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.
24 #include "system/network.h"
25 #include "system/filesys.h"
27 #include <sys/types.h>
29 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <netinet/tcp.h>
39 #include "dlinklist.h"
41 /* LD_PRELOAD doesn't work yet, so REWRITE_CALLS is all we support
46 #define real_accept accept
47 #define real_connect connect
48 #define real_bind bind
49 #define real_getpeername getpeername
50 #define real_getsockname getsockname
51 #define real_getsockopt getsockopt
52 #define real_setsockopt setsockopt
53 #define real_recvfrom recvfrom
54 #define real_sendto sendto
55 #define real_socket socket
56 #define real_close close
59 static struct sockaddr *sockaddr_dup(const void *data, socklen_t len)
61 struct sockaddr *ret = (struct sockaddr *)malloc(len);
62 memcpy(ret, data, len);
78 struct sockaddr *myname;
81 struct sockaddr *peername;
82 socklen_t peername_len;
84 struct socket_info *prev, *next;
87 static struct socket_info *sockets = NULL;
89 static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len)
95 if ((*len) < sizeof(struct sockaddr_in)) {
99 in->sin_family = AF_INET;
100 in->sin_port = htons(1025); /* Default to 1025 */
101 p = strrchr(un->sun_path, '/');
102 if (p) p++; else p = un->sun_path;
104 if (sscanf(p, "sock_ip_%d_%u", &type, &prt) == 2) {
105 in->sin_port = htons(prt);
107 in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
108 *len = sizeof(struct sockaddr_in);
112 static int convert_in_un(struct socket_info *si, const struct sockaddr_in *in, struct sockaddr_un *un)
115 uint16_t prt = ntohs(in->sin_port);
118 /* handle auto-allocation of ephemeral ports */
121 snprintf(un->sun_path, sizeof(un->sun_path), "%s/sock_ip_%d_%u",
122 getenv("SOCKET_WRAPPER_DIR"), type, ++prt);
123 } while (stat(un->sun_path, &st) == 0 && prt < 10000);
124 ((struct sockaddr_in *)si->myname)->sin_port = htons(prt);
126 snprintf(un->sun_path, sizeof(un->sun_path), "%s/sock_ip_%d_%u",
127 getenv("SOCKET_WRAPPER_DIR"), type, prt);
131 static struct socket_info *find_socket_info(int fd)
133 struct socket_info *i;
134 for (i = sockets; i; i = i->next) {
142 static int sockaddr_convert_to_un(struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len,
143 struct sockaddr_un *out_addr)
148 out_addr->sun_family = AF_UNIX;
150 switch (in_addr->sa_family) {
152 return convert_in_un(si, (const struct sockaddr_in *)in_addr, out_addr);
154 memcpy(out_addr, in_addr, sizeof(*out_addr));
160 errno = EAFNOSUPPORT;
164 static int sockaddr_convert_from_un(const struct socket_info *si,
165 const struct sockaddr_un *in_addr,
166 socklen_t un_addrlen,
168 struct sockaddr *out_addr,
171 if (out_addr == NULL || out_len == NULL)
174 if (un_addrlen == 0) {
181 return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, out_len);
183 memcpy(out_addr, in_addr, sizeof(*in_addr));
184 *out_len = sizeof(*in_addr);
190 errno = EAFNOSUPPORT;
194 int swrap_socket(int domain, int type, int protocol)
196 struct socket_info *si;
199 if (!getenv("SOCKET_WRAPPER_DIR")) {
200 return real_socket(domain, type, protocol);
203 fd = real_socket(AF_UNIX, type, 0);
205 if (fd == -1) return -1;
207 si = calloc(1, sizeof(struct socket_info));
211 si->protocol = protocol;
214 DLIST_ADD(sockets, si);
219 int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
221 struct socket_info *parent_si, *child_si;
223 socklen_t un_addrlen = sizeof(struct sockaddr_un);
224 struct sockaddr_un un_addr;
227 parent_si = find_socket_info(s);
229 return real_accept(s, addr, addrlen);
232 ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
233 if (ret == -1) return ret;
237 ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
238 parent_si->domain, addr, addrlen);
239 if (ret == -1) return ret;
241 child_si = malloc(sizeof(struct socket_info));
242 memset(child_si, 0, sizeof(*child_si));
247 child_si->myname_len = parent_si->myname_len;
248 child_si->myname = sockaddr_dup(parent_si->myname, parent_si->myname_len);
250 child_si->peername_len = *addrlen;
251 child_si->peername = sockaddr_dup(addr, *addrlen);
253 DLIST_ADD(sockets, child_si);
258 /* using sendto() or connect() on an unbound socket would give the
259 recipient no way to reply, as unlike UDP and TCP, a unix domain
260 socket can't auto-assign emphemeral port numbers, so we need to
262 static int swrap_auto_bind(struct socket_info *si)
264 struct sockaddr_un un_addr;
265 struct sockaddr_in in;
268 un_addr.sun_family = AF_UNIX;
270 for (i=0;i<1000;i++) {
271 snprintf(un_addr.sun_path, sizeof(un_addr.sun_path),
272 "%s/sock_ip_%u_%u", getenv("SOCKET_WRAPPER_DIR"),
273 SOCK_DGRAM, i + 10000);
274 if (bind(si->fd, (struct sockaddr *)&un_addr,
275 sizeof(un_addr)) == 0) {
276 si->tmp_path = strdup(un_addr.sun_path);
285 memset(&in, 0, sizeof(in));
286 in.sin_family = AF_INET;
287 in.sin_port = htons(i);
288 in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
290 si->myname_len = sizeof(in);
291 si->myname = sockaddr_dup(&in, si->myname_len);
297 int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
300 struct sockaddr_un un_addr;
301 struct socket_info *si = find_socket_info(s);
304 return real_connect(s, serv_addr, addrlen);
307 /* only allow pseudo loopback connections */
308 if (serv_addr->sa_family == AF_INET &&
309 ((const struct sockaddr_in *)serv_addr)->sin_addr.s_addr !=
310 htonl(INADDR_LOOPBACK)) {
315 if (si->bound == 0 && si->domain != AF_UNIX) {
316 ret = swrap_auto_bind(si);
317 if (ret == -1) return -1;
320 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr);
321 if (ret == -1) return -1;
323 ret = real_connect(s, (struct sockaddr *)&un_addr,
324 sizeof(struct sockaddr_un));
327 si->peername_len = addrlen;
328 si->peername = sockaddr_dup(serv_addr, addrlen);
334 int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
337 struct sockaddr_un un_addr;
338 struct socket_info *si = find_socket_info(s);
341 return real_bind(s, myaddr, addrlen);
344 si->myname_len = addrlen;
345 si->myname = sockaddr_dup(myaddr, addrlen);
347 if (myaddr->sa_family == AF_INET &&
348 ((const struct sockaddr_in *)myaddr)->sin_addr.s_addr == 0) {
349 ((struct sockaddr_in *)si->myname)->sin_addr.s_addr =
350 htonl(INADDR_LOOPBACK);
352 ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr);
353 if (ret == -1) return -1;
355 unlink(un_addr.sun_path);
357 ret = real_bind(s, (struct sockaddr *)&un_addr,
358 sizeof(struct sockaddr_un));
367 int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
369 struct socket_info *si = find_socket_info(s);
372 return real_getpeername(s, name, addrlen);
381 memcpy(name, si->peername, si->peername_len);
382 *addrlen = si->peername_len;
387 int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
389 struct socket_info *si = find_socket_info(s);
392 return real_getsockname(s, name, addrlen);
395 memcpy(name, si->myname, si->myname_len);
396 *addrlen = si->myname_len;
401 int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
403 struct socket_info *si = find_socket_info(s);
406 return real_getsockopt(s, level, optname, optval, optlen);
409 if (level == SOL_SOCKET) {
410 return real_getsockopt(s, level, optname, optval, optlen);
413 switch (si->domain) {
415 return real_getsockopt(s, level, optname, optval, optlen);
422 int swrap_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
424 struct socket_info *si = find_socket_info(s);
427 return real_setsockopt(s, level, optname, optval, optlen);
430 if (level == SOL_SOCKET) {
431 return real_setsockopt(s, level, optname, optval, optlen);
434 switch (si->domain) {
436 return real_setsockopt(s, level, optname, optval, optlen);
438 /* Silence some warnings */
440 if (optname == TCP_NODELAY)
449 ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
451 struct sockaddr_un un_addr;
452 socklen_t un_addrlen = sizeof(un_addr);
454 struct socket_info *si = find_socket_info(s);
457 return real_recvfrom(s, buf, len, flags, from, fromlen);
460 ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
464 if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
465 si->domain, from, fromlen) == -1) {
473 ssize_t swrap_sendto(int s, const void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
475 struct sockaddr_un un_addr;
477 struct socket_info *si = find_socket_info(s);
480 return real_sendto(s, buf, len, flags, to, tolen);
483 if (si->bound == 0 && si->domain != AF_UNIX) {
484 ret = swrap_auto_bind(si);
485 if (ret == -1) return -1;
488 ret = sockaddr_convert_to_un(si, to, tolen, &un_addr);
489 if (ret == -1) return -1;
491 ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));
496 int swrap_close(int fd)
498 struct socket_info *si = find_socket_info(fd);
501 DLIST_REMOVE(sockets, si);
507 unlink(si->tmp_path);
513 return real_close(fd);