l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.5 2004-05-24 04:24:06 fred_nerk Exp $
   3
   4 #include <netinet/in.h>
   5 #include <stdio.h>
   6 #include <config.h>
   7
   8 #define VERSION "1.2.0"
   9
  10 // Limits
  11 #define MAXTUNNEL       500             // could be up to 65535
  12 #define MAXSESSION      50000           // could be up to 65535
  13 #define RADIUS_SHIFT    5
  14 #define RADIUS_MASK     ((unsigned short)(((unsigned short)~0) >> (16 - RADIUS_SHIFT)))
  15 #define MAXRADIUS       ((2 << (RADIUS_SHIFT - 1)) * 255)
  16
  17 #define MAXCONTROL      1000            // max length control message we ever send...
  18 #define MAXETHER        (1500+18)       // max packet we try sending to tap
  19 #define MAXTEL          96              // telephone number
  20 #define MAXPLUGINS      20              // maximum number of plugins to load
  21 #define MAXRADSERVER    10              // max radius servers
  22 #define MAXROUTE        10              // max static routes per session
  23 #define MAXIPPOOL       131072          // max number of ip addresses in pool
  24 #define RINGBUFFER_SIZE 10000           // Number of ringbuffer entries to allocate
  25 #define MAX_LOG_LENGTH  512             // Maximum size of log message
  26 #define ECHO_TIMEOUT    60              // Time between last packet sent and LCP ECHO generation
  27 #define IDLE_TIMEOUT    240             // Time between last packet sent and LCP ECHO generation
  28
  29 // Constants
  30 #define STATISTICS
  31 #define STAT_CALLS
  32 #define RINGBUFFER
  33 #define TAPDEVICE       "/dev/net/tun"
  34 #define UDP             17
  35 #define HOMEDIR         "/home/l2tpns/"                 // Base dir for data
  36 #define STATEFILE       "/tmp/l2tpns.dump"              // State dump file
  37 #define NOSTATEFILE     "/tmp/l2tpns.no_state_reload"   // If exists, state will not be reloaded
  38 #define CONFIGFILE      ETCDIR "/l2tpns.cfg"            // Configuration file
  39 #define CLIUSERS        ETCDIR "/l2tpns.users"          // CLI Users file
  40 #define IPPOOLFILE      ETCDIR "/l2tpns.ip_pool"        // Address pool configuration
  41 #ifndef LIBDIR
  42 #define LIBDIR          "/usr/lib/l2tpns"
  43 #endif
  44 #define ACCT_TIME       3000            // 5 minute accounting interval
  45 #define L2TPPORT        1701            // L2TP port
  46 #define RADPORT         1645            // old radius port...
  47 #define RADAPORT        1646            // old radius accounting port
  48 #define PKTARP          0x0806          // ARP packet type
  49 #define PKTIP           0x0800          // IP packet type
  50 #define PSEUDOMAC       0x0200          // pseudo MAC prefix (local significant MAC)
  51 #define PPPPAP          0xC023
  52 #define PPPCHAP         0xC223
  53 #define PPPLCP          0xC021
  54 #define PPPIPCP         0x8021
  55 #define PPPCCP          0x80FD
  56 #define PPPIP           0x0021
  57 #define PPPMP           0x003D
  58 #define MIN_IP_SIZE     0x20
  59 enum
  60 {
  61         ConfigReq = 1,
  62         ConfigAck,
  63         ConfigNak,
  64         ConfigRej,
  65         TerminateReq,
  66         TerminateAck,
  67         CodeRej,
  68         ProtocolRej,
  69         EchoReq,
  70         EchoReply,
  71         DiscardRequest
  72 };
  73
  74 // Types
  75 typedef unsigned short u16;
  76 typedef unsigned int u32;
  77 typedef unsigned char u8;
  78 typedef u32 ipt;
  79 typedef u16 portt;
  80 typedef u16 sessionidt;
  81 typedef u16 tunnelidt;
  82 typedef u32 clockt;
  83 typedef u8 hasht[16];
  84
  85 // dump header: update number if internal format changes
  86 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
  87
  88 // structures
  89 typedef struct routes           // route
  90 {
  91         ipt ip;
  92         ipt mask;
  93 }
  94 routet;
  95
  96 typedef struct controls         // control message
  97 {
  98         struct controls *next;  // next in queue
  99         u16 length;             // length
 100         u8 buf[MAXCONTROL];
 101 }
 102 controlt;
 103
 104 typedef struct stbft
 105 {
 106     char handle[10];
 107     char in_use;
 108 } tbft;
 109
 110
 111 // 336 bytes per session
 112 typedef struct sessions
 113 {
 114         sessionidt next;                // next session in linked list
 115         sessionidt far;                 // far end session ID
 116         tunnelidt tunnel;               // tunnel ID
 117         ipt ip;                         // IP of session set by RADIUS response
 118         int ip_pool_index;              // index to IP pool
 119         unsigned long sid;              // session id for hsddb
 120         u16 nr;                         // next receive
 121         u16 ns;                         // next send
 122         u32 magic;                      // ppp magic number
 123         u32 cin, cout;                  // byte counts
 124         u32 pin, pout;                  // packet counts
 125         u32 total_cin;                  // This counter is never reset while a session is open
 126         u32 total_cout;                 // This counter is never reset while a session is open
 127         u32 id;                         // session id
 128         clockt opened;                  // when started
 129         clockt die;                     // being closed, when to finally free
 130         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 131         ipt dns1, dns2;                 // DNS servers
 132         routet route[MAXROUTE];         // static routes
 133         u16 radius;                     // which radius session is being used (0 for not waiting on authentication)
 134         u8 flags;                       // various bit flags
 135         u8 snoop;                       // are we snooping this session?
 136         u8 throttle;                    // is this session throttled?
 137         u8 walled_garden;               // is this session gardened?
 138         u16 mru;                        // maximum receive unit
 139         u16 tbf;                        // filter bucket for throttling
 140         char random_vector[MAXTEL];
 141         int random_vector_length;
 142         char user[129];                 // user (needed in seesion for radius stop messages)
 143         char called[MAXTEL];            // called number
 144         char calling[MAXTEL];           // calling number
 145         unsigned long tx_connect_speed;
 146         unsigned long rx_connect_speed;
 147 }
 148 sessiont;
 149
 150 #define SESSIONPFC      1            // PFC negotiated flags
 151 #define SESSIONACFC     2           // ACFC negotiated flags
 152
 153 // 168 bytes per tunnel
 154 typedef struct tunnels
 155 {
 156         tunnelidt far;          // far end tunnel ID
 157         ipt ip;                 // Ip for far end
 158         portt port;             // port for far end
 159         u16 window;             // Rx window
 160         u16 nr;                 // next receive
 161         u16 ns;                 // next send
 162         int state;              // current state (tunnelstate enum)
 163         clockt last;            // when last control message sent (used for resend timeout)
 164         clockt retry;           // when to try resenting pending control
 165         clockt die;             // being closed, when to finally free
 166         clockt lastrec;         // when the last control message was received
 167         char hostname[128];     // tunnel hostname
 168         char vendor[128];       // LAC vendor
 169         u8 try;                 // number of retrys on a control message
 170         u16 controlc;           // outstaind messages in queue
 171         controlt *controls;     // oldest message
 172         controlt *controle;     // newest message
 173 }
 174 tunnelt;
 175
 176 // 180 bytes per radius session
 177 typedef struct radiuss          // outstanding RADIUS requests
 178 {
 179         sessionidt session;     // which session this applies to
 180         hasht auth;             // request authenticator
 181         clockt retry;           // when to try next
 182         char calling[MAXTEL];   // calling number
 183         char pass[129];         // password
 184         u8 id;                  // ID for PPP response
 185         u8 try;                 // which try we are on
 186         u8 state;               // state of radius requests
 187         u8 chap;                // set if CHAP used (is CHAP identifier)
 188 }
 189 radiust;
 190
 191 typedef struct
 192 {
 193         ipt             address;
 194         char            assigned;       // 1 if assigned, 0 if free
 195         sessionidt      session;
 196         clockt          last;           // last used
 197         char            user[129];      // user (try to have ip addresses persistent)
 198 }
 199 ippoolt;
 200
 201 #ifdef RINGBUFFER
 202 struct Tringbuffer
 203 {
 204         struct {
 205                 char level;
 206                 sessionidt session;
 207                 tunnelidt tunnel;
 208                 ipt address;
 209                 char message[MAX_LOG_LENGTH];
 210         } buffer[RINGBUFFER_SIZE];
 211         int head;
 212         int tail;
 213 };
 214 #endif
 215
 216 /*
 217  * Possible tunnel states
 218  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 219  */
 220 enum
 221 {
 222         TUNNELFREE,             // Not in use
 223         TUNNELOPEN,             // Active tunnel
 224         TUNNELDIE,              // Currently closing
 225         TUNNELOPENING           // Busy opening
 226 };
 227
 228 enum
 229 {
 230         RADIUSNULL,             // Not in use
 231         RADIUSCHAP,             // sending CHAP down PPP
 232         RADIUSAUTH,             // sending auth to RADIUS server
 233         RADIUSIPCP,             // sending IPCP to end user
 234         RADIUSSTART,            // sending start accounting to RADIUS server
 235         RADIUSSTOP,             // sending stop accounting to RADIUS server
 236         RADIUSWAIT              // waiting timeout before available, in case delayed replies
 237 };
 238
 239 struct Tstats
 240 {
 241     time_t              start_time;
 242     time_t              last_reset;
 243
 244     unsigned long       tap_rx_packets;
 245     unsigned long       tap_tx_packets;
 246     unsigned long       tap_rx_bytes;
 247     unsigned long       tap_tx_bytes;
 248     unsigned long       tap_rx_errors;
 249     unsigned long       tap_tx_errors;
 250
 251     unsigned long       tunnel_rx_packets;
 252     unsigned long       tunnel_tx_packets;
 253     unsigned long       tunnel_rx_bytes;
 254     unsigned long       tunnel_tx_bytes;
 255     unsigned long       tunnel_rx_errors;
 256     unsigned long       tunnel_tx_errors;
 257
 258     unsigned long       tunnel_retries;
 259     unsigned long       radius_retries;
 260
 261     unsigned long       arp_errors;
 262     unsigned long       arp_replies;
 263     unsigned long       arp_discarded;
 264     unsigned long       arp_sent;
 265     unsigned long       arp_recv;
 266
 267     unsigned long       packets_snooped;
 268
 269     unsigned long       tunnel_created;
 270     unsigned long       session_created;
 271     unsigned long       tunnel_timeout;
 272     unsigned long       session_timeout;
 273     unsigned long       radius_timeout;
 274     unsigned long       radius_overflow;
 275     unsigned long       tunnel_overflow;
 276     unsigned long       session_overflow;
 277
 278     unsigned long       ip_allocated;
 279     unsigned long       ip_freed;
 280 #ifdef STAT_CALLS
 281     unsigned long       call_processtap;
 282     unsigned long       call_processarp;
 283     unsigned long       call_processipout;
 284     unsigned long       call_processudp;
 285     unsigned long       call_sessionbyip;
 286     unsigned long       call_sessionbyuser;
 287     unsigned long       call_sendarp;
 288     unsigned long       call_sendipcp;
 289     unsigned long       call_tunnelsend;
 290     unsigned long       call_sessionkill;
 291     unsigned long       call_sessionshutdown;
 292     unsigned long       call_tunnelkill;
 293     unsigned long       call_tunnelshutdown;
 294     unsigned long       call_assign_ip_address;
 295     unsigned long       call_free_ip_address;
 296     unsigned long       call_dump_acct_info;
 297     unsigned long       call_sessionsetup;
 298     unsigned long       call_processpap;
 299     unsigned long       call_processchap;
 300     unsigned long       call_processlcp;
 301     unsigned long       call_processipcp;
 302     unsigned long       call_processipin;
 303     unsigned long       call_processccp;
 304     unsigned long       call_sendchap;
 305     unsigned long       call_processrad;
 306     unsigned long       call_radiussend;
 307     unsigned long       call_radiusretry;
 308 #endif
 309 };
 310
 311 #ifdef STATISTICS
 312 #define STAT(x)         _statistics->x++
 313 #define INC_STAT(x,y)   _statistics->x += y
 314 #define GET_STAT(x)     _statistics->x
 315 #define SET_STAT(x, y)  _statistics->x = y
 316 #else
 317 #define STAT(x)
 318 #define INC_STAT(x,y)
 319 #define GET_STAT(x)     0
 320 #define SET_STAT(x, y)
 321 #endif
 322
 323 struct configt
 324 {
 325         int             debug;                          // debugging level
 326         time_t          start_time;                     // time when l2tpns was started
 327         char            bandwidth[256];                 // current bandwidth
 328
 329         char            config_file[128];
 330         int             reload_config;                  // flag to re-read config (set by cli)
 331         int             cleanup_interval;               // interval between regular cleanups (in seconds)
 332         int             multi_read_count;               // amount of packets to read per fd in processing loop
 333
 334         char            tapdevice[10];                  // tap device name
 335         char            log_filename[128];
 336         char            l2tpsecret[64];
 337
 338         char            radiussecret[64];
 339         int             radius_accounting;
 340         ipt             radiusserver[MAXRADSERVER];     // radius servers
 341         u8              numradiusservers;               // radius server count
 342         short           num_radfds;                     // Number of radius filehandles allocated
 343
 344         ipt             default_dns1, default_dns2;
 345
 346         ipt             snoop_destination_host;
 347         u16             snoop_destination_port;
 348
 349         unsigned long   rl_rate;
 350         int             save_state;
 351         uint32_t        cluster_address;
 352         int             ignore_cluster_updates;
 353         char            accounting_dir[128];
 354         ipt             bind_address;
 355         int             target_uid;
 356         int             dump_speed;
 357         char            plugins[64][MAXPLUGINS];
 358         char            old_plugins[64][MAXPLUGINS];
 359
 360         int             next_tbf;                       // Next HTB id available to use
 361 };
 362
 363 struct config_descriptt
 364 {
 365         char *key;
 366         int offset;
 367         int size;
 368         enum { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP } type;
 369 };
 370
 371 // arp.c
 372 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
 373
 374
 375 // ppp.c
 376 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 377 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 378 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 379 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 380 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
 381 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 382 void sendchap(tunnelidt t, sessionidt s);
 383 u8 *makeppp(u8 * b, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
 384 u8 *findppp(u8 * b, u8 mtype);
 385 void initlcp(tunnelidt t, sessionidt s);
 386 void dumplcp(char *p, int l);
 387
 388
 389 // radius.c
 390 void initrad(void);
 391 void radiussend(u16 r, u8 state);
 392 void processrad(u8 *buf, int len, char socket_index);
 393 void radiusretry(u16 r);
 394 u16 radiusnew(sessionidt s);
 395 void radiusclear(u16 r, sessionidt s);
 396
 397 // throttle.c
 398 int throttle_session(sessionidt s, int throttle);
 399
 400
 401 // rl.c
 402 void init_rl();
 403 u16 rl_create_tbf();
 404 u16 rl_get_tbf();
 405 void rl_done_tbf(u16 t);
 406 void rl_destroy_tbf(u16 t);
 407
 408
 409 // l2tpns.c
 410 clockt now(void);
 411 clockt backoff(u8 try);
 412 void routeset(ipt ip, ipt mask, ipt gw, u8 add);
 413 void inittap(void);
 414 void initudp(void);
 415 void initdata(void);
 416 void initippool();
 417 sessionidt sessionbyip(ipt ip);
 418 sessionidt sessionbyuser(char *username);
 419 void sessionshutdown(sessionidt s, char *reason);
 420 void sessionsendarp(sessionidt s);
 421 void send_garp(ipt ip);
 422 void sessionkill(sessionidt s, char *reason);
 423 void control16(controlt * c, u16 avp, u16 val, u8 m);
 424 void control32(controlt * c, u16 avp, u32 val, u8 m);
 425 void controls(controlt * c, u16 avp, char *val, u8 m);
 426 void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m);
 427 controlt *controlnew(u16 mtype);
 428 void controlnull(tunnelidt t);
 429 void controladd(controlt * c, tunnelidt t, sessionidt s);
 430 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
 431 void tunnelkill(tunnelidt t, char *reason);
 432 void tunnelshutdown(tunnelidt t, char *reason);
 433 void sendipcp(tunnelidt t, sessionidt s);
 434 void processipout(u8 * buf, int len);
 435 void processarp(u8 * buf, int len);
 436 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
 437 void processtap(u8 * buf, int len);
 438 void processcontrol(u8 * buf, int len, struct sockaddr_in *addr);
 439 int assign_ip_address(sessionidt s);
 440 void free_ip_address(sessionidt s);
 441 void snoop_send_packet(char *packet, u16 size);
 442 void dump_acct_info();
 443 void mainloop(void);
 444 #define log _log
 445 #ifndef log_hex
 446 #define log_hex(a,b,c,d) do{if (a <= config->debug) _log_hex(a,0,0,0,b,c,d);}while (0)
 447 #endif
 448 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...) __attribute__((format (printf, 5, 6)));
 449 void _log_hex(int level, ipt address, sessionidt s, tunnelidt t, const char *title, const char *data, int maxsize);
 450 void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response);
 451 int sessionsetup(tunnelidt t, sessionidt s, u8 routes);
 452 int cluster_send_session(int s);
 453 int cluster_send_tunnel(int t);
 454 int cluster_send_goodbye();
 455 void init_cli();
 456 void cli_do_file(FILE *fh);
 457 void cli_do(int sockfd);
 458 #ifdef RINGBUFFER
 459 void ringbuffer_dump(FILE *stream);
 460 #endif
 461 void initplugins();
 462 int run_plugins(int plugin_type, void *data);
 463 void add_plugin(char *plugin_name);
 464 void remove_plugin(char *plugin_name);
 465 void tunnelclear(tunnelidt t);
 466 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
 467
 468 extern tunnelt *tunnel;
 469 extern sessiont *session;
 470 #define sessionfree (session[0].next)
 471
 472 #define log_backtrace(count, max) \
 473 if (count++ < max) { \
 474         void *array[20]; \
 475         char **strings; \
 476         int size, i; \
 477         log(0, 0, 0, t, "Backtrace follows"); \
 478         size = backtrace(array, 10); \
 479         strings = backtrace_symbols(array, size); \
 480         if (strings) for (i = 0; i < size; i++) \
 481         { \
 482                 log(0, 0, 0, t, "%s\n", strings[i]); \
 483         } \
 484         free(strings); \
 485 }
 486