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Commit | Line | Data |
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0ad19a3f | 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> |
e51d4895 | 8 | * Dwight Engen <dwight.engen@oracle.com> |
0ad19a3f | 9 | * |
10 | * This library is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU Lesser General Public | |
12 | * License as published by the Free Software Foundation; either | |
13 | * version 2.1 of the License, or (at your option) any later version. | |
14 | * | |
15 | * This library is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | * Lesser General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU Lesser General Public | |
21 | * License along with this library; if not, write to the Free Software | |
250b1eec | 22 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
0ad19a3f | 23 | */ |
e51d4895 | 24 | |
0ad19a3f | 25 | #include <stdio.h> |
26 | #include <errno.h> | |
27 | #include <unistd.h> | |
28 | #include <string.h> | |
29 | #include <stdlib.h> | |
aae93dd3 | 30 | #include <stddef.h> |
0ad19a3f | 31 | #include <fcntl.h> |
b45c7011 DE |
32 | #include <inttypes.h> |
33 | #include <stdint.h> | |
0ad19a3f | 34 | #include <sys/types.h> |
35 | #include <sys/stat.h> | |
36 | #include <sys/param.h> | |
0ad19a3f | 37 | #include <sys/socket.h> |
e51d4895 | 38 | #include <sys/wait.h> |
0ad19a3f | 39 | #include <netinet/in.h> |
40 | #include <net/if.h> | |
2366b8a7 | 41 | #include <poll.h> |
b113348e | 42 | |
e2bcd7db | 43 | #include "error.h" |
31c53c2e | 44 | #include "af_unix.h" |
f2363e38 ÇO |
45 | #include "log.h" |
46 | #include "lxclock.h" | |
47 | #include "state.h" | |
48 | #include "monitor.h" | |
49 | #include "utils.h" | |
36eb9bde CLG |
50 | |
51 | lxc_log_define(lxc_monitor, lxc); | |
0ad19a3f | 52 | |
e51d4895 | 53 | /* routines used by monitor publishers (containers) */ |
9e60f51d DE |
54 | int lxc_monitor_fifo_name(const char *lxcpath, char *fifo_path, size_t fifo_path_sz, |
55 | int do_mkdirp) | |
56 | { | |
57 | int ret; | |
44b9ae4b | 58 | char *rundir; |
9e60f51d DE |
59 | |
60 | rundir = get_rundir(); | |
97a696c6 SG |
61 | if (!rundir) |
62 | return -1; | |
63 | ||
9e60f51d DE |
64 | if (do_mkdirp) { |
65 | ret = snprintf(fifo_path, fifo_path_sz, "%s/lxc/%s", rundir, lxcpath); | |
66 | if (ret < 0 || ret >= fifo_path_sz) { | |
67 | ERROR("rundir/lxcpath (%s/%s) too long for monitor fifo", rundir, lxcpath); | |
44b9ae4b | 68 | free(rundir); |
9e60f51d DE |
69 | return -1; |
70 | } | |
9e60f51d | 71 | ret = mkdir_p(fifo_path, 0755); |
9e60f51d DE |
72 | if (ret < 0) { |
73 | ERROR("unable to create monitor fifo dir %s", fifo_path); | |
44b9ae4b | 74 | free(rundir); |
9e60f51d DE |
75 | return ret; |
76 | } | |
77 | } | |
78 | ret = snprintf(fifo_path, fifo_path_sz, "%s/lxc/%s/monitor-fifo", rundir, lxcpath); | |
79 | if (ret < 0 || ret >= fifo_path_sz) { | |
80 | ERROR("rundir/lxcpath (%s/%s) too long for monitor fifo", rundir, lxcpath); | |
44b9ae4b | 81 | free(rundir); |
9e60f51d DE |
82 | return -1; |
83 | } | |
44b9ae4b | 84 | free(rundir); |
9e60f51d DE |
85 | return 0; |
86 | } | |
87 | ||
e51d4895 | 88 | static void lxc_monitor_fifo_send(struct lxc_msg *msg, const char *lxcpath) |
0ad19a3f | 89 | { |
e51d4895 DE |
90 | int fd,ret; |
91 | char fifo_path[PATH_MAX]; | |
92 | ||
93 | BUILD_BUG_ON(sizeof(*msg) > PIPE_BUF); /* write not guaranteed atomic */ | |
9e60f51d DE |
94 | |
95 | ret = lxc_monitor_fifo_name(lxcpath, fifo_path, sizeof(fifo_path), 0); | |
96 | if (ret < 0) | |
9123e471 | 97 | return; |
80f41298 | 98 | |
8bf1e61e DE |
99 | /* open the fifo nonblock in case the monitor is dead, we don't want |
100 | * the open to wait for a reader since it may never come. | |
101 | */ | |
102 | fd = open(fifo_path, O_WRONLY|O_NONBLOCK); | |
e51d4895 | 103 | if (fd < 0) { |
8bf1e61e DE |
104 | /* it is normal for this open to fail ENXIO when there is no |
105 | * monitor running, so we don't log it | |
e51d4895 | 106 | */ |
31c53c2e | 107 | return; |
e51d4895 | 108 | } |
0ad19a3f | 109 | |
92ffb6d8 DE |
110 | if (fcntl(fd, F_SETFL, O_WRONLY) < 0) { |
111 | close(fd); | |
8bf1e61e | 112 | return; |
92ffb6d8 | 113 | } |
8bf1e61e | 114 | |
e51d4895 DE |
115 | ret = write(fd, msg, sizeof(*msg)); |
116 | if (ret != sizeof(*msg)) { | |
e8b9ac8f | 117 | close(fd); |
e51d4895 DE |
118 | SYSERROR("failed to write monitor fifo %s", fifo_path); |
119 | return; | |
120 | } | |
0ad19a3f | 121 | |
122 | close(fd); | |
123 | } | |
124 | ||
9123e471 | 125 | void lxc_monitor_send_state(const char *name, lxc_state_t state, const char *lxcpath) |
eae6543d | 126 | { |
127 | struct lxc_msg msg = { .type = lxc_msg_state, | |
128 | .value = state }; | |
80f41298 | 129 | strncpy(msg.name, name, sizeof(msg.name)); |
f3bc28bd | 130 | msg.name[sizeof(msg.name) - 1] = 0; |
eae6543d | 131 | |
e51d4895 | 132 | lxc_monitor_fifo_send(&msg, lxcpath); |
0ad19a3f | 133 | } |
134 | ||
1787abca JTLB |
135 | void lxc_monitor_send_exit_code(const char *name, int exit_code, const char *lxcpath) |
136 | { | |
137 | struct lxc_msg msg = { .type = lxc_msg_exit_code, | |
138 | .value = exit_code }; | |
139 | strncpy(msg.name, name, sizeof(msg.name)); | |
140 | msg.name[sizeof(msg.name) - 1] = 0; | |
141 | ||
142 | lxc_monitor_fifo_send(&msg, lxcpath); | |
143 | } | |
144 | ||
e51d4895 DE |
145 | |
146 | /* routines used by monitor subscribers (lxc-monitor) */ | |
147 | int lxc_monitor_close(int fd) | |
0ad19a3f | 148 | { |
dd1d77f9 | 149 | return close(fd); |
e51d4895 DE |
150 | } |
151 | ||
152 | int lxc_monitor_sock_name(const char *lxcpath, struct sockaddr_un *addr) { | |
153 | size_t len; | |
154 | int ret; | |
b45c7011 | 155 | char *sockname = &addr->sun_path[1]; |
073135ba | 156 | char *path; |
b45c7011 | 157 | uint64_t hash; |
e51d4895 | 158 | |
b45c7011 DE |
159 | /* addr.sun_path is only 108 bytes, so we hash the full name and |
160 | * then append as much of the name as we can fit. | |
9123e471 | 161 | */ |
e51d4895 DE |
162 | memset(addr, 0, sizeof(*addr)); |
163 | addr->sun_family = AF_UNIX; | |
073135ba SH |
164 | len = strlen(lxcpath) + 18; |
165 | path = alloca(len); | |
166 | ret = snprintf(path, len, "lxc/%s/monitor-sock", lxcpath); | |
167 | if (ret < 0 || ret >= len) { | |
168 | ERROR("memory error creating monitor path"); | |
9e60f51d DE |
169 | return -1; |
170 | } | |
9e60f51d | 171 | |
073135ba | 172 | len = sizeof(addr->sun_path) - 1; |
b45c7011 DE |
173 | hash = fnv_64a_buf(path, ret, FNV1A_64_INIT); |
174 | ret = snprintf(sockname, len, "lxc/%016" PRIx64 "/%s", hash, lxcpath); | |
175 | if (ret < 0) | |
9123e471 | 176 | return -1; |
073135ba | 177 | sockname[sizeof(addr->sun_path)-3] = '\0'; |
b45c7011 | 178 | INFO("using monitor sock name %s", sockname); |
e51d4895 DE |
179 | return 0; |
180 | } | |
0ad19a3f | 181 | |
e51d4895 DE |
182 | int lxc_monitor_open(const char *lxcpath) |
183 | { | |
184 | struct sockaddr_un addr; | |
f58ad87a | 185 | int fd,ret = 0; |
e51d4895 | 186 | int retry,backoff_ms[] = {10, 50, 100}; |
aae93dd3 | 187 | size_t len; |
e51d4895 DE |
188 | |
189 | if (lxc_monitor_sock_name(lxcpath, &addr) < 0) | |
190 | return -1; | |
191 | ||
192 | fd = socket(PF_UNIX, SOCK_STREAM, 0); | |
2c396e12 MN |
193 | if (fd < 0) { |
194 | ERROR("socket : %s", strerror(errno)); | |
31c53c2e | 195 | return -1; |
2c396e12 | 196 | } |
0ad19a3f | 197 | |
aae93dd3 ÇO |
198 | len = strlen(&addr.sun_path[1]) + 1; |
199 | if (len >= sizeof(addr.sun_path) - 1) { | |
200 | ret = -1; | |
201 | errno = ENAMETOOLONG; | |
202 | goto err1; | |
203 | } | |
204 | ||
e51d4895 | 205 | for (retry = 0; retry < sizeof(backoff_ms)/sizeof(backoff_ms[0]); retry++) { |
aae93dd3 | 206 | ret = connect(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len); |
e51d4895 DE |
207 | if (ret == 0 || errno != ECONNREFUSED) |
208 | break; | |
209 | ERROR("connect : backing off %d", backoff_ms[retry]); | |
210 | usleep(backoff_ms[retry] * 1000); | |
0ad19a3f | 211 | } |
212 | ||
e51d4895 DE |
213 | if (ret < 0) { |
214 | ERROR("connect : %s", strerror(errno)); | |
215 | goto err1; | |
216 | } | |
0ad19a3f | 217 | return fd; |
e51d4895 DE |
218 | err1: |
219 | close(fd); | |
220 | return ret; | |
0ad19a3f | 221 | } |
222 | ||
2366b8a7 | 223 | int lxc_monitor_read_fdset(struct pollfd *fds, nfds_t nfds, struct lxc_msg *msg, |
8d06bd13 | 224 | int timeout) |
0ad19a3f | 225 | { |
2366b8a7 SH |
226 | long i; |
227 | int ret; | |
0ad19a3f | 228 | |
2366b8a7 | 229 | ret = poll(fds, nfds, timeout * 1000); |
8d06bd13 | 230 | if (ret == -1) |
75b1e198 | 231 | return -1; |
8d06bd13 DE |
232 | else if (ret == 0) |
233 | return -2; // timed out | |
234 | ||
235 | /* only read from the first ready fd, the others will remain ready | |
236 | * for when this routine is called again | |
237 | */ | |
238 | for (i = 0; i < nfds; i++) { | |
2366b8a7 SH |
239 | if (fds[i].revents != 0) { |
240 | fds[i].revents = 0; | |
241 | ret = recv(fds[i].fd, msg, sizeof(*msg), 0); | |
8d06bd13 DE |
242 | if (ret <= 0) { |
243 | SYSERROR("client failed to recv (monitord died?) %s", | |
244 | strerror(errno)); | |
245 | return -1; | |
246 | } | |
247 | return ret; | |
248 | } | |
0ad19a3f | 249 | } |
8d06bd13 DE |
250 | SYSERROR("no ready fd found?"); |
251 | return -1; | |
252 | } | |
253 | ||
254 | int lxc_monitor_read_timeout(int fd, struct lxc_msg *msg, int timeout) | |
255 | { | |
2366b8a7 | 256 | struct pollfd fds; |
8d06bd13 | 257 | |
2366b8a7 SH |
258 | fds.fd = fd; |
259 | fds.events = POLLIN | POLLPRI; | |
260 | fds.revents = 0; | |
8d06bd13 | 261 | |
2366b8a7 | 262 | return lxc_monitor_read_fdset(&fds, 1, msg, timeout); |
0ad19a3f | 263 | } |
264 | ||
72d0e1cb SG |
265 | int lxc_monitor_read(int fd, struct lxc_msg *msg) |
266 | { | |
267 | return lxc_monitor_read_timeout(fd, msg, -1); | |
268 | } | |
269 | ||
e51d4895 | 270 | |
45e854dc | 271 | #define LXC_MONITORD_PATH LIBEXECDIR "/lxc/lxc-monitord" |
e51d4895 DE |
272 | |
273 | /* used to spawn a monitord either on startup of a daemon container, or when | |
274 | * lxc-monitor starts | |
275 | */ | |
276 | int lxc_monitord_spawn(const char *lxcpath) | |
0ad19a3f | 277 | { |
e51d4895 DE |
278 | pid_t pid1,pid2; |
279 | int pipefd[2]; | |
280 | char pipefd_str[11]; | |
281 | ||
282 | char * const args[] = { | |
45e854dc | 283 | LXC_MONITORD_PATH, |
e51d4895 DE |
284 | (char *)lxcpath, |
285 | pipefd_str, | |
286 | NULL, | |
287 | }; | |
288 | ||
289 | /* double fork to avoid zombies when monitord exits */ | |
290 | pid1 = fork(); | |
291 | if (pid1 < 0) { | |
292 | SYSERROR("failed to fork"); | |
293 | return -1; | |
294 | } | |
295 | ||
296 | if (pid1) { | |
f2bbe86d DE |
297 | if (waitpid(pid1, NULL, 0) != pid1) |
298 | return -1; | |
e51d4895 DE |
299 | return 0; |
300 | } | |
301 | ||
302 | if (pipe(pipefd) < 0) { | |
303 | SYSERROR("failed to create pipe"); | |
304 | exit(EXIT_FAILURE); | |
305 | } | |
306 | ||
307 | pid2 = fork(); | |
308 | if (pid2 < 0) { | |
309 | SYSERROR("failed to fork"); | |
310 | exit(EXIT_FAILURE); | |
311 | } | |
312 | if (pid2) { | |
313 | char c; | |
314 | /* wait for daemon to create socket */ | |
315 | close(pipefd[1]); | |
316 | /* sync with child, we're ignoring the return from read | |
317 | * because regardless if it works or not, either way we've | |
318 | * synced with the child process. the if-empty-statement | |
319 | * construct is to quiet the warn-unused-result warning. | |
320 | */ | |
8f47bc3f SG |
321 | if (read(pipefd[0], &c, 1)) |
322 | ; | |
e51d4895 DE |
323 | close(pipefd[0]); |
324 | exit(EXIT_SUCCESS); | |
325 | } | |
326 | ||
e51d4895 DE |
327 | if (setsid() < 0) { |
328 | SYSERROR("failed to setsid"); | |
329 | exit(EXIT_FAILURE); | |
330 | } | |
d2cf4c37 | 331 | lxc_check_inherited(NULL, true, pipefd[1]); |
69aeabac TA |
332 | if (null_stdfds() < 0) |
333 | exit(EXIT_FAILURE); | |
e51d4895 DE |
334 | close(pipefd[0]); |
335 | sprintf(pipefd_str, "%d", pipefd[1]); | |
336 | execvp(args[0], args); | |
337 | exit(EXIT_FAILURE); | |
0ad19a3f | 338 | } |