3 * $Id: socket.c,v 1.11 2003/11/29 20:36:07 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 1.11 2003/11/29 20:36:07 mdw
33 * Privileged outgoing connections.
35 * Revision 1.10 2003/11/25 14:08:23 mdw
36 * Debianization. Socket target options. Internet binding.
38 * Revision 1.9 2002/02/23 00:08:00 mdw
39 * Fix stupid bugs from the listen(2) change.
41 * Revision 1.8 2002/02/22 23:44:44 mdw
42 * Call @xfree@ rather than @free@. Add option to change the listen(2)
45 * Revision 1.7 2001/06/22 19:37:00 mdw
46 * New @conn_init@ interface.
48 * Revision 1.6 2001/02/03 20:30:03 mdw
49 * Support re-reading config files on SIGHUP.
51 * Revision 1.5 2000/03/23 23:20:42 mdw
52 * Remove listener even if connection option isn't SOCKOPT_LIMITED.
54 * Revision 1.4 1999/12/22 15:44:25 mdw
57 * Revision 1.3 1999/10/22 22:48:36 mdw
58 * New connection options: unlimited concurrent connections, and one-shot
61 * Revision 1.2 1999/07/27 18:30:53 mdw
62 * Various minor portability fixes.
64 * Revision 1.1 1999/07/26 23:33:32 mdw
65 * New sources and targets.
69 /*----- Header files ------------------------------------------------------*/
80 #include <sys/types.h>
83 #include <sys/socket.h>
84 #include <netinet/in.h>
85 #include <arpa/inet.h>
88 #include <mLib/alloc.h>
89 #include <mLib/conn.h>
90 #include <mLib/dstr.h>
91 #include <mLib/fdflags.h>
106 /*----- Data structures ---------------------------------------------------*/
108 /* --- Socket source options --- */
110 typedef struct ssource_opts
{
116 static ssource_opts ssgo
= { 256, 0, 5 };
118 #define SOCKOPT_LIMIT 0u
119 #define SOCKOPT_NOLIMIT 1u
120 #define SOCKOPT_ONESHOT 2u
122 /* --- Socket source --- */
124 typedef struct ssource
{
133 /* --- Socket target --- */
135 typedef struct starget
{
141 /* --- Socket target endpoint --- */
143 typedef struct stept
{
149 /* --- Socket source endpoint --- */
151 typedef struct ssept
{
156 /*----- Protocol table ----------------------------------------------------*/
158 static addr_ops
*addrs
[] = { &inet_ops
, &un_ops
, 0 };
160 /*----- Other persistent variables ----------------------------------------*/
162 static addr_opts gsao
= { 0 }, gtao
= { 0 };
164 /*----- Parsing address types ---------------------------------------------*/
166 /* --- @getaddrtype@ --- *
168 * Arguments: @scanner *sc@ = pointer to scanner (for error reporting)
169 * @const char *p@ = pointer to protocol name
170 * @int abbrev@ = nonzero to allow abbreviations
172 * Returns: Pointer to address operations table or null.
174 * Use: Looks up a protocol name. Handy when parsing addresses and
175 * other bits of configuration. Returns null if no matching
179 static addr_ops
*getaddrtype(scanner
*sc
, const char *p
, int abbrev
)
182 addr_ops
*chosen
= 0;
183 size_t sz
= strlen(p
);
185 for (ops
= addrs
; *ops
; ops
++) {
186 if (strncmp((*ops
)->name
, p
, sz
) == 0) {
187 if ((*ops
)->name
[sz
] == 0)
189 else if (chosen
&& abbrev
)
190 error(sc
, "ambiguous socket address type `%s'", p
);
199 /* --- @getaddr@ --- *
201 * Arguments: @scanner *sc@ = pointer to scanner to read from
202 * @unsigned type@ = address type (@ADDR_SRC@ or @ADDR_DEST@)
204 * Returns: Pointer to an address successfully read.
206 * Use: Reads an optionally qualified address.
209 static addr
*getaddr(scanner
*sc
, unsigned type
)
218 if (sc
->t
== CTOK_WORD
)
219 ops
= getaddrtype(sc
, sc
->d
.buf
, abbrev
);
223 error(sc
, "unknown socket address type `%s'", sc
->d
.buf
);
229 return (ops
->read(sc
, type
));
232 /*----- Socket endpoints --------------------------------------------------*/
234 /* --- @wclose@ --- */
236 static void sept_wclose(endpt
*e
)
238 shutdown(e
->out
->fd
, 1);
241 /* --- @close@ (source) --- */
243 static void ss_listen(ssource */
*ss*/
);
245 static void ssept_close(endpt
*e
)
247 ssept
*ee
= (ssept
*)e
;
249 if (ee
->s
->o
.opt
== SOCKOPT_LIMIT
) {
251 if (ee
->s
->o
.conn
== 1)
255 REFFD_DEC(ee
->e
.out
);
260 /* --- @close@ (target) --- */
262 static void stept_close(endpt
*e
)
264 stept
*ee
= (stept
*)e
;
266 if (ee
->e
.f
& EPF_PENDING
)
270 REFFD_DEC(ee
->e
.out
);
278 /* --- @starget_connected@ --- *
280 * Arguments: @int fd@ = file descriptor now ready for use
281 * @void *p@ = pointer to an endpoint structure
285 * Use: Handles successful connection of the target endpoint.
288 void starget_connected(int fd
, void *p
)
293 fw_log(-1, "[%s] connection failed: %s", e
->desc
, strerror(errno
));
296 reffd
*r
= reffd_init(fd
);
299 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
300 setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
301 e
->e
.in
= e
->e
.out
= r
;
302 e
->e
.f
&= ~EPF_PENDING
;
304 endpt_join(&e
->e
, e
->e
.other
);
308 /* --- Socket endpoint definition --- */
310 static endpt_ops ssept_ops
= {
311 0, 0, sept_wclose
, ssept_close
314 static endpt_ops stept_ops
= {
315 0, 0, sept_wclose
, stept_close
318 /*----- Source definition -------------------------------------------------*/
320 /* --- @option@ --- */
322 static int ssource_option(source
*s
, scanner
*sc
)
324 ssource
*ss
= (ssource
*)s
;
325 ssource_opts
*sso
= ss ?
&ss
->o
: &ssgo
;
327 CONF_BEGIN(sc
, "socket", "socket source")
329 /* --- Make sure the next token is a word --- */
331 if (sc
->t
!= CTOK_WORD
)
332 error(sc
, "parse error, option keyword expected");
334 /* --- Handle options at this level --- */
336 if (strcmp(sc
->d
.buf
, "conn") == 0) {
340 if (sc
->t
!= CTOK_WORD
)
341 error(sc
, "parse error, expected `unlimited', `one-shot' or number");
342 if (isdigit((unsigned char)sc
->d
.buf
[0])) {
343 sso
->conn
= atoi(sc
->d
.buf
);
345 error(sc
, "argument of `conn' must be positive");
346 sso
->opt
= SOCKOPT_LIMIT
;
350 sso
->opt
= 1 + (1 & conf_enum(sc
,
351 "unlimited,one-shot,infinite",
352 ENUM_ABBREV
, "`conn' option"));
357 if (strcmp(sc
->d
.buf
, "listen") == 0) {
361 if (sc
->t
!= CTOK_WORD
|| !isdigit((unsigned char)sc
->d
.buf
[0]))
362 error(sc
, "parse error, expected number");
363 sso
->listen
= atoi(sc
->d
.buf
);
364 if (sso
->listen
== 0)
365 error(sc
, "argument of `listen' must be positive");
370 if (strcmp(sc
->d
.buf
, "logging") == 0 ||
371 strcmp(sc
->d
.buf
, "log") == 0) {
372 addr_opts
*ao
= ss ? ss
->ao
: &gsao
;
376 if (conf_enum(sc
, "no,yes", ENUM_ABBREV
, "logging status"))
377 ao
->f
&= ~ADDRF_NOLOG
;
379 ao
->f
|= ADDRF_NOLOG
;
383 /* --- Pass the option around the various address types --- */
386 if (ss
->a
->ops
->option
&& ss
->a
->ops
->option(sc
, ss
->ao
, ADDR_SRC
))
390 for (a
= addrs
; *a
; a
++) {
391 if ((*a
)->option
&& (*a
)->option(sc
, 0, ADDR_GLOBAL
))
396 /* --- Nobody understood the option --- */
403 static source
*ssource_read(scanner
*sc
)
407 (void)(conf_prefix(sc
, "socket") || conf_prefix(sc
, "sk"));
408 ss
= CREATE(ssource
);
409 ss
->s
.ops
= &ssource_ops
;
412 ss
->a
= getaddr(sc
, ADDR_SRC
);
413 if (ss
->a
->ops
->initsrcopts
)
414 ss
->ao
= ss
->a
->ops
->initsrcopts();
416 ss
->ao
= CREATE(addr_opts
);
422 /* --- @ss_accept@ --- *
424 * Arguments: @int fd@ = file descriptor to accept from
425 * @unsigned mode@ = what's ready with the descriptor
426 * @void *p@ = pointer to the source definition
430 * Use: Accepts an incoming connection and attaches it to a target
434 static void ssource_destroy(source */
*s*/
);
436 static void ss_accept(int fd
, unsigned mode
, void *p
)
443 /* --- Make the file descriptor --- */
447 if ((r
= ss
->a
->ops
->accept(fd
, ss
->ao
, ss
->s
.desc
)) == 0)
449 setsockopt(r
->fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
450 fdflags(r
->fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
453 /* --- Make an endpoint --- */
456 e
->e
.ops
= &ssept_ops
;
460 e
->e
.in
= e
->e
.out
= r
;
464 /* --- Obtain the target endpoint and let rip --- */
466 if ((ee
= ss
->t
->ops
->create(ss
->t
, ss
->s
.desc
)) == 0) {
474 /* --- Remove the listening socket if necessary --- */
480 if (!(ss
->ao
->f
& ADDRF_NOLOG
))
481 fw_log(-1, "[%s] maximum connections reached", ss
->s
.desc
);
484 if (ss
->a
->ops
->unbind
)
485 ss
->a
->ops
->unbind(ss
->a
);
488 case SOCKOPT_NOLIMIT
:
490 case SOCKOPT_ONESHOT
:
493 if (ss
->a
->ops
->unbind
)
494 ss
->a
->ops
->unbind(ss
->a
);
495 ssource_destroy(&ss
->s
);
499 /* --- Let everything else happen --- */
501 endpt_join(&e
->e
, ee
);
504 /* --- @ss_listen@ --- *
506 * Arguments: @ssource *ss@ = source to listen on
510 * Use: Sets the socket to listen again, if it stopped for some
511 * reason. This is a copy of the code in the @read@ function,
512 * because it has different (wildly different) error handling
516 static void ss_listen(ssource
*ss
)
521 if (!(ss
->ao
->f
& ADDRF_NOLOG
))
522 fw_log(-1, "[%s] reattaching listener", ss
->s
.desc
);
524 /* --- Make the socket --- */
526 if ((fd
= ss
->a
->ops
->bind(ss
->a
, ss
->ao
)) < 0) {
527 fw_log(-1, "[%s] couldn't create socket: %s",
528 ss
->s
.desc
, strerror(errno
));
532 /* --- Set it to listen for connections --- */
534 setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
535 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
536 if (listen(fd
, ss
->o
.listen
)) {
537 fw_log(-1, "[%s] couldn't listen on socket: %s",
538 ss
->s
.desc
, strerror(errno
));
542 /* --- Set the listener up again --- */
548 /* --- Tidy up if it failed --- *
550 * I'll just remove the entire source.
557 ssource_destroy(&ss
->s
);
560 /* --- @attach@ --- */
562 static void ssource_attach(source
*s
, scanner
*sc
, target
*t
)
564 ssource
*ss
= (ssource
*)s
;
570 /* --- Initialize the description string --- */
574 dstr_puts(&d
, "socket.");
575 ss
->a
->ops
->print(ss
->a
, ADDR_SRC
, &d
);
576 dstr_puts(&d
, " -> ");
577 dstr_puts(&d
, ss
->t
->desc
);
578 ss
->s
.desc
= xstrdup(d
.buf
);
582 /* --- Confirm the address --- */
584 if (ss
->a
->ops
->confirm
)
585 ss
->a
->ops
->confirm(ss
->a
, ADDR_SRC
, ss
->ao
);
587 /* --- Initialize the socket for listening --- */
589 if ((fd
= ss
->a
->ops
->bind(ss
->a
, ss
->ao
)) < 0)
590 error(sc
, "couldn't bind socket `%s': %s", ss
->s
.desc
, strerror(errno
));
592 /* --- Set it to listen for connections --- */
594 setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
595 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
596 if (listen(fd
, ss
->o
.listen
)) {
597 error(sc
, "couldn't listen on socket `%s': %s",
598 ss
->s
.desc
, strerror(errno
));
601 /* --- We're ready to go now --- */
603 sel_initfile(sel
, &ss
->r
, fd
, SEL_READ
, ss_accept
, ss
);
609 /* --- @destroy@ --- */
611 static void ssource_destroy(source
*s
)
613 ssource
*ss
= (ssource
*)s
;
615 if (ss
->o
.conn
|| ss
->o
.opt
!= SOCKOPT_LIMIT
) {
618 if (ss
->a
->ops
->unbind
)
619 ss
->a
->ops
->unbind(ss
->a
);
621 if (ss
->a
->ops
->freesrcopts
)
622 ss
->a
->ops
->freesrcopts(ss
->ao
);
626 ss
->a
->ops
->destroy(ss
->a
);
627 ss
->t
->ops
->destroy(ss
->t
);
628 source_remove(&ss
->s
);
633 /* --- Source definition block --- */
635 source_ops ssource_ops
= {
637 ssource_option
, ssource_read
, ssource_attach
, ssource_destroy
640 /*----- Target definition -------------------------------------------------*/
642 /* --- @options@ --- */
644 static int starget_option(target
*t
, scanner
*sc
)
646 starget
*st
= (starget
*)t
;
648 CONF_BEGIN(sc
, "starget", "socket target")
650 /* --- Pass the option around the various address types --- */
653 if (st
->a
->ops
->option
&& st
->a
->ops
->option(sc
, st
->ao
, ADDR_DEST
))
656 /* We'd have done it already if it was global */
665 static target
*starget_read(scanner
*sc
)
670 (void)(conf_prefix(sc
, "socket") || conf_prefix(sc
, "sk"));
671 st
= CREATE(starget
);
672 st
->t
.ops
= &starget_ops
;
673 st
->a
= getaddr(sc
, ADDR_DEST
);
674 if (st
->a
->ops
->inittargopts
)
675 st
->ao
= st
->a
->ops
->inittargopts();
677 st
->ao
= CREATE(addr_opts
);
679 dstr_puts(&d
, "socket.");
680 st
->a
->ops
->print(st
->a
, ADDR_DEST
, &d
);
681 st
->t
.desc
= xstrdup(d
.buf
);
686 /* --- @confirm@ --- */
688 static void starget_confirm(target
*t
)
690 starget
*st
= (starget
*)t
;
692 if (st
->a
->ops
->confirm
)
693 st
->a
->ops
->confirm(st
->a
, ADDR_DEST
, st
->ao
);
696 /* --- @create@ --- */
698 static endpt
*starget_create(target
*t
, const char *desc
)
700 starget
*st
= (starget
*)t
;
701 stept
*e
= CREATE(stept
);
703 e
->e
.ops
= &stept_ops
;
705 e
->e
.f
= EPF_FILE
| EPF_PENDING
;
707 e
->desc
= xstrdup(desc
);
708 if (st
->a
->ops
->connect(st
->a
, st
->ao
, &e
->c
, &e
->e
)) {
709 fw_log(-1, "[%s] couldn't connect: %s", e
->desc
, strerror(errno
));
717 /* --- @destroy@ --- */
719 static void starget_destroy(target
*t
)
721 starget
*st
= (starget
*)t
;
722 if (st
->a
->ops
->freetargopts
)
723 st
->a
->ops
->freetargopts(st
->ao
);
726 st
->a
->ops
->destroy(st
->a
);
731 /* --- Socket target definition block --- */
733 target_ops starget_ops
= {
735 starget_option
, starget_read
, starget_confirm
,
736 starget_create
, starget_destroy
739 /*----- That's all, folks -------------------------------------------------*/