xref: /openbsd-src/sbin/iked/proc.c (revision 0e59d0d19ca6a10a17663d531bcea1b99c1bfe09)
1 /*	$OpenBSD: proc.c,v 1.51 2024/11/21 13:35:20 claudio Exp $	*/
2 
3 /*
4  * Copyright (c) 2010 - 2016 Reyk Floeter <reyk@openbsd.org>
5  * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <sys/queue.h>
22 #include <sys/socket.h>
23 #include <sys/wait.h>
24 
25 #include <fcntl.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <unistd.h>
29 #include <string.h>
30 #include <errno.h>
31 #include <signal.h>
32 #include <paths.h>
33 #include <pwd.h>
34 #include <event.h>
35 #include <imsg.h>
36 
37 #include "iked.h"
38 
39 enum privsep_procid privsep_process;
40 
41 void	 proc_exec(struct privsep *, struct privsep_proc *, unsigned int, int,
42 	    char **);
43 void	 proc_setup(struct privsep *, struct privsep_proc *, unsigned int);
44 void	 proc_open(struct privsep *, int, int);
45 void	 proc_accept(struct privsep *, int, enum privsep_procid,
46 	    unsigned int);
47 void	 proc_close(struct privsep *);
48 void	 proc_shutdown(struct privsep_proc *);
49 void	 proc_sig_handler(int, short, void *);
50 void	 proc_range(struct privsep *, enum privsep_procid, int *, int *);
51 int	 proc_dispatch_null(int, struct privsep_proc *, struct imsg *);
52 
53 enum privsep_procid
54 proc_getid(struct privsep_proc *procs, unsigned int nproc,
55     const char *proc_name)
56 {
57 	struct privsep_proc	*p;
58 	unsigned int		 proc;
59 
60 	for (proc = 0; proc < nproc; proc++) {
61 		p = &procs[proc];
62 		if (strcmp(p->p_title, proc_name))
63 			continue;
64 
65 		return (p->p_id);
66 	}
67 
68 	return (PROC_MAX);
69 }
70 
71 void
72 proc_exec(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
73     int argc, char **argv)
74 {
75 	unsigned int		 proc, nargc, i, proc_i;
76 	char			**nargv;
77 	struct privsep_proc	*p;
78 	char			 num[32];
79 	int			 fd;
80 
81 	/* Prepare the new process argv. */
82 	nargv = calloc(argc + 5, sizeof(char *));
83 	if (nargv == NULL)
84 		fatal("%s: calloc", __func__);
85 
86 	/* Copy call argument first. */
87 	nargc = 0;
88 	nargv[nargc++] = argv[0];
89 
90 	/* Set process name argument and save the position. */
91 	nargv[nargc++] = "-P";
92 	proc_i = nargc;
93 	nargc++;
94 
95 	/* Point process instance arg to stack and copy the original args. */
96 	nargv[nargc++] = "-I";
97 	nargv[nargc++] = num;
98 	for (i = 1; i < (unsigned int) argc; i++)
99 		nargv[nargc++] = argv[i];
100 
101 	nargv[nargc] = NULL;
102 
103 	for (proc = 0; proc < nproc; proc++) {
104 		p = &procs[proc];
105 
106 		/* Update args with process title. */
107 		nargv[proc_i] = (char *)(uintptr_t)p->p_title;
108 
109 		/* Fire children processes. */
110 		for (i = 0; i < ps->ps_instances[p->p_id]; i++) {
111 			/* Update the process instance number. */
112 			snprintf(num, sizeof(num), "%u", i);
113 
114 			fd = ps->ps_pipes[p->p_id][i].pp_pipes[PROC_PARENT][0];
115 			ps->ps_pipes[p->p_id][i].pp_pipes[PROC_PARENT][0] = -1;
116 
117 			switch (fork()) {
118 			case -1:
119 				fatal("%s: fork", __func__);
120 				break;
121 			case 0:
122 				/* Prepare parent socket. */
123 				if (fd != PROC_PARENT_SOCK_FILENO) {
124 					if (dup2(fd, PROC_PARENT_SOCK_FILENO)
125 					    == -1)
126 						fatal("dup2");
127 				} else if (fcntl(fd, F_SETFD, 0) == -1)
128 					fatal("fcntl");
129 
130 				execvp(argv[0], nargv);
131 				fatal("%s: execvp", __func__);
132 				break;
133 			default:
134 				/* Close child end. */
135 				close(fd);
136 				break;
137 			}
138 		}
139 	}
140 	free(nargv);
141 }
142 
143 void
144 proc_connect(struct privsep *ps, void (*connected)(struct privsep *))
145 {
146 	struct imsgev		*iev;
147 	unsigned int		 src, dst, inst;
148 
149 	/* Don't distribute any sockets if we are not really going to run. */
150 	if (ps->ps_noaction) {
151 		if (connected == NULL)
152 			fatalx("%s: missing callback", __func__);
153 		connected(ps);
154 		return;
155 	}
156 	ps->ps_connected = connected;
157 
158 	for (dst = 0; dst < PROC_MAX; dst++) {
159 		/* We don't communicate with ourselves. */
160 		if (dst == PROC_PARENT)
161 			continue;
162 
163 		for (inst = 0; inst < ps->ps_instances[dst]; inst++) {
164 			iev = &ps->ps_ievs[dst][inst];
165 			if (imsgbuf_init(&iev->ibuf,
166 			    ps->ps_pp->pp_pipes[dst][inst]) == -1)
167 				fatal("%s: imsgbuf_init", __func__);
168 			imsgbuf_allow_fdpass(&iev->ibuf);
169 			event_set(&iev->ev, iev->ibuf.fd, iev->events,
170 			    iev->handler, iev->data);
171 			event_add(&iev->ev, NULL);
172 		}
173 	}
174 
175 	/* Distribute the socketpair()s for everyone. */
176 	for (src = 0; src < PROC_MAX; src++)
177 		for (dst = src; dst < PROC_MAX; dst++) {
178 			/* Parent already distributed its fds. */
179 			if (src == PROC_PARENT || dst == PROC_PARENT)
180 				continue;
181 
182 			proc_open(ps, src, dst);
183 		}
184 
185 	/*
186 	 * Finally, send a ready message to everyone:
187 	 * When this message is processed by the receiver, it has
188 	 * already processed all IMSG_CTL_PROCFD messages and all
189 	 * pipes are ready.
190 	 */
191 	for (dst = 0; dst < PROC_MAX; dst++) {
192 		if (dst == PROC_PARENT)
193 			continue;
194 		for (inst = 0; inst < ps->ps_instances[dst]; inst++) {
195 			if (proc_compose_imsg(ps, dst, inst, IMSG_CTL_PROCREADY,
196 			    -1, -1, NULL, 0) == -1)
197 				fatal("%s: proc_compose_imsg", __func__);
198 			ps->ps_connecting++;
199 #if DEBUG
200 			log_debug("%s: #%d %s %d", __func__,
201 			    ps->ps_connecting, ps->ps_title[dst], inst + 1);
202 #endif
203 		}
204 	}
205 }
206 
207 void
208 proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
209     int debug, int argc, char **argv, enum privsep_procid proc_id)
210 {
211 	struct privsep_proc	*p = NULL;
212 	struct privsep_pipes	*pa, *pb;
213 	unsigned int		 proc;
214 	unsigned int		 dst;
215 	int			 fds[2];
216 
217 	/* Don't initiate anything if we are not really going to run. */
218 	if (ps->ps_noaction)
219 		return;
220 
221 	if (proc_id == PROC_PARENT) {
222 		privsep_process = PROC_PARENT;
223 		proc_setup(ps, procs, nproc);
224 
225 		if (!debug && daemon(0, 0) == -1)
226 			fatal("failed to daemonize");
227 
228 		/*
229 		 * Create the children sockets so we can use them
230 		 * to distribute the rest of the socketpair()s using
231 		 * proc_connect() later.
232 		 */
233 		for (dst = 0; dst < PROC_MAX; dst++) {
234 			/* Don't create socket for ourselves. */
235 			if (dst == PROC_PARENT)
236 				continue;
237 
238 			for (proc = 0; proc < ps->ps_instances[dst]; proc++) {
239 				pa = &ps->ps_pipes[PROC_PARENT][0];
240 				pb = &ps->ps_pipes[dst][proc];
241 				if (socketpair(AF_UNIX,
242 				    SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
243 				    PF_UNSPEC, fds) == -1)
244 					fatal("%s: socketpair", __func__);
245 
246 				pa->pp_pipes[dst][proc] = fds[0];
247 				pb->pp_pipes[PROC_PARENT][0] = fds[1];
248 			}
249 		}
250 
251 		/* Engage! */
252 		proc_exec(ps, procs, nproc, argc, argv);
253 		return;
254 	}
255 
256 	/* Initialize a child */
257 	for (proc = 0; proc < nproc; proc++) {
258 		if (procs[proc].p_id != proc_id)
259 			continue;
260 		p = &procs[proc];
261 		break;
262 	}
263 	if (p == NULL || p->p_init == NULL)
264 		fatalx("%s: process %d missing process initialization",
265 		    __func__, proc_id);
266 
267 	p->p_init(ps, p);
268 
269 	fatalx("failed to initiate child process");
270 }
271 
272 void
273 proc_accept(struct privsep *ps, int fd, enum privsep_procid dst,
274     unsigned int n)
275 {
276 	struct privsep_pipes	*pp = ps->ps_pp;
277 	struct imsgev		*iev;
278 
279 	if (ps->ps_ievs[dst] == NULL) {
280 #if DEBUG > 1
281 		log_debug("%s: %s src %d %d to dst %d %d not connected",
282 		    __func__, ps->ps_title[privsep_process],
283 		    privsep_process, ps->ps_instance + 1,
284 		    dst, n + 1);
285 #endif
286 		close(fd);
287 		return;
288 	}
289 
290 	if (pp->pp_pipes[dst][n] != -1) {
291 		log_warnx("%s: duplicated descriptor", __func__);
292 		close(fd);
293 		return;
294 	} else
295 		pp->pp_pipes[dst][n] = fd;
296 
297 	iev = &ps->ps_ievs[dst][n];
298 	if (imsgbuf_init(&iev->ibuf, fd) == -1)
299 		fatal("%s: imsgbuf_init", __func__);
300 	imsgbuf_allow_fdpass(&iev->ibuf);
301 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
302 	event_add(&iev->ev, NULL);
303 }
304 
305 void
306 proc_setup(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc)
307 {
308 	unsigned int		 i, j, src, dst, id;
309 	struct privsep_pipes	*pp;
310 
311 	/* Initialize parent title, ps_instances and procs. */
312 	ps->ps_title[PROC_PARENT] = "parent";
313 
314 	for (src = 0; src < PROC_MAX; src++)
315 		/* Default to 1 process instance */
316 		if (ps->ps_instances[src] < 1)
317 			ps->ps_instances[src] = 1;
318 
319 	for (src = 0; src < nproc; src++) {
320 		procs[src].p_ps = ps;
321 		if (procs[src].p_cb == NULL)
322 			procs[src].p_cb = proc_dispatch_null;
323 
324 		id = procs[src].p_id;
325 		ps->ps_title[id] = procs[src].p_title;
326 		if ((ps->ps_ievs[id] = calloc(ps->ps_instances[id],
327 		    sizeof(struct imsgev))) == NULL)
328 			fatal("%s: calloc", __func__);
329 
330 		/* With this set up, we are ready to call imsgbuf_init(). */
331 		for (i = 0; i < ps->ps_instances[id]; i++) {
332 			ps->ps_ievs[id][i].handler = proc_dispatch;
333 			ps->ps_ievs[id][i].events = EV_READ;
334 			ps->ps_ievs[id][i].proc = &procs[src];
335 			ps->ps_ievs[id][i].data = &ps->ps_ievs[id][i];
336 		}
337 	}
338 
339 	/*
340 	 * Allocate pipes for all process instances (incl. parent)
341 	 *
342 	 * - ps->ps_pipes: N:M mapping
343 	 * N source processes connected to M destination processes:
344 	 * [src][instances][dst][instances], for example
345 	 * [PROC_RELAY][3][PROC_CA][3]
346 	 *
347 	 * - ps->ps_pp: per-process 1:M part of ps->ps_pipes
348 	 * Each process instance has a destination array of socketpair fds:
349 	 * [dst][instances], for example
350 	 * [PROC_PARENT][0]
351 	 */
352 	for (src = 0; src < PROC_MAX; src++) {
353 		/* Allocate destination array for each process */
354 		if ((ps->ps_pipes[src] = calloc(ps->ps_instances[src],
355 		    sizeof(struct privsep_pipes))) == NULL)
356 			fatal("%s: calloc", __func__);
357 
358 		for (i = 0; i < ps->ps_instances[src]; i++) {
359 			pp = &ps->ps_pipes[src][i];
360 
361 			for (dst = 0; dst < PROC_MAX; dst++) {
362 				/* Allocate maximum fd integers */
363 				if ((pp->pp_pipes[dst] =
364 				    calloc(ps->ps_instances[dst],
365 				    sizeof(int))) == NULL)
366 					fatal("%s: calloc", __func__);
367 
368 				/* Mark fd as unused */
369 				for (j = 0; j < ps->ps_instances[dst]; j++)
370 					pp->pp_pipes[dst][j] = -1;
371 			}
372 		}
373 	}
374 
375 	ps->ps_pp = &ps->ps_pipes[privsep_process][ps->ps_instance];
376 }
377 
378 void
379 proc_kill(struct privsep *ps)
380 {
381 	char		*cause;
382 	pid_t		 pid;
383 	int		 len, status;
384 
385 	if (privsep_process != PROC_PARENT)
386 		return;
387 
388 	proc_close(ps);
389 
390 	do {
391 		pid = waitpid(WAIT_ANY, &status, 0);
392 		if (pid <= 0)
393 			continue;
394 
395 		if (WIFSIGNALED(status)) {
396 			len = asprintf(&cause, "terminated; signal %d",
397 			    WTERMSIG(status));
398 		} else if (WIFEXITED(status)) {
399 			if (WEXITSTATUS(status) != 0)
400 				len = asprintf(&cause, "exited abnormally");
401 			else
402 				len = 0;
403 		} else
404 			len = -1;
405 
406 		if (len == 0) {
407 			/* child exited OK, don't print a warning message */
408 		} else if (len != -1) {
409 			log_warnx("lost child: pid %u %s", pid, cause);
410 			free(cause);
411 		} else
412 			log_warnx("lost child: pid %u", pid);
413 	} while (pid != -1 || (pid == -1 && errno == EINTR));
414 }
415 
416 void
417 proc_open(struct privsep *ps, int src, int dst)
418 {
419 	struct privsep_pipes	*pa, *pb;
420 	struct privsep_fd	 pf;
421 	int			 fds[2];
422 	unsigned int		 i, j;
423 
424 	/* Exchange pipes between process. */
425 	for (i = 0; i < ps->ps_instances[src]; i++) {
426 		for (j = 0; j < ps->ps_instances[dst]; j++) {
427 			/* Don't create sockets for ourself. */
428 			if (src == dst && i == j)
429 				continue;
430 
431 			pa = &ps->ps_pipes[src][i];
432 			pb = &ps->ps_pipes[dst][j];
433 			if (socketpair(AF_UNIX,
434 			    SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
435 			    PF_UNSPEC, fds) == -1)
436 				fatal("%s: socketpair", __func__);
437 
438 			pa->pp_pipes[dst][j] = fds[0];
439 			pb->pp_pipes[src][i] = fds[1];
440 
441 			pf.pf_procid = src;
442 			pf.pf_instance = i;
443 			if (proc_compose_imsg(ps, dst, j, IMSG_CTL_PROCFD,
444 			    -1, pb->pp_pipes[src][i], &pf, sizeof(pf)) == -1)
445 				fatal("%s: proc_compose_imsg", __func__);
446 
447 			pf.pf_procid = dst;
448 			pf.pf_instance = j;
449 			if (proc_compose_imsg(ps, src, i, IMSG_CTL_PROCFD,
450 			    -1, pa->pp_pipes[dst][j], &pf, sizeof(pf)) == -1)
451 				fatal("%s: proc_compose_imsg", __func__);
452 
453 			/*
454 			 * We have to flush to send the descriptors and close
455 			 * them to avoid the fd ramp on startup.
456 			 */
457 			if (proc_flush_imsg(ps, src, i) == -1 ||
458 			    proc_flush_imsg(ps, dst, j) == -1)
459 				fatal("%s: proc_flush_imsg", __func__);
460 		}
461 	}
462 }
463 
464 void
465 proc_close(struct privsep *ps)
466 {
467 	unsigned int		 dst, n;
468 	struct privsep_pipes	*pp;
469 
470 	if (ps == NULL)
471 		return;
472 
473 	pp = ps->ps_pp;
474 
475 	for (dst = 0; dst < PROC_MAX; dst++) {
476 		if (ps->ps_ievs[dst] == NULL)
477 			continue;
478 
479 		for (n = 0; n < ps->ps_instances[dst]; n++) {
480 			if (pp->pp_pipes[dst][n] == -1)
481 				continue;
482 
483 			/* Cancel the fd, close and invalidate the fd */
484 			event_del(&(ps->ps_ievs[dst][n].ev));
485 			imsgbuf_clear(&(ps->ps_ievs[dst][n].ibuf));
486 			close(pp->pp_pipes[dst][n]);
487 			pp->pp_pipes[dst][n] = -1;
488 		}
489 		free(ps->ps_ievs[dst]);
490 	}
491 }
492 
493 void
494 proc_shutdown(struct privsep_proc *p)
495 {
496 	struct privsep	*ps = p->p_ps;
497 
498 	if (p->p_shutdown != NULL)
499 		(*p->p_shutdown)();
500 
501 	proc_close(ps);
502 
503 	log_info("%s exiting, pid %d", p->p_title, getpid());
504 
505 	exit(0);
506 }
507 
508 void
509 proc_sig_handler(int sig, short event, void *arg)
510 {
511 	struct privsep_proc	*p = arg;
512 
513 	switch (sig) {
514 	case SIGINT:
515 	case SIGTERM:
516 		proc_shutdown(p);
517 		break;
518 	case SIGCHLD:
519 	case SIGHUP:
520 	case SIGPIPE:
521 	case SIGUSR1:
522 		/* ignore */
523 		break;
524 	default:
525 		fatalx("%s: unexpected signal", __func__);
526 		/* NOTREACHED */
527 	}
528 }
529 
530 void
531 proc_run(struct privsep *ps, struct privsep_proc *p,
532     struct privsep_proc *procs, unsigned int nproc,
533     void (*run)(struct privsep *, struct privsep_proc *, void *), void *arg)
534 {
535 	struct passwd		*pw;
536 	const char		*root;
537 
538 	log_procinit(p->p_title);
539 
540 	if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) {
541 		if (control_init(ps, &ps->ps_csock) == -1)
542 			fatalx("%s: control_init", __func__);
543 	}
544 
545 	/* Use non-standard user */
546 	if (p->p_pw != NULL)
547 		pw = p->p_pw;
548 	else
549 		pw = ps->ps_pw;
550 
551 	/* Change root directory */
552 	if (p->p_chroot != NULL)
553 		root = p->p_chroot;
554 	else
555 		root = pw->pw_dir;
556 
557 	if (chroot(root) == -1)
558 		fatal("%s: chroot", __func__);
559 	if (chdir("/") == -1)
560 		fatal("%s: chdir(\"/\")", __func__);
561 
562 	privsep_process = p->p_id;
563 
564 	setproctitle("%s", p->p_title);
565 
566 	if (setgroups(1, &pw->pw_gid) ||
567 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
568 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
569 		fatal("%s: cannot drop privileges", __func__);
570 
571 	event_init();
572 
573 	signal_set(&ps->ps_evsigint, SIGINT, proc_sig_handler, p);
574 	signal_set(&ps->ps_evsigterm, SIGTERM, proc_sig_handler, p);
575 	signal_set(&ps->ps_evsigchld, SIGCHLD, proc_sig_handler, p);
576 	signal_set(&ps->ps_evsighup, SIGHUP, proc_sig_handler, p);
577 	signal_set(&ps->ps_evsigpipe, SIGPIPE, proc_sig_handler, p);
578 	signal_set(&ps->ps_evsigusr1, SIGUSR1, proc_sig_handler, p);
579 
580 	signal_add(&ps->ps_evsigint, NULL);
581 	signal_add(&ps->ps_evsigterm, NULL);
582 	signal_add(&ps->ps_evsigchld, NULL);
583 	signal_add(&ps->ps_evsighup, NULL);
584 	signal_add(&ps->ps_evsigpipe, NULL);
585 	signal_add(&ps->ps_evsigusr1, NULL);
586 
587 	proc_setup(ps, procs, nproc);
588 	proc_accept(ps, PROC_PARENT_SOCK_FILENO, PROC_PARENT, 0);
589 	if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) {
590 		if (control_listen(&ps->ps_csock) == -1)
591 			fatalx("%s: control_listen", __func__);
592 	}
593 
594 #if DEBUG
595 	log_debug("%s: %s %d/%d, pid %d", __func__, p->p_title,
596 	    ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid());
597 #endif
598 
599 	if (run != NULL)
600 		run(ps, p, arg);
601 
602 	event_dispatch();
603 
604 	proc_shutdown(p);
605 }
606 
607 void
608 proc_dispatch(int fd, short event, void *arg)
609 {
610 	struct imsgev		*iev = arg;
611 	struct privsep_proc	*p = iev->proc;
612 	struct privsep		*ps = p->p_ps;
613 	struct imsgbuf		*ibuf;
614 	struct imsg		 imsg;
615 	ssize_t			 n;
616 	int			 verbose;
617 	const char		*title;
618 	struct privsep_fd	 pf;
619 
620 	title = ps->ps_title[privsep_process];
621 	ibuf = &iev->ibuf;
622 
623 	if (event & EV_READ) {
624 		if ((n = imsgbuf_read(ibuf)) == -1)
625 			fatal("%s: imsgbuf_read", __func__);
626 		if (n == 0) {
627 			/* this pipe is dead, so remove the event handler */
628 			event_del(&iev->ev);
629 			event_loopexit(NULL);
630 			return;
631 		}
632 	}
633 
634 	if (event & EV_WRITE) {
635 		if (imsgbuf_write(ibuf) == -1) {
636 			if (errno == EPIPE) {	/* Connection closed. */
637 				event_del(&iev->ev);
638 				event_loopexit(NULL);
639 				return;
640 			} else
641 				fatal("imsgbuf_write");
642 		}
643 	}
644 
645 	for (;;) {
646 		if ((n = imsg_get(ibuf, &imsg)) == -1)
647 			fatal("%s: imsg_get", __func__);
648 		if (n == 0)
649 			break;
650 
651 #if DEBUG > 1
652 		log_debug("%s: %s %d got imsg %d peerid %d from %s %d",
653 		    __func__, title, ps->ps_instance + 1,
654 		    imsg.hdr.type, imsg.hdr.peerid, p->p_title, imsg.hdr.pid);
655 #endif
656 
657 		/*
658 		 * Check the message with the program callback
659 		 */
660 		if ((p->p_cb)(fd, p, &imsg) == 0) {
661 			/* Message was handled by the callback, continue */
662 			imsg_free(&imsg);
663 			continue;
664 		}
665 
666 		/*
667 		 * Generic message handling
668 		 */
669 		switch (imsg.hdr.type) {
670 		case IMSG_CTL_VERBOSE:
671 			IMSG_SIZE_CHECK(&imsg, &verbose);
672 			memcpy(&verbose, imsg.data, sizeof(verbose));
673 			log_setverbose(verbose);
674 			break;
675 		case IMSG_CTL_PROCFD:
676 			IMSG_SIZE_CHECK(&imsg, &pf);
677 			memcpy(&pf, imsg.data, sizeof(pf));
678 			proc_accept(ps, imsg_get_fd(&imsg), pf.pf_procid,
679 			    pf.pf_instance);
680 			break;
681 		case IMSG_CTL_PROCREADY:
682 #if DEBUG
683 			log_debug("%s: ready-%s: #%d %s %d -> %s %d", __func__,
684 			    p->p_id == PROC_PARENT ? "req" : "ack",
685 			    ps->ps_connecting, p->p_title, imsg.hdr.pid,
686 			    title, ps->ps_instance + 1);
687 #endif
688 			if (p->p_id == PROC_PARENT) {
689 				/* ack that we are ready */
690 				if (proc_compose_imsg(ps, PROC_PARENT, 0,
691 				    IMSG_CTL_PROCREADY, -1, -1, NULL, 0) == -1)
692 					fatal("%s: proc_compose_imsg", __func__);
693 			} else {
694 				/* parent received ack */
695 				if (ps->ps_connecting == 0)
696 					fatalx("%s: wrong acks", __func__);
697 				if (ps->ps_instance != 0)
698 					fatalx("%s: wrong instance %d",
699 					    __func__, ps->ps_instance);
700 				if (ps->ps_connected == NULL)
701 					fatalx("%s: missing callback", __func__);
702 				if (--ps->ps_connecting == 0) {
703 					log_debug("%s: all connected", __func__);
704 					ps->ps_connected(ps);
705 				}
706 			}
707 			break;
708 		default:
709 			fatalx("%s: %s %d got invalid imsg %d peerid %d "
710 			    "from %s %d",
711 			    __func__, title, ps->ps_instance + 1,
712 			    imsg.hdr.type, imsg.hdr.peerid,
713 			    p->p_title, imsg.hdr.pid);
714 		}
715 		imsg_free(&imsg);
716 	}
717 	imsg_event_add(iev);
718 }
719 
720 int
721 proc_dispatch_null(int fd, struct privsep_proc *p, struct imsg *imsg)
722 {
723 	return (-1);
724 }
725 
726 /*
727  * imsg helper functions
728  */
729 
730 void
731 imsg_event_add(struct imsgev *iev)
732 {
733 	if (iev->handler == NULL) {
734 		imsgbuf_flush(&iev->ibuf);
735 		return;
736 	}
737 
738 	iev->events = EV_READ;
739 	if (imsgbuf_queuelen(&iev->ibuf) > 0)
740 		iev->events |= EV_WRITE;
741 
742 	event_del(&iev->ev);
743 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
744 	event_add(&iev->ev, NULL);
745 }
746 
747 int
748 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
749     pid_t pid, int fd, void *data, uint16_t datalen)
750 {
751 	int	ret;
752 
753 	if ((ret = imsg_compose(&iev->ibuf, type, peerid,
754 	    pid, fd, data, datalen)) == -1)
755 		return (ret);
756 	imsg_event_add(iev);
757 	return (ret);
758 }
759 
760 int
761 imsg_composev_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
762     pid_t pid, int fd, const struct iovec *iov, int iovcnt)
763 {
764 	int	ret;
765 
766 	if ((ret = imsg_composev(&iev->ibuf, type, peerid,
767 	    pid, fd, iov, iovcnt)) == -1)
768 		return (ret);
769 	imsg_event_add(iev);
770 	return (ret);
771 }
772 
773 void
774 proc_range(struct privsep *ps, enum privsep_procid id, int *n, int *m)
775 {
776 	if (*n == -1) {
777 		/* Use a range of all target instances */
778 		*n = 0;
779 		*m = ps->ps_instances[id];
780 	} else {
781 		/* Use only a single slot of the specified peer process */
782 		*m = *n + 1;
783 	}
784 }
785 
786 int
787 proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n,
788     uint16_t type, uint32_t peerid, int fd, void *data, uint16_t datalen)
789 {
790 	int	 m;
791 
792 	proc_range(ps, id, &n, &m);
793 	for (; n < m; n++) {
794 		if (imsg_compose_event(&ps->ps_ievs[id][n],
795 		    type, peerid, ps->ps_instance + 1, fd, data, datalen) == -1)
796 			return (-1);
797 	}
798 
799 	return (0);
800 }
801 
802 int
803 proc_compose(struct privsep *ps, enum privsep_procid id,
804     uint16_t type, void *data, uint16_t datalen)
805 {
806 	return (proc_compose_imsg(ps, id, -1, type, -1, -1, data, datalen));
807 }
808 
809 int
810 proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n,
811     uint16_t type, uint32_t peerid, int fd, const struct iovec *iov, int iovcnt)
812 {
813 	int	 m;
814 
815 	proc_range(ps, id, &n, &m);
816 	for (; n < m; n++)
817 		if (imsg_composev_event(&ps->ps_ievs[id][n],
818 		    type, peerid, ps->ps_instance + 1, fd, iov, iovcnt) == -1)
819 			return (-1);
820 
821 	return (0);
822 }
823 
824 int
825 proc_composev(struct privsep *ps, enum privsep_procid id,
826     uint16_t type, const struct iovec *iov, int iovcnt)
827 {
828 	return (proc_composev_imsg(ps, id, -1, type, -1, -1, iov, iovcnt));
829 }
830 
831 int
832 proc_forward_imsg(struct privsep *ps, struct imsg *imsg,
833     enum privsep_procid id, int n)
834 {
835 	return (proc_compose_imsg(ps, id, n, imsg->hdr.type,
836 	    imsg->hdr.peerid, -1, imsg->data, IMSG_DATA_SIZE(imsg)));
837 }
838 
839 struct imsgbuf *
840 proc_ibuf(struct privsep *ps, enum privsep_procid id, int n)
841 {
842 	int	 m;
843 
844 	proc_range(ps, id, &n, &m);
845 	return (&ps->ps_ievs[id][n].ibuf);
846 }
847 
848 struct imsgev *
849 proc_iev(struct privsep *ps, enum privsep_procid id, int n)
850 {
851 	int	 m;
852 
853 	proc_range(ps, id, &n, &m);
854 	return (&ps->ps_ievs[id][n]);
855 }
856 
857 /* This function should only be called with care as it breaks async I/O */
858 int
859 proc_flush_imsg(struct privsep *ps, enum privsep_procid id, int n)
860 {
861 	struct imsgbuf	*ibuf;
862 	int		 m, ret = 0;
863 
864 	proc_range(ps, id, &n, &m);
865 	for (; n < m; n++) {
866 		if ((ibuf = proc_ibuf(ps, id, n)) == NULL)
867 			return (-1);
868 		if ((ret = imsgbuf_flush(ibuf)) == -1)
869 			break;
870 		imsg_event_add(&ps->ps_ievs[id][n]);
871 	}
872 
873 	return (ret);
874 }
875