more state_state removal
[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 1.89 2005/04/01 06:39:00 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 uint32_t sessionid = 0; // session id for radius accounting
72 static int syslog_log = 0; // are we logging to syslog
73 static FILE *log_stream = NULL; // file handle for direct logging (i.e. direct into file, not via syslog).
74 extern int cluster_sockfd; // Intra-cluster communications socket.
75 uint32_t last_id = 0; // Last used PPP SID. Can I kill this?? -- mo
76
77 struct cli_session_actions *cli_session_actions = NULL; // Pending session changes requested by CLI
78 struct cli_tunnel_actions *cli_tunnel_actions = NULL; // Pending tunnel changes required by CLI
79
80 static void *ip_hash[256]; // Mapping from IP address to session structures.
81 struct ipv6radix {
82 int sess;
83 struct ipv6radix *branch;
84 } ipv6_hash[256]; // Mapping from IPv6 address to session structures.
85
86 // Traffic counters.
87 static uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
88 static uint32_t eth_rx = 0, eth_rx_pkt = 0;
89 uint32_t eth_tx = 0;
90
91 static uint32_t ip_pool_size = 1; // Size of the pool of addresses used for dynamic address allocation.
92 time_t time_now = 0; // Current time in seconds since epoch.
93 static char time_now_string[64] = {0}; // Current time as a string.
94 static char main_quit = 0; // True if we're in the process of exiting.
95 linked_list *loaded_plugins;
96 linked_list *plugins[MAX_PLUGIN_TYPES];
97
98 #define membersize(STRUCT, MEMBER) sizeof(((STRUCT *)0)->MEMBER)
99 #define CONFIG(NAME, MEMBER, TYPE) { NAME, offsetof(configt, MEMBER), membersize(configt, MEMBER), TYPE }
100
101 config_descriptt config_values[] = {
102 CONFIG("debug", debug, INT),
103 CONFIG("log_file", log_filename, STRING),
104 CONFIG("pid_file", pid_file, STRING),
105 CONFIG("random_device", random_device, STRING),
106 CONFIG("l2tp_secret", l2tpsecret, STRING),
107 CONFIG("primary_dns", default_dns1, IPv4),
108 CONFIG("secondary_dns", default_dns2, IPv4),
109 CONFIG("primary_radius", radiusserver[0], IPv4),
110 CONFIG("secondary_radius", radiusserver[1], IPv4),
111 CONFIG("primary_radius_port", radiusport[0], SHORT),
112 CONFIG("secondary_radius_port", radiusport[1], SHORT),
113 CONFIG("radius_accounting", radius_accounting, BOOL),
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 = session[s].radius;
1460 if (!r)
1461 {
1462 if (!(r = radiusnew(s)))
1463 {
1464 LOG(1, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
1465 STAT(radius_overflow);
1466 }
1467 else
1468 {
1469 random_data(radius[r].auth, sizeof(radius[r].auth));
1470 }
1471 }
1472
1473 if (r && radius[r].state != RADIUSSTOP)
1474 radiussend(r, RADIUSSTOP); // stop, if not already trying
1475
1476 // Save counters to dump to accounting file
1477 if (*config->accounting_dir && shut_acct_n < sizeof(shut_acct) / sizeof(*shut_acct))
1478 memcpy(&shut_acct[shut_acct_n++], &session[s], sizeof(session[s]));
1479 }
1480
1481 if (session[s].ip)
1482 { // IP allocated, clear and unroute
1483 int r;
1484 int routed = 0;
1485 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
1486 {
1487 if ((session[s].ip & session[s].route[r].mask) ==
1488 (session[s].route[r].ip & session[s].route[r].mask))
1489 routed++;
1490
1491 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 0);
1492 session[s].route[r].ip = 0;
1493 }
1494
1495 if (session[s].ip_pool_index == -1) // static ip
1496 {
1497 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
1498 session[s].ip = 0;
1499 }
1500 else
1501 free_ip_address(s);
1502
1503 // unroute IPv6, if setup
1504 if (session[s].flags & SF_IPV6_ROUTED)
1505 route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
1506 }
1507
1508 if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
1509 throttle_session(s, 0, 0);
1510
1511 if (result)
1512 { // Send CDN
1513 controlt *c = controlnew(14); // sending CDN
1514 if (error)
1515 {
1516 char buf[4];
1517 *(uint16_t *) buf = htons(result);
1518 *(uint16_t *) (buf+2) = htons(error);
1519 controlb(c, 1, buf, 4, 1);
1520 }
1521 else
1522 control16(c, 1, result, 1);
1523
1524 control16(c, 14, s, 1); // assigned session (our end)
1525 controladd(c, session[s].tunnel, s); // send the message
1526 }
1527
1528 if (!session[s].die)
1529 session[s].die = TIME + 150; // Clean up in 15 seconds
1530
1531 // update filter refcounts
1532 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1533 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1534
1535 cluster_send_session(s);
1536 }
1537
1538 void sendipcp(tunnelidt t, sessionidt s)
1539 {
1540 uint8_t buf[MAXCONTROL];
1541 uint16_t r = session[s].radius;
1542 uint8_t *q;
1543
1544 CSTAT(sendipcp);
1545
1546 if (!r)
1547 r = radiusnew(s);
1548
1549 if (radius[r].state != RADIUSIPCP)
1550 {
1551 radius[r].state = RADIUSIPCP;
1552 radius[r].try = 0;
1553 }
1554
1555 radius[r].retry = backoff(radius[r].try++);
1556 if (radius[r].try > 10)
1557 {
1558 radiusclear(r, s); // Clear radius session.
1559 sessionshutdown(s, "No reply on IPCP", 3, 0);
1560 return;
1561 }
1562
1563 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
1564 if (!q) return;
1565
1566 *q = ConfigReq;
1567 q[1] = r << RADIUS_SHIFT; // ID, dont care, we only send one type of request
1568 *(uint16_t *) (q + 2) = htons(10);
1569 q[4] = 3;
1570 q[5] = 6;
1571 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1572 config->bind_address ? config->bind_address :
1573 my_address; // send my IP
1574
1575 tunnelsend(buf, 10 + (q - buf), t); // send it
1576 session[s].flags &= ~SF_IPCP_ACKED; // Clear flag.
1577
1578 // If we have an IPv6 prefix length configured, assume we should
1579 // try to negotiate an IPv6 session as well. Unless we've had a
1580 // (N)ACK for IPV6CP.
1581 if (config->ipv6_prefix.s6_addr[0] > 0 &&
1582 !(session[s].flags & SF_IPV6CP_ACKED) &&
1583 !(session[s].flags & SF_IPV6_NACKED))
1584 {
1585 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
1586 if (!q) return;
1587
1588 *q = ConfigReq;
1589 q[1] = r << RADIUS_SHIFT; // ID, don't care, we
1590 // only send one type
1591 // of request
1592 *(uint16_t *) (q + 2) = htons(14);
1593 q[4] = 1;
1594 q[5] = 10;
1595 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1596 *(uint32_t *) (q + 10) = 0;
1597 q[13] = 1;
1598
1599 tunnelsend(buf, 14 + (q - buf), t); // send it
1600 }
1601 }
1602
1603 // kill a session now
1604 void sessionkill(sessionidt s, char *reason)
1605 {
1606
1607 CSTAT(sessionkill);
1608
1609 if (!session[s].opened) // not alive
1610 return;
1611
1612 if (session[s].next)
1613 {
1614 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1615 return;
1616 }
1617
1618 session[s].die = TIME;
1619 sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
1620 if (session[s].radius)
1621 radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
1622
1623 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1624
1625 memset(&session[s], 0, sizeof(session[s]));
1626 session[s].tunnel = T_FREE; // Mark it as free.
1627 session[s].next = sessionfree;
1628 sessionfree = s;
1629 cli_session_actions[s].action = 0;
1630 cluster_send_session(s);
1631 }
1632
1633 static void tunnelclear(tunnelidt t)
1634 {
1635 if (!t) return;
1636 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1637 tunnel[t].state = TUNNELFREE;
1638 }
1639
1640 // kill a tunnel now
1641 static void tunnelkill(tunnelidt t, char *reason)
1642 {
1643 sessionidt s;
1644 controlt *c;
1645
1646 CSTAT(tunnelkill);
1647
1648 tunnel[t].state = TUNNELDIE;
1649
1650 // free control messages
1651 while ((c = tunnel[t].controls))
1652 {
1653 controlt * n = c->next;
1654 tunnel[t].controls = n;
1655 tunnel[t].controlc--;
1656 c->next = controlfree;
1657 controlfree = c;
1658 }
1659 // kill sessions
1660 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1661 if (session[s].tunnel == t)
1662 sessionkill(s, reason);
1663
1664 // free tunnel
1665 tunnelclear(t);
1666 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1667 cli_tunnel_actions[t].action = 0;
1668 cluster_send_tunnel(t);
1669 }
1670
1671 // shut down a tunnel cleanly
1672 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1673 {
1674 sessionidt s;
1675
1676 CSTAT(tunnelshutdown);
1677
1678 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1679 {
1680 // never set up, can immediately kill
1681 tunnelkill(t, reason);
1682 return;
1683 }
1684 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1685
1686 // close session
1687 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1688 if (session[s].tunnel == t)
1689 sessionshutdown(s, reason, 3, 0);
1690
1691 tunnel[t].state = TUNNELDIE;
1692 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1693 cluster_send_tunnel(t);
1694 // TBA - should we wait for sessions to stop?
1695 if (result)
1696 {
1697 controlt *c = controlnew(4); // sending StopCCN
1698 if (error)
1699 {
1700 char buf[64];
1701 int l = 4;
1702 *(uint16_t *) buf = htons(result);
1703 *(uint16_t *) (buf+2) = htons(error);
1704 if (msg)
1705 {
1706 int m = strlen(msg);
1707 if (m + 4 > sizeof(buf))
1708 m = sizeof(buf) - 4;
1709
1710 memcpy(buf+4, msg, m);
1711 l += m;
1712 }
1713
1714 controlb(c, 1, buf, l, 1);
1715 }
1716 else
1717 control16(c, 1, result, 1);
1718
1719 control16(c, 9, t, 1); // assigned tunnel (our end)
1720 controladd(c, t, 0); // send the message
1721 }
1722 }
1723
1724 // read and process packet on tunnel (UDP)
1725 void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
1726 {
1727 char *chapresponse = NULL;
1728 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1729 uint8_t *p = buf + 2;
1730
1731
1732 CSTAT(processudp);
1733
1734 udp_rx += len;
1735 udp_rx_pkt++;
1736 LOG_HEX(5, "UDP Data", buf, len);
1737 STAT(tunnel_rx_packets);
1738 INC_STAT(tunnel_rx_bytes, len);
1739 if (len < 6)
1740 {
1741 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1742 STAT(tunnel_rx_errors);
1743 return;
1744 }
1745 if ((buf[1] & 0x0F) != 2)
1746 {
1747 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1748 STAT(tunnel_rx_errors);
1749 return;
1750 }
1751 if (*buf & 0x40)
1752 { // length
1753 l = ntohs(*(uint16_t *) p);
1754 p += 2;
1755 }
1756 t = ntohs(*(uint16_t *) p);
1757 p += 2;
1758 s = ntohs(*(uint16_t *) p);
1759 p += 2;
1760 if (s >= MAXSESSION)
1761 {
1762 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1763 STAT(tunnel_rx_errors);
1764 return;
1765 }
1766 if (t >= MAXTUNNEL)
1767 {
1768 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1769 STAT(tunnel_rx_errors);
1770 return;
1771 }
1772 if (*buf & 0x08)
1773 { // ns/nr
1774 ns = ntohs(*(uint16_t *) p);
1775 p += 2;
1776 nr = ntohs(*(uint16_t *) p);
1777 p += 2;
1778 }
1779 if (*buf & 0x02)
1780 { // offset
1781 uint16_t o = ntohs(*(uint16_t *) p);
1782 p += o + 2;
1783 }
1784 if ((p - buf) > l)
1785 {
1786 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1787 STAT(tunnel_rx_errors);
1788 return;
1789 }
1790 l -= (p - buf);
1791 if (*buf & 0x80)
1792 { // control
1793 uint16_t message = 0xFFFF; // message type
1794 uint8_t fatal = 0;
1795 uint8_t mandatory = 0;
1796 uint8_t chap = 0; // if CHAP being used
1797 uint16_t asession = 0; // assigned session
1798 uint32_t amagic = 0; // magic number
1799 uint8_t aflags = 0; // flags from last LCF
1800 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1801 int requestchap = 0; // do we request PAP instead of original CHAP request?
1802 char called[MAXTEL] = ""; // called number
1803 char calling[MAXTEL] = ""; // calling number
1804
1805 if (!config->cluster_iam_master)
1806 {
1807 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1808 return;
1809 }
1810
1811 // control messages must have bits 0x80|0x40|0x08
1812 // (type, length and sequence) set, and bits 0x02|0x01
1813 // (offset and priority) clear
1814 if ((*buf & 0xCB) != 0xC8)
1815 {
1816 LOG(1, s, t, "Bad control header %02X\n", *buf);
1817 STAT(tunnel_rx_errors);
1818 return;
1819 }
1820
1821 // check for duplicate tunnel open message
1822 if (!t && ns == 0)
1823 {
1824 int i;
1825
1826 //
1827 // Is this a duplicate of the first packet? (SCCRQ)
1828 //
1829 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1830 {
1831 if (tunnel[i].state != TUNNELOPENING ||
1832 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1833 tunnel[i].port != ntohs(addr->sin_port) )
1834 continue;
1835 t = i;
1836 LOG(3, s, t, "Duplicate SCCRQ?\n");
1837 break;
1838 }
1839 }
1840
1841 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1842 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1843
1844 // if no tunnel specified, assign one
1845 if (!t)
1846 {
1847 if (!(t = new_tunnel()))
1848 {
1849 LOG(1, 0, 0, "No more tunnels\n");
1850 STAT(tunnel_overflow);
1851 return;
1852 }
1853 tunnelclear(t);
1854 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1855 tunnel[t].port = ntohs(addr->sin_port);
1856 tunnel[t].window = 4; // default window
1857 STAT(tunnel_created);
1858 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1859 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1860 }
1861
1862 // If the 'ns' just received is not the 'nr' we're
1863 // expecting, just send an ack and drop it.
1864 //
1865 // if 'ns' is less, then we got a retransmitted packet.
1866 // if 'ns' is greater than missed a packet. Either way
1867 // we should ignore it.
1868 if (ns != tunnel[t].nr)
1869 {
1870 // is this the sequence we were expecting?
1871 STAT(tunnel_rx_errors);
1872 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
1873 t, ns, tunnel[t].nr);
1874
1875 if (l) // Is this not a ZLB?
1876 controlnull(t);
1877 return;
1878 }
1879
1880 // This is used to time out old tunnels
1881 tunnel[t].lastrec = time_now;
1882
1883 // check sequence of this message
1884 {
1885 int skip = tunnel[t].window; // track how many in-window packets are still in queue
1886 // some to clear maybe?
1887 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
1888 {
1889 controlt *c = tunnel[t].controls;
1890 tunnel[t].controls = c->next;
1891 tunnel[t].controlc--;
1892 c->next = controlfree;
1893 controlfree = c;
1894 skip--;
1895 tunnel[t].try = 0; // we have progress
1896 }
1897
1898 // receiver advance (do here so quoted correctly in any sends below)
1899 if (l) tunnel[t].nr = (ns + 1);
1900 if (skip < 0) skip = 0;
1901 if (skip < tunnel[t].controlc)
1902 {
1903 // some control packets can now be sent that were previous stuck out of window
1904 int tosend = tunnel[t].window - skip;
1905 controlt *c = tunnel[t].controls;
1906 while (c && skip)
1907 {
1908 c = c->next;
1909 skip--;
1910 }
1911 while (c && tosend)
1912 {
1913 tunnel[t].try = 0; // first send
1914 tunnelsend(c->buf, c->length, t);
1915 c = c->next;
1916 tosend--;
1917 }
1918 }
1919 if (!tunnel[t].controlc)
1920 tunnel[t].retry = 0; // caught up
1921 }
1922 if (l)
1923 { // if not a null message
1924 int result = 0;
1925 int error = 0;
1926 char *msg = 0;
1927
1928 // process AVPs
1929 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
1930 {
1931 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
1932 uint8_t *b = p;
1933 uint8_t flags = *p;
1934 uint16_t mtype;
1935 if (n > l)
1936 {
1937 LOG(1, s, t, "Invalid length in AVP\n");
1938 STAT(tunnel_rx_errors);
1939 return;
1940 }
1941 p += n; // next
1942 l -= n;
1943 if (flags & 0x3C) // reserved bits, should be clear
1944 {
1945 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
1946 fatal = flags;
1947 result = 2; // general error
1948 error = 3; // reserved field non-zero
1949 msg = 0;
1950 continue; // next
1951 }
1952 b += 2;
1953 if (*(uint16_t *) (b))
1954 {
1955 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
1956 fatal = flags;
1957 result = 2; // general error
1958 error = 6; // generic vendor-specific error
1959 msg = "unsupported vendor-specific";
1960 continue; // next
1961 }
1962 b += 2;
1963 mtype = ntohs(*(uint16_t *) (b));
1964 b += 2;
1965 n -= 6;
1966
1967 if (flags & 0x40)
1968 {
1969 uint16_t orig_len;
1970
1971 // handle hidden AVPs
1972 if (!*config->l2tpsecret)
1973 {
1974 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
1975 fatal = flags;
1976 result = 2; // general error
1977 error = 6; // generic vendor-specific error
1978 msg = "secret not specified";
1979 continue;
1980 }
1981 if (!session[s].random_vector_length)
1982 {
1983 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
1984 fatal = flags;
1985 result = 2; // general error
1986 error = 6; // generic
1987 msg = "no random vector";
1988 continue;
1989 }
1990 if (n < 8)
1991 {
1992 LOG(2, s, t, "Short hidden AVP.\n");
1993 fatal = flags;
1994 result = 2; // general error
1995 error = 2; // length is wrong
1996 msg = 0;
1997 continue;
1998 }
1999
2000 LOG(4, s, t, "Hidden AVP\n");
2001
2002 // Unhide the AVP
2003 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
2004
2005 orig_len = ntohs(*(uint16_t *) b);
2006 if (orig_len > n + 2)
2007 {
2008 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
2009 orig_len, n);
2010
2011 fatal = flags;
2012 result = 2; // general error
2013 error = 2; // length is wrong
2014 msg = 0;
2015 continue;
2016 }
2017
2018 b += 2;
2019 n = orig_len;
2020 }
2021
2022 LOG(4, s, t, " AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
2023 switch (mtype)
2024 {
2025 case 0: // message type
2026 message = ntohs(*(uint16_t *) b);
2027 mandatory = flags & 0x80;
2028 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_message_type(message));
2029 break;
2030 case 1: // result code
2031 {
2032 uint16_t rescode = ntohs(*(uint16_t *) b);
2033 const char* resdesc = "(unknown)";
2034 if (message == 4)
2035 { /* StopCCN */
2036 resdesc = stopccn_result_code(rescode);
2037 }
2038 else if (message == 14)
2039 { /* CDN */
2040 resdesc = cdn_result_code(rescode);
2041 }
2042
2043 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2044 if (n >= 4)
2045 {
2046 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2047 LOG(4, s, t, " Error Code %d: %s\n", errcode, error_code(errcode));
2048 }
2049 if (n > 4)
2050 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2051
2052 break;
2053 }
2054 break;
2055 case 2: // protocol version
2056 {
2057 version = ntohs(*(uint16_t *) (b));
2058 LOG(4, s, t, " Protocol version = %d\n", version);
2059 if (version && version != 0x0100)
2060 { // allow 0.0 and 1.0
2061 LOG(1, s, t, " Bad protocol version %04X\n", version);
2062 fatal = flags;
2063 result = 5; // unspported protocol version
2064 error = 0x0100; // supported version
2065 msg = 0;
2066 continue; // next
2067 }
2068 }
2069 break;
2070 case 3: // framing capabilities
2071 // LOG(4, s, t, "Framing capabilities\n");
2072 break;
2073 case 4: // bearer capabilities
2074 // LOG(4, s, t, "Bearer capabilities\n");
2075 break;
2076 case 5: // tie breaker
2077 // We never open tunnels, so we don't care about tie breakers
2078 // LOG(4, s, t, "Tie breaker\n");
2079 continue;
2080 case 6: // firmware revision
2081 // LOG(4, s, t, "Firmware revision\n");
2082 break;
2083 case 7: // host name
2084 memset(tunnel[t].hostname, 0, 128);
2085 memcpy(tunnel[t].hostname, b, (n >= 127) ? 127 : n);
2086 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2087 // TBA - to send to RADIUS
2088 break;
2089 case 8: // vendor name
2090 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2091 memcpy(tunnel[t].vendor, b, (n >= sizeof(tunnel[t].vendor) - 1) ? sizeof(tunnel[t].vendor) - 1 : n);
2092 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2093 break;
2094 case 9: // assigned tunnel
2095 tunnel[t].far = ntohs(*(uint16_t *) (b));
2096 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2097 break;
2098 case 10: // rx window
2099 tunnel[t].window = ntohs(*(uint16_t *) (b));
2100 if (!tunnel[t].window)
2101 tunnel[t].window = 1; // window of 0 is silly
2102 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2103 break;
2104 case 11: // Challenge
2105 {
2106 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2107 build_chap_response(b, 2, n, &chapresponse);
2108 }
2109 break;
2110 case 13: // Response
2111 // Why did they send a response? We never challenge.
2112 LOG(2, s, t, " received unexpected challenge response\n");
2113 break;
2114
2115 case 14: // assigned session
2116 asession = session[s].far = ntohs(*(uint16_t *) (b));
2117 LOG(4, s, t, " assigned session = %d\n", asession);
2118 break;
2119 case 15: // call serial number
2120 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2121 break;
2122 case 18: // bearer type
2123 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2124 // TBA - for RADIUS
2125 break;
2126 case 19: // framing type
2127 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2128 // TBA
2129 break;
2130 case 21: // called number
2131 memset(called, 0, MAXTEL);
2132 memcpy(called, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
2133 LOG(4, s, t, " Called <%s>\n", called);
2134 break;
2135 case 22: // calling number
2136 memset(calling, 0, MAXTEL);
2137 memcpy(calling, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
2138 LOG(4, s, t, " Calling <%s>\n", calling);
2139 break;
2140 case 23: // subtype
2141 break;
2142 case 24: // tx connect speed
2143 if (n == 4)
2144 {
2145 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2146 }
2147 else
2148 {
2149 // AS5300s send connect speed as a string
2150 char tmp[30] = {0};
2151 memcpy(tmp, b, (n >= 30) ? 30 : n);
2152 session[s].tx_connect_speed = atol(tmp);
2153 }
2154 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2155 break;
2156 case 38: // rx connect speed
2157 if (n == 4)
2158 {
2159 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2160 }
2161 else
2162 {
2163 // AS5300s send connect speed as a string
2164 char tmp[30] = {0};
2165 memcpy(tmp, b, (n >= 30) ? 30 : n);
2166 session[s].rx_connect_speed = atol(tmp);
2167 }
2168 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2169 break;
2170 case 25: // Physical Channel ID
2171 {
2172 uint32_t tmp = ntohl(*(uint32_t *) b);
2173 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2174 break;
2175 }
2176 case 29: // Proxy Authentication Type
2177 {
2178 uint16_t atype = ntohs(*(uint16_t *)b);
2179 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, auth_type(atype));
2180 requestchap = (atype == 2);
2181 break;
2182 }
2183 case 30: // Proxy Authentication Name
2184 {
2185 char authname[64] = {0};
2186 memcpy(authname, b, (n > 63) ? 63 : n);
2187 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2188 authname);
2189 break;
2190 }
2191 case 31: // Proxy Authentication Challenge
2192 {
2193 memcpy(radius[session[s].radius].auth, b, 16);
2194 LOG(4, s, t, " Proxy Auth Challenge\n");
2195 break;
2196 }
2197 case 32: // Proxy Authentication ID
2198 {
2199 uint16_t authid = ntohs(*(uint16_t *)(b));
2200 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2201 if (session[s].radius)
2202 radius[session[s].radius].id = authid;
2203 break;
2204 }
2205 case 33: // Proxy Authentication Response
2206 {
2207 char authresp[64] = {0};
2208 memcpy(authresp, b, (n > 63) ? 63 : n);
2209 LOG(4, s, t, " Proxy Auth Response\n");
2210 break;
2211 }
2212 case 27: // last send lcp
2213 { // find magic number
2214 uint8_t *p = b, *e = p + n;
2215 while (p + 1 < e && p[1] && p + p[1] <= e)
2216 {
2217 if (*p == 5 && p[1] == 6) // Magic-Number
2218 amagic = ntohl(*(uint32_t *) (p + 2));
2219 else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol
2220 chap = 1;
2221 else if (*p == 7) // Protocol-Field-Compression
2222 aflags |= SESSIONPFC;
2223 else if (*p == 8) // Address-and-Control-Field-Compression
2224 aflags |= SESSIONACFC;
2225 p += p[1];
2226 }
2227 }
2228 break;
2229 case 28: // last recv lcp confreq
2230 break;
2231 case 26: // Initial Received LCP CONFREQ
2232 break;
2233 case 39: // seq required - we control it as an LNS anyway...
2234 break;
2235 case 36: // Random Vector
2236 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2237 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2238 memcpy(session[s].random_vector, b, n);
2239 session[s].random_vector_length = n;
2240 break;
2241 default:
2242 {
2243 static char e[] = "unknown AVP 0xXXXX";
2244 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2245 fatal = flags;
2246 result = 2; // general error
2247 error = 8; // unknown mandatory AVP
2248 sprintf((msg = e) + 14, "%04x", mtype);
2249 continue; // next
2250 }
2251 }
2252 }
2253 // process message
2254 if (fatal & 0x80)
2255 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2256 else
2257 switch (message)
2258 {
2259 case 1: // SCCRQ - Start Control Connection Request
2260 {
2261 controlt *c = controlnew(2); // sending SCCRP
2262 control16(c, 2, version, 1); // protocol version
2263 control32(c, 3, 3, 1); // framing
2264 controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
2265 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2266 control16(c, 9, t, 1); // assigned tunnel
2267 controladd(c, t, s); // send the resply
2268 }
2269 tunnel[t].state = TUNNELOPENING;
2270 break;
2271 case 2: // SCCRP
2272 tunnel[t].state = TUNNELOPEN;
2273 break;
2274 case 3: // SCCN
2275 tunnel[t].state = TUNNELOPEN;
2276 controlnull(t); // ack
2277 break;
2278 case 4: // StopCCN
2279 controlnull(t); // ack
2280 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2281 break;
2282 case 6: // HELLO
2283 controlnull(t); // simply ACK
2284 break;
2285 case 7: // OCRQ
2286 // TBA
2287 break;
2288 case 8: // OCRO
2289 // TBA
2290 break;
2291 case 9: // OCCN
2292 // TBA
2293 break;
2294 case 10: // ICRQ
2295 if (!sessionfree)
2296 {
2297 STAT(session_overflow);
2298 LOG(1, 0, t, "No free sessions");
2299 return;
2300 }
2301 else
2302 {
2303 uint16_t r;
2304 controlt *c;
2305
2306 s = sessionfree;
2307 sessionfree = session[s].next;
2308 memset(&session[s], 0, sizeof(session[s]));
2309
2310 if (s > config->cluster_highest_sessionid)
2311 config->cluster_highest_sessionid = s;
2312
2313 // make a RADIUS session
2314 if (!(r = radiusnew(s)))
2315 {
2316 LOG(1, s, t, "No free RADIUS sessions for ICRQ\n");
2317 sessionkill(s, "no free RADIUS sesions");
2318 return;
2319 }
2320
2321 c = controlnew(11); // sending ICRP
2322 session[s].id = sessionid++;
2323 session[s].opened = time_now;
2324 session[s].tunnel = t;
2325 session[s].far = asession;
2326 session[s].last_packet = time_now;
2327 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2328 control16(c, 14, s, 1); // assigned session
2329 controladd(c, t, s); // send the reply
2330
2331 // Generate a random challenge
2332 random_data(radius[r].auth, sizeof(radius[r].auth));
2333 strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
2334 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2335 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2336 STAT(session_created);
2337 }
2338 break;
2339 case 11: // ICRP
2340 // TBA
2341 break;
2342 case 12: // ICCN
2343 if (amagic == 0) amagic = time_now;
2344 session[s].magic = amagic; // set magic number
2345 session[s].l2tp_flags = aflags; // set flags received
2346 LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
2347 controlnull(t); // ack
2348 // In CHAP state, request PAP instead
2349 if (requestchap)
2350 initlcp(t, s);
2351 break;
2352 case 14: // CDN
2353 controlnull(t); // ack
2354 sessionshutdown(s, "Closed (Received CDN)", 0, 0);
2355 break;
2356 case 0xFFFF:
2357 LOG(1, s, t, "Missing message type\n");
2358 break;
2359 default:
2360 STAT(tunnel_rx_errors);
2361 if (mandatory)
2362 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2363 else
2364 LOG(1, s, t, "Unknown message type %d\n", message);
2365 break;
2366 }
2367 if (chapresponse) free(chapresponse);
2368 cluster_send_tunnel(t);
2369 }
2370 else
2371 {
2372 LOG(4, s, t, " Got a ZLB ack\n");
2373 }
2374 }
2375 else
2376 { // data
2377 uint16_t prot;
2378
2379 LOG_HEX(5, "Receive Tunnel Data", p, l);
2380 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2381 { // HDLC address header, discard
2382 p += 2;
2383 l -= 2;
2384 }
2385 if (l < 2)
2386 {
2387 LOG(1, s, t, "Short ppp length %d\n", l);
2388 STAT(tunnel_rx_errors);
2389 return;
2390 }
2391 if (*p & 1)
2392 {
2393 prot = *p++;
2394 l--;
2395 }
2396 else
2397 {
2398 prot = ntohs(*(uint16_t *) p);
2399 p += 2;
2400 l -= 2;
2401 }
2402
2403 if (s && !session[s].opened) // Is something wrong??
2404 {
2405 if (!config->cluster_iam_master)
2406 {
2407 // Pass it off to the master to deal with..
2408 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2409 return;
2410 }
2411
2412
2413 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2414 STAT(tunnel_rx_errors);
2415 return;
2416 }
2417
2418 if (prot == PPPPAP)
2419 {
2420 session[s].last_packet = time_now;
2421 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2422 processpap(t, s, p, l);
2423 }
2424 else if (prot == PPPCHAP)
2425 {
2426 session[s].last_packet = time_now;
2427 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2428 processchap(t, s, p, l);
2429 }
2430 else if (prot == PPPLCP)
2431 {
2432 session[s].last_packet = time_now;
2433 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2434 processlcp(t, s, p, l);
2435 }
2436 else if (prot == PPPIPCP)
2437 {
2438 session[s].last_packet = time_now;
2439 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2440 processipcp(t, s, p, l);
2441 }
2442 else if (prot == PPPIPV6CP)
2443 {
2444 if (config->ipv6_prefix.s6_addr[0] > 0)
2445 {
2446 session[s].last_packet = time_now;
2447 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2448 processipv6cp(t, s, p, l);
2449 }
2450 else
2451 {
2452 LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n");
2453 }
2454 }
2455 else if (prot == PPPCCP)
2456 {
2457 session[s].last_packet = time_now;
2458 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2459 processccp(t, s, p, l);
2460 }
2461 else if (prot == PPPIP)
2462 {
2463 if (session[s].die)
2464 {
2465 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2466 return; // closing session, PPP not processed
2467 }
2468
2469 session[s].last_packet = time_now;
2470 if (session[s].walled_garden && !config->cluster_iam_master)
2471 {
2472 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2473 return;
2474 }
2475
2476 processipin(t, s, p, l);
2477 }
2478 else if (prot == PPPIPV6)
2479 {
2480 if (!config->ipv6_prefix.s6_addr[0] > 0)
2481 {
2482 LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
2483 return;
2484 }
2485 if (session[s].die)
2486 {
2487 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2488 return; // closing session, PPP not processed
2489 }
2490
2491 session[s].last_packet = time_now;
2492 if (session[s].walled_garden && !config->cluster_iam_master)
2493 {
2494 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2495 return;
2496 }
2497
2498 processipv6in(t, s, p, l);
2499 }
2500 else
2501 {
2502 STAT(tunnel_rx_errors);
2503 LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
2504 }
2505 }
2506 }
2507
2508 // read and process packet on tun
2509 static void processtun(uint8_t * buf, int len)
2510 {
2511 LOG_HEX(5, "Receive TUN Data", buf, len);
2512 STAT(tun_rx_packets);
2513 INC_STAT(tun_rx_bytes, len);
2514
2515 CSTAT(processtun);
2516
2517 eth_rx_pkt++;
2518 eth_rx += len;
2519 if (len < 22)
2520 {
2521 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2522 STAT(tun_rx_errors);
2523 return;
2524 }
2525
2526 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2527 processipout(buf, len);
2528 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2529 && config->ipv6_prefix.s6_addr[0] > 0)
2530 processipv6out(buf, len);
2531
2532 // Else discard.
2533 }
2534
2535 //
2536 // Maximum number of actions to complete.
2537 // This is to avoid sending out too many packets
2538 // at once.
2539 #define MAX_ACTIONS 500
2540
2541 static int regular_cleanups(void)
2542 {
2543 static sessionidt s = 0; // Next session to check for actions on.
2544 tunnelidt t;
2545 int count=0,i;
2546 uint16_t r;
2547 static clockt next_acct = 0;
2548 static clockt next_shut_acct = 0;
2549 int a;
2550
2551 LOG(3, 0, 0, "Begin regular cleanup\n");
2552
2553 for (r = 1; r < MAXRADIUS; r++)
2554 {
2555 if (!radius[r].state)
2556 continue;
2557 if (radius[r].retry)
2558 {
2559 if (radius[r].retry <= TIME)
2560 radiusretry(r);
2561 } else
2562 radius[r].retry = backoff(radius[r].try+1); // Is this really needed? --mo
2563 }
2564 for (t = 1; t <= config->cluster_highest_tunnelid; t++)
2565 {
2566 // check for expired tunnels
2567 if (tunnel[t].die && tunnel[t].die <= TIME)
2568 {
2569 STAT(tunnel_timeout);
2570 tunnelkill(t, "Expired");
2571 continue;
2572 }
2573 // check for message resend
2574 if (tunnel[t].retry && tunnel[t].controlc)
2575 {
2576 // resend pending messages as timeout on reply
2577 if (tunnel[t].retry <= TIME)
2578 {
2579 controlt *c = tunnel[t].controls;
2580 uint8_t w = tunnel[t].window;
2581 tunnel[t].try++; // another try
2582 if (tunnel[t].try > 5)
2583 tunnelkill(t, "Timeout on control message"); // game over
2584 else
2585 while (c && w--)
2586 {
2587 tunnelsend(c->buf, c->length, t);
2588 c = c->next;
2589 }
2590 }
2591 }
2592 // Send hello
2593 if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < TIME + 600)
2594 {
2595 controlt *c = controlnew(6); // sending HELLO
2596 controladd(c, t, 0); // send the message
2597 LOG(3, 0, t, "Sending HELLO message\n");
2598 }
2599
2600 // Check for tunnel changes requested from the CLI
2601 if ((a = cli_tunnel_actions[t].action))
2602 {
2603 cli_tunnel_actions[t].action = 0;
2604 if (a & CLI_TUN_KILL)
2605 {
2606 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2607 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2608 }
2609 }
2610
2611 }
2612
2613 count = 0;
2614 for (i = 1; i <= config->cluster_highest_sessionid; i++)
2615 {
2616 s++;
2617 if (s > config->cluster_highest_sessionid)
2618 s = 1;
2619
2620 if (!session[s].opened) // Session isn't in use
2621 continue;
2622
2623 if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
2624 {
2625 // IPCP has not completed yet. Resend
2626 LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
2627 sendipcp(session[s].tunnel, s);
2628 }
2629
2630 // check for expired sessions
2631 if (session[s].die && session[s].die <= TIME)
2632 {
2633 sessionkill(s, "Expired");
2634 if (++count >= MAX_ACTIONS) break;
2635 continue;
2636 }
2637
2638 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2639 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2640 {
2641 sessionshutdown(s, "No response to LCP ECHO requests", 3, 0);
2642 STAT(session_timeout);
2643 if (++count >= MAX_ACTIONS) break;
2644 continue;
2645 }
2646
2647 // No data in ECHO_TIMEOUT seconds, send LCP ECHO
2648 if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
2649 {
2650 uint8_t b[MAXCONTROL] = {0};
2651
2652 uint8_t *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
2653 if (!q) continue;
2654
2655 *q = EchoReq;
2656 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2657 *(uint16_t *)(q + 2) = htons(8); // Length
2658 *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
2659
2660 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2661 (int)(time_now - session[s].last_packet));
2662 tunnelsend(b, 24, session[s].tunnel); // send it
2663 if (++count >= MAX_ACTIONS) break;
2664 }
2665
2666 // Check for actions requested from the CLI
2667 if ((a = cli_session_actions[s].action))
2668 {
2669 int send = 0;
2670
2671 cli_session_actions[s].action = 0;
2672 if (a & CLI_SESS_KILL)
2673 {
2674 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2675 sessionshutdown(s, "Requested by administrator", 3, 0);
2676 a = 0; // dead, no need to check for other actions
2677 }
2678
2679 if (a & CLI_SESS_NOSNOOP)
2680 {
2681 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2682 session[s].snoop_ip = 0;
2683 session[s].snoop_port = 0;
2684 send++;
2685 }
2686 else if (a & CLI_SESS_SNOOP)
2687 {
2688 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2689 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2690 cli_session_actions[s].snoop_port);
2691
2692 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2693 session[s].snoop_port = cli_session_actions[s].snoop_port;
2694 send++;
2695 }
2696
2697 if (a & CLI_SESS_NOTHROTTLE)
2698 {
2699 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2700 throttle_session(s, 0, 0);
2701 send++;
2702 }
2703 else if (a & CLI_SESS_THROTTLE)
2704 {
2705 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2706 cli_session_actions[s].throttle_in,
2707 cli_session_actions[s].throttle_out);
2708
2709 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
2710 send++;
2711 }
2712
2713 if (a & CLI_SESS_NOFILTER)
2714 {
2715 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
2716 filter_session(s, 0, 0);
2717 send++;
2718 }
2719 else if (a & CLI_SESS_FILTER)
2720 {
2721 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
2722 cli_session_actions[s].filter_in,
2723 cli_session_actions[s].filter_out);
2724
2725 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
2726 send++;
2727 }
2728
2729 if (send)
2730 cluster_send_session(s);
2731
2732 if (++count >= MAX_ACTIONS) break;
2733 }
2734 }
2735
2736 if (*config->accounting_dir)
2737 {
2738 if (next_acct <= TIME)
2739 {
2740 // Dump accounting data
2741 next_acct = TIME + ACCT_TIME;
2742 next_shut_acct = TIME + ACCT_SHUT_TIME;
2743 dump_acct_info(1);
2744 }
2745 else if (next_shut_acct <= TIME)
2746 {
2747 // Dump accounting data for shutdown sessions
2748 next_shut_acct = TIME + ACCT_SHUT_TIME;
2749 if (shut_acct_n)
2750 dump_acct_info(0);
2751 }
2752 }
2753
2754 if (count >= MAX_ACTIONS)
2755 return 1; // Didn't finish!
2756
2757 LOG(3, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
2758 return 0;
2759 }
2760
2761
2762 //
2763 // Are we in the middle of a tunnel update, or radius
2764 // requests??
2765 //
2766 static int still_busy(void)
2767 {
2768 int i;
2769 static clockt last_talked = 0;
2770 static clockt start_busy_wait = 0;
2771 if (start_busy_wait == 0)
2772 start_busy_wait = TIME;
2773
2774 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
2775 {
2776 if (!tunnel[i].controlc)
2777 continue;
2778
2779 if (last_talked != TIME)
2780 {
2781 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
2782 last_talked = TIME;
2783 }
2784 return 1;
2785 }
2786
2787 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
2788 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
2789 {
2790 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
2791 return 0;
2792 }
2793
2794 for (i = 1; i < MAXRADIUS; i++)
2795 {
2796 if (radius[i].state == RADIUSNULL)
2797 continue;
2798 if (radius[i].state == RADIUSWAIT)
2799 continue;
2800
2801 if (last_talked != TIME)
2802 {
2803 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
2804 last_talked = TIME;
2805 }
2806 return 1;
2807 }
2808
2809 return 0;
2810 }
2811
2812 static fd_set readset;
2813 static int readset_n = 0;
2814
2815 // main loop - gets packets on tun or udp and processes them
2816 static void mainloop(void)
2817 {
2818 int i;
2819 uint8_t buf[65536];
2820 struct timeval to;
2821 clockt next_cluster_ping = 0; // send initial ping immediately
2822 time_t next_clean = time_now + config->cleanup_interval;
2823
2824 LOG(4, 0, 0, "Beginning of main loop. udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
2825 udpfd, tunfd, cluster_sockfd, controlfd);
2826
2827 FD_ZERO(&readset);
2828 FD_SET(udpfd, &readset);
2829 FD_SET(tunfd, &readset);
2830 FD_SET(controlfd, &readset);
2831 FD_SET(clifd, &readset);
2832 if (cluster_sockfd) FD_SET(cluster_sockfd, &readset);
2833 readset_n = udpfd;
2834 if (tunfd > readset_n) readset_n = tunfd;
2835 if (controlfd > readset_n) readset_n = controlfd;
2836 if (clifd > readset_n) readset_n = clifd;
2837 if (cluster_sockfd > readset_n) readset_n = cluster_sockfd;
2838
2839 while (!main_quit || still_busy())
2840 {
2841 fd_set r;
2842 int n = readset_n;
2843 #ifdef BGP
2844 fd_set w;
2845 int bgp_set[BGP_NUM_PEERS];
2846 #endif /* BGP */
2847
2848 if (config->reload_config)
2849 {
2850 // Update the config state based on config settings
2851 update_config();
2852 }
2853
2854 memcpy(&r, &readset, sizeof(fd_set));
2855 to.tv_sec = 0;
2856 to.tv_usec = 100000; // 1/10th of a second.
2857
2858 #ifdef BGP
2859 FD_ZERO(&w);
2860 for (i = 0; i < BGP_NUM_PEERS; i++)
2861 {
2862 bgp_set[i] = bgp_select_state(&bgp_peers[i]);
2863 if (bgp_set[i] & 1)
2864 {
2865 FD_SET(bgp_peers[i].sock, &r);
2866 if (bgp_peers[i].sock > n)
2867 n = bgp_peers[i].sock;
2868 }
2869
2870 if (bgp_set[i] & 2)
2871 {
2872 FD_SET(bgp_peers[i].sock, &w);
2873 if (bgp_peers[i].sock > n)
2874 n = bgp_peers[i].sock;
2875 }
2876 }
2877
2878 n = select(n + 1, &r, &w, 0, &to);
2879 #else /* BGP */
2880 n = select(n + 1, &r, 0, 0, &to);
2881 #endif /* BGP */
2882
2883 STAT(select_called);
2884
2885 TIME = now();
2886 if (n < 0)
2887 {
2888 if (errno == EINTR ||
2889 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
2890 continue;
2891
2892 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
2893 main_quit++;
2894 break;
2895 }
2896 else if (n)
2897 {
2898 struct sockaddr_in addr;
2899 int alen, c, s;
2900 int udp_pkts = 0;
2901 int tun_pkts = 0;
2902 int cluster_pkts = 0;
2903
2904 // nsctl commands
2905 if (FD_ISSET(controlfd, &r))
2906 {
2907 alen = sizeof(addr);
2908 processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
2909 n--;
2910 }
2911
2912 // RADIUS responses
2913 if (config->cluster_iam_master)
2914 {
2915 for (i = 0; i < config->num_radfds; i++)
2916 {
2917 if (FD_ISSET(radfds[i], &r))
2918 {
2919 processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
2920 n--;
2921 }
2922 }
2923 }
2924
2925 // CLI connections
2926 if (FD_ISSET(clifd, &r))
2927 {
2928 int cli;
2929
2930 alen = sizeof(addr);
2931 if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
2932 {
2933 cli_do(cli);
2934 close(cli);
2935 }
2936 else
2937 LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
2938
2939 n--;
2940 }
2941
2942 #ifdef BGP
2943 for (i = 0; i < BGP_NUM_PEERS; i++)
2944 {
2945 int isr = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0;
2946 int isw = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0;
2947 bgp_process(&bgp_peers[i], isr, isw);
2948 if (isr) n--;
2949 if (isw) n--;
2950 }
2951 #endif /* BGP */
2952
2953 for (c = 0; n && c < config->multi_read_count; c++)
2954 {
2955 // L2TP
2956 if (FD_ISSET(udpfd, &r))
2957 {
2958 alen = sizeof(addr);
2959 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
2960 {
2961 processudp(buf, s, &addr);
2962 udp_pkts++;
2963 }
2964 else
2965 {
2966 FD_CLR(udpfd, &r);
2967 n--;
2968 }
2969 }
2970
2971 // incoming IP
2972 if (FD_ISSET(tunfd, &r))
2973 {
2974 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
2975 {
2976 processtun(buf, s);
2977 tun_pkts++;
2978 }
2979 else
2980 {
2981 FD_CLR(tunfd, &r);
2982 n--;
2983 }
2984 }
2985
2986 // cluster
2987 if (FD_ISSET(cluster_sockfd, &r))
2988 {
2989 alen = sizeof(addr);
2990 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
2991 {
2992 processcluster(buf, s, addr.sin_addr.s_addr);
2993 cluster_pkts++;
2994 }
2995 else
2996 {
2997 FD_CLR(cluster_sockfd, &r);
2998 n--;
2999 }
3000 }
3001 }
3002
3003 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
3004 STAT(multi_read_used);
3005
3006 if (c >= config->multi_read_count)
3007 {
3008 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
3009 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3010
3011 STAT(multi_read_exceeded);
3012 }
3013 }
3014
3015 // Runs on every machine (master and slaves).
3016 if (cluster_sockfd && next_cluster_ping <= TIME)
3017 {
3018 // Check to see which of the cluster is still alive..
3019
3020 cluster_send_ping(basetime); // Only does anything if we're a slave
3021 cluster_check_master(); // ditto.
3022
3023 cluster_heartbeat(); // Only does anything if we're a master.
3024 cluster_check_slaves(); // ditto.
3025
3026 master_update_counts(); // If we're a slave, send our byte counters to our master.
3027
3028 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3029 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3030 else
3031 next_cluster_ping = TIME + config->cluster_hb_interval;
3032 }
3033
3034 // Run token bucket filtering queue..
3035 // Only run it every 1/10th of a second.
3036 // Runs on all machines both master and slave.
3037 {
3038 static clockt last_run = 0;
3039 if (last_run != TIME)
3040 {
3041 last_run = TIME;
3042 tbf_run_timer();
3043 }
3044 }
3045
3046 /* Handle timeouts. Make sure that this gets run anyway, even if there was
3047 * something to read, else under load this will never actually run....
3048 *
3049 */
3050 if (config->cluster_iam_master && next_clean <= time_now)
3051 {
3052 if (regular_cleanups())
3053 {
3054 // Did it finish?
3055 next_clean = time_now + 1 ; // Didn't finish. Check quickly.
3056 }
3057 else
3058 {
3059 next_clean = time_now + config->cleanup_interval; // Did. Move to next interval.
3060 }
3061 }
3062 }
3063
3064 // Are we the master and shutting down??
3065 if (config->cluster_iam_master)
3066 cluster_heartbeat(); // Flush any queued changes..
3067
3068 // Ok. Notify everyone we're shutting down. If we're
3069 // the master, this will force an election.
3070 cluster_send_ping(0);
3071
3072 //
3073 // Important!!! We MUST not process any packets past this point!
3074 }
3075
3076 static void stripdomain(char *host)
3077 {
3078 char *p;
3079
3080 if ((p = strchr(host, '.')))
3081 {
3082 char *domain = 0;
3083 char _domain[1024];
3084
3085 // strip off domain
3086 FILE *resolv = fopen("/etc/resolv.conf", "r");
3087 if (resolv)
3088 {
3089 char buf[1024];
3090 char *b;
3091
3092 while (fgets(buf, sizeof(buf), resolv))
3093 {
3094 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3095 continue;
3096
3097 if (!isspace(buf[6]))
3098 continue;
3099
3100 b = buf + 7;
3101 while (isspace(*b)) b++;
3102
3103 if (*b)
3104 {
3105 char *d = b;
3106 while (*b && !isspace(*b)) b++;
3107 *b = 0;
3108 if (buf[0] == 'd') // domain is canonical
3109 {
3110 domain = d;
3111 break;
3112 }
3113
3114 // first search line
3115 if (!domain)
3116 {
3117 // hold, may be subsequent domain line
3118 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3119 domain = _domain;
3120 }
3121 }
3122 }
3123
3124 fclose(resolv);
3125 }
3126
3127 if (domain)
3128 {
3129 int hl = strlen(host);
3130 int dl = strlen(domain);
3131 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3132 host[hl -dl - 1] = 0;
3133 }
3134 else
3135 {
3136 *p = 0; // everything after first dot
3137 }
3138 }
3139 }
3140
3141 // Init data structures
3142 static void initdata(int optdebug, char *optconfig)
3143 {
3144 int i;
3145
3146 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3147 {
3148 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3149 exit(1);
3150 }
3151 if (!(config = shared_malloc(sizeof(configt))))
3152 {
3153 LOG(0, 0, 0, "Error doing malloc for configuration: %s\n", strerror(errno));
3154 exit(1);
3155 }
3156 memset(config, 0, sizeof(configt));
3157 time(&config->start_time);
3158 strncpy(config->config_file, optconfig, strlen(optconfig));
3159 config->debug = optdebug;
3160 config->num_tbfs = MAXTBFS;
3161 config->rl_rate = 28; // 28kbps
3162 strcpy(config->random_device, RANDOMDEVICE);
3163
3164 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3165 {
3166 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3167 exit(1);
3168 }
3169 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3170 {
3171 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3172 exit(1);
3173 }
3174
3175 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3176 {
3177 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3178 exit(1);
3179 }
3180
3181 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3182 {
3183 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3184 exit(1);
3185 }
3186
3187 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3188 {
3189 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3190 exit(1);
3191 }
3192
3193 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3194 {
3195 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3196 exit(1);
3197 }
3198 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3199
3200 #ifdef RINGBUFFER
3201 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3202 {
3203 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3204 exit(1);
3205 }
3206 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3207 #endif
3208
3209 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3210 {
3211 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3212 exit(1);
3213 }
3214 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3215
3216 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3217 {
3218 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3219 exit(1);
3220 }
3221 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3222
3223 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3224 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3225 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3226 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3227
3228 // Put all the sessions on the free list marked as undefined.
3229 for (i = 1; i < MAXSESSION; i++)
3230 {
3231 session[i].next = i + 1;
3232 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3233 }
3234 session[MAXSESSION - 1].next = 0;
3235 sessionfree = 1;
3236
3237 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3238 for (i = 1; i < MAXTUNNEL; i++)
3239 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3240
3241 if (!*hostname)
3242 {
3243 // Grab my hostname unless it's been specified
3244 gethostname(hostname, sizeof(hostname));
3245 stripdomain(hostname);
3246 }
3247
3248 _statistics->start_time = _statistics->last_reset = time(NULL);
3249
3250 #ifdef BGP
3251 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3252 {
3253 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3254 exit(1);
3255 }
3256 #endif /* BGP */
3257 }
3258
3259 static int assign_ip_address(sessionidt s)
3260 {
3261 uint32_t i;
3262 int best = -1;
3263 time_t best_time = time_now;
3264 char *u = session[s].user;
3265 char reuse = 0;
3266
3267
3268 CSTAT(assign_ip_address);
3269
3270 for (i = 1; i < ip_pool_size; i++)
3271 {
3272 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3273 continue;
3274
3275 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3276 {
3277 best = i;
3278 reuse = 1;
3279 break;
3280 }
3281
3282 if (ip_address_pool[i].last < best_time)
3283 {
3284 best = i;
3285 if (!(best_time = ip_address_pool[i].last))
3286 break; // never used, grab this one
3287 }
3288 }
3289
3290 if (best < 0)
3291 {
3292 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3293 return 0;
3294 }
3295
3296 session[s].ip = ip_address_pool[best].address;
3297 session[s].ip_pool_index = best;
3298 ip_address_pool[best].assigned = 1;
3299 ip_address_pool[best].last = time_now;
3300 ip_address_pool[best].session = s;
3301 if (session[s].walled_garden)
3302 /* Don't track addresses of users in walled garden (note: this
3303 means that their address isn't "sticky" even if they get
3304 un-gardened). */
3305 ip_address_pool[best].user[0] = 0;
3306 else
3307 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3308
3309 STAT(ip_allocated);
3310 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3311 reuse ? "Reusing" : "Allocating", best);
3312
3313 return 1;
3314 }
3315
3316 static void free_ip_address(sessionidt s)
3317 {
3318 int i = session[s].ip_pool_index;
3319
3320
3321 CSTAT(free_ip_address);
3322
3323 if (!session[s].ip)
3324 return; // what the?
3325
3326 if (i < 0) // Is this actually part of the ip pool?
3327 i = 0;
3328
3329 STAT(ip_freed);
3330 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3331 session[s].ip = 0;
3332 ip_address_pool[i].assigned = 0;
3333 ip_address_pool[i].session = 0;
3334 ip_address_pool[i].last = time_now;
3335 }
3336
3337 //
3338 // Fsck the address pool against the session table.
3339 // Normally only called when we become a master.
3340 //
3341 // This isn't perfect: We aren't keep tracking of which
3342 // users used to have an IP address.
3343 //
3344 void rebuild_address_pool(void)
3345 {
3346 int i;
3347
3348 //
3349 // Zero the IP pool allocation, and build
3350 // a map from IP address to pool index.
3351 for (i = 1; i < MAXIPPOOL; ++i)
3352 {
3353 ip_address_pool[i].assigned = 0;
3354 ip_address_pool[i].session = 0;
3355 if (!ip_address_pool[i].address)
3356 continue;
3357
3358 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3359 }
3360
3361 for (i = 0; i < MAXSESSION; ++i)
3362 {
3363 int ipid;
3364 if (!(session[i].opened && session[i].ip))
3365 continue;
3366
3367 ipid = - lookup_ipmap(htonl(session[i].ip));
3368
3369 if (session[i].ip_pool_index < 0)
3370 {
3371 // Not allocated out of the pool.
3372 if (ipid < 1) // Not found in the pool either? good.
3373 continue;
3374
3375 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3376 i, fmtaddr(session[i].ip, 0), ipid);
3377
3378 // Fall through and process it as part of the pool.
3379 }
3380
3381
3382 if (ipid > MAXIPPOOL || ipid < 0)
3383 {
3384 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3385 ipid = -1;
3386 session[i].ip_pool_index = ipid;
3387 continue;
3388 }
3389
3390 ip_address_pool[ipid].assigned = 1;
3391 ip_address_pool[ipid].session = i;
3392 ip_address_pool[ipid].last = time_now;
3393 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3394 session[i].ip_pool_index = ipid;
3395 cache_ipmap(session[i].ip, i); // Fix the ip map.
3396 }
3397 }
3398
3399 //
3400 // Fix the address pool to match a changed session.
3401 // (usually when the master sends us an update).
3402 static void fix_address_pool(int sid)
3403 {
3404 int ipid;
3405
3406 ipid = session[sid].ip_pool_index;
3407
3408 if (ipid > ip_pool_size)
3409 return; // Ignore it. rebuild_address_pool will fix it up.
3410
3411 if (ip_address_pool[ipid].address != session[sid].ip)
3412 return; // Just ignore it. rebuild_address_pool will take care of it.
3413
3414 ip_address_pool[ipid].assigned = 1;
3415 ip_address_pool[ipid].session = sid;
3416 ip_address_pool[ipid].last = time_now;
3417 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3418 }
3419
3420 //
3421 // Add a block of addresses to the IP pool to hand out.
3422 //
3423 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3424 {
3425 int i;
3426 if (mask == 0)
3427 mask = 0xffffffff; // Host route only.
3428
3429 addr &= mask;
3430
3431 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3432 return ;
3433
3434 for (i = addr ;(i & mask) == addr; ++i)
3435 {
3436 if ((i & 0xff) == 0 || (i&0xff) == 255)
3437 continue; // Skip 0 and broadcast addresses.
3438
3439 ip_address_pool[ip_pool_size].address = i;
3440 ip_address_pool[ip_pool_size].assigned = 0;
3441 ++ip_pool_size;
3442 if (ip_pool_size >= MAXIPPOOL)
3443 {
3444 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3445 return;
3446 }
3447 }
3448 }
3449
3450 // Initialize the IP address pool
3451 static void initippool()
3452 {
3453 FILE *f;
3454 char *p;
3455 char buf[4096];
3456 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3457
3458 if (!(f = fopen(IPPOOLFILE, "r")))
3459 {
3460 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3461 exit(1);
3462 }
3463
3464 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3465 {
3466 char *pool = buf;
3467 buf[4095] = 0; // Force it to be zero terminated/
3468
3469 if (*buf == '#' || *buf == '\n')
3470 continue; // Skip comments / blank lines
3471 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3472 if ((p = (char *)strchr(buf, ':')))
3473 {
3474 in_addr_t src;
3475 *p = '\0';
3476 src = inet_addr(buf);
3477 if (src == INADDR_NONE)
3478 {
3479 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3480 exit(1);
3481 }
3482 // This entry is for a specific IP only
3483 if (src != config->bind_address)
3484 continue;
3485 *p = ':';
3486 pool = p+1;
3487 }
3488 if ((p = (char *)strchr(pool, '/')))
3489 {
3490 // It's a range
3491 int numbits = 0;
3492 in_addr_t start = 0, mask = 0;
3493
3494 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3495 *p++ = 0;
3496 if (!*p || !(numbits = atoi(p)))
3497 {
3498 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3499 continue;
3500 }
3501 start = ntohl(inet_addr(pool));
3502 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3503
3504 // Add a static route for this pool
3505 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3506 fmtaddr(htonl(start), 0), 32 + mask);
3507
3508 routeset(0, start, mask, 0, 1);
3509
3510 add_to_ip_pool(start, mask);
3511 }
3512 else
3513 {
3514 // It's a single ip address
3515 add_to_ip_pool(inet_addr(pool), 0);
3516 }
3517 }
3518 fclose(f);
3519 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3520 }
3521
3522 void snoop_send_packet(char *packet, uint16_t size, in_addr_t destination, uint16_t port)
3523 {
3524 struct sockaddr_in snoop_addr = {0};
3525 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3526 return;
3527
3528 snoop_addr.sin_family = AF_INET;
3529 snoop_addr.sin_addr.s_addr = destination;
3530 snoop_addr.sin_port = ntohs(port);
3531
3532 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3533 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3534 htons(snoop_addr.sin_port));
3535
3536 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3537 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
3538
3539 STAT(packets_snooped);
3540 }
3541
3542 static int dump_session(FILE **f, sessiont *s)
3543 {
3544 if (!s->opened || !s->ip || !(s->cin || s->cout) || !*s->user || s->walled_garden)
3545 return 1;
3546
3547 if (!*f)
3548 {
3549 char filename[1024];
3550 char timestr[64];
3551 time_t now = time(NULL);
3552
3553 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
3554 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
3555
3556 if (!(*f = fopen(filename, "w")))
3557 {
3558 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
3559 return 0;
3560 }
3561
3562 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
3563 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
3564 "# host: %s\n"
3565 "# time: %ld\n"
3566 "# uptime: %ld\n"
3567 "# format: username ip qos uptxoctets downrxoctets\n",
3568 hostname,
3569 now,
3570 now - basetime);
3571 }
3572
3573 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
3574 fprintf(*f, "%s %s %d %u %u\n",
3575 s->user, // username
3576 fmtaddr(htonl(s->ip), 0), // ip
3577 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
3578 (uint32_t) s->cin, // uptxoctets
3579 (uint32_t) s->cout); // downrxoctets
3580
3581 s->pin = s->cin = 0;
3582 s->pout = s->cout = 0;
3583
3584 return 1;
3585 }
3586
3587 static void dump_acct_info(int all)
3588 {
3589 int i;
3590 FILE *f = NULL;
3591
3592
3593 CSTAT(dump_acct_info);
3594
3595 if (shut_acct_n)
3596 {
3597 for (i = 0; i < shut_acct_n; i++)
3598 dump_session(&f, &shut_acct[i]);
3599
3600 shut_acct_n = 0;
3601 }
3602
3603 if (all)
3604 for (i = 1; i <= config->cluster_highest_sessionid; i++)
3605 dump_session(&f, &session[i]);
3606
3607 if (f)
3608 fclose(f);
3609 }
3610
3611 // Main program
3612 int main(int argc, char *argv[])
3613 {
3614 int i;
3615 int optdebug = 0;
3616 char *optconfig = CONFIGFILE;
3617
3618 time(&basetime); // start clock
3619
3620 // scan args
3621 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
3622 {
3623 switch (i)
3624 {
3625 case 'd':
3626 if (fork()) exit(0);
3627 setsid();
3628 freopen("/dev/null", "r", stdin);
3629 freopen("/dev/null", "w", stdout);
3630 freopen("/dev/null", "w", stderr);
3631 break;
3632 case 'v':
3633 optdebug++;
3634 break;
3635 case 'c':
3636 optconfig = optarg;
3637 break;
3638 case 'h':
3639 snprintf(hostname, sizeof(hostname), "%s", optarg);
3640 break;
3641 default:
3642 printf("Args are:\n"
3643 "\t-d\t\tDetach from terminal\n"
3644 "\t-c <file>\tConfig file\n"
3645 "\t-h <hostname>\tForce hostname\n"
3646 "\t-v\t\tDebug\n");
3647
3648 return (0);
3649 break;
3650 }
3651 }
3652
3653 // Start the timer routine off
3654 time(&time_now);
3655 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3656 signal(SIGALRM, sigalrm_handler);
3657 siginterrupt(SIGALRM, 0);
3658
3659 initplugins();
3660 initdata(optdebug, optconfig);
3661
3662 init_cli(hostname);
3663 read_config_file();
3664 init_tbf(config->num_tbfs);
3665
3666 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
3667 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
3668 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
3669 {
3670 struct rlimit rlim;
3671 rlim.rlim_cur = RLIM_INFINITY;
3672 rlim.rlim_max = RLIM_INFINITY;
3673 // Remove the maximum core size
3674 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
3675 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
3676
3677 // Make core dumps go to /tmp
3678 chdir("/tmp");
3679 }
3680
3681 if (config->scheduler_fifo)
3682 {
3683 int ret;
3684 struct sched_param params = {0};
3685 params.sched_priority = 1;
3686
3687 if (get_nprocs() < 2)
3688 {
3689 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
3690 config->scheduler_fifo = 0;
3691 }
3692 else
3693 {
3694 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
3695 {
3696 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
3697 }
3698 else
3699 {
3700 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
3701 config->scheduler_fifo = 0;
3702 }
3703 }
3704 }
3705
3706 /* Set up the cluster communications port. */
3707 if (cluster_init() < 0)
3708 exit(1);
3709
3710 #ifdef BGP
3711 signal(SIGPIPE, SIG_IGN);
3712 bgp_setup(config->as_number);
3713 bgp_add_route(config->bind_address, 0xffffffff);
3714 for (i = 0; i < BGP_NUM_PEERS; i++)
3715 {
3716 if (config->neighbour[i].name[0])
3717 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3718 config->neighbour[i].as, config->neighbour[i].keepalive,
3719 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3720 }
3721 #endif /* BGP */
3722
3723 inittun();
3724 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
3725
3726 initudp();
3727 initrad();
3728 initippool();
3729
3730 signal(SIGHUP, sighup_handler);
3731 signal(SIGTERM, sigterm_handler);
3732 signal(SIGINT, sigterm_handler);
3733 signal(SIGQUIT, sigquit_handler);
3734 signal(SIGCHLD, sigchild_handler);
3735
3736 // Prevent us from getting paged out
3737 if (config->lock_pages)
3738 {
3739 if (!mlockall(MCL_CURRENT))
3740 LOG(1, 0, 0, "Locking pages into memory\n");
3741 else
3742 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
3743 }
3744
3745 alarm(1);
3746
3747 // Drop privileges here
3748 if (config->target_uid > 0 && geteuid() == 0)
3749 setuid(config->target_uid);
3750
3751 mainloop();
3752
3753 #ifdef BGP
3754 /* try to shut BGP down cleanly; with luck the sockets will be
3755 writable since we're out of the select */
3756 for (i = 0; i < BGP_NUM_PEERS; i++)
3757 if (bgp_peers[i].state == Established)
3758 bgp_stop(&bgp_peers[i]);
3759 #endif /* BGP */
3760
3761 /* remove plugins (so cleanup code gets run) */
3762 plugins_done();
3763
3764 // Remove the PID file if we wrote it
3765 if (config->wrote_pid && *config->pid_file == '/')
3766 unlink(config->pid_file);
3767
3768 /* kill CLI children */
3769 signal(SIGTERM, SIG_IGN);
3770 kill(0, SIGTERM);
3771 return 0;
3772 }
3773
3774 static void sighup_handler(int sig)
3775 {
3776 if (log_stream && log_stream != stderr)
3777 {
3778 fclose(log_stream);
3779 log_stream = NULL;
3780 }
3781
3782 read_config_file();
3783 }
3784
3785 static void sigalrm_handler(int sig)
3786 {
3787 // Log current traffic stats
3788
3789 snprintf(config->bandwidth, sizeof(config->bandwidth),
3790 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3791 (udp_rx / 1024.0 / 1024.0 * 8),
3792 (eth_tx / 1024.0 / 1024.0 * 8),
3793 (eth_rx / 1024.0 / 1024.0 * 8),
3794 (udp_tx / 1024.0 / 1024.0 * 8),
3795 ((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
3796 udp_rx_pkt, eth_rx_pkt);
3797
3798 udp_tx = udp_rx = 0;
3799 udp_rx_pkt = eth_rx_pkt = 0;
3800 eth_tx = eth_rx = 0;
3801
3802 if (config->dump_speed)
3803 printf("%s\n", config->bandwidth);
3804
3805 // Update the internal time counter
3806 time(&time_now);
3807 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3808 alarm(1);
3809
3810 {
3811 // Run timer hooks
3812 struct param_timer p = { time_now };
3813 run_plugins(PLUGIN_TIMER, &p);
3814 }
3815
3816 }
3817
3818 static void sigterm_handler(int sig)
3819 {
3820 LOG(1, 0, 0, "Shutting down cleanly\n");
3821 main_quit++;
3822 }
3823
3824 static void sigquit_handler(int sig)
3825 {
3826 int i;
3827
3828 LOG(1, 0, 0, "Shutting down without saving sessions\n");
3829
3830 if (config->cluster_iam_master)
3831 {
3832 for (i = 1; i < MAXSESSION; i++)
3833 {
3834 if (session[i].opened)
3835 sessionkill(i, "L2TPNS Closing");
3836 }
3837 for (i = 1; i < MAXTUNNEL; i++)
3838 {
3839 if (tunnel[i].ip || tunnel[i].state)
3840 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3841 }
3842 }
3843
3844 main_quit++;
3845 }
3846
3847 static void sigchild_handler(int sig)
3848 {
3849 while (waitpid(-1, NULL, WNOHANG) > 0)
3850 ;
3851 }
3852
3853 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
3854 {
3855 MD5_CTX ctx;
3856 *challenge_response = NULL;
3857
3858 if (!*config->l2tpsecret)
3859 {
3860 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
3861 return;
3862 }
3863
3864 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
3865
3866 *challenge_response = (char *)calloc(17, 1);
3867
3868 MD5Init(&ctx);
3869 MD5Update(&ctx, &id, 1);
3870 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
3871 MD5Update(&ctx, challenge, challenge_length);
3872 MD5Final(*challenge_response, &ctx);
3873
3874 return;
3875 }
3876
3877 static int facility_value(char *name)
3878 {
3879 int i;
3880 for (i = 0; facilitynames[i].c_name; i++)
3881 {
3882 if (strcmp(facilitynames[i].c_name, name) == 0)
3883 return facilitynames[i].c_val;
3884 }
3885 return 0;
3886 }
3887
3888 static void update_config()
3889 {
3890 int i;
3891 char *p;
3892 static int timeout = 0;
3893 static int interval = 0;
3894
3895 // Update logging
3896 closelog();
3897 syslog_log = 0;
3898 if (log_stream)
3899 {
3900 fclose(log_stream);
3901 log_stream = NULL;
3902 }
3903
3904 if (*config->log_filename)
3905 {
3906 if (strstr(config->log_filename, "syslog:") == config->log_filename)
3907 {
3908 char *p = config->log_filename + 7;
3909 if (*p)
3910 {
3911 openlog("l2tpns", LOG_PID, facility_value(p));
3912 syslog_log = 1;
3913 }
3914 }
3915 else if (strchr(config->log_filename, '/') == config->log_filename)
3916 {
3917 if ((log_stream = fopen((char *)(config->log_filename), "a")))
3918 {
3919 fseek(log_stream, 0, SEEK_END);
3920 setbuf(log_stream, NULL);
3921 }
3922 else
3923 {
3924 log_stream = stderr;
3925 setbuf(log_stream, NULL);
3926 }
3927 }
3928 }
3929 else
3930 {
3931 log_stream = stderr;
3932 setbuf(log_stream, NULL);
3933 }
3934
3935 // Update radius
3936 config->numradiusservers = 0;
3937 for (i = 0; i < MAXRADSERVER; i++)
3938 if (config->radiusserver[i])
3939 {
3940 config->numradiusservers++;
3941 // Set radius port: if not set, take the port from the
3942 // first radius server. For the first radius server,
3943 // take the #defined default value from l2tpns.h
3944
3945 // test twice, In case someone works with
3946 // a secondary radius server without defining
3947 // a primary one, this will work even then.
3948 if (i>0 && !config->radiusport[i])
3949 config->radiusport[i] = config->radiusport[i-1];
3950 if (!config->radiusport[i])
3951 config->radiusport[i] = RADPORT;
3952 }
3953
3954 if (!config->numradiusservers)
3955 LOG(0, 0, 0, "No RADIUS servers defined!\n");
3956
3957 config->num_radfds = 2 << RADIUS_SHIFT;
3958
3959 // parse radius_authtypes_s
3960 config->radius_authtypes = config->radius_authprefer = 0;
3961 p = config->radius_authtypes_s;
3962 while (*p)
3963 {
3964 char *s = strpbrk(p, " \t,");
3965 int type = 0;
3966
3967 if (s)
3968 {
3969 *s++ = 0;
3970 while (*s == ' ' || *s == '\t')
3971 s++;
3972
3973 if (!*s)
3974 s = 0;
3975 }
3976
3977 if (!strncasecmp("chap", p, strlen(p)))
3978 type = AUTHCHAP;
3979 else if (!strncasecmp("pap", p, strlen(p)))
3980 type = AUTHPAP;
3981 else
3982 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"", p);
3983
3984 config->radius_authtypes |= type;
3985 if (!config->radius_authprefer)
3986 config->radius_authprefer = type;
3987 }
3988
3989 if (!config->radius_authtypes)
3990 {
3991 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
3992 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
3993 }
3994
3995 // normalise radius_authtypes_s
3996 if (config->radius_authprefer == AUTHPAP)
3997 {
3998 strcpy(config->radius_authtypes_s, "pap");
3999 if (config->radius_authtypes & AUTHCHAP)
4000 strcat(config->radius_authtypes_s, ", chap");
4001 }
4002 else
4003 {
4004 strcpy(config->radius_authtypes_s, "chap");
4005 if (config->radius_authtypes & AUTHPAP)
4006 strcat(config->radius_authtypes_s, ", pap");
4007 }
4008
4009 // re-initialise the random number source
4010 initrandom(config->random_device);
4011
4012 // Update plugins
4013 for (i = 0; i < MAXPLUGINS; i++)
4014 {
4015 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4016 continue;
4017
4018 if (*config->plugins[i])
4019 {
4020 // Plugin added
4021 add_plugin(config->plugins[i]);
4022 }
4023 else if (*config->old_plugins[i])
4024 {
4025 // Plugin removed
4026 remove_plugin(config->old_plugins[i]);
4027 }
4028 }
4029
4030 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4031 if (!config->cleanup_interval) config->cleanup_interval = 10;
4032 if (!config->multi_read_count) config->multi_read_count = 10;
4033 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4034 if (!*config->cluster_interface)
4035 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4036
4037 if (!config->cluster_hb_interval)
4038 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4039
4040 if (!config->cluster_hb_timeout)
4041 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4042
4043 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4044 {
4045 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4046 // late, ensure we're sufficiently larger than that
4047 int t = 4 * config->cluster_hb_interval + 11;
4048
4049 if (config->cluster_hb_timeout < t)
4050 {
4051 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4052 config->cluster_hb_timeout = t;
4053 }
4054
4055 // Push timing changes to the slaves immediately if we're the master
4056 if (config->cluster_iam_master)
4057 cluster_heartbeat();
4058
4059 interval = config->cluster_hb_interval;
4060 timeout = config->cluster_hb_timeout;
4061 }
4062
4063 // Write PID file
4064 if (*config->pid_file == '/' && !config->wrote_pid)
4065 {
4066 FILE *f;
4067 if ((f = fopen(config->pid_file, "w")))
4068 {
4069 fprintf(f, "%d\n", getpid());
4070 fclose(f);
4071 config->wrote_pid = 1;
4072 }
4073 else
4074 {
4075 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4076 }
4077 }
4078
4079 config->reload_config = 0;
4080 }
4081
4082 static void read_config_file()
4083 {
4084 FILE *f;
4085
4086 if (!config->config_file) return;
4087 if (!(f = fopen(config->config_file, "r")))
4088 {
4089 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4090 return;
4091 }
4092
4093 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4094 cli_do_file(f);
4095 LOG(3, 0, 0, "Done reading config file\n");
4096 fclose(f);
4097 update_config();
4098 }
4099
4100 int sessionsetup(tunnelidt t, sessionidt s)
4101 {
4102 // A session now exists, set it up
4103 in_addr_t ip;
4104 char *user;
4105 sessionidt i;
4106 int r;
4107
4108 CSTAT(sessionsetup);
4109
4110 LOG(3, s, t, "Doing session setup for session\n");
4111
4112 if (!session[s].ip)
4113 {
4114 assign_ip_address(s);
4115 if (!session[s].ip)
4116 {
4117 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4118 sessionshutdown(s, "No IP addresses available", 2, 7);
4119 return 0;
4120 }
4121 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4122 fmtaddr(htonl(session[s].ip), 0));
4123 }
4124
4125
4126 // Make sure this is right
4127 session[s].tunnel = t;
4128
4129 // zap old sessions with same IP and/or username
4130 // Don't kill gardened sessions - doing so leads to a DoS
4131 // from someone who doesn't need to know the password
4132 {
4133 ip = session[s].ip;
4134 user = session[s].user;
4135 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4136 {
4137 if (i == s) continue;
4138 if (ip == session[i].ip) sessionkill(i, "Duplicate IP address");
4139 if (!session[s].walled_garden && !session[i].walled_garden && strcasecmp(user, session[i].user) == 0)
4140 sessionkill(i, "Duplicate session for users");
4141 }
4142 }
4143
4144 {
4145 int routed = 0;
4146
4147 // Add the route for this session.
4148 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4149 {
4150 if ((session[s].ip & session[s].route[r].mask) ==
4151 (session[s].route[r].ip & session[s].route[r].mask))
4152 routed++;
4153
4154 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4155 }
4156
4157 // Static IPs need to be routed if not already
4158 // convered by a Framed-Route. Anything else is part
4159 // of the IP address pool and is already routed, it
4160 // just needs to be added to the IP cache.
4161 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4162 if (session[s].ip_pool_index == -1) // static ip
4163 {
4164 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4165 }
4166 else
4167 cache_ipmap(session[s].ip, s);
4168 }
4169
4170 if (!session[s].unique_id)
4171 {
4172 // did this session just finish radius?
4173 LOG(3, s, t, "Sending initial IPCP to client\n");
4174 sendipcp(t, s);
4175 session[s].unique_id = ++last_id;
4176 }
4177
4178 // Run the plugin's against this new session.
4179 {
4180 struct param_new_session data = { &tunnel[t], &session[s] };
4181 run_plugins(PLUGIN_NEW_SESSION, &data);
4182 }
4183
4184 // Allocate TBFs if throttled
4185 if (session[s].throttle_in || session[s].throttle_out)
4186 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4187
4188 session[s].last_packet = time_now;
4189
4190 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4191 fmtaddr(htonl(session[s].ip), 0),
4192 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4193
4194 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4195
4196 return 1; // RADIUS OK and IP allocated, done...
4197 }
4198
4199 //
4200 // This session just got dropped on us by the master or something.
4201 // Make sure our tables up up to date...
4202 //
4203 int load_session(sessionidt s, sessiont *new)
4204 {
4205 int i;
4206 int newip = 0;
4207
4208 // Sanity checks.
4209 if (new->ip_pool_index >= MAXIPPOOL ||
4210 new->tunnel >= MAXTUNNEL)
4211 {
4212 LOG(0, s, 0, "Strange session update received!\n");
4213 // FIXME! What to do here?
4214 return 0;
4215 }
4216
4217 //
4218 // Ok. All sanity checks passed. Now we're committed to
4219 // loading the new session.
4220 //
4221
4222 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4223
4224 // See if routes/ip cache need updating
4225 if (new->ip != session[s].ip)
4226 newip++;
4227
4228 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4229 if (new->route[i].ip != session[s].route[i].ip ||
4230 new->route[i].mask != session[s].route[i].mask)
4231 newip++;
4232
4233 // needs update
4234 if (newip)
4235 {
4236 int routed = 0;
4237
4238 // remove old routes...
4239 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4240 {
4241 if ((session[s].ip & session[s].route[i].mask) ==
4242 (session[s].route[i].ip & session[s].route[i].mask))
4243 routed++;
4244
4245 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4246 }
4247
4248 // ...ip
4249 if (session[s].ip)
4250 {
4251 if (session[s].ip_pool_index == -1) // static IP
4252 {
4253 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4254 }
4255 else // It's part of the IP pool, remove it manually.
4256 uncache_ipmap(session[s].ip);
4257 }
4258
4259 routed = 0;
4260
4261 // add new routes...
4262 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4263 {
4264 if ((new->ip & new->route[i].mask) ==
4265 (new->route[i].ip & new->route[i].mask))
4266 routed++;
4267
4268 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4269 }
4270
4271 // ...ip
4272 if (new->ip)
4273 {
4274 // If there's a new one, add it.
4275 if (new->ip_pool_index == -1)
4276 {
4277 if (!routed) routeset(s, new->ip, 0, 0, 1);
4278 }
4279 else
4280 cache_ipmap(new->ip, s);
4281 }
4282 }
4283
4284 // check v6 routing
4285 if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED))
4286 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4287
4288 // check filters
4289 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4290 {
4291 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4292 new->filter_in = 0;
4293 }
4294
4295 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4296 {
4297 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4298 new->filter_out = 0;
4299 }
4300
4301 if (new->filter_in != session[s].filter_in)
4302 {
4303 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4304 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4305 }
4306
4307 if (new->filter_out != session[s].filter_out)
4308 {
4309 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4310 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4311 }
4312
4313 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4314 // for walking the sessions to forward byte counts to the master.
4315 config->cluster_highest_sessionid = s;
4316
4317 // TEMP: old session struct used a uint32_t to define the throttle
4318 // speed for both up/down, new uses a uint16_t for each. Deal with
4319 // sessions from an old master for migration.
4320 if (new->throttle_out == 0 && new->tbf_out)
4321 new->throttle_out = new->throttle_in;
4322
4323 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4324
4325 // Do fixups into address pool.
4326 if (new->ip_pool_index != -1)
4327 fix_address_pool(s);
4328
4329 return 1;
4330 }
4331
4332 static void initplugins()
4333 {
4334 int i;
4335
4336 loaded_plugins = ll_init();
4337 // Initialize the plugins to nothing
4338 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4339 plugins[i] = ll_init();
4340 }
4341
4342 static void *open_plugin(char *plugin_name, int load)
4343 {
4344 char path[256] = "";
4345
4346 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4347 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4348 return dlopen(path, RTLD_NOW);
4349 }
4350
4351 // plugin callback to get a config value
4352 static void *getconfig(char *key, enum config_typet type)
4353 {
4354 int i;
4355
4356 for (i = 0; config_values[i].key; i++)
4357 {
4358 if (!strcmp(config_values[i].key, key))
4359 {
4360 if (config_values[i].type == type)
4361 return ((void *) config) + config_values[i].offset;
4362
4363 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4364 key, type, config_values[i].type);
4365
4366 return 0;
4367 }
4368 }
4369
4370 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4371 return 0;
4372 }
4373
4374 static int add_plugin(char *plugin_name)
4375 {
4376 static struct pluginfuncs funcs = {
4377 _log,
4378 _log_hex,
4379 fmtaddr,
4380 sessionbyuser,
4381 sessiontbysessionidt,
4382 sessionidtbysessiont,
4383 radiusnew,
4384 radiussend,
4385 getconfig,
4386 sessionkill,
4387 throttle_session,
4388 cluster_send_session,
4389 };
4390
4391 void *p = open_plugin(plugin_name, 1);
4392 int (*initfunc)(struct pluginfuncs *);
4393 int i;
4394
4395 if (!p)
4396 {
4397 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4398 return -1;
4399 }
4400
4401 if (ll_contains(loaded_plugins, p))
4402 {
4403 dlclose(p);
4404 return 0; // already loaded
4405 }
4406
4407 {
4408 int *v = dlsym(p, "plugin_api_version");
4409 if (!v || *v != PLUGIN_API_VERSION)
4410 {
4411 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4412 dlclose(p);
4413 return -1;
4414 }
4415 }
4416
4417 if ((initfunc = dlsym(p, "plugin_init")))
4418 {
4419 if (!initfunc(&funcs))
4420 {
4421 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4422 dlclose(p);
4423 return -1;
4424 }
4425 }
4426
4427 ll_push(loaded_plugins, p);
4428
4429 for (i = 0; i < max_plugin_functions; i++)
4430 {
4431 void *x;
4432 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4433 {
4434 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4435 ll_push(plugins[i], x);
4436 }
4437 }
4438
4439 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4440 return 1;
4441 }
4442
4443 static void run_plugin_done(void *plugin)
4444 {
4445 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4446
4447 if (donefunc)
4448 donefunc();
4449 }
4450
4451 static int remove_plugin(char *plugin_name)
4452 {
4453 void *p = open_plugin(plugin_name, 0);
4454 int loaded = 0;
4455
4456 if (!p)
4457 return -1;
4458
4459 if (ll_contains(loaded_plugins, p))
4460 {
4461 int i;
4462 for (i = 0; i < max_plugin_functions; i++)
4463 {
4464 void *x;
4465 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4466 ll_delete(plugins[i], x);
4467 }
4468
4469 ll_delete(loaded_plugins, p);
4470 run_plugin_done(p);
4471 loaded = 1;
4472 }
4473
4474 dlclose(p);
4475 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4476 return loaded;
4477 }
4478
4479 int run_plugins(int plugin_type, void *data)
4480 {
4481 int (*func)(void *data);
4482
4483 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4484 return PLUGIN_RET_ERROR;
4485
4486 ll_reset(plugins[plugin_type]);
4487 while ((func = ll_next(plugins[plugin_type])))
4488 {
4489 int r = func(data);
4490
4491 if (r != PLUGIN_RET_OK)
4492 return r; // stop here
4493 }
4494
4495 return PLUGIN_RET_OK;
4496 }
4497
4498 static void plugins_done()
4499 {
4500 void *p;
4501
4502 ll_reset(loaded_plugins);
4503 while ((p = ll_next(loaded_plugins)))
4504 run_plugin_done(p);
4505 }
4506
4507 static void processcontrol(uint8_t * buf, int len, struct sockaddr_in *addr, int alen)
4508 {
4509 struct nsctl request;
4510 struct nsctl response;
4511 int type = unpack_control(&request, buf, len);
4512 int r;
4513 void *p;
4514
4515 if (log_stream && config->debug >= 4)
4516 {
4517 if (type < 0)
4518 {
4519 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4520 fmtaddr(addr->sin_addr.s_addr, 0), type);
4521 }
4522 else
4523 {
4524 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4525 dump_control(&request, log_stream);
4526 }
4527 }
4528
4529 switch (type)
4530 {
4531 case NSCTL_REQ_LOAD:
4532 if (request.argc != 1)
4533 {
4534 response.type = NSCTL_RES_ERR;
4535 response.argc = 1;
4536 response.argv[0] = "name of plugin required";
4537 }
4538 else if ((r = add_plugin(request.argv[0])) < 1)
4539 {
4540 response.type = NSCTL_RES_ERR;
4541 response.argc = 1;
4542 response.argv[0] = !r
4543 ? "plugin already loaded"
4544 : "error loading plugin";
4545 }
4546 else
4547 {
4548 response.type = NSCTL_RES_OK;
4549 response.argc = 0;
4550 }
4551
4552 break;
4553
4554 case NSCTL_REQ_UNLOAD:
4555 if (request.argc != 1)
4556 {
4557 response.type = NSCTL_RES_ERR;
4558 response.argc = 1;
4559 response.argv[0] = "name of plugin required";
4560 }
4561 else if ((r = remove_plugin(request.argv[0])) < 1)
4562 {
4563 response.type = NSCTL_RES_ERR;
4564 response.argc = 1;
4565 response.argv[0] = !r
4566 ? "plugin not loaded"
4567 : "plugin not found";
4568 }
4569 else
4570 {
4571 response.type = NSCTL_RES_OK;
4572 response.argc = 0;
4573 }
4574
4575 break;
4576
4577 case NSCTL_REQ_HELP:
4578 response.type = NSCTL_RES_OK;
4579 response.argc = 0;
4580
4581 ll_reset(loaded_plugins);
4582 while ((p = ll_next(loaded_plugins)))
4583 {
4584 char **help = dlsym(p, "plugin_control_help");
4585 while (response.argc < 0xff && help && *help)
4586 response.argv[response.argc++] = *help++;
4587 }
4588
4589 break;
4590
4591 case NSCTL_REQ_CONTROL:
4592 {
4593 struct param_control param = {
4594 config->cluster_iam_master,
4595 request.argc,
4596 request.argv,
4597 0,
4598 NULL,
4599 };
4600
4601 int r = run_plugins(PLUGIN_CONTROL, &param);
4602
4603 if (r == PLUGIN_RET_ERROR)
4604 {
4605 response.type = NSCTL_RES_ERR;
4606 response.argc = 1;
4607 response.argv[0] = param.additional
4608 ? param.additional
4609 : "error returned by plugin";
4610 }
4611 else if (r == PLUGIN_RET_NOTMASTER)
4612 {
4613 static char msg[] = "must be run on master: 000.000.000.000";
4614
4615 response.type = NSCTL_RES_ERR;
4616 response.argc = 1;
4617 if (config->cluster_master_address)
4618 {
4619 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
4620 response.argv[0] = msg;
4621 }
4622 else
4623 {
4624 response.argv[0] = "must be run on master: none elected";
4625 }
4626 }
4627 else if (!(param.response & NSCTL_RESPONSE))
4628 {
4629 response.type = NSCTL_RES_ERR;
4630 response.argc = 1;
4631 response.argv[0] = param.response
4632 ? "unrecognised response value from plugin"
4633 : "unhandled action";
4634 }
4635 else
4636 {
4637 response.type = param.response;
4638 response.argc = 0;
4639 if (param.additional)
4640 {
4641 response.argc = 1;
4642 response.argv[0] = param.additional;
4643 }
4644 }
4645 }
4646
4647 break;
4648
4649 default:
4650 response.type = NSCTL_RES_ERR;
4651 response.argc = 1;
4652 response.argv[0] = "error unpacking control packet";
4653 }
4654
4655 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
4656 if (!buf)
4657 {
4658 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
4659 return;
4660 }
4661
4662 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
4663 if (r > 0)
4664 {
4665 sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
4666 if (log_stream && config->debug >= 4)
4667 {
4668 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4669 dump_control(&response, log_stream);
4670 }
4671 }
4672 else
4673 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
4674 fmtaddr(addr->sin_addr.s_addr, 0), r);
4675
4676 free(buf);
4677 }
4678
4679 static tunnelidt new_tunnel()
4680 {
4681 tunnelidt i;
4682 for (i = 1; i < MAXTUNNEL; i++)
4683 {
4684 if (tunnel[i].state == TUNNELFREE)
4685 {
4686 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
4687 if (i > config->cluster_highest_tunnelid)
4688 config->cluster_highest_tunnelid = i;
4689 return i;
4690 }
4691 }
4692 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
4693 return 0;
4694 }
4695
4696 //
4697 // We're becoming the master. Do any required setup..
4698 //
4699 // This is principally telling all the plugins that we're
4700 // now a master, and telling them about all the sessions
4701 // that are active too..
4702 //
4703 void become_master(void)
4704 {
4705 int s, i;
4706 run_plugins(PLUGIN_BECOME_MASTER, NULL);
4707
4708 // running a bunch of iptables commands is slow and can cause
4709 // the master to drop tunnels on takeover--kludge around the
4710 // problem by forking for the moment (note: race)
4711 if (!fork_and_close())
4712 {
4713 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4714 {
4715 if (!session[s].opened) // Not an in-use session.
4716 continue;
4717
4718 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
4719 }
4720 exit(0);
4721 }
4722
4723 // add radius fds
4724 for (i = 0; i < config->num_radfds; i++)
4725 {
4726 FD_SET(radfds[i], &readset);
4727 if (radfds[i] > readset_n)
4728 readset_n = radfds[i];
4729 }
4730 }
4731
4732 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
4733 {
4734 int s, i;
4735 int count = 0;
4736 int buckets[64];
4737
4738 if (CLI_HELP_REQUESTED)
4739 return CLI_HELP_NO_ARGS;
4740
4741 time(&time_now);
4742 for (i = 0; i < 64;++i) buckets[i] = 0;
4743
4744 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4745 {
4746 int idle;
4747 if (!session[s].opened)
4748 continue;
4749
4750 idle = time_now - session[s].last_packet;
4751 idle /= 5 ; // In multiples of 5 seconds.
4752 if (idle < 0)
4753 idle = 0;
4754 if (idle > 63)
4755 idle = 63;
4756
4757 ++count;
4758 ++buckets[idle];
4759 }
4760
4761 for (i = 0; i < 63; ++i)
4762 {
4763 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
4764 }
4765 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
4766 cli_print(cli, "%d total sessions open.", count);
4767 return CLI_OK;
4768 }
4769
4770 int cmd_show_hist_open(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 open = 0, d;
4785 if (!session[s].opened)
4786 continue;
4787
4788 d = time_now - session[s].opened;
4789 if (d < 0)
4790 d = 0;
4791 while (d > 1 && open < 32)
4792 {
4793 ++open;
4794 d >>= 1; // half.
4795 }
4796 ++count;
4797 ++buckets[open];
4798 }
4799
4800 s = 1;
4801 for (i = 0; i < 30; ++i)
4802 {
4803 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
4804 s <<= 1;
4805 }
4806 cli_print(cli, "%d total sessions open.", count);
4807 return CLI_OK;
4808 }
4809
4810 /* Unhide an avp.
4811 *
4812 * This unencodes the AVP using the L2TP secret and the previously
4813 * stored random vector. It overwrites the hidden data with the
4814 * unhidden AVP subformat.
4815 */
4816 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
4817 {
4818 MD5_CTX ctx;
4819 uint8_t digest[16];
4820 uint8_t *last;
4821 size_t d = 0;
4822
4823 // Compute initial pad
4824 MD5Init(&ctx);
4825 MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
4826 MD5Update(&ctx, (uint8_t) type & 0xff, 1);
4827 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4828 MD5Update(&ctx, vector, vec_len);
4829 MD5Final(digest, &ctx);
4830
4831 // pointer to last decoded 16 octets
4832 last = value;
4833
4834 while (len > 0)
4835 {
4836 // calculate a new pad based on the last decoded block
4837 if (d >= sizeof(digest))
4838 {
4839 MD5Init(&ctx);
4840 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4841 MD5Update(&ctx, last, sizeof(digest));
4842 MD5Final(digest, &ctx);
4843
4844 d = 0;
4845 last = value;
4846 }
4847
4848 *value++ ^= digest[d++];
4849 len--;
4850 }
4851 }
4852
4853 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
4854 {
4855 switch (p->op)
4856 {
4857 case FILTER_PORT_OP_EQ: return port == p->port;
4858 case FILTER_PORT_OP_NEQ: return port != p->port;
4859 case FILTER_PORT_OP_GT: return port > p->port;
4860 case FILTER_PORT_OP_LT: return port < p->port;
4861 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
4862 }
4863
4864 return 0;
4865 }
4866
4867 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
4868 {
4869 switch (op)
4870 {
4871 case FILTER_FLAG_OP_ANY:
4872 return (flags & sflags) || (~flags & cflags);
4873
4874 case FILTER_FLAG_OP_ALL:
4875 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
4876
4877 case FILTER_FLAG_OP_EST:
4878 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
4879 }
4880
4881 return 0;
4882 }
4883
4884 int ip_filter(uint8_t *buf, int len, uint8_t filter)
4885 {
4886 uint16_t frag_offset;
4887 uint8_t proto;
4888 in_addr_t src_ip;
4889 in_addr_t dst_ip;
4890 uint16_t src_port = 0;
4891 uint16_t dst_port = 0;
4892 uint8_t flags = 0;
4893 ip_filter_rulet *rule;
4894
4895 if (len < 20) // up to end of destination address
4896 return 0;
4897
4898 if ((*buf >> 4) != 4) // IPv4
4899 return 0;
4900
4901 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
4902 proto = buf[9];
4903 src_ip = *(in_addr_t *) (buf + 12);
4904 dst_ip = *(in_addr_t *) (buf + 16);
4905
4906 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
4907 {
4908 int l = (buf[0] & 0xf) * 4; // length of IP header
4909 if (len < l + 4) // ports
4910 return 0;
4911
4912 src_port = ntohs(*(uint16_t *) (buf + l));
4913 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
4914 if (proto == IPPROTO_TCP)
4915 {
4916 if (len < l + 14) // flags
4917 return 0;
4918
4919 flags = buf[l + 13] & 0x3f;
4920 }
4921 }
4922
4923 for (rule = ip_filters[filter].rules; rule->action; rule++)
4924 {
4925 if (rule->proto != IPPROTO_IP && proto != rule->proto)
4926 continue;
4927
4928 if (rule->src_wild != INADDR_BROADCAST &&
4929 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
4930 continue;
4931
4932 if (rule->dst_wild != INADDR_BROADCAST &&
4933 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
4934 continue;
4935
4936 if (frag_offset)
4937 {
4938 if (!rule->frag || rule->action == FILTER_ACTION_DENY)
4939 continue;
4940 }
4941 else
4942 {
4943 if (rule->frag)
4944 continue;
4945
4946 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
4947 {
4948 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
4949 continue;
4950
4951 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
4952 continue;
4953
4954 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
4955 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
4956 continue;
4957 }
4958 }
4959
4960 // matched
4961 rule->counter++;
4962 return rule->action == FILTER_ACTION_PERMIT;
4963 }
4964
4965 // default deny
4966 return 0;
4967 }