+static int nfs_do_mount_v3v2(struct nfsmount_info *mi,
+ struct sockaddr *sap, socklen_t salen)
+{
+ struct mount_options *options = po_dup(mi->options);
+ int result = 0;
+
+ if (!options) {
+ errno = ENOMEM;
+ return result;
+ }
+ errno = 0;
+ if (!nfs_append_addr_option(sap, salen, options)) {
+ if (errno == 0)
+ errno = EINVAL;
+ goto out_fail;
+ }
+
+ if (!nfs_fix_mounthost_option(options, mi->hostname)) {
+ if (errno == 0)
+ errno = EINVAL;
+ goto out_fail;
+ }
+ if (!mi->fake && !nfs_verify_lock_option(options)) {
+ if (errno == 0)
+ errno = EINVAL;
+ goto out_fail;
+ }
+
+ /*
+ * Options we negotiate below may be stale by the time this
+ * file system is unmounted. In order to force umount.nfs
+ * to renegotiate with the server, only write the user-
+ * specified options, and not negotiated options, to /etc/mtab.
+ */
+ if (po_join(options, mi->extra_opts) == PO_FAILED) {
+ errno = ENOMEM;
+ goto out_fail;
+ }
+
+ if (verbose)
+ printf(_("%s: trying text-based options '%s'\n"),
+ progname, *mi->extra_opts);
+
+ if (!nfs_rewrite_pmap_mount_options(options))
+ goto out_fail;
+
+ result = nfs_sys_mount(mi, options);
+
+out_fail:
+ po_destroy(options);
+ return result;
+}
+
+/*
+ * Attempt a "-t nfs vers=2" or "-t nfs vers=3" mount.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_try_mount_v3v2(struct nfsmount_info *mi)
+{
+ struct addrinfo *ai;
+ int ret = 0;
+
+ for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
+ ret = nfs_do_mount_v3v2(mi, ai->ai_addr, ai->ai_addrlen);
+ if (ret != 0)
+ return ret;
+
+ switch (errno) {
+ case ECONNREFUSED:
+ case EOPNOTSUPP:
+ case EHOSTUNREACH:
+ continue;
+ default:
+ goto out;
+ }
+ }
+out:
+ return ret;
+}
+
+static int nfs_do_mount_v4(struct nfsmount_info *mi,
+ struct sockaddr *sap, socklen_t salen)
+{
+ struct mount_options *options = po_dup(mi->options);
+ int result = 0;
+
+ if (!options) {
+ errno = ENOMEM;
+ return result;
+ }
+
+ if (mi->version == 0) {
+ if (po_contains(options, "mounthost") ||
+ po_contains(options, "mountaddr") ||
+ po_contains(options, "mountvers") ||
+ po_contains(options, "mountproto")) {
+ /*
+ * Since these mountd options are set assume version 3
+ * is wanted so error out with EPROTONOSUPPORT so the
+ * protocol negation starts with v3.
+ */
+ errno = EPROTONOSUPPORT;
+ goto out_fail;
+ }
+ if (po_append(options, "vers=4") == PO_FAILED) {
+ errno = EINVAL;
+ goto out_fail;
+ }
+ }
+
+ if (!nfs_append_addr_option(sap, salen, options)) {
+ errno = EINVAL;
+ goto out_fail;
+ }
+
+ if (!nfs_append_clientaddr_option(sap, salen, options)) {
+ errno = EINVAL;
+ goto out_fail;
+ }
+
+ /*
+ * Update option string to be recorded in /etc/mtab.
+ */
+ if (po_join(options, mi->extra_opts) == PO_FAILED) {
+ errno = ENOMEM;
+ goto out_fail;
+ }
+
+ if (verbose)
+ printf(_("%s: trying text-based options '%s'\n"),
+ progname, *mi->extra_opts);
+
+ result = nfs_sys_mount(mi, options);
+
+out_fail:
+ po_destroy(options);
+ return result;
+}
+
+/*
+ * Attempt a "-t nfs -o vers=4" or "-t nfs4" mount.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_try_mount_v4(struct nfsmount_info *mi)
+{
+ struct addrinfo *ai;
+ int ret = 0;
+
+ for (ai = mi->address; ai != NULL; ai = ai->ai_next) {
+ ret = nfs_do_mount_v4(mi, ai->ai_addr, ai->ai_addrlen);
+ if (ret != 0)
+ return ret;
+
+ switch (errno) {
+ case ECONNREFUSED:
+ case EHOSTUNREACH:
+ continue;
+ default:
+ goto out;
+ }
+ }
+out:
+ return ret;
+}
+
+/*
+ * Handle NFS version and transport protocol
+ * autonegotiation.
+ *
+ * When no version or protocol is specified on the
+ * command line, mount.nfs negotiates with the server
+ * to determine appropriate settings for the new
+ * mount point.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_autonegotiate(struct nfsmount_info *mi)
+{
+ int result;
+
+ result = nfs_try_mount_v4(mi);
+ if (result)
+ return result;
+
+ switch (errno) {
+ case EPROTONOSUPPORT:
+ /* A clear indication that the server or our
+ * client does not support NFS version 4. */
+ goto fall_back;
+ case ENOENT:
+ /* Legacy Linux servers don't export an NFS
+ * version 4 pseudoroot. */
+ goto fall_back;
+ case EPERM:
+ /* Linux servers prior to 2.6.25 may return
+ * EPERM when NFS version 4 is not supported. */
+ goto fall_back;
+ default:
+ return result;
+ }
+
+fall_back:
+ return nfs_try_mount_v3v2(mi);
+}
+
+/*
+ * This is a single pass through the fg/bg loop.
+ *
+ * Returns TRUE if successful, otherwise FALSE.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_try_mount(struct nfsmount_info *mi)
+{
+ int result = 0;
+
+ switch (mi->version) {
+ case 0:
+ result = nfs_autonegotiate(mi);
+ break;
+ case 2:
+ case 3:
+ result = nfs_try_mount_v3v2(mi);
+ break;
+ case 4:
+ result = nfs_try_mount_v4(mi);
+ break;
+ default:
+ errno = EIO;
+ }
+
+ return result;
+}
+