patch-2.1.32 linux/net/sunrpc/svcsock.c

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diff -u --recursive --new-file v2.1.31/linux/net/sunrpc/svcsock.c linux/net/sunrpc/svcsock.c
@@ -0,0 +1,967 @@
+/*
+ * linux/net/sunrpc/svcsock.c
+ *
+ * These are the RPC server socket internals.
+ *
+ * The server scheduling algorithm does not always distribute the load
+ * evenly when servicing a single client. May need to modify the
+ * svc_sock_enqueue procedure...
+ *
+ * TCP support is largely untested and may be a little slow. The problem
+ * is that we currently do two separate recvfrom's, one for the 4-byte
+ * record length, and the second for the actual record. This could possibly
+ * be improved by always reading a minimum size of around 100 bytes and
+ * tucking any superfluous bytes away in a temporary store. Still, that
+ * leaves write requests out in the rain. An alternative may be to peek at
+ * the first skb in the queue, and if it matches the next TCP sequence
+ * number, to extract the record marker. Yuck.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/udp.h>
+#include <linux/version.h>
+#include <linux/unistd.h>
+#include <linux/malloc.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#if LINUX_VERSION_CODE >= 0x020100
+#include <asm/uaccess.h>
+#endif
+
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/stats.h>
+
+
+#define RPCDBG_FACILITY	RPCDBG_SVCSOCK
+
+
+static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
+					 int *errp, int pmap_reg);
+static void		svc_udp_data_ready(struct sock *, int);
+static int		svc_udp_recvfrom(struct svc_rqst *);
+static int		svc_udp_sendto(struct svc_rqst *);
+
+
+/*
+ * Queue up an idle server thread.
+ */
+static inline void
+svc_serv_enqueue(struct svc_serv *serv, struct svc_rqst *rqstp)
+{
+	rpc_append_list(&serv->sv_threads, rqstp);
+}
+
+/*
+ * Dequeue an nfsd thread.
+ */
+static inline void
+svc_serv_dequeue(struct svc_serv *serv, struct svc_rqst *rqstp)
+{
+	rpc_remove_list(&serv->sv_threads, rqstp);
+}
+
+/*
+ * Release an skbuff after use
+ */
+static inline void
+svc_release_skb(struct svc_rqst *rqstp)
+{
+	if (!rqstp->rq_skbuff)
+		return;
+
+	dprintk("svc: releasing skb %p\n", rqstp->rq_skbuff);
+	skb_free_datagram(rqstp->rq_sock->sk_sk, rqstp->rq_skbuff);
+	rqstp->rq_skbuff = NULL;
+}
+
+/*
+ * Queue up a socket with data pending. If there are idle nfsd
+ * processes, wake'em up.
+ * When calling this function, you should make sure it can't be interrupted
+ * by the network bottom half.
+ */
+static inline void
+svc_sock_enqueue(struct svc_sock *svsk)
+{
+	struct svc_rqst	*rqstp;
+	struct svc_serv	*serv;
+
+	if (svsk->sk_busy) {
+		/* Don't enqueue socket while daemon is receiving */
+		dprintk("svc: socket %p not enqueued: busy\n", svsk->sk_sk);
+		return;
+	}
+
+	/* Mark socket as busy. It will remain in this state until the
+	 * server has processed all pending data and put the socket back
+	 * on the idle list
+	 */
+	svsk->sk_busy = 1;
+
+	serv = svsk->sk_server;
+	if ((rqstp = serv->sv_threads) != NULL) {
+		dprintk("svc: socket %p served by daemon %p\n",
+						svsk->sk_sk, rqstp);
+		svc_serv_dequeue(serv, rqstp);
+		rqstp->rq_sock = svsk;
+		svsk->sk_inuse++;
+		wake_up(&rqstp->rq_wait);
+	} else {
+		dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
+		rpc_append_list(&serv->sv_sockets, svsk);
+		svsk->sk_qued = 1;
+	}
+}
+
+/*
+ * Dequeue the first socket.
+ */
+static inline struct svc_sock *
+svc_sock_dequeue(struct svc_serv *serv)
+{
+	struct svc_sock	*svsk;
+
+	disable_bh(NET_BH);
+	if ((svsk = serv->sv_sockets) != NULL)
+		rpc_remove_list(&serv->sv_sockets, svsk);
+	enable_bh(NET_BH);
+
+	if (svsk) {
+		dprintk("svc: socket %p dequeued\n", svsk->sk_sk);
+		svsk->sk_qued = 0;
+	}
+
+	return svsk;
+}
+
+/*
+ * Having read count bytes from a socket, check whether it
+ * needs to be re-enqueued.
+ */
+static inline void
+svc_sock_received(struct svc_sock *svsk, int count)
+{
+	disable_bh(NET_BH);
+	if ((svsk->sk_data -= count) < 0) {
+		printk(KERN_NOTICE "svc: sk_data negative!\n");
+		svsk->sk_data = 0;
+	}
+	svsk->sk_rqstp = NULL; /* XXX */
+	svsk->sk_busy = 0;
+	if (svsk->sk_conn || svsk->sk_data || svsk->sk_close) {
+		dprintk("svc: socket %p re-enqueued after receive\n",
+						svsk->sk_sk);
+		svc_sock_enqueue(svsk);
+	}
+	enable_bh(NET_BH);
+}
+
+/*
+ * Dequeue a new connection.
+ */
+static inline void
+svc_sock_accepted(struct svc_sock *svsk)
+{
+	disable_bh(NET_BH);
+        svsk->sk_busy = 0;
+        svsk->sk_conn--;
+        if (svsk->sk_conn || svsk->sk_data || svsk->sk_close) {
+                dprintk("svc: socket %p re-enqueued after accept\n",
+						svsk->sk_sk);
+                svc_sock_enqueue(svsk);
+        }
+	enable_bh(NET_BH);
+}
+
+/*
+ * Release a socket after use.
+ */
+static inline void
+svc_sock_release(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+
+	if (!svsk)
+		return;
+	svc_release_skb(rqstp);
+	rqstp->rq_sock = NULL;
+	if (!--(svsk->sk_inuse) && svsk->sk_dead) {
+		dprintk("svc: releasing dead socket\n");
+		sock_release(svsk->sk_sock);
+		kfree(svsk);
+	}
+}
+
+/*
+ * External function to wake up a server waiting for data
+ */
+void
+svc_wake_up(struct svc_serv *serv)
+{
+	struct svc_rqst	*rqstp;
+
+	if ((rqstp = serv->sv_threads) != NULL) {
+		dprintk("svc: daemon %p woken up.\n", rqstp);
+		/*
+		svc_serv_dequeue(serv, rqstp);
+		rqstp->rq_sock = NULL;
+		 */
+		wake_up(&rqstp->rq_wait);
+	}
+}
+
+/*
+ * Generic sendto routine
+ */
+static int
+svc_sendto(struct svc_rqst *rqstp, struct iovec *iov, int nr)
+{
+	unsigned long	oldfs;
+	struct socket	*sock = rqstp->rq_sock->sk_sock;
+	struct msghdr	msg;
+	int		i, buflen, len;
+
+	for (i = buflen = 0; i < nr; i++)
+		buflen += iov[i].iov_len;
+
+	msg.msg_name    = &rqstp->rq_addr;
+	msg.msg_namelen = sizeof(rqstp->rq_addr);
+	msg.msg_iov     = iov;
+	msg.msg_iovlen  = nr;
+	msg.msg_control = 0;
+
+#if LINUX_VERSION_CODE >= 0x020100
+	msg.msg_flags	= MSG_DONTWAIT;
+
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	len = sock_sendmsg(sock, &msg, buflen);
+	set_fs(oldfs);
+#else
+	msg.msg_flags	= 0;
+
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	len = sock->ops->sendmsg(sock, &msg, buflen, 1, 0);
+	set_fs(oldfs);
+#endif
+
+	dprintk("svc: socket %p sendto([%p %d... ], %d, %d) = %d\n",
+			rqstp->rq_sock,
+			iov[0].iov_base, iov[0].iov_len, nr,
+			buflen, len);
+
+	return len;
+}
+
+/*
+ * Check input queue length
+ */
+static int
+svc_recv_available(struct svc_sock *svsk)
+{
+	unsigned long	oldfs;
+	struct socket	*sock = svsk->sk_sock;
+	int		avail, err;
+
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	err = sock->ops->ioctl(sock, TIOCINQ, (unsigned long) &avail);
+	set_fs(oldfs);
+
+	return (err >= 0)? avail : err;
+}
+
+/*
+ * Generic recvfrom routine.
+ */
+static int
+svc_recvfrom(struct svc_rqst *rqstp, struct iovec *iov, int nr, int buflen)
+{
+	unsigned long	oldfs;
+	struct msghdr	msg;
+	struct socket	*sock;
+	int		len;
+
+	rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
+	sock = rqstp->rq_sock->sk_sock;
+
+	msg.msg_name    = &rqstp->rq_addr;
+	msg.msg_namelen = sizeof(rqstp->rq_addr);
+	msg.msg_iov     = iov;
+	msg.msg_iovlen  = nr;
+	msg.msg_control = 0;
+
+#if LINUX_VERSION_CODE >= 0x020100
+	msg.msg_flags	= MSG_DONTWAIT;
+
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	len = sock_recvmsg(sock, &msg, buflen, MSG_DONTWAIT);
+	set_fs(oldfs);
+#else
+	msg.msg_flags	= 0;
+
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	len = sock->ops->recvmsg(sock, &msg, buflen, 0, 1, &rqstp->rq_addrlen);
+	set_fs(oldfs);
+#endif
+
+	dprintk("svc: socket %p recvfrom(%p, %d) = %d\n", rqstp->rq_sock,
+				iov[0].iov_base, iov[0].iov_len, len);
+
+	return len;
+}
+
+/*
+ * INET callback when data has been received on the socket.
+ */
+static void
+svc_udp_data_ready(struct sock *sk, int count)
+{
+	struct svc_sock	*svsk;
+
+	dprintk("svc: socket %p data ready (inet %p)\n", sk->user_data, sk);
+
+	svsk = (struct svc_sock *)(sk->user_data);
+	if (!svsk)
+		return;
+	svsk->sk_data = 1;
+	svc_sock_enqueue(svsk);
+}
+
+/*
+ * Receive a datagram from a UDP socket.
+ */
+static int
+svc_udp_recvfrom(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+	struct svc_serv	*serv = svsk->sk_server;
+	struct sk_buff	*skb;
+	u32		*data;
+	int		err, len;
+
+	svsk->sk_data = 0;
+	while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
+		svc_sock_received(svsk, 0);
+		if (err == -EAGAIN)
+			return err;
+		/* possibly an icmp error */
+		dprintk("svc: recvfrom returned error %d\n", -err);
+	}
+
+	/* There may be more data */
+	svsk->sk_data = 1;
+
+	len  = skb->len - sizeof(struct udphdr);
+	data = (u32 *) (skb->h.raw + sizeof(struct udphdr));
+
+	rqstp->rq_skbuff      = skb;
+	rqstp->rq_argbuf.base = data;
+	rqstp->rq_argbuf.buf  = data;
+	rqstp->rq_argbuf.len  = (len >> 2);
+	/* rqstp->rq_resbuf      = rqstp->rq_defbuf; */
+	rqstp->rq_prot        = IPPROTO_UDP;
+
+	/* Get sender address */
+	rqstp->rq_addr.sin_family = AF_INET;
+	rqstp->rq_addr.sin_port = skb->h.uh->source;
+#if LINUX_VERSION_CODE >= 0x020100
+	rqstp->rq_addr.sin_addr.s_addr = skb->nh.iph->saddr;
+#else
+	rqstp->rq_addr.sin_addr.s_addr = skb->saddr;
+#endif
+
+	if (serv->sv_stats)
+		serv->sv_stats->netudpcnt++;
+
+	/* One down, maybe more to go... */
+	svsk->sk_sk->stamp = skb->stamp;
+	svc_sock_received(svsk, 0);
+
+	return len;
+}
+
+static int
+svc_udp_sendto(struct svc_rqst *rqstp)
+{
+	struct svc_buf	*bufp = &rqstp->rq_resbuf;
+	int		error;
+
+	/* Set up the first element of the reply iovec.
+	 * Any other iovecs that may be in use have been taken
+	 * care of by the server implementation itself.
+	 */
+	/* bufp->base = bufp->area; */
+	bufp->iov[0].iov_base = bufp->base;
+	bufp->iov[0].iov_len  = bufp->len << 2;
+
+	error = svc_sendto(rqstp, bufp->iov, bufp->nriov);
+	if (error == -ECONNREFUSED)
+		/* ICMP error on earlier request. */
+		error = svc_sendto(rqstp, bufp->iov, bufp->nriov);
+	else if (error == -EAGAIN)
+		/* Ignore and wait for re-xmit */
+		error = 0;
+
+	return error;
+}
+
+static int
+svc_udp_init(struct svc_sock *svsk)
+{
+	svsk->sk_sk->data_ready = svc_udp_data_ready;
+	svsk->sk_recvfrom = svc_udp_recvfrom;
+	svsk->sk_sendto = svc_udp_sendto;
+
+	return 0;
+}
+
+/*
+ * A state change on a listening socket means there's a connection
+ * pending.
+ */
+static void
+svc_tcp_state_change1(struct sock *sk)
+{
+	struct svc_sock	*svsk;
+
+	dprintk("svc: socket %p TCP (listen) state change %d\n",
+			sk, sk->state);
+
+	if  (sk->state != TCP_ESTABLISHED) {
+		/* Aborted connection, SYN_RECV or whatever... */
+		return;
+	}
+	if (!(svsk = (struct svc_sock *) sk->user_data)) {
+		printk("svc: socket %p: no user data\n", sk);
+		return;
+	}
+	svsk->sk_conn++;
+	svc_sock_enqueue(svsk);
+}
+
+/*
+ * A state change on a connected socket means it's dying or dead.
+ */
+static void
+svc_tcp_state_change2(struct sock *sk)
+{
+	struct svc_sock	*svsk;
+
+	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
+			sk, sk->state, sk->user_data);
+
+	if (!(svsk = (struct svc_sock *) sk->user_data)) {
+		printk("svc: socket %p: no user data\n", sk);
+		return;
+	}
+	svsk->sk_close = 1;
+	svc_sock_enqueue(svsk);
+}
+
+static void
+svc_tcp_data_ready(struct sock *sk, int count)
+{
+	struct svc_sock *	svsk;
+
+	/* Disconnect signalled through data_ready?!? */
+	if (sk->state != TCP_ESTABLISHED) {
+		svc_tcp_state_change2(sk);
+		return;
+	}
+
+	dprintk("svc: socket %p TCP data ready (svsk %p)\n",
+			sk, sk->user_data);
+	if (!(svsk = (struct svc_sock *)(sk->user_data)))
+		return;
+	svsk->sk_data++;
+	svc_sock_enqueue(svsk);
+}
+
+/*
+ * Accept a TCP connection
+ */
+static void
+svc_tcp_accept(struct svc_sock *svsk)
+{
+	struct sockaddr_in sin;
+	struct svc_serv	*serv = svsk->sk_server;
+	struct socket	*sock = svsk->sk_sock;
+	struct socket	*newsock;
+	struct proto_ops *ops;
+	struct svc_sock	*newsvsk;
+	int		err, slen;
+
+	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
+	if (!sock)
+		return;
+
+	if (!(newsock = sock_alloc())) {
+		printk(KERN_WARNING "%s: no more sockets!\n", serv->sv_name);
+		return;
+	}
+	dprintk("svc: tcp_accept %p allocated\n", newsock);
+
+	newsock->type = sock->type;
+	if ((err = sock->ops->dup(newsock, sock)) < 0) {
+		printk(KERN_WARNING "%s: socket dup failed (err %d)!\n",
+					serv->sv_name, -err);
+		goto failed;
+	}
+
+	ops = newsock->ops;
+	if ((err = ops->accept(sock, newsock, O_NONBLOCK)) < 0) {
+		printk(KERN_WARNING "%s: accept failed (err %d)!\n",
+					serv->sv_name, -err);
+		goto failed;		/* aborted connection or whatever */
+	}
+
+	slen = sizeof(sin);
+	err = ops->getname(newsock, (struct sockaddr *) &sin, &slen, 1);
+	if (err < 0) {
+		printk(KERN_WARNING "%s: peername failed (err %d)!\n",
+					serv->sv_name, -err);
+		goto failed;		/* aborted connection or whatever */
+	}
+
+	/* Ideally, we would want to reject connections from unauthorized
+	 * hosts here, but we have no generic client tables. For now,
+	 * we just punt connects from unprivileged ports. */
+	if (ntohs(sin.sin_port) >= 1024) {
+		printk(KERN_WARNING
+			"%s: connect from unprivileged port: %08lx:%d",
+			serv->sv_name, 
+			ntohl(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+		goto failed;
+	}
+
+	dprintk("%s: connect from %08lx:%04x\n", serv->sv_name,
+			ntohl(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+
+	if (!(newsvsk = svc_setup_socket(serv, newsock, &err, 0)))
+		goto failed;
+
+	/* Precharge. Data may have arrived on the socket before we
+	 * installed the data_ready callback. 
+	 */
+	newsvsk->sk_data = 1;
+	newsvsk->sk_temp = 1;
+	svc_sock_enqueue(newsvsk);
+
+	if (serv->sv_stats)
+		serv->sv_stats->nettcpconn++;
+
+	return;
+
+failed:
+	sock_release(newsock);
+	return;
+}
+
+/*
+ * Receive data from a TCP socket.
+ */
+static int
+svc_tcp_recvfrom(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+	struct svc_serv	*serv = svsk->sk_server;
+	struct svc_buf	*bufp = &rqstp->rq_argbuf;
+	int		len, ready;
+
+	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
+			svsk, svsk->sk_data, svsk->sk_conn, svsk->sk_close);
+
+	if (svsk->sk_close) {
+		svc_delete_socket(svsk);
+		return 0;
+	}
+
+	if (svsk->sk_conn) {
+		svc_tcp_accept(svsk);
+		svc_sock_accepted(svsk);
+		return 0;
+	}
+
+	ready = svsk->sk_data;
+
+	/* Receive data. If we haven't got the record length yet, get
+	 * the next four bytes. Otherwise try to gobble up as much as
+	 * possible up to the complete record length.
+	 */
+	if (svsk->sk_tcplen < 4) {
+		unsigned long	want = 4 - svsk->sk_tcplen;
+		struct iovec	iov;
+
+		iov.iov_base = ((u32 *) &svsk->sk_reclen) + svsk->sk_tcplen;
+		iov.iov_len  = want;
+		if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
+			goto error;
+		svsk->sk_tcplen += len;
+
+		svsk->sk_reclen = ntohl(svsk->sk_reclen);
+		if (!(svsk->sk_reclen & 0x80000000)) {
+			/* FIXME: shutdown socket */
+			printk(KERN_NOTICE "RPC: bad TCP reclen %08lx",
+					(unsigned long) svsk->sk_reclen);
+			return -EIO;
+		}
+		svsk->sk_reclen &= 0x7fffffff;
+		dprintk("svc: TCP record, %ld bytes\n", svsk->sk_reclen);
+	}
+
+	/* Check whether enough data is available */
+	len = svc_recv_available(svsk);
+	if (len < 0)
+		goto error;
+
+	if (len < svsk->sk_reclen) {
+		dprintk("svc: incomplete TCP record (%d of %ld)\n",
+				len, svsk->sk_reclen);
+		svc_sock_received(svsk, ready);
+		len = -EAGAIN;	/* record not complete */
+	}
+
+	/* Frob argbuf */
+	bufp->iov[0].iov_base += 4;
+	bufp->iov[0].iov_len  -= 4;
+
+	/* Now receive data */
+	len = svc_recvfrom(rqstp, bufp->iov, bufp->nriov, svsk->sk_reclen);
+	if (len < 0)
+		goto error;
+
+	dprintk("svc: TCP complete record (%d bytes)\n", len);
+
+	/* Position reply write pointer immediately after
+	 * record length */
+	rqstp->rq_resbuf.buf += 1;
+	rqstp->rq_resbuf.len  = 1;
+
+	rqstp->rq_skbuff      = 0;
+	rqstp->rq_argbuf.buf += 1;
+	rqstp->rq_argbuf.len  = (len >> 2);
+	rqstp->rq_prot	      = IPPROTO_TCP;
+
+	/* Reset TCP read info */
+	svsk->sk_reclen = 0;
+	svsk->sk_tcplen = 0;
+
+	svc_sock_received(svsk, 1);
+	if (serv->sv_stats)
+		serv->sv_stats->nettcpcnt++;
+
+	return len;
+
+error:
+	if (len == -EAGAIN) {
+		dprintk("RPC: TCP recvfrom got EAGAIN\n");
+		svc_sock_received(svsk, ready); /* Clear data ready */
+	} else {
+		printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
+					svsk->sk_server->sv_name, -len);
+		svc_sock_received(svsk, 0);
+	}
+
+	return len;
+}
+
+/*
+ * Send out data on TCP socket.
+ * FIXME: Make the sendto call non-blocking in order not to hang
+ * a daemon on a a dead client. Requires write queue maintenance.
+ */
+static int
+svc_tcp_sendto(struct svc_rqst *rqstp)
+{
+	struct svc_buf	*bufp = &rqstp->rq_resbuf;
+
+	/* Set up the first element of the reply iovec.
+	 * Any other iovecs that may be in use have been taken
+	 * care of by the server implementation itself.
+	 */
+	bufp->iov[0].iov_base = bufp->base;
+	bufp->iov[0].iov_len  = bufp->len << 2;
+	bufp->base[0] = htonl(0x80000000|((bufp->len << 2) - 4));
+
+	return svc_sendto(rqstp, bufp->iov, bufp->nriov);
+}
+
+static int
+svc_tcp_init(struct svc_sock *svsk)
+{
+	struct sock	*sk = svsk->sk_sk;
+
+	svsk->sk_recvfrom = svc_tcp_recvfrom;
+	svsk->sk_sendto = svc_tcp_sendto;
+
+	if (sk->state == TCP_LISTEN) {
+		dprintk("setting up TCP socket for listening\n");
+		sk->state_change = svc_tcp_state_change1;
+	} else {
+		dprintk("setting up TCP socket for reading\n");
+		sk->state_change = svc_tcp_state_change2;
+		sk->data_ready = svc_tcp_data_ready;
+
+		svsk->sk_reclen = 0;
+		svsk->sk_tcplen = 0;
+	}
+
+	return 0;
+}
+
+/*
+ * Receive the next request on any socket.
+ */
+int
+svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp)
+{
+	struct wait_queue	wait = { current, NULL };
+	struct svc_sock		*svsk;
+	int			len;
+
+	dprintk("svc: server %p waiting for data (to = %ld)\n",
+					rqstp, current->timeout);
+
+again:
+	/* Initialize the buffers */
+	rqstp->rq_argbuf = rqstp->rq_defbuf;
+	rqstp->rq_resbuf = rqstp->rq_defbuf;
+
+	if (signalled())
+		return -EINTR;
+
+	disable_bh(NET_BH);
+	if ((svsk = svc_sock_dequeue(serv)) != NULL) {
+		enable_bh(NET_BH);
+		rqstp->rq_sock = svsk;
+		svsk->sk_inuse++;
+	} else {
+		/* No data pending. Go to sleep */
+		rqstp->rq_sock = NULL;
+		rqstp->rq_wait = NULL;
+		svc_serv_enqueue(serv, rqstp);
+
+		current->state = TASK_INTERRUPTIBLE;
+		add_wait_queue(&rqstp->rq_wait, &wait);
+		enable_bh(NET_BH);
+		schedule();
+
+		if (!(svsk = rqstp->rq_sock)) {
+			svc_serv_dequeue(serv, rqstp);
+			if (!(svsk = rqstp->rq_sock))
+				return signalled()? -EINTR : -EAGAIN;
+		}
+	}
+
+	dprintk("svc: server %p servicing socket %p\n", rqstp, svsk);
+	len = svsk->sk_recvfrom(rqstp);
+
+	/* No data, incomplete (TCP) read, or accept() */
+	if (len == 0 || len == -EAGAIN) {
+		svc_sock_release(rqstp);
+		goto again;
+	}
+
+	rqstp->rq_secure  = ntohs(rqstp->rq_addr.sin_port) < 1024;
+	rqstp->rq_userset = 0;
+	rqstp->rq_verfed  = 0;
+
+	svc_getlong(&rqstp->rq_argbuf, rqstp->rq_xid);
+	svc_putlong(&rqstp->rq_resbuf, rqstp->rq_xid);
+
+	/* Assume that the reply consists of a single buffer. */
+	rqstp->rq_resbuf.nriov = 1;
+
+	if (serv->sv_stats)
+		serv->sv_stats->netcnt++;
+	return len;
+}
+
+/* 
+ * Drop request
+ */
+void
+svc_drop(struct svc_rqst *rqstp)
+{
+	dprintk("svc: socket %p dropped request\n", rqstp->rq_sock);
+	svc_sock_release(rqstp);
+}
+
+/*
+ * Return reply to client.
+ */
+int
+svc_send(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk;
+	int		len;
+
+	if ((svsk = rqstp->rq_sock) == NULL) {
+		printk(KERN_WARNING "NULL socket pointer in %s:%d\n",
+				__FILE__, __LINE__);
+		return -EFAULT;
+	}
+
+	/* release the receive skb before sending the reply */
+	svc_release_skb(rqstp);
+
+	len = svsk->sk_sendto(rqstp);
+	svc_sock_release(rqstp);
+
+	if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
+		return 0;
+	return len;
+}
+
+/*
+ * Initialize socket for RPC use and create svc_sock struct
+ * XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
+ */
+static struct svc_sock *
+svc_setup_socket(struct svc_serv *serv, struct socket *sock,
+					int *errp, int pmap_register)
+{
+	struct svc_sock	*svsk;
+	struct sock	*inet;
+
+	dprintk("svc: svc_setup_socket %p\n", sock);
+	if (!(svsk = kmalloc(sizeof(*svsk), GFP_KERNEL))) {
+		*errp = -ENOMEM;
+		return NULL;
+	}
+	memset(svsk, 0, sizeof(*svsk));
+
+#if LINUX_VERSION_CODE >= 0x020100
+	inet = sock->sk;
+#else
+	inet = (struct sock *) sock->data;
+#endif
+	inet->user_data = svsk;
+	svsk->sk_sock = sock;
+	svsk->sk_sk = inet;
+	svsk->sk_ostate = inet->state_change;
+	svsk->sk_odata = inet->data_ready;
+	svsk->sk_server = serv;
+
+	/* Initialize the socket */
+	if (sock->type == SOCK_DGRAM)
+		*errp = svc_udp_init(svsk);
+	else
+		*errp = svc_tcp_init(svsk);
+if (svsk->sk_sk == NULL)
+	printk(KERN_WARNING "svsk->sk_sk == NULL after svc_prot_init!\n");
+
+	/* Register socket with portmapper */
+	if (*errp >= 0 && pmap_register)
+		*errp = svc_register(serv, inet->protocol,
+					ntohs(inet->dummy_th.source));
+
+	if (*errp < 0) {
+		inet->user_data = NULL;
+		kfree(svsk);
+		return NULL;
+	}
+
+	svsk->sk_list = serv->sv_allsocks;
+	serv->sv_allsocks = svsk;
+
+	dprintk("svc: svc_setup_socket created %p (inet %p)\n",
+				svsk, svsk->sk_sk);
+	return svsk;
+}
+
+/*
+ * Create socket for RPC service.
+ */
+int
+svc_create_socket(struct svc_serv *serv, int protocol, struct sockaddr_in *sin)
+{
+	struct svc_sock	*svsk;
+	struct socket	*sock;
+	int		error;
+	int		type;
+
+	dprintk("svc: svc_create_socket(%s, %d, %08lx:%d)\n",
+				serv->sv_program->pg_name, protocol,
+				ntohl(sin->sin_addr.s_addr),
+				ntohs(sin->sin_port));
+
+	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
+		printk(KERN_WARNING "svc: only UDP and TCP "
+				"sockets supported\n");
+		return -EINVAL;
+	}
+	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
+
+	if ((error = sock_create(AF_INET, type, protocol, &sock)) < 0)
+		return error;
+
+	if (sin != NULL) {
+		error = sock->ops->bind(sock, (struct sockaddr *) sin,
+						sizeof(*sin));
+		if (error < 0)
+			goto bummer;
+	}
+
+	if (protocol == IPPROTO_TCP) {
+		if ((error = sock->ops->listen(sock, 5)) < 0)
+			goto bummer;
+		sock->flags |= SO_ACCEPTCON;
+	}
+
+	if ((svsk = svc_setup_socket(serv, sock, &error, 1)) != NULL)
+		return 0;
+
+bummer:
+	dprintk("svc: svc_create_socket error = %d\n", -error);
+	sock_release(sock);
+	return error;
+}
+
+/*
+ * Remove a dead socket
+ */
+void
+svc_delete_socket(struct svc_sock *svsk)
+{
+	struct svc_sock	**rsk;
+	struct svc_serv	*serv;
+	struct sock	*sk;
+
+	dprintk("svc: svc_delete_socket(%p)\n", svsk);
+
+	serv = svsk->sk_server;
+	sk = svsk->sk_sk;
+
+	sk->state_change = svsk->sk_ostate;
+	sk->data_ready = svsk->sk_odata;
+
+	for (rsk = &serv->sv_allsocks; *rsk; rsk = &(*rsk)->sk_list) {
+		if (*rsk == svsk)
+			break;
+	}
+	if (!*rsk)
+		return;
+	*rsk = svsk->sk_list;
+
+	if (svsk->sk_qued)
+		rpc_remove_list(&serv->sv_sockets, svsk);
+	svsk->sk_dead = 1;
+
+	if (!svsk->sk_inuse) {
+		sock_release(svsk->sk_sock);
+		kfree(svsk);
+	} else {
+		printk(KERN_NOTICE "svc: server socket destroy delayed\n");
+		svsk->sk_server = NULL;
+	}
+}
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