2 Socket wrapper library. Passes all socket communication over
3 unix domain sockets if the environment variable SOCKET_WRAPPER_DIR
5 Copyright (C) Jelmer Vernooij 2005
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #ifdef SOCKET_WRAPPER_REPLACE
43 /* LD_PRELOAD doesn't work yet, so REWRITE_CALLS is all we support
48 #define real_accept accept
49 #define real_connect connect
50 #define real_bind bind
51 #define real_getpeername getpeername
52 #define real_getsockname getsockname
53 #define real_getsockopt getsockopt
54 #define real_setsockopt setsockopt
55 #define real_recvfrom recvfrom
56 #define real_sendto sendto
57 #define real_socket socket
58 #define real_close close
64 /* we need to use a very terse format here as IRIX 6.4 silently
65 truncates names to 16 chars, so if we use a longer name then we
66 can't tell which port a packet came from with recvfrom()
68 with this format we have 8 chars left for the directory name
70 #define SOCKET_FORMAT "%c%02X%04X"
71 #define SOCKET_TYPE_CHAR_TCP 'T'
72 #define SOCKET_TYPE_CHAR_UDP 'U'
74 static struct sockaddr *sockaddr_dup(const void *data, socklen_t len)
76 struct sockaddr *ret = (struct sockaddr *)malloc(len);
77 memcpy(ret, data, len);
94 struct sockaddr *myname;
97 struct sockaddr *peername;
98 socklen_t peername_len;
100 struct socket_info *prev, *next;
103 static struct socket_info *sockets = NULL;
106 static const char *socket_wrapper_dir(void)
108 const char *s = getenv("SOCKET_WRAPPER_DIR");
112 if (strncmp(s, "./", 2) == 0) {
118 static unsigned int socket_wrapper_default_iface(void)
120 const char *s = getenv("SOCKET_WRAPPER_DEFAULT_IFACE");
123 if (sscanf(s, "%u", &iface) == 1) {
124 if (iface >= 1 && iface <= 0xFF) {
130 return 1;/* 127.0.0.1 */
133 static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len)
140 if ((*len) < sizeof(struct sockaddr_in)) {
144 p = strrchr(un->sun_path, '/');
145 if (p) p++; else p = un->sun_path;
147 if (sscanf(p, SOCKET_FORMAT, &type, &iface, &prt) != 3) {
152 if (type != SOCKET_TYPE_CHAR_TCP && type != SOCKET_TYPE_CHAR_UDP) {
157 if (iface == 0 || iface > 0xFF) {
167 in->sin_family = AF_INET;
168 in->sin_addr.s_addr = htonl((127<<24) | iface);
169 in->sin_port = htons(prt);
171 *len = sizeof(struct sockaddr_in);
175 static int convert_in_un_remote(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un,
182 unsigned int addr= ntohl(in->sin_addr.s_addr);
183 unsigned int prt = ntohs(in->sin_port);
187 if (bcast) *bcast = 0;
196 u_type = SOCKET_TYPE_CHAR_TCP;
199 u_type = SOCKET_TYPE_CHAR_UDP;
200 a_type = SOCKET_TYPE_CHAR_UDP;
201 b_type = SOCKET_TYPE_CHAR_UDP;
205 if (a_type && addr == 0xFFFFFFFF) {
206 /* 255.255.255.255 only udp */
209 iface = socket_wrapper_default_iface();
210 } else if (b_type && addr == 0x7FFFFFFF) {
211 /* 127.255.255.255 only udp */
214 iface = socket_wrapper_default_iface();
215 } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
219 iface = (addr & 0x000000FF);
225 if (bcast) *bcast = is_bcast;
228 snprintf(un->sun_path, sizeof(un->sun_path), "%s/EINVAL",
229 socket_wrapper_dir());
230 /* the caller need to do more processing */
234 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
235 socket_wrapper_dir(), type, iface, prt);
240 static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un,
248 unsigned int addr= ntohl(in->sin_addr.s_addr);
249 unsigned int prt = ntohs(in->sin_port);
254 if (bcast) *bcast = 0;
258 u_type = SOCKET_TYPE_CHAR_TCP;
259 d_type = SOCKET_TYPE_CHAR_TCP;
262 u_type = SOCKET_TYPE_CHAR_UDP;
263 d_type = SOCKET_TYPE_CHAR_UDP;
264 a_type = SOCKET_TYPE_CHAR_UDP;
265 b_type = SOCKET_TYPE_CHAR_UDP;
273 iface = socket_wrapper_default_iface();
274 } else if (a_type && addr == 0xFFFFFFFF) {
275 /* 255.255.255.255 only udp */
278 iface = socket_wrapper_default_iface();
279 } else if (b_type && addr == 0x7FFFFFFF) {
280 /* 127.255.255.255 only udp */
283 iface = socket_wrapper_default_iface();
284 } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
288 iface = (addr & 0x000000FF);
290 errno = EADDRNOTAVAIL;
294 if (bcast) *bcast = is_bcast;
297 /* handle auto-allocation of ephemeral ports */
298 for (prt = 5001; prt < 10000; prt++) {
299 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
300 socket_wrapper_dir(), type, iface, prt);
301 if (stat(un->sun_path, &st) == 0) continue;
303 ((struct sockaddr_in *)si->myname)->sin_port = htons(prt);
310 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
311 socket_wrapper_dir(), type, iface, prt);
315 static struct socket_info *find_socket_info(int fd)
317 struct socket_info *i;
318 for (i = sockets; i; i = i->next) {
326 static int sockaddr_convert_to_un(struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len,
327 struct sockaddr_un *out_addr, int alloc_sock, int *bcast)
332 out_addr->sun_family = AF_UNIX;
334 switch (in_addr->sa_family) {
341 errno = ESOCKTNOSUPPORT;
345 return convert_in_un_alloc(si, (const struct sockaddr_in *)in_addr, out_addr, bcast);
347 return convert_in_un_remote(si, (const struct sockaddr_in *)in_addr, out_addr, bcast);
350 memcpy(out_addr, in_addr, sizeof(*out_addr));
356 errno = EAFNOSUPPORT;
360 static int sockaddr_convert_from_un(const struct socket_info *si,
361 const struct sockaddr_un *in_addr,
362 socklen_t un_addrlen,
364 struct sockaddr *out_addr,
365 socklen_t *_out_addrlen)
367 socklen_t out_addrlen;
369 if (out_addr == NULL || _out_addrlen == NULL)
372 if (un_addrlen == 0) {
377 out_addrlen = *_out_addrlen;
378 if (out_addrlen > un_addrlen) {
379 out_addrlen = un_addrlen;
389 errno = ESOCKTNOSUPPORT;
392 return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, _out_addrlen);
394 memcpy(out_addr, in_addr, out_addrlen);
395 *_out_addrlen = out_addrlen;
401 errno = EAFNOSUPPORT;
405 _PUBLIC_ int swrap_socket(int domain, int type, int protocol)
407 struct socket_info *si;
410 if (!socket_wrapper_dir()) {
411 return real_socket(domain, type, protocol);
414 si = (struct socket_info *)calloc(1, sizeof(struct socket_info));
420 fd = real_socket(AF_UNIX, type, 0);
422 if (fd == -1) return -1;
426 si->protocol = protocol;
429 DLIST_ADD(sockets, si);
434 _PUBLIC_ int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
436 struct socket_info *parent_si, *child_si;
438 struct sockaddr_un un_addr;
439 socklen_t un_addrlen = sizeof(un_addr);
440 struct sockaddr_un un_my_addr;
441 socklen_t un_my_addrlen = sizeof(un_my_addr);
442 struct sockaddr my_addr;
443 socklen_t my_addrlen = sizeof(my_addr);
446 parent_si = find_socket_info(s);
448 return real_accept(s, addr, addrlen);
451 memset(&un_addr, 0, sizeof(un_addr));
452 memset(&un_my_addr, 0, sizeof(un_my_addr));
453 memset(&my_addr, 0, sizeof(my_addr));
455 ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
456 if (ret == -1) return ret;
460 ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
461 parent_si->domain, addr, addrlen);
462 if (ret == -1) return ret;
464 child_si = (struct socket_info *)malloc(sizeof(struct socket_info));
465 if (child_si == NULL) {
470 memset(child_si, 0, sizeof(*child_si));
473 child_si->domain = parent_si->domain;
474 child_si->type = parent_si->type;
475 child_si->protocol = parent_si->protocol;
478 ret = real_getsockname(fd, (struct sockaddr *)&un_my_addr, &un_my_addrlen);
479 if (ret == -1) return ret;
481 ret = sockaddr_convert_from_un(child_si, &un_my_addr, un_my_addrlen,
482 child_si->domain, &my_addr, &my_addrlen);
483 if (ret == -1) return ret;
485 child_si->myname_len = my_addrlen;
486 child_si->myname = sockaddr_dup(&my_addr, my_addrlen);
488 child_si->peername_len = *addrlen;
489 child_si->peername = sockaddr_dup(addr, *addrlen);
491 DLIST_ADD(sockets, child_si);
496 /* using sendto() or connect() on an unbound socket would give the
497 recipient no way to reply, as unlike UDP and TCP, a unix domain
498 socket can't auto-assign emphemeral port numbers, so we need to
500 static int swrap_auto_bind(struct socket_info *si)
502 struct sockaddr_un un_addr;
503 struct sockaddr_in in;
509 un_addr.sun_family = AF_UNIX;
513 type = SOCKET_TYPE_CHAR_TCP;
516 type = SOCKET_TYPE_CHAR_UDP;
519 errno = ESOCKTNOSUPPORT;
523 for (i=0;i<1000;i++) {
524 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path),
525 "%s/"SOCKET_FORMAT, socket_wrapper_dir(),
526 type, socket_wrapper_default_iface(), i + 10000);
527 if (stat(un_addr.sun_path, &st) == 0) continue;
529 ret = real_bind(si->fd, (struct sockaddr *)&un_addr, sizeof(un_addr));
530 if (ret == -1) return ret;
532 si->tmp_path = strdup(un_addr.sun_path);
541 memset(&in, 0, sizeof(in));
542 in.sin_family = AF_INET;
543 in.sin_port = htons(i);
544 in.sin_addr.s_addr = htonl(127<<24 | socket_wrapper_default_iface());
546 si->myname_len = sizeof(in);
547 si->myname = sockaddr_dup(&in, si->myname_len);
553 _PUBLIC_ int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
556 struct sockaddr_un un_addr;
557 struct socket_info *si = find_socket_info(s);
560 return real_connect(s, serv_addr, addrlen);
563 if (si->bound == 0 && si->domain != AF_UNIX) {
564 ret = swrap_auto_bind(si);
565 if (ret == -1) return -1;
568 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr, 0, NULL);
569 if (ret == -1) return -1;
571 ret = real_connect(s, (struct sockaddr *)&un_addr,
572 sizeof(struct sockaddr_un));
574 /* to give better errors */
575 if (serv_addr->sa_family == AF_INET) {
576 if (ret == -1 && errno == ENOENT) {
577 errno = EHOSTUNREACH;
582 si->peername_len = addrlen;
583 si->peername = sockaddr_dup(serv_addr, addrlen);
589 _PUBLIC_ int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
592 struct sockaddr_un un_addr;
593 struct socket_info *si = find_socket_info(s);
596 return real_bind(s, myaddr, addrlen);
599 si->myname_len = addrlen;
600 si->myname = sockaddr_dup(myaddr, addrlen);
602 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr, 1, &si->bcast);
603 if (ret == -1) return -1;
605 unlink(un_addr.sun_path);
607 ret = real_bind(s, (struct sockaddr *)&un_addr,
608 sizeof(struct sockaddr_un));
617 _PUBLIC_ int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
619 struct socket_info *si = find_socket_info(s);
622 return real_getpeername(s, name, addrlen);
631 memcpy(name, si->peername, si->peername_len);
632 *addrlen = si->peername_len;
637 _PUBLIC_ int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
639 struct socket_info *si = find_socket_info(s);
642 return real_getsockname(s, name, addrlen);
645 memcpy(name, si->myname, si->myname_len);
646 *addrlen = si->myname_len;
651 _PUBLIC_ int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
653 struct socket_info *si = find_socket_info(s);
656 return real_getsockopt(s, level, optname, optval, optlen);
659 if (level == SOL_SOCKET) {
660 return real_getsockopt(s, level, optname, optval, optlen);
663 switch (si->domain) {
665 return real_getsockopt(s, level, optname, optval, optlen);
672 _PUBLIC_ int swrap_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
674 struct socket_info *si = find_socket_info(s);
677 return real_setsockopt(s, level, optname, optval, optlen);
680 if (level == SOL_SOCKET) {
681 return real_setsockopt(s, level, optname, optval, optlen);
684 switch (si->domain) {
686 return real_setsockopt(s, level, optname, optval, optlen);
688 /* Silence some warnings */
690 if (optname == TCP_NODELAY)
699 _PUBLIC_ ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
701 struct sockaddr_un un_addr;
702 socklen_t un_addrlen = sizeof(un_addr);
704 struct socket_info *si = find_socket_info(s);
707 return real_recvfrom(s, buf, len, flags, from, fromlen);
710 /* irix 6.4 forgets to null terminate the sun_path string :-( */
711 memset(&un_addr, 0, sizeof(un_addr));
712 ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
716 if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
717 si->domain, from, fromlen) == -1) {
725 _PUBLIC_ ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
727 struct sockaddr_un un_addr;
729 struct socket_info *si = find_socket_info(s);
733 return real_sendto(s, buf, len, flags, to, tolen);
736 if (si->bound == 0 && si->domain != AF_UNIX) {
737 ret = swrap_auto_bind(si);
738 if (ret == -1) return -1;
741 ret = sockaddr_convert_to_un(si, to, tolen, &un_addr, 0, &bcast);
742 if (ret == -1) return -1;
747 unsigned int prt = ntohs(((const struct sockaddr_in *)to)->sin_port);
750 type = SOCKET_TYPE_CHAR_UDP;
752 for(iface=0; iface <= 0xFF; iface++) {
753 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/"SOCKET_FORMAT,
754 socket_wrapper_dir(), type, iface, prt);
755 if (stat(un_addr.sun_path, &st) != 0) continue;
757 /* ignore the any errors in broadcast sends */
758 real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
763 ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
765 /* to give better errors */
766 if (to->sa_family == AF_INET) {
767 if (ret == -1 && errno == ENOENT) {
768 errno = EHOSTUNREACH;
775 _PUBLIC_ int swrap_close(int fd)
777 struct socket_info *si = find_socket_info(fd);
780 DLIST_REMOVE(sockets, si);
786 unlink(si->tmp_path);
792 return real_close(fd);