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SUNRPC: Support for RPC over AF_LOCAL transports

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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>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2011-05-09 15:22:44 -04:00 committed by Trond Myklebust
parent 559649efb9
commit 176e21ee2e
4 changed files with 403 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/sunrpc/msg_prot.h
View File

@ -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

3
include/linux/sunrpc/xprt.h
View File

@ -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 {

8
net/sunrpc/clnt.c
View File

@ -28,7 +28,9 @@
#include <linux/slab.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/un.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
@ -294,6 +296,8 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args)
* up a string representation of the passed-in address.
*/
if (args->servername == NULL) {
struct sockaddr_un *sun =
(struct sockaddr_un *)args->address;
struct sockaddr_in *sin =
(struct sockaddr_in *)args->address;
struct sockaddr_in6 *sin6 =
@ -301,6 +305,10 @@ 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);

395
net/sunrpc/xprtsock.c
View File

@ -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);
}
@ -505,6 +526,60 @@ static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
}
/**
* 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
@ -788,6 +863,88 @@ 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
@ -1573,11 +1730,31 @@ 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;
@ -1599,6 +1776,9 @@ 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;
@ -1608,6 +1788,10 @@ 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)
{
}
@ -1646,6 +1830,94 @@ 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);
@ -1929,6 +2201,32 @@ 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
@ -2099,6 +2397,21 @@ 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,
@ -2160,6 +2473,8 @@ 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;
@ -2207,6 +2522,70 @@ 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,
@ -2448,6 +2827,14 @@ 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",
@ -2483,6 +2870,7 @@ 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);
@ -2503,6 +2891,7 @@ 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);