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v4.6
 
   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/tcp.h>
  43#include <net/tcp_states.h>
  44#include <asm/uaccess.h>
 
  45#include <asm/ioctls.h>
  46#include <trace/events/skb.h>
  47
  48#include <linux/sunrpc/types.h>
  49#include <linux/sunrpc/clnt.h>
  50#include <linux/sunrpc/xdr.h>
  51#include <linux/sunrpc/msg_prot.h>
  52#include <linux/sunrpc/svcsock.h>
  53#include <linux/sunrpc/stats.h>
  54#include <linux/sunrpc/xprt.h>
  55
 
 
 
  56#include "sunrpc.h"
  57
  58#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
  59
  60
  61static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
  62					 int flags);
  63static void		svc_udp_data_ready(struct sock *);
  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	WARN_ON_ONCE(sock_owned_by_user(sk));
  89	if (sock_owned_by_user(sk))
  90		return;
  91
  92	switch (sk->sk_family) {
  93	case AF_INET:
  94		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
  95					      &svc_slock_key[0],
  96					      "sk_xprt.xpt_lock-AF_INET-NFSD",
  97					      &svc_key[0]);
  98		break;
  99
 100	case AF_INET6:
 101		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
 102					      &svc_slock_key[1],
 103					      "sk_xprt.xpt_lock-AF_INET6-NFSD",
 104					      &svc_key[1]);
 105		break;
 106
 107	default:
 108		BUG();
 109	}
 110}
 111#else
 112static void svc_reclassify_socket(struct socket *sock)
 113{
 114}
 115#endif
 116
 117/*
 118 * Release an skbuff after use
 
 
 
 
 
 
 
 
 
 
 
 119 */
 120static void svc_release_skb(struct svc_rqst *rqstp)
 121{
 122	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
 123
 124	if (skb) {
 125		struct svc_sock *svsk =
 126			container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 127		rqstp->rq_xprt_ctxt = NULL;
 128
 129		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
 130		skb_free_datagram_locked(svsk->sk_sk, skb);
 131	}
 132}
 133
 134union svc_pktinfo_u {
 135	struct in_pktinfo pkti;
 136	struct in6_pktinfo pkti6;
 137};
 138#define SVC_PKTINFO_SPACE \
 139	CMSG_SPACE(sizeof(union svc_pktinfo_u))
 140
 141static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
 142{
 143	struct svc_sock *svsk =
 144		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 145	switch (svsk->sk_sk->sk_family) {
 146	case AF_INET: {
 147			struct in_pktinfo *pki = CMSG_DATA(cmh);
 148
 149			cmh->cmsg_level = SOL_IP;
 150			cmh->cmsg_type = IP_PKTINFO;
 151			pki->ipi_ifindex = 0;
 152			pki->ipi_spec_dst.s_addr =
 153				 svc_daddr_in(rqstp)->sin_addr.s_addr;
 154			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 155		}
 156		break;
 157
 158	case AF_INET6: {
 159			struct in6_pktinfo *pki = CMSG_DATA(cmh);
 160			struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 161
 162			cmh->cmsg_level = SOL_IPV6;
 163			cmh->cmsg_type = IPV6_PKTINFO;
 164			pki->ipi6_ifindex = daddr->sin6_scope_id;
 165			pki->ipi6_addr = daddr->sin6_addr;
 166			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 167		}
 168		break;
 169	}
 170}
 171
 172/*
 173 * send routine intended to be shared by the fore- and back-channel
 174 */
 175int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
 176		    struct page *headpage, unsigned long headoffset,
 177		    struct page *tailpage, unsigned long tailoffset)
 178{
 179	int		result;
 180	int		size;
 181	struct page	**ppage = xdr->pages;
 182	size_t		base = xdr->page_base;
 183	unsigned int	pglen = xdr->page_len;
 184	unsigned int	flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
 185	int		slen;
 186	int		len = 0;
 187
 188	slen = xdr->len;
 189
 190	/* send head */
 191	if (slen == xdr->head[0].iov_len)
 192		flags = 0;
 193	len = kernel_sendpage(sock, headpage, headoffset,
 194				  xdr->head[0].iov_len, flags);
 195	if (len != xdr->head[0].iov_len)
 196		goto out;
 197	slen -= xdr->head[0].iov_len;
 198	if (slen == 0)
 199		goto out;
 200
 201	/* send page data */
 202	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
 203	while (pglen > 0) {
 204		if (slen == size)
 205			flags = 0;
 206		result = kernel_sendpage(sock, *ppage, base, size, flags);
 207		if (result > 0)
 208			len += result;
 209		if (result != size)
 210			goto out;
 211		slen -= size;
 212		pglen -= size;
 213		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
 214		base = 0;
 215		ppage++;
 216	}
 217
 218	/* send tail */
 219	if (xdr->tail[0].iov_len) {
 220		result = kernel_sendpage(sock, tailpage, tailoffset,
 221				   xdr->tail[0].iov_len, 0);
 222		if (result > 0)
 223			len += result;
 224	}
 225
 226out:
 227	return len;
 228}
 229
 230
 231/*
 232 * Generic sendto routine
 233 */
 234static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
 235{
 236	struct svc_sock	*svsk =
 237		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 238	struct socket	*sock = svsk->sk_sock;
 239	union {
 240		struct cmsghdr	hdr;
 241		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 242	} buffer;
 243	struct cmsghdr *cmh = &buffer.hdr;
 244	int		len = 0;
 245	unsigned long tailoff;
 246	unsigned long headoff;
 247	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 248
 249	if (rqstp->rq_prot == IPPROTO_UDP) {
 250		struct msghdr msg = {
 251			.msg_name	= &rqstp->rq_addr,
 252			.msg_namelen	= rqstp->rq_addrlen,
 253			.msg_control	= cmh,
 254			.msg_controllen	= sizeof(buffer),
 255			.msg_flags	= MSG_MORE,
 256		};
 257
 258		svc_set_cmsg_data(rqstp, cmh);
 259
 260		if (sock_sendmsg(sock, &msg) < 0)
 261			goto out;
 262	}
 263
 264	tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
 265	headoff = 0;
 266	len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
 267			       rqstp->rq_respages[0], tailoff);
 268
 269out:
 270	dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
 271		svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
 272		xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
 273
 274	return len;
 275}
 276
 277/*
 278 * Report socket names for nfsdfs
 279 */
 280static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
 281{
 282	const struct sock *sk = svsk->sk_sk;
 283	const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
 284							"udp" : "tcp";
 285	int len;
 286
 287	switch (sk->sk_family) {
 288	case PF_INET:
 289		len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
 290				proto_name,
 291				&inet_sk(sk)->inet_rcv_saddr,
 292				inet_sk(sk)->inet_num);
 293		break;
 294#if IS_ENABLED(CONFIG_IPV6)
 295	case PF_INET6:
 296		len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
 297				proto_name,
 298				&sk->sk_v6_rcv_saddr,
 299				inet_sk(sk)->inet_num);
 300		break;
 301#endif
 302	default:
 303		len = snprintf(buf, remaining, "*unknown-%d*\n",
 304				sk->sk_family);
 305	}
 306
 307	if (len >= remaining) {
 308		*buf = '\0';
 309		return -ENAMETOOLONG;
 310	}
 311	return len;
 312}
 313
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 314/*
 315 * Generic recvfrom routine.
 
 
 316 */
 317static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
 318			int buflen)
 319{
 320	struct svc_sock *svsk =
 321		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 322	struct msghdr msg = {
 323		.msg_flags	= MSG_DONTWAIT,
 324	};
 325	int len;
 326
 327	rqstp->rq_xprt_hlen = 0;
 328
 329	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 330	len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
 331				msg.msg_flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 332	/* If we read a full record, then assume there may be more
 333	 * data to read (stream based sockets only!)
 334	 */
 335	if (len == buflen)
 336		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 337
 338	dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
 339		svsk, iov[0].iov_base, iov[0].iov_len, len);
 340	return len;
 341}
 342
 343static int svc_partial_recvfrom(struct svc_rqst *rqstp,
 344				struct kvec *iov, int nr,
 345				int buflen, unsigned int base)
 346{
 347	size_t save_iovlen;
 348	void *save_iovbase;
 349	unsigned int i;
 350	int ret;
 351
 352	if (base == 0)
 353		return svc_recvfrom(rqstp, iov, nr, buflen);
 354
 355	for (i = 0; i < nr; i++) {
 356		if (iov[i].iov_len > base)
 357			break;
 358		base -= iov[i].iov_len;
 359	}
 360	save_iovlen = iov[i].iov_len;
 361	save_iovbase = iov[i].iov_base;
 362	iov[i].iov_len -= base;
 363	iov[i].iov_base += base;
 364	ret = svc_recvfrom(rqstp, &iov[i], nr - i, buflen);
 365	iov[i].iov_len = save_iovlen;
 366	iov[i].iov_base = save_iovbase;
 367	return ret;
 368}
 369
 370/*
 371 * Set socket snd and rcv buffer lengths
 372 */
 373static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
 374				unsigned int rcv)
 375{
 376#if 0
 377	mm_segment_t	oldfs;
 378	oldfs = get_fs(); set_fs(KERNEL_DS);
 379	sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
 380			(char*)&snd, sizeof(snd));
 381	sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
 382			(char*)&rcv, sizeof(rcv));
 383#else
 384	/* sock_setsockopt limits use to sysctl_?mem_max,
 385	 * which isn't acceptable.  Until that is made conditional
 386	 * on not having CAP_SYS_RESOURCE or similar, we go direct...
 387	 * DaveM said I could!
 388	 */
 389	lock_sock(sock->sk);
 390	sock->sk->sk_sndbuf = snd * 2;
 391	sock->sk->sk_rcvbuf = rcv * 2;
 392	sock->sk->sk_write_space(sock->sk);
 393	release_sock(sock->sk);
 394#endif
 395}
 396
 397static int svc_sock_secure_port(struct svc_rqst *rqstp)
 398{
 399	return svc_port_is_privileged(svc_addr(rqstp));
 400}
 401
 402static bool sunrpc_waitqueue_active(wait_queue_head_t *wq)
 403{
 404	if (!wq)
 405		return false;
 406	/*
 407	 * There should normally be a memory * barrier here--see
 408	 * wq_has_sleeper().
 409	 *
 410	 * It appears that isn't currently necessary, though, basically
 411	 * because callers all appear to have sufficient memory barriers
 412	 * between the time the relevant change is made and the
 413	 * time they call these callbacks.
 414	 *
 415	 * The nfsd code itself doesn't actually explicitly wait on
 416	 * these waitqueues, but it may wait on them for example in
 417	 * sendpage() or sendmsg() calls.  (And those may be the only
 418	 * places, since it it uses nonblocking reads.)
 419	 *
 420	 * Maybe we should add the memory barriers anyway, but these are
 421	 * hot paths so we'd need to be convinced there's no sigificant
 422	 * penalty.
 423	 */
 424	return waitqueue_active(wq);
 425}
 426
 427/*
 428 * INET callback when data has been received on the socket.
 429 */
 430static void svc_udp_data_ready(struct sock *sk)
 431{
 432	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 433	wait_queue_head_t *wq = sk_sleep(sk);
 434
 435	if (svsk) {
 436		dprintk("svc: socket %p(inet %p), busy=%d\n",
 437			svsk, sk,
 438			test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
 439		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 440		svc_xprt_enqueue(&svsk->sk_xprt);
 
 441	}
 442	if (sunrpc_waitqueue_active(wq))
 443		wake_up_interruptible(wq);
 444}
 445
 446/*
 447 * INET callback when space is newly available on the socket.
 448 */
 449static void svc_write_space(struct sock *sk)
 450{
 451	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
 452	wait_queue_head_t *wq = sk_sleep(sk);
 453
 454	if (svsk) {
 455		dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
 456			svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
 
 
 457		svc_xprt_enqueue(&svsk->sk_xprt);
 458	}
 459
 460	if (sunrpc_waitqueue_active(wq)) {
 461		dprintk("RPC svc_write_space: someone sleeping on %p\n",
 462		       svsk);
 463		wake_up_interruptible(wq);
 464	}
 465}
 466
 467static int svc_tcp_has_wspace(struct svc_xprt *xprt)
 468{
 469	struct svc_sock *svsk =	container_of(xprt, struct svc_sock, sk_xprt);
 470	struct svc_serv *serv = svsk->sk_xprt.xpt_server;
 471	int required;
 472
 473	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
 474		return 1;
 475	required = atomic_read(&xprt->xpt_reserved) + serv->sv_max_mesg;
 476	if (sk_stream_wspace(svsk->sk_sk) >= required ||
 477	    (sk_stream_min_wspace(svsk->sk_sk) == 0 &&
 478	     atomic_read(&xprt->xpt_reserved) == 0))
 479		return 1;
 480	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 481	return 0;
 482}
 483
 484static void svc_tcp_write_space(struct sock *sk)
 485{
 486	struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data);
 487	struct socket *sock = sk->sk_socket;
 488
 489	if (!sk_stream_is_writeable(sk) || !sock)
 490		return;
 491	if (!svsk || svc_tcp_has_wspace(&svsk->sk_xprt))
 492		clear_bit(SOCK_NOSPACE, &sock->flags);
 493	svc_write_space(sk);
 494}
 495
 496static void svc_tcp_adjust_wspace(struct svc_xprt *xprt)
 497{
 498	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 499
 500	if (svc_tcp_has_wspace(xprt))
 501		clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 502}
 503
 504/*
 505 * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
 506 */
 507static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
 508				     struct cmsghdr *cmh)
 509{
 510	struct in_pktinfo *pki = CMSG_DATA(cmh);
 511	struct sockaddr_in *daddr = svc_daddr_in(rqstp);
 512
 513	if (cmh->cmsg_type != IP_PKTINFO)
 514		return 0;
 515
 516	daddr->sin_family = AF_INET;
 517	daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
 518	return 1;
 519}
 520
 521/*
 522 * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
 523 */
 524static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
 525				     struct cmsghdr *cmh)
 526{
 527	struct in6_pktinfo *pki = CMSG_DATA(cmh);
 528	struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 529
 530	if (cmh->cmsg_type != IPV6_PKTINFO)
 531		return 0;
 532
 533	daddr->sin6_family = AF_INET6;
 534	daddr->sin6_addr = pki->ipi6_addr;
 535	daddr->sin6_scope_id = pki->ipi6_ifindex;
 536	return 1;
 537}
 538
 539/*
 540 * Copy the UDP datagram's destination address to the rqstp structure.
 541 * The 'destination' address in this case is the address to which the
 542 * peer sent the datagram, i.e. our local address. For multihomed
 543 * hosts, this can change from msg to msg. Note that only the IP
 544 * address changes, the port number should remain the same.
 545 */
 546static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
 547				    struct cmsghdr *cmh)
 548{
 549	switch (cmh->cmsg_level) {
 550	case SOL_IP:
 551		return svc_udp_get_dest_address4(rqstp, cmh);
 552	case SOL_IPV6:
 553		return svc_udp_get_dest_address6(rqstp, cmh);
 554	}
 555
 556	return 0;
 557}
 558
 559/*
 560 * Receive a datagram from a UDP socket.
 
 
 
 
 
 
 
 561 */
 562static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 563{
 564	struct svc_sock	*svsk =
 565		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 566	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 567	struct sk_buff	*skb;
 568	union {
 569		struct cmsghdr	hdr;
 570		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 571	} buffer;
 572	struct cmsghdr *cmh = &buffer.hdr;
 573	struct msghdr msg = {
 574		.msg_name = svc_addr(rqstp),
 575		.msg_control = cmh,
 576		.msg_controllen = sizeof(buffer),
 577		.msg_flags = MSG_DONTWAIT,
 578	};
 579	size_t len;
 580	int err;
 581
 582	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
 583	    /* udp sockets need large rcvbuf as all pending
 584	     * requests are still in that buffer.  sndbuf must
 585	     * also be large enough that there is enough space
 586	     * for one reply per thread.  We count all threads
 587	     * rather than threads in a particular pool, which
 588	     * provides an upper bound on the number of threads
 589	     * which will access the socket.
 590	     */
 591	    svc_sock_setbufsize(svsk->sk_sock,
 592				(serv->sv_nrthreads+3) * serv->sv_max_mesg,
 593				(serv->sv_nrthreads+3) * serv->sv_max_mesg);
 594
 595	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 596	skb = NULL;
 597	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
 598			     0, 0, MSG_PEEK | MSG_DONTWAIT);
 599	if (err >= 0)
 600		skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err);
 
 
 
 601
 602	if (skb == NULL) {
 603		if (err != -EAGAIN) {
 604			/* possibly an icmp error */
 605			dprintk("svc: recvfrom returned error %d\n", -err);
 606			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 607		}
 608		return 0;
 609	}
 610	len = svc_addr_len(svc_addr(rqstp));
 611	rqstp->rq_addrlen = len;
 612	if (skb->tstamp.tv64 == 0) {
 613		skb->tstamp = ktime_get_real();
 614		/* Don't enable netstamp, sunrpc doesn't
 615		   need that much accuracy */
 616	}
 617	svsk->sk_sk->sk_stamp = skb->tstamp;
 618	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
 619
 620	len  = skb->len - sizeof(struct udphdr);
 621	rqstp->rq_arg.len = len;
 
 622
 623	rqstp->rq_prot = IPPROTO_UDP;
 624
 625	if (!svc_udp_get_dest_address(rqstp, cmh)) {
 626		net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
 627				     cmh->cmsg_level, cmh->cmsg_type);
 628		goto out_free;
 629	}
 630	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
 631
 632	if (skb_is_nonlinear(skb)) {
 633		/* we have to copy */
 634		local_bh_disable();
 635		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
 636			local_bh_enable();
 637			/* checksum error */
 638			goto out_free;
 639		}
 640		local_bh_enable();
 641		skb_free_datagram_locked(svsk->sk_sk, skb);
 642	} else {
 643		/* we can use it in-place */
 644		rqstp->rq_arg.head[0].iov_base = skb->data +
 645			sizeof(struct udphdr);
 646		rqstp->rq_arg.head[0].iov_len = len;
 647		if (skb_checksum_complete(skb))
 648			goto out_free;
 649		rqstp->rq_xprt_ctxt = skb;
 650	}
 651
 652	rqstp->rq_arg.page_base = 0;
 653	if (len <= rqstp->rq_arg.head[0].iov_len) {
 654		rqstp->rq_arg.head[0].iov_len = len;
 655		rqstp->rq_arg.page_len = 0;
 656		rqstp->rq_respages = rqstp->rq_pages+1;
 657	} else {
 658		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
 659		rqstp->rq_respages = rqstp->rq_pages + 1 +
 660			DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
 661	}
 662	rqstp->rq_next_page = rqstp->rq_respages+1;
 663
 664	if (serv->sv_stats)
 665		serv->sv_stats->netudpcnt++;
 666
 
 667	return len;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 668out_free:
 669	trace_kfree_skb(skb, svc_udp_recvfrom);
 670	skb_free_datagram_locked(svsk->sk_sk, skb);
 
 671	return 0;
 672}
 673
 674static int
 675svc_udp_sendto(struct svc_rqst *rqstp)
 
 
 
 
 
 
 
 
 676{
 677	int		error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 678
 679	error = svc_sendto(rqstp, &rqstp->rq_res);
 680	if (error == -ECONNREFUSED)
 681		/* ICMP error on earlier request. */
 682		error = svc_sendto(rqstp, &rqstp->rq_res);
 683
 684	return error;
 685}
 686
 687static void svc_udp_prep_reply_hdr(struct svc_rqst *rqstp)
 688{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 689}
 690
 691static int svc_udp_has_wspace(struct svc_xprt *xprt)
 692{
 693	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 694	struct svc_serv	*serv = xprt->xpt_server;
 695	unsigned long required;
 696
 697	/*
 698	 * Set the SOCK_NOSPACE flag before checking the available
 699	 * sock space.
 700	 */
 701	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 702	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
 703	if (required*2 > sock_wspace(svsk->sk_sk))
 704		return 0;
 705	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 706	return 1;
 707}
 708
 709static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
 710{
 711	BUG();
 712	return NULL;
 713}
 714
 
 
 
 
 715static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
 716				       struct net *net,
 717				       struct sockaddr *sa, int salen,
 718				       int flags)
 719{
 720	return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
 721}
 722
 723static struct svc_xprt_ops svc_udp_ops = {
 724	.xpo_create = svc_udp_create,
 725	.xpo_recvfrom = svc_udp_recvfrom,
 726	.xpo_sendto = svc_udp_sendto,
 727	.xpo_release_rqst = svc_release_skb,
 
 728	.xpo_detach = svc_sock_detach,
 729	.xpo_free = svc_sock_free,
 730	.xpo_prep_reply_hdr = svc_udp_prep_reply_hdr,
 731	.xpo_has_wspace = svc_udp_has_wspace,
 732	.xpo_accept = svc_udp_accept,
 733	.xpo_secure_port = svc_sock_secure_port,
 
 734};
 735
 736static struct svc_xprt_class svc_udp_class = {
 737	.xcl_name = "udp",
 738	.xcl_owner = THIS_MODULE,
 739	.xcl_ops = &svc_udp_ops,
 740	.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
 741	.xcl_ident = XPRT_TRANSPORT_UDP,
 742};
 743
 744static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
 745{
 746	int err, level, optname, one = 1;
 747
 748	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class,
 749		      &svsk->sk_xprt, serv);
 750	clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
 751	svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
 752	svsk->sk_sk->sk_write_space = svc_write_space;
 753
 754	/* initialise setting must have enough space to
 755	 * receive and respond to one request.
 756	 * svc_udp_recvfrom will re-adjust if necessary
 757	 */
 758	svc_sock_setbufsize(svsk->sk_sock,
 759			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
 760			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
 761
 762	/* data might have come in before data_ready set up */
 763	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 764	set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
 765
 766	/* make sure we get destination address info */
 767	switch (svsk->sk_sk->sk_family) {
 768	case AF_INET:
 769		level = SOL_IP;
 770		optname = IP_PKTINFO;
 771		break;
 772	case AF_INET6:
 773		level = SOL_IPV6;
 774		optname = IPV6_RECVPKTINFO;
 775		break;
 776	default:
 777		BUG();
 778	}
 779	err = kernel_setsockopt(svsk->sk_sock, level, optname,
 780					(char *)&one, sizeof(one));
 781	dprintk("svc: kernel_setsockopt returned %d\n", err);
 782}
 783
 784/*
 785 * A data_ready event on a listening socket means there's a connection
 786 * pending. Do not use state_change as a substitute for it.
 787 */
 788static void svc_tcp_listen_data_ready(struct sock *sk)
 789{
 790	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 791	wait_queue_head_t *wq;
 792
 793	dprintk("svc: socket %p TCP (listen) state change %d\n",
 794		sk, sk->sk_state);
 
 
 
 795
 796	/*
 797	 * This callback may called twice when a new connection
 798	 * is established as a child socket inherits everything
 799	 * from a parent LISTEN socket.
 800	 * 1) data_ready method of the parent socket will be called
 801	 *    when one of child sockets become ESTABLISHED.
 802	 * 2) data_ready method of the child socket may be called
 803	 *    when it receives data before the socket is accepted.
 804	 * In case of 2, we should ignore it silently.
 805	 */
 806	if (sk->sk_state == TCP_LISTEN) {
 807		if (svsk) {
 808			set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 809			svc_xprt_enqueue(&svsk->sk_xprt);
 810		} else
 811			printk("svc: socket %p: no user data\n", sk);
 812	}
 813
 814	wq = sk_sleep(sk);
 815	if (sunrpc_waitqueue_active(wq))
 816		wake_up_interruptible_all(wq);
 817}
 818
 819/*
 820 * A state change on a connected socket means it's dying or dead.
 821 */
 822static void svc_tcp_state_change(struct sock *sk)
 823{
 824	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 825	wait_queue_head_t *wq = sk_sleep(sk);
 826
 827	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
 828		sk, sk->sk_state, sk->sk_user_data);
 829
 830	if (!svsk)
 831		printk("svc: socket %p: no user data\n", sk);
 832	else {
 833		set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 834		svc_xprt_enqueue(&svsk->sk_xprt);
 835	}
 836	if (sunrpc_waitqueue_active(wq))
 837		wake_up_interruptible_all(wq);
 838}
 839
 840static void svc_tcp_data_ready(struct sock *sk)
 841{
 842	struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
 843	wait_queue_head_t *wq = sk_sleep(sk);
 844
 845	dprintk("svc: socket %p TCP data ready (svsk %p)\n",
 846		sk, sk->sk_user_data);
 847	if (svsk) {
 848		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 849		svc_xprt_enqueue(&svsk->sk_xprt);
 
 
 
 
 850	}
 851	if (sunrpc_waitqueue_active(wq))
 852		wake_up_interruptible(wq);
 853}
 854
 855/*
 856 * Accept a TCP connection
 857 */
 858static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
 859{
 860	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 861	struct sockaddr_storage addr;
 862	struct sockaddr	*sin = (struct sockaddr *) &addr;
 863	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 864	struct socket	*sock = svsk->sk_sock;
 865	struct socket	*newsock;
 866	struct svc_sock	*newsvsk;
 867	int		err, slen;
 868	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 869
 870	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
 871	if (!sock)
 872		return NULL;
 873
 874	clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 875	err = kernel_accept(sock, &newsock, O_NONBLOCK);
 876	if (err < 0) {
 877		if (err == -ENOMEM)
 878			printk(KERN_WARNING "%s: no more sockets!\n",
 879			       serv->sv_name);
 880		else if (err != -EAGAIN)
 881			net_warn_ratelimited("%s: accept failed (err %d)!\n",
 882					     serv->sv_name, -err);
 
 883		return NULL;
 884	}
 885	set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 886
 887	err = kernel_getpeername(newsock, sin, &slen);
 888	if (err < 0) {
 889		net_warn_ratelimited("%s: peername failed (err %d)!\n",
 890				     serv->sv_name, -err);
 891		goto failed;		/* aborted connection or whatever */
 892	}
 
 893
 894	/* Ideally, we would want to reject connections from unauthorized
 895	 * hosts here, but when we get encryption, the IP of the host won't
 896	 * tell us anything.  For now just warn about unpriv connections.
 897	 */
 898	if (!svc_port_is_privileged(sin)) {
 899		dprintk("%s: connect from unprivileged port: %s\n",
 900			serv->sv_name,
 901			__svc_print_addr(sin, buf, sizeof(buf)));
 902	}
 903	dprintk("%s: connect from %s\n", serv->sv_name,
 904		__svc_print_addr(sin, buf, sizeof(buf)));
 905
 906	/* make sure that a write doesn't block forever when
 907	 * low on memory
 908	 */
 909	newsock->sk->sk_sndtimeo = HZ*30;
 910
 911	newsvsk = svc_setup_socket(serv, newsock,
 912				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
 913	if (IS_ERR(newsvsk))
 914		goto failed;
 915	svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
 916	err = kernel_getsockname(newsock, sin, &slen);
 917	if (unlikely(err < 0)) {
 918		dprintk("svc_tcp_accept: kernel_getsockname error %d\n", -err);
 919		slen = offsetof(struct sockaddr, sa_data);
 920	}
 921	svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
 922
 923	if (sock_is_loopback(newsock->sk))
 924		set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 925	else
 926		clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 927	if (serv->sv_stats)
 928		serv->sv_stats->nettcpconn++;
 929
 930	return &newsvsk->sk_xprt;
 931
 932failed:
 933	sock_release(newsock);
 934	return NULL;
 935}
 936
 937static unsigned int svc_tcp_restore_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 
 938{
 939	unsigned int i, len, npages;
 
 940
 941	if (svsk->sk_datalen == 0)
 942		return 0;
 943	len = svsk->sk_datalen;
 944	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 945	for (i = 0; i < npages; i++) {
 946		if (rqstp->rq_pages[i] != NULL)
 947			put_page(rqstp->rq_pages[i]);
 948		BUG_ON(svsk->sk_pages[i] == NULL);
 949		rqstp->rq_pages[i] = svsk->sk_pages[i];
 950		svsk->sk_pages[i] = NULL;
 951	}
 952	rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
 953	return len;
 954}
 955
 956static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 957{
 958	unsigned int i, len, npages;
 959
 960	if (svsk->sk_datalen == 0)
 961		return;
 962	len = svsk->sk_datalen;
 963	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 964	for (i = 0; i < npages; i++) {
 965		svsk->sk_pages[i] = rqstp->rq_pages[i];
 966		rqstp->rq_pages[i] = NULL;
 967	}
 968}
 969
 970static void svc_tcp_clear_pages(struct svc_sock *svsk)
 971{
 972	unsigned int i, len, npages;
 973
 974	if (svsk->sk_datalen == 0)
 975		goto out;
 976	len = svsk->sk_datalen;
 977	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 978	for (i = 0; i < npages; i++) {
 979		if (svsk->sk_pages[i] == NULL) {
 980			WARN_ON_ONCE(1);
 981			continue;
 982		}
 983		put_page(svsk->sk_pages[i]);
 984		svsk->sk_pages[i] = NULL;
 985	}
 986out:
 987	svsk->sk_tcplen = 0;
 988	svsk->sk_datalen = 0;
 989}
 990
 991/*
 992 * Receive fragment record header.
 993 * If we haven't gotten the record length yet, get the next four bytes.
 994 */
 995static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
 
 996{
 997	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 998	unsigned int want;
 999	int len;
1000
 
 
 
1001	if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
 
1002		struct kvec	iov;
1003
1004		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
1005		iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
1006		iov.iov_len  = want;
1007		if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
1008			goto error;
 
 
1009		svsk->sk_tcplen += len;
1010
1011		if (len < want) {
1012			dprintk("svc: short recvfrom while reading record "
1013				"length (%d of %d)\n", len, want);
1014			return -EAGAIN;
1015		}
1016
1017		dprintk("svc: TCP record, %d bytes\n", svc_sock_reclen(svsk));
1018		if (svc_sock_reclen(svsk) + svsk->sk_datalen >
1019							serv->sv_max_mesg) {
1020			net_notice_ratelimited("RPC: fragment too large: %d\n",
1021					svc_sock_reclen(svsk));
1022			goto err_delete;
1023		}
1024	}
1025
1026	return svc_sock_reclen(svsk);
1027error:
1028	dprintk("RPC: TCP recv_record got %d\n", len);
1029	return len;
1030err_delete:
1031	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 
 
1032	return -EAGAIN;
1033}
1034
1035static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
1036{
1037	struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
1038	struct rpc_rqst *req = NULL;
1039	struct kvec *src, *dst;
1040	__be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1041	__be32 xid;
1042	__be32 calldir;
1043
1044	xid = *p++;
1045	calldir = *p;
1046
1047	if (!bc_xprt)
1048		return -EAGAIN;
1049	spin_lock_bh(&bc_xprt->transport_lock);
1050	req = xprt_lookup_rqst(bc_xprt, xid);
1051	if (!req)
1052		goto unlock_notfound;
1053
1054	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
1055	/*
1056	 * XXX!: cheating for now!  Only copying HEAD.
1057	 * But we know this is good enough for now (in fact, for any
1058	 * callback reply in the forseeable future).
1059	 */
1060	dst = &req->rq_private_buf.head[0];
1061	src = &rqstp->rq_arg.head[0];
1062	if (dst->iov_len < src->iov_len)
1063		goto unlock_eagain; /* whatever; just giving up. */
1064	memcpy(dst->iov_base, src->iov_base, src->iov_len);
1065	xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
1066	rqstp->rq_arg.len = 0;
1067	spin_unlock_bh(&bc_xprt->transport_lock);
1068	return 0;
1069unlock_notfound:
1070	printk(KERN_NOTICE
1071		"%s: Got unrecognized reply: "
1072		"calldir 0x%x xpt_bc_xprt %p xid %08x\n",
1073		__func__, ntohl(calldir),
1074		bc_xprt, ntohl(xid));
1075unlock_eagain:
1076	spin_unlock_bh(&bc_xprt->transport_lock);
1077	return -EAGAIN;
1078}
1079
1080static int copy_pages_to_kvecs(struct kvec *vec, struct page **pages, int len)
1081{
1082	int i = 0;
1083	int t = 0;
1084
1085	while (t < len) {
1086		vec[i].iov_base = page_address(pages[i]);
1087		vec[i].iov_len = PAGE_SIZE;
1088		i++;
1089		t += PAGE_SIZE;
1090	}
1091	return i;
1092}
1093
1094static void svc_tcp_fragment_received(struct svc_sock *svsk)
1095{
1096	/* If we have more data, signal svc_xprt_enqueue() to try again */
1097	dprintk("svc: TCP %s record (%d bytes)\n",
1098		svc_sock_final_rec(svsk) ? "final" : "nonfinal",
1099		svc_sock_reclen(svsk));
1100	svsk->sk_tcplen = 0;
1101	svsk->sk_reclen = 0;
1102}
1103
1104/*
1105 * Receive data from a TCP socket.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1106 */
1107static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
1108{
1109	struct svc_sock	*svsk =
1110		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
1111	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
1112	int		len;
1113	struct kvec *vec;
1114	unsigned int want, base;
1115	__be32 *p;
1116	__be32 calldir;
1117	int pnum;
1118
1119	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
1120		svsk, test_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags),
1121		test_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags),
1122		test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
1123
1124	len = svc_tcp_recv_record(svsk, rqstp);
1125	if (len < 0)
1126		goto error;
1127
1128	base = svc_tcp_restore_pages(svsk, rqstp);
1129	want = svc_sock_reclen(svsk) - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
1130
1131	vec = rqstp->rq_vec;
1132
1133	pnum = copy_pages_to_kvecs(&vec[0], &rqstp->rq_pages[0],
1134						svsk->sk_datalen + want);
1135
1136	rqstp->rq_respages = &rqstp->rq_pages[pnum];
1137	rqstp->rq_next_page = rqstp->rq_respages + 1;
1138
1139	/* Now receive data */
1140	len = svc_partial_recvfrom(rqstp, vec, pnum, want, base);
1141	if (len >= 0) {
 
1142		svsk->sk_tcplen += len;
1143		svsk->sk_datalen += len;
1144	}
1145	if (len != want || !svc_sock_final_rec(svsk)) {
1146		svc_tcp_save_pages(svsk, rqstp);
1147		if (len < 0 && len != -EAGAIN)
1148			goto err_delete;
1149		if (len == want)
1150			svc_tcp_fragment_received(svsk);
1151		else
1152			dprintk("svc: incomplete TCP record (%d of %d)\n",
1153				(int)(svsk->sk_tcplen - sizeof(rpc_fraghdr)),
1154				svc_sock_reclen(svsk));
1155		goto err_noclose;
1156	}
1157
1158	if (svsk->sk_datalen < 8) {
1159		svsk->sk_datalen = 0;
1160		goto err_delete; /* client is nuts. */
1161	}
1162
1163	rqstp->rq_arg.len = svsk->sk_datalen;
1164	rqstp->rq_arg.page_base = 0;
1165	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1166		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1167		rqstp->rq_arg.page_len = 0;
1168	} else
1169		rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1170
1171	rqstp->rq_xprt_ctxt   = NULL;
1172	rqstp->rq_prot	      = IPPROTO_TCP;
1173	if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
1174		set_bit(RQ_LOCAL, &rqstp->rq_flags);
1175	else
1176		clear_bit(RQ_LOCAL, &rqstp->rq_flags);
1177
1178	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1179	calldir = p[1];
1180	if (calldir)
1181		len = receive_cb_reply(svsk, rqstp);
1182
1183	/* Reset TCP read info */
1184	svsk->sk_datalen = 0;
1185	svc_tcp_fragment_received(svsk);
1186
1187	if (len < 0)
1188		goto error;
1189
1190	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
1191	if (serv->sv_stats)
1192		serv->sv_stats->nettcpcnt++;
1193
 
1194	return rqstp->rq_arg.len;
1195
 
 
 
 
 
 
 
 
 
 
 
1196error:
1197	if (len != -EAGAIN)
1198		goto err_delete;
1199	dprintk("RPC: TCP recvfrom got EAGAIN\n");
1200	return 0;
 
 
1201err_delete:
1202	printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
1203	       svsk->sk_xprt.xpt_server->sv_name, -len);
1204	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1205err_noclose:
 
1206	return 0;	/* record not complete */
1207}
1208
1209/*
1210 * Send out data on TCP socket.
1211 */
1212static int svc_tcp_sendto(struct svc_rqst *rqstp)
1213{
1214	struct xdr_buf	*xbufp = &rqstp->rq_res;
1215	int sent;
1216	__be32 reclen;
1217
1218	/* Set up the first element of the reply kvec.
1219	 * Any other kvecs that may be in use have been taken
1220	 * care of by the server implementation itself.
1221	 */
1222	reclen = htonl(0x80000000|((xbufp->len ) - 4));
1223	memcpy(xbufp->head[0].iov_base, &reclen, 4);
1224
1225	sent = svc_sendto(rqstp, &rqstp->rq_res);
1226	if (sent != xbufp->len) {
1227		printk(KERN_NOTICE
1228		       "rpc-srv/tcp: %s: %s %d when sending %d bytes "
1229		       "- shutting down socket\n",
1230		       rqstp->rq_xprt->xpt_server->sv_name,
1231		       (sent<0)?"got error":"sent only",
1232		       sent, xbufp->len);
1233		set_bit(XPT_CLOSE, &rqstp->rq_xprt->xpt_flags);
1234		svc_xprt_enqueue(rqstp->rq_xprt);
1235		sent = -EAGAIN;
1236	}
1237	return sent;
1238}
1239
1240/*
1241 * Setup response header. TCP has a 4B record length field.
 
 
 
 
 
1242 */
1243static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
 
1244{
1245	struct kvec *resv = &rqstp->rq_res.head[0];
 
 
 
 
 
 
 
 
 
1246
1247	/* tcp needs a space for the record length... */
1248	svc_putnl(resv, 0);
1249}
 
 
 
 
 
 
 
 
1250
1251static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1252				       struct net *net,
1253				       struct sockaddr *sa, int salen,
1254				       int flags)
1255{
1256	return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1257}
1258
1259#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1260static struct svc_xprt *svc_bc_create_socket(struct svc_serv *, int,
1261					     struct net *, struct sockaddr *,
1262					     int, int);
1263static void svc_bc_sock_free(struct svc_xprt *xprt);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1264
1265static struct svc_xprt *svc_bc_tcp_create(struct svc_serv *serv,
1266				       struct net *net,
1267				       struct sockaddr *sa, int salen,
1268				       int flags)
1269{
1270	return svc_bc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1271}
1272
1273static void svc_bc_tcp_sock_detach(struct svc_xprt *xprt)
1274{
1275}
1276
1277static struct svc_xprt_ops svc_tcp_bc_ops = {
1278	.xpo_create = svc_bc_tcp_create,
1279	.xpo_detach = svc_bc_tcp_sock_detach,
1280	.xpo_free = svc_bc_sock_free,
1281	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
1282	.xpo_secure_port = svc_sock_secure_port,
1283};
 
 
 
 
 
 
 
 
 
 
 
1284
1285static struct svc_xprt_class svc_tcp_bc_class = {
1286	.xcl_name = "tcp-bc",
1287	.xcl_owner = THIS_MODULE,
1288	.xcl_ops = &svc_tcp_bc_ops,
1289	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1290};
1291
1292static void svc_init_bc_xprt_sock(void)
1293{
1294	svc_reg_xprt_class(&svc_tcp_bc_class);
1295}
 
 
 
 
 
 
 
 
 
 
1296
1297static void svc_cleanup_bc_xprt_sock(void)
1298{
1299	svc_unreg_xprt_class(&svc_tcp_bc_class);
1300}
1301#else /* CONFIG_SUNRPC_BACKCHANNEL */
1302static void svc_init_bc_xprt_sock(void)
1303{
 
 
 
 
 
 
1304}
1305
1306static void svc_cleanup_bc_xprt_sock(void)
 
 
 
1307{
 
1308}
1309#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1310
1311static struct svc_xprt_ops svc_tcp_ops = {
1312	.xpo_create = svc_tcp_create,
1313	.xpo_recvfrom = svc_tcp_recvfrom,
1314	.xpo_sendto = svc_tcp_sendto,
1315	.xpo_release_rqst = svc_release_skb,
 
1316	.xpo_detach = svc_tcp_sock_detach,
1317	.xpo_free = svc_sock_free,
1318	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
1319	.xpo_has_wspace = svc_tcp_has_wspace,
1320	.xpo_accept = svc_tcp_accept,
1321	.xpo_secure_port = svc_sock_secure_port,
1322	.xpo_adjust_wspace = svc_tcp_adjust_wspace,
1323};
1324
1325static struct svc_xprt_class svc_tcp_class = {
1326	.xcl_name = "tcp",
1327	.xcl_owner = THIS_MODULE,
1328	.xcl_ops = &svc_tcp_ops,
1329	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1330	.xcl_ident = XPRT_TRANSPORT_TCP,
1331};
1332
1333void svc_init_xprt_sock(void)
1334{
1335	svc_reg_xprt_class(&svc_tcp_class);
1336	svc_reg_xprt_class(&svc_udp_class);
1337	svc_init_bc_xprt_sock();
1338}
1339
1340void svc_cleanup_xprt_sock(void)
1341{
1342	svc_unreg_xprt_class(&svc_tcp_class);
1343	svc_unreg_xprt_class(&svc_udp_class);
1344	svc_cleanup_bc_xprt_sock();
1345}
1346
1347static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1348{
1349	struct sock	*sk = svsk->sk_sk;
1350
1351	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
1352		      &svsk->sk_xprt, serv);
1353	set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
 
1354	if (sk->sk_state == TCP_LISTEN) {
1355		dprintk("setting up TCP socket for listening\n");
1356		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
1357		sk->sk_data_ready = svc_tcp_listen_data_ready;
1358		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
1359	} else {
1360		dprintk("setting up TCP socket for reading\n");
1361		sk->sk_state_change = svc_tcp_state_change;
1362		sk->sk_data_ready = svc_tcp_data_ready;
1363		sk->sk_write_space = svc_tcp_write_space;
1364
1365		svsk->sk_reclen = 0;
1366		svsk->sk_tcplen = 0;
1367		svsk->sk_datalen = 0;
1368		memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
1369
1370		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1371
1372		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
1373		if (sk->sk_state != TCP_ESTABLISHED)
1374			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
 
 
 
 
 
1375	}
1376}
1377
1378void svc_sock_update_bufs(struct svc_serv *serv)
1379{
1380	/*
1381	 * The number of server threads has changed. Update
1382	 * rcvbuf and sndbuf accordingly on all sockets
1383	 */
1384	struct svc_sock *svsk;
1385
1386	spin_lock_bh(&serv->sv_lock);
1387	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1388		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1389	spin_unlock_bh(&serv->sv_lock);
1390}
1391EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
1392
1393/*
1394 * Initialize socket for RPC use and create svc_sock struct
1395 */
1396static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1397						struct socket *sock,
1398						int flags)
1399{
1400	struct svc_sock	*svsk;
1401	struct sock	*inet;
1402	int		pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1403	int		err = 0;
1404
1405	dprintk("svc: svc_setup_socket %p\n", sock);
1406	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1407	if (!svsk)
1408		return ERR_PTR(-ENOMEM);
1409
1410	inet = sock->sk;
1411
1412	/* Register socket with portmapper */
1413	if (pmap_register)
1414		err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
1415				     inet->sk_protocol,
1416				     ntohs(inet_sk(inet)->inet_sport));
1417
1418	if (err < 0) {
1419		kfree(svsk);
1420		return ERR_PTR(err);
1421	}
1422
1423	inet->sk_user_data = svsk;
1424	svsk->sk_sock = sock;
1425	svsk->sk_sk = inet;
1426	svsk->sk_ostate = inet->sk_state_change;
1427	svsk->sk_odata = inet->sk_data_ready;
1428	svsk->sk_owspace = inet->sk_write_space;
 
 
 
 
 
 
 
1429
1430	/* Initialize the socket */
1431	if (sock->type == SOCK_DGRAM)
1432		svc_udp_init(svsk, serv);
1433	else {
1434		/* initialise setting must have enough space to
1435		 * receive and respond to one request.
1436		 */
1437		svc_sock_setbufsize(svsk->sk_sock, 4 * serv->sv_max_mesg,
1438					4 * serv->sv_max_mesg);
1439		svc_tcp_init(svsk, serv);
1440	}
1441
1442	dprintk("svc: svc_setup_socket created %p (inet %p)\n",
1443				svsk, svsk->sk_sk);
1444
 
1445	return svsk;
1446}
1447
1448bool svc_alien_sock(struct net *net, int fd)
1449{
1450	int err;
1451	struct socket *sock = sockfd_lookup(fd, &err);
1452	bool ret = false;
1453
1454	if (!sock)
1455		goto out;
1456	if (sock_net(sock->sk) != net)
1457		ret = true;
1458	sockfd_put(sock);
1459out:
1460	return ret;
1461}
1462EXPORT_SYMBOL_GPL(svc_alien_sock);
1463
1464/**
1465 * svc_addsock - add a listener socket to an RPC service
1466 * @serv: pointer to RPC service to which to add a new listener
1467 * @fd: file descriptor of the new listener
1468 * @name_return: pointer to buffer to fill in with name of listener
1469 * @len: size of the buffer
 
1470 *
1471 * Fills in socket name and returns positive length of name if successful.
1472 * Name is terminated with '\n'.  On error, returns a negative errno
1473 * value.
1474 */
1475int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
1476		const size_t len)
1477{
1478	int err = 0;
1479	struct socket *so = sockfd_lookup(fd, &err);
1480	struct svc_sock *svsk = NULL;
1481	struct sockaddr_storage addr;
1482	struct sockaddr *sin = (struct sockaddr *)&addr;
1483	int salen;
1484
1485	if (!so)
1486		return err;
1487	err = -EAFNOSUPPORT;
1488	if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1489		goto out;
1490	err =  -EPROTONOSUPPORT;
1491	if (so->sk->sk_protocol != IPPROTO_TCP &&
1492	    so->sk->sk_protocol != IPPROTO_UDP)
1493		goto out;
1494	err = -EISCONN;
1495	if (so->state > SS_UNCONNECTED)
1496		goto out;
1497	err = -ENOENT;
1498	if (!try_module_get(THIS_MODULE))
1499		goto out;
1500	svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
1501	if (IS_ERR(svsk)) {
1502		module_put(THIS_MODULE);
1503		err = PTR_ERR(svsk);
1504		goto out;
1505	}
1506	if (kernel_getsockname(svsk->sk_sock, sin, &salen) == 0)
 
1507		svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
 
1508	svc_add_new_perm_xprt(serv, &svsk->sk_xprt);
1509	return svc_one_sock_name(svsk, name_return, len);
1510out:
1511	sockfd_put(so);
1512	return err;
1513}
1514EXPORT_SYMBOL_GPL(svc_addsock);
1515
1516/*
1517 * Create socket for RPC service.
1518 */
1519static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1520					  int protocol,
1521					  struct net *net,
1522					  struct sockaddr *sin, int len,
1523					  int flags)
1524{
1525	struct svc_sock	*svsk;
1526	struct socket	*sock;
1527	int		error;
1528	int		type;
1529	struct sockaddr_storage addr;
1530	struct sockaddr *newsin = (struct sockaddr *)&addr;
1531	int		newlen;
1532	int		family;
1533	int		val;
1534	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1535
1536	dprintk("svc: svc_create_socket(%s, %d, %s)\n",
1537			serv->sv_program->pg_name, protocol,
1538			__svc_print_addr(sin, buf, sizeof(buf)));
1539
1540	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1541		printk(KERN_WARNING "svc: only UDP and TCP "
1542				"sockets supported\n");
1543		return ERR_PTR(-EINVAL);
1544	}
1545
1546	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1547	switch (sin->sa_family) {
1548	case AF_INET6:
1549		family = PF_INET6;
1550		break;
1551	case AF_INET:
1552		family = PF_INET;
1553		break;
1554	default:
1555		return ERR_PTR(-EINVAL);
1556	}
1557
1558	error = __sock_create(net, family, type, protocol, &sock, 1);
1559	if (error < 0)
1560		return ERR_PTR(error);
1561
1562	svc_reclassify_socket(sock);
1563
1564	/*
1565	 * If this is an PF_INET6 listener, we want to avoid
1566	 * getting requests from IPv4 remotes.  Those should
1567	 * be shunted to a PF_INET listener via rpcbind.
1568	 */
1569	val = 1;
1570	if (family == PF_INET6)
1571		kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
1572					(char *)&val, sizeof(val));
1573
1574	if (type == SOCK_STREAM)
1575		sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
1576	error = kernel_bind(sock, sin, len);
1577	if (error < 0)
1578		goto bummer;
1579
1580	newlen = len;
1581	error = kernel_getsockname(sock, newsin, &newlen);
1582	if (error < 0)
1583		goto bummer;
 
1584
1585	if (protocol == IPPROTO_TCP) {
1586		if ((error = kernel_listen(sock, 64)) < 0)
1587			goto bummer;
1588	}
1589
1590	svsk = svc_setup_socket(serv, sock, flags);
1591	if (IS_ERR(svsk)) {
1592		error = PTR_ERR(svsk);
1593		goto bummer;
1594	}
1595	svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
1596	return (struct svc_xprt *)svsk;
1597bummer:
1598	dprintk("svc: svc_create_socket error = %d\n", -error);
1599	sock_release(sock);
1600	return ERR_PTR(error);
1601}
1602
1603/*
1604 * Detach the svc_sock from the socket so that no
1605 * more callbacks occur.
1606 */
1607static void svc_sock_detach(struct svc_xprt *xprt)
1608{
1609	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1610	struct sock *sk = svsk->sk_sk;
1611	wait_queue_head_t *wq;
1612
1613	dprintk("svc: svc_sock_detach(%p)\n", svsk);
1614
1615	/* put back the old socket callbacks */
 
1616	sk->sk_state_change = svsk->sk_ostate;
1617	sk->sk_data_ready = svsk->sk_odata;
1618	sk->sk_write_space = svsk->sk_owspace;
1619
1620	wq = sk_sleep(sk);
1621	if (sunrpc_waitqueue_active(wq))
1622		wake_up_interruptible(wq);
1623}
1624
1625/*
1626 * Disconnect the socket, and reset the callbacks
1627 */
1628static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1629{
1630	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1631
1632	dprintk("svc: svc_tcp_sock_detach(%p)\n", svsk);
1633
1634	svc_sock_detach(xprt);
1635
1636	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
1637		svc_tcp_clear_pages(svsk);
1638		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
1639	}
1640}
1641
1642/*
1643 * Free the svc_sock's socket resources and the svc_sock itself.
1644 */
1645static void svc_sock_free(struct svc_xprt *xprt)
1646{
1647	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1648	dprintk("svc: svc_sock_free(%p)\n", svsk);
1649
1650	if (svsk->sk_sock->file)
1651		sockfd_put(svsk->sk_sock);
1652	else
1653		sock_release(svsk->sk_sock);
1654	kfree(svsk);
1655}
1656
1657#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1658/*
1659 * Create a back channel svc_xprt which shares the fore channel socket.
1660 */
1661static struct svc_xprt *svc_bc_create_socket(struct svc_serv *serv,
1662					     int protocol,
1663					     struct net *net,
1664					     struct sockaddr *sin, int len,
1665					     int flags)
1666{
1667	struct svc_sock *svsk;
1668	struct svc_xprt *xprt;
1669
1670	if (protocol != IPPROTO_TCP) {
1671		printk(KERN_WARNING "svc: only TCP sockets"
1672			" supported on shared back channel\n");
1673		return ERR_PTR(-EINVAL);
1674	}
1675
1676	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1677	if (!svsk)
1678		return ERR_PTR(-ENOMEM);
1679
1680	xprt = &svsk->sk_xprt;
1681	svc_xprt_init(net, &svc_tcp_bc_class, xprt, serv);
1682
1683	serv->sv_bc_xprt = xprt;
1684
1685	return xprt;
1686}
1687
1688/*
1689 * Free a back channel svc_sock.
1690 */
1691static void svc_bc_sock_free(struct svc_xprt *xprt)
1692{
1693	if (xprt)
1694		kfree(container_of(xprt, struct svc_sock, sk_xprt));
1695}
1696#endif /* CONFIG_SUNRPC_BACKCHANNEL */
v6.2
   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 <linux/highmem.h>
  48#include <asm/ioctls.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 <trace/events/sunrpc.h>
  59
  60#include "socklib.h"
  61#include "sunrpc.h"
  62
  63#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
  64
  65
  66static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
  67					 int flags);
 
  68static int		svc_udp_recvfrom(struct svc_rqst *);
  69static int		svc_udp_sendto(struct svc_rqst *);
  70static void		svc_sock_detach(struct svc_xprt *);
  71static void		svc_tcp_sock_detach(struct svc_xprt *);
  72static void		svc_sock_free(struct svc_xprt *);
  73
  74static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
  75					  struct net *, struct sockaddr *,
  76					  int, int);
 
 
 
 
 
 
 
  77#ifdef CONFIG_DEBUG_LOCK_ALLOC
  78static struct lock_class_key svc_key[2];
  79static struct lock_class_key svc_slock_key[2];
  80
  81static void svc_reclassify_socket(struct socket *sock)
  82{
  83	struct sock *sk = sock->sk;
  84
  85	if (WARN_ON_ONCE(!sock_allow_reclassification(sk)))
 
  86		return;
  87
  88	switch (sk->sk_family) {
  89	case AF_INET:
  90		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
  91					      &svc_slock_key[0],
  92					      "sk_xprt.xpt_lock-AF_INET-NFSD",
  93					      &svc_key[0]);
  94		break;
  95
  96	case AF_INET6:
  97		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
  98					      &svc_slock_key[1],
  99					      "sk_xprt.xpt_lock-AF_INET6-NFSD",
 100					      &svc_key[1]);
 101		break;
 102
 103	default:
 104		BUG();
 105	}
 106}
 107#else
 108static void svc_reclassify_socket(struct socket *sock)
 109{
 110}
 111#endif
 112
 113/**
 114 * svc_tcp_release_rqst - Release transport-related resources
 115 * @rqstp: request structure with resources to be released
 116 *
 117 */
 118static void svc_tcp_release_rqst(struct svc_rqst *rqstp)
 119{
 120}
 121
 122/**
 123 * svc_udp_release_rqst - Release transport-related resources
 124 * @rqstp: request structure with resources to be released
 125 *
 126 */
 127static void svc_udp_release_rqst(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		consume_skb(skb);
 
 
 134	}
 135}
 136
 137union svc_pktinfo_u {
 138	struct in_pktinfo pkti;
 139	struct in6_pktinfo pkti6;
 140};
 141#define SVC_PKTINFO_SPACE \
 142	CMSG_SPACE(sizeof(union svc_pktinfo_u))
 143
 144static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
 145{
 146	struct svc_sock *svsk =
 147		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 148	switch (svsk->sk_sk->sk_family) {
 149	case AF_INET: {
 150			struct in_pktinfo *pki = CMSG_DATA(cmh);
 151
 152			cmh->cmsg_level = SOL_IP;
 153			cmh->cmsg_type = IP_PKTINFO;
 154			pki->ipi_ifindex = 0;
 155			pki->ipi_spec_dst.s_addr =
 156				 svc_daddr_in(rqstp)->sin_addr.s_addr;
 157			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 158		}
 159		break;
 160
 161	case AF_INET6: {
 162			struct in6_pktinfo *pki = CMSG_DATA(cmh);
 163			struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 164
 165			cmh->cmsg_level = SOL_IPV6;
 166			cmh->cmsg_type = IPV6_PKTINFO;
 167			pki->ipi6_ifindex = daddr->sin6_scope_id;
 168			pki->ipi6_addr = daddr->sin6_addr;
 169			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
 170		}
 171		break;
 172	}
 173}
 174
 175static int svc_sock_result_payload(struct svc_rqst *rqstp, unsigned int offset,
 176				   unsigned int length)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 177{
 178	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 179}
 180
 181/*
 182 * Report socket names for nfsdfs
 183 */
 184static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
 185{
 186	const struct sock *sk = svsk->sk_sk;
 187	const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
 188							"udp" : "tcp";
 189	int len;
 190
 191	switch (sk->sk_family) {
 192	case PF_INET:
 193		len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
 194				proto_name,
 195				&inet_sk(sk)->inet_rcv_saddr,
 196				inet_sk(sk)->inet_num);
 197		break;
 198#if IS_ENABLED(CONFIG_IPV6)
 199	case PF_INET6:
 200		len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
 201				proto_name,
 202				&sk->sk_v6_rcv_saddr,
 203				inet_sk(sk)->inet_num);
 204		break;
 205#endif
 206	default:
 207		len = snprintf(buf, remaining, "*unknown-%d*\n",
 208				sk->sk_family);
 209	}
 210
 211	if (len >= remaining) {
 212		*buf = '\0';
 213		return -ENAMETOOLONG;
 214	}
 215	return len;
 216}
 217
 218#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 219static void svc_flush_bvec(const struct bio_vec *bvec, size_t size, size_t seek)
 220{
 221	struct bvec_iter bi = {
 222		.bi_size	= size + seek,
 223	};
 224	struct bio_vec bv;
 225
 226	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
 227	for_each_bvec(bv, bvec, bi, bi)
 228		flush_dcache_page(bv.bv_page);
 229}
 230#else
 231static inline void svc_flush_bvec(const struct bio_vec *bvec, size_t size,
 232				  size_t seek)
 233{
 234}
 235#endif
 236
 237/*
 238 * Read from @rqstp's transport socket. The incoming message fills whole
 239 * pages in @rqstp's rq_pages array until the last page of the message
 240 * has been received into a partial page.
 241 */
 242static ssize_t svc_tcp_read_msg(struct svc_rqst *rqstp, size_t buflen,
 243				size_t seek)
 244{
 245	struct svc_sock *svsk =
 246		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 247	struct bio_vec *bvec = rqstp->rq_bvec;
 248	struct msghdr msg = { NULL };
 249	unsigned int i;
 250	ssize_t len;
 251	size_t t;
 
 252
 253	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 254
 255	for (i = 0, t = 0; t < buflen; i++, t += PAGE_SIZE) {
 256		bvec[i].bv_page = rqstp->rq_pages[i];
 257		bvec[i].bv_len = PAGE_SIZE;
 258		bvec[i].bv_offset = 0;
 259	}
 260	rqstp->rq_respages = &rqstp->rq_pages[i];
 261	rqstp->rq_next_page = rqstp->rq_respages + 1;
 262
 263	iov_iter_bvec(&msg.msg_iter, ITER_DEST, bvec, i, buflen);
 264	if (seek) {
 265		iov_iter_advance(&msg.msg_iter, seek);
 266		buflen -= seek;
 267	}
 268	len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
 269	if (len > 0)
 270		svc_flush_bvec(bvec, len, seek);
 271
 272	/* If we read a full record, then assume there may be more
 273	 * data to read (stream based sockets only!)
 274	 */
 275	if (len == buflen)
 276		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 277
 
 
 278	return len;
 279}
 280
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 281/*
 282 * Set socket snd and rcv buffer lengths
 283 */
 284static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
 
 285{
 286	unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg;
 287	struct socket *sock = svsk->sk_sock;
 288
 289	nreqs = min(nreqs, INT_MAX / 2 / max_mesg);
 290
 
 
 
 
 
 
 
 
 291	lock_sock(sock->sk);
 292	sock->sk->sk_sndbuf = nreqs * max_mesg * 2;
 293	sock->sk->sk_rcvbuf = nreqs * max_mesg * 2;
 294	sock->sk->sk_write_space(sock->sk);
 295	release_sock(sock->sk);
 
 296}
 297
 298static void svc_sock_secure_port(struct svc_rqst *rqstp)
 299{
 300	if (svc_port_is_privileged(svc_addr(rqstp)))
 301		set_bit(RQ_SECURE, &rqstp->rq_flags);
 302	else
 303		clear_bit(RQ_SECURE, &rqstp->rq_flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 304}
 305
 306/*
 307 * INET callback when data has been received on the socket.
 308 */
 309static void svc_data_ready(struct sock *sk)
 310{
 311	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 
 312
 313	if (svsk) {
 314		/* Refer to svc_setup_socket() for details. */
 315		rmb();
 316		svsk->sk_odata(sk);
 317		trace_svcsock_data_ready(&svsk->sk_xprt, 0);
 318		if (!test_and_set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags))
 319			svc_xprt_enqueue(&svsk->sk_xprt);
 320	}
 
 
 321}
 322
 323/*
 324 * INET callback when space is newly available on the socket.
 325 */
 326static void svc_write_space(struct sock *sk)
 327{
 328	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
 
 329
 330	if (svsk) {
 331		/* Refer to svc_setup_socket() for details. */
 332		rmb();
 333		trace_svcsock_write_space(&svsk->sk_xprt, 0);
 334		svsk->sk_owspace(sk);
 335		svc_xprt_enqueue(&svsk->sk_xprt);
 336	}
 
 
 
 
 
 
 337}
 338
 339static int svc_tcp_has_wspace(struct svc_xprt *xprt)
 340{
 341	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 
 
 342
 343	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
 344		return 1;
 345	return !test_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 346}
 347
 348static void svc_tcp_kill_temp_xprt(struct svc_xprt *xprt)
 349{
 350	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 351
 352	sock_no_linger(svsk->sk_sock->sk);
 
 353}
 354
 355/*
 356 * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
 357 */
 358static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
 359				     struct cmsghdr *cmh)
 360{
 361	struct in_pktinfo *pki = CMSG_DATA(cmh);
 362	struct sockaddr_in *daddr = svc_daddr_in(rqstp);
 363
 364	if (cmh->cmsg_type != IP_PKTINFO)
 365		return 0;
 366
 367	daddr->sin_family = AF_INET;
 368	daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr;
 369	return 1;
 370}
 371
 372/*
 373 * See net/ipv6/datagram.c : ip6_datagram_recv_ctl
 374 */
 375static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
 376				     struct cmsghdr *cmh)
 377{
 378	struct in6_pktinfo *pki = CMSG_DATA(cmh);
 379	struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp);
 380
 381	if (cmh->cmsg_type != IPV6_PKTINFO)
 382		return 0;
 383
 384	daddr->sin6_family = AF_INET6;
 385	daddr->sin6_addr = pki->ipi6_addr;
 386	daddr->sin6_scope_id = pki->ipi6_ifindex;
 387	return 1;
 388}
 389
 390/*
 391 * Copy the UDP datagram's destination address to the rqstp structure.
 392 * The 'destination' address in this case is the address to which the
 393 * peer sent the datagram, i.e. our local address. For multihomed
 394 * hosts, this can change from msg to msg. Note that only the IP
 395 * address changes, the port number should remain the same.
 396 */
 397static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
 398				    struct cmsghdr *cmh)
 399{
 400	switch (cmh->cmsg_level) {
 401	case SOL_IP:
 402		return svc_udp_get_dest_address4(rqstp, cmh);
 403	case SOL_IPV6:
 404		return svc_udp_get_dest_address6(rqstp, cmh);
 405	}
 406
 407	return 0;
 408}
 409
 410/**
 411 * svc_udp_recvfrom - Receive a datagram from a UDP socket.
 412 * @rqstp: request structure into which to receive an RPC Call
 413 *
 414 * Called in a loop when XPT_DATA has been set.
 415 *
 416 * Returns:
 417 *   On success, the number of bytes in a received RPC Call, or
 418 *   %0 if a complete RPC Call message was not ready to return
 419 */
 420static int svc_udp_recvfrom(struct svc_rqst *rqstp)
 421{
 422	struct svc_sock	*svsk =
 423		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 424	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 425	struct sk_buff	*skb;
 426	union {
 427		struct cmsghdr	hdr;
 428		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 429	} buffer;
 430	struct cmsghdr *cmh = &buffer.hdr;
 431	struct msghdr msg = {
 432		.msg_name = svc_addr(rqstp),
 433		.msg_control = cmh,
 434		.msg_controllen = sizeof(buffer),
 435		.msg_flags = MSG_DONTWAIT,
 436	};
 437	size_t len;
 438	int err;
 439
 440	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
 441	    /* udp sockets need large rcvbuf as all pending
 442	     * requests are still in that buffer.  sndbuf must
 443	     * also be large enough that there is enough space
 444	     * for one reply per thread.  We count all threads
 445	     * rather than threads in a particular pool, which
 446	     * provides an upper bound on the number of threads
 447	     * which will access the socket.
 448	     */
 449	    svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3);
 
 
 450
 451	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 
 452	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
 453			     0, 0, MSG_PEEK | MSG_DONTWAIT);
 454	if (err < 0)
 455		goto out_recv_err;
 456	skb = skb_recv_udp(svsk->sk_sk, MSG_DONTWAIT, &err);
 457	if (!skb)
 458		goto out_recv_err;
 459
 
 
 
 
 
 
 
 
 460	len = svc_addr_len(svc_addr(rqstp));
 461	rqstp->rq_addrlen = len;
 462	if (skb->tstamp == 0) {
 463		skb->tstamp = ktime_get_real();
 464		/* Don't enable netstamp, sunrpc doesn't
 465		   need that much accuracy */
 466	}
 467	sock_write_timestamp(svsk->sk_sk, skb->tstamp);
 468	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
 469
 470	len = skb->len;
 471	rqstp->rq_arg.len = len;
 472	trace_svcsock_udp_recv(&svsk->sk_xprt, len);
 473
 474	rqstp->rq_prot = IPPROTO_UDP;
 475
 476	if (!svc_udp_get_dest_address(rqstp, cmh))
 477		goto out_cmsg_err;
 
 
 
 478	rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp));
 479
 480	if (skb_is_nonlinear(skb)) {
 481		/* we have to copy */
 482		local_bh_disable();
 483		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb))
 484			goto out_bh_enable;
 
 
 
 485		local_bh_enable();
 486		consume_skb(skb);
 487	} else {
 488		/* we can use it in-place */
 489		rqstp->rq_arg.head[0].iov_base = skb->data;
 
 490		rqstp->rq_arg.head[0].iov_len = len;
 491		if (skb_checksum_complete(skb))
 492			goto out_free;
 493		rqstp->rq_xprt_ctxt = skb;
 494	}
 495
 496	rqstp->rq_arg.page_base = 0;
 497	if (len <= rqstp->rq_arg.head[0].iov_len) {
 498		rqstp->rq_arg.head[0].iov_len = len;
 499		rqstp->rq_arg.page_len = 0;
 500		rqstp->rq_respages = rqstp->rq_pages+1;
 501	} else {
 502		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
 503		rqstp->rq_respages = rqstp->rq_pages + 1 +
 504			DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
 505	}
 506	rqstp->rq_next_page = rqstp->rq_respages+1;
 507
 508	if (serv->sv_stats)
 509		serv->sv_stats->netudpcnt++;
 510
 511	svc_xprt_received(rqstp->rq_xprt);
 512	return len;
 513
 514out_recv_err:
 515	if (err != -EAGAIN) {
 516		/* possibly an icmp error */
 517		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 518	}
 519	trace_svcsock_udp_recv_err(&svsk->sk_xprt, err);
 520	goto out_clear_busy;
 521out_cmsg_err:
 522	net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n",
 523			     cmh->cmsg_level, cmh->cmsg_type);
 524	goto out_free;
 525out_bh_enable:
 526	local_bh_enable();
 527out_free:
 528	kfree_skb(skb);
 529out_clear_busy:
 530	svc_xprt_received(rqstp->rq_xprt);
 531	return 0;
 532}
 533
 534/**
 535 * svc_udp_sendto - Send out a reply on a UDP socket
 536 * @rqstp: completed svc_rqst
 537 *
 538 * xpt_mutex ensures @rqstp's whole message is written to the socket
 539 * without interruption.
 540 *
 541 * Returns the number of bytes sent, or a negative errno.
 542 */
 543static int svc_udp_sendto(struct svc_rqst *rqstp)
 544{
 545	struct svc_xprt *xprt = rqstp->rq_xprt;
 546	struct svc_sock	*svsk = container_of(xprt, struct svc_sock, sk_xprt);
 547	struct xdr_buf *xdr = &rqstp->rq_res;
 548	union {
 549		struct cmsghdr	hdr;
 550		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
 551	} buffer;
 552	struct cmsghdr *cmh = &buffer.hdr;
 553	struct msghdr msg = {
 554		.msg_name	= &rqstp->rq_addr,
 555		.msg_namelen	= rqstp->rq_addrlen,
 556		.msg_control	= cmh,
 557		.msg_controllen	= sizeof(buffer),
 558	};
 559	unsigned int sent;
 560	int err;
 561
 562	svc_udp_release_rqst(rqstp);
 
 
 
 563
 564	svc_set_cmsg_data(rqstp, cmh);
 
 565
 566	mutex_lock(&xprt->xpt_mutex);
 567
 568	if (svc_xprt_is_dead(xprt))
 569		goto out_notconn;
 570
 571	err = xdr_alloc_bvec(xdr, GFP_KERNEL);
 572	if (err < 0)
 573		goto out_unlock;
 574
 575	err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
 576	if (err == -ECONNREFUSED) {
 577		/* ICMP error on earlier request. */
 578		err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
 579	}
 580	xdr_free_bvec(xdr);
 581	trace_svcsock_udp_send(xprt, err);
 582out_unlock:
 583	mutex_unlock(&xprt->xpt_mutex);
 584	if (err < 0)
 585		return err;
 586	return sent;
 587
 588out_notconn:
 589	mutex_unlock(&xprt->xpt_mutex);
 590	return -ENOTCONN;
 591}
 592
 593static int svc_udp_has_wspace(struct svc_xprt *xprt)
 594{
 595	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 596	struct svc_serv	*serv = xprt->xpt_server;
 597	unsigned long required;
 598
 599	/*
 600	 * Set the SOCK_NOSPACE flag before checking the available
 601	 * sock space.
 602	 */
 603	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 604	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
 605	if (required*2 > sock_wspace(svsk->sk_sk))
 606		return 0;
 607	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
 608	return 1;
 609}
 610
 611static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
 612{
 613	BUG();
 614	return NULL;
 615}
 616
 617static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt)
 618{
 619}
 620
 621static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
 622				       struct net *net,
 623				       struct sockaddr *sa, int salen,
 624				       int flags)
 625{
 626	return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
 627}
 628
 629static const struct svc_xprt_ops svc_udp_ops = {
 630	.xpo_create = svc_udp_create,
 631	.xpo_recvfrom = svc_udp_recvfrom,
 632	.xpo_sendto = svc_udp_sendto,
 633	.xpo_result_payload = svc_sock_result_payload,
 634	.xpo_release_rqst = svc_udp_release_rqst,
 635	.xpo_detach = svc_sock_detach,
 636	.xpo_free = svc_sock_free,
 
 637	.xpo_has_wspace = svc_udp_has_wspace,
 638	.xpo_accept = svc_udp_accept,
 639	.xpo_secure_port = svc_sock_secure_port,
 640	.xpo_kill_temp_xprt = svc_udp_kill_temp_xprt,
 641};
 642
 643static struct svc_xprt_class svc_udp_class = {
 644	.xcl_name = "udp",
 645	.xcl_owner = THIS_MODULE,
 646	.xcl_ops = &svc_udp_ops,
 647	.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
 648	.xcl_ident = XPRT_TRANSPORT_UDP,
 649};
 650
 651static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
 652{
 
 
 653	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class,
 654		      &svsk->sk_xprt, serv);
 655	clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
 656	svsk->sk_sk->sk_data_ready = svc_data_ready;
 657	svsk->sk_sk->sk_write_space = svc_write_space;
 658
 659	/* initialise setting must have enough space to
 660	 * receive and respond to one request.
 661	 * svc_udp_recvfrom will re-adjust if necessary
 662	 */
 663	svc_sock_setbufsize(svsk, 3);
 
 
 664
 665	/* data might have come in before data_ready set up */
 666	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 667	set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
 668
 669	/* make sure we get destination address info */
 670	switch (svsk->sk_sk->sk_family) {
 671	case AF_INET:
 672		ip_sock_set_pktinfo(svsk->sk_sock->sk);
 
 673		break;
 674	case AF_INET6:
 675		ip6_sock_set_recvpktinfo(svsk->sk_sock->sk);
 
 676		break;
 677	default:
 678		BUG();
 679	}
 
 
 
 680}
 681
 682/*
 683 * A data_ready event on a listening socket means there's a connection
 684 * pending. Do not use state_change as a substitute for it.
 685 */
 686static void svc_tcp_listen_data_ready(struct sock *sk)
 687{
 688	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 
 689
 690	if (svsk) {
 691		/* Refer to svc_setup_socket() for details. */
 692		rmb();
 693		svsk->sk_odata(sk);
 694	}
 695
 696	/*
 697	 * This callback may called twice when a new connection
 698	 * is established as a child socket inherits everything
 699	 * from a parent LISTEN socket.
 700	 * 1) data_ready method of the parent socket will be called
 701	 *    when one of child sockets become ESTABLISHED.
 702	 * 2) data_ready method of the child socket may be called
 703	 *    when it receives data before the socket is accepted.
 704	 * In case of 2, we should ignore it silently.
 705	 */
 706	if (sk->sk_state == TCP_LISTEN) {
 707		if (svsk) {
 708			set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 709			svc_xprt_enqueue(&svsk->sk_xprt);
 710		}
 
 711	}
 
 
 
 
 712}
 713
 714/*
 715 * A state change on a connected socket means it's dying or dead.
 716 */
 717static void svc_tcp_state_change(struct sock *sk)
 718{
 719	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
 
 
 
 
 720
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 721	if (svsk) {
 722		/* Refer to svc_setup_socket() for details. */
 723		rmb();
 724		svsk->sk_ostate(sk);
 725		trace_svcsock_tcp_state(&svsk->sk_xprt, svsk->sk_sock);
 726		if (sk->sk_state != TCP_ESTABLISHED)
 727			svc_xprt_deferred_close(&svsk->sk_xprt);
 728	}
 
 
 729}
 730
 731/*
 732 * Accept a TCP connection
 733 */
 734static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
 735{
 736	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 737	struct sockaddr_storage addr;
 738	struct sockaddr	*sin = (struct sockaddr *) &addr;
 739	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 740	struct socket	*sock = svsk->sk_sock;
 741	struct socket	*newsock;
 742	struct svc_sock	*newsvsk;
 743	int		err, slen;
 
 744
 
 745	if (!sock)
 746		return NULL;
 747
 748	clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 749	err = kernel_accept(sock, &newsock, O_NONBLOCK);
 750	if (err < 0) {
 751		if (err == -ENOMEM)
 752			printk(KERN_WARNING "%s: no more sockets!\n",
 753			       serv->sv_name);
 754		else if (err != -EAGAIN)
 755			net_warn_ratelimited("%s: accept failed (err %d)!\n",
 756					     serv->sv_name, -err);
 757		trace_svcsock_accept_err(xprt, serv->sv_name, err);
 758		return NULL;
 759	}
 760	set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
 761
 762	err = kernel_getpeername(newsock, sin);
 763	if (err < 0) {
 764		trace_svcsock_getpeername_err(xprt, serv->sv_name, err);
 
 765		goto failed;		/* aborted connection or whatever */
 766	}
 767	slen = err;
 768
 769	/* Reset the inherited callbacks before calling svc_setup_socket */
 770	newsock->sk->sk_state_change = svsk->sk_ostate;
 771	newsock->sk->sk_data_ready = svsk->sk_odata;
 772	newsock->sk->sk_write_space = svsk->sk_owspace;
 
 
 
 
 
 
 
 773
 774	/* make sure that a write doesn't block forever when
 775	 * low on memory
 776	 */
 777	newsock->sk->sk_sndtimeo = HZ*30;
 778
 779	newsvsk = svc_setup_socket(serv, newsock,
 780				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY));
 781	if (IS_ERR(newsvsk))
 782		goto failed;
 783	svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
 784	err = kernel_getsockname(newsock, sin);
 785	slen = err;
 786	if (unlikely(err < 0))
 787		slen = offsetof(struct sockaddr, sa_data);
 
 788	svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
 789
 790	if (sock_is_loopback(newsock->sk))
 791		set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 792	else
 793		clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
 794	if (serv->sv_stats)
 795		serv->sv_stats->nettcpconn++;
 796
 797	return &newsvsk->sk_xprt;
 798
 799failed:
 800	sock_release(newsock);
 801	return NULL;
 802}
 803
 804static size_t svc_tcp_restore_pages(struct svc_sock *svsk,
 805				    struct svc_rqst *rqstp)
 806{
 807	size_t len = svsk->sk_datalen;
 808	unsigned int i, npages;
 809
 810	if (!len)
 811		return 0;
 
 812	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 813	for (i = 0; i < npages; i++) {
 814		if (rqstp->rq_pages[i] != NULL)
 815			put_page(rqstp->rq_pages[i]);
 816		BUG_ON(svsk->sk_pages[i] == NULL);
 817		rqstp->rq_pages[i] = svsk->sk_pages[i];
 818		svsk->sk_pages[i] = NULL;
 819	}
 820	rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]);
 821	return len;
 822}
 823
 824static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp)
 825{
 826	unsigned int i, len, npages;
 827
 828	if (svsk->sk_datalen == 0)
 829		return;
 830	len = svsk->sk_datalen;
 831	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 832	for (i = 0; i < npages; i++) {
 833		svsk->sk_pages[i] = rqstp->rq_pages[i];
 834		rqstp->rq_pages[i] = NULL;
 835	}
 836}
 837
 838static void svc_tcp_clear_pages(struct svc_sock *svsk)
 839{
 840	unsigned int i, len, npages;
 841
 842	if (svsk->sk_datalen == 0)
 843		goto out;
 844	len = svsk->sk_datalen;
 845	npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 846	for (i = 0; i < npages; i++) {
 847		if (svsk->sk_pages[i] == NULL) {
 848			WARN_ON_ONCE(1);
 849			continue;
 850		}
 851		put_page(svsk->sk_pages[i]);
 852		svsk->sk_pages[i] = NULL;
 853	}
 854out:
 855	svsk->sk_tcplen = 0;
 856	svsk->sk_datalen = 0;
 857}
 858
 859/*
 860 * Receive fragment record header into sk_marker.
 
 861 */
 862static ssize_t svc_tcp_read_marker(struct svc_sock *svsk,
 863				   struct svc_rqst *rqstp)
 864{
 865	ssize_t want, len;
 
 
 866
 867	/* If we haven't gotten the record length yet,
 868	 * get the next four bytes.
 869	 */
 870	if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
 871		struct msghdr	msg = { NULL };
 872		struct kvec	iov;
 873
 874		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
 875		iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen;
 876		iov.iov_len  = want;
 877		iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, want);
 878		len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT);
 879		if (len < 0)
 880			return len;
 881		svsk->sk_tcplen += len;
 
 882		if (len < want) {
 883			/* call again to read the remaining bytes */
 884			goto err_short;
 
 885		}
 886		trace_svcsock_marker(&svsk->sk_xprt, svsk->sk_marker);
 
 887		if (svc_sock_reclen(svsk) + svsk->sk_datalen >
 888		    svsk->sk_xprt.xpt_server->sv_max_mesg)
 889			goto err_too_large;
 
 
 
 890	}
 
 891	return svc_sock_reclen(svsk);
 892
 893err_too_large:
 894	net_notice_ratelimited("svc: %s %s RPC fragment too large: %d\n",
 895			       __func__, svsk->sk_xprt.xpt_server->sv_name,
 896			       svc_sock_reclen(svsk));
 897	svc_xprt_deferred_close(&svsk->sk_xprt);
 898err_short:
 899	return -EAGAIN;
 900}
 901
 902static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp)
 903{
 904	struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt;
 905	struct rpc_rqst *req = NULL;
 906	struct kvec *src, *dst;
 907	__be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
 908	__be32 xid;
 909	__be32 calldir;
 910
 911	xid = *p++;
 912	calldir = *p;
 913
 914	if (!bc_xprt)
 915		return -EAGAIN;
 916	spin_lock(&bc_xprt->queue_lock);
 917	req = xprt_lookup_rqst(bc_xprt, xid);
 918	if (!req)
 919		goto unlock_notfound;
 920
 921	memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf));
 922	/*
 923	 * XXX!: cheating for now!  Only copying HEAD.
 924	 * But we know this is good enough for now (in fact, for any
 925	 * callback reply in the forseeable future).
 926	 */
 927	dst = &req->rq_private_buf.head[0];
 928	src = &rqstp->rq_arg.head[0];
 929	if (dst->iov_len < src->iov_len)
 930		goto unlock_eagain; /* whatever; just giving up. */
 931	memcpy(dst->iov_base, src->iov_base, src->iov_len);
 932	xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len);
 933	rqstp->rq_arg.len = 0;
 934	spin_unlock(&bc_xprt->queue_lock);
 935	return 0;
 936unlock_notfound:
 937	printk(KERN_NOTICE
 938		"%s: Got unrecognized reply: "
 939		"calldir 0x%x xpt_bc_xprt %p xid %08x\n",
 940		__func__, ntohl(calldir),
 941		bc_xprt, ntohl(xid));
 942unlock_eagain:
 943	spin_unlock(&bc_xprt->queue_lock);
 944	return -EAGAIN;
 945}
 946
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 947static void svc_tcp_fragment_received(struct svc_sock *svsk)
 948{
 949	/* If we have more data, signal svc_xprt_enqueue() to try again */
 
 
 
 950	svsk->sk_tcplen = 0;
 951	svsk->sk_marker = xdr_zero;
 952}
 953
 954/**
 955 * svc_tcp_recvfrom - Receive data from a TCP socket
 956 * @rqstp: request structure into which to receive an RPC Call
 957 *
 958 * Called in a loop when XPT_DATA has been set.
 959 *
 960 * Read the 4-byte stream record marker, then use the record length
 961 * in that marker to set up exactly the resources needed to receive
 962 * the next RPC message into @rqstp.
 963 *
 964 * Returns:
 965 *   On success, the number of bytes in a received RPC Call, or
 966 *   %0 if a complete RPC Call message was not ready to return
 967 *
 968 * The zero return case handles partial receives and callback Replies.
 969 * The state of a partial receive is preserved in the svc_sock for
 970 * the next call to svc_tcp_recvfrom.
 971 */
 972static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 973{
 974	struct svc_sock	*svsk =
 975		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
 976	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
 977	size_t want, base;
 978	ssize_t len;
 
 979	__be32 *p;
 980	__be32 calldir;
 
 981
 982	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
 983	len = svc_tcp_read_marker(svsk, rqstp);
 
 
 
 
 984	if (len < 0)
 985		goto error;
 986
 987	base = svc_tcp_restore_pages(svsk, rqstp);
 988	want = len - (svsk->sk_tcplen - sizeof(rpc_fraghdr));
 989	len = svc_tcp_read_msg(rqstp, base + want, base);
 
 
 
 
 
 
 
 
 
 
 990	if (len >= 0) {
 991		trace_svcsock_tcp_recv(&svsk->sk_xprt, len);
 992		svsk->sk_tcplen += len;
 993		svsk->sk_datalen += len;
 994	}
 995	if (len != want || !svc_sock_final_rec(svsk))
 996		goto err_incomplete;
 997	if (svsk->sk_datalen < 8)
 998		goto err_nuts;
 
 
 
 
 
 
 
 
 
 
 
 
 
 999
1000	rqstp->rq_arg.len = svsk->sk_datalen;
1001	rqstp->rq_arg.page_base = 0;
1002	if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1003		rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1004		rqstp->rq_arg.page_len = 0;
1005	} else
1006		rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
1007
1008	rqstp->rq_xprt_ctxt   = NULL;
1009	rqstp->rq_prot	      = IPPROTO_TCP;
1010	if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
1011		set_bit(RQ_LOCAL, &rqstp->rq_flags);
1012	else
1013		clear_bit(RQ_LOCAL, &rqstp->rq_flags);
1014
1015	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
1016	calldir = p[1];
1017	if (calldir)
1018		len = receive_cb_reply(svsk, rqstp);
1019
1020	/* Reset TCP read info */
1021	svsk->sk_datalen = 0;
1022	svc_tcp_fragment_received(svsk);
1023
1024	if (len < 0)
1025		goto error;
1026
1027	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
1028	if (serv->sv_stats)
1029		serv->sv_stats->nettcpcnt++;
1030
1031	svc_xprt_received(rqstp->rq_xprt);
1032	return rqstp->rq_arg.len;
1033
1034err_incomplete:
1035	svc_tcp_save_pages(svsk, rqstp);
1036	if (len < 0 && len != -EAGAIN)
1037		goto err_delete;
1038	if (len == want)
1039		svc_tcp_fragment_received(svsk);
1040	else
1041		trace_svcsock_tcp_recv_short(&svsk->sk_xprt,
1042				svc_sock_reclen(svsk),
1043				svsk->sk_tcplen - sizeof(rpc_fraghdr));
1044	goto err_noclose;
1045error:
1046	if (len != -EAGAIN)
1047		goto err_delete;
1048	trace_svcsock_tcp_recv_eagain(&svsk->sk_xprt, 0);
1049	goto err_noclose;
1050err_nuts:
1051	svsk->sk_datalen = 0;
1052err_delete:
1053	trace_svcsock_tcp_recv_err(&svsk->sk_xprt, len);
1054	svc_xprt_deferred_close(&svsk->sk_xprt);
 
1055err_noclose:
1056	svc_xprt_received(rqstp->rq_xprt);
1057	return 0;	/* record not complete */
1058}
1059
1060static int svc_tcp_send_kvec(struct socket *sock, const struct kvec *vec,
1061			      int flags)
 
 
1062{
1063	return kernel_sendpage(sock, virt_to_page(vec->iov_base),
1064			       offset_in_page(vec->iov_base),
1065			       vec->iov_len, flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1066}
1067
1068/*
1069 * kernel_sendpage() is used exclusively to reduce the number of
1070 * copy operations in this path. Therefore the caller must ensure
1071 * that the pages backing @xdr are unchanging.
1072 *
1073 * In addition, the logic assumes that * .bv_len is never larger
1074 * than PAGE_SIZE.
1075 */
1076static int svc_tcp_sendmsg(struct socket *sock, struct xdr_buf *xdr,
1077			   rpc_fraghdr marker, unsigned int *sentp)
1078{
1079	const struct kvec *head = xdr->head;
1080	const struct kvec *tail = xdr->tail;
1081	struct kvec rm = {
1082		.iov_base	= &marker,
1083		.iov_len	= sizeof(marker),
1084	};
1085	struct msghdr msg = {
1086		.msg_flags	= 0,
1087	};
1088	int ret;
1089
1090	*sentp = 0;
1091	ret = xdr_alloc_bvec(xdr, GFP_KERNEL);
1092	if (ret < 0)
1093		return ret;
1094
1095	ret = kernel_sendmsg(sock, &msg, &rm, 1, rm.iov_len);
1096	if (ret < 0)
1097		return ret;
1098	*sentp += ret;
1099	if (ret != rm.iov_len)
1100		return -EAGAIN;
1101
1102	ret = svc_tcp_send_kvec(sock, head, 0);
1103	if (ret < 0)
1104		return ret;
1105	*sentp += ret;
1106	if (ret != head->iov_len)
1107		goto out;
 
1108
1109	if (xdr->page_len) {
1110		unsigned int offset, len, remaining;
1111		struct bio_vec *bvec;
1112
1113		bvec = xdr->bvec + (xdr->page_base >> PAGE_SHIFT);
1114		offset = offset_in_page(xdr->page_base);
1115		remaining = xdr->page_len;
1116		while (remaining > 0) {
1117			len = min(remaining, bvec->bv_len - offset);
1118			ret = kernel_sendpage(sock, bvec->bv_page,
1119					      bvec->bv_offset + offset,
1120					      len, 0);
1121			if (ret < 0)
1122				return ret;
1123			*sentp += ret;
1124			if (ret != len)
1125				goto out;
1126			remaining -= len;
1127			offset = 0;
1128			bvec++;
1129		}
1130	}
1131
1132	if (tail->iov_len) {
1133		ret = svc_tcp_send_kvec(sock, tail, 0);
1134		if (ret < 0)
1135			return ret;
1136		*sentp += ret;
1137	}
 
1138
1139out:
1140	return 0;
1141}
1142
1143/**
1144 * svc_tcp_sendto - Send out a reply on a TCP socket
1145 * @rqstp: completed svc_rqst
1146 *
1147 * xpt_mutex ensures @rqstp's whole message is written to the socket
1148 * without interruption.
1149 *
1150 * Returns the number of bytes sent, or a negative errno.
1151 */
1152static int svc_tcp_sendto(struct svc_rqst *rqstp)
1153{
1154	struct svc_xprt *xprt = rqstp->rq_xprt;
1155	struct svc_sock	*svsk = container_of(xprt, struct svc_sock, sk_xprt);
1156	struct xdr_buf *xdr = &rqstp->rq_res;
1157	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
1158					 (u32)xdr->len);
1159	unsigned int sent;
1160	int err;
1161
1162	svc_tcp_release_rqst(rqstp);
 
 
 
 
 
1163
1164	atomic_inc(&svsk->sk_sendqlen);
1165	mutex_lock(&xprt->xpt_mutex);
1166	if (svc_xprt_is_dead(xprt))
1167		goto out_notconn;
1168	tcp_sock_set_cork(svsk->sk_sk, true);
1169	err = svc_tcp_sendmsg(svsk->sk_sock, xdr, marker, &sent);
1170	xdr_free_bvec(xdr);
1171	trace_svcsock_tcp_send(xprt, err < 0 ? (long)err : sent);
1172	if (err < 0 || sent != (xdr->len + sizeof(marker)))
1173		goto out_close;
1174	if (atomic_dec_and_test(&svsk->sk_sendqlen))
1175		tcp_sock_set_cork(svsk->sk_sk, false);
1176	mutex_unlock(&xprt->xpt_mutex);
1177	return sent;
1178
1179out_notconn:
1180	atomic_dec(&svsk->sk_sendqlen);
1181	mutex_unlock(&xprt->xpt_mutex);
1182	return -ENOTCONN;
1183out_close:
1184	pr_notice("rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
1185		  xprt->xpt_server->sv_name,
1186		  (err < 0) ? "got error" : "sent",
1187		  (err < 0) ? err : sent, xdr->len);
1188	svc_xprt_deferred_close(xprt);
1189	atomic_dec(&svsk->sk_sendqlen);
1190	mutex_unlock(&xprt->xpt_mutex);
1191	return -EAGAIN;
1192}
1193
1194static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1195				       struct net *net,
1196				       struct sockaddr *sa, int salen,
1197				       int flags)
1198{
1199	return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1200}
 
1201
1202static const struct svc_xprt_ops svc_tcp_ops = {
1203	.xpo_create = svc_tcp_create,
1204	.xpo_recvfrom = svc_tcp_recvfrom,
1205	.xpo_sendto = svc_tcp_sendto,
1206	.xpo_result_payload = svc_sock_result_payload,
1207	.xpo_release_rqst = svc_tcp_release_rqst,
1208	.xpo_detach = svc_tcp_sock_detach,
1209	.xpo_free = svc_sock_free,
 
1210	.xpo_has_wspace = svc_tcp_has_wspace,
1211	.xpo_accept = svc_tcp_accept,
1212	.xpo_secure_port = svc_sock_secure_port,
1213	.xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt,
1214};
1215
1216static struct svc_xprt_class svc_tcp_class = {
1217	.xcl_name = "tcp",
1218	.xcl_owner = THIS_MODULE,
1219	.xcl_ops = &svc_tcp_ops,
1220	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1221	.xcl_ident = XPRT_TRANSPORT_TCP,
1222};
1223
1224void svc_init_xprt_sock(void)
1225{
1226	svc_reg_xprt_class(&svc_tcp_class);
1227	svc_reg_xprt_class(&svc_udp_class);
 
1228}
1229
1230void svc_cleanup_xprt_sock(void)
1231{
1232	svc_unreg_xprt_class(&svc_tcp_class);
1233	svc_unreg_xprt_class(&svc_udp_class);
 
1234}
1235
1236static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1237{
1238	struct sock	*sk = svsk->sk_sk;
1239
1240	svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class,
1241		      &svsk->sk_xprt, serv);
1242	set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
1243	set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
1244	if (sk->sk_state == TCP_LISTEN) {
1245		strcpy(svsk->sk_xprt.xpt_remotebuf, "listener");
1246		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
1247		sk->sk_data_ready = svc_tcp_listen_data_ready;
1248		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
1249	} else {
 
1250		sk->sk_state_change = svc_tcp_state_change;
1251		sk->sk_data_ready = svc_data_ready;
1252		sk->sk_write_space = svc_write_space;
1253
1254		svsk->sk_marker = xdr_zero;
1255		svsk->sk_tcplen = 0;
1256		svsk->sk_datalen = 0;
1257		memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
1258
1259		tcp_sock_set_nodelay(sk);
1260
1261		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
1262		switch (sk->sk_state) {
1263		case TCP_SYN_RECV:
1264		case TCP_ESTABLISHED:
1265			break;
1266		default:
1267			svc_xprt_deferred_close(&svsk->sk_xprt);
1268		}
1269	}
1270}
1271
1272void svc_sock_update_bufs(struct svc_serv *serv)
1273{
1274	/*
1275	 * The number of server threads has changed. Update
1276	 * rcvbuf and sndbuf accordingly on all sockets
1277	 */
1278	struct svc_sock *svsk;
1279
1280	spin_lock_bh(&serv->sv_lock);
1281	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1282		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1283	spin_unlock_bh(&serv->sv_lock);
1284}
1285EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
1286
1287/*
1288 * Initialize socket for RPC use and create svc_sock struct
1289 */
1290static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1291						struct socket *sock,
1292						int flags)
1293{
1294	struct svc_sock	*svsk;
1295	struct sock	*inet;
1296	int		pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1297	int		err = 0;
1298
 
1299	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1300	if (!svsk)
1301		return ERR_PTR(-ENOMEM);
1302
1303	inet = sock->sk;
1304
1305	/* Register socket with portmapper */
1306	if (pmap_register)
1307		err = svc_register(serv, sock_net(sock->sk), inet->sk_family,
1308				     inet->sk_protocol,
1309				     ntohs(inet_sk(inet)->inet_sport));
1310
1311	if (err < 0) {
1312		kfree(svsk);
1313		return ERR_PTR(err);
1314	}
1315
 
1316	svsk->sk_sock = sock;
1317	svsk->sk_sk = inet;
1318	svsk->sk_ostate = inet->sk_state_change;
1319	svsk->sk_odata = inet->sk_data_ready;
1320	svsk->sk_owspace = inet->sk_write_space;
1321	/*
1322	 * This barrier is necessary in order to prevent race condition
1323	 * with svc_data_ready(), svc_listen_data_ready() and others
1324	 * when calling callbacks above.
1325	 */
1326	wmb();
1327	inet->sk_user_data = svsk;
1328
1329	/* Initialize the socket */
1330	if (sock->type == SOCK_DGRAM)
1331		svc_udp_init(svsk, serv);
1332	else
 
 
 
 
 
1333		svc_tcp_init(svsk, serv);
 
 
 
 
1334
1335	trace_svcsock_new_socket(sock);
1336	return svsk;
1337}
1338
1339bool svc_alien_sock(struct net *net, int fd)
1340{
1341	int err;
1342	struct socket *sock = sockfd_lookup(fd, &err);
1343	bool ret = false;
1344
1345	if (!sock)
1346		goto out;
1347	if (sock_net(sock->sk) != net)
1348		ret = true;
1349	sockfd_put(sock);
1350out:
1351	return ret;
1352}
1353EXPORT_SYMBOL_GPL(svc_alien_sock);
1354
1355/**
1356 * svc_addsock - add a listener socket to an RPC service
1357 * @serv: pointer to RPC service to which to add a new listener
1358 * @fd: file descriptor of the new listener
1359 * @name_return: pointer to buffer to fill in with name of listener
1360 * @len: size of the buffer
1361 * @cred: credential
1362 *
1363 * Fills in socket name and returns positive length of name if successful.
1364 * Name is terminated with '\n'.  On error, returns a negative errno
1365 * value.
1366 */
1367int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
1368		const size_t len, const struct cred *cred)
1369{
1370	int err = 0;
1371	struct socket *so = sockfd_lookup(fd, &err);
1372	struct svc_sock *svsk = NULL;
1373	struct sockaddr_storage addr;
1374	struct sockaddr *sin = (struct sockaddr *)&addr;
1375	int salen;
1376
1377	if (!so)
1378		return err;
1379	err = -EAFNOSUPPORT;
1380	if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1381		goto out;
1382	err =  -EPROTONOSUPPORT;
1383	if (so->sk->sk_protocol != IPPROTO_TCP &&
1384	    so->sk->sk_protocol != IPPROTO_UDP)
1385		goto out;
1386	err = -EISCONN;
1387	if (so->state > SS_UNCONNECTED)
1388		goto out;
1389	err = -ENOENT;
1390	if (!try_module_get(THIS_MODULE))
1391		goto out;
1392	svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS);
1393	if (IS_ERR(svsk)) {
1394		module_put(THIS_MODULE);
1395		err = PTR_ERR(svsk);
1396		goto out;
1397	}
1398	salen = kernel_getsockname(svsk->sk_sock, sin);
1399	if (salen >= 0)
1400		svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
1401	svsk->sk_xprt.xpt_cred = get_cred(cred);
1402	svc_add_new_perm_xprt(serv, &svsk->sk_xprt);
1403	return svc_one_sock_name(svsk, name_return, len);
1404out:
1405	sockfd_put(so);
1406	return err;
1407}
1408EXPORT_SYMBOL_GPL(svc_addsock);
1409
1410/*
1411 * Create socket for RPC service.
1412 */
1413static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1414					  int protocol,
1415					  struct net *net,
1416					  struct sockaddr *sin, int len,
1417					  int flags)
1418{
1419	struct svc_sock	*svsk;
1420	struct socket	*sock;
1421	int		error;
1422	int		type;
1423	struct sockaddr_storage addr;
1424	struct sockaddr *newsin = (struct sockaddr *)&addr;
1425	int		newlen;
1426	int		family;
 
 
 
 
 
 
1427
1428	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1429		printk(KERN_WARNING "svc: only UDP and TCP "
1430				"sockets supported\n");
1431		return ERR_PTR(-EINVAL);
1432	}
1433
1434	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1435	switch (sin->sa_family) {
1436	case AF_INET6:
1437		family = PF_INET6;
1438		break;
1439	case AF_INET:
1440		family = PF_INET;
1441		break;
1442	default:
1443		return ERR_PTR(-EINVAL);
1444	}
1445
1446	error = __sock_create(net, family, type, protocol, &sock, 1);
1447	if (error < 0)
1448		return ERR_PTR(error);
1449
1450	svc_reclassify_socket(sock);
1451
1452	/*
1453	 * If this is an PF_INET6 listener, we want to avoid
1454	 * getting requests from IPv4 remotes.  Those should
1455	 * be shunted to a PF_INET listener via rpcbind.
1456	 */
 
1457	if (family == PF_INET6)
1458		ip6_sock_set_v6only(sock->sk);
 
 
1459	if (type == SOCK_STREAM)
1460		sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */
1461	error = kernel_bind(sock, sin, len);
1462	if (error < 0)
1463		goto bummer;
1464
1465	error = kernel_getsockname(sock, newsin);
 
1466	if (error < 0)
1467		goto bummer;
1468	newlen = error;
1469
1470	if (protocol == IPPROTO_TCP) {
1471		if ((error = kernel_listen(sock, 64)) < 0)
1472			goto bummer;
1473	}
1474
1475	svsk = svc_setup_socket(serv, sock, flags);
1476	if (IS_ERR(svsk)) {
1477		error = PTR_ERR(svsk);
1478		goto bummer;
1479	}
1480	svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
1481	return (struct svc_xprt *)svsk;
1482bummer:
 
1483	sock_release(sock);
1484	return ERR_PTR(error);
1485}
1486
1487/*
1488 * Detach the svc_sock from the socket so that no
1489 * more callbacks occur.
1490 */
1491static void svc_sock_detach(struct svc_xprt *xprt)
1492{
1493	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1494	struct sock *sk = svsk->sk_sk;
 
 
 
1495
1496	/* put back the old socket callbacks */
1497	lock_sock(sk);
1498	sk->sk_state_change = svsk->sk_ostate;
1499	sk->sk_data_ready = svsk->sk_odata;
1500	sk->sk_write_space = svsk->sk_owspace;
1501	sk->sk_user_data = NULL;
1502	release_sock(sk);
 
 
1503}
1504
1505/*
1506 * Disconnect the socket, and reset the callbacks
1507 */
1508static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1509{
1510	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1511
 
 
1512	svc_sock_detach(xprt);
1513
1514	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
1515		svc_tcp_clear_pages(svsk);
1516		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
1517	}
1518}
1519
1520/*
1521 * Free the svc_sock's socket resources and the svc_sock itself.
1522 */
1523static void svc_sock_free(struct svc_xprt *xprt)
1524{
1525	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
 
1526
1527	if (svsk->sk_sock->file)
1528		sockfd_put(svsk->sk_sock);
1529	else
1530		sock_release(svsk->sk_sock);
1531	kfree(svsk);
1532}