b988b788ca7e6d77f212565b0571199eac3d3bc1
[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 1.86 2005-03-10 05:47:24 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)
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 (!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 { // Send CDN
1512 controlt *c = controlnew(14); // sending CDN
1513 control16(c, 1, 3, 1); // result code (admin reasons - TBA make error, general error, add message
1514 control16(c, 14, s, 1); // assigned session (our end)
1515 controladd(c, session[s].tunnel, s); // send the message
1516 }
1517
1518 if (!session[s].die)
1519 session[s].die = TIME + 150; // Clean up in 15 seconds
1520
1521 // update filter refcounts
1522 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
1523 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
1524
1525 cluster_send_session(s);
1526 }
1527
1528 void sendipcp(tunnelidt t, sessionidt s)
1529 {
1530 uint8_t buf[MAXCONTROL];
1531 uint16_t r = session[s].radius;
1532 uint8_t *q;
1533
1534 CSTAT(sendipcp);
1535
1536 if (!r)
1537 r = radiusnew(s);
1538
1539 if (radius[r].state != RADIUSIPCP)
1540 {
1541 radius[r].state = RADIUSIPCP;
1542 radius[r].try = 0;
1543 }
1544
1545 radius[r].retry = backoff(radius[r].try++);
1546 if (radius[r].try > 10)
1547 {
1548 radiusclear(r, s); // Clear radius session.
1549 sessionshutdown(s, "No reply on IPCP");
1550 return;
1551 }
1552
1553 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
1554 if (!q) return;
1555
1556 *q = ConfigReq;
1557 q[1] = r << RADIUS_SHIFT; // ID, dont care, we only send one type of request
1558 *(uint16_t *) (q + 2) = htons(10);
1559 q[4] = 3;
1560 q[5] = 6;
1561 *(in_addr_t *) (q + 6) = config->peer_address ? config->peer_address :
1562 config->bind_address ? config->bind_address :
1563 my_address; // send my IP
1564
1565 tunnelsend(buf, 10 + (q - buf), t); // send it
1566 session[s].flags &= ~SF_IPCP_ACKED; // Clear flag.
1567
1568 // If we have an IPv6 prefix length configured, assume we should
1569 // try to negotiate an IPv6 session as well. Unless we've had a
1570 // (N)ACK for IPV6CP.
1571 if (config->ipv6_prefix.s6_addr[0] > 0 &&
1572 !(session[s].flags & SF_IPV6CP_ACKED) &&
1573 !(session[s].flags & SF_IPV6_NACKED))
1574 {
1575 q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
1576 if (!q) return;
1577
1578 *q = ConfigReq;
1579 q[1] = r << RADIUS_SHIFT; // ID, don't care, we
1580 // only send one type
1581 // of request
1582 *(uint16_t *) (q + 2) = htons(14);
1583 q[4] = 1;
1584 q[5] = 10;
1585 *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
1586 *(uint32_t *) (q + 10) = 0;
1587 q[13] = 1;
1588
1589 tunnelsend(buf, 14 + (q - buf), t); // send it
1590 }
1591 }
1592
1593 // kill a session now
1594 void sessionkill(sessionidt s, char *reason)
1595 {
1596
1597 CSTAT(sessionkill);
1598
1599 if (!session[s].opened) // not alive
1600 return;
1601
1602 if (session[s].next)
1603 {
1604 LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
1605 return;
1606 }
1607
1608 session[s].die = TIME;
1609 sessionshutdown(s, reason); // close radius/routes, etc.
1610 if (session[s].radius)
1611 radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
1612
1613 LOG(2, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
1614
1615 memset(&session[s], 0, sizeof(session[s]));
1616 session[s].tunnel = T_FREE; // Mark it as free.
1617 session[s].next = sessionfree;
1618 sessionfree = s;
1619 cli_session_actions[s].action = 0;
1620 cluster_send_session(s);
1621 }
1622
1623 static void tunnelclear(tunnelidt t)
1624 {
1625 if (!t) return;
1626 memset(&tunnel[t], 0, sizeof(tunnel[t]));
1627 tunnel[t].state = TUNNELFREE;
1628 }
1629
1630 // kill a tunnel now
1631 static void tunnelkill(tunnelidt t, char *reason)
1632 {
1633 sessionidt s;
1634 controlt *c;
1635
1636 CSTAT(tunnelkill);
1637
1638 tunnel[t].state = TUNNELDIE;
1639
1640 // free control messages
1641 while ((c = tunnel[t].controls))
1642 {
1643 controlt * n = c->next;
1644 tunnel[t].controls = n;
1645 tunnel[t].controlc--;
1646 c->next = controlfree;
1647 controlfree = c;
1648 }
1649 // kill sessions
1650 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1651 if (session[s].tunnel == t)
1652 sessionkill(s, reason);
1653
1654 // free tunnel
1655 tunnelclear(t);
1656 LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
1657 cli_tunnel_actions[t].action = 0;
1658 cluster_send_tunnel(t);
1659 }
1660
1661 // shut down a tunnel cleanly
1662 static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
1663 {
1664 sessionidt s;
1665
1666 CSTAT(tunnelshutdown);
1667
1668 if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
1669 {
1670 // never set up, can immediately kill
1671 tunnelkill(t, reason);
1672 return;
1673 }
1674 LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
1675
1676 // close session
1677 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
1678 if (session[s].tunnel == t)
1679 sessionshutdown(s, reason);
1680
1681 tunnel[t].state = TUNNELDIE;
1682 tunnel[t].die = TIME + 700; // Clean up in 70 seconds
1683 cluster_send_tunnel(t);
1684 // TBA - should we wait for sessions to stop?
1685 if (result)
1686 {
1687 controlt *c = controlnew(4); // sending StopCCN
1688 if (error)
1689 {
1690 char buf[64];
1691 int l = 4;
1692 *(uint16_t *) buf = htons(result);
1693 *(uint16_t *) (buf+2) = htons(error);
1694 if (msg)
1695 {
1696 int m = strlen(msg);
1697 if (m + 4 > sizeof(buf))
1698 m = sizeof(buf) - 4;
1699
1700 memcpy(buf+4, msg, m);
1701 l += m;
1702 }
1703
1704 controlb(c, 1, buf, l, 1);
1705 }
1706 else
1707 control16(c, 1, result, 1);
1708
1709 control16(c, 9, t, 1); // assigned tunnel (our end)
1710 controladd(c, t, 0); // send the message
1711 }
1712 }
1713
1714 // read and process packet on tunnel (UDP)
1715 void processudp(uint8_t * buf, int len, struct sockaddr_in *addr)
1716 {
1717 char *chapresponse = NULL;
1718 uint16_t l = len, t = 0, s = 0, ns = 0, nr = 0;
1719 uint8_t *p = buf + 2;
1720
1721
1722 CSTAT(processudp);
1723
1724 udp_rx += len;
1725 udp_rx_pkt++;
1726 LOG_HEX(5, "UDP Data", buf, len);
1727 STAT(tunnel_rx_packets);
1728 INC_STAT(tunnel_rx_bytes, len);
1729 if (len < 6)
1730 {
1731 LOG(1, 0, 0, "Short UDP, %d bytes\n", len);
1732 STAT(tunnel_rx_errors);
1733 return;
1734 }
1735 if ((buf[1] & 0x0F) != 2)
1736 {
1737 LOG(1, 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
1738 STAT(tunnel_rx_errors);
1739 return;
1740 }
1741 if (*buf & 0x40)
1742 { // length
1743 l = ntohs(*(uint16_t *) p);
1744 p += 2;
1745 }
1746 t = ntohs(*(uint16_t *) p);
1747 p += 2;
1748 s = ntohs(*(uint16_t *) p);
1749 p += 2;
1750 if (s >= MAXSESSION)
1751 {
1752 LOG(1, s, t, "Received UDP packet with invalid session ID\n");
1753 STAT(tunnel_rx_errors);
1754 return;
1755 }
1756 if (t >= MAXTUNNEL)
1757 {
1758 LOG(1, s, t, "Received UDP packet with invalid tunnel ID\n");
1759 STAT(tunnel_rx_errors);
1760 return;
1761 }
1762 if (*buf & 0x08)
1763 { // ns/nr
1764 ns = ntohs(*(uint16_t *) p);
1765 p += 2;
1766 nr = ntohs(*(uint16_t *) p);
1767 p += 2;
1768 }
1769 if (*buf & 0x02)
1770 { // offset
1771 uint16_t o = ntohs(*(uint16_t *) p);
1772 p += o + 2;
1773 }
1774 if ((p - buf) > l)
1775 {
1776 LOG(1, s, t, "Bad length %d>%d\n", (int) (p - buf), l);
1777 STAT(tunnel_rx_errors);
1778 return;
1779 }
1780 l -= (p - buf);
1781 if (*buf & 0x80)
1782 { // control
1783 uint16_t message = 0xFFFF; // message type
1784 uint8_t fatal = 0;
1785 uint8_t mandatory = 0;
1786 uint8_t chap = 0; // if CHAP being used
1787 uint16_t asession = 0; // assigned session
1788 uint32_t amagic = 0; // magic number
1789 uint8_t aflags = 0; // flags from last LCF
1790 uint16_t version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
1791 int requestchap = 0; // do we request PAP instead of original CHAP request?
1792 char called[MAXTEL] = ""; // called number
1793 char calling[MAXTEL] = ""; // calling number
1794
1795 if (!config->cluster_iam_master)
1796 {
1797 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
1798 return;
1799 }
1800
1801 // control messages must have bits 0x80|0x40|0x08
1802 // (type, length and sequence) set, and bits 0x02|0x01
1803 // (offset and priority) clear
1804 if ((*buf & 0xCB) != 0xC8)
1805 {
1806 LOG(1, s, t, "Bad control header %02X\n", *buf);
1807 STAT(tunnel_rx_errors);
1808 return;
1809 }
1810
1811 // check for duplicate tunnel open message
1812 if (!t && ns == 0)
1813 {
1814 int i;
1815
1816 //
1817 // Is this a duplicate of the first packet? (SCCRQ)
1818 //
1819 for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
1820 {
1821 if (tunnel[i].state != TUNNELOPENING ||
1822 tunnel[i].ip != ntohl(*(in_addr_t *) & addr->sin_addr) ||
1823 tunnel[i].port != ntohs(addr->sin_port) )
1824 continue;
1825 t = i;
1826 LOG(3, s, t, "Duplicate SCCRQ?\n");
1827 break;
1828 }
1829 }
1830
1831 LOG(3, s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
1832 l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
1833
1834 // if no tunnel specified, assign one
1835 if (!t)
1836 {
1837 if (!(t = new_tunnel()))
1838 {
1839 LOG(1, 0, 0, "No more tunnels\n");
1840 STAT(tunnel_overflow);
1841 return;
1842 }
1843 tunnelclear(t);
1844 tunnel[t].ip = ntohl(*(in_addr_t *) & addr->sin_addr);
1845 tunnel[t].port = ntohs(addr->sin_port);
1846 tunnel[t].window = 4; // default window
1847 STAT(tunnel_created);
1848 LOG(1, 0, t, " New tunnel from %s:%u ID %d\n",
1849 fmtaddr(htonl(tunnel[t].ip), 0), tunnel[t].port, t);
1850 }
1851
1852 // If the 'ns' just received is not the 'nr' we're
1853 // expecting, just send an ack and drop it.
1854 //
1855 // if 'ns' is less, then we got a retransmitted packet.
1856 // if 'ns' is greater than missed a packet. Either way
1857 // we should ignore it.
1858 if (ns != tunnel[t].nr)
1859 {
1860 // is this the sequence we were expecting?
1861 STAT(tunnel_rx_errors);
1862 LOG(1, 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n",
1863 t, ns, tunnel[t].nr);
1864
1865 if (l) // Is this not a ZLB?
1866 controlnull(t);
1867 return;
1868 }
1869
1870 // This is used to time out old tunnels
1871 tunnel[t].lastrec = time_now;
1872
1873 // check sequence of this message
1874 {
1875 int skip = tunnel[t].window; // track how many in-window packets are still in queue
1876 // some to clear maybe?
1877 while (tunnel[t].controlc > 0 && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
1878 {
1879 controlt *c = tunnel[t].controls;
1880 tunnel[t].controls = c->next;
1881 tunnel[t].controlc--;
1882 c->next = controlfree;
1883 controlfree = c;
1884 skip--;
1885 tunnel[t].try = 0; // we have progress
1886 }
1887
1888 // receiver advance (do here so quoted correctly in any sends below)
1889 if (l) tunnel[t].nr = (ns + 1);
1890 if (skip < 0) skip = 0;
1891 if (skip < tunnel[t].controlc)
1892 {
1893 // some control packets can now be sent that were previous stuck out of window
1894 int tosend = tunnel[t].window - skip;
1895 controlt *c = tunnel[t].controls;
1896 while (c && skip)
1897 {
1898 c = c->next;
1899 skip--;
1900 }
1901 while (c && tosend)
1902 {
1903 tunnel[t].try = 0; // first send
1904 tunnelsend(c->buf, c->length, t);
1905 c = c->next;
1906 tosend--;
1907 }
1908 }
1909 if (!tunnel[t].controlc)
1910 tunnel[t].retry = 0; // caught up
1911 }
1912 if (l)
1913 { // if not a null message
1914 int result = 0;
1915 int error = 0;
1916 char *msg = 0;
1917
1918 // process AVPs
1919 while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
1920 {
1921 uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
1922 uint8_t *b = p;
1923 uint8_t flags = *p;
1924 uint16_t mtype;
1925 if (n > l)
1926 {
1927 LOG(1, s, t, "Invalid length in AVP\n");
1928 STAT(tunnel_rx_errors);
1929 return;
1930 }
1931 p += n; // next
1932 l -= n;
1933 if (flags & 0x3C) // reserved bits, should be clear
1934 {
1935 LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
1936 fatal = flags;
1937 result = 2; // general error
1938 error = 3; // reserved field non-zero
1939 msg = 0;
1940 continue; // next
1941 }
1942 b += 2;
1943 if (*(uint16_t *) (b))
1944 {
1945 LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
1946 fatal = flags;
1947 result = 2; // general error
1948 error = 6; // generic vendor-specific error
1949 msg = "unsupported vendor-specific";
1950 continue; // next
1951 }
1952 b += 2;
1953 mtype = ntohs(*(uint16_t *) (b));
1954 b += 2;
1955 n -= 6;
1956
1957 if (flags & 0x40)
1958 {
1959 uint16_t orig_len;
1960
1961 // handle hidden AVPs
1962 if (!*config->l2tpsecret)
1963 {
1964 LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
1965 fatal = flags;
1966 result = 2; // general error
1967 error = 6; // generic vendor-specific error
1968 msg = "secret not specified";
1969 continue;
1970 }
1971 if (!session[s].random_vector_length)
1972 {
1973 LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
1974 fatal = flags;
1975 result = 2; // general error
1976 error = 6; // generic
1977 msg = "no random vector";
1978 continue;
1979 }
1980 if (n < 8)
1981 {
1982 LOG(2, s, t, "Short hidden AVP.\n");
1983 fatal = flags;
1984 result = 2; // general error
1985 error = 2; // length is wrong
1986 msg = 0;
1987 continue;
1988 }
1989
1990 LOG(4, s, t, "Hidden AVP\n");
1991
1992 // Unhide the AVP
1993 unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
1994
1995 orig_len = ntohs(*(uint16_t *) b);
1996 if (orig_len > n + 2)
1997 {
1998 LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
1999 orig_len, n);
2000
2001 fatal = flags;
2002 result = 2; // general error
2003 error = 2; // length is wrong
2004 msg = 0;
2005 continue;
2006 }
2007
2008 b += 2;
2009 n = orig_len;
2010 }
2011
2012 LOG(4, s, t, " AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
2013 switch (mtype)
2014 {
2015 case 0: // message type
2016 message = ntohs(*(uint16_t *) b);
2017 mandatory = flags & 0x80;
2018 LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_message_type(message));
2019 break;
2020 case 1: // result code
2021 {
2022 uint16_t rescode = ntohs(*(uint16_t *) b);
2023 const char* resdesc = "(unknown)";
2024 if (message == 4)
2025 { /* StopCCN */
2026 resdesc = stopccn_result_code(rescode);
2027 }
2028 else if (message == 14)
2029 { /* CDN */
2030 resdesc = cdn_result_code(rescode);
2031 }
2032
2033 LOG(4, s, t, " Result Code %d: %s\n", rescode, resdesc);
2034 if (n >= 4)
2035 {
2036 uint16_t errcode = ntohs(*(uint16_t *)(b + 2));
2037 LOG(4, s, t, " Error Code %d: %s\n", errcode, error_code(errcode));
2038 }
2039 if (n > 4)
2040 LOG(4, s, t, " Error String: %.*s\n", n-4, b+4);
2041
2042 break;
2043 }
2044 break;
2045 case 2: // protocol version
2046 {
2047 version = ntohs(*(uint16_t *) (b));
2048 LOG(4, s, t, " Protocol version = %d\n", version);
2049 if (version && version != 0x0100)
2050 { // allow 0.0 and 1.0
2051 LOG(1, s, t, " Bad protocol version %04X\n", version);
2052 fatal = flags;
2053 result = 5; // unspported protocol version
2054 error = 0x0100; // supported version
2055 msg = 0;
2056 continue; // next
2057 }
2058 }
2059 break;
2060 case 3: // framing capabilities
2061 // LOG(4, s, t, "Framing capabilities\n");
2062 break;
2063 case 4: // bearer capabilities
2064 // LOG(4, s, t, "Bearer capabilities\n");
2065 break;
2066 case 5: // tie breaker
2067 // We never open tunnels, so we don't care about tie breakers
2068 // LOG(4, s, t, "Tie breaker\n");
2069 continue;
2070 case 6: // firmware revision
2071 // LOG(4, s, t, "Firmware revision\n");
2072 break;
2073 case 7: // host name
2074 memset(tunnel[t].hostname, 0, 128);
2075 memcpy(tunnel[t].hostname, b, (n >= 127) ? 127 : n);
2076 LOG(4, s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
2077 // TBA - to send to RADIUS
2078 break;
2079 case 8: // vendor name
2080 memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
2081 memcpy(tunnel[t].vendor, b, (n >= sizeof(tunnel[t].vendor) - 1) ? sizeof(tunnel[t].vendor) - 1 : n);
2082 LOG(4, s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
2083 break;
2084 case 9: // assigned tunnel
2085 tunnel[t].far = ntohs(*(uint16_t *) (b));
2086 LOG(4, s, t, " Remote tunnel id = %d\n", tunnel[t].far);
2087 break;
2088 case 10: // rx window
2089 tunnel[t].window = ntohs(*(uint16_t *) (b));
2090 if (!tunnel[t].window)
2091 tunnel[t].window = 1; // window of 0 is silly
2092 LOG(4, s, t, " rx window = %d\n", tunnel[t].window);
2093 break;
2094 case 11: // Challenge
2095 {
2096 LOG(4, s, t, " LAC requested CHAP authentication for tunnel\n");
2097 build_chap_response(b, 2, n, &chapresponse);
2098 }
2099 break;
2100 case 13: // Response
2101 // Why did they send a response? We never challenge.
2102 LOG(2, s, t, " received unexpected challenge response\n");
2103 break;
2104
2105 case 14: // assigned session
2106 asession = session[s].far = ntohs(*(uint16_t *) (b));
2107 LOG(4, s, t, " assigned session = %d\n", asession);
2108 break;
2109 case 15: // call serial number
2110 LOG(4, s, t, " call serial number = %d\n", ntohl(*(uint32_t *)b));
2111 break;
2112 case 18: // bearer type
2113 LOG(4, s, t, " bearer type = %d\n", ntohl(*(uint32_t *)b));
2114 // TBA - for RADIUS
2115 break;
2116 case 19: // framing type
2117 LOG(4, s, t, " framing type = %d\n", ntohl(*(uint32_t *)b));
2118 // TBA
2119 break;
2120 case 21: // called number
2121 memset(called, 0, MAXTEL);
2122 memcpy(called, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
2123 LOG(4, s, t, " Called <%s>\n", called);
2124 break;
2125 case 22: // calling number
2126 memset(calling, 0, MAXTEL);
2127 memcpy(calling, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
2128 LOG(4, s, t, " Calling <%s>\n", calling);
2129 break;
2130 case 23: // subtype
2131 break;
2132 case 24: // tx connect speed
2133 if (n == 4)
2134 {
2135 session[s].tx_connect_speed = ntohl(*(uint32_t *)b);
2136 }
2137 else
2138 {
2139 // AS5300s send connect speed as a string
2140 char tmp[30] = {0};
2141 memcpy(tmp, b, (n >= 30) ? 30 : n);
2142 session[s].tx_connect_speed = atol(tmp);
2143 }
2144 LOG(4, s, t, " TX connect speed <%u>\n", session[s].tx_connect_speed);
2145 break;
2146 case 38: // rx connect speed
2147 if (n == 4)
2148 {
2149 session[s].rx_connect_speed = ntohl(*(uint32_t *)b);
2150 }
2151 else
2152 {
2153 // AS5300s send connect speed as a string
2154 char tmp[30] = {0};
2155 memcpy(tmp, b, (n >= 30) ? 30 : n);
2156 session[s].rx_connect_speed = atol(tmp);
2157 }
2158 LOG(4, s, t, " RX connect speed <%u>\n", session[s].rx_connect_speed);
2159 break;
2160 case 25: // Physical Channel ID
2161 {
2162 uint32_t tmp = ntohl(*(uint32_t *) b);
2163 LOG(4, s, t, " Physical Channel ID <%X>\n", tmp);
2164 break;
2165 }
2166 case 29: // Proxy Authentication Type
2167 {
2168 uint16_t atype = ntohs(*(uint16_t *)b);
2169 LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, auth_type(atype));
2170 requestchap = (atype == 2);
2171 break;
2172 }
2173 case 30: // Proxy Authentication Name
2174 {
2175 char authname[64] = {0};
2176 memcpy(authname, b, (n > 63) ? 63 : n);
2177 LOG(4, s, t, " Proxy Auth Name (%s)\n",
2178 authname);
2179 break;
2180 }
2181 case 31: // Proxy Authentication Challenge
2182 {
2183 memcpy(radius[session[s].radius].auth, b, 16);
2184 LOG(4, s, t, " Proxy Auth Challenge\n");
2185 break;
2186 }
2187 case 32: // Proxy Authentication ID
2188 {
2189 uint16_t authid = ntohs(*(uint16_t *)(b));
2190 LOG(4, s, t, " Proxy Auth ID (%d)\n", authid);
2191 if (session[s].radius)
2192 radius[session[s].radius].id = authid;
2193 break;
2194 }
2195 case 33: // Proxy Authentication Response
2196 {
2197 char authresp[64] = {0};
2198 memcpy(authresp, b, (n > 63) ? 63 : n);
2199 LOG(4, s, t, " Proxy Auth Response\n");
2200 break;
2201 }
2202 case 27: // last send lcp
2203 { // find magic number
2204 uint8_t *p = b, *e = p + n;
2205 while (p + 1 < e && p[1] && p + p[1] <= e)
2206 {
2207 if (*p == 5 && p[1] == 6) // Magic-Number
2208 amagic = ntohl(*(uint32_t *) (p + 2));
2209 else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol
2210 chap = 1;
2211 else if (*p == 7) // Protocol-Field-Compression
2212 aflags |= SESSIONPFC;
2213 else if (*p == 8) // Address-and-Control-Field-Compression
2214 aflags |= SESSIONACFC;
2215 p += p[1];
2216 }
2217 }
2218 break;
2219 case 28: // last recv lcp confreq
2220 break;
2221 case 26: // Initial Received LCP CONFREQ
2222 break;
2223 case 39: // seq required - we control it as an LNS anyway...
2224 break;
2225 case 36: // Random Vector
2226 LOG(4, s, t, " Random Vector received. Enabled AVP Hiding.\n");
2227 memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
2228 memcpy(session[s].random_vector, b, n);
2229 session[s].random_vector_length = n;
2230 break;
2231 default:
2232 {
2233 static char e[] = "unknown AVP 0xXXXX";
2234 LOG(2, s, t, " Unknown AVP type %d\n", mtype);
2235 fatal = flags;
2236 result = 2; // general error
2237 error = 8; // unknown mandatory AVP
2238 sprintf((msg = e) + 14, "%04x", mtype);
2239 continue; // next
2240 }
2241 }
2242 }
2243 // process message
2244 if (fatal & 0x80)
2245 tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
2246 else
2247 switch (message)
2248 {
2249 case 1: // SCCRQ - Start Control Connection Request
2250 {
2251 controlt *c = controlnew(2); // sending SCCRP
2252 control16(c, 2, version, 1); // protocol version
2253 control32(c, 3, 3, 1); // framing
2254 controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
2255 if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
2256 control16(c, 9, t, 1); // assigned tunnel
2257 controladd(c, t, s); // send the resply
2258 }
2259 tunnel[t].state = TUNNELOPENING;
2260 break;
2261 case 2: // SCCRP
2262 tunnel[t].state = TUNNELOPEN;
2263 break;
2264 case 3: // SCCN
2265 tunnel[t].state = TUNNELOPEN;
2266 controlnull(t); // ack
2267 break;
2268 case 4: // StopCCN
2269 controlnull(t); // ack
2270 tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
2271 break;
2272 case 6: // HELLO
2273 controlnull(t); // simply ACK
2274 break;
2275 case 7: // OCRQ
2276 // TBA
2277 break;
2278 case 8: // OCRO
2279 // TBA
2280 break;
2281 case 9: // OCCN
2282 // TBA
2283 break;
2284 case 10: // ICRQ
2285 if (!sessionfree)
2286 {
2287 STAT(session_overflow);
2288 LOG(1, 0, t, "No free sessions");
2289 return;
2290 }
2291 else
2292 {
2293 uint16_t r;
2294 controlt *c;
2295
2296 s = sessionfree;
2297 sessionfree = session[s].next;
2298 memset(&session[s], 0, sizeof(session[s]));
2299
2300 if (s > config->cluster_highest_sessionid)
2301 config->cluster_highest_sessionid = s;
2302
2303 // make a RADIUS session
2304 if (!(r = radiusnew(s)))
2305 {
2306 LOG(1, s, t, "No free RADIUS sessions for ICRQ\n");
2307 sessionkill(s, "no free RADIUS sesions");
2308 return;
2309 }
2310
2311 c = controlnew(11); // sending ICRP
2312 session[s].id = sessionid++;
2313 session[s].opened = time_now;
2314 session[s].tunnel = t;
2315 session[s].far = asession;
2316 session[s].last_packet = time_now;
2317 LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
2318 control16(c, 14, s, 1); // assigned session
2319 controladd(c, t, s); // send the reply
2320
2321 // Generate a random challenge
2322 random_data(radius[r].auth, sizeof(radius[r].auth));
2323 strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
2324 strncpy(session[s].called, called, sizeof(session[s].called) - 1);
2325 strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
2326 STAT(session_created);
2327 }
2328 break;
2329 case 11: // ICRP
2330 // TBA
2331 break;
2332 case 12: // ICCN
2333 if (amagic == 0) amagic = time_now;
2334 session[s].magic = amagic; // set magic number
2335 session[s].l2tp_flags = aflags; // set flags received
2336 LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
2337 controlnull(t); // ack
2338 // In CHAP state, request PAP instead
2339 if (requestchap)
2340 initlcp(t, s);
2341 break;
2342 case 14: // CDN
2343 controlnull(t); // ack
2344 sessionshutdown(s, "Closed (Received CDN)");
2345 break;
2346 case 0xFFFF:
2347 LOG(1, s, t, "Missing message type\n");
2348 break;
2349 default:
2350 STAT(tunnel_rx_errors);
2351 if (mandatory)
2352 tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
2353 else
2354 LOG(1, s, t, "Unknown message type %d\n", message);
2355 break;
2356 }
2357 if (chapresponse) free(chapresponse);
2358 cluster_send_tunnel(t);
2359 }
2360 else
2361 {
2362 LOG(4, s, t, " Got a ZLB ack\n");
2363 }
2364 }
2365 else
2366 { // data
2367 uint16_t prot;
2368
2369 LOG_HEX(5, "Receive Tunnel Data", p, l);
2370 if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
2371 { // HDLC address header, discard
2372 p += 2;
2373 l -= 2;
2374 }
2375 if (l < 2)
2376 {
2377 LOG(1, s, t, "Short ppp length %d\n", l);
2378 STAT(tunnel_rx_errors);
2379 return;
2380 }
2381 if (*p & 1)
2382 {
2383 prot = *p++;
2384 l--;
2385 }
2386 else
2387 {
2388 prot = ntohs(*(uint16_t *) p);
2389 p += 2;
2390 l -= 2;
2391 }
2392
2393 if (s && !session[s].opened) // Is something wrong??
2394 {
2395 if (!config->cluster_iam_master)
2396 {
2397 // Pass it off to the master to deal with..
2398 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2399 return;
2400 }
2401
2402
2403 LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
2404 STAT(tunnel_rx_errors);
2405 return;
2406 }
2407
2408 if (prot == PPPPAP)
2409 {
2410 session[s].last_packet = time_now;
2411 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2412 processpap(t, s, p, l);
2413 }
2414 else if (prot == PPPCHAP)
2415 {
2416 session[s].last_packet = time_now;
2417 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2418 processchap(t, s, p, l);
2419 }
2420 else if (prot == PPPLCP)
2421 {
2422 session[s].last_packet = time_now;
2423 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2424 processlcp(t, s, p, l);
2425 }
2426 else if (prot == PPPIPCP)
2427 {
2428 session[s].last_packet = time_now;
2429 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2430 processipcp(t, s, p, l);
2431 }
2432 else if (prot == PPPIPV6CP)
2433 {
2434 if (config->ipv6_prefix.s6_addr[0] > 0)
2435 {
2436 session[s].last_packet = time_now;
2437 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2438 processipv6cp(t, s, p, l);
2439 }
2440 else
2441 {
2442 LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n");
2443 }
2444 }
2445 else if (prot == PPPCCP)
2446 {
2447 session[s].last_packet = time_now;
2448 if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
2449 processccp(t, s, p, l);
2450 }
2451 else if (prot == PPPIP)
2452 {
2453 if (session[s].die)
2454 {
2455 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2456 return; // closing session, PPP not processed
2457 }
2458
2459 session[s].last_packet = time_now;
2460 if (session[s].walled_garden && !config->cluster_iam_master)
2461 {
2462 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2463 return;
2464 }
2465
2466 processipin(t, s, p, l);
2467 }
2468 else if (prot == PPPIPV6)
2469 {
2470 if (!config->ipv6_prefix.s6_addr[0] > 0)
2471 {
2472 LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
2473 return;
2474 }
2475 if (session[s].die)
2476 {
2477 LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
2478 return; // closing session, PPP not processed
2479 }
2480
2481 session[s].last_packet = time_now;
2482 if (session[s].walled_garden && !config->cluster_iam_master)
2483 {
2484 master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
2485 return;
2486 }
2487
2488 processipv6in(t, s, p, l);
2489 }
2490 else
2491 {
2492 STAT(tunnel_rx_errors);
2493 LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
2494 }
2495 }
2496 }
2497
2498 // read and process packet on tun
2499 static void processtun(uint8_t * buf, int len)
2500 {
2501 LOG_HEX(5, "Receive TUN Data", buf, len);
2502 STAT(tun_rx_packets);
2503 INC_STAT(tun_rx_bytes, len);
2504
2505 CSTAT(processtun);
2506
2507 eth_rx_pkt++;
2508 eth_rx += len;
2509 if (len < 22)
2510 {
2511 LOG(1, 0, 0, "Short tun packet %d bytes\n", len);
2512 STAT(tun_rx_errors);
2513 return;
2514 }
2515
2516 if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
2517 processipout(buf, len);
2518 else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
2519 && config->ipv6_prefix.s6_addr[0] > 0)
2520 processipv6out(buf, len);
2521
2522 // Else discard.
2523 }
2524
2525 //
2526 // Maximum number of actions to complete.
2527 // This is to avoid sending out too many packets
2528 // at once.
2529 #define MAX_ACTIONS 500
2530
2531 static int regular_cleanups(void)
2532 {
2533 static sessionidt s = 0; // Next session to check for actions on.
2534 tunnelidt t;
2535 int count=0,i;
2536 uint16_t r;
2537 static clockt next_acct = 0;
2538 static clockt next_shut_acct = 0;
2539 int a;
2540
2541 LOG(3, 0, 0, "Begin regular cleanup\n");
2542
2543 for (r = 1; r < MAXRADIUS; r++)
2544 {
2545 if (!radius[r].state)
2546 continue;
2547 if (radius[r].retry)
2548 {
2549 if (radius[r].retry <= TIME)
2550 radiusretry(r);
2551 } else
2552 radius[r].retry = backoff(radius[r].try+1); // Is this really needed? --mo
2553 }
2554 for (t = 1; t <= config->cluster_highest_tunnelid; t++)
2555 {
2556 // check for expired tunnels
2557 if (tunnel[t].die && tunnel[t].die <= TIME)
2558 {
2559 STAT(tunnel_timeout);
2560 tunnelkill(t, "Expired");
2561 continue;
2562 }
2563 // check for message resend
2564 if (tunnel[t].retry && tunnel[t].controlc)
2565 {
2566 // resend pending messages as timeout on reply
2567 if (tunnel[t].retry <= TIME)
2568 {
2569 controlt *c = tunnel[t].controls;
2570 uint8_t w = tunnel[t].window;
2571 tunnel[t].try++; // another try
2572 if (tunnel[t].try > 5)
2573 tunnelkill(t, "Timeout on control message"); // game over
2574 else
2575 while (c && w--)
2576 {
2577 tunnelsend(c->buf, c->length, t);
2578 c = c->next;
2579 }
2580 }
2581 }
2582 // Send hello
2583 if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < TIME + 600)
2584 {
2585 controlt *c = controlnew(6); // sending HELLO
2586 controladd(c, t, 0); // send the message
2587 LOG(3, 0, t, "Sending HELLO message\n");
2588 }
2589
2590 // Check for tunnel changes requested from the CLI
2591 if ((a = cli_tunnel_actions[t].action))
2592 {
2593 cli_tunnel_actions[t].action = 0;
2594 if (a & CLI_TUN_KILL)
2595 {
2596 LOG(2, 0, t, "Dropping tunnel by CLI\n");
2597 tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
2598 }
2599 }
2600
2601 }
2602
2603 count = 0;
2604 for (i = 1; i <= config->cluster_highest_sessionid; i++)
2605 {
2606 s++;
2607 if (s > config->cluster_highest_sessionid)
2608 s = 1;
2609
2610 if (!session[s].opened) // Session isn't in use
2611 continue;
2612
2613 if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
2614 {
2615 // IPCP has not completed yet. Resend
2616 LOG(3, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
2617 sendipcp(session[s].tunnel, s);
2618 }
2619
2620 // check for expired sessions
2621 if (session[s].die && session[s].die <= TIME)
2622 {
2623 sessionkill(s, "Expired");
2624 if (++count >= MAX_ACTIONS) break;
2625 continue;
2626 }
2627
2628 // Drop sessions who have not responded within IDLE_TIMEOUT seconds
2629 if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
2630 {
2631 sessionshutdown(s, "No response to LCP ECHO requests");
2632 STAT(session_timeout);
2633 if (++count >= MAX_ACTIONS) break;
2634 continue;
2635 }
2636
2637 // No data in IDLE_TIMEOUT seconds, send LCP ECHO
2638 if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
2639 {
2640 uint8_t b[MAXCONTROL] = {0};
2641
2642 uint8_t *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
2643 if (!q) continue;
2644
2645 *q = EchoReq;
2646 *(uint8_t *)(q + 1) = (time_now % 255); // ID
2647 *(uint16_t *)(q + 2) = htons(8); // Length
2648 *(uint32_t *)(q + 4) = 0; // Magic Number (not supported)
2649
2650 LOG(4, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
2651 (int)(time_now - session[s].last_packet));
2652 tunnelsend(b, 24, session[s].tunnel); // send it
2653 if (++count >= MAX_ACTIONS) break;
2654 }
2655
2656 // Check for actions requested from the CLI
2657 if ((a = cli_session_actions[s].action))
2658 {
2659 int send = 0;
2660
2661 cli_session_actions[s].action = 0;
2662 if (a & CLI_SESS_KILL)
2663 {
2664 LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
2665 sessionshutdown(s, "Requested by administrator");
2666 a = 0; // dead, no need to check for other actions
2667 }
2668
2669 if (a & CLI_SESS_NOSNOOP)
2670 {
2671 LOG(2, s, session[s].tunnel, "Unsnooping session by CLI\n");
2672 session[s].snoop_ip = 0;
2673 session[s].snoop_port = 0;
2674 send++;
2675 }
2676 else if (a & CLI_SESS_SNOOP)
2677 {
2678 LOG(2, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
2679 fmtaddr(cli_session_actions[s].snoop_ip, 0),
2680 cli_session_actions[s].snoop_port);
2681
2682 session[s].snoop_ip = cli_session_actions[s].snoop_ip;
2683 session[s].snoop_port = cli_session_actions[s].snoop_port;
2684 send++;
2685 }
2686
2687 if (a & CLI_SESS_NOTHROTTLE)
2688 {
2689 LOG(2, s, session[s].tunnel, "Un-throttling session by CLI\n");
2690 throttle_session(s, 0, 0);
2691 send++;
2692 }
2693 else if (a & CLI_SESS_THROTTLE)
2694 {
2695 LOG(2, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
2696 cli_session_actions[s].throttle_in,
2697 cli_session_actions[s].throttle_out);
2698
2699 throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
2700 send++;
2701 }
2702
2703 if (a & CLI_SESS_NOFILTER)
2704 {
2705 LOG(2, s, session[s].tunnel, "Un-filtering session by CLI\n");
2706 filter_session(s, 0, 0);
2707 send++;
2708 }
2709 else if (a & CLI_SESS_FILTER)
2710 {
2711 LOG(2, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
2712 cli_session_actions[s].filter_in,
2713 cli_session_actions[s].filter_out);
2714
2715 filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
2716 send++;
2717 }
2718
2719 if (send)
2720 cluster_send_session(s);
2721
2722 if (++count >= MAX_ACTIONS) break;
2723 }
2724 }
2725
2726 if (*config->accounting_dir)
2727 {
2728 if (next_acct <= TIME)
2729 {
2730 // Dump accounting data
2731 next_acct = TIME + ACCT_TIME;
2732 next_shut_acct = TIME + ACCT_SHUT_TIME;
2733 dump_acct_info(1);
2734 }
2735 else if (next_shut_acct <= TIME)
2736 {
2737 // Dump accounting data for shutdown sessions
2738 next_shut_acct = TIME + ACCT_SHUT_TIME;
2739 if (shut_acct_n)
2740 dump_acct_info(0);
2741 }
2742 }
2743
2744 if (count >= MAX_ACTIONS)
2745 return 1; // Didn't finish!
2746
2747 LOG(3, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
2748 return 0;
2749 }
2750
2751
2752 //
2753 // Are we in the middle of a tunnel update, or radius
2754 // requests??
2755 //
2756 static int still_busy(void)
2757 {
2758 int i;
2759 static clockt last_talked = 0;
2760 static clockt start_busy_wait = 0;
2761 if (start_busy_wait == 0)
2762 start_busy_wait = TIME;
2763
2764 for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
2765 {
2766 if (!tunnel[i].controlc)
2767 continue;
2768
2769 if (last_talked != TIME)
2770 {
2771 LOG(2, 0, 0, "Tunnel %d still has un-acked control messages.\n", i);
2772 last_talked = TIME;
2773 }
2774 return 1;
2775 }
2776
2777 // We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
2778 if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
2779 {
2780 LOG(1, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
2781 return 0;
2782 }
2783
2784 for (i = 1; i < MAXRADIUS; i++)
2785 {
2786 if (radius[i].state == RADIUSNULL)
2787 continue;
2788 if (radius[i].state == RADIUSWAIT)
2789 continue;
2790
2791 if (last_talked != TIME)
2792 {
2793 LOG(2, 0, 0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
2794 last_talked = TIME;
2795 }
2796 return 1;
2797 }
2798
2799 return 0;
2800 }
2801
2802 static fd_set readset;
2803 static int readset_n = 0;
2804
2805 // main loop - gets packets on tun or udp and processes them
2806 static void mainloop(void)
2807 {
2808 int i;
2809 uint8_t buf[65536];
2810 struct timeval to;
2811 clockt next_cluster_ping = 0; // send initial ping immediately
2812 time_t next_clean = time_now + config->cleanup_interval;
2813
2814 LOG(4, 0, 0, "Beginning of main loop. udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
2815 udpfd, tunfd, cluster_sockfd, controlfd);
2816
2817 FD_ZERO(&readset);
2818 FD_SET(udpfd, &readset);
2819 FD_SET(tunfd, &readset);
2820 FD_SET(controlfd, &readset);
2821 FD_SET(clifd, &readset);
2822 if (cluster_sockfd) FD_SET(cluster_sockfd, &readset);
2823 readset_n = udpfd;
2824 if (tunfd > readset_n) readset_n = tunfd;
2825 if (controlfd > readset_n) readset_n = controlfd;
2826 if (clifd > readset_n) readset_n = clifd;
2827 if (cluster_sockfd > readset_n) readset_n = cluster_sockfd;
2828
2829 while (!main_quit || still_busy())
2830 {
2831 fd_set r;
2832 int n = readset_n;
2833 #ifdef BGP
2834 fd_set w;
2835 int bgp_set[BGP_NUM_PEERS];
2836 #endif /* BGP */
2837
2838 if (config->reload_config)
2839 {
2840 // Update the config state based on config settings
2841 update_config();
2842 }
2843
2844 memcpy(&r, &readset, sizeof(fd_set));
2845 to.tv_sec = 0;
2846 to.tv_usec = 100000; // 1/10th of a second.
2847
2848 #ifdef BGP
2849 FD_ZERO(&w);
2850 for (i = 0; i < BGP_NUM_PEERS; i++)
2851 {
2852 bgp_set[i] = bgp_select_state(&bgp_peers[i]);
2853 if (bgp_set[i] & 1)
2854 {
2855 FD_SET(bgp_peers[i].sock, &r);
2856 if (bgp_peers[i].sock > n)
2857 n = bgp_peers[i].sock;
2858 }
2859
2860 if (bgp_set[i] & 2)
2861 {
2862 FD_SET(bgp_peers[i].sock, &w);
2863 if (bgp_peers[i].sock > n)
2864 n = bgp_peers[i].sock;
2865 }
2866 }
2867
2868 n = select(n + 1, &r, &w, 0, &to);
2869 #else /* BGP */
2870 n = select(n + 1, &r, 0, 0, &to);
2871 #endif /* BGP */
2872
2873 STAT(select_called);
2874
2875 TIME = now();
2876 if (n < 0)
2877 {
2878 if (errno == EINTR ||
2879 errno == ECHILD) // EINTR was clobbered by sigchild_handler()
2880 continue;
2881
2882 LOG(0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
2883 main_quit++;
2884 break;
2885 }
2886 else if (n)
2887 {
2888 struct sockaddr_in addr;
2889 int alen, c, s;
2890 int udp_pkts = 0;
2891 int tun_pkts = 0;
2892 int cluster_pkts = 0;
2893
2894 // nsctl commands
2895 if (FD_ISSET(controlfd, &r))
2896 {
2897 alen = sizeof(addr);
2898 processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr, alen);
2899 n--;
2900 }
2901
2902 // RADIUS responses
2903 if (config->cluster_iam_master)
2904 {
2905 for (i = 0; i < config->num_radfds; i++)
2906 {
2907 if (FD_ISSET(radfds[i], &r))
2908 {
2909 processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
2910 n--;
2911 }
2912 }
2913 }
2914
2915 // CLI connections
2916 if (FD_ISSET(clifd, &r))
2917 {
2918 int cli;
2919
2920 alen = sizeof(addr);
2921 if ((cli = accept(clifd, (struct sockaddr *)&addr, &alen)) >= 0)
2922 {
2923 cli_do(cli);
2924 close(cli);
2925 }
2926 else
2927 LOG(0, 0, 0, "accept error: %s\n", strerror(errno));
2928
2929 n--;
2930 }
2931
2932 #ifdef BGP
2933 for (i = 0; i < BGP_NUM_PEERS; i++)
2934 {
2935 int isr = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0;
2936 int isw = bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0;
2937 bgp_process(&bgp_peers[i], isr, isw);
2938 if (isr) n--;
2939 if (isw) n--;
2940 }
2941 #endif /* BGP */
2942
2943 for (c = 0; n && c < config->multi_read_count; c++)
2944 {
2945 // L2TP
2946 if (FD_ISSET(udpfd, &r))
2947 {
2948 alen = sizeof(addr);
2949 if ((s = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
2950 {
2951 processudp(buf, s, &addr);
2952 udp_pkts++;
2953 }
2954 else
2955 {
2956 FD_CLR(udpfd, &r);
2957 n--;
2958 }
2959 }
2960
2961 // incoming IP
2962 if (FD_ISSET(tunfd, &r))
2963 {
2964 if ((s = read(tunfd, buf, sizeof(buf))) > 0)
2965 {
2966 processtun(buf, s);
2967 tun_pkts++;
2968 }
2969 else
2970 {
2971 FD_CLR(tunfd, &r);
2972 n--;
2973 }
2974 }
2975
2976 // cluster
2977 if (FD_ISSET(cluster_sockfd, &r))
2978 {
2979 alen = sizeof(addr);
2980 if ((s = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen)) > 0)
2981 {
2982 processcluster(buf, s, addr.sin_addr.s_addr);
2983 cluster_pkts++;
2984 }
2985 else
2986 {
2987 FD_CLR(cluster_sockfd, &r);
2988 n--;
2989 }
2990 }
2991 }
2992
2993 if (udp_pkts > 1 || tun_pkts > 1 || cluster_pkts > 1)
2994 STAT(multi_read_used);
2995
2996 if (c >= config->multi_read_count)
2997 {
2998 LOG(3, 0, 0, "Reached multi_read_count (%d); processed %d udp, %d tun and %d cluster packets\n",
2999 config->multi_read_count, udp_pkts, tun_pkts, cluster_pkts);
3000
3001 STAT(multi_read_exceeded);
3002 }
3003 }
3004
3005 // Runs on every machine (master and slaves).
3006 if (cluster_sockfd && next_cluster_ping <= TIME)
3007 {
3008 // Check to see which of the cluster is still alive..
3009
3010 cluster_send_ping(basetime); // Only does anything if we're a slave
3011 cluster_check_master(); // ditto.
3012
3013 cluster_heartbeat(); // Only does anything if we're a master.
3014 cluster_check_slaves(); // ditto.
3015
3016 master_update_counts(); // If we're a slave, send our byte counters to our master.
3017
3018 if (config->cluster_iam_master && !config->cluster_iam_uptodate)
3019 next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
3020 else
3021 next_cluster_ping = TIME + config->cluster_hb_interval;
3022 }
3023
3024 // Run token bucket filtering queue..
3025 // Only run it every 1/10th of a second.
3026 // Runs on all machines both master and slave.
3027 {
3028 static clockt last_run = 0;
3029 if (last_run != TIME)
3030 {
3031 last_run = TIME;
3032 tbf_run_timer();
3033 }
3034 }
3035
3036 /* Handle timeouts. Make sure that this gets run anyway, even if there was
3037 * something to read, else under load this will never actually run....
3038 *
3039 */
3040 if (config->cluster_iam_master && next_clean <= time_now)
3041 {
3042 if (regular_cleanups())
3043 {
3044 // Did it finish?
3045 next_clean = time_now + 1 ; // Didn't finish. Check quickly.
3046 }
3047 else
3048 {
3049 next_clean = time_now + config->cleanup_interval; // Did. Move to next interval.
3050 }
3051 }
3052 }
3053
3054 // Are we the master and shutting down??
3055 if (config->cluster_iam_master)
3056 cluster_heartbeat(); // Flush any queued changes..
3057
3058 // Ok. Notify everyone we're shutting down. If we're
3059 // the master, this will force an election.
3060 cluster_send_ping(0);
3061
3062 //
3063 // Important!!! We MUST not process any packets past this point!
3064 }
3065
3066 static void stripdomain(char *host)
3067 {
3068 char *p;
3069
3070 if ((p = strchr(host, '.')))
3071 {
3072 char *domain = 0;
3073 char _domain[1024];
3074
3075 // strip off domain
3076 FILE *resolv = fopen("/etc/resolv.conf", "r");
3077 if (resolv)
3078 {
3079 char buf[1024];
3080 char *b;
3081
3082 while (fgets(buf, sizeof(buf), resolv))
3083 {
3084 if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
3085 continue;
3086
3087 if (!isspace(buf[6]))
3088 continue;
3089
3090 b = buf + 7;
3091 while (isspace(*b)) b++;
3092
3093 if (*b)
3094 {
3095 char *d = b;
3096 while (*b && !isspace(*b)) b++;
3097 *b = 0;
3098 if (buf[0] == 'd') // domain is canonical
3099 {
3100 domain = d;
3101 break;
3102 }
3103
3104 // first search line
3105 if (!domain)
3106 {
3107 // hold, may be subsequent domain line
3108 strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
3109 domain = _domain;
3110 }
3111 }
3112 }
3113
3114 fclose(resolv);
3115 }
3116
3117 if (domain)
3118 {
3119 int hl = strlen(host);
3120 int dl = strlen(domain);
3121 if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
3122 host[hl -dl - 1] = 0;
3123 }
3124 else
3125 {
3126 *p = 0; // everything after first dot
3127 }
3128 }
3129 }
3130
3131 // Init data structures
3132 static void initdata(int optdebug, char *optconfig)
3133 {
3134 int i;
3135
3136 if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
3137 {
3138 LOG(0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
3139 exit(1);
3140 }
3141 if (!(config = shared_malloc(sizeof(configt))))
3142 {
3143 LOG(0, 0, 0, "Error doing malloc for configuration: %s\n", strerror(errno));
3144 exit(1);
3145 }
3146 memset(config, 0, sizeof(configt));
3147 time(&config->start_time);
3148 strncpy(config->config_file, optconfig, strlen(optconfig));
3149 config->debug = optdebug;
3150 config->num_tbfs = MAXTBFS;
3151 config->rl_rate = 28; // 28kbps
3152 strcpy(config->random_device, RANDOMDEVICE);
3153
3154 if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
3155 {
3156 LOG(0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
3157 exit(1);
3158 }
3159 if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
3160 {
3161 LOG(0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
3162 exit(1);
3163 }
3164
3165 if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
3166 {
3167 LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
3168 exit(1);
3169 }
3170
3171 if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
3172 {
3173 LOG(0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
3174 exit(1);
3175 }
3176
3177 if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
3178 {
3179 LOG(0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
3180 exit(1);
3181 }
3182
3183 if (!(ip_filters = shared_malloc(sizeof(ip_filtert) * MAXFILTER)))
3184 {
3185 LOG(0, 0, 0, "Error doing malloc for ip_filters: %s\n", strerror(errno));
3186 exit(1);
3187 }
3188 memset(ip_filters, 0, sizeof(ip_filtert) * MAXFILTER);
3189
3190 #ifdef RINGBUFFER
3191 if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
3192 {
3193 LOG(0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
3194 exit(1);
3195 }
3196 memset(ringbuffer, 0, sizeof(struct Tringbuffer));
3197 #endif
3198
3199 if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
3200 {
3201 LOG(0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
3202 exit(1);
3203 }
3204 memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
3205
3206 if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
3207 {
3208 LOG(0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
3209 exit(1);
3210 }
3211 memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
3212
3213 memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
3214 memset(session, 0, sizeof(sessiont) * MAXSESSION);
3215 memset(radius, 0, sizeof(radiust) * MAXRADIUS);
3216 memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
3217
3218 // Put all the sessions on the free list marked as undefined.
3219 for (i = 1; i < MAXSESSION; i++)
3220 {
3221 session[i].next = i + 1;
3222 session[i].tunnel = T_UNDEF; // mark it as not filled in.
3223 }
3224 session[MAXSESSION - 1].next = 0;
3225 sessionfree = 1;
3226
3227 // Mark all the tunnels as undefined (waiting to be filled in by a download).
3228 for (i = 1; i < MAXTUNNEL; i++)
3229 tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
3230
3231 if (!*hostname)
3232 {
3233 // Grab my hostname unless it's been specified
3234 gethostname(hostname, sizeof(hostname));
3235 stripdomain(hostname);
3236 }
3237
3238 _statistics->start_time = _statistics->last_reset = time(NULL);
3239
3240 #ifdef BGP
3241 if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
3242 {
3243 LOG(0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
3244 exit(1);
3245 }
3246 #endif /* BGP */
3247 }
3248
3249 static int assign_ip_address(sessionidt s)
3250 {
3251 uint32_t i;
3252 int best = -1;
3253 time_t best_time = time_now;
3254 char *u = session[s].user;
3255 char reuse = 0;
3256
3257
3258 CSTAT(assign_ip_address);
3259
3260 for (i = 1; i < ip_pool_size; i++)
3261 {
3262 if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
3263 continue;
3264
3265 if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
3266 {
3267 best = i;
3268 reuse = 1;
3269 break;
3270 }
3271
3272 if (ip_address_pool[i].last < best_time)
3273 {
3274 best = i;
3275 if (!(best_time = ip_address_pool[i].last))
3276 break; // never used, grab this one
3277 }
3278 }
3279
3280 if (best < 0)
3281 {
3282 LOG(0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
3283 return 0;
3284 }
3285
3286 session[s].ip = ip_address_pool[best].address;
3287 session[s].ip_pool_index = best;
3288 ip_address_pool[best].assigned = 1;
3289 ip_address_pool[best].last = time_now;
3290 ip_address_pool[best].session = s;
3291 if (session[s].walled_garden)
3292 /* Don't track addresses of users in walled garden (note: this
3293 means that their address isn't "sticky" even if they get
3294 un-gardened). */
3295 ip_address_pool[best].user[0] = 0;
3296 else
3297 strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
3298
3299 STAT(ip_allocated);
3300 LOG(4, s, session[s].tunnel, "assign_ip_address(): %s ip address %d from pool\n",
3301 reuse ? "Reusing" : "Allocating", best);
3302
3303 return 1;
3304 }
3305
3306 static void free_ip_address(sessionidt s)
3307 {
3308 int i = session[s].ip_pool_index;
3309
3310
3311 CSTAT(free_ip_address);
3312
3313 if (!session[s].ip)
3314 return; // what the?
3315
3316 if (i < 0) // Is this actually part of the ip pool?
3317 i = 0;
3318
3319 STAT(ip_freed);
3320 cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
3321 session[s].ip = 0;
3322 ip_address_pool[i].assigned = 0;
3323 ip_address_pool[i].session = 0;
3324 ip_address_pool[i].last = time_now;
3325 }
3326
3327 //
3328 // Fsck the address pool against the session table.
3329 // Normally only called when we become a master.
3330 //
3331 // This isn't perfect: We aren't keep tracking of which
3332 // users used to have an IP address.
3333 //
3334 void rebuild_address_pool(void)
3335 {
3336 int i;
3337
3338 //
3339 // Zero the IP pool allocation, and build
3340 // a map from IP address to pool index.
3341 for (i = 1; i < MAXIPPOOL; ++i)
3342 {
3343 ip_address_pool[i].assigned = 0;
3344 ip_address_pool[i].session = 0;
3345 if (!ip_address_pool[i].address)
3346 continue;
3347
3348 cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
3349 }
3350
3351 for (i = 0; i < MAXSESSION; ++i)
3352 {
3353 int ipid;
3354 if (!(session[i].opened && session[i].ip))
3355 continue;
3356
3357 ipid = - lookup_ipmap(htonl(session[i].ip));
3358
3359 if (session[i].ip_pool_index < 0)
3360 {
3361 // Not allocated out of the pool.
3362 if (ipid < 1) // Not found in the pool either? good.
3363 continue;
3364
3365 LOG(0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
3366 i, fmtaddr(session[i].ip, 0), ipid);
3367
3368 // Fall through and process it as part of the pool.
3369 }
3370
3371
3372 if (ipid > MAXIPPOOL || ipid < 0)
3373 {
3374 LOG(0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
3375 ipid = -1;
3376 session[i].ip_pool_index = ipid;
3377 continue;
3378 }
3379
3380 ip_address_pool[ipid].assigned = 1;
3381 ip_address_pool[ipid].session = i;
3382 ip_address_pool[ipid].last = time_now;
3383 strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
3384 session[i].ip_pool_index = ipid;
3385 cache_ipmap(session[i].ip, i); // Fix the ip map.
3386 }
3387 }
3388
3389 //
3390 // Fix the address pool to match a changed session.
3391 // (usually when the master sends us an update).
3392 static void fix_address_pool(int sid)
3393 {
3394 int ipid;
3395
3396 ipid = session[sid].ip_pool_index;
3397
3398 if (ipid > ip_pool_size)
3399 return; // Ignore it. rebuild_address_pool will fix it up.
3400
3401 if (ip_address_pool[ipid].address != session[sid].ip)
3402 return; // Just ignore it. rebuild_address_pool will take care of it.
3403
3404 ip_address_pool[ipid].assigned = 1;
3405 ip_address_pool[ipid].session = sid;
3406 ip_address_pool[ipid].last = time_now;
3407 strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
3408 }
3409
3410 //
3411 // Add a block of addresses to the IP pool to hand out.
3412 //
3413 static void add_to_ip_pool(in_addr_t addr, in_addr_t mask)
3414 {
3415 int i;
3416 if (mask == 0)
3417 mask = 0xffffffff; // Host route only.
3418
3419 addr &= mask;
3420
3421 if (ip_pool_size >= MAXIPPOOL) // Pool is full!
3422 return ;
3423
3424 for (i = addr ;(i & mask) == addr; ++i)
3425 {
3426 if ((i & 0xff) == 0 || (i&0xff) == 255)
3427 continue; // Skip 0 and broadcast addresses.
3428
3429 ip_address_pool[ip_pool_size].address = i;
3430 ip_address_pool[ip_pool_size].assigned = 0;
3431 ++ip_pool_size;
3432 if (ip_pool_size >= MAXIPPOOL)
3433 {
3434 LOG(0, 0, 0, "Overflowed IP pool adding %s\n", fmtaddr(htonl(addr), 0));
3435 return;
3436 }
3437 }
3438 }
3439
3440 // Initialize the IP address pool
3441 static void initippool()
3442 {
3443 FILE *f;
3444 char *p;
3445 char buf[4096];
3446 memset(ip_address_pool, 0, sizeof(ip_address_pool));
3447
3448 if (!(f = fopen(IPPOOLFILE, "r")))
3449 {
3450 LOG(0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
3451 exit(1);
3452 }
3453
3454 while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
3455 {
3456 char *pool = buf;
3457 buf[4095] = 0; // Force it to be zero terminated/
3458
3459 if (*buf == '#' || *buf == '\n')
3460 continue; // Skip comments / blank lines
3461 if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
3462 if ((p = (char *)strchr(buf, ':')))
3463 {
3464 in_addr_t src;
3465 *p = '\0';
3466 src = inet_addr(buf);
3467 if (src == INADDR_NONE)
3468 {
3469 LOG(0, 0, 0, "Invalid address pool IP %s\n", buf);
3470 exit(1);
3471 }
3472 // This entry is for a specific IP only
3473 if (src != config->bind_address)
3474 continue;
3475 *p = ':';
3476 pool = p+1;
3477 }
3478 if ((p = (char *)strchr(pool, '/')))
3479 {
3480 // It's a range
3481 int numbits = 0;
3482 in_addr_t start = 0, mask = 0;
3483
3484 LOG(2, 0, 0, "Adding IP address range %s\n", buf);
3485 *p++ = 0;
3486 if (!*p || !(numbits = atoi(p)))
3487 {
3488 LOG(0, 0, 0, "Invalid pool range %s\n", buf);
3489 continue;
3490 }
3491 start = ntohl(inet_addr(pool));
3492 mask = (in_addr_t) (pow(2, numbits) - 1) << (32 - numbits);
3493
3494 // Add a static route for this pool
3495 LOG(5, 0, 0, "Adding route for address pool %s/%u\n",
3496 fmtaddr(htonl(start), 0), 32 + mask);
3497
3498 routeset(0, start, mask, 0, 1);
3499
3500 add_to_ip_pool(start, mask);
3501 }
3502 else
3503 {
3504 // It's a single ip address
3505 add_to_ip_pool(inet_addr(pool), 0);
3506 }
3507 }
3508 fclose(f);
3509 LOG(1, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
3510 }
3511
3512 void snoop_send_packet(char *packet, uint16_t size, in_addr_t destination, uint16_t port)
3513 {
3514 struct sockaddr_in snoop_addr = {0};
3515 if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
3516 return;
3517
3518 snoop_addr.sin_family = AF_INET;
3519 snoop_addr.sin_addr.s_addr = destination;
3520 snoop_addr.sin_port = ntohs(port);
3521
3522 LOG(5, 0, 0, "Snooping %d byte packet to %s:%d\n", size,
3523 fmtaddr(snoop_addr.sin_addr.s_addr, 0),
3524 htons(snoop_addr.sin_port));
3525
3526 if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
3527 LOG(0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
3528
3529 STAT(packets_snooped);
3530 }
3531
3532 static int dump_session(FILE **f, sessiont *s)
3533 {
3534 if (!s->opened || !s->ip || !(s->cin || s->cout) || !*s->user || s->walled_garden)
3535 return 1;
3536
3537 if (!*f)
3538 {
3539 char filename[1024];
3540 char timestr[64];
3541 time_t now = time(NULL);
3542
3543 strftime(timestr, sizeof(timestr), "%Y%m%d%H%M%S", localtime(&now));
3544 snprintf(filename, sizeof(filename), "%s/%s", config->accounting_dir, timestr);
3545
3546 if (!(*f = fopen(filename, "w")))
3547 {
3548 LOG(0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
3549 return 0;
3550 }
3551
3552 LOG(3, 0, 0, "Dumping accounting information to %s\n", filename);
3553 fprintf(*f, "# dslwatch.pl dump file V1.01\n"
3554 "# host: %s\n"
3555 "# time: %ld\n"
3556 "# uptime: %ld\n"
3557 "# format: username ip qos uptxoctets downrxoctets\n",
3558 hostname,
3559 now,
3560 now - basetime);
3561 }
3562
3563 LOG(4, 0, 0, "Dumping accounting information for %s\n", s->user);
3564 fprintf(*f, "%s %s %d %u %u\n",
3565 s->user, // username
3566 fmtaddr(htonl(s->ip), 0), // ip
3567 (s->throttle_in || s->throttle_out) ? 2 : 1, // qos
3568 (uint32_t) s->cin, // uptxoctets
3569 (uint32_t) s->cout); // downrxoctets
3570
3571 s->pin = s->cin = 0;
3572 s->pout = s->cout = 0;
3573
3574 return 1;
3575 }
3576
3577 static void dump_acct_info(int all)
3578 {
3579 int i;
3580 FILE *f = NULL;
3581
3582
3583 CSTAT(dump_acct_info);
3584
3585 if (shut_acct_n)
3586 {
3587 for (i = 0; i < shut_acct_n; i++)
3588 dump_session(&f, &shut_acct[i]);
3589
3590 shut_acct_n = 0;
3591 }
3592
3593 if (all)
3594 for (i = 1; i <= config->cluster_highest_sessionid; i++)
3595 dump_session(&f, &session[i]);
3596
3597 if (f)
3598 fclose(f);
3599 }
3600
3601 // Main program
3602 int main(int argc, char *argv[])
3603 {
3604 int i;
3605 int optdebug = 0;
3606 char *optconfig = CONFIGFILE;
3607
3608 time(&basetime); // start clock
3609
3610 // scan args
3611 while ((i = getopt(argc, argv, "dvc:h:")) >= 0)
3612 {
3613 switch (i)
3614 {
3615 case 'd':
3616 if (fork()) exit(0);
3617 setsid();
3618 freopen("/dev/null", "r", stdin);
3619 freopen("/dev/null", "w", stdout);
3620 freopen("/dev/null", "w", stderr);
3621 break;
3622 case 'v':
3623 optdebug++;
3624 break;
3625 case 'c':
3626 optconfig = optarg;
3627 break;
3628 case 'h':
3629 snprintf(hostname, sizeof(hostname), "%s", optarg);
3630 break;
3631 default:
3632 printf("Args are:\n"
3633 "\t-d\t\tDetach from terminal\n"
3634 "\t-c <file>\tConfig file\n"
3635 "\t-h <hostname>\tForce hostname\n"
3636 "\t-v\t\tDebug\n");
3637
3638 return (0);
3639 break;
3640 }
3641 }
3642
3643 // Start the timer routine off
3644 time(&time_now);
3645 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3646 signal(SIGALRM, sigalrm_handler);
3647 siginterrupt(SIGALRM, 0);
3648
3649 initplugins();
3650 initdata(optdebug, optconfig);
3651
3652 init_cli(hostname);
3653 read_config_file();
3654 init_tbf(config->num_tbfs);
3655
3656 LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
3657 LOG(0, 0, 0, "Copyright (c) 2003, 2004, 2005 Optus Internet Engineering\n");
3658 LOG(0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
3659 {
3660 struct rlimit rlim;
3661 rlim.rlim_cur = RLIM_INFINITY;
3662 rlim.rlim_max = RLIM_INFINITY;
3663 // Remove the maximum core size
3664 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
3665 LOG(0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
3666
3667 // Make core dumps go to /tmp
3668 chdir("/tmp");
3669 }
3670
3671 if (config->scheduler_fifo)
3672 {
3673 int ret;
3674 struct sched_param params = {0};
3675 params.sched_priority = 1;
3676
3677 if (get_nprocs() < 2)
3678 {
3679 LOG(0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
3680 config->scheduler_fifo = 0;
3681 }
3682 else
3683 {
3684 if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
3685 {
3686 LOG(1, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
3687 }
3688 else
3689 {
3690 LOG(0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
3691 config->scheduler_fifo = 0;
3692 }
3693 }
3694 }
3695
3696 /* Set up the cluster communications port. */
3697 if (cluster_init() < 0)
3698 exit(1);
3699
3700 #ifdef BGP
3701 signal(SIGPIPE, SIG_IGN);
3702 bgp_setup(config->as_number);
3703 bgp_add_route(config->bind_address, 0xffffffff);
3704 for (i = 0; i < BGP_NUM_PEERS; i++)
3705 {
3706 if (config->neighbour[i].name[0])
3707 bgp_start(&bgp_peers[i], config->neighbour[i].name,
3708 config->neighbour[i].as, config->neighbour[i].keepalive,
3709 config->neighbour[i].hold, 0); /* 0 = routing disabled */
3710 }
3711 #endif /* BGP */
3712
3713 inittun();
3714 LOG(1, 0, 0, "Set up on interface %s\n", config->tundevice);
3715
3716 initudp();
3717 initrad();
3718 initippool();
3719
3720 signal(SIGHUP, sighup_handler);
3721 signal(SIGTERM, sigterm_handler);
3722 signal(SIGINT, sigterm_handler);
3723 signal(SIGQUIT, sigquit_handler);
3724 signal(SIGCHLD, sigchild_handler);
3725
3726 // Prevent us from getting paged out
3727 if (config->lock_pages)
3728 {
3729 if (!mlockall(MCL_CURRENT))
3730 LOG(1, 0, 0, "Locking pages into memory\n");
3731 else
3732 LOG(0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
3733 }
3734
3735 alarm(1);
3736
3737 // Drop privileges here
3738 if (config->target_uid > 0 && geteuid() == 0)
3739 setuid(config->target_uid);
3740
3741 mainloop();
3742
3743 #ifdef BGP
3744 /* try to shut BGP down cleanly; with luck the sockets will be
3745 writable since we're out of the select */
3746 for (i = 0; i < BGP_NUM_PEERS; i++)
3747 if (bgp_peers[i].state == Established)
3748 bgp_stop(&bgp_peers[i]);
3749 #endif /* BGP */
3750
3751 /* remove plugins (so cleanup code gets run) */
3752 plugins_done();
3753
3754 // Remove the PID file if we wrote it
3755 if (config->wrote_pid && *config->pid_file == '/')
3756 unlink(config->pid_file);
3757
3758 /* kill CLI children */
3759 signal(SIGTERM, SIG_IGN);
3760 kill(0, SIGTERM);
3761 return 0;
3762 }
3763
3764 static void sighup_handler(int sig)
3765 {
3766 if (log_stream && log_stream != stderr)
3767 {
3768 fclose(log_stream);
3769 log_stream = NULL;
3770 }
3771
3772 read_config_file();
3773 }
3774
3775 static void sigalrm_handler(int sig)
3776 {
3777 // Log current traffic stats
3778
3779 snprintf(config->bandwidth, sizeof(config->bandwidth),
3780 "UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
3781 (udp_rx / 1024.0 / 1024.0 * 8),
3782 (eth_tx / 1024.0 / 1024.0 * 8),
3783 (eth_rx / 1024.0 / 1024.0 * 8),
3784 (udp_tx / 1024.0 / 1024.0 * 8),
3785 ((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
3786 udp_rx_pkt, eth_rx_pkt);
3787
3788 udp_tx = udp_rx = 0;
3789 udp_rx_pkt = eth_rx_pkt = 0;
3790 eth_tx = eth_rx = 0;
3791
3792 if (config->dump_speed)
3793 printf("%s\n", config->bandwidth);
3794
3795 // Update the internal time counter
3796 time(&time_now);
3797 strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
3798 alarm(1);
3799
3800 {
3801 // Run timer hooks
3802 struct param_timer p = { time_now };
3803 run_plugins(PLUGIN_TIMER, &p);
3804 }
3805
3806 }
3807
3808 static void sigterm_handler(int sig)
3809 {
3810 LOG(1, 0, 0, "Shutting down cleanly\n");
3811 main_quit++;
3812 }
3813
3814 static void sigquit_handler(int sig)
3815 {
3816 int i;
3817
3818 LOG(1, 0, 0, "Shutting down without saving sessions\n");
3819
3820 if (config->cluster_iam_master)
3821 {
3822 for (i = 1; i < MAXSESSION; i++)
3823 {
3824 if (session[i].opened)
3825 sessionkill(i, "L2TPNS Closing");
3826 }
3827 for (i = 1; i < MAXTUNNEL; i++)
3828 {
3829 if (tunnel[i].ip || tunnel[i].state)
3830 tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
3831 }
3832 }
3833
3834 main_quit++;
3835 }
3836
3837 static void sigchild_handler(int sig)
3838 {
3839 while (waitpid(-1, NULL, WNOHANG) > 0)
3840 ;
3841 }
3842
3843 static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
3844 {
3845 MD5_CTX ctx;
3846 *challenge_response = NULL;
3847
3848 if (!*config->l2tpsecret)
3849 {
3850 LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
3851 return;
3852 }
3853
3854 LOG(4, 0, 0, " Building challenge response for CHAP request\n");
3855
3856 *challenge_response = (char *)calloc(17, 1);
3857
3858 MD5Init(&ctx);
3859 MD5Update(&ctx, &id, 1);
3860 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
3861 MD5Update(&ctx, challenge, challenge_length);
3862 MD5Final(*challenge_response, &ctx);
3863
3864 return;
3865 }
3866
3867 static int facility_value(char *name)
3868 {
3869 int i;
3870 for (i = 0; facilitynames[i].c_name; i++)
3871 {
3872 if (strcmp(facilitynames[i].c_name, name) == 0)
3873 return facilitynames[i].c_val;
3874 }
3875 return 0;
3876 }
3877
3878 static void update_config()
3879 {
3880 int i;
3881 char *p;
3882 static int timeout = 0;
3883 static int interval = 0;
3884
3885 // Update logging
3886 closelog();
3887 syslog_log = 0;
3888 if (log_stream)
3889 {
3890 fclose(log_stream);
3891 log_stream = NULL;
3892 }
3893
3894 if (*config->log_filename)
3895 {
3896 if (strstr(config->log_filename, "syslog:") == config->log_filename)
3897 {
3898 char *p = config->log_filename + 7;
3899 if (*p)
3900 {
3901 openlog("l2tpns", LOG_PID, facility_value(p));
3902 syslog_log = 1;
3903 }
3904 }
3905 else if (strchr(config->log_filename, '/') == config->log_filename)
3906 {
3907 if ((log_stream = fopen((char *)(config->log_filename), "a")))
3908 {
3909 fseek(log_stream, 0, SEEK_END);
3910 setbuf(log_stream, NULL);
3911 }
3912 else
3913 {
3914 log_stream = stderr;
3915 setbuf(log_stream, NULL);
3916 }
3917 }
3918 }
3919 else
3920 {
3921 log_stream = stderr;
3922 setbuf(log_stream, NULL);
3923 }
3924
3925 // Update radius
3926 config->numradiusservers = 0;
3927 for (i = 0; i < MAXRADSERVER; i++)
3928 if (config->radiusserver[i])
3929 {
3930 config->numradiusservers++;
3931 // Set radius port: if not set, take the port from the
3932 // first radius server. For the first radius server,
3933 // take the #defined default value from l2tpns.h
3934
3935 // test twice, In case someone works with
3936 // a secondary radius server without defining
3937 // a primary one, this will work even then.
3938 if (i>0 && !config->radiusport[i])
3939 config->radiusport[i] = config->radiusport[i-1];
3940 if (!config->radiusport[i])
3941 config->radiusport[i] = RADPORT;
3942 }
3943
3944 if (!config->numradiusservers)
3945 LOG(0, 0, 0, "No RADIUS servers defined!\n");
3946
3947 config->num_radfds = 2 << RADIUS_SHIFT;
3948
3949 // parse radius_authtypes_s
3950 config->radius_authtypes = config->radius_authprefer = 0;
3951 p = config->radius_authtypes_s;
3952 while (*p)
3953 {
3954 char *s = strpbrk(p, " \t,");
3955 int type = 0;
3956
3957 if (s)
3958 {
3959 *s++ = 0;
3960 while (*s == ' ' || *s == '\t')
3961 s++;
3962
3963 if (!*s)
3964 s = 0;
3965 }
3966
3967 if (!strncasecmp("chap", p, strlen(p)))
3968 type = AUTHCHAP;
3969 else if (!strncasecmp("pap", p, strlen(p)))
3970 type = AUTHPAP;
3971 else
3972 LOG(0, 0, 0, "Invalid RADIUS authentication type \"%s\"", p);
3973
3974 config->radius_authtypes |= type;
3975 if (!config->radius_authprefer)
3976 config->radius_authprefer = type;
3977 }
3978
3979 if (!config->radius_authtypes)
3980 {
3981 LOG(0, 0, 0, "Defaulting to PAP authentication\n");
3982 config->radius_authtypes = config->radius_authprefer = AUTHPAP;
3983 }
3984
3985 // normalise radius_authtypes_s
3986 if (config->radius_authprefer == AUTHPAP)
3987 {
3988 strcpy(config->radius_authtypes_s, "pap");
3989 if (config->radius_authtypes & AUTHCHAP)
3990 strcat(config->radius_authtypes_s, ", chap");
3991 }
3992 else
3993 {
3994 strcpy(config->radius_authtypes_s, "chap");
3995 if (config->radius_authtypes & AUTHPAP)
3996 strcat(config->radius_authtypes_s, ", pap");
3997 }
3998
3999 // re-initialise the random number source
4000 initrandom(config->random_device);
4001
4002 // Update plugins
4003 for (i = 0; i < MAXPLUGINS; i++)
4004 {
4005 if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
4006 continue;
4007
4008 if (*config->plugins[i])
4009 {
4010 // Plugin added
4011 add_plugin(config->plugins[i]);
4012 }
4013 else if (*config->old_plugins[i])
4014 {
4015 // Plugin removed
4016 remove_plugin(config->old_plugins[i]);
4017 }
4018 }
4019
4020 memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
4021 if (!config->cleanup_interval) config->cleanup_interval = 10;
4022 if (!config->multi_read_count) config->multi_read_count = 10;
4023 if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
4024 if (!*config->cluster_interface)
4025 strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
4026
4027 if (!config->cluster_hb_interval)
4028 config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
4029
4030 if (!config->cluster_hb_timeout)
4031 config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
4032
4033 if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
4034 {
4035 // Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
4036 // late, ensure we're sufficiently larger than that
4037 int t = 4 * config->cluster_hb_interval + 11;
4038
4039 if (config->cluster_hb_timeout < t)
4040 {
4041 LOG(0, 0, 0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
4042 config->cluster_hb_timeout = t;
4043 }
4044
4045 // Push timing changes to the slaves immediately if we're the master
4046 if (config->cluster_iam_master)
4047 cluster_heartbeat();
4048
4049 interval = config->cluster_hb_interval;
4050 timeout = config->cluster_hb_timeout;
4051 }
4052
4053 // Write PID file
4054 if (*config->pid_file == '/' && !config->wrote_pid)
4055 {
4056 FILE *f;
4057 if ((f = fopen(config->pid_file, "w")))
4058 {
4059 fprintf(f, "%d\n", getpid());
4060 fclose(f);
4061 config->wrote_pid = 1;
4062 }
4063 else
4064 {
4065 LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
4066 }
4067 }
4068
4069 config->reload_config = 0;
4070 }
4071
4072 static void read_config_file()
4073 {
4074 FILE *f;
4075
4076 if (!config->config_file) return;
4077 if (!(f = fopen(config->config_file, "r")))
4078 {
4079 fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
4080 return;
4081 }
4082
4083 LOG(3, 0, 0, "Reading config file %s\n", config->config_file);
4084 cli_do_file(f);
4085 LOG(3, 0, 0, "Done reading config file\n");
4086 fclose(f);
4087 update_config();
4088 }
4089
4090 int sessionsetup(tunnelidt t, sessionidt s)
4091 {
4092 // A session now exists, set it up
4093 in_addr_t ip;
4094 char *user;
4095 sessionidt i;
4096 int r;
4097
4098 CSTAT(sessionsetup);
4099
4100 LOG(3, s, t, "Doing session setup for session\n");
4101
4102 if (!session[s].ip)
4103 {
4104 assign_ip_address(s);
4105 if (!session[s].ip)
4106 {
4107 LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
4108 sessionshutdown(s, "No IP addresses available");
4109 return 0;
4110 }
4111 LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
4112 fmtaddr(htonl(session[s].ip), 0));
4113 }
4114
4115
4116 // Make sure this is right
4117 session[s].tunnel = t;
4118
4119 // zap old sessions with same IP and/or username
4120 // Don't kill gardened sessions - doing so leads to a DoS
4121 // from someone who doesn't need to know the password
4122 {
4123 ip = session[s].ip;
4124 user = session[s].user;
4125 for (i = 1; i <= config->cluster_highest_sessionid; i++)
4126 {
4127 if (i == s) continue;
4128 if (ip == session[i].ip) sessionkill(i, "Duplicate IP address");
4129 if (!session[s].walled_garden && !session[i].walled_garden && strcasecmp(user, session[i].user) == 0)
4130 sessionkill(i, "Duplicate session for users");
4131 }
4132 }
4133
4134 {
4135 int routed = 0;
4136
4137 // Add the route for this session.
4138 for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
4139 {
4140 if ((session[s].ip & session[s].route[r].mask) ==
4141 (session[s].route[r].ip & session[s].route[r].mask))
4142 routed++;
4143
4144 routeset(s, session[s].route[r].ip, session[s].route[r].mask, 0, 1);
4145 }
4146
4147 // Static IPs need to be routed if not already
4148 // convered by a Framed-Route. Anything else is part
4149 // of the IP address pool and is already routed, it
4150 // just needs to be added to the IP cache.
4151 // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
4152 if (session[s].ip_pool_index == -1) // static ip
4153 {
4154 if (!routed) routeset(s, session[s].ip, 0, 0, 1);
4155 }
4156 else
4157 cache_ipmap(session[s].ip, s);
4158 }
4159
4160 if (!session[s].unique_id)
4161 {
4162 // did this session just finish radius?
4163 LOG(3, s, t, "Sending initial IPCP to client\n");
4164 sendipcp(t, s);
4165 session[s].unique_id = ++last_id;
4166 }
4167
4168 // Run the plugin's against this new session.
4169 {
4170 struct param_new_session data = { &tunnel[t], &session[s] };
4171 run_plugins(PLUGIN_NEW_SESSION, &data);
4172 }
4173
4174 // Allocate TBFs if throttled
4175 if (session[s].throttle_in || session[s].throttle_out)
4176 throttle_session(s, session[s].throttle_in, session[s].throttle_out);
4177
4178 session[s].last_packet = time_now;
4179
4180 LOG(2, s, t, "Login by %s at %s from %s (%s)\n", session[s].user,
4181 fmtaddr(htonl(session[s].ip), 0),
4182 fmtaddr(htonl(tunnel[t].ip), 1), tunnel[t].hostname);
4183
4184 cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
4185
4186 return 1; // RADIUS OK and IP allocated, done...
4187 }
4188
4189 //
4190 // This session just got dropped on us by the master or something.
4191 // Make sure our tables up up to date...
4192 //
4193 int load_session(sessionidt s, sessiont *new)
4194 {
4195 int i;
4196 int newip = 0;
4197
4198 // Sanity checks.
4199 if (new->ip_pool_index >= MAXIPPOOL ||
4200 new->tunnel >= MAXTUNNEL)
4201 {
4202 LOG(0, s, 0, "Strange session update received!\n");
4203 // FIXME! What to do here?
4204 return 0;
4205 }
4206
4207 //
4208 // Ok. All sanity checks passed. Now we're committed to
4209 // loading the new session.
4210 //
4211
4212 session[s].tunnel = new->tunnel; // For logging in cache_ipmap
4213
4214 // See if routes/ip cache need updating
4215 if (new->ip != session[s].ip)
4216 newip++;
4217
4218 for (i = 0; !newip && i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
4219 if (new->route[i].ip != session[s].route[i].ip ||
4220 new->route[i].mask != session[s].route[i].mask)
4221 newip++;
4222
4223 // needs update
4224 if (newip)
4225 {
4226 int routed = 0;
4227
4228 // remove old routes...
4229 for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
4230 {
4231 if ((session[s].ip & session[s].route[i].mask) ==
4232 (session[s].route[i].ip & session[s].route[i].mask))
4233 routed++;
4234
4235 routeset(s, session[s].route[i].ip, session[s].route[i].mask, 0, 0);
4236 }
4237
4238 // ...ip
4239 if (session[s].ip)
4240 {
4241 if (session[s].ip_pool_index == -1) // static IP
4242 {
4243 if (!routed) routeset(s, session[s].ip, 0, 0, 0);
4244 }
4245 else // It's part of the IP pool, remove it manually.
4246 uncache_ipmap(session[s].ip);
4247 }
4248
4249 routed = 0;
4250
4251 // add new routes...
4252 for (i = 0; i < MAXROUTE && new->route[i].ip; i++)
4253 {
4254 if ((new->ip & new->route[i].mask) ==
4255 (new->route[i].ip & new->route[i].mask))
4256 routed++;
4257
4258 routeset(s, new->route[i].ip, new->route[i].mask, 0, 1);
4259 }
4260
4261 // ...ip
4262 if (new->ip)
4263 {
4264 // If there's a new one, add it.
4265 if (new->ip_pool_index == -1)
4266 {
4267 if (!routed) routeset(s, new->ip, 0, 0, 1);
4268 }
4269 else
4270 cache_ipmap(new->ip, s);
4271 }
4272 }
4273
4274 // check v6 routing
4275 if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED))
4276 route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
4277
4278 // check filters
4279 if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
4280 {
4281 LOG(2, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
4282 new->filter_in = 0;
4283 }
4284
4285 if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
4286 {
4287 LOG(2, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
4288 new->filter_out = 0;
4289 }
4290
4291 if (new->filter_in != session[s].filter_in)
4292 {
4293 if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
4294 if (new->filter_in) ip_filters[new->filter_in - 1].used++;
4295 }
4296
4297 if (new->filter_out != session[s].filter_out)
4298 {
4299 if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
4300 if (new->filter_out) ip_filters[new->filter_out - 1].used++;
4301 }
4302
4303 if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
4304 // for walking the sessions to forward byte counts to the master.
4305 config->cluster_highest_sessionid = s;
4306
4307 // TEMP: old session struct used a uint32_t to define the throttle
4308 // speed for both up/down, new uses a uint16_t for each. Deal with
4309 // sessions from an old master for migration.
4310 if (new->throttle_out == 0 && new->tbf_out)
4311 new->throttle_out = new->throttle_in;
4312
4313 memcpy(&session[s], new, sizeof(session[s])); // Copy over..
4314
4315 // Do fixups into address pool.
4316 if (new->ip_pool_index != -1)
4317 fix_address_pool(s);
4318
4319 return 1;
4320 }
4321
4322 static void initplugins()
4323 {
4324 int i;
4325
4326 loaded_plugins = ll_init();
4327 // Initialize the plugins to nothing
4328 for (i = 0; i < MAX_PLUGIN_TYPES; i++)
4329 plugins[i] = ll_init();
4330 }
4331
4332 static void *open_plugin(char *plugin_name, int load)
4333 {
4334 char path[256] = "";
4335
4336 snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
4337 LOG(2, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
4338 return dlopen(path, RTLD_NOW);
4339 }
4340
4341 // plugin callback to get a config value
4342 static void *getconfig(char *key, enum config_typet type)
4343 {
4344 int i;
4345
4346 for (i = 0; config_values[i].key; i++)
4347 {
4348 if (!strcmp(config_values[i].key, key))
4349 {
4350 if (config_values[i].type == type)
4351 return ((void *) config) + config_values[i].offset;
4352
4353 LOG(1, 0, 0, "plugin requested config item \"%s\" expecting type %d, have type %d\n",
4354 key, type, config_values[i].type);
4355
4356 return 0;
4357 }
4358 }
4359
4360 LOG(1, 0, 0, "plugin requested unknown config item \"%s\"\n", key);
4361 return 0;
4362 }
4363
4364 static int add_plugin(char *plugin_name)
4365 {
4366 static struct pluginfuncs funcs = {
4367 _log,
4368 _log_hex,
4369 fmtaddr,
4370 sessionbyuser,
4371 sessiontbysessionidt,
4372 sessionidtbysessiont,
4373 radiusnew,
4374 radiussend,
4375 getconfig,
4376 sessionkill,
4377 throttle_session,
4378 cluster_send_session,
4379 };
4380
4381 void *p = open_plugin(plugin_name, 1);
4382 int (*initfunc)(struct pluginfuncs *);
4383 int i;
4384
4385 if (!p)
4386 {
4387 LOG(1, 0, 0, " Plugin load failed: %s\n", dlerror());
4388 return -1;
4389 }
4390
4391 if (ll_contains(loaded_plugins, p))
4392 {
4393 dlclose(p);
4394 return 0; // already loaded
4395 }
4396
4397 {
4398 int *v = dlsym(p, "plugin_api_version");
4399 if (!v || *v != PLUGIN_API_VERSION)
4400 {
4401 LOG(1, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
4402 dlclose(p);
4403 return -1;
4404 }
4405 }
4406
4407 if ((initfunc = dlsym(p, "plugin_init")))
4408 {
4409 if (!initfunc(&funcs))
4410 {
4411 LOG(1, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
4412 dlclose(p);
4413 return -1;
4414 }
4415 }
4416
4417 ll_push(loaded_plugins, p);
4418
4419 for (i = 0; i < max_plugin_functions; i++)
4420 {
4421 void *x;
4422 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4423 {
4424 LOG(3, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
4425 ll_push(plugins[i], x);
4426 }
4427 }
4428
4429 LOG(2, 0, 0, " Loaded plugin %s\n", plugin_name);
4430 return 1;
4431 }
4432
4433 static void run_plugin_done(void *plugin)
4434 {
4435 int (*donefunc)(void) = dlsym(plugin, "plugin_done");
4436
4437 if (donefunc)
4438 donefunc();
4439 }
4440
4441 static int remove_plugin(char *plugin_name)
4442 {
4443 void *p = open_plugin(plugin_name, 0);
4444 int loaded = 0;
4445
4446 if (!p)
4447 return -1;
4448
4449 if (ll_contains(loaded_plugins, p))
4450 {
4451 int i;
4452 for (i = 0; i < max_plugin_functions; i++)
4453 {
4454 void *x;
4455 if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
4456 ll_delete(plugins[i], x);
4457 }
4458
4459 ll_delete(loaded_plugins, p);
4460 run_plugin_done(p);
4461 loaded = 1;
4462 }
4463
4464 dlclose(p);
4465 LOG(2, 0, 0, "Removed plugin %s\n", plugin_name);
4466 return loaded;
4467 }
4468
4469 int run_plugins(int plugin_type, void *data)
4470 {
4471 int (*func)(void *data);
4472
4473 if (!plugins[plugin_type] || plugin_type > max_plugin_functions)
4474 return PLUGIN_RET_ERROR;
4475
4476 ll_reset(plugins[plugin_type]);
4477 while ((func = ll_next(plugins[plugin_type])))
4478 {
4479 int r = func(data);
4480
4481 if (r != PLUGIN_RET_OK)
4482 return r; // stop here
4483 }
4484
4485 return PLUGIN_RET_OK;
4486 }
4487
4488 static void plugins_done()
4489 {
4490 void *p;
4491
4492 ll_reset(loaded_plugins);
4493 while ((p = ll_next(loaded_plugins)))
4494 run_plugin_done(p);
4495 }
4496
4497 static void processcontrol(uint8_t * buf, int len, struct sockaddr_in *addr, int alen)
4498 {
4499 struct nsctl request;
4500 struct nsctl response;
4501 int type = unpack_control(&request, buf, len);
4502 int r;
4503 void *p;
4504
4505 if (log_stream && config->debug >= 4)
4506 {
4507 if (type < 0)
4508 {
4509 LOG(4, 0, 0, "Bogus control message from %s (%d)\n",
4510 fmtaddr(addr->sin_addr.s_addr, 0), type);
4511 }
4512 else
4513 {
4514 LOG(4, 0, 0, "Received [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4515 dump_control(&request, log_stream);
4516 }
4517 }
4518
4519 switch (type)
4520 {
4521 case NSCTL_REQ_LOAD:
4522 if (request.argc != 1)
4523 {
4524 response.type = NSCTL_RES_ERR;
4525 response.argc = 1;
4526 response.argv[0] = "name of plugin required";
4527 }
4528 else if ((r = add_plugin(request.argv[0])) < 1)
4529 {
4530 response.type = NSCTL_RES_ERR;
4531 response.argc = 1;
4532 response.argv[0] = !r
4533 ? "plugin already loaded"
4534 : "error loading plugin";
4535 }
4536 else
4537 {
4538 response.type = NSCTL_RES_OK;
4539 response.argc = 0;
4540 }
4541
4542 break;
4543
4544 case NSCTL_REQ_UNLOAD:
4545 if (request.argc != 1)
4546 {
4547 response.type = NSCTL_RES_ERR;
4548 response.argc = 1;
4549 response.argv[0] = "name of plugin required";
4550 }
4551 else if ((r = remove_plugin(request.argv[0])) < 1)
4552 {
4553 response.type = NSCTL_RES_ERR;
4554 response.argc = 1;
4555 response.argv[0] = !r
4556 ? "plugin not loaded"
4557 : "plugin not found";
4558 }
4559 else
4560 {
4561 response.type = NSCTL_RES_OK;
4562 response.argc = 0;
4563 }
4564
4565 break;
4566
4567 case NSCTL_REQ_HELP:
4568 response.type = NSCTL_RES_OK;
4569 response.argc = 0;
4570
4571 ll_reset(loaded_plugins);
4572 while ((p = ll_next(loaded_plugins)))
4573 {
4574 char **help = dlsym(p, "plugin_control_help");
4575 while (response.argc < 0xff && help && *help)
4576 response.argv[response.argc++] = *help++;
4577 }
4578
4579 break;
4580
4581 case NSCTL_REQ_CONTROL:
4582 {
4583 struct param_control param = {
4584 config->cluster_iam_master,
4585 request.argc,
4586 request.argv,
4587 0,
4588 NULL,
4589 };
4590
4591 int r = run_plugins(PLUGIN_CONTROL, &param);
4592
4593 if (r == PLUGIN_RET_ERROR)
4594 {
4595 response.type = NSCTL_RES_ERR;
4596 response.argc = 1;
4597 response.argv[0] = param.additional
4598 ? param.additional
4599 : "error returned by plugin";
4600 }
4601 else if (r == PLUGIN_RET_NOTMASTER)
4602 {
4603 static char msg[] = "must be run on master: 000.000.000.000";
4604
4605 response.type = NSCTL_RES_ERR;
4606 response.argc = 1;
4607 if (config->cluster_master_address)
4608 {
4609 strcpy(msg + 23, fmtaddr(config->cluster_master_address, 0));
4610 response.argv[0] = msg;
4611 }
4612 else
4613 {
4614 response.argv[0] = "must be run on master: none elected";
4615 }
4616 }
4617 else if (!(param.response & NSCTL_RESPONSE))
4618 {
4619 response.type = NSCTL_RES_ERR;
4620 response.argc = 1;
4621 response.argv[0] = param.response
4622 ? "unrecognised response value from plugin"
4623 : "unhandled action";
4624 }
4625 else
4626 {
4627 response.type = param.response;
4628 response.argc = 0;
4629 if (param.additional)
4630 {
4631 response.argc = 1;
4632 response.argv[0] = param.additional;
4633 }
4634 }
4635 }
4636
4637 break;
4638
4639 default:
4640 response.type = NSCTL_RES_ERR;
4641 response.argc = 1;
4642 response.argv[0] = "error unpacking control packet";
4643 }
4644
4645 buf = calloc(NSCTL_MAX_PKT_SZ, 1);
4646 if (!buf)
4647 {
4648 LOG(2, 0, 0, "Failed to allocate nsctl response\n");
4649 return;
4650 }
4651
4652 r = pack_control(buf, NSCTL_MAX_PKT_SZ, response.type, response.argc, response.argv);
4653 if (r > 0)
4654 {
4655 sendto(controlfd, buf, r, 0, (const struct sockaddr *) addr, alen);
4656 if (log_stream && config->debug >= 4)
4657 {
4658 LOG(4, 0, 0, "Sent [%s] ", fmtaddr(addr->sin_addr.s_addr, 0));
4659 dump_control(&response, log_stream);
4660 }
4661 }
4662 else
4663 LOG(2, 0, 0, "Failed to pack nsctl response for %s (%d)\n",
4664 fmtaddr(addr->sin_addr.s_addr, 0), r);
4665
4666 free(buf);
4667 }
4668
4669 static tunnelidt new_tunnel()
4670 {
4671 tunnelidt i;
4672 for (i = 1; i < MAXTUNNEL; i++)
4673 {
4674 if (tunnel[i].state == TUNNELFREE)
4675 {
4676 LOG(4, 0, i, "Assigning tunnel ID %d\n", i);
4677 if (i > config->cluster_highest_tunnelid)
4678 config->cluster_highest_tunnelid = i;
4679 return i;
4680 }
4681 }
4682 LOG(0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
4683 return 0;
4684 }
4685
4686 //
4687 // We're becoming the master. Do any required setup..
4688 //
4689 // This is principally telling all the plugins that we're
4690 // now a master, and telling them about all the sessions
4691 // that are active too..
4692 //
4693 void become_master(void)
4694 {
4695 int s, i;
4696 run_plugins(PLUGIN_BECOME_MASTER, NULL);
4697
4698 // running a bunch of iptables commands is slow and can cause
4699 // the master to drop tunnels on takeover--kludge around the
4700 // problem by forking for the moment (note: race)
4701 if (!fork_and_close())
4702 {
4703 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4704 {
4705 if (!session[s].opened) // Not an in-use session.
4706 continue;
4707
4708 run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
4709 }
4710 exit(0);
4711 }
4712
4713 // add radius fds
4714 for (i = 0; i < config->num_radfds; i++)
4715 {
4716 FD_SET(radfds[i], &readset);
4717 if (radfds[i] > readset_n)
4718 readset_n = radfds[i];
4719 }
4720 }
4721
4722 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
4723 {
4724 int s, i;
4725 int count = 0;
4726 int buckets[64];
4727
4728 if (CLI_HELP_REQUESTED)
4729 return CLI_HELP_NO_ARGS;
4730
4731 time(&time_now);
4732 for (i = 0; i < 64;++i) buckets[i] = 0;
4733
4734 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4735 {
4736 int idle;
4737 if (!session[s].opened)
4738 continue;
4739
4740 idle = time_now - session[s].last_packet;
4741 idle /= 5 ; // In multiples of 5 seconds.
4742 if (idle < 0)
4743 idle = 0;
4744 if (idle > 63)
4745 idle = 63;
4746
4747 ++count;
4748 ++buckets[idle];
4749 }
4750
4751 for (i = 0; i < 63; ++i)
4752 {
4753 cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
4754 }
4755 cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
4756 cli_print(cli, "%d total sessions open.", count);
4757 return CLI_OK;
4758 }
4759
4760 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
4761 {
4762 int s, i;
4763 int count = 0;
4764 int buckets[64];
4765
4766 if (CLI_HELP_REQUESTED)
4767 return CLI_HELP_NO_ARGS;
4768
4769 time(&time_now);
4770 for (i = 0; i < 64;++i) buckets[i] = 0;
4771
4772 for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
4773 {
4774 int open = 0, d;
4775 if (!session[s].opened)
4776 continue;
4777
4778 d = time_now - session[s].opened;
4779 if (d < 0)
4780 d = 0;
4781 while (d > 1 && open < 32)
4782 {
4783 ++open;
4784 d >>= 1; // half.
4785 }
4786 ++count;
4787 ++buckets[open];
4788 }
4789
4790 s = 1;
4791 for (i = 0; i < 30; ++i)
4792 {
4793 cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
4794 s <<= 1;
4795 }
4796 cli_print(cli, "%d total sessions open.", count);
4797 return CLI_OK;
4798 }
4799
4800 /* Unhide an avp.
4801 *
4802 * This unencodes the AVP using the L2TP secret and the previously
4803 * stored random vector. It overwrites the hidden data with the
4804 * unhidden AVP subformat.
4805 */
4806 static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
4807 {
4808 MD5_CTX ctx;
4809 uint8_t digest[16];
4810 uint8_t *last;
4811 size_t d = 0;
4812
4813 // Compute initial pad
4814 MD5Init(&ctx);
4815 MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
4816 MD5Update(&ctx, (uint8_t) type & 0xff, 1);
4817 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4818 MD5Update(&ctx, vector, vec_len);
4819 MD5Final(digest, &ctx);
4820
4821 // pointer to last decoded 16 octets
4822 last = value;
4823
4824 while (len > 0)
4825 {
4826 // calculate a new pad based on the last decoded block
4827 if (d >= sizeof(digest))
4828 {
4829 MD5Init(&ctx);
4830 MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
4831 MD5Update(&ctx, last, sizeof(digest));
4832 MD5Final(digest, &ctx);
4833
4834 d = 0;
4835 last = value;
4836 }
4837
4838 *value++ ^= digest[d++];
4839 len--;
4840 }
4841 }
4842
4843 static int ip_filter_port(ip_filter_portt *p, uint16_t port)
4844 {
4845 switch (p->op)
4846 {
4847 case FILTER_PORT_OP_EQ: return port == p->port;
4848 case FILTER_PORT_OP_NEQ: return port != p->port;
4849 case FILTER_PORT_OP_GT: return port > p->port;
4850 case FILTER_PORT_OP_LT: return port < p->port;
4851 case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
4852 }
4853
4854 return 0;
4855 }
4856
4857 static int ip_filter_flag(uint8_t op, uint8_t sflags, uint8_t cflags, uint8_t flags)
4858 {
4859 switch (op)
4860 {
4861 case FILTER_FLAG_OP_ANY:
4862 return (flags & sflags) || (~flags & cflags);
4863
4864 case FILTER_FLAG_OP_ALL:
4865 return (flags & sflags) == sflags && (~flags & cflags) == cflags;
4866
4867 case FILTER_FLAG_OP_EST:
4868 return (flags & (TCP_FLAG_ACK|TCP_FLAG_RST)) && (~flags & TCP_FLAG_SYN);
4869 }
4870
4871 return 0;
4872 }
4873
4874 int ip_filter(uint8_t *buf, int len, uint8_t filter)
4875 {
4876 uint16_t frag_offset;
4877 uint8_t proto;
4878 in_addr_t src_ip;
4879 in_addr_t dst_ip;
4880 uint16_t src_port = 0;
4881 uint16_t dst_port = 0;
4882 uint8_t flags = 0;
4883 ip_filter_rulet *rule;
4884
4885 if (len < 20) // up to end of destination address
4886 return 0;
4887
4888 if ((*buf >> 4) != 4) // IPv4
4889 return 0;
4890
4891 frag_offset = ntohs(*(uint16_t *) (buf + 6)) & 0x1fff;
4892 proto = buf[9];
4893 src_ip = *(in_addr_t *) (buf + 12);
4894 dst_ip = *(in_addr_t *) (buf + 16);
4895
4896 if (frag_offset == 0 && (proto == IPPROTO_TCP || proto == IPPROTO_UDP))
4897 {
4898 int l = (buf[0] & 0xf) * 4; // length of IP header
4899 if (len < l + 4) // ports
4900 return 0;
4901
4902 src_port = ntohs(*(uint16_t *) (buf + l));
4903 dst_port = ntohs(*(uint16_t *) (buf + l + 2));
4904 if (proto == IPPROTO_TCP)
4905 {
4906 if (len < l + 14) // flags
4907 return 0;
4908
4909 flags = buf[l + 13] & 0x3f;
4910 }
4911 }
4912
4913 for (rule = ip_filters[filter].rules; rule->action; rule++)
4914 {
4915 if (rule->proto != IPPROTO_IP && proto != rule->proto)
4916 continue;
4917
4918 if (rule->src_wild != INADDR_BROADCAST &&
4919 (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
4920 continue;
4921
4922 if (rule->dst_wild != INADDR_BROADCAST &&
4923 (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
4924 continue;
4925
4926 if (frag_offset)
4927 {
4928 if (!rule->frag || rule->action == FILTER_ACTION_DENY)
4929 continue;
4930 }
4931 else
4932 {
4933 if (rule->frag)
4934 continue;
4935
4936 if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
4937 {
4938 if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
4939 continue;
4940
4941 if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
4942 continue;
4943
4944 if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
4945 !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
4946 continue;
4947 }
4948 }
4949
4950 // matched
4951 rule->counter++;
4952 return rule->action == FILTER_ACTION_PERMIT;
4953 }
4954
4955 // default deny
4956 return 0;
4957 }