1/*
2 * Copyright (c) 1999 Martin Blapp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#include <sys/syslog.h>
32
33#include <rpc/rpc.h>
34#include <rpcsvc/mount.h>
35
36#include <err.h>
37#include <errno.h>
38#include <limits.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#include "mounttab.h"
45
46struct mtablist *mtabhead;
47
48static void badline(const char *field, const char *bad);
49
50/*
51 * Add an entry to PATH_MOUNTTAB for each mounted NFS filesystem,
52 * so the client can notify the NFS server even after reboot.
53 */
54int
55add_mtab(char *hostp, char *dirp)
56{
57	FILE *mtabfile;
58
59	if ((mtabfile = fopen(PATH_MOUNTTAB, "a")) == NULL)
60		return (0);
61	else {
62		fprintf(mtabfile, "%ld\t%s\t%s\n",
63		    (long)time(NULL), hostp, dirp);
64		fclose(mtabfile);
65		return (1);
66	}
67}
68
69/*
70 * Read mounttab line for line and return struct mtablist.
71 */
72int
73read_mtab(void)
74{
75	struct mtablist **mtabpp, *mtabp;
76	char *hostp, *dirp, *cp;
77	char str[STRSIZ];
78	char *timep, *endp;
79	time_t actiontime;
80	u_long ultmp;
81	FILE *mtabfile;
82
83	if ((mtabfile = fopen(PATH_MOUNTTAB, "r")) == NULL) {
84		if (errno == ENOENT)
85			return (0);
86		else {
87			syslog(LOG_ERR, "can't open %s", PATH_MOUNTTAB);
88			return (0);
89		}
90	}
91	actiontime = 0;
92	mtabpp = &mtabhead;
93	while (fgets(str, STRSIZ, mtabfile) != NULL) {
94		cp = str;
95		errno = 0;
96		if (*cp == '#' || *cp == ' ' || *cp == '\n')
97			continue;
98		timep = strsep(&cp, " \t\n");
99		if (timep == NULL || *timep == '\0') {
100			badline("time", timep);
101			continue;
102		}
103		hostp = strsep(&cp, " \t\n");
104		if (hostp == NULL || *hostp == '\0') {
105			badline("host", hostp);
106			continue;
107		}
108		dirp = strsep(&cp, " \t\n");
109		if (dirp == NULL || *dirp == '\0') {
110			badline("dir", dirp);
111			continue;
112		}
113		ultmp = strtoul(timep, &endp, 10);
114		if (ultmp == ULONG_MAX || *endp != '\0') {
115			badline("time", timep);
116			continue;
117		}
118		actiontime = ultmp;
119		if ((mtabp = malloc(sizeof (struct mtablist))) == NULL) {
120			syslog(LOG_ERR, "malloc");
121			fclose(mtabfile);
122			return (0);
123		}
124		mtabp->mtab_time = actiontime;
125		memmove(mtabp->mtab_host, hostp, MNTNAMLEN);
126		mtabp->mtab_host[MNTNAMLEN - 1] = '\0';
127		memmove(mtabp->mtab_dirp, dirp, MNTPATHLEN);
128		mtabp->mtab_dirp[MNTPATHLEN - 1] = '\0';
129		mtabp->mtab_next = (struct mtablist *)NULL;
130		*mtabpp = mtabp;
131		mtabpp = &mtabp->mtab_next;
132	}
133	fclose(mtabfile);
134	return (1);
135}
136
137/*
138 * Rewrite PATH_MOUNTTAB from scratch and skip bad entries.
139 * Unlink PATH_MOUNTAB if no entry is left.
140 */
141int
142write_mtab(int verbose)
143{
144	struct mtablist *mtabp, *mp;
145	FILE *mtabfile;
146	int line;
147
148	if ((mtabfile = fopen(PATH_MOUNTTAB, "w")) == NULL) {
149		syslog(LOG_ERR, "can't write to %s", PATH_MOUNTTAB);
150			return (0);
151	}
152	line = 0;
153	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
154		if (mtabp->mtab_host[0] == '\0')
155			continue;
156		/* Skip if a later (hence more recent) entry is identical. */
157		for (mp = mtabp->mtab_next; mp != NULL; mp = mp->mtab_next)
158			if (strcmp(mtabp->mtab_host, mp->mtab_host) == 0 &&
159			    strcmp(mtabp->mtab_dirp, mp->mtab_dirp) == 0)
160				break;
161		if (mp != NULL)
162			continue;
163
164		fprintf(mtabfile, "%ld\t%s\t%s\n",
165		    (long)mtabp->mtab_time, mtabp->mtab_host,
166		    mtabp->mtab_dirp);
167		if (verbose)
168			warnx("write mounttab entry %s:%s",
169			    mtabp->mtab_host, mtabp->mtab_dirp);
170		line++;
171	}
172	fclose(mtabfile);
173	if (line == 0) {
174		if (unlink(PATH_MOUNTTAB) == -1) {
175			syslog(LOG_ERR, "can't remove %s", PATH_MOUNTTAB);
176			return (0);
177		}
178	}
179	return (1);
180}
181
182/*
183 * Mark the entries as clean where RPC calls have been done successfully.
184 */
185void
186clean_mtab(char *hostp, char *dirp, int verbose)
187{
188	struct mtablist *mtabp;
189	char *host;
190
191	/* Copy hostp in case it points to an entry that we are zeroing out. */
192	host = strdup(hostp);
193	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
194		if (strcmp(mtabp->mtab_host, host) != 0)
195			continue;
196		if (dirp != NULL && strcmp(mtabp->mtab_dirp, dirp) != 0)
197			continue;
198
199		if (verbose)
200			warnx("delete mounttab entry%s %s:%s",
201			    (dirp == NULL) ? " by host" : "",
202			    mtabp->mtab_host, mtabp->mtab_dirp);
203		bzero(mtabp->mtab_host, MNTNAMLEN);
204	}
205	free(host);
206}
207
208/*
209 * Free struct mtablist mtab.
210 */
211void
212free_mtab(void)
213{
214	struct mtablist *mtabp;
215
216	while ((mtabp = mtabhead) != NULL) {
217		mtabhead = mtabhead->mtab_next;
218		free(mtabp);
219	}
220}
221
222/*
223 * Print bad lines to syslog.
224 */
225static void
226badline(const char *field, const char *bad)
227{
228	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
229	    (bad == NULL) ? "<null>" : bad);
230}
231