1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Martin Blapp
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: stable/11/usr.sbin/rpc.umntall/mounttab.c 330449 2018-03-05 07:26:05Z eadler $");
32
33#include <sys/syslog.h>
34
35#include <rpc/rpc.h>
36#include <rpcsvc/mount.h>
37
38#include <err.h>
39#include <errno.h>
40#include <limits.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <unistd.h>
45
46#include "mounttab.h"
47
48struct mtablist *mtabhead;
49
50static void badline(const char *field, const char *bad);
51
52/*
53 * Add an entry to PATH_MOUNTTAB for each mounted NFS filesystem,
54 * so the client can notify the NFS server even after reboot.
55 */
56int
57add_mtab(char *hostp, char *dirp)
58{
59	FILE *mtabfile;
60
61	if ((mtabfile = fopen(PATH_MOUNTTAB, "a")) == NULL)
62		return (0);
63	else {
64		fprintf(mtabfile, "%ld\t%s\t%s\n",
65		    (long)time(NULL), hostp, dirp);
66		fclose(mtabfile);
67		return (1);
68	}
69}
70
71/*
72 * Read mounttab line for line and return struct mtablist.
73 */
74int
75read_mtab(void)
76{
77	struct mtablist **mtabpp, *mtabp;
78	char *hostp, *dirp, *cp;
79	char str[STRSIZ];
80	char *timep, *endp;
81	time_t actiontime;
82	u_long ultmp;
83	FILE *mtabfile;
84
85	if ((mtabfile = fopen(PATH_MOUNTTAB, "r")) == NULL) {
86		if (errno == ENOENT)
87			return (0);
88		else {
89			syslog(LOG_ERR, "can't open %s", PATH_MOUNTTAB);
90			return (0);
91		}
92	}
93	actiontime = 0;
94	mtabpp = &mtabhead;
95	while (fgets(str, STRSIZ, mtabfile) != NULL) {
96		cp = str;
97		errno = 0;
98		if (*cp == '#' || *cp == ' ' || *cp == '\n')
99			continue;
100		timep = strsep(&cp, " \t\n");
101		if (timep == NULL || *timep == '\0') {
102			badline("time", timep);
103			continue;
104		}
105		hostp = strsep(&cp, " \t\n");
106		if (hostp == NULL || *hostp == '\0') {
107			badline("host", hostp);
108			continue;
109		}
110		dirp = strsep(&cp, " \t\n");
111		if (dirp == NULL || *dirp == '\0') {
112			badline("dir", dirp);
113			continue;
114		}
115		ultmp = strtoul(timep, &endp, 10);
116		if (ultmp == ULONG_MAX || *endp != '\0') {
117			badline("time", timep);
118			continue;
119		}
120		actiontime = ultmp;
121		if ((mtabp = malloc(sizeof (struct mtablist))) == NULL) {
122			syslog(LOG_ERR, "malloc");
123			fclose(mtabfile);
124			return (0);
125		}
126		mtabp->mtab_time = actiontime;
127		memmove(mtabp->mtab_host, hostp, MNTNAMLEN);
128		mtabp->mtab_host[MNTNAMLEN - 1] = '\0';
129		memmove(mtabp->mtab_dirp, dirp, MNTPATHLEN);
130		mtabp->mtab_dirp[MNTPATHLEN - 1] = '\0';
131		mtabp->mtab_next = (struct mtablist *)NULL;
132		*mtabpp = mtabp;
133		mtabpp = &mtabp->mtab_next;
134	}
135	fclose(mtabfile);
136	return (1);
137}
138
139/*
140 * Rewrite PATH_MOUNTTAB from scratch and skip bad entries.
141 * Unlink PATH_MOUNTAB if no entry is left.
142 */
143int
144write_mtab(int verbose)
145{
146	struct mtablist *mtabp, *mp;
147	FILE *mtabfile;
148	int line;
149
150	if ((mtabfile = fopen(PATH_MOUNTTAB, "w")) == NULL) {
151		syslog(LOG_ERR, "can't write to %s", PATH_MOUNTTAB);
152			return (0);
153	}
154	line = 0;
155	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
156		if (mtabp->mtab_host[0] == '\0')
157			continue;
158		/* Skip if a later (hence more recent) entry is identical. */
159		for (mp = mtabp->mtab_next; mp != NULL; mp = mp->mtab_next)
160			if (strcmp(mtabp->mtab_host, mp->mtab_host) == 0 &&
161			    strcmp(mtabp->mtab_dirp, mp->mtab_dirp) == 0)
162				break;
163		if (mp != NULL)
164			continue;
165
166		fprintf(mtabfile, "%ld\t%s\t%s\n",
167		    (long)mtabp->mtab_time, mtabp->mtab_host,
168		    mtabp->mtab_dirp);
169		if (verbose)
170			warnx("write mounttab entry %s:%s",
171			    mtabp->mtab_host, mtabp->mtab_dirp);
172		line++;
173	}
174	fclose(mtabfile);
175	if (line == 0) {
176		if (unlink(PATH_MOUNTTAB) == -1) {
177			syslog(LOG_ERR, "can't remove %s", PATH_MOUNTTAB);
178			return (0);
179		}
180	}
181	return (1);
182}
183
184/*
185 * Mark the entries as clean where RPC calls have been done successfully.
186 */
187void
188clean_mtab(char *hostp, char *dirp, int verbose)
189{
190	struct mtablist *mtabp;
191	char *host;
192
193	/* Copy hostp in case it points to an entry that we are zeroing out. */
194	host = strdup(hostp);
195	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
196		if (strcmp(mtabp->mtab_host, host) != 0)
197			continue;
198		if (dirp != NULL && strcmp(mtabp->mtab_dirp, dirp) != 0)
199			continue;
200
201		if (verbose)
202			warnx("delete mounttab entry%s %s:%s",
203			    (dirp == NULL) ? " by host" : "",
204			    mtabp->mtab_host, mtabp->mtab_dirp);
205		bzero(mtabp->mtab_host, MNTNAMLEN);
206	}
207	free(host);
208}
209
210/*
211 * Free struct mtablist mtab.
212 */
213void
214free_mtab(void)
215{
216	struct mtablist *mtabp;
217
218	while ((mtabp = mtabhead) != NULL) {
219		mtabhead = mtabhead->mtab_next;
220		free(mtabp);
221	}
222}
223
224/*
225 * Print bad lines to syslog.
226 */
227static void
228badline(const char *field, const char *bad)
229{
230	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
231	    (bad == NULL) ? "<null>" : bad);
232}
233