2008-08-05 18:13:43

by Chuck Lever III

[permalink] [raw]
Subject: [PATCH 1/8] nfs-utils: Add AF_INET6-capable API to acquire an RPC CLIENT *

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.

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 <[email protected]>
---

support/include/nfsrpc.h | 64 ++++++
support/nfs/Makefile.am | 2
support/nfs/rpc_socket.c | 467 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 532 insertions(+), 1 deletions(-)
create mode 100644 support/include/nfsrpc.h
create mode 100644 support/nfs/rpc_socket.c

diff --git a/support/include/nfsrpc.h b/support/include/nfsrpc.h
new file mode 100644
index 0000000..f9e187d
--- /dev/null
+++ b/support/include/nfsrpc.h
@@ -0,0 +1,64 @@
+/*
+ * 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[]);
+
+/*
+ * 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..932107f
--- /dev/null
+++ b/support/nfs/rpc_socket.c
@@ -0,0 +1,467 @@
+/*
+ * 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 TIMEOUT_UDP (3)
+#define 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 = 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 = TIMEOUT_TCP;
+
+#ifdef HAVE_CLNT_VC_CREATE
+ memcpy(nbuf.buf, sap, 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)
+ CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+ else
+ 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, sizeof(sin));
+ case AF_INET6:
+ return bind(sock, (struct sockaddr *)&sin6, 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 = 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) {
+ errno = ret;
+ ret = -1;
+ }
+ }
+
+done:
+ 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(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;
+ close(sock);
+ return NULL;
+ }
+
+ if (timeout->tv_sec == -1)
+ timeout->tv_sec = 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;
+ close(sock);
+ return NULL;
+ }
+
+#ifdef HAVE_CLNT_DG_CREATE
+ memcpy(nbuf.buf, sap, 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) {
+ CLNT_CONTROL(client, CLSET_RETRY_TIMEOUT, (char *)timeout);
+ CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+ } else
+ 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(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;
+ close(sock);
+ return NULL;
+ }
+
+ if (timeout->tv_sec == -1)
+ timeout->tv_sec = 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;
+ close(sock);
+ return NULL;
+ }
+
+#ifdef HAVE_CLNT_VC_CREATE
+ memcpy(nbuf.buf, sap, 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)
+ CLNT_CONTROL(client, CLSET_FD_CLOSE, NULL);
+ else
+ 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)
+{
+ switch (sap->sa_family) {
+ case AF_LOCAL:
+ return nfs_get_localclient(sap, salen, program,
+ version, timeout);
+ case AF_INET:
+ case AF_INET6:
+ 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;
+ default:
+ rpc_createerr.cf_stat = RPC_UNKNOWNHOST;
+ 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 entry->r_number;
+ }
+#endif /* HAVE_GETRPCBYNAME */
+
+ return program;
+}