xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 2a9e1cfa23fb62da37739af81127dab5af095d99)
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, NIPQUAD_FMT,
288 				NIPQUAD(addr->sin_addr.s_addr));
289 	}
290 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
291 
292 	buf = kzalloc(8, GFP_KERNEL);
293 	if (buf) {
294 		snprintf(buf, 8, "%u",
295 				ntohs(addr->sin_port));
296 	}
297 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
298 
299 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
300 
301 	buf = kzalloc(48, GFP_KERNEL);
302 	if (buf) {
303 		snprintf(buf, 48, "addr="NIPQUAD_FMT" port=%u proto=%s",
304 			NIPQUAD(addr->sin_addr.s_addr),
305 			ntohs(addr->sin_port),
306 			protocol);
307 	}
308 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
309 
310 	buf = kzalloc(10, GFP_KERNEL);
311 	if (buf) {
312 		snprintf(buf, 10, "%02x%02x%02x%02x",
313 				NIPQUAD(addr->sin_addr.s_addr));
314 	}
315 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
316 
317 	buf = kzalloc(8, GFP_KERNEL);
318 	if (buf) {
319 		snprintf(buf, 8, "%4hx",
320 				ntohs(addr->sin_port));
321 	}
322 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
323 
324 	buf = kzalloc(30, GFP_KERNEL);
325 	if (buf) {
326 		snprintf(buf, 30, NIPQUAD_FMT".%u.%u",
327 				NIPQUAD(addr->sin_addr.s_addr),
328 				ntohs(addr->sin_port) >> 8,
329 				ntohs(addr->sin_port) & 0xff);
330 	}
331 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
332 
333 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
334 }
335 
336 static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt,
337 					  const char *protocol,
338 					  const char *netid)
339 {
340 	struct sockaddr_in6 *addr = xs_addr_in6(xprt);
341 	char *buf;
342 
343 	buf = kzalloc(40, GFP_KERNEL);
344 	if (buf) {
345 		snprintf(buf, 40, NIP6_FMT,
346 				NIP6(addr->sin6_addr));
347 	}
348 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
349 
350 	buf = kzalloc(8, GFP_KERNEL);
351 	if (buf) {
352 		snprintf(buf, 8, "%u",
353 				ntohs(addr->sin6_port));
354 	}
355 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
356 
357 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
358 
359 	buf = kzalloc(64, GFP_KERNEL);
360 	if (buf) {
361 		snprintf(buf, 64, "addr="NIP6_FMT" port=%u proto=%s",
362 				NIP6(addr->sin6_addr),
363 				ntohs(addr->sin6_port),
364 				protocol);
365 	}
366 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
367 
368 	buf = kzalloc(36, GFP_KERNEL);
369 	if (buf) {
370 		snprintf(buf, 36, NIP6_SEQFMT,
371 				NIP6(addr->sin6_addr));
372 	}
373 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
374 
375 	buf = kzalloc(8, GFP_KERNEL);
376 	if (buf) {
377 		snprintf(buf, 8, "%4hx",
378 				ntohs(addr->sin6_port));
379 	}
380 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
381 
382 	buf = kzalloc(50, GFP_KERNEL);
383 	if (buf) {
384 		snprintf(buf, 50, NIP6_FMT".%u.%u",
385 				NIP6(addr->sin6_addr),
386 				ntohs(addr->sin6_port) >> 8,
387 				ntohs(addr->sin6_port) & 0xff);
388 	}
389 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
390 
391 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
392 }
393 
394 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
395 {
396 	unsigned int i;
397 
398 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
399 		switch (i) {
400 		case RPC_DISPLAY_PROTO:
401 		case RPC_DISPLAY_NETID:
402 			continue;
403 		default:
404 			kfree(xprt->address_strings[i]);
405 		}
406 }
407 
408 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
409 
410 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
411 {
412 	struct msghdr msg = {
413 		.msg_name	= addr,
414 		.msg_namelen	= addrlen,
415 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
416 	};
417 	struct kvec iov = {
418 		.iov_base	= vec->iov_base + base,
419 		.iov_len	= vec->iov_len - base,
420 	};
421 
422 	if (iov.iov_len != 0)
423 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
424 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
425 }
426 
427 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
428 {
429 	struct page **ppage;
430 	unsigned int remainder;
431 	int err, sent = 0;
432 
433 	remainder = xdr->page_len - base;
434 	base += xdr->page_base;
435 	ppage = xdr->pages + (base >> PAGE_SHIFT);
436 	base &= ~PAGE_MASK;
437 	for(;;) {
438 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
439 		int flags = XS_SENDMSG_FLAGS;
440 
441 		remainder -= len;
442 		if (remainder != 0 || more)
443 			flags |= MSG_MORE;
444 		err = sock->ops->sendpage(sock, *ppage, base, len, flags);
445 		if (remainder == 0 || err != len)
446 			break;
447 		sent += err;
448 		ppage++;
449 		base = 0;
450 	}
451 	if (sent == 0)
452 		return err;
453 	if (err > 0)
454 		sent += err;
455 	return sent;
456 }
457 
458 /**
459  * xs_sendpages - write pages directly to a socket
460  * @sock: socket to send on
461  * @addr: UDP only -- address of destination
462  * @addrlen: UDP only -- length of destination address
463  * @xdr: buffer containing this request
464  * @base: starting position in the buffer
465  *
466  */
467 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
468 {
469 	unsigned int remainder = xdr->len - base;
470 	int err, sent = 0;
471 
472 	if (unlikely(!sock))
473 		return -ENOTCONN;
474 
475 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
476 	if (base != 0) {
477 		addr = NULL;
478 		addrlen = 0;
479 	}
480 
481 	if (base < xdr->head[0].iov_len || addr != NULL) {
482 		unsigned int len = xdr->head[0].iov_len - base;
483 		remainder -= len;
484 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
485 		if (remainder == 0 || err != len)
486 			goto out;
487 		sent += err;
488 		base = 0;
489 	} else
490 		base -= xdr->head[0].iov_len;
491 
492 	if (base < xdr->page_len) {
493 		unsigned int len = xdr->page_len - base;
494 		remainder -= len;
495 		err = xs_send_pagedata(sock, xdr, base, remainder != 0);
496 		if (remainder == 0 || err != len)
497 			goto out;
498 		sent += err;
499 		base = 0;
500 	} else
501 		base -= xdr->page_len;
502 
503 	if (base >= xdr->tail[0].iov_len)
504 		return sent;
505 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
506 out:
507 	if (sent == 0)
508 		return err;
509 	if (err > 0)
510 		sent += err;
511 	return sent;
512 }
513 
514 static void xs_nospace_callback(struct rpc_task *task)
515 {
516 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
517 
518 	transport->inet->sk_write_pending--;
519 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
520 }
521 
522 /**
523  * xs_nospace - place task on wait queue if transmit was incomplete
524  * @task: task to put to sleep
525  *
526  */
527 static void xs_nospace(struct rpc_task *task)
528 {
529 	struct rpc_rqst *req = task->tk_rqstp;
530 	struct rpc_xprt *xprt = req->rq_xprt;
531 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
532 
533 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
534 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
535 			req->rq_slen);
536 
537 	/* Protect against races with write_space */
538 	spin_lock_bh(&xprt->transport_lock);
539 
540 	/* Don't race with disconnect */
541 	if (xprt_connected(xprt)) {
542 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
543 			/*
544 			 * Notify TCP that we're limited by the application
545 			 * window size
546 			 */
547 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
548 			transport->inet->sk_write_pending++;
549 			/* ...and wait for more buffer space */
550 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
551 		}
552 	} else {
553 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
554 		task->tk_status = -ENOTCONN;
555 	}
556 
557 	spin_unlock_bh(&xprt->transport_lock);
558 }
559 
560 /**
561  * xs_udp_send_request - write an RPC request to a UDP socket
562  * @task: address of RPC task that manages the state of an RPC request
563  *
564  * Return values:
565  *        0:	The request has been sent
566  *   EAGAIN:	The socket was blocked, please call again later to
567  *		complete the request
568  * ENOTCONN:	Caller needs to invoke connect logic then call again
569  *    other:	Some other error occured, the request was not sent
570  */
571 static int xs_udp_send_request(struct rpc_task *task)
572 {
573 	struct rpc_rqst *req = task->tk_rqstp;
574 	struct rpc_xprt *xprt = req->rq_xprt;
575 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
576 	struct xdr_buf *xdr = &req->rq_snd_buf;
577 	int status;
578 
579 	xs_pktdump("packet data:",
580 				req->rq_svec->iov_base,
581 				req->rq_svec->iov_len);
582 
583 	status = xs_sendpages(transport->sock,
584 			      xs_addr(xprt),
585 			      xprt->addrlen, xdr,
586 			      req->rq_bytes_sent);
587 
588 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
589 			xdr->len - req->rq_bytes_sent, status);
590 
591 	if (status >= 0) {
592 		task->tk_bytes_sent += status;
593 		if (status >= req->rq_slen)
594 			return 0;
595 		/* Still some bytes left; set up for a retry later. */
596 		status = -EAGAIN;
597 	}
598 
599 	switch (status) {
600 	case -EAGAIN:
601 		xs_nospace(task);
602 		break;
603 	case -ENETUNREACH:
604 	case -EPIPE:
605 	case -ECONNREFUSED:
606 		/* When the server has died, an ICMP port unreachable message
607 		 * prompts ECONNREFUSED. */
608 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
609 		break;
610 	default:
611 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
612 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
613 			-status);
614 	}
615 
616 	return status;
617 }
618 
619 /**
620  * xs_tcp_shutdown - gracefully shut down a TCP socket
621  * @xprt: transport
622  *
623  * Initiates a graceful shutdown of the TCP socket by calling the
624  * equivalent of shutdown(SHUT_WR);
625  */
626 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
627 {
628 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
629 	struct socket *sock = transport->sock;
630 
631 	if (sock != NULL)
632 		kernel_sock_shutdown(sock, SHUT_WR);
633 }
634 
635 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
636 {
637 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
638 	rpc_fraghdr *base = buf->head[0].iov_base;
639 	*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
640 }
641 
642 /**
643  * xs_tcp_send_request - write an RPC request to a TCP socket
644  * @task: address of RPC task that manages the state of an RPC request
645  *
646  * Return values:
647  *        0:	The request has been sent
648  *   EAGAIN:	The socket was blocked, please call again later to
649  *		complete the request
650  * ENOTCONN:	Caller needs to invoke connect logic then call again
651  *    other:	Some other error occured, the request was not sent
652  *
653  * XXX: In the case of soft timeouts, should we eventually give up
654  *	if sendmsg is not able to make progress?
655  */
656 static int xs_tcp_send_request(struct rpc_task *task)
657 {
658 	struct rpc_rqst *req = task->tk_rqstp;
659 	struct rpc_xprt *xprt = req->rq_xprt;
660 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
661 	struct xdr_buf *xdr = &req->rq_snd_buf;
662 	int status;
663 
664 	xs_encode_tcp_record_marker(&req->rq_snd_buf);
665 
666 	xs_pktdump("packet data:",
667 				req->rq_svec->iov_base,
668 				req->rq_svec->iov_len);
669 
670 	/* Continue transmitting the packet/record. We must be careful
671 	 * to cope with writespace callbacks arriving _after_ we have
672 	 * called sendmsg(). */
673 	while (1) {
674 		status = xs_sendpages(transport->sock,
675 					NULL, 0, xdr, req->rq_bytes_sent);
676 
677 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
678 				xdr->len - req->rq_bytes_sent, status);
679 
680 		if (unlikely(status < 0))
681 			break;
682 
683 		/* If we've sent the entire packet, immediately
684 		 * reset the count of bytes sent. */
685 		req->rq_bytes_sent += status;
686 		task->tk_bytes_sent += status;
687 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
688 			req->rq_bytes_sent = 0;
689 			return 0;
690 		}
691 
692 		if (status != 0)
693 			continue;
694 		status = -EAGAIN;
695 		break;
696 	}
697 
698 	switch (status) {
699 	case -EAGAIN:
700 		xs_nospace(task);
701 		break;
702 	case -ECONNRESET:
703 		xs_tcp_shutdown(xprt);
704 	case -ECONNREFUSED:
705 	case -ENOTCONN:
706 	case -EPIPE:
707 		status = -ENOTCONN;
708 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
709 		break;
710 	default:
711 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
712 			-status);
713 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
714 		xs_tcp_shutdown(xprt);
715 	}
716 
717 	return status;
718 }
719 
720 /**
721  * xs_tcp_release_xprt - clean up after a tcp transmission
722  * @xprt: transport
723  * @task: rpc task
724  *
725  * This cleans up if an error causes us to abort the transmission of a request.
726  * In this case, the socket may need to be reset in order to avoid confusing
727  * the server.
728  */
729 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
730 {
731 	struct rpc_rqst *req;
732 
733 	if (task != xprt->snd_task)
734 		return;
735 	if (task == NULL)
736 		goto out_release;
737 	req = task->tk_rqstp;
738 	if (req->rq_bytes_sent == 0)
739 		goto out_release;
740 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
741 		goto out_release;
742 	set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
743 out_release:
744 	xprt_release_xprt(xprt, task);
745 }
746 
747 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
748 {
749 	transport->old_data_ready = sk->sk_data_ready;
750 	transport->old_state_change = sk->sk_state_change;
751 	transport->old_write_space = sk->sk_write_space;
752 	transport->old_error_report = sk->sk_error_report;
753 }
754 
755 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
756 {
757 	sk->sk_data_ready = transport->old_data_ready;
758 	sk->sk_state_change = transport->old_state_change;
759 	sk->sk_write_space = transport->old_write_space;
760 	sk->sk_error_report = transport->old_error_report;
761 }
762 
763 /**
764  * xs_close - close a socket
765  * @xprt: transport
766  *
767  * This is used when all requests are complete; ie, no DRC state remains
768  * on the server we want to save.
769  */
770 static void xs_close(struct rpc_xprt *xprt)
771 {
772 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
773 	struct socket *sock = transport->sock;
774 	struct sock *sk = transport->inet;
775 
776 	if (!sk)
777 		goto clear_close_wait;
778 
779 	dprintk("RPC:       xs_close xprt %p\n", xprt);
780 
781 	write_lock_bh(&sk->sk_callback_lock);
782 	transport->inet = NULL;
783 	transport->sock = NULL;
784 
785 	sk->sk_user_data = NULL;
786 
787 	xs_restore_old_callbacks(transport, sk);
788 	write_unlock_bh(&sk->sk_callback_lock);
789 
790 	sk->sk_no_check = 0;
791 
792 	sock_release(sock);
793 clear_close_wait:
794 	smp_mb__before_clear_bit();
795 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
796 	clear_bit(XPRT_CLOSING, &xprt->state);
797 	smp_mb__after_clear_bit();
798 	xprt_disconnect_done(xprt);
799 }
800 
801 /**
802  * xs_destroy - prepare to shutdown a transport
803  * @xprt: doomed transport
804  *
805  */
806 static void xs_destroy(struct rpc_xprt *xprt)
807 {
808 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
809 
810 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
811 
812 	cancel_rearming_delayed_work(&transport->connect_worker);
813 
814 	xs_close(xprt);
815 	xs_free_peer_addresses(xprt);
816 	kfree(xprt->slot);
817 	kfree(xprt);
818 	module_put(THIS_MODULE);
819 }
820 
821 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
822 {
823 	return (struct rpc_xprt *) sk->sk_user_data;
824 }
825 
826 /**
827  * xs_udp_data_ready - "data ready" callback for UDP sockets
828  * @sk: socket with data to read
829  * @len: how much data to read
830  *
831  */
832 static void xs_udp_data_ready(struct sock *sk, int len)
833 {
834 	struct rpc_task *task;
835 	struct rpc_xprt *xprt;
836 	struct rpc_rqst *rovr;
837 	struct sk_buff *skb;
838 	int err, repsize, copied;
839 	u32 _xid;
840 	__be32 *xp;
841 
842 	read_lock(&sk->sk_callback_lock);
843 	dprintk("RPC:       xs_udp_data_ready...\n");
844 	if (!(xprt = xprt_from_sock(sk)))
845 		goto out;
846 
847 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
848 		goto out;
849 
850 	if (xprt->shutdown)
851 		goto dropit;
852 
853 	repsize = skb->len - sizeof(struct udphdr);
854 	if (repsize < 4) {
855 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
856 		goto dropit;
857 	}
858 
859 	/* Copy the XID from the skb... */
860 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
861 				sizeof(_xid), &_xid);
862 	if (xp == NULL)
863 		goto dropit;
864 
865 	/* Look up and lock the request corresponding to the given XID */
866 	spin_lock(&xprt->transport_lock);
867 	rovr = xprt_lookup_rqst(xprt, *xp);
868 	if (!rovr)
869 		goto out_unlock;
870 	task = rovr->rq_task;
871 
872 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
873 		copied = repsize;
874 
875 	/* Suck it into the iovec, verify checksum if not done by hw. */
876 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
877 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
878 		goto out_unlock;
879 	}
880 
881 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
882 
883 	/* Something worked... */
884 	dst_confirm(skb->dst);
885 
886 	xprt_adjust_cwnd(task, copied);
887 	xprt_update_rtt(task);
888 	xprt_complete_rqst(task, copied);
889 
890  out_unlock:
891 	spin_unlock(&xprt->transport_lock);
892  dropit:
893 	skb_free_datagram(sk, skb);
894  out:
895 	read_unlock(&sk->sk_callback_lock);
896 }
897 
898 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
899 {
900 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
901 	size_t len, used;
902 	char *p;
903 
904 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
905 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
906 	used = xdr_skb_read_bits(desc, p, len);
907 	transport->tcp_offset += used;
908 	if (used != len)
909 		return;
910 
911 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
912 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
913 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
914 	else
915 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
916 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
917 
918 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
919 	transport->tcp_offset = 0;
920 
921 	/* Sanity check of the record length */
922 	if (unlikely(transport->tcp_reclen < 4)) {
923 		dprintk("RPC:       invalid TCP record fragment length\n");
924 		xprt_force_disconnect(xprt);
925 		return;
926 	}
927 	dprintk("RPC:       reading TCP record fragment of length %d\n",
928 			transport->tcp_reclen);
929 }
930 
931 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
932 {
933 	if (transport->tcp_offset == transport->tcp_reclen) {
934 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
935 		transport->tcp_offset = 0;
936 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
937 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
938 			transport->tcp_flags |= TCP_RCV_COPY_XID;
939 			transport->tcp_copied = 0;
940 		}
941 	}
942 }
943 
944 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
945 {
946 	size_t len, used;
947 	char *p;
948 
949 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
950 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
951 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
952 	used = xdr_skb_read_bits(desc, p, len);
953 	transport->tcp_offset += used;
954 	if (used != len)
955 		return;
956 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
957 	transport->tcp_flags |= TCP_RCV_COPY_DATA;
958 	transport->tcp_copied = 4;
959 	dprintk("RPC:       reading reply for XID %08x\n",
960 			ntohl(transport->tcp_xid));
961 	xs_tcp_check_fraghdr(transport);
962 }
963 
964 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
965 {
966 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
967 	struct rpc_rqst *req;
968 	struct xdr_buf *rcvbuf;
969 	size_t len;
970 	ssize_t r;
971 
972 	/* Find and lock the request corresponding to this xid */
973 	spin_lock(&xprt->transport_lock);
974 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
975 	if (!req) {
976 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
977 		dprintk("RPC:       XID %08x request not found!\n",
978 				ntohl(transport->tcp_xid));
979 		spin_unlock(&xprt->transport_lock);
980 		return;
981 	}
982 
983 	rcvbuf = &req->rq_private_buf;
984 	len = desc->count;
985 	if (len > transport->tcp_reclen - transport->tcp_offset) {
986 		struct xdr_skb_reader my_desc;
987 
988 		len = transport->tcp_reclen - transport->tcp_offset;
989 		memcpy(&my_desc, desc, sizeof(my_desc));
990 		my_desc.count = len;
991 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
992 					  &my_desc, xdr_skb_read_bits);
993 		desc->count -= r;
994 		desc->offset += r;
995 	} else
996 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
997 					  desc, xdr_skb_read_bits);
998 
999 	if (r > 0) {
1000 		transport->tcp_copied += r;
1001 		transport->tcp_offset += r;
1002 	}
1003 	if (r != len) {
1004 		/* Error when copying to the receive buffer,
1005 		 * usually because we weren't able to allocate
1006 		 * additional buffer pages. All we can do now
1007 		 * is turn off TCP_RCV_COPY_DATA, so the request
1008 		 * will not receive any additional updates,
1009 		 * and time out.
1010 		 * Any remaining data from this record will
1011 		 * be discarded.
1012 		 */
1013 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1014 		dprintk("RPC:       XID %08x truncated request\n",
1015 				ntohl(transport->tcp_xid));
1016 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1017 				"tcp_offset = %u, tcp_reclen = %u\n",
1018 				xprt, transport->tcp_copied,
1019 				transport->tcp_offset, transport->tcp_reclen);
1020 		goto out;
1021 	}
1022 
1023 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1024 			ntohl(transport->tcp_xid), r);
1025 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1026 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1027 			transport->tcp_offset, transport->tcp_reclen);
1028 
1029 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1030 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1031 	else if (transport->tcp_offset == transport->tcp_reclen) {
1032 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1033 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1034 	}
1035 
1036 out:
1037 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1038 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1039 	spin_unlock(&xprt->transport_lock);
1040 	xs_tcp_check_fraghdr(transport);
1041 }
1042 
1043 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1044 {
1045 	size_t len;
1046 
1047 	len = transport->tcp_reclen - transport->tcp_offset;
1048 	if (len > desc->count)
1049 		len = desc->count;
1050 	desc->count -= len;
1051 	desc->offset += len;
1052 	transport->tcp_offset += len;
1053 	dprintk("RPC:       discarded %Zu bytes\n", len);
1054 	xs_tcp_check_fraghdr(transport);
1055 }
1056 
1057 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1058 {
1059 	struct rpc_xprt *xprt = rd_desc->arg.data;
1060 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1061 	struct xdr_skb_reader desc = {
1062 		.skb	= skb,
1063 		.offset	= offset,
1064 		.count	= len,
1065 	};
1066 
1067 	dprintk("RPC:       xs_tcp_data_recv started\n");
1068 	do {
1069 		/* Read in a new fragment marker if necessary */
1070 		/* Can we ever really expect to get completely empty fragments? */
1071 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1072 			xs_tcp_read_fraghdr(xprt, &desc);
1073 			continue;
1074 		}
1075 		/* Read in the xid if necessary */
1076 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1077 			xs_tcp_read_xid(transport, &desc);
1078 			continue;
1079 		}
1080 		/* Read in the request data */
1081 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1082 			xs_tcp_read_request(xprt, &desc);
1083 			continue;
1084 		}
1085 		/* Skip over any trailing bytes on short reads */
1086 		xs_tcp_read_discard(transport, &desc);
1087 	} while (desc.count);
1088 	dprintk("RPC:       xs_tcp_data_recv done\n");
1089 	return len - desc.count;
1090 }
1091 
1092 /**
1093  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1094  * @sk: socket with data to read
1095  * @bytes: how much data to read
1096  *
1097  */
1098 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1099 {
1100 	struct rpc_xprt *xprt;
1101 	read_descriptor_t rd_desc;
1102 	int read;
1103 
1104 	dprintk("RPC:       xs_tcp_data_ready...\n");
1105 
1106 	read_lock(&sk->sk_callback_lock);
1107 	if (!(xprt = xprt_from_sock(sk)))
1108 		goto out;
1109 	if (xprt->shutdown)
1110 		goto out;
1111 
1112 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1113 	rd_desc.arg.data = xprt;
1114 	do {
1115 		rd_desc.count = 65536;
1116 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1117 	} while (read > 0);
1118 out:
1119 	read_unlock(&sk->sk_callback_lock);
1120 }
1121 
1122 /**
1123  * xs_tcp_state_change - callback to handle TCP socket state changes
1124  * @sk: socket whose state has changed
1125  *
1126  */
1127 static void xs_tcp_state_change(struct sock *sk)
1128 {
1129 	struct rpc_xprt *xprt;
1130 
1131 	read_lock(&sk->sk_callback_lock);
1132 	if (!(xprt = xprt_from_sock(sk)))
1133 		goto out;
1134 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1135 	dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1136 			sk->sk_state, xprt_connected(xprt),
1137 			sock_flag(sk, SOCK_DEAD),
1138 			sock_flag(sk, SOCK_ZAPPED));
1139 
1140 	switch (sk->sk_state) {
1141 	case TCP_ESTABLISHED:
1142 		spin_lock_bh(&xprt->transport_lock);
1143 		if (!xprt_test_and_set_connected(xprt)) {
1144 			struct sock_xprt *transport = container_of(xprt,
1145 					struct sock_xprt, xprt);
1146 
1147 			/* Reset TCP record info */
1148 			transport->tcp_offset = 0;
1149 			transport->tcp_reclen = 0;
1150 			transport->tcp_copied = 0;
1151 			transport->tcp_flags =
1152 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1153 
1154 			xprt_wake_pending_tasks(xprt, 0);
1155 		}
1156 		spin_unlock_bh(&xprt->transport_lock);
1157 		break;
1158 	case TCP_FIN_WAIT1:
1159 		/* The client initiated a shutdown of the socket */
1160 		xprt->connect_cookie++;
1161 		xprt->reestablish_timeout = 0;
1162 		set_bit(XPRT_CLOSING, &xprt->state);
1163 		smp_mb__before_clear_bit();
1164 		clear_bit(XPRT_CONNECTED, &xprt->state);
1165 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1166 		smp_mb__after_clear_bit();
1167 		break;
1168 	case TCP_CLOSE_WAIT:
1169 		/* The server initiated a shutdown of the socket */
1170 		set_bit(XPRT_CLOSING, &xprt->state);
1171 		xprt_force_disconnect(xprt);
1172 	case TCP_SYN_SENT:
1173 		xprt->connect_cookie++;
1174 	case TCP_CLOSING:
1175 		/*
1176 		 * If the server closed down the connection, make sure that
1177 		 * we back off before reconnecting
1178 		 */
1179 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1180 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1181 		break;
1182 	case TCP_LAST_ACK:
1183 		smp_mb__before_clear_bit();
1184 		clear_bit(XPRT_CONNECTED, &xprt->state);
1185 		smp_mb__after_clear_bit();
1186 		break;
1187 	case TCP_CLOSE:
1188 		smp_mb__before_clear_bit();
1189 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1190 		clear_bit(XPRT_CLOSING, &xprt->state);
1191 		smp_mb__after_clear_bit();
1192 		/* Mark transport as closed and wake up all pending tasks */
1193 		xprt_disconnect_done(xprt);
1194 	}
1195  out:
1196 	read_unlock(&sk->sk_callback_lock);
1197 }
1198 
1199 /**
1200  * xs_tcp_error_report - callback mainly for catching RST events
1201  * @sk: socket
1202  */
1203 static void xs_tcp_error_report(struct sock *sk)
1204 {
1205 	struct rpc_xprt *xprt;
1206 
1207 	read_lock(&sk->sk_callback_lock);
1208 	if (sk->sk_err != ECONNRESET || sk->sk_state != TCP_ESTABLISHED)
1209 		goto out;
1210 	if (!(xprt = xprt_from_sock(sk)))
1211 		goto out;
1212 	dprintk("RPC:       %s client %p...\n"
1213 			"RPC:       error %d\n",
1214 			__func__, xprt, sk->sk_err);
1215 
1216 	xprt_force_disconnect(xprt);
1217 out:
1218 	read_unlock(&sk->sk_callback_lock);
1219 }
1220 
1221 /**
1222  * xs_udp_write_space - callback invoked when socket buffer space
1223  *                             becomes available
1224  * @sk: socket whose state has changed
1225  *
1226  * Called when more output buffer space is available for this socket.
1227  * We try not to wake our writers until they can make "significant"
1228  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1229  * with a bunch of small requests.
1230  */
1231 static void xs_udp_write_space(struct sock *sk)
1232 {
1233 	read_lock(&sk->sk_callback_lock);
1234 
1235 	/* from net/core/sock.c:sock_def_write_space */
1236 	if (sock_writeable(sk)) {
1237 		struct socket *sock;
1238 		struct rpc_xprt *xprt;
1239 
1240 		if (unlikely(!(sock = sk->sk_socket)))
1241 			goto out;
1242 		clear_bit(SOCK_NOSPACE, &sock->flags);
1243 
1244 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1245 			goto out;
1246 		if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1247 			goto out;
1248 
1249 		xprt_write_space(xprt);
1250 	}
1251 
1252  out:
1253 	read_unlock(&sk->sk_callback_lock);
1254 }
1255 
1256 /**
1257  * xs_tcp_write_space - callback invoked when socket buffer space
1258  *                             becomes available
1259  * @sk: socket whose state has changed
1260  *
1261  * Called when more output buffer space is available for this socket.
1262  * We try not to wake our writers until they can make "significant"
1263  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1264  * with a bunch of small requests.
1265  */
1266 static void xs_tcp_write_space(struct sock *sk)
1267 {
1268 	read_lock(&sk->sk_callback_lock);
1269 
1270 	/* from net/core/stream.c:sk_stream_write_space */
1271 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
1272 		struct socket *sock;
1273 		struct rpc_xprt *xprt;
1274 
1275 		if (unlikely(!(sock = sk->sk_socket)))
1276 			goto out;
1277 		clear_bit(SOCK_NOSPACE, &sock->flags);
1278 
1279 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1280 			goto out;
1281 		if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1282 			goto out;
1283 
1284 		xprt_write_space(xprt);
1285 	}
1286 
1287  out:
1288 	read_unlock(&sk->sk_callback_lock);
1289 }
1290 
1291 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1292 {
1293 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1294 	struct sock *sk = transport->inet;
1295 
1296 	if (transport->rcvsize) {
1297 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1298 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1299 	}
1300 	if (transport->sndsize) {
1301 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1302 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1303 		sk->sk_write_space(sk);
1304 	}
1305 }
1306 
1307 /**
1308  * xs_udp_set_buffer_size - set send and receive limits
1309  * @xprt: generic transport
1310  * @sndsize: requested size of send buffer, in bytes
1311  * @rcvsize: requested size of receive buffer, in bytes
1312  *
1313  * Set socket send and receive buffer size limits.
1314  */
1315 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1316 {
1317 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1318 
1319 	transport->sndsize = 0;
1320 	if (sndsize)
1321 		transport->sndsize = sndsize + 1024;
1322 	transport->rcvsize = 0;
1323 	if (rcvsize)
1324 		transport->rcvsize = rcvsize + 1024;
1325 
1326 	xs_udp_do_set_buffer_size(xprt);
1327 }
1328 
1329 /**
1330  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1331  * @task: task that timed out
1332  *
1333  * Adjust the congestion window after a retransmit timeout has occurred.
1334  */
1335 static void xs_udp_timer(struct rpc_task *task)
1336 {
1337 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1338 }
1339 
1340 static unsigned short xs_get_random_port(void)
1341 {
1342 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1343 	unsigned short rand = (unsigned short) net_random() % range;
1344 	return rand + xprt_min_resvport;
1345 }
1346 
1347 /**
1348  * xs_set_port - reset the port number in the remote endpoint address
1349  * @xprt: generic transport
1350  * @port: new port number
1351  *
1352  */
1353 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1354 {
1355 	struct sockaddr *addr = xs_addr(xprt);
1356 
1357 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1358 
1359 	switch (addr->sa_family) {
1360 	case AF_INET:
1361 		((struct sockaddr_in *)addr)->sin_port = htons(port);
1362 		break;
1363 	case AF_INET6:
1364 		((struct sockaddr_in6 *)addr)->sin6_port = htons(port);
1365 		break;
1366 	default:
1367 		BUG();
1368 	}
1369 }
1370 
1371 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1372 {
1373 	unsigned short port = transport->port;
1374 
1375 	if (port == 0 && transport->xprt.resvport)
1376 		port = xs_get_random_port();
1377 	return port;
1378 }
1379 
1380 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1381 {
1382 	if (transport->port != 0)
1383 		transport->port = 0;
1384 	if (!transport->xprt.resvport)
1385 		return 0;
1386 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1387 		return xprt_max_resvport;
1388 	return --port;
1389 }
1390 
1391 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1392 {
1393 	struct sockaddr_in myaddr = {
1394 		.sin_family = AF_INET,
1395 	};
1396 	struct sockaddr_in *sa;
1397 	int err, nloop = 0;
1398 	unsigned short port = xs_get_srcport(transport, sock);
1399 	unsigned short last;
1400 
1401 	sa = (struct sockaddr_in *)&transport->addr;
1402 	myaddr.sin_addr = sa->sin_addr;
1403 	do {
1404 		myaddr.sin_port = htons(port);
1405 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1406 						sizeof(myaddr));
1407 		if (port == 0)
1408 			break;
1409 		if (err == 0) {
1410 			transport->port = port;
1411 			break;
1412 		}
1413 		last = port;
1414 		port = xs_next_srcport(transport, sock, port);
1415 		if (port > last)
1416 			nloop++;
1417 	} while (err == -EADDRINUSE && nloop != 2);
1418 	dprintk("RPC:       %s "NIPQUAD_FMT":%u: %s (%d)\n",
1419 			__func__, NIPQUAD(myaddr.sin_addr),
1420 			port, err ? "failed" : "ok", err);
1421 	return err;
1422 }
1423 
1424 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1425 {
1426 	struct sockaddr_in6 myaddr = {
1427 		.sin6_family = AF_INET6,
1428 	};
1429 	struct sockaddr_in6 *sa;
1430 	int err, nloop = 0;
1431 	unsigned short port = xs_get_srcport(transport, sock);
1432 	unsigned short last;
1433 
1434 	sa = (struct sockaddr_in6 *)&transport->addr;
1435 	myaddr.sin6_addr = sa->sin6_addr;
1436 	do {
1437 		myaddr.sin6_port = htons(port);
1438 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1439 						sizeof(myaddr));
1440 		if (port == 0)
1441 			break;
1442 		if (err == 0) {
1443 			transport->port = port;
1444 			break;
1445 		}
1446 		last = port;
1447 		port = xs_next_srcport(transport, sock, port);
1448 		if (port > last)
1449 			nloop++;
1450 	} while (err == -EADDRINUSE && nloop != 2);
1451 	dprintk("RPC:       xs_bind6 "NIP6_FMT":%u: %s (%d)\n",
1452 		NIP6(myaddr.sin6_addr), port, err ? "failed" : "ok", err);
1453 	return err;
1454 }
1455 
1456 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1457 static struct lock_class_key xs_key[2];
1458 static struct lock_class_key xs_slock_key[2];
1459 
1460 static inline void xs_reclassify_socket4(struct socket *sock)
1461 {
1462 	struct sock *sk = sock->sk;
1463 
1464 	BUG_ON(sock_owned_by_user(sk));
1465 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1466 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1467 }
1468 
1469 static inline void xs_reclassify_socket6(struct socket *sock)
1470 {
1471 	struct sock *sk = sock->sk;
1472 
1473 	BUG_ON(sock_owned_by_user(sk));
1474 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1475 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1476 }
1477 #else
1478 static inline void xs_reclassify_socket4(struct socket *sock)
1479 {
1480 }
1481 
1482 static inline void xs_reclassify_socket6(struct socket *sock)
1483 {
1484 }
1485 #endif
1486 
1487 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1488 {
1489 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1490 
1491 	if (!transport->inet) {
1492 		struct sock *sk = sock->sk;
1493 
1494 		write_lock_bh(&sk->sk_callback_lock);
1495 
1496 		xs_save_old_callbacks(transport, sk);
1497 
1498 		sk->sk_user_data = xprt;
1499 		sk->sk_data_ready = xs_udp_data_ready;
1500 		sk->sk_write_space = xs_udp_write_space;
1501 		sk->sk_no_check = UDP_CSUM_NORCV;
1502 		sk->sk_allocation = GFP_ATOMIC;
1503 
1504 		xprt_set_connected(xprt);
1505 
1506 		/* Reset to new socket */
1507 		transport->sock = sock;
1508 		transport->inet = sk;
1509 
1510 		write_unlock_bh(&sk->sk_callback_lock);
1511 	}
1512 	xs_udp_do_set_buffer_size(xprt);
1513 }
1514 
1515 /**
1516  * xs_udp_connect_worker4 - set up a UDP socket
1517  * @work: RPC transport to connect
1518  *
1519  * Invoked by a work queue tasklet.
1520  */
1521 static void xs_udp_connect_worker4(struct work_struct *work)
1522 {
1523 	struct sock_xprt *transport =
1524 		container_of(work, struct sock_xprt, connect_worker.work);
1525 	struct rpc_xprt *xprt = &transport->xprt;
1526 	struct socket *sock = transport->sock;
1527 	int err, status = -EIO;
1528 
1529 	if (xprt->shutdown || !xprt_bound(xprt))
1530 		goto out;
1531 
1532 	/* Start by resetting any existing state */
1533 	xs_close(xprt);
1534 
1535 	if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1536 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1537 		goto out;
1538 	}
1539 	xs_reclassify_socket4(sock);
1540 
1541 	if (xs_bind4(transport, sock)) {
1542 		sock_release(sock);
1543 		goto out;
1544 	}
1545 
1546 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1547 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1548 
1549 	xs_udp_finish_connecting(xprt, sock);
1550 	status = 0;
1551 out:
1552 	xprt_wake_pending_tasks(xprt, status);
1553 	xprt_clear_connecting(xprt);
1554 }
1555 
1556 /**
1557  * xs_udp_connect_worker6 - set up a UDP socket
1558  * @work: RPC transport to connect
1559  *
1560  * Invoked by a work queue tasklet.
1561  */
1562 static void xs_udp_connect_worker6(struct work_struct *work)
1563 {
1564 	struct sock_xprt *transport =
1565 		container_of(work, struct sock_xprt, connect_worker.work);
1566 	struct rpc_xprt *xprt = &transport->xprt;
1567 	struct socket *sock = transport->sock;
1568 	int err, status = -EIO;
1569 
1570 	if (xprt->shutdown || !xprt_bound(xprt))
1571 		goto out;
1572 
1573 	/* Start by resetting any existing state */
1574 	xs_close(xprt);
1575 
1576 	if ((err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1577 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1578 		goto out;
1579 	}
1580 	xs_reclassify_socket6(sock);
1581 
1582 	if (xs_bind6(transport, sock) < 0) {
1583 		sock_release(sock);
1584 		goto out;
1585 	}
1586 
1587 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1588 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1589 
1590 	xs_udp_finish_connecting(xprt, sock);
1591 	status = 0;
1592 out:
1593 	xprt_wake_pending_tasks(xprt, status);
1594 	xprt_clear_connecting(xprt);
1595 }
1596 
1597 /*
1598  * We need to preserve the port number so the reply cache on the server can
1599  * find our cached RPC replies when we get around to reconnecting.
1600  */
1601 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1602 {
1603 	int result;
1604 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1605 	struct sockaddr any;
1606 
1607 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1608 
1609 	/*
1610 	 * Disconnect the transport socket by doing a connect operation
1611 	 * with AF_UNSPEC.  This should return immediately...
1612 	 */
1613 	memset(&any, 0, sizeof(any));
1614 	any.sa_family = AF_UNSPEC;
1615 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1616 	if (result)
1617 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1618 				result);
1619 }
1620 
1621 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1622 {
1623 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1624 
1625 	if (!transport->inet) {
1626 		struct sock *sk = sock->sk;
1627 
1628 		write_lock_bh(&sk->sk_callback_lock);
1629 
1630 		xs_save_old_callbacks(transport, sk);
1631 
1632 		sk->sk_user_data = xprt;
1633 		sk->sk_data_ready = xs_tcp_data_ready;
1634 		sk->sk_state_change = xs_tcp_state_change;
1635 		sk->sk_write_space = xs_tcp_write_space;
1636 		sk->sk_error_report = xs_tcp_error_report;
1637 		sk->sk_allocation = GFP_ATOMIC;
1638 
1639 		/* socket options */
1640 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1641 		sock_reset_flag(sk, SOCK_LINGER);
1642 		tcp_sk(sk)->linger2 = 0;
1643 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1644 
1645 		xprt_clear_connected(xprt);
1646 
1647 		/* Reset to new socket */
1648 		transport->sock = sock;
1649 		transport->inet = sk;
1650 
1651 		write_unlock_bh(&sk->sk_callback_lock);
1652 	}
1653 
1654 	/* Tell the socket layer to start connecting... */
1655 	xprt->stat.connect_count++;
1656 	xprt->stat.connect_start = jiffies;
1657 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1658 }
1659 
1660 /**
1661  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1662  * @work: RPC transport to connect
1663  *
1664  * Invoked by a work queue tasklet.
1665  */
1666 static void xs_tcp_connect_worker4(struct work_struct *work)
1667 {
1668 	struct sock_xprt *transport =
1669 		container_of(work, struct sock_xprt, connect_worker.work);
1670 	struct rpc_xprt *xprt = &transport->xprt;
1671 	struct socket *sock = transport->sock;
1672 	int err, status = -EIO;
1673 
1674 	if (xprt->shutdown || !xprt_bound(xprt))
1675 		goto out;
1676 
1677 	if (!sock) {
1678 		/* start from scratch */
1679 		if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1680 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1681 			goto out;
1682 		}
1683 		xs_reclassify_socket4(sock);
1684 
1685 		if (xs_bind4(transport, sock) < 0) {
1686 			sock_release(sock);
1687 			goto out;
1688 		}
1689 	} else
1690 		/* "close" the socket, preserving the local port */
1691 		xs_tcp_reuse_connection(xprt);
1692 
1693 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1694 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1695 
1696 	status = xs_tcp_finish_connecting(xprt, sock);
1697 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1698 			xprt, -status, xprt_connected(xprt),
1699 			sock->sk->sk_state);
1700 	if (status < 0) {
1701 		switch (status) {
1702 			case -EINPROGRESS:
1703 			case -EALREADY:
1704 				goto out_clear;
1705 			case -ECONNREFUSED:
1706 			case -ECONNRESET:
1707 				/* retry with existing socket, after a delay */
1708 				break;
1709 			default:
1710 				/* get rid of existing socket, and retry */
1711 				xs_tcp_shutdown(xprt);
1712 		}
1713 	}
1714 out:
1715 	xprt_wake_pending_tasks(xprt, status);
1716 out_clear:
1717 	xprt_clear_connecting(xprt);
1718 }
1719 
1720 /**
1721  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1722  * @work: RPC transport to connect
1723  *
1724  * Invoked by a work queue tasklet.
1725  */
1726 static void xs_tcp_connect_worker6(struct work_struct *work)
1727 {
1728 	struct sock_xprt *transport =
1729 		container_of(work, struct sock_xprt, connect_worker.work);
1730 	struct rpc_xprt *xprt = &transport->xprt;
1731 	struct socket *sock = transport->sock;
1732 	int err, status = -EIO;
1733 
1734 	if (xprt->shutdown || !xprt_bound(xprt))
1735 		goto out;
1736 
1737 	if (!sock) {
1738 		/* start from scratch */
1739 		if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1740 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1741 			goto out;
1742 		}
1743 		xs_reclassify_socket6(sock);
1744 
1745 		if (xs_bind6(transport, sock) < 0) {
1746 			sock_release(sock);
1747 			goto out;
1748 		}
1749 	} else
1750 		/* "close" the socket, preserving the local port */
1751 		xs_tcp_reuse_connection(xprt);
1752 
1753 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1754 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1755 
1756 	status = xs_tcp_finish_connecting(xprt, sock);
1757 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1758 			xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1759 	if (status < 0) {
1760 		switch (status) {
1761 			case -EINPROGRESS:
1762 			case -EALREADY:
1763 				goto out_clear;
1764 			case -ECONNREFUSED:
1765 			case -ECONNRESET:
1766 				/* retry with existing socket, after a delay */
1767 				break;
1768 			default:
1769 				/* get rid of existing socket, and retry */
1770 				xs_tcp_shutdown(xprt);
1771 		}
1772 	}
1773 out:
1774 	xprt_wake_pending_tasks(xprt, status);
1775 out_clear:
1776 	xprt_clear_connecting(xprt);
1777 }
1778 
1779 /**
1780  * xs_connect - connect a socket to a remote endpoint
1781  * @task: address of RPC task that manages state of connect request
1782  *
1783  * TCP: If the remote end dropped the connection, delay reconnecting.
1784  *
1785  * UDP socket connects are synchronous, but we use a work queue anyway
1786  * to guarantee that even unprivileged user processes can set up a
1787  * socket on a privileged port.
1788  *
1789  * If a UDP socket connect fails, the delay behavior here prevents
1790  * retry floods (hard mounts).
1791  */
1792 static void xs_connect(struct rpc_task *task)
1793 {
1794 	struct rpc_xprt *xprt = task->tk_xprt;
1795 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1796 
1797 	if (xprt_test_and_set_connecting(xprt))
1798 		return;
1799 
1800 	if (transport->sock != NULL) {
1801 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
1802 				"seconds\n",
1803 				xprt, xprt->reestablish_timeout / HZ);
1804 		queue_delayed_work(rpciod_workqueue,
1805 				   &transport->connect_worker,
1806 				   xprt->reestablish_timeout);
1807 		xprt->reestablish_timeout <<= 1;
1808 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1809 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1810 	} else {
1811 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
1812 		queue_delayed_work(rpciod_workqueue,
1813 				   &transport->connect_worker, 0);
1814 	}
1815 }
1816 
1817 static void xs_tcp_connect(struct rpc_task *task)
1818 {
1819 	struct rpc_xprt *xprt = task->tk_xprt;
1820 
1821 	/* Initiate graceful shutdown of the socket if not already done */
1822 	if (test_bit(XPRT_CONNECTED, &xprt->state))
1823 		xs_tcp_shutdown(xprt);
1824 	/* Exit if we need to wait for socket shutdown to complete */
1825 	if (test_bit(XPRT_CLOSING, &xprt->state))
1826 		return;
1827 	xs_connect(task);
1828 }
1829 
1830 /**
1831  * xs_udp_print_stats - display UDP socket-specifc stats
1832  * @xprt: rpc_xprt struct containing statistics
1833  * @seq: output file
1834  *
1835  */
1836 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1837 {
1838 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1839 
1840 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1841 			transport->port,
1842 			xprt->stat.bind_count,
1843 			xprt->stat.sends,
1844 			xprt->stat.recvs,
1845 			xprt->stat.bad_xids,
1846 			xprt->stat.req_u,
1847 			xprt->stat.bklog_u);
1848 }
1849 
1850 /**
1851  * xs_tcp_print_stats - display TCP socket-specifc stats
1852  * @xprt: rpc_xprt struct containing statistics
1853  * @seq: output file
1854  *
1855  */
1856 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1857 {
1858 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1859 	long idle_time = 0;
1860 
1861 	if (xprt_connected(xprt))
1862 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
1863 
1864 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1865 			transport->port,
1866 			xprt->stat.bind_count,
1867 			xprt->stat.connect_count,
1868 			xprt->stat.connect_time,
1869 			idle_time,
1870 			xprt->stat.sends,
1871 			xprt->stat.recvs,
1872 			xprt->stat.bad_xids,
1873 			xprt->stat.req_u,
1874 			xprt->stat.bklog_u);
1875 }
1876 
1877 static struct rpc_xprt_ops xs_udp_ops = {
1878 	.set_buffer_size	= xs_udp_set_buffer_size,
1879 	.reserve_xprt		= xprt_reserve_xprt_cong,
1880 	.release_xprt		= xprt_release_xprt_cong,
1881 	.rpcbind		= rpcb_getport_async,
1882 	.set_port		= xs_set_port,
1883 	.connect		= xs_connect,
1884 	.buf_alloc		= rpc_malloc,
1885 	.buf_free		= rpc_free,
1886 	.send_request		= xs_udp_send_request,
1887 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
1888 	.timer			= xs_udp_timer,
1889 	.release_request	= xprt_release_rqst_cong,
1890 	.close			= xs_close,
1891 	.destroy		= xs_destroy,
1892 	.print_stats		= xs_udp_print_stats,
1893 };
1894 
1895 static struct rpc_xprt_ops xs_tcp_ops = {
1896 	.reserve_xprt		= xprt_reserve_xprt,
1897 	.release_xprt		= xs_tcp_release_xprt,
1898 	.rpcbind		= rpcb_getport_async,
1899 	.set_port		= xs_set_port,
1900 	.connect		= xs_tcp_connect,
1901 	.buf_alloc		= rpc_malloc,
1902 	.buf_free		= rpc_free,
1903 	.send_request		= xs_tcp_send_request,
1904 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
1905 	.close			= xs_tcp_shutdown,
1906 	.destroy		= xs_destroy,
1907 	.print_stats		= xs_tcp_print_stats,
1908 };
1909 
1910 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
1911 				      unsigned int slot_table_size)
1912 {
1913 	struct rpc_xprt *xprt;
1914 	struct sock_xprt *new;
1915 
1916 	if (args->addrlen > sizeof(xprt->addr)) {
1917 		dprintk("RPC:       xs_setup_xprt: address too large\n");
1918 		return ERR_PTR(-EBADF);
1919 	}
1920 
1921 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1922 	if (new == NULL) {
1923 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
1924 				"rpc_xprt\n");
1925 		return ERR_PTR(-ENOMEM);
1926 	}
1927 	xprt = &new->xprt;
1928 
1929 	xprt->max_reqs = slot_table_size;
1930 	xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
1931 	if (xprt->slot == NULL) {
1932 		kfree(xprt);
1933 		dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
1934 				"table\n");
1935 		return ERR_PTR(-ENOMEM);
1936 	}
1937 
1938 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
1939 	xprt->addrlen = args->addrlen;
1940 	if (args->srcaddr)
1941 		memcpy(&new->addr, args->srcaddr, args->addrlen);
1942 
1943 	return xprt;
1944 }
1945 
1946 static const struct rpc_timeout xs_udp_default_timeout = {
1947 	.to_initval = 5 * HZ,
1948 	.to_maxval = 30 * HZ,
1949 	.to_increment = 5 * HZ,
1950 	.to_retries = 5,
1951 };
1952 
1953 /**
1954  * xs_setup_udp - Set up transport to use a UDP socket
1955  * @args: rpc transport creation arguments
1956  *
1957  */
1958 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
1959 {
1960 	struct sockaddr *addr = args->dstaddr;
1961 	struct rpc_xprt *xprt;
1962 	struct sock_xprt *transport;
1963 
1964 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
1965 	if (IS_ERR(xprt))
1966 		return xprt;
1967 	transport = container_of(xprt, struct sock_xprt, xprt);
1968 
1969 	xprt->prot = IPPROTO_UDP;
1970 	xprt->tsh_size = 0;
1971 	/* XXX: header size can vary due to auth type, IPv6, etc. */
1972 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1973 
1974 	xprt->bind_timeout = XS_BIND_TO;
1975 	xprt->connect_timeout = XS_UDP_CONN_TO;
1976 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
1977 	xprt->idle_timeout = XS_IDLE_DISC_TO;
1978 
1979 	xprt->ops = &xs_udp_ops;
1980 
1981 	xprt->timeout = &xs_udp_default_timeout;
1982 
1983 	switch (addr->sa_family) {
1984 	case AF_INET:
1985 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
1986 			xprt_set_bound(xprt);
1987 
1988 		INIT_DELAYED_WORK(&transport->connect_worker,
1989 					xs_udp_connect_worker4);
1990 		xs_format_ipv4_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
1991 		break;
1992 	case AF_INET6:
1993 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
1994 			xprt_set_bound(xprt);
1995 
1996 		INIT_DELAYED_WORK(&transport->connect_worker,
1997 					xs_udp_connect_worker6);
1998 		xs_format_ipv6_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
1999 		break;
2000 	default:
2001 		kfree(xprt);
2002 		return ERR_PTR(-EAFNOSUPPORT);
2003 	}
2004 
2005 	dprintk("RPC:       set up transport to address %s\n",
2006 			xprt->address_strings[RPC_DISPLAY_ALL]);
2007 
2008 	if (try_module_get(THIS_MODULE))
2009 		return xprt;
2010 
2011 	kfree(xprt->slot);
2012 	kfree(xprt);
2013 	return ERR_PTR(-EINVAL);
2014 }
2015 
2016 static const struct rpc_timeout xs_tcp_default_timeout = {
2017 	.to_initval = 60 * HZ,
2018 	.to_maxval = 60 * HZ,
2019 	.to_retries = 2,
2020 };
2021 
2022 /**
2023  * xs_setup_tcp - Set up transport to use a TCP socket
2024  * @args: rpc transport creation arguments
2025  *
2026  */
2027 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2028 {
2029 	struct sockaddr *addr = args->dstaddr;
2030 	struct rpc_xprt *xprt;
2031 	struct sock_xprt *transport;
2032 
2033 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2034 	if (IS_ERR(xprt))
2035 		return xprt;
2036 	transport = container_of(xprt, struct sock_xprt, xprt);
2037 
2038 	xprt->prot = IPPROTO_TCP;
2039 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2040 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2041 
2042 	xprt->bind_timeout = XS_BIND_TO;
2043 	xprt->connect_timeout = XS_TCP_CONN_TO;
2044 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2045 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2046 
2047 	xprt->ops = &xs_tcp_ops;
2048 	xprt->timeout = &xs_tcp_default_timeout;
2049 
2050 	switch (addr->sa_family) {
2051 	case AF_INET:
2052 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2053 			xprt_set_bound(xprt);
2054 
2055 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker4);
2056 		xs_format_ipv4_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2057 		break;
2058 	case AF_INET6:
2059 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2060 			xprt_set_bound(xprt);
2061 
2062 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker6);
2063 		xs_format_ipv6_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2064 		break;
2065 	default:
2066 		kfree(xprt);
2067 		return ERR_PTR(-EAFNOSUPPORT);
2068 	}
2069 
2070 	dprintk("RPC:       set up transport to address %s\n",
2071 			xprt->address_strings[RPC_DISPLAY_ALL]);
2072 
2073 	if (try_module_get(THIS_MODULE))
2074 		return xprt;
2075 
2076 	kfree(xprt->slot);
2077 	kfree(xprt);
2078 	return ERR_PTR(-EINVAL);
2079 }
2080 
2081 static struct xprt_class	xs_udp_transport = {
2082 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2083 	.name		= "udp",
2084 	.owner		= THIS_MODULE,
2085 	.ident		= IPPROTO_UDP,
2086 	.setup		= xs_setup_udp,
2087 };
2088 
2089 static struct xprt_class	xs_tcp_transport = {
2090 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2091 	.name		= "tcp",
2092 	.owner		= THIS_MODULE,
2093 	.ident		= IPPROTO_TCP,
2094 	.setup		= xs_setup_tcp,
2095 };
2096 
2097 /**
2098  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2099  *
2100  */
2101 int init_socket_xprt(void)
2102 {
2103 #ifdef RPC_DEBUG
2104 	if (!sunrpc_table_header)
2105 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2106 #endif
2107 
2108 	xprt_register_transport(&xs_udp_transport);
2109 	xprt_register_transport(&xs_tcp_transport);
2110 
2111 	return 0;
2112 }
2113 
2114 /**
2115  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2116  *
2117  */
2118 void cleanup_socket_xprt(void)
2119 {
2120 #ifdef RPC_DEBUG
2121 	if (sunrpc_table_header) {
2122 		unregister_sysctl_table(sunrpc_table_header);
2123 		sunrpc_table_header = NULL;
2124 	}
2125 #endif
2126 
2127 	xprt_unregister_transport(&xs_udp_transport);
2128 	xprt_unregister_transport(&xs_tcp_transport);
2129 }
2130