xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision f42b3800)
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 Software <alan@redhat.com>
7  * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
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  * How many times to try sending a request on a socket before waiting
140  * for the socket buffer to clear.
141  */
142 #define XS_SENDMSG_RETRY	(10U)
143 
144 /*
145  * Time out for an RPC UDP socket connect.  UDP socket connects are
146  * synchronous, but we set a timeout anyway in case of resource
147  * exhaustion on the local host.
148  */
149 #define XS_UDP_CONN_TO		(5U * HZ)
150 
151 /*
152  * Wait duration for an RPC TCP connection to be established.  Solaris
153  * NFS over TCP uses 60 seconds, for example, which is in line with how
154  * long a server takes to reboot.
155  */
156 #define XS_TCP_CONN_TO		(60U * HZ)
157 
158 /*
159  * Wait duration for a reply from the RPC portmapper.
160  */
161 #define XS_BIND_TO		(60U * HZ)
162 
163 /*
164  * Delay if a UDP socket connect error occurs.  This is most likely some
165  * kind of resource problem on the local host.
166  */
167 #define XS_UDP_REEST_TO		(2U * HZ)
168 
169 /*
170  * The reestablish timeout allows clients to delay for a bit before attempting
171  * to reconnect to a server that just dropped our connection.
172  *
173  * We implement an exponential backoff when trying to reestablish a TCP
174  * transport connection with the server.  Some servers like to drop a TCP
175  * connection when they are overworked, so we start with a short timeout and
176  * increase over time if the server is down or not responding.
177  */
178 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
179 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
180 
181 /*
182  * TCP idle timeout; client drops the transport socket if it is idle
183  * for this long.  Note that we also timeout UDP sockets to prevent
184  * holding port numbers when there is no RPC traffic.
185  */
186 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
187 
188 #ifdef RPC_DEBUG
189 # undef  RPC_DEBUG_DATA
190 # define RPCDBG_FACILITY	RPCDBG_TRANS
191 #endif
192 
193 #ifdef RPC_DEBUG_DATA
194 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
195 {
196 	u8 *buf = (u8 *) packet;
197 	int j;
198 
199 	dprintk("RPC:       %s\n", msg);
200 	for (j = 0; j < count && j < 128; j += 4) {
201 		if (!(j & 31)) {
202 			if (j)
203 				dprintk("\n");
204 			dprintk("0x%04x ", j);
205 		}
206 		dprintk("%02x%02x%02x%02x ",
207 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
208 	}
209 	dprintk("\n");
210 }
211 #else
212 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
213 {
214 	/* NOP */
215 }
216 #endif
217 
218 struct sock_xprt {
219 	struct rpc_xprt		xprt;
220 
221 	/*
222 	 * Network layer
223 	 */
224 	struct socket *		sock;
225 	struct sock *		inet;
226 
227 	/*
228 	 * State of TCP reply receive
229 	 */
230 	__be32			tcp_fraghdr,
231 				tcp_xid;
232 
233 	u32			tcp_offset,
234 				tcp_reclen;
235 
236 	unsigned long		tcp_copied,
237 				tcp_flags;
238 
239 	/*
240 	 * Connection of transports
241 	 */
242 	struct delayed_work	connect_worker;
243 	struct sockaddr_storage	addr;
244 	unsigned short		port;
245 
246 	/*
247 	 * UDP socket buffer size parameters
248 	 */
249 	size_t			rcvsize,
250 				sndsize;
251 
252 	/*
253 	 * Saved socket callback addresses
254 	 */
255 	void			(*old_data_ready)(struct sock *, int);
256 	void			(*old_state_change)(struct sock *);
257 	void			(*old_write_space)(struct sock *);
258 };
259 
260 /*
261  * TCP receive state flags
262  */
263 #define TCP_RCV_LAST_FRAG	(1UL << 0)
264 #define TCP_RCV_COPY_FRAGHDR	(1UL << 1)
265 #define TCP_RCV_COPY_XID	(1UL << 2)
266 #define TCP_RCV_COPY_DATA	(1UL << 3)
267 
268 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
269 {
270 	return (struct sockaddr *) &xprt->addr;
271 }
272 
273 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
274 {
275 	return (struct sockaddr_in *) &xprt->addr;
276 }
277 
278 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
279 {
280 	return (struct sockaddr_in6 *) &xprt->addr;
281 }
282 
283 static void xs_format_ipv4_peer_addresses(struct rpc_xprt *xprt,
284 					  const char *protocol,
285 					  const char *netid)
286 {
287 	struct sockaddr_in *addr = xs_addr_in(xprt);
288 	char *buf;
289 
290 	buf = kzalloc(20, GFP_KERNEL);
291 	if (buf) {
292 		snprintf(buf, 20, NIPQUAD_FMT,
293 				NIPQUAD(addr->sin_addr.s_addr));
294 	}
295 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
296 
297 	buf = kzalloc(8, GFP_KERNEL);
298 	if (buf) {
299 		snprintf(buf, 8, "%u",
300 				ntohs(addr->sin_port));
301 	}
302 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
303 
304 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
305 
306 	buf = kzalloc(48, GFP_KERNEL);
307 	if (buf) {
308 		snprintf(buf, 48, "addr="NIPQUAD_FMT" port=%u proto=%s",
309 			NIPQUAD(addr->sin_addr.s_addr),
310 			ntohs(addr->sin_port),
311 			protocol);
312 	}
313 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
314 
315 	buf = kzalloc(10, GFP_KERNEL);
316 	if (buf) {
317 		snprintf(buf, 10, "%02x%02x%02x%02x",
318 				NIPQUAD(addr->sin_addr.s_addr));
319 	}
320 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
321 
322 	buf = kzalloc(8, GFP_KERNEL);
323 	if (buf) {
324 		snprintf(buf, 8, "%4hx",
325 				ntohs(addr->sin_port));
326 	}
327 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
328 
329 	buf = kzalloc(30, GFP_KERNEL);
330 	if (buf) {
331 		snprintf(buf, 30, NIPQUAD_FMT".%u.%u",
332 				NIPQUAD(addr->sin_addr.s_addr),
333 				ntohs(addr->sin_port) >> 8,
334 				ntohs(addr->sin_port) & 0xff);
335 	}
336 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
337 
338 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
339 }
340 
341 static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt,
342 					  const char *protocol,
343 					  const char *netid)
344 {
345 	struct sockaddr_in6 *addr = xs_addr_in6(xprt);
346 	char *buf;
347 
348 	buf = kzalloc(40, GFP_KERNEL);
349 	if (buf) {
350 		snprintf(buf, 40, NIP6_FMT,
351 				NIP6(addr->sin6_addr));
352 	}
353 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
354 
355 	buf = kzalloc(8, GFP_KERNEL);
356 	if (buf) {
357 		snprintf(buf, 8, "%u",
358 				ntohs(addr->sin6_port));
359 	}
360 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
361 
362 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
363 
364 	buf = kzalloc(64, GFP_KERNEL);
365 	if (buf) {
366 		snprintf(buf, 64, "addr="NIP6_FMT" port=%u proto=%s",
367 				NIP6(addr->sin6_addr),
368 				ntohs(addr->sin6_port),
369 				protocol);
370 	}
371 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
372 
373 	buf = kzalloc(36, GFP_KERNEL);
374 	if (buf) {
375 		snprintf(buf, 36, NIP6_SEQFMT,
376 				NIP6(addr->sin6_addr));
377 	}
378 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
379 
380 	buf = kzalloc(8, GFP_KERNEL);
381 	if (buf) {
382 		snprintf(buf, 8, "%4hx",
383 				ntohs(addr->sin6_port));
384 	}
385 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
386 
387 	buf = kzalloc(50, GFP_KERNEL);
388 	if (buf) {
389 		snprintf(buf, 50, NIP6_FMT".%u.%u",
390 				NIP6(addr->sin6_addr),
391 				ntohs(addr->sin6_port) >> 8,
392 				ntohs(addr->sin6_port) & 0xff);
393 	}
394 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
395 
396 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
397 }
398 
399 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
400 {
401 	unsigned int i;
402 
403 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
404 		switch (i) {
405 		case RPC_DISPLAY_PROTO:
406 		case RPC_DISPLAY_NETID:
407 			continue;
408 		default:
409 			kfree(xprt->address_strings[i]);
410 		}
411 }
412 
413 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
414 
415 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
416 {
417 	struct msghdr msg = {
418 		.msg_name	= addr,
419 		.msg_namelen	= addrlen,
420 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
421 	};
422 	struct kvec iov = {
423 		.iov_base	= vec->iov_base + base,
424 		.iov_len	= vec->iov_len - base,
425 	};
426 
427 	if (iov.iov_len != 0)
428 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
429 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
430 }
431 
432 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
433 {
434 	struct page **ppage;
435 	unsigned int remainder;
436 	int err, sent = 0;
437 
438 	remainder = xdr->page_len - base;
439 	base += xdr->page_base;
440 	ppage = xdr->pages + (base >> PAGE_SHIFT);
441 	base &= ~PAGE_MASK;
442 	for(;;) {
443 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
444 		int flags = XS_SENDMSG_FLAGS;
445 
446 		remainder -= len;
447 		if (remainder != 0 || more)
448 			flags |= MSG_MORE;
449 		err = sock->ops->sendpage(sock, *ppage, base, len, flags);
450 		if (remainder == 0 || err != len)
451 			break;
452 		sent += err;
453 		ppage++;
454 		base = 0;
455 	}
456 	if (sent == 0)
457 		return err;
458 	if (err > 0)
459 		sent += err;
460 	return sent;
461 }
462 
463 /**
464  * xs_sendpages - write pages directly to a socket
465  * @sock: socket to send on
466  * @addr: UDP only -- address of destination
467  * @addrlen: UDP only -- length of destination address
468  * @xdr: buffer containing this request
469  * @base: starting position in the buffer
470  *
471  */
472 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
473 {
474 	unsigned int remainder = xdr->len - base;
475 	int err, sent = 0;
476 
477 	if (unlikely(!sock))
478 		return -ENOTCONN;
479 
480 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
481 	if (base != 0) {
482 		addr = NULL;
483 		addrlen = 0;
484 	}
485 
486 	if (base < xdr->head[0].iov_len || addr != NULL) {
487 		unsigned int len = xdr->head[0].iov_len - base;
488 		remainder -= len;
489 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
490 		if (remainder == 0 || err != len)
491 			goto out;
492 		sent += err;
493 		base = 0;
494 	} else
495 		base -= xdr->head[0].iov_len;
496 
497 	if (base < xdr->page_len) {
498 		unsigned int len = xdr->page_len - base;
499 		remainder -= len;
500 		err = xs_send_pagedata(sock, xdr, base, remainder != 0);
501 		if (remainder == 0 || err != len)
502 			goto out;
503 		sent += err;
504 		base = 0;
505 	} else
506 		base -= xdr->page_len;
507 
508 	if (base >= xdr->tail[0].iov_len)
509 		return sent;
510 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
511 out:
512 	if (sent == 0)
513 		return err;
514 	if (err > 0)
515 		sent += err;
516 	return sent;
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 	if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
535 		/* Protect against races with write_space */
536 		spin_lock_bh(&xprt->transport_lock);
537 
538 		/* Don't race with disconnect */
539 		if (!xprt_connected(xprt))
540 			task->tk_status = -ENOTCONN;
541 		else if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
542 			xprt_wait_for_buffer_space(task);
543 
544 		spin_unlock_bh(&xprt->transport_lock);
545 	} else
546 		/* Keep holding the socket if it is blocked */
547 		rpc_delay(task, HZ>>4);
548 }
549 
550 /**
551  * xs_udp_send_request - write an RPC request to a UDP socket
552  * @task: address of RPC task that manages the state of an RPC request
553  *
554  * Return values:
555  *        0:	The request has been sent
556  *   EAGAIN:	The socket was blocked, please call again later to
557  *		complete the request
558  * ENOTCONN:	Caller needs to invoke connect logic then call again
559  *    other:	Some other error occured, the request was not sent
560  */
561 static int xs_udp_send_request(struct rpc_task *task)
562 {
563 	struct rpc_rqst *req = task->tk_rqstp;
564 	struct rpc_xprt *xprt = req->rq_xprt;
565 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
566 	struct xdr_buf *xdr = &req->rq_snd_buf;
567 	int status;
568 
569 	xs_pktdump("packet data:",
570 				req->rq_svec->iov_base,
571 				req->rq_svec->iov_len);
572 
573 	req->rq_xtime = jiffies;
574 	status = xs_sendpages(transport->sock,
575 			      xs_addr(xprt),
576 			      xprt->addrlen, xdr,
577 			      req->rq_bytes_sent);
578 
579 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
580 			xdr->len - req->rq_bytes_sent, status);
581 
582 	if (status >= 0) {
583 		task->tk_bytes_sent += status;
584 		if (status >= req->rq_slen)
585 			return 0;
586 		/* Still some bytes left; set up for a retry later. */
587 		status = -EAGAIN;
588 	}
589 
590 	switch (status) {
591 	case -ENETUNREACH:
592 	case -EPIPE:
593 	case -ECONNREFUSED:
594 		/* When the server has died, an ICMP port unreachable message
595 		 * prompts ECONNREFUSED. */
596 		break;
597 	case -EAGAIN:
598 		xs_nospace(task);
599 		break;
600 	default:
601 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
602 			-status);
603 		break;
604 	}
605 
606 	return status;
607 }
608 
609 /**
610  * xs_tcp_shutdown - gracefully shut down a TCP socket
611  * @xprt: transport
612  *
613  * Initiates a graceful shutdown of the TCP socket by calling the
614  * equivalent of shutdown(SHUT_WR);
615  */
616 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
617 {
618 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
619 	struct socket *sock = transport->sock;
620 
621 	if (sock != NULL)
622 		kernel_sock_shutdown(sock, SHUT_WR);
623 }
624 
625 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
626 {
627 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
628 	rpc_fraghdr *base = buf->head[0].iov_base;
629 	*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
630 }
631 
632 /**
633  * xs_tcp_send_request - write an RPC request to a TCP socket
634  * @task: address of RPC task that manages the state of an RPC request
635  *
636  * Return values:
637  *        0:	The request has been sent
638  *   EAGAIN:	The socket was blocked, please call again later to
639  *		complete the request
640  * ENOTCONN:	Caller needs to invoke connect logic then call again
641  *    other:	Some other error occured, the request was not sent
642  *
643  * XXX: In the case of soft timeouts, should we eventually give up
644  *	if sendmsg is not able to make progress?
645  */
646 static int xs_tcp_send_request(struct rpc_task *task)
647 {
648 	struct rpc_rqst *req = task->tk_rqstp;
649 	struct rpc_xprt *xprt = req->rq_xprt;
650 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
651 	struct xdr_buf *xdr = &req->rq_snd_buf;
652 	int status;
653 	unsigned int retry = 0;
654 
655 	xs_encode_tcp_record_marker(&req->rq_snd_buf);
656 
657 	xs_pktdump("packet data:",
658 				req->rq_svec->iov_base,
659 				req->rq_svec->iov_len);
660 
661 	/* Continue transmitting the packet/record. We must be careful
662 	 * to cope with writespace callbacks arriving _after_ we have
663 	 * called sendmsg(). */
664 	while (1) {
665 		req->rq_xtime = jiffies;
666 		status = xs_sendpages(transport->sock,
667 					NULL, 0, xdr, req->rq_bytes_sent);
668 
669 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
670 				xdr->len - req->rq_bytes_sent, status);
671 
672 		if (unlikely(status < 0))
673 			break;
674 
675 		/* If we've sent the entire packet, immediately
676 		 * reset the count of bytes sent. */
677 		req->rq_bytes_sent += status;
678 		task->tk_bytes_sent += status;
679 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
680 			req->rq_bytes_sent = 0;
681 			return 0;
682 		}
683 
684 		status = -EAGAIN;
685 		if (retry++ > XS_SENDMSG_RETRY)
686 			break;
687 	}
688 
689 	switch (status) {
690 	case -EAGAIN:
691 		xs_nospace(task);
692 		break;
693 	case -ECONNREFUSED:
694 	case -ECONNRESET:
695 	case -ENOTCONN:
696 	case -EPIPE:
697 		status = -ENOTCONN;
698 		break;
699 	default:
700 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
701 			-status);
702 		xs_tcp_shutdown(xprt);
703 		break;
704 	}
705 
706 	return status;
707 }
708 
709 /**
710  * xs_tcp_release_xprt - clean up after a tcp transmission
711  * @xprt: transport
712  * @task: rpc task
713  *
714  * This cleans up if an error causes us to abort the transmission of a request.
715  * In this case, the socket may need to be reset in order to avoid confusing
716  * the server.
717  */
718 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
719 {
720 	struct rpc_rqst *req;
721 
722 	if (task != xprt->snd_task)
723 		return;
724 	if (task == NULL)
725 		goto out_release;
726 	req = task->tk_rqstp;
727 	if (req->rq_bytes_sent == 0)
728 		goto out_release;
729 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
730 		goto out_release;
731 	set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
732 out_release:
733 	xprt_release_xprt(xprt, task);
734 }
735 
736 /**
737  * xs_close - close a socket
738  * @xprt: transport
739  *
740  * This is used when all requests are complete; ie, no DRC state remains
741  * on the server we want to save.
742  */
743 static void xs_close(struct rpc_xprt *xprt)
744 {
745 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
746 	struct socket *sock = transport->sock;
747 	struct sock *sk = transport->inet;
748 
749 	if (!sk)
750 		goto clear_close_wait;
751 
752 	dprintk("RPC:       xs_close xprt %p\n", xprt);
753 
754 	write_lock_bh(&sk->sk_callback_lock);
755 	transport->inet = NULL;
756 	transport->sock = NULL;
757 
758 	sk->sk_user_data = NULL;
759 	sk->sk_data_ready = transport->old_data_ready;
760 	sk->sk_state_change = transport->old_state_change;
761 	sk->sk_write_space = transport->old_write_space;
762 	write_unlock_bh(&sk->sk_callback_lock);
763 
764 	sk->sk_no_check = 0;
765 
766 	sock_release(sock);
767 clear_close_wait:
768 	smp_mb__before_clear_bit();
769 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
770 	clear_bit(XPRT_CLOSING, &xprt->state);
771 	smp_mb__after_clear_bit();
772 	xprt_disconnect_done(xprt);
773 }
774 
775 /**
776  * xs_destroy - prepare to shutdown a transport
777  * @xprt: doomed transport
778  *
779  */
780 static void xs_destroy(struct rpc_xprt *xprt)
781 {
782 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
783 
784 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
785 
786 	cancel_rearming_delayed_work(&transport->connect_worker);
787 
788 	xs_close(xprt);
789 	xs_free_peer_addresses(xprt);
790 	kfree(xprt->slot);
791 	kfree(xprt);
792 	module_put(THIS_MODULE);
793 }
794 
795 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
796 {
797 	return (struct rpc_xprt *) sk->sk_user_data;
798 }
799 
800 /**
801  * xs_udp_data_ready - "data ready" callback for UDP sockets
802  * @sk: socket with data to read
803  * @len: how much data to read
804  *
805  */
806 static void xs_udp_data_ready(struct sock *sk, int len)
807 {
808 	struct rpc_task *task;
809 	struct rpc_xprt *xprt;
810 	struct rpc_rqst *rovr;
811 	struct sk_buff *skb;
812 	int err, repsize, copied;
813 	u32 _xid;
814 	__be32 *xp;
815 
816 	read_lock(&sk->sk_callback_lock);
817 	dprintk("RPC:       xs_udp_data_ready...\n");
818 	if (!(xprt = xprt_from_sock(sk)))
819 		goto out;
820 
821 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
822 		goto out;
823 
824 	if (xprt->shutdown)
825 		goto dropit;
826 
827 	repsize = skb->len - sizeof(struct udphdr);
828 	if (repsize < 4) {
829 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
830 		goto dropit;
831 	}
832 
833 	/* Copy the XID from the skb... */
834 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
835 				sizeof(_xid), &_xid);
836 	if (xp == NULL)
837 		goto dropit;
838 
839 	/* Look up and lock the request corresponding to the given XID */
840 	spin_lock(&xprt->transport_lock);
841 	rovr = xprt_lookup_rqst(xprt, *xp);
842 	if (!rovr)
843 		goto out_unlock;
844 	task = rovr->rq_task;
845 
846 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
847 		copied = repsize;
848 
849 	/* Suck it into the iovec, verify checksum if not done by hw. */
850 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
851 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
852 		goto out_unlock;
853 	}
854 
855 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
856 
857 	/* Something worked... */
858 	dst_confirm(skb->dst);
859 
860 	xprt_adjust_cwnd(task, copied);
861 	xprt_update_rtt(task);
862 	xprt_complete_rqst(task, copied);
863 
864  out_unlock:
865 	spin_unlock(&xprt->transport_lock);
866  dropit:
867 	skb_free_datagram(sk, skb);
868  out:
869 	read_unlock(&sk->sk_callback_lock);
870 }
871 
872 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
873 {
874 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
875 	size_t len, used;
876 	char *p;
877 
878 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
879 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
880 	used = xdr_skb_read_bits(desc, p, len);
881 	transport->tcp_offset += used;
882 	if (used != len)
883 		return;
884 
885 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
886 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
887 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
888 	else
889 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
890 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
891 
892 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
893 	transport->tcp_offset = 0;
894 
895 	/* Sanity check of the record length */
896 	if (unlikely(transport->tcp_reclen < 4)) {
897 		dprintk("RPC:       invalid TCP record fragment length\n");
898 		xprt_force_disconnect(xprt);
899 		return;
900 	}
901 	dprintk("RPC:       reading TCP record fragment of length %d\n",
902 			transport->tcp_reclen);
903 }
904 
905 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
906 {
907 	if (transport->tcp_offset == transport->tcp_reclen) {
908 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
909 		transport->tcp_offset = 0;
910 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
911 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
912 			transport->tcp_flags |= TCP_RCV_COPY_XID;
913 			transport->tcp_copied = 0;
914 		}
915 	}
916 }
917 
918 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
919 {
920 	size_t len, used;
921 	char *p;
922 
923 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
924 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
925 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
926 	used = xdr_skb_read_bits(desc, p, len);
927 	transport->tcp_offset += used;
928 	if (used != len)
929 		return;
930 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
931 	transport->tcp_flags |= TCP_RCV_COPY_DATA;
932 	transport->tcp_copied = 4;
933 	dprintk("RPC:       reading reply for XID %08x\n",
934 			ntohl(transport->tcp_xid));
935 	xs_tcp_check_fraghdr(transport);
936 }
937 
938 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
939 {
940 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
941 	struct rpc_rqst *req;
942 	struct xdr_buf *rcvbuf;
943 	size_t len;
944 	ssize_t r;
945 
946 	/* Find and lock the request corresponding to this xid */
947 	spin_lock(&xprt->transport_lock);
948 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
949 	if (!req) {
950 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
951 		dprintk("RPC:       XID %08x request not found!\n",
952 				ntohl(transport->tcp_xid));
953 		spin_unlock(&xprt->transport_lock);
954 		return;
955 	}
956 
957 	rcvbuf = &req->rq_private_buf;
958 	len = desc->count;
959 	if (len > transport->tcp_reclen - transport->tcp_offset) {
960 		struct xdr_skb_reader my_desc;
961 
962 		len = transport->tcp_reclen - transport->tcp_offset;
963 		memcpy(&my_desc, desc, sizeof(my_desc));
964 		my_desc.count = len;
965 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
966 					  &my_desc, xdr_skb_read_bits);
967 		desc->count -= r;
968 		desc->offset += r;
969 	} else
970 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
971 					  desc, xdr_skb_read_bits);
972 
973 	if (r > 0) {
974 		transport->tcp_copied += r;
975 		transport->tcp_offset += r;
976 	}
977 	if (r != len) {
978 		/* Error when copying to the receive buffer,
979 		 * usually because we weren't able to allocate
980 		 * additional buffer pages. All we can do now
981 		 * is turn off TCP_RCV_COPY_DATA, so the request
982 		 * will not receive any additional updates,
983 		 * and time out.
984 		 * Any remaining data from this record will
985 		 * be discarded.
986 		 */
987 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
988 		dprintk("RPC:       XID %08x truncated request\n",
989 				ntohl(transport->tcp_xid));
990 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
991 				"tcp_offset = %u, tcp_reclen = %u\n",
992 				xprt, transport->tcp_copied,
993 				transport->tcp_offset, transport->tcp_reclen);
994 		goto out;
995 	}
996 
997 	dprintk("RPC:       XID %08x read %Zd bytes\n",
998 			ntohl(transport->tcp_xid), r);
999 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1000 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1001 			transport->tcp_offset, transport->tcp_reclen);
1002 
1003 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1004 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1005 	else if (transport->tcp_offset == transport->tcp_reclen) {
1006 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1007 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1008 	}
1009 
1010 out:
1011 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1012 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1013 	spin_unlock(&xprt->transport_lock);
1014 	xs_tcp_check_fraghdr(transport);
1015 }
1016 
1017 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1018 {
1019 	size_t len;
1020 
1021 	len = transport->tcp_reclen - transport->tcp_offset;
1022 	if (len > desc->count)
1023 		len = desc->count;
1024 	desc->count -= len;
1025 	desc->offset += len;
1026 	transport->tcp_offset += len;
1027 	dprintk("RPC:       discarded %Zu bytes\n", len);
1028 	xs_tcp_check_fraghdr(transport);
1029 }
1030 
1031 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1032 {
1033 	struct rpc_xprt *xprt = rd_desc->arg.data;
1034 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1035 	struct xdr_skb_reader desc = {
1036 		.skb	= skb,
1037 		.offset	= offset,
1038 		.count	= len,
1039 	};
1040 
1041 	dprintk("RPC:       xs_tcp_data_recv started\n");
1042 	do {
1043 		/* Read in a new fragment marker if necessary */
1044 		/* Can we ever really expect to get completely empty fragments? */
1045 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1046 			xs_tcp_read_fraghdr(xprt, &desc);
1047 			continue;
1048 		}
1049 		/* Read in the xid if necessary */
1050 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1051 			xs_tcp_read_xid(transport, &desc);
1052 			continue;
1053 		}
1054 		/* Read in the request data */
1055 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1056 			xs_tcp_read_request(xprt, &desc);
1057 			continue;
1058 		}
1059 		/* Skip over any trailing bytes on short reads */
1060 		xs_tcp_read_discard(transport, &desc);
1061 	} while (desc.count);
1062 	dprintk("RPC:       xs_tcp_data_recv done\n");
1063 	return len - desc.count;
1064 }
1065 
1066 /**
1067  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1068  * @sk: socket with data to read
1069  * @bytes: how much data to read
1070  *
1071  */
1072 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1073 {
1074 	struct rpc_xprt *xprt;
1075 	read_descriptor_t rd_desc;
1076 
1077 	dprintk("RPC:       xs_tcp_data_ready...\n");
1078 
1079 	read_lock(&sk->sk_callback_lock);
1080 	if (!(xprt = xprt_from_sock(sk)))
1081 		goto out;
1082 	if (xprt->shutdown)
1083 		goto out;
1084 
1085 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1086 	rd_desc.arg.data = xprt;
1087 	rd_desc.count = 65536;
1088 	tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1089 out:
1090 	read_unlock(&sk->sk_callback_lock);
1091 }
1092 
1093 /**
1094  * xs_tcp_state_change - callback to handle TCP socket state changes
1095  * @sk: socket whose state has changed
1096  *
1097  */
1098 static void xs_tcp_state_change(struct sock *sk)
1099 {
1100 	struct rpc_xprt *xprt;
1101 
1102 	read_lock(&sk->sk_callback_lock);
1103 	if (!(xprt = xprt_from_sock(sk)))
1104 		goto out;
1105 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1106 	dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1107 			sk->sk_state, xprt_connected(xprt),
1108 			sock_flag(sk, SOCK_DEAD),
1109 			sock_flag(sk, SOCK_ZAPPED));
1110 
1111 	switch (sk->sk_state) {
1112 	case TCP_ESTABLISHED:
1113 		spin_lock_bh(&xprt->transport_lock);
1114 		if (!xprt_test_and_set_connected(xprt)) {
1115 			struct sock_xprt *transport = container_of(xprt,
1116 					struct sock_xprt, xprt);
1117 
1118 			/* Reset TCP record info */
1119 			transport->tcp_offset = 0;
1120 			transport->tcp_reclen = 0;
1121 			transport->tcp_copied = 0;
1122 			transport->tcp_flags =
1123 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1124 
1125 			xprt_wake_pending_tasks(xprt, 0);
1126 		}
1127 		spin_unlock_bh(&xprt->transport_lock);
1128 		break;
1129 	case TCP_FIN_WAIT1:
1130 		/* The client initiated a shutdown of the socket */
1131 		xprt->reestablish_timeout = 0;
1132 		set_bit(XPRT_CLOSING, &xprt->state);
1133 		smp_mb__before_clear_bit();
1134 		clear_bit(XPRT_CONNECTED, &xprt->state);
1135 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1136 		smp_mb__after_clear_bit();
1137 		break;
1138 	case TCP_CLOSE_WAIT:
1139 		/* The server initiated a shutdown of the socket */
1140 		set_bit(XPRT_CLOSING, &xprt->state);
1141 		xprt_force_disconnect(xprt);
1142 	case TCP_SYN_SENT:
1143 	case TCP_CLOSING:
1144 		/*
1145 		 * If the server closed down the connection, make sure that
1146 		 * we back off before reconnecting
1147 		 */
1148 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1149 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1150 		break;
1151 	case TCP_LAST_ACK:
1152 		smp_mb__before_clear_bit();
1153 		clear_bit(XPRT_CONNECTED, &xprt->state);
1154 		smp_mb__after_clear_bit();
1155 		break;
1156 	case TCP_CLOSE:
1157 		smp_mb__before_clear_bit();
1158 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1159 		clear_bit(XPRT_CLOSING, &xprt->state);
1160 		smp_mb__after_clear_bit();
1161 		/* Mark transport as closed and wake up all pending tasks */
1162 		xprt_disconnect_done(xprt);
1163 	}
1164  out:
1165 	read_unlock(&sk->sk_callback_lock);
1166 }
1167 
1168 /**
1169  * xs_udp_write_space - callback invoked when socket buffer space
1170  *                             becomes available
1171  * @sk: socket whose state has changed
1172  *
1173  * Called when more output buffer space is available for this socket.
1174  * We try not to wake our writers until they can make "significant"
1175  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1176  * with a bunch of small requests.
1177  */
1178 static void xs_udp_write_space(struct sock *sk)
1179 {
1180 	read_lock(&sk->sk_callback_lock);
1181 
1182 	/* from net/core/sock.c:sock_def_write_space */
1183 	if (sock_writeable(sk)) {
1184 		struct socket *sock;
1185 		struct rpc_xprt *xprt;
1186 
1187 		if (unlikely(!(sock = sk->sk_socket)))
1188 			goto out;
1189 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1190 			goto out;
1191 		if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
1192 			goto out;
1193 
1194 		xprt_write_space(xprt);
1195 	}
1196 
1197  out:
1198 	read_unlock(&sk->sk_callback_lock);
1199 }
1200 
1201 /**
1202  * xs_tcp_write_space - callback invoked when socket buffer space
1203  *                             becomes available
1204  * @sk: socket whose state has changed
1205  *
1206  * Called when more output buffer space is available for this socket.
1207  * We try not to wake our writers until they can make "significant"
1208  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1209  * with a bunch of small requests.
1210  */
1211 static void xs_tcp_write_space(struct sock *sk)
1212 {
1213 	read_lock(&sk->sk_callback_lock);
1214 
1215 	/* from net/core/stream.c:sk_stream_write_space */
1216 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
1217 		struct socket *sock;
1218 		struct rpc_xprt *xprt;
1219 
1220 		if (unlikely(!(sock = sk->sk_socket)))
1221 			goto out;
1222 		if (unlikely(!(xprt = xprt_from_sock(sk))))
1223 			goto out;
1224 		if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
1225 			goto out;
1226 
1227 		xprt_write_space(xprt);
1228 	}
1229 
1230  out:
1231 	read_unlock(&sk->sk_callback_lock);
1232 }
1233 
1234 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1235 {
1236 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1237 	struct sock *sk = transport->inet;
1238 
1239 	if (transport->rcvsize) {
1240 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1241 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1242 	}
1243 	if (transport->sndsize) {
1244 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1245 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1246 		sk->sk_write_space(sk);
1247 	}
1248 }
1249 
1250 /**
1251  * xs_udp_set_buffer_size - set send and receive limits
1252  * @xprt: generic transport
1253  * @sndsize: requested size of send buffer, in bytes
1254  * @rcvsize: requested size of receive buffer, in bytes
1255  *
1256  * Set socket send and receive buffer size limits.
1257  */
1258 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1259 {
1260 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1261 
1262 	transport->sndsize = 0;
1263 	if (sndsize)
1264 		transport->sndsize = sndsize + 1024;
1265 	transport->rcvsize = 0;
1266 	if (rcvsize)
1267 		transport->rcvsize = rcvsize + 1024;
1268 
1269 	xs_udp_do_set_buffer_size(xprt);
1270 }
1271 
1272 /**
1273  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1274  * @task: task that timed out
1275  *
1276  * Adjust the congestion window after a retransmit timeout has occurred.
1277  */
1278 static void xs_udp_timer(struct rpc_task *task)
1279 {
1280 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1281 }
1282 
1283 static unsigned short xs_get_random_port(void)
1284 {
1285 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1286 	unsigned short rand = (unsigned short) net_random() % range;
1287 	return rand + xprt_min_resvport;
1288 }
1289 
1290 /**
1291  * xs_set_port - reset the port number in the remote endpoint address
1292  * @xprt: generic transport
1293  * @port: new port number
1294  *
1295  */
1296 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1297 {
1298 	struct sockaddr *addr = xs_addr(xprt);
1299 
1300 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1301 
1302 	switch (addr->sa_family) {
1303 	case AF_INET:
1304 		((struct sockaddr_in *)addr)->sin_port = htons(port);
1305 		break;
1306 	case AF_INET6:
1307 		((struct sockaddr_in6 *)addr)->sin6_port = htons(port);
1308 		break;
1309 	default:
1310 		BUG();
1311 	}
1312 }
1313 
1314 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1315 {
1316 	unsigned short port = transport->port;
1317 
1318 	if (port == 0 && transport->xprt.resvport)
1319 		port = xs_get_random_port();
1320 	return port;
1321 }
1322 
1323 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1324 {
1325 	if (transport->port != 0)
1326 		transport->port = 0;
1327 	if (!transport->xprt.resvport)
1328 		return 0;
1329 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1330 		return xprt_max_resvport;
1331 	return --port;
1332 }
1333 
1334 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1335 {
1336 	struct sockaddr_in myaddr = {
1337 		.sin_family = AF_INET,
1338 	};
1339 	struct sockaddr_in *sa;
1340 	int err, nloop = 0;
1341 	unsigned short port = xs_get_srcport(transport, sock);
1342 	unsigned short last;
1343 
1344 	sa = (struct sockaddr_in *)&transport->addr;
1345 	myaddr.sin_addr = sa->sin_addr;
1346 	do {
1347 		myaddr.sin_port = htons(port);
1348 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1349 						sizeof(myaddr));
1350 		if (port == 0)
1351 			break;
1352 		if (err == 0) {
1353 			transport->port = port;
1354 			break;
1355 		}
1356 		last = port;
1357 		port = xs_next_srcport(transport, sock, port);
1358 		if (port > last)
1359 			nloop++;
1360 	} while (err == -EADDRINUSE && nloop != 2);
1361 	dprintk("RPC:       %s "NIPQUAD_FMT":%u: %s (%d)\n",
1362 			__func__, NIPQUAD(myaddr.sin_addr),
1363 			port, err ? "failed" : "ok", err);
1364 	return err;
1365 }
1366 
1367 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1368 {
1369 	struct sockaddr_in6 myaddr = {
1370 		.sin6_family = AF_INET6,
1371 	};
1372 	struct sockaddr_in6 *sa;
1373 	int err, nloop = 0;
1374 	unsigned short port = xs_get_srcport(transport, sock);
1375 	unsigned short last;
1376 
1377 	sa = (struct sockaddr_in6 *)&transport->addr;
1378 	myaddr.sin6_addr = sa->sin6_addr;
1379 	do {
1380 		myaddr.sin6_port = htons(port);
1381 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1382 						sizeof(myaddr));
1383 		if (port == 0)
1384 			break;
1385 		if (err == 0) {
1386 			transport->port = port;
1387 			break;
1388 		}
1389 		last = port;
1390 		port = xs_next_srcport(transport, sock, port);
1391 		if (port > last)
1392 			nloop++;
1393 	} while (err == -EADDRINUSE && nloop != 2);
1394 	dprintk("RPC:       xs_bind6 "NIP6_FMT":%u: %s (%d)\n",
1395 		NIP6(myaddr.sin6_addr), port, err ? "failed" : "ok", err);
1396 	return err;
1397 }
1398 
1399 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1400 static struct lock_class_key xs_key[2];
1401 static struct lock_class_key xs_slock_key[2];
1402 
1403 static inline void xs_reclassify_socket4(struct socket *sock)
1404 {
1405 	struct sock *sk = sock->sk;
1406 
1407 	BUG_ON(sock_owned_by_user(sk));
1408 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1409 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1410 }
1411 
1412 static inline void xs_reclassify_socket6(struct socket *sock)
1413 {
1414 	struct sock *sk = sock->sk;
1415 
1416 	BUG_ON(sock_owned_by_user(sk));
1417 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1418 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1419 }
1420 #else
1421 static inline void xs_reclassify_socket4(struct socket *sock)
1422 {
1423 }
1424 
1425 static inline void xs_reclassify_socket6(struct socket *sock)
1426 {
1427 }
1428 #endif
1429 
1430 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1431 {
1432 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1433 
1434 	if (!transport->inet) {
1435 		struct sock *sk = sock->sk;
1436 
1437 		write_lock_bh(&sk->sk_callback_lock);
1438 
1439 		sk->sk_user_data = xprt;
1440 		transport->old_data_ready = sk->sk_data_ready;
1441 		transport->old_state_change = sk->sk_state_change;
1442 		transport->old_write_space = sk->sk_write_space;
1443 		sk->sk_data_ready = xs_udp_data_ready;
1444 		sk->sk_write_space = xs_udp_write_space;
1445 		sk->sk_no_check = UDP_CSUM_NORCV;
1446 		sk->sk_allocation = GFP_ATOMIC;
1447 
1448 		xprt_set_connected(xprt);
1449 
1450 		/* Reset to new socket */
1451 		transport->sock = sock;
1452 		transport->inet = sk;
1453 
1454 		write_unlock_bh(&sk->sk_callback_lock);
1455 	}
1456 	xs_udp_do_set_buffer_size(xprt);
1457 }
1458 
1459 /**
1460  * xs_udp_connect_worker4 - set up a UDP socket
1461  * @work: RPC transport to connect
1462  *
1463  * Invoked by a work queue tasklet.
1464  */
1465 static void xs_udp_connect_worker4(struct work_struct *work)
1466 {
1467 	struct sock_xprt *transport =
1468 		container_of(work, struct sock_xprt, connect_worker.work);
1469 	struct rpc_xprt *xprt = &transport->xprt;
1470 	struct socket *sock = transport->sock;
1471 	int err, status = -EIO;
1472 
1473 	if (xprt->shutdown || !xprt_bound(xprt))
1474 		goto out;
1475 
1476 	/* Start by resetting any existing state */
1477 	xs_close(xprt);
1478 
1479 	if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1480 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1481 		goto out;
1482 	}
1483 	xs_reclassify_socket4(sock);
1484 
1485 	if (xs_bind4(transport, sock)) {
1486 		sock_release(sock);
1487 		goto out;
1488 	}
1489 
1490 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1491 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1492 
1493 	xs_udp_finish_connecting(xprt, sock);
1494 	status = 0;
1495 out:
1496 	xprt_wake_pending_tasks(xprt, status);
1497 	xprt_clear_connecting(xprt);
1498 }
1499 
1500 /**
1501  * xs_udp_connect_worker6 - set up a UDP socket
1502  * @work: RPC transport to connect
1503  *
1504  * Invoked by a work queue tasklet.
1505  */
1506 static void xs_udp_connect_worker6(struct work_struct *work)
1507 {
1508 	struct sock_xprt *transport =
1509 		container_of(work, struct sock_xprt, connect_worker.work);
1510 	struct rpc_xprt *xprt = &transport->xprt;
1511 	struct socket *sock = transport->sock;
1512 	int err, status = -EIO;
1513 
1514 	if (xprt->shutdown || !xprt_bound(xprt))
1515 		goto out;
1516 
1517 	/* Start by resetting any existing state */
1518 	xs_close(xprt);
1519 
1520 	if ((err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1521 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1522 		goto out;
1523 	}
1524 	xs_reclassify_socket6(sock);
1525 
1526 	if (xs_bind6(transport, sock) < 0) {
1527 		sock_release(sock);
1528 		goto out;
1529 	}
1530 
1531 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1532 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1533 
1534 	xs_udp_finish_connecting(xprt, sock);
1535 	status = 0;
1536 out:
1537 	xprt_wake_pending_tasks(xprt, status);
1538 	xprt_clear_connecting(xprt);
1539 }
1540 
1541 /*
1542  * We need to preserve the port number so the reply cache on the server can
1543  * find our cached RPC replies when we get around to reconnecting.
1544  */
1545 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1546 {
1547 	int result;
1548 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1549 	struct sockaddr any;
1550 
1551 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1552 
1553 	/*
1554 	 * Disconnect the transport socket by doing a connect operation
1555 	 * with AF_UNSPEC.  This should return immediately...
1556 	 */
1557 	memset(&any, 0, sizeof(any));
1558 	any.sa_family = AF_UNSPEC;
1559 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1560 	if (result)
1561 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1562 				result);
1563 }
1564 
1565 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1566 {
1567 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1568 
1569 	if (!transport->inet) {
1570 		struct sock *sk = sock->sk;
1571 
1572 		write_lock_bh(&sk->sk_callback_lock);
1573 
1574 		sk->sk_user_data = xprt;
1575 		transport->old_data_ready = sk->sk_data_ready;
1576 		transport->old_state_change = sk->sk_state_change;
1577 		transport->old_write_space = sk->sk_write_space;
1578 		sk->sk_data_ready = xs_tcp_data_ready;
1579 		sk->sk_state_change = xs_tcp_state_change;
1580 		sk->sk_write_space = xs_tcp_write_space;
1581 		sk->sk_allocation = GFP_ATOMIC;
1582 
1583 		/* socket options */
1584 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1585 		sock_reset_flag(sk, SOCK_LINGER);
1586 		tcp_sk(sk)->linger2 = 0;
1587 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1588 
1589 		xprt_clear_connected(xprt);
1590 
1591 		/* Reset to new socket */
1592 		transport->sock = sock;
1593 		transport->inet = sk;
1594 
1595 		write_unlock_bh(&sk->sk_callback_lock);
1596 	}
1597 
1598 	/* Tell the socket layer to start connecting... */
1599 	xprt->stat.connect_count++;
1600 	xprt->stat.connect_start = jiffies;
1601 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1602 }
1603 
1604 /**
1605  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1606  * @work: RPC transport to connect
1607  *
1608  * Invoked by a work queue tasklet.
1609  */
1610 static void xs_tcp_connect_worker4(struct work_struct *work)
1611 {
1612 	struct sock_xprt *transport =
1613 		container_of(work, struct sock_xprt, connect_worker.work);
1614 	struct rpc_xprt *xprt = &transport->xprt;
1615 	struct socket *sock = transport->sock;
1616 	int err, status = -EIO;
1617 
1618 	if (xprt->shutdown || !xprt_bound(xprt))
1619 		goto out;
1620 
1621 	if (!sock) {
1622 		/* start from scratch */
1623 		if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1624 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1625 			goto out;
1626 		}
1627 		xs_reclassify_socket4(sock);
1628 
1629 		if (xs_bind4(transport, sock) < 0) {
1630 			sock_release(sock);
1631 			goto out;
1632 		}
1633 	} else
1634 		/* "close" the socket, preserving the local port */
1635 		xs_tcp_reuse_connection(xprt);
1636 
1637 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1638 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1639 
1640 	status = xs_tcp_finish_connecting(xprt, sock);
1641 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1642 			xprt, -status, xprt_connected(xprt),
1643 			sock->sk->sk_state);
1644 	if (status < 0) {
1645 		switch (status) {
1646 			case -EINPROGRESS:
1647 			case -EALREADY:
1648 				goto out_clear;
1649 			case -ECONNREFUSED:
1650 			case -ECONNRESET:
1651 				/* retry with existing socket, after a delay */
1652 				break;
1653 			default:
1654 				/* get rid of existing socket, and retry */
1655 				xs_tcp_shutdown(xprt);
1656 		}
1657 	}
1658 out:
1659 	xprt_wake_pending_tasks(xprt, status);
1660 out_clear:
1661 	xprt_clear_connecting(xprt);
1662 }
1663 
1664 /**
1665  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1666  * @work: RPC transport to connect
1667  *
1668  * Invoked by a work queue tasklet.
1669  */
1670 static void xs_tcp_connect_worker6(struct work_struct *work)
1671 {
1672 	struct sock_xprt *transport =
1673 		container_of(work, struct sock_xprt, connect_worker.work);
1674 	struct rpc_xprt *xprt = &transport->xprt;
1675 	struct socket *sock = transport->sock;
1676 	int err, status = -EIO;
1677 
1678 	if (xprt->shutdown || !xprt_bound(xprt))
1679 		goto out;
1680 
1681 	if (!sock) {
1682 		/* start from scratch */
1683 		if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1684 			dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
1685 			goto out;
1686 		}
1687 		xs_reclassify_socket6(sock);
1688 
1689 		if (xs_bind6(transport, sock) < 0) {
1690 			sock_release(sock);
1691 			goto out;
1692 		}
1693 	} else
1694 		/* "close" the socket, preserving the local port */
1695 		xs_tcp_reuse_connection(xprt);
1696 
1697 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1698 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1699 
1700 	status = xs_tcp_finish_connecting(xprt, sock);
1701 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1702 			xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1703 	if (status < 0) {
1704 		switch (status) {
1705 			case -EINPROGRESS:
1706 			case -EALREADY:
1707 				goto out_clear;
1708 			case -ECONNREFUSED:
1709 			case -ECONNRESET:
1710 				/* retry with existing socket, after a delay */
1711 				break;
1712 			default:
1713 				/* get rid of existing socket, and retry */
1714 				xs_tcp_shutdown(xprt);
1715 		}
1716 	}
1717 out:
1718 	xprt_wake_pending_tasks(xprt, status);
1719 out_clear:
1720 	xprt_clear_connecting(xprt);
1721 }
1722 
1723 /**
1724  * xs_connect - connect a socket to a remote endpoint
1725  * @task: address of RPC task that manages state of connect request
1726  *
1727  * TCP: If the remote end dropped the connection, delay reconnecting.
1728  *
1729  * UDP socket connects are synchronous, but we use a work queue anyway
1730  * to guarantee that even unprivileged user processes can set up a
1731  * socket on a privileged port.
1732  *
1733  * If a UDP socket connect fails, the delay behavior here prevents
1734  * retry floods (hard mounts).
1735  */
1736 static void xs_connect(struct rpc_task *task)
1737 {
1738 	struct rpc_xprt *xprt = task->tk_xprt;
1739 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1740 
1741 	if (xprt_test_and_set_connecting(xprt))
1742 		return;
1743 
1744 	if (transport->sock != NULL) {
1745 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
1746 				"seconds\n",
1747 				xprt, xprt->reestablish_timeout / HZ);
1748 		queue_delayed_work(rpciod_workqueue,
1749 				   &transport->connect_worker,
1750 				   xprt->reestablish_timeout);
1751 		xprt->reestablish_timeout <<= 1;
1752 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1753 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1754 	} else {
1755 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
1756 		queue_delayed_work(rpciod_workqueue,
1757 				   &transport->connect_worker, 0);
1758 	}
1759 }
1760 
1761 static void xs_tcp_connect(struct rpc_task *task)
1762 {
1763 	struct rpc_xprt *xprt = task->tk_xprt;
1764 
1765 	/* Initiate graceful shutdown of the socket if not already done */
1766 	if (test_bit(XPRT_CONNECTED, &xprt->state))
1767 		xs_tcp_shutdown(xprt);
1768 	/* Exit if we need to wait for socket shutdown to complete */
1769 	if (test_bit(XPRT_CLOSING, &xprt->state))
1770 		return;
1771 	xs_connect(task);
1772 }
1773 
1774 /**
1775  * xs_udp_print_stats - display UDP socket-specifc stats
1776  * @xprt: rpc_xprt struct containing statistics
1777  * @seq: output file
1778  *
1779  */
1780 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1781 {
1782 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1783 
1784 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1785 			transport->port,
1786 			xprt->stat.bind_count,
1787 			xprt->stat.sends,
1788 			xprt->stat.recvs,
1789 			xprt->stat.bad_xids,
1790 			xprt->stat.req_u,
1791 			xprt->stat.bklog_u);
1792 }
1793 
1794 /**
1795  * xs_tcp_print_stats - display TCP socket-specifc stats
1796  * @xprt: rpc_xprt struct containing statistics
1797  * @seq: output file
1798  *
1799  */
1800 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1801 {
1802 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1803 	long idle_time = 0;
1804 
1805 	if (xprt_connected(xprt))
1806 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
1807 
1808 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1809 			transport->port,
1810 			xprt->stat.bind_count,
1811 			xprt->stat.connect_count,
1812 			xprt->stat.connect_time,
1813 			idle_time,
1814 			xprt->stat.sends,
1815 			xprt->stat.recvs,
1816 			xprt->stat.bad_xids,
1817 			xprt->stat.req_u,
1818 			xprt->stat.bklog_u);
1819 }
1820 
1821 static struct rpc_xprt_ops xs_udp_ops = {
1822 	.set_buffer_size	= xs_udp_set_buffer_size,
1823 	.reserve_xprt		= xprt_reserve_xprt_cong,
1824 	.release_xprt		= xprt_release_xprt_cong,
1825 	.rpcbind		= rpcb_getport_async,
1826 	.set_port		= xs_set_port,
1827 	.connect		= xs_connect,
1828 	.buf_alloc		= rpc_malloc,
1829 	.buf_free		= rpc_free,
1830 	.send_request		= xs_udp_send_request,
1831 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
1832 	.timer			= xs_udp_timer,
1833 	.release_request	= xprt_release_rqst_cong,
1834 	.close			= xs_close,
1835 	.destroy		= xs_destroy,
1836 	.print_stats		= xs_udp_print_stats,
1837 };
1838 
1839 static struct rpc_xprt_ops xs_tcp_ops = {
1840 	.reserve_xprt		= xprt_reserve_xprt,
1841 	.release_xprt		= xs_tcp_release_xprt,
1842 	.rpcbind		= rpcb_getport_async,
1843 	.set_port		= xs_set_port,
1844 	.connect		= xs_tcp_connect,
1845 	.buf_alloc		= rpc_malloc,
1846 	.buf_free		= rpc_free,
1847 	.send_request		= xs_tcp_send_request,
1848 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
1849 	.close			= xs_tcp_shutdown,
1850 	.destroy		= xs_destroy,
1851 	.print_stats		= xs_tcp_print_stats,
1852 };
1853 
1854 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
1855 				      unsigned int slot_table_size)
1856 {
1857 	struct rpc_xprt *xprt;
1858 	struct sock_xprt *new;
1859 
1860 	if (args->addrlen > sizeof(xprt->addr)) {
1861 		dprintk("RPC:       xs_setup_xprt: address too large\n");
1862 		return ERR_PTR(-EBADF);
1863 	}
1864 
1865 	new = kzalloc(sizeof(*new), GFP_KERNEL);
1866 	if (new == NULL) {
1867 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
1868 				"rpc_xprt\n");
1869 		return ERR_PTR(-ENOMEM);
1870 	}
1871 	xprt = &new->xprt;
1872 
1873 	xprt->max_reqs = slot_table_size;
1874 	xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
1875 	if (xprt->slot == NULL) {
1876 		kfree(xprt);
1877 		dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
1878 				"table\n");
1879 		return ERR_PTR(-ENOMEM);
1880 	}
1881 
1882 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
1883 	xprt->addrlen = args->addrlen;
1884 	if (args->srcaddr)
1885 		memcpy(&new->addr, args->srcaddr, args->addrlen);
1886 
1887 	return xprt;
1888 }
1889 
1890 static const struct rpc_timeout xs_udp_default_timeout = {
1891 	.to_initval = 5 * HZ,
1892 	.to_maxval = 30 * HZ,
1893 	.to_increment = 5 * HZ,
1894 	.to_retries = 5,
1895 };
1896 
1897 /**
1898  * xs_setup_udp - Set up transport to use a UDP socket
1899  * @args: rpc transport creation arguments
1900  *
1901  */
1902 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
1903 {
1904 	struct sockaddr *addr = args->dstaddr;
1905 	struct rpc_xprt *xprt;
1906 	struct sock_xprt *transport;
1907 
1908 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
1909 	if (IS_ERR(xprt))
1910 		return xprt;
1911 	transport = container_of(xprt, struct sock_xprt, xprt);
1912 
1913 	xprt->prot = IPPROTO_UDP;
1914 	xprt->tsh_size = 0;
1915 	/* XXX: header size can vary due to auth type, IPv6, etc. */
1916 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1917 
1918 	xprt->bind_timeout = XS_BIND_TO;
1919 	xprt->connect_timeout = XS_UDP_CONN_TO;
1920 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
1921 	xprt->idle_timeout = XS_IDLE_DISC_TO;
1922 
1923 	xprt->ops = &xs_udp_ops;
1924 
1925 	xprt->timeout = &xs_udp_default_timeout;
1926 
1927 	switch (addr->sa_family) {
1928 	case AF_INET:
1929 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
1930 			xprt_set_bound(xprt);
1931 
1932 		INIT_DELAYED_WORK(&transport->connect_worker,
1933 					xs_udp_connect_worker4);
1934 		xs_format_ipv4_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
1935 		break;
1936 	case AF_INET6:
1937 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
1938 			xprt_set_bound(xprt);
1939 
1940 		INIT_DELAYED_WORK(&transport->connect_worker,
1941 					xs_udp_connect_worker6);
1942 		xs_format_ipv6_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
1943 		break;
1944 	default:
1945 		kfree(xprt);
1946 		return ERR_PTR(-EAFNOSUPPORT);
1947 	}
1948 
1949 	dprintk("RPC:       set up transport to address %s\n",
1950 			xprt->address_strings[RPC_DISPLAY_ALL]);
1951 
1952 	if (try_module_get(THIS_MODULE))
1953 		return xprt;
1954 
1955 	kfree(xprt->slot);
1956 	kfree(xprt);
1957 	return ERR_PTR(-EINVAL);
1958 }
1959 
1960 static const struct rpc_timeout xs_tcp_default_timeout = {
1961 	.to_initval = 60 * HZ,
1962 	.to_maxval = 60 * HZ,
1963 	.to_retries = 2,
1964 };
1965 
1966 /**
1967  * xs_setup_tcp - Set up transport to use a TCP socket
1968  * @args: rpc transport creation arguments
1969  *
1970  */
1971 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
1972 {
1973 	struct sockaddr *addr = args->dstaddr;
1974 	struct rpc_xprt *xprt;
1975 	struct sock_xprt *transport;
1976 
1977 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
1978 	if (IS_ERR(xprt))
1979 		return xprt;
1980 	transport = container_of(xprt, struct sock_xprt, xprt);
1981 
1982 	xprt->prot = IPPROTO_TCP;
1983 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
1984 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
1985 
1986 	xprt->bind_timeout = XS_BIND_TO;
1987 	xprt->connect_timeout = XS_TCP_CONN_TO;
1988 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1989 	xprt->idle_timeout = XS_IDLE_DISC_TO;
1990 
1991 	xprt->ops = &xs_tcp_ops;
1992 	xprt->timeout = &xs_tcp_default_timeout;
1993 
1994 	switch (addr->sa_family) {
1995 	case AF_INET:
1996 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
1997 			xprt_set_bound(xprt);
1998 
1999 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker4);
2000 		xs_format_ipv4_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
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, xs_tcp_connect_worker6);
2007 		xs_format_ipv6_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2008 		break;
2009 	default:
2010 		kfree(xprt);
2011 		return ERR_PTR(-EAFNOSUPPORT);
2012 	}
2013 
2014 	dprintk("RPC:       set up transport to address %s\n",
2015 			xprt->address_strings[RPC_DISPLAY_ALL]);
2016 
2017 	if (try_module_get(THIS_MODULE))
2018 		return xprt;
2019 
2020 	kfree(xprt->slot);
2021 	kfree(xprt);
2022 	return ERR_PTR(-EINVAL);
2023 }
2024 
2025 static struct xprt_class	xs_udp_transport = {
2026 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2027 	.name		= "udp",
2028 	.owner		= THIS_MODULE,
2029 	.ident		= IPPROTO_UDP,
2030 	.setup		= xs_setup_udp,
2031 };
2032 
2033 static struct xprt_class	xs_tcp_transport = {
2034 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2035 	.name		= "tcp",
2036 	.owner		= THIS_MODULE,
2037 	.ident		= IPPROTO_TCP,
2038 	.setup		= xs_setup_tcp,
2039 };
2040 
2041 /**
2042  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2043  *
2044  */
2045 int init_socket_xprt(void)
2046 {
2047 #ifdef RPC_DEBUG
2048 	if (!sunrpc_table_header)
2049 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2050 #endif
2051 
2052 	xprt_register_transport(&xs_udp_transport);
2053 	xprt_register_transport(&xs_tcp_transport);
2054 
2055 	return 0;
2056 }
2057 
2058 /**
2059  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2060  *
2061  */
2062 void cleanup_socket_xprt(void)
2063 {
2064 #ifdef RPC_DEBUG
2065 	if (sunrpc_table_header) {
2066 		unregister_sysctl_table(sunrpc_table_header);
2067 		sunrpc_table_header = NULL;
2068 	}
2069 #endif
2070 
2071 	xprt_unregister_transport(&xs_udp_transport);
2072 	xprt_unregister_transport(&xs_tcp_transport);
2073 }
2074