xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 1ab142d4)
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 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
57 unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
58 unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
59 
60 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
61 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 	/* Something worked... */
1018 	dst_confirm(skb_dst(skb));
1019 
1020 	xprt_adjust_cwnd(task, copied);
1021 	xprt_complete_rqst(task, copied);
1022 
1023  out_unlock:
1024 	spin_unlock(&xprt->transport_lock);
1025  dropit:
1026 	skb_free_datagram(sk, skb);
1027  out:
1028 	read_unlock_bh(&sk->sk_callback_lock);
1029 }
1030 
1031 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1032 {
1033 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1034 	size_t len, used;
1035 	char *p;
1036 
1037 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1038 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1039 	used = xdr_skb_read_bits(desc, p, len);
1040 	transport->tcp_offset += used;
1041 	if (used != len)
1042 		return;
1043 
1044 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1045 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1046 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1047 	else
1048 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1049 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1050 
1051 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1052 	transport->tcp_offset = 0;
1053 
1054 	/* Sanity check of the record length */
1055 	if (unlikely(transport->tcp_reclen < 8)) {
1056 		dprintk("RPC:       invalid TCP record fragment length\n");
1057 		xprt_force_disconnect(xprt);
1058 		return;
1059 	}
1060 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1061 			transport->tcp_reclen);
1062 }
1063 
1064 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1065 {
1066 	if (transport->tcp_offset == transport->tcp_reclen) {
1067 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1068 		transport->tcp_offset = 0;
1069 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1070 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1071 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1072 			transport->tcp_copied = 0;
1073 		}
1074 	}
1075 }
1076 
1077 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1078 {
1079 	size_t len, used;
1080 	char *p;
1081 
1082 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1083 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1084 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1085 	used = xdr_skb_read_bits(desc, p, len);
1086 	transport->tcp_offset += used;
1087 	if (used != len)
1088 		return;
1089 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1090 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1091 	transport->tcp_copied = 4;
1092 	dprintk("RPC:       reading %s XID %08x\n",
1093 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1094 							      : "request with",
1095 			ntohl(transport->tcp_xid));
1096 	xs_tcp_check_fraghdr(transport);
1097 }
1098 
1099 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1100 				       struct xdr_skb_reader *desc)
1101 {
1102 	size_t len, used;
1103 	u32 offset;
1104 	char *p;
1105 
1106 	/*
1107 	 * We want transport->tcp_offset to be 8 at the end of this routine
1108 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1109 	 * When this function is called for the first time,
1110 	 * transport->tcp_offset is 4 (after having already read the xid).
1111 	 */
1112 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1113 	len = sizeof(transport->tcp_calldir) - offset;
1114 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1115 	p = ((char *) &transport->tcp_calldir) + offset;
1116 	used = xdr_skb_read_bits(desc, p, len);
1117 	transport->tcp_offset += used;
1118 	if (used != len)
1119 		return;
1120 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1121 	/*
1122 	 * We don't yet have the XDR buffer, so we will write the calldir
1123 	 * out after we get the buffer from the 'struct rpc_rqst'
1124 	 */
1125 	switch (ntohl(transport->tcp_calldir)) {
1126 	case RPC_REPLY:
1127 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1128 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1129 		transport->tcp_flags |= TCP_RPC_REPLY;
1130 		break;
1131 	case RPC_CALL:
1132 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1133 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1134 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1135 		break;
1136 	default:
1137 		dprintk("RPC:       invalid request message type\n");
1138 		xprt_force_disconnect(&transport->xprt);
1139 	}
1140 	xs_tcp_check_fraghdr(transport);
1141 }
1142 
1143 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1144 				     struct xdr_skb_reader *desc,
1145 				     struct rpc_rqst *req)
1146 {
1147 	struct sock_xprt *transport =
1148 				container_of(xprt, struct sock_xprt, xprt);
1149 	struct xdr_buf *rcvbuf;
1150 	size_t len;
1151 	ssize_t r;
1152 
1153 	rcvbuf = &req->rq_private_buf;
1154 
1155 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1156 		/*
1157 		 * Save the RPC direction in the XDR buffer
1158 		 */
1159 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1160 			&transport->tcp_calldir,
1161 			sizeof(transport->tcp_calldir));
1162 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1163 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1164 	}
1165 
1166 	len = desc->count;
1167 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1168 		struct xdr_skb_reader my_desc;
1169 
1170 		len = transport->tcp_reclen - transport->tcp_offset;
1171 		memcpy(&my_desc, desc, sizeof(my_desc));
1172 		my_desc.count = len;
1173 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1174 					  &my_desc, xdr_skb_read_bits);
1175 		desc->count -= r;
1176 		desc->offset += r;
1177 	} else
1178 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1179 					  desc, xdr_skb_read_bits);
1180 
1181 	if (r > 0) {
1182 		transport->tcp_copied += r;
1183 		transport->tcp_offset += r;
1184 	}
1185 	if (r != len) {
1186 		/* Error when copying to the receive buffer,
1187 		 * usually because we weren't able to allocate
1188 		 * additional buffer pages. All we can do now
1189 		 * is turn off TCP_RCV_COPY_DATA, so the request
1190 		 * will not receive any additional updates,
1191 		 * and time out.
1192 		 * Any remaining data from this record will
1193 		 * be discarded.
1194 		 */
1195 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1196 		dprintk("RPC:       XID %08x truncated request\n",
1197 				ntohl(transport->tcp_xid));
1198 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1199 				"tcp_offset = %u, tcp_reclen = %u\n",
1200 				xprt, transport->tcp_copied,
1201 				transport->tcp_offset, transport->tcp_reclen);
1202 		return;
1203 	}
1204 
1205 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1206 			ntohl(transport->tcp_xid), r);
1207 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1208 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1209 			transport->tcp_offset, transport->tcp_reclen);
1210 
1211 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1212 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1213 	else if (transport->tcp_offset == transport->tcp_reclen) {
1214 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1215 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1216 	}
1217 }
1218 
1219 /*
1220  * Finds the request corresponding to the RPC xid and invokes the common
1221  * tcp read code to read the data.
1222  */
1223 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1224 				    struct xdr_skb_reader *desc)
1225 {
1226 	struct sock_xprt *transport =
1227 				container_of(xprt, struct sock_xprt, xprt);
1228 	struct rpc_rqst *req;
1229 
1230 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1231 
1232 	/* Find and lock the request corresponding to this xid */
1233 	spin_lock(&xprt->transport_lock);
1234 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1235 	if (!req) {
1236 		dprintk("RPC:       XID %08x request not found!\n",
1237 				ntohl(transport->tcp_xid));
1238 		spin_unlock(&xprt->transport_lock);
1239 		return -1;
1240 	}
1241 
1242 	xs_tcp_read_common(xprt, desc, req);
1243 
1244 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1245 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1246 
1247 	spin_unlock(&xprt->transport_lock);
1248 	return 0;
1249 }
1250 
1251 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1252 /*
1253  * Obtains an rpc_rqst previously allocated and invokes the common
1254  * tcp read code to read the data.  The result is placed in the callback
1255  * queue.
1256  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1257  * connection and return -1.
1258  */
1259 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1260 				       struct xdr_skb_reader *desc)
1261 {
1262 	struct sock_xprt *transport =
1263 				container_of(xprt, struct sock_xprt, xprt);
1264 	struct rpc_rqst *req;
1265 
1266 	req = xprt_alloc_bc_request(xprt);
1267 	if (req == NULL) {
1268 		printk(KERN_WARNING "Callback slot table overflowed\n");
1269 		xprt_force_disconnect(xprt);
1270 		return -1;
1271 	}
1272 
1273 	req->rq_xid = transport->tcp_xid;
1274 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1275 	xs_tcp_read_common(xprt, desc, req);
1276 
1277 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1278 		struct svc_serv *bc_serv = xprt->bc_serv;
1279 
1280 		/*
1281 		 * Add callback request to callback list.  The callback
1282 		 * service sleeps on the sv_cb_waitq waiting for new
1283 		 * requests.  Wake it up after adding enqueing the
1284 		 * request.
1285 		 */
1286 		dprintk("RPC:       add callback request to list\n");
1287 		spin_lock(&bc_serv->sv_cb_lock);
1288 		list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1289 		spin_unlock(&bc_serv->sv_cb_lock);
1290 		wake_up(&bc_serv->sv_cb_waitq);
1291 	}
1292 
1293 	req->rq_private_buf.len = transport->tcp_copied;
1294 
1295 	return 0;
1296 }
1297 
1298 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1299 					struct xdr_skb_reader *desc)
1300 {
1301 	struct sock_xprt *transport =
1302 				container_of(xprt, struct sock_xprt, xprt);
1303 
1304 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1305 		xs_tcp_read_reply(xprt, desc) :
1306 		xs_tcp_read_callback(xprt, desc);
1307 }
1308 #else
1309 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1310 					struct xdr_skb_reader *desc)
1311 {
1312 	return xs_tcp_read_reply(xprt, desc);
1313 }
1314 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1315 
1316 /*
1317  * Read data off the transport.  This can be either an RPC_CALL or an
1318  * RPC_REPLY.  Relay the processing to helper functions.
1319  */
1320 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1321 				    struct xdr_skb_reader *desc)
1322 {
1323 	struct sock_xprt *transport =
1324 				container_of(xprt, struct sock_xprt, xprt);
1325 
1326 	if (_xs_tcp_read_data(xprt, desc) == 0)
1327 		xs_tcp_check_fraghdr(transport);
1328 	else {
1329 		/*
1330 		 * The transport_lock protects the request handling.
1331 		 * There's no need to hold it to update the tcp_flags.
1332 		 */
1333 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1334 	}
1335 }
1336 
1337 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1338 {
1339 	size_t len;
1340 
1341 	len = transport->tcp_reclen - transport->tcp_offset;
1342 	if (len > desc->count)
1343 		len = desc->count;
1344 	desc->count -= len;
1345 	desc->offset += len;
1346 	transport->tcp_offset += len;
1347 	dprintk("RPC:       discarded %Zu bytes\n", len);
1348 	xs_tcp_check_fraghdr(transport);
1349 }
1350 
1351 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1352 {
1353 	struct rpc_xprt *xprt = rd_desc->arg.data;
1354 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1355 	struct xdr_skb_reader desc = {
1356 		.skb	= skb,
1357 		.offset	= offset,
1358 		.count	= len,
1359 	};
1360 
1361 	dprintk("RPC:       xs_tcp_data_recv started\n");
1362 	do {
1363 		/* Read in a new fragment marker if necessary */
1364 		/* Can we ever really expect to get completely empty fragments? */
1365 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1366 			xs_tcp_read_fraghdr(xprt, &desc);
1367 			continue;
1368 		}
1369 		/* Read in the xid if necessary */
1370 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1371 			xs_tcp_read_xid(transport, &desc);
1372 			continue;
1373 		}
1374 		/* Read in the call/reply flag */
1375 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1376 			xs_tcp_read_calldir(transport, &desc);
1377 			continue;
1378 		}
1379 		/* Read in the request data */
1380 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1381 			xs_tcp_read_data(xprt, &desc);
1382 			continue;
1383 		}
1384 		/* Skip over any trailing bytes on short reads */
1385 		xs_tcp_read_discard(transport, &desc);
1386 	} while (desc.count);
1387 	dprintk("RPC:       xs_tcp_data_recv done\n");
1388 	return len - desc.count;
1389 }
1390 
1391 /**
1392  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1393  * @sk: socket with data to read
1394  * @bytes: how much data to read
1395  *
1396  */
1397 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1398 {
1399 	struct rpc_xprt *xprt;
1400 	read_descriptor_t rd_desc;
1401 	int read;
1402 
1403 	dprintk("RPC:       xs_tcp_data_ready...\n");
1404 
1405 	read_lock_bh(&sk->sk_callback_lock);
1406 	if (!(xprt = xprt_from_sock(sk)))
1407 		goto out;
1408 	if (xprt->shutdown)
1409 		goto out;
1410 
1411 	/* Any data means we had a useful conversation, so
1412 	 * the we don't need to delay the next reconnect
1413 	 */
1414 	if (xprt->reestablish_timeout)
1415 		xprt->reestablish_timeout = 0;
1416 
1417 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1418 	rd_desc.arg.data = xprt;
1419 	do {
1420 		rd_desc.count = 65536;
1421 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1422 	} while (read > 0);
1423 out:
1424 	read_unlock_bh(&sk->sk_callback_lock);
1425 }
1426 
1427 /*
1428  * Do the equivalent of linger/linger2 handling for dealing with
1429  * broken servers that don't close the socket in a timely
1430  * fashion
1431  */
1432 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1433 		unsigned long timeout)
1434 {
1435 	struct sock_xprt *transport;
1436 
1437 	if (xprt_test_and_set_connecting(xprt))
1438 		return;
1439 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1440 	transport = container_of(xprt, struct sock_xprt, xprt);
1441 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1442 			   timeout);
1443 }
1444 
1445 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1446 {
1447 	struct sock_xprt *transport;
1448 
1449 	transport = container_of(xprt, struct sock_xprt, xprt);
1450 
1451 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1452 	    !cancel_delayed_work(&transport->connect_worker))
1453 		return;
1454 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1455 	xprt_clear_connecting(xprt);
1456 }
1457 
1458 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1459 {
1460 	smp_mb__before_clear_bit();
1461 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1462 	clear_bit(XPRT_CLOSING, &xprt->state);
1463 	smp_mb__after_clear_bit();
1464 	/* Mark transport as closed and wake up all pending tasks */
1465 	xprt_disconnect_done(xprt);
1466 }
1467 
1468 /**
1469  * xs_tcp_state_change - callback to handle TCP socket state changes
1470  * @sk: socket whose state has changed
1471  *
1472  */
1473 static void xs_tcp_state_change(struct sock *sk)
1474 {
1475 	struct rpc_xprt *xprt;
1476 
1477 	read_lock_bh(&sk->sk_callback_lock);
1478 	if (!(xprt = xprt_from_sock(sk)))
1479 		goto out;
1480 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1481 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1482 			sk->sk_state, xprt_connected(xprt),
1483 			sock_flag(sk, SOCK_DEAD),
1484 			sock_flag(sk, SOCK_ZAPPED),
1485 			sk->sk_shutdown);
1486 
1487 	switch (sk->sk_state) {
1488 	case TCP_ESTABLISHED:
1489 		spin_lock(&xprt->transport_lock);
1490 		if (!xprt_test_and_set_connected(xprt)) {
1491 			struct sock_xprt *transport = container_of(xprt,
1492 					struct sock_xprt, xprt);
1493 
1494 			/* Reset TCP record info */
1495 			transport->tcp_offset = 0;
1496 			transport->tcp_reclen = 0;
1497 			transport->tcp_copied = 0;
1498 			transport->tcp_flags =
1499 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1500 
1501 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1502 		}
1503 		spin_unlock(&xprt->transport_lock);
1504 		break;
1505 	case TCP_FIN_WAIT1:
1506 		/* The client initiated a shutdown of the socket */
1507 		xprt->connect_cookie++;
1508 		xprt->reestablish_timeout = 0;
1509 		set_bit(XPRT_CLOSING, &xprt->state);
1510 		smp_mb__before_clear_bit();
1511 		clear_bit(XPRT_CONNECTED, &xprt->state);
1512 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1513 		smp_mb__after_clear_bit();
1514 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1515 		break;
1516 	case TCP_CLOSE_WAIT:
1517 		/* The server initiated a shutdown of the socket */
1518 		xprt_force_disconnect(xprt);
1519 		xprt->connect_cookie++;
1520 	case TCP_CLOSING:
1521 		/*
1522 		 * If the server closed down the connection, make sure that
1523 		 * we back off before reconnecting
1524 		 */
1525 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1526 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1527 		break;
1528 	case TCP_LAST_ACK:
1529 		set_bit(XPRT_CLOSING, &xprt->state);
1530 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1531 		smp_mb__before_clear_bit();
1532 		clear_bit(XPRT_CONNECTED, &xprt->state);
1533 		smp_mb__after_clear_bit();
1534 		break;
1535 	case TCP_CLOSE:
1536 		xs_tcp_cancel_linger_timeout(xprt);
1537 		xs_sock_mark_closed(xprt);
1538 	}
1539  out:
1540 	read_unlock_bh(&sk->sk_callback_lock);
1541 }
1542 
1543 /**
1544  * xs_error_report - callback mainly for catching socket errors
1545  * @sk: socket
1546  */
1547 static void xs_error_report(struct sock *sk)
1548 {
1549 	struct rpc_xprt *xprt;
1550 
1551 	read_lock_bh(&sk->sk_callback_lock);
1552 	if (!(xprt = xprt_from_sock(sk)))
1553 		goto out;
1554 	dprintk("RPC:       %s client %p...\n"
1555 			"RPC:       error %d\n",
1556 			__func__, xprt, sk->sk_err);
1557 	xprt_wake_pending_tasks(xprt, -EAGAIN);
1558 out:
1559 	read_unlock_bh(&sk->sk_callback_lock);
1560 }
1561 
1562 static void xs_write_space(struct sock *sk)
1563 {
1564 	struct socket *sock;
1565 	struct rpc_xprt *xprt;
1566 
1567 	if (unlikely(!(sock = sk->sk_socket)))
1568 		return;
1569 	clear_bit(SOCK_NOSPACE, &sock->flags);
1570 
1571 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1572 		return;
1573 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1574 		return;
1575 
1576 	xprt_write_space(xprt);
1577 }
1578 
1579 /**
1580  * xs_udp_write_space - callback invoked when socket buffer space
1581  *                             becomes available
1582  * @sk: socket whose state has changed
1583  *
1584  * Called when more output buffer space is available for this socket.
1585  * We try not to wake our writers until they can make "significant"
1586  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1587  * with a bunch of small requests.
1588  */
1589 static void xs_udp_write_space(struct sock *sk)
1590 {
1591 	read_lock_bh(&sk->sk_callback_lock);
1592 
1593 	/* from net/core/sock.c:sock_def_write_space */
1594 	if (sock_writeable(sk))
1595 		xs_write_space(sk);
1596 
1597 	read_unlock_bh(&sk->sk_callback_lock);
1598 }
1599 
1600 /**
1601  * xs_tcp_write_space - callback invoked when socket buffer space
1602  *                             becomes available
1603  * @sk: socket whose state has changed
1604  *
1605  * Called when more output buffer space is available for this socket.
1606  * We try not to wake our writers until they can make "significant"
1607  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1608  * with a bunch of small requests.
1609  */
1610 static void xs_tcp_write_space(struct sock *sk)
1611 {
1612 	read_lock_bh(&sk->sk_callback_lock);
1613 
1614 	/* from net/core/stream.c:sk_stream_write_space */
1615 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
1616 		xs_write_space(sk);
1617 
1618 	read_unlock_bh(&sk->sk_callback_lock);
1619 }
1620 
1621 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1622 {
1623 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1624 	struct sock *sk = transport->inet;
1625 
1626 	if (transport->rcvsize) {
1627 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1628 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1629 	}
1630 	if (transport->sndsize) {
1631 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1632 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1633 		sk->sk_write_space(sk);
1634 	}
1635 }
1636 
1637 /**
1638  * xs_udp_set_buffer_size - set send and receive limits
1639  * @xprt: generic transport
1640  * @sndsize: requested size of send buffer, in bytes
1641  * @rcvsize: requested size of receive buffer, in bytes
1642  *
1643  * Set socket send and receive buffer size limits.
1644  */
1645 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1646 {
1647 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1648 
1649 	transport->sndsize = 0;
1650 	if (sndsize)
1651 		transport->sndsize = sndsize + 1024;
1652 	transport->rcvsize = 0;
1653 	if (rcvsize)
1654 		transport->rcvsize = rcvsize + 1024;
1655 
1656 	xs_udp_do_set_buffer_size(xprt);
1657 }
1658 
1659 /**
1660  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1661  * @task: task that timed out
1662  *
1663  * Adjust the congestion window after a retransmit timeout has occurred.
1664  */
1665 static void xs_udp_timer(struct rpc_task *task)
1666 {
1667 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1668 }
1669 
1670 static unsigned short xs_get_random_port(void)
1671 {
1672 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1673 	unsigned short rand = (unsigned short) net_random() % range;
1674 	return rand + xprt_min_resvport;
1675 }
1676 
1677 /**
1678  * xs_set_port - reset the port number in the remote endpoint address
1679  * @xprt: generic transport
1680  * @port: new port number
1681  *
1682  */
1683 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1684 {
1685 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1686 
1687 	rpc_set_port(xs_addr(xprt), port);
1688 	xs_update_peer_port(xprt);
1689 }
1690 
1691 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1692 {
1693 	unsigned short port = transport->srcport;
1694 
1695 	if (port == 0 && transport->xprt.resvport)
1696 		port = xs_get_random_port();
1697 	return port;
1698 }
1699 
1700 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1701 {
1702 	if (transport->srcport != 0)
1703 		transport->srcport = 0;
1704 	if (!transport->xprt.resvport)
1705 		return 0;
1706 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1707 		return xprt_max_resvport;
1708 	return --port;
1709 }
1710 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1711 {
1712 	struct sockaddr_storage myaddr;
1713 	int err, nloop = 0;
1714 	unsigned short port = xs_get_srcport(transport);
1715 	unsigned short last;
1716 
1717 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1718 	do {
1719 		rpc_set_port((struct sockaddr *)&myaddr, port);
1720 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1721 				transport->xprt.addrlen);
1722 		if (port == 0)
1723 			break;
1724 		if (err == 0) {
1725 			transport->srcport = port;
1726 			break;
1727 		}
1728 		last = port;
1729 		port = xs_next_srcport(transport, port);
1730 		if (port > last)
1731 			nloop++;
1732 	} while (err == -EADDRINUSE && nloop != 2);
1733 
1734 	if (myaddr.ss_family == AF_INET)
1735 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1736 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1737 				port, err ? "failed" : "ok", err);
1738 	else
1739 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1740 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1741 				port, err ? "failed" : "ok", err);
1742 	return err;
1743 }
1744 
1745 /*
1746  * We don't support autobind on AF_LOCAL sockets
1747  */
1748 static void xs_local_rpcbind(struct rpc_task *task)
1749 {
1750 	xprt_set_bound(task->tk_xprt);
1751 }
1752 
1753 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1754 {
1755 }
1756 
1757 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1758 static struct lock_class_key xs_key[2];
1759 static struct lock_class_key xs_slock_key[2];
1760 
1761 static inline void xs_reclassify_socketu(struct socket *sock)
1762 {
1763 	struct sock *sk = sock->sk;
1764 
1765 	BUG_ON(sock_owned_by_user(sk));
1766 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1767 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1768 }
1769 
1770 static inline void xs_reclassify_socket4(struct socket *sock)
1771 {
1772 	struct sock *sk = sock->sk;
1773 
1774 	BUG_ON(sock_owned_by_user(sk));
1775 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1776 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1777 }
1778 
1779 static inline void xs_reclassify_socket6(struct socket *sock)
1780 {
1781 	struct sock *sk = sock->sk;
1782 
1783 	BUG_ON(sock_owned_by_user(sk));
1784 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1785 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1786 }
1787 
1788 static inline void xs_reclassify_socket(int family, struct socket *sock)
1789 {
1790 	switch (family) {
1791 	case AF_LOCAL:
1792 		xs_reclassify_socketu(sock);
1793 		break;
1794 	case AF_INET:
1795 		xs_reclassify_socket4(sock);
1796 		break;
1797 	case AF_INET6:
1798 		xs_reclassify_socket6(sock);
1799 		break;
1800 	}
1801 }
1802 #else
1803 static inline void xs_reclassify_socketu(struct socket *sock)
1804 {
1805 }
1806 
1807 static inline void xs_reclassify_socket4(struct socket *sock)
1808 {
1809 }
1810 
1811 static inline void xs_reclassify_socket6(struct socket *sock)
1812 {
1813 }
1814 
1815 static inline void xs_reclassify_socket(int family, struct socket *sock)
1816 {
1817 }
1818 #endif
1819 
1820 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1821 		struct sock_xprt *transport, int family, int type, int protocol)
1822 {
1823 	struct socket *sock;
1824 	int err;
1825 
1826 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1827 	if (err < 0) {
1828 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1829 				protocol, -err);
1830 		goto out;
1831 	}
1832 	xs_reclassify_socket(family, sock);
1833 
1834 	err = xs_bind(transport, sock);
1835 	if (err) {
1836 		sock_release(sock);
1837 		goto out;
1838 	}
1839 
1840 	return sock;
1841 out:
1842 	return ERR_PTR(err);
1843 }
1844 
1845 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1846 				      struct socket *sock)
1847 {
1848 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1849 									xprt);
1850 
1851 	if (!transport->inet) {
1852 		struct sock *sk = sock->sk;
1853 
1854 		write_lock_bh(&sk->sk_callback_lock);
1855 
1856 		xs_save_old_callbacks(transport, sk);
1857 
1858 		sk->sk_user_data = xprt;
1859 		sk->sk_data_ready = xs_local_data_ready;
1860 		sk->sk_write_space = xs_udp_write_space;
1861 		sk->sk_error_report = xs_error_report;
1862 		sk->sk_allocation = GFP_ATOMIC;
1863 
1864 		xprt_clear_connected(xprt);
1865 
1866 		/* Reset to new socket */
1867 		transport->sock = sock;
1868 		transport->inet = sk;
1869 
1870 		write_unlock_bh(&sk->sk_callback_lock);
1871 	}
1872 
1873 	/* Tell the socket layer to start connecting... */
1874 	xprt->stat.connect_count++;
1875 	xprt->stat.connect_start = jiffies;
1876 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1877 }
1878 
1879 /**
1880  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1881  * @xprt: RPC transport to connect
1882  * @transport: socket transport to connect
1883  * @create_sock: function to create a socket of the correct type
1884  *
1885  * Invoked by a work queue tasklet.
1886  */
1887 static void xs_local_setup_socket(struct work_struct *work)
1888 {
1889 	struct sock_xprt *transport =
1890 		container_of(work, struct sock_xprt, connect_worker.work);
1891 	struct rpc_xprt *xprt = &transport->xprt;
1892 	struct socket *sock;
1893 	int status = -EIO;
1894 
1895 	if (xprt->shutdown)
1896 		goto out;
1897 
1898 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1899 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1900 					SOCK_STREAM, 0, &sock, 1);
1901 	if (status < 0) {
1902 		dprintk("RPC:       can't create AF_LOCAL "
1903 			"transport socket (%d).\n", -status);
1904 		goto out;
1905 	}
1906 	xs_reclassify_socketu(sock);
1907 
1908 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1909 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1910 
1911 	status = xs_local_finish_connecting(xprt, sock);
1912 	switch (status) {
1913 	case 0:
1914 		dprintk("RPC:       xprt %p connected to %s\n",
1915 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1916 		xprt_set_connected(xprt);
1917 		break;
1918 	case -ENOENT:
1919 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1920 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1921 		break;
1922 	default:
1923 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1924 				__func__, -status,
1925 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1926 	}
1927 
1928 out:
1929 	xprt_clear_connecting(xprt);
1930 	xprt_wake_pending_tasks(xprt, status);
1931 }
1932 
1933 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1934 {
1935 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1936 
1937 	if (!transport->inet) {
1938 		struct sock *sk = sock->sk;
1939 
1940 		write_lock_bh(&sk->sk_callback_lock);
1941 
1942 		xs_save_old_callbacks(transport, sk);
1943 
1944 		sk->sk_user_data = xprt;
1945 		sk->sk_data_ready = xs_udp_data_ready;
1946 		sk->sk_write_space = xs_udp_write_space;
1947 		sk->sk_error_report = xs_error_report;
1948 		sk->sk_no_check = UDP_CSUM_NORCV;
1949 		sk->sk_allocation = GFP_ATOMIC;
1950 
1951 		xprt_set_connected(xprt);
1952 
1953 		/* Reset to new socket */
1954 		transport->sock = sock;
1955 		transport->inet = sk;
1956 
1957 		write_unlock_bh(&sk->sk_callback_lock);
1958 	}
1959 	xs_udp_do_set_buffer_size(xprt);
1960 }
1961 
1962 static void xs_udp_setup_socket(struct work_struct *work)
1963 {
1964 	struct sock_xprt *transport =
1965 		container_of(work, struct sock_xprt, connect_worker.work);
1966 	struct rpc_xprt *xprt = &transport->xprt;
1967 	struct socket *sock = transport->sock;
1968 	int status = -EIO;
1969 
1970 	if (xprt->shutdown)
1971 		goto out;
1972 
1973 	/* Start by resetting any existing state */
1974 	xs_reset_transport(transport);
1975 	sock = xs_create_sock(xprt, transport,
1976 			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
1977 	if (IS_ERR(sock))
1978 		goto out;
1979 
1980 	dprintk("RPC:       worker connecting xprt %p via %s to "
1981 				"%s (port %s)\n", xprt,
1982 			xprt->address_strings[RPC_DISPLAY_PROTO],
1983 			xprt->address_strings[RPC_DISPLAY_ADDR],
1984 			xprt->address_strings[RPC_DISPLAY_PORT]);
1985 
1986 	xs_udp_finish_connecting(xprt, sock);
1987 	status = 0;
1988 out:
1989 	xprt_clear_connecting(xprt);
1990 	xprt_wake_pending_tasks(xprt, status);
1991 }
1992 
1993 /*
1994  * We need to preserve the port number so the reply cache on the server can
1995  * find our cached RPC replies when we get around to reconnecting.
1996  */
1997 static void xs_abort_connection(struct sock_xprt *transport)
1998 {
1999 	int result;
2000 	struct sockaddr any;
2001 
2002 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2003 
2004 	/*
2005 	 * Disconnect the transport socket by doing a connect operation
2006 	 * with AF_UNSPEC.  This should return immediately...
2007 	 */
2008 	memset(&any, 0, sizeof(any));
2009 	any.sa_family = AF_UNSPEC;
2010 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2011 	if (!result)
2012 		xs_sock_mark_closed(&transport->xprt);
2013 	else
2014 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
2015 				result);
2016 }
2017 
2018 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2019 {
2020 	unsigned int state = transport->inet->sk_state;
2021 
2022 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2023 		/* we don't need to abort the connection if the socket
2024 		 * hasn't undergone a shutdown
2025 		 */
2026 		if (transport->inet->sk_shutdown == 0)
2027 			return;
2028 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2029 				__func__, transport->inet->sk_shutdown);
2030 	}
2031 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2032 		/* we don't need to abort the connection if the socket
2033 		 * hasn't undergone a shutdown
2034 		 */
2035 		if (transport->inet->sk_shutdown == 0)
2036 			return;
2037 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2038 				"sk_shutdown set to %d\n",
2039 				__func__, transport->inet->sk_shutdown);
2040 	}
2041 	xs_abort_connection(transport);
2042 }
2043 
2044 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2045 {
2046 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2047 	int ret = -ENOTCONN;
2048 
2049 	if (!transport->inet) {
2050 		struct sock *sk = sock->sk;
2051 
2052 		write_lock_bh(&sk->sk_callback_lock);
2053 
2054 		xs_save_old_callbacks(transport, sk);
2055 
2056 		sk->sk_user_data = xprt;
2057 		sk->sk_data_ready = xs_tcp_data_ready;
2058 		sk->sk_state_change = xs_tcp_state_change;
2059 		sk->sk_write_space = xs_tcp_write_space;
2060 		sk->sk_error_report = xs_error_report;
2061 		sk->sk_allocation = GFP_ATOMIC;
2062 
2063 		/* socket options */
2064 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2065 		sock_reset_flag(sk, SOCK_LINGER);
2066 		tcp_sk(sk)->linger2 = 0;
2067 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2068 
2069 		xprt_clear_connected(xprt);
2070 
2071 		/* Reset to new socket */
2072 		transport->sock = sock;
2073 		transport->inet = sk;
2074 
2075 		write_unlock_bh(&sk->sk_callback_lock);
2076 	}
2077 
2078 	if (!xprt_bound(xprt))
2079 		goto out;
2080 
2081 	/* Tell the socket layer to start connecting... */
2082 	xprt->stat.connect_count++;
2083 	xprt->stat.connect_start = jiffies;
2084 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2085 	switch (ret) {
2086 	case 0:
2087 	case -EINPROGRESS:
2088 		/* SYN_SENT! */
2089 		xprt->connect_cookie++;
2090 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2091 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2092 	}
2093 out:
2094 	return ret;
2095 }
2096 
2097 /**
2098  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2099  * @xprt: RPC transport to connect
2100  * @transport: socket transport to connect
2101  * @create_sock: function to create a socket of the correct type
2102  *
2103  * Invoked by a work queue tasklet.
2104  */
2105 static void xs_tcp_setup_socket(struct work_struct *work)
2106 {
2107 	struct sock_xprt *transport =
2108 		container_of(work, struct sock_xprt, connect_worker.work);
2109 	struct socket *sock = transport->sock;
2110 	struct rpc_xprt *xprt = &transport->xprt;
2111 	int status = -EIO;
2112 
2113 	if (xprt->shutdown)
2114 		goto out;
2115 
2116 	if (!sock) {
2117 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2118 		sock = xs_create_sock(xprt, transport,
2119 				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2120 		if (IS_ERR(sock)) {
2121 			status = PTR_ERR(sock);
2122 			goto out;
2123 		}
2124 	} else {
2125 		int abort_and_exit;
2126 
2127 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2128 				&xprt->state);
2129 		/* "close" the socket, preserving the local port */
2130 		xs_tcp_reuse_connection(transport);
2131 
2132 		if (abort_and_exit)
2133 			goto out_eagain;
2134 	}
2135 
2136 	dprintk("RPC:       worker connecting xprt %p via %s to "
2137 				"%s (port %s)\n", xprt,
2138 			xprt->address_strings[RPC_DISPLAY_PROTO],
2139 			xprt->address_strings[RPC_DISPLAY_ADDR],
2140 			xprt->address_strings[RPC_DISPLAY_PORT]);
2141 
2142 	status = xs_tcp_finish_connecting(xprt, sock);
2143 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2144 			xprt, -status, xprt_connected(xprt),
2145 			sock->sk->sk_state);
2146 	switch (status) {
2147 	default:
2148 		printk("%s: connect returned unhandled error %d\n",
2149 			__func__, status);
2150 	case -EADDRNOTAVAIL:
2151 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2152 		 * and retry
2153 		 */
2154 		set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
2155 		xprt_force_disconnect(xprt);
2156 		break;
2157 	case -ECONNREFUSED:
2158 	case -ECONNRESET:
2159 	case -ENETUNREACH:
2160 		/* retry with existing socket, after a delay */
2161 	case 0:
2162 	case -EINPROGRESS:
2163 	case -EALREADY:
2164 		xprt_clear_connecting(xprt);
2165 		return;
2166 	case -EINVAL:
2167 		/* Happens, for instance, if the user specified a link
2168 		 * local IPv6 address without a scope-id.
2169 		 */
2170 		goto out;
2171 	}
2172 out_eagain:
2173 	status = -EAGAIN;
2174 out:
2175 	xprt_clear_connecting(xprt);
2176 	xprt_wake_pending_tasks(xprt, status);
2177 }
2178 
2179 /**
2180  * xs_connect - connect a socket to a remote endpoint
2181  * @task: address of RPC task that manages state of connect request
2182  *
2183  * TCP: If the remote end dropped the connection, delay reconnecting.
2184  *
2185  * UDP socket connects are synchronous, but we use a work queue anyway
2186  * to guarantee that even unprivileged user processes can set up a
2187  * socket on a privileged port.
2188  *
2189  * If a UDP socket connect fails, the delay behavior here prevents
2190  * retry floods (hard mounts).
2191  */
2192 static void xs_connect(struct rpc_task *task)
2193 {
2194 	struct rpc_xprt *xprt = task->tk_xprt;
2195 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2196 
2197 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2198 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2199 				"seconds\n",
2200 				xprt, xprt->reestablish_timeout / HZ);
2201 		queue_delayed_work(rpciod_workqueue,
2202 				   &transport->connect_worker,
2203 				   xprt->reestablish_timeout);
2204 		xprt->reestablish_timeout <<= 1;
2205 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2206 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2207 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2208 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2209 	} else {
2210 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2211 		queue_delayed_work(rpciod_workqueue,
2212 				   &transport->connect_worker, 0);
2213 	}
2214 }
2215 
2216 /**
2217  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2218  * @xprt: rpc_xprt struct containing statistics
2219  * @seq: output file
2220  *
2221  */
2222 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2223 {
2224 	long idle_time = 0;
2225 
2226 	if (xprt_connected(xprt))
2227 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2228 
2229 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2230 			"%llu %llu\n",
2231 			xprt->stat.bind_count,
2232 			xprt->stat.connect_count,
2233 			xprt->stat.connect_time,
2234 			idle_time,
2235 			xprt->stat.sends,
2236 			xprt->stat.recvs,
2237 			xprt->stat.bad_xids,
2238 			xprt->stat.req_u,
2239 			xprt->stat.bklog_u);
2240 }
2241 
2242 /**
2243  * xs_udp_print_stats - display UDP socket-specifc stats
2244  * @xprt: rpc_xprt struct containing statistics
2245  * @seq: output file
2246  *
2247  */
2248 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2249 {
2250 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2251 
2252 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
2253 			transport->srcport,
2254 			xprt->stat.bind_count,
2255 			xprt->stat.sends,
2256 			xprt->stat.recvs,
2257 			xprt->stat.bad_xids,
2258 			xprt->stat.req_u,
2259 			xprt->stat.bklog_u);
2260 }
2261 
2262 /**
2263  * xs_tcp_print_stats - display TCP socket-specifc stats
2264  * @xprt: rpc_xprt struct containing statistics
2265  * @seq: output file
2266  *
2267  */
2268 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2269 {
2270 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2271 	long idle_time = 0;
2272 
2273 	if (xprt_connected(xprt))
2274 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2275 
2276 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
2277 			transport->srcport,
2278 			xprt->stat.bind_count,
2279 			xprt->stat.connect_count,
2280 			xprt->stat.connect_time,
2281 			idle_time,
2282 			xprt->stat.sends,
2283 			xprt->stat.recvs,
2284 			xprt->stat.bad_xids,
2285 			xprt->stat.req_u,
2286 			xprt->stat.bklog_u);
2287 }
2288 
2289 /*
2290  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2291  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2292  * to use the server side send routines.
2293  */
2294 static void *bc_malloc(struct rpc_task *task, size_t size)
2295 {
2296 	struct page *page;
2297 	struct rpc_buffer *buf;
2298 
2299 	BUG_ON(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2300 	page = alloc_page(GFP_KERNEL);
2301 
2302 	if (!page)
2303 		return NULL;
2304 
2305 	buf = page_address(page);
2306 	buf->len = PAGE_SIZE;
2307 
2308 	return buf->data;
2309 }
2310 
2311 /*
2312  * Free the space allocated in the bc_alloc routine
2313  */
2314 static void bc_free(void *buffer)
2315 {
2316 	struct rpc_buffer *buf;
2317 
2318 	if (!buffer)
2319 		return;
2320 
2321 	buf = container_of(buffer, struct rpc_buffer, data);
2322 	free_page((unsigned long)buf);
2323 }
2324 
2325 /*
2326  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2327  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2328  */
2329 static int bc_sendto(struct rpc_rqst *req)
2330 {
2331 	int len;
2332 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2333 	struct rpc_xprt *xprt = req->rq_xprt;
2334 	struct sock_xprt *transport =
2335 				container_of(xprt, struct sock_xprt, xprt);
2336 	struct socket *sock = transport->sock;
2337 	unsigned long headoff;
2338 	unsigned long tailoff;
2339 
2340 	xs_encode_stream_record_marker(xbufp);
2341 
2342 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2343 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2344 	len = svc_send_common(sock, xbufp,
2345 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2346 			      xbufp->tail[0].iov_base, tailoff);
2347 
2348 	if (len != xbufp->len) {
2349 		printk(KERN_NOTICE "Error sending entire callback!\n");
2350 		len = -EAGAIN;
2351 	}
2352 
2353 	return len;
2354 }
2355 
2356 /*
2357  * The send routine. Borrows from svc_send
2358  */
2359 static int bc_send_request(struct rpc_task *task)
2360 {
2361 	struct rpc_rqst *req = task->tk_rqstp;
2362 	struct svc_xprt	*xprt;
2363 	struct svc_sock         *svsk;
2364 	u32                     len;
2365 
2366 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2367 	/*
2368 	 * Get the server socket associated with this callback xprt
2369 	 */
2370 	xprt = req->rq_xprt->bc_xprt;
2371 	svsk = container_of(xprt, struct svc_sock, sk_xprt);
2372 
2373 	/*
2374 	 * Grab the mutex to serialize data as the connection is shared
2375 	 * with the fore channel
2376 	 */
2377 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2378 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2379 		if (!mutex_trylock(&xprt->xpt_mutex))
2380 			return -EAGAIN;
2381 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2382 	}
2383 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2384 		len = -ENOTCONN;
2385 	else
2386 		len = bc_sendto(req);
2387 	mutex_unlock(&xprt->xpt_mutex);
2388 
2389 	if (len > 0)
2390 		len = 0;
2391 
2392 	return len;
2393 }
2394 
2395 /*
2396  * The close routine. Since this is client initiated, we do nothing
2397  */
2398 
2399 static void bc_close(struct rpc_xprt *xprt)
2400 {
2401 }
2402 
2403 /*
2404  * The xprt destroy routine. Again, because this connection is client
2405  * initiated, we do nothing
2406  */
2407 
2408 static void bc_destroy(struct rpc_xprt *xprt)
2409 {
2410 }
2411 
2412 static struct rpc_xprt_ops xs_local_ops = {
2413 	.reserve_xprt		= xprt_reserve_xprt,
2414 	.release_xprt		= xs_tcp_release_xprt,
2415 	.rpcbind		= xs_local_rpcbind,
2416 	.set_port		= xs_local_set_port,
2417 	.connect		= xs_connect,
2418 	.buf_alloc		= rpc_malloc,
2419 	.buf_free		= rpc_free,
2420 	.send_request		= xs_local_send_request,
2421 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2422 	.close			= xs_close,
2423 	.destroy		= xs_destroy,
2424 	.print_stats		= xs_local_print_stats,
2425 };
2426 
2427 static struct rpc_xprt_ops xs_udp_ops = {
2428 	.set_buffer_size	= xs_udp_set_buffer_size,
2429 	.reserve_xprt		= xprt_reserve_xprt_cong,
2430 	.release_xprt		= xprt_release_xprt_cong,
2431 	.rpcbind		= rpcb_getport_async,
2432 	.set_port		= xs_set_port,
2433 	.connect		= xs_connect,
2434 	.buf_alloc		= rpc_malloc,
2435 	.buf_free		= rpc_free,
2436 	.send_request		= xs_udp_send_request,
2437 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2438 	.timer			= xs_udp_timer,
2439 	.release_request	= xprt_release_rqst_cong,
2440 	.close			= xs_close,
2441 	.destroy		= xs_destroy,
2442 	.print_stats		= xs_udp_print_stats,
2443 };
2444 
2445 static struct rpc_xprt_ops xs_tcp_ops = {
2446 	.reserve_xprt		= xprt_reserve_xprt,
2447 	.release_xprt		= xs_tcp_release_xprt,
2448 	.rpcbind		= rpcb_getport_async,
2449 	.set_port		= xs_set_port,
2450 	.connect		= xs_connect,
2451 	.buf_alloc		= rpc_malloc,
2452 	.buf_free		= rpc_free,
2453 	.send_request		= xs_tcp_send_request,
2454 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2455 	.close			= xs_tcp_close,
2456 	.destroy		= xs_destroy,
2457 	.print_stats		= xs_tcp_print_stats,
2458 };
2459 
2460 /*
2461  * The rpc_xprt_ops for the server backchannel
2462  */
2463 
2464 static struct rpc_xprt_ops bc_tcp_ops = {
2465 	.reserve_xprt		= xprt_reserve_xprt,
2466 	.release_xprt		= xprt_release_xprt,
2467 	.buf_alloc		= bc_malloc,
2468 	.buf_free		= bc_free,
2469 	.send_request		= bc_send_request,
2470 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2471 	.close			= bc_close,
2472 	.destroy		= bc_destroy,
2473 	.print_stats		= xs_tcp_print_stats,
2474 };
2475 
2476 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2477 {
2478 	static const struct sockaddr_in sin = {
2479 		.sin_family		= AF_INET,
2480 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2481 	};
2482 	static const struct sockaddr_in6 sin6 = {
2483 		.sin6_family		= AF_INET6,
2484 		.sin6_addr		= IN6ADDR_ANY_INIT,
2485 	};
2486 
2487 	switch (family) {
2488 	case AF_LOCAL:
2489 		break;
2490 	case AF_INET:
2491 		memcpy(sap, &sin, sizeof(sin));
2492 		break;
2493 	case AF_INET6:
2494 		memcpy(sap, &sin6, sizeof(sin6));
2495 		break;
2496 	default:
2497 		dprintk("RPC:       %s: Bad address family\n", __func__);
2498 		return -EAFNOSUPPORT;
2499 	}
2500 	return 0;
2501 }
2502 
2503 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2504 				      unsigned int slot_table_size,
2505 				      unsigned int max_slot_table_size)
2506 {
2507 	struct rpc_xprt *xprt;
2508 	struct sock_xprt *new;
2509 
2510 	if (args->addrlen > sizeof(xprt->addr)) {
2511 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2512 		return ERR_PTR(-EBADF);
2513 	}
2514 
2515 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2516 			max_slot_table_size);
2517 	if (xprt == NULL) {
2518 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2519 				"rpc_xprt\n");
2520 		return ERR_PTR(-ENOMEM);
2521 	}
2522 
2523 	new = container_of(xprt, struct sock_xprt, xprt);
2524 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2525 	xprt->addrlen = args->addrlen;
2526 	if (args->srcaddr)
2527 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2528 	else {
2529 		int err;
2530 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2531 					(struct sockaddr *)&new->srcaddr);
2532 		if (err != 0) {
2533 			xprt_free(xprt);
2534 			return ERR_PTR(err);
2535 		}
2536 	}
2537 
2538 	return xprt;
2539 }
2540 
2541 static const struct rpc_timeout xs_local_default_timeout = {
2542 	.to_initval = 10 * HZ,
2543 	.to_maxval = 10 * HZ,
2544 	.to_retries = 2,
2545 };
2546 
2547 /**
2548  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2549  * @args: rpc transport creation arguments
2550  *
2551  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2552  */
2553 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2554 {
2555 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2556 	struct sock_xprt *transport;
2557 	struct rpc_xprt *xprt;
2558 	struct rpc_xprt *ret;
2559 
2560 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2561 			xprt_max_tcp_slot_table_entries);
2562 	if (IS_ERR(xprt))
2563 		return xprt;
2564 	transport = container_of(xprt, struct sock_xprt, xprt);
2565 
2566 	xprt->prot = 0;
2567 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2568 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2569 
2570 	xprt->bind_timeout = XS_BIND_TO;
2571 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2572 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2573 
2574 	xprt->ops = &xs_local_ops;
2575 	xprt->timeout = &xs_local_default_timeout;
2576 
2577 	switch (sun->sun_family) {
2578 	case AF_LOCAL:
2579 		if (sun->sun_path[0] != '/') {
2580 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2581 					sun->sun_path);
2582 			ret = ERR_PTR(-EINVAL);
2583 			goto out_err;
2584 		}
2585 		xprt_set_bound(xprt);
2586 		INIT_DELAYED_WORK(&transport->connect_worker,
2587 					xs_local_setup_socket);
2588 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2589 		break;
2590 	default:
2591 		ret = ERR_PTR(-EAFNOSUPPORT);
2592 		goto out_err;
2593 	}
2594 
2595 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2596 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2597 
2598 	if (try_module_get(THIS_MODULE))
2599 		return xprt;
2600 	ret = ERR_PTR(-EINVAL);
2601 out_err:
2602 	xprt_free(xprt);
2603 	return ret;
2604 }
2605 
2606 static const struct rpc_timeout xs_udp_default_timeout = {
2607 	.to_initval = 5 * HZ,
2608 	.to_maxval = 30 * HZ,
2609 	.to_increment = 5 * HZ,
2610 	.to_retries = 5,
2611 };
2612 
2613 /**
2614  * xs_setup_udp - Set up transport to use a UDP socket
2615  * @args: rpc transport creation arguments
2616  *
2617  */
2618 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2619 {
2620 	struct sockaddr *addr = args->dstaddr;
2621 	struct rpc_xprt *xprt;
2622 	struct sock_xprt *transport;
2623 	struct rpc_xprt *ret;
2624 
2625 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2626 			xprt_udp_slot_table_entries);
2627 	if (IS_ERR(xprt))
2628 		return xprt;
2629 	transport = container_of(xprt, struct sock_xprt, xprt);
2630 
2631 	xprt->prot = IPPROTO_UDP;
2632 	xprt->tsh_size = 0;
2633 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2634 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2635 
2636 	xprt->bind_timeout = XS_BIND_TO;
2637 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2638 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2639 
2640 	xprt->ops = &xs_udp_ops;
2641 
2642 	xprt->timeout = &xs_udp_default_timeout;
2643 
2644 	switch (addr->sa_family) {
2645 	case AF_INET:
2646 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2647 			xprt_set_bound(xprt);
2648 
2649 		INIT_DELAYED_WORK(&transport->connect_worker,
2650 					xs_udp_setup_socket);
2651 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2652 		break;
2653 	case AF_INET6:
2654 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2655 			xprt_set_bound(xprt);
2656 
2657 		INIT_DELAYED_WORK(&transport->connect_worker,
2658 					xs_udp_setup_socket);
2659 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2660 		break;
2661 	default:
2662 		ret = ERR_PTR(-EAFNOSUPPORT);
2663 		goto out_err;
2664 	}
2665 
2666 	if (xprt_bound(xprt))
2667 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2668 				xprt->address_strings[RPC_DISPLAY_ADDR],
2669 				xprt->address_strings[RPC_DISPLAY_PORT],
2670 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2671 	else
2672 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2673 				xprt->address_strings[RPC_DISPLAY_ADDR],
2674 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2675 
2676 	if (try_module_get(THIS_MODULE))
2677 		return xprt;
2678 	ret = ERR_PTR(-EINVAL);
2679 out_err:
2680 	xprt_free(xprt);
2681 	return ret;
2682 }
2683 
2684 static const struct rpc_timeout xs_tcp_default_timeout = {
2685 	.to_initval = 60 * HZ,
2686 	.to_maxval = 60 * HZ,
2687 	.to_retries = 2,
2688 };
2689 
2690 /**
2691  * xs_setup_tcp - Set up transport to use a TCP socket
2692  * @args: rpc transport creation arguments
2693  *
2694  */
2695 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2696 {
2697 	struct sockaddr *addr = args->dstaddr;
2698 	struct rpc_xprt *xprt;
2699 	struct sock_xprt *transport;
2700 	struct rpc_xprt *ret;
2701 
2702 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2703 			xprt_max_tcp_slot_table_entries);
2704 	if (IS_ERR(xprt))
2705 		return xprt;
2706 	transport = container_of(xprt, struct sock_xprt, xprt);
2707 
2708 	xprt->prot = IPPROTO_TCP;
2709 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2710 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2711 
2712 	xprt->bind_timeout = XS_BIND_TO;
2713 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2714 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2715 
2716 	xprt->ops = &xs_tcp_ops;
2717 	xprt->timeout = &xs_tcp_default_timeout;
2718 
2719 	switch (addr->sa_family) {
2720 	case AF_INET:
2721 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2722 			xprt_set_bound(xprt);
2723 
2724 		INIT_DELAYED_WORK(&transport->connect_worker,
2725 					xs_tcp_setup_socket);
2726 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2727 		break;
2728 	case AF_INET6:
2729 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2730 			xprt_set_bound(xprt);
2731 
2732 		INIT_DELAYED_WORK(&transport->connect_worker,
2733 					xs_tcp_setup_socket);
2734 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2735 		break;
2736 	default:
2737 		ret = ERR_PTR(-EAFNOSUPPORT);
2738 		goto out_err;
2739 	}
2740 
2741 	if (xprt_bound(xprt))
2742 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2743 				xprt->address_strings[RPC_DISPLAY_ADDR],
2744 				xprt->address_strings[RPC_DISPLAY_PORT],
2745 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2746 	else
2747 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2748 				xprt->address_strings[RPC_DISPLAY_ADDR],
2749 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2750 
2751 
2752 	if (try_module_get(THIS_MODULE))
2753 		return xprt;
2754 	ret = ERR_PTR(-EINVAL);
2755 out_err:
2756 	xprt_free(xprt);
2757 	return ret;
2758 }
2759 
2760 /**
2761  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2762  * @args: rpc transport creation arguments
2763  *
2764  */
2765 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2766 {
2767 	struct sockaddr *addr = args->dstaddr;
2768 	struct rpc_xprt *xprt;
2769 	struct sock_xprt *transport;
2770 	struct svc_sock *bc_sock;
2771 	struct rpc_xprt *ret;
2772 
2773 	if (args->bc_xprt->xpt_bc_xprt) {
2774 		/*
2775 		 * This server connection already has a backchannel
2776 		 * export; we can't create a new one, as we wouldn't be
2777 		 * able to match replies based on xid any more.  So,
2778 		 * reuse the already-existing one:
2779 		 */
2780 		 return args->bc_xprt->xpt_bc_xprt;
2781 	}
2782 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2783 			xprt_tcp_slot_table_entries);
2784 	if (IS_ERR(xprt))
2785 		return xprt;
2786 	transport = container_of(xprt, struct sock_xprt, xprt);
2787 
2788 	xprt->prot = IPPROTO_TCP;
2789 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2790 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2791 	xprt->timeout = &xs_tcp_default_timeout;
2792 
2793 	/* backchannel */
2794 	xprt_set_bound(xprt);
2795 	xprt->bind_timeout = 0;
2796 	xprt->reestablish_timeout = 0;
2797 	xprt->idle_timeout = 0;
2798 
2799 	xprt->ops = &bc_tcp_ops;
2800 
2801 	switch (addr->sa_family) {
2802 	case AF_INET:
2803 		xs_format_peer_addresses(xprt, "tcp",
2804 					 RPCBIND_NETID_TCP);
2805 		break;
2806 	case AF_INET6:
2807 		xs_format_peer_addresses(xprt, "tcp",
2808 				   RPCBIND_NETID_TCP6);
2809 		break;
2810 	default:
2811 		ret = ERR_PTR(-EAFNOSUPPORT);
2812 		goto out_err;
2813 	}
2814 
2815 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2816 			xprt->address_strings[RPC_DISPLAY_ADDR],
2817 			xprt->address_strings[RPC_DISPLAY_PORT],
2818 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2819 
2820 	/*
2821 	 * Once we've associated a backchannel xprt with a connection,
2822 	 * we want to keep it around as long as long as the connection
2823 	 * lasts, in case we need to start using it for a backchannel
2824 	 * again; this reference won't be dropped until bc_xprt is
2825 	 * destroyed.
2826 	 */
2827 	xprt_get(xprt);
2828 	args->bc_xprt->xpt_bc_xprt = xprt;
2829 	xprt->bc_xprt = args->bc_xprt;
2830 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2831 	transport->sock = bc_sock->sk_sock;
2832 	transport->inet = bc_sock->sk_sk;
2833 
2834 	/*
2835 	 * Since we don't want connections for the backchannel, we set
2836 	 * the xprt status to connected
2837 	 */
2838 	xprt_set_connected(xprt);
2839 
2840 
2841 	if (try_module_get(THIS_MODULE))
2842 		return xprt;
2843 	xprt_put(xprt);
2844 	ret = ERR_PTR(-EINVAL);
2845 out_err:
2846 	xprt_free(xprt);
2847 	return ret;
2848 }
2849 
2850 static struct xprt_class	xs_local_transport = {
2851 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2852 	.name		= "named UNIX socket",
2853 	.owner		= THIS_MODULE,
2854 	.ident		= XPRT_TRANSPORT_LOCAL,
2855 	.setup		= xs_setup_local,
2856 };
2857 
2858 static struct xprt_class	xs_udp_transport = {
2859 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2860 	.name		= "udp",
2861 	.owner		= THIS_MODULE,
2862 	.ident		= XPRT_TRANSPORT_UDP,
2863 	.setup		= xs_setup_udp,
2864 };
2865 
2866 static struct xprt_class	xs_tcp_transport = {
2867 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2868 	.name		= "tcp",
2869 	.owner		= THIS_MODULE,
2870 	.ident		= XPRT_TRANSPORT_TCP,
2871 	.setup		= xs_setup_tcp,
2872 };
2873 
2874 static struct xprt_class	xs_bc_tcp_transport = {
2875 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2876 	.name		= "tcp NFSv4.1 backchannel",
2877 	.owner		= THIS_MODULE,
2878 	.ident		= XPRT_TRANSPORT_BC_TCP,
2879 	.setup		= xs_setup_bc_tcp,
2880 };
2881 
2882 /**
2883  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2884  *
2885  */
2886 int init_socket_xprt(void)
2887 {
2888 #ifdef RPC_DEBUG
2889 	if (!sunrpc_table_header)
2890 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2891 #endif
2892 
2893 	xprt_register_transport(&xs_local_transport);
2894 	xprt_register_transport(&xs_udp_transport);
2895 	xprt_register_transport(&xs_tcp_transport);
2896 	xprt_register_transport(&xs_bc_tcp_transport);
2897 
2898 	return 0;
2899 }
2900 
2901 /**
2902  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2903  *
2904  */
2905 void cleanup_socket_xprt(void)
2906 {
2907 #ifdef RPC_DEBUG
2908 	if (sunrpc_table_header) {
2909 		unregister_sysctl_table(sunrpc_table_header);
2910 		sunrpc_table_header = NULL;
2911 	}
2912 #endif
2913 
2914 	xprt_unregister_transport(&xs_local_transport);
2915 	xprt_unregister_transport(&xs_udp_transport);
2916 	xprt_unregister_transport(&xs_tcp_transport);
2917 	xprt_unregister_transport(&xs_bc_tcp_transport);
2918 }
2919 
2920 static int param_set_uint_minmax(const char *val,
2921 		const struct kernel_param *kp,
2922 		unsigned int min, unsigned int max)
2923 {
2924 	unsigned long num;
2925 	int ret;
2926 
2927 	if (!val)
2928 		return -EINVAL;
2929 	ret = strict_strtoul(val, 0, &num);
2930 	if (ret == -EINVAL || num < min || num > max)
2931 		return -EINVAL;
2932 	*((unsigned int *)kp->arg) = num;
2933 	return 0;
2934 }
2935 
2936 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2937 {
2938 	return param_set_uint_minmax(val, kp,
2939 			RPC_MIN_RESVPORT,
2940 			RPC_MAX_RESVPORT);
2941 }
2942 
2943 static struct kernel_param_ops param_ops_portnr = {
2944 	.set = param_set_portnr,
2945 	.get = param_get_uint,
2946 };
2947 
2948 #define param_check_portnr(name, p) \
2949 	__param_check(name, p, unsigned int);
2950 
2951 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
2952 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
2953 
2954 static int param_set_slot_table_size(const char *val,
2955 				     const struct kernel_param *kp)
2956 {
2957 	return param_set_uint_minmax(val, kp,
2958 			RPC_MIN_SLOT_TABLE,
2959 			RPC_MAX_SLOT_TABLE);
2960 }
2961 
2962 static struct kernel_param_ops param_ops_slot_table_size = {
2963 	.set = param_set_slot_table_size,
2964 	.get = param_get_uint,
2965 };
2966 
2967 #define param_check_slot_table_size(name, p) \
2968 	__param_check(name, p, unsigned int);
2969 
2970 static int param_set_max_slot_table_size(const char *val,
2971 				     const struct kernel_param *kp)
2972 {
2973 	return param_set_uint_minmax(val, kp,
2974 			RPC_MIN_SLOT_TABLE,
2975 			RPC_MAX_SLOT_TABLE_LIMIT);
2976 }
2977 
2978 static struct kernel_param_ops param_ops_max_slot_table_size = {
2979 	.set = param_set_max_slot_table_size,
2980 	.get = param_get_uint,
2981 };
2982 
2983 #define param_check_max_slot_table_size(name, p) \
2984 	__param_check(name, p, unsigned int);
2985 
2986 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
2987 		   slot_table_size, 0644);
2988 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
2989 		   max_slot_table_size, 0644);
2990 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
2991 		   slot_table_size, 0644);
2992 
2993