xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision c4a11bf4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/highmem.h>
52 #include <linux/uio.h>
53 #include <linux/sched/mm.h>
54 
55 #include <trace/events/sunrpc.h>
56 
57 #include "socklib.h"
58 #include "sunrpc.h"
59 
60 static void xs_close(struct rpc_xprt *xprt);
61 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
62 		struct socket *sock);
63 
64 /*
65  * xprtsock tunables
66  */
67 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
68 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
69 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
70 
71 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
72 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
73 
74 #define XS_TCP_LINGER_TO	(15U * HZ)
75 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
76 
77 /*
78  * We can register our own files under /proc/sys/sunrpc by
79  * calling register_sysctl_table() again.  The files in that
80  * directory become the union of all files registered there.
81  *
82  * We simply need to make sure that we don't collide with
83  * someone else's file names!
84  */
85 
86 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
87 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
88 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
89 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
90 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
91 
92 static struct ctl_table_header *sunrpc_table_header;
93 
94 static struct xprt_class xs_local_transport;
95 static struct xprt_class xs_udp_transport;
96 static struct xprt_class xs_tcp_transport;
97 static struct xprt_class xs_bc_tcp_transport;
98 
99 /*
100  * FIXME: changing the UDP slot table size should also resize the UDP
101  *        socket buffers for existing UDP transports
102  */
103 static struct ctl_table xs_tunables_table[] = {
104 	{
105 		.procname	= "udp_slot_table_entries",
106 		.data		= &xprt_udp_slot_table_entries,
107 		.maxlen		= sizeof(unsigned int),
108 		.mode		= 0644,
109 		.proc_handler	= proc_dointvec_minmax,
110 		.extra1		= &min_slot_table_size,
111 		.extra2		= &max_slot_table_size
112 	},
113 	{
114 		.procname	= "tcp_slot_table_entries",
115 		.data		= &xprt_tcp_slot_table_entries,
116 		.maxlen		= sizeof(unsigned int),
117 		.mode		= 0644,
118 		.proc_handler	= proc_dointvec_minmax,
119 		.extra1		= &min_slot_table_size,
120 		.extra2		= &max_slot_table_size
121 	},
122 	{
123 		.procname	= "tcp_max_slot_table_entries",
124 		.data		= &xprt_max_tcp_slot_table_entries,
125 		.maxlen		= sizeof(unsigned int),
126 		.mode		= 0644,
127 		.proc_handler	= proc_dointvec_minmax,
128 		.extra1		= &min_slot_table_size,
129 		.extra2		= &max_tcp_slot_table_limit
130 	},
131 	{
132 		.procname	= "min_resvport",
133 		.data		= &xprt_min_resvport,
134 		.maxlen		= sizeof(unsigned int),
135 		.mode		= 0644,
136 		.proc_handler	= proc_dointvec_minmax,
137 		.extra1		= &xprt_min_resvport_limit,
138 		.extra2		= &xprt_max_resvport_limit
139 	},
140 	{
141 		.procname	= "max_resvport",
142 		.data		= &xprt_max_resvport,
143 		.maxlen		= sizeof(unsigned int),
144 		.mode		= 0644,
145 		.proc_handler	= proc_dointvec_minmax,
146 		.extra1		= &xprt_min_resvport_limit,
147 		.extra2		= &xprt_max_resvport_limit
148 	},
149 	{
150 		.procname	= "tcp_fin_timeout",
151 		.data		= &xs_tcp_fin_timeout,
152 		.maxlen		= sizeof(xs_tcp_fin_timeout),
153 		.mode		= 0644,
154 		.proc_handler	= proc_dointvec_jiffies,
155 	},
156 	{ },
157 };
158 
159 static struct ctl_table sunrpc_table[] = {
160 	{
161 		.procname	= "sunrpc",
162 		.mode		= 0555,
163 		.child		= xs_tunables_table
164 	},
165 	{ },
166 };
167 
168 /*
169  * Wait duration for a reply from the RPC portmapper.
170  */
171 #define XS_BIND_TO		(60U * HZ)
172 
173 /*
174  * Delay if a UDP socket connect error occurs.  This is most likely some
175  * kind of resource problem on the local host.
176  */
177 #define XS_UDP_REEST_TO		(2U * HZ)
178 
179 /*
180  * The reestablish timeout allows clients to delay for a bit before attempting
181  * to reconnect to a server that just dropped our connection.
182  *
183  * We implement an exponential backoff when trying to reestablish a TCP
184  * transport connection with the server.  Some servers like to drop a TCP
185  * connection when they are overworked, so we start with a short timeout and
186  * increase over time if the server is down or not responding.
187  */
188 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
189 
190 /*
191  * TCP idle timeout; client drops the transport socket if it is idle
192  * for this long.  Note that we also timeout UDP sockets to prevent
193  * holding port numbers when there is no RPC traffic.
194  */
195 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
196 
197 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
198 # undef  RPC_DEBUG_DATA
199 # define RPCDBG_FACILITY	RPCDBG_TRANS
200 #endif
201 
202 #ifdef RPC_DEBUG_DATA
203 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
204 {
205 	u8 *buf = (u8 *) packet;
206 	int j;
207 
208 	dprintk("RPC:       %s\n", msg);
209 	for (j = 0; j < count && j < 128; j += 4) {
210 		if (!(j & 31)) {
211 			if (j)
212 				dprintk("\n");
213 			dprintk("0x%04x ", j);
214 		}
215 		dprintk("%02x%02x%02x%02x ",
216 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
217 	}
218 	dprintk("\n");
219 }
220 #else
221 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
222 {
223 	/* NOP */
224 }
225 #endif
226 
227 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
228 {
229 	return (struct rpc_xprt *) sk->sk_user_data;
230 }
231 
232 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
233 {
234 	return (struct sockaddr *) &xprt->addr;
235 }
236 
237 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
238 {
239 	return (struct sockaddr_un *) &xprt->addr;
240 }
241 
242 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
243 {
244 	return (struct sockaddr_in *) &xprt->addr;
245 }
246 
247 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
248 {
249 	return (struct sockaddr_in6 *) &xprt->addr;
250 }
251 
252 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
253 {
254 	struct sockaddr *sap = xs_addr(xprt);
255 	struct sockaddr_in6 *sin6;
256 	struct sockaddr_in *sin;
257 	struct sockaddr_un *sun;
258 	char buf[128];
259 
260 	switch (sap->sa_family) {
261 	case AF_LOCAL:
262 		sun = xs_addr_un(xprt);
263 		strlcpy(buf, sun->sun_path, sizeof(buf));
264 		xprt->address_strings[RPC_DISPLAY_ADDR] =
265 						kstrdup(buf, GFP_KERNEL);
266 		break;
267 	case AF_INET:
268 		(void)rpc_ntop(sap, buf, sizeof(buf));
269 		xprt->address_strings[RPC_DISPLAY_ADDR] =
270 						kstrdup(buf, GFP_KERNEL);
271 		sin = xs_addr_in(xprt);
272 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
273 		break;
274 	case AF_INET6:
275 		(void)rpc_ntop(sap, buf, sizeof(buf));
276 		xprt->address_strings[RPC_DISPLAY_ADDR] =
277 						kstrdup(buf, GFP_KERNEL);
278 		sin6 = xs_addr_in6(xprt);
279 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
280 		break;
281 	default:
282 		BUG();
283 	}
284 
285 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
286 }
287 
288 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
289 {
290 	struct sockaddr *sap = xs_addr(xprt);
291 	char buf[128];
292 
293 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
294 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
295 
296 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
297 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
298 }
299 
300 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
301 				     const char *protocol,
302 				     const char *netid)
303 {
304 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
305 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
306 	xs_format_common_peer_addresses(xprt);
307 	xs_format_common_peer_ports(xprt);
308 }
309 
310 static void xs_update_peer_port(struct rpc_xprt *xprt)
311 {
312 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
313 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
314 
315 	xs_format_common_peer_ports(xprt);
316 }
317 
318 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
319 {
320 	unsigned int i;
321 
322 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
323 		switch (i) {
324 		case RPC_DISPLAY_PROTO:
325 		case RPC_DISPLAY_NETID:
326 			continue;
327 		default:
328 			kfree(xprt->address_strings[i]);
329 		}
330 }
331 
332 static size_t
333 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
334 {
335 	size_t i,n;
336 
337 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
338 		return want;
339 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
340 	for (i = 0; i < n; i++) {
341 		if (buf->pages[i])
342 			continue;
343 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
344 		if (!buf->pages[i]) {
345 			i *= PAGE_SIZE;
346 			return i > buf->page_base ? i - buf->page_base : 0;
347 		}
348 	}
349 	return want;
350 }
351 
352 static ssize_t
353 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
354 {
355 	ssize_t ret;
356 	if (seek != 0)
357 		iov_iter_advance(&msg->msg_iter, seek);
358 	ret = sock_recvmsg(sock, msg, flags);
359 	return ret > 0 ? ret + seek : ret;
360 }
361 
362 static ssize_t
363 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
364 		struct kvec *kvec, size_t count, size_t seek)
365 {
366 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
367 	return xs_sock_recvmsg(sock, msg, flags, seek);
368 }
369 
370 static ssize_t
371 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
372 		struct bio_vec *bvec, unsigned long nr, size_t count,
373 		size_t seek)
374 {
375 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
376 	return xs_sock_recvmsg(sock, msg, flags, seek);
377 }
378 
379 static ssize_t
380 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
381 		size_t count)
382 {
383 	iov_iter_discard(&msg->msg_iter, READ, count);
384 	return sock_recvmsg(sock, msg, flags);
385 }
386 
387 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
388 static void
389 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
390 {
391 	struct bvec_iter bi = {
392 		.bi_size = count,
393 	};
394 	struct bio_vec bv;
395 
396 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
397 	for_each_bvec(bv, bvec, bi, bi)
398 		flush_dcache_page(bv.bv_page);
399 }
400 #else
401 static inline void
402 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
403 {
404 }
405 #endif
406 
407 static ssize_t
408 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
409 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
410 {
411 	size_t want, seek_init = seek, offset = 0;
412 	ssize_t ret;
413 
414 	want = min_t(size_t, count, buf->head[0].iov_len);
415 	if (seek < want) {
416 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
417 		if (ret <= 0)
418 			goto sock_err;
419 		offset += ret;
420 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
421 			goto out;
422 		if (ret != want)
423 			goto out;
424 		seek = 0;
425 	} else {
426 		seek -= want;
427 		offset += want;
428 	}
429 
430 	want = xs_alloc_sparse_pages(buf,
431 			min_t(size_t, count - offset, buf->page_len),
432 			GFP_KERNEL);
433 	if (seek < want) {
434 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
435 				xdr_buf_pagecount(buf),
436 				want + buf->page_base,
437 				seek + buf->page_base);
438 		if (ret <= 0)
439 			goto sock_err;
440 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
441 		ret -= buf->page_base;
442 		offset += ret;
443 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
444 			goto out;
445 		if (ret != want)
446 			goto out;
447 		seek = 0;
448 	} else {
449 		seek -= want;
450 		offset += want;
451 	}
452 
453 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
454 	if (seek < want) {
455 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
456 		if (ret <= 0)
457 			goto sock_err;
458 		offset += ret;
459 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
460 			goto out;
461 		if (ret != want)
462 			goto out;
463 	} else if (offset < seek_init)
464 		offset = seek_init;
465 	ret = -EMSGSIZE;
466 out:
467 	*read = offset - seek_init;
468 	return ret;
469 sock_err:
470 	offset += seek;
471 	goto out;
472 }
473 
474 static void
475 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
476 {
477 	if (!transport->recv.copied) {
478 		if (buf->head[0].iov_len >= transport->recv.offset)
479 			memcpy(buf->head[0].iov_base,
480 					&transport->recv.xid,
481 					transport->recv.offset);
482 		transport->recv.copied = transport->recv.offset;
483 	}
484 }
485 
486 static bool
487 xs_read_stream_request_done(struct sock_xprt *transport)
488 {
489 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
490 }
491 
492 static void
493 xs_read_stream_check_eor(struct sock_xprt *transport,
494 		struct msghdr *msg)
495 {
496 	if (xs_read_stream_request_done(transport))
497 		msg->msg_flags |= MSG_EOR;
498 }
499 
500 static ssize_t
501 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
502 		int flags, struct rpc_rqst *req)
503 {
504 	struct xdr_buf *buf = &req->rq_private_buf;
505 	size_t want, read;
506 	ssize_t ret;
507 
508 	xs_read_header(transport, buf);
509 
510 	want = transport->recv.len - transport->recv.offset;
511 	if (want != 0) {
512 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
513 				transport->recv.copied + want,
514 				transport->recv.copied,
515 				&read);
516 		transport->recv.offset += read;
517 		transport->recv.copied += read;
518 	}
519 
520 	if (transport->recv.offset == transport->recv.len)
521 		xs_read_stream_check_eor(transport, msg);
522 
523 	if (want == 0)
524 		return 0;
525 
526 	switch (ret) {
527 	default:
528 		break;
529 	case -EFAULT:
530 	case -EMSGSIZE:
531 		msg->msg_flags |= MSG_TRUNC;
532 		return read;
533 	case 0:
534 		return -ESHUTDOWN;
535 	}
536 	return ret < 0 ? ret : read;
537 }
538 
539 static size_t
540 xs_read_stream_headersize(bool isfrag)
541 {
542 	if (isfrag)
543 		return sizeof(__be32);
544 	return 3 * sizeof(__be32);
545 }
546 
547 static ssize_t
548 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
549 		int flags, size_t want, size_t seek)
550 {
551 	struct kvec kvec = {
552 		.iov_base = &transport->recv.fraghdr,
553 		.iov_len = want,
554 	};
555 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
556 }
557 
558 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
559 static ssize_t
560 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
561 {
562 	struct rpc_xprt *xprt = &transport->xprt;
563 	struct rpc_rqst *req;
564 	ssize_t ret;
565 
566 	/* Is this transport associated with the backchannel? */
567 	if (!xprt->bc_serv)
568 		return -ESHUTDOWN;
569 
570 	/* Look up and lock the request corresponding to the given XID */
571 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
572 	if (!req) {
573 		printk(KERN_WARNING "Callback slot table overflowed\n");
574 		return -ESHUTDOWN;
575 	}
576 	if (transport->recv.copied && !req->rq_private_buf.len)
577 		return -ESHUTDOWN;
578 
579 	ret = xs_read_stream_request(transport, msg, flags, req);
580 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
581 		xprt_complete_bc_request(req, transport->recv.copied);
582 	else
583 		req->rq_private_buf.len = transport->recv.copied;
584 
585 	return ret;
586 }
587 #else /* CONFIG_SUNRPC_BACKCHANNEL */
588 static ssize_t
589 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
590 {
591 	return -ESHUTDOWN;
592 }
593 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
594 
595 static ssize_t
596 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
597 {
598 	struct rpc_xprt *xprt = &transport->xprt;
599 	struct rpc_rqst *req;
600 	ssize_t ret = 0;
601 
602 	/* Look up and lock the request corresponding to the given XID */
603 	spin_lock(&xprt->queue_lock);
604 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
605 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
606 		msg->msg_flags |= MSG_TRUNC;
607 		goto out;
608 	}
609 	xprt_pin_rqst(req);
610 	spin_unlock(&xprt->queue_lock);
611 
612 	ret = xs_read_stream_request(transport, msg, flags, req);
613 
614 	spin_lock(&xprt->queue_lock);
615 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
616 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
617 	else
618 		req->rq_private_buf.len = transport->recv.copied;
619 	xprt_unpin_rqst(req);
620 out:
621 	spin_unlock(&xprt->queue_lock);
622 	return ret;
623 }
624 
625 static ssize_t
626 xs_read_stream(struct sock_xprt *transport, int flags)
627 {
628 	struct msghdr msg = { 0 };
629 	size_t want, read = 0;
630 	ssize_t ret = 0;
631 
632 	if (transport->recv.len == 0) {
633 		want = xs_read_stream_headersize(transport->recv.copied != 0);
634 		ret = xs_read_stream_header(transport, &msg, flags, want,
635 				transport->recv.offset);
636 		if (ret <= 0)
637 			goto out_err;
638 		transport->recv.offset = ret;
639 		if (transport->recv.offset != want)
640 			return transport->recv.offset;
641 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
642 			RPC_FRAGMENT_SIZE_MASK;
643 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
644 		read = ret;
645 	}
646 
647 	switch (be32_to_cpu(transport->recv.calldir)) {
648 	default:
649 		msg.msg_flags |= MSG_TRUNC;
650 		break;
651 	case RPC_CALL:
652 		ret = xs_read_stream_call(transport, &msg, flags);
653 		break;
654 	case RPC_REPLY:
655 		ret = xs_read_stream_reply(transport, &msg, flags);
656 	}
657 	if (msg.msg_flags & MSG_TRUNC) {
658 		transport->recv.calldir = cpu_to_be32(-1);
659 		transport->recv.copied = -1;
660 	}
661 	if (ret < 0)
662 		goto out_err;
663 	read += ret;
664 	if (transport->recv.offset < transport->recv.len) {
665 		if (!(msg.msg_flags & MSG_TRUNC))
666 			return read;
667 		msg.msg_flags = 0;
668 		ret = xs_read_discard(transport->sock, &msg, flags,
669 				transport->recv.len - transport->recv.offset);
670 		if (ret <= 0)
671 			goto out_err;
672 		transport->recv.offset += ret;
673 		read += ret;
674 		if (transport->recv.offset != transport->recv.len)
675 			return read;
676 	}
677 	if (xs_read_stream_request_done(transport)) {
678 		trace_xs_stream_read_request(transport);
679 		transport->recv.copied = 0;
680 	}
681 	transport->recv.offset = 0;
682 	transport->recv.len = 0;
683 	return read;
684 out_err:
685 	return ret != 0 ? ret : -ESHUTDOWN;
686 }
687 
688 static __poll_t xs_poll_socket(struct sock_xprt *transport)
689 {
690 	return transport->sock->ops->poll(transport->file, transport->sock,
691 			NULL);
692 }
693 
694 static bool xs_poll_socket_readable(struct sock_xprt *transport)
695 {
696 	__poll_t events = xs_poll_socket(transport);
697 
698 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
699 }
700 
701 static void xs_poll_check_readable(struct sock_xprt *transport)
702 {
703 
704 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
705 	if (!xs_poll_socket_readable(transport))
706 		return;
707 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
708 		queue_work(xprtiod_workqueue, &transport->recv_worker);
709 }
710 
711 static void xs_stream_data_receive(struct sock_xprt *transport)
712 {
713 	size_t read = 0;
714 	ssize_t ret = 0;
715 
716 	mutex_lock(&transport->recv_mutex);
717 	if (transport->sock == NULL)
718 		goto out;
719 	for (;;) {
720 		ret = xs_read_stream(transport, MSG_DONTWAIT);
721 		if (ret < 0)
722 			break;
723 		read += ret;
724 		cond_resched();
725 	}
726 	if (ret == -ESHUTDOWN)
727 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
728 	else
729 		xs_poll_check_readable(transport);
730 out:
731 	mutex_unlock(&transport->recv_mutex);
732 	trace_xs_stream_read_data(&transport->xprt, ret, read);
733 }
734 
735 static void xs_stream_data_receive_workfn(struct work_struct *work)
736 {
737 	struct sock_xprt *transport =
738 		container_of(work, struct sock_xprt, recv_worker);
739 	unsigned int pflags = memalloc_nofs_save();
740 
741 	xs_stream_data_receive(transport);
742 	memalloc_nofs_restore(pflags);
743 }
744 
745 static void
746 xs_stream_reset_connect(struct sock_xprt *transport)
747 {
748 	transport->recv.offset = 0;
749 	transport->recv.len = 0;
750 	transport->recv.copied = 0;
751 	transport->xmit.offset = 0;
752 }
753 
754 static void
755 xs_stream_start_connect(struct sock_xprt *transport)
756 {
757 	transport->xprt.stat.connect_count++;
758 	transport->xprt.stat.connect_start = jiffies;
759 }
760 
761 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
762 
763 /**
764  * xs_nospace - handle transmit was incomplete
765  * @req: pointer to RPC request
766  *
767  */
768 static int xs_nospace(struct rpc_rqst *req)
769 {
770 	struct rpc_xprt *xprt = req->rq_xprt;
771 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
772 	struct sock *sk = transport->inet;
773 	int ret = -EAGAIN;
774 
775 	trace_rpc_socket_nospace(req, transport);
776 
777 	/* Protect against races with write_space */
778 	spin_lock(&xprt->transport_lock);
779 
780 	/* Don't race with disconnect */
781 	if (xprt_connected(xprt)) {
782 		/* wait for more buffer space */
783 		sk->sk_write_pending++;
784 		xprt_wait_for_buffer_space(xprt);
785 	} else
786 		ret = -ENOTCONN;
787 
788 	spin_unlock(&xprt->transport_lock);
789 
790 	/* Race breaker in case memory is freed before above code is called */
791 	if (ret == -EAGAIN) {
792 		struct socket_wq *wq;
793 
794 		rcu_read_lock();
795 		wq = rcu_dereference(sk->sk_wq);
796 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
797 		rcu_read_unlock();
798 
799 		sk->sk_write_space(sk);
800 	}
801 	return ret;
802 }
803 
804 static void
805 xs_stream_prepare_request(struct rpc_rqst *req)
806 {
807 	xdr_free_bvec(&req->rq_rcv_buf);
808 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
809 }
810 
811 /*
812  * Determine if the previous message in the stream was aborted before it
813  * could complete transmission.
814  */
815 static bool
816 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
817 {
818 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
819 }
820 
821 /*
822  * Return the stream record marker field for a record of length < 2^31-1
823  */
824 static rpc_fraghdr
825 xs_stream_record_marker(struct xdr_buf *xdr)
826 {
827 	if (!xdr->len)
828 		return 0;
829 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
830 }
831 
832 /**
833  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
834  * @req: pointer to RPC request
835  *
836  * Return values:
837  *        0:	The request has been sent
838  *   EAGAIN:	The socket was blocked, please call again later to
839  *		complete the request
840  * ENOTCONN:	Caller needs to invoke connect logic then call again
841  *    other:	Some other error occurred, the request was not sent
842  */
843 static int xs_local_send_request(struct rpc_rqst *req)
844 {
845 	struct rpc_xprt *xprt = req->rq_xprt;
846 	struct sock_xprt *transport =
847 				container_of(xprt, struct sock_xprt, xprt);
848 	struct xdr_buf *xdr = &req->rq_snd_buf;
849 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
850 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
851 	struct msghdr msg = {
852 		.msg_flags	= XS_SENDMSG_FLAGS,
853 	};
854 	unsigned int sent;
855 	int status;
856 
857 	/* Close the stream if the previous transmission was incomplete */
858 	if (xs_send_request_was_aborted(transport, req)) {
859 		xs_close(xprt);
860 		return -ENOTCONN;
861 	}
862 
863 	xs_pktdump("packet data:",
864 			req->rq_svec->iov_base, req->rq_svec->iov_len);
865 
866 	req->rq_xtime = ktime_get();
867 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
868 				   transport->xmit.offset, rm, &sent);
869 	dprintk("RPC:       %s(%u) = %d\n",
870 			__func__, xdr->len - transport->xmit.offset, status);
871 
872 	if (status == -EAGAIN && sock_writeable(transport->inet))
873 		status = -ENOBUFS;
874 
875 	if (likely(sent > 0) || status == 0) {
876 		transport->xmit.offset += sent;
877 		req->rq_bytes_sent = transport->xmit.offset;
878 		if (likely(req->rq_bytes_sent >= msglen)) {
879 			req->rq_xmit_bytes_sent += transport->xmit.offset;
880 			transport->xmit.offset = 0;
881 			return 0;
882 		}
883 		status = -EAGAIN;
884 	}
885 
886 	switch (status) {
887 	case -ENOBUFS:
888 		break;
889 	case -EAGAIN:
890 		status = xs_nospace(req);
891 		break;
892 	default:
893 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
894 			-status);
895 		fallthrough;
896 	case -EPIPE:
897 		xs_close(xprt);
898 		status = -ENOTCONN;
899 	}
900 
901 	return status;
902 }
903 
904 /**
905  * xs_udp_send_request - write an RPC request to a UDP socket
906  * @req: pointer to RPC request
907  *
908  * Return values:
909  *        0:	The request has been sent
910  *   EAGAIN:	The socket was blocked, please call again later to
911  *		complete the request
912  * ENOTCONN:	Caller needs to invoke connect logic then call again
913  *    other:	Some other error occurred, the request was not sent
914  */
915 static int xs_udp_send_request(struct rpc_rqst *req)
916 {
917 	struct rpc_xprt *xprt = req->rq_xprt;
918 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
919 	struct xdr_buf *xdr = &req->rq_snd_buf;
920 	struct msghdr msg = {
921 		.msg_name	= xs_addr(xprt),
922 		.msg_namelen	= xprt->addrlen,
923 		.msg_flags	= XS_SENDMSG_FLAGS,
924 	};
925 	unsigned int sent;
926 	int status;
927 
928 	xs_pktdump("packet data:",
929 				req->rq_svec->iov_base,
930 				req->rq_svec->iov_len);
931 
932 	if (!xprt_bound(xprt))
933 		return -ENOTCONN;
934 
935 	if (!xprt_request_get_cong(xprt, req))
936 		return -EBADSLT;
937 
938 	req->rq_xtime = ktime_get();
939 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
940 
941 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
942 			xdr->len, status);
943 
944 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
945 	if (status == -EPERM)
946 		goto process_status;
947 
948 	if (status == -EAGAIN && sock_writeable(transport->inet))
949 		status = -ENOBUFS;
950 
951 	if (sent > 0 || status == 0) {
952 		req->rq_xmit_bytes_sent += sent;
953 		if (sent >= req->rq_slen)
954 			return 0;
955 		/* Still some bytes left; set up for a retry later. */
956 		status = -EAGAIN;
957 	}
958 
959 process_status:
960 	switch (status) {
961 	case -ENOTSOCK:
962 		status = -ENOTCONN;
963 		/* Should we call xs_close() here? */
964 		break;
965 	case -EAGAIN:
966 		status = xs_nospace(req);
967 		break;
968 	case -ENETUNREACH:
969 	case -ENOBUFS:
970 	case -EPIPE:
971 	case -ECONNREFUSED:
972 	case -EPERM:
973 		/* When the server has died, an ICMP port unreachable message
974 		 * prompts ECONNREFUSED. */
975 		break;
976 	default:
977 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
978 			-status);
979 	}
980 
981 	return status;
982 }
983 
984 /**
985  * xs_tcp_send_request - write an RPC request to a TCP socket
986  * @req: pointer to RPC request
987  *
988  * Return values:
989  *        0:	The request has been sent
990  *   EAGAIN:	The socket was blocked, please call again later to
991  *		complete the request
992  * ENOTCONN:	Caller needs to invoke connect logic then call again
993  *    other:	Some other error occurred, the request was not sent
994  *
995  * XXX: In the case of soft timeouts, should we eventually give up
996  *	if sendmsg is not able to make progress?
997  */
998 static int xs_tcp_send_request(struct rpc_rqst *req)
999 {
1000 	struct rpc_xprt *xprt = req->rq_xprt;
1001 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1002 	struct xdr_buf *xdr = &req->rq_snd_buf;
1003 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
1004 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1005 	struct msghdr msg = {
1006 		.msg_flags	= XS_SENDMSG_FLAGS,
1007 	};
1008 	bool vm_wait = false;
1009 	unsigned int sent;
1010 	int status;
1011 
1012 	/* Close the stream if the previous transmission was incomplete */
1013 	if (xs_send_request_was_aborted(transport, req)) {
1014 		if (transport->sock != NULL)
1015 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1016 		return -ENOTCONN;
1017 	}
1018 	if (!transport->inet)
1019 		return -ENOTCONN;
1020 
1021 	xs_pktdump("packet data:",
1022 				req->rq_svec->iov_base,
1023 				req->rq_svec->iov_len);
1024 
1025 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1026 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1027 
1028 	/* Continue transmitting the packet/record. We must be careful
1029 	 * to cope with writespace callbacks arriving _after_ we have
1030 	 * called sendmsg(). */
1031 	req->rq_xtime = ktime_get();
1032 	tcp_sock_set_cork(transport->inet, true);
1033 	while (1) {
1034 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1035 					   transport->xmit.offset, rm, &sent);
1036 
1037 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1038 				xdr->len - transport->xmit.offset, status);
1039 
1040 		/* If we've sent the entire packet, immediately
1041 		 * reset the count of bytes sent. */
1042 		transport->xmit.offset += sent;
1043 		req->rq_bytes_sent = transport->xmit.offset;
1044 		if (likely(req->rq_bytes_sent >= msglen)) {
1045 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1046 			transport->xmit.offset = 0;
1047 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1048 				tcp_sock_set_cork(transport->inet, false);
1049 			return 0;
1050 		}
1051 
1052 		WARN_ON_ONCE(sent == 0 && status == 0);
1053 
1054 		if (status == -EAGAIN ) {
1055 			/*
1056 			 * Return EAGAIN if we're sure we're hitting the
1057 			 * socket send buffer limits.
1058 			 */
1059 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1060 				break;
1061 			/*
1062 			 * Did we hit a memory allocation failure?
1063 			 */
1064 			if (sent == 0) {
1065 				status = -ENOBUFS;
1066 				if (vm_wait)
1067 					break;
1068 				/* Retry, knowing now that we're below the
1069 				 * socket send buffer limit
1070 				 */
1071 				vm_wait = true;
1072 			}
1073 			continue;
1074 		}
1075 		if (status < 0)
1076 			break;
1077 		vm_wait = false;
1078 	}
1079 
1080 	switch (status) {
1081 	case -ENOTSOCK:
1082 		status = -ENOTCONN;
1083 		/* Should we call xs_close() here? */
1084 		break;
1085 	case -EAGAIN:
1086 		status = xs_nospace(req);
1087 		break;
1088 	case -ECONNRESET:
1089 	case -ECONNREFUSED:
1090 	case -ENOTCONN:
1091 	case -EADDRINUSE:
1092 	case -ENOBUFS:
1093 	case -EPIPE:
1094 		break;
1095 	default:
1096 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1097 			-status);
1098 	}
1099 
1100 	return status;
1101 }
1102 
1103 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1104 {
1105 	transport->old_data_ready = sk->sk_data_ready;
1106 	transport->old_state_change = sk->sk_state_change;
1107 	transport->old_write_space = sk->sk_write_space;
1108 	transport->old_error_report = sk->sk_error_report;
1109 }
1110 
1111 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1112 {
1113 	sk->sk_data_ready = transport->old_data_ready;
1114 	sk->sk_state_change = transport->old_state_change;
1115 	sk->sk_write_space = transport->old_write_space;
1116 	sk->sk_error_report = transport->old_error_report;
1117 }
1118 
1119 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1120 {
1121 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1122 
1123 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1124 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1125 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1126 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1127 }
1128 
1129 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1130 {
1131 	set_bit(nr, &transport->sock_state);
1132 	queue_work(xprtiod_workqueue, &transport->error_worker);
1133 }
1134 
1135 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1136 {
1137 	xprt->connect_cookie++;
1138 	smp_mb__before_atomic();
1139 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1140 	clear_bit(XPRT_CLOSING, &xprt->state);
1141 	xs_sock_reset_state_flags(xprt);
1142 	smp_mb__after_atomic();
1143 }
1144 
1145 /**
1146  * xs_error_report - callback to handle TCP socket state errors
1147  * @sk: socket
1148  *
1149  * Note: we don't call sock_error() since there may be a rpc_task
1150  * using the socket, and so we don't want to clear sk->sk_err.
1151  */
1152 static void xs_error_report(struct sock *sk)
1153 {
1154 	struct sock_xprt *transport;
1155 	struct rpc_xprt *xprt;
1156 
1157 	if (!(xprt = xprt_from_sock(sk)))
1158 		return;
1159 
1160 	transport = container_of(xprt, struct sock_xprt, xprt);
1161 	transport->xprt_err = -sk->sk_err;
1162 	if (transport->xprt_err == 0)
1163 		return;
1164 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1165 			xprt, -transport->xprt_err);
1166 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1167 
1168 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1169 	smp_mb__before_atomic();
1170 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1171 }
1172 
1173 static void xs_reset_transport(struct sock_xprt *transport)
1174 {
1175 	struct socket *sock = transport->sock;
1176 	struct sock *sk = transport->inet;
1177 	struct rpc_xprt *xprt = &transport->xprt;
1178 	struct file *filp = transport->file;
1179 
1180 	if (sk == NULL)
1181 		return;
1182 
1183 	if (atomic_read(&transport->xprt.swapper))
1184 		sk_clear_memalloc(sk);
1185 
1186 	kernel_sock_shutdown(sock, SHUT_RDWR);
1187 
1188 	mutex_lock(&transport->recv_mutex);
1189 	lock_sock(sk);
1190 	transport->inet = NULL;
1191 	transport->sock = NULL;
1192 	transport->file = NULL;
1193 
1194 	sk->sk_user_data = NULL;
1195 
1196 	xs_restore_old_callbacks(transport, sk);
1197 	xprt_clear_connected(xprt);
1198 	xs_sock_reset_connection_flags(xprt);
1199 	/* Reset stream record info */
1200 	xs_stream_reset_connect(transport);
1201 	release_sock(sk);
1202 	mutex_unlock(&transport->recv_mutex);
1203 
1204 	trace_rpc_socket_close(xprt, sock);
1205 	fput(filp);
1206 
1207 	xprt_disconnect_done(xprt);
1208 }
1209 
1210 /**
1211  * xs_close - close a socket
1212  * @xprt: transport
1213  *
1214  * This is used when all requests are complete; ie, no DRC state remains
1215  * on the server we want to save.
1216  *
1217  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1218  * xs_reset_transport() zeroing the socket from underneath a writer.
1219  */
1220 static void xs_close(struct rpc_xprt *xprt)
1221 {
1222 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1223 
1224 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1225 
1226 	xs_reset_transport(transport);
1227 	xprt->reestablish_timeout = 0;
1228 }
1229 
1230 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1231 {
1232 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1233 		xprt);
1234 	xprt_disconnect_done(xprt);
1235 }
1236 
1237 static void xs_xprt_free(struct rpc_xprt *xprt)
1238 {
1239 	xs_free_peer_addresses(xprt);
1240 	xprt_free(xprt);
1241 }
1242 
1243 /**
1244  * xs_destroy - prepare to shutdown a transport
1245  * @xprt: doomed transport
1246  *
1247  */
1248 static void xs_destroy(struct rpc_xprt *xprt)
1249 {
1250 	struct sock_xprt *transport = container_of(xprt,
1251 			struct sock_xprt, xprt);
1252 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1253 
1254 	cancel_delayed_work_sync(&transport->connect_worker);
1255 	xs_close(xprt);
1256 	cancel_work_sync(&transport->recv_worker);
1257 	cancel_work_sync(&transport->error_worker);
1258 	xs_xprt_free(xprt);
1259 	module_put(THIS_MODULE);
1260 }
1261 
1262 /**
1263  * xs_udp_data_read_skb - receive callback for UDP sockets
1264  * @xprt: transport
1265  * @sk: socket
1266  * @skb: skbuff
1267  *
1268  */
1269 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1270 		struct sock *sk,
1271 		struct sk_buff *skb)
1272 {
1273 	struct rpc_task *task;
1274 	struct rpc_rqst *rovr;
1275 	int repsize, copied;
1276 	u32 _xid;
1277 	__be32 *xp;
1278 
1279 	repsize = skb->len;
1280 	if (repsize < 4) {
1281 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1282 		return;
1283 	}
1284 
1285 	/* Copy the XID from the skb... */
1286 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1287 	if (xp == NULL)
1288 		return;
1289 
1290 	/* Look up and lock the request corresponding to the given XID */
1291 	spin_lock(&xprt->queue_lock);
1292 	rovr = xprt_lookup_rqst(xprt, *xp);
1293 	if (!rovr)
1294 		goto out_unlock;
1295 	xprt_pin_rqst(rovr);
1296 	xprt_update_rtt(rovr->rq_task);
1297 	spin_unlock(&xprt->queue_lock);
1298 	task = rovr->rq_task;
1299 
1300 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1301 		copied = repsize;
1302 
1303 	/* Suck it into the iovec, verify checksum if not done by hw. */
1304 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1305 		spin_lock(&xprt->queue_lock);
1306 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1307 		goto out_unpin;
1308 	}
1309 
1310 
1311 	spin_lock(&xprt->transport_lock);
1312 	xprt_adjust_cwnd(xprt, task, copied);
1313 	spin_unlock(&xprt->transport_lock);
1314 	spin_lock(&xprt->queue_lock);
1315 	xprt_complete_rqst(task, copied);
1316 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1317 out_unpin:
1318 	xprt_unpin_rqst(rovr);
1319  out_unlock:
1320 	spin_unlock(&xprt->queue_lock);
1321 }
1322 
1323 static void xs_udp_data_receive(struct sock_xprt *transport)
1324 {
1325 	struct sk_buff *skb;
1326 	struct sock *sk;
1327 	int err;
1328 
1329 	mutex_lock(&transport->recv_mutex);
1330 	sk = transport->inet;
1331 	if (sk == NULL)
1332 		goto out;
1333 	for (;;) {
1334 		skb = skb_recv_udp(sk, 0, 1, &err);
1335 		if (skb == NULL)
1336 			break;
1337 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1338 		consume_skb(skb);
1339 		cond_resched();
1340 	}
1341 	xs_poll_check_readable(transport);
1342 out:
1343 	mutex_unlock(&transport->recv_mutex);
1344 }
1345 
1346 static void xs_udp_data_receive_workfn(struct work_struct *work)
1347 {
1348 	struct sock_xprt *transport =
1349 		container_of(work, struct sock_xprt, recv_worker);
1350 	unsigned int pflags = memalloc_nofs_save();
1351 
1352 	xs_udp_data_receive(transport);
1353 	memalloc_nofs_restore(pflags);
1354 }
1355 
1356 /**
1357  * xs_data_ready - "data ready" callback for UDP sockets
1358  * @sk: socket with data to read
1359  *
1360  */
1361 static void xs_data_ready(struct sock *sk)
1362 {
1363 	struct rpc_xprt *xprt;
1364 
1365 	dprintk("RPC:       xs_data_ready...\n");
1366 	xprt = xprt_from_sock(sk);
1367 	if (xprt != NULL) {
1368 		struct sock_xprt *transport = container_of(xprt,
1369 				struct sock_xprt, xprt);
1370 		transport->old_data_ready(sk);
1371 		/* Any data means we had a useful conversation, so
1372 		 * then we don't need to delay the next reconnect
1373 		 */
1374 		if (xprt->reestablish_timeout)
1375 			xprt->reestablish_timeout = 0;
1376 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1377 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1378 	}
1379 }
1380 
1381 /*
1382  * Helper function to force a TCP close if the server is sending
1383  * junk and/or it has put us in CLOSE_WAIT
1384  */
1385 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1386 {
1387 	xprt_force_disconnect(xprt);
1388 }
1389 
1390 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1391 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1392 {
1393 	return PAGE_SIZE;
1394 }
1395 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1396 
1397 /**
1398  * xs_tcp_state_change - callback to handle TCP socket state changes
1399  * @sk: socket whose state has changed
1400  *
1401  */
1402 static void xs_tcp_state_change(struct sock *sk)
1403 {
1404 	struct rpc_xprt *xprt;
1405 	struct sock_xprt *transport;
1406 
1407 	if (!(xprt = xprt_from_sock(sk)))
1408 		return;
1409 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1410 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1411 			sk->sk_state, xprt_connected(xprt),
1412 			sock_flag(sk, SOCK_DEAD),
1413 			sock_flag(sk, SOCK_ZAPPED),
1414 			sk->sk_shutdown);
1415 
1416 	transport = container_of(xprt, struct sock_xprt, xprt);
1417 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1418 	switch (sk->sk_state) {
1419 	case TCP_ESTABLISHED:
1420 		if (!xprt_test_and_set_connected(xprt)) {
1421 			xprt->connect_cookie++;
1422 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1423 			xprt_clear_connecting(xprt);
1424 
1425 			xprt->stat.connect_count++;
1426 			xprt->stat.connect_time += (long)jiffies -
1427 						   xprt->stat.connect_start;
1428 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1429 		}
1430 		break;
1431 	case TCP_FIN_WAIT1:
1432 		/* The client initiated a shutdown of the socket */
1433 		xprt->connect_cookie++;
1434 		xprt->reestablish_timeout = 0;
1435 		set_bit(XPRT_CLOSING, &xprt->state);
1436 		smp_mb__before_atomic();
1437 		clear_bit(XPRT_CONNECTED, &xprt->state);
1438 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1439 		smp_mb__after_atomic();
1440 		break;
1441 	case TCP_CLOSE_WAIT:
1442 		/* The server initiated a shutdown of the socket */
1443 		xprt->connect_cookie++;
1444 		clear_bit(XPRT_CONNECTED, &xprt->state);
1445 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1446 		fallthrough;
1447 	case TCP_CLOSING:
1448 		/*
1449 		 * If the server closed down the connection, make sure that
1450 		 * we back off before reconnecting
1451 		 */
1452 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1453 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1454 		break;
1455 	case TCP_LAST_ACK:
1456 		set_bit(XPRT_CLOSING, &xprt->state);
1457 		smp_mb__before_atomic();
1458 		clear_bit(XPRT_CONNECTED, &xprt->state);
1459 		smp_mb__after_atomic();
1460 		break;
1461 	case TCP_CLOSE:
1462 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1463 					&transport->sock_state))
1464 			xprt_clear_connecting(xprt);
1465 		clear_bit(XPRT_CLOSING, &xprt->state);
1466 		/* Trigger the socket release */
1467 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1468 	}
1469 }
1470 
1471 static void xs_write_space(struct sock *sk)
1472 {
1473 	struct socket_wq *wq;
1474 	struct sock_xprt *transport;
1475 	struct rpc_xprt *xprt;
1476 
1477 	if (!sk->sk_socket)
1478 		return;
1479 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1480 
1481 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1482 		return;
1483 	transport = container_of(xprt, struct sock_xprt, xprt);
1484 	rcu_read_lock();
1485 	wq = rcu_dereference(sk->sk_wq);
1486 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1487 		goto out;
1488 
1489 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1490 	sk->sk_write_pending--;
1491 out:
1492 	rcu_read_unlock();
1493 }
1494 
1495 /**
1496  * xs_udp_write_space - callback invoked when socket buffer space
1497  *                             becomes available
1498  * @sk: socket whose state has changed
1499  *
1500  * Called when more output buffer space is available for this socket.
1501  * We try not to wake our writers until they can make "significant"
1502  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1503  * with a bunch of small requests.
1504  */
1505 static void xs_udp_write_space(struct sock *sk)
1506 {
1507 	/* from net/core/sock.c:sock_def_write_space */
1508 	if (sock_writeable(sk))
1509 		xs_write_space(sk);
1510 }
1511 
1512 /**
1513  * xs_tcp_write_space - callback invoked when socket buffer space
1514  *                             becomes available
1515  * @sk: socket whose state has changed
1516  *
1517  * Called when more output buffer space is available for this socket.
1518  * We try not to wake our writers until they can make "significant"
1519  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1520  * with a bunch of small requests.
1521  */
1522 static void xs_tcp_write_space(struct sock *sk)
1523 {
1524 	/* from net/core/stream.c:sk_stream_write_space */
1525 	if (sk_stream_is_writeable(sk))
1526 		xs_write_space(sk);
1527 }
1528 
1529 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1530 {
1531 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1532 	struct sock *sk = transport->inet;
1533 
1534 	if (transport->rcvsize) {
1535 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1536 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1537 	}
1538 	if (transport->sndsize) {
1539 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1540 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1541 		sk->sk_write_space(sk);
1542 	}
1543 }
1544 
1545 /**
1546  * xs_udp_set_buffer_size - set send and receive limits
1547  * @xprt: generic transport
1548  * @sndsize: requested size of send buffer, in bytes
1549  * @rcvsize: requested size of receive buffer, in bytes
1550  *
1551  * Set socket send and receive buffer size limits.
1552  */
1553 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1554 {
1555 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1556 
1557 	transport->sndsize = 0;
1558 	if (sndsize)
1559 		transport->sndsize = sndsize + 1024;
1560 	transport->rcvsize = 0;
1561 	if (rcvsize)
1562 		transport->rcvsize = rcvsize + 1024;
1563 
1564 	xs_udp_do_set_buffer_size(xprt);
1565 }
1566 
1567 /**
1568  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1569  * @xprt: controlling transport
1570  * @task: task that timed out
1571  *
1572  * Adjust the congestion window after a retransmit timeout has occurred.
1573  */
1574 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1575 {
1576 	spin_lock(&xprt->transport_lock);
1577 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1578 	spin_unlock(&xprt->transport_lock);
1579 }
1580 
1581 static int xs_get_random_port(void)
1582 {
1583 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1584 	unsigned short range;
1585 	unsigned short rand;
1586 
1587 	if (max < min)
1588 		return -EADDRINUSE;
1589 	range = max - min + 1;
1590 	rand = (unsigned short) prandom_u32() % range;
1591 	return rand + min;
1592 }
1593 
1594 static unsigned short xs_sock_getport(struct socket *sock)
1595 {
1596 	struct sockaddr_storage buf;
1597 	unsigned short port = 0;
1598 
1599 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1600 		goto out;
1601 	switch (buf.ss_family) {
1602 	case AF_INET6:
1603 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1604 		break;
1605 	case AF_INET:
1606 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1607 	}
1608 out:
1609 	return port;
1610 }
1611 
1612 /**
1613  * xs_set_port - reset the port number in the remote endpoint address
1614  * @xprt: generic transport
1615  * @port: new port number
1616  *
1617  */
1618 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1619 {
1620 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1621 
1622 	rpc_set_port(xs_addr(xprt), port);
1623 	xs_update_peer_port(xprt);
1624 }
1625 
1626 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1627 {
1628 	if (transport->srcport == 0 && transport->xprt.reuseport)
1629 		transport->srcport = xs_sock_getport(sock);
1630 }
1631 
1632 static int xs_get_srcport(struct sock_xprt *transport)
1633 {
1634 	int port = transport->srcport;
1635 
1636 	if (port == 0 && transport->xprt.resvport)
1637 		port = xs_get_random_port();
1638 	return port;
1639 }
1640 
1641 unsigned short get_srcport(struct rpc_xprt *xprt)
1642 {
1643 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1644 	return xs_sock_getport(sock->sock);
1645 }
1646 EXPORT_SYMBOL(get_srcport);
1647 
1648 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1649 {
1650 	if (transport->srcport != 0)
1651 		transport->srcport = 0;
1652 	if (!transport->xprt.resvport)
1653 		return 0;
1654 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1655 		return xprt_max_resvport;
1656 	return --port;
1657 }
1658 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1659 {
1660 	struct sockaddr_storage myaddr;
1661 	int err, nloop = 0;
1662 	int port = xs_get_srcport(transport);
1663 	unsigned short last;
1664 
1665 	/*
1666 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1667 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1668 	 * port selection happen implicitly when the socket is used
1669 	 * (for example at connect time).
1670 	 *
1671 	 * This ensures that we can continue to establish TCP
1672 	 * connections even when all local ephemeral ports are already
1673 	 * a part of some TCP connection.  This makes no difference
1674 	 * for UDP sockets, but also doesn't harm them.
1675 	 *
1676 	 * If we're asking for any reserved port (i.e. port == 0 &&
1677 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1678 	 * ensure that port is non-zero and we will bind as needed.
1679 	 */
1680 	if (port <= 0)
1681 		return port;
1682 
1683 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1684 	do {
1685 		rpc_set_port((struct sockaddr *)&myaddr, port);
1686 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1687 				transport->xprt.addrlen);
1688 		if (err == 0) {
1689 			if (transport->xprt.reuseport)
1690 				transport->srcport = port;
1691 			break;
1692 		}
1693 		last = port;
1694 		port = xs_next_srcport(transport, port);
1695 		if (port > last)
1696 			nloop++;
1697 	} while (err == -EADDRINUSE && nloop != 2);
1698 
1699 	if (myaddr.ss_family == AF_INET)
1700 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1701 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1702 				port, err ? "failed" : "ok", err);
1703 	else
1704 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1705 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1706 				port, err ? "failed" : "ok", err);
1707 	return err;
1708 }
1709 
1710 /*
1711  * We don't support autobind on AF_LOCAL sockets
1712  */
1713 static void xs_local_rpcbind(struct rpc_task *task)
1714 {
1715 	xprt_set_bound(task->tk_xprt);
1716 }
1717 
1718 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1719 {
1720 }
1721 
1722 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1723 static struct lock_class_key xs_key[2];
1724 static struct lock_class_key xs_slock_key[2];
1725 
1726 static inline void xs_reclassify_socketu(struct socket *sock)
1727 {
1728 	struct sock *sk = sock->sk;
1729 
1730 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1731 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1732 }
1733 
1734 static inline void xs_reclassify_socket4(struct socket *sock)
1735 {
1736 	struct sock *sk = sock->sk;
1737 
1738 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1739 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1740 }
1741 
1742 static inline void xs_reclassify_socket6(struct socket *sock)
1743 {
1744 	struct sock *sk = sock->sk;
1745 
1746 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1747 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1748 }
1749 
1750 static inline void xs_reclassify_socket(int family, struct socket *sock)
1751 {
1752 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1753 		return;
1754 
1755 	switch (family) {
1756 	case AF_LOCAL:
1757 		xs_reclassify_socketu(sock);
1758 		break;
1759 	case AF_INET:
1760 		xs_reclassify_socket4(sock);
1761 		break;
1762 	case AF_INET6:
1763 		xs_reclassify_socket6(sock);
1764 		break;
1765 	}
1766 }
1767 #else
1768 static inline void xs_reclassify_socket(int family, struct socket *sock)
1769 {
1770 }
1771 #endif
1772 
1773 static void xs_dummy_setup_socket(struct work_struct *work)
1774 {
1775 }
1776 
1777 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1778 		struct sock_xprt *transport, int family, int type,
1779 		int protocol, bool reuseport)
1780 {
1781 	struct file *filp;
1782 	struct socket *sock;
1783 	int err;
1784 
1785 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1786 	if (err < 0) {
1787 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1788 				protocol, -err);
1789 		goto out;
1790 	}
1791 	xs_reclassify_socket(family, sock);
1792 
1793 	if (reuseport)
1794 		sock_set_reuseport(sock->sk);
1795 
1796 	err = xs_bind(transport, sock);
1797 	if (err) {
1798 		sock_release(sock);
1799 		goto out;
1800 	}
1801 
1802 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1803 	if (IS_ERR(filp))
1804 		return ERR_CAST(filp);
1805 	transport->file = filp;
1806 
1807 	return sock;
1808 out:
1809 	return ERR_PTR(err);
1810 }
1811 
1812 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1813 				      struct socket *sock)
1814 {
1815 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1816 									xprt);
1817 
1818 	if (!transport->inet) {
1819 		struct sock *sk = sock->sk;
1820 
1821 		lock_sock(sk);
1822 
1823 		xs_save_old_callbacks(transport, sk);
1824 
1825 		sk->sk_user_data = xprt;
1826 		sk->sk_data_ready = xs_data_ready;
1827 		sk->sk_write_space = xs_udp_write_space;
1828 		sock_set_flag(sk, SOCK_FASYNC);
1829 		sk->sk_error_report = xs_error_report;
1830 
1831 		xprt_clear_connected(xprt);
1832 
1833 		/* Reset to new socket */
1834 		transport->sock = sock;
1835 		transport->inet = sk;
1836 
1837 		release_sock(sk);
1838 	}
1839 
1840 	xs_stream_start_connect(transport);
1841 
1842 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1843 }
1844 
1845 /**
1846  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1847  * @transport: socket transport to connect
1848  */
1849 static int xs_local_setup_socket(struct sock_xprt *transport)
1850 {
1851 	struct rpc_xprt *xprt = &transport->xprt;
1852 	struct file *filp;
1853 	struct socket *sock;
1854 	int status;
1855 
1856 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1857 					SOCK_STREAM, 0, &sock, 1);
1858 	if (status < 0) {
1859 		dprintk("RPC:       can't create AF_LOCAL "
1860 			"transport socket (%d).\n", -status);
1861 		goto out;
1862 	}
1863 	xs_reclassify_socket(AF_LOCAL, sock);
1864 
1865 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1866 	if (IS_ERR(filp)) {
1867 		status = PTR_ERR(filp);
1868 		goto out;
1869 	}
1870 	transport->file = filp;
1871 
1872 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1873 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1874 
1875 	status = xs_local_finish_connecting(xprt, sock);
1876 	trace_rpc_socket_connect(xprt, sock, status);
1877 	switch (status) {
1878 	case 0:
1879 		dprintk("RPC:       xprt %p connected to %s\n",
1880 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1881 		xprt->stat.connect_count++;
1882 		xprt->stat.connect_time += (long)jiffies -
1883 					   xprt->stat.connect_start;
1884 		xprt_set_connected(xprt);
1885 		break;
1886 	case -ENOBUFS:
1887 		break;
1888 	case -ENOENT:
1889 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1890 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1891 		break;
1892 	case -ECONNREFUSED:
1893 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1894 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1895 		break;
1896 	default:
1897 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1898 				__func__, -status,
1899 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1900 	}
1901 
1902 out:
1903 	xprt_clear_connecting(xprt);
1904 	xprt_wake_pending_tasks(xprt, status);
1905 	return status;
1906 }
1907 
1908 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1909 {
1910 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1911 	int ret;
1912 
1913 	 if (RPC_IS_ASYNC(task)) {
1914 		/*
1915 		 * We want the AF_LOCAL connect to be resolved in the
1916 		 * filesystem namespace of the process making the rpc
1917 		 * call.  Thus we connect synchronously.
1918 		 *
1919 		 * If we want to support asynchronous AF_LOCAL calls,
1920 		 * we'll need to figure out how to pass a namespace to
1921 		 * connect.
1922 		 */
1923 		task->tk_rpc_status = -ENOTCONN;
1924 		rpc_exit(task, -ENOTCONN);
1925 		return;
1926 	}
1927 	ret = xs_local_setup_socket(transport);
1928 	if (ret && !RPC_IS_SOFTCONN(task))
1929 		msleep_interruptible(15000);
1930 }
1931 
1932 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1933 /*
1934  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1935  * know that we have exclusive access to the socket), to guard against
1936  * races with xs_reset_transport.
1937  */
1938 static void xs_set_memalloc(struct rpc_xprt *xprt)
1939 {
1940 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1941 			xprt);
1942 
1943 	/*
1944 	 * If there's no sock, then we have nothing to set. The
1945 	 * reconnecting process will get it for us.
1946 	 */
1947 	if (!transport->inet)
1948 		return;
1949 	if (atomic_read(&xprt->swapper))
1950 		sk_set_memalloc(transport->inet);
1951 }
1952 
1953 /**
1954  * xs_enable_swap - Tag this transport as being used for swap.
1955  * @xprt: transport to tag
1956  *
1957  * Take a reference to this transport on behalf of the rpc_clnt, and
1958  * optionally mark it for swapping if it wasn't already.
1959  */
1960 static int
1961 xs_enable_swap(struct rpc_xprt *xprt)
1962 {
1963 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1964 
1965 	if (atomic_inc_return(&xprt->swapper) != 1)
1966 		return 0;
1967 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1968 		return -ERESTARTSYS;
1969 	if (xs->inet)
1970 		sk_set_memalloc(xs->inet);
1971 	xprt_release_xprt(xprt, NULL);
1972 	return 0;
1973 }
1974 
1975 /**
1976  * xs_disable_swap - Untag this transport as being used for swap.
1977  * @xprt: transport to tag
1978  *
1979  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1980  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1981  */
1982 static void
1983 xs_disable_swap(struct rpc_xprt *xprt)
1984 {
1985 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1986 
1987 	if (!atomic_dec_and_test(&xprt->swapper))
1988 		return;
1989 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1990 		return;
1991 	if (xs->inet)
1992 		sk_clear_memalloc(xs->inet);
1993 	xprt_release_xprt(xprt, NULL);
1994 }
1995 #else
1996 static void xs_set_memalloc(struct rpc_xprt *xprt)
1997 {
1998 }
1999 
2000 static int
2001 xs_enable_swap(struct rpc_xprt *xprt)
2002 {
2003 	return -EINVAL;
2004 }
2005 
2006 static void
2007 xs_disable_swap(struct rpc_xprt *xprt)
2008 {
2009 }
2010 #endif
2011 
2012 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2013 {
2014 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2015 
2016 	if (!transport->inet) {
2017 		struct sock *sk = sock->sk;
2018 
2019 		lock_sock(sk);
2020 
2021 		xs_save_old_callbacks(transport, sk);
2022 
2023 		sk->sk_user_data = xprt;
2024 		sk->sk_data_ready = xs_data_ready;
2025 		sk->sk_write_space = xs_udp_write_space;
2026 		sock_set_flag(sk, SOCK_FASYNC);
2027 
2028 		xprt_set_connected(xprt);
2029 
2030 		/* Reset to new socket */
2031 		transport->sock = sock;
2032 		transport->inet = sk;
2033 
2034 		xs_set_memalloc(xprt);
2035 
2036 		release_sock(sk);
2037 	}
2038 	xs_udp_do_set_buffer_size(xprt);
2039 
2040 	xprt->stat.connect_start = jiffies;
2041 }
2042 
2043 static void xs_udp_setup_socket(struct work_struct *work)
2044 {
2045 	struct sock_xprt *transport =
2046 		container_of(work, struct sock_xprt, connect_worker.work);
2047 	struct rpc_xprt *xprt = &transport->xprt;
2048 	struct socket *sock;
2049 	int status = -EIO;
2050 
2051 	sock = xs_create_sock(xprt, transport,
2052 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2053 			IPPROTO_UDP, false);
2054 	if (IS_ERR(sock))
2055 		goto out;
2056 
2057 	dprintk("RPC:       worker connecting xprt %p via %s to "
2058 				"%s (port %s)\n", xprt,
2059 			xprt->address_strings[RPC_DISPLAY_PROTO],
2060 			xprt->address_strings[RPC_DISPLAY_ADDR],
2061 			xprt->address_strings[RPC_DISPLAY_PORT]);
2062 
2063 	xs_udp_finish_connecting(xprt, sock);
2064 	trace_rpc_socket_connect(xprt, sock, 0);
2065 	status = 0;
2066 out:
2067 	xprt_clear_connecting(xprt);
2068 	xprt_unlock_connect(xprt, transport);
2069 	xprt_wake_pending_tasks(xprt, status);
2070 }
2071 
2072 /**
2073  * xs_tcp_shutdown - gracefully shut down a TCP socket
2074  * @xprt: transport
2075  *
2076  * Initiates a graceful shutdown of the TCP socket by calling the
2077  * equivalent of shutdown(SHUT_RDWR);
2078  */
2079 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2080 {
2081 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2082 	struct socket *sock = transport->sock;
2083 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2084 
2085 	if (sock == NULL)
2086 		return;
2087 	if (!xprt->reuseport) {
2088 		xs_close(xprt);
2089 		return;
2090 	}
2091 	switch (skst) {
2092 	case TCP_FIN_WAIT1:
2093 	case TCP_FIN_WAIT2:
2094 		break;
2095 	case TCP_ESTABLISHED:
2096 	case TCP_CLOSE_WAIT:
2097 		kernel_sock_shutdown(sock, SHUT_RDWR);
2098 		trace_rpc_socket_shutdown(xprt, sock);
2099 		break;
2100 	default:
2101 		xs_reset_transport(transport);
2102 	}
2103 }
2104 
2105 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2106 		struct socket *sock)
2107 {
2108 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2109 	unsigned int keepidle;
2110 	unsigned int keepcnt;
2111 	unsigned int timeo;
2112 
2113 	spin_lock(&xprt->transport_lock);
2114 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2115 	keepcnt = xprt->timeout->to_retries + 1;
2116 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2117 		(xprt->timeout->to_retries + 1);
2118 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2119 	spin_unlock(&xprt->transport_lock);
2120 
2121 	/* TCP Keepalive options */
2122 	sock_set_keepalive(sock->sk);
2123 	tcp_sock_set_keepidle(sock->sk, keepidle);
2124 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2125 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2126 
2127 	/* TCP user timeout (see RFC5482) */
2128 	tcp_sock_set_user_timeout(sock->sk, timeo);
2129 }
2130 
2131 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2132 		unsigned long connect_timeout,
2133 		unsigned long reconnect_timeout)
2134 {
2135 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2136 	struct rpc_timeout to;
2137 	unsigned long initval;
2138 
2139 	spin_lock(&xprt->transport_lock);
2140 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2141 		xprt->max_reconnect_timeout = reconnect_timeout;
2142 	if (connect_timeout < xprt->connect_timeout) {
2143 		memcpy(&to, xprt->timeout, sizeof(to));
2144 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2145 		/* Arbitrary lower limit */
2146 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2147 			initval = XS_TCP_INIT_REEST_TO << 1;
2148 		to.to_initval = initval;
2149 		to.to_maxval = initval;
2150 		memcpy(&transport->tcp_timeout, &to,
2151 				sizeof(transport->tcp_timeout));
2152 		xprt->timeout = &transport->tcp_timeout;
2153 		xprt->connect_timeout = connect_timeout;
2154 	}
2155 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2156 	spin_unlock(&xprt->transport_lock);
2157 }
2158 
2159 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2160 {
2161 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2162 
2163 	if (!transport->inet) {
2164 		struct sock *sk = sock->sk;
2165 
2166 		/* Avoid temporary address, they are bad for long-lived
2167 		 * connections such as NFS mounts.
2168 		 * RFC4941, section 3.6 suggests that:
2169 		 *    Individual applications, which have specific
2170 		 *    knowledge about the normal duration of connections,
2171 		 *    MAY override this as appropriate.
2172 		 */
2173 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2174 			ip6_sock_set_addr_preferences(sk,
2175 				IPV6_PREFER_SRC_PUBLIC);
2176 		}
2177 
2178 		xs_tcp_set_socket_timeouts(xprt, sock);
2179 		tcp_sock_set_nodelay(sk);
2180 
2181 		lock_sock(sk);
2182 
2183 		xs_save_old_callbacks(transport, sk);
2184 
2185 		sk->sk_user_data = xprt;
2186 		sk->sk_data_ready = xs_data_ready;
2187 		sk->sk_state_change = xs_tcp_state_change;
2188 		sk->sk_write_space = xs_tcp_write_space;
2189 		sock_set_flag(sk, SOCK_FASYNC);
2190 		sk->sk_error_report = xs_error_report;
2191 
2192 		/* socket options */
2193 		sock_reset_flag(sk, SOCK_LINGER);
2194 
2195 		xprt_clear_connected(xprt);
2196 
2197 		/* Reset to new socket */
2198 		transport->sock = sock;
2199 		transport->inet = sk;
2200 
2201 		release_sock(sk);
2202 	}
2203 
2204 	if (!xprt_bound(xprt))
2205 		return -ENOTCONN;
2206 
2207 	xs_set_memalloc(xprt);
2208 
2209 	xs_stream_start_connect(transport);
2210 
2211 	/* Tell the socket layer to start connecting... */
2212 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2213 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2214 }
2215 
2216 /**
2217  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2218  * @work: queued work item
2219  *
2220  * Invoked by a work queue tasklet.
2221  */
2222 static void xs_tcp_setup_socket(struct work_struct *work)
2223 {
2224 	struct sock_xprt *transport =
2225 		container_of(work, struct sock_xprt, connect_worker.work);
2226 	struct socket *sock = transport->sock;
2227 	struct rpc_xprt *xprt = &transport->xprt;
2228 	int status;
2229 
2230 	if (!sock) {
2231 		sock = xs_create_sock(xprt, transport,
2232 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2233 				IPPROTO_TCP, true);
2234 		if (IS_ERR(sock)) {
2235 			xprt_wake_pending_tasks(xprt, PTR_ERR(sock));
2236 			goto out;
2237 		}
2238 	}
2239 
2240 	dprintk("RPC:       worker connecting xprt %p via %s to "
2241 				"%s (port %s)\n", xprt,
2242 			xprt->address_strings[RPC_DISPLAY_PROTO],
2243 			xprt->address_strings[RPC_DISPLAY_ADDR],
2244 			xprt->address_strings[RPC_DISPLAY_PORT]);
2245 
2246 	status = xs_tcp_finish_connecting(xprt, sock);
2247 	trace_rpc_socket_connect(xprt, sock, status);
2248 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2249 			xprt, -status, xprt_connected(xprt),
2250 			sock->sk->sk_state);
2251 	switch (status) {
2252 	case 0:
2253 		xs_set_srcport(transport, sock);
2254 		fallthrough;
2255 	case -EINPROGRESS:
2256 		/* SYN_SENT! */
2257 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2258 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2259 		fallthrough;
2260 	case -EALREADY:
2261 		goto out_unlock;
2262 	case -EADDRNOTAVAIL:
2263 		/* Source port number is unavailable. Try a new one! */
2264 		transport->srcport = 0;
2265 		status = -EAGAIN;
2266 		break;
2267 	case -EINVAL:
2268 		/* Happens, for instance, if the user specified a link
2269 		 * local IPv6 address without a scope-id.
2270 		 */
2271 	case -ECONNREFUSED:
2272 	case -ECONNRESET:
2273 	case -ENETDOWN:
2274 	case -ENETUNREACH:
2275 	case -EHOSTUNREACH:
2276 	case -EADDRINUSE:
2277 	case -ENOBUFS:
2278 		break;
2279 	default:
2280 		printk("%s: connect returned unhandled error %d\n",
2281 			__func__, status);
2282 		status = -EAGAIN;
2283 	}
2284 
2285 	/* xs_tcp_force_close() wakes tasks with a fixed error code.
2286 	 * We need to wake them first to ensure the correct error code.
2287 	 */
2288 	xprt_wake_pending_tasks(xprt, status);
2289 	xs_tcp_force_close(xprt);
2290 out:
2291 	xprt_clear_connecting(xprt);
2292 out_unlock:
2293 	xprt_unlock_connect(xprt, transport);
2294 }
2295 
2296 /**
2297  * xs_connect - connect a socket to a remote endpoint
2298  * @xprt: pointer to transport structure
2299  * @task: address of RPC task that manages state of connect request
2300  *
2301  * TCP: If the remote end dropped the connection, delay reconnecting.
2302  *
2303  * UDP socket connects are synchronous, but we use a work queue anyway
2304  * to guarantee that even unprivileged user processes can set up a
2305  * socket on a privileged port.
2306  *
2307  * If a UDP socket connect fails, the delay behavior here prevents
2308  * retry floods (hard mounts).
2309  */
2310 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2311 {
2312 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2313 	unsigned long delay = 0;
2314 
2315 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2316 
2317 	if (transport->sock != NULL && !xprt_connecting(xprt)) {
2318 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2319 				"seconds\n",
2320 				xprt, xprt->reestablish_timeout / HZ);
2321 
2322 		/* Start by resetting any existing state */
2323 		xs_reset_transport(transport);
2324 
2325 		delay = xprt_reconnect_delay(xprt);
2326 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2327 
2328 	} else
2329 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2330 
2331 	queue_delayed_work(xprtiod_workqueue,
2332 			&transport->connect_worker,
2333 			delay);
2334 }
2335 
2336 static void xs_wake_disconnect(struct sock_xprt *transport)
2337 {
2338 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2339 		xs_tcp_force_close(&transport->xprt);
2340 }
2341 
2342 static void xs_wake_write(struct sock_xprt *transport)
2343 {
2344 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2345 		xprt_write_space(&transport->xprt);
2346 }
2347 
2348 static void xs_wake_error(struct sock_xprt *transport)
2349 {
2350 	int sockerr;
2351 
2352 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2353 		return;
2354 	mutex_lock(&transport->recv_mutex);
2355 	if (transport->sock == NULL)
2356 		goto out;
2357 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2358 		goto out;
2359 	sockerr = xchg(&transport->xprt_err, 0);
2360 	if (sockerr < 0)
2361 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2362 out:
2363 	mutex_unlock(&transport->recv_mutex);
2364 }
2365 
2366 static void xs_wake_pending(struct sock_xprt *transport)
2367 {
2368 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2369 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2370 }
2371 
2372 static void xs_error_handle(struct work_struct *work)
2373 {
2374 	struct sock_xprt *transport = container_of(work,
2375 			struct sock_xprt, error_worker);
2376 
2377 	xs_wake_disconnect(transport);
2378 	xs_wake_write(transport);
2379 	xs_wake_error(transport);
2380 	xs_wake_pending(transport);
2381 }
2382 
2383 /**
2384  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2385  * @xprt: rpc_xprt struct containing statistics
2386  * @seq: output file
2387  *
2388  */
2389 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2390 {
2391 	long idle_time = 0;
2392 
2393 	if (xprt_connected(xprt))
2394 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2395 
2396 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2397 			"%llu %llu %lu %llu %llu\n",
2398 			xprt->stat.bind_count,
2399 			xprt->stat.connect_count,
2400 			xprt->stat.connect_time / HZ,
2401 			idle_time,
2402 			xprt->stat.sends,
2403 			xprt->stat.recvs,
2404 			xprt->stat.bad_xids,
2405 			xprt->stat.req_u,
2406 			xprt->stat.bklog_u,
2407 			xprt->stat.max_slots,
2408 			xprt->stat.sending_u,
2409 			xprt->stat.pending_u);
2410 }
2411 
2412 /**
2413  * xs_udp_print_stats - display UDP socket-specific stats
2414  * @xprt: rpc_xprt struct containing statistics
2415  * @seq: output file
2416  *
2417  */
2418 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2419 {
2420 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2421 
2422 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2423 			"%lu %llu %llu\n",
2424 			transport->srcport,
2425 			xprt->stat.bind_count,
2426 			xprt->stat.sends,
2427 			xprt->stat.recvs,
2428 			xprt->stat.bad_xids,
2429 			xprt->stat.req_u,
2430 			xprt->stat.bklog_u,
2431 			xprt->stat.max_slots,
2432 			xprt->stat.sending_u,
2433 			xprt->stat.pending_u);
2434 }
2435 
2436 /**
2437  * xs_tcp_print_stats - display TCP socket-specific stats
2438  * @xprt: rpc_xprt struct containing statistics
2439  * @seq: output file
2440  *
2441  */
2442 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2443 {
2444 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2445 	long idle_time = 0;
2446 
2447 	if (xprt_connected(xprt))
2448 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2449 
2450 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2451 			"%llu %llu %lu %llu %llu\n",
2452 			transport->srcport,
2453 			xprt->stat.bind_count,
2454 			xprt->stat.connect_count,
2455 			xprt->stat.connect_time / HZ,
2456 			idle_time,
2457 			xprt->stat.sends,
2458 			xprt->stat.recvs,
2459 			xprt->stat.bad_xids,
2460 			xprt->stat.req_u,
2461 			xprt->stat.bklog_u,
2462 			xprt->stat.max_slots,
2463 			xprt->stat.sending_u,
2464 			xprt->stat.pending_u);
2465 }
2466 
2467 /*
2468  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2469  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2470  * to use the server side send routines.
2471  */
2472 static int bc_malloc(struct rpc_task *task)
2473 {
2474 	struct rpc_rqst *rqst = task->tk_rqstp;
2475 	size_t size = rqst->rq_callsize;
2476 	struct page *page;
2477 	struct rpc_buffer *buf;
2478 
2479 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2480 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2481 			  size);
2482 		return -EINVAL;
2483 	}
2484 
2485 	page = alloc_page(GFP_KERNEL);
2486 	if (!page)
2487 		return -ENOMEM;
2488 
2489 	buf = page_address(page);
2490 	buf->len = PAGE_SIZE;
2491 
2492 	rqst->rq_buffer = buf->data;
2493 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2494 	return 0;
2495 }
2496 
2497 /*
2498  * Free the space allocated in the bc_alloc routine
2499  */
2500 static void bc_free(struct rpc_task *task)
2501 {
2502 	void *buffer = task->tk_rqstp->rq_buffer;
2503 	struct rpc_buffer *buf;
2504 
2505 	buf = container_of(buffer, struct rpc_buffer, data);
2506 	free_page((unsigned long)buf);
2507 }
2508 
2509 static int bc_sendto(struct rpc_rqst *req)
2510 {
2511 	struct xdr_buf *xdr = &req->rq_snd_buf;
2512 	struct sock_xprt *transport =
2513 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2514 	struct msghdr msg = {
2515 		.msg_flags	= 0,
2516 	};
2517 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2518 					 (u32)xdr->len);
2519 	unsigned int sent = 0;
2520 	int err;
2521 
2522 	req->rq_xtime = ktime_get();
2523 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2524 	xdr_free_bvec(xdr);
2525 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2526 		return -EAGAIN;
2527 	return sent;
2528 }
2529 
2530 /**
2531  * bc_send_request - Send a backchannel Call on a TCP socket
2532  * @req: rpc_rqst containing Call message to be sent
2533  *
2534  * xpt_mutex ensures @rqstp's whole message is written to the socket
2535  * without interruption.
2536  *
2537  * Return values:
2538  *   %0 if the message was sent successfully
2539  *   %ENOTCONN if the message was not sent
2540  */
2541 static int bc_send_request(struct rpc_rqst *req)
2542 {
2543 	struct svc_xprt	*xprt;
2544 	int len;
2545 
2546 	/*
2547 	 * Get the server socket associated with this callback xprt
2548 	 */
2549 	xprt = req->rq_xprt->bc_xprt;
2550 
2551 	/*
2552 	 * Grab the mutex to serialize data as the connection is shared
2553 	 * with the fore channel
2554 	 */
2555 	mutex_lock(&xprt->xpt_mutex);
2556 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2557 		len = -ENOTCONN;
2558 	else
2559 		len = bc_sendto(req);
2560 	mutex_unlock(&xprt->xpt_mutex);
2561 
2562 	if (len > 0)
2563 		len = 0;
2564 
2565 	return len;
2566 }
2567 
2568 /*
2569  * The close routine. Since this is client initiated, we do nothing
2570  */
2571 
2572 static void bc_close(struct rpc_xprt *xprt)
2573 {
2574 	xprt_disconnect_done(xprt);
2575 }
2576 
2577 /*
2578  * The xprt destroy routine. Again, because this connection is client
2579  * initiated, we do nothing
2580  */
2581 
2582 static void bc_destroy(struct rpc_xprt *xprt)
2583 {
2584 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2585 
2586 	xs_xprt_free(xprt);
2587 	module_put(THIS_MODULE);
2588 }
2589 
2590 static const struct rpc_xprt_ops xs_local_ops = {
2591 	.reserve_xprt		= xprt_reserve_xprt,
2592 	.release_xprt		= xprt_release_xprt,
2593 	.alloc_slot		= xprt_alloc_slot,
2594 	.free_slot		= xprt_free_slot,
2595 	.rpcbind		= xs_local_rpcbind,
2596 	.set_port		= xs_local_set_port,
2597 	.connect		= xs_local_connect,
2598 	.buf_alloc		= rpc_malloc,
2599 	.buf_free		= rpc_free,
2600 	.prepare_request	= xs_stream_prepare_request,
2601 	.send_request		= xs_local_send_request,
2602 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2603 	.close			= xs_close,
2604 	.destroy		= xs_destroy,
2605 	.print_stats		= xs_local_print_stats,
2606 	.enable_swap		= xs_enable_swap,
2607 	.disable_swap		= xs_disable_swap,
2608 };
2609 
2610 static const struct rpc_xprt_ops xs_udp_ops = {
2611 	.set_buffer_size	= xs_udp_set_buffer_size,
2612 	.reserve_xprt		= xprt_reserve_xprt_cong,
2613 	.release_xprt		= xprt_release_xprt_cong,
2614 	.alloc_slot		= xprt_alloc_slot,
2615 	.free_slot		= xprt_free_slot,
2616 	.rpcbind		= rpcb_getport_async,
2617 	.set_port		= xs_set_port,
2618 	.connect		= xs_connect,
2619 	.buf_alloc		= rpc_malloc,
2620 	.buf_free		= rpc_free,
2621 	.send_request		= xs_udp_send_request,
2622 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2623 	.timer			= xs_udp_timer,
2624 	.release_request	= xprt_release_rqst_cong,
2625 	.close			= xs_close,
2626 	.destroy		= xs_destroy,
2627 	.print_stats		= xs_udp_print_stats,
2628 	.enable_swap		= xs_enable_swap,
2629 	.disable_swap		= xs_disable_swap,
2630 	.inject_disconnect	= xs_inject_disconnect,
2631 };
2632 
2633 static const struct rpc_xprt_ops xs_tcp_ops = {
2634 	.reserve_xprt		= xprt_reserve_xprt,
2635 	.release_xprt		= xprt_release_xprt,
2636 	.alloc_slot		= xprt_alloc_slot,
2637 	.free_slot		= xprt_free_slot,
2638 	.rpcbind		= rpcb_getport_async,
2639 	.set_port		= xs_set_port,
2640 	.connect		= xs_connect,
2641 	.buf_alloc		= rpc_malloc,
2642 	.buf_free		= rpc_free,
2643 	.prepare_request	= xs_stream_prepare_request,
2644 	.send_request		= xs_tcp_send_request,
2645 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2646 	.close			= xs_tcp_shutdown,
2647 	.destroy		= xs_destroy,
2648 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2649 	.print_stats		= xs_tcp_print_stats,
2650 	.enable_swap		= xs_enable_swap,
2651 	.disable_swap		= xs_disable_swap,
2652 	.inject_disconnect	= xs_inject_disconnect,
2653 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2654 	.bc_setup		= xprt_setup_bc,
2655 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2656 	.bc_num_slots		= xprt_bc_max_slots,
2657 	.bc_free_rqst		= xprt_free_bc_rqst,
2658 	.bc_destroy		= xprt_destroy_bc,
2659 #endif
2660 };
2661 
2662 /*
2663  * The rpc_xprt_ops for the server backchannel
2664  */
2665 
2666 static const struct rpc_xprt_ops bc_tcp_ops = {
2667 	.reserve_xprt		= xprt_reserve_xprt,
2668 	.release_xprt		= xprt_release_xprt,
2669 	.alloc_slot		= xprt_alloc_slot,
2670 	.free_slot		= xprt_free_slot,
2671 	.buf_alloc		= bc_malloc,
2672 	.buf_free		= bc_free,
2673 	.send_request		= bc_send_request,
2674 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2675 	.close			= bc_close,
2676 	.destroy		= bc_destroy,
2677 	.print_stats		= xs_tcp_print_stats,
2678 	.enable_swap		= xs_enable_swap,
2679 	.disable_swap		= xs_disable_swap,
2680 	.inject_disconnect	= xs_inject_disconnect,
2681 };
2682 
2683 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2684 {
2685 	static const struct sockaddr_in sin = {
2686 		.sin_family		= AF_INET,
2687 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2688 	};
2689 	static const struct sockaddr_in6 sin6 = {
2690 		.sin6_family		= AF_INET6,
2691 		.sin6_addr		= IN6ADDR_ANY_INIT,
2692 	};
2693 
2694 	switch (family) {
2695 	case AF_LOCAL:
2696 		break;
2697 	case AF_INET:
2698 		memcpy(sap, &sin, sizeof(sin));
2699 		break;
2700 	case AF_INET6:
2701 		memcpy(sap, &sin6, sizeof(sin6));
2702 		break;
2703 	default:
2704 		dprintk("RPC:       %s: Bad address family\n", __func__);
2705 		return -EAFNOSUPPORT;
2706 	}
2707 	return 0;
2708 }
2709 
2710 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2711 				      unsigned int slot_table_size,
2712 				      unsigned int max_slot_table_size)
2713 {
2714 	struct rpc_xprt *xprt;
2715 	struct sock_xprt *new;
2716 
2717 	if (args->addrlen > sizeof(xprt->addr)) {
2718 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2719 		return ERR_PTR(-EBADF);
2720 	}
2721 
2722 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2723 			max_slot_table_size);
2724 	if (xprt == NULL) {
2725 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2726 				"rpc_xprt\n");
2727 		return ERR_PTR(-ENOMEM);
2728 	}
2729 
2730 	new = container_of(xprt, struct sock_xprt, xprt);
2731 	mutex_init(&new->recv_mutex);
2732 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2733 	xprt->addrlen = args->addrlen;
2734 	if (args->srcaddr)
2735 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2736 	else {
2737 		int err;
2738 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2739 					(struct sockaddr *)&new->srcaddr);
2740 		if (err != 0) {
2741 			xprt_free(xprt);
2742 			return ERR_PTR(err);
2743 		}
2744 	}
2745 
2746 	return xprt;
2747 }
2748 
2749 static const struct rpc_timeout xs_local_default_timeout = {
2750 	.to_initval = 10 * HZ,
2751 	.to_maxval = 10 * HZ,
2752 	.to_retries = 2,
2753 };
2754 
2755 /**
2756  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2757  * @args: rpc transport creation arguments
2758  *
2759  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2760  */
2761 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2762 {
2763 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2764 	struct sock_xprt *transport;
2765 	struct rpc_xprt *xprt;
2766 	struct rpc_xprt *ret;
2767 
2768 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2769 			xprt_max_tcp_slot_table_entries);
2770 	if (IS_ERR(xprt))
2771 		return xprt;
2772 	transport = container_of(xprt, struct sock_xprt, xprt);
2773 
2774 	xprt->prot = 0;
2775 	xprt->xprt_class = &xs_local_transport;
2776 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2777 
2778 	xprt->bind_timeout = XS_BIND_TO;
2779 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2780 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2781 
2782 	xprt->ops = &xs_local_ops;
2783 	xprt->timeout = &xs_local_default_timeout;
2784 
2785 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2786 	INIT_WORK(&transport->error_worker, xs_error_handle);
2787 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2788 
2789 	switch (sun->sun_family) {
2790 	case AF_LOCAL:
2791 		if (sun->sun_path[0] != '/') {
2792 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2793 					sun->sun_path);
2794 			ret = ERR_PTR(-EINVAL);
2795 			goto out_err;
2796 		}
2797 		xprt_set_bound(xprt);
2798 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2799 		ret = ERR_PTR(xs_local_setup_socket(transport));
2800 		if (ret)
2801 			goto out_err;
2802 		break;
2803 	default:
2804 		ret = ERR_PTR(-EAFNOSUPPORT);
2805 		goto out_err;
2806 	}
2807 
2808 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2809 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2810 
2811 	if (try_module_get(THIS_MODULE))
2812 		return xprt;
2813 	ret = ERR_PTR(-EINVAL);
2814 out_err:
2815 	xs_xprt_free(xprt);
2816 	return ret;
2817 }
2818 
2819 static const struct rpc_timeout xs_udp_default_timeout = {
2820 	.to_initval = 5 * HZ,
2821 	.to_maxval = 30 * HZ,
2822 	.to_increment = 5 * HZ,
2823 	.to_retries = 5,
2824 };
2825 
2826 /**
2827  * xs_setup_udp - Set up transport to use a UDP socket
2828  * @args: rpc transport creation arguments
2829  *
2830  */
2831 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2832 {
2833 	struct sockaddr *addr = args->dstaddr;
2834 	struct rpc_xprt *xprt;
2835 	struct sock_xprt *transport;
2836 	struct rpc_xprt *ret;
2837 
2838 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2839 			xprt_udp_slot_table_entries);
2840 	if (IS_ERR(xprt))
2841 		return xprt;
2842 	transport = container_of(xprt, struct sock_xprt, xprt);
2843 
2844 	xprt->prot = IPPROTO_UDP;
2845 	xprt->xprt_class = &xs_udp_transport;
2846 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2847 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2848 
2849 	xprt->bind_timeout = XS_BIND_TO;
2850 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2851 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2852 
2853 	xprt->ops = &xs_udp_ops;
2854 
2855 	xprt->timeout = &xs_udp_default_timeout;
2856 
2857 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2858 	INIT_WORK(&transport->error_worker, xs_error_handle);
2859 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2860 
2861 	switch (addr->sa_family) {
2862 	case AF_INET:
2863 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2864 			xprt_set_bound(xprt);
2865 
2866 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2867 		break;
2868 	case AF_INET6:
2869 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2870 			xprt_set_bound(xprt);
2871 
2872 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2873 		break;
2874 	default:
2875 		ret = ERR_PTR(-EAFNOSUPPORT);
2876 		goto out_err;
2877 	}
2878 
2879 	if (xprt_bound(xprt))
2880 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2881 				xprt->address_strings[RPC_DISPLAY_ADDR],
2882 				xprt->address_strings[RPC_DISPLAY_PORT],
2883 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2884 	else
2885 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2886 				xprt->address_strings[RPC_DISPLAY_ADDR],
2887 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2888 
2889 	if (try_module_get(THIS_MODULE))
2890 		return xprt;
2891 	ret = ERR_PTR(-EINVAL);
2892 out_err:
2893 	xs_xprt_free(xprt);
2894 	return ret;
2895 }
2896 
2897 static const struct rpc_timeout xs_tcp_default_timeout = {
2898 	.to_initval = 60 * HZ,
2899 	.to_maxval = 60 * HZ,
2900 	.to_retries = 2,
2901 };
2902 
2903 /**
2904  * xs_setup_tcp - Set up transport to use a TCP socket
2905  * @args: rpc transport creation arguments
2906  *
2907  */
2908 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2909 {
2910 	struct sockaddr *addr = args->dstaddr;
2911 	struct rpc_xprt *xprt;
2912 	struct sock_xprt *transport;
2913 	struct rpc_xprt *ret;
2914 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2915 
2916 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2917 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2918 
2919 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2920 			max_slot_table_size);
2921 	if (IS_ERR(xprt))
2922 		return xprt;
2923 	transport = container_of(xprt, struct sock_xprt, xprt);
2924 
2925 	xprt->prot = IPPROTO_TCP;
2926 	xprt->xprt_class = &xs_tcp_transport;
2927 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2928 
2929 	xprt->bind_timeout = XS_BIND_TO;
2930 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2931 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2932 
2933 	xprt->ops = &xs_tcp_ops;
2934 	xprt->timeout = &xs_tcp_default_timeout;
2935 
2936 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2937 	xprt->connect_timeout = xprt->timeout->to_initval *
2938 		(xprt->timeout->to_retries + 1);
2939 
2940 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2941 	INIT_WORK(&transport->error_worker, xs_error_handle);
2942 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2943 
2944 	switch (addr->sa_family) {
2945 	case AF_INET:
2946 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2947 			xprt_set_bound(xprt);
2948 
2949 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2950 		break;
2951 	case AF_INET6:
2952 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2953 			xprt_set_bound(xprt);
2954 
2955 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2956 		break;
2957 	default:
2958 		ret = ERR_PTR(-EAFNOSUPPORT);
2959 		goto out_err;
2960 	}
2961 
2962 	if (xprt_bound(xprt))
2963 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2964 				xprt->address_strings[RPC_DISPLAY_ADDR],
2965 				xprt->address_strings[RPC_DISPLAY_PORT],
2966 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2967 	else
2968 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2969 				xprt->address_strings[RPC_DISPLAY_ADDR],
2970 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2971 
2972 	if (try_module_get(THIS_MODULE))
2973 		return xprt;
2974 	ret = ERR_PTR(-EINVAL);
2975 out_err:
2976 	xs_xprt_free(xprt);
2977 	return ret;
2978 }
2979 
2980 /**
2981  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2982  * @args: rpc transport creation arguments
2983  *
2984  */
2985 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2986 {
2987 	struct sockaddr *addr = args->dstaddr;
2988 	struct rpc_xprt *xprt;
2989 	struct sock_xprt *transport;
2990 	struct svc_sock *bc_sock;
2991 	struct rpc_xprt *ret;
2992 
2993 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2994 			xprt_tcp_slot_table_entries);
2995 	if (IS_ERR(xprt))
2996 		return xprt;
2997 	transport = container_of(xprt, struct sock_xprt, xprt);
2998 
2999 	xprt->prot = IPPROTO_TCP;
3000 	xprt->xprt_class = &xs_bc_tcp_transport;
3001 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3002 	xprt->timeout = &xs_tcp_default_timeout;
3003 
3004 	/* backchannel */
3005 	xprt_set_bound(xprt);
3006 	xprt->bind_timeout = 0;
3007 	xprt->reestablish_timeout = 0;
3008 	xprt->idle_timeout = 0;
3009 
3010 	xprt->ops = &bc_tcp_ops;
3011 
3012 	switch (addr->sa_family) {
3013 	case AF_INET:
3014 		xs_format_peer_addresses(xprt, "tcp",
3015 					 RPCBIND_NETID_TCP);
3016 		break;
3017 	case AF_INET6:
3018 		xs_format_peer_addresses(xprt, "tcp",
3019 				   RPCBIND_NETID_TCP6);
3020 		break;
3021 	default:
3022 		ret = ERR_PTR(-EAFNOSUPPORT);
3023 		goto out_err;
3024 	}
3025 
3026 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3027 			xprt->address_strings[RPC_DISPLAY_ADDR],
3028 			xprt->address_strings[RPC_DISPLAY_PORT],
3029 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3030 
3031 	/*
3032 	 * Once we've associated a backchannel xprt with a connection,
3033 	 * we want to keep it around as long as the connection lasts,
3034 	 * in case we need to start using it for a backchannel again;
3035 	 * this reference won't be dropped until bc_xprt is destroyed.
3036 	 */
3037 	xprt_get(xprt);
3038 	args->bc_xprt->xpt_bc_xprt = xprt;
3039 	xprt->bc_xprt = args->bc_xprt;
3040 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3041 	transport->sock = bc_sock->sk_sock;
3042 	transport->inet = bc_sock->sk_sk;
3043 
3044 	/*
3045 	 * Since we don't want connections for the backchannel, we set
3046 	 * the xprt status to connected
3047 	 */
3048 	xprt_set_connected(xprt);
3049 
3050 	if (try_module_get(THIS_MODULE))
3051 		return xprt;
3052 
3053 	args->bc_xprt->xpt_bc_xprt = NULL;
3054 	args->bc_xprt->xpt_bc_xps = NULL;
3055 	xprt_put(xprt);
3056 	ret = ERR_PTR(-EINVAL);
3057 out_err:
3058 	xs_xprt_free(xprt);
3059 	return ret;
3060 }
3061 
3062 static struct xprt_class	xs_local_transport = {
3063 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3064 	.name		= "named UNIX socket",
3065 	.owner		= THIS_MODULE,
3066 	.ident		= XPRT_TRANSPORT_LOCAL,
3067 	.setup		= xs_setup_local,
3068 	.netid		= { "" },
3069 };
3070 
3071 static struct xprt_class	xs_udp_transport = {
3072 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3073 	.name		= "udp",
3074 	.owner		= THIS_MODULE,
3075 	.ident		= XPRT_TRANSPORT_UDP,
3076 	.setup		= xs_setup_udp,
3077 	.netid		= { "udp", "udp6", "" },
3078 };
3079 
3080 static struct xprt_class	xs_tcp_transport = {
3081 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3082 	.name		= "tcp",
3083 	.owner		= THIS_MODULE,
3084 	.ident		= XPRT_TRANSPORT_TCP,
3085 	.setup		= xs_setup_tcp,
3086 	.netid		= { "tcp", "tcp6", "" },
3087 };
3088 
3089 static struct xprt_class	xs_bc_tcp_transport = {
3090 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3091 	.name		= "tcp NFSv4.1 backchannel",
3092 	.owner		= THIS_MODULE,
3093 	.ident		= XPRT_TRANSPORT_BC_TCP,
3094 	.setup		= xs_setup_bc_tcp,
3095 	.netid		= { "" },
3096 };
3097 
3098 /**
3099  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3100  *
3101  */
3102 int init_socket_xprt(void)
3103 {
3104 	if (!sunrpc_table_header)
3105 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3106 
3107 	xprt_register_transport(&xs_local_transport);
3108 	xprt_register_transport(&xs_udp_transport);
3109 	xprt_register_transport(&xs_tcp_transport);
3110 	xprt_register_transport(&xs_bc_tcp_transport);
3111 
3112 	return 0;
3113 }
3114 
3115 /**
3116  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3117  *
3118  */
3119 void cleanup_socket_xprt(void)
3120 {
3121 	if (sunrpc_table_header) {
3122 		unregister_sysctl_table(sunrpc_table_header);
3123 		sunrpc_table_header = NULL;
3124 	}
3125 
3126 	xprt_unregister_transport(&xs_local_transport);
3127 	xprt_unregister_transport(&xs_udp_transport);
3128 	xprt_unregister_transport(&xs_tcp_transport);
3129 	xprt_unregister_transport(&xs_bc_tcp_transport);
3130 }
3131 
3132 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3133 {
3134 	return param_set_uint_minmax(val, kp,
3135 			RPC_MIN_RESVPORT,
3136 			RPC_MAX_RESVPORT);
3137 }
3138 
3139 static const struct kernel_param_ops param_ops_portnr = {
3140 	.set = param_set_portnr,
3141 	.get = param_get_uint,
3142 };
3143 
3144 #define param_check_portnr(name, p) \
3145 	__param_check(name, p, unsigned int);
3146 
3147 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3148 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3149 
3150 static int param_set_slot_table_size(const char *val,
3151 				     const struct kernel_param *kp)
3152 {
3153 	return param_set_uint_minmax(val, kp,
3154 			RPC_MIN_SLOT_TABLE,
3155 			RPC_MAX_SLOT_TABLE);
3156 }
3157 
3158 static const struct kernel_param_ops param_ops_slot_table_size = {
3159 	.set = param_set_slot_table_size,
3160 	.get = param_get_uint,
3161 };
3162 
3163 #define param_check_slot_table_size(name, p) \
3164 	__param_check(name, p, unsigned int);
3165 
3166 static int param_set_max_slot_table_size(const char *val,
3167 				     const struct kernel_param *kp)
3168 {
3169 	return param_set_uint_minmax(val, kp,
3170 			RPC_MIN_SLOT_TABLE,
3171 			RPC_MAX_SLOT_TABLE_LIMIT);
3172 }
3173 
3174 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3175 	.set = param_set_max_slot_table_size,
3176 	.get = param_get_uint,
3177 };
3178 
3179 #define param_check_max_slot_table_size(name, p) \
3180 	__param_check(name, p, unsigned int);
3181 
3182 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3183 		   slot_table_size, 0644);
3184 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3185 		   max_slot_table_size, 0644);
3186 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3187 		   slot_table_size, 0644);
3188