xref: /freebsd/usr.sbin/rpc.umntall/mounttab.c (revision ab40f58ccfe6c07ebefddc72f4661a52fe746353)
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("$FreeBSD$");
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 
48 struct mtablist *mtabhead;
49 
50 static 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  */
56 int
57 add_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  */
74 int
75 read_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  */
143 int
144 write_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  */
187 void
188 clean_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  */
213 void
214 free_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  */
227 static void
228 badline(const char *field, const char *bad)
229 {
230 	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
231 	    (bad == NULL) ? "<null>" : bad);
232 }
233