xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 2c86446f)
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 	smp_mb__before_atomic();
1138 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1139 	clear_bit(XPRT_CLOSING, &xprt->state);
1140 	xs_sock_reset_state_flags(xprt);
1141 	smp_mb__after_atomic();
1142 }
1143 
1144 /**
1145  * xs_error_report - callback to handle TCP socket state errors
1146  * @sk: socket
1147  *
1148  * Note: we don't call sock_error() since there may be a rpc_task
1149  * using the socket, and so we don't want to clear sk->sk_err.
1150  */
1151 static void xs_error_report(struct sock *sk)
1152 {
1153 	struct sock_xprt *transport;
1154 	struct rpc_xprt *xprt;
1155 
1156 	read_lock_bh(&sk->sk_callback_lock);
1157 	if (!(xprt = xprt_from_sock(sk)))
1158 		goto out;
1159 
1160 	transport = container_of(xprt, struct sock_xprt, xprt);
1161 	transport->xprt_err = -sk->sk_err;
1162 	if (transport->xprt_err == 0)
1163 		goto out;
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  out:
1172 	read_unlock_bh(&sk->sk_callback_lock);
1173 }
1174 
1175 static void xs_reset_transport(struct sock_xprt *transport)
1176 {
1177 	struct socket *sock = transport->sock;
1178 	struct sock *sk = transport->inet;
1179 	struct rpc_xprt *xprt = &transport->xprt;
1180 	struct file *filp = transport->file;
1181 
1182 	if (sk == NULL)
1183 		return;
1184 
1185 	if (atomic_read(&transport->xprt.swapper))
1186 		sk_clear_memalloc(sk);
1187 
1188 	kernel_sock_shutdown(sock, SHUT_RDWR);
1189 
1190 	mutex_lock(&transport->recv_mutex);
1191 	write_lock_bh(&sk->sk_callback_lock);
1192 	transport->inet = NULL;
1193 	transport->sock = NULL;
1194 	transport->file = NULL;
1195 
1196 	sk->sk_user_data = NULL;
1197 
1198 	xs_restore_old_callbacks(transport, sk);
1199 	xprt_clear_connected(xprt);
1200 	write_unlock_bh(&sk->sk_callback_lock);
1201 	xs_sock_reset_connection_flags(xprt);
1202 	/* Reset stream record info */
1203 	xs_stream_reset_connect(transport);
1204 	mutex_unlock(&transport->recv_mutex);
1205 
1206 	trace_rpc_socket_close(xprt, sock);
1207 	fput(filp);
1208 
1209 	xprt_disconnect_done(xprt);
1210 }
1211 
1212 /**
1213  * xs_close - close a socket
1214  * @xprt: transport
1215  *
1216  * This is used when all requests are complete; ie, no DRC state remains
1217  * on the server we want to save.
1218  *
1219  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1220  * xs_reset_transport() zeroing the socket from underneath a writer.
1221  */
1222 static void xs_close(struct rpc_xprt *xprt)
1223 {
1224 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1225 
1226 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1227 
1228 	xs_reset_transport(transport);
1229 	xprt->reestablish_timeout = 0;
1230 }
1231 
1232 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1233 {
1234 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1235 		xprt);
1236 	xprt_disconnect_done(xprt);
1237 }
1238 
1239 static void xs_xprt_free(struct rpc_xprt *xprt)
1240 {
1241 	xs_free_peer_addresses(xprt);
1242 	xprt_free(xprt);
1243 }
1244 
1245 /**
1246  * xs_destroy - prepare to shutdown a transport
1247  * @xprt: doomed transport
1248  *
1249  */
1250 static void xs_destroy(struct rpc_xprt *xprt)
1251 {
1252 	struct sock_xprt *transport = container_of(xprt,
1253 			struct sock_xprt, xprt);
1254 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1255 
1256 	cancel_delayed_work_sync(&transport->connect_worker);
1257 	xs_close(xprt);
1258 	cancel_work_sync(&transport->recv_worker);
1259 	cancel_work_sync(&transport->error_worker);
1260 	xs_xprt_free(xprt);
1261 	module_put(THIS_MODULE);
1262 }
1263 
1264 /**
1265  * xs_udp_data_read_skb - receive callback for UDP sockets
1266  * @xprt: transport
1267  * @sk: socket
1268  * @skb: skbuff
1269  *
1270  */
1271 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1272 		struct sock *sk,
1273 		struct sk_buff *skb)
1274 {
1275 	struct rpc_task *task;
1276 	struct rpc_rqst *rovr;
1277 	int repsize, copied;
1278 	u32 _xid;
1279 	__be32 *xp;
1280 
1281 	repsize = skb->len;
1282 	if (repsize < 4) {
1283 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1284 		return;
1285 	}
1286 
1287 	/* Copy the XID from the skb... */
1288 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1289 	if (xp == NULL)
1290 		return;
1291 
1292 	/* Look up and lock the request corresponding to the given XID */
1293 	spin_lock(&xprt->queue_lock);
1294 	rovr = xprt_lookup_rqst(xprt, *xp);
1295 	if (!rovr)
1296 		goto out_unlock;
1297 	xprt_pin_rqst(rovr);
1298 	xprt_update_rtt(rovr->rq_task);
1299 	spin_unlock(&xprt->queue_lock);
1300 	task = rovr->rq_task;
1301 
1302 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1303 		copied = repsize;
1304 
1305 	/* Suck it into the iovec, verify checksum if not done by hw. */
1306 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1307 		spin_lock(&xprt->queue_lock);
1308 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1309 		goto out_unpin;
1310 	}
1311 
1312 
1313 	spin_lock(&xprt->transport_lock);
1314 	xprt_adjust_cwnd(xprt, task, copied);
1315 	spin_unlock(&xprt->transport_lock);
1316 	spin_lock(&xprt->queue_lock);
1317 	xprt_complete_rqst(task, copied);
1318 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1319 out_unpin:
1320 	xprt_unpin_rqst(rovr);
1321  out_unlock:
1322 	spin_unlock(&xprt->queue_lock);
1323 }
1324 
1325 static void xs_udp_data_receive(struct sock_xprt *transport)
1326 {
1327 	struct sk_buff *skb;
1328 	struct sock *sk;
1329 	int err;
1330 
1331 	mutex_lock(&transport->recv_mutex);
1332 	sk = transport->inet;
1333 	if (sk == NULL)
1334 		goto out;
1335 	for (;;) {
1336 		skb = skb_recv_udp(sk, 0, 1, &err);
1337 		if (skb == NULL)
1338 			break;
1339 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1340 		consume_skb(skb);
1341 		cond_resched();
1342 	}
1343 	xs_poll_check_readable(transport);
1344 out:
1345 	mutex_unlock(&transport->recv_mutex);
1346 }
1347 
1348 static void xs_udp_data_receive_workfn(struct work_struct *work)
1349 {
1350 	struct sock_xprt *transport =
1351 		container_of(work, struct sock_xprt, recv_worker);
1352 	unsigned int pflags = memalloc_nofs_save();
1353 
1354 	xs_udp_data_receive(transport);
1355 	memalloc_nofs_restore(pflags);
1356 }
1357 
1358 /**
1359  * xs_data_ready - "data ready" callback for UDP sockets
1360  * @sk: socket with data to read
1361  *
1362  */
1363 static void xs_data_ready(struct sock *sk)
1364 {
1365 	struct rpc_xprt *xprt;
1366 
1367 	read_lock_bh(&sk->sk_callback_lock);
1368 	dprintk("RPC:       xs_data_ready...\n");
1369 	xprt = xprt_from_sock(sk);
1370 	if (xprt != NULL) {
1371 		struct sock_xprt *transport = container_of(xprt,
1372 				struct sock_xprt, xprt);
1373 		transport->old_data_ready(sk);
1374 		/* Any data means we had a useful conversation, so
1375 		 * then we don't need to delay the next reconnect
1376 		 */
1377 		if (xprt->reestablish_timeout)
1378 			xprt->reestablish_timeout = 0;
1379 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1380 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1381 	}
1382 	read_unlock_bh(&sk->sk_callback_lock);
1383 }
1384 
1385 /*
1386  * Helper function to force a TCP close if the server is sending
1387  * junk and/or it has put us in CLOSE_WAIT
1388  */
1389 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1390 {
1391 	xprt_force_disconnect(xprt);
1392 }
1393 
1394 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1395 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1396 {
1397 	return PAGE_SIZE;
1398 }
1399 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1400 
1401 /**
1402  * xs_tcp_state_change - callback to handle TCP socket state changes
1403  * @sk: socket whose state has changed
1404  *
1405  */
1406 static void xs_tcp_state_change(struct sock *sk)
1407 {
1408 	struct rpc_xprt *xprt;
1409 	struct sock_xprt *transport;
1410 
1411 	read_lock_bh(&sk->sk_callback_lock);
1412 	if (!(xprt = xprt_from_sock(sk)))
1413 		goto out;
1414 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1415 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1416 			sk->sk_state, xprt_connected(xprt),
1417 			sock_flag(sk, SOCK_DEAD),
1418 			sock_flag(sk, SOCK_ZAPPED),
1419 			sk->sk_shutdown);
1420 
1421 	transport = container_of(xprt, struct sock_xprt, xprt);
1422 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1423 	switch (sk->sk_state) {
1424 	case TCP_ESTABLISHED:
1425 		if (!xprt_test_and_set_connected(xprt)) {
1426 			xprt->connect_cookie++;
1427 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1428 			xprt_clear_connecting(xprt);
1429 
1430 			xprt->stat.connect_count++;
1431 			xprt->stat.connect_time += (long)jiffies -
1432 						   xprt->stat.connect_start;
1433 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1434 		}
1435 		break;
1436 	case TCP_FIN_WAIT1:
1437 		/* The client initiated a shutdown of the socket */
1438 		xprt->connect_cookie++;
1439 		xprt->reestablish_timeout = 0;
1440 		set_bit(XPRT_CLOSING, &xprt->state);
1441 		smp_mb__before_atomic();
1442 		clear_bit(XPRT_CONNECTED, &xprt->state);
1443 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1444 		smp_mb__after_atomic();
1445 		break;
1446 	case TCP_CLOSE_WAIT:
1447 		/* The server initiated a shutdown of the socket */
1448 		xprt->connect_cookie++;
1449 		clear_bit(XPRT_CONNECTED, &xprt->state);
1450 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1451 		fallthrough;
1452 	case TCP_CLOSING:
1453 		/*
1454 		 * If the server closed down the connection, make sure that
1455 		 * we back off before reconnecting
1456 		 */
1457 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1458 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1459 		break;
1460 	case TCP_LAST_ACK:
1461 		set_bit(XPRT_CLOSING, &xprt->state);
1462 		smp_mb__before_atomic();
1463 		clear_bit(XPRT_CONNECTED, &xprt->state);
1464 		smp_mb__after_atomic();
1465 		break;
1466 	case TCP_CLOSE:
1467 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1468 					&transport->sock_state))
1469 			xprt_clear_connecting(xprt);
1470 		clear_bit(XPRT_CLOSING, &xprt->state);
1471 		/* Trigger the socket release */
1472 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1473 	}
1474  out:
1475 	read_unlock_bh(&sk->sk_callback_lock);
1476 }
1477 
1478 static void xs_write_space(struct sock *sk)
1479 {
1480 	struct socket_wq *wq;
1481 	struct sock_xprt *transport;
1482 	struct rpc_xprt *xprt;
1483 
1484 	if (!sk->sk_socket)
1485 		return;
1486 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1487 
1488 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1489 		return;
1490 	transport = container_of(xprt, struct sock_xprt, xprt);
1491 	rcu_read_lock();
1492 	wq = rcu_dereference(sk->sk_wq);
1493 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1494 		goto out;
1495 
1496 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1497 	sk->sk_write_pending--;
1498 out:
1499 	rcu_read_unlock();
1500 }
1501 
1502 /**
1503  * xs_udp_write_space - callback invoked when socket buffer space
1504  *                             becomes available
1505  * @sk: socket whose state has changed
1506  *
1507  * Called when more output buffer space is available for this socket.
1508  * We try not to wake our writers until they can make "significant"
1509  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1510  * with a bunch of small requests.
1511  */
1512 static void xs_udp_write_space(struct sock *sk)
1513 {
1514 	read_lock_bh(&sk->sk_callback_lock);
1515 
1516 	/* from net/core/sock.c:sock_def_write_space */
1517 	if (sock_writeable(sk))
1518 		xs_write_space(sk);
1519 
1520 	read_unlock_bh(&sk->sk_callback_lock);
1521 }
1522 
1523 /**
1524  * xs_tcp_write_space - callback invoked when socket buffer space
1525  *                             becomes available
1526  * @sk: socket whose state has changed
1527  *
1528  * Called when more output buffer space is available for this socket.
1529  * We try not to wake our writers until they can make "significant"
1530  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1531  * with a bunch of small requests.
1532  */
1533 static void xs_tcp_write_space(struct sock *sk)
1534 {
1535 	read_lock_bh(&sk->sk_callback_lock);
1536 
1537 	/* from net/core/stream.c:sk_stream_write_space */
1538 	if (sk_stream_is_writeable(sk))
1539 		xs_write_space(sk);
1540 
1541 	read_unlock_bh(&sk->sk_callback_lock);
1542 }
1543 
1544 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1545 {
1546 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1547 	struct sock *sk = transport->inet;
1548 
1549 	if (transport->rcvsize) {
1550 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1551 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1552 	}
1553 	if (transport->sndsize) {
1554 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1555 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1556 		sk->sk_write_space(sk);
1557 	}
1558 }
1559 
1560 /**
1561  * xs_udp_set_buffer_size - set send and receive limits
1562  * @xprt: generic transport
1563  * @sndsize: requested size of send buffer, in bytes
1564  * @rcvsize: requested size of receive buffer, in bytes
1565  *
1566  * Set socket send and receive buffer size limits.
1567  */
1568 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1569 {
1570 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1571 
1572 	transport->sndsize = 0;
1573 	if (sndsize)
1574 		transport->sndsize = sndsize + 1024;
1575 	transport->rcvsize = 0;
1576 	if (rcvsize)
1577 		transport->rcvsize = rcvsize + 1024;
1578 
1579 	xs_udp_do_set_buffer_size(xprt);
1580 }
1581 
1582 /**
1583  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1584  * @xprt: controlling transport
1585  * @task: task that timed out
1586  *
1587  * Adjust the congestion window after a retransmit timeout has occurred.
1588  */
1589 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1590 {
1591 	spin_lock(&xprt->transport_lock);
1592 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1593 	spin_unlock(&xprt->transport_lock);
1594 }
1595 
1596 static int xs_get_random_port(void)
1597 {
1598 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1599 	unsigned short range;
1600 	unsigned short rand;
1601 
1602 	if (max < min)
1603 		return -EADDRINUSE;
1604 	range = max - min + 1;
1605 	rand = (unsigned short) prandom_u32() % range;
1606 	return rand + min;
1607 }
1608 
1609 static unsigned short xs_sock_getport(struct socket *sock)
1610 {
1611 	struct sockaddr_storage buf;
1612 	unsigned short port = 0;
1613 
1614 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1615 		goto out;
1616 	switch (buf.ss_family) {
1617 	case AF_INET6:
1618 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1619 		break;
1620 	case AF_INET:
1621 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1622 	}
1623 out:
1624 	return port;
1625 }
1626 
1627 /**
1628  * xs_set_port - reset the port number in the remote endpoint address
1629  * @xprt: generic transport
1630  * @port: new port number
1631  *
1632  */
1633 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1634 {
1635 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1636 
1637 	rpc_set_port(xs_addr(xprt), port);
1638 	xs_update_peer_port(xprt);
1639 }
1640 
1641 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1642 {
1643 	if (transport->srcport == 0 && transport->xprt.reuseport)
1644 		transport->srcport = xs_sock_getport(sock);
1645 }
1646 
1647 static int xs_get_srcport(struct sock_xprt *transport)
1648 {
1649 	int port = transport->srcport;
1650 
1651 	if (port == 0 && transport->xprt.resvport)
1652 		port = xs_get_random_port();
1653 	return port;
1654 }
1655 
1656 unsigned short get_srcport(struct rpc_xprt *xprt)
1657 {
1658 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1659 	return sock->srcport;
1660 }
1661 EXPORT_SYMBOL(get_srcport);
1662 
1663 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1664 {
1665 	if (transport->srcport != 0)
1666 		transport->srcport = 0;
1667 	if (!transport->xprt.resvport)
1668 		return 0;
1669 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1670 		return xprt_max_resvport;
1671 	return --port;
1672 }
1673 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1674 {
1675 	struct sockaddr_storage myaddr;
1676 	int err, nloop = 0;
1677 	int port = xs_get_srcport(transport);
1678 	unsigned short last;
1679 
1680 	/*
1681 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1682 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1683 	 * port selection happen implicitly when the socket is used
1684 	 * (for example at connect time).
1685 	 *
1686 	 * This ensures that we can continue to establish TCP
1687 	 * connections even when all local ephemeral ports are already
1688 	 * a part of some TCP connection.  This makes no difference
1689 	 * for UDP sockets, but also doesn't harm them.
1690 	 *
1691 	 * If we're asking for any reserved port (i.e. port == 0 &&
1692 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1693 	 * ensure that port is non-zero and we will bind as needed.
1694 	 */
1695 	if (port <= 0)
1696 		return port;
1697 
1698 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1699 	do {
1700 		rpc_set_port((struct sockaddr *)&myaddr, port);
1701 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1702 				transport->xprt.addrlen);
1703 		if (err == 0) {
1704 			if (transport->xprt.reuseport)
1705 				transport->srcport = port;
1706 			break;
1707 		}
1708 		last = port;
1709 		port = xs_next_srcport(transport, port);
1710 		if (port > last)
1711 			nloop++;
1712 	} while (err == -EADDRINUSE && nloop != 2);
1713 
1714 	if (myaddr.ss_family == AF_INET)
1715 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1716 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1717 				port, err ? "failed" : "ok", err);
1718 	else
1719 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1720 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1721 				port, err ? "failed" : "ok", err);
1722 	return err;
1723 }
1724 
1725 /*
1726  * We don't support autobind on AF_LOCAL sockets
1727  */
1728 static void xs_local_rpcbind(struct rpc_task *task)
1729 {
1730 	xprt_set_bound(task->tk_xprt);
1731 }
1732 
1733 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1734 {
1735 }
1736 
1737 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1738 static struct lock_class_key xs_key[2];
1739 static struct lock_class_key xs_slock_key[2];
1740 
1741 static inline void xs_reclassify_socketu(struct socket *sock)
1742 {
1743 	struct sock *sk = sock->sk;
1744 
1745 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1746 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1747 }
1748 
1749 static inline void xs_reclassify_socket4(struct socket *sock)
1750 {
1751 	struct sock *sk = sock->sk;
1752 
1753 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1754 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1755 }
1756 
1757 static inline void xs_reclassify_socket6(struct socket *sock)
1758 {
1759 	struct sock *sk = sock->sk;
1760 
1761 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1762 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1763 }
1764 
1765 static inline void xs_reclassify_socket(int family, struct socket *sock)
1766 {
1767 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1768 		return;
1769 
1770 	switch (family) {
1771 	case AF_LOCAL:
1772 		xs_reclassify_socketu(sock);
1773 		break;
1774 	case AF_INET:
1775 		xs_reclassify_socket4(sock);
1776 		break;
1777 	case AF_INET6:
1778 		xs_reclassify_socket6(sock);
1779 		break;
1780 	}
1781 }
1782 #else
1783 static inline void xs_reclassify_socket(int family, struct socket *sock)
1784 {
1785 }
1786 #endif
1787 
1788 static void xs_dummy_setup_socket(struct work_struct *work)
1789 {
1790 }
1791 
1792 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1793 		struct sock_xprt *transport, int family, int type,
1794 		int protocol, bool reuseport)
1795 {
1796 	struct file *filp;
1797 	struct socket *sock;
1798 	int err;
1799 
1800 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1801 	if (err < 0) {
1802 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1803 				protocol, -err);
1804 		goto out;
1805 	}
1806 	xs_reclassify_socket(family, sock);
1807 
1808 	if (reuseport)
1809 		sock_set_reuseport(sock->sk);
1810 
1811 	err = xs_bind(transport, sock);
1812 	if (err) {
1813 		sock_release(sock);
1814 		goto out;
1815 	}
1816 
1817 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1818 	if (IS_ERR(filp))
1819 		return ERR_CAST(filp);
1820 	transport->file = filp;
1821 
1822 	return sock;
1823 out:
1824 	return ERR_PTR(err);
1825 }
1826 
1827 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1828 				      struct socket *sock)
1829 {
1830 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1831 									xprt);
1832 
1833 	if (!transport->inet) {
1834 		struct sock *sk = sock->sk;
1835 
1836 		write_lock_bh(&sk->sk_callback_lock);
1837 
1838 		xs_save_old_callbacks(transport, sk);
1839 
1840 		sk->sk_user_data = xprt;
1841 		sk->sk_data_ready = xs_data_ready;
1842 		sk->sk_write_space = xs_udp_write_space;
1843 		sock_set_flag(sk, SOCK_FASYNC);
1844 		sk->sk_error_report = xs_error_report;
1845 
1846 		xprt_clear_connected(xprt);
1847 
1848 		/* Reset to new socket */
1849 		transport->sock = sock;
1850 		transport->inet = sk;
1851 
1852 		write_unlock_bh(&sk->sk_callback_lock);
1853 	}
1854 
1855 	xs_stream_start_connect(transport);
1856 
1857 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1858 }
1859 
1860 /**
1861  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1862  * @transport: socket transport to connect
1863  */
1864 static int xs_local_setup_socket(struct sock_xprt *transport)
1865 {
1866 	struct rpc_xprt *xprt = &transport->xprt;
1867 	struct file *filp;
1868 	struct socket *sock;
1869 	int status;
1870 
1871 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1872 					SOCK_STREAM, 0, &sock, 1);
1873 	if (status < 0) {
1874 		dprintk("RPC:       can't create AF_LOCAL "
1875 			"transport socket (%d).\n", -status);
1876 		goto out;
1877 	}
1878 	xs_reclassify_socket(AF_LOCAL, sock);
1879 
1880 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1881 	if (IS_ERR(filp)) {
1882 		status = PTR_ERR(filp);
1883 		goto out;
1884 	}
1885 	transport->file = filp;
1886 
1887 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1888 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1889 
1890 	status = xs_local_finish_connecting(xprt, sock);
1891 	trace_rpc_socket_connect(xprt, sock, status);
1892 	switch (status) {
1893 	case 0:
1894 		dprintk("RPC:       xprt %p connected to %s\n",
1895 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1896 		xprt->stat.connect_count++;
1897 		xprt->stat.connect_time += (long)jiffies -
1898 					   xprt->stat.connect_start;
1899 		xprt_set_connected(xprt);
1900 		break;
1901 	case -ENOBUFS:
1902 		break;
1903 	case -ENOENT:
1904 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1905 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1906 		break;
1907 	case -ECONNREFUSED:
1908 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1909 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1910 		break;
1911 	default:
1912 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1913 				__func__, -status,
1914 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1915 	}
1916 
1917 out:
1918 	xprt_clear_connecting(xprt);
1919 	xprt_wake_pending_tasks(xprt, status);
1920 	return status;
1921 }
1922 
1923 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1924 {
1925 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1926 	int ret;
1927 
1928 	 if (RPC_IS_ASYNC(task)) {
1929 		/*
1930 		 * We want the AF_LOCAL connect to be resolved in the
1931 		 * filesystem namespace of the process making the rpc
1932 		 * call.  Thus we connect synchronously.
1933 		 *
1934 		 * If we want to support asynchronous AF_LOCAL calls,
1935 		 * we'll need to figure out how to pass a namespace to
1936 		 * connect.
1937 		 */
1938 		task->tk_rpc_status = -ENOTCONN;
1939 		rpc_exit(task, -ENOTCONN);
1940 		return;
1941 	}
1942 	ret = xs_local_setup_socket(transport);
1943 	if (ret && !RPC_IS_SOFTCONN(task))
1944 		msleep_interruptible(15000);
1945 }
1946 
1947 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1948 /*
1949  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1950  * know that we have exclusive access to the socket), to guard against
1951  * races with xs_reset_transport.
1952  */
1953 static void xs_set_memalloc(struct rpc_xprt *xprt)
1954 {
1955 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1956 			xprt);
1957 
1958 	/*
1959 	 * If there's no sock, then we have nothing to set. The
1960 	 * reconnecting process will get it for us.
1961 	 */
1962 	if (!transport->inet)
1963 		return;
1964 	if (atomic_read(&xprt->swapper))
1965 		sk_set_memalloc(transport->inet);
1966 }
1967 
1968 /**
1969  * xs_enable_swap - Tag this transport as being used for swap.
1970  * @xprt: transport to tag
1971  *
1972  * Take a reference to this transport on behalf of the rpc_clnt, and
1973  * optionally mark it for swapping if it wasn't already.
1974  */
1975 static int
1976 xs_enable_swap(struct rpc_xprt *xprt)
1977 {
1978 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1979 
1980 	if (atomic_inc_return(&xprt->swapper) != 1)
1981 		return 0;
1982 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1983 		return -ERESTARTSYS;
1984 	if (xs->inet)
1985 		sk_set_memalloc(xs->inet);
1986 	xprt_release_xprt(xprt, NULL);
1987 	return 0;
1988 }
1989 
1990 /**
1991  * xs_disable_swap - Untag this transport as being used for swap.
1992  * @xprt: transport to tag
1993  *
1994  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1995  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1996  */
1997 static void
1998 xs_disable_swap(struct rpc_xprt *xprt)
1999 {
2000 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2001 
2002 	if (!atomic_dec_and_test(&xprt->swapper))
2003 		return;
2004 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2005 		return;
2006 	if (xs->inet)
2007 		sk_clear_memalloc(xs->inet);
2008 	xprt_release_xprt(xprt, NULL);
2009 }
2010 #else
2011 static void xs_set_memalloc(struct rpc_xprt *xprt)
2012 {
2013 }
2014 
2015 static int
2016 xs_enable_swap(struct rpc_xprt *xprt)
2017 {
2018 	return -EINVAL;
2019 }
2020 
2021 static void
2022 xs_disable_swap(struct rpc_xprt *xprt)
2023 {
2024 }
2025 #endif
2026 
2027 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2028 {
2029 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2030 
2031 	if (!transport->inet) {
2032 		struct sock *sk = sock->sk;
2033 
2034 		write_lock_bh(&sk->sk_callback_lock);
2035 
2036 		xs_save_old_callbacks(transport, sk);
2037 
2038 		sk->sk_user_data = xprt;
2039 		sk->sk_data_ready = xs_data_ready;
2040 		sk->sk_write_space = xs_udp_write_space;
2041 		sock_set_flag(sk, SOCK_FASYNC);
2042 
2043 		xprt_set_connected(xprt);
2044 
2045 		/* Reset to new socket */
2046 		transport->sock = sock;
2047 		transport->inet = sk;
2048 
2049 		xs_set_memalloc(xprt);
2050 
2051 		write_unlock_bh(&sk->sk_callback_lock);
2052 	}
2053 	xs_udp_do_set_buffer_size(xprt);
2054 
2055 	xprt->stat.connect_start = jiffies;
2056 }
2057 
2058 static void xs_udp_setup_socket(struct work_struct *work)
2059 {
2060 	struct sock_xprt *transport =
2061 		container_of(work, struct sock_xprt, connect_worker.work);
2062 	struct rpc_xprt *xprt = &transport->xprt;
2063 	struct socket *sock;
2064 	int status = -EIO;
2065 
2066 	sock = xs_create_sock(xprt, transport,
2067 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2068 			IPPROTO_UDP, false);
2069 	if (IS_ERR(sock))
2070 		goto out;
2071 
2072 	dprintk("RPC:       worker connecting xprt %p via %s to "
2073 				"%s (port %s)\n", xprt,
2074 			xprt->address_strings[RPC_DISPLAY_PROTO],
2075 			xprt->address_strings[RPC_DISPLAY_ADDR],
2076 			xprt->address_strings[RPC_DISPLAY_PORT]);
2077 
2078 	xs_udp_finish_connecting(xprt, sock);
2079 	trace_rpc_socket_connect(xprt, sock, 0);
2080 	status = 0;
2081 out:
2082 	xprt_clear_connecting(xprt);
2083 	xprt_unlock_connect(xprt, transport);
2084 	xprt_wake_pending_tasks(xprt, status);
2085 }
2086 
2087 /**
2088  * xs_tcp_shutdown - gracefully shut down a TCP socket
2089  * @xprt: transport
2090  *
2091  * Initiates a graceful shutdown of the TCP socket by calling the
2092  * equivalent of shutdown(SHUT_RDWR);
2093  */
2094 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2095 {
2096 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2097 	struct socket *sock = transport->sock;
2098 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2099 
2100 	if (sock == NULL)
2101 		return;
2102 	switch (skst) {
2103 	default:
2104 		kernel_sock_shutdown(sock, SHUT_RDWR);
2105 		trace_rpc_socket_shutdown(xprt, sock);
2106 		break;
2107 	case TCP_CLOSE:
2108 	case TCP_TIME_WAIT:
2109 		xs_reset_transport(transport);
2110 	}
2111 }
2112 
2113 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2114 		struct socket *sock)
2115 {
2116 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2117 	unsigned int keepidle;
2118 	unsigned int keepcnt;
2119 	unsigned int timeo;
2120 
2121 	spin_lock(&xprt->transport_lock);
2122 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2123 	keepcnt = xprt->timeout->to_retries + 1;
2124 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2125 		(xprt->timeout->to_retries + 1);
2126 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2127 	spin_unlock(&xprt->transport_lock);
2128 
2129 	/* TCP Keepalive options */
2130 	sock_set_keepalive(sock->sk);
2131 	tcp_sock_set_keepidle(sock->sk, keepidle);
2132 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2133 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2134 
2135 	/* TCP user timeout (see RFC5482) */
2136 	tcp_sock_set_user_timeout(sock->sk, timeo);
2137 }
2138 
2139 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2140 		unsigned long connect_timeout,
2141 		unsigned long reconnect_timeout)
2142 {
2143 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2144 	struct rpc_timeout to;
2145 	unsigned long initval;
2146 
2147 	spin_lock(&xprt->transport_lock);
2148 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2149 		xprt->max_reconnect_timeout = reconnect_timeout;
2150 	if (connect_timeout < xprt->connect_timeout) {
2151 		memcpy(&to, xprt->timeout, sizeof(to));
2152 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2153 		/* Arbitrary lower limit */
2154 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2155 			initval = XS_TCP_INIT_REEST_TO << 1;
2156 		to.to_initval = initval;
2157 		to.to_maxval = initval;
2158 		memcpy(&transport->tcp_timeout, &to,
2159 				sizeof(transport->tcp_timeout));
2160 		xprt->timeout = &transport->tcp_timeout;
2161 		xprt->connect_timeout = connect_timeout;
2162 	}
2163 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2164 	spin_unlock(&xprt->transport_lock);
2165 }
2166 
2167 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2168 {
2169 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2170 	int ret = -ENOTCONN;
2171 
2172 	if (!transport->inet) {
2173 		struct sock *sk = sock->sk;
2174 
2175 		/* Avoid temporary address, they are bad for long-lived
2176 		 * connections such as NFS mounts.
2177 		 * RFC4941, section 3.6 suggests that:
2178 		 *    Individual applications, which have specific
2179 		 *    knowledge about the normal duration of connections,
2180 		 *    MAY override this as appropriate.
2181 		 */
2182 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2183 			ip6_sock_set_addr_preferences(sk,
2184 				IPV6_PREFER_SRC_PUBLIC);
2185 		}
2186 
2187 		xs_tcp_set_socket_timeouts(xprt, sock);
2188 		tcp_sock_set_nodelay(sk);
2189 
2190 		write_lock_bh(&sk->sk_callback_lock);
2191 
2192 		xs_save_old_callbacks(transport, sk);
2193 
2194 		sk->sk_user_data = xprt;
2195 		sk->sk_data_ready = xs_data_ready;
2196 		sk->sk_state_change = xs_tcp_state_change;
2197 		sk->sk_write_space = xs_tcp_write_space;
2198 		sock_set_flag(sk, SOCK_FASYNC);
2199 		sk->sk_error_report = xs_error_report;
2200 
2201 		/* socket options */
2202 		sock_reset_flag(sk, SOCK_LINGER);
2203 
2204 		xprt_clear_connected(xprt);
2205 
2206 		/* Reset to new socket */
2207 		transport->sock = sock;
2208 		transport->inet = sk;
2209 
2210 		write_unlock_bh(&sk->sk_callback_lock);
2211 	}
2212 
2213 	if (!xprt_bound(xprt))
2214 		goto out;
2215 
2216 	xs_set_memalloc(xprt);
2217 
2218 	xs_stream_start_connect(transport);
2219 
2220 	/* Tell the socket layer to start connecting... */
2221 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2222 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2223 	switch (ret) {
2224 	case 0:
2225 		xs_set_srcport(transport, sock);
2226 		fallthrough;
2227 	case -EINPROGRESS:
2228 		/* SYN_SENT! */
2229 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2230 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2231 		break;
2232 	case -EADDRNOTAVAIL:
2233 		/* Source port number is unavailable. Try a new one! */
2234 		transport->srcport = 0;
2235 	}
2236 out:
2237 	return ret;
2238 }
2239 
2240 /**
2241  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2242  * @work: queued work item
2243  *
2244  * Invoked by a work queue tasklet.
2245  */
2246 static void xs_tcp_setup_socket(struct work_struct *work)
2247 {
2248 	struct sock_xprt *transport =
2249 		container_of(work, struct sock_xprt, connect_worker.work);
2250 	struct socket *sock = transport->sock;
2251 	struct rpc_xprt *xprt = &transport->xprt;
2252 	int status = -EIO;
2253 
2254 	if (!sock) {
2255 		sock = xs_create_sock(xprt, transport,
2256 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2257 				IPPROTO_TCP, true);
2258 		if (IS_ERR(sock)) {
2259 			status = PTR_ERR(sock);
2260 			goto out;
2261 		}
2262 	}
2263 
2264 	dprintk("RPC:       worker connecting xprt %p via %s to "
2265 				"%s (port %s)\n", xprt,
2266 			xprt->address_strings[RPC_DISPLAY_PROTO],
2267 			xprt->address_strings[RPC_DISPLAY_ADDR],
2268 			xprt->address_strings[RPC_DISPLAY_PORT]);
2269 
2270 	status = xs_tcp_finish_connecting(xprt, sock);
2271 	trace_rpc_socket_connect(xprt, sock, status);
2272 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2273 			xprt, -status, xprt_connected(xprt),
2274 			sock->sk->sk_state);
2275 	switch (status) {
2276 	default:
2277 		printk("%s: connect returned unhandled error %d\n",
2278 			__func__, status);
2279 		fallthrough;
2280 	case -EADDRNOTAVAIL:
2281 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2282 		 * and retry
2283 		 */
2284 		xs_tcp_force_close(xprt);
2285 		break;
2286 	case 0:
2287 	case -EINPROGRESS:
2288 	case -EALREADY:
2289 		xprt_unlock_connect(xprt, transport);
2290 		return;
2291 	case -EINVAL:
2292 		/* Happens, for instance, if the user specified a link
2293 		 * local IPv6 address without a scope-id.
2294 		 */
2295 	case -ECONNREFUSED:
2296 	case -ECONNRESET:
2297 	case -ENETDOWN:
2298 	case -ENETUNREACH:
2299 	case -EHOSTUNREACH:
2300 	case -EADDRINUSE:
2301 	case -ENOBUFS:
2302 		/* xs_tcp_force_close() wakes tasks with a fixed error code.
2303 		 * We need to wake them first to ensure the correct error code.
2304 		 */
2305 		xprt_wake_pending_tasks(xprt, status);
2306 		xs_tcp_force_close(xprt);
2307 		goto out;
2308 	}
2309 	status = -EAGAIN;
2310 out:
2311 	xprt_clear_connecting(xprt);
2312 	xprt_unlock_connect(xprt, transport);
2313 	xprt_wake_pending_tasks(xprt, status);
2314 }
2315 
2316 /**
2317  * xs_connect - connect a socket to a remote endpoint
2318  * @xprt: pointer to transport structure
2319  * @task: address of RPC task that manages state of connect request
2320  *
2321  * TCP: If the remote end dropped the connection, delay reconnecting.
2322  *
2323  * UDP socket connects are synchronous, but we use a work queue anyway
2324  * to guarantee that even unprivileged user processes can set up a
2325  * socket on a privileged port.
2326  *
2327  * If a UDP socket connect fails, the delay behavior here prevents
2328  * retry floods (hard mounts).
2329  */
2330 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2331 {
2332 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2333 	unsigned long delay = 0;
2334 
2335 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2336 
2337 	if (transport->sock != NULL) {
2338 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2339 				"seconds\n",
2340 				xprt, xprt->reestablish_timeout / HZ);
2341 
2342 		/* Start by resetting any existing state */
2343 		xs_reset_transport(transport);
2344 
2345 		delay = xprt_reconnect_delay(xprt);
2346 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2347 
2348 	} else
2349 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2350 
2351 	queue_delayed_work(xprtiod_workqueue,
2352 			&transport->connect_worker,
2353 			delay);
2354 }
2355 
2356 static void xs_wake_disconnect(struct sock_xprt *transport)
2357 {
2358 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2359 		xs_tcp_force_close(&transport->xprt);
2360 }
2361 
2362 static void xs_wake_write(struct sock_xprt *transport)
2363 {
2364 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2365 		xprt_write_space(&transport->xprt);
2366 }
2367 
2368 static void xs_wake_error(struct sock_xprt *transport)
2369 {
2370 	int sockerr;
2371 
2372 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2373 		return;
2374 	mutex_lock(&transport->recv_mutex);
2375 	if (transport->sock == NULL)
2376 		goto out;
2377 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2378 		goto out;
2379 	sockerr = xchg(&transport->xprt_err, 0);
2380 	if (sockerr < 0)
2381 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2382 out:
2383 	mutex_unlock(&transport->recv_mutex);
2384 }
2385 
2386 static void xs_wake_pending(struct sock_xprt *transport)
2387 {
2388 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2389 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2390 }
2391 
2392 static void xs_error_handle(struct work_struct *work)
2393 {
2394 	struct sock_xprt *transport = container_of(work,
2395 			struct sock_xprt, error_worker);
2396 
2397 	xs_wake_disconnect(transport);
2398 	xs_wake_write(transport);
2399 	xs_wake_error(transport);
2400 	xs_wake_pending(transport);
2401 }
2402 
2403 /**
2404  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2405  * @xprt: rpc_xprt struct containing statistics
2406  * @seq: output file
2407  *
2408  */
2409 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2410 {
2411 	long idle_time = 0;
2412 
2413 	if (xprt_connected(xprt))
2414 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2415 
2416 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2417 			"%llu %llu %lu %llu %llu\n",
2418 			xprt->stat.bind_count,
2419 			xprt->stat.connect_count,
2420 			xprt->stat.connect_time / HZ,
2421 			idle_time,
2422 			xprt->stat.sends,
2423 			xprt->stat.recvs,
2424 			xprt->stat.bad_xids,
2425 			xprt->stat.req_u,
2426 			xprt->stat.bklog_u,
2427 			xprt->stat.max_slots,
2428 			xprt->stat.sending_u,
2429 			xprt->stat.pending_u);
2430 }
2431 
2432 /**
2433  * xs_udp_print_stats - display UDP socket-specific stats
2434  * @xprt: rpc_xprt struct containing statistics
2435  * @seq: output file
2436  *
2437  */
2438 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2439 {
2440 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2441 
2442 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2443 			"%lu %llu %llu\n",
2444 			transport->srcport,
2445 			xprt->stat.bind_count,
2446 			xprt->stat.sends,
2447 			xprt->stat.recvs,
2448 			xprt->stat.bad_xids,
2449 			xprt->stat.req_u,
2450 			xprt->stat.bklog_u,
2451 			xprt->stat.max_slots,
2452 			xprt->stat.sending_u,
2453 			xprt->stat.pending_u);
2454 }
2455 
2456 /**
2457  * xs_tcp_print_stats - display TCP socket-specific stats
2458  * @xprt: rpc_xprt struct containing statistics
2459  * @seq: output file
2460  *
2461  */
2462 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2463 {
2464 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2465 	long idle_time = 0;
2466 
2467 	if (xprt_connected(xprt))
2468 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2469 
2470 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2471 			"%llu %llu %lu %llu %llu\n",
2472 			transport->srcport,
2473 			xprt->stat.bind_count,
2474 			xprt->stat.connect_count,
2475 			xprt->stat.connect_time / HZ,
2476 			idle_time,
2477 			xprt->stat.sends,
2478 			xprt->stat.recvs,
2479 			xprt->stat.bad_xids,
2480 			xprt->stat.req_u,
2481 			xprt->stat.bklog_u,
2482 			xprt->stat.max_slots,
2483 			xprt->stat.sending_u,
2484 			xprt->stat.pending_u);
2485 }
2486 
2487 /*
2488  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2489  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2490  * to use the server side send routines.
2491  */
2492 static int bc_malloc(struct rpc_task *task)
2493 {
2494 	struct rpc_rqst *rqst = task->tk_rqstp;
2495 	size_t size = rqst->rq_callsize;
2496 	struct page *page;
2497 	struct rpc_buffer *buf;
2498 
2499 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2500 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2501 			  size);
2502 		return -EINVAL;
2503 	}
2504 
2505 	page = alloc_page(GFP_KERNEL);
2506 	if (!page)
2507 		return -ENOMEM;
2508 
2509 	buf = page_address(page);
2510 	buf->len = PAGE_SIZE;
2511 
2512 	rqst->rq_buffer = buf->data;
2513 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2514 	return 0;
2515 }
2516 
2517 /*
2518  * Free the space allocated in the bc_alloc routine
2519  */
2520 static void bc_free(struct rpc_task *task)
2521 {
2522 	void *buffer = task->tk_rqstp->rq_buffer;
2523 	struct rpc_buffer *buf;
2524 
2525 	buf = container_of(buffer, struct rpc_buffer, data);
2526 	free_page((unsigned long)buf);
2527 }
2528 
2529 static int bc_sendto(struct rpc_rqst *req)
2530 {
2531 	struct xdr_buf *xdr = &req->rq_snd_buf;
2532 	struct sock_xprt *transport =
2533 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2534 	struct msghdr msg = {
2535 		.msg_flags	= 0,
2536 	};
2537 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2538 					 (u32)xdr->len);
2539 	unsigned int sent = 0;
2540 	int err;
2541 
2542 	req->rq_xtime = ktime_get();
2543 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2544 	xdr_free_bvec(xdr);
2545 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2546 		return -EAGAIN;
2547 	return sent;
2548 }
2549 
2550 /**
2551  * bc_send_request - Send a backchannel Call on a TCP socket
2552  * @req: rpc_rqst containing Call message to be sent
2553  *
2554  * xpt_mutex ensures @rqstp's whole message is written to the socket
2555  * without interruption.
2556  *
2557  * Return values:
2558  *   %0 if the message was sent successfully
2559  *   %ENOTCONN if the message was not sent
2560  */
2561 static int bc_send_request(struct rpc_rqst *req)
2562 {
2563 	struct svc_xprt	*xprt;
2564 	int len;
2565 
2566 	/*
2567 	 * Get the server socket associated with this callback xprt
2568 	 */
2569 	xprt = req->rq_xprt->bc_xprt;
2570 
2571 	/*
2572 	 * Grab the mutex to serialize data as the connection is shared
2573 	 * with the fore channel
2574 	 */
2575 	mutex_lock(&xprt->xpt_mutex);
2576 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2577 		len = -ENOTCONN;
2578 	else
2579 		len = bc_sendto(req);
2580 	mutex_unlock(&xprt->xpt_mutex);
2581 
2582 	if (len > 0)
2583 		len = 0;
2584 
2585 	return len;
2586 }
2587 
2588 /*
2589  * The close routine. Since this is client initiated, we do nothing
2590  */
2591 
2592 static void bc_close(struct rpc_xprt *xprt)
2593 {
2594 	xprt_disconnect_done(xprt);
2595 }
2596 
2597 /*
2598  * The xprt destroy routine. Again, because this connection is client
2599  * initiated, we do nothing
2600  */
2601 
2602 static void bc_destroy(struct rpc_xprt *xprt)
2603 {
2604 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2605 
2606 	xs_xprt_free(xprt);
2607 	module_put(THIS_MODULE);
2608 }
2609 
2610 static const struct rpc_xprt_ops xs_local_ops = {
2611 	.reserve_xprt		= xprt_reserve_xprt,
2612 	.release_xprt		= xprt_release_xprt,
2613 	.alloc_slot		= xprt_alloc_slot,
2614 	.free_slot		= xprt_free_slot,
2615 	.rpcbind		= xs_local_rpcbind,
2616 	.set_port		= xs_local_set_port,
2617 	.connect		= xs_local_connect,
2618 	.buf_alloc		= rpc_malloc,
2619 	.buf_free		= rpc_free,
2620 	.prepare_request	= xs_stream_prepare_request,
2621 	.send_request		= xs_local_send_request,
2622 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2623 	.close			= xs_close,
2624 	.destroy		= xs_destroy,
2625 	.print_stats		= xs_local_print_stats,
2626 	.enable_swap		= xs_enable_swap,
2627 	.disable_swap		= xs_disable_swap,
2628 };
2629 
2630 static const struct rpc_xprt_ops xs_udp_ops = {
2631 	.set_buffer_size	= xs_udp_set_buffer_size,
2632 	.reserve_xprt		= xprt_reserve_xprt_cong,
2633 	.release_xprt		= xprt_release_xprt_cong,
2634 	.alloc_slot		= xprt_alloc_slot,
2635 	.free_slot		= xprt_free_slot,
2636 	.rpcbind		= rpcb_getport_async,
2637 	.set_port		= xs_set_port,
2638 	.connect		= xs_connect,
2639 	.buf_alloc		= rpc_malloc,
2640 	.buf_free		= rpc_free,
2641 	.send_request		= xs_udp_send_request,
2642 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2643 	.timer			= xs_udp_timer,
2644 	.release_request	= xprt_release_rqst_cong,
2645 	.close			= xs_close,
2646 	.destroy		= xs_destroy,
2647 	.print_stats		= xs_udp_print_stats,
2648 	.enable_swap		= xs_enable_swap,
2649 	.disable_swap		= xs_disable_swap,
2650 	.inject_disconnect	= xs_inject_disconnect,
2651 };
2652 
2653 static const struct rpc_xprt_ops xs_tcp_ops = {
2654 	.reserve_xprt		= xprt_reserve_xprt,
2655 	.release_xprt		= xprt_release_xprt,
2656 	.alloc_slot		= xprt_alloc_slot,
2657 	.free_slot		= xprt_free_slot,
2658 	.rpcbind		= rpcb_getport_async,
2659 	.set_port		= xs_set_port,
2660 	.connect		= xs_connect,
2661 	.buf_alloc		= rpc_malloc,
2662 	.buf_free		= rpc_free,
2663 	.prepare_request	= xs_stream_prepare_request,
2664 	.send_request		= xs_tcp_send_request,
2665 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2666 	.close			= xs_tcp_shutdown,
2667 	.destroy		= xs_destroy,
2668 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2669 	.print_stats		= xs_tcp_print_stats,
2670 	.enable_swap		= xs_enable_swap,
2671 	.disable_swap		= xs_disable_swap,
2672 	.inject_disconnect	= xs_inject_disconnect,
2673 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2674 	.bc_setup		= xprt_setup_bc,
2675 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2676 	.bc_num_slots		= xprt_bc_max_slots,
2677 	.bc_free_rqst		= xprt_free_bc_rqst,
2678 	.bc_destroy		= xprt_destroy_bc,
2679 #endif
2680 };
2681 
2682 /*
2683  * The rpc_xprt_ops for the server backchannel
2684  */
2685 
2686 static const struct rpc_xprt_ops bc_tcp_ops = {
2687 	.reserve_xprt		= xprt_reserve_xprt,
2688 	.release_xprt		= xprt_release_xprt,
2689 	.alloc_slot		= xprt_alloc_slot,
2690 	.free_slot		= xprt_free_slot,
2691 	.buf_alloc		= bc_malloc,
2692 	.buf_free		= bc_free,
2693 	.send_request		= bc_send_request,
2694 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2695 	.close			= bc_close,
2696 	.destroy		= bc_destroy,
2697 	.print_stats		= xs_tcp_print_stats,
2698 	.enable_swap		= xs_enable_swap,
2699 	.disable_swap		= xs_disable_swap,
2700 	.inject_disconnect	= xs_inject_disconnect,
2701 };
2702 
2703 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2704 {
2705 	static const struct sockaddr_in sin = {
2706 		.sin_family		= AF_INET,
2707 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2708 	};
2709 	static const struct sockaddr_in6 sin6 = {
2710 		.sin6_family		= AF_INET6,
2711 		.sin6_addr		= IN6ADDR_ANY_INIT,
2712 	};
2713 
2714 	switch (family) {
2715 	case AF_LOCAL:
2716 		break;
2717 	case AF_INET:
2718 		memcpy(sap, &sin, sizeof(sin));
2719 		break;
2720 	case AF_INET6:
2721 		memcpy(sap, &sin6, sizeof(sin6));
2722 		break;
2723 	default:
2724 		dprintk("RPC:       %s: Bad address family\n", __func__);
2725 		return -EAFNOSUPPORT;
2726 	}
2727 	return 0;
2728 }
2729 
2730 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2731 				      unsigned int slot_table_size,
2732 				      unsigned int max_slot_table_size)
2733 {
2734 	struct rpc_xprt *xprt;
2735 	struct sock_xprt *new;
2736 
2737 	if (args->addrlen > sizeof(xprt->addr)) {
2738 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2739 		return ERR_PTR(-EBADF);
2740 	}
2741 
2742 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2743 			max_slot_table_size);
2744 	if (xprt == NULL) {
2745 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2746 				"rpc_xprt\n");
2747 		return ERR_PTR(-ENOMEM);
2748 	}
2749 
2750 	new = container_of(xprt, struct sock_xprt, xprt);
2751 	mutex_init(&new->recv_mutex);
2752 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2753 	xprt->addrlen = args->addrlen;
2754 	if (args->srcaddr)
2755 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2756 	else {
2757 		int err;
2758 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2759 					(struct sockaddr *)&new->srcaddr);
2760 		if (err != 0) {
2761 			xprt_free(xprt);
2762 			return ERR_PTR(err);
2763 		}
2764 	}
2765 
2766 	return xprt;
2767 }
2768 
2769 static const struct rpc_timeout xs_local_default_timeout = {
2770 	.to_initval = 10 * HZ,
2771 	.to_maxval = 10 * HZ,
2772 	.to_retries = 2,
2773 };
2774 
2775 /**
2776  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2777  * @args: rpc transport creation arguments
2778  *
2779  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2780  */
2781 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2782 {
2783 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2784 	struct sock_xprt *transport;
2785 	struct rpc_xprt *xprt;
2786 	struct rpc_xprt *ret;
2787 
2788 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2789 			xprt_max_tcp_slot_table_entries);
2790 	if (IS_ERR(xprt))
2791 		return xprt;
2792 	transport = container_of(xprt, struct sock_xprt, xprt);
2793 
2794 	xprt->prot = 0;
2795 	xprt->xprt_class = &xs_local_transport;
2796 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2797 
2798 	xprt->bind_timeout = XS_BIND_TO;
2799 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2800 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2801 
2802 	xprt->ops = &xs_local_ops;
2803 	xprt->timeout = &xs_local_default_timeout;
2804 
2805 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2806 	INIT_WORK(&transport->error_worker, xs_error_handle);
2807 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2808 
2809 	switch (sun->sun_family) {
2810 	case AF_LOCAL:
2811 		if (sun->sun_path[0] != '/') {
2812 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2813 					sun->sun_path);
2814 			ret = ERR_PTR(-EINVAL);
2815 			goto out_err;
2816 		}
2817 		xprt_set_bound(xprt);
2818 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2819 		ret = ERR_PTR(xs_local_setup_socket(transport));
2820 		if (ret)
2821 			goto out_err;
2822 		break;
2823 	default:
2824 		ret = ERR_PTR(-EAFNOSUPPORT);
2825 		goto out_err;
2826 	}
2827 
2828 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2829 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2830 
2831 	if (try_module_get(THIS_MODULE))
2832 		return xprt;
2833 	ret = ERR_PTR(-EINVAL);
2834 out_err:
2835 	xs_xprt_free(xprt);
2836 	return ret;
2837 }
2838 
2839 static const struct rpc_timeout xs_udp_default_timeout = {
2840 	.to_initval = 5 * HZ,
2841 	.to_maxval = 30 * HZ,
2842 	.to_increment = 5 * HZ,
2843 	.to_retries = 5,
2844 };
2845 
2846 /**
2847  * xs_setup_udp - Set up transport to use a UDP socket
2848  * @args: rpc transport creation arguments
2849  *
2850  */
2851 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2852 {
2853 	struct sockaddr *addr = args->dstaddr;
2854 	struct rpc_xprt *xprt;
2855 	struct sock_xprt *transport;
2856 	struct rpc_xprt *ret;
2857 
2858 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2859 			xprt_udp_slot_table_entries);
2860 	if (IS_ERR(xprt))
2861 		return xprt;
2862 	transport = container_of(xprt, struct sock_xprt, xprt);
2863 
2864 	xprt->prot = IPPROTO_UDP;
2865 	xprt->xprt_class = &xs_udp_transport;
2866 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2867 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2868 
2869 	xprt->bind_timeout = XS_BIND_TO;
2870 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2871 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2872 
2873 	xprt->ops = &xs_udp_ops;
2874 
2875 	xprt->timeout = &xs_udp_default_timeout;
2876 
2877 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2878 	INIT_WORK(&transport->error_worker, xs_error_handle);
2879 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2880 
2881 	switch (addr->sa_family) {
2882 	case AF_INET:
2883 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2884 			xprt_set_bound(xprt);
2885 
2886 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2887 		break;
2888 	case AF_INET6:
2889 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2890 			xprt_set_bound(xprt);
2891 
2892 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2893 		break;
2894 	default:
2895 		ret = ERR_PTR(-EAFNOSUPPORT);
2896 		goto out_err;
2897 	}
2898 
2899 	if (xprt_bound(xprt))
2900 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2901 				xprt->address_strings[RPC_DISPLAY_ADDR],
2902 				xprt->address_strings[RPC_DISPLAY_PORT],
2903 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2904 	else
2905 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2906 				xprt->address_strings[RPC_DISPLAY_ADDR],
2907 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2908 
2909 	if (try_module_get(THIS_MODULE))
2910 		return xprt;
2911 	ret = ERR_PTR(-EINVAL);
2912 out_err:
2913 	xs_xprt_free(xprt);
2914 	return ret;
2915 }
2916 
2917 static const struct rpc_timeout xs_tcp_default_timeout = {
2918 	.to_initval = 60 * HZ,
2919 	.to_maxval = 60 * HZ,
2920 	.to_retries = 2,
2921 };
2922 
2923 /**
2924  * xs_setup_tcp - Set up transport to use a TCP socket
2925  * @args: rpc transport creation arguments
2926  *
2927  */
2928 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2929 {
2930 	struct sockaddr *addr = args->dstaddr;
2931 	struct rpc_xprt *xprt;
2932 	struct sock_xprt *transport;
2933 	struct rpc_xprt *ret;
2934 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2935 
2936 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2937 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2938 
2939 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2940 			max_slot_table_size);
2941 	if (IS_ERR(xprt))
2942 		return xprt;
2943 	transport = container_of(xprt, struct sock_xprt, xprt);
2944 
2945 	xprt->prot = IPPROTO_TCP;
2946 	xprt->xprt_class = &xs_tcp_transport;
2947 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2948 
2949 	xprt->bind_timeout = XS_BIND_TO;
2950 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2951 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2952 
2953 	xprt->ops = &xs_tcp_ops;
2954 	xprt->timeout = &xs_tcp_default_timeout;
2955 
2956 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2957 	xprt->connect_timeout = xprt->timeout->to_initval *
2958 		(xprt->timeout->to_retries + 1);
2959 
2960 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2961 	INIT_WORK(&transport->error_worker, xs_error_handle);
2962 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2963 
2964 	switch (addr->sa_family) {
2965 	case AF_INET:
2966 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2967 			xprt_set_bound(xprt);
2968 
2969 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2970 		break;
2971 	case AF_INET6:
2972 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2973 			xprt_set_bound(xprt);
2974 
2975 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2976 		break;
2977 	default:
2978 		ret = ERR_PTR(-EAFNOSUPPORT);
2979 		goto out_err;
2980 	}
2981 
2982 	if (xprt_bound(xprt))
2983 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2984 				xprt->address_strings[RPC_DISPLAY_ADDR],
2985 				xprt->address_strings[RPC_DISPLAY_PORT],
2986 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2987 	else
2988 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2989 				xprt->address_strings[RPC_DISPLAY_ADDR],
2990 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2991 
2992 	if (try_module_get(THIS_MODULE))
2993 		return xprt;
2994 	ret = ERR_PTR(-EINVAL);
2995 out_err:
2996 	xs_xprt_free(xprt);
2997 	return ret;
2998 }
2999 
3000 /**
3001  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3002  * @args: rpc transport creation arguments
3003  *
3004  */
3005 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3006 {
3007 	struct sockaddr *addr = args->dstaddr;
3008 	struct rpc_xprt *xprt;
3009 	struct sock_xprt *transport;
3010 	struct svc_sock *bc_sock;
3011 	struct rpc_xprt *ret;
3012 
3013 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3014 			xprt_tcp_slot_table_entries);
3015 	if (IS_ERR(xprt))
3016 		return xprt;
3017 	transport = container_of(xprt, struct sock_xprt, xprt);
3018 
3019 	xprt->prot = IPPROTO_TCP;
3020 	xprt->xprt_class = &xs_bc_tcp_transport;
3021 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3022 	xprt->timeout = &xs_tcp_default_timeout;
3023 
3024 	/* backchannel */
3025 	xprt_set_bound(xprt);
3026 	xprt->bind_timeout = 0;
3027 	xprt->reestablish_timeout = 0;
3028 	xprt->idle_timeout = 0;
3029 
3030 	xprt->ops = &bc_tcp_ops;
3031 
3032 	switch (addr->sa_family) {
3033 	case AF_INET:
3034 		xs_format_peer_addresses(xprt, "tcp",
3035 					 RPCBIND_NETID_TCP);
3036 		break;
3037 	case AF_INET6:
3038 		xs_format_peer_addresses(xprt, "tcp",
3039 				   RPCBIND_NETID_TCP6);
3040 		break;
3041 	default:
3042 		ret = ERR_PTR(-EAFNOSUPPORT);
3043 		goto out_err;
3044 	}
3045 
3046 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3047 			xprt->address_strings[RPC_DISPLAY_ADDR],
3048 			xprt->address_strings[RPC_DISPLAY_PORT],
3049 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3050 
3051 	/*
3052 	 * Once we've associated a backchannel xprt with a connection,
3053 	 * we want to keep it around as long as the connection lasts,
3054 	 * in case we need to start using it for a backchannel again;
3055 	 * this reference won't be dropped until bc_xprt is destroyed.
3056 	 */
3057 	xprt_get(xprt);
3058 	args->bc_xprt->xpt_bc_xprt = xprt;
3059 	xprt->bc_xprt = args->bc_xprt;
3060 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3061 	transport->sock = bc_sock->sk_sock;
3062 	transport->inet = bc_sock->sk_sk;
3063 
3064 	/*
3065 	 * Since we don't want connections for the backchannel, we set
3066 	 * the xprt status to connected
3067 	 */
3068 	xprt_set_connected(xprt);
3069 
3070 	if (try_module_get(THIS_MODULE))
3071 		return xprt;
3072 
3073 	args->bc_xprt->xpt_bc_xprt = NULL;
3074 	args->bc_xprt->xpt_bc_xps = NULL;
3075 	xprt_put(xprt);
3076 	ret = ERR_PTR(-EINVAL);
3077 out_err:
3078 	xs_xprt_free(xprt);
3079 	return ret;
3080 }
3081 
3082 static struct xprt_class	xs_local_transport = {
3083 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3084 	.name		= "named UNIX socket",
3085 	.owner		= THIS_MODULE,
3086 	.ident		= XPRT_TRANSPORT_LOCAL,
3087 	.setup		= xs_setup_local,
3088 	.netid		= { "" },
3089 };
3090 
3091 static struct xprt_class	xs_udp_transport = {
3092 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3093 	.name		= "udp",
3094 	.owner		= THIS_MODULE,
3095 	.ident		= XPRT_TRANSPORT_UDP,
3096 	.setup		= xs_setup_udp,
3097 	.netid		= { "udp", "udp6", "" },
3098 };
3099 
3100 static struct xprt_class	xs_tcp_transport = {
3101 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3102 	.name		= "tcp",
3103 	.owner		= THIS_MODULE,
3104 	.ident		= XPRT_TRANSPORT_TCP,
3105 	.setup		= xs_setup_tcp,
3106 	.netid		= { "tcp", "tcp6", "" },
3107 };
3108 
3109 static struct xprt_class	xs_bc_tcp_transport = {
3110 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3111 	.name		= "tcp NFSv4.1 backchannel",
3112 	.owner		= THIS_MODULE,
3113 	.ident		= XPRT_TRANSPORT_BC_TCP,
3114 	.setup		= xs_setup_bc_tcp,
3115 	.netid		= { "" },
3116 };
3117 
3118 /**
3119  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3120  *
3121  */
3122 int init_socket_xprt(void)
3123 {
3124 	if (!sunrpc_table_header)
3125 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3126 
3127 	xprt_register_transport(&xs_local_transport);
3128 	xprt_register_transport(&xs_udp_transport);
3129 	xprt_register_transport(&xs_tcp_transport);
3130 	xprt_register_transport(&xs_bc_tcp_transport);
3131 
3132 	return 0;
3133 }
3134 
3135 /**
3136  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3137  *
3138  */
3139 void cleanup_socket_xprt(void)
3140 {
3141 	if (sunrpc_table_header) {
3142 		unregister_sysctl_table(sunrpc_table_header);
3143 		sunrpc_table_header = NULL;
3144 	}
3145 
3146 	xprt_unregister_transport(&xs_local_transport);
3147 	xprt_unregister_transport(&xs_udp_transport);
3148 	xprt_unregister_transport(&xs_tcp_transport);
3149 	xprt_unregister_transport(&xs_bc_tcp_transport);
3150 }
3151 
3152 static int param_set_uint_minmax(const char *val,
3153 		const struct kernel_param *kp,
3154 		unsigned int min, unsigned int max)
3155 {
3156 	unsigned int num;
3157 	int ret;
3158 
3159 	if (!val)
3160 		return -EINVAL;
3161 	ret = kstrtouint(val, 0, &num);
3162 	if (ret)
3163 		return ret;
3164 	if (num < min || num > max)
3165 		return -EINVAL;
3166 	*((unsigned int *)kp->arg) = num;
3167 	return 0;
3168 }
3169 
3170 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3171 {
3172 	return param_set_uint_minmax(val, kp,
3173 			RPC_MIN_RESVPORT,
3174 			RPC_MAX_RESVPORT);
3175 }
3176 
3177 static const struct kernel_param_ops param_ops_portnr = {
3178 	.set = param_set_portnr,
3179 	.get = param_get_uint,
3180 };
3181 
3182 #define param_check_portnr(name, p) \
3183 	__param_check(name, p, unsigned int);
3184 
3185 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3186 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3187 
3188 static int param_set_slot_table_size(const char *val,
3189 				     const struct kernel_param *kp)
3190 {
3191 	return param_set_uint_minmax(val, kp,
3192 			RPC_MIN_SLOT_TABLE,
3193 			RPC_MAX_SLOT_TABLE);
3194 }
3195 
3196 static const struct kernel_param_ops param_ops_slot_table_size = {
3197 	.set = param_set_slot_table_size,
3198 	.get = param_get_uint,
3199 };
3200 
3201 #define param_check_slot_table_size(name, p) \
3202 	__param_check(name, p, unsigned int);
3203 
3204 static int param_set_max_slot_table_size(const char *val,
3205 				     const struct kernel_param *kp)
3206 {
3207 	return param_set_uint_minmax(val, kp,
3208 			RPC_MIN_SLOT_TABLE,
3209 			RPC_MAX_SLOT_TABLE_LIMIT);
3210 }
3211 
3212 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3213 	.set = param_set_max_slot_table_size,
3214 	.get = param_get_uint,
3215 };
3216 
3217 #define param_check_max_slot_table_size(name, p) \
3218 	__param_check(name, p, unsigned int);
3219 
3220 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3221 		   slot_table_size, 0644);
3222 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3223 		   max_slot_table_size, 0644);
3224 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3225 		   slot_table_size, 0644);
3226