Initial import

1 files changed, 1672 insertions, 0 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
new file mode 100644
index 000000000..0c8120229
--- /dev/null
+++ b/net/sunrpc/svcsock.c
@@ -0,0 +1,1672 @@
+/*
+ * 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_xprt_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/kernel.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+#include <linux/unistd.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/file.h>
+#include <linux/freezer.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/tcp.h>
+#include <net/tcp_states.h>
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+#include <trace/events/skb.h>
+
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/msg_prot.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/xprt.h>
+
+#include "sunrpc.h"
+
+#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
+
+
+static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
+					 int flags);
+static void		svc_udp_data_ready(struct sock *);
+static int		svc_udp_recvfrom(struct svc_rqst *);
+static int		svc_udp_sendto(struct svc_rqst *);
+static void		svc_sock_detach(struct svc_xprt *);
+static void		svc_tcp_sock_detach(struct svc_xprt *);
+static void		svc_sock_free(struct svc_xprt *);
+
+static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
+					  struct net *, struct sockaddr *,
+					  int, int);
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+static struct svc_xprt *svc_bc_create_socket(struct svc_serv *, int,
+					     struct net *, struct sockaddr *,
+					     int, int);
+static void svc_bc_sock_free(struct svc_xprt *xprt);
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key svc_key[2];
+static struct lock_class_key svc_slock_key[2];
+
+static void svc_reclassify_socket(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	WARN_ON_ONCE(sock_owned_by_user(sk));
+	if (sock_owned_by_user(sk))
+		return;
+
+	switch (sk->sk_family) {
+	case AF_INET:
+		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
+					      &svc_slock_key[0],
+					      "sk_xprt.xpt_lock-AF_INET-NFSD",
+					      &svc_key[0]);
+		break;
+
+	case AF_INET6:
+		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
+					      &svc_slock_key[1],
+					      "sk_xprt.xpt_lock-AF_INET6-NFSD",
+					      &svc_key[1]);
+		break;
+
+	default:
+		BUG();
+	}
+}
+#else
+static void svc_reclassify_socket(struct socket *sock)
+{
+}
+#endif
+
+/*
+ * Release an skbuff after use
+ */
+static void svc_release_skb(struct svc_rqst *rqstp)
+{
+	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
+
+	if (skb) {
+		struct svc_sock *svsk =
+			container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+		rqstp->rq_xprt_ctxt = NULL;
+
+		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
+		skb_free_datagram_locked(svsk->sk_sk, skb);
+	}
+}
+
+union svc_pktinfo_u {
+	struct in_pktinfo pkti;
+	struct in6_pktinfo pkti6;
+};
+#define SVC_PKTINFO_SPACE \
+	CMSG_SPACE(sizeof(union svc_pktinfo_u))
+
+static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
+{
+	struct svc_sock *svsk =
+		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+	switch (svsk->sk_sk->sk_family) {
+	case AF_INET: {
+			struct in_pktinfo *pki = CMSG_DATA(cmh);
+
+			cmh->cmsg_level = SOL_IP;
+			cmh->cmsg_type = IP_PKTINFO;
+			pki->ipi_ifindex = 0;
+			pki->ipi_spec_dst.s_addr =
+				 svc_daddr_in(rqstp)->sin_addr.s_addr;
+			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
+		}
+		break;
+
+	case AF_INET6: {
+			struct in6_pktinfo *pki = CMSG_DATA(cmh);
+			struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
+
+			cmh->cmsg_level = SOL_IPV6;
+			cmh->cmsg_type = IPV6_PKTINFO;
+			pki->ipi6_ifindex = daddr->sin6_scope_id;
+			pki->ipi6_addr = daddr->sin6_addr;
+			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
+		}
+		break;
+	}
+}
+
+/*
+ * send routine intended to be shared by the fore- and back-channel
+ */
+int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
+		    struct page *headpage, unsigned long headoffset,
+		    struct page *tailpage, unsigned long tailoffset)
+{
+	int		result;
+	int		size;
+	struct page	**ppage = xdr->pages;
+	size_t		base = xdr->page_base;
+	unsigned int	pglen = xdr->page_len;
+	unsigned int	flags = MSG_MORE;
+	int		slen;
+	int		len = 0;
+
+	slen = xdr->len;
+
+	/* send head */
+	if (slen == xdr->head[0].iov_len)
+		flags = 0;
+	len = kernel_sendpage(sock, headpage, headoffset,
+				  xdr->head[0].iov_len, flags);
+	if (len != xdr->head[0].iov_len)
+		goto out;
+	slen -= xdr->head[0].iov_len;
+	if (slen == 0)
+		goto out;
+
+	/* send page data */
+	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
+	while (pglen > 0) {
+		if (slen == size)
+			flags = 0;
+		result = kernel_sendpage(sock, *ppage, base, size, flags);
+		if (result > 0)
+			len += result;
+		if (result != size)
+			goto out;
+		slen -= size;
+		pglen -= size;
+		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
+		base = 0;
+		ppage++;
+	}
+
+	/* send tail */
+	if (xdr->tail[0].iov_len) {
+		result = kernel_sendpage(sock, tailpage, tailoffset,
+				   xdr->tail[0].iov_len, 0);
+		if (result > 0)
+			len += result;
+	}
+
+out:
+	return len;
+}
+
+
+/*
+ * Generic sendto routine
+ */
+static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
+{
+	struct svc_sock	*svsk =
+		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+	struct socket	*sock = svsk->sk_sock;
+	union {
+		struct cmsghdr	hdr;
+		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
+	} buffer;
+	struct cmsghdr *cmh = &buffer.hdr;
+	int		len = 0;
+	unsigned long tailoff;
+	unsigned long headoff;
+	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+
+	if (rqstp->rq_prot == IPPROTO_UDP) {
+		struct msghdr msg = {
+			.msg_name	= &rqstp->rq_addr,
+			.msg_namelen	= rqstp->rq_addrlen,
+			.msg_control	= cmh,
+			.msg_controllen	= sizeof(buffer),
+			.msg_flags	= MSG_MORE,
+		};
+
+		svc_set_cmsg_data(rqstp, cmh);
+
+		if (sock_sendmsg(sock, &msg) < 0)
+			goto out;
+	}
+
+	tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
+	headoff = 0;
+	len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
+			       rqstp->rq_respages[0], tailoff);
+
+out:
+	dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
+		svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
+		xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
+
+	return len;
+}
+
+/*
+ * Report socket names for nfsdfs
+ */
+static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
+{
+	const struct sock *sk = svsk->sk_sk;
+	const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
+							"udp" : "tcp";
+	int len;
+
+	switch (sk->sk_family) {
+	case PF_INET:
+		len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
+				proto_name,
+				&inet_sk(sk)->inet_rcv_saddr,
+				inet_sk(sk)->inet_num);
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case PF_INET6:
+		len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
+				proto_name,
+				&sk->sk_v6_rcv_saddr,
+				inet_sk(sk)->inet_num);
+		break;
+#endif
+	default:
+		len = snprintf(buf, remaining, "*unknown-%d*\n",
+				sk->sk_family);
+	}
+
+	if (len >= remaining) {
+		*buf = '\0';
+		return -ENAMETOOLONG;
+	}
+	return len;
+}
+
+/*
+ * Generic recvfrom routine.
+ */
+static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
+			int buflen)
+{
+	struct svc_sock *svsk =
+		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+	struct msghdr msg = {
+		.msg_flags	= MSG_DONTWAIT,
+	};
+	int len;
+
+	rqstp->rq_xprt_hlen = 0;
+
+	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+	len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
+				msg.msg_flags);
+	/* If we read a full record, then assume there may be more
+	 * data to read (stream based sockets only!)
+	 */
+	if (len == buflen)
+		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+
+	dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
+		svsk, iov[0].iov_base, iov[0].iov_len, len);
+	return len;
+}
+
+static int svc_partial_recvfrom(struct svc_rqst *rqstp,
+				struct kvec *iov, int nr,
+				int buflen, unsigned int base)
+{
+	size_t save_iovlen;
+	void *save_iovbase;
+	unsigned int i;
+	int ret;
+
+	if (base == 0)
+		return svc_recvfrom(rqstp, iov, nr, buflen);
+
+	for (i = 0; i < nr; i++) {
+		if (iov[i].iov_len > base)
+			break;
+		base -= iov[i].iov_len;
+	}
+	save_iovlen = iov[i].iov_len;
+	save_iovbase = iov[i].iov_base;
+	iov[i].iov_len -= base;
+	iov[i].iov_base += base;
+	ret = svc_recvfrom(rqstp, &iov[i], nr - i, buflen);
+	iov[i].iov_len = save_iovlen;
+	iov[i].iov_base = save_iovbase;
+	return ret;
+}
+
+/*
+ * Set socket snd and rcv buffer lengths
+ */
+static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
+				unsigned int rcv)
+{
+#if 0
+	mm_segment_t	oldfs;
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
+			(char*)&snd, sizeof(snd));
+	sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+			(char*)&rcv, sizeof(rcv));
+#else
+	/* sock_setsockopt limits use to sysctl_?mem_max,
+	 * which isn't acceptable.  Until that is made conditional
+	 * on not having CAP_SYS_RESOURCE or similar, we go direct...
+	 * DaveM said I could!
+	 */
+	lock_sock(sock->sk);
+	sock->sk->sk_sndbuf = snd * 2;
+	sock->sk->sk_rcvbuf = rcv * 2;
+	sock->sk->sk_write_space(sock->sk);
+	release_sock(sock->sk);
+#endif
+}
+
+static int svc_sock_secure_port(struct svc_rqst *rqstp)
+{
+	return svc_port_is_privileged(svc_addr(rqstp));
+}
+
+/*
+ * INET callback when data has been received on the socket.
+ */
+static void svc_udp_data_ready(struct sock *sk)
+{
+	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
+	wait_queue_head_t *wq = sk_sleep(sk);
+
+	if (svsk) {
+		dprintk("svc: socket %p(inet %p), busy=%d\n",
+			svsk, sk,
+			test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
+		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+		svc_xprt_enqueue(&svsk->sk_xprt);
+	}
+	if (wq && waitqueue_active(wq))
+		wake_up_interruptible(wq);
+}
+
+/*
+ * INET callback when space is newly available on the socket.
+ */
+static void svc_write_space(struct sock *sk)
+{
+	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
+	wait_queue_head_t *wq = sk_sleep(sk);
+
+	if (svsk) {
+		dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
+			svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
+		svc_xprt_enqueue(&svsk->sk_xprt);
+	}
+
+	if (wq && waitqueue_active(wq)) {
+		dprintk("RPC svc_write_space: someone sleeping on %p\n",
+		       svsk);
+		wake_up_interruptible(wq);
+	}
+}
+
+static int svc_tcp_has_wspace(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk =	container_of(xprt, struct svc_sock, sk_xprt);
+	struct svc_serv *serv = svsk->sk_xprt.xpt_server;
+	int required;
+
+	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
+		return 1;
+	required = atomic_read(&xprt->xpt_reserved) + serv->sv_max_mesg;
+	if (sk_stream_wspace(svsk->sk_sk) >= required ||
+	    (sk_stream_min_wspace(svsk->sk_sk) == 0 &&
+	     atomic_read(&xprt->xpt_reserved) == 0))
+		return 1;
+	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+	return 0;
+}
+
+static void svc_tcp_write_space(struct sock *sk)
+{
+	struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
+	struct socket *sock = sk->sk_socket;
+
+	if (!sk_stream_is_writeable(sk) || !sock)
+		return;
+	if (!svsk || svc_tcp_has_wspace(&svsk->sk_xprt))
+		clear_bit(SOCK_NOSPACE, &sock->flags);
+	svc_write_space(sk);
+}
+
+static void svc_tcp_adjust_wspace(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+
+	if (svc_tcp_has_wspace(xprt))
+		clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+}
+
+/*
+ * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
+ */
+static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
+				     struct cmsghdr *cmh)
+{
+	struct in_pktinfo *pki = CMSG_DATA(cmh);
+	struct sockaddr_in *daddr = svc_daddr_in(rqstp);
+
+	if (cmh->cmsg_type != IP_PKTINFO)
+		return 0;
+
+	daddr->sin_family = AF_INET;
+	daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
+	return 1;
+}
+
+/*
+ * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
+ */
+static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
+				     struct cmsghdr *cmh)
+{
+	struct in6_pktinfo *pki = CMSG_DATA(cmh);
+	struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
+
+	if (cmh->cmsg_type != IPV6_PKTINFO)
+		return 0;
+
+	daddr->sin6_family = AF_INET6;
+	daddr->sin6_addr = pki->ipi6_addr;
+	daddr->sin6_scope_id = pki->ipi6_ifindex;
+	return 1;
+}
+
+/*
+ * Copy the UDP datagram's destination address to the rqstp structure.
+ * The 'destination' address in this case is the address to which the
+ * peer sent the datagram, i.e. our local address. For multihomed
+ * hosts, this can change from msg to msg. Note that only the IP
+ * address changes, the port number should remain the same.
+ */
+static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
+				    struct cmsghdr *cmh)
+{
+	switch (cmh->cmsg_level) {
+	case SOL_IP:
+		return svc_udp_get_dest_address4(rqstp, cmh);
+	case SOL_IPV6:
+		return svc_udp_get_dest_address6(rqstp, cmh);
+	}
+
+	return 0;
+}
+
+/*
+ * Receive a datagram from a UDP socket.
+ */
+static int svc_udp_recvfrom(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk =
+		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
+	struct sk_buff	*skb;
+	union {
+		struct cmsghdr	hdr;
+		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
+	} buffer;
+	struct cmsghdr *cmh = &buffer.hdr;
+	struct msghdr msg = {
+		.msg_name = svc_addr(rqstp),
+		.msg_control = cmh,
+		.msg_controllen = sizeof(buffer),
+		.msg_flags = MSG_DONTWAIT,
+	};
+	size_t len;
+	int err;
+
+	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
+	    /* udp sockets need large rcvbuf as all pending
+	     * requests are still in that buffer.  sndbuf must
+	     * also be large enough that there is enough space
+	     * for one reply per thread.  We count all threads
+	     * rather than threads in a particular pool, which
+	     * provides an upper bound on the number of threads
+	     * which will access the socket.
+	     */
+	    svc_sock_setbufsize(svsk->sk_sock,
+				(serv->sv_nrthreads+3) * serv->sv_max_mesg,
+				(serv->sv_nrthreads+3) * serv->sv_max_mesg);
+
+	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+	skb = NULL;
+	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
+			     0, 0, MSG_PEEK | MSG_DONTWAIT);
+	if (err >= 0)
+		skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err);
+
+	if (skb == NULL) {
+		if (err != -EAGAIN) {
+			/* possibly an icmp error */
+			dprintk("svc: recvfrom returned error %d\n", -err);
+			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+		}
+		return 0;
+	}
+	len = svc_addr_len(svc_addr(rqstp));
+	rqstp->rq_addrlen = len;
+	if (skb->tstamp.tv64 == 0) {
+		skb->tstamp = ktime_get_real();
+		/* Don't enable netstamp, sunrpc doesn't
+		   need that much accuracy */
+	}
+	svsk->sk_sk->sk_stamp = skb->tstamp;
+	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
+
+	len  = skb->len - sizeof(struct udphdr);
+	rqstp->rq_arg.len = len;
+
+	rqstp->rq_prot = IPPROTO_UDP;
+
+	if (!svc_udp_get_dest_address(rqstp, cmh)) {
+		net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
+				     cmh->cmsg_level, cmh->cmsg_type);
+		goto out_free;
+	}
+	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
+
+	if (skb_is_nonlinear(skb)) {
+		/* we have to copy */
+		local_bh_disable();
+		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
+			local_bh_enable();
+			/* checksum error */
+			goto out_free;
+		}
+		local_bh_enable();
+		skb_free_datagram_locked(svsk->sk_sk, skb);
+	} else {
+		/* we can use it in-place */
+		rqstp->rq_arg.head[0].iov_base = skb->data +
+			sizeof(struct udphdr);
+		rqstp->rq_arg.head[0].iov_len = len;
+		if (skb_checksum_complete(skb))
+			goto out_free;
+		rqstp->rq_xprt_ctxt = skb;
+	}
+
+	rqstp->rq_arg.page_base = 0;
+	if (len <= rqstp->rq_arg.head[0].iov_len) {
+		rqstp->rq_arg.head[0].iov_len = len;
+		rqstp->rq_arg.page_len = 0;
+		rqstp->rq_respages = rqstp->rq_pages+1;
+	} else {
+		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
+		rqstp->rq_respages = rqstp->rq_pages + 1 +
+			DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
+	}
+	rqstp->rq_next_page = rqstp->rq_respages+1;
+
+	if (serv->sv_stats)
+		serv->sv_stats->netudpcnt++;
+
+	return len;
+out_free:
+	trace_kfree_skb(skb, svc_udp_recvfrom);
+	skb_free_datagram_locked(svsk->sk_sk, skb);
+	return 0;
+}
+
+static int
+svc_udp_sendto(struct svc_rqst *rqstp)
+{
+	int		error;
+
+	error = svc_sendto(rqstp, &rqstp->rq_res);
+	if (error == -ECONNREFUSED)
+		/* ICMP error on earlier request. */
+		error = svc_sendto(rqstp, &rqstp->rq_res);
+
+	return error;
+}
+
+static void svc_udp_prep_reply_hdr(struct svc_rqst *rqstp)
+{
+}
+
+static int svc_udp_has_wspace(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct svc_serv	*serv = xprt->xpt_server;
+	unsigned long required;
+
+	/*
+	 * Set the SOCK_NOSPACE flag before checking the available
+	 * sock space.
+	 */
+	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
+	if (required*2 > sock_wspace(svsk->sk_sk))
+		return 0;
+	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+	return 1;
+}
+
+static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
+{
+	BUG();
+	return NULL;
+}
+
+static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
+				       struct net *net,
+				       struct sockaddr *sa, int salen,
+				       int flags)
+{
+	return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
+}
+
+static struct svc_xprt_ops svc_udp_ops = {
+	.xpo_create = svc_udp_create,
+	.xpo_recvfrom = svc_udp_recvfrom,
+	.xpo_sendto = svc_udp_sendto,
+	.xpo_release_rqst = svc_release_skb,
+	.xpo_detach = svc_sock_detach,
+	.xpo_free = svc_sock_free,
+	.xpo_prep_reply_hdr = svc_udp_prep_reply_hdr,
+	.xpo_has_wspace = svc_udp_has_wspace,
+	.xpo_accept = svc_udp_accept,
+	.xpo_secure_port = svc_sock_secure_port,
+};
+
+static struct svc_xprt_class svc_udp_class = {
+	.xcl_name = "udp",
+	.xcl_owner = THIS_MODULE,
+	.xcl_ops = &svc_udp_ops,
+	.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
+	.xcl_ident = XPRT_TRANSPORT_UDP,
+};
+
+static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
+{
+	int err, level, optname, one = 1;
+
+	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class,
+		      &svsk->sk_xprt, serv);
+	clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
+	svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
+	svsk->sk_sk->sk_write_space = svc_write_space;
+
+	/* initialise setting must have enough space to
+	 * receive and respond to one request.
+	 * svc_udp_recvfrom will re-adjust if necessary
+	 */
+	svc_sock_setbufsize(svsk->sk_sock,
+			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
+			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
+
+	/* data might have come in before data_ready set up */
+	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+	set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
+
+	/* make sure we get destination address info */
+	switch (svsk->sk_sk->sk_family) {
+	case AF_INET:
+		level = SOL_IP;
+		optname = IP_PKTINFO;
+		break;
+	case AF_INET6:
+		level = SOL_IPV6;
+		optname = IPV6_RECVPKTINFO;
+		break;
+	default:
+		BUG();
+	}
+	err = kernel_setsockopt(svsk->sk_sock, level, optname,
+					(char *)&one, sizeof(one));
+	dprintk("svc: kernel_setsockopt returned %d\n", err);
+}
+
+/*
+ * A data_ready event on a listening socket means there's a connection
+ * pending. Do not use state_change as a substitute for it.
+ */
+static void svc_tcp_listen_data_ready(struct sock *sk)
+{
+	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
+	wait_queue_head_t *wq;
+
+	dprintk("svc: socket %p TCP (listen) state change %d\n",
+		sk, sk->sk_state);
+
+	/*
+	 * This callback may called twice when a new connection
+	 * is established as a child socket inherits everything
+	 * from a parent LISTEN socket.
+	 * 1) data_ready method of the parent socket will be called
+	 *    when one of child sockets become ESTABLISHED.
+	 * 2) data_ready method of the child socket may be called
+	 *    when it receives data before the socket is accepted.
+	 * In case of 2, we should ignore it silently.
+	 */
+	if (sk->sk_state == TCP_LISTEN) {
+		if (svsk) {
+			set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
+			svc_xprt_enqueue(&svsk->sk_xprt);
+		} else
+			printk("svc: socket %p: no user data\n", sk);
+	}
+
+	wq = sk_sleep(sk);
+	if (wq && waitqueue_active(wq))
+		wake_up_interruptible_all(wq);
+}
+
+/*
+ * A state change on a connected socket means it's dying or dead.
+ */
+static void svc_tcp_state_change(struct sock *sk)
+{
+	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
+	wait_queue_head_t *wq = sk_sleep(sk);
+
+	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
+		sk, sk->sk_state, sk->sk_user_data);
+
+	if (!svsk)
+		printk("svc: socket %p: no user data\n", sk);
+	else {
+		set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+		svc_xprt_enqueue(&svsk->sk_xprt);
+	}
+	if (wq && waitqueue_active(wq))
+		wake_up_interruptible_all(wq);
+}
+
+static void svc_tcp_data_ready(struct sock *sk)
+{
+	struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
+	wait_queue_head_t *wq = sk_sleep(sk);
+
+	dprintk("svc: socket %p TCP data ready (svsk %p)\n",
+		sk, sk->sk_user_data);
+	if (svsk) {
+		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+		svc_xprt_enqueue(&svsk->sk_xprt);
+	}
+	if (wq && waitqueue_active(wq))
+		wake_up_interruptible(wq);
+}
+
+/*
+ * Accept a TCP connection
+ */
+static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct sockaddr_storage addr;
+	struct sockaddr	*sin = (struct sockaddr *) &addr;
+	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
+	struct socket	*sock = svsk->sk_sock;
+	struct socket	*newsock;
+	struct svc_sock	*newsvsk;
+	int		err, slen;
+	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+
+	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
+	if (!sock)
+		return NULL;
+
+	clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
+	err = kernel_accept(sock, &newsock, O_NONBLOCK);
+	if (err < 0) {
+		if (err == -ENOMEM)
+			printk(KERN_WARNING "%s: no more sockets!\n",
+			       serv->sv_name);
+		else if (err != -EAGAIN)
+			net_warn_ratelimited("%s: accept failed (err %d)!\n",
+					     serv->sv_name, -err);
+		return NULL;
+	}
+	set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
+
+	err = kernel_getpeername(newsock, sin, &slen);
+	if (err < 0) {
+		net_warn_ratelimited("%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 when we get encryption, the IP of the host won't
+	 * tell us anything.  For now just warn about unpriv connections.
+	 */
+	if (!svc_port_is_privileged(sin)) {
+		dprintk("%s: connect from unprivileged port: %s\n",
+			serv->sv_name,
+			__svc_print_addr(sin, buf, sizeof(buf)));
+	}
+	dprintk("%s: connect from %s\n", serv->sv_name,
+		__svc_print_addr(sin, buf, sizeof(buf)));
+
+	/* make sure that a write doesn't block forever when
+	 * low on memory
+	 */
+	newsock->sk->sk_sndtimeo = HZ*30;
+
+	newsvsk = svc_setup_socket(serv, newsock,
+				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
+	if (IS_ERR(newsvsk))
+		goto failed;
+	svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
+	err = kernel_getsockname(newsock, sin, &slen);
+	if (unlikely(err < 0)) {
+		dprintk("svc_tcp_accept: kernel_getsockname error %d\n", -err);
+		slen = offsetof(struct sockaddr, sa_data);
+	}
+	svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
+
+	if (sock_is_loopback(newsock->sk))
+		set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
+	else
+		clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
+	if (serv->sv_stats)
+		serv->sv_stats->nettcpconn++;
+
+	return &newsvsk->sk_xprt;
+
+failed:
+	sock_release(newsock);
+	return NULL;
+}
+
+static unsigned int svc_tcp_restore_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
+{
+	unsigned int i, len, npages;
+
+	if (svsk->sk_datalen == 0)
+		return 0;
+	len = svsk->sk_datalen;
+	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	for (i = 0; i < npages; i++) {
+		if (rqstp->rq_pages[i] != NULL)
+			put_page(rqstp->rq_pages[i]);
+		BUG_ON(svsk->sk_pages[i] == NULL);
+		rqstp->rq_pages[i] = svsk->sk_pages[i];
+		svsk->sk_pages[i] = NULL;
+	}
+	rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
+	return len;
+}
+
+static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
+{
+	unsigned int i, len, npages;
+
+	if (svsk->sk_datalen == 0)
+		return;
+	len = svsk->sk_datalen;
+	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	for (i = 0; i < npages; i++) {
+		svsk->sk_pages[i] = rqstp->rq_pages[i];
+		rqstp->rq_pages[i] = NULL;
+	}
+}
+
+static void svc_tcp_clear_pages(struct svc_sock *svsk)
+{
+	unsigned int i, len, npages;
+
+	if (svsk->sk_datalen == 0)
+		goto out;
+	len = svsk->sk_datalen;
+	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	for (i = 0; i < npages; i++) {
+		if (svsk->sk_pages[i] == NULL) {
+			WARN_ON_ONCE(1);
+			continue;
+		}
+		put_page(svsk->sk_pages[i]);
+		svsk->sk_pages[i] = NULL;
+	}
+out:
+	svsk->sk_tcplen = 0;
+	svsk->sk_datalen = 0;
+}
+
+/*
+ * Receive fragment record header.
+ * If we haven't gotten the record length yet, get the next four bytes.
+ */
+static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
+{
+	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
+	unsigned int want;
+	int len;
+
+	if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
+		struct kvec	iov;
+
+		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
+		iov.iov_base = ((char *) &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;
+
+		if (len < want) {
+			dprintk("svc: short recvfrom while reading record "
+				"length (%d of %d)\n", len, want);
+			return -EAGAIN;
+		}
+
+		dprintk("svc: TCP record, %d bytes\n", svc_sock_reclen(svsk));
+		if (svc_sock_reclen(svsk) + svsk->sk_datalen >
+							serv->sv_max_mesg) {
+			net_notice_ratelimited("RPC: fragment too large: %d\n",
+					svc_sock_reclen(svsk));
+			goto err_delete;
+		}
+	}
+
+	return svc_sock_reclen(svsk);
+error:
+	dprintk("RPC: TCP recv_record got %d\n", len);
+	return len;
+err_delete:
+	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+	return -EAGAIN;
+}
+
+static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
+{
+	struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
+	struct rpc_rqst *req = NULL;
+	struct kvec *src, *dst;
+	__be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
+	__be32 xid;
+	__be32 calldir;
+
+	xid = *p++;
+	calldir = *p;
+
+	if (!bc_xprt)
+		return -EAGAIN;
+	spin_lock_bh(&bc_xprt->transport_lock);
+	req = xprt_lookup_rqst(bc_xprt, xid);
+	if (!req)
+		goto unlock_notfound;
+
+	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
+	/*
+	 * XXX!: cheating for now!  Only copying HEAD.
+	 * But we know this is good enough for now (in fact, for any
+	 * callback reply in the forseeable future).
+	 */
+	dst = &req->rq_private_buf.head[0];
+	src = &rqstp->rq_arg.head[0];
+	if (dst->iov_len < src->iov_len)
+		goto unlock_eagain; /* whatever; just giving up. */
+	memcpy(dst->iov_base, src->iov_base, src->iov_len);
+	xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
+	rqstp->rq_arg.len = 0;
+	spin_unlock_bh(&bc_xprt->transport_lock);
+	return 0;
+unlock_notfound:
+	printk(KERN_NOTICE
+		"%s: Got unrecognized reply: "
+		"calldir 0x%x xpt_bc_xprt %p xid %08x\n",
+		__func__, ntohl(calldir),
+		bc_xprt, ntohl(xid));
+unlock_eagain:
+	spin_unlock_bh(&bc_xprt->transport_lock);
+	return -EAGAIN;
+}
+
+static int copy_pages_to_kvecs(struct kvec *vec, struct page **pages, int len)
+{
+	int i = 0;
+	int t = 0;
+
+	while (t < len) {
+		vec[i].iov_base = page_address(pages[i]);
+		vec[i].iov_len = PAGE_SIZE;
+		i++;
+		t += PAGE_SIZE;
+	}
+	return i;
+}
+
+static void svc_tcp_fragment_received(struct svc_sock *svsk)
+{
+	/* If we have more data, signal svc_xprt_enqueue() to try again */
+	dprintk("svc: TCP %s record (%d bytes)\n",
+		svc_sock_final_rec(svsk) ? "final" : "nonfinal",
+		svc_sock_reclen(svsk));
+	svsk->sk_tcplen = 0;
+	svsk->sk_reclen = 0;
+}
+
+/*
+ * Receive data from a TCP socket.
+ */
+static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk =
+		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
+	int		len;
+	struct kvec *vec;
+	unsigned int want, base;
+	__be32 *p;
+	__be32 calldir;
+	int pnum;
+
+	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
+		svsk, test_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags),
+		test_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags),
+		test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
+
+	len = svc_tcp_recv_record(svsk, rqstp);
+	if (len < 0)
+		goto error;
+
+	base = svc_tcp_restore_pages(svsk, rqstp);
+	want = svc_sock_reclen(svsk) - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
+
+	vec = rqstp->rq_vec;
+
+	pnum = copy_pages_to_kvecs(&vec[0], &rqstp->rq_pages[0],
+						svsk->sk_datalen + want);
+
+	rqstp->rq_respages = &rqstp->rq_pages[pnum];
+	rqstp->rq_next_page = rqstp->rq_respages + 1;
+
+	/* Now receive data */
+	len = svc_partial_recvfrom(rqstp, vec, pnum, want, base);
+	if (len >= 0) {
+		svsk->sk_tcplen += len;
+		svsk->sk_datalen += len;
+	}
+	if (len != want || !svc_sock_final_rec(svsk)) {
+		svc_tcp_save_pages(svsk, rqstp);
+		if (len < 0 && len != -EAGAIN)
+			goto err_delete;
+		if (len == want)
+			svc_tcp_fragment_received(svsk);
+		else
+			dprintk("svc: incomplete TCP record (%d of %d)\n",
+				(int)(svsk->sk_tcplen - sizeof(rpc_fraghdr)),
+				svc_sock_reclen(svsk));
+		goto err_noclose;
+	}
+
+	if (svsk->sk_datalen < 8) {
+		svsk->sk_datalen = 0;
+		goto err_delete; /* client is nuts. */
+	}
+
+	rqstp->rq_arg.len = svsk->sk_datalen;
+	rqstp->rq_arg.page_base = 0;
+	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
+		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
+		rqstp->rq_arg.page_len = 0;
+	} else
+		rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
+
+	rqstp->rq_xprt_ctxt   = NULL;
+	rqstp->rq_prot	      = IPPROTO_TCP;
+	if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
+		set_bit(RQ_LOCAL, &rqstp->rq_flags);
+	else
+		clear_bit(RQ_LOCAL, &rqstp->rq_flags);
+
+	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
+	calldir = p[1];
+	if (calldir)
+		len = receive_cb_reply(svsk, rqstp);
+
+	/* Reset TCP read info */
+	svsk->sk_datalen = 0;
+	svc_tcp_fragment_received(svsk);
+
+	if (len < 0)
+		goto error;
+
+	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
+	if (serv->sv_stats)
+		serv->sv_stats->nettcpcnt++;
+
+	return rqstp->rq_arg.len;
+
+error:
+	if (len != -EAGAIN)
+		goto err_delete;
+	dprintk("RPC: TCP recvfrom got EAGAIN\n");
+	return 0;
+err_delete:
+	printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
+	       svsk->sk_xprt.xpt_server->sv_name, -len);
+	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+err_noclose:
+	return 0;	/* record not complete */
+}
+
+/*
+ * Send out data on TCP socket.
+ */
+static int svc_tcp_sendto(struct svc_rqst *rqstp)
+{
+	struct xdr_buf	*xbufp = &rqstp->rq_res;
+	int sent;
+	__be32 reclen;
+
+	/* Set up the first element of the reply kvec.
+	 * Any other kvecs that may be in use have been taken
+	 * care of by the server implementation itself.
+	 */
+	reclen = htonl(0x80000000|((xbufp->len ) - 4));
+	memcpy(xbufp->head[0].iov_base, &reclen, 4);
+
+	sent = svc_sendto(rqstp, &rqstp->rq_res);
+	if (sent != xbufp->len) {
+		printk(KERN_NOTICE
+		       "rpc-srv/tcp: %s: %s %d when sending %d bytes "
+		       "- shutting down socket\n",
+		       rqstp->rq_xprt->xpt_server->sv_name,
+		       (sent<0)?"got error":"sent only",
+		       sent, xbufp->len);
+		set_bit(XPT_CLOSE, &rqstp->rq_xprt->xpt_flags);
+		svc_xprt_enqueue(rqstp->rq_xprt);
+		sent = -EAGAIN;
+	}
+	return sent;
+}
+
+/*
+ * Setup response header. TCP has a 4B record length field.
+ */
+static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
+{
+	struct kvec *resv = &rqstp->rq_res.head[0];
+
+	/* tcp needs a space for the record length... */
+	svc_putnl(resv, 0);
+}
+
+static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
+				       struct net *net,
+				       struct sockaddr *sa, int salen,
+				       int flags)
+{
+	return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
+}
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+static struct svc_xprt *svc_bc_create_socket(struct svc_serv *, int,
+					     struct net *, struct sockaddr *,
+					     int, int);
+static void svc_bc_sock_free(struct svc_xprt *xprt);
+
+static struct svc_xprt *svc_bc_tcp_create(struct svc_serv *serv,
+				       struct net *net,
+				       struct sockaddr *sa, int salen,
+				       int flags)
+{
+	return svc_bc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
+}
+
+static void svc_bc_tcp_sock_detach(struct svc_xprt *xprt)
+{
+}
+
+static struct svc_xprt_ops svc_tcp_bc_ops = {
+	.xpo_create = svc_bc_tcp_create,
+	.xpo_detach = svc_bc_tcp_sock_detach,
+	.xpo_free = svc_bc_sock_free,
+	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
+	.xpo_secure_port = svc_sock_secure_port,
+};
+
+static struct svc_xprt_class svc_tcp_bc_class = {
+	.xcl_name = "tcp-bc",
+	.xcl_owner = THIS_MODULE,
+	.xcl_ops = &svc_tcp_bc_ops,
+	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
+};
+
+static void svc_init_bc_xprt_sock(void)
+{
+	svc_reg_xprt_class(&svc_tcp_bc_class);
+}
+
+static void svc_cleanup_bc_xprt_sock(void)
+{
+	svc_unreg_xprt_class(&svc_tcp_bc_class);
+}
+#else /* CONFIG_SUNRPC_BACKCHANNEL */
+static void svc_init_bc_xprt_sock(void)
+{
+}
+
+static void svc_cleanup_bc_xprt_sock(void)
+{
+}
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
+static struct svc_xprt_ops svc_tcp_ops = {
+	.xpo_create = svc_tcp_create,
+	.xpo_recvfrom = svc_tcp_recvfrom,
+	.xpo_sendto = svc_tcp_sendto,
+	.xpo_release_rqst = svc_release_skb,
+	.xpo_detach = svc_tcp_sock_detach,
+	.xpo_free = svc_sock_free,
+	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
+	.xpo_has_wspace = svc_tcp_has_wspace,
+	.xpo_accept = svc_tcp_accept,
+	.xpo_secure_port = svc_sock_secure_port,
+	.xpo_adjust_wspace = svc_tcp_adjust_wspace,
+};
+
+static struct svc_xprt_class svc_tcp_class = {
+	.xcl_name = "tcp",
+	.xcl_owner = THIS_MODULE,
+	.xcl_ops = &svc_tcp_ops,
+	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
+	.xcl_ident = XPRT_TRANSPORT_TCP,
+};
+
+void svc_init_xprt_sock(void)
+{
+	svc_reg_xprt_class(&svc_tcp_class);
+	svc_reg_xprt_class(&svc_udp_class);
+	svc_init_bc_xprt_sock();
+}
+
+void svc_cleanup_xprt_sock(void)
+{
+	svc_unreg_xprt_class(&svc_tcp_class);
+	svc_unreg_xprt_class(&svc_udp_class);
+	svc_cleanup_bc_xprt_sock();
+}
+
+static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
+{
+	struct sock	*sk = svsk->sk_sk;
+
+	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
+		      &svsk->sk_xprt, serv);
+	set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
+	if (sk->sk_state == TCP_LISTEN) {
+		dprintk("setting up TCP socket for listening\n");
+		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
+		sk->sk_data_ready = svc_tcp_listen_data_ready;
+		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
+	} else {
+		dprintk("setting up TCP socket for reading\n");
+		sk->sk_state_change = svc_tcp_state_change;
+		sk->sk_data_ready = svc_tcp_data_ready;
+		sk->sk_write_space = svc_tcp_write_space;
+
+		svsk->sk_reclen = 0;
+		svsk->sk_tcplen = 0;
+		svsk->sk_datalen = 0;
+		memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
+
+		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
+
+		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
+		if (sk->sk_state != TCP_ESTABLISHED)
+			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
+	}
+}
+
+void svc_sock_update_bufs(struct svc_serv *serv)
+{
+	/*
+	 * The number of server threads has changed. Update
+	 * rcvbuf and sndbuf accordingly on all sockets
+	 */
+	struct svc_sock *svsk;
+
+	spin_lock_bh(&serv->sv_lock);
+	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
+		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
+	spin_unlock_bh(&serv->sv_lock);
+}
+EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
+
+/*
+ * 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 flags)
+{
+	struct svc_sock	*svsk;
+	struct sock	*inet;
+	int		pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
+	int		err = 0;
+
+	dprintk("svc: svc_setup_socket %p\n", sock);
+	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
+	if (!svsk)
+		return ERR_PTR(-ENOMEM);
+
+	inet = sock->sk;
+
+	/* Register socket with portmapper */
+	if (pmap_register)
+		err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
+				     inet->sk_protocol,
+				     ntohs(inet_sk(inet)->inet_sport));
+
+	if (err < 0) {
+		kfree(svsk);
+		return ERR_PTR(err);
+	}
+
+	inet->sk_user_data = svsk;
+	svsk->sk_sock = sock;
+	svsk->sk_sk = inet;
+	svsk->sk_ostate = inet->sk_state_change;
+	svsk->sk_odata = inet->sk_data_ready;
+	svsk->sk_owspace = inet->sk_write_space;
+
+	/* Initialize the socket */
+	if (sock->type == SOCK_DGRAM)
+		svc_udp_init(svsk, serv);
+	else {
+		/* initialise setting must have enough space to
+		 * receive and respond to one request.
+		 */
+		svc_sock_setbufsize(svsk->sk_sock, 4 * serv->sv_max_mesg,
+					4 * serv->sv_max_mesg);
+		svc_tcp_init(svsk, serv);
+	}
+
+	dprintk("svc: svc_setup_socket created %p (inet %p)\n",
+				svsk, svsk->sk_sk);
+
+	return svsk;
+}
+
+bool svc_alien_sock(struct net *net, int fd)
+{
+	int err;
+	struct socket *sock = sockfd_lookup(fd, &err);
+	bool ret = false;
+
+	if (!sock)
+		goto out;
+	if (sock_net(sock->sk) != net)
+		ret = true;
+	sockfd_put(sock);
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(svc_alien_sock);
+
+/**
+ * svc_addsock - add a listener socket to an RPC service
+ * @serv: pointer to RPC service to which to add a new listener
+ * @fd: file descriptor of the new listener
+ * @name_return: pointer to buffer to fill in with name of listener
+ * @len: size of the buffer
+ *
+ * Fills in socket name and returns positive length of name if successful.
+ * Name is terminated with '\n'.  On error, returns a negative errno
+ * value.
+ */
+int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
+		const size_t len)
+{
+	int err = 0;
+	struct socket *so = sockfd_lookup(fd, &err);
+	struct svc_sock *svsk = NULL;
+	struct sockaddr_storage addr;
+	struct sockaddr *sin = (struct sockaddr *)&addr;
+	int salen;
+
+	if (!so)
+		return err;
+	err = -EAFNOSUPPORT;
+	if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
+		goto out;
+	err =  -EPROTONOSUPPORT;
+	if (so->sk->sk_protocol != IPPROTO_TCP &&
+	    so->sk->sk_protocol != IPPROTO_UDP)
+		goto out;
+	err = -EISCONN;
+	if (so->state > SS_UNCONNECTED)
+		goto out;
+	err = -ENOENT;
+	if (!try_module_get(THIS_MODULE))
+		goto out;
+	svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
+	if (IS_ERR(svsk)) {
+		module_put(THIS_MODULE);
+		err = PTR_ERR(svsk);
+		goto out;
+	}
+	if (kernel_getsockname(svsk->sk_sock, sin, &salen) == 0)
+		svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
+	svc_add_new_perm_xprt(serv, &svsk->sk_xprt);
+	return svc_one_sock_name(svsk, name_return, len);
+out:
+	sockfd_put(so);
+	return err;
+}
+EXPORT_SYMBOL_GPL(svc_addsock);
+
+/*
+ * Create socket for RPC service.
+ */
+static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
+					  int protocol,
+					  struct net *net,
+					  struct sockaddr *sin, int len,
+					  int flags)
+{
+	struct svc_sock	*svsk;
+	struct socket	*sock;
+	int		error;
+	int		type;
+	struct sockaddr_storage addr;
+	struct sockaddr *newsin = (struct sockaddr *)&addr;
+	int		newlen;
+	int		family;
+	int		val;
+	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+
+	dprintk("svc: svc_create_socket(%s, %d, %s)\n",
+			serv->sv_program->pg_name, protocol,
+			__svc_print_addr(sin, buf, sizeof(buf)));
+
+	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
+		printk(KERN_WARNING "svc: only UDP and TCP "
+				"sockets supported\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
+	switch (sin->sa_family) {
+	case AF_INET6:
+		family = PF_INET6;
+		break;
+	case AF_INET:
+		family = PF_INET;
+		break;
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	error = __sock_create(net, family, type, protocol, &sock, 1);
+	if (error < 0)
+		return ERR_PTR(error);
+
+	svc_reclassify_socket(sock);
+
+	/*
+	 * If this is an PF_INET6 listener, we want to avoid
+	 * getting requests from IPv4 remotes.  Those should
+	 * be shunted to a PF_INET listener via rpcbind.
+	 */
+	val = 1;
+	if (family == PF_INET6)
+		kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
+					(char *)&val, sizeof(val));
+
+	if (type == SOCK_STREAM)
+		sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
+	error = kernel_bind(sock, sin, len);
+	if (error < 0)
+		goto bummer;
+
+	newlen = len;
+	error = kernel_getsockname(sock, newsin, &newlen);
+	if (error < 0)
+		goto bummer;
+
+	if (protocol == IPPROTO_TCP) {
+		if ((error = kernel_listen(sock, 64)) < 0)
+			goto bummer;
+	}
+
+	svsk = svc_setup_socket(serv, sock, flags);
+	if (IS_ERR(svsk)) {
+		error = PTR_ERR(svsk);
+		goto bummer;
+	}
+	svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
+	return (struct svc_xprt *)svsk;
+bummer:
+	dprintk("svc: svc_create_socket error = %d\n", -error);
+	sock_release(sock);
+	return ERR_PTR(error);
+}
+
+/*
+ * Detach the svc_sock from the socket so that no
+ * more callbacks occur.
+ */
+static void svc_sock_detach(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	struct sock *sk = svsk->sk_sk;
+	wait_queue_head_t *wq;
+
+	dprintk("svc: svc_sock_detach(%p)\n", svsk);
+
+	/* put back the old socket callbacks */
+	sk->sk_state_change = svsk->sk_ostate;
+	sk->sk_data_ready = svsk->sk_odata;
+	sk->sk_write_space = svsk->sk_owspace;
+
+	wq = sk_sleep(sk);
+	if (wq && waitqueue_active(wq))
+		wake_up_interruptible(wq);
+}
+
+/*
+ * Disconnect the socket, and reset the callbacks
+ */
+static void svc_tcp_sock_detach(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+
+	dprintk("svc: svc_tcp_sock_detach(%p)\n", svsk);
+
+	svc_sock_detach(xprt);
+
+	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
+		svc_tcp_clear_pages(svsk);
+		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
+	}
+}
+
+/*
+ * Free the svc_sock's socket resources and the svc_sock itself.
+ */
+static void svc_sock_free(struct svc_xprt *xprt)
+{
+	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
+	dprintk("svc: svc_sock_free(%p)\n", svsk);
+
+	if (svsk->sk_sock->file)
+		sockfd_put(svsk->sk_sock);
+	else
+		sock_release(svsk->sk_sock);
+	kfree(svsk);
+}
+
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+/*
+ * Create a back channel svc_xprt which shares the fore channel socket.
+ */
+static struct svc_xprt *svc_bc_create_socket(struct svc_serv *serv,
+					     int protocol,
+					     struct net *net,
+					     struct sockaddr *sin, int len,
+					     int flags)
+{
+	struct svc_sock *svsk;
+	struct svc_xprt *xprt;
+
+	if (protocol != IPPROTO_TCP) {
+		printk(KERN_WARNING "svc: only TCP sockets"
+			" supported on shared back channel\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
+	if (!svsk)
+		return ERR_PTR(-ENOMEM);
+
+	xprt = &svsk->sk_xprt;
+	svc_xprt_init(net, &svc_tcp_bc_class, xprt, serv);
+
+	serv->sv_bc_xprt = xprt;
+
+	return xprt;
+}
+
+/*
+ * Free a back channel svc_sock.
+ */
+static void svc_bc_sock_free(struct svc_xprt *xprt)
+{
+	if (xprt)
+		kfree(container_of(xprt, struct svc_sock, sk_xprt));
+}
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */