1 /*-
2 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
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 AUTHORS 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 AUTHORS 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 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/9/cddl/compat/opensolaris/misc/fsshare.c 222313 2011-05-26 16:27:00Z will $");
29
30 #include <sys/param.h>
31
32 #include <assert.h>
33 #include <errno.h>
34 #include <fcntl.h>
35 #include <fsshare.h>
36 #include <libutil.h>
37 #include <pathnames.h> /* _PATH_MOUNTDPID */
38 #include <signal.h>
39 #include <stdio.h>
40 #include <string.h>
41 #include <unistd.h>
42
43 #define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n"
44 #define OPTSSIZE 1024
45 #define MAXLINESIZE (PATH_MAX + OPTSSIZE)
46
47 static void
restart_mountd(void)48 restart_mountd(void)
49 {
50 struct pidfh *pfh;
51 pid_t mountdpid;
52
53 pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
54 if (pfh != NULL) {
55 /* Mountd is not running. */
56 pidfile_remove(pfh);
57 return;
58 }
59 if (errno != EEXIST) {
60 /* Cannot open pidfile for some reason. */
61 return;
62 }
63 /* We have mountd(8) PID in mountdpid varible. */
64 kill(mountdpid, SIGHUP);
65 }
66
67 /*
68 * Read one line from a file. Skip comments, empty lines and a line with a
69 * mountpoint specified in the 'skip' argument.
70 */
71 static char *
getline(FILE * fd,const char * skip)72 getline(FILE *fd, const char *skip)
73 {
74 static char line[MAXLINESIZE];
75 size_t len, skiplen;
76 char *s, last;
77
78 if (skip != NULL)
79 skiplen = strlen(skip);
80 for (;;) {
81 s = fgets(line, sizeof(line), fd);
82 if (s == NULL)
83 return (NULL);
84 /* Skip empty lines and comments. */
85 if (line[0] == '\n' || line[0] == '#')
86 continue;
87 len = strlen(line);
88 if (line[len - 1] == '\n')
89 line[len - 1] = '\0';
90 last = line[skiplen];
91 /* Skip the given mountpoint. */
92 if (skip != NULL && strncmp(skip, line, skiplen) == 0 &&
93 (last == '\t' || last == ' ' || last == '\0')) {
94 continue;
95 }
96 break;
97 }
98 return (line);
99 }
100
101 /*
102 * Function translate options to a format acceptable by exports(5), eg.
103 *
104 * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org 69.147.83.54
105 *
106 * Accepted input formats:
107 *
108 * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,freefall.freebsd.org
109 * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 freefall.freebsd.org
110 * -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,freefall.freebsd.org
111 * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org
112 *
113 * Recognized keywords:
114 *
115 * ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs, index, quiet
116 *
117 */
118 static const char *known_opts[] = { "ro", "maproot", "mapall", "mask",
119 "network", "sec", "alldirs", "public", "webnfs", "index", "quiet", NULL };
120 static char *
translate_opts(const char * shareopts)121 translate_opts(const char *shareopts)
122 {
123 static char newopts[OPTSSIZE];
124 char oldopts[OPTSSIZE];
125 char *o, *s = NULL;
126 unsigned int i;
127 size_t len;
128
129 strlcpy(oldopts, shareopts, sizeof(oldopts));
130 newopts[0] = '\0';
131 s = oldopts;
132 while ((o = strsep(&s, "-, ")) != NULL) {
133 if (o[0] == '\0')
134 continue;
135 for (i = 0; known_opts[i] != NULL; i++) {
136 len = strlen(known_opts[i]);
137 if (strncmp(known_opts[i], o, len) == 0 &&
138 (o[len] == '\0' || o[len] == '=')) {
139 strlcat(newopts, "-", sizeof(newopts));
140 break;
141 }
142 }
143 strlcat(newopts, o, sizeof(newopts));
144 strlcat(newopts, " ", sizeof(newopts));
145 }
146 return (newopts);
147 }
148
149 static int
fsshare_main(const char * file,const char * mountpoint,const char * shareopts,int share)150 fsshare_main(const char *file, const char *mountpoint, const char *shareopts,
151 int share)
152 {
153 char tmpfile[PATH_MAX];
154 char *line;
155 FILE *newfd, *oldfd;
156 int fd, error;
157
158 newfd = oldfd = NULL;
159 error = 0;
160
161 /*
162 * Create temporary file in the same directory, so we can atomically
163 * rename it.
164 */
165 if (strlcpy(tmpfile, file, sizeof(tmpfile)) >= sizeof(tmpfile))
166 return (ENAMETOOLONG);
167 if (strlcat(tmpfile, ".XXXXXXXX", sizeof(tmpfile)) >= sizeof(tmpfile))
168 return (ENAMETOOLONG);
169 fd = mkstemp(tmpfile);
170 if (fd == -1)
171 return (errno);
172 /*
173 * File name is random, so we don't really need file lock now, but it
174 * will be needed after rename(2).
175 */
176 error = flock(fd, LOCK_EX);
177 assert(error == 0 || (error == -1 && errno == EOPNOTSUPP));
178 newfd = fdopen(fd, "r+");
179 assert(newfd != NULL);
180 /* Open old exports file. */
181 oldfd = fopen(file, "r");
182 if (oldfd == NULL) {
183 if (share) {
184 if (errno != ENOENT) {
185 error = errno;
186 goto out;
187 }
188 } else {
189 /* If there is no exports file, ignore the error. */
190 if (errno == ENOENT)
191 errno = 0;
192 error = errno;
193 goto out;
194 }
195 } else {
196 error = flock(fileno(oldfd), LOCK_EX);
197 assert(error == 0 || (error == -1 && errno == EOPNOTSUPP));
198 error = 0;
199 }
200
201 /* Place big, fat warning at the begining of the file. */
202 fprintf(newfd, "%s", FILE_HEADER);
203 while (oldfd != NULL && (line = getline(oldfd, mountpoint)) != NULL)
204 fprintf(newfd, "%s\n", line);
205 if (oldfd != NULL && ferror(oldfd) != 0) {
206 error = ferror(oldfd);
207 goto out;
208 }
209 if (ferror(newfd) != 0) {
210 error = ferror(newfd);
211 goto out;
212 }
213 if (share) {
214 fprintf(newfd, "%s\t%s\n", mountpoint,
215 translate_opts(shareopts));
216 }
217
218 out:
219 if (error != 0)
220 unlink(tmpfile);
221 else {
222 if (rename(tmpfile, file) == -1) {
223 error = errno;
224 unlink(tmpfile);
225 } else {
226 fflush(newfd);
227 /*
228 * Send SIGHUP to mountd, but unlock exports file later.
229 */
230 restart_mountd();
231 }
232 }
233 if (oldfd != NULL) {
234 flock(fileno(oldfd), LOCK_UN);
235 fclose(oldfd);
236 }
237 if (newfd != NULL) {
238 flock(fileno(newfd), LOCK_UN);
239 fclose(newfd);
240 }
241 return (error);
242 }
243
244 /*
245 * Add the given mountpoint to the given exports file.
246 */
247 int
fsshare(const char * file,const char * mountpoint,const char * shareopts)248 fsshare(const char *file, const char *mountpoint, const char *shareopts)
249 {
250
251 return (fsshare_main(file, mountpoint, shareopts, 1));
252 }
253
254 /*
255 * Remove the given mountpoint from the given exports file.
256 */
257 int
fsunshare(const char * file,const char * mountpoint)258 fsunshare(const char *file, const char *mountpoint)
259 {
260
261 return (fsshare_main(file, mountpoint, NULL, 0));
262 }
263