xref: /linux/net/sunrpc/xprtsock.c (revision 8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88)
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 <net/tls_prot.h>
51 #include <net/handshake.h>
52 
53 #include <linux/bvec.h>
54 #include <linux/highmem.h>
55 #include <linux/uio.h>
56 #include <linux/sched/mm.h>
57 
58 #include <trace/events/sock.h>
59 #include <trace/events/sunrpc.h>
60 
61 #include "socklib.h"
62 #include "sunrpc.h"
63 
64 static void xs_close(struct rpc_xprt *xprt);
65 static void xs_reset_srcport(struct sock_xprt *transport);
66 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock);
67 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
68 		struct socket *sock);
69 
70 /*
71  * xprtsock tunables
72  */
73 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
74 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
75 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
76 
77 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
78 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
79 
80 #define XS_TCP_LINGER_TO	(15U * HZ)
81 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
82 
83 /*
84  * We can register our own files under /proc/sys/sunrpc by
85  * calling register_sysctl() again.  The files in that
86  * directory become the union of all files registered there.
87  *
88  * We simply need to make sure that we don't collide with
89  * someone else's file names!
90  */
91 
92 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
93 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
94 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
95 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
96 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
97 
98 static struct ctl_table_header *sunrpc_table_header;
99 
100 static struct xprt_class xs_local_transport;
101 static struct xprt_class xs_udp_transport;
102 static struct xprt_class xs_tcp_transport;
103 static struct xprt_class xs_tcp_tls_transport;
104 static struct xprt_class xs_bc_tcp_transport;
105 
106 /*
107  * FIXME: changing the UDP slot table size should also resize the UDP
108  *        socket buffers for existing UDP transports
109  */
110 static struct ctl_table xs_tunables_table[] = {
111 	{
112 		.procname	= "udp_slot_table_entries",
113 		.data		= &xprt_udp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_slot_table_size
119 	},
120 	{
121 		.procname	= "tcp_slot_table_entries",
122 		.data		= &xprt_tcp_slot_table_entries,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &min_slot_table_size,
127 		.extra2		= &max_slot_table_size
128 	},
129 	{
130 		.procname	= "tcp_max_slot_table_entries",
131 		.data		= &xprt_max_tcp_slot_table_entries,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &min_slot_table_size,
136 		.extra2		= &max_tcp_slot_table_limit
137 	},
138 	{
139 		.procname	= "min_resvport",
140 		.data		= &xprt_min_resvport,
141 		.maxlen		= sizeof(unsigned int),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_minmax,
144 		.extra1		= &xprt_min_resvport_limit,
145 		.extra2		= &xprt_max_resvport_limit
146 	},
147 	{
148 		.procname	= "max_resvport",
149 		.data		= &xprt_max_resvport,
150 		.maxlen		= sizeof(unsigned int),
151 		.mode		= 0644,
152 		.proc_handler	= proc_dointvec_minmax,
153 		.extra1		= &xprt_min_resvport_limit,
154 		.extra2		= &xprt_max_resvport_limit
155 	},
156 	{
157 		.procname	= "tcp_fin_timeout",
158 		.data		= &xs_tcp_fin_timeout,
159 		.maxlen		= sizeof(xs_tcp_fin_timeout),
160 		.mode		= 0644,
161 		.proc_handler	= proc_dointvec_jiffies,
162 	},
163 };
164 
165 /*
166  * Wait duration for a reply from the RPC portmapper.
167  */
168 #define XS_BIND_TO		(60U * HZ)
169 
170 /*
171  * Delay if a UDP socket connect error occurs.  This is most likely some
172  * kind of resource problem on the local host.
173  */
174 #define XS_UDP_REEST_TO		(2U * HZ)
175 
176 /*
177  * The reestablish timeout allows clients to delay for a bit before attempting
178  * to reconnect to a server that just dropped our connection.
179  *
180  * We implement an exponential backoff when trying to reestablish a TCP
181  * transport connection with the server.  Some servers like to drop a TCP
182  * connection when they are overworked, so we start with a short timeout and
183  * increase over time if the server is down or not responding.
184  */
185 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
186 
187 /*
188  * TCP idle timeout; client drops the transport socket if it is idle
189  * for this long.  Note that we also timeout UDP sockets to prevent
190  * holding port numbers when there is no RPC traffic.
191  */
192 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
193 
194 /*
195  * TLS handshake timeout.
196  */
197 #define XS_TLS_HANDSHAKE_TO	(10U * HZ)
198 
199 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
200 # undef  RPC_DEBUG_DATA
201 # define RPCDBG_FACILITY	RPCDBG_TRANS
202 #endif
203 
204 #ifdef RPC_DEBUG_DATA
205 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
206 {
207 	u8 *buf = (u8 *) packet;
208 	int j;
209 
210 	dprintk("RPC:       %s\n", msg);
211 	for (j = 0; j < count && j < 128; j += 4) {
212 		if (!(j & 31)) {
213 			if (j)
214 				dprintk("\n");
215 			dprintk("0x%04x ", j);
216 		}
217 		dprintk("%02x%02x%02x%02x ",
218 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
219 	}
220 	dprintk("\n");
221 }
222 #else
223 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
224 {
225 	/* NOP */
226 }
227 #endif
228 
229 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
230 {
231 	return (struct rpc_xprt *) sk->sk_user_data;
232 }
233 
234 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
235 {
236 	return (struct sockaddr *) &xprt->addr;
237 }
238 
239 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
240 {
241 	return (struct sockaddr_un *) &xprt->addr;
242 }
243 
244 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
245 {
246 	return (struct sockaddr_in *) &xprt->addr;
247 }
248 
249 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
250 {
251 	return (struct sockaddr_in6 *) &xprt->addr;
252 }
253 
254 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
255 {
256 	struct sockaddr *sap = xs_addr(xprt);
257 	struct sockaddr_in6 *sin6;
258 	struct sockaddr_in *sin;
259 	struct sockaddr_un *sun;
260 	char buf[128];
261 
262 	switch (sap->sa_family) {
263 	case AF_LOCAL:
264 		sun = xs_addr_un(xprt);
265 		if (sun->sun_path[0]) {
266 			strscpy(buf, sun->sun_path, sizeof(buf));
267 		} else {
268 			buf[0] = '@';
269 			strscpy(buf+1, sun->sun_path+1, sizeof(buf)-1);
270 		}
271 		xprt->address_strings[RPC_DISPLAY_ADDR] =
272 						kstrdup(buf, GFP_KERNEL);
273 		break;
274 	case AF_INET:
275 		(void)rpc_ntop(sap, buf, sizeof(buf));
276 		xprt->address_strings[RPC_DISPLAY_ADDR] =
277 						kstrdup(buf, GFP_KERNEL);
278 		sin = xs_addr_in(xprt);
279 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
280 		break;
281 	case AF_INET6:
282 		(void)rpc_ntop(sap, buf, sizeof(buf));
283 		xprt->address_strings[RPC_DISPLAY_ADDR] =
284 						kstrdup(buf, GFP_KERNEL);
285 		sin6 = xs_addr_in6(xprt);
286 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
287 		break;
288 	default:
289 		BUG();
290 	}
291 
292 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
293 }
294 
295 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
296 {
297 	struct sockaddr *sap = xs_addr(xprt);
298 	char buf[128];
299 
300 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
301 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
302 
303 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
304 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
305 }
306 
307 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
308 				     const char *protocol,
309 				     const char *netid)
310 {
311 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
312 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
313 	xs_format_common_peer_addresses(xprt);
314 	xs_format_common_peer_ports(xprt);
315 }
316 
317 static void xs_update_peer_port(struct rpc_xprt *xprt)
318 {
319 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
320 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
321 
322 	xs_format_common_peer_ports(xprt);
323 }
324 
325 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
326 {
327 	unsigned int i;
328 
329 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
330 		switch (i) {
331 		case RPC_DISPLAY_PROTO:
332 		case RPC_DISPLAY_NETID:
333 			continue;
334 		default:
335 			kfree(xprt->address_strings[i]);
336 		}
337 }
338 
339 static size_t
340 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
341 {
342 	size_t i,n;
343 
344 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
345 		return want;
346 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
347 	for (i = 0; i < n; i++) {
348 		if (buf->pages[i])
349 			continue;
350 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
351 		if (!buf->pages[i]) {
352 			i *= PAGE_SIZE;
353 			return i > buf->page_base ? i - buf->page_base : 0;
354 		}
355 	}
356 	return want;
357 }
358 
359 static int
360 xs_sock_process_cmsg(struct socket *sock, struct msghdr *msg,
361 		     unsigned int *msg_flags, struct cmsghdr *cmsg, int ret)
362 {
363 	u8 content_type = tls_get_record_type(sock->sk, cmsg);
364 	u8 level, description;
365 
366 	switch (content_type) {
367 	case 0:
368 		break;
369 	case TLS_RECORD_TYPE_DATA:
370 		/* TLS sets EOR at the end of each application data
371 		 * record, even though there might be more frames
372 		 * waiting to be decrypted.
373 		 */
374 		*msg_flags &= ~MSG_EOR;
375 		break;
376 	case TLS_RECORD_TYPE_ALERT:
377 		tls_alert_recv(sock->sk, msg, &level, &description);
378 		ret = (level == TLS_ALERT_LEVEL_FATAL) ?
379 			-EACCES : -EAGAIN;
380 		break;
381 	default:
382 		/* discard this record type */
383 		ret = -EAGAIN;
384 	}
385 	return ret;
386 }
387 
388 static int
389 xs_sock_recv_cmsg(struct socket *sock, unsigned int *msg_flags, int flags)
390 {
391 	union {
392 		struct cmsghdr	cmsg;
393 		u8		buf[CMSG_SPACE(sizeof(u8))];
394 	} u;
395 	u8 alert[2];
396 	struct kvec alert_kvec = {
397 		.iov_base = alert,
398 		.iov_len = sizeof(alert),
399 	};
400 	struct msghdr msg = {
401 		.msg_flags = *msg_flags,
402 		.msg_control = &u,
403 		.msg_controllen = sizeof(u),
404 	};
405 	int ret;
406 
407 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &alert_kvec, 1,
408 		      alert_kvec.iov_len);
409 	ret = sock_recvmsg(sock, &msg, flags);
410 	if (ret > 0) {
411 		if (tls_get_record_type(sock->sk, &u.cmsg) == TLS_RECORD_TYPE_ALERT)
412 			iov_iter_revert(&msg.msg_iter, ret);
413 		ret = xs_sock_process_cmsg(sock, &msg, msg_flags, &u.cmsg,
414 					   -EAGAIN);
415 	}
416 	return ret;
417 }
418 
419 static ssize_t
420 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
421 {
422 	ssize_t ret;
423 	if (seek != 0)
424 		iov_iter_advance(&msg->msg_iter, seek);
425 	ret = sock_recvmsg(sock, msg, flags);
426 	/* Handle TLS inband control message lazily */
427 	if (msg->msg_flags & MSG_CTRUNC) {
428 		msg->msg_flags &= ~(MSG_CTRUNC | MSG_EOR);
429 		if (ret == 0 || ret == -EIO)
430 			ret = xs_sock_recv_cmsg(sock, &msg->msg_flags, flags);
431 	}
432 	return ret > 0 ? ret + seek : ret;
433 }
434 
435 static ssize_t
436 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
437 		struct kvec *kvec, size_t count, size_t seek)
438 {
439 	iov_iter_kvec(&msg->msg_iter, ITER_DEST, kvec, 1, count);
440 	return xs_sock_recvmsg(sock, msg, flags, seek);
441 }
442 
443 static ssize_t
444 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
445 		struct bio_vec *bvec, unsigned long nr, size_t count,
446 		size_t seek)
447 {
448 	iov_iter_bvec(&msg->msg_iter, ITER_DEST, bvec, nr, count);
449 	return xs_sock_recvmsg(sock, msg, flags, seek);
450 }
451 
452 static ssize_t
453 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
454 		size_t count)
455 {
456 	iov_iter_discard(&msg->msg_iter, ITER_DEST, count);
457 	return xs_sock_recvmsg(sock, msg, flags, 0);
458 }
459 
460 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
461 static void
462 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
463 {
464 	struct bvec_iter bi = {
465 		.bi_size = count,
466 	};
467 	struct bio_vec bv;
468 
469 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
470 	for_each_bvec(bv, bvec, bi, bi)
471 		flush_dcache_page(bv.bv_page);
472 }
473 #else
474 static inline void
475 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
476 {
477 }
478 #endif
479 
480 static ssize_t
481 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
482 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
483 {
484 	size_t want, seek_init = seek, offset = 0;
485 	ssize_t ret;
486 
487 	want = min_t(size_t, count, buf->head[0].iov_len);
488 	if (seek < want) {
489 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
490 		if (ret <= 0)
491 			goto sock_err;
492 		offset += ret;
493 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
494 			goto out;
495 		if (ret != want)
496 			goto out;
497 		seek = 0;
498 	} else {
499 		seek -= want;
500 		offset += want;
501 	}
502 
503 	want = xs_alloc_sparse_pages(
504 		buf, min_t(size_t, count - offset, buf->page_len),
505 		GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
506 	if (seek < want) {
507 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
508 				xdr_buf_pagecount(buf),
509 				want + buf->page_base,
510 				seek + buf->page_base);
511 		if (ret <= 0)
512 			goto sock_err;
513 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
514 		ret -= buf->page_base;
515 		offset += ret;
516 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
517 			goto out;
518 		if (ret != want)
519 			goto out;
520 		seek = 0;
521 	} else {
522 		seek -= want;
523 		offset += want;
524 	}
525 
526 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
527 	if (seek < want) {
528 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
529 		if (ret <= 0)
530 			goto sock_err;
531 		offset += ret;
532 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
533 			goto out;
534 		if (ret != want)
535 			goto out;
536 	} else if (offset < seek_init)
537 		offset = seek_init;
538 	ret = -EMSGSIZE;
539 out:
540 	*read = offset - seek_init;
541 	return ret;
542 sock_err:
543 	offset += seek;
544 	goto out;
545 }
546 
547 static void
548 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
549 {
550 	if (!transport->recv.copied) {
551 		if (buf->head[0].iov_len >= transport->recv.offset)
552 			memcpy(buf->head[0].iov_base,
553 					&transport->recv.xid,
554 					transport->recv.offset);
555 		transport->recv.copied = transport->recv.offset;
556 	}
557 }
558 
559 static bool
560 xs_read_stream_request_done(struct sock_xprt *transport)
561 {
562 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
563 }
564 
565 static void
566 xs_read_stream_check_eor(struct sock_xprt *transport,
567 		struct msghdr *msg)
568 {
569 	if (xs_read_stream_request_done(transport))
570 		msg->msg_flags |= MSG_EOR;
571 }
572 
573 static ssize_t
574 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
575 		int flags, struct rpc_rqst *req)
576 {
577 	struct xdr_buf *buf = &req->rq_private_buf;
578 	size_t want, read;
579 	ssize_t ret;
580 
581 	xs_read_header(transport, buf);
582 
583 	want = transport->recv.len - transport->recv.offset;
584 	if (want != 0) {
585 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
586 				transport->recv.copied + want,
587 				transport->recv.copied,
588 				&read);
589 		transport->recv.offset += read;
590 		transport->recv.copied += read;
591 	}
592 
593 	if (transport->recv.offset == transport->recv.len)
594 		xs_read_stream_check_eor(transport, msg);
595 
596 	if (want == 0)
597 		return 0;
598 
599 	switch (ret) {
600 	default:
601 		break;
602 	case -EFAULT:
603 	case -EMSGSIZE:
604 		msg->msg_flags |= MSG_TRUNC;
605 		return read;
606 	case 0:
607 		return -ESHUTDOWN;
608 	}
609 	return ret < 0 ? ret : read;
610 }
611 
612 static size_t
613 xs_read_stream_headersize(bool isfrag)
614 {
615 	if (isfrag)
616 		return sizeof(__be32);
617 	return 3 * sizeof(__be32);
618 }
619 
620 static ssize_t
621 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
622 		int flags, size_t want, size_t seek)
623 {
624 	struct kvec kvec = {
625 		.iov_base = &transport->recv.fraghdr,
626 		.iov_len = want,
627 	};
628 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
629 }
630 
631 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
632 static ssize_t
633 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
634 {
635 	struct rpc_xprt *xprt = &transport->xprt;
636 	struct rpc_rqst *req;
637 	ssize_t ret;
638 
639 	/* Is this transport associated with the backchannel? */
640 	if (!xprt->bc_serv)
641 		return -ESHUTDOWN;
642 
643 	/* Look up and lock the request corresponding to the given XID */
644 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
645 	if (!req) {
646 		printk(KERN_WARNING "Callback slot table overflowed\n");
647 		return -ESHUTDOWN;
648 	}
649 	if (transport->recv.copied && !req->rq_private_buf.len)
650 		return -ESHUTDOWN;
651 
652 	ret = xs_read_stream_request(transport, msg, flags, req);
653 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
654 		xprt_complete_bc_request(req, transport->recv.copied);
655 	else
656 		req->rq_private_buf.len = transport->recv.copied;
657 
658 	return ret;
659 }
660 #else /* CONFIG_SUNRPC_BACKCHANNEL */
661 static ssize_t
662 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
663 {
664 	return -ESHUTDOWN;
665 }
666 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
667 
668 static ssize_t
669 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
670 {
671 	struct rpc_xprt *xprt = &transport->xprt;
672 	struct rpc_rqst *req;
673 	ssize_t ret = 0;
674 
675 	/* Look up and lock the request corresponding to the given XID */
676 	spin_lock(&xprt->queue_lock);
677 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
678 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
679 		msg->msg_flags |= MSG_TRUNC;
680 		goto out;
681 	}
682 	xprt_pin_rqst(req);
683 	spin_unlock(&xprt->queue_lock);
684 
685 	ret = xs_read_stream_request(transport, msg, flags, req);
686 
687 	spin_lock(&xprt->queue_lock);
688 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
689 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
690 	else
691 		req->rq_private_buf.len = transport->recv.copied;
692 	xprt_unpin_rqst(req);
693 out:
694 	spin_unlock(&xprt->queue_lock);
695 	return ret;
696 }
697 
698 static ssize_t
699 xs_read_stream(struct sock_xprt *transport, int flags)
700 {
701 	struct msghdr msg = { 0 };
702 	size_t want, read = 0;
703 	ssize_t ret = 0;
704 
705 	if (transport->recv.len == 0) {
706 		want = xs_read_stream_headersize(transport->recv.copied != 0);
707 		ret = xs_read_stream_header(transport, &msg, flags, want,
708 				transport->recv.offset);
709 		if (ret <= 0)
710 			goto out_err;
711 		transport->recv.offset = ret;
712 		if (transport->recv.offset != want)
713 			return transport->recv.offset;
714 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
715 			RPC_FRAGMENT_SIZE_MASK;
716 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
717 		read = ret;
718 	}
719 
720 	switch (be32_to_cpu(transport->recv.calldir)) {
721 	default:
722 		msg.msg_flags |= MSG_TRUNC;
723 		break;
724 	case RPC_CALL:
725 		ret = xs_read_stream_call(transport, &msg, flags);
726 		break;
727 	case RPC_REPLY:
728 		ret = xs_read_stream_reply(transport, &msg, flags);
729 	}
730 	if (msg.msg_flags & MSG_TRUNC) {
731 		transport->recv.calldir = cpu_to_be32(-1);
732 		transport->recv.copied = -1;
733 	}
734 	if (ret < 0)
735 		goto out_err;
736 	read += ret;
737 	if (transport->recv.offset < transport->recv.len) {
738 		if (!(msg.msg_flags & MSG_TRUNC))
739 			return read;
740 		msg.msg_flags = 0;
741 		ret = xs_read_discard(transport->sock, &msg, flags,
742 				transport->recv.len - transport->recv.offset);
743 		if (ret <= 0)
744 			goto out_err;
745 		transport->recv.offset += ret;
746 		read += ret;
747 		if (transport->recv.offset != transport->recv.len)
748 			return read;
749 	}
750 	if (xs_read_stream_request_done(transport)) {
751 		trace_xs_stream_read_request(transport);
752 		transport->recv.copied = 0;
753 	}
754 	transport->recv.offset = 0;
755 	transport->recv.len = 0;
756 	return read;
757 out_err:
758 	return ret != 0 ? ret : -ESHUTDOWN;
759 }
760 
761 static __poll_t xs_poll_socket(struct sock_xprt *transport)
762 {
763 	return transport->sock->ops->poll(transport->file, transport->sock,
764 			NULL);
765 }
766 
767 static bool xs_poll_socket_readable(struct sock_xprt *transport)
768 {
769 	__poll_t events = xs_poll_socket(transport);
770 
771 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
772 }
773 
774 static void xs_poll_check_readable(struct sock_xprt *transport)
775 {
776 
777 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
778 	if (test_bit(XPRT_SOCK_IGNORE_RECV, &transport->sock_state))
779 		return;
780 	if (!xs_poll_socket_readable(transport))
781 		return;
782 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
783 		queue_work(xprtiod_workqueue, &transport->recv_worker);
784 }
785 
786 static void xs_stream_data_receive(struct sock_xprt *transport)
787 {
788 	size_t read = 0;
789 	ssize_t ret = 0;
790 
791 	mutex_lock(&transport->recv_mutex);
792 	if (transport->sock == NULL)
793 		goto out;
794 	for (;;) {
795 		ret = xs_read_stream(transport, MSG_DONTWAIT);
796 		if (ret < 0)
797 			break;
798 		read += ret;
799 		cond_resched();
800 	}
801 	if (ret == -ESHUTDOWN)
802 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
803 	else if (ret == -EACCES)
804 		xprt_wake_pending_tasks(&transport->xprt, -EACCES);
805 	else
806 		xs_poll_check_readable(transport);
807 out:
808 	mutex_unlock(&transport->recv_mutex);
809 	trace_xs_stream_read_data(&transport->xprt, ret, read);
810 }
811 
812 static void xs_stream_data_receive_workfn(struct work_struct *work)
813 {
814 	struct sock_xprt *transport =
815 		container_of(work, struct sock_xprt, recv_worker);
816 	unsigned int pflags = memalloc_nofs_save();
817 
818 	xs_stream_data_receive(transport);
819 	memalloc_nofs_restore(pflags);
820 }
821 
822 static void
823 xs_stream_reset_connect(struct sock_xprt *transport)
824 {
825 	transport->recv.offset = 0;
826 	transport->recv.len = 0;
827 	transport->recv.copied = 0;
828 	transport->xmit.offset = 0;
829 }
830 
831 static void
832 xs_stream_start_connect(struct sock_xprt *transport)
833 {
834 	transport->xprt.stat.connect_count++;
835 	transport->xprt.stat.connect_start = jiffies;
836 }
837 
838 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
839 
840 /**
841  * xs_nospace - handle transmit was incomplete
842  * @req: pointer to RPC request
843  * @transport: pointer to struct sock_xprt
844  *
845  */
846 static int xs_nospace(struct rpc_rqst *req, struct sock_xprt *transport)
847 {
848 	struct rpc_xprt *xprt = &transport->xprt;
849 	struct sock *sk = transport->inet;
850 	int ret = -EAGAIN;
851 
852 	trace_rpc_socket_nospace(req, transport);
853 
854 	/* Protect against races with write_space */
855 	spin_lock(&xprt->transport_lock);
856 
857 	/* Don't race with disconnect */
858 	if (xprt_connected(xprt)) {
859 		/* wait for more buffer space */
860 		set_bit(XPRT_SOCK_NOSPACE, &transport->sock_state);
861 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
862 		sk->sk_write_pending++;
863 		xprt_wait_for_buffer_space(xprt);
864 	} else
865 		ret = -ENOTCONN;
866 
867 	spin_unlock(&xprt->transport_lock);
868 	return ret;
869 }
870 
871 static int xs_sock_nospace(struct rpc_rqst *req)
872 {
873 	struct sock_xprt *transport =
874 		container_of(req->rq_xprt, struct sock_xprt, xprt);
875 	struct sock *sk = transport->inet;
876 	int ret = -EAGAIN;
877 
878 	lock_sock(sk);
879 	if (!sock_writeable(sk))
880 		ret = xs_nospace(req, transport);
881 	release_sock(sk);
882 	return ret;
883 }
884 
885 static int xs_stream_nospace(struct rpc_rqst *req, bool vm_wait)
886 {
887 	struct sock_xprt *transport =
888 		container_of(req->rq_xprt, struct sock_xprt, xprt);
889 	struct sock *sk = transport->inet;
890 	int ret = -EAGAIN;
891 
892 	if (vm_wait)
893 		return -ENOBUFS;
894 	lock_sock(sk);
895 	if (!sk_stream_memory_free(sk))
896 		ret = xs_nospace(req, transport);
897 	release_sock(sk);
898 	return ret;
899 }
900 
901 static int xs_stream_prepare_request(struct rpc_rqst *req, struct xdr_buf *buf)
902 {
903 	return xdr_alloc_bvec(buf, rpc_task_gfp_mask());
904 }
905 
906 static void xs_stream_abort_send_request(struct rpc_rqst *req)
907 {
908 	struct rpc_xprt *xprt = req->rq_xprt;
909 	struct sock_xprt *transport =
910 		container_of(xprt, struct sock_xprt, xprt);
911 
912 	if (transport->xmit.offset != 0 &&
913 	    !test_bit(XPRT_CLOSE_WAIT, &xprt->state))
914 		xprt_force_disconnect(xprt);
915 }
916 
917 /*
918  * Determine if the previous message in the stream was aborted before it
919  * could complete transmission.
920  */
921 static bool
922 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
923 {
924 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
925 }
926 
927 /*
928  * Return the stream record marker field for a record of length < 2^31-1
929  */
930 static rpc_fraghdr
931 xs_stream_record_marker(struct xdr_buf *xdr)
932 {
933 	if (!xdr->len)
934 		return 0;
935 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
936 }
937 
938 /**
939  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
940  * @req: pointer to RPC request
941  *
942  * Return values:
943  *        0:	The request has been sent
944  *   EAGAIN:	The socket was blocked, please call again later to
945  *		complete the request
946  * ENOTCONN:	Caller needs to invoke connect logic then call again
947  *    other:	Some other error occurred, the request was not sent
948  */
949 static int xs_local_send_request(struct rpc_rqst *req)
950 {
951 	struct rpc_xprt *xprt = req->rq_xprt;
952 	struct sock_xprt *transport =
953 				container_of(xprt, struct sock_xprt, xprt);
954 	struct xdr_buf *xdr = &req->rq_snd_buf;
955 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
956 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
957 	struct msghdr msg = {
958 		.msg_flags	= XS_SENDMSG_FLAGS,
959 	};
960 	bool vm_wait;
961 	unsigned int sent;
962 	int status;
963 
964 	/* Close the stream if the previous transmission was incomplete */
965 	if (xs_send_request_was_aborted(transport, req)) {
966 		xprt_force_disconnect(xprt);
967 		return -ENOTCONN;
968 	}
969 
970 	xs_pktdump("packet data:",
971 			req->rq_svec->iov_base, req->rq_svec->iov_len);
972 
973 	vm_wait = sk_stream_is_writeable(transport->inet) ? true : false;
974 
975 	req->rq_xtime = ktime_get();
976 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
977 				   transport->xmit.offset, rm, &sent);
978 	dprintk("RPC:       %s(%u) = %d\n",
979 			__func__, xdr->len - transport->xmit.offset, status);
980 
981 	if (likely(sent > 0) || status == 0) {
982 		transport->xmit.offset += sent;
983 		req->rq_bytes_sent = transport->xmit.offset;
984 		if (likely(req->rq_bytes_sent >= msglen)) {
985 			req->rq_xmit_bytes_sent += transport->xmit.offset;
986 			transport->xmit.offset = 0;
987 			return 0;
988 		}
989 		status = -EAGAIN;
990 		vm_wait = false;
991 	}
992 
993 	switch (status) {
994 	case -EAGAIN:
995 		status = xs_stream_nospace(req, vm_wait);
996 		break;
997 	default:
998 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
999 			-status);
1000 		fallthrough;
1001 	case -EPIPE:
1002 		xprt_force_disconnect(xprt);
1003 		status = -ENOTCONN;
1004 	}
1005 
1006 	return status;
1007 }
1008 
1009 /**
1010  * xs_udp_send_request - write an RPC request to a UDP 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 static int xs_udp_send_request(struct rpc_rqst *req)
1021 {
1022 	struct rpc_xprt *xprt = req->rq_xprt;
1023 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1024 	struct xdr_buf *xdr = &req->rq_snd_buf;
1025 	struct msghdr msg = {
1026 		.msg_name	= xs_addr(xprt),
1027 		.msg_namelen	= xprt->addrlen,
1028 		.msg_flags	= XS_SENDMSG_FLAGS,
1029 	};
1030 	unsigned int sent;
1031 	int status;
1032 
1033 	xs_pktdump("packet data:",
1034 				req->rq_svec->iov_base,
1035 				req->rq_svec->iov_len);
1036 
1037 	if (!xprt_bound(xprt))
1038 		return -ENOTCONN;
1039 
1040 	if (!xprt_request_get_cong(xprt, req))
1041 		return -EBADSLT;
1042 
1043 	status = xdr_alloc_bvec(xdr, rpc_task_gfp_mask());
1044 	if (status < 0)
1045 		return status;
1046 	req->rq_xtime = ktime_get();
1047 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
1048 
1049 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
1050 			xdr->len, status);
1051 
1052 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
1053 	if (status == -EPERM)
1054 		goto process_status;
1055 
1056 	if (status == -EAGAIN && sock_writeable(transport->inet))
1057 		status = -ENOBUFS;
1058 
1059 	if (sent > 0 || status == 0) {
1060 		req->rq_xmit_bytes_sent += sent;
1061 		if (sent >= req->rq_slen)
1062 			return 0;
1063 		/* Still some bytes left; set up for a retry later. */
1064 		status = -EAGAIN;
1065 	}
1066 
1067 process_status:
1068 	switch (status) {
1069 	case -ENOTSOCK:
1070 		status = -ENOTCONN;
1071 		/* Should we call xs_close() here? */
1072 		break;
1073 	case -EAGAIN:
1074 		status = xs_sock_nospace(req);
1075 		break;
1076 	case -ENETUNREACH:
1077 	case -ENOBUFS:
1078 	case -EPIPE:
1079 	case -ECONNREFUSED:
1080 	case -EPERM:
1081 		/* When the server has died, an ICMP port unreachable message
1082 		 * prompts ECONNREFUSED. */
1083 		break;
1084 	default:
1085 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1086 			-status);
1087 	}
1088 
1089 	return status;
1090 }
1091 
1092 /**
1093  * xs_tcp_send_request - write an RPC request to a TCP socket
1094  * @req: pointer to RPC request
1095  *
1096  * Return values:
1097  *        0:	The request has been sent
1098  *   EAGAIN:	The socket was blocked, please call again later to
1099  *		complete the request
1100  * ENOTCONN:	Caller needs to invoke connect logic then call again
1101  *    other:	Some other error occurred, the request was not sent
1102  *
1103  * XXX: In the case of soft timeouts, should we eventually give up
1104  *	if sendmsg is not able to make progress?
1105  */
1106 static int xs_tcp_send_request(struct rpc_rqst *req)
1107 {
1108 	struct rpc_xprt *xprt = req->rq_xprt;
1109 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1110 	struct xdr_buf *xdr = &req->rq_snd_buf;
1111 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
1112 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1113 	struct msghdr msg = {
1114 		.msg_flags	= XS_SENDMSG_FLAGS,
1115 	};
1116 	bool vm_wait;
1117 	unsigned int sent;
1118 	int status;
1119 
1120 	/* Close the stream if the previous transmission was incomplete */
1121 	if (xs_send_request_was_aborted(transport, req)) {
1122 		if (transport->sock != NULL)
1123 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1124 		return -ENOTCONN;
1125 	}
1126 	if (!transport->inet)
1127 		return -ENOTCONN;
1128 
1129 	xs_pktdump("packet data:",
1130 				req->rq_svec->iov_base,
1131 				req->rq_svec->iov_len);
1132 
1133 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1134 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1135 
1136 	xs_set_srcport(transport, transport->sock);
1137 
1138 	/* Continue transmitting the packet/record. We must be careful
1139 	 * to cope with writespace callbacks arriving _after_ we have
1140 	 * called sendmsg(). */
1141 	req->rq_xtime = ktime_get();
1142 	tcp_sock_set_cork(transport->inet, true);
1143 
1144 	vm_wait = sk_stream_is_writeable(transport->inet) ? true : false;
1145 
1146 	do {
1147 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1148 					   transport->xmit.offset, rm, &sent);
1149 
1150 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1151 				xdr->len - transport->xmit.offset, status);
1152 
1153 		/* If we've sent the entire packet, immediately
1154 		 * reset the count of bytes sent. */
1155 		transport->xmit.offset += sent;
1156 		req->rq_bytes_sent = transport->xmit.offset;
1157 		if (likely(req->rq_bytes_sent >= msglen)) {
1158 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1159 			transport->xmit.offset = 0;
1160 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1161 				tcp_sock_set_cork(transport->inet, false);
1162 			return 0;
1163 		}
1164 
1165 		WARN_ON_ONCE(sent == 0 && status == 0);
1166 
1167 		if (sent > 0)
1168 			vm_wait = false;
1169 
1170 	} while (status == 0);
1171 
1172 	switch (status) {
1173 	case -ENOTSOCK:
1174 		status = -ENOTCONN;
1175 		/* Should we call xs_close() here? */
1176 		break;
1177 	case -EAGAIN:
1178 		status = xs_stream_nospace(req, vm_wait);
1179 		break;
1180 	case -ECONNRESET:
1181 	case -ECONNREFUSED:
1182 	case -ENOTCONN:
1183 	case -EADDRINUSE:
1184 	case -ENOBUFS:
1185 	case -EPIPE:
1186 		break;
1187 	default:
1188 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1189 			-status);
1190 	}
1191 
1192 	return status;
1193 }
1194 
1195 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1196 {
1197 	transport->old_data_ready = sk->sk_data_ready;
1198 	transport->old_state_change = sk->sk_state_change;
1199 	transport->old_write_space = sk->sk_write_space;
1200 	transport->old_error_report = sk->sk_error_report;
1201 }
1202 
1203 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1204 {
1205 	sk->sk_data_ready = transport->old_data_ready;
1206 	sk->sk_state_change = transport->old_state_change;
1207 	sk->sk_write_space = transport->old_write_space;
1208 	sk->sk_error_report = transport->old_error_report;
1209 }
1210 
1211 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1212 {
1213 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1214 
1215 	transport->xprt_err = 0;
1216 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1217 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1218 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1219 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1220 	clear_bit(XPRT_SOCK_NOSPACE, &transport->sock_state);
1221 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
1222 }
1223 
1224 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1225 {
1226 	set_bit(nr, &transport->sock_state);
1227 	queue_work(xprtiod_workqueue, &transport->error_worker);
1228 }
1229 
1230 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1231 {
1232 	xprt->connect_cookie++;
1233 	smp_mb__before_atomic();
1234 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1235 	clear_bit(XPRT_CLOSING, &xprt->state);
1236 	xs_sock_reset_state_flags(xprt);
1237 	smp_mb__after_atomic();
1238 }
1239 
1240 /**
1241  * xs_error_report - callback to handle TCP socket state errors
1242  * @sk: socket
1243  *
1244  * Note: we don't call sock_error() since there may be a rpc_task
1245  * using the socket, and so we don't want to clear sk->sk_err.
1246  */
1247 static void xs_error_report(struct sock *sk)
1248 {
1249 	struct sock_xprt *transport;
1250 	struct rpc_xprt *xprt;
1251 
1252 	if (!(xprt = xprt_from_sock(sk)))
1253 		return;
1254 
1255 	transport = container_of(xprt, struct sock_xprt, xprt);
1256 	transport->xprt_err = -sk->sk_err;
1257 	if (transport->xprt_err == 0)
1258 		return;
1259 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1260 			xprt, -transport->xprt_err);
1261 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1262 
1263 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1264 	smp_mb__before_atomic();
1265 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1266 }
1267 
1268 static void xs_reset_transport(struct sock_xprt *transport)
1269 {
1270 	struct socket *sock = transport->sock;
1271 	struct sock *sk = transport->inet;
1272 	struct rpc_xprt *xprt = &transport->xprt;
1273 	struct file *filp = transport->file;
1274 
1275 	if (sk == NULL)
1276 		return;
1277 	/*
1278 	 * Make sure we're calling this in a context from which it is safe
1279 	 * to call __fput_sync(). In practice that means rpciod and the
1280 	 * system workqueue.
1281 	 */
1282 	if (!(current->flags & PF_WQ_WORKER)) {
1283 		WARN_ON_ONCE(1);
1284 		set_bit(XPRT_CLOSE_WAIT, &xprt->state);
1285 		return;
1286 	}
1287 
1288 	if (atomic_read(&transport->xprt.swapper))
1289 		sk_clear_memalloc(sk);
1290 
1291 	tls_handshake_cancel(sk);
1292 
1293 	kernel_sock_shutdown(sock, SHUT_RDWR);
1294 
1295 	mutex_lock(&transport->recv_mutex);
1296 	lock_sock(sk);
1297 	transport->inet = NULL;
1298 	transport->sock = NULL;
1299 	transport->file = NULL;
1300 
1301 	sk->sk_user_data = NULL;
1302 	sk->sk_sndtimeo = 0;
1303 
1304 	xs_restore_old_callbacks(transport, sk);
1305 	xprt_clear_connected(xprt);
1306 	xs_sock_reset_connection_flags(xprt);
1307 	/* Reset stream record info */
1308 	xs_stream_reset_connect(transport);
1309 	release_sock(sk);
1310 	mutex_unlock(&transport->recv_mutex);
1311 
1312 	trace_rpc_socket_close(xprt, sock);
1313 	__fput_sync(filp);
1314 
1315 	xprt_disconnect_done(xprt);
1316 }
1317 
1318 /**
1319  * xs_close - close a socket
1320  * @xprt: transport
1321  *
1322  * This is used when all requests are complete; ie, no DRC state remains
1323  * on the server we want to save.
1324  *
1325  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1326  * xs_reset_transport() zeroing the socket from underneath a writer.
1327  */
1328 static void xs_close(struct rpc_xprt *xprt)
1329 {
1330 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1331 
1332 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1333 
1334 	if (transport->sock)
1335 		tls_handshake_close(transport->sock);
1336 	xs_reset_transport(transport);
1337 	xprt->reestablish_timeout = 0;
1338 }
1339 
1340 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1341 {
1342 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1343 		xprt);
1344 	xprt_disconnect_done(xprt);
1345 }
1346 
1347 static void xs_xprt_free(struct rpc_xprt *xprt)
1348 {
1349 	xs_free_peer_addresses(xprt);
1350 	xprt_free(xprt);
1351 }
1352 
1353 /**
1354  * xs_destroy - prepare to shutdown a transport
1355  * @xprt: doomed transport
1356  *
1357  */
1358 static void xs_destroy(struct rpc_xprt *xprt)
1359 {
1360 	struct sock_xprt *transport = container_of(xprt,
1361 			struct sock_xprt, xprt);
1362 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1363 
1364 	cancel_delayed_work_sync(&transport->connect_worker);
1365 	xs_close(xprt);
1366 	cancel_work_sync(&transport->recv_worker);
1367 	cancel_work_sync(&transport->error_worker);
1368 	xs_xprt_free(xprt);
1369 	module_put(THIS_MODULE);
1370 }
1371 
1372 /**
1373  * xs_udp_data_read_skb - receive callback for UDP sockets
1374  * @xprt: transport
1375  * @sk: socket
1376  * @skb: skbuff
1377  *
1378  */
1379 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1380 		struct sock *sk,
1381 		struct sk_buff *skb)
1382 {
1383 	struct rpc_task *task;
1384 	struct rpc_rqst *rovr;
1385 	int repsize, copied;
1386 	u32 _xid;
1387 	__be32 *xp;
1388 
1389 	repsize = skb->len;
1390 	if (repsize < 4) {
1391 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1392 		return;
1393 	}
1394 
1395 	/* Copy the XID from the skb... */
1396 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1397 	if (xp == NULL)
1398 		return;
1399 
1400 	/* Look up and lock the request corresponding to the given XID */
1401 	spin_lock(&xprt->queue_lock);
1402 	rovr = xprt_lookup_rqst(xprt, *xp);
1403 	if (!rovr)
1404 		goto out_unlock;
1405 	xprt_pin_rqst(rovr);
1406 	xprt_update_rtt(rovr->rq_task);
1407 	spin_unlock(&xprt->queue_lock);
1408 	task = rovr->rq_task;
1409 
1410 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1411 		copied = repsize;
1412 
1413 	/* Suck it into the iovec, verify checksum if not done by hw. */
1414 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1415 		spin_lock(&xprt->queue_lock);
1416 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1417 		goto out_unpin;
1418 	}
1419 
1420 
1421 	spin_lock(&xprt->transport_lock);
1422 	xprt_adjust_cwnd(xprt, task, copied);
1423 	spin_unlock(&xprt->transport_lock);
1424 	spin_lock(&xprt->queue_lock);
1425 	xprt_complete_rqst(task, copied);
1426 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1427 out_unpin:
1428 	xprt_unpin_rqst(rovr);
1429  out_unlock:
1430 	spin_unlock(&xprt->queue_lock);
1431 }
1432 
1433 static void xs_udp_data_receive(struct sock_xprt *transport)
1434 {
1435 	struct sk_buff *skb;
1436 	struct sock *sk;
1437 	int err;
1438 
1439 	mutex_lock(&transport->recv_mutex);
1440 	sk = transport->inet;
1441 	if (sk == NULL)
1442 		goto out;
1443 	for (;;) {
1444 		skb = skb_recv_udp(sk, MSG_DONTWAIT, &err);
1445 		if (skb == NULL)
1446 			break;
1447 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1448 		consume_skb(skb);
1449 		cond_resched();
1450 	}
1451 	xs_poll_check_readable(transport);
1452 out:
1453 	mutex_unlock(&transport->recv_mutex);
1454 }
1455 
1456 static void xs_udp_data_receive_workfn(struct work_struct *work)
1457 {
1458 	struct sock_xprt *transport =
1459 		container_of(work, struct sock_xprt, recv_worker);
1460 	unsigned int pflags = memalloc_nofs_save();
1461 
1462 	xs_udp_data_receive(transport);
1463 	memalloc_nofs_restore(pflags);
1464 }
1465 
1466 /**
1467  * xs_data_ready - "data ready" callback for sockets
1468  * @sk: socket with data to read
1469  *
1470  */
1471 static void xs_data_ready(struct sock *sk)
1472 {
1473 	struct rpc_xprt *xprt;
1474 
1475 	trace_sk_data_ready(sk);
1476 
1477 	xprt = xprt_from_sock(sk);
1478 	if (xprt != NULL) {
1479 		struct sock_xprt *transport = container_of(xprt,
1480 				struct sock_xprt, xprt);
1481 
1482 		trace_xs_data_ready(xprt);
1483 
1484 		transport->old_data_ready(sk);
1485 
1486 		if (test_bit(XPRT_SOCK_IGNORE_RECV, &transport->sock_state))
1487 			return;
1488 
1489 		/* Any data means we had a useful conversation, so
1490 		 * then we don't need to delay the next reconnect
1491 		 */
1492 		if (xprt->reestablish_timeout)
1493 			xprt->reestablish_timeout = 0;
1494 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1495 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1496 	}
1497 }
1498 
1499 /*
1500  * Helper function to force a TCP close if the server is sending
1501  * junk and/or it has put us in CLOSE_WAIT
1502  */
1503 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1504 {
1505 	xprt_force_disconnect(xprt);
1506 }
1507 
1508 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1509 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1510 {
1511 	return PAGE_SIZE;
1512 }
1513 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1514 
1515 /**
1516  * xs_local_state_change - callback to handle AF_LOCAL socket state changes
1517  * @sk: socket whose state has changed
1518  *
1519  */
1520 static void xs_local_state_change(struct sock *sk)
1521 {
1522 	struct rpc_xprt *xprt;
1523 	struct sock_xprt *transport;
1524 
1525 	if (!(xprt = xprt_from_sock(sk)))
1526 		return;
1527 	transport = container_of(xprt, struct sock_xprt, xprt);
1528 	if (sk->sk_shutdown & SHUTDOWN_MASK) {
1529 		clear_bit(XPRT_CONNECTED, &xprt->state);
1530 		/* Trigger the socket release */
1531 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1532 	}
1533 }
1534 
1535 /**
1536  * xs_tcp_state_change - callback to handle TCP socket state changes
1537  * @sk: socket whose state has changed
1538  *
1539  */
1540 static void xs_tcp_state_change(struct sock *sk)
1541 {
1542 	struct rpc_xprt *xprt;
1543 	struct sock_xprt *transport;
1544 
1545 	if (!(xprt = xprt_from_sock(sk)))
1546 		return;
1547 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1548 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1549 			sk->sk_state, xprt_connected(xprt),
1550 			sock_flag(sk, SOCK_DEAD),
1551 			sock_flag(sk, SOCK_ZAPPED),
1552 			sk->sk_shutdown);
1553 
1554 	transport = container_of(xprt, struct sock_xprt, xprt);
1555 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1556 	switch (sk->sk_state) {
1557 	case TCP_ESTABLISHED:
1558 		if (!xprt_test_and_set_connected(xprt)) {
1559 			xprt->connect_cookie++;
1560 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1561 			xprt_clear_connecting(xprt);
1562 
1563 			xprt->stat.connect_count++;
1564 			xprt->stat.connect_time += (long)jiffies -
1565 						   xprt->stat.connect_start;
1566 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1567 		}
1568 		break;
1569 	case TCP_FIN_WAIT1:
1570 		/* The client initiated a shutdown of the socket */
1571 		xprt->connect_cookie++;
1572 		xprt->reestablish_timeout = 0;
1573 		set_bit(XPRT_CLOSING, &xprt->state);
1574 		smp_mb__before_atomic();
1575 		clear_bit(XPRT_CONNECTED, &xprt->state);
1576 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1577 		smp_mb__after_atomic();
1578 		break;
1579 	case TCP_CLOSE_WAIT:
1580 		/* The server initiated a shutdown of the socket */
1581 		xprt->connect_cookie++;
1582 		clear_bit(XPRT_CONNECTED, &xprt->state);
1583 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1584 		fallthrough;
1585 	case TCP_CLOSING:
1586 		/*
1587 		 * If the server closed down the connection, make sure that
1588 		 * we back off before reconnecting
1589 		 */
1590 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1591 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1592 		break;
1593 	case TCP_LAST_ACK:
1594 		set_bit(XPRT_CLOSING, &xprt->state);
1595 		smp_mb__before_atomic();
1596 		clear_bit(XPRT_CONNECTED, &xprt->state);
1597 		smp_mb__after_atomic();
1598 		break;
1599 	case TCP_CLOSE:
1600 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1601 				       &transport->sock_state)) {
1602 			xs_reset_srcport(transport);
1603 			xprt_clear_connecting(xprt);
1604 		}
1605 		clear_bit(XPRT_CLOSING, &xprt->state);
1606 		/* Trigger the socket release */
1607 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1608 	}
1609 }
1610 
1611 static void xs_write_space(struct sock *sk)
1612 {
1613 	struct sock_xprt *transport;
1614 	struct rpc_xprt *xprt;
1615 
1616 	if (!sk->sk_socket)
1617 		return;
1618 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1619 
1620 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1621 		return;
1622 	transport = container_of(xprt, struct sock_xprt, xprt);
1623 	if (!test_and_clear_bit(XPRT_SOCK_NOSPACE, &transport->sock_state))
1624 		return;
1625 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1626 	sk->sk_write_pending--;
1627 }
1628 
1629 /**
1630  * xs_udp_write_space - callback invoked when socket buffer space
1631  *                             becomes available
1632  * @sk: socket whose state has changed
1633  *
1634  * Called when more output buffer space is available for this socket.
1635  * We try not to wake our writers until they can make "significant"
1636  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1637  * with a bunch of small requests.
1638  */
1639 static void xs_udp_write_space(struct sock *sk)
1640 {
1641 	/* from net/core/sock.c:sock_def_write_space */
1642 	if (sock_writeable(sk))
1643 		xs_write_space(sk);
1644 }
1645 
1646 /**
1647  * xs_tcp_write_space - callback invoked when socket buffer space
1648  *                             becomes available
1649  * @sk: socket whose state has changed
1650  *
1651  * Called when more output buffer space is available for this socket.
1652  * We try not to wake our writers until they can make "significant"
1653  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1654  * with a bunch of small requests.
1655  */
1656 static void xs_tcp_write_space(struct sock *sk)
1657 {
1658 	/* from net/core/stream.c:sk_stream_write_space */
1659 	if (sk_stream_is_writeable(sk))
1660 		xs_write_space(sk);
1661 }
1662 
1663 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1664 {
1665 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1666 	struct sock *sk = transport->inet;
1667 
1668 	if (transport->rcvsize) {
1669 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1670 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1671 	}
1672 	if (transport->sndsize) {
1673 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1674 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1675 		sk->sk_write_space(sk);
1676 	}
1677 }
1678 
1679 /**
1680  * xs_udp_set_buffer_size - set send and receive limits
1681  * @xprt: generic transport
1682  * @sndsize: requested size of send buffer, in bytes
1683  * @rcvsize: requested size of receive buffer, in bytes
1684  *
1685  * Set socket send and receive buffer size limits.
1686  */
1687 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1688 {
1689 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1690 
1691 	transport->sndsize = 0;
1692 	if (sndsize)
1693 		transport->sndsize = sndsize + 1024;
1694 	transport->rcvsize = 0;
1695 	if (rcvsize)
1696 		transport->rcvsize = rcvsize + 1024;
1697 
1698 	xs_udp_do_set_buffer_size(xprt);
1699 }
1700 
1701 /**
1702  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1703  * @xprt: controlling transport
1704  * @task: task that timed out
1705  *
1706  * Adjust the congestion window after a retransmit timeout has occurred.
1707  */
1708 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1709 {
1710 	spin_lock(&xprt->transport_lock);
1711 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1712 	spin_unlock(&xprt->transport_lock);
1713 }
1714 
1715 static int xs_get_random_port(void)
1716 {
1717 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1718 	unsigned short range;
1719 	unsigned short rand;
1720 
1721 	if (max < min)
1722 		return -EADDRINUSE;
1723 	range = max - min + 1;
1724 	rand = get_random_u32_below(range);
1725 	return rand + min;
1726 }
1727 
1728 static unsigned short xs_sock_getport(struct socket *sock)
1729 {
1730 	struct sockaddr_storage buf;
1731 	unsigned short port = 0;
1732 
1733 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1734 		goto out;
1735 	switch (buf.ss_family) {
1736 	case AF_INET6:
1737 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1738 		break;
1739 	case AF_INET:
1740 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1741 	}
1742 out:
1743 	return port;
1744 }
1745 
1746 /**
1747  * xs_set_port - reset the port number in the remote endpoint address
1748  * @xprt: generic transport
1749  * @port: new port number
1750  *
1751  */
1752 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1753 {
1754 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1755 
1756 	rpc_set_port(xs_addr(xprt), port);
1757 	xs_update_peer_port(xprt);
1758 }
1759 
1760 static void xs_reset_srcport(struct sock_xprt *transport)
1761 {
1762 	transport->srcport = 0;
1763 }
1764 
1765 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1766 {
1767 	if (transport->srcport == 0 && transport->xprt.reuseport)
1768 		transport->srcport = xs_sock_getport(sock);
1769 }
1770 
1771 static int xs_get_srcport(struct sock_xprt *transport)
1772 {
1773 	int port = transport->srcport;
1774 
1775 	if (port == 0 && transport->xprt.resvport)
1776 		port = xs_get_random_port();
1777 	return port;
1778 }
1779 
1780 static unsigned short xs_sock_srcport(struct rpc_xprt *xprt)
1781 {
1782 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1783 	unsigned short ret = 0;
1784 	mutex_lock(&sock->recv_mutex);
1785 	if (sock->sock)
1786 		ret = xs_sock_getport(sock->sock);
1787 	mutex_unlock(&sock->recv_mutex);
1788 	return ret;
1789 }
1790 
1791 static int xs_sock_srcaddr(struct rpc_xprt *xprt, char *buf, size_t buflen)
1792 {
1793 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1794 	union {
1795 		struct sockaddr sa;
1796 		struct sockaddr_storage st;
1797 	} saddr;
1798 	int ret = -ENOTCONN;
1799 
1800 	mutex_lock(&sock->recv_mutex);
1801 	if (sock->sock) {
1802 		ret = kernel_getsockname(sock->sock, &saddr.sa);
1803 		if (ret >= 0)
1804 			ret = snprintf(buf, buflen, "%pISc", &saddr.sa);
1805 	}
1806 	mutex_unlock(&sock->recv_mutex);
1807 	return ret;
1808 }
1809 
1810 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1811 {
1812 	if (transport->srcport != 0)
1813 		transport->srcport = 0;
1814 	if (!transport->xprt.resvport)
1815 		return 0;
1816 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1817 		return xprt_max_resvport;
1818 	return --port;
1819 }
1820 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1821 {
1822 	struct sockaddr_storage myaddr;
1823 	int err, nloop = 0;
1824 	int port = xs_get_srcport(transport);
1825 	unsigned short last;
1826 
1827 	/*
1828 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1829 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1830 	 * port selection happen implicitly when the socket is used
1831 	 * (for example at connect time).
1832 	 *
1833 	 * This ensures that we can continue to establish TCP
1834 	 * connections even when all local ephemeral ports are already
1835 	 * a part of some TCP connection.  This makes no difference
1836 	 * for UDP sockets, but also doesn't harm them.
1837 	 *
1838 	 * If we're asking for any reserved port (i.e. port == 0 &&
1839 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1840 	 * ensure that port is non-zero and we will bind as needed.
1841 	 */
1842 	if (port <= 0)
1843 		return port;
1844 
1845 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1846 	do {
1847 		rpc_set_port((struct sockaddr *)&myaddr, port);
1848 		err = kernel_bind(sock, (struct sockaddr_unsized *)&myaddr,
1849 				  transport->xprt.addrlen);
1850 		if (err == 0) {
1851 			if (transport->xprt.reuseport)
1852 				transport->srcport = port;
1853 			break;
1854 		}
1855 		last = port;
1856 		port = xs_next_srcport(transport, port);
1857 		if (port > last)
1858 			nloop++;
1859 	} while (err == -EADDRINUSE && nloop != 2);
1860 
1861 	if (myaddr.ss_family == AF_INET)
1862 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1863 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1864 				port, err ? "failed" : "ok", err);
1865 	else
1866 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1867 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1868 				port, err ? "failed" : "ok", err);
1869 	return err;
1870 }
1871 
1872 /*
1873  * We don't support autobind on AF_LOCAL sockets
1874  */
1875 static void xs_local_rpcbind(struct rpc_task *task)
1876 {
1877 	xprt_set_bound(task->tk_xprt);
1878 }
1879 
1880 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1881 {
1882 }
1883 
1884 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1885 static struct lock_class_key xs_key[3];
1886 static struct lock_class_key xs_slock_key[3];
1887 
1888 static inline void xs_reclassify_socketu(struct socket *sock)
1889 {
1890 	struct sock *sk = sock->sk;
1891 
1892 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1893 		&xs_slock_key[0], "sk_lock-AF_LOCAL-RPC", &xs_key[0]);
1894 }
1895 
1896 static inline void xs_reclassify_socket4(struct socket *sock)
1897 {
1898 	struct sock *sk = sock->sk;
1899 
1900 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1901 		&xs_slock_key[1], "sk_lock-AF_INET-RPC", &xs_key[1]);
1902 }
1903 
1904 static inline void xs_reclassify_socket6(struct socket *sock)
1905 {
1906 	struct sock *sk = sock->sk;
1907 
1908 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1909 		&xs_slock_key[2], "sk_lock-AF_INET6-RPC", &xs_key[2]);
1910 }
1911 
1912 static inline void xs_reclassify_socket(int family, struct socket *sock)
1913 {
1914 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1915 		return;
1916 
1917 	switch (family) {
1918 	case AF_LOCAL:
1919 		xs_reclassify_socketu(sock);
1920 		break;
1921 	case AF_INET:
1922 		xs_reclassify_socket4(sock);
1923 		break;
1924 	case AF_INET6:
1925 		xs_reclassify_socket6(sock);
1926 		break;
1927 	}
1928 }
1929 #else
1930 static inline void xs_reclassify_socket(int family, struct socket *sock)
1931 {
1932 }
1933 #endif
1934 
1935 static void xs_dummy_setup_socket(struct work_struct *work)
1936 {
1937 }
1938 
1939 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1940 		struct sock_xprt *transport, int family, int type,
1941 		int protocol, bool reuseport)
1942 {
1943 	struct file *filp;
1944 	struct socket *sock;
1945 	int err;
1946 
1947 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1948 	if (err < 0) {
1949 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1950 				protocol, -err);
1951 		goto out;
1952 	}
1953 	xs_reclassify_socket(family, sock);
1954 
1955 	if (reuseport)
1956 		sock_set_reuseport(sock->sk);
1957 
1958 	err = xs_bind(transport, sock);
1959 	if (err) {
1960 		sock_release(sock);
1961 		goto out;
1962 	}
1963 
1964 	if (protocol == IPPROTO_TCP)
1965 		sk_net_refcnt_upgrade(sock->sk);
1966 
1967 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1968 	if (IS_ERR(filp))
1969 		return ERR_CAST(filp);
1970 	transport->file = filp;
1971 
1972 	return sock;
1973 out:
1974 	return ERR_PTR(err);
1975 }
1976 
1977 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1978 				      struct socket *sock)
1979 {
1980 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1981 									xprt);
1982 
1983 	if (!transport->inet) {
1984 		struct sock *sk = sock->sk;
1985 
1986 		lock_sock(sk);
1987 
1988 		xs_save_old_callbacks(transport, sk);
1989 
1990 		sk->sk_user_data = xprt;
1991 		sk->sk_data_ready = xs_data_ready;
1992 		sk->sk_write_space = xs_udp_write_space;
1993 		sk->sk_state_change = xs_local_state_change;
1994 		sk->sk_error_report = xs_error_report;
1995 		sk->sk_use_task_frag = false;
1996 
1997 		xprt_clear_connected(xprt);
1998 
1999 		/* Reset to new socket */
2000 		transport->sock = sock;
2001 		transport->inet = sk;
2002 
2003 		release_sock(sk);
2004 	}
2005 
2006 	xs_stream_start_connect(transport);
2007 
2008 	return kernel_connect(sock, (struct sockaddr_unsized *)xs_addr(xprt), xprt->addrlen, 0);
2009 }
2010 
2011 /**
2012  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
2013  * @transport: socket transport to connect
2014  */
2015 static int xs_local_setup_socket(struct sock_xprt *transport)
2016 {
2017 	struct rpc_xprt *xprt = &transport->xprt;
2018 	struct file *filp;
2019 	struct socket *sock;
2020 	int status;
2021 
2022 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
2023 					SOCK_STREAM, 0, &sock, 1);
2024 	if (status < 0) {
2025 		dprintk("RPC:       can't create AF_LOCAL "
2026 			"transport socket (%d).\n", -status);
2027 		goto out;
2028 	}
2029 	xs_reclassify_socket(AF_LOCAL, sock);
2030 
2031 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
2032 	if (IS_ERR(filp)) {
2033 		status = PTR_ERR(filp);
2034 		goto out;
2035 	}
2036 	transport->file = filp;
2037 
2038 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
2039 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2040 
2041 	status = xs_local_finish_connecting(xprt, sock);
2042 	trace_rpc_socket_connect(xprt, sock, status);
2043 	switch (status) {
2044 	case 0:
2045 		dprintk("RPC:       xprt %p connected to %s\n",
2046 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2047 		xprt->stat.connect_count++;
2048 		xprt->stat.connect_time += (long)jiffies -
2049 					   xprt->stat.connect_start;
2050 		xprt_set_connected(xprt);
2051 		break;
2052 	case -ENOBUFS:
2053 		break;
2054 	case -ENOENT:
2055 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
2056 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2057 		break;
2058 	case -ECONNREFUSED:
2059 		dprintk("RPC:       xprt %p: connection refused for %s\n",
2060 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2061 		break;
2062 	default:
2063 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2064 				__func__, -status,
2065 				xprt->address_strings[RPC_DISPLAY_ADDR]);
2066 	}
2067 
2068 out:
2069 	xprt_clear_connecting(xprt);
2070 	xprt_wake_pending_tasks(xprt, status);
2071 	return status;
2072 }
2073 
2074 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2075 {
2076 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2077 	int ret;
2078 
2079 	if (transport->file)
2080 		goto force_disconnect;
2081 
2082 	if (RPC_IS_ASYNC(task)) {
2083 		/*
2084 		 * We want the AF_LOCAL connect to be resolved in the
2085 		 * filesystem namespace of the process making the rpc
2086 		 * call.  Thus we connect synchronously.
2087 		 *
2088 		 * If we want to support asynchronous AF_LOCAL calls,
2089 		 * we'll need to figure out how to pass a namespace to
2090 		 * connect.
2091 		 */
2092 		rpc_task_set_rpc_status(task, -ENOTCONN);
2093 		goto out_wake;
2094 	}
2095 	ret = xs_local_setup_socket(transport);
2096 	if (ret && !RPC_IS_SOFTCONN(task))
2097 		msleep_interruptible(15000);
2098 	return;
2099 force_disconnect:
2100 	xprt_force_disconnect(xprt);
2101 out_wake:
2102 	xprt_clear_connecting(xprt);
2103 	xprt_wake_pending_tasks(xprt, -ENOTCONN);
2104 }
2105 
2106 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2107 /*
2108  * Note that this should be called with XPRT_LOCKED held, or recv_mutex
2109  * held, or when we otherwise know that we have exclusive access to the
2110  * socket, to guard against races with xs_reset_transport.
2111  */
2112 static void xs_set_memalloc(struct rpc_xprt *xprt)
2113 {
2114 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2115 			xprt);
2116 
2117 	/*
2118 	 * If there's no sock, then we have nothing to set. The
2119 	 * reconnecting process will get it for us.
2120 	 */
2121 	if (!transport->inet)
2122 		return;
2123 	if (atomic_read(&xprt->swapper))
2124 		sk_set_memalloc(transport->inet);
2125 }
2126 
2127 /**
2128  * xs_enable_swap - Tag this transport as being used for swap.
2129  * @xprt: transport to tag
2130  *
2131  * Take a reference to this transport on behalf of the rpc_clnt, and
2132  * optionally mark it for swapping if it wasn't already.
2133  */
2134 static int
2135 xs_enable_swap(struct rpc_xprt *xprt)
2136 {
2137 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2138 
2139 	mutex_lock(&xs->recv_mutex);
2140 	if (atomic_inc_return(&xprt->swapper) == 1 &&
2141 	    xs->inet)
2142 		sk_set_memalloc(xs->inet);
2143 	mutex_unlock(&xs->recv_mutex);
2144 	return 0;
2145 }
2146 
2147 /**
2148  * xs_disable_swap - Untag this transport as being used for swap.
2149  * @xprt: transport to tag
2150  *
2151  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2152  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2153  */
2154 static void
2155 xs_disable_swap(struct rpc_xprt *xprt)
2156 {
2157 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2158 
2159 	mutex_lock(&xs->recv_mutex);
2160 	if (atomic_dec_and_test(&xprt->swapper) &&
2161 	    xs->inet)
2162 		sk_clear_memalloc(xs->inet);
2163 	mutex_unlock(&xs->recv_mutex);
2164 }
2165 #else
2166 static void xs_set_memalloc(struct rpc_xprt *xprt)
2167 {
2168 }
2169 
2170 static int
2171 xs_enable_swap(struct rpc_xprt *xprt)
2172 {
2173 	return -EINVAL;
2174 }
2175 
2176 static void
2177 xs_disable_swap(struct rpc_xprt *xprt)
2178 {
2179 }
2180 #endif
2181 
2182 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2183 {
2184 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2185 
2186 	if (!transport->inet) {
2187 		struct sock *sk = sock->sk;
2188 
2189 		lock_sock(sk);
2190 
2191 		xs_save_old_callbacks(transport, sk);
2192 
2193 		sk->sk_user_data = xprt;
2194 		sk->sk_data_ready = xs_data_ready;
2195 		sk->sk_write_space = xs_udp_write_space;
2196 		sk->sk_use_task_frag = false;
2197 
2198 		xprt_set_connected(xprt);
2199 
2200 		/* Reset to new socket */
2201 		transport->sock = sock;
2202 		transport->inet = sk;
2203 
2204 		xs_set_memalloc(xprt);
2205 
2206 		release_sock(sk);
2207 	}
2208 	xs_udp_do_set_buffer_size(xprt);
2209 
2210 	xprt->stat.connect_start = jiffies;
2211 }
2212 
2213 static void xs_udp_setup_socket(struct work_struct *work)
2214 {
2215 	struct sock_xprt *transport =
2216 		container_of(work, struct sock_xprt, connect_worker.work);
2217 	struct rpc_xprt *xprt = &transport->xprt;
2218 	struct socket *sock;
2219 	int status = -EIO;
2220 	unsigned int pflags = current->flags;
2221 
2222 	if (atomic_read(&xprt->swapper))
2223 		current->flags |= PF_MEMALLOC;
2224 	sock = xs_create_sock(xprt, transport,
2225 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2226 			IPPROTO_UDP, false);
2227 	if (IS_ERR(sock))
2228 		goto out;
2229 
2230 	dprintk("RPC:       worker connecting xprt %p via %s to "
2231 				"%s (port %s)\n", xprt,
2232 			xprt->address_strings[RPC_DISPLAY_PROTO],
2233 			xprt->address_strings[RPC_DISPLAY_ADDR],
2234 			xprt->address_strings[RPC_DISPLAY_PORT]);
2235 
2236 	xs_udp_finish_connecting(xprt, sock);
2237 	trace_rpc_socket_connect(xprt, sock, 0);
2238 	status = 0;
2239 out:
2240 	xprt_clear_connecting(xprt);
2241 	xprt_unlock_connect(xprt, transport);
2242 	xprt_wake_pending_tasks(xprt, status);
2243 	current_restore_flags(pflags, PF_MEMALLOC);
2244 }
2245 
2246 /**
2247  * xs_tcp_shutdown - gracefully shut down a TCP socket
2248  * @xprt: transport
2249  *
2250  * Initiates a graceful shutdown of the TCP socket by calling the
2251  * equivalent of shutdown(SHUT_RDWR);
2252  */
2253 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2254 {
2255 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2256 	struct socket *sock = transport->sock;
2257 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2258 
2259 	if (sock == NULL)
2260 		return;
2261 	if (!xprt->reuseport) {
2262 		xs_close(xprt);
2263 		return;
2264 	}
2265 	switch (skst) {
2266 	case TCP_FIN_WAIT1:
2267 	case TCP_FIN_WAIT2:
2268 	case TCP_LAST_ACK:
2269 		break;
2270 	case TCP_ESTABLISHED:
2271 	case TCP_CLOSE_WAIT:
2272 		kernel_sock_shutdown(sock, SHUT_RDWR);
2273 		trace_rpc_socket_shutdown(xprt, sock);
2274 		break;
2275 	default:
2276 		xs_reset_transport(transport);
2277 	}
2278 }
2279 
2280 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2281 		struct socket *sock)
2282 {
2283 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2284 	struct net *net = sock_net(sock->sk);
2285 	unsigned long connect_timeout;
2286 	unsigned long syn_retries;
2287 	unsigned int keepidle;
2288 	unsigned int keepcnt;
2289 	unsigned int timeo;
2290 	unsigned long t;
2291 
2292 	spin_lock(&xprt->transport_lock);
2293 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2294 	keepcnt = xprt->timeout->to_retries + 1;
2295 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2296 		(xprt->timeout->to_retries + 1);
2297 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2298 	spin_unlock(&xprt->transport_lock);
2299 
2300 	/* TCP Keepalive options */
2301 	sock_set_keepalive(sock->sk);
2302 	tcp_sock_set_keepidle(sock->sk, keepidle);
2303 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2304 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2305 
2306 	/* TCP user timeout (see RFC5482) */
2307 	tcp_sock_set_user_timeout(sock->sk, timeo);
2308 
2309 	/* Connect timeout */
2310 	connect_timeout = max_t(unsigned long,
2311 				DIV_ROUND_UP(xprt->connect_timeout, HZ), 1);
2312 	syn_retries = max_t(unsigned long,
2313 			    READ_ONCE(net->ipv4.sysctl_tcp_syn_retries), 1);
2314 	for (t = 0; t <= syn_retries && (1UL << t) < connect_timeout; t++)
2315 		;
2316 	if (t <= syn_retries)
2317 		tcp_sock_set_syncnt(sock->sk, t - 1);
2318 }
2319 
2320 static void xs_tcp_do_set_connect_timeout(struct rpc_xprt *xprt,
2321 					  unsigned long connect_timeout)
2322 {
2323 	struct sock_xprt *transport =
2324 		container_of(xprt, struct sock_xprt, xprt);
2325 	struct rpc_timeout to;
2326 	unsigned long initval;
2327 
2328 	memcpy(&to, xprt->timeout, sizeof(to));
2329 	/* Arbitrary lower limit */
2330 	initval = max_t(unsigned long, connect_timeout, XS_TCP_INIT_REEST_TO);
2331 	to.to_initval = initval;
2332 	to.to_maxval = initval;
2333 	to.to_retries = 0;
2334 	memcpy(&transport->tcp_timeout, &to, sizeof(transport->tcp_timeout));
2335 	xprt->timeout = &transport->tcp_timeout;
2336 	xprt->connect_timeout = connect_timeout;
2337 }
2338 
2339 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2340 		unsigned long connect_timeout,
2341 		unsigned long reconnect_timeout)
2342 {
2343 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2344 
2345 	spin_lock(&xprt->transport_lock);
2346 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2347 		xprt->max_reconnect_timeout = reconnect_timeout;
2348 	if (connect_timeout < xprt->connect_timeout)
2349 		xs_tcp_do_set_connect_timeout(xprt, connect_timeout);
2350 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2351 	spin_unlock(&xprt->transport_lock);
2352 }
2353 
2354 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2355 {
2356 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2357 
2358 	if (!transport->inet) {
2359 		struct sock *sk = sock->sk;
2360 
2361 		/* Avoid temporary address, they are bad for long-lived
2362 		 * connections such as NFS mounts.
2363 		 * RFC4941, section 3.6 suggests that:
2364 		 *    Individual applications, which have specific
2365 		 *    knowledge about the normal duration of connections,
2366 		 *    MAY override this as appropriate.
2367 		 */
2368 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2369 			ip6_sock_set_addr_preferences(sk,
2370 				IPV6_PREFER_SRC_PUBLIC);
2371 		}
2372 
2373 		xs_tcp_set_socket_timeouts(xprt, sock);
2374 		tcp_sock_set_nodelay(sk);
2375 
2376 		lock_sock(sk);
2377 
2378 		xs_save_old_callbacks(transport, sk);
2379 
2380 		sk->sk_user_data = xprt;
2381 		sk->sk_data_ready = xs_data_ready;
2382 		sk->sk_state_change = xs_tcp_state_change;
2383 		sk->sk_write_space = xs_tcp_write_space;
2384 		sk->sk_error_report = xs_error_report;
2385 		sk->sk_use_task_frag = false;
2386 
2387 		/* socket options */
2388 		sock_reset_flag(sk, SOCK_LINGER);
2389 
2390 		xprt_clear_connected(xprt);
2391 
2392 		/* Reset to new socket */
2393 		transport->sock = sock;
2394 		transport->inet = sk;
2395 
2396 		release_sock(sk);
2397 	}
2398 
2399 	if (!xprt_bound(xprt))
2400 		return -ENOTCONN;
2401 
2402 	xs_set_memalloc(xprt);
2403 
2404 	xs_stream_start_connect(transport);
2405 
2406 	/* Tell the socket layer to start connecting... */
2407 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2408 	return kernel_connect(sock, (struct sockaddr_unsized *)xs_addr(xprt),
2409 			      xprt->addrlen, O_NONBLOCK);
2410 }
2411 
2412 /**
2413  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2414  * @work: queued work item
2415  *
2416  * Invoked by a work queue tasklet.
2417  */
2418 static void xs_tcp_setup_socket(struct work_struct *work)
2419 {
2420 	struct sock_xprt *transport =
2421 		container_of(work, struct sock_xprt, connect_worker.work);
2422 	struct socket *sock = transport->sock;
2423 	struct rpc_xprt *xprt = &transport->xprt;
2424 	int status;
2425 	unsigned int pflags = current->flags;
2426 
2427 	if (atomic_read(&xprt->swapper))
2428 		current->flags |= PF_MEMALLOC;
2429 
2430 	if (xprt_connected(xprt))
2431 		goto out;
2432 	if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,
2433 			       &transport->sock_state) ||
2434 	    !sock) {
2435 		xs_reset_transport(transport);
2436 		sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
2437 				      SOCK_STREAM, IPPROTO_TCP, true);
2438 		if (IS_ERR(sock)) {
2439 			xprt_wake_pending_tasks(xprt, PTR_ERR(sock));
2440 			goto out;
2441 		}
2442 	}
2443 
2444 	dprintk("RPC:       worker connecting xprt %p via %s to "
2445 				"%s (port %s)\n", xprt,
2446 			xprt->address_strings[RPC_DISPLAY_PROTO],
2447 			xprt->address_strings[RPC_DISPLAY_ADDR],
2448 			xprt->address_strings[RPC_DISPLAY_PORT]);
2449 
2450 	status = xs_tcp_finish_connecting(xprt, sock);
2451 	trace_rpc_socket_connect(xprt, sock, status);
2452 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2453 			xprt, -status, xprt_connected(xprt),
2454 			sock->sk->sk_state);
2455 	switch (status) {
2456 	case 0:
2457 	case -EINPROGRESS:
2458 		/* SYN_SENT! */
2459 		set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
2460 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2461 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2462 		fallthrough;
2463 	case -EALREADY:
2464 		goto out_unlock;
2465 	case -EADDRNOTAVAIL:
2466 		/* Source port number is unavailable. Try a new one! */
2467 		transport->srcport = 0;
2468 		status = -EAGAIN;
2469 		break;
2470 	case -EPERM:
2471 		/* Happens, for instance, if a BPF program is preventing
2472 		 * the connect. Remap the error so upper layers can better
2473 		 * deal with it.
2474 		 */
2475 		status = -ECONNREFUSED;
2476 		fallthrough;
2477 	case -EINVAL:
2478 		/* Happens, for instance, if the user specified a link
2479 		 * local IPv6 address without a scope-id.
2480 		 */
2481 	case -ECONNREFUSED:
2482 	case -ECONNRESET:
2483 	case -ENETDOWN:
2484 	case -ENETUNREACH:
2485 	case -EHOSTUNREACH:
2486 	case -EADDRINUSE:
2487 	case -ENOBUFS:
2488 	case -ENOTCONN:
2489 		break;
2490 	default:
2491 		printk("%s: connect returned unhandled error %d\n",
2492 			__func__, status);
2493 		status = -EAGAIN;
2494 	}
2495 
2496 	/* xs_tcp_force_close() wakes tasks with a fixed error code.
2497 	 * We need to wake them first to ensure the correct error code.
2498 	 */
2499 	xprt_wake_pending_tasks(xprt, status);
2500 	xs_tcp_force_close(xprt);
2501 out:
2502 	xprt_clear_connecting(xprt);
2503 out_unlock:
2504 	xprt_unlock_connect(xprt, transport);
2505 	current_restore_flags(pflags, PF_MEMALLOC);
2506 }
2507 
2508 /*
2509  * Transfer the connected socket to @upper_transport, then mark that
2510  * xprt CONNECTED.
2511  */
2512 static int xs_tcp_tls_finish_connecting(struct rpc_xprt *lower_xprt,
2513 					struct sock_xprt *upper_transport)
2514 {
2515 	struct sock_xprt *lower_transport =
2516 			container_of(lower_xprt, struct sock_xprt, xprt);
2517 	struct rpc_xprt *upper_xprt = &upper_transport->xprt;
2518 
2519 	if (!upper_transport->inet) {
2520 		struct socket *sock = lower_transport->sock;
2521 		struct sock *sk = sock->sk;
2522 
2523 		/* Avoid temporary address, they are bad for long-lived
2524 		 * connections such as NFS mounts.
2525 		 * RFC4941, section 3.6 suggests that:
2526 		 *    Individual applications, which have specific
2527 		 *    knowledge about the normal duration of connections,
2528 		 *    MAY override this as appropriate.
2529 		 */
2530 		if (xs_addr(upper_xprt)->sa_family == PF_INET6)
2531 			ip6_sock_set_addr_preferences(sk, IPV6_PREFER_SRC_PUBLIC);
2532 
2533 		xs_tcp_set_socket_timeouts(upper_xprt, sock);
2534 		tcp_sock_set_nodelay(sk);
2535 
2536 		lock_sock(sk);
2537 
2538 		/* @sk is already connected, so it now has the RPC callbacks.
2539 		 * Reach into @lower_transport to save the original ones.
2540 		 */
2541 		upper_transport->old_data_ready = lower_transport->old_data_ready;
2542 		upper_transport->old_state_change = lower_transport->old_state_change;
2543 		upper_transport->old_write_space = lower_transport->old_write_space;
2544 		upper_transport->old_error_report = lower_transport->old_error_report;
2545 		sk->sk_user_data = upper_xprt;
2546 
2547 		/* socket options */
2548 		sock_reset_flag(sk, SOCK_LINGER);
2549 
2550 		xprt_clear_connected(upper_xprt);
2551 
2552 		upper_transport->sock = sock;
2553 		upper_transport->inet = sk;
2554 		upper_transport->file = lower_transport->file;
2555 
2556 		release_sock(sk);
2557 
2558 		/* Reset lower_transport before shutting down its clnt */
2559 		mutex_lock(&lower_transport->recv_mutex);
2560 		lower_transport->inet = NULL;
2561 		lower_transport->sock = NULL;
2562 		lower_transport->file = NULL;
2563 
2564 		xprt_clear_connected(lower_xprt);
2565 		xs_sock_reset_connection_flags(lower_xprt);
2566 		xs_stream_reset_connect(lower_transport);
2567 		mutex_unlock(&lower_transport->recv_mutex);
2568 	}
2569 
2570 	if (!xprt_bound(upper_xprt))
2571 		return -ENOTCONN;
2572 
2573 	xs_set_memalloc(upper_xprt);
2574 
2575 	if (!xprt_test_and_set_connected(upper_xprt)) {
2576 		upper_xprt->connect_cookie++;
2577 		clear_bit(XPRT_SOCK_CONNECTING, &upper_transport->sock_state);
2578 		xprt_clear_connecting(upper_xprt);
2579 
2580 		upper_xprt->stat.connect_count++;
2581 		upper_xprt->stat.connect_time += (long)jiffies -
2582 					   upper_xprt->stat.connect_start;
2583 		xs_run_error_worker(upper_transport, XPRT_SOCK_WAKE_PENDING);
2584 	}
2585 	return 0;
2586 }
2587 
2588 /**
2589  * xs_tls_handshake_done - TLS handshake completion handler
2590  * @data: address of xprt to wake
2591  * @status: status of handshake
2592  * @peerid: serial number of key containing the remote's identity
2593  *
2594  */
2595 static void xs_tls_handshake_done(void *data, int status, key_serial_t peerid)
2596 {
2597 	struct rpc_xprt *lower_xprt = data;
2598 	struct sock_xprt *lower_transport =
2599 				container_of(lower_xprt, struct sock_xprt, xprt);
2600 
2601 	switch (status) {
2602 	case 0:
2603 	case -EACCES:
2604 	case -ETIMEDOUT:
2605 		lower_transport->xprt_err = status;
2606 		break;
2607 	default:
2608 		lower_transport->xprt_err = -EACCES;
2609 	}
2610 	complete(&lower_transport->handshake_done);
2611 	xprt_put(lower_xprt);
2612 }
2613 
2614 static int xs_tls_handshake_sync(struct rpc_xprt *lower_xprt, struct xprtsec_parms *xprtsec)
2615 {
2616 	struct sock_xprt *lower_transport =
2617 				container_of(lower_xprt, struct sock_xprt, xprt);
2618 	struct tls_handshake_args args = {
2619 		.ta_sock	= lower_transport->sock,
2620 		.ta_done	= xs_tls_handshake_done,
2621 		.ta_data	= xprt_get(lower_xprt),
2622 		.ta_peername	= lower_xprt->servername,
2623 	};
2624 	struct sock *sk = lower_transport->inet;
2625 	int rc;
2626 
2627 	init_completion(&lower_transport->handshake_done);
2628 	set_bit(XPRT_SOCK_IGNORE_RECV, &lower_transport->sock_state);
2629 	lower_transport->xprt_err = -ETIMEDOUT;
2630 	switch (xprtsec->policy) {
2631 	case RPC_XPRTSEC_TLS_ANON:
2632 		rc = tls_client_hello_anon(&args, GFP_KERNEL);
2633 		if (rc)
2634 			goto out_put_xprt;
2635 		break;
2636 	case RPC_XPRTSEC_TLS_X509:
2637 		args.ta_my_cert = xprtsec->cert_serial;
2638 		args.ta_my_privkey = xprtsec->privkey_serial;
2639 		rc = tls_client_hello_x509(&args, GFP_KERNEL);
2640 		if (rc)
2641 			goto out_put_xprt;
2642 		break;
2643 	default:
2644 		rc = -EACCES;
2645 		goto out_put_xprt;
2646 	}
2647 
2648 	rc = wait_for_completion_interruptible_timeout(&lower_transport->handshake_done,
2649 						       XS_TLS_HANDSHAKE_TO);
2650 	if (rc <= 0) {
2651 		tls_handshake_cancel(sk);
2652 		if (rc == 0)
2653 			rc = -ETIMEDOUT;
2654 		goto out_put_xprt;
2655 	}
2656 
2657 	rc = lower_transport->xprt_err;
2658 
2659 out:
2660 	xs_stream_reset_connect(lower_transport);
2661 	clear_bit(XPRT_SOCK_IGNORE_RECV, &lower_transport->sock_state);
2662 	return rc;
2663 
2664 out_put_xprt:
2665 	xprt_put(lower_xprt);
2666 	goto out;
2667 }
2668 
2669 /**
2670  * xs_tcp_tls_setup_socket - establish a TLS session on a TCP socket
2671  * @work: queued work item
2672  *
2673  * Invoked by a work queue tasklet.
2674  *
2675  * For RPC-with-TLS, there is a two-stage connection process.
2676  *
2677  * The "upper-layer xprt" is visible to the RPC consumer. Once it has
2678  * been marked connected, the consumer knows that a TCP connection and
2679  * a TLS session have been established.
2680  *
2681  * A "lower-layer xprt", created in this function, handles the mechanics
2682  * of connecting the TCP socket, performing the RPC_AUTH_TLS probe, and
2683  * then driving the TLS handshake. Once all that is complete, the upper
2684  * layer xprt is marked connected.
2685  */
2686 static void xs_tcp_tls_setup_socket(struct work_struct *work)
2687 {
2688 	struct sock_xprt *upper_transport =
2689 		container_of(work, struct sock_xprt, connect_worker.work);
2690 	struct rpc_clnt *upper_clnt = upper_transport->clnt;
2691 	struct rpc_xprt *upper_xprt = &upper_transport->xprt;
2692 	struct rpc_create_args args = {
2693 		.net		= upper_xprt->xprt_net,
2694 		.protocol	= upper_xprt->prot,
2695 		.address	= (struct sockaddr *)&upper_xprt->addr,
2696 		.addrsize	= upper_xprt->addrlen,
2697 		.timeout	= upper_clnt->cl_timeout,
2698 		.servername	= upper_xprt->servername,
2699 		.program	= upper_clnt->cl_program,
2700 		.prognumber	= upper_clnt->cl_prog,
2701 		.version	= upper_clnt->cl_vers,
2702 		.authflavor	= RPC_AUTH_TLS,
2703 		.cred		= upper_clnt->cl_cred,
2704 		.xprtsec	= {
2705 			.policy		= RPC_XPRTSEC_NONE,
2706 		},
2707 		.stats		= upper_clnt->cl_stats,
2708 	};
2709 	unsigned int pflags = current->flags;
2710 	struct rpc_clnt *lower_clnt;
2711 	struct rpc_xprt *lower_xprt;
2712 	int status;
2713 
2714 	if (atomic_read(&upper_xprt->swapper))
2715 		current->flags |= PF_MEMALLOC;
2716 
2717 	xs_stream_start_connect(upper_transport);
2718 
2719 	/* This implicitly sends an RPC_AUTH_TLS probe */
2720 	lower_clnt = rpc_create(&args);
2721 	if (IS_ERR(lower_clnt)) {
2722 		trace_rpc_tls_unavailable(upper_clnt, upper_xprt);
2723 		clear_bit(XPRT_SOCK_CONNECTING, &upper_transport->sock_state);
2724 		xprt_clear_connecting(upper_xprt);
2725 		xprt_wake_pending_tasks(upper_xprt, PTR_ERR(lower_clnt));
2726 		xs_run_error_worker(upper_transport, XPRT_SOCK_WAKE_PENDING);
2727 		goto out_unlock;
2728 	}
2729 
2730 	/* RPC_AUTH_TLS probe was successful. Try a TLS handshake on
2731 	 * the lower xprt.
2732 	 */
2733 	rcu_read_lock();
2734 	lower_xprt = rcu_dereference(lower_clnt->cl_xprt);
2735 	rcu_read_unlock();
2736 
2737 	if (wait_on_bit_lock(&lower_xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2738 		goto out_unlock;
2739 
2740 	status = xs_tls_handshake_sync(lower_xprt, &upper_xprt->xprtsec);
2741 	if (status) {
2742 		trace_rpc_tls_not_started(upper_clnt, upper_xprt);
2743 		goto out_close;
2744 	}
2745 
2746 	status = xs_tcp_tls_finish_connecting(lower_xprt, upper_transport);
2747 	if (status)
2748 		goto out_close;
2749 	xprt_release_write(lower_xprt, NULL);
2750 	trace_rpc_socket_connect(upper_xprt, upper_transport->sock, 0);
2751 	rpc_shutdown_client(lower_clnt);
2752 
2753 	/* Check for ingress data that arrived before the socket's
2754 	 * ->data_ready callback was set up.
2755 	 */
2756 	xs_poll_check_readable(upper_transport);
2757 
2758 out_unlock:
2759 	current_restore_flags(pflags, PF_MEMALLOC);
2760 	upper_transport->clnt = NULL;
2761 	xprt_unlock_connect(upper_xprt, upper_transport);
2762 	return;
2763 
2764 out_close:
2765 	xprt_release_write(lower_xprt, NULL);
2766 	rpc_shutdown_client(lower_clnt);
2767 
2768 	/* xprt_force_disconnect() wakes tasks with a fixed tk_status code.
2769 	 * Wake them first here to ensure they get our tk_status code.
2770 	 */
2771 	xprt_wake_pending_tasks(upper_xprt, status);
2772 	xs_tcp_force_close(upper_xprt);
2773 	xprt_clear_connecting(upper_xprt);
2774 	goto out_unlock;
2775 }
2776 
2777 /**
2778  * xs_connect - connect a socket to a remote endpoint
2779  * @xprt: pointer to transport structure
2780  * @task: address of RPC task that manages state of connect request
2781  *
2782  * TCP: If the remote end dropped the connection, delay reconnecting.
2783  *
2784  * UDP socket connects are synchronous, but we use a work queue anyway
2785  * to guarantee that even unprivileged user processes can set up a
2786  * socket on a privileged port.
2787  *
2788  * If a UDP socket connect fails, the delay behavior here prevents
2789  * retry floods (hard mounts).
2790  */
2791 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2792 {
2793 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2794 	unsigned long delay = 0;
2795 
2796 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2797 
2798 	if (transport->sock != NULL) {
2799 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2800 			"seconds\n", xprt, xprt->reestablish_timeout / HZ);
2801 
2802 		delay = xprt_reconnect_delay(xprt);
2803 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2804 
2805 	} else
2806 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2807 
2808 	transport->clnt = task->tk_client;
2809 	queue_delayed_work(xprtiod_workqueue,
2810 			&transport->connect_worker,
2811 			delay);
2812 }
2813 
2814 static void xs_wake_disconnect(struct sock_xprt *transport)
2815 {
2816 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2817 		xs_tcp_force_close(&transport->xprt);
2818 }
2819 
2820 static void xs_wake_write(struct sock_xprt *transport)
2821 {
2822 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2823 		xprt_write_space(&transport->xprt);
2824 }
2825 
2826 static void xs_wake_error(struct sock_xprt *transport)
2827 {
2828 	int sockerr;
2829 
2830 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2831 		return;
2832 	sockerr = xchg(&transport->xprt_err, 0);
2833 	if (sockerr < 0) {
2834 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2835 		xs_tcp_force_close(&transport->xprt);
2836 	}
2837 }
2838 
2839 static void xs_wake_pending(struct sock_xprt *transport)
2840 {
2841 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2842 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2843 }
2844 
2845 static void xs_error_handle(struct work_struct *work)
2846 {
2847 	struct sock_xprt *transport = container_of(work,
2848 			struct sock_xprt, error_worker);
2849 
2850 	xs_wake_disconnect(transport);
2851 	xs_wake_write(transport);
2852 	xs_wake_error(transport);
2853 	xs_wake_pending(transport);
2854 }
2855 
2856 /**
2857  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2858  * @xprt: rpc_xprt struct containing statistics
2859  * @seq: output file
2860  *
2861  */
2862 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2863 {
2864 	long idle_time = 0;
2865 
2866 	if (xprt_connected(xprt))
2867 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2868 
2869 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2870 			"%llu %llu %lu %llu %llu\n",
2871 			xprt->stat.bind_count,
2872 			xprt->stat.connect_count,
2873 			xprt->stat.connect_time / HZ,
2874 			idle_time,
2875 			xprt->stat.sends,
2876 			xprt->stat.recvs,
2877 			xprt->stat.bad_xids,
2878 			xprt->stat.req_u,
2879 			xprt->stat.bklog_u,
2880 			xprt->stat.max_slots,
2881 			xprt->stat.sending_u,
2882 			xprt->stat.pending_u);
2883 }
2884 
2885 /**
2886  * xs_udp_print_stats - display UDP socket-specific stats
2887  * @xprt: rpc_xprt struct containing statistics
2888  * @seq: output file
2889  *
2890  */
2891 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2892 {
2893 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2894 
2895 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2896 			"%lu %llu %llu\n",
2897 			transport->srcport,
2898 			xprt->stat.bind_count,
2899 			xprt->stat.sends,
2900 			xprt->stat.recvs,
2901 			xprt->stat.bad_xids,
2902 			xprt->stat.req_u,
2903 			xprt->stat.bklog_u,
2904 			xprt->stat.max_slots,
2905 			xprt->stat.sending_u,
2906 			xprt->stat.pending_u);
2907 }
2908 
2909 /**
2910  * xs_tcp_print_stats - display TCP socket-specific stats
2911  * @xprt: rpc_xprt struct containing statistics
2912  * @seq: output file
2913  *
2914  */
2915 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2916 {
2917 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2918 	long idle_time = 0;
2919 
2920 	if (xprt_connected(xprt))
2921 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2922 
2923 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2924 			"%llu %llu %lu %llu %llu\n",
2925 			transport->srcport,
2926 			xprt->stat.bind_count,
2927 			xprt->stat.connect_count,
2928 			xprt->stat.connect_time / HZ,
2929 			idle_time,
2930 			xprt->stat.sends,
2931 			xprt->stat.recvs,
2932 			xprt->stat.bad_xids,
2933 			xprt->stat.req_u,
2934 			xprt->stat.bklog_u,
2935 			xprt->stat.max_slots,
2936 			xprt->stat.sending_u,
2937 			xprt->stat.pending_u);
2938 }
2939 
2940 /*
2941  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2942  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2943  * to use the server side send routines.
2944  */
2945 static int bc_malloc(struct rpc_task *task)
2946 {
2947 	struct rpc_rqst *rqst = task->tk_rqstp;
2948 	size_t size = rqst->rq_callsize;
2949 	struct page *page;
2950 	struct rpc_buffer *buf;
2951 
2952 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2953 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2954 			  size);
2955 		return -EINVAL;
2956 	}
2957 
2958 	page = alloc_page(GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN);
2959 	if (!page)
2960 		return -ENOMEM;
2961 
2962 	buf = page_address(page);
2963 	buf->len = PAGE_SIZE;
2964 
2965 	rqst->rq_buffer = buf->data;
2966 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2967 	return 0;
2968 }
2969 
2970 /*
2971  * Free the space allocated in the bc_alloc routine
2972  */
2973 static void bc_free(struct rpc_task *task)
2974 {
2975 	void *buffer = task->tk_rqstp->rq_buffer;
2976 	struct rpc_buffer *buf;
2977 
2978 	buf = container_of(buffer, struct rpc_buffer, data);
2979 	free_page((unsigned long)buf);
2980 }
2981 
2982 static int bc_sendto(struct rpc_rqst *req)
2983 {
2984 	struct xdr_buf *xdr = &req->rq_snd_buf;
2985 	struct sock_xprt *transport =
2986 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2987 	struct msghdr msg = {
2988 		.msg_flags	= 0,
2989 	};
2990 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2991 					 (u32)xdr->len);
2992 	unsigned int sent = 0;
2993 	int err;
2994 
2995 	req->rq_xtime = ktime_get();
2996 	err = xdr_alloc_bvec(xdr, rpc_task_gfp_mask());
2997 	if (err < 0)
2998 		return err;
2999 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
3000 	xdr_free_bvec(xdr);
3001 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
3002 		return -EAGAIN;
3003 	return sent;
3004 }
3005 
3006 /**
3007  * bc_send_request - Send a backchannel Call on a TCP socket
3008  * @req: rpc_rqst containing Call message to be sent
3009  *
3010  * xpt_mutex ensures @rqstp's whole message is written to the socket
3011  * without interruption.
3012  *
3013  * Return values:
3014  *   %0 if the message was sent successfully
3015  *   %ENOTCONN if the message was not sent
3016  */
3017 static int bc_send_request(struct rpc_rqst *req)
3018 {
3019 	struct svc_xprt	*xprt;
3020 	int len;
3021 
3022 	/*
3023 	 * Get the server socket associated with this callback xprt
3024 	 */
3025 	xprt = req->rq_xprt->bc_xprt;
3026 
3027 	/*
3028 	 * Grab the mutex to serialize data as the connection is shared
3029 	 * with the fore channel
3030 	 */
3031 	mutex_lock(&xprt->xpt_mutex);
3032 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
3033 		len = -ENOTCONN;
3034 	else
3035 		len = bc_sendto(req);
3036 	mutex_unlock(&xprt->xpt_mutex);
3037 
3038 	if (len > 0)
3039 		len = 0;
3040 
3041 	return len;
3042 }
3043 
3044 static void bc_close(struct rpc_xprt *xprt)
3045 {
3046 	xprt_disconnect_done(xprt);
3047 }
3048 
3049 static void bc_destroy(struct rpc_xprt *xprt)
3050 {
3051 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
3052 
3053 	xs_xprt_free(xprt);
3054 	module_put(THIS_MODULE);
3055 }
3056 
3057 static const struct rpc_xprt_ops xs_local_ops = {
3058 	.reserve_xprt		= xprt_reserve_xprt,
3059 	.release_xprt		= xprt_release_xprt,
3060 	.alloc_slot		= xprt_alloc_slot,
3061 	.free_slot		= xprt_free_slot,
3062 	.rpcbind		= xs_local_rpcbind,
3063 	.set_port		= xs_local_set_port,
3064 	.connect		= xs_local_connect,
3065 	.buf_alloc		= rpc_malloc,
3066 	.buf_free		= rpc_free,
3067 	.prepare_request	= xs_stream_prepare_request,
3068 	.send_request		= xs_local_send_request,
3069 	.abort_send_request	= xs_stream_abort_send_request,
3070 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
3071 	.close			= xs_close,
3072 	.destroy		= xs_destroy,
3073 	.print_stats		= xs_local_print_stats,
3074 	.enable_swap		= xs_enable_swap,
3075 	.disable_swap		= xs_disable_swap,
3076 };
3077 
3078 static const struct rpc_xprt_ops xs_udp_ops = {
3079 	.set_buffer_size	= xs_udp_set_buffer_size,
3080 	.reserve_xprt		= xprt_reserve_xprt_cong,
3081 	.release_xprt		= xprt_release_xprt_cong,
3082 	.alloc_slot		= xprt_alloc_slot,
3083 	.free_slot		= xprt_free_slot,
3084 	.rpcbind		= rpcb_getport_async,
3085 	.set_port		= xs_set_port,
3086 	.connect		= xs_connect,
3087 	.get_srcaddr		= xs_sock_srcaddr,
3088 	.get_srcport		= xs_sock_srcport,
3089 	.buf_alloc		= rpc_malloc,
3090 	.buf_free		= rpc_free,
3091 	.send_request		= xs_udp_send_request,
3092 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
3093 	.timer			= xs_udp_timer,
3094 	.release_request	= xprt_release_rqst_cong,
3095 	.close			= xs_close,
3096 	.destroy		= xs_destroy,
3097 	.print_stats		= xs_udp_print_stats,
3098 	.enable_swap		= xs_enable_swap,
3099 	.disable_swap		= xs_disable_swap,
3100 	.inject_disconnect	= xs_inject_disconnect,
3101 };
3102 
3103 static const struct rpc_xprt_ops xs_tcp_ops = {
3104 	.reserve_xprt		= xprt_reserve_xprt,
3105 	.release_xprt		= xprt_release_xprt,
3106 	.alloc_slot		= xprt_alloc_slot,
3107 	.free_slot		= xprt_free_slot,
3108 	.rpcbind		= rpcb_getport_async,
3109 	.set_port		= xs_set_port,
3110 	.connect		= xs_connect,
3111 	.get_srcaddr		= xs_sock_srcaddr,
3112 	.get_srcport		= xs_sock_srcport,
3113 	.buf_alloc		= rpc_malloc,
3114 	.buf_free		= rpc_free,
3115 	.prepare_request	= xs_stream_prepare_request,
3116 	.send_request		= xs_tcp_send_request,
3117 	.abort_send_request	= xs_stream_abort_send_request,
3118 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
3119 	.close			= xs_tcp_shutdown,
3120 	.destroy		= xs_destroy,
3121 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
3122 	.print_stats		= xs_tcp_print_stats,
3123 	.enable_swap		= xs_enable_swap,
3124 	.disable_swap		= xs_disable_swap,
3125 	.inject_disconnect	= xs_inject_disconnect,
3126 #ifdef CONFIG_SUNRPC_BACKCHANNEL
3127 	.bc_setup		= xprt_setup_bc,
3128 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
3129 	.bc_num_slots		= xprt_bc_max_slots,
3130 	.bc_free_rqst		= xprt_free_bc_rqst,
3131 	.bc_destroy		= xprt_destroy_bc,
3132 #endif
3133 };
3134 
3135 /*
3136  * The rpc_xprt_ops for the server backchannel
3137  */
3138 
3139 static const struct rpc_xprt_ops bc_tcp_ops = {
3140 	.reserve_xprt		= xprt_reserve_xprt,
3141 	.release_xprt		= xprt_release_xprt,
3142 	.alloc_slot		= xprt_alloc_slot,
3143 	.free_slot		= xprt_free_slot,
3144 	.buf_alloc		= bc_malloc,
3145 	.buf_free		= bc_free,
3146 	.send_request		= bc_send_request,
3147 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
3148 	.close			= bc_close,
3149 	.destroy		= bc_destroy,
3150 	.print_stats		= xs_tcp_print_stats,
3151 	.enable_swap		= xs_enable_swap,
3152 	.disable_swap		= xs_disable_swap,
3153 	.inject_disconnect	= xs_inject_disconnect,
3154 };
3155 
3156 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
3157 {
3158 	static const struct sockaddr_in sin = {
3159 		.sin_family		= AF_INET,
3160 		.sin_addr.s_addr	= htonl(INADDR_ANY),
3161 	};
3162 	static const struct sockaddr_in6 sin6 = {
3163 		.sin6_family		= AF_INET6,
3164 		.sin6_addr		= IN6ADDR_ANY_INIT,
3165 	};
3166 
3167 	switch (family) {
3168 	case AF_LOCAL:
3169 		break;
3170 	case AF_INET:
3171 		memcpy(sap, &sin, sizeof(sin));
3172 		break;
3173 	case AF_INET6:
3174 		memcpy(sap, &sin6, sizeof(sin6));
3175 		break;
3176 	default:
3177 		dprintk("RPC:       %s: Bad address family\n", __func__);
3178 		return -EAFNOSUPPORT;
3179 	}
3180 	return 0;
3181 }
3182 
3183 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
3184 				      unsigned int slot_table_size,
3185 				      unsigned int max_slot_table_size)
3186 {
3187 	struct rpc_xprt *xprt;
3188 	struct sock_xprt *new;
3189 
3190 	if (args->addrlen > sizeof(xprt->addr)) {
3191 		dprintk("RPC:       xs_setup_xprt: address too large\n");
3192 		return ERR_PTR(-EBADF);
3193 	}
3194 
3195 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
3196 			max_slot_table_size);
3197 	if (xprt == NULL) {
3198 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
3199 				"rpc_xprt\n");
3200 		return ERR_PTR(-ENOMEM);
3201 	}
3202 
3203 	new = container_of(xprt, struct sock_xprt, xprt);
3204 	mutex_init(&new->recv_mutex);
3205 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
3206 	xprt->addrlen = args->addrlen;
3207 	if (args->srcaddr)
3208 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
3209 	else {
3210 		int err;
3211 		err = xs_init_anyaddr(args->dstaddr->sa_family,
3212 					(struct sockaddr *)&new->srcaddr);
3213 		if (err != 0) {
3214 			xprt_free(xprt);
3215 			return ERR_PTR(err);
3216 		}
3217 	}
3218 
3219 	return xprt;
3220 }
3221 
3222 static const struct rpc_timeout xs_local_default_timeout = {
3223 	.to_initval = 10 * HZ,
3224 	.to_maxval = 10 * HZ,
3225 	.to_retries = 2,
3226 };
3227 
3228 /**
3229  * xs_setup_local - Set up transport to use an AF_LOCAL socket
3230  * @args: rpc transport creation arguments
3231  *
3232  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
3233  */
3234 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
3235 {
3236 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
3237 	struct sock_xprt *transport;
3238 	struct rpc_xprt *xprt;
3239 	struct rpc_xprt *ret;
3240 
3241 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3242 			xprt_max_tcp_slot_table_entries);
3243 	if (IS_ERR(xprt))
3244 		return xprt;
3245 	transport = container_of(xprt, struct sock_xprt, xprt);
3246 
3247 	xprt->prot = 0;
3248 	xprt->xprt_class = &xs_local_transport;
3249 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3250 
3251 	xprt->bind_timeout = XS_BIND_TO;
3252 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3253 	xprt->idle_timeout = XS_IDLE_DISC_TO;
3254 
3255 	xprt->ops = &xs_local_ops;
3256 	xprt->timeout = &xs_local_default_timeout;
3257 
3258 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
3259 	INIT_WORK(&transport->error_worker, xs_error_handle);
3260 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
3261 
3262 	switch (sun->sun_family) {
3263 	case AF_LOCAL:
3264 		if (sun->sun_path[0] != '/' && sun->sun_path[0] != '\0') {
3265 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
3266 					sun->sun_path);
3267 			ret = ERR_PTR(-EINVAL);
3268 			goto out_err;
3269 		}
3270 		xprt_set_bound(xprt);
3271 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
3272 		break;
3273 	default:
3274 		ret = ERR_PTR(-EAFNOSUPPORT);
3275 		goto out_err;
3276 	}
3277 
3278 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
3279 			xprt->address_strings[RPC_DISPLAY_ADDR]);
3280 
3281 	if (try_module_get(THIS_MODULE))
3282 		return xprt;
3283 	ret = ERR_PTR(-EINVAL);
3284 out_err:
3285 	xs_xprt_free(xprt);
3286 	return ret;
3287 }
3288 
3289 static const struct rpc_timeout xs_udp_default_timeout = {
3290 	.to_initval = 5 * HZ,
3291 	.to_maxval = 30 * HZ,
3292 	.to_increment = 5 * HZ,
3293 	.to_retries = 5,
3294 };
3295 
3296 /**
3297  * xs_setup_udp - Set up transport to use a UDP socket
3298  * @args: rpc transport creation arguments
3299  *
3300  */
3301 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
3302 {
3303 	struct sockaddr *addr = args->dstaddr;
3304 	struct rpc_xprt *xprt;
3305 	struct sock_xprt *transport;
3306 	struct rpc_xprt *ret;
3307 
3308 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
3309 			xprt_udp_slot_table_entries);
3310 	if (IS_ERR(xprt))
3311 		return xprt;
3312 	transport = container_of(xprt, struct sock_xprt, xprt);
3313 
3314 	xprt->prot = IPPROTO_UDP;
3315 	xprt->xprt_class = &xs_udp_transport;
3316 	/* XXX: header size can vary due to auth type, IPv6, etc. */
3317 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
3318 
3319 	xprt->bind_timeout = XS_BIND_TO;
3320 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
3321 	xprt->idle_timeout = XS_IDLE_DISC_TO;
3322 
3323 	xprt->ops = &xs_udp_ops;
3324 
3325 	xprt->timeout = &xs_udp_default_timeout;
3326 
3327 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
3328 	INIT_WORK(&transport->error_worker, xs_error_handle);
3329 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
3330 
3331 	switch (addr->sa_family) {
3332 	case AF_INET:
3333 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3334 			xprt_set_bound(xprt);
3335 
3336 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
3337 		break;
3338 	case AF_INET6:
3339 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3340 			xprt_set_bound(xprt);
3341 
3342 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
3343 		break;
3344 	default:
3345 		ret = ERR_PTR(-EAFNOSUPPORT);
3346 		goto out_err;
3347 	}
3348 
3349 	if (xprt_bound(xprt))
3350 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3351 				xprt->address_strings[RPC_DISPLAY_ADDR],
3352 				xprt->address_strings[RPC_DISPLAY_PORT],
3353 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3354 	else
3355 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3356 				xprt->address_strings[RPC_DISPLAY_ADDR],
3357 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3358 
3359 	if (try_module_get(THIS_MODULE))
3360 		return xprt;
3361 	ret = ERR_PTR(-EINVAL);
3362 out_err:
3363 	xs_xprt_free(xprt);
3364 	return ret;
3365 }
3366 
3367 static const struct rpc_timeout xs_tcp_default_timeout = {
3368 	.to_initval = 60 * HZ,
3369 	.to_maxval = 60 * HZ,
3370 	.to_retries = 2,
3371 };
3372 
3373 /**
3374  * xs_setup_tcp - Set up transport to use a TCP socket
3375  * @args: rpc transport creation arguments
3376  *
3377  */
3378 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
3379 {
3380 	struct sockaddr *addr = args->dstaddr;
3381 	struct rpc_xprt *xprt;
3382 	struct sock_xprt *transport;
3383 	struct rpc_xprt *ret;
3384 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3385 
3386 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3387 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3388 
3389 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3390 			max_slot_table_size);
3391 	if (IS_ERR(xprt))
3392 		return xprt;
3393 	transport = container_of(xprt, struct sock_xprt, xprt);
3394 
3395 	xprt->prot = IPPROTO_TCP;
3396 	xprt->xprt_class = &xs_tcp_transport;
3397 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3398 
3399 	xprt->bind_timeout = XS_BIND_TO;
3400 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3401 	xprt->idle_timeout = XS_IDLE_DISC_TO;
3402 
3403 	xprt->ops = &xs_tcp_ops;
3404 	xprt->timeout = &xs_tcp_default_timeout;
3405 
3406 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3407 	if (args->reconnect_timeout)
3408 		xprt->max_reconnect_timeout = args->reconnect_timeout;
3409 
3410 	xprt->connect_timeout = xprt->timeout->to_initval *
3411 		(xprt->timeout->to_retries + 1);
3412 	if (args->connect_timeout)
3413 		xs_tcp_do_set_connect_timeout(xprt, args->connect_timeout);
3414 
3415 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
3416 	INIT_WORK(&transport->error_worker, xs_error_handle);
3417 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3418 
3419 	switch (addr->sa_family) {
3420 	case AF_INET:
3421 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3422 			xprt_set_bound(xprt);
3423 
3424 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3425 		break;
3426 	case AF_INET6:
3427 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3428 			xprt_set_bound(xprt);
3429 
3430 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3431 		break;
3432 	default:
3433 		ret = ERR_PTR(-EAFNOSUPPORT);
3434 		goto out_err;
3435 	}
3436 
3437 	if (xprt_bound(xprt))
3438 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3439 				xprt->address_strings[RPC_DISPLAY_ADDR],
3440 				xprt->address_strings[RPC_DISPLAY_PORT],
3441 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3442 	else
3443 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3444 				xprt->address_strings[RPC_DISPLAY_ADDR],
3445 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3446 
3447 	if (try_module_get(THIS_MODULE))
3448 		return xprt;
3449 	ret = ERR_PTR(-EINVAL);
3450 out_err:
3451 	xs_xprt_free(xprt);
3452 	return ret;
3453 }
3454 
3455 /**
3456  * xs_setup_tcp_tls - Set up transport to use a TCP with TLS
3457  * @args: rpc transport creation arguments
3458  *
3459  */
3460 static struct rpc_xprt *xs_setup_tcp_tls(struct xprt_create *args)
3461 {
3462 	struct sockaddr *addr = args->dstaddr;
3463 	struct rpc_xprt *xprt;
3464 	struct sock_xprt *transport;
3465 	struct rpc_xprt *ret;
3466 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3467 
3468 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3469 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3470 
3471 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3472 			     max_slot_table_size);
3473 	if (IS_ERR(xprt))
3474 		return xprt;
3475 	transport = container_of(xprt, struct sock_xprt, xprt);
3476 
3477 	xprt->prot = IPPROTO_TCP;
3478 	xprt->xprt_class = &xs_tcp_transport;
3479 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3480 
3481 	xprt->bind_timeout = XS_BIND_TO;
3482 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3483 	xprt->idle_timeout = XS_IDLE_DISC_TO;
3484 
3485 	xprt->ops = &xs_tcp_ops;
3486 	xprt->timeout = &xs_tcp_default_timeout;
3487 
3488 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3489 	xprt->connect_timeout = xprt->timeout->to_initval *
3490 		(xprt->timeout->to_retries + 1);
3491 
3492 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
3493 	INIT_WORK(&transport->error_worker, xs_error_handle);
3494 
3495 	switch (args->xprtsec.policy) {
3496 	case RPC_XPRTSEC_TLS_ANON:
3497 	case RPC_XPRTSEC_TLS_X509:
3498 		xprt->xprtsec = args->xprtsec;
3499 		INIT_DELAYED_WORK(&transport->connect_worker,
3500 				  xs_tcp_tls_setup_socket);
3501 		break;
3502 	default:
3503 		ret = ERR_PTR(-EACCES);
3504 		goto out_err;
3505 	}
3506 
3507 	switch (addr->sa_family) {
3508 	case AF_INET:
3509 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3510 			xprt_set_bound(xprt);
3511 
3512 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3513 		break;
3514 	case AF_INET6:
3515 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3516 			xprt_set_bound(xprt);
3517 
3518 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3519 		break;
3520 	default:
3521 		ret = ERR_PTR(-EAFNOSUPPORT);
3522 		goto out_err;
3523 	}
3524 
3525 	if (xprt_bound(xprt))
3526 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3527 			xprt->address_strings[RPC_DISPLAY_ADDR],
3528 			xprt->address_strings[RPC_DISPLAY_PORT],
3529 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3530 	else
3531 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3532 			xprt->address_strings[RPC_DISPLAY_ADDR],
3533 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3534 
3535 	if (try_module_get(THIS_MODULE))
3536 		return xprt;
3537 	ret = ERR_PTR(-EINVAL);
3538 out_err:
3539 	xs_xprt_free(xprt);
3540 	return ret;
3541 }
3542 
3543 /**
3544  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3545  * @args: rpc transport creation arguments
3546  *
3547  */
3548 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3549 {
3550 	struct sockaddr *addr = args->dstaddr;
3551 	struct rpc_xprt *xprt;
3552 	struct sock_xprt *transport;
3553 	struct svc_sock *bc_sock;
3554 	struct rpc_xprt *ret;
3555 
3556 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3557 			xprt_tcp_slot_table_entries);
3558 	if (IS_ERR(xprt))
3559 		return xprt;
3560 	transport = container_of(xprt, struct sock_xprt, xprt);
3561 
3562 	xprt->prot = IPPROTO_TCP;
3563 	xprt->xprt_class = &xs_bc_tcp_transport;
3564 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3565 	xprt->timeout = &xs_tcp_default_timeout;
3566 
3567 	/* backchannel */
3568 	xprt_set_bound(xprt);
3569 	xprt->bind_timeout = 0;
3570 	xprt->reestablish_timeout = 0;
3571 	xprt->idle_timeout = 0;
3572 
3573 	xprt->ops = &bc_tcp_ops;
3574 
3575 	switch (addr->sa_family) {
3576 	case AF_INET:
3577 		xs_format_peer_addresses(xprt, "tcp",
3578 					 RPCBIND_NETID_TCP);
3579 		break;
3580 	case AF_INET6:
3581 		xs_format_peer_addresses(xprt, "tcp",
3582 				   RPCBIND_NETID_TCP6);
3583 		break;
3584 	default:
3585 		ret = ERR_PTR(-EAFNOSUPPORT);
3586 		goto out_err;
3587 	}
3588 
3589 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3590 			xprt->address_strings[RPC_DISPLAY_ADDR],
3591 			xprt->address_strings[RPC_DISPLAY_PORT],
3592 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3593 
3594 	/*
3595 	 * Once we've associated a backchannel xprt with a connection,
3596 	 * we want to keep it around as long as the connection lasts,
3597 	 * in case we need to start using it for a backchannel again;
3598 	 * this reference won't be dropped until bc_xprt is destroyed.
3599 	 */
3600 	xprt_get(xprt);
3601 	args->bc_xprt->xpt_bc_xprt = xprt;
3602 	xprt->bc_xprt = args->bc_xprt;
3603 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3604 	transport->sock = bc_sock->sk_sock;
3605 	transport->inet = bc_sock->sk_sk;
3606 
3607 	/*
3608 	 * Since we don't want connections for the backchannel, we set
3609 	 * the xprt status to connected
3610 	 */
3611 	xprt_set_connected(xprt);
3612 
3613 	if (try_module_get(THIS_MODULE))
3614 		return xprt;
3615 
3616 	args->bc_xprt->xpt_bc_xprt = NULL;
3617 	args->bc_xprt->xpt_bc_xps = NULL;
3618 	xprt_put(xprt);
3619 	ret = ERR_PTR(-EINVAL);
3620 out_err:
3621 	xs_xprt_free(xprt);
3622 	return ret;
3623 }
3624 
3625 static struct xprt_class	xs_local_transport = {
3626 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3627 	.name		= "named UNIX socket",
3628 	.owner		= THIS_MODULE,
3629 	.ident		= XPRT_TRANSPORT_LOCAL,
3630 	.setup		= xs_setup_local,
3631 	.netid		= { "" },
3632 };
3633 
3634 static struct xprt_class	xs_udp_transport = {
3635 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3636 	.name		= "udp",
3637 	.owner		= THIS_MODULE,
3638 	.ident		= XPRT_TRANSPORT_UDP,
3639 	.setup		= xs_setup_udp,
3640 	.netid		= { "udp", "udp6", "" },
3641 };
3642 
3643 static struct xprt_class	xs_tcp_transport = {
3644 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3645 	.name		= "tcp",
3646 	.owner		= THIS_MODULE,
3647 	.ident		= XPRT_TRANSPORT_TCP,
3648 	.setup		= xs_setup_tcp,
3649 	.netid		= { "tcp", "tcp6", "" },
3650 };
3651 
3652 static struct xprt_class	xs_tcp_tls_transport = {
3653 	.list		= LIST_HEAD_INIT(xs_tcp_tls_transport.list),
3654 	.name		= "tcp-with-tls",
3655 	.owner		= THIS_MODULE,
3656 	.ident		= XPRT_TRANSPORT_TCP_TLS,
3657 	.setup		= xs_setup_tcp_tls,
3658 	.netid		= { "tcp", "tcp6", "" },
3659 };
3660 
3661 static struct xprt_class	xs_bc_tcp_transport = {
3662 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3663 	.name		= "tcp NFSv4.1 backchannel",
3664 	.owner		= THIS_MODULE,
3665 	.ident		= XPRT_TRANSPORT_BC_TCP,
3666 	.setup		= xs_setup_bc_tcp,
3667 	.netid		= { "" },
3668 };
3669 
3670 /**
3671  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3672  *
3673  */
3674 int init_socket_xprt(void)
3675 {
3676 	if (!sunrpc_table_header)
3677 		sunrpc_table_header = register_sysctl("sunrpc", xs_tunables_table);
3678 
3679 	xprt_register_transport(&xs_local_transport);
3680 	xprt_register_transport(&xs_udp_transport);
3681 	xprt_register_transport(&xs_tcp_transport);
3682 	xprt_register_transport(&xs_tcp_tls_transport);
3683 	xprt_register_transport(&xs_bc_tcp_transport);
3684 
3685 	return 0;
3686 }
3687 
3688 /**
3689  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3690  *
3691  */
3692 void cleanup_socket_xprt(void)
3693 {
3694 	if (sunrpc_table_header) {
3695 		unregister_sysctl_table(sunrpc_table_header);
3696 		sunrpc_table_header = NULL;
3697 	}
3698 
3699 	xprt_unregister_transport(&xs_local_transport);
3700 	xprt_unregister_transport(&xs_udp_transport);
3701 	xprt_unregister_transport(&xs_tcp_transport);
3702 	xprt_unregister_transport(&xs_tcp_tls_transport);
3703 	xprt_unregister_transport(&xs_bc_tcp_transport);
3704 }
3705 
3706 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3707 {
3708 	return param_set_uint_minmax(val, kp,
3709 			RPC_MIN_RESVPORT,
3710 			RPC_MAX_RESVPORT);
3711 }
3712 
3713 static const struct kernel_param_ops param_ops_portnr = {
3714 	.set = param_set_portnr,
3715 	.get = param_get_uint,
3716 };
3717 
3718 #define param_check_portnr(name, p) \
3719 	__param_check(name, p, unsigned int);
3720 
3721 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3722 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3723 
3724 static int param_set_slot_table_size(const char *val,
3725 				     const struct kernel_param *kp)
3726 {
3727 	return param_set_uint_minmax(val, kp,
3728 			RPC_MIN_SLOT_TABLE,
3729 			RPC_MAX_SLOT_TABLE);
3730 }
3731 
3732 static const struct kernel_param_ops param_ops_slot_table_size = {
3733 	.set = param_set_slot_table_size,
3734 	.get = param_get_uint,
3735 };
3736 
3737 #define param_check_slot_table_size(name, p) \
3738 	__param_check(name, p, unsigned int);
3739 
3740 static int param_set_max_slot_table_size(const char *val,
3741 				     const struct kernel_param *kp)
3742 {
3743 	return param_set_uint_minmax(val, kp,
3744 			RPC_MIN_SLOT_TABLE,
3745 			RPC_MAX_SLOT_TABLE_LIMIT);
3746 }
3747 
3748 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3749 	.set = param_set_max_slot_table_size,
3750 	.get = param_get_uint,
3751 };
3752 
3753 #define param_check_max_slot_table_size(name, p) \
3754 	__param_check(name, p, unsigned int);
3755 
3756 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3757 		   slot_table_size, 0644);
3758 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3759 		   max_slot_table_size, 0644);
3760 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3761 		   slot_table_size, 0644);
3762