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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.sbin/cron/database.c	Lines:	0	90	0.0 %
Date:	2017-11-13	Branches:	0	96	0.0 %


/*	$OpenBSD: database.c,v 1.36 2017/10/25 17:08:58 jca Exp $	*/

/* Copyright 1988,1990,1993,1994 by Paul Vixie
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <bitstring.h>		/* for structs.h */
#include <dirent.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>		/* for structs.h */
#include <unistd.h>

#include "pathnames.h"
#include "globals.h"
#include "macros.h"
#include "structs.h"
#include "funcs.h"

#define HASH(a,b) ((a)+(b))

static	void		process_crontab(int, const char *, const char *,
					struct stat *, cron_db *, cron_db *);

void
load_database(cron_db **db)
{
	struct stat statbuf, syscron_stat;
	cron_db *new_db, *old_db = *db;
	struct timespec mtime;
	struct dirent *dp;
	DIR *dir;
	user *u;

	/* before we start loading any data, do a stat on _PATH_CRON_SPOOL
	 * so that if anything changes as of this moment (i.e., before we've
	 * cached any of the database), we'll see the changes next time.
	 */
	if (stat(_PATH_CRON_SPOOL, &statbuf) < 0) {
		syslog(LOG_ERR, "(CRON) STAT FAILED (%s)", _PATH_CRON_SPOOL);
		return;
	}

	/* track system crontab file
	 */
	if (stat(_PATH_SYS_CRONTAB, &syscron_stat) < 0)
		timespecclear(&syscron_stat.st_mtim);

	/* hash mtime of system crontab file and crontab dir
	 */
	mtime.tv_sec =
	    HASH(statbuf.st_mtim.tv_sec, syscron_stat.st_mtim.tv_sec);
	mtime.tv_nsec =
	    HASH(statbuf.st_mtim.tv_nsec, syscron_stat.st_mtim.tv_nsec);

	/* if spooldir's mtime has not changed, we don't need to fiddle with
	 * the database.
	 */
	if (old_db != NULL && timespeccmp(&mtime, &old_db->mtime, ==))
		return;

	/* something's different.  make a new database, moving unchanged
	 * elements from the old database, reloading elements that have
	 * actually changed.  Whatever is left in the old database when
	 * we're done is chaff -- crontabs that disappeared.
	 */
	if ((new_db = malloc(sizeof(*new_db))) == NULL)
		return;
	new_db->mtime = mtime;
	TAILQ_INIT(&new_db->users);

	if (timespecisset(&syscron_stat.st_mtim)) {
		process_crontab(AT_FDCWD, "*system*", _PATH_SYS_CRONTAB,
				&syscron_stat, new_db, old_db);
	}

	/* we used to keep this dir open all the time, for the sake of
	 * efficiency.  however, we need to close it in every fork, and
	 * we fork a lot more often than the mtime of the dir changes.
	 */
	if (!(dir = opendir(_PATH_CRON_SPOOL))) {
		syslog(LOG_ERR, "(CRON) OPENDIR FAILED (%s)", _PATH_CRON_SPOOL);
		/* Restore system crontab entry as needed. */
		if (!TAILQ_EMPTY(&new_db->users) &&
		    (u = TAILQ_FIRST(&old_db->users))) {
			if (strcmp(u->name, "*system*") == 0) {
				TAILQ_REMOVE(&old_db->users, u, entries);
				free_user(u);
				TAILQ_INSERT_HEAD(&old_db->users,
				    TAILQ_FIRST(&new_db->users), entries);
			}
		}
		free(new_db);
		return;
	}

	while (NULL != (dp = readdir(dir))) {
		/* avoid file names beginning with ".".  this is good
		 * because we would otherwise waste two guaranteed calls
		 * to getpwnam() for . and .., and also because user names
		 * starting with a period are just too nasty to consider.
		 */
		if (dp->d_name[0] == '.')
			continue;

		process_crontab(dirfd(dir), dp->d_name, dp->d_name,
				&statbuf, new_db, old_db);
	}
	closedir(dir);

	/* if we don't do this, then when our children eventually call
	 * getpwnam() in do_command.c's child_process to verify MAILTO=,
	 * they will screw us up (and v-v).
	 */
	endpwent();

	/* whatever's left in the old database is now junk.
	 */
	if (old_db != NULL) {
		while ((u = TAILQ_FIRST(&old_db->users))) {
			TAILQ_REMOVE(&old_db->users, u, entries);
			free_user(u);
		}
		free(old_db);
	}

	/* overwrite the database control block with the new one.
	 */
	*db = new_db;
}

user *
find_user(cron_db *db, const char *name)
{
	user *u = NULL;

	if (db != NULL) {
		TAILQ_FOREACH(u, &db->users, entries) {
			if (strcmp(u->name, name) == 0)
				break;
		}
	}
	return (u);
}

static void
process_crontab(int dfd, const char *uname, const char *fname,
		struct stat *statbuf, cron_db *new_db, cron_db *old_db)
{
	struct passwd *pw = NULL;
	int crontab_fd = -1;
	user *u, *new_u;
	mode_t tabmask, tabperm;

	/* Note: pw must remain NULL for system crontab (see below). */
	if (fname[0] != '/' && (pw = getpwnam(uname)) == NULL) {
		/* file doesn't have a user in passwd file.
		 */
		syslog(LOG_WARNING, "(%s) ORPHAN (no passwd entry)", uname);
		goto next_crontab;
	}

	crontab_fd = openat(dfd, fname,
	    O_RDONLY|O_NONBLOCK|O_NOFOLLOW|O_CLOEXEC);
	if (crontab_fd < 0) {
		/* crontab not accessible?
		 */
		syslog(LOG_ERR, "(%s) CAN'T OPEN (%s)", uname, fname);
		goto next_crontab;
	}

	if (fstat(crontab_fd, statbuf) < 0) {
		syslog(LOG_ERR, "(%s) FSTAT FAILED (%s)", uname, fname);
		goto next_crontab;
	}
	if (!S_ISREG(statbuf->st_mode)) {
		syslog(LOG_WARNING, "(%s) NOT REGULAR (%s)", uname, fname);
		goto next_crontab;
	}
	/* Looser permissions on system crontab. */
	tabmask = pw ? ALLPERMS : (ALLPERMS & ~(S_IWUSR|S_IRGRP|S_IROTH));
	tabperm = pw ? (S_IRUSR|S_IWUSR) : S_IRUSR;
	if ((statbuf->st_mode & tabmask) != tabperm) {
		syslog(LOG_WARNING, "(%s) BAD FILE MODE (%s)", uname, fname);
		goto next_crontab;
	}
	if (statbuf->st_uid != 0 && (pw == NULL ||
	    statbuf->st_uid != pw->pw_uid || strcmp(uname, pw->pw_name) != 0)) {
		syslog(LOG_WARNING, "(%s) WRONG FILE OWNER (%s)", uname, fname);
		goto next_crontab;
	}
	if (pw != NULL && statbuf->st_gid != cron_gid) {
		syslog(LOG_WARNING, "(%s) WRONG FILE GROUP (%s)", uname, fname);
		goto next_crontab;
	}
	if (pw != NULL && statbuf->st_nlink != 1) {
		syslog(LOG_WARNING, "(%s) BAD LINK COUNT (%s)", uname, fname);
		goto next_crontab;
	}

	u = find_user(old_db, fname);
	if (u != NULL) {
		/* if crontab has not changed since we last read it
		 * in, then we can just use our existing entry.
		 */
		if (timespeccmp(&u->mtime, &statbuf->st_mtim, ==)) {
			TAILQ_REMOVE(&old_db->users, u, entries);
			TAILQ_INSERT_TAIL(&new_db->users, u, entries);
			goto next_crontab;
		}
		syslog(LOG_INFO, "(%s) RELOAD (%s)", uname, fname);
	}

	new_u = load_user(crontab_fd, pw, fname);
	if (new_u != NULL) {
		/* Insert user into the new database and remove from old. */
		new_u->mtime = statbuf->st_mtim;
		TAILQ_INSERT_TAIL(&new_db->users, new_u, entries);
		if (u != NULL) {
			TAILQ_REMOVE(&old_db->users, u, entries);
			free_user(u);
		}
	} else if (u != NULL) {
		/* New user crontab failed to load, preserve the old one. */
		TAILQ_REMOVE(&old_db->users, u, entries);
		TAILQ_INSERT_TAIL(&new_db->users, u, entries);
	}

 next_crontab:
	if (crontab_fd >= 0) {
		close(crontab_fd);
	}
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: database.c,v 1.36 2017/10/25 17:08:58 jca Exp $ */
2
3			/* Copyright 1988,1990,1993,1994 by Paul Vixie
4			* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5			* Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
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 ISC DISCLAIMS ALL WARRANTIES
12			* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13			* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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
17			* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18			*/
19
20			#include <sys/types.h>
21			#include <sys/stat.h>
22			#include <sys/time.h>
23
24			#include <bitstring.h> /* for structs.h */
25			#include <dirent.h>
26			#include <fcntl.h>
27			#include <limits.h>
28			#include <pwd.h>
29			#include <stdio.h>
30			#include <stdlib.h>
31			#include <string.h>
32			#include <syslog.h>
33			#include <time.h> /* for structs.h */
34			#include <unistd.h>
35
36			#include "pathnames.h"
37			#include "globals.h"
38			#include "macros.h"
39			#include "structs.h"
40			#include "funcs.h"
41
42			#define HASH(a,b) ((a)+(b))
43
44			static void process_crontab(int, const char , const char ,
45			struct stat , cron_db , cron_db *);
46
47			void
48			load_database(cron_db **db)
49			{
50			struct stat statbuf, syscron_stat;
51			cron_db new_db, old_db = *db;
52			struct timespec mtime;
53			struct dirent *dp;
54			DIR *dir;
55			user *u;
56
57			/* before we start loading any data, do a stat on _PATH_CRON_SPOOL
58			* so that if anything changes as of this moment (i.e., before we've
59			* cached any of the database), we'll see the changes next time.
60			*/
61			if (stat(_PATH_CRON_SPOOL, &statbuf) < 0) {
62			syslog(LOG_ERR, "(CRON) STAT FAILED (%s)", _PATH_CRON_SPOOL);
63			return;
64			}
65
66			/* track system crontab file
67			*/
68			if (stat(_PATH_SYS_CRONTAB, &syscron_stat) < 0)
69			timespecclear(&syscron_stat.st_mtim);
70
71			/* hash mtime of system crontab file and crontab dir
72			*/
73			mtime.tv_sec =
74			HASH(statbuf.st_mtim.tv_sec, syscron_stat.st_mtim.tv_sec);
75			mtime.tv_nsec =
76			HASH(statbuf.st_mtim.tv_nsec, syscron_stat.st_mtim.tv_nsec);
77
78			/* if spooldir's mtime has not changed, we don't need to fiddle with
79			* the database.
80			*/
81			if (old_db != NULL && timespeccmp(&mtime, &old_db->mtime, ==))
82			return;
83
84			/* something's different. make a new database, moving unchanged
85			* elements from the old database, reloading elements that have
86			* actually changed. Whatever is left in the old database when
87			* we're done is chaff -- crontabs that disappeared.
88			*/
89			if ((new_db = malloc(sizeof(*new_db))) == NULL)
90			return;
91			new_db->mtime = mtime;
92			TAILQ_INIT(&new_db->users);
93
94			if (timespecisset(&syscron_stat.st_mtim)) {
95			process_crontab(AT_FDCWD, "system", _PATH_SYS_CRONTAB,
96			&syscron_stat, new_db, old_db);
97			}
98
99			/* we used to keep this dir open all the time, for the sake of
100			* efficiency. however, we need to close it in every fork, and
101			* we fork a lot more often than the mtime of the dir changes.
102			*/
103			if (!(dir = opendir(_PATH_CRON_SPOOL))) {
104			syslog(LOG_ERR, "(CRON) OPENDIR FAILED (%s)", _PATH_CRON_SPOOL);
105			/* Restore system crontab entry as needed. */
106			if (!TAILQ_EMPTY(&new_db->users) &&
107			(u = TAILQ_FIRST(&old_db->users))) {
108			if (strcmp(u->name, "system") == 0) {
109			TAILQ_REMOVE(&old_db->users, u, entries);
110			free_user(u);
111			TAILQ_INSERT_HEAD(&old_db->users,
112			TAILQ_FIRST(&new_db->users), entries);
113			}
114			}
115			free(new_db);
116			return;
117			}
118
119			while (NULL != (dp = readdir(dir))) {
120			/* avoid file names beginning with ".". this is good
121			* because we would otherwise waste two guaranteed calls
122			* to getpwnam() for . and .., and also because user names
123			* starting with a period are just too nasty to consider.
124			*/
125			if (dp->d_name[0] == '.')
126			continue;
127
128			process_crontab(dirfd(dir), dp->d_name, dp->d_name,
129			&statbuf, new_db, old_db);
130			}
131			closedir(dir);
132
133			/* if we don't do this, then when our children eventually call
134			* getpwnam() in do_command.c's child_process to verify MAILTO=,
135			* they will screw us up (and v-v).
136			*/
137			endpwent();
138
139			/* whatever's left in the old database is now junk.
140			*/
141			if (old_db != NULL) {
142			while ((u = TAILQ_FIRST(&old_db->users))) {
143			TAILQ_REMOVE(&old_db->users, u, entries);
144			free_user(u);
145			}
146			free(old_db);
147			}
148
149			/* overwrite the database control block with the new one.
150			*/
151			*db = new_db;
152			}
153
154			user *
155			find_user(cron_db db, const char name)
156			{
157			user *u = NULL;
158
159			if (db != NULL) {
160			TAILQ_FOREACH(u, &db->users, entries) {
161			if (strcmp(u->name, name) == 0)
162			break;
163			}
164			}
165			return (u);
166			}
167
168			static void
169			process_crontab(int dfd, const char uname, const char fname,
170			struct stat statbuf, cron_db new_db, cron_db *old_db)
171			{
172			struct passwd *pw = NULL;
173			int crontab_fd = -1;
174			user u, new_u;
175			mode_t tabmask, tabperm;
176
177			/* Note: pw must remain NULL for system crontab (see below). */
178			if (fname[0] != '/' && (pw = getpwnam(uname)) == NULL) {
179			/* file doesn't have a user in passwd file.
180			*/
181			syslog(LOG_WARNING, "(%s) ORPHAN (no passwd entry)", uname);
182			goto next_crontab;
183			}
184
185			crontab_fd = openat(dfd, fname,
186			O_RDONLY\|O_NONBLOCK\|O_NOFOLLOW\|O_CLOEXEC);
187			if (crontab_fd < 0) {
188			/* crontab not accessible?
189			*/
190			syslog(LOG_ERR, "(%s) CAN'T OPEN (%s)", uname, fname);
191			goto next_crontab;
192			}
193
194			if (fstat(crontab_fd, statbuf) < 0) {
195			syslog(LOG_ERR, "(%s) FSTAT FAILED (%s)", uname, fname);
196			goto next_crontab;
197			}
198			if (!S_ISREG(statbuf->st_mode)) {
199			syslog(LOG_WARNING, "(%s) NOT REGULAR (%s)", uname, fname);
200			goto next_crontab;
201			}
202			/* Looser permissions on system crontab. */
203			tabmask = pw ? ALLPERMS : (ALLPERMS & ~(S_IWUSR\|S_IRGRP\|S_IROTH));
204			tabperm = pw ? (S_IRUSR\|S_IWUSR) : S_IRUSR;
205			if ((statbuf->st_mode & tabmask) != tabperm) {
206			syslog(LOG_WARNING, "(%s) BAD FILE MODE (%s)", uname, fname);
207			goto next_crontab;
208			}
209			if (statbuf->st_uid != 0 && (pw == NULL \|\|
210			statbuf->st_uid != pw->pw_uid \|\| strcmp(uname, pw->pw_name) != 0)) {
211			syslog(LOG_WARNING, "(%s) WRONG FILE OWNER (%s)", uname, fname);
212			goto next_crontab;
213			}
214			if (pw != NULL && statbuf->st_gid != cron_gid) {
215			syslog(LOG_WARNING, "(%s) WRONG FILE GROUP (%s)", uname, fname);
216			goto next_crontab;
217			}
218			if (pw != NULL && statbuf->st_nlink != 1) {
219			syslog(LOG_WARNING, "(%s) BAD LINK COUNT (%s)", uname, fname);
220			goto next_crontab;
221			}
222
223			u = find_user(old_db, fname);
224			if (u != NULL) {
225			/* if crontab has not changed since we last read it
226			* in, then we can just use our existing entry.
227			*/
228			if (timespeccmp(&u->mtime, &statbuf->st_mtim, ==)) {
229			TAILQ_REMOVE(&old_db->users, u, entries);
230			TAILQ_INSERT_TAIL(&new_db->users, u, entries);
231			goto next_crontab;
232			}
233			syslog(LOG_INFO, "(%s) RELOAD (%s)", uname, fname);
234			}
235
236			new_u = load_user(crontab_fd, pw, fname);
237			if (new_u != NULL) {
238			/* Insert user into the new database and remove from old. */
239			new_u->mtime = statbuf->st_mtim;
240			TAILQ_INSERT_TAIL(&new_db->users, new_u, entries);
241			if (u != NULL) {
242			TAILQ_REMOVE(&old_db->users, u, entries);
243			free_user(u);
244			}
245			} else if (u != NULL) {
246			/* New user crontab failed to load, preserve the old one. */
247			TAILQ_REMOVE(&old_db->users, u, entries);
248			TAILQ_INSERT_TAIL(&new_db->users, u, entries);
249			}
250
251			next_crontab:
252			if (crontab_fd >= 0) {
253			close(crontab_fd);
254			}
255			}