xref: /linux/net/sunrpc/xprtsock.c (revision 0c93ea4064a209cdc36de8a9a3003d43d08f46f7)
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 -ENOTSOCK;
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 	if (!xprt_bound(xprt))
581 		return -ENOTCONN;
582 	status = xs_sendpages(transport->sock,
583 			      xs_addr(xprt),
584 			      xprt->addrlen, xdr,
585 			      req->rq_bytes_sent);
586 
587 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
588 			xdr->len - req->rq_bytes_sent, status);
589 
590 	if (status >= 0) {
591 		task->tk_bytes_sent += status;
592 		if (status >= req->rq_slen)
593 			return 0;
594 		/* Still some bytes left; set up for a retry later. */
595 		status = -EAGAIN;
596 	}
597 
598 	switch (status) {
599 	case -ENOTSOCK:
600 		status = -ENOTCONN;
601 		/* Should we call xs_close() here? */
602 		break;
603 	case -EAGAIN:
604 		xs_nospace(task);
605 		break;
606 	case -ENETUNREACH:
607 	case -EPIPE:
608 	case -ECONNREFUSED:
609 		/* When the server has died, an ICMP port unreachable message
610 		 * prompts ECONNREFUSED. */
611 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
612 		break;
613 	default:
614 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
615 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
616 			-status);
617 	}
618 
619 	return status;
620 }
621 
622 /**
623  * xs_tcp_shutdown - gracefully shut down a TCP socket
624  * @xprt: transport
625  *
626  * Initiates a graceful shutdown of the TCP socket by calling the
627  * equivalent of shutdown(SHUT_WR);
628  */
629 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
630 {
631 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
632 	struct socket *sock = transport->sock;
633 
634 	if (sock != NULL)
635 		kernel_sock_shutdown(sock, SHUT_WR);
636 }
637 
638 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
639 {
640 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
641 	rpc_fraghdr *base = buf->head[0].iov_base;
642 	*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
643 }
644 
645 /**
646  * xs_tcp_send_request - write an RPC request to a TCP socket
647  * @task: address of RPC task that manages the state of an RPC request
648  *
649  * Return values:
650  *        0:	The request has been sent
651  *   EAGAIN:	The socket was blocked, please call again later to
652  *		complete the request
653  * ENOTCONN:	Caller needs to invoke connect logic then call again
654  *    other:	Some other error occured, the request was not sent
655  *
656  * XXX: In the case of soft timeouts, should we eventually give up
657  *	if sendmsg is not able to make progress?
658  */
659 static int xs_tcp_send_request(struct rpc_task *task)
660 {
661 	struct rpc_rqst *req = task->tk_rqstp;
662 	struct rpc_xprt *xprt = req->rq_xprt;
663 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
664 	struct xdr_buf *xdr = &req->rq_snd_buf;
665 	int status;
666 
667 	xs_encode_tcp_record_marker(&req->rq_snd_buf);
668 
669 	xs_pktdump("packet data:",
670 				req->rq_svec->iov_base,
671 				req->rq_svec->iov_len);
672 
673 	/* Continue transmitting the packet/record. We must be careful
674 	 * to cope with writespace callbacks arriving _after_ we have
675 	 * called sendmsg(). */
676 	while (1) {
677 		status = xs_sendpages(transport->sock,
678 					NULL, 0, xdr, req->rq_bytes_sent);
679 
680 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
681 				xdr->len - req->rq_bytes_sent, status);
682 
683 		if (unlikely(status < 0))
684 			break;
685 
686 		/* If we've sent the entire packet, immediately
687 		 * reset the count of bytes sent. */
688 		req->rq_bytes_sent += status;
689 		task->tk_bytes_sent += status;
690 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
691 			req->rq_bytes_sent = 0;
692 			return 0;
693 		}
694 
695 		if (status != 0)
696 			continue;
697 		status = -EAGAIN;
698 		break;
699 	}
700 
701 	switch (status) {
702 	case -ENOTSOCK:
703 		status = -ENOTCONN;
704 		/* Should we call xs_close() here? */
705 		break;
706 	case -EAGAIN:
707 		xs_nospace(task);
708 		break;
709 	case -ECONNRESET:
710 		xs_tcp_shutdown(xprt);
711 	case -ECONNREFUSED:
712 	case -ENOTCONN:
713 	case -EPIPE:
714 		status = -ENOTCONN;
715 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
716 		break;
717 	default:
718 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
719 			-status);
720 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
721 		xs_tcp_shutdown(xprt);
722 	}
723 
724 	return status;
725 }
726 
727 /**
728  * xs_tcp_release_xprt - clean up after a tcp transmission
729  * @xprt: transport
730  * @task: rpc task
731  *
732  * This cleans up if an error causes us to abort the transmission of a request.
733  * In this case, the socket may need to be reset in order to avoid confusing
734  * the server.
735  */
736 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
737 {
738 	struct rpc_rqst *req;
739 
740 	if (task != xprt->snd_task)
741 		return;
742 	if (task == NULL)
743 		goto out_release;
744 	req = task->tk_rqstp;
745 	if (req->rq_bytes_sent == 0)
746 		goto out_release;
747 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
748 		goto out_release;
749 	set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
750 out_release:
751 	xprt_release_xprt(xprt, task);
752 }
753 
754 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
755 {
756 	transport->old_data_ready = sk->sk_data_ready;
757 	transport->old_state_change = sk->sk_state_change;
758 	transport->old_write_space = sk->sk_write_space;
759 	transport->old_error_report = sk->sk_error_report;
760 }
761 
762 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
763 {
764 	sk->sk_data_ready = transport->old_data_ready;
765 	sk->sk_state_change = transport->old_state_change;
766 	sk->sk_write_space = transport->old_write_space;
767 	sk->sk_error_report = transport->old_error_report;
768 }
769 
770 /**
771  * xs_close - close a socket
772  * @xprt: transport
773  *
774  * This is used when all requests are complete; ie, no DRC state remains
775  * on the server we want to save.
776  */
777 static void xs_close(struct rpc_xprt *xprt)
778 {
779 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
780 	struct socket *sock = transport->sock;
781 	struct sock *sk = transport->inet;
782 
783 	if (!sk)
784 		goto clear_close_wait;
785 
786 	dprintk("RPC:       xs_close xprt %p\n", xprt);
787 
788 	write_lock_bh(&sk->sk_callback_lock);
789 	transport->inet = NULL;
790 	transport->sock = NULL;
791 
792 	sk->sk_user_data = NULL;
793 
794 	xs_restore_old_callbacks(transport, sk);
795 	write_unlock_bh(&sk->sk_callback_lock);
796 
797 	sk->sk_no_check = 0;
798 
799 	sock_release(sock);
800 clear_close_wait:
801 	smp_mb__before_clear_bit();
802 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
803 	clear_bit(XPRT_CLOSING, &xprt->state);
804 	smp_mb__after_clear_bit();
805 	xprt_disconnect_done(xprt);
806 }
807 
808 /**
809  * xs_destroy - prepare to shutdown a transport
810  * @xprt: doomed transport
811  *
812  */
813 static void xs_destroy(struct rpc_xprt *xprt)
814 {
815 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
816 
817 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
818 
819 	cancel_rearming_delayed_work(&transport->connect_worker);
820 
821 	xs_close(xprt);
822 	xs_free_peer_addresses(xprt);
823 	kfree(xprt->slot);
824 	kfree(xprt);
825 	module_put(THIS_MODULE);
826 }
827 
828 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
829 {
830 	return (struct rpc_xprt *) sk->sk_user_data;
831 }
832 
833 /**
834  * xs_udp_data_ready - "data ready" callback for UDP sockets
835  * @sk: socket with data to read
836  * @len: how much data to read
837  *
838  */
839 static void xs_udp_data_ready(struct sock *sk, int len)
840 {
841 	struct rpc_task *task;
842 	struct rpc_xprt *xprt;
843 	struct rpc_rqst *rovr;
844 	struct sk_buff *skb;
845 	int err, repsize, copied;
846 	u32 _xid;
847 	__be32 *xp;
848 
849 	read_lock(&sk->sk_callback_lock);
850 	dprintk("RPC:       xs_udp_data_ready...\n");
851 	if (!(xprt = xprt_from_sock(sk)))
852 		goto out;
853 
854 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
855 		goto out;
856 
857 	if (xprt->shutdown)
858 		goto dropit;
859 
860 	repsize = skb->len - sizeof(struct udphdr);
861 	if (repsize < 4) {
862 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
863 		goto dropit;
864 	}
865 
866 	/* Copy the XID from the skb... */
867 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
868 				sizeof(_xid), &_xid);
869 	if (xp == NULL)
870 		goto dropit;
871 
872 	/* Look up and lock the request corresponding to the given XID */
873 	spin_lock(&xprt->transport_lock);
874 	rovr = xprt_lookup_rqst(xprt, *xp);
875 	if (!rovr)
876 		goto out_unlock;
877 	task = rovr->rq_task;
878 
879 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
880 		copied = repsize;
881 
882 	/* Suck it into the iovec, verify checksum if not done by hw. */
883 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
884 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
885 		goto out_unlock;
886 	}
887 
888 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
889 
890 	/* Something worked... */
891 	dst_confirm(skb->dst);
892 
893 	xprt_adjust_cwnd(task, copied);
894 	xprt_update_rtt(task);
895 	xprt_complete_rqst(task, copied);
896 
897  out_unlock:
898 	spin_unlock(&xprt->transport_lock);
899  dropit:
900 	skb_free_datagram(sk, skb);
901  out:
902 	read_unlock(&sk->sk_callback_lock);
903 }
904 
905 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
906 {
907 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
908 	size_t len, used;
909 	char *p;
910 
911 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
912 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
913 	used = xdr_skb_read_bits(desc, p, len);
914 	transport->tcp_offset += used;
915 	if (used != len)
916 		return;
917 
918 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
919 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
920 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
921 	else
922 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
923 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
924 
925 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
926 	transport->tcp_offset = 0;
927 
928 	/* Sanity check of the record length */
929 	if (unlikely(transport->tcp_reclen < 4)) {
930 		dprintk("RPC:       invalid TCP record fragment length\n");
931 		xprt_force_disconnect(xprt);
932 		return;
933 	}
934 	dprintk("RPC:       reading TCP record fragment of length %d\n",
935 			transport->tcp_reclen);
936 }
937 
938 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
939 {
940 	if (transport->tcp_offset == transport->tcp_reclen) {
941 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
942 		transport->tcp_offset = 0;
943 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
944 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
945 			transport->tcp_flags |= TCP_RCV_COPY_XID;
946 			transport->tcp_copied = 0;
947 		}
948 	}
949 }
950 
951 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
952 {
953 	size_t len, used;
954 	char *p;
955 
956 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
957 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
958 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
959 	used = xdr_skb_read_bits(desc, p, len);
960 	transport->tcp_offset += used;
961 	if (used != len)
962 		return;
963 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
964 	transport->tcp_flags |= TCP_RCV_COPY_DATA;
965 	transport->tcp_copied = 4;
966 	dprintk("RPC:       reading reply for XID %08x\n",
967 			ntohl(transport->tcp_xid));
968 	xs_tcp_check_fraghdr(transport);
969 }
970 
971 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
972 {
973 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
974 	struct rpc_rqst *req;
975 	struct xdr_buf *rcvbuf;
976 	size_t len;
977 	ssize_t r;
978 
979 	/* Find and lock the request corresponding to this xid */
980 	spin_lock(&xprt->transport_lock);
981 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
982 	if (!req) {
983 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
984 		dprintk("RPC:       XID %08x request not found!\n",
985 				ntohl(transport->tcp_xid));
986 		spin_unlock(&xprt->transport_lock);
987 		return;
988 	}
989 
990 	rcvbuf = &req->rq_private_buf;
991 	len = desc->count;
992 	if (len > transport->tcp_reclen - transport->tcp_offset) {
993 		struct xdr_skb_reader my_desc;
994 
995 		len = transport->tcp_reclen - transport->tcp_offset;
996 		memcpy(&my_desc, desc, sizeof(my_desc));
997 		my_desc.count = len;
998 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
999 					  &my_desc, xdr_skb_read_bits);
1000 		desc->count -= r;
1001 		desc->offset += r;
1002 	} else
1003 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1004 					  desc, xdr_skb_read_bits);
1005 
1006 	if (r > 0) {
1007 		transport->tcp_copied += r;
1008 		transport->tcp_offset += r;
1009 	}
1010 	if (r != len) {
1011 		/* Error when copying to the receive buffer,
1012 		 * usually because we weren't able to allocate
1013 		 * additional buffer pages. All we can do now
1014 		 * is turn off TCP_RCV_COPY_DATA, so the request
1015 		 * will not receive any additional updates,
1016 		 * and time out.
1017 		 * Any remaining data from this record will
1018 		 * be discarded.
1019 		 */
1020 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1021 		dprintk("RPC:       XID %08x truncated request\n",
1022 				ntohl(transport->tcp_xid));
1023 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1024 				"tcp_offset = %u, tcp_reclen = %u\n",
1025 				xprt, transport->tcp_copied,
1026 				transport->tcp_offset, transport->tcp_reclen);
1027 		goto out;
1028 	}
1029 
1030 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1031 			ntohl(transport->tcp_xid), r);
1032 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1033 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1034 			transport->tcp_offset, transport->tcp_reclen);
1035 
1036 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1037 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1038 	else if (transport->tcp_offset == transport->tcp_reclen) {
1039 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1040 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1041 	}
1042 
1043 out:
1044 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1045 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1046 	spin_unlock(&xprt->transport_lock);
1047 	xs_tcp_check_fraghdr(transport);
1048 }
1049 
1050 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1051 {
1052 	size_t len;
1053 
1054 	len = transport->tcp_reclen - transport->tcp_offset;
1055 	if (len > desc->count)
1056 		len = desc->count;
1057 	desc->count -= len;
1058 	desc->offset += len;
1059 	transport->tcp_offset += len;
1060 	dprintk("RPC:       discarded %Zu bytes\n", len);
1061 	xs_tcp_check_fraghdr(transport);
1062 }
1063 
1064 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1065 {
1066 	struct rpc_xprt *xprt = rd_desc->arg.data;
1067 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1068 	struct xdr_skb_reader desc = {
1069 		.skb	= skb,
1070 		.offset	= offset,
1071 		.count	= len,
1072 	};
1073 
1074 	dprintk("RPC:       xs_tcp_data_recv started\n");
1075 	do {
1076 		/* Read in a new fragment marker if necessary */
1077 		/* Can we ever really expect to get completely empty fragments? */
1078 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1079 			xs_tcp_read_fraghdr(xprt, &desc);
1080 			continue;
1081 		}
1082 		/* Read in the xid if necessary */
1083 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1084 			xs_tcp_read_xid(transport, &desc);
1085 			continue;
1086 		}
1087 		/* Read in the request data */
1088 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1089 			xs_tcp_read_request(xprt, &desc);
1090 			continue;
1091 		}
1092 		/* Skip over any trailing bytes on short reads */
1093 		xs_tcp_read_discard(transport, &desc);
1094 	} while (desc.count);
1095 	dprintk("RPC:       xs_tcp_data_recv done\n");
1096 	return len - desc.count;
1097 }
1098 
1099 /**
1100  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1101  * @sk: socket with data to read
1102  * @bytes: how much data to read
1103  *
1104  */
1105 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1106 {
1107 	struct rpc_xprt *xprt;
1108 	read_descriptor_t rd_desc;
1109 	int read;
1110 
1111 	dprintk("RPC:       xs_tcp_data_ready...\n");
1112 
1113 	read_lock(&sk->sk_callback_lock);
1114 	if (!(xprt = xprt_from_sock(sk)))
1115 		goto out;
1116 	if (xprt->shutdown)
1117 		goto out;
1118 
1119 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1120 	rd_desc.arg.data = xprt;
1121 	do {
1122 		rd_desc.count = 65536;
1123 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1124 	} while (read > 0);
1125 out:
1126 	read_unlock(&sk->sk_callback_lock);
1127 }
1128 
1129 /**
1130  * xs_tcp_state_change - callback to handle TCP socket state changes
1131  * @sk: socket whose state has changed
1132  *
1133  */
1134 static void xs_tcp_state_change(struct sock *sk)
1135 {
1136 	struct rpc_xprt *xprt;
1137 
1138 	read_lock(&sk->sk_callback_lock);
1139 	if (!(xprt = xprt_from_sock(sk)))
1140 		goto out;
1141 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1142 	dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1143 			sk->sk_state, xprt_connected(xprt),
1144 			sock_flag(sk, SOCK_DEAD),
1145 			sock_flag(sk, SOCK_ZAPPED));
1146 
1147 	switch (sk->sk_state) {
1148 	case TCP_ESTABLISHED:
1149 		spin_lock_bh(&xprt->transport_lock);
1150 		if (!xprt_test_and_set_connected(xprt)) {
1151 			struct sock_xprt *transport = container_of(xprt,
1152 					struct sock_xprt, xprt);
1153 
1154 			/* Reset TCP record info */
1155 			transport->tcp_offset = 0;
1156 			transport->tcp_reclen = 0;
1157 			transport->tcp_copied = 0;
1158 			transport->tcp_flags =
1159 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1160 
1161 			xprt_wake_pending_tasks(xprt, 0);
1162 		}
1163 		spin_unlock_bh(&xprt->transport_lock);
1164 		break;
1165 	case TCP_FIN_WAIT1:
1166 		/* The client initiated a shutdown of the socket */
1167 		xprt->connect_cookie++;
1168 		xprt->reestablish_timeout = 0;
1169 		set_bit(XPRT_CLOSING, &xprt->state);
1170 		smp_mb__before_clear_bit();
1171 		clear_bit(XPRT_CONNECTED, &xprt->state);
1172 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1173 		smp_mb__after_clear_bit();
1174 		break;
1175 	case TCP_CLOSE_WAIT:
1176 		/* The server initiated a shutdown of the socket */
1177 		set_bit(XPRT_CLOSING, &xprt->state);
1178 		xprt_force_disconnect(xprt);
1179 	case TCP_SYN_SENT:
1180 		xprt->connect_cookie++;
1181 	case TCP_CLOSING:
1182 		/*
1183 		 * If the server closed down the connection, make sure that
1184 		 * we back off before reconnecting
1185 		 */
1186 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1187 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1188 		break;
1189 	case TCP_LAST_ACK:
1190 		smp_mb__before_clear_bit();
1191 		clear_bit(XPRT_CONNECTED, &xprt->state);
1192 		smp_mb__after_clear_bit();
1193 		break;
1194 	case TCP_CLOSE:
1195 		smp_mb__before_clear_bit();
1196 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1197 		clear_bit(XPRT_CLOSING, &xprt->state);
1198 		smp_mb__after_clear_bit();
1199 		/* Mark transport as closed and wake up all pending tasks */
1200 		xprt_disconnect_done(xprt);
1201 	}
1202  out:
1203 	read_unlock(&sk->sk_callback_lock);
1204 }
1205 
1206 /**
1207  * xs_tcp_error_report - callback mainly for catching RST events
1208  * @sk: socket
1209  */
1210 static void xs_tcp_error_report(struct sock *sk)
1211 {
1212 	struct rpc_xprt *xprt;
1213 
1214 	read_lock(&sk->sk_callback_lock);
1215 	if (sk->sk_err != ECONNRESET || sk->sk_state != TCP_ESTABLISHED)
1216 		goto out;
1217 	if (!(xprt = xprt_from_sock(sk)))
1218 		goto out;
1219 	dprintk("RPC:       %s client %p...\n"
1220 			"RPC:       error %d\n",
1221 			__func__, xprt, sk->sk_err);
1222 
1223 	xprt_force_disconnect(xprt);
1224 out:
1225 	read_unlock(&sk->sk_callback_lock);
1226 }
1227 
1228 /**
1229  * xs_udp_write_space - callback invoked when socket buffer space
1230  *                             becomes available
1231  * @sk: socket whose state has changed
1232  *
1233  * Called when more output buffer space is available for this socket.
1234  * We try not to wake our writers until they can make "significant"
1235  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1236  * with a bunch of small requests.
1237  */
1238 static void xs_udp_write_space(struct sock *sk)
1239 {
1240 	read_lock(&sk->sk_callback_lock);
1241 
1242 	/* from net/core/sock.c:sock_def_write_space */
1243 	if (sock_writeable(sk)) {
1244 		struct socket *sock;
1245 		struct rpc_xprt *xprt;
1246 
1247 		if (unlikely(!(sock = sk->sk_socket)))
1248 			goto out;
1249 		clear_bit(SOCK_NOSPACE, &sock->flags);
1250 
1251 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1252 			goto out;
1253 		if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1254 			goto out;
1255 
1256 		xprt_write_space(xprt);
1257 	}
1258 
1259  out:
1260 	read_unlock(&sk->sk_callback_lock);
1261 }
1262 
1263 /**
1264  * xs_tcp_write_space - callback invoked when socket buffer space
1265  *                             becomes available
1266  * @sk: socket whose state has changed
1267  *
1268  * Called when more output buffer space is available for this socket.
1269  * We try not to wake our writers until they can make "significant"
1270  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1271  * with a bunch of small requests.
1272  */
1273 static void xs_tcp_write_space(struct sock *sk)
1274 {
1275 	read_lock(&sk->sk_callback_lock);
1276 
1277 	/* from net/core/stream.c:sk_stream_write_space */
1278 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
1279 		struct socket *sock;
1280 		struct rpc_xprt *xprt;
1281 
1282 		if (unlikely(!(sock = sk->sk_socket)))
1283 			goto out;
1284 		clear_bit(SOCK_NOSPACE, &sock->flags);
1285 
1286 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1287 			goto out;
1288 		if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1289 			goto out;
1290 
1291 		xprt_write_space(xprt);
1292 	}
1293 
1294  out:
1295 	read_unlock(&sk->sk_callback_lock);
1296 }
1297 
1298 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1299 {
1300 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1301 	struct sock *sk = transport->inet;
1302 
1303 	if (transport->rcvsize) {
1304 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1305 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1306 	}
1307 	if (transport->sndsize) {
1308 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1309 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1310 		sk->sk_write_space(sk);
1311 	}
1312 }
1313 
1314 /**
1315  * xs_udp_set_buffer_size - set send and receive limits
1316  * @xprt: generic transport
1317  * @sndsize: requested size of send buffer, in bytes
1318  * @rcvsize: requested size of receive buffer, in bytes
1319  *
1320  * Set socket send and receive buffer size limits.
1321  */
1322 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1323 {
1324 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1325 
1326 	transport->sndsize = 0;
1327 	if (sndsize)
1328 		transport->sndsize = sndsize + 1024;
1329 	transport->rcvsize = 0;
1330 	if (rcvsize)
1331 		transport->rcvsize = rcvsize + 1024;
1332 
1333 	xs_udp_do_set_buffer_size(xprt);
1334 }
1335 
1336 /**
1337  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1338  * @task: task that timed out
1339  *
1340  * Adjust the congestion window after a retransmit timeout has occurred.
1341  */
1342 static void xs_udp_timer(struct rpc_task *task)
1343 {
1344 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1345 }
1346 
1347 static unsigned short xs_get_random_port(void)
1348 {
1349 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1350 	unsigned short rand = (unsigned short) net_random() % range;
1351 	return rand + xprt_min_resvport;
1352 }
1353 
1354 /**
1355  * xs_set_port - reset the port number in the remote endpoint address
1356  * @xprt: generic transport
1357  * @port: new port number
1358  *
1359  */
1360 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1361 {
1362 	struct sockaddr *addr = xs_addr(xprt);
1363 
1364 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1365 
1366 	switch (addr->sa_family) {
1367 	case AF_INET:
1368 		((struct sockaddr_in *)addr)->sin_port = htons(port);
1369 		break;
1370 	case AF_INET6:
1371 		((struct sockaddr_in6 *)addr)->sin6_port = htons(port);
1372 		break;
1373 	default:
1374 		BUG();
1375 	}
1376 }
1377 
1378 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1379 {
1380 	unsigned short port = transport->port;
1381 
1382 	if (port == 0 && transport->xprt.resvport)
1383 		port = xs_get_random_port();
1384 	return port;
1385 }
1386 
1387 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1388 {
1389 	if (transport->port != 0)
1390 		transport->port = 0;
1391 	if (!transport->xprt.resvport)
1392 		return 0;
1393 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1394 		return xprt_max_resvport;
1395 	return --port;
1396 }
1397 
1398 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1399 {
1400 	struct sockaddr_in myaddr = {
1401 		.sin_family = AF_INET,
1402 	};
1403 	struct sockaddr_in *sa;
1404 	int err, nloop = 0;
1405 	unsigned short port = xs_get_srcport(transport, sock);
1406 	unsigned short last;
1407 
1408 	sa = (struct sockaddr_in *)&transport->addr;
1409 	myaddr.sin_addr = sa->sin_addr;
1410 	do {
1411 		myaddr.sin_port = htons(port);
1412 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1413 						sizeof(myaddr));
1414 		if (port == 0)
1415 			break;
1416 		if (err == 0) {
1417 			transport->port = port;
1418 			break;
1419 		}
1420 		last = port;
1421 		port = xs_next_srcport(transport, sock, port);
1422 		if (port > last)
1423 			nloop++;
1424 	} while (err == -EADDRINUSE && nloop != 2);
1425 	dprintk("RPC:       %s %pI4:%u: %s (%d)\n",
1426 			__func__, &myaddr.sin_addr,
1427 			port, err ? "failed" : "ok", err);
1428 	return err;
1429 }
1430 
1431 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1432 {
1433 	struct sockaddr_in6 myaddr = {
1434 		.sin6_family = AF_INET6,
1435 	};
1436 	struct sockaddr_in6 *sa;
1437 	int err, nloop = 0;
1438 	unsigned short port = xs_get_srcport(transport, sock);
1439 	unsigned short last;
1440 
1441 	sa = (struct sockaddr_in6 *)&transport->addr;
1442 	myaddr.sin6_addr = sa->sin6_addr;
1443 	do {
1444 		myaddr.sin6_port = htons(port);
1445 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1446 						sizeof(myaddr));
1447 		if (port == 0)
1448 			break;
1449 		if (err == 0) {
1450 			transport->port = port;
1451 			break;
1452 		}
1453 		last = port;
1454 		port = xs_next_srcport(transport, sock, port);
1455 		if (port > last)
1456 			nloop++;
1457 	} while (err == -EADDRINUSE && nloop != 2);
1458 	dprintk("RPC:       xs_bind6 %pI6:%u: %s (%d)\n",
1459 		&myaddr.sin6_addr, port, err ? "failed" : "ok", err);
1460 	return err;
1461 }
1462 
1463 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1464 static struct lock_class_key xs_key[2];
1465 static struct lock_class_key xs_slock_key[2];
1466 
1467 static inline void xs_reclassify_socket4(struct socket *sock)
1468 {
1469 	struct sock *sk = sock->sk;
1470 
1471 	BUG_ON(sock_owned_by_user(sk));
1472 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1473 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1474 }
1475 
1476 static inline void xs_reclassify_socket6(struct socket *sock)
1477 {
1478 	struct sock *sk = sock->sk;
1479 
1480 	BUG_ON(sock_owned_by_user(sk));
1481 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1482 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1483 }
1484 #else
1485 static inline void xs_reclassify_socket4(struct socket *sock)
1486 {
1487 }
1488 
1489 static inline void xs_reclassify_socket6(struct socket *sock)
1490 {
1491 }
1492 #endif
1493 
1494 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1495 {
1496 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1497 
1498 	if (!transport->inet) {
1499 		struct sock *sk = sock->sk;
1500 
1501 		write_lock_bh(&sk->sk_callback_lock);
1502 
1503 		xs_save_old_callbacks(transport, sk);
1504 
1505 		sk->sk_user_data = xprt;
1506 		sk->sk_data_ready = xs_udp_data_ready;
1507 		sk->sk_write_space = xs_udp_write_space;
1508 		sk->sk_no_check = UDP_CSUM_NORCV;
1509 		sk->sk_allocation = GFP_ATOMIC;
1510 
1511 		xprt_set_connected(xprt);
1512 
1513 		/* Reset to new socket */
1514 		transport->sock = sock;
1515 		transport->inet = sk;
1516 
1517 		write_unlock_bh(&sk->sk_callback_lock);
1518 	}
1519 	xs_udp_do_set_buffer_size(xprt);
1520 }
1521 
1522 /**
1523  * xs_udp_connect_worker4 - set up a UDP socket
1524  * @work: RPC transport to connect
1525  *
1526  * Invoked by a work queue tasklet.
1527  */
1528 static void xs_udp_connect_worker4(struct work_struct *work)
1529 {
1530 	struct sock_xprt *transport =
1531 		container_of(work, struct sock_xprt, connect_worker.work);
1532 	struct rpc_xprt *xprt = &transport->xprt;
1533 	struct socket *sock = transport->sock;
1534 	int err, status = -EIO;
1535 
1536 	if (xprt->shutdown)
1537 		goto out;
1538 
1539 	/* Start by resetting any existing state */
1540 	xs_close(xprt);
1541 
1542 	if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1543 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1544 		goto out;
1545 	}
1546 	xs_reclassify_socket4(sock);
1547 
1548 	if (xs_bind4(transport, sock)) {
1549 		sock_release(sock);
1550 		goto out;
1551 	}
1552 
1553 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1554 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1555 
1556 	xs_udp_finish_connecting(xprt, sock);
1557 	status = 0;
1558 out:
1559 	xprt_wake_pending_tasks(xprt, status);
1560 	xprt_clear_connecting(xprt);
1561 }
1562 
1563 /**
1564  * xs_udp_connect_worker6 - set up a UDP socket
1565  * @work: RPC transport to connect
1566  *
1567  * Invoked by a work queue tasklet.
1568  */
1569 static void xs_udp_connect_worker6(struct work_struct *work)
1570 {
1571 	struct sock_xprt *transport =
1572 		container_of(work, struct sock_xprt, connect_worker.work);
1573 	struct rpc_xprt *xprt = &transport->xprt;
1574 	struct socket *sock = transport->sock;
1575 	int err, status = -EIO;
1576 
1577 	if (xprt->shutdown)
1578 		goto out;
1579 
1580 	/* Start by resetting any existing state */
1581 	xs_close(xprt);
1582 
1583 	if ((err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1584 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1585 		goto out;
1586 	}
1587 	xs_reclassify_socket6(sock);
1588 
1589 	if (xs_bind6(transport, sock) < 0) {
1590 		sock_release(sock);
1591 		goto out;
1592 	}
1593 
1594 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1595 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1596 
1597 	xs_udp_finish_connecting(xprt, sock);
1598 	status = 0;
1599 out:
1600 	xprt_wake_pending_tasks(xprt, status);
1601 	xprt_clear_connecting(xprt);
1602 }
1603 
1604 /*
1605  * We need to preserve the port number so the reply cache on the server can
1606  * find our cached RPC replies when we get around to reconnecting.
1607  */
1608 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1609 {
1610 	int result;
1611 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1612 	struct sockaddr any;
1613 
1614 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1615 
1616 	/*
1617 	 * Disconnect the transport socket by doing a connect operation
1618 	 * with AF_UNSPEC.  This should return immediately...
1619 	 */
1620 	memset(&any, 0, sizeof(any));
1621 	any.sa_family = AF_UNSPEC;
1622 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1623 	if (result)
1624 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1625 				result);
1626 }
1627 
1628 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1629 {
1630 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1631 
1632 	if (!transport->inet) {
1633 		struct sock *sk = sock->sk;
1634 
1635 		write_lock_bh(&sk->sk_callback_lock);
1636 
1637 		xs_save_old_callbacks(transport, sk);
1638 
1639 		sk->sk_user_data = xprt;
1640 		sk->sk_data_ready = xs_tcp_data_ready;
1641 		sk->sk_state_change = xs_tcp_state_change;
1642 		sk->sk_write_space = xs_tcp_write_space;
1643 		sk->sk_error_report = xs_tcp_error_report;
1644 		sk->sk_allocation = GFP_ATOMIC;
1645 
1646 		/* socket options */
1647 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1648 		sock_reset_flag(sk, SOCK_LINGER);
1649 		tcp_sk(sk)->linger2 = 0;
1650 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1651 
1652 		xprt_clear_connected(xprt);
1653 
1654 		/* Reset to new socket */
1655 		transport->sock = sock;
1656 		transport->inet = sk;
1657 
1658 		write_unlock_bh(&sk->sk_callback_lock);
1659 	}
1660 
1661 	if (!xprt_bound(xprt))
1662 		return -ENOTCONN;
1663 
1664 	/* Tell the socket layer to start connecting... */
1665 	xprt->stat.connect_count++;
1666 	xprt->stat.connect_start = jiffies;
1667 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1668 }
1669 
1670 /**
1671  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1672  * @work: RPC transport to connect
1673  *
1674  * Invoked by a work queue tasklet.
1675  */
1676 static void xs_tcp_connect_worker4(struct work_struct *work)
1677 {
1678 	struct sock_xprt *transport =
1679 		container_of(work, struct sock_xprt, connect_worker.work);
1680 	struct rpc_xprt *xprt = &transport->xprt;
1681 	struct socket *sock = transport->sock;
1682 	int err, status = -EIO;
1683 
1684 	if (xprt->shutdown)
1685 		goto out;
1686 
1687 	if (!sock) {
1688 		/* start from scratch */
1689 		if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1690 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1691 			goto out;
1692 		}
1693 		xs_reclassify_socket4(sock);
1694 
1695 		if (xs_bind4(transport, sock) < 0) {
1696 			sock_release(sock);
1697 			goto out;
1698 		}
1699 	} else
1700 		/* "close" the socket, preserving the local port */
1701 		xs_tcp_reuse_connection(xprt);
1702 
1703 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1704 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1705 
1706 	status = xs_tcp_finish_connecting(xprt, sock);
1707 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1708 			xprt, -status, xprt_connected(xprt),
1709 			sock->sk->sk_state);
1710 	if (status < 0) {
1711 		switch (status) {
1712 			case -EINPROGRESS:
1713 			case -EALREADY:
1714 				goto out_clear;
1715 			case -ECONNREFUSED:
1716 			case -ECONNRESET:
1717 				/* retry with existing socket, after a delay */
1718 				break;
1719 			default:
1720 				/* get rid of existing socket, and retry */
1721 				xs_tcp_shutdown(xprt);
1722 		}
1723 	}
1724 out:
1725 	xprt_wake_pending_tasks(xprt, status);
1726 out_clear:
1727 	xprt_clear_connecting(xprt);
1728 }
1729 
1730 /**
1731  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1732  * @work: RPC transport to connect
1733  *
1734  * Invoked by a work queue tasklet.
1735  */
1736 static void xs_tcp_connect_worker6(struct work_struct *work)
1737 {
1738 	struct sock_xprt *transport =
1739 		container_of(work, struct sock_xprt, connect_worker.work);
1740 	struct rpc_xprt *xprt = &transport->xprt;
1741 	struct socket *sock = transport->sock;
1742 	int err, status = -EIO;
1743 
1744 	if (xprt->shutdown)
1745 		goto out;
1746 
1747 	if (!sock) {
1748 		/* start from scratch */
1749 		if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1750 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1751 			goto out;
1752 		}
1753 		xs_reclassify_socket6(sock);
1754 
1755 		if (xs_bind6(transport, sock) < 0) {
1756 			sock_release(sock);
1757 			goto out;
1758 		}
1759 	} else
1760 		/* "close" the socket, preserving the local port */
1761 		xs_tcp_reuse_connection(xprt);
1762 
1763 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1764 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1765 
1766 	status = xs_tcp_finish_connecting(xprt, sock);
1767 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1768 			xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1769 	if (status < 0) {
1770 		switch (status) {
1771 			case -EINPROGRESS:
1772 			case -EALREADY:
1773 				goto out_clear;
1774 			case -ECONNREFUSED:
1775 			case -ECONNRESET:
1776 				/* retry with existing socket, after a delay */
1777 				break;
1778 			default:
1779 				/* get rid of existing socket, and retry */
1780 				xs_tcp_shutdown(xprt);
1781 		}
1782 	}
1783 out:
1784 	xprt_wake_pending_tasks(xprt, status);
1785 out_clear:
1786 	xprt_clear_connecting(xprt);
1787 }
1788 
1789 /**
1790  * xs_connect - connect a socket to a remote endpoint
1791  * @task: address of RPC task that manages state of connect request
1792  *
1793  * TCP: If the remote end dropped the connection, delay reconnecting.
1794  *
1795  * UDP socket connects are synchronous, but we use a work queue anyway
1796  * to guarantee that even unprivileged user processes can set up a
1797  * socket on a privileged port.
1798  *
1799  * If a UDP socket connect fails, the delay behavior here prevents
1800  * retry floods (hard mounts).
1801  */
1802 static void xs_connect(struct rpc_task *task)
1803 {
1804 	struct rpc_xprt *xprt = task->tk_xprt;
1805 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1806 
1807 	if (xprt_test_and_set_connecting(xprt))
1808 		return;
1809 
1810 	if (transport->sock != NULL) {
1811 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
1812 				"seconds\n",
1813 				xprt, xprt->reestablish_timeout / HZ);
1814 		queue_delayed_work(rpciod_workqueue,
1815 				   &transport->connect_worker,
1816 				   xprt->reestablish_timeout);
1817 		xprt->reestablish_timeout <<= 1;
1818 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1819 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1820 	} else {
1821 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
1822 		queue_delayed_work(rpciod_workqueue,
1823 				   &transport->connect_worker, 0);
1824 	}
1825 }
1826 
1827 static void xs_tcp_connect(struct rpc_task *task)
1828 {
1829 	struct rpc_xprt *xprt = task->tk_xprt;
1830 
1831 	/* Initiate graceful shutdown of the socket if not already done */
1832 	if (test_bit(XPRT_CONNECTED, &xprt->state))
1833 		xs_tcp_shutdown(xprt);
1834 	/* Exit if we need to wait for socket shutdown to complete */
1835 	if (test_bit(XPRT_CLOSING, &xprt->state))
1836 		return;
1837 	xs_connect(task);
1838 }
1839 
1840 /**
1841  * xs_udp_print_stats - display UDP socket-specifc stats
1842  * @xprt: rpc_xprt struct containing statistics
1843  * @seq: output file
1844  *
1845  */
1846 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1847 {
1848 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1849 
1850 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1851 			transport->port,
1852 			xprt->stat.bind_count,
1853 			xprt->stat.sends,
1854 			xprt->stat.recvs,
1855 			xprt->stat.bad_xids,
1856 			xprt->stat.req_u,
1857 			xprt->stat.bklog_u);
1858 }
1859 
1860 /**
1861  * xs_tcp_print_stats - display TCP socket-specifc stats
1862  * @xprt: rpc_xprt struct containing statistics
1863  * @seq: output file
1864  *
1865  */
1866 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1867 {
1868 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1869 	long idle_time = 0;
1870 
1871 	if (xprt_connected(xprt))
1872 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
1873 
1874 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1875 			transport->port,
1876 			xprt->stat.bind_count,
1877 			xprt->stat.connect_count,
1878 			xprt->stat.connect_time,
1879 			idle_time,
1880 			xprt->stat.sends,
1881 			xprt->stat.recvs,
1882 			xprt->stat.bad_xids,
1883 			xprt->stat.req_u,
1884 			xprt->stat.bklog_u);
1885 }
1886 
1887 static struct rpc_xprt_ops xs_udp_ops = {
1888 	.set_buffer_size	= xs_udp_set_buffer_size,
1889 	.reserve_xprt		= xprt_reserve_xprt_cong,
1890 	.release_xprt		= xprt_release_xprt_cong,
1891 	.rpcbind		= rpcb_getport_async,
1892 	.set_port		= xs_set_port,
1893 	.connect		= xs_connect,
1894 	.buf_alloc		= rpc_malloc,
1895 	.buf_free		= rpc_free,
1896 	.send_request		= xs_udp_send_request,
1897 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
1898 	.timer			= xs_udp_timer,
1899 	.release_request	= xprt_release_rqst_cong,
1900 	.close			= xs_close,
1901 	.destroy		= xs_destroy,
1902 	.print_stats		= xs_udp_print_stats,
1903 };
1904 
1905 static struct rpc_xprt_ops xs_tcp_ops = {
1906 	.reserve_xprt		= xprt_reserve_xprt,
1907 	.release_xprt		= xs_tcp_release_xprt,
1908 	.rpcbind		= rpcb_getport_async,
1909 	.set_port		= xs_set_port,
1910 	.connect		= xs_tcp_connect,
1911 	.buf_alloc		= rpc_malloc,
1912 	.buf_free		= rpc_free,
1913 	.send_request		= xs_tcp_send_request,
1914 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
1915 	.close			= xs_tcp_shutdown,
1916 	.destroy		= xs_destroy,
1917 	.print_stats		= xs_tcp_print_stats,
1918 };
1919 
1920 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
1921 				      unsigned int slot_table_size)
1922 {
1923 	struct rpc_xprt *xprt;
1924 	struct sock_xprt *new;
1925 
1926 	if (args->addrlen > sizeof(xprt->addr)) {
1927 		dprintk("RPC:       xs_setup_xprt: address too large\n");
1928 		return ERR_PTR(-EBADF);
1929 	}
1930 
1931 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1932 	if (new == NULL) {
1933 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
1934 				"rpc_xprt\n");
1935 		return ERR_PTR(-ENOMEM);
1936 	}
1937 	xprt = &new->xprt;
1938 
1939 	xprt->max_reqs = slot_table_size;
1940 	xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
1941 	if (xprt->slot == NULL) {
1942 		kfree(xprt);
1943 		dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
1944 				"table\n");
1945 		return ERR_PTR(-ENOMEM);
1946 	}
1947 
1948 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
1949 	xprt->addrlen = args->addrlen;
1950 	if (args->srcaddr)
1951 		memcpy(&new->addr, args->srcaddr, args->addrlen);
1952 
1953 	return xprt;
1954 }
1955 
1956 static const struct rpc_timeout xs_udp_default_timeout = {
1957 	.to_initval = 5 * HZ,
1958 	.to_maxval = 30 * HZ,
1959 	.to_increment = 5 * HZ,
1960 	.to_retries = 5,
1961 };
1962 
1963 /**
1964  * xs_setup_udp - Set up transport to use a UDP socket
1965  * @args: rpc transport creation arguments
1966  *
1967  */
1968 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
1969 {
1970 	struct sockaddr *addr = args->dstaddr;
1971 	struct rpc_xprt *xprt;
1972 	struct sock_xprt *transport;
1973 
1974 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
1975 	if (IS_ERR(xprt))
1976 		return xprt;
1977 	transport = container_of(xprt, struct sock_xprt, xprt);
1978 
1979 	xprt->prot = IPPROTO_UDP;
1980 	xprt->tsh_size = 0;
1981 	/* XXX: header size can vary due to auth type, IPv6, etc. */
1982 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1983 
1984 	xprt->bind_timeout = XS_BIND_TO;
1985 	xprt->connect_timeout = XS_UDP_CONN_TO;
1986 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
1987 	xprt->idle_timeout = XS_IDLE_DISC_TO;
1988 
1989 	xprt->ops = &xs_udp_ops;
1990 
1991 	xprt->timeout = &xs_udp_default_timeout;
1992 
1993 	switch (addr->sa_family) {
1994 	case AF_INET:
1995 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
1996 			xprt_set_bound(xprt);
1997 
1998 		INIT_DELAYED_WORK(&transport->connect_worker,
1999 					xs_udp_connect_worker4);
2000 		xs_format_ipv4_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2001 		break;
2002 	case AF_INET6:
2003 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2004 			xprt_set_bound(xprt);
2005 
2006 		INIT_DELAYED_WORK(&transport->connect_worker,
2007 					xs_udp_connect_worker6);
2008 		xs_format_ipv6_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2009 		break;
2010 	default:
2011 		kfree(xprt);
2012 		return ERR_PTR(-EAFNOSUPPORT);
2013 	}
2014 
2015 	dprintk("RPC:       set up transport to address %s\n",
2016 			xprt->address_strings[RPC_DISPLAY_ALL]);
2017 
2018 	if (try_module_get(THIS_MODULE))
2019 		return xprt;
2020 
2021 	kfree(xprt->slot);
2022 	kfree(xprt);
2023 	return ERR_PTR(-EINVAL);
2024 }
2025 
2026 static const struct rpc_timeout xs_tcp_default_timeout = {
2027 	.to_initval = 60 * HZ,
2028 	.to_maxval = 60 * HZ,
2029 	.to_retries = 2,
2030 };
2031 
2032 /**
2033  * xs_setup_tcp - Set up transport to use a TCP socket
2034  * @args: rpc transport creation arguments
2035  *
2036  */
2037 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2038 {
2039 	struct sockaddr *addr = args->dstaddr;
2040 	struct rpc_xprt *xprt;
2041 	struct sock_xprt *transport;
2042 
2043 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2044 	if (IS_ERR(xprt))
2045 		return xprt;
2046 	transport = container_of(xprt, struct sock_xprt, xprt);
2047 
2048 	xprt->prot = IPPROTO_TCP;
2049 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2050 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2051 
2052 	xprt->bind_timeout = XS_BIND_TO;
2053 	xprt->connect_timeout = XS_TCP_CONN_TO;
2054 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2055 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2056 
2057 	xprt->ops = &xs_tcp_ops;
2058 	xprt->timeout = &xs_tcp_default_timeout;
2059 
2060 	switch (addr->sa_family) {
2061 	case AF_INET:
2062 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2063 			xprt_set_bound(xprt);
2064 
2065 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker4);
2066 		xs_format_ipv4_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2067 		break;
2068 	case AF_INET6:
2069 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2070 			xprt_set_bound(xprt);
2071 
2072 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker6);
2073 		xs_format_ipv6_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2074 		break;
2075 	default:
2076 		kfree(xprt);
2077 		return ERR_PTR(-EAFNOSUPPORT);
2078 	}
2079 
2080 	dprintk("RPC:       set up transport to address %s\n",
2081 			xprt->address_strings[RPC_DISPLAY_ALL]);
2082 
2083 	if (try_module_get(THIS_MODULE))
2084 		return xprt;
2085 
2086 	kfree(xprt->slot);
2087 	kfree(xprt);
2088 	return ERR_PTR(-EINVAL);
2089 }
2090 
2091 static struct xprt_class	xs_udp_transport = {
2092 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2093 	.name		= "udp",
2094 	.owner		= THIS_MODULE,
2095 	.ident		= IPPROTO_UDP,
2096 	.setup		= xs_setup_udp,
2097 };
2098 
2099 static struct xprt_class	xs_tcp_transport = {
2100 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2101 	.name		= "tcp",
2102 	.owner		= THIS_MODULE,
2103 	.ident		= IPPROTO_TCP,
2104 	.setup		= xs_setup_tcp,
2105 };
2106 
2107 /**
2108  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2109  *
2110  */
2111 int init_socket_xprt(void)
2112 {
2113 #ifdef RPC_DEBUG
2114 	if (!sunrpc_table_header)
2115 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2116 #endif
2117 
2118 	xprt_register_transport(&xs_udp_transport);
2119 	xprt_register_transport(&xs_tcp_transport);
2120 
2121 	return 0;
2122 }
2123 
2124 /**
2125  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2126  *
2127  */
2128 void cleanup_socket_xprt(void)
2129 {
2130 #ifdef RPC_DEBUG
2131 	if (sunrpc_table_header) {
2132 		unregister_sysctl_table(sunrpc_table_header);
2133 		sunrpc_table_header = NULL;
2134 	}
2135 #endif
2136 
2137 	xprt_unregister_transport(&xs_udp_transport);
2138 	xprt_unregister_transport(&xs_tcp_transport);
2139 }
2140