l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.6 2004/05/24 04:33:35 fred_nerk Exp $
   3
   4 #include <netinet/in.h>
   5 #include <stdio.h>
   6 #include <execinfo.h>
   7 #include "config.h"
   8
   9 #define VERSION "1.2.0"
  10
  11 // Limits
  12 #define MAXTUNNEL       500             // could be up to 65535
  13 #define MAXSESSION      50000           // could be up to 65535
  14 #define RADIUS_SHIFT    5
  15 #define RADIUS_MASK     ((unsigned short)(((unsigned short)~0) >> (16 - RADIUS_SHIFT)))
  16 #define MAXRADIUS       ((2 << (RADIUS_SHIFT - 1)) * 255)
  17
  18 #define MAXCONTROL      1000            // max length control message we ever send...
  19 #define MAXETHER        (1500+18)       // max packet we try sending to tap
  20 #define MAXTEL          96              // telephone number
  21 #define MAXPLUGINS      20              // maximum number of plugins to load
  22 #define MAXRADSERVER    10              // max radius servers
  23 #define MAXROUTE        10              // max static routes per session
  24 #define MAXIPPOOL       131072          // max number of ip addresses in pool
  25 #define RINGBUFFER_SIZE 10000           // Number of ringbuffer entries to allocate
  26 #define MAX_LOG_LENGTH  512             // Maximum size of log message
  27 #define ECHO_TIMEOUT    60              // Time between last packet sent and LCP ECHO generation
  28 #define IDLE_TIMEOUT    240             // Time between last packet sent and LCP ECHO generation
  29
  30 // Constants
  31 #define STATISTICS
  32 #define STAT_CALLS
  33 #define RINGBUFFER
  34 #define TAPDEVICE       "/dev/net/tun"
  35 #define UDP             17
  36 #define HOMEDIR         "/home/l2tpns/"                 // Base dir for data
  37 #define STATEFILE       "/tmp/l2tpns.dump"              // State dump file
  38 #define NOSTATEFILE     "/tmp/l2tpns.no_state_reload"   // If exists, state will not be reloaded
  39 #define CONFIGFILE      ETCDIR "/l2tpns.cfg"            // Configuration file
  40 #define CLIUSERS        ETCDIR "/l2tpns.users"          // CLI Users file
  41 #define IPPOOLFILE      ETCDIR "/l2tpns.ip_pool"        // Address pool configuration
  42 #ifndef LIBDIR
  43 #define LIBDIR          "/usr/lib/l2tpns"
  44 #endif
  45 #define ACCT_TIME       3000            // 5 minute accounting interval
  46 #define L2TPPORT        1701            // L2TP port
  47 #define RADPORT         1645            // old radius port...
  48 #define RADAPORT        1646            // old radius accounting port
  49 #define PKTARP          0x0806          // ARP packet type
  50 #define PKTIP           0x0800          // IP packet type
  51 #define PSEUDOMAC       0x0200          // pseudo MAC prefix (local significant MAC)
  52 #define PPPPAP          0xC023
  53 #define PPPCHAP         0xC223
  54 #define PPPLCP          0xC021
  55 #define PPPIPCP         0x8021
  56 #define PPPCCP          0x80FD
  57 #define PPPIP           0x0021
  58 #define PPPMP           0x003D
  59 #define MIN_IP_SIZE     0x20
  60 enum
  61 {
  62         ConfigReq = 1,
  63         ConfigAck,
  64         ConfigNak,
  65         ConfigRej,
  66         TerminateReq,
  67         TerminateAck,
  68         CodeRej,
  69         ProtocolRej,
  70         EchoReq,
  71         EchoReply,
  72         DiscardRequest
  73 };
  74
  75 // Types
  76 typedef unsigned short u16;
  77 typedef unsigned int u32;
  78 typedef unsigned char u8;
  79 typedef u32 ipt;
  80 typedef u16 portt;
  81 typedef u16 sessionidt;
  82 typedef u16 tunnelidt;
  83 typedef u32 clockt;
  84 typedef u8 hasht[16];
  85
  86 // dump header: update number if internal format changes
  87 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
  88
  89 // structures
  90 typedef struct routes           // route
  91 {
  92         ipt ip;
  93         ipt mask;
  94 }
  95 routet;
  96
  97 typedef struct controls         // control message
  98 {
  99         struct controls *next;  // next in queue
 100         u16 length;             // length
 101         u8 buf[MAXCONTROL];
 102 }
 103 controlt;
 104
 105 typedef struct stbft
 106 {
 107     char handle[10];
 108     char in_use;
 109 } tbft;
 110
 111
 112 // 336 bytes per session
 113 typedef struct sessions
 114 {
 115         sessionidt next;                // next session in linked list
 116         sessionidt far;                 // far end session ID
 117         tunnelidt tunnel;               // tunnel ID
 118         ipt ip;                         // IP of session set by RADIUS response
 119         int ip_pool_index;              // index to IP pool
 120         unsigned long sid;              // session id for hsddb
 121         u16 nr;                         // next receive
 122         u16 ns;                         // next send
 123         u32 magic;                      // ppp magic number
 124         u32 cin, cout;                  // byte counts
 125         u32 pin, pout;                  // packet counts
 126         u32 total_cin;                  // This counter is never reset while a session is open
 127         u32 total_cout;                 // This counter is never reset while a session is open
 128         u32 id;                         // session id
 129         clockt opened;                  // when started
 130         clockt die;                     // being closed, when to finally free
 131         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 132         ipt dns1, dns2;                 // DNS servers
 133         routet route[MAXROUTE];         // static routes
 134         u16 radius;                     // which radius session is being used (0 for not waiting on authentication)
 135         u8 flags;                       // various bit flags
 136         u8 snoop;                       // are we snooping this session?
 137         u8 throttle;                    // is this session throttled?
 138         u8 walled_garden;               // is this session gardened?
 139         u16 mru;                        // maximum receive unit
 140         u16 tbf;                        // filter bucket for throttling
 141         char random_vector[MAXTEL];
 142         int random_vector_length;
 143         char user[129];                 // user (needed in seesion for radius stop messages)
 144         char called[MAXTEL];            // called number
 145         char calling[MAXTEL];           // calling number
 146         unsigned long tx_connect_speed;
 147         unsigned long rx_connect_speed;
 148 }
 149 sessiont;
 150
 151 #define SESSIONPFC      1            // PFC negotiated flags
 152 #define SESSIONACFC     2           // ACFC negotiated flags
 153
 154 // 168 bytes per tunnel
 155 typedef struct tunnels
 156 {
 157         tunnelidt far;          // far end tunnel ID
 158         ipt ip;                 // Ip for far end
 159         portt port;             // port for far end
 160         u16 window;             // Rx window
 161         u16 nr;                 // next receive
 162         u16 ns;                 // next send
 163         int state;              // current state (tunnelstate enum)
 164         clockt last;            // when last control message sent (used for resend timeout)
 165         clockt retry;           // when to try resenting pending control
 166         clockt die;             // being closed, when to finally free
 167         clockt lastrec;         // when the last control message was received
 168         char hostname[128];     // tunnel hostname
 169         char vendor[128];       // LAC vendor
 170         u8 try;                 // number of retrys on a control message
 171         u16 controlc;           // outstaind messages in queue
 172         controlt *controls;     // oldest message
 173         controlt *controle;     // newest message
 174 }
 175 tunnelt;
 176
 177 // 180 bytes per radius session
 178 typedef struct radiuss          // outstanding RADIUS requests
 179 {
 180         sessionidt session;     // which session this applies to
 181         hasht auth;             // request authenticator
 182         clockt retry;           // when to try next
 183         char calling[MAXTEL];   // calling number
 184         char pass[129];         // password
 185         u8 id;                  // ID for PPP response
 186         u8 try;                 // which try we are on
 187         u8 state;               // state of radius requests
 188         u8 chap;                // set if CHAP used (is CHAP identifier)
 189 }
 190 radiust;
 191
 192 typedef struct
 193 {
 194         ipt             address;
 195         char            assigned;       // 1 if assigned, 0 if free
 196         sessionidt      session;
 197         clockt          last;           // last used
 198         char            user[129];      // user (try to have ip addresses persistent)
 199 }
 200 ippoolt;
 201
 202 #ifdef RINGBUFFER
 203 struct Tringbuffer
 204 {
 205         struct {
 206                 char level;
 207                 sessionidt session;
 208                 tunnelidt tunnel;
 209                 ipt address;
 210                 char message[MAX_LOG_LENGTH];
 211         } buffer[RINGBUFFER_SIZE];
 212         int head;
 213         int tail;
 214 };
 215 #endif
 216
 217 /*
 218  * Possible tunnel states
 219  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 220  */
 221 enum
 222 {
 223         TUNNELFREE,             // Not in use
 224         TUNNELOPEN,             // Active tunnel
 225         TUNNELDIE,              // Currently closing
 226         TUNNELOPENING           // Busy opening
 227 };
 228
 229 enum
 230 {
 231         RADIUSNULL,             // Not in use
 232         RADIUSCHAP,             // sending CHAP down PPP
 233         RADIUSAUTH,             // sending auth to RADIUS server
 234         RADIUSIPCP,             // sending IPCP to end user
 235         RADIUSSTART,            // sending start accounting to RADIUS server
 236         RADIUSSTOP,             // sending stop accounting to RADIUS server
 237         RADIUSWAIT              // waiting timeout before available, in case delayed replies
 238 };
 239
 240 struct Tstats
 241 {
 242     time_t              start_time;
 243     time_t              last_reset;
 244
 245     unsigned long       tap_rx_packets;
 246     unsigned long       tap_tx_packets;
 247     unsigned long       tap_rx_bytes;
 248     unsigned long       tap_tx_bytes;
 249     unsigned long       tap_rx_errors;
 250     unsigned long       tap_tx_errors;
 251
 252     unsigned long       tunnel_rx_packets;
 253     unsigned long       tunnel_tx_packets;
 254     unsigned long       tunnel_rx_bytes;
 255     unsigned long       tunnel_tx_bytes;
 256     unsigned long       tunnel_rx_errors;
 257     unsigned long       tunnel_tx_errors;
 258
 259     unsigned long       tunnel_retries;
 260     unsigned long       radius_retries;
 261
 262     unsigned long       arp_errors;
 263     unsigned long       arp_replies;
 264     unsigned long       arp_discarded;
 265     unsigned long       arp_sent;
 266     unsigned long       arp_recv;
 267
 268     unsigned long       packets_snooped;
 269
 270     unsigned long       tunnel_created;
 271     unsigned long       session_created;
 272     unsigned long       tunnel_timeout;
 273     unsigned long       session_timeout;
 274     unsigned long       radius_timeout;
 275     unsigned long       radius_overflow;
 276     unsigned long       tunnel_overflow;
 277     unsigned long       session_overflow;
 278
 279     unsigned long       ip_allocated;
 280     unsigned long       ip_freed;
 281 #ifdef STAT_CALLS
 282     unsigned long       call_processtap;
 283     unsigned long       call_processarp;
 284     unsigned long       call_processipout;
 285     unsigned long       call_processudp;
 286     unsigned long       call_sessionbyip;
 287     unsigned long       call_sessionbyuser;
 288     unsigned long       call_sendarp;
 289     unsigned long       call_sendipcp;
 290     unsigned long       call_tunnelsend;
 291     unsigned long       call_sessionkill;
 292     unsigned long       call_sessionshutdown;
 293     unsigned long       call_tunnelkill;
 294     unsigned long       call_tunnelshutdown;
 295     unsigned long       call_assign_ip_address;
 296     unsigned long       call_free_ip_address;
 297     unsigned long       call_dump_acct_info;
 298     unsigned long       call_sessionsetup;
 299     unsigned long       call_processpap;
 300     unsigned long       call_processchap;
 301     unsigned long       call_processlcp;
 302     unsigned long       call_processipcp;
 303     unsigned long       call_processipin;
 304     unsigned long       call_processccp;
 305     unsigned long       call_sendchap;
 306     unsigned long       call_processrad;
 307     unsigned long       call_radiussend;
 308     unsigned long       call_radiusretry;
 309 #endif
 310 };
 311
 312 #ifdef STATISTICS
 313 #define STAT(x)         _statistics->x++
 314 #define INC_STAT(x,y)   _statistics->x += y
 315 #define GET_STAT(x)     _statistics->x
 316 #define SET_STAT(x, y)  _statistics->x = y
 317 #else
 318 #define STAT(x)
 319 #define INC_STAT(x,y)
 320 #define GET_STAT(x)     0
 321 #define SET_STAT(x, y)
 322 #endif
 323
 324 struct configt
 325 {
 326         int             debug;                          // debugging level
 327         time_t          start_time;                     // time when l2tpns was started
 328         char            bandwidth[256];                 // current bandwidth
 329
 330         char            config_file[128];
 331         int             reload_config;                  // flag to re-read config (set by cli)
 332         int             cleanup_interval;               // interval between regular cleanups (in seconds)
 333         int             multi_read_count;               // amount of packets to read per fd in processing loop
 334
 335         char            tapdevice[10];                  // tap device name
 336         char            log_filename[128];
 337         char            l2tpsecret[64];
 338
 339         char            radiussecret[64];
 340         int             radius_accounting;
 341         ipt             radiusserver[MAXRADSERVER];     // radius servers
 342         u8              numradiusservers;               // radius server count
 343         short           num_radfds;                     // Number of radius filehandles allocated
 344
 345         ipt             default_dns1, default_dns2;
 346
 347         ipt             snoop_destination_host;
 348         u16             snoop_destination_port;
 349
 350         unsigned long   rl_rate;
 351         int             save_state;
 352         uint32_t        cluster_address;
 353         int             ignore_cluster_updates;
 354         char            accounting_dir[128];
 355         ipt             bind_address;
 356         int             target_uid;
 357         int             dump_speed;
 358         char            plugins[64][MAXPLUGINS];
 359         char            old_plugins[64][MAXPLUGINS];
 360
 361         int             next_tbf;                       // Next HTB id available to use
 362 };
 363
 364 struct config_descriptt
 365 {
 366         char *key;
 367         int offset;
 368         int size;
 369         enum { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP } type;
 370 };
 371
 372 // arp.c
 373 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
 374
 375
 376 // ppp.c
 377 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 378 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 379 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 380 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 381 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
 382 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 383 void sendchap(tunnelidt t, sessionidt s);
 384 u8 *makeppp(u8 * b, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
 385 u8 *findppp(u8 * b, u8 mtype);
 386 void initlcp(tunnelidt t, sessionidt s);
 387 void dumplcp(char *p, int l);
 388
 389
 390 // radius.c
 391 void initrad(void);
 392 void radiussend(u16 r, u8 state);
 393 void processrad(u8 *buf, int len, char socket_index);
 394 void radiusretry(u16 r);
 395 u16 radiusnew(sessionidt s);
 396 void radiusclear(u16 r, sessionidt s);
 397
 398 // throttle.c
 399 int throttle_session(sessionidt s, int throttle);
 400
 401
 402 // rl.c
 403 void init_rl();
 404 u16 rl_create_tbf();
 405 u16 rl_get_tbf();
 406 void rl_done_tbf(u16 t);
 407 void rl_destroy_tbf(u16 t);
 408
 409
 410 // l2tpns.c
 411 clockt now(void);
 412 clockt backoff(u8 try);
 413 void routeset(ipt ip, ipt mask, ipt gw, u8 add);
 414 void inittap(void);
 415 void initudp(void);
 416 void initdata(void);
 417 void initippool();
 418 sessionidt sessionbyip(ipt ip);
 419 sessionidt sessionbyuser(char *username);
 420 void sessionshutdown(sessionidt s, char *reason);
 421 void sessionsendarp(sessionidt s);
 422 void send_garp(ipt ip);
 423 void sessionkill(sessionidt s, char *reason);
 424 void control16(controlt * c, u16 avp, u16 val, u8 m);
 425 void control32(controlt * c, u16 avp, u32 val, u8 m);
 426 void controls(controlt * c, u16 avp, char *val, u8 m);
 427 void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m);
 428 controlt *controlnew(u16 mtype);
 429 void controlnull(tunnelidt t);
 430 void controladd(controlt * c, tunnelidt t, sessionidt s);
 431 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
 432 void tunnelkill(tunnelidt t, char *reason);
 433 void tunnelshutdown(tunnelidt t, char *reason);
 434 void sendipcp(tunnelidt t, sessionidt s);
 435 void processipout(u8 * buf, int len);
 436 void processarp(u8 * buf, int len);
 437 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
 438 void processtap(u8 * buf, int len);
 439 void processcontrol(u8 * buf, int len, struct sockaddr_in *addr);
 440 int assign_ip_address(sessionidt s);
 441 void free_ip_address(sessionidt s);
 442 void snoop_send_packet(char *packet, u16 size);
 443 void dump_acct_info();
 444 void mainloop(void);
 445 #define log _log
 446 #ifndef log_hex
 447 #define log_hex(a,b,c,d) do{if (a <= config->debug) _log_hex(a,0,0,0,b,c,d);}while (0)
 448 #endif
 449 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 5, 6)));
 450 void _log_hex(int level, ipt address, sessionidt s, tunnelidt t, const char *title, const char *data, int maxsize);
 451 void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response);
 452 int sessionsetup(tunnelidt t, sessionidt s, u8 routes);
 453 int cluster_send_session(int s);
 454 int cluster_send_tunnel(int t);
 455 int cluster_send_goodbye();
 456 void init_cli();
 457 void cli_do_file(FILE *fh);
 458 void cli_do(int sockfd);
 459 #ifdef RINGBUFFER
 460 void ringbuffer_dump(FILE *stream);
 461 #endif
 462 void initplugins();
 463 int run_plugins(int plugin_type, void *data);
 464 void add_plugin(char *plugin_name);
 465 void remove_plugin(char *plugin_name);
 466 void tunnelclear(tunnelidt t);
 467 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
 468
 469 extern tunnelt *tunnel;
 470 extern sessiont *session;
 471 #define sessionfree (session[0].next)
 472
 473 #define log_backtrace(count, max) \
 474 if (count++ < max) { \
 475         void *array[20]; \
 476         char **strings; \
 477         int size, i; \
 478         log(0, 0, 0, t, "Backtrace follows"); \
 479         size = backtrace(array, 10); \
 480         strings = backtrace_symbols(array, size); \
 481         if (strings) for (i = 0; i < size; i++) \
 482         { \
 483                 log(0, 0, 0, t, "%s\n", strings[i]); \
 484         } \
 485         free(strings); \
 486 }
 487