xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 26781eab)
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/uio.h>
52 
53 #include <trace/events/sunrpc.h>
54 
55 #include "sunrpc.h"
56 
57 static void xs_close(struct rpc_xprt *xprt);
58 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
59 		struct socket *sock);
60 
61 /*
62  * xprtsock tunables
63  */
64 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
65 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
66 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
67 
68 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
69 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
70 
71 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
72 
73 #define XS_TCP_LINGER_TO	(15U * HZ)
74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
75 
76 /*
77  * We can register our own files under /proc/sys/sunrpc by
78  * calling register_sysctl_table() again.  The files in that
79  * directory become the union of all files registered there.
80  *
81  * We simply need to make sure that we don't collide with
82  * someone else's file names!
83  */
84 
85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
90 
91 static struct ctl_table_header *sunrpc_table_header;
92 
93 /*
94  * FIXME: changing the UDP slot table size should also resize the UDP
95  *        socket buffers for existing UDP transports
96  */
97 static struct ctl_table xs_tunables_table[] = {
98 	{
99 		.procname	= "udp_slot_table_entries",
100 		.data		= &xprt_udp_slot_table_entries,
101 		.maxlen		= sizeof(unsigned int),
102 		.mode		= 0644,
103 		.proc_handler	= proc_dointvec_minmax,
104 		.extra1		= &min_slot_table_size,
105 		.extra2		= &max_slot_table_size
106 	},
107 	{
108 		.procname	= "tcp_slot_table_entries",
109 		.data		= &xprt_tcp_slot_table_entries,
110 		.maxlen		= sizeof(unsigned int),
111 		.mode		= 0644,
112 		.proc_handler	= proc_dointvec_minmax,
113 		.extra1		= &min_slot_table_size,
114 		.extra2		= &max_slot_table_size
115 	},
116 	{
117 		.procname	= "tcp_max_slot_table_entries",
118 		.data		= &xprt_max_tcp_slot_table_entries,
119 		.maxlen		= sizeof(unsigned int),
120 		.mode		= 0644,
121 		.proc_handler	= proc_dointvec_minmax,
122 		.extra1		= &min_slot_table_size,
123 		.extra2		= &max_tcp_slot_table_limit
124 	},
125 	{
126 		.procname	= "min_resvport",
127 		.data		= &xprt_min_resvport,
128 		.maxlen		= sizeof(unsigned int),
129 		.mode		= 0644,
130 		.proc_handler	= proc_dointvec_minmax,
131 		.extra1		= &xprt_min_resvport_limit,
132 		.extra2		= &xprt_max_resvport_limit
133 	},
134 	{
135 		.procname	= "max_resvport",
136 		.data		= &xprt_max_resvport,
137 		.maxlen		= sizeof(unsigned int),
138 		.mode		= 0644,
139 		.proc_handler	= proc_dointvec_minmax,
140 		.extra1		= &xprt_min_resvport_limit,
141 		.extra2		= &xprt_max_resvport_limit
142 	},
143 	{
144 		.procname	= "tcp_fin_timeout",
145 		.data		= &xs_tcp_fin_timeout,
146 		.maxlen		= sizeof(xs_tcp_fin_timeout),
147 		.mode		= 0644,
148 		.proc_handler	= proc_dointvec_jiffies,
149 	},
150 	{ },
151 };
152 
153 static struct ctl_table sunrpc_table[] = {
154 	{
155 		.procname	= "sunrpc",
156 		.mode		= 0555,
157 		.child		= xs_tunables_table
158 	},
159 	{ },
160 };
161 
162 #endif
163 
164 /*
165  * Wait duration for a reply from the RPC portmapper.
166  */
167 #define XS_BIND_TO		(60U * HZ)
168 
169 /*
170  * Delay if a UDP socket connect error occurs.  This is most likely some
171  * kind of resource problem on the local host.
172  */
173 #define XS_UDP_REEST_TO		(2U * HZ)
174 
175 /*
176  * The reestablish timeout allows clients to delay for a bit before attempting
177  * to reconnect to a server that just dropped our connection.
178  *
179  * We implement an exponential backoff when trying to reestablish a TCP
180  * transport connection with the server.  Some servers like to drop a TCP
181  * connection when they are overworked, so we start with a short timeout and
182  * increase over time if the server is down or not responding.
183  */
184 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
185 
186 /*
187  * TCP idle timeout; client drops the transport socket if it is idle
188  * for this long.  Note that we also timeout UDP sockets to prevent
189  * holding port numbers when there is no RPC traffic.
190  */
191 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
192 
193 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
194 # undef  RPC_DEBUG_DATA
195 # define RPCDBG_FACILITY	RPCDBG_TRANS
196 #endif
197 
198 #ifdef RPC_DEBUG_DATA
199 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
200 {
201 	u8 *buf = (u8 *) packet;
202 	int j;
203 
204 	dprintk("RPC:       %s\n", msg);
205 	for (j = 0; j < count && j < 128; j += 4) {
206 		if (!(j & 31)) {
207 			if (j)
208 				dprintk("\n");
209 			dprintk("0x%04x ", j);
210 		}
211 		dprintk("%02x%02x%02x%02x ",
212 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
213 	}
214 	dprintk("\n");
215 }
216 #else
217 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
218 {
219 	/* NOP */
220 }
221 #endif
222 
223 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
224 {
225 	return (struct rpc_xprt *) sk->sk_user_data;
226 }
227 
228 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
229 {
230 	return (struct sockaddr *) &xprt->addr;
231 }
232 
233 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr_un *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_in *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in6 *) &xprt->addr;
246 }
247 
248 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
249 {
250 	struct sockaddr *sap = xs_addr(xprt);
251 	struct sockaddr_in6 *sin6;
252 	struct sockaddr_in *sin;
253 	struct sockaddr_un *sun;
254 	char buf[128];
255 
256 	switch (sap->sa_family) {
257 	case AF_LOCAL:
258 		sun = xs_addr_un(xprt);
259 		strlcpy(buf, sun->sun_path, sizeof(buf));
260 		xprt->address_strings[RPC_DISPLAY_ADDR] =
261 						kstrdup(buf, GFP_KERNEL);
262 		break;
263 	case AF_INET:
264 		(void)rpc_ntop(sap, buf, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		sin = xs_addr_in(xprt);
268 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
269 		break;
270 	case AF_INET6:
271 		(void)rpc_ntop(sap, buf, sizeof(buf));
272 		xprt->address_strings[RPC_DISPLAY_ADDR] =
273 						kstrdup(buf, GFP_KERNEL);
274 		sin6 = xs_addr_in6(xprt);
275 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
276 		break;
277 	default:
278 		BUG();
279 	}
280 
281 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
282 }
283 
284 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
285 {
286 	struct sockaddr *sap = xs_addr(xprt);
287 	char buf[128];
288 
289 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
290 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
291 
292 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
293 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
294 }
295 
296 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
297 				     const char *protocol,
298 				     const char *netid)
299 {
300 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
301 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
302 	xs_format_common_peer_addresses(xprt);
303 	xs_format_common_peer_ports(xprt);
304 }
305 
306 static void xs_update_peer_port(struct rpc_xprt *xprt)
307 {
308 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
309 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
310 
311 	xs_format_common_peer_ports(xprt);
312 }
313 
314 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
315 {
316 	unsigned int i;
317 
318 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
319 		switch (i) {
320 		case RPC_DISPLAY_PROTO:
321 		case RPC_DISPLAY_NETID:
322 			continue;
323 		default:
324 			kfree(xprt->address_strings[i]);
325 		}
326 }
327 
328 static size_t
329 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
330 {
331 	size_t i,n;
332 
333 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
334 		return want;
335 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
336 	for (i = 0; i < n; i++) {
337 		if (buf->pages[i])
338 			continue;
339 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
340 		if (!buf->pages[i]) {
341 			i *= PAGE_SIZE;
342 			return i > buf->page_base ? i - buf->page_base : 0;
343 		}
344 	}
345 	return want;
346 }
347 
348 static ssize_t
349 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
350 {
351 	ssize_t ret;
352 	if (seek != 0)
353 		iov_iter_advance(&msg->msg_iter, seek);
354 	ret = sock_recvmsg(sock, msg, flags);
355 	return ret > 0 ? ret + seek : ret;
356 }
357 
358 static ssize_t
359 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
360 		struct kvec *kvec, size_t count, size_t seek)
361 {
362 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
363 	return xs_sock_recvmsg(sock, msg, flags, seek);
364 }
365 
366 static ssize_t
367 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
368 		struct bio_vec *bvec, unsigned long nr, size_t count,
369 		size_t seek)
370 {
371 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
372 	return xs_sock_recvmsg(sock, msg, flags, seek);
373 }
374 
375 static ssize_t
376 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
377 		size_t count)
378 {
379 	struct kvec kvec = { 0 };
380 	return xs_read_kvec(sock, msg, flags | MSG_TRUNC, &kvec, count, 0);
381 }
382 
383 static ssize_t
384 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
385 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
386 {
387 	size_t want, seek_init = seek, offset = 0;
388 	ssize_t ret;
389 
390 	if (seek < buf->head[0].iov_len) {
391 		want = min_t(size_t, count, buf->head[0].iov_len);
392 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
393 		if (ret <= 0)
394 			goto sock_err;
395 		offset += ret;
396 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
397 			goto out;
398 		if (ret != want)
399 			goto out;
400 		seek = 0;
401 	} else {
402 		seek -= buf->head[0].iov_len;
403 		offset += buf->head[0].iov_len;
404 	}
405 
406 	want = xs_alloc_sparse_pages(buf,
407 			min_t(size_t, count - offset, buf->page_len),
408 			GFP_NOWAIT);
409 	if (seek < want) {
410 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
411 				xdr_buf_pagecount(buf),
412 				want + buf->page_base,
413 				seek + buf->page_base);
414 		if (ret <= 0)
415 			goto sock_err;
416 		offset += ret - buf->page_base;
417 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
418 			goto out;
419 		if (ret != want)
420 			goto out;
421 		seek = 0;
422 	} else {
423 		seek -= want;
424 		offset += want;
425 	}
426 
427 	if (seek < buf->tail[0].iov_len) {
428 		want = min_t(size_t, count - offset, buf->tail[0].iov_len);
429 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
430 		if (ret <= 0)
431 			goto sock_err;
432 		offset += ret;
433 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
434 			goto out;
435 		if (ret != want)
436 			goto out;
437 	} else
438 		offset += buf->tail[0].iov_len;
439 	ret = -EMSGSIZE;
440 out:
441 	*read = offset - seek_init;
442 	return ret;
443 sock_err:
444 	offset += seek;
445 	goto out;
446 }
447 
448 static void
449 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
450 {
451 	if (!transport->recv.copied) {
452 		if (buf->head[0].iov_len >= transport->recv.offset)
453 			memcpy(buf->head[0].iov_base,
454 					&transport->recv.xid,
455 					transport->recv.offset);
456 		transport->recv.copied = transport->recv.offset;
457 	}
458 }
459 
460 static bool
461 xs_read_stream_request_done(struct sock_xprt *transport)
462 {
463 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
464 }
465 
466 static ssize_t
467 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
468 		int flags, struct rpc_rqst *req)
469 {
470 	struct xdr_buf *buf = &req->rq_private_buf;
471 	size_t want, read;
472 	ssize_t ret;
473 
474 	xs_read_header(transport, buf);
475 
476 	want = transport->recv.len - transport->recv.offset;
477 	ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
478 			transport->recv.copied + want, transport->recv.copied,
479 			&read);
480 	transport->recv.offset += read;
481 	transport->recv.copied += read;
482 	if (transport->recv.offset == transport->recv.len) {
483 		if (xs_read_stream_request_done(transport))
484 			msg->msg_flags |= MSG_EOR;
485 		return read;
486 	}
487 
488 	switch (ret) {
489 	default:
490 		break;
491 	case -EFAULT:
492 	case -EMSGSIZE:
493 		msg->msg_flags |= MSG_TRUNC;
494 		return read;
495 	case 0:
496 		return -ESHUTDOWN;
497 	}
498 	return ret < 0 ? ret : read;
499 }
500 
501 static size_t
502 xs_read_stream_headersize(bool isfrag)
503 {
504 	if (isfrag)
505 		return sizeof(__be32);
506 	return 3 * sizeof(__be32);
507 }
508 
509 static ssize_t
510 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
511 		int flags, size_t want, size_t seek)
512 {
513 	struct kvec kvec = {
514 		.iov_base = &transport->recv.fraghdr,
515 		.iov_len = want,
516 	};
517 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
518 }
519 
520 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
521 static ssize_t
522 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
523 {
524 	struct rpc_xprt *xprt = &transport->xprt;
525 	struct rpc_rqst *req;
526 	ssize_t ret;
527 
528 	/* Look up and lock the request corresponding to the given XID */
529 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
530 	if (!req) {
531 		printk(KERN_WARNING "Callback slot table overflowed\n");
532 		return -ESHUTDOWN;
533 	}
534 
535 	ret = xs_read_stream_request(transport, msg, flags, req);
536 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
537 		xprt_complete_bc_request(req, transport->recv.copied);
538 
539 	return ret;
540 }
541 #else /* CONFIG_SUNRPC_BACKCHANNEL */
542 static ssize_t
543 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
544 {
545 	return -ESHUTDOWN;
546 }
547 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
548 
549 static ssize_t
550 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
551 {
552 	struct rpc_xprt *xprt = &transport->xprt;
553 	struct rpc_rqst *req;
554 	ssize_t ret = 0;
555 
556 	/* Look up and lock the request corresponding to the given XID */
557 	spin_lock(&xprt->queue_lock);
558 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
559 	if (!req) {
560 		msg->msg_flags |= MSG_TRUNC;
561 		goto out;
562 	}
563 	xprt_pin_rqst(req);
564 	spin_unlock(&xprt->queue_lock);
565 
566 	ret = xs_read_stream_request(transport, msg, flags, req);
567 
568 	spin_lock(&xprt->queue_lock);
569 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
570 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
571 	xprt_unpin_rqst(req);
572 out:
573 	spin_unlock(&xprt->queue_lock);
574 	return ret;
575 }
576 
577 static ssize_t
578 xs_read_stream(struct sock_xprt *transport, int flags)
579 {
580 	struct msghdr msg = { 0 };
581 	size_t want, read = 0;
582 	ssize_t ret = 0;
583 
584 	if (transport->recv.len == 0) {
585 		want = xs_read_stream_headersize(transport->recv.copied != 0);
586 		ret = xs_read_stream_header(transport, &msg, flags, want,
587 				transport->recv.offset);
588 		if (ret <= 0)
589 			goto out_err;
590 		transport->recv.offset = ret;
591 		if (transport->recv.offset != want)
592 			return transport->recv.offset;
593 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
594 			RPC_FRAGMENT_SIZE_MASK;
595 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
596 		read = ret;
597 	}
598 
599 	switch (be32_to_cpu(transport->recv.calldir)) {
600 	default:
601 		msg.msg_flags |= MSG_TRUNC;
602 		break;
603 	case RPC_CALL:
604 		ret = xs_read_stream_call(transport, &msg, flags);
605 		break;
606 	case RPC_REPLY:
607 		ret = xs_read_stream_reply(transport, &msg, flags);
608 	}
609 	if (msg.msg_flags & MSG_TRUNC) {
610 		transport->recv.calldir = cpu_to_be32(-1);
611 		transport->recv.copied = -1;
612 	}
613 	if (ret < 0)
614 		goto out_err;
615 	read += ret;
616 	if (transport->recv.offset < transport->recv.len) {
617 		if (!(msg.msg_flags & MSG_TRUNC))
618 			return read;
619 		ret = xs_read_discard(transport->sock, &msg, flags,
620 				transport->recv.len - transport->recv.offset);
621 		if (ret <= 0)
622 			goto out_err;
623 		transport->recv.offset += ret;
624 		read += ret;
625 		if (transport->recv.offset != transport->recv.len)
626 			return read;
627 	}
628 	if (xs_read_stream_request_done(transport)) {
629 		trace_xs_stream_read_request(transport);
630 		transport->recv.copied = 0;
631 	}
632 	transport->recv.offset = 0;
633 	transport->recv.len = 0;
634 	return read;
635 out_err:
636 	switch (ret) {
637 	case 0:
638 	case -ESHUTDOWN:
639 		xprt_force_disconnect(&transport->xprt);
640 		return -ESHUTDOWN;
641 	}
642 	return ret;
643 }
644 
645 static void xs_stream_data_receive(struct sock_xprt *transport)
646 {
647 	size_t read = 0;
648 	ssize_t ret = 0;
649 
650 	mutex_lock(&transport->recv_mutex);
651 	if (transport->sock == NULL)
652 		goto out;
653 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
654 	for (;;) {
655 		ret = xs_read_stream(transport, MSG_DONTWAIT);
656 		if (ret < 0)
657 			break;
658 		read += ret;
659 		cond_resched();
660 	}
661 out:
662 	mutex_unlock(&transport->recv_mutex);
663 	trace_xs_stream_read_data(&transport->xprt, ret, read);
664 }
665 
666 static void xs_stream_data_receive_workfn(struct work_struct *work)
667 {
668 	struct sock_xprt *transport =
669 		container_of(work, struct sock_xprt, recv_worker);
670 	xs_stream_data_receive(transport);
671 }
672 
673 static void
674 xs_stream_reset_connect(struct sock_xprt *transport)
675 {
676 	transport->recv.offset = 0;
677 	transport->recv.len = 0;
678 	transport->recv.copied = 0;
679 	transport->xmit.offset = 0;
680 	transport->xprt.stat.connect_count++;
681 	transport->xprt.stat.connect_start = jiffies;
682 }
683 
684 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
685 
686 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
687 {
688 	struct msghdr msg = {
689 		.msg_name	= addr,
690 		.msg_namelen	= addrlen,
691 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
692 	};
693 	struct kvec iov = {
694 		.iov_base	= vec->iov_base + base,
695 		.iov_len	= vec->iov_len - base,
696 	};
697 
698 	if (iov.iov_len != 0)
699 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
700 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
701 }
702 
703 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
704 {
705 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
706 			int offset, size_t size, int flags);
707 	struct page **ppage;
708 	unsigned int remainder;
709 	int err;
710 
711 	remainder = xdr->page_len - base;
712 	base += xdr->page_base;
713 	ppage = xdr->pages + (base >> PAGE_SHIFT);
714 	base &= ~PAGE_MASK;
715 	do_sendpage = sock->ops->sendpage;
716 	if (!zerocopy)
717 		do_sendpage = sock_no_sendpage;
718 	for(;;) {
719 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
720 		int flags = XS_SENDMSG_FLAGS;
721 
722 		remainder -= len;
723 		if (more)
724 			flags |= MSG_MORE;
725 		if (remainder != 0)
726 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
727 		err = do_sendpage(sock, *ppage, base, len, flags);
728 		if (remainder == 0 || err != len)
729 			break;
730 		*sent_p += err;
731 		ppage++;
732 		base = 0;
733 	}
734 	if (err > 0) {
735 		*sent_p += err;
736 		err = 0;
737 	}
738 	return err;
739 }
740 
741 /**
742  * xs_sendpages - write pages directly to a socket
743  * @sock: socket to send on
744  * @addr: UDP only -- address of destination
745  * @addrlen: UDP only -- length of destination address
746  * @xdr: buffer containing this request
747  * @base: starting position in the buffer
748  * @zerocopy: true if it is safe to use sendpage()
749  * @sent_p: return the total number of bytes successfully queued for sending
750  *
751  */
752 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
753 {
754 	unsigned int remainder = xdr->len - base;
755 	int err = 0;
756 	int sent = 0;
757 
758 	if (unlikely(!sock))
759 		return -ENOTSOCK;
760 
761 	if (base != 0) {
762 		addr = NULL;
763 		addrlen = 0;
764 	}
765 
766 	if (base < xdr->head[0].iov_len || addr != NULL) {
767 		unsigned int len = xdr->head[0].iov_len - base;
768 		remainder -= len;
769 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
770 		if (remainder == 0 || err != len)
771 			goto out;
772 		*sent_p += err;
773 		base = 0;
774 	} else
775 		base -= xdr->head[0].iov_len;
776 
777 	if (base < xdr->page_len) {
778 		unsigned int len = xdr->page_len - base;
779 		remainder -= len;
780 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
781 		*sent_p += sent;
782 		if (remainder == 0 || sent != len)
783 			goto out;
784 		base = 0;
785 	} else
786 		base -= xdr->page_len;
787 
788 	if (base >= xdr->tail[0].iov_len)
789 		return 0;
790 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
791 out:
792 	if (err > 0) {
793 		*sent_p += err;
794 		err = 0;
795 	}
796 	return err;
797 }
798 
799 /**
800  * xs_nospace - handle transmit was incomplete
801  * @req: pointer to RPC request
802  *
803  */
804 static int xs_nospace(struct rpc_rqst *req)
805 {
806 	struct rpc_xprt *xprt = req->rq_xprt;
807 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
808 	struct sock *sk = transport->inet;
809 	int ret = -EAGAIN;
810 
811 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
812 			req->rq_task->tk_pid,
813 			req->rq_slen - transport->xmit.offset,
814 			req->rq_slen);
815 
816 	/* Protect against races with write_space */
817 	spin_lock_bh(&xprt->transport_lock);
818 
819 	/* Don't race with disconnect */
820 	if (xprt_connected(xprt)) {
821 		/* wait for more buffer space */
822 		sk->sk_write_pending++;
823 		xprt_wait_for_buffer_space(xprt);
824 	} else
825 		ret = -ENOTCONN;
826 
827 	spin_unlock_bh(&xprt->transport_lock);
828 
829 	/* Race breaker in case memory is freed before above code is called */
830 	if (ret == -EAGAIN) {
831 		struct socket_wq *wq;
832 
833 		rcu_read_lock();
834 		wq = rcu_dereference(sk->sk_wq);
835 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
836 		rcu_read_unlock();
837 
838 		sk->sk_write_space(sk);
839 	}
840 	return ret;
841 }
842 
843 static void
844 xs_stream_prepare_request(struct rpc_rqst *req)
845 {
846 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_NOIO);
847 }
848 
849 /*
850  * Determine if the previous message in the stream was aborted before it
851  * could complete transmission.
852  */
853 static bool
854 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
855 {
856 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
857 }
858 
859 /*
860  * Construct a stream transport record marker in @buf.
861  */
862 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
863 {
864 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
865 	rpc_fraghdr *base = buf->head[0].iov_base;
866 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
867 }
868 
869 /**
870  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
871  * @req: pointer to RPC request
872  *
873  * Return values:
874  *        0:	The request has been sent
875  *   EAGAIN:	The socket was blocked, please call again later to
876  *		complete the request
877  * ENOTCONN:	Caller needs to invoke connect logic then call again
878  *    other:	Some other error occured, the request was not sent
879  */
880 static int xs_local_send_request(struct rpc_rqst *req)
881 {
882 	struct rpc_xprt *xprt = req->rq_xprt;
883 	struct sock_xprt *transport =
884 				container_of(xprt, struct sock_xprt, xprt);
885 	struct xdr_buf *xdr = &req->rq_snd_buf;
886 	int status;
887 	int sent = 0;
888 
889 	/* Close the stream if the previous transmission was incomplete */
890 	if (xs_send_request_was_aborted(transport, req)) {
891 		xs_close(xprt);
892 		return -ENOTCONN;
893 	}
894 
895 	xs_encode_stream_record_marker(&req->rq_snd_buf);
896 
897 	xs_pktdump("packet data:",
898 			req->rq_svec->iov_base, req->rq_svec->iov_len);
899 
900 	req->rq_xtime = ktime_get();
901 	status = xs_sendpages(transport->sock, NULL, 0, xdr,
902 			      transport->xmit.offset,
903 			      true, &sent);
904 	dprintk("RPC:       %s(%u) = %d\n",
905 			__func__, xdr->len - transport->xmit.offset, status);
906 
907 	if (status == -EAGAIN && sock_writeable(transport->inet))
908 		status = -ENOBUFS;
909 
910 	if (likely(sent > 0) || status == 0) {
911 		transport->xmit.offset += sent;
912 		req->rq_bytes_sent = transport->xmit.offset;
913 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
914 			req->rq_xmit_bytes_sent += transport->xmit.offset;
915 			req->rq_bytes_sent = 0;
916 			transport->xmit.offset = 0;
917 			return 0;
918 		}
919 		status = -EAGAIN;
920 	}
921 
922 	switch (status) {
923 	case -ENOBUFS:
924 		break;
925 	case -EAGAIN:
926 		status = xs_nospace(req);
927 		break;
928 	default:
929 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
930 			-status);
931 		/* fall through */
932 	case -EPIPE:
933 		xs_close(xprt);
934 		status = -ENOTCONN;
935 	}
936 
937 	return status;
938 }
939 
940 /**
941  * xs_udp_send_request - write an RPC request to a UDP socket
942  * @req: pointer to RPC request
943  *
944  * Return values:
945  *        0:	The request has been sent
946  *   EAGAIN:	The socket was blocked, please call again later to
947  *		complete the request
948  * ENOTCONN:	Caller needs to invoke connect logic then call again
949  *    other:	Some other error occurred, the request was not sent
950  */
951 static int xs_udp_send_request(struct rpc_rqst *req)
952 {
953 	struct rpc_xprt *xprt = req->rq_xprt;
954 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
955 	struct xdr_buf *xdr = &req->rq_snd_buf;
956 	int sent = 0;
957 	int status;
958 
959 	xs_pktdump("packet data:",
960 				req->rq_svec->iov_base,
961 				req->rq_svec->iov_len);
962 
963 	if (!xprt_bound(xprt))
964 		return -ENOTCONN;
965 
966 	if (!xprt_request_get_cong(xprt, req))
967 		return -EBADSLT;
968 
969 	req->rq_xtime = ktime_get();
970 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
971 			      xdr, 0, true, &sent);
972 
973 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
974 			xdr->len, status);
975 
976 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
977 	if (status == -EPERM)
978 		goto process_status;
979 
980 	if (status == -EAGAIN && sock_writeable(transport->inet))
981 		status = -ENOBUFS;
982 
983 	if (sent > 0 || status == 0) {
984 		req->rq_xmit_bytes_sent += sent;
985 		if (sent >= req->rq_slen)
986 			return 0;
987 		/* Still some bytes left; set up for a retry later. */
988 		status = -EAGAIN;
989 	}
990 
991 process_status:
992 	switch (status) {
993 	case -ENOTSOCK:
994 		status = -ENOTCONN;
995 		/* Should we call xs_close() here? */
996 		break;
997 	case -EAGAIN:
998 		status = xs_nospace(req);
999 		break;
1000 	case -ENETUNREACH:
1001 	case -ENOBUFS:
1002 	case -EPIPE:
1003 	case -ECONNREFUSED:
1004 	case -EPERM:
1005 		/* When the server has died, an ICMP port unreachable message
1006 		 * prompts ECONNREFUSED. */
1007 		break;
1008 	default:
1009 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1010 			-status);
1011 	}
1012 
1013 	return status;
1014 }
1015 
1016 /**
1017  * xs_tcp_send_request - write an RPC request to a TCP socket
1018  * @req: pointer to RPC request
1019  *
1020  * Return values:
1021  *        0:	The request has been sent
1022  *   EAGAIN:	The socket was blocked, please call again later to
1023  *		complete the request
1024  * ENOTCONN:	Caller needs to invoke connect logic then call again
1025  *    other:	Some other error occurred, the request was not sent
1026  *
1027  * XXX: In the case of soft timeouts, should we eventually give up
1028  *	if sendmsg is not able to make progress?
1029  */
1030 static int xs_tcp_send_request(struct rpc_rqst *req)
1031 {
1032 	struct rpc_xprt *xprt = req->rq_xprt;
1033 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1034 	struct xdr_buf *xdr = &req->rq_snd_buf;
1035 	bool zerocopy = true;
1036 	bool vm_wait = false;
1037 	int status;
1038 	int sent;
1039 
1040 	/* Close the stream if the previous transmission was incomplete */
1041 	if (xs_send_request_was_aborted(transport, req)) {
1042 		if (transport->sock != NULL)
1043 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1044 		return -ENOTCONN;
1045 	}
1046 
1047 	xs_encode_stream_record_marker(&req->rq_snd_buf);
1048 
1049 	xs_pktdump("packet data:",
1050 				req->rq_svec->iov_base,
1051 				req->rq_svec->iov_len);
1052 	/* Don't use zero copy if this is a resend. If the RPC call
1053 	 * completes while the socket holds a reference to the pages,
1054 	 * then we may end up resending corrupted data.
1055 	 */
1056 	if (req->rq_task->tk_flags & RPC_TASK_SENT)
1057 		zerocopy = false;
1058 
1059 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1060 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1061 
1062 	/* Continue transmitting the packet/record. We must be careful
1063 	 * to cope with writespace callbacks arriving _after_ we have
1064 	 * called sendmsg(). */
1065 	req->rq_xtime = ktime_get();
1066 	while (1) {
1067 		sent = 0;
1068 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
1069 				      transport->xmit.offset,
1070 				      zerocopy, &sent);
1071 
1072 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1073 				xdr->len - transport->xmit.offset, status);
1074 
1075 		/* If we've sent the entire packet, immediately
1076 		 * reset the count of bytes sent. */
1077 		transport->xmit.offset += sent;
1078 		req->rq_bytes_sent = transport->xmit.offset;
1079 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
1080 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1081 			req->rq_bytes_sent = 0;
1082 			transport->xmit.offset = 0;
1083 			return 0;
1084 		}
1085 
1086 		WARN_ON_ONCE(sent == 0 && status == 0);
1087 
1088 		if (status == -EAGAIN ) {
1089 			/*
1090 			 * Return EAGAIN if we're sure we're hitting the
1091 			 * socket send buffer limits.
1092 			 */
1093 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1094 				break;
1095 			/*
1096 			 * Did we hit a memory allocation failure?
1097 			 */
1098 			if (sent == 0) {
1099 				status = -ENOBUFS;
1100 				if (vm_wait)
1101 					break;
1102 				/* Retry, knowing now that we're below the
1103 				 * socket send buffer limit
1104 				 */
1105 				vm_wait = true;
1106 			}
1107 			continue;
1108 		}
1109 		if (status < 0)
1110 			break;
1111 		vm_wait = false;
1112 	}
1113 
1114 	switch (status) {
1115 	case -ENOTSOCK:
1116 		status = -ENOTCONN;
1117 		/* Should we call xs_close() here? */
1118 		break;
1119 	case -EAGAIN:
1120 		status = xs_nospace(req);
1121 		break;
1122 	case -ECONNRESET:
1123 	case -ECONNREFUSED:
1124 	case -ENOTCONN:
1125 	case -EADDRINUSE:
1126 	case -ENOBUFS:
1127 	case -EPIPE:
1128 		break;
1129 	default:
1130 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1131 			-status);
1132 	}
1133 
1134 	return status;
1135 }
1136 
1137 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1138 {
1139 	transport->old_data_ready = sk->sk_data_ready;
1140 	transport->old_state_change = sk->sk_state_change;
1141 	transport->old_write_space = sk->sk_write_space;
1142 	transport->old_error_report = sk->sk_error_report;
1143 }
1144 
1145 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1146 {
1147 	sk->sk_data_ready = transport->old_data_ready;
1148 	sk->sk_state_change = transport->old_state_change;
1149 	sk->sk_write_space = transport->old_write_space;
1150 	sk->sk_error_report = transport->old_error_report;
1151 }
1152 
1153 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1154 {
1155 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1156 
1157 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1158 }
1159 
1160 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1161 {
1162 	smp_mb__before_atomic();
1163 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1164 	clear_bit(XPRT_CLOSING, &xprt->state);
1165 	xs_sock_reset_state_flags(xprt);
1166 	smp_mb__after_atomic();
1167 }
1168 
1169 /**
1170  * xs_error_report - callback to handle TCP socket state errors
1171  * @sk: socket
1172  *
1173  * Note: we don't call sock_error() since there may be a rpc_task
1174  * using the socket, and so we don't want to clear sk->sk_err.
1175  */
1176 static void xs_error_report(struct sock *sk)
1177 {
1178 	struct rpc_xprt *xprt;
1179 	int err;
1180 
1181 	read_lock_bh(&sk->sk_callback_lock);
1182 	if (!(xprt = xprt_from_sock(sk)))
1183 		goto out;
1184 
1185 	err = -sk->sk_err;
1186 	if (err == 0)
1187 		goto out;
1188 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1189 			xprt, -err);
1190 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
1191 	xprt_wake_pending_tasks(xprt, err);
1192  out:
1193 	read_unlock_bh(&sk->sk_callback_lock);
1194 }
1195 
1196 static void xs_reset_transport(struct sock_xprt *transport)
1197 {
1198 	struct socket *sock = transport->sock;
1199 	struct sock *sk = transport->inet;
1200 	struct rpc_xprt *xprt = &transport->xprt;
1201 
1202 	if (sk == NULL)
1203 		return;
1204 
1205 	if (atomic_read(&transport->xprt.swapper))
1206 		sk_clear_memalloc(sk);
1207 
1208 	kernel_sock_shutdown(sock, SHUT_RDWR);
1209 
1210 	mutex_lock(&transport->recv_mutex);
1211 	write_lock_bh(&sk->sk_callback_lock);
1212 	transport->inet = NULL;
1213 	transport->sock = NULL;
1214 
1215 	sk->sk_user_data = NULL;
1216 
1217 	xs_restore_old_callbacks(transport, sk);
1218 	xprt_clear_connected(xprt);
1219 	write_unlock_bh(&sk->sk_callback_lock);
1220 	xs_sock_reset_connection_flags(xprt);
1221 	mutex_unlock(&transport->recv_mutex);
1222 
1223 	trace_rpc_socket_close(xprt, sock);
1224 	sock_release(sock);
1225 }
1226 
1227 /**
1228  * xs_close - close a socket
1229  * @xprt: transport
1230  *
1231  * This is used when all requests are complete; ie, no DRC state remains
1232  * on the server we want to save.
1233  *
1234  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1235  * xs_reset_transport() zeroing the socket from underneath a writer.
1236  */
1237 static void xs_close(struct rpc_xprt *xprt)
1238 {
1239 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1240 
1241 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1242 
1243 	xs_reset_transport(transport);
1244 	xprt->reestablish_timeout = 0;
1245 
1246 	xprt_disconnect_done(xprt);
1247 }
1248 
1249 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1250 {
1251 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1252 		xprt);
1253 	xprt_disconnect_done(xprt);
1254 }
1255 
1256 static void xs_xprt_free(struct rpc_xprt *xprt)
1257 {
1258 	xs_free_peer_addresses(xprt);
1259 	xprt_free(xprt);
1260 }
1261 
1262 /**
1263  * xs_destroy - prepare to shutdown a transport
1264  * @xprt: doomed transport
1265  *
1266  */
1267 static void xs_destroy(struct rpc_xprt *xprt)
1268 {
1269 	struct sock_xprt *transport = container_of(xprt,
1270 			struct sock_xprt, xprt);
1271 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1272 
1273 	cancel_delayed_work_sync(&transport->connect_worker);
1274 	xs_close(xprt);
1275 	cancel_work_sync(&transport->recv_worker);
1276 	xs_xprt_free(xprt);
1277 	module_put(THIS_MODULE);
1278 }
1279 
1280 /**
1281  * xs_udp_data_read_skb - receive callback for UDP sockets
1282  * @xprt: transport
1283  * @sk: socket
1284  * @skb: skbuff
1285  *
1286  */
1287 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1288 		struct sock *sk,
1289 		struct sk_buff *skb)
1290 {
1291 	struct rpc_task *task;
1292 	struct rpc_rqst *rovr;
1293 	int repsize, copied;
1294 	u32 _xid;
1295 	__be32 *xp;
1296 
1297 	repsize = skb->len;
1298 	if (repsize < 4) {
1299 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1300 		return;
1301 	}
1302 
1303 	/* Copy the XID from the skb... */
1304 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1305 	if (xp == NULL)
1306 		return;
1307 
1308 	/* Look up and lock the request corresponding to the given XID */
1309 	spin_lock(&xprt->queue_lock);
1310 	rovr = xprt_lookup_rqst(xprt, *xp);
1311 	if (!rovr)
1312 		goto out_unlock;
1313 	xprt_pin_rqst(rovr);
1314 	xprt_update_rtt(rovr->rq_task);
1315 	spin_unlock(&xprt->queue_lock);
1316 	task = rovr->rq_task;
1317 
1318 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1319 		copied = repsize;
1320 
1321 	/* Suck it into the iovec, verify checksum if not done by hw. */
1322 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1323 		spin_lock(&xprt->queue_lock);
1324 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1325 		goto out_unpin;
1326 	}
1327 
1328 
1329 	spin_lock_bh(&xprt->transport_lock);
1330 	xprt_adjust_cwnd(xprt, task, copied);
1331 	spin_unlock_bh(&xprt->transport_lock);
1332 	spin_lock(&xprt->queue_lock);
1333 	xprt_complete_rqst(task, copied);
1334 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1335 out_unpin:
1336 	xprt_unpin_rqst(rovr);
1337  out_unlock:
1338 	spin_unlock(&xprt->queue_lock);
1339 }
1340 
1341 static void xs_udp_data_receive(struct sock_xprt *transport)
1342 {
1343 	struct sk_buff *skb;
1344 	struct sock *sk;
1345 	int err;
1346 
1347 	mutex_lock(&transport->recv_mutex);
1348 	sk = transport->inet;
1349 	if (sk == NULL)
1350 		goto out;
1351 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1352 	for (;;) {
1353 		skb = skb_recv_udp(sk, 0, 1, &err);
1354 		if (skb == NULL)
1355 			break;
1356 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1357 		consume_skb(skb);
1358 		cond_resched();
1359 	}
1360 out:
1361 	mutex_unlock(&transport->recv_mutex);
1362 }
1363 
1364 static void xs_udp_data_receive_workfn(struct work_struct *work)
1365 {
1366 	struct sock_xprt *transport =
1367 		container_of(work, struct sock_xprt, recv_worker);
1368 	xs_udp_data_receive(transport);
1369 }
1370 
1371 /**
1372  * xs_data_ready - "data ready" callback for UDP sockets
1373  * @sk: socket with data to read
1374  *
1375  */
1376 static void xs_data_ready(struct sock *sk)
1377 {
1378 	struct rpc_xprt *xprt;
1379 
1380 	read_lock_bh(&sk->sk_callback_lock);
1381 	dprintk("RPC:       xs_data_ready...\n");
1382 	xprt = xprt_from_sock(sk);
1383 	if (xprt != NULL) {
1384 		struct sock_xprt *transport = container_of(xprt,
1385 				struct sock_xprt, xprt);
1386 		transport->old_data_ready(sk);
1387 		/* Any data means we had a useful conversation, so
1388 		 * then we don't need to delay the next reconnect
1389 		 */
1390 		if (xprt->reestablish_timeout)
1391 			xprt->reestablish_timeout = 0;
1392 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1393 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1394 	}
1395 	read_unlock_bh(&sk->sk_callback_lock);
1396 }
1397 
1398 /*
1399  * Helper function to force a TCP close if the server is sending
1400  * junk and/or it has put us in CLOSE_WAIT
1401  */
1402 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1403 {
1404 	xprt_force_disconnect(xprt);
1405 }
1406 
1407 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1408 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1409 {
1410 	int ret;
1411 
1412 	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1413 			      SVC_SOCK_ANONYMOUS);
1414 	if (ret < 0)
1415 		return ret;
1416 	return 0;
1417 }
1418 
1419 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1420 {
1421 	return PAGE_SIZE;
1422 }
1423 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1424 
1425 /**
1426  * xs_tcp_state_change - callback to handle TCP socket state changes
1427  * @sk: socket whose state has changed
1428  *
1429  */
1430 static void xs_tcp_state_change(struct sock *sk)
1431 {
1432 	struct rpc_xprt *xprt;
1433 	struct sock_xprt *transport;
1434 
1435 	read_lock_bh(&sk->sk_callback_lock);
1436 	if (!(xprt = xprt_from_sock(sk)))
1437 		goto out;
1438 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1439 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1440 			sk->sk_state, xprt_connected(xprt),
1441 			sock_flag(sk, SOCK_DEAD),
1442 			sock_flag(sk, SOCK_ZAPPED),
1443 			sk->sk_shutdown);
1444 
1445 	transport = container_of(xprt, struct sock_xprt, xprt);
1446 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1447 	switch (sk->sk_state) {
1448 	case TCP_ESTABLISHED:
1449 		spin_lock(&xprt->transport_lock);
1450 		if (!xprt_test_and_set_connected(xprt)) {
1451 			xprt->connect_cookie++;
1452 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1453 			xprt_clear_connecting(xprt);
1454 
1455 			xprt->stat.connect_count++;
1456 			xprt->stat.connect_time += (long)jiffies -
1457 						   xprt->stat.connect_start;
1458 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1459 		}
1460 		spin_unlock(&xprt->transport_lock);
1461 		break;
1462 	case TCP_FIN_WAIT1:
1463 		/* The client initiated a shutdown of the socket */
1464 		xprt->connect_cookie++;
1465 		xprt->reestablish_timeout = 0;
1466 		set_bit(XPRT_CLOSING, &xprt->state);
1467 		smp_mb__before_atomic();
1468 		clear_bit(XPRT_CONNECTED, &xprt->state);
1469 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1470 		smp_mb__after_atomic();
1471 		break;
1472 	case TCP_CLOSE_WAIT:
1473 		/* The server initiated a shutdown of the socket */
1474 		xprt->connect_cookie++;
1475 		clear_bit(XPRT_CONNECTED, &xprt->state);
1476 		xs_tcp_force_close(xprt);
1477 		/* fall through */
1478 	case TCP_CLOSING:
1479 		/*
1480 		 * If the server closed down the connection, make sure that
1481 		 * we back off before reconnecting
1482 		 */
1483 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1484 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1485 		break;
1486 	case TCP_LAST_ACK:
1487 		set_bit(XPRT_CLOSING, &xprt->state);
1488 		smp_mb__before_atomic();
1489 		clear_bit(XPRT_CONNECTED, &xprt->state);
1490 		smp_mb__after_atomic();
1491 		break;
1492 	case TCP_CLOSE:
1493 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1494 					&transport->sock_state))
1495 			xprt_clear_connecting(xprt);
1496 		clear_bit(XPRT_CLOSING, &xprt->state);
1497 		if (sk->sk_err)
1498 			xprt_wake_pending_tasks(xprt, -sk->sk_err);
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  * @task: task that timed out
1611  *
1612  * Adjust the congestion window after a retransmit timeout has occurred.
1613  */
1614 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1615 {
1616 	spin_lock_bh(&xprt->transport_lock);
1617 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1618 	spin_unlock_bh(&xprt->transport_lock);
1619 }
1620 
1621 static int xs_get_random_port(void)
1622 {
1623 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1624 	unsigned short range;
1625 	unsigned short rand;
1626 
1627 	if (max < min)
1628 		return -EADDRINUSE;
1629 	range = max - min + 1;
1630 	rand = (unsigned short) prandom_u32() % range;
1631 	return rand + min;
1632 }
1633 
1634 /**
1635  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1636  * @sock: socket
1637  *
1638  * Note that this function has to be called on all sockets that share the
1639  * same port, and it must be called before binding.
1640  */
1641 static void xs_sock_set_reuseport(struct socket *sock)
1642 {
1643 	int opt = 1;
1644 
1645 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1646 			(char *)&opt, sizeof(opt));
1647 }
1648 
1649 static unsigned short xs_sock_getport(struct socket *sock)
1650 {
1651 	struct sockaddr_storage buf;
1652 	unsigned short port = 0;
1653 
1654 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1655 		goto out;
1656 	switch (buf.ss_family) {
1657 	case AF_INET6:
1658 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1659 		break;
1660 	case AF_INET:
1661 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1662 	}
1663 out:
1664 	return port;
1665 }
1666 
1667 /**
1668  * xs_set_port - reset the port number in the remote endpoint address
1669  * @xprt: generic transport
1670  * @port: new port number
1671  *
1672  */
1673 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1674 {
1675 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1676 
1677 	rpc_set_port(xs_addr(xprt), port);
1678 	xs_update_peer_port(xprt);
1679 }
1680 
1681 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1682 {
1683 	if (transport->srcport == 0)
1684 		transport->srcport = xs_sock_getport(sock);
1685 }
1686 
1687 static int xs_get_srcport(struct sock_xprt *transport)
1688 {
1689 	int port = transport->srcport;
1690 
1691 	if (port == 0 && transport->xprt.resvport)
1692 		port = xs_get_random_port();
1693 	return port;
1694 }
1695 
1696 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1697 {
1698 	if (transport->srcport != 0)
1699 		transport->srcport = 0;
1700 	if (!transport->xprt.resvport)
1701 		return 0;
1702 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1703 		return xprt_max_resvport;
1704 	return --port;
1705 }
1706 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1707 {
1708 	struct sockaddr_storage myaddr;
1709 	int err, nloop = 0;
1710 	int port = xs_get_srcport(transport);
1711 	unsigned short last;
1712 
1713 	/*
1714 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1715 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1716 	 * port selection happen implicitly when the socket is used
1717 	 * (for example at connect time).
1718 	 *
1719 	 * This ensures that we can continue to establish TCP
1720 	 * connections even when all local ephemeral ports are already
1721 	 * a part of some TCP connection.  This makes no difference
1722 	 * for UDP sockets, but also doens't harm them.
1723 	 *
1724 	 * If we're asking for any reserved port (i.e. port == 0 &&
1725 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1726 	 * ensure that port is non-zero and we will bind as needed.
1727 	 */
1728 	if (port <= 0)
1729 		return port;
1730 
1731 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1732 	do {
1733 		rpc_set_port((struct sockaddr *)&myaddr, port);
1734 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1735 				transport->xprt.addrlen);
1736 		if (err == 0) {
1737 			transport->srcport = port;
1738 			break;
1739 		}
1740 		last = port;
1741 		port = xs_next_srcport(transport, port);
1742 		if (port > last)
1743 			nloop++;
1744 	} while (err == -EADDRINUSE && nloop != 2);
1745 
1746 	if (myaddr.ss_family == AF_INET)
1747 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1748 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1749 				port, err ? "failed" : "ok", err);
1750 	else
1751 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1752 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1753 				port, err ? "failed" : "ok", err);
1754 	return err;
1755 }
1756 
1757 /*
1758  * We don't support autobind on AF_LOCAL sockets
1759  */
1760 static void xs_local_rpcbind(struct rpc_task *task)
1761 {
1762 	xprt_set_bound(task->tk_xprt);
1763 }
1764 
1765 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1766 {
1767 }
1768 
1769 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1770 static struct lock_class_key xs_key[2];
1771 static struct lock_class_key xs_slock_key[2];
1772 
1773 static inline void xs_reclassify_socketu(struct socket *sock)
1774 {
1775 	struct sock *sk = sock->sk;
1776 
1777 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1778 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1779 }
1780 
1781 static inline void xs_reclassify_socket4(struct socket *sock)
1782 {
1783 	struct sock *sk = sock->sk;
1784 
1785 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1786 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1787 }
1788 
1789 static inline void xs_reclassify_socket6(struct socket *sock)
1790 {
1791 	struct sock *sk = sock->sk;
1792 
1793 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1794 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1795 }
1796 
1797 static inline void xs_reclassify_socket(int family, struct socket *sock)
1798 {
1799 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1800 		return;
1801 
1802 	switch (family) {
1803 	case AF_LOCAL:
1804 		xs_reclassify_socketu(sock);
1805 		break;
1806 	case AF_INET:
1807 		xs_reclassify_socket4(sock);
1808 		break;
1809 	case AF_INET6:
1810 		xs_reclassify_socket6(sock);
1811 		break;
1812 	}
1813 }
1814 #else
1815 static inline void xs_reclassify_socket(int family, struct socket *sock)
1816 {
1817 }
1818 #endif
1819 
1820 static void xs_dummy_setup_socket(struct work_struct *work)
1821 {
1822 }
1823 
1824 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1825 		struct sock_xprt *transport, int family, int type,
1826 		int protocol, bool reuseport)
1827 {
1828 	struct socket *sock;
1829 	int err;
1830 
1831 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1832 	if (err < 0) {
1833 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1834 				protocol, -err);
1835 		goto out;
1836 	}
1837 	xs_reclassify_socket(family, sock);
1838 
1839 	if (reuseport)
1840 		xs_sock_set_reuseport(sock);
1841 
1842 	err = xs_bind(transport, sock);
1843 	if (err) {
1844 		sock_release(sock);
1845 		goto out;
1846 	}
1847 
1848 	return sock;
1849 out:
1850 	return ERR_PTR(err);
1851 }
1852 
1853 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1854 				      struct socket *sock)
1855 {
1856 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1857 									xprt);
1858 
1859 	if (!transport->inet) {
1860 		struct sock *sk = sock->sk;
1861 
1862 		write_lock_bh(&sk->sk_callback_lock);
1863 
1864 		xs_save_old_callbacks(transport, sk);
1865 
1866 		sk->sk_user_data = xprt;
1867 		sk->sk_data_ready = xs_data_ready;
1868 		sk->sk_write_space = xs_udp_write_space;
1869 		sock_set_flag(sk, SOCK_FASYNC);
1870 		sk->sk_error_report = xs_error_report;
1871 		sk->sk_allocation = GFP_NOIO;
1872 
1873 		xprt_clear_connected(xprt);
1874 
1875 		/* Reset to new socket */
1876 		transport->sock = sock;
1877 		transport->inet = sk;
1878 
1879 		write_unlock_bh(&sk->sk_callback_lock);
1880 	}
1881 
1882 	xs_stream_reset_connect(transport);
1883 
1884 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1885 }
1886 
1887 /**
1888  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1889  * @transport: socket transport to connect
1890  */
1891 static int xs_local_setup_socket(struct sock_xprt *transport)
1892 {
1893 	struct rpc_xprt *xprt = &transport->xprt;
1894 	struct socket *sock;
1895 	int status = -EIO;
1896 
1897 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1898 					SOCK_STREAM, 0, &sock, 1);
1899 	if (status < 0) {
1900 		dprintk("RPC:       can't create AF_LOCAL "
1901 			"transport socket (%d).\n", -status);
1902 		goto out;
1903 	}
1904 	xs_reclassify_socket(AF_LOCAL, sock);
1905 
1906 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1907 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1908 
1909 	status = xs_local_finish_connecting(xprt, sock);
1910 	trace_rpc_socket_connect(xprt, sock, status);
1911 	switch (status) {
1912 	case 0:
1913 		dprintk("RPC:       xprt %p connected to %s\n",
1914 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1915 		xprt->stat.connect_count++;
1916 		xprt->stat.connect_time += (long)jiffies -
1917 					   xprt->stat.connect_start;
1918 		xprt_set_connected(xprt);
1919 	case -ENOBUFS:
1920 		break;
1921 	case -ENOENT:
1922 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1923 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1924 		break;
1925 	case -ECONNREFUSED:
1926 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1927 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1928 		break;
1929 	default:
1930 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1931 				__func__, -status,
1932 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1933 	}
1934 
1935 out:
1936 	xprt_clear_connecting(xprt);
1937 	xprt_wake_pending_tasks(xprt, status);
1938 	return status;
1939 }
1940 
1941 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1942 {
1943 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1944 	int ret;
1945 
1946 	 if (RPC_IS_ASYNC(task)) {
1947 		/*
1948 		 * We want the AF_LOCAL connect to be resolved in the
1949 		 * filesystem namespace of the process making the rpc
1950 		 * call.  Thus we connect synchronously.
1951 		 *
1952 		 * If we want to support asynchronous AF_LOCAL calls,
1953 		 * we'll need to figure out how to pass a namespace to
1954 		 * connect.
1955 		 */
1956 		rpc_exit(task, -ENOTCONN);
1957 		return;
1958 	}
1959 	ret = xs_local_setup_socket(transport);
1960 	if (ret && !RPC_IS_SOFTCONN(task))
1961 		msleep_interruptible(15000);
1962 }
1963 
1964 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1965 /*
1966  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1967  * know that we have exclusive access to the socket), to guard against
1968  * races with xs_reset_transport.
1969  */
1970 static void xs_set_memalloc(struct rpc_xprt *xprt)
1971 {
1972 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1973 			xprt);
1974 
1975 	/*
1976 	 * If there's no sock, then we have nothing to set. The
1977 	 * reconnecting process will get it for us.
1978 	 */
1979 	if (!transport->inet)
1980 		return;
1981 	if (atomic_read(&xprt->swapper))
1982 		sk_set_memalloc(transport->inet);
1983 }
1984 
1985 /**
1986  * xs_enable_swap - Tag this transport as being used for swap.
1987  * @xprt: transport to tag
1988  *
1989  * Take a reference to this transport on behalf of the rpc_clnt, and
1990  * optionally mark it for swapping if it wasn't already.
1991  */
1992 static int
1993 xs_enable_swap(struct rpc_xprt *xprt)
1994 {
1995 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1996 
1997 	if (atomic_inc_return(&xprt->swapper) != 1)
1998 		return 0;
1999 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2000 		return -ERESTARTSYS;
2001 	if (xs->inet)
2002 		sk_set_memalloc(xs->inet);
2003 	xprt_release_xprt(xprt, NULL);
2004 	return 0;
2005 }
2006 
2007 /**
2008  * xs_disable_swap - Untag this transport as being used for swap.
2009  * @xprt: transport to tag
2010  *
2011  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2012  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2013  */
2014 static void
2015 xs_disable_swap(struct rpc_xprt *xprt)
2016 {
2017 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2018 
2019 	if (!atomic_dec_and_test(&xprt->swapper))
2020 		return;
2021 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2022 		return;
2023 	if (xs->inet)
2024 		sk_clear_memalloc(xs->inet);
2025 	xprt_release_xprt(xprt, NULL);
2026 }
2027 #else
2028 static void xs_set_memalloc(struct rpc_xprt *xprt)
2029 {
2030 }
2031 
2032 static int
2033 xs_enable_swap(struct rpc_xprt *xprt)
2034 {
2035 	return -EINVAL;
2036 }
2037 
2038 static void
2039 xs_disable_swap(struct rpc_xprt *xprt)
2040 {
2041 }
2042 #endif
2043 
2044 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2045 {
2046 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2047 
2048 	if (!transport->inet) {
2049 		struct sock *sk = sock->sk;
2050 
2051 		write_lock_bh(&sk->sk_callback_lock);
2052 
2053 		xs_save_old_callbacks(transport, sk);
2054 
2055 		sk->sk_user_data = xprt;
2056 		sk->sk_data_ready = xs_data_ready;
2057 		sk->sk_write_space = xs_udp_write_space;
2058 		sock_set_flag(sk, SOCK_FASYNC);
2059 		sk->sk_allocation = GFP_NOIO;
2060 
2061 		xprt_set_connected(xprt);
2062 
2063 		/* Reset to new socket */
2064 		transport->sock = sock;
2065 		transport->inet = sk;
2066 
2067 		xs_set_memalloc(xprt);
2068 
2069 		write_unlock_bh(&sk->sk_callback_lock);
2070 	}
2071 	xs_udp_do_set_buffer_size(xprt);
2072 
2073 	xprt->stat.connect_start = jiffies;
2074 }
2075 
2076 static void xs_udp_setup_socket(struct work_struct *work)
2077 {
2078 	struct sock_xprt *transport =
2079 		container_of(work, struct sock_xprt, connect_worker.work);
2080 	struct rpc_xprt *xprt = &transport->xprt;
2081 	struct socket *sock;
2082 	int status = -EIO;
2083 
2084 	sock = xs_create_sock(xprt, transport,
2085 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2086 			IPPROTO_UDP, false);
2087 	if (IS_ERR(sock))
2088 		goto out;
2089 
2090 	dprintk("RPC:       worker connecting xprt %p via %s to "
2091 				"%s (port %s)\n", xprt,
2092 			xprt->address_strings[RPC_DISPLAY_PROTO],
2093 			xprt->address_strings[RPC_DISPLAY_ADDR],
2094 			xprt->address_strings[RPC_DISPLAY_PORT]);
2095 
2096 	xs_udp_finish_connecting(xprt, sock);
2097 	trace_rpc_socket_connect(xprt, sock, 0);
2098 	status = 0;
2099 out:
2100 	xprt_unlock_connect(xprt, transport);
2101 	xprt_clear_connecting(xprt);
2102 	xprt_wake_pending_tasks(xprt, status);
2103 }
2104 
2105 /**
2106  * xs_tcp_shutdown - gracefully shut down a TCP socket
2107  * @xprt: transport
2108  *
2109  * Initiates a graceful shutdown of the TCP socket by calling the
2110  * equivalent of shutdown(SHUT_RDWR);
2111  */
2112 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2113 {
2114 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2115 	struct socket *sock = transport->sock;
2116 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2117 
2118 	if (sock == NULL)
2119 		return;
2120 	switch (skst) {
2121 	default:
2122 		kernel_sock_shutdown(sock, SHUT_RDWR);
2123 		trace_rpc_socket_shutdown(xprt, sock);
2124 		break;
2125 	case TCP_CLOSE:
2126 	case TCP_TIME_WAIT:
2127 		xs_reset_transport(transport);
2128 	}
2129 }
2130 
2131 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2132 		struct socket *sock)
2133 {
2134 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2135 	unsigned int keepidle;
2136 	unsigned int keepcnt;
2137 	unsigned int opt_on = 1;
2138 	unsigned int timeo;
2139 
2140 	spin_lock_bh(&xprt->transport_lock);
2141 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2142 	keepcnt = xprt->timeout->to_retries + 1;
2143 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2144 		(xprt->timeout->to_retries + 1);
2145 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2146 	spin_unlock_bh(&xprt->transport_lock);
2147 
2148 	/* TCP Keepalive options */
2149 	kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2150 			(char *)&opt_on, sizeof(opt_on));
2151 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2152 			(char *)&keepidle, sizeof(keepidle));
2153 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2154 			(char *)&keepidle, sizeof(keepidle));
2155 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2156 			(char *)&keepcnt, sizeof(keepcnt));
2157 
2158 	/* TCP user timeout (see RFC5482) */
2159 	kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2160 			(char *)&timeo, sizeof(timeo));
2161 }
2162 
2163 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2164 		unsigned long connect_timeout,
2165 		unsigned long reconnect_timeout)
2166 {
2167 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2168 	struct rpc_timeout to;
2169 	unsigned long initval;
2170 
2171 	spin_lock_bh(&xprt->transport_lock);
2172 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2173 		xprt->max_reconnect_timeout = reconnect_timeout;
2174 	if (connect_timeout < xprt->connect_timeout) {
2175 		memcpy(&to, xprt->timeout, sizeof(to));
2176 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2177 		/* Arbitrary lower limit */
2178 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2179 			initval = XS_TCP_INIT_REEST_TO << 1;
2180 		to.to_initval = initval;
2181 		to.to_maxval = initval;
2182 		memcpy(&transport->tcp_timeout, &to,
2183 				sizeof(transport->tcp_timeout));
2184 		xprt->timeout = &transport->tcp_timeout;
2185 		xprt->connect_timeout = connect_timeout;
2186 	}
2187 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2188 	spin_unlock_bh(&xprt->transport_lock);
2189 }
2190 
2191 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2192 {
2193 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2194 	int ret = -ENOTCONN;
2195 
2196 	if (!transport->inet) {
2197 		struct sock *sk = sock->sk;
2198 		unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2199 
2200 		/* Avoid temporary address, they are bad for long-lived
2201 		 * connections such as NFS mounts.
2202 		 * RFC4941, section 3.6 suggests that:
2203 		 *    Individual applications, which have specific
2204 		 *    knowledge about the normal duration of connections,
2205 		 *    MAY override this as appropriate.
2206 		 */
2207 		kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2208 				(char *)&addr_pref, sizeof(addr_pref));
2209 
2210 		xs_tcp_set_socket_timeouts(xprt, sock);
2211 
2212 		write_lock_bh(&sk->sk_callback_lock);
2213 
2214 		xs_save_old_callbacks(transport, sk);
2215 
2216 		sk->sk_user_data = xprt;
2217 		sk->sk_data_ready = xs_data_ready;
2218 		sk->sk_state_change = xs_tcp_state_change;
2219 		sk->sk_write_space = xs_tcp_write_space;
2220 		sock_set_flag(sk, SOCK_FASYNC);
2221 		sk->sk_error_report = xs_error_report;
2222 		sk->sk_allocation = GFP_NOIO;
2223 
2224 		/* socket options */
2225 		sock_reset_flag(sk, SOCK_LINGER);
2226 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2227 
2228 		xprt_clear_connected(xprt);
2229 
2230 		/* Reset to new socket */
2231 		transport->sock = sock;
2232 		transport->inet = sk;
2233 
2234 		write_unlock_bh(&sk->sk_callback_lock);
2235 	}
2236 
2237 	if (!xprt_bound(xprt))
2238 		goto out;
2239 
2240 	xs_set_memalloc(xprt);
2241 
2242 	/* Reset TCP record info */
2243 	xs_stream_reset_connect(transport);
2244 
2245 	/* Tell the socket layer to start connecting... */
2246 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2247 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2248 	switch (ret) {
2249 	case 0:
2250 		xs_set_srcport(transport, sock);
2251 		/* fall through */
2252 	case -EINPROGRESS:
2253 		/* SYN_SENT! */
2254 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2255 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2256 		break;
2257 	case -EADDRNOTAVAIL:
2258 		/* Source port number is unavailable. Try a new one! */
2259 		transport->srcport = 0;
2260 	}
2261 out:
2262 	return ret;
2263 }
2264 
2265 /**
2266  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2267  *
2268  * Invoked by a work queue tasklet.
2269  */
2270 static void xs_tcp_setup_socket(struct work_struct *work)
2271 {
2272 	struct sock_xprt *transport =
2273 		container_of(work, struct sock_xprt, connect_worker.work);
2274 	struct socket *sock = transport->sock;
2275 	struct rpc_xprt *xprt = &transport->xprt;
2276 	int status = -EIO;
2277 
2278 	if (!sock) {
2279 		sock = xs_create_sock(xprt, transport,
2280 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2281 				IPPROTO_TCP, true);
2282 		if (IS_ERR(sock)) {
2283 			status = PTR_ERR(sock);
2284 			goto out;
2285 		}
2286 	}
2287 
2288 	dprintk("RPC:       worker connecting xprt %p via %s to "
2289 				"%s (port %s)\n", xprt,
2290 			xprt->address_strings[RPC_DISPLAY_PROTO],
2291 			xprt->address_strings[RPC_DISPLAY_ADDR],
2292 			xprt->address_strings[RPC_DISPLAY_PORT]);
2293 
2294 	status = xs_tcp_finish_connecting(xprt, sock);
2295 	trace_rpc_socket_connect(xprt, sock, status);
2296 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2297 			xprt, -status, xprt_connected(xprt),
2298 			sock->sk->sk_state);
2299 	switch (status) {
2300 	default:
2301 		printk("%s: connect returned unhandled error %d\n",
2302 			__func__, status);
2303 		/* fall through */
2304 	case -EADDRNOTAVAIL:
2305 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2306 		 * and retry
2307 		 */
2308 		xs_tcp_force_close(xprt);
2309 		break;
2310 	case 0:
2311 	case -EINPROGRESS:
2312 	case -EALREADY:
2313 		xprt_unlock_connect(xprt, transport);
2314 		return;
2315 	case -EINVAL:
2316 		/* Happens, for instance, if the user specified a link
2317 		 * local IPv6 address without a scope-id.
2318 		 */
2319 	case -ECONNREFUSED:
2320 	case -ECONNRESET:
2321 	case -ENETDOWN:
2322 	case -ENETUNREACH:
2323 	case -EHOSTUNREACH:
2324 	case -EADDRINUSE:
2325 	case -ENOBUFS:
2326 		/*
2327 		 * xs_tcp_force_close() wakes tasks with -EIO.
2328 		 * We need to wake them first to ensure the
2329 		 * correct error code.
2330 		 */
2331 		xprt_wake_pending_tasks(xprt, status);
2332 		xs_tcp_force_close(xprt);
2333 		goto out;
2334 	}
2335 	status = -EAGAIN;
2336 out:
2337 	xprt_unlock_connect(xprt, transport);
2338 	xprt_clear_connecting(xprt);
2339 	xprt_wake_pending_tasks(xprt, status);
2340 }
2341 
2342 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2343 {
2344 	unsigned long start, now = jiffies;
2345 
2346 	start = xprt->stat.connect_start + xprt->reestablish_timeout;
2347 	if (time_after(start, now))
2348 		return start - now;
2349 	return 0;
2350 }
2351 
2352 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2353 {
2354 	xprt->reestablish_timeout <<= 1;
2355 	if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2356 		xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2357 	if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2358 		xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2359 }
2360 
2361 /**
2362  * xs_connect - connect a socket to a remote endpoint
2363  * @xprt: pointer to transport structure
2364  * @task: address of RPC task that manages state of connect request
2365  *
2366  * TCP: If the remote end dropped the connection, delay reconnecting.
2367  *
2368  * UDP socket connects are synchronous, but we use a work queue anyway
2369  * to guarantee that even unprivileged user processes can set up a
2370  * socket on a privileged port.
2371  *
2372  * If a UDP socket connect fails, the delay behavior here prevents
2373  * retry floods (hard mounts).
2374  */
2375 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2376 {
2377 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2378 	unsigned long delay = 0;
2379 
2380 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2381 
2382 	if (transport->sock != NULL) {
2383 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2384 				"seconds\n",
2385 				xprt, xprt->reestablish_timeout / HZ);
2386 
2387 		/* Start by resetting any existing state */
2388 		xs_reset_transport(transport);
2389 
2390 		delay = xs_reconnect_delay(xprt);
2391 		xs_reconnect_backoff(xprt);
2392 
2393 	} else
2394 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2395 
2396 	queue_delayed_work(xprtiod_workqueue,
2397 			&transport->connect_worker,
2398 			delay);
2399 }
2400 
2401 /**
2402  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2403  * @xprt: rpc_xprt struct containing statistics
2404  * @seq: output file
2405  *
2406  */
2407 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2408 {
2409 	long idle_time = 0;
2410 
2411 	if (xprt_connected(xprt))
2412 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2413 
2414 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2415 			"%llu %llu %lu %llu %llu\n",
2416 			xprt->stat.bind_count,
2417 			xprt->stat.connect_count,
2418 			xprt->stat.connect_time / HZ,
2419 			idle_time,
2420 			xprt->stat.sends,
2421 			xprt->stat.recvs,
2422 			xprt->stat.bad_xids,
2423 			xprt->stat.req_u,
2424 			xprt->stat.bklog_u,
2425 			xprt->stat.max_slots,
2426 			xprt->stat.sending_u,
2427 			xprt->stat.pending_u);
2428 }
2429 
2430 /**
2431  * xs_udp_print_stats - display UDP socket-specifc stats
2432  * @xprt: rpc_xprt struct containing statistics
2433  * @seq: output file
2434  *
2435  */
2436 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2437 {
2438 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2439 
2440 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2441 			"%lu %llu %llu\n",
2442 			transport->srcport,
2443 			xprt->stat.bind_count,
2444 			xprt->stat.sends,
2445 			xprt->stat.recvs,
2446 			xprt->stat.bad_xids,
2447 			xprt->stat.req_u,
2448 			xprt->stat.bklog_u,
2449 			xprt->stat.max_slots,
2450 			xprt->stat.sending_u,
2451 			xprt->stat.pending_u);
2452 }
2453 
2454 /**
2455  * xs_tcp_print_stats - display TCP socket-specifc stats
2456  * @xprt: rpc_xprt struct containing statistics
2457  * @seq: output file
2458  *
2459  */
2460 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2461 {
2462 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2463 	long idle_time = 0;
2464 
2465 	if (xprt_connected(xprt))
2466 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2467 
2468 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2469 			"%llu %llu %lu %llu %llu\n",
2470 			transport->srcport,
2471 			xprt->stat.bind_count,
2472 			xprt->stat.connect_count,
2473 			xprt->stat.connect_time / HZ,
2474 			idle_time,
2475 			xprt->stat.sends,
2476 			xprt->stat.recvs,
2477 			xprt->stat.bad_xids,
2478 			xprt->stat.req_u,
2479 			xprt->stat.bklog_u,
2480 			xprt->stat.max_slots,
2481 			xprt->stat.sending_u,
2482 			xprt->stat.pending_u);
2483 }
2484 
2485 /*
2486  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2487  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2488  * to use the server side send routines.
2489  */
2490 static int bc_malloc(struct rpc_task *task)
2491 {
2492 	struct rpc_rqst *rqst = task->tk_rqstp;
2493 	size_t size = rqst->rq_callsize;
2494 	struct page *page;
2495 	struct rpc_buffer *buf;
2496 
2497 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2498 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2499 			  size);
2500 		return -EINVAL;
2501 	}
2502 
2503 	page = alloc_page(GFP_KERNEL);
2504 	if (!page)
2505 		return -ENOMEM;
2506 
2507 	buf = page_address(page);
2508 	buf->len = PAGE_SIZE;
2509 
2510 	rqst->rq_buffer = buf->data;
2511 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2512 	return 0;
2513 }
2514 
2515 /*
2516  * Free the space allocated in the bc_alloc routine
2517  */
2518 static void bc_free(struct rpc_task *task)
2519 {
2520 	void *buffer = task->tk_rqstp->rq_buffer;
2521 	struct rpc_buffer *buf;
2522 
2523 	buf = container_of(buffer, struct rpc_buffer, data);
2524 	free_page((unsigned long)buf);
2525 }
2526 
2527 /*
2528  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2529  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2530  */
2531 static int bc_sendto(struct rpc_rqst *req)
2532 {
2533 	int len;
2534 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2535 	struct rpc_xprt *xprt = req->rq_xprt;
2536 	struct sock_xprt *transport =
2537 				container_of(xprt, struct sock_xprt, xprt);
2538 	struct socket *sock = transport->sock;
2539 	unsigned long headoff;
2540 	unsigned long tailoff;
2541 
2542 	xs_encode_stream_record_marker(xbufp);
2543 
2544 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2545 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2546 	len = svc_send_common(sock, xbufp,
2547 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2548 			      xbufp->tail[0].iov_base, tailoff);
2549 
2550 	if (len != xbufp->len) {
2551 		printk(KERN_NOTICE "Error sending entire callback!\n");
2552 		len = -EAGAIN;
2553 	}
2554 
2555 	return len;
2556 }
2557 
2558 /*
2559  * The send routine. Borrows from svc_send
2560  */
2561 static int bc_send_request(struct rpc_rqst *req)
2562 {
2563 	struct svc_xprt	*xprt;
2564 	int len;
2565 
2566 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2567 	/*
2568 	 * Get the server socket associated with this callback xprt
2569 	 */
2570 	xprt = req->rq_xprt->bc_xprt;
2571 
2572 	/*
2573 	 * Grab the mutex to serialize data as the connection is shared
2574 	 * with the fore channel
2575 	 */
2576 	mutex_lock(&xprt->xpt_mutex);
2577 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2578 		len = -ENOTCONN;
2579 	else
2580 		len = bc_sendto(req);
2581 	mutex_unlock(&xprt->xpt_mutex);
2582 
2583 	if (len > 0)
2584 		len = 0;
2585 
2586 	return len;
2587 }
2588 
2589 /*
2590  * The close routine. Since this is client initiated, we do nothing
2591  */
2592 
2593 static void bc_close(struct rpc_xprt *xprt)
2594 {
2595 }
2596 
2597 /*
2598  * The xprt destroy routine. Again, because this connection is client
2599  * initiated, we do nothing
2600  */
2601 
2602 static void bc_destroy(struct rpc_xprt *xprt)
2603 {
2604 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2605 
2606 	xs_xprt_free(xprt);
2607 	module_put(THIS_MODULE);
2608 }
2609 
2610 static const struct rpc_xprt_ops xs_local_ops = {
2611 	.reserve_xprt		= xprt_reserve_xprt,
2612 	.release_xprt		= xprt_release_xprt,
2613 	.alloc_slot		= xprt_alloc_slot,
2614 	.free_slot		= xprt_free_slot,
2615 	.rpcbind		= xs_local_rpcbind,
2616 	.set_port		= xs_local_set_port,
2617 	.connect		= xs_local_connect,
2618 	.buf_alloc		= rpc_malloc,
2619 	.buf_free		= rpc_free,
2620 	.prepare_request	= xs_stream_prepare_request,
2621 	.send_request		= xs_local_send_request,
2622 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2623 	.close			= xs_close,
2624 	.destroy		= xs_destroy,
2625 	.print_stats		= xs_local_print_stats,
2626 	.enable_swap		= xs_enable_swap,
2627 	.disable_swap		= xs_disable_swap,
2628 };
2629 
2630 static const struct rpc_xprt_ops xs_udp_ops = {
2631 	.set_buffer_size	= xs_udp_set_buffer_size,
2632 	.reserve_xprt		= xprt_reserve_xprt_cong,
2633 	.release_xprt		= xprt_release_xprt_cong,
2634 	.alloc_slot		= xprt_alloc_slot,
2635 	.free_slot		= xprt_free_slot,
2636 	.rpcbind		= rpcb_getport_async,
2637 	.set_port		= xs_set_port,
2638 	.connect		= xs_connect,
2639 	.buf_alloc		= rpc_malloc,
2640 	.buf_free		= rpc_free,
2641 	.send_request		= xs_udp_send_request,
2642 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2643 	.timer			= xs_udp_timer,
2644 	.release_request	= xprt_release_rqst_cong,
2645 	.close			= xs_close,
2646 	.destroy		= xs_destroy,
2647 	.print_stats		= xs_udp_print_stats,
2648 	.enable_swap		= xs_enable_swap,
2649 	.disable_swap		= xs_disable_swap,
2650 	.inject_disconnect	= xs_inject_disconnect,
2651 };
2652 
2653 static const struct rpc_xprt_ops xs_tcp_ops = {
2654 	.reserve_xprt		= xprt_reserve_xprt,
2655 	.release_xprt		= xprt_release_xprt,
2656 	.alloc_slot		= xprt_alloc_slot,
2657 	.free_slot		= xprt_free_slot,
2658 	.rpcbind		= rpcb_getport_async,
2659 	.set_port		= xs_set_port,
2660 	.connect		= xs_connect,
2661 	.buf_alloc		= rpc_malloc,
2662 	.buf_free		= rpc_free,
2663 	.prepare_request	= xs_stream_prepare_request,
2664 	.send_request		= xs_tcp_send_request,
2665 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2666 	.close			= xs_tcp_shutdown,
2667 	.destroy		= xs_destroy,
2668 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2669 	.print_stats		= xs_tcp_print_stats,
2670 	.enable_swap		= xs_enable_swap,
2671 	.disable_swap		= xs_disable_swap,
2672 	.inject_disconnect	= xs_inject_disconnect,
2673 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2674 	.bc_setup		= xprt_setup_bc,
2675 	.bc_up			= xs_tcp_bc_up,
2676 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2677 	.bc_free_rqst		= xprt_free_bc_rqst,
2678 	.bc_destroy		= xprt_destroy_bc,
2679 #endif
2680 };
2681 
2682 /*
2683  * The rpc_xprt_ops for the server backchannel
2684  */
2685 
2686 static const struct rpc_xprt_ops bc_tcp_ops = {
2687 	.reserve_xprt		= xprt_reserve_xprt,
2688 	.release_xprt		= xprt_release_xprt,
2689 	.alloc_slot		= xprt_alloc_slot,
2690 	.free_slot		= xprt_free_slot,
2691 	.buf_alloc		= bc_malloc,
2692 	.buf_free		= bc_free,
2693 	.send_request		= bc_send_request,
2694 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2695 	.close			= bc_close,
2696 	.destroy		= bc_destroy,
2697 	.print_stats		= xs_tcp_print_stats,
2698 	.enable_swap		= xs_enable_swap,
2699 	.disable_swap		= xs_disable_swap,
2700 	.inject_disconnect	= xs_inject_disconnect,
2701 };
2702 
2703 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2704 {
2705 	static const struct sockaddr_in sin = {
2706 		.sin_family		= AF_INET,
2707 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2708 	};
2709 	static const struct sockaddr_in6 sin6 = {
2710 		.sin6_family		= AF_INET6,
2711 		.sin6_addr		= IN6ADDR_ANY_INIT,
2712 	};
2713 
2714 	switch (family) {
2715 	case AF_LOCAL:
2716 		break;
2717 	case AF_INET:
2718 		memcpy(sap, &sin, sizeof(sin));
2719 		break;
2720 	case AF_INET6:
2721 		memcpy(sap, &sin6, sizeof(sin6));
2722 		break;
2723 	default:
2724 		dprintk("RPC:       %s: Bad address family\n", __func__);
2725 		return -EAFNOSUPPORT;
2726 	}
2727 	return 0;
2728 }
2729 
2730 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2731 				      unsigned int slot_table_size,
2732 				      unsigned int max_slot_table_size)
2733 {
2734 	struct rpc_xprt *xprt;
2735 	struct sock_xprt *new;
2736 
2737 	if (args->addrlen > sizeof(xprt->addr)) {
2738 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2739 		return ERR_PTR(-EBADF);
2740 	}
2741 
2742 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2743 			max_slot_table_size);
2744 	if (xprt == NULL) {
2745 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2746 				"rpc_xprt\n");
2747 		return ERR_PTR(-ENOMEM);
2748 	}
2749 
2750 	new = container_of(xprt, struct sock_xprt, xprt);
2751 	mutex_init(&new->recv_mutex);
2752 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2753 	xprt->addrlen = args->addrlen;
2754 	if (args->srcaddr)
2755 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2756 	else {
2757 		int err;
2758 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2759 					(struct sockaddr *)&new->srcaddr);
2760 		if (err != 0) {
2761 			xprt_free(xprt);
2762 			return ERR_PTR(err);
2763 		}
2764 	}
2765 
2766 	return xprt;
2767 }
2768 
2769 static const struct rpc_timeout xs_local_default_timeout = {
2770 	.to_initval = 10 * HZ,
2771 	.to_maxval = 10 * HZ,
2772 	.to_retries = 2,
2773 };
2774 
2775 /**
2776  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2777  * @args: rpc transport creation arguments
2778  *
2779  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2780  */
2781 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2782 {
2783 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2784 	struct sock_xprt *transport;
2785 	struct rpc_xprt *xprt;
2786 	struct rpc_xprt *ret;
2787 
2788 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2789 			xprt_max_tcp_slot_table_entries);
2790 	if (IS_ERR(xprt))
2791 		return xprt;
2792 	transport = container_of(xprt, struct sock_xprt, xprt);
2793 
2794 	xprt->prot = 0;
2795 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2796 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2797 
2798 	xprt->bind_timeout = XS_BIND_TO;
2799 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2800 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2801 
2802 	xprt->ops = &xs_local_ops;
2803 	xprt->timeout = &xs_local_default_timeout;
2804 
2805 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2806 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2807 
2808 	switch (sun->sun_family) {
2809 	case AF_LOCAL:
2810 		if (sun->sun_path[0] != '/') {
2811 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2812 					sun->sun_path);
2813 			ret = ERR_PTR(-EINVAL);
2814 			goto out_err;
2815 		}
2816 		xprt_set_bound(xprt);
2817 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2818 		ret = ERR_PTR(xs_local_setup_socket(transport));
2819 		if (ret)
2820 			goto out_err;
2821 		break;
2822 	default:
2823 		ret = ERR_PTR(-EAFNOSUPPORT);
2824 		goto out_err;
2825 	}
2826 
2827 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2828 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2829 
2830 	if (try_module_get(THIS_MODULE))
2831 		return xprt;
2832 	ret = ERR_PTR(-EINVAL);
2833 out_err:
2834 	xs_xprt_free(xprt);
2835 	return ret;
2836 }
2837 
2838 static const struct rpc_timeout xs_udp_default_timeout = {
2839 	.to_initval = 5 * HZ,
2840 	.to_maxval = 30 * HZ,
2841 	.to_increment = 5 * HZ,
2842 	.to_retries = 5,
2843 };
2844 
2845 /**
2846  * xs_setup_udp - Set up transport to use a UDP socket
2847  * @args: rpc transport creation arguments
2848  *
2849  */
2850 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2851 {
2852 	struct sockaddr *addr = args->dstaddr;
2853 	struct rpc_xprt *xprt;
2854 	struct sock_xprt *transport;
2855 	struct rpc_xprt *ret;
2856 
2857 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2858 			xprt_udp_slot_table_entries);
2859 	if (IS_ERR(xprt))
2860 		return xprt;
2861 	transport = container_of(xprt, struct sock_xprt, xprt);
2862 
2863 	xprt->prot = IPPROTO_UDP;
2864 	xprt->tsh_size = 0;
2865 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2866 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2867 
2868 	xprt->bind_timeout = XS_BIND_TO;
2869 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2870 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2871 
2872 	xprt->ops = &xs_udp_ops;
2873 
2874 	xprt->timeout = &xs_udp_default_timeout;
2875 
2876 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2877 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2878 
2879 	switch (addr->sa_family) {
2880 	case AF_INET:
2881 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2882 			xprt_set_bound(xprt);
2883 
2884 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2885 		break;
2886 	case AF_INET6:
2887 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2888 			xprt_set_bound(xprt);
2889 
2890 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2891 		break;
2892 	default:
2893 		ret = ERR_PTR(-EAFNOSUPPORT);
2894 		goto out_err;
2895 	}
2896 
2897 	if (xprt_bound(xprt))
2898 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2899 				xprt->address_strings[RPC_DISPLAY_ADDR],
2900 				xprt->address_strings[RPC_DISPLAY_PORT],
2901 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2902 	else
2903 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2904 				xprt->address_strings[RPC_DISPLAY_ADDR],
2905 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2906 
2907 	if (try_module_get(THIS_MODULE))
2908 		return xprt;
2909 	ret = ERR_PTR(-EINVAL);
2910 out_err:
2911 	xs_xprt_free(xprt);
2912 	return ret;
2913 }
2914 
2915 static const struct rpc_timeout xs_tcp_default_timeout = {
2916 	.to_initval = 60 * HZ,
2917 	.to_maxval = 60 * HZ,
2918 	.to_retries = 2,
2919 };
2920 
2921 /**
2922  * xs_setup_tcp - Set up transport to use a TCP socket
2923  * @args: rpc transport creation arguments
2924  *
2925  */
2926 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2927 {
2928 	struct sockaddr *addr = args->dstaddr;
2929 	struct rpc_xprt *xprt;
2930 	struct sock_xprt *transport;
2931 	struct rpc_xprt *ret;
2932 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2933 
2934 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2935 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2936 
2937 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2938 			max_slot_table_size);
2939 	if (IS_ERR(xprt))
2940 		return xprt;
2941 	transport = container_of(xprt, struct sock_xprt, xprt);
2942 
2943 	xprt->prot = IPPROTO_TCP;
2944 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2945 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2946 
2947 	xprt->bind_timeout = XS_BIND_TO;
2948 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2949 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2950 
2951 	xprt->ops = &xs_tcp_ops;
2952 	xprt->timeout = &xs_tcp_default_timeout;
2953 
2954 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2955 	xprt->connect_timeout = xprt->timeout->to_initval *
2956 		(xprt->timeout->to_retries + 1);
2957 
2958 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2959 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2960 
2961 	switch (addr->sa_family) {
2962 	case AF_INET:
2963 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2964 			xprt_set_bound(xprt);
2965 
2966 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2967 		break;
2968 	case AF_INET6:
2969 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2970 			xprt_set_bound(xprt);
2971 
2972 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2973 		break;
2974 	default:
2975 		ret = ERR_PTR(-EAFNOSUPPORT);
2976 		goto out_err;
2977 	}
2978 
2979 	if (xprt_bound(xprt))
2980 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2981 				xprt->address_strings[RPC_DISPLAY_ADDR],
2982 				xprt->address_strings[RPC_DISPLAY_PORT],
2983 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2984 	else
2985 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2986 				xprt->address_strings[RPC_DISPLAY_ADDR],
2987 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2988 
2989 	if (try_module_get(THIS_MODULE))
2990 		return xprt;
2991 	ret = ERR_PTR(-EINVAL);
2992 out_err:
2993 	xs_xprt_free(xprt);
2994 	return ret;
2995 }
2996 
2997 /**
2998  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2999  * @args: rpc transport creation arguments
3000  *
3001  */
3002 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3003 {
3004 	struct sockaddr *addr = args->dstaddr;
3005 	struct rpc_xprt *xprt;
3006 	struct sock_xprt *transport;
3007 	struct svc_sock *bc_sock;
3008 	struct rpc_xprt *ret;
3009 
3010 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3011 			xprt_tcp_slot_table_entries);
3012 	if (IS_ERR(xprt))
3013 		return xprt;
3014 	transport = container_of(xprt, struct sock_xprt, xprt);
3015 
3016 	xprt->prot = IPPROTO_TCP;
3017 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3018 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3019 	xprt->timeout = &xs_tcp_default_timeout;
3020 
3021 	/* backchannel */
3022 	xprt_set_bound(xprt);
3023 	xprt->bind_timeout = 0;
3024 	xprt->reestablish_timeout = 0;
3025 	xprt->idle_timeout = 0;
3026 
3027 	xprt->ops = &bc_tcp_ops;
3028 
3029 	switch (addr->sa_family) {
3030 	case AF_INET:
3031 		xs_format_peer_addresses(xprt, "tcp",
3032 					 RPCBIND_NETID_TCP);
3033 		break;
3034 	case AF_INET6:
3035 		xs_format_peer_addresses(xprt, "tcp",
3036 				   RPCBIND_NETID_TCP6);
3037 		break;
3038 	default:
3039 		ret = ERR_PTR(-EAFNOSUPPORT);
3040 		goto out_err;
3041 	}
3042 
3043 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3044 			xprt->address_strings[RPC_DISPLAY_ADDR],
3045 			xprt->address_strings[RPC_DISPLAY_PORT],
3046 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3047 
3048 	/*
3049 	 * Once we've associated a backchannel xprt with a connection,
3050 	 * we want to keep it around as long as the connection lasts,
3051 	 * in case we need to start using it for a backchannel again;
3052 	 * this reference won't be dropped until bc_xprt is destroyed.
3053 	 */
3054 	xprt_get(xprt);
3055 	args->bc_xprt->xpt_bc_xprt = xprt;
3056 	xprt->bc_xprt = args->bc_xprt;
3057 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3058 	transport->sock = bc_sock->sk_sock;
3059 	transport->inet = bc_sock->sk_sk;
3060 
3061 	/*
3062 	 * Since we don't want connections for the backchannel, we set
3063 	 * the xprt status to connected
3064 	 */
3065 	xprt_set_connected(xprt);
3066 
3067 	if (try_module_get(THIS_MODULE))
3068 		return xprt;
3069 
3070 	args->bc_xprt->xpt_bc_xprt = NULL;
3071 	args->bc_xprt->xpt_bc_xps = NULL;
3072 	xprt_put(xprt);
3073 	ret = ERR_PTR(-EINVAL);
3074 out_err:
3075 	xs_xprt_free(xprt);
3076 	return ret;
3077 }
3078 
3079 static struct xprt_class	xs_local_transport = {
3080 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3081 	.name		= "named UNIX socket",
3082 	.owner		= THIS_MODULE,
3083 	.ident		= XPRT_TRANSPORT_LOCAL,
3084 	.setup		= xs_setup_local,
3085 };
3086 
3087 static struct xprt_class	xs_udp_transport = {
3088 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3089 	.name		= "udp",
3090 	.owner		= THIS_MODULE,
3091 	.ident		= XPRT_TRANSPORT_UDP,
3092 	.setup		= xs_setup_udp,
3093 };
3094 
3095 static struct xprt_class	xs_tcp_transport = {
3096 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3097 	.name		= "tcp",
3098 	.owner		= THIS_MODULE,
3099 	.ident		= XPRT_TRANSPORT_TCP,
3100 	.setup		= xs_setup_tcp,
3101 };
3102 
3103 static struct xprt_class	xs_bc_tcp_transport = {
3104 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3105 	.name		= "tcp NFSv4.1 backchannel",
3106 	.owner		= THIS_MODULE,
3107 	.ident		= XPRT_TRANSPORT_BC_TCP,
3108 	.setup		= xs_setup_bc_tcp,
3109 };
3110 
3111 /**
3112  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3113  *
3114  */
3115 int init_socket_xprt(void)
3116 {
3117 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3118 	if (!sunrpc_table_header)
3119 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3120 #endif
3121 
3122 	xprt_register_transport(&xs_local_transport);
3123 	xprt_register_transport(&xs_udp_transport);
3124 	xprt_register_transport(&xs_tcp_transport);
3125 	xprt_register_transport(&xs_bc_tcp_transport);
3126 
3127 	return 0;
3128 }
3129 
3130 /**
3131  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3132  *
3133  */
3134 void cleanup_socket_xprt(void)
3135 {
3136 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3137 	if (sunrpc_table_header) {
3138 		unregister_sysctl_table(sunrpc_table_header);
3139 		sunrpc_table_header = NULL;
3140 	}
3141 #endif
3142 
3143 	xprt_unregister_transport(&xs_local_transport);
3144 	xprt_unregister_transport(&xs_udp_transport);
3145 	xprt_unregister_transport(&xs_tcp_transport);
3146 	xprt_unregister_transport(&xs_bc_tcp_transport);
3147 }
3148 
3149 static int param_set_uint_minmax(const char *val,
3150 		const struct kernel_param *kp,
3151 		unsigned int min, unsigned int max)
3152 {
3153 	unsigned int num;
3154 	int ret;
3155 
3156 	if (!val)
3157 		return -EINVAL;
3158 	ret = kstrtouint(val, 0, &num);
3159 	if (ret)
3160 		return ret;
3161 	if (num < min || num > max)
3162 		return -EINVAL;
3163 	*((unsigned int *)kp->arg) = num;
3164 	return 0;
3165 }
3166 
3167 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3168 {
3169 	return param_set_uint_minmax(val, kp,
3170 			RPC_MIN_RESVPORT,
3171 			RPC_MAX_RESVPORT);
3172 }
3173 
3174 static const struct kernel_param_ops param_ops_portnr = {
3175 	.set = param_set_portnr,
3176 	.get = param_get_uint,
3177 };
3178 
3179 #define param_check_portnr(name, p) \
3180 	__param_check(name, p, unsigned int);
3181 
3182 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3183 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3184 
3185 static int param_set_slot_table_size(const char *val,
3186 				     const struct kernel_param *kp)
3187 {
3188 	return param_set_uint_minmax(val, kp,
3189 			RPC_MIN_SLOT_TABLE,
3190 			RPC_MAX_SLOT_TABLE);
3191 }
3192 
3193 static const struct kernel_param_ops param_ops_slot_table_size = {
3194 	.set = param_set_slot_table_size,
3195 	.get = param_get_uint,
3196 };
3197 
3198 #define param_check_slot_table_size(name, p) \
3199 	__param_check(name, p, unsigned int);
3200 
3201 static int param_set_max_slot_table_size(const char *val,
3202 				     const struct kernel_param *kp)
3203 {
3204 	return param_set_uint_minmax(val, kp,
3205 			RPC_MIN_SLOT_TABLE,
3206 			RPC_MAX_SLOT_TABLE_LIMIT);
3207 }
3208 
3209 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3210 	.set = param_set_max_slot_table_size,
3211 	.get = param_get_uint,
3212 };
3213 
3214 #define param_check_max_slot_table_size(name, p) \
3215 	__param_check(name, p, unsigned int);
3216 
3217 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3218 		   slot_table_size, 0644);
3219 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3220 		   max_slot_table_size, 0644);
3221 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3222 		   slot_table_size, 0644);
3223