3 * $Id: socket.c,v 1.10 2003/11/25 14:08:23 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 1.10 2003/11/25 14:08:23 mdw
33 * Debianization. Socket target options. Internet binding.
35 * Revision 1.9 2002/02/23 00:08:00 mdw
36 * Fix stupid bugs from the listen(2) change.
38 * Revision 1.8 2002/02/22 23:44:44 mdw
39 * Call @xfree@ rather than @free@. Add option to change the listen(2)
42 * Revision 1.7 2001/06/22 19:37:00 mdw
43 * New @conn_init@ interface.
45 * Revision 1.6 2001/02/03 20:30:03 mdw
46 * Support re-reading config files on SIGHUP.
48 * Revision 1.5 2000/03/23 23:20:42 mdw
49 * Remove listener even if connection option isn't SOCKOPT_LIMITED.
51 * Revision 1.4 1999/12/22 15:44:25 mdw
54 * Revision 1.3 1999/10/22 22:48:36 mdw
55 * New connection options: unlimited concurrent connections, and one-shot
58 * Revision 1.2 1999/07/27 18:30:53 mdw
59 * Various minor portability fixes.
61 * Revision 1.1 1999/07/26 23:33:32 mdw
62 * New sources and targets.
66 /*----- Header files ------------------------------------------------------*/
77 #include <sys/types.h>
80 #include <sys/socket.h>
81 #include <netinet/in.h>
82 #include <arpa/inet.h>
85 #include <mLib/alloc.h>
86 #include <mLib/conn.h>
87 #include <mLib/dstr.h>
88 #include <mLib/fdflags.h>
103 /*----- Data structures ---------------------------------------------------*/
105 /* --- Socket source options --- */
107 typedef struct ssource_opts {
113 static ssource_opts ssgo = { 256, 0, 5 };
115 #define SOCKOPT_LIMIT 0u
116 #define SOCKOPT_NOLIMIT 1u
117 #define SOCKOPT_ONESHOT 2u
119 /* --- Socket source --- */
121 typedef struct ssource {
130 /* --- Socket target --- */
132 typedef struct starget {
138 /* --- Socket target endpoint --- */
140 typedef struct stept {
146 /* --- Socket source endpoint --- */
148 typedef struct ssept {
153 /*----- Protocol table ----------------------------------------------------*/
155 static addr_ops *addrs[] = { &inet_ops, &un_ops, 0 };
157 /*----- Other persistent variables ----------------------------------------*/
159 static addr_opts gsao = { 0 }, gtao = { 0 };
161 /*----- Parsing address types ---------------------------------------------*/
163 /* --- @getaddrtype@ --- *
165 * Arguments: @scanner *sc@ = pointer to scanner (for error reporting)
166 * @const char *p@ = pointer to protocol name
167 * @int abbrev@ = nonzero to allow abbreviations
169 * Returns: Pointer to address operations table or null.
171 * Use: Looks up a protocol name. Handy when parsing addresses and
172 * other bits of configuration. Returns null if no matching
176 static addr_ops *getaddrtype(scanner *sc, const char *p, int abbrev)
179 addr_ops *chosen = 0;
180 size_t sz = strlen(p);
182 for (ops = addrs; *ops; ops++) {
183 if (strncmp((*ops)->name, p, sz) == 0) {
184 if ((*ops)->name[sz] == 0)
186 else if (chosen && abbrev)
187 error(sc, "ambiguous socket address type `%s'", p);
196 /* --- @getaddr@ --- *
198 * Arguments: @scanner *sc@ = pointer to scanner to read from
199 * @unsigned type@ = address type (@ADDR_SRC@ or @ADDR_DEST@)
201 * Returns: Pointer to an address successfully read.
203 * Use: Reads an optionally qualified address.
206 static addr *getaddr(scanner *sc, unsigned type)
215 if (sc->t == CTOK_WORD)
216 ops = getaddrtype(sc, sc->d.buf, abbrev);
220 error(sc, "unknown socket address type `%s'", sc->d.buf);
226 return (ops->read(sc, type));
229 /*----- Socket endpoints --------------------------------------------------*/
231 /* --- @wclose@ --- */
233 static void sept_wclose(endpt *e)
235 shutdown(e->out->fd, 1);
238 /* --- @close@ (source) --- */
240 static void ss_listen(ssource */*ss*/);
242 static void ssept_close(endpt *e)
244 ssept *ee = (ssept *)e;
246 if (ee->s->o.opt == SOCKOPT_LIMIT) {
248 if (ee->s->o.conn == 1)
252 REFFD_DEC(ee->e.out);
257 /* --- @close@ (target) --- */
259 static void stept_close(endpt *e)
261 stept *ee = (stept *)e;
263 if (ee->e.f & EPF_PENDING)
267 REFFD_DEC(ee->e.out);
275 /* --- @starget_connected@ --- *
277 * Arguments: @int fd@ = file descriptor now ready for use
278 * @void *p@ = pointer to an endpoint structure
282 * Use: Handles successful connection of the target endpoint.
285 void starget_connected(int fd, void *p)
290 fw_log(-1, "[%s] connection failed: %s", e->desc, strerror(errno));
293 reffd *r = reffd_init(fd);
296 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
297 setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
298 e->e.in = e->e.out = r;
299 e->e.f &= ~EPF_PENDING;
301 endpt_join(&e->e, e->e.other);
305 /* --- Socket endpoint definition --- */
307 static endpt_ops ssept_ops = {
308 0, 0, sept_wclose, ssept_close
311 static endpt_ops stept_ops = {
312 0, 0, sept_wclose, stept_close
315 /*----- Source definition -------------------------------------------------*/
317 /* --- @option@ --- */
319 static int ssource_option(source *s, scanner *sc)
321 ssource *ss = (ssource *)s;
322 ssource_opts *sso = ss ? &ss->o : &ssgo;
324 CONF_BEGIN(sc, "socket", "socket source")
326 /* --- Make sure the next token is a word --- */
328 if (sc->t != CTOK_WORD)
329 error(sc, "parse error, option keyword expected");
331 /* --- Handle options at this level --- */
333 if (strcmp(sc->d.buf, "conn") == 0) {
337 if (sc->t != CTOK_WORD)
338 error(sc, "parse error, expected `unlimited', `one-shot' or number");
339 if (isdigit((unsigned char)sc->d.buf[0])) {
340 sso->conn = atoi(sc->d.buf);
342 error(sc, "argument of `conn' must be positive");
343 sso->opt = SOCKOPT_LIMIT;
347 sso->opt = 1 + (1 & conf_enum(sc,
348 "unlimited,one-shot,infinite",
349 ENUM_ABBREV, "`conn' option"));
354 if (strcmp(sc->d.buf, "listen") == 0) {
358 if (sc->t != CTOK_WORD || !isdigit((unsigned char)sc->d.buf[0]))
359 error(sc, "parse error, expected number");
360 sso->listen = atoi(sc->d.buf);
361 if (sso->listen == 0)
362 error(sc, "argument of `listen' must be positive");
367 if (strcmp(sc->d.buf, "logging") == 0 ||
368 strcmp(sc->d.buf, "log") == 0) {
369 addr_opts *ao = ss ? ss->ao : &gsao;
373 if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status"))
374 ao->f &= ~ADDRF_NOLOG;
376 ao->f |= ADDRF_NOLOG;
380 /* --- Pass the option around the various address types --- */
383 if (ss->a->ops->option && ss->a->ops->option(sc, ss->ao, ADDR_SRC))
387 for (a = addrs; *a; a++) {
388 if ((*a)->option && (*a)->option(sc, 0, ADDR_GLOBAL))
393 /* --- Nobody understood the option --- */
400 static source *ssource_read(scanner *sc)
404 (void)(conf_prefix(sc, "socket") || conf_prefix(sc, "sk"));
405 ss = CREATE(ssource);
406 ss->s.ops = &ssource_ops;
409 ss->a = getaddr(sc, ADDR_SRC);
410 if (ss->a->ops->initsrcopts)
411 ss->ao = ss->a->ops->initsrcopts();
413 ss->ao = CREATE(addr_opts);
419 /* --- @ss_accept@ --- *
421 * Arguments: @int fd@ = file descriptor to accept from
422 * @unsigned mode@ = what's ready with the descriptor
423 * @void *p@ = pointer to the source definition
427 * Use: Accepts an incoming connection and attaches it to a target
431 static void ssource_destroy(source */*s*/);
433 static void ss_accept(int fd, unsigned mode, void *p)
440 /* --- Make the file descriptor --- */
444 if ((r = ss->a->ops->accept(fd, ss->ao, ss->s.desc)) == 0)
446 setsockopt(r->fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
447 fdflags(r->fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
450 /* --- Make an endpoint --- */
453 e->e.ops = &ssept_ops;
457 e->e.in = e->e.out = r;
461 /* --- Obtain the target endpoint and let rip --- */
463 if ((ee = ss->t->ops->create(ss->t, ss->s.desc)) == 0) {
471 /* --- Remove the listening socket if necessary --- */
477 if (!(ss->ao->f & ADDRF_NOLOG))
478 fw_log(-1, "[%s] maximum connections reached", ss->s.desc);
481 if (ss->a->ops->unbind)
482 ss->a->ops->unbind(ss->a);
485 case SOCKOPT_NOLIMIT:
487 case SOCKOPT_ONESHOT:
490 if (ss->a->ops->unbind)
491 ss->a->ops->unbind(ss->a);
492 ssource_destroy(&ss->s);
496 /* --- Let everything else happen --- */
498 endpt_join(&e->e, ee);
501 /* --- @ss_listen@ --- *
503 * Arguments: @ssource *ss@ = source to listen on
507 * Use: Sets the socket to listen again, if it stopped for some
508 * reason. This is a copy of the code in the @read@ function,
509 * because it has different (wildly different) error handling
513 static void ss_listen(ssource *ss)
518 if (!(ss->ao->f & ADDRF_NOLOG))
519 fw_log(-1, "[%s] reattaching listener", ss->s.desc);
521 /* --- Make the socket --- */
523 if ((fd = ss->a->ops->bind(ss->a, ss->ao)) < 0) {
524 fw_log(-1, "[%s] couldn't create socket: %s",
525 ss->s.desc, strerror(errno));
529 /* --- Set it to listen for connections --- */
531 setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
532 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
533 if (listen(fd, ss->o.listen)) {
534 fw_log(-1, "[%s] couldn't listen on socket: %s",
535 ss->s.desc, strerror(errno));
539 /* --- Set the listener up again --- */
545 /* --- Tidy up if it failed --- *
547 * I'll just remove the entire source.
554 ssource_destroy(&ss->s);
557 /* --- @attach@ --- */
559 static void ssource_attach(source *s, scanner *sc, target *t)
561 ssource *ss = (ssource *)s;
567 /* --- Initialize the description string --- */
571 dstr_puts(&d, "socket.");
572 ss->a->ops->print(ss->a, ADDR_SRC, &d);
573 dstr_puts(&d, " -> ");
574 dstr_puts(&d, ss->t->desc);
575 ss->s.desc = xstrdup(d.buf);
579 /* --- Initialize the socket for listening --- */
581 if ((fd = ss->a->ops->bind(ss->a, ss->ao)) < 0)
582 error(sc, "couldn't bind socket `%s': %s", ss->s.desc, strerror(errno));
584 /* --- Set it to listen for connections --- */
586 setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
587 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
588 if (listen(fd, ss->o.listen)) {
589 error(sc, "couldn't listen on socket `%s': %s",
590 ss->s.desc, strerror(errno));
593 /* --- We're ready to go now --- */
595 sel_initfile(sel, &ss->r, fd, SEL_READ, ss_accept, ss);
601 /* --- @destroy@ --- */
603 static void ssource_destroy(source *s)
605 ssource *ss = (ssource *)s;
607 if (ss->o.conn || ss->o.opt != SOCKOPT_LIMIT) {
610 if (ss->a->ops->unbind)
611 ss->a->ops->unbind(ss->a);
613 if (ss->a->ops->freesrcopts)
614 ss->a->ops->freesrcopts(ss->ao);
618 ss->a->ops->destroy(ss->a);
619 ss->t->ops->destroy(ss->t);
620 source_remove(&ss->s);
625 /* --- Source definition block --- */
627 source_ops ssource_ops = {
629 ssource_option, ssource_read, ssource_attach, ssource_destroy
632 /*----- Target definition -------------------------------------------------*/
634 /* --- @options@ --- */
636 static int starget_option(target *t, scanner *sc)
638 starget *st = (starget *)t;
640 CONF_BEGIN(sc, "starget", "socket target")
642 /* --- Pass the option around the various address types --- */
645 if (st->a->ops->option && st->a->ops->option(sc, st->ao, ADDR_DEST))
648 /* We'd have done it already if it was global */
657 static target *starget_read(scanner *sc)
662 (void)(conf_prefix(sc, "socket") || conf_prefix(sc, "sk"));
663 st = CREATE(starget);
664 st->t.ops = &starget_ops;
665 st->a = getaddr(sc, ADDR_DEST);
666 if (st->a->ops->inittargopts)
667 st->ao = st->a->ops->inittargopts();
669 st->ao = CREATE(addr_opts);
671 dstr_puts(&d, "socket.");
672 st->a->ops->print(st->a, ADDR_DEST, &d);
673 st->t.desc = xstrdup(d.buf);
678 /* --- @create@ --- *
680 * Arguments: @target *t@ = pointer to target
681 * @const char *desc@ = description of connection
683 * Returns: Pointer to a created endpoint.
685 * Use: Generates a target endpoint for communication.
688 static endpt *starget_create(target *t, const char *desc)
690 starget *st = (starget *)t;
691 stept *e = CREATE(stept);
693 e->e.ops = &stept_ops;
695 e->e.f = EPF_FILE | EPF_PENDING;
697 e->desc = xstrdup(desc);
698 if (st->a->ops->connect(st->a, st->ao, &e->c, &e->e)) {
699 fw_log(-1, "[%s] couldn't connect: %s", e->desc, strerror(errno));
707 /* --- @destroy@ --- */
709 static void starget_destroy(target *t)
711 starget *st = (starget *)t;
712 if (st->a->ops->freetargopts)
713 st->a->ops->freetargopts(st->ao);
716 st->a->ops->destroy(st->a);
721 /* --- Socket target definition block --- */
723 target_ops starget_ops = {
725 starget_option, starget_read, starget_create, starget_destroy
728 /*----- That's all, folks -------------------------------------------------*/