xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 7496b59f588dd52886fdbac7633608097543a0a5)
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_set_srcport(struct sock_xprt *transport, struct socket *sock);
62 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
63 		struct socket *sock);
64 
65 /*
66  * xprtsock tunables
67  */
68 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
69 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
70 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
71 
72 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
73 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
74 
75 #define XS_TCP_LINGER_TO	(15U * HZ)
76 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
77 
78 /*
79  * We can register our own files under /proc/sys/sunrpc by
80  * calling register_sysctl_table() again.  The files in that
81  * directory become the union of all files registered there.
82  *
83  * We simply need to make sure that we don't collide with
84  * someone else's file names!
85  */
86 
87 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
88 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
89 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
90 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
91 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
92 
93 static struct ctl_table_header *sunrpc_table_header;
94 
95 static struct xprt_class xs_local_transport;
96 static struct xprt_class xs_udp_transport;
97 static struct xprt_class xs_tcp_transport;
98 static struct xprt_class xs_bc_tcp_transport;
99 
100 /*
101  * FIXME: changing the UDP slot table size should also resize the UDP
102  *        socket buffers for existing UDP transports
103  */
104 static struct ctl_table xs_tunables_table[] = {
105 	{
106 		.procname	= "udp_slot_table_entries",
107 		.data		= &xprt_udp_slot_table_entries,
108 		.maxlen		= sizeof(unsigned int),
109 		.mode		= 0644,
110 		.proc_handler	= proc_dointvec_minmax,
111 		.extra1		= &min_slot_table_size,
112 		.extra2		= &max_slot_table_size
113 	},
114 	{
115 		.procname	= "tcp_slot_table_entries",
116 		.data		= &xprt_tcp_slot_table_entries,
117 		.maxlen		= sizeof(unsigned int),
118 		.mode		= 0644,
119 		.proc_handler	= proc_dointvec_minmax,
120 		.extra1		= &min_slot_table_size,
121 		.extra2		= &max_slot_table_size
122 	},
123 	{
124 		.procname	= "tcp_max_slot_table_entries",
125 		.data		= &xprt_max_tcp_slot_table_entries,
126 		.maxlen		= sizeof(unsigned int),
127 		.mode		= 0644,
128 		.proc_handler	= proc_dointvec_minmax,
129 		.extra1		= &min_slot_table_size,
130 		.extra2		= &max_tcp_slot_table_limit
131 	},
132 	{
133 		.procname	= "min_resvport",
134 		.data		= &xprt_min_resvport,
135 		.maxlen		= sizeof(unsigned int),
136 		.mode		= 0644,
137 		.proc_handler	= proc_dointvec_minmax,
138 		.extra1		= &xprt_min_resvport_limit,
139 		.extra2		= &xprt_max_resvport_limit
140 	},
141 	{
142 		.procname	= "max_resvport",
143 		.data		= &xprt_max_resvport,
144 		.maxlen		= sizeof(unsigned int),
145 		.mode		= 0644,
146 		.proc_handler	= proc_dointvec_minmax,
147 		.extra1		= &xprt_min_resvport_limit,
148 		.extra2		= &xprt_max_resvport_limit
149 	},
150 	{
151 		.procname	= "tcp_fin_timeout",
152 		.data		= &xs_tcp_fin_timeout,
153 		.maxlen		= sizeof(xs_tcp_fin_timeout),
154 		.mode		= 0644,
155 		.proc_handler	= proc_dointvec_jiffies,
156 	},
157 	{ },
158 };
159 
160 static struct ctl_table sunrpc_table[] = {
161 	{
162 		.procname	= "sunrpc",
163 		.mode		= 0555,
164 		.child		= xs_tunables_table
165 	},
166 	{ },
167 };
168 
169 /*
170  * Wait duration for a reply from the RPC portmapper.
171  */
172 #define XS_BIND_TO		(60U * HZ)
173 
174 /*
175  * Delay if a UDP socket connect error occurs.  This is most likely some
176  * kind of resource problem on the local host.
177  */
178 #define XS_UDP_REEST_TO		(2U * HZ)
179 
180 /*
181  * The reestablish timeout allows clients to delay for a bit before attempting
182  * to reconnect to a server that just dropped our connection.
183  *
184  * We implement an exponential backoff when trying to reestablish a TCP
185  * transport connection with the server.  Some servers like to drop a TCP
186  * connection when they are overworked, so we start with a short timeout and
187  * increase over time if the server is down or not responding.
188  */
189 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
190 
191 /*
192  * TCP idle timeout; client drops the transport socket if it is idle
193  * for this long.  Note that we also timeout UDP sockets to prevent
194  * holding port numbers when there is no RPC traffic.
195  */
196 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
197 
198 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
199 # undef  RPC_DEBUG_DATA
200 # define RPCDBG_FACILITY	RPCDBG_TRANS
201 #endif
202 
203 #ifdef RPC_DEBUG_DATA
204 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
205 {
206 	u8 *buf = (u8 *) packet;
207 	int j;
208 
209 	dprintk("RPC:       %s\n", msg);
210 	for (j = 0; j < count && j < 128; j += 4) {
211 		if (!(j & 31)) {
212 			if (j)
213 				dprintk("\n");
214 			dprintk("0x%04x ", j);
215 		}
216 		dprintk("%02x%02x%02x%02x ",
217 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
218 	}
219 	dprintk("\n");
220 }
221 #else
222 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
223 {
224 	/* NOP */
225 }
226 #endif
227 
228 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
229 {
230 	return (struct rpc_xprt *) sk->sk_user_data;
231 }
232 
233 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_un *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in *) &xprt->addr;
246 }
247 
248 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
249 {
250 	return (struct sockaddr_in6 *) &xprt->addr;
251 }
252 
253 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
254 {
255 	struct sockaddr *sap = xs_addr(xprt);
256 	struct sockaddr_in6 *sin6;
257 	struct sockaddr_in *sin;
258 	struct sockaddr_un *sun;
259 	char buf[128];
260 
261 	switch (sap->sa_family) {
262 	case AF_LOCAL:
263 		sun = xs_addr_un(xprt);
264 		strlcpy(buf, sun->sun_path, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		break;
268 	case AF_INET:
269 		(void)rpc_ntop(sap, buf, sizeof(buf));
270 		xprt->address_strings[RPC_DISPLAY_ADDR] =
271 						kstrdup(buf, GFP_KERNEL);
272 		sin = xs_addr_in(xprt);
273 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
274 		break;
275 	case AF_INET6:
276 		(void)rpc_ntop(sap, buf, sizeof(buf));
277 		xprt->address_strings[RPC_DISPLAY_ADDR] =
278 						kstrdup(buf, GFP_KERNEL);
279 		sin6 = xs_addr_in6(xprt);
280 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
281 		break;
282 	default:
283 		BUG();
284 	}
285 
286 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
287 }
288 
289 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
290 {
291 	struct sockaddr *sap = xs_addr(xprt);
292 	char buf[128];
293 
294 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
295 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
296 
297 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
298 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
299 }
300 
301 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
302 				     const char *protocol,
303 				     const char *netid)
304 {
305 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
306 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
307 	xs_format_common_peer_addresses(xprt);
308 	xs_format_common_peer_ports(xprt);
309 }
310 
311 static void xs_update_peer_port(struct rpc_xprt *xprt)
312 {
313 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
314 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
315 
316 	xs_format_common_peer_ports(xprt);
317 }
318 
319 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
320 {
321 	unsigned int i;
322 
323 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
324 		switch (i) {
325 		case RPC_DISPLAY_PROTO:
326 		case RPC_DISPLAY_NETID:
327 			continue;
328 		default:
329 			kfree(xprt->address_strings[i]);
330 		}
331 }
332 
333 static size_t
334 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
335 {
336 	size_t i,n;
337 
338 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
339 		return want;
340 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
341 	for (i = 0; i < n; i++) {
342 		if (buf->pages[i])
343 			continue;
344 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
345 		if (!buf->pages[i]) {
346 			i *= PAGE_SIZE;
347 			return i > buf->page_base ? i - buf->page_base : 0;
348 		}
349 	}
350 	return want;
351 }
352 
353 static ssize_t
354 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
355 {
356 	ssize_t ret;
357 	if (seek != 0)
358 		iov_iter_advance(&msg->msg_iter, seek);
359 	ret = sock_recvmsg(sock, msg, flags);
360 	return ret > 0 ? ret + seek : ret;
361 }
362 
363 static ssize_t
364 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
365 		struct kvec *kvec, size_t count, size_t seek)
366 {
367 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
368 	return xs_sock_recvmsg(sock, msg, flags, seek);
369 }
370 
371 static ssize_t
372 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
373 		struct bio_vec *bvec, unsigned long nr, size_t count,
374 		size_t seek)
375 {
376 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
377 	return xs_sock_recvmsg(sock, msg, flags, seek);
378 }
379 
380 static ssize_t
381 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
382 		size_t count)
383 {
384 	iov_iter_discard(&msg->msg_iter, READ, count);
385 	return sock_recvmsg(sock, msg, flags);
386 }
387 
388 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
389 static void
390 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
391 {
392 	struct bvec_iter bi = {
393 		.bi_size = count,
394 	};
395 	struct bio_vec bv;
396 
397 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
398 	for_each_bvec(bv, bvec, bi, bi)
399 		flush_dcache_page(bv.bv_page);
400 }
401 #else
402 static inline void
403 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
404 {
405 }
406 #endif
407 
408 static ssize_t
409 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
410 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
411 {
412 	size_t want, seek_init = seek, offset = 0;
413 	ssize_t ret;
414 
415 	want = min_t(size_t, count, buf->head[0].iov_len);
416 	if (seek < want) {
417 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
418 		if (ret <= 0)
419 			goto sock_err;
420 		offset += ret;
421 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
422 			goto out;
423 		if (ret != want)
424 			goto out;
425 		seek = 0;
426 	} else {
427 		seek -= want;
428 		offset += want;
429 	}
430 
431 	want = xs_alloc_sparse_pages(buf,
432 			min_t(size_t, count - offset, buf->page_len),
433 			GFP_KERNEL);
434 	if (seek < want) {
435 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
436 				xdr_buf_pagecount(buf),
437 				want + buf->page_base,
438 				seek + buf->page_base);
439 		if (ret <= 0)
440 			goto sock_err;
441 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
442 		ret -= buf->page_base;
443 		offset += ret;
444 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
445 			goto out;
446 		if (ret != want)
447 			goto out;
448 		seek = 0;
449 	} else {
450 		seek -= want;
451 		offset += want;
452 	}
453 
454 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
455 	if (seek < want) {
456 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
457 		if (ret <= 0)
458 			goto sock_err;
459 		offset += ret;
460 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
461 			goto out;
462 		if (ret != want)
463 			goto out;
464 	} else if (offset < seek_init)
465 		offset = seek_init;
466 	ret = -EMSGSIZE;
467 out:
468 	*read = offset - seek_init;
469 	return ret;
470 sock_err:
471 	offset += seek;
472 	goto out;
473 }
474 
475 static void
476 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
477 {
478 	if (!transport->recv.copied) {
479 		if (buf->head[0].iov_len >= transport->recv.offset)
480 			memcpy(buf->head[0].iov_base,
481 					&transport->recv.xid,
482 					transport->recv.offset);
483 		transport->recv.copied = transport->recv.offset;
484 	}
485 }
486 
487 static bool
488 xs_read_stream_request_done(struct sock_xprt *transport)
489 {
490 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
491 }
492 
493 static void
494 xs_read_stream_check_eor(struct sock_xprt *transport,
495 		struct msghdr *msg)
496 {
497 	if (xs_read_stream_request_done(transport))
498 		msg->msg_flags |= MSG_EOR;
499 }
500 
501 static ssize_t
502 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
503 		int flags, struct rpc_rqst *req)
504 {
505 	struct xdr_buf *buf = &req->rq_private_buf;
506 	size_t want, read;
507 	ssize_t ret;
508 
509 	xs_read_header(transport, buf);
510 
511 	want = transport->recv.len - transport->recv.offset;
512 	if (want != 0) {
513 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
514 				transport->recv.copied + want,
515 				transport->recv.copied,
516 				&read);
517 		transport->recv.offset += read;
518 		transport->recv.copied += read;
519 	}
520 
521 	if (transport->recv.offset == transport->recv.len)
522 		xs_read_stream_check_eor(transport, msg);
523 
524 	if (want == 0)
525 		return 0;
526 
527 	switch (ret) {
528 	default:
529 		break;
530 	case -EFAULT:
531 	case -EMSGSIZE:
532 		msg->msg_flags |= MSG_TRUNC;
533 		return read;
534 	case 0:
535 		return -ESHUTDOWN;
536 	}
537 	return ret < 0 ? ret : read;
538 }
539 
540 static size_t
541 xs_read_stream_headersize(bool isfrag)
542 {
543 	if (isfrag)
544 		return sizeof(__be32);
545 	return 3 * sizeof(__be32);
546 }
547 
548 static ssize_t
549 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
550 		int flags, size_t want, size_t seek)
551 {
552 	struct kvec kvec = {
553 		.iov_base = &transport->recv.fraghdr,
554 		.iov_len = want,
555 	};
556 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
557 }
558 
559 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
560 static ssize_t
561 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
562 {
563 	struct rpc_xprt *xprt = &transport->xprt;
564 	struct rpc_rqst *req;
565 	ssize_t ret;
566 
567 	/* Is this transport associated with the backchannel? */
568 	if (!xprt->bc_serv)
569 		return -ESHUTDOWN;
570 
571 	/* Look up and lock the request corresponding to the given XID */
572 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
573 	if (!req) {
574 		printk(KERN_WARNING "Callback slot table overflowed\n");
575 		return -ESHUTDOWN;
576 	}
577 	if (transport->recv.copied && !req->rq_private_buf.len)
578 		return -ESHUTDOWN;
579 
580 	ret = xs_read_stream_request(transport, msg, flags, req);
581 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
582 		xprt_complete_bc_request(req, transport->recv.copied);
583 	else
584 		req->rq_private_buf.len = transport->recv.copied;
585 
586 	return ret;
587 }
588 #else /* CONFIG_SUNRPC_BACKCHANNEL */
589 static ssize_t
590 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
591 {
592 	return -ESHUTDOWN;
593 }
594 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
595 
596 static ssize_t
597 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
598 {
599 	struct rpc_xprt *xprt = &transport->xprt;
600 	struct rpc_rqst *req;
601 	ssize_t ret = 0;
602 
603 	/* Look up and lock the request corresponding to the given XID */
604 	spin_lock(&xprt->queue_lock);
605 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
606 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
607 		msg->msg_flags |= MSG_TRUNC;
608 		goto out;
609 	}
610 	xprt_pin_rqst(req);
611 	spin_unlock(&xprt->queue_lock);
612 
613 	ret = xs_read_stream_request(transport, msg, flags, req);
614 
615 	spin_lock(&xprt->queue_lock);
616 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
617 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
618 	else
619 		req->rq_private_buf.len = transport->recv.copied;
620 	xprt_unpin_rqst(req);
621 out:
622 	spin_unlock(&xprt->queue_lock);
623 	return ret;
624 }
625 
626 static ssize_t
627 xs_read_stream(struct sock_xprt *transport, int flags)
628 {
629 	struct msghdr msg = { 0 };
630 	size_t want, read = 0;
631 	ssize_t ret = 0;
632 
633 	if (transport->recv.len == 0) {
634 		want = xs_read_stream_headersize(transport->recv.copied != 0);
635 		ret = xs_read_stream_header(transport, &msg, flags, want,
636 				transport->recv.offset);
637 		if (ret <= 0)
638 			goto out_err;
639 		transport->recv.offset = ret;
640 		if (transport->recv.offset != want)
641 			return transport->recv.offset;
642 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
643 			RPC_FRAGMENT_SIZE_MASK;
644 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
645 		read = ret;
646 	}
647 
648 	switch (be32_to_cpu(transport->recv.calldir)) {
649 	default:
650 		msg.msg_flags |= MSG_TRUNC;
651 		break;
652 	case RPC_CALL:
653 		ret = xs_read_stream_call(transport, &msg, flags);
654 		break;
655 	case RPC_REPLY:
656 		ret = xs_read_stream_reply(transport, &msg, flags);
657 	}
658 	if (msg.msg_flags & MSG_TRUNC) {
659 		transport->recv.calldir = cpu_to_be32(-1);
660 		transport->recv.copied = -1;
661 	}
662 	if (ret < 0)
663 		goto out_err;
664 	read += ret;
665 	if (transport->recv.offset < transport->recv.len) {
666 		if (!(msg.msg_flags & MSG_TRUNC))
667 			return read;
668 		msg.msg_flags = 0;
669 		ret = xs_read_discard(transport->sock, &msg, flags,
670 				transport->recv.len - transport->recv.offset);
671 		if (ret <= 0)
672 			goto out_err;
673 		transport->recv.offset += ret;
674 		read += ret;
675 		if (transport->recv.offset != transport->recv.len)
676 			return read;
677 	}
678 	if (xs_read_stream_request_done(transport)) {
679 		trace_xs_stream_read_request(transport);
680 		transport->recv.copied = 0;
681 	}
682 	transport->recv.offset = 0;
683 	transport->recv.len = 0;
684 	return read;
685 out_err:
686 	return ret != 0 ? ret : -ESHUTDOWN;
687 }
688 
689 static __poll_t xs_poll_socket(struct sock_xprt *transport)
690 {
691 	return transport->sock->ops->poll(transport->file, transport->sock,
692 			NULL);
693 }
694 
695 static bool xs_poll_socket_readable(struct sock_xprt *transport)
696 {
697 	__poll_t events = xs_poll_socket(transport);
698 
699 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
700 }
701 
702 static void xs_poll_check_readable(struct sock_xprt *transport)
703 {
704 
705 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
706 	if (!xs_poll_socket_readable(transport))
707 		return;
708 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
709 		queue_work(xprtiod_workqueue, &transport->recv_worker);
710 }
711 
712 static void xs_stream_data_receive(struct sock_xprt *transport)
713 {
714 	size_t read = 0;
715 	ssize_t ret = 0;
716 
717 	mutex_lock(&transport->recv_mutex);
718 	if (transport->sock == NULL)
719 		goto out;
720 	for (;;) {
721 		ret = xs_read_stream(transport, MSG_DONTWAIT);
722 		if (ret < 0)
723 			break;
724 		read += ret;
725 		cond_resched();
726 	}
727 	if (ret == -ESHUTDOWN)
728 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
729 	else
730 		xs_poll_check_readable(transport);
731 out:
732 	mutex_unlock(&transport->recv_mutex);
733 	trace_xs_stream_read_data(&transport->xprt, ret, read);
734 }
735 
736 static void xs_stream_data_receive_workfn(struct work_struct *work)
737 {
738 	struct sock_xprt *transport =
739 		container_of(work, struct sock_xprt, recv_worker);
740 	unsigned int pflags = memalloc_nofs_save();
741 
742 	xs_stream_data_receive(transport);
743 	memalloc_nofs_restore(pflags);
744 }
745 
746 static void
747 xs_stream_reset_connect(struct sock_xprt *transport)
748 {
749 	transport->recv.offset = 0;
750 	transport->recv.len = 0;
751 	transport->recv.copied = 0;
752 	transport->xmit.offset = 0;
753 }
754 
755 static void
756 xs_stream_start_connect(struct sock_xprt *transport)
757 {
758 	transport->xprt.stat.connect_count++;
759 	transport->xprt.stat.connect_start = jiffies;
760 }
761 
762 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
763 
764 /**
765  * xs_nospace - handle transmit was incomplete
766  * @req: pointer to RPC request
767  * @transport: pointer to struct sock_xprt
768  *
769  */
770 static int xs_nospace(struct rpc_rqst *req, struct sock_xprt *transport)
771 {
772 	struct rpc_xprt *xprt = &transport->xprt;
773 	struct sock *sk = transport->inet;
774 	int ret = -EAGAIN;
775 
776 	trace_rpc_socket_nospace(req, transport);
777 
778 	/* Protect against races with write_space */
779 	spin_lock(&xprt->transport_lock);
780 
781 	/* Don't race with disconnect */
782 	if (xprt_connected(xprt)) {
783 		struct socket_wq *wq;
784 
785 		rcu_read_lock();
786 		wq = rcu_dereference(sk->sk_wq);
787 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
788 		rcu_read_unlock();
789 
790 		/* wait for more buffer space */
791 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
792 		sk->sk_write_pending++;
793 		xprt_wait_for_buffer_space(xprt);
794 	} else
795 		ret = -ENOTCONN;
796 
797 	spin_unlock(&xprt->transport_lock);
798 	return ret;
799 }
800 
801 static int xs_sock_nospace(struct rpc_rqst *req)
802 {
803 	struct sock_xprt *transport =
804 		container_of(req->rq_xprt, struct sock_xprt, xprt);
805 	struct sock *sk = transport->inet;
806 	int ret = -EAGAIN;
807 
808 	lock_sock(sk);
809 	if (!sock_writeable(sk))
810 		ret = xs_nospace(req, transport);
811 	release_sock(sk);
812 	return ret;
813 }
814 
815 static int xs_stream_nospace(struct rpc_rqst *req)
816 {
817 	struct sock_xprt *transport =
818 		container_of(req->rq_xprt, struct sock_xprt, xprt);
819 	struct sock *sk = transport->inet;
820 	int ret = -EAGAIN;
821 
822 	lock_sock(sk);
823 	if (!sk_stream_memory_free(sk))
824 		ret = xs_nospace(req, transport);
825 	release_sock(sk);
826 	return ret;
827 }
828 
829 static void
830 xs_stream_prepare_request(struct rpc_rqst *req)
831 {
832 	xdr_free_bvec(&req->rq_rcv_buf);
833 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
834 }
835 
836 /*
837  * Determine if the previous message in the stream was aborted before it
838  * could complete transmission.
839  */
840 static bool
841 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
842 {
843 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
844 }
845 
846 /*
847  * Return the stream record marker field for a record of length < 2^31-1
848  */
849 static rpc_fraghdr
850 xs_stream_record_marker(struct xdr_buf *xdr)
851 {
852 	if (!xdr->len)
853 		return 0;
854 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
855 }
856 
857 /**
858  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
859  * @req: pointer to RPC request
860  *
861  * Return values:
862  *        0:	The request has been sent
863  *   EAGAIN:	The socket was blocked, please call again later to
864  *		complete the request
865  * ENOTCONN:	Caller needs to invoke connect logic then call again
866  *    other:	Some other error occurred, the request was not sent
867  */
868 static int xs_local_send_request(struct rpc_rqst *req)
869 {
870 	struct rpc_xprt *xprt = req->rq_xprt;
871 	struct sock_xprt *transport =
872 				container_of(xprt, struct sock_xprt, xprt);
873 	struct xdr_buf *xdr = &req->rq_snd_buf;
874 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
875 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
876 	struct msghdr msg = {
877 		.msg_flags	= XS_SENDMSG_FLAGS,
878 	};
879 	unsigned int sent;
880 	int status;
881 
882 	/* Close the stream if the previous transmission was incomplete */
883 	if (xs_send_request_was_aborted(transport, req)) {
884 		xs_close(xprt);
885 		return -ENOTCONN;
886 	}
887 
888 	xs_pktdump("packet data:",
889 			req->rq_svec->iov_base, req->rq_svec->iov_len);
890 
891 	req->rq_xtime = ktime_get();
892 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
893 				   transport->xmit.offset, rm, &sent);
894 	dprintk("RPC:       %s(%u) = %d\n",
895 			__func__, xdr->len - transport->xmit.offset, status);
896 
897 	if (status == -EAGAIN && sock_writeable(transport->inet))
898 		status = -ENOBUFS;
899 
900 	if (likely(sent > 0) || status == 0) {
901 		transport->xmit.offset += sent;
902 		req->rq_bytes_sent = transport->xmit.offset;
903 		if (likely(req->rq_bytes_sent >= msglen)) {
904 			req->rq_xmit_bytes_sent += transport->xmit.offset;
905 			transport->xmit.offset = 0;
906 			return 0;
907 		}
908 		status = -EAGAIN;
909 	}
910 
911 	switch (status) {
912 	case -ENOBUFS:
913 		break;
914 	case -EAGAIN:
915 		status = xs_stream_nospace(req);
916 		break;
917 	default:
918 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
919 			-status);
920 		fallthrough;
921 	case -EPIPE:
922 		xs_close(xprt);
923 		status = -ENOTCONN;
924 	}
925 
926 	return status;
927 }
928 
929 /**
930  * xs_udp_send_request - write an RPC request to a UDP socket
931  * @req: pointer to RPC request
932  *
933  * Return values:
934  *        0:	The request has been sent
935  *   EAGAIN:	The socket was blocked, please call again later to
936  *		complete the request
937  * ENOTCONN:	Caller needs to invoke connect logic then call again
938  *    other:	Some other error occurred, the request was not sent
939  */
940 static int xs_udp_send_request(struct rpc_rqst *req)
941 {
942 	struct rpc_xprt *xprt = req->rq_xprt;
943 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
944 	struct xdr_buf *xdr = &req->rq_snd_buf;
945 	struct msghdr msg = {
946 		.msg_name	= xs_addr(xprt),
947 		.msg_namelen	= xprt->addrlen,
948 		.msg_flags	= XS_SENDMSG_FLAGS,
949 	};
950 	unsigned int sent;
951 	int status;
952 
953 	xs_pktdump("packet data:",
954 				req->rq_svec->iov_base,
955 				req->rq_svec->iov_len);
956 
957 	if (!xprt_bound(xprt))
958 		return -ENOTCONN;
959 
960 	if (!xprt_request_get_cong(xprt, req))
961 		return -EBADSLT;
962 
963 	req->rq_xtime = ktime_get();
964 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
965 
966 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
967 			xdr->len, status);
968 
969 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
970 	if (status == -EPERM)
971 		goto process_status;
972 
973 	if (status == -EAGAIN && sock_writeable(transport->inet))
974 		status = -ENOBUFS;
975 
976 	if (sent > 0 || status == 0) {
977 		req->rq_xmit_bytes_sent += sent;
978 		if (sent >= req->rq_slen)
979 			return 0;
980 		/* Still some bytes left; set up for a retry later. */
981 		status = -EAGAIN;
982 	}
983 
984 process_status:
985 	switch (status) {
986 	case -ENOTSOCK:
987 		status = -ENOTCONN;
988 		/* Should we call xs_close() here? */
989 		break;
990 	case -EAGAIN:
991 		status = xs_sock_nospace(req);
992 		break;
993 	case -ENETUNREACH:
994 	case -ENOBUFS:
995 	case -EPIPE:
996 	case -ECONNREFUSED:
997 	case -EPERM:
998 		/* When the server has died, an ICMP port unreachable message
999 		 * prompts ECONNREFUSED. */
1000 		break;
1001 	default:
1002 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1003 			-status);
1004 	}
1005 
1006 	return status;
1007 }
1008 
1009 /**
1010  * xs_tcp_send_request - write an RPC request to a TCP socket
1011  * @req: pointer to RPC request
1012  *
1013  * Return values:
1014  *        0:	The request has been sent
1015  *   EAGAIN:	The socket was blocked, please call again later to
1016  *		complete the request
1017  * ENOTCONN:	Caller needs to invoke connect logic then call again
1018  *    other:	Some other error occurred, the request was not sent
1019  *
1020  * XXX: In the case of soft timeouts, should we eventually give up
1021  *	if sendmsg is not able to make progress?
1022  */
1023 static int xs_tcp_send_request(struct rpc_rqst *req)
1024 {
1025 	struct rpc_xprt *xprt = req->rq_xprt;
1026 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1027 	struct xdr_buf *xdr = &req->rq_snd_buf;
1028 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
1029 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1030 	struct msghdr msg = {
1031 		.msg_flags	= XS_SENDMSG_FLAGS,
1032 	};
1033 	bool vm_wait = false;
1034 	unsigned int sent;
1035 	int status;
1036 
1037 	/* Close the stream if the previous transmission was incomplete */
1038 	if (xs_send_request_was_aborted(transport, req)) {
1039 		if (transport->sock != NULL)
1040 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1041 		return -ENOTCONN;
1042 	}
1043 	if (!transport->inet)
1044 		return -ENOTCONN;
1045 
1046 	xs_pktdump("packet data:",
1047 				req->rq_svec->iov_base,
1048 				req->rq_svec->iov_len);
1049 
1050 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1051 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1052 
1053 	xs_set_srcport(transport, transport->sock);
1054 
1055 	/* Continue transmitting the packet/record. We must be careful
1056 	 * to cope with writespace callbacks arriving _after_ we have
1057 	 * called sendmsg(). */
1058 	req->rq_xtime = ktime_get();
1059 	tcp_sock_set_cork(transport->inet, true);
1060 	while (1) {
1061 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1062 					   transport->xmit.offset, rm, &sent);
1063 
1064 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1065 				xdr->len - transport->xmit.offset, status);
1066 
1067 		/* If we've sent the entire packet, immediately
1068 		 * reset the count of bytes sent. */
1069 		transport->xmit.offset += sent;
1070 		req->rq_bytes_sent = transport->xmit.offset;
1071 		if (likely(req->rq_bytes_sent >= msglen)) {
1072 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1073 			transport->xmit.offset = 0;
1074 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1075 				tcp_sock_set_cork(transport->inet, false);
1076 			return 0;
1077 		}
1078 
1079 		WARN_ON_ONCE(sent == 0 && status == 0);
1080 
1081 		if (status == -EAGAIN ) {
1082 			/*
1083 			 * Return EAGAIN if we're sure we're hitting the
1084 			 * socket send buffer limits.
1085 			 */
1086 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1087 				break;
1088 			/*
1089 			 * Did we hit a memory allocation failure?
1090 			 */
1091 			if (sent == 0) {
1092 				status = -ENOBUFS;
1093 				if (vm_wait)
1094 					break;
1095 				/* Retry, knowing now that we're below the
1096 				 * socket send buffer limit
1097 				 */
1098 				vm_wait = true;
1099 			}
1100 			continue;
1101 		}
1102 		if (status < 0)
1103 			break;
1104 		vm_wait = false;
1105 	}
1106 
1107 	switch (status) {
1108 	case -ENOTSOCK:
1109 		status = -ENOTCONN;
1110 		/* Should we call xs_close() here? */
1111 		break;
1112 	case -EAGAIN:
1113 		status = xs_stream_nospace(req);
1114 		break;
1115 	case -ECONNRESET:
1116 	case -ECONNREFUSED:
1117 	case -ENOTCONN:
1118 	case -EADDRINUSE:
1119 	case -ENOBUFS:
1120 	case -EPIPE:
1121 		break;
1122 	default:
1123 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1124 			-status);
1125 	}
1126 
1127 	return status;
1128 }
1129 
1130 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1131 {
1132 	transport->old_data_ready = sk->sk_data_ready;
1133 	transport->old_state_change = sk->sk_state_change;
1134 	transport->old_write_space = sk->sk_write_space;
1135 	transport->old_error_report = sk->sk_error_report;
1136 }
1137 
1138 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1139 {
1140 	sk->sk_data_ready = transport->old_data_ready;
1141 	sk->sk_state_change = transport->old_state_change;
1142 	sk->sk_write_space = transport->old_write_space;
1143 	sk->sk_error_report = transport->old_error_report;
1144 }
1145 
1146 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1147 {
1148 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1149 
1150 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1151 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1152 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1153 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1154 }
1155 
1156 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1157 {
1158 	set_bit(nr, &transport->sock_state);
1159 	queue_work(xprtiod_workqueue, &transport->error_worker);
1160 }
1161 
1162 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1163 {
1164 	xprt->connect_cookie++;
1165 	smp_mb__before_atomic();
1166 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1167 	clear_bit(XPRT_CLOSING, &xprt->state);
1168 	xs_sock_reset_state_flags(xprt);
1169 	smp_mb__after_atomic();
1170 }
1171 
1172 /**
1173  * xs_error_report - callback to handle TCP socket state errors
1174  * @sk: socket
1175  *
1176  * Note: we don't call sock_error() since there may be a rpc_task
1177  * using the socket, and so we don't want to clear sk->sk_err.
1178  */
1179 static void xs_error_report(struct sock *sk)
1180 {
1181 	struct sock_xprt *transport;
1182 	struct rpc_xprt *xprt;
1183 
1184 	if (!(xprt = xprt_from_sock(sk)))
1185 		return;
1186 
1187 	transport = container_of(xprt, struct sock_xprt, xprt);
1188 	transport->xprt_err = -sk->sk_err;
1189 	if (transport->xprt_err == 0)
1190 		return;
1191 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1192 			xprt, -transport->xprt_err);
1193 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1194 
1195 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1196 	smp_mb__before_atomic();
1197 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1198 }
1199 
1200 static void xs_reset_transport(struct sock_xprt *transport)
1201 {
1202 	struct socket *sock = transport->sock;
1203 	struct sock *sk = transport->inet;
1204 	struct rpc_xprt *xprt = &transport->xprt;
1205 	struct file *filp = transport->file;
1206 
1207 	if (sk == NULL)
1208 		return;
1209 
1210 	if (atomic_read(&transport->xprt.swapper))
1211 		sk_clear_memalloc(sk);
1212 
1213 	kernel_sock_shutdown(sock, SHUT_RDWR);
1214 
1215 	mutex_lock(&transport->recv_mutex);
1216 	lock_sock(sk);
1217 	transport->inet = NULL;
1218 	transport->sock = NULL;
1219 	transport->file = NULL;
1220 
1221 	sk->sk_user_data = NULL;
1222 
1223 	xs_restore_old_callbacks(transport, sk);
1224 	xprt_clear_connected(xprt);
1225 	xs_sock_reset_connection_flags(xprt);
1226 	/* Reset stream record info */
1227 	xs_stream_reset_connect(transport);
1228 	release_sock(sk);
1229 	mutex_unlock(&transport->recv_mutex);
1230 
1231 	trace_rpc_socket_close(xprt, sock);
1232 	fput(filp);
1233 
1234 	xprt_disconnect_done(xprt);
1235 }
1236 
1237 /**
1238  * xs_close - close a socket
1239  * @xprt: transport
1240  *
1241  * This is used when all requests are complete; ie, no DRC state remains
1242  * on the server we want to save.
1243  *
1244  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1245  * xs_reset_transport() zeroing the socket from underneath a writer.
1246  */
1247 static void xs_close(struct rpc_xprt *xprt)
1248 {
1249 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1250 
1251 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1252 
1253 	xs_reset_transport(transport);
1254 	xprt->reestablish_timeout = 0;
1255 }
1256 
1257 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1258 {
1259 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1260 		xprt);
1261 	xprt_disconnect_done(xprt);
1262 }
1263 
1264 static void xs_xprt_free(struct rpc_xprt *xprt)
1265 {
1266 	xs_free_peer_addresses(xprt);
1267 	xprt_free(xprt);
1268 }
1269 
1270 /**
1271  * xs_destroy - prepare to shutdown a transport
1272  * @xprt: doomed transport
1273  *
1274  */
1275 static void xs_destroy(struct rpc_xprt *xprt)
1276 {
1277 	struct sock_xprt *transport = container_of(xprt,
1278 			struct sock_xprt, xprt);
1279 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1280 
1281 	cancel_delayed_work_sync(&transport->connect_worker);
1282 	xs_close(xprt);
1283 	cancel_work_sync(&transport->recv_worker);
1284 	cancel_work_sync(&transport->error_worker);
1285 	xs_xprt_free(xprt);
1286 	module_put(THIS_MODULE);
1287 }
1288 
1289 /**
1290  * xs_udp_data_read_skb - receive callback for UDP sockets
1291  * @xprt: transport
1292  * @sk: socket
1293  * @skb: skbuff
1294  *
1295  */
1296 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1297 		struct sock *sk,
1298 		struct sk_buff *skb)
1299 {
1300 	struct rpc_task *task;
1301 	struct rpc_rqst *rovr;
1302 	int repsize, copied;
1303 	u32 _xid;
1304 	__be32 *xp;
1305 
1306 	repsize = skb->len;
1307 	if (repsize < 4) {
1308 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1309 		return;
1310 	}
1311 
1312 	/* Copy the XID from the skb... */
1313 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1314 	if (xp == NULL)
1315 		return;
1316 
1317 	/* Look up and lock the request corresponding to the given XID */
1318 	spin_lock(&xprt->queue_lock);
1319 	rovr = xprt_lookup_rqst(xprt, *xp);
1320 	if (!rovr)
1321 		goto out_unlock;
1322 	xprt_pin_rqst(rovr);
1323 	xprt_update_rtt(rovr->rq_task);
1324 	spin_unlock(&xprt->queue_lock);
1325 	task = rovr->rq_task;
1326 
1327 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1328 		copied = repsize;
1329 
1330 	/* Suck it into the iovec, verify checksum if not done by hw. */
1331 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1332 		spin_lock(&xprt->queue_lock);
1333 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1334 		goto out_unpin;
1335 	}
1336 
1337 
1338 	spin_lock(&xprt->transport_lock);
1339 	xprt_adjust_cwnd(xprt, task, copied);
1340 	spin_unlock(&xprt->transport_lock);
1341 	spin_lock(&xprt->queue_lock);
1342 	xprt_complete_rqst(task, copied);
1343 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1344 out_unpin:
1345 	xprt_unpin_rqst(rovr);
1346  out_unlock:
1347 	spin_unlock(&xprt->queue_lock);
1348 }
1349 
1350 static void xs_udp_data_receive(struct sock_xprt *transport)
1351 {
1352 	struct sk_buff *skb;
1353 	struct sock *sk;
1354 	int err;
1355 
1356 	mutex_lock(&transport->recv_mutex);
1357 	sk = transport->inet;
1358 	if (sk == NULL)
1359 		goto out;
1360 	for (;;) {
1361 		skb = skb_recv_udp(sk, 0, 1, &err);
1362 		if (skb == NULL)
1363 			break;
1364 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1365 		consume_skb(skb);
1366 		cond_resched();
1367 	}
1368 	xs_poll_check_readable(transport);
1369 out:
1370 	mutex_unlock(&transport->recv_mutex);
1371 }
1372 
1373 static void xs_udp_data_receive_workfn(struct work_struct *work)
1374 {
1375 	struct sock_xprt *transport =
1376 		container_of(work, struct sock_xprt, recv_worker);
1377 	unsigned int pflags = memalloc_nofs_save();
1378 
1379 	xs_udp_data_receive(transport);
1380 	memalloc_nofs_restore(pflags);
1381 }
1382 
1383 /**
1384  * xs_data_ready - "data ready" callback for UDP sockets
1385  * @sk: socket with data to read
1386  *
1387  */
1388 static void xs_data_ready(struct sock *sk)
1389 {
1390 	struct rpc_xprt *xprt;
1391 
1392 	dprintk("RPC:       xs_data_ready...\n");
1393 	xprt = xprt_from_sock(sk);
1394 	if (xprt != NULL) {
1395 		struct sock_xprt *transport = container_of(xprt,
1396 				struct sock_xprt, xprt);
1397 		transport->old_data_ready(sk);
1398 		/* Any data means we had a useful conversation, so
1399 		 * then we don't need to delay the next reconnect
1400 		 */
1401 		if (xprt->reestablish_timeout)
1402 			xprt->reestablish_timeout = 0;
1403 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1404 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1405 	}
1406 }
1407 
1408 /*
1409  * Helper function to force a TCP close if the server is sending
1410  * junk and/or it has put us in CLOSE_WAIT
1411  */
1412 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1413 {
1414 	xprt_force_disconnect(xprt);
1415 }
1416 
1417 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1418 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1419 {
1420 	return PAGE_SIZE;
1421 }
1422 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1423 
1424 /**
1425  * xs_tcp_state_change - callback to handle TCP socket state changes
1426  * @sk: socket whose state has changed
1427  *
1428  */
1429 static void xs_tcp_state_change(struct sock *sk)
1430 {
1431 	struct rpc_xprt *xprt;
1432 	struct sock_xprt *transport;
1433 
1434 	if (!(xprt = xprt_from_sock(sk)))
1435 		return;
1436 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1437 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1438 			sk->sk_state, xprt_connected(xprt),
1439 			sock_flag(sk, SOCK_DEAD),
1440 			sock_flag(sk, SOCK_ZAPPED),
1441 			sk->sk_shutdown);
1442 
1443 	transport = container_of(xprt, struct sock_xprt, xprt);
1444 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1445 	switch (sk->sk_state) {
1446 	case TCP_ESTABLISHED:
1447 		if (!xprt_test_and_set_connected(xprt)) {
1448 			xprt->connect_cookie++;
1449 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1450 			xprt_clear_connecting(xprt);
1451 
1452 			xprt->stat.connect_count++;
1453 			xprt->stat.connect_time += (long)jiffies -
1454 						   xprt->stat.connect_start;
1455 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1456 		}
1457 		break;
1458 	case TCP_FIN_WAIT1:
1459 		/* The client initiated a shutdown of the socket */
1460 		xprt->connect_cookie++;
1461 		xprt->reestablish_timeout = 0;
1462 		set_bit(XPRT_CLOSING, &xprt->state);
1463 		smp_mb__before_atomic();
1464 		clear_bit(XPRT_CONNECTED, &xprt->state);
1465 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1466 		smp_mb__after_atomic();
1467 		break;
1468 	case TCP_CLOSE_WAIT:
1469 		/* The server initiated a shutdown of the socket */
1470 		xprt->connect_cookie++;
1471 		clear_bit(XPRT_CONNECTED, &xprt->state);
1472 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1473 		fallthrough;
1474 	case TCP_CLOSING:
1475 		/*
1476 		 * If the server closed down the connection, make sure that
1477 		 * we back off before reconnecting
1478 		 */
1479 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1480 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1481 		break;
1482 	case TCP_LAST_ACK:
1483 		set_bit(XPRT_CLOSING, &xprt->state);
1484 		smp_mb__before_atomic();
1485 		clear_bit(XPRT_CONNECTED, &xprt->state);
1486 		smp_mb__after_atomic();
1487 		break;
1488 	case TCP_CLOSE:
1489 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1490 					&transport->sock_state))
1491 			xprt_clear_connecting(xprt);
1492 		clear_bit(XPRT_CLOSING, &xprt->state);
1493 		/* Trigger the socket release */
1494 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1495 	}
1496 }
1497 
1498 static void xs_write_space(struct sock *sk)
1499 {
1500 	struct socket_wq *wq;
1501 	struct sock_xprt *transport;
1502 	struct rpc_xprt *xprt;
1503 
1504 	if (!sk->sk_socket)
1505 		return;
1506 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1507 
1508 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1509 		return;
1510 	transport = container_of(xprt, struct sock_xprt, xprt);
1511 	rcu_read_lock();
1512 	wq = rcu_dereference(sk->sk_wq);
1513 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1514 		goto out;
1515 
1516 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1517 	sk->sk_write_pending--;
1518 out:
1519 	rcu_read_unlock();
1520 }
1521 
1522 /**
1523  * xs_udp_write_space - callback invoked when socket buffer space
1524  *                             becomes available
1525  * @sk: socket whose state has changed
1526  *
1527  * Called when more output buffer space is available for this socket.
1528  * We try not to wake our writers until they can make "significant"
1529  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1530  * with a bunch of small requests.
1531  */
1532 static void xs_udp_write_space(struct sock *sk)
1533 {
1534 	/* from net/core/sock.c:sock_def_write_space */
1535 	if (sock_writeable(sk))
1536 		xs_write_space(sk);
1537 }
1538 
1539 /**
1540  * xs_tcp_write_space - callback invoked when socket buffer space
1541  *                             becomes available
1542  * @sk: socket whose state has changed
1543  *
1544  * Called when more output buffer space is available for this socket.
1545  * We try not to wake our writers until they can make "significant"
1546  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1547  * with a bunch of small requests.
1548  */
1549 static void xs_tcp_write_space(struct sock *sk)
1550 {
1551 	/* from net/core/stream.c:sk_stream_write_space */
1552 	if (sk_stream_is_writeable(sk))
1553 		xs_write_space(sk);
1554 }
1555 
1556 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1557 {
1558 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1559 	struct sock *sk = transport->inet;
1560 
1561 	if (transport->rcvsize) {
1562 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1563 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1564 	}
1565 	if (transport->sndsize) {
1566 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1567 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1568 		sk->sk_write_space(sk);
1569 	}
1570 }
1571 
1572 /**
1573  * xs_udp_set_buffer_size - set send and receive limits
1574  * @xprt: generic transport
1575  * @sndsize: requested size of send buffer, in bytes
1576  * @rcvsize: requested size of receive buffer, in bytes
1577  *
1578  * Set socket send and receive buffer size limits.
1579  */
1580 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1581 {
1582 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1583 
1584 	transport->sndsize = 0;
1585 	if (sndsize)
1586 		transport->sndsize = sndsize + 1024;
1587 	transport->rcvsize = 0;
1588 	if (rcvsize)
1589 		transport->rcvsize = rcvsize + 1024;
1590 
1591 	xs_udp_do_set_buffer_size(xprt);
1592 }
1593 
1594 /**
1595  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1596  * @xprt: controlling transport
1597  * @task: task that timed out
1598  *
1599  * Adjust the congestion window after a retransmit timeout has occurred.
1600  */
1601 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1602 {
1603 	spin_lock(&xprt->transport_lock);
1604 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1605 	spin_unlock(&xprt->transport_lock);
1606 }
1607 
1608 static int xs_get_random_port(void)
1609 {
1610 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1611 	unsigned short range;
1612 	unsigned short rand;
1613 
1614 	if (max < min)
1615 		return -EADDRINUSE;
1616 	range = max - min + 1;
1617 	rand = (unsigned short) prandom_u32() % range;
1618 	return rand + min;
1619 }
1620 
1621 static unsigned short xs_sock_getport(struct socket *sock)
1622 {
1623 	struct sockaddr_storage buf;
1624 	unsigned short port = 0;
1625 
1626 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1627 		goto out;
1628 	switch (buf.ss_family) {
1629 	case AF_INET6:
1630 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1631 		break;
1632 	case AF_INET:
1633 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1634 	}
1635 out:
1636 	return port;
1637 }
1638 
1639 /**
1640  * xs_set_port - reset the port number in the remote endpoint address
1641  * @xprt: generic transport
1642  * @port: new port number
1643  *
1644  */
1645 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1646 {
1647 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1648 
1649 	rpc_set_port(xs_addr(xprt), port);
1650 	xs_update_peer_port(xprt);
1651 }
1652 
1653 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1654 {
1655 	if (transport->srcport == 0 && transport->xprt.reuseport)
1656 		transport->srcport = xs_sock_getport(sock);
1657 }
1658 
1659 static int xs_get_srcport(struct sock_xprt *transport)
1660 {
1661 	int port = transport->srcport;
1662 
1663 	if (port == 0 && transport->xprt.resvport)
1664 		port = xs_get_random_port();
1665 	return port;
1666 }
1667 
1668 unsigned short get_srcport(struct rpc_xprt *xprt)
1669 {
1670 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1671 	unsigned short ret = 0;
1672 	mutex_lock(&sock->recv_mutex);
1673 	if (sock->sock)
1674 		ret = xs_sock_getport(sock->sock);
1675 	mutex_unlock(&sock->recv_mutex);
1676 	return ret;
1677 }
1678 EXPORT_SYMBOL(get_srcport);
1679 
1680 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1681 {
1682 	if (transport->srcport != 0)
1683 		transport->srcport = 0;
1684 	if (!transport->xprt.resvport)
1685 		return 0;
1686 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1687 		return xprt_max_resvport;
1688 	return --port;
1689 }
1690 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1691 {
1692 	struct sockaddr_storage myaddr;
1693 	int err, nloop = 0;
1694 	int port = xs_get_srcport(transport);
1695 	unsigned short last;
1696 
1697 	/*
1698 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1699 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1700 	 * port selection happen implicitly when the socket is used
1701 	 * (for example at connect time).
1702 	 *
1703 	 * This ensures that we can continue to establish TCP
1704 	 * connections even when all local ephemeral ports are already
1705 	 * a part of some TCP connection.  This makes no difference
1706 	 * for UDP sockets, but also doesn't harm them.
1707 	 *
1708 	 * If we're asking for any reserved port (i.e. port == 0 &&
1709 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1710 	 * ensure that port is non-zero and we will bind as needed.
1711 	 */
1712 	if (port <= 0)
1713 		return port;
1714 
1715 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1716 	do {
1717 		rpc_set_port((struct sockaddr *)&myaddr, port);
1718 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1719 				transport->xprt.addrlen);
1720 		if (err == 0) {
1721 			if (transport->xprt.reuseport)
1722 				transport->srcport = port;
1723 			break;
1724 		}
1725 		last = port;
1726 		port = xs_next_srcport(transport, port);
1727 		if (port > last)
1728 			nloop++;
1729 	} while (err == -EADDRINUSE && nloop != 2);
1730 
1731 	if (myaddr.ss_family == AF_INET)
1732 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1733 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1734 				port, err ? "failed" : "ok", err);
1735 	else
1736 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1737 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1738 				port, err ? "failed" : "ok", err);
1739 	return err;
1740 }
1741 
1742 /*
1743  * We don't support autobind on AF_LOCAL sockets
1744  */
1745 static void xs_local_rpcbind(struct rpc_task *task)
1746 {
1747 	xprt_set_bound(task->tk_xprt);
1748 }
1749 
1750 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1751 {
1752 }
1753 
1754 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1755 static struct lock_class_key xs_key[3];
1756 static struct lock_class_key xs_slock_key[3];
1757 
1758 static inline void xs_reclassify_socketu(struct socket *sock)
1759 {
1760 	struct sock *sk = sock->sk;
1761 
1762 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1763 		&xs_slock_key[0], "sk_lock-AF_LOCAL-RPC", &xs_key[0]);
1764 }
1765 
1766 static inline void xs_reclassify_socket4(struct socket *sock)
1767 {
1768 	struct sock *sk = sock->sk;
1769 
1770 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1771 		&xs_slock_key[1], "sk_lock-AF_INET-RPC", &xs_key[1]);
1772 }
1773 
1774 static inline void xs_reclassify_socket6(struct socket *sock)
1775 {
1776 	struct sock *sk = sock->sk;
1777 
1778 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1779 		&xs_slock_key[2], "sk_lock-AF_INET6-RPC", &xs_key[2]);
1780 }
1781 
1782 static inline void xs_reclassify_socket(int family, struct socket *sock)
1783 {
1784 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1785 		return;
1786 
1787 	switch (family) {
1788 	case AF_LOCAL:
1789 		xs_reclassify_socketu(sock);
1790 		break;
1791 	case AF_INET:
1792 		xs_reclassify_socket4(sock);
1793 		break;
1794 	case AF_INET6:
1795 		xs_reclassify_socket6(sock);
1796 		break;
1797 	}
1798 }
1799 #else
1800 static inline void xs_reclassify_socket(int family, struct socket *sock)
1801 {
1802 }
1803 #endif
1804 
1805 static void xs_dummy_setup_socket(struct work_struct *work)
1806 {
1807 }
1808 
1809 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1810 		struct sock_xprt *transport, int family, int type,
1811 		int protocol, bool reuseport)
1812 {
1813 	struct file *filp;
1814 	struct socket *sock;
1815 	int err;
1816 
1817 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1818 	if (err < 0) {
1819 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1820 				protocol, -err);
1821 		goto out;
1822 	}
1823 	xs_reclassify_socket(family, sock);
1824 
1825 	if (reuseport)
1826 		sock_set_reuseport(sock->sk);
1827 
1828 	err = xs_bind(transport, sock);
1829 	if (err) {
1830 		sock_release(sock);
1831 		goto out;
1832 	}
1833 
1834 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1835 	if (IS_ERR(filp))
1836 		return ERR_CAST(filp);
1837 	transport->file = filp;
1838 
1839 	return sock;
1840 out:
1841 	return ERR_PTR(err);
1842 }
1843 
1844 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1845 				      struct socket *sock)
1846 {
1847 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1848 									xprt);
1849 
1850 	if (!transport->inet) {
1851 		struct sock *sk = sock->sk;
1852 
1853 		lock_sock(sk);
1854 
1855 		xs_save_old_callbacks(transport, sk);
1856 
1857 		sk->sk_user_data = xprt;
1858 		sk->sk_data_ready = xs_data_ready;
1859 		sk->sk_write_space = xs_udp_write_space;
1860 		sock_set_flag(sk, SOCK_FASYNC);
1861 		sk->sk_error_report = xs_error_report;
1862 
1863 		xprt_clear_connected(xprt);
1864 
1865 		/* Reset to new socket */
1866 		transport->sock = sock;
1867 		transport->inet = sk;
1868 
1869 		release_sock(sk);
1870 	}
1871 
1872 	xs_stream_start_connect(transport);
1873 
1874 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1875 }
1876 
1877 /**
1878  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1879  * @transport: socket transport to connect
1880  */
1881 static int xs_local_setup_socket(struct sock_xprt *transport)
1882 {
1883 	struct rpc_xprt *xprt = &transport->xprt;
1884 	struct file *filp;
1885 	struct socket *sock;
1886 	int status;
1887 
1888 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1889 					SOCK_STREAM, 0, &sock, 1);
1890 	if (status < 0) {
1891 		dprintk("RPC:       can't create AF_LOCAL "
1892 			"transport socket (%d).\n", -status);
1893 		goto out;
1894 	}
1895 	xs_reclassify_socket(AF_LOCAL, sock);
1896 
1897 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1898 	if (IS_ERR(filp)) {
1899 		status = PTR_ERR(filp);
1900 		goto out;
1901 	}
1902 	transport->file = filp;
1903 
1904 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1905 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1906 
1907 	status = xs_local_finish_connecting(xprt, sock);
1908 	trace_rpc_socket_connect(xprt, sock, status);
1909 	switch (status) {
1910 	case 0:
1911 		dprintk("RPC:       xprt %p connected to %s\n",
1912 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1913 		xprt->stat.connect_count++;
1914 		xprt->stat.connect_time += (long)jiffies -
1915 					   xprt->stat.connect_start;
1916 		xprt_set_connected(xprt);
1917 		break;
1918 	case -ENOBUFS:
1919 		break;
1920 	case -ENOENT:
1921 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1922 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1923 		break;
1924 	case -ECONNREFUSED:
1925 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1926 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1927 		break;
1928 	default:
1929 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1930 				__func__, -status,
1931 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1932 	}
1933 
1934 out:
1935 	xprt_clear_connecting(xprt);
1936 	xprt_wake_pending_tasks(xprt, status);
1937 	return status;
1938 }
1939 
1940 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1941 {
1942 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1943 	int ret;
1944 
1945 	if (RPC_IS_ASYNC(task)) {
1946 		/*
1947 		 * We want the AF_LOCAL connect to be resolved in the
1948 		 * filesystem namespace of the process making the rpc
1949 		 * call.  Thus we connect synchronously.
1950 		 *
1951 		 * If we want to support asynchronous AF_LOCAL calls,
1952 		 * we'll need to figure out how to pass a namespace to
1953 		 * connect.
1954 		 */
1955 		task->tk_rpc_status = -ENOTCONN;
1956 		rpc_exit(task, -ENOTCONN);
1957 		return;
1958 	}
1959 	ret = xs_local_setup_socket(transport);
1960 	if (ret && !RPC_IS_SOFTCONN(task))
1961 		msleep_interruptible(15000);
1962 }
1963 
1964 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1965 /*
1966  * Note that this should be called with XPRT_LOCKED held, or recv_mutex
1967  * held, or when we otherwise know that we have exclusive access to the
1968  * socket, to guard against races with xs_reset_transport.
1969  */
1970 static void xs_set_memalloc(struct rpc_xprt *xprt)
1971 {
1972 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1973 			xprt);
1974 
1975 	/*
1976 	 * If there's no sock, then we have nothing to set. The
1977 	 * reconnecting process will get it for us.
1978 	 */
1979 	if (!transport->inet)
1980 		return;
1981 	if (atomic_read(&xprt->swapper))
1982 		sk_set_memalloc(transport->inet);
1983 }
1984 
1985 /**
1986  * xs_enable_swap - Tag this transport as being used for swap.
1987  * @xprt: transport to tag
1988  *
1989  * Take a reference to this transport on behalf of the rpc_clnt, and
1990  * optionally mark it for swapping if it wasn't already.
1991  */
1992 static int
1993 xs_enable_swap(struct rpc_xprt *xprt)
1994 {
1995 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1996 
1997 	mutex_lock(&xs->recv_mutex);
1998 	if (atomic_inc_return(&xprt->swapper) == 1 &&
1999 	    xs->inet)
2000 		sk_set_memalloc(xs->inet);
2001 	mutex_unlock(&xs->recv_mutex);
2002 	return 0;
2003 }
2004 
2005 /**
2006  * xs_disable_swap - Untag this transport as being used for swap.
2007  * @xprt: transport to tag
2008  *
2009  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2010  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2011  */
2012 static void
2013 xs_disable_swap(struct rpc_xprt *xprt)
2014 {
2015 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2016 
2017 	mutex_lock(&xs->recv_mutex);
2018 	if (atomic_dec_and_test(&xprt->swapper) &&
2019 	    xs->inet)
2020 		sk_clear_memalloc(xs->inet);
2021 	mutex_unlock(&xs->recv_mutex);
2022 }
2023 #else
2024 static void xs_set_memalloc(struct rpc_xprt *xprt)
2025 {
2026 }
2027 
2028 static int
2029 xs_enable_swap(struct rpc_xprt *xprt)
2030 {
2031 	return -EINVAL;
2032 }
2033 
2034 static void
2035 xs_disable_swap(struct rpc_xprt *xprt)
2036 {
2037 }
2038 #endif
2039 
2040 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2041 {
2042 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2043 
2044 	if (!transport->inet) {
2045 		struct sock *sk = sock->sk;
2046 
2047 		lock_sock(sk);
2048 
2049 		xs_save_old_callbacks(transport, sk);
2050 
2051 		sk->sk_user_data = xprt;
2052 		sk->sk_data_ready = xs_data_ready;
2053 		sk->sk_write_space = xs_udp_write_space;
2054 		sock_set_flag(sk, SOCK_FASYNC);
2055 
2056 		xprt_set_connected(xprt);
2057 
2058 		/* Reset to new socket */
2059 		transport->sock = sock;
2060 		transport->inet = sk;
2061 
2062 		xs_set_memalloc(xprt);
2063 
2064 		release_sock(sk);
2065 	}
2066 	xs_udp_do_set_buffer_size(xprt);
2067 
2068 	xprt->stat.connect_start = jiffies;
2069 }
2070 
2071 static void xs_udp_setup_socket(struct work_struct *work)
2072 {
2073 	struct sock_xprt *transport =
2074 		container_of(work, struct sock_xprt, connect_worker.work);
2075 	struct rpc_xprt *xprt = &transport->xprt;
2076 	struct socket *sock;
2077 	int status = -EIO;
2078 	unsigned int pflags = current->flags;
2079 
2080 	if (atomic_read(&xprt->swapper))
2081 		current->flags |= PF_MEMALLOC;
2082 	sock = xs_create_sock(xprt, transport,
2083 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2084 			IPPROTO_UDP, false);
2085 	if (IS_ERR(sock))
2086 		goto out;
2087 
2088 	dprintk("RPC:       worker connecting xprt %p via %s to "
2089 				"%s (port %s)\n", xprt,
2090 			xprt->address_strings[RPC_DISPLAY_PROTO],
2091 			xprt->address_strings[RPC_DISPLAY_ADDR],
2092 			xprt->address_strings[RPC_DISPLAY_PORT]);
2093 
2094 	xs_udp_finish_connecting(xprt, sock);
2095 	trace_rpc_socket_connect(xprt, sock, 0);
2096 	status = 0;
2097 out:
2098 	xprt_clear_connecting(xprt);
2099 	xprt_unlock_connect(xprt, transport);
2100 	xprt_wake_pending_tasks(xprt, status);
2101 	current_restore_flags(pflags, PF_MEMALLOC);
2102 }
2103 
2104 /**
2105  * xs_tcp_shutdown - gracefully shut down a TCP socket
2106  * @xprt: transport
2107  *
2108  * Initiates a graceful shutdown of the TCP socket by calling the
2109  * equivalent of shutdown(SHUT_RDWR);
2110  */
2111 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2112 {
2113 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2114 	struct socket *sock = transport->sock;
2115 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2116 
2117 	if (sock == NULL)
2118 		return;
2119 	if (!xprt->reuseport) {
2120 		xs_close(xprt);
2121 		return;
2122 	}
2123 	switch (skst) {
2124 	case TCP_FIN_WAIT1:
2125 	case TCP_FIN_WAIT2:
2126 		break;
2127 	case TCP_ESTABLISHED:
2128 	case TCP_CLOSE_WAIT:
2129 		kernel_sock_shutdown(sock, SHUT_RDWR);
2130 		trace_rpc_socket_shutdown(xprt, sock);
2131 		break;
2132 	default:
2133 		xs_reset_transport(transport);
2134 	}
2135 }
2136 
2137 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2138 		struct socket *sock)
2139 {
2140 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2141 	unsigned int keepidle;
2142 	unsigned int keepcnt;
2143 	unsigned int timeo;
2144 
2145 	spin_lock(&xprt->transport_lock);
2146 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2147 	keepcnt = xprt->timeout->to_retries + 1;
2148 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2149 		(xprt->timeout->to_retries + 1);
2150 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2151 	spin_unlock(&xprt->transport_lock);
2152 
2153 	/* TCP Keepalive options */
2154 	sock_set_keepalive(sock->sk);
2155 	tcp_sock_set_keepidle(sock->sk, keepidle);
2156 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2157 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2158 
2159 	/* TCP user timeout (see RFC5482) */
2160 	tcp_sock_set_user_timeout(sock->sk, timeo);
2161 }
2162 
2163 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2164 		unsigned long connect_timeout,
2165 		unsigned long reconnect_timeout)
2166 {
2167 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2168 	struct rpc_timeout to;
2169 	unsigned long initval;
2170 
2171 	spin_lock(&xprt->transport_lock);
2172 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2173 		xprt->max_reconnect_timeout = reconnect_timeout;
2174 	if (connect_timeout < xprt->connect_timeout) {
2175 		memcpy(&to, xprt->timeout, sizeof(to));
2176 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2177 		/* Arbitrary lower limit */
2178 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2179 			initval = XS_TCP_INIT_REEST_TO << 1;
2180 		to.to_initval = initval;
2181 		to.to_maxval = initval;
2182 		memcpy(&transport->tcp_timeout, &to,
2183 				sizeof(transport->tcp_timeout));
2184 		xprt->timeout = &transport->tcp_timeout;
2185 		xprt->connect_timeout = connect_timeout;
2186 	}
2187 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2188 	spin_unlock(&xprt->transport_lock);
2189 }
2190 
2191 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2192 {
2193 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2194 
2195 	if (!transport->inet) {
2196 		struct sock *sk = sock->sk;
2197 
2198 		/* Avoid temporary address, they are bad for long-lived
2199 		 * connections such as NFS mounts.
2200 		 * RFC4941, section 3.6 suggests that:
2201 		 *    Individual applications, which have specific
2202 		 *    knowledge about the normal duration of connections,
2203 		 *    MAY override this as appropriate.
2204 		 */
2205 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2206 			ip6_sock_set_addr_preferences(sk,
2207 				IPV6_PREFER_SRC_PUBLIC);
2208 		}
2209 
2210 		xs_tcp_set_socket_timeouts(xprt, sock);
2211 		tcp_sock_set_nodelay(sk);
2212 
2213 		lock_sock(sk);
2214 
2215 		xs_save_old_callbacks(transport, sk);
2216 
2217 		sk->sk_user_data = xprt;
2218 		sk->sk_data_ready = xs_data_ready;
2219 		sk->sk_state_change = xs_tcp_state_change;
2220 		sk->sk_write_space = xs_tcp_write_space;
2221 		sock_set_flag(sk, SOCK_FASYNC);
2222 		sk->sk_error_report = xs_error_report;
2223 
2224 		/* socket options */
2225 		sock_reset_flag(sk, SOCK_LINGER);
2226 
2227 		xprt_clear_connected(xprt);
2228 
2229 		/* Reset to new socket */
2230 		transport->sock = sock;
2231 		transport->inet = sk;
2232 
2233 		release_sock(sk);
2234 	}
2235 
2236 	if (!xprt_bound(xprt))
2237 		return -ENOTCONN;
2238 
2239 	xs_set_memalloc(xprt);
2240 
2241 	xs_stream_start_connect(transport);
2242 
2243 	/* Tell the socket layer to start connecting... */
2244 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2245 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2246 }
2247 
2248 /**
2249  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2250  * @work: queued work item
2251  *
2252  * Invoked by a work queue tasklet.
2253  */
2254 static void xs_tcp_setup_socket(struct work_struct *work)
2255 {
2256 	struct sock_xprt *transport =
2257 		container_of(work, struct sock_xprt, connect_worker.work);
2258 	struct socket *sock = transport->sock;
2259 	struct rpc_xprt *xprt = &transport->xprt;
2260 	int status;
2261 	unsigned int pflags = current->flags;
2262 
2263 	if (atomic_read(&xprt->swapper))
2264 		current->flags |= PF_MEMALLOC;
2265 
2266 	if (xprt_connected(xprt))
2267 		goto out;
2268 	if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,
2269 			       &transport->sock_state) ||
2270 	    !sock) {
2271 		xs_reset_transport(transport);
2272 		sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
2273 				      SOCK_STREAM, IPPROTO_TCP, true);
2274 		if (IS_ERR(sock)) {
2275 			xprt_wake_pending_tasks(xprt, PTR_ERR(sock));
2276 			goto out;
2277 		}
2278 	}
2279 
2280 	dprintk("RPC:       worker connecting xprt %p via %s to "
2281 				"%s (port %s)\n", xprt,
2282 			xprt->address_strings[RPC_DISPLAY_PROTO],
2283 			xprt->address_strings[RPC_DISPLAY_ADDR],
2284 			xprt->address_strings[RPC_DISPLAY_PORT]);
2285 
2286 	status = xs_tcp_finish_connecting(xprt, sock);
2287 	trace_rpc_socket_connect(xprt, sock, status);
2288 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2289 			xprt, -status, xprt_connected(xprt),
2290 			sock->sk->sk_state);
2291 	switch (status) {
2292 	case 0:
2293 	case -EINPROGRESS:
2294 		/* SYN_SENT! */
2295 		set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
2296 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2297 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2298 		fallthrough;
2299 	case -EALREADY:
2300 		goto out_unlock;
2301 	case -EADDRNOTAVAIL:
2302 		/* Source port number is unavailable. Try a new one! */
2303 		transport->srcport = 0;
2304 		status = -EAGAIN;
2305 		break;
2306 	case -EINVAL:
2307 		/* Happens, for instance, if the user specified a link
2308 		 * local IPv6 address without a scope-id.
2309 		 */
2310 	case -ECONNREFUSED:
2311 	case -ECONNRESET:
2312 	case -ENETDOWN:
2313 	case -ENETUNREACH:
2314 	case -EHOSTUNREACH:
2315 	case -EADDRINUSE:
2316 	case -ENOBUFS:
2317 		break;
2318 	default:
2319 		printk("%s: connect returned unhandled error %d\n",
2320 			__func__, status);
2321 		status = -EAGAIN;
2322 	}
2323 
2324 	/* xs_tcp_force_close() wakes tasks with a fixed error code.
2325 	 * We need to wake them first to ensure the correct error code.
2326 	 */
2327 	xprt_wake_pending_tasks(xprt, status);
2328 	xs_tcp_force_close(xprt);
2329 out:
2330 	xprt_clear_connecting(xprt);
2331 out_unlock:
2332 	xprt_unlock_connect(xprt, transport);
2333 	current_restore_flags(pflags, PF_MEMALLOC);
2334 }
2335 
2336 /**
2337  * xs_connect - connect a socket to a remote endpoint
2338  * @xprt: pointer to transport structure
2339  * @task: address of RPC task that manages state of connect request
2340  *
2341  * TCP: If the remote end dropped the connection, delay reconnecting.
2342  *
2343  * UDP socket connects are synchronous, but we use a work queue anyway
2344  * to guarantee that even unprivileged user processes can set up a
2345  * socket on a privileged port.
2346  *
2347  * If a UDP socket connect fails, the delay behavior here prevents
2348  * retry floods (hard mounts).
2349  */
2350 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2351 {
2352 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2353 	unsigned long delay = 0;
2354 
2355 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2356 
2357 	if (transport->sock != NULL) {
2358 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2359 			"seconds\n", xprt, xprt->reestablish_timeout / HZ);
2360 
2361 		delay = xprt_reconnect_delay(xprt);
2362 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2363 
2364 	} else
2365 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2366 
2367 	queue_delayed_work(xprtiod_workqueue,
2368 			&transport->connect_worker,
2369 			delay);
2370 }
2371 
2372 static void xs_wake_disconnect(struct sock_xprt *transport)
2373 {
2374 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2375 		xs_tcp_force_close(&transport->xprt);
2376 }
2377 
2378 static void xs_wake_write(struct sock_xprt *transport)
2379 {
2380 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2381 		xprt_write_space(&transport->xprt);
2382 }
2383 
2384 static void xs_wake_error(struct sock_xprt *transport)
2385 {
2386 	int sockerr;
2387 
2388 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2389 		return;
2390 	mutex_lock(&transport->recv_mutex);
2391 	if (transport->sock == NULL)
2392 		goto out;
2393 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2394 		goto out;
2395 	sockerr = xchg(&transport->xprt_err, 0);
2396 	if (sockerr < 0)
2397 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2398 out:
2399 	mutex_unlock(&transport->recv_mutex);
2400 }
2401 
2402 static void xs_wake_pending(struct sock_xprt *transport)
2403 {
2404 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2405 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2406 }
2407 
2408 static void xs_error_handle(struct work_struct *work)
2409 {
2410 	struct sock_xprt *transport = container_of(work,
2411 			struct sock_xprt, error_worker);
2412 
2413 	xs_wake_disconnect(transport);
2414 	xs_wake_write(transport);
2415 	xs_wake_error(transport);
2416 	xs_wake_pending(transport);
2417 }
2418 
2419 /**
2420  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2421  * @xprt: rpc_xprt struct containing statistics
2422  * @seq: output file
2423  *
2424  */
2425 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2426 {
2427 	long idle_time = 0;
2428 
2429 	if (xprt_connected(xprt))
2430 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2431 
2432 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2433 			"%llu %llu %lu %llu %llu\n",
2434 			xprt->stat.bind_count,
2435 			xprt->stat.connect_count,
2436 			xprt->stat.connect_time / HZ,
2437 			idle_time,
2438 			xprt->stat.sends,
2439 			xprt->stat.recvs,
2440 			xprt->stat.bad_xids,
2441 			xprt->stat.req_u,
2442 			xprt->stat.bklog_u,
2443 			xprt->stat.max_slots,
2444 			xprt->stat.sending_u,
2445 			xprt->stat.pending_u);
2446 }
2447 
2448 /**
2449  * xs_udp_print_stats - display UDP socket-specific stats
2450  * @xprt: rpc_xprt struct containing statistics
2451  * @seq: output file
2452  *
2453  */
2454 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2455 {
2456 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2457 
2458 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2459 			"%lu %llu %llu\n",
2460 			transport->srcport,
2461 			xprt->stat.bind_count,
2462 			xprt->stat.sends,
2463 			xprt->stat.recvs,
2464 			xprt->stat.bad_xids,
2465 			xprt->stat.req_u,
2466 			xprt->stat.bklog_u,
2467 			xprt->stat.max_slots,
2468 			xprt->stat.sending_u,
2469 			xprt->stat.pending_u);
2470 }
2471 
2472 /**
2473  * xs_tcp_print_stats - display TCP socket-specific stats
2474  * @xprt: rpc_xprt struct containing statistics
2475  * @seq: output file
2476  *
2477  */
2478 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2479 {
2480 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2481 	long idle_time = 0;
2482 
2483 	if (xprt_connected(xprt))
2484 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2485 
2486 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2487 			"%llu %llu %lu %llu %llu\n",
2488 			transport->srcport,
2489 			xprt->stat.bind_count,
2490 			xprt->stat.connect_count,
2491 			xprt->stat.connect_time / HZ,
2492 			idle_time,
2493 			xprt->stat.sends,
2494 			xprt->stat.recvs,
2495 			xprt->stat.bad_xids,
2496 			xprt->stat.req_u,
2497 			xprt->stat.bklog_u,
2498 			xprt->stat.max_slots,
2499 			xprt->stat.sending_u,
2500 			xprt->stat.pending_u);
2501 }
2502 
2503 /*
2504  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2505  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2506  * to use the server side send routines.
2507  */
2508 static int bc_malloc(struct rpc_task *task)
2509 {
2510 	struct rpc_rqst *rqst = task->tk_rqstp;
2511 	size_t size = rqst->rq_callsize;
2512 	struct page *page;
2513 	struct rpc_buffer *buf;
2514 
2515 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2516 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2517 			  size);
2518 		return -EINVAL;
2519 	}
2520 
2521 	page = alloc_page(GFP_KERNEL);
2522 	if (!page)
2523 		return -ENOMEM;
2524 
2525 	buf = page_address(page);
2526 	buf->len = PAGE_SIZE;
2527 
2528 	rqst->rq_buffer = buf->data;
2529 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2530 	return 0;
2531 }
2532 
2533 /*
2534  * Free the space allocated in the bc_alloc routine
2535  */
2536 static void bc_free(struct rpc_task *task)
2537 {
2538 	void *buffer = task->tk_rqstp->rq_buffer;
2539 	struct rpc_buffer *buf;
2540 
2541 	buf = container_of(buffer, struct rpc_buffer, data);
2542 	free_page((unsigned long)buf);
2543 }
2544 
2545 static int bc_sendto(struct rpc_rqst *req)
2546 {
2547 	struct xdr_buf *xdr = &req->rq_snd_buf;
2548 	struct sock_xprt *transport =
2549 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2550 	struct msghdr msg = {
2551 		.msg_flags	= 0,
2552 	};
2553 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2554 					 (u32)xdr->len);
2555 	unsigned int sent = 0;
2556 	int err;
2557 
2558 	req->rq_xtime = ktime_get();
2559 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2560 	xdr_free_bvec(xdr);
2561 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2562 		return -EAGAIN;
2563 	return sent;
2564 }
2565 
2566 /**
2567  * bc_send_request - Send a backchannel Call on a TCP socket
2568  * @req: rpc_rqst containing Call message to be sent
2569  *
2570  * xpt_mutex ensures @rqstp's whole message is written to the socket
2571  * without interruption.
2572  *
2573  * Return values:
2574  *   %0 if the message was sent successfully
2575  *   %ENOTCONN if the message was not sent
2576  */
2577 static int bc_send_request(struct rpc_rqst *req)
2578 {
2579 	struct svc_xprt	*xprt;
2580 	int len;
2581 
2582 	/*
2583 	 * Get the server socket associated with this callback xprt
2584 	 */
2585 	xprt = req->rq_xprt->bc_xprt;
2586 
2587 	/*
2588 	 * Grab the mutex to serialize data as the connection is shared
2589 	 * with the fore channel
2590 	 */
2591 	mutex_lock(&xprt->xpt_mutex);
2592 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2593 		len = -ENOTCONN;
2594 	else
2595 		len = bc_sendto(req);
2596 	mutex_unlock(&xprt->xpt_mutex);
2597 
2598 	if (len > 0)
2599 		len = 0;
2600 
2601 	return len;
2602 }
2603 
2604 /*
2605  * The close routine. Since this is client initiated, we do nothing
2606  */
2607 
2608 static void bc_close(struct rpc_xprt *xprt)
2609 {
2610 	xprt_disconnect_done(xprt);
2611 }
2612 
2613 /*
2614  * The xprt destroy routine. Again, because this connection is client
2615  * initiated, we do nothing
2616  */
2617 
2618 static void bc_destroy(struct rpc_xprt *xprt)
2619 {
2620 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2621 
2622 	xs_xprt_free(xprt);
2623 	module_put(THIS_MODULE);
2624 }
2625 
2626 static const struct rpc_xprt_ops xs_local_ops = {
2627 	.reserve_xprt		= xprt_reserve_xprt,
2628 	.release_xprt		= xprt_release_xprt,
2629 	.alloc_slot		= xprt_alloc_slot,
2630 	.free_slot		= xprt_free_slot,
2631 	.rpcbind		= xs_local_rpcbind,
2632 	.set_port		= xs_local_set_port,
2633 	.connect		= xs_local_connect,
2634 	.buf_alloc		= rpc_malloc,
2635 	.buf_free		= rpc_free,
2636 	.prepare_request	= xs_stream_prepare_request,
2637 	.send_request		= xs_local_send_request,
2638 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2639 	.close			= xs_close,
2640 	.destroy		= xs_destroy,
2641 	.print_stats		= xs_local_print_stats,
2642 	.enable_swap		= xs_enable_swap,
2643 	.disable_swap		= xs_disable_swap,
2644 };
2645 
2646 static const struct rpc_xprt_ops xs_udp_ops = {
2647 	.set_buffer_size	= xs_udp_set_buffer_size,
2648 	.reserve_xprt		= xprt_reserve_xprt_cong,
2649 	.release_xprt		= xprt_release_xprt_cong,
2650 	.alloc_slot		= xprt_alloc_slot,
2651 	.free_slot		= xprt_free_slot,
2652 	.rpcbind		= rpcb_getport_async,
2653 	.set_port		= xs_set_port,
2654 	.connect		= xs_connect,
2655 	.buf_alloc		= rpc_malloc,
2656 	.buf_free		= rpc_free,
2657 	.send_request		= xs_udp_send_request,
2658 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2659 	.timer			= xs_udp_timer,
2660 	.release_request	= xprt_release_rqst_cong,
2661 	.close			= xs_close,
2662 	.destroy		= xs_destroy,
2663 	.print_stats		= xs_udp_print_stats,
2664 	.enable_swap		= xs_enable_swap,
2665 	.disable_swap		= xs_disable_swap,
2666 	.inject_disconnect	= xs_inject_disconnect,
2667 };
2668 
2669 static const struct rpc_xprt_ops xs_tcp_ops = {
2670 	.reserve_xprt		= xprt_reserve_xprt,
2671 	.release_xprt		= xprt_release_xprt,
2672 	.alloc_slot		= xprt_alloc_slot,
2673 	.free_slot		= xprt_free_slot,
2674 	.rpcbind		= rpcb_getport_async,
2675 	.set_port		= xs_set_port,
2676 	.connect		= xs_connect,
2677 	.buf_alloc		= rpc_malloc,
2678 	.buf_free		= rpc_free,
2679 	.prepare_request	= xs_stream_prepare_request,
2680 	.send_request		= xs_tcp_send_request,
2681 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2682 	.close			= xs_tcp_shutdown,
2683 	.destroy		= xs_destroy,
2684 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2685 	.print_stats		= xs_tcp_print_stats,
2686 	.enable_swap		= xs_enable_swap,
2687 	.disable_swap		= xs_disable_swap,
2688 	.inject_disconnect	= xs_inject_disconnect,
2689 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2690 	.bc_setup		= xprt_setup_bc,
2691 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2692 	.bc_num_slots		= xprt_bc_max_slots,
2693 	.bc_free_rqst		= xprt_free_bc_rqst,
2694 	.bc_destroy		= xprt_destroy_bc,
2695 #endif
2696 };
2697 
2698 /*
2699  * The rpc_xprt_ops for the server backchannel
2700  */
2701 
2702 static const struct rpc_xprt_ops bc_tcp_ops = {
2703 	.reserve_xprt		= xprt_reserve_xprt,
2704 	.release_xprt		= xprt_release_xprt,
2705 	.alloc_slot		= xprt_alloc_slot,
2706 	.free_slot		= xprt_free_slot,
2707 	.buf_alloc		= bc_malloc,
2708 	.buf_free		= bc_free,
2709 	.send_request		= bc_send_request,
2710 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2711 	.close			= bc_close,
2712 	.destroy		= bc_destroy,
2713 	.print_stats		= xs_tcp_print_stats,
2714 	.enable_swap		= xs_enable_swap,
2715 	.disable_swap		= xs_disable_swap,
2716 	.inject_disconnect	= xs_inject_disconnect,
2717 };
2718 
2719 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2720 {
2721 	static const struct sockaddr_in sin = {
2722 		.sin_family		= AF_INET,
2723 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2724 	};
2725 	static const struct sockaddr_in6 sin6 = {
2726 		.sin6_family		= AF_INET6,
2727 		.sin6_addr		= IN6ADDR_ANY_INIT,
2728 	};
2729 
2730 	switch (family) {
2731 	case AF_LOCAL:
2732 		break;
2733 	case AF_INET:
2734 		memcpy(sap, &sin, sizeof(sin));
2735 		break;
2736 	case AF_INET6:
2737 		memcpy(sap, &sin6, sizeof(sin6));
2738 		break;
2739 	default:
2740 		dprintk("RPC:       %s: Bad address family\n", __func__);
2741 		return -EAFNOSUPPORT;
2742 	}
2743 	return 0;
2744 }
2745 
2746 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2747 				      unsigned int slot_table_size,
2748 				      unsigned int max_slot_table_size)
2749 {
2750 	struct rpc_xprt *xprt;
2751 	struct sock_xprt *new;
2752 
2753 	if (args->addrlen > sizeof(xprt->addr)) {
2754 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2755 		return ERR_PTR(-EBADF);
2756 	}
2757 
2758 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2759 			max_slot_table_size);
2760 	if (xprt == NULL) {
2761 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2762 				"rpc_xprt\n");
2763 		return ERR_PTR(-ENOMEM);
2764 	}
2765 
2766 	new = container_of(xprt, struct sock_xprt, xprt);
2767 	mutex_init(&new->recv_mutex);
2768 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2769 	xprt->addrlen = args->addrlen;
2770 	if (args->srcaddr)
2771 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2772 	else {
2773 		int err;
2774 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2775 					(struct sockaddr *)&new->srcaddr);
2776 		if (err != 0) {
2777 			xprt_free(xprt);
2778 			return ERR_PTR(err);
2779 		}
2780 	}
2781 
2782 	return xprt;
2783 }
2784 
2785 static const struct rpc_timeout xs_local_default_timeout = {
2786 	.to_initval = 10 * HZ,
2787 	.to_maxval = 10 * HZ,
2788 	.to_retries = 2,
2789 };
2790 
2791 /**
2792  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2793  * @args: rpc transport creation arguments
2794  *
2795  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2796  */
2797 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2798 {
2799 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2800 	struct sock_xprt *transport;
2801 	struct rpc_xprt *xprt;
2802 	struct rpc_xprt *ret;
2803 
2804 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2805 			xprt_max_tcp_slot_table_entries);
2806 	if (IS_ERR(xprt))
2807 		return xprt;
2808 	transport = container_of(xprt, struct sock_xprt, xprt);
2809 
2810 	xprt->prot = 0;
2811 	xprt->xprt_class = &xs_local_transport;
2812 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2813 
2814 	xprt->bind_timeout = XS_BIND_TO;
2815 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2816 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2817 
2818 	xprt->ops = &xs_local_ops;
2819 	xprt->timeout = &xs_local_default_timeout;
2820 
2821 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2822 	INIT_WORK(&transport->error_worker, xs_error_handle);
2823 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2824 
2825 	switch (sun->sun_family) {
2826 	case AF_LOCAL:
2827 		if (sun->sun_path[0] != '/') {
2828 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2829 					sun->sun_path);
2830 			ret = ERR_PTR(-EINVAL);
2831 			goto out_err;
2832 		}
2833 		xprt_set_bound(xprt);
2834 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2835 		ret = ERR_PTR(xs_local_setup_socket(transport));
2836 		if (ret)
2837 			goto out_err;
2838 		break;
2839 	default:
2840 		ret = ERR_PTR(-EAFNOSUPPORT);
2841 		goto out_err;
2842 	}
2843 
2844 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2845 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2846 
2847 	if (try_module_get(THIS_MODULE))
2848 		return xprt;
2849 	ret = ERR_PTR(-EINVAL);
2850 out_err:
2851 	xs_xprt_free(xprt);
2852 	return ret;
2853 }
2854 
2855 static const struct rpc_timeout xs_udp_default_timeout = {
2856 	.to_initval = 5 * HZ,
2857 	.to_maxval = 30 * HZ,
2858 	.to_increment = 5 * HZ,
2859 	.to_retries = 5,
2860 };
2861 
2862 /**
2863  * xs_setup_udp - Set up transport to use a UDP socket
2864  * @args: rpc transport creation arguments
2865  *
2866  */
2867 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2868 {
2869 	struct sockaddr *addr = args->dstaddr;
2870 	struct rpc_xprt *xprt;
2871 	struct sock_xprt *transport;
2872 	struct rpc_xprt *ret;
2873 
2874 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2875 			xprt_udp_slot_table_entries);
2876 	if (IS_ERR(xprt))
2877 		return xprt;
2878 	transport = container_of(xprt, struct sock_xprt, xprt);
2879 
2880 	xprt->prot = IPPROTO_UDP;
2881 	xprt->xprt_class = &xs_udp_transport;
2882 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2883 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2884 
2885 	xprt->bind_timeout = XS_BIND_TO;
2886 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2887 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2888 
2889 	xprt->ops = &xs_udp_ops;
2890 
2891 	xprt->timeout = &xs_udp_default_timeout;
2892 
2893 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2894 	INIT_WORK(&transport->error_worker, xs_error_handle);
2895 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2896 
2897 	switch (addr->sa_family) {
2898 	case AF_INET:
2899 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2900 			xprt_set_bound(xprt);
2901 
2902 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2903 		break;
2904 	case AF_INET6:
2905 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2906 			xprt_set_bound(xprt);
2907 
2908 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2909 		break;
2910 	default:
2911 		ret = ERR_PTR(-EAFNOSUPPORT);
2912 		goto out_err;
2913 	}
2914 
2915 	if (xprt_bound(xprt))
2916 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2917 				xprt->address_strings[RPC_DISPLAY_ADDR],
2918 				xprt->address_strings[RPC_DISPLAY_PORT],
2919 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2920 	else
2921 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2922 				xprt->address_strings[RPC_DISPLAY_ADDR],
2923 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2924 
2925 	if (try_module_get(THIS_MODULE))
2926 		return xprt;
2927 	ret = ERR_PTR(-EINVAL);
2928 out_err:
2929 	xs_xprt_free(xprt);
2930 	return ret;
2931 }
2932 
2933 static const struct rpc_timeout xs_tcp_default_timeout = {
2934 	.to_initval = 60 * HZ,
2935 	.to_maxval = 60 * HZ,
2936 	.to_retries = 2,
2937 };
2938 
2939 /**
2940  * xs_setup_tcp - Set up transport to use a TCP socket
2941  * @args: rpc transport creation arguments
2942  *
2943  */
2944 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2945 {
2946 	struct sockaddr *addr = args->dstaddr;
2947 	struct rpc_xprt *xprt;
2948 	struct sock_xprt *transport;
2949 	struct rpc_xprt *ret;
2950 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2951 
2952 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2953 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2954 
2955 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2956 			max_slot_table_size);
2957 	if (IS_ERR(xprt))
2958 		return xprt;
2959 	transport = container_of(xprt, struct sock_xprt, xprt);
2960 
2961 	xprt->prot = IPPROTO_TCP;
2962 	xprt->xprt_class = &xs_tcp_transport;
2963 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2964 
2965 	xprt->bind_timeout = XS_BIND_TO;
2966 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2967 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2968 
2969 	xprt->ops = &xs_tcp_ops;
2970 	xprt->timeout = &xs_tcp_default_timeout;
2971 
2972 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2973 	xprt->connect_timeout = xprt->timeout->to_initval *
2974 		(xprt->timeout->to_retries + 1);
2975 
2976 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2977 	INIT_WORK(&transport->error_worker, xs_error_handle);
2978 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2979 
2980 	switch (addr->sa_family) {
2981 	case AF_INET:
2982 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2983 			xprt_set_bound(xprt);
2984 
2985 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2986 		break;
2987 	case AF_INET6:
2988 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2989 			xprt_set_bound(xprt);
2990 
2991 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2992 		break;
2993 	default:
2994 		ret = ERR_PTR(-EAFNOSUPPORT);
2995 		goto out_err;
2996 	}
2997 
2998 	if (xprt_bound(xprt))
2999 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3000 				xprt->address_strings[RPC_DISPLAY_ADDR],
3001 				xprt->address_strings[RPC_DISPLAY_PORT],
3002 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3003 	else
3004 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3005 				xprt->address_strings[RPC_DISPLAY_ADDR],
3006 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3007 
3008 	if (try_module_get(THIS_MODULE))
3009 		return xprt;
3010 	ret = ERR_PTR(-EINVAL);
3011 out_err:
3012 	xs_xprt_free(xprt);
3013 	return ret;
3014 }
3015 
3016 /**
3017  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3018  * @args: rpc transport creation arguments
3019  *
3020  */
3021 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3022 {
3023 	struct sockaddr *addr = args->dstaddr;
3024 	struct rpc_xprt *xprt;
3025 	struct sock_xprt *transport;
3026 	struct svc_sock *bc_sock;
3027 	struct rpc_xprt *ret;
3028 
3029 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3030 			xprt_tcp_slot_table_entries);
3031 	if (IS_ERR(xprt))
3032 		return xprt;
3033 	transport = container_of(xprt, struct sock_xprt, xprt);
3034 
3035 	xprt->prot = IPPROTO_TCP;
3036 	xprt->xprt_class = &xs_bc_tcp_transport;
3037 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3038 	xprt->timeout = &xs_tcp_default_timeout;
3039 
3040 	/* backchannel */
3041 	xprt_set_bound(xprt);
3042 	xprt->bind_timeout = 0;
3043 	xprt->reestablish_timeout = 0;
3044 	xprt->idle_timeout = 0;
3045 
3046 	xprt->ops = &bc_tcp_ops;
3047 
3048 	switch (addr->sa_family) {
3049 	case AF_INET:
3050 		xs_format_peer_addresses(xprt, "tcp",
3051 					 RPCBIND_NETID_TCP);
3052 		break;
3053 	case AF_INET6:
3054 		xs_format_peer_addresses(xprt, "tcp",
3055 				   RPCBIND_NETID_TCP6);
3056 		break;
3057 	default:
3058 		ret = ERR_PTR(-EAFNOSUPPORT);
3059 		goto out_err;
3060 	}
3061 
3062 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3063 			xprt->address_strings[RPC_DISPLAY_ADDR],
3064 			xprt->address_strings[RPC_DISPLAY_PORT],
3065 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3066 
3067 	/*
3068 	 * Once we've associated a backchannel xprt with a connection,
3069 	 * we want to keep it around as long as the connection lasts,
3070 	 * in case we need to start using it for a backchannel again;
3071 	 * this reference won't be dropped until bc_xprt is destroyed.
3072 	 */
3073 	xprt_get(xprt);
3074 	args->bc_xprt->xpt_bc_xprt = xprt;
3075 	xprt->bc_xprt = args->bc_xprt;
3076 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3077 	transport->sock = bc_sock->sk_sock;
3078 	transport->inet = bc_sock->sk_sk;
3079 
3080 	/*
3081 	 * Since we don't want connections for the backchannel, we set
3082 	 * the xprt status to connected
3083 	 */
3084 	xprt_set_connected(xprt);
3085 
3086 	if (try_module_get(THIS_MODULE))
3087 		return xprt;
3088 
3089 	args->bc_xprt->xpt_bc_xprt = NULL;
3090 	args->bc_xprt->xpt_bc_xps = NULL;
3091 	xprt_put(xprt);
3092 	ret = ERR_PTR(-EINVAL);
3093 out_err:
3094 	xs_xprt_free(xprt);
3095 	return ret;
3096 }
3097 
3098 static struct xprt_class	xs_local_transport = {
3099 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3100 	.name		= "named UNIX socket",
3101 	.owner		= THIS_MODULE,
3102 	.ident		= XPRT_TRANSPORT_LOCAL,
3103 	.setup		= xs_setup_local,
3104 	.netid		= { "" },
3105 };
3106 
3107 static struct xprt_class	xs_udp_transport = {
3108 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3109 	.name		= "udp",
3110 	.owner		= THIS_MODULE,
3111 	.ident		= XPRT_TRANSPORT_UDP,
3112 	.setup		= xs_setup_udp,
3113 	.netid		= { "udp", "udp6", "" },
3114 };
3115 
3116 static struct xprt_class	xs_tcp_transport = {
3117 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3118 	.name		= "tcp",
3119 	.owner		= THIS_MODULE,
3120 	.ident		= XPRT_TRANSPORT_TCP,
3121 	.setup		= xs_setup_tcp,
3122 	.netid		= { "tcp", "tcp6", "" },
3123 };
3124 
3125 static struct xprt_class	xs_bc_tcp_transport = {
3126 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3127 	.name		= "tcp NFSv4.1 backchannel",
3128 	.owner		= THIS_MODULE,
3129 	.ident		= XPRT_TRANSPORT_BC_TCP,
3130 	.setup		= xs_setup_bc_tcp,
3131 	.netid		= { "" },
3132 };
3133 
3134 /**
3135  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3136  *
3137  */
3138 int init_socket_xprt(void)
3139 {
3140 	if (!sunrpc_table_header)
3141 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3142 
3143 	xprt_register_transport(&xs_local_transport);
3144 	xprt_register_transport(&xs_udp_transport);
3145 	xprt_register_transport(&xs_tcp_transport);
3146 	xprt_register_transport(&xs_bc_tcp_transport);
3147 
3148 	return 0;
3149 }
3150 
3151 /**
3152  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3153  *
3154  */
3155 void cleanup_socket_xprt(void)
3156 {
3157 	if (sunrpc_table_header) {
3158 		unregister_sysctl_table(sunrpc_table_header);
3159 		sunrpc_table_header = NULL;
3160 	}
3161 
3162 	xprt_unregister_transport(&xs_local_transport);
3163 	xprt_unregister_transport(&xs_udp_transport);
3164 	xprt_unregister_transport(&xs_tcp_transport);
3165 	xprt_unregister_transport(&xs_bc_tcp_transport);
3166 }
3167 
3168 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3169 {
3170 	return param_set_uint_minmax(val, kp,
3171 			RPC_MIN_RESVPORT,
3172 			RPC_MAX_RESVPORT);
3173 }
3174 
3175 static const struct kernel_param_ops param_ops_portnr = {
3176 	.set = param_set_portnr,
3177 	.get = param_get_uint,
3178 };
3179 
3180 #define param_check_portnr(name, p) \
3181 	__param_check(name, p, unsigned int);
3182 
3183 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3184 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3185 
3186 static int param_set_slot_table_size(const char *val,
3187 				     const struct kernel_param *kp)
3188 {
3189 	return param_set_uint_minmax(val, kp,
3190 			RPC_MIN_SLOT_TABLE,
3191 			RPC_MAX_SLOT_TABLE);
3192 }
3193 
3194 static const struct kernel_param_ops param_ops_slot_table_size = {
3195 	.set = param_set_slot_table_size,
3196 	.get = param_get_uint,
3197 };
3198 
3199 #define param_check_slot_table_size(name, p) \
3200 	__param_check(name, p, unsigned int);
3201 
3202 static int param_set_max_slot_table_size(const char *val,
3203 				     const struct kernel_param *kp)
3204 {
3205 	return param_set_uint_minmax(val, kp,
3206 			RPC_MIN_SLOT_TABLE,
3207 			RPC_MAX_SLOT_TABLE_LIMIT);
3208 }
3209 
3210 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3211 	.set = param_set_max_slot_table_size,
3212 	.get = param_get_uint,
3213 };
3214 
3215 #define param_check_max_slot_table_size(name, p) \
3216 	__param_check(name, p, unsigned int);
3217 
3218 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3219 		   slot_table_size, 0644);
3220 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3221 		   max_slot_table_size, 0644);
3222 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3223 		   slot_table_size, 0644);
3224