lib/libshare/os/freebsd/nfs.c

   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, 2022 by Delphix. All rights reserved.
  27  */
  28
  29 #include <sys/param.h>
  30 #include <sys/vfs.h>
  31
  32 #include <assert.h>
  33 #include <errno.h>
  34 #include <fcntl.h>
  35 #include <libutil.h>
  36 #include <signal.h>
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <libintl.h>
  41
  42 #include <libshare.h>
  43 #include "libshare_impl.h"
  44 #include "nfs.h"
  45
  46 #define _PATH_MOUNTDPID "/var/run/mountd.pid"
  47 #define ZFS_EXPORTS_FILE        "/etc/zfs/exports"
  48 #define ZFS_EXPORTS_LOCK        ZFS_EXPORTS_FILE".lock"
  49
  50 /*
  51  * This function translates options to a format acceptable by exports(5), eg.
  52  *
  53  *      -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \
  54  *      zfs.freebsd.org 69.147.83.54
  55  *
  56  * Accepted input formats:
  57  *
  58  *      ro,network=192.168.0.0,mask=255.255.255.0,maproot=0,zfs.freebsd.org
  59  *      ro network=192.168.0.0 mask=255.255.255.0 maproot=0 zfs.freebsd.org
  60  *      -ro,-network=192.168.0.0,-mask=255.255.255.0,-maproot=0,zfs.freebsd.org
  61  *      -ro -network=192.168.0.0 -mask=255.255.255.0 -maproot=0 \
  62  *      zfs.freebsd.org
  63  *
  64  * Recognized keywords:
  65  *
  66  *      ro, maproot, mapall, mask, network, sec, alldirs, public, webnfs,
  67  *      index, quiet
  68  */
  69 static int
  70 translate_opts(char *oldopts, FILE *out)
  71 {
  72         static const char *const known_opts[] = { "ro", "maproot", "mapall",
  73             "mask", "network", "sec", "alldirs", "public", "webnfs", "index",
  74             "quiet" };
  75         char *newopts, *o, *s = NULL;
  76         unsigned int i;
  77         size_t len, newopts_len;
  78         int ret;
  79
  80         /*
  81          * Calculate the length needed for the worst case of a single
  82          * character option:
  83          * - Add one to strlen(oldopts) so that the trailing nul is counted
  84          *   as a separator.
  85          * - Multiply by 3/2 since the single character option plus separator
  86          *   is expanded to 3 characters.
  87          * - Add one for the trailing nul.  Needed for a single repetition of
  88          *   the single character option and certain other cases.
  89          */
  90         newopts_len = (strlen(oldopts) + 1) * 3 / 2 + 1;
  91         newopts = malloc(newopts_len);
  92         if (newopts == NULL)
  93                 return (EOF);
  94         newopts[0] = '\0';
  95         s = oldopts;
  96         while ((o = strsep(&s, ", ")) != NULL) {
  97                 if (o[0] == '-')
  98                         o++;
  99                 if (o[0] == '\0')
 100                         continue;
 101                 for (i = 0; i < ARRAY_SIZE(known_opts); ++i) {
 102                         len = strlen(known_opts[i]);
 103                         if (strncmp(known_opts[i], o, len) == 0 &&
 104                             (o[len] == '\0' || o[len] == '=')) {
 105                                 strlcat(newopts, "-", newopts_len);
 106                                 break;
 107                         }
 108                 }
 109                 strlcat(newopts, o, newopts_len);
 110                 strlcat(newopts, " ", newopts_len);
 111         }
 112         ret = fputs(newopts, out);
 113         free(newopts);
 114         return (ret);
 115 }
 116
 117 static int
 118 nfs_enable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
 119 {
 120         const char *shareopts = impl_share->sa_shareopts;
 121         if (strcmp(shareopts, "on") == 0)
 122                 shareopts = "";
 123
 124         boolean_t need_free, fnd_semi;
 125         char *mp, *lineopts, *exportopts, *s;
 126         size_t whitelen;
 127         int rc  = nfs_escape_mountpoint(impl_share->sa_mountpoint, &mp,
 128             &need_free);
 129         if (rc != SA_OK)
 130                 return (rc);
 131
 132         lineopts = strdup(shareopts);
 133         if (lineopts == NULL)
 134                 return (SA_SYSTEM_ERR);
 135         s = lineopts;
 136         fnd_semi = B_FALSE;
 137         while ((exportopts = strsep(&s, ";")) != NULL) {
 138                 if (s != NULL)
 139                         fnd_semi = B_TRUE;
 140                 /* Ignore only whitespace between ';' separated option sets. */
 141                 if (fnd_semi) {
 142                         whitelen = strspn(exportopts, "\t ");
 143                         if (exportopts[whitelen] == '\0')
 144                                 continue;
 145                 }
 146                 if (fputs(mp, tmpfile) == EOF ||
 147                     fputc('\t', tmpfile) == EOF ||
 148                     translate_opts(exportopts, tmpfile) == EOF ||
 149                     fputc('\n', tmpfile) == EOF) {
 150                         fprintf(stderr, "failed to write to temporary file\n");
 151                         rc = SA_SYSTEM_ERR;
 152                         break;
 153                 }
 154         }
 155         free(lineopts);
 156
 157         if (need_free)
 158                 free(mp);
 159         return (rc);
 160 }
 161
 162 static int
 163 nfs_enable_share(sa_share_impl_t impl_share)
 164 {
 165         return (nfs_toggle_share(
 166             ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share,
 167             nfs_enable_share_impl));
 168 }
 169
 170 static int
 171 nfs_disable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
 172 {
 173         (void) impl_share, (void) tmpfile;
 174         return (SA_OK);
 175 }
 176
 177 static int
 178 nfs_disable_share(sa_share_impl_t impl_share)
 179 {
 180         return (nfs_toggle_share(
 181             ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE, NULL, impl_share,
 182             nfs_disable_share_impl));
 183 }
 184
 185 static boolean_t
 186 nfs_is_shared(sa_share_impl_t impl_share)
 187 {
 188         return (nfs_is_shared_impl(ZFS_EXPORTS_FILE, impl_share));
 189 }
 190
 191 static int
 192 nfs_validate_shareopts(const char *shareopts)
 193 {
 194         if (strlen(shareopts) == 0)
 195                 return (SA_SYNTAX_ERR);
 196         return (SA_OK);
 197 }
 198
 199 /*
 200  * Commit the shares by restarting mountd.
 201  */
 202 static int
 203 nfs_commit_shares(void)
 204 {
 205         struct pidfh *pfh;
 206         pid_t mountdpid;
 207
 208 start:
 209         pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
 210         if (pfh != NULL) {
 211                 /* mountd(8) is not running. */
 212                 pidfile_remove(pfh);
 213                 return (SA_OK);
 214         }
 215         if (errno != EEXIST) {
 216                 /* Cannot open pidfile for some reason. */
 217                 return (SA_SYSTEM_ERR);
 218         }
 219         if (mountdpid == -1) {
 220                 /* mountd(8) exists, but didn't write the PID yet */
 221                 usleep(500);
 222                 goto start;
 223         }
 224         /* We have mountd(8) PID in mountdpid variable. */
 225         kill(mountdpid, SIGHUP);
 226         return (SA_OK);
 227 }
 228
 229 static void
 230 nfs_truncate_shares(void)
 231 {
 232         nfs_reset_shares(ZFS_EXPORTS_LOCK, ZFS_EXPORTS_FILE);
 233 }
 234
 235 const sa_fstype_t libshare_nfs_type = {
 236         .enable_share = nfs_enable_share,
 237         .disable_share = nfs_disable_share,
 238         .is_shared = nfs_is_shared,
 239
 240         .validate_shareopts = nfs_validate_shareopts,
 241         .commit_shares = nfs_commit_shares,
 242         .truncate_shares = nfs_truncate_shares,
 243 };