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Date:: Tue Aug 30 18:37:47 2022 UTC
Message:: remove trailing whitespace; patch by Josiah Frentsos
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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 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/socket.h>
21 #include <sys/wait.h>
22 
23 #include <fcntl.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <unistd.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <signal.h>
30 #include <pwd.h>
31 #include <event.h>
32 
33 #include "proc.h"
34 
35 #include "got_compat.h"
36 
37 void	 proc_exec(struct privsep *, struct privsep_proc *, unsigned int,
38 	    int, char **);
39 void	 proc_setup(struct privsep *, struct privsep_proc *, unsigned int);
40 void	 proc_open(struct privsep *, int, int);
41 void	 proc_accept(struct privsep *, int, enum privsep_procid,
42 	    unsigned int);
43 void	 proc_close(struct privsep *);
44 int	 proc_ispeer(struct privsep_proc *, unsigned int, enum privsep_procid);
45 void	 proc_shutdown(struct privsep_proc *);
46 void	 proc_sig_handler(int, short, void *);
47 int	 proc_dispatch_null(int, struct privsep_proc *, struct imsg *);
48 
49 enum privsep_procid privsep_process;
50 
51 int
52 proc_ispeer(struct privsep_proc *procs, unsigned int nproc,
53     enum privsep_procid type)
54 {
55 	unsigned int i;
56 
57 	for (i = 0; i < nproc; i++)
58 		if (procs[i].p_id == type)
59 			return (1);
60 
61 	return (0);
62 }
63 
64 enum privsep_procid
65 proc_getid(struct privsep_proc *procs, unsigned int nproc,
66     const char *proc_name)
67 {
68 	struct privsep_proc *p;
69 	unsigned int proc;
70 
71 	for (proc = 0; proc < nproc; proc++) {
72 		p = &procs[proc];
73 		if (strcmp(p->p_title, proc_name))
74 			continue;
75 
76 		return (p->p_id);
77 	}
78 
79 	return (PROC_MAX);
80 }
81 
82 void
83 proc_exec(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
84     int argc, char **argv)
85 {
86 	unsigned int proc, nargc, i, proc_i;
87 	char **nargv;
88 	struct privsep_proc *p;
89 	char num[32];
90 	int fd;
91 
92 	/* Prepare the new process argv. */
93 	nargv = calloc(argc + 5, sizeof(char *));
94 	if (nargv == NULL)
95 		fatal("%s: calloc", __func__);
96 
97 	/* Copy call argument first. */
98 	nargc = 0;
99 	nargv[nargc++] = argv[0];
100 
101 	/* Set process name argument and save the position. */
102 	nargv[nargc] = strdup("-P");
103 	if (nargv[nargc] == NULL)
104 		fatal("%s: strdup", __func__);
105 	nargc++;
106 	proc_i = nargc;
107 	nargc++;
108 
109 	/* Point process instance arg to stack and copy the original args. */
110 	nargv[nargc] = strdup("-I");
111 	if (nargv[nargc] == NULL)
112 		fatal("%s: strdup", __func__);
113 	nargc++;
114 	nargv[nargc++] = num;
115 	for (i = 1; i < (unsigned int) argc; i++)
116 		nargv[nargc++] = argv[i];
117 
118 	nargv[nargc] = NULL;
119 
120 	for (proc = 0; proc < nproc; proc++) {
121 		p = &procs[proc];
122 
123 		/* Update args with process title. */
124 		nargv[proc_i] = (char *)(uintptr_t)p->p_title;
125 
126 		/* Fire children processes. */
127 		for (i = 0; i < ps->ps_instances[p->p_id]; i++) {
128 			/* Update the process instance number. */
129 			snprintf(num, sizeof(num), "%u", i);
130 
131 			fd = ps->ps_pipes[p->p_id][i].pp_pipes[PROC_GOTWEBD][0];
132 			ps->ps_pipes[p->p_id][i].pp_pipes[PROC_GOTWEBD][0] = -1;
133 
134 			switch (fork()) {
135 			case -1:
136 				fatal("%s: fork", __func__);
137 				break;
138 			case 0:
139 				/* First create a new session */
140 				if (setsid() == -1)
141 					fatal("setsid");
142 
143 				/* Prepare parent socket. */
144 				if (fd != PROC_GOTWEBD_SOCK_FILENO) {
145 					if (dup2(fd, PROC_GOTWEBD_SOCK_FILENO)
146 					    == -1)
147 						fatal("dup2");
148 				} else if (fcntl(fd, F_SETFD, 0) == -1)
149 					fatal("fcntl");
150 
151 				execvp(argv[0], nargv);
152 				fatal("%s: execvp", __func__);
153 				break;
154 			default:
155 				/* Close child end. */
156 				close(fd);
157 				break;
158 			}
159 		}
160 	}
161 
162 	free(nargv);
163 }
164 
165 void
166 proc_connect(struct privsep *ps)
167 {
168 	struct imsgev *iev;
169 	unsigned int src, dst, inst;
170 
171 	/* Don't distribute any sockets if we are not really going to run. */
172 	if (ps->ps_noaction)
173 		return;
174 
175 	for (dst = 0; dst < PROC_MAX; dst++) {
176 		/* We don't communicate with ourselves. */
177 		if (dst == PROC_GOTWEBD)
178 			continue;
179 
180 		for (inst = 0; inst < ps->ps_instances[dst]; inst++) {
181 			iev = &ps->ps_ievs[dst][inst];
182 			imsg_init(&iev->ibuf, ps->ps_pp->pp_pipes[dst][inst]);
183 			event_set(&iev->ev, iev->ibuf.fd, iev->events,
184 			    iev->handler, iev->data);
185 			event_add(&iev->ev, NULL);
186 		}
187 	}
188 
189 	/* Distribute the socketpair()s for everyone. */
190 	for (src = 0; src < PROC_MAX; src++)
191 		for (dst = src; dst < PROC_MAX; dst++) {
192 			/* Parent already distributed its fds. */
193 			if (src == PROC_GOTWEBD || dst == PROC_GOTWEBD)
194 				continue;
195 
196 			proc_open(ps, src, dst);
197 		}
198 }
199 
200 void
201 proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
202     int argc, char **argv, enum privsep_procid proc_id)
203 {
204 	struct privsep_proc *p = NULL;
205 	struct privsep_pipes *pa, *pb;
206 	unsigned int proc;
207 	unsigned int dst;
208 	int fds[2];
209 
210 	/* Don't initiate anything if we are not really going to run. */
211 	if (ps->ps_noaction)
212 		return;
213 
214 	if (proc_id == PROC_GOTWEBD) {
215 		privsep_process = PROC_GOTWEBD;
216 		proc_setup(ps, procs, nproc);
217 
218 		/*
219 		 * Create the children sockets so we can use them
220 		 * to distribute the rest of the socketpair()s using
221 		 * proc_connect() later.
222 		 */
223 		for (dst = 0; dst < PROC_MAX; dst++) {
224 			/* Don't create socket for ourselves. */
225 			if (dst == PROC_GOTWEBD)
226 				continue;
227 
228 			for (proc = 0; proc < ps->ps_instances[dst]; proc++) {
229 				pa = &ps->ps_pipes[PROC_GOTWEBD][0];
230 				pb = &ps->ps_pipes[dst][proc];
231 				int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
232 #ifdef SOCK_CLOEXEC
233 				sock_flags |= SOCK_CLOEXEC;
234 #endif
235 				if (socketpair(AF_UNIX, sock_flags,
236 				    PF_UNSPEC, fds) == -1)
237 					fatal("%s: socketpair", __func__);
238 
239 				pa->pp_pipes[dst][proc] = fds[0];
240 				pb->pp_pipes[PROC_GOTWEBD][0] = fds[1];
241 			}
242 		}
243 
244 		/* Engage! */
245 		proc_exec(ps, procs, nproc, argc, argv);
246 		return;
247 	}
248 
249 	/* Initialize a child */
250 	for (proc = 0; proc < nproc; proc++) {
251 		if (procs[proc].p_id != proc_id)
252 			continue;
253 		p = &procs[proc];
254 		break;
255 	}
256 	if (p == NULL || p->p_init == NULL)
257 		fatalx("%s: process %d missing process initialization",
258 		    __func__, proc_id);
259 
260 	p->p_init(ps, p);
261 
262 	fatalx("failed to initiate child process");
263 }
264 
265 void
266 proc_accept(struct privsep *ps, int fd, enum privsep_procid dst,
267     unsigned int n)
268 {
269 	struct privsep_pipes *pp = ps->ps_pp;
270 	struct imsgev *iev;
271 
272 	if (ps->ps_ievs[dst] == NULL) {
273 #if DEBUG > 1
274 		log_debug("%s: %s src %d %d to dst %d %d not connected",
275 		    __func__, ps->ps_title[privsep_process],
276 		    privsep_process, ps->ps_instance + 1,
277 		    dst, n + 1);
278 #endif
279 		close(fd);
280 		return;
281 	}
282 
283 	if (pp->pp_pipes[dst][n] != -1) {
284 		log_warnx("%s: duplicated descriptor", __func__);
285 		close(fd);
286 		return;
287 	} else
288 		pp->pp_pipes[dst][n] = fd;
289 
290 	iev = &ps->ps_ievs[dst][n];
291 	imsg_init(&iev->ibuf, fd);
292 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
293 	event_add(&iev->ev, NULL);
294 }
295 
296 void
297 proc_setup(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc)
298 {
299 	unsigned int i, j, src, dst, id;
300 	struct privsep_pipes *pp;
301 
302 	/* Initialize parent title, ps_instances and procs. */
303 	ps->ps_title[PROC_GOTWEBD] = "parent";
304 
305 	for (src = 0; src < PROC_MAX; src++)
306 		/* Default to 1 process instance */
307 		if (ps->ps_instances[src] < 1)
308 			ps->ps_instances[src] = 1;
309 
310 	for (src = 0; src < nproc; src++) {
311 		procs[src].p_ps = ps;
312 		if (procs[src].p_cb == NULL)
313 			procs[src].p_cb = proc_dispatch_null;
314 
315 		id = procs[src].p_id;
316 		ps->ps_title[id] = procs[src].p_title;
317 		ps->ps_ievs[id] = calloc(ps->ps_instances[id],
318 		    sizeof(struct imsgev));
319 		if (ps->ps_ievs[id] == NULL)
320 			fatal("%s: calloc", __func__);
321 
322 		/* With this set up, we are ready to call imsg_init(). */
323 		for (i = 0; i < ps->ps_instances[id]; i++) {
324 			ps->ps_ievs[id][i].handler = proc_dispatch;
325 			ps->ps_ievs[id][i].events = EV_READ;
326 			ps->ps_ievs[id][i].proc = &procs[src];
327 			ps->ps_ievs[id][i].data = &ps->ps_ievs[id][i];
328 		}
329 	}
330 
331 	/*
332 	 * Allocate pipes for all process instances (incl. parent)
333 	 *
334 	 * - ps->ps_pipes: N:M mapping
335 	 * N source processes connected to M destination processes:
336 	 * [src][instances][dst][instances], for example
337 	 * [PROC_RELAY][3][PROC_CA][3]
338 	 *
339 	 * - ps->ps_pp: per-process 1:M part of ps->ps_pipes
340 	 * Each process instance has a destination array of socketpair fds:
341 	 * [dst][instances], for example
342 	 * [PROC_GOTWEBD][0]
343 	 */
344 	for (src = 0; src < PROC_MAX; src++) {
345 		/* Allocate destination array for each process */
346 		ps->ps_pipes[src] = calloc(ps->ps_instances[src],
347 		    sizeof(struct privsep_pipes));
348 		if (ps->ps_pipes[src] == NULL)
349 			fatal("%s: calloc", __func__);
350 
351 		for (i = 0; i < ps->ps_instances[src]; i++) {
352 			pp = &ps->ps_pipes[src][i];
353 
354 			for (dst = 0; dst < PROC_MAX; dst++) {
355 				/* Allocate maximum fd integers */
356 				pp->pp_pipes[dst] =
357 				    calloc(ps->ps_instances[dst],
358 				    sizeof(int));
359 				if (pp->pp_pipes[dst] == NULL)
360 					fatal("%s: calloc", __func__);
361 
362 				/* Mark fd as unused */
363 				for (j = 0; j < ps->ps_instances[dst]; j++)
364 					pp->pp_pipes[dst][j] = -1;
365 			}
366 		}
367 	}
368 
369 	ps->ps_pp = &ps->ps_pipes[privsep_process][ps->ps_instance];
370 }
371 
372 void
373 proc_kill(struct privsep *ps)
374 {
375 	char *cause;
376 	pid_t pid;
377 	int len, status;
378 
379 	if (privsep_process != PROC_GOTWEBD)
380 		return;
381 
382 	proc_close(ps);
383 
384 	do {
385 		pid = waitpid(WAIT_ANY, &status, 0);
386 		if (pid <= 0)
387 			continue;
388 
389 		if (WIFSIGNALED(status)) {
390 			len = asprintf(&cause, "terminated; signal %d",
391 			    WTERMSIG(status));
392 		} else if (WIFEXITED(status)) {
393 			if (WEXITSTATUS(status) != 0)
394 				len = asprintf(&cause, "exited abnormally");
395 			else
396 				len = 0;
397 		} else
398 			len = -1;
399 
400 		if (len == 0) {
401 			/* child exited OK, don't print a warning message */
402 		} else if (len != -1) {
403 			log_warnx("lost child: pid %u %s", pid, cause);
404 			free(cause);
405 		} else
406 			log_warnx("lost child: pid %u", pid);
407 	} while (pid != -1 || (pid == -1 && errno == EINTR));
408 }
409 
410 void
411 proc_open(struct privsep *ps, int src, int dst)
412 {
413 	struct privsep_pipes *pa, *pb;
414 	struct privsep_fd pf;
415 	int fds[2];
416 	unsigned int i, j;
417 
418 	/* Exchange pipes between process. */
419 	for (i = 0; i < ps->ps_instances[src]; i++) {
420 		for (j = 0; j < ps->ps_instances[dst]; j++) {
421 			/* Don't create sockets for ourself. */
422 			if (src == dst && i == j)
423 				continue;
424 
425 			pa = &ps->ps_pipes[src][i];
426 			pb = &ps->ps_pipes[dst][j];
427 			int sock_flags = SOCK_STREAM | SOCK_NONBLOCK;
428 #ifdef SOCK_CLOEXEC
429 			sock_flags |= SOCK_CLOEXEC;
430 #endif
431 			if (socketpair(AF_UNIX, sock_flags,
432 			    PF_UNSPEC, fds) == -1)
433 				fatal("%s: socketpair", __func__);
434 
435 			pa->pp_pipes[dst][j] = fds[0];
436 			pb->pp_pipes[src][i] = fds[1];
437 
438 			pf.pf_procid = src;
439 			pf.pf_instance = i;
440 			if (proc_compose_imsg(ps, dst, j, IMSG_CTL_PROCFD,
441 			    -1, pb->pp_pipes[src][i], &pf, sizeof(pf)) == -1)
442 				fatal("%s: proc_compose_imsg", __func__);
443 
444 			pf.pf_procid = dst;
445 			pf.pf_instance = j;
446 			if (proc_compose_imsg(ps, src, i, IMSG_CTL_PROCFD,
447 			    -1, pa->pp_pipes[dst][j], &pf, sizeof(pf)) == -1)
448 				fatal("%s: proc_compose_imsg", __func__);
449 
450 			/*
451 			 * We have to flush to send the descriptors and close
452 			 * them to avoid the fd ramp on startup.
453 			 */
454 			if (proc_flush_imsg(ps, src, i) == -1 ||
455 			    proc_flush_imsg(ps, dst, j) == -1)
456 				fatal("%s: imsg_flush", __func__);
457 		}
458 	}
459 }
460 
461 void
462 proc_close(struct privsep *ps)
463 {
464 	unsigned int dst, n;
465 	struct privsep_pipes *pp;
466 
467 	if (ps == NULL)
468 		return;
469 
470 	pp = ps->ps_pp;
471 
472 	for (dst = 0; dst < PROC_MAX; dst++) {
473 		if (ps->ps_ievs[dst] == NULL)
474 			continue;
475 
476 		for (n = 0; n < ps->ps_instances[dst]; n++) {
477 			if (pp->pp_pipes[dst][n] == -1)
478 				continue;
479 
480 			/* Cancel the fd, close and invalidate the fd */
481 			event_del(&(ps->ps_ievs[dst][n].ev));
482 			imsg_clear(&(ps->ps_ievs[dst][n].ibuf));
483 			close(pp->pp_pipes[dst][n]);
484 			pp->pp_pipes[dst][n] = -1;
485 		}
486 		free(ps->ps_ievs[dst]);
487 	}
488 }
489 
490 void
491 proc_shutdown(struct privsep_proc *p)
492 {
493 	struct privsep *ps = p->p_ps;
494 
495 	if (p->p_shutdown != NULL)
496 		(*p->p_shutdown)();
497 
498 	proc_close(ps);
499 
500 	log_info("%s, %s exiting, pid %d", getprogname(), p->p_title, getpid());
501 
502 	exit(0);
503 }
504 
505 void
506 proc_sig_handler(int sig, short event, void *arg)
507 {
508 	struct privsep_proc *p = arg;
509 
510 	switch (sig) {
511 	case SIGINT:
512 	case SIGTERM:
513 		proc_shutdown(p);
514 		break;
515 	case SIGCHLD:
516 	case SIGHUP:
517 	case SIGPIPE:
518 	case SIGUSR1:
519 		/* ignore */
520 		break;
521 	default:
522 		fatalx("proc_sig_handler: unexpected signal");
523 		/* NOTREACHED */
524 	}
525 }
526 
527 void
528 proc_run(struct privsep *ps, struct privsep_proc *p,
529     struct privsep_proc *procs, unsigned int nproc,
530     void (*run)(struct privsep *, struct privsep_proc *, void *), void *arg)
531 {
532 	struct passwd *pw;
533 	const char *root;
534 
535 	log_procinit(p->p_title);
536 
537 	/* Set the process group of the current process */
538 	setpgid(0, 0);
539 
540 	/* Use non-standard user */
541 	if (p->p_pw != NULL)
542 		pw = p->p_pw;
543 	else
544 		pw = ps->ps_pw;
545 
546 	/* Change root directory */
547 	if (p->p_chroot != NULL)
548 		root = p->p_chroot;
549 	else
550 		root = pw->pw_dir;
551 
552 	if (chroot(root) == -1)
553 		fatal("proc_run: chroot");
554 	if (chdir("/") == -1)
555 		fatal("proc_run: chdir(\"/\")");
556 
557 	privsep_process = p->p_id;
558 
559 	setproctitle("%s", p->p_title);
560 
561 	if (setgroups(1, &pw->pw_gid) ||
562 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
563 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
564 		fatal("proc_run: cannot drop privileges");
565 
566 	event_init();
567 
568 	signal_set(&ps->ps_evsigint, SIGINT, proc_sig_handler, p);
569 	signal_set(&ps->ps_evsigterm, SIGTERM, proc_sig_handler, p);
570 	signal_set(&ps->ps_evsigchld, SIGCHLD, proc_sig_handler, p);
571 	signal_set(&ps->ps_evsighup, SIGHUP, proc_sig_handler, p);
572 	signal_set(&ps->ps_evsigpipe, SIGPIPE, proc_sig_handler, p);
573 	signal_set(&ps->ps_evsigusr1, SIGUSR1, proc_sig_handler, p);
574 
575 	signal_add(&ps->ps_evsigint, NULL);
576 	signal_add(&ps->ps_evsigterm, NULL);
577 	signal_add(&ps->ps_evsigchld, NULL);
578 	signal_add(&ps->ps_evsighup, NULL);
579 	signal_add(&ps->ps_evsigpipe, NULL);
580 	signal_add(&ps->ps_evsigusr1, NULL);
581 
582 	proc_setup(ps, procs, nproc);
583 	proc_accept(ps, PROC_GOTWEBD_SOCK_FILENO, PROC_GOTWEBD, 0);
584 
585 	DPRINTF("%s: %s %d/%d, pid %d", __func__, p->p_title,
586 	    ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid());
587 
588 	if (run != NULL)
589 		run(ps, p, arg);
590 
591 	event_dispatch();
592 
593 	proc_shutdown(p);
594 }
595 
596 void
597 proc_dispatch(int fd, short event, void *arg)
598 {
599 	struct imsgev *iev = arg;
600 	struct privsep_proc *p = iev->proc;
601 	struct privsep *ps = p->p_ps;
602 	struct imsgbuf *ibuf;
603 	struct imsg imsg;
604 	ssize_t n;
605 	int verbose;
606 	const char *title;
607 	struct privsep_fd pf;
608 
609 	title = ps->ps_title[privsep_process];
610 	ibuf = &iev->ibuf;
611 
612 	if (event & EV_READ) {
613 		n = imsg_read(ibuf);
614 		if (n == -1 && errno != EAGAIN)
615 			fatal("%s: imsg_read", __func__);
616 		if (n == 0) {
617 			/* this pipe is dead, so remove the event handler */
618 			event_del(&iev->ev);
619 			event_loopexit(NULL);
620 			return;
621 		}
622 	}
623 
624 	if (event & EV_WRITE) {
625 		n = msgbuf_write(&ibuf->w);
626 		if (n == -1 && errno != EAGAIN)
627 			fatal("%s: msgbuf_write", __func__);
628 		if (n == 0) {
629 			/* this pipe is dead, so remove the event handler */
630 			event_del(&iev->ev);
631 			event_loopexit(NULL);
632 			return;
633 		}
634 	}
635 
636 	for (;;) {
637 		n = imsg_get(ibuf, &imsg);
638 		if (n == -1)
639 			fatal("%s: imsg_get", __func__);
640 		if (n == 0)
641 			break;
642 
643 #if DEBUG > 1
644 		log_debug("%s: %s %d got imsg %d peerid %d from %s %d",
645 		    __func__, title, ps->ps_instance + 1,
646 		    imsg.hdr.type, imsg.hdr.peerid, p->p_title, imsg.hdr.pid);
647 #endif
648 
649 		/*
650 		 * Check the message with the program callback
651 		 */
652 		if ((p->p_cb)(fd, p, &imsg) == 0) {
653 			/* Message was handled by the callback, continue */
654 			imsg_free(&imsg);
655 			continue;
656 		}
657 
658 		/*
659 		 * Generic message handling
660 		 */
661 		switch (imsg.hdr.type) {
662 		case IMSG_CTL_VERBOSE:
663 			log_info("%s", __func__);
664 			IMSG_SIZE_CHECK(&imsg, &verbose);
665 			memcpy(&verbose, imsg.data, sizeof(verbose));
666 			log_setverbose(verbose);
667 			break;
668 		case IMSG_CTL_PROCFD:
669 			IMSG_SIZE_CHECK(&imsg, &pf);
670 			memcpy(&pf, imsg.data, sizeof(pf));
671 			proc_accept(ps, imsg.fd, pf.pf_procid,
672 			    pf.pf_instance);
673 			break;
674 		default:
675 			log_warnx("%s: %s %d got invalid imsg %d peerid %d "
676 			    "from %s %d",
677 			    __func__, title, ps->ps_instance + 1,
678 			    imsg.hdr.type, imsg.hdr.peerid,
679 			    p->p_title, imsg.hdr.pid);
680 		}
681 		imsg_free(&imsg);
682 	}
683 	imsg_event_add(iev);
684 }
685 
686 int
687 proc_dispatch_null(int fd, struct privsep_proc *p, struct imsg *imsg)
688 {
689 	return (-1);
690 }
691 
692 /*
693  * imsg helper functions
694  */
695 
696 void
697 imsg_event_add(struct imsgev *iev)
698 {
699 	if (iev->handler == NULL) {
700 		imsg_flush(&iev->ibuf);
701 		return;
702 	}
703 
704 	iev->events = EV_READ;
705 	if (iev->ibuf.w.queued)
706 		iev->events |= EV_WRITE;
707 
708 	event_del(&iev->ev);
709 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
710 	event_add(&iev->ev, NULL);
711 }
712 
713 int
714 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
715     pid_t pid, int fd, void *data, uint16_t datalen)
716 {
717 	int ret;
718 
719 	ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data, datalen);
720 	if (ret == -1)
721 		return (ret);
722 	imsg_event_add(iev);
723 	return (ret);
724 }
725 
726 int
727 imsg_composev_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
728     pid_t pid, int fd, const struct iovec *iov, int iovcnt)
729 {
730 	int ret;
731 
732 	ret = imsg_composev(&iev->ibuf, type, peerid, pid, fd, iov, iovcnt);
733 	if (ret == -1)
734 		return (ret);
735 	imsg_event_add(iev);
736 	return (ret);
737 }
738 
739 void
740 proc_range(struct privsep *ps, enum privsep_procid id, int *n, int *m)
741 {
742 	if (*n == -1) {
743 		/* Use a range of all target instances */
744 		*n = 0;
745 		*m = ps->ps_instances[id];
746 	} else {
747 		/* Use only a single slot of the specified peer process */
748 		*m = *n + 1;
749 	}
750 }
751 
752 int
753 proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n,
754     uint16_t type, uint32_t peerid, int fd, void *data, uint16_t datalen)
755 {
756 	int m;
757 
758 	proc_range(ps, id, &n, &m);
759 	for (; n < m; n++) {
760 		if (imsg_compose_event(&ps->ps_ievs[id][n],
761 		    type, peerid, ps->ps_instance + 1, fd, data, datalen) == -1)
762 			return (-1);
763 	}
764 
765 	return (0);
766 }
767 
768 int
769 proc_compose(struct privsep *ps, enum privsep_procid id,
770     uint16_t type, void *data, uint16_t datalen)
771 {
772 	return (proc_compose_imsg(ps, id, -1, type, -1, -1, data, datalen));
773 }
774 
775 int
776 proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n,
777     uint16_t type, uint32_t peerid, int fd, const struct iovec *iov, int iovcnt)
778 {
779 	int m;
780 
781 	proc_range(ps, id, &n, &m);
782 	for (; n < m; n++)
783 		if (imsg_composev_event(&ps->ps_ievs[id][n],
784 		    type, peerid, ps->ps_instance + 1, fd, iov, iovcnt) == -1)
785 			return (-1);
786 
787 	return (0);
788 }
789 
790 int
791 proc_composev(struct privsep *ps, enum privsep_procid id,
792     uint16_t type, const struct iovec *iov, int iovcnt)
793 {
794 	return (proc_composev_imsg(ps, id, -1, type, -1, -1, iov, iovcnt));
795 }
796 
797 int
798 proc_forward_imsg(struct privsep *ps, struct imsg *imsg,
799     enum privsep_procid id, int n)
800 {
801 	return (proc_compose_imsg(ps, id, n, imsg->hdr.type,
802 	    imsg->hdr.peerid, imsg->fd, imsg->data, IMSG_DATA_SIZE(imsg)));
803 }
804 
805 struct imsgbuf *
806 proc_ibuf(struct privsep *ps, enum privsep_procid id, int n)
807 {
808 	int m;
809 
810 	proc_range(ps, id, &n, &m);
811 	return (&ps->ps_ievs[id][n].ibuf);
812 }
813 
814 struct imsgev *
815 proc_iev(struct privsep *ps, enum privsep_procid id, int n)
816 {
817 	int m;
818 
819 	proc_range(ps, id, &n, &m);
820 	return (&ps->ps_ievs[id][n]);
821 }
822 
823 /* This function should only be called with care as it breaks async I/O */
824 int
825 proc_flush_imsg(struct privsep *ps, enum privsep_procid id, int n)
826 {
827 	struct imsgbuf *ibuf;
828 	int m, ret = 0;
829 
830 	proc_range(ps, id, &n, &m);
831 	for (; n < m; n++) {
832 		ibuf = proc_ibuf(ps, id, n);
833 		if (ibuf == NULL)
834 			return (-1);
835 		do {
836 			ret = imsg_flush(ibuf);
837 		} while (ret == -1 && errno == EAGAIN);
838 		if (ret == -1)
839 			break;
840 		imsg_event_add(&ps->ps_ievs[id][n]);
841 	}
842 
843 	return (ret);
844 }