Add support for multiple lines to the sharenfs property for FreeBSD (#16338)

There has been a bugzilla PR#147881 requesting this
for a long time (14 years!). It extends the syntax of
the ZFS shanenfs property (for FreeBSD only) to allow
multiple sets of options for different hosts/nets,
separated by ';'s.

Signed-off-by:	Rick Macklem <rmacklem@FreeBSD.org>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>

diff --git a/lib/libshare/os/freebsd/nfs.c b/lib/libshare/os/freebsd/nfs.c
index d4cdb07a4947055497227673eeb850a76de7a069..b5ce221bb1cb8bfeb0b76983bdd24648ffd23bc5 100644 (file)
--- a/lib/libshare/os/freebsd/nfs.c
+++ b/lib/libshare/os/freebsd/nfs.c
@@ -44,8 +44,6 @@
 #include "nfs.h"
 
 #define        _PATH_MOUNTDPID "/var/run/mountd.pid"
-#define        OPTSSIZE        1024
-#define        MAXLINESIZE     (PATH_MAX + OPTSSIZE)
 #define        ZFS_EXPORTS_FILE        "/etc/zfs/exports"
 #define        ZFS_EXPORTS_LOCK        ZFS_EXPORTS_FILE".lock"
 
@@ -69,17 +67,30 @@
  *     index, quiet
  */
 static int
-translate_opts(const char *shareopts, FILE *out)
+translate_opts(char *oldopts, FILE *out)
 {
        static const char *const known_opts[] = { "ro", "maproot", "mapall",
            "mask", "network", "sec", "alldirs", "public", "webnfs", "index",
            "quiet" };
-       char oldopts[OPTSSIZE], newopts[OPTSSIZE];
-       char *o, *s = NULL;
+       char *newopts, *o, *s = NULL;
        unsigned int i;
-       size_t len;
-
-       strlcpy(oldopts, shareopts, sizeof (oldopts));
+       size_t len, newopts_len;
+       int ret;
+
+       /*
+        * Calculate the length needed for the worst case of a single
+        * character option:
+        * - Add one to strlen(oldopts) so that the trailing nul is counted
+        *   as a separator.
+        * - Multiply by 3/2 since the single character option plus separator
+        *   is expanded to 3 characters.
+        * - Add one for the trailing nul.  Needed for a single repetition of
+        *   the single character option and certain other cases.
+        */
+       newopts_len = (strlen(oldopts) + 1) * 3 / 2 + 1;
+       newopts = malloc(newopts_len);
+       if (newopts == NULL)
+               return (EOF);
        newopts[0] = '\0';
        s = oldopts;
        while ((o = strsep(&s, "-, ")) != NULL) {
@@ -89,14 +100,16 @@ translate_opts(const char *shareopts, FILE *out)
                        len = strlen(known_opts[i]);
                        if (strncmp(known_opts[i], o, len) == 0 &&
                            (o[len] == '\0' || o[len] == '=')) {
-                               strlcat(newopts, "-", sizeof (newopts));
+                               strlcat(newopts, "-", newopts_len);
                                break;
                        }
                }
-               strlcat(newopts, o, sizeof (newopts));
-               strlcat(newopts, " ", sizeof (newopts));
+               strlcat(newopts, o, newopts_len);
+               strlcat(newopts, " ", newopts_len);
        }
-       return (fputs(newopts, out));
+       ret = fputs(newopts, out);
+       free(newopts);
+       return (ret);
 }
 
 static int
@@ -106,20 +119,38 @@ nfs_enable_share_impl(sa_share_impl_t impl_share, FILE *tmpfile)
        if (strcmp(shareopts, "on") == 0)
                shareopts = "";
 
-       boolean_t need_free;
-       char *mp;
+       boolean_t need_free, fnd_semi;
+       char *mp, *lineopts, *exportopts, *s;
+       size_t whitelen;
        int rc  = nfs_escape_mountpoint(impl_share->sa_mountpoint, &mp,
            &need_free);
        if (rc != SA_OK)
                return (rc);
 
-       if (fputs(mp, tmpfile) == EOF ||
-           fputc('\t', tmpfile) == EOF ||
-           translate_opts(shareopts, tmpfile) == EOF ||
-           fputc('\n', tmpfile) == EOF) {
-               fprintf(stderr, "failed to write to temporary file\n");
-               rc = SA_SYSTEM_ERR;
+       lineopts = strdup(shareopts);
+       if (lineopts == NULL)
+               return (SA_SYSTEM_ERR);
+       s = lineopts;
+       fnd_semi = B_FALSE;
+       while ((exportopts = strsep(&s, ";")) != NULL) {
+               if (s != NULL)
+                       fnd_semi = B_TRUE;
+               /* Ignore only whitespace between ';' separated option sets. */
+               if (fnd_semi) {
+                       whitelen = strspn(exportopts, "\t ");
+                       if (exportopts[whitelen] == '\0')
+                               continue;
+               }
+               if (fputs(mp, tmpfile) == EOF ||
+                   fputc('\t', tmpfile) == EOF ||
+                   translate_opts(exportopts, tmpfile) == EOF ||
+                   fputc('\n', tmpfile) == EOF) {
+                       fprintf(stderr, "failed to write to temporary file\n");
+                       rc = SA_SYSTEM_ERR;
+                       break;
+               }
        }
+       free(lineopts);
 
        if (need_free)
                free(mp);

diff --git a/man/man7/zfsprops.7 b/man/man7/zfsprops.7
index 429369bd2e9e991541f89437fdeff3a8e1606207..f7026119b730cd9fc078add350d6840757124fd3 100644 (file)
--- a/man/man7/zfsprops.7
+++ b/man/man7/zfsprops.7
@@ -38,7 +38,7 @@
 .\" Copyright (c) 2019, Kjeld Schouten-Lebbing
 .\" Copyright (c) 2022 Hewlett Packard Enterprise Development LP.
 .\"
-.Dd August 8, 2023
+.Dd June 29, 2024
 .Dt ZFSPROPS 7
 .Os
 .
@@ -1727,6 +1727,18 @@ Please note that the options are comma-separated, unlike those found in
 This is done to negate the need for quoting, as well as to make parsing
 with scripts easier.
 .Pp
+For
+.Fx ,
+there may be multiple sets of options separated by semicolon(s).
+Each set of options must apply to different hosts or networks and each
+set of options will create a separate line for
+.Xr exports 5 .
+Any semicolon separated option set that consists entirely of whitespace
+will be ignored.
+This use of semicolons is only for
+.Fx
+at this time.
+.Pp
 See
 .Xr exports 5
 for the meaning of the default options.