3 * $Id: socket.c,v 1.4 1999/12/22 15:44:25 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 1.4 1999/12/22 15:44:25 mdw
35 * Revision 1.3 1999/10/22 22:48:36 mdw
36 * New connection options: unlimited concurrent connections, and one-shot
39 * Revision 1.2 1999/07/27 18:30:53 mdw
40 * Various minor portability fixes.
42 * Revision 1.1 1999/07/26 23:33:32 mdw
43 * New sources and targets.
47 /*----- Header files ------------------------------------------------------*/
58 #include <sys/types.h>
61 #include <sys/socket.h>
62 #include <netinet/in.h>
63 #include <arpa/inet.h>
66 #include <mLib/alloc.h>
67 #include <mLib/conn.h>
68 #include <mLib/dstr.h>
69 #include <mLib/fdflags.h>
84 /*----- Data structures ---------------------------------------------------*/
86 /* --- Socket source options --- */
88 typedef struct ssource_opts
{
93 static ssource_opts ssgo
= { 256, 0 };
95 #define SOCKOPT_LIMIT 0u
96 #define SOCKOPT_NOLIMIT 1u
97 #define SOCKOPT_ONESHOT 2u
99 /* --- Socket source --- */
101 typedef struct ssource
{
110 /* --- Socket target --- */
112 typedef struct starget
{
118 /* --- Socket target endpoint --- */
120 typedef struct stept
{
126 /* --- Socket source endpoint --- */
128 typedef struct ssept
{
134 #define SKF_BROKEN 32u
136 /*----- Protocol table ----------------------------------------------------*/
138 static addr_ops
*addrs
[] = { &inet_ops
, &un_ops
, 0 };
140 /*----- Other persistent variables ----------------------------------------*/
142 static addr_opts gao
= { 0 };
144 /*----- Parsing address types ---------------------------------------------*/
146 /* --- @getaddrtype@ --- *
148 * Arguments: @scanner *sc@ = pointer to scanner (for error reporting)
149 * @const char *p@ = pointer to protocol name
150 * @int abbrev@ = nonzero to allow abbreviations
152 * Returns: Pointer to address operations table or null.
154 * Use: Looks up a protocol name. Handy when parsing addresses and
155 * other bits of configuration. Returns null if no matching
159 static addr_ops
*getaddrtype(scanner
*sc
, const char *p
, int abbrev
)
162 addr_ops
*chosen
= 0;
163 size_t sz
= strlen(p
);
165 for (ops
= addrs
; *ops
; ops
++) {
166 if (strncmp((*ops
)->name
, p
, sz
) == 0) {
167 if ((*ops
)->name
[sz
] == 0)
169 else if (chosen
&& abbrev
)
170 error(sc
, "ambiguous socket address type `%s'", p
);
179 /* --- @getaddr@ --- *
181 * Arguments: @scanner *sc@ = pointer to scanner to read from
182 * @unsigned type@ = address type (@ADDR_SRC@ or @ADDR_DEST@)
184 * Returns: Pointer to an address successfully read.
186 * Use: Reads an optionally qualified address.
189 static addr
*getaddr(scanner
*sc
, unsigned type
)
198 if (sc
->t
== CTOK_WORD
)
199 ops
= getaddrtype(sc
, sc
->d
.buf
, abbrev
);
203 error(sc
, "unknown socket address type `%s'", sc
->d
.buf
);
209 return (ops
->read(sc
, type
));
212 /*----- Socket endpoints --------------------------------------------------*/
214 /* --- @wclose@ --- */
216 static void sept_wclose(endpt
*e
)
218 shutdown(e
->out
->fd
, 1);
221 /* --- @close@ (source) --- */
223 static void ss_listen(ssource */
*ss*/
);
225 static void ssept_close(endpt
*e
)
227 ssept
*ee
= (ssept
*)e
;
229 if (ee
->s
->o
.opt
== SOCKOPT_LIMIT
) {
231 if (ee
->s
->o
.conn
== 1)
235 REFFD_DEC(ee
->e
.out
);
240 /* --- @close@ (target) --- */
242 static void stept_close(endpt
*e
)
244 stept
*ee
= (stept
*)e
;
246 if (ee
->e
.f
& EPF_PENDING
) {
247 if (ee
->e
.f
& SKF_CONN
)
251 REFFD_DEC(ee
->e
.out
);
258 /* --- @stept_go@ --- *
260 * Arguments: @int fd@ = file descriptor now ready for use
261 * @void *p@ = pointer to an endpoint structure
265 * Use: Handles successful connection of the target endpoint.
268 static void stept_go(int fd
, void *p
)
272 /* --- Complicated and subtle --- *
274 * This code interacts quite closely with @starget_create@, mainly through
275 * flags in the endpoint block.
277 * If the connection failed, I log a message (that's easy enough). The
278 * behaviour then depends on whether the endpoints have been joined yet.
279 * If not, I set @SKF_BROKEN@ and return, so that @starget_create@ can
280 * clean up the mess and return an immediate failure. If they have, I kill
281 * the connection and everything ought to work.
283 * If the connection worked, I clear @EPF_PENDING@ (as expected, because
284 * my endpoint is now ready), and @SKF_CONN@ (to let @starget_create@ know
285 * that the connection is already going). Then, only if this isn't the
286 * first attempt, I rejoin this endpoint to its partner.
290 fw_log(-1, "[%s] connection failed: %s", e
->desc
, strerror(errno
));
292 if (e
->e
.f
& EPF_PENDING
)
295 e
->e
.f
|= SKF_BROKEN
;
297 reffd
*r
= reffd_init(fd
);
299 e
->e
.in
= e
->e
.out
= r
;
300 e
->e
.f
&= ~(EPF_PENDING
| SKF_CONN
);
302 endpt_join(&e
->e
, e
->e
.other
);
306 /* --- Socket endpoint definition --- */
308 static endpt_ops ssept_ops
= {
309 0, 0, sept_wclose
, ssept_close
312 static endpt_ops stept_ops
= {
313 0, 0, sept_wclose
, stept_close
316 /*----- Source definition -------------------------------------------------*/
318 /* --- @option@ --- */
320 static int ssource_option(source
*s
, scanner
*sc
)
322 ssource
*ss
= (ssource
*)s
;
323 ssource_opts
*sso
= ss ?
&ss
->o
: &ssgo
;
325 CONF_BEGIN(sc
, "socket", "socket")
327 /* --- Make sure the next token is a word --- */
329 if (sc
->t
!= CTOK_WORD
)
330 error(sc
, "parse error, option keyword expected");
332 /* --- Handle options at this level --- */
334 if (strcmp(sc
->d
.buf
, "conn") == 0) {
338 if (sc
->t
!= CTOK_WORD
)
339 error(sc
, "parse error, expected `unlimited', `one-shot' or number");
340 if (isdigit((unsigned char)sc
->d
.buf
[0])) {
341 sso
->conn
= atoi(sc
->d
.buf
);
343 error(sc
, "argument of `conn' must be positive");
344 sso
->opt
= SOCKOPT_LIMIT
;
348 sso
->opt
= 1 + (1 & conf_enum(sc
,
349 "unlimited,one-shot,infinite",
350 ENUM_ABBREV
, "`conn' option"));
355 if (strcmp(sc
->d
.buf
, "logging") == 0 ||
356 strcmp(sc
->d
.buf
, "log") == 0) {
357 addr_opts
*ao
= ss ? ss
->ao
: &gao
;
361 if (conf_enum(sc
, "no,yes", ENUM_ABBREV
, "logging status"))
362 ao
->f
&= ~ADDRF_NOLOG
;
364 ao
->f
|= ADDRF_NOLOG
;
368 /* --- Pass the option around the various address types --- */
371 if (ss
->a
->ops
->option
&& ss
->a
->ops
->option(sc
, ss ? ss
->ao
: 0))
375 for (a
= addrs
; *a
; a
++) {
376 if ((*a
)->option
&& (*a
)->option(sc
, 0))
381 /* --- Nobody understood the option --- */
388 static source
*ssource_read(scanner
*sc
)
392 (void)(conf_prefix(sc
, "socket") || conf_prefix(sc
, "sk"));
393 ss
= CREATE(ssource
);
394 ss
->s
.ops
= &ssource_ops
;
397 ss
->a
= getaddr(sc
, ADDR_SRC
);
398 if (ss
->a
->ops
->initopts
)
399 ss
->ao
= ss
->a
->ops
->initopts();
401 ss
->ao
= CREATE(addr_opts
);
407 /* --- @ss_accept@ --- *
409 * Arguments: @int fd@ = file descriptor to accept from
410 * @unsigned mode@ = what's ready with the descriptor
411 * @void *p@ = pointer to the source definition
415 * Use: Accepts an incoming connection and attaches it to a target
419 static void ssource_destroy(source */
*s*/
);
421 static void ss_accept(int fd
, unsigned mode
, void *p
)
428 /* --- Make the file descriptor --- */
432 if ((r
= ss
->a
->ops
->accept(fd
, ss
->ao
, ss
->s
.desc
)) == 0)
434 setsockopt(r
->fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
435 fdflags(r
->fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
438 /* --- Make an endpoint --- */
441 e
->e
.ops
= &ssept_ops
;
445 e
->e
.in
= e
->e
.out
= r
;
449 /* --- Obtain the target endpoint and let rip --- */
451 if ((ee
= ss
->t
->ops
->create(ss
->t
, ss
->s
.desc
)) == 0) {
459 /* --- Remove the listening socket if necessary --- */
465 if (!(ss
->ao
->f
& ADDRF_NOLOG
))
466 fw_log(-1, "[%s] maximum connections reached", ss
->s
.desc
);
469 if (ss
->a
->ops
->unbind
)
470 ss
->a
->ops
->unbind(ss
->a
);
473 case SOCKOPT_NOLIMIT
:
475 case SOCKOPT_ONESHOT
:
478 if (ss
->a
->ops
->unbind
)
479 ss
->a
->ops
->unbind(ss
->a
);
480 ssource_destroy(&ss
->s
);
484 /* --- Let everything else happen --- */
486 endpt_join(&e
->e
, ee
);
489 /* --- @ss_listen@ --- *
491 * Arguments: @ssource *ss@ = source to listen on
495 * Use: Sets the socket to listen again, if it stopped for some
496 * reason. This is a copy of the code in the @read@ function,
497 * because it has different (wildly different) error handling
501 static void ss_listen(ssource
*ss
)
503 gen_addr
*ga
= (gen_addr
*)ss
->a
;
506 if (!(ss
->ao
->f
& ADDRF_NOLOG
))
507 fw_log(-1, "[%s] reattaching listener", ss
->s
.desc
);
509 /* --- Make the socket --- */
511 if ((fd
= socket(ga
->a
.ops
->pf
, SOCK_STREAM
, 0)) < 0) {
512 fw_log(-1, "[%s] couldn't create socket: %s",
513 ss
->s
.desc
, strerror(errno
));
517 /* --- Set it to allow address reuse --- */
521 setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &opt
, sizeof(opt
));
522 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
525 /* --- Bind it to the right port --- */
527 if (bind(fd
, &ga
->sa
, ga
->a
.sz
)) {
528 fw_log(-1, "[%s] couldn't bind socket: %s", ss
->s
.desc
, strerror(errno
));
531 if (ga
->a
.ops
->bound
)
532 ga
->a
.ops
->bound(&ga
->a
, ss
->ao
);
534 /* --- Set it to listen for connections --- */
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
;
569 /* --- Initialize the description string --- */
573 dstr_puts(&d
, "socket.");
574 ss
->a
->ops
->print(ss
->a
, ADDR_SRC
, &d
);
575 dstr_puts(&d
, " -> ");
576 dstr_puts(&d
, ss
->t
->desc
);
577 ss
->s
.desc
= xstrdup(d
.buf
);
581 /* --- Initialize the socket for listening --- */
584 gen_addr
*ga
= (gen_addr
*)ss
->a
;
586 /* --- Make the socket --- */
588 if ((fd
= socket(ga
->a
.ops
->pf
, SOCK_STREAM
, 0)) < 0)
589 error(sc
, "couldn't create socket: %s", strerror(errno
));
591 /* --- Set it to allow address reuse --- */
595 setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &opt
, sizeof(opt
));
596 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
599 /* --- Bind it to the right port --- */
601 if (bind(fd
, &ga
->sa
, ga
->a
.sz
))
602 error(sc
, "couldn't bind to %s: %s", ss
->s
.desc
, strerror(errno
));
603 if (ga
->a
.ops
->bound
)
604 ga
->a
.ops
->bound(&ga
->a
, ss
->ao
);
606 /* --- Set it to listen for connections --- */
609 error(sc
, "couldn't listen on socket: %s", strerror(errno
));
612 /* --- We're ready to go now --- */
614 sel_initfile(sel
, &ss
->r
, fd
, SEL_READ
, ss_accept
, ss
);
620 /* --- @destroy@ --- */
622 static void ssource_destroy(source
*s
)
624 ssource
*ss
= (ssource
*)s
;
629 if (ss
->a
->ops
->unbind
)
630 ss
->a
->ops
->unbind(ss
->a
);
632 if (ss
->a
->ops
->freeopts
)
633 ss
->a
->ops
->freeopts(ss
->ao
);
636 /* free(ss->s.desc); */
637 ss
->a
->ops
->destroy(ss
->a
);
638 ss
->t
->ops
->destroy(ss
->t
);
639 source_remove(&ss
->s
);
644 /* --- Source definition block --- */
646 source_ops ssource_ops
= {
648 ssource_option
, ssource_read
, ssource_attach
, ssource_destroy
651 /*----- Target definition -------------------------------------------------*/
655 static target
*starget_read(scanner
*sc
)
660 (void)(conf_prefix(sc
, "socket") || conf_prefix(sc
, "sk"));
661 st
= CREATE(starget
);
662 st
->t
.ops
= &starget_ops
;
663 st
->a
= getaddr(sc
, ADDR_DEST
);
664 dstr_puts(&d
, "socket.");
665 st
->a
->ops
->print(st
->a
, ADDR_DEST
, &d
);
666 st
->t
.desc
= xstrdup(d
.buf
);
671 /* --- @create@ --- *
673 * Arguments: @target *t@ = pointer to target
674 * @const char *desc@ = description of connection
676 * Returns: Pointer to a created endpoint.
678 * Use: Generates a target endpoint for communication.
681 static endpt
*starget_create(target
*t
, const char *desc
)
683 starget
*st
= (starget
*)t
;
684 stept
*e
= CREATE(stept
);
686 gen_addr
*ga
= (gen_addr
*)st
->a
;
689 if ((fd
= socket(st
->a
->ops
->pf
, SOCK_STREAM
, 0)) < 0)
691 setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
692 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
693 e
->e
.ops
= &stept_ops
;
695 e
->e
.f
= EPF_FILE
| SKF_CONN
;
699 /* --- Pay attention --- *
701 * This bit is quite subtle. The connect can succeed or fail later: that's
702 * fine. The problem comes if it makes its mind up right now. The flag
703 * @SKF_CONN@ signifies that I'm trying to connect. I set it up to begin
704 * with and @stept_go@ turns it off when it's done: @stept_close@ uses it
705 * to decide whether to kill the connection. The flag @EPF_PENDING@ is
706 * only set after @conn_init@ returns and @SKF_CONN@ is still set (meaning
707 * that the connection is still in progress). That's used to let
708 * @stept_go@ know whether to kill the other endpoint. The flag
709 * @SKF_BROKEN@ is used to signify an immediate failure.
712 conn_init(&e
->c
, sel
, fd
, &ga
->sa
, ga
->a
.sz
, stept_go
, e
);
713 if (e
->e
.f
& SKF_BROKEN
) {
717 if (e
->e
.f
& SKF_CONN
)
718 e
->e
.f
|= EPF_PENDING
;
723 /* --- @destroy@ --- */
725 static void starget_destroy(target
*t
)
727 starget
*st
= (starget
*)t
;
728 st
->a
->ops
->destroy(st
->a
);
729 /* free(st->t.desc); */
733 /* --- Socket target definition block --- */
735 target_ops starget_ops
= {
737 0, starget_read
, starget_create
, starget_destroy
740 /*----- That's all, folks -------------------------------------------------*/