mounttab.c revision 194880 
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: head/usr.sbin/rpc.umntall/mounttab.c 194880 2009-06-24 18:42:21Z dfr $");
30
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
46struct mtablist *mtabhead;
47
48static 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 */
54int
55add_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 */
71int
72read_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, MNTNAMLEN);
124		mtabp->mtab_host[MNTNAMLEN - 1] = '\0';
125		memmove(mtabp->mtab_dirp, dirp, MNTPATHLEN);
126		mtabp->mtab_dirp[MNTPATHLEN - 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 */
139int
140write_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 */
182void
183clean_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, MNTNAMLEN);
200	}
201	free(host);
202}
203
204/*
205 * Free struct mtablist mtab.
206 */
207void
208free_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 */
220static void
221badline(char *field, char *bad) {
222	syslog(LOG_ERR, "bad mounttab %s field '%s'", field,
223	    (bad == NULL) ? "<null>" : bad);
224}
225