l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.16 2004/08/26 04:44:26 fred_nerk 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 "2.0.1"
  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       ((2 << (RADIUS_SHIFT - 1)) * 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_TIMEOUT       3000    // 5 minutes in 1/10th seconds to wait for radius to cleanup on shutdown
  44
  45 // Constants
  46 #include "config.h"
  47 #ifndef PLUGINDIR
  48 #define PLUGINDIR       LIBDIR                  // Plugins
  49 #endif
  50
  51 #ifndef PLUGINCONF
  52 #define PLUGINCONF      ETCDIR                  // Plugin config dir
  53 #endif
  54
  55 #ifndef DATADIR
  56 #define DATADIR         "/tmp"
  57 #endif
  58
  59 #ifndef FLASHDIR
  60 #define FLASHDIR        ETCDIR
  61 #endif
  62
  63 #define TUNDEVICE       "/dev/net/tun"
  64 #define STATEFILE       DATADIR "/state.dump"           // State dump file
  65 #define CONFIGFILE      FLASHDIR "/startup-config"      // Configuration file
  66 #define CLIUSERS        FLASHDIR "/users"               // CLI Users file
  67 #define IPPOOLFILE      FLASHDIR "/ip_pool"             // Address pool configuration
  68 #define ACCT_TIME       3000            // 5 minute accounting interval
  69 #define L2TPPORT        1701            // L2TP port
  70 #define RADPORT         1645            // old radius port...
  71 #define PKTARP          0x0806          // ARP packet type
  72 #define PKTIP           0x0800          // IP packet type
  73 #define PSEUDOMAC       0x0200          // pseudo MAC prefix (local significant MAC)
  74 #define PPPPAP          0xC023
  75 #define PPPCHAP         0xC223
  76 #define PPPLCP          0xC021
  77 #define PPPIPCP         0x8021
  78 #define PPPCCP          0x80FD
  79 #define PPPIP           0x0021
  80 #define PPPMP           0x003D
  81 #define MIN_IP_SIZE     0x19
  82 enum
  83 {
  84         ConfigReq = 1,
  85         ConfigAck,
  86         ConfigNak,
  87         ConfigRej,
  88         TerminateReq,
  89         TerminateAck,
  90         CodeRej,
  91         ProtocolRej,
  92         EchoReq,
  93         EchoReply,
  94         DiscardRequest,
  95         IdentRequest
  96 };
  97
  98 // Types
  99 typedef unsigned short u16;
 100 typedef unsigned int u32;
 101 typedef unsigned char u8;
 102 typedef u32 ipt;
 103 typedef u16 portt;
 104 typedef u16 sessionidt;
 105 typedef u16 tunnelidt;
 106 typedef u32 clockt;
 107 typedef u8 hasht[16];
 108
 109 // CLI actions
 110 struct cli_session_actions {
 111         char action;
 112         ipt snoop_ip;
 113         u16 snoop_port;
 114         int throttle;
 115 };
 116
 117 #define CLI_SESS_KILL           0x01
 118 #define CLI_SESS_SNOOP          0x02
 119 #define CLI_SESS_NOSNOOP        0x04
 120 #define CLI_SESS_THROTTLE       0x08
 121 #define CLI_SESS_NOTHROTTLE     0x10
 122
 123 struct cli_tunnel_actions {
 124         char action;
 125 };
 126
 127 #define CLI_TUN_KILL            0x01
 128
 129 // dump header: update number if internal format changes
 130 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
 131
 132 // structures
 133 typedef struct routes           // route
 134 {
 135         ipt ip;
 136         ipt mask;
 137 }
 138 routet;
 139
 140 typedef struct controls         // control message
 141 {
 142         struct controls *next;  // next in queue
 143         u16 length;             // length
 144         u8 buf[MAXCONTROL];
 145 }
 146 controlt;
 147
 148 typedef struct sessions
 149 {
 150         sessionidt next;                // next session in linked list
 151         sessionidt far;                 // far end session ID
 152         tunnelidt tunnel;               // tunnel ID
 153         ipt ip;                         // IP of session set by RADIUS response (host byte order).
 154         int ip_pool_index;              // index to IP pool
 155         unsigned long sid;              // session id for hsddb
 156         u16 nr;                         // next receive
 157         u16 ns;                         // next send
 158         u32 magic;                      // ppp magic number
 159         u32 cin, cout;                  // byte counts
 160         u32 pin, pout;                  // packet counts
 161         u32 total_cin;                  // This counter is never reset while a session is open
 162         u32 total_cout;                 // This counter is never reset while a session is open
 163         u32 id;                         // session id
 164         u32 throttle;                   // non-zero if this session is throttled.
 165         clockt opened;                  // when started
 166         clockt die;                     // being closed, when to finally free
 167         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 168         ipt dns1, dns2;                 // DNS servers
 169         routet route[MAXROUTE];         // static routes
 170         u16 radius;                     // which radius session is being used (0 for not waiting on authentication)
 171         u16 mru;                        // maximum receive unit
 172         u16 tbf_in;                     // filter bucket for throttling in from the user.
 173         u16 tbf_out;                    // filter bucket for throttling out to the user.
 174         u8 l2tp_flags;                  // various bit flags from the ICCN on the l2tp tunnel.
 175         u8 walled_garden;               // is this session gardened?
 176         u8 flags1;                      // additional flags (currently unused);
 177         char random_vector[MAXTEL];
 178         int random_vector_length;
 179         char user[129];                 // user (needed in seesion for radius stop messages) (can we reduce this? --mo)
 180         char called[MAXTEL];            // called number
 181         char calling[MAXTEL];           // calling number
 182         u32 tx_connect_speed;
 183         u32 rx_connect_speed;
 184         u32 flags;                      // Various session flags.
 185         ipt snoop_ip;                   // Interception destination IP
 186         u16 snoop_port;                 // Interception destination port
 187         char reserved[28];              // Space to expand structure without changing HB_VERSION
 188 }
 189 sessiont;
 190
 191 #define SF_IPCP_ACKED   (1<<0)          // Has this session seen an IPCP Ack?
 192
 193 typedef struct {
 194         u32     cin;
 195         u32     cout;
 196 } sessioncountt;
 197
 198 #define SESSIONPFC      1            // PFC negotiated flags
 199 #define SESSIONACFC     2           // ACFC negotiated flags
 200 #define SESSIONLCPACK   4       // LCP negotiated
 201
 202 // 168 bytes per tunnel
 203 typedef struct tunnels
 204 {
 205         tunnelidt far;          // far end tunnel ID
 206         ipt ip;                 // Ip for far end
 207         portt port;             // port for far end
 208         u16 window;             // Rx window
 209         u16 nr;                 // next receive
 210         u16 ns;                 // next send
 211         int state;              // current state (tunnelstate enum)
 212         clockt last;            // when last control message sent (used for resend timeout)
 213         clockt retry;           // when to try resenting pending control
 214         clockt die;             // being closed, when to finally free
 215         clockt lastrec;         // when the last control message was received
 216         char hostname[128];     // tunnel hostname
 217         char vendor[128];       // LAC vendor
 218         u8 try;                 // number of retrys on a control message
 219         u16 controlc;           // outstaind messages in queue
 220         controlt *controls;     // oldest message
 221         controlt *controle;     // newest message
 222 }
 223 tunnelt;
 224
 225 // 180 bytes per radius session
 226 typedef struct radiuss          // outstanding RADIUS requests
 227 {
 228         sessionidt session;     // which session this applies to
 229         hasht auth;             // request authenticator
 230         clockt retry;           // when to try next
 231         char calling[MAXTEL];   // calling number
 232         char pass[129];         // password
 233         u8 id;                  // ID for PPP response
 234         u8 try;                 // which try we are on
 235         u8 state;               // state of radius requests
 236         u8 chap;                // set if CHAP used (is CHAP identifier)
 237 }
 238 radiust;
 239
 240 typedef struct
 241 {
 242         ipt             address;        // Host byte order..
 243         char            assigned;       // 1 if assigned, 0 if free
 244         sessionidt      session;
 245         clockt          last;           // last used
 246         char            user[129];      // user (try to have ip addresses persistent)
 247 }
 248 ippoolt;
 249
 250 #ifdef RINGBUFFER
 251 struct Tringbuffer
 252 {
 253         struct {
 254                 char level;
 255                 sessionidt session;
 256                 tunnelidt tunnel;
 257                 ipt address;
 258                 char message[MAX_LOG_LENGTH];
 259         } buffer[RINGBUFFER_SIZE];
 260         int head;
 261         int tail;
 262 };
 263 #endif
 264
 265 /*
 266  * Possible tunnel states
 267  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 268  */
 269 enum
 270 {
 271         TUNNELFREE,             // Not in use
 272         TUNNELOPEN,             // Active tunnel
 273         TUNNELDIE,              // Currently closing
 274         TUNNELOPENING,          // Busy opening
 275         TUNNELUNDEF,            // Undefined
 276 };
 277
 278 enum
 279 {
 280         RADIUSNULL,             // Not in use
 281         RADIUSCHAP,             // sending CHAP down PPP
 282         RADIUSAUTH,             // sending auth to RADIUS server
 283         RADIUSIPCP,             // sending IPCP to end user
 284         RADIUSSTART,            // sending start accounting to RADIUS server
 285         RADIUSSTOP,             // sending stop accounting to RADIUS server
 286         RADIUSWAIT,             // waiting timeout before available, in case delayed replies
 287         RADIUSDEAD,             // errored while talking to radius server.
 288 };
 289
 290 struct Tstats
 291 {
 292     time_t              start_time;
 293     time_t              last_reset;
 294
 295     unsigned long       tun_rx_packets;
 296     unsigned long       tun_tx_packets;
 297     unsigned long       tun_rx_bytes;
 298     unsigned long       tun_tx_bytes;
 299     unsigned long       tun_rx_errors;
 300     unsigned long       tun_tx_errors;
 301
 302     unsigned long       tunnel_rx_packets;
 303     unsigned long       tunnel_tx_packets;
 304     unsigned long       tunnel_rx_bytes;
 305     unsigned long       tunnel_tx_bytes;
 306     unsigned long       tunnel_rx_errors;
 307     unsigned long       tunnel_tx_errors;
 308
 309     unsigned long       tunnel_retries;
 310     unsigned long       radius_retries;
 311
 312     unsigned long       arp_sent;
 313
 314     unsigned long       packets_snooped;
 315
 316     unsigned long       tunnel_created;
 317     unsigned long       session_created;
 318     unsigned long       tunnel_timeout;
 319     unsigned long       session_timeout;
 320     unsigned long       radius_timeout;
 321     unsigned long       radius_overflow;
 322     unsigned long       tunnel_overflow;
 323     unsigned long       session_overflow;
 324
 325     unsigned long       ip_allocated;
 326     unsigned long       ip_freed;
 327
 328     unsigned long       c_forwarded;
 329     unsigned long       recv_forward;
 330 #ifdef STATISTICS
 331     unsigned long       call_processtun;
 332     unsigned long       call_processipout;
 333     unsigned long       call_processudp;
 334     unsigned long       call_sessionbyip;
 335     unsigned long       call_sessionbyuser;
 336     unsigned long       call_sendarp;
 337     unsigned long       call_sendipcp;
 338     unsigned long       call_tunnelsend;
 339     unsigned long       call_sessionkill;
 340     unsigned long       call_sessionshutdown;
 341     unsigned long       call_tunnelkill;
 342     unsigned long       call_tunnelshutdown;
 343     unsigned long       call_assign_ip_address;
 344     unsigned long       call_free_ip_address;
 345     unsigned long       call_dump_acct_info;
 346     unsigned long       call_sessionsetup;
 347     unsigned long       call_processpap;
 348     unsigned long       call_processchap;
 349     unsigned long       call_processlcp;
 350     unsigned long       call_processipcp;
 351     unsigned long       call_processipin;
 352     unsigned long       call_processccp;
 353     unsigned long       call_sendchap;
 354     unsigned long       call_processrad;
 355     unsigned long       call_radiussend;
 356     unsigned long       call_radiusretry;
 357 #endif
 358 };
 359
 360 #ifdef STATISTICS
 361
 362 #ifdef STAT_CALLS
 363 #define CSTAT(x)        STAT(x)
 364 #else
 365 #define CSTAT(x)
 366 #endif
 367
 368 #define STAT(x)         (_statistics->x++)
 369 #define INC_STAT(x,y)   (_statistics->x += (y))
 370 #define GET_STAT(x)     (_statistics->x)
 371 #define SET_STAT(x, y)  (_statistics->x = (y))
 372 #else
 373 #define CSTAT(x)
 374 #define STAT(x)
 375 #define INC_STAT(x,y)
 376 #define GET_STAT(x)     0
 377 #define SET_STAT(x, y)
 378 #endif
 379
 380 struct configt
 381 {
 382         int             debug;                          // debugging level
 383         time_t          start_time;                     // time when l2tpns was started
 384         char            bandwidth[256];                 // current bandwidth
 385         char            pid_file[256];                  // file to write PID to on startup
 386         int             wrote_pid;
 387         clockt          current_time;                   // 1/10ths of a second since the process started.
 388                                                         // means that we can only run a given process
 389                                                         // for 13 years without re-starting!
 390
 391         char            config_file[128];
 392         int             reload_config;                  // flag to re-read config (set by cli)
 393         int             cleanup_interval;               // interval between regular cleanups (in seconds)
 394         int             multi_read_count;               // amount of packets to read per fd in processing loop
 395
 396         char            tundevice[10];                  // tun device name
 397         char            log_filename[128];
 398         char            l2tpsecret[64];
 399
 400         char            radiussecret[64];
 401         int             radius_accounting;
 402         ipt             radiusserver[MAXRADSERVER];     // radius servers
 403         u16             radiusport[MAXRADSERVER];       // radius base ports
 404         u8              numradiusservers;               // radius server count
 405         short           num_radfds;                     // Number of radius filehandles allocated
 406
 407         ipt             default_dns1, default_dns2;
 408
 409         unsigned long   rl_rate;
 410         int             save_state;
 411         char            accounting_dir[128];
 412         ipt             bind_address;
 413         int             send_garp;                      // Set to true to garp for vip address on startup
 414
 415         int             target_uid;
 416         int             dump_speed;
 417         char            plugins[64][MAXPLUGINS];
 418         char            old_plugins[64][MAXPLUGINS];
 419
 420         int             next_tbf;                       // Next HTB id available to use
 421         int             scheduler_fifo;                 // If the system has multiple CPUs, use FIFO scheduling policy for this process.
 422         int             lock_pages;                     // Lock pages into memory.
 423         int             icmp_rate;                      // Max number of ICMP unreachable per second to send>
 424
 425         u32             cluster_address;                // Multicast address of cluster.
 426                                                         // Send to this address to have everyone hear.
 427         char            cluster_interface[64];          // Which interface to listen for multicast on.
 428         int             cluster_iam_master;             // Are we the cluster master???
 429         int             cluster_iam_uptodate;           // Set if we've got a full set of state from the master.
 430         u32             cluster_master_address;         // The network address of the cluster master.
 431                                                         // Zero if i am the cluster master.
 432         int             cluster_seq_number;             // Sequence number of the next heartbeat we'll send out
 433                                                         // (or the seq number we're next expecting if we're a slave).
 434         int             cluster_undefined_sessions;     // How many sessions we're yet to receive from the master.
 435         int             cluster_undefined_tunnels;      // How many tunnels we're yet to receive from the master.
 436         int             cluster_highest_sessionid;
 437         int             cluster_highest_tunnelid;
 438         clockt          cluster_last_hb;                // Last time we saw a heartbeat from the master.
 439         int             cluster_num_changes;            // Number of changes queued.
 440
 441         int             cluster_hb_interval;            // How often to send a heartbeat.
 442         int             cluster_hb_timeout;             // How many missed heartbeats trigger an election.
 443
 444 #ifdef BGP
 445         u16             as_number;
 446         char            bgp_peer[2][64];
 447         u16             bgp_peer_as[2];
 448 #endif
 449 };
 450
 451 struct config_descriptt
 452 {
 453         char *key;
 454         int offset;
 455         int size;
 456         enum { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP } type;
 457 };
 458
 459 // arp.c
 460 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
 461
 462
 463 // ppp.c
 464 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 465 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 466 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 467 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 468 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
 469 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 470 void sendchap(tunnelidt t, sessionidt s);
 471 u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
 472 u8 *findppp(u8 * b, u8 mtype);
 473 void initlcp(tunnelidt t, sessionidt s);
 474 void dumplcp(u8 *p, int l);
 475
 476
 477 // radius.c
 478 void initrad(void);
 479 void radiussend(u16 r, u8 state);
 480 void processrad(u8 *buf, int len, char socket_index);
 481 void radiusretry(u16 r);
 482 u16 radiusnew(sessionidt s);
 483 void radiusclear(u16 r, sessionidt s);
 484
 485 // throttle.c
 486 int throttle_session(sessionidt s, int throttle);
 487
 488
 489 // rl.c
 490 void init_rl();
 491 u16 rl_create_tbf();
 492 u16 rl_get_tbf();
 493 void rl_done_tbf(u16 t);
 494 void rl_destroy_tbf(u16 t);
 495
 496
 497 // l2tpns.c
 498 clockt now(void);
 499 clockt backoff(u8 try);
 500 void routeset(sessionidt, ipt ip, ipt mask, ipt gw, u8 add);
 501 void inittun(void);
 502 void initudp(void);
 503 void initdata(void);
 504 void initippool();
 505 sessionidt sessionbyip(ipt ip);
 506 sessionidt sessionbyuser(char *username);
 507 void sessionshutdown(sessionidt s, char *reason);
 508 void sessionsendarp(sessionidt s);
 509 void send_garp(ipt ip);
 510 void sessionkill(sessionidt s, char *reason);
 511 void control16(controlt * c, u16 avp, u16 val, u8 m);
 512 void control32(controlt * c, u16 avp, u32 val, u8 m);
 513 void controls(controlt * c, u16 avp, char *val, u8 m);
 514 void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m);
 515 controlt *controlnew(u16 mtype);
 516 void controlnull(tunnelidt t);
 517 void controladd(controlt * c, tunnelidt t, sessionidt s);
 518 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
 519 void tunnelkill(tunnelidt t, char *reason);
 520 void tunnelshutdown(tunnelidt t, char *reason);
 521 void sendipcp(tunnelidt t, sessionidt s);
 522 void processipout(u8 * buf, int len);
 523 void processarp(u8 * buf, int len);
 524 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
 525 void processtun(u8 * buf, int len);
 526 void processcontrol(u8 * buf, int len, struct sockaddr_in *addr);
 527 int assign_ip_address(sessionidt s);
 528 void free_ip_address(sessionidt s);
 529 void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port);
 530 void dump_acct_info();
 531 void mainloop(void);
 532 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc);
 533 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc);
 534 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc);
 535
 536 #define log _log
 537 #ifndef log_hex
 538 #define log_hex(a,b,c,d) do{if (a <= config->debug) _log_hex(a,0,0,0,b,c,d);}while (0)
 539 #endif
 540 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 5, 6)));
 541 void _log_hex(int level, ipt address, sessionidt s, tunnelidt t, const char *title, const char *data, int maxsize);
 542 void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response);
 543 int sessionsetup(tunnelidt t, sessionidt s);
 544 int cluster_send_session(int s);
 545 int cluster_send_tunnel(int t);
 546 int cluster_send_goodbye();
 547 void init_cli(char *hostname);
 548 void cli_do_file(FILE *fh);
 549 void cli_do(int sockfd);
 550 int cli_arg_help(struct cli_def *cli, int cr_ok, char *entry, ...);
 551 #ifdef RINGBUFFER
 552 void ringbuffer_dump(FILE *stream);
 553 #endif
 554 void initplugins(void);
 555 int run_plugins(int plugin_type, void *data);
 556 void add_plugin(char *plugin_name);
 557 void remove_plugin(char *plugin_name);
 558 void plugins_done(void);
 559 void tunnelclear(tunnelidt t);
 560 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
 561 void fix_address_pool(int sid);
 562 void rebuild_address_pool(void);
 563 void send_ipin(sessionidt s, u8 * buf, int len);
 564 int throttle_session(sessionidt s, int throttle);
 565 int load_session(sessionidt, sessiont *);
 566 void become_master(void);       // We're the master; kick off any required master initializations.
 567 extern tunnelt *tunnel;
 568 extern sessiont *session;
 569 extern sessioncountt *sess_count;
 570 extern ippoolt *ip_address_pool;
 571 #define sessionfree (session[0].next)
 572
 573 #define log_backtrace(count, max) \
 574 if (count++ < max) { \
 575         void *array[20]; \
 576         char **strings; \
 577         int size, i; \
 578         log(0, 0, 0, t, "Backtrace follows"); \
 579         size = backtrace(array, 10); \
 580         strings = backtrace_symbols(array, size); \
 581         if (strings) for (i = 0; i < size; i++) \
 582         { \
 583                 log(0, 0, 0, t, "%s\n", strings[i]); \
 584         } \
 585         free(strings); \
 586 }
 587
 588
 589 extern struct configt *config;
 590 extern time_t basetime;         // Time when this process started.
 591 extern time_t time_now;         // Seconds since EPOCH.
 592 extern u32 last_sid;
 593 extern struct Tstats *_statistics;
 594 extern ipt my_address;
 595 extern int tun_write(u8 *data, int size);
 596
 597
 598 #define TIME (config->current_time)
 599
 600 // macros for handling help in cli commands
 601 #define CLI_HELP_REQUESTED      (argc > 0 && argv[argc-1][strlen(argv[argc-1])-1] == '?')
 602 #define CLI_HELP_NO_ARGS        (argc > 1 || argv[0][1]) ? CLI_OK : cli_arg_help(cli, 1, NULL)
 603
 604 // CVS identifiers (for "show version file")
 605 extern char const *cvs_id_arp;
 606 extern char const *cvs_id_cli;
 607 extern char const *cvs_id_cluster;
 608 extern char const *cvs_id_constants;
 609 extern char const *cvs_id_control;
 610 extern char const *cvs_id_icmp;
 611 extern char const *cvs_id_l2tpns;
 612 extern char const *cvs_id_ll;
 613 extern char const *cvs_id_md5;
 614 extern char const *cvs_id_ppp;
 615 extern char const *cvs_id_radius;
 616 extern char const *cvs_id_tbf;
 617 extern char const *cvs_id_util;
 618
 619 #endif /* __L2TPNS_H__ */