[PATCH 1/2] nfs-utils: Add AF_INET6-capable API to acquire an RPC CLIENT *

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Provide a simple interface that any component of nfs-utils can use to acquire
an RPC CLIENT *.  This is an AF_INET6-enabled API, and can also handle
PF_LOCAL sockets if libtirpc is present on the system.

When libtirpc is not available, legacy RPC services will be used instead,
and an attempt to connect to an AF_INET6 address will fail.

Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---

 configure.ac             |    6 +
 support/include/nfsrpc.h |   70 ++++++
 support/nfs/Makefile.am  |    2 
 support/nfs/rpc_socket.c |  528 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 605 insertions(+), 1 deletions(-)
 create mode 100644 support/include/nfsrpc.h
 create mode 100644 support/nfs/rpc_socket.c

diff --git a/configure.ac b/configure.ac
index 1436d20..48d76d7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -178,6 +178,12 @@ AC_CHECK_FUNC(connect, ,
 AC_CHECK_FUNC(getaddrinfo, , ,
                 AC_MSG_ERROR(Function 'getaddrinfo' not found.))
 
+AC_CHECK_FUNC(getrpcbynumber, , ,
+                AC_MSG_ERROR(Function 'getrpcbynumber' not found.))
+
+AC_CHECK_FUNC(getservbyname, , ,
+                AC_MSG_ERROR(Function 'getservbyname' not found.))
+
 AC_CHECK_LIB(crypt, crypt, [LIBCRYPT="-lcrypt"])
 if test "$enable_nfsv4" = yes; then
     AC_CHECK_LIB(event, event_dispatch, [libevent=1], AC_MSG_ERROR([libevent needed for nfsv4 support]))
diff --git a/support/include/nfsrpc.h b/support/include/nfsrpc.h
new file mode 100644
index 0000000..e129a72
--- /dev/null
+++ b/support/include/nfsrpc.h
@@ -0,0 +1,70 @@
+/*
+ * nfsrpc.h -- RPC client APIs provided by support/nfs
+ *
+ * Copyright (C) 2008 Oracle Corporation.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ */
+
+#ifndef __NFS_UTILS_NFSRPC_H
+#define __NFS_UTILS_NFSRPC_H
+
+#include <rpc/types.h>
+
+/*
+ * Conventional RPC program numbers
+ */
+#ifndef RPCBPROG
+#define RPCBPROG	((rpcprog_t)100000)
+#endif
+#ifndef PMAPPROG
+#define PMAPPROG	((rpcprog_t)100000)
+#endif
+
+#ifndef NFSPROG
+#define NFSPROG		((rpcprog_t)100003)
+#endif
+#ifndef MOUNTPROG
+#define MOUNTPROG	((rpcprog_t)100005)
+#endif
+#ifndef NLMPROG
+#define NLMPROG		((rpcprog_t)100021)
+#endif
+#ifndef NSMPROG
+#define NSMPROG		((rpcprog_t)100024)
+#endif
+
+/*
+ * Look up an RPC program name in /etc/rpc
+ */
+extern rpcprog_t	nfs_getrpcbyname(const rpcprog_t, const char *table[]);
+
+/*
+ * Look up a port number in /etc/services for an RPC program
+ */
+extern unsigned short	nfs_getportbynumber(const rpcprog_t program,
+				const unsigned short transport);
+
+/*
+ * Acquire an RPC CLIENT *
+ */
+extern CLIENT		*nfs_get_rpcclient(const struct sockaddr *,
+				const socklen_t, const unsigned short,
+				const rpcprog_t, const rpcvers_t,
+				struct timeval *);
+
+#endif	/* __NFS_UTILS_NFSRPC_H */
diff --git a/support/nfs/Makefile.am b/support/nfs/Makefile.am
index 87f3949..d6d71d9 100644
--- a/support/nfs/Makefile.am
+++ b/support/nfs/Makefile.am
@@ -3,7 +3,7 @@
 noinst_LIBRARIES = libnfs.a
 libnfs_a_SOURCES = exports.c rmtab.c xio.c rpcmisc.c rpcdispatch.c \
 		   xlog.c xcommon.c wildmat.c nfssvc.c nfsclient.c \
-		   nfsexport.c getfh.c nfsctl.c \
+		   nfsexport.c getfh.c nfsctl.c rpc_socket.c \
 		   svc_socket.c cacheio.c closeall.c nfs_mntent.c
 
 MAINTAINERCLEANFILES = Makefile.in
diff --git a/support/nfs/rpc_socket.c b/support/nfs/rpc_socket.c
new file mode 100644
index 0000000..82ba818
--- /dev/null
+++ b/support/nfs/rpc_socket.c
@@ -0,0 +1,528 @@
+/*
+ * Generic RPC client socket-level APIs for nfs-utils
+ *
+ * Copyright (C) 2008 Oracle Corporation.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <arpa/inet.h>
+
+#include <rpc/rpc.h>
+#include <rpc/pmap_prot.h>
+
+#include "nfsrpc.h"
+
+#ifdef HAVE_TIRPC_NETCONFIG_H
+
+/*
+ * Most of the headers under /usr/include/tirpc are currently
+ * unusable for various reasons.  We statically define the bits
+ * we need here until the official headers are fixed.
+ *
+ * The commonly used RPC calls such as CLNT_CALL and CLNT_DESTROY
+ * are actually virtual functions in both the legacy and TI-RPC
+ * implementations.  The proper _CALL or _DESTROY will be invoked
+ * no matter if we used a legacy clnt_create() or clnt_tli_create()
+ * from libtirpc.
+ */
+
+#include <tirpc/netconfig.h>
+#include <tirpc/rpc/rpcb_prot.h>
+
+/* definitions from tirpc/rpc/types.h */
+
+/*
+ * The netbuf structure is used for transport-independent address storage.
+ */
+struct netbuf {
+	unsigned int	maxlen;
+	unsigned int	len;
+	void		*buf;
+};
+
+/* definitions from tirpc/rpc/clnt.h */
+
+/*
+ * Low level clnt create routine for connectionless transports, e.g. udp.
+ */
+extern CLIENT *clnt_dg_create(const int, const struct netbuf *,
+			      const rpcprog_t, const rpcvers_t,
+			      const u_int, const u_int);
+
+/*
+ * Low level clnt create routine for connectionful transports, e.g. tcp.
+ */
+extern CLIENT *clnt_vc_create(const int, const struct netbuf *,
+			      const rpcprog_t, const rpcvers_t,
+			      u_int, u_int);
+
+#endif	/* HAVE_TIRPC_NETCONFIG_H */
+
+/*
+ * If "-1" is specified in the tv_sec field, use these defaults instead.
+ */
+#define NFSRPC_TIMEOUT_UDP	(3)
+#define NFSRPC_TIMEOUT_TCP	(10)
+
+/*
+ * Set up an RPC client for communicating via a AF_LOCAL socket.
+ *
+ * @timeout is initialized upon return
+ *
+ * Returns a pointer to a prepared RPC client if successful; caller
+ * must destroy a non-NULL returned RPC client.  Otherwise NULL, and
+ * rpc_createerr.cf_stat is set to reflect the error.
+ */
+static CLIENT *nfs_get_localclient(const struct sockaddr *sap,
+				   const socklen_t salen,
+				   const rpcprog_t program,
+				   const rpcvers_t version,
+				   struct timeval *timeout)
+{
+#ifdef HAVE_CLNT_VC_CREATE
+	struct sockaddr_storage address;
+	const struct netbuf nbuf = {
+		.maxlen		= sizeof(struct sockaddr_un),
+		.len		= (size_t)salen,
+		.buf		= &address,
+	};
+#endif	/* HAVE_CLNT_VC_CREATE */
+	CLIENT *client;
+	int sock;
+
+	sock = socket(AF_LOCAL, SOCK_STREAM, 0);
+	if (sock == -1) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		return NULL;
+	}
+
+	if (timeout->tv_sec == -1)
+		timeout->tv_sec = NFSRPC_TIMEOUT_TCP;
+
+#ifdef HAVE_CLNT_VC_CREATE
+	memcpy(nbuf.buf, sap, (size_t)salen);
+	client = clnt_vc_create(sock, &nbuf, program, version, 0, 0);
+#else	/* HAVE_CLNT_VC_CREATE */
+	client = clntunix_create((struct sockaddr_un *)sap,
+					program, version, &sock, 0, 0);
+#endif	/* HAVE_CLNT_VC_CREATE */
+	if (client != NULL)
+		CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+	else
+		(void)close(sock);
+
+	return client;
+}
+
+/*
+ * Bind a socket using an unused ephemeral source port.
+ *
+ * Returns zero on success, or returns -1 on error.  errno is
+ * set to reflect the nature of the error.
+ */
+static int nfs_bind(const int sock, const sa_family_t family)
+{
+	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,
+	};
+
+	switch (family) {
+	case AF_INET:
+		return bind(sock, (struct sockaddr *)&sin,
+					(socklen_t)sizeof(sin));
+	case AF_INET6:
+		return bind(sock, (struct sockaddr *)&sin6,
+					(socklen_t)sizeof(sin6));
+	}
+
+	errno = EAFNOSUPPORT;
+	return -1;
+}
+
+/*
+ * Perform a non-blocking connect on the socket fd.
+ *
+ * @timeout is modified to contain the time remaining (i.e. time provided
+ * minus time elasped).
+ *
+ * Returns zero on success, or returns -1 on error.  errno is
+ * set to reflect the nature of the error.
+ */
+static int nfs_connect_nb(const int fd, const struct sockaddr *sap,
+			  const socklen_t salen, struct timeval *timeout)
+{
+	int flags, ret;
+	fd_set rset;
+
+	flags = fcntl(fd, F_GETFL, 0);
+	if (flags < 0)
+		return -1;
+
+	ret = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+	if (ret < 0)
+		return -1;
+
+	/*
+	 * From here on subsequent sys calls could change errno so
+	 * we set ret = -errno to capture it in case we decide to
+	 * use it later.
+	 */
+	ret = connect(fd, sap, salen);
+	if (ret < 0 && errno != EINPROGRESS) {
+		ret = -1;
+		goto done;
+	}
+
+	if (ret == 0)
+		goto done;
+
+	/* now wait */
+	FD_ZERO(&rset);
+	FD_SET(fd, &rset);
+
+	ret = select(fd + 1, NULL, &rset, NULL, timeout);
+	if (ret <= 0) {
+		if (ret == 0)
+			errno = ETIMEDOUT;
+		ret = -1;
+		goto done;
+	}
+
+	if (FD_ISSET(fd, &rset)) {
+		int status;
+		socklen_t len = (socklen_t)sizeof(ret);
+
+		status = getsockopt(fd, SOL_SOCKET, SO_ERROR, &ret, &len);
+		if (status < 0) {
+			ret = -1;
+			goto done;
+		}
+
+		/* Oops - something wrong with connect */
+		if (ret != 0) {
+			errno = ret;
+			ret = -1;
+		}
+	}
+
+done:
+	(void)fcntl(fd, F_SETFL, flags);
+	return ret;
+}
+
+/*
+ * Set up an RPC client for communicating via a datagram socket.
+ * A connected UDP socket is used to detect a missing remote
+ * listener as quickly as possible.
+ *
+ * @timeout is initialized upon return
+ *
+ * Returns a pointer to a prepared RPC client if successful; caller
+ * must destroy a non-NULL returned RPC client.  Otherwise NULL, and
+ * rpc_createerr.cf_stat is set to reflect the error.
+ */
+static CLIENT *nfs_get_udpclient(const struct sockaddr *sap,
+				 const socklen_t salen,
+				 const rpcprog_t program,
+				 const rpcvers_t version,
+				 struct timeval *timeout)
+{
+#ifdef HAVE_CLNT_DG_CREATE
+	struct sockaddr_storage address;
+	const struct netbuf nbuf = {
+		.maxlen		= salen,
+		.len		= salen,
+		.buf		= &address,
+	};
+#endif	/* HAVE_CLNT_DG_CREATE */
+	CLIENT *client;
+	int ret, sock;
+
+#ifndef HAVE_CLNT_DG_CREATE
+	if (sap->sa_family != AF_INET) {
+		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
+		return NULL;
+	}
+#endif	/* !HAVE_CLNT_DG_CREATE */
+
+	sock = socket((int)sap->sa_family, SOCK_DGRAM, IPPROTO_UDP);
+	if (sock == -1) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		return NULL;
+	}
+
+	ret = nfs_bind(sock, sap->sa_family);
+	if (ret < 0) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		(void)close(sock);
+		return NULL;
+	}
+
+	if (timeout->tv_sec == -1)
+		timeout->tv_sec = NFSRPC_TIMEOUT_UDP;
+
+	ret = nfs_connect_nb(sock, sap, salen, timeout);
+	if (ret != 0) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		(void)close(sock);
+		return NULL;
+	}
+
+#ifdef HAVE_CLNT_DG_CREATE
+	memcpy(nbuf.buf, sap, (size_t)salen);
+	client = clnt_dg_create(sock, &nbuf, program, version, 0, 0);
+#else	/* HAVE_CLNT_DG_CREATE */
+	client = clntudp_create((struct sockaddr_in *)sap, program,
+					version, *timeout, &sock);
+#endif	/* HAVE_CLNT_DG_CREATE */
+	if (client != NULL) {
+		CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *)timeout);
+		CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+	} else
+		(void)close(sock);
+
+	return client;
+}
+
+/*
+ * Set up and connect an RPC client for communicating via a stream socket.
+ *
+ * @timeout is initialized upon return
+ *
+ * Returns a pointer to a prepared and connected RPC client if
+ * successful; caller must destroy a non-NULL returned RPC client.
+ * Otherwise NULL, and rpc_createerr.cf_stat is set to reflect the
+ * error.
+ */
+static CLIENT *nfs_get_tcpclient(const struct sockaddr *sap,
+				 const socklen_t salen,
+				 const rpcprog_t program,
+				 const rpcvers_t version,
+				 struct timeval *timeout)
+{
+#ifdef HAVE_CLNT_VC_CREATE
+	struct sockaddr_storage address;
+	const struct netbuf nbuf = {
+		.maxlen		= salen,
+		.len		= salen,
+		.buf		= &address,
+	};
+#endif	/* HAVE_CLNT_VC_CREATE */
+	CLIENT *client;
+	int ret, sock;
+
+#ifndef HAVE_CLNT_VC_CREATE
+	if (sap->sa_family != AF_INET) {
+		rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
+		return NULL;
+	}
+#endif	/* !HAVE_CLNT_VC_CREATE */
+
+	sock = socket((int)sap->sa_family, SOCK_STREAM, IPPROTO_TCP);
+	if (sock == -1) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		return NULL;
+	}
+
+	ret = nfs_bind(sock, sap->sa_family);
+	if (ret < 0) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		(void)close(sock);
+		return NULL;
+	}
+
+	if (timeout->tv_sec == -1)
+		timeout->tv_sec = NFSRPC_TIMEOUT_TCP;
+
+	ret = nfs_connect_nb(sock, sap, salen, timeout);
+	if (ret != 0) {
+		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
+		rpc_createerr.cf_error.re_errno = errno;
+		(void)close(sock);
+		return NULL;
+	}
+
+#ifdef HAVE_CLNT_VC_CREATE
+	memcpy(nbuf.buf, sap, (size_t)salen);
+	client = clnt_vc_create(sock, &nbuf, program, version, 0, 0);
+#else	/* HAVE_CLNT_VC_CREATE */
+	client = clnttcp_create((struct sockaddr_in *)sap,
+					program, version, &sock, 0, 0);
+#endif	/* HAVE_CLNT_VC_CREATE */
+	if (client != NULL)
+		CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+	else
+		(void)close(sock);
+
+	return client;
+}
+
+/**
+ * nfs_get_rpcclient - acquire an RPC client
+ * @sap: pointer to socket address of RPC server
+ * @salen: length of socket address
+ * @transport: IPPROTO_ value of transport protocol to use
+ * @program: RPC program number
+ * @version: RPC version number
+ * @timeout: pointer to request timeout (must not be NULL)
+ *
+ * Set up an RPC client for communicating with an RPC program @program
+ * and @version on the server @sap over @transport.
+ *
+ * Returns a pointer to a prepared RPC client if successful, and
+ * @timeout is initialized; caller must destroy a non-NULL returned RPC
+ * client.  Otherwise returns NULL, and rpc_createerr.cf_stat is set to
+ * reflect the error.
+ */
+CLIENT *nfs_get_rpcclient(const struct sockaddr *sap,
+			  const socklen_t salen,
+			  const unsigned short transport,
+			  const rpcprog_t program,
+			  const rpcvers_t version,
+			  struct timeval *timeout)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+
+	switch (sap->sa_family) {
+	case AF_LOCAL:
+		return nfs_get_localclient(sap, salen, program,
+						version, timeout);
+	case AF_INET:
+		if (sin->sin_port == 0) {
+			rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
+			return NULL;
+		}
+		break;
+	case AF_INET6:
+		if (sin6->sin6_port == 0) {
+			rpc_createerr.cf_stat = RPC_UNKNOWNADDR;
+			return NULL;
+		}
+		break;
+	default:
+		rpc_createerr.cf_stat = RPC_UNKNOWNHOST;
+		return NULL;
+	}
+
+	switch (transport) {
+	case IPPROTO_TCP:
+		return nfs_get_tcpclient(sap, salen, program, version, timeout);
+	case 0:
+	case IPPROTO_UDP:
+		return nfs_get_udpclient(sap, salen, program, version, timeout);
+	}
+
+	rpc_createerr.cf_stat = RPC_UNKNOWNPROTO;
+	return NULL;
+}
+
+/**
+ * nfs_getrpcbyname - convert an RPC program name to a rpcprog_t
+ * @program: default program number to use if names not found in db
+ * @table: pointer to table of 'char *' names to try to find
+ *
+ * Returns program number of first name to be successfully looked
+ * up, or the default program number if all lookups fail.
+ */
+rpcprog_t nfs_getrpcbyname(const rpcprog_t program, const char *table[])
+{
+#ifdef HAVE_GETRPCBYNAME
+	struct rpcent *entry;
+	unsigned int i;
+
+	if (table != NULL)
+		for (i = 0; table[i] != NULL; i++) {
+			entry = getrpcbyname(table[i]);
+			if (entry)
+				return (rpcprog_t)entry->r_number;
+		}
+#endif	/* HAVE_GETRPCBYNAME */
+
+	return program;
+}
+
+static unsigned short nfs_tryportbyname(const char *name,
+					const char *protocol)
+{
+	struct servent *servp = NULL;
+
+	servp = getservbyname(name, protocol);
+	if (servp != NULL)
+		return (unsigned short)ntohl((uint32_t)servp->s_port);
+	return 0;
+}
+
+/**
+ * nfs_getportbynumber - convert an RPC program number to a port
+ * @program: RPC program number to look up
+ * @transport: IPPROTO_ value of transport protocol to use
+ *
+ * Returns a non-zero port number, in host byte order, on success;
+ * otherwise zero if some problem occurred.
+ */
+unsigned short nfs_getportbynumber(const rpcprog_t program,
+				   const unsigned short transport)
+{
+	char *protocol = (transport == IPPROTO_TCP) ? "tcp" : "udp";
+	struct rpcent *rpcp;
+	unsigned short port = 0;
+
+	rpcp = getrpcbynumber((int)program);
+	if (rpcp == NULL)
+		return port;
+
+	port = nfs_tryportbyname(rpcp->r_name, protocol);
+	if (port != 0)
+		return port;
+
+	if (rpcp->r_aliases) {
+		int i;
+		for (i = 0; rpcp->r_aliases[i] != NULL; i++) {
+			port = nfs_tryportbyname(rpcp->r_aliases[i], protocol);
+			if (port != 0)
+				break;
+		}
+	}
+
+	return port;
+}

--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux