Add AF_INET6-capable API to acquire an RPC CLIENT *
authorChuck Lever <chuck.lever@oracle.com>
Mon, 17 Nov 2008 21:08:03 +0000 (16:08 -0500)
committerSteve Dickson <steved@redhat.com>
Mon, 17 Nov 2008 21:08:03 +0000 (16:08 -0500)
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@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>
configure.ac
support/include/nfsrpc.h [new file with mode: 0644]
support/nfs/Makefile.am
support/nfs/rpc_socket.c [new file with mode: 0644]

index 1436d20..48d76d7 100644 (file)
@@ -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 (file)
index 0000000..e129a72
--- /dev/null
@@ -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 */
index 87f3949..d6d71d9 100644 (file)
@@ -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 (file)
index 0000000..82ba818
--- /dev/null
@@ -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;
+}