xref: /freebsd/usr.sbin/rpc.umntall/mounttab.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
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 #ifndef lint
29 static const char rcsid[] =
30   "$FreeBSD$";
31 #endif /* not lint */
32 
33 #include <sys/syslog.h>
34 
35 #include <rpc/rpc.h>
36 #include <nfs/rpcv2.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(char *field, 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 	FILE *mtabfile;
59 
60 	if ((mtabfile = fopen(PATH_MOUNTTAB, "a")) == NULL)
61 		return (0);
62 	else {
63 		fprintf(mtabfile, "%ld\t%s\t%s\n",
64 		    (long)time(NULL), hostp, dirp);
65 		fclose(mtabfile);
66 		return (1);
67 	}
68 }
69 
70 /*
71  * Read mounttab line for line and return struct mtablist.
72  */
73 int
74 read_mtab() {
75 	struct mtablist **mtabpp, *mtabp;
76 	char *hostp, *dirp, *cp;
77 	char str[STRSIZ];
78 	char *timep, *endp;
79 	time_t time;
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 	time = 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 		time = 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 = time;
125 		memmove(mtabp->mtab_host, hostp, RPCMNT_NAMELEN);
126 		mtabp->mtab_host[RPCMNT_NAMELEN - 1] = '\0';
127 		memmove(mtabp->mtab_dirp, dirp, RPCMNT_PATHLEN);
128 		mtabp->mtab_dirp[RPCMNT_PATHLEN - 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 	struct mtablist *mtabp, *mp;
144 	FILE *mtabfile;
145 	int line;
146 
147 	if ((mtabfile = fopen(PATH_MOUNTTAB, "w")) == NULL) {
148 		syslog(LOG_ERR, "can't write to %s", PATH_MOUNTTAB);
149 			return (0);
150 	}
151 	line = 0;
152 	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
153 		if (mtabp->mtab_host[0] == '\0')
154 			continue;
155 		/* Skip if a later (hence more recent) entry is identical. */
156 		for (mp = mtabp->mtab_next; mp != NULL; mp = mp->mtab_next)
157 			if (strcmp(mtabp->mtab_host, mp->mtab_host) == 0 &&
158 			    strcmp(mtabp->mtab_dirp, mp->mtab_dirp) == 0)
159 				break;
160 		if (mp != NULL)
161 			continue;
162 
163 		fprintf(mtabfile, "%ld\t%s\t%s\n",
164 		    (long)mtabp->mtab_time, mtabp->mtab_host,
165 		    mtabp->mtab_dirp);
166 		if (verbose)
167 			warnx("write mounttab entry %s:%s",
168 			    mtabp->mtab_host, mtabp->mtab_dirp);
169 		line++;
170 	}
171 	fclose(mtabfile);
172 	if (line == 0) {
173 		if (unlink(PATH_MOUNTTAB) == -1) {
174 			syslog(LOG_ERR, "can't remove %s", PATH_MOUNTTAB);
175 			return (0);
176 		}
177 	}
178 	return (1);
179 }
180 
181 /*
182  * Mark the entries as clean where RPC calls have been done successfully.
183  */
184 void
185 clean_mtab(char *hostp, char *dirp, int verbose) {
186 	struct mtablist *mtabp;
187 	char *host;
188 
189 	/* Copy hostp in case it points to an entry that we are zeroing out. */
190 	host = strdup(hostp);
191 	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
192 		if (strcmp(mtabp->mtab_host, host) != 0)
193 			continue;
194 		if (dirp != NULL && strcmp(mtabp->mtab_dirp, dirp) != 0)
195 			continue;
196 
197 		if (verbose)
198 			warnx("delete mounttab entry%s %s:%s",
199 			    (dirp == NULL) ? " by host" : "",
200 			    mtabp->mtab_host, mtabp->mtab_dirp);
201 		bzero(mtabp->mtab_host, RPCMNT_NAMELEN);
202 	}
203 	free(host);
204 }
205 
206 /*
207  * Free struct mtablist mtab.
208  */
209 void
210 free_mtab() {
211 	struct mtablist *mtabp;
212 
213 	while ((mtabp = mtabhead) != NULL) {
214 		mtabhead = mtabhead->mtab_next;
215 		free(mtabp);
216 	}
217 }
218 
219 /*
220  * Print bad lines to syslog.
221  */
222 static void
223 badline(char *field, char *bad) {
224 	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
225 	    (bad == NULL) ? "<null>" : bad);
226 }
227