3 * $Id: tripe.h,v 1.9 2001/06/22 19:40:36 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 1.9 2001/06/22 19:40:36 mdw
33 * Support expiry of other peers' public keys.
35 * Revision 1.8 2001/06/19 22:10:57 mdw
36 * Some more constants for the algorithms. Document the packet format
37 * change for non-malleability. Moved @buf@ definitions to separate header
40 * Revision 1.7 2001/03/03 12:07:08 mdw
41 * Rename word get and put functions now that there's 16-bit support.
43 * Revision 1.6 2001/02/19 19:11:09 mdw
44 * Output buffering on admin connections.
46 * Revision 1.5 2001/02/16 21:41:43 mdw
47 * Major changes. See source files for details.
49 * Revision 1.4 2001/02/05 19:56:37 mdw
50 * Sequence number protection, and BSD tunnels.
52 * Revision 1.3 2001/02/04 01:17:55 mdw
53 * Create a configuration header file to tidy up command lines.
55 * Revision 1.2 2001/02/03 22:40:29 mdw
56 * Put timer information into the entropy pool when packets are received
57 * and on similar events. Reseed the generator on the interval timer.
59 * Revision 1.1 2001/02/03 20:26:37 mdw
71 /*----- Header files ------------------------------------------------------*/
86 #include <sys/types.h>
92 #include <sys/socket.h>
94 #include <netinet/in.h>
95 #include <arpa/inet.h>
101 #include <mLib/alloc.h>
102 #include <mLib/arena.h>
103 #include <mLib/bres.h>
104 #include <mLib/dstr.h>
105 #include <mLib/env.h>
106 #include <mLib/fdflags.h>
107 #include <mLib/fwatch.h>
108 #include <mLib/mdwopt.h>
109 #include <mLib/quis.h>
110 #include <mLib/report.h>
111 #include <mLib/sel.h>
112 #include <mLib/selbuf.h>
113 #include <mLib/sig.h>
114 #include <mLib/str.h>
115 #include <mLib/sub.h>
116 #include <mLib/trace.h>
118 #include <catacomb/gcipher.h>
119 #include <catacomb/gmac.h>
120 #include <catacomb/grand.h>
121 #include <catacomb/key.h>
122 #include <catacomb/paranoia.h>
124 #include <catacomb/noise.h>
125 #include <catacomb/rand.h>
127 #include <catacomb/mp.h>
128 #include <catacomb/mpmont.h>
129 #include <catacomb/mprand.h>
130 #include <catacomb/dh.h>
137 /*----- Magic numbers -----------------------------------------------------*/
139 /* --- Tunnel types --- */
145 /* --- Trace flags --- */
153 #define T_KEYEXCH 64u
154 #define T_KEYMGMT 128u
160 #define SEC(n) (n##u)
161 #define MIN(n) (n##u * 60u)
162 #define MEG(n) (n##ul * 1024ul * 1024ul)
164 /* --- Other things --- */
166 #define PKBUFSZ 65536
168 /*----- TrIPE protocol ----------------------------------------------------*/
170 /* --- TrIPE message format --- *
172 * A packet begins with a single-byte message type. The top four bits are a
173 * category code used to send the message to the right general place in the
174 * code; the bottom bits identify the actual message type.
177 #define MSG_CATMASK 0xf0
178 #define MSG_TYPEMASK 0x0f
180 /* --- Encrypted message packets --- *
182 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
183 * message content is a symmetric-encrypted block (see below). Reception of
184 * a packet encrypted under a new key implicitly permits that key to be used
185 * to send further packets.
187 * The only packet type accepted is zero.
189 * Packets may be encrypted under any live keyset, but should use the most
193 #define MSG_PACKET 0x00
195 /* --- Key exchange packets --- */
197 #define MSG_KEYEXCH 0x10
199 #define KX_PRECHAL 0u
204 #define KX_SWITCHOK 5u
207 /* --- Symmetric encryption and keysets --- *
209 * Packets consist of an 80-bit MAC, a 32-bit sequence number, and the
212 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
213 * stealing (as described in [Schneier]. The initialization vector is
214 * selected randomly, and prepended to the actual ciphertext.
216 * The MAC is computed using the HMAC construction with RIPEMD160 over the
217 * sequence number and the ciphertext (with iV); the first 80 bits of the
218 * output are used. (This is the minimum allowed by the draft FIPS for HMAC,
219 * and the recommended truncation.)
221 * A keyset consists of
223 * * an integrity (MAC) key;
224 * * a confidentiality (encryption) key; and
225 * * a sequence numbering space
227 * in each direction. The packets sent by a host encrypted under a
228 * particular keyset are assigned consecutive sequence numbers starting from
229 * zero. The receiving host must ensure that it only accepts each packet at
230 * most once. It should maintain a window of sequence numbers: packets with
231 * numbers beyond the end of the window are accepted and cause the window to
232 * be advanced; packets with numbers before the start of the window are
233 * rejected; packets with numbers which appear within the window are accepted
234 * only if the number has not been seen before.
236 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
237 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
238 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
239 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
243 /*----- Cipher selections -------------------------------------------------*/
245 #include <catacomb/blowfish.h>
246 #include <catacomb/blowfish-cbc.h>
247 #include <catacomb/rmd160.h>
248 #include <catacomb/rmd160-hmac.h>
250 #define CIPHER (&blowfish_cbc)
251 #define MAC (&rmd160_hmac)
253 #define HASH_CTX rmd160_ctx
254 #define HASH_INIT rmd160_init
255 #define HASH rmd160_hash
256 #define HASH_STRING(c, s) HASH((c), s, sizeof(s))
257 #define HASH_DONE rmd160_done
258 #define HASHSZ RMD160_HASHSZ
261 #define IVSZ BLOWFISH_BLKSZ
264 /*----- Data structures ---------------------------------------------------*/
266 /* --- Socket addresses --- *
268 * A magic union of supported socket addresses.
273 struct sockaddr_in sin;
276 /* --- A symmetric keyset --- *
278 * A keyset contains a set of symmetric keys for encrypting and decrypting
279 * packets. Keysets are stored in a list, sorted in reverse order of
280 * creation, so that the most recent keyset (the one most likely to be used)
283 * Each keyset has a time limit and a data limit. The keyset is destroyed
284 * when either it has existed for too long, or it has been used to encrypt
285 * too much data. New key exchanges are triggered when keys are close to
289 typedef struct keyset {
290 struct keyset *next; /* Next active keyset in the list */
291 unsigned ref; /* Reference count for keyset */
292 time_t t_exp; /* Expiry time for this keyset */
293 unsigned long sz_exp; /* Data limit for the keyset */
294 T( unsigned seq; ) /* Sequence number for tracing */
295 unsigned f; /* Various useful flags */
296 gcipher *cin, *cout; /* Keyset ciphers for encryption */
297 gmac *min, *mout; /* Keyset MACs for integrity */
298 uint32 oseq; /* Outbound sequence number */
299 uint32 iseq, iwin; /* Inbound sequence number */
302 #define KS_SEQWINSZ 32 /* Bits in sequence number window */
304 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
305 #define KSF_LINK 2u /* Key is in a linked list */
307 /* --- Key exchange --- *
309 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
310 * Protocol has a number of desirable features (e.g., perfect forward
311 * secrecy, and zero-knowledge authentication) which make it attractive for
312 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
319 typedef struct kxchal {
320 struct keyexch *kx; /* Pointer back to key exchange */
321 mp *c; /* Responder's challenge */
322 mp *r; /* My reply to the challenge */
323 keyset *ks; /* Pointer to temporary keyset */
324 unsigned f; /* Various useful flags */
325 sel_timer t; /* Response timer for challenge */
326 octet hc[HASHSZ]; /* Hash of his challenge */
327 octet hrx[HASHSZ]; /* My expected reply hash */
328 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
329 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
330 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
331 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
334 typedef struct keyexch {
335 struct peer *p; /* Pointer back to the peer */
336 keyset **ks; /* Peer's list of keysets */
337 unsigned f; /* Various useful flags */
338 unsigned s; /* Current state in exchange */
339 sel_timer t; /* Timer for next exchange */
340 dh_pub kpub; /* Peer's public key */
341 time_t texp_kpub; /* Expiry time for public key */
342 mp *alpha; /* My temporary secret */
343 mp *c; /* My challenge */
344 mp *rx; /* The expected response */
345 unsigned nr; /* Number of extant responses */
346 time_t t_valid; /* When this exchange goes bad */
347 octet hc[HASHSZ]; /* Hash of my challenge */
348 kxchal *r[KX_NCHAL]; /* Array of challenges */
351 #define KXF_TIMER 1u /* Waiting for a timer to go off */
352 #define KXF_DEAD 2u /* The key-exchanger isn't up */
353 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
356 KXS_DEAD, /* Uninitialized state (magical) */
357 KXS_CHAL, /* Main answer-challenges state */
358 KXS_COMMIT, /* Committed: send switch request */
359 KXS_SWITCH /* Switched: send confirmation */
362 /* --- Tunnel structure --- *
364 * Used to maintain system-specific information about the tunnel interface.
367 typedef struct tunnel {
368 #if TUN_TYPE == TUN_UNET
369 sel_file f; /* Selector for Usernet device */
370 struct peer *p; /* Pointer to my peer */
371 #elif TUN_TYPE == TUN_BSD
372 sel_file f; /* Selector for tunnel device */
373 struct peer *p; /* Pointer to my peer */
374 unsigned n; /* Number of my tunnel device */
376 # error "No support for this tunnel type"
380 /* --- Peer statistics --- *
382 * Contains various interesting and not-so-interesting statistics about a
383 * peer. This is updated by various parts of the code. The format of the
384 * structure isn't considered private, and @p_stats@ returns a pointer to the
385 * statistics block for a given peer.
388 typedef struct stats {
389 unsigned long sz_in, sz_out; /* Size of all data in and out */
390 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
391 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
392 time_t t_start, t_last; /* Time peer created, last recv */
393 unsigned long n_reject; /* Number of rejected packets */
394 unsigned long n_in, n_out; /* Number of packets in and out */
395 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
396 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
399 /* --- Peer structure --- *
401 * The main structure which glues everything else together.
404 typedef struct peer {
405 struct peer *next, *prev; /* Links to next and previous */
406 char *name; /* Name of this peer */
407 tunnel t; /* Tunnel for local packets */
408 keyset *ks; /* List head for keysets */
409 buf b; /* Buffer for sending packets */
410 addr peer; /* Peer socket address */
411 size_t sasz; /* Socket address size */
412 stats st; /* Statistics */
413 keyexch kx; /* Key exchange protocol block */
416 /* --- Admin structure --- */
418 #define OBUFSZ 16384u
420 typedef struct obuf {
421 struct obuf *next; /* Next buffer in list */
422 char *p_in, *p_out; /* Pointers into the buffer */
423 char buf[OBUFSZ]; /* The actual buffer */
426 typedef struct admin {
427 struct admin *next, *prev; /* Links to next and previous */
428 unsigned f; /* Various useful flags */
430 unsigned seq; /* Sequence number for tracing */
432 char *pname; /* Peer name to create */
433 char *paddr; /* Address string to resolve */
434 obuf *o_head, *o_tail; /* Output buffer list */
435 selbuf b; /* Line buffer for commands */
436 sel_file w; /* Selector for write buffering */
437 bres_client r; /* Background resolver task */
438 sel_timer t; /* Timer for resolver */
439 addr peer; /* Address to set */
440 size_t sasz; /* Size of the address */
443 #define AF_DEAD 1u /* Destroy this admin block */
444 #define AF_LOCK 2u /* Don't destroy it yet */
446 /*----- Global variables --------------------------------------------------*/
448 extern sel_state sel; /* Global I/O event state */
449 extern dh_priv kpriv; /* Our private key */
450 extern mpmont mg; /* Montgomery context for DH group */
451 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
454 extern const trace_opt tr_opts[]; /* Trace options array */
455 extern unsigned tr_flags; /* Trace options flags */
458 /*----- Other macros ------------------------------------------------------*/
460 #define TIMER noise_timer(RAND_GLOBAL)
462 /*----- Key management ----------------------------------------------------*/
464 /* --- @km_interval@ --- *
468 * Returns: Zero if OK, nonzero to force reloading of keys.
470 * Use: Called on the interval timer to perform various useful jobs.
473 extern int km_interval(void);
475 /* --- @km_init@ --- *
477 * Arguments: @const char *kr_priv@ = private keyring file
478 * @const char *kr_pub@ = public keyring file
479 * @const char *tag@ = tag to load
483 * Use: Initializes, and loads the private key.
486 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
487 const char */*tag*/);
489 /* --- @km_getpubkey@ --- *
491 * Arguments: @const char *tag@ = public key tag to load
492 * @dh_pub *kpub@ = where to put the public key
493 * @time_t *t_exp@ = where to put the expiry time
495 * Returns: Zero if OK, nonzero if it failed.
497 * Use: Fetches a public key from the keyring.
500 extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/,
503 /*----- Key exchange ------------------------------------------------------*/
505 /* --- @kx_start@ --- *
507 * Arguments: @keyexch *kx@ = pointer to key exchange context
511 * Use: Stimulates a key exchange. If a key exchage is in progress,
512 * a new challenge is sent (unless the quiet timer forbids
513 * this); if no exchange is in progress, one is commenced.
516 extern void kx_start(keyexch */*kx*/);
518 /* --- @kx_message@ --- *
520 * Arguments: @keyexch *kx@ = pointer to key exchange context
521 * @unsigned msg@ = the message code
522 * @buf *b@ = pointer to buffer containing the packet
526 * Use: Reads a packet containing key exchange messages and handles
530 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
532 /* --- @kx_free@ --- *
534 * Arguments: @keyexch *kx@ = pointer to key exchange context
538 * Use: Frees everything in a key exchange context.
541 extern void kx_free(keyexch */*kx*/);
543 /* --- @kx_newkeys@ --- *
545 * Arguments: @keyexch *kx@ = pointer to key exchange context
549 * Use: Informs the key exchange module that its keys may have
550 * changed. If fetching the new keys fails, the peer will be
551 * destroyed, we log messages and struggle along with the old
555 extern void kx_newkeys(keyexch */*kx*/);
557 /* --- @kx_init@ --- *
559 * Arguments: @keyexch *kx@ = pointer to key exchange context
560 * @peer *p@ = pointer to peer context
561 * @keyset **ks@ = pointer to keyset list
563 * Returns: Zero if OK, nonzero if it failed.
565 * Use: Initializes a key exchange module. The module currently
566 * contains no keys, and will attempt to initiate a key
570 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
572 /*----- Keysets and symmetric cryptography --------------------------------*/
574 /* --- @ks_drop@ --- *
576 * Arguments: @keyset *ks@ = pointer to a keyset
580 * Use: Decrements a keyset's reference counter. If the counter hits
581 * zero, the keyset is freed.
584 extern void ks_drop(keyset */*ks*/);
586 /* --- @ks_gen@ --- *
588 * Arguments: @const void *k@ = pointer to key material
589 * @size_t x, y, z@ = offsets into key material (see below)
591 * Returns: A pointer to the new keyset.
593 * Use: Derives a new keyset from the given key material. The
594 * offsets @x@, @y@ and @z@ separate the key material into three
595 * parts. Between the @k@ and @k + x@ is `my' contribution to
596 * the key material; between @k + x@ and @k + y@ is `your'
597 * contribution; and between @k + y@ and @k + z@ is a shared
598 * value we made together. These are used to construct two
599 * pairs of symmetric keys. Each pair consists of an encryption
600 * key and a message authentication key. One pair is used for
601 * outgoing messages, the other for incoming messages.
603 * The new key is marked so that it won't be selected for output
604 * by @ksl_encrypt@. You can still encrypt data with it by
605 * calling @ks_encrypt@ directly.
608 extern keyset *ks_gen(const void */*k*/,
609 size_t /*x*/, size_t /*y*/, size_t /*z*/);
611 /* --- @ks_tregen@ --- *
613 * Arguments: @keyset *ks@ = pointer to a keyset
615 * Returns: The time at which moves ought to be made to replace this key.
618 extern time_t ks_tregen(keyset */*ks*/);
620 /* --- @ks_activate@ --- *
622 * Arguments: @keyset *ks@ = pointer to a keyset
626 * Use: Activates a keyset, so that it can be used for encrypting
630 extern void ks_activate(keyset */*ks*/);
632 /* --- @ks_encrypt@ --- *
634 * Arguments: @keyset *ks@ = pointer to a keyset
635 * @buf *b@ = pointer to input buffer
636 * @buf *bb@ = pointer to output buffer
638 * Returns: Zero if OK, nonzero if the key needs replacing. If the
639 * encryption failed, the output buffer is broken and zero is
642 * Use: Encrypts a block of data using the key. Note that the `key
643 * ought to be replaced' notification is only ever given once
644 * for each key. Also note that this call forces a keyset to be
645 * used even if it's marked as not for data output.
648 extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
650 /* --- @ks_decrypt@ --- *
652 * Arguments: @keyset *ks@ = pointer to a keyset
653 * @buf *b@ = pointer to an input buffer
654 * @buf *bb@ = pointer to an output buffer
656 * Returns: Zero on success, or nonzero if there was some problem.
658 * Use: Attempts to decrypt a message using a given key. Note that
659 * requesting decryption with a key directly won't clear a
660 * marking that it's not for encryption.
663 extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
665 /* --- @ksl_free@ --- *
667 * Arguments: @keyset **ksroot@ = pointer to keyset list head
671 * Use: Frees (releases references to) all of the keys in a keyset.
674 extern void ksl_free(keyset **/*ksroot*/);
676 /* --- @ksl_link@ --- *
678 * Arguments: @keyset **ksroot@ = pointer to keyset list head
679 * @keyset *ks@ = pointer to a keyset
683 * Use: Links a keyset into a list. A keyset can only be on one list
684 * at a time. Bad things happen otherwise.
687 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
689 /* --- @ksl_prune@ --- *
691 * Arguments: @keyset **ksroot@ = pointer to keyset list head
695 * Use: Prunes the keyset list by removing keys which mustn't be used
699 extern void ksl_prune(keyset **/*ksroot*/);
701 /* --- @ksl_encrypt@ --- *
703 * Arguments: @keyset **ksroot@ = pointer to keyset list head
704 * @buf *b@ = pointer to input buffer
705 * @buf *bb@ = pointer to output buffer
707 * Returns: Nonzero if a new key is needed.
709 * Use: Encrypts a packet.
712 extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
714 /* --- @ksl_decrypt@ --- *
716 * Arguments: @keyset **ksroot@ = pointer to keyset list head
717 * @buf *b@ = pointer to input buffer
718 * @buf *bb@ = pointer to output buffer
720 * Returns: Nonzero if the packet couldn't be decrypted.
722 * Use: Decrypts a packet.
725 extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
727 /*----- Administration interface ------------------------------------------*/
729 /* --- @a_warn@ --- *
731 * Arguments: @const char *fmt@ = pointer to format string
732 * @...@ = other arguments
736 * Use: Informs all admin connections of a warning.
739 extern void a_warn(const char */*fmt*/, ...);
741 /* --- @a_create@ --- *
743 * Arguments: @int fd_in, fd_out@ = file descriptors to use
747 * Use: Creates a new admin connection.
750 extern void a_create(int /*fd_in*/, int /*fd_out*/);
752 /* --- @a_quit@ --- *
758 * Use: Shuts things down nicely.
761 extern void a_quit(void);
763 /* --- @a_daemon@ --- *
769 * Use: Informs the admin module that it's a daemon.
772 extern void a_daemon(void);
774 /* --- @a_init@ --- *
776 * Arguments: @const char *sock@ = socket name to create
780 * Use: Creates the admin listening socket.
783 extern void a_init(const char */*sock*/);
785 /*----- Peer management ---------------------------------------------------*/
787 /* --- @p_txstart@ --- *
789 * Arguments: @peer *p@ = pointer to peer block
790 * @unsigned msg@ = message type code
792 * Returns: A pointer to a buffer to write to.
794 * Use: Starts sending to a peer. Only one send can happen at a
798 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
800 /* --- @p_txend@ --- *
802 * Arguments: @peer *p@ = pointer to peer block
806 * Use: Sends a packet to the peer.
809 extern void p_txend(peer */*p*/);
813 * Arguments: @peer *p@ = pointer to peer block
814 * @buf *b@ = buffer containing incoming packet
818 * Use: Handles a packet which needs to be sent to a peer.
821 extern void p_tun(peer */*p*/, buf */*b*/);
823 /* --- @p_interval@ --- *
829 * Use: Called periodically to do tidying.
832 extern void p_interval(void);
834 /* --- @p_stats@ --- *
836 * Arguments: @peer *p@ = pointer to a peer block
838 * Returns: A pointer to the peer's statistics.
841 extern stats *p_stats(peer */*p*/);
843 /* --- @p_ifname@ --- *
845 * Arguments: @peer *p@ = pointer to a peer block
847 * Returns: A pointer to the peer's interface name.
850 extern const char *p_ifname(peer */*p*/);
852 /* --- @p_addr@ --- *
854 * Arguments: @peer *p@ = pointer to a peer block
856 * Returns: A pointer to the peer's address.
859 extern const addr *p_addr(peer */*p*/);
861 /* --- @p_init@ --- *
863 * Arguments: @unsigned port@ = port number to listen to
867 * Use: Initializes the peer system; creates the socket.
870 extern void p_init(unsigned /*port*/);
872 /* --- @p_port@ --- *
876 * Returns: Port number used for socket.
879 unsigned p_port(void);
881 /* --- @p_create@ --- *
883 * Arguments: @const char *name@ = name for this peer
884 * @struct sockaddr *sa@ = socket address of peer
885 * @size_t sz@ = size of socket address
887 * Returns: Pointer to the peer block, or null if it failed.
889 * Use: Creates a new named peer block. No peer is actually attached
893 extern peer *p_create(const char */*name*/,
894 struct sockaddr */*sa*/, size_t /*sz*/);
896 /* --- @p_name@ --- *
898 * Arguments: @peer *p@ = pointer to a peer block
900 * Returns: A pointer to the peer's name.
903 extern const char *p_name(peer */*p*/);
905 /* --- @p_find@ --- *
907 * Arguments: @const char *name@ = name to look up
909 * Returns: Pointer to the peer block, or null if not found.
911 * Use: Finds a peer by name.
914 extern peer *p_find(const char */*name*/);
916 /* --- @p_destroy@ --- *
918 * Arguments: @peer *p@ = pointer to a peer
922 * Use: Destroys a peer.
925 extern void p_destroy(peer */*p*/);
927 /* --- @p_first@, @p_next@ --- *
929 * Arguments: @peer *p@ = a peer block
931 * Returns: @peer_first@ returns the first peer in some ordering;
932 * @peer_next@ returns the peer following a given one in the
933 * same ordering. Null is returned for the end of the list.
936 extern peer *p_first(void);
937 extern peer *p_next(peer */*p*/);
939 /*----- Tunnel interface --------------------------------------------------*/
941 /* --- @tun_init@ --- *
947 * Use: Initializes the tunneling system. Maybe this will require
948 * opening file descriptors or something.
951 extern void tun_init(void);
953 /* --- @tun_create@ --- *
955 * Arguments: @tunnel *t@ = pointer to tunnel block
956 * @peer *p@ = pointer to peer block
958 * Returns: Zero if it worked, nonzero on failure.
960 * Use: Initializes a new tunnel.
963 extern int tun_create(tunnel */*t*/, peer */*p*/);
965 /* --- @tun_ifname@ --- *
967 * Arguments: @tunnel *t@ = pointer to tunnel block
969 * Returns: A pointer to the tunnel's interface name.
972 extern const char *tun_ifname(tunnel */*t*/);
974 /* --- @tun_inject@ --- *
976 * Arguments: @tunnel *t@ = pointer to tunnel block
977 * @buf *b@ = buffer to send
981 * Use: Injects a packet into the local network stack.
984 extern void tun_inject(tunnel */*t*/, buf */*b*/);
986 /* --- @tun_destroy@ --- *
988 * Arguments: @tunnel *t@ = pointer to tunnel block
992 * Use: Destroys a tunnel.
995 extern void tun_destroy(tunnel */*t*/);
997 /*----- Other handy utilities ---------------------------------------------*/
1001 * Arguments: @mp *m@ = a multiprecision integer
1003 * Returns: A pointer to the integer's textual representation.
1005 * Use: Converts a multiprecision integer to a string. Corrupts
1009 extern const char *mpstr(mp */*m*/);
1011 /* --- @timestr@ --- *
1013 * Arguments: @time_t t@ = a time to convert
1015 * Returns: A pointer to a textual representation of the time.
1017 * Use: Converts a time to a textual representation. Corrupts
1021 extern const char *timestr(time_t /*t*/);
1023 /*----- That's all, folks -------------------------------------------------*/