xref: /freebsd/usr.sbin/rpc.umntall/mounttab.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #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 
46 struct mtablist *mtabhead;
47 
48 static 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  */
54 int
55 add_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  */
72 int
73 read_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  */
141 int
142 write_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  */
185 void
186 clean_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  */
211 void
212 free_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  */
225 static void
226 badline(const char *field, const char *bad)
227 {
228 	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
229 	    (bad == NULL) ? "<null>" : bad);
230 }
231