xref: /freebsd/usr.sbin/rpc.umntall/mounttab.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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 <nfs/rpcv2.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(char *field, 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 	FILE *mtabfile;
57 
58 	if ((mtabfile = fopen(PATH_MOUNTTAB, "a")) == NULL)
59 		return (0);
60 	else {
61 		fprintf(mtabfile, "%ld\t%s\t%s\n",
62 		    (long)time(NULL), hostp, dirp);
63 		fclose(mtabfile);
64 		return (1);
65 	}
66 }
67 
68 /*
69  * Read mounttab line for line and return struct mtablist.
70  */
71 int
72 read_mtab() {
73 	struct mtablist **mtabpp, *mtabp;
74 	char *hostp, *dirp, *cp;
75 	char str[STRSIZ];
76 	char *timep, *endp;
77 	time_t time;
78 	u_long ultmp;
79 	FILE *mtabfile;
80 
81 	if ((mtabfile = fopen(PATH_MOUNTTAB, "r")) == NULL) {
82 		if (errno == ENOENT)
83 			return (0);
84 		else {
85 			syslog(LOG_ERR, "can't open %s", PATH_MOUNTTAB);
86 			return (0);
87 		}
88 	}
89 	time = 0;
90 	mtabpp = &mtabhead;
91 	while (fgets(str, STRSIZ, mtabfile) != NULL) {
92 		cp = str;
93 		errno = 0;
94 		if (*cp == '#' || *cp == ' ' || *cp == '\n')
95 			continue;
96 		timep = strsep(&cp, " \t\n");
97 		if (timep == NULL || *timep == '\0') {
98 			badline("time", timep);
99 			continue;
100 		}
101 		hostp = strsep(&cp, " \t\n");
102 		if (hostp == NULL || *hostp == '\0') {
103 			badline("host", hostp);
104 			continue;
105 		}
106 		dirp = strsep(&cp, " \t\n");
107 		if (dirp == NULL || *dirp == '\0') {
108 			badline("dir", dirp);
109 			continue;
110 		}
111 		ultmp = strtoul(timep, &endp, 10);
112 		if (ultmp == ULONG_MAX || *endp != '\0') {
113 			badline("time", timep);
114 			continue;
115 		}
116 		time = ultmp;
117 		if ((mtabp = malloc(sizeof (struct mtablist))) == NULL) {
118 			syslog(LOG_ERR, "malloc");
119 			fclose(mtabfile);
120 			return (0);
121 		}
122 		mtabp->mtab_time = time;
123 		memmove(mtabp->mtab_host, hostp, RPCMNT_NAMELEN);
124 		mtabp->mtab_host[RPCMNT_NAMELEN - 1] = '\0';
125 		memmove(mtabp->mtab_dirp, dirp, RPCMNT_PATHLEN);
126 		mtabp->mtab_dirp[RPCMNT_PATHLEN - 1] = '\0';
127 		mtabp->mtab_next = (struct mtablist *)NULL;
128 		*mtabpp = mtabp;
129 		mtabpp = &mtabp->mtab_next;
130 	}
131 	fclose(mtabfile);
132 	return (1);
133 }
134 
135 /*
136  * Rewrite PATH_MOUNTTAB from scratch and skip bad entries.
137  * Unlink PATH_MOUNTAB if no entry is left.
138  */
139 int
140 write_mtab(int verbose) {
141 	struct mtablist *mtabp, *mp;
142 	FILE *mtabfile;
143 	int line;
144 
145 	if ((mtabfile = fopen(PATH_MOUNTTAB, "w")) == NULL) {
146 		syslog(LOG_ERR, "can't write to %s", PATH_MOUNTTAB);
147 			return (0);
148 	}
149 	line = 0;
150 	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
151 		if (mtabp->mtab_host[0] == '\0')
152 			continue;
153 		/* Skip if a later (hence more recent) entry is identical. */
154 		for (mp = mtabp->mtab_next; mp != NULL; mp = mp->mtab_next)
155 			if (strcmp(mtabp->mtab_host, mp->mtab_host) == 0 &&
156 			    strcmp(mtabp->mtab_dirp, mp->mtab_dirp) == 0)
157 				break;
158 		if (mp != NULL)
159 			continue;
160 
161 		fprintf(mtabfile, "%ld\t%s\t%s\n",
162 		    (long)mtabp->mtab_time, mtabp->mtab_host,
163 		    mtabp->mtab_dirp);
164 		if (verbose)
165 			warnx("write mounttab entry %s:%s",
166 			    mtabp->mtab_host, mtabp->mtab_dirp);
167 		line++;
168 	}
169 	fclose(mtabfile);
170 	if (line == 0) {
171 		if (unlink(PATH_MOUNTTAB) == -1) {
172 			syslog(LOG_ERR, "can't remove %s", PATH_MOUNTTAB);
173 			return (0);
174 		}
175 	}
176 	return (1);
177 }
178 
179 /*
180  * Mark the entries as clean where RPC calls have been done successfully.
181  */
182 void
183 clean_mtab(char *hostp, char *dirp, int verbose) {
184 	struct mtablist *mtabp;
185 	char *host;
186 
187 	/* Copy hostp in case it points to an entry that we are zeroing out. */
188 	host = strdup(hostp);
189 	for (mtabp = mtabhead; mtabp != NULL; mtabp = mtabp->mtab_next) {
190 		if (strcmp(mtabp->mtab_host, host) != 0)
191 			continue;
192 		if (dirp != NULL && strcmp(mtabp->mtab_dirp, dirp) != 0)
193 			continue;
194 
195 		if (verbose)
196 			warnx("delete mounttab entry%s %s:%s",
197 			    (dirp == NULL) ? " by host" : "",
198 			    mtabp->mtab_host, mtabp->mtab_dirp);
199 		bzero(mtabp->mtab_host, RPCMNT_NAMELEN);
200 	}
201 	free(host);
202 }
203 
204 /*
205  * Free struct mtablist mtab.
206  */
207 void
208 free_mtab() {
209 	struct mtablist *mtabp;
210 
211 	while ((mtabp = mtabhead) != NULL) {
212 		mtabhead = mtabhead->mtab_next;
213 		free(mtabp);
214 	}
215 }
216 
217 /*
218  * Print bad lines to syslog.
219  */
220 static void
221 badline(char *field, char *bad) {
222 	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
223 	    (bad == NULL) ? "<null>" : bad);
224 }
225