Gotweb

Blob

Date:: Fri Mar 22 10:17:03 2024 UTC
Message:: display process title in syslog when a gotd child process exits
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2024 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/types.h>
18 #include <sys/queue.h>
19 #include <sys/tree.h>
20 #include <sys/socket.h>
21 #include <sys/wait.h>
22 
23 #include <errno.h>
24 #include <event.h>
25 #include <siphash.h>
26 #include <limits.h>
27 #include <sha1.h>
28 #include <sha2.h>
29 #include <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <imsg.h>
34 #include <unistd.h>
35 
36 #include "got_error.h"
37 #include "got_path.h"
38 
39 #include "gotd.h"
40 #include "log.h"
41 #include "notify.h"
42 
43 #ifndef nitems
44 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
45 #endif
46 
47 static struct gotd_notify {
48 	pid_t pid;
49 	const char *title;
50 	struct gotd_imsgev parent_iev;
51 	struct gotd_repolist *repos;
52 	const char *default_sender;
53 } gotd_notify;
54 
55 struct gotd_notify_session {
56 	STAILQ_ENTRY(gotd_notify_session) entry;
57 	uint32_t id;
58 	struct gotd_imsgev iev;
59 };
60 STAILQ_HEAD(gotd_notify_sessions, gotd_notify_session);
61 
62 static struct gotd_notify_sessions gotd_notify_sessions[GOTD_CLIENT_TABLE_SIZE];
63 static SIPHASH_KEY sessions_hash_key;
64 
65 static void gotd_notify_shutdown(void);
66 
67 static uint64_t
68 session_hash(uint32_t session_id)
69 {
70 	return SipHash24(&sessions_hash_key, &session_id, sizeof(session_id));
71 }
72 
73 static void
74 add_session(struct gotd_notify_session *session)
75 {
76 	uint64_t slot;
77 
78 	slot = session_hash(session->id) % nitems(gotd_notify_sessions);
79 	STAILQ_INSERT_HEAD(&gotd_notify_sessions[slot], session, entry);
80 }
81 
82 static struct gotd_notify_session *
83 find_session(uint32_t session_id)
84 {
85 	uint64_t slot;
86 	struct gotd_notify_session *s;
87 
88 	slot = session_hash(session_id) % nitems(gotd_notify_sessions);
89 	STAILQ_FOREACH(s, &gotd_notify_sessions[slot], entry) {
90 		if (s->id == session_id)
91 			return s;
92 	}
93 
94 	return NULL;
95 }
96 
97 static struct gotd_notify_session *
98 find_session_by_fd(int fd)
99 {
100 	uint64_t slot;
101 	struct gotd_notify_session *s;
102 
103 	for (slot = 0; slot < nitems(gotd_notify_sessions); slot++) {
104 		STAILQ_FOREACH(s, &gotd_notify_sessions[slot], entry) {
105 			if (s->iev.ibuf.fd == fd)
106 				return s;
107 		}
108 
109 	}
110 
111 	return NULL;
112 }
113 
114 
115 static void
116 remove_session(struct gotd_notify_session *session)
117 {
118 	uint64_t slot;
119 
120 	slot = session_hash(session->id) % nitems(gotd_notify_sessions);
121 	STAILQ_REMOVE(&gotd_notify_sessions[slot], session,
122 	    gotd_notify_session, entry);
123 	free(session);
124 }
125 
126 static uint32_t
127 get_session_id(void)
128 {
129 	int duplicate = 0;
130 	uint32_t id;
131 
132 	do {
133 		id = arc4random();
134 		duplicate = (find_session(id) != NULL);
135 	} while (duplicate || id == 0);
136 
137 	return id;
138 }
139 
140 static void
141 gotd_notify_sighdlr(int sig, short event, void *arg)
142 {
143 	/*
144 	 * Normal signal handler rules don't apply because libevent
145 	 * decouples for us.
146 	 */
147 
148 	switch (sig) {
149 	case SIGHUP:
150 		log_info("%s: ignoring SIGHUP", __func__);
151 		break;
152 	case SIGUSR1:
153 		log_info("%s: ignoring SIGUSR1", __func__);
154 		break;
155 	case SIGTERM:
156 	case SIGINT:
157 		gotd_notify_shutdown();
158 		/* NOTREACHED */
159 		break;
160 	default:
161 		fatalx("unexpected signal");
162 	}
163 }
164 
165 static void
166 run_notification_helper(const char *prog, const char **argv, int fd)
167 {
168 	const struct got_error *err = NULL;
169 	pid_t pid;
170 	int child_status;
171 
172 	pid = fork();
173 	if (pid == -1) {
174 		err = got_error_from_errno("fork");
175 		log_warn("%s", err->msg);
176 		return;
177 	} else if (pid == 0) {
178 		signal(SIGQUIT, SIG_DFL);
179 		signal(SIGINT, SIG_DFL);
180 		signal(SIGCHLD, SIG_DFL);
181 
182 		if (dup2(fd, STDIN_FILENO) == -1) {
183 			fprintf(stderr, "%s: dup2: %s\n", getprogname(),
184 			    strerror(errno));
185 			_exit(1);
186 		}
187 
188 		closefrom(STDERR_FILENO + 1);
189 
190 		if (execv(prog, (char *const *)argv) == -1) {
191 			fprintf(stderr, "%s: exec %s: %s\n", getprogname(),
192 			    prog, strerror(errno));
193 			_exit(1);
194 		}
195 
196 		/* not reached */
197 	}
198 
199 	if (waitpid(pid, &child_status, 0) == -1) {
200 		err = got_error_from_errno("waitpid");
201 		goto done;
202 	}
203 
204 	if (!WIFEXITED(child_status)) {
205 		err = got_error(GOT_ERR_PRIVSEP_DIED);
206 		goto done;
207 	}
208 
209 	if (WEXITSTATUS(child_status) != 0)
210 		err = got_error(GOT_ERR_PRIVSEP_EXIT);
211 done:
212 	if (err)
213 		log_warnx("%s: child %s pid %d: %s", gotd_notify.title,
214 		    prog, pid, err->msg);
215 }
216 
217 static void
218 notify_email(struct gotd_notification_target *target, const char *subject_line,
219     int fd)
220 {
221 	const char *argv[13];
222 	int i = 0;
223 
224 	argv[i++] = GOTD_PATH_PROG_NOTIFY_EMAIL;
225 
226 	argv[i++] = "-f";
227 	if (target->conf.email.sender)
228 		argv[i++] = target->conf.email.sender;
229 	else
230 		argv[i++] = gotd_notify.default_sender;
231 
232 	if (target->conf.email.responder) {
233 		argv[i++] = "-r";
234 		argv[i++] = target->conf.email.responder;
235 	}
236 
237 	if (target->conf.email.hostname) {
238 		argv[i++] = "-h";
239 		argv[i++] = target->conf.email.hostname;
240 	}
241 	
242 	if (target->conf.email.port) {
243 		argv[i++] = "-p";
244 		argv[i++] = target->conf.email.port;
245 	}
246 
247 	argv[i++] = "-s";
248 	argv[i++] = subject_line;
249 
250 	argv[i++] = target->conf.email.recipient;
251 
252 	argv[i] = NULL;
253 
254 	run_notification_helper(GOTD_PATH_PROG_NOTIFY_EMAIL, argv, fd);
255 }
256 
257 static void
258 notify_http(struct gotd_notification_target *target, const char *subject_line,
259     int fd)
260 {
261 	const char *argv[10] = { 0 }; /* TODO */
262 
263 	run_notification_helper(GOTD_PATH_PROG_NOTIFY_HTTP, argv, fd);
264 }
265 
266 static const struct got_error *
267 send_notification(struct imsg *imsg, struct gotd_imsgev *iev)
268 {
269 	const struct got_error *err = NULL;
270 	struct gotd_imsg_notify inotify;
271 	size_t datalen;
272 	struct gotd_repo *repo;
273 	struct gotd_notification_target *target;
274 	int fd;
275 
276 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
277 	if (datalen != sizeof(inotify))
278 		return got_error(GOT_ERR_PRIVSEP_LEN);
279 
280 	memcpy(&inotify, imsg->data, datalen);
281 
282 	repo = gotd_find_repo_by_name(inotify.repo_name, gotd_notify.repos);
283 	if (repo == NULL)
284 		return got_error(GOT_ERR_PRIVSEP_MSG);
285 
286 	fd = imsg_get_fd(imsg);
287 	if (fd == -1)
288 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
289 
290 	if (lseek(fd, 0, SEEK_SET) == -1) {
291 		err = got_error_from_errno("lseek");
292 		goto done;
293 	}
294 
295 	STAILQ_FOREACH(target, &repo->notification_targets, entry) {
296 		switch (target->type) {
297 		case GOTD_NOTIFICATION_VIA_EMAIL:
298 			notify_email(target, inotify.subject_line, fd);
299 			break;
300 		case GOTD_NOTIFICATION_VIA_HTTP:
301 			notify_http(target, inotify.subject_line, fd);
302 			break;
303 		}
304 	}
305 
306 	if (gotd_imsg_compose_event(iev, GOTD_IMSG_NOTIFICATION_SENT,
307 	    PROC_NOTIFY, -1, NULL, 0) == -1) {
308 		err = got_error_from_errno("imsg compose NOTIFY");
309 		goto done;
310 	}
311 done:
312 	close(fd);
313 	return err;
314 }
315 
316 static void
317 notify_dispatch_session(int fd, short event, void *arg)
318 {
319 	struct gotd_imsgev *iev = arg;
320 	struct imsgbuf *ibuf = &iev->ibuf;
321 	ssize_t n;
322 	int shut = 0;
323 	struct imsg imsg;
324 
325 	if (event & EV_READ) {
326 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
327 			fatal("imsg_read error");
328 		if (n == 0) {
329 			/* Connection closed. */
330 			shut = 1;
331 			goto done;
332 		}
333 	}
334 
335 	if (event & EV_WRITE) {
336 		n = msgbuf_write(&ibuf->w);
337 		if (n == -1 && errno != EAGAIN)
338 			fatal("msgbuf_write");
339 		if (n == 0) {
340 			/* Connection closed. */
341 			shut = 1;
342 			goto done;
343 		}
344 	}
345 
346 	for (;;) {
347 		const struct got_error *err = NULL;
348 
349 		if ((n = imsg_get(ibuf, &imsg)) == -1)
350 			fatal("%s: imsg_get error", __func__);
351 		if (n == 0)	/* No more messages. */
352 			break;
353 
354 		switch (imsg.hdr.type) {
355 		case GOTD_IMSG_NOTIFY:
356 			err = send_notification(&imsg, iev);
357 			break;
358 		default:
359 			log_debug("unexpected imsg %d", imsg.hdr.type);
360 			break;
361 		}
362 		imsg_free(&imsg);
363 
364 		if (err)
365 			log_warnx("%s: %s", __func__, err->msg);
366 	}
367 done:
368 	if (!shut) {
369 		gotd_imsg_event_add(iev);
370 	} else {
371 		struct gotd_notify_session *session;
372 
373 		/* This pipe is dead. Remove its event handler */
374 		event_del(&iev->ev);
375 		imsg_clear(&iev->ibuf);
376 
377 		session = find_session_by_fd(fd);
378 		if (session)
379 			remove_session(session);
380 	}
381 }
382 
383 static const struct got_error *
384 recv_session(struct imsg *imsg)
385 {
386 	struct gotd_notify_session *session;
387 	size_t datalen;
388 	int fd;
389 
390 	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
391 	if (datalen != 0)
392 		return got_error(GOT_ERR_PRIVSEP_LEN);
393 
394 	fd = imsg_get_fd(imsg);
395 	if (fd == -1)
396 		return got_error(GOT_ERR_PRIVSEP_NO_FD);
397 
398 	session = calloc(1, sizeof(*session));
399 	if (session == NULL)
400 		return got_error_from_errno("calloc");
401 
402 	session->id = get_session_id();
403 	imsg_init(&session->iev.ibuf, fd);
404 	session->iev.handler = notify_dispatch_session;
405 	session->iev.events = EV_READ;
406 	session->iev.handler_arg = NULL;
407 	event_set(&session->iev.ev, session->iev.ibuf.fd, EV_READ,
408 	    notify_dispatch_session, &session->iev);
409 	gotd_imsg_event_add(&session->iev);
410 	add_session(session);
411 
412 	return NULL;
413 }
414 
415 static void
416 notify_dispatch(int fd, short event, void *arg)
417 {
418 	struct gotd_imsgev *iev = arg;
419 	struct imsgbuf *ibuf = &iev->ibuf;
420 	ssize_t n;
421 	int shut = 0;
422 	struct imsg imsg;
423 
424 	if (event & EV_READ) {
425 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
426 			fatal("imsg_read error");
427 		if (n == 0) {
428 			/* Connection closed. */
429 			shut = 1;
430 			goto done;
431 		}
432 	}
433 
434 	if (event & EV_WRITE) {
435 		n = msgbuf_write(&ibuf->w);
436 		if (n == -1 && errno != EAGAIN)
437 			fatal("msgbuf_write");
438 		if (n == 0) {
439 			/* Connection closed. */
440 			shut = 1;
441 			goto done;
442 		}
443 	}
444 
445 	for (;;) {
446 		const struct got_error *err = NULL;
447 
448 		if ((n = imsg_get(ibuf, &imsg)) == -1)
449 			fatal("%s: imsg_get error", __func__);
450 		if (n == 0)	/* No more messages. */
451 			break;
452 
453 		switch (imsg.hdr.type) {
454 		case GOTD_IMSG_CONNECT_SESSION:
455 			err = recv_session(&imsg);
456 			break;
457 		default:
458 			log_debug("unexpected imsg %d", imsg.hdr.type);
459 			break;
460 		}
461 		imsg_free(&imsg);
462 
463 		if (err)
464 			log_warnx("%s: %s", __func__, err->msg);
465 	}
466 done:
467 	if (!shut) {
468 		gotd_imsg_event_add(iev);
469 	} else {
470 		/* This pipe is dead. Remove its event handler */
471 		event_del(&iev->ev);
472 		event_loopexit(NULL);
473 	}
474 
475 }
476 
477 void
478 notify_main(const char *title, struct gotd_repolist *repos,
479     const char *default_sender)
480 {
481 	const struct got_error *err = NULL;
482 	struct event evsigint, evsigterm, evsighup, evsigusr1;
483 
484 	arc4random_buf(&sessions_hash_key, sizeof(sessions_hash_key));
485 
486 	gotd_notify.title = title;
487 	gotd_notify.repos = repos;
488 	gotd_notify.default_sender = default_sender;
489 	gotd_notify.pid = getpid();
490 
491 	signal_set(&evsigint, SIGINT, gotd_notify_sighdlr, NULL);
492 	signal_set(&evsigterm, SIGTERM, gotd_notify_sighdlr, NULL);
493 	signal_set(&evsighup, SIGHUP, gotd_notify_sighdlr, NULL);
494 	signal_set(&evsigusr1, SIGUSR1, gotd_notify_sighdlr, NULL);
495 	signal(SIGPIPE, SIG_IGN);
496 
497 	signal_add(&evsigint, NULL);
498 	signal_add(&evsigterm, NULL);
499 	signal_add(&evsighup, NULL);
500 	signal_add(&evsigusr1, NULL);
501 
502 	imsg_init(&gotd_notify.parent_iev.ibuf, GOTD_FILENO_MSG_PIPE);
503 	gotd_notify.parent_iev.handler = notify_dispatch;
504 	gotd_notify.parent_iev.events = EV_READ;
505 	gotd_notify.parent_iev.handler_arg = NULL;
506 	event_set(&gotd_notify.parent_iev.ev, gotd_notify.parent_iev.ibuf.fd,
507 	    EV_READ, notify_dispatch, &gotd_notify.parent_iev);
508 	gotd_imsg_event_add(&gotd_notify.parent_iev);
509 
510 	event_dispatch();
511 
512 	if (err)
513 		log_warnx("%s: %s", title, err->msg);
514 	gotd_notify_shutdown();
515 }
516 
517 void
518 gotd_notify_shutdown(void)
519 {
520 	log_debug("%s: shutting down", gotd_notify.title);
521 	exit(0);
522 }