l2tpns.h

   1 // L2TPNS Global Stuff
   2 // $Id: l2tpns.h,v 1.3 2004-03-05 00:22:06 fred_nerk Exp $
   3
   4 #include <netinet/in.h>
   5 #include <stdio.h>
   6 #include "config.h"
   7
   8 #define VERSION "1.1.0"
   9
  10 // Limits
  11 #define MAXTUNNEL       500             // could be up to 65535
  12 #define MAXSESSION      50000           // could be up to 65535
  13 #define MAXRADIUS       255
  14 #define MAXCONTROL      1000            // max length control message we ever send...
  15 #define MAXETHER        (1500+18)       // max packet we try sending to tap
  16 #define MAXTEL          96              // telephone number
  17 #define MAXPLUGINS      20              // maximum number of plugins to load
  18 #define MAXRADSERVER    10              // max radius servers
  19 #define MAXROUTE        10              // max static routes per session
  20 #define MAXIPPOOL       131072          // max number of ip addresses in pool
  21 #define RINGBUFFER_SIZE 10000           // Number of ringbuffer entries to allocate
  22 #define MAX_LOG_LENGTH  512             // Maximum size of log message
  23 #define ECHO_TIMEOUT    60              // Time between last packet sent and LCP ECHO generation
  24 #define IDLE_TIMEOUT    240             // Time between last packet sent and LCP ECHO generation
  25
  26 // Constants
  27 #define STATISTICS
  28 #define STAT_CALLS
  29 #define RINGBUFFER
  30 #define TAPDEVICE       "/dev/net/tun"
  31 #define UDP             17
  32 #define HOMEDIR         "/home/l2tpns/"                 // Base dir for data
  33 #define STATEFILE       "/tmp/l2tpns.dump"              // State dump file
  34 #define NOSTATEFILE     "/tmp/l2tpns.no_state_reload"   // If exists, state will not be reloaded
  35 #define CONFIGFILE      ETCDIR "l2tpns.cfg"     // Configuration file
  36 #define CLIUSERS        ETCDIR "l2tpns.users"           // CLI Users file
  37 #define IPPOOLFILE      ETCDIR "l2tpns.ip_pool"         // Address pool configuration
  38 #ifndef LIBDIR
  39 #define LIBDIR          "/usr/lib/l2tpns"
  40 #endif
  41 #define ACCT_TIME       3000            // 5 minute accounting interval
  42 #define L2TPPORT        1701            // L2TP port
  43 #define RADPORT         1645            // old radius port...
  44 #define RADAPORT        1646            // old radius accounting port
  45 #define PKTARP          0x0806          // ARP packet type
  46 #define PKTIP           0x0800          // IP packet type
  47 #define PSEUDOMAC       0x0200          // pseudo MAC prefix (local significant MAC)
  48 #define PPPPAP          0xC023
  49 #define PPPCHAP         0xC223
  50 #define PPPLCP          0xC021
  51 #define PPPIPCP         0x8021
  52 #define PPPCCP          0x80FD
  53 #define PPPIP           0x0021
  54 #define PPPMP           0x003D
  55 enum
  56 {
  57         ConfigReq = 1,
  58         ConfigAck,
  59         ConfigNak,
  60         ConfigRej,
  61         TerminateReq,
  62         TerminateAck,
  63         CodeRej,
  64         ProtocolRej,
  65         EchoReq,
  66         EchoReply,
  67         DiscardRequest
  68 };
  69
  70 // Types
  71 typedef unsigned short u16;
  72 typedef unsigned int u32;
  73 typedef unsigned char u8;
  74 typedef u32 ipt;
  75 typedef u16 portt;
  76 typedef u16 sessionidt;
  77 typedef u16 tunnelidt;
  78 typedef u32 clockt;
  79 typedef u8 hasht[16];
  80
  81 // dump header: update number if internal format changes
  82 #define DUMP_MAGIC "L2TPNS#" VERSION "#"
  83
  84 // structures
  85 typedef struct routes           // route
  86 {
  87         ipt ip;
  88         ipt mask;
  89 }
  90 routet;
  91
  92 typedef struct controls         // control message
  93 {
  94         struct controls *next;  // next in queue
  95         u16 length;             // length
  96         u8 buf[MAXCONTROL];
  97 }
  98 controlt;
  99
 100 typedef struct stbft
 101 {
 102     struct stbft *next;
 103     char handle[10];
 104     char in_use;
 105     int mark;
 106 } tbft;
 107
 108
 109 // 336 bytes per session
 110 typedef struct sessions
 111 {
 112         sessionidt next;                // next session in linked list
 113         sessionidt far;                 // far end session ID
 114         tunnelidt tunnel;               // tunnel ID
 115         ipt ip;                         // IP of session set by RADIUS response
 116         int ip_pool_index;              // index to IP pool
 117         unsigned long sid;              // session id for hsddb
 118         u16 nr;                         // next receive
 119         u16 ns;                         // next send
 120         u32 magic;                      // ppp magic number
 121         u32 cin, cout;                  // byte counts
 122         u32 pin, pout;                  // packet counts
 123         u32 total_cin;                  // This counter is never reset while a session is open
 124         u32 total_cout;                 // This counter is never reset while a session is open
 125         u32 id;                         // session id
 126         clockt opened;                  // when started
 127         clockt die;                     // being closed, when to finally free
 128         time_t last_packet;             // Last packet from the user (used for idle timeouts)
 129         ipt dns1, dns2;                 // DNS servers
 130         routet route[MAXROUTE];         // static routes
 131         u8 radius;                      // which radius session is being used (0 for not waiting on authentication)
 132         u8 flags;                       // various bit flags
 133         u8 snoop;                       // are we snooping this session?
 134         u8 throttle;                    // is this session throttled?
 135         u8 walled_garden;               // is this session gardened?
 136         u16 mru;                        // maximum receive unit
 137         u16 tbf;                        // filter bucket for throttling
 138         char random_vector[MAXTEL];
 139         int random_vector_length;
 140         char user[129];                 // user (needed in seesion for radius stop messages)
 141         char called[MAXTEL];            // called number
 142         char calling[MAXTEL];           // calling number
 143         unsigned long tx_connect_speed;
 144         unsigned long rx_connect_speed;
 145 }
 146 sessiont;
 147
 148 #define SESSIONPFC      1            // PFC negotiated flags
 149 #define SESSIONACFC     2           // ACFC negotiated flags
 150
 151 // 168 bytes per tunnel
 152 typedef struct tunnels
 153 {
 154         tunnelidt far;          // far end tunnel ID
 155         ipt ip;                 // Ip for far end
 156         portt port;             // port for far end
 157         u16 window;             // Rx window
 158         u16 nr;                 // next receive
 159         u16 ns;                 // next send
 160         int state;              // current state (tunnelstate enum)
 161         clockt last;            // when last control message sent (used for resend timeout)
 162         clockt retry;           // when to try resenting pending control
 163         clockt die;             // being closed, when to finally free
 164         clockt lastrec;         // when the last control message was received
 165         char hostname[128];     // tunnel hostname
 166         char vendor[128];       // LAC vendor
 167         u8 try;                 // number of retrys on a control message
 168         u16 controlc;           // outstaind messages in queue
 169         controlt *controls;     // oldest message
 170         controlt *controle;     // newest message
 171 }
 172 tunnelt;
 173
 174 // 180 bytes per radius session
 175 typedef struct radiuss          // outstanding RADIUS requests
 176 {
 177         sessionidt session;          // which session this applies to
 178         hasht auth;               // request authenticator
 179         clockt retry;              // when to try next
 180         char calling[MAXTEL];    // calling number
 181         char pass[129];          // password
 182         u8 id;                 // ID for PPP response
 183         u8 try;                // which try we are on
 184         u8 state;              // state of radius requests
 185         u8 chap;               // set if CHAP used (is CHAP identifier)
 186 }
 187 radiust;
 188
 189 typedef struct
 190 {
 191         ipt     address;
 192         char    assigned;       // 1 if assigned, 0 if free
 193         clockt  last;           // last used
 194         char    user[129];      // user (try to have ip addresses persistent)
 195 }
 196 ippoolt;
 197
 198 #ifdef RINGBUFFER
 199 struct Tringbuffer
 200 {
 201         struct {
 202                 char level;
 203                 sessionidt session;
 204                 tunnelidt tunnel;
 205                 ipt address;
 206                 char message[MAX_LOG_LENGTH];
 207         } buffer[RINGBUFFER_SIZE];
 208         int head;
 209         int tail;
 210 };
 211 #endif
 212
 213 /*
 214  * Possible tunnel states
 215  * TUNNELFREE -> TUNNELOPEN -> TUNNELDIE -> TUNNELFREE
 216  */
 217 enum
 218 {
 219         TUNNELFREE,             // Not in use
 220         TUNNELOPEN,             // Active tunnel
 221         TUNNELDIE,              // Currently closing
 222         TUNNELOPENING           // Busy opening
 223 };
 224
 225 enum
 226 {
 227         RADIUSNULL,             // Not in use
 228         RADIUSCHAP,             // sending CHAP down PPP
 229         RADIUSAUTH,             // sending auth to RADIUS server
 230         RADIUSIPCP,             // sending IPCP to end user
 231         RADIUSSTART,            // sending start accounting to RADIUS server
 232         RADIUSSTOP,             // sending stop accounting to RADIUS server
 233         RADIUSWAIT              // waiting timeout before available, in case delayed replies
 234 };
 235
 236 struct Tstats
 237 {
 238     time_t              start_time;
 239     time_t              last_reset;
 240
 241     unsigned long       tap_rx_packets;
 242     unsigned long       tap_tx_packets;
 243     unsigned long       tap_rx_bytes;
 244     unsigned long       tap_tx_bytes;
 245     unsigned long       tap_rx_errors;
 246     unsigned long       tap_tx_errors;
 247
 248     unsigned long       tunnel_rx_packets;
 249     unsigned long       tunnel_tx_packets;
 250     unsigned long       tunnel_rx_bytes;
 251     unsigned long       tunnel_tx_bytes;
 252     unsigned long       tunnel_rx_errors;
 253     unsigned long       tunnel_tx_errors;
 254
 255     unsigned long       tunnel_retries;
 256     unsigned long       radius_retries;
 257
 258     unsigned long       arp_errors;
 259     unsigned long       arp_replies;
 260     unsigned long       arp_discarded;
 261     unsigned long       arp_sent;
 262     unsigned long       arp_recv;
 263
 264     unsigned long       packets_snooped;
 265
 266     unsigned long       tunnel_created;
 267     unsigned long       session_created;
 268     unsigned long       tunnel_timeout;
 269     unsigned long       session_timeout;
 270     unsigned long       radius_timeout;
 271     unsigned long       radius_overflow;
 272     unsigned long       tunnel_overflow;
 273     unsigned long       session_overflow;
 274
 275     unsigned long       ip_allocated;
 276     unsigned long       ip_freed;
 277 #ifdef STAT_CALLS
 278     unsigned long       call_processtap;
 279     unsigned long       call_processarp;
 280     unsigned long       call_processipout;
 281     unsigned long       call_processudp;
 282     unsigned long       call_sessionbyip;
 283     unsigned long       call_sessionbyuser;
 284     unsigned long       call_sendarp;
 285     unsigned long       call_sendipcp;
 286     unsigned long       call_tunnelsend;
 287     unsigned long       call_sessionkill;
 288     unsigned long       call_sessionshutdown;
 289     unsigned long       call_tunnelkill;
 290     unsigned long       call_tunnelshutdown;
 291     unsigned long       call_assign_ip_address;
 292     unsigned long       call_free_ip_address;
 293     unsigned long       call_dump_acct_info;
 294     unsigned long       call_sessionsetup;
 295     unsigned long       call_processpap;
 296     unsigned long       call_processchap;
 297     unsigned long       call_processlcp;
 298     unsigned long       call_processipcp;
 299     unsigned long       call_processipin;
 300     unsigned long       call_processccp;
 301     unsigned long       call_sendchap;
 302     unsigned long       call_processrad;
 303     unsigned long       call_radiussend;
 304     unsigned long       call_radiusretry;
 305 #endif
 306 };
 307
 308 #ifdef STATISTICS
 309 #define STAT(x)         _statistics->x++
 310 #define INC_STAT(x,y)   _statistics->x += y
 311 #define GET_STAT(x)     _statistics->x
 312 #define SET_STAT(x, y)  _statistics->x = y
 313 #else
 314 #define STAT(x)
 315 #define INC_STAT(x,y)
 316 #define GET_STAT(x)     0
 317 #define SET_STAT(x, y)
 318 #endif
 319
 320 struct configt
 321 {
 322         int             debug;                          // debugging level
 323         time_t          start_time;                     // time when l2tpns was started
 324         char            bandwidth[256];                 // current bandwidth
 325
 326         char            config_file[128];
 327         int             reload_config;                  // flag to re-read config (set by cli)
 328
 329         char            tapdevice[10];                  // tap device name
 330         char            log_filename[128];
 331         char            l2tpsecret[64];
 332
 333         char            radiussecret[64];
 334         int             radius_accounting;
 335         ipt             radiusserver[MAXRADSERVER];     // radius servers
 336         u8              numradiusservers;               // radius server count
 337
 338         ipt             default_dns1, default_dns2;
 339
 340         ipt             snoop_destination_host;
 341         u16             snoop_destination_port;
 342
 343         unsigned long   rl_rate;
 344         int             save_state;
 345         uint32_t        cluster_address;
 346         int             ignore_cluster_updates;
 347         char            accounting_dir[128];
 348         ipt             bind_address;
 349         int             target_uid;
 350         int             dump_speed;
 351         char            plugins[64][MAXPLUGINS];
 352         char            old_plugins[64][MAXPLUGINS];
 353 };
 354
 355 struct config_descriptt
 356 {
 357         char *key;
 358         int offset;
 359         int size;
 360         enum { INT, STRING, UNSIGNED_LONG, SHORT, BOOL, IP } type;
 361 };
 362
 363 // arp.c
 364 void sendarp(int ifr_idx, const unsigned char* mac, ipt ip);
 365
 366
 367 // ppp.c
 368 void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 369 void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l);
 370 void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 371 void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 372 void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l);
 373 void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l);
 374 void sendchap(tunnelidt t, sessionidt s);
 375 u8 *makeppp(u8 * b, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype);
 376 u8 *findppp(u8 * b, u8 mtype);
 377 void initlcp(tunnelidt t, sessionidt s);
 378 void dumplcp(char *p, int l);
 379
 380
 381 // radius.c
 382 void initrad(void);
 383 void radiussend(u8 r, u8 state);
 384 void processrad(u8 *buf, int len);
 385 void radiusretry(u8 r);
 386 u8 radiusnew(sessionidt s);
 387 void radiusclear(u8 r, sessionidt s);
 388
 389 // throttle.c
 390 int throttle_session(sessionidt s, int throttle);
 391
 392
 393 // rl.c
 394 void init_rl();
 395 u16 rl_create_tbf();
 396 u16 rl_get_tbf();
 397 void rl_done_tbf(u16 t);
 398 void rl_destroy_tbf(u16 t);
 399
 400
 401 // l2tpns.c
 402 clockt now(void);
 403 clockt backoff(u8 try);
 404 void routeset(ipt ip, ipt mask, ipt gw, u8 add);
 405 void inittap(void);
 406 void initudp(void);
 407 void initdata(void);
 408 void initippool();
 409 sessionidt sessionbyip(ipt ip);
 410 sessionidt sessionbyuser(char *username);
 411 void sessionshutdown(sessionidt s, char *reason);
 412 void sessionsendarp(sessionidt s);
 413 void send_garp(ipt ip);
 414 void sessionkill(sessionidt s, char *reason);
 415 void control16(controlt * c, u16 avp, u16 val, u8 m);
 416 void control32(controlt * c, u16 avp, u32 val, u8 m);
 417 void controls(controlt * c, u16 avp, char *val, u8 m);
 418 void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m);
 419 controlt *controlnew(u16 mtype);
 420 void controlnull(tunnelidt t);
 421 void controladd(controlt * c, tunnelidt t, sessionidt s);
 422 void tunnelsend(u8 * buf, u16 l, tunnelidt t);
 423 void tunnelkill(tunnelidt t, char *reason);
 424 void tunnelshutdown(tunnelidt t, char *reason);
 425 void sendipcp(tunnelidt t, sessionidt s);
 426 void processipout(u8 * buf, int len);
 427 void processarp(u8 * buf, int len);
 428 void processudp(u8 * buf, int len, struct sockaddr_in *addr);
 429 void processtap(u8 * buf, int len);
 430 void processcontrol(u8 * buf, int len, struct sockaddr_in *addr);
 431 int assign_ip_address(sessionidt s);
 432 void free_ip_address(sessionidt s);
 433 void snoop_send_packet(char *packet, u16 size);
 434 void dump_acct_info();
 435 void mainloop(void);
 436 #define log _log
 437 #ifndef log_hex
 438 #define log_hex(a,b,c,d) do{if (a <= config->debug) _log_hex(a,0,0,0,b,c,d);}while (0)
 439 #endif
 440 void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...);
 441 void _log_hex(int level, ipt address, sessionidt s, tunnelidt t, const char *title, const char *data, int maxsize);
 442 void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response);
 443 int sessionsetup(tunnelidt t, sessionidt s, u8 routes);
 444 int cluster_send_session(int s);
 445 int cluster_send_tunnel(int t);
 446 int cluster_send_goodbye();
 447 void init_cli();
 448 void cli_do_file(FILE *fh);
 449 void cli_do(int sockfd);
 450 #ifdef RINGBUFFER
 451 void ringbuffer_dump(FILE *stream);
 452 #endif
 453 void initplugins();
 454 int run_plugins(int plugin_type, void *data);
 455 void add_plugin(char *plugin_name);
 456 void remove_plugin(char *plugin_name);
 457 void tunnelclear(tunnelidt t);
 458 void host_unreachable(ipt destination, u16 id, ipt source, char *packet, int packet_len);
 459
 460 extern tunnelt *tunnel;
 461 extern sessiont *session;
 462 #define sessionfree (session[0].next)