l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.7 2004-06-23 03:52:24 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 #include "config.h"
  18
  19 #define VERSION "2.0.0"
  20
  21 // Limits
  22 #define MAXTUNNEL       500             // could be up to 65535
  23 #define MAXSESSION      50000           // could be up to 65535
  24 #define MAXTBFS         6000            // Maximum token bucket filters. Might need up to 2 * session.
  25
  26 #define RADIUS_SHIFT    5
  27 #define RADIUS_MASK     ((unsigned short)(((unsigned short)~0) >> (16 - RADIUS_SHIFT)))
  28 #define MAXRADIUS       ((2 << (RADIUS_SHIFT - 1)) * 255)
  29
  30 #define T_UNDEF         (0xffff)        // A tunnel ID that won't ever be used. Mark session as undefined.
  31 #define T_FREE          (0)             // A tunnel ID that won't ever be used. Mark session as free.
  32
  33 #define MAXCONTROL      1000            // max length control message we ever send...
  34 #define MAXETHER        (1500+18)       // max packet we try sending to tap
  35 #define MAXTEL          96              // telephone number
  36 #define MAXPLUGINS      20              // maximum number of plugins to load
  37 #define MAXRADSERVER    10              // max radius servers
  38 #define MAXROUTE        10              // max static routes per session
  39 #define MAXIPPOOL       131072          // max number of ip addresses in pool
  40 #define RINGBUFFER_SIZE 10000           // Number of ringbuffer entries to allocate
  41 #define MAX_LOG_LENGTH  512             // Maximum size of log message
  42 #define ECHO_TIMEOUT    60              // Time between last packet sent and LCP ECHO generation
  43 #define IDLE_TIMEOUT    240             // Time between last packet sent and LCP ECHO generation
  44
  45 // Constants
  46 #ifndef PLUGINDIR
  47 #define PLUGINDIR       LIBDIR                  // Plugins
  48 #endif
  49
  50 #ifndef PLUGINCONF
  51 #define PLUGINCONF      ETCDIR                  // Plugin config dir
  52 #endif
  53
  54 #ifndef DATADIR
  55 #define DATADIR         "/tmp"
  56 #endif
  57
  58 #ifndef FLASHDIR
  59 #define FLASHDIR        ETCDIR
  60 #endif
  61
  62 #define TAPDEVICE       "/dev/net/tun"
  63 #define UDP             17
  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 RADAPORT        1646            // old radius accounting port
  72 #define PKTARP          0x0806          // ARP packet type
  73 #define PKTIP           0x0800          // IP packet type
  74 #define PSEUDOMAC       0x0200          // pseudo MAC prefix (local significant MAC)
  75 #define PPPPAP          0xC023
  76 #define PPPCHAP         0xC223
  77 #define PPPLCP          0xC021
  78 #define PPPIPCP         0x8021
  79 #define PPPCCP          0x80FD
  80 #define PPPIP           0x0021
  81 #define PPPMP           0x003D
  82 #define MIN_IP_SIZE     0x19
  83 enum
  84 {
  85         ConfigReq = 1,
  86         ConfigAck,
  87         ConfigNak,
  88         ConfigRej,
  89         TerminateReq,
  90         TerminateAck,
  91         CodeRej,
  92         ProtocolRej,
  93         EchoReq,
  94         EchoReply,
  95         DiscardRequest
  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 // dump header: update number if internal format changes
 110 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
 111
 112 // structures
 113 typedef struct routes           // route
 114 {
 115         ipt ip;
 116         ipt mask;
 117 }
 118 routet;
 119
 120 typedef struct controls         // control message
 121 {
 122         struct controls *next;  // next in queue
 123         u16 length;             // length
 124         u8 buf[MAXCONTROL];
 125 }
 126 controlt;
 127
 128 // 336 bytes per session
 129 typedef struct sessions
 130 {
 131         sessionidt next;                // next session in linked list
 132         sessionidt far;                 // far end session ID
 133         tunnelidt tunnel;               // tunnel ID
 134         ipt ip;                         // IP of session set by RADIUS response (host byte order).
 135         int ip_pool_index;              // index to IP pool
 136         unsigned long sid;              // session id for hsddb
 137         u16 nr;                         // next receive
 138         u16 ns;                         // next send
 139         u32 magic;                      // ppp magic number
 140         u32 cin, cout;                  // byte counts
 141         u32 pin, pout;                  // packet counts
 142         u32 total_cin;                  // This counter is never reset while a session is open
 143         u32 total_cout;                 // This counter is never reset while a session is open
 144         u32 id;                         // session id
 145         u32 throttle;                   // non-zero if this session is throttled.
 146         clockt opened;                  // when started
 147         clockt die;                     // being closed, when to finally free
 148         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 149         ipt dns1, dns2;                 // DNS servers
 150         routet route[MAXROUTE];         // static routes
 151         u16 radius;                     // which radius session is being used (0 for not waiting on authentication)
 152         u16 mru;                        // maximum receive unit
 153         u16 tbf_in;                     // filter bucket for throttling in from the user.
 154         u16 tbf_out;                    // filter bucket for throttling out to the user.
 155         u8 l2tp_flags;                  // various bit flags from the ICCN on the l2tp tunnel.
 156         u8 walled_garden;               // is this session gardened?
 157         u8 flags1;                      // additional flags (currently unused);
 158         char random_vector[MAXTEL];
 159         int random_vector_length;
 160         char user[129];                 // user (needed in seesion for radius stop messages) (can we reduce this? --mo)
 161         char called[MAXTEL];            // called number
 162         char calling[MAXTEL];           // calling number
 163         u32 tx_connect_speed;
 164         u32 rx_connect_speed;
 165         u32 flags;                      // Various session flags.
 166         ipt snoop_ip;                   // Interception destination IP
 167         u16 snoop_port;                 // Interception destination port
 168         char reserved[28];              // Space to expand structure without changing HB_VERSION
 169 }
 170 sessiont;
 171
 172 #define SF_IPCP_ACKED   (1<<0)          // Has this session seen an IPCP Ack?
 173
 174 typedef struct {
 175         u32     cin;
 176         u32     cout;
 177 } sessioncountt;
 178
 179 #define SESSIONPFC      1            // PFC negotiated flags
 180 #define SESSIONACFC     2           // ACFC negotiated flags
 181
 182 // 168 bytes per tunnel
 183 typedef struct tunnels
 184 {
 185         tunnelidt far;          // far end tunnel ID
 186         ipt ip;                 // Ip for far end
 187         portt port;             // port for far end
 188         u16 window;             // Rx window
 189         u16 nr;                 // next receive
 190         u16 ns;                 // next send
 191         int state;              // current state (tunnelstate enum)
 192         clockt last;            // when last control message sent (used for resend timeout)
 193         clockt retry;           // when to try resenting pending control
 194         clockt die;             // being closed, when to finally free
 195         clockt lastrec;         // when the last control message was received
 196         char hostname[128];     // tunnel hostname
 197         char vendor[128];       // LAC vendor
 198         u8 try;                 // number of retrys on a control message
 199         u16 controlc;           // outstaind messages in queue
 200         controlt *controls;     // oldest message
 201         controlt *controle;     // newest message
 202 }
 203 tunnelt;
 204
 205 // 180 bytes per radius session
 206 typedef struct radiuss          // outstanding RADIUS requests
 207 {
 208         sessionidt session;     // which session this applies to
 209         hasht auth;             // request authenticator
 210         clockt retry;           // when to try next
 211         char calling[MAXTEL];   // calling number
 212         char pass[129];         // password
 213         u8 id;                  // ID for PPP response
 214         u8 try;                 // which try we are on
 215         u8 state;               // state of radius requests
 216         u8 chap;                // set if CHAP used (is CHAP identifier)
 217 }
 218 radiust;
 219
 220 typedef struct
 221 {
 222         ipt             address;        // Host byte order..
 223         char            assigned;       // 1 if assigned, 0 if free
 224         sessionidt      session;
 225         clockt          last;           // last used
 226         char            user[129];      // user (try to have ip addresses persistent)
 227 }
 228 ippoolt;
 229
 230 #ifdef RINGBUFFER
 231 struct Tringbuffer
 232 {
 233         struct {
 234                 char level;
 235                 sessionidt session;
 236                 tunnelidt tunnel;
 237                 ipt address;
 238                 char message[MAX_LOG_LENGTH];
 239         } buffer[RINGBUFFER_SIZE];
 240         int head;
 241         int tail;
 242 };
 243 #endif
 244
 245 /*
 246  * Possible tunnel states
 247  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 248  */
 249 enum
 250 {
 251         TUNNELFREE,             // Not in use
 252         TUNNELOPEN,             // Active tunnel
 253         TUNNELDIE,              // Currently closing
 254         TUNNELOPENING,          // Busy opening
 255         TUNNELUNDEF,            // Undefined
 256 };
 257
 258 enum
 259 {
 260         RADIUSNULL,             // Not in use
 261         RADIUSCHAP,             // sending CHAP down PPP
 262         RADIUSAUTH,             // sending auth to RADIUS server
 263         RADIUSIPCP,             // sending IPCP to end user
 264         RADIUSSTART,            // sending start accounting to RADIUS server
 265         RADIUSSTOP,             // sending stop accounting to RADIUS server
 266         RADIUSWAIT,             // waiting timeout before available, in case delayed replies
 267         RADIUSDEAD,             // errored while talking to radius server.
 268 };
 269
 270 struct Tstats
 271 {
 272     time_t              start_time;
 273     time_t              last_reset;
 274
 275     unsigned long       tap_rx_packets;
 276     unsigned long       tap_tx_packets;
 277     unsigned long       tap_rx_bytes;
 278     unsigned long       tap_tx_bytes;
 279     unsigned long       tap_rx_errors;
 280     unsigned long       tap_tx_errors;
 281
 282     unsigned long       tunnel_rx_packets;
 283     unsigned long       tunnel_tx_packets;
 284     unsigned long       tunnel_rx_bytes;
 285     unsigned long       tunnel_tx_bytes;
 286     unsigned long       tunnel_rx_errors;
 287     unsigned long       tunnel_tx_errors;
 288
 289     unsigned long       tunnel_retries;
 290     unsigned long       radius_retries;
 291
 292     unsigned long       arp_errors;
 293     unsigned long       arp_replies;
 294     unsigned long       arp_discarded;
 295     unsigned long       arp_sent;
 296     unsigned long       arp_recv;
 297
 298     unsigned long       packets_snooped;
 299
 300     unsigned long       tunnel_created;
 301     unsigned long       session_created;
 302     unsigned long       tunnel_timeout;
 303     unsigned long       session_timeout;
 304     unsigned long       radius_timeout;
 305     unsigned long       radius_overflow;
 306     unsigned long       tunnel_overflow;
 307     unsigned long       session_overflow;
 308
 309     unsigned long       ip_allocated;
 310     unsigned long       ip_freed;
 311
 312     unsigned long       c_forwarded;
 313     unsigned long       recv_forward;
 314 #ifdef STAT_CALLS
 315     unsigned long       call_processtap;
 316     unsigned long       call_processarp;
 317     unsigned long       call_processipout;
 318     unsigned long       call_processudp;
 319     unsigned long       call_sessionbyip;
 320     unsigned long       call_sessionbyuser;
 321     unsigned long       call_sendarp;
 322     unsigned long       call_sendipcp;
 323     unsigned long       call_tunnelsend;
 324     unsigned long       call_sessionkill;
 325     unsigned long       call_sessionshutdown;
 326     unsigned long       call_tunnelkill;
 327     unsigned long       call_tunnelshutdown;
 328     unsigned long       call_assign_ip_address;
 329     unsigned long       call_free_ip_address;
 330     unsigned long       call_dump_acct_info;
 331     unsigned long       call_sessionsetup;
 332     unsigned long       call_processpap;
 333     unsigned long       call_processchap;
 334     unsigned long       call_processlcp;
 335     unsigned long       call_processipcp;
 336     unsigned long       call_processipin;
 337     unsigned long       call_processccp;
 338     unsigned long       call_sendchap;
 339     unsigned long       call_processrad;
 340     unsigned long       call_radiussend;
 341     unsigned long       call_radiusretry;
 342 #endif
 343 };
 344
 345 #ifdef STATISTICS
 346 #define STAT(x)         _statistics->x++
 347 #define INC_STAT(x,y)   _statistics->x += y
 348 #define GET_STAT(x)     _statistics->x
 349 #define SET_STAT(x, y)  _statistics->x = y
 350 #else
 351 #define STAT(x)
 352 #define INC_STAT(x,y)
 353 #define GET_STAT(x)     0
 354 #define SET_STAT(x, y)
 355 #endif
 356
 357 struct configt
 358 {
 359         int             debug;                          // debugging level
 360         time_t          start_time;                     // time when l2tpns was started
 361         char            bandwidth[256];                 // current bandwidth
 362         clockt          current_time;
 363
 364         char            config_file[128];
 365         int             reload_config;                  // flag to re-read config (set by cli)
 366         int             cleanup_interval;               // interval between regular cleanups (in seconds)
 367         int             multi_read_count;               // amount of packets to read per fd in processing loop
 368
 369         char            tapdevice[10];                  // tap device name
 370         char            log_filename[128];
 371         char            l2tpsecret[64];
 372
 373         char            radiussecret[64];
 374         int             radius_accounting;
 375         ipt             radiusserver[MAXRADSERVER];     // radius servers
 376         u8              numradiusservers;               // radius server count
 377         short           num_radfds;                     // Number of radius filehandles allocated
 378
 379         ipt             default_dns1, default_dns2;
 380
 381         unsigned long   rl_rate;
 382         int             save_state;
 383         char            accounting_dir[128];
 384         ipt             bind_address;
 385         int             send_garp;                      // Set to true to garp for vip address on startup
 386
 387         int             target_uid;
 388         int             dump_speed;
 389         char            plugins[64][MAXPLUGINS];
 390         char            old_plugins[64][MAXPLUGINS];
 391
 392         int             next_tbf;                       // Next HTB id available to use
 393         int             scheduler_fifo;                 // If 1, will force scheduler to use SCHED_FIFO.
 394                                                         // Don't use this unless you have a dual processor machine!
 395         int             icmp_rate;                      // Max number of ICMP unreachable per second to send
 396
 397         u32     cluster_address;                // Multicast address of cluster.
 398                                                         // Send to this address to have everyone hear.
 399         char            cluster_interface[64];          // Which interface to listen for multicast on.
 400         int             cluster_iam_master;             // Are we the cluster master???
 401         int             cluster_iam_uptodate;           // Set if we've got a full set of state from the master.
 402         u32     cluster_master_address;         // The network address of the cluster master.
 403                                                         // Zero if i am the cluster master.
 404         int             cluster_seq_number;             // Sequence number of the next heartbeat we'll send out
 405                                                         // (or the seq number we're next expecting if we're a slave).
 406         int             cluster_undefined_sessions;     // How many sessions we're yet to receive from the master.
 407         int             cluster_undefined_tunnels;      // How many tunnels we're yet to receive from the master.
 408         int             cluster_highest_sessionid;
 409         int             cluster_highest_tunnelid;
 410         clockt          cluster_last_hb;                // Last time we saw a heartbeat from the master.
 411         int             cluster_num_changes;            // Number of changes queued.
 412
 413 #ifdef BGP
 414         u16             as_number;
 415         char            bgp_peer[2][64];
 416         u16             bgp_peer_as[2];
 417 #endif
 418 };
 419
 420 struct config_descriptt
 421 {
 422         char *key;
 423         int offset;
 424         int size;
 425         enum { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP } type;
 426 };
 427
 428 // arp.c
 429 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
 430
 431
 432 // ppp.c
 433 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 434 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 435 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 436 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 437 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
 438 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 439 void sendchap(tunnelidt t, sessionidt s);
 440 u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
 441 u8 *findppp(u8 * b, u8 mtype);
 442 void initlcp(tunnelidt t, sessionidt s);
 443 void dumplcp(u8 *p, int l);
 444
 445
 446 // radius.c
 447 void initrad(void);
 448 void radiussend(u16 r, u8 state);
 449 void processrad(u8 *buf, int len, char socket_index);
 450 void radiusretry(u16 r);
 451 u16 radiusnew(sessionidt s);
 452 void radiusclear(u16 r, sessionidt s);
 453
 454 // throttle.c
 455 int throttle_session(sessionidt s, int throttle);
 456
 457
 458 // rl.c
 459 void init_rl();
 460 u16 rl_create_tbf();
 461 u16 rl_get_tbf();
 462 void rl_done_tbf(u16 t);
 463 void rl_destroy_tbf(u16 t);
 464
 465
 466 // l2tpns.c
 467 clockt now(void);
 468 clockt backoff(u8 try);
 469 void routeset(sessionidt, ipt ip, ipt mask, ipt gw, u8 add);
 470 void inittap(void);
 471 void initudp(void);
 472 void initdata(void);
 473 void initippool();
 474 sessionidt sessionbyip(ipt ip);
 475 sessionidt sessionbyuser(char *username);
 476 void sessionshutdown(sessionidt s, char *reason);
 477 void sessionsendarp(sessionidt s);
 478 void send_garp(ipt ip);
 479 void sessionkill(sessionidt s, char *reason);
 480 void control16(controlt * c, u16 avp, u16 val, u8 m);
 481 void control32(controlt * c, u16 avp, u32 val, u8 m);
 482 void controls(controlt * c, u16 avp, char *val, u8 m);
 483 void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m);
 484 controlt *controlnew(u16 mtype);
 485 void controlnull(tunnelidt t);
 486 void controladd(controlt * c, tunnelidt t, sessionidt s);
 487 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
 488 void tunnelkill(tunnelidt t, char *reason);
 489 void tunnelshutdown(tunnelidt t, char *reason);
 490 void sendipcp(tunnelidt t, sessionidt s);
 491 void processipout(u8 * buf, int len);
 492 void processarp(u8 * buf, int len);
 493 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
 494 void processtap(u8 * buf, int len);
 495 void processcontrol(u8 * buf, int len, struct sockaddr_in *addr);
 496 int assign_ip_address(sessionidt s);
 497 void free_ip_address(sessionidt s);
 498 void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port);
 499 void dump_acct_info();
 500 void mainloop(void);
 501 int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc);
 502 int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc);
 503 int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc);
 504
 505 #define log _log
 506 #ifndef log_hex
 507 #define log_hex(a,b,c,d) do{if (a <= config->debug) _log_hex(a,0,0,0,b,c,d);}while (0)
 508 #endif
 509 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 5, 6)));
 510 void _log_hex(int level, ipt address, sessionidt s, tunnelidt t, const char *title, const char *data, int maxsize);
 511 void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response);
 512 int sessionsetup(tunnelidt t, sessionidt s);
 513 int cluster_send_session(int s);
 514 int cluster_send_tunnel(int t);
 515 int cluster_send_goodbye();
 516 void init_cli();
 517 void cli_do_file(FILE *fh);
 518 void cli_do(int sockfd);
 519 #ifdef RINGBUFFER
 520 void ringbuffer_dump(FILE *stream);
 521 #endif
 522 void initplugins(void);
 523 int run_plugins(int plugin_type, void *data);
 524 void add_plugin(char *plugin_name);
 525 void remove_plugin(char *plugin_name);
 526 void plugins_done(void);
 527 void tunnelclear(tunnelidt t);
 528 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
 529 void fix_address_pool(int sid);
 530 void rebuild_address_pool(void);
 531 void send_ipin(sessionidt s, u8 * buf, int len);
 532 int throttle_session(sessionidt s, int throttle);
 533 int load_session(sessionidt, sessiont *);
 534 void become_master(void);       // We're the master; kick off any required master initializations.
 535 extern tunnelt *tunnel;
 536 extern sessiont *session;
 537 extern sessioncountt *sess_count;
 538 extern ippoolt *ip_address_pool;
 539 #define sessionfree (session[0].next)
 540
 541 #define log_backtrace(count, max) \
 542 if (count++ < max) { \
 543         void *array[20]; \
 544         char **strings; \
 545         int size, i; \
 546         log(0, 0, 0, t, "Backtrace follows"); \
 547         size = backtrace(array, 10); \
 548         strings = backtrace_symbols(array, size); \
 549         if (strings) for (i = 0; i < size; i++) \
 550         { \
 551                 log(0, 0, 0, t, "%s\n", strings[i]); \
 552         } \
 553         free(strings); \
 554 }
 555
 556
 557 extern struct configt *config;
 558 extern time_t basetime;         // Time when this process started.
 559 extern time_t time_now;         // Seconds since EPOCH.
 560 extern u32 last_sid;
 561 extern struct Tstats *_statistics;
 562 extern ipt my_address;
 563 extern int tun_write(u8 *data, int size);
 564 #endif /* __L2TPNS_H__ */