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
6 Copyright (C) Stefan Metzmacher 2006
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 #include "system/network.h"
27 #include "system/filesys.h"
29 #include <sys/types.h>
31 #include <sys/socket.h>
34 #include <netinet/in.h>
35 #include <netinet/tcp.h>
41 #include "lib/util/dlinklist.h"
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_recv recv
58 #define real_send send
59 #define real_socket socket
60 #define real_close close
63 /* we need to use a very terse format here as IRIX 6.4 silently
64 truncates names to 16 chars, so if we use a longer name then we
65 can't tell which port a packet came from with recvfrom()
67 with this format we have 8 chars left for the directory name
69 #define SOCKET_FORMAT "%c%02X%04X"
70 #define SOCKET_TYPE_CHAR_TCP 'T'
71 #define SOCKET_TYPE_CHAR_UDP 'U'
73 static struct sockaddr *sockaddr_dup(const void *data, socklen_t len)
75 struct sockaddr *ret = (struct sockaddr *)malloc(len);
76 memcpy(ret, data, len);
93 struct sockaddr *myname;
96 struct sockaddr *peername;
97 socklen_t peername_len;
99 struct socket_info *prev, *next;
102 static struct socket_info *sockets;
105 static const char *socket_wrapper_dir(void)
107 const char *s = getenv("SOCKET_WRAPPER_DIR");
111 if (strncmp(s, "./", 2) == 0) {
117 static const char *socket_wrapper_dump_dir(void)
119 const char *s = getenv("SOCKET_WRAPPER_DUMP_DIR");
121 if (!socket_wrapper_dir()) {
128 if (strncmp(s, "./", 2) == 0) {
134 static unsigned int socket_wrapper_default_iface(void)
136 const char *s = getenv("SOCKET_WRAPPER_DEFAULT_IFACE");
139 if (sscanf(s, "%u", &iface) == 1) {
140 if (iface >= 1 && iface <= 0xFF) {
146 return 1;/* 127.0.0.1 */
149 static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len)
156 if ((*len) < sizeof(struct sockaddr_in)) {
160 p = strrchr(un->sun_path, '/');
161 if (p) p++; else p = un->sun_path;
163 if (sscanf(p, SOCKET_FORMAT, &type, &iface, &prt) != 3) {
168 if (type != SOCKET_TYPE_CHAR_TCP && type != SOCKET_TYPE_CHAR_UDP) {
173 if (iface == 0 || iface > 0xFF) {
183 in->sin_family = AF_INET;
184 in->sin_addr.s_addr = htonl((127<<24) | iface);
185 in->sin_port = htons(prt);
187 *len = sizeof(struct sockaddr_in);
191 static int convert_in_un_remote(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un,
198 unsigned int addr= ntohl(in->sin_addr.s_addr);
199 unsigned int prt = ntohs(in->sin_port);
203 if (bcast) *bcast = 0;
212 u_type = SOCKET_TYPE_CHAR_TCP;
215 u_type = SOCKET_TYPE_CHAR_UDP;
216 a_type = SOCKET_TYPE_CHAR_UDP;
217 b_type = SOCKET_TYPE_CHAR_UDP;
221 if (a_type && addr == 0xFFFFFFFF) {
222 /* 255.255.255.255 only udp */
225 iface = socket_wrapper_default_iface();
226 } else if (b_type && addr == 0x7FFFFFFF) {
227 /* 127.255.255.255 only udp */
230 iface = socket_wrapper_default_iface();
231 } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
235 iface = (addr & 0x000000FF);
241 if (bcast) *bcast = is_bcast;
244 snprintf(un->sun_path, sizeof(un->sun_path), "%s/EINVAL",
245 socket_wrapper_dir());
246 /* the caller need to do more processing */
250 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
251 socket_wrapper_dir(), type, iface, prt);
256 static int convert_in_un_alloc(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un,
264 unsigned int addr= ntohl(in->sin_addr.s_addr);
265 unsigned int prt = ntohs(in->sin_port);
270 if (bcast) *bcast = 0;
274 u_type = SOCKET_TYPE_CHAR_TCP;
275 d_type = SOCKET_TYPE_CHAR_TCP;
278 u_type = SOCKET_TYPE_CHAR_UDP;
279 d_type = SOCKET_TYPE_CHAR_UDP;
280 a_type = SOCKET_TYPE_CHAR_UDP;
281 b_type = SOCKET_TYPE_CHAR_UDP;
289 iface = socket_wrapper_default_iface();
290 } else if (a_type && addr == 0xFFFFFFFF) {
291 /* 255.255.255.255 only udp */
294 iface = socket_wrapper_default_iface();
295 } else if (b_type && addr == 0x7FFFFFFF) {
296 /* 127.255.255.255 only udp */
299 iface = socket_wrapper_default_iface();
300 } else if ((addr & 0xFFFFFF00) == 0x7F000000) {
304 iface = (addr & 0x000000FF);
306 errno = EADDRNOTAVAIL;
310 if (bcast) *bcast = is_bcast;
313 /* handle auto-allocation of ephemeral ports */
314 for (prt = 5001; prt < 10000; prt++) {
315 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
316 socket_wrapper_dir(), type, iface, prt);
317 if (stat(un->sun_path, &st) == 0) continue;
319 ((struct sockaddr_in *)si->myname)->sin_port = htons(prt);
326 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
327 socket_wrapper_dir(), type, iface, prt);
331 static struct socket_info *find_socket_info(int fd)
333 struct socket_info *i;
334 for (i = sockets; i; i = i->next) {
342 static int sockaddr_convert_to_un(struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len,
343 struct sockaddr_un *out_addr, int alloc_sock, int *bcast)
348 out_addr->sun_family = AF_UNIX;
350 switch (in_addr->sa_family) {
357 errno = ESOCKTNOSUPPORT;
361 return convert_in_un_alloc(si, (const struct sockaddr_in *)in_addr, out_addr, bcast);
363 return convert_in_un_remote(si, (const struct sockaddr_in *)in_addr, out_addr, bcast);
369 errno = EAFNOSUPPORT;
373 static int sockaddr_convert_from_un(const struct socket_info *si,
374 const struct sockaddr_un *in_addr,
375 socklen_t un_addrlen,
377 struct sockaddr *out_addr,
378 socklen_t *_out_addrlen)
380 socklen_t out_addrlen;
382 if (out_addr == NULL || _out_addrlen == NULL)
385 if (un_addrlen == 0) {
390 out_addrlen = *_out_addrlen;
391 if (out_addrlen > un_addrlen) {
392 out_addrlen = un_addrlen;
402 errno = ESOCKTNOSUPPORT;
405 return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, _out_addrlen);
410 errno = EAFNOSUPPORT;
414 enum swrap_packet_type {
424 static void swrap_dump_packet(struct socket_info *si, const struct sockaddr *addr,
425 enum swrap_packet_type type,
426 const void *buf, size_t len, ssize_t ret)
428 if (!socket_wrapper_dump_dir()) {
434 _PUBLIC_ int swrap_socket(int family, int type, int protocol)
436 struct socket_info *si;
439 if (!socket_wrapper_dir()) {
440 return real_socket(family, type, protocol);
447 return real_socket(family, type, protocol);
449 errno = EAFNOSUPPORT;
453 fd = real_socket(AF_UNIX, type, 0);
455 if (fd == -1) return -1;
457 si = calloc(1, sizeof(struct socket_info));
461 si->protocol = protocol;
464 DLIST_ADD(sockets, si);
469 _PUBLIC_ int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
471 struct socket_info *parent_si, *child_si;
473 struct sockaddr_un un_addr;
474 socklen_t un_addrlen = sizeof(un_addr);
475 struct sockaddr_un un_my_addr;
476 socklen_t un_my_addrlen = sizeof(un_my_addr);
477 struct sockaddr my_addr;
478 socklen_t my_addrlen = sizeof(my_addr);
481 parent_si = find_socket_info(s);
483 return real_accept(s, addr, addrlen);
486 memset(&un_addr, 0, sizeof(un_addr));
487 memset(&un_my_addr, 0, sizeof(un_my_addr));
488 memset(&my_addr, 0, sizeof(my_addr));
490 ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
491 if (ret == -1) return ret;
495 ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
496 parent_si->family, addr, addrlen);
497 if (ret == -1) return ret;
499 child_si = malloc(sizeof(struct socket_info));
500 memset(child_si, 0, sizeof(*child_si));
503 child_si->family = parent_si->family;
504 child_si->type = parent_si->type;
505 child_si->protocol = parent_si->protocol;
508 ret = real_getsockname(fd, (struct sockaddr *)&un_my_addr, &un_my_addrlen);
509 if (ret == -1) return ret;
511 ret = sockaddr_convert_from_un(child_si, &un_my_addr, un_my_addrlen,
512 child_si->family, &my_addr, &my_addrlen);
513 if (ret == -1) return ret;
515 child_si->myname_len = my_addrlen;
516 child_si->myname = sockaddr_dup(&my_addr, my_addrlen);
518 child_si->peername_len = *addrlen;
519 child_si->peername = sockaddr_dup(addr, *addrlen);
521 DLIST_ADD(sockets, child_si);
523 swrap_dump_packet(child_si, addr, SWRAP_ACCEPT, NULL, 0, 0);
528 /* using sendto() or connect() on an unbound socket would give the
529 recipient no way to reply, as unlike UDP and TCP, a unix domain
530 socket can't auto-assign emphemeral port numbers, so we need to
532 static int swrap_auto_bind(struct socket_info *si)
534 struct sockaddr_un un_addr;
535 struct sockaddr_in in;
542 un_addr.sun_family = AF_UNIX;
546 type = SOCKET_TYPE_CHAR_TCP;
549 type = SOCKET_TYPE_CHAR_UDP;
552 errno = ESOCKTNOSUPPORT;
556 for (i=0;i<1000;i++) {
558 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path),
559 "%s/"SOCKET_FORMAT, socket_wrapper_dir(),
560 type, socket_wrapper_default_iface(), port);
561 if (stat(un_addr.sun_path, &st) == 0) continue;
563 ret = real_bind(si->fd, (struct sockaddr *)&un_addr, sizeof(un_addr));
564 if (ret == -1) return ret;
566 si->tmp_path = strdup(un_addr.sun_path);
575 memset(&in, 0, sizeof(in));
576 in.sin_family = AF_INET;
577 in.sin_port = htons(port);
578 in.sin_addr.s_addr = htonl(127<<24 | socket_wrapper_default_iface());
580 si->myname_len = sizeof(in);
581 si->myname = sockaddr_dup(&in, si->myname_len);
587 _PUBLIC_ int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
590 struct sockaddr_un un_addr;
591 struct socket_info *si = find_socket_info(s);
594 return real_connect(s, serv_addr, addrlen);
597 if (si->bound == 0) {
598 ret = swrap_auto_bind(si);
599 if (ret == -1) return -1;
602 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr, 0, NULL);
603 if (ret == -1) return -1;
605 ret = real_connect(s, (struct sockaddr *)&un_addr,
606 sizeof(struct sockaddr_un));
608 /* to give better errors */
609 if (ret == -1 && errno == ENOENT) {
610 errno = EHOSTUNREACH;
614 si->peername_len = addrlen;
615 si->peername = sockaddr_dup(serv_addr, addrlen);
618 swrap_dump_packet(si, serv_addr, SWRAP_CONNECT, NULL, 0, ret);
623 _PUBLIC_ int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
626 struct sockaddr_un un_addr;
627 struct socket_info *si = find_socket_info(s);
630 return real_bind(s, myaddr, addrlen);
633 si->myname_len = addrlen;
634 si->myname = sockaddr_dup(myaddr, addrlen);
636 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr, 1, &si->bcast);
637 if (ret == -1) return -1;
639 unlink(un_addr.sun_path);
641 ret = real_bind(s, (struct sockaddr *)&un_addr,
642 sizeof(struct sockaddr_un));
651 _PUBLIC_ int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
653 struct socket_info *si = find_socket_info(s);
656 return real_getpeername(s, name, addrlen);
665 memcpy(name, si->peername, si->peername_len);
666 *addrlen = si->peername_len;
671 _PUBLIC_ int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
673 struct socket_info *si = find_socket_info(s);
676 return real_getsockname(s, name, addrlen);
679 memcpy(name, si->myname, si->myname_len);
680 *addrlen = si->myname_len;
685 _PUBLIC_ int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
687 struct socket_info *si = find_socket_info(s);
690 return real_getsockopt(s, level, optname, optval, optlen);
693 if (level == SOL_SOCKET) {
694 return real_getsockopt(s, level, optname, optval, optlen);
701 _PUBLIC_ int swrap_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
703 struct socket_info *si = find_socket_info(s);
706 return real_setsockopt(s, level, optname, optval, optlen);
709 if (level == SOL_SOCKET) {
710 return real_setsockopt(s, level, optname, optval, optlen);
713 switch (si->family) {
722 _PUBLIC_ ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
724 struct sockaddr_un un_addr;
725 socklen_t un_addrlen = sizeof(un_addr);
727 struct socket_info *si = find_socket_info(s);
730 return real_recvfrom(s, buf, len, flags, from, fromlen);
733 /* irix 6.4 forgets to null terminate the sun_path string :-( */
734 memset(&un_addr, 0, sizeof(un_addr));
735 ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
739 if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
740 si->family, from, fromlen) == -1) {
744 swrap_dump_packet(si, from, SWRAP_RECVFROM, buf, len, ret);
750 _PUBLIC_ ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
752 struct sockaddr_un un_addr;
754 struct socket_info *si = find_socket_info(s);
758 return real_sendto(s, buf, len, flags, to, tolen);
761 if (si->bound == 0) {
762 ret = swrap_auto_bind(si);
763 if (ret == -1) return -1;
766 ret = sockaddr_convert_to_un(si, to, tolen, &un_addr, 0, &bcast);
767 if (ret == -1) return -1;
772 unsigned int prt = ntohs(((const struct sockaddr_in *)to)->sin_port);
775 type = SOCKET_TYPE_CHAR_UDP;
777 for(iface=0; iface <= 0xFF; iface++) {
778 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), "%s/"SOCKET_FORMAT,
779 socket_wrapper_dir(), type, iface, prt);
780 if (stat(un_addr.sun_path, &st) != 0) continue;
782 /* ignore the any errors in broadcast sends */
783 real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
786 swrap_dump_packet(si, to, SWRAP_SENDTO, buf, len, len);
791 ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
793 /* to give better errors */
794 if (ret == -1 && errno == ENOENT) {
795 errno = EHOSTUNREACH;
798 swrap_dump_packet(si, to, SWRAP_SENDTO, buf, len, ret);
803 _PUBLIC_ ssize_t swrap_recv(int s, void *buf, size_t len, int flags)
806 struct socket_info *si = find_socket_info(s);
809 return real_recv(s, buf, len, flags);
812 ret = real_recv(s, buf, len, flags);
816 swrap_dump_packet(si, NULL, SWRAP_RECV, buf, len, ret);
822 _PUBLIC_ ssize_t swrap_send(int s, const void *buf, size_t len, int flags)
825 struct socket_info *si = find_socket_info(s);
828 return real_send(s, buf, len, flags);
831 ret = real_send(s, buf, len, flags);
835 swrap_dump_packet(si, NULL, SWRAP_SEND, buf, len, ret);
840 _PUBLIC_ int swrap_close(int fd)
842 struct socket_info *si = find_socket_info(fd);
845 DLIST_REMOVE(sockets, si);
847 swrap_dump_packet(si, NULL, SWRAP_CLOSE, NULL, 0, 0);
853 unlink(si->tmp_path);
859 return real_close(fd);