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2ca0435b ZJS |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2013 Zbigniew Jędrzejewski-Szmek | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
3f6fd1ba | 22 | #include <getopt.h> |
2ca0435b ZJS |
23 | #include <sys/epoll.h> |
24 | #include <sys/prctl.h> | |
25 | #include <sys/socket.h> | |
26 | #include <sys/wait.h> | |
3f6fd1ba | 27 | #include <unistd.h> |
2ca0435b | 28 | |
8dd4c05b | 29 | #include "sd-daemon.h" |
2ca0435b | 30 | |
2ca0435b | 31 | #include "log.h" |
2ca0435b | 32 | #include "macro.h" |
ce30c8dc | 33 | #include "signal-util.h" |
3f6fd1ba | 34 | #include "socket-util.h" |
07630cea | 35 | #include "string-util.h" |
3f6fd1ba | 36 | #include "strv.h" |
3ffd4af2 | 37 | #include "fd-util.h" |
2ca0435b ZJS |
38 | |
39 | static char** arg_listen = NULL; | |
40 | static bool arg_accept = false; | |
41 | static char** arg_args = NULL; | |
892213bf | 42 | static char** arg_setenv = NULL; |
8dd4c05b | 43 | static const char *arg_fdname = NULL; |
2ca0435b ZJS |
44 | |
45 | static int add_epoll(int epoll_fd, int fd) { | |
30374ebe LP |
46 | struct epoll_event ev = { |
47 | .events = EPOLLIN | |
48 | }; | |
2ca0435b | 49 | int r; |
2ca0435b ZJS |
50 | |
51 | assert(epoll_fd >= 0); | |
52 | assert(fd >= 0); | |
53 | ||
30374ebe | 54 | ev.data.fd = fd; |
2ca0435b | 55 | r = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev); |
4a62c710 MS |
56 | if (r < 0) |
57 | return log_error_errno(errno, "Failed to add event on epoll fd:%d for fd:%d: %m", epoll_fd, fd); | |
603938e0 LP |
58 | |
59 | return 0; | |
2ca0435b ZJS |
60 | } |
61 | ||
62 | static int open_sockets(int *epoll_fd, bool accept) { | |
30374ebe | 63 | char **address; |
29a5ca9b | 64 | int n, fd, r; |
2ca0435b | 65 | int count = 0; |
2ca0435b ZJS |
66 | |
67 | n = sd_listen_fds(true); | |
eb56eb9b MS |
68 | if (n < 0) |
69 | return log_error_errno(n, "Failed to read listening file descriptors from environment: %m"); | |
30374ebe LP |
70 | if (n > 0) { |
71 | log_info("Received %i descriptors via the environment.", n); | |
2ca0435b | 72 | |
30374ebe LP |
73 | for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++) { |
74 | r = fd_cloexec(fd, arg_accept); | |
75 | if (r < 0) | |
76 | return r; | |
2ca0435b | 77 | |
30374ebe LP |
78 | count ++; |
79 | } | |
2ca0435b ZJS |
80 | } |
81 | ||
c0997164 ZJS |
82 | /* Close logging and all other descriptors */ |
83 | if (arg_listen) { | |
84 | int except[3 + n]; | |
85 | ||
86 | for (fd = 0; fd < SD_LISTEN_FDS_START + n; fd++) | |
87 | except[fd] = fd; | |
88 | ||
89 | log_close(); | |
90 | close_all_fds(except, 3 + n); | |
91 | } | |
92 | ||
fff40a51 ZJS |
93 | /** Note: we leak some fd's on error here. I doesn't matter |
94 | * much, since the program will exit immediately anyway, but | |
95 | * would be a pain to fix. | |
96 | */ | |
97 | ||
2ca0435b | 98 | STRV_FOREACH(address, arg_listen) { |
2ca0435b | 99 | |
e0aa3726 | 100 | fd = make_socket_fd(LOG_DEBUG, *address, SOCK_STREAM | (arg_accept*SOCK_CLOEXEC)); |
2ca0435b | 101 | if (fd < 0) { |
c0997164 | 102 | log_open(); |
23bbb0de | 103 | return log_error_errno(fd, "Failed to open '%s': %m", *address); |
2ca0435b ZJS |
104 | } |
105 | ||
175a3d25 | 106 | assert(fd == SD_LISTEN_FDS_START + count); |
2ca0435b ZJS |
107 | count ++; |
108 | } | |
109 | ||
c0997164 ZJS |
110 | if (arg_listen) |
111 | log_open(); | |
112 | ||
2ca0435b | 113 | *epoll_fd = epoll_create1(EPOLL_CLOEXEC); |
4a62c710 MS |
114 | if (*epoll_fd < 0) |
115 | return log_error_errno(errno, "Failed to create epoll object: %m"); | |
2ca0435b ZJS |
116 | |
117 | for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + count; fd++) { | |
30374ebe LP |
118 | _cleanup_free_ char *name = NULL; |
119 | ||
120 | getsockname_pretty(fd, &name); | |
2c408cb6 | 121 | log_info("Listening on %s as %i.", strna(name), fd); |
30374ebe | 122 | |
29a5ca9b | 123 | r = add_epoll(*epoll_fd, fd); |
2ca0435b ZJS |
124 | if (r < 0) |
125 | return r; | |
126 | } | |
127 | ||
128 | return count; | |
129 | } | |
130 | ||
23ea3dab | 131 | static int launch(char* name, char **argv, char **env, int fds) { |
30374ebe | 132 | |
2ca0435b | 133 | static const char* tocopy[] = {"TERM=", "PATH=", "USER=", "HOME="}; |
30374ebe | 134 | _cleanup_strv_free_ char **envp = NULL; |
7fd1b19b | 135 | _cleanup_free_ char *tmp = NULL; |
30374ebe LP |
136 | unsigned n_env = 0, length; |
137 | char **s; | |
2ca0435b ZJS |
138 | unsigned i; |
139 | ||
892213bf | 140 | length = strv_length(arg_setenv); |
30374ebe | 141 | |
8dd4c05b LP |
142 | /* PATH, TERM, HOME, USER, LISTEN_FDS, LISTEN_PID, LISTEN_FDNAMES, NULL */ |
143 | envp = new0(char *, length + 8); | |
30374ebe LP |
144 | if (!envp) |
145 | return log_oom(); | |
5e65c93a | 146 | |
892213bf | 147 | STRV_FOREACH(s, arg_setenv) { |
5e65c93a ZJS |
148 | if (strchr(*s, '=')) |
149 | envp[n_env++] = *s; | |
150 | else { | |
8dd4c05b LP |
151 | _cleanup_free_ char *p; |
152 | ||
153 | p = strappend(*s, "="); | |
5e65c93a ZJS |
154 | if (!p) |
155 | return log_oom(); | |
23ea3dab | 156 | envp[n_env] = strv_find_prefix(env, p); |
5e65c93a ZJS |
157 | if (envp[n_env]) |
158 | n_env ++; | |
159 | } | |
160 | } | |
161 | ||
2ca0435b | 162 | for (i = 0; i < ELEMENTSOF(tocopy); i++) { |
23ea3dab | 163 | envp[n_env] = strv_find_prefix(env, tocopy[i]); |
2ca0435b ZJS |
164 | if (envp[n_env]) |
165 | n_env ++; | |
166 | } | |
167 | ||
168 | if ((asprintf((char**)(envp + n_env++), "LISTEN_FDS=%d", fds) < 0) || | |
169 | (asprintf((char**)(envp + n_env++), "LISTEN_PID=%d", getpid()) < 0)) | |
170 | return log_oom(); | |
171 | ||
8dd4c05b LP |
172 | if (arg_fdname) { |
173 | char *e; | |
174 | ||
175 | e = strappend("LISTEN_FDNAMES=", arg_fdname); | |
176 | if (!e) | |
177 | return log_oom(); | |
178 | ||
179 | for (i = 1; i < (unsigned) fds; i++) { | |
180 | char *c; | |
181 | ||
182 | c = strjoin(e, ":", arg_fdname, NULL); | |
183 | if (!c) { | |
184 | free(e); | |
185 | return log_oom(); | |
186 | } | |
187 | ||
188 | free(e); | |
189 | e = c; | |
190 | } | |
191 | ||
192 | envp[n_env++] = e; | |
193 | } | |
194 | ||
2ca0435b ZJS |
195 | tmp = strv_join(argv, " "); |
196 | if (!tmp) | |
197 | return log_oom(); | |
198 | ||
199 | log_info("Execing %s (%s)", name, tmp); | |
200 | execvpe(name, argv, envp); | |
30374ebe | 201 | |
8dd4c05b | 202 | return log_error_errno(errno, "Failed to execp %s (%s): %m", name, tmp); |
2ca0435b ZJS |
203 | } |
204 | ||
23ea3dab | 205 | static int launch1(const char* child, char** argv, char **env, int fd) { |
30374ebe | 206 | _cleanup_free_ char *tmp = NULL; |
2ca0435b ZJS |
207 | pid_t parent_pid, child_pid; |
208 | int r; | |
209 | ||
2ca0435b ZJS |
210 | tmp = strv_join(argv, " "); |
211 | if (!tmp) | |
212 | return log_oom(); | |
213 | ||
214 | parent_pid = getpid(); | |
215 | ||
216 | child_pid = fork(); | |
4a62c710 MS |
217 | if (child_pid < 0) |
218 | return log_error_errno(errno, "Failed to fork: %m"); | |
2ca0435b ZJS |
219 | |
220 | /* In the child */ | |
221 | if (child_pid == 0) { | |
ce30c8dc LP |
222 | |
223 | (void) reset_all_signal_handlers(); | |
224 | (void) reset_signal_mask(); | |
225 | ||
2ca0435b ZJS |
226 | r = dup2(fd, STDIN_FILENO); |
227 | if (r < 0) { | |
56f64d95 | 228 | log_error_errno(errno, "Failed to dup connection to stdin: %m"); |
2ca0435b ZJS |
229 | _exit(EXIT_FAILURE); |
230 | } | |
231 | ||
232 | r = dup2(fd, STDOUT_FILENO); | |
233 | if (r < 0) { | |
56f64d95 | 234 | log_error_errno(errno, "Failed to dup connection to stdout: %m"); |
2ca0435b ZJS |
235 | _exit(EXIT_FAILURE); |
236 | } | |
237 | ||
238 | r = close(fd); | |
239 | if (r < 0) { | |
56f64d95 | 240 | log_error_errno(errno, "Failed to close dupped connection: %m"); |
2ca0435b ZJS |
241 | _exit(EXIT_FAILURE); |
242 | } | |
243 | ||
244 | /* Make sure the child goes away when the parent dies */ | |
245 | if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0) | |
246 | _exit(EXIT_FAILURE); | |
247 | ||
248 | /* Check whether our parent died before we were able | |
249 | * to set the death signal */ | |
250 | if (getppid() != parent_pid) | |
251 | _exit(EXIT_SUCCESS); | |
252 | ||
253 | execvp(child, argv); | |
56f64d95 | 254 | log_error_errno(errno, "Failed to exec child %s: %m", child); |
2ca0435b ZJS |
255 | _exit(EXIT_FAILURE); |
256 | } | |
257 | ||
258 | log_info("Spawned %s (%s) as PID %d", child, tmp, child_pid); | |
259 | ||
260 | return 0; | |
261 | } | |
262 | ||
263 | static int do_accept(const char* name, char **argv, char **envp, int fd) { | |
30374ebe | 264 | _cleanup_free_ char *local = NULL, *peer = NULL; |
aa44499d | 265 | _cleanup_close_ int fd2 = -1; |
2ca0435b | 266 | |
30374ebe | 267 | fd2 = accept(fd, NULL, NULL); |
2ca0435b | 268 | if (fd2 < 0) { |
56f64d95 | 269 | log_error_errno(errno, "Failed to accept connection on fd:%d: %m", fd); |
2ca0435b ZJS |
270 | return fd2; |
271 | } | |
272 | ||
30374ebe LP |
273 | getsockname_pretty(fd2, &local); |
274 | getpeername_pretty(fd2, &peer); | |
275 | log_info("Connection from %s to %s", strna(peer), strna(local)); | |
2ca0435b | 276 | |
30374ebe | 277 | return launch1(name, argv, envp, fd2); |
2ca0435b ZJS |
278 | } |
279 | ||
280 | /* SIGCHLD handler. */ | |
e9c1ea9d | 281 | static void sigchld_hdl(int sig, siginfo_t *t, void *data) { |
9d458c09 LP |
282 | PROTECT_ERRNO; |
283 | ||
2ca0435b | 284 | log_info("Child %d died with code %d", t->si_pid, t->si_status); |
e9c1ea9d JSJ |
285 | /* Wait for a dead child. */ |
286 | waitpid(t->si_pid, NULL, 0); | |
2ca0435b ZJS |
287 | } |
288 | ||
289 | static int install_chld_handler(void) { | |
290 | int r; | |
c0997164 ZJS |
291 | struct sigaction act = { |
292 | .sa_flags = SA_SIGINFO, | |
293 | .sa_sigaction = sigchld_hdl, | |
294 | }; | |
2ca0435b ZJS |
295 | |
296 | r = sigaction(SIGCHLD, &act, 0); | |
297 | if (r < 0) | |
56f64d95 | 298 | log_error_errno(errno, "Failed to install SIGCHLD handler: %m"); |
2ca0435b ZJS |
299 | return r; |
300 | } | |
301 | ||
601185b4 | 302 | static void help(void) { |
2ca0435b ZJS |
303 | printf("%s [OPTIONS...]\n\n" |
304 | "Listen on sockets and launch child on connection.\n\n" | |
305 | "Options:\n" | |
892213bf ZJS |
306 | " -l --listen=ADDR Listen for raw connections at ADDR\n" |
307 | " -a --accept Spawn separate child for each connection\n" | |
308 | " -h --help Show this help and exit\n" | |
309 | " -E --setenv=NAME[=VALUE] Pass an environment variable to children\n" | |
310 | " --version Print version string and exit\n" | |
2ca0435b ZJS |
311 | "\n" |
312 | "Note: file descriptors from sd_listen_fds() will be passed through.\n" | |
601185b4 | 313 | , program_invocation_short_name); |
2ca0435b ZJS |
314 | } |
315 | ||
316 | static int parse_argv(int argc, char *argv[]) { | |
317 | enum { | |
318 | ARG_VERSION = 0x100, | |
8dd4c05b | 319 | ARG_FDNAME, |
2ca0435b ZJS |
320 | }; |
321 | ||
322 | static const struct option options[] = { | |
892213bf ZJS |
323 | { "help", no_argument, NULL, 'h' }, |
324 | { "version", no_argument, NULL, ARG_VERSION }, | |
325 | { "listen", required_argument, NULL, 'l' }, | |
326 | { "accept", no_argument, NULL, 'a' }, | |
327 | { "setenv", required_argument, NULL, 'E' }, | |
8dd4c05b LP |
328 | { "environment", required_argument, NULL, 'E' }, /* legacy alias */ |
329 | { "fdname", required_argument, NULL, ARG_FDNAME }, | |
eb9da376 | 330 | {} |
2ca0435b ZJS |
331 | }; |
332 | ||
8dd4c05b | 333 | int c, r; |
2ca0435b ZJS |
334 | |
335 | assert(argc >= 0); | |
336 | assert(argv); | |
337 | ||
ed655692 | 338 | while ((c = getopt_long(argc, argv, "+hl:aE:", options, NULL)) >= 0) |
2ca0435b ZJS |
339 | switch(c) { |
340 | case 'h': | |
601185b4 ZJS |
341 | help(); |
342 | return 0; | |
2ca0435b ZJS |
343 | |
344 | case ARG_VERSION: | |
3f6fd1ba | 345 | return version(); |
2ca0435b | 346 | |
8dd4c05b LP |
347 | case 'l': |
348 | r = strv_extend(&arg_listen, optarg); | |
2ca0435b | 349 | if (r < 0) |
8dd4c05b | 350 | return log_oom(); |
2ca0435b ZJS |
351 | |
352 | break; | |
2ca0435b ZJS |
353 | |
354 | case 'a': | |
355 | arg_accept = true; | |
356 | break; | |
357 | ||
8dd4c05b LP |
358 | case 'E': |
359 | r = strv_extend(&arg_setenv, optarg); | |
5e65c93a | 360 | if (r < 0) |
8dd4c05b | 361 | return log_oom(); |
5e65c93a ZJS |
362 | |
363 | break; | |
8dd4c05b LP |
364 | |
365 | case ARG_FDNAME: | |
163c76c9 LP |
366 | if (!fdname_is_valid(optarg)) { |
367 | log_error("File descriptor name %s is not valid, refusing.", optarg); | |
368 | return -EINVAL; | |
369 | } | |
370 | ||
8dd4c05b LP |
371 | arg_fdname = optarg; |
372 | break; | |
5e65c93a | 373 | |
2ca0435b ZJS |
374 | case '?': |
375 | return -EINVAL; | |
376 | ||
377 | default: | |
eb9da376 | 378 | assert_not_reached("Unhandled option"); |
2ca0435b ZJS |
379 | } |
380 | ||
381 | if (optind == argc) { | |
601185b4 | 382 | log_error("%s: command to execute is missing.", |
2ca0435b ZJS |
383 | program_invocation_short_name); |
384 | return -EINVAL; | |
385 | } | |
386 | ||
387 | arg_args = argv + optind; | |
388 | ||
389 | return 1 /* work to do */; | |
390 | } | |
391 | ||
392 | int main(int argc, char **argv, char **envp) { | |
393 | int r, n; | |
394 | int epoll_fd = -1; | |
395 | ||
2ca0435b | 396 | log_parse_environment(); |
eceb8483 | 397 | log_open(); |
2ca0435b ZJS |
398 | |
399 | r = parse_argv(argc, argv); | |
400 | if (r <= 0) | |
401 | return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE; | |
402 | ||
403 | r = install_chld_handler(); | |
404 | if (r < 0) | |
405 | return EXIT_FAILURE; | |
406 | ||
407 | n = open_sockets(&epoll_fd, arg_accept); | |
408 | if (n < 0) | |
409 | return EXIT_FAILURE; | |
2c408cb6 LP |
410 | if (n == 0) { |
411 | log_error("No sockets to listen on specified or passed in."); | |
412 | return EXIT_FAILURE; | |
413 | } | |
2ca0435b | 414 | |
eceb8483 | 415 | for (;;) { |
2ca0435b ZJS |
416 | struct epoll_event event; |
417 | ||
418 | r = epoll_wait(epoll_fd, &event, 1, -1); | |
419 | if (r < 0) { | |
420 | if (errno == EINTR) | |
421 | continue; | |
422 | ||
56f64d95 | 423 | log_error_errno(errno, "epoll_wait() failed: %m"); |
2ca0435b ZJS |
424 | return EXIT_FAILURE; |
425 | } | |
426 | ||
2c408cb6 | 427 | log_info("Communication attempt on fd %i.", event.data.fd); |
2ca0435b ZJS |
428 | if (arg_accept) { |
429 | r = do_accept(argv[optind], argv + optind, envp, | |
430 | event.data.fd); | |
431 | if (r < 0) | |
432 | return EXIT_FAILURE; | |
433 | } else | |
434 | break; | |
435 | } | |
436 | ||
437 | launch(argv[optind], argv + optind, envp, n); | |
438 | ||
439 | return EXIT_SUCCESS; | |
440 | } |