3 * $Id: tripe.h,v 1.10 2002/01/13 14:54:58 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 1.10 2002/01/13 14:54:58 mdw
35 * Revision 1.9 2001/06/22 19:40:36 mdw
36 * Support expiry of other peers' public keys.
38 * Revision 1.8 2001/06/19 22:10:57 mdw
39 * Some more constants for the algorithms. Document the packet format
40 * change for non-malleability. Moved @buf@ definitions to separate header
43 * Revision 1.7 2001/03/03 12:07:08 mdw
44 * Rename word get and put functions now that there's 16-bit support.
46 * Revision 1.6 2001/02/19 19:11:09 mdw
47 * Output buffering on admin connections.
49 * Revision 1.5 2001/02/16 21:41:43 mdw
50 * Major changes. See source files for details.
52 * Revision 1.4 2001/02/05 19:56:37 mdw
53 * Sequence number protection, and BSD tunnels.
55 * Revision 1.3 2001/02/04 01:17:55 mdw
56 * Create a configuration header file to tidy up command lines.
58 * Revision 1.2 2001/02/03 22:40:29 mdw
59 * Put timer information into the entropy pool when packets are received
60 * and on similar events. Reseed the generator on the interval timer.
62 * Revision 1.1 2001/02/03 20:26:37 mdw
74 /*----- Header files ------------------------------------------------------*/
89 #include <sys/types.h>
95 #include <sys/socket.h>
97 #include <netinet/in.h>
98 #include <arpa/inet.h>
104 #include <mLib/alloc.h>
105 #include <mLib/arena.h>
106 #include <mLib/bres.h>
107 #include <mLib/dstr.h>
108 #include <mLib/env.h>
109 #include <mLib/fdflags.h>
110 #include <mLib/fwatch.h>
111 #include <mLib/mdwopt.h>
112 #include <mLib/quis.h>
113 #include <mLib/report.h>
114 #include <mLib/sel.h>
115 #include <mLib/selbuf.h>
116 #include <mLib/sig.h>
117 #include <mLib/str.h>
118 #include <mLib/sub.h>
119 #include <mLib/trace.h>
121 #include <catacomb/gcipher.h>
122 #include <catacomb/gmac.h>
123 #include <catacomb/grand.h>
124 #include <catacomb/key.h>
125 #include <catacomb/paranoia.h>
127 #include <catacomb/noise.h>
128 #include <catacomb/rand.h>
130 #include <catacomb/mp.h>
131 #include <catacomb/mpmont.h>
132 #include <catacomb/mprand.h>
133 #include <catacomb/dh.h>
140 /*----- Magic numbers -----------------------------------------------------*/
142 /* --- Tunnel types --- */
148 /* --- Trace flags --- */
156 #define T_KEYEXCH 64u
157 #define T_KEYMGMT 128u
163 #define SEC(n) (n##u)
164 #define MIN(n) (n##u * 60u)
165 #define MEG(n) (n##ul * 1024ul * 1024ul)
167 /* --- Other things --- */
169 #define PKBUFSZ 65536
171 /*----- TrIPE protocol ----------------------------------------------------*/
173 /* --- TrIPE message format --- *
175 * A packet begins with a single-byte message type. The top four bits are a
176 * category code used to send the message to the right general place in the
177 * code; the bottom bits identify the actual message type.
180 #define MSG_CATMASK 0xf0
181 #define MSG_TYPEMASK 0x0f
183 /* --- Encrypted message packets --- *
185 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
186 * message content is a symmetric-encrypted block (see below). Reception of
187 * a packet encrypted under a new key implicitly permits that key to be used
188 * to send further packets.
190 * The only packet type accepted is zero.
192 * Packets may be encrypted under any live keyset, but should use the most
196 #define MSG_PACKET 0x00
198 /* --- Key exchange packets --- */
200 #define MSG_KEYEXCH 0x10
202 #define KX_PRECHAL 0u
207 #define KX_SWITCHOK 5u
210 /* --- Symmetric encryption and keysets --- *
212 * Packets consist of an 80-bit MAC, a 32-bit sequence number, and the
215 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
216 * stealing (as described in [Schneier]. The initialization vector is
217 * selected randomly, and prepended to the actual ciphertext.
219 * The MAC is computed using the HMAC construction with RIPEMD160 over the
220 * sequence number and the ciphertext (with iV); the first 80 bits of the
221 * output are used. (This is the minimum allowed by the draft FIPS for HMAC,
222 * and the recommended truncation.)
224 * A keyset consists of
226 * * an integrity (MAC) key;
227 * * a confidentiality (encryption) key; and
228 * * a sequence numbering space
230 * in each direction. The packets sent by a host encrypted under a
231 * particular keyset are assigned consecutive sequence numbers starting from
232 * zero. The receiving host must ensure that it only accepts each packet at
233 * most once. It should maintain a window of sequence numbers: packets with
234 * numbers beyond the end of the window are accepted and cause the window to
235 * be advanced; packets with numbers before the start of the window are
236 * rejected; packets with numbers which appear within the window are accepted
237 * only if the number has not been seen before.
239 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
240 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
241 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
242 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
246 /*----- Cipher selections -------------------------------------------------*/
248 #include <catacomb/blowfish.h>
249 #include <catacomb/blowfish-cbc.h>
250 #include <catacomb/blowfish-counter.h>
251 #include <catacomb/rmd160.h>
252 #include <catacomb/rmd160-hmac.h>
254 #define CIPHER (&blowfish_cbc)
255 #define MAC (&rmd160_hmac)
257 #define HASH_CTX rmd160_ctx
258 #define HASH_INIT rmd160_init
259 #define HASH rmd160_hash
260 #define HASH_STRING(c, s) HASH((c), s, sizeof(s))
261 #define HASH_DONE rmd160_done
262 #define HASHSZ RMD160_HASHSZ
264 #define MGF_CTX blowfish_counterctx
265 #define MGF_INIT blowfish_counterinit
266 #define MGF_CRYPT blowfish_counterencrypt
269 #define IVSZ BLOWFISH_BLKSZ
272 /*----- Data structures ---------------------------------------------------*/
274 /* --- Socket addresses --- *
276 * A magic union of supported socket addresses.
281 struct sockaddr_in sin;
284 /* --- A symmetric keyset --- *
286 * A keyset contains a set of symmetric keys for encrypting and decrypting
287 * packets. Keysets are stored in a list, sorted in reverse order of
288 * creation, so that the most recent keyset (the one most likely to be used)
291 * Each keyset has a time limit and a data limit. The keyset is destroyed
292 * when either it has existed for too long, or it has been used to encrypt
293 * too much data. New key exchanges are triggered when keys are close to
297 typedef struct keyset {
298 struct keyset *next; /* Next active keyset in the list */
299 unsigned ref; /* Reference count for keyset */
300 time_t t_exp; /* Expiry time for this keyset */
301 unsigned long sz_exp; /* Data limit for the keyset */
302 T( unsigned seq; ) /* Sequence number for tracing */
303 unsigned f; /* Various useful flags */
304 gcipher *cin, *cout; /* Keyset ciphers for encryption */
305 gmac *min, *mout; /* Keyset MACs for integrity */
306 uint32 oseq; /* Outbound sequence number */
307 uint32 iseq, iwin; /* Inbound sequence number */
310 #define KS_SEQWINSZ 32 /* Bits in sequence number window */
312 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
313 #define KSF_LINK 2u /* Key is in a linked list */
315 /* --- Key exchange --- *
317 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
318 * Protocol has a number of desirable features (e.g., perfect forward
319 * secrecy, and zero-knowledge authentication) which make it attractive for
320 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
327 typedef struct kxchal {
328 struct keyexch *kx; /* Pointer back to key exchange */
329 mp *c; /* Responder's challenge */
330 mp *r; /* My reply to the challenge */
331 keyset *ks; /* Pointer to temporary keyset */
332 unsigned f; /* Various useful flags */
333 sel_timer t; /* Response timer for challenge */
334 octet hc[HASHSZ]; /* Hash of his challenge */
335 mp *ck; /* The check value */
336 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
337 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
338 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
339 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
342 typedef struct keyexch {
343 struct peer *p; /* Pointer back to the peer */
344 keyset **ks; /* Peer's list of keysets */
345 unsigned f; /* Various useful flags */
346 unsigned s; /* Current state in exchange */
347 sel_timer t; /* Timer for next exchange */
348 dh_pub kpub; /* Peer's public key */
349 time_t texp_kpub; /* Expiry time for public key */
350 mp *alpha; /* My temporary secret */
351 mp *c; /* My challenge */
352 mp *rx; /* The expected response */
353 unsigned nr; /* Number of extant responses */
354 time_t t_valid; /* When this exchange goes bad */
355 octet hc[HASHSZ]; /* Hash of my challenge */
356 kxchal *r[KX_NCHAL]; /* Array of challenges */
359 #define KXF_TIMER 1u /* Waiting for a timer to go off */
360 #define KXF_DEAD 2u /* The key-exchanger isn't up */
361 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
364 KXS_DEAD, /* Uninitialized state (magical) */
365 KXS_CHAL, /* Main answer-challenges state */
366 KXS_COMMIT, /* Committed: send switch request */
367 KXS_SWITCH /* Switched: send confirmation */
370 /* --- Tunnel structure --- *
372 * Used to maintain system-specific information about the tunnel interface.
375 typedef struct tunnel {
376 #if TUN_TYPE == TUN_UNET
377 sel_file f; /* Selector for Usernet device */
378 struct peer *p; /* Pointer to my peer */
379 #elif TUN_TYPE == TUN_BSD
380 sel_file f; /* Selector for tunnel device */
381 struct peer *p; /* Pointer to my peer */
382 unsigned n; /* Number of my tunnel device */
384 # error "No support for this tunnel type"
388 /* --- Peer statistics --- *
390 * Contains various interesting and not-so-interesting statistics about a
391 * peer. This is updated by various parts of the code. The format of the
392 * structure isn't considered private, and @p_stats@ returns a pointer to the
393 * statistics block for a given peer.
396 typedef struct stats {
397 unsigned long sz_in, sz_out; /* Size of all data in and out */
398 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
399 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
400 time_t t_start, t_last; /* Time peer created, last recv */
401 unsigned long n_reject; /* Number of rejected packets */
402 unsigned long n_in, n_out; /* Number of packets in and out */
403 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
404 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
407 /* --- Peer structure --- *
409 * The main structure which glues everything else together.
412 typedef struct peer {
413 struct peer *next, *prev; /* Links to next and previous */
414 char *name; /* Name of this peer */
415 tunnel t; /* Tunnel for local packets */
416 keyset *ks; /* List head for keysets */
417 buf b; /* Buffer for sending packets */
418 addr peer; /* Peer socket address */
419 size_t sasz; /* Socket address size */
420 stats st; /* Statistics */
421 keyexch kx; /* Key exchange protocol block */
424 /* --- Admin structure --- */
426 #define OBUFSZ 16384u
428 typedef struct obuf {
429 struct obuf *next; /* Next buffer in list */
430 char *p_in, *p_out; /* Pointers into the buffer */
431 char buf[OBUFSZ]; /* The actual buffer */
434 typedef struct admin {
435 struct admin *next, *prev; /* Links to next and previous */
436 unsigned f; /* Various useful flags */
438 unsigned seq; /* Sequence number for tracing */
440 char *pname; /* Peer name to create */
441 char *paddr; /* Address string to resolve */
442 obuf *o_head, *o_tail; /* Output buffer list */
443 selbuf b; /* Line buffer for commands */
444 sel_file w; /* Selector for write buffering */
445 bres_client r; /* Background resolver task */
446 sel_timer t; /* Timer for resolver */
447 addr peer; /* Address to set */
448 size_t sasz; /* Size of the address */
451 #define AF_DEAD 1u /* Destroy this admin block */
452 #define AF_LOCK 2u /* Don't destroy it yet */
454 /*----- Global variables --------------------------------------------------*/
456 extern sel_state sel; /* Global I/O event state */
457 extern dh_priv kpriv; /* Our private key */
458 extern mpmont mg; /* Montgomery context for DH group */
459 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
462 extern const trace_opt tr_opts[]; /* Trace options array */
463 extern unsigned tr_flags; /* Trace options flags */
466 /*----- Other macros ------------------------------------------------------*/
468 #define TIMER noise_timer(RAND_GLOBAL)
470 /*----- Key management ----------------------------------------------------*/
472 /* --- @km_interval@ --- *
476 * Returns: Zero if OK, nonzero to force reloading of keys.
478 * Use: Called on the interval timer to perform various useful jobs.
481 extern int km_interval(void);
483 /* --- @km_init@ --- *
485 * Arguments: @const char *kr_priv@ = private keyring file
486 * @const char *kr_pub@ = public keyring file
487 * @const char *tag@ = tag to load
491 * Use: Initializes, and loads the private key.
494 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
495 const char */*tag*/);
497 /* --- @km_getpubkey@ --- *
499 * Arguments: @const char *tag@ = public key tag to load
500 * @dh_pub *kpub@ = where to put the public key
501 * @time_t *t_exp@ = where to put the expiry time
503 * Returns: Zero if OK, nonzero if it failed.
505 * Use: Fetches a public key from the keyring.
508 extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/,
511 /*----- Key exchange ------------------------------------------------------*/
513 /* --- @kx_start@ --- *
515 * Arguments: @keyexch *kx@ = pointer to key exchange context
519 * Use: Stimulates a key exchange. If a key exchage is in progress,
520 * a new challenge is sent (unless the quiet timer forbids
521 * this); if no exchange is in progress, one is commenced.
524 extern void kx_start(keyexch */*kx*/);
526 /* --- @kx_message@ --- *
528 * Arguments: @keyexch *kx@ = pointer to key exchange context
529 * @unsigned msg@ = the message code
530 * @buf *b@ = pointer to buffer containing the packet
534 * Use: Reads a packet containing key exchange messages and handles
538 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
540 /* --- @kx_free@ --- *
542 * Arguments: @keyexch *kx@ = pointer to key exchange context
546 * Use: Frees everything in a key exchange context.
549 extern void kx_free(keyexch */*kx*/);
551 /* --- @kx_newkeys@ --- *
553 * Arguments: @keyexch *kx@ = pointer to key exchange context
557 * Use: Informs the key exchange module that its keys may have
558 * changed. If fetching the new keys fails, the peer will be
559 * destroyed, we log messages and struggle along with the old
563 extern void kx_newkeys(keyexch */*kx*/);
565 /* --- @kx_init@ --- *
567 * Arguments: @keyexch *kx@ = pointer to key exchange context
568 * @peer *p@ = pointer to peer context
569 * @keyset **ks@ = pointer to keyset list
571 * Returns: Zero if OK, nonzero if it failed.
573 * Use: Initializes a key exchange module. The module currently
574 * contains no keys, and will attempt to initiate a key
578 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
580 /*----- Keysets and symmetric cryptography --------------------------------*/
582 /* --- @ks_drop@ --- *
584 * Arguments: @keyset *ks@ = pointer to a keyset
588 * Use: Decrements a keyset's reference counter. If the counter hits
589 * zero, the keyset is freed.
592 extern void ks_drop(keyset */*ks*/);
594 /* --- @ks_gen@ --- *
596 * Arguments: @const void *k@ = pointer to key material
597 * @size_t x, y, z@ = offsets into key material (see below)
599 * Returns: A pointer to the new keyset.
601 * Use: Derives a new keyset from the given key material. The
602 * offsets @x@, @y@ and @z@ separate the key material into three
603 * parts. Between the @k@ and @k + x@ is `my' contribution to
604 * the key material; between @k + x@ and @k + y@ is `your'
605 * contribution; and between @k + y@ and @k + z@ is a shared
606 * value we made together. These are used to construct two
607 * pairs of symmetric keys. Each pair consists of an encryption
608 * key and a message authentication key. One pair is used for
609 * outgoing messages, the other for incoming messages.
611 * The new key is marked so that it won't be selected for output
612 * by @ksl_encrypt@. You can still encrypt data with it by
613 * calling @ks_encrypt@ directly.
616 extern keyset *ks_gen(const void */*k*/,
617 size_t /*x*/, size_t /*y*/, size_t /*z*/);
619 /* --- @ks_tregen@ --- *
621 * Arguments: @keyset *ks@ = pointer to a keyset
623 * Returns: The time at which moves ought to be made to replace this key.
626 extern time_t ks_tregen(keyset */*ks*/);
628 /* --- @ks_activate@ --- *
630 * Arguments: @keyset *ks@ = pointer to a keyset
634 * Use: Activates a keyset, so that it can be used for encrypting
638 extern void ks_activate(keyset */*ks*/);
640 /* --- @ks_encrypt@ --- *
642 * Arguments: @keyset *ks@ = pointer to a keyset
643 * @buf *b@ = pointer to input buffer
644 * @buf *bb@ = pointer to output buffer
646 * Returns: Zero if OK, nonzero if the key needs replacing. If the
647 * encryption failed, the output buffer is broken and zero is
650 * Use: Encrypts a block of data using the key. Note that the `key
651 * ought to be replaced' notification is only ever given once
652 * for each key. Also note that this call forces a keyset to be
653 * used even if it's marked as not for data output.
656 extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
658 /* --- @ks_decrypt@ --- *
660 * Arguments: @keyset *ks@ = pointer to a keyset
661 * @buf *b@ = pointer to an input buffer
662 * @buf *bb@ = pointer to an output buffer
664 * Returns: Zero on success, or nonzero if there was some problem.
666 * Use: Attempts to decrypt a message using a given key. Note that
667 * requesting decryption with a key directly won't clear a
668 * marking that it's not for encryption.
671 extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
673 /* --- @ksl_free@ --- *
675 * Arguments: @keyset **ksroot@ = pointer to keyset list head
679 * Use: Frees (releases references to) all of the keys in a keyset.
682 extern void ksl_free(keyset **/*ksroot*/);
684 /* --- @ksl_link@ --- *
686 * Arguments: @keyset **ksroot@ = pointer to keyset list head
687 * @keyset *ks@ = pointer to a keyset
691 * Use: Links a keyset into a list. A keyset can only be on one list
692 * at a time. Bad things happen otherwise.
695 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
697 /* --- @ksl_prune@ --- *
699 * Arguments: @keyset **ksroot@ = pointer to keyset list head
703 * Use: Prunes the keyset list by removing keys which mustn't be used
707 extern void ksl_prune(keyset **/*ksroot*/);
709 /* --- @ksl_encrypt@ --- *
711 * Arguments: @keyset **ksroot@ = pointer to keyset list head
712 * @buf *b@ = pointer to input buffer
713 * @buf *bb@ = pointer to output buffer
715 * Returns: Nonzero if a new key is needed.
717 * Use: Encrypts a packet.
720 extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
722 /* --- @ksl_decrypt@ --- *
724 * Arguments: @keyset **ksroot@ = pointer to keyset list head
725 * @buf *b@ = pointer to input buffer
726 * @buf *bb@ = pointer to output buffer
728 * Returns: Nonzero if the packet couldn't be decrypted.
730 * Use: Decrypts a packet.
733 extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
735 /*----- Administration interface ------------------------------------------*/
737 /* --- @a_warn@ --- *
739 * Arguments: @const char *fmt@ = pointer to format string
740 * @...@ = other arguments
744 * Use: Informs all admin connections of a warning.
747 extern void a_warn(const char */*fmt*/, ...);
749 /* --- @a_create@ --- *
751 * Arguments: @int fd_in, fd_out@ = file descriptors to use
755 * Use: Creates a new admin connection.
758 extern void a_create(int /*fd_in*/, int /*fd_out*/);
760 /* --- @a_quit@ --- *
766 * Use: Shuts things down nicely.
769 extern void a_quit(void);
771 /* --- @a_daemon@ --- *
777 * Use: Informs the admin module that it's a daemon.
780 extern void a_daemon(void);
782 /* --- @a_init@ --- *
784 * Arguments: @const char *sock@ = socket name to create
788 * Use: Creates the admin listening socket.
791 extern void a_init(const char */*sock*/);
793 /*----- Peer management ---------------------------------------------------*/
795 /* --- @p_txstart@ --- *
797 * Arguments: @peer *p@ = pointer to peer block
798 * @unsigned msg@ = message type code
800 * Returns: A pointer to a buffer to write to.
802 * Use: Starts sending to a peer. Only one send can happen at a
806 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
808 /* --- @p_txend@ --- *
810 * Arguments: @peer *p@ = pointer to peer block
814 * Use: Sends a packet to the peer.
817 extern void p_txend(peer */*p*/);
821 * Arguments: @peer *p@ = pointer to peer block
822 * @buf *b@ = buffer containing incoming packet
826 * Use: Handles a packet which needs to be sent to a peer.
829 extern void p_tun(peer */*p*/, buf */*b*/);
831 /* --- @p_interval@ --- *
837 * Use: Called periodically to do tidying.
840 extern void p_interval(void);
842 /* --- @p_stats@ --- *
844 * Arguments: @peer *p@ = pointer to a peer block
846 * Returns: A pointer to the peer's statistics.
849 extern stats *p_stats(peer */*p*/);
851 /* --- @p_ifname@ --- *
853 * Arguments: @peer *p@ = pointer to a peer block
855 * Returns: A pointer to the peer's interface name.
858 extern const char *p_ifname(peer */*p*/);
860 /* --- @p_addr@ --- *
862 * Arguments: @peer *p@ = pointer to a peer block
864 * Returns: A pointer to the peer's address.
867 extern const addr *p_addr(peer */*p*/);
869 /* --- @p_init@ --- *
871 * Arguments: @unsigned port@ = port number to listen to
875 * Use: Initializes the peer system; creates the socket.
878 extern void p_init(unsigned /*port*/);
880 /* --- @p_port@ --- *
884 * Returns: Port number used for socket.
887 unsigned p_port(void);
889 /* --- @p_create@ --- *
891 * Arguments: @const char *name@ = name for this peer
892 * @struct sockaddr *sa@ = socket address of peer
893 * @size_t sz@ = size of socket address
895 * Returns: Pointer to the peer block, or null if it failed.
897 * Use: Creates a new named peer block. No peer is actually attached
901 extern peer *p_create(const char */*name*/,
902 struct sockaddr */*sa*/, size_t /*sz*/);
904 /* --- @p_name@ --- *
906 * Arguments: @peer *p@ = pointer to a peer block
908 * Returns: A pointer to the peer's name.
911 extern const char *p_name(peer */*p*/);
913 /* --- @p_find@ --- *
915 * Arguments: @const char *name@ = name to look up
917 * Returns: Pointer to the peer block, or null if not found.
919 * Use: Finds a peer by name.
922 extern peer *p_find(const char */*name*/);
924 /* --- @p_destroy@ --- *
926 * Arguments: @peer *p@ = pointer to a peer
930 * Use: Destroys a peer.
933 extern void p_destroy(peer */*p*/);
935 /* --- @p_first@, @p_next@ --- *
937 * Arguments: @peer *p@ = a peer block
939 * Returns: @peer_first@ returns the first peer in some ordering;
940 * @peer_next@ returns the peer following a given one in the
941 * same ordering. Null is returned for the end of the list.
944 extern peer *p_first(void);
945 extern peer *p_next(peer */*p*/);
947 /*----- Tunnel interface --------------------------------------------------*/
949 /* --- @tun_init@ --- *
955 * Use: Initializes the tunneling system. Maybe this will require
956 * opening file descriptors or something.
959 extern void tun_init(void);
961 /* --- @tun_create@ --- *
963 * Arguments: @tunnel *t@ = pointer to tunnel block
964 * @peer *p@ = pointer to peer block
966 * Returns: Zero if it worked, nonzero on failure.
968 * Use: Initializes a new tunnel.
971 extern int tun_create(tunnel */*t*/, peer */*p*/);
973 /* --- @tun_ifname@ --- *
975 * Arguments: @tunnel *t@ = pointer to tunnel block
977 * Returns: A pointer to the tunnel's interface name.
980 extern const char *tun_ifname(tunnel */*t*/);
982 /* --- @tun_inject@ --- *
984 * Arguments: @tunnel *t@ = pointer to tunnel block
985 * @buf *b@ = buffer to send
989 * Use: Injects a packet into the local network stack.
992 extern void tun_inject(tunnel */*t*/, buf */*b*/);
994 /* --- @tun_destroy@ --- *
996 * Arguments: @tunnel *t@ = pointer to tunnel block
1000 * Use: Destroys a tunnel.
1003 extern void tun_destroy(tunnel */*t*/);
1005 /*----- Other handy utilities ---------------------------------------------*/
1007 /* --- @mpstr@ --- *
1009 * Arguments: @mp *m@ = a multiprecision integer
1011 * Returns: A pointer to the integer's textual representation.
1013 * Use: Converts a multiprecision integer to a string. Corrupts
1017 extern const char *mpstr(mp */*m*/);
1019 /* --- @timestr@ --- *
1021 * Arguments: @time_t t@ = a time to convert
1023 * Returns: A pointer to a textual representation of the time.
1025 * Use: Converts a time to a textual representation. Corrupts
1029 extern const char *timestr(time_t /*t*/);
1031 /*----- That's all, folks -------------------------------------------------*/