fsshare.c revision 1.3.2.1
1 /* $NetBSD: fsshare.c,v 1.3.2.1 2019/06/10 21:52:03 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd (at) FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 /* __FBSDID("$FreeBSD: head/cddl/compat/opensolaris/misc/fsshare.c 299342 2016-05-10 07:50:57Z bapt $"); */ 31 32 __RCSID("$NetBSD: fsshare.c,v 1.3.2.1 2019/06/10 21:52:03 christos Exp $"); 33 34 #include <sys/param.h> 35 36 #include <assert.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <fsshare.h> 40 #include <pathnames.h> /* _PATH_MOUNTDPID */ 41 #include <signal.h> 42 #include <stdio.h> 43 #include <string.h> 44 #include <unistd.h> 45 #include <stdlib.h> 46 47 #define FILE_HEADER "# !!! DO NOT EDIT THIS FILE MANUALLY !!!\n\n" 48 #define OPTSSIZE 1024 49 #define MAXLINESIZE (PATH_MAX + OPTSSIZE) 50 51 static void 52 restart_mountd(void) 53 { 54 int pid; 55 FILE *pfh; 56 57 pfh = fopen(_PATH_MOUNTDPID, "r"); 58 if (pfh == NULL) 59 return; 60 fscanf(pfh, "%d", &pid); 61 fclose(pfh); 62 kill((pid_t)pid, SIGHUP); 63 } 64 65 /* 66 * Read one line from a file. Skip comments, empty lines and a line with a 67 * mountpoint specified in the 'skip' argument. 68 */ 69 static char * 70 zgetline(FILE *fd, const char *skip) 71 { 72 static char line[MAXLINESIZE]; 73 size_t len, skiplen; 74 char *s, last; 75 76 if (skip != NULL) 77 skiplen = strlen(skip); 78 for (;;) { 79 s = fgets(line, sizeof(line), fd); 80 if (s == NULL) 81 return (NULL); 82 /* Skip empty lines and comments. */ 83 if (line[0] == '\n' || line[0] == '#') 84 continue; 85 len = strlen(line); 86 if (line[len - 1] == '\n') 87 line[len - 1] = '\0'; 88 last = line[skiplen]; 89 /* Skip the given mountpoint. */ 90 if (skip != NULL && strncmp(skip, line, skiplen) == 0 && 91 (last == '\t' || last == ' ' || last == '\0')) { 92 continue; 93 } 94 break; 95 } 96 return (line); 97 } 98 99 /* 100 * Function translate options to a format acceptable by exports(5), eg. 101 * 102 * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 freefall.freebsd.org 69.147.83.54 103 * 104 * Accepted input formats: 105 * 106 * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,freefall.freebsd.org 107 * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 freefall.freebsd.org 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 * 111 * Recognized keywords: 112 * 113 * ro, maproot, mapall, mask, network, alldirs, public, webnfs, index, quiet 114 * 115 */ 116 static const char *known_opts[] = { "ro", "maproot", "mapall", "mask", 117 "network", "alldirs", "public", "webnfs", "index", "quiet", NULL }; 118 static char * 119 translate_opts(const char *shareopts) 120 { 121 static char newopts[OPTSSIZE]; 122 char oldopts[OPTSSIZE]; 123 char *o, *s = NULL; 124 unsigned int i; 125 size_t len; 126 127 strlcpy(oldopts, shareopts, sizeof(oldopts)); 128 newopts[0] = '\0'; 129 s = oldopts; 130 while ((o = strsep(&s, "-, ")) != NULL) { 131 if (o[0] == '\0') 132 continue; 133 for (i = 0; known_opts[i] != NULL; i++) { 134 len = strlen(known_opts[i]); 135 if (strncmp(known_opts[i], o, len) == 0 && 136 (o[len] == '\0' || o[len] == '=')) { 137 strlcat(newopts, "-", sizeof(newopts)); 138 break; 139 } 140 } 141 strlcat(newopts, o, sizeof(newopts)); 142 strlcat(newopts, " ", sizeof(newopts)); 143 } 144 return (newopts); 145 } 146 147 static int 148 fsshare_main(const char *file, const char *mountpoint, const char *shareopts, 149 int share) 150 { 151 char tmpfile[PATH_MAX]; 152 char *line; 153 FILE *newfd, *oldfd; 154 int fd, error; 155 156 newfd = oldfd = NULL; 157 error = 0; 158 159 /* 160 * Create temporary file in the same directory, so we can atomically 161 * rename it. 162 */ 163 if (strlcpy(tmpfile, file, sizeof(tmpfile)) >= sizeof(tmpfile)) 164 return (ENAMETOOLONG); 165 if (strlcat(tmpfile, ".XXXXXXXX", sizeof(tmpfile)) >= sizeof(tmpfile)) 166 return (ENAMETOOLONG); 167 fd = mkstemp(tmpfile); 168 if (fd == -1) 169 return (errno); 170 /* 171 * File name is random, so we don't really need file lock now, but it 172 * will be needed after rename(2). 173 */ 174 error = flock(fd, LOCK_EX); 175 assert(error == 0 || (error == -1 && errno == EOPNOTSUPP)); 176 newfd = fdopen(fd, "r+"); 177 assert(newfd != NULL); 178 /* Open old exports file. */ 179 oldfd = fopen(file, "r"); 180 if (oldfd == NULL) { 181 if (share) { 182 if (errno != ENOENT) { 183 error = errno; 184 goto out; 185 } 186 } else { 187 /* If there is no exports file, ignore the error. */ 188 if (errno == ENOENT) 189 errno = 0; 190 error = errno; 191 goto out; 192 } 193 } else { 194 error = flock(fileno(oldfd), LOCK_EX); 195 assert(error == 0 || (error == -1 && errno == EOPNOTSUPP)); 196 error = 0; 197 } 198 199 /* Place big, fat warning at the begining of the file. */ 200 fprintf(newfd, "%s", FILE_HEADER); 201 while (oldfd != NULL && (line = zgetline(oldfd, mountpoint)) != NULL) 202 fprintf(newfd, "%s\n", line); 203 if (oldfd != NULL && ferror(oldfd) != 0) { 204 error = ferror(oldfd); 205 goto out; 206 } 207 if (ferror(newfd) != 0) { 208 error = ferror(newfd); 209 goto out; 210 } 211 if (share) { 212 fprintf(newfd, "%s\t%s\n", mountpoint, 213 translate_opts(shareopts)); 214 } 215 216 out: 217 if (error != 0) 218 unlink(tmpfile); 219 else { 220 if (rename(tmpfile, file) == -1) { 221 error = errno; 222 unlink(tmpfile); 223 } else { 224 /* 225 * Send SIGHUP to mountd, but unlock exports file later. 226 */ 227 restart_mountd(); 228 } 229 } 230 if (oldfd != NULL) { 231 flock(fileno(oldfd), LOCK_UN); 232 fclose(oldfd); 233 } 234 if (newfd != NULL) { 235 flock(fileno(newfd), LOCK_UN); 236 fclose(newfd); 237 } 238 return (error); 239 } 240 241 /* 242 * Add the given mountpoint to the given exports file. 243 */ 244 int 245 fsshare(const char *file, const char *mountpoint, const char *shareopts) 246 { 247 248 return (fsshare_main(file, mountpoint, shareopts, 1)); 249 } 250 251 /* 252 * Remove the given mountpoint from the given exports file. 253 */ 254 int 255 fsunshare(const char *file, const char *mountpoint) 256 { 257 258 return (fsshare_main(file, mountpoint, NULL, 0)); 259 } 260
Indexes created Fri Mar 20 00:23:26 UTC 2026