l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.121 2009-12-08 14:49:28 bodea Exp $
   3
   4 #ifndef __L2TPNS_H__
   5 #define __L2TPNS_H__
   6
   7 #include <netinet/in.h>
   8 #include <stdio.h>
   9 #include <signal.h>
  10 #include <stdlib.h>
  11 #include <netinet/in.h>
  12 #include <net/ethernet.h>
  13 #include <sys/socket.h>
  14 #include <arpa/inet.h>
  15 #include <sys/types.h>
  16 #include <libcli.h>
  17
  18 #define VERSION "2.2.1-2sames3.14"
  19
  20 // Limits
  21 #define MAXTUNNEL       500             // could be up to 65535
  22 #define MAXBUNDLE       300             // could be up to 65535
  23 #define MAXBUNDLESES    12              // Maximum number of member links in bundle
  24 #define MAXADDRESS      20              // Maximum length for the Endpoint Discrminiator address
  25 #define MAXSESSION      60000           // could be up to 65535
  26 #define MAXTBFS         6000            // Maximum token bucket filters. Might need up to 2 * session.
  27 #define MAXSESSINGRP    12              // Maximum number of member links in grouped session
  28 #define MAXGROUPE               300     // could be up to 65535, Maximum number of grouped session
  29 #define MAXROUTEINGRP   15              // max static routes per group
  30
  31 // Tunnel Id reserved for pppoe
  32 #define TUNNEL_ID_PPPOE 1
  33
  34 #define RADIUS_SHIFT    6
  35 #define RADIUS_FDS      (1 << RADIUS_SHIFT)
  36 #define RADIUS_MASK     ((1 << RADIUS_SHIFT) - 1)
  37 #define MAXRADIUS       (1 << (8 + RADIUS_SHIFT))
  38
  39 #define T_UNDEF         (0xffff)        // A tunnel ID that won't ever be used. Mark session as undefined.
  40 #define T_FREE          (0)             // A tunnel ID that won't ever be used. Mark session as free.
  41
  42 #define MAXCONTROL      1000            // max length control message we ever send...
  43 #define MINMTU          576             // minimum recommended MTU (rfc1063)
  44 #define MAXMTU          2600            // arbitrary maximum MTU
  45 #define PPPoE_MRU       1492            // maximum PPPoE MRU (rfc2516: 1500 less PPPoE header (6) and PPP protocol ID (2))
  46 #define MAXETHER        (MAXMTU+18)     // max packet we try sending to tun
  47 #define MAXTEL          96              // telephone number
  48 #define MAXHOSTNAME     256             // hostname
  49 #define MAXUSER         128             // username
  50 #define MAXPASS         128             // password
  51 #define MAXCLASS        128             // radius class attribute size
  52 #define MAXPLUGINS      20              // maximum number of plugins to load
  53 #define MAXRADSERVER    10              // max radius servers
  54 #define MAXROUTE        10              // max static routes per session
  55 #define MAXROUTE6       5               // max static Ipv6 routes per session
  56 #define MAXIPPOOL       131072          // max number of ip addresses in pool
  57 #define RINGBUFFER_SIZE 10000           // Number of ringbuffer entries to allocate
  58 #define MAX_LOG_LENGTH  512             // Maximum size of log message
  59 #define ECHO_TIMEOUT    10              // Time between last packet sent and LCP ECHO generation
  60 #define IDLE_ECHO_TIMEOUT       240             // Time between last packet seen and session shutdown
  61 #define BUSY_WAIT_TIME  3000            // 5 minutes in 1/10th seconds to wait for radius to cleanup on shutdown
  62
  63 #define MP_BEGIN        0x80            // This value is used when (b)egin bit is set in MP header
  64 #define MP_END          0x40            // This value is used when (e)nd bit is set in MP header
  65 #define MP_BOTH_BITS    0xC0            // This value is used when both bits (begin and end) are set in MP header
  66
  67 #define MINFRAGLEN      64              // Minumum fragment length
  68 #define MAXFRAGLEN      1496    // Maximum length for Multilink fragment (The multilink may contain only one link)
  69 #define MAXFRAGNUM      512             // Maximum number of Multilink fragment in a bundle (must be in the form of 2^X)
  70                                         // it's not expected to have a space for more than 10 unassembled packets = 10 * MAXBUNDLESES
  71 #define MAXFRAGNUM_MASK (MAXFRAGNUM - 1)                // Must be equal to MAXFRAGNUM-1
  72
  73 // Multi bind address constants
  74 #define MAX_UDPFD 4
  75 #define MAX_BINDADDR MAX_UDPFD
  76 // + 1 for the LAC Hostname
  77 #define MAX_NBHOSTNAME (MAX_UDPFD + 1)
  78 // 4 + 1 for the udplac
  79 #define INIT_TABUDPFD {-1, -1, -1, -1, -1}
  80 #define INIT_TABUDPVAR {0, 0, 0, 0, 0}
  81
  82 // Constants
  83 #ifndef ETCDIR
  84 #define ETCDIR          "/etc/l2tpns"
  85 #endif
  86
  87 #ifndef LIBDIR
  88 #define LIBDIR          "/usr/lib/l2tpns"
  89 #endif
  90
  91 #ifndef PLUGINDIR
  92 #define PLUGINDIR       LIBDIR          // Plugins
  93 #endif
  94
  95 #ifndef PLUGINCONF
  96 #define PLUGINCONF      ETCDIR          // Plugin config dir
  97 #endif
  98
  99 #ifndef FLASHDIR
 100 #define FLASHDIR        ETCDIR
 101 #endif
 102
 103 #define TUNDEVICE       "/dev/net/tun"
 104 #define RANDOMDEVICE    "/dev/urandom"                  // default, not as secure as /dev/random but non-blocking
 105 #define CONFIGFILE      FLASHDIR "/startup-config"      // Configuration file
 106 #define CLIUSERS        FLASHDIR "/users"               // CLI Users file
 107 #define IPPOOLFILE      FLASHDIR "/ip_pool"             // Address pool configuration
 108 #define ACCT_TIME       3000                            // 5 minute accounting interval
 109 #define ACCT_SHUT_TIME  600                             // 1 minute for counters of shutdown sessions
 110 #define L2TPPORT        1701                            // L2TP port
 111 #define RADPORT         1645                            // old radius port...
 112 #define DAEPORT         3799                            // DAE port
 113 #define PKTARP          0x0806                          // ARP packet type
 114 #define PKTIP           0x0800                          // IPv4 packet type
 115 #define PKTIPV6         0x86DD                          // IPv6 packet type
 116 #define PPPPAP          0xC023
 117 #define PPPCHAP         0xC223
 118 #define PPPLCP          0xC021
 119 #define PPPIPCP         0x8021
 120 #define PPPIPV6CP       0x8057
 121 #define PPPCCP          0x80FD
 122 #define PPPIP           0x0021
 123 #define PPPIPV6         0x0057
 124 #define PPPMP           0x003D
 125 #define MIN_IP_SIZE     0x19
 126
 127 enum {
 128         ConfigReq = 1,
 129         ConfigAck,
 130         ConfigNak,
 131         ConfigRej,
 132         TerminateReq,
 133         TerminateAck,
 134         CodeRej,
 135         ProtocolRej,
 136         EchoReq,
 137         EchoReply,
 138         DiscardRequest,
 139         IdentRequest
 140 };
 141
 142 enum {
 143         AccessRequest = 1,
 144         AccessAccept,
 145         AccessReject,
 146         AccountingRequest,
 147         AccountingResponse,
 148         AccessChallenge = 11,
 149         DisconnectRequest = 40,
 150         DisconnectACK,
 151         DisconnectNAK,
 152         CoARequest,
 153         CoAACK,
 154         CoANAK
 155 };
 156
 157 // PPP phases
 158 enum {
 159         Dead,
 160         Establish,
 161         Authenticate,
 162         Network,
 163         Terminate
 164 };
 165
 166 // PPP states
 167 enum {
 168         Initial,
 169         Starting,
 170         Closed,
 171         Stopped,
 172         Closing,
 173         Stopping,
 174         RequestSent,
 175         AckReceived,
 176         AckSent,
 177         Opened
 178 };
 179
 180 // reset state machine counters
 181 #define initialise_restart_count(_s, _fsm)                      \
 182         sess_local[_s]._fsm.conf_sent =                         \
 183         sess_local[_s]._fsm.nak_sent = 0
 184
 185 // no more attempts
 186 #define zero_restart_count(_s, _fsm) ({                         \
 187         sess_local[_s]._fsm.conf_sent =                         \
 188                 config->ppp_max_configure;                      \
 189         sess_local[_s]._fsm.restart =                           \
 190                 time_now + config->ppp_restart_time;            \
 191 })
 192
 193 // increment ConfReq counter and reset timer
 194 #define restart_timer(_s, _fsm) ({                              \
 195         sess_local[_s]._fsm.conf_sent++;                        \
 196         sess_local[_s]._fsm.restart =                           \
 197                 time_now + config->ppp_restart_time;            \
 198 })
 199
 200 // stop timer on change to state where timer does not run
 201 #define change_state(_s, _fsm, _new) ({                         \
 202         if (_new != session[_s].ppp._fsm)                       \
 203         {                                                       \
 204                 switch (_new)                                   \
 205                 {                                               \
 206                 case Initial:                                   \
 207                 case Starting:                                  \
 208                 case Closed:                                    \
 209                 case Stopped:                                   \
 210                 case Opened:                                    \
 211                         sess_local[_s]._fsm.restart = 0;        \
 212                         initialise_restart_count(_s, _fsm);     \
 213                 }                                               \
 214                 session[_s].ppp._fsm = _new;                    \
 215                 cluster_send_session(_s);                       \
 216         }                                                       \
 217 })
 218
 219 // Types
 220 typedef uint16_t sessionidt;
 221 typedef uint16_t bundleidt;
 222 typedef uint16_t tunnelidt;
 223 typedef uint16_t groupidt;
 224 typedef uint32_t clockt;
 225 typedef uint8_t hasht[16];
 226
 227 // CLI actions
 228 struct cli_session_actions {
 229         char action;
 230         in_addr_t snoop_ip;
 231         uint16_t snoop_port;
 232         int throttle_in;
 233         int throttle_out;
 234         int filter_in;
 235         int filter_out;
 236 };
 237
 238 #define CLI_SESS_KILL           0x01
 239 #define CLI_SESS_SNOOP          0x02
 240 #define CLI_SESS_NOSNOOP        0x04
 241 #define CLI_SESS_THROTTLE       0x08
 242 #define CLI_SESS_NOTHROTTLE     0x10
 243 #define CLI_SESS_FILTER         0x20
 244 #define CLI_SESS_NOFILTER       0x40
 245
 246 struct cli_tunnel_actions {
 247         char action;
 248 };
 249
 250 #define CLI_TUN_KILL            0x01
 251
 252 // structures
 253 typedef struct                  // route
 254 {
 255         in_addr_t ip;
 256         int prefixlen;
 257 }
 258 routet;
 259
 260 // structures
 261 typedef struct                  // route
 262 {
 263         struct in6_addr ipv6route;      // Static IPv6 route
 264         uint8_t ipv6prefixlen;          // IPv6 route prefix length
 265 }
 266 routet6;
 267
 268 typedef struct controls         // control message
 269 {
 270         struct controls *next;  // next in queue
 271         uint16_t length;        // length
 272         uint8_t buf[MAXCONTROL];
 273 }
 274 controlt;
 275
 276 typedef struct {
 277         uint8_t length;                 // Endpoint Discriminator length
 278         uint8_t addr_class;             // Endpoint Discriminator class
 279         uint8_t address[MAXADDRESS];    // Endpoint Discriminator address
 280 } epdist;
 281
 282 typedef struct {
 283         sessionidt sid;                 // Fragment originating session
 284         tunnelidt tid;                  // Fragment originating tunnel
 285         uint8_t flags;                  // MP frame flags
 286         uint32_t seq;                   // fragment seq num
 287         uint32_t jitteravg;
 288         uint16_t length;                // Fragment length
 289         uint8_t data[MAXFRAGLEN];       // Fragment data
 290 } fragmentt;
 291
 292 typedef struct
 293 {
 294         sessionidt next;                // next session in linked list
 295         sessionidt far;                 // far end session ID
 296         tunnelidt tunnel;               // near end tunnel ID
 297         uint8_t flags;                  // session flags: see SESSION_*
 298         struct {
 299                 uint8_t phase;          // PPP phase
 300                 uint8_t lcp:4;          //   LCP    state
 301                 uint8_t ipcp:4;         //   IPCP   state
 302                 uint8_t ipv6cp:4;       //   IPV6CP state
 303                 uint8_t ccp:4;          //   CCP    state
 304         } ppp;
 305         uint16_t mru;                   // maximum receive unit
 306         in_addr_t ip;                   // IP of session set by RADIUS response (host byte order).
 307         int ip_pool_index;              // index to IP pool
 308         uint32_t unique_id;             // unique session id
 309         uint32_t magic;                 // ppp magic number
 310         uint32_t pin, pout;             // packet counts
 311         uint32_t cin, cout;             // byte counts
 312         uint32_t cin_wrap, cout_wrap;   // byte counter wrap count (RADIUS accounting giagawords)
 313         uint32_t cin_delta, cout_delta; // byte count changes (for dump_session())
 314         uint16_t throttle_in;           // upstream throttle rate (kbps)
 315         uint16_t throttle_out;          // downstream throttle rate
 316         uint8_t filter_in;              // input filter index (to ip_filters[N-1]; 0 if none)
 317         uint8_t filter_out;             // output filter index
 318         uint16_t snoop_port;            // Interception destination port
 319         in_addr_t snoop_ip;             // Interception destination IP
 320         clockt opened;                  // when started
 321         clockt die;                     // being closed, when to finally free
 322         uint32_t session_timeout;       // Maximum session time in seconds
 323         uint32_t idle_timeout;          // Maximum idle time in seconds
 324         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 325         time_t last_data;               // Last data packet to/from the user (used for idle timeouts)
 326         in_addr_t dns1, dns2;           // DNS servers
 327         routet route[MAXROUTE];         // static routes
 328         uint16_t tbf_in;                // filter bucket for throttling in from the user.
 329         uint16_t tbf_out;               // filter bucket for throttling out to the user.
 330         int random_vector_length;
 331         uint8_t random_vector[MAXTEL];
 332         char user[MAXUSER];             // user (needed in session for radius stop messages)
 333         char called[MAXTEL];            // called number
 334         char calling[MAXTEL];           // calling number
 335         uint32_t tx_connect_speed;
 336         uint32_t rx_connect_speed;
 337         clockt timeout;                 // Session timeout
 338         uint32_t mrru;                  // Multilink Max-Receive-Reconstructed-Unit
 339         epdist epdis;                   // Multilink Endpoint Discriminator
 340         bundleidt bundle;               // Multilink Bundle Identifier
 341         uint8_t mssf;                   // Multilink Short Sequence Number Header Format
 342         uint8_t walled_garden;          // is this session gardened?
 343         uint8_t classlen;               // class (needed for radius accounting messages)
 344         char class[MAXCLASS];
 345         sessionidt forwardtosession;    // LNS id_session to forward
 346         uint8_t src_hwaddr[ETH_ALEN];   // MAC addr source (for pppoe sessions 6 bytes)
 347         uint32_t dhcpv6_prefix_iaid;    // prefix iaid requested by client
 348         uint32_t dhcpv6_iana_iaid;              // iaid of iana requested by client
 349         struct in6_addr ipv6address;    // Framed Ipv6 address
 350         struct dhcp6_opt_clientid dhcpv6_client_id; // Size max (headers + DUID)
 351         routet6 route6[MAXROUTE6];              // static IPv6 routes
 352         char reserved[4];               // Space to expand structure without changing HB_VERSION
 353 }
 354 sessiont;
 355
 356 typedef struct
 357 {
 358         uint32_t tx_rate;
 359         uint32_t prev_coutgrp;
 360         sessionidt sid;
 361         uint8_t weight;
 362 }
 363 groupsesslistt;
 364
 365 typedef struct
 366 {
 367         int state;                              // current state (groupestate enum)
 368         uint32_t time_changed;
 369         groupidt prev;
 370         sessionidt smax;
 371         sessionidt smin;
 372         groupsesslistt sesslist[MAXSESSINGRP];
 373         routet route[MAXROUTEINGRP];            // static routes
 374         uint8_t nbroutesgrp;
 375         uint8_t nbsession;
 376 }
 377 groupsesst;
 378
 379 union iphash
 380 {
 381         sessionidt sess;
 382         union iphash *idx;
 383 };                      // Mapping from IP address to session structures.
 384
 385 typedef struct
 386 {
 387         int state;                              // current state (bundlestate enum)
 388         uint32_t seq_num_t;                     // Sequence Number (transmission)
 389         uint32_t timeout;                       // Session-Timeout for bundle
 390         uint32_t max_seq;                       // Max value of sequence number field
 391         uint8_t num_of_links;                   // Number of links joint to this bundle
 392         uint32_t online_time;                   // The time this bundle is online
 393         clockt last_check;                      // Last time the timeout is checked
 394         uint32_t mrru;                          // Multilink Max-Receive-Reconstructed-Unit
 395         uint8_t mssf;                           // Multilink Short Sequence Number Header Format
 396         epdist epdis;                           // Multilink Endpoint Discriminator
 397         char user[MAXUSER];                     // Needed for matching member links
 398         sessionidt current_ses;                 // Current session to use for sending (used in RR load-balancing)
 399         sessionidt members[MAXBUNDLESES];       // Array for member links sessions
 400 }
 401 bundlet;
 402
 403 typedef struct
 404 {
 405         fragmentt fragment[MAXFRAGNUM];
 406         uint8_t reassembled_frame[MAXETHER];    // The reassembled frame
 407         uint16_t re_frame_len;                  // The reassembled frame length
 408         uint16_t re_frame_begin_index, re_frame_end_index;      // reassembled frame begin index, end index respectively
 409         uint16_t start_index, end_index;        // start and end sequence numbers available on the fragments array respectively
 410         uint32_t M;                             // Minumum frame sequence number received over all bundle members
 411         uint32_t start_seq;                     // Last received frame sequence number (bearing B bit)
 412 }
 413 fragmentationt;
 414
 415 #define AUTHPAP         1       // allow PAP
 416 #define AUTHCHAP        2       // allow CHAP
 417
 418 typedef struct
 419 {
 420         // packet counters
 421         uint32_t pin;
 422         uint32_t pout;
 423
 424         // byte counters
 425         uint32_t cin;
 426         uint32_t cout;
 427
 428         // PPP restart timer/counters
 429         struct {
 430                 time_t restart;
 431                 int conf_sent;
 432                 int nak_sent;
 433         } lcp, ipcp, ipv6cp, ccp;
 434
 435         // identifier for Protocol-Reject, Code-Reject
 436         uint8_t lcp_ident;
 437
 438         // authentication to use
 439         int lcp_authtype;
 440
 441         // our MRU
 442         uint16_t ppp_mru;
 443
 444         // our MRRU
 445         uint16_t mp_mrru;
 446
 447         // our mssf
 448         uint16_t mp_mssf;
 449
 450         // our Endpoint Discriminator
 451         in_addr_t mp_epdis;
 452
 453         // DoS prevention
 454         clockt last_packet_out;
 455         uint32_t packets_out;
 456         uint32_t packets_dropped;
 457
 458         // RADIUS session in use
 459         uint16_t radius;
 460
 461         // interim RADIUS
 462         time_t last_interim;
 463
 464         // last LCP Echo
 465         time_t last_echo;
 466
 467         // Last Multilink frame sequence number received
 468         uint32_t last_seq;
 469
 470         // jitter average of the session
 471         uint32_t jitteravg;
 472         // time in milliseconds of the last fragment.
 473         uint64_t prev_time;
 474 } sessionlocalt;
 475
 476 // session flags
 477 #define SESSION_PFC     (1 << 0)        // use Protocol-Field-Compression
 478 #define SESSION_ACFC    (1 << 1)        // use Address-and-Control-Field-Compression
 479 #define SESSION_STARTED (1 << 2)        // RADIUS Start record sent
 480
 481 // 328 bytes per tunnel
 482 typedef struct
 483 {
 484         tunnelidt far;          // far end tunnel ID
 485         in_addr_t ip;           // Ip for far end
 486         uint16_t port;          // port for far end
 487         uint16_t window;        // Rx window
 488         uint16_t nr;            // next receive
 489         uint16_t ns;            // next send
 490         int state;              // current state (tunnelstate enum)
 491         clockt last;            // when last control message sent (used for resend timeout)
 492         clockt retry;           // when to try resending pending control
 493         clockt die;             // being closed, when to finally free
 494         clockt lastrec;         // when the last control message was received
 495         char hostname[128];     // tunnel hostname
 496         char vendor[128];       // LAC vendor
 497         uint8_t try;            // number of retrys on a control message
 498         uint16_t controlc;      // outstaind messages in queue
 499         controlt *controls;     // oldest message
 500         controlt *controle;     // newest message
 501         uint16_t isremotelns;   // != 0 if the tunnel is to remote LNS (== index on the conf remote lns)
 502         uint16_t indexudp;      // Index UDP file handle (in udpfd[])
 503         char reserved[12];              // Space to expand structure without changing HB_VERSION
 504 }
 505 tunnelt;
 506
 507 // 164 bytes per radius session
 508 typedef struct                  // outstanding RADIUS requests
 509 {
 510         sessionidt session;     // which session this applies to
 511         hasht auth;             // request authenticator
 512         clockt retry;           // when to try next
 513         char pass[129];         // password
 514         uint8_t id;             // ID for PPP response
 515         uint8_t try;            // which try we are on
 516         uint8_t state;          // state of radius requests
 517         uint8_t chap;           // set if CHAP used (is CHAP identifier)
 518         uint8_t term_cause;     // Stop record: Acct-Terminate-Cause
 519         char const *term_msg;   //   terminate reason
 520 }
 521 radiust;
 522
 523 typedef struct
 524 {
 525         in_addr_t       address;        // Host byte order..
 526         char            assigned;       // 1 if assigned, 0 if free
 527         sessionidt      session;
 528         clockt          last;           // last used
 529         char            user[129];      // user (try to have ip addresses persistent)
 530 }
 531 ippoolt;
 532
 533 #ifdef RINGBUFFER
 534 struct Tringbuffer
 535 {
 536         struct {
 537                 char level;
 538                 sessionidt session;
 539                 tunnelidt tunnel;
 540                 char message[MAX_LOG_LENGTH];
 541         } buffer[RINGBUFFER_SIZE];
 542         int head;
 543         int tail;
 544 };
 545 #endif
 546
 547 /*
 548  * Possible tunnel states
 549  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 550  */
 551 enum
 552 {
 553         TUNNELFREE,             // Not in use
 554         TUNNELOPEN,             // Active tunnel
 555         TUNNELDIE,              // Currently closing
 556         TUNNELOPENING,          // Busy opening
 557         TUNNELUNDEF,            // Undefined
 558 };
 559
 560 enum
 561 {
 562         BUNDLEFREE,             // Not in use
 563         BUNDLEOPEN,             // Active bundle
 564         BUNDLEUNDEF,            // Undefined
 565 };
 566
 567 enum
 568 {
 569         GROUPEFREE,             // Not in use
 570         GROUPEOPEN,             // Active bundle
 571         GROUPEUNDEF             // Undefined
 572 };
 573
 574 enum
 575 {
 576         NULLCLASS = 0,          //End Point Discriminator classes
 577         LOCALADDR,
 578         IPADDR,
 579         IEEEMACADDR,
 580         PPPMAGIC,
 581         PSNDN,
 582 };
 583
 584 enum
 585 {
 586         RADIUSNULL,             // Not in use
 587         RADIUSCHAP,             // sending CHAP down PPP
 588         RADIUSAUTH,             // sending auth to RADIUS server
 589         RADIUSSTART,            // sending start accounting to RADIUS server
 590         RADIUSSTOP,             // sending stop accounting to RADIUS server
 591         RADIUSINTERIM,          // sending interim accounting to RADIUS server
 592         RADIUSWAIT,             // waiting timeout before available, in case delayed replies
 593         RADIUSJUSTAUTH,         // sending auth to RADIUS server, just authentication, no ip assigning
 594 };
 595
 596 struct Tstats
 597 {
 598     time_t      start_time;
 599     time_t      last_reset;
 600
 601     uint32_t    tun_rx_packets;
 602     uint32_t    tun_tx_packets;
 603     uint32_t    tun_rx_bytes;
 604     uint32_t    tun_tx_bytes;
 605     uint32_t    tun_rx_errors;
 606     uint32_t    tun_tx_errors;
 607     uint32_t    tun_rx_dropped;
 608
 609     uint32_t    tunnel_rx_packets;
 610     uint32_t    tunnel_tx_packets;
 611     uint32_t    tunnel_rx_bytes;
 612     uint32_t    tunnel_tx_bytes;
 613     uint32_t    tunnel_rx_errors;
 614     uint32_t    tunnel_tx_errors;
 615
 616     uint32_t    tunnel_retries;
 617     uint32_t    radius_retries;
 618
 619     uint32_t    arp_sent;
 620
 621     uint32_t    packets_snooped;
 622
 623     uint32_t    tunnel_created;
 624     uint32_t    session_created;
 625     uint32_t    tunnel_timeout;
 626     uint32_t    session_timeout;
 627     uint32_t    radius_timeout;
 628     uint32_t    radius_overflow;
 629     uint32_t    tunnel_overflow;
 630     uint32_t    session_overflow;
 631
 632     uint32_t    ip_allocated;
 633     uint32_t    ip_freed;
 634
 635     uint32_t    c_forwarded;
 636     uint32_t    recv_forward;
 637
 638     uint32_t    select_called;
 639     uint32_t    multi_read_used;
 640     uint32_t    multi_read_exceeded;
 641
 642 #ifdef STATISTICS
 643     uint32_t    call_processtun;
 644     uint32_t    call_processipout;
 645     uint32_t    call_processipv6out;
 646     uint32_t    call_processudp;
 647     uint32_t    call_sessionbyip;
 648     uint32_t    call_sessionbyipv6;
 649     uint32_t    call_sessionbyipv6new;
 650     uint32_t    call_sessionbyuser;
 651     uint32_t    call_sendarp;
 652     uint32_t    call_sendipcp;
 653     uint32_t    call_sendipv6cp;
 654     uint32_t    call_processipv6cp;
 655     uint32_t    call_tunnelsend;
 656     uint32_t    call_sessionkill;
 657     uint32_t    call_sessionshutdown;
 658     uint32_t    call_tunnelkill;
 659     uint32_t    call_tunnelshutdown;
 660     uint32_t    call_assign_ip_address;
 661     uint32_t    call_free_ip_address;
 662     uint32_t    call_dump_acct_info;
 663     uint32_t    call_sessionsetup;
 664     uint32_t    call_processpap;
 665     uint32_t    call_processchap;
 666     uint32_t    call_processlcp;
 667     uint32_t    call_processipcp;
 668     uint32_t    call_processipin;
 669     uint32_t    call_processipv6in;
 670     uint32_t    call_processccp;
 671     uint32_t    call_sendchap;
 672     uint32_t    call_processrad;
 673     uint32_t    call_radiussend;
 674     uint32_t    call_radiusretry;
 675     uint32_t    call_random_data;
 676     uint32_t    call_dhcpv6_process;
 677 #endif
 678 };
 679
 680 #ifdef STATISTICS
 681
 682 #ifdef STAT_CALLS
 683 #define CSTAT(x)        STAT(call_ ## x)
 684 #else
 685 #define CSTAT(x)
 686 #endif
 687
 688 #define STAT(x)         (_statistics->x++)
 689 #define INC_STAT(x,y)   (_statistics->x += (y))
 690 #define GET_STAT(x)     (_statistics->x)
 691 #define SET_STAT(x, y)  (_statistics->x = (y))
 692 #else
 693 #define CSTAT(x)
 694 #define STAT(x)
 695 #define INC_STAT(x,y)
 696 #define GET_STAT(x)     0
 697 #define SET_STAT(x, y)
 698 #endif
 699
 700 #ifndef IFNAMSIZ
 701 # define IFNAMSIZ 16
 702 #endif
 703
 704 typedef struct
 705 {
 706         int             debug;                          // debugging level
 707         time_t          start_time;                     // time when l2tpns was started
 708         char            bandwidth[256];                 // current bandwidth
 709         char            pid_file[256];                  // file to write PID to on startup
 710         int             wrote_pid;
 711         clockt          current_time;                   // 1/10ths of a second since the process started.
 712                                                         // means that we can only run a given process
 713                                                         // for 13 years without re-starting!
 714
 715         char            config_file[128];
 716         int             reload_config;                  // flag to re-read config (set by cli)
 717         int             multi_read_count;               // amount of packets to read per fd in processing loop
 718
 719         char            tundevicename[IFNAMSIZ];                // tun device name
 720         char            log_filename[128];
 721
 722         char            l2tp_secret[64];                // L2TP shared secret
 723         int             l2tp_mtu;                       // MTU of interface used for L2TP
 724
 725         char            random_device[256];             // random device path, defaults to RANDOMDEVICE
 726
 727         int             ppp_restart_time;               // timeout for PPP restart
 728         int             ppp_max_configure;              // max lcp configure requests to send
 729         int             ppp_max_failure;                // max lcp configure naks to send
 730
 731         char            radiussecret[64];
 732         int             radius_accounting;
 733         int             radius_interim;
 734         in_addr_t       radiusserver[MAXRADSERVER];     // radius servers
 735         uint16_t        radiusport[MAXRADSERVER];       // radius base ports
 736         uint8_t         numradiusservers;               // radius server count
 737
 738         uint16_t        radius_dae_port;                // port for radius DAE
 739         uint16_t        radius_bind_min;                // port range for udp sockets used to send/recv radius packets
 740         uint16_t        radius_bind_max;
 741
 742         char            radius_authtypes_s[32];         // list of valid authentication types (chap, pap) in order of preference
 743         int             radius_authtypes;
 744         int             radius_authprefer;
 745
 746         int             allow_duplicate_users;          // allow multiple logins with the same username
 747         int             kill_timedout_sessions;         // kill authenticated sessions with "session_timeout == 0"
 748
 749         in_addr_t       default_dns1, default_dns2;
 750
 751         unsigned long   rl_rate;                        // default throttle rate
 752         int             num_tbfs;                       // number of throttle buckets
 753
 754         char            accounting_dir[128];
 755         int             account_all_origin; // Accouting all origin (LAC data + Remote LNS Data + PPPOE data)
 756         in_addr_t       bind_address;
 757         in_addr_t       peer_address;
 758         int             send_garp;                      // Set to true to garp for vip address on startup
 759
 760         int             dump_speed;
 761         char            plugins[64][MAXPLUGINS];
 762         char            old_plugins[64][MAXPLUGINS];
 763
 764         int             next_tbf;                       // Next HTB id available to use
 765         int             scheduler_fifo;                 // If the system has multiple CPUs, use FIFO scheduling
 766                                                         // policy for this process.
 767         int             lock_pages;                     // Lock pages into memory.
 768         int             icmp_rate;                      // Max number of ICMP unreachable per second to send
 769         int             max_packets;                    // DoS prevention: per session limit of packets/0.1s
 770         char            epdis_addr[20];                 // MP Endpoint Discriminator address
 771
 772         in_addr_t       cluster_address;                // Multicast address of cluster.
 773                                                         // Send to this address to have everyone hear.
 774         char            cluster_interface[64];          // Which interface to listen for multicast on.
 775         int             cluster_iam_master;             // Are we the cluster master???
 776         int             cluster_iam_uptodate;           // Set if we've got a full set of state from the master.
 777         in_addr_t       cluster_master_address;         // The network address of the cluster master.
 778                                                         // Zero if i am the cluster master.
 779         int             cluster_seq_number;             // Sequence number of the next heartbeat we'll send out
 780                                                         // (or the seq number we're next expecting if we're a slave).
 781         int             cluster_undefined_sessions;     // How many sessions we're yet to receive from the master.
 782         int             cluster_undefined_bundles;      // How many bundles we're yet to receive from the master.
 783         int             cluster_undefined_tunnels;      // How many tunnels we're yet to receive from the master.
 784         int             cluster_undefined_groupes;      // How many groupes we're yet to receive from the master.
 785         int             cluster_highest_sessionid;
 786         int             cluster_highest_bundleid;
 787         int             cluster_highest_groupeid;
 788         int             cluster_highest_tunnelid;
 789         clockt          cluster_last_hb;                // Last time we saw a heartbeat from the master.
 790         int             cluster_last_hb_ver;            // Heartbeat version last seen from master
 791         int             cluster_num_changes;            // Number of changes queued.
 792
 793         int             cluster_mcast_ttl;              // TTL for multicast packets
 794         int             cluster_hb_interval;            // How often to send a heartbeat.
 795         int             cluster_hb_timeout;             // How many missed heartbeats trigger an election.
 796         uint64_t        cluster_table_version;          // # state changes processed by cluster
 797
 798         struct in6_addr ipv6_prefix;                    // Our IPv6 network pool.
 799
 800
 801         int             cluster_master_min_adv;         // Master advertises routes while the number of up to date
 802                                                         // slaves is less than this value.
 803         in_addr_t       cli_bind_address;               // bind address for CLI
 804         char            hostname[MAXHOSTNAME];  // hostname (overridden by -h on command line)
 805         // Guest change
 806         char            guest_user[MAXUSER];            // Guest account username
 807
 808 #ifdef BGP
 809 #define BGP_NUM_PEERS   2
 810         uint16_t as_number;
 811         struct {
 812                 char name[64];
 813                 uint16_t as;
 814                 int keepalive;
 815                 int hold;
 816                 struct in_addr update_source;
 817         } neighbour[BGP_NUM_PEERS];
 818         in_addr_t       nexthop_address;
 819         struct in6_addr nexthop6_address;
 820 #endif
 821
 822         int echo_timeout; // Time between last packet sent and LCP ECHO generation
 823         int idle_echo_timeout; // Time between last packet seen and
 824                                                    // Drop sessions who have not responded within IDLE_ECHO_TIMEOUT seconds
 825         in_addr_t iftun_address;
 826         int disable_lac_func;
 827         int auth_tunnel_change_addr_src;
 828         int highest_rlnsid;
 829         uint16_t bind_portremotelns;
 830         in_addr_t bind_address_remotelns;
 831         char pppoe_if_to_bind[IFNAMSIZ];        // Name pppoe interface to bind
 832         char pppoe_service_name[64];    // pppoe service name
 833         char pppoe_ac_name[64];
 834         uint8_t pppoe_hwaddr[ETH_ALEN]; // MAC addr of interface pppoe to bind
 835         int pppoe_only_equal_svc_name; // Accept only PADI with service-name equal to server
 836         int disable_sending_hello; // Disable l2tp sending HELLO message for Apple compatibility.
 837         int disable_no_spoof; // Disable no spoof (permit load balancing client --> internet)
 838         int nbudpfd; // number UDP file handle
 839         int nbmultiaddress; // number multi address to bind
 840         int indexlacudpfd;      // Index UDP LAC file handle (in udpfd[])
 841         int nbmultihostname;    // number hostname, normally the same number as the nbudpfd
 842         int grp_txrate_average_time; // caculation txrate average time (default 10s)
 843         int no_throttle_local_IP;       // no throttle traffic from session to session
 844         in_addr_t bind_n_address[MAX_BINDADDR];
 845         in_addr_t iftun_n_address[MAX_BINDADDR];
 846         char bind_multi_address[256];
 847         char multi_hostname[512];
 848         char multi_n_hostname[MAX_NBHOSTNAME][MAXHOSTNAME];     // list hostname
 849         struct in6_addr default_ipv6_dns1;
 850         struct in6_addr default_ipv6_dns2;
 851         uint32_t dhcp6_preferred_lifetime;              // preferred lifetime (see rfc3315)
 852         uint32_t dhcp6_valid_lifetime;          // valid lifetime (see rfc3315)
 853         uint32_t dhcp6_server_duid;             // DUID of dhcpv6 server (see rfc3315)
 854         char default_ipv6_domain_list[255];
 855 } configt;
 856
 857 enum config_typet { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IPv4, IPv6 };
 858 typedef struct
 859 {
 860         char *key;
 861         int offset;
 862         int size;
 863         enum config_typet type;
 864 } config_descriptt;
 865
 866 typedef struct
 867 {
 868         uint8_t op;     // operation
 869 #define FILTER_PORT_OP_NONE     0 // all ports match
 870 #define FILTER_PORT_OP_EQ       1
 871 #define FILTER_PORT_OP_NEQ      2
 872 #define FILTER_PORT_OP_GT       3
 873 #define FILTER_PORT_OP_LT       4
 874 #define FILTER_PORT_OP_RANGE    5
 875         uint16_t port;  // port (host byte order)
 876         uint16_t port2; // range
 877 } ip_filter_portt;
 878
 879 typedef struct
 880 {
 881         int action;             // permit/deny
 882 #define FILTER_ACTION_DENY      1
 883 #define FILTER_ACTION_PERMIT    2
 884         uint8_t proto;          // protocol: IPPROTO_* (netinet/in.h)
 885         in_addr_t src_ip;       // source ip (network byte order)
 886         in_addr_t src_wild;
 887         ip_filter_portt src_ports;
 888         in_addr_t dst_ip;       // dest ip
 889         in_addr_t dst_wild;
 890         ip_filter_portt dst_ports;
 891         uint8_t frag;           // apply to non-initial fragments
 892         uint8_t tcp_flag_op;    // match type: any, all, established
 893 #define FILTER_FLAG_OP_ANY      1
 894 #define FILTER_FLAG_OP_ALL      2
 895 #define FILTER_FLAG_OP_EST      3
 896         uint8_t tcp_sflags;     // flags set
 897         uint8_t tcp_cflags;     // flags clear
 898         uint32_t counter;       // match count
 899 } ip_filter_rulet;
 900
 901 #define TCP_FLAG_FIN    0x01
 902 #define TCP_FLAG_SYN    0x02
 903 #define TCP_FLAG_RST    0x04
 904 #define TCP_FLAG_PSH    0x08
 905 #define TCP_FLAG_ACK    0x10
 906 #define TCP_FLAG_URG    0x20
 907
 908 #define MAXFILTER               32
 909 #define MAXFILTER_RULES         32
 910 typedef struct
 911 {
 912         char name[32];          // ACL name
 913         int extended;           // type: 0 = standard, 1 = extended
 914         ip_filter_rulet rules[MAXFILTER_RULES];
 915         int used;               // session ref count
 916 } ip_filtert;
 917
 918 // CDN result/error codes
 919 #define CDN_NONE                        0, 0
 920 #define CDN_TRY_ANOTHER                 2, 7
 921 #define CDN_ADMIN_DISC                  3, 0
 922 #define CDN_UNAVAILABLE                 4, 0
 923
 924 // RADIUS Acct-Terminate-Cause values
 925 #define TERM_USER_REQUEST               1
 926 #define TERM_LOST_CARRIER               2
 927 #define TERM_LOST_SERVICE               3
 928 #define TERM_IDLE_TIMEOUT               4
 929 #define TERM_SESSION_TIMEOUT            5
 930 #define TERM_ADMIN_RESET                6
 931 #define TERM_ADMIN_REBOOT               7
 932 #define TERM_PORT_ERROR                 8
 933 #define TERM_NAS_ERROR                  9
 934 #define TERM_NAS_REQUEST                10
 935 #define TERM_NAS_REBOOT                 11
 936 #define TERM_PORT_UNNEEDED              12
 937 #define TERM_PORT_PREEMPTED             13
 938 #define TERM_PORT_SUSPENDED             14
 939 #define TERM_SERVICE_UNAVAILABLE        15
 940 #define TERM_CALLBACK                   16
 941 #define TERM_USER_ERROR                 17
 942 #define TERM_HOST_REQUEST               18
 943 #define TERM_SUPPLICANT_RESTART         19
 944 #define TERM_REAUTHENTICATION_FAILURE   20
 945 #define TERM_PORT_REINIT                21
 946 #define TERM_PORT_DISABLED              22
 947
 948 // on slaves, alow BGP to withdraw cleanly before exiting
 949 #define QUIT_DELAY      5
 950
 951 // quit actions (master)
 952 #define QUIT_FAILOVER   1 // SIGTERM: exit when all control messages have been acked (for cluster failover)
 953 #define QUIT_SHUTDOWN   2 // SIGQUIT: shutdown sessions/tunnels, reject new connections
 954
 955 // arp.c
 956 void sendarp(int ifr_idx, const unsigned char* mac, in_addr_t ip);
 957
 958
 959 // ppp.c
 960 void processpap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 961 void processchap(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 962 void lcp_open(sessionidt s, tunnelidt t);
 963 void lcp_restart(sessionidt s);
 964 void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 965 void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 966 void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 967 void processipin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 968 void processmpin(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 969 void processmpframe(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint8_t extra);
 970 void processipv6in(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 971 void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l);
 972 void sendchap(sessionidt s, tunnelidt t);
 973 uint8_t *makeppp(uint8_t *b, int size, uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits);
 974 uint8_t *opt_makeppp(uint8_t *p, int l, sessionidt s, tunnelidt t, uint16_t mtype, uint8_t prio, bundleidt bid, uint8_t mp_bits);
 975 void sendlcp(sessionidt s, tunnelidt t);
 976 void send_ipin(sessionidt s, uint8_t *buf, int len);
 977 void sendccp(sessionidt s, tunnelidt t);
 978 void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t proto);
 979 int join_bundle(sessionidt s);
 980
 981
 982 // radius.c
 983 void initrad(void);
 984 void radiussend(uint16_t r, uint8_t state);
 985 void processrad(uint8_t *buf, int len, char socket_index);
 986 void radiusretry(uint16_t r);
 987 uint16_t radiusnew(sessionidt s);
 988 void radiusclear(uint16_t r, sessionidt s);
 989 void processdae(uint8_t *buf, int len, struct sockaddr_in *addr, int alen, struct in_addr *local);
 990 int rad_tunnel_pwdecode(uint8_t *pl2tpsecret, size_t *pl2tpsecretlen, const char *radiussecret, const uint8_t * auth);
 991
 992 // l2tpns.c
 993 clockt backoff(uint8_t try);
 994 void send_ipv6_ra(sessionidt s, tunnelidt t, struct in6_addr *ip);
 995 void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add);
 996 sessionidt sessionbyip(in_addr_t ip);
 997 sessionidt sessionbyipv6(struct in6_addr ip);
 998 sessionidt sessionbyipv6new(struct in6_addr ip);
 999 sessionidt sessionbyuser(char *username);
1000 void increment_counter(uint32_t *counter, uint32_t *wrap, uint32_t delta);
1001 void random_data(uint8_t *buf, int len);
1002 void sessionkill(sessionidt s, char *reason);
1003 void sessionshutdown(sessionidt s, char const *reason, int cdn_result, int cdn_error, int term_cause);
1004 void filter_session(sessionidt s, int filter_in, int filter_out);
1005 void send_garp(in_addr_t ip);
1006 void tunnelsend(uint8_t *buf, uint16_t l, tunnelidt t);
1007 int tun_write(uint8_t *data, int size);
1008 void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp);
1009 void sendipcp(sessionidt s, tunnelidt t);
1010 void sendipv6cp(sessionidt s, tunnelidt t);
1011 void processudp(uint8_t *buf, int len, struct sockaddr_in *addr, uint16_t indexudpfd);
1012 void processipout(uint8_t *buf, int len);
1013 void snoop_send_packet(uint8_t *packet, uint16_t size, in_addr_t destination, uint16_t port);
1014 int find_filter(char const *name, size_t len);
1015 int ip_filter(uint8_t *buf, int len, uint8_t filter);
1016 int cmd_show_ipcache(struct cli_def *cli, const char *command, char **argv, int argc);
1017 int cmd_show_hist_idle(struct cli_def *cli, const char *command, char **argv, int argc);
1018 int cmd_show_hist_open(struct cli_def *cli, const char *command, char **argv, int argc);
1019 void netlink_addattr(struct nlmsghdr *nh, int type, const void *data, int alen);
1020 ssize_t netlink_send(struct nlmsghdr *nh);
1021 void cache_ipmap(in_addr_t ip, sessionidt s);
1022 tunnelidt lac_new_tunnel();
1023 void lac_tunnelclear(tunnelidt t);
1024 void lac_send_SCCRQ(tunnelidt t, uint8_t * auth, unsigned int auth_len);
1025 void lac_send_ICRQ(tunnelidt t, sessionidt s);
1026 void lac_tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg);
1027
1028 // grpsess.c
1029 sessionidt grp_getnextsession(groupidt g, in_addr_t ip, in_addr_t ip_src);
1030 void grp_initdata(void);
1031 void grp_processvendorspecific(sessionidt s, uint8_t *pvs);
1032 groupidt grp_groupbysession(sessionidt s);
1033 groupidt grp_groupbyip(in_addr_t ip);
1034 void grp_setgrouproute(groupidt g, int add);
1035 void grp_time_changed(void);
1036 void grp_removesession(groupidt g, sessionidt s);
1037 int grp_cluster_load_groupe(groupidt g, groupsesst *new);
1038
1039 #undef LOG
1040 #undef LOG_HEX
1041 #define LOG(D, s, t, f, ...)    ({ if (D <= config->debug) _log(D, s, t, f, ## __VA_ARGS__); })
1042 #define LOG_HEX(D, t, d, s)     ({ if (D <= config->debug) _log_hex(D, t, d, s); })
1043
1044 void _log(int level, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 4, 5)));
1045 void _log_hex(int level, const char *title, const uint8_t *data, int maxsize);
1046
1047
1048 int sessionsetup(sessionidt s, tunnelidt t);
1049 int run_plugins(int plugin_type, void *data);
1050 void rebuild_address_pool(void);
1051 void throttle_session(sessionidt s, int rate_in, int rate_out);
1052 int load_session(sessionidt, sessiont *);
1053 void become_master(void);       // We're the master; kick off any required master initializations.
1054
1055
1056 // cli.c
1057 void init_cli();
1058 void cli_init_complete(char *hostname);
1059 void cli_do_file(FILE *fh);
1060 void cli_do(int sockfd);
1061 int cli_arg_help(struct cli_def *cli, int cr_ok, char *entry, ...);
1062
1063
1064 // icmp.c
1065 void host_unreachable(in_addr_t destination, uint16_t id, in_addr_t source, uint8_t *packet, int packet_len);
1066
1067
1068 extern tunnelt *tunnel;
1069 extern bundlet *bundle;
1070 extern sessiont *session;
1071 extern sessionlocalt *sess_local;
1072 extern ippoolt *ip_address_pool;
1073 extern groupsesst *grpsession;
1074 extern groupidt gnextgrpid;
1075 #define sessionfree (session[0].next)
1076
1077
1078 extern configt *config;
1079 extern time_t basetime;         // Time when this process started.
1080 extern time_t time_now;         // Seconds since EPOCH.
1081 extern char main_quit;
1082 extern uint32_t last_id;
1083 extern struct Tstats *_statistics;
1084 extern in_addr_t my_address;
1085 extern int clifd;
1086 extern int epollfd;
1087 extern int tunidx;              // ifr_ifindex of tun device
1088 extern union iphash ip_hash[256];
1089
1090 struct event_data {
1091         enum {
1092                 FD_TYPE_CLI,
1093                 FD_TYPE_CLUSTER,
1094                 FD_TYPE_TUN,
1095                 FD_TYPE_UDP,
1096                 FD_TYPE_CONTROL,
1097                 FD_TYPE_DAE,
1098                 FD_TYPE_RADIUS,
1099                 FD_TYPE_BGP,
1100                 FD_TYPE_NETLINK,
1101                 FD_TYPE_PPPOEDISC,
1102                 FD_TYPE_PPPOESESS
1103         } type;
1104         int index; // for RADIUS, BGP, UDP
1105 };
1106
1107 #define TIME (config->current_time)
1108
1109 extern uint16_t MRU;
1110 extern uint16_t MSS;
1111
1112 // macros for handling help in cli commands
1113 #define CLI_HELP_REQUESTED      (argc > 0 && argv[argc-1][strlen(argv[argc-1])-1] == '?')
1114 #define CLI_HELP_NO_ARGS        (argc > 1 || argv[0][1]) ? CLI_OK : cli_arg_help(cli, 1, NULL)
1115
1116 #endif /* __L2TPNS_H__ */