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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 | 37 | struct epoll_event ev = { |
b1c05b98 ZJS |
38 | .events = EPOLLIN, |
39 | .data.fd = fd, | |
30374ebe | 40 | }; |
2ca0435b ZJS |
41 | |
42 | assert(epoll_fd >= 0); | |
43 | assert(fd >= 0); | |
44 | ||
b1c05b98 | 45 | if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) |
4a62c710 | 46 | return log_error_errno(errno, "Failed to add event on epoll fd:%d for fd:%d: %m", epoll_fd, fd); |
603938e0 LP |
47 | |
48 | return 0; | |
2ca0435b ZJS |
49 | } |
50 | ||
51 | static int open_sockets(int *epoll_fd, bool accept) { | |
30374ebe | 52 | char **address; |
29a5ca9b | 53 | int n, fd, r; |
2ca0435b | 54 | int count = 0; |
2ca0435b ZJS |
55 | |
56 | n = sd_listen_fds(true); | |
eb56eb9b MS |
57 | if (n < 0) |
58 | return log_error_errno(n, "Failed to read listening file descriptors from environment: %m"); | |
30374ebe LP |
59 | if (n > 0) { |
60 | log_info("Received %i descriptors via the environment.", n); | |
2ca0435b | 61 | |
30374ebe LP |
62 | for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++) { |
63 | r = fd_cloexec(fd, arg_accept); | |
64 | if (r < 0) | |
65 | return r; | |
2ca0435b | 66 | |
313cefa1 | 67 | count++; |
30374ebe | 68 | } |
2ca0435b ZJS |
69 | } |
70 | ||
c0997164 ZJS |
71 | /* Close logging and all other descriptors */ |
72 | if (arg_listen) { | |
73 | int except[3 + n]; | |
74 | ||
75 | for (fd = 0; fd < SD_LISTEN_FDS_START + n; fd++) | |
76 | except[fd] = fd; | |
77 | ||
78 | log_close(); | |
79 | close_all_fds(except, 3 + n); | |
80 | } | |
81 | ||
fff40a51 ZJS |
82 | /** Note: we leak some fd's on error here. I doesn't matter |
83 | * much, since the program will exit immediately anyway, but | |
84 | * would be a pain to fix. | |
85 | */ | |
86 | ||
2ca0435b | 87 | STRV_FOREACH(address, arg_listen) { |
d31e430f | 88 | fd = make_socket_fd(LOG_DEBUG, *address, arg_socket_type, (arg_accept*SOCK_CLOEXEC)); |
2ca0435b | 89 | if (fd < 0) { |
c0997164 | 90 | log_open(); |
23bbb0de | 91 | return log_error_errno(fd, "Failed to open '%s': %m", *address); |
2ca0435b ZJS |
92 | } |
93 | ||
175a3d25 | 94 | assert(fd == SD_LISTEN_FDS_START + count); |
313cefa1 | 95 | count++; |
2ca0435b ZJS |
96 | } |
97 | ||
c0997164 ZJS |
98 | if (arg_listen) |
99 | log_open(); | |
100 | ||
2ca0435b | 101 | *epoll_fd = epoll_create1(EPOLL_CLOEXEC); |
4a62c710 MS |
102 | if (*epoll_fd < 0) |
103 | return log_error_errno(errno, "Failed to create epoll object: %m"); | |
2ca0435b ZJS |
104 | |
105 | for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + count; fd++) { | |
30374ebe LP |
106 | _cleanup_free_ char *name = NULL; |
107 | ||
108 | getsockname_pretty(fd, &name); | |
2c408cb6 | 109 | log_info("Listening on %s as %i.", strna(name), fd); |
30374ebe | 110 | |
29a5ca9b | 111 | r = add_epoll(*epoll_fd, fd); |
2ca0435b ZJS |
112 | if (r < 0) |
113 | return r; | |
114 | } | |
115 | ||
116 | return count; | |
117 | } | |
118 | ||
eef0a274 | 119 | static int exec_process(const char* name, char **argv, char **env, int start_fd, int n_fds) { |
30374ebe | 120 | |
30374ebe | 121 | _cleanup_strv_free_ char **envp = NULL; |
eef0a274 | 122 | _cleanup_free_ char *joined = NULL; |
30374ebe | 123 | unsigned n_env = 0, length; |
eef0a274 | 124 | const char *tocopy; |
eef0a274 LP |
125 | char **s; |
126 | int r; | |
127 | ||
128 | if (arg_inetd && n_fds != 1) { | |
129 | log_error("--inetd only supported for single file descriptors."); | |
130 | return -EINVAL; | |
131 | } | |
2ca0435b | 132 | |
892213bf | 133 | length = strv_length(arg_setenv); |
30374ebe | 134 | |
8dd4c05b LP |
135 | /* PATH, TERM, HOME, USER, LISTEN_FDS, LISTEN_PID, LISTEN_FDNAMES, NULL */ |
136 | envp = new0(char *, length + 8); | |
30374ebe LP |
137 | if (!envp) |
138 | return log_oom(); | |
5e65c93a | 139 | |
892213bf | 140 | STRV_FOREACH(s, arg_setenv) { |
eef0a274 | 141 | |
fa994f91 LP |
142 | if (strchr(*s, '=')) { |
143 | char *k; | |
144 | ||
145 | k = strdup(*s); | |
146 | if (!k) | |
147 | return log_oom(); | |
148 | ||
149 | envp[n_env++] = k; | |
150 | } else { | |
8dd4c05b | 151 | _cleanup_free_ char *p; |
fa994f91 | 152 | const char *n; |
8dd4c05b LP |
153 | |
154 | p = strappend(*s, "="); | |
5e65c93a ZJS |
155 | if (!p) |
156 | return log_oom(); | |
fa994f91 LP |
157 | |
158 | n = strv_find_prefix(env, p); | |
159 | if (!n) | |
160 | continue; | |
161 | ||
162 | envp[n_env] = strdup(n); | |
163 | if (!envp[n_env]) | |
164 | return log_oom(); | |
eef0a274 | 165 | |
313cefa1 | 166 | n_env++; |
5e65c93a ZJS |
167 | } |
168 | } | |
169 | ||
eef0a274 | 170 | FOREACH_STRING(tocopy, "TERM=", "PATH=", "USER=", "HOME=") { |
fa994f91 LP |
171 | const char *n; |
172 | ||
eef0a274 | 173 | n = strv_find_prefix(env, tocopy); |
fa994f91 LP |
174 | if (!n) |
175 | continue; | |
176 | ||
177 | envp[n_env] = strdup(n); | |
178 | if (!envp[n_env]) | |
179 | return log_oom(); | |
180 | ||
313cefa1 | 181 | n_env++; |
2ca0435b ZJS |
182 | } |
183 | ||
eef0a274 LP |
184 | if (arg_inetd) { |
185 | assert(n_fds == 1); | |
2ca0435b | 186 | |
2b33ab09 | 187 | r = rearrange_stdio(start_fd, start_fd, STDERR_FILENO); /* invalidates start_fd on success + error */ |
eef0a274 | 188 | if (r < 0) |
4355f1c9 | 189 | return log_error_errno(r, "Failed to move fd to stdin+stdout: %m"); |
8dd4c05b | 190 | |
eef0a274 LP |
191 | } else { |
192 | if (start_fd != SD_LISTEN_FDS_START) { | |
193 | assert(n_fds == 1); | |
194 | ||
b1c05b98 | 195 | if (dup2(start_fd, SD_LISTEN_FDS_START) < 0) |
eef0a274 LP |
196 | return log_error_errno(errno, "Failed to dup connection: %m"); |
197 | ||
198 | safe_close(start_fd); | |
199 | start_fd = SD_LISTEN_FDS_START; | |
200 | } | |
201 | ||
202 | if (asprintf((char**)(envp + n_env++), "LISTEN_FDS=%i", n_fds) < 0) | |
8dd4c05b LP |
203 | return log_oom(); |
204 | ||
df0ff127 | 205 | if (asprintf((char**)(envp + n_env++), "LISTEN_PID=" PID_FMT, getpid_cached()) < 0) |
eef0a274 | 206 | return log_oom(); |
8dd4c05b | 207 | |
cf98937c ZJS |
208 | if (arg_fdnames) { |
209 | _cleanup_free_ char *names = NULL; | |
210 | size_t len; | |
eef0a274 | 211 | char *e; |
cf98937c ZJS |
212 | int i; |
213 | ||
214 | len = strv_length(arg_fdnames); | |
215 | if (len == 1) | |
216 | for (i = 1; i < n_fds; i++) { | |
217 | r = strv_extend(&arg_fdnames, arg_fdnames[0]); | |
218 | if (r < 0) | |
219 | return log_error_errno(r, "Failed to extend strv: %m"); | |
220 | } | |
221 | else if (len != (unsigned) n_fds) | |
222 | log_warning("The number of fd names is different than number of fds: %zu vs %d", | |
223 | len, n_fds); | |
eef0a274 | 224 | |
cf98937c ZJS |
225 | names = strv_join(arg_fdnames, ":"); |
226 | if (!names) | |
8dd4c05b | 227 | return log_oom(); |
eef0a274 | 228 | |
cf98937c ZJS |
229 | e = strappend("LISTEN_FDNAMES=", names); |
230 | if (!e) | |
231 | return log_oom(); | |
8dd4c05b | 232 | |
eef0a274 | 233 | envp[n_env++] = e; |
8dd4c05b | 234 | } |
8dd4c05b LP |
235 | } |
236 | ||
eef0a274 LP |
237 | joined = strv_join(argv, " "); |
238 | if (!joined) | |
2ca0435b ZJS |
239 | return log_oom(); |
240 | ||
eef0a274 | 241 | log_info("Execing %s (%s)", name, joined); |
2ca0435b | 242 | execvpe(name, argv, envp); |
30374ebe | 243 | |
eef0a274 | 244 | return log_error_errno(errno, "Failed to execp %s (%s): %m", name, joined); |
2ca0435b ZJS |
245 | } |
246 | ||
eef0a274 LP |
247 | static int fork_and_exec_process(const char* child, char** argv, char **env, int fd) { |
248 | _cleanup_free_ char *joined = NULL; | |
4c253ed1 LP |
249 | pid_t child_pid; |
250 | int r; | |
2ca0435b | 251 | |
eef0a274 LP |
252 | joined = strv_join(argv, " "); |
253 | if (!joined) | |
2ca0435b ZJS |
254 | return log_oom(); |
255 | ||
b6e1fff1 | 256 | r = safe_fork("(activate)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &child_pid); |
4c253ed1 | 257 | if (r < 0) |
b6e1fff1 | 258 | return r; |
4c253ed1 LP |
259 | if (r == 0) { |
260 | /* In the child */ | |
eef0a274 | 261 | exec_process(child, argv, env, fd, 1); |
2ca0435b ZJS |
262 | _exit(EXIT_FAILURE); |
263 | } | |
264 | ||
4c253ed1 | 265 | log_info("Spawned %s (%s) as PID " PID_FMT ".", child, joined, child_pid); |
2ca0435b ZJS |
266 | return 0; |
267 | } | |
268 | ||
269 | static int do_accept(const char* name, char **argv, char **envp, int fd) { | |
30374ebe | 270 | _cleanup_free_ char *local = NULL, *peer = NULL; |
eef0a274 | 271 | _cleanup_close_ int fd_accepted = -1; |
2ca0435b | 272 | |
eef0a274 LP |
273 | fd_accepted = accept4(fd, NULL, NULL, 0); |
274 | if (fd_accepted < 0) | |
08719b64 | 275 | return log_error_errno(errno, "Failed to accept connection on fd:%d: %m", fd); |
2ca0435b | 276 | |
eef0a274 LP |
277 | getsockname_pretty(fd_accepted, &local); |
278 | getpeername_pretty(fd_accepted, true, &peer); | |
30374ebe | 279 | log_info("Connection from %s to %s", strna(peer), strna(local)); |
2ca0435b | 280 | |
eef0a274 | 281 | return fork_and_exec_process(name, argv, envp, fd_accepted); |
2ca0435b ZJS |
282 | } |
283 | ||
284 | /* SIGCHLD handler. */ | |
5488e52d | 285 | static void sigchld_hdl(int sig) { |
9d458c09 LP |
286 | PROTECT_ERRNO; |
287 | ||
5488e52d EV |
288 | for (;;) { |
289 | siginfo_t si; | |
290 | int r; | |
08719b64 | 291 | |
5488e52d EV |
292 | si.si_pid = 0; |
293 | r = waitid(P_ALL, 0, &si, WEXITED|WNOHANG); | |
294 | if (r < 0) { | |
295 | if (errno != ECHILD) | |
296 | log_error_errno(errno, "Failed to reap children: %m"); | |
297 | return; | |
298 | } | |
299 | if (si.si_pid == 0) | |
300 | return; | |
301 | ||
302 | log_info("Child %d died with code %d", si.si_pid, si.si_status); | |
303 | } | |
2ca0435b ZJS |
304 | } |
305 | ||
306 | static int install_chld_handler(void) { | |
08719b64 | 307 | static const struct sigaction act = { |
e28c7cd0 | 308 | .sa_flags = SA_NOCLDSTOP|SA_RESTART, |
5488e52d | 309 | .sa_handler = sigchld_hdl, |
c0997164 | 310 | }; |
2ca0435b | 311 | |
b1c05b98 | 312 | if (sigaction(SIGCHLD, &act, 0) < 0) |
08719b64 LP |
313 | return log_error_errno(errno, "Failed to install SIGCHLD handler: %m"); |
314 | ||
315 | return 0; | |
2ca0435b ZJS |
316 | } |
317 | ||
601185b4 | 318 | static void help(void) { |
2ca0435b ZJS |
319 | printf("%s [OPTIONS...]\n\n" |
320 | "Listen on sockets and launch child on connection.\n\n" | |
321 | "Options:\n" | |
cf98937c ZJS |
322 | " -h --help Show this help and exit\n" |
323 | " --version Print version string and exit\n" | |
324 | " -l --listen=ADDR Listen for raw connections at ADDR\n" | |
325 | " -d --datagram Listen on datagram instead of stream socket\n" | |
326 | " --seqpacket Listen on SOCK_SEQPACKET instead of stream socket\n" | |
327 | " -a --accept Spawn separate child for each connection\n" | |
328 | " -E --setenv=NAME[=VALUE] Pass an environment variable to children\n" | |
329 | " --fdname=NAME[:NAME...] Specify names for file descriptors\n" | |
330 | " --inetd Enable inetd file descriptor passing protocol\n" | |
2ca0435b ZJS |
331 | "\n" |
332 | "Note: file descriptors from sd_listen_fds() will be passed through.\n" | |
601185b4 | 333 | , program_invocation_short_name); |
2ca0435b ZJS |
334 | } |
335 | ||
336 | static int parse_argv(int argc, char *argv[]) { | |
337 | enum { | |
338 | ARG_VERSION = 0x100, | |
8dd4c05b | 339 | ARG_FDNAME, |
d31e430f | 340 | ARG_SEQPACKET, |
eef0a274 | 341 | ARG_INETD, |
2ca0435b ZJS |
342 | }; |
343 | ||
344 | static const struct option options[] = { | |
892213bf ZJS |
345 | { "help", no_argument, NULL, 'h' }, |
346 | { "version", no_argument, NULL, ARG_VERSION }, | |
7b7afdfc | 347 | { "datagram", no_argument, NULL, 'd' }, |
d31e430f | 348 | { "seqpacket", no_argument, NULL, ARG_SEQPACKET }, |
892213bf ZJS |
349 | { "listen", required_argument, NULL, 'l' }, |
350 | { "accept", no_argument, NULL, 'a' }, | |
351 | { "setenv", required_argument, NULL, 'E' }, | |
8dd4c05b LP |
352 | { "environment", required_argument, NULL, 'E' }, /* legacy alias */ |
353 | { "fdname", required_argument, NULL, ARG_FDNAME }, | |
eef0a274 | 354 | { "inetd", no_argument, NULL, ARG_INETD }, |
eb9da376 | 355 | {} |
2ca0435b ZJS |
356 | }; |
357 | ||
8dd4c05b | 358 | int c, r; |
2ca0435b ZJS |
359 | |
360 | assert(argc >= 0); | |
361 | assert(argv); | |
362 | ||
b722348d | 363 | while ((c = getopt_long(argc, argv, "+hl:aE:d", options, NULL)) >= 0) |
2ca0435b ZJS |
364 | switch(c) { |
365 | case 'h': | |
601185b4 ZJS |
366 | help(); |
367 | return 0; | |
2ca0435b ZJS |
368 | |
369 | case ARG_VERSION: | |
3f6fd1ba | 370 | return version(); |
2ca0435b | 371 | |
8dd4c05b LP |
372 | case 'l': |
373 | r = strv_extend(&arg_listen, optarg); | |
2ca0435b | 374 | if (r < 0) |
8dd4c05b | 375 | return log_oom(); |
2ca0435b ZJS |
376 | |
377 | break; | |
2ca0435b | 378 | |
7b7afdfc | 379 | case 'd': |
d31e430f LP |
380 | if (arg_socket_type == SOCK_SEQPACKET) { |
381 | log_error("--datagram may not be combined with --seqpacket."); | |
382 | return -EINVAL; | |
383 | } | |
384 | ||
385 | arg_socket_type = SOCK_DGRAM; | |
386 | break; | |
387 | ||
388 | case ARG_SEQPACKET: | |
389 | if (arg_socket_type == SOCK_DGRAM) { | |
390 | log_error("--seqpacket may not be combined with --datagram."); | |
391 | return -EINVAL; | |
392 | } | |
393 | ||
394 | arg_socket_type = SOCK_SEQPACKET; | |
7b7afdfc SS |
395 | break; |
396 | ||
2ca0435b ZJS |
397 | case 'a': |
398 | arg_accept = true; | |
399 | break; | |
400 | ||
8dd4c05b LP |
401 | case 'E': |
402 | r = strv_extend(&arg_setenv, optarg); | |
5e65c93a | 403 | if (r < 0) |
8dd4c05b | 404 | return log_oom(); |
5e65c93a ZJS |
405 | |
406 | break; | |
8dd4c05b | 407 | |
cf98937c ZJS |
408 | case ARG_FDNAME: { |
409 | _cleanup_strv_free_ char **names; | |
410 | char **s; | |
411 | ||
412 | names = strv_split(optarg, ":"); | |
413 | if (!names) | |
414 | return log_oom(); | |
415 | ||
416 | STRV_FOREACH(s, names) | |
417 | if (!fdname_is_valid(*s)) { | |
418 | _cleanup_free_ char *esc; | |
163c76c9 | 419 | |
cf98937c ZJS |
420 | esc = cescape(*s); |
421 | log_warning("File descriptor name \"%s\" is not valid.", esc); | |
422 | } | |
423 | ||
424 | /* Empty optargs means one empty name */ | |
425 | r = strv_extend_strv(&arg_fdnames, | |
426 | strv_isempty(names) ? STRV_MAKE("") : names, | |
427 | false); | |
428 | if (r < 0) | |
429 | return log_error_errno(r, "strv_extend_strv: %m"); | |
8dd4c05b | 430 | break; |
cf98937c | 431 | } |
5e65c93a | 432 | |
eef0a274 LP |
433 | case ARG_INETD: |
434 | arg_inetd = true; | |
435 | break; | |
436 | ||
2ca0435b ZJS |
437 | case '?': |
438 | return -EINVAL; | |
439 | ||
440 | default: | |
eb9da376 | 441 | assert_not_reached("Unhandled option"); |
2ca0435b ZJS |
442 | } |
443 | ||
444 | if (optind == argc) { | |
601185b4 | 445 | log_error("%s: command to execute is missing.", |
2ca0435b ZJS |
446 | program_invocation_short_name); |
447 | return -EINVAL; | |
448 | } | |
449 | ||
d31e430f | 450 | if (arg_socket_type == SOCK_DGRAM && arg_accept) { |
7b7afdfc SS |
451 | log_error("Datagram sockets do not accept connections. " |
452 | "The --datagram and --accept options may not be combined."); | |
453 | return -EINVAL; | |
454 | } | |
455 | ||
2ca0435b ZJS |
456 | arg_args = argv + optind; |
457 | ||
458 | return 1 /* work to do */; | |
459 | } | |
460 | ||
461 | int main(int argc, char **argv, char **envp) { | |
462 | int r, n; | |
463 | int epoll_fd = -1; | |
464 | ||
2ca0435b | 465 | log_parse_environment(); |
eceb8483 | 466 | log_open(); |
2ca0435b ZJS |
467 | |
468 | r = parse_argv(argc, argv); | |
469 | if (r <= 0) | |
470 | return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE; | |
471 | ||
472 | r = install_chld_handler(); | |
473 | if (r < 0) | |
474 | return EXIT_FAILURE; | |
475 | ||
476 | n = open_sockets(&epoll_fd, arg_accept); | |
477 | if (n < 0) | |
478 | return EXIT_FAILURE; | |
2c408cb6 LP |
479 | if (n == 0) { |
480 | log_error("No sockets to listen on specified or passed in."); | |
481 | return EXIT_FAILURE; | |
482 | } | |
2ca0435b | 483 | |
eceb8483 | 484 | for (;;) { |
2ca0435b ZJS |
485 | struct epoll_event event; |
486 | ||
b1c05b98 | 487 | if (epoll_wait(epoll_fd, &event, 1, -1) < 0) { |
2ca0435b ZJS |
488 | if (errno == EINTR) |
489 | continue; | |
490 | ||
56f64d95 | 491 | log_error_errno(errno, "epoll_wait() failed: %m"); |
2ca0435b ZJS |
492 | return EXIT_FAILURE; |
493 | } | |
494 | ||
2c408cb6 | 495 | log_info("Communication attempt on fd %i.", event.data.fd); |
2ca0435b | 496 | if (arg_accept) { |
d31e430f | 497 | r = do_accept(argv[optind], argv + optind, envp, event.data.fd); |
2ca0435b ZJS |
498 | if (r < 0) |
499 | return EXIT_FAILURE; | |
500 | } else | |
501 | break; | |
502 | } | |
503 | ||
eef0a274 | 504 | exec_process(argv[optind], argv + optind, envp, SD_LISTEN_FDS_START, n); |
2ca0435b ZJS |
505 | |
506 | return EXIT_SUCCESS; | |
507 | } |