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b0a33c1e 1/*
2 * lxc: linux Container library
3 *
4 * (C) Copyright IBM Corp. 2007, 2008
5 *
6 * Authors:
9afe19d6 7 * Daniel Lezcano <daniel.lezcano at free.fr>
b0a33c1e 8 *
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
250b1eec 21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
b0a33c1e 22 */
d06245b8 23
d38dd64a
CB
24#ifndef _GNU_SOURCE
25#define _GNU_SOURCE 1
26#endif
94ac256f
CB
27#include <errno.h>
28#include <fcntl.h>
29#include <stddef.h>
ae467c54
CB
30#include <stdio.h>
31#include <stdlib.h>
b0a33c1e 32#include <string.h>
33#include <unistd.h>
b0a33c1e 34#include <sys/socket.h>
94ac256f 35#include <sys/syscall.h>
b0a33c1e 36#include <sys/un.h>
37
d38dd64a 38#include "config.h"
2dcb28a9 39#include "log.h"
83c11f1d 40#include "memory_utils.h"
d7b58715 41#include "raw_syscalls.h"
0059379f 42#include "utils.h"
2dcb28a9 43
9de31d5a
CB
44#ifndef HAVE_STRLCPY
45#include "include/strlcpy.h"
46#endif
47
ac2cecc4 48lxc_log_define(af_unix, lxc);
b0a33c1e 49
c62fb5e0 50static ssize_t lxc_abstract_unix_set_sockaddr(struct sockaddr_un *addr,
51 const char *path)
b0a33c1e 52{
ddb17f1f 53 size_t len;
b0a33c1e 54
c62fb5e0 55 if (!addr || !path) {
56 errno = EINVAL;
b0a33c1e 57 return -1;
c62fb5e0 58 }
b0a33c1e 59
aae93dd3 60 /* Clear address structure */
c62fb5e0 61 memset(addr, 0, sizeof(*addr));
b0a33c1e 62
c62fb5e0 63 addr->sun_family = AF_UNIX;
aae93dd3 64
caf3beb0 65 len = strlen(&path[1]);
c62fb5e0 66
caf3beb0 67 /* do not enforce \0-termination */
c62fb5e0 68 if (len >= INT_MAX || len >= sizeof(addr->sun_path)) {
aae93dd3
ÇO
69 errno = ENAMETOOLONG;
70 return -1;
ddb17f1f 71 }
9de31d5a
CB
72
73 /* do not enforce \0-termination */
c62fb5e0 74 memcpy(&addr->sun_path[1], &path[1], len);
75 return len;
76}
77
78int lxc_abstract_unix_open(const char *path, int type, int flags)
79{
80 int fd, ret;
81 ssize_t len;
82 struct sockaddr_un addr;
83
84 fd = socket(PF_UNIX, type, 0);
85 if (fd < 0)
86 return -1;
87
88 if (!path)
89 return fd;
90
91 len = lxc_abstract_unix_set_sockaddr(&addr, path);
92 if (len < 0) {
93 int saved_errno = errno;
94 close(fd);
95 errno = saved_errno;
96 return -1;
97 }
b0a33c1e 98
77b0073a
CB
99 ret = bind(fd, (struct sockaddr *)&addr,
100 offsetof(struct sockaddr_un, sun_path) + len + 1);
101 if (ret < 0) {
c62fb5e0 102 int saved_errno = errno;
b0a33c1e 103 close(fd);
c62fb5e0 104 errno = saved_errno;
b0a33c1e 105 return -1;
106 }
ddb17f1f 107
77b0073a
CB
108 if (type == SOCK_STREAM) {
109 ret = listen(fd, 100);
110 if (ret < 0) {
c62fb5e0 111 int saved_errno = errno;
77b0073a 112 close(fd);
c62fb5e0 113 errno = saved_errno;
77b0073a
CB
114 return -1;
115 }
b0a33c1e 116 }
117
118 return fd;
119}
120
9044b79e 121void lxc_abstract_unix_close(int fd)
b0a33c1e 122{
b0a33c1e 123 close(fd);
b0a33c1e 124}
125
aae93dd3 126int lxc_abstract_unix_connect(const char *path)
b0a33c1e 127{
77b0073a 128 int fd, ret;
c62fb5e0 129 ssize_t len;
b0a33c1e 130 struct sockaddr_un addr;
131
132 fd = socket(PF_UNIX, SOCK_STREAM, 0);
133 if (fd < 0)
134 return -1;
135
c62fb5e0 136 len = lxc_abstract_unix_set_sockaddr(&addr, path);
137 if (len < 0) {
138 int saved_errno = errno;
aae93dd3 139 close(fd);
c62fb5e0 140 errno = saved_errno;
aae93dd3
ÇO
141 return -1;
142 }
9de31d5a 143
77b0073a
CB
144 ret = connect(fd, (struct sockaddr *)&addr,
145 offsetof(struct sockaddr_un, sun_path) + len + 1);
146 if (ret < 0) {
9044b79e 147 int saved_errno = errno;
b0a33c1e 148 close(fd);
9044b79e 149 errno = saved_errno;
b0a33c1e 150 return -1;
151 }
152
153 return fd;
154}
155
ae467c54
CB
156int lxc_abstract_unix_send_fds(int fd, int *sendfds, int num_sendfds,
157 void *data, size_t size)
b0a33c1e 158{
c3e3c21a
CB
159 __do_free char *cmsgbuf = NULL;
160 int ret;
ae467c54 161 struct msghdr msg;
604f0955 162 struct iovec iov;
ae467c54 163 struct cmsghdr *cmsg = NULL;
caf3beb0 164 char buf[1] = {0};
ae467c54
CB
165 size_t cmsgbufsize = CMSG_SPACE(num_sendfds * sizeof(int));
166
167 memset(&msg, 0, sizeof(msg));
168 memset(&iov, 0, sizeof(iov));
169
170 cmsgbuf = malloc(cmsgbufsize);
9044b79e 171 if (!cmsgbuf) {
172 errno = ENOMEM;
ae467c54 173 return -1;
9044b79e 174 }
b0a33c1e 175
604f0955 176 msg.msg_control = cmsgbuf;
ae467c54 177 msg.msg_controllen = cmsgbufsize;
b0a33c1e 178
604f0955 179 cmsg = CMSG_FIRSTHDR(&msg);
604f0955
ÇO
180 cmsg->cmsg_level = SOL_SOCKET;
181 cmsg->cmsg_type = SCM_RIGHTS;
ae467c54 182 cmsg->cmsg_len = CMSG_LEN(num_sendfds * sizeof(int));
b0a33c1e 183
ae467c54
CB
184 msg.msg_controllen = cmsg->cmsg_len;
185
186 memcpy(CMSG_DATA(cmsg), sendfds, num_sendfds * sizeof(int));
b0a33c1e 187
604f0955
ÇO
188 iov.iov_base = data ? data : buf;
189 iov.iov_len = data ? size : sizeof(buf);
190 msg.msg_iov = &iov;
191 msg.msg_iovlen = 1;
b0a33c1e 192
c3e3c21a
CB
193again:
194 ret = sendmsg(fd, &msg, MSG_NOSIGNAL);
195 if (ret < 0)
196 if (errno == EINTR)
197 goto again;
198
199 return ret;
b0a33c1e 200}
201
ae467c54
CB
202int lxc_abstract_unix_recv_fds(int fd, int *recvfds, int num_recvfds,
203 void *data, size_t size)
b0a33c1e 204{
c3e3c21a 205 __do_free char *cmsgbuf = NULL;
ae467c54
CB
206 int ret;
207 struct msghdr msg;
604f0955 208 struct iovec iov;
ae467c54 209 struct cmsghdr *cmsg = NULL;
caf3beb0 210 char buf[1] = {0};
cdb2a47f
CB
211 size_t cmsgbufsize = CMSG_SPACE(sizeof(struct ucred)) +
212 CMSG_SPACE(num_recvfds * sizeof(int));
ae467c54
CB
213
214 memset(&msg, 0, sizeof(msg));
215 memset(&iov, 0, sizeof(iov));
216
217 cmsgbuf = malloc(cmsgbufsize);
9044b79e 218 if (!cmsgbuf) {
219 errno = ENOMEM;
ae467c54 220 return -1;
9044b79e 221 }
b0a33c1e 222
604f0955 223 msg.msg_control = cmsgbuf;
ae467c54 224 msg.msg_controllen = cmsgbufsize;
b0a33c1e 225
604f0955
ÇO
226 iov.iov_base = data ? data : buf;
227 iov.iov_len = data ? size : sizeof(buf);
228 msg.msg_iov = &iov;
229 msg.msg_iovlen = 1;
b0a33c1e 230
c3e3c21a 231again:
b0a33c1e 232 ret = recvmsg(fd, &msg, 0);
c3e3c21a
CB
233 if (ret < 0) {
234 if (errno == EINTR)
235 goto again;
236
237 goto out;
238 }
239 if (ret == 0)
b0a33c1e 240 goto out;
241
cdb2a47f
CB
242 /*
243 * If SO_PASSCRED is set we will always get a ucred message.
244 */
245 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
246 if (cmsg->cmsg_type != SCM_RIGHTS)
247 continue;
248
249 memset(recvfds, -1, num_recvfds * sizeof(int));
250 if (cmsg &&
251 cmsg->cmsg_len == CMSG_LEN(num_recvfds * sizeof(int)) &&
252 cmsg->cmsg_level == SOL_SOCKET)
253 memcpy(recvfds, CMSG_DATA(cmsg), num_recvfds * sizeof(int));
254 break;
255 }
ae467c54 256
b0a33c1e 257out:
604f0955 258 return ret;
b0a33c1e 259}
260
aae93dd3 261int lxc_abstract_unix_send_credential(int fd, void *data, size_t size)
b0a33c1e 262{
77b0073a 263 struct msghdr msg = {0};
604f0955
ÇO
264 struct iovec iov;
265 struct cmsghdr *cmsg;
b0a33c1e 266 struct ucred cred = {
0059379f 267 .pid = lxc_raw_getpid(), .uid = getuid(), .gid = getgid(),
b0a33c1e 268 };
caf3beb0
CB
269 char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
270 char buf[1] = {0};
b0a33c1e 271
604f0955
ÇO
272 msg.msg_control = cmsgbuf;
273 msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e 274
604f0955
ÇO
275 cmsg = CMSG_FIRSTHDR(&msg);
276 cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
277 cmsg->cmsg_level = SOL_SOCKET;
278 cmsg->cmsg_type = SCM_CREDENTIALS;
0e391e57 279 memcpy(CMSG_DATA(cmsg), &cred, sizeof(cred));
b0a33c1e 280
604f0955
ÇO
281 msg.msg_name = NULL;
282 msg.msg_namelen = 0;
b0a33c1e 283
604f0955
ÇO
284 iov.iov_base = data ? data : buf;
285 iov.iov_len = data ? size : sizeof(buf);
286 msg.msg_iov = &iov;
287 msg.msg_iovlen = 1;
b0a33c1e 288
6168ff15 289 return sendmsg(fd, &msg, MSG_NOSIGNAL);
b0a33c1e 290}
291
aae93dd3 292int lxc_abstract_unix_rcv_credential(int fd, void *data, size_t size)
b0a33c1e 293{
77b0073a 294 struct msghdr msg = {0};
604f0955
ÇO
295 struct iovec iov;
296 struct cmsghdr *cmsg;
b0a33c1e 297 struct ucred cred;
b0a33c1e 298 int ret;
caf3beb0
CB
299 char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
300 char buf[1] = {0};
b0a33c1e 301
604f0955
ÇO
302 msg.msg_name = NULL;
303 msg.msg_namelen = 0;
304 msg.msg_control = cmsgbuf;
305 msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e 306
604f0955
ÇO
307 iov.iov_base = data ? data : buf;
308 iov.iov_len = data ? size : sizeof(buf);
309 msg.msg_iov = &iov;
310 msg.msg_iovlen = 1;
b0a33c1e 311
312 ret = recvmsg(fd, &msg, 0);
313 if (ret <= 0)
314 goto out;
315
604f0955 316 cmsg = CMSG_FIRSTHDR(&msg);
b0a33c1e 317
604f0955 318 if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
77b0073a
CB
319 cmsg->cmsg_level == SOL_SOCKET &&
320 cmsg->cmsg_type == SCM_CREDENTIALS) {
0e391e57 321 memcpy(&cred, CMSG_DATA(cmsg), sizeof(cred));
77b0073a
CB
322 if (cred.uid &&
323 (cred.uid != getuid() || cred.gid != getgid())) {
9044b79e 324 INFO("Message denied for '%d/%d'", cred.uid, cred.gid);
325 errno = EACCES;
326 return -1;
2dcb28a9 327 }
604f0955 328 }
9044b79e 329
b0a33c1e 330out:
604f0955 331 return ret;
b0a33c1e 332}
86ce1da1
CB
333
334int lxc_unix_sockaddr(struct sockaddr_un *ret, const char *path)
335{
336 size_t len;
337
338 len = strlen(path);
339 if (len == 0)
340 return minus_one_set_errno(EINVAL);
341 if (path[0] != '/' && path[0] != '@')
342 return minus_one_set_errno(EINVAL);
343 if (path[1] == '\0')
344 return minus_one_set_errno(EINVAL);
345
346 if (len + 1 > sizeof(ret->sun_path))
347 return minus_one_set_errno(EINVAL);
348
349 *ret = (struct sockaddr_un){
350 .sun_family = AF_UNIX,
351 };
352
353 if (path[0] == '@') {
354 memcpy(ret->sun_path + 1, path + 1, len);
355 return (int)(offsetof(struct sockaddr_un, sun_path) + len);
356 }
357
358 memcpy(ret->sun_path, path, len + 1);
359 return (int)(offsetof(struct sockaddr_un, sun_path) + len + 1);
360}
361
362int lxc_unix_connect(struct sockaddr_un *addr)
363{
364 __do_close_prot_errno int fd = -EBADF;
365 int ret;
366 ssize_t len;
367
2ac0f627
CB
368 fd = socket(AF_UNIX, SOCK_STREAM, 0);
369 if (fd < 0) {
370 SYSERROR("Failed to open new AF_UNIX socket");
86ce1da1 371 return -1;
2ac0f627 372 }
86ce1da1
CB
373
374 if (addr->sun_path[0] == '\0')
375 len = strlen(&addr->sun_path[1]);
376 else
377 len = strlen(&addr->sun_path[0]);
2ac0f627
CB
378
379 ret = connect(fd, (struct sockaddr *)addr,
380 offsetof(struct sockaddr_un, sun_path) + len);
381 if (ret < 0) {
382 SYSERROR("Failed to bind new AF_UNIX socket");
86ce1da1 383 return -1;
2ac0f627 384 }
86ce1da1
CB
385
386 return move_fd(fd);
387}
388
389int lxc_socket_set_timeout(int fd, int rcv_timeout, int snd_timeout)
390{
391 struct timeval out = {0};
392 int ret;
393
394 out.tv_sec = snd_timeout;
395 ret = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, (const void *)&out,
396 sizeof(out));
397 if (ret < 0)
398 return -1;
399
400 out.tv_sec = rcv_timeout;
401 ret = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (const void *)&out,
402 sizeof(out));
403 if (ret < 0)
404 return -1;
405
406 return 0;
407}