l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.35 2004-11-16 07:54:32 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 "2.0.8"
  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 };
 128
 129 #define CLI_SESS_KILL           0x01
 130 #define CLI_SESS_SNOOP          0x02
 131 #define CLI_SESS_NOSNOOP        0x04
 132 #define CLI_SESS_THROTTLE       0x08
 133 #define CLI_SESS_NOTHROTTLE     0x10
 134
 135 struct cli_tunnel_actions {
 136         char action;
 137 };
 138
 139 #define CLI_TUN_KILL            0x01
 140
 141 // dump header: update number if internal format changes
 142 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
 143
 144 // structures
 145 typedef struct routes           // route
 146 {
 147         ipt ip;
 148         ipt mask;
 149 }
 150 routet;
 151
 152 typedef struct controls         // control message
 153 {
 154         struct controls *next;  // next in queue
 155         u16 length;             // length
 156         u8 buf[MAXCONTROL];
 157 }
 158 controlt;
 159
 160 typedef struct sessions
 161 {
 162         sessionidt next;                // next session in linked list
 163         sessionidt far;                 // far end session ID
 164         tunnelidt tunnel;               // near end tunnel ID
 165         ipt ip;                         // IP of session set by RADIUS response (host byte order).
 166         int ip_pool_index;              // index to IP pool
 167         unsigned long unique_id;        // unique session id
 168         u16 nr;                         // next receive
 169         u16 ns;                         // next send
 170         u32 magic;                      // ppp magic number
 171         u32 cin, cout;                  // byte counts
 172         u32 pin, pout;                  // packet counts
 173         u32 total_cin;                  // This counter is never reset while a session is open
 174         u32 total_cout;                 // This counter is never reset while a session is open
 175         u32 id;                         // session id
 176         u16 throttle_in;                // upstream throttle rate (kbps)
 177         u16 throttle_out;               // downstream throttle rate
 178         clockt opened;                  // when started
 179         clockt die;                     // being closed, when to finally free
 180         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 181         ipt dns1, dns2;                 // DNS servers
 182         routet route[MAXROUTE];         // static routes
 183         u16 radius;                     // which radius session is being used (0 for not waiting on authentication)
 184         u16 mru;                        // maximum receive unit
 185         u16 tbf_in;                     // filter bucket for throttling in from the user.
 186         u16 tbf_out;                    // filter bucket for throttling out to the user.
 187         u8 l2tp_flags;                  // various bit flags from the ICCN on the l2tp tunnel.
 188         u8 reserved_old_snoop;          // No longer used - remove at some time
 189         u8 walled_garden;               // is this session gardened?
 190         u8 flags1;                      // additional flags (currently unused);
 191         char random_vector[MAXTEL];
 192         int random_vector_length;
 193         char user[129];                 // user (needed in seesion for radius stop messages) (can we reduce this? --mo)
 194         char called[MAXTEL];            // called number
 195         char calling[MAXTEL];           // calling number
 196         u32 tx_connect_speed;
 197         u32 rx_connect_speed;
 198         u32 flags;                      // Various session flags.
 199         ipt snoop_ip;                   // Interception destination IP
 200         u16 snoop_port;                 // Interception destination port
 201         u16 sid;                        // near end session id.
 202         char reserved[20];              // Space to expand structure without changing HB_VERSION
 203 }
 204 sessiont;
 205
 206 #define SF_IPCP_ACKED   1       // Has this session seen an IPCP Ack?
 207 #define SF_LCP_ACKED    2       // LCP negotiated
 208
 209 typedef struct {
 210         u32     cin;
 211         u32     cout;
 212 } sessioncountt;
 213
 214 #define SESSIONPFC      1       // PFC negotiated flags
 215 #define SESSIONACFC     2       // ACFC negotiated flags
 216
 217 // 168 bytes per tunnel
 218 typedef struct tunnels
 219 {
 220         tunnelidt far;          // far end tunnel ID
 221         ipt ip;                 // Ip for far end
 222         portt port;             // port for far end
 223         u16 window;             // Rx window
 224         u16 nr;                 // next receive
 225         u16 ns;                 // next send
 226         int state;              // current state (tunnelstate enum)
 227         clockt last;            // when last control message sent (used for resend timeout)
 228         clockt retry;           // when to try resenting pending control
 229         clockt die;             // being closed, when to finally free
 230         clockt lastrec;         // when the last control message was received
 231         char hostname[128];     // tunnel hostname
 232         char vendor[128];       // LAC vendor
 233         u8 try;                 // number of retrys on a control message
 234         u16 controlc;           // outstaind messages in queue
 235         controlt *controls;     // oldest message
 236         controlt *controle;     // newest message
 237 }
 238 tunnelt;
 239
 240 // 180 bytes per radius session
 241 typedef struct radiuss          // outstanding RADIUS requests
 242 {
 243         sessionidt session;     // which session this applies to
 244         hasht auth;             // request authenticator
 245         clockt retry;           // when to try next
 246         char calling[MAXTEL];   // calling number
 247         char pass[129];         // password
 248         u8 id;                  // ID for PPP response
 249         u8 try;                 // which try we are on
 250         u8 state;               // state of radius requests
 251         u8 chap;                // set if CHAP used (is CHAP identifier)
 252 }
 253 radiust;
 254
 255 typedef struct
 256 {
 257         ipt             address;        // Host byte order..
 258         char            assigned;       // 1 if assigned, 0 if free
 259         sessionidt      session;
 260         clockt          last;           // last used
 261         char            user[129];      // user (try to have ip addresses persistent)
 262 }
 263 ippoolt;
 264
 265 #ifdef RINGBUFFER
 266 struct Tringbuffer
 267 {
 268         struct {
 269                 char level;
 270                 sessionidt session;
 271                 tunnelidt tunnel;
 272                 ipt address;
 273                 char message[MAX_LOG_LENGTH];
 274         } buffer[RINGBUFFER_SIZE];
 275         int head;
 276         int tail;
 277 };
 278 #endif
 279
 280 /*
 281  * Possible tunnel states
 282  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 283  */
 284 enum
 285 {
 286         TUNNELFREE,             // Not in use
 287         TUNNELOPEN,             // Active tunnel
 288         TUNNELDIE,              // Currently closing
 289         TUNNELOPENING,          // Busy opening
 290         TUNNELUNDEF,            // Undefined
 291 };
 292
 293 enum
 294 {
 295         RADIUSNULL,             // Not in use
 296         RADIUSCHAP,             // sending CHAP down PPP
 297         RADIUSAUTH,             // sending auth to RADIUS server
 298         RADIUSIPCP,             // sending IPCP to end user
 299         RADIUSSTART,            // sending start accounting to RADIUS server
 300         RADIUSSTOP,             // sending stop accounting to RADIUS server
 301         RADIUSWAIT,             // waiting timeout before available, in case delayed replies
 302         RADIUSDEAD,             // errored while talking to radius server.
 303 };
 304
 305 struct Tstats
 306 {
 307     time_t              start_time;
 308     time_t              last_reset;
 309
 310     unsigned long       tun_rx_packets;
 311     unsigned long       tun_tx_packets;
 312     unsigned long       tun_rx_bytes;
 313     unsigned long       tun_tx_bytes;
 314     unsigned long       tun_rx_errors;
 315     unsigned long       tun_tx_errors;
 316
 317     unsigned long       tunnel_rx_packets;
 318     unsigned long       tunnel_tx_packets;
 319     unsigned long       tunnel_rx_bytes;
 320     unsigned long       tunnel_tx_bytes;
 321     unsigned long       tunnel_rx_errors;
 322     unsigned long       tunnel_tx_errors;
 323
 324     unsigned long       tunnel_retries;
 325     unsigned long       radius_retries;
 326
 327     unsigned long       arp_sent;
 328
 329     unsigned long       packets_snooped;
 330
 331     unsigned long       tunnel_created;
 332     unsigned long       session_created;
 333     unsigned long       tunnel_timeout;
 334     unsigned long       session_timeout;
 335     unsigned long       radius_timeout;
 336     unsigned long       radius_overflow;
 337     unsigned long       tunnel_overflow;
 338     unsigned long       session_overflow;
 339
 340     unsigned long       ip_allocated;
 341     unsigned long       ip_freed;
 342
 343     unsigned long       c_forwarded;
 344     unsigned long       recv_forward;
 345 #ifdef STATISTICS
 346     unsigned long       call_processtun;
 347     unsigned long       call_processipout;
 348     unsigned long       call_processudp;
 349     unsigned long       call_sessionbyip;
 350     unsigned long       call_sessionbyuser;
 351     unsigned long       call_sendarp;
 352     unsigned long       call_sendipcp;
 353     unsigned long       call_tunnelsend;
 354     unsigned long       call_sessionkill;
 355     unsigned long       call_sessionshutdown;
 356     unsigned long       call_tunnelkill;
 357     unsigned long       call_tunnelshutdown;
 358     unsigned long       call_assign_ip_address;
 359     unsigned long       call_free_ip_address;
 360     unsigned long       call_dump_acct_info;
 361     unsigned long       call_sessionsetup;
 362     unsigned long       call_processpap;
 363     unsigned long       call_processchap;
 364     unsigned long       call_processlcp;
 365     unsigned long       call_processipcp;
 366     unsigned long       call_processipin;
 367     unsigned long       call_processccp;
 368     unsigned long       call_sendchap;
 369     unsigned long       call_processrad;
 370     unsigned long       call_radiussend;
 371     unsigned long       call_radiusretry;
 372 #endif
 373 };
 374
 375 #ifdef STATISTICS
 376
 377 #ifdef STAT_CALLS
 378 #define CSTAT(x)        STAT(x)
 379 #else
 380 #define CSTAT(x)
 381 #endif
 382
 383 #define STAT(x)         (_statistics->x++)
 384 #define INC_STAT(x,y)   (_statistics->x += (y))
 385 #define GET_STAT(x)     (_statistics->x)
 386 #define SET_STAT(x, y)  (_statistics->x = (y))
 387 #else
 388 #define CSTAT(x)
 389 #define STAT(x)
 390 #define INC_STAT(x,y)
 391 #define GET_STAT(x)     0
 392 #define SET_STAT(x, y)
 393 #endif
 394
 395 struct configt
 396 {
 397         int             debug;                          // debugging level
 398         time_t          start_time;                     // time when l2tpns was started
 399         char            bandwidth[256];                 // current bandwidth
 400         char            pid_file[256];                  // file to write PID to on startup
 401         int             wrote_pid;
 402         clockt          current_time;                   // 1/10ths of a second since the process started.
 403                                                         // means that we can only run a given process
 404                                                         // for 13 years without re-starting!
 405
 406         char            config_file[128];
 407         int             reload_config;                  // flag to re-read config (set by cli)
 408         int             cleanup_interval;               // interval between regular cleanups (in seconds)
 409         int             multi_read_count;               // amount of packets to read per fd in processing loop
 410
 411         char            tundevice[10];                  // tun device name
 412         char            log_filename[128];
 413         char            l2tpsecret[64];
 414
 415         char            radiussecret[64];
 416         int             radius_accounting;
 417         ipt             radiusserver[MAXRADSERVER];     // radius servers
 418         u16             radiusport[MAXRADSERVER];       // radius base ports
 419         u8              numradiusservers;               // radius server count
 420         short           num_radfds;                     // Number of radius filehandles allocated
 421
 422         ipt             default_dns1, default_dns2;
 423
 424         unsigned long   rl_rate;                        // default throttle rate
 425         int             num_tbfs;                       // number of throttle buckets
 426
 427         int             save_state;
 428         char            accounting_dir[128];
 429         ipt             bind_address;
 430         ipt             peer_address;
 431         int             send_garp;                      // Set to true to garp for vip address on startup
 432
 433         int             target_uid;
 434         int             dump_speed;
 435         char            plugins[64][MAXPLUGINS];
 436         char            old_plugins[64][MAXPLUGINS];
 437
 438         int             next_tbf;                       // Next HTB id available to use
 439         int             scheduler_fifo;                 // If the system has multiple CPUs, use FIFO scheduling policy for this process.
 440         int             lock_pages;                     // Lock pages into memory.
 441         int             icmp_rate;                      // Max number of ICMP unreachable per second to send>
 442
 443         u32             cluster_address;                // Multicast address of cluster.
 444                                                         // Send to this address to have everyone hear.
 445         char            cluster_interface[64];          // Which interface to listen for multicast on.
 446         int             cluster_iam_master;             // Are we the cluster master???
 447         int             cluster_iam_uptodate;           // Set if we've got a full set of state from the master.
 448         u32             cluster_master_address;         // The network address of the cluster master.
 449                                                         // Zero if i am the cluster master.
 450         int             cluster_seq_number;             // Sequence number of the next heartbeat we'll send out
 451                                                         // (or the seq number we're next expecting if we're a slave).
 452         int             cluster_undefined_sessions;     // How many sessions we're yet to receive from the master.
 453         int             cluster_undefined_tunnels;      // How many tunnels we're yet to receive from the master.
 454         int             cluster_highest_sessionid;
 455         int             cluster_highest_tunnelid;
 456         clockt          cluster_last_hb;                // Last time we saw a heartbeat from the master.
 457         int             cluster_num_changes;            // Number of changes queued.
 458
 459         int             cluster_hb_interval;            // How often to send a heartbeat.
 460         int             cluster_hb_timeout;             // How many missed heartbeats trigger an election.
 461
 462 #ifdef BGP
 463 #define BGP_NUM_PEERS   2
 464         u16             as_number;
 465         struct {
 466                 char    name[64];
 467                 u16     as;
 468                 int     keepalive;
 469                 int     hold;
 470         }               neighbour[BGP_NUM_PEERS];
 471 #endif
 472 };
 473
 474 enum config_typet { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP, MAC };
 475 struct config_descriptt
 476 {
 477         char *key;
 478         int offset;
 479         int size;
 480         enum config_typet type;
 481 };
 482
 483 // arp.c
 484 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
 485
 486
 487 // ppp.c
 488 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 489 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 490 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 491 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 492 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
 493 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 494 void sendchap(tunnelidt t, sessionidt s);
 495 u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
 496 void initlcp(tunnelidt t, sessionidt s);
 497 void send_ipin(sessionidt s, u8 * buf, int len);
 498
 499
 500 // radius.c
 501 void initrad(void);
 502 void radiussend(u16 r, u8 state);
 503 void processrad(u8 *buf, int len, char socket_index);
 504 void radiusretry(u16 r);
 505 u16 radiusnew(sessionidt s);
 506 void radiusclear(u16 r, sessionidt s);
 507
 508
 509 // l2tpns.c
 510 clockt backoff(u8 try);
 511 sessionidt sessionbyip(ipt ip);
 512 sessionidt sessionbyuser(char *username);
 513 void sessionshutdown(sessionidt s, char *reason);
 514 void send_garp(ipt ip);
 515 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
 516 void sendipcp(tunnelidt t, sessionidt s);
 517 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
 518 void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port);
 519 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc);
 520 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc);
 521 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc);
 522
 523 #undef LOG
 524 #undef LOG_HEX
 525 #define LOG(D, a, s, t, f, ...) ({ if (D <= config->debug) _log(D, a, s, t, f, ## __VA_ARGS__); })
 526 #define LOG_HEX(D, t, d, s)     ({ if (D <= config->debug) _log_hex(D, t, d, s); })
 527
 528 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 5, 6)));
 529 void _log_hex(int level, const char *title, const char *data, int maxsize);
 530
 531 int sessionsetup(tunnelidt t, sessionidt s);
 532 int run_plugins(int plugin_type, void *data);
 533 void rebuild_address_pool(void);
 534 void throttle_session(sessionidt s, int rate_in, int rate_out);
 535 int load_session(sessionidt, sessiont *);
 536 void become_master(void);       // We're the master; kick off any required master initializations.
 537
 538
 539 // cli.c
 540 void init_cli(char *hostname);
 541 void cli_do_file(FILE *fh);
 542 void cli_do(int sockfd);
 543 int cli_arg_help(struct cli_def *cli, int cr_ok, char *entry, ...);
 544
 545
 546 // icmp.c
 547 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
 548
 549
 550 extern tunnelt *tunnel;
 551 extern sessiont *session;
 552 extern sessioncountt *sess_count;
 553 extern ippoolt *ip_address_pool;
 554 #define sessionfree (session[0].next)
 555
 556 #define log_backtrace(count, max) \
 557 if (count++ < max) { \
 558         void *array[20]; \
 559         char **strings; \
 560         int size, i; \
 561         LOG(0, 0, 0, t, "Backtrace follows"); \
 562         size = backtrace(array, 10); \
 563         strings = backtrace_symbols(array, size); \
 564         if (strings) for (i = 0; i < size; i++) \
 565         { \
 566                 LOG(0, 0, 0, t, "%s\n", strings[i]); \
 567         } \
 568         free(strings); \
 569 }
 570
 571
 572 extern struct configt *config;
 573 extern time_t basetime;         // Time when this process started.
 574 extern time_t time_now;         // Seconds since EPOCH.
 575 extern u32 last_id;
 576 extern struct Tstats *_statistics;
 577 extern ipt my_address;
 578 extern int tun_write(u8 *data, int size);
 579 extern int clifd;
 580
 581
 582 #define TIME (config->current_time)
 583
 584 // macros for handling help in cli commands
 585 #define CLI_HELP_REQUESTED      (argc > 0 && argv[argc-1][strlen(argv[argc-1])-1] == '?')
 586 #define CLI_HELP_NO_ARGS        (argc > 1 || argv[0][1]) ? CLI_OK : cli_arg_help(cli, 1, NULL)
 587
 588 // CVS identifiers (for "show version file")
 589 extern char const *cvs_id_arp;
 590 extern char const *cvs_id_cli;
 591 extern char const *cvs_id_cluster;
 592 extern char const *cvs_id_constants;
 593 extern char const *cvs_id_control;
 594 extern char const *cvs_id_icmp;
 595 extern char const *cvs_id_l2tpns;
 596 extern char const *cvs_id_ll;
 597 extern char const *cvs_id_md5;
 598 extern char const *cvs_id_ppp;
 599 extern char const *cvs_id_radius;
 600 extern char const *cvs_id_tbf;
 601 extern char const *cvs_id_util;
 602
 603 #endif /* __L2TPNS_H__ */