xref: /openbsd-src/usr.sbin/ldapd/ldapd.c (revision ae3cb403620ab940fbaabb3055fac045a63d56b7)
1 /*	$OpenBSD: ldapd.c,v 1.23 2017/03/01 00:50:12 gsoares Exp $ */
2 
3 /*
4  * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/queue.h>
20 #include <sys/stat.h>
21 #include <sys/un.h>
22 #include <sys/types.h>
23 #include <sys/wait.h>
24 
25 #include <assert.h>
26 #include <bsd_auth.h>
27 #include <ctype.h>
28 #include <err.h>
29 #include <errno.h>
30 #include <event.h>
31 #include <fcntl.h>
32 #include <login_cap.h>
33 #include <signal.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <time.h>
38 #include <unistd.h>
39 
40 #include "ldapd.h"
41 #include "log.h"
42 
43 void		 usage(void);
44 void		 ldapd_sig_handler(int fd, short why, void *data);
45 void		 ldapd_sigchld_handler(int sig, short why, void *data);
46 static void	 ldapd_imsgev(struct imsgev *iev, int code, struct imsg *imsg);
47 static void	 ldapd_needfd(struct imsgev *iev);
48 static void	 ldapd_auth_request(struct imsgev *iev, struct imsg *imsg);
49 static void	 ldapd_open_request(struct imsgev *iev, struct imsg *imsg);
50 static void	 ldapd_log_verbose(struct imsg *imsg);
51 static void	 ldapd_cleanup(char *);
52 static pid_t	 start_child(enum ldapd_process, char *, int, int, int,
53 		    char *, char *);
54 
55 struct ldapd_stats	 stats;
56 pid_t			 ldape_pid;
57 const char		*datadir = DATADIR;
58 
59 void
60 usage(void)
61 {
62 	extern char	*__progname;
63 
64 	fprintf(stderr, "usage: %s [-dnv] [-D macro=value] "
65 	    "[-f file] [-r directory] [-s file]\n", __progname);
66 	exit(1);
67 }
68 
69 void
70 ldapd_sig_handler(int sig, short why, void *data)
71 {
72 	log_info("ldapd: got signal %d", sig);
73 	if (sig == SIGINT || sig == SIGTERM)
74 		event_loopexit(NULL);
75 }
76 
77 void
78 ldapd_sigchld_handler(int sig, short why, void *data)
79 {
80 	pid_t		 pid;
81 	int		 status;
82 
83 	while ((pid = waitpid(WAIT_ANY, &status, WNOHANG)) != 0) {
84 		if (pid == -1) {
85 			if (errno == EINTR)
86 				continue;
87 			if (errno != ECHILD)
88 				log_warn("waitpid");
89 			break;
90 		}
91 
92 		if (WIFEXITED(status))
93 			log_debug("child %d exited with status %d",
94 			    pid, WEXITSTATUS(status));
95 		else if (WIFSIGNALED(status))
96 			log_debug("child %d exited due to signal %d",
97 			    pid, WTERMSIG(status));
98 		else
99 			log_debug("child %d terminated abnormally", pid);
100 
101 		if (pid == ldape_pid) {
102 			log_info("ldapd: lost ldap server");
103 			event_loopexit(NULL);
104 			break;
105 		}
106 	}
107 }
108 
109 int
110 main(int argc, char *argv[])
111 {
112 	int			 c;
113 	int			 debug = 0, verbose = 0, eflag = 0;
114 	int			 configtest = 0;
115 	int			 pipe_parent2ldap[2];
116 	char			*conffile = CONFFILE;
117 	char			*csockpath = LDAPD_SOCKET;
118 	char			*saved_argv0;
119 	struct imsgev		*iev_ldape;
120 	struct event		 ev_sigint;
121 	struct event		 ev_sigterm;
122 	struct event		 ev_sigchld;
123 	struct event		 ev_sighup;
124 	struct stat		 sb;
125 
126 	log_init(1);		/* log to stderr until daemonized */
127 
128 	saved_argv0 = argv[0];
129 	if (saved_argv0 == NULL)
130 		saved_argv0 = "ldapd";
131 
132 	while ((c = getopt(argc, argv, "dhvD:f:nr:s:E")) != -1) {
133 
134 		switch (c) {
135 		case 'd':
136 			debug = 1;
137 			break;
138 		case 'D':
139 			if (cmdline_symset(optarg) < 0) {
140 				warnx("could not parse macro definition %s",
141 				    optarg);
142 			}
143 			break;
144 		case 'f':
145 			conffile = optarg;
146 			break;
147 		case 'h':
148 			usage();
149 			/* NOTREACHED */
150 		case 'n':
151 			configtest = 1;
152 			break;
153 		case 'r':
154 			datadir = optarg;
155 			break;
156 		case 's':
157 			csockpath = optarg;
158 			break;
159 		case 'v':
160 			verbose++;
161 			break;
162 		case 'E':
163 			eflag = 1;
164 			break;
165 		default:
166 			usage();
167 			/* NOTREACHED */
168 		}
169 	}
170 
171 	argc -= optind;
172 	if (argc > 0)
173 		usage();
174 
175 	/* check for root privileges  */
176 	if (geteuid())
177 		errx(1, "need root privileges");
178 
179 	/* check for ldapd user */
180 	if (getpwnam(LDAPD_USER) == NULL)
181 		errx(1, "unknown user %s", LDAPD_USER);
182 
183 	log_verbose(verbose);
184 	stats.started_at = time(0);
185 	tls_init();
186 
187 	if (parse_config(conffile) != 0)
188 		exit(2);
189 
190 	if (configtest) {
191 		fprintf(stderr, "configuration ok\n");
192 		exit(0);
193 	}
194 
195 	if (eflag)
196 		ldape(debug, verbose, csockpath);
197 
198 	if (stat(datadir, &sb) == -1)
199 		err(1, "%s", datadir);
200 	if (!S_ISDIR(sb.st_mode))
201 		errx(1, "%s is not a directory", datadir);
202 
203 	if (!debug) {
204 		if (daemon(1, 0) == -1)
205 			err(1, "failed to daemonize");
206 	}
207 
208 	log_init(debug);
209 	log_info("startup");
210 
211 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
212 	    PF_UNSPEC, pipe_parent2ldap) != 0)
213 		fatal("socketpair");
214 
215 	ldape_pid = start_child(PROC_LDAP_SERVER, saved_argv0,
216 	    pipe_parent2ldap[1], debug, verbose, csockpath, conffile);
217 
218 	setproctitle("auth");
219 	event_init();
220 
221 	signal_set(&ev_sigint, SIGINT, ldapd_sig_handler, NULL);
222 	signal_set(&ev_sigterm, SIGTERM, ldapd_sig_handler, NULL);
223 	signal_set(&ev_sigchld, SIGCHLD, ldapd_sigchld_handler, NULL);
224 	signal_set(&ev_sighup, SIGHUP, ldapd_sig_handler, NULL);
225 	signal_add(&ev_sigint, NULL);
226 	signal_add(&ev_sigterm, NULL);
227 	signal_add(&ev_sigchld, NULL);
228 	signal_add(&ev_sighup, NULL);
229 	signal(SIGPIPE, SIG_IGN);
230 
231 	if ((iev_ldape = calloc(1, sizeof(struct imsgev))) == NULL)
232 		fatal("calloc");
233 	imsgev_init(iev_ldape, pipe_parent2ldap[0], NULL, ldapd_imsgev,
234 	    ldapd_needfd);
235 
236 	if (pledge("stdio rpath wpath cpath getpw sendfd proc exec",
237 	    NULL) == -1)
238 		err(1, "pledge");
239 
240 	event_dispatch();
241 
242 	ldapd_cleanup(csockpath);
243 	log_debug("ldapd: exiting");
244 
245 	return 0;
246 }
247 
248 static void
249 ldapd_cleanup(char * csockpath)
250 {
251 	struct listener		*l;
252 	struct sockaddr_un	*sun = NULL;
253 
254 	/* Remove control socket. */
255 	(void)unlink(csockpath);
256 
257 	/* Remove unix listening sockets. */
258 	TAILQ_FOREACH(l, &conf->listeners, entry) {
259 		if (l->ss.ss_family == AF_UNIX) {
260 			sun = (struct sockaddr_un *)&l->ss;
261 			log_info("ldapd: removing unix socket %s", sun->sun_path);
262 			(void)unlink(sun->sun_path);
263 		}
264 	}
265 }
266 
267 static void
268 ldapd_imsgev(struct imsgev *iev, int code, struct imsg *imsg)
269 {
270 	switch (code) {
271 	case IMSGEV_IMSG:
272 		log_debug("%s: got imsg %d on fd %d",
273 		    __func__, imsg->hdr.type, iev->ibuf.fd);
274 		switch (imsg->hdr.type) {
275 		case IMSG_LDAPD_AUTH:
276 			ldapd_auth_request(iev, imsg);
277 			break;
278 		case IMSG_CTL_LOG_VERBOSE:
279 			ldapd_log_verbose(imsg);
280 			break;
281 		case IMSG_LDAPD_OPEN:
282 			ldapd_open_request(iev, imsg);
283 			break;
284 		default:
285 			log_debug("%s: unexpected imsg %d",
286 			    __func__, imsg->hdr.type);
287 			break;
288 		}
289 		break;
290 	case IMSGEV_EREAD:
291 	case IMSGEV_EWRITE:
292 	case IMSGEV_EIMSG:
293 		fatal("imsgev read/write error");
294 		break;
295 	case IMSGEV_DONE:
296 		event_loopexit(NULL);
297 		break;
298 	}
299 }
300 
301 static void
302 ldapd_needfd(struct imsgev *iev)
303 {
304 	fatal("should never need an fd for parent messages");
305 }
306 
307 static int
308 ldapd_auth_classful(char *name, char *password)
309 {
310 	login_cap_t		*lc = NULL;
311 	char			*class = NULL, *style = NULL;
312 	auth_session_t		*as;
313 
314 	if ((class = strchr(name, '#')) == NULL) {
315 		log_debug("regular auth");
316 		return auth_userokay(name, NULL, "auth-ldap", password);
317 	}
318 	*class++ = '\0';
319 
320 	if ((lc = login_getclass(class)) == NULL) {
321 		log_debug("login_getclass(%s) for [%s] failed", class, name);
322 		return 0;
323 	}
324 	if ((style = login_getstyle(lc, style, "auth-ldap")) == NULL) {
325 		log_debug("login_getstyle() for [%s] failed", name);
326 		login_close(lc);
327 		return 0;
328 	}
329 	if (password) {
330 		if ((as = auth_open()) == NULL) {
331 			login_close(lc);
332 			return 0;
333 		}
334 		auth_setitem(as, AUTHV_SERVICE, "response");
335 		auth_setdata(as, "", 1);
336 		auth_setdata(as, password, strlen(password) + 1);
337 		explicit_bzero(password, strlen(password));
338 	} else
339 		as = NULL;
340 
341 	as = auth_verify(as, style, name, lc->lc_class, (char *)NULL);
342 	login_close(lc);
343 	return (as != NULL ? auth_close(as) : 0);
344 }
345 
346 static void
347 ldapd_auth_request(struct imsgev *iev, struct imsg *imsg)
348 {
349 	struct auth_req		*areq = imsg->data;
350 	struct auth_res		 ares;
351 
352 	if (imsg->hdr.len != sizeof(*areq) + IMSG_HEADER_SIZE)
353 		fatal("invalid size of auth request");
354 
355 	/* make sure name and password are null-terminated */
356 	areq->name[sizeof(areq->name) - 1] = '\0';
357 	areq->password[sizeof(areq->password) - 1] = '\0';
358 
359 	log_debug("authenticating [%s]", areq->name);
360 	ares.ok = ldapd_auth_classful(areq->name, areq->password);
361 	ares.fd = areq->fd;
362 	ares.msgid = areq->msgid;
363 	memset(areq, 0, sizeof(*areq));
364 	imsgev_compose(iev, IMSG_LDAPD_AUTH_RESULT, 0, 0, -1, &ares,
365 	    sizeof(ares));
366 }
367 
368 static void
369 ldapd_log_verbose(struct imsg *imsg)
370 {
371 	int	 verbose;
372 
373 	if (imsg->hdr.len != sizeof(verbose) + IMSG_HEADER_SIZE)
374 		fatal("invalid size of log verbose request");
375 
376 	bcopy(imsg->data, &verbose, sizeof(verbose));
377 	log_verbose(verbose);
378 }
379 
380 static void
381 ldapd_open_request(struct imsgev *iev, struct imsg *imsg)
382 {
383 	struct open_req		*oreq = imsg->data;
384 	int			 oflags, fd;
385 
386 	if (imsg->hdr.len != sizeof(*oreq) + IMSG_HEADER_SIZE)
387 		fatal("invalid size of open request");
388 
389 	/* make sure path is null-terminated */
390 	oreq->path[PATH_MAX] = '\0';
391 
392 	if (strncmp(oreq->path, datadir, strlen(datadir)) != 0) {
393 		log_warnx("refusing to open file %s", oreq->path);
394 		fatal("ldape sent invalid open request");
395 	}
396 
397 	if (oreq->rdonly)
398 		oflags = O_RDONLY;
399 	else
400 		oflags = O_RDWR | O_CREAT | O_APPEND;
401 
402 	log_debug("opening [%s]", oreq->path);
403 	fd = open(oreq->path, oflags | O_NOFOLLOW, 0600);
404 	if (fd == -1)
405 		log_warn("%s", oreq->path);
406 
407 	imsgev_compose(iev, IMSG_LDAPD_OPEN_RESULT, 0, 0, fd, oreq,
408 	    sizeof(*oreq));
409 }
410 
411 static pid_t
412 start_child(enum ldapd_process p, char *argv0, int fd, int debug,
413     int verbose, char *csockpath, char *conffile)
414 {
415 	char		*argv[9];
416 	int		 argc = 0;
417 	pid_t		 pid;
418 
419 	switch (pid = fork()) {
420 	case -1:
421 		fatal("cannot fork");
422 	case 0:
423 		break;
424 	default:
425 		close(fd);
426 		return (pid);
427 	}
428 
429 	if (dup2(fd, PROC_PARENT_SOCK_FILENO) == -1)
430 		fatal("cannot setup imsg fd");
431 
432 	argv[argc++] = argv0;
433 	switch (p) {
434 	case PROC_MAIN_AUTH:
435 		fatalx("Can not start main process");
436 	case PROC_LDAP_SERVER:
437 		argv[argc++] = "-E";
438 		break;
439 	}
440 	if (debug)
441 		argv[argc++] = "-d";
442 	if (verbose)
443 		argv[argc++] = "-v";
444 	if (csockpath) {
445 		argv[argc++] = "-s";
446 		argv[argc++] = csockpath;
447 	}
448 	if (conffile) {
449 		argv[argc++] = "-f";
450 		argv[argc++] = conffile;
451 	}
452 
453 	argv[argc++] = NULL;
454 
455 	execvp(argv0, argv);
456 	fatal("execvp");
457 }
458