X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmount%2Fnetwork.c;h=afa47a4dd7e22cb4c1993cb5a0d1f12e01b94191;hp=49d3c6b26d63c33c4b83ae6f497e1fb2a809f87f;hb=265f2708bdc6030250c13d46d70ed689c140c34e;hpb=bda03ca689ff8b410a778299e5c6f4a14fcc85f8

diff --git a/utils/mount/network.c b/utils/mount/network.c
index 49d3c6b..afa47a4 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -21,6 +21,10 @@
  *
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <ctype.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -29,29 +33,23 @@
 #include <errno.h>
 #include <netdb.h>
 #include <time.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <netinet/in.h>
 #include <rpc/rpc.h>
 #include <rpc/pmap_prot.h>
 #include <rpc/pmap_clnt.h>
-#include <sys/socket.h>
 
 #include "xcommon.h"
 #include "mount.h"
 #include "nls.h"
 #include "nfs_mount.h"
 #include "mount_constants.h"
+#include "nfsrpc.h"
 #include "network.h"
 
-#ifdef HAVE_RPCSVC_NFS_PROT_H
-#include <rpcsvc/nfs_prot.h>
-#else
-#include <linux/nfs.h>
-#define nfsstat nfs_stat
-#endif
-
-#ifndef NFS_PORT
-#define NFS_PORT 2049
-#endif
-
 #define PMAP_TIMEOUT	(10)
 #define CONNECT_TIMEOUT	(20)
 #define MOUNT_TIMEOUT	(30)
@@ -64,6 +62,11 @@ extern int nfs_mount_data_version;
 extern char *progname;
 extern int verbose;
 
+static const char *nfs_ns_pgmtbl[] = {
+	"status",
+	NULL,
+};
+
 static const unsigned long nfs_to_mnt[] = {
 	0,
 	0,
@@ -139,6 +142,75 @@ static const unsigned long probe_mnt3_first[] = {
 	0,
 };
 
+static void nfs_set_port(struct sockaddr *sap, const unsigned short port)
+{
+	switch (sap->sa_family) {
+	case AF_INET:
+		((struct sockaddr_in *)sap)->sin_port = htons(port);
+		break;
+	case AF_INET6:
+		((struct sockaddr_in6 *)sap)->sin6_port = htons(port);
+		break;
+	default:
+		nfs_error(_("%s: unrecognized address family in %s"),
+			progname, __func__);
+	}
+}
+
+/**
+ * nfs_name_to_address - resolve hostname to an IPv4 or IPv6 socket address
+ * @hostname: pointer to C string containing DNS hostname to resolve
+ * @sap: pointer to buffer to fill with socket address
+ * @len: IN: size of buffer to fill; OUT: size of socket address
+ *
+ * Returns 1 and places a socket address at @sap if successful;
+ * otherwise zero.
+ */
+int nfs_name_to_address(const char *hostname,
+			const sa_family_t af_hint,
+			struct sockaddr *sap, socklen_t *salen)
+{
+	struct addrinfo *gai_results;
+	struct addrinfo gai_hint = {
+		.ai_family	= af_hint,
+		.ai_flags	= AI_ADDRCONFIG,
+	};
+	socklen_t len = *salen;
+	int error, ret = 0;
+
+	if (af_hint == AF_INET6)
+		gai_hint.ai_flags |= AI_V4MAPPED|AI_ALL;
+
+	*salen = 0;
+
+	error = getaddrinfo(hostname, NULL, &gai_hint, &gai_results);
+	if (error) {
+		nfs_error(_("%s: DNS resolution failed for %s: %s"),
+			progname, hostname, (error == EAI_SYSTEM ?
+				strerror(errno) : gai_strerror(error)));
+		return ret;
+	}
+
+	switch (gai_results->ai_addr->sa_family) {
+	case AF_INET:
+	case AF_INET6:
+		if (len >= gai_results->ai_addrlen) {
+			*salen = gai_results->ai_addrlen;
+			memcpy(sap, gai_results->ai_addr, *salen);
+			ret = 1;
+		}
+		break;
+	default:
+		/* things are really broken if we get here, so warn */
+		nfs_error(_("%s: unrecognized DNS resolution results for %s"),
+				progname, hostname);
+		break;
+	}
+
+	freeaddrinfo(gai_results);
+	return ret;
+}
+
 /**
  * nfs_gethostbyname - resolve a hostname to an IPv4 address
  * @hostname: pointer to a C string containing a DNS hostname
@@ -146,26 +218,104 @@ static const unsigned long probe_mnt3_first[] = {
  *
  * Returns 1 if successful, otherwise zero.
  */
-int nfs_gethostbyname(const char *hostname, struct sockaddr_in *saddr)
+int nfs_gethostbyname(const char *hostname, struct sockaddr_in *sin)
 {
-	struct hostent *hp;
+	socklen_t len = sizeof(*sin);
 
-	saddr->sin_family = AF_INET;
-	if (!inet_aton(hostname, &saddr->sin_addr)) {
-		if ((hp = gethostbyname(hostname)) == NULL) {
-			nfs_error(_("%s: can't get address for %s\n"),
-					progname, hostname);
-			return 0;
-		} else {
-			if (hp->h_length > sizeof(*saddr)) {
-				nfs_error(_("%s: got bad hp->h_length\n"),
-						progname);
-				hp->h_length = sizeof(*saddr);
+	return nfs_name_to_address(hostname, AF_INET,
+					(struct sockaddr *)sin, &len);
+}
+
+/**
+ * nfs_string_to_sockaddr - convert string address to sockaddr
+ * @address:	pointer to presentation format address to convert
+ * @addrlen:	length of presentation address
+ * @sap:	pointer to socket address buffer to fill in
+ * @salen:	IN: length of address buffer
+ *		OUT: length of converted socket address
+ *
+ * Convert a presentation format address string to a socket address.
+ * Similar to nfs_name_to_address(), but the DNS query is squelched,
+ * and won't make any noise if the getaddrinfo() call fails.
+ *
+ * Returns 1 and fills in @sap and @salen if successful; otherwise zero.
+ *
+ * See RFC 4038 section 5.1 or RFC 3513 section 2.2 for more details
+ * on presenting IPv6 addresses as text strings.
+ */
+int nfs_string_to_sockaddr(const char *address, const size_t addrlen,
+			   struct sockaddr *sap, socklen_t *salen)
+{
+	struct addrinfo *gai_results;
+	struct addrinfo gai_hint = {
+		.ai_flags	= AI_NUMERICHOST,
+	};
+	socklen_t len = *salen;
+	int ret = 0;
+
+	*salen = 0;
+
+	if (getaddrinfo(address, NULL, &gai_hint, &gai_results) == 0) {
+		switch (gai_results->ai_addr->sa_family) {
+		case AF_INET:
+		case AF_INET6:
+			if (len >= gai_results->ai_addrlen) {
+				*salen = gai_results->ai_addrlen;
+				memcpy(sap, gai_results->ai_addr, *salen);
+				ret = 1;
 			}
-			memcpy(&saddr->sin_addr, hp->h_addr, hp->h_length);
+			break;
 		}
+		freeaddrinfo(gai_results);
 	}
-	return 1;
+
+	return ret;
+}
+
+/**
+ * nfs_present_sockaddr - convert sockaddr to string
+ * @sap: pointer to socket address to convert
+ * @salen: length of socket address
+ * @buf: pointer to buffer to fill in
+ * @buflen: length of buffer
+ *
+ * Convert the passed-in sockaddr-style address to presentation format.
+ * The presentation format address is placed in @buf and is
+ * '\0'-terminated.
+ *
+ * Returns 1 if successful; otherwise zero.
+ *
+ * See RFC 4038 section 5.1 or RFC 3513 section 2.2 for more details
+ * on presenting IPv6 addresses as text strings.
+ */
+int nfs_present_sockaddr(const struct sockaddr *sap, const socklen_t salen,
+			 char *buf, const size_t buflen)
+{
+#ifdef HAVE_GETNAMEINFO
+	int result;
+
+	result = getnameinfo(sap, salen, buf, buflen,
+					NULL, 0, NI_NUMERICHOST);
+	if (!result)
+		return 1;
+
+	nfs_error(_("%s: invalid server address: %s"), progname,
+			gai_strerror(result));
+	return 0;
+#else	/* HAVE_GETNAMEINFO */
+	char *addr;
+
+	if (sap->sa_family == AF_INET) {
+		addr = inet_ntoa(((struct sockaddr_in *)sap)->sin_addr);
+		if (addr && strlen(addr) < buflen) {
+			strcpy(buf, addr);
+			return 1;
+		}
+	}
+
+	nfs_error(_("%s: invalid server address"), progname);
+	return 0;
+#endif	/* HAVE_GETNAMEINFO */
 }
 
 /*
@@ -296,119 +446,74 @@ err_connect:
 	return RPC_ANYSOCK;
 }
 
-/*
- * getport() is very similar to pmap_getport() with the exception that
- * this version tries to use an ephemeral port, since reserved ports are
- * not needed for GETPORT queries.  This conserves the very limited
- * reserved port space, which helps reduce failed socket binds
- * during mount storms.
- *
- * A side effect of calling this function is that rpccreateerr is set.
- */
-static unsigned short getport(struct sockaddr_in *saddr,
-				unsigned long program,
-				unsigned long version,
-				unsigned int proto)
+static void nfs_pp_debug(const struct sockaddr *sap, const socklen_t salen,
+			 const rpcprog_t program, const rpcvers_t version,
+			 const unsigned short protocol,
+			 const unsigned short port)
 {
-	struct sockaddr_in bind_saddr;
-	unsigned short port = 0;
-	int socket;
-	CLIENT *clnt = NULL;
-	enum clnt_stat stat;
- 
-	bind_saddr = *saddr;
-	bind_saddr.sin_port = htons(PMAPPORT);
-
-	socket = get_socket(&bind_saddr, proto, PMAP_TIMEOUT, FALSE, FALSE);
-	if (socket == RPC_ANYSOCK) {
-		if (proto == IPPROTO_TCP &&
-		    rpc_createerr.cf_error.re_errno == ETIMEDOUT)
-			rpc_createerr.cf_stat = RPC_TIMEDOUT;
-		return 0;
-	}
+	char buf[NI_MAXHOST];
 
-	switch (proto) {
-	case IPPROTO_UDP:
-		clnt = clntudp_bufcreate(&bind_saddr,
-					 PMAPPROG, PMAPVERS,
-					 RETRY_TIMEOUT, &socket,
-					 RPCSMALLMSGSIZE,
-					 RPCSMALLMSGSIZE);
-		break;
-	case IPPROTO_TCP:
-		clnt = clnttcp_create(&bind_saddr,
-				      PMAPPROG, PMAPVERS,
-				      &socket,
-				      RPCSMALLMSGSIZE, RPCSMALLMSGSIZE);
-		break;
-	}
-	if (clnt != NULL) {
-		struct pmap parms = {
-			.pm_prog	= program,
-			.pm_vers	= version,
-			.pm_prot	= proto,
-		};
-
-		stat = clnt_call(clnt, PMAPPROC_GETPORT,
-				 (xdrproc_t)xdr_pmap, (caddr_t)&parms,
-				 (xdrproc_t)xdr_u_short, (caddr_t)&port,
-				 TIMEOUT);
-		if (stat) {
-			clnt_geterr(clnt, &rpc_createerr.cf_error);
-			rpc_createerr.cf_stat = stat;
-		}
-		clnt_destroy(clnt);
-		if (stat != RPC_SUCCESS)
-			port = 0;
-		else if (port == 0)
-			rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
+	if (!verbose)
+		return;
+
+	if (nfs_present_sockaddr(sap, salen, buf, sizeof(buf)) == 0) {
+		buf[0] = '\0';
+		strcat(buf, "unknown host");
 	}
-	close(socket);
 
-	return port;
+	fprintf(stderr, _("%s: trying %s prog %ld vers %ld prot %s port %d\n"),
+			progname, buf, program, version,
+			(protocol == IPPROTO_UDP ? _("UDP") : _("TCP")),
+			port);
 }
 
 /*
  * Use the portmapper to discover whether or not the service we want is
  * available. The lists 'versions' and 'protos' define ordered sequences
  * of service versions and udp/tcp protocols to probe for.
+ *
+ * Returns 1 if the requested service port is unambiguous and pingable;
+ * @pmap is filled in with the version, port, and transport protocol used
+ * during the successful ping.  Note that if a port is already specified
+ * in @pmap and it matches the rpcbind query result, nfs_probe_port() does
+ * not perform an RPC ping.
+ * 
+ * If an error occurs or the requested service isn't available, zero is
+ * returned; rpccreateerr.cf_stat is set to reflect the nature of the error.
  */
-static int probe_port(clnt_addr_t *server, const unsigned long *versions,
-			const unsigned int *protos)
+static int nfs_probe_port(const struct sockaddr *sap, const socklen_t salen,
+			  struct pmap *pmap, const unsigned long *versions,
+			  const unsigned int *protos)
 {
-	struct sockaddr_in *saddr = &server->saddr;
-	struct pmap *pmap = &server->pmap;
+	struct sockaddr_storage address;
+	struct sockaddr *saddr = (struct sockaddr *)&address;
 	const unsigned long prog = pmap->pm_prog, *p_vers;
 	const unsigned int prot = (u_int)pmap->pm_prot, *p_prot;
 	const u_short port = (u_short) pmap->pm_port;
 	unsigned long vers = pmap->pm_vers;
 	unsigned short p_port;
 
+	memcpy(saddr, sap, salen);
 	p_prot = prot ? &prot : protos;
 	p_vers = vers ? &vers : versions;
 	rpc_createerr.cf_stat = 0;
+
 	for (;;) {
-		p_port = getport(saddr, prog, *p_vers, *p_prot);
+		p_port = nfs_getport(saddr, salen, prog, *p_vers, *p_prot);
 		if (p_port) {
 			if (!port || port == p_port) {
-				saddr->sin_port = htons(p_port);
-				if (verbose) {
-					printf(_("%s: trying %s prog %ld vers "
-						"%ld prot %s port %d\n"),
-						progname,
-						inet_ntoa(saddr->sin_addr),
-						prog, *p_vers,
-						*p_prot == IPPROTO_UDP ?
-							_("UDP") : _("TCP"),
-						p_port);
-                                }
-				if (clnt_ping(saddr, prog, *p_vers, *p_prot, NULL))
+				nfs_set_port(saddr, p_port);
+				nfs_pp_debug(saddr, salen, prog, *p_vers,
+						*p_prot, p_port);
+				if (nfs_rpc_ping(saddr, salen, prog,
+							*p_vers, *p_prot, NULL))
 					goto out_ok;
-				if (rpc_createerr.cf_stat == RPC_TIMEDOUT)
-					goto out_bad;
 			}
 		}
-		if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED)
+		if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED &&
+		    rpc_createerr.cf_stat != RPC_TIMEDOUT &&
+		    rpc_createerr.cf_stat != RPC_CANTRECV &&
+		    rpc_createerr.cf_stat != RPC_PROGVERSMISMATCH)
 			goto out_bad;
 
 		if (!prot) {
@@ -416,10 +521,10 @@ static int probe_port(clnt_addr_t *server, const unsigned long *versions,
 				continue;
 			p_prot = protos;
 		}
-		if (vers == pmap->pm_vers) {
-			p_vers = versions;
-			vers = 0;
-		}
+		if (rpc_createerr.cf_stat == RPC_TIMEDOUT ||
+		    rpc_createerr.cf_stat == RPC_CANTRECV)
+			goto out_bad;
+
 		if (vers || !*++p_vers)
 			break;
 	}
@@ -438,56 +543,114 @@ out_ok:
 	return 1;
 }
 
-static int probe_nfsport(clnt_addr_t *nfs_server)
+/*
+ * Probe a server's NFS service to determine which versions and
+ * transport protocols are supported.
+ *
+ * Returns 1 if the requested service port is unambiguous and pingable;
+ * @pmap is filled in with the version, port, and transport protocol used
+ * during the successful ping.  If all three are already specified, simply
+ * return success without an rpcbind query or RPC ping (we may be trying
+ * to mount an NFS service that is not advertised via rpcbind).
+ *
+ * If an error occurs or the requested service isn't available, zero is
+ * returned; rpccreateerr.cf_stat is set to reflect the nature of the error.
+ */
+static int nfs_probe_nfsport(const struct sockaddr *sap, const socklen_t salen,
+				struct pmap *pmap)
 {
-	struct pmap *pmap = &nfs_server->pmap;
-
 	if (pmap->pm_vers && pmap->pm_prot && pmap->pm_port)
 		return 1;
 
 	if (nfs_mount_data_version >= 4)
-		return probe_port(nfs_server, probe_nfs3_first, probe_tcp_first);
+		return nfs_probe_port(sap, salen, pmap,
+					probe_nfs3_first, probe_tcp_first);
 	else
-		return probe_port(nfs_server, probe_nfs2_only, probe_udp_only);
+		return nfs_probe_port(sap, salen, pmap,
+					probe_nfs2_only, probe_udp_only);
 }
 
-static int probe_mntport(clnt_addr_t *mnt_server)
+/*
+ * Probe a server's mountd service to determine which versions and
+ * transport protocols are supported.
+ *
+ * Returns 1 if the requested service port is unambiguous and pingable;
+ * @pmap is filled in with the version, port, and transport protocol used
+ * during the successful ping.  If all three are already specified, simply
+ * return success without an rpcbind query or RPC ping (we may be trying
+ * to mount an NFS service that is not advertised via rpcbind).
+ * 
+ * If an error occurs or the requested service isn't available, zero is
+ * returned; rpccreateerr.cf_stat is set to reflect the nature of the error.
+ */
+static int nfs_probe_mntport(const struct sockaddr *sap, const socklen_t salen,
+				struct pmap *pmap)
 {
-	struct pmap *pmap = &mnt_server->pmap;
-
 	if (pmap->pm_vers && pmap->pm_prot && pmap->pm_port)
 		return 1;
 
 	if (nfs_mount_data_version >= 4)
-		return probe_port(mnt_server, probe_mnt3_first, probe_udp_first);
+		return nfs_probe_port(sap, salen, pmap,
+					probe_mnt3_first, probe_udp_first);
 	else
-		return probe_port(mnt_server, probe_mnt1_first, probe_udp_only);
+		return nfs_probe_port(sap, salen, pmap,
+					probe_mnt1_first, probe_udp_only);
 }
 
-/**
- * probe_bothports - discover the RPC endpoints of mountd and NFS server
- * @mnt_server: pointer to address and pmap argument for mountd results
- * @nfs_server: pointer to address and pmap argument for NFS server
+/*
+ * Probe a server's mountd service to determine which versions and
+ * transport protocols are supported.  Invoked when the protocol
+ * version is already known for both the NFS and mountd service.
  *
- * Returns 1 if successful, otherwise zero if some error occurred.
- * Note that the arguments are both input and output arguments.
+ * Returns 1 and fills in both @pmap structs if the requested service
+ * ports are unambiguous and pingable.  Otherwise zero is returned;
+ * rpccreateerr.cf_stat is set to reflect the nature of the error.
+ */
+static int nfs_probe_version_fixed(const struct sockaddr *mnt_saddr,
+			const socklen_t mnt_salen,
+			struct pmap *mnt_pmap,
+			const struct sockaddr *nfs_saddr,
+			const socklen_t nfs_salen,
+			struct pmap *nfs_pmap)
+{
+	if (!nfs_probe_nfsport(nfs_saddr, nfs_salen, nfs_pmap))
+		return 0;
+	return nfs_probe_mntport(mnt_saddr, mnt_salen, mnt_pmap);
+}
+
+/**
+ * nfs_probe_bothports - discover the RPC endpoints of mountd and NFS server
+ * @mnt_saddr:	pointer to socket address of mountd server
+ * @mnt_salen:	length of mountd server's address
+ * @mnt_pmap:	IN: partially filled-in mountd RPC service tuple;
+ *		OUT: fully filled-in mountd RPC service tuple
+ * @nfs_saddr:	pointer to socket address of NFS server
+ * @nfs_salen:	length of NFS server's address
+ * @nfs_pmap:	IN: partially filled-in NFS RPC service tuple;
+ *		OUT: fully filled-in NFS RPC service tuple
  *
- * A side effect of calling this function is that rpccreateerr is set.
+ * Returns 1 and fills in both @pmap structs if the requested service
+ * ports are unambiguous and pingable.  Otherwise zero is returned;
+ * rpccreateerr.cf_stat is set to reflect the nature of the error.
  */
-int probe_bothports(clnt_addr_t *mnt_server, clnt_addr_t *nfs_server)
+int nfs_probe_bothports(const struct sockaddr *mnt_saddr,
+			const socklen_t mnt_salen,
+			struct pmap *mnt_pmap,
+			const struct sockaddr *nfs_saddr,
+			const socklen_t nfs_salen,
+			struct pmap *nfs_pmap)
 {
-	struct pmap *nfs_pmap = &nfs_server->pmap;
-	struct pmap *mnt_pmap = &mnt_server->pmap;
 	struct pmap save_nfs, save_mnt;
-	int res;
 	const unsigned long *probe_vers;
 
 	if (mnt_pmap->pm_vers && !nfs_pmap->pm_vers)
 		nfs_pmap->pm_vers = mntvers_to_nfs(mnt_pmap->pm_vers);
 	else if (nfs_pmap->pm_vers && !mnt_pmap->pm_vers)
 		mnt_pmap->pm_vers = nfsvers_to_mnt(nfs_pmap->pm_vers);
+
 	if (nfs_pmap->pm_vers)
-		goto version_fixed;
+		return nfs_probe_version_fixed(mnt_saddr, mnt_salen, mnt_pmap,
+					       nfs_saddr, nfs_salen, nfs_pmap);
 
 	memcpy(&save_nfs, nfs_pmap, sizeof(save_nfs));
 	memcpy(&save_mnt, mnt_pmap, sizeof(save_mnt));
@@ -496,9 +659,9 @@ int probe_bothports(clnt_addr_t *mnt_server, clnt_addr_t *nfs_server)
 
 	for (; *probe_vers; probe_vers++) {
 		nfs_pmap->pm_vers = mntvers_to_nfs(*probe_vers);
-		if ((res = probe_nfsport(nfs_server) != 0)) {
-			mnt_pmap->pm_vers = nfsvers_to_mnt(nfs_pmap->pm_vers);
-			if ((res = probe_mntport(mnt_server)) != 0)
+		if (nfs_probe_nfsport(nfs_saddr, nfs_salen, nfs_pmap) != 0) {
+			mnt_pmap->pm_vers = *probe_vers;
+			if (nfs_probe_mntport(mnt_saddr, mnt_salen, mnt_pmap) != 0)
 				return 1;
 			memcpy(mnt_pmap, &save_mnt, sizeof(*mnt_pmap));
 		}
@@ -507,38 +670,47 @@ int probe_bothports(clnt_addr_t *mnt_server, clnt_addr_t *nfs_server)
 		case RPC_PROGNOTREGISTERED:
 			break;
 		default:
-			goto out_bad;
+			return 0;
 		}
 		memcpy(nfs_pmap, &save_nfs, sizeof(*nfs_pmap));
 	}
 
-out_bad:
 	return 0;
-
-version_fixed:
-	if (!probe_nfsport(nfs_server))
-		goto out_bad;
-	return probe_mntport(mnt_server);
 }
 
-static int probe_statd(void)
+/**
+ * probe_bothports - discover the RPC endpoints of mountd and NFS server
+ * @mnt_server: pointer to address and pmap argument for mountd results
+ * @nfs_server: pointer to address and pmap argument for NFS server
+ *
+ * This is the legacy API that takes "clnt_addr_t" for both servers,
+ * but supports only AF_INET addresses.
+ *
+ * Returns 1 and fills in the pmap field in both clnt_addr_t structs
+ * if the requested service ports are unambiguous and pingable.
+ * Otherwise zero is returned; rpccreateerr.cf_stat is set to reflect
+ * the nature of the error.
+ */
+int probe_bothports(clnt_addr_t *mnt_server, clnt_addr_t *nfs_server)
 {
-	struct sockaddr_in addr;
-	unsigned short port;
-
-	memset(&addr, 0, sizeof(addr));
-	addr.sin_family = AF_INET;
-	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-	port = getport(&addr, 100024, 1, IPPROTO_UDP);
-
-	if (port == 0)
-		return 0;
-	addr.sin_port = htons(port);
+	return nfs_probe_bothports((struct sockaddr *)&mnt_server->saddr,
+					sizeof(mnt_server->saddr),
+					&mnt_server->pmap,
+					(struct sockaddr *)&nfs_server->saddr,
+					sizeof(nfs_server->saddr),
+					&nfs_server->pmap);
+}
 
-	if (clnt_ping(&addr, 100024, 1, IPPROTO_UDP, NULL) <= 0)
-		return 0;
+static int nfs_probe_statd(void)
+{
+	struct sockaddr_in addr = {
+		.sin_family		= AF_INET,
+		.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
+	};
+	rpcprog_t program = nfs_getrpcbyname(NSMPROG, nfs_ns_pgmtbl);
 
-	return 1;
+	return nfs_getport_ping((struct sockaddr *)&addr, sizeof(addr),
+				program, (rpcvers_t)1, IPPROTO_UDP);
 }
 
 /**
@@ -552,14 +724,26 @@ int start_statd(void)
 	struct stat stb;
 #endif
 
-	if (probe_statd())
+	if (nfs_probe_statd())
 		return 1;
 
 #ifdef START_STATD
 	if (stat(START_STATD, &stb) == 0) {
 		if (S_ISREG(stb.st_mode) && (stb.st_mode & S_IXUSR)) {
-			system(START_STATD);
-			if (probe_statd())
+			pid_t pid = fork();
+			switch (pid) {
+			case 0: /* child */
+				execl(START_STATD, START_STATD, NULL);
+				exit(1);
+			case -1: /* error */
+				nfs_error(_("fork failed: %s"),
+							strerror(errno));
+				break;
+			default: /* parent */
+				waitpid(pid, NULL,0);
+				break;
+			}
+			if (nfs_probe_statd())
 				return 1;
 		}
 	}
@@ -581,31 +765,23 @@ int start_statd(void)
  */
 int nfs_call_umount(clnt_addr_t *mnt_server, dirpath *argp)
 {
+	struct sockaddr *sap = (struct sockaddr *)&mnt_server->saddr;
+	socklen_t salen = sizeof(mnt_server->saddr);
+	struct pmap *pmap = &mnt_server->pmap;
 	CLIENT *clnt;
 	enum clnt_stat res = 0;
 	int msock;
 
-	switch (mnt_server->pmap.pm_vers) {
-	case 3:
-	case 2:
-	case 1:
-		if (!probe_mntport(mnt_server))
-			return 0;
-		clnt = mnt_openclnt(mnt_server, &msock);
-		if (!clnt)
-			return 0;
-		res = clnt_call(clnt, MOUNTPROC_UMNT,
-				(xdrproc_t)xdr_dirpath, (caddr_t)argp,
-				(xdrproc_t)xdr_void, NULL,
-				TIMEOUT);
-		mnt_closeclnt(clnt, msock);
-		if (res == RPC_SUCCESS)
-			return 1;
-		break;
-	default:
-		res = RPC_SUCCESS;
-		break;
-	}
+	if (!nfs_probe_mntport(sap, salen, pmap))
+		return 0;
+	clnt = mnt_openclnt(mnt_server, &msock);
+	if (!clnt)
+		return 0;
+	res = clnt_call(clnt, MOUNTPROC_UMNT,
+			(xdrproc_t)xdr_dirpath, (caddr_t)argp,
+			(xdrproc_t)xdr_void, NULL,
+			TIMEOUT);
+	mnt_closeclnt(clnt, msock);
 
 	if (res == RPC_SUCCESS)
 		return 1;
@@ -681,9 +857,9 @@ void mnt_closeclnt(CLIENT *clnt, int msock)
  * @prot: target RPC protocol
  * @caddr: filled in with our network address
  *
- * Sigh... getport() doesn't actually check the version number.
+ * Sigh... GETPORT queries don't actually check the version number.
  * In order to make sure that the server actually supports the service
- * we're requesting, we open and RPC client, and fire off a NULL
+ * we're requesting, we open an RPC client, and fire off a NULL
  * RPC call.
  *
  * caddr is the network address that the server will use to call us back.
@@ -761,35 +937,120 @@ int clnt_ping(struct sockaddr_in *saddr, const unsigned long prog,
 		return 0;
 }
 
-/**
- * get_client_address - acquire our local network address
- * @saddr: server's address
- * @caddr: filled in with our network address
- *
- * Discover a network address that the server will use to call us back.
- * On multi-homed clients, this address depends on which NIC we use to
- * route requests to the server.
+/*
+ * Try a getsockname() on a connected datagram socket.
  *
- * Use a connected datagram socket so as not to leave a socket in TIME_WAIT.
+ * Returns 1 and fills in @buf if successful; otherwise, zero.
  *
- * Returns one if successful, otherwise zero.
+ * A connected datagram socket prevents leaving a socket in TIME_WAIT.
+ * This conserves the ephemeral port number space, helping reduce failed
+ * socket binds during mount storms.
  */
-int get_client_address(struct sockaddr_in *saddr, struct sockaddr_in *caddr)
+static int nfs_ca_sockname(const struct sockaddr *sap, const socklen_t salen,
+			   struct sockaddr *buf, socklen_t *buflen)
 {
-	socklen_t len = sizeof(*caddr);
-	int socket, err;
+	struct sockaddr_in sin = {
+		.sin_family		= AF_INET,
+		.sin_addr.s_addr	= htonl(INADDR_ANY),
+	};
+	struct sockaddr_in6 sin6 = {
+		.sin6_family		= AF_INET6,
+		.sin6_addr		= IN6ADDR_ANY_INIT,
+	};
+	int sock;
 
-	socket = get_socket(saddr, IPPROTO_UDP, CONNECT_TIMEOUT, FALSE, TRUE);
-	if (socket == RPC_ANYSOCK)
+	sock = socket(sap->sa_family, SOCK_DGRAM, IPPROTO_UDP);
+	if (sock < 0)
 		return 0;
 
-	err = getsockname(socket, caddr, &len);
-	close(socket);
+	switch (sap->sa_family) {
+	case AF_INET:
+		if (bind(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
+			close(sock);
+			return 0;
+		}
+		break;
+	case AF_INET6:
+		if (bind(sock, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
+			close(sock);
+			return 0;
+		}
+		break;
+	default:
+		errno = EAFNOSUPPORT;
+		return 0;
+	}
 
-	if (err && verbose) {
-		nfs_error(_("%s: getsockname failed: %s"),
-				progname, strerror(errno));
+	if (connect(sock, sap, salen) < 0) {
+		close(sock);
 		return 0;
 	}
+
+	return !getsockname(sock, buf, buflen);
+}
+
+/*
+ * Try to generate an address that prevents the server from calling us.
+ *
+ * Returns 1 and fills in @buf if successful; otherwise, zero.
+ */
+static int nfs_ca_gai(const struct sockaddr *sap, const socklen_t salen,
+		      struct sockaddr *buf, socklen_t *buflen)
+{
+	struct addrinfo *gai_results;
+	struct addrinfo gai_hint = {
+		.ai_family	= sap->sa_family,
+		.ai_flags	= AI_PASSIVE,	/* ANYADDR */
+	};
+
+	if (getaddrinfo(NULL, "", &gai_hint, &gai_results))
+		return 0;
+
+	*buflen = gai_results->ai_addrlen;
+	memcpy(buf, gai_results->ai_addr, *buflen);
+
+	freeaddrinfo(gai_results);
+
 	return 1;
 }
+
+/**
+ * nfs_callback_address - acquire our local network address
+ * @sap: pointer to address of remote
+ * @sap_len: length of address
+ * @buf: pointer to buffer to be filled in with local network address
+ * @buflen: IN: length of buffer to fill in; OUT: length of filled-in address
+ *
+ * Discover a network address that an NFSv4 server can use to call us back.
+ * On multi-homed clients, this address depends on which NIC we use to
+ * route requests to the server.
+ *
+ * Returns 1 and fills in @buf if an unambiguous local address is
+ * available; returns 1 and fills in an appropriate ANYADDR address
+ * if a local address isn't available; otherwise, returns zero.
+ */
+int nfs_callback_address(const struct sockaddr *sap, const socklen_t salen,
+			 struct sockaddr *buf, socklen_t *buflen)
+{
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
+
+	if (nfs_ca_sockname(sap, salen, buf, buflen) == 0)
+		if (nfs_ca_gai(sap, salen, buf, buflen) == 0)
+			goto out_failed;
+
+	/*
+	 * The server can't use an interface ID that was generated
+	 * here on the client, so always clear sin6_scope_id.
+	 */
+	if (sin6->sin6_family == AF_INET6)
+		sin6->sin6_scope_id = 0;
+
+	return 1;
+
+out_failed:
+	*buflen = 0;
+	if (verbose)
+		nfs_error(_("%s: failed to construct callback address"));
+	return 0;
+
+}