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