* [PATCH 3/4] SUNRPC: Support for RPC over AF_LOCAL transports
2011-03-22 22:08 [PATCH 0/4] RFC: RPC over AF_LOCAL, kernel client-side Chuck Lever
2011-03-22 22:09 ` [PATCH 1/4] SUNRPC: Clean up use of curly braces in switch cases Chuck Lever
2011-03-22 22:09 ` [PATCH 2/4] SUNRPC: Rename xs_encode_tcp_fragment_header() Chuck Lever
@ 2011-03-22 22:09 ` Chuck Lever
2011-03-22 22:09 ` [PATCH 4/4] SUNRPC: Use AF_LOCAL for rpcbind upcalls Chuck Lever
2011-03-23 15:26 ` [PATCH 0/4] RFC: RPC over AF_LOCAL, kernel client-side Andy Adamson
4 siblings, 0 replies; 8+ messages in thread
From: Chuck Lever @ 2011-03-22 22:09 UTC (permalink / raw)
To: linux-nfs
TI-RPC introduces the capability of performing RPC over AF_LOCAL
sockets. It uses this mainly for registering and unregistering
local RPC services securely with the local rpcbind, but we could
also conceivably use it as a generic upcall mechanism.
This patch provides a client-side only implementation for the moment.
We might also consider a server-side implementation to provide
AF_LOCAL access to NLM (for statd downcalls, and such like).
Autobinding is not supported on kernel AF_LOCAL transports at this
time. Kernel ULPs must specify the pathname of the remote endpoint
when an AF_LOCAL transport is created. rpcbind supports registering
services available via AF_LOCAL, so the kernel could handle it with
some adjustment to ->rpcbind and ->set_port. But we don't need this
feature for doing upcalls via well-known named sockets.
This has not been tested with ULPs that move a substantial amount of
data. Thus, I can't attest to how robust the write_space and
congestion management logic is.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
include/linux/sunrpc/msg_prot.h | 1
include/linux/sunrpc/xprt.h | 3
net/sunrpc/clnt.c | 8 +
net/sunrpc/xprtsock.c | 393 +++++++++++++++++++++++++++++++++++++++
4 files changed, 401 insertions(+), 4 deletions(-)
diff --git a/include/linux/sunrpc/msg_prot.h b/include/linux/sunrpc/msg_prot.h
index 77e6248..c68a147 100644
--- a/include/linux/sunrpc/msg_prot.h
+++ b/include/linux/sunrpc/msg_prot.h
@@ -145,6 +145,7 @@ typedef __be32 rpc_fraghdr;
#define RPCBIND_NETID_TCP "tcp"
#define RPCBIND_NETID_UDP6 "udp6"
#define RPCBIND_NETID_TCP6 "tcp6"
+#define RPCBIND_NETID_LOCAL "local"
/*
* Note that RFC 1833 does not put any size restrictions on the
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index f34da75..5a75b4b 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -141,7 +141,8 @@ enum xprt_transports {
XPRT_TRANSPORT_UDP = IPPROTO_UDP,
XPRT_TRANSPORT_TCP = IPPROTO_TCP,
XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
- XPRT_TRANSPORT_RDMA = 256
+ XPRT_TRANSPORT_RDMA = 256,
+ XPRT_TRANSPORT_LOCAL = 257,
};
struct rpc_xprt {
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 3725c6d..5386148 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -33,7 +33,9 @@
#include <linux/rcupdate.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>
+#include <linux/in.h>
#include <linux/in6.h>
+#include <linux/un.h>
#include <linux/rcupdate.h>
#include <linux/sunrpc/clnt.h>
@@ -305,6 +307,8 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
* up a string representation of the passed-in address.
*/
if (xprtargs.servername == NULL) {
+ struct sockaddr_un *sun =
+ (struct sockaddr_un *)args->address;
struct sockaddr_in *sin =
(struct sockaddr_in *)args->address;
struct sockaddr_in6 *sin6 =
@@ -312,6 +316,10 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
servername[0] = '\0';
switch (args->address->sa_family) {
+ case AF_LOCAL:
+ snprintf(servername, sizeof(servername), "%s",
+ sun->sun_path);
+ break;
case AF_INET:
snprintf(servername, sizeof(servername), "%pI4",
&sin->sin_addr.s_addr);
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index caf397a..98b8506 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -19,6 +19,7 @@
*/
#include <linux/types.h>
+#include <linux/string.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/capability.h>
@@ -28,6 +29,7 @@
#include <linux/in.h>
#include <linux/net.h>
#include <linux/mm.h>
+#include <linux/un.h>
#include <linux/udp.h>
#include <linux/tcp.h>
#include <linux/sunrpc/clnt.h>
@@ -45,6 +47,9 @@
#include <net/tcp.h>
#include "sunrpc.h"
+
+static void xs_close(struct rpc_xprt *xprt);
+
/*
* xprtsock tunables
*/
@@ -261,6 +266,11 @@ static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
return (struct sockaddr *) &xprt->addr;
}
+static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
+{
+ return (struct sockaddr_un *) &xprt->addr;
+}
+
static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
{
return (struct sockaddr_in *) &xprt->addr;
@@ -276,23 +286,34 @@ static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
struct sockaddr *sap = xs_addr(xprt);
struct sockaddr_in6 *sin6;
struct sockaddr_in *sin;
+ struct sockaddr_un *sun;
char buf[128];
- (void)rpc_ntop(sap, buf, sizeof(buf));
- xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
-
switch (sap->sa_family) {
+ case AF_LOCAL:
+ sun = xs_addr_un(xprt);
+ strlcpy(buf, sun->sun_path, sizeof(buf));
+ xprt->address_strings[RPC_DISPLAY_ADDR] =
+ kstrdup(buf, GFP_KERNEL);
+ break;
case AF_INET:
+ (void)rpc_ntop(sap, buf, sizeof(buf));
+ xprt->address_strings[RPC_DISPLAY_ADDR] =
+ kstrdup(buf, GFP_KERNEL);
sin = xs_addr_in(xprt);
snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
break;
case AF_INET6:
+ (void)rpc_ntop(sap, buf, sizeof(buf));
+ xprt->address_strings[RPC_DISPLAY_ADDR] =
+ kstrdup(buf, GFP_KERNEL);
sin6 = xs_addr_in6(xprt);
snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
break;
default:
BUG();
}
+
xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
}
@@ -506,6 +527,58 @@ static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
}
/**
+ * xs_local_send_request - write an RPC request to an AF_LOCAL socket
+ * @task: RPC task that manages the state of an RPC request
+ *
+ * Return values:
+ * 0: The request has been sent
+ * EAGAIN: The socket was blocked, please call again later to
+ * complete the request
+ * ENOTCONN: Caller needs to invoke connect logic then call again
+ * other: Some other error occured, the request was not sent
+ */
+static int xs_local_send_request(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct rpc_xprt *xprt = req->rq_xprt;
+ struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
+ struct xdr_buf *xdr = &req->rq_snd_buf;
+ int status;
+
+ xs_encode_stream_record_marker(&req->rq_snd_buf);
+
+ xs_pktdump("packet data:",
+ req->rq_svec->iov_base, req->rq_svec->iov_len);
+
+ status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent);
+ dprintk("RPC: %s(%u) = %d\n",
+ __func__, xdr->len - req->rq_bytes_sent, status);
+ if (likely(status >= 0)) {
+ req->rq_bytes_sent += status;
+ req->rq_xmit_bytes_sent += status;
+ if (likely(req->rq_bytes_sent >= req->rq_slen)) {
+ req->rq_bytes_sent = 0;
+ return 0;
+ }
+ status = -EAGAIN;
+ }
+
+ switch (status) {
+ case -EAGAIN:
+ status = xs_nospace(task);
+ break;
+ default:
+ dprintk("RPC: sendmsg returned unrecognized error %d\n",
+ -status);
+ case -EPIPE:
+ xs_close(xprt);
+ status = -ENOTCONN;
+ }
+
+ return status;
+}
+
+/**
* xs_udp_send_request - write an RPC request to a UDP socket
* @task: address of RPC task that manages the state of an RPC request
*
@@ -786,6 +859,88 @@ static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
return (struct rpc_xprt *) sk->sk_user_data;
}
+static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
+{
+ struct xdr_skb_reader desc = {
+ .skb = skb,
+ .offset = sizeof(rpc_fraghdr),
+ .count = skb->len - sizeof(rpc_fraghdr),
+ };
+
+ if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
+ return -1;
+ if (desc.count)
+ return -1;
+ return 0;
+}
+
+/**
+ * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
+ * @sk: socket with data to read
+ * @len: how much data to read
+ *
+ * Currently this assumes we can read the whole reply in a single gulp.
+ */
+static void xs_local_data_ready(struct sock *sk, int len)
+{
+ struct rpc_task *task;
+ struct rpc_xprt *xprt;
+ struct rpc_rqst *rovr;
+ struct sk_buff *skb;
+ int err, repsize, copied;
+ u32 _xid;
+ __be32 *xp;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ dprintk("RPC: %s...\n", __func__);
+ xprt = xprt_from_sock(sk);
+ if (xprt == NULL)
+ goto out;
+
+ skb = skb_recv_datagram(sk, 0, 1, &err);
+ if (skb == NULL)
+ goto out;
+
+ if (xprt->shutdown)
+ goto dropit;
+
+ repsize = skb->len - sizeof(rpc_fraghdr);
+ if (repsize < 4) {
+ dprintk("RPC: impossible RPC reply size %d\n", repsize);
+ goto dropit;
+ }
+
+ /* Copy the XID from the skb... */
+ xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
+ if (xp == NULL)
+ goto dropit;
+
+ /* Look up and lock the request corresponding to the given XID */
+ spin_lock(&xprt->transport_lock);
+ rovr = xprt_lookup_rqst(xprt, *xp);
+ if (!rovr)
+ goto out_unlock;
+ task = rovr->rq_task;
+
+ copied = rovr->rq_private_buf.buflen;
+ if (copied > repsize)
+ copied = repsize;
+
+ if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
+ dprintk("RPC: sk_buff copy failed\n");
+ goto out_unlock;
+ }
+
+ xprt_complete_rqst(task, copied);
+
+ out_unlock:
+ spin_unlock(&xprt->transport_lock);
+ dropit:
+ skb_free_datagram(sk, skb);
+ out:
+ read_unlock_bh(&sk->sk_callback_lock);
+}
+
/**
* xs_udp_data_ready - "data ready" callback for UDP sockets
* @sk: socket with data to read
@@ -1572,11 +1727,31 @@ static int xs_bind(struct sock_xprt *transport, struct socket *sock)
return err;
}
+/*
+ * We don't support autobind on AF_LOCAL sockets
+ */
+static void xs_local_rpcbind(struct rpc_task *task)
+{
+ xprt_set_bound(task->tk_xprt);
+}
+
+static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
+{
+}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key xs_key[2];
static struct lock_class_key xs_slock_key[2];
+static inline void xs_reclassify_socketu(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+
+ BUG_ON(sock_owned_by_user(sk));
+ sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
+ &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
+}
+
static inline void xs_reclassify_socket4(struct socket *sock)
{
struct sock *sk = sock->sk;
@@ -1598,6 +1773,9 @@ static inline void xs_reclassify_socket6(struct socket *sock)
static inline void xs_reclassify_socket(int family, struct socket *sock)
{
switch (family) {
+ case AF_LOCAL:
+ xs_reclassify_socketu(sock);
+ break;
case AF_INET:
xs_reclassify_socket4(sock);
break;
@@ -1607,6 +1785,10 @@ static inline void xs_reclassify_socket(int family, struct socket *sock)
}
}
#else
+static inline void xs_reclassify_socketu(struct socket *sock)
+{
+}
+
static inline void xs_reclassify_socket4(struct socket *sock)
{
}
@@ -1645,6 +1827,94 @@ out:
return ERR_PTR(err);
}
+static int xs_local_finish_connecting(struct rpc_xprt *xprt,
+ struct socket *sock)
+{
+ struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
+ xprt);
+
+ if (!transport->inet) {
+ struct sock *sk = sock->sk;
+
+ write_lock_bh(&sk->sk_callback_lock);
+
+ xs_save_old_callbacks(transport, sk);
+
+ sk->sk_user_data = xprt;
+ sk->sk_data_ready = xs_local_data_ready;
+ sk->sk_write_space = xs_udp_write_space;
+ sk->sk_error_report = xs_error_report;
+ sk->sk_allocation = GFP_ATOMIC;
+
+ xprt_clear_connected(xprt);
+
+ /* Reset to new socket */
+ transport->sock = sock;
+ transport->inet = sk;
+
+ write_unlock_bh(&sk->sk_callback_lock);
+ }
+
+ /* Tell the socket layer to start connecting... */
+ xprt->stat.connect_count++;
+ xprt->stat.connect_start = jiffies;
+ return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
+}
+
+/**
+ * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
+ * @xprt: RPC transport to connect
+ * @transport: socket transport to connect
+ * @create_sock: function to create a socket of the correct type
+ *
+ * Invoked by a work queue tasklet.
+ */
+static void xs_local_setup_socket(struct work_struct *work)
+{
+ struct sock_xprt *transport =
+ container_of(work, struct sock_xprt, connect_worker.work);
+ struct rpc_xprt *xprt = &transport->xprt;
+ struct socket *sock;
+ int status = -EIO;
+
+ if (xprt->shutdown)
+ goto out;
+
+ clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
+ status = __sock_create(xprt->xprt_net, AF_LOCAL,
+ SOCK_STREAM, 0, &sock, 1);
+ if (status < 0) {
+ dprintk("RPC: can't create AF_LOCAL "
+ "transport socket (%d).\n", -status);
+ goto out;
+ }
+ xs_reclassify_socketu(sock);
+
+ dprintk("RPC: worker connecting xprt %p via AF_LOCAL to %s\n",
+ xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
+
+ status = xs_local_finish_connecting(xprt, sock);
+ switch (status) {
+ case 0:
+ dprintk("RPC: xprt %p connected to %s\n",
+ xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
+ xprt_set_connected(xprt);
+ break;
+ case -ENOENT:
+ dprintk("RPC: xprt %p: socket %s does not exist\n",
+ xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
+ break;
+ default:
+ printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
+ __func__, -status,
+ xprt->address_strings[RPC_DISPLAY_ADDR]);
+ }
+
+out:
+ xprt_clear_connecting(xprt);
+ xprt_wake_pending_tasks(xprt, status);
+}
+
static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
{
struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
@@ -1918,6 +2188,32 @@ static void xs_connect(struct rpc_task *task)
}
/**
+ * xs_local_print_stats - display AF_LOCAL socket-specifc stats
+ * @xprt: rpc_xprt struct containing statistics
+ * @seq: output file
+ *
+ */
+static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
+{
+ long idle_time = 0;
+
+ if (xprt_connected(xprt))
+ idle_time = (long)(jiffies - xprt->last_used) / HZ;
+
+ seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
+ "%llu %llu\n",
+ xprt->stat.bind_count,
+ xprt->stat.connect_count,
+ xprt->stat.connect_time,
+ idle_time,
+ xprt->stat.sends,
+ xprt->stat.recvs,
+ xprt->stat.bad_xids,
+ xprt->stat.req_u,
+ xprt->stat.bklog_u);
+}
+
+/**
* xs_udp_print_stats - display UDP socket-specifc stats
* @xprt: rpc_xprt struct containing statistics
* @seq: output file
@@ -2087,6 +2383,21 @@ static void bc_destroy(struct rpc_xprt *xprt)
{
}
+static struct rpc_xprt_ops xs_local_ops = {
+ .reserve_xprt = xprt_reserve_xprt,
+ .release_xprt = xs_tcp_release_xprt,
+ .rpcbind = xs_local_rpcbind,
+ .set_port = xs_local_set_port,
+ .connect = xs_connect,
+ .buf_alloc = rpc_malloc,
+ .buf_free = rpc_free,
+ .send_request = xs_local_send_request,
+ .set_retrans_timeout = xprt_set_retrans_timeout_def,
+ .close = xs_close,
+ .destroy = xs_destroy,
+ .print_stats = xs_local_print_stats,
+};
+
static struct rpc_xprt_ops xs_udp_ops = {
.set_buffer_size = xs_udp_set_buffer_size,
.reserve_xprt = xprt_reserve_xprt_cong,
@@ -2148,6 +2459,8 @@ static int xs_init_anyaddr(const int family, struct sockaddr *sap)
};
switch (family) {
+ case AF_LOCAL:
+ break;
case AF_INET:
memcpy(sap, &sin, sizeof(sin));
break;
@@ -2195,6 +2508,70 @@ static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
return xprt;
}
+static const struct rpc_timeout xs_local_default_timeout = {
+ .to_initval = 10 * HZ,
+ .to_maxval = 10 * HZ,
+ .to_retries = 2,
+};
+
+/**
+ * xs_setup_local - Set up transport to use an AF_LOCAL socket
+ * @args: rpc transport creation arguments
+ *
+ * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
+ */
+static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
+{
+ struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
+ struct sock_xprt *transport;
+ struct rpc_xprt *xprt;
+ struct rpc_xprt *ret;
+
+ xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
+ if (IS_ERR(xprt))
+ return xprt;
+ transport = container_of(xprt, struct sock_xprt, xprt);
+
+ xprt->prot = 0;
+ xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
+ xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
+
+ xprt->bind_timeout = XS_BIND_TO;
+ xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
+ xprt->idle_timeout = XS_IDLE_DISC_TO;
+
+ xprt->ops = &xs_local_ops;
+ xprt->timeout = &xs_local_default_timeout;
+
+ switch (sun->sun_family) {
+ case AF_LOCAL:
+ if (sun->sun_path[0] != '/') {
+ dprintk("RPC: bad AF_LOCAL address: %s\n",
+ sun->sun_path);
+ ret = ERR_PTR(-EINVAL);
+ goto out_err;
+ }
+ xprt_set_bound(xprt);
+ INIT_DELAYED_WORK(&transport->connect_worker,
+ xs_local_setup_socket);
+ xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
+ break;
+ default:
+ ret = ERR_PTR(-EAFNOSUPPORT);
+ goto out_err;
+ }
+
+ dprintk("RPC: set up xprt to %s via AF_LOCAL\n",
+ xprt->address_strings[RPC_DISPLAY_ADDR]);
+
+ if (try_module_get(THIS_MODULE))
+ return xprt;
+ ret = ERR_PTR(-EINVAL);
+out_err:
+ xprt_free(xprt);
+ return ret;
+}
+
static const struct rpc_timeout xs_udp_default_timeout = {
.to_initval = 5 * HZ,
.to_maxval = 30 * HZ,
@@ -2436,6 +2813,14 @@ out_err:
return ret;
}
+static struct xprt_class xs_local_transport = {
+ .list = LIST_HEAD_INIT(xs_local_transport.list),
+ .name = "named UNIX socket",
+ .owner = THIS_MODULE,
+ .ident = XPRT_TRANSPORT_LOCAL,
+ .setup = xs_setup_local,
+};
+
static struct xprt_class xs_udp_transport = {
.list = LIST_HEAD_INIT(xs_udp_transport.list),
.name = "udp",
@@ -2471,6 +2856,7 @@ int init_socket_xprt(void)
sunrpc_table_header = register_sysctl_table(sunrpc_table);
#endif
+ xprt_register_transport(&xs_local_transport);
xprt_register_transport(&xs_udp_transport);
xprt_register_transport(&xs_tcp_transport);
xprt_register_transport(&xs_bc_tcp_transport);
@@ -2491,6 +2877,7 @@ void cleanup_socket_xprt(void)
}
#endif
+ xprt_unregister_transport(&xs_local_transport);
xprt_unregister_transport(&xs_udp_transport);
xprt_unregister_transport(&xs_tcp_transport);
xprt_unregister_transport(&xs_bc_tcp_transport);
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 4/4] SUNRPC: Use AF_LOCAL for rpcbind upcalls
2011-03-22 22:08 [PATCH 0/4] RFC: RPC over AF_LOCAL, kernel client-side Chuck Lever
` (2 preceding siblings ...)
2011-03-22 22:09 ` [PATCH 3/4] SUNRPC: Support for RPC over AF_LOCAL transports Chuck Lever
@ 2011-03-22 22:09 ` Chuck Lever
2011-03-23 15:26 ` [PATCH 0/4] RFC: RPC over AF_LOCAL, kernel client-side Andy Adamson
4 siblings, 0 replies; 8+ messages in thread
From: Chuck Lever @ 2011-03-22 22:09 UTC (permalink / raw)
To: linux-nfs
As libtirpc does in user space, have our registration API try using an
AF_LOCAL transport first when registering and unregistering.
This means we don't chew up privileged ports, and our registration is
bound to an "owner" (the effective uid of the process on the sending
end of the transport). Only that "owner" may unregister the service.
The kernel could probe rpcbind via an rpcbind query to determine
whether rpcbind has an AF_LOCAL service. For simplicity, we use the
same technique that libtirpc uses: simply fail over to network
loopback if creating an AF_LOCAL transport to the well-known rpcbind
service socket fails.
This means we open-code the pathname of the rpcbind socket in the
kernel. For now we have to do that anyway because the kernel's
RPC over AF_LOCAL implementation does not support autobind. That may
be undesirable in the long term.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/rpcb_clnt.c | 97 +++++++++++++++++++++++++++++++++++++++++-------
net/sunrpc/svc.c | 2 +
2 files changed, 85 insertions(+), 14 deletions(-)
diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 770e5b6..7654651 100644
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -16,6 +16,7 @@
#include <linux/types.h>
#include <linux/socket.h>
+#include <linux/un.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/kernel.h>
@@ -32,6 +33,8 @@
# define RPCDBG_FACILITY RPCDBG_BIND
#endif
+#define RPCBIND_SOCK_PATHNAME "/var/run/rpcbind.sock"
+
#define RPCBIND_PROGRAM (100000u)
#define RPCBIND_PORT (111u)
@@ -158,20 +161,69 @@ static void rpcb_map_release(void *data)
kfree(map);
}
-static const struct sockaddr_in rpcb_inaddr_loopback = {
- .sin_family = AF_INET,
- .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
- .sin_port = htons(RPCBIND_PORT),
-};
+/*
+ * Returns zero on success, otherwise a negative errno value
+ * is returned.
+ */
+static int rpcb_create_local_unix(void)
+{
+ static const struct sockaddr_un rpcb_localaddr_rpcbind = {
+ .sun_family = AF_LOCAL,
+ .sun_path = RPCBIND_SOCK_PATHNAME,
+ };
+ struct rpc_create_args args = {
+ .net = &init_net,
+ .protocol = XPRT_TRANSPORT_LOCAL,
+ .address = (struct sockaddr *)&rpcb_localaddr_rpcbind,
+ .addrsize = sizeof(rpcb_localaddr_rpcbind),
+ .servername = "localhost",
+ .program = &rpcb_program,
+ .version = RPCBVERS_2,
+ .authflavor = RPC_AUTH_NULL,
+ };
+ struct rpc_clnt *clnt, *clnt4;
+ int result = 0;
+
+ /*
+ * Because we requested an RPC PING at transport creation time,
+ * this works only if the user space portmapper is rpcbind, and
+ * it's listening on AF_LOCAL on the named socket.
+ */
+ clnt = rpc_create(&args);
+ if (IS_ERR(clnt)) {
+ dprintk("RPC: failed to create AF_LOCAL rpcbind "
+ "client (errno %ld).\n", PTR_ERR(clnt));
+ result = -PTR_ERR(clnt);
+ goto out;
+ }
+
+ clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
+ if (IS_ERR(clnt4)) {
+ dprintk("RPC: failed to bind second program to "
+ "rpcbind v4 client (errno %ld).\n",
+ PTR_ERR(clnt4));
+ clnt4 = NULL;
+ }
+
+ /* Protected by rpcb_create_local_mutex */
+ rpcb_local_clnt = clnt;
+ rpcb_local_clnt4 = clnt4;
-static DEFINE_MUTEX(rpcb_create_local_mutex);
+out:
+ return result;
+}
/*
* Returns zero on success, otherwise a negative errno value
* is returned.
*/
-static int rpcb_create_local(void)
+static int rpcb_create_local_net(void)
{
+ static const struct sockaddr_in rpcb_inaddr_loopback = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
+ .sin_port = htons(RPCBIND_PORT),
+ };
struct rpc_create_args args = {
.net = &init_net,
.protocol = XPRT_TRANSPORT_TCP,
@@ -186,13 +238,6 @@ static int rpcb_create_local(void)
struct rpc_clnt *clnt, *clnt4;
int result = 0;
- if (rpcb_local_clnt)
- return result;
-
- mutex_lock(&rpcb_create_local_mutex);
- if (rpcb_local_clnt)
- goto out;
-
clnt = rpc_create(&args);
if (IS_ERR(clnt)) {
dprintk("RPC: failed to create local rpcbind "
@@ -214,10 +259,34 @@ static int rpcb_create_local(void)
clnt4 = NULL;
}
+ /* Protected by rpcb_create_local_mutex */
rpcb_local_clnt = clnt;
rpcb_local_clnt4 = clnt4;
out:
+ return result;
+}
+
+/*
+ * Returns zero on success, otherwise a negative errno value
+ * is returned.
+ */
+static int rpcb_create_local(void)
+{
+ static DEFINE_MUTEX(rpcb_create_local_mutex);
+ int result = 0;
+
+ if (rpcb_local_clnt)
+ return result;
+
+ mutex_lock(&rpcb_create_local_mutex);
+ if (rpcb_local_clnt)
+ goto out;
+
+ if (rpcb_create_local_unix() != 0)
+ result = rpcb_create_local_net();
+
+out:
mutex_unlock(&rpcb_create_local_mutex);
return result;
}
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 08e05a8..2b90292 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -942,6 +942,8 @@ static void svc_unregister(const struct svc_serv *serv)
if (progp->pg_vers[i]->vs_hidden)
continue;
+ dprintk("svc: attempting to unregister %sv%u\n",
+ progp->pg_name, i);
__svc_unregister(progp->pg_prog, i, progp->pg_name);
}
}
^ permalink raw reply related [flat|nested] 8+ messages in thread