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