X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmount%2Fstropts.c;h=967fd69531f7a338b13fe7b7775ea3d991bf2af2;hp=cc13325750aa1eb22e542c6c7911a8333e770838;hb=52dff26c60c07cf1b4fbf8fbd3a1eab7ba90405f;hpb=60fd6cd0ada4f501d6d6bcbc3e14950d453c428d

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index cc13325..967fd69 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -21,6 +21,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <ctype.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -40,6 +44,7 @@
 #include "stropts.h"
 #include "error.h"
 #include "network.h"
+#include "parse_opt.h"
 
 #ifdef HAVE_RPCSVC_NFS_PROT_H
 #include <rpcsvc/nfs_prot.h>
@@ -52,35 +57,90 @@
 #define NFS_PORT 2049
 #endif
 
+#ifndef NFS_MAXHOSTNAME
+#define NFS_MAXHOSTNAME		(255)
+#endif
+
+#ifndef NFS_MAXPATHNAME
+#define NFS_MAXPATHNAME		(1024)
+#endif
+
+#ifndef NFS_DEF_FG_TIMEOUT_MINUTES
+#define NFS_DEF_FG_TIMEOUT_MINUTES	(2u)
+#endif
+
+#ifndef NFS_DEF_BG_TIMEOUT_MINUTES
+#define NFS_DEF_BG_TIMEOUT_MINUTES	(10000u)
+#endif
+
 extern int nfs_mount_data_version;
 extern char *progname;
 extern int verbose;
 
-static int retry_opt = 10000;		/* 10,000 minutes ~= 1 week */
-static int bg_opt = 0;
-static int addr_opt = 0;
-static int ca_opt = 0;
+struct nfsmount_info {
+	const char		*spec,		/* server:/path */
+				*node,		/* mounted-on dir */
+				*type;		/* "nfs" or "nfs4" */
+	char			*hostname;	/* server's hostname */
 
-static int parse_devname(char *hostdir, char **hostname, char **dirname)
+	struct mount_options	*options;	/* parsed mount options */
+	char			**extra_opts;	/* string for /etc/mtab */
+
+	int			flags,		/* MS_ flags */
+				fake,		/* actually do the mount? */
+				child;		/* forked bg child? */
+};
+
+static int nfs_parse_devname(struct nfsmount_info *mi)
 {
-	char *s;
+	int ret = 0;
+	char *dev, *pathname, *s;
+
+	dev = xstrdup(mi->spec);
 
-	if (!(s = strchr(hostdir, ':'))) {
-		nfs_error(_("%s: directory to mount not in host:dir format"),
+	if (!(pathname = strchr(dev, ':'))) {
+		nfs_error(_("%s: remote share not in 'host:dir' format"),
 				progname);
-		return -1;
+		goto out;
 	}
-	*hostname = hostdir;
-	*dirname = s + 1;
-	*s = '\0';
-	/* Ignore all but first hostname in replicated mounts
-	   until they can be fully supported. (mack@sgi.com) */
-	if ((s = strchr(hostdir, ','))) {
+	*pathname = '\0';
+	pathname++;
+
+	/*
+	 * We don't need a copy of the pathname, but let's
+	 * sanity check it anyway.
+	 */
+	if (strlen(pathname) > NFS_MAXPATHNAME) {
+		nfs_error(_("%s: export pathname is too long"),
+				progname);
+		goto out;
+	}
+
+	/*
+	 * Ignore all but first hostname in replicated mounts
+	 * until they can be fully supported. (mack@sgi.com)
+	 */
+	if ((s = strchr(dev, ','))) {
 		*s = '\0';
 		nfs_error(_("%s: warning: multiple hostnames not supported"),
 				progname);
+		nfs_error(_("%s: ignoring hostnames that follow the first one"),
+				progname);
 	}
-	return 0;
+	mi->hostname = xstrdup(dev);
+	if (strlen(mi->hostname) > NFS_MAXHOSTNAME) {
+		nfs_error(_("%s: server hostname is too long"),
+				progname);
+		free(mi->hostname);
+		mi->hostname = NULL;
+		goto out;
+	}
+
+	ret = 1;
+
+out:
+	free(dev);
+	return ret;
 }
 
 static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
@@ -104,235 +164,616 @@ static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
 }
 
 /*
- * XXX: This should really use the technique neil recently added
- * to get the address off the local end of a socket connected to
- * the server -- to get the right address to use on multi-homed
- * clients
+ * Obtain a retry timeout value based on the value of the "retry=" option.
+ *
+ * Returns a time_t timeout timestamp, in seconds.
  */
-static int get_my_ipv4addr(char *ip_addr, int len)
+static time_t nfs_parse_retry_option(struct mount_options *options,
+				     unsigned int timeout_minutes)
 {
-	char myname[1024];
-	struct sockaddr_in myaddr;
+	char *retry_option, *endptr;
+
+	retry_option = po_get(options, "retry");
+	if (retry_option) {
+		long tmp;
+
+		errno = 0;
+		tmp = strtol(retry_option, &endptr, 10);
+		if (errno == 0 && endptr != retry_option && tmp >= 0)
+			timeout_minutes = tmp;
+		else if (verbose)
+			nfs_error(_("%s: invalid retry timeout was specified; "
+					"using default timeout"), progname);
+	}
 
-	if (gethostname(myname, sizeof(myname))) {
-		nfs_error(_("%s: can't determine client address\n"),
-				progname);
+	return time(NULL) + (time_t)(timeout_minutes * 60);
+}
+
+/*
+ * Append the 'addr=' option to the options string to pass a resolved
+ * server address to the kernel.  After a successful mount, this address
+ * is also added to /etc/mtab for use when unmounting.
+ *
+ * If 'addr=' is already present, we strip it out.  This prevents users
+ * from setting a bogus 'addr=' option themselves, and also allows bg
+ * retries to recompute the server's address, in case it has changed.
+ *
+ * Returns 1 if 'addr=' option appended successfully;
+ * otherwise zero.
+ */
+static int append_addr_option(struct sockaddr_in *saddr,
+			   struct mount_options *options)
+{
+	char new_option[24];
+
+	po_remove_all(options, "addr");
+
+	snprintf(new_option, sizeof(new_option) - 1,
+			"addr=%s", inet_ntoa(saddr->sin_addr));
+
+	if (po_append(options, new_option) == PO_SUCCEEDED)
+		return 1;
+	return 0;
+}
+
+/*
+ * Called to discover our address and append an appropriate 'clientaddr='
+ * option to the options string.
+ *
+ * Returns 1 if 'clientaddr=' option created successfully or if
+ * 'clientaddr=' option is already present; otherwise zero.
+ */
+static int append_clientaddr_option(struct sockaddr_in *saddr,
+				    struct mount_options *options)
+{
+	struct sockaddr_in my_addr;
+	char new_option[32];
+
+	if (po_contains(options, "clientaddr") == PO_SUCCEEDED)
+		return 1;
+
+	if (!get_client_address(saddr, &my_addr))
 		return 0;
-	}
-	if (!fill_ipv4_sockaddr(myname, &myaddr))
+
+	snprintf(new_option, sizeof(new_option) - 1,
+			"clientaddr=%s", inet_ntoa(my_addr.sin_addr));
+
+	if (po_append(options, new_option) == PO_SUCCEEDED)
+		return 1;
+	return 0;
+}
+
+/*
+ * Resolve the 'mounthost=' hostname and append a new option using
+ * the resulting IPv4 address.
+ */
+static int fix_mounthost_option(struct mount_options *options)
+{
+	struct sockaddr_in maddr;
+	char *mounthost, new_option[32];
+
+	mounthost = po_get(options, "mounthost");
+	if (!mounthost)
+		return 1;
+
+	if (!fill_ipv4_sockaddr(mounthost, &maddr))
 		return 0;
 
-	snprintf(ip_addr, len, "%s", inet_ntoa(myaddr.sin_addr));
-	ip_addr[len - 1] = '\0';
+	snprintf(new_option, sizeof(new_option) - 1,
+			"mountaddr=%s", inet_ntoa(maddr.sin_addr));
 
-	return 1;
+	if (po_append(options, new_option) == PO_SUCCEEDED)
+		return 1;
+	return 0;
 }
 
 /*
- * Walk through our mount options string, and indicate the presence
- * of 'bg', 'retry=', 'addr=', and 'clientaddr='.
+ * Returns zero if the "lock" option is in effect, but statd
+ * can't be started.  Otherwise, returns 1.
  */
-static void extract_interesting_options(char *opts)
+static int verify_lock_option(struct mount_options *options)
 {
-	char *opt, *opteq;
-	int val;
-
-	opts = xstrdup(opts);
-
-	for (opt = strtok(opts, ","); opt; opt = strtok(NULL, ",")) {
-		if ((opteq = strchr(opt, '='))) {
-			val = atoi(opteq + 1);
-			*opteq = '\0';
-			if (strcmp(opt, "bg") == 0)
-				bg_opt++;
-			else if (strcmp(opt, "retry") == 0)
-				retry_opt = val;
-			else if (strcmp(opt, "addr") == 0)
-				addr_opt++;
-			else if (strcmp(opt, "clientaddr") == 0)
-				ca_opt++;
-		} else {
-			if (strcmp(opt, "bg") == 0)
-				bg_opt++;
-		}
+	if (po_rightmost(options, "nolock", "lock") == PO_KEY1_RIGHTMOST)
+		return 1;
+
+	if (!start_statd()) {
+		nfs_error(_("%s: rpc.statd is not running but is "
+			    "required for remote locking."), progname);
+		nfs_error(_("%s: Either use '-o nolock' to keep "
+			    "locks local, or start statd."), progname);
+		return 0;
 	}
 
-	free(opts);
+	return 1;
 }
 
 /*
- * Append the 'addr=' option to the options string.
+ * Set up mandatory NFS mount options.
  *
- * Returns 1 if 'addr=' option created successfully;
- * otherwise zero.
+ * Returns 1 if successful; otherwise zero.
  */
-static int append_addr_opt(const char *spec, char **extra_opts)
+static int nfs_validate_options(struct nfsmount_info *mi)
 {
-	static char hostdir[1024], new_opts[1024];
-	char *hostname, *dirname, *s, *old_opts;
-	struct sockaddr_in addr;
+	struct sockaddr_in saddr;
 
-	if (strlen(spec) >= sizeof(hostdir)) {
-		nfs_error(_("%s: excessively long host:dir argument\n"),
-				progname);
+	if (!fill_ipv4_sockaddr(mi->hostname, &saddr))
 		return 0;
+
+	if (strncmp(mi->type, "nfs4", 4) == 0) {
+		if (!append_clientaddr_option(&saddr, mi->options))
+			return 0;
+	} else {
+		if (!fix_mounthost_option(mi->options))
+			return 0;
+		if (!mi->fake && !verify_lock_option(mi->options))
+			return 0;
 	}
-	strcpy(hostdir, spec);
-	if (parse_devname(hostdir, &hostname, &dirname)) {
-		nfs_error(_("%s: parsing host:dir argument failed\n"),
-				progname);
+
+	if (!append_addr_option(&saddr, mi->options))
 		return 0;
+
+	return 1;
+}
+
+/*
+ * Distinguish between permanent and temporary errors.
+ *
+ * Returns 0 if the passed-in error is temporary, thus the
+ * mount system call should be retried; returns one if the
+ * passed-in error is permanent, thus the mount system call
+ * should not be retried.
+ */
+static int is_permanent_error(int error)
+{
+	switch (error) {
+	case ESTALE:
+	case ETIMEDOUT:
+	case ECONNREFUSED:
+		return 0;	/* temporary */
+	default:
+		return 1;	/* permanent */
 	}
+}
 
-	if (!fill_ipv4_sockaddr(hostname, &addr))
-		return 0;
+/*
+ * Reconstruct the mount option string based on a portmapper probe
+ * of the server.  Returns one if the server's portmapper returned
+ * something we can use, otherwise zero.
+ *
+ * To handle version and transport protocol fallback properly, we
+ * need to parse some of the mount options in order to set up a
+ * portmap probe.  Mount options that rewrite_mount_options()
+ * doesn't recognize are left alone.
+ *
+ * Returns a new group of mount options if successful; otherwise
+ * NULL is returned if some failure occurred.
+ */
+static struct mount_options *rewrite_mount_options(char *str)
+{
+	struct mount_options *options;
+	char *option, new_option[64];
+	clnt_addr_t mnt_server = { };
+	clnt_addr_t nfs_server = { };
+	int p;
+
+	errno = EIO;
+
+	options = po_split(str);
+	if (!options)
+		return NULL;
+
+	option = po_get(options, "addr");
+	if (option) {
+		nfs_server.saddr.sin_family = AF_INET;
+		if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr))
+			goto err;
+	} else
+		goto err;
+
+	option = po_get(options, "mountaddr");
+	if (option) {
+		mnt_server.saddr.sin_family = AF_INET;
+		if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr))
+			goto err;
+	} else
+		memcpy(&mnt_server.saddr, &nfs_server.saddr,
+				sizeof(mnt_server.saddr));
+
+	option = po_get(options, "mountport");
+	if (option)
+		mnt_server.pmap.pm_port = atoi(option);
+	mnt_server.pmap.pm_prog = MOUNTPROG;
+	option = po_get(options, "mountvers");
+	if (option)
+		mnt_server.pmap.pm_vers = atoi(option);
+
+	option = po_get(options, "port");
+	if (option) {
+		nfs_server.pmap.pm_port = atoi(option);
+		po_remove_all(options, "port");
+	}
+	nfs_server.pmap.pm_prog = NFS_PROGRAM;
 
-	/* add IP address to mtab options for use when unmounting */
-	s = inet_ntoa(addr.sin_addr);
-	old_opts = *extra_opts;
-	if (!old_opts)
-		old_opts = "";
-	if (strlen(old_opts) + strlen(s) + 10 >= sizeof(new_opts)) {
-		nfs_error(_("%s: excessively long option argument\n"),
-				progname);
-		return 0;
+	option = po_get(options, "nfsvers");
+	if (option) {
+		nfs_server.pmap.pm_vers = atoi(option);
+		po_remove_all(options, "nfsvers");
+	}
+	option = po_get(options, "vers");
+	if (option) {
+		nfs_server.pmap.pm_vers = atoi(option);
+		po_remove_all(options, "vers");
+	}
+	option = po_get(options, "proto");
+	if (option) {
+		if (strcmp(option, "tcp") == 0) {
+			nfs_server.pmap.pm_prot = IPPROTO_TCP;
+			po_remove_all(options, "proto");
+		}
+		if (strcmp(option, "udp") == 0) {
+			nfs_server.pmap.pm_prot = IPPROTO_UDP;
+			po_remove_all(options, "proto");
+		}
 	}
-	snprintf(new_opts, sizeof(new_opts), "%s%saddr=%s",
-		 old_opts, *old_opts ? "," : "", s);
-	*extra_opts = xstrdup(new_opts);
+	p = po_rightmost(options, "tcp", "udp");
+	switch (p) {
+	case PO_KEY2_RIGHTMOST:
+		nfs_server.pmap.pm_prot = IPPROTO_UDP;
+		break;
+	case PO_KEY1_RIGHTMOST:
+		nfs_server.pmap.pm_prot = IPPROTO_TCP;
+		break;
+	}
+	po_remove_all(options, "tcp");
+	po_remove_all(options, "udp");
 
-	return 1;
+	if (!probe_bothports(&mnt_server, &nfs_server)) {
+		errno = ESPIPE;
+		goto err;
+	}
+
+	snprintf(new_option, sizeof(new_option) - 1,
+		 "nfsvers=%lu", nfs_server.pmap.pm_vers);
+	if (po_append(options, new_option) == PO_FAILED)
+		goto err;
+
+	if (nfs_server.pmap.pm_prot == IPPROTO_TCP)
+		snprintf(new_option, sizeof(new_option) - 1,
+			 "proto=tcp");
+	else
+		snprintf(new_option, sizeof(new_option) - 1,
+			 "proto=udp");
+	if (po_append(options, new_option) == PO_FAILED)
+		goto err;
+
+	if (nfs_server.pmap.pm_port != NFS_PORT) {
+		snprintf(new_option, sizeof(new_option) - 1,
+			 "port=%lu", nfs_server.pmap.pm_port);
+		if (po_append(options, new_option) == PO_FAILED)
+			goto err;
+
+	}
+
+	errno = 0;
+	return options;
+
+err:
+	po_destroy(options);
+	return NULL;
 }
 
 /*
- * Append the 'clientaddr=' option to the options string.
+ * Do the mount(2) system call.
  *
- * Returns 1 if 'clientaddr=' option created successfully;
- * otherwise zero.
+ * Returns 1 if successful, otherwise zero.
+ * "errno" is set to reflect the individual error.
  */
-static int append_clientaddr_opt(const char *spec, char **extra_opts)
+static int nfs_sys_mount(const struct nfsmount_info *mi, const char *type,
+			 const char *options)
 {
-	static char new_opts[1024], cbuf[1024];
-	static char ip_addr[16] = "127.0.0.1";
+	int result;
+
+	result = mount(mi->spec, mi->node, type,
+				mi->flags & ~(MS_USER|MS_USERS), options);
+	if (verbose && result) {
+		int save = errno;
+		nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
+		errno = save;
+	}
+	return !result;
+}
 
-	if (!get_my_ipv4addr(ip_addr, sizeof(ip_addr)))
+/*
+ * Retry an NFS mount that failed because the requested service isn't
+ * available on the server.
+ *
+ * Returns 1 if successful.  Otherwise, returns zero.
+ * "errno" is set to reflect the individual error.
+ *
+ * Side effect: If the retry is successful, both 'options' and
+ * 'extra_opts' are updated to reflect the mount options that worked.
+ * If the retry fails, 'options' and 'extra_opts' are left unchanged.
+ */
+static int nfs_retry_nfs23mount(struct nfsmount_info *mi)
+{
+	struct mount_options *retry_options;
+	char *retry_str = NULL;
+	char **extra_opts = mi->extra_opts;
+
+	retry_options = rewrite_mount_options(*extra_opts);
+	if (!retry_options)
 		return 0;
 
-	/* Ensure we have enough padding for the following strcat()s */
-	if (strlen(*extra_opts) + strlen(ip_addr) + 10 >= sizeof(new_opts)) {
-		nfs_error(_("%s: excessively long option argument"),
-				progname);
+	if (po_join(retry_options, &retry_str) == PO_FAILED) {
+		po_destroy(retry_options);
+		errno = EIO;
 		return 0;
 	}
 
-	strcat(new_opts, *extra_opts);
-
-	snprintf(cbuf, sizeof(cbuf) - 1, "%sclientaddr=%s",
-			*extra_opts ? "," : "", ip_addr);
-	strcat(new_opts, cbuf);
+	if (verbose)
+		printf(_("%s: text-based options (retry): '%s'\n"),
+			progname, retry_str);
 
-	*extra_opts = xstrdup(new_opts);
+	if (!nfs_sys_mount(mi, "nfs", retry_str)) {
+		po_destroy(retry_options);
+		free(retry_str);
+		return 0;
+	}
 
+	free(*extra_opts);
+	*extra_opts = retry_str;
+	po_replace(mi->options, retry_options);
 	return 1;
 }
 
 /*
- * nfsmount_s - Mount an NFSv2 or v3 file system using C string options
+ * Attempt an NFSv2/3 mount via a mount(2) system call.  If the kernel
+ * claims the requested service isn't supported on the server, probe
+ * the server to see what's supported, rewrite the mount options,
+ * and retry the request.
  *
- * @spec:	C string hostname:path specifying remoteshare to mount
- * @node:	C string pathname of local mounted on directory
- * @flags:	MS_ style flags
- * @extra_opts:	pointer to C string containing fs-specific mount options
- *		(possibly also a return argument)
- * @fake:	flag indicating whether to carry out the whole operation
- * @bg:		one if this is a backgrounded mount attempt
+ * Returns 1 if successful.  Otherwise, returns zero.
+ * "errno" is set to reflect the individual error.
  *
- * XXX: need to handle bg, fg, and retry options.
+ * Side effect: If the retry is successful, both 'options' and
+ * 'extra_opts' are updated to reflect the mount options that worked.
+ * If the retry fails, 'options' and 'extra_opts' are left unchanged.
  */
-int nfsmount_s(const char *spec, const char *node, int flags,
-		char **extra_opts, int fake, int bg)
+static int nfs_try_nfs23mount(struct nfsmount_info *mi)
 {
-	int retval = EX_FAIL;
-
-	extract_interesting_options(*extra_opts);
+	char **extra_opts = mi->extra_opts;
 
-	if (!bg && addr_opt) {
-		nfs_error(_("%s: Illegal option: 'addr='"), progname);
-		goto fail;
+	if (po_join(mi->options, extra_opts) == PO_FAILED) {
+		errno = EIO;
+		return 0;
 	}
 
-	if (!append_addr_opt(spec, extra_opts))
-		goto fail;
-
 	if (verbose)
 		printf(_("%s: text-based options: '%s'\n"),
 			progname, *extra_opts);
 
-	if (!fake) {
-		if (mount(spec, node, "nfs",
-				flags & ~(MS_USER|MS_USERS), *extra_opts)) {
-			mount_error(spec, node, errno);
-			goto fail;
-		}
+	if (mi->fake)
+		return 1;
+
+	if (nfs_sys_mount(mi, "nfs", *extra_opts))
+		return 1;
+
+	/*
+	 * The kernel returns EOPNOTSUPP if the RPC bind failed,
+	 * and EPROTONOSUPPORT if the version isn't supported.
+	 */
+	if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT)
+		return 0;
+
+	return nfs_retry_nfs23mount(mi);
+}
+
+/*
+ * Attempt an NFS v4 mount via a mount(2) system call.
+ *
+ * Returns 1 if successful.  Otherwise, returns zero.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_try_nfs4mount(struct nfsmount_info *mi)
+{
+	char **extra_opts = mi->extra_opts;
+
+	if (po_join(mi->options, extra_opts) == PO_FAILED) {
+		errno = EIO;
+		return 0;
 	}
 
-	return 0;
+	if (verbose)
+		printf(_("%s: text-based options: '%s'\n"),
+			progname, *extra_opts);
 
-fail:
-	return retval;
+	if (mi->fake)
+		return 1;
+
+	return nfs_sys_mount(mi, "nfs4", *extra_opts);
 }
 
 /*
- * nfs4mount_s - Mount an NFSv4 file system using C string options
+ * Perform either an NFSv2/3 mount, or an NFSv4 mount system call.
  *
- * @spec:	C string hostname:path specifying remoteshare to mount
- * @node:	C string pathname of local mounted on directory
- * @flags:	MS_ style flags
- * @extra_opts:	pointer to C string containing fs-specific mount options
- *		(possibly also a return argument)
- * @fake:	flag indicating whether to carry out the whole operation
- * @child:	one if this is a backgrounded mount
+ * Returns 1 if successful.  Otherwise, returns zero.
+ * "errno" is set to reflect the individual error.
+ */
+static int nfs_try_mount(struct nfsmount_info *mi)
+{
+	if (strncmp(mi->type, "nfs4", 4) == 0)
+		return nfs_try_nfs4mount(mi);
+	else
+		return nfs_try_nfs23mount(mi);
+}
+
+/*
+ * Handle "foreground" NFS mounts.
  *
- * XXX: need to handle bg, fg, and retry options.
+ * Retry the mount request for as long as the 'retry=' option says.
  *
+ * Returns a valid mount command exit code.
  */
-int nfs4mount_s(const char *spec, const char *node, int flags,
-		char **extra_opts, int fake, int child)
+static int nfsmount_fg(struct nfsmount_info *mi)
 {
-	int retval = EX_FAIL;
+	unsigned int secs = 1;
+	time_t timeout;
 
-	extract_interesting_options(*extra_opts);
+	timeout = nfs_parse_retry_option(mi->options,
+					 NFS_DEF_FG_TIMEOUT_MINUTES);
+	if (verbose)
+		printf(_("%s: timeout set for %s"),
+			progname, ctime(&timeout));
 
-	if (addr_opt) {
-		nfs_error(_("%s: Illegal option: 'addr='"), progname);
-		goto fail;
-	}
+	for (;;) {
+		if (nfs_try_mount(mi))
+			return EX_SUCCESS;
 
-	if (ca_opt) {
-		nfs_error(_("%s: Illegal option: 'clientaddr='"), progname);
-		goto fail;
-	}
+		if (is_permanent_error(errno))
+			break;
 
-	if (!append_addr_opt(spec, extra_opts))
-		goto fail;
+		if (time(NULL) > timeout) {
+			errno = ETIMEDOUT;
+			break;
+		}
 
-	if (!append_clientaddr_opt(spec, extra_opts))
-		goto fail;
+		if (errno != ETIMEDOUT) {
+			if (sleep(secs))
+				break;
+			secs <<= 1;
+			if (secs > 10)
+				secs = 10;
+		}
+	};
 
-	if (verbose)
-		printf(_("%s: text-based options: '%s'\n"),
-			progname, *extra_opts);
+	mount_error(mi->spec, mi->node, errno);
+	return EX_FAIL;
+}
 
-	if (!fake) {
-		if (mount(spec, node, "nfs4",
-				flags & ~(MS_USER|MS_USERS), *extra_opts)) {
-			mount_error(spec, node, errno);
-			goto fail;
-		}
+/*
+ * Handle "background" NFS mount [first try]
+ *
+ * Returns a valid mount command exit code.
+ *
+ * EX_BG should cause the caller to fork and invoke nfsmount_child.
+ */
+static int nfsmount_parent(struct nfsmount_info *mi)
+{
+	if (nfs_try_mount(mi))
+		return EX_SUCCESS;
+
+	if (is_permanent_error(errno)) {
+		mount_error(mi->spec, mi->node, errno);
+		return EX_FAIL;
 	}
 
-	return 0;
+	sys_mount_errors(mi->hostname, errno, 1, 1);
+	return EX_BG;
+}
+
+/*
+ * Handle "background" NFS mount [retry daemon]
+ *
+ * Returns a valid mount command exit code: EX_SUCCESS if successful,
+ * EX_FAIL if a failure occurred.  There's nothing to catch the
+ * error return, though, so we use sys_mount_errors to log the
+ * failure.
+ */
+static int nfsmount_child(struct nfsmount_info *mi)
+{
+	unsigned int secs = 1;
+	time_t timeout;
+
+	timeout = nfs_parse_retry_option(mi->options,
+					 NFS_DEF_BG_TIMEOUT_MINUTES);
+
+	for (;;) {
+		if (sleep(secs))
+			break;
+		secs <<= 1;
+		if (secs > 120)
+			secs = 120;
+
+		if (nfs_try_mount(mi))
+			return EX_SUCCESS;
+
+		if (is_permanent_error(errno))
+			break;
+
+		if (time(NULL) > timeout)
+			break;
+
+		sys_mount_errors(mi->hostname, errno, 1, 1);
+	};
+
+	sys_mount_errors(mi->hostname, errno, 1, 0);
+	return EX_FAIL;
+}
+
+/*
+ * Handle "background" NFS mount
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfsmount_bg(struct nfsmount_info *mi)
+{
+	if (!mi->child)
+		return nfsmount_parent(mi);
+	else
+		return nfsmount_child(mi);
+}
+
+/*
+ * Process mount options and try a mount system call.
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfsmount_start(struct nfsmount_info *mi)
+{
+	if (!nfs_validate_options(mi))
+		return EX_FAIL;
+
+	if (po_rightmost(mi->options, "bg", "fg") == PO_KEY1_RIGHTMOST)
+		return nfsmount_bg(mi);
+	else
+		return nfsmount_fg(mi);
+}
+
+/**
+ * nfsmount_string - Mount an NFS file system using C string options
+ * @spec: C string specifying remote share to mount ("hostname:path")
+ * @node: C string pathname of local mounted-on directory
+ * @type: C string that represents file system type ("nfs" or "nfs4")
+ * @flags: MS_ style mount flags
+ * @extra_opts:	pointer to C string containing fs-specific mount options
+ *		(input and output argument)
+ * @fake: flag indicating whether to carry out the whole operation
+ * @child: one if this is a mount daemon (bg)
+ */
+int nfsmount_string(const char *spec, const char *node, const char *type,
+		    int flags, char **extra_opts, int fake, int child)
+{
+	struct nfsmount_info mi = {
+		.spec		= spec,
+		.node		= node,
+		.type		= type,
+		.extra_opts	= extra_opts,
+		.flags		= flags,
+		.fake		= fake,
+		.child		= child,
+	};
+	int retval = EX_FAIL;
+
+	if (!nfs_parse_devname(&mi))
+		return retval;
+
+	mi.options = po_split(*extra_opts);
+	if (mi.options) {
+		retval = nfsmount_start(&mi);
+		po_destroy(mi.options);
+	} else
+		nfs_error(_("%s: internal option parsing error"), progname);
 
-fail:
+	free(mi.hostname);
 	return retval;
 }