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@xxxxxxxxxx>
---
include/linux/sunrpc/msg_prot.h | 1
include/linux/sunrpc/xprt.h | 3
net/sunrpc/clnt.c | 8 +
net/sunrpc/xprtsock.c | 395 +++++++++++++++++++++++++++++++++++++++
4 files changed, 403 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 a0f998c..81cce3b 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 b91f8f9..c0b03df 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -32,7 +32,9 @@
#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>
@@ -298,6 +300,8 @@ 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 =
@@ -305,6 +309,10 @@ 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 6d54d39..a546eec 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 +527,60 @@ 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
*
@@ -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
@@ -1574,11 +1731,31 @@ 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;
@@ -1600,6 +1777,9 @@ 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;
@@ -1609,6 +1789,10 @@ 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)
{
}
@@ -1647,6 +1831,94 @@ 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);
@@ -1920,6 +2192,32 @@ 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
@@ -2089,6 +2387,21 @@ 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,
@@ -2150,6 +2463,8 @@ 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;
@@ -2197,6 +2512,70 @@ 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,
@@ -2438,6 +2817,14 @@ 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",
@@ -2473,6 +2860,7 @@ 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);
@@ -2493,6 +2881,7 @@ 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);
--
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