xref: /linux/net/sunrpc/xprtsock.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/slab.h>
23 #include <linux/module.h>
24 #include <linux/capability.h>
25 #include <linux/pagemap.h>
26 #include <linux/errno.h>
27 #include <linux/socket.h>
28 #include <linux/in.h>
29 #include <linux/net.h>
30 #include <linux/mm.h>
31 #include <linux/udp.h>
32 #include <linux/tcp.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/sched.h>
35 #include <linux/sunrpc/xprtsock.h>
36 #include <linux/file.h>
37 
38 #include <net/sock.h>
39 #include <net/checksum.h>
40 #include <net/udp.h>
41 #include <net/tcp.h>
42 
43 /*
44  * xprtsock tunables
45  */
46 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
47 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
48 
49 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
50 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
51 
52 /*
53  * We can register our own files under /proc/sys/sunrpc by
54  * calling register_sysctl_table() again.  The files in that
55  * directory become the union of all files registered there.
56  *
57  * We simply need to make sure that we don't collide with
58  * someone else's file names!
59  */
60 
61 #ifdef RPC_DEBUG
62 
63 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
64 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
65 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
66 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
67 
68 static struct ctl_table_header *sunrpc_table_header;
69 
70 /*
71  * FIXME: changing the UDP slot table size should also resize the UDP
72  *        socket buffers for existing UDP transports
73  */
74 static ctl_table xs_tunables_table[] = {
75 	{
76 		.ctl_name	= CTL_SLOTTABLE_UDP,
77 		.procname	= "udp_slot_table_entries",
78 		.data		= &xprt_udp_slot_table_entries,
79 		.maxlen		= sizeof(unsigned int),
80 		.mode		= 0644,
81 		.proc_handler	= &proc_dointvec_minmax,
82 		.strategy	= &sysctl_intvec,
83 		.extra1		= &min_slot_table_size,
84 		.extra2		= &max_slot_table_size
85 	},
86 	{
87 		.ctl_name	= CTL_SLOTTABLE_TCP,
88 		.procname	= "tcp_slot_table_entries",
89 		.data		= &xprt_tcp_slot_table_entries,
90 		.maxlen		= sizeof(unsigned int),
91 		.mode		= 0644,
92 		.proc_handler	= &proc_dointvec_minmax,
93 		.strategy	= &sysctl_intvec,
94 		.extra1		= &min_slot_table_size,
95 		.extra2		= &max_slot_table_size
96 	},
97 	{
98 		.ctl_name	= CTL_MIN_RESVPORT,
99 		.procname	= "min_resvport",
100 		.data		= &xprt_min_resvport,
101 		.maxlen		= sizeof(unsigned int),
102 		.mode		= 0644,
103 		.proc_handler	= &proc_dointvec_minmax,
104 		.strategy	= &sysctl_intvec,
105 		.extra1		= &xprt_min_resvport_limit,
106 		.extra2		= &xprt_max_resvport_limit
107 	},
108 	{
109 		.ctl_name	= CTL_MAX_RESVPORT,
110 		.procname	= "max_resvport",
111 		.data		= &xprt_max_resvport,
112 		.maxlen		= sizeof(unsigned int),
113 		.mode		= 0644,
114 		.proc_handler	= &proc_dointvec_minmax,
115 		.strategy	= &sysctl_intvec,
116 		.extra1		= &xprt_min_resvport_limit,
117 		.extra2		= &xprt_max_resvport_limit
118 	},
119 	{
120 		.ctl_name = 0,
121 	},
122 };
123 
124 static ctl_table sunrpc_table[] = {
125 	{
126 		.ctl_name	= CTL_SUNRPC,
127 		.procname	= "sunrpc",
128 		.mode		= 0555,
129 		.child		= xs_tunables_table
130 	},
131 	{
132 		.ctl_name = 0,
133 	},
134 };
135 
136 #endif
137 
138 /*
139  * Time out for an RPC UDP socket connect.  UDP socket connects are
140  * synchronous, but we set a timeout anyway in case of resource
141  * exhaustion on the local host.
142  */
143 #define XS_UDP_CONN_TO		(5U * HZ)
144 
145 /*
146  * Wait duration for an RPC TCP connection to be established.  Solaris
147  * NFS over TCP uses 60 seconds, for example, which is in line with how
148  * long a server takes to reboot.
149  */
150 #define XS_TCP_CONN_TO		(60U * HZ)
151 
152 /*
153  * Wait duration for a reply from the RPC portmapper.
154  */
155 #define XS_BIND_TO		(60U * HZ)
156 
157 /*
158  * Delay if a UDP socket connect error occurs.  This is most likely some
159  * kind of resource problem on the local host.
160  */
161 #define XS_UDP_REEST_TO		(2U * HZ)
162 
163 /*
164  * The reestablish timeout allows clients to delay for a bit before attempting
165  * to reconnect to a server that just dropped our connection.
166  *
167  * We implement an exponential backoff when trying to reestablish a TCP
168  * transport connection with the server.  Some servers like to drop a TCP
169  * connection when they are overworked, so we start with a short timeout and
170  * increase over time if the server is down or not responding.
171  */
172 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
173 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
174 
175 /*
176  * TCP idle timeout; client drops the transport socket if it is idle
177  * for this long.  Note that we also timeout UDP sockets to prevent
178  * holding port numbers when there is no RPC traffic.
179  */
180 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
181 
182 #ifdef RPC_DEBUG
183 # undef  RPC_DEBUG_DATA
184 # define RPCDBG_FACILITY	RPCDBG_TRANS
185 #endif
186 
187 #ifdef RPC_DEBUG_DATA
188 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
189 {
190 	u8 *buf = (u8 *) packet;
191 	int j;
192 
193 	dprintk("RPC:       %s\n", msg);
194 	for (j = 0; j < count && j < 128; j += 4) {
195 		if (!(j & 31)) {
196 			if (j)
197 				dprintk("\n");
198 			dprintk("0x%04x ", j);
199 		}
200 		dprintk("%02x%02x%02x%02x ",
201 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
202 	}
203 	dprintk("\n");
204 }
205 #else
206 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
207 {
208 	/* NOP */
209 }
210 #endif
211 
212 struct sock_xprt {
213 	struct rpc_xprt		xprt;
214 
215 	/*
216 	 * Network layer
217 	 */
218 	struct socket *		sock;
219 	struct sock *		inet;
220 
221 	/*
222 	 * State of TCP reply receive
223 	 */
224 	__be32			tcp_fraghdr,
225 				tcp_xid;
226 
227 	u32			tcp_offset,
228 				tcp_reclen;
229 
230 	unsigned long		tcp_copied,
231 				tcp_flags;
232 
233 	/*
234 	 * Connection of transports
235 	 */
236 	struct delayed_work	connect_worker;
237 	struct sockaddr_storage	addr;
238 	unsigned short		port;
239 
240 	/*
241 	 * UDP socket buffer size parameters
242 	 */
243 	size_t			rcvsize,
244 				sndsize;
245 
246 	/*
247 	 * Saved socket callback addresses
248 	 */
249 	void			(*old_data_ready)(struct sock *, int);
250 	void			(*old_state_change)(struct sock *);
251 	void			(*old_write_space)(struct sock *);
252 	void			(*old_error_report)(struct sock *);
253 };
254 
255 /*
256  * TCP receive state flags
257  */
258 #define TCP_RCV_LAST_FRAG	(1UL << 0)
259 #define TCP_RCV_COPY_FRAGHDR	(1UL << 1)
260 #define TCP_RCV_COPY_XID	(1UL << 2)
261 #define TCP_RCV_COPY_DATA	(1UL << 3)
262 
263 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
264 {
265 	return (struct sockaddr *) &xprt->addr;
266 }
267 
268 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
269 {
270 	return (struct sockaddr_in *) &xprt->addr;
271 }
272 
273 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
274 {
275 	return (struct sockaddr_in6 *) &xprt->addr;
276 }
277 
278 static void xs_format_ipv4_peer_addresses(struct rpc_xprt *xprt,
279 					  const char *protocol,
280 					  const char *netid)
281 {
282 	struct sockaddr_in *addr = xs_addr_in(xprt);
283 	char *buf;
284 
285 	buf = kzalloc(20, GFP_KERNEL);
286 	if (buf) {
287 		snprintf(buf, 20, "%pI4", &addr->sin_addr.s_addr);
288 	}
289 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
290 
291 	buf = kzalloc(8, GFP_KERNEL);
292 	if (buf) {
293 		snprintf(buf, 8, "%u",
294 				ntohs(addr->sin_port));
295 	}
296 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
297 
298 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
299 
300 	buf = kzalloc(48, GFP_KERNEL);
301 	if (buf) {
302 		snprintf(buf, 48, "addr=%pI4 port=%u proto=%s",
303 			&addr->sin_addr.s_addr,
304 			ntohs(addr->sin_port),
305 			protocol);
306 	}
307 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
308 
309 	buf = kzalloc(10, GFP_KERNEL);
310 	if (buf) {
311 		snprintf(buf, 10, "%02x%02x%02x%02x",
312 				NIPQUAD(addr->sin_addr.s_addr));
313 	}
314 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
315 
316 	buf = kzalloc(8, GFP_KERNEL);
317 	if (buf) {
318 		snprintf(buf, 8, "%4hx",
319 				ntohs(addr->sin_port));
320 	}
321 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
322 
323 	buf = kzalloc(30, GFP_KERNEL);
324 	if (buf) {
325 		snprintf(buf, 30, "%pI4.%u.%u",
326 				&addr->sin_addr.s_addr,
327 				ntohs(addr->sin_port) >> 8,
328 				ntohs(addr->sin_port) & 0xff);
329 	}
330 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
331 
332 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
333 }
334 
335 static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt,
336 					  const char *protocol,
337 					  const char *netid)
338 {
339 	struct sockaddr_in6 *addr = xs_addr_in6(xprt);
340 	char *buf;
341 
342 	buf = kzalloc(40, GFP_KERNEL);
343 	if (buf) {
344 		snprintf(buf, 40, "%pI6",&addr->sin6_addr);
345 	}
346 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
347 
348 	buf = kzalloc(8, GFP_KERNEL);
349 	if (buf) {
350 		snprintf(buf, 8, "%u",
351 				ntohs(addr->sin6_port));
352 	}
353 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
354 
355 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
356 
357 	buf = kzalloc(64, GFP_KERNEL);
358 	if (buf) {
359 		snprintf(buf, 64, "addr=%pI6 port=%u proto=%s",
360 				&addr->sin6_addr,
361 				ntohs(addr->sin6_port),
362 				protocol);
363 	}
364 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
365 
366 	buf = kzalloc(36, GFP_KERNEL);
367 	if (buf)
368 		snprintf(buf, 36, "%pi6", &addr->sin6_addr);
369 
370 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
371 
372 	buf = kzalloc(8, GFP_KERNEL);
373 	if (buf) {
374 		snprintf(buf, 8, "%4hx",
375 				ntohs(addr->sin6_port));
376 	}
377 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
378 
379 	buf = kzalloc(50, GFP_KERNEL);
380 	if (buf) {
381 		snprintf(buf, 50, "%pI6.%u.%u",
382 			 &addr->sin6_addr,
383 			 ntohs(addr->sin6_port) >> 8,
384 			 ntohs(addr->sin6_port) & 0xff);
385 	}
386 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
387 
388 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
389 }
390 
391 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
392 {
393 	unsigned int i;
394 
395 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
396 		switch (i) {
397 		case RPC_DISPLAY_PROTO:
398 		case RPC_DISPLAY_NETID:
399 			continue;
400 		default:
401 			kfree(xprt->address_strings[i]);
402 		}
403 }
404 
405 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
406 
407 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
408 {
409 	struct msghdr msg = {
410 		.msg_name	= addr,
411 		.msg_namelen	= addrlen,
412 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
413 	};
414 	struct kvec iov = {
415 		.iov_base	= vec->iov_base + base,
416 		.iov_len	= vec->iov_len - base,
417 	};
418 
419 	if (iov.iov_len != 0)
420 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
421 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
422 }
423 
424 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
425 {
426 	struct page **ppage;
427 	unsigned int remainder;
428 	int err, sent = 0;
429 
430 	remainder = xdr->page_len - base;
431 	base += xdr->page_base;
432 	ppage = xdr->pages + (base >> PAGE_SHIFT);
433 	base &= ~PAGE_MASK;
434 	for(;;) {
435 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
436 		int flags = XS_SENDMSG_FLAGS;
437 
438 		remainder -= len;
439 		if (remainder != 0 || more)
440 			flags |= MSG_MORE;
441 		err = sock->ops->sendpage(sock, *ppage, base, len, flags);
442 		if (remainder == 0 || err != len)
443 			break;
444 		sent += err;
445 		ppage++;
446 		base = 0;
447 	}
448 	if (sent == 0)
449 		return err;
450 	if (err > 0)
451 		sent += err;
452 	return sent;
453 }
454 
455 /**
456  * xs_sendpages - write pages directly to a socket
457  * @sock: socket to send on
458  * @addr: UDP only -- address of destination
459  * @addrlen: UDP only -- length of destination address
460  * @xdr: buffer containing this request
461  * @base: starting position in the buffer
462  *
463  */
464 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
465 {
466 	unsigned int remainder = xdr->len - base;
467 	int err, sent = 0;
468 
469 	if (unlikely(!sock))
470 		return -ENOTCONN;
471 
472 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
473 	if (base != 0) {
474 		addr = NULL;
475 		addrlen = 0;
476 	}
477 
478 	if (base < xdr->head[0].iov_len || addr != NULL) {
479 		unsigned int len = xdr->head[0].iov_len - base;
480 		remainder -= len;
481 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
482 		if (remainder == 0 || err != len)
483 			goto out;
484 		sent += err;
485 		base = 0;
486 	} else
487 		base -= xdr->head[0].iov_len;
488 
489 	if (base < xdr->page_len) {
490 		unsigned int len = xdr->page_len - base;
491 		remainder -= len;
492 		err = xs_send_pagedata(sock, xdr, base, remainder != 0);
493 		if (remainder == 0 || err != len)
494 			goto out;
495 		sent += err;
496 		base = 0;
497 	} else
498 		base -= xdr->page_len;
499 
500 	if (base >= xdr->tail[0].iov_len)
501 		return sent;
502 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
503 out:
504 	if (sent == 0)
505 		return err;
506 	if (err > 0)
507 		sent += err;
508 	return sent;
509 }
510 
511 static void xs_nospace_callback(struct rpc_task *task)
512 {
513 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
514 
515 	transport->inet->sk_write_pending--;
516 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
517 }
518 
519 /**
520  * xs_nospace - place task on wait queue if transmit was incomplete
521  * @task: task to put to sleep
522  *
523  */
524 static void xs_nospace(struct rpc_task *task)
525 {
526 	struct rpc_rqst *req = task->tk_rqstp;
527 	struct rpc_xprt *xprt = req->rq_xprt;
528 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
529 
530 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
531 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
532 			req->rq_slen);
533 
534 	/* Protect against races with write_space */
535 	spin_lock_bh(&xprt->transport_lock);
536 
537 	/* Don't race with disconnect */
538 	if (xprt_connected(xprt)) {
539 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
540 			/*
541 			 * Notify TCP that we're limited by the application
542 			 * window size
543 			 */
544 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
545 			transport->inet->sk_write_pending++;
546 			/* ...and wait for more buffer space */
547 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
548 		}
549 	} else {
550 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
551 		task->tk_status = -ENOTCONN;
552 	}
553 
554 	spin_unlock_bh(&xprt->transport_lock);
555 }
556 
557 /**
558  * xs_udp_send_request - write an RPC request to a UDP socket
559  * @task: address of RPC task that manages the state of an RPC request
560  *
561  * Return values:
562  *        0:	The request has been sent
563  *   EAGAIN:	The socket was blocked, please call again later to
564  *		complete the request
565  * ENOTCONN:	Caller needs to invoke connect logic then call again
566  *    other:	Some other error occured, the request was not sent
567  */
568 static int xs_udp_send_request(struct rpc_task *task)
569 {
570 	struct rpc_rqst *req = task->tk_rqstp;
571 	struct rpc_xprt *xprt = req->rq_xprt;
572 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
573 	struct xdr_buf *xdr = &req->rq_snd_buf;
574 	int status;
575 
576 	xs_pktdump("packet data:",
577 				req->rq_svec->iov_base,
578 				req->rq_svec->iov_len);
579 
580 	status = xs_sendpages(transport->sock,
581 			      xs_addr(xprt),
582 			      xprt->addrlen, xdr,
583 			      req->rq_bytes_sent);
584 
585 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
586 			xdr->len - req->rq_bytes_sent, status);
587 
588 	if (status >= 0) {
589 		task->tk_bytes_sent += status;
590 		if (status >= req->rq_slen)
591 			return 0;
592 		/* Still some bytes left; set up for a retry later. */
593 		status = -EAGAIN;
594 	}
595 
596 	switch (status) {
597 	case -EAGAIN:
598 		xs_nospace(task);
599 		break;
600 	case -ENETUNREACH:
601 	case -EPIPE:
602 	case -ECONNREFUSED:
603 		/* When the server has died, an ICMP port unreachable message
604 		 * prompts ECONNREFUSED. */
605 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
606 		break;
607 	default:
608 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
609 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
610 			-status);
611 	}
612 
613 	return status;
614 }
615 
616 /**
617  * xs_tcp_shutdown - gracefully shut down a TCP socket
618  * @xprt: transport
619  *
620  * Initiates a graceful shutdown of the TCP socket by calling the
621  * equivalent of shutdown(SHUT_WR);
622  */
623 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
624 {
625 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
626 	struct socket *sock = transport->sock;
627 
628 	if (sock != NULL)
629 		kernel_sock_shutdown(sock, SHUT_WR);
630 }
631 
632 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
633 {
634 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
635 	rpc_fraghdr *base = buf->head[0].iov_base;
636 	*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
637 }
638 
639 /**
640  * xs_tcp_send_request - write an RPC request to a TCP socket
641  * @task: address of RPC task that manages the state of an RPC request
642  *
643  * Return values:
644  *        0:	The request has been sent
645  *   EAGAIN:	The socket was blocked, please call again later to
646  *		complete the request
647  * ENOTCONN:	Caller needs to invoke connect logic then call again
648  *    other:	Some other error occured, the request was not sent
649  *
650  * XXX: In the case of soft timeouts, should we eventually give up
651  *	if sendmsg is not able to make progress?
652  */
653 static int xs_tcp_send_request(struct rpc_task *task)
654 {
655 	struct rpc_rqst *req = task->tk_rqstp;
656 	struct rpc_xprt *xprt = req->rq_xprt;
657 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
658 	struct xdr_buf *xdr = &req->rq_snd_buf;
659 	int status;
660 
661 	xs_encode_tcp_record_marker(&req->rq_snd_buf);
662 
663 	xs_pktdump("packet data:",
664 				req->rq_svec->iov_base,
665 				req->rq_svec->iov_len);
666 
667 	/* Continue transmitting the packet/record. We must be careful
668 	 * to cope with writespace callbacks arriving _after_ we have
669 	 * called sendmsg(). */
670 	while (1) {
671 		status = xs_sendpages(transport->sock,
672 					NULL, 0, xdr, req->rq_bytes_sent);
673 
674 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
675 				xdr->len - req->rq_bytes_sent, status);
676 
677 		if (unlikely(status < 0))
678 			break;
679 
680 		/* If we've sent the entire packet, immediately
681 		 * reset the count of bytes sent. */
682 		req->rq_bytes_sent += status;
683 		task->tk_bytes_sent += status;
684 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
685 			req->rq_bytes_sent = 0;
686 			return 0;
687 		}
688 
689 		if (status != 0)
690 			continue;
691 		status = -EAGAIN;
692 		break;
693 	}
694 
695 	switch (status) {
696 	case -EAGAIN:
697 		xs_nospace(task);
698 		break;
699 	case -ECONNRESET:
700 		xs_tcp_shutdown(xprt);
701 	case -ECONNREFUSED:
702 	case -ENOTCONN:
703 	case -EPIPE:
704 		status = -ENOTCONN;
705 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
706 		break;
707 	default:
708 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
709 			-status);
710 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
711 		xs_tcp_shutdown(xprt);
712 	}
713 
714 	return status;
715 }
716 
717 /**
718  * xs_tcp_release_xprt - clean up after a tcp transmission
719  * @xprt: transport
720  * @task: rpc task
721  *
722  * This cleans up if an error causes us to abort the transmission of a request.
723  * In this case, the socket may need to be reset in order to avoid confusing
724  * the server.
725  */
726 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
727 {
728 	struct rpc_rqst *req;
729 
730 	if (task != xprt->snd_task)
731 		return;
732 	if (task == NULL)
733 		goto out_release;
734 	req = task->tk_rqstp;
735 	if (req->rq_bytes_sent == 0)
736 		goto out_release;
737 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
738 		goto out_release;
739 	set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
740 out_release:
741 	xprt_release_xprt(xprt, task);
742 }
743 
744 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
745 {
746 	transport->old_data_ready = sk->sk_data_ready;
747 	transport->old_state_change = sk->sk_state_change;
748 	transport->old_write_space = sk->sk_write_space;
749 	transport->old_error_report = sk->sk_error_report;
750 }
751 
752 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
753 {
754 	sk->sk_data_ready = transport->old_data_ready;
755 	sk->sk_state_change = transport->old_state_change;
756 	sk->sk_write_space = transport->old_write_space;
757 	sk->sk_error_report = transport->old_error_report;
758 }
759 
760 /**
761  * xs_close - close a socket
762  * @xprt: transport
763  *
764  * This is used when all requests are complete; ie, no DRC state remains
765  * on the server we want to save.
766  */
767 static void xs_close(struct rpc_xprt *xprt)
768 {
769 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
770 	struct socket *sock = transport->sock;
771 	struct sock *sk = transport->inet;
772 
773 	if (!sk)
774 		goto clear_close_wait;
775 
776 	dprintk("RPC:       xs_close xprt %p\n", xprt);
777 
778 	write_lock_bh(&sk->sk_callback_lock);
779 	transport->inet = NULL;
780 	transport->sock = NULL;
781 
782 	sk->sk_user_data = NULL;
783 
784 	xs_restore_old_callbacks(transport, sk);
785 	write_unlock_bh(&sk->sk_callback_lock);
786 
787 	sk->sk_no_check = 0;
788 
789 	sock_release(sock);
790 clear_close_wait:
791 	smp_mb__before_clear_bit();
792 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
793 	clear_bit(XPRT_CLOSING, &xprt->state);
794 	smp_mb__after_clear_bit();
795 	xprt_disconnect_done(xprt);
796 }
797 
798 /**
799  * xs_destroy - prepare to shutdown a transport
800  * @xprt: doomed transport
801  *
802  */
803 static void xs_destroy(struct rpc_xprt *xprt)
804 {
805 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
806 
807 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
808 
809 	cancel_rearming_delayed_work(&transport->connect_worker);
810 
811 	xs_close(xprt);
812 	xs_free_peer_addresses(xprt);
813 	kfree(xprt->slot);
814 	kfree(xprt);
815 	module_put(THIS_MODULE);
816 }
817 
818 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
819 {
820 	return (struct rpc_xprt *) sk->sk_user_data;
821 }
822 
823 /**
824  * xs_udp_data_ready - "data ready" callback for UDP sockets
825  * @sk: socket with data to read
826  * @len: how much data to read
827  *
828  */
829 static void xs_udp_data_ready(struct sock *sk, int len)
830 {
831 	struct rpc_task *task;
832 	struct rpc_xprt *xprt;
833 	struct rpc_rqst *rovr;
834 	struct sk_buff *skb;
835 	int err, repsize, copied;
836 	u32 _xid;
837 	__be32 *xp;
838 
839 	read_lock(&sk->sk_callback_lock);
840 	dprintk("RPC:       xs_udp_data_ready...\n");
841 	if (!(xprt = xprt_from_sock(sk)))
842 		goto out;
843 
844 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
845 		goto out;
846 
847 	if (xprt->shutdown)
848 		goto dropit;
849 
850 	repsize = skb->len - sizeof(struct udphdr);
851 	if (repsize < 4) {
852 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
853 		goto dropit;
854 	}
855 
856 	/* Copy the XID from the skb... */
857 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
858 				sizeof(_xid), &_xid);
859 	if (xp == NULL)
860 		goto dropit;
861 
862 	/* Look up and lock the request corresponding to the given XID */
863 	spin_lock(&xprt->transport_lock);
864 	rovr = xprt_lookup_rqst(xprt, *xp);
865 	if (!rovr)
866 		goto out_unlock;
867 	task = rovr->rq_task;
868 
869 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
870 		copied = repsize;
871 
872 	/* Suck it into the iovec, verify checksum if not done by hw. */
873 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
874 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
875 		goto out_unlock;
876 	}
877 
878 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
879 
880 	/* Something worked... */
881 	dst_confirm(skb->dst);
882 
883 	xprt_adjust_cwnd(task, copied);
884 	xprt_update_rtt(task);
885 	xprt_complete_rqst(task, copied);
886 
887  out_unlock:
888 	spin_unlock(&xprt->transport_lock);
889  dropit:
890 	skb_free_datagram(sk, skb);
891  out:
892 	read_unlock(&sk->sk_callback_lock);
893 }
894 
895 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
896 {
897 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
898 	size_t len, used;
899 	char *p;
900 
901 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
902 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
903 	used = xdr_skb_read_bits(desc, p, len);
904 	transport->tcp_offset += used;
905 	if (used != len)
906 		return;
907 
908 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
909 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
910 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
911 	else
912 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
913 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
914 
915 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
916 	transport->tcp_offset = 0;
917 
918 	/* Sanity check of the record length */
919 	if (unlikely(transport->tcp_reclen < 4)) {
920 		dprintk("RPC:       invalid TCP record fragment length\n");
921 		xprt_force_disconnect(xprt);
922 		return;
923 	}
924 	dprintk("RPC:       reading TCP record fragment of length %d\n",
925 			transport->tcp_reclen);
926 }
927 
928 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
929 {
930 	if (transport->tcp_offset == transport->tcp_reclen) {
931 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
932 		transport->tcp_offset = 0;
933 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
934 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
935 			transport->tcp_flags |= TCP_RCV_COPY_XID;
936 			transport->tcp_copied = 0;
937 		}
938 	}
939 }
940 
941 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
942 {
943 	size_t len, used;
944 	char *p;
945 
946 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
947 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
948 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
949 	used = xdr_skb_read_bits(desc, p, len);
950 	transport->tcp_offset += used;
951 	if (used != len)
952 		return;
953 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
954 	transport->tcp_flags |= TCP_RCV_COPY_DATA;
955 	transport->tcp_copied = 4;
956 	dprintk("RPC:       reading reply for XID %08x\n",
957 			ntohl(transport->tcp_xid));
958 	xs_tcp_check_fraghdr(transport);
959 }
960 
961 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
962 {
963 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
964 	struct rpc_rqst *req;
965 	struct xdr_buf *rcvbuf;
966 	size_t len;
967 	ssize_t r;
968 
969 	/* Find and lock the request corresponding to this xid */
970 	spin_lock(&xprt->transport_lock);
971 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
972 	if (!req) {
973 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
974 		dprintk("RPC:       XID %08x request not found!\n",
975 				ntohl(transport->tcp_xid));
976 		spin_unlock(&xprt->transport_lock);
977 		return;
978 	}
979 
980 	rcvbuf = &req->rq_private_buf;
981 	len = desc->count;
982 	if (len > transport->tcp_reclen - transport->tcp_offset) {
983 		struct xdr_skb_reader my_desc;
984 
985 		len = transport->tcp_reclen - transport->tcp_offset;
986 		memcpy(&my_desc, desc, sizeof(my_desc));
987 		my_desc.count = len;
988 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
989 					  &my_desc, xdr_skb_read_bits);
990 		desc->count -= r;
991 		desc->offset += r;
992 	} else
993 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
994 					  desc, xdr_skb_read_bits);
995 
996 	if (r > 0) {
997 		transport->tcp_copied += r;
998 		transport->tcp_offset += r;
999 	}
1000 	if (r != len) {
1001 		/* Error when copying to the receive buffer,
1002 		 * usually because we weren't able to allocate
1003 		 * additional buffer pages. All we can do now
1004 		 * is turn off TCP_RCV_COPY_DATA, so the request
1005 		 * will not receive any additional updates,
1006 		 * and time out.
1007 		 * Any remaining data from this record will
1008 		 * be discarded.
1009 		 */
1010 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1011 		dprintk("RPC:       XID %08x truncated request\n",
1012 				ntohl(transport->tcp_xid));
1013 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1014 				"tcp_offset = %u, tcp_reclen = %u\n",
1015 				xprt, transport->tcp_copied,
1016 				transport->tcp_offset, transport->tcp_reclen);
1017 		goto out;
1018 	}
1019 
1020 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1021 			ntohl(transport->tcp_xid), r);
1022 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1023 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1024 			transport->tcp_offset, transport->tcp_reclen);
1025 
1026 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1027 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1028 	else if (transport->tcp_offset == transport->tcp_reclen) {
1029 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1030 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1031 	}
1032 
1033 out:
1034 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1035 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1036 	spin_unlock(&xprt->transport_lock);
1037 	xs_tcp_check_fraghdr(transport);
1038 }
1039 
1040 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1041 {
1042 	size_t len;
1043 
1044 	len = transport->tcp_reclen - transport->tcp_offset;
1045 	if (len > desc->count)
1046 		len = desc->count;
1047 	desc->count -= len;
1048 	desc->offset += len;
1049 	transport->tcp_offset += len;
1050 	dprintk("RPC:       discarded %Zu bytes\n", len);
1051 	xs_tcp_check_fraghdr(transport);
1052 }
1053 
1054 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1055 {
1056 	struct rpc_xprt *xprt = rd_desc->arg.data;
1057 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1058 	struct xdr_skb_reader desc = {
1059 		.skb	= skb,
1060 		.offset	= offset,
1061 		.count	= len,
1062 	};
1063 
1064 	dprintk("RPC:       xs_tcp_data_recv started\n");
1065 	do {
1066 		/* Read in a new fragment marker if necessary */
1067 		/* Can we ever really expect to get completely empty fragments? */
1068 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1069 			xs_tcp_read_fraghdr(xprt, &desc);
1070 			continue;
1071 		}
1072 		/* Read in the xid if necessary */
1073 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1074 			xs_tcp_read_xid(transport, &desc);
1075 			continue;
1076 		}
1077 		/* Read in the request data */
1078 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1079 			xs_tcp_read_request(xprt, &desc);
1080 			continue;
1081 		}
1082 		/* Skip over any trailing bytes on short reads */
1083 		xs_tcp_read_discard(transport, &desc);
1084 	} while (desc.count);
1085 	dprintk("RPC:       xs_tcp_data_recv done\n");
1086 	return len - desc.count;
1087 }
1088 
1089 /**
1090  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1091  * @sk: socket with data to read
1092  * @bytes: how much data to read
1093  *
1094  */
1095 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1096 {
1097 	struct rpc_xprt *xprt;
1098 	read_descriptor_t rd_desc;
1099 	int read;
1100 
1101 	dprintk("RPC:       xs_tcp_data_ready...\n");
1102 
1103 	read_lock(&sk->sk_callback_lock);
1104 	if (!(xprt = xprt_from_sock(sk)))
1105 		goto out;
1106 	if (xprt->shutdown)
1107 		goto out;
1108 
1109 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1110 	rd_desc.arg.data = xprt;
1111 	do {
1112 		rd_desc.count = 65536;
1113 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1114 	} while (read > 0);
1115 out:
1116 	read_unlock(&sk->sk_callback_lock);
1117 }
1118 
1119 /**
1120  * xs_tcp_state_change - callback to handle TCP socket state changes
1121  * @sk: socket whose state has changed
1122  *
1123  */
1124 static void xs_tcp_state_change(struct sock *sk)
1125 {
1126 	struct rpc_xprt *xprt;
1127 
1128 	read_lock(&sk->sk_callback_lock);
1129 	if (!(xprt = xprt_from_sock(sk)))
1130 		goto out;
1131 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1132 	dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1133 			sk->sk_state, xprt_connected(xprt),
1134 			sock_flag(sk, SOCK_DEAD),
1135 			sock_flag(sk, SOCK_ZAPPED));
1136 
1137 	switch (sk->sk_state) {
1138 	case TCP_ESTABLISHED:
1139 		spin_lock_bh(&xprt->transport_lock);
1140 		if (!xprt_test_and_set_connected(xprt)) {
1141 			struct sock_xprt *transport = container_of(xprt,
1142 					struct sock_xprt, xprt);
1143 
1144 			/* Reset TCP record info */
1145 			transport->tcp_offset = 0;
1146 			transport->tcp_reclen = 0;
1147 			transport->tcp_copied = 0;
1148 			transport->tcp_flags =
1149 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1150 
1151 			xprt_wake_pending_tasks(xprt, 0);
1152 		}
1153 		spin_unlock_bh(&xprt->transport_lock);
1154 		break;
1155 	case TCP_FIN_WAIT1:
1156 		/* The client initiated a shutdown of the socket */
1157 		xprt->connect_cookie++;
1158 		xprt->reestablish_timeout = 0;
1159 		set_bit(XPRT_CLOSING, &xprt->state);
1160 		smp_mb__before_clear_bit();
1161 		clear_bit(XPRT_CONNECTED, &xprt->state);
1162 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1163 		smp_mb__after_clear_bit();
1164 		break;
1165 	case TCP_CLOSE_WAIT:
1166 		/* The server initiated a shutdown of the socket */
1167 		set_bit(XPRT_CLOSING, &xprt->state);
1168 		xprt_force_disconnect(xprt);
1169 	case TCP_SYN_SENT:
1170 		xprt->connect_cookie++;
1171 	case TCP_CLOSING:
1172 		/*
1173 		 * If the server closed down the connection, make sure that
1174 		 * we back off before reconnecting
1175 		 */
1176 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1177 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1178 		break;
1179 	case TCP_LAST_ACK:
1180 		smp_mb__before_clear_bit();
1181 		clear_bit(XPRT_CONNECTED, &xprt->state);
1182 		smp_mb__after_clear_bit();
1183 		break;
1184 	case TCP_CLOSE:
1185 		smp_mb__before_clear_bit();
1186 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1187 		clear_bit(XPRT_CLOSING, &xprt->state);
1188 		smp_mb__after_clear_bit();
1189 		/* Mark transport as closed and wake up all pending tasks */
1190 		xprt_disconnect_done(xprt);
1191 	}
1192  out:
1193 	read_unlock(&sk->sk_callback_lock);
1194 }
1195 
1196 /**
1197  * xs_tcp_error_report - callback mainly for catching RST events
1198  * @sk: socket
1199  */
1200 static void xs_tcp_error_report(struct sock *sk)
1201 {
1202 	struct rpc_xprt *xprt;
1203 
1204 	read_lock(&sk->sk_callback_lock);
1205 	if (sk->sk_err != ECONNRESET || sk->sk_state != TCP_ESTABLISHED)
1206 		goto out;
1207 	if (!(xprt = xprt_from_sock(sk)))
1208 		goto out;
1209 	dprintk("RPC:       %s client %p...\n"
1210 			"RPC:       error %d\n",
1211 			__func__, xprt, sk->sk_err);
1212 
1213 	xprt_force_disconnect(xprt);
1214 out:
1215 	read_unlock(&sk->sk_callback_lock);
1216 }
1217 
1218 /**
1219  * xs_udp_write_space - callback invoked when socket buffer space
1220  *                             becomes available
1221  * @sk: socket whose state has changed
1222  *
1223  * Called when more output buffer space is available for this socket.
1224  * We try not to wake our writers until they can make "significant"
1225  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1226  * with a bunch of small requests.
1227  */
1228 static void xs_udp_write_space(struct sock *sk)
1229 {
1230 	read_lock(&sk->sk_callback_lock);
1231 
1232 	/* from net/core/sock.c:sock_def_write_space */
1233 	if (sock_writeable(sk)) {
1234 		struct socket *sock;
1235 		struct rpc_xprt *xprt;
1236 
1237 		if (unlikely(!(sock = sk->sk_socket)))
1238 			goto out;
1239 		clear_bit(SOCK_NOSPACE, &sock->flags);
1240 
1241 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1242 			goto out;
1243 		if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1244 			goto out;
1245 
1246 		xprt_write_space(xprt);
1247 	}
1248 
1249  out:
1250 	read_unlock(&sk->sk_callback_lock);
1251 }
1252 
1253 /**
1254  * xs_tcp_write_space - callback invoked when socket buffer space
1255  *                             becomes available
1256  * @sk: socket whose state has changed
1257  *
1258  * Called when more output buffer space is available for this socket.
1259  * We try not to wake our writers until they can make "significant"
1260  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1261  * with a bunch of small requests.
1262  */
1263 static void xs_tcp_write_space(struct sock *sk)
1264 {
1265 	read_lock(&sk->sk_callback_lock);
1266 
1267 	/* from net/core/stream.c:sk_stream_write_space */
1268 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
1269 		struct socket *sock;
1270 		struct rpc_xprt *xprt;
1271 
1272 		if (unlikely(!(sock = sk->sk_socket)))
1273 			goto out;
1274 		clear_bit(SOCK_NOSPACE, &sock->flags);
1275 
1276 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1277 			goto out;
1278 		if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1279 			goto out;
1280 
1281 		xprt_write_space(xprt);
1282 	}
1283 
1284  out:
1285 	read_unlock(&sk->sk_callback_lock);
1286 }
1287 
1288 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1289 {
1290 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1291 	struct sock *sk = transport->inet;
1292 
1293 	if (transport->rcvsize) {
1294 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1295 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1296 	}
1297 	if (transport->sndsize) {
1298 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1299 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1300 		sk->sk_write_space(sk);
1301 	}
1302 }
1303 
1304 /**
1305  * xs_udp_set_buffer_size - set send and receive limits
1306  * @xprt: generic transport
1307  * @sndsize: requested size of send buffer, in bytes
1308  * @rcvsize: requested size of receive buffer, in bytes
1309  *
1310  * Set socket send and receive buffer size limits.
1311  */
1312 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1313 {
1314 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1315 
1316 	transport->sndsize = 0;
1317 	if (sndsize)
1318 		transport->sndsize = sndsize + 1024;
1319 	transport->rcvsize = 0;
1320 	if (rcvsize)
1321 		transport->rcvsize = rcvsize + 1024;
1322 
1323 	xs_udp_do_set_buffer_size(xprt);
1324 }
1325 
1326 /**
1327  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1328  * @task: task that timed out
1329  *
1330  * Adjust the congestion window after a retransmit timeout has occurred.
1331  */
1332 static void xs_udp_timer(struct rpc_task *task)
1333 {
1334 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1335 }
1336 
1337 static unsigned short xs_get_random_port(void)
1338 {
1339 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1340 	unsigned short rand = (unsigned short) net_random() % range;
1341 	return rand + xprt_min_resvport;
1342 }
1343 
1344 /**
1345  * xs_set_port - reset the port number in the remote endpoint address
1346  * @xprt: generic transport
1347  * @port: new port number
1348  *
1349  */
1350 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1351 {
1352 	struct sockaddr *addr = xs_addr(xprt);
1353 
1354 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1355 
1356 	switch (addr->sa_family) {
1357 	case AF_INET:
1358 		((struct sockaddr_in *)addr)->sin_port = htons(port);
1359 		break;
1360 	case AF_INET6:
1361 		((struct sockaddr_in6 *)addr)->sin6_port = htons(port);
1362 		break;
1363 	default:
1364 		BUG();
1365 	}
1366 }
1367 
1368 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1369 {
1370 	unsigned short port = transport->port;
1371 
1372 	if (port == 0 && transport->xprt.resvport)
1373 		port = xs_get_random_port();
1374 	return port;
1375 }
1376 
1377 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1378 {
1379 	if (transport->port != 0)
1380 		transport->port = 0;
1381 	if (!transport->xprt.resvport)
1382 		return 0;
1383 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1384 		return xprt_max_resvport;
1385 	return --port;
1386 }
1387 
1388 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1389 {
1390 	struct sockaddr_in myaddr = {
1391 		.sin_family = AF_INET,
1392 	};
1393 	struct sockaddr_in *sa;
1394 	int err, nloop = 0;
1395 	unsigned short port = xs_get_srcport(transport, sock);
1396 	unsigned short last;
1397 
1398 	sa = (struct sockaddr_in *)&transport->addr;
1399 	myaddr.sin_addr = sa->sin_addr;
1400 	do {
1401 		myaddr.sin_port = htons(port);
1402 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1403 						sizeof(myaddr));
1404 		if (port == 0)
1405 			break;
1406 		if (err == 0) {
1407 			transport->port = port;
1408 			break;
1409 		}
1410 		last = port;
1411 		port = xs_next_srcport(transport, sock, port);
1412 		if (port > last)
1413 			nloop++;
1414 	} while (err == -EADDRINUSE && nloop != 2);
1415 	dprintk("RPC:       %s %pI4:%u: %s (%d)\n",
1416 			__func__, &myaddr.sin_addr,
1417 			port, err ? "failed" : "ok", err);
1418 	return err;
1419 }
1420 
1421 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1422 {
1423 	struct sockaddr_in6 myaddr = {
1424 		.sin6_family = AF_INET6,
1425 	};
1426 	struct sockaddr_in6 *sa;
1427 	int err, nloop = 0;
1428 	unsigned short port = xs_get_srcport(transport, sock);
1429 	unsigned short last;
1430 
1431 	sa = (struct sockaddr_in6 *)&transport->addr;
1432 	myaddr.sin6_addr = sa->sin6_addr;
1433 	do {
1434 		myaddr.sin6_port = htons(port);
1435 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1436 						sizeof(myaddr));
1437 		if (port == 0)
1438 			break;
1439 		if (err == 0) {
1440 			transport->port = port;
1441 			break;
1442 		}
1443 		last = port;
1444 		port = xs_next_srcport(transport, sock, port);
1445 		if (port > last)
1446 			nloop++;
1447 	} while (err == -EADDRINUSE && nloop != 2);
1448 	dprintk("RPC:       xs_bind6 %pI6:%u: %s (%d)\n",
1449 		&myaddr.sin6_addr, port, err ? "failed" : "ok", err);
1450 	return err;
1451 }
1452 
1453 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1454 static struct lock_class_key xs_key[2];
1455 static struct lock_class_key xs_slock_key[2];
1456 
1457 static inline void xs_reclassify_socket4(struct socket *sock)
1458 {
1459 	struct sock *sk = sock->sk;
1460 
1461 	BUG_ON(sock_owned_by_user(sk));
1462 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1463 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1464 }
1465 
1466 static inline void xs_reclassify_socket6(struct socket *sock)
1467 {
1468 	struct sock *sk = sock->sk;
1469 
1470 	BUG_ON(sock_owned_by_user(sk));
1471 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1472 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1473 }
1474 #else
1475 static inline void xs_reclassify_socket4(struct socket *sock)
1476 {
1477 }
1478 
1479 static inline void xs_reclassify_socket6(struct socket *sock)
1480 {
1481 }
1482 #endif
1483 
1484 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1485 {
1486 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1487 
1488 	if (!transport->inet) {
1489 		struct sock *sk = sock->sk;
1490 
1491 		write_lock_bh(&sk->sk_callback_lock);
1492 
1493 		xs_save_old_callbacks(transport, sk);
1494 
1495 		sk->sk_user_data = xprt;
1496 		sk->sk_data_ready = xs_udp_data_ready;
1497 		sk->sk_write_space = xs_udp_write_space;
1498 		sk->sk_no_check = UDP_CSUM_NORCV;
1499 		sk->sk_allocation = GFP_ATOMIC;
1500 
1501 		xprt_set_connected(xprt);
1502 
1503 		/* Reset to new socket */
1504 		transport->sock = sock;
1505 		transport->inet = sk;
1506 
1507 		write_unlock_bh(&sk->sk_callback_lock);
1508 	}
1509 	xs_udp_do_set_buffer_size(xprt);
1510 }
1511 
1512 /**
1513  * xs_udp_connect_worker4 - set up a UDP socket
1514  * @work: RPC transport to connect
1515  *
1516  * Invoked by a work queue tasklet.
1517  */
1518 static void xs_udp_connect_worker4(struct work_struct *work)
1519 {
1520 	struct sock_xprt *transport =
1521 		container_of(work, struct sock_xprt, connect_worker.work);
1522 	struct rpc_xprt *xprt = &transport->xprt;
1523 	struct socket *sock = transport->sock;
1524 	int err, status = -EIO;
1525 
1526 	if (xprt->shutdown || !xprt_bound(xprt))
1527 		goto out;
1528 
1529 	/* Start by resetting any existing state */
1530 	xs_close(xprt);
1531 
1532 	if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1533 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1534 		goto out;
1535 	}
1536 	xs_reclassify_socket4(sock);
1537 
1538 	if (xs_bind4(transport, sock)) {
1539 		sock_release(sock);
1540 		goto out;
1541 	}
1542 
1543 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1544 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1545 
1546 	xs_udp_finish_connecting(xprt, sock);
1547 	status = 0;
1548 out:
1549 	xprt_wake_pending_tasks(xprt, status);
1550 	xprt_clear_connecting(xprt);
1551 }
1552 
1553 /**
1554  * xs_udp_connect_worker6 - set up a UDP socket
1555  * @work: RPC transport to connect
1556  *
1557  * Invoked by a work queue tasklet.
1558  */
1559 static void xs_udp_connect_worker6(struct work_struct *work)
1560 {
1561 	struct sock_xprt *transport =
1562 		container_of(work, struct sock_xprt, connect_worker.work);
1563 	struct rpc_xprt *xprt = &transport->xprt;
1564 	struct socket *sock = transport->sock;
1565 	int err, status = -EIO;
1566 
1567 	if (xprt->shutdown || !xprt_bound(xprt))
1568 		goto out;
1569 
1570 	/* Start by resetting any existing state */
1571 	xs_close(xprt);
1572 
1573 	if ((err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1574 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1575 		goto out;
1576 	}
1577 	xs_reclassify_socket6(sock);
1578 
1579 	if (xs_bind6(transport, sock) < 0) {
1580 		sock_release(sock);
1581 		goto out;
1582 	}
1583 
1584 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1585 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1586 
1587 	xs_udp_finish_connecting(xprt, sock);
1588 	status = 0;
1589 out:
1590 	xprt_wake_pending_tasks(xprt, status);
1591 	xprt_clear_connecting(xprt);
1592 }
1593 
1594 /*
1595  * We need to preserve the port number so the reply cache on the server can
1596  * find our cached RPC replies when we get around to reconnecting.
1597  */
1598 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1599 {
1600 	int result;
1601 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1602 	struct sockaddr any;
1603 
1604 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1605 
1606 	/*
1607 	 * Disconnect the transport socket by doing a connect operation
1608 	 * with AF_UNSPEC.  This should return immediately...
1609 	 */
1610 	memset(&any, 0, sizeof(any));
1611 	any.sa_family = AF_UNSPEC;
1612 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1613 	if (result)
1614 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1615 				result);
1616 }
1617 
1618 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1619 {
1620 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1621 
1622 	if (!transport->inet) {
1623 		struct sock *sk = sock->sk;
1624 
1625 		write_lock_bh(&sk->sk_callback_lock);
1626 
1627 		xs_save_old_callbacks(transport, sk);
1628 
1629 		sk->sk_user_data = xprt;
1630 		sk->sk_data_ready = xs_tcp_data_ready;
1631 		sk->sk_state_change = xs_tcp_state_change;
1632 		sk->sk_write_space = xs_tcp_write_space;
1633 		sk->sk_error_report = xs_tcp_error_report;
1634 		sk->sk_allocation = GFP_ATOMIC;
1635 
1636 		/* socket options */
1637 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1638 		sock_reset_flag(sk, SOCK_LINGER);
1639 		tcp_sk(sk)->linger2 = 0;
1640 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1641 
1642 		xprt_clear_connected(xprt);
1643 
1644 		/* Reset to new socket */
1645 		transport->sock = sock;
1646 		transport->inet = sk;
1647 
1648 		write_unlock_bh(&sk->sk_callback_lock);
1649 	}
1650 
1651 	/* Tell the socket layer to start connecting... */
1652 	xprt->stat.connect_count++;
1653 	xprt->stat.connect_start = jiffies;
1654 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1655 }
1656 
1657 /**
1658  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1659  * @work: RPC transport to connect
1660  *
1661  * Invoked by a work queue tasklet.
1662  */
1663 static void xs_tcp_connect_worker4(struct work_struct *work)
1664 {
1665 	struct sock_xprt *transport =
1666 		container_of(work, struct sock_xprt, connect_worker.work);
1667 	struct rpc_xprt *xprt = &transport->xprt;
1668 	struct socket *sock = transport->sock;
1669 	int err, status = -EIO;
1670 
1671 	if (xprt->shutdown || !xprt_bound(xprt))
1672 		goto out;
1673 
1674 	if (!sock) {
1675 		/* start from scratch */
1676 		if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1677 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1678 			goto out;
1679 		}
1680 		xs_reclassify_socket4(sock);
1681 
1682 		if (xs_bind4(transport, sock) < 0) {
1683 			sock_release(sock);
1684 			goto out;
1685 		}
1686 	} else
1687 		/* "close" the socket, preserving the local port */
1688 		xs_tcp_reuse_connection(xprt);
1689 
1690 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1691 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1692 
1693 	status = xs_tcp_finish_connecting(xprt, sock);
1694 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1695 			xprt, -status, xprt_connected(xprt),
1696 			sock->sk->sk_state);
1697 	if (status < 0) {
1698 		switch (status) {
1699 			case -EINPROGRESS:
1700 			case -EALREADY:
1701 				goto out_clear;
1702 			case -ECONNREFUSED:
1703 			case -ECONNRESET:
1704 				/* retry with existing socket, after a delay */
1705 				break;
1706 			default:
1707 				/* get rid of existing socket, and retry */
1708 				xs_tcp_shutdown(xprt);
1709 		}
1710 	}
1711 out:
1712 	xprt_wake_pending_tasks(xprt, status);
1713 out_clear:
1714 	xprt_clear_connecting(xprt);
1715 }
1716 
1717 /**
1718  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1719  * @work: RPC transport to connect
1720  *
1721  * Invoked by a work queue tasklet.
1722  */
1723 static void xs_tcp_connect_worker6(struct work_struct *work)
1724 {
1725 	struct sock_xprt *transport =
1726 		container_of(work, struct sock_xprt, connect_worker.work);
1727 	struct rpc_xprt *xprt = &transport->xprt;
1728 	struct socket *sock = transport->sock;
1729 	int err, status = -EIO;
1730 
1731 	if (xprt->shutdown || !xprt_bound(xprt))
1732 		goto out;
1733 
1734 	if (!sock) {
1735 		/* start from scratch */
1736 		if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1737 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1738 			goto out;
1739 		}
1740 		xs_reclassify_socket6(sock);
1741 
1742 		if (xs_bind6(transport, sock) < 0) {
1743 			sock_release(sock);
1744 			goto out;
1745 		}
1746 	} else
1747 		/* "close" the socket, preserving the local port */
1748 		xs_tcp_reuse_connection(xprt);
1749 
1750 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1751 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1752 
1753 	status = xs_tcp_finish_connecting(xprt, sock);
1754 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1755 			xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1756 	if (status < 0) {
1757 		switch (status) {
1758 			case -EINPROGRESS:
1759 			case -EALREADY:
1760 				goto out_clear;
1761 			case -ECONNREFUSED:
1762 			case -ECONNRESET:
1763 				/* retry with existing socket, after a delay */
1764 				break;
1765 			default:
1766 				/* get rid of existing socket, and retry */
1767 				xs_tcp_shutdown(xprt);
1768 		}
1769 	}
1770 out:
1771 	xprt_wake_pending_tasks(xprt, status);
1772 out_clear:
1773 	xprt_clear_connecting(xprt);
1774 }
1775 
1776 /**
1777  * xs_connect - connect a socket to a remote endpoint
1778  * @task: address of RPC task that manages state of connect request
1779  *
1780  * TCP: If the remote end dropped the connection, delay reconnecting.
1781  *
1782  * UDP socket connects are synchronous, but we use a work queue anyway
1783  * to guarantee that even unprivileged user processes can set up a
1784  * socket on a privileged port.
1785  *
1786  * If a UDP socket connect fails, the delay behavior here prevents
1787  * retry floods (hard mounts).
1788  */
1789 static void xs_connect(struct rpc_task *task)
1790 {
1791 	struct rpc_xprt *xprt = task->tk_xprt;
1792 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1793 
1794 	if (xprt_test_and_set_connecting(xprt))
1795 		return;
1796 
1797 	if (transport->sock != NULL) {
1798 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
1799 				"seconds\n",
1800 				xprt, xprt->reestablish_timeout / HZ);
1801 		queue_delayed_work(rpciod_workqueue,
1802 				   &transport->connect_worker,
1803 				   xprt->reestablish_timeout);
1804 		xprt->reestablish_timeout <<= 1;
1805 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1806 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1807 	} else {
1808 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
1809 		queue_delayed_work(rpciod_workqueue,
1810 				   &transport->connect_worker, 0);
1811 	}
1812 }
1813 
1814 static void xs_tcp_connect(struct rpc_task *task)
1815 {
1816 	struct rpc_xprt *xprt = task->tk_xprt;
1817 
1818 	/* Initiate graceful shutdown of the socket if not already done */
1819 	if (test_bit(XPRT_CONNECTED, &xprt->state))
1820 		xs_tcp_shutdown(xprt);
1821 	/* Exit if we need to wait for socket shutdown to complete */
1822 	if (test_bit(XPRT_CLOSING, &xprt->state))
1823 		return;
1824 	xs_connect(task);
1825 }
1826 
1827 /**
1828  * xs_udp_print_stats - display UDP socket-specifc stats
1829  * @xprt: rpc_xprt struct containing statistics
1830  * @seq: output file
1831  *
1832  */
1833 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1834 {
1835 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1836 
1837 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1838 			transport->port,
1839 			xprt->stat.bind_count,
1840 			xprt->stat.sends,
1841 			xprt->stat.recvs,
1842 			xprt->stat.bad_xids,
1843 			xprt->stat.req_u,
1844 			xprt->stat.bklog_u);
1845 }
1846 
1847 /**
1848  * xs_tcp_print_stats - display TCP socket-specifc stats
1849  * @xprt: rpc_xprt struct containing statistics
1850  * @seq: output file
1851  *
1852  */
1853 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1854 {
1855 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1856 	long idle_time = 0;
1857 
1858 	if (xprt_connected(xprt))
1859 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
1860 
1861 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1862 			transport->port,
1863 			xprt->stat.bind_count,
1864 			xprt->stat.connect_count,
1865 			xprt->stat.connect_time,
1866 			idle_time,
1867 			xprt->stat.sends,
1868 			xprt->stat.recvs,
1869 			xprt->stat.bad_xids,
1870 			xprt->stat.req_u,
1871 			xprt->stat.bklog_u);
1872 }
1873 
1874 static struct rpc_xprt_ops xs_udp_ops = {
1875 	.set_buffer_size	= xs_udp_set_buffer_size,
1876 	.reserve_xprt		= xprt_reserve_xprt_cong,
1877 	.release_xprt		= xprt_release_xprt_cong,
1878 	.rpcbind		= rpcb_getport_async,
1879 	.set_port		= xs_set_port,
1880 	.connect		= xs_connect,
1881 	.buf_alloc		= rpc_malloc,
1882 	.buf_free		= rpc_free,
1883 	.send_request		= xs_udp_send_request,
1884 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
1885 	.timer			= xs_udp_timer,
1886 	.release_request	= xprt_release_rqst_cong,
1887 	.close			= xs_close,
1888 	.destroy		= xs_destroy,
1889 	.print_stats		= xs_udp_print_stats,
1890 };
1891 
1892 static struct rpc_xprt_ops xs_tcp_ops = {
1893 	.reserve_xprt		= xprt_reserve_xprt,
1894 	.release_xprt		= xs_tcp_release_xprt,
1895 	.rpcbind		= rpcb_getport_async,
1896 	.set_port		= xs_set_port,
1897 	.connect		= xs_tcp_connect,
1898 	.buf_alloc		= rpc_malloc,
1899 	.buf_free		= rpc_free,
1900 	.send_request		= xs_tcp_send_request,
1901 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
1902 	.close			= xs_tcp_shutdown,
1903 	.destroy		= xs_destroy,
1904 	.print_stats		= xs_tcp_print_stats,
1905 };
1906 
1907 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
1908 				      unsigned int slot_table_size)
1909 {
1910 	struct rpc_xprt *xprt;
1911 	struct sock_xprt *new;
1912 
1913 	if (args->addrlen > sizeof(xprt->addr)) {
1914 		dprintk("RPC:       xs_setup_xprt: address too large\n");
1915 		return ERR_PTR(-EBADF);
1916 	}
1917 
1918 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1919 	if (new == NULL) {
1920 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
1921 				"rpc_xprt\n");
1922 		return ERR_PTR(-ENOMEM);
1923 	}
1924 	xprt = &new->xprt;
1925 
1926 	xprt->max_reqs = slot_table_size;
1927 	xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
1928 	if (xprt->slot == NULL) {
1929 		kfree(xprt);
1930 		dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
1931 				"table\n");
1932 		return ERR_PTR(-ENOMEM);
1933 	}
1934 
1935 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
1936 	xprt->addrlen = args->addrlen;
1937 	if (args->srcaddr)
1938 		memcpy(&new->addr, args->srcaddr, args->addrlen);
1939 
1940 	return xprt;
1941 }
1942 
1943 static const struct rpc_timeout xs_udp_default_timeout = {
1944 	.to_initval = 5 * HZ,
1945 	.to_maxval = 30 * HZ,
1946 	.to_increment = 5 * HZ,
1947 	.to_retries = 5,
1948 };
1949 
1950 /**
1951  * xs_setup_udp - Set up transport to use a UDP socket
1952  * @args: rpc transport creation arguments
1953  *
1954  */
1955 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
1956 {
1957 	struct sockaddr *addr = args->dstaddr;
1958 	struct rpc_xprt *xprt;
1959 	struct sock_xprt *transport;
1960 
1961 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
1962 	if (IS_ERR(xprt))
1963 		return xprt;
1964 	transport = container_of(xprt, struct sock_xprt, xprt);
1965 
1966 	xprt->prot = IPPROTO_UDP;
1967 	xprt->tsh_size = 0;
1968 	/* XXX: header size can vary due to auth type, IPv6, etc. */
1969 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1970 
1971 	xprt->bind_timeout = XS_BIND_TO;
1972 	xprt->connect_timeout = XS_UDP_CONN_TO;
1973 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
1974 	xprt->idle_timeout = XS_IDLE_DISC_TO;
1975 
1976 	xprt->ops = &xs_udp_ops;
1977 
1978 	xprt->timeout = &xs_udp_default_timeout;
1979 
1980 	switch (addr->sa_family) {
1981 	case AF_INET:
1982 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
1983 			xprt_set_bound(xprt);
1984 
1985 		INIT_DELAYED_WORK(&transport->connect_worker,
1986 					xs_udp_connect_worker4);
1987 		xs_format_ipv4_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
1988 		break;
1989 	case AF_INET6:
1990 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
1991 			xprt_set_bound(xprt);
1992 
1993 		INIT_DELAYED_WORK(&transport->connect_worker,
1994 					xs_udp_connect_worker6);
1995 		xs_format_ipv6_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
1996 		break;
1997 	default:
1998 		kfree(xprt);
1999 		return ERR_PTR(-EAFNOSUPPORT);
2000 	}
2001 
2002 	dprintk("RPC:       set up transport to address %s\n",
2003 			xprt->address_strings[RPC_DISPLAY_ALL]);
2004 
2005 	if (try_module_get(THIS_MODULE))
2006 		return xprt;
2007 
2008 	kfree(xprt->slot);
2009 	kfree(xprt);
2010 	return ERR_PTR(-EINVAL);
2011 }
2012 
2013 static const struct rpc_timeout xs_tcp_default_timeout = {
2014 	.to_initval = 60 * HZ,
2015 	.to_maxval = 60 * HZ,
2016 	.to_retries = 2,
2017 };
2018 
2019 /**
2020  * xs_setup_tcp - Set up transport to use a TCP socket
2021  * @args: rpc transport creation arguments
2022  *
2023  */
2024 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2025 {
2026 	struct sockaddr *addr = args->dstaddr;
2027 	struct rpc_xprt *xprt;
2028 	struct sock_xprt *transport;
2029 
2030 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2031 	if (IS_ERR(xprt))
2032 		return xprt;
2033 	transport = container_of(xprt, struct sock_xprt, xprt);
2034 
2035 	xprt->prot = IPPROTO_TCP;
2036 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2037 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2038 
2039 	xprt->bind_timeout = XS_BIND_TO;
2040 	xprt->connect_timeout = XS_TCP_CONN_TO;
2041 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2042 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2043 
2044 	xprt->ops = &xs_tcp_ops;
2045 	xprt->timeout = &xs_tcp_default_timeout;
2046 
2047 	switch (addr->sa_family) {
2048 	case AF_INET:
2049 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2050 			xprt_set_bound(xprt);
2051 
2052 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker4);
2053 		xs_format_ipv4_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2054 		break;
2055 	case AF_INET6:
2056 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2057 			xprt_set_bound(xprt);
2058 
2059 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker6);
2060 		xs_format_ipv6_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2061 		break;
2062 	default:
2063 		kfree(xprt);
2064 		return ERR_PTR(-EAFNOSUPPORT);
2065 	}
2066 
2067 	dprintk("RPC:       set up transport to address %s\n",
2068 			xprt->address_strings[RPC_DISPLAY_ALL]);
2069 
2070 	if (try_module_get(THIS_MODULE))
2071 		return xprt;
2072 
2073 	kfree(xprt->slot);
2074 	kfree(xprt);
2075 	return ERR_PTR(-EINVAL);
2076 }
2077 
2078 static struct xprt_class	xs_udp_transport = {
2079 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2080 	.name		= "udp",
2081 	.owner		= THIS_MODULE,
2082 	.ident		= IPPROTO_UDP,
2083 	.setup		= xs_setup_udp,
2084 };
2085 
2086 static struct xprt_class	xs_tcp_transport = {
2087 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2088 	.name		= "tcp",
2089 	.owner		= THIS_MODULE,
2090 	.ident		= IPPROTO_TCP,
2091 	.setup		= xs_setup_tcp,
2092 };
2093 
2094 /**
2095  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2096  *
2097  */
2098 int init_socket_xprt(void)
2099 {
2100 #ifdef RPC_DEBUG
2101 	if (!sunrpc_table_header)
2102 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2103 #endif
2104 
2105 	xprt_register_transport(&xs_udp_transport);
2106 	xprt_register_transport(&xs_tcp_transport);
2107 
2108 	return 0;
2109 }
2110 
2111 /**
2112  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2113  *
2114  */
2115 void cleanup_socket_xprt(void)
2116 {
2117 #ifdef RPC_DEBUG
2118 	if (sunrpc_table_header) {
2119 		unregister_sysctl_table(sunrpc_table_header);
2120 		sunrpc_table_header = NULL;
2121 	}
2122 #endif
2123 
2124 	xprt_unregister_transport(&xs_udp_transport);
2125 	xprt_unregister_transport(&xs_tcp_transport);
2126 }
2127