3 * $Id: socket.c,v 1.2 1999/07/27 18:30:53 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 1.2 1999/07/27 18:30:53 mdw
33 * Various minor portability fixes.
35 * Revision 1.1 1999/07/26 23:33:32 mdw
36 * New sources and targets.
40 /*----- Header files ------------------------------------------------------*/
50 #include <sys/types.h>
53 #include <sys/socket.h>
54 #include <netinet/in.h>
55 #include <arpa/inet.h>
58 #include <mLib/alloc.h>
59 #include <mLib/conn.h>
60 #include <mLib/dstr.h>
61 #include <mLib/fdflags.h>
76 /*----- Data structures ---------------------------------------------------*/
78 /* --- Socket source options --- */
80 typedef struct ssource_opts
{
84 static ssource_opts ssgo
= { 256 };
86 /* --- Socket source --- */
88 typedef struct ssource
{
97 /* --- Socket target --- */
99 typedef struct starget
{
105 /* --- Socket target endpoint --- */
107 typedef struct stept
{
113 /* --- Socket source endpoint --- */
115 typedef struct ssept
{
121 #define SKF_BROKEN 32u
123 /*----- Protocol table ----------------------------------------------------*/
125 static addr_ops
*addrs
[] = { &inet_ops
, &un_ops
, 0 };
127 /*----- Other persistent variables ----------------------------------------*/
129 static addr_opts gao
= { 0 };
131 /*----- Parsing address types ---------------------------------------------*/
133 /* --- @getaddrtype@ --- *
135 * Arguments: @scanner *sc@ = pointer to scanner (for error reporting)
136 * @const char *p@ = pointer to protocol name
137 * @int abbrev@ = nonzero to allow abbreviations
139 * Returns: Pointer to address operations table or null.
141 * Use: Looks up a protocol name. Handy when parsing addresses and
142 * other bits of configuration. Returns null if no matching
146 static addr_ops
*getaddrtype(scanner
*sc
, const char *p
, int abbrev
)
149 addr_ops
*chosen
= 0;
150 size_t sz
= strlen(p
);
152 for (ops
= addrs
; *ops
; ops
++) {
153 if (strncmp((*ops
)->name
, p
, sz
) == 0) {
154 if ((*ops
)->name
[sz
] == 0)
156 else if (chosen
&& abbrev
)
157 error(sc
, "ambiguous socket address type `%s'", p
);
166 /* --- @getaddr@ --- *
168 * Arguments: @scanner *sc@ = pointer to scanner to read from
169 * @unsigned type@ = address type (@ADDR_SRC@ or @ADDR_DEST@)
171 * Returns: Pointer to an address successfully read.
173 * Use: Reads an optionally qualified address.
176 static addr
*getaddr(scanner
*sc
, unsigned type
)
185 if (sc
->t
== CTOK_WORD
)
186 ops
= getaddrtype(sc
, sc
->d
.buf
, abbrev
);
190 error(sc
, "unknown socket address type `%s'", sc
->d
.buf
);
196 return (ops
->read(sc
, type
));
199 /*----- Socket endpoints --------------------------------------------------*/
201 /* --- @wclose@ --- */
203 static void sept_wclose(endpt
*e
)
205 shutdown(e
->out
->fd
, 1);
208 /* --- @close@ (source) --- */
210 static void ss_listen(ssource */
*ss*/
);
212 static void ssept_close(endpt
*e
)
214 ssept
*ee
= (ssept
*)e
;
216 if (!ee
->s
->o
.conn
) {
222 REFFD_DEC(ee
->e
.out
);
227 /* --- @close@ (target) --- */
229 static void stept_close(endpt
*e
)
231 stept
*ee
= (stept
*)e
;
233 if (ee
->e
.f
& EPF_PENDING
) {
234 if (ee
->e
.f
& SKF_CONN
)
238 REFFD_DEC(ee
->e
.out
);
245 /* --- @stept_go@ --- *
247 * Arguments: @int fd@ = file descriptor now ready for use
248 * @void *p@ = pointer to an endpoint structure
252 * Use: Handles successful connection of the target endpoint.
255 static void stept_go(int fd
, void *p
)
259 /* --- Complicated and subtle --- *
261 * This code interacts quite closely with @starget_create@, mainly through
262 * flags in the endpoint block.
264 * If the connection failed, I log a message (that's easy enough). The
265 * behaviour then depends on whether the endpoints have been joined yet.
266 * If not, I set @SKF_BROKEN@ and return, so that @starget_create@ can
267 * clean up the mess and return an immediate failure. If they have, I kill
268 * the connection and everything ought to work.
270 * If the connection worked, I clear @EPF_PENDING@ (as expected, because
271 * my endpoint is now ready), and @SKF_CONN@ (to let @starget_create@ know
272 * that the connection is already going). Then, only if this isn't the
273 * first attempt, I rejoin this endpoint to its partner.
277 fw_log(-1, "[%s] connection failed: %s", e
->desc
, strerror(errno
));
279 if (e
->e
.f
& EPF_PENDING
)
282 e
->e
.f
|= SKF_BROKEN
;
284 reffd
*r
= reffd_init(fd
);
286 e
->e
.in
= e
->e
.out
= r
;
287 e
->e
.f
&= ~(EPF_PENDING
| SKF_CONN
);
289 endpt_join(&e
->e
, e
->e
.other
);
293 /* --- Socket endpoint definition --- */
295 static endpt_ops ssept_ops
= {
296 0, sept_wclose
, ssept_close
299 static endpt_ops stept_ops
= {
300 0, sept_wclose
, stept_close
303 /*----- Source definition -------------------------------------------------*/
305 /* --- @option@ --- */
307 static int ssource_option(source
*s
, scanner
*sc
)
309 ssource
*ss
= (ssource
*)s
;
310 ssource_opts
*sso
= ss ?
&ss
->o
: &ssgo
;
312 CONF_BEGIN(sc
, "socket", "socket")
314 /* --- Make sure the next token is a word --- */
316 if (sc
->t
!= CTOK_WORD
)
317 error(sc
, "parse error, option keyword expected");
319 /* --- Handle options at this level --- */
321 if (strcmp(sc
->d
.buf
, "conn") == 0) {
325 if (sc
->t
!= CTOK_WORD
|| !isdigit((unsigned char)sc
->d
.buf
[0]))
326 error(sc
, "parse error, argument of `conn' must be a number");
327 sso
->conn
= atoi(sc
->d
.buf
);
329 error(sc
, "argument of `conn' must be positive");
334 if (strcmp(sc
->d
.buf
, "logging") == 0 ||
335 strcmp(sc
->d
.buf
, "log") == 0) {
336 addr_opts
*ao
= ss ? ss
->ao
: &gao
;
340 if (conf_enum(sc
, "no,yes", ENUM_ABBREV
, "logging status"))
341 ao
->f
&= ~ADDRF_NOLOG
;
343 ao
->f
|= ADDRF_NOLOG
;
347 /* --- Pass the option around the various address types --- */
350 if (ss
->a
->ops
->option
&& ss
->a
->ops
->option(sc
, ss ? ss
->ao
: 0))
354 for (a
= addrs
; *a
; a
++) {
355 if ((*a
)->option
&& (*a
)->option(sc
, 0))
360 /* --- Nobody understood the option --- */
367 static source
*ssource_read(scanner
*sc
)
371 (void)(conf_prefix(sc
, "socket") || conf_prefix(sc
, "sk"));
372 ss
= CREATE(ssource
);
373 ss
->s
.ops
= &ssource_ops
;
376 ss
->a
= getaddr(sc
, ADDR_SRC
);
377 if (ss
->a
->ops
->initopts
)
378 ss
->ao
= ss
->a
->ops
->initopts();
380 ss
->ao
= CREATE(addr_opts
);
386 /* --- @ss_accept@ --- *
388 * Arguments: @int fd@ = file descriptor to accept from
389 * @unsigned mode@ = what's ready with the descriptor
390 * @void *p@ = pointer to the source definition
394 * Use: Accepts an incoming connection and attaches it to a target
398 static void ss_accept(int fd
, unsigned mode
, void *p
)
405 /* --- Make the file descriptor --- */
409 if ((r
= ss
->a
->ops
->accept(fd
, ss
->ao
, ss
->s
.desc
)) == 0)
411 setsockopt(r
->fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
412 fdflags(r
->fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
415 /* --- Make an endpoint --- */
418 e
->e
.ops
= &ssept_ops
;
422 e
->e
.in
= e
->e
.out
= r
;
426 /* --- Obtain the target endpoint and let rip --- */
428 if ((ee
= ss
->t
->ops
->create(ss
->t
, ss
->s
.desc
)) == 0) {
435 /* --- Remove the listening socket if necessary --- */
439 fw_log(-1, "[%s] maximum connections reached", ss
->s
.desc
);
442 if (ss
->a
->ops
->unbind
)
443 ss
->a
->ops
->unbind(ss
->a
);
446 /* --- Let everything else happen --- */
449 endpt_join(&e
->e
, ee
);
452 /* --- @ss_listen@ --- *
454 * Arguments: @ssource *ss@ = source to listen on
458 * Use: Sets the socket to listen again, if it stopped for some
459 * reason. This is a copy of the code in the @read@ function,
460 * because it has different (wildly different) error handling
464 static void ssource_destroy(source */
*s*/
);
466 static void ss_listen(ssource
*ss
)
468 gen_addr
*ga
= (gen_addr
*)ss
->a
;
471 fw_log(-1, "[%s] reattaching listener", ss
->s
.desc
);
473 /* --- Make the socket --- */
475 if ((fd
= socket(ga
->a
.ops
->pf
, SOCK_STREAM
, 0)) < 0) {
476 fw_log(-1, "[%s] couldn't create socket: %s",
477 ss
->s
.desc
, strerror(errno
));
481 /* --- Set it to allow address reuse --- */
485 setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &opt
, sizeof(opt
));
486 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
489 /* --- Bind it to the right port --- */
491 if (bind(fd
, &ga
->sa
, ga
->a
.sz
)) {
492 fw_log(-1, "[%s] couldn't bind to %s: %s", ss
->s
.desc
, strerror(errno
));
495 if (ga
->a
.ops
->bound
)
496 ga
->a
.ops
->bound(&ga
->a
, ss
->ao
);
498 /* --- Set it to listen for connections --- */
501 fw_log(-1, "[%s] couldn't listen on socket: %s",
502 ss
->s
.desc
, strerror(errno
));
506 /* --- Set the listener up again --- */
512 /* --- Tidy up if it failed --- *
514 * I'll just remove the entire source.
521 ssource_destroy(&ss
->s
);
524 /* --- @attach@ --- */
526 static void ssource_attach(source
*s
, scanner
*sc
, target
*t
)
528 ssource
*ss
= (ssource
*)s
;
533 /* --- Initialize the description string --- */
537 dstr_puts(&d
, "socket.");
538 ss
->a
->ops
->print(ss
->a
, ADDR_SRC
, &d
);
539 dstr_puts(&d
, " -> ");
540 dstr_puts(&d
, ss
->t
->desc
);
541 ss
->s
.desc
= xstrdup(d
.buf
);
545 /* --- Initialize the socket for listening --- */
548 gen_addr
*ga
= (gen_addr
*)ss
->a
;
550 /* --- Make the socket --- */
552 if ((fd
= socket(ga
->a
.ops
->pf
, SOCK_STREAM
, 0)) < 0)
553 error(sc
, "couldn't create socket: %s", strerror(errno
));
555 /* --- Set it to allow address reuse --- */
559 setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &opt
, sizeof(opt
));
560 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
563 /* --- Bind it to the right port --- */
565 if (bind(fd
, &ga
->sa
, ga
->a
.sz
))
566 error(sc
, "couldn't bind to %s: %s", ss
->s
.desc
, strerror(errno
));
567 if (ga
->a
.ops
->bound
)
568 ga
->a
.ops
->bound(&ga
->a
, ss
->ao
);
570 /* --- Set it to listen for connections --- */
573 error(sc
, "couldn't listen on socket: %s", strerror(errno
));
576 /* --- We're ready to go now --- */
578 sel_initfile(sel
, &ss
->r
, fd
, SEL_READ
, ss_accept
, ss
);
584 /* --- @destroy@ --- */
586 static void ssource_destroy(source
*s
)
588 ssource
*ss
= (ssource
*)s
;
593 if (ss
->a
->ops
->unbind
)
594 ss
->a
->ops
->unbind(ss
->a
);
596 if (ss
->a
->ops
->freeopts
)
597 ss
->a
->ops
->freeopts(ss
->ao
);
600 /* free(ss->s.desc); */
601 ss
->a
->ops
->destroy(ss
->a
);
602 ss
->t
->ops
->destroy(ss
->t
);
603 source_remove(&ss
->s
);
608 /* --- Source definition block --- */
610 source_ops ssource_ops
= {
612 ssource_option
, ssource_read
, ssource_attach
, ssource_destroy
615 /*----- Target definition -------------------------------------------------*/
619 static target
*starget_read(scanner
*sc
)
624 (void)(conf_prefix(sc
, "socket") || conf_prefix(sc
, "sk"));
625 st
= CREATE(starget
);
626 st
->t
.ops
= &starget_ops
;
627 st
->a
= getaddr(sc
, ADDR_DEST
);
628 dstr_puts(&d
, "socket.");
629 st
->a
->ops
->print(st
->a
, ADDR_DEST
, &d
);
630 st
->t
.desc
= xstrdup(d
.buf
);
635 /* --- @create@ --- *
637 * Arguments: @target *t@ = pointer to target
638 * @const char *desc@ = description of connection
640 * Returns: Pointer to a created endpoint.
642 * Use: Generates a target endpoint for communication.
645 static endpt
*starget_create(target
*t
, const char *desc
)
647 starget
*st
= (starget
*)t
;
648 stept
*e
= CREATE(stept
);
650 gen_addr
*ga
= (gen_addr
*)st
->a
;
653 if ((fd
= socket(st
->a
->ops
->pf
, SOCK_STREAM
, 0)) < 0)
655 setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &opt
, sizeof(opt
));
656 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
657 e
->e
.ops
= &stept_ops
;
659 e
->e
.f
= EPF_FILE
| SKF_CONN
;
663 /* --- Pay attention --- *
665 * This bit is quite subtle. The connect can succeed or fail later: that's
666 * fine. The problem comes if it makes its mind up right now. The flag
667 * @SKF_CONN@ signifies that I'm trying to connect. I set it up to begin
668 * with and @stept_go@ turns it off when it's done: @stept_close@ uses it
669 * to decide whether to kill the connection. The flag @EPF_PENDING@ is
670 * only set after @conn_init@ returns and @SKF_CONN@ is still set (meaning
671 * that the connection is still in progress). That's used to let
672 * @stept_go@ know whether to kill the other endpoint. The flag
673 * @SKF_BROKEN@ is used to signify an immediate failure.
676 conn_init(&e
->c
, sel
, fd
, &ga
->sa
, ga
->a
.sz
, stept_go
, e
);
677 if (e
->e
.f
& SKF_BROKEN
) {
681 if (e
->e
.f
& SKF_CONN
)
682 e
->e
.f
|= EPF_PENDING
;
687 /* --- @destroy@ --- */
689 static void starget_destroy(target
*t
)
691 starget
*st
= (starget
*)t
;
692 st
->a
->ops
->destroy(st
->a
);
693 /* free(st->t.desc); */
697 /* --- Socket target definition block --- */
699 target_ops starget_ops
= {
701 0, starget_read
, starget_create
, starget_destroy
704 /*----- That's all, folks -------------------------------------------------*/