xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 6a829eb8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/highmem.h>
52 #include <linux/uio.h>
53 
54 #include <trace/events/sunrpc.h>
55 
56 #include "sunrpc.h"
57 
58 static void xs_close(struct rpc_xprt *xprt);
59 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
60 		struct socket *sock);
61 
62 /*
63  * xprtsock tunables
64  */
65 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
66 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
67 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
68 
69 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
70 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
71 
72 #define XS_TCP_LINGER_TO	(15U * HZ)
73 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
74 
75 /*
76  * We can register our own files under /proc/sys/sunrpc by
77  * calling register_sysctl_table() again.  The files in that
78  * directory become the union of all files registered there.
79  *
80  * We simply need to make sure that we don't collide with
81  * someone else's file names!
82  */
83 
84 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
85 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
86 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
87 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
88 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
89 
90 static struct ctl_table_header *sunrpc_table_header;
91 
92 /*
93  * FIXME: changing the UDP slot table size should also resize the UDP
94  *        socket buffers for existing UDP transports
95  */
96 static struct ctl_table xs_tunables_table[] = {
97 	{
98 		.procname	= "udp_slot_table_entries",
99 		.data		= &xprt_udp_slot_table_entries,
100 		.maxlen		= sizeof(unsigned int),
101 		.mode		= 0644,
102 		.proc_handler	= proc_dointvec_minmax,
103 		.extra1		= &min_slot_table_size,
104 		.extra2		= &max_slot_table_size
105 	},
106 	{
107 		.procname	= "tcp_slot_table_entries",
108 		.data		= &xprt_tcp_slot_table_entries,
109 		.maxlen		= sizeof(unsigned int),
110 		.mode		= 0644,
111 		.proc_handler	= proc_dointvec_minmax,
112 		.extra1		= &min_slot_table_size,
113 		.extra2		= &max_slot_table_size
114 	},
115 	{
116 		.procname	= "tcp_max_slot_table_entries",
117 		.data		= &xprt_max_tcp_slot_table_entries,
118 		.maxlen		= sizeof(unsigned int),
119 		.mode		= 0644,
120 		.proc_handler	= proc_dointvec_minmax,
121 		.extra1		= &min_slot_table_size,
122 		.extra2		= &max_tcp_slot_table_limit
123 	},
124 	{
125 		.procname	= "min_resvport",
126 		.data		= &xprt_min_resvport,
127 		.maxlen		= sizeof(unsigned int),
128 		.mode		= 0644,
129 		.proc_handler	= proc_dointvec_minmax,
130 		.extra1		= &xprt_min_resvport_limit,
131 		.extra2		= &xprt_max_resvport_limit
132 	},
133 	{
134 		.procname	= "max_resvport",
135 		.data		= &xprt_max_resvport,
136 		.maxlen		= sizeof(unsigned int),
137 		.mode		= 0644,
138 		.proc_handler	= proc_dointvec_minmax,
139 		.extra1		= &xprt_min_resvport_limit,
140 		.extra2		= &xprt_max_resvport_limit
141 	},
142 	{
143 		.procname	= "tcp_fin_timeout",
144 		.data		= &xs_tcp_fin_timeout,
145 		.maxlen		= sizeof(xs_tcp_fin_timeout),
146 		.mode		= 0644,
147 		.proc_handler	= proc_dointvec_jiffies,
148 	},
149 	{ },
150 };
151 
152 static struct ctl_table sunrpc_table[] = {
153 	{
154 		.procname	= "sunrpc",
155 		.mode		= 0555,
156 		.child		= xs_tunables_table
157 	},
158 	{ },
159 };
160 
161 /*
162  * Wait duration for a reply from the RPC portmapper.
163  */
164 #define XS_BIND_TO		(60U * HZ)
165 
166 /*
167  * Delay if a UDP socket connect error occurs.  This is most likely some
168  * kind of resource problem on the local host.
169  */
170 #define XS_UDP_REEST_TO		(2U * HZ)
171 
172 /*
173  * The reestablish timeout allows clients to delay for a bit before attempting
174  * to reconnect to a server that just dropped our connection.
175  *
176  * We implement an exponential backoff when trying to reestablish a TCP
177  * transport connection with the server.  Some servers like to drop a TCP
178  * connection when they are overworked, so we start with a short timeout and
179  * increase over time if the server is down or not responding.
180  */
181 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
182 
183 /*
184  * TCP idle timeout; client drops the transport socket if it is idle
185  * for this long.  Note that we also timeout UDP sockets to prevent
186  * holding port numbers when there is no RPC traffic.
187  */
188 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
189 
190 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
191 # undef  RPC_DEBUG_DATA
192 # define RPCDBG_FACILITY	RPCDBG_TRANS
193 #endif
194 
195 #ifdef RPC_DEBUG_DATA
196 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
197 {
198 	u8 *buf = (u8 *) packet;
199 	int j;
200 
201 	dprintk("RPC:       %s\n", msg);
202 	for (j = 0; j < count && j < 128; j += 4) {
203 		if (!(j & 31)) {
204 			if (j)
205 				dprintk("\n");
206 			dprintk("0x%04x ", j);
207 		}
208 		dprintk("%02x%02x%02x%02x ",
209 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
210 	}
211 	dprintk("\n");
212 }
213 #else
214 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
215 {
216 	/* NOP */
217 }
218 #endif
219 
220 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
221 {
222 	return (struct rpc_xprt *) sk->sk_user_data;
223 }
224 
225 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
226 {
227 	return (struct sockaddr *) &xprt->addr;
228 }
229 
230 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
231 {
232 	return (struct sockaddr_un *) &xprt->addr;
233 }
234 
235 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
236 {
237 	return (struct sockaddr_in *) &xprt->addr;
238 }
239 
240 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
241 {
242 	return (struct sockaddr_in6 *) &xprt->addr;
243 }
244 
245 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
246 {
247 	struct sockaddr *sap = xs_addr(xprt);
248 	struct sockaddr_in6 *sin6;
249 	struct sockaddr_in *sin;
250 	struct sockaddr_un *sun;
251 	char buf[128];
252 
253 	switch (sap->sa_family) {
254 	case AF_LOCAL:
255 		sun = xs_addr_un(xprt);
256 		strlcpy(buf, sun->sun_path, sizeof(buf));
257 		xprt->address_strings[RPC_DISPLAY_ADDR] =
258 						kstrdup(buf, GFP_KERNEL);
259 		break;
260 	case AF_INET:
261 		(void)rpc_ntop(sap, buf, sizeof(buf));
262 		xprt->address_strings[RPC_DISPLAY_ADDR] =
263 						kstrdup(buf, GFP_KERNEL);
264 		sin = xs_addr_in(xprt);
265 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
266 		break;
267 	case AF_INET6:
268 		(void)rpc_ntop(sap, buf, sizeof(buf));
269 		xprt->address_strings[RPC_DISPLAY_ADDR] =
270 						kstrdup(buf, GFP_KERNEL);
271 		sin6 = xs_addr_in6(xprt);
272 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
273 		break;
274 	default:
275 		BUG();
276 	}
277 
278 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
279 }
280 
281 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
282 {
283 	struct sockaddr *sap = xs_addr(xprt);
284 	char buf[128];
285 
286 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
287 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
288 
289 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
290 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
291 }
292 
293 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
294 				     const char *protocol,
295 				     const char *netid)
296 {
297 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
298 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
299 	xs_format_common_peer_addresses(xprt);
300 	xs_format_common_peer_ports(xprt);
301 }
302 
303 static void xs_update_peer_port(struct rpc_xprt *xprt)
304 {
305 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
306 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
307 
308 	xs_format_common_peer_ports(xprt);
309 }
310 
311 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
312 {
313 	unsigned int i;
314 
315 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
316 		switch (i) {
317 		case RPC_DISPLAY_PROTO:
318 		case RPC_DISPLAY_NETID:
319 			continue;
320 		default:
321 			kfree(xprt->address_strings[i]);
322 		}
323 }
324 
325 static size_t
326 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
327 {
328 	size_t i,n;
329 
330 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
331 		return want;
332 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
333 	for (i = 0; i < n; i++) {
334 		if (buf->pages[i])
335 			continue;
336 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
337 		if (!buf->pages[i]) {
338 			i *= PAGE_SIZE;
339 			return i > buf->page_base ? i - buf->page_base : 0;
340 		}
341 	}
342 	return want;
343 }
344 
345 static ssize_t
346 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
347 {
348 	ssize_t ret;
349 	if (seek != 0)
350 		iov_iter_advance(&msg->msg_iter, seek);
351 	ret = sock_recvmsg(sock, msg, flags);
352 	return ret > 0 ? ret + seek : ret;
353 }
354 
355 static ssize_t
356 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
357 		struct kvec *kvec, size_t count, size_t seek)
358 {
359 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
360 	return xs_sock_recvmsg(sock, msg, flags, seek);
361 }
362 
363 static ssize_t
364 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
365 		struct bio_vec *bvec, unsigned long nr, size_t count,
366 		size_t seek)
367 {
368 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
369 	return xs_sock_recvmsg(sock, msg, flags, seek);
370 }
371 
372 static ssize_t
373 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
374 		size_t count)
375 {
376 	iov_iter_discard(&msg->msg_iter, READ, count);
377 	return sock_recvmsg(sock, msg, flags);
378 }
379 
380 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
381 static void
382 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
383 {
384 	struct bvec_iter bi = {
385 		.bi_size = count,
386 	};
387 	struct bio_vec bv;
388 
389 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
390 	for_each_bvec(bv, bvec, bi, bi)
391 		flush_dcache_page(bv.bv_page);
392 }
393 #else
394 static inline void
395 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
396 {
397 }
398 #endif
399 
400 static ssize_t
401 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
402 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
403 {
404 	size_t want, seek_init = seek, offset = 0;
405 	ssize_t ret;
406 
407 	if (seek < buf->head[0].iov_len) {
408 		want = min_t(size_t, count, buf->head[0].iov_len);
409 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
410 		if (ret <= 0)
411 			goto sock_err;
412 		offset += ret;
413 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
414 			goto out;
415 		if (ret != want)
416 			goto out;
417 		seek = 0;
418 	} else {
419 		seek -= buf->head[0].iov_len;
420 		offset += buf->head[0].iov_len;
421 	}
422 
423 	want = xs_alloc_sparse_pages(buf,
424 			min_t(size_t, count - offset, buf->page_len),
425 			GFP_NOWAIT);
426 	if (seek < want) {
427 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
428 				xdr_buf_pagecount(buf),
429 				want + buf->page_base,
430 				seek + buf->page_base);
431 		if (ret <= 0)
432 			goto sock_err;
433 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
434 		offset += ret - buf->page_base;
435 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
436 			goto out;
437 		if (ret != want)
438 			goto out;
439 		seek = 0;
440 	} else {
441 		seek -= want;
442 		offset += want;
443 	}
444 
445 	if (seek < buf->tail[0].iov_len) {
446 		want = min_t(size_t, count - offset, buf->tail[0].iov_len);
447 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
448 		if (ret <= 0)
449 			goto sock_err;
450 		offset += ret;
451 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
452 			goto out;
453 		if (ret != want)
454 			goto out;
455 	} else
456 		offset += buf->tail[0].iov_len;
457 	ret = -EMSGSIZE;
458 out:
459 	*read = offset - seek_init;
460 	return ret;
461 sock_err:
462 	offset += seek;
463 	goto out;
464 }
465 
466 static void
467 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
468 {
469 	if (!transport->recv.copied) {
470 		if (buf->head[0].iov_len >= transport->recv.offset)
471 			memcpy(buf->head[0].iov_base,
472 					&transport->recv.xid,
473 					transport->recv.offset);
474 		transport->recv.copied = transport->recv.offset;
475 	}
476 }
477 
478 static bool
479 xs_read_stream_request_done(struct sock_xprt *transport)
480 {
481 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
482 }
483 
484 static ssize_t
485 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
486 		int flags, struct rpc_rqst *req)
487 {
488 	struct xdr_buf *buf = &req->rq_private_buf;
489 	size_t want, read;
490 	ssize_t ret;
491 
492 	xs_read_header(transport, buf);
493 
494 	want = transport->recv.len - transport->recv.offset;
495 	ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
496 			transport->recv.copied + want, transport->recv.copied,
497 			&read);
498 	transport->recv.offset += read;
499 	transport->recv.copied += read;
500 	if (transport->recv.offset == transport->recv.len) {
501 		if (xs_read_stream_request_done(transport))
502 			msg->msg_flags |= MSG_EOR;
503 		return read;
504 	}
505 
506 	switch (ret) {
507 	default:
508 		break;
509 	case -EFAULT:
510 	case -EMSGSIZE:
511 		msg->msg_flags |= MSG_TRUNC;
512 		return read;
513 	case 0:
514 		return -ESHUTDOWN;
515 	}
516 	return ret < 0 ? ret : read;
517 }
518 
519 static size_t
520 xs_read_stream_headersize(bool isfrag)
521 {
522 	if (isfrag)
523 		return sizeof(__be32);
524 	return 3 * sizeof(__be32);
525 }
526 
527 static ssize_t
528 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
529 		int flags, size_t want, size_t seek)
530 {
531 	struct kvec kvec = {
532 		.iov_base = &transport->recv.fraghdr,
533 		.iov_len = want,
534 	};
535 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
536 }
537 
538 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
539 static ssize_t
540 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
541 {
542 	struct rpc_xprt *xprt = &transport->xprt;
543 	struct rpc_rqst *req;
544 	ssize_t ret;
545 
546 	/* Look up and lock the request corresponding to the given XID */
547 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
548 	if (!req) {
549 		printk(KERN_WARNING "Callback slot table overflowed\n");
550 		return -ESHUTDOWN;
551 	}
552 
553 	ret = xs_read_stream_request(transport, msg, flags, req);
554 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
555 		xprt_complete_bc_request(req, transport->recv.copied);
556 
557 	return ret;
558 }
559 #else /* CONFIG_SUNRPC_BACKCHANNEL */
560 static ssize_t
561 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
562 {
563 	return -ESHUTDOWN;
564 }
565 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
566 
567 static ssize_t
568 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
569 {
570 	struct rpc_xprt *xprt = &transport->xprt;
571 	struct rpc_rqst *req;
572 	ssize_t ret = 0;
573 
574 	/* Look up and lock the request corresponding to the given XID */
575 	spin_lock(&xprt->queue_lock);
576 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
577 	if (!req) {
578 		msg->msg_flags |= MSG_TRUNC;
579 		goto out;
580 	}
581 	xprt_pin_rqst(req);
582 	spin_unlock(&xprt->queue_lock);
583 
584 	ret = xs_read_stream_request(transport, msg, flags, req);
585 
586 	spin_lock(&xprt->queue_lock);
587 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
588 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
589 	xprt_unpin_rqst(req);
590 out:
591 	spin_unlock(&xprt->queue_lock);
592 	return ret;
593 }
594 
595 static ssize_t
596 xs_read_stream(struct sock_xprt *transport, int flags)
597 {
598 	struct msghdr msg = { 0 };
599 	size_t want, read = 0;
600 	ssize_t ret = 0;
601 
602 	if (transport->recv.len == 0) {
603 		want = xs_read_stream_headersize(transport->recv.copied != 0);
604 		ret = xs_read_stream_header(transport, &msg, flags, want,
605 				transport->recv.offset);
606 		if (ret <= 0)
607 			goto out_err;
608 		transport->recv.offset = ret;
609 		if (transport->recv.offset != want)
610 			return transport->recv.offset;
611 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
612 			RPC_FRAGMENT_SIZE_MASK;
613 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
614 		read = ret;
615 	}
616 
617 	switch (be32_to_cpu(transport->recv.calldir)) {
618 	default:
619 		msg.msg_flags |= MSG_TRUNC;
620 		break;
621 	case RPC_CALL:
622 		ret = xs_read_stream_call(transport, &msg, flags);
623 		break;
624 	case RPC_REPLY:
625 		ret = xs_read_stream_reply(transport, &msg, flags);
626 	}
627 	if (msg.msg_flags & MSG_TRUNC) {
628 		transport->recv.calldir = cpu_to_be32(-1);
629 		transport->recv.copied = -1;
630 	}
631 	if (ret < 0)
632 		goto out_err;
633 	read += ret;
634 	if (transport->recv.offset < transport->recv.len) {
635 		if (!(msg.msg_flags & MSG_TRUNC))
636 			return read;
637 		msg.msg_flags = 0;
638 		ret = xs_read_discard(transport->sock, &msg, flags,
639 				transport->recv.len - transport->recv.offset);
640 		if (ret <= 0)
641 			goto out_err;
642 		transport->recv.offset += ret;
643 		read += ret;
644 		if (transport->recv.offset != transport->recv.len)
645 			return read;
646 	}
647 	if (xs_read_stream_request_done(transport)) {
648 		trace_xs_stream_read_request(transport);
649 		transport->recv.copied = 0;
650 	}
651 	transport->recv.offset = 0;
652 	transport->recv.len = 0;
653 	return read;
654 out_err:
655 	return ret != 0 ? ret : -ESHUTDOWN;
656 }
657 
658 static void xs_stream_data_receive(struct sock_xprt *transport)
659 {
660 	size_t read = 0;
661 	ssize_t ret = 0;
662 
663 	mutex_lock(&transport->recv_mutex);
664 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
665 	if (transport->sock == NULL)
666 		goto out;
667 	for (;;) {
668 		ret = xs_read_stream(transport, MSG_DONTWAIT);
669 		if (ret < 0)
670 			break;
671 		read += ret;
672 		cond_resched();
673 	}
674 out:
675 	mutex_unlock(&transport->recv_mutex);
676 	trace_xs_stream_read_data(&transport->xprt, ret, read);
677 }
678 
679 static void xs_stream_data_receive_workfn(struct work_struct *work)
680 {
681 	struct sock_xprt *transport =
682 		container_of(work, struct sock_xprt, recv_worker);
683 	xs_stream_data_receive(transport);
684 }
685 
686 static void
687 xs_stream_reset_connect(struct sock_xprt *transport)
688 {
689 	transport->recv.offset = 0;
690 	transport->recv.len = 0;
691 	transport->recv.copied = 0;
692 	transport->xmit.offset = 0;
693 	transport->xprt.stat.connect_count++;
694 	transport->xprt.stat.connect_start = jiffies;
695 }
696 
697 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
698 
699 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
700 {
701 	struct msghdr msg = {
702 		.msg_name	= addr,
703 		.msg_namelen	= addrlen,
704 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
705 	};
706 	struct kvec iov = {
707 		.iov_base	= vec->iov_base + base,
708 		.iov_len	= vec->iov_len - base,
709 	};
710 
711 	if (iov.iov_len != 0)
712 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
713 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
714 }
715 
716 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
717 {
718 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
719 			int offset, size_t size, int flags);
720 	struct page **ppage;
721 	unsigned int remainder;
722 	int err;
723 
724 	remainder = xdr->page_len - base;
725 	base += xdr->page_base;
726 	ppage = xdr->pages + (base >> PAGE_SHIFT);
727 	base &= ~PAGE_MASK;
728 	do_sendpage = sock->ops->sendpage;
729 	if (!zerocopy)
730 		do_sendpage = sock_no_sendpage;
731 	for(;;) {
732 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
733 		int flags = XS_SENDMSG_FLAGS;
734 
735 		remainder -= len;
736 		if (more)
737 			flags |= MSG_MORE;
738 		if (remainder != 0)
739 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
740 		err = do_sendpage(sock, *ppage, base, len, flags);
741 		if (remainder == 0 || err != len)
742 			break;
743 		*sent_p += err;
744 		ppage++;
745 		base = 0;
746 	}
747 	if (err > 0) {
748 		*sent_p += err;
749 		err = 0;
750 	}
751 	return err;
752 }
753 
754 /**
755  * xs_sendpages - write pages directly to a socket
756  * @sock: socket to send on
757  * @addr: UDP only -- address of destination
758  * @addrlen: UDP only -- length of destination address
759  * @xdr: buffer containing this request
760  * @base: starting position in the buffer
761  * @zerocopy: true if it is safe to use sendpage()
762  * @sent_p: return the total number of bytes successfully queued for sending
763  *
764  */
765 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
766 {
767 	unsigned int remainder = xdr->len - base;
768 	int err = 0;
769 	int sent = 0;
770 
771 	if (unlikely(!sock))
772 		return -ENOTSOCK;
773 
774 	if (base != 0) {
775 		addr = NULL;
776 		addrlen = 0;
777 	}
778 
779 	if (base < xdr->head[0].iov_len || addr != NULL) {
780 		unsigned int len = xdr->head[0].iov_len - base;
781 		remainder -= len;
782 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
783 		if (remainder == 0 || err != len)
784 			goto out;
785 		*sent_p += err;
786 		base = 0;
787 	} else
788 		base -= xdr->head[0].iov_len;
789 
790 	if (base < xdr->page_len) {
791 		unsigned int len = xdr->page_len - base;
792 		remainder -= len;
793 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
794 		*sent_p += sent;
795 		if (remainder == 0 || sent != len)
796 			goto out;
797 		base = 0;
798 	} else
799 		base -= xdr->page_len;
800 
801 	if (base >= xdr->tail[0].iov_len)
802 		return 0;
803 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
804 out:
805 	if (err > 0) {
806 		*sent_p += err;
807 		err = 0;
808 	}
809 	return err;
810 }
811 
812 /**
813  * xs_nospace - handle transmit was incomplete
814  * @req: pointer to RPC request
815  *
816  */
817 static int xs_nospace(struct rpc_rqst *req)
818 {
819 	struct rpc_xprt *xprt = req->rq_xprt;
820 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
821 	struct sock *sk = transport->inet;
822 	int ret = -EAGAIN;
823 
824 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
825 			req->rq_task->tk_pid,
826 			req->rq_slen - transport->xmit.offset,
827 			req->rq_slen);
828 
829 	/* Protect against races with write_space */
830 	spin_lock_bh(&xprt->transport_lock);
831 
832 	/* Don't race with disconnect */
833 	if (xprt_connected(xprt)) {
834 		/* wait for more buffer space */
835 		sk->sk_write_pending++;
836 		xprt_wait_for_buffer_space(xprt);
837 	} else
838 		ret = -ENOTCONN;
839 
840 	spin_unlock_bh(&xprt->transport_lock);
841 
842 	/* Race breaker in case memory is freed before above code is called */
843 	if (ret == -EAGAIN) {
844 		struct socket_wq *wq;
845 
846 		rcu_read_lock();
847 		wq = rcu_dereference(sk->sk_wq);
848 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
849 		rcu_read_unlock();
850 
851 		sk->sk_write_space(sk);
852 	}
853 	return ret;
854 }
855 
856 static void
857 xs_stream_prepare_request(struct rpc_rqst *req)
858 {
859 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_NOIO);
860 }
861 
862 /*
863  * Determine if the previous message in the stream was aborted before it
864  * could complete transmission.
865  */
866 static bool
867 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
868 {
869 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
870 }
871 
872 /*
873  * Construct a stream transport record marker in @buf.
874  */
875 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
876 {
877 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
878 	rpc_fraghdr *base = buf->head[0].iov_base;
879 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
880 }
881 
882 /**
883  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
884  * @req: pointer to RPC request
885  *
886  * Return values:
887  *        0:	The request has been sent
888  *   EAGAIN:	The socket was blocked, please call again later to
889  *		complete the request
890  * ENOTCONN:	Caller needs to invoke connect logic then call again
891  *    other:	Some other error occured, the request was not sent
892  */
893 static int xs_local_send_request(struct rpc_rqst *req)
894 {
895 	struct rpc_xprt *xprt = req->rq_xprt;
896 	struct sock_xprt *transport =
897 				container_of(xprt, struct sock_xprt, xprt);
898 	struct xdr_buf *xdr = &req->rq_snd_buf;
899 	int status;
900 	int sent = 0;
901 
902 	/* Close the stream if the previous transmission was incomplete */
903 	if (xs_send_request_was_aborted(transport, req)) {
904 		xs_close(xprt);
905 		return -ENOTCONN;
906 	}
907 
908 	xs_encode_stream_record_marker(&req->rq_snd_buf);
909 
910 	xs_pktdump("packet data:",
911 			req->rq_svec->iov_base, req->rq_svec->iov_len);
912 
913 	req->rq_xtime = ktime_get();
914 	status = xs_sendpages(transport->sock, NULL, 0, xdr,
915 			      transport->xmit.offset,
916 			      true, &sent);
917 	dprintk("RPC:       %s(%u) = %d\n",
918 			__func__, xdr->len - transport->xmit.offset, status);
919 
920 	if (status == -EAGAIN && sock_writeable(transport->inet))
921 		status = -ENOBUFS;
922 
923 	if (likely(sent > 0) || status == 0) {
924 		transport->xmit.offset += sent;
925 		req->rq_bytes_sent = transport->xmit.offset;
926 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
927 			req->rq_xmit_bytes_sent += transport->xmit.offset;
928 			req->rq_bytes_sent = 0;
929 			transport->xmit.offset = 0;
930 			return 0;
931 		}
932 		status = -EAGAIN;
933 	}
934 
935 	switch (status) {
936 	case -ENOBUFS:
937 		break;
938 	case -EAGAIN:
939 		status = xs_nospace(req);
940 		break;
941 	default:
942 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
943 			-status);
944 		/* fall through */
945 	case -EPIPE:
946 		xs_close(xprt);
947 		status = -ENOTCONN;
948 	}
949 
950 	return status;
951 }
952 
953 /**
954  * xs_udp_send_request - write an RPC request to a UDP socket
955  * @req: pointer to RPC request
956  *
957  * Return values:
958  *        0:	The request has been sent
959  *   EAGAIN:	The socket was blocked, please call again later to
960  *		complete the request
961  * ENOTCONN:	Caller needs to invoke connect logic then call again
962  *    other:	Some other error occurred, the request was not sent
963  */
964 static int xs_udp_send_request(struct rpc_rqst *req)
965 {
966 	struct rpc_xprt *xprt = req->rq_xprt;
967 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
968 	struct xdr_buf *xdr = &req->rq_snd_buf;
969 	int sent = 0;
970 	int status;
971 
972 	xs_pktdump("packet data:",
973 				req->rq_svec->iov_base,
974 				req->rq_svec->iov_len);
975 
976 	if (!xprt_bound(xprt))
977 		return -ENOTCONN;
978 
979 	if (!xprt_request_get_cong(xprt, req))
980 		return -EBADSLT;
981 
982 	req->rq_xtime = ktime_get();
983 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
984 			      xdr, 0, true, &sent);
985 
986 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
987 			xdr->len, status);
988 
989 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
990 	if (status == -EPERM)
991 		goto process_status;
992 
993 	if (status == -EAGAIN && sock_writeable(transport->inet))
994 		status = -ENOBUFS;
995 
996 	if (sent > 0 || status == 0) {
997 		req->rq_xmit_bytes_sent += sent;
998 		if (sent >= req->rq_slen)
999 			return 0;
1000 		/* Still some bytes left; set up for a retry later. */
1001 		status = -EAGAIN;
1002 	}
1003 
1004 process_status:
1005 	switch (status) {
1006 	case -ENOTSOCK:
1007 		status = -ENOTCONN;
1008 		/* Should we call xs_close() here? */
1009 		break;
1010 	case -EAGAIN:
1011 		status = xs_nospace(req);
1012 		break;
1013 	case -ENETUNREACH:
1014 	case -ENOBUFS:
1015 	case -EPIPE:
1016 	case -ECONNREFUSED:
1017 	case -EPERM:
1018 		/* When the server has died, an ICMP port unreachable message
1019 		 * prompts ECONNREFUSED. */
1020 		break;
1021 	default:
1022 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1023 			-status);
1024 	}
1025 
1026 	return status;
1027 }
1028 
1029 /**
1030  * xs_tcp_send_request - write an RPC request to a TCP socket
1031  * @req: pointer to RPC request
1032  *
1033  * Return values:
1034  *        0:	The request has been sent
1035  *   EAGAIN:	The socket was blocked, please call again later to
1036  *		complete the request
1037  * ENOTCONN:	Caller needs to invoke connect logic then call again
1038  *    other:	Some other error occurred, the request was not sent
1039  *
1040  * XXX: In the case of soft timeouts, should we eventually give up
1041  *	if sendmsg is not able to make progress?
1042  */
1043 static int xs_tcp_send_request(struct rpc_rqst *req)
1044 {
1045 	struct rpc_xprt *xprt = req->rq_xprt;
1046 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1047 	struct xdr_buf *xdr = &req->rq_snd_buf;
1048 	bool zerocopy = true;
1049 	bool vm_wait = false;
1050 	int status;
1051 	int sent;
1052 
1053 	/* Close the stream if the previous transmission was incomplete */
1054 	if (xs_send_request_was_aborted(transport, req)) {
1055 		if (transport->sock != NULL)
1056 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1057 		return -ENOTCONN;
1058 	}
1059 
1060 	xs_encode_stream_record_marker(&req->rq_snd_buf);
1061 
1062 	xs_pktdump("packet data:",
1063 				req->rq_svec->iov_base,
1064 				req->rq_svec->iov_len);
1065 	/* Don't use zero copy if this is a resend. If the RPC call
1066 	 * completes while the socket holds a reference to the pages,
1067 	 * then we may end up resending corrupted data.
1068 	 */
1069 	if (req->rq_task->tk_flags & RPC_TASK_SENT)
1070 		zerocopy = false;
1071 
1072 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1073 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1074 
1075 	/* Continue transmitting the packet/record. We must be careful
1076 	 * to cope with writespace callbacks arriving _after_ we have
1077 	 * called sendmsg(). */
1078 	req->rq_xtime = ktime_get();
1079 	while (1) {
1080 		sent = 0;
1081 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
1082 				      transport->xmit.offset,
1083 				      zerocopy, &sent);
1084 
1085 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1086 				xdr->len - transport->xmit.offset, status);
1087 
1088 		/* If we've sent the entire packet, immediately
1089 		 * reset the count of bytes sent. */
1090 		transport->xmit.offset += sent;
1091 		req->rq_bytes_sent = transport->xmit.offset;
1092 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
1093 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1094 			req->rq_bytes_sent = 0;
1095 			transport->xmit.offset = 0;
1096 			return 0;
1097 		}
1098 
1099 		WARN_ON_ONCE(sent == 0 && status == 0);
1100 
1101 		if (status == -EAGAIN ) {
1102 			/*
1103 			 * Return EAGAIN if we're sure we're hitting the
1104 			 * socket send buffer limits.
1105 			 */
1106 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1107 				break;
1108 			/*
1109 			 * Did we hit a memory allocation failure?
1110 			 */
1111 			if (sent == 0) {
1112 				status = -ENOBUFS;
1113 				if (vm_wait)
1114 					break;
1115 				/* Retry, knowing now that we're below the
1116 				 * socket send buffer limit
1117 				 */
1118 				vm_wait = true;
1119 			}
1120 			continue;
1121 		}
1122 		if (status < 0)
1123 			break;
1124 		vm_wait = false;
1125 	}
1126 
1127 	switch (status) {
1128 	case -ENOTSOCK:
1129 		status = -ENOTCONN;
1130 		/* Should we call xs_close() here? */
1131 		break;
1132 	case -EAGAIN:
1133 		status = xs_nospace(req);
1134 		break;
1135 	case -ECONNRESET:
1136 	case -ECONNREFUSED:
1137 	case -ENOTCONN:
1138 	case -EADDRINUSE:
1139 	case -ENOBUFS:
1140 	case -EPIPE:
1141 		break;
1142 	default:
1143 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1144 			-status);
1145 	}
1146 
1147 	return status;
1148 }
1149 
1150 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1151 {
1152 	transport->old_data_ready = sk->sk_data_ready;
1153 	transport->old_state_change = sk->sk_state_change;
1154 	transport->old_write_space = sk->sk_write_space;
1155 	transport->old_error_report = sk->sk_error_report;
1156 }
1157 
1158 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1159 {
1160 	sk->sk_data_ready = transport->old_data_ready;
1161 	sk->sk_state_change = transport->old_state_change;
1162 	sk->sk_write_space = transport->old_write_space;
1163 	sk->sk_error_report = transport->old_error_report;
1164 }
1165 
1166 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1167 {
1168 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1169 
1170 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1171 }
1172 
1173 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1174 {
1175 	smp_mb__before_atomic();
1176 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1177 	clear_bit(XPRT_CLOSING, &xprt->state);
1178 	xs_sock_reset_state_flags(xprt);
1179 	smp_mb__after_atomic();
1180 }
1181 
1182 /**
1183  * xs_error_report - callback to handle TCP socket state errors
1184  * @sk: socket
1185  *
1186  * Note: we don't call sock_error() since there may be a rpc_task
1187  * using the socket, and so we don't want to clear sk->sk_err.
1188  */
1189 static void xs_error_report(struct sock *sk)
1190 {
1191 	struct rpc_xprt *xprt;
1192 	int err;
1193 
1194 	read_lock_bh(&sk->sk_callback_lock);
1195 	if (!(xprt = xprt_from_sock(sk)))
1196 		goto out;
1197 
1198 	err = -sk->sk_err;
1199 	if (err == 0)
1200 		goto out;
1201 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1202 			xprt, -err);
1203 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
1204 	xprt_wake_pending_tasks(xprt, err);
1205  out:
1206 	read_unlock_bh(&sk->sk_callback_lock);
1207 }
1208 
1209 static void xs_reset_transport(struct sock_xprt *transport)
1210 {
1211 	struct socket *sock = transport->sock;
1212 	struct sock *sk = transport->inet;
1213 	struct rpc_xprt *xprt = &transport->xprt;
1214 
1215 	if (sk == NULL)
1216 		return;
1217 
1218 	if (atomic_read(&transport->xprt.swapper))
1219 		sk_clear_memalloc(sk);
1220 
1221 	kernel_sock_shutdown(sock, SHUT_RDWR);
1222 
1223 	mutex_lock(&transport->recv_mutex);
1224 	write_lock_bh(&sk->sk_callback_lock);
1225 	transport->inet = NULL;
1226 	transport->sock = NULL;
1227 
1228 	sk->sk_user_data = NULL;
1229 
1230 	xs_restore_old_callbacks(transport, sk);
1231 	xprt_clear_connected(xprt);
1232 	write_unlock_bh(&sk->sk_callback_lock);
1233 	xs_sock_reset_connection_flags(xprt);
1234 	mutex_unlock(&transport->recv_mutex);
1235 
1236 	trace_rpc_socket_close(xprt, sock);
1237 	sock_release(sock);
1238 
1239 	xprt_disconnect_done(xprt);
1240 }
1241 
1242 /**
1243  * xs_close - close a socket
1244  * @xprt: transport
1245  *
1246  * This is used when all requests are complete; ie, no DRC state remains
1247  * on the server we want to save.
1248  *
1249  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1250  * xs_reset_transport() zeroing the socket from underneath a writer.
1251  */
1252 static void xs_close(struct rpc_xprt *xprt)
1253 {
1254 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1255 
1256 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1257 
1258 	xs_reset_transport(transport);
1259 	xprt->reestablish_timeout = 0;
1260 }
1261 
1262 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1263 {
1264 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1265 		xprt);
1266 	xprt_disconnect_done(xprt);
1267 }
1268 
1269 static void xs_xprt_free(struct rpc_xprt *xprt)
1270 {
1271 	xs_free_peer_addresses(xprt);
1272 	xprt_free(xprt);
1273 }
1274 
1275 /**
1276  * xs_destroy - prepare to shutdown a transport
1277  * @xprt: doomed transport
1278  *
1279  */
1280 static void xs_destroy(struct rpc_xprt *xprt)
1281 {
1282 	struct sock_xprt *transport = container_of(xprt,
1283 			struct sock_xprt, xprt);
1284 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1285 
1286 	cancel_delayed_work_sync(&transport->connect_worker);
1287 	xs_close(xprt);
1288 	cancel_work_sync(&transport->recv_worker);
1289 	xs_xprt_free(xprt);
1290 	module_put(THIS_MODULE);
1291 }
1292 
1293 /**
1294  * xs_udp_data_read_skb - receive callback for UDP sockets
1295  * @xprt: transport
1296  * @sk: socket
1297  * @skb: skbuff
1298  *
1299  */
1300 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1301 		struct sock *sk,
1302 		struct sk_buff *skb)
1303 {
1304 	struct rpc_task *task;
1305 	struct rpc_rqst *rovr;
1306 	int repsize, copied;
1307 	u32 _xid;
1308 	__be32 *xp;
1309 
1310 	repsize = skb->len;
1311 	if (repsize < 4) {
1312 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1313 		return;
1314 	}
1315 
1316 	/* Copy the XID from the skb... */
1317 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1318 	if (xp == NULL)
1319 		return;
1320 
1321 	/* Look up and lock the request corresponding to the given XID */
1322 	spin_lock(&xprt->queue_lock);
1323 	rovr = xprt_lookup_rqst(xprt, *xp);
1324 	if (!rovr)
1325 		goto out_unlock;
1326 	xprt_pin_rqst(rovr);
1327 	xprt_update_rtt(rovr->rq_task);
1328 	spin_unlock(&xprt->queue_lock);
1329 	task = rovr->rq_task;
1330 
1331 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1332 		copied = repsize;
1333 
1334 	/* Suck it into the iovec, verify checksum if not done by hw. */
1335 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1336 		spin_lock(&xprt->queue_lock);
1337 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1338 		goto out_unpin;
1339 	}
1340 
1341 
1342 	spin_lock_bh(&xprt->transport_lock);
1343 	xprt_adjust_cwnd(xprt, task, copied);
1344 	spin_unlock_bh(&xprt->transport_lock);
1345 	spin_lock(&xprt->queue_lock);
1346 	xprt_complete_rqst(task, copied);
1347 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1348 out_unpin:
1349 	xprt_unpin_rqst(rovr);
1350  out_unlock:
1351 	spin_unlock(&xprt->queue_lock);
1352 }
1353 
1354 static void xs_udp_data_receive(struct sock_xprt *transport)
1355 {
1356 	struct sk_buff *skb;
1357 	struct sock *sk;
1358 	int err;
1359 
1360 	mutex_lock(&transport->recv_mutex);
1361 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1362 	sk = transport->inet;
1363 	if (sk == NULL)
1364 		goto out;
1365 	for (;;) {
1366 		skb = skb_recv_udp(sk, 0, 1, &err);
1367 		if (skb == NULL)
1368 			break;
1369 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1370 		consume_skb(skb);
1371 		cond_resched();
1372 	}
1373 out:
1374 	mutex_unlock(&transport->recv_mutex);
1375 }
1376 
1377 static void xs_udp_data_receive_workfn(struct work_struct *work)
1378 {
1379 	struct sock_xprt *transport =
1380 		container_of(work, struct sock_xprt, recv_worker);
1381 	xs_udp_data_receive(transport);
1382 }
1383 
1384 /**
1385  * xs_data_ready - "data ready" callback for UDP sockets
1386  * @sk: socket with data to read
1387  *
1388  */
1389 static void xs_data_ready(struct sock *sk)
1390 {
1391 	struct rpc_xprt *xprt;
1392 
1393 	read_lock_bh(&sk->sk_callback_lock);
1394 	dprintk("RPC:       xs_data_ready...\n");
1395 	xprt = xprt_from_sock(sk);
1396 	if (xprt != NULL) {
1397 		struct sock_xprt *transport = container_of(xprt,
1398 				struct sock_xprt, xprt);
1399 		transport->old_data_ready(sk);
1400 		/* Any data means we had a useful conversation, so
1401 		 * then we don't need to delay the next reconnect
1402 		 */
1403 		if (xprt->reestablish_timeout)
1404 			xprt->reestablish_timeout = 0;
1405 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1406 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1407 	}
1408 	read_unlock_bh(&sk->sk_callback_lock);
1409 }
1410 
1411 /*
1412  * Helper function to force a TCP close if the server is sending
1413  * junk and/or it has put us in CLOSE_WAIT
1414  */
1415 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1416 {
1417 	xprt_force_disconnect(xprt);
1418 }
1419 
1420 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1421 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1422 {
1423 	return PAGE_SIZE;
1424 }
1425 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1426 
1427 /**
1428  * xs_tcp_state_change - callback to handle TCP socket state changes
1429  * @sk: socket whose state has changed
1430  *
1431  */
1432 static void xs_tcp_state_change(struct sock *sk)
1433 {
1434 	struct rpc_xprt *xprt;
1435 	struct sock_xprt *transport;
1436 
1437 	read_lock_bh(&sk->sk_callback_lock);
1438 	if (!(xprt = xprt_from_sock(sk)))
1439 		goto out;
1440 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1441 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1442 			sk->sk_state, xprt_connected(xprt),
1443 			sock_flag(sk, SOCK_DEAD),
1444 			sock_flag(sk, SOCK_ZAPPED),
1445 			sk->sk_shutdown);
1446 
1447 	transport = container_of(xprt, struct sock_xprt, xprt);
1448 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1449 	switch (sk->sk_state) {
1450 	case TCP_ESTABLISHED:
1451 		spin_lock(&xprt->transport_lock);
1452 		if (!xprt_test_and_set_connected(xprt)) {
1453 			xprt->connect_cookie++;
1454 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1455 			xprt_clear_connecting(xprt);
1456 
1457 			xprt->stat.connect_count++;
1458 			xprt->stat.connect_time += (long)jiffies -
1459 						   xprt->stat.connect_start;
1460 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1461 		}
1462 		spin_unlock(&xprt->transport_lock);
1463 		break;
1464 	case TCP_FIN_WAIT1:
1465 		/* The client initiated a shutdown of the socket */
1466 		xprt->connect_cookie++;
1467 		xprt->reestablish_timeout = 0;
1468 		set_bit(XPRT_CLOSING, &xprt->state);
1469 		smp_mb__before_atomic();
1470 		clear_bit(XPRT_CONNECTED, &xprt->state);
1471 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1472 		smp_mb__after_atomic();
1473 		break;
1474 	case TCP_CLOSE_WAIT:
1475 		/* The server initiated a shutdown of the socket */
1476 		xprt->connect_cookie++;
1477 		clear_bit(XPRT_CONNECTED, &xprt->state);
1478 		xs_tcp_force_close(xprt);
1479 		/* fall through */
1480 	case TCP_CLOSING:
1481 		/*
1482 		 * If the server closed down the connection, make sure that
1483 		 * we back off before reconnecting
1484 		 */
1485 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1486 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1487 		break;
1488 	case TCP_LAST_ACK:
1489 		set_bit(XPRT_CLOSING, &xprt->state);
1490 		smp_mb__before_atomic();
1491 		clear_bit(XPRT_CONNECTED, &xprt->state);
1492 		smp_mb__after_atomic();
1493 		break;
1494 	case TCP_CLOSE:
1495 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1496 					&transport->sock_state))
1497 			xprt_clear_connecting(xprt);
1498 		clear_bit(XPRT_CLOSING, &xprt->state);
1499 		/* Trigger the socket release */
1500 		xs_tcp_force_close(xprt);
1501 	}
1502  out:
1503 	read_unlock_bh(&sk->sk_callback_lock);
1504 }
1505 
1506 static void xs_write_space(struct sock *sk)
1507 {
1508 	struct socket_wq *wq;
1509 	struct rpc_xprt *xprt;
1510 
1511 	if (!sk->sk_socket)
1512 		return;
1513 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1514 
1515 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1516 		return;
1517 	rcu_read_lock();
1518 	wq = rcu_dereference(sk->sk_wq);
1519 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1520 		goto out;
1521 
1522 	if (xprt_write_space(xprt))
1523 		sk->sk_write_pending--;
1524 out:
1525 	rcu_read_unlock();
1526 }
1527 
1528 /**
1529  * xs_udp_write_space - callback invoked when socket buffer space
1530  *                             becomes available
1531  * @sk: socket whose state has changed
1532  *
1533  * Called when more output buffer space is available for this socket.
1534  * We try not to wake our writers until they can make "significant"
1535  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1536  * with a bunch of small requests.
1537  */
1538 static void xs_udp_write_space(struct sock *sk)
1539 {
1540 	read_lock_bh(&sk->sk_callback_lock);
1541 
1542 	/* from net/core/sock.c:sock_def_write_space */
1543 	if (sock_writeable(sk))
1544 		xs_write_space(sk);
1545 
1546 	read_unlock_bh(&sk->sk_callback_lock);
1547 }
1548 
1549 /**
1550  * xs_tcp_write_space - callback invoked when socket buffer space
1551  *                             becomes available
1552  * @sk: socket whose state has changed
1553  *
1554  * Called when more output buffer space is available for this socket.
1555  * We try not to wake our writers until they can make "significant"
1556  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1557  * with a bunch of small requests.
1558  */
1559 static void xs_tcp_write_space(struct sock *sk)
1560 {
1561 	read_lock_bh(&sk->sk_callback_lock);
1562 
1563 	/* from net/core/stream.c:sk_stream_write_space */
1564 	if (sk_stream_is_writeable(sk))
1565 		xs_write_space(sk);
1566 
1567 	read_unlock_bh(&sk->sk_callback_lock);
1568 }
1569 
1570 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1571 {
1572 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1573 	struct sock *sk = transport->inet;
1574 
1575 	if (transport->rcvsize) {
1576 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1577 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1578 	}
1579 	if (transport->sndsize) {
1580 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1581 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1582 		sk->sk_write_space(sk);
1583 	}
1584 }
1585 
1586 /**
1587  * xs_udp_set_buffer_size - set send and receive limits
1588  * @xprt: generic transport
1589  * @sndsize: requested size of send buffer, in bytes
1590  * @rcvsize: requested size of receive buffer, in bytes
1591  *
1592  * Set socket send and receive buffer size limits.
1593  */
1594 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1595 {
1596 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1597 
1598 	transport->sndsize = 0;
1599 	if (sndsize)
1600 		transport->sndsize = sndsize + 1024;
1601 	transport->rcvsize = 0;
1602 	if (rcvsize)
1603 		transport->rcvsize = rcvsize + 1024;
1604 
1605 	xs_udp_do_set_buffer_size(xprt);
1606 }
1607 
1608 /**
1609  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1610  * @xprt: controlling transport
1611  * @task: task that timed out
1612  *
1613  * Adjust the congestion window after a retransmit timeout has occurred.
1614  */
1615 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1616 {
1617 	spin_lock_bh(&xprt->transport_lock);
1618 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1619 	spin_unlock_bh(&xprt->transport_lock);
1620 }
1621 
1622 static int xs_get_random_port(void)
1623 {
1624 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1625 	unsigned short range;
1626 	unsigned short rand;
1627 
1628 	if (max < min)
1629 		return -EADDRINUSE;
1630 	range = max - min + 1;
1631 	rand = (unsigned short) prandom_u32() % range;
1632 	return rand + min;
1633 }
1634 
1635 /**
1636  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1637  * @sock: socket
1638  *
1639  * Note that this function has to be called on all sockets that share the
1640  * same port, and it must be called before binding.
1641  */
1642 static void xs_sock_set_reuseport(struct socket *sock)
1643 {
1644 	int opt = 1;
1645 
1646 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1647 			(char *)&opt, sizeof(opt));
1648 }
1649 
1650 static unsigned short xs_sock_getport(struct socket *sock)
1651 {
1652 	struct sockaddr_storage buf;
1653 	unsigned short port = 0;
1654 
1655 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1656 		goto out;
1657 	switch (buf.ss_family) {
1658 	case AF_INET6:
1659 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1660 		break;
1661 	case AF_INET:
1662 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1663 	}
1664 out:
1665 	return port;
1666 }
1667 
1668 /**
1669  * xs_set_port - reset the port number in the remote endpoint address
1670  * @xprt: generic transport
1671  * @port: new port number
1672  *
1673  */
1674 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1675 {
1676 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1677 
1678 	rpc_set_port(xs_addr(xprt), port);
1679 	xs_update_peer_port(xprt);
1680 }
1681 
1682 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1683 {
1684 	if (transport->srcport == 0)
1685 		transport->srcport = xs_sock_getport(sock);
1686 }
1687 
1688 static int xs_get_srcport(struct sock_xprt *transport)
1689 {
1690 	int port = transport->srcport;
1691 
1692 	if (port == 0 && transport->xprt.resvport)
1693 		port = xs_get_random_port();
1694 	return port;
1695 }
1696 
1697 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1698 {
1699 	if (transport->srcport != 0)
1700 		transport->srcport = 0;
1701 	if (!transport->xprt.resvport)
1702 		return 0;
1703 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1704 		return xprt_max_resvport;
1705 	return --port;
1706 }
1707 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1708 {
1709 	struct sockaddr_storage myaddr;
1710 	int err, nloop = 0;
1711 	int port = xs_get_srcport(transport);
1712 	unsigned short last;
1713 
1714 	/*
1715 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1716 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1717 	 * port selection happen implicitly when the socket is used
1718 	 * (for example at connect time).
1719 	 *
1720 	 * This ensures that we can continue to establish TCP
1721 	 * connections even when all local ephemeral ports are already
1722 	 * a part of some TCP connection.  This makes no difference
1723 	 * for UDP sockets, but also doens't harm them.
1724 	 *
1725 	 * If we're asking for any reserved port (i.e. port == 0 &&
1726 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1727 	 * ensure that port is non-zero and we will bind as needed.
1728 	 */
1729 	if (port <= 0)
1730 		return port;
1731 
1732 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1733 	do {
1734 		rpc_set_port((struct sockaddr *)&myaddr, port);
1735 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1736 				transport->xprt.addrlen);
1737 		if (err == 0) {
1738 			transport->srcport = port;
1739 			break;
1740 		}
1741 		last = port;
1742 		port = xs_next_srcport(transport, port);
1743 		if (port > last)
1744 			nloop++;
1745 	} while (err == -EADDRINUSE && nloop != 2);
1746 
1747 	if (myaddr.ss_family == AF_INET)
1748 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1749 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1750 				port, err ? "failed" : "ok", err);
1751 	else
1752 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1753 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1754 				port, err ? "failed" : "ok", err);
1755 	return err;
1756 }
1757 
1758 /*
1759  * We don't support autobind on AF_LOCAL sockets
1760  */
1761 static void xs_local_rpcbind(struct rpc_task *task)
1762 {
1763 	xprt_set_bound(task->tk_xprt);
1764 }
1765 
1766 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1767 {
1768 }
1769 
1770 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1771 static struct lock_class_key xs_key[2];
1772 static struct lock_class_key xs_slock_key[2];
1773 
1774 static inline void xs_reclassify_socketu(struct socket *sock)
1775 {
1776 	struct sock *sk = sock->sk;
1777 
1778 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1779 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1780 }
1781 
1782 static inline void xs_reclassify_socket4(struct socket *sock)
1783 {
1784 	struct sock *sk = sock->sk;
1785 
1786 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1787 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1788 }
1789 
1790 static inline void xs_reclassify_socket6(struct socket *sock)
1791 {
1792 	struct sock *sk = sock->sk;
1793 
1794 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1795 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1796 }
1797 
1798 static inline void xs_reclassify_socket(int family, struct socket *sock)
1799 {
1800 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1801 		return;
1802 
1803 	switch (family) {
1804 	case AF_LOCAL:
1805 		xs_reclassify_socketu(sock);
1806 		break;
1807 	case AF_INET:
1808 		xs_reclassify_socket4(sock);
1809 		break;
1810 	case AF_INET6:
1811 		xs_reclassify_socket6(sock);
1812 		break;
1813 	}
1814 }
1815 #else
1816 static inline void xs_reclassify_socket(int family, struct socket *sock)
1817 {
1818 }
1819 #endif
1820 
1821 static void xs_dummy_setup_socket(struct work_struct *work)
1822 {
1823 }
1824 
1825 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1826 		struct sock_xprt *transport, int family, int type,
1827 		int protocol, bool reuseport)
1828 {
1829 	struct socket *sock;
1830 	int err;
1831 
1832 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1833 	if (err < 0) {
1834 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1835 				protocol, -err);
1836 		goto out;
1837 	}
1838 	xs_reclassify_socket(family, sock);
1839 
1840 	if (reuseport)
1841 		xs_sock_set_reuseport(sock);
1842 
1843 	err = xs_bind(transport, sock);
1844 	if (err) {
1845 		sock_release(sock);
1846 		goto out;
1847 	}
1848 
1849 	return sock;
1850 out:
1851 	return ERR_PTR(err);
1852 }
1853 
1854 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1855 				      struct socket *sock)
1856 {
1857 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1858 									xprt);
1859 
1860 	if (!transport->inet) {
1861 		struct sock *sk = sock->sk;
1862 
1863 		write_lock_bh(&sk->sk_callback_lock);
1864 
1865 		xs_save_old_callbacks(transport, sk);
1866 
1867 		sk->sk_user_data = xprt;
1868 		sk->sk_data_ready = xs_data_ready;
1869 		sk->sk_write_space = xs_udp_write_space;
1870 		sock_set_flag(sk, SOCK_FASYNC);
1871 		sk->sk_error_report = xs_error_report;
1872 		sk->sk_allocation = GFP_NOIO;
1873 
1874 		xprt_clear_connected(xprt);
1875 
1876 		/* Reset to new socket */
1877 		transport->sock = sock;
1878 		transport->inet = sk;
1879 
1880 		write_unlock_bh(&sk->sk_callback_lock);
1881 	}
1882 
1883 	xs_stream_reset_connect(transport);
1884 
1885 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1886 }
1887 
1888 /**
1889  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1890  * @transport: socket transport to connect
1891  */
1892 static int xs_local_setup_socket(struct sock_xprt *transport)
1893 {
1894 	struct rpc_xprt *xprt = &transport->xprt;
1895 	struct socket *sock;
1896 	int status = -EIO;
1897 
1898 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1899 					SOCK_STREAM, 0, &sock, 1);
1900 	if (status < 0) {
1901 		dprintk("RPC:       can't create AF_LOCAL "
1902 			"transport socket (%d).\n", -status);
1903 		goto out;
1904 	}
1905 	xs_reclassify_socket(AF_LOCAL, sock);
1906 
1907 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1908 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1909 
1910 	status = xs_local_finish_connecting(xprt, sock);
1911 	trace_rpc_socket_connect(xprt, sock, status);
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->stat.connect_count++;
1917 		xprt->stat.connect_time += (long)jiffies -
1918 					   xprt->stat.connect_start;
1919 		xprt_set_connected(xprt);
1920 	case -ENOBUFS:
1921 		break;
1922 	case -ENOENT:
1923 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1924 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1925 		break;
1926 	case -ECONNREFUSED:
1927 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1928 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1929 		break;
1930 	default:
1931 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1932 				__func__, -status,
1933 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1934 	}
1935 
1936 out:
1937 	xprt_clear_connecting(xprt);
1938 	xprt_wake_pending_tasks(xprt, status);
1939 	return status;
1940 }
1941 
1942 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1943 {
1944 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1945 	int ret;
1946 
1947 	 if (RPC_IS_ASYNC(task)) {
1948 		/*
1949 		 * We want the AF_LOCAL connect to be resolved in the
1950 		 * filesystem namespace of the process making the rpc
1951 		 * call.  Thus we connect synchronously.
1952 		 *
1953 		 * If we want to support asynchronous AF_LOCAL calls,
1954 		 * we'll need to figure out how to pass a namespace to
1955 		 * connect.
1956 		 */
1957 		rpc_exit(task, -ENOTCONN);
1958 		return;
1959 	}
1960 	ret = xs_local_setup_socket(transport);
1961 	if (ret && !RPC_IS_SOFTCONN(task))
1962 		msleep_interruptible(15000);
1963 }
1964 
1965 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1966 /*
1967  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1968  * know that we have exclusive access to the socket), to guard against
1969  * races with xs_reset_transport.
1970  */
1971 static void xs_set_memalloc(struct rpc_xprt *xprt)
1972 {
1973 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1974 			xprt);
1975 
1976 	/*
1977 	 * If there's no sock, then we have nothing to set. The
1978 	 * reconnecting process will get it for us.
1979 	 */
1980 	if (!transport->inet)
1981 		return;
1982 	if (atomic_read(&xprt->swapper))
1983 		sk_set_memalloc(transport->inet);
1984 }
1985 
1986 /**
1987  * xs_enable_swap - Tag this transport as being used for swap.
1988  * @xprt: transport to tag
1989  *
1990  * Take a reference to this transport on behalf of the rpc_clnt, and
1991  * optionally mark it for swapping if it wasn't already.
1992  */
1993 static int
1994 xs_enable_swap(struct rpc_xprt *xprt)
1995 {
1996 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1997 
1998 	if (atomic_inc_return(&xprt->swapper) != 1)
1999 		return 0;
2000 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2001 		return -ERESTARTSYS;
2002 	if (xs->inet)
2003 		sk_set_memalloc(xs->inet);
2004 	xprt_release_xprt(xprt, NULL);
2005 	return 0;
2006 }
2007 
2008 /**
2009  * xs_disable_swap - Untag this transport as being used for swap.
2010  * @xprt: transport to tag
2011  *
2012  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2013  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2014  */
2015 static void
2016 xs_disable_swap(struct rpc_xprt *xprt)
2017 {
2018 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2019 
2020 	if (!atomic_dec_and_test(&xprt->swapper))
2021 		return;
2022 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2023 		return;
2024 	if (xs->inet)
2025 		sk_clear_memalloc(xs->inet);
2026 	xprt_release_xprt(xprt, NULL);
2027 }
2028 #else
2029 static void xs_set_memalloc(struct rpc_xprt *xprt)
2030 {
2031 }
2032 
2033 static int
2034 xs_enable_swap(struct rpc_xprt *xprt)
2035 {
2036 	return -EINVAL;
2037 }
2038 
2039 static void
2040 xs_disable_swap(struct rpc_xprt *xprt)
2041 {
2042 }
2043 #endif
2044 
2045 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2046 {
2047 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
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_data_ready;
2058 		sk->sk_write_space = xs_udp_write_space;
2059 		sock_set_flag(sk, SOCK_FASYNC);
2060 		sk->sk_allocation = GFP_NOIO;
2061 
2062 		xprt_set_connected(xprt);
2063 
2064 		/* Reset to new socket */
2065 		transport->sock = sock;
2066 		transport->inet = sk;
2067 
2068 		xs_set_memalloc(xprt);
2069 
2070 		write_unlock_bh(&sk->sk_callback_lock);
2071 	}
2072 	xs_udp_do_set_buffer_size(xprt);
2073 
2074 	xprt->stat.connect_start = jiffies;
2075 }
2076 
2077 static void xs_udp_setup_socket(struct work_struct *work)
2078 {
2079 	struct sock_xprt *transport =
2080 		container_of(work, struct sock_xprt, connect_worker.work);
2081 	struct rpc_xprt *xprt = &transport->xprt;
2082 	struct socket *sock;
2083 	int status = -EIO;
2084 
2085 	sock = xs_create_sock(xprt, transport,
2086 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2087 			IPPROTO_UDP, false);
2088 	if (IS_ERR(sock))
2089 		goto out;
2090 
2091 	dprintk("RPC:       worker connecting xprt %p via %s to "
2092 				"%s (port %s)\n", xprt,
2093 			xprt->address_strings[RPC_DISPLAY_PROTO],
2094 			xprt->address_strings[RPC_DISPLAY_ADDR],
2095 			xprt->address_strings[RPC_DISPLAY_PORT]);
2096 
2097 	xs_udp_finish_connecting(xprt, sock);
2098 	trace_rpc_socket_connect(xprt, sock, 0);
2099 	status = 0;
2100 out:
2101 	xprt_clear_connecting(xprt);
2102 	xprt_unlock_connect(xprt, transport);
2103 	xprt_wake_pending_tasks(xprt, status);
2104 }
2105 
2106 /**
2107  * xs_tcp_shutdown - gracefully shut down a TCP socket
2108  * @xprt: transport
2109  *
2110  * Initiates a graceful shutdown of the TCP socket by calling the
2111  * equivalent of shutdown(SHUT_RDWR);
2112  */
2113 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2114 {
2115 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2116 	struct socket *sock = transport->sock;
2117 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2118 
2119 	if (sock == NULL)
2120 		return;
2121 	switch (skst) {
2122 	default:
2123 		kernel_sock_shutdown(sock, SHUT_RDWR);
2124 		trace_rpc_socket_shutdown(xprt, sock);
2125 		break;
2126 	case TCP_CLOSE:
2127 	case TCP_TIME_WAIT:
2128 		xs_reset_transport(transport);
2129 	}
2130 }
2131 
2132 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2133 		struct socket *sock)
2134 {
2135 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2136 	unsigned int keepidle;
2137 	unsigned int keepcnt;
2138 	unsigned int opt_on = 1;
2139 	unsigned int timeo;
2140 
2141 	spin_lock_bh(&xprt->transport_lock);
2142 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2143 	keepcnt = xprt->timeout->to_retries + 1;
2144 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2145 		(xprt->timeout->to_retries + 1);
2146 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2147 	spin_unlock_bh(&xprt->transport_lock);
2148 
2149 	/* TCP Keepalive options */
2150 	kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2151 			(char *)&opt_on, sizeof(opt_on));
2152 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2153 			(char *)&keepidle, sizeof(keepidle));
2154 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2155 			(char *)&keepidle, sizeof(keepidle));
2156 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2157 			(char *)&keepcnt, sizeof(keepcnt));
2158 
2159 	/* TCP user timeout (see RFC5482) */
2160 	kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2161 			(char *)&timeo, sizeof(timeo));
2162 }
2163 
2164 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2165 		unsigned long connect_timeout,
2166 		unsigned long reconnect_timeout)
2167 {
2168 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2169 	struct rpc_timeout to;
2170 	unsigned long initval;
2171 
2172 	spin_lock_bh(&xprt->transport_lock);
2173 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2174 		xprt->max_reconnect_timeout = reconnect_timeout;
2175 	if (connect_timeout < xprt->connect_timeout) {
2176 		memcpy(&to, xprt->timeout, sizeof(to));
2177 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2178 		/* Arbitrary lower limit */
2179 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2180 			initval = XS_TCP_INIT_REEST_TO << 1;
2181 		to.to_initval = initval;
2182 		to.to_maxval = initval;
2183 		memcpy(&transport->tcp_timeout, &to,
2184 				sizeof(transport->tcp_timeout));
2185 		xprt->timeout = &transport->tcp_timeout;
2186 		xprt->connect_timeout = connect_timeout;
2187 	}
2188 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2189 	spin_unlock_bh(&xprt->transport_lock);
2190 }
2191 
2192 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2193 {
2194 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2195 	int ret = -ENOTCONN;
2196 
2197 	if (!transport->inet) {
2198 		struct sock *sk = sock->sk;
2199 		unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2200 
2201 		/* Avoid temporary address, they are bad for long-lived
2202 		 * connections such as NFS mounts.
2203 		 * RFC4941, section 3.6 suggests that:
2204 		 *    Individual applications, which have specific
2205 		 *    knowledge about the normal duration of connections,
2206 		 *    MAY override this as appropriate.
2207 		 */
2208 		kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2209 				(char *)&addr_pref, sizeof(addr_pref));
2210 
2211 		xs_tcp_set_socket_timeouts(xprt, sock);
2212 
2213 		write_lock_bh(&sk->sk_callback_lock);
2214 
2215 		xs_save_old_callbacks(transport, sk);
2216 
2217 		sk->sk_user_data = xprt;
2218 		sk->sk_data_ready = xs_data_ready;
2219 		sk->sk_state_change = xs_tcp_state_change;
2220 		sk->sk_write_space = xs_tcp_write_space;
2221 		sock_set_flag(sk, SOCK_FASYNC);
2222 		sk->sk_error_report = xs_error_report;
2223 		sk->sk_allocation = GFP_NOIO;
2224 
2225 		/* socket options */
2226 		sock_reset_flag(sk, SOCK_LINGER);
2227 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2228 
2229 		xprt_clear_connected(xprt);
2230 
2231 		/* Reset to new socket */
2232 		transport->sock = sock;
2233 		transport->inet = sk;
2234 
2235 		write_unlock_bh(&sk->sk_callback_lock);
2236 	}
2237 
2238 	if (!xprt_bound(xprt))
2239 		goto out;
2240 
2241 	xs_set_memalloc(xprt);
2242 
2243 	/* Reset TCP record info */
2244 	xs_stream_reset_connect(transport);
2245 
2246 	/* Tell the socket layer to start connecting... */
2247 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2248 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2249 	switch (ret) {
2250 	case 0:
2251 		xs_set_srcport(transport, sock);
2252 		/* fall through */
2253 	case -EINPROGRESS:
2254 		/* SYN_SENT! */
2255 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2256 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2257 		break;
2258 	case -EADDRNOTAVAIL:
2259 		/* Source port number is unavailable. Try a new one! */
2260 		transport->srcport = 0;
2261 	}
2262 out:
2263 	return ret;
2264 }
2265 
2266 /**
2267  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2268  * @work: queued work item
2269  *
2270  * Invoked by a work queue tasklet.
2271  */
2272 static void xs_tcp_setup_socket(struct work_struct *work)
2273 {
2274 	struct sock_xprt *transport =
2275 		container_of(work, struct sock_xprt, connect_worker.work);
2276 	struct socket *sock = transport->sock;
2277 	struct rpc_xprt *xprt = &transport->xprt;
2278 	int status = -EIO;
2279 
2280 	if (!sock) {
2281 		sock = xs_create_sock(xprt, transport,
2282 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2283 				IPPROTO_TCP, true);
2284 		if (IS_ERR(sock)) {
2285 			status = PTR_ERR(sock);
2286 			goto out;
2287 		}
2288 	}
2289 
2290 	dprintk("RPC:       worker connecting xprt %p via %s to "
2291 				"%s (port %s)\n", xprt,
2292 			xprt->address_strings[RPC_DISPLAY_PROTO],
2293 			xprt->address_strings[RPC_DISPLAY_ADDR],
2294 			xprt->address_strings[RPC_DISPLAY_PORT]);
2295 
2296 	status = xs_tcp_finish_connecting(xprt, sock);
2297 	trace_rpc_socket_connect(xprt, sock, status);
2298 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2299 			xprt, -status, xprt_connected(xprt),
2300 			sock->sk->sk_state);
2301 	switch (status) {
2302 	default:
2303 		printk("%s: connect returned unhandled error %d\n",
2304 			__func__, status);
2305 		/* fall through */
2306 	case -EADDRNOTAVAIL:
2307 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2308 		 * and retry
2309 		 */
2310 		xs_tcp_force_close(xprt);
2311 		break;
2312 	case 0:
2313 	case -EINPROGRESS:
2314 	case -EALREADY:
2315 		xprt_unlock_connect(xprt, transport);
2316 		return;
2317 	case -EINVAL:
2318 		/* Happens, for instance, if the user specified a link
2319 		 * local IPv6 address without a scope-id.
2320 		 */
2321 	case -ECONNREFUSED:
2322 	case -ECONNRESET:
2323 	case -ENETDOWN:
2324 	case -ENETUNREACH:
2325 	case -EHOSTUNREACH:
2326 	case -EADDRINUSE:
2327 	case -ENOBUFS:
2328 		/*
2329 		 * xs_tcp_force_close() wakes tasks with -EIO.
2330 		 * We need to wake them first to ensure the
2331 		 * correct error code.
2332 		 */
2333 		xprt_wake_pending_tasks(xprt, status);
2334 		xs_tcp_force_close(xprt);
2335 		goto out;
2336 	}
2337 	status = -EAGAIN;
2338 out:
2339 	xprt_clear_connecting(xprt);
2340 	xprt_unlock_connect(xprt, transport);
2341 	xprt_wake_pending_tasks(xprt, status);
2342 }
2343 
2344 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2345 {
2346 	unsigned long start, now = jiffies;
2347 
2348 	start = xprt->stat.connect_start + xprt->reestablish_timeout;
2349 	if (time_after(start, now))
2350 		return start - now;
2351 	return 0;
2352 }
2353 
2354 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2355 {
2356 	xprt->reestablish_timeout <<= 1;
2357 	if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2358 		xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2359 	if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2360 		xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2361 }
2362 
2363 /**
2364  * xs_connect - connect a socket to a remote endpoint
2365  * @xprt: pointer to transport structure
2366  * @task: address of RPC task that manages state of connect request
2367  *
2368  * TCP: If the remote end dropped the connection, delay reconnecting.
2369  *
2370  * UDP socket connects are synchronous, but we use a work queue anyway
2371  * to guarantee that even unprivileged user processes can set up a
2372  * socket on a privileged port.
2373  *
2374  * If a UDP socket connect fails, the delay behavior here prevents
2375  * retry floods (hard mounts).
2376  */
2377 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2378 {
2379 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2380 	unsigned long delay = 0;
2381 
2382 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2383 
2384 	if (transport->sock != NULL) {
2385 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2386 				"seconds\n",
2387 				xprt, xprt->reestablish_timeout / HZ);
2388 
2389 		/* Start by resetting any existing state */
2390 		xs_reset_transport(transport);
2391 
2392 		delay = xs_reconnect_delay(xprt);
2393 		xs_reconnect_backoff(xprt);
2394 
2395 	} else
2396 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2397 
2398 	queue_delayed_work(xprtiod_workqueue,
2399 			&transport->connect_worker,
2400 			delay);
2401 }
2402 
2403 /**
2404  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2405  * @xprt: rpc_xprt struct containing statistics
2406  * @seq: output file
2407  *
2408  */
2409 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2410 {
2411 	long idle_time = 0;
2412 
2413 	if (xprt_connected(xprt))
2414 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2415 
2416 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2417 			"%llu %llu %lu %llu %llu\n",
2418 			xprt->stat.bind_count,
2419 			xprt->stat.connect_count,
2420 			xprt->stat.connect_time / HZ,
2421 			idle_time,
2422 			xprt->stat.sends,
2423 			xprt->stat.recvs,
2424 			xprt->stat.bad_xids,
2425 			xprt->stat.req_u,
2426 			xprt->stat.bklog_u,
2427 			xprt->stat.max_slots,
2428 			xprt->stat.sending_u,
2429 			xprt->stat.pending_u);
2430 }
2431 
2432 /**
2433  * xs_udp_print_stats - display UDP socket-specifc stats
2434  * @xprt: rpc_xprt struct containing statistics
2435  * @seq: output file
2436  *
2437  */
2438 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2439 {
2440 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2441 
2442 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2443 			"%lu %llu %llu\n",
2444 			transport->srcport,
2445 			xprt->stat.bind_count,
2446 			xprt->stat.sends,
2447 			xprt->stat.recvs,
2448 			xprt->stat.bad_xids,
2449 			xprt->stat.req_u,
2450 			xprt->stat.bklog_u,
2451 			xprt->stat.max_slots,
2452 			xprt->stat.sending_u,
2453 			xprt->stat.pending_u);
2454 }
2455 
2456 /**
2457  * xs_tcp_print_stats - display TCP socket-specifc stats
2458  * @xprt: rpc_xprt struct containing statistics
2459  * @seq: output file
2460  *
2461  */
2462 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2463 {
2464 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2465 	long idle_time = 0;
2466 
2467 	if (xprt_connected(xprt))
2468 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2469 
2470 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2471 			"%llu %llu %lu %llu %llu\n",
2472 			transport->srcport,
2473 			xprt->stat.bind_count,
2474 			xprt->stat.connect_count,
2475 			xprt->stat.connect_time / HZ,
2476 			idle_time,
2477 			xprt->stat.sends,
2478 			xprt->stat.recvs,
2479 			xprt->stat.bad_xids,
2480 			xprt->stat.req_u,
2481 			xprt->stat.bklog_u,
2482 			xprt->stat.max_slots,
2483 			xprt->stat.sending_u,
2484 			xprt->stat.pending_u);
2485 }
2486 
2487 /*
2488  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2489  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2490  * to use the server side send routines.
2491  */
2492 static int bc_malloc(struct rpc_task *task)
2493 {
2494 	struct rpc_rqst *rqst = task->tk_rqstp;
2495 	size_t size = rqst->rq_callsize;
2496 	struct page *page;
2497 	struct rpc_buffer *buf;
2498 
2499 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2500 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2501 			  size);
2502 		return -EINVAL;
2503 	}
2504 
2505 	page = alloc_page(GFP_KERNEL);
2506 	if (!page)
2507 		return -ENOMEM;
2508 
2509 	buf = page_address(page);
2510 	buf->len = PAGE_SIZE;
2511 
2512 	rqst->rq_buffer = buf->data;
2513 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2514 	return 0;
2515 }
2516 
2517 /*
2518  * Free the space allocated in the bc_alloc routine
2519  */
2520 static void bc_free(struct rpc_task *task)
2521 {
2522 	void *buffer = task->tk_rqstp->rq_buffer;
2523 	struct rpc_buffer *buf;
2524 
2525 	buf = container_of(buffer, struct rpc_buffer, data);
2526 	free_page((unsigned long)buf);
2527 }
2528 
2529 /*
2530  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2531  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2532  */
2533 static int bc_sendto(struct rpc_rqst *req)
2534 {
2535 	int len;
2536 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2537 	struct rpc_xprt *xprt = req->rq_xprt;
2538 	struct sock_xprt *transport =
2539 				container_of(xprt, struct sock_xprt, xprt);
2540 	struct socket *sock = transport->sock;
2541 	unsigned long headoff;
2542 	unsigned long tailoff;
2543 
2544 	xs_encode_stream_record_marker(xbufp);
2545 
2546 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2547 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2548 	len = svc_send_common(sock, xbufp,
2549 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2550 			      xbufp->tail[0].iov_base, tailoff);
2551 
2552 	if (len != xbufp->len) {
2553 		printk(KERN_NOTICE "Error sending entire callback!\n");
2554 		len = -EAGAIN;
2555 	}
2556 
2557 	return len;
2558 }
2559 
2560 /*
2561  * The send routine. Borrows from svc_send
2562  */
2563 static int bc_send_request(struct rpc_rqst *req)
2564 {
2565 	struct svc_xprt	*xprt;
2566 	int len;
2567 
2568 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2569 	/*
2570 	 * Get the server socket associated with this callback xprt
2571 	 */
2572 	xprt = req->rq_xprt->bc_xprt;
2573 
2574 	/*
2575 	 * Grab the mutex to serialize data as the connection is shared
2576 	 * with the fore channel
2577 	 */
2578 	mutex_lock(&xprt->xpt_mutex);
2579 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2580 		len = -ENOTCONN;
2581 	else
2582 		len = bc_sendto(req);
2583 	mutex_unlock(&xprt->xpt_mutex);
2584 
2585 	if (len > 0)
2586 		len = 0;
2587 
2588 	return len;
2589 }
2590 
2591 /*
2592  * The close routine. Since this is client initiated, we do nothing
2593  */
2594 
2595 static void bc_close(struct rpc_xprt *xprt)
2596 {
2597 }
2598 
2599 /*
2600  * The xprt destroy routine. Again, because this connection is client
2601  * initiated, we do nothing
2602  */
2603 
2604 static void bc_destroy(struct rpc_xprt *xprt)
2605 {
2606 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2607 
2608 	xs_xprt_free(xprt);
2609 	module_put(THIS_MODULE);
2610 }
2611 
2612 static const struct rpc_xprt_ops xs_local_ops = {
2613 	.reserve_xprt		= xprt_reserve_xprt,
2614 	.release_xprt		= xprt_release_xprt,
2615 	.alloc_slot		= xprt_alloc_slot,
2616 	.free_slot		= xprt_free_slot,
2617 	.rpcbind		= xs_local_rpcbind,
2618 	.set_port		= xs_local_set_port,
2619 	.connect		= xs_local_connect,
2620 	.buf_alloc		= rpc_malloc,
2621 	.buf_free		= rpc_free,
2622 	.prepare_request	= xs_stream_prepare_request,
2623 	.send_request		= xs_local_send_request,
2624 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2625 	.close			= xs_close,
2626 	.destroy		= xs_destroy,
2627 	.print_stats		= xs_local_print_stats,
2628 	.enable_swap		= xs_enable_swap,
2629 	.disable_swap		= xs_disable_swap,
2630 };
2631 
2632 static const struct rpc_xprt_ops xs_udp_ops = {
2633 	.set_buffer_size	= xs_udp_set_buffer_size,
2634 	.reserve_xprt		= xprt_reserve_xprt_cong,
2635 	.release_xprt		= xprt_release_xprt_cong,
2636 	.alloc_slot		= xprt_alloc_slot,
2637 	.free_slot		= xprt_free_slot,
2638 	.rpcbind		= rpcb_getport_async,
2639 	.set_port		= xs_set_port,
2640 	.connect		= xs_connect,
2641 	.buf_alloc		= rpc_malloc,
2642 	.buf_free		= rpc_free,
2643 	.send_request		= xs_udp_send_request,
2644 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2645 	.timer			= xs_udp_timer,
2646 	.release_request	= xprt_release_rqst_cong,
2647 	.close			= xs_close,
2648 	.destroy		= xs_destroy,
2649 	.print_stats		= xs_udp_print_stats,
2650 	.enable_swap		= xs_enable_swap,
2651 	.disable_swap		= xs_disable_swap,
2652 	.inject_disconnect	= xs_inject_disconnect,
2653 };
2654 
2655 static const struct rpc_xprt_ops xs_tcp_ops = {
2656 	.reserve_xprt		= xprt_reserve_xprt,
2657 	.release_xprt		= xprt_release_xprt,
2658 	.alloc_slot		= xprt_alloc_slot,
2659 	.free_slot		= xprt_free_slot,
2660 	.rpcbind		= rpcb_getport_async,
2661 	.set_port		= xs_set_port,
2662 	.connect		= xs_connect,
2663 	.buf_alloc		= rpc_malloc,
2664 	.buf_free		= rpc_free,
2665 	.prepare_request	= xs_stream_prepare_request,
2666 	.send_request		= xs_tcp_send_request,
2667 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2668 	.close			= xs_tcp_shutdown,
2669 	.destroy		= xs_destroy,
2670 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2671 	.print_stats		= xs_tcp_print_stats,
2672 	.enable_swap		= xs_enable_swap,
2673 	.disable_swap		= xs_disable_swap,
2674 	.inject_disconnect	= xs_inject_disconnect,
2675 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2676 	.bc_setup		= xprt_setup_bc,
2677 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2678 	.bc_free_rqst		= xprt_free_bc_rqst,
2679 	.bc_destroy		= xprt_destroy_bc,
2680 #endif
2681 };
2682 
2683 /*
2684  * The rpc_xprt_ops for the server backchannel
2685  */
2686 
2687 static const struct rpc_xprt_ops bc_tcp_ops = {
2688 	.reserve_xprt		= xprt_reserve_xprt,
2689 	.release_xprt		= xprt_release_xprt,
2690 	.alloc_slot		= xprt_alloc_slot,
2691 	.free_slot		= xprt_free_slot,
2692 	.buf_alloc		= bc_malloc,
2693 	.buf_free		= bc_free,
2694 	.send_request		= bc_send_request,
2695 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2696 	.close			= bc_close,
2697 	.destroy		= bc_destroy,
2698 	.print_stats		= xs_tcp_print_stats,
2699 	.enable_swap		= xs_enable_swap,
2700 	.disable_swap		= xs_disable_swap,
2701 	.inject_disconnect	= xs_inject_disconnect,
2702 };
2703 
2704 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2705 {
2706 	static const struct sockaddr_in sin = {
2707 		.sin_family		= AF_INET,
2708 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2709 	};
2710 	static const struct sockaddr_in6 sin6 = {
2711 		.sin6_family		= AF_INET6,
2712 		.sin6_addr		= IN6ADDR_ANY_INIT,
2713 	};
2714 
2715 	switch (family) {
2716 	case AF_LOCAL:
2717 		break;
2718 	case AF_INET:
2719 		memcpy(sap, &sin, sizeof(sin));
2720 		break;
2721 	case AF_INET6:
2722 		memcpy(sap, &sin6, sizeof(sin6));
2723 		break;
2724 	default:
2725 		dprintk("RPC:       %s: Bad address family\n", __func__);
2726 		return -EAFNOSUPPORT;
2727 	}
2728 	return 0;
2729 }
2730 
2731 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2732 				      unsigned int slot_table_size,
2733 				      unsigned int max_slot_table_size)
2734 {
2735 	struct rpc_xprt *xprt;
2736 	struct sock_xprt *new;
2737 
2738 	if (args->addrlen > sizeof(xprt->addr)) {
2739 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2740 		return ERR_PTR(-EBADF);
2741 	}
2742 
2743 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2744 			max_slot_table_size);
2745 	if (xprt == NULL) {
2746 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2747 				"rpc_xprt\n");
2748 		return ERR_PTR(-ENOMEM);
2749 	}
2750 
2751 	new = container_of(xprt, struct sock_xprt, xprt);
2752 	mutex_init(&new->recv_mutex);
2753 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2754 	xprt->addrlen = args->addrlen;
2755 	if (args->srcaddr)
2756 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2757 	else {
2758 		int err;
2759 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2760 					(struct sockaddr *)&new->srcaddr);
2761 		if (err != 0) {
2762 			xprt_free(xprt);
2763 			return ERR_PTR(err);
2764 		}
2765 	}
2766 
2767 	return xprt;
2768 }
2769 
2770 static const struct rpc_timeout xs_local_default_timeout = {
2771 	.to_initval = 10 * HZ,
2772 	.to_maxval = 10 * HZ,
2773 	.to_retries = 2,
2774 };
2775 
2776 /**
2777  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2778  * @args: rpc transport creation arguments
2779  *
2780  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2781  */
2782 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2783 {
2784 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2785 	struct sock_xprt *transport;
2786 	struct rpc_xprt *xprt;
2787 	struct rpc_xprt *ret;
2788 
2789 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2790 			xprt_max_tcp_slot_table_entries);
2791 	if (IS_ERR(xprt))
2792 		return xprt;
2793 	transport = container_of(xprt, struct sock_xprt, xprt);
2794 
2795 	xprt->prot = 0;
2796 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2797 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2798 
2799 	xprt->bind_timeout = XS_BIND_TO;
2800 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2801 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2802 
2803 	xprt->ops = &xs_local_ops;
2804 	xprt->timeout = &xs_local_default_timeout;
2805 
2806 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2807 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2808 
2809 	switch (sun->sun_family) {
2810 	case AF_LOCAL:
2811 		if (sun->sun_path[0] != '/') {
2812 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2813 					sun->sun_path);
2814 			ret = ERR_PTR(-EINVAL);
2815 			goto out_err;
2816 		}
2817 		xprt_set_bound(xprt);
2818 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2819 		ret = ERR_PTR(xs_local_setup_socket(transport));
2820 		if (ret)
2821 			goto out_err;
2822 		break;
2823 	default:
2824 		ret = ERR_PTR(-EAFNOSUPPORT);
2825 		goto out_err;
2826 	}
2827 
2828 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2829 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2830 
2831 	if (try_module_get(THIS_MODULE))
2832 		return xprt;
2833 	ret = ERR_PTR(-EINVAL);
2834 out_err:
2835 	xs_xprt_free(xprt);
2836 	return ret;
2837 }
2838 
2839 static const struct rpc_timeout xs_udp_default_timeout = {
2840 	.to_initval = 5 * HZ,
2841 	.to_maxval = 30 * HZ,
2842 	.to_increment = 5 * HZ,
2843 	.to_retries = 5,
2844 };
2845 
2846 /**
2847  * xs_setup_udp - Set up transport to use a UDP socket
2848  * @args: rpc transport creation arguments
2849  *
2850  */
2851 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2852 {
2853 	struct sockaddr *addr = args->dstaddr;
2854 	struct rpc_xprt *xprt;
2855 	struct sock_xprt *transport;
2856 	struct rpc_xprt *ret;
2857 
2858 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2859 			xprt_udp_slot_table_entries);
2860 	if (IS_ERR(xprt))
2861 		return xprt;
2862 	transport = container_of(xprt, struct sock_xprt, xprt);
2863 
2864 	xprt->prot = IPPROTO_UDP;
2865 	xprt->tsh_size = 0;
2866 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2867 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2868 
2869 	xprt->bind_timeout = XS_BIND_TO;
2870 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2871 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2872 
2873 	xprt->ops = &xs_udp_ops;
2874 
2875 	xprt->timeout = &xs_udp_default_timeout;
2876 
2877 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2878 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2879 
2880 	switch (addr->sa_family) {
2881 	case AF_INET:
2882 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2883 			xprt_set_bound(xprt);
2884 
2885 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2886 		break;
2887 	case AF_INET6:
2888 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2889 			xprt_set_bound(xprt);
2890 
2891 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2892 		break;
2893 	default:
2894 		ret = ERR_PTR(-EAFNOSUPPORT);
2895 		goto out_err;
2896 	}
2897 
2898 	if (xprt_bound(xprt))
2899 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2900 				xprt->address_strings[RPC_DISPLAY_ADDR],
2901 				xprt->address_strings[RPC_DISPLAY_PORT],
2902 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2903 	else
2904 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2905 				xprt->address_strings[RPC_DISPLAY_ADDR],
2906 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2907 
2908 	if (try_module_get(THIS_MODULE))
2909 		return xprt;
2910 	ret = ERR_PTR(-EINVAL);
2911 out_err:
2912 	xs_xprt_free(xprt);
2913 	return ret;
2914 }
2915 
2916 static const struct rpc_timeout xs_tcp_default_timeout = {
2917 	.to_initval = 60 * HZ,
2918 	.to_maxval = 60 * HZ,
2919 	.to_retries = 2,
2920 };
2921 
2922 /**
2923  * xs_setup_tcp - Set up transport to use a TCP socket
2924  * @args: rpc transport creation arguments
2925  *
2926  */
2927 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2928 {
2929 	struct sockaddr *addr = args->dstaddr;
2930 	struct rpc_xprt *xprt;
2931 	struct sock_xprt *transport;
2932 	struct rpc_xprt *ret;
2933 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2934 
2935 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2936 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2937 
2938 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2939 			max_slot_table_size);
2940 	if (IS_ERR(xprt))
2941 		return xprt;
2942 	transport = container_of(xprt, struct sock_xprt, xprt);
2943 
2944 	xprt->prot = IPPROTO_TCP;
2945 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2946 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2947 
2948 	xprt->bind_timeout = XS_BIND_TO;
2949 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2950 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2951 
2952 	xprt->ops = &xs_tcp_ops;
2953 	xprt->timeout = &xs_tcp_default_timeout;
2954 
2955 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2956 	xprt->connect_timeout = xprt->timeout->to_initval *
2957 		(xprt->timeout->to_retries + 1);
2958 
2959 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2960 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2961 
2962 	switch (addr->sa_family) {
2963 	case AF_INET:
2964 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2965 			xprt_set_bound(xprt);
2966 
2967 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2968 		break;
2969 	case AF_INET6:
2970 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2971 			xprt_set_bound(xprt);
2972 
2973 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2974 		break;
2975 	default:
2976 		ret = ERR_PTR(-EAFNOSUPPORT);
2977 		goto out_err;
2978 	}
2979 
2980 	if (xprt_bound(xprt))
2981 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2982 				xprt->address_strings[RPC_DISPLAY_ADDR],
2983 				xprt->address_strings[RPC_DISPLAY_PORT],
2984 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2985 	else
2986 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2987 				xprt->address_strings[RPC_DISPLAY_ADDR],
2988 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2989 
2990 	if (try_module_get(THIS_MODULE))
2991 		return xprt;
2992 	ret = ERR_PTR(-EINVAL);
2993 out_err:
2994 	xs_xprt_free(xprt);
2995 	return ret;
2996 }
2997 
2998 /**
2999  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3000  * @args: rpc transport creation arguments
3001  *
3002  */
3003 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3004 {
3005 	struct sockaddr *addr = args->dstaddr;
3006 	struct rpc_xprt *xprt;
3007 	struct sock_xprt *transport;
3008 	struct svc_sock *bc_sock;
3009 	struct rpc_xprt *ret;
3010 
3011 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3012 			xprt_tcp_slot_table_entries);
3013 	if (IS_ERR(xprt))
3014 		return xprt;
3015 	transport = container_of(xprt, struct sock_xprt, xprt);
3016 
3017 	xprt->prot = IPPROTO_TCP;
3018 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3019 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3020 	xprt->timeout = &xs_tcp_default_timeout;
3021 
3022 	/* backchannel */
3023 	xprt_set_bound(xprt);
3024 	xprt->bind_timeout = 0;
3025 	xprt->reestablish_timeout = 0;
3026 	xprt->idle_timeout = 0;
3027 
3028 	xprt->ops = &bc_tcp_ops;
3029 
3030 	switch (addr->sa_family) {
3031 	case AF_INET:
3032 		xs_format_peer_addresses(xprt, "tcp",
3033 					 RPCBIND_NETID_TCP);
3034 		break;
3035 	case AF_INET6:
3036 		xs_format_peer_addresses(xprt, "tcp",
3037 				   RPCBIND_NETID_TCP6);
3038 		break;
3039 	default:
3040 		ret = ERR_PTR(-EAFNOSUPPORT);
3041 		goto out_err;
3042 	}
3043 
3044 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3045 			xprt->address_strings[RPC_DISPLAY_ADDR],
3046 			xprt->address_strings[RPC_DISPLAY_PORT],
3047 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3048 
3049 	/*
3050 	 * Once we've associated a backchannel xprt with a connection,
3051 	 * we want to keep it around as long as the connection lasts,
3052 	 * in case we need to start using it for a backchannel again;
3053 	 * this reference won't be dropped until bc_xprt is destroyed.
3054 	 */
3055 	xprt_get(xprt);
3056 	args->bc_xprt->xpt_bc_xprt = xprt;
3057 	xprt->bc_xprt = args->bc_xprt;
3058 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3059 	transport->sock = bc_sock->sk_sock;
3060 	transport->inet = bc_sock->sk_sk;
3061 
3062 	/*
3063 	 * Since we don't want connections for the backchannel, we set
3064 	 * the xprt status to connected
3065 	 */
3066 	xprt_set_connected(xprt);
3067 
3068 	if (try_module_get(THIS_MODULE))
3069 		return xprt;
3070 
3071 	args->bc_xprt->xpt_bc_xprt = NULL;
3072 	args->bc_xprt->xpt_bc_xps = NULL;
3073 	xprt_put(xprt);
3074 	ret = ERR_PTR(-EINVAL);
3075 out_err:
3076 	xs_xprt_free(xprt);
3077 	return ret;
3078 }
3079 
3080 static struct xprt_class	xs_local_transport = {
3081 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3082 	.name		= "named UNIX socket",
3083 	.owner		= THIS_MODULE,
3084 	.ident		= XPRT_TRANSPORT_LOCAL,
3085 	.setup		= xs_setup_local,
3086 };
3087 
3088 static struct xprt_class	xs_udp_transport = {
3089 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3090 	.name		= "udp",
3091 	.owner		= THIS_MODULE,
3092 	.ident		= XPRT_TRANSPORT_UDP,
3093 	.setup		= xs_setup_udp,
3094 };
3095 
3096 static struct xprt_class	xs_tcp_transport = {
3097 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3098 	.name		= "tcp",
3099 	.owner		= THIS_MODULE,
3100 	.ident		= XPRT_TRANSPORT_TCP,
3101 	.setup		= xs_setup_tcp,
3102 };
3103 
3104 static struct xprt_class	xs_bc_tcp_transport = {
3105 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3106 	.name		= "tcp NFSv4.1 backchannel",
3107 	.owner		= THIS_MODULE,
3108 	.ident		= XPRT_TRANSPORT_BC_TCP,
3109 	.setup		= xs_setup_bc_tcp,
3110 };
3111 
3112 /**
3113  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3114  *
3115  */
3116 int init_socket_xprt(void)
3117 {
3118 	if (!sunrpc_table_header)
3119 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3120 
3121 	xprt_register_transport(&xs_local_transport);
3122 	xprt_register_transport(&xs_udp_transport);
3123 	xprt_register_transport(&xs_tcp_transport);
3124 	xprt_register_transport(&xs_bc_tcp_transport);
3125 
3126 	return 0;
3127 }
3128 
3129 /**
3130  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3131  *
3132  */
3133 void cleanup_socket_xprt(void)
3134 {
3135 	if (sunrpc_table_header) {
3136 		unregister_sysctl_table(sunrpc_table_header);
3137 		sunrpc_table_header = NULL;
3138 	}
3139 
3140 	xprt_unregister_transport(&xs_local_transport);
3141 	xprt_unregister_transport(&xs_udp_transport);
3142 	xprt_unregister_transport(&xs_tcp_transport);
3143 	xprt_unregister_transport(&xs_bc_tcp_transport);
3144 }
3145 
3146 static int param_set_uint_minmax(const char *val,
3147 		const struct kernel_param *kp,
3148 		unsigned int min, unsigned int max)
3149 {
3150 	unsigned int num;
3151 	int ret;
3152 
3153 	if (!val)
3154 		return -EINVAL;
3155 	ret = kstrtouint(val, 0, &num);
3156 	if (ret)
3157 		return ret;
3158 	if (num < min || num > max)
3159 		return -EINVAL;
3160 	*((unsigned int *)kp->arg) = num;
3161 	return 0;
3162 }
3163 
3164 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3165 {
3166 	return param_set_uint_minmax(val, kp,
3167 			RPC_MIN_RESVPORT,
3168 			RPC_MAX_RESVPORT);
3169 }
3170 
3171 static const struct kernel_param_ops param_ops_portnr = {
3172 	.set = param_set_portnr,
3173 	.get = param_get_uint,
3174 };
3175 
3176 #define param_check_portnr(name, p) \
3177 	__param_check(name, p, unsigned int);
3178 
3179 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3180 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3181 
3182 static int param_set_slot_table_size(const char *val,
3183 				     const struct kernel_param *kp)
3184 {
3185 	return param_set_uint_minmax(val, kp,
3186 			RPC_MIN_SLOT_TABLE,
3187 			RPC_MAX_SLOT_TABLE);
3188 }
3189 
3190 static const struct kernel_param_ops param_ops_slot_table_size = {
3191 	.set = param_set_slot_table_size,
3192 	.get = param_get_uint,
3193 };
3194 
3195 #define param_check_slot_table_size(name, p) \
3196 	__param_check(name, p, unsigned int);
3197 
3198 static int param_set_max_slot_table_size(const char *val,
3199 				     const struct kernel_param *kp)
3200 {
3201 	return param_set_uint_minmax(val, kp,
3202 			RPC_MIN_SLOT_TABLE,
3203 			RPC_MAX_SLOT_TABLE_LIMIT);
3204 }
3205 
3206 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3207 	.set = param_set_max_slot_table_size,
3208 	.get = param_get_uint,
3209 };
3210 
3211 #define param_check_max_slot_table_size(name, p) \
3212 	__param_check(name, p, unsigned int);
3213 
3214 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3215 		   slot_table_size, 0644);
3216 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3217 		   max_slot_table_size, 0644);
3218 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3219 		   slot_table_size, 0644);
3220