3 * $Id: tripe.h,v 1.13 2003/04/06 10:26:35 mdw Exp $
5 * Main header file for TrIPE
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.13 2003/04/06 10:26:35 mdw
33 * Report peer name on decrypt errors.
35 * Revision 1.12 2003/04/06 10:25:17 mdw
36 * Support Linux TUN/TAP device. Fix some bugs.
38 * Revision 1.11 2002/01/13 14:57:42 mdw
41 * Revision 1.10 2002/01/13 14:54:58 mdw
44 * Revision 1.9 2001/06/22 19:40:36 mdw
45 * Support expiry of other peers' public keys.
47 * Revision 1.8 2001/06/19 22:10:57 mdw
48 * Some more constants for the algorithms. Document the packet format
49 * change for non-malleability. Moved @buf@ definitions to separate header
52 * Revision 1.7 2001/03/03 12:07:08 mdw
53 * Rename word get and put functions now that there's 16-bit support.
55 * Revision 1.6 2001/02/19 19:11:09 mdw
56 * Output buffering on admin connections.
58 * Revision 1.5 2001/02/16 21:41:43 mdw
59 * Major changes. See source files for details.
61 * Revision 1.4 2001/02/05 19:56:37 mdw
62 * Sequence number protection, and BSD tunnels.
64 * Revision 1.3 2001/02/04 01:17:55 mdw
65 * Create a configuration header file to tidy up command lines.
67 * Revision 1.2 2001/02/03 22:40:29 mdw
68 * Put timer information into the entropy pool when packets are received
69 * and on similar events. Reseed the generator on the interval timer.
71 * Revision 1.1 2001/02/03 20:26:37 mdw
83 /*----- Header files ------------------------------------------------------*/
98 #include <sys/types.h>
102 #include <sys/stat.h>
104 #include <sys/socket.h>
106 #include <netinet/in.h>
107 #include <arpa/inet.h>
110 #if TUN_TYPE == TUN_LINUX
111 # include <linux/if.h>
112 # include <linux/if_tun.h>
118 #include <mLib/alloc.h>
119 #include <mLib/arena.h>
120 #include <mLib/bres.h>
121 #include <mLib/dstr.h>
122 #include <mLib/env.h>
123 #include <mLib/fdflags.h>
124 #include <mLib/fwatch.h>
125 #include <mLib/mdwopt.h>
126 #include <mLib/quis.h>
127 #include <mLib/report.h>
128 #include <mLib/sel.h>
129 #include <mLib/selbuf.h>
130 #include <mLib/sig.h>
131 #include <mLib/str.h>
132 #include <mLib/sub.h>
133 #include <mLib/trace.h>
135 #include <catacomb/gcipher.h>
136 #include <catacomb/gmac.h>
137 #include <catacomb/grand.h>
138 #include <catacomb/key.h>
139 #include <catacomb/paranoia.h>
141 #include <catacomb/noise.h>
142 #include <catacomb/rand.h>
144 #include <catacomb/mp.h>
145 #include <catacomb/mpmont.h>
146 #include <catacomb/mprand.h>
147 #include <catacomb/dh.h>
154 /*----- Magic numbers -----------------------------------------------------*/
156 /* --- Tunnel types --- */
163 /* --- Trace flags --- */
171 #define T_KEYEXCH 64u
172 #define T_KEYMGMT 128u
178 #define SEC(n) (n##u)
179 #define MIN(n) (n##u * 60u)
180 #define MEG(n) (n##ul * 1024ul * 1024ul)
182 /* --- Other things --- */
184 #define PKBUFSZ 65536
186 /*----- TrIPE protocol ----------------------------------------------------*/
188 /* --- TrIPE message format --- *
190 * A packet begins with a single-byte message type. The top four bits are a
191 * category code used to send the message to the right general place in the
192 * code; the bottom bits identify the actual message type.
195 #define MSG_CATMASK 0xf0
196 #define MSG_TYPEMASK 0x0f
198 /* --- Encrypted message packets --- *
200 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
201 * message content is a symmetric-encrypted block (see below). Reception of
202 * a packet encrypted under a new key implicitly permits that key to be used
203 * to send further packets.
205 * The only packet type accepted is zero.
207 * Packets may be encrypted under any live keyset, but should use the most
211 #define MSG_PACKET 0x00
213 /* --- Key exchange packets --- */
215 #define MSG_KEYEXCH 0x10
217 #define KX_PRECHAL 0u
222 #define KX_SWITCHOK 5u
225 /* --- Symmetric encryption and keysets --- *
227 * Packets consist of an 80-bit MAC, a 32-bit sequence number, and the
230 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
231 * stealing (as described in [Schneier]. The initialization vector is
232 * selected randomly, and prepended to the actual ciphertext.
234 * The MAC is computed using the HMAC construction with RIPEMD160 over the
235 * sequence number and the ciphertext (with IV); the first 80 bits of the
236 * output are used. (This is the minimum allowed by the draft FIPS for HMAC,
237 * and the recommended truncation.)
239 * A keyset consists of
241 * * an integrity (MAC) key;
242 * * a confidentiality (encryption) key; and
243 * * a sequence numbering space
245 * in each direction. The packets sent by a host encrypted under a
246 * particular keyset are assigned consecutive sequence numbers starting from
247 * zero. The receiving host must ensure that it only accepts each packet at
248 * most once. It should maintain a window of sequence numbers: packets with
249 * numbers beyond the end of the window are accepted and cause the window to
250 * be advanced; packets with numbers before the start of the window are
251 * rejected; packets with numbers which appear within the window are accepted
252 * only if the number has not been seen before.
254 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
255 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
256 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
257 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
261 /*----- Cipher selections -------------------------------------------------*/
263 #include <catacomb/blowfish.h>
264 #include <catacomb/blowfish-cbc.h>
265 #include <catacomb/blowfish-counter.h>
266 #include <catacomb/rmd160.h>
267 #include <catacomb/rmd160-hmac.h>
269 #define CIPHER (&blowfish_cbc)
270 #define MAC (&rmd160_hmac)
272 #define HASH_CTX rmd160_ctx
273 #define HASH_INIT rmd160_init
274 #define HASH rmd160_hash
275 #define HASH_STRING(c, s) HASH((c), s, sizeof(s))
276 #define HASH_DONE rmd160_done
277 #define HASHSZ RMD160_HASHSZ
279 #define MGF_CTX blowfish_counterctx
280 #define MGF_INIT blowfish_counterinit
281 #define MGF_CRYPT blowfish_counterencrypt
284 #define IVSZ BLOWFISH_BLKSZ
287 /*----- Data structures ---------------------------------------------------*/
289 /* --- Socket addresses --- *
291 * A magic union of supported socket addresses.
296 struct sockaddr_in sin;
299 /* --- A symmetric keyset --- *
301 * A keyset contains a set of symmetric keys for encrypting and decrypting
302 * packets. Keysets are stored in a list, sorted in reverse order of
303 * creation, so that the most recent keyset (the one most likely to be used)
306 * Each keyset has a time limit and a data limit. The keyset is destroyed
307 * when either it has existed for too long, or it has been used to encrypt
308 * too much data. New key exchanges are triggered when keys are close to
312 typedef struct keyset {
313 struct keyset *next; /* Next active keyset in the list */
314 unsigned ref; /* Reference count for keyset */
315 struct peer *p; /* Pointer to peer structure */
316 time_t t_exp; /* Expiry time for this keyset */
317 unsigned long sz_exp; /* Data limit for the keyset */
318 T( unsigned seq; ) /* Sequence number for tracing */
319 unsigned f; /* Various useful flags */
320 gcipher *cin, *cout; /* Keyset ciphers for encryption */
321 gmac *min, *mout; /* Keyset MACs for integrity */
322 uint32 oseq; /* Outbound sequence number */
323 uint32 iseq, iwin; /* Inbound sequence number */
326 #define KS_SEQWINSZ 32 /* Bits in sequence number window */
328 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
329 #define KSF_LINK 2u /* Key is in a linked list */
331 /* --- Key exchange --- *
333 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
334 * Protocol has a number of desirable features (e.g., perfect forward
335 * secrecy, and zero-knowledge authentication) which make it attractive for
336 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
343 typedef struct kxchal {
344 struct keyexch *kx; /* Pointer back to key exchange */
345 mp *c; /* Responder's challenge */
346 mp *r; /* My reply to the challenge */
347 keyset *ks; /* Pointer to temporary keyset */
348 unsigned f; /* Various useful flags */
349 sel_timer t; /* Response timer for challenge */
350 octet hc[HASHSZ]; /* Hash of his challenge */
351 mp *ck; /* The check value */
352 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
353 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
354 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
355 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
358 typedef struct keyexch {
359 struct peer *p; /* Pointer back to the peer */
360 keyset **ks; /* Peer's list of keysets */
361 unsigned f; /* Various useful flags */
362 unsigned s; /* Current state in exchange */
363 sel_timer t; /* Timer for next exchange */
364 dh_pub kpub; /* Peer's public key */
365 time_t texp_kpub; /* Expiry time for public key */
366 mp *alpha; /* My temporary secret */
367 mp *c; /* My challenge */
368 mp *rx; /* The expected response */
369 unsigned nr; /* Number of extant responses */
370 time_t t_valid; /* When this exchange goes bad */
371 octet hc[HASHSZ]; /* Hash of my challenge */
372 kxchal *r[KX_NCHAL]; /* Array of challenges */
375 #define KXF_TIMER 1u /* Waiting for a timer to go off */
376 #define KXF_DEAD 2u /* The key-exchanger isn't up */
377 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
380 KXS_DEAD, /* Uninitialized state (magical) */
381 KXS_CHAL, /* Main answer-challenges state */
382 KXS_COMMIT, /* Committed: send switch request */
383 KXS_SWITCH /* Switched: send confirmation */
386 /* --- Tunnel structure --- *
388 * Used to maintain system-specific information about the tunnel interface.
391 typedef struct tunnel {
392 #if TUN_TYPE == TUN_UNET
393 sel_file f; /* Selector for Usernet device */
394 struct peer *p; /* Pointer to my peer */
395 #elif TUN_TYPE == TUN_LINUX
396 sel_file f; /* Selector for TUN/TAP device */
397 struct peer *p; /* Pointer to my peer */
398 char ifn[IFNAMSIZ]; /* Interface name buffer */
399 #elif TUN_TYPE == TUN_BSD
400 sel_file f; /* Selector for tunnel device */
401 struct peer *p; /* Pointer to my peer */
402 unsigned n; /* Number of my tunnel device */
404 # error "No support for this tunnel type"
408 /* --- Peer statistics --- *
410 * Contains various interesting and not-so-interesting statistics about a
411 * peer. This is updated by various parts of the code. The format of the
412 * structure isn't considered private, and @p_stats@ returns a pointer to the
413 * statistics block for a given peer.
416 typedef struct stats {
417 unsigned long sz_in, sz_out; /* Size of all data in and out */
418 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
419 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
420 time_t t_start, t_last; /* Time peer created, last recv */
421 unsigned long n_reject; /* Number of rejected packets */
422 unsigned long n_in, n_out; /* Number of packets in and out */
423 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
424 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
427 /* --- Peer structure --- *
429 * The main structure which glues everything else together.
432 typedef struct peer {
433 struct peer *next, *prev; /* Links to next and previous */
434 char *name; /* Name of this peer */
435 tunnel t; /* Tunnel for local packets */
436 keyset *ks; /* List head for keysets */
437 buf b; /* Buffer for sending packets */
438 addr peer; /* Peer socket address */
439 size_t sasz; /* Socket address size */
440 stats st; /* Statistics */
441 keyexch kx; /* Key exchange protocol block */
444 /* --- Admin structure --- */
446 #define OBUFSZ 16384u
448 typedef struct obuf {
449 struct obuf *next; /* Next buffer in list */
450 char *p_in, *p_out; /* Pointers into the buffer */
451 char buf[OBUFSZ]; /* The actual buffer */
454 typedef struct admin {
455 struct admin *next, *prev; /* Links to next and previous */
456 unsigned f; /* Various useful flags */
458 unsigned seq; /* Sequence number for tracing */
460 char *pname; /* Peer name to create */
461 char *paddr; /* Address string to resolve */
462 obuf *o_head, *o_tail; /* Output buffer list */
463 selbuf b; /* Line buffer for commands */
464 sel_file w; /* Selector for write buffering */
465 bres_client r; /* Background resolver task */
466 sel_timer t; /* Timer for resolver */
467 addr peer; /* Address to set */
468 size_t sasz; /* Size of the address */
471 #define AF_DEAD 1u /* Destroy this admin block */
472 #define AF_LOCK 2u /* Don't destroy it yet */
474 /*----- Global variables --------------------------------------------------*/
476 extern sel_state sel; /* Global I/O event state */
477 extern dh_priv kpriv; /* Our private key */
478 extern mpmont mg; /* Montgomery context for DH group */
479 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
482 extern const trace_opt tr_opts[]; /* Trace options array */
483 extern unsigned tr_flags; /* Trace options flags */
486 /*----- Other macros ------------------------------------------------------*/
488 #define TIMER noise_timer(RAND_GLOBAL)
490 /*----- Key management ----------------------------------------------------*/
492 /* --- @km_interval@ --- *
496 * Returns: Zero if OK, nonzero to force reloading of keys.
498 * Use: Called on the interval timer to perform various useful jobs.
501 extern int km_interval(void);
503 /* --- @km_init@ --- *
505 * Arguments: @const char *kr_priv@ = private keyring file
506 * @const char *kr_pub@ = public keyring file
507 * @const char *tag@ = tag to load
511 * Use: Initializes, and loads the private key.
514 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
515 const char */*tag*/);
517 /* --- @km_getpubkey@ --- *
519 * Arguments: @const char *tag@ = public key tag to load
520 * @dh_pub *kpub@ = where to put the public key
521 * @time_t *t_exp@ = where to put the expiry time
523 * Returns: Zero if OK, nonzero if it failed.
525 * Use: Fetches a public key from the keyring.
528 extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/,
531 /*----- Key exchange ------------------------------------------------------*/
533 /* --- @kx_start@ --- *
535 * Arguments: @keyexch *kx@ = pointer to key exchange context
539 * Use: Stimulates a key exchange. If a key exchage is in progress,
540 * a new challenge is sent (unless the quiet timer forbids
541 * this); if no exchange is in progress, one is commenced.
544 extern void kx_start(keyexch */*kx*/);
546 /* --- @kx_message@ --- *
548 * Arguments: @keyexch *kx@ = pointer to key exchange context
549 * @unsigned msg@ = the message code
550 * @buf *b@ = pointer to buffer containing the packet
554 * Use: Reads a packet containing key exchange messages and handles
558 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
560 /* --- @kx_free@ --- *
562 * Arguments: @keyexch *kx@ = pointer to key exchange context
566 * Use: Frees everything in a key exchange context.
569 extern void kx_free(keyexch */*kx*/);
571 /* --- @kx_newkeys@ --- *
573 * Arguments: @keyexch *kx@ = pointer to key exchange context
577 * Use: Informs the key exchange module that its keys may have
578 * changed. If fetching the new keys fails, the peer will be
579 * destroyed, we log messages and struggle along with the old
583 extern void kx_newkeys(keyexch */*kx*/);
585 /* --- @kx_init@ --- *
587 * Arguments: @keyexch *kx@ = pointer to key exchange context
588 * @peer *p@ = pointer to peer context
589 * @keyset **ks@ = pointer to keyset list
591 * Returns: Zero if OK, nonzero if it failed.
593 * Use: Initializes a key exchange module. The module currently
594 * contains no keys, and will attempt to initiate a key
598 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
600 /*----- Keysets and symmetric cryptography --------------------------------*/
602 /* --- @ks_drop@ --- *
604 * Arguments: @keyset *ks@ = pointer to a keyset
608 * Use: Decrements a keyset's reference counter. If the counter hits
609 * zero, the keyset is freed.
612 extern void ks_drop(keyset */*ks*/);
614 /* --- @ks_gen@ --- *
616 * Arguments: @const void *k@ = pointer to key material
617 * @size_t x, y, z@ = offsets into key material (see below)
618 * @peer *p@ = pointer to peer information
620 * Returns: A pointer to the new keyset.
622 * Use: Derives a new keyset from the given key material. The
623 * offsets @x@, @y@ and @z@ separate the key material into three
624 * parts. Between the @k@ and @k + x@ is `my' contribution to
625 * the key material; between @k + x@ and @k + y@ is `your'
626 * contribution; and between @k + y@ and @k + z@ is a shared
627 * value we made together. These are used to construct two
628 * pairs of symmetric keys. Each pair consists of an encryption
629 * key and a message authentication key. One pair is used for
630 * outgoing messages, the other for incoming messages.
632 * The new key is marked so that it won't be selected for output
633 * by @ksl_encrypt@. You can still encrypt data with it by
634 * calling @ks_encrypt@ directly.
637 extern keyset *ks_gen(const void */*k*/,
638 size_t /*x*/, size_t /*y*/, size_t /*z*/,
641 /* --- @ks_tregen@ --- *
643 * Arguments: @keyset *ks@ = pointer to a keyset
645 * Returns: The time at which moves ought to be made to replace this key.
648 extern time_t ks_tregen(keyset */*ks*/);
650 /* --- @ks_activate@ --- *
652 * Arguments: @keyset *ks@ = pointer to a keyset
656 * Use: Activates a keyset, so that it can be used for encrypting
660 extern void ks_activate(keyset */*ks*/);
662 /* --- @ks_encrypt@ --- *
664 * Arguments: @keyset *ks@ = pointer to a keyset
665 * @buf *b@ = pointer to input buffer
666 * @buf *bb@ = pointer to output buffer
668 * Returns: Zero if OK, nonzero if the key needs replacing. If the
669 * encryption failed, the output buffer is broken and zero is
672 * Use: Encrypts a block of data using the key. Note that the `key
673 * ought to be replaced' notification is only ever given once
674 * for each key. Also note that this call forces a keyset to be
675 * used even if it's marked as not for data output.
678 extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
680 /* --- @ks_decrypt@ --- *
682 * Arguments: @keyset *ks@ = pointer to a keyset
683 * @buf *b@ = pointer to an input buffer
684 * @buf *bb@ = pointer to an output buffer
686 * Returns: Zero on success, or nonzero if there was some problem.
688 * Use: Attempts to decrypt a message using a given key. Note that
689 * requesting decryption with a key directly won't clear a
690 * marking that it's not for encryption.
693 extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
695 /* --- @ksl_free@ --- *
697 * Arguments: @keyset **ksroot@ = pointer to keyset list head
701 * Use: Frees (releases references to) all of the keys in a keyset.
704 extern void ksl_free(keyset **/*ksroot*/);
706 /* --- @ksl_link@ --- *
708 * Arguments: @keyset **ksroot@ = pointer to keyset list head
709 * @keyset *ks@ = pointer to a keyset
713 * Use: Links a keyset into a list. A keyset can only be on one list
714 * at a time. Bad things happen otherwise.
717 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
719 /* --- @ksl_prune@ --- *
721 * Arguments: @keyset **ksroot@ = pointer to keyset list head
725 * Use: Prunes the keyset list by removing keys which mustn't be used
729 extern void ksl_prune(keyset **/*ksroot*/);
731 /* --- @ksl_encrypt@ --- *
733 * Arguments: @keyset **ksroot@ = pointer to keyset list head
734 * @buf *b@ = pointer to input buffer
735 * @buf *bb@ = pointer to output buffer
737 * Returns: Nonzero if a new key is needed.
739 * Use: Encrypts a packet.
742 extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
744 /* --- @ksl_decrypt@ --- *
746 * Arguments: @keyset **ksroot@ = pointer to keyset list head
747 * @buf *b@ = pointer to input buffer
748 * @buf *bb@ = pointer to output buffer
750 * Returns: Nonzero if the packet couldn't be decrypted.
752 * Use: Decrypts a packet.
755 extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
757 /*----- Administration interface ------------------------------------------*/
759 /* --- @a_warn@ --- *
761 * Arguments: @const char *fmt@ = pointer to format string
762 * @...@ = other arguments
766 * Use: Informs all admin connections of a warning.
769 extern void a_warn(const char */*fmt*/, ...);
771 /* --- @a_create@ --- *
773 * Arguments: @int fd_in, fd_out@ = file descriptors to use
777 * Use: Creates a new admin connection.
780 extern void a_create(int /*fd_in*/, int /*fd_out*/);
782 /* --- @a_quit@ --- *
788 * Use: Shuts things down nicely.
791 extern void a_quit(void);
793 /* --- @a_daemon@ --- *
799 * Use: Informs the admin module that it's a daemon.
802 extern void a_daemon(void);
804 /* --- @a_init@ --- *
806 * Arguments: @const char *sock@ = socket name to create
810 * Use: Creates the admin listening socket.
813 extern void a_init(const char */*sock*/);
815 /*----- Peer management ---------------------------------------------------*/
817 /* --- @p_txstart@ --- *
819 * Arguments: @peer *p@ = pointer to peer block
820 * @unsigned msg@ = message type code
822 * Returns: A pointer to a buffer to write to.
824 * Use: Starts sending to a peer. Only one send can happen at a
828 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
830 /* --- @p_txend@ --- *
832 * Arguments: @peer *p@ = pointer to peer block
836 * Use: Sends a packet to the peer.
839 extern void p_txend(peer */*p*/);
843 * Arguments: @peer *p@ = pointer to peer block
844 * @buf *b@ = buffer containing incoming packet
848 * Use: Handles a packet which needs to be sent to a peer.
851 extern void p_tun(peer */*p*/, buf */*b*/);
853 /* --- @p_interval@ --- *
859 * Use: Called periodically to do tidying.
862 extern void p_interval(void);
864 /* --- @p_stats@ --- *
866 * Arguments: @peer *p@ = pointer to a peer block
868 * Returns: A pointer to the peer's statistics.
871 extern stats *p_stats(peer */*p*/);
873 /* --- @p_ifname@ --- *
875 * Arguments: @peer *p@ = pointer to a peer block
877 * Returns: A pointer to the peer's interface name.
880 extern const char *p_ifname(peer */*p*/);
882 /* --- @p_addr@ --- *
884 * Arguments: @peer *p@ = pointer to a peer block
886 * Returns: A pointer to the peer's address.
889 extern const addr *p_addr(peer */*p*/);
891 /* --- @p_init@ --- *
893 * Arguments: @unsigned port@ = port number to listen to
897 * Use: Initializes the peer system; creates the socket.
900 extern void p_init(unsigned /*port*/);
902 /* --- @p_port@ --- *
906 * Returns: Port number used for socket.
909 unsigned p_port(void);
911 /* --- @p_create@ --- *
913 * Arguments: @const char *name@ = name for this peer
914 * @struct sockaddr *sa@ = socket address of peer
915 * @size_t sz@ = size of socket address
917 * Returns: Pointer to the peer block, or null if it failed.
919 * Use: Creates a new named peer block. No peer is actually attached
923 extern peer *p_create(const char */*name*/,
924 struct sockaddr */*sa*/, size_t /*sz*/);
926 /* --- @p_name@ --- *
928 * Arguments: @peer *p@ = pointer to a peer block
930 * Returns: A pointer to the peer's name.
933 extern const char *p_name(peer */*p*/);
935 /* --- @p_find@ --- *
937 * Arguments: @const char *name@ = name to look up
939 * Returns: Pointer to the peer block, or null if not found.
941 * Use: Finds a peer by name.
944 extern peer *p_find(const char */*name*/);
946 /* --- @p_destroy@ --- *
948 * Arguments: @peer *p@ = pointer to a peer
952 * Use: Destroys a peer.
955 extern void p_destroy(peer */*p*/);
957 /* --- @p_first@, @p_next@ --- *
959 * Arguments: @peer *p@ = a peer block
961 * Returns: @peer_first@ returns the first peer in some ordering;
962 * @peer_next@ returns the peer following a given one in the
963 * same ordering. Null is returned for the end of the list.
966 extern peer *p_first(void);
967 extern peer *p_next(peer */*p*/);
969 /*----- Tunnel interface --------------------------------------------------*/
971 /* --- @tun_init@ --- *
977 * Use: Initializes the tunneling system. Maybe this will require
978 * opening file descriptors or something.
981 extern void tun_init(void);
983 /* --- @tun_create@ --- *
985 * Arguments: @tunnel *t@ = pointer to tunnel block
986 * @peer *p@ = pointer to peer block
988 * Returns: Zero if it worked, nonzero on failure.
990 * Use: Initializes a new tunnel.
993 extern int tun_create(tunnel */*t*/, peer */*p*/);
995 /* --- @tun_ifname@ --- *
997 * Arguments: @tunnel *t@ = pointer to tunnel block
999 * Returns: A pointer to the tunnel's interface name.
1002 extern const char *tun_ifname(tunnel */*t*/);
1004 /* --- @tun_inject@ --- *
1006 * Arguments: @tunnel *t@ = pointer to tunnel block
1007 * @buf *b@ = buffer to send
1011 * Use: Injects a packet into the local network stack.
1014 extern void tun_inject(tunnel */*t*/, buf */*b*/);
1016 /* --- @tun_destroy@ --- *
1018 * Arguments: @tunnel *t@ = pointer to tunnel block
1022 * Use: Destroys a tunnel.
1025 extern void tun_destroy(tunnel */*t*/);
1027 /*----- Other handy utilities ---------------------------------------------*/
1029 /* --- @mpstr@ --- *
1031 * Arguments: @mp *m@ = a multiprecision integer
1033 * Returns: A pointer to the integer's textual representation.
1035 * Use: Converts a multiprecision integer to a string. Corrupts
1039 extern const char *mpstr(mp */*m*/);
1041 /* --- @timestr@ --- *
1043 * Arguments: @time_t t@ = a time to convert
1045 * Returns: A pointer to a textual representation of the time.
1047 * Use: Converts a time to a textual representation. Corrupts
1051 extern const char *timestr(time_t /*t*/);
1053 /*----- That's all, folks -------------------------------------------------*/