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 * Copyright (c) 2020 by Delphix. All rights reserved. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/vfs.h> 34 35 #include <assert.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <libutil.h> 39 #include <signal.h> 40 #include <stdio.h> 41 #include <string.h> 42 #include <unistd.h> 43 #include <libintl.h> 44 45 #include <libshare.h> 46 #include "libshare_impl.h" 47 #include "nfs.h" 48 49 #define _PATH_MOUNTDPID "/var/run/mountd.pid" 50 #define OPTSSIZE 1024 51 #define MAXLINESIZE (PATH_MAX + OPTSSIZE) 52 #define ZFS_EXPORTS_FILE "/etc/zfs/exports" 53 #define ZFS_EXPORTS_LOCK ZFS_EXPORTS_FILE".lock" 54 55 static sa_fstype_t *nfs_fstype; 56 57 /* 58 * Read one line from a file. Skip comments, empty lines and a line with a 59 * mountpoint specified in the 'skip' argument. 60 * 61 * NOTE: This function returns a static buffer and thus is not thread-safe. 62 */ 63 static char * 64 zgetline(FILE *fd, const char *skip) 65 { 66 static char line[MAXLINESIZE]; 67 size_t len, skiplen = 0; 68 char *s, last; 69 70 if (skip != NULL) 71 skiplen = strlen(skip); 72 for (;;) { 73 s = fgets(line, sizeof (line), fd); 74 if (s == NULL) 75 return (NULL); 76 /* Skip empty lines and comments. */ 77 if (line[0] == '\n' || line[0] == '#') 78 continue; 79 len = strlen(line); 80 if (line[len - 1] == '\n') 81 line[len - 1] = '\0'; 82 last = line[skiplen]; 83 /* Skip the given mountpoint. */ 84 if (skip != NULL && strncmp(skip, line, skiplen) == 0 && 85 (last == '\t' || last == ' ' || last == '\0')) { 86 continue; 87 } 88 break; 89 } 90 return (line); 91 } 92 93 /* 94 * This function translate options to a format acceptable by exports(5), eg. 95 * 96 * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \ 97 * zfs.freebsd.org 69.147.83.54 98 * 99 * Accepted input formats: 100 * 101 * ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,zfs.freebsd.org 102 * ro network=192.168.0.0 mask=255.255.255.0 maproot=0 zfs.freebsd.org 103 * -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,zfs.freebsd.org 104 * -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \ 105 * zfs.freebsd.org 106 * 107 * Recognized keywords: 108 * 109 * ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs, 110 * index, quiet 111 * 112 * NOTE: This function returns a static buffer and thus is not thread-safe. 113 */ 114 static char * 115 translate_opts(const char *shareopts) 116 { 117 static const char *known_opts[] = { "ro", "maproot", "mapall", "mask", 118 "network", "sec", "alldirs", "public", "webnfs", "index", "quiet", 119 NULL }; 120 static char newopts[OPTSSIZE]; 121 char oldopts[OPTSSIZE]; 122 char *o, *s = NULL; 123 unsigned int i; 124 size_t len; 125 126 strlcpy(oldopts, shareopts, sizeof (oldopts)); 127 newopts[0] = '\0'; 128 s = oldopts; 129 while ((o = strsep(&s, "-, ")) != NULL) { 130 if (o[0] == '\0') 131 continue; 132 for (i = 0; known_opts[i] != NULL; i++) { 133 len = strlen(known_opts[i]); 134 if (strncmp(known_opts[i], o, len) == 0 && 135 (o[len] == '\0' || o[len] == '=')) { 136 strlcat(newopts, "-", sizeof (newopts)); 137 break; 138 } 139 } 140 strlcat(newopts, o, sizeof (newopts)); 141 strlcat(newopts, " ", sizeof (newopts)); 142 } 143 return (newopts); 144 } 145 146 /* 147 * This function copies all entries from the exports file to "filename", 148 * omitting any entries for the specified mountpoint. 149 */ 150 int 151 nfs_copy_entries(char *filename, const char *mountpoint) 152 { 153 int error = SA_OK; 154 char *line; 155 156 FILE *oldfp = fopen(ZFS_EXPORTS_FILE, "re"); 157 FILE *newfp = fopen(filename, "w+e"); 158 if (newfp == NULL) { 159 fprintf(stderr, "failed to open %s file: %s", filename, 160 strerror(errno)); 161 fclose(oldfp); 162 return (SA_SYSTEM_ERR); 163 } 164 fputs(FILE_HEADER, newfp); 165 166 /* 167 * The ZFS_EXPORTS_FILE may not exist yet. If that's the 168 * case then just write out the new file. 169 */ 170 if (oldfp != NULL) { 171 while ((line = zgetline(oldfp, mountpoint)) != NULL) 172 fprintf(newfp, "%s\n", line); 173 if (ferror(oldfp) != 0) { 174 error = ferror(oldfp); 175 } 176 if (fclose(oldfp) != 0) { 177 fprintf(stderr, "Unable to close file %s: %s\n", 178 filename, strerror(errno)); 179 error = error != 0 ? error : SA_SYSTEM_ERR; 180 } 181 } 182 183 if (error == 0 && ferror(newfp) != 0) { 184 error = ferror(newfp); 185 } 186 187 if (fclose(newfp) != 0) { 188 fprintf(stderr, "Unable to close file %s: %s\n", 189 filename, strerror(errno)); 190 error = error != 0 ? error : SA_SYSTEM_ERR; 191 } 192 return (error); 193 } 194 195 static int 196 nfs_enable_share_impl(sa_share_impl_t impl_share, char *filename) 197 { 198 FILE *fp = fopen(filename, "a+e"); 199 if (fp == NULL) { 200 fprintf(stderr, "failed to open %s file: %s", filename, 201 strerror(errno)); 202 return (SA_SYSTEM_ERR); 203 } 204 205 char *shareopts = FSINFO(impl_share, nfs_fstype)->shareopts; 206 if (strcmp(shareopts, "on") == 0) 207 shareopts = ""; 208 209 if (fprintf(fp, "%s\t%s\n", impl_share->sa_mountpoint, 210 translate_opts(shareopts)) < 0) { 211 fprintf(stderr, "failed to write to %s\n", filename); 212 fclose(fp); 213 return (SA_SYSTEM_ERR); 214 } 215 216 if (fclose(fp) != 0) { 217 fprintf(stderr, "Unable to close file %s: %s\n", 218 filename, strerror(errno)); 219 return (SA_SYSTEM_ERR); 220 } 221 222 return (SA_OK); 223 } 224 225 static int 226 nfs_enable_share(sa_share_impl_t impl_share) 227 { 228 return (nfs_toggle_share( 229 ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share, 230 nfs_enable_share_impl)); 231 } 232 233 static int 234 nfs_disable_share_impl(sa_share_impl_t impl_share, char *filename) 235 { 236 return (SA_OK); 237 } 238 239 static int 240 nfs_disable_share(sa_share_impl_t impl_share) 241 { 242 return (nfs_toggle_share( 243 ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share, 244 nfs_disable_share_impl)); 245 } 246 247 static boolean_t 248 nfs_is_shared(sa_share_impl_t impl_share) 249 { 250 char *s, last, line[MAXLINESIZE]; 251 size_t len; 252 char *mntpoint = impl_share->sa_mountpoint; 253 size_t mntlen = strlen(mntpoint); 254 255 FILE *fp = fopen(ZFS_EXPORTS_FILE, "re"); 256 if (fp == NULL) 257 return (B_FALSE); 258 259 for (;;) { 260 s = fgets(line, sizeof (line), fp); 261 if (s == NULL) 262 return (B_FALSE); 263 /* Skip empty lines and comments. */ 264 if (line[0] == '\n' || line[0] == '#') 265 continue; 266 len = strlen(line); 267 if (line[len - 1] == '\n') 268 line[len - 1] = '\0'; 269 last = line[mntlen]; 270 /* Skip the given mountpoint. */ 271 if (strncmp(mntpoint, line, mntlen) == 0 && 272 (last == '\t' || last == ' ' || last == '\0')) { 273 fclose(fp); 274 return (B_TRUE); 275 } 276 } 277 fclose(fp); 278 return (B_FALSE); 279 } 280 281 static int 282 nfs_validate_shareopts(const char *shareopts) 283 { 284 return (SA_OK); 285 } 286 287 static int 288 nfs_update_shareopts(sa_share_impl_t impl_share, const char *shareopts) 289 { 290 FSINFO(impl_share, nfs_fstype)->shareopts = (char *)shareopts; 291 return (SA_OK); 292 } 293 294 static void 295 nfs_clear_shareopts(sa_share_impl_t impl_share) 296 { 297 FSINFO(impl_share, nfs_fstype)->shareopts = NULL; 298 } 299 300 /* 301 * Commit the shares by restarting mountd. 302 */ 303 static int 304 nfs_commit_shares(void) 305 { 306 struct pidfh *pfh; 307 pid_t mountdpid; 308 309 pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid); 310 if (pfh != NULL) { 311 /* Mountd is not running. */ 312 pidfile_remove(pfh); 313 return (SA_OK); 314 } 315 if (errno != EEXIST) { 316 /* Cannot open pidfile for some reason. */ 317 return (SA_SYSTEM_ERR); 318 } 319 /* We have mountd(8) PID in mountdpid variable. */ 320 kill(mountdpid, SIGHUP); 321 return (SA_OK); 322 } 323 324 static const sa_share_ops_t nfs_shareops = { 325 .enable_share = nfs_enable_share, 326 .disable_share = nfs_disable_share, 327 .is_shared = nfs_is_shared, 328 329 .validate_shareopts = nfs_validate_shareopts, 330 .update_shareopts = nfs_update_shareopts, 331 .clear_shareopts = nfs_clear_shareopts, 332 .commit_shares = nfs_commit_shares, 333 }; 334 335 /* 336 * Initializes the NFS functionality of libshare. 337 */ 338 void 339 libshare_nfs_init(void) 340 { 341 nfs_fstype = register_fstype("nfs", &nfs_shareops); 342 } 343