mdw@git.distorted.org.uk Git - tripe/blob - tripe.h

   1 /* -*-c-*-
   2  *
   3  * $Id$
   4  *
   5  * Main header file for TrIPE
   6  *
   7  * (c) 2001 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Trivial IP Encryption (TrIPE).
  13  *
  14  * TrIPE is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * TrIPE is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with TrIPE; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 #ifndef TRIPE_H
  30 #define TRIPE_H
  31
  32 #ifdef __cplusplus
  33   extern "C" {
  34 #endif
  35
  36 /*----- Header files ------------------------------------------------------*/
  37
  38 #include "config.h"
  39
  40 #include <assert.h>
  41 #include <ctype.h>
  42 #include <errno.h>
  43 #include <limits.h>
  44 #include <signal.h>
  45 #include <stdarg.h>
  46 #include <stddef.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <time.h>
  51
  52 #include <sys/types.h>
  53 #include <sys/time.h>
  54 #include <unistd.h>
  55 #include <fcntl.h>
  56 #include <sys/stat.h>
  57
  58 #include <sys/socket.h>
  59 #include <sys/un.h>
  60 #include <netinet/in.h>
  61 #include <arpa/inet.h>
  62 #include <netdb.h>
  63
  64 #include <pwd.h>
  65 #include <grp.h>
  66
  67 #include <mLib/alloc.h>
  68 #include <mLib/arena.h>
  69 #include <mLib/bres.h>
  70 #include <mLib/dstr.h>
  71 #include <mLib/env.h>
  72 #include <mLib/fdflags.h>
  73 #include <mLib/fwatch.h>
  74 #include <mLib/mdwopt.h>
  75 #include <mLib/quis.h>
  76 #include <mLib/report.h>
  77 #include <mLib/sel.h>
  78 #include <mLib/selbuf.h>
  79 #include <mLib/sig.h>
  80 #include <mLib/str.h>
  81 #include <mLib/sub.h>
  82 #include <mLib/trace.h>
  83 #include <mLib/tv.h>
  84
  85 #include <catacomb/buf.h>
  86
  87 #include <catacomb/gcipher.h>
  88 #include <catacomb/gmac.h>
  89 #include <catacomb/grand.h>
  90 #include <catacomb/key.h>
  91 #include <catacomb/paranoia.h>
  92
  93 #include <catacomb/noise.h>
  94 #include <catacomb/rand.h>
  95
  96 #include <catacomb/mp.h>
  97 #include <catacomb/mprand.h>
  98 #include <catacomb/dh.h>
  99 #include <catacomb/ec.h>
 100 #include <catacomb/ec-keys.h>
 101 #include <catacomb/group.h>
 102
 103 #include "tripe-protocol.h"
 104 #include "util.h"
 105
 106 #undef sun
 107
 108 /*----- Magic numbers -----------------------------------------------------*/
 109
 110 /* --- Trace flags --- */
 111
 112 #define T_TUNNEL 1u
 113 #define T_PEER 2u
 114 #define T_PACKET 4u
 115 #define T_ADMIN 8u
 116 #define T_CRYPTO 16u
 117 #define T_KEYSET 32u
 118 #define T_KEYEXCH 64u
 119 #define T_KEYMGMT 128u
 120
 121 #define T_ALL 255u
 122
 123 /* --- Units --- */
 124
 125 #define SEC(n) (n##u)
 126 #define MIN(n) (n##u * 60u)
 127 #define MEG(n) (n##ul * 1024ul * 1024ul)
 128
 129 /* --- Other things --- */
 130
 131 #define PKBUFSZ 65536
 132
 133 /*----- Cipher selections -------------------------------------------------*/
 134
 135 typedef struct algswitch {
 136   const gccipher *c;                    /* Symmetric encryption scheme */
 137   const gccipher *mgf;                  /* Mask-generation function */
 138   const gchash *h;                      /* Hash function */
 139   const gcmac *m;                       /* Message authentication code */
 140   size_t hashsz;                        /* Hash output size */
 141   size_t tagsz;                         /* Length to truncate MAC tags */
 142   size_t cksz, mksz;                    /* Key lengths for @c@ and @m@ */
 143 } algswitch;
 144
 145 extern algswitch algs;
 146
 147 #define MAXHASHSZ 64                    /* Largest possible hash size */
 148
 149 #define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s))
 150
 151 /*----- Data structures ---------------------------------------------------*/
 152
 153 /* --- Socket addresses --- *
 154  *
 155  * A magic union of supported socket addresses.
 156  */
 157
 158 typedef union addr {
 159   struct sockaddr sa;
 160   struct sockaddr_in sin;
 161 } addr;
 162
 163 /* --- A symmetric keyset --- *
 164  *
 165  * A keyset contains a set of symmetric keys for encrypting and decrypting
 166  * packets.  Keysets are stored in a list, sorted in reverse order of
 167  * creation, so that the most recent keyset (the one most likely to be used)
 168  * is first.
 169  *
 170  * Each keyset has a time limit and a data limit.  The keyset is destroyed
 171  * when either it has existed for too long, or it has been used to encrypt
 172  * too much data.  New key exchanges are triggered when keys are close to
 173  * expiry.
 174  */
 175
 176 typedef struct keyset {
 177   struct keyset *next;                  /* Next active keyset in the list */
 178   unsigned ref;                         /* Reference count for keyset */
 179   struct peer *p;                       /* Pointer to peer structure */
 180   time_t t_exp;                         /* Expiry time for this keyset */
 181   unsigned long sz_exp;                 /* Data limit for the keyset */
 182   T( unsigned seq; )                    /* Sequence number for tracing */
 183   unsigned f;                           /* Various useful flags */
 184   gcipher *cin, *cout;                  /* Keyset ciphers for encryption */
 185   size_t tagsz;                         /* Length to truncate MAC tags */
 186   gmac *min, *mout;                     /* Keyset MACs for integrity */
 187   uint32 oseq;                          /* Outbound sequence number */
 188   uint32 iseq, iwin;                    /* Inbound sequence number */
 189 } keyset;
 190
 191 #define KS_SEQWINSZ 32                  /* Bits in sequence number window */
 192
 193 #define KSF_LISTEN 1u                   /* Don't encrypt packets yet */
 194 #define KSF_LINK 2u                     /* Key is in a linked list */
 195
 196 /* --- Key exchange --- *
 197  *
 198  * TrIPE uses the Wrestlers Protocol for its key exchange.  The Wrestlers
 199  * Protocol has a number of desirable features (e.g., perfect forward
 200  * secrecy, and zero-knowledge authentication) which make it attractive for
 201  * use in TrIPE.  The Wrestlers Protocol was designed by Mark Wooding and
 202  * Clive Jones.
 203  */
 204
 205 #define KX_NCHAL 16u
 206 #define KX_THRESH 4u
 207
 208 typedef struct kxchal {
 209   struct keyexch *kx;                   /* Pointer back to key exchange */
 210   ge *c;                                /* Responder's challenge */
 211   ge *r;                                /* My reply to the challenge */
 212   keyset *ks;                           /* Pointer to temporary keyset */
 213   unsigned f;                           /* Various useful flags */
 214   sel_timer t;                          /* Response timer for challenge */
 215   octet hc[MAXHASHSZ];                  /* Hash of his challenge */
 216   mp *ck;                               /* The check value */
 217   octet hswrq_in[MAXHASHSZ];            /* Inbound switch request message */
 218   octet hswok_in[MAXHASHSZ];            /* Inbound switch confirmation */
 219   octet hswrq_out[MAXHASHSZ];           /* Outbound switch request message */
 220   octet hswok_out[MAXHASHSZ];           /* Outbound switch confirmation */
 221 } kxchal;
 222
 223 typedef struct keyexch {
 224   struct peer *p;                       /* Pointer back to the peer */
 225   keyset **ks;                          /* Peer's list of keysets */
 226   unsigned f;                           /* Various useful flags */
 227   unsigned s;                           /* Current state in exchange */
 228   sel_timer t;                          /* Timer for next exchange */
 229   ge *kpub;                             /* Peer's public key */
 230   time_t texp_kpub;                     /* Expiry time for public key */
 231   mp *alpha;                            /* My temporary secret */
 232   ge *c;                                /* My challenge */
 233   ge *rx;                               /* The expected response */
 234   unsigned nr;                          /* Number of extant responses */
 235   time_t t_valid;                       /* When this exchange goes bad */
 236   octet hc[MAXHASHSZ];                  /* Hash of my challenge */
 237   kxchal *r[KX_NCHAL];                  /* Array of challenges */
 238 } keyexch;
 239
 240 #define KXF_TIMER 1u                    /* Waiting for a timer to go off */
 241 #define KXF_DEAD 2u                     /* The key-exchanger isn't up */
 242 #define KXF_PUBKEY 4u                   /* Key exchanger has a public key */
 243
 244 enum {
 245   KXS_DEAD,                             /* Uninitialized state (magical) */
 246   KXS_CHAL,                             /* Main answer-challenges state */
 247   KXS_COMMIT,                           /* Committed: send switch request */
 248   KXS_SWITCH                            /* Switched: send confirmation */
 249 };
 250
 251 /* --- Tunnel structure --- *
 252  *
 253  * Used to maintain system-specific information about the tunnel interface.
 254  */
 255
 256 typedef struct tunnel tunnel;
 257 struct peer;
 258
 259 typedef struct tunnel_ops {
 260   const char *name;                     /* Name of this tunnel driver */
 261   void (*init)(void);                   /* Initializes the system */
 262   tunnel *(*create)(struct peer */*p*/); /* Initializes a new tunnel */
 263   const char *(*ifname)(tunnel */*t*/); /* Returns tunnel's interface name */
 264   void (*inject)(tunnel */*t*/, buf */*b*/); /* Sends packet through if */
 265   void (*destroy)(tunnel */*t*/);       /* Destroys a tunnel */
 266 } tunnel_ops;
 267
 268 #ifndef TUN_INTERNALS
 269 struct tunnel { const tunnel_ops *ops; };
 270 #endif
 271
 272 /* --- Peer statistics --- *
 273  *
 274  * Contains various interesting and not-so-interesting statistics about a
 275  * peer.  This is updated by various parts of the code.  The format of the
 276  * structure isn't considered private, and @p_stats@ returns a pointer to the
 277  * statistics block for a given peer.
 278  */
 279
 280 typedef struct stats {
 281   unsigned long sz_in, sz_out;          /* Size of all data in and out */
 282   unsigned long sz_kxin, sz_kxout;      /* Size of key exchange messages */
 283   unsigned long sz_ipin, sz_ipout;      /* Size of encapsulated IP packets */
 284   time_t t_start, t_last, t_kx;         /* Time peer created, last pk, kx */
 285   unsigned long n_reject;               /* Number of rejected packets */
 286   unsigned long n_in, n_out;            /* Number of packets in and out */
 287   unsigned long n_kxin, n_kxout;        /* Number of key exchange packets */
 288   unsigned long n_ipin, n_ipout;        /* Number of encrypted packets */
 289 } stats;
 290
 291 /* --- Peer structure --- *
 292  *
 293  * The main structure which glues everything else together.
 294  */
 295
 296 typedef struct peerspec {
 297   char *name;                           /* Peer's name */
 298   const tunnel_ops *tops;               /* Tunnel operations */
 299   unsigned long t_ka;                   /* Keep alive interval */
 300   addr sa;                              /* Socket address to speak to */
 301   size_t sasz;                          /* Socket address size */
 302 } peerspec;
 303
 304 typedef struct peer {
 305   struct peer *next, *prev;             /* Links to next and previous */
 306   struct ping *pings;                   /* Pings we're waiting for */
 307   peerspec spec;                        /* Specifications for this peer */
 308   tunnel *t;                            /* Tunnel for local packets */
 309   keyset *ks;                           /* List head for keysets */
 310   buf b;                                /* Buffer for sending packets */
 311   stats st;                             /* Statistics */
 312   keyexch kx;                           /* Key exchange protocol block */
 313   sel_timer tka;                        /* Timer for keepalives */
 314 } peer;
 315
 316 typedef struct ping {
 317   struct ping *next, *prev;             /* Links to next and previous */
 318   peer *p;                              /* Peer so we can free it */
 319   unsigned msg;                         /* Kind of response expected */
 320   uint32 id;                            /* Id so we can recognize response */
 321   octet magic[32];                      /* Some random data */
 322   sel_timer t;                          /* Timeout for ping */
 323   void (*func)(int /*rc*/, void */*arg*/); /* Function to call when done */
 324   void *arg;                            /* Argument for callback */
 325 } ping;
 326
 327 enum {
 328   PING_NONOTIFY = -1,
 329   PING_OK = 0,
 330   PING_TIMEOUT,
 331   PING_PEERDIED,
 332   PING_MAX
 333 };
 334
 335 /* --- Admin structure --- */
 336
 337 #define OBUFSZ 16384u
 338
 339 typedef struct obuf {
 340   struct obuf *next;                    /* Next buffer in list */
 341   char *p_in, *p_out;                   /* Pointers into the buffer */
 342   char buf[OBUFSZ];                     /* The actual buffer */
 343 } obuf;
 344
 345 typedef struct admin {
 346   struct admin *next, *prev;            /* Links to next and previous */
 347   unsigned f;                           /* Various useful flags */
 348 #ifndef NTRACE
 349   unsigned seq;                         /* Sequence number for tracing */
 350 #endif
 351   obuf *o_head, *o_tail;                /* Output buffer list */
 352   selbuf b;                             /* Line buffer for commands */
 353   sel_file w;                           /* Selector for write buffering */
 354   peerspec peer;                        /* Peer pending creation */
 355   char *paddr;                          /* Hostname to be resolved */
 356   bres_client r;                        /* Background resolver task */
 357   sel_timer t;                          /* Timer for resolver */
 358   ping ping;                            /* Ping pending response */
 359   struct timeval pingtime;              /* Time last ping was sent */
 360 } admin;
 361
 362 #define AF_DEAD 1u                      /* Destroy this admin block */
 363 #define AF_LOCK 2u                      /* Don't destroy it yet */
 364 #define AF_NOTE 4u                      /* Catch notifications */
 365 #ifndef NTRACE
 366   #define AF_TRACE 8u                   /* Catch tracing */
 367 #endif
 368 #define AF_WARN 16u                     /* Catch warning messages */
 369
 370 #ifndef NTRACE
 371 #  define AF_ALLMSGS (AF_NOTE | AF_TRACE | AF_WARN)
 372 #else
 373 #  define AF_ALLMSGS (AF_NOTE | AF_WARN)
 374 #endif
 375
 376 /*----- Global variables --------------------------------------------------*/
 377
 378 extern sel_state sel;                   /* Global I/O event state */
 379 extern group *gg;                       /* The group we work in */
 380 extern mp *kpriv;                       /* Our private key */
 381 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
 382 extern const tunnel_ops *tunnels[];     /* Table of tunnels (0-term) */
 383 extern const tunnel_ops *tun_default;   /* Default tunnel to use */
 384
 385 #ifndef NTRACE
 386 extern const trace_opt tr_opts[];       /* Trace options array */
 387 extern unsigned tr_flags;               /* Trace options flags */
 388 #endif
 389
 390 /*----- Other macros ------------------------------------------------------*/
 391
 392 #define TIMER noise_timer(RAND_GLOBAL)
 393
 394 /*----- Key management ----------------------------------------------------*/
 395
 396 /* --- @km_interval@ --- *
 397  *
 398  * Arguments:   ---
 399  *
 400  * Returns:     Zero if OK, nonzero to force reloading of keys.
 401  *
 402  * Use:         Called on the interval timer to perform various useful jobs.
 403  */
 404
 405 extern int km_interval(void);
 406
 407 /* --- @km_init@ --- *
 408  *
 409  * Arguments:   @const char *kr_priv@ = private keyring file
 410  *              @const char *kr_pub@ = public keyring file
 411  *              @const char *tag@ = tag to load
 412  *
 413  * Returns:     ---
 414  *
 415  * Use:         Initializes, and loads the private key.
 416  */
 417
 418 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
 419                     const char */*tag*/);
 420
 421 /* --- @km_getpubkey@ --- *
 422  *
 423  * Arguments:   @const char *tag@ = public key tag to load
 424  *              @ge *kpub@ = where to put the public key
 425  *              @time_t *t_exp@ = where to put the expiry time
 426  *
 427  * Returns:     Zero if OK, nonzero if it failed.
 428  *
 429  * Use:         Fetches a public key from the keyring.
 430  */
 431
 432 extern int km_getpubkey(const char */*tag*/, ge */*kpub*/,
 433                         time_t */*t_exp*/);
 434
 435 /*----- Key exchange ------------------------------------------------------*/
 436
 437 /* --- @kx_start@ --- *
 438  *
 439  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 440  *
 441  * Returns:     ---
 442  *
 443  * Use:         Stimulates a key exchange.  If a key exchage is in progress,
 444  *              a new challenge is sent (unless the quiet timer forbids
 445  *              this); if no exchange is in progress, one is commenced.
 446  */
 447
 448 extern void kx_start(keyexch */*kx*/);
 449
 450 /* --- @kx_message@ --- *
 451  *
 452  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 453  *              @unsigned msg@ = the message code
 454  *              @buf *b@ = pointer to buffer containing the packet
 455  *
 456  * Returns:     ---
 457  *
 458  * Use:         Reads a packet containing key exchange messages and handles
 459  *              it.
 460  */
 461
 462 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
 463
 464 /* --- @kx_free@ --- *
 465  *
 466  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 467  *
 468  * Returns:     ---
 469  *
 470  * Use:         Frees everything in a key exchange context.
 471  */
 472
 473 extern void kx_free(keyexch */*kx*/);
 474
 475 /* --- @kx_newkeys@ --- *
 476  *
 477  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 478  *
 479  * Returns:     ---
 480  *
 481  * Use:         Informs the key exchange module that its keys may have
 482  *              changed.  If fetching the new keys fails, the peer will be
 483  *              destroyed, we log messages and struggle along with the old
 484  *              keys.
 485  */
 486
 487 extern void kx_newkeys(keyexch */*kx*/);
 488
 489 /* --- @kx_init@ --- *
 490  *
 491  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 492  *              @peer *p@ = pointer to peer context
 493  *              @keyset **ks@ = pointer to keyset list
 494  *
 495  * Returns:     Zero if OK, nonzero if it failed.
 496  *
 497  * Use:         Initializes a key exchange module.  The module currently
 498  *              contains no keys, and will attempt to initiate a key
 499  *              exchange.
 500  */
 501
 502 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
 503
 504 /*----- Keysets and symmetric cryptography --------------------------------*/
 505
 506 /* --- @ks_drop@ --- *
 507  *
 508  * Arguments:   @keyset *ks@ = pointer to a keyset
 509  *
 510  * Returns:     ---
 511  *
 512  * Use:         Decrements a keyset's reference counter.  If the counter hits
 513  *              zero, the keyset is freed.
 514  */
 515
 516 extern void ks_drop(keyset */*ks*/);
 517
 518 /* --- @ks_gen@ --- *
 519  *
 520  * Arguments:   @const void *k@ = pointer to key material
 521  *              @size_t x, y, z@ = offsets into key material (see below)
 522  *              @peer *p@ = pointer to peer information
 523  *
 524  * Returns:     A pointer to the new keyset.
 525  *
 526  * Use:         Derives a new keyset from the given key material.  The
 527  *              offsets @x@, @y@ and @z@ separate the key material into three
 528  *              parts.  Between the @k@ and @k + x@ is `my' contribution to
 529  *              the key material; between @k + x@ and @k + y@ is `your'
 530  *              contribution; and between @k + y@ and @k + z@ is a shared
 531  *              value we made together.  These are used to construct two
 532  *              pairs of symmetric keys.  Each pair consists of an encryption
 533  *              key and a message authentication key.  One pair is used for
 534  *              outgoing messages, the other for incoming messages.
 535  *
 536  *              The new key is marked so that it won't be selected for output
 537  *              by @ksl_encrypt@.  You can still encrypt data with it by
 538  *              calling @ks_encrypt@ directly.
 539  */
 540
 541 extern keyset *ks_gen(const void */*k*/,
 542                       size_t /*x*/, size_t /*y*/, size_t /*z*/,
 543                       peer */*p*/);
 544
 545 /* --- @ks_tregen@ --- *
 546  *
 547  * Arguments:   @keyset *ks@ = pointer to a keyset
 548  *
 549  * Returns:     The time at which moves ought to be made to replace this key.
 550  */
 551
 552 extern time_t ks_tregen(keyset */*ks*/);
 553
 554 /* --- @ks_activate@ --- *
 555  *
 556  * Arguments:   @keyset *ks@ = pointer to a keyset
 557  *
 558  * Returns:     ---
 559  *
 560  * Use:         Activates a keyset, so that it can be used for encrypting
 561  *              outgoing messages.
 562  */
 563
 564 extern void ks_activate(keyset */*ks*/);
 565
 566 /* --- @ks_encrypt@ --- *
 567  *
 568  * Arguments:   @keyset *ks@ = pointer to a keyset
 569  *              @unsigned ty@ = message type
 570  *              @buf *b@ = pointer to input buffer
 571  *              @buf *bb@ = pointer to output buffer
 572  *
 573  * Returns:     Zero if OK, nonzero if the key needs replacing.  If the
 574  *              encryption failed, the output buffer is broken and zero is
 575  *              returned.
 576  *
 577  * Use:         Encrypts a block of data using the key.  Note that the `key
 578  *              ought to be replaced' notification is only ever given once
 579  *              for each key.  Also note that this call forces a keyset to be
 580  *              used even if it's marked as not for data output.
 581  */
 582
 583 extern int ks_encrypt(keyset */*ks*/, unsigned /*ty*/,
 584                       buf */*b*/, buf */*bb*/);
 585
 586 /* --- @ks_decrypt@ --- *
 587  *
 588  * Arguments:   @keyset *ks@ = pointer to a keyset
 589  *              @unsigned ty@ = expected type code
 590  *              @buf *b@ = pointer to an input buffer
 591  *              @buf *bb@ = pointer to an output buffer
 592  *
 593  * Returns:     Zero on success, or nonzero if there was some problem.
 594  *
 595  * Use:         Attempts to decrypt a message using a given key.  Note that
 596  *              requesting decryption with a key directly won't clear a
 597  *              marking that it's not for encryption.
 598  */
 599
 600 extern int ks_decrypt(keyset */*ks*/, unsigned /*ty*/,
 601                       buf */*b*/, buf */*bb*/);
 602
 603 /* --- @ksl_free@ --- *
 604  *
 605  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 606  *
 607  * Returns:     ---
 608  *
 609  * Use:         Frees (releases references to) all of the keys in a keyset.
 610  */
 611
 612 extern void ksl_free(keyset **/*ksroot*/);
 613
 614 /* --- @ksl_link@ --- *
 615  *
 616  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 617  *              @keyset *ks@ = pointer to a keyset
 618  *
 619  * Returns:     ---
 620  *
 621  * Use:         Links a keyset into a list.  A keyset can only be on one list
 622  *              at a time.  Bad things happen otherwise.
 623  */
 624
 625 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
 626
 627 /* --- @ksl_prune@ --- *
 628  *
 629  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 630  *
 631  * Returns:     ---
 632  *
 633  * Use:         Prunes the keyset list by removing keys which mustn't be used
 634  *              any more.
 635  */
 636
 637 extern void ksl_prune(keyset **/*ksroot*/);
 638
 639 /* --- @ksl_encrypt@ --- *
 640  *
 641  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 642  *              @unsigned ty@ = message type
 643  *              @buf *b@ = pointer to input buffer
 644  *              @buf *bb@ = pointer to output buffer
 645  *
 646  * Returns:     Nonzero if a new key is needed.
 647  *
 648  * Use:         Encrypts a packet.
 649  */
 650
 651 extern int ksl_encrypt(keyset **/*ksroot*/, unsigned /*ty*/,
 652                        buf */*b*/, buf */*bb*/);
 653
 654 /* --- @ksl_decrypt@ --- *
 655  *
 656  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 657  *              @unsigned ty@ = expected type code
 658  *              @buf *b@ = pointer to input buffer
 659  *              @buf *bb@ = pointer to output buffer
 660  *
 661  * Returns:     Nonzero if the packet couldn't be decrypted.
 662  *
 663  * Use:         Decrypts a packet.
 664  */
 665
 666 extern int ksl_decrypt(keyset **/*ksroot*/, unsigned /*ty*/,
 667                        buf */*b*/, buf */*bb*/);
 668
 669 /*----- Administration interface ------------------------------------------*/
 670
 671 /* --- @a_warn@ --- *
 672  *
 673  * Arguments:   @const char *fmt@ = pointer to format string
 674  *              @...@ = other arguments
 675  *
 676  * Returns:     ---
 677  *
 678  * Use:         Informs all admin connections of a warning.
 679  */
 680
 681 extern void a_warn(const char */*fmt*/, ...);
 682
 683 /* --- @a_notify@ --- *
 684  *
 685  * Arguments:   @const char *fmt@ = pointer to format string
 686  *              @...@ = other arguments
 687  *
 688  * Returns:     ---
 689  *
 690  * Use:         Sends a notification to interested admin connections.
 691  */
 692
 693 extern void a_notify(const char */*fmt*/, ...);
 694
 695 /* --- @a_create@ --- *
 696  *
 697  * Arguments:   @int fd_in, fd_out@ = file descriptors to use
 698  *              @unsigned f@ = initial flags to set
 699  *
 700  * Returns:     ---
 701  *
 702  * Use:         Creates a new admin connection.
 703  */
 704
 705 extern void a_create(int /*fd_in*/, int /*fd_out*/, unsigned /*f*/);
 706
 707 /* --- @a_quit@ --- *
 708  *
 709  * Arguments:   ---
 710  *
 711  * Returns:     ---
 712  *
 713  * Use:         Shuts things down nicely.
 714  */
 715
 716 extern void a_quit(void);
 717
 718 /* --- @a_daemon@ --- *
 719  *
 720  * Arguments:   ---
 721  *
 722  * Returns:     ---
 723  *
 724  * Use:         Informs the admin module that it's a daemon.
 725  */
 726
 727 extern void a_daemon(void);
 728
 729 /* --- @a_init@ --- *
 730  *
 731  * Arguments:   @const char *sock@ = socket name to create
 732  *
 733  * Returns:     ---
 734  *
 735  * Use:         Creates the admin listening socket.
 736  */
 737
 738 extern void a_init(const char */*sock*/);
 739
 740 /*----- Peer management ---------------------------------------------------*/
 741
 742 /* --- @p_txstart@ --- *
 743  *
 744  * Arguments:   @peer *p@ = pointer to peer block
 745  *              @unsigned msg@ = message type code
 746  *
 747  * Returns:     A pointer to a buffer to write to.
 748  *
 749  * Use:         Starts sending to a peer.  Only one send can happen at a
 750  *              time.
 751  */
 752
 753 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
 754
 755 /* --- @p_txend@ --- *
 756  *
 757  * Arguments:   @peer *p@ = pointer to peer block
 758  *
 759  * Returns:     ---
 760  *
 761  * Use:         Sends a packet to the peer.
 762  */
 763
 764 extern void p_txend(peer */*p*/);
 765
 766 /* --- @p_pingsend@ --- *
 767  *
 768  * Arguments:   @peer *p@ = destination peer
 769  *              @ping *pg@ = structure to fill in
 770  *              @unsigned type@ = message type
 771  *              @unsigned long timeout@ = how long to wait before giving up
 772  *              @void (*func)(int, void *)@ = callback function
 773  *              @void *arg@ = argument for callback
 774  *
 775  * Returns:     Zero if successful, nonzero if it failed.
 776  *
 777  * Use:         Sends a ping to a peer.  Call @func@ with a nonzero argument
 778  *              if we get an answer within the timeout, or zero if no answer.
 779  */
 780
 781 extern int p_pingsend(peer */*p*/, ping */*pg*/, unsigned /*type*/,
 782                       unsigned long /*timeout*/,
 783                       void (*/*func*/)(int, void *), void */*arg*/);
 784
 785 /* --- @p_pingdone@ --- *
 786  *
 787  * Arguments:   @ping *p@ = ping structure
 788  *              @int rc@ = return code to pass on
 789  *
 790  * Returns:     ---
 791  *
 792  * Use:         Disposes of a ping structure, maybe sending a notification.
 793  */
 794
 795 extern void p_pingdone(ping */*p*/, int /*rc*/);
 796
 797 /* --- @p_tun@ --- *
 798  *
 799  * Arguments:   @peer *p@ = pointer to peer block
 800  *              @buf *b@ = buffer containing incoming packet
 801  *
 802  * Returns:     ---
 803  *
 804  * Use:         Handles a packet which needs to be sent to a peer.
 805  */
 806
 807 extern void p_tun(peer */*p*/, buf */*b*/);
 808
 809 /* --- @p_interval@ --- *
 810  *
 811  * Arguments:   ---
 812  *
 813  * Returns:     ---
 814  *
 815  * Use:         Called periodically to do tidying.
 816  */
 817
 818 extern void p_interval(void);
 819
 820 /* --- @p_stats@ --- *
 821  *
 822  * Arguments:   @peer *p@ = pointer to a peer block
 823  *
 824  * Returns:     A pointer to the peer's statistics.
 825  */
 826
 827 extern stats *p_stats(peer */*p*/);
 828
 829 /* --- @p_ifname@ --- *
 830  *
 831  * Arguments:   @peer *p@ = pointer to a peer block
 832  *
 833  * Returns:     A pointer to the peer's interface name.
 834  */
 835
 836 extern const char *p_ifname(peer */*p*/);
 837
 838 /* --- @p_addr@ --- *
 839  *
 840  * Arguments:   @peer *p@ = pointer to a peer block
 841  *
 842  * Returns:     A pointer to the peer's address.
 843  */
 844
 845 extern const addr *p_addr(peer */*p*/);
 846
 847 /* --- @p_init@ --- *
 848  *
 849  * Arguments:   @struct in_addr addr@ = address to bind to
 850  *              @unsigned port@ = port number to listen to
 851  *
 852  * Returns:     ---
 853  *
 854  * Use:         Initializes the peer system; creates the socket.
 855  */
 856
 857 extern void p_init(struct in_addr /*addr*/, unsigned /*port*/);
 858
 859 /* --- @p_port@ --- *
 860  *
 861  * Arguments:   ---
 862  *
 863  * Returns:     Port number used for socket.
 864  */
 865
 866 unsigned p_port(void);
 867
 868 /* --- @p_create@ --- *
 869  *
 870  * Arguments:   @peerspec *spec@ = information about this peer
 871  *
 872  * Returns:     Pointer to the peer block, or null if it failed.
 873  *
 874  * Use:         Creates a new named peer block.  No peer is actually attached
 875  *              by this point.
 876  */
 877
 878 extern peer *p_create(peerspec */*spec*/);
 879
 880 /* --- @p_name@ --- *
 881  *
 882  * Arguments:   @peer *p@ = pointer to a peer block
 883  *
 884  * Returns:     A pointer to the peer's name.
 885  */
 886
 887 extern const char *p_name(peer */*p*/);
 888
 889 /* --- @p_find@ --- *
 890  *
 891  * Arguments:   @const char *name@ = name to look up
 892  *
 893  * Returns:     Pointer to the peer block, or null if not found.
 894  *
 895  * Use:         Finds a peer by name.
 896  */
 897
 898 extern peer *p_find(const char */*name*/);
 899
 900 /* --- @p_destroy@ --- *
 901  *
 902  * Arguments:   @peer *p@ = pointer to a peer
 903  *
 904  * Returns:     ---
 905  *
 906  * Use:         Destroys a peer.
 907  */
 908
 909 extern void p_destroy(peer */*p*/);
 910
 911 /* --- @p_first@, @p_next@ --- *
 912  *
 913  * Arguments:   @peer *p@ = a peer block
 914  *
 915  * Returns:     @peer_first@ returns the first peer in some ordering;
 916  *              @peer_next@ returns the peer following a given one in the
 917  *              same ordering.  Null is returned for the end of the list.
 918  */
 919
 920 extern peer *p_first(void);
 921 extern peer *p_next(peer */*p*/);
 922
 923 /*----- Tunnel drivers ----------------------------------------------------*/
 924
 925 #ifdef TUN_LINUX
 926   extern const tunnel_ops tun_linux;
 927 #endif
 928
 929 #ifdef TUN_UNET
 930   extern const tunnel_ops tun_unet;
 931 #endif
 932
 933 #ifdef TUN_BSD
 934   extern const tunnel_ops tun_bsd;
 935 #endif
 936
 937 extern const tunnel_ops tun_slip;
 938
 939 /*----- Other handy utilities ---------------------------------------------*/
 940
 941 /* --- @mpstr@ --- *
 942  *
 943  * Arguments:   @mp *m@ = a multiprecision integer
 944  *
 945  * Returns:     A pointer to the integer's textual representation.
 946  *
 947  * Use:         Converts a multiprecision integer to a string.  Corrupts
 948  *              @buf_t@.
 949  */
 950
 951 extern const char *mpstr(mp */*m*/);
 952
 953 /* --- @gestr@ --- *
 954  *
 955  * Arguments:   @group *g@ = a group
 956  *              @ge *x@ = a group element
 957  *
 958  * Returns:     A pointer to the element's textual representation.
 959  *
 960  * Use:         Converts a group element to a string.  Corrupts
 961  *              @buf_t@.
 962  */
 963
 964 extern const char *gestr(group */*g*/, ge */*x*/);
 965
 966 /* --- @timestr@ --- *
 967  *
 968  * Arguments:   @time_t t@ = a time to convert
 969  *
 970  * Returns:     A pointer to a textual representation of the time.
 971  *
 972  * Use:         Converts a time to a textual representation.  Corrupts
 973  *              @buf_t@.
 974  */
 975
 976 extern const char *timestr(time_t /*t*/);
 977
 978 /* --- @mystrieq@ --- *
 979  *
 980  * Arguments:   @const char *x, *y@ = two strings
 981  *
 982  * Returns:     True if @x@ and @y are equal, up to case.
 983  */
 984
 985 extern int mystrieq(const char */*x*/, const char */*y*/);
 986
 987 /*----- That's all, folks -------------------------------------------------*/
 988
 989 #ifdef __cplusplus
 990   }
 991 #endif
 992
 993 #endif