ypldap.c revision 290938 
1/*	$OpenBSD: ypldap.c,v 1.16 2015/11/02 10:06:06 jmatthew Exp $ */
2/*	$FreeBSD */
3
4/*
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/param.h>
22#include <sys/queue.h>
23#include <sys/socket.h>
24#include <sys/signal.h>
25#include <sys/tree.h>
26#include <sys/wait.h>
27
28#include <netinet/in.h>
29#include <arpa/inet.h>
30
31#include <err.h>
32#include <errno.h>
33#include <event.h>
34#include <unistd.h>
35#include <pwd.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <string.h>
39#include <limits.h>
40
41#include "ypldap.h"
42
43__dead2 void	 usage(void);
44int		 check_child(pid_t, const char *);
45void		 main_sig_handler(int, short, void *);
46void		 main_shutdown(void);
47void		 main_dispatch_client(int, short, void *);
48void		 main_configure_client(struct env *);
49void		 main_init_timer(int, short, void *);
50void		 main_start_update(struct env *);
51void		 main_trash_update(struct env *);
52void		 main_end_update(struct env *);
53int		 main_create_user_groups(struct env *);
54void		 purge_config(struct env *);
55void		 reconfigure(struct env *);
56
57int		 pipe_main2client[2];
58
59pid_t		 client_pid = 0;
60char		*conffile = YPLDAP_CONF_FILE;
61int		 opts = 0;
62
63void
64usage(void)
65{
66	extern const char	*__progname;
67
68	fprintf(stderr, "usage: %s [-dnv] [-D macro=value] [-f file]\n",
69	    __progname);
70	exit(1);
71}
72
73int
74check_child(pid_t pid, const char *pname)
75{
76	int	status;
77
78	if (waitpid(pid, &status, WNOHANG) > 0) {
79		if (WIFEXITED(status)) {
80			log_warnx("check_child: lost child %s exited", pname);
81			return (1);
82		}
83		if (WIFSIGNALED(status)) {
84			log_warnx("check_child: lost child %s terminated; "
85			    "signal %d", pname, WTERMSIG(status));
86			return (1);
87		}
88	}
89	return (0);
90}
91
92/* ARGUSED */
93void
94main_sig_handler(int sig, short event, void *p)
95{
96	int		 die = 0;
97
98	switch (sig) {
99	case SIGTERM:
100	case SIGINT:
101		die = 1;
102		/* FALLTHROUGH */
103	case SIGCHLD:
104		if (check_child(client_pid, "ldap client")) {
105			client_pid = 0;
106			die = 1;
107		}
108		if (die)
109			main_shutdown();
110		break;
111	case SIGHUP:
112		/* reconfigure */
113		break;
114	default:
115		fatalx("unexpected signal");
116	}
117}
118
119void
120main_shutdown(void)
121{
122	_exit(0);
123}
124
125void
126main_start_update(struct env *env)
127{
128	env->update_trashed = 0;
129
130	log_debug("starting directory update");
131	env->sc_user_line_len = 0;
132	env->sc_group_line_len = 0;
133	if ((env->sc_user_names_t = calloc(1,
134	    sizeof(*env->sc_user_names_t))) == NULL ||
135	    (env->sc_group_names_t = calloc(1,
136	    sizeof(*env->sc_group_names_t))) == NULL)
137		fatal(NULL);
138	RB_INIT(env->sc_user_names_t);
139	RB_INIT(env->sc_group_names_t);
140}
141
142/*
143 * XXX: Currently this function should only be called when updating is
144 * finished. A notification should be send to ldapclient that it should stop
145 * sending new pwd/grp entries before it can be called from different places.
146 */
147void
148main_trash_update(struct env *env)
149{
150	struct userent	*ue;
151	struct groupent	*ge;
152
153	env->update_trashed = 1;
154
155	while ((ue = RB_ROOT(env->sc_user_names_t)) != NULL) {
156		RB_REMOVE(user_name_tree,
157		    env->sc_user_names_t, ue);
158		free(ue->ue_line);
159		free(ue->ue_netid_line);
160		free(ue);
161	}
162	free(env->sc_user_names_t);
163	env->sc_user_names_t = NULL;
164	while ((ge = RB_ROOT(env->sc_group_names_t))
165	    != NULL) {
166		RB_REMOVE(group_name_tree,
167		    env->sc_group_names_t, ge);
168		free(ge->ge_line);
169		free(ge);
170	}
171	free(env->sc_group_names_t);
172	env->sc_group_names_t = NULL;
173}
174
175int
176main_create_user_groups(struct env *env)
177{
178	struct userent		*ue;
179	struct userent		 ukey;
180	struct groupent		*ge;
181	gid_t			 pw_gid;
182	char			*bp, *cp;
183	char			*p;
184	const char		*errstr = NULL;
185	size_t			 len;
186
187	RB_FOREACH(ue, user_name_tree, env->sc_user_names_t) {
188		bp = cp = ue->ue_line;
189
190		/* name */
191		bp += strlen(bp) + 1;
192
193		/* password */
194		bp += strcspn(bp, ":") + 1;
195
196		/* uid */
197		bp += strcspn(bp, ":") + 1;
198
199		/* gid */
200		bp[strcspn(bp, ":")] = '\0';
201
202		pw_gid = (gid_t)strtonum(bp, 0, GID_MAX, &errstr);
203		if (errstr) {
204			log_warnx("main: failed to parse gid for uid: %d\n", ue->ue_uid);
205			return (-1);
206		}
207
208		/* bring gid column back to its proper state */
209		bp[strlen(bp)] = ':';
210
211		if ((ue->ue_netid_line = calloc(1, LINE_WIDTH)) == NULL) {
212			return (-1);
213		}
214
215		if (snprintf(ue->ue_netid_line, LINE_WIDTH-1, "%d:%d", ue->ue_uid, pw_gid) >= LINE_WIDTH) {
216
217			return (-1);
218		}
219
220		ue->ue_gid = pw_gid;
221	}
222
223	RB_FOREACH(ge, group_name_tree, env->sc_group_names_t) {
224		bp = cp = ge->ge_line;
225
226		/* name */
227		bp += strlen(bp) + 1;
228
229		/* password */
230		bp += strcspn(bp, ":") + 1;
231
232		/* gid */
233		bp += strcspn(bp, ":") + 1;
234
235		cp = bp;
236		if (*bp == '\0')
237			continue;
238		bp = cp;
239		for (;;) {
240			if (!(cp = strsep(&bp, ",")))
241				break;
242			ukey.ue_line = cp;
243			if ((ue = RB_FIND(user_name_tree, env->sc_user_names_t,
244			    &ukey)) == NULL) {
245				/* User not found */
246				log_warnx("main: user: %s is referenced as a "
247					"group member, but can't be found in the "
248					"users map.\n", ukey.ue_line);
249				if (bp != NULL)
250					*(bp-1) = ',';
251				continue;
252			}
253			if (bp != NULL)
254				*(bp-1) = ',';
255
256			/* Make sure the new group doesn't equal to the main gid */
257			if (ge->ge_gid == ue->ue_gid)
258				continue;
259
260			len = strlen(ue->ue_netid_line);
261			p = ue->ue_netid_line + len;
262
263			if ((snprintf(p, LINE_WIDTH-len-1, ",%d",
264				ge->ge_gid)) >= (int)(LINE_WIDTH-len)) {
265				return (-1);
266			}
267		}
268	}
269
270	return (0);
271}
272
273void
274main_end_update(struct env *env)
275{
276	struct userent		*ue;
277	struct groupent		*ge;
278
279	if (env->update_trashed)
280		return;
281
282	log_debug("updates are over, cleaning up trees now");
283
284	if (main_create_user_groups(env) == -1) {
285		main_trash_update(env);
286		return;
287	}
288
289	if (env->sc_user_names == NULL) {
290		env->sc_user_names = env->sc_user_names_t;
291		env->sc_user_lines = NULL;
292		env->sc_user_names_t = NULL;
293
294		env->sc_group_names = env->sc_group_names_t;
295		env->sc_group_lines = NULL;
296		env->sc_group_names_t = NULL;
297
298		flatten_entries(env);
299		goto make_uids;
300	}
301
302	/*
303	 * clean previous tree.
304	 */
305	while ((ue = RB_ROOT(env->sc_user_names)) != NULL) {
306		RB_REMOVE(user_name_tree, env->sc_user_names,
307		    ue);
308		free(ue->ue_netid_line);
309		free(ue);
310	}
311	free(env->sc_user_names);
312	free(env->sc_user_lines);
313
314	env->sc_user_names = env->sc_user_names_t;
315	env->sc_user_lines = NULL;
316	env->sc_user_names_t = NULL;
317
318	while ((ge = RB_ROOT(env->sc_group_names)) != NULL) {
319		RB_REMOVE(group_name_tree,
320		    env->sc_group_names, ge);
321		free(ge);
322	}
323	free(env->sc_group_names);
324	free(env->sc_group_lines);
325
326	env->sc_group_names = env->sc_group_names_t;
327	env->sc_group_lines = NULL;
328	env->sc_group_names_t = NULL;
329
330
331	flatten_entries(env);
332
333	/*
334	 * trees are flat now. build up uid, gid and netid trees.
335	 */
336
337make_uids:
338	RB_INIT(&env->sc_user_uids);
339	RB_INIT(&env->sc_group_gids);
340	RB_FOREACH(ue, user_name_tree, env->sc_user_names)
341		RB_INSERT(user_uid_tree,
342		    &env->sc_user_uids, ue);
343	RB_FOREACH(ge, group_name_tree, env->sc_group_names)
344		RB_INSERT(group_gid_tree,
345		    &env->sc_group_gids, ge);
346
347}
348
349void
350main_dispatch_client(int fd, short events, void *p)
351{
352	int		 n;
353	int		 shut = 0;
354	struct env	*env = p;
355	struct imsgev	*iev = env->sc_iev;
356	struct imsgbuf	*ibuf = &iev->ibuf;
357	struct idm_req	 ir;
358	struct imsg	 imsg;
359
360	if ((events & (EV_READ | EV_WRITE)) == 0)
361		fatalx("unknown event");
362
363	if (events & EV_READ) {
364		if ((n = imsg_read(ibuf)) == -1)
365			fatal("imsg_read error");
366		if (n == 0)
367			shut = 1;
368	}
369	if (events & EV_WRITE) {
370		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
371			fatal("msgbuf_write");
372		if (n == 0)
373			shut = 1;
374		goto done;
375	}
376
377	for (;;) {
378		if ((n = imsg_get(ibuf, &imsg)) == -1)
379			fatal("main_dispatch_client: imsg_get error");
380		if (n == 0)
381			break;
382
383		switch (imsg.hdr.type) {
384		case IMSG_START_UPDATE:
385			main_start_update(env);
386			break;
387		case IMSG_PW_ENTRY: {
388			struct userent	*ue;
389			size_t		 len;
390
391			if (env->update_trashed)
392				break;
393
394			(void)memcpy(&ir, imsg.data, sizeof(ir));
395			if ((ue = calloc(1, sizeof(*ue))) == NULL ||
396			    (ue->ue_line = strdup(ir.ir_line)) == NULL) {
397				/*
398				 * should cancel tree update instead.
399				 */
400				fatal("out of memory");
401			}
402			ue->ue_uid = ir.ir_key.ik_uid;
403			len = strlen(ue->ue_line) + 1;
404			ue->ue_line[strcspn(ue->ue_line, ":")] = '\0';
405			if (RB_INSERT(user_name_tree, env->sc_user_names_t,
406			    ue) != NULL) { /* dup */
407				free(ue->ue_line);
408				free(ue);
409			} else
410				env->sc_user_line_len += len;
411			break;
412		}
413		case IMSG_GRP_ENTRY: {
414			struct groupent	*ge;
415			size_t		 len;
416
417			if (env->update_trashed)
418				break;
419
420			(void)memcpy(&ir, imsg.data, sizeof(ir));
421			if ((ge = calloc(1, sizeof(*ge))) == NULL ||
422			    (ge->ge_line = strdup(ir.ir_line)) == NULL) {
423				/*
424				 * should cancel tree update instead.
425				 */
426				fatal("out of memory");
427			}
428			ge->ge_gid = ir.ir_key.ik_gid;
429			len = strlen(ge->ge_line) + 1;
430			ge->ge_line[strcspn(ge->ge_line, ":")] = '\0';
431			if (RB_INSERT(group_name_tree, env->sc_group_names_t,
432			    ge) != NULL) { /* dup */
433				free(ge->ge_line);
434				free(ge);
435			} else
436				env->sc_group_line_len += len;
437			break;
438		}
439		case IMSG_TRASH_UPDATE:
440			main_trash_update(env);
441			break;
442		case IMSG_END_UPDATE: {
443			main_end_update(env);
444			break;
445		}
446		default:
447			log_debug("main_dispatch_client: unexpected imsg %d",
448			   imsg.hdr.type);
449			break;
450		}
451		imsg_free(&imsg);
452	}
453
454done:
455	if (!shut)
456		imsg_event_add(iev);
457	else {
458		log_debug("king bula sez: ran into dead pipe");
459		event_del(&iev->ev);
460		event_loopexit(NULL);
461	}
462}
463
464void
465main_configure_client(struct env *env)
466{
467	struct idm	*idm;
468	struct imsgev	*iev = env->sc_iev;
469
470	imsg_compose_event(iev, IMSG_CONF_START, 0, 0, -1, env, sizeof(*env));
471	TAILQ_FOREACH(idm, &env->sc_idms, idm_entry) {
472		imsg_compose_event(iev, IMSG_CONF_IDM, 0, 0, -1,
473		    idm, sizeof(*idm));
474	}
475	imsg_compose_event(iev, IMSG_CONF_END, 0, 0, -1, NULL, 0);
476}
477
478void
479main_init_timer(int fd, short event, void *p)
480{
481	struct env	*env = p;
482
483	main_configure_client(env);
484}
485
486void
487purge_config(struct env *env)
488{
489	struct idm	*idm;
490
491	while ((idm = TAILQ_FIRST(&env->sc_idms)) != NULL) {
492		TAILQ_REMOVE(&env->sc_idms, idm, idm_entry);
493		free(idm);
494	}
495}
496
497int
498main(int argc, char *argv[])
499{
500	int		 c;
501	int		 debug;
502	struct passwd	*pw;
503	struct env	 env;
504	struct event	 ev_sigint;
505	struct event	 ev_sigterm;
506	struct event	 ev_sigchld;
507	struct event	 ev_sighup;
508	struct event	 ev_timer;
509	struct timeval	 tv;
510
511	debug = 0;
512	ypldap_process = PROC_MAIN;
513
514	log_init(1);
515
516	while ((c = getopt(argc, argv, "dD:nf:v")) != -1) {
517		switch (c) {
518		case 'd':
519			debug = 2;
520			break;
521		case 'D':
522			if (cmdline_symset(optarg) < 0)
523				log_warnx("could not parse macro definition %s",
524				    optarg);
525			break;
526		case 'n':
527			debug = 2;
528			opts |= YPLDAP_OPT_NOACTION;
529			break;
530		case 'f':
531			conffile = optarg;
532			break;
533		case 'v':
534			opts |= YPLDAP_OPT_VERBOSE;
535			break;
536		default:
537			usage();
538		}
539	}
540
541	argc -= optind;
542	argv += optind;
543
544	if (argc)
545		usage();
546
547	RB_INIT(&env.sc_user_uids);
548	RB_INIT(&env.sc_group_gids);
549
550	if (parse_config(&env, conffile, opts))
551		exit(1);
552	if (opts & YPLDAP_OPT_NOACTION) {
553		fprintf(stderr, "configuration OK\n");
554		exit(0);
555	}
556
557	if (geteuid())
558		errx(1, "need root privileges");
559
560	log_init(debug);
561
562	if (!debug) {
563		if (daemon(1, 0) == -1)
564			err(1, "failed to daemonize");
565	}
566
567	log_info("startup%s", (debug > 1)?" [debug mode]":"");
568
569	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, PF_UNSPEC,
570	    pipe_main2client) == -1)
571		fatal("socketpair");
572
573	client_pid = ldapclient(pipe_main2client);
574
575	setproctitle("parent");
576	event_init();
577
578	signal_set(&ev_sigint, SIGINT, main_sig_handler, &env);
579	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, &env);
580	signal_set(&ev_sighup, SIGHUP, main_sig_handler, &env);
581	signal_set(&ev_sigchld, SIGCHLD, main_sig_handler, &env);
582	signal_add(&ev_sigint, NULL);
583	signal_add(&ev_sigterm, NULL);
584	signal_add(&ev_sighup, NULL);
585	signal_add(&ev_sigchld, NULL);
586
587	close(pipe_main2client[1]);
588	if ((env.sc_iev = calloc(1, sizeof(*env.sc_iev))) == NULL)
589		fatal(NULL);
590	imsg_init(&env.sc_iev->ibuf, pipe_main2client[0]);
591	env.sc_iev->handler = main_dispatch_client;
592
593	env.sc_iev->events = EV_READ;
594	env.sc_iev->data = &env;
595	event_set(&env.sc_iev->ev, env.sc_iev->ibuf.fd, env.sc_iev->events,
596	     env.sc_iev->handler, &env);
597	event_add(&env.sc_iev->ev, NULL);
598
599	yp_init(&env);
600
601	if ((pw = getpwnam(YPLDAP_USER)) == NULL)
602		fatal("getpwnam");
603
604#ifndef DEBUG
605	if (setgroups(1, &pw->pw_gid) ||
606	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
607	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
608		fatal("cannot drop privileges");
609#else
610#warning disabling privilege revocation in debug mode
611#endif
612
613	bzero(&tv, sizeof(tv));
614	evtimer_set(&ev_timer, main_init_timer, &env);
615	evtimer_add(&ev_timer, &tv);
616
617	yp_enable_events();
618	event_dispatch();
619	main_shutdown();
620
621	return (0);
622}
623
624void
625imsg_event_add(struct imsgev *iev)
626{
627	if (iev->handler == NULL) {
628		imsg_flush(&iev->ibuf);
629		return;
630	}
631
632	iev->events = EV_READ;
633	if (iev->ibuf.w.queued)
634		iev->events |= EV_WRITE;
635
636	event_del(&iev->ev);
637	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
638	event_add(&iev->ev, NULL);
639}
640
641int
642imsg_compose_event(struct imsgev *iev, u_int16_t type, u_int32_t peerid,
643    pid_t pid, int fd, void *data, u_int16_t datalen)
644{
645	int	ret;
646
647	if ((ret = imsg_compose(&iev->ibuf, type, peerid,
648	    pid, fd, data, datalen)) != -1)
649		imsg_event_add(iev);
650	return (ret);
651}
652