xref: /linux/net/sunrpc/xprtsock.c (revision 19f2e267a5d0d26282a64f8f788c482852c95324)
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/uio.h>
52 
53 #include <trace/events/sunrpc.h>
54 
55 #include "sunrpc.h"
56 
57 static void xs_close(struct rpc_xprt *xprt);
58 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
59 		struct socket *sock);
60 
61 /*
62  * xprtsock tunables
63  */
64 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
65 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
66 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
67 
68 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
69 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
70 
71 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
72 
73 #define XS_TCP_LINGER_TO	(15U * HZ)
74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
75 
76 /*
77  * We can register our own files under /proc/sys/sunrpc by
78  * calling register_sysctl_table() again.  The files in that
79  * directory become the union of all files registered there.
80  *
81  * We simply need to make sure that we don't collide with
82  * someone else's file names!
83  */
84 
85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
90 
91 static struct ctl_table_header *sunrpc_table_header;
92 
93 /*
94  * FIXME: changing the UDP slot table size should also resize the UDP
95  *        socket buffers for existing UDP transports
96  */
97 static struct ctl_table xs_tunables_table[] = {
98 	{
99 		.procname	= "udp_slot_table_entries",
100 		.data		= &xprt_udp_slot_table_entries,
101 		.maxlen		= sizeof(unsigned int),
102 		.mode		= 0644,
103 		.proc_handler	= proc_dointvec_minmax,
104 		.extra1		= &min_slot_table_size,
105 		.extra2		= &max_slot_table_size
106 	},
107 	{
108 		.procname	= "tcp_slot_table_entries",
109 		.data		= &xprt_tcp_slot_table_entries,
110 		.maxlen		= sizeof(unsigned int),
111 		.mode		= 0644,
112 		.proc_handler	= proc_dointvec_minmax,
113 		.extra1		= &min_slot_table_size,
114 		.extra2		= &max_slot_table_size
115 	},
116 	{
117 		.procname	= "tcp_max_slot_table_entries",
118 		.data		= &xprt_max_tcp_slot_table_entries,
119 		.maxlen		= sizeof(unsigned int),
120 		.mode		= 0644,
121 		.proc_handler	= proc_dointvec_minmax,
122 		.extra1		= &min_slot_table_size,
123 		.extra2		= &max_tcp_slot_table_limit
124 	},
125 	{
126 		.procname	= "min_resvport",
127 		.data		= &xprt_min_resvport,
128 		.maxlen		= sizeof(unsigned int),
129 		.mode		= 0644,
130 		.proc_handler	= proc_dointvec_minmax,
131 		.extra1		= &xprt_min_resvport_limit,
132 		.extra2		= &xprt_max_resvport_limit
133 	},
134 	{
135 		.procname	= "max_resvport",
136 		.data		= &xprt_max_resvport,
137 		.maxlen		= sizeof(unsigned int),
138 		.mode		= 0644,
139 		.proc_handler	= proc_dointvec_minmax,
140 		.extra1		= &xprt_min_resvport_limit,
141 		.extra2		= &xprt_max_resvport_limit
142 	},
143 	{
144 		.procname	= "tcp_fin_timeout",
145 		.data		= &xs_tcp_fin_timeout,
146 		.maxlen		= sizeof(xs_tcp_fin_timeout),
147 		.mode		= 0644,
148 		.proc_handler	= proc_dointvec_jiffies,
149 	},
150 	{ },
151 };
152 
153 static struct ctl_table sunrpc_table[] = {
154 	{
155 		.procname	= "sunrpc",
156 		.mode		= 0555,
157 		.child		= xs_tunables_table
158 	},
159 	{ },
160 };
161 
162 #endif
163 
164 /*
165  * Wait duration for a reply from the RPC portmapper.
166  */
167 #define XS_BIND_TO		(60U * HZ)
168 
169 /*
170  * Delay if a UDP socket connect error occurs.  This is most likely some
171  * kind of resource problem on the local host.
172  */
173 #define XS_UDP_REEST_TO		(2U * HZ)
174 
175 /*
176  * The reestablish timeout allows clients to delay for a bit before attempting
177  * to reconnect to a server that just dropped our connection.
178  *
179  * We implement an exponential backoff when trying to reestablish a TCP
180  * transport connection with the server.  Some servers like to drop a TCP
181  * connection when they are overworked, so we start with a short timeout and
182  * increase over time if the server is down or not responding.
183  */
184 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
185 
186 /*
187  * TCP idle timeout; client drops the transport socket if it is idle
188  * for this long.  Note that we also timeout UDP sockets to prevent
189  * holding port numbers when there is no RPC traffic.
190  */
191 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
192 
193 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
194 # undef  RPC_DEBUG_DATA
195 # define RPCDBG_FACILITY	RPCDBG_TRANS
196 #endif
197 
198 #ifdef RPC_DEBUG_DATA
199 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
200 {
201 	u8 *buf = (u8 *) packet;
202 	int j;
203 
204 	dprintk("RPC:       %s\n", msg);
205 	for (j = 0; j < count && j < 128; j += 4) {
206 		if (!(j & 31)) {
207 			if (j)
208 				dprintk("\n");
209 			dprintk("0x%04x ", j);
210 		}
211 		dprintk("%02x%02x%02x%02x ",
212 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
213 	}
214 	dprintk("\n");
215 }
216 #else
217 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
218 {
219 	/* NOP */
220 }
221 #endif
222 
223 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
224 {
225 	return (struct rpc_xprt *) sk->sk_user_data;
226 }
227 
228 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
229 {
230 	return (struct sockaddr *) &xprt->addr;
231 }
232 
233 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr_un *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_in *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in6 *) &xprt->addr;
246 }
247 
248 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
249 {
250 	struct sockaddr *sap = xs_addr(xprt);
251 	struct sockaddr_in6 *sin6;
252 	struct sockaddr_in *sin;
253 	struct sockaddr_un *sun;
254 	char buf[128];
255 
256 	switch (sap->sa_family) {
257 	case AF_LOCAL:
258 		sun = xs_addr_un(xprt);
259 		strlcpy(buf, sun->sun_path, sizeof(buf));
260 		xprt->address_strings[RPC_DISPLAY_ADDR] =
261 						kstrdup(buf, GFP_KERNEL);
262 		break;
263 	case AF_INET:
264 		(void)rpc_ntop(sap, buf, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		sin = xs_addr_in(xprt);
268 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
269 		break;
270 	case AF_INET6:
271 		(void)rpc_ntop(sap, buf, sizeof(buf));
272 		xprt->address_strings[RPC_DISPLAY_ADDR] =
273 						kstrdup(buf, GFP_KERNEL);
274 		sin6 = xs_addr_in6(xprt);
275 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
276 		break;
277 	default:
278 		BUG();
279 	}
280 
281 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
282 }
283 
284 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
285 {
286 	struct sockaddr *sap = xs_addr(xprt);
287 	char buf[128];
288 
289 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
290 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
291 
292 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
293 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
294 }
295 
296 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
297 				     const char *protocol,
298 				     const char *netid)
299 {
300 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
301 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
302 	xs_format_common_peer_addresses(xprt);
303 	xs_format_common_peer_ports(xprt);
304 }
305 
306 static void xs_update_peer_port(struct rpc_xprt *xprt)
307 {
308 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
309 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
310 
311 	xs_format_common_peer_ports(xprt);
312 }
313 
314 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
315 {
316 	unsigned int i;
317 
318 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
319 		switch (i) {
320 		case RPC_DISPLAY_PROTO:
321 		case RPC_DISPLAY_NETID:
322 			continue;
323 		default:
324 			kfree(xprt->address_strings[i]);
325 		}
326 }
327 
328 static size_t
329 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
330 {
331 	size_t i,n;
332 
333 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
334 		return want;
335 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
336 	for (i = 0; i < n; i++) {
337 		if (buf->pages[i])
338 			continue;
339 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
340 		if (!buf->pages[i]) {
341 			i *= PAGE_SIZE;
342 			return i > buf->page_base ? i - buf->page_base : 0;
343 		}
344 	}
345 	return want;
346 }
347 
348 static ssize_t
349 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
350 {
351 	ssize_t ret;
352 	if (seek != 0)
353 		iov_iter_advance(&msg->msg_iter, seek);
354 	ret = sock_recvmsg(sock, msg, flags);
355 	return ret > 0 ? ret + seek : ret;
356 }
357 
358 static ssize_t
359 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
360 		struct kvec *kvec, size_t count, size_t seek)
361 {
362 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
363 	return xs_sock_recvmsg(sock, msg, flags, seek);
364 }
365 
366 static ssize_t
367 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
368 		struct bio_vec *bvec, unsigned long nr, size_t count,
369 		size_t seek)
370 {
371 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
372 	return xs_sock_recvmsg(sock, msg, flags, seek);
373 }
374 
375 static ssize_t
376 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
377 		size_t count)
378 {
379 	iov_iter_discard(&msg->msg_iter, READ, count);
380 	return sock_recvmsg(sock, msg, flags);
381 }
382 
383 static ssize_t
384 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
385 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
386 {
387 	size_t want, seek_init = seek, offset = 0;
388 	ssize_t ret;
389 
390 	if (seek < buf->head[0].iov_len) {
391 		want = min_t(size_t, count, buf->head[0].iov_len);
392 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
393 		if (ret <= 0)
394 			goto sock_err;
395 		offset += ret;
396 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
397 			goto out;
398 		if (ret != want)
399 			goto out;
400 		seek = 0;
401 	} else {
402 		seek -= buf->head[0].iov_len;
403 		offset += buf->head[0].iov_len;
404 	}
405 
406 	want = xs_alloc_sparse_pages(buf,
407 			min_t(size_t, count - offset, buf->page_len),
408 			GFP_NOWAIT);
409 	if (seek < want) {
410 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
411 				xdr_buf_pagecount(buf),
412 				want + buf->page_base,
413 				seek + buf->page_base);
414 		if (ret <= 0)
415 			goto sock_err;
416 		offset += ret - buf->page_base;
417 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
418 			goto out;
419 		if (ret != want)
420 			goto out;
421 		seek = 0;
422 	} else {
423 		seek -= want;
424 		offset += want;
425 	}
426 
427 	if (seek < buf->tail[0].iov_len) {
428 		want = min_t(size_t, count - offset, buf->tail[0].iov_len);
429 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
430 		if (ret <= 0)
431 			goto sock_err;
432 		offset += ret;
433 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
434 			goto out;
435 		if (ret != want)
436 			goto out;
437 	} else
438 		offset += buf->tail[0].iov_len;
439 	ret = -EMSGSIZE;
440 out:
441 	*read = offset - seek_init;
442 	return ret;
443 sock_err:
444 	offset += seek;
445 	goto out;
446 }
447 
448 static void
449 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
450 {
451 	if (!transport->recv.copied) {
452 		if (buf->head[0].iov_len >= transport->recv.offset)
453 			memcpy(buf->head[0].iov_base,
454 					&transport->recv.xid,
455 					transport->recv.offset);
456 		transport->recv.copied = transport->recv.offset;
457 	}
458 }
459 
460 static bool
461 xs_read_stream_request_done(struct sock_xprt *transport)
462 {
463 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
464 }
465 
466 static ssize_t
467 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
468 		int flags, struct rpc_rqst *req)
469 {
470 	struct xdr_buf *buf = &req->rq_private_buf;
471 	size_t want, read;
472 	ssize_t ret;
473 
474 	xs_read_header(transport, buf);
475 
476 	want = transport->recv.len - transport->recv.offset;
477 	ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
478 			transport->recv.copied + want, transport->recv.copied,
479 			&read);
480 	transport->recv.offset += read;
481 	transport->recv.copied += read;
482 	if (transport->recv.offset == transport->recv.len) {
483 		if (xs_read_stream_request_done(transport))
484 			msg->msg_flags |= MSG_EOR;
485 		return read;
486 	}
487 
488 	switch (ret) {
489 	default:
490 		break;
491 	case -EFAULT:
492 	case -EMSGSIZE:
493 		msg->msg_flags |= MSG_TRUNC;
494 		return read;
495 	case 0:
496 		return -ESHUTDOWN;
497 	}
498 	return ret < 0 ? ret : read;
499 }
500 
501 static size_t
502 xs_read_stream_headersize(bool isfrag)
503 {
504 	if (isfrag)
505 		return sizeof(__be32);
506 	return 3 * sizeof(__be32);
507 }
508 
509 static ssize_t
510 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
511 		int flags, size_t want, size_t seek)
512 {
513 	struct kvec kvec = {
514 		.iov_base = &transport->recv.fraghdr,
515 		.iov_len = want,
516 	};
517 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
518 }
519 
520 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
521 static ssize_t
522 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
523 {
524 	struct rpc_xprt *xprt = &transport->xprt;
525 	struct rpc_rqst *req;
526 	ssize_t ret;
527 
528 	/* Look up and lock the request corresponding to the given XID */
529 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
530 	if (!req) {
531 		printk(KERN_WARNING "Callback slot table overflowed\n");
532 		return -ESHUTDOWN;
533 	}
534 
535 	ret = xs_read_stream_request(transport, msg, flags, req);
536 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
537 		xprt_complete_bc_request(req, transport->recv.copied);
538 
539 	return ret;
540 }
541 #else /* CONFIG_SUNRPC_BACKCHANNEL */
542 static ssize_t
543 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
544 {
545 	return -ESHUTDOWN;
546 }
547 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
548 
549 static ssize_t
550 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
551 {
552 	struct rpc_xprt *xprt = &transport->xprt;
553 	struct rpc_rqst *req;
554 	ssize_t ret = 0;
555 
556 	/* Look up and lock the request corresponding to the given XID */
557 	spin_lock(&xprt->queue_lock);
558 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
559 	if (!req) {
560 		msg->msg_flags |= MSG_TRUNC;
561 		goto out;
562 	}
563 	xprt_pin_rqst(req);
564 	spin_unlock(&xprt->queue_lock);
565 
566 	ret = xs_read_stream_request(transport, msg, flags, req);
567 
568 	spin_lock(&xprt->queue_lock);
569 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
570 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
571 	xprt_unpin_rqst(req);
572 out:
573 	spin_unlock(&xprt->queue_lock);
574 	return ret;
575 }
576 
577 static ssize_t
578 xs_read_stream(struct sock_xprt *transport, int flags)
579 {
580 	struct msghdr msg = { 0 };
581 	size_t want, read = 0;
582 	ssize_t ret = 0;
583 
584 	if (transport->recv.len == 0) {
585 		want = xs_read_stream_headersize(transport->recv.copied != 0);
586 		ret = xs_read_stream_header(transport, &msg, flags, want,
587 				transport->recv.offset);
588 		if (ret <= 0)
589 			goto out_err;
590 		transport->recv.offset = ret;
591 		if (transport->recv.offset != want)
592 			return transport->recv.offset;
593 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
594 			RPC_FRAGMENT_SIZE_MASK;
595 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
596 		read = ret;
597 	}
598 
599 	switch (be32_to_cpu(transport->recv.calldir)) {
600 	default:
601 		msg.msg_flags |= MSG_TRUNC;
602 		break;
603 	case RPC_CALL:
604 		ret = xs_read_stream_call(transport, &msg, flags);
605 		break;
606 	case RPC_REPLY:
607 		ret = xs_read_stream_reply(transport, &msg, flags);
608 	}
609 	if (msg.msg_flags & MSG_TRUNC) {
610 		transport->recv.calldir = cpu_to_be32(-1);
611 		transport->recv.copied = -1;
612 	}
613 	if (ret < 0)
614 		goto out_err;
615 	read += ret;
616 	if (transport->recv.offset < transport->recv.len) {
617 		if (!(msg.msg_flags & MSG_TRUNC))
618 			return read;
619 		msg.msg_flags = 0;
620 		ret = xs_read_discard(transport->sock, &msg, flags,
621 				transport->recv.len - transport->recv.offset);
622 		if (ret <= 0)
623 			goto out_err;
624 		transport->recv.offset += ret;
625 		read += ret;
626 		if (transport->recv.offset != transport->recv.len)
627 			return read;
628 	}
629 	if (xs_read_stream_request_done(transport)) {
630 		trace_xs_stream_read_request(transport);
631 		transport->recv.copied = 0;
632 	}
633 	transport->recv.offset = 0;
634 	transport->recv.len = 0;
635 	return read;
636 out_err:
637 	return ret != 0 ? ret : -ESHUTDOWN;
638 }
639 
640 static void xs_stream_data_receive(struct sock_xprt *transport)
641 {
642 	size_t read = 0;
643 	ssize_t ret = 0;
644 
645 	mutex_lock(&transport->recv_mutex);
646 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
647 	if (transport->sock == NULL)
648 		goto out;
649 	for (;;) {
650 		ret = xs_read_stream(transport, MSG_DONTWAIT);
651 		if (ret < 0)
652 			break;
653 		read += ret;
654 		cond_resched();
655 	}
656 out:
657 	mutex_unlock(&transport->recv_mutex);
658 	trace_xs_stream_read_data(&transport->xprt, ret, read);
659 }
660 
661 static void xs_stream_data_receive_workfn(struct work_struct *work)
662 {
663 	struct sock_xprt *transport =
664 		container_of(work, struct sock_xprt, recv_worker);
665 	xs_stream_data_receive(transport);
666 }
667 
668 static void
669 xs_stream_reset_connect(struct sock_xprt *transport)
670 {
671 	transport->recv.offset = 0;
672 	transport->recv.len = 0;
673 	transport->recv.copied = 0;
674 	transport->xmit.offset = 0;
675 	transport->xprt.stat.connect_count++;
676 	transport->xprt.stat.connect_start = jiffies;
677 }
678 
679 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
680 
681 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
682 {
683 	struct msghdr msg = {
684 		.msg_name	= addr,
685 		.msg_namelen	= addrlen,
686 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
687 	};
688 	struct kvec iov = {
689 		.iov_base	= vec->iov_base + base,
690 		.iov_len	= vec->iov_len - base,
691 	};
692 
693 	if (iov.iov_len != 0)
694 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
695 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
696 }
697 
698 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
699 {
700 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
701 			int offset, size_t size, int flags);
702 	struct page **ppage;
703 	unsigned int remainder;
704 	int err;
705 
706 	remainder = xdr->page_len - base;
707 	base += xdr->page_base;
708 	ppage = xdr->pages + (base >> PAGE_SHIFT);
709 	base &= ~PAGE_MASK;
710 	do_sendpage = sock->ops->sendpage;
711 	if (!zerocopy)
712 		do_sendpage = sock_no_sendpage;
713 	for(;;) {
714 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
715 		int flags = XS_SENDMSG_FLAGS;
716 
717 		remainder -= len;
718 		if (more)
719 			flags |= MSG_MORE;
720 		if (remainder != 0)
721 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
722 		err = do_sendpage(sock, *ppage, base, len, flags);
723 		if (remainder == 0 || err != len)
724 			break;
725 		*sent_p += err;
726 		ppage++;
727 		base = 0;
728 	}
729 	if (err > 0) {
730 		*sent_p += err;
731 		err = 0;
732 	}
733 	return err;
734 }
735 
736 /**
737  * xs_sendpages - write pages directly to a socket
738  * @sock: socket to send on
739  * @addr: UDP only -- address of destination
740  * @addrlen: UDP only -- length of destination address
741  * @xdr: buffer containing this request
742  * @base: starting position in the buffer
743  * @zerocopy: true if it is safe to use sendpage()
744  * @sent_p: return the total number of bytes successfully queued for sending
745  *
746  */
747 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
748 {
749 	unsigned int remainder = xdr->len - base;
750 	int err = 0;
751 	int sent = 0;
752 
753 	if (unlikely(!sock))
754 		return -ENOTSOCK;
755 
756 	if (base != 0) {
757 		addr = NULL;
758 		addrlen = 0;
759 	}
760 
761 	if (base < xdr->head[0].iov_len || addr != NULL) {
762 		unsigned int len = xdr->head[0].iov_len - base;
763 		remainder -= len;
764 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
765 		if (remainder == 0 || err != len)
766 			goto out;
767 		*sent_p += err;
768 		base = 0;
769 	} else
770 		base -= xdr->head[0].iov_len;
771 
772 	if (base < xdr->page_len) {
773 		unsigned int len = xdr->page_len - base;
774 		remainder -= len;
775 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
776 		*sent_p += sent;
777 		if (remainder == 0 || sent != len)
778 			goto out;
779 		base = 0;
780 	} else
781 		base -= xdr->page_len;
782 
783 	if (base >= xdr->tail[0].iov_len)
784 		return 0;
785 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
786 out:
787 	if (err > 0) {
788 		*sent_p += err;
789 		err = 0;
790 	}
791 	return err;
792 }
793 
794 /**
795  * xs_nospace - handle transmit was incomplete
796  * @req: pointer to RPC request
797  *
798  */
799 static int xs_nospace(struct rpc_rqst *req)
800 {
801 	struct rpc_xprt *xprt = req->rq_xprt;
802 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
803 	struct sock *sk = transport->inet;
804 	int ret = -EAGAIN;
805 
806 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
807 			req->rq_task->tk_pid,
808 			req->rq_slen - transport->xmit.offset,
809 			req->rq_slen);
810 
811 	/* Protect against races with write_space */
812 	spin_lock_bh(&xprt->transport_lock);
813 
814 	/* Don't race with disconnect */
815 	if (xprt_connected(xprt)) {
816 		/* wait for more buffer space */
817 		sk->sk_write_pending++;
818 		xprt_wait_for_buffer_space(xprt);
819 	} else
820 		ret = -ENOTCONN;
821 
822 	spin_unlock_bh(&xprt->transport_lock);
823 
824 	/* Race breaker in case memory is freed before above code is called */
825 	if (ret == -EAGAIN) {
826 		struct socket_wq *wq;
827 
828 		rcu_read_lock();
829 		wq = rcu_dereference(sk->sk_wq);
830 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
831 		rcu_read_unlock();
832 
833 		sk->sk_write_space(sk);
834 	}
835 	return ret;
836 }
837 
838 static void
839 xs_stream_prepare_request(struct rpc_rqst *req)
840 {
841 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_NOIO);
842 }
843 
844 /*
845  * Determine if the previous message in the stream was aborted before it
846  * could complete transmission.
847  */
848 static bool
849 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
850 {
851 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
852 }
853 
854 /*
855  * Construct a stream transport record marker in @buf.
856  */
857 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
858 {
859 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
860 	rpc_fraghdr *base = buf->head[0].iov_base;
861 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
862 }
863 
864 /**
865  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
866  * @req: pointer to RPC request
867  *
868  * Return values:
869  *        0:	The request has been sent
870  *   EAGAIN:	The socket was blocked, please call again later to
871  *		complete the request
872  * ENOTCONN:	Caller needs to invoke connect logic then call again
873  *    other:	Some other error occured, the request was not sent
874  */
875 static int xs_local_send_request(struct rpc_rqst *req)
876 {
877 	struct rpc_xprt *xprt = req->rq_xprt;
878 	struct sock_xprt *transport =
879 				container_of(xprt, struct sock_xprt, xprt);
880 	struct xdr_buf *xdr = &req->rq_snd_buf;
881 	int status;
882 	int sent = 0;
883 
884 	/* Close the stream if the previous transmission was incomplete */
885 	if (xs_send_request_was_aborted(transport, req)) {
886 		xs_close(xprt);
887 		return -ENOTCONN;
888 	}
889 
890 	xs_encode_stream_record_marker(&req->rq_snd_buf);
891 
892 	xs_pktdump("packet data:",
893 			req->rq_svec->iov_base, req->rq_svec->iov_len);
894 
895 	req->rq_xtime = ktime_get();
896 	status = xs_sendpages(transport->sock, NULL, 0, xdr,
897 			      transport->xmit.offset,
898 			      true, &sent);
899 	dprintk("RPC:       %s(%u) = %d\n",
900 			__func__, xdr->len - transport->xmit.offset, status);
901 
902 	if (status == -EAGAIN && sock_writeable(transport->inet))
903 		status = -ENOBUFS;
904 
905 	if (likely(sent > 0) || status == 0) {
906 		transport->xmit.offset += sent;
907 		req->rq_bytes_sent = transport->xmit.offset;
908 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
909 			req->rq_xmit_bytes_sent += transport->xmit.offset;
910 			req->rq_bytes_sent = 0;
911 			transport->xmit.offset = 0;
912 			return 0;
913 		}
914 		status = -EAGAIN;
915 	}
916 
917 	switch (status) {
918 	case -ENOBUFS:
919 		break;
920 	case -EAGAIN:
921 		status = xs_nospace(req);
922 		break;
923 	default:
924 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
925 			-status);
926 		/* fall through */
927 	case -EPIPE:
928 		xs_close(xprt);
929 		status = -ENOTCONN;
930 	}
931 
932 	return status;
933 }
934 
935 /**
936  * xs_udp_send_request - write an RPC request to a UDP socket
937  * @req: pointer to RPC request
938  *
939  * Return values:
940  *        0:	The request has been sent
941  *   EAGAIN:	The socket was blocked, please call again later to
942  *		complete the request
943  * ENOTCONN:	Caller needs to invoke connect logic then call again
944  *    other:	Some other error occurred, the request was not sent
945  */
946 static int xs_udp_send_request(struct rpc_rqst *req)
947 {
948 	struct rpc_xprt *xprt = req->rq_xprt;
949 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
950 	struct xdr_buf *xdr = &req->rq_snd_buf;
951 	int sent = 0;
952 	int status;
953 
954 	xs_pktdump("packet data:",
955 				req->rq_svec->iov_base,
956 				req->rq_svec->iov_len);
957 
958 	if (!xprt_bound(xprt))
959 		return -ENOTCONN;
960 
961 	if (!xprt_request_get_cong(xprt, req))
962 		return -EBADSLT;
963 
964 	req->rq_xtime = ktime_get();
965 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
966 			      xdr, 0, true, &sent);
967 
968 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
969 			xdr->len, status);
970 
971 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
972 	if (status == -EPERM)
973 		goto process_status;
974 
975 	if (status == -EAGAIN && sock_writeable(transport->inet))
976 		status = -ENOBUFS;
977 
978 	if (sent > 0 || status == 0) {
979 		req->rq_xmit_bytes_sent += sent;
980 		if (sent >= req->rq_slen)
981 			return 0;
982 		/* Still some bytes left; set up for a retry later. */
983 		status = -EAGAIN;
984 	}
985 
986 process_status:
987 	switch (status) {
988 	case -ENOTSOCK:
989 		status = -ENOTCONN;
990 		/* Should we call xs_close() here? */
991 		break;
992 	case -EAGAIN:
993 		status = xs_nospace(req);
994 		break;
995 	case -ENETUNREACH:
996 	case -ENOBUFS:
997 	case -EPIPE:
998 	case -ECONNREFUSED:
999 	case -EPERM:
1000 		/* When the server has died, an ICMP port unreachable message
1001 		 * prompts ECONNREFUSED. */
1002 		break;
1003 	default:
1004 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1005 			-status);
1006 	}
1007 
1008 	return status;
1009 }
1010 
1011 /**
1012  * xs_tcp_send_request - write an RPC request to a TCP socket
1013  * @req: pointer to RPC request
1014  *
1015  * Return values:
1016  *        0:	The request has been sent
1017  *   EAGAIN:	The socket was blocked, please call again later to
1018  *		complete the request
1019  * ENOTCONN:	Caller needs to invoke connect logic then call again
1020  *    other:	Some other error occurred, the request was not sent
1021  *
1022  * XXX: In the case of soft timeouts, should we eventually give up
1023  *	if sendmsg is not able to make progress?
1024  */
1025 static int xs_tcp_send_request(struct rpc_rqst *req)
1026 {
1027 	struct rpc_xprt *xprt = req->rq_xprt;
1028 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1029 	struct xdr_buf *xdr = &req->rq_snd_buf;
1030 	bool zerocopy = true;
1031 	bool vm_wait = false;
1032 	int status;
1033 	int sent;
1034 
1035 	/* Close the stream if the previous transmission was incomplete */
1036 	if (xs_send_request_was_aborted(transport, req)) {
1037 		if (transport->sock != NULL)
1038 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1039 		return -ENOTCONN;
1040 	}
1041 
1042 	xs_encode_stream_record_marker(&req->rq_snd_buf);
1043 
1044 	xs_pktdump("packet data:",
1045 				req->rq_svec->iov_base,
1046 				req->rq_svec->iov_len);
1047 	/* Don't use zero copy if this is a resend. If the RPC call
1048 	 * completes while the socket holds a reference to the pages,
1049 	 * then we may end up resending corrupted data.
1050 	 */
1051 	if (req->rq_task->tk_flags & RPC_TASK_SENT)
1052 		zerocopy = false;
1053 
1054 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1055 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1056 
1057 	/* Continue transmitting the packet/record. We must be careful
1058 	 * to cope with writespace callbacks arriving _after_ we have
1059 	 * called sendmsg(). */
1060 	req->rq_xtime = ktime_get();
1061 	while (1) {
1062 		sent = 0;
1063 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
1064 				      transport->xmit.offset,
1065 				      zerocopy, &sent);
1066 
1067 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1068 				xdr->len - transport->xmit.offset, status);
1069 
1070 		/* If we've sent the entire packet, immediately
1071 		 * reset the count of bytes sent. */
1072 		transport->xmit.offset += sent;
1073 		req->rq_bytes_sent = transport->xmit.offset;
1074 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
1075 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1076 			req->rq_bytes_sent = 0;
1077 			transport->xmit.offset = 0;
1078 			return 0;
1079 		}
1080 
1081 		WARN_ON_ONCE(sent == 0 && status == 0);
1082 
1083 		if (status == -EAGAIN ) {
1084 			/*
1085 			 * Return EAGAIN if we're sure we're hitting the
1086 			 * socket send buffer limits.
1087 			 */
1088 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1089 				break;
1090 			/*
1091 			 * Did we hit a memory allocation failure?
1092 			 */
1093 			if (sent == 0) {
1094 				status = -ENOBUFS;
1095 				if (vm_wait)
1096 					break;
1097 				/* Retry, knowing now that we're below the
1098 				 * socket send buffer limit
1099 				 */
1100 				vm_wait = true;
1101 			}
1102 			continue;
1103 		}
1104 		if (status < 0)
1105 			break;
1106 		vm_wait = false;
1107 	}
1108 
1109 	switch (status) {
1110 	case -ENOTSOCK:
1111 		status = -ENOTCONN;
1112 		/* Should we call xs_close() here? */
1113 		break;
1114 	case -EAGAIN:
1115 		status = xs_nospace(req);
1116 		break;
1117 	case -ECONNRESET:
1118 	case -ECONNREFUSED:
1119 	case -ENOTCONN:
1120 	case -EADDRINUSE:
1121 	case -ENOBUFS:
1122 	case -EPIPE:
1123 		break;
1124 	default:
1125 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1126 			-status);
1127 	}
1128 
1129 	return status;
1130 }
1131 
1132 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1133 {
1134 	transport->old_data_ready = sk->sk_data_ready;
1135 	transport->old_state_change = sk->sk_state_change;
1136 	transport->old_write_space = sk->sk_write_space;
1137 	transport->old_error_report = sk->sk_error_report;
1138 }
1139 
1140 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1141 {
1142 	sk->sk_data_ready = transport->old_data_ready;
1143 	sk->sk_state_change = transport->old_state_change;
1144 	sk->sk_write_space = transport->old_write_space;
1145 	sk->sk_error_report = transport->old_error_report;
1146 }
1147 
1148 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1149 {
1150 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1151 
1152 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1153 }
1154 
1155 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1156 {
1157 	smp_mb__before_atomic();
1158 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1159 	clear_bit(XPRT_CLOSING, &xprt->state);
1160 	xs_sock_reset_state_flags(xprt);
1161 	smp_mb__after_atomic();
1162 }
1163 
1164 /**
1165  * xs_error_report - callback to handle TCP socket state errors
1166  * @sk: socket
1167  *
1168  * Note: we don't call sock_error() since there may be a rpc_task
1169  * using the socket, and so we don't want to clear sk->sk_err.
1170  */
1171 static void xs_error_report(struct sock *sk)
1172 {
1173 	struct rpc_xprt *xprt;
1174 	int err;
1175 
1176 	read_lock_bh(&sk->sk_callback_lock);
1177 	if (!(xprt = xprt_from_sock(sk)))
1178 		goto out;
1179 
1180 	err = -sk->sk_err;
1181 	if (err == 0)
1182 		goto out;
1183 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1184 			xprt, -err);
1185 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
1186 	xprt_wake_pending_tasks(xprt, err);
1187  out:
1188 	read_unlock_bh(&sk->sk_callback_lock);
1189 }
1190 
1191 static void xs_reset_transport(struct sock_xprt *transport)
1192 {
1193 	struct socket *sock = transport->sock;
1194 	struct sock *sk = transport->inet;
1195 	struct rpc_xprt *xprt = &transport->xprt;
1196 
1197 	if (sk == NULL)
1198 		return;
1199 
1200 	if (atomic_read(&transport->xprt.swapper))
1201 		sk_clear_memalloc(sk);
1202 
1203 	kernel_sock_shutdown(sock, SHUT_RDWR);
1204 
1205 	mutex_lock(&transport->recv_mutex);
1206 	write_lock_bh(&sk->sk_callback_lock);
1207 	transport->inet = NULL;
1208 	transport->sock = NULL;
1209 
1210 	sk->sk_user_data = NULL;
1211 
1212 	xs_restore_old_callbacks(transport, sk);
1213 	xprt_clear_connected(xprt);
1214 	write_unlock_bh(&sk->sk_callback_lock);
1215 	xs_sock_reset_connection_flags(xprt);
1216 	mutex_unlock(&transport->recv_mutex);
1217 
1218 	trace_rpc_socket_close(xprt, sock);
1219 	sock_release(sock);
1220 
1221 	xprt_disconnect_done(xprt);
1222 }
1223 
1224 /**
1225  * xs_close - close a socket
1226  * @xprt: transport
1227  *
1228  * This is used when all requests are complete; ie, no DRC state remains
1229  * on the server we want to save.
1230  *
1231  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1232  * xs_reset_transport() zeroing the socket from underneath a writer.
1233  */
1234 static void xs_close(struct rpc_xprt *xprt)
1235 {
1236 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1237 
1238 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1239 
1240 	xs_reset_transport(transport);
1241 	xprt->reestablish_timeout = 0;
1242 }
1243 
1244 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1245 {
1246 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1247 		xprt);
1248 	xprt_disconnect_done(xprt);
1249 }
1250 
1251 static void xs_xprt_free(struct rpc_xprt *xprt)
1252 {
1253 	xs_free_peer_addresses(xprt);
1254 	xprt_free(xprt);
1255 }
1256 
1257 /**
1258  * xs_destroy - prepare to shutdown a transport
1259  * @xprt: doomed transport
1260  *
1261  */
1262 static void xs_destroy(struct rpc_xprt *xprt)
1263 {
1264 	struct sock_xprt *transport = container_of(xprt,
1265 			struct sock_xprt, xprt);
1266 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1267 
1268 	cancel_delayed_work_sync(&transport->connect_worker);
1269 	xs_close(xprt);
1270 	cancel_work_sync(&transport->recv_worker);
1271 	xs_xprt_free(xprt);
1272 	module_put(THIS_MODULE);
1273 }
1274 
1275 /**
1276  * xs_udp_data_read_skb - receive callback for UDP sockets
1277  * @xprt: transport
1278  * @sk: socket
1279  * @skb: skbuff
1280  *
1281  */
1282 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1283 		struct sock *sk,
1284 		struct sk_buff *skb)
1285 {
1286 	struct rpc_task *task;
1287 	struct rpc_rqst *rovr;
1288 	int repsize, copied;
1289 	u32 _xid;
1290 	__be32 *xp;
1291 
1292 	repsize = skb->len;
1293 	if (repsize < 4) {
1294 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1295 		return;
1296 	}
1297 
1298 	/* Copy the XID from the skb... */
1299 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1300 	if (xp == NULL)
1301 		return;
1302 
1303 	/* Look up and lock the request corresponding to the given XID */
1304 	spin_lock(&xprt->queue_lock);
1305 	rovr = xprt_lookup_rqst(xprt, *xp);
1306 	if (!rovr)
1307 		goto out_unlock;
1308 	xprt_pin_rqst(rovr);
1309 	xprt_update_rtt(rovr->rq_task);
1310 	spin_unlock(&xprt->queue_lock);
1311 	task = rovr->rq_task;
1312 
1313 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1314 		copied = repsize;
1315 
1316 	/* Suck it into the iovec, verify checksum if not done by hw. */
1317 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1318 		spin_lock(&xprt->queue_lock);
1319 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1320 		goto out_unpin;
1321 	}
1322 
1323 
1324 	spin_lock_bh(&xprt->transport_lock);
1325 	xprt_adjust_cwnd(xprt, task, copied);
1326 	spin_unlock_bh(&xprt->transport_lock);
1327 	spin_lock(&xprt->queue_lock);
1328 	xprt_complete_rqst(task, copied);
1329 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1330 out_unpin:
1331 	xprt_unpin_rqst(rovr);
1332  out_unlock:
1333 	spin_unlock(&xprt->queue_lock);
1334 }
1335 
1336 static void xs_udp_data_receive(struct sock_xprt *transport)
1337 {
1338 	struct sk_buff *skb;
1339 	struct sock *sk;
1340 	int err;
1341 
1342 	mutex_lock(&transport->recv_mutex);
1343 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1344 	sk = transport->inet;
1345 	if (sk == NULL)
1346 		goto out;
1347 	for (;;) {
1348 		skb = skb_recv_udp(sk, 0, 1, &err);
1349 		if (skb == NULL)
1350 			break;
1351 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1352 		consume_skb(skb);
1353 		cond_resched();
1354 	}
1355 out:
1356 	mutex_unlock(&transport->recv_mutex);
1357 }
1358 
1359 static void xs_udp_data_receive_workfn(struct work_struct *work)
1360 {
1361 	struct sock_xprt *transport =
1362 		container_of(work, struct sock_xprt, recv_worker);
1363 	xs_udp_data_receive(transport);
1364 }
1365 
1366 /**
1367  * xs_data_ready - "data ready" callback for UDP sockets
1368  * @sk: socket with data to read
1369  *
1370  */
1371 static void xs_data_ready(struct sock *sk)
1372 {
1373 	struct rpc_xprt *xprt;
1374 
1375 	read_lock_bh(&sk->sk_callback_lock);
1376 	dprintk("RPC:       xs_data_ready...\n");
1377 	xprt = xprt_from_sock(sk);
1378 	if (xprt != NULL) {
1379 		struct sock_xprt *transport = container_of(xprt,
1380 				struct sock_xprt, xprt);
1381 		transport->old_data_ready(sk);
1382 		/* Any data means we had a useful conversation, so
1383 		 * then we don't need to delay the next reconnect
1384 		 */
1385 		if (xprt->reestablish_timeout)
1386 			xprt->reestablish_timeout = 0;
1387 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1388 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1389 	}
1390 	read_unlock_bh(&sk->sk_callback_lock);
1391 }
1392 
1393 /*
1394  * Helper function to force a TCP close if the server is sending
1395  * junk and/or it has put us in CLOSE_WAIT
1396  */
1397 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1398 {
1399 	xprt_force_disconnect(xprt);
1400 }
1401 
1402 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1403 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1404 {
1405 	int ret;
1406 
1407 	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1408 			      SVC_SOCK_ANONYMOUS);
1409 	if (ret < 0)
1410 		return ret;
1411 	return 0;
1412 }
1413 
1414 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1415 {
1416 	return PAGE_SIZE;
1417 }
1418 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1419 
1420 /**
1421  * xs_tcp_state_change - callback to handle TCP socket state changes
1422  * @sk: socket whose state has changed
1423  *
1424  */
1425 static void xs_tcp_state_change(struct sock *sk)
1426 {
1427 	struct rpc_xprt *xprt;
1428 	struct sock_xprt *transport;
1429 
1430 	read_lock_bh(&sk->sk_callback_lock);
1431 	if (!(xprt = xprt_from_sock(sk)))
1432 		goto out;
1433 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1434 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1435 			sk->sk_state, xprt_connected(xprt),
1436 			sock_flag(sk, SOCK_DEAD),
1437 			sock_flag(sk, SOCK_ZAPPED),
1438 			sk->sk_shutdown);
1439 
1440 	transport = container_of(xprt, struct sock_xprt, xprt);
1441 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1442 	switch (sk->sk_state) {
1443 	case TCP_ESTABLISHED:
1444 		spin_lock(&xprt->transport_lock);
1445 		if (!xprt_test_and_set_connected(xprt)) {
1446 			xprt->connect_cookie++;
1447 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1448 			xprt_clear_connecting(xprt);
1449 
1450 			xprt->stat.connect_count++;
1451 			xprt->stat.connect_time += (long)jiffies -
1452 						   xprt->stat.connect_start;
1453 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1454 		}
1455 		spin_unlock(&xprt->transport_lock);
1456 		break;
1457 	case TCP_FIN_WAIT1:
1458 		/* The client initiated a shutdown of the socket */
1459 		xprt->connect_cookie++;
1460 		xprt->reestablish_timeout = 0;
1461 		set_bit(XPRT_CLOSING, &xprt->state);
1462 		smp_mb__before_atomic();
1463 		clear_bit(XPRT_CONNECTED, &xprt->state);
1464 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1465 		smp_mb__after_atomic();
1466 		break;
1467 	case TCP_CLOSE_WAIT:
1468 		/* The server initiated a shutdown of the socket */
1469 		xprt->connect_cookie++;
1470 		clear_bit(XPRT_CONNECTED, &xprt->state);
1471 		xs_tcp_force_close(xprt);
1472 		/* fall through */
1473 	case TCP_CLOSING:
1474 		/*
1475 		 * If the server closed down the connection, make sure that
1476 		 * we back off before reconnecting
1477 		 */
1478 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1479 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1480 		break;
1481 	case TCP_LAST_ACK:
1482 		set_bit(XPRT_CLOSING, &xprt->state);
1483 		smp_mb__before_atomic();
1484 		clear_bit(XPRT_CONNECTED, &xprt->state);
1485 		smp_mb__after_atomic();
1486 		break;
1487 	case TCP_CLOSE:
1488 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1489 					&transport->sock_state))
1490 			xprt_clear_connecting(xprt);
1491 		clear_bit(XPRT_CLOSING, &xprt->state);
1492 		/* Trigger the socket release */
1493 		xs_tcp_force_close(xprt);
1494 	}
1495  out:
1496 	read_unlock_bh(&sk->sk_callback_lock);
1497 }
1498 
1499 static void xs_write_space(struct sock *sk)
1500 {
1501 	struct socket_wq *wq;
1502 	struct rpc_xprt *xprt;
1503 
1504 	if (!sk->sk_socket)
1505 		return;
1506 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1507 
1508 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1509 		return;
1510 	rcu_read_lock();
1511 	wq = rcu_dereference(sk->sk_wq);
1512 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1513 		goto out;
1514 
1515 	if (xprt_write_space(xprt))
1516 		sk->sk_write_pending--;
1517 out:
1518 	rcu_read_unlock();
1519 }
1520 
1521 /**
1522  * xs_udp_write_space - callback invoked when socket buffer space
1523  *                             becomes available
1524  * @sk: socket whose state has changed
1525  *
1526  * Called when more output buffer space is available for this socket.
1527  * We try not to wake our writers until they can make "significant"
1528  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1529  * with a bunch of small requests.
1530  */
1531 static void xs_udp_write_space(struct sock *sk)
1532 {
1533 	read_lock_bh(&sk->sk_callback_lock);
1534 
1535 	/* from net/core/sock.c:sock_def_write_space */
1536 	if (sock_writeable(sk))
1537 		xs_write_space(sk);
1538 
1539 	read_unlock_bh(&sk->sk_callback_lock);
1540 }
1541 
1542 /**
1543  * xs_tcp_write_space - callback invoked when socket buffer space
1544  *                             becomes available
1545  * @sk: socket whose state has changed
1546  *
1547  * Called when more output buffer space is available for this socket.
1548  * We try not to wake our writers until they can make "significant"
1549  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1550  * with a bunch of small requests.
1551  */
1552 static void xs_tcp_write_space(struct sock *sk)
1553 {
1554 	read_lock_bh(&sk->sk_callback_lock);
1555 
1556 	/* from net/core/stream.c:sk_stream_write_space */
1557 	if (sk_stream_is_writeable(sk))
1558 		xs_write_space(sk);
1559 
1560 	read_unlock_bh(&sk->sk_callback_lock);
1561 }
1562 
1563 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1564 {
1565 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1566 	struct sock *sk = transport->inet;
1567 
1568 	if (transport->rcvsize) {
1569 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1570 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1571 	}
1572 	if (transport->sndsize) {
1573 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1574 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1575 		sk->sk_write_space(sk);
1576 	}
1577 }
1578 
1579 /**
1580  * xs_udp_set_buffer_size - set send and receive limits
1581  * @xprt: generic transport
1582  * @sndsize: requested size of send buffer, in bytes
1583  * @rcvsize: requested size of receive buffer, in bytes
1584  *
1585  * Set socket send and receive buffer size limits.
1586  */
1587 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1588 {
1589 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1590 
1591 	transport->sndsize = 0;
1592 	if (sndsize)
1593 		transport->sndsize = sndsize + 1024;
1594 	transport->rcvsize = 0;
1595 	if (rcvsize)
1596 		transport->rcvsize = rcvsize + 1024;
1597 
1598 	xs_udp_do_set_buffer_size(xprt);
1599 }
1600 
1601 /**
1602  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1603  * @task: task that timed out
1604  *
1605  * Adjust the congestion window after a retransmit timeout has occurred.
1606  */
1607 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1608 {
1609 	spin_lock_bh(&xprt->transport_lock);
1610 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1611 	spin_unlock_bh(&xprt->transport_lock);
1612 }
1613 
1614 static int xs_get_random_port(void)
1615 {
1616 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1617 	unsigned short range;
1618 	unsigned short rand;
1619 
1620 	if (max < min)
1621 		return -EADDRINUSE;
1622 	range = max - min + 1;
1623 	rand = (unsigned short) prandom_u32() % range;
1624 	return rand + min;
1625 }
1626 
1627 /**
1628  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1629  * @sock: socket
1630  *
1631  * Note that this function has to be called on all sockets that share the
1632  * same port, and it must be called before binding.
1633  */
1634 static void xs_sock_set_reuseport(struct socket *sock)
1635 {
1636 	int opt = 1;
1637 
1638 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1639 			(char *)&opt, sizeof(opt));
1640 }
1641 
1642 static unsigned short xs_sock_getport(struct socket *sock)
1643 {
1644 	struct sockaddr_storage buf;
1645 	unsigned short port = 0;
1646 
1647 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1648 		goto out;
1649 	switch (buf.ss_family) {
1650 	case AF_INET6:
1651 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1652 		break;
1653 	case AF_INET:
1654 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1655 	}
1656 out:
1657 	return port;
1658 }
1659 
1660 /**
1661  * xs_set_port - reset the port number in the remote endpoint address
1662  * @xprt: generic transport
1663  * @port: new port number
1664  *
1665  */
1666 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1667 {
1668 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1669 
1670 	rpc_set_port(xs_addr(xprt), port);
1671 	xs_update_peer_port(xprt);
1672 }
1673 
1674 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1675 {
1676 	if (transport->srcport == 0)
1677 		transport->srcport = xs_sock_getport(sock);
1678 }
1679 
1680 static int xs_get_srcport(struct sock_xprt *transport)
1681 {
1682 	int port = transport->srcport;
1683 
1684 	if (port == 0 && transport->xprt.resvport)
1685 		port = xs_get_random_port();
1686 	return port;
1687 }
1688 
1689 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1690 {
1691 	if (transport->srcport != 0)
1692 		transport->srcport = 0;
1693 	if (!transport->xprt.resvport)
1694 		return 0;
1695 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1696 		return xprt_max_resvport;
1697 	return --port;
1698 }
1699 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1700 {
1701 	struct sockaddr_storage myaddr;
1702 	int err, nloop = 0;
1703 	int port = xs_get_srcport(transport);
1704 	unsigned short last;
1705 
1706 	/*
1707 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1708 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1709 	 * port selection happen implicitly when the socket is used
1710 	 * (for example at connect time).
1711 	 *
1712 	 * This ensures that we can continue to establish TCP
1713 	 * connections even when all local ephemeral ports are already
1714 	 * a part of some TCP connection.  This makes no difference
1715 	 * for UDP sockets, but also doens't harm them.
1716 	 *
1717 	 * If we're asking for any reserved port (i.e. port == 0 &&
1718 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1719 	 * ensure that port is non-zero and we will bind as needed.
1720 	 */
1721 	if (port <= 0)
1722 		return port;
1723 
1724 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1725 	do {
1726 		rpc_set_port((struct sockaddr *)&myaddr, port);
1727 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1728 				transport->xprt.addrlen);
1729 		if (err == 0) {
1730 			transport->srcport = port;
1731 			break;
1732 		}
1733 		last = port;
1734 		port = xs_next_srcport(transport, port);
1735 		if (port > last)
1736 			nloop++;
1737 	} while (err == -EADDRINUSE && nloop != 2);
1738 
1739 	if (myaddr.ss_family == AF_INET)
1740 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1741 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1742 				port, err ? "failed" : "ok", err);
1743 	else
1744 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1745 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1746 				port, err ? "failed" : "ok", err);
1747 	return err;
1748 }
1749 
1750 /*
1751  * We don't support autobind on AF_LOCAL sockets
1752  */
1753 static void xs_local_rpcbind(struct rpc_task *task)
1754 {
1755 	xprt_set_bound(task->tk_xprt);
1756 }
1757 
1758 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1759 {
1760 }
1761 
1762 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1763 static struct lock_class_key xs_key[2];
1764 static struct lock_class_key xs_slock_key[2];
1765 
1766 static inline void xs_reclassify_socketu(struct socket *sock)
1767 {
1768 	struct sock *sk = sock->sk;
1769 
1770 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1771 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1772 }
1773 
1774 static inline void xs_reclassify_socket4(struct socket *sock)
1775 {
1776 	struct sock *sk = sock->sk;
1777 
1778 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1779 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1780 }
1781 
1782 static inline void xs_reclassify_socket6(struct socket *sock)
1783 {
1784 	struct sock *sk = sock->sk;
1785 
1786 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1787 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1788 }
1789 
1790 static inline void xs_reclassify_socket(int family, struct socket *sock)
1791 {
1792 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1793 		return;
1794 
1795 	switch (family) {
1796 	case AF_LOCAL:
1797 		xs_reclassify_socketu(sock);
1798 		break;
1799 	case AF_INET:
1800 		xs_reclassify_socket4(sock);
1801 		break;
1802 	case AF_INET6:
1803 		xs_reclassify_socket6(sock);
1804 		break;
1805 	}
1806 }
1807 #else
1808 static inline void xs_reclassify_socket(int family, struct socket *sock)
1809 {
1810 }
1811 #endif
1812 
1813 static void xs_dummy_setup_socket(struct work_struct *work)
1814 {
1815 }
1816 
1817 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1818 		struct sock_xprt *transport, int family, int type,
1819 		int protocol, bool reuseport)
1820 {
1821 	struct socket *sock;
1822 	int err;
1823 
1824 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1825 	if (err < 0) {
1826 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1827 				protocol, -err);
1828 		goto out;
1829 	}
1830 	xs_reclassify_socket(family, sock);
1831 
1832 	if (reuseport)
1833 		xs_sock_set_reuseport(sock);
1834 
1835 	err = xs_bind(transport, sock);
1836 	if (err) {
1837 		sock_release(sock);
1838 		goto out;
1839 	}
1840 
1841 	return sock;
1842 out:
1843 	return ERR_PTR(err);
1844 }
1845 
1846 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1847 				      struct socket *sock)
1848 {
1849 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1850 									xprt);
1851 
1852 	if (!transport->inet) {
1853 		struct sock *sk = sock->sk;
1854 
1855 		write_lock_bh(&sk->sk_callback_lock);
1856 
1857 		xs_save_old_callbacks(transport, sk);
1858 
1859 		sk->sk_user_data = xprt;
1860 		sk->sk_data_ready = xs_data_ready;
1861 		sk->sk_write_space = xs_udp_write_space;
1862 		sock_set_flag(sk, SOCK_FASYNC);
1863 		sk->sk_error_report = xs_error_report;
1864 		sk->sk_allocation = GFP_NOIO;
1865 
1866 		xprt_clear_connected(xprt);
1867 
1868 		/* Reset to new socket */
1869 		transport->sock = sock;
1870 		transport->inet = sk;
1871 
1872 		write_unlock_bh(&sk->sk_callback_lock);
1873 	}
1874 
1875 	xs_stream_reset_connect(transport);
1876 
1877 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1878 }
1879 
1880 /**
1881  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1882  * @transport: socket transport to connect
1883  */
1884 static int xs_local_setup_socket(struct sock_xprt *transport)
1885 {
1886 	struct rpc_xprt *xprt = &transport->xprt;
1887 	struct socket *sock;
1888 	int status = -EIO;
1889 
1890 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1891 					SOCK_STREAM, 0, &sock, 1);
1892 	if (status < 0) {
1893 		dprintk("RPC:       can't create AF_LOCAL "
1894 			"transport socket (%d).\n", -status);
1895 		goto out;
1896 	}
1897 	xs_reclassify_socket(AF_LOCAL, sock);
1898 
1899 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1900 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1901 
1902 	status = xs_local_finish_connecting(xprt, sock);
1903 	trace_rpc_socket_connect(xprt, sock, status);
1904 	switch (status) {
1905 	case 0:
1906 		dprintk("RPC:       xprt %p connected to %s\n",
1907 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1908 		xprt->stat.connect_count++;
1909 		xprt->stat.connect_time += (long)jiffies -
1910 					   xprt->stat.connect_start;
1911 		xprt_set_connected(xprt);
1912 	case -ENOBUFS:
1913 		break;
1914 	case -ENOENT:
1915 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1916 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1917 		break;
1918 	case -ECONNREFUSED:
1919 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1920 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1921 		break;
1922 	default:
1923 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1924 				__func__, -status,
1925 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1926 	}
1927 
1928 out:
1929 	xprt_clear_connecting(xprt);
1930 	xprt_wake_pending_tasks(xprt, status);
1931 	return status;
1932 }
1933 
1934 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1935 {
1936 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1937 	int ret;
1938 
1939 	 if (RPC_IS_ASYNC(task)) {
1940 		/*
1941 		 * We want the AF_LOCAL connect to be resolved in the
1942 		 * filesystem namespace of the process making the rpc
1943 		 * call.  Thus we connect synchronously.
1944 		 *
1945 		 * If we want to support asynchronous AF_LOCAL calls,
1946 		 * we'll need to figure out how to pass a namespace to
1947 		 * connect.
1948 		 */
1949 		rpc_exit(task, -ENOTCONN);
1950 		return;
1951 	}
1952 	ret = xs_local_setup_socket(transport);
1953 	if (ret && !RPC_IS_SOFTCONN(task))
1954 		msleep_interruptible(15000);
1955 }
1956 
1957 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1958 /*
1959  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1960  * know that we have exclusive access to the socket), to guard against
1961  * races with xs_reset_transport.
1962  */
1963 static void xs_set_memalloc(struct rpc_xprt *xprt)
1964 {
1965 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1966 			xprt);
1967 
1968 	/*
1969 	 * If there's no sock, then we have nothing to set. The
1970 	 * reconnecting process will get it for us.
1971 	 */
1972 	if (!transport->inet)
1973 		return;
1974 	if (atomic_read(&xprt->swapper))
1975 		sk_set_memalloc(transport->inet);
1976 }
1977 
1978 /**
1979  * xs_enable_swap - Tag this transport as being used for swap.
1980  * @xprt: transport to tag
1981  *
1982  * Take a reference to this transport on behalf of the rpc_clnt, and
1983  * optionally mark it for swapping if it wasn't already.
1984  */
1985 static int
1986 xs_enable_swap(struct rpc_xprt *xprt)
1987 {
1988 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1989 
1990 	if (atomic_inc_return(&xprt->swapper) != 1)
1991 		return 0;
1992 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1993 		return -ERESTARTSYS;
1994 	if (xs->inet)
1995 		sk_set_memalloc(xs->inet);
1996 	xprt_release_xprt(xprt, NULL);
1997 	return 0;
1998 }
1999 
2000 /**
2001  * xs_disable_swap - Untag this transport as being used for swap.
2002  * @xprt: transport to tag
2003  *
2004  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2005  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2006  */
2007 static void
2008 xs_disable_swap(struct rpc_xprt *xprt)
2009 {
2010 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2011 
2012 	if (!atomic_dec_and_test(&xprt->swapper))
2013 		return;
2014 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2015 		return;
2016 	if (xs->inet)
2017 		sk_clear_memalloc(xs->inet);
2018 	xprt_release_xprt(xprt, NULL);
2019 }
2020 #else
2021 static void xs_set_memalloc(struct rpc_xprt *xprt)
2022 {
2023 }
2024 
2025 static int
2026 xs_enable_swap(struct rpc_xprt *xprt)
2027 {
2028 	return -EINVAL;
2029 }
2030 
2031 static void
2032 xs_disable_swap(struct rpc_xprt *xprt)
2033 {
2034 }
2035 #endif
2036 
2037 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2038 {
2039 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2040 
2041 	if (!transport->inet) {
2042 		struct sock *sk = sock->sk;
2043 
2044 		write_lock_bh(&sk->sk_callback_lock);
2045 
2046 		xs_save_old_callbacks(transport, sk);
2047 
2048 		sk->sk_user_data = xprt;
2049 		sk->sk_data_ready = xs_data_ready;
2050 		sk->sk_write_space = xs_udp_write_space;
2051 		sock_set_flag(sk, SOCK_FASYNC);
2052 		sk->sk_allocation = GFP_NOIO;
2053 
2054 		xprt_set_connected(xprt);
2055 
2056 		/* Reset to new socket */
2057 		transport->sock = sock;
2058 		transport->inet = sk;
2059 
2060 		xs_set_memalloc(xprt);
2061 
2062 		write_unlock_bh(&sk->sk_callback_lock);
2063 	}
2064 	xs_udp_do_set_buffer_size(xprt);
2065 
2066 	xprt->stat.connect_start = jiffies;
2067 }
2068 
2069 static void xs_udp_setup_socket(struct work_struct *work)
2070 {
2071 	struct sock_xprt *transport =
2072 		container_of(work, struct sock_xprt, connect_worker.work);
2073 	struct rpc_xprt *xprt = &transport->xprt;
2074 	struct socket *sock;
2075 	int status = -EIO;
2076 
2077 	sock = xs_create_sock(xprt, transport,
2078 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2079 			IPPROTO_UDP, false);
2080 	if (IS_ERR(sock))
2081 		goto out;
2082 
2083 	dprintk("RPC:       worker connecting xprt %p via %s to "
2084 				"%s (port %s)\n", xprt,
2085 			xprt->address_strings[RPC_DISPLAY_PROTO],
2086 			xprt->address_strings[RPC_DISPLAY_ADDR],
2087 			xprt->address_strings[RPC_DISPLAY_PORT]);
2088 
2089 	xs_udp_finish_connecting(xprt, sock);
2090 	trace_rpc_socket_connect(xprt, sock, 0);
2091 	status = 0;
2092 out:
2093 	xprt_clear_connecting(xprt);
2094 	xprt_unlock_connect(xprt, transport);
2095 	xprt_wake_pending_tasks(xprt, status);
2096 }
2097 
2098 /**
2099  * xs_tcp_shutdown - gracefully shut down a TCP socket
2100  * @xprt: transport
2101  *
2102  * Initiates a graceful shutdown of the TCP socket by calling the
2103  * equivalent of shutdown(SHUT_RDWR);
2104  */
2105 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2106 {
2107 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2108 	struct socket *sock = transport->sock;
2109 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2110 
2111 	if (sock == NULL)
2112 		return;
2113 	switch (skst) {
2114 	default:
2115 		kernel_sock_shutdown(sock, SHUT_RDWR);
2116 		trace_rpc_socket_shutdown(xprt, sock);
2117 		break;
2118 	case TCP_CLOSE:
2119 	case TCP_TIME_WAIT:
2120 		xs_reset_transport(transport);
2121 	}
2122 }
2123 
2124 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2125 		struct socket *sock)
2126 {
2127 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2128 	unsigned int keepidle;
2129 	unsigned int keepcnt;
2130 	unsigned int opt_on = 1;
2131 	unsigned int timeo;
2132 
2133 	spin_lock_bh(&xprt->transport_lock);
2134 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2135 	keepcnt = xprt->timeout->to_retries + 1;
2136 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2137 		(xprt->timeout->to_retries + 1);
2138 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2139 	spin_unlock_bh(&xprt->transport_lock);
2140 
2141 	/* TCP Keepalive options */
2142 	kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2143 			(char *)&opt_on, sizeof(opt_on));
2144 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2145 			(char *)&keepidle, sizeof(keepidle));
2146 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2147 			(char *)&keepidle, sizeof(keepidle));
2148 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2149 			(char *)&keepcnt, sizeof(keepcnt));
2150 
2151 	/* TCP user timeout (see RFC5482) */
2152 	kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2153 			(char *)&timeo, sizeof(timeo));
2154 }
2155 
2156 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2157 		unsigned long connect_timeout,
2158 		unsigned long reconnect_timeout)
2159 {
2160 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2161 	struct rpc_timeout to;
2162 	unsigned long initval;
2163 
2164 	spin_lock_bh(&xprt->transport_lock);
2165 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2166 		xprt->max_reconnect_timeout = reconnect_timeout;
2167 	if (connect_timeout < xprt->connect_timeout) {
2168 		memcpy(&to, xprt->timeout, sizeof(to));
2169 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2170 		/* Arbitrary lower limit */
2171 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2172 			initval = XS_TCP_INIT_REEST_TO << 1;
2173 		to.to_initval = initval;
2174 		to.to_maxval = initval;
2175 		memcpy(&transport->tcp_timeout, &to,
2176 				sizeof(transport->tcp_timeout));
2177 		xprt->timeout = &transport->tcp_timeout;
2178 		xprt->connect_timeout = connect_timeout;
2179 	}
2180 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2181 	spin_unlock_bh(&xprt->transport_lock);
2182 }
2183 
2184 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2185 {
2186 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2187 	int ret = -ENOTCONN;
2188 
2189 	if (!transport->inet) {
2190 		struct sock *sk = sock->sk;
2191 		unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2192 
2193 		/* Avoid temporary address, they are bad for long-lived
2194 		 * connections such as NFS mounts.
2195 		 * RFC4941, section 3.6 suggests that:
2196 		 *    Individual applications, which have specific
2197 		 *    knowledge about the normal duration of connections,
2198 		 *    MAY override this as appropriate.
2199 		 */
2200 		kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2201 				(char *)&addr_pref, sizeof(addr_pref));
2202 
2203 		xs_tcp_set_socket_timeouts(xprt, sock);
2204 
2205 		write_lock_bh(&sk->sk_callback_lock);
2206 
2207 		xs_save_old_callbacks(transport, sk);
2208 
2209 		sk->sk_user_data = xprt;
2210 		sk->sk_data_ready = xs_data_ready;
2211 		sk->sk_state_change = xs_tcp_state_change;
2212 		sk->sk_write_space = xs_tcp_write_space;
2213 		sock_set_flag(sk, SOCK_FASYNC);
2214 		sk->sk_error_report = xs_error_report;
2215 		sk->sk_allocation = GFP_NOIO;
2216 
2217 		/* socket options */
2218 		sock_reset_flag(sk, SOCK_LINGER);
2219 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2220 
2221 		xprt_clear_connected(xprt);
2222 
2223 		/* Reset to new socket */
2224 		transport->sock = sock;
2225 		transport->inet = sk;
2226 
2227 		write_unlock_bh(&sk->sk_callback_lock);
2228 	}
2229 
2230 	if (!xprt_bound(xprt))
2231 		goto out;
2232 
2233 	xs_set_memalloc(xprt);
2234 
2235 	/* Reset TCP record info */
2236 	xs_stream_reset_connect(transport);
2237 
2238 	/* Tell the socket layer to start connecting... */
2239 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2240 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2241 	switch (ret) {
2242 	case 0:
2243 		xs_set_srcport(transport, sock);
2244 		/* fall through */
2245 	case -EINPROGRESS:
2246 		/* SYN_SENT! */
2247 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2248 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2249 		break;
2250 	case -EADDRNOTAVAIL:
2251 		/* Source port number is unavailable. Try a new one! */
2252 		transport->srcport = 0;
2253 	}
2254 out:
2255 	return ret;
2256 }
2257 
2258 /**
2259  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2260  *
2261  * Invoked by a work queue tasklet.
2262  */
2263 static void xs_tcp_setup_socket(struct work_struct *work)
2264 {
2265 	struct sock_xprt *transport =
2266 		container_of(work, struct sock_xprt, connect_worker.work);
2267 	struct socket *sock = transport->sock;
2268 	struct rpc_xprt *xprt = &transport->xprt;
2269 	int status = -EIO;
2270 
2271 	if (!sock) {
2272 		sock = xs_create_sock(xprt, transport,
2273 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2274 				IPPROTO_TCP, true);
2275 		if (IS_ERR(sock)) {
2276 			status = PTR_ERR(sock);
2277 			goto out;
2278 		}
2279 	}
2280 
2281 	dprintk("RPC:       worker connecting xprt %p via %s to "
2282 				"%s (port %s)\n", xprt,
2283 			xprt->address_strings[RPC_DISPLAY_PROTO],
2284 			xprt->address_strings[RPC_DISPLAY_ADDR],
2285 			xprt->address_strings[RPC_DISPLAY_PORT]);
2286 
2287 	status = xs_tcp_finish_connecting(xprt, sock);
2288 	trace_rpc_socket_connect(xprt, sock, status);
2289 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2290 			xprt, -status, xprt_connected(xprt),
2291 			sock->sk->sk_state);
2292 	switch (status) {
2293 	default:
2294 		printk("%s: connect returned unhandled error %d\n",
2295 			__func__, status);
2296 		/* fall through */
2297 	case -EADDRNOTAVAIL:
2298 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2299 		 * and retry
2300 		 */
2301 		xs_tcp_force_close(xprt);
2302 		break;
2303 	case 0:
2304 	case -EINPROGRESS:
2305 	case -EALREADY:
2306 		xprt_unlock_connect(xprt, transport);
2307 		return;
2308 	case -EINVAL:
2309 		/* Happens, for instance, if the user specified a link
2310 		 * local IPv6 address without a scope-id.
2311 		 */
2312 	case -ECONNREFUSED:
2313 	case -ECONNRESET:
2314 	case -ENETDOWN:
2315 	case -ENETUNREACH:
2316 	case -EHOSTUNREACH:
2317 	case -EADDRINUSE:
2318 	case -ENOBUFS:
2319 		/*
2320 		 * xs_tcp_force_close() wakes tasks with -EIO.
2321 		 * We need to wake them first to ensure the
2322 		 * correct error code.
2323 		 */
2324 		xprt_wake_pending_tasks(xprt, status);
2325 		xs_tcp_force_close(xprt);
2326 		goto out;
2327 	}
2328 	status = -EAGAIN;
2329 out:
2330 	xprt_clear_connecting(xprt);
2331 	xprt_unlock_connect(xprt, transport);
2332 	xprt_wake_pending_tasks(xprt, status);
2333 }
2334 
2335 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2336 {
2337 	unsigned long start, now = jiffies;
2338 
2339 	start = xprt->stat.connect_start + xprt->reestablish_timeout;
2340 	if (time_after(start, now))
2341 		return start - now;
2342 	return 0;
2343 }
2344 
2345 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2346 {
2347 	xprt->reestablish_timeout <<= 1;
2348 	if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2349 		xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2350 	if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2351 		xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2352 }
2353 
2354 /**
2355  * xs_connect - connect a socket to a remote endpoint
2356  * @xprt: pointer to transport structure
2357  * @task: address of RPC task that manages state of connect request
2358  *
2359  * TCP: If the remote end dropped the connection, delay reconnecting.
2360  *
2361  * UDP socket connects are synchronous, but we use a work queue anyway
2362  * to guarantee that even unprivileged user processes can set up a
2363  * socket on a privileged port.
2364  *
2365  * If a UDP socket connect fails, the delay behavior here prevents
2366  * retry floods (hard mounts).
2367  */
2368 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2369 {
2370 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2371 	unsigned long delay = 0;
2372 
2373 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2374 
2375 	if (transport->sock != NULL) {
2376 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2377 				"seconds\n",
2378 				xprt, xprt->reestablish_timeout / HZ);
2379 
2380 		/* Start by resetting any existing state */
2381 		xs_reset_transport(transport);
2382 
2383 		delay = xs_reconnect_delay(xprt);
2384 		xs_reconnect_backoff(xprt);
2385 
2386 	} else
2387 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2388 
2389 	queue_delayed_work(xprtiod_workqueue,
2390 			&transport->connect_worker,
2391 			delay);
2392 }
2393 
2394 /**
2395  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2396  * @xprt: rpc_xprt struct containing statistics
2397  * @seq: output file
2398  *
2399  */
2400 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2401 {
2402 	long idle_time = 0;
2403 
2404 	if (xprt_connected(xprt))
2405 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2406 
2407 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2408 			"%llu %llu %lu %llu %llu\n",
2409 			xprt->stat.bind_count,
2410 			xprt->stat.connect_count,
2411 			xprt->stat.connect_time / HZ,
2412 			idle_time,
2413 			xprt->stat.sends,
2414 			xprt->stat.recvs,
2415 			xprt->stat.bad_xids,
2416 			xprt->stat.req_u,
2417 			xprt->stat.bklog_u,
2418 			xprt->stat.max_slots,
2419 			xprt->stat.sending_u,
2420 			xprt->stat.pending_u);
2421 }
2422 
2423 /**
2424  * xs_udp_print_stats - display UDP socket-specifc stats
2425  * @xprt: rpc_xprt struct containing statistics
2426  * @seq: output file
2427  *
2428  */
2429 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2430 {
2431 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2432 
2433 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2434 			"%lu %llu %llu\n",
2435 			transport->srcport,
2436 			xprt->stat.bind_count,
2437 			xprt->stat.sends,
2438 			xprt->stat.recvs,
2439 			xprt->stat.bad_xids,
2440 			xprt->stat.req_u,
2441 			xprt->stat.bklog_u,
2442 			xprt->stat.max_slots,
2443 			xprt->stat.sending_u,
2444 			xprt->stat.pending_u);
2445 }
2446 
2447 /**
2448  * xs_tcp_print_stats - display TCP socket-specifc stats
2449  * @xprt: rpc_xprt struct containing statistics
2450  * @seq: output file
2451  *
2452  */
2453 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2454 {
2455 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2456 	long idle_time = 0;
2457 
2458 	if (xprt_connected(xprt))
2459 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2460 
2461 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2462 			"%llu %llu %lu %llu %llu\n",
2463 			transport->srcport,
2464 			xprt->stat.bind_count,
2465 			xprt->stat.connect_count,
2466 			xprt->stat.connect_time / HZ,
2467 			idle_time,
2468 			xprt->stat.sends,
2469 			xprt->stat.recvs,
2470 			xprt->stat.bad_xids,
2471 			xprt->stat.req_u,
2472 			xprt->stat.bklog_u,
2473 			xprt->stat.max_slots,
2474 			xprt->stat.sending_u,
2475 			xprt->stat.pending_u);
2476 }
2477 
2478 /*
2479  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2480  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2481  * to use the server side send routines.
2482  */
2483 static int bc_malloc(struct rpc_task *task)
2484 {
2485 	struct rpc_rqst *rqst = task->tk_rqstp;
2486 	size_t size = rqst->rq_callsize;
2487 	struct page *page;
2488 	struct rpc_buffer *buf;
2489 
2490 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2491 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2492 			  size);
2493 		return -EINVAL;
2494 	}
2495 
2496 	page = alloc_page(GFP_KERNEL);
2497 	if (!page)
2498 		return -ENOMEM;
2499 
2500 	buf = page_address(page);
2501 	buf->len = PAGE_SIZE;
2502 
2503 	rqst->rq_buffer = buf->data;
2504 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2505 	return 0;
2506 }
2507 
2508 /*
2509  * Free the space allocated in the bc_alloc routine
2510  */
2511 static void bc_free(struct rpc_task *task)
2512 {
2513 	void *buffer = task->tk_rqstp->rq_buffer;
2514 	struct rpc_buffer *buf;
2515 
2516 	buf = container_of(buffer, struct rpc_buffer, data);
2517 	free_page((unsigned long)buf);
2518 }
2519 
2520 /*
2521  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2522  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2523  */
2524 static int bc_sendto(struct rpc_rqst *req)
2525 {
2526 	int len;
2527 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2528 	struct rpc_xprt *xprt = req->rq_xprt;
2529 	struct sock_xprt *transport =
2530 				container_of(xprt, struct sock_xprt, xprt);
2531 	struct socket *sock = transport->sock;
2532 	unsigned long headoff;
2533 	unsigned long tailoff;
2534 
2535 	xs_encode_stream_record_marker(xbufp);
2536 
2537 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2538 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2539 	len = svc_send_common(sock, xbufp,
2540 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2541 			      xbufp->tail[0].iov_base, tailoff);
2542 
2543 	if (len != xbufp->len) {
2544 		printk(KERN_NOTICE "Error sending entire callback!\n");
2545 		len = -EAGAIN;
2546 	}
2547 
2548 	return len;
2549 }
2550 
2551 /*
2552  * The send routine. Borrows from svc_send
2553  */
2554 static int bc_send_request(struct rpc_rqst *req)
2555 {
2556 	struct svc_xprt	*xprt;
2557 	int len;
2558 
2559 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2560 	/*
2561 	 * Get the server socket associated with this callback xprt
2562 	 */
2563 	xprt = req->rq_xprt->bc_xprt;
2564 
2565 	/*
2566 	 * Grab the mutex to serialize data as the connection is shared
2567 	 * with the fore channel
2568 	 */
2569 	mutex_lock(&xprt->xpt_mutex);
2570 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2571 		len = -ENOTCONN;
2572 	else
2573 		len = bc_sendto(req);
2574 	mutex_unlock(&xprt->xpt_mutex);
2575 
2576 	if (len > 0)
2577 		len = 0;
2578 
2579 	return len;
2580 }
2581 
2582 /*
2583  * The close routine. Since this is client initiated, we do nothing
2584  */
2585 
2586 static void bc_close(struct rpc_xprt *xprt)
2587 {
2588 }
2589 
2590 /*
2591  * The xprt destroy routine. Again, because this connection is client
2592  * initiated, we do nothing
2593  */
2594 
2595 static void bc_destroy(struct rpc_xprt *xprt)
2596 {
2597 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2598 
2599 	xs_xprt_free(xprt);
2600 	module_put(THIS_MODULE);
2601 }
2602 
2603 static const struct rpc_xprt_ops xs_local_ops = {
2604 	.reserve_xprt		= xprt_reserve_xprt,
2605 	.release_xprt		= xprt_release_xprt,
2606 	.alloc_slot		= xprt_alloc_slot,
2607 	.free_slot		= xprt_free_slot,
2608 	.rpcbind		= xs_local_rpcbind,
2609 	.set_port		= xs_local_set_port,
2610 	.connect		= xs_local_connect,
2611 	.buf_alloc		= rpc_malloc,
2612 	.buf_free		= rpc_free,
2613 	.prepare_request	= xs_stream_prepare_request,
2614 	.send_request		= xs_local_send_request,
2615 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2616 	.close			= xs_close,
2617 	.destroy		= xs_destroy,
2618 	.print_stats		= xs_local_print_stats,
2619 	.enable_swap		= xs_enable_swap,
2620 	.disable_swap		= xs_disable_swap,
2621 };
2622 
2623 static const struct rpc_xprt_ops xs_udp_ops = {
2624 	.set_buffer_size	= xs_udp_set_buffer_size,
2625 	.reserve_xprt		= xprt_reserve_xprt_cong,
2626 	.release_xprt		= xprt_release_xprt_cong,
2627 	.alloc_slot		= xprt_alloc_slot,
2628 	.free_slot		= xprt_free_slot,
2629 	.rpcbind		= rpcb_getport_async,
2630 	.set_port		= xs_set_port,
2631 	.connect		= xs_connect,
2632 	.buf_alloc		= rpc_malloc,
2633 	.buf_free		= rpc_free,
2634 	.send_request		= xs_udp_send_request,
2635 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2636 	.timer			= xs_udp_timer,
2637 	.release_request	= xprt_release_rqst_cong,
2638 	.close			= xs_close,
2639 	.destroy		= xs_destroy,
2640 	.print_stats		= xs_udp_print_stats,
2641 	.enable_swap		= xs_enable_swap,
2642 	.disable_swap		= xs_disable_swap,
2643 	.inject_disconnect	= xs_inject_disconnect,
2644 };
2645 
2646 static const struct rpc_xprt_ops xs_tcp_ops = {
2647 	.reserve_xprt		= xprt_reserve_xprt,
2648 	.release_xprt		= xprt_release_xprt,
2649 	.alloc_slot		= xprt_alloc_slot,
2650 	.free_slot		= xprt_free_slot,
2651 	.rpcbind		= rpcb_getport_async,
2652 	.set_port		= xs_set_port,
2653 	.connect		= xs_connect,
2654 	.buf_alloc		= rpc_malloc,
2655 	.buf_free		= rpc_free,
2656 	.prepare_request	= xs_stream_prepare_request,
2657 	.send_request		= xs_tcp_send_request,
2658 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2659 	.close			= xs_tcp_shutdown,
2660 	.destroy		= xs_destroy,
2661 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2662 	.print_stats		= xs_tcp_print_stats,
2663 	.enable_swap		= xs_enable_swap,
2664 	.disable_swap		= xs_disable_swap,
2665 	.inject_disconnect	= xs_inject_disconnect,
2666 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2667 	.bc_setup		= xprt_setup_bc,
2668 	.bc_up			= xs_tcp_bc_up,
2669 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2670 	.bc_free_rqst		= xprt_free_bc_rqst,
2671 	.bc_destroy		= xprt_destroy_bc,
2672 #endif
2673 };
2674 
2675 /*
2676  * The rpc_xprt_ops for the server backchannel
2677  */
2678 
2679 static const struct rpc_xprt_ops bc_tcp_ops = {
2680 	.reserve_xprt		= xprt_reserve_xprt,
2681 	.release_xprt		= xprt_release_xprt,
2682 	.alloc_slot		= xprt_alloc_slot,
2683 	.free_slot		= xprt_free_slot,
2684 	.buf_alloc		= bc_malloc,
2685 	.buf_free		= bc_free,
2686 	.send_request		= bc_send_request,
2687 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2688 	.close			= bc_close,
2689 	.destroy		= bc_destroy,
2690 	.print_stats		= xs_tcp_print_stats,
2691 	.enable_swap		= xs_enable_swap,
2692 	.disable_swap		= xs_disable_swap,
2693 	.inject_disconnect	= xs_inject_disconnect,
2694 };
2695 
2696 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2697 {
2698 	static const struct sockaddr_in sin = {
2699 		.sin_family		= AF_INET,
2700 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2701 	};
2702 	static const struct sockaddr_in6 sin6 = {
2703 		.sin6_family		= AF_INET6,
2704 		.sin6_addr		= IN6ADDR_ANY_INIT,
2705 	};
2706 
2707 	switch (family) {
2708 	case AF_LOCAL:
2709 		break;
2710 	case AF_INET:
2711 		memcpy(sap, &sin, sizeof(sin));
2712 		break;
2713 	case AF_INET6:
2714 		memcpy(sap, &sin6, sizeof(sin6));
2715 		break;
2716 	default:
2717 		dprintk("RPC:       %s: Bad address family\n", __func__);
2718 		return -EAFNOSUPPORT;
2719 	}
2720 	return 0;
2721 }
2722 
2723 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2724 				      unsigned int slot_table_size,
2725 				      unsigned int max_slot_table_size)
2726 {
2727 	struct rpc_xprt *xprt;
2728 	struct sock_xprt *new;
2729 
2730 	if (args->addrlen > sizeof(xprt->addr)) {
2731 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2732 		return ERR_PTR(-EBADF);
2733 	}
2734 
2735 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2736 			max_slot_table_size);
2737 	if (xprt == NULL) {
2738 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2739 				"rpc_xprt\n");
2740 		return ERR_PTR(-ENOMEM);
2741 	}
2742 
2743 	new = container_of(xprt, struct sock_xprt, xprt);
2744 	mutex_init(&new->recv_mutex);
2745 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2746 	xprt->addrlen = args->addrlen;
2747 	if (args->srcaddr)
2748 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2749 	else {
2750 		int err;
2751 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2752 					(struct sockaddr *)&new->srcaddr);
2753 		if (err != 0) {
2754 			xprt_free(xprt);
2755 			return ERR_PTR(err);
2756 		}
2757 	}
2758 
2759 	return xprt;
2760 }
2761 
2762 static const struct rpc_timeout xs_local_default_timeout = {
2763 	.to_initval = 10 * HZ,
2764 	.to_maxval = 10 * HZ,
2765 	.to_retries = 2,
2766 };
2767 
2768 /**
2769  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2770  * @args: rpc transport creation arguments
2771  *
2772  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2773  */
2774 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2775 {
2776 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2777 	struct sock_xprt *transport;
2778 	struct rpc_xprt *xprt;
2779 	struct rpc_xprt *ret;
2780 
2781 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2782 			xprt_max_tcp_slot_table_entries);
2783 	if (IS_ERR(xprt))
2784 		return xprt;
2785 	transport = container_of(xprt, struct sock_xprt, xprt);
2786 
2787 	xprt->prot = 0;
2788 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2789 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2790 
2791 	xprt->bind_timeout = XS_BIND_TO;
2792 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2793 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2794 
2795 	xprt->ops = &xs_local_ops;
2796 	xprt->timeout = &xs_local_default_timeout;
2797 
2798 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2799 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2800 
2801 	switch (sun->sun_family) {
2802 	case AF_LOCAL:
2803 		if (sun->sun_path[0] != '/') {
2804 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2805 					sun->sun_path);
2806 			ret = ERR_PTR(-EINVAL);
2807 			goto out_err;
2808 		}
2809 		xprt_set_bound(xprt);
2810 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2811 		ret = ERR_PTR(xs_local_setup_socket(transport));
2812 		if (ret)
2813 			goto out_err;
2814 		break;
2815 	default:
2816 		ret = ERR_PTR(-EAFNOSUPPORT);
2817 		goto out_err;
2818 	}
2819 
2820 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2821 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2822 
2823 	if (try_module_get(THIS_MODULE))
2824 		return xprt;
2825 	ret = ERR_PTR(-EINVAL);
2826 out_err:
2827 	xs_xprt_free(xprt);
2828 	return ret;
2829 }
2830 
2831 static const struct rpc_timeout xs_udp_default_timeout = {
2832 	.to_initval = 5 * HZ,
2833 	.to_maxval = 30 * HZ,
2834 	.to_increment = 5 * HZ,
2835 	.to_retries = 5,
2836 };
2837 
2838 /**
2839  * xs_setup_udp - Set up transport to use a UDP socket
2840  * @args: rpc transport creation arguments
2841  *
2842  */
2843 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2844 {
2845 	struct sockaddr *addr = args->dstaddr;
2846 	struct rpc_xprt *xprt;
2847 	struct sock_xprt *transport;
2848 	struct rpc_xprt *ret;
2849 
2850 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2851 			xprt_udp_slot_table_entries);
2852 	if (IS_ERR(xprt))
2853 		return xprt;
2854 	transport = container_of(xprt, struct sock_xprt, xprt);
2855 
2856 	xprt->prot = IPPROTO_UDP;
2857 	xprt->tsh_size = 0;
2858 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2859 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2860 
2861 	xprt->bind_timeout = XS_BIND_TO;
2862 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2863 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2864 
2865 	xprt->ops = &xs_udp_ops;
2866 
2867 	xprt->timeout = &xs_udp_default_timeout;
2868 
2869 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2870 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2871 
2872 	switch (addr->sa_family) {
2873 	case AF_INET:
2874 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2875 			xprt_set_bound(xprt);
2876 
2877 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2878 		break;
2879 	case AF_INET6:
2880 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2881 			xprt_set_bound(xprt);
2882 
2883 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2884 		break;
2885 	default:
2886 		ret = ERR_PTR(-EAFNOSUPPORT);
2887 		goto out_err;
2888 	}
2889 
2890 	if (xprt_bound(xprt))
2891 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2892 				xprt->address_strings[RPC_DISPLAY_ADDR],
2893 				xprt->address_strings[RPC_DISPLAY_PORT],
2894 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2895 	else
2896 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2897 				xprt->address_strings[RPC_DISPLAY_ADDR],
2898 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2899 
2900 	if (try_module_get(THIS_MODULE))
2901 		return xprt;
2902 	ret = ERR_PTR(-EINVAL);
2903 out_err:
2904 	xs_xprt_free(xprt);
2905 	return ret;
2906 }
2907 
2908 static const struct rpc_timeout xs_tcp_default_timeout = {
2909 	.to_initval = 60 * HZ,
2910 	.to_maxval = 60 * HZ,
2911 	.to_retries = 2,
2912 };
2913 
2914 /**
2915  * xs_setup_tcp - Set up transport to use a TCP socket
2916  * @args: rpc transport creation arguments
2917  *
2918  */
2919 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2920 {
2921 	struct sockaddr *addr = args->dstaddr;
2922 	struct rpc_xprt *xprt;
2923 	struct sock_xprt *transport;
2924 	struct rpc_xprt *ret;
2925 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2926 
2927 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2928 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2929 
2930 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2931 			max_slot_table_size);
2932 	if (IS_ERR(xprt))
2933 		return xprt;
2934 	transport = container_of(xprt, struct sock_xprt, xprt);
2935 
2936 	xprt->prot = IPPROTO_TCP;
2937 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2938 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2939 
2940 	xprt->bind_timeout = XS_BIND_TO;
2941 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2942 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2943 
2944 	xprt->ops = &xs_tcp_ops;
2945 	xprt->timeout = &xs_tcp_default_timeout;
2946 
2947 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2948 	xprt->connect_timeout = xprt->timeout->to_initval *
2949 		(xprt->timeout->to_retries + 1);
2950 
2951 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2952 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2953 
2954 	switch (addr->sa_family) {
2955 	case AF_INET:
2956 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2957 			xprt_set_bound(xprt);
2958 
2959 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2960 		break;
2961 	case AF_INET6:
2962 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2963 			xprt_set_bound(xprt);
2964 
2965 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2966 		break;
2967 	default:
2968 		ret = ERR_PTR(-EAFNOSUPPORT);
2969 		goto out_err;
2970 	}
2971 
2972 	if (xprt_bound(xprt))
2973 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2974 				xprt->address_strings[RPC_DISPLAY_ADDR],
2975 				xprt->address_strings[RPC_DISPLAY_PORT],
2976 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2977 	else
2978 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2979 				xprt->address_strings[RPC_DISPLAY_ADDR],
2980 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2981 
2982 	if (try_module_get(THIS_MODULE))
2983 		return xprt;
2984 	ret = ERR_PTR(-EINVAL);
2985 out_err:
2986 	xs_xprt_free(xprt);
2987 	return ret;
2988 }
2989 
2990 /**
2991  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2992  * @args: rpc transport creation arguments
2993  *
2994  */
2995 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2996 {
2997 	struct sockaddr *addr = args->dstaddr;
2998 	struct rpc_xprt *xprt;
2999 	struct sock_xprt *transport;
3000 	struct svc_sock *bc_sock;
3001 	struct rpc_xprt *ret;
3002 
3003 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3004 			xprt_tcp_slot_table_entries);
3005 	if (IS_ERR(xprt))
3006 		return xprt;
3007 	transport = container_of(xprt, struct sock_xprt, xprt);
3008 
3009 	xprt->prot = IPPROTO_TCP;
3010 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3011 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3012 	xprt->timeout = &xs_tcp_default_timeout;
3013 
3014 	/* backchannel */
3015 	xprt_set_bound(xprt);
3016 	xprt->bind_timeout = 0;
3017 	xprt->reestablish_timeout = 0;
3018 	xprt->idle_timeout = 0;
3019 
3020 	xprt->ops = &bc_tcp_ops;
3021 
3022 	switch (addr->sa_family) {
3023 	case AF_INET:
3024 		xs_format_peer_addresses(xprt, "tcp",
3025 					 RPCBIND_NETID_TCP);
3026 		break;
3027 	case AF_INET6:
3028 		xs_format_peer_addresses(xprt, "tcp",
3029 				   RPCBIND_NETID_TCP6);
3030 		break;
3031 	default:
3032 		ret = ERR_PTR(-EAFNOSUPPORT);
3033 		goto out_err;
3034 	}
3035 
3036 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3037 			xprt->address_strings[RPC_DISPLAY_ADDR],
3038 			xprt->address_strings[RPC_DISPLAY_PORT],
3039 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3040 
3041 	/*
3042 	 * Once we've associated a backchannel xprt with a connection,
3043 	 * we want to keep it around as long as the connection lasts,
3044 	 * in case we need to start using it for a backchannel again;
3045 	 * this reference won't be dropped until bc_xprt is destroyed.
3046 	 */
3047 	xprt_get(xprt);
3048 	args->bc_xprt->xpt_bc_xprt = xprt;
3049 	xprt->bc_xprt = args->bc_xprt;
3050 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3051 	transport->sock = bc_sock->sk_sock;
3052 	transport->inet = bc_sock->sk_sk;
3053 
3054 	/*
3055 	 * Since we don't want connections for the backchannel, we set
3056 	 * the xprt status to connected
3057 	 */
3058 	xprt_set_connected(xprt);
3059 
3060 	if (try_module_get(THIS_MODULE))
3061 		return xprt;
3062 
3063 	args->bc_xprt->xpt_bc_xprt = NULL;
3064 	args->bc_xprt->xpt_bc_xps = NULL;
3065 	xprt_put(xprt);
3066 	ret = ERR_PTR(-EINVAL);
3067 out_err:
3068 	xs_xprt_free(xprt);
3069 	return ret;
3070 }
3071 
3072 static struct xprt_class	xs_local_transport = {
3073 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3074 	.name		= "named UNIX socket",
3075 	.owner		= THIS_MODULE,
3076 	.ident		= XPRT_TRANSPORT_LOCAL,
3077 	.setup		= xs_setup_local,
3078 };
3079 
3080 static struct xprt_class	xs_udp_transport = {
3081 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3082 	.name		= "udp",
3083 	.owner		= THIS_MODULE,
3084 	.ident		= XPRT_TRANSPORT_UDP,
3085 	.setup		= xs_setup_udp,
3086 };
3087 
3088 static struct xprt_class	xs_tcp_transport = {
3089 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3090 	.name		= "tcp",
3091 	.owner		= THIS_MODULE,
3092 	.ident		= XPRT_TRANSPORT_TCP,
3093 	.setup		= xs_setup_tcp,
3094 };
3095 
3096 static struct xprt_class	xs_bc_tcp_transport = {
3097 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3098 	.name		= "tcp NFSv4.1 backchannel",
3099 	.owner		= THIS_MODULE,
3100 	.ident		= XPRT_TRANSPORT_BC_TCP,
3101 	.setup		= xs_setup_bc_tcp,
3102 };
3103 
3104 /**
3105  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3106  *
3107  */
3108 int init_socket_xprt(void)
3109 {
3110 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3111 	if (!sunrpc_table_header)
3112 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3113 #endif
3114 
3115 	xprt_register_transport(&xs_local_transport);
3116 	xprt_register_transport(&xs_udp_transport);
3117 	xprt_register_transport(&xs_tcp_transport);
3118 	xprt_register_transport(&xs_bc_tcp_transport);
3119 
3120 	return 0;
3121 }
3122 
3123 /**
3124  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3125  *
3126  */
3127 void cleanup_socket_xprt(void)
3128 {
3129 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3130 	if (sunrpc_table_header) {
3131 		unregister_sysctl_table(sunrpc_table_header);
3132 		sunrpc_table_header = NULL;
3133 	}
3134 #endif
3135 
3136 	xprt_unregister_transport(&xs_local_transport);
3137 	xprt_unregister_transport(&xs_udp_transport);
3138 	xprt_unregister_transport(&xs_tcp_transport);
3139 	xprt_unregister_transport(&xs_bc_tcp_transport);
3140 }
3141 
3142 static int param_set_uint_minmax(const char *val,
3143 		const struct kernel_param *kp,
3144 		unsigned int min, unsigned int max)
3145 {
3146 	unsigned int num;
3147 	int ret;
3148 
3149 	if (!val)
3150 		return -EINVAL;
3151 	ret = kstrtouint(val, 0, &num);
3152 	if (ret)
3153 		return ret;
3154 	if (num < min || num > max)
3155 		return -EINVAL;
3156 	*((unsigned int *)kp->arg) = num;
3157 	return 0;
3158 }
3159 
3160 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3161 {
3162 	return param_set_uint_minmax(val, kp,
3163 			RPC_MIN_RESVPORT,
3164 			RPC_MAX_RESVPORT);
3165 }
3166 
3167 static const struct kernel_param_ops param_ops_portnr = {
3168 	.set = param_set_portnr,
3169 	.get = param_get_uint,
3170 };
3171 
3172 #define param_check_portnr(name, p) \
3173 	__param_check(name, p, unsigned int);
3174 
3175 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3176 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3177 
3178 static int param_set_slot_table_size(const char *val,
3179 				     const struct kernel_param *kp)
3180 {
3181 	return param_set_uint_minmax(val, kp,
3182 			RPC_MIN_SLOT_TABLE,
3183 			RPC_MAX_SLOT_TABLE);
3184 }
3185 
3186 static const struct kernel_param_ops param_ops_slot_table_size = {
3187 	.set = param_set_slot_table_size,
3188 	.get = param_get_uint,
3189 };
3190 
3191 #define param_check_slot_table_size(name, p) \
3192 	__param_check(name, p, unsigned int);
3193 
3194 static int param_set_max_slot_table_size(const char *val,
3195 				     const struct kernel_param *kp)
3196 {
3197 	return param_set_uint_minmax(val, kp,
3198 			RPC_MIN_SLOT_TABLE,
3199 			RPC_MAX_SLOT_TABLE_LIMIT);
3200 }
3201 
3202 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3203 	.set = param_set_max_slot_table_size,
3204 	.get = param_get_uint,
3205 };
3206 
3207 #define param_check_max_slot_table_size(name, p) \
3208 	__param_check(name, p, unsigned int);
3209 
3210 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3211 		   slot_table_size, 0644);
3212 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3213 		   max_slot_table_size, 0644);
3214 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3215 		   slot_table_size, 0644);
3216