3 * Main header file for TrIPE
5 * (c) 2001 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Trivial IP Encryption (TrIPE).
12 * TrIPE is free software: you can redistribute it and/or modify it under
13 * the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 3 of the License, or (at your
15 * option) any later version.
17 * TrIPE is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE. If not, see <https://www.gnu.org/licenses/>.
33 /*----- Header files ------------------------------------------------------*/
49 #include <sys/types.h>
56 #include <sys/socket.h>
58 #include <netinet/in.h>
59 #include <arpa/inet.h>
65 #include <mLib/alloc.h>
66 #include <mLib/arena.h>
67 #include <mLib/base64.h>
68 #include <mLib/bres.h>
69 #include <mLib/codec.h>
70 #include <mLib/daemonize.h>
71 #include <mLib/dstr.h>
73 #include <mLib/fdflags.h>
74 #include <mLib/fdpass.h>
75 #include <mLib/fwatch.h>
76 #include <mLib/hash.h>
77 #include <mLib/macros.h>
78 #include <mLib/mdup.h>
79 #include <mLib/mdwopt.h>
80 #include <mLib/quis.h>
81 #include <mLib/report.h>
83 #include <mLib/selbuf.h>
87 #include <mLib/trace.h>
89 #include <mLib/versioncmp.h>
91 #include <catacomb/buf.h>
92 #include <catacomb/ct.h>
94 #include <catacomb/chacha.h>
95 #include <catacomb/gcipher.h>
96 #include <catacomb/gmac.h>
97 #include <catacomb/grand.h>
98 #include <catacomb/key.h>
99 #include <catacomb/paranoia.h>
100 #include <catacomb/poly1305.h>
101 #include <catacomb/salsa20.h>
103 #include <catacomb/noise.h>
104 #include <catacomb/rand.h>
106 #include <catacomb/mp.h>
107 #include <catacomb/mpmont.h>
108 #include <catacomb/mprand.h>
109 #include <catacomb/dh.h>
110 #include <catacomb/ec.h>
111 #include <catacomb/ec-raw.h>
112 #include <catacomb/ec-keys.h>
113 #include <catacomb/x25519.h>
114 #include <catacomb/x448.h>
117 #include "protocol.h"
123 /*----- Magic numbers -----------------------------------------------------*/
125 /* --- Trace flags --- */
133 #define T_KEYEXCH 64u
134 #define T_KEYMGMT 128u
136 /* T_PRIVSEP in priv.h */
142 #define SEC(n) (n##u)
143 #define MIN(n) (n##u * 60u)
144 #define F_2P32 (65536.0*65536.0)
145 #define MEG(n) (n##ul * 1024ul * 1024ul)
147 /* --- Timing parameters --- */
149 #define T_EXP MIN(60) /* Expiry time for a key */
150 #define T_REGEN MIN(40) /* Regeneration time for a key */
152 #define T_VALID SEC(20) /* Challenge validity period */
153 #define T_RETRYMIN SEC(2) /* Minimum retry interval */
154 #define T_RETRYMAX MIN(5) /* Maximum retry interval */
155 #define T_RETRYGROW (5.0/4.0) /* Retry interval growth factor */
157 #define T_WOBBLE (1.0/3.0) /* Relative timer randomness */
159 /* --- Other things --- */
161 #define PKBUFSZ 65536
163 /*----- Cipher selections -------------------------------------------------*/
165 typedef struct keyset keyset;
166 typedef struct algswitch algswitch;
167 typedef struct kdata kdata;
168 typedef struct admin admin;
170 typedef struct dhgrp {
171 const struct dhops *ops;
175 typedef struct dhsc dhsc;
176 typedef struct dhge dhge;
179 DHFMT_STD, /* Fixed-width format, suitable for encryption */
180 DHFMT_HASH, /* Deterministic format, suitable for hashing */
181 DHFMT_VAR /* Variable-width-format, mostly a bad idea */
184 typedef struct deriveargs {
185 const char *what; /* Operation name (hashed) */
186 unsigned f; /* Flags */
187 #define DF_IN 1u /* Make incoming key */
188 #define DF_OUT 2u /* Make outgoing key */
189 const gchash *hc; /* Hash class */
190 const octet *k; /* Pointer to contributions */
191 size_t x, y, z; /* Markers in contributions */
194 typedef struct bulkalgs {
195 const struct bulkops *ops;
198 typedef struct bulkctx {
199 const struct bulkops *ops;
202 typedef struct bulkchal {
203 const struct bulkops *ops;
207 typedef struct dhops {
210 int (*ldpriv)(key_file */*kf*/, key */*k*/, key_data */*d*/,
211 kdata */*kd*/, dstr */*t*/, dstr */*e*/);
212 /* Load a private key from @d@, storing the data in @kd@. The key's
213 * file and key object are in @kf@ and @k@, mostly in case its
214 * attributes are interesting; the key tag is in @t@; errors are
215 * reported by writing tokens to @e@ and returning nonzero.
218 int (*ldpub)(key_file */*kf*/, key */*k*/, key_data */*d*/,
219 kdata */*kd*/, dstr */*t*/, dstr */*e*/);
220 /* Load a public key from @d@, storing the data in @kd@. The key's
221 * file and key object are in @kf@ and @k@, mostly in case its
222 * attributes are interesting; the key tag is in @t@; errors are
223 * reported by writing tokens to @e@ and returning nonzero.
226 const char *(*checkgrp)(const dhgrp */*g*/);
227 /* Check that the group is valid; return null on success, or an error
231 void (*grpinfo)(const dhgrp */*g*/, admin */*a*/);
232 /* Report on the group to an admin client. */
234 T( void (*tracegrp)(const dhgrp */*g*/); )
235 /* Trace a description of the group. */
237 int (*samegrpp)(const dhgrp */*g*/, const dhgrp */*gg*/);
238 /* Return nonzero if the two group objects represent the same
242 void (*freegrp)(dhgrp */*g*/);
243 /* Free a group and the resources it holds. */
245 dhsc *(*ldsc)(const dhgrp */*g*/, const void */*p*/, size_t /*sz*/);
246 /* Load a scalar from @p@, @sz@ and return it. Return null on
250 int (*stsc)(const dhgrp */*g*/,
251 void */*p*/, size_t /*sz*/, const dhsc */*x*/);
252 /* Store a scalar at @p@, @sz@. Return nonzero on error. */
254 dhsc *(*randsc)(const dhgrp */*g*/);
255 /* Return a random scalar. */
257 T( const char *(*scstr)(const dhgrp */*g*/, const dhsc */*x*/); )
258 /* Return a human-readable representation of @x@; @buf_t@ may be used
262 void (*freesc)(const dhgrp */*g*/, dhsc */*x*/);
263 /* Free a scalar and the resources it holds. */
265 dhge *(*ldge)(const dhgrp */*g*/, buf */*b*/, int /*fmt*/);
266 /* Load a group element from @b@, encoded using format @fmt@. Return
270 int (*stge)(const dhgrp */*g*/, buf */*b*/,
271 const dhge */*Y*/, int /*fmt*/);
272 /* Store a group element in @b@, encoded using format @fmt@. Return
276 int (*checkge)(const dhgrp */*h*/, const dhge */*Y*/);
277 /* Check a group element for validity. Return zero if everything
278 * checks out; nonzero on failure.
281 int (*eq)(const dhgrp */*g*/, const dhge */*Y*/, const dhge */*Z*/);
282 /* Return nonzero if @Y@ and @Z@ are equal. */
284 dhge *(*mul)(const dhgrp */*g*/, const dhsc */*x*/, const dhge */*Y*/);
285 /* Multiply a group element by a scalar, resulting in a shared-secret
286 * group element. If @y@ is null, then multiply the well-known
290 T( const char *(*gestr)(const dhgrp */*g*/, const dhge */*Y*/); )
291 /* Return a human-readable representation of @Y@; @buf_t@ may be used
295 void (*freege)(const dhgrp */*g*/, dhge */*Y*/);
296 /* Free a group element and the resources it holds. */
300 typedef struct bulkops {
303 bulkalgs *(*getalgs)(const algswitch */*asw*/, dstr */*e*/,
304 key_file */*kf*/, key */*k*/);
305 /* Determine algorithms to use and return a @bulkalgs@ object
306 * representing the decision. On error, write tokens to @e@ and
310 T( void (*tracealgs)(const bulkalgs */*a*/); )
311 /* Write trace information about the algorithm selection. */
313 int (*checkalgs)(bulkalgs */*a*/, const algswitch */*asw*/, dstr */*e*/);
314 /* Check that the algorithms in @a@ and @asw@ are acceptable. On
315 * error, write tokens to @e@ and return @-1@; otherwise return zero.
318 int (*samealgsp)(const bulkalgs */*a*/, const bulkalgs */*aa*/);
319 /* If @a@ and @aa@ represent the same algorithm selection, return
320 * nonzero; if not, return zero.
323 void (*alginfo)(const bulkalgs */*a*/, admin */*adm*/);
324 /* Report on the algorithm selection to an admin client: call
325 * @a_info@ with appropriate key-value pairs.
328 size_t (*overhead)(const bulkalgs */*a*/);
329 /* Return the per-packet overhead of the bulk transform, in bytes. */
331 size_t (*expsz)(const bulkalgs */*a*/);
332 /* Return the total size limit for the bulk transform, in bytes,
333 * after which the keys must no longer be used.
336 bulkctx *(*genkeys)(const bulkalgs */*a*/, const deriveargs */*a*/);
337 /* Generate session keys and construct and return an appropriate
338 * context for using them. The offsets @a->x@, @a->y@ and @a->z@
339 * separate the key material into three parts. Between @a->k@ and
340 * @a->k + a->x@ is `my' contribution to the key material; between
341 * @a->k + a->x@ and @a->k + a->y@ is `your' contribution; and
342 * between @a->k + a->y@ and @a->k + a->z@ is a shared value we made
343 * together. These are used to construct (up to) two collections of
344 * symmetric keys: one for outgoing messages, the other for incoming
345 * messages. If @a->x == 0@ (or @a->y == a->x@) then my (or your)
346 * contribution is omitted.
349 bulkchal *(*genchal)(const bulkalgs */*a*/);
350 /* Construct and return a challenge issuing and verification
351 * context with a fresh random key.
354 void (*freealgs)(bulkalgs */*a*/);
355 /* Release an algorithm selection object. (Associated bulk
356 * encryption contexts and challenge contexts may still exist and
357 * must remain valid.)
360 int (*encrypt)(bulkctx */*bc*/, unsigned /*ty*/,
361 buf */*b*/, buf */*bb*/, uint32 /*seq*/);
362 /* Encrypt the packet in @b@, with type @ty@ (which doesn't need
363 * encoding separately) and sequence number @seq@ (which must be
364 * recoverable by @decrypt@), and write the result to @bb@. On
365 * error, return a @KSERR_...@ code and/or break the output buffer.
368 int (*decrypt)(bulkctx */*bc*/, unsigned /*ty*/,
369 buf */*b*/, buf */*bb*/, uint32 */*seq*/);
370 /* Decrypt the packet in @b@, with type @ty@, writing the result to
371 * @bb@ and storing the incoming (claimed) sequence number in @seq@.
372 * On error, return a @KSERR_...@ code.
375 void (*freectx)(bulkctx */*a*/);
376 /* Release a bulk encryption context and the resources it holds. */
378 int (*chaltag)(bulkchal */*bc*/, const void */*m*/, size_t /*msz*/,
379 uint32 /*seq*/, void */*t*/);
380 /* Calculate a tag for the challenge in @m@, @msz@, with the sequence
381 * number @seq@, and write it to @t@. Return @-1@ on error, zero on
385 int (*chalvrf)(bulkchal */*bc*/, const void */*m*/, size_t /*msz*/,
386 uint32 /*seq*/, const void */*t*/);
387 /* Check the tag @t@ on @m@, @msz@ and @seq@: return zero if the tag
388 * is OK, nonzero if it's bad.
391 void (*freechal)(bulkchal */*bc*/);
392 /* Release a challenge context and the resources it holds. */
397 const gchash *h; size_t hashsz; /* Hash function */
398 const gccipher *mgf; /* Mask-generation function */
399 bulkalgs *bulk; /* Bulk crypto algorithms */
403 unsigned ref; /* Reference counter */
404 struct knode *kn; /* Pointer to cache entry */
405 char *tag; /* Full tag name of the key */
406 dhgrp *grp; /* The group we work in */
407 dhsc *k; /* The private key (or null) */
408 dhge *K; /* The public key */
409 time_t t_exp; /* Expiry time of the key */
410 algswitch algs; /* Collection of algorithms */
413 typedef struct knode {
414 sym_base _b; /* Symbol table intrusion */
415 unsigned f; /* Various flags */
416 #define KNF_BROKEN 1u /* Don't use this key any more */
417 struct keyhalf *kh; /* Pointer to the home keyhalf */
418 kdata *kd; /* Pointer to the key data */
421 #define MAXHASHSZ 64 /* Largest possible hash size */
423 #define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s))
425 extern const dhops dhtab[];
426 extern const bulkops bulktab[];
428 /*----- Data structures ---------------------------------------------------*/
430 /* --- Socket addresses --- *
432 * A magic union of supported socket addresses.
437 struct sockaddr_in sin;
440 /* --- Mapping keyed on addresses --- */
442 typedef struct addrmap {
447 typedef struct addrmap_base {
452 /* --- Sequence number checking --- */
454 typedef struct seqwin {
455 uint32 seq; /* First acceptable input sequence */
456 uint32 win; /* Window of acceptable numbers */
459 #define SEQ_WINSZ 32 /* Bits in sequence number window */
461 /* --- A symmetric keyset --- *
463 * A keyset contains a set of symmetric keys for encrypting and decrypting
464 * packets. Keysets are stored in a list, sorted in reverse order of
465 * creation, so that the most recent keyset (the one most likely to be used)
468 * Each keyset has a time limit and a data limit. The keyset is destroyed
469 * when either it has existed for too long, or it has been used to encrypt
470 * too much data. New key exchanges are triggered when keys are close to
474 enum { DIR_IN, DIR_OUT, NDIR };
477 struct keyset *next; /* Next active keyset in the list */
478 unsigned ref; /* Reference count for keyset */
479 struct peer *p; /* Pointer to peer structure */
480 time_t t_exp; /* Expiry time for this keyset */
481 unsigned long sz_exp, sz_regen; /* Data limits for the keyset */
482 T( unsigned seq; ) /* Sequence number for tracing */
483 unsigned f; /* Various useful flags */
484 bulkctx *bulk; /* Bulk crypto transform */
485 uint32 oseq; /* Outbound sequence number */
486 seqwin iseq; /* Inbound sequence number */
489 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
490 #define KSF_LINK 2u /* Key is in a linked list */
492 #define KSERR_REGEN -1 /* Regenerate keys */
493 #define KSERR_NOKEYS -2 /* No keys left */
494 #define KSERR_DECRYPT -3 /* Unable to decrypt message */
495 #define KSERR_SEQ -4 /* Incorrect sequence number */
496 #define KSERR_MALFORMED -5 /* Input ciphertext is broken */
498 /* --- Key exchange --- *
500 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
501 * Protocol has a number of desirable features (e.g., perfect forward
502 * secrecy, and zero-knowledge authentication) which make it attractive for
503 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
507 typedef struct retry {
508 double t; /* Current retry time */
513 typedef struct kxchal {
514 struct keyexch *kx; /* Pointer back to key exchange */
515 dhge *C; /* Responder's challenge */
516 dhge *R; /* My reply to the challenge */
517 keyset *ks; /* Pointer to temporary keyset */
518 unsigned f; /* Various useful flags */
519 sel_timer t; /* Response timer for challenge */
520 retry rs; /* Retry state */
521 octet hc[MAXHASHSZ]; /* Hash of his challenge */
522 octet ck[MAXHASHSZ]; /* His magical check value */
523 octet hswrq_in[MAXHASHSZ]; /* Inbound switch request message */
524 octet hswok_in[MAXHASHSZ]; /* Inbound switch confirmation */
525 octet hswrq_out[MAXHASHSZ]; /* Outbound switch request message */
526 octet hswok_out[MAXHASHSZ]; /* Outbound switch confirmation */
529 typedef struct keyexch {
530 struct peer *p; /* Pointer back to the peer */
531 kdata *kpriv; /* Private key and related info */
532 kdata *kpub; /* Peer's public key */
533 keyset **ks; /* Peer's list of keysets */
534 unsigned f; /* Various useful flags */
535 unsigned s; /* Current state in exchange */
536 sel_timer t; /* Timer for next exchange */
537 retry rs; /* Retry state */
538 dhsc *a; /* My temporary secret */
539 dhge *C; /* My challenge */
540 dhge *RX; /* The expected response */
541 unsigned nr; /* Number of extant responses */
542 time_t t_valid; /* When this exchange goes bad */
543 octet hc[MAXHASHSZ]; /* Hash of my challenge */
544 kxchal *r[KX_NCHAL]; /* Array of challenges */
547 #define KXF_TIMER 1u /* Waiting for a timer to go off */
548 #define KXF_DEAD 2u /* The key-exchanger isn't up */
549 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
550 #define KXF_CORK 8u /* Don't send anything yet */
553 KXS_DEAD, /* Uninitialized state (magical) */
554 KXS_CHAL, /* Main answer-challenges state */
555 KXS_COMMIT, /* Committed: send switch request */
556 KXS_SWITCH /* Switched: send confirmation */
559 /* --- Tunnel structure --- *
561 * Used to maintain system-specific information about the tunnel interface.
564 typedef struct tunnel tunnel;
567 typedef struct tunnel_ops {
568 const char *name; /* Name of this tunnel driver */
569 unsigned flags; /* Various interesting flags */
570 #define TUNF_PRIVOPEN 1u /* Need helper to open file */
571 void (*init)(void); /* Initializes the system */
572 tunnel *(*create)(struct peer */*p*/, int /*fd*/, char **/*ifn*/);
573 /* Initializes a new tunnel */
574 void (*setifname)(tunnel */*t*/, const char */*ifn*/);
575 /* Notifies ifname change */
576 void (*inject)(tunnel */*t*/, buf */*b*/); /* Sends packet through if */
577 void (*destroy)(tunnel */*t*/); /* Destroys a tunnel */
580 #ifndef TUN_INTERNALS
581 struct tunnel { const tunnel_ops *ops; };
584 /* --- Peer statistics --- *
586 * Contains various interesting and not-so-interesting statistics about a
587 * peer. This is updated by various parts of the code. The format of the
588 * structure isn't considered private, and @p_stats@ returns a pointer to the
589 * statistics block for a given peer.
592 typedef struct stats {
593 unsigned long sz_in, sz_out; /* Size of all data in and out */
594 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
595 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
596 time_t t_start, t_last, t_kx; /* Time peer created, last pk, kx */
597 unsigned long n_reject; /* Number of rejected packets */
598 unsigned long n_in, n_out; /* Number of packets in and out */
599 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
600 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
603 /* --- Peer structure --- *
605 * The main structure which glues everything else together.
608 typedef struct peerspec {
609 char *name; /* Peer's name */
610 char *privtag; /* Private key tag */
611 char *tag; /* Public key tag */
612 const tunnel_ops *tops; /* Tunnel operations */
613 unsigned long t_ka; /* Keep alive interval */
614 addr sa; /* Socket address to speak to */
615 unsigned f; /* Flags for the peer */
616 #define PSF_KXMASK 255u /* Key-exchange flags to set */
617 #define PSF_MOBILE 256u /* Address may change rapidly */
620 typedef struct peer_byname {
625 typedef struct peer_byaddr {
630 typedef struct peer {
631 peer_byname *byname; /* Lookup-by-name block */
632 peer_byaddr *byaddr; /* Lookup-by-address block */
633 struct ping *pings; /* Pings we're waiting for */
634 peerspec spec; /* Specifications for this peer */
635 tunnel *t; /* Tunnel for local packets */
636 char *ifname; /* Interface name for tunnel */
637 keyset *ks; /* List head for keysets */
638 buf b; /* Buffer for sending packets */
639 stats st; /* Statistics */
640 keyexch kx; /* Key exchange protocol block */
641 sel_timer tka; /* Timer for keepalives */
644 typedef struct peer_iter { sym_iter i; } peer_iter;
646 typedef struct ping {
647 struct ping *next, *prev; /* Links to next and previous */
648 peer *p; /* Peer so we can free it */
649 unsigned msg; /* Kind of response expected */
650 uint32 id; /* Id so we can recognize response */
651 octet magic[32]; /* Some random data */
652 sel_timer t; /* Timeout for ping */
653 void (*func)(int /*rc*/, void */*arg*/); /* Function to call when done */
654 void *arg; /* Argument for callback */
665 /* --- Admin structure --- */
667 #define OBUFSZ 16384u
669 typedef struct obuf {
670 struct obuf *next; /* Next buffer in list */
671 char *p_in, *p_out; /* Pointers into the buffer */
672 char buf[OBUFSZ]; /* The actual buffer */
675 typedef struct oqueue {
676 obuf *hd, *tl; /* Head and tail pointers */
681 typedef struct admin_bgop {
682 struct admin_bgop *next, *prev; /* Links to next and previous */
683 struct admin *a; /* Owner job */
684 char *tag; /* Tag string for messages */
685 void (*cancel)(struct admin_bgop *); /* Destructor function */
688 typedef struct admin_resop {
689 admin_bgop bg; /* Background operation header */
690 char *addr; /* Hostname to be resolved */
691 bres_client r; /* Background resolver task */
692 sel_timer t; /* Timer for resolver */
693 addr sa; /* Socket address */
694 size_t sasz; /* Socket address size */
695 void (*func)(struct admin_resop *, int); /* Handler */
698 enum { ARES_OK, ARES_FAIL };
700 typedef struct admin_addop {
701 admin_resop r; /* Name resolution header */
702 peerspec peer; /* Peer pending creation */
705 typedef struct admin_pingop {
706 admin_bgop bg; /* Background operation header */
707 ping ping; /* Ping pending response */
708 struct timeval pingtime; /* Time last ping was sent */
711 typedef struct admin_service {
712 sym_base _b; /* Hash table base structure */
713 char *version; /* The provided version */
714 struct admin *prov; /* Which client provides me */
715 struct admin_service *next, *prev; /* Client's list of services */
718 typedef struct admin_svcop {
719 admin_bgop bg; /* Background operation header */
720 struct admin *prov; /* Client servicing this job */
721 unsigned index; /* This job's index */
722 struct admin_svcop *next, *prev; /* Links for provider's jobs */
725 typedef struct admin_jobentry {
726 unsigned short seq; /* Zero if unused */
728 admin_svcop *op; /* Operation, if slot in use, ... */
729 uint32 next; /* ... or index of next free slot */
733 typedef struct admin_jobtable {
734 uint32 n, sz; /* Used slots and table size */
735 admin_svcop *active; /* List of active jobs */
736 uint32 free; /* Index of first free slot */
737 admin_jobentry *v; /* And the big array of entries */
741 struct admin *next, *prev; /* Links to next and previous */
742 unsigned f; /* Various useful flags */
743 unsigned ref; /* Reference counter */
745 unsigned seq; /* Sequence number for tracing */
747 oqueue out; /* Output buffer list */
748 oqueue delay; /* Delayed output buffer list */
749 admin_bgop *bg; /* Backgrounded operations */
750 admin_service *svcs; /* Which services I provide */
751 admin_jobtable j; /* Table of outstanding jobs */
752 selbuf b; /* Line buffer for commands */
753 sel_file w; /* Selector for write buffering */
756 #define AF_DEAD 1u /* Destroy this admin block */
757 #define AF_CLOSE 2u /* Client closed connection */
758 #define AF_NOTE 4u /* Catch notifications */
759 #define AF_WARN 8u /* Catch warning messages */
761 # define AF_TRACE 16u /* Catch tracing */
763 #define AF_FOREGROUND 32u /* Quit server when client closes */
766 # define AF_ALLMSGS (AF_NOTE | AF_TRACE | AF_WARN)
768 # define AF_ALLMSGS (AF_NOTE | AF_WARN)
771 /*----- Global variables --------------------------------------------------*/
773 extern sel_state sel; /* Global I/O event state */
774 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ], buf_u[PKBUFSZ];
775 extern const tunnel_ops *tunnels[]; /* Table of tunnels (0-term) */
776 extern const tunnel_ops *tun_default; /* Default tunnel to use */
777 extern kdata *master; /* Default private key */
778 extern const char *tag_priv; /* Default private key tag */
781 extern const trace_opt tr_opts[]; /* Trace options array */
782 extern unsigned tr_flags; /* Trace options flags */
785 /*----- Other macros ------------------------------------------------------*/
788 do { rand_quick(RAND_GLOBAL); noise_timer(RAND_GLOBAL); } while (0)
790 /*----- Key management ----------------------------------------------------*/
792 /* --- @km_init@ --- *
794 * Arguments: @const char *privkr@ = private keyring file
795 * @const char *pubkr@ = public keyring file
796 * @const char *ptag@ = default private-key tag
800 * Use: Initializes the key-management machinery, loading the
801 * keyrings and so on.
804 extern void km_init(const char */*privkr*/, const char */*pubkr*/,
805 const char */*ptag*/);
807 /* --- @km_reload@ --- *
811 * Returns: Zero if OK, nonzero to force reloading of keys.
813 * Use: Checks the keyrings to see if they need reloading.
816 extern int km_reload(void);
818 /* --- @km_findpub@, @km_findpriv@ --- *
820 * Arguments: @const char *tag@ = key tag to load
822 * Returns: Pointer to the kdata object if successful, or null on error.
824 * Use: Fetches a public or private key from the keyring.
827 extern kdata *km_findpub(const char */*tag*/);
828 extern kdata *km_findpriv(const char */*tag*/);
830 /* --- @km_samealgsp@ --- *
832 * Arguments: @const kdata *kdx, *kdy@ = two key data objects
834 * Returns: Nonzero if their two algorithm selections are the same.
836 * Use: Checks sameness of algorithm selections: used to ensure that
837 * peers are using sensible algorithms.
840 extern int km_samealgsp(const kdata */*kdx*/, const kdata */*kdy*/);
842 /* --- @km_ref@ --- *
844 * Arguments: @kdata *kd@ = pointer to the kdata object
848 * Use: Claim a new reference to a kdata object.
851 extern void km_ref(kdata */*kd*/);
853 /* --- @km_unref@ --- *
855 * Arguments: @kdata *kd@ = pointer to the kdata object
859 * Use: Releases a reference to a kdata object.
862 extern void km_unref(kdata */*kd*/);
864 /* --- @km_tag@ --- *
866 * Arguments: @kdata *kd@ - pointer to the kdata object
868 * Returns: A pointer to the short tag by which the kdata was loaded.
871 extern const char *km_tag(kdata */*kd*/);
873 /*----- Key exchange ------------------------------------------------------*/
875 /* --- @kx_start@ --- *
877 * Arguments: @keyexch *kx@ = pointer to key exchange context
878 * @int forcep@ = nonzero to ignore the quiet timer
882 * Use: Stimulates a key exchange. If a key exchage is in progress,
883 * a new challenge is sent (unless the quiet timer forbids
884 * this); if no exchange is in progress, one is commenced.
887 extern void kx_start(keyexch */*kx*/, int /*forcep*/);
889 /* --- @kx_message@ --- *
891 * Arguments: @keyexch *kx@ = pointer to key exchange context
892 * @unsigned msg@ = the message code
893 * @buf *b@ = pointer to buffer containing the packet
897 * Use: Reads a packet containing key exchange messages and handles
901 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
903 /* --- @kx_free@ --- *
905 * Arguments: @keyexch *kx@ = pointer to key exchange context
909 * Use: Frees everything in a key exchange context.
912 extern void kx_free(keyexch */*kx*/);
914 /* --- @kx_newkeys@ --- *
916 * Arguments: @keyexch *kx@ = pointer to key exchange context
920 * Use: Informs the key exchange module that its keys may have
921 * changed. If fetching the new keys fails, the peer will be
922 * destroyed, we log messages and struggle along with the old
926 extern void kx_newkeys(keyexch */*kx*/);
928 /* --- @kx_setup@ --- *
930 * Arguments: @keyexch *kx@ = pointer to key exchange context
931 * @peer *p@ = pointer to peer context
932 * @keyset **ks@ = pointer to keyset list
933 * @unsigned f@ = various useful flags
935 * Returns: Zero if OK, nonzero if it failed.
937 * Use: Initializes a key exchange module. The module currently
938 * contains no keys, and will attempt to initiate a key
942 extern int kx_setup(keyexch */*kx*/, peer */*p*/,
943 keyset **/*ks*/, unsigned /*f*/);
945 /*----- Keysets and symmetric cryptography --------------------------------*/
947 /* --- @ks_drop@ --- *
949 * Arguments: @keyset *ks@ = pointer to a keyset
953 * Use: Decrements a keyset's reference counter. If the counter hits
954 * zero, the keyset is freed.
957 extern void ks_drop(keyset */*ks*/);
959 /* --- @ks_gen@ --- *
961 * Arguments: @deriveargs *a@ = key derivation parameters (modified)
962 * @peer *p@ = pointer to peer information
964 * Returns: A pointer to the new keyset.
966 * Use: Derives a new keyset from the given key material. This will
967 * set the @what@, @f@, and @hc@ members in @*a@; other members
968 * must be filled in by the caller.
970 * The new key is marked so that it won't be selected for output
971 * by @ksl_encrypt@. You can still encrypt data with it by
972 * calling @ks_encrypt@ directly.
975 extern keyset *ks_gen(deriveargs */*a*/, peer */*p*/);
977 /* --- @ks_activate@ --- *
979 * Arguments: @keyset *ks@ = pointer to a keyset
983 * Use: Activates a keyset, so that it can be used for encrypting
987 extern void ks_activate(keyset */*ks*/);
989 /* --- @ks_encrypt@ --- *
991 * Arguments: @keyset *ks@ = pointer to a keyset
992 * @unsigned ty@ = message type
993 * @buf *b@ = pointer to input buffer
994 * @buf *bb@ = pointer to output buffer
996 * Returns: Zero if successful; @KSERR_REGEN@ if we should negotiate a
997 * new key; @KSERR_NOKEYS@ if the key is not usable. Also
998 * returns zero if there was insufficient buffer (but the output
999 * buffer is broken in this case).
1001 * Use: Encrypts a block of data using the key. Note that the `key
1002 * ought to be replaced' notification is only ever given once
1003 * for each key. Also note that this call forces a keyset to be
1004 * used even if it's marked as not for data output.
1006 * The encryption transform is permitted to corrupt @buf_u@ for
1007 * its own purposes. Neither the source nor destination should
1008 * be within @buf_u@; and callers mustn't expect anything stored
1009 * in @buf_u@ to still
1012 extern int ks_encrypt(keyset */*ks*/, unsigned /*ty*/,
1013 buf */*b*/, buf */*bb*/);
1015 /* --- @ks_decrypt@ --- *
1017 * Arguments: @keyset *ks@ = pointer to a keyset
1018 * @unsigned ty@ = expected type code
1019 * @buf *b@ = pointer to an input buffer
1020 * @buf *bb@ = pointer to an output buffer
1022 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
1023 * zero if there was insufficient buffer (but the output buffer
1024 * is broken in this case).
1026 * Use: Attempts to decrypt a message using a given key. Note that
1027 * requesting decryption with a key directly won't clear a
1028 * marking that it's not for encryption.
1030 * The decryption transform is permitted to corrupt @buf_u@ for
1031 * its own purposes. Neither the source nor destination should
1032 * be within @buf_u@; and callers mustn't expect anything stored
1033 * in @buf_u@ to still
1036 extern int ks_decrypt(keyset */*ks*/, unsigned /*ty*/,
1037 buf */*b*/, buf */*bb*/);
1039 /* --- @ksl_free@ --- *
1041 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1045 * Use: Frees (releases references to) all of the keys in a keyset.
1048 extern void ksl_free(keyset **/*ksroot*/);
1050 /* --- @ksl_link@ --- *
1052 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1053 * @keyset *ks@ = pointer to a keyset
1057 * Use: Links a keyset into a list. A keyset can only be on one list
1058 * at a time. Bad things happen otherwise.
1061 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
1063 /* --- @ksl_prune@ --- *
1065 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1069 * Use: Prunes the keyset list by removing keys which mustn't be used
1073 extern void ksl_prune(keyset **/*ksroot*/);
1075 /* --- @ksl_encrypt@ --- *
1077 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1078 * @unsigned ty@ = message type
1079 * @buf *b@ = pointer to input buffer
1080 * @buf *bb@ = pointer to output buffer
1082 * Returns: Zero if successful; @KSERR_REGEN@ if it's time to negotiate a
1083 * new key; @KSERR_NOKEYS@ if there are no suitable keys
1084 * available. Also returns zero if there was insufficient
1085 * buffer space (but the output buffer is broken in this case).
1087 * Use: Encrypts a packet.
1090 extern int ksl_encrypt(keyset **/*ksroot*/, unsigned /*ty*/,
1091 buf */*b*/, buf */*bb*/);
1093 /* --- @ksl_decrypt@ --- *
1095 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1096 * @unsigned ty@ = expected type code
1097 * @buf *b@ = pointer to input buffer
1098 * @buf *bb@ = pointer to output buffer
1100 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
1101 * zero if there was insufficient buffer (but the output buffer
1102 * is broken in this case).
1104 * Use: Decrypts a packet.
1107 extern int ksl_decrypt(keyset **/*ksroot*/, unsigned /*ty*/,
1108 buf */*b*/, buf */*bb*/);
1110 /*----- Challenges --------------------------------------------------------*/
1112 /* --- @c_new@ --- *
1114 * Arguments: @const void *m@ = pointer to associated message, or null
1115 * @size_t msz@ = length of associated message
1116 * @buf *b@ = where to put the challenge
1118 * Returns: Zero if OK, nonzero on error.
1120 * Use: Issues a new challenge.
1123 extern int c_new(const void */*m*/, size_t /*msz*/, buf */*b*/);
1125 /* --- @c_check@ --- *
1127 * Arguments: @const void *m@ = pointer to associated message, or null
1128 * @size_t msz@ = length of associated message
1129 * @buf *b@ = where to find the challenge
1131 * Returns: Zero if OK, nonzero if it didn't work.
1133 * Use: Checks a challenge. On failure, the buffer is broken.
1136 extern int c_check(const void */*m*/, size_t /*msz*/, buf */*b*/);
1138 /*----- Administration interface ------------------------------------------*/
1140 #define A_END ((char *)0)
1142 /* --- @a_vformat@ --- *
1144 * Arguments: @dstr *d@ = where to leave the formatted message
1145 * @const char *fmt@ = pointer to format string
1146 * @va_list *ap@ = arguments in list
1150 * Use: Main message token formatting driver. The arguments are
1151 * interleaved formatting tokens and their parameters, finally
1152 * terminated by an entry @A_END@.
1154 * Tokens recognized:
1156 * * "*..." ... -- pretokenized @dstr_putf@-like string
1158 * * "?ADDR" SOCKADDR -- a socket address, to be converted
1160 * * "?B64" BUFFER SIZE -- binary data to be base64-encoded
1162 * * "?TOKENS" VECTOR -- null-terminated vector of tokens
1164 * * "?PEER" PEER -- peer's name
1166 * * "?ERRNO" ERRNO -- system error code
1168 * * "[!]..." ... -- @dstr_putf@-like string as single token
1171 extern void a_vformat(dstr */*d*/, const char */*fmt*/, va_list */*ap*/);
1173 /* --- @a_format@ --- *
1175 * Arguments: @dstr *d@ = where to leave the formatted message
1176 * @const char *fmt@ = pointer to format string
1180 * Use: Writes a tokenized message into a string, for later
1184 extern void EXECL_LIKE(0) a_format(dstr */*d*/, const char */*fmt*/, ...);
1186 /* --- @a_info@ --- *
1188 * Arguments: @admin *a@ = connection
1189 * @const char *fmt@ = format string
1190 * @...@ = other arguments
1194 * Use: Report information to an admin client.
1197 extern void EXECL_LIKE(0) a_info(admin */*a*/, const char */*fmt*/, ...);
1199 /* --- @a_warn@ --- *
1201 * Arguments: @const char *fmt@ = pointer to format string
1202 * @...@ = other arguments
1206 * Use: Informs all admin connections of a warning.
1209 extern void EXECL_LIKE(0) a_warn(const char */*fmt*/, ...);
1211 /* --- @a_notify@ --- *
1213 * Arguments: @const char *fmt@ = pointer to format string
1214 * @...@ = other arguments
1218 * Use: Sends a notification to interested admin connections.
1221 extern void EXECL_LIKE(0) a_notify(const char */*fmt*/, ...);
1223 /* --- @a_create@ --- *
1225 * Arguments: @int fd_in, fd_out@ = file descriptors to use
1226 * @unsigned f@ = initial flags to set
1230 * Use: Creates a new admin connection.
1233 extern void a_create(int /*fd_in*/, int /*fd_out*/, unsigned /*f*/);
1235 /* --- @a_quit@ --- *
1241 * Use: Shuts things down nicely.
1244 extern void a_quit(void);
1246 /* --- @a_preselect@ --- *
1252 * Use: Informs the admin module that we're about to select again,
1253 * and that it should do cleanup things it has delayed until a
1257 extern void a_preselect(void);
1259 /* --- @a_daemon@ --- *
1265 * Use: Informs the admin module that it's a daemon.
1268 extern void a_daemon(void);
1270 /* --- @a_init@ --- *
1272 * Arguments: @const char *sock@ = socket name to create
1273 * @uid_t u@ = user to own the socket
1274 * @gid_t g@ = group to own the socket
1275 * @mode_t m@ = permissions to set on the socket
1279 * Use: Creates the admin listening socket.
1282 extern void a_init(const char */*sock*/,
1283 uid_t /*u*/, gid_t /*g*/, mode_t /*m*/);
1285 /*----- Mapping with addresses as keys ------------------------------------*/
1287 /* --- @am_create@ --- *
1289 * Arguments: @addrmap *m@ = pointer to map
1293 * Use: Create an address map, properly set up.
1296 extern void am_create(addrmap */*m*/);
1298 /* --- @am_destroy@ --- *
1300 * Arguments: @addrmap *m@ = pointer to map
1304 * Use: Destroy an address map, throwing away all the entries.
1307 extern void am_destroy(addrmap */*m*/);
1309 /* --- @am_find@ --- *
1311 * Arguments: @addrmap *m@ = pointer to map
1312 * @const addr *a@ = address to look up
1313 * @size_t sz@ = size of block to allocate
1314 * @unsigned *f@ = where to store flags
1316 * Returns: Pointer to found item, or null.
1318 * Use: Finds a record with the given IP address, set @*f@ nonzero
1319 * and returns it. If @sz@ is zero, and no match was found,
1320 * return null; otherwise allocate a new block of @sz@ bytes,
1321 * clear @*f@ to zero and return the block pointer.
1324 extern void *am_find(addrmap */*m*/, const addr */*a*/,
1325 size_t /*sz*/, unsigned */*f*/);
1327 /* --- @am_remove@ --- *
1329 * Arguments: @addrmap *m@ = pointer to map
1330 * @void *i@ = pointer to the item
1334 * Use: Removes an item from the map.
1337 extern void am_remove(addrmap */*m*/, void */*i*/);
1339 /*----- Privilege separation ----------------------------------------------*/
1341 /* --- @ps_trace@ --- *
1343 * Arguments: @unsigned mask@ = trace mask to check
1344 * @const char *fmt@ = message format
1345 * @...@ = values for placeholders
1349 * Use: Writes a trace message.
1352 T( extern void PRINTF_LIKE(2, 3)
1353 ps_trace(unsigned /*mask*/, const char */*fmt*/, ...); )
1355 /* --- @ps_warn@ --- *
1357 * Arguments: @const char *fmt@ = message format
1358 * @...@ = values for placeholders
1362 * Use: Writes a warning message.
1365 extern void PRINTF_LIKE(1, 2) ps_warn(const char */*fmt*/, ...);
1367 /* --- @ps_tunfd@ --- *
1369 * Arguments: @const tunnel_ops *tops@ = pointer to tunnel operations
1370 * @char **ifn@ = where to put the interface name
1372 * Returns: The file descriptor, or @-1@ on error.
1374 * Use: Fetches a file descriptor for a tunnel driver.
1377 extern int ps_tunfd(const tunnel_ops */*tops*/, char **/*ifn*/);
1379 /* --- @ps_split@ --- *
1381 * Arguments: @int detachp@ = whether to detach the child from its terminal
1385 * Use: Separates off the privileged tunnel-opening service from the
1386 * rest of the server.
1389 extern void ps_split(int /*detachp*/);
1391 /* --- @ps_quit@ --- *
1397 * Use: Detaches from the helper process.
1400 extern void ps_quit(void);
1402 /*----- Peer management ---------------------------------------------------*/
1404 /* --- @p_updateaddr@ --- *
1406 * Arguments: @peer *p@ = pointer to peer block
1407 * @const addr *a@ = address to associate with this peer
1409 * Returns: Zero if the address was changed; @+1@ if it was already
1412 * Use: Updates our idea of @p@'s address.
1415 extern int p_updateaddr(peer */*p*/, const addr */*a*/);
1417 /* --- @p_txstart@ --- *
1419 * Arguments: @peer *p@ = pointer to peer block
1420 * @unsigned msg@ = message type code
1422 * Returns: A pointer to a buffer to write to.
1424 * Use: Starts sending to a peer. Only one send can happen at a
1428 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
1430 /* --- @p_txend@ --- *
1432 * Arguments: @peer *p@ = pointer to peer block
1436 * Use: Sends a packet to the peer.
1439 extern void p_txend(peer */*p*/);
1441 /* --- @p_pingsend@ --- *
1443 * Arguments: @peer *p@ = destination peer
1444 * @ping *pg@ = structure to fill in
1445 * @unsigned type@ = message type
1446 * @unsigned long timeout@ = how long to wait before giving up
1447 * @void (*func)(int, void *)@ = callback function
1448 * @void *arg@ = argument for callback
1450 * Returns: Zero if successful, nonzero if it failed.
1452 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
1453 * if we get an answer within the timeout, or zero if no answer.
1456 extern int p_pingsend(peer */*p*/, ping */*pg*/, unsigned /*type*/,
1457 unsigned long /*timeout*/,
1458 void (*/*func*/)(int, void *), void */*arg*/);
1460 /* --- @p_pingdone@ --- *
1462 * Arguments: @ping *p@ = ping structure
1463 * @int rc@ = return code to pass on
1467 * Use: Disposes of a ping structure, maybe sending a notification.
1470 extern void p_pingdone(ping */*p*/, int /*rc*/);
1472 /* --- @p_greet@ --- *
1474 * Arguments: @peer *p@ = peer to send to
1475 * @const void *c@ = pointer to challenge
1476 * @size_t sz@ = size of challenge
1480 * Use: Sends a greeting packet.
1483 extern void p_greet(peer */*p*/, const void */*c*/, size_t /*sz*/);
1485 /* --- @p_tun@ --- *
1487 * Arguments: @peer *p@ = pointer to peer block
1488 * @buf *b@ = buffer containing incoming packet
1492 * Use: Handles a packet which needs to be sent to a peer.
1495 extern void p_tun(peer */*p*/, buf */*b*/);
1497 /* --- @p_keyreload@ --- *
1503 * Use: Forces a check of the daemon's keyring files.
1506 extern void p_keyreload(void);
1508 /* --- @p_interval@ --- *
1514 * Use: Called periodically to do tidying.
1517 extern void p_interval(void);
1519 /* --- @p_stats@ --- *
1521 * Arguments: @peer *p@ = pointer to a peer block
1523 * Returns: A pointer to the peer's statistics.
1526 extern stats *p_stats(peer */*p*/);
1528 /* --- @p_ifname@ --- *
1530 * Arguments: @peer *p@ = pointer to a peer block
1532 * Returns: A pointer to the peer's interface name.
1535 extern const char *p_ifname(peer */*p*/);
1537 /* --- @p_setifname@ --- *
1539 * Arguments: @peer *p@ = pointer to a peer block
1540 * @const char *name@ = pointer to the new name
1544 * Use: Changes the name held for a peer's interface.
1547 extern void p_setifname(peer */*p*/, const char */*name*/);
1549 /* --- @p_addr@ --- *
1551 * Arguments: @peer *p@ = pointer to a peer block
1553 * Returns: A pointer to the peer's address.
1556 extern const addr *p_addr(peer */*p*/);
1558 /* --- @p_init@ --- *
1560 * Arguments: @struct in_addr addr@ = address to bind to
1561 * @unsigned port@ = port number to listen to
1565 * Use: Initializes the peer system; creates the socket.
1568 extern void p_init(struct in_addr /*addr*/, unsigned /*port*/);
1570 /* --- @p_port@ --- *
1574 * Returns: Port number used for socket.
1577 unsigned p_port(void);
1579 /* --- @p_create@ --- *
1581 * Arguments: @peerspec *spec@ = information about this peer
1583 * Returns: Pointer to the peer block, or null if it failed.
1585 * Use: Creates a new named peer block. No peer is actually attached
1589 extern peer *p_create(peerspec */*spec*/);
1591 /* --- @p_name@ --- *
1593 * Arguments: @peer *p@ = pointer to a peer block
1595 * Returns: A pointer to the peer's name.
1597 * Use: Equivalent to @p_spec(p)->name@.
1600 extern const char *p_name(peer */*p*/);
1602 /* --- @p_tag@ --- *
1604 * Arguments: @peer *p@ = pointer to a peer block
1606 * Returns: A pointer to the peer's public key tag.
1609 extern const char *p_tag(peer */*p*/);
1611 /* --- @p_privtag@ --- *
1613 * Arguments: @peer *p@ = pointer to a peer block
1615 * Returns: A pointer to the peer's private key tag.
1618 extern const char *p_privtag(peer */*p*/);
1620 /* --- @p_spec@ --- *
1622 * Arguments: @peer *p@ = pointer to a peer block
1624 * Returns: Pointer to the peer's specification
1627 extern const peerspec *p_spec(peer */*p*/);
1629 /* --- @p_findbyaddr@ --- *
1631 * Arguments: @const addr *a@ = address to look up
1633 * Returns: Pointer to the peer block, or null if not found.
1635 * Use: Finds a peer by address.
1638 extern peer *p_findbyaddr(const addr */*a*/);
1640 /* --- @p_find@ --- *
1642 * Arguments: @const char *name@ = name to look up
1644 * Returns: Pointer to the peer block, or null if not found.
1646 * Use: Finds a peer by name.
1649 extern peer *p_find(const char */*name*/);
1651 /* --- @p_destroy@ --- *
1653 * Arguments: @peer *p@ = pointer to a peer
1657 * Use: Destroys a peer.
1660 extern void p_destroy(peer */*p*/);
1662 /* --- @FOREACH_PEER@ --- *
1664 * Arguments: @p@ = name to bind to each peer
1665 * @stuff@ = thing to do for each item
1667 * Use: Does something for each current peer.
1670 #define FOREACH_PEER(p, stuff) do { \
1673 for (p_mkiter(&i_); (p = p_next(&i_)) != 0; ) stuff \
1676 /* --- @p_mkiter@ --- *
1678 * Arguments: @peer_iter *i@ = pointer to an iterator
1682 * Use: Initializes the iterator.
1685 extern void p_mkiter(peer_iter */*i*/);
1687 /* --- @p_next@ --- *
1689 * Arguments: @peer_iter *i@ = pointer to an iterator
1691 * Returns: Next peer, or null if at the end.
1693 * Use: Returns the next peer.
1696 extern peer *p_next(peer_iter */*i*/);
1698 /*----- Tunnel drivers ----------------------------------------------------*/
1701 extern const tunnel_ops tun_linux;
1705 extern const tunnel_ops tun_unet;
1709 extern const tunnel_ops tun_bsd;
1712 extern const tunnel_ops tun_slip;
1714 /*----- Other handy utilities ---------------------------------------------*/
1716 /* --- @timestr@ --- *
1718 * Arguments: @time_t t@ = a time to convert
1720 * Returns: A pointer to a textual representation of the time.
1722 * Use: Converts a time to a textual representation. Corrupts
1726 extern const char *timestr(time_t /*t*/);
1728 /* --- @mystrieq@ --- *
1730 * Arguments: @const char *x, *y@ = two strings
1732 * Returns: True if @x@ and @y are equal, up to case.
1735 extern int mystrieq(const char */*x*/, const char */*y*/);
1737 /* --- @addrsz@ --- *
1739 * Arguments: @const addr *a@ = a network address
1741 * Returns: The size of the address, for passing into the sockets API.
1744 extern socklen_t addrsz(const addr */*a*/);
1746 /* --- @seq_reset@ --- *
1748 * Arguments: @seqwin *s@ = sequence-checking window
1752 * Use: Resets a sequence number window.
1755 extern void seq_reset(seqwin */*s*/);
1757 /* --- @seq_check@ --- *
1759 * Arguments: @seqwin *s@ = sequence-checking window
1760 * @uint32 q@ = sequence number to check
1761 * @const char *service@ = service to report message from
1763 * Returns: A @SEQ_@ code.
1765 * Use: Checks a sequence number against the window, updating things
1769 extern int seq_check(seqwin */*s*/, uint32 /*q*/, const char */*service*/);
1771 typedef struct ratelim {
1772 unsigned n, max, persec;
1773 struct timeval when;
1776 /* --- @ratelim_init@ --- *
1778 * Arguments: @ratelim *r@ = rate-limiting state to fill in
1779 * @unsigned persec@ = credit to accumulate per second
1780 * @unsigned max@ = maximum credit to retain
1784 * Use: Initialize a rate-limiting state.
1787 extern void ratelim_init(ratelim */*r*/,
1788 unsigned /*persec*/, unsigned /*max*/);
1790 /* --- @ratelim_withdraw@ --- *
1792 * Arguments: @ratelim *r@ = rate-limiting state
1793 * @unsigned n@ = credit to withdraw
1795 * Returns: Zero if successful; @-1@ if there is unsufficient credit
1797 * Use: Updates the state with any accumulated credit. Then, if
1798 * there there are more than @n@ credits available, withdraw @n@
1799 * and return successfully; otherwise, report failure.
1802 extern int ratelim_withdraw(ratelim */*r*/, unsigned /*n*/);
1804 /*----- That's all, folks -------------------------------------------------*/