xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 28dce2c4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/highmem.h>
52 #include <linux/uio.h>
53 #include <linux/sched/mm.h>
54 
55 #include <trace/events/sunrpc.h>
56 
57 #include "socklib.h"
58 #include "sunrpc.h"
59 
60 static void xs_close(struct rpc_xprt *xprt);
61 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
62 		struct socket *sock);
63 
64 /*
65  * xprtsock tunables
66  */
67 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
68 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
69 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
70 
71 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
72 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
73 
74 #define XS_TCP_LINGER_TO	(15U * HZ)
75 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
76 
77 /*
78  * We can register our own files under /proc/sys/sunrpc by
79  * calling register_sysctl_table() again.  The files in that
80  * directory become the union of all files registered there.
81  *
82  * We simply need to make sure that we don't collide with
83  * someone else's file names!
84  */
85 
86 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
87 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
88 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
89 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
90 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
91 
92 static struct ctl_table_header *sunrpc_table_header;
93 
94 /*
95  * FIXME: changing the UDP slot table size should also resize the UDP
96  *        socket buffers for existing UDP transports
97  */
98 static struct ctl_table xs_tunables_table[] = {
99 	{
100 		.procname	= "udp_slot_table_entries",
101 		.data		= &xprt_udp_slot_table_entries,
102 		.maxlen		= sizeof(unsigned int),
103 		.mode		= 0644,
104 		.proc_handler	= proc_dointvec_minmax,
105 		.extra1		= &min_slot_table_size,
106 		.extra2		= &max_slot_table_size
107 	},
108 	{
109 		.procname	= "tcp_slot_table_entries",
110 		.data		= &xprt_tcp_slot_table_entries,
111 		.maxlen		= sizeof(unsigned int),
112 		.mode		= 0644,
113 		.proc_handler	= proc_dointvec_minmax,
114 		.extra1		= &min_slot_table_size,
115 		.extra2		= &max_slot_table_size
116 	},
117 	{
118 		.procname	= "tcp_max_slot_table_entries",
119 		.data		= &xprt_max_tcp_slot_table_entries,
120 		.maxlen		= sizeof(unsigned int),
121 		.mode		= 0644,
122 		.proc_handler	= proc_dointvec_minmax,
123 		.extra1		= &min_slot_table_size,
124 		.extra2		= &max_tcp_slot_table_limit
125 	},
126 	{
127 		.procname	= "min_resvport",
128 		.data		= &xprt_min_resvport,
129 		.maxlen		= sizeof(unsigned int),
130 		.mode		= 0644,
131 		.proc_handler	= proc_dointvec_minmax,
132 		.extra1		= &xprt_min_resvport_limit,
133 		.extra2		= &xprt_max_resvport_limit
134 	},
135 	{
136 		.procname	= "max_resvport",
137 		.data		= &xprt_max_resvport,
138 		.maxlen		= sizeof(unsigned int),
139 		.mode		= 0644,
140 		.proc_handler	= proc_dointvec_minmax,
141 		.extra1		= &xprt_min_resvport_limit,
142 		.extra2		= &xprt_max_resvport_limit
143 	},
144 	{
145 		.procname	= "tcp_fin_timeout",
146 		.data		= &xs_tcp_fin_timeout,
147 		.maxlen		= sizeof(xs_tcp_fin_timeout),
148 		.mode		= 0644,
149 		.proc_handler	= proc_dointvec_jiffies,
150 	},
151 	{ },
152 };
153 
154 static struct ctl_table sunrpc_table[] = {
155 	{
156 		.procname	= "sunrpc",
157 		.mode		= 0555,
158 		.child		= xs_tunables_table
159 	},
160 	{ },
161 };
162 
163 /*
164  * Wait duration for a reply from the RPC portmapper.
165  */
166 #define XS_BIND_TO		(60U * HZ)
167 
168 /*
169  * Delay if a UDP socket connect error occurs.  This is most likely some
170  * kind of resource problem on the local host.
171  */
172 #define XS_UDP_REEST_TO		(2U * HZ)
173 
174 /*
175  * The reestablish timeout allows clients to delay for a bit before attempting
176  * to reconnect to a server that just dropped our connection.
177  *
178  * We implement an exponential backoff when trying to reestablish a TCP
179  * transport connection with the server.  Some servers like to drop a TCP
180  * connection when they are overworked, so we start with a short timeout and
181  * increase over time if the server is down or not responding.
182  */
183 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
184 
185 /*
186  * TCP idle timeout; client drops the transport socket if it is idle
187  * for this long.  Note that we also timeout UDP sockets to prevent
188  * holding port numbers when there is no RPC traffic.
189  */
190 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
191 
192 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
193 # undef  RPC_DEBUG_DATA
194 # define RPCDBG_FACILITY	RPCDBG_TRANS
195 #endif
196 
197 #ifdef RPC_DEBUG_DATA
198 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
199 {
200 	u8 *buf = (u8 *) packet;
201 	int j;
202 
203 	dprintk("RPC:       %s\n", msg);
204 	for (j = 0; j < count && j < 128; j += 4) {
205 		if (!(j & 31)) {
206 			if (j)
207 				dprintk("\n");
208 			dprintk("0x%04x ", j);
209 		}
210 		dprintk("%02x%02x%02x%02x ",
211 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
212 	}
213 	dprintk("\n");
214 }
215 #else
216 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
217 {
218 	/* NOP */
219 }
220 #endif
221 
222 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
223 {
224 	return (struct rpc_xprt *) sk->sk_user_data;
225 }
226 
227 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
228 {
229 	return (struct sockaddr *) &xprt->addr;
230 }
231 
232 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
233 {
234 	return (struct sockaddr_un *) &xprt->addr;
235 }
236 
237 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
238 {
239 	return (struct sockaddr_in *) &xprt->addr;
240 }
241 
242 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
243 {
244 	return (struct sockaddr_in6 *) &xprt->addr;
245 }
246 
247 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
248 {
249 	struct sockaddr *sap = xs_addr(xprt);
250 	struct sockaddr_in6 *sin6;
251 	struct sockaddr_in *sin;
252 	struct sockaddr_un *sun;
253 	char buf[128];
254 
255 	switch (sap->sa_family) {
256 	case AF_LOCAL:
257 		sun = xs_addr_un(xprt);
258 		strlcpy(buf, sun->sun_path, sizeof(buf));
259 		xprt->address_strings[RPC_DISPLAY_ADDR] =
260 						kstrdup(buf, GFP_KERNEL);
261 		break;
262 	case AF_INET:
263 		(void)rpc_ntop(sap, buf, sizeof(buf));
264 		xprt->address_strings[RPC_DISPLAY_ADDR] =
265 						kstrdup(buf, GFP_KERNEL);
266 		sin = xs_addr_in(xprt);
267 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
268 		break;
269 	case AF_INET6:
270 		(void)rpc_ntop(sap, buf, sizeof(buf));
271 		xprt->address_strings[RPC_DISPLAY_ADDR] =
272 						kstrdup(buf, GFP_KERNEL);
273 		sin6 = xs_addr_in6(xprt);
274 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
275 		break;
276 	default:
277 		BUG();
278 	}
279 
280 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
281 }
282 
283 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
284 {
285 	struct sockaddr *sap = xs_addr(xprt);
286 	char buf[128];
287 
288 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
290 
291 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
292 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
293 }
294 
295 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
296 				     const char *protocol,
297 				     const char *netid)
298 {
299 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
300 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
301 	xs_format_common_peer_addresses(xprt);
302 	xs_format_common_peer_ports(xprt);
303 }
304 
305 static void xs_update_peer_port(struct rpc_xprt *xprt)
306 {
307 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
308 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
309 
310 	xs_format_common_peer_ports(xprt);
311 }
312 
313 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
314 {
315 	unsigned int i;
316 
317 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
318 		switch (i) {
319 		case RPC_DISPLAY_PROTO:
320 		case RPC_DISPLAY_NETID:
321 			continue;
322 		default:
323 			kfree(xprt->address_strings[i]);
324 		}
325 }
326 
327 static size_t
328 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
329 {
330 	size_t i,n;
331 
332 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
333 		return want;
334 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
335 	for (i = 0; i < n; i++) {
336 		if (buf->pages[i])
337 			continue;
338 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
339 		if (!buf->pages[i]) {
340 			i *= PAGE_SIZE;
341 			return i > buf->page_base ? i - buf->page_base : 0;
342 		}
343 	}
344 	return want;
345 }
346 
347 static ssize_t
348 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
349 {
350 	ssize_t ret;
351 	if (seek != 0)
352 		iov_iter_advance(&msg->msg_iter, seek);
353 	ret = sock_recvmsg(sock, msg, flags);
354 	return ret > 0 ? ret + seek : ret;
355 }
356 
357 static ssize_t
358 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
359 		struct kvec *kvec, size_t count, size_t seek)
360 {
361 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
362 	return xs_sock_recvmsg(sock, msg, flags, seek);
363 }
364 
365 static ssize_t
366 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
367 		struct bio_vec *bvec, unsigned long nr, size_t count,
368 		size_t seek)
369 {
370 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
371 	return xs_sock_recvmsg(sock, msg, flags, seek);
372 }
373 
374 static ssize_t
375 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
376 		size_t count)
377 {
378 	iov_iter_discard(&msg->msg_iter, READ, count);
379 	return sock_recvmsg(sock, msg, flags);
380 }
381 
382 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
383 static void
384 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
385 {
386 	struct bvec_iter bi = {
387 		.bi_size = count,
388 	};
389 	struct bio_vec bv;
390 
391 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
392 	for_each_bvec(bv, bvec, bi, bi)
393 		flush_dcache_page(bv.bv_page);
394 }
395 #else
396 static inline void
397 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
398 {
399 }
400 #endif
401 
402 static ssize_t
403 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
404 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
405 {
406 	size_t want, seek_init = seek, offset = 0;
407 	ssize_t ret;
408 
409 	want = min_t(size_t, count, buf->head[0].iov_len);
410 	if (seek < want) {
411 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
412 		if (ret <= 0)
413 			goto sock_err;
414 		offset += ret;
415 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
416 			goto out;
417 		if (ret != want)
418 			goto out;
419 		seek = 0;
420 	} else {
421 		seek -= want;
422 		offset += want;
423 	}
424 
425 	want = xs_alloc_sparse_pages(buf,
426 			min_t(size_t, count - offset, buf->page_len),
427 			GFP_KERNEL);
428 	if (seek < want) {
429 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
430 				xdr_buf_pagecount(buf),
431 				want + buf->page_base,
432 				seek + buf->page_base);
433 		if (ret <= 0)
434 			goto sock_err;
435 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
436 		ret -= buf->page_base;
437 		offset += ret;
438 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
439 			goto out;
440 		if (ret != want)
441 			goto out;
442 		seek = 0;
443 	} else {
444 		seek -= want;
445 		offset += want;
446 	}
447 
448 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
449 	if (seek < want) {
450 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
451 		if (ret <= 0)
452 			goto sock_err;
453 		offset += ret;
454 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
455 			goto out;
456 		if (ret != want)
457 			goto out;
458 	} else if (offset < seek_init)
459 		offset = seek_init;
460 	ret = -EMSGSIZE;
461 out:
462 	*read = offset - seek_init;
463 	return ret;
464 sock_err:
465 	offset += seek;
466 	goto out;
467 }
468 
469 static void
470 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
471 {
472 	if (!transport->recv.copied) {
473 		if (buf->head[0].iov_len >= transport->recv.offset)
474 			memcpy(buf->head[0].iov_base,
475 					&transport->recv.xid,
476 					transport->recv.offset);
477 		transport->recv.copied = transport->recv.offset;
478 	}
479 }
480 
481 static bool
482 xs_read_stream_request_done(struct sock_xprt *transport)
483 {
484 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
485 }
486 
487 static void
488 xs_read_stream_check_eor(struct sock_xprt *transport,
489 		struct msghdr *msg)
490 {
491 	if (xs_read_stream_request_done(transport))
492 		msg->msg_flags |= MSG_EOR;
493 }
494 
495 static ssize_t
496 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
497 		int flags, struct rpc_rqst *req)
498 {
499 	struct xdr_buf *buf = &req->rq_private_buf;
500 	size_t want, read;
501 	ssize_t ret;
502 
503 	xs_read_header(transport, buf);
504 
505 	want = transport->recv.len - transport->recv.offset;
506 	if (want != 0) {
507 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
508 				transport->recv.copied + want,
509 				transport->recv.copied,
510 				&read);
511 		transport->recv.offset += read;
512 		transport->recv.copied += read;
513 	}
514 
515 	if (transport->recv.offset == transport->recv.len)
516 		xs_read_stream_check_eor(transport, msg);
517 
518 	if (want == 0)
519 		return 0;
520 
521 	switch (ret) {
522 	default:
523 		break;
524 	case -EFAULT:
525 	case -EMSGSIZE:
526 		msg->msg_flags |= MSG_TRUNC;
527 		return read;
528 	case 0:
529 		return -ESHUTDOWN;
530 	}
531 	return ret < 0 ? ret : read;
532 }
533 
534 static size_t
535 xs_read_stream_headersize(bool isfrag)
536 {
537 	if (isfrag)
538 		return sizeof(__be32);
539 	return 3 * sizeof(__be32);
540 }
541 
542 static ssize_t
543 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
544 		int flags, size_t want, size_t seek)
545 {
546 	struct kvec kvec = {
547 		.iov_base = &transport->recv.fraghdr,
548 		.iov_len = want,
549 	};
550 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
551 }
552 
553 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
554 static ssize_t
555 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
556 {
557 	struct rpc_xprt *xprt = &transport->xprt;
558 	struct rpc_rqst *req;
559 	ssize_t ret;
560 
561 	/* Is this transport associated with the backchannel? */
562 	if (!xprt->bc_serv)
563 		return -ESHUTDOWN;
564 
565 	/* Look up and lock the request corresponding to the given XID */
566 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
567 	if (!req) {
568 		printk(KERN_WARNING "Callback slot table overflowed\n");
569 		return -ESHUTDOWN;
570 	}
571 	if (transport->recv.copied && !req->rq_private_buf.len)
572 		return -ESHUTDOWN;
573 
574 	ret = xs_read_stream_request(transport, msg, flags, req);
575 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
576 		xprt_complete_bc_request(req, transport->recv.copied);
577 	else
578 		req->rq_private_buf.len = transport->recv.copied;
579 
580 	return ret;
581 }
582 #else /* CONFIG_SUNRPC_BACKCHANNEL */
583 static ssize_t
584 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
585 {
586 	return -ESHUTDOWN;
587 }
588 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
589 
590 static ssize_t
591 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
592 {
593 	struct rpc_xprt *xprt = &transport->xprt;
594 	struct rpc_rqst *req;
595 	ssize_t ret = 0;
596 
597 	/* Look up and lock the request corresponding to the given XID */
598 	spin_lock(&xprt->queue_lock);
599 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
600 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
601 		msg->msg_flags |= MSG_TRUNC;
602 		goto out;
603 	}
604 	xprt_pin_rqst(req);
605 	spin_unlock(&xprt->queue_lock);
606 
607 	ret = xs_read_stream_request(transport, msg, flags, req);
608 
609 	spin_lock(&xprt->queue_lock);
610 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
611 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
612 	else
613 		req->rq_private_buf.len = transport->recv.copied;
614 	xprt_unpin_rqst(req);
615 out:
616 	spin_unlock(&xprt->queue_lock);
617 	return ret;
618 }
619 
620 static ssize_t
621 xs_read_stream(struct sock_xprt *transport, int flags)
622 {
623 	struct msghdr msg = { 0 };
624 	size_t want, read = 0;
625 	ssize_t ret = 0;
626 
627 	if (transport->recv.len == 0) {
628 		want = xs_read_stream_headersize(transport->recv.copied != 0);
629 		ret = xs_read_stream_header(transport, &msg, flags, want,
630 				transport->recv.offset);
631 		if (ret <= 0)
632 			goto out_err;
633 		transport->recv.offset = ret;
634 		if (transport->recv.offset != want)
635 			return transport->recv.offset;
636 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
637 			RPC_FRAGMENT_SIZE_MASK;
638 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
639 		read = ret;
640 	}
641 
642 	switch (be32_to_cpu(transport->recv.calldir)) {
643 	default:
644 		msg.msg_flags |= MSG_TRUNC;
645 		break;
646 	case RPC_CALL:
647 		ret = xs_read_stream_call(transport, &msg, flags);
648 		break;
649 	case RPC_REPLY:
650 		ret = xs_read_stream_reply(transport, &msg, flags);
651 	}
652 	if (msg.msg_flags & MSG_TRUNC) {
653 		transport->recv.calldir = cpu_to_be32(-1);
654 		transport->recv.copied = -1;
655 	}
656 	if (ret < 0)
657 		goto out_err;
658 	read += ret;
659 	if (transport->recv.offset < transport->recv.len) {
660 		if (!(msg.msg_flags & MSG_TRUNC))
661 			return read;
662 		msg.msg_flags = 0;
663 		ret = xs_read_discard(transport->sock, &msg, flags,
664 				transport->recv.len - transport->recv.offset);
665 		if (ret <= 0)
666 			goto out_err;
667 		transport->recv.offset += ret;
668 		read += ret;
669 		if (transport->recv.offset != transport->recv.len)
670 			return read;
671 	}
672 	if (xs_read_stream_request_done(transport)) {
673 		trace_xs_stream_read_request(transport);
674 		transport->recv.copied = 0;
675 	}
676 	transport->recv.offset = 0;
677 	transport->recv.len = 0;
678 	return read;
679 out_err:
680 	return ret != 0 ? ret : -ESHUTDOWN;
681 }
682 
683 static __poll_t xs_poll_socket(struct sock_xprt *transport)
684 {
685 	return transport->sock->ops->poll(transport->file, transport->sock,
686 			NULL);
687 }
688 
689 static bool xs_poll_socket_readable(struct sock_xprt *transport)
690 {
691 	__poll_t events = xs_poll_socket(transport);
692 
693 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
694 }
695 
696 static void xs_poll_check_readable(struct sock_xprt *transport)
697 {
698 
699 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
700 	if (!xs_poll_socket_readable(transport))
701 		return;
702 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
703 		queue_work(xprtiod_workqueue, &transport->recv_worker);
704 }
705 
706 static void xs_stream_data_receive(struct sock_xprt *transport)
707 {
708 	size_t read = 0;
709 	ssize_t ret = 0;
710 
711 	mutex_lock(&transport->recv_mutex);
712 	if (transport->sock == NULL)
713 		goto out;
714 	for (;;) {
715 		ret = xs_read_stream(transport, MSG_DONTWAIT);
716 		if (ret < 0)
717 			break;
718 		read += ret;
719 		cond_resched();
720 	}
721 	if (ret == -ESHUTDOWN)
722 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
723 	else
724 		xs_poll_check_readable(transport);
725 out:
726 	mutex_unlock(&transport->recv_mutex);
727 	trace_xs_stream_read_data(&transport->xprt, ret, read);
728 }
729 
730 static void xs_stream_data_receive_workfn(struct work_struct *work)
731 {
732 	struct sock_xprt *transport =
733 		container_of(work, struct sock_xprt, recv_worker);
734 	unsigned int pflags = memalloc_nofs_save();
735 
736 	xs_stream_data_receive(transport);
737 	memalloc_nofs_restore(pflags);
738 }
739 
740 static void
741 xs_stream_reset_connect(struct sock_xprt *transport)
742 {
743 	transport->recv.offset = 0;
744 	transport->recv.len = 0;
745 	transport->recv.copied = 0;
746 	transport->xmit.offset = 0;
747 }
748 
749 static void
750 xs_stream_start_connect(struct sock_xprt *transport)
751 {
752 	transport->xprt.stat.connect_count++;
753 	transport->xprt.stat.connect_start = jiffies;
754 }
755 
756 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
757 
758 /**
759  * xs_nospace - handle transmit was incomplete
760  * @req: pointer to RPC request
761  *
762  */
763 static int xs_nospace(struct rpc_rqst *req)
764 {
765 	struct rpc_xprt *xprt = req->rq_xprt;
766 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
767 	struct sock *sk = transport->inet;
768 	int ret = -EAGAIN;
769 
770 	trace_rpc_socket_nospace(req, transport);
771 
772 	/* Protect against races with write_space */
773 	spin_lock(&xprt->transport_lock);
774 
775 	/* Don't race with disconnect */
776 	if (xprt_connected(xprt)) {
777 		/* wait for more buffer space */
778 		sk->sk_write_pending++;
779 		xprt_wait_for_buffer_space(xprt);
780 	} else
781 		ret = -ENOTCONN;
782 
783 	spin_unlock(&xprt->transport_lock);
784 
785 	/* Race breaker in case memory is freed before above code is called */
786 	if (ret == -EAGAIN) {
787 		struct socket_wq *wq;
788 
789 		rcu_read_lock();
790 		wq = rcu_dereference(sk->sk_wq);
791 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
792 		rcu_read_unlock();
793 
794 		sk->sk_write_space(sk);
795 	}
796 	return ret;
797 }
798 
799 static void
800 xs_stream_prepare_request(struct rpc_rqst *req)
801 {
802 	xdr_free_bvec(&req->rq_rcv_buf);
803 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
804 }
805 
806 /*
807  * Determine if the previous message in the stream was aborted before it
808  * could complete transmission.
809  */
810 static bool
811 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
812 {
813 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
814 }
815 
816 /*
817  * Return the stream record marker field for a record of length < 2^31-1
818  */
819 static rpc_fraghdr
820 xs_stream_record_marker(struct xdr_buf *xdr)
821 {
822 	if (!xdr->len)
823 		return 0;
824 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
825 }
826 
827 /**
828  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
829  * @req: pointer to RPC request
830  *
831  * Return values:
832  *        0:	The request has been sent
833  *   EAGAIN:	The socket was blocked, please call again later to
834  *		complete the request
835  * ENOTCONN:	Caller needs to invoke connect logic then call again
836  *    other:	Some other error occurred, the request was not sent
837  */
838 static int xs_local_send_request(struct rpc_rqst *req)
839 {
840 	struct rpc_xprt *xprt = req->rq_xprt;
841 	struct sock_xprt *transport =
842 				container_of(xprt, struct sock_xprt, xprt);
843 	struct xdr_buf *xdr = &req->rq_snd_buf;
844 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
845 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
846 	struct msghdr msg = {
847 		.msg_flags	= XS_SENDMSG_FLAGS,
848 	};
849 	unsigned int sent;
850 	int status;
851 
852 	/* Close the stream if the previous transmission was incomplete */
853 	if (xs_send_request_was_aborted(transport, req)) {
854 		xs_close(xprt);
855 		return -ENOTCONN;
856 	}
857 
858 	xs_pktdump("packet data:",
859 			req->rq_svec->iov_base, req->rq_svec->iov_len);
860 
861 	req->rq_xtime = ktime_get();
862 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
863 				   transport->xmit.offset, rm, &sent);
864 	dprintk("RPC:       %s(%u) = %d\n",
865 			__func__, xdr->len - transport->xmit.offset, status);
866 
867 	if (status == -EAGAIN && sock_writeable(transport->inet))
868 		status = -ENOBUFS;
869 
870 	if (likely(sent > 0) || status == 0) {
871 		transport->xmit.offset += sent;
872 		req->rq_bytes_sent = transport->xmit.offset;
873 		if (likely(req->rq_bytes_sent >= msglen)) {
874 			req->rq_xmit_bytes_sent += transport->xmit.offset;
875 			transport->xmit.offset = 0;
876 			return 0;
877 		}
878 		status = -EAGAIN;
879 	}
880 
881 	switch (status) {
882 	case -ENOBUFS:
883 		break;
884 	case -EAGAIN:
885 		status = xs_nospace(req);
886 		break;
887 	default:
888 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
889 			-status);
890 		fallthrough;
891 	case -EPIPE:
892 		xs_close(xprt);
893 		status = -ENOTCONN;
894 	}
895 
896 	return status;
897 }
898 
899 /**
900  * xs_udp_send_request - write an RPC request to a UDP socket
901  * @req: pointer to RPC request
902  *
903  * Return values:
904  *        0:	The request has been sent
905  *   EAGAIN:	The socket was blocked, please call again later to
906  *		complete the request
907  * ENOTCONN:	Caller needs to invoke connect logic then call again
908  *    other:	Some other error occurred, the request was not sent
909  */
910 static int xs_udp_send_request(struct rpc_rqst *req)
911 {
912 	struct rpc_xprt *xprt = req->rq_xprt;
913 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
914 	struct xdr_buf *xdr = &req->rq_snd_buf;
915 	struct msghdr msg = {
916 		.msg_name	= xs_addr(xprt),
917 		.msg_namelen	= xprt->addrlen,
918 		.msg_flags	= XS_SENDMSG_FLAGS,
919 	};
920 	unsigned int sent;
921 	int status;
922 
923 	xs_pktdump("packet data:",
924 				req->rq_svec->iov_base,
925 				req->rq_svec->iov_len);
926 
927 	if (!xprt_bound(xprt))
928 		return -ENOTCONN;
929 
930 	if (!xprt_request_get_cong(xprt, req))
931 		return -EBADSLT;
932 
933 	req->rq_xtime = ktime_get();
934 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
935 
936 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
937 			xdr->len, status);
938 
939 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
940 	if (status == -EPERM)
941 		goto process_status;
942 
943 	if (status == -EAGAIN && sock_writeable(transport->inet))
944 		status = -ENOBUFS;
945 
946 	if (sent > 0 || status == 0) {
947 		req->rq_xmit_bytes_sent += sent;
948 		if (sent >= req->rq_slen)
949 			return 0;
950 		/* Still some bytes left; set up for a retry later. */
951 		status = -EAGAIN;
952 	}
953 
954 process_status:
955 	switch (status) {
956 	case -ENOTSOCK:
957 		status = -ENOTCONN;
958 		/* Should we call xs_close() here? */
959 		break;
960 	case -EAGAIN:
961 		status = xs_nospace(req);
962 		break;
963 	case -ENETUNREACH:
964 	case -ENOBUFS:
965 	case -EPIPE:
966 	case -ECONNREFUSED:
967 	case -EPERM:
968 		/* When the server has died, an ICMP port unreachable message
969 		 * prompts ECONNREFUSED. */
970 		break;
971 	default:
972 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
973 			-status);
974 	}
975 
976 	return status;
977 }
978 
979 /**
980  * xs_tcp_send_request - write an RPC request to a TCP socket
981  * @req: pointer to RPC request
982  *
983  * Return values:
984  *        0:	The request has been sent
985  *   EAGAIN:	The socket was blocked, please call again later to
986  *		complete the request
987  * ENOTCONN:	Caller needs to invoke connect logic then call again
988  *    other:	Some other error occurred, the request was not sent
989  *
990  * XXX: In the case of soft timeouts, should we eventually give up
991  *	if sendmsg is not able to make progress?
992  */
993 static int xs_tcp_send_request(struct rpc_rqst *req)
994 {
995 	struct rpc_xprt *xprt = req->rq_xprt;
996 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
997 	struct xdr_buf *xdr = &req->rq_snd_buf;
998 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
999 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1000 	struct msghdr msg = {
1001 		.msg_flags	= XS_SENDMSG_FLAGS,
1002 	};
1003 	bool vm_wait = false;
1004 	unsigned int sent;
1005 	int status;
1006 
1007 	/* Close the stream if the previous transmission was incomplete */
1008 	if (xs_send_request_was_aborted(transport, req)) {
1009 		if (transport->sock != NULL)
1010 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1011 		return -ENOTCONN;
1012 	}
1013 
1014 	xs_pktdump("packet data:",
1015 				req->rq_svec->iov_base,
1016 				req->rq_svec->iov_len);
1017 
1018 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1019 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1020 
1021 	/* Continue transmitting the packet/record. We must be careful
1022 	 * to cope with writespace callbacks arriving _after_ we have
1023 	 * called sendmsg(). */
1024 	req->rq_xtime = ktime_get();
1025 	tcp_sock_set_cork(transport->inet, true);
1026 	while (1) {
1027 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1028 					   transport->xmit.offset, rm, &sent);
1029 
1030 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1031 				xdr->len - transport->xmit.offset, status);
1032 
1033 		/* If we've sent the entire packet, immediately
1034 		 * reset the count of bytes sent. */
1035 		transport->xmit.offset += sent;
1036 		req->rq_bytes_sent = transport->xmit.offset;
1037 		if (likely(req->rq_bytes_sent >= msglen)) {
1038 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1039 			transport->xmit.offset = 0;
1040 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1041 				tcp_sock_set_cork(transport->inet, false);
1042 			return 0;
1043 		}
1044 
1045 		WARN_ON_ONCE(sent == 0 && status == 0);
1046 
1047 		if (status == -EAGAIN ) {
1048 			/*
1049 			 * Return EAGAIN if we're sure we're hitting the
1050 			 * socket send buffer limits.
1051 			 */
1052 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1053 				break;
1054 			/*
1055 			 * Did we hit a memory allocation failure?
1056 			 */
1057 			if (sent == 0) {
1058 				status = -ENOBUFS;
1059 				if (vm_wait)
1060 					break;
1061 				/* Retry, knowing now that we're below the
1062 				 * socket send buffer limit
1063 				 */
1064 				vm_wait = true;
1065 			}
1066 			continue;
1067 		}
1068 		if (status < 0)
1069 			break;
1070 		vm_wait = false;
1071 	}
1072 
1073 	switch (status) {
1074 	case -ENOTSOCK:
1075 		status = -ENOTCONN;
1076 		/* Should we call xs_close() here? */
1077 		break;
1078 	case -EAGAIN:
1079 		status = xs_nospace(req);
1080 		break;
1081 	case -ECONNRESET:
1082 	case -ECONNREFUSED:
1083 	case -ENOTCONN:
1084 	case -EADDRINUSE:
1085 	case -ENOBUFS:
1086 	case -EPIPE:
1087 		break;
1088 	default:
1089 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1090 			-status);
1091 	}
1092 
1093 	return status;
1094 }
1095 
1096 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1097 {
1098 	transport->old_data_ready = sk->sk_data_ready;
1099 	transport->old_state_change = sk->sk_state_change;
1100 	transport->old_write_space = sk->sk_write_space;
1101 	transport->old_error_report = sk->sk_error_report;
1102 }
1103 
1104 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1105 {
1106 	sk->sk_data_ready = transport->old_data_ready;
1107 	sk->sk_state_change = transport->old_state_change;
1108 	sk->sk_write_space = transport->old_write_space;
1109 	sk->sk_error_report = transport->old_error_report;
1110 }
1111 
1112 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1113 {
1114 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1115 
1116 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1117 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1118 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1119 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1120 }
1121 
1122 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1123 {
1124 	set_bit(nr, &transport->sock_state);
1125 	queue_work(xprtiod_workqueue, &transport->error_worker);
1126 }
1127 
1128 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1129 {
1130 	smp_mb__before_atomic();
1131 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1132 	clear_bit(XPRT_CLOSING, &xprt->state);
1133 	xs_sock_reset_state_flags(xprt);
1134 	smp_mb__after_atomic();
1135 }
1136 
1137 /**
1138  * xs_error_report - callback to handle TCP socket state errors
1139  * @sk: socket
1140  *
1141  * Note: we don't call sock_error() since there may be a rpc_task
1142  * using the socket, and so we don't want to clear sk->sk_err.
1143  */
1144 static void xs_error_report(struct sock *sk)
1145 {
1146 	struct sock_xprt *transport;
1147 	struct rpc_xprt *xprt;
1148 
1149 	read_lock_bh(&sk->sk_callback_lock);
1150 	if (!(xprt = xprt_from_sock(sk)))
1151 		goto out;
1152 
1153 	transport = container_of(xprt, struct sock_xprt, xprt);
1154 	transport->xprt_err = -sk->sk_err;
1155 	if (transport->xprt_err == 0)
1156 		goto out;
1157 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1158 			xprt, -transport->xprt_err);
1159 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1160 
1161 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1162 	smp_mb__before_atomic();
1163 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1164  out:
1165 	read_unlock_bh(&sk->sk_callback_lock);
1166 }
1167 
1168 static void xs_reset_transport(struct sock_xprt *transport)
1169 {
1170 	struct socket *sock = transport->sock;
1171 	struct sock *sk = transport->inet;
1172 	struct rpc_xprt *xprt = &transport->xprt;
1173 	struct file *filp = transport->file;
1174 
1175 	if (sk == NULL)
1176 		return;
1177 
1178 	if (atomic_read(&transport->xprt.swapper))
1179 		sk_clear_memalloc(sk);
1180 
1181 	kernel_sock_shutdown(sock, SHUT_RDWR);
1182 
1183 	mutex_lock(&transport->recv_mutex);
1184 	write_lock_bh(&sk->sk_callback_lock);
1185 	transport->inet = NULL;
1186 	transport->sock = NULL;
1187 	transport->file = NULL;
1188 
1189 	sk->sk_user_data = NULL;
1190 
1191 	xs_restore_old_callbacks(transport, sk);
1192 	xprt_clear_connected(xprt);
1193 	write_unlock_bh(&sk->sk_callback_lock);
1194 	xs_sock_reset_connection_flags(xprt);
1195 	/* Reset stream record info */
1196 	xs_stream_reset_connect(transport);
1197 	mutex_unlock(&transport->recv_mutex);
1198 
1199 	trace_rpc_socket_close(xprt, sock);
1200 	fput(filp);
1201 
1202 	xprt_disconnect_done(xprt);
1203 }
1204 
1205 /**
1206  * xs_close - close a socket
1207  * @xprt: transport
1208  *
1209  * This is used when all requests are complete; ie, no DRC state remains
1210  * on the server we want to save.
1211  *
1212  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1213  * xs_reset_transport() zeroing the socket from underneath a writer.
1214  */
1215 static void xs_close(struct rpc_xprt *xprt)
1216 {
1217 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1218 
1219 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1220 
1221 	xs_reset_transport(transport);
1222 	xprt->reestablish_timeout = 0;
1223 }
1224 
1225 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1226 {
1227 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1228 		xprt);
1229 	xprt_disconnect_done(xprt);
1230 }
1231 
1232 static void xs_xprt_free(struct rpc_xprt *xprt)
1233 {
1234 	xs_free_peer_addresses(xprt);
1235 	xprt_free(xprt);
1236 }
1237 
1238 /**
1239  * xs_destroy - prepare to shutdown a transport
1240  * @xprt: doomed transport
1241  *
1242  */
1243 static void xs_destroy(struct rpc_xprt *xprt)
1244 {
1245 	struct sock_xprt *transport = container_of(xprt,
1246 			struct sock_xprt, xprt);
1247 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1248 
1249 	cancel_delayed_work_sync(&transport->connect_worker);
1250 	xs_close(xprt);
1251 	cancel_work_sync(&transport->recv_worker);
1252 	cancel_work_sync(&transport->error_worker);
1253 	xs_xprt_free(xprt);
1254 	module_put(THIS_MODULE);
1255 }
1256 
1257 /**
1258  * xs_udp_data_read_skb - receive callback for UDP sockets
1259  * @xprt: transport
1260  * @sk: socket
1261  * @skb: skbuff
1262  *
1263  */
1264 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1265 		struct sock *sk,
1266 		struct sk_buff *skb)
1267 {
1268 	struct rpc_task *task;
1269 	struct rpc_rqst *rovr;
1270 	int repsize, copied;
1271 	u32 _xid;
1272 	__be32 *xp;
1273 
1274 	repsize = skb->len;
1275 	if (repsize < 4) {
1276 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1277 		return;
1278 	}
1279 
1280 	/* Copy the XID from the skb... */
1281 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1282 	if (xp == NULL)
1283 		return;
1284 
1285 	/* Look up and lock the request corresponding to the given XID */
1286 	spin_lock(&xprt->queue_lock);
1287 	rovr = xprt_lookup_rqst(xprt, *xp);
1288 	if (!rovr)
1289 		goto out_unlock;
1290 	xprt_pin_rqst(rovr);
1291 	xprt_update_rtt(rovr->rq_task);
1292 	spin_unlock(&xprt->queue_lock);
1293 	task = rovr->rq_task;
1294 
1295 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1296 		copied = repsize;
1297 
1298 	/* Suck it into the iovec, verify checksum if not done by hw. */
1299 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1300 		spin_lock(&xprt->queue_lock);
1301 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1302 		goto out_unpin;
1303 	}
1304 
1305 
1306 	spin_lock(&xprt->transport_lock);
1307 	xprt_adjust_cwnd(xprt, task, copied);
1308 	spin_unlock(&xprt->transport_lock);
1309 	spin_lock(&xprt->queue_lock);
1310 	xprt_complete_rqst(task, copied);
1311 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1312 out_unpin:
1313 	xprt_unpin_rqst(rovr);
1314  out_unlock:
1315 	spin_unlock(&xprt->queue_lock);
1316 }
1317 
1318 static void xs_udp_data_receive(struct sock_xprt *transport)
1319 {
1320 	struct sk_buff *skb;
1321 	struct sock *sk;
1322 	int err;
1323 
1324 	mutex_lock(&transport->recv_mutex);
1325 	sk = transport->inet;
1326 	if (sk == NULL)
1327 		goto out;
1328 	for (;;) {
1329 		skb = skb_recv_udp(sk, 0, 1, &err);
1330 		if (skb == NULL)
1331 			break;
1332 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1333 		consume_skb(skb);
1334 		cond_resched();
1335 	}
1336 	xs_poll_check_readable(transport);
1337 out:
1338 	mutex_unlock(&transport->recv_mutex);
1339 }
1340 
1341 static void xs_udp_data_receive_workfn(struct work_struct *work)
1342 {
1343 	struct sock_xprt *transport =
1344 		container_of(work, struct sock_xprt, recv_worker);
1345 	unsigned int pflags = memalloc_nofs_save();
1346 
1347 	xs_udp_data_receive(transport);
1348 	memalloc_nofs_restore(pflags);
1349 }
1350 
1351 /**
1352  * xs_data_ready - "data ready" callback for UDP sockets
1353  * @sk: socket with data to read
1354  *
1355  */
1356 static void xs_data_ready(struct sock *sk)
1357 {
1358 	struct rpc_xprt *xprt;
1359 
1360 	read_lock_bh(&sk->sk_callback_lock);
1361 	dprintk("RPC:       xs_data_ready...\n");
1362 	xprt = xprt_from_sock(sk);
1363 	if (xprt != NULL) {
1364 		struct sock_xprt *transport = container_of(xprt,
1365 				struct sock_xprt, xprt);
1366 		transport->old_data_ready(sk);
1367 		/* Any data means we had a useful conversation, so
1368 		 * then we don't need to delay the next reconnect
1369 		 */
1370 		if (xprt->reestablish_timeout)
1371 			xprt->reestablish_timeout = 0;
1372 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1373 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1374 	}
1375 	read_unlock_bh(&sk->sk_callback_lock);
1376 }
1377 
1378 /*
1379  * Helper function to force a TCP close if the server is sending
1380  * junk and/or it has put us in CLOSE_WAIT
1381  */
1382 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1383 {
1384 	xprt_force_disconnect(xprt);
1385 }
1386 
1387 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1388 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1389 {
1390 	return PAGE_SIZE;
1391 }
1392 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1393 
1394 /**
1395  * xs_tcp_state_change - callback to handle TCP socket state changes
1396  * @sk: socket whose state has changed
1397  *
1398  */
1399 static void xs_tcp_state_change(struct sock *sk)
1400 {
1401 	struct rpc_xprt *xprt;
1402 	struct sock_xprt *transport;
1403 
1404 	read_lock_bh(&sk->sk_callback_lock);
1405 	if (!(xprt = xprt_from_sock(sk)))
1406 		goto out;
1407 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1408 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1409 			sk->sk_state, xprt_connected(xprt),
1410 			sock_flag(sk, SOCK_DEAD),
1411 			sock_flag(sk, SOCK_ZAPPED),
1412 			sk->sk_shutdown);
1413 
1414 	transport = container_of(xprt, struct sock_xprt, xprt);
1415 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1416 	switch (sk->sk_state) {
1417 	case TCP_ESTABLISHED:
1418 		if (!xprt_test_and_set_connected(xprt)) {
1419 			xprt->connect_cookie++;
1420 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1421 			xprt_clear_connecting(xprt);
1422 
1423 			xprt->stat.connect_count++;
1424 			xprt->stat.connect_time += (long)jiffies -
1425 						   xprt->stat.connect_start;
1426 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1427 		}
1428 		break;
1429 	case TCP_FIN_WAIT1:
1430 		/* The client initiated a shutdown of the socket */
1431 		xprt->connect_cookie++;
1432 		xprt->reestablish_timeout = 0;
1433 		set_bit(XPRT_CLOSING, &xprt->state);
1434 		smp_mb__before_atomic();
1435 		clear_bit(XPRT_CONNECTED, &xprt->state);
1436 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1437 		smp_mb__after_atomic();
1438 		break;
1439 	case TCP_CLOSE_WAIT:
1440 		/* The server initiated a shutdown of the socket */
1441 		xprt->connect_cookie++;
1442 		clear_bit(XPRT_CONNECTED, &xprt->state);
1443 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1444 		fallthrough;
1445 	case TCP_CLOSING:
1446 		/*
1447 		 * If the server closed down the connection, make sure that
1448 		 * we back off before reconnecting
1449 		 */
1450 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1451 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1452 		break;
1453 	case TCP_LAST_ACK:
1454 		set_bit(XPRT_CLOSING, &xprt->state);
1455 		smp_mb__before_atomic();
1456 		clear_bit(XPRT_CONNECTED, &xprt->state);
1457 		smp_mb__after_atomic();
1458 		break;
1459 	case TCP_CLOSE:
1460 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1461 					&transport->sock_state))
1462 			xprt_clear_connecting(xprt);
1463 		clear_bit(XPRT_CLOSING, &xprt->state);
1464 		/* Trigger the socket release */
1465 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1466 	}
1467  out:
1468 	read_unlock_bh(&sk->sk_callback_lock);
1469 }
1470 
1471 static void xs_write_space(struct sock *sk)
1472 {
1473 	struct socket_wq *wq;
1474 	struct sock_xprt *transport;
1475 	struct rpc_xprt *xprt;
1476 
1477 	if (!sk->sk_socket)
1478 		return;
1479 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1480 
1481 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1482 		return;
1483 	transport = container_of(xprt, struct sock_xprt, xprt);
1484 	rcu_read_lock();
1485 	wq = rcu_dereference(sk->sk_wq);
1486 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1487 		goto out;
1488 
1489 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1490 	sk->sk_write_pending--;
1491 out:
1492 	rcu_read_unlock();
1493 }
1494 
1495 /**
1496  * xs_udp_write_space - callback invoked when socket buffer space
1497  *                             becomes available
1498  * @sk: socket whose state has changed
1499  *
1500  * Called when more output buffer space is available for this socket.
1501  * We try not to wake our writers until they can make "significant"
1502  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1503  * with a bunch of small requests.
1504  */
1505 static void xs_udp_write_space(struct sock *sk)
1506 {
1507 	read_lock_bh(&sk->sk_callback_lock);
1508 
1509 	/* from net/core/sock.c:sock_def_write_space */
1510 	if (sock_writeable(sk))
1511 		xs_write_space(sk);
1512 
1513 	read_unlock_bh(&sk->sk_callback_lock);
1514 }
1515 
1516 /**
1517  * xs_tcp_write_space - callback invoked when socket buffer space
1518  *                             becomes available
1519  * @sk: socket whose state has changed
1520  *
1521  * Called when more output buffer space is available for this socket.
1522  * We try not to wake our writers until they can make "significant"
1523  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1524  * with a bunch of small requests.
1525  */
1526 static void xs_tcp_write_space(struct sock *sk)
1527 {
1528 	read_lock_bh(&sk->sk_callback_lock);
1529 
1530 	/* from net/core/stream.c:sk_stream_write_space */
1531 	if (sk_stream_is_writeable(sk))
1532 		xs_write_space(sk);
1533 
1534 	read_unlock_bh(&sk->sk_callback_lock);
1535 }
1536 
1537 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1538 {
1539 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1540 	struct sock *sk = transport->inet;
1541 
1542 	if (transport->rcvsize) {
1543 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1544 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1545 	}
1546 	if (transport->sndsize) {
1547 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1548 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1549 		sk->sk_write_space(sk);
1550 	}
1551 }
1552 
1553 /**
1554  * xs_udp_set_buffer_size - set send and receive limits
1555  * @xprt: generic transport
1556  * @sndsize: requested size of send buffer, in bytes
1557  * @rcvsize: requested size of receive buffer, in bytes
1558  *
1559  * Set socket send and receive buffer size limits.
1560  */
1561 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1562 {
1563 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1564 
1565 	transport->sndsize = 0;
1566 	if (sndsize)
1567 		transport->sndsize = sndsize + 1024;
1568 	transport->rcvsize = 0;
1569 	if (rcvsize)
1570 		transport->rcvsize = rcvsize + 1024;
1571 
1572 	xs_udp_do_set_buffer_size(xprt);
1573 }
1574 
1575 /**
1576  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1577  * @xprt: controlling transport
1578  * @task: task that timed out
1579  *
1580  * Adjust the congestion window after a retransmit timeout has occurred.
1581  */
1582 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1583 {
1584 	spin_lock(&xprt->transport_lock);
1585 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1586 	spin_unlock(&xprt->transport_lock);
1587 }
1588 
1589 static int xs_get_random_port(void)
1590 {
1591 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1592 	unsigned short range;
1593 	unsigned short rand;
1594 
1595 	if (max < min)
1596 		return -EADDRINUSE;
1597 	range = max - min + 1;
1598 	rand = (unsigned short) prandom_u32() % range;
1599 	return rand + min;
1600 }
1601 
1602 static unsigned short xs_sock_getport(struct socket *sock)
1603 {
1604 	struct sockaddr_storage buf;
1605 	unsigned short port = 0;
1606 
1607 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1608 		goto out;
1609 	switch (buf.ss_family) {
1610 	case AF_INET6:
1611 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1612 		break;
1613 	case AF_INET:
1614 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1615 	}
1616 out:
1617 	return port;
1618 }
1619 
1620 /**
1621  * xs_set_port - reset the port number in the remote endpoint address
1622  * @xprt: generic transport
1623  * @port: new port number
1624  *
1625  */
1626 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1627 {
1628 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1629 
1630 	rpc_set_port(xs_addr(xprt), port);
1631 	xs_update_peer_port(xprt);
1632 }
1633 
1634 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1635 {
1636 	if (transport->srcport == 0 && transport->xprt.reuseport)
1637 		transport->srcport = xs_sock_getport(sock);
1638 }
1639 
1640 static int xs_get_srcport(struct sock_xprt *transport)
1641 {
1642 	int port = transport->srcport;
1643 
1644 	if (port == 0 && transport->xprt.resvport)
1645 		port = xs_get_random_port();
1646 	return port;
1647 }
1648 
1649 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1650 {
1651 	if (transport->srcport != 0)
1652 		transport->srcport = 0;
1653 	if (!transport->xprt.resvport)
1654 		return 0;
1655 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1656 		return xprt_max_resvport;
1657 	return --port;
1658 }
1659 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1660 {
1661 	struct sockaddr_storage myaddr;
1662 	int err, nloop = 0;
1663 	int port = xs_get_srcport(transport);
1664 	unsigned short last;
1665 
1666 	/*
1667 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1668 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1669 	 * port selection happen implicitly when the socket is used
1670 	 * (for example at connect time).
1671 	 *
1672 	 * This ensures that we can continue to establish TCP
1673 	 * connections even when all local ephemeral ports are already
1674 	 * a part of some TCP connection.  This makes no difference
1675 	 * for UDP sockets, but also doesn't harm them.
1676 	 *
1677 	 * If we're asking for any reserved port (i.e. port == 0 &&
1678 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1679 	 * ensure that port is non-zero and we will bind as needed.
1680 	 */
1681 	if (port <= 0)
1682 		return port;
1683 
1684 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1685 	do {
1686 		rpc_set_port((struct sockaddr *)&myaddr, port);
1687 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1688 				transport->xprt.addrlen);
1689 		if (err == 0) {
1690 			transport->srcport = port;
1691 			break;
1692 		}
1693 		last = port;
1694 		port = xs_next_srcport(transport, port);
1695 		if (port > last)
1696 			nloop++;
1697 	} while (err == -EADDRINUSE && nloop != 2);
1698 
1699 	if (myaddr.ss_family == AF_INET)
1700 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1701 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1702 				port, err ? "failed" : "ok", err);
1703 	else
1704 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1705 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1706 				port, err ? "failed" : "ok", err);
1707 	return err;
1708 }
1709 
1710 /*
1711  * We don't support autobind on AF_LOCAL sockets
1712  */
1713 static void xs_local_rpcbind(struct rpc_task *task)
1714 {
1715 	xprt_set_bound(task->tk_xprt);
1716 }
1717 
1718 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1719 {
1720 }
1721 
1722 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1723 static struct lock_class_key xs_key[2];
1724 static struct lock_class_key xs_slock_key[2];
1725 
1726 static inline void xs_reclassify_socketu(struct socket *sock)
1727 {
1728 	struct sock *sk = sock->sk;
1729 
1730 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1731 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1732 }
1733 
1734 static inline void xs_reclassify_socket4(struct socket *sock)
1735 {
1736 	struct sock *sk = sock->sk;
1737 
1738 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1739 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1740 }
1741 
1742 static inline void xs_reclassify_socket6(struct socket *sock)
1743 {
1744 	struct sock *sk = sock->sk;
1745 
1746 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1747 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1748 }
1749 
1750 static inline void xs_reclassify_socket(int family, struct socket *sock)
1751 {
1752 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1753 		return;
1754 
1755 	switch (family) {
1756 	case AF_LOCAL:
1757 		xs_reclassify_socketu(sock);
1758 		break;
1759 	case AF_INET:
1760 		xs_reclassify_socket4(sock);
1761 		break;
1762 	case AF_INET6:
1763 		xs_reclassify_socket6(sock);
1764 		break;
1765 	}
1766 }
1767 #else
1768 static inline void xs_reclassify_socket(int family, struct socket *sock)
1769 {
1770 }
1771 #endif
1772 
1773 static void xs_dummy_setup_socket(struct work_struct *work)
1774 {
1775 }
1776 
1777 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1778 		struct sock_xprt *transport, int family, int type,
1779 		int protocol, bool reuseport)
1780 {
1781 	struct file *filp;
1782 	struct socket *sock;
1783 	int err;
1784 
1785 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1786 	if (err < 0) {
1787 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1788 				protocol, -err);
1789 		goto out;
1790 	}
1791 	xs_reclassify_socket(family, sock);
1792 
1793 	if (reuseport)
1794 		sock_set_reuseport(sock->sk);
1795 
1796 	err = xs_bind(transport, sock);
1797 	if (err) {
1798 		sock_release(sock);
1799 		goto out;
1800 	}
1801 
1802 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1803 	if (IS_ERR(filp))
1804 		return ERR_CAST(filp);
1805 	transport->file = filp;
1806 
1807 	return sock;
1808 out:
1809 	return ERR_PTR(err);
1810 }
1811 
1812 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1813 				      struct socket *sock)
1814 {
1815 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1816 									xprt);
1817 
1818 	if (!transport->inet) {
1819 		struct sock *sk = sock->sk;
1820 
1821 		write_lock_bh(&sk->sk_callback_lock);
1822 
1823 		xs_save_old_callbacks(transport, sk);
1824 
1825 		sk->sk_user_data = xprt;
1826 		sk->sk_data_ready = xs_data_ready;
1827 		sk->sk_write_space = xs_udp_write_space;
1828 		sock_set_flag(sk, SOCK_FASYNC);
1829 		sk->sk_error_report = xs_error_report;
1830 
1831 		xprt_clear_connected(xprt);
1832 
1833 		/* Reset to new socket */
1834 		transport->sock = sock;
1835 		transport->inet = sk;
1836 
1837 		write_unlock_bh(&sk->sk_callback_lock);
1838 	}
1839 
1840 	xs_stream_start_connect(transport);
1841 
1842 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1843 }
1844 
1845 /**
1846  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1847  * @transport: socket transport to connect
1848  */
1849 static int xs_local_setup_socket(struct sock_xprt *transport)
1850 {
1851 	struct rpc_xprt *xprt = &transport->xprt;
1852 	struct file *filp;
1853 	struct socket *sock;
1854 	int status;
1855 
1856 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1857 					SOCK_STREAM, 0, &sock, 1);
1858 	if (status < 0) {
1859 		dprintk("RPC:       can't create AF_LOCAL "
1860 			"transport socket (%d).\n", -status);
1861 		goto out;
1862 	}
1863 	xs_reclassify_socket(AF_LOCAL, sock);
1864 
1865 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1866 	if (IS_ERR(filp)) {
1867 		status = PTR_ERR(filp);
1868 		goto out;
1869 	}
1870 	transport->file = filp;
1871 
1872 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1873 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1874 
1875 	status = xs_local_finish_connecting(xprt, sock);
1876 	trace_rpc_socket_connect(xprt, sock, status);
1877 	switch (status) {
1878 	case 0:
1879 		dprintk("RPC:       xprt %p connected to %s\n",
1880 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1881 		xprt->stat.connect_count++;
1882 		xprt->stat.connect_time += (long)jiffies -
1883 					   xprt->stat.connect_start;
1884 		xprt_set_connected(xprt);
1885 		break;
1886 	case -ENOBUFS:
1887 		break;
1888 	case -ENOENT:
1889 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1890 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1891 		break;
1892 	case -ECONNREFUSED:
1893 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1894 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1895 		break;
1896 	default:
1897 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1898 				__func__, -status,
1899 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1900 	}
1901 
1902 out:
1903 	xprt_clear_connecting(xprt);
1904 	xprt_wake_pending_tasks(xprt, status);
1905 	return status;
1906 }
1907 
1908 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1909 {
1910 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1911 	int ret;
1912 
1913 	 if (RPC_IS_ASYNC(task)) {
1914 		/*
1915 		 * We want the AF_LOCAL connect to be resolved in the
1916 		 * filesystem namespace of the process making the rpc
1917 		 * call.  Thus we connect synchronously.
1918 		 *
1919 		 * If we want to support asynchronous AF_LOCAL calls,
1920 		 * we'll need to figure out how to pass a namespace to
1921 		 * connect.
1922 		 */
1923 		task->tk_rpc_status = -ENOTCONN;
1924 		rpc_exit(task, -ENOTCONN);
1925 		return;
1926 	}
1927 	ret = xs_local_setup_socket(transport);
1928 	if (ret && !RPC_IS_SOFTCONN(task))
1929 		msleep_interruptible(15000);
1930 }
1931 
1932 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1933 /*
1934  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1935  * know that we have exclusive access to the socket), to guard against
1936  * races with xs_reset_transport.
1937  */
1938 static void xs_set_memalloc(struct rpc_xprt *xprt)
1939 {
1940 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1941 			xprt);
1942 
1943 	/*
1944 	 * If there's no sock, then we have nothing to set. The
1945 	 * reconnecting process will get it for us.
1946 	 */
1947 	if (!transport->inet)
1948 		return;
1949 	if (atomic_read(&xprt->swapper))
1950 		sk_set_memalloc(transport->inet);
1951 }
1952 
1953 /**
1954  * xs_enable_swap - Tag this transport as being used for swap.
1955  * @xprt: transport to tag
1956  *
1957  * Take a reference to this transport on behalf of the rpc_clnt, and
1958  * optionally mark it for swapping if it wasn't already.
1959  */
1960 static int
1961 xs_enable_swap(struct rpc_xprt *xprt)
1962 {
1963 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1964 
1965 	if (atomic_inc_return(&xprt->swapper) != 1)
1966 		return 0;
1967 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1968 		return -ERESTARTSYS;
1969 	if (xs->inet)
1970 		sk_set_memalloc(xs->inet);
1971 	xprt_release_xprt(xprt, NULL);
1972 	return 0;
1973 }
1974 
1975 /**
1976  * xs_disable_swap - Untag this transport as being used for swap.
1977  * @xprt: transport to tag
1978  *
1979  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1980  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1981  */
1982 static void
1983 xs_disable_swap(struct rpc_xprt *xprt)
1984 {
1985 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1986 
1987 	if (!atomic_dec_and_test(&xprt->swapper))
1988 		return;
1989 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1990 		return;
1991 	if (xs->inet)
1992 		sk_clear_memalloc(xs->inet);
1993 	xprt_release_xprt(xprt, NULL);
1994 }
1995 #else
1996 static void xs_set_memalloc(struct rpc_xprt *xprt)
1997 {
1998 }
1999 
2000 static int
2001 xs_enable_swap(struct rpc_xprt *xprt)
2002 {
2003 	return -EINVAL;
2004 }
2005 
2006 static void
2007 xs_disable_swap(struct rpc_xprt *xprt)
2008 {
2009 }
2010 #endif
2011 
2012 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2013 {
2014 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2015 
2016 	if (!transport->inet) {
2017 		struct sock *sk = sock->sk;
2018 
2019 		write_lock_bh(&sk->sk_callback_lock);
2020 
2021 		xs_save_old_callbacks(transport, sk);
2022 
2023 		sk->sk_user_data = xprt;
2024 		sk->sk_data_ready = xs_data_ready;
2025 		sk->sk_write_space = xs_udp_write_space;
2026 		sock_set_flag(sk, SOCK_FASYNC);
2027 
2028 		xprt_set_connected(xprt);
2029 
2030 		/* Reset to new socket */
2031 		transport->sock = sock;
2032 		transport->inet = sk;
2033 
2034 		xs_set_memalloc(xprt);
2035 
2036 		write_unlock_bh(&sk->sk_callback_lock);
2037 	}
2038 	xs_udp_do_set_buffer_size(xprt);
2039 
2040 	xprt->stat.connect_start = jiffies;
2041 }
2042 
2043 static void xs_udp_setup_socket(struct work_struct *work)
2044 {
2045 	struct sock_xprt *transport =
2046 		container_of(work, struct sock_xprt, connect_worker.work);
2047 	struct rpc_xprt *xprt = &transport->xprt;
2048 	struct socket *sock;
2049 	int status = -EIO;
2050 
2051 	sock = xs_create_sock(xprt, transport,
2052 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2053 			IPPROTO_UDP, false);
2054 	if (IS_ERR(sock))
2055 		goto out;
2056 
2057 	dprintk("RPC:       worker connecting xprt %p via %s to "
2058 				"%s (port %s)\n", xprt,
2059 			xprt->address_strings[RPC_DISPLAY_PROTO],
2060 			xprt->address_strings[RPC_DISPLAY_ADDR],
2061 			xprt->address_strings[RPC_DISPLAY_PORT]);
2062 
2063 	xs_udp_finish_connecting(xprt, sock);
2064 	trace_rpc_socket_connect(xprt, sock, 0);
2065 	status = 0;
2066 out:
2067 	xprt_clear_connecting(xprt);
2068 	xprt_unlock_connect(xprt, transport);
2069 	xprt_wake_pending_tasks(xprt, status);
2070 }
2071 
2072 /**
2073  * xs_tcp_shutdown - gracefully shut down a TCP socket
2074  * @xprt: transport
2075  *
2076  * Initiates a graceful shutdown of the TCP socket by calling the
2077  * equivalent of shutdown(SHUT_RDWR);
2078  */
2079 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2080 {
2081 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2082 	struct socket *sock = transport->sock;
2083 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2084 
2085 	if (sock == NULL)
2086 		return;
2087 	switch (skst) {
2088 	default:
2089 		kernel_sock_shutdown(sock, SHUT_RDWR);
2090 		trace_rpc_socket_shutdown(xprt, sock);
2091 		break;
2092 	case TCP_CLOSE:
2093 	case TCP_TIME_WAIT:
2094 		xs_reset_transport(transport);
2095 	}
2096 }
2097 
2098 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2099 		struct socket *sock)
2100 {
2101 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2102 	unsigned int keepidle;
2103 	unsigned int keepcnt;
2104 	unsigned int timeo;
2105 
2106 	spin_lock(&xprt->transport_lock);
2107 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2108 	keepcnt = xprt->timeout->to_retries + 1;
2109 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2110 		(xprt->timeout->to_retries + 1);
2111 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2112 	spin_unlock(&xprt->transport_lock);
2113 
2114 	/* TCP Keepalive options */
2115 	sock_set_keepalive(sock->sk);
2116 	tcp_sock_set_keepidle(sock->sk, keepidle);
2117 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2118 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2119 
2120 	/* TCP user timeout (see RFC5482) */
2121 	tcp_sock_set_user_timeout(sock->sk, timeo);
2122 }
2123 
2124 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2125 		unsigned long connect_timeout,
2126 		unsigned long reconnect_timeout)
2127 {
2128 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2129 	struct rpc_timeout to;
2130 	unsigned long initval;
2131 
2132 	spin_lock(&xprt->transport_lock);
2133 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2134 		xprt->max_reconnect_timeout = reconnect_timeout;
2135 	if (connect_timeout < xprt->connect_timeout) {
2136 		memcpy(&to, xprt->timeout, sizeof(to));
2137 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2138 		/* Arbitrary lower limit */
2139 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2140 			initval = XS_TCP_INIT_REEST_TO << 1;
2141 		to.to_initval = initval;
2142 		to.to_maxval = initval;
2143 		memcpy(&transport->tcp_timeout, &to,
2144 				sizeof(transport->tcp_timeout));
2145 		xprt->timeout = &transport->tcp_timeout;
2146 		xprt->connect_timeout = connect_timeout;
2147 	}
2148 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2149 	spin_unlock(&xprt->transport_lock);
2150 }
2151 
2152 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2153 {
2154 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2155 	int ret = -ENOTCONN;
2156 
2157 	if (!transport->inet) {
2158 		struct sock *sk = sock->sk;
2159 
2160 		/* Avoid temporary address, they are bad for long-lived
2161 		 * connections such as NFS mounts.
2162 		 * RFC4941, section 3.6 suggests that:
2163 		 *    Individual applications, which have specific
2164 		 *    knowledge about the normal duration of connections,
2165 		 *    MAY override this as appropriate.
2166 		 */
2167 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2168 			ip6_sock_set_addr_preferences(sk,
2169 				IPV6_PREFER_SRC_PUBLIC);
2170 		}
2171 
2172 		xs_tcp_set_socket_timeouts(xprt, sock);
2173 		tcp_sock_set_nodelay(sk);
2174 
2175 		write_lock_bh(&sk->sk_callback_lock);
2176 
2177 		xs_save_old_callbacks(transport, sk);
2178 
2179 		sk->sk_user_data = xprt;
2180 		sk->sk_data_ready = xs_data_ready;
2181 		sk->sk_state_change = xs_tcp_state_change;
2182 		sk->sk_write_space = xs_tcp_write_space;
2183 		sock_set_flag(sk, SOCK_FASYNC);
2184 		sk->sk_error_report = xs_error_report;
2185 
2186 		/* socket options */
2187 		sock_reset_flag(sk, SOCK_LINGER);
2188 
2189 		xprt_clear_connected(xprt);
2190 
2191 		/* Reset to new socket */
2192 		transport->sock = sock;
2193 		transport->inet = sk;
2194 
2195 		write_unlock_bh(&sk->sk_callback_lock);
2196 	}
2197 
2198 	if (!xprt_bound(xprt))
2199 		goto out;
2200 
2201 	xs_set_memalloc(xprt);
2202 
2203 	xs_stream_start_connect(transport);
2204 
2205 	/* Tell the socket layer to start connecting... */
2206 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2207 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2208 	switch (ret) {
2209 	case 0:
2210 		xs_set_srcport(transport, sock);
2211 		fallthrough;
2212 	case -EINPROGRESS:
2213 		/* SYN_SENT! */
2214 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2215 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2216 		break;
2217 	case -EADDRNOTAVAIL:
2218 		/* Source port number is unavailable. Try a new one! */
2219 		transport->srcport = 0;
2220 	}
2221 out:
2222 	return ret;
2223 }
2224 
2225 /**
2226  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2227  * @work: queued work item
2228  *
2229  * Invoked by a work queue tasklet.
2230  */
2231 static void xs_tcp_setup_socket(struct work_struct *work)
2232 {
2233 	struct sock_xprt *transport =
2234 		container_of(work, struct sock_xprt, connect_worker.work);
2235 	struct socket *sock = transport->sock;
2236 	struct rpc_xprt *xprt = &transport->xprt;
2237 	int status = -EIO;
2238 
2239 	if (!sock) {
2240 		sock = xs_create_sock(xprt, transport,
2241 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2242 				IPPROTO_TCP, true);
2243 		if (IS_ERR(sock)) {
2244 			status = PTR_ERR(sock);
2245 			goto out;
2246 		}
2247 	}
2248 
2249 	dprintk("RPC:       worker connecting xprt %p via %s to "
2250 				"%s (port %s)\n", xprt,
2251 			xprt->address_strings[RPC_DISPLAY_PROTO],
2252 			xprt->address_strings[RPC_DISPLAY_ADDR],
2253 			xprt->address_strings[RPC_DISPLAY_PORT]);
2254 
2255 	status = xs_tcp_finish_connecting(xprt, sock);
2256 	trace_rpc_socket_connect(xprt, sock, status);
2257 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2258 			xprt, -status, xprt_connected(xprt),
2259 			sock->sk->sk_state);
2260 	switch (status) {
2261 	default:
2262 		printk("%s: connect returned unhandled error %d\n",
2263 			__func__, status);
2264 		fallthrough;
2265 	case -EADDRNOTAVAIL:
2266 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2267 		 * and retry
2268 		 */
2269 		xs_tcp_force_close(xprt);
2270 		break;
2271 	case 0:
2272 	case -EINPROGRESS:
2273 	case -EALREADY:
2274 		xprt_unlock_connect(xprt, transport);
2275 		return;
2276 	case -EINVAL:
2277 		/* Happens, for instance, if the user specified a link
2278 		 * local IPv6 address without a scope-id.
2279 		 */
2280 	case -ECONNREFUSED:
2281 	case -ECONNRESET:
2282 	case -ENETDOWN:
2283 	case -ENETUNREACH:
2284 	case -EHOSTUNREACH:
2285 	case -EADDRINUSE:
2286 	case -ENOBUFS:
2287 		/* xs_tcp_force_close() wakes tasks with a fixed error code.
2288 		 * We need to wake them first to ensure the correct error code.
2289 		 */
2290 		xprt_wake_pending_tasks(xprt, status);
2291 		xs_tcp_force_close(xprt);
2292 		goto out;
2293 	}
2294 	status = -EAGAIN;
2295 out:
2296 	xprt_clear_connecting(xprt);
2297 	xprt_unlock_connect(xprt, transport);
2298 	xprt_wake_pending_tasks(xprt, status);
2299 }
2300 
2301 /**
2302  * xs_connect - connect a socket to a remote endpoint
2303  * @xprt: pointer to transport structure
2304  * @task: address of RPC task that manages state of connect request
2305  *
2306  * TCP: If the remote end dropped the connection, delay reconnecting.
2307  *
2308  * UDP socket connects are synchronous, but we use a work queue anyway
2309  * to guarantee that even unprivileged user processes can set up a
2310  * socket on a privileged port.
2311  *
2312  * If a UDP socket connect fails, the delay behavior here prevents
2313  * retry floods (hard mounts).
2314  */
2315 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2316 {
2317 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2318 	unsigned long delay = 0;
2319 
2320 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2321 
2322 	if (transport->sock != NULL) {
2323 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2324 				"seconds\n",
2325 				xprt, xprt->reestablish_timeout / HZ);
2326 
2327 		/* Start by resetting any existing state */
2328 		xs_reset_transport(transport);
2329 
2330 		delay = xprt_reconnect_delay(xprt);
2331 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2332 
2333 	} else
2334 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2335 
2336 	queue_delayed_work(xprtiod_workqueue,
2337 			&transport->connect_worker,
2338 			delay);
2339 }
2340 
2341 static void xs_wake_disconnect(struct sock_xprt *transport)
2342 {
2343 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2344 		xs_tcp_force_close(&transport->xprt);
2345 }
2346 
2347 static void xs_wake_write(struct sock_xprt *transport)
2348 {
2349 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2350 		xprt_write_space(&transport->xprt);
2351 }
2352 
2353 static void xs_wake_error(struct sock_xprt *transport)
2354 {
2355 	int sockerr;
2356 
2357 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2358 		return;
2359 	mutex_lock(&transport->recv_mutex);
2360 	if (transport->sock == NULL)
2361 		goto out;
2362 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2363 		goto out;
2364 	sockerr = xchg(&transport->xprt_err, 0);
2365 	if (sockerr < 0)
2366 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2367 out:
2368 	mutex_unlock(&transport->recv_mutex);
2369 }
2370 
2371 static void xs_wake_pending(struct sock_xprt *transport)
2372 {
2373 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2374 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2375 }
2376 
2377 static void xs_error_handle(struct work_struct *work)
2378 {
2379 	struct sock_xprt *transport = container_of(work,
2380 			struct sock_xprt, error_worker);
2381 
2382 	xs_wake_disconnect(transport);
2383 	xs_wake_write(transport);
2384 	xs_wake_error(transport);
2385 	xs_wake_pending(transport);
2386 }
2387 
2388 /**
2389  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2390  * @xprt: rpc_xprt struct containing statistics
2391  * @seq: output file
2392  *
2393  */
2394 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2395 {
2396 	long idle_time = 0;
2397 
2398 	if (xprt_connected(xprt))
2399 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2400 
2401 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2402 			"%llu %llu %lu %llu %llu\n",
2403 			xprt->stat.bind_count,
2404 			xprt->stat.connect_count,
2405 			xprt->stat.connect_time / HZ,
2406 			idle_time,
2407 			xprt->stat.sends,
2408 			xprt->stat.recvs,
2409 			xprt->stat.bad_xids,
2410 			xprt->stat.req_u,
2411 			xprt->stat.bklog_u,
2412 			xprt->stat.max_slots,
2413 			xprt->stat.sending_u,
2414 			xprt->stat.pending_u);
2415 }
2416 
2417 /**
2418  * xs_udp_print_stats - display UDP socket-specific stats
2419  * @xprt: rpc_xprt struct containing statistics
2420  * @seq: output file
2421  *
2422  */
2423 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2424 {
2425 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2426 
2427 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2428 			"%lu %llu %llu\n",
2429 			transport->srcport,
2430 			xprt->stat.bind_count,
2431 			xprt->stat.sends,
2432 			xprt->stat.recvs,
2433 			xprt->stat.bad_xids,
2434 			xprt->stat.req_u,
2435 			xprt->stat.bklog_u,
2436 			xprt->stat.max_slots,
2437 			xprt->stat.sending_u,
2438 			xprt->stat.pending_u);
2439 }
2440 
2441 /**
2442  * xs_tcp_print_stats - display TCP socket-specific stats
2443  * @xprt: rpc_xprt struct containing statistics
2444  * @seq: output file
2445  *
2446  */
2447 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2448 {
2449 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2450 	long idle_time = 0;
2451 
2452 	if (xprt_connected(xprt))
2453 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2454 
2455 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2456 			"%llu %llu %lu %llu %llu\n",
2457 			transport->srcport,
2458 			xprt->stat.bind_count,
2459 			xprt->stat.connect_count,
2460 			xprt->stat.connect_time / HZ,
2461 			idle_time,
2462 			xprt->stat.sends,
2463 			xprt->stat.recvs,
2464 			xprt->stat.bad_xids,
2465 			xprt->stat.req_u,
2466 			xprt->stat.bklog_u,
2467 			xprt->stat.max_slots,
2468 			xprt->stat.sending_u,
2469 			xprt->stat.pending_u);
2470 }
2471 
2472 /*
2473  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2474  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2475  * to use the server side send routines.
2476  */
2477 static int bc_malloc(struct rpc_task *task)
2478 {
2479 	struct rpc_rqst *rqst = task->tk_rqstp;
2480 	size_t size = rqst->rq_callsize;
2481 	struct page *page;
2482 	struct rpc_buffer *buf;
2483 
2484 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2485 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2486 			  size);
2487 		return -EINVAL;
2488 	}
2489 
2490 	page = alloc_page(GFP_KERNEL);
2491 	if (!page)
2492 		return -ENOMEM;
2493 
2494 	buf = page_address(page);
2495 	buf->len = PAGE_SIZE;
2496 
2497 	rqst->rq_buffer = buf->data;
2498 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2499 	return 0;
2500 }
2501 
2502 /*
2503  * Free the space allocated in the bc_alloc routine
2504  */
2505 static void bc_free(struct rpc_task *task)
2506 {
2507 	void *buffer = task->tk_rqstp->rq_buffer;
2508 	struct rpc_buffer *buf;
2509 
2510 	buf = container_of(buffer, struct rpc_buffer, data);
2511 	free_page((unsigned long)buf);
2512 }
2513 
2514 static int bc_sendto(struct rpc_rqst *req)
2515 {
2516 	struct xdr_buf *xdr = &req->rq_snd_buf;
2517 	struct sock_xprt *transport =
2518 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2519 	struct msghdr msg = {
2520 		.msg_flags	= 0,
2521 	};
2522 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2523 					 (u32)xdr->len);
2524 	unsigned int sent = 0;
2525 	int err;
2526 
2527 	req->rq_xtime = ktime_get();
2528 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2529 	xdr_free_bvec(xdr);
2530 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2531 		return -EAGAIN;
2532 	return sent;
2533 }
2534 
2535 /**
2536  * bc_send_request - Send a backchannel Call on a TCP socket
2537  * @req: rpc_rqst containing Call message to be sent
2538  *
2539  * xpt_mutex ensures @rqstp's whole message is written to the socket
2540  * without interruption.
2541  *
2542  * Return values:
2543  *   %0 if the message was sent successfully
2544  *   %ENOTCONN if the message was not sent
2545  */
2546 static int bc_send_request(struct rpc_rqst *req)
2547 {
2548 	struct svc_xprt	*xprt;
2549 	int len;
2550 
2551 	/*
2552 	 * Get the server socket associated with this callback xprt
2553 	 */
2554 	xprt = req->rq_xprt->bc_xprt;
2555 
2556 	/*
2557 	 * Grab the mutex to serialize data as the connection is shared
2558 	 * with the fore channel
2559 	 */
2560 	mutex_lock(&xprt->xpt_mutex);
2561 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2562 		len = -ENOTCONN;
2563 	else
2564 		len = bc_sendto(req);
2565 	mutex_unlock(&xprt->xpt_mutex);
2566 
2567 	if (len > 0)
2568 		len = 0;
2569 
2570 	return len;
2571 }
2572 
2573 /*
2574  * The close routine. Since this is client initiated, we do nothing
2575  */
2576 
2577 static void bc_close(struct rpc_xprt *xprt)
2578 {
2579 	xprt_disconnect_done(xprt);
2580 }
2581 
2582 /*
2583  * The xprt destroy routine. Again, because this connection is client
2584  * initiated, we do nothing
2585  */
2586 
2587 static void bc_destroy(struct rpc_xprt *xprt)
2588 {
2589 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2590 
2591 	xs_xprt_free(xprt);
2592 	module_put(THIS_MODULE);
2593 }
2594 
2595 static const struct rpc_xprt_ops xs_local_ops = {
2596 	.reserve_xprt		= xprt_reserve_xprt,
2597 	.release_xprt		= xprt_release_xprt,
2598 	.alloc_slot		= xprt_alloc_slot,
2599 	.free_slot		= xprt_free_slot,
2600 	.rpcbind		= xs_local_rpcbind,
2601 	.set_port		= xs_local_set_port,
2602 	.connect		= xs_local_connect,
2603 	.buf_alloc		= rpc_malloc,
2604 	.buf_free		= rpc_free,
2605 	.prepare_request	= xs_stream_prepare_request,
2606 	.send_request		= xs_local_send_request,
2607 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2608 	.close			= xs_close,
2609 	.destroy		= xs_destroy,
2610 	.print_stats		= xs_local_print_stats,
2611 	.enable_swap		= xs_enable_swap,
2612 	.disable_swap		= xs_disable_swap,
2613 };
2614 
2615 static const struct rpc_xprt_ops xs_udp_ops = {
2616 	.set_buffer_size	= xs_udp_set_buffer_size,
2617 	.reserve_xprt		= xprt_reserve_xprt_cong,
2618 	.release_xprt		= xprt_release_xprt_cong,
2619 	.alloc_slot		= xprt_alloc_slot,
2620 	.free_slot		= xprt_free_slot,
2621 	.rpcbind		= rpcb_getport_async,
2622 	.set_port		= xs_set_port,
2623 	.connect		= xs_connect,
2624 	.buf_alloc		= rpc_malloc,
2625 	.buf_free		= rpc_free,
2626 	.send_request		= xs_udp_send_request,
2627 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2628 	.timer			= xs_udp_timer,
2629 	.release_request	= xprt_release_rqst_cong,
2630 	.close			= xs_close,
2631 	.destroy		= xs_destroy,
2632 	.print_stats		= xs_udp_print_stats,
2633 	.enable_swap		= xs_enable_swap,
2634 	.disable_swap		= xs_disable_swap,
2635 	.inject_disconnect	= xs_inject_disconnect,
2636 };
2637 
2638 static const struct rpc_xprt_ops xs_tcp_ops = {
2639 	.reserve_xprt		= xprt_reserve_xprt,
2640 	.release_xprt		= xprt_release_xprt,
2641 	.alloc_slot		= xprt_alloc_slot,
2642 	.free_slot		= xprt_free_slot,
2643 	.rpcbind		= rpcb_getport_async,
2644 	.set_port		= xs_set_port,
2645 	.connect		= xs_connect,
2646 	.buf_alloc		= rpc_malloc,
2647 	.buf_free		= rpc_free,
2648 	.prepare_request	= xs_stream_prepare_request,
2649 	.send_request		= xs_tcp_send_request,
2650 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2651 	.close			= xs_tcp_shutdown,
2652 	.destroy		= xs_destroy,
2653 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2654 	.print_stats		= xs_tcp_print_stats,
2655 	.enable_swap		= xs_enable_swap,
2656 	.disable_swap		= xs_disable_swap,
2657 	.inject_disconnect	= xs_inject_disconnect,
2658 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2659 	.bc_setup		= xprt_setup_bc,
2660 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2661 	.bc_num_slots		= xprt_bc_max_slots,
2662 	.bc_free_rqst		= xprt_free_bc_rqst,
2663 	.bc_destroy		= xprt_destroy_bc,
2664 #endif
2665 };
2666 
2667 /*
2668  * The rpc_xprt_ops for the server backchannel
2669  */
2670 
2671 static const struct rpc_xprt_ops bc_tcp_ops = {
2672 	.reserve_xprt		= xprt_reserve_xprt,
2673 	.release_xprt		= xprt_release_xprt,
2674 	.alloc_slot		= xprt_alloc_slot,
2675 	.free_slot		= xprt_free_slot,
2676 	.buf_alloc		= bc_malloc,
2677 	.buf_free		= bc_free,
2678 	.send_request		= bc_send_request,
2679 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2680 	.close			= bc_close,
2681 	.destroy		= bc_destroy,
2682 	.print_stats		= xs_tcp_print_stats,
2683 	.enable_swap		= xs_enable_swap,
2684 	.disable_swap		= xs_disable_swap,
2685 	.inject_disconnect	= xs_inject_disconnect,
2686 };
2687 
2688 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2689 {
2690 	static const struct sockaddr_in sin = {
2691 		.sin_family		= AF_INET,
2692 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2693 	};
2694 	static const struct sockaddr_in6 sin6 = {
2695 		.sin6_family		= AF_INET6,
2696 		.sin6_addr		= IN6ADDR_ANY_INIT,
2697 	};
2698 
2699 	switch (family) {
2700 	case AF_LOCAL:
2701 		break;
2702 	case AF_INET:
2703 		memcpy(sap, &sin, sizeof(sin));
2704 		break;
2705 	case AF_INET6:
2706 		memcpy(sap, &sin6, sizeof(sin6));
2707 		break;
2708 	default:
2709 		dprintk("RPC:       %s: Bad address family\n", __func__);
2710 		return -EAFNOSUPPORT;
2711 	}
2712 	return 0;
2713 }
2714 
2715 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2716 				      unsigned int slot_table_size,
2717 				      unsigned int max_slot_table_size)
2718 {
2719 	struct rpc_xprt *xprt;
2720 	struct sock_xprt *new;
2721 
2722 	if (args->addrlen > sizeof(xprt->addr)) {
2723 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2724 		return ERR_PTR(-EBADF);
2725 	}
2726 
2727 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2728 			max_slot_table_size);
2729 	if (xprt == NULL) {
2730 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2731 				"rpc_xprt\n");
2732 		return ERR_PTR(-ENOMEM);
2733 	}
2734 
2735 	new = container_of(xprt, struct sock_xprt, xprt);
2736 	mutex_init(&new->recv_mutex);
2737 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2738 	xprt->addrlen = args->addrlen;
2739 	if (args->srcaddr)
2740 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2741 	else {
2742 		int err;
2743 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2744 					(struct sockaddr *)&new->srcaddr);
2745 		if (err != 0) {
2746 			xprt_free(xprt);
2747 			return ERR_PTR(err);
2748 		}
2749 	}
2750 
2751 	return xprt;
2752 }
2753 
2754 static const struct rpc_timeout xs_local_default_timeout = {
2755 	.to_initval = 10 * HZ,
2756 	.to_maxval = 10 * HZ,
2757 	.to_retries = 2,
2758 };
2759 
2760 /**
2761  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2762  * @args: rpc transport creation arguments
2763  *
2764  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2765  */
2766 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2767 {
2768 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2769 	struct sock_xprt *transport;
2770 	struct rpc_xprt *xprt;
2771 	struct rpc_xprt *ret;
2772 
2773 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2774 			xprt_max_tcp_slot_table_entries);
2775 	if (IS_ERR(xprt))
2776 		return xprt;
2777 	transport = container_of(xprt, struct sock_xprt, xprt);
2778 
2779 	xprt->prot = 0;
2780 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2781 
2782 	xprt->bind_timeout = XS_BIND_TO;
2783 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2784 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2785 
2786 	xprt->ops = &xs_local_ops;
2787 	xprt->timeout = &xs_local_default_timeout;
2788 
2789 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2790 	INIT_WORK(&transport->error_worker, xs_error_handle);
2791 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2792 
2793 	switch (sun->sun_family) {
2794 	case AF_LOCAL:
2795 		if (sun->sun_path[0] != '/') {
2796 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2797 					sun->sun_path);
2798 			ret = ERR_PTR(-EINVAL);
2799 			goto out_err;
2800 		}
2801 		xprt_set_bound(xprt);
2802 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2803 		ret = ERR_PTR(xs_local_setup_socket(transport));
2804 		if (ret)
2805 			goto out_err;
2806 		break;
2807 	default:
2808 		ret = ERR_PTR(-EAFNOSUPPORT);
2809 		goto out_err;
2810 	}
2811 
2812 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2813 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2814 
2815 	if (try_module_get(THIS_MODULE))
2816 		return xprt;
2817 	ret = ERR_PTR(-EINVAL);
2818 out_err:
2819 	xs_xprt_free(xprt);
2820 	return ret;
2821 }
2822 
2823 static const struct rpc_timeout xs_udp_default_timeout = {
2824 	.to_initval = 5 * HZ,
2825 	.to_maxval = 30 * HZ,
2826 	.to_increment = 5 * HZ,
2827 	.to_retries = 5,
2828 };
2829 
2830 /**
2831  * xs_setup_udp - Set up transport to use a UDP socket
2832  * @args: rpc transport creation arguments
2833  *
2834  */
2835 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2836 {
2837 	struct sockaddr *addr = args->dstaddr;
2838 	struct rpc_xprt *xprt;
2839 	struct sock_xprt *transport;
2840 	struct rpc_xprt *ret;
2841 
2842 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2843 			xprt_udp_slot_table_entries);
2844 	if (IS_ERR(xprt))
2845 		return xprt;
2846 	transport = container_of(xprt, struct sock_xprt, xprt);
2847 
2848 	xprt->prot = IPPROTO_UDP;
2849 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2850 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2851 
2852 	xprt->bind_timeout = XS_BIND_TO;
2853 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2854 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2855 
2856 	xprt->ops = &xs_udp_ops;
2857 
2858 	xprt->timeout = &xs_udp_default_timeout;
2859 
2860 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2861 	INIT_WORK(&transport->error_worker, xs_error_handle);
2862 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2863 
2864 	switch (addr->sa_family) {
2865 	case AF_INET:
2866 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2867 			xprt_set_bound(xprt);
2868 
2869 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2870 		break;
2871 	case AF_INET6:
2872 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2873 			xprt_set_bound(xprt);
2874 
2875 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2876 		break;
2877 	default:
2878 		ret = ERR_PTR(-EAFNOSUPPORT);
2879 		goto out_err;
2880 	}
2881 
2882 	if (xprt_bound(xprt))
2883 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2884 				xprt->address_strings[RPC_DISPLAY_ADDR],
2885 				xprt->address_strings[RPC_DISPLAY_PORT],
2886 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2887 	else
2888 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2889 				xprt->address_strings[RPC_DISPLAY_ADDR],
2890 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2891 
2892 	if (try_module_get(THIS_MODULE))
2893 		return xprt;
2894 	ret = ERR_PTR(-EINVAL);
2895 out_err:
2896 	xs_xprt_free(xprt);
2897 	return ret;
2898 }
2899 
2900 static const struct rpc_timeout xs_tcp_default_timeout = {
2901 	.to_initval = 60 * HZ,
2902 	.to_maxval = 60 * HZ,
2903 	.to_retries = 2,
2904 };
2905 
2906 /**
2907  * xs_setup_tcp - Set up transport to use a TCP socket
2908  * @args: rpc transport creation arguments
2909  *
2910  */
2911 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2912 {
2913 	struct sockaddr *addr = args->dstaddr;
2914 	struct rpc_xprt *xprt;
2915 	struct sock_xprt *transport;
2916 	struct rpc_xprt *ret;
2917 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2918 
2919 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2920 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2921 
2922 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2923 			max_slot_table_size);
2924 	if (IS_ERR(xprt))
2925 		return xprt;
2926 	transport = container_of(xprt, struct sock_xprt, xprt);
2927 
2928 	xprt->prot = IPPROTO_TCP;
2929 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2930 
2931 	xprt->bind_timeout = XS_BIND_TO;
2932 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2933 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2934 
2935 	xprt->ops = &xs_tcp_ops;
2936 	xprt->timeout = &xs_tcp_default_timeout;
2937 
2938 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2939 	xprt->connect_timeout = xprt->timeout->to_initval *
2940 		(xprt->timeout->to_retries + 1);
2941 
2942 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2943 	INIT_WORK(&transport->error_worker, xs_error_handle);
2944 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2945 
2946 	switch (addr->sa_family) {
2947 	case AF_INET:
2948 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2949 			xprt_set_bound(xprt);
2950 
2951 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2952 		break;
2953 	case AF_INET6:
2954 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2955 			xprt_set_bound(xprt);
2956 
2957 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2958 		break;
2959 	default:
2960 		ret = ERR_PTR(-EAFNOSUPPORT);
2961 		goto out_err;
2962 	}
2963 
2964 	if (xprt_bound(xprt))
2965 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2966 				xprt->address_strings[RPC_DISPLAY_ADDR],
2967 				xprt->address_strings[RPC_DISPLAY_PORT],
2968 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2969 	else
2970 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2971 				xprt->address_strings[RPC_DISPLAY_ADDR],
2972 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2973 
2974 	if (try_module_get(THIS_MODULE))
2975 		return xprt;
2976 	ret = ERR_PTR(-EINVAL);
2977 out_err:
2978 	xs_xprt_free(xprt);
2979 	return ret;
2980 }
2981 
2982 /**
2983  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2984  * @args: rpc transport creation arguments
2985  *
2986  */
2987 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2988 {
2989 	struct sockaddr *addr = args->dstaddr;
2990 	struct rpc_xprt *xprt;
2991 	struct sock_xprt *transport;
2992 	struct svc_sock *bc_sock;
2993 	struct rpc_xprt *ret;
2994 
2995 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2996 			xprt_tcp_slot_table_entries);
2997 	if (IS_ERR(xprt))
2998 		return xprt;
2999 	transport = container_of(xprt, struct sock_xprt, xprt);
3000 
3001 	xprt->prot = IPPROTO_TCP;
3002 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3003 	xprt->timeout = &xs_tcp_default_timeout;
3004 
3005 	/* backchannel */
3006 	xprt_set_bound(xprt);
3007 	xprt->bind_timeout = 0;
3008 	xprt->reestablish_timeout = 0;
3009 	xprt->idle_timeout = 0;
3010 
3011 	xprt->ops = &bc_tcp_ops;
3012 
3013 	switch (addr->sa_family) {
3014 	case AF_INET:
3015 		xs_format_peer_addresses(xprt, "tcp",
3016 					 RPCBIND_NETID_TCP);
3017 		break;
3018 	case AF_INET6:
3019 		xs_format_peer_addresses(xprt, "tcp",
3020 				   RPCBIND_NETID_TCP6);
3021 		break;
3022 	default:
3023 		ret = ERR_PTR(-EAFNOSUPPORT);
3024 		goto out_err;
3025 	}
3026 
3027 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3028 			xprt->address_strings[RPC_DISPLAY_ADDR],
3029 			xprt->address_strings[RPC_DISPLAY_PORT],
3030 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3031 
3032 	/*
3033 	 * Once we've associated a backchannel xprt with a connection,
3034 	 * we want to keep it around as long as the connection lasts,
3035 	 * in case we need to start using it for a backchannel again;
3036 	 * this reference won't be dropped until bc_xprt is destroyed.
3037 	 */
3038 	xprt_get(xprt);
3039 	args->bc_xprt->xpt_bc_xprt = xprt;
3040 	xprt->bc_xprt = args->bc_xprt;
3041 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3042 	transport->sock = bc_sock->sk_sock;
3043 	transport->inet = bc_sock->sk_sk;
3044 
3045 	/*
3046 	 * Since we don't want connections for the backchannel, we set
3047 	 * the xprt status to connected
3048 	 */
3049 	xprt_set_connected(xprt);
3050 
3051 	if (try_module_get(THIS_MODULE))
3052 		return xprt;
3053 
3054 	args->bc_xprt->xpt_bc_xprt = NULL;
3055 	args->bc_xprt->xpt_bc_xps = NULL;
3056 	xprt_put(xprt);
3057 	ret = ERR_PTR(-EINVAL);
3058 out_err:
3059 	xs_xprt_free(xprt);
3060 	return ret;
3061 }
3062 
3063 static struct xprt_class	xs_local_transport = {
3064 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3065 	.name		= "named UNIX socket",
3066 	.owner		= THIS_MODULE,
3067 	.ident		= XPRT_TRANSPORT_LOCAL,
3068 	.setup		= xs_setup_local,
3069 	.netid		= { "" },
3070 };
3071 
3072 static struct xprt_class	xs_udp_transport = {
3073 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3074 	.name		= "udp",
3075 	.owner		= THIS_MODULE,
3076 	.ident		= XPRT_TRANSPORT_UDP,
3077 	.setup		= xs_setup_udp,
3078 	.netid		= { "udp", "udp6", "" },
3079 };
3080 
3081 static struct xprt_class	xs_tcp_transport = {
3082 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3083 	.name		= "tcp",
3084 	.owner		= THIS_MODULE,
3085 	.ident		= XPRT_TRANSPORT_TCP,
3086 	.setup		= xs_setup_tcp,
3087 	.netid		= { "tcp", "tcp6", "" },
3088 };
3089 
3090 static struct xprt_class	xs_bc_tcp_transport = {
3091 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3092 	.name		= "tcp NFSv4.1 backchannel",
3093 	.owner		= THIS_MODULE,
3094 	.ident		= XPRT_TRANSPORT_BC_TCP,
3095 	.setup		= xs_setup_bc_tcp,
3096 	.netid		= { "" },
3097 };
3098 
3099 /**
3100  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3101  *
3102  */
3103 int init_socket_xprt(void)
3104 {
3105 	if (!sunrpc_table_header)
3106 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3107 
3108 	xprt_register_transport(&xs_local_transport);
3109 	xprt_register_transport(&xs_udp_transport);
3110 	xprt_register_transport(&xs_tcp_transport);
3111 	xprt_register_transport(&xs_bc_tcp_transport);
3112 
3113 	return 0;
3114 }
3115 
3116 /**
3117  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3118  *
3119  */
3120 void cleanup_socket_xprt(void)
3121 {
3122 	if (sunrpc_table_header) {
3123 		unregister_sysctl_table(sunrpc_table_header);
3124 		sunrpc_table_header = NULL;
3125 	}
3126 
3127 	xprt_unregister_transport(&xs_local_transport);
3128 	xprt_unregister_transport(&xs_udp_transport);
3129 	xprt_unregister_transport(&xs_tcp_transport);
3130 	xprt_unregister_transport(&xs_bc_tcp_transport);
3131 }
3132 
3133 static int param_set_uint_minmax(const char *val,
3134 		const struct kernel_param *kp,
3135 		unsigned int min, unsigned int max)
3136 {
3137 	unsigned int num;
3138 	int ret;
3139 
3140 	if (!val)
3141 		return -EINVAL;
3142 	ret = kstrtouint(val, 0, &num);
3143 	if (ret)
3144 		return ret;
3145 	if (num < min || num > max)
3146 		return -EINVAL;
3147 	*((unsigned int *)kp->arg) = num;
3148 	return 0;
3149 }
3150 
3151 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3152 {
3153 	return param_set_uint_minmax(val, kp,
3154 			RPC_MIN_RESVPORT,
3155 			RPC_MAX_RESVPORT);
3156 }
3157 
3158 static const struct kernel_param_ops param_ops_portnr = {
3159 	.set = param_set_portnr,
3160 	.get = param_get_uint,
3161 };
3162 
3163 #define param_check_portnr(name, p) \
3164 	__param_check(name, p, unsigned int);
3165 
3166 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3167 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3168 
3169 static int param_set_slot_table_size(const char *val,
3170 				     const struct kernel_param *kp)
3171 {
3172 	return param_set_uint_minmax(val, kp,
3173 			RPC_MIN_SLOT_TABLE,
3174 			RPC_MAX_SLOT_TABLE);
3175 }
3176 
3177 static const struct kernel_param_ops param_ops_slot_table_size = {
3178 	.set = param_set_slot_table_size,
3179 	.get = param_get_uint,
3180 };
3181 
3182 #define param_check_slot_table_size(name, p) \
3183 	__param_check(name, p, unsigned int);
3184 
3185 static int param_set_max_slot_table_size(const char *val,
3186 				     const struct kernel_param *kp)
3187 {
3188 	return param_set_uint_minmax(val, kp,
3189 			RPC_MIN_SLOT_TABLE,
3190 			RPC_MAX_SLOT_TABLE_LIMIT);
3191 }
3192 
3193 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3194 	.set = param_set_max_slot_table_size,
3195 	.get = param_get_uint,
3196 };
3197 
3198 #define param_check_max_slot_table_size(name, p) \
3199 	__param_check(name, p, unsigned int);
3200 
3201 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3202 		   slot_table_size, 0644);
3203 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3204 		   max_slot_table_size, 0644);
3205 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3206 		   slot_table_size, 0644);
3207