1*cc17ee2eSpgoyette /* $NetBSD: fsshare.c,v 1.4 2019/01/27 02:08:34 pgoyette Exp $ */
2fc8ec0b8Shaad
3fc8ec0b8Shaad /*-
4fc8ec0b8Shaad * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5fc8ec0b8Shaad * All rights reserved.
6fc8ec0b8Shaad *
7fc8ec0b8Shaad * Redistribution and use in source and binary forms, with or without
8fc8ec0b8Shaad * modification, are permitted provided that the following conditions
9fc8ec0b8Shaad * are met:
10fc8ec0b8Shaad * 1. Redistributions of source code must retain the above copyright
11fc8ec0b8Shaad * notice, this list of conditions and the following disclaimer.
12fc8ec0b8Shaad * 2. Redistributions in binary form must reproduce the above copyright
13fc8ec0b8Shaad * notice, this list of conditions and the following disclaimer in the
14fc8ec0b8Shaad * documentation and/or other materials provided with the distribution.
15fc8ec0b8Shaad *
16fc8ec0b8Shaad * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17fc8ec0b8Shaad * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18fc8ec0b8Shaad * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19fc8ec0b8Shaad * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20fc8ec0b8Shaad * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21fc8ec0b8Shaad * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22fc8ec0b8Shaad * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23fc8ec0b8Shaad * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24fc8ec0b8Shaad * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25fc8ec0b8Shaad * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26fc8ec0b8Shaad * SUCH DAMAGE.
27fc8ec0b8Shaad */
28fc8ec0b8Shaad
29fc8ec0b8Shaad #include <sys/cdefs.h>
30eada09acSchs /* __FBSDID("$FreeBSD: head/cddl/compat/opensolaris/misc/fsshare.c 299342 2016-05-10 07:50:57Z bapt $"); */
31eada09acSchs
32*cc17ee2eSpgoyette __RCSID("$NetBSD: fsshare.c,v 1.4 2019/01/27 02:08:34 pgoyette Exp $");
33fc8ec0b8Shaad
34fc8ec0b8Shaad #include <sys/param.h>
35eada09acSchs
36fc8ec0b8Shaad #include <assert.h>
37eada09acSchs #include <errno.h>
38eada09acSchs #include <fcntl.h>
39fc8ec0b8Shaad #include <fsshare.h>
40eada09acSchs #include <pathnames.h> /* _PATH_MOUNTDPID */
41eada09acSchs #include <signal.h>
42eada09acSchs #include <stdio.h>
43eada09acSchs #include <string.h>
44eada09acSchs #include <unistd.h>
45eada09acSchs #include <stdlib.h>
46fc8ec0b8Shaad
47fc8ec0b8Shaad #define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n"
48fc8ec0b8Shaad #define OPTSSIZE 1024
49fc8ec0b8Shaad #define MAXLINESIZE (PATH_MAX + OPTSSIZE)
50fc8ec0b8Shaad
51fc8ec0b8Shaad static void
restart_mountd(void)52fc8ec0b8Shaad restart_mountd(void)
53fc8ec0b8Shaad {
54fc8ec0b8Shaad int pid;
55fc8ec0b8Shaad FILE *pfh;
56fc8ec0b8Shaad
57fc8ec0b8Shaad pfh = fopen(_PATH_MOUNTDPID, "r");
58fc8ec0b8Shaad if (pfh == NULL)
59fc8ec0b8Shaad return;
60fc8ec0b8Shaad fscanf(pfh, "%d", &pid);
61fc8ec0b8Shaad fclose(pfh);
62fc8ec0b8Shaad kill((pid_t)pid, SIGHUP);
63fc8ec0b8Shaad }
64fc8ec0b8Shaad
65fc8ec0b8Shaad /*
66fc8ec0b8Shaad * Read one line from a file. Skip comments, empty lines and a line with a
67fc8ec0b8Shaad * mountpoint specified in the 'skip' argument.
68fc8ec0b8Shaad */
69fc8ec0b8Shaad static char *
zgetline(FILE * fd,const char * skip)7049466616Shaad zgetline(FILE *fd, const char *skip)
71fc8ec0b8Shaad {
72fc8ec0b8Shaad static char line[MAXLINESIZE];
73fc8ec0b8Shaad size_t len, skiplen;
74fc8ec0b8Shaad char *s, last;
75fc8ec0b8Shaad
76fc8ec0b8Shaad if (skip != NULL)
77fc8ec0b8Shaad skiplen = strlen(skip);
78fc8ec0b8Shaad for (;;) {
79fc8ec0b8Shaad s = fgets(line, sizeof(line), fd);
80fc8ec0b8Shaad if (s == NULL)
81fc8ec0b8Shaad return (NULL);
82fc8ec0b8Shaad /* Skip empty lines and comments. */
83fc8ec0b8Shaad if (line[0] == '\n' || line[0] == '#')
84fc8ec0b8Shaad continue;
85fc8ec0b8Shaad len = strlen(line);
86fc8ec0b8Shaad if (line[len - 1] == '\n')
87fc8ec0b8Shaad line[len - 1] = '\0';
88fc8ec0b8Shaad last = line[skiplen];
89fc8ec0b8Shaad /* Skip the given mountpoint. */
90fc8ec0b8Shaad if (skip != NULL && strncmp(skip, line, skiplen) == 0 &&
91fc8ec0b8Shaad (last == '\t' || last == ' ' || last == '\0')) {
92fc8ec0b8Shaad continue;
93fc8ec0b8Shaad }
94fc8ec0b8Shaad break;
95fc8ec0b8Shaad }
96fc8ec0b8Shaad return (line);
97fc8ec0b8Shaad }
98fc8ec0b8Shaad
99fc8ec0b8Shaad /*
100fc8ec0b8Shaad * Function translate options to a format acceptable by exports(5), eg.
101fc8ec0b8Shaad *
102fc8ec0b8Shaad * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org 69.147.83.54
103fc8ec0b8Shaad *
104fc8ec0b8Shaad * Accepted input formats:
105fc8ec0b8Shaad *
106fc8ec0b8Shaad * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,freefall.freebsd.org
107fc8ec0b8Shaad * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 freefall.freebsd.org
108fc8ec0b8Shaad * -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,freefall.freebsd.org
109fc8ec0b8Shaad * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org
110fc8ec0b8Shaad *
111fc8ec0b8Shaad * Recognized keywords:
112fc8ec0b8Shaad *
113fc8ec0b8Shaad * ro, maproot, mapall, mask, network, alldirs, public, webnfs, index, quiet
114fc8ec0b8Shaad *
115fc8ec0b8Shaad */
116fc8ec0b8Shaad static const char *known_opts[] = { "ro", "maproot", "mapall", "mask",
117fc8ec0b8Shaad "network", "alldirs", "public", "webnfs", "index", "quiet", NULL };
118fc8ec0b8Shaad static char *
translate_opts(const char * shareopts)119fc8ec0b8Shaad translate_opts(const char *shareopts)
120fc8ec0b8Shaad {
121fc8ec0b8Shaad static char newopts[OPTSSIZE];
122fc8ec0b8Shaad char oldopts[OPTSSIZE];
123fc8ec0b8Shaad char *o, *s = NULL;
124fc8ec0b8Shaad unsigned int i;
125fc8ec0b8Shaad size_t len;
126fc8ec0b8Shaad
127fc8ec0b8Shaad strlcpy(oldopts, shareopts, sizeof(oldopts));
128fc8ec0b8Shaad newopts[0] = '\0';
129fc8ec0b8Shaad s = oldopts;
130fc8ec0b8Shaad while ((o = strsep(&s, "-, ")) != NULL) {
131fc8ec0b8Shaad if (o[0] == '\0')
132fc8ec0b8Shaad continue;
133fc8ec0b8Shaad for (i = 0; known_opts[i] != NULL; i++) {
134fc8ec0b8Shaad len = strlen(known_opts[i]);
135fc8ec0b8Shaad if (strncmp(known_opts[i], o, len) == 0 &&
136fc8ec0b8Shaad (o[len] == '\0' || o[len] == '=')) {
137fc8ec0b8Shaad strlcat(newopts, "-", sizeof(newopts));
138fc8ec0b8Shaad break;
139fc8ec0b8Shaad }
140fc8ec0b8Shaad }
141fc8ec0b8Shaad strlcat(newopts, o, sizeof(newopts));
142fc8ec0b8Shaad strlcat(newopts, " ", sizeof(newopts));
143fc8ec0b8Shaad }
144fc8ec0b8Shaad return (newopts);
145fc8ec0b8Shaad }
146fc8ec0b8Shaad
147fc8ec0b8Shaad static int
fsshare_main(const char * file,const char * mountpoint,const char * shareopts,int share)148fc8ec0b8Shaad fsshare_main(const char *file, const char *mountpoint, const char *shareopts,
149fc8ec0b8Shaad int share)
150fc8ec0b8Shaad {
151fc8ec0b8Shaad char tmpfile[PATH_MAX];
152fc8ec0b8Shaad char *line;
153fc8ec0b8Shaad FILE *newfd, *oldfd;
154fc8ec0b8Shaad int fd, error;
155fc8ec0b8Shaad
156fc8ec0b8Shaad newfd = oldfd = NULL;
157fc8ec0b8Shaad error = 0;
158fc8ec0b8Shaad
159fc8ec0b8Shaad /*
160fc8ec0b8Shaad * Create temporary file in the same directory, so we can atomically
161fc8ec0b8Shaad * rename it.
162fc8ec0b8Shaad */
163fc8ec0b8Shaad if (strlcpy(tmpfile, file, sizeof(tmpfile)) >= sizeof(tmpfile))
164fc8ec0b8Shaad return (ENAMETOOLONG);
165fc8ec0b8Shaad if (strlcat(tmpfile, ".XXXXXXXX", sizeof(tmpfile)) >= sizeof(tmpfile))
166fc8ec0b8Shaad return (ENAMETOOLONG);
167fc8ec0b8Shaad fd = mkstemp(tmpfile);
168fc8ec0b8Shaad if (fd == -1)
169fc8ec0b8Shaad return (errno);
170fc8ec0b8Shaad /*
171fc8ec0b8Shaad * File name is random, so we don't really need file lock now, but it
172fc8ec0b8Shaad * will be needed after rename(2).
173fc8ec0b8Shaad */
174fc8ec0b8Shaad error = flock(fd, LOCK_EX);
175fc8ec0b8Shaad assert(error == 0 || (error == -1 && errno == EOPNOTSUPP));
176fc8ec0b8Shaad newfd = fdopen(fd, "r+");
177fc8ec0b8Shaad assert(newfd != NULL);
178fc8ec0b8Shaad /* Open old exports file. */
179fc8ec0b8Shaad oldfd = fopen(file, "r");
180fc8ec0b8Shaad if (oldfd == NULL) {
181fc8ec0b8Shaad if (share) {
182fc8ec0b8Shaad if (errno != ENOENT) {
183fc8ec0b8Shaad error = errno;
184fc8ec0b8Shaad goto out;
185fc8ec0b8Shaad }
186fc8ec0b8Shaad } else {
187fc8ec0b8Shaad /* If there is no exports file, ignore the error. */
188fc8ec0b8Shaad if (errno == ENOENT)
189fc8ec0b8Shaad errno = 0;
190fc8ec0b8Shaad error = errno;
191fc8ec0b8Shaad goto out;
192fc8ec0b8Shaad }
193fc8ec0b8Shaad } else {
194fc8ec0b8Shaad error = flock(fileno(oldfd), LOCK_EX);
195fc8ec0b8Shaad assert(error == 0 || (error == -1 && errno == EOPNOTSUPP));
196fc8ec0b8Shaad error = 0;
197fc8ec0b8Shaad }
198fc8ec0b8Shaad
199fc8ec0b8Shaad /* Place big, fat warning at the begining of the file. */
200fc8ec0b8Shaad fprintf(newfd, "%s", FILE_HEADER);
20149466616Shaad while (oldfd != NULL && (line = zgetline(oldfd, mountpoint)) != NULL)
202fc8ec0b8Shaad fprintf(newfd, "%s\n", line);
203fc8ec0b8Shaad if (oldfd != NULL && ferror(oldfd) != 0) {
204fc8ec0b8Shaad error = ferror(oldfd);
205fc8ec0b8Shaad goto out;
206fc8ec0b8Shaad }
207fc8ec0b8Shaad if (ferror(newfd) != 0) {
208fc8ec0b8Shaad error = ferror(newfd);
209fc8ec0b8Shaad goto out;
210fc8ec0b8Shaad }
211fc8ec0b8Shaad if (share) {
212fc8ec0b8Shaad fprintf(newfd, "%s\t%s\n", mountpoint,
213fc8ec0b8Shaad translate_opts(shareopts));
214fc8ec0b8Shaad }
215fc8ec0b8Shaad
216fc8ec0b8Shaad out:
217fc8ec0b8Shaad if (error != 0)
218fc8ec0b8Shaad unlink(tmpfile);
219fc8ec0b8Shaad else {
220fc8ec0b8Shaad if (rename(tmpfile, file) == -1) {
221fc8ec0b8Shaad error = errno;
222fc8ec0b8Shaad unlink(tmpfile);
223fc8ec0b8Shaad } else {
224fc8ec0b8Shaad /*
225fc8ec0b8Shaad * Send SIGHUP to mountd, but unlock exports file later.
226fc8ec0b8Shaad */
227fc8ec0b8Shaad restart_mountd();
228fc8ec0b8Shaad }
229fc8ec0b8Shaad }
230fc8ec0b8Shaad if (oldfd != NULL) {
231fc8ec0b8Shaad flock(fileno(oldfd), LOCK_UN);
232fc8ec0b8Shaad fclose(oldfd);
233fc8ec0b8Shaad }
234fc8ec0b8Shaad if (newfd != NULL) {
235fc8ec0b8Shaad flock(fileno(newfd), LOCK_UN);
236fc8ec0b8Shaad fclose(newfd);
237fc8ec0b8Shaad }
238fc8ec0b8Shaad return (error);
239fc8ec0b8Shaad }
240fc8ec0b8Shaad
241fc8ec0b8Shaad /*
242fc8ec0b8Shaad * Add the given mountpoint to the given exports file.
243fc8ec0b8Shaad */
244fc8ec0b8Shaad int
fsshare(const char * file,const char * mountpoint,const char * shareopts)245fc8ec0b8Shaad fsshare(const char *file, const char *mountpoint, const char *shareopts)
246fc8ec0b8Shaad {
247fc8ec0b8Shaad
248fc8ec0b8Shaad return (fsshare_main(file, mountpoint, shareopts, 1));
249fc8ec0b8Shaad }
250fc8ec0b8Shaad
251fc8ec0b8Shaad /*
252fc8ec0b8Shaad * Remove the given mountpoint from the given exports file.
253fc8ec0b8Shaad */
254fc8ec0b8Shaad int
fsunshare(const char * file,const char * mountpoint)255fc8ec0b8Shaad fsunshare(const char *file, const char *mountpoint)
256fc8ec0b8Shaad {
257fc8ec0b8Shaad
258fc8ec0b8Shaad return (fsshare_main(file, mountpoint, NULL, 0));
259fc8ec0b8Shaad }
260