xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 2790a624)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/highmem.h>
52 #include <linux/uio.h>
53 #include <linux/sched/mm.h>
54 
55 #include <trace/events/sunrpc.h>
56 
57 #include "socklib.h"
58 #include "sunrpc.h"
59 
60 static void xs_close(struct rpc_xprt *xprt);
61 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock);
62 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
63 		struct socket *sock);
64 
65 /*
66  * xprtsock tunables
67  */
68 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
69 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
70 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
71 
72 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
73 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
74 
75 #define XS_TCP_LINGER_TO	(15U * HZ)
76 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
77 
78 /*
79  * We can register our own files under /proc/sys/sunrpc by
80  * calling register_sysctl_table() again.  The files in that
81  * directory become the union of all files registered there.
82  *
83  * We simply need to make sure that we don't collide with
84  * someone else's file names!
85  */
86 
87 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
88 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
89 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
90 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
91 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
92 
93 static struct ctl_table_header *sunrpc_table_header;
94 
95 static struct xprt_class xs_local_transport;
96 static struct xprt_class xs_udp_transport;
97 static struct xprt_class xs_tcp_transport;
98 static struct xprt_class xs_bc_tcp_transport;
99 
100 /*
101  * FIXME: changing the UDP slot table size should also resize the UDP
102  *        socket buffers for existing UDP transports
103  */
104 static struct ctl_table xs_tunables_table[] = {
105 	{
106 		.procname	= "udp_slot_table_entries",
107 		.data		= &xprt_udp_slot_table_entries,
108 		.maxlen		= sizeof(unsigned int),
109 		.mode		= 0644,
110 		.proc_handler	= proc_dointvec_minmax,
111 		.extra1		= &min_slot_table_size,
112 		.extra2		= &max_slot_table_size
113 	},
114 	{
115 		.procname	= "tcp_slot_table_entries",
116 		.data		= &xprt_tcp_slot_table_entries,
117 		.maxlen		= sizeof(unsigned int),
118 		.mode		= 0644,
119 		.proc_handler	= proc_dointvec_minmax,
120 		.extra1		= &min_slot_table_size,
121 		.extra2		= &max_slot_table_size
122 	},
123 	{
124 		.procname	= "tcp_max_slot_table_entries",
125 		.data		= &xprt_max_tcp_slot_table_entries,
126 		.maxlen		= sizeof(unsigned int),
127 		.mode		= 0644,
128 		.proc_handler	= proc_dointvec_minmax,
129 		.extra1		= &min_slot_table_size,
130 		.extra2		= &max_tcp_slot_table_limit
131 	},
132 	{
133 		.procname	= "min_resvport",
134 		.data		= &xprt_min_resvport,
135 		.maxlen		= sizeof(unsigned int),
136 		.mode		= 0644,
137 		.proc_handler	= proc_dointvec_minmax,
138 		.extra1		= &xprt_min_resvport_limit,
139 		.extra2		= &xprt_max_resvport_limit
140 	},
141 	{
142 		.procname	= "max_resvport",
143 		.data		= &xprt_max_resvport,
144 		.maxlen		= sizeof(unsigned int),
145 		.mode		= 0644,
146 		.proc_handler	= proc_dointvec_minmax,
147 		.extra1		= &xprt_min_resvport_limit,
148 		.extra2		= &xprt_max_resvport_limit
149 	},
150 	{
151 		.procname	= "tcp_fin_timeout",
152 		.data		= &xs_tcp_fin_timeout,
153 		.maxlen		= sizeof(xs_tcp_fin_timeout),
154 		.mode		= 0644,
155 		.proc_handler	= proc_dointvec_jiffies,
156 	},
157 	{ },
158 };
159 
160 static struct ctl_table sunrpc_table[] = {
161 	{
162 		.procname	= "sunrpc",
163 		.mode		= 0555,
164 		.child		= xs_tunables_table
165 	},
166 	{ },
167 };
168 
169 /*
170  * Wait duration for a reply from the RPC portmapper.
171  */
172 #define XS_BIND_TO		(60U * HZ)
173 
174 /*
175  * Delay if a UDP socket connect error occurs.  This is most likely some
176  * kind of resource problem on the local host.
177  */
178 #define XS_UDP_REEST_TO		(2U * HZ)
179 
180 /*
181  * The reestablish timeout allows clients to delay for a bit before attempting
182  * to reconnect to a server that just dropped our connection.
183  *
184  * We implement an exponential backoff when trying to reestablish a TCP
185  * transport connection with the server.  Some servers like to drop a TCP
186  * connection when they are overworked, so we start with a short timeout and
187  * increase over time if the server is down or not responding.
188  */
189 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
190 
191 /*
192  * TCP idle timeout; client drops the transport socket if it is idle
193  * for this long.  Note that we also timeout UDP sockets to prevent
194  * holding port numbers when there is no RPC traffic.
195  */
196 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
197 
198 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
199 # undef  RPC_DEBUG_DATA
200 # define RPCDBG_FACILITY	RPCDBG_TRANS
201 #endif
202 
203 #ifdef RPC_DEBUG_DATA
204 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
205 {
206 	u8 *buf = (u8 *) packet;
207 	int j;
208 
209 	dprintk("RPC:       %s\n", msg);
210 	for (j = 0; j < count && j < 128; j += 4) {
211 		if (!(j & 31)) {
212 			if (j)
213 				dprintk("\n");
214 			dprintk("0x%04x ", j);
215 		}
216 		dprintk("%02x%02x%02x%02x ",
217 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
218 	}
219 	dprintk("\n");
220 }
221 #else
222 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
223 {
224 	/* NOP */
225 }
226 #endif
227 
228 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
229 {
230 	return (struct rpc_xprt *) sk->sk_user_data;
231 }
232 
233 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_un *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in *) &xprt->addr;
246 }
247 
248 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
249 {
250 	return (struct sockaddr_in6 *) &xprt->addr;
251 }
252 
253 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
254 {
255 	struct sockaddr *sap = xs_addr(xprt);
256 	struct sockaddr_in6 *sin6;
257 	struct sockaddr_in *sin;
258 	struct sockaddr_un *sun;
259 	char buf[128];
260 
261 	switch (sap->sa_family) {
262 	case AF_LOCAL:
263 		sun = xs_addr_un(xprt);
264 		strlcpy(buf, sun->sun_path, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		break;
268 	case AF_INET:
269 		(void)rpc_ntop(sap, buf, sizeof(buf));
270 		xprt->address_strings[RPC_DISPLAY_ADDR] =
271 						kstrdup(buf, GFP_KERNEL);
272 		sin = xs_addr_in(xprt);
273 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
274 		break;
275 	case AF_INET6:
276 		(void)rpc_ntop(sap, buf, sizeof(buf));
277 		xprt->address_strings[RPC_DISPLAY_ADDR] =
278 						kstrdup(buf, GFP_KERNEL);
279 		sin6 = xs_addr_in6(xprt);
280 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
281 		break;
282 	default:
283 		BUG();
284 	}
285 
286 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
287 }
288 
289 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
290 {
291 	struct sockaddr *sap = xs_addr(xprt);
292 	char buf[128];
293 
294 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
295 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
296 
297 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
298 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
299 }
300 
301 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
302 				     const char *protocol,
303 				     const char *netid)
304 {
305 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
306 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
307 	xs_format_common_peer_addresses(xprt);
308 	xs_format_common_peer_ports(xprt);
309 }
310 
311 static void xs_update_peer_port(struct rpc_xprt *xprt)
312 {
313 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
314 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
315 
316 	xs_format_common_peer_ports(xprt);
317 }
318 
319 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
320 {
321 	unsigned int i;
322 
323 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
324 		switch (i) {
325 		case RPC_DISPLAY_PROTO:
326 		case RPC_DISPLAY_NETID:
327 			continue;
328 		default:
329 			kfree(xprt->address_strings[i]);
330 		}
331 }
332 
333 static size_t
334 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
335 {
336 	size_t i,n;
337 
338 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
339 		return want;
340 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
341 	for (i = 0; i < n; i++) {
342 		if (buf->pages[i])
343 			continue;
344 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
345 		if (!buf->pages[i]) {
346 			i *= PAGE_SIZE;
347 			return i > buf->page_base ? i - buf->page_base : 0;
348 		}
349 	}
350 	return want;
351 }
352 
353 static ssize_t
354 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
355 {
356 	ssize_t ret;
357 	if (seek != 0)
358 		iov_iter_advance(&msg->msg_iter, seek);
359 	ret = sock_recvmsg(sock, msg, flags);
360 	return ret > 0 ? ret + seek : ret;
361 }
362 
363 static ssize_t
364 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
365 		struct kvec *kvec, size_t count, size_t seek)
366 {
367 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
368 	return xs_sock_recvmsg(sock, msg, flags, seek);
369 }
370 
371 static ssize_t
372 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
373 		struct bio_vec *bvec, unsigned long nr, size_t count,
374 		size_t seek)
375 {
376 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
377 	return xs_sock_recvmsg(sock, msg, flags, seek);
378 }
379 
380 static ssize_t
381 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
382 		size_t count)
383 {
384 	iov_iter_discard(&msg->msg_iter, READ, count);
385 	return sock_recvmsg(sock, msg, flags);
386 }
387 
388 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
389 static void
390 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
391 {
392 	struct bvec_iter bi = {
393 		.bi_size = count,
394 	};
395 	struct bio_vec bv;
396 
397 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
398 	for_each_bvec(bv, bvec, bi, bi)
399 		flush_dcache_page(bv.bv_page);
400 }
401 #else
402 static inline void
403 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
404 {
405 }
406 #endif
407 
408 static ssize_t
409 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
410 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
411 {
412 	size_t want, seek_init = seek, offset = 0;
413 	ssize_t ret;
414 
415 	want = min_t(size_t, count, buf->head[0].iov_len);
416 	if (seek < want) {
417 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
418 		if (ret <= 0)
419 			goto sock_err;
420 		offset += ret;
421 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
422 			goto out;
423 		if (ret != want)
424 			goto out;
425 		seek = 0;
426 	} else {
427 		seek -= want;
428 		offset += want;
429 	}
430 
431 	want = xs_alloc_sparse_pages(buf,
432 			min_t(size_t, count - offset, buf->page_len),
433 			GFP_KERNEL);
434 	if (seek < want) {
435 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
436 				xdr_buf_pagecount(buf),
437 				want + buf->page_base,
438 				seek + buf->page_base);
439 		if (ret <= 0)
440 			goto sock_err;
441 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
442 		ret -= buf->page_base;
443 		offset += ret;
444 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
445 			goto out;
446 		if (ret != want)
447 			goto out;
448 		seek = 0;
449 	} else {
450 		seek -= want;
451 		offset += want;
452 	}
453 
454 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
455 	if (seek < want) {
456 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
457 		if (ret <= 0)
458 			goto sock_err;
459 		offset += ret;
460 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
461 			goto out;
462 		if (ret != want)
463 			goto out;
464 	} else if (offset < seek_init)
465 		offset = seek_init;
466 	ret = -EMSGSIZE;
467 out:
468 	*read = offset - seek_init;
469 	return ret;
470 sock_err:
471 	offset += seek;
472 	goto out;
473 }
474 
475 static void
476 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
477 {
478 	if (!transport->recv.copied) {
479 		if (buf->head[0].iov_len >= transport->recv.offset)
480 			memcpy(buf->head[0].iov_base,
481 					&transport->recv.xid,
482 					transport->recv.offset);
483 		transport->recv.copied = transport->recv.offset;
484 	}
485 }
486 
487 static bool
488 xs_read_stream_request_done(struct sock_xprt *transport)
489 {
490 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
491 }
492 
493 static void
494 xs_read_stream_check_eor(struct sock_xprt *transport,
495 		struct msghdr *msg)
496 {
497 	if (xs_read_stream_request_done(transport))
498 		msg->msg_flags |= MSG_EOR;
499 }
500 
501 static ssize_t
502 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
503 		int flags, struct rpc_rqst *req)
504 {
505 	struct xdr_buf *buf = &req->rq_private_buf;
506 	size_t want, read;
507 	ssize_t ret;
508 
509 	xs_read_header(transport, buf);
510 
511 	want = transport->recv.len - transport->recv.offset;
512 	if (want != 0) {
513 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
514 				transport->recv.copied + want,
515 				transport->recv.copied,
516 				&read);
517 		transport->recv.offset += read;
518 		transport->recv.copied += read;
519 	}
520 
521 	if (transport->recv.offset == transport->recv.len)
522 		xs_read_stream_check_eor(transport, msg);
523 
524 	if (want == 0)
525 		return 0;
526 
527 	switch (ret) {
528 	default:
529 		break;
530 	case -EFAULT:
531 	case -EMSGSIZE:
532 		msg->msg_flags |= MSG_TRUNC;
533 		return read;
534 	case 0:
535 		return -ESHUTDOWN;
536 	}
537 	return ret < 0 ? ret : read;
538 }
539 
540 static size_t
541 xs_read_stream_headersize(bool isfrag)
542 {
543 	if (isfrag)
544 		return sizeof(__be32);
545 	return 3 * sizeof(__be32);
546 }
547 
548 static ssize_t
549 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
550 		int flags, size_t want, size_t seek)
551 {
552 	struct kvec kvec = {
553 		.iov_base = &transport->recv.fraghdr,
554 		.iov_len = want,
555 	};
556 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
557 }
558 
559 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
560 static ssize_t
561 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
562 {
563 	struct rpc_xprt *xprt = &transport->xprt;
564 	struct rpc_rqst *req;
565 	ssize_t ret;
566 
567 	/* Is this transport associated with the backchannel? */
568 	if (!xprt->bc_serv)
569 		return -ESHUTDOWN;
570 
571 	/* Look up and lock the request corresponding to the given XID */
572 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
573 	if (!req) {
574 		printk(KERN_WARNING "Callback slot table overflowed\n");
575 		return -ESHUTDOWN;
576 	}
577 	if (transport->recv.copied && !req->rq_private_buf.len)
578 		return -ESHUTDOWN;
579 
580 	ret = xs_read_stream_request(transport, msg, flags, req);
581 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
582 		xprt_complete_bc_request(req, transport->recv.copied);
583 	else
584 		req->rq_private_buf.len = transport->recv.copied;
585 
586 	return ret;
587 }
588 #else /* CONFIG_SUNRPC_BACKCHANNEL */
589 static ssize_t
590 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
591 {
592 	return -ESHUTDOWN;
593 }
594 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
595 
596 static ssize_t
597 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
598 {
599 	struct rpc_xprt *xprt = &transport->xprt;
600 	struct rpc_rqst *req;
601 	ssize_t ret = 0;
602 
603 	/* Look up and lock the request corresponding to the given XID */
604 	spin_lock(&xprt->queue_lock);
605 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
606 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
607 		msg->msg_flags |= MSG_TRUNC;
608 		goto out;
609 	}
610 	xprt_pin_rqst(req);
611 	spin_unlock(&xprt->queue_lock);
612 
613 	ret = xs_read_stream_request(transport, msg, flags, req);
614 
615 	spin_lock(&xprt->queue_lock);
616 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
617 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
618 	else
619 		req->rq_private_buf.len = transport->recv.copied;
620 	xprt_unpin_rqst(req);
621 out:
622 	spin_unlock(&xprt->queue_lock);
623 	return ret;
624 }
625 
626 static ssize_t
627 xs_read_stream(struct sock_xprt *transport, int flags)
628 {
629 	struct msghdr msg = { 0 };
630 	size_t want, read = 0;
631 	ssize_t ret = 0;
632 
633 	if (transport->recv.len == 0) {
634 		want = xs_read_stream_headersize(transport->recv.copied != 0);
635 		ret = xs_read_stream_header(transport, &msg, flags, want,
636 				transport->recv.offset);
637 		if (ret <= 0)
638 			goto out_err;
639 		transport->recv.offset = ret;
640 		if (transport->recv.offset != want)
641 			return transport->recv.offset;
642 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
643 			RPC_FRAGMENT_SIZE_MASK;
644 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
645 		read = ret;
646 	}
647 
648 	switch (be32_to_cpu(transport->recv.calldir)) {
649 	default:
650 		msg.msg_flags |= MSG_TRUNC;
651 		break;
652 	case RPC_CALL:
653 		ret = xs_read_stream_call(transport, &msg, flags);
654 		break;
655 	case RPC_REPLY:
656 		ret = xs_read_stream_reply(transport, &msg, flags);
657 	}
658 	if (msg.msg_flags & MSG_TRUNC) {
659 		transport->recv.calldir = cpu_to_be32(-1);
660 		transport->recv.copied = -1;
661 	}
662 	if (ret < 0)
663 		goto out_err;
664 	read += ret;
665 	if (transport->recv.offset < transport->recv.len) {
666 		if (!(msg.msg_flags & MSG_TRUNC))
667 			return read;
668 		msg.msg_flags = 0;
669 		ret = xs_read_discard(transport->sock, &msg, flags,
670 				transport->recv.len - transport->recv.offset);
671 		if (ret <= 0)
672 			goto out_err;
673 		transport->recv.offset += ret;
674 		read += ret;
675 		if (transport->recv.offset != transport->recv.len)
676 			return read;
677 	}
678 	if (xs_read_stream_request_done(transport)) {
679 		trace_xs_stream_read_request(transport);
680 		transport->recv.copied = 0;
681 	}
682 	transport->recv.offset = 0;
683 	transport->recv.len = 0;
684 	return read;
685 out_err:
686 	return ret != 0 ? ret : -ESHUTDOWN;
687 }
688 
689 static __poll_t xs_poll_socket(struct sock_xprt *transport)
690 {
691 	return transport->sock->ops->poll(transport->file, transport->sock,
692 			NULL);
693 }
694 
695 static bool xs_poll_socket_readable(struct sock_xprt *transport)
696 {
697 	__poll_t events = xs_poll_socket(transport);
698 
699 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
700 }
701 
702 static void xs_poll_check_readable(struct sock_xprt *transport)
703 {
704 
705 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
706 	if (!xs_poll_socket_readable(transport))
707 		return;
708 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
709 		queue_work(xprtiod_workqueue, &transport->recv_worker);
710 }
711 
712 static void xs_stream_data_receive(struct sock_xprt *transport)
713 {
714 	size_t read = 0;
715 	ssize_t ret = 0;
716 
717 	mutex_lock(&transport->recv_mutex);
718 	if (transport->sock == NULL)
719 		goto out;
720 	for (;;) {
721 		ret = xs_read_stream(transport, MSG_DONTWAIT);
722 		if (ret < 0)
723 			break;
724 		read += ret;
725 		cond_resched();
726 	}
727 	if (ret == -ESHUTDOWN)
728 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
729 	else
730 		xs_poll_check_readable(transport);
731 out:
732 	mutex_unlock(&transport->recv_mutex);
733 	trace_xs_stream_read_data(&transport->xprt, ret, read);
734 }
735 
736 static void xs_stream_data_receive_workfn(struct work_struct *work)
737 {
738 	struct sock_xprt *transport =
739 		container_of(work, struct sock_xprt, recv_worker);
740 	unsigned int pflags = memalloc_nofs_save();
741 
742 	xs_stream_data_receive(transport);
743 	memalloc_nofs_restore(pflags);
744 }
745 
746 static void
747 xs_stream_reset_connect(struct sock_xprt *transport)
748 {
749 	transport->recv.offset = 0;
750 	transport->recv.len = 0;
751 	transport->recv.copied = 0;
752 	transport->xmit.offset = 0;
753 }
754 
755 static void
756 xs_stream_start_connect(struct sock_xprt *transport)
757 {
758 	transport->xprt.stat.connect_count++;
759 	transport->xprt.stat.connect_start = jiffies;
760 }
761 
762 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
763 
764 /**
765  * xs_nospace - handle transmit was incomplete
766  * @req: pointer to RPC request
767  * @transport: pointer to struct sock_xprt
768  *
769  */
770 static int xs_nospace(struct rpc_rqst *req, struct sock_xprt *transport)
771 {
772 	struct rpc_xprt *xprt = &transport->xprt;
773 	struct sock *sk = transport->inet;
774 	int ret = -EAGAIN;
775 
776 	trace_rpc_socket_nospace(req, transport);
777 
778 	/* Protect against races with write_space */
779 	spin_lock(&xprt->transport_lock);
780 
781 	/* Don't race with disconnect */
782 	if (xprt_connected(xprt)) {
783 		/* wait for more buffer space */
784 		set_bit(XPRT_SOCK_NOSPACE, &transport->sock_state);
785 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
786 		sk->sk_write_pending++;
787 		xprt_wait_for_buffer_space(xprt);
788 	} else
789 		ret = -ENOTCONN;
790 
791 	spin_unlock(&xprt->transport_lock);
792 	return ret;
793 }
794 
795 static int xs_sock_nospace(struct rpc_rqst *req)
796 {
797 	struct sock_xprt *transport =
798 		container_of(req->rq_xprt, struct sock_xprt, xprt);
799 	struct sock *sk = transport->inet;
800 	int ret = -EAGAIN;
801 
802 	lock_sock(sk);
803 	if (!sock_writeable(sk))
804 		ret = xs_nospace(req, transport);
805 	release_sock(sk);
806 	return ret;
807 }
808 
809 static int xs_stream_nospace(struct rpc_rqst *req)
810 {
811 	struct sock_xprt *transport =
812 		container_of(req->rq_xprt, struct sock_xprt, xprt);
813 	struct sock *sk = transport->inet;
814 	int ret = -EAGAIN;
815 
816 	lock_sock(sk);
817 	if (!sk_stream_memory_free(sk))
818 		ret = xs_nospace(req, transport);
819 	release_sock(sk);
820 	return ret;
821 }
822 
823 static void
824 xs_stream_prepare_request(struct rpc_rqst *req)
825 {
826 	xdr_free_bvec(&req->rq_rcv_buf);
827 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
828 }
829 
830 /*
831  * Determine if the previous message in the stream was aborted before it
832  * could complete transmission.
833  */
834 static bool
835 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
836 {
837 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
838 }
839 
840 /*
841  * Return the stream record marker field for a record of length < 2^31-1
842  */
843 static rpc_fraghdr
844 xs_stream_record_marker(struct xdr_buf *xdr)
845 {
846 	if (!xdr->len)
847 		return 0;
848 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
849 }
850 
851 /**
852  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
853  * @req: pointer to RPC request
854  *
855  * Return values:
856  *        0:	The request has been sent
857  *   EAGAIN:	The socket was blocked, please call again later to
858  *		complete the request
859  * ENOTCONN:	Caller needs to invoke connect logic then call again
860  *    other:	Some other error occurred, the request was not sent
861  */
862 static int xs_local_send_request(struct rpc_rqst *req)
863 {
864 	struct rpc_xprt *xprt = req->rq_xprt;
865 	struct sock_xprt *transport =
866 				container_of(xprt, struct sock_xprt, xprt);
867 	struct xdr_buf *xdr = &req->rq_snd_buf;
868 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
869 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
870 	struct msghdr msg = {
871 		.msg_flags	= XS_SENDMSG_FLAGS,
872 	};
873 	unsigned int sent;
874 	int status;
875 
876 	/* Close the stream if the previous transmission was incomplete */
877 	if (xs_send_request_was_aborted(transport, req)) {
878 		xs_close(xprt);
879 		return -ENOTCONN;
880 	}
881 
882 	xs_pktdump("packet data:",
883 			req->rq_svec->iov_base, req->rq_svec->iov_len);
884 
885 	req->rq_xtime = ktime_get();
886 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
887 				   transport->xmit.offset, rm, &sent);
888 	dprintk("RPC:       %s(%u) = %d\n",
889 			__func__, xdr->len - transport->xmit.offset, status);
890 
891 	if (status == -EAGAIN && sock_writeable(transport->inet))
892 		status = -ENOBUFS;
893 
894 	if (likely(sent > 0) || status == 0) {
895 		transport->xmit.offset += sent;
896 		req->rq_bytes_sent = transport->xmit.offset;
897 		if (likely(req->rq_bytes_sent >= msglen)) {
898 			req->rq_xmit_bytes_sent += transport->xmit.offset;
899 			transport->xmit.offset = 0;
900 			return 0;
901 		}
902 		status = -EAGAIN;
903 	}
904 
905 	switch (status) {
906 	case -ENOBUFS:
907 		break;
908 	case -EAGAIN:
909 		status = xs_stream_nospace(req);
910 		break;
911 	default:
912 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
913 			-status);
914 		fallthrough;
915 	case -EPIPE:
916 		xs_close(xprt);
917 		status = -ENOTCONN;
918 	}
919 
920 	return status;
921 }
922 
923 /**
924  * xs_udp_send_request - write an RPC request to a UDP socket
925  * @req: pointer to RPC request
926  *
927  * Return values:
928  *        0:	The request has been sent
929  *   EAGAIN:	The socket was blocked, please call again later to
930  *		complete the request
931  * ENOTCONN:	Caller needs to invoke connect logic then call again
932  *    other:	Some other error occurred, the request was not sent
933  */
934 static int xs_udp_send_request(struct rpc_rqst *req)
935 {
936 	struct rpc_xprt *xprt = req->rq_xprt;
937 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
938 	struct xdr_buf *xdr = &req->rq_snd_buf;
939 	struct msghdr msg = {
940 		.msg_name	= xs_addr(xprt),
941 		.msg_namelen	= xprt->addrlen,
942 		.msg_flags	= XS_SENDMSG_FLAGS,
943 	};
944 	unsigned int sent;
945 	int status;
946 
947 	xs_pktdump("packet data:",
948 				req->rq_svec->iov_base,
949 				req->rq_svec->iov_len);
950 
951 	if (!xprt_bound(xprt))
952 		return -ENOTCONN;
953 
954 	if (!xprt_request_get_cong(xprt, req))
955 		return -EBADSLT;
956 
957 	req->rq_xtime = ktime_get();
958 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
959 
960 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
961 			xdr->len, status);
962 
963 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
964 	if (status == -EPERM)
965 		goto process_status;
966 
967 	if (status == -EAGAIN && sock_writeable(transport->inet))
968 		status = -ENOBUFS;
969 
970 	if (sent > 0 || status == 0) {
971 		req->rq_xmit_bytes_sent += sent;
972 		if (sent >= req->rq_slen)
973 			return 0;
974 		/* Still some bytes left; set up for a retry later. */
975 		status = -EAGAIN;
976 	}
977 
978 process_status:
979 	switch (status) {
980 	case -ENOTSOCK:
981 		status = -ENOTCONN;
982 		/* Should we call xs_close() here? */
983 		break;
984 	case -EAGAIN:
985 		status = xs_sock_nospace(req);
986 		break;
987 	case -ENETUNREACH:
988 	case -ENOBUFS:
989 	case -EPIPE:
990 	case -ECONNREFUSED:
991 	case -EPERM:
992 		/* When the server has died, an ICMP port unreachable message
993 		 * prompts ECONNREFUSED. */
994 		break;
995 	default:
996 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
997 			-status);
998 	}
999 
1000 	return status;
1001 }
1002 
1003 /**
1004  * xs_tcp_send_request - write an RPC request to a TCP socket
1005  * @req: pointer to RPC request
1006  *
1007  * Return values:
1008  *        0:	The request has been sent
1009  *   EAGAIN:	The socket was blocked, please call again later to
1010  *		complete the request
1011  * ENOTCONN:	Caller needs to invoke connect logic then call again
1012  *    other:	Some other error occurred, the request was not sent
1013  *
1014  * XXX: In the case of soft timeouts, should we eventually give up
1015  *	if sendmsg is not able to make progress?
1016  */
1017 static int xs_tcp_send_request(struct rpc_rqst *req)
1018 {
1019 	struct rpc_xprt *xprt = req->rq_xprt;
1020 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1021 	struct xdr_buf *xdr = &req->rq_snd_buf;
1022 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
1023 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1024 	struct msghdr msg = {
1025 		.msg_flags	= XS_SENDMSG_FLAGS,
1026 	};
1027 	bool vm_wait = false;
1028 	unsigned int sent;
1029 	int status;
1030 
1031 	/* Close the stream if the previous transmission was incomplete */
1032 	if (xs_send_request_was_aborted(transport, req)) {
1033 		if (transport->sock != NULL)
1034 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1035 		return -ENOTCONN;
1036 	}
1037 	if (!transport->inet)
1038 		return -ENOTCONN;
1039 
1040 	xs_pktdump("packet data:",
1041 				req->rq_svec->iov_base,
1042 				req->rq_svec->iov_len);
1043 
1044 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1045 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1046 
1047 	xs_set_srcport(transport, transport->sock);
1048 
1049 	/* Continue transmitting the packet/record. We must be careful
1050 	 * to cope with writespace callbacks arriving _after_ we have
1051 	 * called sendmsg(). */
1052 	req->rq_xtime = ktime_get();
1053 	tcp_sock_set_cork(transport->inet, true);
1054 	while (1) {
1055 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1056 					   transport->xmit.offset, rm, &sent);
1057 
1058 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1059 				xdr->len - transport->xmit.offset, status);
1060 
1061 		/* If we've sent the entire packet, immediately
1062 		 * reset the count of bytes sent. */
1063 		transport->xmit.offset += sent;
1064 		req->rq_bytes_sent = transport->xmit.offset;
1065 		if (likely(req->rq_bytes_sent >= msglen)) {
1066 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1067 			transport->xmit.offset = 0;
1068 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1069 				tcp_sock_set_cork(transport->inet, false);
1070 			return 0;
1071 		}
1072 
1073 		WARN_ON_ONCE(sent == 0 && status == 0);
1074 
1075 		if (status == -EAGAIN ) {
1076 			/*
1077 			 * Return EAGAIN if we're sure we're hitting the
1078 			 * socket send buffer limits.
1079 			 */
1080 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1081 				break;
1082 			/*
1083 			 * Did we hit a memory allocation failure?
1084 			 */
1085 			if (sent == 0) {
1086 				status = -ENOBUFS;
1087 				if (vm_wait)
1088 					break;
1089 				/* Retry, knowing now that we're below the
1090 				 * socket send buffer limit
1091 				 */
1092 				vm_wait = true;
1093 			}
1094 			continue;
1095 		}
1096 		if (status < 0)
1097 			break;
1098 		vm_wait = false;
1099 	}
1100 
1101 	switch (status) {
1102 	case -ENOTSOCK:
1103 		status = -ENOTCONN;
1104 		/* Should we call xs_close() here? */
1105 		break;
1106 	case -EAGAIN:
1107 		status = xs_stream_nospace(req);
1108 		break;
1109 	case -ECONNRESET:
1110 	case -ECONNREFUSED:
1111 	case -ENOTCONN:
1112 	case -EADDRINUSE:
1113 	case -ENOBUFS:
1114 	case -EPIPE:
1115 		break;
1116 	default:
1117 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1118 			-status);
1119 	}
1120 
1121 	return status;
1122 }
1123 
1124 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1125 {
1126 	transport->old_data_ready = sk->sk_data_ready;
1127 	transport->old_state_change = sk->sk_state_change;
1128 	transport->old_write_space = sk->sk_write_space;
1129 	transport->old_error_report = sk->sk_error_report;
1130 }
1131 
1132 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1133 {
1134 	sk->sk_data_ready = transport->old_data_ready;
1135 	sk->sk_state_change = transport->old_state_change;
1136 	sk->sk_write_space = transport->old_write_space;
1137 	sk->sk_error_report = transport->old_error_report;
1138 }
1139 
1140 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1141 {
1142 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1143 
1144 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1145 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1146 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1147 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1148 	clear_bit(XPRT_SOCK_NOSPACE, &transport->sock_state);
1149 }
1150 
1151 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1152 {
1153 	set_bit(nr, &transport->sock_state);
1154 	queue_work(xprtiod_workqueue, &transport->error_worker);
1155 }
1156 
1157 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1158 {
1159 	xprt->connect_cookie++;
1160 	smp_mb__before_atomic();
1161 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1162 	clear_bit(XPRT_CLOSING, &xprt->state);
1163 	xs_sock_reset_state_flags(xprt);
1164 	smp_mb__after_atomic();
1165 }
1166 
1167 /**
1168  * xs_error_report - callback to handle TCP socket state errors
1169  * @sk: socket
1170  *
1171  * Note: we don't call sock_error() since there may be a rpc_task
1172  * using the socket, and so we don't want to clear sk->sk_err.
1173  */
1174 static void xs_error_report(struct sock *sk)
1175 {
1176 	struct sock_xprt *transport;
1177 	struct rpc_xprt *xprt;
1178 
1179 	if (!(xprt = xprt_from_sock(sk)))
1180 		return;
1181 
1182 	transport = container_of(xprt, struct sock_xprt, xprt);
1183 	transport->xprt_err = -sk->sk_err;
1184 	if (transport->xprt_err == 0)
1185 		return;
1186 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1187 			xprt, -transport->xprt_err);
1188 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1189 
1190 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1191 	smp_mb__before_atomic();
1192 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1193 }
1194 
1195 static void xs_reset_transport(struct sock_xprt *transport)
1196 {
1197 	struct socket *sock = transport->sock;
1198 	struct sock *sk = transport->inet;
1199 	struct rpc_xprt *xprt = &transport->xprt;
1200 	struct file *filp = transport->file;
1201 
1202 	if (sk == NULL)
1203 		return;
1204 
1205 	if (atomic_read(&transport->xprt.swapper))
1206 		sk_clear_memalloc(sk);
1207 
1208 	kernel_sock_shutdown(sock, SHUT_RDWR);
1209 
1210 	mutex_lock(&transport->recv_mutex);
1211 	lock_sock(sk);
1212 	transport->inet = NULL;
1213 	transport->sock = NULL;
1214 	transport->file = NULL;
1215 
1216 	sk->sk_user_data = NULL;
1217 
1218 	xs_restore_old_callbacks(transport, sk);
1219 	xprt_clear_connected(xprt);
1220 	xs_sock_reset_connection_flags(xprt);
1221 	/* Reset stream record info */
1222 	xs_stream_reset_connect(transport);
1223 	release_sock(sk);
1224 	mutex_unlock(&transport->recv_mutex);
1225 
1226 	trace_rpc_socket_close(xprt, sock);
1227 	fput(filp);
1228 
1229 	xprt_disconnect_done(xprt);
1230 }
1231 
1232 /**
1233  * xs_close - close a socket
1234  * @xprt: transport
1235  *
1236  * This is used when all requests are complete; ie, no DRC state remains
1237  * on the server we want to save.
1238  *
1239  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1240  * xs_reset_transport() zeroing the socket from underneath a writer.
1241  */
1242 static void xs_close(struct rpc_xprt *xprt)
1243 {
1244 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1245 
1246 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1247 
1248 	xs_reset_transport(transport);
1249 	xprt->reestablish_timeout = 0;
1250 }
1251 
1252 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1253 {
1254 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1255 		xprt);
1256 	xprt_disconnect_done(xprt);
1257 }
1258 
1259 static void xs_xprt_free(struct rpc_xprt *xprt)
1260 {
1261 	xs_free_peer_addresses(xprt);
1262 	xprt_free(xprt);
1263 }
1264 
1265 /**
1266  * xs_destroy - prepare to shutdown a transport
1267  * @xprt: doomed transport
1268  *
1269  */
1270 static void xs_destroy(struct rpc_xprt *xprt)
1271 {
1272 	struct sock_xprt *transport = container_of(xprt,
1273 			struct sock_xprt, xprt);
1274 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1275 
1276 	cancel_delayed_work_sync(&transport->connect_worker);
1277 	xs_close(xprt);
1278 	cancel_work_sync(&transport->recv_worker);
1279 	cancel_work_sync(&transport->error_worker);
1280 	xs_xprt_free(xprt);
1281 	module_put(THIS_MODULE);
1282 }
1283 
1284 /**
1285  * xs_udp_data_read_skb - receive callback for UDP sockets
1286  * @xprt: transport
1287  * @sk: socket
1288  * @skb: skbuff
1289  *
1290  */
1291 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1292 		struct sock *sk,
1293 		struct sk_buff *skb)
1294 {
1295 	struct rpc_task *task;
1296 	struct rpc_rqst *rovr;
1297 	int repsize, copied;
1298 	u32 _xid;
1299 	__be32 *xp;
1300 
1301 	repsize = skb->len;
1302 	if (repsize < 4) {
1303 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1304 		return;
1305 	}
1306 
1307 	/* Copy the XID from the skb... */
1308 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1309 	if (xp == NULL)
1310 		return;
1311 
1312 	/* Look up and lock the request corresponding to the given XID */
1313 	spin_lock(&xprt->queue_lock);
1314 	rovr = xprt_lookup_rqst(xprt, *xp);
1315 	if (!rovr)
1316 		goto out_unlock;
1317 	xprt_pin_rqst(rovr);
1318 	xprt_update_rtt(rovr->rq_task);
1319 	spin_unlock(&xprt->queue_lock);
1320 	task = rovr->rq_task;
1321 
1322 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1323 		copied = repsize;
1324 
1325 	/* Suck it into the iovec, verify checksum if not done by hw. */
1326 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1327 		spin_lock(&xprt->queue_lock);
1328 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1329 		goto out_unpin;
1330 	}
1331 
1332 
1333 	spin_lock(&xprt->transport_lock);
1334 	xprt_adjust_cwnd(xprt, task, copied);
1335 	spin_unlock(&xprt->transport_lock);
1336 	spin_lock(&xprt->queue_lock);
1337 	xprt_complete_rqst(task, copied);
1338 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1339 out_unpin:
1340 	xprt_unpin_rqst(rovr);
1341  out_unlock:
1342 	spin_unlock(&xprt->queue_lock);
1343 }
1344 
1345 static void xs_udp_data_receive(struct sock_xprt *transport)
1346 {
1347 	struct sk_buff *skb;
1348 	struct sock *sk;
1349 	int err;
1350 
1351 	mutex_lock(&transport->recv_mutex);
1352 	sk = transport->inet;
1353 	if (sk == NULL)
1354 		goto out;
1355 	for (;;) {
1356 		skb = skb_recv_udp(sk, 0, 1, &err);
1357 		if (skb == NULL)
1358 			break;
1359 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1360 		consume_skb(skb);
1361 		cond_resched();
1362 	}
1363 	xs_poll_check_readable(transport);
1364 out:
1365 	mutex_unlock(&transport->recv_mutex);
1366 }
1367 
1368 static void xs_udp_data_receive_workfn(struct work_struct *work)
1369 {
1370 	struct sock_xprt *transport =
1371 		container_of(work, struct sock_xprt, recv_worker);
1372 	unsigned int pflags = memalloc_nofs_save();
1373 
1374 	xs_udp_data_receive(transport);
1375 	memalloc_nofs_restore(pflags);
1376 }
1377 
1378 /**
1379  * xs_data_ready - "data ready" callback for UDP sockets
1380  * @sk: socket with data to read
1381  *
1382  */
1383 static void xs_data_ready(struct sock *sk)
1384 {
1385 	struct rpc_xprt *xprt;
1386 
1387 	dprintk("RPC:       xs_data_ready...\n");
1388 	xprt = xprt_from_sock(sk);
1389 	if (xprt != NULL) {
1390 		struct sock_xprt *transport = container_of(xprt,
1391 				struct sock_xprt, xprt);
1392 		transport->old_data_ready(sk);
1393 		/* Any data means we had a useful conversation, so
1394 		 * then we don't need to delay the next reconnect
1395 		 */
1396 		if (xprt->reestablish_timeout)
1397 			xprt->reestablish_timeout = 0;
1398 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1399 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1400 	}
1401 }
1402 
1403 /*
1404  * Helper function to force a TCP close if the server is sending
1405  * junk and/or it has put us in CLOSE_WAIT
1406  */
1407 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1408 {
1409 	xprt_force_disconnect(xprt);
1410 }
1411 
1412 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1413 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1414 {
1415 	return PAGE_SIZE;
1416 }
1417 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1418 
1419 /**
1420  * xs_tcp_state_change - callback to handle TCP socket state changes
1421  * @sk: socket whose state has changed
1422  *
1423  */
1424 static void xs_tcp_state_change(struct sock *sk)
1425 {
1426 	struct rpc_xprt *xprt;
1427 	struct sock_xprt *transport;
1428 
1429 	if (!(xprt = xprt_from_sock(sk)))
1430 		return;
1431 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1432 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1433 			sk->sk_state, xprt_connected(xprt),
1434 			sock_flag(sk, SOCK_DEAD),
1435 			sock_flag(sk, SOCK_ZAPPED),
1436 			sk->sk_shutdown);
1437 
1438 	transport = container_of(xprt, struct sock_xprt, xprt);
1439 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1440 	switch (sk->sk_state) {
1441 	case TCP_ESTABLISHED:
1442 		if (!xprt_test_and_set_connected(xprt)) {
1443 			xprt->connect_cookie++;
1444 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1445 			xprt_clear_connecting(xprt);
1446 
1447 			xprt->stat.connect_count++;
1448 			xprt->stat.connect_time += (long)jiffies -
1449 						   xprt->stat.connect_start;
1450 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1451 		}
1452 		break;
1453 	case TCP_FIN_WAIT1:
1454 		/* The client initiated a shutdown of the socket */
1455 		xprt->connect_cookie++;
1456 		xprt->reestablish_timeout = 0;
1457 		set_bit(XPRT_CLOSING, &xprt->state);
1458 		smp_mb__before_atomic();
1459 		clear_bit(XPRT_CONNECTED, &xprt->state);
1460 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1461 		smp_mb__after_atomic();
1462 		break;
1463 	case TCP_CLOSE_WAIT:
1464 		/* The server initiated a shutdown of the socket */
1465 		xprt->connect_cookie++;
1466 		clear_bit(XPRT_CONNECTED, &xprt->state);
1467 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1468 		fallthrough;
1469 	case TCP_CLOSING:
1470 		/*
1471 		 * If the server closed down the connection, make sure that
1472 		 * we back off before reconnecting
1473 		 */
1474 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1475 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1476 		break;
1477 	case TCP_LAST_ACK:
1478 		set_bit(XPRT_CLOSING, &xprt->state);
1479 		smp_mb__before_atomic();
1480 		clear_bit(XPRT_CONNECTED, &xprt->state);
1481 		smp_mb__after_atomic();
1482 		break;
1483 	case TCP_CLOSE:
1484 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1485 					&transport->sock_state))
1486 			xprt_clear_connecting(xprt);
1487 		clear_bit(XPRT_CLOSING, &xprt->state);
1488 		/* Trigger the socket release */
1489 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1490 	}
1491 }
1492 
1493 static void xs_write_space(struct sock *sk)
1494 {
1495 	struct sock_xprt *transport;
1496 	struct rpc_xprt *xprt;
1497 
1498 	if (!sk->sk_socket)
1499 		return;
1500 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1501 
1502 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1503 		return;
1504 	transport = container_of(xprt, struct sock_xprt, xprt);
1505 	if (!test_and_clear_bit(XPRT_SOCK_NOSPACE, &transport->sock_state))
1506 		return;
1507 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1508 	sk->sk_write_pending--;
1509 }
1510 
1511 /**
1512  * xs_udp_write_space - callback invoked when socket buffer space
1513  *                             becomes available
1514  * @sk: socket whose state has changed
1515  *
1516  * Called when more output buffer space is available for this socket.
1517  * We try not to wake our writers until they can make "significant"
1518  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1519  * with a bunch of small requests.
1520  */
1521 static void xs_udp_write_space(struct sock *sk)
1522 {
1523 	/* from net/core/sock.c:sock_def_write_space */
1524 	if (sock_writeable(sk))
1525 		xs_write_space(sk);
1526 }
1527 
1528 /**
1529  * xs_tcp_write_space - callback invoked when socket buffer space
1530  *                             becomes available
1531  * @sk: socket whose state has changed
1532  *
1533  * Called when more output buffer space is available for this socket.
1534  * We try not to wake our writers until they can make "significant"
1535  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1536  * with a bunch of small requests.
1537  */
1538 static void xs_tcp_write_space(struct sock *sk)
1539 {
1540 	/* from net/core/stream.c:sk_stream_write_space */
1541 	if (sk_stream_is_writeable(sk))
1542 		xs_write_space(sk);
1543 }
1544 
1545 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1546 {
1547 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1548 	struct sock *sk = transport->inet;
1549 
1550 	if (transport->rcvsize) {
1551 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1552 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1553 	}
1554 	if (transport->sndsize) {
1555 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1556 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1557 		sk->sk_write_space(sk);
1558 	}
1559 }
1560 
1561 /**
1562  * xs_udp_set_buffer_size - set send and receive limits
1563  * @xprt: generic transport
1564  * @sndsize: requested size of send buffer, in bytes
1565  * @rcvsize: requested size of receive buffer, in bytes
1566  *
1567  * Set socket send and receive buffer size limits.
1568  */
1569 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1570 {
1571 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1572 
1573 	transport->sndsize = 0;
1574 	if (sndsize)
1575 		transport->sndsize = sndsize + 1024;
1576 	transport->rcvsize = 0;
1577 	if (rcvsize)
1578 		transport->rcvsize = rcvsize + 1024;
1579 
1580 	xs_udp_do_set_buffer_size(xprt);
1581 }
1582 
1583 /**
1584  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1585  * @xprt: controlling transport
1586  * @task: task that timed out
1587  *
1588  * Adjust the congestion window after a retransmit timeout has occurred.
1589  */
1590 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1591 {
1592 	spin_lock(&xprt->transport_lock);
1593 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1594 	spin_unlock(&xprt->transport_lock);
1595 }
1596 
1597 static int xs_get_random_port(void)
1598 {
1599 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1600 	unsigned short range;
1601 	unsigned short rand;
1602 
1603 	if (max < min)
1604 		return -EADDRINUSE;
1605 	range = max - min + 1;
1606 	rand = (unsigned short) prandom_u32() % range;
1607 	return rand + min;
1608 }
1609 
1610 static unsigned short xs_sock_getport(struct socket *sock)
1611 {
1612 	struct sockaddr_storage buf;
1613 	unsigned short port = 0;
1614 
1615 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1616 		goto out;
1617 	switch (buf.ss_family) {
1618 	case AF_INET6:
1619 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1620 		break;
1621 	case AF_INET:
1622 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1623 	}
1624 out:
1625 	return port;
1626 }
1627 
1628 /**
1629  * xs_set_port - reset the port number in the remote endpoint address
1630  * @xprt: generic transport
1631  * @port: new port number
1632  *
1633  */
1634 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1635 {
1636 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1637 
1638 	rpc_set_port(xs_addr(xprt), port);
1639 	xs_update_peer_port(xprt);
1640 }
1641 
1642 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1643 {
1644 	if (transport->srcport == 0 && transport->xprt.reuseport)
1645 		transport->srcport = xs_sock_getport(sock);
1646 }
1647 
1648 static int xs_get_srcport(struct sock_xprt *transport)
1649 {
1650 	int port = transport->srcport;
1651 
1652 	if (port == 0 && transport->xprt.resvport)
1653 		port = xs_get_random_port();
1654 	return port;
1655 }
1656 
1657 unsigned short get_srcport(struct rpc_xprt *xprt)
1658 {
1659 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1660 	unsigned short ret = 0;
1661 	mutex_lock(&sock->recv_mutex);
1662 	if (sock->sock)
1663 		ret = xs_sock_getport(sock->sock);
1664 	mutex_unlock(&sock->recv_mutex);
1665 	return ret;
1666 }
1667 EXPORT_SYMBOL(get_srcport);
1668 
1669 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1670 {
1671 	if (transport->srcport != 0)
1672 		transport->srcport = 0;
1673 	if (!transport->xprt.resvport)
1674 		return 0;
1675 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1676 		return xprt_max_resvport;
1677 	return --port;
1678 }
1679 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1680 {
1681 	struct sockaddr_storage myaddr;
1682 	int err, nloop = 0;
1683 	int port = xs_get_srcport(transport);
1684 	unsigned short last;
1685 
1686 	/*
1687 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1688 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1689 	 * port selection happen implicitly when the socket is used
1690 	 * (for example at connect time).
1691 	 *
1692 	 * This ensures that we can continue to establish TCP
1693 	 * connections even when all local ephemeral ports are already
1694 	 * a part of some TCP connection.  This makes no difference
1695 	 * for UDP sockets, but also doesn't harm them.
1696 	 *
1697 	 * If we're asking for any reserved port (i.e. port == 0 &&
1698 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1699 	 * ensure that port is non-zero and we will bind as needed.
1700 	 */
1701 	if (port <= 0)
1702 		return port;
1703 
1704 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1705 	do {
1706 		rpc_set_port((struct sockaddr *)&myaddr, port);
1707 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1708 				transport->xprt.addrlen);
1709 		if (err == 0) {
1710 			if (transport->xprt.reuseport)
1711 				transport->srcport = port;
1712 			break;
1713 		}
1714 		last = port;
1715 		port = xs_next_srcport(transport, port);
1716 		if (port > last)
1717 			nloop++;
1718 	} while (err == -EADDRINUSE && nloop != 2);
1719 
1720 	if (myaddr.ss_family == AF_INET)
1721 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1722 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1723 				port, err ? "failed" : "ok", err);
1724 	else
1725 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1726 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1727 				port, err ? "failed" : "ok", err);
1728 	return err;
1729 }
1730 
1731 /*
1732  * We don't support autobind on AF_LOCAL sockets
1733  */
1734 static void xs_local_rpcbind(struct rpc_task *task)
1735 {
1736 	xprt_set_bound(task->tk_xprt);
1737 }
1738 
1739 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1740 {
1741 }
1742 
1743 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1744 static struct lock_class_key xs_key[3];
1745 static struct lock_class_key xs_slock_key[3];
1746 
1747 static inline void xs_reclassify_socketu(struct socket *sock)
1748 {
1749 	struct sock *sk = sock->sk;
1750 
1751 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1752 		&xs_slock_key[0], "sk_lock-AF_LOCAL-RPC", &xs_key[0]);
1753 }
1754 
1755 static inline void xs_reclassify_socket4(struct socket *sock)
1756 {
1757 	struct sock *sk = sock->sk;
1758 
1759 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1760 		&xs_slock_key[1], "sk_lock-AF_INET-RPC", &xs_key[1]);
1761 }
1762 
1763 static inline void xs_reclassify_socket6(struct socket *sock)
1764 {
1765 	struct sock *sk = sock->sk;
1766 
1767 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1768 		&xs_slock_key[2], "sk_lock-AF_INET6-RPC", &xs_key[2]);
1769 }
1770 
1771 static inline void xs_reclassify_socket(int family, struct socket *sock)
1772 {
1773 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1774 		return;
1775 
1776 	switch (family) {
1777 	case AF_LOCAL:
1778 		xs_reclassify_socketu(sock);
1779 		break;
1780 	case AF_INET:
1781 		xs_reclassify_socket4(sock);
1782 		break;
1783 	case AF_INET6:
1784 		xs_reclassify_socket6(sock);
1785 		break;
1786 	}
1787 }
1788 #else
1789 static inline void xs_reclassify_socket(int family, struct socket *sock)
1790 {
1791 }
1792 #endif
1793 
1794 static void xs_dummy_setup_socket(struct work_struct *work)
1795 {
1796 }
1797 
1798 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1799 		struct sock_xprt *transport, int family, int type,
1800 		int protocol, bool reuseport)
1801 {
1802 	struct file *filp;
1803 	struct socket *sock;
1804 	int err;
1805 
1806 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1807 	if (err < 0) {
1808 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1809 				protocol, -err);
1810 		goto out;
1811 	}
1812 	xs_reclassify_socket(family, sock);
1813 
1814 	if (reuseport)
1815 		sock_set_reuseport(sock->sk);
1816 
1817 	err = xs_bind(transport, sock);
1818 	if (err) {
1819 		sock_release(sock);
1820 		goto out;
1821 	}
1822 
1823 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1824 	if (IS_ERR(filp))
1825 		return ERR_CAST(filp);
1826 	transport->file = filp;
1827 
1828 	return sock;
1829 out:
1830 	return ERR_PTR(err);
1831 }
1832 
1833 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1834 				      struct socket *sock)
1835 {
1836 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1837 									xprt);
1838 
1839 	if (!transport->inet) {
1840 		struct sock *sk = sock->sk;
1841 
1842 		lock_sock(sk);
1843 
1844 		xs_save_old_callbacks(transport, sk);
1845 
1846 		sk->sk_user_data = xprt;
1847 		sk->sk_data_ready = xs_data_ready;
1848 		sk->sk_write_space = xs_udp_write_space;
1849 		sk->sk_error_report = xs_error_report;
1850 
1851 		xprt_clear_connected(xprt);
1852 
1853 		/* Reset to new socket */
1854 		transport->sock = sock;
1855 		transport->inet = sk;
1856 
1857 		release_sock(sk);
1858 	}
1859 
1860 	xs_stream_start_connect(transport);
1861 
1862 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1863 }
1864 
1865 /**
1866  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1867  * @transport: socket transport to connect
1868  */
1869 static int xs_local_setup_socket(struct sock_xprt *transport)
1870 {
1871 	struct rpc_xprt *xprt = &transport->xprt;
1872 	struct file *filp;
1873 	struct socket *sock;
1874 	int status;
1875 
1876 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1877 					SOCK_STREAM, 0, &sock, 1);
1878 	if (status < 0) {
1879 		dprintk("RPC:       can't create AF_LOCAL "
1880 			"transport socket (%d).\n", -status);
1881 		goto out;
1882 	}
1883 	xs_reclassify_socket(AF_LOCAL, sock);
1884 
1885 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1886 	if (IS_ERR(filp)) {
1887 		status = PTR_ERR(filp);
1888 		goto out;
1889 	}
1890 	transport->file = filp;
1891 
1892 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1893 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1894 
1895 	status = xs_local_finish_connecting(xprt, sock);
1896 	trace_rpc_socket_connect(xprt, sock, status);
1897 	switch (status) {
1898 	case 0:
1899 		dprintk("RPC:       xprt %p connected to %s\n",
1900 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1901 		xprt->stat.connect_count++;
1902 		xprt->stat.connect_time += (long)jiffies -
1903 					   xprt->stat.connect_start;
1904 		xprt_set_connected(xprt);
1905 		break;
1906 	case -ENOBUFS:
1907 		break;
1908 	case -ENOENT:
1909 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1910 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1911 		break;
1912 	case -ECONNREFUSED:
1913 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1914 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1915 		break;
1916 	default:
1917 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1918 				__func__, -status,
1919 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1920 	}
1921 
1922 out:
1923 	xprt_clear_connecting(xprt);
1924 	xprt_wake_pending_tasks(xprt, status);
1925 	return status;
1926 }
1927 
1928 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1929 {
1930 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1931 	int ret;
1932 
1933 	if (RPC_IS_ASYNC(task)) {
1934 		/*
1935 		 * We want the AF_LOCAL connect to be resolved in the
1936 		 * filesystem namespace of the process making the rpc
1937 		 * call.  Thus we connect synchronously.
1938 		 *
1939 		 * If we want to support asynchronous AF_LOCAL calls,
1940 		 * we'll need to figure out how to pass a namespace to
1941 		 * connect.
1942 		 */
1943 		task->tk_rpc_status = -ENOTCONN;
1944 		rpc_exit(task, -ENOTCONN);
1945 		return;
1946 	}
1947 	ret = xs_local_setup_socket(transport);
1948 	if (ret && !RPC_IS_SOFTCONN(task))
1949 		msleep_interruptible(15000);
1950 }
1951 
1952 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1953 /*
1954  * Note that this should be called with XPRT_LOCKED held, or recv_mutex
1955  * held, or when we otherwise know that we have exclusive access to the
1956  * socket, to guard against races with xs_reset_transport.
1957  */
1958 static void xs_set_memalloc(struct rpc_xprt *xprt)
1959 {
1960 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1961 			xprt);
1962 
1963 	/*
1964 	 * If there's no sock, then we have nothing to set. The
1965 	 * reconnecting process will get it for us.
1966 	 */
1967 	if (!transport->inet)
1968 		return;
1969 	if (atomic_read(&xprt->swapper))
1970 		sk_set_memalloc(transport->inet);
1971 }
1972 
1973 /**
1974  * xs_enable_swap - Tag this transport as being used for swap.
1975  * @xprt: transport to tag
1976  *
1977  * Take a reference to this transport on behalf of the rpc_clnt, and
1978  * optionally mark it for swapping if it wasn't already.
1979  */
1980 static int
1981 xs_enable_swap(struct rpc_xprt *xprt)
1982 {
1983 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1984 
1985 	mutex_lock(&xs->recv_mutex);
1986 	if (atomic_inc_return(&xprt->swapper) == 1 &&
1987 	    xs->inet)
1988 		sk_set_memalloc(xs->inet);
1989 	mutex_unlock(&xs->recv_mutex);
1990 	return 0;
1991 }
1992 
1993 /**
1994  * xs_disable_swap - Untag this transport as being used for swap.
1995  * @xprt: transport to tag
1996  *
1997  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1998  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1999  */
2000 static void
2001 xs_disable_swap(struct rpc_xprt *xprt)
2002 {
2003 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2004 
2005 	mutex_lock(&xs->recv_mutex);
2006 	if (atomic_dec_and_test(&xprt->swapper) &&
2007 	    xs->inet)
2008 		sk_clear_memalloc(xs->inet);
2009 	mutex_unlock(&xs->recv_mutex);
2010 }
2011 #else
2012 static void xs_set_memalloc(struct rpc_xprt *xprt)
2013 {
2014 }
2015 
2016 static int
2017 xs_enable_swap(struct rpc_xprt *xprt)
2018 {
2019 	return -EINVAL;
2020 }
2021 
2022 static void
2023 xs_disable_swap(struct rpc_xprt *xprt)
2024 {
2025 }
2026 #endif
2027 
2028 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2029 {
2030 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2031 
2032 	if (!transport->inet) {
2033 		struct sock *sk = sock->sk;
2034 
2035 		lock_sock(sk);
2036 
2037 		xs_save_old_callbacks(transport, sk);
2038 
2039 		sk->sk_user_data = xprt;
2040 		sk->sk_data_ready = xs_data_ready;
2041 		sk->sk_write_space = xs_udp_write_space;
2042 
2043 		xprt_set_connected(xprt);
2044 
2045 		/* Reset to new socket */
2046 		transport->sock = sock;
2047 		transport->inet = sk;
2048 
2049 		xs_set_memalloc(xprt);
2050 
2051 		release_sock(sk);
2052 	}
2053 	xs_udp_do_set_buffer_size(xprt);
2054 
2055 	xprt->stat.connect_start = jiffies;
2056 }
2057 
2058 static void xs_udp_setup_socket(struct work_struct *work)
2059 {
2060 	struct sock_xprt *transport =
2061 		container_of(work, struct sock_xprt, connect_worker.work);
2062 	struct rpc_xprt *xprt = &transport->xprt;
2063 	struct socket *sock;
2064 	int status = -EIO;
2065 	unsigned int pflags = current->flags;
2066 
2067 	if (atomic_read(&xprt->swapper))
2068 		current->flags |= PF_MEMALLOC;
2069 	sock = xs_create_sock(xprt, transport,
2070 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2071 			IPPROTO_UDP, false);
2072 	if (IS_ERR(sock))
2073 		goto out;
2074 
2075 	dprintk("RPC:       worker connecting xprt %p via %s to "
2076 				"%s (port %s)\n", xprt,
2077 			xprt->address_strings[RPC_DISPLAY_PROTO],
2078 			xprt->address_strings[RPC_DISPLAY_ADDR],
2079 			xprt->address_strings[RPC_DISPLAY_PORT]);
2080 
2081 	xs_udp_finish_connecting(xprt, sock);
2082 	trace_rpc_socket_connect(xprt, sock, 0);
2083 	status = 0;
2084 out:
2085 	xprt_clear_connecting(xprt);
2086 	xprt_unlock_connect(xprt, transport);
2087 	xprt_wake_pending_tasks(xprt, status);
2088 	current_restore_flags(pflags, PF_MEMALLOC);
2089 }
2090 
2091 /**
2092  * xs_tcp_shutdown - gracefully shut down a TCP socket
2093  * @xprt: transport
2094  *
2095  * Initiates a graceful shutdown of the TCP socket by calling the
2096  * equivalent of shutdown(SHUT_RDWR);
2097  */
2098 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2099 {
2100 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2101 	struct socket *sock = transport->sock;
2102 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2103 
2104 	if (sock == NULL)
2105 		return;
2106 	if (!xprt->reuseport) {
2107 		xs_close(xprt);
2108 		return;
2109 	}
2110 	switch (skst) {
2111 	case TCP_FIN_WAIT1:
2112 	case TCP_FIN_WAIT2:
2113 		break;
2114 	case TCP_ESTABLISHED:
2115 	case TCP_CLOSE_WAIT:
2116 		kernel_sock_shutdown(sock, SHUT_RDWR);
2117 		trace_rpc_socket_shutdown(xprt, sock);
2118 		break;
2119 	default:
2120 		xs_reset_transport(transport);
2121 	}
2122 }
2123 
2124 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2125 		struct socket *sock)
2126 {
2127 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2128 	unsigned int keepidle;
2129 	unsigned int keepcnt;
2130 	unsigned int timeo;
2131 
2132 	spin_lock(&xprt->transport_lock);
2133 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2134 	keepcnt = xprt->timeout->to_retries + 1;
2135 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2136 		(xprt->timeout->to_retries + 1);
2137 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2138 	spin_unlock(&xprt->transport_lock);
2139 
2140 	/* TCP Keepalive options */
2141 	sock_set_keepalive(sock->sk);
2142 	tcp_sock_set_keepidle(sock->sk, keepidle);
2143 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2144 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2145 
2146 	/* TCP user timeout (see RFC5482) */
2147 	tcp_sock_set_user_timeout(sock->sk, timeo);
2148 }
2149 
2150 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2151 		unsigned long connect_timeout,
2152 		unsigned long reconnect_timeout)
2153 {
2154 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2155 	struct rpc_timeout to;
2156 	unsigned long initval;
2157 
2158 	spin_lock(&xprt->transport_lock);
2159 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2160 		xprt->max_reconnect_timeout = reconnect_timeout;
2161 	if (connect_timeout < xprt->connect_timeout) {
2162 		memcpy(&to, xprt->timeout, sizeof(to));
2163 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2164 		/* Arbitrary lower limit */
2165 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2166 			initval = XS_TCP_INIT_REEST_TO << 1;
2167 		to.to_initval = initval;
2168 		to.to_maxval = initval;
2169 		memcpy(&transport->tcp_timeout, &to,
2170 				sizeof(transport->tcp_timeout));
2171 		xprt->timeout = &transport->tcp_timeout;
2172 		xprt->connect_timeout = connect_timeout;
2173 	}
2174 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2175 	spin_unlock(&xprt->transport_lock);
2176 }
2177 
2178 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2179 {
2180 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2181 
2182 	if (!transport->inet) {
2183 		struct sock *sk = sock->sk;
2184 
2185 		/* Avoid temporary address, they are bad for long-lived
2186 		 * connections such as NFS mounts.
2187 		 * RFC4941, section 3.6 suggests that:
2188 		 *    Individual applications, which have specific
2189 		 *    knowledge about the normal duration of connections,
2190 		 *    MAY override this as appropriate.
2191 		 */
2192 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2193 			ip6_sock_set_addr_preferences(sk,
2194 				IPV6_PREFER_SRC_PUBLIC);
2195 		}
2196 
2197 		xs_tcp_set_socket_timeouts(xprt, sock);
2198 		tcp_sock_set_nodelay(sk);
2199 
2200 		lock_sock(sk);
2201 
2202 		xs_save_old_callbacks(transport, sk);
2203 
2204 		sk->sk_user_data = xprt;
2205 		sk->sk_data_ready = xs_data_ready;
2206 		sk->sk_state_change = xs_tcp_state_change;
2207 		sk->sk_write_space = xs_tcp_write_space;
2208 		sk->sk_error_report = xs_error_report;
2209 
2210 		/* socket options */
2211 		sock_reset_flag(sk, SOCK_LINGER);
2212 
2213 		xprt_clear_connected(xprt);
2214 
2215 		/* Reset to new socket */
2216 		transport->sock = sock;
2217 		transport->inet = sk;
2218 
2219 		release_sock(sk);
2220 	}
2221 
2222 	if (!xprt_bound(xprt))
2223 		return -ENOTCONN;
2224 
2225 	xs_set_memalloc(xprt);
2226 
2227 	xs_stream_start_connect(transport);
2228 
2229 	/* Tell the socket layer to start connecting... */
2230 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2231 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2232 }
2233 
2234 /**
2235  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2236  * @work: queued work item
2237  *
2238  * Invoked by a work queue tasklet.
2239  */
2240 static void xs_tcp_setup_socket(struct work_struct *work)
2241 {
2242 	struct sock_xprt *transport =
2243 		container_of(work, struct sock_xprt, connect_worker.work);
2244 	struct socket *sock = transport->sock;
2245 	struct rpc_xprt *xprt = &transport->xprt;
2246 	int status;
2247 	unsigned int pflags = current->flags;
2248 
2249 	if (atomic_read(&xprt->swapper))
2250 		current->flags |= PF_MEMALLOC;
2251 
2252 	if (xprt_connected(xprt))
2253 		goto out;
2254 	if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,
2255 			       &transport->sock_state) ||
2256 	    !sock) {
2257 		xs_reset_transport(transport);
2258 		sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
2259 				      SOCK_STREAM, IPPROTO_TCP, true);
2260 		if (IS_ERR(sock)) {
2261 			xprt_wake_pending_tasks(xprt, PTR_ERR(sock));
2262 			goto out;
2263 		}
2264 	}
2265 
2266 	dprintk("RPC:       worker connecting xprt %p via %s to "
2267 				"%s (port %s)\n", xprt,
2268 			xprt->address_strings[RPC_DISPLAY_PROTO],
2269 			xprt->address_strings[RPC_DISPLAY_ADDR],
2270 			xprt->address_strings[RPC_DISPLAY_PORT]);
2271 
2272 	status = xs_tcp_finish_connecting(xprt, sock);
2273 	trace_rpc_socket_connect(xprt, sock, status);
2274 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2275 			xprt, -status, xprt_connected(xprt),
2276 			sock->sk->sk_state);
2277 	switch (status) {
2278 	case 0:
2279 	case -EINPROGRESS:
2280 		/* SYN_SENT! */
2281 		set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
2282 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2283 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2284 		fallthrough;
2285 	case -EALREADY:
2286 		goto out_unlock;
2287 	case -EADDRNOTAVAIL:
2288 		/* Source port number is unavailable. Try a new one! */
2289 		transport->srcport = 0;
2290 		status = -EAGAIN;
2291 		break;
2292 	case -EINVAL:
2293 		/* Happens, for instance, if the user specified a link
2294 		 * local IPv6 address without a scope-id.
2295 		 */
2296 	case -ECONNREFUSED:
2297 	case -ECONNRESET:
2298 	case -ENETDOWN:
2299 	case -ENETUNREACH:
2300 	case -EHOSTUNREACH:
2301 	case -EADDRINUSE:
2302 	case -ENOBUFS:
2303 		break;
2304 	default:
2305 		printk("%s: connect returned unhandled error %d\n",
2306 			__func__, status);
2307 		status = -EAGAIN;
2308 	}
2309 
2310 	/* xs_tcp_force_close() wakes tasks with a fixed error code.
2311 	 * We need to wake them first to ensure the correct error code.
2312 	 */
2313 	xprt_wake_pending_tasks(xprt, status);
2314 	xs_tcp_force_close(xprt);
2315 out:
2316 	xprt_clear_connecting(xprt);
2317 out_unlock:
2318 	xprt_unlock_connect(xprt, transport);
2319 	current_restore_flags(pflags, PF_MEMALLOC);
2320 }
2321 
2322 /**
2323  * xs_connect - connect a socket to a remote endpoint
2324  * @xprt: pointer to transport structure
2325  * @task: address of RPC task that manages state of connect request
2326  *
2327  * TCP: If the remote end dropped the connection, delay reconnecting.
2328  *
2329  * UDP socket connects are synchronous, but we use a work queue anyway
2330  * to guarantee that even unprivileged user processes can set up a
2331  * socket on a privileged port.
2332  *
2333  * If a UDP socket connect fails, the delay behavior here prevents
2334  * retry floods (hard mounts).
2335  */
2336 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2337 {
2338 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2339 	unsigned long delay = 0;
2340 
2341 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2342 
2343 	if (transport->sock != NULL) {
2344 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2345 			"seconds\n", xprt, xprt->reestablish_timeout / HZ);
2346 
2347 		delay = xprt_reconnect_delay(xprt);
2348 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2349 
2350 	} else
2351 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2352 
2353 	queue_delayed_work(xprtiod_workqueue,
2354 			&transport->connect_worker,
2355 			delay);
2356 }
2357 
2358 static void xs_wake_disconnect(struct sock_xprt *transport)
2359 {
2360 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2361 		xs_tcp_force_close(&transport->xprt);
2362 }
2363 
2364 static void xs_wake_write(struct sock_xprt *transport)
2365 {
2366 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2367 		xprt_write_space(&transport->xprt);
2368 }
2369 
2370 static void xs_wake_error(struct sock_xprt *transport)
2371 {
2372 	int sockerr;
2373 
2374 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2375 		return;
2376 	mutex_lock(&transport->recv_mutex);
2377 	if (transport->sock == NULL)
2378 		goto out;
2379 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2380 		goto out;
2381 	sockerr = xchg(&transport->xprt_err, 0);
2382 	if (sockerr < 0)
2383 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2384 out:
2385 	mutex_unlock(&transport->recv_mutex);
2386 }
2387 
2388 static void xs_wake_pending(struct sock_xprt *transport)
2389 {
2390 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2391 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2392 }
2393 
2394 static void xs_error_handle(struct work_struct *work)
2395 {
2396 	struct sock_xprt *transport = container_of(work,
2397 			struct sock_xprt, error_worker);
2398 
2399 	xs_wake_disconnect(transport);
2400 	xs_wake_write(transport);
2401 	xs_wake_error(transport);
2402 	xs_wake_pending(transport);
2403 }
2404 
2405 /**
2406  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2407  * @xprt: rpc_xprt struct containing statistics
2408  * @seq: output file
2409  *
2410  */
2411 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2412 {
2413 	long idle_time = 0;
2414 
2415 	if (xprt_connected(xprt))
2416 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2417 
2418 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2419 			"%llu %llu %lu %llu %llu\n",
2420 			xprt->stat.bind_count,
2421 			xprt->stat.connect_count,
2422 			xprt->stat.connect_time / HZ,
2423 			idle_time,
2424 			xprt->stat.sends,
2425 			xprt->stat.recvs,
2426 			xprt->stat.bad_xids,
2427 			xprt->stat.req_u,
2428 			xprt->stat.bklog_u,
2429 			xprt->stat.max_slots,
2430 			xprt->stat.sending_u,
2431 			xprt->stat.pending_u);
2432 }
2433 
2434 /**
2435  * xs_udp_print_stats - display UDP socket-specific stats
2436  * @xprt: rpc_xprt struct containing statistics
2437  * @seq: output file
2438  *
2439  */
2440 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2441 {
2442 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2443 
2444 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2445 			"%lu %llu %llu\n",
2446 			transport->srcport,
2447 			xprt->stat.bind_count,
2448 			xprt->stat.sends,
2449 			xprt->stat.recvs,
2450 			xprt->stat.bad_xids,
2451 			xprt->stat.req_u,
2452 			xprt->stat.bklog_u,
2453 			xprt->stat.max_slots,
2454 			xprt->stat.sending_u,
2455 			xprt->stat.pending_u);
2456 }
2457 
2458 /**
2459  * xs_tcp_print_stats - display TCP socket-specific stats
2460  * @xprt: rpc_xprt struct containing statistics
2461  * @seq: output file
2462  *
2463  */
2464 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2465 {
2466 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2467 	long idle_time = 0;
2468 
2469 	if (xprt_connected(xprt))
2470 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2471 
2472 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2473 			"%llu %llu %lu %llu %llu\n",
2474 			transport->srcport,
2475 			xprt->stat.bind_count,
2476 			xprt->stat.connect_count,
2477 			xprt->stat.connect_time / HZ,
2478 			idle_time,
2479 			xprt->stat.sends,
2480 			xprt->stat.recvs,
2481 			xprt->stat.bad_xids,
2482 			xprt->stat.req_u,
2483 			xprt->stat.bklog_u,
2484 			xprt->stat.max_slots,
2485 			xprt->stat.sending_u,
2486 			xprt->stat.pending_u);
2487 }
2488 
2489 /*
2490  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2491  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2492  * to use the server side send routines.
2493  */
2494 static int bc_malloc(struct rpc_task *task)
2495 {
2496 	struct rpc_rqst *rqst = task->tk_rqstp;
2497 	size_t size = rqst->rq_callsize;
2498 	struct page *page;
2499 	struct rpc_buffer *buf;
2500 
2501 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2502 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2503 			  size);
2504 		return -EINVAL;
2505 	}
2506 
2507 	page = alloc_page(GFP_KERNEL);
2508 	if (!page)
2509 		return -ENOMEM;
2510 
2511 	buf = page_address(page);
2512 	buf->len = PAGE_SIZE;
2513 
2514 	rqst->rq_buffer = buf->data;
2515 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2516 	return 0;
2517 }
2518 
2519 /*
2520  * Free the space allocated in the bc_alloc routine
2521  */
2522 static void bc_free(struct rpc_task *task)
2523 {
2524 	void *buffer = task->tk_rqstp->rq_buffer;
2525 	struct rpc_buffer *buf;
2526 
2527 	buf = container_of(buffer, struct rpc_buffer, data);
2528 	free_page((unsigned long)buf);
2529 }
2530 
2531 static int bc_sendto(struct rpc_rqst *req)
2532 {
2533 	struct xdr_buf *xdr = &req->rq_snd_buf;
2534 	struct sock_xprt *transport =
2535 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2536 	struct msghdr msg = {
2537 		.msg_flags	= 0,
2538 	};
2539 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2540 					 (u32)xdr->len);
2541 	unsigned int sent = 0;
2542 	int err;
2543 
2544 	req->rq_xtime = ktime_get();
2545 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2546 	xdr_free_bvec(xdr);
2547 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2548 		return -EAGAIN;
2549 	return sent;
2550 }
2551 
2552 /**
2553  * bc_send_request - Send a backchannel Call on a TCP socket
2554  * @req: rpc_rqst containing Call message to be sent
2555  *
2556  * xpt_mutex ensures @rqstp's whole message is written to the socket
2557  * without interruption.
2558  *
2559  * Return values:
2560  *   %0 if the message was sent successfully
2561  *   %ENOTCONN if the message was not sent
2562  */
2563 static int bc_send_request(struct rpc_rqst *req)
2564 {
2565 	struct svc_xprt	*xprt;
2566 	int len;
2567 
2568 	/*
2569 	 * Get the server socket associated with this callback xprt
2570 	 */
2571 	xprt = req->rq_xprt->bc_xprt;
2572 
2573 	/*
2574 	 * Grab the mutex to serialize data as the connection is shared
2575 	 * with the fore channel
2576 	 */
2577 	mutex_lock(&xprt->xpt_mutex);
2578 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2579 		len = -ENOTCONN;
2580 	else
2581 		len = bc_sendto(req);
2582 	mutex_unlock(&xprt->xpt_mutex);
2583 
2584 	if (len > 0)
2585 		len = 0;
2586 
2587 	return len;
2588 }
2589 
2590 /*
2591  * The close routine. Since this is client initiated, we do nothing
2592  */
2593 
2594 static void bc_close(struct rpc_xprt *xprt)
2595 {
2596 	xprt_disconnect_done(xprt);
2597 }
2598 
2599 /*
2600  * The xprt destroy routine. Again, because this connection is client
2601  * initiated, we do nothing
2602  */
2603 
2604 static void bc_destroy(struct rpc_xprt *xprt)
2605 {
2606 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2607 
2608 	xs_xprt_free(xprt);
2609 	module_put(THIS_MODULE);
2610 }
2611 
2612 static const struct rpc_xprt_ops xs_local_ops = {
2613 	.reserve_xprt		= xprt_reserve_xprt,
2614 	.release_xprt		= xprt_release_xprt,
2615 	.alloc_slot		= xprt_alloc_slot,
2616 	.free_slot		= xprt_free_slot,
2617 	.rpcbind		= xs_local_rpcbind,
2618 	.set_port		= xs_local_set_port,
2619 	.connect		= xs_local_connect,
2620 	.buf_alloc		= rpc_malloc,
2621 	.buf_free		= rpc_free,
2622 	.prepare_request	= xs_stream_prepare_request,
2623 	.send_request		= xs_local_send_request,
2624 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2625 	.close			= xs_close,
2626 	.destroy		= xs_destroy,
2627 	.print_stats		= xs_local_print_stats,
2628 	.enable_swap		= xs_enable_swap,
2629 	.disable_swap		= xs_disable_swap,
2630 };
2631 
2632 static const struct rpc_xprt_ops xs_udp_ops = {
2633 	.set_buffer_size	= xs_udp_set_buffer_size,
2634 	.reserve_xprt		= xprt_reserve_xprt_cong,
2635 	.release_xprt		= xprt_release_xprt_cong,
2636 	.alloc_slot		= xprt_alloc_slot,
2637 	.free_slot		= xprt_free_slot,
2638 	.rpcbind		= rpcb_getport_async,
2639 	.set_port		= xs_set_port,
2640 	.connect		= xs_connect,
2641 	.buf_alloc		= rpc_malloc,
2642 	.buf_free		= rpc_free,
2643 	.send_request		= xs_udp_send_request,
2644 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2645 	.timer			= xs_udp_timer,
2646 	.release_request	= xprt_release_rqst_cong,
2647 	.close			= xs_close,
2648 	.destroy		= xs_destroy,
2649 	.print_stats		= xs_udp_print_stats,
2650 	.enable_swap		= xs_enable_swap,
2651 	.disable_swap		= xs_disable_swap,
2652 	.inject_disconnect	= xs_inject_disconnect,
2653 };
2654 
2655 static const struct rpc_xprt_ops xs_tcp_ops = {
2656 	.reserve_xprt		= xprt_reserve_xprt,
2657 	.release_xprt		= xprt_release_xprt,
2658 	.alloc_slot		= xprt_alloc_slot,
2659 	.free_slot		= xprt_free_slot,
2660 	.rpcbind		= rpcb_getport_async,
2661 	.set_port		= xs_set_port,
2662 	.connect		= xs_connect,
2663 	.buf_alloc		= rpc_malloc,
2664 	.buf_free		= rpc_free,
2665 	.prepare_request	= xs_stream_prepare_request,
2666 	.send_request		= xs_tcp_send_request,
2667 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2668 	.close			= xs_tcp_shutdown,
2669 	.destroy		= xs_destroy,
2670 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2671 	.print_stats		= xs_tcp_print_stats,
2672 	.enable_swap		= xs_enable_swap,
2673 	.disable_swap		= xs_disable_swap,
2674 	.inject_disconnect	= xs_inject_disconnect,
2675 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2676 	.bc_setup		= xprt_setup_bc,
2677 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2678 	.bc_num_slots		= xprt_bc_max_slots,
2679 	.bc_free_rqst		= xprt_free_bc_rqst,
2680 	.bc_destroy		= xprt_destroy_bc,
2681 #endif
2682 };
2683 
2684 /*
2685  * The rpc_xprt_ops for the server backchannel
2686  */
2687 
2688 static const struct rpc_xprt_ops bc_tcp_ops = {
2689 	.reserve_xprt		= xprt_reserve_xprt,
2690 	.release_xprt		= xprt_release_xprt,
2691 	.alloc_slot		= xprt_alloc_slot,
2692 	.free_slot		= xprt_free_slot,
2693 	.buf_alloc		= bc_malloc,
2694 	.buf_free		= bc_free,
2695 	.send_request		= bc_send_request,
2696 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2697 	.close			= bc_close,
2698 	.destroy		= bc_destroy,
2699 	.print_stats		= xs_tcp_print_stats,
2700 	.enable_swap		= xs_enable_swap,
2701 	.disable_swap		= xs_disable_swap,
2702 	.inject_disconnect	= xs_inject_disconnect,
2703 };
2704 
2705 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2706 {
2707 	static const struct sockaddr_in sin = {
2708 		.sin_family		= AF_INET,
2709 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2710 	};
2711 	static const struct sockaddr_in6 sin6 = {
2712 		.sin6_family		= AF_INET6,
2713 		.sin6_addr		= IN6ADDR_ANY_INIT,
2714 	};
2715 
2716 	switch (family) {
2717 	case AF_LOCAL:
2718 		break;
2719 	case AF_INET:
2720 		memcpy(sap, &sin, sizeof(sin));
2721 		break;
2722 	case AF_INET6:
2723 		memcpy(sap, &sin6, sizeof(sin6));
2724 		break;
2725 	default:
2726 		dprintk("RPC:       %s: Bad address family\n", __func__);
2727 		return -EAFNOSUPPORT;
2728 	}
2729 	return 0;
2730 }
2731 
2732 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2733 				      unsigned int slot_table_size,
2734 				      unsigned int max_slot_table_size)
2735 {
2736 	struct rpc_xprt *xprt;
2737 	struct sock_xprt *new;
2738 
2739 	if (args->addrlen > sizeof(xprt->addr)) {
2740 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2741 		return ERR_PTR(-EBADF);
2742 	}
2743 
2744 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2745 			max_slot_table_size);
2746 	if (xprt == NULL) {
2747 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2748 				"rpc_xprt\n");
2749 		return ERR_PTR(-ENOMEM);
2750 	}
2751 
2752 	new = container_of(xprt, struct sock_xprt, xprt);
2753 	mutex_init(&new->recv_mutex);
2754 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2755 	xprt->addrlen = args->addrlen;
2756 	if (args->srcaddr)
2757 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2758 	else {
2759 		int err;
2760 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2761 					(struct sockaddr *)&new->srcaddr);
2762 		if (err != 0) {
2763 			xprt_free(xprt);
2764 			return ERR_PTR(err);
2765 		}
2766 	}
2767 
2768 	return xprt;
2769 }
2770 
2771 static const struct rpc_timeout xs_local_default_timeout = {
2772 	.to_initval = 10 * HZ,
2773 	.to_maxval = 10 * HZ,
2774 	.to_retries = 2,
2775 };
2776 
2777 /**
2778  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2779  * @args: rpc transport creation arguments
2780  *
2781  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2782  */
2783 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2784 {
2785 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2786 	struct sock_xprt *transport;
2787 	struct rpc_xprt *xprt;
2788 	struct rpc_xprt *ret;
2789 
2790 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2791 			xprt_max_tcp_slot_table_entries);
2792 	if (IS_ERR(xprt))
2793 		return xprt;
2794 	transport = container_of(xprt, struct sock_xprt, xprt);
2795 
2796 	xprt->prot = 0;
2797 	xprt->xprt_class = &xs_local_transport;
2798 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2799 
2800 	xprt->bind_timeout = XS_BIND_TO;
2801 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2802 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2803 
2804 	xprt->ops = &xs_local_ops;
2805 	xprt->timeout = &xs_local_default_timeout;
2806 
2807 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2808 	INIT_WORK(&transport->error_worker, xs_error_handle);
2809 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2810 
2811 	switch (sun->sun_family) {
2812 	case AF_LOCAL:
2813 		if (sun->sun_path[0] != '/') {
2814 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2815 					sun->sun_path);
2816 			ret = ERR_PTR(-EINVAL);
2817 			goto out_err;
2818 		}
2819 		xprt_set_bound(xprt);
2820 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2821 		ret = ERR_PTR(xs_local_setup_socket(transport));
2822 		if (ret)
2823 			goto out_err;
2824 		break;
2825 	default:
2826 		ret = ERR_PTR(-EAFNOSUPPORT);
2827 		goto out_err;
2828 	}
2829 
2830 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2831 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2832 
2833 	if (try_module_get(THIS_MODULE))
2834 		return xprt;
2835 	ret = ERR_PTR(-EINVAL);
2836 out_err:
2837 	xs_xprt_free(xprt);
2838 	return ret;
2839 }
2840 
2841 static const struct rpc_timeout xs_udp_default_timeout = {
2842 	.to_initval = 5 * HZ,
2843 	.to_maxval = 30 * HZ,
2844 	.to_increment = 5 * HZ,
2845 	.to_retries = 5,
2846 };
2847 
2848 /**
2849  * xs_setup_udp - Set up transport to use a UDP socket
2850  * @args: rpc transport creation arguments
2851  *
2852  */
2853 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2854 {
2855 	struct sockaddr *addr = args->dstaddr;
2856 	struct rpc_xprt *xprt;
2857 	struct sock_xprt *transport;
2858 	struct rpc_xprt *ret;
2859 
2860 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2861 			xprt_udp_slot_table_entries);
2862 	if (IS_ERR(xprt))
2863 		return xprt;
2864 	transport = container_of(xprt, struct sock_xprt, xprt);
2865 
2866 	xprt->prot = IPPROTO_UDP;
2867 	xprt->xprt_class = &xs_udp_transport;
2868 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2869 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2870 
2871 	xprt->bind_timeout = XS_BIND_TO;
2872 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2873 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2874 
2875 	xprt->ops = &xs_udp_ops;
2876 
2877 	xprt->timeout = &xs_udp_default_timeout;
2878 
2879 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2880 	INIT_WORK(&transport->error_worker, xs_error_handle);
2881 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2882 
2883 	switch (addr->sa_family) {
2884 	case AF_INET:
2885 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2886 			xprt_set_bound(xprt);
2887 
2888 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2889 		break;
2890 	case AF_INET6:
2891 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2892 			xprt_set_bound(xprt);
2893 
2894 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2895 		break;
2896 	default:
2897 		ret = ERR_PTR(-EAFNOSUPPORT);
2898 		goto out_err;
2899 	}
2900 
2901 	if (xprt_bound(xprt))
2902 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2903 				xprt->address_strings[RPC_DISPLAY_ADDR],
2904 				xprt->address_strings[RPC_DISPLAY_PORT],
2905 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2906 	else
2907 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2908 				xprt->address_strings[RPC_DISPLAY_ADDR],
2909 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2910 
2911 	if (try_module_get(THIS_MODULE))
2912 		return xprt;
2913 	ret = ERR_PTR(-EINVAL);
2914 out_err:
2915 	xs_xprt_free(xprt);
2916 	return ret;
2917 }
2918 
2919 static const struct rpc_timeout xs_tcp_default_timeout = {
2920 	.to_initval = 60 * HZ,
2921 	.to_maxval = 60 * HZ,
2922 	.to_retries = 2,
2923 };
2924 
2925 /**
2926  * xs_setup_tcp - Set up transport to use a TCP socket
2927  * @args: rpc transport creation arguments
2928  *
2929  */
2930 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2931 {
2932 	struct sockaddr *addr = args->dstaddr;
2933 	struct rpc_xprt *xprt;
2934 	struct sock_xprt *transport;
2935 	struct rpc_xprt *ret;
2936 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2937 
2938 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2939 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2940 
2941 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2942 			max_slot_table_size);
2943 	if (IS_ERR(xprt))
2944 		return xprt;
2945 	transport = container_of(xprt, struct sock_xprt, xprt);
2946 
2947 	xprt->prot = IPPROTO_TCP;
2948 	xprt->xprt_class = &xs_tcp_transport;
2949 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2950 
2951 	xprt->bind_timeout = XS_BIND_TO;
2952 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2953 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2954 
2955 	xprt->ops = &xs_tcp_ops;
2956 	xprt->timeout = &xs_tcp_default_timeout;
2957 
2958 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2959 	xprt->connect_timeout = xprt->timeout->to_initval *
2960 		(xprt->timeout->to_retries + 1);
2961 
2962 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2963 	INIT_WORK(&transport->error_worker, xs_error_handle);
2964 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2965 
2966 	switch (addr->sa_family) {
2967 	case AF_INET:
2968 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2969 			xprt_set_bound(xprt);
2970 
2971 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2972 		break;
2973 	case AF_INET6:
2974 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2975 			xprt_set_bound(xprt);
2976 
2977 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2978 		break;
2979 	default:
2980 		ret = ERR_PTR(-EAFNOSUPPORT);
2981 		goto out_err;
2982 	}
2983 
2984 	if (xprt_bound(xprt))
2985 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2986 				xprt->address_strings[RPC_DISPLAY_ADDR],
2987 				xprt->address_strings[RPC_DISPLAY_PORT],
2988 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2989 	else
2990 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2991 				xprt->address_strings[RPC_DISPLAY_ADDR],
2992 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2993 
2994 	if (try_module_get(THIS_MODULE))
2995 		return xprt;
2996 	ret = ERR_PTR(-EINVAL);
2997 out_err:
2998 	xs_xprt_free(xprt);
2999 	return ret;
3000 }
3001 
3002 /**
3003  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3004  * @args: rpc transport creation arguments
3005  *
3006  */
3007 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3008 {
3009 	struct sockaddr *addr = args->dstaddr;
3010 	struct rpc_xprt *xprt;
3011 	struct sock_xprt *transport;
3012 	struct svc_sock *bc_sock;
3013 	struct rpc_xprt *ret;
3014 
3015 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3016 			xprt_tcp_slot_table_entries);
3017 	if (IS_ERR(xprt))
3018 		return xprt;
3019 	transport = container_of(xprt, struct sock_xprt, xprt);
3020 
3021 	xprt->prot = IPPROTO_TCP;
3022 	xprt->xprt_class = &xs_bc_tcp_transport;
3023 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3024 	xprt->timeout = &xs_tcp_default_timeout;
3025 
3026 	/* backchannel */
3027 	xprt_set_bound(xprt);
3028 	xprt->bind_timeout = 0;
3029 	xprt->reestablish_timeout = 0;
3030 	xprt->idle_timeout = 0;
3031 
3032 	xprt->ops = &bc_tcp_ops;
3033 
3034 	switch (addr->sa_family) {
3035 	case AF_INET:
3036 		xs_format_peer_addresses(xprt, "tcp",
3037 					 RPCBIND_NETID_TCP);
3038 		break;
3039 	case AF_INET6:
3040 		xs_format_peer_addresses(xprt, "tcp",
3041 				   RPCBIND_NETID_TCP6);
3042 		break;
3043 	default:
3044 		ret = ERR_PTR(-EAFNOSUPPORT);
3045 		goto out_err;
3046 	}
3047 
3048 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3049 			xprt->address_strings[RPC_DISPLAY_ADDR],
3050 			xprt->address_strings[RPC_DISPLAY_PORT],
3051 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3052 
3053 	/*
3054 	 * Once we've associated a backchannel xprt with a connection,
3055 	 * we want to keep it around as long as the connection lasts,
3056 	 * in case we need to start using it for a backchannel again;
3057 	 * this reference won't be dropped until bc_xprt is destroyed.
3058 	 */
3059 	xprt_get(xprt);
3060 	args->bc_xprt->xpt_bc_xprt = xprt;
3061 	xprt->bc_xprt = args->bc_xprt;
3062 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3063 	transport->sock = bc_sock->sk_sock;
3064 	transport->inet = bc_sock->sk_sk;
3065 
3066 	/*
3067 	 * Since we don't want connections for the backchannel, we set
3068 	 * the xprt status to connected
3069 	 */
3070 	xprt_set_connected(xprt);
3071 
3072 	if (try_module_get(THIS_MODULE))
3073 		return xprt;
3074 
3075 	args->bc_xprt->xpt_bc_xprt = NULL;
3076 	args->bc_xprt->xpt_bc_xps = NULL;
3077 	xprt_put(xprt);
3078 	ret = ERR_PTR(-EINVAL);
3079 out_err:
3080 	xs_xprt_free(xprt);
3081 	return ret;
3082 }
3083 
3084 static struct xprt_class	xs_local_transport = {
3085 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3086 	.name		= "named UNIX socket",
3087 	.owner		= THIS_MODULE,
3088 	.ident		= XPRT_TRANSPORT_LOCAL,
3089 	.setup		= xs_setup_local,
3090 	.netid		= { "" },
3091 };
3092 
3093 static struct xprt_class	xs_udp_transport = {
3094 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3095 	.name		= "udp",
3096 	.owner		= THIS_MODULE,
3097 	.ident		= XPRT_TRANSPORT_UDP,
3098 	.setup		= xs_setup_udp,
3099 	.netid		= { "udp", "udp6", "" },
3100 };
3101 
3102 static struct xprt_class	xs_tcp_transport = {
3103 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3104 	.name		= "tcp",
3105 	.owner		= THIS_MODULE,
3106 	.ident		= XPRT_TRANSPORT_TCP,
3107 	.setup		= xs_setup_tcp,
3108 	.netid		= { "tcp", "tcp6", "" },
3109 };
3110 
3111 static struct xprt_class	xs_bc_tcp_transport = {
3112 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3113 	.name		= "tcp NFSv4.1 backchannel",
3114 	.owner		= THIS_MODULE,
3115 	.ident		= XPRT_TRANSPORT_BC_TCP,
3116 	.setup		= xs_setup_bc_tcp,
3117 	.netid		= { "" },
3118 };
3119 
3120 /**
3121  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3122  *
3123  */
3124 int init_socket_xprt(void)
3125 {
3126 	if (!sunrpc_table_header)
3127 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3128 
3129 	xprt_register_transport(&xs_local_transport);
3130 	xprt_register_transport(&xs_udp_transport);
3131 	xprt_register_transport(&xs_tcp_transport);
3132 	xprt_register_transport(&xs_bc_tcp_transport);
3133 
3134 	return 0;
3135 }
3136 
3137 /**
3138  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3139  *
3140  */
3141 void cleanup_socket_xprt(void)
3142 {
3143 	if (sunrpc_table_header) {
3144 		unregister_sysctl_table(sunrpc_table_header);
3145 		sunrpc_table_header = NULL;
3146 	}
3147 
3148 	xprt_unregister_transport(&xs_local_transport);
3149 	xprt_unregister_transport(&xs_udp_transport);
3150 	xprt_unregister_transport(&xs_tcp_transport);
3151 	xprt_unregister_transport(&xs_bc_tcp_transport);
3152 }
3153 
3154 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3155 {
3156 	return param_set_uint_minmax(val, kp,
3157 			RPC_MIN_RESVPORT,
3158 			RPC_MAX_RESVPORT);
3159 }
3160 
3161 static const struct kernel_param_ops param_ops_portnr = {
3162 	.set = param_set_portnr,
3163 	.get = param_get_uint,
3164 };
3165 
3166 #define param_check_portnr(name, p) \
3167 	__param_check(name, p, unsigned int);
3168 
3169 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3170 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3171 
3172 static int param_set_slot_table_size(const char *val,
3173 				     const struct kernel_param *kp)
3174 {
3175 	return param_set_uint_minmax(val, kp,
3176 			RPC_MIN_SLOT_TABLE,
3177 			RPC_MAX_SLOT_TABLE);
3178 }
3179 
3180 static const struct kernel_param_ops param_ops_slot_table_size = {
3181 	.set = param_set_slot_table_size,
3182 	.get = param_get_uint,
3183 };
3184 
3185 #define param_check_slot_table_size(name, p) \
3186 	__param_check(name, p, unsigned int);
3187 
3188 static int param_set_max_slot_table_size(const char *val,
3189 				     const struct kernel_param *kp)
3190 {
3191 	return param_set_uint_minmax(val, kp,
3192 			RPC_MIN_SLOT_TABLE,
3193 			RPC_MAX_SLOT_TABLE_LIMIT);
3194 }
3195 
3196 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3197 	.set = param_set_max_slot_table_size,
3198 	.get = param_get_uint,
3199 };
3200 
3201 #define param_check_max_slot_table_size(name, p) \
3202 	__param_check(name, p, unsigned int);
3203 
3204 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3205 		   slot_table_size, 0644);
3206 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3207 		   max_slot_table_size, 0644);
3208 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3209 		   slot_table_size, 0644);
3210