
612 // We actually use this cache for two things.
613 // #1. For used IP addresses, this maps to the
614 // session ID that it's used by.
615 // #2. For un-used IP addresses, this maps to the
616 // index into the pool table that contains that
617 // IP address.
618 //
619
620 static int lookup_ipmap(in_addr_t ip)
621 {
622 uint8_t *a = (uint8_t *) &ip;
623 uint8_t **d = (uint8_t **) ip_hash;
624
625 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
626 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
627 if (!(d = (uint8_t **) d[(size_t) *a++])) return 0;
628
629 return (int) (intptr_t) d[(size_t) *a];
630 }
631
632 static int lookup_ipv6map(struct in6_addr ip)
633 {
634 struct ipv6radix *curnode;
635 int i;
636 int s;
637 char ipv6addr[INET6_ADDRSTRLEN];
638
639 curnode = &ipv6_hash[ip.s6_addr[0]];
640 i = 1;
641 s = curnode->sess;
642
643 while (s == 0 && i < 15 && curnode->branch != NULL)
644 {
645 curnode = &curnode->branch[ip.s6_addr[i]];
646 s = curnode->sess;
647 i++;
648 }
649
650 LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
651 inet_ntop(AF_INET6, &ip, ipv6addr,
652 INET6_ADDRSTRLEN),
653 s);
654
655 return s;
656 }
657
658 sessionidt sessionbyip(in_addr_t ip)
659 {
660 int s = lookup_ipmap(ip);
661 CSTAT(sessionbyip);
662
663 if (s > 0 && s < MAXSESSION && session[s].opened)
664 return (sessionidt) s;
665
666 return 0;
667 }
668
669 sessionidt sessionbyipv6(struct in6_addr ip)
670 {
671 int s;
672 CSTAT(sessionbyipv6);
673
674 if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
675 (ip.s6_addr[0] == 0xFE && ip.s6_addr[1] == 0x80 &&
676 (ip.s6_addr16[1] == ip.s6_addr16[2] == ip.s6_addr16[3] == 0))) {
677 s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
678 } else {
679 s = lookup_ipv6map(ip);
680 }
681
682 if (s > 0 && s < MAXSESSION && session[s].opened)
683 return s;
684
685 return 0;
686 }
687
688 //
689 // Take an IP address in HOST byte order and
690 // add it to the sessionid by IP cache.
691 //
692 // (It's actually cached in network order)
693 //
694 static void cache_ipmap(in_addr_t ip, int s)
695 {
696 in_addr_t nip = htonl(ip); // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
697 uint8_t *a = (uint8_t *) &nip;
698 uint8_t **d = (uint8_t **) ip_hash;
699 int i;
700
701 for (i = 0; i < 3; i++)
702 {
703 if (!d[(size_t) a[i]])
704 {
705 if (!(d[(size_t) a[i]] = calloc(256, sizeof(void *))))
706 return;
707 }
708
709 d = (uint8_t **) d[(size_t) a[i]];
710 }
711
712 d[(size_t) a[3]] = (uint8_t *) (intptr_t) s;
713
714 if (s > 0)
715 LOG(4, s, session[s].tunnel, "Caching ip address %s\n", fmtaddr(nip, 0));
716
717 else if (s == 0)
718 LOG(4, 0, 0, "Un-caching ip address %s\n", fmtaddr(nip, 0));
719 // else a map to an ip pool index.
720 }
721
722 static void uncache_ipmap(in_addr_t ip)
723 {
724 cache_ipmap(ip, 0); // Assign it to the NULL session.
725 }
726
727 static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
728 {
729 int i;
730 int bytes;
731 struct ipv6radix *curnode;
732 char ipv6addr[INET6_ADDRSTRLEN];
733
734 curnode = &ipv6_hash[ip.s6_addr[0]];
735
736 bytes = prefixlen >> 3;
737 i = 1;
738 while (i < bytes) {
739 if (curnode->branch == NULL)
740 {
741 if (!(curnode->branch = calloc(256,
742 sizeof (struct ipv6radix))))
743 return;
744 }
745 curnode = &curnode->branch[ip.s6_addr[i]];
746 i++;
747 }
748
749 curnode->sess = s;
750
751 if (s > 0)
752 LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
753 inet_ntop(AF_INET6, &ip, ipv6addr,
754 INET6_ADDRSTRLEN),
755 prefixlen);
756 else if (s == 0)
757 LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
758 inet_ntop(AF_INET6, &ip, ipv6addr,
759 INET6_ADDRSTRLEN),
760 prefixlen);
761 }
762
763 //
764 // CLI list to dump current ipcache.
765 //
766 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
767 {
768 char **d = (char **) ip_hash, **e, **f, **g;
769 int i, j, k, l;
770 int count = 0;
771
772 if (CLI_HELP_REQUESTED)
773 return CLI_HELP_NO_ARGS;
774
775 cli_print(cli, "%7s %s", "Sess#", "IP Address");
776
777 for (i = 0; i < 256; ++i)
778 {
779 if (!d[i])
780 continue;
781 e = (char **) d[i];
782 for (j = 0; j < 256; ++j)
783 {
784 if (!e[j])
785 continue;
786 f = (char **) e[j];
787 for (k = 0; k < 256; ++k)
788 {
789 if (!f[k])
790 continue;
791 g = (char **)f[k];
792 for (l = 0; l < 256; ++l)
793 {
794 if (!g[l])
795 continue;
796 cli_print(cli, "%7d %d.%d.%d.%d", (int) (intptr_t) g[l], i, j, k, l);
797 ++count;
798 }
799 }
800 }
801 }
802 cli_print(cli, "%d entries in cache", count);
803 return CLI_OK;
804 }
805
806
807 // Find session by username, 0 for not found
808 // walled garden users aren't authenticated, so the username is
809 // reasonably useless. Ignore them to avoid incorrect actions
810 //
811 // This is VERY inefficent. Don't call it often. :)
812 //
813 sessionidt sessionbyuser(char *username)
814 {
815 int s;
816 CSTAT(sessionbyuser);
817
818 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
819 {
820 if (!session[s].opened)
821 continue;
822
823 if (session[s].walled_garden)
824 continue; // Skip walled garden users.
825
826 if (!strncmp(session[s].user, username, 128))
827 return s;
828
829 }
830 return 0; // Not found.
831 }
832
833 void send_garp(in_addr_t ip)
834 {
835 int s;
836 struct ifreq ifr;
837 uint8_t mac[6];
838
839 s = socket(PF_INET, SOCK_DGRAM, 0);
840 if (s < 0)
841 {
842 LOG(0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
843 return;
844 }
845 memset(&ifr, 0, sizeof(ifr));
846 strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
847 if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
848 {
849 LOG(0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
850 close(s);
851 return;
852 }
853 memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
854 if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
855 {
856 LOG(0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
857 close(s);
858 return;
859 }
860 close(s);
861 sendarp(ifr.ifr_ifindex, mac, ip);
862 }
863
864 static sessiont *sessiontbysessionidt(sessionidt s)
865 {
866 if (!s || s >= MAXSESSION) return NULL;
867 return &session[s];
868 }
869
870 static sessionidt sessionidtbysessiont(sessiont *s)
871 {
872 sessionidt val = s-session;
873 if (s < session || val >= MAXSESSION) return 0;
874 return val;
875 }
876
877 // actually send a control message for a specific tunnel
878 void tunnelsend(uint8_t * buf, uint16_t l, tunnelidt t)
879 {
880 struct sockaddr_in addr;
881
882 CSTAT(tunnelsend);
883
884 if (!t)
885 {
886 static int backtrace_count = 0;
887 LOG(0, 0, t, "tunnelsend called with 0 as tunnel id\n");
888 STAT(tunnel_tx_errors);
889 log_backtrace(backtrace_count, 5)
890 return;
891 }
892
893 if (!tunnel[t].ip)
894 {
895 static int backtrace_count = 0;
896 LOG(1, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
897 log_backtrace(backtrace_count, 5)
898 STAT(tunnel_tx_errors);
899 return;
900 }
901
902 memset(&addr, 0, sizeof(addr));
903 addr.sin_family = AF_INET;
904 *(uint32_t *) & addr.sin_addr = htonl(tunnel[t].ip);
905 addr.sin_port = htons(tunnel[t].port);
906
907 // sequence expected, if sequence in message
908 if (*buf & 0x08) *(uint16_t *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
909
910 // If this is a control message, deal with retries
911 if (*buf & 0x80)
912 {
913 tunnel[t].last = time_now; // control message sent
914 tunnel[t].retry = backoff(tunnel[t].try); // when to resend
915 if (tunnel[t].try > 1)
916 {
917 STAT(tunnel_retries);
918 LOG(3, 0, t, "Control message resend try %d\n", tunnel[t].try);
919 }
920 }
921
922 if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
923 {
924 LOG(0, ntohs((*(uint16_t *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
925 strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
926 STAT(tunnel_tx_errors);
927 return;
928 }
929
930 LOG_HEX(5, "Send Tunnel Data", buf, l);
931 STAT(tunnel_tx_packets);
932 INC_STAT(tunnel_tx_bytes, l);
933 }
934
935 //
936 // Tiny helper function to write data to
937 // the 'tun' device.
938 //
939 int tun_write(uint8_t * data, int size)
940 {
941 return write(tunfd, data, size);
942 }
943
944 // process outgoing (to tunnel) IP
945 //
946 static void processipout(uint8_t * buf, int len)
947 {
948 sessionidt s;
949 sessiont *sp;
950 tunnelidt t;
951 in_addr_t ip;
952
953 char *data = buf; // Keep a copy of the originals.
954 int size = len;
955
956 uint8_t b[MAXETHER + 20];
957
958 CSTAT(processipout);
959
960 if (len < MIN_IP_SIZE)
961 {
962 LOG(1, 0, 0, "Short IP, %d bytes\n", len);
963 STAT(tun_rx_errors);
964 return;
965 }
966 if (len >= MAXETHER)
967 {
968 LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
969 STAT(tun_rx_errors);
970 return;
971 }
972
973 // Skip the tun header
974 buf += 4;
975 len -= 4;
976
977 // Got an IP header now
978 if (*(uint8_t *)(buf) >> 4 != 4)
979 {
980 LOG(1, 0, 0, "IP: Don't understand anything except IPv4\n");
981 return;
982 }
983
984 ip = *(uint32_t *)(buf + 16);
985 if (!(s = sessionbyip(ip)))
986 {
987 // Is this a packet for a session that doesn't exist?
988 static int rate = 0; // Number of ICMP packets we've sent this second.
989 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
990
991 if (last != time_now)
992 {
993 last = time_now;
994 rate = 0;
995 }
996
997 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
998 {
999 LOG(4, 0, 0, "IP: Sending ICMP host unreachable to %s\n", fmtaddr(*(in_addr_t *)(buf + 12), 0));
1000 host_unreachable(*(in_addr_t *)(buf + 12), *(uint16_t *)(buf + 4), ip, buf, (len < 64) ? 64 : len);
1001 }
1002 return;
1003 }
1004 t = session[s].tunnel;
1005 sp = &session[s];
1006
1007 // DoS prevention: enforce a maximum number of packets per 0.1s for a session
1008 if (config->max_packets > 0)
1009 {
1010 if (sess_local[s].last_packet_out == TIME)
1011 {
1012 int max = config->max_packets;
1013
1014 // All packets for throttled sessions are handled by the
1015 // master, so further limit by using the throttle rate.
1016 // A bit of a kludge, since throttle rate is in kbps,
1017 // but should still be generous given our average DSL
1018 // packet size is 200 bytes: a limit of 28kbps equates
1019 // to around 180 packets per second.
1020 if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
1021 max = sp->throttle_out;
1022
1023 if (++sess_local[s].packets_out > max)
1024 {
1025 sess_local[s].packets_dropped++;
1026 return;
1027 }
1028 }
1029 else
1030 {
1031 if (sess_local[s].packets_dropped)
1032 {
1033 INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
1034 LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
1035 sess_local[s].packets_dropped, sess_local[s].packets_out,
1036 fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
1037 sp->user);
1038 }
1039
1040 sess_local[s].last_packet_out = TIME;
1041 sess_local[s].packets_out = 1;
1042 sess_local[s].packets_dropped = 0;
1043 }
1044 }
1045
1046 // run access-list if any
1047 if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
1048 return;
1049
1050 if (sp->tbf_out)
1051 {
1052 // Are we throttling this session?
1053 if (config->cluster_iam_master)
1054 tbf_queue_packet(sp->tbf_out, data, size);
1055 else
1056 master_throttle_packet(sp->tbf_out, data, size);
1057 return;
1058 }
1059 else if (sp->walled_garden && !config->cluster_iam_master)
1060 {
1061 // We are walled-gardening this
1062 master_garden_packet(s, data, size);
1063 return;
1064 }
1065
1066 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1067
1068 // Add on L2TP header
1069 {
1070 uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
1071 if (!p) return;
1072 tunnelsend(b, len + (p-b), t); // send it...
1073 }
1074
1075 // Snooping this session, send it to intercept box
1076 if (sp->snoop_ip && sp->snoop_port)
1077 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1078
1079 sp->cout += len; // byte count
1080 sp->total_cout += len; // byte count
1081 sp->pout++;
1082 udp_tx += len;
1083 sess_local[s].cout += len; // To send to master..
1084 }
1085
1086 // process outgoing (to tunnel) IPv6
1087 //
1088 static void processipv6out(uint8_t * buf, int len)
1089 {
1090 sessionidt s;
1091 sessiont *sp;
1092 tunnelidt t;
1093 in_addr_t ip;
1094 struct in6_addr ip6;
1095
1096 char *data = buf; // Keep a copy of the originals.
1097 int size = len;
1098
1099 uint8_t b[MAXETHER + 20];
1100
1101 CSTAT(processipv6out);
1102
1103 if (len < MIN_IP_SIZE)
1104 {
1105 LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
1106 STAT(tunnel_tx_errors);
1107 return;
1108 }
1109 if (len >= MAXETHER)
1110 {
1111 LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
1112 STAT(tunnel_tx_errors);
1113 return;
1114 }
1115
1116 // Skip the tun header
1117 buf += 4;
1118 len -= 4;
1119
1120 // Got an IP header now
1121 if (*(uint8_t *)(buf) >> 4 != 6)
1122 {
1123 LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
1124 return;
1125 }
1126
1127 ip6 = *(struct in6_addr *)(buf+24);
1128 s = sessionbyipv6(ip6);
1129
1130 if (s == 0)
1131 {
1132 ip = *(uint32_t *)(buf + 32);
1133 s = sessionbyip(ip);
1134 }
1135
1136 if (s == 0)
1137 {
1138 // Is this a packet for a session that doesn't exist?
1139 static int rate = 0; // Number of ICMP packets we've sent this second.
1140 static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
1141
1142 if (last != time_now)
1143 {
1144 last = time_now;
1145 rate = 0;
1146 }
1147
1148 if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
1149 {
1150 // FIXME: Should send icmp6 host unreachable
1151 }
1152 return;
1153 }
1154 t = session[s].tunnel;
1155 sp = &session[s];
1156
1157 // FIXME: add DoS prevention/filters?
1158
1159 if (sp->tbf_out)
1160 {
1161 // Are we throttling this session?
1162 if (config->cluster_iam_master)
1163 tbf_queue_packet(sp->tbf_out, data, size);
1164 else
1165 master_throttle_packet(sp->tbf_out, data, size);
1166 return;
1167 }
1168 else if (sp->walled_garden && !config->cluster_iam_master)
1169 {
1170 // We are walled-gardening this
1171 master_garden_packet(s, data, size);
1172 return;
1173 }
1174
1175 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1176
1177 // Add on L2TP header
1178 {
1179 uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIPV6);
1180 if (!p) return;
1181 tunnelsend(b, len + (p-b), t); // send it...
1182 }
1183
1184 // Snooping this session, send it to intercept box
1185 if (sp->snoop_ip && sp->snoop_port)
1186 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1187
1188 sp->cout += len; // byte count
1189 sp->total_cout += len; // byte count
1190 sp->pout++;
1191 udp_tx += len;
1192 sess_local[s].cout += len; // To send to master..
1193 }
1194
1195 //
1196 // Helper routine for the TBF filters.
1197 // Used to send queued data in to the user!
1198 //
1199 static void send_ipout(sessionidt s, uint8_t *buf, int len)
1200 {
1201 sessiont *sp;
1202 tunnelidt t;
1203 in_addr_t ip;
1204
1205 uint8_t b[MAXETHER + 20];
1206
1207 if (len < 0 || len > MAXETHER)
1208 {
1209 LOG(1, 0, 0, "Odd size IP packet: %d bytes\n", len);
1210 return;
1211 }
1212
1213 // Skip the tun header
1214 buf += 4;
1215 len -= 4;
1216
1217 ip = *(in_addr_t *)(buf + 16);
1218
1219 if (!session[s].ip)
1220 return;
1221
1222 t = session[s].tunnel;
1223 sp = &session[s];
1224
1225 LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
1226
1227 // Add on L2TP header
1228 {
1229 uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
1230 if (!p) return;
1231 tunnelsend(b, len + (p-b), t); // send it...
1232 }
1233
1234 // Snooping this session.
1235 if (sp->snoop_ip && sp->snoop_port)
1236 snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
1237
1238 sp->cout += len; // byte count
1239 sp->total_cout += len; // byte count
1240 sp->pout++;
1241 udp_tx += len;
1242 sess_local[s].cout += len; // To send to master..
1243 }
1244
1245 // add an AVP (16 bit)
1246 static void control16(controlt * c, uint16_t avp, uint16_t val, uint8_t m)
1247 {
1248 uint16_t l = (m ? 0x8008 : 0x0008);
1249 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1250 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1251 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1252 *(uint16_t *) (c->buf + c->length + 6) = htons(val);
1253 c->length += 8;
1254 }
1255
1256 // add an AVP (32 bit)
1257 static void control32(controlt * c, uint16_t avp, uint32_t val, uint8_t m)
1258 {
1259 uint16_t l = (m ? 0x800A : 0x000A);
1260 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1261 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1262 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1263 *(uint32_t *) (c->buf + c->length + 6) = htonl(val);
1264 c->length += 10;
1265 }
1266
1267 // add an AVP (string)
1268 static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
1269 {
1270 uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
1271 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1272 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1273 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1274 memcpy(c->buf + c->length + 6, val, strlen(val));
1275 c->length += 6 + strlen(val);
1276 }
1277
1278 // add a binary AVP
1279 static void controlb(controlt * c, uint16_t avp, char *val, unsigned int len, uint8_t m)
1280 {
1281 uint16_t l = ((m ? 0x8000 : 0) + len + 6);
1282 *(uint16_t *) (c->buf + c->length + 0) = htons(l);
1283 *(uint16_t *) (c->buf + c->length + 2) = htons(0);
1284 *(uint16_t *) (c->buf + c->length + 4) = htons(avp);
1285 memcpy(c->buf + c->length + 6, val, len);
1286 c->length += 6 + len;
1287 }
1288
1289 // new control connection
1290 static controlt *controlnew(uint16_t mtype)
1291 {
1292 controlt *c;
1293 if (!controlfree)
1294 c = malloc(sizeof(controlt));
1295 else
1296 {
1297 c = controlfree;
1298 controlfree = c->next;
1299 }
1300 assert(c);
1301 c->next = 0;
1302 *(uint16_t *) (c->buf + 0) = htons(0xC802); // flags/ver
1303 c->length = 12;
1304 control16(c, 0, mtype, 1);
1305 return c;
1306 }
1307
1308 // send zero block if nothing is waiting
1309 // (ZLB send).
1310 static void controlnull(tunnelidt t)
1311 {
1312 uint8_t buf[12];
1313 if (tunnel[t].controlc) // Messages queued; They will carry the ack.
1314 return;
1315
1316 *(uint16_t *) (buf + 0) = htons(0xC802); // flags/ver
1317 *(uint16_t *) (buf + 2) = htons(12); // length
1318 *(uint16_t *) (buf + 4) = htons(tunnel[t].far); // tunnel
1319 *(uint16_t *) (buf + 6) = htons(0); // session
1320 *(uint16_t *) (buf + 8) = htons(tunnel[t].ns); // sequence
1321 *(uint16_t *) (buf + 10) = htons(tunnel[t].nr); // sequence
1322 tunnelsend(buf, 12, t);
1323 }
1324
1325 // add a control message to a tunnel, and send if within window
1326 static void controladd(controlt * c, tunnelidt t, sessionidt s)
1327 {
1328 *(uint16_t *) (c->buf + 2) = htons(c->length); // length
1329 *(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
1330 *(uint16_t *) (c->buf + 6) = htons(s ? session[s].far : 0); // session
1331 *(uint16_t *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
1332 tunnel[t].ns++; // advance sequence
1333 // link in message in to queue
1334 if (tunnel[t].controlc)
1335 tunnel[t].controle->next = c;
1336 else
1337 tunnel[t].controls = c;
1338
1339 tunnel[t].controle = c;
1340 tunnel[t].controlc++;
1341
1342 // send now if space in window
1343 if (tunnel[t].controlc <= tunnel[t].window)
1344 {
1345 tunnel[t].try = 0; // first send
1346 tunnelsend(c->buf, c->length, t);
1347 }
1348 }
1349
1350 //
1351 // Throttle or Unthrottle a session
1352 //
1353 // Throttle the data from/to through a session to no more than
1354 // 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
1355 // user).
1356 //
1357 // If either value is -1, the current value is retained for that
1358 // direction.
1359 //
1360 void throttle_session(sessionidt s, int rate_in, int rate_out)
1361 {
1362 if (!session[s].opened)
1363 return; // No-one home.
1364
1365 if (!*session[s].user)
1366 return; // User not logged in
1367
1368 if (rate_in >= 0)
1369 {
1370 int bytes = rate_in * 1024 / 8; // kbits to bytes
1371 if (session[s].tbf_in)
1372 free_tbf(session[s].tbf_in);
1373
1374 if (rate_in > 0)
1375 session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
1376 else
1377 session[s].tbf_in = 0;
1378
1379 session[s].throttle_in = rate_in;
1380 }
1381
1382 if (rate_out >= 0)
1383 {
1384 int bytes = rate_out * 1024 / 8;
1385 if (session[s].tbf_out)
1386 free_tbf(session[s].tbf_out);
1387
1388 if (rate_out > 0)
1389 session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
1390 else
1391 session[s].tbf_out = 0;
1392
1393 session[s].throttle_out = rate_out;
1394 }
1395 }
1396
1397 // add/remove filters from session (-1 = no change)
1398 static void filter_session(sessionidt s, int filter_in, int filter_out)
1399 {
1400 if (!session[s].opened)
1401 return; // No-one home.
1402
1403 if (!*session[s].user)
1404 return; // User not logged in
1405
1406 // paranoia
1407 if (filter_in > MAXFILTER) filter_in = -1;
1408 if (filter_out > MAXFILTER) filter_out = -1;
1409 if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
1410 if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
1411
1412 if (filter_in >= 0)
1413 {
1414 if (session[s].filter_in)
1415 ip_filters[session[s].filter_in - 1].used--;
1416
1417 if (filter_in > 0)
1418 ip_filters[filter_in - 1].used++;
1419
1420 session[s].filter_in = filter_in;
1421 }
1422
1423 if (filter_out >= 0)
1424 {
1425 if (session[s].filter_out)
1426 ip_filters[session[s].filter_out - 1].used--;
1427
1428 if (filter_out > 0)
1429 ip_filters[filter_out - 1].used++;
1430
1431 session[s].filter_out = filter_out;
1432 }
1433 }
1434
1435 // start tidy shutdown of session
1436 void sessionshutdown(sessionidt s, char *reason, int result, int error)
1437 {
1438 int walled_garden = session[s].walled_garden;
1439
1440
1441 CSTAT(sessionshutdown);
1442
1443 if (!session[s].opened)
1444 {
1445 LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
1446 return; // not a live session
1447 }
1448
1449 if (!session[s].die)
1450 {
1451 struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
1452 LOG(2, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
1453 run_plugins(PLUGIN_KILL_SESSION, &data);
1454 }
1455
1456 if (session[s].ip && !walled_garden && !session[s].die)
1457 {
1458 // RADIUS Stop message
1459 uint16_t r = sess_local[s].radius;
1460 if (!r)
1461 r = radiusnew(s);
1462
1463 if (r)
1464 {
1465 // stop, if not already trying
1466 if (radius[r].state != RADIUSSTOP)
1467 radiussend(r, RADIUSSTOP);
1468 }
1469 else
1470 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
1471
1472 // Save counters to dump to accounting file
1473 if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
1474 memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
1475 }
1476
1477 if (session[s].ip)
1478 { // IP allocated, clear and unroute
1479 int r;
1480 int routed = 0;
1481 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
1482 {
1483 if ((session[s].ip & session[s].route[r].mask) ==
1484 (session[s].route[r].ip & session[s].route[r].mask))
1485 routed++;
1486
1487 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
1488 session[s].route[r].ip = 0;
1489 }
1490
1491 if (session[s].ip_pool_index == -1) // static ip
1492 {
1493 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
1494 session[s].ip = 0;
1495 }
1496 else
1497 free_ip_address(s);
1498
1499 // unroute IPv6, if setup
1500 if (session[s].flags & SF_IPV6_ROUTED)
1501 route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
1502 }
1503
1504 if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
1505 throttle_session(s, 0, 0);
1506
1507 if (result)
1508 { // Send CDN
1509 controlt *c = controlnew(14); // sending CDN
1510 if (error)
1511 {
1512 char buf[4];
1513 *(uint16_t *) buf = htons(result);
1514 *(uint16_t *) (buf+2) = htons(error);
1515 controlb(c, 1, buf, 4, 1);
1516 }
1517 else
1518 control16(c, 1, result, 1);
1519
1520 control16(c, 14, s, 1); // assigned session (our end)
1521 controladd(c, session[s].tunnel, s); // send the message
1522 }
1523
1524 if (!session[s].die)
1525 session[s].die = TIME + 150; // Clean up in 15 seconds
1526
1527 // update filter refcounts
1528 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1529 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1530
1531 cluster_send_session(s);
1532 }
1533
1534 void sendipcp(tunnelidt t, sessionidt s)
1535 {
1536 uint8_t buf[MAXCONTROL];
1537 uint16_t r = sess_local[s].radius;
1538 uint8_t *q;
1539
1540 CSTAT(sendipcp);
1541
1542 if (!r)
1543 r = radiusnew(s);
1544
1545 if (!r)
1546 {
1547 sessionshutdown(s, "No free RADIUS sessions for IPCP");
1548 return;
1549 }
1550
1551 if (radius[r].state != RADIUSIPCP)
1552 {
1553 radius[r].state = RADIUSIPCP;
1554 radius[r].try = 0;
1555 }
1556
1557 radius[r].retry = backoff(radius[r].try++);
1558 if (radius[r].try > 10)
1559 {
1560 radiusclear(r, s); // Clear radius session.
1561 sessionshutdown(s, "No reply to IPCP.", 3, 0);
1562 return;
1563 }
1564
1565 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
1566 if (!q) return;
1567
1568 *q = ConfigReq;
1569 q[1] = r << RADIUS_SHIFT; // ID, dont care, we only send one type of request
1570 *(uint16_t *) (q + 2) = htons(10);
1571 q[4] = 3;
1572 q[5] = 6;
1573 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1574 config->bind_address ? config->bind_address :
1575 my_address; // send my IP
1576
1577 tunnelsend(buf, 10 + (q - buf), t); // send it
1578 session[s].flags &= ~SF_IPCP_ACKED; // Clear flag.
1579
1580 // If we have an IPv6 prefix length configured, assume we should
1581 // try to negotiate an IPv6 session as well. Unless we've had a
1582 // (N)ACK for IPV6CP.
1583 if (config->ipv6_prefix.s6_addr[0] > 0 &&
1584 !(session[s].flags & SF_IPV6CP_ACKED) &&
1585 !(session[s].flags & SF_IPV6_NACKED))
1586 {
1587 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
1588 if (!q) return;
1589
1590 *q = ConfigReq;
1591 q[1] = r << RADIUS_SHIFT; // ID, don't care, we
1592 // only send one type
1593 // of request
1594 *(uint16_t *) (q + 2) = htons(14);
1595 q[4] = 1;
1596 q[5] = 10;
1597 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1598 *(uint32_t *) (q + 10) = 0;
1599 q[13] = 1;
1600
1601 tunnelsend(buf, 14 + (q - buf), t); // send it
1602 }
1603 }
1604
1605 static void sessionclear(sessionidt s)
1606 {
1607 memset(&session[s], 0, sizeof(session[s]));
1608 memset(&sess_local[s], 0, sizeof(sess_local[s]));
1609 memset(&cli_session_actions[s], 0, sizeof(cli_session_actions[s]));
1610
1611 session[s].tunnel = T_FREE; // Mark it as free.
1612 session[s].next = sessionfree;
1613 sessionfree = s;
1614 }
1615
1616 // kill a session now
1617 void sessionkill(sessionidt s, char *reason)
1618 {
1619
1620 CSTAT(sessionkill);
1621
1622 if (!session[s].opened) // not alive
1623 return;
1624
1625 if (session[s].next)
1626 {
1627 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1628 return;
1629 }
1630
1631 session[s].die = TIME;
1632 sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
1633 if (sess_local[s].radius)
1634 radiusclear(sess_local[s].radius, s); // cant send clean accounting data, session is killed
1635
1636 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1637 sessionclear(s);
1638 cluster_send_session(s);
1639 }
1640
1641 static void tunnelclear(tunnelidt t)
1642 {
1643 if (!t) return;
1644 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1645 tunnel[t].state = TUNNELFREE;
1646 }
1647
1648 // kill a tunnel now
1649 static void tunnelkill(tunnelidt t, char *reason)
1650 {
1651 sessionidt s;
1652 controlt *c;
1653
1654 CSTAT(tunnelkill);
1655
1656 tunnel[t].state = TUNNELDIE;
1657
1658 // free control messages
1659 while ((c = tunnel[t].controls))
1660 {
1661 controlt * n = c->next;
1662 tunnel[t].controls = n;
1663 tunnel[t].controlc--;
1664 c->next = controlfree;
1665 controlfree = c;
1666 }
1667 // kill sessions
1668 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1669 if (session[s].tunnel == t)
1670 sessionkill(s, reason);
1671
1672 // free tunnel
1673 tunnelclear(t);
1674 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1675 cli_tunnel_actions[t].action = 0;
1676 cluster_send_tunnel(t);
1677 }
1678
1679 // shut down a tunnel cleanly
1680 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1681 {
1682 sessionidt s;
1683
1684 CSTAT(tunnelshutdown);
1685
1686 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1687 {
1688 // never set up, can immediately kill
1689 tunnelkill(t, reason);
1690 return;
1691 }
1692 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1693
1694 // close session
1695 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1696 if (session[s].tunnel == t)
1697 sessionshutdown(s, reason, 3, 0);
1698
1699 tunnel[t].state = TUNNELDIE;
1700 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1701 cluster_send_tunnel(t);
1702 // TBA - should we wait for sessions to stop?
1703 if (result)
1704 {
1705 controlt *c = controlnew(4); // sending StopCCN
1706 if (error)
1707 {
1708 char buf[64];
1709 int l = 4;
1710 *(uint16_t *) buf = htons(result);
1711 *(uint16_t *) (buf+2) = htons(error);
1712 if (msg)
1713 {
1714 int m = strlen(msg);
1715 if (m + 4 > sizeof(buf))
1716 m = sizeof(buf) - 4;
1717
1718 memcpy(buf+4, msg, m);
1719 l += m;
1720 }
1721
1722 controlb(c, 1, buf, l, 1);
1723 }
1724 else
1725 control16(c, 1, result, 1);
1726
1727 control16(c, 9, t, 1); // assigned tunnel (our end)
1728 controladd(c, t, 0); // send the message
1729 }
1730 }
1731
1732 // read and process packet on tunnel (UDP)
1733 void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
1734 {
1735 char *chapresponse = NULL;
1736 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1737 uint8_t *p = buf + 2;
1738
1739
1740 CSTAT(processudp);
1741
1742 udp_rx += len;
1743 udp_rx_pkt++;
1744 LOG_HEX(5, "UDP Data", buf, len);
1745 STAT(tunnel_rx_packets);
1746 INC_STAT(tunnel_rx_bytes, len);
1747 if (len < 6)
1748 {
1749 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1750 STAT(tunnel_rx_errors);
1751 return;
1752 }
1753 if ((buf[1] & 0x0F) != 2)
1754 {
1755 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1756 STAT(tunnel_rx_errors);
1757 return;
1758 }
1759 if (*buf & 0x40)
1760 { // length
1761 l = ntohs(*(uint16_t *) p);
1762 p += 2;
1763 }
1764 t = ntohs(*(uint16_t *) p);
1765 p += 2;
1766 s = ntohs(*(uint16_t *) p);
1767 p += 2;
1768 if (s >= MAXSESSION)
1769 {
1770 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1771 STAT(tunnel_rx_errors);
1772 return;
1773 }
1774 if (t >= MAXTUNNEL)
1775 {
1776 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1777 STAT(tunnel_rx_errors);
1778 return;
1779 }
1780 if (*buf & 0x08)
1781 { // ns/nr
1782 ns = ntohs(*(uint16_t *) p);
1783 p += 2;
1784 nr = ntohs(*(uint16_t *) p);
1785 p += 2;
1786 }
1787 if (*buf & 0x02)
1788 { // offset
1789 uint16_t o = ntohs(*(uint16_t *) p);
1790 p += o + 2;
1791 }
1792 if ((p - buf) > l)
1793 {
1794 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1795 STAT(tunnel_rx_errors);
1796 return;
1797 }
1798 l -= (p - buf);
1799 if (*buf & 0x80)
1800 { // control
1801 uint16_t message = 0xFFFF; // message type
1802 uint8_t fatal = 0;
1803 uint8_t mandatory = 0;
1804 uint8_t chap = 0; // if CHAP being used
1805 uint16_t asession = 0; // assigned session
1806 uint32_t amagic = 0; // magic number
1807 uint8_t aflags = 0; // flags from last LCF
1808 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1809 int requestchap = 0; // do we request PAP instead of original CHAP request?
1810 char called[MAXTEL] = ""; // called number
1811 char calling[MAXTEL] = ""; // calling number
1812
1813 if (!config->cluster_iam_master)
1814 {
1815 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1816 return;
1817 }
1818
1819 // control messages must have bits 0x80|0x40|0x08
1820 // (type, length and sequence) set, and bits 0x02|0x01
1821 // (offset and priority) clear
1822 if ((*buf & 0xCB) != 0xC8)
1823 {
1824 LOG(1, s, t, "Bad control header %02X\n", *buf);
1825 STAT(tunnel_rx_errors);
1826 return;
1827 }
1828
1829 // check for duplicate tunnel open message
1830 if (!t && ns == 0)
1831 {
1832 int i;
1833
1834 //
1835 // Is this a duplicate of the first packet? (SCCRQ)
1836 //
1837 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1838 {
1839 if (tunnel[i].state != TUNNELOPENING ||
1840 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1841 tunnel[i].port != ntohs(addr->sin_port) )
1842 continue;
1843 t = i;
1844 LOG(3, s, t, "Duplicate SCCRQ?\n");
1845 break;
1846 }
1847 }
1848
1849 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1850 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1851
1852 // if no tunnel specified, assign one
1853 if (!t)
1854 {
1855 if (!(t = new_tunnel()))
1856 {
1857 LOG(1, 0, 0, "No more tunnels\n");
1858 STAT(tunnel_overflow);
1859 return;
1860 }
1861 tunnelclear(t);
1862 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1863 tunnel[t].port = ntohs(addr->sin_port);
1864 tunnel[t].window = 4; // default window
1865 STAT(tunnel_created);
1866 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1867 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1868 }
1869
1870 // If the 'ns' just received is not the 'nr' we're
1871 // expecting, just send an ack and drop it.
1872 //
1873 // if 'ns' is less, then we got a retransmitted packet.
1874 // if 'ns' is greater than missed a packet. Either way
1875 // we should ignore it.
1876 if (ns != tunnel[t].nr)
1877 {
1878 // is this the sequence we were expecting?
1879 STAT(tunnel_rx_errors);
1880 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
1881 t, ns, tunnel[t].nr);
1882
1883 if (l) // Is this not a ZLB?
1884 controlnull(t);
1885 return;
1886 }
1887
1888 // This is used to time out old tunnels
1889 tunnel[t].lastrec = time_now;
1890
1891 // check sequence of this message
1892 {
1893 int skip = tunnel[t].window; // track how many in-window packets are still in queue
1894 // some to clear maybe?
1895 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
1896 {
1897 controlt *c = tunnel[t].controls;
1898 tunnel[t].controls = c->next;
1899 tunnel[t].controlc--;
1900 c->next = controlfree;
1901 controlfree = c;
1902 skip--;
1903 tunnel[t].try = 0; // we have progress
1904 }
1905
1906 // receiver advance (do here so quoted correctly in any sends below)
1907 if (l) tunnel[t].nr = (ns + 1);
1908 if (skip < 0) skip = 0;
1909 if (skip < tunnel[t].controlc)
1910 {
1911 // some control packets can now be sent that were previous stuck out of window
1912 int tosend = tunnel[t].window - skip;
1913 controlt *c = tunnel[t].controls;
1914 while (c && skip)
1915 {
1916 c = c->next;
1917 skip--;
1918 }
1919 while (c && tosend)
1920 {
1921 tunnel[t].try = 0; // first send
1922 tunnelsend(c->buf, c->length, t);
1923 c = c->next;
1924 tosend--;
1925 }
1926 }
1927 if (!tunnel[t].controlc)
1928 tunnel[t].retry = 0; // caught up
1929 }
1930 if (l)
1931 { // if not a null message
1932 int result = 0;
1933 int error = 0;
1934 char *msg = 0;
1935
1936 // process AVPs
1937 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
1938 {
1939 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
1940 uint8_t *b = p;
1941 uint8_t flags = *p;
1942 uint16_t mtype;
1943 if (n > l)
1944 {
1945 LOG(1, s, t, "Invalid length in AVP\n");
1946 STAT(tunnel_rx_errors);
1947 return;
1948 }
1949 p += n; // next
1950 l -= n;
1951 if (flags & 0x3C) // reserved bits, should be clear
1952 {
1953 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
1954 fatal = flags;
1955 result = 2; // general error
1956 error = 3; // reserved field non-zero
1957 msg = 0;
1958 continue; // next
1959 }
1960 b += 2;
1961 if (*(uint16_t *) (b))
1962 {
1963 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
1964 fatal = flags;
1965 result = 2; // general error
1966 error = 6; // generic vendor-specific error
1967 msg = "unsupported vendor-specific";
1968 continue; // next
1969 }
1970 b += 2;
1971 mtype = ntohs(*(uint16_t *) (b));
1972 b += 2;
1973 n -= 6;
1974
1975 if (flags & 0x40)
1976 {
1977 uint16_t orig_len;
1978
1979 // handle hidden AVPs
1980 if (!*config->l2tpsecret)
1981 {
1982 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
1983 fatal = flags;
1984 result = 2; // general error
1985 error = 6; // generic vendor-specific error
1986 msg = "secret not specified";
1987 continue;
1988 }
1989 if (!session[s].random_vector_length)
1990 {
1991 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
1992 fatal = flags;
1993 result = 2; // general error
1994 error = 6; // generic
1995 msg = "no random vector";
1996 continue;
1997 }
1998 if (n < 8)
1999 {
2000 LOG(2, s, t, "Short hidden AVP.\n");
2001 fatal = flags;
2002 result = 2; // general error
2003 error = 2; // length is wrong
2004 msg = 0;
2005 continue;
2006 }
2007
2008 LOG(4, s, t, "Hidden AVP\n");
2009
2010 // Unhide the AVP
2011 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
2012
2013 orig_len = ntohs(*(uint16_t *) b);
2014 if (orig_len > n + 2)
2015 {
2016 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
2017 orig_len, n);
2018
2019 fatal = flags;
2020 result = 2; // general error
2021 error = 2; // length is wrong
2022 msg = 0;
2023 continue;
2024 }
2025
2026 b += 2;
2027 n = orig_len;
2028 }
2029
2030 LOG(4, s, t, " AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
2031 switch (mtype)
2032 {
2033 case 0: // message type
2034 message = ntohs(*(uint16_t *) b);
2035 mandatory = flags & 0x80;
2036 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_message_type(message));
2037 break;
2038 case 1: // result code
2039 {
2040 uint16_t rescode = ntohs(*(uint16_t *) b);
2041 const char* resdesc = "(unknown)";
2042 if (message == 4)
2043 { /* StopCCN */
2044 resdesc = stopccn_result_code(rescode);
2045 }
2046 else if (message == 14)
2047 { /* CDN */
2048 resdesc = cdn_result_code(rescode);
2049 }
2050
2051 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2052 if (n >= 4)
2053 {
2054 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2055 LOG(4, s, t, " Error Code %d: %s\n", errcode, error_code(errcode));
2056 }
2057 if (n > 4)
2058 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2059
2060 break;
2061 }
2062 break;
2063 case 2: // protocol version
2064 {
2065 version = ntohs(*(uint16_t *) (b));
2066 LOG(4, s, t, " Protocol version = %d\n", version);
2067 if (version && version != 0x0100)
2068 { // allow 0.0 and 1.0
2069 LOG(1, s, t, " Bad protocol version %04X\n", version);
2070 fatal = flags;
2071 result = 5; // unspported protocol version
2072 error = 0x0100; // supported version
2073 msg = 0;
2074 continue; // next
2075 }
2076 }
2077 break;
2078 case 3: // framing capabilities
2079 // LOG(4, s, t, "Framing capabilities\n");
2080 break;
2081 case 4: // bearer capabilities
2082 // LOG(4, s, t, "Bearer capabilities\n");
2083 break;
2084 case 5: // tie breaker
2085 // We never open tunnels, so we don't care about tie breakers
2086 // LOG(4, s, t, "Tie breaker\n");
2087 continue;
2088 case 6: // firmware revision
2089 // LOG(4, s, t, "Firmware revision\n");
2090 break;
2091 case 7: // host name
2092 memset(tunnel[t].hostname, 0, sizeof(tunnel[t].hostname));
2093 memcpy(tunnel[t].hostname, b, (n < sizeof(tunnel[t].hostname)) ? n : sizeof(tunnel[t].hostname) - 1);
2094 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2095 // TBA - to send to RADIUS
2096 break;
2097 case 8: // vendor name
2098 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2099 memcpy(tunnel[t].vendor, b, (n < sizeof(tunnel[t].vendor)) ? n : sizeof(tunnel[t].vendor) - 1);
2100 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2101 break;
2102 case 9: // assigned tunnel
2103 tunnel[t].far = ntohs(*(uint16_t *) (b));
2104 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2105 break;
2106 case 10: // rx window
2107 tunnel[t].window = ntohs(*(uint16_t *) (b));
2108 if (!tunnel[t].window)
2109 tunnel[t].window = 1; // window of 0 is silly
2110 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2111 break;
2112 case 11: // Challenge
2113 {
2114 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2115 build_chap_response(b, 2, n, &chapresponse);
2116 }
2117 break;
2118 case 13: // Response
2119 // Why did they send a response? We never challenge.
2120 LOG(2, s, t, " received unexpected challenge response\n");
2121 break;
2122
2123 case 14: // assigned session
2124 asession = session[s].far = ntohs(*(uint16_t *) (b));
2125 LOG(4, s, t, " assigned session = %d\n", asession);
2126 break;
2127 case 15: // call serial number
2128 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2129 break;
2130 case 18: // bearer type
2131 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2132 // TBA - for RADIUS
2133 break;
2134 case 19: // framing type
2135 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2136 // TBA
2137 break;
2138 case 21: // called number
2139 memset(called, 0, sizeof(called));
2140 memcpy(called, b, (n < sizeof(called)) ? n : sizeof(called) - 1);
2141 LOG(4, s, t, " Called <%s>\n", called);
2142 break;
2143 case 22: // calling number
2144 memset(calling, 0, sizeof(calling));
2145 memcpy(calling, b, (n < sizeof(calling)) ? n : sizeof(calling) - 1);
2146 LOG(4, s, t, " Calling <%s>\n", calling);
2147 break;
2148 case 23: // subtype
2149 break;
2150 case 24: // tx connect speed
2151 if (n == 4)
2152 {
2153 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2154 }
2155 else
2156 {
2157 // AS5300s send connect speed as a string
2158 char tmp[30];
2159 memset(tmp, 0, sizeof(tmp));
2160 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2161 session[s].tx_connect_speed = atol(tmp);
2162 }
2163 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2164 break;
2165 case 38: // rx connect speed
2166 if (n == 4)
2167 {
2168 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2169 }
2170 else
2171 {
2172 // AS5300s send connect speed as a string
2173 char tmp[30];
2174 memset(tmp, 0, sizeof(tmp));
2175 memcpy(tmp, b, (n < sizeof(tmp)) ? n : sizeof(tmp) - 1);
2176 session[s].rx_connect_speed = atol(tmp);
2177 }
2178 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2179 break;
2180 case 25: // Physical Channel ID
2181 {
2182 uint32_t tmp = ntohl(*(uint32_t *) b);
2183 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2184 break;
2185 }
2186 case 29: // Proxy Authentication Type
2187 {
2188 uint16_t atype = ntohs(*(uint16_t *)b);
2189 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, auth_type(atype));
2190 requestchap = (atype == 2);
2191 break;
2192 }
2193 case 30: // Proxy Authentication Name
2194 {
2195 char authname[64];
2196 memset(authname, 0, sizeof(authname));
2197 memcpy(authname, b, (n < sizeof(authname)) ? n : sizeof(authname) - 1);
2198 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2199 authname);
2200 break;
2201 }
2202 case 31: // Proxy Authentication Challenge
2203 {
2204 LOG(4, s, t, " Proxy Auth Challenge\n");
2205 if (sess_local[s].radius)
2206 memcpy(radius[sess_local[s].radius].auth, b, 16);
2207 break;
2208 }
2209 case 32: // Proxy Authentication ID
2210 {
2211 uint16_t authid = ntohs(*(uint16_t *)(b));
2212 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2213 if (sess_local[s].radius)
2214 radius[sess_local[s].radius].id = authid;
2215 break;
2216 }
2217 case 33: // Proxy Authentication Response
2218 LOG(4, s, t, " Proxy Auth Response\n");
2219 break;
2220 case 27: // last sent lcp
2221 { // find magic number
2222 uint8_t *p = b, *e = p + n;
2223 while (p + 1 < e && p[1] && p + p[1] <= e)
2224 {
2225 if (*p == 5 && p[1] == 6) // Magic-Number
2226 amagic = ntohl(*(uint32_t *) (p + 2));
2227 else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol
2228 chap = 1;
2229 else if (*p == 7) // Protocol-Field-Compression
2230 aflags |= SESSIONPFC;
2231 else if (*p == 8) // Address-and-Control-Field-Compression
2232 aflags |= SESSIONACFC;
2233 p += p[1];
2234 }
2235 }
2236 break;
2237 case 28: // last recv lcp confreq
2238 break;
2239 case 26: // Initial Received LCP CONFREQ
2240 break;
2241 case 39: // seq required - we control it as an LNS anyway...
2242 break;
2243 case 36: // Random Vector
2244 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2245 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2246 memcpy(session[s].random_vector, b, n);
2247 session[s].random_vector_length = n;
2248 break;
2249 default:
2250 {
2251 static char e[] = "unknown AVP 0xXXXX";
2252 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2253 fatal = flags;
2254 result = 2; // general error
2255 error = 8; // unknown mandatory AVP
2256 sprintf((msg = e) + 14, "%04x", mtype);
2257 continue; // next
2258 }
2259 }
2260 }
2261 // process message
2262 if (fatal & 0x80)
2263 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2264 else
2265 switch (message)
2266 {
2267 case 1: // SCCRQ - Start Control Connection Request
2268 {
2269 controlt *c = controlnew(2); // sending SCCRP
2270 control16(c, 2, version, 1); // protocol version
2271 control32(c, 3, 3, 1); // framing
2272 controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
2273 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2274 control16(c, 9, t, 1); // assigned tunnel
2275 controladd(c, t, s); // send the resply
2276 }
2277 tunnel[t].state = TUNNELOPENING;
2278 break;
2279 case 2: // SCCRP
2280 tunnel[t].state = TUNNELOPEN;
2281 break;
2282 case 3: // SCCN
2283 tunnel[t].state = TUNNELOPEN;
2284 controlnull(t); // ack
2285 break;
2286 case 4: // StopCCN
2287 controlnull(t); // ack
2288 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2289 break;
2290 case 6: // HELLO
2291 controlnull(t); // simply ACK
2292 break;
2293 case 7: // OCRQ
2294 // TBA
2295 break;
2296 case 8: // OCRO
2297 // TBA
2298 break;
2299 case 9: // OCCN
2300 // TBA
2301 break;
2302 case 10: // ICRQ
2303 if (!sessionfree)
2304 {
2305 STAT(session_overflow);
2306 LOG(1, 0, t, "No free sessions\n");
2307 return;
2308 }
2309 else
2310 {
2311 uint16_t r;
2312 controlt *c;
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 LOG(1, s, t, "No free RADIUS sessions for ICRQ\n");
2325 sessionclear(s);
2326 return;
2327 }
2328
2329 c = controlnew(11); // sending ICRP
2330 session[s].opened = time_now;
2331 session[s].tunnel = t;
2332 session[s].far = asession;
2333 session[s].last_packet = time_now;
2334 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2335 control16(c, 14, s, 1); // assigned session
2336 controladd(c, t, s); // send the reply
2337
2338 strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
2339 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2340 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2341 STAT(session_created);
2342 }
2343 break;
2344 case 11: // ICRP
2345 // TBA
2346 break;
2347 case 12: // ICCN
2348 if (amagic == 0) amagic = time_now;
2349 session[s].magic = amagic; // set magic number
2350 session[s].l2tp_flags = aflags; // set flags received
2351 LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
2352 controlnull(t); // ack
2353 // In CHAP state, request PAP instead
2354 if (requestchap)
2355 initlcp(t, s);
2356 break;
2357 case 14: // CDN
2358 controlnull(t); // ack
2359 sessionshutdown(s, "Closed (Received CDN).", 0, 0);
2360 break;
2361 case 0xFFFF:
2362 LOG(1, s, t, "Missing message type\n");
2363 break;
2364 default:
2365 STAT(tunnel_rx_errors);
2366 if (mandatory)
2367 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2368 else
2369 LOG(1, s, t, "Unknown message type %d\n", message);
2370 break;
2371 }
2372 if (chapresponse) free(chapresponse);
2373 cluster_send_tunnel(t);
2374 }
2375 else
2376 {
2377 LOG(4, s, t, " Got a ZLB ack\n");
2378 }
2379 }
2380 else
2381 { // data
2382 uint16_t prot;
2383
2384 LOG_HEX(5, "Receive Tunnel Data", p, l);
2385 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2386 { // HDLC address header, discard
2387 p += 2;
2388 l -= 2;
2389 }
2390 if (l < 2)
2391 {
2392 LOG(1, s, t, "Short ppp length %d\n", l);
2393 STAT(tunnel_rx_errors);
2394 return;
2395 }
2396 if (*p & 1)
2397 {
2398 prot = *p++;
2399 l--;
2400 }
2401 else
2402 {
2403 prot = ntohs(*(uint16_t *) p);
2404 p += 2;
2405 l -= 2;
2406 }
2407
2408 if (s && !session[s].opened) // Is something wrong??
2409 {
2410 if (!config->cluster_iam_master)
2411 {
2412 // Pass it off to the master to deal with..
2413 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2414 return;
2415 }
2416
2417
2418 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2419 STAT(tunnel_rx_errors);
2420 return;
2421 }
2422
2423 if (prot == PPPPAP)
2424 {
2425 session[s].last_packet = time_now;
2426 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2427 processpap(t, s, p, l);
2428 }
2429 else if (prot == PPPCHAP)
2430 {
2431 session[s].last_packet = time_now;
2432 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2433 processchap(t, s, p, l);
2434 }
2435 else if (prot == PPPLCP)
2436 {
2437 session[s].last_packet = time_now;
2438 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2439 processlcp(t, s, p, l);
2440 }
2441 else if (prot == PPPIPCP)
2442 {
2443 session[s].last_packet = time_now;
2444 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2445 processipcp(t, s, p, l);
2446 }
2447 else if (prot == PPPIPV6CP)
2448 {
2449 if (config->ipv6_prefix.s6_addr[0] > 0)
2450 {
2451 session[s].last_packet = time_now;
2452 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2453 processipv6cp(t, s, p, l);
2454 }
2455 else
2456 {
2457 LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n");
2458 }
2459 }
2460 else if (prot == PPPCCP)
2461 {
2462 session[s].last_packet = time_now;
2463 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2464 processccp(t, s, p, l);
2465 }
2466 else if (prot == PPPIP)
2467 {
2468 if (session[s].die)
2469 {
2470 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2471 return; // closing session, PPP not processed
2472 }
2473
2474 session[s].last_packet = time_now;
2475 if (session[s].walled_garden && !config->cluster_iam_master)
2476 {
2477 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2478 return;
2479 }
2480
2481 processipin(t, s, p, l);
2482 }
2483 else if (prot == PPPIPV6)
2484 {
2485 if (!config->ipv6_prefix.s6_addr[0] > 0)
2486 {
2487 LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
2488 return;
2489 }
2490 if (session[s].die)
2491 {
2492 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2493 return; // closing session, PPP not processed
2494 }
2495
2496 session[s].last_packet = time_now;
2497 if (session[s].walled_garden && !config->cluster_iam_master)
2498 {
2499 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2500 return;
2501 }
2502
2503 processipv6in(t, s, p, l);
2504 }
2505 else
2506 {
2507 STAT(tunnel_rx_errors);
2508 LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
2509 }
2510 }
2511 }
2512
2513 // read and process packet on tun
2514 static void processtun(uint8_t * buf, int len)
2515 {
2516 LOG_HEX(5, "Receive TUN Data", buf, len);
2517 STAT(tun_rx_packets);
2518 INC_STAT(tun_rx_bytes, len);
2519
2520 CSTAT(processtun);
2521
2522 eth_rx_pkt++;
2523 eth_rx += len;
2524 if (len < 22)
2525 {
2526 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2527 STAT(tun_rx_errors);
2528 return;
2529 }
2530
2531 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2532 processipout(buf, len);
2533 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2534 && config->ipv6_prefix.s6_addr[0] > 0)
2535 processipv6out(buf, len);
2536
2537 // Else discard.
2538 }
2539
2540 //
2541 // Maximum number of actions to complete.
2542 // This is to avoid sending out too many packets
2543 // at once.
2544 #define MAX_ACTIONS 500
2545
2546 static int regular_cleanups(void)
2547 {
2548 static sessionidt s = 0; // Next session to check for actions on.
2549 tunnelidt t;
2550 int count=0,i;
2551 uint16_t r;
2552 static clockt next_acct = 0;
2553 static clockt next_shut_acct = 0;
2554 int a;
2555
2556 LOG(3, 0, 0, "Begin regular cleanup\n");
2557
2558 for (r = 1; r < MAXRADIUS; r++)
2559 {
2560 if (!radius[r].state)
2561 continue;
2562 if (radius[r].retry)
2563 {
2564 if (radius[r].retry <= TIME)
2565 radiusretry(r);
2566 } else
2567 radius[r].retry = backoff(radius[r].try+1); // Is this really needed? --mo
2568 }
2569 for (t = 1; t <= config->cluster_highest_tunnelid; t++)
2570 {
2571 // check for expired tunnels
2572 if (tunnel[t].die && tunnel[t].die <= TIME)
2573 {
2574 STAT(tunnel_timeout);
2575 tunnelkill(t, "Expired");
2576 continue;
2577 }
2578 // check for message resend
2579 if (tunnel[t].retry && tunnel[t].controlc)
2580 {
2581 // resend pending messages as timeout on reply
2582 if (tunnel[t].retry <= TIME)
2583 {
2584 controlt *c = tunnel[t].controls;
2585 uint8_t w = tunnel[t].window;
2586 tunnel[t].try++; // another try
2587 if (tunnel[t].try > 5)
2588 tunnelkill(t, "Timeout on control message"); // game over
2589 else
2590 while (c && w--)
2591 {
2592 tunnelsend(c->buf, c->length, t);
2593 c = c->next;
2594 }
2595 }
2596 }
2597 // Send hello
2598 if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < TIME + 600)
2599 {
2600 controlt *c = controlnew(6); // sending HELLO
2601 controladd(c, t, 0); // send the message
2602 LOG(3, 0, t, "Sending HELLO message\n");
2603 }
2604
2605 // Check for tunnel changes requested from the CLI
2606 if ((a = cli_tunnel_actions[t].action))
2607 {
2608 cli_tunnel_actions[t].action = 0;
2609 if (a & CLI_TUN_KILL)
2610 {
2611 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2612 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2613 }
2614 }
2615
2616 }
2617
2618 count = 0;
2619 for (i = 1; i <= config->cluster_highest_sessionid; i++)
2620 {
2621 s++;
2622 if (s > config->cluster_highest_sessionid)
2623 s = 1;
2624
2625 if (!session[s].opened) // Session isn't in use
2626 continue;
2627
2628 // check for expired sessions
2629 if (session[s].die)
2630 {
2631 if (session[s].die <= TIME)
2632 {
2633 sessionkill(s, "Expired");
2634 if (++count >= MAX_ACTIONS) break;
2635 }
2636 continue;
2637 }
2638
2639 if (session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
2640 {
2641 // IPCP has not completed yet. Resend
2642 LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
2643 sendipcp(session[s].tunnel, s);
2644 }
2645
2646 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2647 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2648 {
2649 sessionshutdown(s, "No response to LCP ECHO requests.", 3, 0);
2650 STAT(session_timeout);
2651 if (++count >= MAX_ACTIONS) break;
2652 continue;
2653 }
2654
2655 // No data in ECHO_TIMEOUT seconds, send LCP ECHO
2656 if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
2657 {
2658 uint8_t b[MAXCONTROL] = {0};
2659
2660 uint8_t *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
2661 if (!q) continue;
2662
2663 *q = EchoReq;
2664 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2665 *(uint16_t *)(q + 2) = htons(8); // Length
2666 *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
2667
2668 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2669 (int)(time_now - session[s].last_packet));
2670 tunnelsend(b, 24, session[s].tunnel); // send it
2671 if (++count >= MAX_ACTIONS) break;
2672 }
2673
2674 // Check for actions requested from the CLI
2675 if ((a = cli_session_actions[s].action))
2676 {
2677 int send = 0;
2678
2679 cli_session_actions[s].action = 0;
2680 if (a & CLI_SESS_KILL)
2681 {
2682 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2683 sessionshutdown(s, "Requested by administrator.", 3, 0);
2684 a = 0; // dead, no need to check for other actions
2685 }
2686
2687 if (a & CLI_SESS_NOSNOOP)
2688 {
2689 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2690 session[s].snoop_ip = 0;
2691 session[s].snoop_port = 0;
2692 send++;
2693 }
2694 else if (a & CLI_SESS_SNOOP)
2695 {
2696 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2697 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2698 cli_session_actions[s].snoop_port);
2699
2700 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2701 session[s].snoop_port = cli_session_actions[s].snoop_port;
2702 send++;
2703 }
2704
2705 if (a & CLI_SESS_NOTHROTTLE)
2706 {
2707 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2708 throttle_session(s, 0, 0);
2709 send++;
2710 }
2711 else if (a & CLI_SESS_THROTTLE)
2712 {
2713 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2714 cli_session_actions[s].throttle_in,
2715 cli_session_actions[s].throttle_out);
2716
2717 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
2718 send++;
2719 }
2720
2721 if (a & CLI_SESS_NOFILTER)
2722 {
2723 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
2724 filter_session(s, 0, 0);
2725 send++;
2726 }
2727 else if (a & CLI_SESS_FILTER)
2728 {
2729 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
2730 cli_session_actions[s].filter_in,
2731 cli_session_actions[s].filter_out);
2732
2733 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
2734 send++;
2735 }
2736
2737 if (send)
2738 cluster_send_session(s);
2739
2740 if (++count >= MAX_ACTIONS) break;
2741 }
2742
2743 // RADIUS interim accounting
2744 if (config->radius_accounting && config->radius_interim > 0
2745 && session[s].ip && !session[s].walled_garden
2746 && !sess_local[s].radius // RADIUS already in progress
2747 && time_now - sess_local[s].last_interim >= config->radius_interim)
2748 {
2749 if (!(r = radiusnew(s)))
2750 {
2751 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Interim message\n");
2752 STAT(radius_overflow);
2753 continue;
2754 }
2755
2756 LOG(3, s, session[s].tunnel, "Sending RADIUS Interim for %s (%u)\n",
2757 session[s].user, session[s].unique_id);
2758
2759 radiussend(r, RADIUSINTERIM);
2760 sess_local[s].last_interim = time_now;
2761
2762 if (++count >= MAX_ACTIONS)
2763 break;
2764 }
2765 }
2766
2767 if (*config->accounting_dir)
2768 {
2769 if (next_acct <= TIME)
2770 {
2771 // Dump accounting data
2772 next_acct = TIME + ACCT_TIME;
2773 next_shut_acct = TIME + ACCT_SHUT_TIME;
2774 dump_acct_info(1);
2775 }
2776 else if (next_shut_acct <= TIME)
2777 {
2778 // Dump accounting data for shutdown sessions
2779 next_shut_acct = TIME + ACCT_SHUT_TIME;
2780 if (shut_acct_n)
2781 dump_acct_info(0);
2782 }
2783 }
2784
2785 if (count >= MAX_ACTIONS)
2786 return 1; // Didn't finish!
2787
2788 LOG(3, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
2789 return 0;
2790 }
2791
2792
2793 //
2794 // Are we in the middle of a tunnel update, or radius
2795 // requests??
2796 //
2797 static int still_busy(void)
2798 {
2799 int i;
2800 static clockt last_talked = 0;
2801 static clockt start_busy_wait = 0;
2802 if (start_busy_wait == 0)
2803 start_busy_wait = TIME;
2804
2805 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
2806 {
2807 if (!tunnel[i].controlc)
2808 continue;
2809
2810 if (last_talked != TIME)
2811 {
2812 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
2813 last_talked = TIME;
2814 }
2815 return 1;
2816 }
2817
2818 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
2819 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
2820 {
2821 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
2822 return 0;
2823 }
2824
2825 for (i = 1; i < MAXRADIUS; i++)
2826 {
2827 if (radius[i].state == RADIUSNULL)
2828 continue;
2829 if (radius[i].state == RADIUSWAIT)
2830 continue;
2831
2832 if (last_talked != TIME)
2833 {
2834 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
2835 last_talked = TIME;
2836 }
2837 return 1;
2838 }
2839
2840 return 0;
2841 }
2842
2843 static fd_set readset;
2844 static int readset_n = 0;
2845
2846 // main loop - gets packets on tun or udp and processes them
2847 static void mainloop(void)
2848 {
2849 int i;
2850 uint8_t buf[65536];
2851 struct timeval to;
2852 clockt next_cluster_ping = 0; // send initial ping immediately
2853 time_t next_clean = time_now + config->cleanup_interval;
2854
2855 LOG(4, 0, 0, "Beginning of main loop. udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
2856 udpfd, tunfd, cluster_sockfd, controlfd);
2857
2858 FD_ZERO(&readset);
2859 FD_SET(udpfd, &readset);
2860 FD_SET(tunfd, &readset);
2861 FD_SET(controlfd, &readset);
2862 FD_SET(clifd, &readset);
2863 if (cluster_sockfd) FD_SET(cluster_sockfd, &readset);
2864 readset_n = udpfd;
2865 if (tunfd > readset_n) readset_n = tunfd;
2866 if (controlfd > readset_n) readset_n = controlfd;
2867 if (clifd > readset_n) readset_n = clifd;
2868 if (cluster_sockfd > readset_n) readset_n = cluster_sockfd;
2869
2870 while (!main_quit || still_busy())
2871 {
2872 fd_set r;
2873 int n = readset_n;
2874 #ifdef BGP
2875 fd_set w;
2876 int bgp_set[BGP_NUM_PEERS];
2877 #endif /* BGP */
2878
2879 if (config->reload_config)
2880 {
2881 // Update the config state based on config settings
2882 update_config();
2883 }
2884
2885 memcpy(&r, &readset, sizeof(fd_set));
2886 to.tv_sec = 0;
2887 to.tv_usec = 100000; // 1/10th of a second.
2888
2889 #ifdef BGP
2890 FD_ZERO(&w);
2891 for (i = 0; i < BGP_NUM_PEERS; i++)
2892 {
2893 bgp_set[i] = bgp_select_state(&bgp_peers[i]);
2894 if (bgp_set[i] & 1)
2895 {
2896 FD_SET(bgp_peers[i].sock, &r);
2897 if (bgp_peers[i].sock > n)
2898 n = bgp_peers[i].sock;
2899 }
2900
2901 if (bgp_set[i] & 2)
2902 {
2903 FD_SET(bgp_peers[i].sock, &w);
2904 if (bgp_peers[i].sock > n)
2905 n = bgp_peers[i].sock;
2906 }
2907 }
2908
2909 n = select(n + 1, &r, &w, 0, &to);
2910 #else /* BGP */
2911 n = select(n + 1, &r, 0, 0, &to);
2912 #endif /* BGP */
2913
2914 STAT(select_called);
2915
2916 TIME = now();
2917 if (n < 0)
2918 {
2919 if (errno == EINTR ||
2920 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
2921 continue;
2922
2923 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
2924 main_quit++;
2925 break;
2926 }
2927 else if (n)
2928 {
2929 struct sockaddr_in addr;
2930 int alen, c, s;
2931 int udp_pkts = 0;
2932 int tun_pkts = 0;
2933 int cluster_pkts = 0;
2934
2935 // nsctl commands
2936 if (FD_ISSET(controlfd, &r))
2937 {
2938 alen = sizeof(addr);
2939 processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
2940 n--;
2941 }
2942
2943 // RADIUS responses
2944 if (config->cluster_iam_master)
2945 {
2946 for (i = 0; i < config->num_radfds; i++)
2947 {
2948 if (FD_ISSET(radfds[i], &r))
2949 {
2950 processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
2951 n--;
2952 }
2953 }
2954 }
2955
2956 // CLI connections
2957 if (FD_ISSET(clifd, &r))
2958 {
2959 int cli;
2960
2961 alen = sizeof(addr);
2962 if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
2963 {
2964 cli_do(cli);
2965 close(cli);
2966 }
2967 else
2968 LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
2969
2970 n--;
2971 }
2972
2973 #ifdef BGP
2974 for (i = 0; i < BGP_NUM_PEERS; i++)
2975 {
2976 int isr = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0;
2977 int isw = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0;
2978 bgp_process(&bgp_peers[i], isr, isw);
2979 if (isr) n--;
2980 if (isw) n--;
2981 }
2982 #endif /* BGP */
2983
2984 for (c = 0; n && c < config->multi_read_count; c++)
2985 {
2986 // L2TP
2987 if (FD_ISSET(udpfd, &r))
2988 {
2989 alen = sizeof(addr);
2990 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
2991 {
2992 processudp(buf, s, &addr);
2993 udp_pkts++;
2994 }
2995 else
2996 {
2997 FD_CLR(udpfd, &r);
2998 n--;
2999 }
3000 }
3001
3002 // incoming IP
3003 if (FD_ISSET(tunfd, &r))
3004 {
3005 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
3006 {
3007 processtun(buf, s);
3008 tun_pkts++;
3009 }
3010 else
3011 {
3012 FD_CLR(tunfd, &r);
3013 n--;
3014 }
3015 }
3016
3017 // cluster
3018 if (FD_ISSET(cluster_sockfd, &r))
3019 {
3020 alen = sizeof(addr);
3021 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
3022 {
3023 processcluster(buf, s, addr.sin_addr.s_addr);
3024 cluster_pkts++;
3025 }
3026 else
3027 {
3028 FD_CLR(cluster_sockfd, &r);
3029 n--;
3030 }
3031 }
3032 }
3033
3034 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
3035 STAT(multi_read_used);
3036
3037 if (c >= config->multi_read_count)
3038 {
3039 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
3040 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3041
3042 STAT(multi_read_exceeded);
3043 }
3044 }
3045
3046 // Runs on every machine (master and slaves).
3047 if (cluster_sockfd && next_cluster_ping <= TIME)
3048 {
3049 // Check to see which of the cluster is still alive..
3050
3051 cluster_send_ping(basetime); // Only does anything if we're a slave
3052 cluster_check_master(); // ditto.
3053
3054 cluster_heartbeat(); // Only does anything if we're a master.
3055 cluster_check_slaves(); // ditto.
3056
3057 master_update_counts(); // If we're a slave, send our byte counters to our master.
3058
3059 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3060 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3061 else
3062 next_cluster_ping = TIME + config->cluster_hb_interval;
3063 }
3064
3065 // Run token bucket filtering queue..
3066 // Only run it every 1/10th of a second.
3067 // Runs on all machines both master and slave.
3068 {
3069 static clockt last_run = 0;
3070 if (last_run != TIME)
3071 {
3072 last_run = TIME;
3073 tbf_run_timer();
3074 }
3075 }
3076
3077 /* Handle timeouts. Make sure that this gets run anyway, even if there was
3078 * something to read, else under load this will never actually run....
3079 *
3080 */
3081 if (config->cluster_iam_master && next_clean <= time_now)
3082 {
3083 if (regular_cleanups())
3084 {
3085 // Did it finish?
3086 next_clean = time_now + 1 ; // Didn't finish. Check quickly.
3087 }
3088 else
3089 {
3090 next_clean = time_now + config->cleanup_interval; // Did. Move to next interval.
3091 }
3092 }
3093 }
3094
3095 // Are we the master and shutting down??
3096 if (config->cluster_iam_master)
3097 cluster_heartbeat(); // Flush any queued changes..
3098
3099 // Ok. Notify everyone we're shutting down. If we're
3100 // the master, this will force an election.
3101 cluster_send_ping(0);
3102
3103 //
3104 // Important!!! We MUST not process any packets past this point!
3105 }
3106
3107 static void stripdomain(char *host)
3108 {
3109 char *p;
3110
3111 if ((p = strchr(host, '.')))
3112 {
3113 char *domain = 0;
3114 char _domain[1024];
3115
3116 // strip off domain
3117 FILE *resolv = fopen("/etc/resolv.conf", "r");
3118 if (resolv)
3119 {
3120 char buf[1024];
3121 char *b;
3122
3123 while (fgets(buf, sizeof(buf), resolv))
3124 {
3125 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3126 continue;
3127
3128 if (!isspace(buf[6]))
3129 continue;
3130
3131 b = buf + 7;
3132 while (isspace(*b)) b++;
3133
3134 if (*b)
3135 {
3136 char *d = b;
3137 while (*b && !isspace(*b)) b++;
3138 *b = 0;
3139 if (buf[0] == 'd') // domain is canonical
3140 {
3141 domain = d;
3142 break;
3143 }
3144
3145 // first search line
3146 if (!domain)
3147 {
3148 // hold, may be subsequent domain line
3149 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3150 domain = _domain;
3151 }
3152 }
3153 }
3154
3155 fclose(resolv);
3156 }
3157
3158 if (domain)
3159 {
3160 int hl = strlen(host);
3161 int dl = strlen(domain);
3162 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3163 host[hl -dl - 1] = 0;
3164 }
3165 else
3166 {
3167 *p = 0; // everything after first dot
3168 }
3169 }
3170 }
3171
3172 // Init data structures
3173 static void initdata(int optdebug, char *optconfig)
3174 {
3175 int i;
3176
3177 if (!(config = shared_malloc(sizeof(configt))))
3178 {
3179 fprintf(stderr, "Error doing malloc for configuration: %s\n", strerror(errno));
3180 exit(1);
3181 }
3182
3183 memset(config, 0, sizeof(configt));
3184 time(&config->start_time);
3185 strncpy(config->config_file, optconfig, strlen(optconfig));
3186 config->debug = optdebug;
3187 config->num_tbfs = MAXTBFS;
3188 config->rl_rate = 28; // 28kbps
3189 strcpy(config->random_device, RANDOMDEVICE);
3190
3191 log_stream = stderr;
3192
3193 #ifdef RINGBUFFER
3194 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3195 {
3196 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3197 exit(1);
3198 }
3199 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3200 #endif
3201
3202 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3203 {
3204 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3205 exit(1);
3206 }
3207 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3208 {
3209 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3210 exit(1);
3211 }
3212 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3213 {
3214 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3215 exit(1);
3216 }
3217
3218 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3219 {
3220 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3221 exit(1);
3222 }
3223
3224 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3225 {
3226 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3227 exit(1);
3228 }
3229
3230 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3231 {
3232 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3233 exit(1);
3234 }
3235
3236 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3237 {
3238 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3239 exit(1);
3240 }
3241 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3242
3243 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3244 {
3245 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3246 exit(1);
3247 }
3248 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3249
3250 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3251 {
3252 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3253 exit(1);
3254 }
3255 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3256
3257 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3258 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3259 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3260 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3261
3262 // Put all the sessions on the free list marked as undefined.
3263 for (i = 1; i < MAXSESSION; i++)
3264 {
3265 session[i].next = i + 1;
3266 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3267 }
3268 session[MAXSESSION - 1].next = 0;
3269 sessionfree = 1;
3270
3271 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3272 for (i = 1; i < MAXTUNNEL; i++)
3273 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3274
3275 if (!*hostname)
3276 {
3277 // Grab my hostname unless it's been specified
3278 gethostname(hostname, sizeof(hostname));
3279 stripdomain(hostname);
3280 }
3281
3282 _statistics->start_time = _statistics->last_reset = time(NULL);
3283
3284 #ifdef BGP
3285 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3286 {
3287 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3288 exit(1);
3289 }
3290 #endif /* BGP */
3291 }
3292
3293 static int assign_ip_address(sessionidt s)
3294 {
3295 uint32_t i;
3296 int best = -1;
3297 time_t best_time = time_now;
3298 char *u = session[s].user;
3299 char reuse = 0;
3300
3301
3302 CSTAT(assign_ip_address);
3303
3304 for (i = 1; i < ip_pool_size; i++)
3305 {
3306 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3307 continue;
3308
3309 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3310 {
3311 best = i;
3312 reuse = 1;
3313 break;
3314 }
3315
3316 if (ip_address_pool[i].last < best_time)
3317 {
3318 best = i;
3319 if (!(best_time = ip_address_pool[i].last))
3320 break; // never used, grab this one
3321 }
3322 }
3323
3324 if (best < 0)
3325 {
3326 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3327 return 0;
3328 }
3329
3330 session[s].ip = ip_address_pool[best].address;
3331 session[s].ip_pool_index = best;
3332 ip_address_pool[best].assigned = 1;
3333 ip_address_pool[best].last = time_now;
3334 ip_address_pool[best].session = s;
3335 if (session[s].walled_garden)
3336 /* Don't track addresses of users in walled garden (note: this
3337 means that their address isn't "sticky" even if they get
3338 un-gardened). */
3339 ip_address_pool[best].user[0] = 0;
3340 else
3341 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3342
3343 STAT(ip_allocated);
3344 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3345 reuse ? "Reusing" : "Allocating", best);
3346
3347 return 1;
3348 }
3349
3350 static void free_ip_address(sessionidt s)
3351 {
3352 int i = session[s].ip_pool_index;
3353
3354
3355 CSTAT(free_ip_address);
3356
3357 if (!session[s].ip)
3358 return; // what the?
3359
3360 if (i < 0) // Is this actually part of the ip pool?
3361 i = 0;
3362
3363 STAT(ip_freed);
3364 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3365 session[s].ip = 0;
3366 ip_address_pool[i].assigned = 0;
3367 ip_address_pool[i].session = 0;
3368 ip_address_pool[i].last = time_now;
3369 }
3370
3371 //
3372 // Fsck the address pool against the session table.
3373 // Normally only called when we become a master.
3374 //
3375 // This isn't perfect: We aren't keep tracking of which
3376 // users used to have an IP address.
3377 //
3378 void rebuild_address_pool(void)
3379 {
3380 int i;
3381
3382 //
3383 // Zero the IP pool allocation, and build
3384 // a map from IP address to pool index.
3385 for (i = 1; i < MAXIPPOOL; ++i)
3386 {
3387 ip_address_pool[i].assigned = 0;
3388 ip_address_pool[i].session = 0;
3389 if (!ip_address_pool[i].address)
3390 continue;
3391
3392 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3393 }
3394
3395 for (i = 0; i < MAXSESSION; ++i)
3396 {
3397 int ipid;
3398 if (!(session[i].opened && session[i].ip))
3399 continue;
3400
3401 ipid = - lookup_ipmap(htonl(session[i].ip));
3402
3403 if (session[i].ip_pool_index < 0)
3404 {
3405 // Not allocated out of the pool.
3406 if (ipid < 1) // Not found in the pool either? good.
3407 continue;
3408
3409 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3410 i, fmtaddr(session[i].ip, 0), ipid);
3411
3412 // Fall through and process it as part of the pool.
3413 }
3414
3415
3416 if (ipid > MAXIPPOOL || ipid < 0)
3417 {
3418 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3419 ipid = -1;
3420 session[i].ip_pool_index = ipid;
3421 continue;
3422 }
3423
3424 ip_address_pool[ipid].assigned = 1;
3425 ip_address_pool[ipid].session = i;
3426 ip_address_pool[ipid].last = time_now;
3427 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3428 session[i].ip_pool_index = ipid;
3429 cache_ipmap(session[i].ip, i); // Fix the ip map.
3430 }
3431 }
3432
3433 //
3434 // Fix the address pool to match a changed session.
3435 // (usually when the master sends us an update).
3436 static void fix_address_pool(int sid)
3437 {
3438 int ipid;
3439
3440 ipid = session[sid].ip_pool_index;
3441
3442 if (ipid > ip_pool_size)
3443 return; // Ignore it. rebuild_address_pool will fix it up.
3444
3445 if (ip_address_pool[ipid].address != session[sid].ip)
3446 return; // Just ignore it. rebuild_address_pool will take care of it.
3447
3448 ip_address_pool[ipid].assigned = 1;
3449 ip_address_pool[ipid].session = sid;
3450 ip_address_pool[ipid].last = time_now;
3451 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3452 }
3453
3454 //
3455 // Add a block of addresses to the IP pool to hand out.
3456 //
3457 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3458 {
3459 int i;
3460 if (mask == 0)
3461 mask = 0xffffffff; // Host route only.
3462
3463 addr &= mask;
3464
3465 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3466 return ;
3467
3468 for (i = addr ;(i & mask) == addr; ++i)
3469 {
3470 if ((i & 0xff) == 0 || (i&0xff) == 255)
3471 continue; // Skip 0 and broadcast addresses.
3472
3473 ip_address_pool[ip_pool_size].address = i;
3474 ip_address_pool[ip_pool_size].assigned = 0;
3475 ++ip_pool_size;
3476 if (ip_pool_size >= MAXIPPOOL)
3477 {
3478 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3479 return;
3480 }
3481 }
3482 }
3483
3484 // Initialize the IP address pool
3485 static void initippool()
3486 {
3487 FILE *f;
3488 char *p;
3489 char buf[4096];
3490 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3491
3492 if (!(f = fopen(IPPOOLFILE, "r")))
3493 {
3494 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3495 exit(1);
3496 }
3497
3498 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3499 {
3500 char *pool = buf;
3501 buf[4095] = 0; // Force it to be zero terminated/
3502
3503 if (*buf == '#' || *buf == '\n')
3504 continue; // Skip comments / blank lines
3505 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3506 if ((p = (char *)strchr(buf, ':')))
3507 {
3508 in_addr_t src;
3509 *p = '\0';
3510 src = inet_addr(buf);
3511 if (src == INADDR_NONE)
3512 {
3513 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3514 exit(1);
3515 }
3516 // This entry is for a specific IP only
3517 if (src != config->bind_address)
3518 continue;
3519 *p = ':';
3520 pool = p+1;
3521 }
3522 if ((p = (char *)strchr(pool, '/')))
3523 {
3524 // It's a range
3525 int numbits = 0;
3526 in_addr_t start = 0, mask = 0;
3527
3528 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3529 *p++ = 0;
3530 if (!*p || !(numbits = atoi(p)))
3531 {
3532 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3533 continue;
3534 }
3535 start = ntohl(inet_addr(pool));
3536 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3537
3538 // Add a static route for this pool
3539 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3540 fmtaddr(htonl(start), 0), 32 + mask);
3541
3542 routeset(0, start, mask, 0, 1);
3543
3544 add_to_ip_pool(start, mask);
3545 }
3546 else
3547 {
3548 // It's a single ip address
3549 add_to_ip_pool(inet_addr(pool), 0);
3550 }
3551 }
3552 fclose(f);
3553 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3554 }
3555
3556 void snoop_send_packet(char *packet, uint16_t size, in_addr_t destination, uint16_t port)
3557 {
3558 struct sockaddr_in snoop_addr = {0};
3559 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3560 return;
3561
3562 snoop_addr.sin_family = AF_INET;
3563 snoop_addr.sin_addr.s_addr = destination;
3564 snoop_addr.sin_port = ntohs(port);
3565
3566 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3567 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3568 htons(snoop_addr.sin_port));
3569
3570 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3571 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
3572
3573 STAT(packets_snooped);
3574 }
3575
3576 static int dump_session(FILE **f, sessiont *s)
3577 {
3578 if (!s->opened || !s->ip || !(s->cin || s->cout) || !*s->user || s->walled_garden)
3579 return 1;
3580
3581 if (!*f)
3582 {
3583 char filename[1024];
3584 char timestr[64];
3585 time_t now = time(NULL);
3586
3587 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
3588 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
3589
3590 if (!(*f = fopen(filename, "w")))
3591 {
3592 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
3593 return 0;
3594 }
3595
3596 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
3597 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
3598 "# host: %s\n"
3599 "# time: %ld\n"
3600 "# uptime: %ld\n"
3601 "# format: username ip qos uptxoctets downrxoctets\n",
3602 hostname,
3603 now,
3604 now - basetime);
3605 }
3606
3607 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
3608 fprintf(*f, "%s %s %d %u %u\n",
3609 s->user, // username
3610 fmtaddr(htonl(s->ip), 0), // ip
3611 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
3612 (uint32_t) s->cin, // uptxoctets
3613 (uint32_t) s->cout); // downrxoctets
3614
3615 s->pin = s->cin = 0;
3616 s->pout = s->cout = 0;
3617
3618 return 1;
3619 }
3620
3621 static void dump_acct_info(int all)
3622 {
3623 int i;
3624 FILE *f = NULL;
3625
3626
3627 CSTAT(dump_acct_info);
3628
3629 if (shut_acct_n)
3630 {
3631 for (i = 0; i < shut_acct_n; i++)
3632 dump_session(&f, &shut_acct[i]);
3633
3634 shut_acct_n = 0;
3635 }
3636
3637 if (all)
3638 for (i = 1; i <= config->cluster_highest_sessionid; i++)
3639 dump_session(&f, &session[i]);
3640
3641 if (f)
3642 fclose(f);
3643 }
3644
3645 // Main program
3646 int main(int argc, char *argv[])
3647 {
3648 int i;
3649 int optdebug = 0;
3650 char *optconfig = CONFIGFILE;
3651
3652 time(&basetime); // start clock
3653
3654 // scan args
3655 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
3656 {
3657 switch (i)
3658 {
3659 case 'd':
3660 if (fork()) exit(0);
3661 setsid();
3662 freopen("/dev/null", "r", stdin);
3663 freopen("/dev/null", "w", stdout);
3664 freopen("/dev/null", "w", stderr);
3665 break;
3666 case 'v':
3667 optdebug++;
3668 break;
3669 case 'c':
3670 optconfig = optarg;
3671 break;
3672 case 'h':
3673 snprintf(hostname, sizeof(hostname), "%s", optarg);
3674 break;
3675 default:
3676 printf("Args are:\n"
3677 "\t-d\t\tDetach from terminal\n"
3678 "\t-c <file>\tConfig file\n"
3679 "\t-h <hostname>\tForce hostname\n"
3680 "\t-v\t\tDebug\n");
3681
3682 return (0);
3683 break;
3684 }
3685 }
3686
3687 // Start the timer routine off
3688 time(&time_now);
3689 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3690 signal(SIGALRM, sigalrm_handler);
3691 siginterrupt(SIGALRM, 0);
3692
3693 initplugins();
3694 initdata(optdebug, optconfig);
3695
3696 init_cli(hostname);
3697 read_config_file();
3698 init_tbf(config->num_tbfs);
3699
3700 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
3701 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
3702 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
3703 {
3704 struct rlimit rlim;
3705 rlim.rlim_cur = RLIM_INFINITY;
3706 rlim.rlim_max = RLIM_INFINITY;
3707 // Remove the maximum core size
3708 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
3709 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
3710
3711 // Make core dumps go to /tmp
3712 chdir("/tmp");
3713 }
3714
3715 if (config->scheduler_fifo)
3716 {
3717 int ret;
3718 struct sched_param params = {0};
3719 params.sched_priority = 1;
3720
3721 if (get_nprocs() < 2)
3722 {
3723 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
3724 config->scheduler_fifo = 0;
3725 }
3726 else
3727 {
3728 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
3729 {
3730 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
3731 }
3732 else
3733 {
3734 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
3735 config->scheduler_fifo = 0;
3736 }
3737 }
3738 }
3739
3740 /* Set up the cluster communications port. */
3741 if (cluster_init() < 0)
3742 exit(1);
3743
3744 #ifdef BGP
3745 signal(SIGPIPE, SIG_IGN);
3746 bgp_setup(config->as_number);
3747 bgp_add_route(config->bind_address, 0xffffffff);
3748 for (i = 0; i < BGP_NUM_PEERS; i++)
3749 {
3750 if (config->neighbour[i].name[0])
3751 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3752 config->neighbour[i].as, config->neighbour[i].keepalive,
3753 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3754 }
3755 #endif /* BGP */
3756
3757 inittun();
3758 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
3759
3760 initudp();
3761 initrad();
3762 initippool();
3763
3764 signal(SIGHUP, sighup_handler);
3765 signal(SIGTERM, sigterm_handler);
3766 signal(SIGINT, sigterm_handler);
3767 signal(SIGQUIT, sigquit_handler);
3768 signal(SIGCHLD, sigchild_handler);
3769
3770 // Prevent us from getting paged out
3771 if (config->lock_pages)
3772 {
3773 if (!mlockall(MCL_CURRENT))
3774 LOG(1, 0, 0, "Locking pages into memory\n");
3775 else
3776 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
3777 }
3778
3779 alarm(1);
3780
3781 // Drop privileges here
3782 if (config->target_uid > 0 && geteuid() == 0)
3783 setuid(config->target_uid);
3784
3785 mainloop();
3786
3787 #ifdef BGP
3788 /* try to shut BGP down cleanly; with luck the sockets will be
3789 writable since we're out of the select */
3790 for (i = 0; i < BGP_NUM_PEERS; i++)
3791 if (bgp_peers[i].state == Established)
3792 bgp_stop(&bgp_peers[i]);
3793 #endif /* BGP */
3794
3795 /* remove plugins (so cleanup code gets run) */
3796 plugins_done();
3797
3798 // Remove the PID file if we wrote it
3799 if (config->wrote_pid && *config->pid_file == '/')
3800 unlink(config->pid_file);
3801
3802 /* kill CLI children */
3803 signal(SIGTERM, SIG_IGN);
3804 kill(0, SIGTERM);
3805 return 0;
3806 }
3807
3808 static void sighup_handler(int sig)
3809 {
3810 if (log_stream)
3811 {
3812 if (log_stream != stderr)
3813 fclose(log_stream);
3814
3815 log_stream = NULL;
3816 }
3817
3818 read_config_file();
3819 }
3820
3821 static void sigalrm_handler(int sig)
3822 {
3823 // Log current traffic stats
3824
3825 snprintf(config->bandwidth, sizeof(config->bandwidth),
3826 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3827 (udp_rx / 1024.0 / 1024.0 * 8),
3828 (eth_tx / 1024.0 / 1024.0 * 8),
3829 (eth_rx / 1024.0 / 1024.0 * 8),
3830 (udp_tx / 1024.0 / 1024.0 * 8),
3831 ((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
3832 udp_rx_pkt, eth_rx_pkt);
3833
3834 udp_tx = udp_rx = 0;
3835 udp_rx_pkt = eth_rx_pkt = 0;
3836 eth_tx = eth_rx = 0;
3837
3838 if (config->dump_speed)
3839 printf("%s\n", config->bandwidth);
3840
3841 // Update the internal time counter
3842 time(&time_now);
3843 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3844 alarm(1);
3845
3846 {
3847 // Run timer hooks
3848 struct param_timer p = { time_now };
3849 run_plugins(PLUGIN_TIMER, &p);
3850 }
3851
3852 }
3853
3854 static void sigterm_handler(int sig)
3855 {
3856 LOG(1, 0, 0, "Shutting down cleanly\n");
3857 main_quit++;
3858 }
3859
3860 static void sigquit_handler(int sig)
3861 {
3862 int i;
3863
3864 LOG(1, 0, 0, "Shutting down without saving sessions\n");
3865
3866 if (config->cluster_iam_master)
3867 {
3868 for (i = 1; i < MAXSESSION; i++)
3869 {
3870 if (session[i].opened)
3871 sessionkill(i, "L2TPNS Closing");
3872 }
3873 for (i = 1; i < MAXTUNNEL; i++)
3874 {
3875 if (tunnel[i].ip || tunnel[i].state)
3876 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3877 }
3878 }
3879
3880 main_quit++;
3881 }
3882
3883 static void sigchild_handler(int sig)
3884 {
3885 while (waitpid(-1, NULL, WNOHANG) > 0)
3886 ;
3887 }
3888
3889 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
3890 {
3891 MD5_CTX ctx;
3892 *challenge_response = NULL;
3893
3894 if (!*config->l2tpsecret)
3895 {
3896 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
3897 return;
3898 }
3899
3900 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
3901
3902 *challenge_response = (char *)calloc(17, 1);
3903
3904 MD5Init(&ctx);
3905 MD5Update(&ctx, &id, 1);
3906 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
3907 MD5Update(&ctx, challenge, challenge_length);
3908 MD5Final(*challenge_response, &ctx);
3909
3910 return;
3911 }
3912
3913 static int facility_value(char *name)
3914 {
3915 int i;
3916 for (i = 0; facilitynames[i].c_name; i++)
3917 {
3918 if (strcmp(facilitynames[i].c_name, name) == 0)
3919 return facilitynames[i].c_val;
3920 }
3921 return 0;
3922 }
3923
3924 static void update_config()
3925 {
3926 int i;
3927 char *p;
3928 static int timeout = 0;
3929 static int interval = 0;
3930
3931 // Update logging
3932 closelog();
3933 syslog_log = 0;
3934 if (log_stream)
3935 {
3936 if (log_stream != stderr)
3937 fclose(log_stream);
3938
3939 log_stream = NULL;
3940 }
3941
3942 if (*config->log_filename)
3943 {
3944 if (strstr(config->log_filename, "syslog:") == config->log_filename)
3945 {
3946 char *p = config->log_filename + 7;
3947 if (*p)
3948 {
3949 openlog("l2tpns", LOG_PID, facility_value(p));
3950 syslog_log = 1;
3951 }
3952 }
3953 else if (strchr(config->log_filename, '/') == config->log_filename)
3954 {
3955 if ((log_stream = fopen((char *)(config->log_filename), "a")))
3956 {
3957 fseek(log_stream, 0, SEEK_END);
3958 setbuf(log_stream, NULL);
3959 }
3960 else
3961 {
3962 log_stream = stderr;
3963 setbuf(log_stream, NULL);
3964 }
3965 }
3966 }
3967 else
3968 {
3969 log_stream = stderr;
3970 setbuf(log_stream, NULL);
3971 }
3972
3973 // Update radius
3974 config->numradiusservers = 0;
3975 for (i = 0; i < MAXRADSERVER; i++)
3976 if (config->radiusserver[i])
3977 {
3978 config->numradiusservers++;
3979 // Set radius port: if not set, take the port from the
3980 // first radius server. For the first radius server,
3981 // take the #defined default value from l2tpns.h
3982
3983 // test twice, In case someone works with
3984 // a secondary radius server without defining
3985 // a primary one, this will work even then.
3986 if (i>0 && !config->radiusport[i])
3987 config->radiusport[i] = config->radiusport[i-1];
3988 if (!config->radiusport[i])
3989 config->radiusport[i] = RADPORT;
3990 }
3991
3992 if (!config->numradiusservers)
3993 LOG(0, 0, 0, "No RADIUS servers defined!\n");
3994
3995 config->num_radfds = 2 << RADIUS_SHIFT;
3996
3997 // parse radius_authtypes_s
3998 config->radius_authtypes = config->radius_authprefer = 0;
3999 p = config->radius_authtypes_s;
4000 while (*p)
4001 {
4002 char *s = strpbrk(p, " \t,");
4003 int type = 0;
4004
4005 if (s)
4006 {
4007 *s++ = 0;
4008 while (*s == ' ' || *s == '\t')
4009 s++;
4010
4011 if (!*s)
4012 s = 0;
4013 }
4014
4015 if (!strncasecmp("chap", p, strlen(p)))
4016 type = AUTHCHAP;
4017 else if (!strncasecmp("pap", p, strlen(p)))
4018 type = AUTHPAP;
4019 else
4020 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"\n", p);
4021
4022 config->radius_authtypes |= type;
4023 if (!config->radius_authprefer)
4024 config->radius_authprefer = type;
4025 }
4026
4027 if (!config->radius_authtypes)
4028 {
4029 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
4030 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
4031 }
4032
4033 // normalise radius_authtypes_s
4034 if (config->radius_authprefer == AUTHPAP)
4035 {
4036 strcpy(config->radius_authtypes_s, "pap");
4037 if (config->radius_authtypes & AUTHCHAP)
4038 strcat(config->radius_authtypes_s, ", chap");
4039 }
4040 else
4041 {
4042 strcpy(config->radius_authtypes_s, "chap");
4043 if (config->radius_authtypes & AUTHPAP)
4044 strcat(config->radius_authtypes_s, ", pap");
4045 }
4046
4047 // re-initialise the random number source
4048 initrandom(config->random_device);
4049
4050 // Update plugins
4051 for (i = 0; i < MAXPLUGINS; i++)
4052 {
4053 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4054 continue;
4055
4056 if (*config->plugins[i])
4057 {
4058 // Plugin added
4059 add_plugin(config->plugins[i]);
4060 }
4061 else if (*config->old_plugins[i])
4062 {
4063 // Plugin removed
4064 remove_plugin(config->old_plugins[i]);
4065 }
4066 }
4067
4068 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4069 if (!config->cleanup_interval) config->cleanup_interval = 10;
4070 if (!config->multi_read_count) config->multi_read_count = 10;
4071 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4072 if (!*config->cluster_interface)
4073 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4074
4075 if (!config->cluster_hb_interval)
4076 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4077
4078 if (!config->cluster_hb_timeout)
4079 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4080
4081 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4082 {
4083 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4084 // late, ensure we're sufficiently larger than that
4085 int t = 4 * config->cluster_hb_interval + 11;
4086
4087 if (config->cluster_hb_timeout < t)
4088 {
4089 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4090 config->cluster_hb_timeout = t;
4091 }
4092
4093 // Push timing changes to the slaves immediately if we're the master
4094 if (config->cluster_iam_master)
4095 cluster_heartbeat();
4096
4097 interval = config->cluster_hb_interval;
4098 timeout = config->cluster_hb_timeout;
4099 }
4100
4101 // Write PID file
4102 if (*config->pid_file == '/' && !config->wrote_pid)
4103 {
4104 FILE *f;
4105 if ((f = fopen(config->pid_file, "w")))
4106 {
4107 fprintf(f, "%d\n", getpid());
4108 fclose(f);
4109 config->wrote_pid = 1;
4110 }
4111 else
4112 {
4113 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4114 }
4115 }
4116
4117 config->reload_config = 0;
4118 }
4119
4120 static void read_config_file()
4121 {
4122 FILE *f;
4123
4124 if (!config->config_file) return;
4125 if (!(f = fopen(config->config_file, "r")))
4126 {
4127 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4128 return;
4129 }
4130
4131 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4132 cli_do_file(f);
4133 LOG(3, 0, 0, "Done reading config file\n");
4134 fclose(f);
4135 update_config();
4136 }
4137
4138 int sessionsetup(tunnelidt t, sessionidt s)
4139 {
4140 // A session now exists, set it up
4141 in_addr_t ip;
4142 char *user;
4143 sessionidt i;
4144 int r;
4145
4146 CSTAT(sessionsetup);
4147
4148 LOG(3, s, t, "Doing session setup for session\n");
4149
4150 if (!session[s].ip)
4151 {
4152 assign_ip_address(s);
4153 if (!session[s].ip)
4154 {
4155 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4156 sessionshutdown(s, "No IP addresses available.", 2, 7);
4157 return 0;
4158 }
4159 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4160 fmtaddr(htonl(session[s].ip), 0));
4161 }
4162
4163
4164 // Make sure this is right
4165 session[s].tunnel = t;
4166
4167 // zap old sessions with same IP and/or username
4168 // Don't kill gardened sessions - doing so leads to a DoS
4169 // from someone who doesn't need to know the password
4170 {
4171 ip = session[s].ip;
4172 user = session[s].user;
4173 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4174 {
4175 if (i == s) continue;
4176 if (ip == session[i].ip) sessionkill(i, "Duplicate IP address");
4177 if (!session[s].walled_garden && !session[i].walled_garden && strcasecmp(user, session[i].user) == 0)
4178 sessionkill(i, "Duplicate session for users");
4179 }
4180 }
4181
4182 {
4183 int routed = 0;
4184
4185 // Add the route for this session.
4186 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4187 {
4188 if ((session[s].ip & session[s].route[r].mask) ==
4189 (session[s].route[r].ip & session[s].route[r].mask))
4190 routed++;
4191
4192 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4193 }
4194
4195 // Static IPs need to be routed if not already
4196 // convered by a Framed-Route. Anything else is part
4197 // of the IP address pool and is already routed, it
4198 // just needs to be added to the IP cache.
4199 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4200 if (session[s].ip_pool_index == -1) // static ip
4201 {
4202 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4203 }
4204 else
4205 cache_ipmap(session[s].ip, s);
4206 }
4207
4208 if (!session[s].unique_id)
4209 {
4210 // did this session just finish radius?
4211 LOG(3, s, t, "Sending initial IPCP to client\n");
4212 sendipcp(t, s);
4213 session[s].unique_id = ++last_id;
4214 }
4215
4216 // Run the plugin's against this new session.
4217 {
4218 struct param_new_session data = { &tunnel[t], &session[s] };
4219 run_plugins(PLUGIN_NEW_SESSION, &data);
4220 }
4221
4222 // Allocate TBFs if throttled
4223 if (session[s].throttle_in || session[s].throttle_out)
4224 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4225
4226 session[s].last_packet = time_now;
4227
4228 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4229 fmtaddr(htonl(session[s].ip), 0),
4230 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4231
4232 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4233
4234 return 1; // RADIUS OK and IP allocated, done...
4235 }
4236
4237 //
4238 // This session just got dropped on us by the master or something.
4239 // Make sure our tables up up to date...
4240 //
4241 int load_session(sessionidt s, sessiont *new)
4242 {
4243 int i;
4244 int newip = 0;
4245
4246 // Sanity checks.
4247 if (new->ip_pool_index >= MAXIPPOOL ||
4248 new->tunnel >= MAXTUNNEL)
4249 {
4250 LOG(0, s, 0, "Strange session update received!\n");
4251 // FIXME! What to do here?
4252 return 0;
4253 }
4254
4255 //
4256 // Ok. All sanity checks passed. Now we're committed to
4257 // loading the new session.
4258 //
4259
4260 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4261
4262 // See if routes/ip cache need updating
4263 if (new->ip != session[s].ip)
4264 newip++;
4265
4266 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4267 if (new->route[i].ip != session[s].route[i].ip ||
4268 new->route[i].mask != session[s].route[i].mask)
4269 newip++;
4270
4271 // needs update
4272 if (newip)
4273 {
4274 int routed = 0;
4275
4276 // remove old routes...
4277 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4278 {
4279 if ((session[s].ip & session[s].route[i].mask) ==
4280 (session[s].route[i].ip & session[s].route[i].mask))
4281 routed++;
4282
4283 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4284 }
4285
4286 // ...ip
4287 if (session[s].ip)
4288 {
4289 if (session[s].ip_pool_index == -1) // static IP
4290 {
4291 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4292 }
4293 else // It's part of the IP pool, remove it manually.
4294 uncache_ipmap(session[s].ip);
4295 }
4296
4297 routed = 0;
4298
4299 // add new routes...
4300 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4301 {
4302 if ((new->ip & new->route[i].mask) ==
4303 (new->route[i].ip & new->route[i].mask))
4304 routed++;
4305
4306 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4307 }
4308
4309 // ...ip
4310 if (new->ip)
4311 {
4312 // If there's a new one, add it.
4313 if (new->ip_pool_index == -1)
4314 {
4315 if (!routed) routeset(s, new->ip, 0, 0, 1);
4316 }
4317 else
4318 cache_ipmap(new->ip, s);
4319 }
4320 }
4321
4322 // check v6 routing
4323 if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED))
4324 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4325
4326 // check filters
4327 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4328 {
4329 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4330 new->filter_in = 0;
4331 }
4332
4333 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4334 {
4335 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4336 new->filter_out = 0;
4337 }
4338
4339 if (new->filter_in != session[s].filter_in)
4340 {
4341 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4342 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4343 }
4344
4345 if (new->filter_out != session[s].filter_out)
4346 {
4347 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4348 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4349 }
4350
4351 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4352 // for walking the sessions to forward byte counts to the master.
4353 config->cluster_highest_sessionid = s;
4354
4355 // TEMP: old session struct used a uint32_t to define the throttle
4356 // speed for both up/down, new uses a uint16_t for each. Deal with
4357 // sessions from an old master for migration.
4358 if (new->throttle_out == 0 && new->tbf_out)
4359 new->throttle_out = new->throttle_in;
4360
4361 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4362
4363 // Do fixups into address pool.
4364 if (new->ip_pool_index != -1)
4365 fix_address_pool(s);
4366
4367 return 1;
4368 }
4369
4370 static void initplugins()
4371 {
4372 int i;
4373
4374 loaded_plugins = ll_init();
4375 // Initialize the plugins to nothing
4376 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4377 plugins[i] = ll_init();
4378 }
4379
4380 static void *open_plugin(char *plugin_name, int load)
4381 {
4382 char path[256] = "";
4383
4384 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4385 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4386 return dlopen(path, RTLD_NOW);
4387 }
4388
4389 // plugin callback to get a config value
4390 static void *getconfig(char *key, enum config_typet type)
4391 {
4392 int i;
4393
4394 for (i = 0; config_values[i].key; i++)
4395 {
4396 if (!strcmp(config_values[i].key, key))
4397 {
4398 if (config_values[i].type == type)
4399 return ((void *) config) + config_values[i].offset;
4400
4401 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4402 key, type, config_values[i].type);
4403
4404 return 0;
4405 }
4406 }
4407
4408 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4409 return 0;
4410 }
4411
4412 static int add_plugin(char *plugin_name)
4413 {
4414 static struct pluginfuncs funcs = {
4415 _log,
4416 _log_hex,
4417 fmtaddr,
4418 sessionbyuser,
4419 sessiontbysessionidt,
4420 sessionidtbysessiont,
4421 radiusnew,
4422 radiussend,
4423 getconfig,
4424 sessionkill,
4425 throttle_session,
4426 cluster_send_session,
4427 };
4428
4429 void *p = open_plugin(plugin_name, 1);
4430 int (*initfunc)(struct pluginfuncs *);
4431 int i;
4432
4433 if (!p)
4434 {
4435 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4436 return -1;
4437 }
4438
4439 if (ll_contains(loaded_plugins, p))
4440 {
4441 dlclose(p);
4442 return 0; // already loaded
4443 }
4444
4445 {
4446 int *v = dlsym(p, "plugin_api_version");
4447 if (!v || *v != PLUGIN_API_VERSION)
4448 {
4449 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4450 dlclose(p);
4451 return -1;
4452 }
4453 }
4454
4455 if ((initfunc = dlsym(p, "plugin_init")))
4456 {
4457 if (!initfunc(&funcs))
4458 {
4459 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4460 dlclose(p);
4461 return -1;
4462 }
4463 }
4464
4465 ll_push(loaded_plugins, p);
4466
4467 for (i = 0; i < max_plugin_functions; i++)
4468 {
4469 void *x;
4470 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4471 {
4472 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4473 ll_push(plugins[i], x);
4474 }
4475 }
4476
4477 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4478 return 1;
4479 }
4480
4481 static void run_plugin_done(void *plugin)
4482 {
4483 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4484
4485 if (donefunc)
4486 donefunc();
4487 }
4488
4489 static int remove_plugin(char *plugin_name)
4490 {
4491 void *p = open_plugin(plugin_name, 0);
4492 int loaded = 0;
4493
4494 if (!p)
4495 return -1;
4496
4497 if (ll_contains(loaded_plugins, p))
4498 {
4499 int i;
4500 for (i = 0; i < max_plugin_functions; i++)
4501 {
4502 void *x;
4503 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4504 ll_delete(plugins[i], x);
4505 }
4506
4507 ll_delete(loaded_plugins, p);
4508 run_plugin_done(p);
4509 loaded = 1;
4510 }
4511
4512 dlclose(p);
4513 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4514 return loaded;
4515 }
4516
4517 int run_plugins(int plugin_type, void *data)
4518 {
4519 int (*func)(void *data);
4520
4521 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4522 return PLUGIN_RET_ERROR;
4523
4524 ll_reset(plugins[plugin_type]);
4525 while ((func = ll_next(plugins[plugin_type])))
4526 {
4527 int r = func(data);
4528
4529 if (r != PLUGIN_RET_OK)
4530 return r; // stop here
4531 }
4532
4533 return PLUGIN_RET_OK;
4534 }
4535
4536 static void plugins_done()
4537 {
4538 void *p;
4539
4540 ll_reset(loaded_plugins);
4541 while ((p = ll_next(loaded_plugins)))
4542 run_plugin_done(p);
4543 }
4544
4545 static void processcontrol(uint8_t * buf, int len, struct sockaddr_in *addr, int alen)
4546 {
4547 struct nsctl request;
4548 struct nsctl response;
4549 int type = unpack_control(&request, buf, len);
4550 int r;
4551 void *p;
4552
4553 if (log_stream && config->debug >= 4)
4554 {
4555 if (type < 0)
4556 {
4557 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4558 fmtaddr(addr->sin_addr.s_addr, 0), type);
4559 }
4560 else
4561 {
4562 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4563 dump_control(&request, log_stream);
4564 }
4565 }
4566
4567 switch (type)
4568 {
4569 case NSCTL_REQ_LOAD:
4570 if (request.argc != 1)
4571 {
4572 response.type = NSCTL_RES_ERR;
4573 response.argc = 1;
4574 response.argv[0] = "name of plugin required";
4575 }
4576 else if ((r = add_plugin(request.argv[0])) < 1)
4577 {
4578 response.type = NSCTL_RES_ERR;
4579 response.argc = 1;
4580 response.argv[0] = !r
4581 ? "plugin already loaded"
4582 : "error loading plugin";
4583 }
4584 else
4585 {
4586 response.type = NSCTL_RES_OK;
4587 response.argc = 0;
4588 }
4589
4590 break;
4591
4592 case NSCTL_REQ_UNLOAD:
4593 if (request.argc != 1)
4594 {
4595 response.type = NSCTL_RES_ERR;
4596 response.argc = 1;
4597 response.argv[0] = "name of plugin required";
4598 }
4599 else if ((r = remove_plugin(request.argv[0])) < 1)
4600 {
4601 response.type = NSCTL_RES_ERR;
4602 response.argc = 1;
4603 response.argv[0] = !r
4604 ? "plugin not loaded"
4605 : "plugin not found";
4606 }
4607 else
4608 {
4609 response.type = NSCTL_RES_OK;
4610 response.argc = 0;
4611 }
4612
4613 break;
4614
4615 case NSCTL_REQ_HELP:
4616 response.type = NSCTL_RES_OK;
4617 response.argc = 0;
4618
4619 ll_reset(loaded_plugins);
4620 while ((p = ll_next(loaded_plugins)))
4621 {
4622 char **help = dlsym(p, "plugin_control_help");
4623 while (response.argc < 0xff && help && *help)
4624 response.argv[response.argc++] = *help++;
4625 }
4626
4627 break;
4628
4629 case NSCTL_REQ_CONTROL:
4630 {
4631 struct param_control param = {
4632 config->cluster_iam_master,
4633 request.argc,
4634 request.argv,
4635 0,
4636 NULL,
4637 };
4638
4639 int r = run_plugins(PLUGIN_CONTROL, &param);
4640
4641 if (r == PLUGIN_RET_ERROR)
4642 {
4643 response.type = NSCTL_RES_ERR;
4644 response.argc = 1;
4645 response.argv[0] = param.additional
4646 ? param.additional
4647 : "error returned by plugin";
4648 }
4649 else if (r == PLUGIN_RET_NOTMASTER)
4650 {
4651 static char msg[] = "must be run on master: 000.000.000.000";
4652
4653 response.type = NSCTL_RES_ERR;
4654 response.argc = 1;
4655 if (config->cluster_master_address)
4656 {
4657 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
4658 response.argv[0] = msg;
4659 }
4660 else
4661 {
4662 response.argv[0] = "must be run on master: none elected";
4663 }
4664 }
4665 else if (!(param.response & NSCTL_RESPONSE))
4666 {
4667 response.type = NSCTL_RES_ERR;
4668 response.argc = 1;
4669 response.argv[0] = param.response
4670 ? "unrecognised response value from plugin"
4671 : "unhandled action";
4672 }
4673 else
4674 {
4675 response.type = param.response;
4676 response.argc = 0;
4677 if (param.additional)
4678 {
4679 response.argc = 1;
4680 response.argv[0] = param.additional;
4681 }
4682 }
4683 }
4684
4685 break;
4686
4687 default:
4688 response.type = NSCTL_RES_ERR;
4689 response.argc = 1;
4690 response.argv[0] = "error unpacking control packet";
4691 }
4692
4693 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
4694 if (!buf)
4695 {
4696 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
4697 return;
4698 }
4699
4700 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
4701 if (r > 0)
4702 {
4703 sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
4704 if (log_stream && config->debug >= 4)
4705 {
4706 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4707 dump_control(&response, log_stream);
4708 }
4709 }
4710 else
4711 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
4712 fmtaddr(addr->sin_addr.s_addr, 0), r);
4713
4714 free(buf);
4715 }
4716
4717 static tunnelidt new_tunnel()
4718 {
4719 tunnelidt i;
4720 for (i = 1; i < MAXTUNNEL; i++)
4721 {
4722 if (tunnel[i].state == TUNNELFREE)
4723 {
4724 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
4725 if (i > config->cluster_highest_tunnelid)
4726 config->cluster_highest_tunnelid = i;
4727 return i;
4728 }
4729 }
4730 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
4731 return 0;
4732 }
4733
4734 //
4735 // We're becoming the master. Do any required setup..
4736 //
4737 // This is principally telling all the plugins that we're
4738 // now a master, and telling them about all the sessions
4739 // that are active too..
4740 //
4741 void become_master(void)
4742 {
4743 int s, i;
4744 run_plugins(PLUGIN_BECOME_MASTER, NULL);
4745
4746 // running a bunch of iptables commands is slow and can cause
4747 // the master to drop tunnels on takeover--kludge around the
4748 // problem by forking for the moment (note: race)
4749 if (!fork_and_close())
4750 {
4751 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4752 {
4753 if (!session[s].opened) // Not an in-use session.
4754 continue;
4755
4756 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
4757 }
4758 exit(0);
4759 }
4760
4761 // add radius fds
4762 for (i = 0; i < config->num_radfds; i++)
4763 {
4764 FD_SET(radfds[i], &readset);
4765 if (radfds[i] > readset_n)
4766 readset_n = radfds[i];
4767 }
4768 }
4769
4770 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
4771 {
4772 int s, i;
4773 int count = 0;
4774 int buckets[64];
4775
4776 if (CLI_HELP_REQUESTED)
4777 return CLI_HELP_NO_ARGS;
4778
4779 time(&time_now);
4780 for (i = 0; i < 64;++i) buckets[i] = 0;
4781
4782 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4783 {
4784 int idle;
4785 if (!session[s].opened)
4786 continue;
4787
4788 idle = time_now - session[s].last_packet;
4789 idle /= 5 ; // In multiples of 5 seconds.
4790 if (idle < 0)
4791 idle = 0;
4792 if (idle > 63)
4793 idle = 63;
4794
4795 ++count;
4796 ++buckets[idle];
4797 }
4798
4799 for (i = 0; i < 63; ++i)
4800 {
4801 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
4802 }
4803 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
4804 cli_print(cli, "%d total sessions open.", count);
4805 return CLI_OK;
4806 }
4807
4808 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
4809 {
4810 int s, i;
4811 int count = 0;
4812 int buckets[64];
4813
4814 if (CLI_HELP_REQUESTED)
4815 return CLI_HELP_NO_ARGS;
4816
4817 time(&time_now);
4818 for (i = 0; i < 64;++i) buckets[i] = 0;
4819
4820 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4821 {
4822 int open = 0, d;
4823 if (!session[s].opened)
4824 continue;
4825
4826 d = time_now - session[s].opened;
4827 if (d < 0)
4828 d = 0;
4829 while (d > 1 && open < 32)
4830 {
4831 ++open;
4832 d >>= 1; // half.
4833 }
4834 ++count;
4835 ++buckets[open];
4836 }
4837
4838 s = 1;
4839 for (i = 0; i < 30; ++i)
4840 {
4841 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
4842 s <<= 1;
4843 }
4844 cli_print(cli, "%d total sessions open.", count);
4845 return CLI_OK;
4846 }
4847
4848 /* Unhide an avp.
4849 *
4850 * This unencodes the AVP using the L2TP secret and the previously
4851 * stored random vector. It overwrites the hidden data with the
4852 * unhidden AVP subformat.
4853 */
4854 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
4855 {
4856 MD5_CTX ctx;
4857 uint8_t digest[16];
4858 uint8_t *last;
4859 size_t d = 0;
4860
4861 // Compute initial pad
4862 MD5Init(&ctx);
4863 MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
4864 MD5Update(&ctx, (uint8_t) type & 0xff, 1);
4865 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4866 MD5Update(&ctx, vector, vec_len);
4867 MD5Final(digest, &ctx);
4868
4869 // pointer to last decoded 16 octets
4870 last = value;
4871
4872 while (len > 0)
4873 {
4874 // calculate a new pad based on the last decoded block
4875 if (d >= sizeof(digest))
4876 {
4877 MD5Init(&ctx);
4878 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4879 MD5Update(&ctx, last, sizeof(digest));
4880 MD5Final(digest, &ctx);
4881
4882 d = 0;
4883 last = value;
4884 }
4885
4886 *value++ ^= digest[d++];
4887 len--;
4888 }
4889 }
4890
4891 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
4892 {
4893 switch (p->op)
4894 {
4895 case FILTER_PORT_OP_EQ: return port == p->port;
4896 case FILTER_PORT_OP_NEQ: return port != p->port;
4897 case FILTER_PORT_OP_GT: return port > p->port;
4898 case FILTER_PORT_OP_LT: return port < p->port;
4899 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
4900 }
4901
4902 return 0;
4903 }
4904
4905 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
4906 {
4907 switch (op)
4908 {
4909 case FILTER_FLAG_OP_ANY:
4910 return (flags & sflags) || (~flags & cflags);
4911
4912 case FILTER_FLAG_OP_ALL:
4913 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
4914
4915 case FILTER_FLAG_OP_EST:
4916 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
4917 }
4918
4919 return 0;
4920 }
4921
4922 int ip_filter(uint8_t *buf, int len, uint8_t filter)
4923 {
4924 uint16_t frag_offset;
4925 uint8_t proto;
4926 in_addr_t src_ip;
4927 in_addr_t dst_ip;
4928 uint16_t src_port = 0;
4929 uint16_t dst_port = 0;
4930 uint8_t flags = 0;
4931 ip_filter_rulet *rule;
4932
4933 if (len < 20) // up to end of destination address
4934 return 0;
4935
4936 if ((*buf >> 4) != 4) // IPv4
4937 return 0;
4938
4939 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
4940 proto = buf[9];
4941 src_ip = *(in_addr_t *) (buf + 12);
4942 dst_ip = *(in_addr_t *) (buf + 16);
4943
4944 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
4945 {
4946 int l = (buf[0] & 0xf) * 4; // length of IP header
4947 if (len < l + 4) // ports
4948 return 0;
4949
4950 src_port = ntohs(*(uint16_t *) (buf + l));
4951 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
4952 if (proto == IPPROTO_TCP)
4953 {
4954 if (len < l + 14) // flags
4955 return 0;
4956
4957 flags = buf[l + 13] & 0x3f;
4958 }
4959 }
4960
4961 for (rule = ip_filters[filter].rules; rule->action; rule++)
4962 {
4963 if (rule->proto != IPPROTO_IP && proto != rule->proto)
4964 continue;
4965
4966 if (rule->src_wild != INADDR_BROADCAST &&
4967 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
4968 continue;
4969
4970 if (rule->dst_wild != INADDR_BROADCAST &&
4971 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
4972 continue;
4973
4974 if (frag_offset)
4975 {
4976 if (!rule->frag || rule->action == FILTER_ACTION_DENY)
4977 continue;
4978 }
4979 else
4980 {
4981 if (rule->frag)
4982 continue;
4983
4984 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
4985 {
4986 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
4987 continue;
4988
4989 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
4990 continue;
4991
4992 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
4993 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
4994 continue;
4995 }
4996 }
4997
4998 // matched
4999 rule->counter++;
5000 return rule->action == FILTER_ACTION_PERMIT;
5001 }
5002
5003 // default deny
5004 return 0;
5005 }