3 * $Id: tripe.h,v 1.7 2001/03/03 12:07:08 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 1.7 2001/03/03 12:07:08 mdw
33 * Rename word get and put functions now that there's 16-bit support.
35 * Revision 1.6 2001/02/19 19:11:09 mdw
36 * Output buffering on admin connections.
38 * Revision 1.5 2001/02/16 21:41:43 mdw
39 * Major changes. See source files for details.
41 * Revision 1.4 2001/02/05 19:56:37 mdw
42 * Sequence number protection, and BSD tunnels.
44 * Revision 1.3 2001/02/04 01:17:55 mdw
45 * Create a configuration header file to tidy up command lines.
47 * Revision 1.2 2001/02/03 22:40:29 mdw
48 * Put timer information into the entropy pool when packets are received
49 * and on similar events. Reseed the generator on the interval timer.
51 * Revision 1.1 2001/02/03 20:26:37 mdw
63 /*----- Header files ------------------------------------------------------*/
78 #include <sys/types.h>
84 #include <sys/socket.h>
86 #include <netinet/in.h>
87 #include <arpa/inet.h>
93 #include <mLib/alloc.h>
94 #include <mLib/arena.h>
95 #include <mLib/bres.h>
96 #include <mLib/dstr.h>
98 #include <mLib/fdflags.h>
99 #include <mLib/fwatch.h>
100 #include <mLib/mdwopt.h>
101 #include <mLib/quis.h>
102 #include <mLib/report.h>
103 #include <mLib/sel.h>
104 #include <mLib/selbuf.h>
105 #include <mLib/sig.h>
106 #include <mLib/str.h>
107 #include <mLib/sub.h>
108 #include <mLib/trace.h>
110 #include <catacomb/gcipher.h>
111 #include <catacomb/gmac.h>
112 #include <catacomb/grand.h>
113 #include <catacomb/key.h>
114 #include <catacomb/paranoia.h>
116 #include <catacomb/noise.h>
117 #include <catacomb/rand.h>
119 #include <catacomb/mp.h>
120 #include <catacomb/mpmont.h>
121 #include <catacomb/mprand.h>
122 #include <catacomb/dh.h>
128 /*----- Magic numbers -----------------------------------------------------*/
130 /* --- Tunnel types --- */
136 /* --- Trace flags --- */
144 #define T_KEYEXCH 64u
145 #define T_KEYMGMT 128u
151 #define SEC(n) (n##u)
152 #define MIN(n) (n##u * 60u)
153 #define MEG(n) (n##ul * 1024ul * 1024ul)
155 /* --- Other things --- */
157 #define PKBUFSZ 65536
159 /*----- TrIPE protocol ----------------------------------------------------*/
161 /* --- TrIPE message format --- *
163 * A packet begins with a single-byte message type. The top four bits are a
164 * category code used to send the message to the right general place in the
165 * code; the bottom bits identify the actual message type.
168 #define MSG_CATMASK 0xf0
169 #define MSG_TYPEMASK 0x0f
171 /* --- Encrypted message packets --- *
173 * Messages of category @MSG_PACKET@ contain encrypted network packets. The
174 * message content is a symmetric-encrypted block (see below). Reception of
175 * a packet encrypted under a new key implicitly permits that key to be used
176 * to send further packets.
178 * The only packet type accepted is zero.
180 * Packets may be encrypted under any live keyset, but should use the most
184 #define MSG_PACKET 0x00
186 /* --- Key exchange packets --- */
188 #define MSG_KEYEXCH 0x10
190 #define KX_PRECHAL 0u
195 #define KX_SWITCHOK 5u
198 /* --- Symmetric encryption and keysets --- *
200 * Packets consist of a 64-bit MAC, a 32-bit sequence number, and the
203 * The MAC is computed using the HMAC construction with RIPEMD160 over the
204 * sequence number and the original packet plaintext; the first 64 bits of
205 * the output are used.
207 * The plaintext is encrypted using Blowfish in CBC mode with ciphertext
208 * stealing (as described in [Schneier]. The initialization vector is
209 * precisely the 64-bit MAC computed previously.
211 * A keyset consists of
213 * * an integrity (MAC) key;
214 * * a confidentiality (encryption) key; and
215 * * a sequence numbering space
217 * in each direction. The packets sent by a host encrypted under a
218 * particular keyset are assigned consecutive sequence numbers starting from
219 * zero. The receiving host must ensure that it only accepts each packet at
220 * most once. It should maintain a window of sequence numbers: packets with
221 * numbers beyond the end of the window are accepted and cause the window to
222 * be advanced; packets with numbers before the start of the window are
223 * rejected; packets with numbers which appear within the window are accepted
224 * only if the number has not been seen before.
226 * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the
227 * newly-negotiated keyset in a `listen-only' state: it may not send a packet
228 * encrypted under the keyset until either it has received a @KX_SWITCH@ or
229 * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from
233 /*----- Cipher selections -------------------------------------------------*/
235 #include <catacomb/blowfish.h>
236 #include <catacomb/blowfish-cbc.h>
237 #include <catacomb/rmd160.h>
238 #include <catacomb/rmd160-hmac.h>
240 #define CIPHER (&blowfish_cbc)
241 #define MAC (&rmd160_hmac)
243 #define HASH_CTX rmd160_ctx
244 #define HASH_INIT rmd160_init
245 #define HASH rmd160_hash
246 #define HASH_STRING(c, s) HASH((c), s, sizeof(s))
247 #define HASH_DONE rmd160_done
248 #define HASHSZ RMD160_HASHSZ
250 /*----- Data structures ---------------------------------------------------*/
254 * Buffers provide a simple stream-like interface for building and parsing
259 octet *base, *p, *limit; /* Pointers to the buffer */
260 unsigned f; /* Various flags */
263 #define BF_BROKEN 1u /* Buffer is broken */
265 /* --- Socket addresses --- *
267 * A magic union of supported socket addresses.
272 struct sockaddr_in sin;
275 /* --- A symmetric keyset --- *
277 * A keyset contains a set of symmetric keys for encrypting and decrypting
278 * packets. Keysets are stored in a list, sorted in reverse order of
279 * creation, so that the most recent keyset (the one most likely to be used)
282 * Each keyset has a time limit and a data limit. The keyset is destroyed
283 * when either it has existed for too long, or it has been used to encrypt
284 * too much data. New key exchanges are triggered when keys are close to
288 typedef struct keyset {
289 struct keyset *next; /* Next active keyset in the list */
290 unsigned ref; /* Reference count for keyset */
291 time_t t_exp; /* Expiry time for this keyset */
292 unsigned long sz_exp; /* Data limit for the keyset */
293 T( unsigned seq; ) /* Sequence number for tracing */
294 unsigned f; /* Various useful flags */
295 gcipher *cin, *cout; /* Keyset ciphers for encryption */
296 gmac *min, *mout; /* Keyset MACs for integrity */
297 uint32 oseq; /* Outbound sequence number */
298 uint32 iseq, iwin; /* Inbound sequence number */
301 #define KS_SEQWINSZ 32 /* Bits in sequence number window */
303 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
304 #define KSF_LINK 2u /* Key is in a linked list */
306 /* --- Key exchange --- *
308 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
309 * Protocol has a number of desirable features (e.g., perfect forward
310 * secrecy, and zero-knowledge authentication) which make it attractive for
311 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
318 typedef struct kxchal {
319 struct keyexch *kx; /* Pointer back to key exchange */
320 mp *c; /* Responder's challenge */
321 mp *r; /* My reply to the challenge */
322 keyset *ks; /* Pointer to temporary keyset */
323 unsigned f; /* Various useful flags */
324 sel_timer t; /* Response timer for challenge */
325 octet hc[HASHSZ]; /* Hash of his challenge */
326 octet hrx[HASHSZ]; /* My expected reply hash */
327 octet hswrq_in[HASHSZ]; /* Inbound switch request message */
328 octet hswok_in[HASHSZ]; /* Inbound switch confirmation */
329 octet hswrq_out[HASHSZ]; /* Outbound switch request message */
330 octet hswok_out[HASHSZ]; /* Outbound switch confirmation */
333 typedef struct keyexch {
334 struct peer *p; /* Pointer back to the peer */
335 keyset **ks; /* Peer's list of keysets */
336 unsigned f; /* Various useful flags */
337 unsigned s; /* Current state in exchange */
338 sel_timer t; /* Timer for next exchange */
339 dh_pub kpub; /* Peer's public key */
340 mp *alpha; /* My temporary secret */
341 mp *c; /* My challenge */
342 mp *rx; /* The expected response */
343 unsigned nr; /* Number of extant responses */
344 time_t t_valid; /* When this exchange goes bad */
345 octet hc[HASHSZ]; /* Hash of my challenge */
346 kxchal *r[KX_NCHAL]; /* Array of challenges */
349 #define KXF_TIMER 1u /* Waiting for a timer to go off */
352 KXS_DEAD, /* Uninitialized state (magical) */
353 KXS_CHAL, /* Main answer-challenges state */
354 KXS_COMMIT, /* Committed: send switch request */
355 KXS_SWITCH /* Switched: send confirmation */
358 /* --- Tunnel structure --- *
360 * Used to maintain system-specific information about the tunnel interface.
363 typedef struct tunnel {
364 #if TUN_TYPE == TUN_UNET
365 sel_file f; /* Selector for Usernet device */
366 struct peer *p; /* Pointer to my peer */
367 #elif TUN_TYPE == TUN_BSD
368 sel_file f; /* Selector for tunnel device */
369 struct peer *p; /* Pointer to my peer */
370 unsigned n; /* Number of my tunnel device */
372 # error "No support for this tunnel type"
376 /* --- Peer statistics --- *
378 * Contains various interesting and not-so-interesting statistics about a
379 * peer. This is updated by various parts of the code. The format of the
380 * structure isn't considered private, and @p_stats@ returns a pointer to the
381 * statistics block for a given peer.
384 typedef struct stats {
385 unsigned long sz_in, sz_out; /* Size of all data in and out */
386 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
387 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
388 time_t t_start, t_last; /* Time peer created, last recv */
389 unsigned long n_reject; /* Number of rejected packets */
390 unsigned long n_in, n_out; /* Number of packets in and out */
391 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
392 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
395 /* --- Peer structure --- *
397 * The main structure which glues everything else together.
400 typedef struct peer {
401 struct peer *next, *prev; /* Links to next and previous */
402 char *name; /* Name of this peer */
403 tunnel t; /* Tunnel for local packets */
404 keyset *ks; /* List head for keysets */
405 buf b; /* Buffer for sending packets */
406 addr peer; /* Peer socket address */
407 size_t sasz; /* Socket address size */
408 stats st; /* Statistics */
409 keyexch kx; /* Key exchange protocol block */
412 /* --- Admin structure --- */
414 #define OBUFSZ 16384u
416 typedef struct obuf {
417 struct obuf *next; /* Next buffer in list */
418 char *p_in, *p_out; /* Pointers into the buffer */
419 char buf[OBUFSZ]; /* The actual buffer */
422 typedef struct admin {
423 struct admin *next, *prev; /* Links to next and previous */
424 unsigned f; /* Various useful flags */
426 unsigned seq; /* Sequence number for tracing */
428 char *pname; /* Peer name to create */
429 char *paddr; /* Address string to resolve */
430 obuf *o_head, *o_tail; /* Output buffer list */
431 selbuf b; /* Line buffer for commands */
432 sel_file w; /* Selector for write buffering */
433 bres_client r; /* Background resolver task */
434 sel_timer t; /* Timer for resolver */
435 addr peer; /* Address to set */
436 size_t sasz; /* Size of the address */
439 #define AF_DEAD 1u /* Destroy this admin block */
440 #define AF_LOCK 2u /* Don't destroy it yet */
442 /*----- Global variables --------------------------------------------------*/
444 extern sel_state sel; /* Global I/O event state */
445 extern dh_priv kpriv; /* Our private key */
446 extern mpmont mg; /* Montgomery context for DH group */
447 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
450 extern const trace_opt tr_opts[]; /* Trace options array */
451 extern unsigned tr_flags; /* Trace options flags */
454 /*----- Other macros ------------------------------------------------------*/
456 #define TIMER noise_timer(RAND_GLOBAL)
458 /*----- Key management ----------------------------------------------------*/
460 /* --- @km_interval@ --- *
464 * Returns: Zero if OK, nonzero to force reloading of keys.
466 * Use: Called on the interval timer to perform various useful jobs.
469 extern int km_interval(void);
471 /* --- @km_init@ --- *
473 * Arguments: @const char *kr_priv@ = private keyring file
474 * @const char *kr_pub@ = public keyring file
475 * @const char *tag@ = tag to load
479 * Use: Initializes, and loads the private key.
482 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
483 const char */*tag*/);
485 /* --- @km_getpubkey@ --- *
487 * Arguments: @const char *tag@ = public key tag to load
488 * @dh_pub *kpub@ = where to put the public key
490 * Returns: Zero if OK, nonzero if it failed.
492 * Use: Fetches a public key from the keyring.
495 extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/);
497 /*----- Key exchange ------------------------------------------------------*/
499 /* --- @kx_start@ --- *
501 * Arguments: @keyexch *kx@ = pointer to key exchange context
505 * Use: Stimulates a key exchange. If a key exchage is in progress,
506 * a new challenge is sent (unless the quiet timer forbids
507 * this); if no exchange is in progress, one is commenced.
510 extern void kx_start(keyexch */*kx*/);
512 /* --- @kx_message@ --- *
514 * Arguments: @keyexch *kx@ = pointer to key exchange context
515 * @unsigned msg@ = the message code
516 * @buf *b@ = pointer to buffer containing the packet
520 * Use: Reads a packet containing key exchange messages and handles
524 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
526 /* --- @kx_free@ --- *
528 * Arguments: @keyexch *kx@ = pointer to key exchange context
532 * Use: Frees everything in a key exchange context.
535 extern void kx_free(keyexch */*kx*/);
537 /* --- @kx_newkeys@ --- *
539 * Arguments: @keyexch *kx@ = pointer to key exchange context
543 * Use: Informs the key exchange module that its keys may have
544 * changed. If fetching the new keys fails, the peer will be
545 * destroyed, we log messages and struggle along with the old
549 extern void kx_newkeys(keyexch */*kx*/);
551 /* --- @kx_init@ --- *
553 * Arguments: @keyexch *kx@ = pointer to key exchange context
554 * @peer *p@ = pointer to peer context
555 * @keyset **ks@ = pointer to keyset list
557 * Returns: Zero if OK, nonzero if it failed.
559 * Use: Initializes a key exchange module. The module currently
560 * contains no keys, and will attempt to initiate a key
564 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
566 /*----- Keysets and symmetric cryptography --------------------------------*/
568 /* --- @ks_drop@ --- *
570 * Arguments: @keyset *ks@ = pointer to a keyset
574 * Use: Decrements a keyset's reference counter. If the counter hits
575 * zero, the keyset is freed.
578 extern void ks_drop(keyset */*ks*/);
580 /* --- @ks_gen@ --- *
582 * Arguments: @const void *k@ = pointer to key material
583 * @size_t x, y, z@ = offsets into key material (see below)
585 * Returns: A pointer to the new keyset.
587 * Use: Derives a new keyset from the given key material. The
588 * offsets @x@, @y@ and @z@ separate the key material into three
589 * parts. Between the @k@ and @k + x@ is `my' contribution to
590 * the key material; between @k + x@ and @k + y@ is `your'
591 * contribution; and between @k + y@ and @k + z@ is a shared
592 * value we made together. These are used to construct two
593 * pairs of symmetric keys. Each pair consists of an encryption
594 * key and a message authentication key. One pair is used for
595 * outgoing messages, the other for incoming messages.
597 * The new key is marked so that it won't be selected for output
598 * by @ksl_encrypt@. You can still encrypt data with it by
599 * calling @ks_encrypt@ directly.
602 extern keyset *ks_gen(const void */*k*/,
603 size_t /*x*/, size_t /*y*/, size_t /*z*/);
605 /* --- @ks_tregen@ --- *
607 * Arguments: @keyset *ks@ = pointer to a keyset
609 * Returns: The time at which moves ought to be made to replace this key.
612 extern time_t ks_tregen(keyset */*ks*/);
614 /* --- @ks_activate@ --- *
616 * Arguments: @keyset *ks@ = pointer to a keyset
620 * Use: Activates a keyset, so that it can be used for encrypting
624 extern void ks_activate(keyset */*ks*/);
626 /* --- @ks_encrypt@ --- *
628 * Arguments: @keyset *ks@ = pointer to a keyset
629 * @buf *b@ = pointer to input buffer
630 * @buf *bb@ = pointer to output buffer
632 * Returns: Zero if OK, nonzero if the key needs replacing. If the
633 * encryption failed, the output buffer is broken and zero is
636 * Use: Encrypts a block of data using the key. Note that the `key
637 * ought to be replaced' notification is only ever given once
638 * for each key. Also note that this call forces a keyset to be
639 * used even if it's marked as not for data output.
642 extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
644 /* --- @ks_decrypt@ --- *
646 * Arguments: @keyset *ks@ = pointer to a keyset
647 * @buf *b@ = pointer to an input buffer
648 * @buf *bb@ = pointer to an output buffer
650 * Returns: Zero on success, or nonzero if there was some problem.
652 * Use: Attempts to decrypt a message using a given key. Note that
653 * requesting decryption with a key directly won't clear a
654 * marking that it's not for encryption.
657 extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/);
659 /* --- @ksl_free@ --- *
661 * Arguments: @keyset **ksroot@ = pointer to keyset list head
665 * Use: Frees (releases references to) all of the keys in a keyset.
668 extern void ksl_free(keyset **/*ksroot*/);
670 /* --- @ksl_link@ --- *
672 * Arguments: @keyset **ksroot@ = pointer to keyset list head
673 * @keyset *ks@ = pointer to a keyset
677 * Use: Links a keyset into a list. A keyset can only be on one list
678 * at a time. Bad things happen otherwise.
681 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
683 /* --- @ksl_prune@ --- *
685 * Arguments: @keyset **ksroot@ = pointer to keyset list head
689 * Use: Prunes the keyset list by removing keys which mustn't be used
693 extern void ksl_prune(keyset **/*ksroot*/);
695 /* --- @ksl_encrypt@ --- *
697 * Arguments: @keyset **ksroot@ = pointer to keyset list head
698 * @buf *b@ = pointer to input buffer
699 * @buf *bb@ = pointer to output buffer
701 * Returns: Nonzero if a new key is needed.
703 * Use: Encrypts a packet.
706 extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
708 /* --- @ksl_decrypt@ --- *
710 * Arguments: @keyset **ksroot@ = pointer to keyset list head
711 * @buf *b@ = pointer to input buffer
712 * @buf *bb@ = pointer to output buffer
714 * Returns: Nonzero if the packet couldn't be decrypted.
716 * Use: Decrypts a packet.
719 extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/);
721 /*----- Administration interface ------------------------------------------*/
723 /* --- @a_warn@ --- *
725 * Arguments: @const char *fmt@ = pointer to format string
726 * @...@ = other arguments
730 * Use: Informs all admin connections of a warning.
733 extern void a_warn(const char */*fmt*/, ...);
735 /* --- @a_create@ --- *
737 * Arguments: @int fd_in, fd_out@ = file descriptors to use
741 * Use: Creates a new admin connection.
744 extern void a_create(int /*fd_in*/, int /*fd_out*/);
746 /* --- @a_quit@ --- *
752 * Use: Shuts things down nicely.
755 extern void a_quit(void);
757 /* --- @a_daemon@ --- *
763 * Use: Informs the admin module that it's a daemon.
766 extern void a_daemon(void);
768 /* --- @a_init@ --- *
770 * Arguments: @const char *sock@ = socket name to create
774 * Use: Creates the admin listening socket.
777 extern void a_init(const char */*sock*/);
779 /*----- Peer management ---------------------------------------------------*/
781 /* --- @p_txstart@ --- *
783 * Arguments: @peer *p@ = pointer to peer block
784 * @unsigned msg@ = message type code
786 * Returns: A pointer to a buffer to write to.
788 * Use: Starts sending to a peer. Only one send can happen at a
792 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
794 /* --- @p_txend@ --- *
796 * Arguments: @peer *p@ = pointer to peer block
800 * Use: Sends a packet to the peer.
803 extern void p_txend(peer */*p*/);
807 * Arguments: @peer *p@ = pointer to peer block
808 * @buf *b@ = buffer containing incoming packet
812 * Use: Handles a packet which needs to be sent to a peer.
815 extern void p_tun(peer */*p*/, buf */*b*/);
817 /* --- @p_interval@ --- *
823 * Use: Called periodically to do tidying.
826 extern void p_interval(void);
828 /* --- @p_stats@ --- *
830 * Arguments: @peer *p@ = pointer to a peer block
832 * Returns: A pointer to the peer's statistics.
835 extern stats *p_stats(peer */*p*/);
837 /* --- @p_ifname@ --- *
839 * Arguments: @peer *p@ = pointer to a peer block
841 * Returns: A pointer to the peer's interface name.
844 extern const char *p_ifname(peer */*p*/);
846 /* --- @p_addr@ --- *
848 * Arguments: @peer *p@ = pointer to a peer block
850 * Returns: A pointer to the peer's address.
853 extern const addr *p_addr(peer */*p*/);
855 /* --- @p_init@ --- *
857 * Arguments: @unsigned port@ = port number to listen to
861 * Use: Initializes the peer system; creates the socket.
864 extern void p_init(unsigned /*port*/);
866 /* --- @p_port@ --- *
870 * Returns: Port number used for socket.
873 unsigned p_port(void);
875 /* --- @p_create@ --- *
877 * Arguments: @const char *name@ = name for this peer
878 * @struct sockaddr *sa@ = socket address of peer
879 * @size_t sz@ = size of socket address
881 * Returns: Pointer to the peer block, or null if it failed.
883 * Use: Creates a new named peer block. No peer is actually attached
887 extern peer *p_create(const char */*name*/,
888 struct sockaddr */*sa*/, size_t /*sz*/);
890 /* --- @p_name@ --- *
892 * Arguments: @peer *p@ = pointer to a peer block
894 * Returns: A pointer to the peer's name.
897 extern const char *p_name(peer */*p*/);
899 /* --- @p_find@ --- *
901 * Arguments: @const char *name@ = name to look up
903 * Returns: Pointer to the peer block, or null if not found.
905 * Use: Finds a peer by name.
908 extern peer *p_find(const char */*name*/);
910 /* --- @p_destroy@ --- *
912 * Arguments: @peer *p@ = pointer to a peer
916 * Use: Destroys a peer.
919 extern void p_destroy(peer */*p*/);
921 /* --- @p_first@, @p_next@ --- *
923 * Arguments: @peer *p@ = a peer block
925 * Returns: @peer_first@ returns the first peer in some ordering;
926 * @peer_next@ returns the peer following a given one in the
927 * same ordering. Null is returned for the end of the list.
930 extern peer *p_first(void);
931 extern peer *p_next(peer */*p*/);
933 /*----- Tunnel interface --------------------------------------------------*/
935 /* --- @tun_init@ --- *
941 * Use: Initializes the tunneling system. Maybe this will require
942 * opening file descriptors or something.
945 extern void tun_init(void);
947 /* --- @tun_create@ --- *
949 * Arguments: @tunnel *t@ = pointer to tunnel block
950 * @peer *p@ = pointer to peer block
952 * Returns: Zero if it worked, nonzero on failure.
954 * Use: Initializes a new tunnel.
957 extern int tun_create(tunnel */*t*/, peer */*p*/);
959 /* --- @tun_ifname@ --- *
961 * Arguments: @tunnel *t@ = pointer to tunnel block
963 * Returns: A pointer to the tunnel's interface name.
966 extern const char *tun_ifname(tunnel */*t*/);
968 /* --- @tun_inject@ --- *
970 * Arguments: @tunnel *t@ = pointer to tunnel block
971 * @buf *b@ = buffer to send
975 * Use: Injects a packet into the local network stack.
978 extern void tun_inject(tunnel */*t*/, buf */*b*/);
980 /* --- @tun_destroy@ --- *
982 * Arguments: @tunnel *t@ = pointer to tunnel block
986 * Use: Destroys a tunnel.
989 extern void tun_destroy(tunnel */*t*/);
991 /*----- Buffer handling ---------------------------------------------------*/
993 /* --- Useful macros --- */
995 #define BBASE(b) ((b)->base)
996 #define BLIM(b) ((b)->limit)
997 #define BCUR(b) ((b)->p)
998 #define BSZ(b) ((b)->limit - (b)->base)
999 #define BLEN(b) ((b)->p - (b)->base)
1000 #define BLEFT(b) ((b)->limit - (b)->p)
1001 #define BSTEP(b, sz) ((b)->p += (sz))
1002 #define BBAD(b) ((b)->f & BF_BROKEN)
1003 #define BOK(b) (!BBAD(b))
1005 #define BENSURE(b, sz) \
1006 (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0)
1008 /* --- @buf_init@ --- *
1010 * Arguments: @buf *b@ = pointer to a buffer block
1011 * @void *p@ = pointer to a buffer
1012 * @size_t sz@ = size of the buffer
1016 * Use: Initializes the buffer block appropriately.
1019 extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/);
1021 /* --- @buf_break@ --- *
1023 * Arguments: @buf *b@ = pointer to a buffer block
1025 * Returns: Some negative value.
1027 * Use: Marks a buffer as broken.
1030 extern int buf_break(buf */*b*/);
1032 /* --- @buf_flip@ --- *
1034 * Arguments: @buf *b@ = pointer to a buffer block
1038 * Use: Flips a buffer so that if you've just been writing to it,
1039 * you can now read from the bit you've written.
1042 extern void buf_flip(buf */*b*/);
1044 /* --- @buf_ensure@ --- *
1046 * Arguments: @buf *b@ = pointer to a buffer block
1047 * @size_t sz@ = size of data wanted
1049 * Returns: Zero if it worked, nonzero if there wasn't enough space.
1051 * Use: Ensures that there are @sz@ bytes still in the buffer.
1054 extern int buf_ensure(buf */*b*/, size_t /*sz*/);
1056 /* --- @buf_get@ --- *
1058 * Arguments: @buf *b@ = pointer to a buffer block
1059 * @size_t sz@ = size of the buffer
1061 * Returns: Pointer to the place in the buffer.
1063 * Use: Reserves a space in the buffer of the requested size, and
1064 * returns its start address.
1067 extern void *buf_get(buf */*b*/, size_t /*sz*/);
1069 /* --- @buf_put@ --- *
1071 * Arguments: @buf *b@ = pointer to a buffer block
1072 * @const void *p@ = pointer to a buffer
1073 * @size_t sz@ = size of the buffer
1075 * Returns: Zero if it worked, nonzero if there wasn't enough space.
1077 * Use: Fetches data from some place and puts it in the buffer
1080 extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/);
1082 /* --- @buf_getbyte@ --- *
1084 * Arguments: @buf *b@ = pointer to a buffer block
1086 * Returns: A byte, or less than zero if there wasn't a byte there.
1088 * Use: Gets a single byte from a buffer.
1091 extern int buf_getbyte(buf */*b*/);
1093 /* --- @buf_putbyte@ --- *
1095 * Arguments: @buf *b@ = pointer to a buffer block
1096 * @int ch@ = byte to write
1098 * Returns: Zero if OK, nonzero if there wasn't enough space.
1100 * Use: Puts a single byte in a buffer.
1103 extern int buf_putbyte(buf */*b*/, int /*ch*/);
1105 /* --- @buf_getu16@ --- *
1107 * Arguments: @buf *b@ = pointer to a buffer block
1108 * @uint16 *w@ = where to put the word
1110 * Returns: Zero if OK, or nonzero if there wasn't a word there.
1112 * Use: Gets a 16-bit word from a buffer.
1115 extern int buf_getu16(buf */*b*/, uint16 */*w*/);
1117 /* --- @buf_putu16@ --- *
1119 * Arguments: @buf *b@ = pointer to a buffer block
1120 * @uint16 w@ = word to write
1122 * Returns: Zero if OK, nonzero if there wasn't enough space.
1124 * Use: Puts a 16-but word in a buffer.
1127 extern int buf_putu16(buf */*b*/, uint16 /*w*/);
1129 /* --- @buf_getu32@ --- *
1131 * Arguments: @buf *b@ = pointer to a buffer block
1132 * @uint32 *w@ = where to put the word
1134 * Returns: Zero if OK, or nonzero if there wasn't a word there.
1136 * Use: Gets a 32-bit word from a buffer.
1139 extern int buf_getu32(buf */*b*/, uint32 */*w*/);
1141 /* --- @buf_putu32@ --- *
1143 * Arguments: @buf *b@ = pointer to a buffer block
1144 * @uint32 w@ = word to write
1146 * Returns: Zero if OK, nonzero if there wasn't enough space.
1148 * Use: Puts a 32-but word in a buffer.
1151 extern int buf_putu32(buf */*b*/, uint32 /*w*/);
1153 /* --- @buf_getmp@ --- *
1155 * Arguments: @buf *b@ = pointer to a buffer block
1157 * Returns: A multiprecision integer, or null if there wasn't one there.
1159 * Use: Gets a multiprecision integer from a buffer.
1162 extern mp *buf_getmp(buf */*b*/);
1164 /* --- @buf_putmp@ --- *
1166 * Arguments: @buf *b@ = pointer to a buffer block
1167 * @mp *m@ = a multiprecision integer
1169 * Returns: Zero if it worked, nonzero if there wasn't enough space.
1171 * Use: Puts a multiprecision integer to a buffer.
1174 extern int buf_putmp(buf */*b*/, mp */*m*/);
1176 /*----- Other handy utilities ---------------------------------------------*/
1178 /* --- @mpstr@ --- *
1180 * Arguments: @mp *m@ = a multiprecision integer
1182 * Returns: A pointer to the integer's textual representation.
1184 * Use: Converts a multiprecision integer to a string. Corrupts
1188 extern const char *mpstr(mp */*m*/);
1190 /* --- @timestr@ --- *
1192 * Arguments: @time_t t@ = a time to convert
1194 * Returns: A pointer to a textual representation of the time.
1196 * Use: Converts a time to a textual representation. Corrupts
1200 extern const char *timestr(time_t /*t*/);
1202 /*----- That's all, folks -------------------------------------------------*/