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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
2ca0435b ZJS |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2013 Zbigniew Jędrzejewski-Szmek | |
2ca0435b ZJS |
6 | ***/ |
7 | ||
3f6fd1ba | 8 | #include <getopt.h> |
2ca0435b ZJS |
9 | #include <sys/epoll.h> |
10 | #include <sys/prctl.h> | |
11 | #include <sys/socket.h> | |
12 | #include <sys/wait.h> | |
3f6fd1ba | 13 | #include <unistd.h> |
2ca0435b | 14 | |
8dd4c05b | 15 | #include "sd-daemon.h" |
2ca0435b | 16 | |
b5efdb8a | 17 | #include "alloc-util.h" |
cf98937c | 18 | #include "escape.h" |
b5efdb8a | 19 | #include "fd-util.h" |
2ca0435b | 20 | #include "log.h" |
2ca0435b | 21 | #include "macro.h" |
df0ff127 | 22 | #include "process-util.h" |
ce30c8dc | 23 | #include "signal-util.h" |
3f6fd1ba | 24 | #include "socket-util.h" |
07630cea | 25 | #include "string-util.h" |
3f6fd1ba | 26 | #include "strv.h" |
2ca0435b ZJS |
27 | |
28 | static char** arg_listen = NULL; | |
29 | static bool arg_accept = false; | |
d31e430f | 30 | static int arg_socket_type = SOCK_STREAM; |
2ca0435b | 31 | static char** arg_args = NULL; |
892213bf | 32 | static char** arg_setenv = NULL; |
cf98937c | 33 | static char **arg_fdnames = NULL; |
eef0a274 | 34 | static bool arg_inetd = false; |
2ca0435b ZJS |
35 | |
36 | static int add_epoll(int epoll_fd, int fd) { | |
30374ebe LP |
37 | struct epoll_event ev = { |
38 | .events = EPOLLIN | |
39 | }; | |
2ca0435b | 40 | int r; |
2ca0435b ZJS |
41 | |
42 | assert(epoll_fd >= 0); | |
43 | assert(fd >= 0); | |
44 | ||
30374ebe | 45 | ev.data.fd = fd; |
2ca0435b | 46 | r = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev); |
4a62c710 MS |
47 | if (r < 0) |
48 | return log_error_errno(errno, "Failed to add event on epoll fd:%d for fd:%d: %m", epoll_fd, fd); | |
603938e0 LP |
49 | |
50 | return 0; | |
2ca0435b ZJS |
51 | } |
52 | ||
53 | static int open_sockets(int *epoll_fd, bool accept) { | |
30374ebe | 54 | char **address; |
29a5ca9b | 55 | int n, fd, r; |
2ca0435b | 56 | int count = 0; |
2ca0435b ZJS |
57 | |
58 | n = sd_listen_fds(true); | |
eb56eb9b MS |
59 | if (n < 0) |
60 | return log_error_errno(n, "Failed to read listening file descriptors from environment: %m"); | |
30374ebe LP |
61 | if (n > 0) { |
62 | log_info("Received %i descriptors via the environment.", n); | |
2ca0435b | 63 | |
30374ebe LP |
64 | for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++) { |
65 | r = fd_cloexec(fd, arg_accept); | |
66 | if (r < 0) | |
67 | return r; | |
2ca0435b | 68 | |
313cefa1 | 69 | count++; |
30374ebe | 70 | } |
2ca0435b ZJS |
71 | } |
72 | ||
c0997164 ZJS |
73 | /* Close logging and all other descriptors */ |
74 | if (arg_listen) { | |
75 | int except[3 + n]; | |
76 | ||
77 | for (fd = 0; fd < SD_LISTEN_FDS_START + n; fd++) | |
78 | except[fd] = fd; | |
79 | ||
80 | log_close(); | |
81 | close_all_fds(except, 3 + n); | |
82 | } | |
83 | ||
fff40a51 ZJS |
84 | /** Note: we leak some fd's on error here. I doesn't matter |
85 | * much, since the program will exit immediately anyway, but | |
86 | * would be a pain to fix. | |
87 | */ | |
88 | ||
2ca0435b | 89 | STRV_FOREACH(address, arg_listen) { |
d31e430f | 90 | fd = make_socket_fd(LOG_DEBUG, *address, arg_socket_type, (arg_accept*SOCK_CLOEXEC)); |
2ca0435b | 91 | if (fd < 0) { |
c0997164 | 92 | log_open(); |
23bbb0de | 93 | return log_error_errno(fd, "Failed to open '%s': %m", *address); |
2ca0435b ZJS |
94 | } |
95 | ||
175a3d25 | 96 | assert(fd == SD_LISTEN_FDS_START + count); |
313cefa1 | 97 | count++; |
2ca0435b ZJS |
98 | } |
99 | ||
c0997164 ZJS |
100 | if (arg_listen) |
101 | log_open(); | |
102 | ||
2ca0435b | 103 | *epoll_fd = epoll_create1(EPOLL_CLOEXEC); |
4a62c710 MS |
104 | if (*epoll_fd < 0) |
105 | return log_error_errno(errno, "Failed to create epoll object: %m"); | |
2ca0435b ZJS |
106 | |
107 | for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + count; fd++) { | |
30374ebe LP |
108 | _cleanup_free_ char *name = NULL; |
109 | ||
110 | getsockname_pretty(fd, &name); | |
2c408cb6 | 111 | log_info("Listening on %s as %i.", strna(name), fd); |
30374ebe | 112 | |
29a5ca9b | 113 | r = add_epoll(*epoll_fd, fd); |
2ca0435b ZJS |
114 | if (r < 0) |
115 | return r; | |
116 | } | |
117 | ||
118 | return count; | |
119 | } | |
120 | ||
eef0a274 | 121 | static int exec_process(const char* name, char **argv, char **env, int start_fd, int n_fds) { |
30374ebe | 122 | |
30374ebe | 123 | _cleanup_strv_free_ char **envp = NULL; |
eef0a274 | 124 | _cleanup_free_ char *joined = NULL; |
30374ebe | 125 | unsigned n_env = 0, length; |
eef0a274 | 126 | const char *tocopy; |
eef0a274 LP |
127 | char **s; |
128 | int r; | |
129 | ||
130 | if (arg_inetd && n_fds != 1) { | |
131 | log_error("--inetd only supported for single file descriptors."); | |
132 | return -EINVAL; | |
133 | } | |
2ca0435b | 134 | |
892213bf | 135 | length = strv_length(arg_setenv); |
30374ebe | 136 | |
8dd4c05b LP |
137 | /* PATH, TERM, HOME, USER, LISTEN_FDS, LISTEN_PID, LISTEN_FDNAMES, NULL */ |
138 | envp = new0(char *, length + 8); | |
30374ebe LP |
139 | if (!envp) |
140 | return log_oom(); | |
5e65c93a | 141 | |
892213bf | 142 | STRV_FOREACH(s, arg_setenv) { |
eef0a274 | 143 | |
fa994f91 LP |
144 | if (strchr(*s, '=')) { |
145 | char *k; | |
146 | ||
147 | k = strdup(*s); | |
148 | if (!k) | |
149 | return log_oom(); | |
150 | ||
151 | envp[n_env++] = k; | |
152 | } else { | |
8dd4c05b | 153 | _cleanup_free_ char *p; |
fa994f91 | 154 | const char *n; |
8dd4c05b LP |
155 | |
156 | p = strappend(*s, "="); | |
5e65c93a ZJS |
157 | if (!p) |
158 | return log_oom(); | |
fa994f91 LP |
159 | |
160 | n = strv_find_prefix(env, p); | |
161 | if (!n) | |
162 | continue; | |
163 | ||
164 | envp[n_env] = strdup(n); | |
165 | if (!envp[n_env]) | |
166 | return log_oom(); | |
eef0a274 | 167 | |
313cefa1 | 168 | n_env++; |
5e65c93a ZJS |
169 | } |
170 | } | |
171 | ||
eef0a274 | 172 | FOREACH_STRING(tocopy, "TERM=", "PATH=", "USER=", "HOME=") { |
fa994f91 LP |
173 | const char *n; |
174 | ||
eef0a274 | 175 | n = strv_find_prefix(env, tocopy); |
fa994f91 LP |
176 | if (!n) |
177 | continue; | |
178 | ||
179 | envp[n_env] = strdup(n); | |
180 | if (!envp[n_env]) | |
181 | return log_oom(); | |
182 | ||
313cefa1 | 183 | n_env++; |
2ca0435b ZJS |
184 | } |
185 | ||
eef0a274 LP |
186 | if (arg_inetd) { |
187 | assert(n_fds == 1); | |
2ca0435b | 188 | |
2b33ab09 | 189 | r = rearrange_stdio(start_fd, start_fd, STDERR_FILENO); /* invalidates start_fd on success + error */ |
eef0a274 | 190 | if (r < 0) |
2b33ab09 | 191 | return log_error_errno(errno, "Failed to move fd to stdin+stdout: %m"); |
8dd4c05b | 192 | |
eef0a274 LP |
193 | } else { |
194 | if (start_fd != SD_LISTEN_FDS_START) { | |
195 | assert(n_fds == 1); | |
196 | ||
197 | r = dup2(start_fd, SD_LISTEN_FDS_START); | |
198 | if (r < 0) | |
199 | return log_error_errno(errno, "Failed to dup connection: %m"); | |
200 | ||
201 | safe_close(start_fd); | |
202 | start_fd = SD_LISTEN_FDS_START; | |
203 | } | |
204 | ||
205 | if (asprintf((char**)(envp + n_env++), "LISTEN_FDS=%i", n_fds) < 0) | |
8dd4c05b LP |
206 | return log_oom(); |
207 | ||
df0ff127 | 208 | if (asprintf((char**)(envp + n_env++), "LISTEN_PID=" PID_FMT, getpid_cached()) < 0) |
eef0a274 | 209 | return log_oom(); |
8dd4c05b | 210 | |
cf98937c ZJS |
211 | if (arg_fdnames) { |
212 | _cleanup_free_ char *names = NULL; | |
213 | size_t len; | |
eef0a274 | 214 | char *e; |
cf98937c ZJS |
215 | int i; |
216 | ||
217 | len = strv_length(arg_fdnames); | |
218 | if (len == 1) | |
219 | for (i = 1; i < n_fds; i++) { | |
220 | r = strv_extend(&arg_fdnames, arg_fdnames[0]); | |
221 | if (r < 0) | |
222 | return log_error_errno(r, "Failed to extend strv: %m"); | |
223 | } | |
224 | else if (len != (unsigned) n_fds) | |
225 | log_warning("The number of fd names is different than number of fds: %zu vs %d", | |
226 | len, n_fds); | |
eef0a274 | 227 | |
cf98937c ZJS |
228 | names = strv_join(arg_fdnames, ":"); |
229 | if (!names) | |
8dd4c05b | 230 | return log_oom(); |
eef0a274 | 231 | |
cf98937c ZJS |
232 | e = strappend("LISTEN_FDNAMES=", names); |
233 | if (!e) | |
234 | return log_oom(); | |
8dd4c05b | 235 | |
eef0a274 | 236 | envp[n_env++] = e; |
8dd4c05b | 237 | } |
8dd4c05b LP |
238 | } |
239 | ||
eef0a274 LP |
240 | joined = strv_join(argv, " "); |
241 | if (!joined) | |
2ca0435b ZJS |
242 | return log_oom(); |
243 | ||
eef0a274 | 244 | log_info("Execing %s (%s)", name, joined); |
2ca0435b | 245 | execvpe(name, argv, envp); |
30374ebe | 246 | |
eef0a274 | 247 | return log_error_errno(errno, "Failed to execp %s (%s): %m", name, joined); |
2ca0435b ZJS |
248 | } |
249 | ||
eef0a274 LP |
250 | static int fork_and_exec_process(const char* child, char** argv, char **env, int fd) { |
251 | _cleanup_free_ char *joined = NULL; | |
4c253ed1 LP |
252 | pid_t child_pid; |
253 | int r; | |
2ca0435b | 254 | |
eef0a274 LP |
255 | joined = strv_join(argv, " "); |
256 | if (!joined) | |
2ca0435b ZJS |
257 | return log_oom(); |
258 | ||
b6e1fff1 | 259 | r = safe_fork("(activate)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &child_pid); |
4c253ed1 | 260 | if (r < 0) |
b6e1fff1 | 261 | return r; |
4c253ed1 LP |
262 | if (r == 0) { |
263 | /* In the child */ | |
eef0a274 | 264 | exec_process(child, argv, env, fd, 1); |
2ca0435b ZJS |
265 | _exit(EXIT_FAILURE); |
266 | } | |
267 | ||
4c253ed1 | 268 | log_info("Spawned %s (%s) as PID " PID_FMT ".", child, joined, child_pid); |
2ca0435b ZJS |
269 | return 0; |
270 | } | |
271 | ||
272 | static int do_accept(const char* name, char **argv, char **envp, int fd) { | |
30374ebe | 273 | _cleanup_free_ char *local = NULL, *peer = NULL; |
eef0a274 | 274 | _cleanup_close_ int fd_accepted = -1; |
2ca0435b | 275 | |
eef0a274 LP |
276 | fd_accepted = accept4(fd, NULL, NULL, 0); |
277 | if (fd_accepted < 0) | |
08719b64 | 278 | return log_error_errno(errno, "Failed to accept connection on fd:%d: %m", fd); |
2ca0435b | 279 | |
eef0a274 LP |
280 | getsockname_pretty(fd_accepted, &local); |
281 | getpeername_pretty(fd_accepted, true, &peer); | |
30374ebe | 282 | log_info("Connection from %s to %s", strna(peer), strna(local)); |
2ca0435b | 283 | |
eef0a274 | 284 | return fork_and_exec_process(name, argv, envp, fd_accepted); |
2ca0435b ZJS |
285 | } |
286 | ||
287 | /* SIGCHLD handler. */ | |
5488e52d | 288 | static void sigchld_hdl(int sig) { |
9d458c09 LP |
289 | PROTECT_ERRNO; |
290 | ||
5488e52d EV |
291 | for (;;) { |
292 | siginfo_t si; | |
293 | int r; | |
08719b64 | 294 | |
5488e52d EV |
295 | si.si_pid = 0; |
296 | r = waitid(P_ALL, 0, &si, WEXITED|WNOHANG); | |
297 | if (r < 0) { | |
298 | if (errno != ECHILD) | |
299 | log_error_errno(errno, "Failed to reap children: %m"); | |
300 | return; | |
301 | } | |
302 | if (si.si_pid == 0) | |
303 | return; | |
304 | ||
305 | log_info("Child %d died with code %d", si.si_pid, si.si_status); | |
306 | } | |
2ca0435b ZJS |
307 | } |
308 | ||
309 | static int install_chld_handler(void) { | |
08719b64 | 310 | static const struct sigaction act = { |
e28c7cd0 | 311 | .sa_flags = SA_NOCLDSTOP|SA_RESTART, |
5488e52d | 312 | .sa_handler = sigchld_hdl, |
c0997164 | 313 | }; |
2ca0435b | 314 | |
08719b64 LP |
315 | int r; |
316 | ||
2ca0435b ZJS |
317 | r = sigaction(SIGCHLD, &act, 0); |
318 | if (r < 0) | |
08719b64 LP |
319 | return log_error_errno(errno, "Failed to install SIGCHLD handler: %m"); |
320 | ||
321 | return 0; | |
2ca0435b ZJS |
322 | } |
323 | ||
601185b4 | 324 | static void help(void) { |
2ca0435b ZJS |
325 | printf("%s [OPTIONS...]\n\n" |
326 | "Listen on sockets and launch child on connection.\n\n" | |
327 | "Options:\n" | |
cf98937c ZJS |
328 | " -h --help Show this help and exit\n" |
329 | " --version Print version string and exit\n" | |
330 | " -l --listen=ADDR Listen for raw connections at ADDR\n" | |
331 | " -d --datagram Listen on datagram instead of stream socket\n" | |
332 | " --seqpacket Listen on SOCK_SEQPACKET instead of stream socket\n" | |
333 | " -a --accept Spawn separate child for each connection\n" | |
334 | " -E --setenv=NAME[=VALUE] Pass an environment variable to children\n" | |
335 | " --fdname=NAME[:NAME...] Specify names for file descriptors\n" | |
336 | " --inetd Enable inetd file descriptor passing protocol\n" | |
2ca0435b ZJS |
337 | "\n" |
338 | "Note: file descriptors from sd_listen_fds() will be passed through.\n" | |
601185b4 | 339 | , program_invocation_short_name); |
2ca0435b ZJS |
340 | } |
341 | ||
342 | static int parse_argv(int argc, char *argv[]) { | |
343 | enum { | |
344 | ARG_VERSION = 0x100, | |
8dd4c05b | 345 | ARG_FDNAME, |
d31e430f | 346 | ARG_SEQPACKET, |
eef0a274 | 347 | ARG_INETD, |
2ca0435b ZJS |
348 | }; |
349 | ||
350 | static const struct option options[] = { | |
892213bf ZJS |
351 | { "help", no_argument, NULL, 'h' }, |
352 | { "version", no_argument, NULL, ARG_VERSION }, | |
7b7afdfc | 353 | { "datagram", no_argument, NULL, 'd' }, |
d31e430f | 354 | { "seqpacket", no_argument, NULL, ARG_SEQPACKET }, |
892213bf ZJS |
355 | { "listen", required_argument, NULL, 'l' }, |
356 | { "accept", no_argument, NULL, 'a' }, | |
357 | { "setenv", required_argument, NULL, 'E' }, | |
8dd4c05b LP |
358 | { "environment", required_argument, NULL, 'E' }, /* legacy alias */ |
359 | { "fdname", required_argument, NULL, ARG_FDNAME }, | |
eef0a274 | 360 | { "inetd", no_argument, NULL, ARG_INETD }, |
eb9da376 | 361 | {} |
2ca0435b ZJS |
362 | }; |
363 | ||
8dd4c05b | 364 | int c, r; |
2ca0435b ZJS |
365 | |
366 | assert(argc >= 0); | |
367 | assert(argv); | |
368 | ||
b722348d | 369 | while ((c = getopt_long(argc, argv, "+hl:aE:d", options, NULL)) >= 0) |
2ca0435b ZJS |
370 | switch(c) { |
371 | case 'h': | |
601185b4 ZJS |
372 | help(); |
373 | return 0; | |
2ca0435b ZJS |
374 | |
375 | case ARG_VERSION: | |
3f6fd1ba | 376 | return version(); |
2ca0435b | 377 | |
8dd4c05b LP |
378 | case 'l': |
379 | r = strv_extend(&arg_listen, optarg); | |
2ca0435b | 380 | if (r < 0) |
8dd4c05b | 381 | return log_oom(); |
2ca0435b ZJS |
382 | |
383 | break; | |
2ca0435b | 384 | |
7b7afdfc | 385 | case 'd': |
d31e430f LP |
386 | if (arg_socket_type == SOCK_SEQPACKET) { |
387 | log_error("--datagram may not be combined with --seqpacket."); | |
388 | return -EINVAL; | |
389 | } | |
390 | ||
391 | arg_socket_type = SOCK_DGRAM; | |
392 | break; | |
393 | ||
394 | case ARG_SEQPACKET: | |
395 | if (arg_socket_type == SOCK_DGRAM) { | |
396 | log_error("--seqpacket may not be combined with --datagram."); | |
397 | return -EINVAL; | |
398 | } | |
399 | ||
400 | arg_socket_type = SOCK_SEQPACKET; | |
7b7afdfc SS |
401 | break; |
402 | ||
2ca0435b ZJS |
403 | case 'a': |
404 | arg_accept = true; | |
405 | break; | |
406 | ||
8dd4c05b LP |
407 | case 'E': |
408 | r = strv_extend(&arg_setenv, optarg); | |
5e65c93a | 409 | if (r < 0) |
8dd4c05b | 410 | return log_oom(); |
5e65c93a ZJS |
411 | |
412 | break; | |
8dd4c05b | 413 | |
cf98937c ZJS |
414 | case ARG_FDNAME: { |
415 | _cleanup_strv_free_ char **names; | |
416 | char **s; | |
417 | ||
418 | names = strv_split(optarg, ":"); | |
419 | if (!names) | |
420 | return log_oom(); | |
421 | ||
422 | STRV_FOREACH(s, names) | |
423 | if (!fdname_is_valid(*s)) { | |
424 | _cleanup_free_ char *esc; | |
163c76c9 | 425 | |
cf98937c ZJS |
426 | esc = cescape(*s); |
427 | log_warning("File descriptor name \"%s\" is not valid.", esc); | |
428 | } | |
429 | ||
430 | /* Empty optargs means one empty name */ | |
431 | r = strv_extend_strv(&arg_fdnames, | |
432 | strv_isempty(names) ? STRV_MAKE("") : names, | |
433 | false); | |
434 | if (r < 0) | |
435 | return log_error_errno(r, "strv_extend_strv: %m"); | |
8dd4c05b | 436 | break; |
cf98937c | 437 | } |
5e65c93a | 438 | |
eef0a274 LP |
439 | case ARG_INETD: |
440 | arg_inetd = true; | |
441 | break; | |
442 | ||
2ca0435b ZJS |
443 | case '?': |
444 | return -EINVAL; | |
445 | ||
446 | default: | |
eb9da376 | 447 | assert_not_reached("Unhandled option"); |
2ca0435b ZJS |
448 | } |
449 | ||
450 | if (optind == argc) { | |
601185b4 | 451 | log_error("%s: command to execute is missing.", |
2ca0435b ZJS |
452 | program_invocation_short_name); |
453 | return -EINVAL; | |
454 | } | |
455 | ||
d31e430f | 456 | if (arg_socket_type == SOCK_DGRAM && arg_accept) { |
7b7afdfc SS |
457 | log_error("Datagram sockets do not accept connections. " |
458 | "The --datagram and --accept options may not be combined."); | |
459 | return -EINVAL; | |
460 | } | |
461 | ||
2ca0435b ZJS |
462 | arg_args = argv + optind; |
463 | ||
464 | return 1 /* work to do */; | |
465 | } | |
466 | ||
467 | int main(int argc, char **argv, char **envp) { | |
468 | int r, n; | |
469 | int epoll_fd = -1; | |
470 | ||
2ca0435b | 471 | log_parse_environment(); |
eceb8483 | 472 | log_open(); |
2ca0435b ZJS |
473 | |
474 | r = parse_argv(argc, argv); | |
475 | if (r <= 0) | |
476 | return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE; | |
477 | ||
478 | r = install_chld_handler(); | |
479 | if (r < 0) | |
480 | return EXIT_FAILURE; | |
481 | ||
482 | n = open_sockets(&epoll_fd, arg_accept); | |
483 | if (n < 0) | |
484 | return EXIT_FAILURE; | |
2c408cb6 LP |
485 | if (n == 0) { |
486 | log_error("No sockets to listen on specified or passed in."); | |
487 | return EXIT_FAILURE; | |
488 | } | |
2ca0435b | 489 | |
eceb8483 | 490 | for (;;) { |
2ca0435b ZJS |
491 | struct epoll_event event; |
492 | ||
493 | r = epoll_wait(epoll_fd, &event, 1, -1); | |
494 | if (r < 0) { | |
495 | if (errno == EINTR) | |
496 | continue; | |
497 | ||
56f64d95 | 498 | log_error_errno(errno, "epoll_wait() failed: %m"); |
2ca0435b ZJS |
499 | return EXIT_FAILURE; |
500 | } | |
501 | ||
2c408cb6 | 502 | log_info("Communication attempt on fd %i.", event.data.fd); |
2ca0435b | 503 | if (arg_accept) { |
d31e430f | 504 | r = do_accept(argv[optind], argv + optind, envp, event.data.fd); |
2ca0435b ZJS |
505 | if (r < 0) |
506 | return EXIT_FAILURE; | |
507 | } else | |
508 | break; | |
509 | } | |
510 | ||
eef0a274 | 511 | exec_process(argv[optind], argv + optind, envp, SD_LISTEN_FDS_START, n); |
2ca0435b ZJS |
512 | |
513 | return EXIT_SUCCESS; | |
514 | } |