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 "%u_%u"
68 static struct sockaddr *sockaddr_dup(const void *data, socklen_t len)
70 struct sockaddr *ret = (struct sockaddr *)malloc(len);
71 memcpy(ret, data, len);
87 struct sockaddr *myname;
90 struct sockaddr *peername;
91 socklen_t peername_len;
93 struct socket_info *prev, *next;
96 static struct socket_info *sockets = NULL;
99 static const char *socket_wrapper_dir(void)
101 const char *s = getenv("SOCKET_WRAPPER_DIR");
105 if (strncmp(s, "./", 2) == 0) {
111 static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len)
117 if ((*len) < sizeof(struct sockaddr_in)) {
121 in->sin_family = AF_INET;
122 in->sin_port = htons(1025); /* Default to 1025 */
123 p = strrchr(un->sun_path, '/');
124 if (p) p++; else p = un->sun_path;
126 if (sscanf(p, SOCKET_FORMAT, &type, &prt) == 2) {
127 in->sin_port = htons(prt);
129 in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
130 *len = sizeof(struct sockaddr_in);
134 static int convert_in_un(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un)
137 uint16_t prt = ntohs(in->sin_port);
140 /* handle auto-allocation of ephemeral ports */
143 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
144 socket_wrapper_dir(), type, ++prt);
145 } while (stat(un->sun_path, &st) == 0 && prt < 10000);
146 ((struct sockaddr_in *)si->myname)->sin_port = htons(prt);
148 snprintf(un->sun_path, sizeof(un->sun_path), "%s/"SOCKET_FORMAT,
149 socket_wrapper_dir(), type, prt);
153 static struct socket_info *find_socket_info(int fd)
155 struct socket_info *i;
156 for (i = sockets; i; i = i->next) {
164 static int sockaddr_convert_to_un(struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len,
165 struct sockaddr_un *out_addr)
170 out_addr->sun_family = AF_UNIX;
172 switch (in_addr->sa_family) {
174 return convert_in_un(si, (const struct sockaddr_in *)in_addr, out_addr);
176 memcpy(out_addr, in_addr, sizeof(*out_addr));
182 errno = EAFNOSUPPORT;
186 static int sockaddr_convert_from_un(const struct socket_info *si,
187 const struct sockaddr_un *in_addr,
188 socklen_t un_addrlen,
190 struct sockaddr *out_addr,
193 if (out_addr == NULL || out_len == NULL)
196 if (un_addrlen == 0) {
203 return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, out_len);
205 memcpy(out_addr, in_addr, sizeof(*in_addr));
206 *out_len = sizeof(*in_addr);
212 errno = EAFNOSUPPORT;
216 int swrap_socket(int domain, int type, int protocol)
218 struct socket_info *si;
221 if (!socket_wrapper_dir()) {
222 return real_socket(domain, type, protocol);
225 fd = real_socket(AF_UNIX, type, 0);
227 if (fd == -1) return -1;
229 si = calloc(1, sizeof(struct socket_info));
233 si->protocol = protocol;
236 DLIST_ADD(sockets, si);
241 int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
243 struct socket_info *parent_si, *child_si;
245 socklen_t un_addrlen = sizeof(struct sockaddr_un);
246 struct sockaddr_un un_addr;
249 parent_si = find_socket_info(s);
251 return real_accept(s, addr, addrlen);
254 memset(&un_addr, 0, sizeof(un_addr));
256 ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
257 if (ret == -1) return ret;
261 ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
262 parent_si->domain, addr, addrlen);
263 if (ret == -1) return ret;
265 child_si = malloc(sizeof(struct socket_info));
266 memset(child_si, 0, sizeof(*child_si));
271 child_si->myname_len = parent_si->myname_len;
272 child_si->myname = sockaddr_dup(parent_si->myname, parent_si->myname_len);
274 child_si->peername_len = *addrlen;
275 child_si->peername = sockaddr_dup(addr, *addrlen);
277 DLIST_ADD(sockets, child_si);
282 /* using sendto() or connect() on an unbound socket would give the
283 recipient no way to reply, as unlike UDP and TCP, a unix domain
284 socket can't auto-assign emphemeral port numbers, so we need to
286 static int swrap_auto_bind(struct socket_info *si)
288 struct sockaddr_un un_addr;
289 struct sockaddr_in in;
292 un_addr.sun_family = AF_UNIX;
294 for (i=0;i<1000;i++) {
295 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path),
296 "%s/"SOCKET_FORMAT, socket_wrapper_dir(),
297 SOCK_DGRAM, i + 10000);
298 if (bind(si->fd, (struct sockaddr *)&un_addr,
299 sizeof(un_addr)) == 0) {
300 si->tmp_path = strdup(un_addr.sun_path);
309 memset(&in, 0, sizeof(in));
310 in.sin_family = AF_INET;
311 in.sin_port = htons(i);
312 in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
314 si->myname_len = sizeof(in);
315 si->myname = sockaddr_dup(&in, si->myname_len);
321 int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
324 struct sockaddr_un un_addr;
325 struct socket_info *si = find_socket_info(s);
328 return real_connect(s, serv_addr, addrlen);
331 /* only allow pseudo loopback connections */
332 if (serv_addr->sa_family == AF_INET &&
333 ((const struct sockaddr_in *)serv_addr)->sin_addr.s_addr !=
334 htonl(INADDR_LOOPBACK)) {
339 if (si->bound == 0 && si->domain != AF_UNIX) {
340 ret = swrap_auto_bind(si);
341 if (ret == -1) return -1;
344 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr);
345 if (ret == -1) return -1;
347 ret = real_connect(s, (struct sockaddr *)&un_addr,
348 sizeof(struct sockaddr_un));
351 si->peername_len = addrlen;
352 si->peername = sockaddr_dup(serv_addr, addrlen);
358 int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
361 struct sockaddr_un un_addr;
362 struct socket_info *si = find_socket_info(s);
365 return real_bind(s, myaddr, addrlen);
368 si->myname_len = addrlen;
369 si->myname = sockaddr_dup(myaddr, addrlen);
371 if (myaddr->sa_family == AF_INET &&
372 ((const struct sockaddr_in *)myaddr)->sin_addr.s_addr == 0) {
373 ((struct sockaddr_in *)si->myname)->sin_addr.s_addr =
374 htonl(INADDR_LOOPBACK);
376 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr);
377 if (ret == -1) return -1;
379 unlink(un_addr.sun_path);
381 ret = real_bind(s, (struct sockaddr *)&un_addr,
382 sizeof(struct sockaddr_un));
391 int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
393 struct socket_info *si = find_socket_info(s);
396 return real_getpeername(s, name, addrlen);
405 memcpy(name, si->peername, si->peername_len);
406 *addrlen = si->peername_len;
411 int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
413 struct socket_info *si = find_socket_info(s);
416 return real_getsockname(s, name, addrlen);
419 memcpy(name, si->myname, si->myname_len);
420 *addrlen = si->myname_len;
425 int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
427 struct socket_info *si = find_socket_info(s);
430 return real_getsockopt(s, level, optname, optval, optlen);
433 if (level == SOL_SOCKET) {
434 return real_getsockopt(s, level, optname, optval, optlen);
437 switch (si->domain) {
439 return real_getsockopt(s, level, optname, optval, optlen);
446 int swrap_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
448 struct socket_info *si = find_socket_info(s);
451 return real_setsockopt(s, level, optname, optval, optlen);
454 if (level == SOL_SOCKET) {
455 return real_setsockopt(s, level, optname, optval, optlen);
458 switch (si->domain) {
460 return real_setsockopt(s, level, optname, optval, optlen);
462 /* Silence some warnings */
464 if (optname == TCP_NODELAY)
473 ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
475 struct sockaddr_un un_addr;
476 socklen_t un_addrlen = sizeof(un_addr);
478 struct socket_info *si = find_socket_info(s);
481 return real_recvfrom(s, buf, len, flags, from, fromlen);
484 /* irix 6.4 forgets to null terminate the sun_path string :-( */
485 memset(&un_addr, 0, sizeof(un_addr));
486 ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
490 if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
491 si->domain, from, fromlen) == -1) {
499 ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
501 struct sockaddr_un un_addr;
503 struct socket_info *si = find_socket_info(s);
506 return real_sendto(s, buf, len, flags, to, tolen);
509 if (si->bound == 0 && si->domain != AF_UNIX) {
510 ret = swrap_auto_bind(si);
511 if (ret == -1) return -1;
514 ret = sockaddr_convert_to_un(si, to, tolen, &un_addr);
515 if (ret == -1) return -1;
517 ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
522 int swrap_close(int fd)
524 struct socket_info *si = find_socket_info(fd);
527 DLIST_REMOVE(sockets, si);
533 unlink(si->tmp_path);
539 return real_close(fd);