add filtering
[l2tpns.git] / l2tpns.h
1 // L2TPNS Global Stuff
2 // $Id: l2tpns.h,v 1.40 2004/11/28 20:10:04 bodea Exp $
3
4 #ifndef __L2TPNS_H__
5 #define __L2TPNS_H__
6
7 #include <netinet/in.h>
8 #include <execinfo.h>
9 #include <stdio.h>
10 #include <signal.h>
11 #include <stdlib.h>
12 #include <netinet/in.h>
13 #include <sys/socket.h>
14 #include <arpa/inet.h>
15 #include <sys/types.h>
16 #include <libcli.h>
17
18 #define VERSION "2.0.9"
19
20 // Limits
21 #define MAXTUNNEL 500 // could be up to 65535
22 #define MAXSESSION 50000 // could be up to 65535
23 #define MAXTBFS 6000 // Maximum token bucket filters. Might need up to 2 * session.
24
25 #define RADIUS_SHIFT 5
26 #define RADIUS_MASK ((unsigned short)(((unsigned short)~0) >> (16 - RADIUS_SHIFT)))
27 #define MAXRADIUS ((unsigned long)(1L << RADIUS_SHIFT) * 255)
28
29 #define T_UNDEF (0xffff) // A tunnel ID that won't ever be used. Mark session as undefined.
30 #define T_FREE (0) // A tunnel ID that won't ever be used. Mark session as free.
31
32 #define MAXCONTROL 1000 // max length control message we ever send...
33 #define MAXETHER (1500+18) // max packet we try sending to tun
34 #define MAXTEL 96 // telephone number
35 #define MAXPLUGINS 20 // maximum number of plugins to load
36 #define MAXRADSERVER 10 // max radius servers
37 #define MAXROUTE 10 // max static routes per session
38 #define MAXIPPOOL 131072 // max number of ip addresses in pool
39 #define RINGBUFFER_SIZE 10000 // Number of ringbuffer entries to allocate
40 #define MAX_LOG_LENGTH 512 // Maximum size of log message
41 #define ECHO_TIMEOUT 60 // Time between last packet sent and LCP ECHO generation
42 #define IDLE_TIMEOUT 240 // Time between last packet sent and LCP ECHO generation
43 #define BUSY_WAIT_TIME 3000 // 5 minutes in 1/10th seconds to wait for radius to cleanup on shutdown
44
45 // Constants
46 #ifndef ETCDIR
47 #define ETCDIR "/etc/l2tpns"
48 #endif
49
50 #ifndef LIBDIR
51 #define LIBDIR "/usr/lib/l2tpns"
52 #endif
53
54 #ifndef STATEDIR
55 #define STATEDIR "/var/lib/l2tpns"
56 #endif
57
58 #ifndef PLUGINDIR
59 #define PLUGINDIR LIBDIR // Plugins
60 #endif
61
62 #ifndef PLUGINCONF
63 #define PLUGINCONF ETCDIR // Plugin config dir
64 #endif
65
66 #ifndef FLASHDIR
67 #define FLASHDIR ETCDIR
68 #endif
69
70 #ifndef DATADIR
71 #define DATADIR STATEDIR
72 #endif
73
74 #define TUNDEVICE "/dev/net/tun"
75 #define STATEFILE DATADIR "/state.dump" // State dump file
76 #define CONFIGFILE FLASHDIR "/startup-config" // Configuration file
77 #define CLIUSERS FLASHDIR "/users" // CLI Users file
78 #define IPPOOLFILE FLASHDIR "/ip_pool" // Address pool configuration
79 #define ACCT_TIME 3000 // 5 minute accounting interval
80 #define L2TPPORT 1701 // L2TP port
81 #define RADPORT 1645 // old radius port...
82 #define PKTARP 0x0806 // ARP packet type
83 #define PKTIP 0x0800 // IP packet type
84 #define PSEUDOMAC 0x0200 // pseudo MAC prefix (local significant MAC)
85 #define PPPPAP 0xC023
86 #define PPPCHAP 0xC223
87 #define PPPLCP 0xC021
88 #define PPPIPCP 0x8021
89 #define PPPCCP 0x80FD
90 #define PPPIP 0x0021
91 #define PPPMP 0x003D
92 #define MIN_IP_SIZE 0x19
93 enum
94 {
95 ConfigReq = 1,
96 ConfigAck,
97 ConfigNak,
98 ConfigRej,
99 TerminateReq,
100 TerminateAck,
101 CodeRej,
102 ProtocolRej,
103 EchoReq,
104 EchoReply,
105 DiscardRequest,
106 IdentRequest
107 };
108
109 // Types
110 typedef unsigned short u16;
111 typedef unsigned int u32;
112 typedef unsigned char u8;
113 typedef u32 ipt;
114 typedef u16 portt;
115 typedef u16 sessionidt;
116 typedef u16 tunnelidt;
117 typedef u32 clockt;
118 typedef u8 hasht[16];
119
120 // CLI actions
121 struct cli_session_actions {
122 char action;
123 ipt snoop_ip;
124 u16 snoop_port;
125 int throttle_in;
126 int throttle_out;
127 int filter_in;
128 int filter_out;
129 };
130
131 #define CLI_SESS_KILL 0x01
132 #define CLI_SESS_SNOOP 0x02
133 #define CLI_SESS_NOSNOOP 0x04
134 #define CLI_SESS_THROTTLE 0x08
135 #define CLI_SESS_NOTHROTTLE 0x10
136 #define CLI_SESS_FILTER 0x20
137 #define CLI_SESS_NOFILTER 0x40
138
139 struct cli_tunnel_actions {
140 char action;
141 };
142
143 #define CLI_TUN_KILL 0x01
144
145 // dump header: update number if internal format changes
146 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
147
148 // structures
149 typedef struct // route
150 {
151 ipt ip;
152 ipt mask;
153 }
154 routet;
155
156 typedef struct controls // control message
157 {
158 struct controls *next; // next in queue
159 u16 length; // length
160 u8 buf[MAXCONTROL];
161 }
162 controlt;
163
164 typedef struct
165 {
166 sessionidt next; // next session in linked list
167 sessionidt far; // far end session ID
168 tunnelidt tunnel; // near end tunnel ID
169 ipt ip; // IP of session set by RADIUS response (host byte order).
170 int ip_pool_index; // index to IP pool
171 unsigned long unique_id; // unique session id
172 u16 nr; // next receive
173 u16 ns; // next send
174 u32 magic; // ppp magic number
175 u32 cin, cout; // byte counts
176 u32 pin, pout; // packet counts
177 u32 total_cin; // This counter is never reset while a session is open
178 u32 total_cout; // This counter is never reset while a session is open
179 u32 id; // session id
180 u16 throttle_in; // upstream throttle rate (kbps)
181 u16 throttle_out; // downstream throttle rate
182 clockt opened; // when started
183 clockt die; // being closed, when to finally free
184 time_t last_packet; // Last packet from the user (used for idle timeouts)
185 ipt dns1, dns2; // DNS servers
186 routet route[MAXROUTE]; // static routes
187 u16 radius; // which radius session is being used (0 for not waiting on authentication)
188 u16 mru; // maximum receive unit
189 u16 tbf_in; // filter bucket for throttling in from the user.
190 u16 tbf_out; // filter bucket for throttling out to the user.
191 u8 l2tp_flags; // various bit flags from the ICCN on the l2tp tunnel.
192 u8 reserved_old_snoop; // No longer used - remove at some time
193 u8 walled_garden; // is this session gardened?
194 u8 flags1; // additional flags (currently unused);
195 char random_vector[MAXTEL];
196 int random_vector_length;
197 char user[129]; // user (needed in seesion for radius stop messages) (can we reduce this? --mo)
198 char called[MAXTEL]; // called number
199 char calling[MAXTEL]; // calling number
200 u32 tx_connect_speed;
201 u32 rx_connect_speed;
202 u32 flags; // Various session flags.
203 ipt snoop_ip; // Interception destination IP
204 u16 snoop_port; // Interception destination port
205 u16 sid; // near end session id.
206 u8 filter_in; // input filter index (to ip_filters[N-1]; 0 if none)
207 u8 filter_out; // output filter index
208 char reserved[18]; // Space to expand structure without changing HB_VERSION
209 }
210 sessiont;
211
212 #define SF_IPCP_ACKED 1 // Has this session seen an IPCP Ack?
213 #define SF_LCP_ACKED 2 // LCP negotiated
214 #define SF_CCP_ACKED 4 // CCP negotiated
215
216 typedef struct
217 {
218 u32 cin;
219 u32 cout;
220 } sessioncountt;
221
222 #define SESSIONPFC 1 // PFC negotiated flags
223 #define SESSIONACFC 2 // ACFC negotiated flags
224
225 // 168 bytes per tunnel
226 typedef struct
227 {
228 tunnelidt far; // far end tunnel ID
229 ipt ip; // Ip for far end
230 portt port; // port for far end
231 u16 window; // Rx window
232 u16 nr; // next receive
233 u16 ns; // next send
234 int state; // current state (tunnelstate enum)
235 clockt last; // when last control message sent (used for resend timeout)
236 clockt retry; // when to try resenting pending control
237 clockt die; // being closed, when to finally free
238 clockt lastrec; // when the last control message was received
239 char hostname[128]; // tunnel hostname
240 char vendor[128]; // LAC vendor
241 u8 try; // number of retrys on a control message
242 u16 controlc; // outstaind messages in queue
243 controlt *controls; // oldest message
244 controlt *controle; // newest message
245 }
246 tunnelt;
247
248 // 180 bytes per radius session
249 typedef struct // outstanding RADIUS requests
250 {
251 sessionidt session; // which session this applies to
252 hasht auth; // request authenticator
253 clockt retry; // when to try next
254 char calling[MAXTEL]; // calling number
255 char pass[129]; // password
256 u8 id; // ID for PPP response
257 u8 try; // which try we are on
258 u8 state; // state of radius requests
259 u8 chap; // set if CHAP used (is CHAP identifier)
260 }
261 radiust;
262
263 typedef struct
264 {
265 ipt address; // Host byte order..
266 char assigned; // 1 if assigned, 0 if free
267 sessionidt session;
268 clockt last; // last used
269 char user[129]; // user (try to have ip addresses persistent)
270 }
271 ippoolt;
272
273 #ifdef RINGBUFFER
274 struct Tringbuffer
275 {
276 struct {
277 char level;
278 sessionidt session;
279 tunnelidt tunnel;
280 ipt address;
281 char message[MAX_LOG_LENGTH];
282 } buffer[RINGBUFFER_SIZE];
283 int head;
284 int tail;
285 };
286 #endif
287
288 /*
289 * Possible tunnel states
290 * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
291 */
292 enum
293 {
294 TUNNELFREE, // Not in use
295 TUNNELOPEN, // Active tunnel
296 TUNNELDIE, // Currently closing
297 TUNNELOPENING, // Busy opening
298 TUNNELUNDEF, // Undefined
299 };
300
301 enum
302 {
303 RADIUSNULL, // Not in use
304 RADIUSCHAP, // sending CHAP down PPP
305 RADIUSAUTH, // sending auth to RADIUS server
306 RADIUSIPCP, // sending IPCP to end user
307 RADIUSSTART, // sending start accounting to RADIUS server
308 RADIUSSTOP, // sending stop accounting to RADIUS server
309 RADIUSWAIT, // waiting timeout before available, in case delayed replies
310 RADIUSDEAD, // errored while talking to radius server.
311 };
312
313 struct Tstats
314 {
315 time_t start_time;
316 time_t last_reset;
317
318 unsigned long tun_rx_packets;
319 unsigned long tun_tx_packets;
320 unsigned long tun_rx_bytes;
321 unsigned long tun_tx_bytes;
322 unsigned long tun_rx_errors;
323 unsigned long tun_tx_errors;
324
325 unsigned long tunnel_rx_packets;
326 unsigned long tunnel_tx_packets;
327 unsigned long tunnel_rx_bytes;
328 unsigned long tunnel_tx_bytes;
329 unsigned long tunnel_rx_errors;
330 unsigned long tunnel_tx_errors;
331
332 unsigned long tunnel_retries;
333 unsigned long radius_retries;
334
335 unsigned long arp_sent;
336
337 unsigned long packets_snooped;
338
339 unsigned long tunnel_created;
340 unsigned long session_created;
341 unsigned long tunnel_timeout;
342 unsigned long session_timeout;
343 unsigned long radius_timeout;
344 unsigned long radius_overflow;
345 unsigned long tunnel_overflow;
346 unsigned long session_overflow;
347
348 unsigned long ip_allocated;
349 unsigned long ip_freed;
350
351 unsigned long c_forwarded;
352 unsigned long recv_forward;
353 #ifdef STATISTICS
354 unsigned long call_processtun;
355 unsigned long call_processipout;
356 unsigned long call_processudp;
357 unsigned long call_sessionbyip;
358 unsigned long call_sessionbyuser;
359 unsigned long call_sendarp;
360 unsigned long call_sendipcp;
361 unsigned long call_tunnelsend;
362 unsigned long call_sessionkill;
363 unsigned long call_sessionshutdown;
364 unsigned long call_tunnelkill;
365 unsigned long call_tunnelshutdown;
366 unsigned long call_assign_ip_address;
367 unsigned long call_free_ip_address;
368 unsigned long call_dump_acct_info;
369 unsigned long call_sessionsetup;
370 unsigned long call_processpap;
371 unsigned long call_processchap;
372 unsigned long call_processlcp;
373 unsigned long call_processipcp;
374 unsigned long call_processipin;
375 unsigned long call_processccp;
376 unsigned long call_sendchap;
377 unsigned long call_processrad;
378 unsigned long call_radiussend;
379 unsigned long call_radiusretry;
380 #endif
381 };
382
383 #ifdef STATISTICS
384
385 #ifdef STAT_CALLS
386 #define CSTAT(x) STAT(x)
387 #else
388 #define CSTAT(x)
389 #endif
390
391 #define STAT(x) (_statistics->x++)
392 #define INC_STAT(x,y) (_statistics->x += (y))
393 #define GET_STAT(x) (_statistics->x)
394 #define SET_STAT(x, y) (_statistics->x = (y))
395 #else
396 #define CSTAT(x)
397 #define STAT(x)
398 #define INC_STAT(x,y)
399 #define GET_STAT(x) 0
400 #define SET_STAT(x, y)
401 #endif
402
403 typedef struct
404 {
405 int debug; // debugging level
406 time_t start_time; // time when l2tpns was started
407 char bandwidth[256]; // current bandwidth
408 char pid_file[256]; // file to write PID to on startup
409 int wrote_pid;
410 clockt current_time; // 1/10ths of a second since the process started.
411 // means that we can only run a given process
412 // for 13 years without re-starting!
413
414 char config_file[128];
415 int reload_config; // flag to re-read config (set by cli)
416 int cleanup_interval; // interval between regular cleanups (in seconds)
417 int multi_read_count; // amount of packets to read per fd in processing loop
418
419 char tundevice[10]; // tun device name
420 char log_filename[128];
421 char l2tpsecret[64];
422
423 char radiussecret[64];
424 int radius_accounting;
425 ipt radiusserver[MAXRADSERVER]; // radius servers
426 u16 radiusport[MAXRADSERVER]; // radius base ports
427 u8 numradiusservers; // radius server count
428 short num_radfds; // Number of radius filehandles allocated
429
430 ipt default_dns1, default_dns2;
431
432 unsigned long rl_rate; // default throttle rate
433 int num_tbfs; // number of throttle buckets
434
435 int save_state;
436 char accounting_dir[128];
437 ipt bind_address;
438 ipt peer_address;
439 int send_garp; // Set to true to garp for vip address on startup
440
441 int target_uid;
442 int dump_speed;
443 char plugins[64][MAXPLUGINS];
444 char old_plugins[64][MAXPLUGINS];
445
446 int next_tbf; // Next HTB id available to use
447 int scheduler_fifo; // If the system has multiple CPUs, use FIFO scheduling policy for this process.
448 int lock_pages; // Lock pages into memory.
449 int icmp_rate; // Max number of ICMP unreachable per second to send>
450
451 u32 cluster_address; // Multicast address of cluster.
452 // Send to this address to have everyone hear.
453 char cluster_interface[64]; // Which interface to listen for multicast on.
454 int cluster_iam_master; // Are we the cluster master???
455 int cluster_iam_uptodate; // Set if we've got a full set of state from the master.
456 u32 cluster_master_address; // The network address of the cluster master.
457 // Zero if i am the cluster master.
458 int cluster_seq_number; // Sequence number of the next heartbeat we'll send out
459 // (or the seq number we're next expecting if we're a slave).
460 int cluster_undefined_sessions; // How many sessions we're yet to receive from the master.
461 int cluster_undefined_tunnels; // How many tunnels we're yet to receive from the master.
462 int cluster_highest_sessionid;
463 int cluster_highest_tunnelid;
464 clockt cluster_last_hb; // Last time we saw a heartbeat from the master.
465 int cluster_num_changes; // Number of changes queued.
466
467 int cluster_hb_interval; // How often to send a heartbeat.
468 int cluster_hb_timeout; // How many missed heartbeats trigger an election.
469
470 #ifdef BGP
471 #define BGP_NUM_PEERS 2
472 u16 as_number;
473 struct {
474 char name[64];
475 u16 as;
476 int keepalive;
477 int hold;
478 } neighbour[BGP_NUM_PEERS];
479 #endif
480 } configt;
481
482 enum config_typet { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP, MAC };
483 typedef struct
484 {
485 char *key;
486 int offset;
487 int size;
488 enum config_typet type;
489 } config_descriptt;
490
491 typedef struct
492 {
493 u8 op; // operation
494 #define FILTER_PORT_OP_NONE 0 // all ports match
495 #define FILTER_PORT_OP_EQ 1
496 #define FILTER_PORT_OP_NEQ 2
497 #define FILTER_PORT_OP_GT 3
498 #define FILTER_PORT_OP_LT 4
499 #define FILTER_PORT_OP_RANGE 5
500 portt port; // port (host byte order)
501 portt port2; // range
502 } ip_filter_portt;
503
504 typedef struct
505 {
506 int action; // permit/deny
507 #define FILTER_ACTION_DENY 1
508 #define FILTER_ACTION_PERMIT 2
509 u8 proto; // protocol: IPPROTO_* (netinet/in.h)
510 ipt src_ip; // source ip (network byte order)
511 ipt src_wild;
512 ip_filter_portt src_ports;
513 ipt dst_ip; // dest ip
514 ipt dst_wild;
515 ip_filter_portt dst_ports;
516 u8 tcp_flag_op; // match type: any, all
517 #define FILTER_FLAG_OP_ANY 1
518 #define FILTER_FLAG_OP_ALL 2
519 u8 tcp_sflags; // flags set
520 u8 tcp_cflags; // flags clear
521 } ip_filter_rulet;
522
523 #define TCP_FLAG_FIN 0x01
524 #define TCP_FLAG_SYN 0x02
525 #define TCP_FLAG_RST 0x04
526 #define TCP_FLAG_PSH 0x08
527 #define TCP_FLAG_ACK 0x10
528 #define TCP_FLAG_URG 0x20
529
530 #define MAXFILTER 32
531 #define MAXFILTER_RULES 32
532 typedef struct
533 {
534 char name[32]; // ACL name
535 int extended; // type: 0 = standard, 1 = extended
536 ip_filter_rulet rules[MAXFILTER_RULES];
537 int used; // session ref count
538 } ip_filtert;
539
540 // arp.c
541 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
542
543
544 // ppp.c
545 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
546 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
547 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
548 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
549 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
550 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
551 void sendchap(tunnelidt t, sessionidt s);
552 u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
553 void initlcp(tunnelidt t, sessionidt s);
554 void send_ipin(sessionidt s, u8 * buf, int len);
555
556
557 // radius.c
558 void initrad(void);
559 void radiussend(u16 r, u8 state);
560 void processrad(u8 *buf, int len, char socket_index);
561 void radiusretry(u16 r);
562 u16 radiusnew(sessionidt s);
563 void radiusclear(u16 r, sessionidt s);
564
565
566 // l2tpns.c
567 clockt backoff(u8 try);
568 sessionidt sessionbyip(ipt ip);
569 sessionidt sessionbyuser(char *username);
570 void sessionshutdown(sessionidt s, char *reason);
571 void send_garp(ipt ip);
572 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
573 void sendipcp(tunnelidt t, sessionidt s);
574 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
575 void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port);
576 int ip_filter(u8 *buf, int len, u8 filter);
577 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc);
578 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc);
579 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc);
580
581 #undef LOG
582 #undef LOG_HEX
583 #define LOG(D, a, s, t, f, ...) ({ if (D <= config->debug) _log(D, a, s, t, f, ## __VA_ARGS__); })
584 #define LOG_HEX(D, t, d, s) ({ if (D <= config->debug) _log_hex(D, t, d, s); })
585
586 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 5, 6)));
587 void _log_hex(int level, const char *title, const char *data, int maxsize);
588
589 int sessionsetup(tunnelidt t, sessionidt s);
590 int run_plugins(int plugin_type, void *data);
591 void rebuild_address_pool(void);
592 void throttle_session(sessionidt s, int rate_in, int rate_out);
593 int load_session(sessionidt, sessiont *);
594 void become_master(void); // We're the master; kick off any required master initializations.
595
596
597 // cli.c
598 void init_cli(char *hostname);
599 void cli_do_file(FILE *fh);
600 void cli_do(int sockfd);
601 int cli_arg_help(struct cli_def *cli, int cr_ok, char *entry, ...);
602
603
604 // icmp.c
605 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
606
607
608 extern tunnelt *tunnel;
609 extern sessiont *session;
610 extern sessioncountt *sess_count;
611 extern ippoolt *ip_address_pool;
612 #define sessionfree (session[0].next)
613
614 #define log_backtrace(count, max) \
615 if (count++ < max) { \
616 void *array[20]; \
617 char **strings; \
618 int size, i; \
619 LOG(0, 0, 0, t, "Backtrace follows"); \
620 size = backtrace(array, 10); \
621 strings = backtrace_symbols(array, size); \
622 if (strings) for (i = 0; i < size; i++) \
623 { \
624 LOG(0, 0, 0, t, "%s\n", strings[i]); \
625 } \
626 free(strings); \
627 }
628
629
630 extern configt *config;
631 extern time_t basetime; // Time when this process started.
632 extern time_t time_now; // Seconds since EPOCH.
633 extern u32 last_id;
634 extern struct Tstats *_statistics;
635 extern ipt my_address;
636 extern int tun_write(u8 *data, int size);
637 extern int clifd;
638
639
640 #define TIME (config->current_time)
641
642 // macros for handling help in cli commands
643 #define CLI_HELP_REQUESTED (argc > 0 && argv[argc-1][strlen(argv[argc-1])-1] == '?')
644 #define CLI_HELP_NO_ARGS (argc > 1 || argv[0][1]) ? CLI_OK : cli_arg_help(cli, 1, NULL)
645
646 // CVS identifiers (for "show version file")
647 extern char const *cvs_id_arp;
648 extern char const *cvs_id_cli;
649 extern char const *cvs_id_cluster;
650 extern char const *cvs_id_constants;
651 extern char const *cvs_id_control;
652 extern char const *cvs_id_icmp;
653 extern char const *cvs_id_l2tpns;
654 extern char const *cvs_id_ll;
655 extern char const *cvs_id_md5;
656 extern char const *cvs_id_ppp;
657 extern char const *cvs_id_radius;
658 extern char const *cvs_id_tbf;
659 extern char const *cvs_id_util;
660
661 #endif /* __L2TPNS_H__ */