1 /*
2  * Copyright (c) 2010 - 2016 Reyk Floeter <reyk@openbsd.org>
3  * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 #include "got_compat.h"
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 
24 #include <fcntl.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28 #include <string.h>
29 #include <errno.h>
30 #include <signal.h>
31 #include <pwd.h>
32 #include <event.h>
33 
34 #include "proc.h"
35 
36 void	 proc_exec(struct privsep *, struct privsep_proc *, unsigned int,
37 	    int, char **);
38 void	 proc_setup(struct privsep *, struct privsep_proc *, unsigned int);
39 void	 proc_open(struct privsep *, int, int);
40 void	 proc_accept(struct privsep *, int, enum privsep_procid,
41 	    unsigned int);
42 void	 proc_close(struct privsep *);
43 void	 proc_shutdown(struct privsep_proc *);
44 void	 proc_sig_handler(int, short, void *);
45 int	 proc_dispatch_null(int, struct privsep_proc *, struct imsg *);
46 
47 enum privsep_procid privsep_process;
48 
49 enum privsep_procid
50 proc_getid(struct privsep_proc *procs, unsigned int nproc,
51     const char *proc_name)
52 {
53 	struct privsep_proc *p;
54 	unsigned int proc;
55 
56 	for (proc = 0; proc < nproc; proc++) {
57 		p = &procs[proc];
58 		if (strcmp(p->p_title, proc_name))
59 			continue;
60 
61 		return (p->p_id);
62 	}
63 
64 	return (PROC_MAX);
65 }
66 
67 void
68 proc_exec(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
69     int argc, char **argv)
70 {
71 	unsigned int proc, nargc, i, proc_i;
72 	char **nargv;
73 	struct privsep_proc *p;
74 	char num[32];
75 	int fd;
76 
77 	/* Prepare the new process argv. */
78 	nargv = calloc(argc + 5, sizeof(char *));
79 	if (nargv == NULL)
80 		fatal("%s: calloc", __func__);
81 
82 	/* Copy call argument first. */
83 	nargc = 0;
84 	nargv[nargc++] = argv[0];
85 
86 	/* Set process name argument and save the position. */
87 	nargv[nargc] = strdup("-P");
88 	if (nargv[nargc] == NULL)
89 		fatal("%s: strdup", __func__);
90 	nargc++;
91 	proc_i = nargc;
92 	nargc++;
93 
94 	/* Point process instance arg to stack and copy the original args. */
95 	nargv[nargc] = strdup("-I");
96 	if (nargv[nargc] == NULL)
97 		fatal("%s: strdup", __func__);
98 	nargc++;
99 	nargv[nargc++] = num;
100 	for (i = 1; i < (unsigned int) argc; i++)
101 		nargv[nargc++] = argv[i];
102 
103 	nargv[nargc] = NULL;
104 
105 	for (proc = 0; proc < nproc; proc++) {
106 		p = &procs[proc];
107 
108 		/* Update args with process title. */
109 		nargv[proc_i] = (char *)(uintptr_t)p->p_title;
110 
111 		/* Fire children processes. */
112 		for (i = 0; i < ps->ps_instances[p->p_id]; i++) {
113 			/* Update the process instance number. */
114 			snprintf(num, sizeof(num), "%u", i);
115 
116 			fd = ps->ps_pipes[p->p_id][i].pp_pipes[PROC_GOTWEBD][0];
117 			ps->ps_pipes[p->p_id][i].pp_pipes[PROC_GOTWEBD][0] = -1;
118 
119 			switch (fork()) {
120 			case -1:
121 				fatal("%s: fork", __func__);
122 				break;
123 			case 0:
124 				/* First create a new session */
125 				if (setsid() == -1)
126 					fatal("setsid");
127 
128 				/* Prepare parent socket. */
129 				if (fd != PROC_GOTWEBD_SOCK_FILENO) {
130 					if (dup2(fd, PROC_GOTWEBD_SOCK_FILENO)
131 					    == -1)
132 						fatal("dup2");
133 				} else if (fcntl(fd, F_SETFD, 0) == -1)
134 					fatal("fcntl");
135 
136 				execvp(argv[0], nargv);
137 				fatal("%s: execvp", __func__);
138 				break;
139 			default:
140 				/* Close child end. */
141 				close(fd);
142 				break;
143 			}
144 		}
145 	}
146 
147 	free(nargv);
148 }
149 
150 void
151 proc_connect(struct privsep *ps)
152 {
153 	struct imsgev *iev;
154 	unsigned int src, dst, inst;
155 
156 	/* Don't distribute any sockets if we are not really going to run. */
157 	if (ps->ps_noaction)
158 		return;
159 
160 	for (dst = 0; dst < PROC_MAX; dst++) {
161 		/* We don't communicate with ourselves. */
162 		if (dst == PROC_GOTWEBD)
163 			continue;
164 
165 		for (inst = 0; inst < ps->ps_instances[dst]; inst++) {
166 			iev = &ps->ps_ievs[dst][inst];
167 			imsg_init(&iev->ibuf, ps->ps_pp->pp_pipes[dst][inst]);
168 			event_set(&iev->ev, iev->ibuf.fd, iev->events,
169 			    iev->handler, iev->data);
170 			event_add(&iev->ev, NULL);
171 		}
172 	}
173 
174 	/* Distribute the socketpair()s for everyone. */
175 	for (src = 0; src < PROC_MAX; src++)
176 		for (dst = src; dst < PROC_MAX; dst++) {
177 			/* Parent already distributed its fds. */
178 			if (src == PROC_GOTWEBD || dst == PROC_GOTWEBD)
179 				continue;
180 
181 			proc_open(ps, src, dst);
182 		}
183 }
184 
185 void
186 proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
187     int argc, char **argv, enum privsep_procid proc_id)
188 {
189 	struct privsep_proc *p = NULL;
190 	struct privsep_pipes *pa, *pb;
191 	unsigned int proc;
192 	unsigned int dst;
193 	int fds[2];
194 
195 	/* Don't initiate anything if we are not really going to run. */
196 	if (ps->ps_noaction)
197 		return;
198 
199 	if (proc_id == PROC_GOTWEBD) {
200 		privsep_process = PROC_GOTWEBD;
201 		proc_setup(ps, procs, nproc);
202 
203 		/*
204 		 * Create the children sockets so we can use them
205 		 * to distribute the rest of the socketpair()s using
206 		 * proc_connect() later.
207 		 */
208 		for (dst = 0; dst < PROC_MAX; dst++) {
209 			/* Don't create socket for ourselves. */
210 			if (dst == PROC_GOTWEBD)
211 				continue;
212 
213 			for (proc = 0; proc < ps->ps_instances[dst]; proc++) {
214 				pa = &ps->ps_pipes[PROC_GOTWEBD][0];
215 				pb = &ps->ps_pipes[dst][proc];
216 				int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
217 #ifdef SOCK_CLOEXEC
218 				sock_flags |= SOCK_CLOEXEC;
219 #endif
220 				if (socketpair(AF_UNIX, sock_flags,
221 				    PF_UNSPEC, fds) == -1)
222 					fatal("%s: socketpair", __func__);
223 
224 				pa->pp_pipes[dst][proc] = fds[0];
225 				pb->pp_pipes[PROC_GOTWEBD][0] = fds[1];
226 			}
227 		}
228 
229 		/* Engage! */
230 		proc_exec(ps, procs, nproc, argc, argv);
231 		return;
232 	}
233 
234 	/* Initialize a child */
235 	for (proc = 0; proc < nproc; proc++) {
236 		if (procs[proc].p_id != proc_id)
237 			continue;
238 		p = &procs[proc];
239 		break;
240 	}
241 	if (p == NULL || p->p_init == NULL)
242 		fatalx("%s: process %d missing process initialization",
243 		    __func__, proc_id);
244 
245 	p->p_init(ps, p);
246 
247 	fatalx("failed to initiate child process");
248 }
249 
250 void
251 proc_accept(struct privsep *ps, int fd, enum privsep_procid dst,
252     unsigned int n)
253 {
254 	struct privsep_pipes *pp = ps->ps_pp;
255 	struct imsgev *iev;
256 
257 	if (ps->ps_ievs[dst] == NULL) {
258 #if DEBUG > 1
259 		log_debug("%s: %s src %d %d to dst %d %d not connected",
260 		    __func__, ps->ps_title[privsep_process],
261 		    privsep_process, ps->ps_instance + 1,
262 		    dst, n + 1);
263 #endif
264 		close(fd);
265 		return;
266 	}
267 
268 	if (pp->pp_pipes[dst][n] != -1) {
269 		log_warnx("%s: duplicated descriptor", __func__);
270 		close(fd);
271 		return;
272 	} else
273 		pp->pp_pipes[dst][n] = fd;
274 
275 	iev = &ps->ps_ievs[dst][n];
276 	imsg_init(&iev->ibuf, fd);
277 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
278 	event_add(&iev->ev, NULL);
279 }
280 
281 void
282 proc_setup(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc)
283 {
284 	unsigned int i, j, src, dst, id;
285 	struct privsep_pipes *pp;
286 
287 	/* Initialize parent title, ps_instances and procs. */
288 	ps->ps_title[PROC_GOTWEBD] = "parent";
289 
290 	for (src = 0; src < PROC_MAX; src++)
291 		/* Default to 1 process instance */
292 		if (ps->ps_instances[src] < 1)
293 			ps->ps_instances[src] = 1;
294 
295 	for (src = 0; src < nproc; src++) {
296 		procs[src].p_ps = ps;
297 		if (procs[src].p_cb == NULL)
298 			procs[src].p_cb = proc_dispatch_null;
299 
300 		id = procs[src].p_id;
301 		ps->ps_title[id] = procs[src].p_title;
302 		ps->ps_ievs[id] = calloc(ps->ps_instances[id],
303 		    sizeof(struct imsgev));
304 		if (ps->ps_ievs[id] == NULL)
305 			fatal("%s: calloc", __func__);
306 
307 		/* With this set up, we are ready to call imsg_init(). */
308 		for (i = 0; i < ps->ps_instances[id]; i++) {
309 			ps->ps_ievs[id][i].handler = proc_dispatch;
310 			ps->ps_ievs[id][i].events = EV_READ;
311 			ps->ps_ievs[id][i].proc = &procs[src];
312 			ps->ps_ievs[id][i].data = &ps->ps_ievs[id][i];
313 		}
314 	}
315 
316 	/*
317 	 * Allocate pipes for all process instances (incl. parent)
318 	 *
319 	 * - ps->ps_pipes: N:M mapping
320 	 * N source processes connected to M destination processes:
321 	 * [src][instances][dst][instances], for example
322 	 * [PROC_RELAY][3][PROC_CA][3]
323 	 *
324 	 * - ps->ps_pp: per-process 1:M part of ps->ps_pipes
325 	 * Each process instance has a destination array of socketpair fds:
326 	 * [dst][instances], for example
327 	 * [PROC_GOTWEBD][0]
328 	 */
329 	for (src = 0; src < PROC_MAX; src++) {
330 		/* Allocate destination array for each process */
331 		ps->ps_pipes[src] = calloc(ps->ps_instances[src],
332 		    sizeof(struct privsep_pipes));
333 		if (ps->ps_pipes[src] == NULL)
334 			fatal("%s: calloc", __func__);
335 
336 		for (i = 0; i < ps->ps_instances[src]; i++) {
337 			pp = &ps->ps_pipes[src][i];
338 
339 			for (dst = 0; dst < PROC_MAX; dst++) {
340 				/* Allocate maximum fd integers */
341 				pp->pp_pipes[dst] =
342 				    calloc(ps->ps_instances[dst],
343 				    sizeof(int));
344 				if (pp->pp_pipes[dst] == NULL)
345 					fatal("%s: calloc", __func__);
346 
347 				/* Mark fd as unused */
348 				for (j = 0; j < ps->ps_instances[dst]; j++)
349 					pp->pp_pipes[dst][j] = -1;
350 			}
351 		}
352 	}
353 
354 	ps->ps_pp = &ps->ps_pipes[privsep_process][ps->ps_instance];
355 }
356 
357 void
358 proc_kill(struct privsep *ps)
359 {
360 	char *cause;
361 	pid_t pid;
362 	int len, status;
363 
364 	if (privsep_process != PROC_GOTWEBD)
365 		return;
366 
367 	proc_close(ps);
368 
369 	do {
370 		pid = waitpid(WAIT_ANY, &status, 0);
371 		if (pid <= 0)
372 			continue;
373 
374 		if (WIFSIGNALED(status)) {
375 			len = asprintf(&cause, "terminated; signal %d",
376 			    WTERMSIG(status));
377 		} else if (WIFEXITED(status)) {
378 			if (WEXITSTATUS(status) != 0)
379 				len = asprintf(&cause, "exited abnormally");
380 			else
381 				len = 0;
382 		} else
383 			len = -1;
384 
385 		if (len == 0) {
386 			/* child exited OK, don't print a warning message */
387 		} else if (len != -1) {
388 			log_warnx("lost child: pid %u %s", pid, cause);
389 			free(cause);
390 		} else
391 			log_warnx("lost child: pid %u", pid);
392 	} while (pid != -1 || (pid == -1 && errno == EINTR));
393 }
394 
395 void
396 proc_open(struct privsep *ps, int src, int dst)
397 {
398 	struct privsep_pipes *pa, *pb;
399 	struct privsep_fd pf;
400 	int fds[2];
401 	unsigned int i, j;
402 
403 	/* Exchange pipes between process. */
404 	for (i = 0; i < ps->ps_instances[src]; i++) {
405 		for (j = 0; j < ps->ps_instances[dst]; j++) {
406 			/* Don't create sockets for ourself. */
407 			if (src == dst && i == j)
408 				continue;
409 
410 			pa = &ps->ps_pipes[src][i];
411 			pb = &ps->ps_pipes[dst][j];
412 			int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
413 #ifdef SOCK_CLOEXEC
414 			sock_flags |= SOCK_CLOEXEC;
415 #endif
416 			if (socketpair(AF_UNIX, sock_flags,
417 			    PF_UNSPEC, fds) == -1)
418 				fatal("%s: socketpair", __func__);
419 
420 			pa->pp_pipes[dst][j] = fds[0];
421 			pb->pp_pipes[src][i] = fds[1];
422 
423 			pf.pf_procid = src;
424 			pf.pf_instance = i;
425 			if (proc_compose_imsg(ps, dst, j, IMSG_CTL_PROCFD,
426 			    -1, pb->pp_pipes[src][i], &pf, sizeof(pf)) == -1)
427 				fatal("%s: proc_compose_imsg", __func__);
428 
429 			pf.pf_procid = dst;
430 			pf.pf_instance = j;
431 			if (proc_compose_imsg(ps, src, i, IMSG_CTL_PROCFD,
432 			    -1, pa->pp_pipes[dst][j], &pf, sizeof(pf)) == -1)
433 				fatal("%s: proc_compose_imsg", __func__);
434 
435 			/*
436 			 * We have to flush to send the descriptors and close
437 			 * them to avoid the fd ramp on startup.
438 			 */
439 			if (proc_flush_imsg(ps, src, i) == -1 ||
440 			    proc_flush_imsg(ps, dst, j) == -1)
441 				fatal("%s: imsg_flush", __func__);
442 		}
443 	}
444 }
445 
446 void
447 proc_close(struct privsep *ps)
448 {
449 	unsigned int dst, n;
450 	struct privsep_pipes *pp;
451 
452 	if (ps == NULL)
453 		return;
454 
455 	pp = ps->ps_pp;
456 
457 	for (dst = 0; dst < PROC_MAX; dst++) {
458 		if (ps->ps_ievs[dst] == NULL)
459 			continue;
460 
461 		for (n = 0; n < ps->ps_instances[dst]; n++) {
462 			if (pp->pp_pipes[dst][n] == -1)
463 				continue;
464 
465 			/* Cancel the fd, close and invalidate the fd */
466 			event_del(&(ps->ps_ievs[dst][n].ev));
467 			imsg_clear(&(ps->ps_ievs[dst][n].ibuf));
468 			close(pp->pp_pipes[dst][n]);
469 			pp->pp_pipes[dst][n] = -1;
470 		}
471 		free(ps->ps_ievs[dst]);
472 	}
473 }
474 
475 void
476 proc_shutdown(struct privsep_proc *p)
477 {
478 	struct privsep *ps = p->p_ps;
479 
480 	if (p->p_shutdown != NULL)
481 		(*p->p_shutdown)();
482 
483 	proc_close(ps);
484 
485 	log_info("%s, %s exiting, pid %d", getprogname(), p->p_title, getpid());
486 
487 	exit(0);
488 }
489 
490 void
491 proc_sig_handler(int sig, short event, void *arg)
492 {
493 	struct privsep_proc *p = arg;
494 
495 	switch (sig) {
496 	case SIGINT:
497 	case SIGTERM:
498 		proc_shutdown(p);
499 		break;
500 	case SIGCHLD:
501 	case SIGHUP:
502 	case SIGPIPE:
503 	case SIGUSR1:
504 		/* ignore */
505 		break;
506 	default:
507 		fatalx("proc_sig_handler: unexpected signal");
508 		/* NOTREACHED */
509 	}
510 }
511 
512 void
513 proc_run(struct privsep *ps, struct privsep_proc *p,
514     struct privsep_proc *procs, unsigned int nproc,
515     void (*run)(struct privsep *, struct privsep_proc *, void *), void *arg)
516 {
517 	struct passwd *pw;
518 	const char *root;
519 
520 	log_procinit(p->p_title);
521 
522 	/* Set the process group of the current process */
523 	setpgid(0, 0);
524 
525 	/* Use non-standard user */
526 	if (p->p_pw != NULL)
527 		pw = p->p_pw;
528 	else
529 		pw = ps->ps_pw;
530 
531 	/* Change root directory */
532 	if (p->p_chroot != NULL)
533 		root = p->p_chroot;
534 	else
535 		root = pw->pw_dir;
536 
537 	if (chroot(root) == -1)
538 		fatal("proc_run: chroot");
539 	if (chdir("/") == -1)
540 		fatal("proc_run: chdir(\"/\")");
541 
542 	privsep_process = p->p_id;
543 
544 	setproctitle("%s", p->p_title);
545 
546 	if (setgroups(1, &pw->pw_gid) ||
547 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
548 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
549 		fatal("proc_run: cannot drop privileges");
550 
551 	event_init();
552 
553 	signal_set(&ps->ps_evsigint, SIGINT, proc_sig_handler, p);
554 	signal_set(&ps->ps_evsigterm, SIGTERM, proc_sig_handler, p);
555 	signal_set(&ps->ps_evsigchld, SIGCHLD, proc_sig_handler, p);
556 	signal_set(&ps->ps_evsighup, SIGHUP, proc_sig_handler, p);
557 	signal_set(&ps->ps_evsigpipe, SIGPIPE, proc_sig_handler, p);
558 	signal_set(&ps->ps_evsigusr1, SIGUSR1, proc_sig_handler, p);
559 
560 	signal_add(&ps->ps_evsigint, NULL);
561 	signal_add(&ps->ps_evsigterm, NULL);
562 	signal_add(&ps->ps_evsigchld, NULL);
563 	signal_add(&ps->ps_evsighup, NULL);
564 	signal_add(&ps->ps_evsigpipe, NULL);
565 	signal_add(&ps->ps_evsigusr1, NULL);
566 
567 	proc_setup(ps, procs, nproc);
568 	proc_accept(ps, PROC_GOTWEBD_SOCK_FILENO, PROC_GOTWEBD, 0);
569 
570 	DPRINTF("%s: %s %d/%d, pid %d", __func__, p->p_title,
571 	    ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid());
572 
573 	if (run != NULL)
574 		run(ps, p, arg);
575 
576 	event_dispatch();
577 
578 	proc_shutdown(p);
579 }
580 
581 void
582 proc_dispatch(int fd, short event, void *arg)
583 {
584 	struct imsgev *iev = arg;
585 	struct privsep_proc *p = iev->proc;
586 	struct privsep *ps = p->p_ps;
587 	struct imsgbuf *ibuf;
588 	struct imsg imsg;
589 	ssize_t n;
590 	int verbose;
591 	const char *title;
592 	struct privsep_fd pf;
593 
594 	title = ps->ps_title[privsep_process];
595 	ibuf = &iev->ibuf;
596 
597 	if (event & EV_READ) {
598 		n = imsg_read(ibuf);
599 		if (n == -1 && errno != EAGAIN)
600 			fatal("%s: imsg_read", __func__);
601 		if (n == 0) {
602 			/* this pipe is dead, so remove the event handler */
603 			event_del(&iev->ev);
604 			event_loopexit(NULL);
605 			return;
606 		}
607 	}
608 
609 	if (event & EV_WRITE) {
610 		n = msgbuf_write(&ibuf->w);
611 		if (n == -1 && errno != EAGAIN)
612 			fatal("%s: msgbuf_write", __func__);
613 		if (n == 0) {
614 			/* this pipe is dead, so remove the event handler */
615 			event_del(&iev->ev);
616 			event_loopexit(NULL);
617 			return;
618 		}
619 	}
620 
621 	for (;;) {
622 		n = imsg_get(ibuf, &imsg);
623 		if (n == -1)
624 			fatal("%s: imsg_get", __func__);
625 		if (n == 0)
626 			break;
627 
628 #if DEBUG > 1
629 		log_debug("%s: %s %d got imsg %d peerid %d from %s %d",
630 		    __func__, title, ps->ps_instance + 1,
631 		    imsg.hdr.type, imsg.hdr.peerid, p->p_title, imsg.hdr.pid);
632 #endif
633 
634 		/*
635 		 * Check the message with the program callback
636 		 */
637 		if ((p->p_cb)(fd, p, &imsg) == 0) {
638 			/* Message was handled by the callback, continue */
639 			imsg_free(&imsg);
640 			continue;
641 		}
642 
643 		/*
644 		 * Generic message handling
645 		 */
646 		switch (imsg.hdr.type) {
647 		case IMSG_CTL_VERBOSE:
648 			log_info("%s", __func__);
649 			IMSG_SIZE_CHECK(&imsg, &verbose);
650 			memcpy(&verbose, imsg.data, sizeof(verbose));
651 			log_setverbose(verbose);
652 			break;
653 		case IMSG_CTL_PROCFD:
654 			IMSG_SIZE_CHECK(&imsg, &pf);
655 			memcpy(&pf, imsg.data, sizeof(pf));
656 			proc_accept(ps, imsg.fd, pf.pf_procid,
657 			    pf.pf_instance);
658 			break;
659 		default:
660 			log_warnx("%s: %s %d got invalid imsg %d peerid %d "
661 			    "from %s %d",
662 			    __func__, title, ps->ps_instance + 1,
663 			    imsg.hdr.type, imsg.hdr.peerid,
664 			    p->p_title, imsg.hdr.pid);
665 		}
666 		imsg_free(&imsg);
667 	}
668 	imsg_event_add(iev);
669 }
670 
671 int
672 proc_dispatch_null(int fd, struct privsep_proc *p, struct imsg *imsg)
673 {
674 	return (-1);
675 }
676 
677 /*
678  * imsg helper functions
679  */
680 
681 void
682 imsg_event_add(struct imsgev *iev)
683 {
684 	if (iev->handler == NULL) {
685 		imsg_flush(&iev->ibuf);
686 		return;
687 	}
688 
689 	iev->events = EV_READ;
690 	if (iev->ibuf.w.queued)
691 		iev->events |= EV_WRITE;
692 
693 	event_del(&iev->ev);
694 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
695 	event_add(&iev->ev, NULL);
696 }
697 
698 int
699 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
700     pid_t pid, int fd, void *data, uint16_t datalen)
701 {
702 	int ret;
703 
704 	ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data, datalen);
705 	if (ret == -1)
706 		return (ret);
707 	imsg_event_add(iev);
708 	return (ret);
709 }
710 
711 int
712 imsg_composev_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
713     pid_t pid, int fd, const struct iovec *iov, int iovcnt)
714 {
715 	int ret;
716 
717 	ret = imsg_composev(&iev->ibuf, type, peerid, pid, fd, iov, iovcnt);
718 	if (ret == -1)
719 		return (ret);
720 	imsg_event_add(iev);
721 	return (ret);
722 }
723 
724 void
725 proc_range(struct privsep *ps, enum privsep_procid id, int *n, int *m)
726 {
727 	if (*n == -1) {
728 		/* Use a range of all target instances */
729 		*n = 0;
730 		*m = ps->ps_instances[id];
731 	} else {
732 		/* Use only a single slot of the specified peer process */
733 		*m = *n + 1;
734 	}
735 }
736 
737 int
738 proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n,
739     uint16_t type, uint32_t peerid, int fd, void *data, uint16_t datalen)
740 {
741 	int m;
742 
743 	proc_range(ps, id, &n, &m);
744 	for (; n < m; n++) {
745 		if (imsg_compose_event(&ps->ps_ievs[id][n],
746 		    type, peerid, ps->ps_instance + 1, fd, data, datalen) == -1)
747 			return (-1);
748 	}
749 
750 	return (0);
751 }
752 
753 int
754 proc_compose(struct privsep *ps, enum privsep_procid id,
755     uint16_t type, void *data, uint16_t datalen)
756 {
757 	return (proc_compose_imsg(ps, id, -1, type, -1, -1, data, datalen));
758 }
759 
760 int
761 proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n,
762     uint16_t type, uint32_t peerid, int fd, const struct iovec *iov, int iovcnt)
763 {
764 	int m;
765 
766 	proc_range(ps, id, &n, &m);
767 	for (; n < m; n++)
768 		if (imsg_composev_event(&ps->ps_ievs[id][n],
769 		    type, peerid, ps->ps_instance + 1, fd, iov, iovcnt) == -1)
770 			return (-1);
771 
772 	return (0);
773 }
774 
775 int
776 proc_composev(struct privsep *ps, enum privsep_procid id,
777     uint16_t type, const struct iovec *iov, int iovcnt)
778 {
779 	return (proc_composev_imsg(ps, id, -1, type, -1, -1, iov, iovcnt));
780 }
781 
782 int
783 proc_forward_imsg(struct privsep *ps, struct imsg *imsg,
784     enum privsep_procid id, int n)
785 {
786 	return (proc_compose_imsg(ps, id, n, imsg->hdr.type,
787 	    imsg->hdr.peerid, imsg->fd, imsg->data, IMSG_DATA_SIZE(imsg)));
788 }
789 
790 struct imsgbuf *
791 proc_ibuf(struct privsep *ps, enum privsep_procid id, int n)
792 {
793 	int m;
794 
795 	proc_range(ps, id, &n, &m);
796 	return (&ps->ps_ievs[id][n].ibuf);
797 }
798 
799 struct imsgev *
800 proc_iev(struct privsep *ps, enum privsep_procid id, int n)
801 {
802 	int m;
803 
804 	proc_range(ps, id, &n, &m);
805 	return (&ps->ps_ievs[id][n]);
806 }
807 
808 /* This function should only be called with care as it breaks async I/O */
809 int
810 proc_flush_imsg(struct privsep *ps, enum privsep_procid id, int n)
811 {
812 	struct imsgbuf *ibuf;
813 	int m, ret = 0;
814 
815 	proc_range(ps, id, &n, &m);
816 	for (; n < m; n++) {
817 		ibuf = proc_ibuf(ps, id, n);
818 		if (ibuf == NULL)
819 			return (-1);
820 		do {
821 			ret = imsg_flush(ibuf);
822 		} while (ret == -1 && errno == EAGAIN);
823 		if (ret == -1)
824 			break;
825 		imsg_event_add(&ps->ps_ievs[id][n]);
826 	}
827 
828 	return (ret);
829 }