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.
25 #include "system/network.h"
26 #include "system/filesys.h"
28 #include <sys/types.h>
30 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <netinet/tcp.h>
40 #include "dlinklist.h"
42 /* LD_PRELOAD doesn't work yet, so REWRITE_CALLS is all we support
47 #define real_accept accept
48 #define real_connect connect
49 #define real_bind bind
50 #define real_getpeername getpeername
51 #define real_getsockname getsockname
52 #define real_getsockopt getsockopt
53 #define real_setsockopt setsockopt
54 #define real_recvfrom recvfrom
55 #define real_sendto sendto
56 #define real_socket socket
57 #define real_close close
60 /* we need to use a very terse format here as IRIX 6.4 silently
61 truncates names to 16 chars, so if we use a longer name then we
62 can't tell which port a packet came from with recvfrom()
64 with this format we have 8 chars left for the directory name
66 #define SOCKET_FORMAT "%c%02X%04X"
67 #define SOCKET_TYPE_CHAR_TCP 'T'
68 #define SOCKET_TYPE_CHAR_UDP 'U'
70 static struct sockaddr *sockaddr_dup(const void *data, socklen_t len)
72 struct sockaddr *ret = (struct sockaddr *)malloc(len);
73 memcpy(ret, data, len);
90 struct sockaddr *myname;
93 struct sockaddr *peername;
94 socklen_t peername_len;
96 struct socket_info *prev, *next;
99 static struct socket_info *sockets = NULL;
102 static const char *socket_wrapper_dir(void)
104 const char *s = getenv("SOCKET_WRAPPER_DIR");
108 if (strncmp(s, "./", 2) == 0) {
114 static unsigned int socket_wrapper_default_iface(void)
116 const char *s = getenv("SOCKET_WRAPPER_DEFAULT_IFACE");
119 if (sscanf(s, "%u", &iface) == 1) {
120 if (iface >= 1 && iface <= 0xFF) {
126 return 1;/* 127.0.0.1 */
129 static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len)
136 if ((*len) < sizeof(struct sockaddr_in)) {
140 p = strrchr(un->sun_path, '/');
141 if (p) p++; else p = un->sun_path;
143 if (sscanf(p, SOCKET_FORMAT, &type, &iface, &prt) != 3) {
148 if (type != SOCKET_TYPE_CHAR_TCP && type != SOCKET_TYPE_CHAR_UDP) {
153 if (iface == 0 || iface > 0xFF) {
163 in->sin_family = AF_INET;
164 in->sin_addr.s_addr = htonl((127<<24) | iface);
165 in->sin_port = htons(prt);
167 *len = sizeof(struct sockaddr_in);
171 static int convert_in_un_remote(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un,
178 unsigned int addr= ntohl(in->sin_addr.s_addr);
179 unsigned int prt = ntohs(in->sin_port);
183 if (bcast) *bcast = 0;
192 u_type = SOCKET_TYPE_CHAR_TCP;
195 u_type = SOCKET_TYPE_CHAR_UDP;
196 a_type = SOCKET_TYPE_CHAR_UDP;
197 b_type = SOCKET_TYPE_CHAR_UDP;
201 if (a_type && addr == 0xFFFFFFFF) {
202 /* 255.255.255.255 only udp */
205 iface = socket_wrapper_default_iface();
206 } else if (b_type && addr == 0x7FFFFFFF) {
207 /* 127.255.255.255 only udp */
210 iface = socket_wrapper_default_iface();
211 } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
215 iface = (addr & 0x000000FF);
221 if (bcast) *bcast = is_bcast;
224 snprintf(un->sun_path, sizeof(un->sun_path), "%s/EINVAL",
225 socket_wrapper_dir());
226 /* the caller need to do more processing */
230 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
231 socket_wrapper_dir(), type, iface, prt);
236 static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un,
244 unsigned int addr= ntohl(in->sin_addr.s_addr);
245 unsigned int prt = ntohs(in->sin_port);
250 if (bcast) *bcast = 0;
254 u_type = SOCKET_TYPE_CHAR_TCP;
255 d_type = SOCKET_TYPE_CHAR_TCP;
258 u_type = SOCKET_TYPE_CHAR_UDP;
259 d_type = SOCKET_TYPE_CHAR_UDP;
260 a_type = SOCKET_TYPE_CHAR_UDP;
261 b_type = SOCKET_TYPE_CHAR_UDP;
269 iface = socket_wrapper_default_iface();
270 } else if (a_type && addr == 0xFFFFFFFF) {
271 /* 255.255.255.255 only udp */
274 iface = socket_wrapper_default_iface();
275 } else if (b_type && addr == 0x7FFFFFFF) {
276 /* 127.255.255.255 only udp */
279 iface = socket_wrapper_default_iface();
280 } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
284 iface = (addr & 0x000000FF);
286 errno = EADDRNOTAVAIL;
290 if (bcast) *bcast = is_bcast;
293 /* handle auto-allocation of ephemeral ports */
294 for (prt = 5001; prt < 10000; prt++) {
295 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
296 socket_wrapper_dir(), type, iface, prt);
297 if (stat(un->sun_path, &st) == 0) continue;
299 ((struct sockaddr_in *)si->myname)->sin_port = htons(prt);
306 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
307 socket_wrapper_dir(), type, iface, prt);
311 static struct socket_info *find_socket_info(int fd)
313 struct socket_info *i;
314 for (i = sockets; i; i = i->next) {
322 static int sockaddr_convert_to_un(struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len,
323 struct sockaddr_un *out_addr, int alloc_sock, int *bcast)
328 out_addr->sun_family = AF_UNIX;
330 switch (in_addr->sa_family) {
337 errno = ESOCKTNOSUPPORT;
341 return convert_in_un_alloc(si, (const struct sockaddr_in *)in_addr, out_addr, bcast);
343 return convert_in_un_remote(si, (const struct sockaddr_in *)in_addr, out_addr, bcast);
346 memcpy(out_addr, in_addr, sizeof(*out_addr));
352 errno = EAFNOSUPPORT;
356 static int sockaddr_convert_from_un(const struct socket_info *si,
357 const struct sockaddr_un *in_addr,
358 socklen_t un_addrlen,
360 struct sockaddr *out_addr,
361 socklen_t *_out_addrlen)
363 socklen_t out_addrlen;
365 if (out_addr == NULL || _out_addrlen == NULL)
368 if (un_addrlen == 0) {
373 out_addrlen = *_out_addrlen;
374 if (out_addrlen > un_addrlen) {
375 out_addrlen = un_addrlen;
385 errno = ESOCKTNOSUPPORT;
388 return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, _out_addrlen);
390 memcpy(out_addr, in_addr, out_addrlen);
391 *_out_addrlen = out_addrlen;
397 errno = EAFNOSUPPORT;
401 _PUBLIC_ int swrap_socket(int domain, int type, int protocol)
403 struct socket_info *si;
406 if (!socket_wrapper_dir()) {
407 return real_socket(domain, type, protocol);
410 fd = real_socket(AF_UNIX, type, 0);
412 if (fd == -1) return -1;
414 si = calloc(1, sizeof(struct socket_info));
418 si->protocol = protocol;
421 DLIST_ADD(sockets, si);
426 _PUBLIC_ int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
428 struct socket_info *parent_si, *child_si;
430 struct sockaddr_un un_addr;
431 socklen_t un_addrlen = sizeof(un_addr);
432 struct sockaddr_un un_my_addr;
433 socklen_t un_my_addrlen = sizeof(un_my_addr);
434 struct sockaddr my_addr;
435 socklen_t my_addrlen = sizeof(my_addr);
438 parent_si = find_socket_info(s);
440 return real_accept(s, addr, addrlen);
443 memset(&un_addr, 0, sizeof(un_addr));
444 memset(&un_my_addr, 0, sizeof(un_my_addr));
445 memset(&my_addr, 0, sizeof(my_addr));
447 ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
448 if (ret == -1) return ret;
452 ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
453 parent_si->domain, addr, addrlen);
454 if (ret == -1) return ret;
456 child_si = malloc(sizeof(struct socket_info));
457 memset(child_si, 0, sizeof(*child_si));
460 child_si->domain = parent_si->domain;
461 child_si->type = parent_si->type;
462 child_si->protocol = parent_si->protocol;
465 ret = real_getsockname(fd, (struct sockaddr *)&un_my_addr, &un_my_addrlen);
466 if (ret == -1) return ret;
468 ret = sockaddr_convert_from_un(child_si, &un_my_addr, un_my_addrlen,
469 child_si->domain, &my_addr, &my_addrlen);
470 if (ret == -1) return ret;
472 child_si->myname_len = my_addrlen;
473 child_si->myname = sockaddr_dup(&my_addr, my_addrlen);
475 child_si->peername_len = *addrlen;
476 child_si->peername = sockaddr_dup(addr, *addrlen);
478 DLIST_ADD(sockets, child_si);
483 /* using sendto() or connect() on an unbound socket would give the
484 recipient no way to reply, as unlike UDP and TCP, a unix domain
485 socket can't auto-assign emphemeral port numbers, so we need to
487 static int swrap_auto_bind(struct socket_info *si)
489 struct sockaddr_un un_addr;
490 struct sockaddr_in in;
496 un_addr.sun_family = AF_UNIX;
500 type = SOCKET_TYPE_CHAR_TCP;
503 type = SOCKET_TYPE_CHAR_UDP;
506 errno = ESOCKTNOSUPPORT;
510 for (i=0;i<1000;i++) {
511 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path),
512 "%s/"SOCKET_FORMAT, socket_wrapper_dir(),
513 type, socket_wrapper_default_iface(), i + 10000);
514 if (stat(un_addr.sun_path, &st) == 0) continue;
516 ret = real_bind(si->fd, (struct sockaddr *)&un_addr, sizeof(un_addr));
517 if (ret == -1) return ret;
519 si->tmp_path = strdup(un_addr.sun_path);
528 memset(&in, 0, sizeof(in));
529 in.sin_family = AF_INET;
530 in.sin_port = htons(i);
531 in.sin_addr.s_addr = htonl(127<<24 | socket_wrapper_default_iface());
533 si->myname_len = sizeof(in);
534 si->myname = sockaddr_dup(&in, si->myname_len);
540 _PUBLIC_ int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
543 struct sockaddr_un un_addr;
544 struct socket_info *si = find_socket_info(s);
547 return real_connect(s, serv_addr, addrlen);
550 if (si->bound == 0 && si->domain != AF_UNIX) {
551 ret = swrap_auto_bind(si);
552 if (ret == -1) return -1;
555 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr, 0, NULL);
556 if (ret == -1) return -1;
558 ret = real_connect(s, (struct sockaddr *)&un_addr,
559 sizeof(struct sockaddr_un));
561 /* to give better errors */
562 if (serv_addr->sa_family == AF_INET) {
563 if (ret == -1 && errno == ENOENT) {
564 errno = EHOSTUNREACH;
569 si->peername_len = addrlen;
570 si->peername = sockaddr_dup(serv_addr, addrlen);
576 _PUBLIC_ int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
579 struct sockaddr_un un_addr;
580 struct socket_info *si = find_socket_info(s);
583 return real_bind(s, myaddr, addrlen);
586 si->myname_len = addrlen;
587 si->myname = sockaddr_dup(myaddr, addrlen);
589 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr, 1, &si->bcast);
590 if (ret == -1) return -1;
592 unlink(un_addr.sun_path);
594 ret = real_bind(s, (struct sockaddr *)&un_addr,
595 sizeof(struct sockaddr_un));
604 _PUBLIC_ int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
606 struct socket_info *si = find_socket_info(s);
609 return real_getpeername(s, name, addrlen);
618 memcpy(name, si->peername, si->peername_len);
619 *addrlen = si->peername_len;
624 _PUBLIC_ int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
626 struct socket_info *si = find_socket_info(s);
629 return real_getsockname(s, name, addrlen);
632 memcpy(name, si->myname, si->myname_len);
633 *addrlen = si->myname_len;
638 _PUBLIC_ int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
640 struct socket_info *si = find_socket_info(s);
643 return real_getsockopt(s, level, optname, optval, optlen);
646 if (level == SOL_SOCKET) {
647 return real_getsockopt(s, level, optname, optval, optlen);
650 switch (si->domain) {
652 return real_getsockopt(s, level, optname, optval, optlen);
659 _PUBLIC_ int swrap_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
661 struct socket_info *si = find_socket_info(s);
664 return real_setsockopt(s, level, optname, optval, optlen);
667 if (level == SOL_SOCKET) {
668 return real_setsockopt(s, level, optname, optval, optlen);
671 switch (si->domain) {
673 return real_setsockopt(s, level, optname, optval, optlen);
682 _PUBLIC_ ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
684 struct sockaddr_un un_addr;
685 socklen_t un_addrlen = sizeof(un_addr);
687 struct socket_info *si = find_socket_info(s);
690 return real_recvfrom(s, buf, len, flags, from, fromlen);
693 /* irix 6.4 forgets to null terminate the sun_path string :-( */
694 memset(&un_addr, 0, sizeof(un_addr));
695 ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
699 if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
700 si->domain, from, fromlen) == -1) {
708 _PUBLIC_ ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
710 struct sockaddr_un un_addr;
712 struct socket_info *si = find_socket_info(s);
716 return real_sendto(s, buf, len, flags, to, tolen);
719 if (si->bound == 0 && si->domain != AF_UNIX) {
720 ret = swrap_auto_bind(si);
721 if (ret == -1) return -1;
724 ret = sockaddr_convert_to_un(si, to, tolen, &un_addr, 0, &bcast);
725 if (ret == -1) return -1;
730 unsigned int prt = ntohs(((const struct sockaddr_in *)to)->sin_port);
733 type = SOCKET_TYPE_CHAR_UDP;
735 for(iface=0; iface <= 0xFF; iface++) {
736 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/"SOCKET_FORMAT,
737 socket_wrapper_dir(), type, iface, prt);
738 if (stat(un_addr.sun_path, &st) != 0) continue;
740 /* ignore the any errors in broadcast sends */
741 real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
746 ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
748 /* to give better errors */
749 if (to->sa_family == AF_INET) {
750 if (ret == -1 && errno == ENOENT) {
751 errno = EHOSTUNREACH;
758 _PUBLIC_ int swrap_close(int fd)
760 struct socket_info *si = find_socket_info(fd);
763 DLIST_REMOVE(sockets, si);
769 unlink(si->tmp_path);
775 return real_close(fd);