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v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * linux/net/sunrpc/svcsock.c
   4 *
   5 * These are the RPC server socket internals.
   6 *
   7 * The server scheduling algorithm does not always distribute the load
   8 * evenly when servicing a single client. May need to modify the
   9 * svc_xprt_enqueue procedure...
  10 *
  11 * TCP support is largely untested and may be a little slow. The problem
  12 * is that we currently do two separate recvfrom's, one for the 4-byte
  13 * record length, and the second for the actual record. This could possibly
  14 * be improved by always reading a minimum size of around 100 bytes and
  15 * tucking any superfluous bytes away in a temporary store. Still, that
  16 * leaves write requests out in the rain. An alternative may be to peek at
  17 * the first skb in the queue, and if it matches the next TCP sequence
  18 * number, to extract the record marker. Yuck.
  19 *
  20 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  21 */
  22
  23#include <linux/kernel.h>
  24#include <linux/sched.h>
  25#include <linux/module.h>
  26#include <linux/errno.h>
  27#include <linux/fcntl.h>
  28#include <linux/net.h>
  29#include <linux/in.h>
  30#include <linux/inet.h>
  31#include <linux/udp.h>
  32#include <linux/tcp.h>
  33#include <linux/unistd.h>
  34#include <linux/slab.h>
  35#include <linux/netdevice.h>
  36#include <linux/skbuff.h>
  37#include <linux/file.h>
  38#include <linux/freezer.h>
  39#include <net/sock.h>
  40#include <net/checksum.h>
  41#include <net/ip.h>
  42#include <net/ipv6.h>
  43#include <net/udp.h>
  44#include <net/tcp.h>
  45#include <net/tcp_states.h>
  46#include <linux/uaccess.h>
  47#include <asm/ioctls.h>
  48#include <trace/events/skb.h>
  49
  50#include <linux/sunrpc/types.h>
  51#include <linux/sunrpc/clnt.h>
  52#include <linux/sunrpc/xdr.h>
  53#include <linux/sunrpc/msg_prot.h>
  54#include <linux/sunrpc/svcsock.h>
  55#include <linux/sunrpc/stats.h>
  56#include <linux/sunrpc/xprt.h>
  57
  58#include "sunrpc.h"
  59
  60#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
  61
  62
  63static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
  64					 int flags);
  65static int		svc_udp_recvfrom(struct svc_rqst *);
  66static int		svc_udp_sendto(struct svc_rqst *);
  67static void		svc_sock_detach(struct svc_xprt *);
  68static void		svc_tcp_sock_detach(struct svc_xprt *);
  69static void		svc_sock_free(struct svc_xprt *);
  70
  71static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
  72					  struct net *, struct sockaddr *,
  73					  int, int);
 
 
 
 
 
 
 
  74#ifdef CONFIG_DEBUG_LOCK_ALLOC
  75static struct lock_class_key svc_key[2];
  76static struct lock_class_key svc_slock_key[2];
  77
  78static void svc_reclassify_socket(struct socket *sock)
  79{
  80	struct sock *sk = sock->sk;
  81
  82	if (WARN_ON_ONCE(!sock_allow_reclassification(sk)))
  83		return;
  84
  85	switch (sk->sk_family) {
  86	case AF_INET:
  87		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
  88					      &svc_slock_key[0],
  89					      "sk_xprt.xpt_lock-AF_INET-NFSD",
  90					      &svc_key[0]);
  91		break;
  92
  93	case AF_INET6:
  94		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
  95					      &svc_slock_key[1],
  96					      "sk_xprt.xpt_lock-AF_INET6-NFSD",
  97					      &svc_key[1]);
  98		break;
  99
 100	default:
 101		BUG();
 102	}
 103}
 104#else
 105static void svc_reclassify_socket(struct socket *sock)
 106{
 107}
 108#endif
 109
 110/*
 111 * Release an skbuff after use
 112 */
 113static void svc_release_skb(struct svc_rqst *rqstp)
 114{
 115	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
 116
 117	if (skb) {
 118		struct svc_sock *svsk =
 119			container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 120		rqstp->rq_xprt_ctxt = NULL;
 121
 122		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
 123		skb_free_datagram_locked(svsk->sk_sk, skb);
 124	}
 125}
 126
 127static void svc_release_udp_skb(struct svc_rqst *rqstp)
 128{
 129	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
 130
 131	if (skb) {
 132		rqstp->rq_xprt_ctxt = NULL;
 133
 134		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
 135		consume_skb(skb);
 136	}
 137}
 138
 139union svc_pktinfo_u {
 140	struct in_pktinfo pkti;
 141	struct in6_pktinfo pkti6;
 142};
 143#define SVC_PKTINFO_SPACE \
 144	CMSG_SPACE(sizeof(union svc_pktinfo_u))
 145
 146static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
 147{
 148	struct svc_sock *svsk =
 149		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 150	switch (svsk->sk_sk->sk_family) {
 151	case AF_INET: {
 152			struct in_pktinfo *pki = CMSG_DATA(cmh);
 153
 154			cmh->cmsg_level = SOL_IP;
 155			cmh->cmsg_type = IP_PKTINFO;
 156			pki->ipi_ifindex = 0;
 157			pki->ipi_spec_dst.s_addr =
 158				 svc_daddr_in(rqstp)->sin_addr.s_addr;
 159			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 160		}
 161		break;
 162
 163	case AF_INET6: {
 164			struct in6_pktinfo *pki = CMSG_DATA(cmh);
 165			struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 166
 167			cmh->cmsg_level = SOL_IPV6;
 168			cmh->cmsg_type = IPV6_PKTINFO;
 169			pki->ipi6_ifindex = daddr->sin6_scope_id;
 170			pki->ipi6_addr = daddr->sin6_addr;
 171			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 172		}
 173		break;
 174	}
 175}
 176
 177/*
 178 * send routine intended to be shared by the fore- and back-channel
 179 */
 180int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
 181		    struct page *headpage, unsigned long headoffset,
 182		    struct page *tailpage, unsigned long tailoffset)
 183{
 184	int		result;
 185	int		size;
 186	struct page	**ppage = xdr->pages;
 187	size_t		base = xdr->page_base;
 188	unsigned int	pglen = xdr->page_len;
 189	unsigned int	flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
 190	int		slen;
 191	int		len = 0;
 192
 193	slen = xdr->len;
 194
 195	/* send head */
 196	if (slen == xdr->head[0].iov_len)
 197		flags = 0;
 198	len = kernel_sendpage(sock, headpage, headoffset,
 199				  xdr->head[0].iov_len, flags);
 200	if (len != xdr->head[0].iov_len)
 201		goto out;
 202	slen -= xdr->head[0].iov_len;
 203	if (slen == 0)
 204		goto out;
 205
 206	/* send page data */
 207	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
 208	while (pglen > 0) {
 209		if (slen == size)
 210			flags = 0;
 211		result = kernel_sendpage(sock, *ppage, base, size, flags);
 212		if (result > 0)
 213			len += result;
 214		if (result != size)
 215			goto out;
 216		slen -= size;
 217		pglen -= size;
 218		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
 219		base = 0;
 220		ppage++;
 221	}
 222
 223	/* send tail */
 224	if (xdr->tail[0].iov_len) {
 225		result = kernel_sendpage(sock, tailpage, tailoffset,
 226				   xdr->tail[0].iov_len, 0);
 227		if (result > 0)
 228			len += result;
 229	}
 230
 231out:
 232	return len;
 233}
 234
 235
 236/*
 237 * Generic sendto routine
 238 */
 239static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
 240{
 241	struct svc_sock	*svsk =
 242		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 243	struct socket	*sock = svsk->sk_sock;
 244	union {
 245		struct cmsghdr	hdr;
 246		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 247	} buffer;
 248	struct cmsghdr *cmh = &buffer.hdr;
 249	int		len = 0;
 250	unsigned long tailoff;
 251	unsigned long headoff;
 252	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 253
 254	if (rqstp->rq_prot == IPPROTO_UDP) {
 255		struct msghdr msg = {
 256			.msg_name	= &rqstp->rq_addr,
 257			.msg_namelen	= rqstp->rq_addrlen,
 258			.msg_control	= cmh,
 259			.msg_controllen	= sizeof(buffer),
 260			.msg_flags	= MSG_MORE,
 261		};
 262
 263		svc_set_cmsg_data(rqstp, cmh);
 264
 265		if (sock_sendmsg(sock, &msg) < 0)
 266			goto out;
 267	}
 268
 269	tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
 270	headoff = 0;
 271	len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
 272			       rqstp->rq_respages[0], tailoff);
 273
 274out:
 275	dprintk("svc: socket %p sendto([%p %zu... ], %d) = %d (addr %s)\n",
 276		svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
 277		xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
 278
 279	return len;
 280}
 281
 282/*
 283 * Report socket names for nfsdfs
 284 */
 285static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
 286{
 287	const struct sock *sk = svsk->sk_sk;
 288	const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
 289							"udp" : "tcp";
 290	int len;
 291
 292	switch (sk->sk_family) {
 293	case PF_INET:
 294		len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
 295				proto_name,
 296				&inet_sk(sk)->inet_rcv_saddr,
 297				inet_sk(sk)->inet_num);
 298		break;
 299#if IS_ENABLED(CONFIG_IPV6)
 300	case PF_INET6:
 301		len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
 302				proto_name,
 303				&sk->sk_v6_rcv_saddr,
 304				inet_sk(sk)->inet_num);
 305		break;
 306#endif
 307	default:
 308		len = snprintf(buf, remaining, "*unknown-%d*\n",
 309				sk->sk_family);
 310	}
 311
 312	if (len >= remaining) {
 313		*buf = '\0';
 314		return -ENAMETOOLONG;
 315	}
 316	return len;
 317}
 318
 319/*
 320 * Generic recvfrom routine.
 321 */
 322static ssize_t svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov,
 323			    unsigned int nr, size_t buflen, unsigned int base)
 324{
 325	struct svc_sock *svsk =
 326		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 327	struct msghdr msg = { NULL };
 328	ssize_t len;
 
 
 329
 330	rqstp->rq_xprt_hlen = 0;
 331
 332	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 333	iov_iter_kvec(&msg.msg_iter, READ, iov, nr, buflen);
 334	if (base != 0) {
 335		iov_iter_advance(&msg.msg_iter, base);
 336		buflen -= base;
 337	}
 338	len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
 339	/* If we read a full record, then assume there may be more
 340	 * data to read (stream based sockets only!)
 341	 */
 342	if (len == buflen)
 343		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 344
 345	dprintk("svc: socket %p recvfrom(%p, %zu) = %zd\n",
 346		svsk, iov[0].iov_base, iov[0].iov_len, len);
 347	return len;
 348}
 349
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 350/*
 351 * Set socket snd and rcv buffer lengths
 352 */
 353static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
 
 354{
 355	unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg;
 356	struct socket *sock = svsk->sk_sock;
 357
 358	nreqs = min(nreqs, INT_MAX / 2 / max_mesg);
 359
 360	lock_sock(sock->sk);
 361	sock->sk->sk_sndbuf = nreqs * max_mesg * 2;
 362	sock->sk->sk_rcvbuf = nreqs * max_mesg * 2;
 363	sock->sk->sk_write_space(sock->sk);
 364	release_sock(sock->sk);
 365}
 366
 367static void svc_sock_secure_port(struct svc_rqst *rqstp)
 368{
 369	if (svc_port_is_privileged(svc_addr(rqstp)))
 370		set_bit(RQ_SECURE, &rqstp->rq_flags);
 371	else
 372		clear_bit(RQ_SECURE, &rqstp->rq_flags);
 373}
 374
 375/*
 376 * INET callback when data has been received on the socket.
 377 */
 378static void svc_data_ready(struct sock *sk)
 379{
 380	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 381
 382	if (svsk) {
 383		dprintk("svc: socket %p(inet %p), busy=%d\n",
 384			svsk, sk,
 385			test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
 386
 387		/* Refer to svc_setup_socket() for details. */
 388		rmb();
 389		svsk->sk_odata(sk);
 390		if (!test_and_set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags))
 391			svc_xprt_enqueue(&svsk->sk_xprt);
 392	}
 393}
 394
 395/*
 396 * INET callback when space is newly available on the socket.
 397 */
 398static void svc_write_space(struct sock *sk)
 399{
 400	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
 401
 402	if (svsk) {
 403		dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
 404			svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
 405
 406		/* Refer to svc_setup_socket() for details. */
 407		rmb();
 408		svsk->sk_owspace(sk);
 409		svc_xprt_enqueue(&svsk->sk_xprt);
 410	}
 411}
 412
 413static int svc_tcp_has_wspace(struct svc_xprt *xprt)
 414{
 415	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 416
 417	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
 418		return 1;
 419	return !test_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 420}
 421
 422static void svc_tcp_kill_temp_xprt(struct svc_xprt *xprt)
 423{
 424	struct svc_sock *svsk;
 425	struct socket *sock;
 426	struct linger no_linger = {
 427		.l_onoff = 1,
 428		.l_linger = 0,
 429	};
 430
 431	svsk = container_of(xprt, struct svc_sock, sk_xprt);
 432	sock = svsk->sk_sock;
 433	kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
 434			  (char *)&no_linger, sizeof(no_linger));
 435}
 436
 437/*
 438 * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
 439 */
 440static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
 441				     struct cmsghdr *cmh)
 442{
 443	struct in_pktinfo *pki = CMSG_DATA(cmh);
 444	struct sockaddr_in *daddr = svc_daddr_in(rqstp);
 445
 446	if (cmh->cmsg_type != IP_PKTINFO)
 447		return 0;
 448
 449	daddr->sin_family = AF_INET;
 450	daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
 451	return 1;
 452}
 453
 454/*
 455 * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
 456 */
 457static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
 458				     struct cmsghdr *cmh)
 459{
 460	struct in6_pktinfo *pki = CMSG_DATA(cmh);
 461	struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 462
 463	if (cmh->cmsg_type != IPV6_PKTINFO)
 464		return 0;
 465
 466	daddr->sin6_family = AF_INET6;
 467	daddr->sin6_addr = pki->ipi6_addr;
 468	daddr->sin6_scope_id = pki->ipi6_ifindex;
 469	return 1;
 470}
 471
 472/*
 473 * Copy the UDP datagram's destination address to the rqstp structure.
 474 * The 'destination' address in this case is the address to which the
 475 * peer sent the datagram, i.e. our local address. For multihomed
 476 * hosts, this can change from msg to msg. Note that only the IP
 477 * address changes, the port number should remain the same.
 478 */
 479static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
 480				    struct cmsghdr *cmh)
 481{
 482	switch (cmh->cmsg_level) {
 483	case SOL_IP:
 484		return svc_udp_get_dest_address4(rqstp, cmh);
 485	case SOL_IPV6:
 486		return svc_udp_get_dest_address6(rqstp, cmh);
 487	}
 488
 489	return 0;
 490}
 491
 492/*
 493 * Receive a datagram from a UDP socket.
 494 */
 495static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 496{
 497	struct svc_sock	*svsk =
 498		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 499	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 500	struct sk_buff	*skb;
 501	union {
 502		struct cmsghdr	hdr;
 503		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 504	} buffer;
 505	struct cmsghdr *cmh = &buffer.hdr;
 506	struct msghdr msg = {
 507		.msg_name = svc_addr(rqstp),
 508		.msg_control = cmh,
 509		.msg_controllen = sizeof(buffer),
 510		.msg_flags = MSG_DONTWAIT,
 511	};
 512	size_t len;
 513	int err;
 514
 515	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
 516	    /* udp sockets need large rcvbuf as all pending
 517	     * requests are still in that buffer.  sndbuf must
 518	     * also be large enough that there is enough space
 519	     * for one reply per thread.  We count all threads
 520	     * rather than threads in a particular pool, which
 521	     * provides an upper bound on the number of threads
 522	     * which will access the socket.
 523	     */
 524	    svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3);
 
 
 525
 526	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 527	skb = NULL;
 528	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
 529			     0, 0, MSG_PEEK | MSG_DONTWAIT);
 530	if (err >= 0)
 531		skb = skb_recv_udp(svsk->sk_sk, 0, 1, &err);
 532
 533	if (skb == NULL) {
 534		if (err != -EAGAIN) {
 535			/* possibly an icmp error */
 536			dprintk("svc: recvfrom returned error %d\n", -err);
 537			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 538		}
 539		return 0;
 540	}
 541	len = svc_addr_len(svc_addr(rqstp));
 542	rqstp->rq_addrlen = len;
 543	if (skb->tstamp == 0) {
 544		skb->tstamp = ktime_get_real();
 545		/* Don't enable netstamp, sunrpc doesn't
 546		   need that much accuracy */
 547	}
 548	sock_write_timestamp(svsk->sk_sk, skb->tstamp);
 549	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
 550
 551	len  = skb->len;
 552	rqstp->rq_arg.len = len;
 553
 554	rqstp->rq_prot = IPPROTO_UDP;
 555
 556	if (!svc_udp_get_dest_address(rqstp, cmh)) {
 557		net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
 558				     cmh->cmsg_level, cmh->cmsg_type);
 559		goto out_free;
 560	}
 561	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
 562
 563	if (skb_is_nonlinear(skb)) {
 564		/* we have to copy */
 565		local_bh_disable();
 566		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
 567			local_bh_enable();
 568			/* checksum error */
 569			goto out_free;
 570		}
 571		local_bh_enable();
 572		consume_skb(skb);
 573	} else {
 574		/* we can use it in-place */
 575		rqstp->rq_arg.head[0].iov_base = skb->data;
 576		rqstp->rq_arg.head[0].iov_len = len;
 577		if (skb_checksum_complete(skb))
 578			goto out_free;
 579		rqstp->rq_xprt_ctxt = skb;
 580	}
 581
 582	rqstp->rq_arg.page_base = 0;
 583	if (len <= rqstp->rq_arg.head[0].iov_len) {
 584		rqstp->rq_arg.head[0].iov_len = len;
 585		rqstp->rq_arg.page_len = 0;
 586		rqstp->rq_respages = rqstp->rq_pages+1;
 587	} else {
 588		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
 589		rqstp->rq_respages = rqstp->rq_pages + 1 +
 590			DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
 591	}
 592	rqstp->rq_next_page = rqstp->rq_respages+1;
 593
 594	if (serv->sv_stats)
 595		serv->sv_stats->netudpcnt++;
 596
 597	return len;
 598out_free:
 599	kfree_skb(skb);
 600	return 0;
 601}
 602
 603static int
 604svc_udp_sendto(struct svc_rqst *rqstp)
 605{
 606	int		error;
 607
 608	error = svc_sendto(rqstp, &rqstp->rq_res);
 609	if (error == -ECONNREFUSED)
 610		/* ICMP error on earlier request. */
 611		error = svc_sendto(rqstp, &rqstp->rq_res);
 612
 613	return error;
 614}
 615
 
 
 
 
 616static int svc_udp_has_wspace(struct svc_xprt *xprt)
 617{
 618	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 619	struct svc_serv	*serv = xprt->xpt_server;
 620	unsigned long required;
 621
 622	/*
 623	 * Set the SOCK_NOSPACE flag before checking the available
 624	 * sock space.
 625	 */
 626	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 627	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
 628	if (required*2 > sock_wspace(svsk->sk_sk))
 629		return 0;
 630	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 631	return 1;
 632}
 633
 634static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
 635{
 636	BUG();
 637	return NULL;
 638}
 639
 640static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt)
 641{
 642}
 643
 644static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
 645				       struct net *net,
 646				       struct sockaddr *sa, int salen,
 647				       int flags)
 648{
 649	return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
 650}
 651
 652static const struct svc_xprt_ops svc_udp_ops = {
 653	.xpo_create = svc_udp_create,
 654	.xpo_recvfrom = svc_udp_recvfrom,
 655	.xpo_sendto = svc_udp_sendto,
 656	.xpo_release_rqst = svc_release_udp_skb,
 657	.xpo_detach = svc_sock_detach,
 658	.xpo_free = svc_sock_free,
 
 659	.xpo_has_wspace = svc_udp_has_wspace,
 660	.xpo_accept = svc_udp_accept,
 661	.xpo_secure_port = svc_sock_secure_port,
 662	.xpo_kill_temp_xprt = svc_udp_kill_temp_xprt,
 663};
 664
 665static struct svc_xprt_class svc_udp_class = {
 666	.xcl_name = "udp",
 667	.xcl_owner = THIS_MODULE,
 668	.xcl_ops = &svc_udp_ops,
 669	.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
 670	.xcl_ident = XPRT_TRANSPORT_UDP,
 671};
 672
 673static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
 674{
 675	int err, level, optname, one = 1;
 676
 677	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class,
 678		      &svsk->sk_xprt, serv);
 679	clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
 680	svsk->sk_sk->sk_data_ready = svc_data_ready;
 681	svsk->sk_sk->sk_write_space = svc_write_space;
 682
 683	/* initialise setting must have enough space to
 684	 * receive and respond to one request.
 685	 * svc_udp_recvfrom will re-adjust if necessary
 686	 */
 687	svc_sock_setbufsize(svsk, 3);
 
 
 688
 689	/* data might have come in before data_ready set up */
 690	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 691	set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
 692
 693	/* make sure we get destination address info */
 694	switch (svsk->sk_sk->sk_family) {
 695	case AF_INET:
 696		level = SOL_IP;
 697		optname = IP_PKTINFO;
 698		break;
 699	case AF_INET6:
 700		level = SOL_IPV6;
 701		optname = IPV6_RECVPKTINFO;
 702		break;
 703	default:
 704		BUG();
 705	}
 706	err = kernel_setsockopt(svsk->sk_sock, level, optname,
 707					(char *)&one, sizeof(one));
 708	dprintk("svc: kernel_setsockopt returned %d\n", err);
 709}
 710
 711/*
 712 * A data_ready event on a listening socket means there's a connection
 713 * pending. Do not use state_change as a substitute for it.
 714 */
 715static void svc_tcp_listen_data_ready(struct sock *sk)
 716{
 717	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 718
 719	dprintk("svc: socket %p TCP (listen) state change %d\n",
 720		sk, sk->sk_state);
 721
 722	if (svsk) {
 723		/* Refer to svc_setup_socket() for details. */
 724		rmb();
 725		svsk->sk_odata(sk);
 726	}
 727
 728	/*
 729	 * This callback may called twice when a new connection
 730	 * is established as a child socket inherits everything
 731	 * from a parent LISTEN socket.
 732	 * 1) data_ready method of the parent socket will be called
 733	 *    when one of child sockets become ESTABLISHED.
 734	 * 2) data_ready method of the child socket may be called
 735	 *    when it receives data before the socket is accepted.
 736	 * In case of 2, we should ignore it silently.
 737	 */
 738	if (sk->sk_state == TCP_LISTEN) {
 739		if (svsk) {
 740			set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 741			svc_xprt_enqueue(&svsk->sk_xprt);
 742		} else
 743			printk("svc: socket %p: no user data\n", sk);
 744	}
 745}
 746
 747/*
 748 * A state change on a connected socket means it's dying or dead.
 749 */
 750static void svc_tcp_state_change(struct sock *sk)
 751{
 752	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 753
 754	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
 755		sk, sk->sk_state, sk->sk_user_data);
 756
 757	if (!svsk)
 758		printk("svc: socket %p: no user data\n", sk);
 759	else {
 760		/* Refer to svc_setup_socket() for details. */
 761		rmb();
 762		svsk->sk_ostate(sk);
 763		if (sk->sk_state != TCP_ESTABLISHED) {
 764			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 765			svc_xprt_enqueue(&svsk->sk_xprt);
 766		}
 767	}
 768}
 769
 770/*
 771 * Accept a TCP connection
 772 */
 773static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
 774{
 775	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 776	struct sockaddr_storage addr;
 777	struct sockaddr	*sin = (struct sockaddr *) &addr;
 778	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 779	struct socket	*sock = svsk->sk_sock;
 780	struct socket	*newsock;
 781	struct svc_sock	*newsvsk;
 782	int		err, slen;
 783	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 784
 785	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
 786	if (!sock)
 787		return NULL;
 788
 789	clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 790	err = kernel_accept(sock, &newsock, O_NONBLOCK);
 791	if (err < 0) {
 792		if (err == -ENOMEM)
 793			printk(KERN_WARNING "%s: no more sockets!\n",
 794			       serv->sv_name);
 795		else if (err != -EAGAIN)
 796			net_warn_ratelimited("%s: accept failed (err %d)!\n",
 797					     serv->sv_name, -err);
 798		return NULL;
 799	}
 800	set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 801
 802	err = kernel_getpeername(newsock, sin);
 803	if (err < 0) {
 804		net_warn_ratelimited("%s: peername failed (err %d)!\n",
 805				     serv->sv_name, -err);
 806		goto failed;		/* aborted connection or whatever */
 807	}
 808	slen = err;
 809
 810	/* Ideally, we would want to reject connections from unauthorized
 811	 * hosts here, but when we get encryption, the IP of the host won't
 812	 * tell us anything.  For now just warn about unpriv connections.
 813	 */
 814	if (!svc_port_is_privileged(sin)) {
 815		dprintk("%s: connect from unprivileged port: %s\n",
 816			serv->sv_name,
 817			__svc_print_addr(sin, buf, sizeof(buf)));
 818	}
 819	dprintk("%s: connect from %s\n", serv->sv_name,
 820		__svc_print_addr(sin, buf, sizeof(buf)));
 821
 822	/* Reset the inherited callbacks before calling svc_setup_socket */
 823	newsock->sk->sk_state_change = svsk->sk_ostate;
 824	newsock->sk->sk_data_ready = svsk->sk_odata;
 825	newsock->sk->sk_write_space = svsk->sk_owspace;
 826
 827	/* make sure that a write doesn't block forever when
 828	 * low on memory
 829	 */
 830	newsock->sk->sk_sndtimeo = HZ*30;
 831
 832	newsvsk = svc_setup_socket(serv, newsock,
 833				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
 834	if (IS_ERR(newsvsk))
 835		goto failed;
 836	svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
 837	err = kernel_getsockname(newsock, sin);
 838	slen = err;
 839	if (unlikely(err < 0)) {
 840		dprintk("svc_tcp_accept: kernel_getsockname error %d\n", -err);
 841		slen = offsetof(struct sockaddr, sa_data);
 842	}
 843	svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
 844
 845	if (sock_is_loopback(newsock->sk))
 846		set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 847	else
 848		clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 849	if (serv->sv_stats)
 850		serv->sv_stats->nettcpconn++;
 851
 852	return &newsvsk->sk_xprt;
 853
 854failed:
 855	sock_release(newsock);
 856	return NULL;
 857}
 858
 859static unsigned int svc_tcp_restore_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 860{
 861	unsigned int i, len, npages;
 862
 863	if (svsk->sk_datalen == 0)
 864		return 0;
 865	len = svsk->sk_datalen;
 866	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 867	for (i = 0; i < npages; i++) {
 868		if (rqstp->rq_pages[i] != NULL)
 869			put_page(rqstp->rq_pages[i]);
 870		BUG_ON(svsk->sk_pages[i] == NULL);
 871		rqstp->rq_pages[i] = svsk->sk_pages[i];
 872		svsk->sk_pages[i] = NULL;
 873	}
 874	rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
 875	return len;
 876}
 877
 878static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 879{
 880	unsigned int i, len, npages;
 881
 882	if (svsk->sk_datalen == 0)
 883		return;
 884	len = svsk->sk_datalen;
 885	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 886	for (i = 0; i < npages; i++) {
 887		svsk->sk_pages[i] = rqstp->rq_pages[i];
 888		rqstp->rq_pages[i] = NULL;
 889	}
 890}
 891
 892static void svc_tcp_clear_pages(struct svc_sock *svsk)
 893{
 894	unsigned int i, len, npages;
 895
 896	if (svsk->sk_datalen == 0)
 897		goto out;
 898	len = svsk->sk_datalen;
 899	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 900	for (i = 0; i < npages; i++) {
 901		if (svsk->sk_pages[i] == NULL) {
 902			WARN_ON_ONCE(1);
 903			continue;
 904		}
 905		put_page(svsk->sk_pages[i]);
 906		svsk->sk_pages[i] = NULL;
 907	}
 908out:
 909	svsk->sk_tcplen = 0;
 910	svsk->sk_datalen = 0;
 911}
 912
 913/*
 914 * Receive fragment record header.
 915 * If we haven't gotten the record length yet, get the next four bytes.
 916 */
 917static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
 918{
 919	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 920	unsigned int want;
 921	int len;
 922
 923	if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
 924		struct kvec	iov;
 925
 926		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
 927		iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
 928		iov.iov_len  = want;
 929		len = svc_recvfrom(rqstp, &iov, 1, want, 0);
 930		if (len < 0)
 931			goto error;
 932		svsk->sk_tcplen += len;
 933
 934		if (len < want) {
 935			dprintk("svc: short recvfrom while reading record "
 936				"length (%d of %d)\n", len, want);
 937			return -EAGAIN;
 938		}
 939
 940		dprintk("svc: TCP record, %d bytes\n", svc_sock_reclen(svsk));
 941		if (svc_sock_reclen(svsk) + svsk->sk_datalen >
 942							serv->sv_max_mesg) {
 943			net_notice_ratelimited("RPC: fragment too large: %d\n",
 944					svc_sock_reclen(svsk));
 945			goto err_delete;
 946		}
 947	}
 948
 949	return svc_sock_reclen(svsk);
 950error:
 951	dprintk("RPC: TCP recv_record got %d\n", len);
 952	return len;
 953err_delete:
 954	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 955	return -EAGAIN;
 956}
 957
 958static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
 959{
 960	struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
 961	struct rpc_rqst *req = NULL;
 962	struct kvec *src, *dst;
 963	__be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
 964	__be32 xid;
 965	__be32 calldir;
 966
 967	xid = *p++;
 968	calldir = *p;
 969
 970	if (!bc_xprt)
 971		return -EAGAIN;
 972	spin_lock(&bc_xprt->queue_lock);
 973	req = xprt_lookup_rqst(bc_xprt, xid);
 974	if (!req)
 975		goto unlock_notfound;
 976
 977	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
 978	/*
 979	 * XXX!: cheating for now!  Only copying HEAD.
 980	 * But we know this is good enough for now (in fact, for any
 981	 * callback reply in the forseeable future).
 982	 */
 983	dst = &req->rq_private_buf.head[0];
 984	src = &rqstp->rq_arg.head[0];
 985	if (dst->iov_len < src->iov_len)
 986		goto unlock_eagain; /* whatever; just giving up. */
 987	memcpy(dst->iov_base, src->iov_base, src->iov_len);
 988	xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
 989	rqstp->rq_arg.len = 0;
 990	spin_unlock(&bc_xprt->queue_lock);
 991	return 0;
 992unlock_notfound:
 993	printk(KERN_NOTICE
 994		"%s: Got unrecognized reply: "
 995		"calldir 0x%x xpt_bc_xprt %p xid %08x\n",
 996		__func__, ntohl(calldir),
 997		bc_xprt, ntohl(xid));
 998unlock_eagain:
 999	spin_unlock(&bc_xprt->queue_lock);
1000	return -EAGAIN;
1001}
1002
1003static int copy_pages_to_kvecs(struct kvec *vec, struct page **pages, int len)
1004{
1005	int i = 0;
1006	int t = 0;
1007
1008	while (t < len) {
1009		vec[i].iov_base = page_address(pages[i]);
1010		vec[i].iov_len = PAGE_SIZE;
1011		i++;
1012		t += PAGE_SIZE;
1013	}
1014	return i;
1015}
1016
1017static void svc_tcp_fragment_received(struct svc_sock *svsk)
1018{
1019	/* If we have more data, signal svc_xprt_enqueue() to try again */
1020	dprintk("svc: TCP %s record (%d bytes)\n",
1021		svc_sock_final_rec(svsk) ? "final" : "nonfinal",
1022		svc_sock_reclen(svsk));
1023	svsk->sk_tcplen = 0;
1024	svsk->sk_reclen = 0;
1025}
1026
1027/*
1028 * Receive data from a TCP socket.
1029 */
1030static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
1031{
1032	struct svc_sock	*svsk =
1033		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
1034	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
1035	int		len;
1036	struct kvec *vec;
1037	unsigned int want, base;
1038	__be32 *p;
1039	__be32 calldir;
1040	int pnum;
1041
1042	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
1043		svsk, test_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags),
1044		test_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags),
1045		test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
1046
1047	len = svc_tcp_recv_record(svsk, rqstp);
1048	if (len < 0)
1049		goto error;
1050
1051	base = svc_tcp_restore_pages(svsk, rqstp);
1052	want = svc_sock_reclen(svsk) - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
1053
1054	vec = rqstp->rq_vec;
1055
1056	pnum = copy_pages_to_kvecs(&vec[0], &rqstp->rq_pages[0], base + want);
 
1057
1058	rqstp->rq_respages = &rqstp->rq_pages[pnum];
1059	rqstp->rq_next_page = rqstp->rq_respages + 1;
1060
1061	/* Now receive data */
1062	len = svc_recvfrom(rqstp, vec, pnum, base + want, base);
1063	if (len >= 0) {
1064		svsk->sk_tcplen += len;
1065		svsk->sk_datalen += len;
1066	}
1067	if (len != want || !svc_sock_final_rec(svsk)) {
1068		svc_tcp_save_pages(svsk, rqstp);
1069		if (len < 0 && len != -EAGAIN)
1070			goto err_delete;
1071		if (len == want)
1072			svc_tcp_fragment_received(svsk);
1073		else
1074			dprintk("svc: incomplete TCP record (%d of %d)\n",
1075				(int)(svsk->sk_tcplen - sizeof(rpc_fraghdr)),
1076				svc_sock_reclen(svsk));
1077		goto err_noclose;
1078	}
1079
1080	if (svsk->sk_datalen < 8) {
1081		svsk->sk_datalen = 0;
1082		goto err_delete; /* client is nuts. */
1083	}
1084
1085	rqstp->rq_arg.len = svsk->sk_datalen;
1086	rqstp->rq_arg.page_base = 0;
1087	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1088		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1089		rqstp->rq_arg.page_len = 0;
1090	} else
1091		rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1092
1093	rqstp->rq_xprt_ctxt   = NULL;
1094	rqstp->rq_prot	      = IPPROTO_TCP;
1095	if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
1096		set_bit(RQ_LOCAL, &rqstp->rq_flags);
1097	else
1098		clear_bit(RQ_LOCAL, &rqstp->rq_flags);
1099
1100	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1101	calldir = p[1];
1102	if (calldir)
1103		len = receive_cb_reply(svsk, rqstp);
1104
1105	/* Reset TCP read info */
1106	svsk->sk_datalen = 0;
1107	svc_tcp_fragment_received(svsk);
1108
1109	if (len < 0)
1110		goto error;
1111
1112	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
1113	if (serv->sv_stats)
1114		serv->sv_stats->nettcpcnt++;
1115
1116	return rqstp->rq_arg.len;
1117
1118error:
1119	if (len != -EAGAIN)
1120		goto err_delete;
1121	dprintk("RPC: TCP recvfrom got EAGAIN\n");
1122	return 0;
1123err_delete:
1124	printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
1125	       svsk->sk_xprt.xpt_server->sv_name, -len);
1126	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1127err_noclose:
1128	return 0;	/* record not complete */
1129}
1130
1131/*
1132 * Send out data on TCP socket.
1133 */
1134static int svc_tcp_sendto(struct svc_rqst *rqstp)
1135{
1136	struct xdr_buf	*xbufp = &rqstp->rq_res;
1137	int sent;
1138	__be32 reclen;
1139
1140	/* Set up the first element of the reply kvec.
1141	 * Any other kvecs that may be in use have been taken
1142	 * care of by the server implementation itself.
1143	 */
1144	reclen = htonl(0x80000000|((xbufp->len ) - 4));
1145	memcpy(xbufp->head[0].iov_base, &reclen, 4);
1146
1147	sent = svc_sendto(rqstp, &rqstp->rq_res);
1148	if (sent != xbufp->len) {
1149		printk(KERN_NOTICE
1150		       "rpc-srv/tcp: %s: %s %d when sending %d bytes "
1151		       "- shutting down socket\n",
1152		       rqstp->rq_xprt->xpt_server->sv_name,
1153		       (sent<0)?"got error":"sent only",
1154		       sent, xbufp->len);
1155		set_bit(XPT_CLOSE, &rqstp->rq_xprt->xpt_flags);
1156		svc_xprt_enqueue(rqstp->rq_xprt);
1157		sent = -EAGAIN;
1158	}
1159	return sent;
1160}
1161
 
 
 
 
 
 
 
 
 
 
 
1162static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1163				       struct net *net,
1164				       struct sockaddr *sa, int salen,
1165				       int flags)
1166{
1167	return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1168}
1169
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1170static const struct svc_xprt_ops svc_tcp_ops = {
1171	.xpo_create = svc_tcp_create,
1172	.xpo_recvfrom = svc_tcp_recvfrom,
1173	.xpo_sendto = svc_tcp_sendto,
1174	.xpo_release_rqst = svc_release_skb,
1175	.xpo_detach = svc_tcp_sock_detach,
1176	.xpo_free = svc_sock_free,
 
1177	.xpo_has_wspace = svc_tcp_has_wspace,
1178	.xpo_accept = svc_tcp_accept,
1179	.xpo_secure_port = svc_sock_secure_port,
1180	.xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt,
1181};
1182
1183static struct svc_xprt_class svc_tcp_class = {
1184	.xcl_name = "tcp",
1185	.xcl_owner = THIS_MODULE,
1186	.xcl_ops = &svc_tcp_ops,
1187	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1188	.xcl_ident = XPRT_TRANSPORT_TCP,
1189};
1190
1191void svc_init_xprt_sock(void)
1192{
1193	svc_reg_xprt_class(&svc_tcp_class);
1194	svc_reg_xprt_class(&svc_udp_class);
 
1195}
1196
1197void svc_cleanup_xprt_sock(void)
1198{
1199	svc_unreg_xprt_class(&svc_tcp_class);
1200	svc_unreg_xprt_class(&svc_udp_class);
 
1201}
1202
1203static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1204{
1205	struct sock	*sk = svsk->sk_sk;
1206
1207	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
1208		      &svsk->sk_xprt, serv);
1209	set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
1210	set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
1211	if (sk->sk_state == TCP_LISTEN) {
1212		dprintk("setting up TCP socket for listening\n");
1213		strcpy(svsk->sk_xprt.xpt_remotebuf, "listener");
1214		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
1215		sk->sk_data_ready = svc_tcp_listen_data_ready;
1216		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
1217	} else {
1218		dprintk("setting up TCP socket for reading\n");
1219		sk->sk_state_change = svc_tcp_state_change;
1220		sk->sk_data_ready = svc_data_ready;
1221		sk->sk_write_space = svc_write_space;
1222
1223		svsk->sk_reclen = 0;
1224		svsk->sk_tcplen = 0;
1225		svsk->sk_datalen = 0;
1226		memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
1227
1228		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1229
1230		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
1231		switch (sk->sk_state) {
1232		case TCP_SYN_RECV:
1233		case TCP_ESTABLISHED:
1234			break;
1235		default:
1236			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1237		}
1238	}
1239}
1240
1241void svc_sock_update_bufs(struct svc_serv *serv)
1242{
1243	/*
1244	 * The number of server threads has changed. Update
1245	 * rcvbuf and sndbuf accordingly on all sockets
1246	 */
1247	struct svc_sock *svsk;
1248
1249	spin_lock_bh(&serv->sv_lock);
1250	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1251		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1252	spin_unlock_bh(&serv->sv_lock);
1253}
1254EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
1255
1256/*
1257 * Initialize socket for RPC use and create svc_sock struct
1258 */
1259static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1260						struct socket *sock,
1261						int flags)
1262{
1263	struct svc_sock	*svsk;
1264	struct sock	*inet;
1265	int		pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1266	int		err = 0;
1267
1268	dprintk("svc: svc_setup_socket %p\n", sock);
1269	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1270	if (!svsk)
1271		return ERR_PTR(-ENOMEM);
1272
1273	inet = sock->sk;
1274
1275	/* Register socket with portmapper */
1276	if (pmap_register)
1277		err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
1278				     inet->sk_protocol,
1279				     ntohs(inet_sk(inet)->inet_sport));
1280
1281	if (err < 0) {
1282		kfree(svsk);
1283		return ERR_PTR(err);
1284	}
1285
1286	svsk->sk_sock = sock;
1287	svsk->sk_sk = inet;
1288	svsk->sk_ostate = inet->sk_state_change;
1289	svsk->sk_odata = inet->sk_data_ready;
1290	svsk->sk_owspace = inet->sk_write_space;
1291	/*
1292	 * This barrier is necessary in order to prevent race condition
1293	 * with svc_data_ready(), svc_listen_data_ready() and others
1294	 * when calling callbacks above.
1295	 */
1296	wmb();
1297	inet->sk_user_data = svsk;
1298
1299	/* Initialize the socket */
1300	if (sock->type == SOCK_DGRAM)
1301		svc_udp_init(svsk, serv);
1302	else
1303		svc_tcp_init(svsk, serv);
1304
1305	dprintk("svc: svc_setup_socket created %p (inet %p), "
1306			"listen %d close %d\n",
1307			svsk, svsk->sk_sk,
1308			test_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags),
1309			test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
1310
1311	return svsk;
1312}
1313
1314bool svc_alien_sock(struct net *net, int fd)
1315{
1316	int err;
1317	struct socket *sock = sockfd_lookup(fd, &err);
1318	bool ret = false;
1319
1320	if (!sock)
1321		goto out;
1322	if (sock_net(sock->sk) != net)
1323		ret = true;
1324	sockfd_put(sock);
1325out:
1326	return ret;
1327}
1328EXPORT_SYMBOL_GPL(svc_alien_sock);
1329
1330/**
1331 * svc_addsock - add a listener socket to an RPC service
1332 * @serv: pointer to RPC service to which to add a new listener
1333 * @fd: file descriptor of the new listener
1334 * @name_return: pointer to buffer to fill in with name of listener
1335 * @len: size of the buffer
1336 * @cred: credential
1337 *
1338 * Fills in socket name and returns positive length of name if successful.
1339 * Name is terminated with '\n'.  On error, returns a negative errno
1340 * value.
1341 */
1342int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
1343		const size_t len, const struct cred *cred)
1344{
1345	int err = 0;
1346	struct socket *so = sockfd_lookup(fd, &err);
1347	struct svc_sock *svsk = NULL;
1348	struct sockaddr_storage addr;
1349	struct sockaddr *sin = (struct sockaddr *)&addr;
1350	int salen;
1351
1352	if (!so)
1353		return err;
1354	err = -EAFNOSUPPORT;
1355	if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1356		goto out;
1357	err =  -EPROTONOSUPPORT;
1358	if (so->sk->sk_protocol != IPPROTO_TCP &&
1359	    so->sk->sk_protocol != IPPROTO_UDP)
1360		goto out;
1361	err = -EISCONN;
1362	if (so->state > SS_UNCONNECTED)
1363		goto out;
1364	err = -ENOENT;
1365	if (!try_module_get(THIS_MODULE))
1366		goto out;
1367	svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
1368	if (IS_ERR(svsk)) {
1369		module_put(THIS_MODULE);
1370		err = PTR_ERR(svsk);
1371		goto out;
1372	}
1373	salen = kernel_getsockname(svsk->sk_sock, sin);
1374	if (salen >= 0)
1375		svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
1376	svsk->sk_xprt.xpt_cred = get_cred(cred);
1377	svc_add_new_perm_xprt(serv, &svsk->sk_xprt);
1378	return svc_one_sock_name(svsk, name_return, len);
1379out:
1380	sockfd_put(so);
1381	return err;
1382}
1383EXPORT_SYMBOL_GPL(svc_addsock);
1384
1385/*
1386 * Create socket for RPC service.
1387 */
1388static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1389					  int protocol,
1390					  struct net *net,
1391					  struct sockaddr *sin, int len,
1392					  int flags)
1393{
1394	struct svc_sock	*svsk;
1395	struct socket	*sock;
1396	int		error;
1397	int		type;
1398	struct sockaddr_storage addr;
1399	struct sockaddr *newsin = (struct sockaddr *)&addr;
1400	int		newlen;
1401	int		family;
1402	int		val;
1403	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1404
1405	dprintk("svc: svc_create_socket(%s, %d, %s)\n",
1406			serv->sv_program->pg_name, protocol,
1407			__svc_print_addr(sin, buf, sizeof(buf)));
1408
1409	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1410		printk(KERN_WARNING "svc: only UDP and TCP "
1411				"sockets supported\n");
1412		return ERR_PTR(-EINVAL);
1413	}
1414
1415	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1416	switch (sin->sa_family) {
1417	case AF_INET6:
1418		family = PF_INET6;
1419		break;
1420	case AF_INET:
1421		family = PF_INET;
1422		break;
1423	default:
1424		return ERR_PTR(-EINVAL);
1425	}
1426
1427	error = __sock_create(net, family, type, protocol, &sock, 1);
1428	if (error < 0)
1429		return ERR_PTR(error);
1430
1431	svc_reclassify_socket(sock);
1432
1433	/*
1434	 * If this is an PF_INET6 listener, we want to avoid
1435	 * getting requests from IPv4 remotes.  Those should
1436	 * be shunted to a PF_INET listener via rpcbind.
1437	 */
1438	val = 1;
1439	if (family == PF_INET6)
1440		kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
1441					(char *)&val, sizeof(val));
1442
1443	if (type == SOCK_STREAM)
1444		sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
1445	error = kernel_bind(sock, sin, len);
1446	if (error < 0)
1447		goto bummer;
1448
1449	error = kernel_getsockname(sock, newsin);
1450	if (error < 0)
1451		goto bummer;
1452	newlen = error;
1453
1454	if (protocol == IPPROTO_TCP) {
1455		if ((error = kernel_listen(sock, 64)) < 0)
1456			goto bummer;
1457	}
1458
1459	svsk = svc_setup_socket(serv, sock, flags);
1460	if (IS_ERR(svsk)) {
1461		error = PTR_ERR(svsk);
1462		goto bummer;
1463	}
1464	svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
1465	return (struct svc_xprt *)svsk;
1466bummer:
1467	dprintk("svc: svc_create_socket error = %d\n", -error);
1468	sock_release(sock);
1469	return ERR_PTR(error);
1470}
1471
1472/*
1473 * Detach the svc_sock from the socket so that no
1474 * more callbacks occur.
1475 */
1476static void svc_sock_detach(struct svc_xprt *xprt)
1477{
1478	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1479	struct sock *sk = svsk->sk_sk;
1480
1481	dprintk("svc: svc_sock_detach(%p)\n", svsk);
1482
1483	/* put back the old socket callbacks */
1484	lock_sock(sk);
1485	sk->sk_state_change = svsk->sk_ostate;
1486	sk->sk_data_ready = svsk->sk_odata;
1487	sk->sk_write_space = svsk->sk_owspace;
1488	sk->sk_user_data = NULL;
1489	release_sock(sk);
1490}
1491
1492/*
1493 * Disconnect the socket, and reset the callbacks
1494 */
1495static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1496{
1497	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1498
1499	dprintk("svc: svc_tcp_sock_detach(%p)\n", svsk);
1500
1501	svc_sock_detach(xprt);
1502
1503	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
1504		svc_tcp_clear_pages(svsk);
1505		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
1506	}
1507}
1508
1509/*
1510 * Free the svc_sock's socket resources and the svc_sock itself.
1511 */
1512static void svc_sock_free(struct svc_xprt *xprt)
1513{
1514	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1515	dprintk("svc: svc_sock_free(%p)\n", svsk);
1516
1517	if (svsk->sk_sock->file)
1518		sockfd_put(svsk->sk_sock);
1519	else
1520		sock_release(svsk->sk_sock);
1521	kfree(svsk);
1522}
v4.17
 
   1/*
   2 * linux/net/sunrpc/svcsock.c
   3 *
   4 * These are the RPC server socket internals.
   5 *
   6 * The server scheduling algorithm does not always distribute the load
   7 * evenly when servicing a single client. May need to modify the
   8 * svc_xprt_enqueue procedure...
   9 *
  10 * TCP support is largely untested and may be a little slow. The problem
  11 * is that we currently do two separate recvfrom's, one for the 4-byte
  12 * record length, and the second for the actual record. This could possibly
  13 * be improved by always reading a minimum size of around 100 bytes and
  14 * tucking any superfluous bytes away in a temporary store. Still, that
  15 * leaves write requests out in the rain. An alternative may be to peek at
  16 * the first skb in the queue, and if it matches the next TCP sequence
  17 * number, to extract the record marker. Yuck.
  18 *
  19 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  20 */
  21
  22#include <linux/kernel.h>
  23#include <linux/sched.h>
  24#include <linux/module.h>
  25#include <linux/errno.h>
  26#include <linux/fcntl.h>
  27#include <linux/net.h>
  28#include <linux/in.h>
  29#include <linux/inet.h>
  30#include <linux/udp.h>
  31#include <linux/tcp.h>
  32#include <linux/unistd.h>
  33#include <linux/slab.h>
  34#include <linux/netdevice.h>
  35#include <linux/skbuff.h>
  36#include <linux/file.h>
  37#include <linux/freezer.h>
  38#include <net/sock.h>
  39#include <net/checksum.h>
  40#include <net/ip.h>
  41#include <net/ipv6.h>
  42#include <net/udp.h>
  43#include <net/tcp.h>
  44#include <net/tcp_states.h>
  45#include <linux/uaccess.h>
  46#include <asm/ioctls.h>
  47#include <trace/events/skb.h>
  48
  49#include <linux/sunrpc/types.h>
  50#include <linux/sunrpc/clnt.h>
  51#include <linux/sunrpc/xdr.h>
  52#include <linux/sunrpc/msg_prot.h>
  53#include <linux/sunrpc/svcsock.h>
  54#include <linux/sunrpc/stats.h>
  55#include <linux/sunrpc/xprt.h>
  56
  57#include "sunrpc.h"
  58
  59#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
  60
  61
  62static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
  63					 int flags);
  64static int		svc_udp_recvfrom(struct svc_rqst *);
  65static int		svc_udp_sendto(struct svc_rqst *);
  66static void		svc_sock_detach(struct svc_xprt *);
  67static void		svc_tcp_sock_detach(struct svc_xprt *);
  68static void		svc_sock_free(struct svc_xprt *);
  69
  70static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
  71					  struct net *, struct sockaddr *,
  72					  int, int);
  73#if defined(CONFIG_SUNRPC_BACKCHANNEL)
  74static struct svc_xprt *svc_bc_create_socket(struct svc_serv *, int,
  75					     struct net *, struct sockaddr *,
  76					     int, int);
  77static void svc_bc_sock_free(struct svc_xprt *xprt);
  78#endif /* CONFIG_SUNRPC_BACKCHANNEL */
  79
  80#ifdef CONFIG_DEBUG_LOCK_ALLOC
  81static struct lock_class_key svc_key[2];
  82static struct lock_class_key svc_slock_key[2];
  83
  84static void svc_reclassify_socket(struct socket *sock)
  85{
  86	struct sock *sk = sock->sk;
  87
  88	if (WARN_ON_ONCE(!sock_allow_reclassification(sk)))
  89		return;
  90
  91	switch (sk->sk_family) {
  92	case AF_INET:
  93		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
  94					      &svc_slock_key[0],
  95					      "sk_xprt.xpt_lock-AF_INET-NFSD",
  96					      &svc_key[0]);
  97		break;
  98
  99	case AF_INET6:
 100		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
 101					      &svc_slock_key[1],
 102					      "sk_xprt.xpt_lock-AF_INET6-NFSD",
 103					      &svc_key[1]);
 104		break;
 105
 106	default:
 107		BUG();
 108	}
 109}
 110#else
 111static void svc_reclassify_socket(struct socket *sock)
 112{
 113}
 114#endif
 115
 116/*
 117 * Release an skbuff after use
 118 */
 119static void svc_release_skb(struct svc_rqst *rqstp)
 120{
 121	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
 122
 123	if (skb) {
 124		struct svc_sock *svsk =
 125			container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 126		rqstp->rq_xprt_ctxt = NULL;
 127
 128		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
 129		skb_free_datagram_locked(svsk->sk_sk, skb);
 130	}
 131}
 132
 133static void svc_release_udp_skb(struct svc_rqst *rqstp)
 134{
 135	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
 136
 137	if (skb) {
 138		rqstp->rq_xprt_ctxt = NULL;
 139
 140		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
 141		consume_skb(skb);
 142	}
 143}
 144
 145union svc_pktinfo_u {
 146	struct in_pktinfo pkti;
 147	struct in6_pktinfo pkti6;
 148};
 149#define SVC_PKTINFO_SPACE \
 150	CMSG_SPACE(sizeof(union svc_pktinfo_u))
 151
 152static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
 153{
 154	struct svc_sock *svsk =
 155		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 156	switch (svsk->sk_sk->sk_family) {
 157	case AF_INET: {
 158			struct in_pktinfo *pki = CMSG_DATA(cmh);
 159
 160			cmh->cmsg_level = SOL_IP;
 161			cmh->cmsg_type = IP_PKTINFO;
 162			pki->ipi_ifindex = 0;
 163			pki->ipi_spec_dst.s_addr =
 164				 svc_daddr_in(rqstp)->sin_addr.s_addr;
 165			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 166		}
 167		break;
 168
 169	case AF_INET6: {
 170			struct in6_pktinfo *pki = CMSG_DATA(cmh);
 171			struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 172
 173			cmh->cmsg_level = SOL_IPV6;
 174			cmh->cmsg_type = IPV6_PKTINFO;
 175			pki->ipi6_ifindex = daddr->sin6_scope_id;
 176			pki->ipi6_addr = daddr->sin6_addr;
 177			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 178		}
 179		break;
 180	}
 181}
 182
 183/*
 184 * send routine intended to be shared by the fore- and back-channel
 185 */
 186int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
 187		    struct page *headpage, unsigned long headoffset,
 188		    struct page *tailpage, unsigned long tailoffset)
 189{
 190	int		result;
 191	int		size;
 192	struct page	**ppage = xdr->pages;
 193	size_t		base = xdr->page_base;
 194	unsigned int	pglen = xdr->page_len;
 195	unsigned int	flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
 196	int		slen;
 197	int		len = 0;
 198
 199	slen = xdr->len;
 200
 201	/* send head */
 202	if (slen == xdr->head[0].iov_len)
 203		flags = 0;
 204	len = kernel_sendpage(sock, headpage, headoffset,
 205				  xdr->head[0].iov_len, flags);
 206	if (len != xdr->head[0].iov_len)
 207		goto out;
 208	slen -= xdr->head[0].iov_len;
 209	if (slen == 0)
 210		goto out;
 211
 212	/* send page data */
 213	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
 214	while (pglen > 0) {
 215		if (slen == size)
 216			flags = 0;
 217		result = kernel_sendpage(sock, *ppage, base, size, flags);
 218		if (result > 0)
 219			len += result;
 220		if (result != size)
 221			goto out;
 222		slen -= size;
 223		pglen -= size;
 224		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
 225		base = 0;
 226		ppage++;
 227	}
 228
 229	/* send tail */
 230	if (xdr->tail[0].iov_len) {
 231		result = kernel_sendpage(sock, tailpage, tailoffset,
 232				   xdr->tail[0].iov_len, 0);
 233		if (result > 0)
 234			len += result;
 235	}
 236
 237out:
 238	return len;
 239}
 240
 241
 242/*
 243 * Generic sendto routine
 244 */
 245static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
 246{
 247	struct svc_sock	*svsk =
 248		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 249	struct socket	*sock = svsk->sk_sock;
 250	union {
 251		struct cmsghdr	hdr;
 252		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 253	} buffer;
 254	struct cmsghdr *cmh = &buffer.hdr;
 255	int		len = 0;
 256	unsigned long tailoff;
 257	unsigned long headoff;
 258	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 259
 260	if (rqstp->rq_prot == IPPROTO_UDP) {
 261		struct msghdr msg = {
 262			.msg_name	= &rqstp->rq_addr,
 263			.msg_namelen	= rqstp->rq_addrlen,
 264			.msg_control	= cmh,
 265			.msg_controllen	= sizeof(buffer),
 266			.msg_flags	= MSG_MORE,
 267		};
 268
 269		svc_set_cmsg_data(rqstp, cmh);
 270
 271		if (sock_sendmsg(sock, &msg) < 0)
 272			goto out;
 273	}
 274
 275	tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
 276	headoff = 0;
 277	len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
 278			       rqstp->rq_respages[0], tailoff);
 279
 280out:
 281	dprintk("svc: socket %p sendto([%p %zu... ], %d) = %d (addr %s)\n",
 282		svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
 283		xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
 284
 285	return len;
 286}
 287
 288/*
 289 * Report socket names for nfsdfs
 290 */
 291static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
 292{
 293	const struct sock *sk = svsk->sk_sk;
 294	const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
 295							"udp" : "tcp";
 296	int len;
 297
 298	switch (sk->sk_family) {
 299	case PF_INET:
 300		len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
 301				proto_name,
 302				&inet_sk(sk)->inet_rcv_saddr,
 303				inet_sk(sk)->inet_num);
 304		break;
 305#if IS_ENABLED(CONFIG_IPV6)
 306	case PF_INET6:
 307		len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
 308				proto_name,
 309				&sk->sk_v6_rcv_saddr,
 310				inet_sk(sk)->inet_num);
 311		break;
 312#endif
 313	default:
 314		len = snprintf(buf, remaining, "*unknown-%d*\n",
 315				sk->sk_family);
 316	}
 317
 318	if (len >= remaining) {
 319		*buf = '\0';
 320		return -ENAMETOOLONG;
 321	}
 322	return len;
 323}
 324
 325/*
 326 * Generic recvfrom routine.
 327 */
 328static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
 329			int buflen)
 330{
 331	struct svc_sock *svsk =
 332		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 333	struct msghdr msg = {
 334		.msg_flags	= MSG_DONTWAIT,
 335	};
 336	int len;
 337
 338	rqstp->rq_xprt_hlen = 0;
 339
 340	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 341	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, iov, nr, buflen);
 342	len = sock_recvmsg(svsk->sk_sock, &msg, msg.msg_flags);
 
 
 
 
 343	/* If we read a full record, then assume there may be more
 344	 * data to read (stream based sockets only!)
 345	 */
 346	if (len == buflen)
 347		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 348
 349	dprintk("svc: socket %p recvfrom(%p, %zu) = %d\n",
 350		svsk, iov[0].iov_base, iov[0].iov_len, len);
 351	return len;
 352}
 353
 354static int svc_partial_recvfrom(struct svc_rqst *rqstp,
 355				struct kvec *iov, int nr,
 356				int buflen, unsigned int base)
 357{
 358	size_t save_iovlen;
 359	void *save_iovbase;
 360	unsigned int i;
 361	int ret;
 362
 363	if (base == 0)
 364		return svc_recvfrom(rqstp, iov, nr, buflen);
 365
 366	for (i = 0; i < nr; i++) {
 367		if (iov[i].iov_len > base)
 368			break;
 369		base -= iov[i].iov_len;
 370	}
 371	save_iovlen = iov[i].iov_len;
 372	save_iovbase = iov[i].iov_base;
 373	iov[i].iov_len -= base;
 374	iov[i].iov_base += base;
 375	ret = svc_recvfrom(rqstp, &iov[i], nr - i, buflen);
 376	iov[i].iov_len = save_iovlen;
 377	iov[i].iov_base = save_iovbase;
 378	return ret;
 379}
 380
 381/*
 382 * Set socket snd and rcv buffer lengths
 383 */
 384static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
 385				unsigned int rcv)
 386{
 
 
 
 
 
 387	lock_sock(sock->sk);
 388	sock->sk->sk_sndbuf = snd * 2;
 389	sock->sk->sk_rcvbuf = rcv * 2;
 390	sock->sk->sk_write_space(sock->sk);
 391	release_sock(sock->sk);
 392}
 393
 394static void svc_sock_secure_port(struct svc_rqst *rqstp)
 395{
 396	if (svc_port_is_privileged(svc_addr(rqstp)))
 397		set_bit(RQ_SECURE, &rqstp->rq_flags);
 398	else
 399		clear_bit(RQ_SECURE, &rqstp->rq_flags);
 400}
 401
 402/*
 403 * INET callback when data has been received on the socket.
 404 */
 405static void svc_data_ready(struct sock *sk)
 406{
 407	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 408
 409	if (svsk) {
 410		dprintk("svc: socket %p(inet %p), busy=%d\n",
 411			svsk, sk,
 412			test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
 413
 414		/* Refer to svc_setup_socket() for details. */
 415		rmb();
 416		svsk->sk_odata(sk);
 417		if (!test_and_set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags))
 418			svc_xprt_enqueue(&svsk->sk_xprt);
 419	}
 420}
 421
 422/*
 423 * INET callback when space is newly available on the socket.
 424 */
 425static void svc_write_space(struct sock *sk)
 426{
 427	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
 428
 429	if (svsk) {
 430		dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
 431			svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
 432
 433		/* Refer to svc_setup_socket() for details. */
 434		rmb();
 435		svsk->sk_owspace(sk);
 436		svc_xprt_enqueue(&svsk->sk_xprt);
 437	}
 438}
 439
 440static int svc_tcp_has_wspace(struct svc_xprt *xprt)
 441{
 442	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 443
 444	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
 445		return 1;
 446	return !test_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 447}
 448
 449static void svc_tcp_kill_temp_xprt(struct svc_xprt *xprt)
 450{
 451	struct svc_sock *svsk;
 452	struct socket *sock;
 453	struct linger no_linger = {
 454		.l_onoff = 1,
 455		.l_linger = 0,
 456	};
 457
 458	svsk = container_of(xprt, struct svc_sock, sk_xprt);
 459	sock = svsk->sk_sock;
 460	kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
 461			  (char *)&no_linger, sizeof(no_linger));
 462}
 463
 464/*
 465 * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
 466 */
 467static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
 468				     struct cmsghdr *cmh)
 469{
 470	struct in_pktinfo *pki = CMSG_DATA(cmh);
 471	struct sockaddr_in *daddr = svc_daddr_in(rqstp);
 472
 473	if (cmh->cmsg_type != IP_PKTINFO)
 474		return 0;
 475
 476	daddr->sin_family = AF_INET;
 477	daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
 478	return 1;
 479}
 480
 481/*
 482 * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
 483 */
 484static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
 485				     struct cmsghdr *cmh)
 486{
 487	struct in6_pktinfo *pki = CMSG_DATA(cmh);
 488	struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 489
 490	if (cmh->cmsg_type != IPV6_PKTINFO)
 491		return 0;
 492
 493	daddr->sin6_family = AF_INET6;
 494	daddr->sin6_addr = pki->ipi6_addr;
 495	daddr->sin6_scope_id = pki->ipi6_ifindex;
 496	return 1;
 497}
 498
 499/*
 500 * Copy the UDP datagram's destination address to the rqstp structure.
 501 * The 'destination' address in this case is the address to which the
 502 * peer sent the datagram, i.e. our local address. For multihomed
 503 * hosts, this can change from msg to msg. Note that only the IP
 504 * address changes, the port number should remain the same.
 505 */
 506static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
 507				    struct cmsghdr *cmh)
 508{
 509	switch (cmh->cmsg_level) {
 510	case SOL_IP:
 511		return svc_udp_get_dest_address4(rqstp, cmh);
 512	case SOL_IPV6:
 513		return svc_udp_get_dest_address6(rqstp, cmh);
 514	}
 515
 516	return 0;
 517}
 518
 519/*
 520 * Receive a datagram from a UDP socket.
 521 */
 522static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 523{
 524	struct svc_sock	*svsk =
 525		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 526	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 527	struct sk_buff	*skb;
 528	union {
 529		struct cmsghdr	hdr;
 530		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 531	} buffer;
 532	struct cmsghdr *cmh = &buffer.hdr;
 533	struct msghdr msg = {
 534		.msg_name = svc_addr(rqstp),
 535		.msg_control = cmh,
 536		.msg_controllen = sizeof(buffer),
 537		.msg_flags = MSG_DONTWAIT,
 538	};
 539	size_t len;
 540	int err;
 541
 542	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
 543	    /* udp sockets need large rcvbuf as all pending
 544	     * requests are still in that buffer.  sndbuf must
 545	     * also be large enough that there is enough space
 546	     * for one reply per thread.  We count all threads
 547	     * rather than threads in a particular pool, which
 548	     * provides an upper bound on the number of threads
 549	     * which will access the socket.
 550	     */
 551	    svc_sock_setbufsize(svsk->sk_sock,
 552				(serv->sv_nrthreads+3) * serv->sv_max_mesg,
 553				(serv->sv_nrthreads+3) * serv->sv_max_mesg);
 554
 555	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 556	skb = NULL;
 557	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
 558			     0, 0, MSG_PEEK | MSG_DONTWAIT);
 559	if (err >= 0)
 560		skb = skb_recv_udp(svsk->sk_sk, 0, 1, &err);
 561
 562	if (skb == NULL) {
 563		if (err != -EAGAIN) {
 564			/* possibly an icmp error */
 565			dprintk("svc: recvfrom returned error %d\n", -err);
 566			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 567		}
 568		return 0;
 569	}
 570	len = svc_addr_len(svc_addr(rqstp));
 571	rqstp->rq_addrlen = len;
 572	if (skb->tstamp == 0) {
 573		skb->tstamp = ktime_get_real();
 574		/* Don't enable netstamp, sunrpc doesn't
 575		   need that much accuracy */
 576	}
 577	svsk->sk_sk->sk_stamp = skb->tstamp;
 578	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
 579
 580	len  = skb->len;
 581	rqstp->rq_arg.len = len;
 582
 583	rqstp->rq_prot = IPPROTO_UDP;
 584
 585	if (!svc_udp_get_dest_address(rqstp, cmh)) {
 586		net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
 587				     cmh->cmsg_level, cmh->cmsg_type);
 588		goto out_free;
 589	}
 590	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
 591
 592	if (skb_is_nonlinear(skb)) {
 593		/* we have to copy */
 594		local_bh_disable();
 595		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
 596			local_bh_enable();
 597			/* checksum error */
 598			goto out_free;
 599		}
 600		local_bh_enable();
 601		consume_skb(skb);
 602	} else {
 603		/* we can use it in-place */
 604		rqstp->rq_arg.head[0].iov_base = skb->data;
 605		rqstp->rq_arg.head[0].iov_len = len;
 606		if (skb_checksum_complete(skb))
 607			goto out_free;
 608		rqstp->rq_xprt_ctxt = skb;
 609	}
 610
 611	rqstp->rq_arg.page_base = 0;
 612	if (len <= rqstp->rq_arg.head[0].iov_len) {
 613		rqstp->rq_arg.head[0].iov_len = len;
 614		rqstp->rq_arg.page_len = 0;
 615		rqstp->rq_respages = rqstp->rq_pages+1;
 616	} else {
 617		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
 618		rqstp->rq_respages = rqstp->rq_pages + 1 +
 619			DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
 620	}
 621	rqstp->rq_next_page = rqstp->rq_respages+1;
 622
 623	if (serv->sv_stats)
 624		serv->sv_stats->netudpcnt++;
 625
 626	return len;
 627out_free:
 628	kfree_skb(skb);
 629	return 0;
 630}
 631
 632static int
 633svc_udp_sendto(struct svc_rqst *rqstp)
 634{
 635	int		error;
 636
 637	error = svc_sendto(rqstp, &rqstp->rq_res);
 638	if (error == -ECONNREFUSED)
 639		/* ICMP error on earlier request. */
 640		error = svc_sendto(rqstp, &rqstp->rq_res);
 641
 642	return error;
 643}
 644
 645static void svc_udp_prep_reply_hdr(struct svc_rqst *rqstp)
 646{
 647}
 648
 649static int svc_udp_has_wspace(struct svc_xprt *xprt)
 650{
 651	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 652	struct svc_serv	*serv = xprt->xpt_server;
 653	unsigned long required;
 654
 655	/*
 656	 * Set the SOCK_NOSPACE flag before checking the available
 657	 * sock space.
 658	 */
 659	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 660	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
 661	if (required*2 > sock_wspace(svsk->sk_sk))
 662		return 0;
 663	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 664	return 1;
 665}
 666
 667static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
 668{
 669	BUG();
 670	return NULL;
 671}
 672
 673static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt)
 674{
 675}
 676
 677static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
 678				       struct net *net,
 679				       struct sockaddr *sa, int salen,
 680				       int flags)
 681{
 682	return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
 683}
 684
 685static const struct svc_xprt_ops svc_udp_ops = {
 686	.xpo_create = svc_udp_create,
 687	.xpo_recvfrom = svc_udp_recvfrom,
 688	.xpo_sendto = svc_udp_sendto,
 689	.xpo_release_rqst = svc_release_udp_skb,
 690	.xpo_detach = svc_sock_detach,
 691	.xpo_free = svc_sock_free,
 692	.xpo_prep_reply_hdr = svc_udp_prep_reply_hdr,
 693	.xpo_has_wspace = svc_udp_has_wspace,
 694	.xpo_accept = svc_udp_accept,
 695	.xpo_secure_port = svc_sock_secure_port,
 696	.xpo_kill_temp_xprt = svc_udp_kill_temp_xprt,
 697};
 698
 699static struct svc_xprt_class svc_udp_class = {
 700	.xcl_name = "udp",
 701	.xcl_owner = THIS_MODULE,
 702	.xcl_ops = &svc_udp_ops,
 703	.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
 704	.xcl_ident = XPRT_TRANSPORT_UDP,
 705};
 706
 707static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
 708{
 709	int err, level, optname, one = 1;
 710
 711	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class,
 712		      &svsk->sk_xprt, serv);
 713	clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
 714	svsk->sk_sk->sk_data_ready = svc_data_ready;
 715	svsk->sk_sk->sk_write_space = svc_write_space;
 716
 717	/* initialise setting must have enough space to
 718	 * receive and respond to one request.
 719	 * svc_udp_recvfrom will re-adjust if necessary
 720	 */
 721	svc_sock_setbufsize(svsk->sk_sock,
 722			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
 723			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
 724
 725	/* data might have come in before data_ready set up */
 726	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 727	set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
 728
 729	/* make sure we get destination address info */
 730	switch (svsk->sk_sk->sk_family) {
 731	case AF_INET:
 732		level = SOL_IP;
 733		optname = IP_PKTINFO;
 734		break;
 735	case AF_INET6:
 736		level = SOL_IPV6;
 737		optname = IPV6_RECVPKTINFO;
 738		break;
 739	default:
 740		BUG();
 741	}
 742	err = kernel_setsockopt(svsk->sk_sock, level, optname,
 743					(char *)&one, sizeof(one));
 744	dprintk("svc: kernel_setsockopt returned %d\n", err);
 745}
 746
 747/*
 748 * A data_ready event on a listening socket means there's a connection
 749 * pending. Do not use state_change as a substitute for it.
 750 */
 751static void svc_tcp_listen_data_ready(struct sock *sk)
 752{
 753	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 754
 755	dprintk("svc: socket %p TCP (listen) state change %d\n",
 756		sk, sk->sk_state);
 757
 758	if (svsk) {
 759		/* Refer to svc_setup_socket() for details. */
 760		rmb();
 761		svsk->sk_odata(sk);
 762	}
 763
 764	/*
 765	 * This callback may called twice when a new connection
 766	 * is established as a child socket inherits everything
 767	 * from a parent LISTEN socket.
 768	 * 1) data_ready method of the parent socket will be called
 769	 *    when one of child sockets become ESTABLISHED.
 770	 * 2) data_ready method of the child socket may be called
 771	 *    when it receives data before the socket is accepted.
 772	 * In case of 2, we should ignore it silently.
 773	 */
 774	if (sk->sk_state == TCP_LISTEN) {
 775		if (svsk) {
 776			set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 777			svc_xprt_enqueue(&svsk->sk_xprt);
 778		} else
 779			printk("svc: socket %p: no user data\n", sk);
 780	}
 781}
 782
 783/*
 784 * A state change on a connected socket means it's dying or dead.
 785 */
 786static void svc_tcp_state_change(struct sock *sk)
 787{
 788	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 789
 790	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
 791		sk, sk->sk_state, sk->sk_user_data);
 792
 793	if (!svsk)
 794		printk("svc: socket %p: no user data\n", sk);
 795	else {
 796		/* Refer to svc_setup_socket() for details. */
 797		rmb();
 798		svsk->sk_ostate(sk);
 799		if (sk->sk_state != TCP_ESTABLISHED) {
 800			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 801			svc_xprt_enqueue(&svsk->sk_xprt);
 802		}
 803	}
 804}
 805
 806/*
 807 * Accept a TCP connection
 808 */
 809static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
 810{
 811	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 812	struct sockaddr_storage addr;
 813	struct sockaddr	*sin = (struct sockaddr *) &addr;
 814	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 815	struct socket	*sock = svsk->sk_sock;
 816	struct socket	*newsock;
 817	struct svc_sock	*newsvsk;
 818	int		err, slen;
 819	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 820
 821	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
 822	if (!sock)
 823		return NULL;
 824
 825	clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 826	err = kernel_accept(sock, &newsock, O_NONBLOCK);
 827	if (err < 0) {
 828		if (err == -ENOMEM)
 829			printk(KERN_WARNING "%s: no more sockets!\n",
 830			       serv->sv_name);
 831		else if (err != -EAGAIN)
 832			net_warn_ratelimited("%s: accept failed (err %d)!\n",
 833					     serv->sv_name, -err);
 834		return NULL;
 835	}
 836	set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 837
 838	err = kernel_getpeername(newsock, sin);
 839	if (err < 0) {
 840		net_warn_ratelimited("%s: peername failed (err %d)!\n",
 841				     serv->sv_name, -err);
 842		goto failed;		/* aborted connection or whatever */
 843	}
 844	slen = err;
 845
 846	/* Ideally, we would want to reject connections from unauthorized
 847	 * hosts here, but when we get encryption, the IP of the host won't
 848	 * tell us anything.  For now just warn about unpriv connections.
 849	 */
 850	if (!svc_port_is_privileged(sin)) {
 851		dprintk("%s: connect from unprivileged port: %s\n",
 852			serv->sv_name,
 853			__svc_print_addr(sin, buf, sizeof(buf)));
 854	}
 855	dprintk("%s: connect from %s\n", serv->sv_name,
 856		__svc_print_addr(sin, buf, sizeof(buf)));
 857
 858	/* Reset the inherited callbacks before calling svc_setup_socket */
 859	newsock->sk->sk_state_change = svsk->sk_ostate;
 860	newsock->sk->sk_data_ready = svsk->sk_odata;
 861	newsock->sk->sk_write_space = svsk->sk_owspace;
 862
 863	/* make sure that a write doesn't block forever when
 864	 * low on memory
 865	 */
 866	newsock->sk->sk_sndtimeo = HZ*30;
 867
 868	newsvsk = svc_setup_socket(serv, newsock,
 869				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
 870	if (IS_ERR(newsvsk))
 871		goto failed;
 872	svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
 873	err = kernel_getsockname(newsock, sin);
 874	slen = err;
 875	if (unlikely(err < 0)) {
 876		dprintk("svc_tcp_accept: kernel_getsockname error %d\n", -err);
 877		slen = offsetof(struct sockaddr, sa_data);
 878	}
 879	svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
 880
 881	if (sock_is_loopback(newsock->sk))
 882		set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 883	else
 884		clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 885	if (serv->sv_stats)
 886		serv->sv_stats->nettcpconn++;
 887
 888	return &newsvsk->sk_xprt;
 889
 890failed:
 891	sock_release(newsock);
 892	return NULL;
 893}
 894
 895static unsigned int svc_tcp_restore_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 896{
 897	unsigned int i, len, npages;
 898
 899	if (svsk->sk_datalen == 0)
 900		return 0;
 901	len = svsk->sk_datalen;
 902	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 903	for (i = 0; i < npages; i++) {
 904		if (rqstp->rq_pages[i] != NULL)
 905			put_page(rqstp->rq_pages[i]);
 906		BUG_ON(svsk->sk_pages[i] == NULL);
 907		rqstp->rq_pages[i] = svsk->sk_pages[i];
 908		svsk->sk_pages[i] = NULL;
 909	}
 910	rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
 911	return len;
 912}
 913
 914static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 915{
 916	unsigned int i, len, npages;
 917
 918	if (svsk->sk_datalen == 0)
 919		return;
 920	len = svsk->sk_datalen;
 921	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 922	for (i = 0; i < npages; i++) {
 923		svsk->sk_pages[i] = rqstp->rq_pages[i];
 924		rqstp->rq_pages[i] = NULL;
 925	}
 926}
 927
 928static void svc_tcp_clear_pages(struct svc_sock *svsk)
 929{
 930	unsigned int i, len, npages;
 931
 932	if (svsk->sk_datalen == 0)
 933		goto out;
 934	len = svsk->sk_datalen;
 935	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 936	for (i = 0; i < npages; i++) {
 937		if (svsk->sk_pages[i] == NULL) {
 938			WARN_ON_ONCE(1);
 939			continue;
 940		}
 941		put_page(svsk->sk_pages[i]);
 942		svsk->sk_pages[i] = NULL;
 943	}
 944out:
 945	svsk->sk_tcplen = 0;
 946	svsk->sk_datalen = 0;
 947}
 948
 949/*
 950 * Receive fragment record header.
 951 * If we haven't gotten the record length yet, get the next four bytes.
 952 */
 953static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
 954{
 955	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 956	unsigned int want;
 957	int len;
 958
 959	if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
 960		struct kvec	iov;
 961
 962		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
 963		iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
 964		iov.iov_len  = want;
 965		if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
 
 966			goto error;
 967		svsk->sk_tcplen += len;
 968
 969		if (len < want) {
 970			dprintk("svc: short recvfrom while reading record "
 971				"length (%d of %d)\n", len, want);
 972			return -EAGAIN;
 973		}
 974
 975		dprintk("svc: TCP record, %d bytes\n", svc_sock_reclen(svsk));
 976		if (svc_sock_reclen(svsk) + svsk->sk_datalen >
 977							serv->sv_max_mesg) {
 978			net_notice_ratelimited("RPC: fragment too large: %d\n",
 979					svc_sock_reclen(svsk));
 980			goto err_delete;
 981		}
 982	}
 983
 984	return svc_sock_reclen(svsk);
 985error:
 986	dprintk("RPC: TCP recv_record got %d\n", len);
 987	return len;
 988err_delete:
 989	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 990	return -EAGAIN;
 991}
 992
 993static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
 994{
 995	struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
 996	struct rpc_rqst *req = NULL;
 997	struct kvec *src, *dst;
 998	__be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
 999	__be32 xid;
1000	__be32 calldir;
1001
1002	xid = *p++;
1003	calldir = *p;
1004
1005	if (!bc_xprt)
1006		return -EAGAIN;
1007	spin_lock(&bc_xprt->recv_lock);
1008	req = xprt_lookup_rqst(bc_xprt, xid);
1009	if (!req)
1010		goto unlock_notfound;
1011
1012	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
1013	/*
1014	 * XXX!: cheating for now!  Only copying HEAD.
1015	 * But we know this is good enough for now (in fact, for any
1016	 * callback reply in the forseeable future).
1017	 */
1018	dst = &req->rq_private_buf.head[0];
1019	src = &rqstp->rq_arg.head[0];
1020	if (dst->iov_len < src->iov_len)
1021		goto unlock_eagain; /* whatever; just giving up. */
1022	memcpy(dst->iov_base, src->iov_base, src->iov_len);
1023	xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
1024	rqstp->rq_arg.len = 0;
1025	spin_unlock(&bc_xprt->recv_lock);
1026	return 0;
1027unlock_notfound:
1028	printk(KERN_NOTICE
1029		"%s: Got unrecognized reply: "
1030		"calldir 0x%x xpt_bc_xprt %p xid %08x\n",
1031		__func__, ntohl(calldir),
1032		bc_xprt, ntohl(xid));
1033unlock_eagain:
1034	spin_unlock(&bc_xprt->recv_lock);
1035	return -EAGAIN;
1036}
1037
1038static int copy_pages_to_kvecs(struct kvec *vec, struct page **pages, int len)
1039{
1040	int i = 0;
1041	int t = 0;
1042
1043	while (t < len) {
1044		vec[i].iov_base = page_address(pages[i]);
1045		vec[i].iov_len = PAGE_SIZE;
1046		i++;
1047		t += PAGE_SIZE;
1048	}
1049	return i;
1050}
1051
1052static void svc_tcp_fragment_received(struct svc_sock *svsk)
1053{
1054	/* If we have more data, signal svc_xprt_enqueue() to try again */
1055	dprintk("svc: TCP %s record (%d bytes)\n",
1056		svc_sock_final_rec(svsk) ? "final" : "nonfinal",
1057		svc_sock_reclen(svsk));
1058	svsk->sk_tcplen = 0;
1059	svsk->sk_reclen = 0;
1060}
1061
1062/*
1063 * Receive data from a TCP socket.
1064 */
1065static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
1066{
1067	struct svc_sock	*svsk =
1068		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
1069	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
1070	int		len;
1071	struct kvec *vec;
1072	unsigned int want, base;
1073	__be32 *p;
1074	__be32 calldir;
1075	int pnum;
1076
1077	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
1078		svsk, test_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags),
1079		test_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags),
1080		test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
1081
1082	len = svc_tcp_recv_record(svsk, rqstp);
1083	if (len < 0)
1084		goto error;
1085
1086	base = svc_tcp_restore_pages(svsk, rqstp);
1087	want = svc_sock_reclen(svsk) - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
1088
1089	vec = rqstp->rq_vec;
1090
1091	pnum = copy_pages_to_kvecs(&vec[0], &rqstp->rq_pages[0],
1092						svsk->sk_datalen + want);
1093
1094	rqstp->rq_respages = &rqstp->rq_pages[pnum];
1095	rqstp->rq_next_page = rqstp->rq_respages + 1;
1096
1097	/* Now receive data */
1098	len = svc_partial_recvfrom(rqstp, vec, pnum, want, base);
1099	if (len >= 0) {
1100		svsk->sk_tcplen += len;
1101		svsk->sk_datalen += len;
1102	}
1103	if (len != want || !svc_sock_final_rec(svsk)) {
1104		svc_tcp_save_pages(svsk, rqstp);
1105		if (len < 0 && len != -EAGAIN)
1106			goto err_delete;
1107		if (len == want)
1108			svc_tcp_fragment_received(svsk);
1109		else
1110			dprintk("svc: incomplete TCP record (%d of %d)\n",
1111				(int)(svsk->sk_tcplen - sizeof(rpc_fraghdr)),
1112				svc_sock_reclen(svsk));
1113		goto err_noclose;
1114	}
1115
1116	if (svsk->sk_datalen < 8) {
1117		svsk->sk_datalen = 0;
1118		goto err_delete; /* client is nuts. */
1119	}
1120
1121	rqstp->rq_arg.len = svsk->sk_datalen;
1122	rqstp->rq_arg.page_base = 0;
1123	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1124		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1125		rqstp->rq_arg.page_len = 0;
1126	} else
1127		rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1128
1129	rqstp->rq_xprt_ctxt   = NULL;
1130	rqstp->rq_prot	      = IPPROTO_TCP;
1131	if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
1132		set_bit(RQ_LOCAL, &rqstp->rq_flags);
1133	else
1134		clear_bit(RQ_LOCAL, &rqstp->rq_flags);
1135
1136	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1137	calldir = p[1];
1138	if (calldir)
1139		len = receive_cb_reply(svsk, rqstp);
1140
1141	/* Reset TCP read info */
1142	svsk->sk_datalen = 0;
1143	svc_tcp_fragment_received(svsk);
1144
1145	if (len < 0)
1146		goto error;
1147
1148	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
1149	if (serv->sv_stats)
1150		serv->sv_stats->nettcpcnt++;
1151
1152	return rqstp->rq_arg.len;
1153
1154error:
1155	if (len != -EAGAIN)
1156		goto err_delete;
1157	dprintk("RPC: TCP recvfrom got EAGAIN\n");
1158	return 0;
1159err_delete:
1160	printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
1161	       svsk->sk_xprt.xpt_server->sv_name, -len);
1162	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1163err_noclose:
1164	return 0;	/* record not complete */
1165}
1166
1167/*
1168 * Send out data on TCP socket.
1169 */
1170static int svc_tcp_sendto(struct svc_rqst *rqstp)
1171{
1172	struct xdr_buf	*xbufp = &rqstp->rq_res;
1173	int sent;
1174	__be32 reclen;
1175
1176	/* Set up the first element of the reply kvec.
1177	 * Any other kvecs that may be in use have been taken
1178	 * care of by the server implementation itself.
1179	 */
1180	reclen = htonl(0x80000000|((xbufp->len ) - 4));
1181	memcpy(xbufp->head[0].iov_base, &reclen, 4);
1182
1183	sent = svc_sendto(rqstp, &rqstp->rq_res);
1184	if (sent != xbufp->len) {
1185		printk(KERN_NOTICE
1186		       "rpc-srv/tcp: %s: %s %d when sending %d bytes "
1187		       "- shutting down socket\n",
1188		       rqstp->rq_xprt->xpt_server->sv_name,
1189		       (sent<0)?"got error":"sent only",
1190		       sent, xbufp->len);
1191		set_bit(XPT_CLOSE, &rqstp->rq_xprt->xpt_flags);
1192		svc_xprt_enqueue(rqstp->rq_xprt);
1193		sent = -EAGAIN;
1194	}
1195	return sent;
1196}
1197
1198/*
1199 * Setup response header. TCP has a 4B record length field.
1200 */
1201static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
1202{
1203	struct kvec *resv = &rqstp->rq_res.head[0];
1204
1205	/* tcp needs a space for the record length... */
1206	svc_putnl(resv, 0);
1207}
1208
1209static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1210				       struct net *net,
1211				       struct sockaddr *sa, int salen,
1212				       int flags)
1213{
1214	return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1215}
1216
1217#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1218static struct svc_xprt *svc_bc_create_socket(struct svc_serv *, int,
1219					     struct net *, struct sockaddr *,
1220					     int, int);
1221static void svc_bc_sock_free(struct svc_xprt *xprt);
1222
1223static struct svc_xprt *svc_bc_tcp_create(struct svc_serv *serv,
1224				       struct net *net,
1225				       struct sockaddr *sa, int salen,
1226				       int flags)
1227{
1228	return svc_bc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1229}
1230
1231static void svc_bc_tcp_sock_detach(struct svc_xprt *xprt)
1232{
1233}
1234
1235static const struct svc_xprt_ops svc_tcp_bc_ops = {
1236	.xpo_create = svc_bc_tcp_create,
1237	.xpo_detach = svc_bc_tcp_sock_detach,
1238	.xpo_free = svc_bc_sock_free,
1239	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
1240	.xpo_secure_port = svc_sock_secure_port,
1241};
1242
1243static struct svc_xprt_class svc_tcp_bc_class = {
1244	.xcl_name = "tcp-bc",
1245	.xcl_owner = THIS_MODULE,
1246	.xcl_ops = &svc_tcp_bc_ops,
1247	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1248};
1249
1250static void svc_init_bc_xprt_sock(void)
1251{
1252	svc_reg_xprt_class(&svc_tcp_bc_class);
1253}
1254
1255static void svc_cleanup_bc_xprt_sock(void)
1256{
1257	svc_unreg_xprt_class(&svc_tcp_bc_class);
1258}
1259#else /* CONFIG_SUNRPC_BACKCHANNEL */
1260static void svc_init_bc_xprt_sock(void)
1261{
1262}
1263
1264static void svc_cleanup_bc_xprt_sock(void)
1265{
1266}
1267#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1268
1269static const struct svc_xprt_ops svc_tcp_ops = {
1270	.xpo_create = svc_tcp_create,
1271	.xpo_recvfrom = svc_tcp_recvfrom,
1272	.xpo_sendto = svc_tcp_sendto,
1273	.xpo_release_rqst = svc_release_skb,
1274	.xpo_detach = svc_tcp_sock_detach,
1275	.xpo_free = svc_sock_free,
1276	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
1277	.xpo_has_wspace = svc_tcp_has_wspace,
1278	.xpo_accept = svc_tcp_accept,
1279	.xpo_secure_port = svc_sock_secure_port,
1280	.xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt,
1281};
1282
1283static struct svc_xprt_class svc_tcp_class = {
1284	.xcl_name = "tcp",
1285	.xcl_owner = THIS_MODULE,
1286	.xcl_ops = &svc_tcp_ops,
1287	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1288	.xcl_ident = XPRT_TRANSPORT_TCP,
1289};
1290
1291void svc_init_xprt_sock(void)
1292{
1293	svc_reg_xprt_class(&svc_tcp_class);
1294	svc_reg_xprt_class(&svc_udp_class);
1295	svc_init_bc_xprt_sock();
1296}
1297
1298void svc_cleanup_xprt_sock(void)
1299{
1300	svc_unreg_xprt_class(&svc_tcp_class);
1301	svc_unreg_xprt_class(&svc_udp_class);
1302	svc_cleanup_bc_xprt_sock();
1303}
1304
1305static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1306{
1307	struct sock	*sk = svsk->sk_sk;
1308
1309	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
1310		      &svsk->sk_xprt, serv);
1311	set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
1312	set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
1313	if (sk->sk_state == TCP_LISTEN) {
1314		dprintk("setting up TCP socket for listening\n");
1315		strcpy(svsk->sk_xprt.xpt_remotebuf, "listener");
1316		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
1317		sk->sk_data_ready = svc_tcp_listen_data_ready;
1318		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
1319	} else {
1320		dprintk("setting up TCP socket for reading\n");
1321		sk->sk_state_change = svc_tcp_state_change;
1322		sk->sk_data_ready = svc_data_ready;
1323		sk->sk_write_space = svc_write_space;
1324
1325		svsk->sk_reclen = 0;
1326		svsk->sk_tcplen = 0;
1327		svsk->sk_datalen = 0;
1328		memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
1329
1330		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1331
1332		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
1333		switch (sk->sk_state) {
1334		case TCP_SYN_RECV:
1335		case TCP_ESTABLISHED:
1336			break;
1337		default:
1338			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1339		}
1340	}
1341}
1342
1343void svc_sock_update_bufs(struct svc_serv *serv)
1344{
1345	/*
1346	 * The number of server threads has changed. Update
1347	 * rcvbuf and sndbuf accordingly on all sockets
1348	 */
1349	struct svc_sock *svsk;
1350
1351	spin_lock_bh(&serv->sv_lock);
1352	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1353		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1354	spin_unlock_bh(&serv->sv_lock);
1355}
1356EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
1357
1358/*
1359 * Initialize socket for RPC use and create svc_sock struct
1360 */
1361static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1362						struct socket *sock,
1363						int flags)
1364{
1365	struct svc_sock	*svsk;
1366	struct sock	*inet;
1367	int		pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1368	int		err = 0;
1369
1370	dprintk("svc: svc_setup_socket %p\n", sock);
1371	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1372	if (!svsk)
1373		return ERR_PTR(-ENOMEM);
1374
1375	inet = sock->sk;
1376
1377	/* Register socket with portmapper */
1378	if (pmap_register)
1379		err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
1380				     inet->sk_protocol,
1381				     ntohs(inet_sk(inet)->inet_sport));
1382
1383	if (err < 0) {
1384		kfree(svsk);
1385		return ERR_PTR(err);
1386	}
1387
1388	svsk->sk_sock = sock;
1389	svsk->sk_sk = inet;
1390	svsk->sk_ostate = inet->sk_state_change;
1391	svsk->sk_odata = inet->sk_data_ready;
1392	svsk->sk_owspace = inet->sk_write_space;
1393	/*
1394	 * This barrier is necessary in order to prevent race condition
1395	 * with svc_data_ready(), svc_listen_data_ready() and others
1396	 * when calling callbacks above.
1397	 */
1398	wmb();
1399	inet->sk_user_data = svsk;
1400
1401	/* Initialize the socket */
1402	if (sock->type == SOCK_DGRAM)
1403		svc_udp_init(svsk, serv);
1404	else
1405		svc_tcp_init(svsk, serv);
1406
1407	dprintk("svc: svc_setup_socket created %p (inet %p), "
1408			"listen %d close %d\n",
1409			svsk, svsk->sk_sk,
1410			test_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags),
1411			test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
1412
1413	return svsk;
1414}
1415
1416bool svc_alien_sock(struct net *net, int fd)
1417{
1418	int err;
1419	struct socket *sock = sockfd_lookup(fd, &err);
1420	bool ret = false;
1421
1422	if (!sock)
1423		goto out;
1424	if (sock_net(sock->sk) != net)
1425		ret = true;
1426	sockfd_put(sock);
1427out:
1428	return ret;
1429}
1430EXPORT_SYMBOL_GPL(svc_alien_sock);
1431
1432/**
1433 * svc_addsock - add a listener socket to an RPC service
1434 * @serv: pointer to RPC service to which to add a new listener
1435 * @fd: file descriptor of the new listener
1436 * @name_return: pointer to buffer to fill in with name of listener
1437 * @len: size of the buffer
 
1438 *
1439 * Fills in socket name and returns positive length of name if successful.
1440 * Name is terminated with '\n'.  On error, returns a negative errno
1441 * value.
1442 */
1443int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
1444		const size_t len)
1445{
1446	int err = 0;
1447	struct socket *so = sockfd_lookup(fd, &err);
1448	struct svc_sock *svsk = NULL;
1449	struct sockaddr_storage addr;
1450	struct sockaddr *sin = (struct sockaddr *)&addr;
1451	int salen;
1452
1453	if (!so)
1454		return err;
1455	err = -EAFNOSUPPORT;
1456	if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1457		goto out;
1458	err =  -EPROTONOSUPPORT;
1459	if (so->sk->sk_protocol != IPPROTO_TCP &&
1460	    so->sk->sk_protocol != IPPROTO_UDP)
1461		goto out;
1462	err = -EISCONN;
1463	if (so->state > SS_UNCONNECTED)
1464		goto out;
1465	err = -ENOENT;
1466	if (!try_module_get(THIS_MODULE))
1467		goto out;
1468	svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
1469	if (IS_ERR(svsk)) {
1470		module_put(THIS_MODULE);
1471		err = PTR_ERR(svsk);
1472		goto out;
1473	}
1474	salen = kernel_getsockname(svsk->sk_sock, sin);
1475	if (salen >= 0)
1476		svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
 
1477	svc_add_new_perm_xprt(serv, &svsk->sk_xprt);
1478	return svc_one_sock_name(svsk, name_return, len);
1479out:
1480	sockfd_put(so);
1481	return err;
1482}
1483EXPORT_SYMBOL_GPL(svc_addsock);
1484
1485/*
1486 * Create socket for RPC service.
1487 */
1488static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1489					  int protocol,
1490					  struct net *net,
1491					  struct sockaddr *sin, int len,
1492					  int flags)
1493{
1494	struct svc_sock	*svsk;
1495	struct socket	*sock;
1496	int		error;
1497	int		type;
1498	struct sockaddr_storage addr;
1499	struct sockaddr *newsin = (struct sockaddr *)&addr;
1500	int		newlen;
1501	int		family;
1502	int		val;
1503	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1504
1505	dprintk("svc: svc_create_socket(%s, %d, %s)\n",
1506			serv->sv_program->pg_name, protocol,
1507			__svc_print_addr(sin, buf, sizeof(buf)));
1508
1509	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1510		printk(KERN_WARNING "svc: only UDP and TCP "
1511				"sockets supported\n");
1512		return ERR_PTR(-EINVAL);
1513	}
1514
1515	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1516	switch (sin->sa_family) {
1517	case AF_INET6:
1518		family = PF_INET6;
1519		break;
1520	case AF_INET:
1521		family = PF_INET;
1522		break;
1523	default:
1524		return ERR_PTR(-EINVAL);
1525	}
1526
1527	error = __sock_create(net, family, type, protocol, &sock, 1);
1528	if (error < 0)
1529		return ERR_PTR(error);
1530
1531	svc_reclassify_socket(sock);
1532
1533	/*
1534	 * If this is an PF_INET6 listener, we want to avoid
1535	 * getting requests from IPv4 remotes.  Those should
1536	 * be shunted to a PF_INET listener via rpcbind.
1537	 */
1538	val = 1;
1539	if (family == PF_INET6)
1540		kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
1541					(char *)&val, sizeof(val));
1542
1543	if (type == SOCK_STREAM)
1544		sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
1545	error = kernel_bind(sock, sin, len);
1546	if (error < 0)
1547		goto bummer;
1548
1549	error = kernel_getsockname(sock, newsin);
1550	if (error < 0)
1551		goto bummer;
1552	newlen = error;
1553
1554	if (protocol == IPPROTO_TCP) {
1555		if ((error = kernel_listen(sock, 64)) < 0)
1556			goto bummer;
1557	}
1558
1559	svsk = svc_setup_socket(serv, sock, flags);
1560	if (IS_ERR(svsk)) {
1561		error = PTR_ERR(svsk);
1562		goto bummer;
1563	}
1564	svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
1565	return (struct svc_xprt *)svsk;
1566bummer:
1567	dprintk("svc: svc_create_socket error = %d\n", -error);
1568	sock_release(sock);
1569	return ERR_PTR(error);
1570}
1571
1572/*
1573 * Detach the svc_sock from the socket so that no
1574 * more callbacks occur.
1575 */
1576static void svc_sock_detach(struct svc_xprt *xprt)
1577{
1578	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1579	struct sock *sk = svsk->sk_sk;
1580
1581	dprintk("svc: svc_sock_detach(%p)\n", svsk);
1582
1583	/* put back the old socket callbacks */
1584	lock_sock(sk);
1585	sk->sk_state_change = svsk->sk_ostate;
1586	sk->sk_data_ready = svsk->sk_odata;
1587	sk->sk_write_space = svsk->sk_owspace;
1588	sk->sk_user_data = NULL;
1589	release_sock(sk);
1590}
1591
1592/*
1593 * Disconnect the socket, and reset the callbacks
1594 */
1595static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1596{
1597	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1598
1599	dprintk("svc: svc_tcp_sock_detach(%p)\n", svsk);
1600
1601	svc_sock_detach(xprt);
1602
1603	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
1604		svc_tcp_clear_pages(svsk);
1605		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
1606	}
1607}
1608
1609/*
1610 * Free the svc_sock's socket resources and the svc_sock itself.
1611 */
1612static void svc_sock_free(struct svc_xprt *xprt)
1613{
1614	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1615	dprintk("svc: svc_sock_free(%p)\n", svsk);
1616
1617	if (svsk->sk_sock->file)
1618		sockfd_put(svsk->sk_sock);
1619	else
1620		sock_release(svsk->sk_sock);
1621	kfree(svsk);
1622}
1623
1624#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1625/*
1626 * Create a back channel svc_xprt which shares the fore channel socket.
1627 */
1628static struct svc_xprt *svc_bc_create_socket(struct svc_serv *serv,
1629					     int protocol,
1630					     struct net *net,
1631					     struct sockaddr *sin, int len,
1632					     int flags)
1633{
1634	struct svc_sock *svsk;
1635	struct svc_xprt *xprt;
1636
1637	if (protocol != IPPROTO_TCP) {
1638		printk(KERN_WARNING "svc: only TCP sockets"
1639			" supported on shared back channel\n");
1640		return ERR_PTR(-EINVAL);
1641	}
1642
1643	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1644	if (!svsk)
1645		return ERR_PTR(-ENOMEM);
1646
1647	xprt = &svsk->sk_xprt;
1648	svc_xprt_init(net, &svc_tcp_bc_class, xprt, serv);
1649	set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
1650
1651	serv->sv_bc_xprt = xprt;
1652
1653	return xprt;
1654}
1655
1656/*
1657 * Free a back channel svc_sock.
1658 */
1659static void svc_bc_sock_free(struct svc_xprt *xprt)
1660{
1661	if (xprt)
1662		kfree(container_of(xprt, struct svc_sock, sk_xprt));
1663}
1664#endif /* CONFIG_SUNRPC_BACKCHANNEL */