3 * $Id: socket.c,v 1.9 2002/02/23 00:08:00 mdw Exp $
5 * Socket source and target definitions
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the `fw' port forwarder.
14 * `fw' 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 * `fw' 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 `fw'; 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 2002/02/23 00:08:00 mdw
33 * Fix stupid bugs from the listen(2) change.
35 * Revision 1.8 2002/02/22 23:44:44 mdw
36 * Call @xfree@ rather than @free@. Add option to change the listen(2)
39 * Revision 1.7 2001/06/22 19:37:00 mdw
40 * New @conn_init@ interface.
42 * Revision 1.6 2001/02/03 20:30:03 mdw
43 * Support re-reading config files on SIGHUP.
45 * Revision 1.5 2000/03/23 23:20:42 mdw
46 * Remove listener even if connection option isn't SOCKOPT_LIMITED.
48 * Revision 1.4 1999/12/22 15:44:25 mdw
51 * Revision 1.3 1999/10/22 22:48:36 mdw
52 * New connection options: unlimited concurrent connections, and one-shot
55 * Revision 1.2 1999/07/27 18:30:53 mdw
56 * Various minor portability fixes.
58 * Revision 1.1 1999/07/26 23:33:32 mdw
59 * New sources and targets.
63 /*----- Header files ------------------------------------------------------*/
74 #include <sys/types.h>
77 #include <sys/socket.h>
78 #include <netinet/in.h>
79 #include <arpa/inet.h>
82 #include <mLib/alloc.h>
83 #include <mLib/conn.h>
84 #include <mLib/dstr.h>
85 #include <mLib/fdflags.h>
100 /*----- Data structures ---------------------------------------------------*/
102 /* --- Socket source options --- */
104 typedef struct ssource_opts {
110 static ssource_opts ssgo = { 256, 0, 5 };
112 #define SOCKOPT_LIMIT 0u
113 #define SOCKOPT_NOLIMIT 1u
114 #define SOCKOPT_ONESHOT 2u
116 /* --- Socket source --- */
118 typedef struct ssource {
127 /* --- Socket target --- */
129 typedef struct starget {
135 /* --- Socket target endpoint --- */
137 typedef struct stept {
143 /* --- Socket source endpoint --- */
145 typedef struct ssept {
150 /*----- Protocol table ----------------------------------------------------*/
152 static addr_ops *addrs[] = { &inet_ops, &un_ops, 0 };
154 /*----- Other persistent variables ----------------------------------------*/
156 static addr_opts gao = { 0 };
158 /*----- Parsing address types ---------------------------------------------*/
160 /* --- @getaddrtype@ --- *
162 * Arguments: @scanner *sc@ = pointer to scanner (for error reporting)
163 * @const char *p@ = pointer to protocol name
164 * @int abbrev@ = nonzero to allow abbreviations
166 * Returns: Pointer to address operations table or null.
168 * Use: Looks up a protocol name. Handy when parsing addresses and
169 * other bits of configuration. Returns null if no matching
173 static addr_ops *getaddrtype(scanner *sc, const char *p, int abbrev)
176 addr_ops *chosen = 0;
177 size_t sz = strlen(p);
179 for (ops = addrs; *ops; ops++) {
180 if (strncmp((*ops)->name, p, sz) == 0) {
181 if ((*ops)->name[sz] == 0)
183 else if (chosen && abbrev)
184 error(sc, "ambiguous socket address type `%s'", p);
193 /* --- @getaddr@ --- *
195 * Arguments: @scanner *sc@ = pointer to scanner to read from
196 * @unsigned type@ = address type (@ADDR_SRC@ or @ADDR_DEST@)
198 * Returns: Pointer to an address successfully read.
200 * Use: Reads an optionally qualified address.
203 static addr *getaddr(scanner *sc, unsigned type)
212 if (sc->t == CTOK_WORD)
213 ops = getaddrtype(sc, sc->d.buf, abbrev);
217 error(sc, "unknown socket address type `%s'", sc->d.buf);
223 return (ops->read(sc, type));
226 /*----- Socket endpoints --------------------------------------------------*/
228 /* --- @wclose@ --- */
230 static void sept_wclose(endpt *e)
232 shutdown(e->out->fd, 1);
235 /* --- @close@ (source) --- */
237 static void ss_listen(ssource */*ss*/);
239 static void ssept_close(endpt *e)
241 ssept *ee = (ssept *)e;
243 if (ee->s->o.opt == SOCKOPT_LIMIT) {
245 if (ee->s->o.conn == 1)
249 REFFD_DEC(ee->e.out);
254 /* --- @close@ (target) --- */
256 static void stept_close(endpt *e)
258 stept *ee = (stept *)e;
260 if (ee->e.f & EPF_PENDING)
264 REFFD_DEC(ee->e.out);
272 /* --- @stept_go@ --- *
274 * Arguments: @int fd@ = file descriptor now ready for use
275 * @void *p@ = pointer to an endpoint structure
279 * Use: Handles successful connection of the target endpoint.
282 static void stept_go(int fd, void *p)
287 fw_log(-1, "[%s] connection failed: %s", e->desc, strerror(errno));
290 reffd *r = reffd_init(fd);
292 e->e.in = e->e.out = r;
293 e->e.f &= ~EPF_PENDING;
295 endpt_join(&e->e, e->e.other);
299 /* --- Socket endpoint definition --- */
301 static endpt_ops ssept_ops = {
302 0, 0, sept_wclose, ssept_close
305 static endpt_ops stept_ops = {
306 0, 0, sept_wclose, stept_close
309 /*----- Source definition -------------------------------------------------*/
311 /* --- @option@ --- */
313 static int ssource_option(source *s, scanner *sc)
315 ssource *ss = (ssource *)s;
316 ssource_opts *sso = ss ? &ss->o : &ssgo;
318 CONF_BEGIN(sc, "socket", "socket")
320 /* --- Make sure the next token is a word --- */
322 if (sc->t != CTOK_WORD)
323 error(sc, "parse error, option keyword expected");
325 /* --- Handle options at this level --- */
327 if (strcmp(sc->d.buf, "conn") == 0) {
331 if (sc->t != CTOK_WORD)
332 error(sc, "parse error, expected `unlimited', `one-shot' or number");
333 if (isdigit((unsigned char)sc->d.buf[0])) {
334 sso->conn = atoi(sc->d.buf);
336 error(sc, "argument of `conn' must be positive");
337 sso->opt = SOCKOPT_LIMIT;
341 sso->opt = 1 + (1 & conf_enum(sc,
342 "unlimited,one-shot,infinite",
343 ENUM_ABBREV, "`conn' option"));
348 if (strcmp(sc->d.buf, "listen") == 0) {
352 if (sc->t != CTOK_WORD || !isdigit((unsigned char)sc->d.buf[0]))
353 error(sc, "parse error, expected number");
354 sso->listen = atoi(sc->d.buf);
355 if (sso->listen == 0)
356 error(sc, "argument of `listen' must be positive");
361 if (strcmp(sc->d.buf, "logging") == 0 ||
362 strcmp(sc->d.buf, "log") == 0) {
363 addr_opts *ao = ss ? ss->ao : &gao;
367 if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status"))
368 ao->f &= ~ADDRF_NOLOG;
370 ao->f |= ADDRF_NOLOG;
374 /* --- Pass the option around the various address types --- */
377 if (ss->a->ops->option && ss->a->ops->option(sc, ss ? ss->ao : 0))
381 for (a = addrs; *a; a++) {
382 if ((*a)->option && (*a)->option(sc, 0))
387 /* --- Nobody understood the option --- */
394 static source *ssource_read(scanner *sc)
398 (void)(conf_prefix(sc, "socket") || conf_prefix(sc, "sk"));
399 ss = CREATE(ssource);
400 ss->s.ops = &ssource_ops;
403 ss->a = getaddr(sc, ADDR_SRC);
404 if (ss->a->ops->initopts)
405 ss->ao = ss->a->ops->initopts();
407 ss->ao = CREATE(addr_opts);
413 /* --- @ss_accept@ --- *
415 * Arguments: @int fd@ = file descriptor to accept from
416 * @unsigned mode@ = what's ready with the descriptor
417 * @void *p@ = pointer to the source definition
421 * Use: Accepts an incoming connection and attaches it to a target
425 static void ssource_destroy(source */*s*/);
427 static void ss_accept(int fd, unsigned mode, void *p)
434 /* --- Make the file descriptor --- */
438 if ((r = ss->a->ops->accept(fd, ss->ao, ss->s.desc)) == 0)
440 setsockopt(r->fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
441 fdflags(r->fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
444 /* --- Make an endpoint --- */
447 e->e.ops = &ssept_ops;
451 e->e.in = e->e.out = r;
455 /* --- Obtain the target endpoint and let rip --- */
457 if ((ee = ss->t->ops->create(ss->t, ss->s.desc)) == 0) {
465 /* --- Remove the listening socket if necessary --- */
471 if (!(ss->ao->f & ADDRF_NOLOG))
472 fw_log(-1, "[%s] maximum connections reached", ss->s.desc);
475 if (ss->a->ops->unbind)
476 ss->a->ops->unbind(ss->a);
479 case SOCKOPT_NOLIMIT:
481 case SOCKOPT_ONESHOT:
484 if (ss->a->ops->unbind)
485 ss->a->ops->unbind(ss->a);
486 ssource_destroy(&ss->s);
490 /* --- Let everything else happen --- */
492 endpt_join(&e->e, ee);
495 /* --- @ss_listen@ --- *
497 * Arguments: @ssource *ss@ = source to listen on
501 * Use: Sets the socket to listen again, if it stopped for some
502 * reason. This is a copy of the code in the @read@ function,
503 * because it has different (wildly different) error handling
507 static void ss_listen(ssource *ss)
509 gen_addr *ga = (gen_addr *)ss->a;
512 if (!(ss->ao->f & ADDRF_NOLOG))
513 fw_log(-1, "[%s] reattaching listener", ss->s.desc);
515 /* --- Make the socket --- */
517 if ((fd = socket(ga->a.ops->pf, SOCK_STREAM, 0)) < 0) {
518 fw_log(-1, "[%s] couldn't create socket: %s",
519 ss->s.desc, strerror(errno));
523 /* --- Set it to allow address reuse --- */
527 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
528 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
531 /* --- Bind it to the right port --- */
533 if (bind(fd, &ga->sa, ga->a.sz)) {
534 fw_log(-1, "[%s] couldn't bind socket: %s", ss->s.desc, strerror(errno));
537 if (ga->a.ops->bound)
538 ga->a.ops->bound(&ga->a, ss->ao);
540 /* --- Set it to listen for connections --- */
542 if (listen(fd, ss->o.listen)) {
543 fw_log(-1, "[%s] couldn't listen on socket: %s",
544 ss->s.desc, strerror(errno));
548 /* --- Set the listener up again --- */
554 /* --- Tidy up if it failed --- *
556 * I'll just remove the entire source.
563 ssource_destroy(&ss->s);
566 /* --- @attach@ --- */
568 static void ssource_attach(source *s, scanner *sc, target *t)
570 ssource *ss = (ssource *)s;
575 /* --- Initialize the description string --- */
579 dstr_puts(&d, "socket.");
580 ss->a->ops->print(ss->a, ADDR_SRC, &d);
581 dstr_puts(&d, " -> ");
582 dstr_puts(&d, ss->t->desc);
583 ss->s.desc = xstrdup(d.buf);
587 /* --- Initialize the socket for listening --- */
590 gen_addr *ga = (gen_addr *)ss->a;
592 /* --- Make the socket --- */
594 if ((fd = socket(ga->a.ops->pf, SOCK_STREAM, 0)) < 0)
595 error(sc, "couldn't create socket: %s", strerror(errno));
597 /* --- Set it to allow address reuse --- */
601 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
602 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
605 /* --- Bind it to the right port --- */
607 if (bind(fd, &ga->sa, ga->a.sz))
608 error(sc, "couldn't bind to %s: %s", ss->s.desc, strerror(errno));
609 if (ga->a.ops->bound)
610 ga->a.ops->bound(&ga->a, ss->ao);
612 /* --- Set it to listen for connections --- */
614 if (listen(fd, ss->o.listen))
615 error(sc, "couldn't listen on socket: %s", strerror(errno));
618 /* --- We're ready to go now --- */
620 sel_initfile(sel, &ss->r, fd, SEL_READ, ss_accept, ss);
626 /* --- @destroy@ --- */
628 static void ssource_destroy(source *s)
630 ssource *ss = (ssource *)s;
632 if (ss->o.conn || ss->o.opt != SOCKOPT_LIMIT) {
635 if (ss->a->ops->unbind)
636 ss->a->ops->unbind(ss->a);
638 if (ss->a->ops->freeopts)
639 ss->a->ops->freeopts(ss->ao);
643 ss->a->ops->destroy(ss->a);
644 ss->t->ops->destroy(ss->t);
645 source_remove(&ss->s);
650 /* --- Source definition block --- */
652 source_ops ssource_ops = {
654 ssource_option, ssource_read, ssource_attach, ssource_destroy
657 /*----- Target definition -------------------------------------------------*/
661 static target *starget_read(scanner *sc)
666 (void)(conf_prefix(sc, "socket") || conf_prefix(sc, "sk"));
667 st = CREATE(starget);
668 st->t.ops = &starget_ops;
669 st->a = getaddr(sc, ADDR_DEST);
670 dstr_puts(&d, "socket.");
671 st->a->ops->print(st->a, ADDR_DEST, &d);
672 st->t.desc = xstrdup(d.buf);
677 /* --- @create@ --- *
679 * Arguments: @target *t@ = pointer to target
680 * @const char *desc@ = description of connection
682 * Returns: Pointer to a created endpoint.
684 * Use: Generates a target endpoint for communication.
687 static endpt *starget_create(target *t, const char *desc)
689 starget *st = (starget *)t;
690 stept *e = CREATE(stept);
692 gen_addr *ga = (gen_addr *)st->a;
695 if ((fd = socket(st->a->ops->pf, SOCK_STREAM, 0)) < 0)
697 setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
698 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
699 e->e.ops = &stept_ops;
701 e->e.f = EPF_FILE | EPF_PENDING;
703 e->desc = xstrdup(desc);
705 if (conn_init(&e->c, sel, fd, &ga->sa, ga->a.sz, stept_go, e)) {
706 fw_log(-1, "[%s] connection failed: %s", e->desc, strerror(errno));
714 /* --- @destroy@ --- */
716 static void starget_destroy(target *t)
718 starget *st = (starget *)t;
719 st->a->ops->destroy(st->a);
724 /* --- Socket target definition block --- */
726 target_ops starget_ops = {
728 0, starget_read, starget_create, starget_destroy
731 /*----- That's all, folks -------------------------------------------------*/