xref: /linux/net/sunrpc/xprtsock.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/sched.h>
37 #include <linux/sunrpc/svcsock.h>
38 #include <linux/sunrpc/xprtsock.h>
39 #include <linux/file.h>
40 #ifdef CONFIG_SUNRPC_BACKCHANNEL
41 #include <linux/sunrpc/bc_xprt.h>
42 #endif
43 
44 #include <net/sock.h>
45 #include <net/checksum.h>
46 #include <net/udp.h>
47 #include <net/tcp.h>
48 
49 #include "sunrpc.h"
50 
51 static void xs_close(struct rpc_xprt *xprt);
52 
53 /*
54  * xprtsock tunables
55  */
56 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
57 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
58 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
59 
60 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
61 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
62 
63 #define XS_TCP_LINGER_TO	(15U * HZ)
64 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
65 
66 /*
67  * We can register our own files under /proc/sys/sunrpc by
68  * calling register_sysctl_table() again.  The files in that
69  * directory become the union of all files registered there.
70  *
71  * We simply need to make sure that we don't collide with
72  * someone else's file names!
73  */
74 
75 #ifdef RPC_DEBUG
76 
77 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
78 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
79 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
80 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
81 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
82 
83 static struct ctl_table_header *sunrpc_table_header;
84 
85 /*
86  * FIXME: changing the UDP slot table size should also resize the UDP
87  *        socket buffers for existing UDP transports
88  */
89 static ctl_table xs_tunables_table[] = {
90 	{
91 		.procname	= "udp_slot_table_entries",
92 		.data		= &xprt_udp_slot_table_entries,
93 		.maxlen		= sizeof(unsigned int),
94 		.mode		= 0644,
95 		.proc_handler	= proc_dointvec_minmax,
96 		.extra1		= &min_slot_table_size,
97 		.extra2		= &max_slot_table_size
98 	},
99 	{
100 		.procname	= "tcp_slot_table_entries",
101 		.data		= &xprt_tcp_slot_table_entries,
102 		.maxlen		= sizeof(unsigned int),
103 		.mode		= 0644,
104 		.proc_handler	= proc_dointvec_minmax,
105 		.extra1		= &min_slot_table_size,
106 		.extra2		= &max_slot_table_size
107 	},
108 	{
109 		.procname	= "tcp_max_slot_table_entries",
110 		.data		= &xprt_max_tcp_slot_table_entries,
111 		.maxlen		= sizeof(unsigned int),
112 		.mode		= 0644,
113 		.proc_handler	= proc_dointvec_minmax,
114 		.extra1		= &min_slot_table_size,
115 		.extra2		= &max_tcp_slot_table_limit
116 	},
117 	{
118 		.procname	= "min_resvport",
119 		.data		= &xprt_min_resvport,
120 		.maxlen		= sizeof(unsigned int),
121 		.mode		= 0644,
122 		.proc_handler	= proc_dointvec_minmax,
123 		.extra1		= &xprt_min_resvport_limit,
124 		.extra2		= &xprt_max_resvport_limit
125 	},
126 	{
127 		.procname	= "max_resvport",
128 		.data		= &xprt_max_resvport,
129 		.maxlen		= sizeof(unsigned int),
130 		.mode		= 0644,
131 		.proc_handler	= proc_dointvec_minmax,
132 		.extra1		= &xprt_min_resvport_limit,
133 		.extra2		= &xprt_max_resvport_limit
134 	},
135 	{
136 		.procname	= "tcp_fin_timeout",
137 		.data		= &xs_tcp_fin_timeout,
138 		.maxlen		= sizeof(xs_tcp_fin_timeout),
139 		.mode		= 0644,
140 		.proc_handler	= proc_dointvec_jiffies,
141 	},
142 	{ },
143 };
144 
145 static ctl_table sunrpc_table[] = {
146 	{
147 		.procname	= "sunrpc",
148 		.mode		= 0555,
149 		.child		= xs_tunables_table
150 	},
151 	{ },
152 };
153 
154 #endif
155 
156 /*
157  * Wait duration for a reply from the RPC portmapper.
158  */
159 #define XS_BIND_TO		(60U * HZ)
160 
161 /*
162  * Delay if a UDP socket connect error occurs.  This is most likely some
163  * kind of resource problem on the local host.
164  */
165 #define XS_UDP_REEST_TO		(2U * HZ)
166 
167 /*
168  * The reestablish timeout allows clients to delay for a bit before attempting
169  * to reconnect to a server that just dropped our connection.
170  *
171  * We implement an exponential backoff when trying to reestablish a TCP
172  * transport connection with the server.  Some servers like to drop a TCP
173  * connection when they are overworked, so we start with a short timeout and
174  * increase over time if the server is down or not responding.
175  */
176 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
177 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
178 
179 /*
180  * TCP idle timeout; client drops the transport socket if it is idle
181  * for this long.  Note that we also timeout UDP sockets to prevent
182  * holding port numbers when there is no RPC traffic.
183  */
184 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
185 
186 #ifdef RPC_DEBUG
187 # undef  RPC_DEBUG_DATA
188 # define RPCDBG_FACILITY	RPCDBG_TRANS
189 #endif
190 
191 #ifdef RPC_DEBUG_DATA
192 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
193 {
194 	u8 *buf = (u8 *) packet;
195 	int j;
196 
197 	dprintk("RPC:       %s\n", msg);
198 	for (j = 0; j < count && j < 128; j += 4) {
199 		if (!(j & 31)) {
200 			if (j)
201 				dprintk("\n");
202 			dprintk("0x%04x ", j);
203 		}
204 		dprintk("%02x%02x%02x%02x ",
205 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
206 	}
207 	dprintk("\n");
208 }
209 #else
210 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
211 {
212 	/* NOP */
213 }
214 #endif
215 
216 struct sock_xprt {
217 	struct rpc_xprt		xprt;
218 
219 	/*
220 	 * Network layer
221 	 */
222 	struct socket *		sock;
223 	struct sock *		inet;
224 
225 	/*
226 	 * State of TCP reply receive
227 	 */
228 	__be32			tcp_fraghdr,
229 				tcp_xid,
230 				tcp_calldir;
231 
232 	u32			tcp_offset,
233 				tcp_reclen;
234 
235 	unsigned long		tcp_copied,
236 				tcp_flags;
237 
238 	/*
239 	 * Connection of transports
240 	 */
241 	struct delayed_work	connect_worker;
242 	struct sockaddr_storage	srcaddr;
243 	unsigned short		srcport;
244 
245 	/*
246 	 * UDP socket buffer size parameters
247 	 */
248 	size_t			rcvsize,
249 				sndsize;
250 
251 	/*
252 	 * Saved socket callback addresses
253 	 */
254 	void			(*old_data_ready)(struct sock *, int);
255 	void			(*old_state_change)(struct sock *);
256 	void			(*old_write_space)(struct sock *);
257 	void			(*old_error_report)(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 #define TCP_RCV_READ_CALLDIR	(1UL << 4)
268 #define TCP_RCV_COPY_CALLDIR	(1UL << 5)
269 
270 /*
271  * TCP RPC flags
272  */
273 #define TCP_RPC_REPLY		(1UL << 6)
274 
275 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
276 {
277 	return (struct sockaddr *) &xprt->addr;
278 }
279 
280 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
281 {
282 	return (struct sockaddr_un *) &xprt->addr;
283 }
284 
285 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
286 {
287 	return (struct sockaddr_in *) &xprt->addr;
288 }
289 
290 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
291 {
292 	return (struct sockaddr_in6 *) &xprt->addr;
293 }
294 
295 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
296 {
297 	struct sockaddr *sap = xs_addr(xprt);
298 	struct sockaddr_in6 *sin6;
299 	struct sockaddr_in *sin;
300 	struct sockaddr_un *sun;
301 	char buf[128];
302 
303 	switch (sap->sa_family) {
304 	case AF_LOCAL:
305 		sun = xs_addr_un(xprt);
306 		strlcpy(buf, sun->sun_path, sizeof(buf));
307 		xprt->address_strings[RPC_DISPLAY_ADDR] =
308 						kstrdup(buf, GFP_KERNEL);
309 		break;
310 	case AF_INET:
311 		(void)rpc_ntop(sap, buf, sizeof(buf));
312 		xprt->address_strings[RPC_DISPLAY_ADDR] =
313 						kstrdup(buf, GFP_KERNEL);
314 		sin = xs_addr_in(xprt);
315 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
316 		break;
317 	case AF_INET6:
318 		(void)rpc_ntop(sap, buf, sizeof(buf));
319 		xprt->address_strings[RPC_DISPLAY_ADDR] =
320 						kstrdup(buf, GFP_KERNEL);
321 		sin6 = xs_addr_in6(xprt);
322 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
323 		break;
324 	default:
325 		BUG();
326 	}
327 
328 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
329 }
330 
331 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
332 {
333 	struct sockaddr *sap = xs_addr(xprt);
334 	char buf[128];
335 
336 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
337 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
338 
339 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
340 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
341 }
342 
343 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
344 				     const char *protocol,
345 				     const char *netid)
346 {
347 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
348 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
349 	xs_format_common_peer_addresses(xprt);
350 	xs_format_common_peer_ports(xprt);
351 }
352 
353 static void xs_update_peer_port(struct rpc_xprt *xprt)
354 {
355 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
356 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
357 
358 	xs_format_common_peer_ports(xprt);
359 }
360 
361 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
362 {
363 	unsigned int i;
364 
365 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
366 		switch (i) {
367 		case RPC_DISPLAY_PROTO:
368 		case RPC_DISPLAY_NETID:
369 			continue;
370 		default:
371 			kfree(xprt->address_strings[i]);
372 		}
373 }
374 
375 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
376 
377 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
378 {
379 	struct msghdr msg = {
380 		.msg_name	= addr,
381 		.msg_namelen	= addrlen,
382 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
383 	};
384 	struct kvec iov = {
385 		.iov_base	= vec->iov_base + base,
386 		.iov_len	= vec->iov_len - base,
387 	};
388 
389 	if (iov.iov_len != 0)
390 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
391 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
392 }
393 
394 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
395 {
396 	struct page **ppage;
397 	unsigned int remainder;
398 	int err, sent = 0;
399 
400 	remainder = xdr->page_len - base;
401 	base += xdr->page_base;
402 	ppage = xdr->pages + (base >> PAGE_SHIFT);
403 	base &= ~PAGE_MASK;
404 	for(;;) {
405 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
406 		int flags = XS_SENDMSG_FLAGS;
407 
408 		remainder -= len;
409 		if (remainder != 0 || more)
410 			flags |= MSG_MORE;
411 		err = sock->ops->sendpage(sock, *ppage, base, len, flags);
412 		if (remainder == 0 || err != len)
413 			break;
414 		sent += err;
415 		ppage++;
416 		base = 0;
417 	}
418 	if (sent == 0)
419 		return err;
420 	if (err > 0)
421 		sent += err;
422 	return sent;
423 }
424 
425 /**
426  * xs_sendpages - write pages directly to a socket
427  * @sock: socket to send on
428  * @addr: UDP only -- address of destination
429  * @addrlen: UDP only -- length of destination address
430  * @xdr: buffer containing this request
431  * @base: starting position in the buffer
432  *
433  */
434 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
435 {
436 	unsigned int remainder = xdr->len - base;
437 	int err, sent = 0;
438 
439 	if (unlikely(!sock))
440 		return -ENOTSOCK;
441 
442 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
443 	if (base != 0) {
444 		addr = NULL;
445 		addrlen = 0;
446 	}
447 
448 	if (base < xdr->head[0].iov_len || addr != NULL) {
449 		unsigned int len = xdr->head[0].iov_len - base;
450 		remainder -= len;
451 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
452 		if (remainder == 0 || err != len)
453 			goto out;
454 		sent += err;
455 		base = 0;
456 	} else
457 		base -= xdr->head[0].iov_len;
458 
459 	if (base < xdr->page_len) {
460 		unsigned int len = xdr->page_len - base;
461 		remainder -= len;
462 		err = xs_send_pagedata(sock, xdr, base, remainder != 0);
463 		if (remainder == 0 || err != len)
464 			goto out;
465 		sent += err;
466 		base = 0;
467 	} else
468 		base -= xdr->page_len;
469 
470 	if (base >= xdr->tail[0].iov_len)
471 		return sent;
472 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
473 out:
474 	if (sent == 0)
475 		return err;
476 	if (err > 0)
477 		sent += err;
478 	return sent;
479 }
480 
481 static void xs_nospace_callback(struct rpc_task *task)
482 {
483 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
484 
485 	transport->inet->sk_write_pending--;
486 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
487 }
488 
489 /**
490  * xs_nospace - place task on wait queue if transmit was incomplete
491  * @task: task to put to sleep
492  *
493  */
494 static int xs_nospace(struct rpc_task *task)
495 {
496 	struct rpc_rqst *req = task->tk_rqstp;
497 	struct rpc_xprt *xprt = req->rq_xprt;
498 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
499 	int ret = -EAGAIN;
500 
501 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
502 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
503 			req->rq_slen);
504 
505 	/* Protect against races with write_space */
506 	spin_lock_bh(&xprt->transport_lock);
507 
508 	/* Don't race with disconnect */
509 	if (xprt_connected(xprt)) {
510 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
511 			/*
512 			 * Notify TCP that we're limited by the application
513 			 * window size
514 			 */
515 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
516 			transport->inet->sk_write_pending++;
517 			/* ...and wait for more buffer space */
518 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
519 		}
520 	} else {
521 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
522 		ret = -ENOTCONN;
523 	}
524 
525 	spin_unlock_bh(&xprt->transport_lock);
526 	return ret;
527 }
528 
529 /*
530  * Construct a stream transport record marker in @buf.
531  */
532 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
533 {
534 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
535 	rpc_fraghdr *base = buf->head[0].iov_base;
536 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
537 }
538 
539 /**
540  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
541  * @task: RPC task that manages the state of an RPC request
542  *
543  * Return values:
544  *        0:	The request has been sent
545  *   EAGAIN:	The socket was blocked, please call again later to
546  *		complete the request
547  * ENOTCONN:	Caller needs to invoke connect logic then call again
548  *    other:	Some other error occured, the request was not sent
549  */
550 static int xs_local_send_request(struct rpc_task *task)
551 {
552 	struct rpc_rqst *req = task->tk_rqstp;
553 	struct rpc_xprt *xprt = req->rq_xprt;
554 	struct sock_xprt *transport =
555 				container_of(xprt, struct sock_xprt, xprt);
556 	struct xdr_buf *xdr = &req->rq_snd_buf;
557 	int status;
558 
559 	xs_encode_stream_record_marker(&req->rq_snd_buf);
560 
561 	xs_pktdump("packet data:",
562 			req->rq_svec->iov_base, req->rq_svec->iov_len);
563 
564 	status = xs_sendpages(transport->sock, NULL, 0,
565 						xdr, req->rq_bytes_sent);
566 	dprintk("RPC:       %s(%u) = %d\n",
567 			__func__, xdr->len - req->rq_bytes_sent, status);
568 	if (likely(status >= 0)) {
569 		req->rq_bytes_sent += status;
570 		req->rq_xmit_bytes_sent += status;
571 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
572 			req->rq_bytes_sent = 0;
573 			return 0;
574 		}
575 		status = -EAGAIN;
576 	}
577 
578 	switch (status) {
579 	case -EAGAIN:
580 		status = xs_nospace(task);
581 		break;
582 	default:
583 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
584 			-status);
585 	case -EPIPE:
586 		xs_close(xprt);
587 		status = -ENOTCONN;
588 	}
589 
590 	return status;
591 }
592 
593 /**
594  * xs_udp_send_request - write an RPC request to a UDP socket
595  * @task: address of RPC task that manages the state of an RPC request
596  *
597  * Return values:
598  *        0:	The request has been sent
599  *   EAGAIN:	The socket was blocked, please call again later to
600  *		complete the request
601  * ENOTCONN:	Caller needs to invoke connect logic then call again
602  *    other:	Some other error occurred, the request was not sent
603  */
604 static int xs_udp_send_request(struct rpc_task *task)
605 {
606 	struct rpc_rqst *req = task->tk_rqstp;
607 	struct rpc_xprt *xprt = req->rq_xprt;
608 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
609 	struct xdr_buf *xdr = &req->rq_snd_buf;
610 	int status;
611 
612 	xs_pktdump("packet data:",
613 				req->rq_svec->iov_base,
614 				req->rq_svec->iov_len);
615 
616 	if (!xprt_bound(xprt))
617 		return -ENOTCONN;
618 	status = xs_sendpages(transport->sock,
619 			      xs_addr(xprt),
620 			      xprt->addrlen, xdr,
621 			      req->rq_bytes_sent);
622 
623 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
624 			xdr->len - req->rq_bytes_sent, status);
625 
626 	if (status >= 0) {
627 		req->rq_xmit_bytes_sent += status;
628 		if (status >= req->rq_slen)
629 			return 0;
630 		/* Still some bytes left; set up for a retry later. */
631 		status = -EAGAIN;
632 	}
633 
634 	switch (status) {
635 	case -ENOTSOCK:
636 		status = -ENOTCONN;
637 		/* Should we call xs_close() here? */
638 		break;
639 	case -EAGAIN:
640 		status = xs_nospace(task);
641 		break;
642 	default:
643 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
644 			-status);
645 	case -ENETUNREACH:
646 	case -EPIPE:
647 	case -ECONNREFUSED:
648 		/* When the server has died, an ICMP port unreachable message
649 		 * prompts ECONNREFUSED. */
650 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
651 	}
652 
653 	return status;
654 }
655 
656 /**
657  * xs_tcp_shutdown - gracefully shut down a TCP socket
658  * @xprt: transport
659  *
660  * Initiates a graceful shutdown of the TCP socket by calling the
661  * equivalent of shutdown(SHUT_WR);
662  */
663 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
664 {
665 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
666 	struct socket *sock = transport->sock;
667 
668 	if (sock != NULL)
669 		kernel_sock_shutdown(sock, SHUT_WR);
670 }
671 
672 /**
673  * xs_tcp_send_request - write an RPC request to a TCP socket
674  * @task: address of RPC task that manages the state of an RPC request
675  *
676  * Return values:
677  *        0:	The request has been sent
678  *   EAGAIN:	The socket was blocked, please call again later to
679  *		complete the request
680  * ENOTCONN:	Caller needs to invoke connect logic then call again
681  *    other:	Some other error occurred, the request was not sent
682  *
683  * XXX: In the case of soft timeouts, should we eventually give up
684  *	if sendmsg is not able to make progress?
685  */
686 static int xs_tcp_send_request(struct rpc_task *task)
687 {
688 	struct rpc_rqst *req = task->tk_rqstp;
689 	struct rpc_xprt *xprt = req->rq_xprt;
690 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
691 	struct xdr_buf *xdr = &req->rq_snd_buf;
692 	int status;
693 
694 	xs_encode_stream_record_marker(&req->rq_snd_buf);
695 
696 	xs_pktdump("packet data:",
697 				req->rq_svec->iov_base,
698 				req->rq_svec->iov_len);
699 
700 	/* Continue transmitting the packet/record. We must be careful
701 	 * to cope with writespace callbacks arriving _after_ we have
702 	 * called sendmsg(). */
703 	while (1) {
704 		status = xs_sendpages(transport->sock,
705 					NULL, 0, xdr, req->rq_bytes_sent);
706 
707 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
708 				xdr->len - req->rq_bytes_sent, status);
709 
710 		if (unlikely(status < 0))
711 			break;
712 
713 		/* If we've sent the entire packet, immediately
714 		 * reset the count of bytes sent. */
715 		req->rq_bytes_sent += status;
716 		req->rq_xmit_bytes_sent += status;
717 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
718 			req->rq_bytes_sent = 0;
719 			return 0;
720 		}
721 
722 		if (status != 0)
723 			continue;
724 		status = -EAGAIN;
725 		break;
726 	}
727 
728 	switch (status) {
729 	case -ENOTSOCK:
730 		status = -ENOTCONN;
731 		/* Should we call xs_close() here? */
732 		break;
733 	case -EAGAIN:
734 		status = xs_nospace(task);
735 		break;
736 	default:
737 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
738 			-status);
739 	case -ECONNRESET:
740 	case -EPIPE:
741 		xs_tcp_shutdown(xprt);
742 	case -ECONNREFUSED:
743 	case -ENOTCONN:
744 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
745 	}
746 
747 	return status;
748 }
749 
750 /**
751  * xs_tcp_release_xprt - clean up after a tcp transmission
752  * @xprt: transport
753  * @task: rpc task
754  *
755  * This cleans up if an error causes us to abort the transmission of a request.
756  * In this case, the socket may need to be reset in order to avoid confusing
757  * the server.
758  */
759 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
760 {
761 	struct rpc_rqst *req;
762 
763 	if (task != xprt->snd_task)
764 		return;
765 	if (task == NULL)
766 		goto out_release;
767 	req = task->tk_rqstp;
768 	if (req == NULL)
769 		goto out_release;
770 	if (req->rq_bytes_sent == 0)
771 		goto out_release;
772 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
773 		goto out_release;
774 	set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
775 out_release:
776 	xprt_release_xprt(xprt, task);
777 }
778 
779 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
780 {
781 	transport->old_data_ready = sk->sk_data_ready;
782 	transport->old_state_change = sk->sk_state_change;
783 	transport->old_write_space = sk->sk_write_space;
784 	transport->old_error_report = sk->sk_error_report;
785 }
786 
787 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
788 {
789 	sk->sk_data_ready = transport->old_data_ready;
790 	sk->sk_state_change = transport->old_state_change;
791 	sk->sk_write_space = transport->old_write_space;
792 	sk->sk_error_report = transport->old_error_report;
793 }
794 
795 static void xs_reset_transport(struct sock_xprt *transport)
796 {
797 	struct socket *sock = transport->sock;
798 	struct sock *sk = transport->inet;
799 
800 	if (sk == NULL)
801 		return;
802 
803 	transport->srcport = 0;
804 
805 	write_lock_bh(&sk->sk_callback_lock);
806 	transport->inet = NULL;
807 	transport->sock = NULL;
808 
809 	sk->sk_user_data = NULL;
810 
811 	xs_restore_old_callbacks(transport, sk);
812 	write_unlock_bh(&sk->sk_callback_lock);
813 
814 	sk->sk_no_check = 0;
815 
816 	sock_release(sock);
817 }
818 
819 /**
820  * xs_close - close a socket
821  * @xprt: transport
822  *
823  * This is used when all requests are complete; ie, no DRC state remains
824  * on the server we want to save.
825  *
826  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
827  * xs_reset_transport() zeroing the socket from underneath a writer.
828  */
829 static void xs_close(struct rpc_xprt *xprt)
830 {
831 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
832 
833 	dprintk("RPC:       xs_close xprt %p\n", xprt);
834 
835 	xs_reset_transport(transport);
836 	xprt->reestablish_timeout = 0;
837 
838 	smp_mb__before_clear_bit();
839 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
840 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
841 	clear_bit(XPRT_CLOSING, &xprt->state);
842 	smp_mb__after_clear_bit();
843 	xprt_disconnect_done(xprt);
844 }
845 
846 static void xs_tcp_close(struct rpc_xprt *xprt)
847 {
848 	if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
849 		xs_close(xprt);
850 	else
851 		xs_tcp_shutdown(xprt);
852 }
853 
854 /**
855  * xs_destroy - prepare to shutdown a transport
856  * @xprt: doomed transport
857  *
858  */
859 static void xs_destroy(struct rpc_xprt *xprt)
860 {
861 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
862 
863 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
864 
865 	cancel_delayed_work_sync(&transport->connect_worker);
866 
867 	xs_close(xprt);
868 	xs_free_peer_addresses(xprt);
869 	xprt_free(xprt);
870 	module_put(THIS_MODULE);
871 }
872 
873 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
874 {
875 	return (struct rpc_xprt *) sk->sk_user_data;
876 }
877 
878 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
879 {
880 	struct xdr_skb_reader desc = {
881 		.skb		= skb,
882 		.offset		= sizeof(rpc_fraghdr),
883 		.count		= skb->len - sizeof(rpc_fraghdr),
884 	};
885 
886 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
887 		return -1;
888 	if (desc.count)
889 		return -1;
890 	return 0;
891 }
892 
893 /**
894  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
895  * @sk: socket with data to read
896  * @len: how much data to read
897  *
898  * Currently this assumes we can read the whole reply in a single gulp.
899  */
900 static void xs_local_data_ready(struct sock *sk, int len)
901 {
902 	struct rpc_task *task;
903 	struct rpc_xprt *xprt;
904 	struct rpc_rqst *rovr;
905 	struct sk_buff *skb;
906 	int err, repsize, copied;
907 	u32 _xid;
908 	__be32 *xp;
909 
910 	read_lock_bh(&sk->sk_callback_lock);
911 	dprintk("RPC:       %s...\n", __func__);
912 	xprt = xprt_from_sock(sk);
913 	if (xprt == NULL)
914 		goto out;
915 
916 	skb = skb_recv_datagram(sk, 0, 1, &err);
917 	if (skb == NULL)
918 		goto out;
919 
920 	if (xprt->shutdown)
921 		goto dropit;
922 
923 	repsize = skb->len - sizeof(rpc_fraghdr);
924 	if (repsize < 4) {
925 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
926 		goto dropit;
927 	}
928 
929 	/* Copy the XID from the skb... */
930 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
931 	if (xp == NULL)
932 		goto dropit;
933 
934 	/* Look up and lock the request corresponding to the given XID */
935 	spin_lock(&xprt->transport_lock);
936 	rovr = xprt_lookup_rqst(xprt, *xp);
937 	if (!rovr)
938 		goto out_unlock;
939 	task = rovr->rq_task;
940 
941 	copied = rovr->rq_private_buf.buflen;
942 	if (copied > repsize)
943 		copied = repsize;
944 
945 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
946 		dprintk("RPC:       sk_buff copy failed\n");
947 		goto out_unlock;
948 	}
949 
950 	xprt_complete_rqst(task, copied);
951 
952  out_unlock:
953 	spin_unlock(&xprt->transport_lock);
954  dropit:
955 	skb_free_datagram(sk, skb);
956  out:
957 	read_unlock_bh(&sk->sk_callback_lock);
958 }
959 
960 /**
961  * xs_udp_data_ready - "data ready" callback for UDP sockets
962  * @sk: socket with data to read
963  * @len: how much data to read
964  *
965  */
966 static void xs_udp_data_ready(struct sock *sk, int len)
967 {
968 	struct rpc_task *task;
969 	struct rpc_xprt *xprt;
970 	struct rpc_rqst *rovr;
971 	struct sk_buff *skb;
972 	int err, repsize, copied;
973 	u32 _xid;
974 	__be32 *xp;
975 
976 	read_lock_bh(&sk->sk_callback_lock);
977 	dprintk("RPC:       xs_udp_data_ready...\n");
978 	if (!(xprt = xprt_from_sock(sk)))
979 		goto out;
980 
981 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
982 		goto out;
983 
984 	if (xprt->shutdown)
985 		goto dropit;
986 
987 	repsize = skb->len - sizeof(struct udphdr);
988 	if (repsize < 4) {
989 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
990 		goto dropit;
991 	}
992 
993 	/* Copy the XID from the skb... */
994 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
995 				sizeof(_xid), &_xid);
996 	if (xp == NULL)
997 		goto dropit;
998 
999 	/* Look up and lock the request corresponding to the given XID */
1000 	spin_lock(&xprt->transport_lock);
1001 	rovr = xprt_lookup_rqst(xprt, *xp);
1002 	if (!rovr)
1003 		goto out_unlock;
1004 	task = rovr->rq_task;
1005 
1006 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1007 		copied = repsize;
1008 
1009 	/* Suck it into the iovec, verify checksum if not done by hw. */
1010 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1011 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1012 		goto out_unlock;
1013 	}
1014 
1015 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1016 
1017 	xprt_adjust_cwnd(task, copied);
1018 	xprt_complete_rqst(task, copied);
1019 
1020  out_unlock:
1021 	spin_unlock(&xprt->transport_lock);
1022  dropit:
1023 	skb_free_datagram(sk, skb);
1024  out:
1025 	read_unlock_bh(&sk->sk_callback_lock);
1026 }
1027 
1028 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1029 {
1030 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1031 	size_t len, used;
1032 	char *p;
1033 
1034 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1035 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1036 	used = xdr_skb_read_bits(desc, p, len);
1037 	transport->tcp_offset += used;
1038 	if (used != len)
1039 		return;
1040 
1041 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1042 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1043 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1044 	else
1045 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1046 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1047 
1048 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1049 	transport->tcp_offset = 0;
1050 
1051 	/* Sanity check of the record length */
1052 	if (unlikely(transport->tcp_reclen < 8)) {
1053 		dprintk("RPC:       invalid TCP record fragment length\n");
1054 		xprt_force_disconnect(xprt);
1055 		return;
1056 	}
1057 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1058 			transport->tcp_reclen);
1059 }
1060 
1061 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1062 {
1063 	if (transport->tcp_offset == transport->tcp_reclen) {
1064 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1065 		transport->tcp_offset = 0;
1066 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1067 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1068 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1069 			transport->tcp_copied = 0;
1070 		}
1071 	}
1072 }
1073 
1074 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1075 {
1076 	size_t len, used;
1077 	char *p;
1078 
1079 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1080 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1081 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1082 	used = xdr_skb_read_bits(desc, p, len);
1083 	transport->tcp_offset += used;
1084 	if (used != len)
1085 		return;
1086 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1087 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1088 	transport->tcp_copied = 4;
1089 	dprintk("RPC:       reading %s XID %08x\n",
1090 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1091 							      : "request with",
1092 			ntohl(transport->tcp_xid));
1093 	xs_tcp_check_fraghdr(transport);
1094 }
1095 
1096 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1097 				       struct xdr_skb_reader *desc)
1098 {
1099 	size_t len, used;
1100 	u32 offset;
1101 	char *p;
1102 
1103 	/*
1104 	 * We want transport->tcp_offset to be 8 at the end of this routine
1105 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1106 	 * When this function is called for the first time,
1107 	 * transport->tcp_offset is 4 (after having already read the xid).
1108 	 */
1109 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1110 	len = sizeof(transport->tcp_calldir) - offset;
1111 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1112 	p = ((char *) &transport->tcp_calldir) + offset;
1113 	used = xdr_skb_read_bits(desc, p, len);
1114 	transport->tcp_offset += used;
1115 	if (used != len)
1116 		return;
1117 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1118 	/*
1119 	 * We don't yet have the XDR buffer, so we will write the calldir
1120 	 * out after we get the buffer from the 'struct rpc_rqst'
1121 	 */
1122 	switch (ntohl(transport->tcp_calldir)) {
1123 	case RPC_REPLY:
1124 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1125 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1126 		transport->tcp_flags |= TCP_RPC_REPLY;
1127 		break;
1128 	case RPC_CALL:
1129 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1130 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1131 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1132 		break;
1133 	default:
1134 		dprintk("RPC:       invalid request message type\n");
1135 		xprt_force_disconnect(&transport->xprt);
1136 	}
1137 	xs_tcp_check_fraghdr(transport);
1138 }
1139 
1140 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1141 				     struct xdr_skb_reader *desc,
1142 				     struct rpc_rqst *req)
1143 {
1144 	struct sock_xprt *transport =
1145 				container_of(xprt, struct sock_xprt, xprt);
1146 	struct xdr_buf *rcvbuf;
1147 	size_t len;
1148 	ssize_t r;
1149 
1150 	rcvbuf = &req->rq_private_buf;
1151 
1152 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1153 		/*
1154 		 * Save the RPC direction in the XDR buffer
1155 		 */
1156 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1157 			&transport->tcp_calldir,
1158 			sizeof(transport->tcp_calldir));
1159 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1160 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1161 	}
1162 
1163 	len = desc->count;
1164 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1165 		struct xdr_skb_reader my_desc;
1166 
1167 		len = transport->tcp_reclen - transport->tcp_offset;
1168 		memcpy(&my_desc, desc, sizeof(my_desc));
1169 		my_desc.count = len;
1170 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1171 					  &my_desc, xdr_skb_read_bits);
1172 		desc->count -= r;
1173 		desc->offset += r;
1174 	} else
1175 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1176 					  desc, xdr_skb_read_bits);
1177 
1178 	if (r > 0) {
1179 		transport->tcp_copied += r;
1180 		transport->tcp_offset += r;
1181 	}
1182 	if (r != len) {
1183 		/* Error when copying to the receive buffer,
1184 		 * usually because we weren't able to allocate
1185 		 * additional buffer pages. All we can do now
1186 		 * is turn off TCP_RCV_COPY_DATA, so the request
1187 		 * will not receive any additional updates,
1188 		 * and time out.
1189 		 * Any remaining data from this record will
1190 		 * be discarded.
1191 		 */
1192 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1193 		dprintk("RPC:       XID %08x truncated request\n",
1194 				ntohl(transport->tcp_xid));
1195 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1196 				"tcp_offset = %u, tcp_reclen = %u\n",
1197 				xprt, transport->tcp_copied,
1198 				transport->tcp_offset, transport->tcp_reclen);
1199 		return;
1200 	}
1201 
1202 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1203 			ntohl(transport->tcp_xid), r);
1204 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1205 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1206 			transport->tcp_offset, transport->tcp_reclen);
1207 
1208 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1209 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1210 	else if (transport->tcp_offset == transport->tcp_reclen) {
1211 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1212 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1213 	}
1214 }
1215 
1216 /*
1217  * Finds the request corresponding to the RPC xid and invokes the common
1218  * tcp read code to read the data.
1219  */
1220 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1221 				    struct xdr_skb_reader *desc)
1222 {
1223 	struct sock_xprt *transport =
1224 				container_of(xprt, struct sock_xprt, xprt);
1225 	struct rpc_rqst *req;
1226 
1227 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1228 
1229 	/* Find and lock the request corresponding to this xid */
1230 	spin_lock(&xprt->transport_lock);
1231 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1232 	if (!req) {
1233 		dprintk("RPC:       XID %08x request not found!\n",
1234 				ntohl(transport->tcp_xid));
1235 		spin_unlock(&xprt->transport_lock);
1236 		return -1;
1237 	}
1238 
1239 	xs_tcp_read_common(xprt, desc, req);
1240 
1241 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1242 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1243 
1244 	spin_unlock(&xprt->transport_lock);
1245 	return 0;
1246 }
1247 
1248 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1249 /*
1250  * Obtains an rpc_rqst previously allocated and invokes the common
1251  * tcp read code to read the data.  The result is placed in the callback
1252  * queue.
1253  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1254  * connection and return -1.
1255  */
1256 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1257 				       struct xdr_skb_reader *desc)
1258 {
1259 	struct sock_xprt *transport =
1260 				container_of(xprt, struct sock_xprt, xprt);
1261 	struct rpc_rqst *req;
1262 
1263 	req = xprt_alloc_bc_request(xprt);
1264 	if (req == NULL) {
1265 		printk(KERN_WARNING "Callback slot table overflowed\n");
1266 		xprt_force_disconnect(xprt);
1267 		return -1;
1268 	}
1269 
1270 	req->rq_xid = transport->tcp_xid;
1271 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1272 	xs_tcp_read_common(xprt, desc, req);
1273 
1274 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1275 		struct svc_serv *bc_serv = xprt->bc_serv;
1276 
1277 		/*
1278 		 * Add callback request to callback list.  The callback
1279 		 * service sleeps on the sv_cb_waitq waiting for new
1280 		 * requests.  Wake it up after adding enqueing the
1281 		 * request.
1282 		 */
1283 		dprintk("RPC:       add callback request to list\n");
1284 		spin_lock(&bc_serv->sv_cb_lock);
1285 		list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1286 		spin_unlock(&bc_serv->sv_cb_lock);
1287 		wake_up(&bc_serv->sv_cb_waitq);
1288 	}
1289 
1290 	req->rq_private_buf.len = transport->tcp_copied;
1291 
1292 	return 0;
1293 }
1294 
1295 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1296 					struct xdr_skb_reader *desc)
1297 {
1298 	struct sock_xprt *transport =
1299 				container_of(xprt, struct sock_xprt, xprt);
1300 
1301 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1302 		xs_tcp_read_reply(xprt, desc) :
1303 		xs_tcp_read_callback(xprt, desc);
1304 }
1305 #else
1306 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1307 					struct xdr_skb_reader *desc)
1308 {
1309 	return xs_tcp_read_reply(xprt, desc);
1310 }
1311 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1312 
1313 /*
1314  * Read data off the transport.  This can be either an RPC_CALL or an
1315  * RPC_REPLY.  Relay the processing to helper functions.
1316  */
1317 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1318 				    struct xdr_skb_reader *desc)
1319 {
1320 	struct sock_xprt *transport =
1321 				container_of(xprt, struct sock_xprt, xprt);
1322 
1323 	if (_xs_tcp_read_data(xprt, desc) == 0)
1324 		xs_tcp_check_fraghdr(transport);
1325 	else {
1326 		/*
1327 		 * The transport_lock protects the request handling.
1328 		 * There's no need to hold it to update the tcp_flags.
1329 		 */
1330 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1331 	}
1332 }
1333 
1334 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1335 {
1336 	size_t len;
1337 
1338 	len = transport->tcp_reclen - transport->tcp_offset;
1339 	if (len > desc->count)
1340 		len = desc->count;
1341 	desc->count -= len;
1342 	desc->offset += len;
1343 	transport->tcp_offset += len;
1344 	dprintk("RPC:       discarded %Zu bytes\n", len);
1345 	xs_tcp_check_fraghdr(transport);
1346 }
1347 
1348 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1349 {
1350 	struct rpc_xprt *xprt = rd_desc->arg.data;
1351 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1352 	struct xdr_skb_reader desc = {
1353 		.skb	= skb,
1354 		.offset	= offset,
1355 		.count	= len,
1356 	};
1357 
1358 	dprintk("RPC:       xs_tcp_data_recv started\n");
1359 	do {
1360 		/* Read in a new fragment marker if necessary */
1361 		/* Can we ever really expect to get completely empty fragments? */
1362 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1363 			xs_tcp_read_fraghdr(xprt, &desc);
1364 			continue;
1365 		}
1366 		/* Read in the xid if necessary */
1367 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1368 			xs_tcp_read_xid(transport, &desc);
1369 			continue;
1370 		}
1371 		/* Read in the call/reply flag */
1372 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1373 			xs_tcp_read_calldir(transport, &desc);
1374 			continue;
1375 		}
1376 		/* Read in the request data */
1377 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1378 			xs_tcp_read_data(xprt, &desc);
1379 			continue;
1380 		}
1381 		/* Skip over any trailing bytes on short reads */
1382 		xs_tcp_read_discard(transport, &desc);
1383 	} while (desc.count);
1384 	dprintk("RPC:       xs_tcp_data_recv done\n");
1385 	return len - desc.count;
1386 }
1387 
1388 /**
1389  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1390  * @sk: socket with data to read
1391  * @bytes: how much data to read
1392  *
1393  */
1394 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1395 {
1396 	struct rpc_xprt *xprt;
1397 	read_descriptor_t rd_desc;
1398 	int read;
1399 
1400 	dprintk("RPC:       xs_tcp_data_ready...\n");
1401 
1402 	read_lock_bh(&sk->sk_callback_lock);
1403 	if (!(xprt = xprt_from_sock(sk)))
1404 		goto out;
1405 	if (xprt->shutdown)
1406 		goto out;
1407 
1408 	/* Any data means we had a useful conversation, so
1409 	 * the we don't need to delay the next reconnect
1410 	 */
1411 	if (xprt->reestablish_timeout)
1412 		xprt->reestablish_timeout = 0;
1413 
1414 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1415 	rd_desc.arg.data = xprt;
1416 	do {
1417 		rd_desc.count = 65536;
1418 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1419 	} while (read > 0);
1420 out:
1421 	read_unlock_bh(&sk->sk_callback_lock);
1422 }
1423 
1424 /*
1425  * Do the equivalent of linger/linger2 handling for dealing with
1426  * broken servers that don't close the socket in a timely
1427  * fashion
1428  */
1429 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1430 		unsigned long timeout)
1431 {
1432 	struct sock_xprt *transport;
1433 
1434 	if (xprt_test_and_set_connecting(xprt))
1435 		return;
1436 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1437 	transport = container_of(xprt, struct sock_xprt, xprt);
1438 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1439 			   timeout);
1440 }
1441 
1442 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1443 {
1444 	struct sock_xprt *transport;
1445 
1446 	transport = container_of(xprt, struct sock_xprt, xprt);
1447 
1448 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1449 	    !cancel_delayed_work(&transport->connect_worker))
1450 		return;
1451 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1452 	xprt_clear_connecting(xprt);
1453 }
1454 
1455 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1456 {
1457 	smp_mb__before_clear_bit();
1458 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1459 	clear_bit(XPRT_CLOSING, &xprt->state);
1460 	smp_mb__after_clear_bit();
1461 	/* Mark transport as closed and wake up all pending tasks */
1462 	xprt_disconnect_done(xprt);
1463 }
1464 
1465 /**
1466  * xs_tcp_state_change - callback to handle TCP socket state changes
1467  * @sk: socket whose state has changed
1468  *
1469  */
1470 static void xs_tcp_state_change(struct sock *sk)
1471 {
1472 	struct rpc_xprt *xprt;
1473 
1474 	read_lock_bh(&sk->sk_callback_lock);
1475 	if (!(xprt = xprt_from_sock(sk)))
1476 		goto out;
1477 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1478 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1479 			sk->sk_state, xprt_connected(xprt),
1480 			sock_flag(sk, SOCK_DEAD),
1481 			sock_flag(sk, SOCK_ZAPPED),
1482 			sk->sk_shutdown);
1483 
1484 	switch (sk->sk_state) {
1485 	case TCP_ESTABLISHED:
1486 		spin_lock(&xprt->transport_lock);
1487 		if (!xprt_test_and_set_connected(xprt)) {
1488 			struct sock_xprt *transport = container_of(xprt,
1489 					struct sock_xprt, xprt);
1490 
1491 			/* Reset TCP record info */
1492 			transport->tcp_offset = 0;
1493 			transport->tcp_reclen = 0;
1494 			transport->tcp_copied = 0;
1495 			transport->tcp_flags =
1496 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1497 
1498 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1499 		}
1500 		spin_unlock(&xprt->transport_lock);
1501 		break;
1502 	case TCP_FIN_WAIT1:
1503 		/* The client initiated a shutdown of the socket */
1504 		xprt->connect_cookie++;
1505 		xprt->reestablish_timeout = 0;
1506 		set_bit(XPRT_CLOSING, &xprt->state);
1507 		smp_mb__before_clear_bit();
1508 		clear_bit(XPRT_CONNECTED, &xprt->state);
1509 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1510 		smp_mb__after_clear_bit();
1511 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1512 		break;
1513 	case TCP_CLOSE_WAIT:
1514 		/* The server initiated a shutdown of the socket */
1515 		xprt_force_disconnect(xprt);
1516 		xprt->connect_cookie++;
1517 	case TCP_CLOSING:
1518 		/*
1519 		 * If the server closed down the connection, make sure that
1520 		 * we back off before reconnecting
1521 		 */
1522 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1523 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1524 		break;
1525 	case TCP_LAST_ACK:
1526 		set_bit(XPRT_CLOSING, &xprt->state);
1527 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1528 		smp_mb__before_clear_bit();
1529 		clear_bit(XPRT_CONNECTED, &xprt->state);
1530 		smp_mb__after_clear_bit();
1531 		break;
1532 	case TCP_CLOSE:
1533 		xs_tcp_cancel_linger_timeout(xprt);
1534 		xs_sock_mark_closed(xprt);
1535 	}
1536  out:
1537 	read_unlock_bh(&sk->sk_callback_lock);
1538 }
1539 
1540 /**
1541  * xs_error_report - callback mainly for catching socket errors
1542  * @sk: socket
1543  */
1544 static void xs_error_report(struct sock *sk)
1545 {
1546 	struct rpc_xprt *xprt;
1547 
1548 	read_lock_bh(&sk->sk_callback_lock);
1549 	if (!(xprt = xprt_from_sock(sk)))
1550 		goto out;
1551 	dprintk("RPC:       %s client %p...\n"
1552 			"RPC:       error %d\n",
1553 			__func__, xprt, sk->sk_err);
1554 	xprt_wake_pending_tasks(xprt, -EAGAIN);
1555 out:
1556 	read_unlock_bh(&sk->sk_callback_lock);
1557 }
1558 
1559 static void xs_write_space(struct sock *sk)
1560 {
1561 	struct socket *sock;
1562 	struct rpc_xprt *xprt;
1563 
1564 	if (unlikely(!(sock = sk->sk_socket)))
1565 		return;
1566 	clear_bit(SOCK_NOSPACE, &sock->flags);
1567 
1568 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1569 		return;
1570 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1571 		return;
1572 
1573 	xprt_write_space(xprt);
1574 }
1575 
1576 /**
1577  * xs_udp_write_space - callback invoked when socket buffer space
1578  *                             becomes available
1579  * @sk: socket whose state has changed
1580  *
1581  * Called when more output buffer space is available for this socket.
1582  * We try not to wake our writers until they can make "significant"
1583  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1584  * with a bunch of small requests.
1585  */
1586 static void xs_udp_write_space(struct sock *sk)
1587 {
1588 	read_lock_bh(&sk->sk_callback_lock);
1589 
1590 	/* from net/core/sock.c:sock_def_write_space */
1591 	if (sock_writeable(sk))
1592 		xs_write_space(sk);
1593 
1594 	read_unlock_bh(&sk->sk_callback_lock);
1595 }
1596 
1597 /**
1598  * xs_tcp_write_space - callback invoked when socket buffer space
1599  *                             becomes available
1600  * @sk: socket whose state has changed
1601  *
1602  * Called when more output buffer space is available for this socket.
1603  * We try not to wake our writers until they can make "significant"
1604  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1605  * with a bunch of small requests.
1606  */
1607 static void xs_tcp_write_space(struct sock *sk)
1608 {
1609 	read_lock_bh(&sk->sk_callback_lock);
1610 
1611 	/* from net/core/stream.c:sk_stream_write_space */
1612 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
1613 		xs_write_space(sk);
1614 
1615 	read_unlock_bh(&sk->sk_callback_lock);
1616 }
1617 
1618 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1619 {
1620 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1621 	struct sock *sk = transport->inet;
1622 
1623 	if (transport->rcvsize) {
1624 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1625 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1626 	}
1627 	if (transport->sndsize) {
1628 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1629 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1630 		sk->sk_write_space(sk);
1631 	}
1632 }
1633 
1634 /**
1635  * xs_udp_set_buffer_size - set send and receive limits
1636  * @xprt: generic transport
1637  * @sndsize: requested size of send buffer, in bytes
1638  * @rcvsize: requested size of receive buffer, in bytes
1639  *
1640  * Set socket send and receive buffer size limits.
1641  */
1642 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1643 {
1644 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1645 
1646 	transport->sndsize = 0;
1647 	if (sndsize)
1648 		transport->sndsize = sndsize + 1024;
1649 	transport->rcvsize = 0;
1650 	if (rcvsize)
1651 		transport->rcvsize = rcvsize + 1024;
1652 
1653 	xs_udp_do_set_buffer_size(xprt);
1654 }
1655 
1656 /**
1657  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1658  * @task: task that timed out
1659  *
1660  * Adjust the congestion window after a retransmit timeout has occurred.
1661  */
1662 static void xs_udp_timer(struct rpc_task *task)
1663 {
1664 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1665 }
1666 
1667 static unsigned short xs_get_random_port(void)
1668 {
1669 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1670 	unsigned short rand = (unsigned short) net_random() % range;
1671 	return rand + xprt_min_resvport;
1672 }
1673 
1674 /**
1675  * xs_set_port - reset the port number in the remote endpoint address
1676  * @xprt: generic transport
1677  * @port: new port number
1678  *
1679  */
1680 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1681 {
1682 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1683 
1684 	rpc_set_port(xs_addr(xprt), port);
1685 	xs_update_peer_port(xprt);
1686 }
1687 
1688 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1689 {
1690 	unsigned short port = transport->srcport;
1691 
1692 	if (port == 0 && transport->xprt.resvport)
1693 		port = xs_get_random_port();
1694 	return port;
1695 }
1696 
1697 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1698 {
1699 	if (transport->srcport != 0)
1700 		transport->srcport = 0;
1701 	if (!transport->xprt.resvport)
1702 		return 0;
1703 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1704 		return xprt_max_resvport;
1705 	return --port;
1706 }
1707 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1708 {
1709 	struct sockaddr_storage myaddr;
1710 	int err, nloop = 0;
1711 	unsigned short port = xs_get_srcport(transport);
1712 	unsigned short last;
1713 
1714 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1715 	do {
1716 		rpc_set_port((struct sockaddr *)&myaddr, port);
1717 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1718 				transport->xprt.addrlen);
1719 		if (port == 0)
1720 			break;
1721 		if (err == 0) {
1722 			transport->srcport = port;
1723 			break;
1724 		}
1725 		last = port;
1726 		port = xs_next_srcport(transport, port);
1727 		if (port > last)
1728 			nloop++;
1729 	} while (err == -EADDRINUSE && nloop != 2);
1730 
1731 	if (myaddr.ss_family == AF_INET)
1732 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1733 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1734 				port, err ? "failed" : "ok", err);
1735 	else
1736 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1737 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1738 				port, err ? "failed" : "ok", err);
1739 	return err;
1740 }
1741 
1742 /*
1743  * We don't support autobind on AF_LOCAL sockets
1744  */
1745 static void xs_local_rpcbind(struct rpc_task *task)
1746 {
1747 	xprt_set_bound(task->tk_xprt);
1748 }
1749 
1750 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1751 {
1752 }
1753 
1754 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1755 static struct lock_class_key xs_key[2];
1756 static struct lock_class_key xs_slock_key[2];
1757 
1758 static inline void xs_reclassify_socketu(struct socket *sock)
1759 {
1760 	struct sock *sk = sock->sk;
1761 
1762 	BUG_ON(sock_owned_by_user(sk));
1763 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1764 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1765 }
1766 
1767 static inline void xs_reclassify_socket4(struct socket *sock)
1768 {
1769 	struct sock *sk = sock->sk;
1770 
1771 	BUG_ON(sock_owned_by_user(sk));
1772 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1773 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1774 }
1775 
1776 static inline void xs_reclassify_socket6(struct socket *sock)
1777 {
1778 	struct sock *sk = sock->sk;
1779 
1780 	BUG_ON(sock_owned_by_user(sk));
1781 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1782 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1783 }
1784 
1785 static inline void xs_reclassify_socket(int family, struct socket *sock)
1786 {
1787 	switch (family) {
1788 	case AF_LOCAL:
1789 		xs_reclassify_socketu(sock);
1790 		break;
1791 	case AF_INET:
1792 		xs_reclassify_socket4(sock);
1793 		break;
1794 	case AF_INET6:
1795 		xs_reclassify_socket6(sock);
1796 		break;
1797 	}
1798 }
1799 #else
1800 static inline void xs_reclassify_socketu(struct socket *sock)
1801 {
1802 }
1803 
1804 static inline void xs_reclassify_socket4(struct socket *sock)
1805 {
1806 }
1807 
1808 static inline void xs_reclassify_socket6(struct socket *sock)
1809 {
1810 }
1811 
1812 static inline void xs_reclassify_socket(int family, struct socket *sock)
1813 {
1814 }
1815 #endif
1816 
1817 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1818 		struct sock_xprt *transport, int family, int type, int protocol)
1819 {
1820 	struct socket *sock;
1821 	int err;
1822 
1823 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1824 	if (err < 0) {
1825 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1826 				protocol, -err);
1827 		goto out;
1828 	}
1829 	xs_reclassify_socket(family, sock);
1830 
1831 	err = xs_bind(transport, sock);
1832 	if (err) {
1833 		sock_release(sock);
1834 		goto out;
1835 	}
1836 
1837 	return sock;
1838 out:
1839 	return ERR_PTR(err);
1840 }
1841 
1842 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1843 				      struct socket *sock)
1844 {
1845 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1846 									xprt);
1847 
1848 	if (!transport->inet) {
1849 		struct sock *sk = sock->sk;
1850 
1851 		write_lock_bh(&sk->sk_callback_lock);
1852 
1853 		xs_save_old_callbacks(transport, sk);
1854 
1855 		sk->sk_user_data = xprt;
1856 		sk->sk_data_ready = xs_local_data_ready;
1857 		sk->sk_write_space = xs_udp_write_space;
1858 		sk->sk_error_report = xs_error_report;
1859 		sk->sk_allocation = GFP_ATOMIC;
1860 
1861 		xprt_clear_connected(xprt);
1862 
1863 		/* Reset to new socket */
1864 		transport->sock = sock;
1865 		transport->inet = sk;
1866 
1867 		write_unlock_bh(&sk->sk_callback_lock);
1868 	}
1869 
1870 	/* Tell the socket layer to start connecting... */
1871 	xprt->stat.connect_count++;
1872 	xprt->stat.connect_start = jiffies;
1873 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1874 }
1875 
1876 /**
1877  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1878  * @xprt: RPC transport to connect
1879  * @transport: socket transport to connect
1880  * @create_sock: function to create a socket of the correct type
1881  *
1882  * Invoked by a work queue tasklet.
1883  */
1884 static void xs_local_setup_socket(struct work_struct *work)
1885 {
1886 	struct sock_xprt *transport =
1887 		container_of(work, struct sock_xprt, connect_worker.work);
1888 	struct rpc_xprt *xprt = &transport->xprt;
1889 	struct socket *sock;
1890 	int status = -EIO;
1891 
1892 	if (xprt->shutdown)
1893 		goto out;
1894 
1895 	current->flags |= PF_FSTRANS;
1896 
1897 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1898 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1899 					SOCK_STREAM, 0, &sock, 1);
1900 	if (status < 0) {
1901 		dprintk("RPC:       can't create AF_LOCAL "
1902 			"transport socket (%d).\n", -status);
1903 		goto out;
1904 	}
1905 	xs_reclassify_socketu(sock);
1906 
1907 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1908 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1909 
1910 	status = xs_local_finish_connecting(xprt, sock);
1911 	switch (status) {
1912 	case 0:
1913 		dprintk("RPC:       xprt %p connected to %s\n",
1914 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1915 		xprt_set_connected(xprt);
1916 		break;
1917 	case -ENOENT:
1918 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1919 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1920 		break;
1921 	default:
1922 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1923 				__func__, -status,
1924 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1925 	}
1926 
1927 out:
1928 	xprt_clear_connecting(xprt);
1929 	xprt_wake_pending_tasks(xprt, status);
1930 	current->flags &= ~PF_FSTRANS;
1931 }
1932 
1933 #ifdef CONFIG_SUNRPC_SWAP
1934 static void xs_set_memalloc(struct rpc_xprt *xprt)
1935 {
1936 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1937 			xprt);
1938 
1939 	if (xprt->swapper)
1940 		sk_set_memalloc(transport->inet);
1941 }
1942 
1943 /**
1944  * xs_swapper - Tag this transport as being used for swap.
1945  * @xprt: transport to tag
1946  * @enable: enable/disable
1947  *
1948  */
1949 int xs_swapper(struct rpc_xprt *xprt, int enable)
1950 {
1951 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1952 			xprt);
1953 	int err = 0;
1954 
1955 	if (enable) {
1956 		xprt->swapper++;
1957 		xs_set_memalloc(xprt);
1958 	} else if (xprt->swapper) {
1959 		xprt->swapper--;
1960 		sk_clear_memalloc(transport->inet);
1961 	}
1962 
1963 	return err;
1964 }
1965 EXPORT_SYMBOL_GPL(xs_swapper);
1966 #else
1967 static void xs_set_memalloc(struct rpc_xprt *xprt)
1968 {
1969 }
1970 #endif
1971 
1972 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1973 {
1974 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1975 
1976 	if (!transport->inet) {
1977 		struct sock *sk = sock->sk;
1978 
1979 		write_lock_bh(&sk->sk_callback_lock);
1980 
1981 		xs_save_old_callbacks(transport, sk);
1982 
1983 		sk->sk_user_data = xprt;
1984 		sk->sk_data_ready = xs_udp_data_ready;
1985 		sk->sk_write_space = xs_udp_write_space;
1986 		sk->sk_error_report = xs_error_report;
1987 		sk->sk_no_check = UDP_CSUM_NORCV;
1988 		sk->sk_allocation = GFP_ATOMIC;
1989 
1990 		xprt_set_connected(xprt);
1991 
1992 		/* Reset to new socket */
1993 		transport->sock = sock;
1994 		transport->inet = sk;
1995 
1996 		xs_set_memalloc(xprt);
1997 
1998 		write_unlock_bh(&sk->sk_callback_lock);
1999 	}
2000 	xs_udp_do_set_buffer_size(xprt);
2001 }
2002 
2003 static void xs_udp_setup_socket(struct work_struct *work)
2004 {
2005 	struct sock_xprt *transport =
2006 		container_of(work, struct sock_xprt, connect_worker.work);
2007 	struct rpc_xprt *xprt = &transport->xprt;
2008 	struct socket *sock = transport->sock;
2009 	int status = -EIO;
2010 
2011 	if (xprt->shutdown)
2012 		goto out;
2013 
2014 	current->flags |= PF_FSTRANS;
2015 
2016 	/* Start by resetting any existing state */
2017 	xs_reset_transport(transport);
2018 	sock = xs_create_sock(xprt, transport,
2019 			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2020 	if (IS_ERR(sock))
2021 		goto out;
2022 
2023 	dprintk("RPC:       worker connecting xprt %p via %s to "
2024 				"%s (port %s)\n", xprt,
2025 			xprt->address_strings[RPC_DISPLAY_PROTO],
2026 			xprt->address_strings[RPC_DISPLAY_ADDR],
2027 			xprt->address_strings[RPC_DISPLAY_PORT]);
2028 
2029 	xs_udp_finish_connecting(xprt, sock);
2030 	status = 0;
2031 out:
2032 	xprt_clear_connecting(xprt);
2033 	xprt_wake_pending_tasks(xprt, status);
2034 	current->flags &= ~PF_FSTRANS;
2035 }
2036 
2037 /*
2038  * We need to preserve the port number so the reply cache on the server can
2039  * find our cached RPC replies when we get around to reconnecting.
2040  */
2041 static void xs_abort_connection(struct sock_xprt *transport)
2042 {
2043 	int result;
2044 	struct sockaddr any;
2045 
2046 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2047 
2048 	/*
2049 	 * Disconnect the transport socket by doing a connect operation
2050 	 * with AF_UNSPEC.  This should return immediately...
2051 	 */
2052 	memset(&any, 0, sizeof(any));
2053 	any.sa_family = AF_UNSPEC;
2054 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2055 	if (!result)
2056 		xs_sock_mark_closed(&transport->xprt);
2057 	else
2058 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
2059 				result);
2060 }
2061 
2062 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2063 {
2064 	unsigned int state = transport->inet->sk_state;
2065 
2066 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2067 		/* we don't need to abort the connection if the socket
2068 		 * hasn't undergone a shutdown
2069 		 */
2070 		if (transport->inet->sk_shutdown == 0)
2071 			return;
2072 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2073 				__func__, transport->inet->sk_shutdown);
2074 	}
2075 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2076 		/* we don't need to abort the connection if the socket
2077 		 * hasn't undergone a shutdown
2078 		 */
2079 		if (transport->inet->sk_shutdown == 0)
2080 			return;
2081 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2082 				"sk_shutdown set to %d\n",
2083 				__func__, transport->inet->sk_shutdown);
2084 	}
2085 	xs_abort_connection(transport);
2086 }
2087 
2088 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2089 {
2090 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2091 	int ret = -ENOTCONN;
2092 
2093 	if (!transport->inet) {
2094 		struct sock *sk = sock->sk;
2095 
2096 		write_lock_bh(&sk->sk_callback_lock);
2097 
2098 		xs_save_old_callbacks(transport, sk);
2099 
2100 		sk->sk_user_data = xprt;
2101 		sk->sk_data_ready = xs_tcp_data_ready;
2102 		sk->sk_state_change = xs_tcp_state_change;
2103 		sk->sk_write_space = xs_tcp_write_space;
2104 		sk->sk_error_report = xs_error_report;
2105 		sk->sk_allocation = GFP_ATOMIC;
2106 
2107 		/* socket options */
2108 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2109 		sock_reset_flag(sk, SOCK_LINGER);
2110 		tcp_sk(sk)->linger2 = 0;
2111 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2112 
2113 		xprt_clear_connected(xprt);
2114 
2115 		/* Reset to new socket */
2116 		transport->sock = sock;
2117 		transport->inet = sk;
2118 
2119 		write_unlock_bh(&sk->sk_callback_lock);
2120 	}
2121 
2122 	if (!xprt_bound(xprt))
2123 		goto out;
2124 
2125 	xs_set_memalloc(xprt);
2126 
2127 	/* Tell the socket layer to start connecting... */
2128 	xprt->stat.connect_count++;
2129 	xprt->stat.connect_start = jiffies;
2130 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2131 	switch (ret) {
2132 	case 0:
2133 	case -EINPROGRESS:
2134 		/* SYN_SENT! */
2135 		xprt->connect_cookie++;
2136 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2137 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2138 	}
2139 out:
2140 	return ret;
2141 }
2142 
2143 /**
2144  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2145  * @xprt: RPC transport to connect
2146  * @transport: socket transport to connect
2147  * @create_sock: function to create a socket of the correct type
2148  *
2149  * Invoked by a work queue tasklet.
2150  */
2151 static void xs_tcp_setup_socket(struct work_struct *work)
2152 {
2153 	struct sock_xprt *transport =
2154 		container_of(work, struct sock_xprt, connect_worker.work);
2155 	struct socket *sock = transport->sock;
2156 	struct rpc_xprt *xprt = &transport->xprt;
2157 	int status = -EIO;
2158 
2159 	if (xprt->shutdown)
2160 		goto out;
2161 
2162 	current->flags |= PF_FSTRANS;
2163 
2164 	if (!sock) {
2165 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2166 		sock = xs_create_sock(xprt, transport,
2167 				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2168 		if (IS_ERR(sock)) {
2169 			status = PTR_ERR(sock);
2170 			goto out;
2171 		}
2172 	} else {
2173 		int abort_and_exit;
2174 
2175 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2176 				&xprt->state);
2177 		/* "close" the socket, preserving the local port */
2178 		xs_tcp_reuse_connection(transport);
2179 
2180 		if (abort_and_exit)
2181 			goto out_eagain;
2182 	}
2183 
2184 	dprintk("RPC:       worker connecting xprt %p via %s to "
2185 				"%s (port %s)\n", xprt,
2186 			xprt->address_strings[RPC_DISPLAY_PROTO],
2187 			xprt->address_strings[RPC_DISPLAY_ADDR],
2188 			xprt->address_strings[RPC_DISPLAY_PORT]);
2189 
2190 	status = xs_tcp_finish_connecting(xprt, sock);
2191 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2192 			xprt, -status, xprt_connected(xprt),
2193 			sock->sk->sk_state);
2194 	switch (status) {
2195 	default:
2196 		printk("%s: connect returned unhandled error %d\n",
2197 			__func__, status);
2198 	case -EADDRNOTAVAIL:
2199 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2200 		 * and retry
2201 		 */
2202 		set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
2203 		xprt_force_disconnect(xprt);
2204 		break;
2205 	case -ECONNREFUSED:
2206 	case -ECONNRESET:
2207 	case -ENETUNREACH:
2208 		/* retry with existing socket, after a delay */
2209 	case 0:
2210 	case -EINPROGRESS:
2211 	case -EALREADY:
2212 		xprt_clear_connecting(xprt);
2213 		current->flags &= ~PF_FSTRANS;
2214 		return;
2215 	case -EINVAL:
2216 		/* Happens, for instance, if the user specified a link
2217 		 * local IPv6 address without a scope-id.
2218 		 */
2219 		goto out;
2220 	}
2221 out_eagain:
2222 	status = -EAGAIN;
2223 out:
2224 	xprt_clear_connecting(xprt);
2225 	xprt_wake_pending_tasks(xprt, status);
2226 	current->flags &= ~PF_FSTRANS;
2227 }
2228 
2229 /**
2230  * xs_connect - connect a socket to a remote endpoint
2231  * @task: address of RPC task that manages state of connect request
2232  *
2233  * TCP: If the remote end dropped the connection, delay reconnecting.
2234  *
2235  * UDP socket connects are synchronous, but we use a work queue anyway
2236  * to guarantee that even unprivileged user processes can set up a
2237  * socket on a privileged port.
2238  *
2239  * If a UDP socket connect fails, the delay behavior here prevents
2240  * retry floods (hard mounts).
2241  */
2242 static void xs_connect(struct rpc_task *task)
2243 {
2244 	struct rpc_xprt *xprt = task->tk_xprt;
2245 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2246 
2247 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2248 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2249 				"seconds\n",
2250 				xprt, xprt->reestablish_timeout / HZ);
2251 		queue_delayed_work(rpciod_workqueue,
2252 				   &transport->connect_worker,
2253 				   xprt->reestablish_timeout);
2254 		xprt->reestablish_timeout <<= 1;
2255 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2256 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2257 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2258 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2259 	} else {
2260 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2261 		queue_delayed_work(rpciod_workqueue,
2262 				   &transport->connect_worker, 0);
2263 	}
2264 }
2265 
2266 /**
2267  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2268  * @xprt: rpc_xprt struct containing statistics
2269  * @seq: output file
2270  *
2271  */
2272 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2273 {
2274 	long idle_time = 0;
2275 
2276 	if (xprt_connected(xprt))
2277 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2278 
2279 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2280 			"%llu %llu %lu %llu %llu\n",
2281 			xprt->stat.bind_count,
2282 			xprt->stat.connect_count,
2283 			xprt->stat.connect_time,
2284 			idle_time,
2285 			xprt->stat.sends,
2286 			xprt->stat.recvs,
2287 			xprt->stat.bad_xids,
2288 			xprt->stat.req_u,
2289 			xprt->stat.bklog_u,
2290 			xprt->stat.max_slots,
2291 			xprt->stat.sending_u,
2292 			xprt->stat.pending_u);
2293 }
2294 
2295 /**
2296  * xs_udp_print_stats - display UDP socket-specifc stats
2297  * @xprt: rpc_xprt struct containing statistics
2298  * @seq: output file
2299  *
2300  */
2301 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2302 {
2303 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2304 
2305 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2306 			"%lu %llu %llu\n",
2307 			transport->srcport,
2308 			xprt->stat.bind_count,
2309 			xprt->stat.sends,
2310 			xprt->stat.recvs,
2311 			xprt->stat.bad_xids,
2312 			xprt->stat.req_u,
2313 			xprt->stat.bklog_u,
2314 			xprt->stat.max_slots,
2315 			xprt->stat.sending_u,
2316 			xprt->stat.pending_u);
2317 }
2318 
2319 /**
2320  * xs_tcp_print_stats - display TCP socket-specifc stats
2321  * @xprt: rpc_xprt struct containing statistics
2322  * @seq: output file
2323  *
2324  */
2325 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2326 {
2327 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2328 	long idle_time = 0;
2329 
2330 	if (xprt_connected(xprt))
2331 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2332 
2333 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2334 			"%llu %llu %lu %llu %llu\n",
2335 			transport->srcport,
2336 			xprt->stat.bind_count,
2337 			xprt->stat.connect_count,
2338 			xprt->stat.connect_time,
2339 			idle_time,
2340 			xprt->stat.sends,
2341 			xprt->stat.recvs,
2342 			xprt->stat.bad_xids,
2343 			xprt->stat.req_u,
2344 			xprt->stat.bklog_u,
2345 			xprt->stat.max_slots,
2346 			xprt->stat.sending_u,
2347 			xprt->stat.pending_u);
2348 }
2349 
2350 /*
2351  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2352  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2353  * to use the server side send routines.
2354  */
2355 static void *bc_malloc(struct rpc_task *task, size_t size)
2356 {
2357 	struct page *page;
2358 	struct rpc_buffer *buf;
2359 
2360 	BUG_ON(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2361 	page = alloc_page(GFP_KERNEL);
2362 
2363 	if (!page)
2364 		return NULL;
2365 
2366 	buf = page_address(page);
2367 	buf->len = PAGE_SIZE;
2368 
2369 	return buf->data;
2370 }
2371 
2372 /*
2373  * Free the space allocated in the bc_alloc routine
2374  */
2375 static void bc_free(void *buffer)
2376 {
2377 	struct rpc_buffer *buf;
2378 
2379 	if (!buffer)
2380 		return;
2381 
2382 	buf = container_of(buffer, struct rpc_buffer, data);
2383 	free_page((unsigned long)buf);
2384 }
2385 
2386 /*
2387  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2388  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2389  */
2390 static int bc_sendto(struct rpc_rqst *req)
2391 {
2392 	int len;
2393 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2394 	struct rpc_xprt *xprt = req->rq_xprt;
2395 	struct sock_xprt *transport =
2396 				container_of(xprt, struct sock_xprt, xprt);
2397 	struct socket *sock = transport->sock;
2398 	unsigned long headoff;
2399 	unsigned long tailoff;
2400 
2401 	xs_encode_stream_record_marker(xbufp);
2402 
2403 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2404 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2405 	len = svc_send_common(sock, xbufp,
2406 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2407 			      xbufp->tail[0].iov_base, tailoff);
2408 
2409 	if (len != xbufp->len) {
2410 		printk(KERN_NOTICE "Error sending entire callback!\n");
2411 		len = -EAGAIN;
2412 	}
2413 
2414 	return len;
2415 }
2416 
2417 /*
2418  * The send routine. Borrows from svc_send
2419  */
2420 static int bc_send_request(struct rpc_task *task)
2421 {
2422 	struct rpc_rqst *req = task->tk_rqstp;
2423 	struct svc_xprt	*xprt;
2424 	struct svc_sock         *svsk;
2425 	u32                     len;
2426 
2427 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2428 	/*
2429 	 * Get the server socket associated with this callback xprt
2430 	 */
2431 	xprt = req->rq_xprt->bc_xprt;
2432 	svsk = container_of(xprt, struct svc_sock, sk_xprt);
2433 
2434 	/*
2435 	 * Grab the mutex to serialize data as the connection is shared
2436 	 * with the fore channel
2437 	 */
2438 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2439 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2440 		if (!mutex_trylock(&xprt->xpt_mutex))
2441 			return -EAGAIN;
2442 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2443 	}
2444 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2445 		len = -ENOTCONN;
2446 	else
2447 		len = bc_sendto(req);
2448 	mutex_unlock(&xprt->xpt_mutex);
2449 
2450 	if (len > 0)
2451 		len = 0;
2452 
2453 	return len;
2454 }
2455 
2456 /*
2457  * The close routine. Since this is client initiated, we do nothing
2458  */
2459 
2460 static void bc_close(struct rpc_xprt *xprt)
2461 {
2462 }
2463 
2464 /*
2465  * The xprt destroy routine. Again, because this connection is client
2466  * initiated, we do nothing
2467  */
2468 
2469 static void bc_destroy(struct rpc_xprt *xprt)
2470 {
2471 }
2472 
2473 static struct rpc_xprt_ops xs_local_ops = {
2474 	.reserve_xprt		= xprt_reserve_xprt,
2475 	.release_xprt		= xs_tcp_release_xprt,
2476 	.rpcbind		= xs_local_rpcbind,
2477 	.set_port		= xs_local_set_port,
2478 	.connect		= xs_connect,
2479 	.buf_alloc		= rpc_malloc,
2480 	.buf_free		= rpc_free,
2481 	.send_request		= xs_local_send_request,
2482 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2483 	.close			= xs_close,
2484 	.destroy		= xs_destroy,
2485 	.print_stats		= xs_local_print_stats,
2486 };
2487 
2488 static struct rpc_xprt_ops xs_udp_ops = {
2489 	.set_buffer_size	= xs_udp_set_buffer_size,
2490 	.reserve_xprt		= xprt_reserve_xprt_cong,
2491 	.release_xprt		= xprt_release_xprt_cong,
2492 	.rpcbind		= rpcb_getport_async,
2493 	.set_port		= xs_set_port,
2494 	.connect		= xs_connect,
2495 	.buf_alloc		= rpc_malloc,
2496 	.buf_free		= rpc_free,
2497 	.send_request		= xs_udp_send_request,
2498 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2499 	.timer			= xs_udp_timer,
2500 	.release_request	= xprt_release_rqst_cong,
2501 	.close			= xs_close,
2502 	.destroy		= xs_destroy,
2503 	.print_stats		= xs_udp_print_stats,
2504 };
2505 
2506 static struct rpc_xprt_ops xs_tcp_ops = {
2507 	.reserve_xprt		= xprt_reserve_xprt,
2508 	.release_xprt		= xs_tcp_release_xprt,
2509 	.rpcbind		= rpcb_getport_async,
2510 	.set_port		= xs_set_port,
2511 	.connect		= xs_connect,
2512 	.buf_alloc		= rpc_malloc,
2513 	.buf_free		= rpc_free,
2514 	.send_request		= xs_tcp_send_request,
2515 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2516 	.close			= xs_tcp_close,
2517 	.destroy		= xs_destroy,
2518 	.print_stats		= xs_tcp_print_stats,
2519 };
2520 
2521 /*
2522  * The rpc_xprt_ops for the server backchannel
2523  */
2524 
2525 static struct rpc_xprt_ops bc_tcp_ops = {
2526 	.reserve_xprt		= xprt_reserve_xprt,
2527 	.release_xprt		= xprt_release_xprt,
2528 	.rpcbind		= xs_local_rpcbind,
2529 	.buf_alloc		= bc_malloc,
2530 	.buf_free		= bc_free,
2531 	.send_request		= bc_send_request,
2532 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2533 	.close			= bc_close,
2534 	.destroy		= bc_destroy,
2535 	.print_stats		= xs_tcp_print_stats,
2536 };
2537 
2538 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2539 {
2540 	static const struct sockaddr_in sin = {
2541 		.sin_family		= AF_INET,
2542 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2543 	};
2544 	static const struct sockaddr_in6 sin6 = {
2545 		.sin6_family		= AF_INET6,
2546 		.sin6_addr		= IN6ADDR_ANY_INIT,
2547 	};
2548 
2549 	switch (family) {
2550 	case AF_LOCAL:
2551 		break;
2552 	case AF_INET:
2553 		memcpy(sap, &sin, sizeof(sin));
2554 		break;
2555 	case AF_INET6:
2556 		memcpy(sap, &sin6, sizeof(sin6));
2557 		break;
2558 	default:
2559 		dprintk("RPC:       %s: Bad address family\n", __func__);
2560 		return -EAFNOSUPPORT;
2561 	}
2562 	return 0;
2563 }
2564 
2565 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2566 				      unsigned int slot_table_size,
2567 				      unsigned int max_slot_table_size)
2568 {
2569 	struct rpc_xprt *xprt;
2570 	struct sock_xprt *new;
2571 
2572 	if (args->addrlen > sizeof(xprt->addr)) {
2573 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2574 		return ERR_PTR(-EBADF);
2575 	}
2576 
2577 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2578 			max_slot_table_size);
2579 	if (xprt == NULL) {
2580 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2581 				"rpc_xprt\n");
2582 		return ERR_PTR(-ENOMEM);
2583 	}
2584 
2585 	new = container_of(xprt, struct sock_xprt, xprt);
2586 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2587 	xprt->addrlen = args->addrlen;
2588 	if (args->srcaddr)
2589 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2590 	else {
2591 		int err;
2592 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2593 					(struct sockaddr *)&new->srcaddr);
2594 		if (err != 0) {
2595 			xprt_free(xprt);
2596 			return ERR_PTR(err);
2597 		}
2598 	}
2599 
2600 	return xprt;
2601 }
2602 
2603 static const struct rpc_timeout xs_local_default_timeout = {
2604 	.to_initval = 10 * HZ,
2605 	.to_maxval = 10 * HZ,
2606 	.to_retries = 2,
2607 };
2608 
2609 /**
2610  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2611  * @args: rpc transport creation arguments
2612  *
2613  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2614  */
2615 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2616 {
2617 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2618 	struct sock_xprt *transport;
2619 	struct rpc_xprt *xprt;
2620 	struct rpc_xprt *ret;
2621 
2622 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2623 			xprt_max_tcp_slot_table_entries);
2624 	if (IS_ERR(xprt))
2625 		return xprt;
2626 	transport = container_of(xprt, struct sock_xprt, xprt);
2627 
2628 	xprt->prot = 0;
2629 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2630 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2631 
2632 	xprt->bind_timeout = XS_BIND_TO;
2633 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2634 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2635 
2636 	xprt->ops = &xs_local_ops;
2637 	xprt->timeout = &xs_local_default_timeout;
2638 
2639 	switch (sun->sun_family) {
2640 	case AF_LOCAL:
2641 		if (sun->sun_path[0] != '/') {
2642 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2643 					sun->sun_path);
2644 			ret = ERR_PTR(-EINVAL);
2645 			goto out_err;
2646 		}
2647 		xprt_set_bound(xprt);
2648 		INIT_DELAYED_WORK(&transport->connect_worker,
2649 					xs_local_setup_socket);
2650 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2651 		break;
2652 	default:
2653 		ret = ERR_PTR(-EAFNOSUPPORT);
2654 		goto out_err;
2655 	}
2656 
2657 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2658 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2659 
2660 	if (try_module_get(THIS_MODULE))
2661 		return xprt;
2662 	ret = ERR_PTR(-EINVAL);
2663 out_err:
2664 	xprt_free(xprt);
2665 	return ret;
2666 }
2667 
2668 static const struct rpc_timeout xs_udp_default_timeout = {
2669 	.to_initval = 5 * HZ,
2670 	.to_maxval = 30 * HZ,
2671 	.to_increment = 5 * HZ,
2672 	.to_retries = 5,
2673 };
2674 
2675 /**
2676  * xs_setup_udp - Set up transport to use a UDP socket
2677  * @args: rpc transport creation arguments
2678  *
2679  */
2680 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2681 {
2682 	struct sockaddr *addr = args->dstaddr;
2683 	struct rpc_xprt *xprt;
2684 	struct sock_xprt *transport;
2685 	struct rpc_xprt *ret;
2686 
2687 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2688 			xprt_udp_slot_table_entries);
2689 	if (IS_ERR(xprt))
2690 		return xprt;
2691 	transport = container_of(xprt, struct sock_xprt, xprt);
2692 
2693 	xprt->prot = IPPROTO_UDP;
2694 	xprt->tsh_size = 0;
2695 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2696 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2697 
2698 	xprt->bind_timeout = XS_BIND_TO;
2699 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2700 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2701 
2702 	xprt->ops = &xs_udp_ops;
2703 
2704 	xprt->timeout = &xs_udp_default_timeout;
2705 
2706 	switch (addr->sa_family) {
2707 	case AF_INET:
2708 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2709 			xprt_set_bound(xprt);
2710 
2711 		INIT_DELAYED_WORK(&transport->connect_worker,
2712 					xs_udp_setup_socket);
2713 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2714 		break;
2715 	case AF_INET6:
2716 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2717 			xprt_set_bound(xprt);
2718 
2719 		INIT_DELAYED_WORK(&transport->connect_worker,
2720 					xs_udp_setup_socket);
2721 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2722 		break;
2723 	default:
2724 		ret = ERR_PTR(-EAFNOSUPPORT);
2725 		goto out_err;
2726 	}
2727 
2728 	if (xprt_bound(xprt))
2729 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2730 				xprt->address_strings[RPC_DISPLAY_ADDR],
2731 				xprt->address_strings[RPC_DISPLAY_PORT],
2732 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2733 	else
2734 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2735 				xprt->address_strings[RPC_DISPLAY_ADDR],
2736 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2737 
2738 	if (try_module_get(THIS_MODULE))
2739 		return xprt;
2740 	ret = ERR_PTR(-EINVAL);
2741 out_err:
2742 	xprt_free(xprt);
2743 	return ret;
2744 }
2745 
2746 static const struct rpc_timeout xs_tcp_default_timeout = {
2747 	.to_initval = 60 * HZ,
2748 	.to_maxval = 60 * HZ,
2749 	.to_retries = 2,
2750 };
2751 
2752 /**
2753  * xs_setup_tcp - Set up transport to use a TCP socket
2754  * @args: rpc transport creation arguments
2755  *
2756  */
2757 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2758 {
2759 	struct sockaddr *addr = args->dstaddr;
2760 	struct rpc_xprt *xprt;
2761 	struct sock_xprt *transport;
2762 	struct rpc_xprt *ret;
2763 
2764 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2765 			xprt_max_tcp_slot_table_entries);
2766 	if (IS_ERR(xprt))
2767 		return xprt;
2768 	transport = container_of(xprt, struct sock_xprt, xprt);
2769 
2770 	xprt->prot = IPPROTO_TCP;
2771 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2772 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2773 
2774 	xprt->bind_timeout = XS_BIND_TO;
2775 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2776 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2777 
2778 	xprt->ops = &xs_tcp_ops;
2779 	xprt->timeout = &xs_tcp_default_timeout;
2780 
2781 	switch (addr->sa_family) {
2782 	case AF_INET:
2783 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2784 			xprt_set_bound(xprt);
2785 
2786 		INIT_DELAYED_WORK(&transport->connect_worker,
2787 					xs_tcp_setup_socket);
2788 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2789 		break;
2790 	case AF_INET6:
2791 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2792 			xprt_set_bound(xprt);
2793 
2794 		INIT_DELAYED_WORK(&transport->connect_worker,
2795 					xs_tcp_setup_socket);
2796 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2797 		break;
2798 	default:
2799 		ret = ERR_PTR(-EAFNOSUPPORT);
2800 		goto out_err;
2801 	}
2802 
2803 	if (xprt_bound(xprt))
2804 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2805 				xprt->address_strings[RPC_DISPLAY_ADDR],
2806 				xprt->address_strings[RPC_DISPLAY_PORT],
2807 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2808 	else
2809 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2810 				xprt->address_strings[RPC_DISPLAY_ADDR],
2811 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2812 
2813 
2814 	if (try_module_get(THIS_MODULE))
2815 		return xprt;
2816 	ret = ERR_PTR(-EINVAL);
2817 out_err:
2818 	xprt_free(xprt);
2819 	return ret;
2820 }
2821 
2822 /**
2823  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2824  * @args: rpc transport creation arguments
2825  *
2826  */
2827 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2828 {
2829 	struct sockaddr *addr = args->dstaddr;
2830 	struct rpc_xprt *xprt;
2831 	struct sock_xprt *transport;
2832 	struct svc_sock *bc_sock;
2833 	struct rpc_xprt *ret;
2834 
2835 	if (args->bc_xprt->xpt_bc_xprt) {
2836 		/*
2837 		 * This server connection already has a backchannel
2838 		 * export; we can't create a new one, as we wouldn't be
2839 		 * able to match replies based on xid any more.  So,
2840 		 * reuse the already-existing one:
2841 		 */
2842 		 return args->bc_xprt->xpt_bc_xprt;
2843 	}
2844 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2845 			xprt_tcp_slot_table_entries);
2846 	if (IS_ERR(xprt))
2847 		return xprt;
2848 	transport = container_of(xprt, struct sock_xprt, xprt);
2849 
2850 	xprt->prot = IPPROTO_TCP;
2851 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2852 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2853 	xprt->timeout = &xs_tcp_default_timeout;
2854 
2855 	/* backchannel */
2856 	xprt_set_bound(xprt);
2857 	xprt->bind_timeout = 0;
2858 	xprt->reestablish_timeout = 0;
2859 	xprt->idle_timeout = 0;
2860 
2861 	xprt->ops = &bc_tcp_ops;
2862 
2863 	switch (addr->sa_family) {
2864 	case AF_INET:
2865 		xs_format_peer_addresses(xprt, "tcp",
2866 					 RPCBIND_NETID_TCP);
2867 		break;
2868 	case AF_INET6:
2869 		xs_format_peer_addresses(xprt, "tcp",
2870 				   RPCBIND_NETID_TCP6);
2871 		break;
2872 	default:
2873 		ret = ERR_PTR(-EAFNOSUPPORT);
2874 		goto out_err;
2875 	}
2876 
2877 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2878 			xprt->address_strings[RPC_DISPLAY_ADDR],
2879 			xprt->address_strings[RPC_DISPLAY_PORT],
2880 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2881 
2882 	/*
2883 	 * Once we've associated a backchannel xprt with a connection,
2884 	 * we want to keep it around as long as long as the connection
2885 	 * lasts, in case we need to start using it for a backchannel
2886 	 * again; this reference won't be dropped until bc_xprt is
2887 	 * destroyed.
2888 	 */
2889 	xprt_get(xprt);
2890 	args->bc_xprt->xpt_bc_xprt = xprt;
2891 	xprt->bc_xprt = args->bc_xprt;
2892 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2893 	transport->sock = bc_sock->sk_sock;
2894 	transport->inet = bc_sock->sk_sk;
2895 
2896 	/*
2897 	 * Since we don't want connections for the backchannel, we set
2898 	 * the xprt status to connected
2899 	 */
2900 	xprt_set_connected(xprt);
2901 
2902 
2903 	if (try_module_get(THIS_MODULE))
2904 		return xprt;
2905 	xprt_put(xprt);
2906 	ret = ERR_PTR(-EINVAL);
2907 out_err:
2908 	xprt_free(xprt);
2909 	return ret;
2910 }
2911 
2912 static struct xprt_class	xs_local_transport = {
2913 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2914 	.name		= "named UNIX socket",
2915 	.owner		= THIS_MODULE,
2916 	.ident		= XPRT_TRANSPORT_LOCAL,
2917 	.setup		= xs_setup_local,
2918 };
2919 
2920 static struct xprt_class	xs_udp_transport = {
2921 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2922 	.name		= "udp",
2923 	.owner		= THIS_MODULE,
2924 	.ident		= XPRT_TRANSPORT_UDP,
2925 	.setup		= xs_setup_udp,
2926 };
2927 
2928 static struct xprt_class	xs_tcp_transport = {
2929 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2930 	.name		= "tcp",
2931 	.owner		= THIS_MODULE,
2932 	.ident		= XPRT_TRANSPORT_TCP,
2933 	.setup		= xs_setup_tcp,
2934 };
2935 
2936 static struct xprt_class	xs_bc_tcp_transport = {
2937 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2938 	.name		= "tcp NFSv4.1 backchannel",
2939 	.owner		= THIS_MODULE,
2940 	.ident		= XPRT_TRANSPORT_BC_TCP,
2941 	.setup		= xs_setup_bc_tcp,
2942 };
2943 
2944 /**
2945  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2946  *
2947  */
2948 int init_socket_xprt(void)
2949 {
2950 #ifdef RPC_DEBUG
2951 	if (!sunrpc_table_header)
2952 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2953 #endif
2954 
2955 	xprt_register_transport(&xs_local_transport);
2956 	xprt_register_transport(&xs_udp_transport);
2957 	xprt_register_transport(&xs_tcp_transport);
2958 	xprt_register_transport(&xs_bc_tcp_transport);
2959 
2960 	return 0;
2961 }
2962 
2963 /**
2964  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2965  *
2966  */
2967 void cleanup_socket_xprt(void)
2968 {
2969 #ifdef RPC_DEBUG
2970 	if (sunrpc_table_header) {
2971 		unregister_sysctl_table(sunrpc_table_header);
2972 		sunrpc_table_header = NULL;
2973 	}
2974 #endif
2975 
2976 	xprt_unregister_transport(&xs_local_transport);
2977 	xprt_unregister_transport(&xs_udp_transport);
2978 	xprt_unregister_transport(&xs_tcp_transport);
2979 	xprt_unregister_transport(&xs_bc_tcp_transport);
2980 }
2981 
2982 static int param_set_uint_minmax(const char *val,
2983 		const struct kernel_param *kp,
2984 		unsigned int min, unsigned int max)
2985 {
2986 	unsigned long num;
2987 	int ret;
2988 
2989 	if (!val)
2990 		return -EINVAL;
2991 	ret = strict_strtoul(val, 0, &num);
2992 	if (ret == -EINVAL || num < min || num > max)
2993 		return -EINVAL;
2994 	*((unsigned int *)kp->arg) = num;
2995 	return 0;
2996 }
2997 
2998 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2999 {
3000 	return param_set_uint_minmax(val, kp,
3001 			RPC_MIN_RESVPORT,
3002 			RPC_MAX_RESVPORT);
3003 }
3004 
3005 static struct kernel_param_ops param_ops_portnr = {
3006 	.set = param_set_portnr,
3007 	.get = param_get_uint,
3008 };
3009 
3010 #define param_check_portnr(name, p) \
3011 	__param_check(name, p, unsigned int);
3012 
3013 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3014 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3015 
3016 static int param_set_slot_table_size(const char *val,
3017 				     const struct kernel_param *kp)
3018 {
3019 	return param_set_uint_minmax(val, kp,
3020 			RPC_MIN_SLOT_TABLE,
3021 			RPC_MAX_SLOT_TABLE);
3022 }
3023 
3024 static struct kernel_param_ops param_ops_slot_table_size = {
3025 	.set = param_set_slot_table_size,
3026 	.get = param_get_uint,
3027 };
3028 
3029 #define param_check_slot_table_size(name, p) \
3030 	__param_check(name, p, unsigned int);
3031 
3032 static int param_set_max_slot_table_size(const char *val,
3033 				     const struct kernel_param *kp)
3034 {
3035 	return param_set_uint_minmax(val, kp,
3036 			RPC_MIN_SLOT_TABLE,
3037 			RPC_MAX_SLOT_TABLE_LIMIT);
3038 }
3039 
3040 static struct kernel_param_ops param_ops_max_slot_table_size = {
3041 	.set = param_set_max_slot_table_size,
3042 	.get = param_get_uint,
3043 };
3044 
3045 #define param_check_max_slot_table_size(name, p) \
3046 	__param_check(name, p, unsigned int);
3047 
3048 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3049 		   slot_table_size, 0644);
3050 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3051 		   max_slot_table_size, 0644);
3052 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3053 		   slot_table_size, 0644);
3054 
3055