xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 5b448065)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/highmem.h>
52 #include <linux/uio.h>
53 #include <linux/sched/mm.h>
54 
55 #include <trace/events/sunrpc.h>
56 
57 #include "socklib.h"
58 #include "sunrpc.h"
59 
60 static void xs_close(struct rpc_xprt *xprt);
61 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
62 		struct socket *sock);
63 
64 /*
65  * xprtsock tunables
66  */
67 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
68 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
69 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
70 
71 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
72 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
73 
74 #define XS_TCP_LINGER_TO	(15U * HZ)
75 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
76 
77 /*
78  * We can register our own files under /proc/sys/sunrpc by
79  * calling register_sysctl_table() again.  The files in that
80  * directory become the union of all files registered there.
81  *
82  * We simply need to make sure that we don't collide with
83  * someone else's file names!
84  */
85 
86 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
87 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
88 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
89 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
90 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
91 
92 static struct ctl_table_header *sunrpc_table_header;
93 
94 /*
95  * FIXME: changing the UDP slot table size should also resize the UDP
96  *        socket buffers for existing UDP transports
97  */
98 static struct ctl_table xs_tunables_table[] = {
99 	{
100 		.procname	= "udp_slot_table_entries",
101 		.data		= &xprt_udp_slot_table_entries,
102 		.maxlen		= sizeof(unsigned int),
103 		.mode		= 0644,
104 		.proc_handler	= proc_dointvec_minmax,
105 		.extra1		= &min_slot_table_size,
106 		.extra2		= &max_slot_table_size
107 	},
108 	{
109 		.procname	= "tcp_slot_table_entries",
110 		.data		= &xprt_tcp_slot_table_entries,
111 		.maxlen		= sizeof(unsigned int),
112 		.mode		= 0644,
113 		.proc_handler	= proc_dointvec_minmax,
114 		.extra1		= &min_slot_table_size,
115 		.extra2		= &max_slot_table_size
116 	},
117 	{
118 		.procname	= "tcp_max_slot_table_entries",
119 		.data		= &xprt_max_tcp_slot_table_entries,
120 		.maxlen		= sizeof(unsigned int),
121 		.mode		= 0644,
122 		.proc_handler	= proc_dointvec_minmax,
123 		.extra1		= &min_slot_table_size,
124 		.extra2		= &max_tcp_slot_table_limit
125 	},
126 	{
127 		.procname	= "min_resvport",
128 		.data		= &xprt_min_resvport,
129 		.maxlen		= sizeof(unsigned int),
130 		.mode		= 0644,
131 		.proc_handler	= proc_dointvec_minmax,
132 		.extra1		= &xprt_min_resvport_limit,
133 		.extra2		= &xprt_max_resvport_limit
134 	},
135 	{
136 		.procname	= "max_resvport",
137 		.data		= &xprt_max_resvport,
138 		.maxlen		= sizeof(unsigned int),
139 		.mode		= 0644,
140 		.proc_handler	= proc_dointvec_minmax,
141 		.extra1		= &xprt_min_resvport_limit,
142 		.extra2		= &xprt_max_resvport_limit
143 	},
144 	{
145 		.procname	= "tcp_fin_timeout",
146 		.data		= &xs_tcp_fin_timeout,
147 		.maxlen		= sizeof(xs_tcp_fin_timeout),
148 		.mode		= 0644,
149 		.proc_handler	= proc_dointvec_jiffies,
150 	},
151 	{ },
152 };
153 
154 static struct ctl_table sunrpc_table[] = {
155 	{
156 		.procname	= "sunrpc",
157 		.mode		= 0555,
158 		.child		= xs_tunables_table
159 	},
160 	{ },
161 };
162 
163 /*
164  * Wait duration for a reply from the RPC portmapper.
165  */
166 #define XS_BIND_TO		(60U * HZ)
167 
168 /*
169  * Delay if a UDP socket connect error occurs.  This is most likely some
170  * kind of resource problem on the local host.
171  */
172 #define XS_UDP_REEST_TO		(2U * HZ)
173 
174 /*
175  * The reestablish timeout allows clients to delay for a bit before attempting
176  * to reconnect to a server that just dropped our connection.
177  *
178  * We implement an exponential backoff when trying to reestablish a TCP
179  * transport connection with the server.  Some servers like to drop a TCP
180  * connection when they are overworked, so we start with a short timeout and
181  * increase over time if the server is down or not responding.
182  */
183 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
184 
185 /*
186  * TCP idle timeout; client drops the transport socket if it is idle
187  * for this long.  Note that we also timeout UDP sockets to prevent
188  * holding port numbers when there is no RPC traffic.
189  */
190 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
191 
192 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
193 # undef  RPC_DEBUG_DATA
194 # define RPCDBG_FACILITY	RPCDBG_TRANS
195 #endif
196 
197 #ifdef RPC_DEBUG_DATA
198 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
199 {
200 	u8 *buf = (u8 *) packet;
201 	int j;
202 
203 	dprintk("RPC:       %s\n", msg);
204 	for (j = 0; j < count && j < 128; j += 4) {
205 		if (!(j & 31)) {
206 			if (j)
207 				dprintk("\n");
208 			dprintk("0x%04x ", j);
209 		}
210 		dprintk("%02x%02x%02x%02x ",
211 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
212 	}
213 	dprintk("\n");
214 }
215 #else
216 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
217 {
218 	/* NOP */
219 }
220 #endif
221 
222 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
223 {
224 	return (struct rpc_xprt *) sk->sk_user_data;
225 }
226 
227 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
228 {
229 	return (struct sockaddr *) &xprt->addr;
230 }
231 
232 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
233 {
234 	return (struct sockaddr_un *) &xprt->addr;
235 }
236 
237 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
238 {
239 	return (struct sockaddr_in *) &xprt->addr;
240 }
241 
242 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
243 {
244 	return (struct sockaddr_in6 *) &xprt->addr;
245 }
246 
247 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
248 {
249 	struct sockaddr *sap = xs_addr(xprt);
250 	struct sockaddr_in6 *sin6;
251 	struct sockaddr_in *sin;
252 	struct sockaddr_un *sun;
253 	char buf[128];
254 
255 	switch (sap->sa_family) {
256 	case AF_LOCAL:
257 		sun = xs_addr_un(xprt);
258 		strlcpy(buf, sun->sun_path, sizeof(buf));
259 		xprt->address_strings[RPC_DISPLAY_ADDR] =
260 						kstrdup(buf, GFP_KERNEL);
261 		break;
262 	case AF_INET:
263 		(void)rpc_ntop(sap, buf, sizeof(buf));
264 		xprt->address_strings[RPC_DISPLAY_ADDR] =
265 						kstrdup(buf, GFP_KERNEL);
266 		sin = xs_addr_in(xprt);
267 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
268 		break;
269 	case AF_INET6:
270 		(void)rpc_ntop(sap, buf, sizeof(buf));
271 		xprt->address_strings[RPC_DISPLAY_ADDR] =
272 						kstrdup(buf, GFP_KERNEL);
273 		sin6 = xs_addr_in6(xprt);
274 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
275 		break;
276 	default:
277 		BUG();
278 	}
279 
280 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
281 }
282 
283 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
284 {
285 	struct sockaddr *sap = xs_addr(xprt);
286 	char buf[128];
287 
288 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
290 
291 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
292 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
293 }
294 
295 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
296 				     const char *protocol,
297 				     const char *netid)
298 {
299 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
300 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
301 	xs_format_common_peer_addresses(xprt);
302 	xs_format_common_peer_ports(xprt);
303 }
304 
305 static void xs_update_peer_port(struct rpc_xprt *xprt)
306 {
307 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
308 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
309 
310 	xs_format_common_peer_ports(xprt);
311 }
312 
313 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
314 {
315 	unsigned int i;
316 
317 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
318 		switch (i) {
319 		case RPC_DISPLAY_PROTO:
320 		case RPC_DISPLAY_NETID:
321 			continue;
322 		default:
323 			kfree(xprt->address_strings[i]);
324 		}
325 }
326 
327 static size_t
328 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
329 {
330 	size_t i,n;
331 
332 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
333 		return want;
334 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
335 	for (i = 0; i < n; i++) {
336 		if (buf->pages[i])
337 			continue;
338 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
339 		if (!buf->pages[i]) {
340 			i *= PAGE_SIZE;
341 			return i > buf->page_base ? i - buf->page_base : 0;
342 		}
343 	}
344 	return want;
345 }
346 
347 static ssize_t
348 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
349 {
350 	ssize_t ret;
351 	if (seek != 0)
352 		iov_iter_advance(&msg->msg_iter, seek);
353 	ret = sock_recvmsg(sock, msg, flags);
354 	return ret > 0 ? ret + seek : ret;
355 }
356 
357 static ssize_t
358 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
359 		struct kvec *kvec, size_t count, size_t seek)
360 {
361 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
362 	return xs_sock_recvmsg(sock, msg, flags, seek);
363 }
364 
365 static ssize_t
366 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
367 		struct bio_vec *bvec, unsigned long nr, size_t count,
368 		size_t seek)
369 {
370 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
371 	return xs_sock_recvmsg(sock, msg, flags, seek);
372 }
373 
374 static ssize_t
375 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
376 		size_t count)
377 {
378 	iov_iter_discard(&msg->msg_iter, READ, count);
379 	return sock_recvmsg(sock, msg, flags);
380 }
381 
382 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
383 static void
384 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
385 {
386 	struct bvec_iter bi = {
387 		.bi_size = count,
388 	};
389 	struct bio_vec bv;
390 
391 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
392 	for_each_bvec(bv, bvec, bi, bi)
393 		flush_dcache_page(bv.bv_page);
394 }
395 #else
396 static inline void
397 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
398 {
399 }
400 #endif
401 
402 static ssize_t
403 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
404 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
405 {
406 	size_t want, seek_init = seek, offset = 0;
407 	ssize_t ret;
408 
409 	want = min_t(size_t, count, buf->head[0].iov_len);
410 	if (seek < want) {
411 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
412 		if (ret <= 0)
413 			goto sock_err;
414 		offset += ret;
415 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
416 			goto out;
417 		if (ret != want)
418 			goto out;
419 		seek = 0;
420 	} else {
421 		seek -= want;
422 		offset += want;
423 	}
424 
425 	want = xs_alloc_sparse_pages(buf,
426 			min_t(size_t, count - offset, buf->page_len),
427 			GFP_KERNEL);
428 	if (seek < want) {
429 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
430 				xdr_buf_pagecount(buf),
431 				want + buf->page_base,
432 				seek + buf->page_base);
433 		if (ret <= 0)
434 			goto sock_err;
435 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
436 		ret -= buf->page_base;
437 		offset += ret;
438 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
439 			goto out;
440 		if (ret != want)
441 			goto out;
442 		seek = 0;
443 	} else {
444 		seek -= want;
445 		offset += want;
446 	}
447 
448 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
449 	if (seek < want) {
450 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
451 		if (ret <= 0)
452 			goto sock_err;
453 		offset += ret;
454 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
455 			goto out;
456 		if (ret != want)
457 			goto out;
458 	} else if (offset < seek_init)
459 		offset = seek_init;
460 	ret = -EMSGSIZE;
461 out:
462 	*read = offset - seek_init;
463 	return ret;
464 sock_err:
465 	offset += seek;
466 	goto out;
467 }
468 
469 static void
470 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
471 {
472 	if (!transport->recv.copied) {
473 		if (buf->head[0].iov_len >= transport->recv.offset)
474 			memcpy(buf->head[0].iov_base,
475 					&transport->recv.xid,
476 					transport->recv.offset);
477 		transport->recv.copied = transport->recv.offset;
478 	}
479 }
480 
481 static bool
482 xs_read_stream_request_done(struct sock_xprt *transport)
483 {
484 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
485 }
486 
487 static void
488 xs_read_stream_check_eor(struct sock_xprt *transport,
489 		struct msghdr *msg)
490 {
491 	if (xs_read_stream_request_done(transport))
492 		msg->msg_flags |= MSG_EOR;
493 }
494 
495 static ssize_t
496 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
497 		int flags, struct rpc_rqst *req)
498 {
499 	struct xdr_buf *buf = &req->rq_private_buf;
500 	size_t want, read;
501 	ssize_t ret;
502 
503 	xs_read_header(transport, buf);
504 
505 	want = transport->recv.len - transport->recv.offset;
506 	if (want != 0) {
507 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
508 				transport->recv.copied + want,
509 				transport->recv.copied,
510 				&read);
511 		transport->recv.offset += read;
512 		transport->recv.copied += read;
513 	}
514 
515 	if (transport->recv.offset == transport->recv.len)
516 		xs_read_stream_check_eor(transport, msg);
517 
518 	if (want == 0)
519 		return 0;
520 
521 	switch (ret) {
522 	default:
523 		break;
524 	case -EFAULT:
525 	case -EMSGSIZE:
526 		msg->msg_flags |= MSG_TRUNC;
527 		return read;
528 	case 0:
529 		return -ESHUTDOWN;
530 	}
531 	return ret < 0 ? ret : read;
532 }
533 
534 static size_t
535 xs_read_stream_headersize(bool isfrag)
536 {
537 	if (isfrag)
538 		return sizeof(__be32);
539 	return 3 * sizeof(__be32);
540 }
541 
542 static ssize_t
543 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
544 		int flags, size_t want, size_t seek)
545 {
546 	struct kvec kvec = {
547 		.iov_base = &transport->recv.fraghdr,
548 		.iov_len = want,
549 	};
550 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
551 }
552 
553 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
554 static ssize_t
555 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
556 {
557 	struct rpc_xprt *xprt = &transport->xprt;
558 	struct rpc_rqst *req;
559 	ssize_t ret;
560 
561 	/* Is this transport associated with the backchannel? */
562 	if (!xprt->bc_serv)
563 		return -ESHUTDOWN;
564 
565 	/* Look up and lock the request corresponding to the given XID */
566 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
567 	if (!req) {
568 		printk(KERN_WARNING "Callback slot table overflowed\n");
569 		return -ESHUTDOWN;
570 	}
571 	if (transport->recv.copied && !req->rq_private_buf.len)
572 		return -ESHUTDOWN;
573 
574 	ret = xs_read_stream_request(transport, msg, flags, req);
575 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
576 		xprt_complete_bc_request(req, transport->recv.copied);
577 	else
578 		req->rq_private_buf.len = transport->recv.copied;
579 
580 	return ret;
581 }
582 #else /* CONFIG_SUNRPC_BACKCHANNEL */
583 static ssize_t
584 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
585 {
586 	return -ESHUTDOWN;
587 }
588 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
589 
590 static ssize_t
591 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
592 {
593 	struct rpc_xprt *xprt = &transport->xprt;
594 	struct rpc_rqst *req;
595 	ssize_t ret = 0;
596 
597 	/* Look up and lock the request corresponding to the given XID */
598 	spin_lock(&xprt->queue_lock);
599 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
600 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
601 		msg->msg_flags |= MSG_TRUNC;
602 		goto out;
603 	}
604 	xprt_pin_rqst(req);
605 	spin_unlock(&xprt->queue_lock);
606 
607 	ret = xs_read_stream_request(transport, msg, flags, req);
608 
609 	spin_lock(&xprt->queue_lock);
610 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
611 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
612 	else
613 		req->rq_private_buf.len = transport->recv.copied;
614 	xprt_unpin_rqst(req);
615 out:
616 	spin_unlock(&xprt->queue_lock);
617 	return ret;
618 }
619 
620 static ssize_t
621 xs_read_stream(struct sock_xprt *transport, int flags)
622 {
623 	struct msghdr msg = { 0 };
624 	size_t want, read = 0;
625 	ssize_t ret = 0;
626 
627 	if (transport->recv.len == 0) {
628 		want = xs_read_stream_headersize(transport->recv.copied != 0);
629 		ret = xs_read_stream_header(transport, &msg, flags, want,
630 				transport->recv.offset);
631 		if (ret <= 0)
632 			goto out_err;
633 		transport->recv.offset = ret;
634 		if (transport->recv.offset != want)
635 			return transport->recv.offset;
636 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
637 			RPC_FRAGMENT_SIZE_MASK;
638 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
639 		read = ret;
640 	}
641 
642 	switch (be32_to_cpu(transport->recv.calldir)) {
643 	default:
644 		msg.msg_flags |= MSG_TRUNC;
645 		break;
646 	case RPC_CALL:
647 		ret = xs_read_stream_call(transport, &msg, flags);
648 		break;
649 	case RPC_REPLY:
650 		ret = xs_read_stream_reply(transport, &msg, flags);
651 	}
652 	if (msg.msg_flags & MSG_TRUNC) {
653 		transport->recv.calldir = cpu_to_be32(-1);
654 		transport->recv.copied = -1;
655 	}
656 	if (ret < 0)
657 		goto out_err;
658 	read += ret;
659 	if (transport->recv.offset < transport->recv.len) {
660 		if (!(msg.msg_flags & MSG_TRUNC))
661 			return read;
662 		msg.msg_flags = 0;
663 		ret = xs_read_discard(transport->sock, &msg, flags,
664 				transport->recv.len - transport->recv.offset);
665 		if (ret <= 0)
666 			goto out_err;
667 		transport->recv.offset += ret;
668 		read += ret;
669 		if (transport->recv.offset != transport->recv.len)
670 			return read;
671 	}
672 	if (xs_read_stream_request_done(transport)) {
673 		trace_xs_stream_read_request(transport);
674 		transport->recv.copied = 0;
675 	}
676 	transport->recv.offset = 0;
677 	transport->recv.len = 0;
678 	return read;
679 out_err:
680 	return ret != 0 ? ret : -ESHUTDOWN;
681 }
682 
683 static __poll_t xs_poll_socket(struct sock_xprt *transport)
684 {
685 	return transport->sock->ops->poll(transport->file, transport->sock,
686 			NULL);
687 }
688 
689 static bool xs_poll_socket_readable(struct sock_xprt *transport)
690 {
691 	__poll_t events = xs_poll_socket(transport);
692 
693 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
694 }
695 
696 static void xs_poll_check_readable(struct sock_xprt *transport)
697 {
698 
699 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
700 	if (!xs_poll_socket_readable(transport))
701 		return;
702 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
703 		queue_work(xprtiod_workqueue, &transport->recv_worker);
704 }
705 
706 static void xs_stream_data_receive(struct sock_xprt *transport)
707 {
708 	size_t read = 0;
709 	ssize_t ret = 0;
710 
711 	mutex_lock(&transport->recv_mutex);
712 	if (transport->sock == NULL)
713 		goto out;
714 	for (;;) {
715 		ret = xs_read_stream(transport, MSG_DONTWAIT);
716 		if (ret < 0)
717 			break;
718 		read += ret;
719 		cond_resched();
720 	}
721 	if (ret == -ESHUTDOWN)
722 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
723 	else
724 		xs_poll_check_readable(transport);
725 out:
726 	mutex_unlock(&transport->recv_mutex);
727 	trace_xs_stream_read_data(&transport->xprt, ret, read);
728 }
729 
730 static void xs_stream_data_receive_workfn(struct work_struct *work)
731 {
732 	struct sock_xprt *transport =
733 		container_of(work, struct sock_xprt, recv_worker);
734 	unsigned int pflags = memalloc_nofs_save();
735 
736 	xs_stream_data_receive(transport);
737 	memalloc_nofs_restore(pflags);
738 }
739 
740 static void
741 xs_stream_reset_connect(struct sock_xprt *transport)
742 {
743 	transport->recv.offset = 0;
744 	transport->recv.len = 0;
745 	transport->recv.copied = 0;
746 	transport->xmit.offset = 0;
747 }
748 
749 static void
750 xs_stream_start_connect(struct sock_xprt *transport)
751 {
752 	transport->xprt.stat.connect_count++;
753 	transport->xprt.stat.connect_start = jiffies;
754 }
755 
756 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
757 
758 /**
759  * xs_nospace - handle transmit was incomplete
760  * @req: pointer to RPC request
761  *
762  */
763 static int xs_nospace(struct rpc_rqst *req)
764 {
765 	struct rpc_xprt *xprt = req->rq_xprt;
766 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
767 	struct sock *sk = transport->inet;
768 	int ret = -EAGAIN;
769 
770 	trace_rpc_socket_nospace(req, transport);
771 
772 	/* Protect against races with write_space */
773 	spin_lock(&xprt->transport_lock);
774 
775 	/* Don't race with disconnect */
776 	if (xprt_connected(xprt)) {
777 		/* wait for more buffer space */
778 		sk->sk_write_pending++;
779 		xprt_wait_for_buffer_space(xprt);
780 	} else
781 		ret = -ENOTCONN;
782 
783 	spin_unlock(&xprt->transport_lock);
784 
785 	/* Race breaker in case memory is freed before above code is called */
786 	if (ret == -EAGAIN) {
787 		struct socket_wq *wq;
788 
789 		rcu_read_lock();
790 		wq = rcu_dereference(sk->sk_wq);
791 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
792 		rcu_read_unlock();
793 
794 		sk->sk_write_space(sk);
795 	}
796 	return ret;
797 }
798 
799 static void
800 xs_stream_prepare_request(struct rpc_rqst *req)
801 {
802 	xdr_free_bvec(&req->rq_rcv_buf);
803 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
804 }
805 
806 /*
807  * Determine if the previous message in the stream was aborted before it
808  * could complete transmission.
809  */
810 static bool
811 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
812 {
813 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
814 }
815 
816 /*
817  * Return the stream record marker field for a record of length < 2^31-1
818  */
819 static rpc_fraghdr
820 xs_stream_record_marker(struct xdr_buf *xdr)
821 {
822 	if (!xdr->len)
823 		return 0;
824 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
825 }
826 
827 /**
828  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
829  * @req: pointer to RPC request
830  *
831  * Return values:
832  *        0:	The request has been sent
833  *   EAGAIN:	The socket was blocked, please call again later to
834  *		complete the request
835  * ENOTCONN:	Caller needs to invoke connect logic then call again
836  *    other:	Some other error occurred, the request was not sent
837  */
838 static int xs_local_send_request(struct rpc_rqst *req)
839 {
840 	struct rpc_xprt *xprt = req->rq_xprt;
841 	struct sock_xprt *transport =
842 				container_of(xprt, struct sock_xprt, xprt);
843 	struct xdr_buf *xdr = &req->rq_snd_buf;
844 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
845 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
846 	struct msghdr msg = {
847 		.msg_flags	= XS_SENDMSG_FLAGS,
848 	};
849 	unsigned int sent;
850 	int status;
851 
852 	/* Close the stream if the previous transmission was incomplete */
853 	if (xs_send_request_was_aborted(transport, req)) {
854 		xs_close(xprt);
855 		return -ENOTCONN;
856 	}
857 
858 	xs_pktdump("packet data:",
859 			req->rq_svec->iov_base, req->rq_svec->iov_len);
860 
861 	req->rq_xtime = ktime_get();
862 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
863 				   transport->xmit.offset, rm, &sent);
864 	dprintk("RPC:       %s(%u) = %d\n",
865 			__func__, xdr->len - transport->xmit.offset, status);
866 
867 	if (status == -EAGAIN && sock_writeable(transport->inet))
868 		status = -ENOBUFS;
869 
870 	if (likely(sent > 0) || status == 0) {
871 		transport->xmit.offset += sent;
872 		req->rq_bytes_sent = transport->xmit.offset;
873 		if (likely(req->rq_bytes_sent >= msglen)) {
874 			req->rq_xmit_bytes_sent += transport->xmit.offset;
875 			transport->xmit.offset = 0;
876 			return 0;
877 		}
878 		status = -EAGAIN;
879 	}
880 
881 	switch (status) {
882 	case -ENOBUFS:
883 		break;
884 	case -EAGAIN:
885 		status = xs_nospace(req);
886 		break;
887 	default:
888 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
889 			-status);
890 		fallthrough;
891 	case -EPIPE:
892 		xs_close(xprt);
893 		status = -ENOTCONN;
894 	}
895 
896 	return status;
897 }
898 
899 /**
900  * xs_udp_send_request - write an RPC request to a UDP socket
901  * @req: pointer to RPC request
902  *
903  * Return values:
904  *        0:	The request has been sent
905  *   EAGAIN:	The socket was blocked, please call again later to
906  *		complete the request
907  * ENOTCONN:	Caller needs to invoke connect logic then call again
908  *    other:	Some other error occurred, the request was not sent
909  */
910 static int xs_udp_send_request(struct rpc_rqst *req)
911 {
912 	struct rpc_xprt *xprt = req->rq_xprt;
913 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
914 	struct xdr_buf *xdr = &req->rq_snd_buf;
915 	struct msghdr msg = {
916 		.msg_name	= xs_addr(xprt),
917 		.msg_namelen	= xprt->addrlen,
918 		.msg_flags	= XS_SENDMSG_FLAGS,
919 	};
920 	unsigned int sent;
921 	int status;
922 
923 	xs_pktdump("packet data:",
924 				req->rq_svec->iov_base,
925 				req->rq_svec->iov_len);
926 
927 	if (!xprt_bound(xprt))
928 		return -ENOTCONN;
929 
930 	if (!xprt_request_get_cong(xprt, req))
931 		return -EBADSLT;
932 
933 	req->rq_xtime = ktime_get();
934 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
935 
936 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
937 			xdr->len, status);
938 
939 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
940 	if (status == -EPERM)
941 		goto process_status;
942 
943 	if (status == -EAGAIN && sock_writeable(transport->inet))
944 		status = -ENOBUFS;
945 
946 	if (sent > 0 || status == 0) {
947 		req->rq_xmit_bytes_sent += sent;
948 		if (sent >= req->rq_slen)
949 			return 0;
950 		/* Still some bytes left; set up for a retry later. */
951 		status = -EAGAIN;
952 	}
953 
954 process_status:
955 	switch (status) {
956 	case -ENOTSOCK:
957 		status = -ENOTCONN;
958 		/* Should we call xs_close() here? */
959 		break;
960 	case -EAGAIN:
961 		status = xs_nospace(req);
962 		break;
963 	case -ENETUNREACH:
964 	case -ENOBUFS:
965 	case -EPIPE:
966 	case -ECONNREFUSED:
967 	case -EPERM:
968 		/* When the server has died, an ICMP port unreachable message
969 		 * prompts ECONNREFUSED. */
970 		break;
971 	default:
972 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
973 			-status);
974 	}
975 
976 	return status;
977 }
978 
979 /**
980  * xs_tcp_send_request - write an RPC request to a TCP socket
981  * @req: pointer to RPC request
982  *
983  * Return values:
984  *        0:	The request has been sent
985  *   EAGAIN:	The socket was blocked, please call again later to
986  *		complete the request
987  * ENOTCONN:	Caller needs to invoke connect logic then call again
988  *    other:	Some other error occurred, the request was not sent
989  *
990  * XXX: In the case of soft timeouts, should we eventually give up
991  *	if sendmsg is not able to make progress?
992  */
993 static int xs_tcp_send_request(struct rpc_rqst *req)
994 {
995 	struct rpc_xprt *xprt = req->rq_xprt;
996 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
997 	struct xdr_buf *xdr = &req->rq_snd_buf;
998 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
999 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1000 	struct msghdr msg = {
1001 		.msg_flags	= XS_SENDMSG_FLAGS,
1002 	};
1003 	bool vm_wait = false;
1004 	unsigned int sent;
1005 	int status;
1006 
1007 	/* Close the stream if the previous transmission was incomplete */
1008 	if (xs_send_request_was_aborted(transport, req)) {
1009 		if (transport->sock != NULL)
1010 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1011 		return -ENOTCONN;
1012 	}
1013 	if (!transport->inet)
1014 		return -ENOTCONN;
1015 
1016 	xs_pktdump("packet data:",
1017 				req->rq_svec->iov_base,
1018 				req->rq_svec->iov_len);
1019 
1020 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1021 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1022 
1023 	/* Continue transmitting the packet/record. We must be careful
1024 	 * to cope with writespace callbacks arriving _after_ we have
1025 	 * called sendmsg(). */
1026 	req->rq_xtime = ktime_get();
1027 	tcp_sock_set_cork(transport->inet, true);
1028 	while (1) {
1029 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1030 					   transport->xmit.offset, rm, &sent);
1031 
1032 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1033 				xdr->len - transport->xmit.offset, status);
1034 
1035 		/* If we've sent the entire packet, immediately
1036 		 * reset the count of bytes sent. */
1037 		transport->xmit.offset += sent;
1038 		req->rq_bytes_sent = transport->xmit.offset;
1039 		if (likely(req->rq_bytes_sent >= msglen)) {
1040 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1041 			transport->xmit.offset = 0;
1042 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1043 				tcp_sock_set_cork(transport->inet, false);
1044 			return 0;
1045 		}
1046 
1047 		WARN_ON_ONCE(sent == 0 && status == 0);
1048 
1049 		if (status == -EAGAIN ) {
1050 			/*
1051 			 * Return EAGAIN if we're sure we're hitting the
1052 			 * socket send buffer limits.
1053 			 */
1054 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1055 				break;
1056 			/*
1057 			 * Did we hit a memory allocation failure?
1058 			 */
1059 			if (sent == 0) {
1060 				status = -ENOBUFS;
1061 				if (vm_wait)
1062 					break;
1063 				/* Retry, knowing now that we're below the
1064 				 * socket send buffer limit
1065 				 */
1066 				vm_wait = true;
1067 			}
1068 			continue;
1069 		}
1070 		if (status < 0)
1071 			break;
1072 		vm_wait = false;
1073 	}
1074 
1075 	switch (status) {
1076 	case -ENOTSOCK:
1077 		status = -ENOTCONN;
1078 		/* Should we call xs_close() here? */
1079 		break;
1080 	case -EAGAIN:
1081 		status = xs_nospace(req);
1082 		break;
1083 	case -ECONNRESET:
1084 	case -ECONNREFUSED:
1085 	case -ENOTCONN:
1086 	case -EADDRINUSE:
1087 	case -ENOBUFS:
1088 	case -EPIPE:
1089 		break;
1090 	default:
1091 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1092 			-status);
1093 	}
1094 
1095 	return status;
1096 }
1097 
1098 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1099 {
1100 	transport->old_data_ready = sk->sk_data_ready;
1101 	transport->old_state_change = sk->sk_state_change;
1102 	transport->old_write_space = sk->sk_write_space;
1103 	transport->old_error_report = sk->sk_error_report;
1104 }
1105 
1106 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1107 {
1108 	sk->sk_data_ready = transport->old_data_ready;
1109 	sk->sk_state_change = transport->old_state_change;
1110 	sk->sk_write_space = transport->old_write_space;
1111 	sk->sk_error_report = transport->old_error_report;
1112 }
1113 
1114 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1115 {
1116 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1117 
1118 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1119 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1120 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1121 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1122 }
1123 
1124 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1125 {
1126 	set_bit(nr, &transport->sock_state);
1127 	queue_work(xprtiod_workqueue, &transport->error_worker);
1128 }
1129 
1130 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1131 {
1132 	smp_mb__before_atomic();
1133 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1134 	clear_bit(XPRT_CLOSING, &xprt->state);
1135 	xs_sock_reset_state_flags(xprt);
1136 	smp_mb__after_atomic();
1137 }
1138 
1139 /**
1140  * xs_error_report - callback to handle TCP socket state errors
1141  * @sk: socket
1142  *
1143  * Note: we don't call sock_error() since there may be a rpc_task
1144  * using the socket, and so we don't want to clear sk->sk_err.
1145  */
1146 static void xs_error_report(struct sock *sk)
1147 {
1148 	struct sock_xprt *transport;
1149 	struct rpc_xprt *xprt;
1150 
1151 	read_lock_bh(&sk->sk_callback_lock);
1152 	if (!(xprt = xprt_from_sock(sk)))
1153 		goto out;
1154 
1155 	transport = container_of(xprt, struct sock_xprt, xprt);
1156 	transport->xprt_err = -sk->sk_err;
1157 	if (transport->xprt_err == 0)
1158 		goto out;
1159 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1160 			xprt, -transport->xprt_err);
1161 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1162 
1163 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1164 	smp_mb__before_atomic();
1165 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1166  out:
1167 	read_unlock_bh(&sk->sk_callback_lock);
1168 }
1169 
1170 static void xs_reset_transport(struct sock_xprt *transport)
1171 {
1172 	struct socket *sock = transport->sock;
1173 	struct sock *sk = transport->inet;
1174 	struct rpc_xprt *xprt = &transport->xprt;
1175 	struct file *filp = transport->file;
1176 
1177 	if (sk == NULL)
1178 		return;
1179 
1180 	if (atomic_read(&transport->xprt.swapper))
1181 		sk_clear_memalloc(sk);
1182 
1183 	kernel_sock_shutdown(sock, SHUT_RDWR);
1184 
1185 	mutex_lock(&transport->recv_mutex);
1186 	write_lock_bh(&sk->sk_callback_lock);
1187 	transport->inet = NULL;
1188 	transport->sock = NULL;
1189 	transport->file = NULL;
1190 
1191 	sk->sk_user_data = NULL;
1192 
1193 	xs_restore_old_callbacks(transport, sk);
1194 	xprt_clear_connected(xprt);
1195 	write_unlock_bh(&sk->sk_callback_lock);
1196 	xs_sock_reset_connection_flags(xprt);
1197 	/* Reset stream record info */
1198 	xs_stream_reset_connect(transport);
1199 	mutex_unlock(&transport->recv_mutex);
1200 
1201 	trace_rpc_socket_close(xprt, sock);
1202 	fput(filp);
1203 
1204 	xprt_disconnect_done(xprt);
1205 }
1206 
1207 /**
1208  * xs_close - close a socket
1209  * @xprt: transport
1210  *
1211  * This is used when all requests are complete; ie, no DRC state remains
1212  * on the server we want to save.
1213  *
1214  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1215  * xs_reset_transport() zeroing the socket from underneath a writer.
1216  */
1217 static void xs_close(struct rpc_xprt *xprt)
1218 {
1219 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1220 
1221 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1222 
1223 	xs_reset_transport(transport);
1224 	xprt->reestablish_timeout = 0;
1225 }
1226 
1227 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1228 {
1229 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1230 		xprt);
1231 	xprt_disconnect_done(xprt);
1232 }
1233 
1234 static void xs_xprt_free(struct rpc_xprt *xprt)
1235 {
1236 	xs_free_peer_addresses(xprt);
1237 	xprt_free(xprt);
1238 }
1239 
1240 /**
1241  * xs_destroy - prepare to shutdown a transport
1242  * @xprt: doomed transport
1243  *
1244  */
1245 static void xs_destroy(struct rpc_xprt *xprt)
1246 {
1247 	struct sock_xprt *transport = container_of(xprt,
1248 			struct sock_xprt, xprt);
1249 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1250 
1251 	cancel_delayed_work_sync(&transport->connect_worker);
1252 	xs_close(xprt);
1253 	cancel_work_sync(&transport->recv_worker);
1254 	cancel_work_sync(&transport->error_worker);
1255 	xs_xprt_free(xprt);
1256 	module_put(THIS_MODULE);
1257 }
1258 
1259 /**
1260  * xs_udp_data_read_skb - receive callback for UDP sockets
1261  * @xprt: transport
1262  * @sk: socket
1263  * @skb: skbuff
1264  *
1265  */
1266 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1267 		struct sock *sk,
1268 		struct sk_buff *skb)
1269 {
1270 	struct rpc_task *task;
1271 	struct rpc_rqst *rovr;
1272 	int repsize, copied;
1273 	u32 _xid;
1274 	__be32 *xp;
1275 
1276 	repsize = skb->len;
1277 	if (repsize < 4) {
1278 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1279 		return;
1280 	}
1281 
1282 	/* Copy the XID from the skb... */
1283 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1284 	if (xp == NULL)
1285 		return;
1286 
1287 	/* Look up and lock the request corresponding to the given XID */
1288 	spin_lock(&xprt->queue_lock);
1289 	rovr = xprt_lookup_rqst(xprt, *xp);
1290 	if (!rovr)
1291 		goto out_unlock;
1292 	xprt_pin_rqst(rovr);
1293 	xprt_update_rtt(rovr->rq_task);
1294 	spin_unlock(&xprt->queue_lock);
1295 	task = rovr->rq_task;
1296 
1297 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1298 		copied = repsize;
1299 
1300 	/* Suck it into the iovec, verify checksum if not done by hw. */
1301 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1302 		spin_lock(&xprt->queue_lock);
1303 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1304 		goto out_unpin;
1305 	}
1306 
1307 
1308 	spin_lock(&xprt->transport_lock);
1309 	xprt_adjust_cwnd(xprt, task, copied);
1310 	spin_unlock(&xprt->transport_lock);
1311 	spin_lock(&xprt->queue_lock);
1312 	xprt_complete_rqst(task, copied);
1313 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1314 out_unpin:
1315 	xprt_unpin_rqst(rovr);
1316  out_unlock:
1317 	spin_unlock(&xprt->queue_lock);
1318 }
1319 
1320 static void xs_udp_data_receive(struct sock_xprt *transport)
1321 {
1322 	struct sk_buff *skb;
1323 	struct sock *sk;
1324 	int err;
1325 
1326 	mutex_lock(&transport->recv_mutex);
1327 	sk = transport->inet;
1328 	if (sk == NULL)
1329 		goto out;
1330 	for (;;) {
1331 		skb = skb_recv_udp(sk, 0, 1, &err);
1332 		if (skb == NULL)
1333 			break;
1334 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1335 		consume_skb(skb);
1336 		cond_resched();
1337 	}
1338 	xs_poll_check_readable(transport);
1339 out:
1340 	mutex_unlock(&transport->recv_mutex);
1341 }
1342 
1343 static void xs_udp_data_receive_workfn(struct work_struct *work)
1344 {
1345 	struct sock_xprt *transport =
1346 		container_of(work, struct sock_xprt, recv_worker);
1347 	unsigned int pflags = memalloc_nofs_save();
1348 
1349 	xs_udp_data_receive(transport);
1350 	memalloc_nofs_restore(pflags);
1351 }
1352 
1353 /**
1354  * xs_data_ready - "data ready" callback for UDP sockets
1355  * @sk: socket with data to read
1356  *
1357  */
1358 static void xs_data_ready(struct sock *sk)
1359 {
1360 	struct rpc_xprt *xprt;
1361 
1362 	read_lock_bh(&sk->sk_callback_lock);
1363 	dprintk("RPC:       xs_data_ready...\n");
1364 	xprt = xprt_from_sock(sk);
1365 	if (xprt != NULL) {
1366 		struct sock_xprt *transport = container_of(xprt,
1367 				struct sock_xprt, xprt);
1368 		transport->old_data_ready(sk);
1369 		/* Any data means we had a useful conversation, so
1370 		 * then we don't need to delay the next reconnect
1371 		 */
1372 		if (xprt->reestablish_timeout)
1373 			xprt->reestablish_timeout = 0;
1374 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1375 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1376 	}
1377 	read_unlock_bh(&sk->sk_callback_lock);
1378 }
1379 
1380 /*
1381  * Helper function to force a TCP close if the server is sending
1382  * junk and/or it has put us in CLOSE_WAIT
1383  */
1384 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1385 {
1386 	xprt_force_disconnect(xprt);
1387 }
1388 
1389 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1390 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1391 {
1392 	return PAGE_SIZE;
1393 }
1394 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1395 
1396 /**
1397  * xs_tcp_state_change - callback to handle TCP socket state changes
1398  * @sk: socket whose state has changed
1399  *
1400  */
1401 static void xs_tcp_state_change(struct sock *sk)
1402 {
1403 	struct rpc_xprt *xprt;
1404 	struct sock_xprt *transport;
1405 
1406 	read_lock_bh(&sk->sk_callback_lock);
1407 	if (!(xprt = xprt_from_sock(sk)))
1408 		goto out;
1409 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1410 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1411 			sk->sk_state, xprt_connected(xprt),
1412 			sock_flag(sk, SOCK_DEAD),
1413 			sock_flag(sk, SOCK_ZAPPED),
1414 			sk->sk_shutdown);
1415 
1416 	transport = container_of(xprt, struct sock_xprt, xprt);
1417 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1418 	switch (sk->sk_state) {
1419 	case TCP_ESTABLISHED:
1420 		if (!xprt_test_and_set_connected(xprt)) {
1421 			xprt->connect_cookie++;
1422 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1423 			xprt_clear_connecting(xprt);
1424 
1425 			xprt->stat.connect_count++;
1426 			xprt->stat.connect_time += (long)jiffies -
1427 						   xprt->stat.connect_start;
1428 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1429 		}
1430 		break;
1431 	case TCP_FIN_WAIT1:
1432 		/* The client initiated a shutdown of the socket */
1433 		xprt->connect_cookie++;
1434 		xprt->reestablish_timeout = 0;
1435 		set_bit(XPRT_CLOSING, &xprt->state);
1436 		smp_mb__before_atomic();
1437 		clear_bit(XPRT_CONNECTED, &xprt->state);
1438 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1439 		smp_mb__after_atomic();
1440 		break;
1441 	case TCP_CLOSE_WAIT:
1442 		/* The server initiated a shutdown of the socket */
1443 		xprt->connect_cookie++;
1444 		clear_bit(XPRT_CONNECTED, &xprt->state);
1445 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1446 		fallthrough;
1447 	case TCP_CLOSING:
1448 		/*
1449 		 * If the server closed down the connection, make sure that
1450 		 * we back off before reconnecting
1451 		 */
1452 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1453 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1454 		break;
1455 	case TCP_LAST_ACK:
1456 		set_bit(XPRT_CLOSING, &xprt->state);
1457 		smp_mb__before_atomic();
1458 		clear_bit(XPRT_CONNECTED, &xprt->state);
1459 		smp_mb__after_atomic();
1460 		break;
1461 	case TCP_CLOSE:
1462 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1463 					&transport->sock_state))
1464 			xprt_clear_connecting(xprt);
1465 		clear_bit(XPRT_CLOSING, &xprt->state);
1466 		/* Trigger the socket release */
1467 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1468 	}
1469  out:
1470 	read_unlock_bh(&sk->sk_callback_lock);
1471 }
1472 
1473 static void xs_write_space(struct sock *sk)
1474 {
1475 	struct socket_wq *wq;
1476 	struct sock_xprt *transport;
1477 	struct rpc_xprt *xprt;
1478 
1479 	if (!sk->sk_socket)
1480 		return;
1481 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1482 
1483 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1484 		return;
1485 	transport = container_of(xprt, struct sock_xprt, xprt);
1486 	rcu_read_lock();
1487 	wq = rcu_dereference(sk->sk_wq);
1488 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1489 		goto out;
1490 
1491 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1492 	sk->sk_write_pending--;
1493 out:
1494 	rcu_read_unlock();
1495 }
1496 
1497 /**
1498  * xs_udp_write_space - callback invoked when socket buffer space
1499  *                             becomes available
1500  * @sk: socket whose state has changed
1501  *
1502  * Called when more output buffer space is available for this socket.
1503  * We try not to wake our writers until they can make "significant"
1504  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1505  * with a bunch of small requests.
1506  */
1507 static void xs_udp_write_space(struct sock *sk)
1508 {
1509 	read_lock_bh(&sk->sk_callback_lock);
1510 
1511 	/* from net/core/sock.c:sock_def_write_space */
1512 	if (sock_writeable(sk))
1513 		xs_write_space(sk);
1514 
1515 	read_unlock_bh(&sk->sk_callback_lock);
1516 }
1517 
1518 /**
1519  * xs_tcp_write_space - callback invoked when socket buffer space
1520  *                             becomes available
1521  * @sk: socket whose state has changed
1522  *
1523  * Called when more output buffer space is available for this socket.
1524  * We try not to wake our writers until they can make "significant"
1525  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1526  * with a bunch of small requests.
1527  */
1528 static void xs_tcp_write_space(struct sock *sk)
1529 {
1530 	read_lock_bh(&sk->sk_callback_lock);
1531 
1532 	/* from net/core/stream.c:sk_stream_write_space */
1533 	if (sk_stream_is_writeable(sk))
1534 		xs_write_space(sk);
1535 
1536 	read_unlock_bh(&sk->sk_callback_lock);
1537 }
1538 
1539 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1540 {
1541 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1542 	struct sock *sk = transport->inet;
1543 
1544 	if (transport->rcvsize) {
1545 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1546 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1547 	}
1548 	if (transport->sndsize) {
1549 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1550 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1551 		sk->sk_write_space(sk);
1552 	}
1553 }
1554 
1555 /**
1556  * xs_udp_set_buffer_size - set send and receive limits
1557  * @xprt: generic transport
1558  * @sndsize: requested size of send buffer, in bytes
1559  * @rcvsize: requested size of receive buffer, in bytes
1560  *
1561  * Set socket send and receive buffer size limits.
1562  */
1563 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1564 {
1565 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1566 
1567 	transport->sndsize = 0;
1568 	if (sndsize)
1569 		transport->sndsize = sndsize + 1024;
1570 	transport->rcvsize = 0;
1571 	if (rcvsize)
1572 		transport->rcvsize = rcvsize + 1024;
1573 
1574 	xs_udp_do_set_buffer_size(xprt);
1575 }
1576 
1577 /**
1578  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1579  * @xprt: controlling transport
1580  * @task: task that timed out
1581  *
1582  * Adjust the congestion window after a retransmit timeout has occurred.
1583  */
1584 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1585 {
1586 	spin_lock(&xprt->transport_lock);
1587 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1588 	spin_unlock(&xprt->transport_lock);
1589 }
1590 
1591 static int xs_get_random_port(void)
1592 {
1593 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1594 	unsigned short range;
1595 	unsigned short rand;
1596 
1597 	if (max < min)
1598 		return -EADDRINUSE;
1599 	range = max - min + 1;
1600 	rand = (unsigned short) prandom_u32() % range;
1601 	return rand + min;
1602 }
1603 
1604 static unsigned short xs_sock_getport(struct socket *sock)
1605 {
1606 	struct sockaddr_storage buf;
1607 	unsigned short port = 0;
1608 
1609 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1610 		goto out;
1611 	switch (buf.ss_family) {
1612 	case AF_INET6:
1613 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1614 		break;
1615 	case AF_INET:
1616 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1617 	}
1618 out:
1619 	return port;
1620 }
1621 
1622 /**
1623  * xs_set_port - reset the port number in the remote endpoint address
1624  * @xprt: generic transport
1625  * @port: new port number
1626  *
1627  */
1628 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1629 {
1630 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1631 
1632 	rpc_set_port(xs_addr(xprt), port);
1633 	xs_update_peer_port(xprt);
1634 }
1635 
1636 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1637 {
1638 	if (transport->srcport == 0 && transport->xprt.reuseport)
1639 		transport->srcport = xs_sock_getport(sock);
1640 }
1641 
1642 static int xs_get_srcport(struct sock_xprt *transport)
1643 {
1644 	int port = transport->srcport;
1645 
1646 	if (port == 0 && transport->xprt.resvport)
1647 		port = xs_get_random_port();
1648 	return port;
1649 }
1650 
1651 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1652 {
1653 	if (transport->srcport != 0)
1654 		transport->srcport = 0;
1655 	if (!transport->xprt.resvport)
1656 		return 0;
1657 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1658 		return xprt_max_resvport;
1659 	return --port;
1660 }
1661 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1662 {
1663 	struct sockaddr_storage myaddr;
1664 	int err, nloop = 0;
1665 	int port = xs_get_srcport(transport);
1666 	unsigned short last;
1667 
1668 	/*
1669 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1670 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1671 	 * port selection happen implicitly when the socket is used
1672 	 * (for example at connect time).
1673 	 *
1674 	 * This ensures that we can continue to establish TCP
1675 	 * connections even when all local ephemeral ports are already
1676 	 * a part of some TCP connection.  This makes no difference
1677 	 * for UDP sockets, but also doesn't harm them.
1678 	 *
1679 	 * If we're asking for any reserved port (i.e. port == 0 &&
1680 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1681 	 * ensure that port is non-zero and we will bind as needed.
1682 	 */
1683 	if (port <= 0)
1684 		return port;
1685 
1686 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1687 	do {
1688 		rpc_set_port((struct sockaddr *)&myaddr, port);
1689 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1690 				transport->xprt.addrlen);
1691 		if (err == 0) {
1692 			transport->srcport = port;
1693 			break;
1694 		}
1695 		last = port;
1696 		port = xs_next_srcport(transport, port);
1697 		if (port > last)
1698 			nloop++;
1699 	} while (err == -EADDRINUSE && nloop != 2);
1700 
1701 	if (myaddr.ss_family == AF_INET)
1702 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1703 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1704 				port, err ? "failed" : "ok", err);
1705 	else
1706 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1707 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1708 				port, err ? "failed" : "ok", err);
1709 	return err;
1710 }
1711 
1712 /*
1713  * We don't support autobind on AF_LOCAL sockets
1714  */
1715 static void xs_local_rpcbind(struct rpc_task *task)
1716 {
1717 	xprt_set_bound(task->tk_xprt);
1718 }
1719 
1720 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1721 {
1722 }
1723 
1724 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1725 static struct lock_class_key xs_key[2];
1726 static struct lock_class_key xs_slock_key[2];
1727 
1728 static inline void xs_reclassify_socketu(struct socket *sock)
1729 {
1730 	struct sock *sk = sock->sk;
1731 
1732 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1733 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1734 }
1735 
1736 static inline void xs_reclassify_socket4(struct socket *sock)
1737 {
1738 	struct sock *sk = sock->sk;
1739 
1740 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1741 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1742 }
1743 
1744 static inline void xs_reclassify_socket6(struct socket *sock)
1745 {
1746 	struct sock *sk = sock->sk;
1747 
1748 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1749 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1750 }
1751 
1752 static inline void xs_reclassify_socket(int family, struct socket *sock)
1753 {
1754 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1755 		return;
1756 
1757 	switch (family) {
1758 	case AF_LOCAL:
1759 		xs_reclassify_socketu(sock);
1760 		break;
1761 	case AF_INET:
1762 		xs_reclassify_socket4(sock);
1763 		break;
1764 	case AF_INET6:
1765 		xs_reclassify_socket6(sock);
1766 		break;
1767 	}
1768 }
1769 #else
1770 static inline void xs_reclassify_socket(int family, struct socket *sock)
1771 {
1772 }
1773 #endif
1774 
1775 static void xs_dummy_setup_socket(struct work_struct *work)
1776 {
1777 }
1778 
1779 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1780 		struct sock_xprt *transport, int family, int type,
1781 		int protocol, bool reuseport)
1782 {
1783 	struct file *filp;
1784 	struct socket *sock;
1785 	int err;
1786 
1787 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1788 	if (err < 0) {
1789 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1790 				protocol, -err);
1791 		goto out;
1792 	}
1793 	xs_reclassify_socket(family, sock);
1794 
1795 	if (reuseport)
1796 		sock_set_reuseport(sock->sk);
1797 
1798 	err = xs_bind(transport, sock);
1799 	if (err) {
1800 		sock_release(sock);
1801 		goto out;
1802 	}
1803 
1804 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1805 	if (IS_ERR(filp))
1806 		return ERR_CAST(filp);
1807 	transport->file = filp;
1808 
1809 	return sock;
1810 out:
1811 	return ERR_PTR(err);
1812 }
1813 
1814 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1815 				      struct socket *sock)
1816 {
1817 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1818 									xprt);
1819 
1820 	if (!transport->inet) {
1821 		struct sock *sk = sock->sk;
1822 
1823 		write_lock_bh(&sk->sk_callback_lock);
1824 
1825 		xs_save_old_callbacks(transport, sk);
1826 
1827 		sk->sk_user_data = xprt;
1828 		sk->sk_data_ready = xs_data_ready;
1829 		sk->sk_write_space = xs_udp_write_space;
1830 		sock_set_flag(sk, SOCK_FASYNC);
1831 		sk->sk_error_report = xs_error_report;
1832 
1833 		xprt_clear_connected(xprt);
1834 
1835 		/* Reset to new socket */
1836 		transport->sock = sock;
1837 		transport->inet = sk;
1838 
1839 		write_unlock_bh(&sk->sk_callback_lock);
1840 	}
1841 
1842 	xs_stream_start_connect(transport);
1843 
1844 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1845 }
1846 
1847 /**
1848  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1849  * @transport: socket transport to connect
1850  */
1851 static int xs_local_setup_socket(struct sock_xprt *transport)
1852 {
1853 	struct rpc_xprt *xprt = &transport->xprt;
1854 	struct file *filp;
1855 	struct socket *sock;
1856 	int status;
1857 
1858 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1859 					SOCK_STREAM, 0, &sock, 1);
1860 	if (status < 0) {
1861 		dprintk("RPC:       can't create AF_LOCAL "
1862 			"transport socket (%d).\n", -status);
1863 		goto out;
1864 	}
1865 	xs_reclassify_socket(AF_LOCAL, sock);
1866 
1867 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1868 	if (IS_ERR(filp)) {
1869 		status = PTR_ERR(filp);
1870 		goto out;
1871 	}
1872 	transport->file = filp;
1873 
1874 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1875 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1876 
1877 	status = xs_local_finish_connecting(xprt, sock);
1878 	trace_rpc_socket_connect(xprt, sock, status);
1879 	switch (status) {
1880 	case 0:
1881 		dprintk("RPC:       xprt %p connected to %s\n",
1882 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1883 		xprt->stat.connect_count++;
1884 		xprt->stat.connect_time += (long)jiffies -
1885 					   xprt->stat.connect_start;
1886 		xprt_set_connected(xprt);
1887 		break;
1888 	case -ENOBUFS:
1889 		break;
1890 	case -ENOENT:
1891 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1892 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1893 		break;
1894 	case -ECONNREFUSED:
1895 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1896 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1897 		break;
1898 	default:
1899 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1900 				__func__, -status,
1901 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1902 	}
1903 
1904 out:
1905 	xprt_clear_connecting(xprt);
1906 	xprt_wake_pending_tasks(xprt, status);
1907 	return status;
1908 }
1909 
1910 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1911 {
1912 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1913 	int ret;
1914 
1915 	 if (RPC_IS_ASYNC(task)) {
1916 		/*
1917 		 * We want the AF_LOCAL connect to be resolved in the
1918 		 * filesystem namespace of the process making the rpc
1919 		 * call.  Thus we connect synchronously.
1920 		 *
1921 		 * If we want to support asynchronous AF_LOCAL calls,
1922 		 * we'll need to figure out how to pass a namespace to
1923 		 * connect.
1924 		 */
1925 		task->tk_rpc_status = -ENOTCONN;
1926 		rpc_exit(task, -ENOTCONN);
1927 		return;
1928 	}
1929 	ret = xs_local_setup_socket(transport);
1930 	if (ret && !RPC_IS_SOFTCONN(task))
1931 		msleep_interruptible(15000);
1932 }
1933 
1934 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1935 /*
1936  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1937  * know that we have exclusive access to the socket), to guard against
1938  * races with xs_reset_transport.
1939  */
1940 static void xs_set_memalloc(struct rpc_xprt *xprt)
1941 {
1942 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1943 			xprt);
1944 
1945 	/*
1946 	 * If there's no sock, then we have nothing to set. The
1947 	 * reconnecting process will get it for us.
1948 	 */
1949 	if (!transport->inet)
1950 		return;
1951 	if (atomic_read(&xprt->swapper))
1952 		sk_set_memalloc(transport->inet);
1953 }
1954 
1955 /**
1956  * xs_enable_swap - Tag this transport as being used for swap.
1957  * @xprt: transport to tag
1958  *
1959  * Take a reference to this transport on behalf of the rpc_clnt, and
1960  * optionally mark it for swapping if it wasn't already.
1961  */
1962 static int
1963 xs_enable_swap(struct rpc_xprt *xprt)
1964 {
1965 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1966 
1967 	if (atomic_inc_return(&xprt->swapper) != 1)
1968 		return 0;
1969 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1970 		return -ERESTARTSYS;
1971 	if (xs->inet)
1972 		sk_set_memalloc(xs->inet);
1973 	xprt_release_xprt(xprt, NULL);
1974 	return 0;
1975 }
1976 
1977 /**
1978  * xs_disable_swap - Untag this transport as being used for swap.
1979  * @xprt: transport to tag
1980  *
1981  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1982  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1983  */
1984 static void
1985 xs_disable_swap(struct rpc_xprt *xprt)
1986 {
1987 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1988 
1989 	if (!atomic_dec_and_test(&xprt->swapper))
1990 		return;
1991 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1992 		return;
1993 	if (xs->inet)
1994 		sk_clear_memalloc(xs->inet);
1995 	xprt_release_xprt(xprt, NULL);
1996 }
1997 #else
1998 static void xs_set_memalloc(struct rpc_xprt *xprt)
1999 {
2000 }
2001 
2002 static int
2003 xs_enable_swap(struct rpc_xprt *xprt)
2004 {
2005 	return -EINVAL;
2006 }
2007 
2008 static void
2009 xs_disable_swap(struct rpc_xprt *xprt)
2010 {
2011 }
2012 #endif
2013 
2014 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2015 {
2016 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2017 
2018 	if (!transport->inet) {
2019 		struct sock *sk = sock->sk;
2020 
2021 		write_lock_bh(&sk->sk_callback_lock);
2022 
2023 		xs_save_old_callbacks(transport, sk);
2024 
2025 		sk->sk_user_data = xprt;
2026 		sk->sk_data_ready = xs_data_ready;
2027 		sk->sk_write_space = xs_udp_write_space;
2028 		sock_set_flag(sk, SOCK_FASYNC);
2029 
2030 		xprt_set_connected(xprt);
2031 
2032 		/* Reset to new socket */
2033 		transport->sock = sock;
2034 		transport->inet = sk;
2035 
2036 		xs_set_memalloc(xprt);
2037 
2038 		write_unlock_bh(&sk->sk_callback_lock);
2039 	}
2040 	xs_udp_do_set_buffer_size(xprt);
2041 
2042 	xprt->stat.connect_start = jiffies;
2043 }
2044 
2045 static void xs_udp_setup_socket(struct work_struct *work)
2046 {
2047 	struct sock_xprt *transport =
2048 		container_of(work, struct sock_xprt, connect_worker.work);
2049 	struct rpc_xprt *xprt = &transport->xprt;
2050 	struct socket *sock;
2051 	int status = -EIO;
2052 
2053 	sock = xs_create_sock(xprt, transport,
2054 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2055 			IPPROTO_UDP, false);
2056 	if (IS_ERR(sock))
2057 		goto out;
2058 
2059 	dprintk("RPC:       worker connecting xprt %p via %s to "
2060 				"%s (port %s)\n", xprt,
2061 			xprt->address_strings[RPC_DISPLAY_PROTO],
2062 			xprt->address_strings[RPC_DISPLAY_ADDR],
2063 			xprt->address_strings[RPC_DISPLAY_PORT]);
2064 
2065 	xs_udp_finish_connecting(xprt, sock);
2066 	trace_rpc_socket_connect(xprt, sock, 0);
2067 	status = 0;
2068 out:
2069 	xprt_clear_connecting(xprt);
2070 	xprt_unlock_connect(xprt, transport);
2071 	xprt_wake_pending_tasks(xprt, status);
2072 }
2073 
2074 /**
2075  * xs_tcp_shutdown - gracefully shut down a TCP socket
2076  * @xprt: transport
2077  *
2078  * Initiates a graceful shutdown of the TCP socket by calling the
2079  * equivalent of shutdown(SHUT_RDWR);
2080  */
2081 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2082 {
2083 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2084 	struct socket *sock = transport->sock;
2085 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2086 
2087 	if (sock == NULL)
2088 		return;
2089 	switch (skst) {
2090 	default:
2091 		kernel_sock_shutdown(sock, SHUT_RDWR);
2092 		trace_rpc_socket_shutdown(xprt, sock);
2093 		break;
2094 	case TCP_CLOSE:
2095 	case TCP_TIME_WAIT:
2096 		xs_reset_transport(transport);
2097 	}
2098 }
2099 
2100 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2101 		struct socket *sock)
2102 {
2103 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2104 	unsigned int keepidle;
2105 	unsigned int keepcnt;
2106 	unsigned int timeo;
2107 
2108 	spin_lock(&xprt->transport_lock);
2109 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2110 	keepcnt = xprt->timeout->to_retries + 1;
2111 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2112 		(xprt->timeout->to_retries + 1);
2113 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2114 	spin_unlock(&xprt->transport_lock);
2115 
2116 	/* TCP Keepalive options */
2117 	sock_set_keepalive(sock->sk);
2118 	tcp_sock_set_keepidle(sock->sk, keepidle);
2119 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2120 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2121 
2122 	/* TCP user timeout (see RFC5482) */
2123 	tcp_sock_set_user_timeout(sock->sk, timeo);
2124 }
2125 
2126 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2127 		unsigned long connect_timeout,
2128 		unsigned long reconnect_timeout)
2129 {
2130 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2131 	struct rpc_timeout to;
2132 	unsigned long initval;
2133 
2134 	spin_lock(&xprt->transport_lock);
2135 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2136 		xprt->max_reconnect_timeout = reconnect_timeout;
2137 	if (connect_timeout < xprt->connect_timeout) {
2138 		memcpy(&to, xprt->timeout, sizeof(to));
2139 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2140 		/* Arbitrary lower limit */
2141 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2142 			initval = XS_TCP_INIT_REEST_TO << 1;
2143 		to.to_initval = initval;
2144 		to.to_maxval = initval;
2145 		memcpy(&transport->tcp_timeout, &to,
2146 				sizeof(transport->tcp_timeout));
2147 		xprt->timeout = &transport->tcp_timeout;
2148 		xprt->connect_timeout = connect_timeout;
2149 	}
2150 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2151 	spin_unlock(&xprt->transport_lock);
2152 }
2153 
2154 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2155 {
2156 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2157 	int ret = -ENOTCONN;
2158 
2159 	if (!transport->inet) {
2160 		struct sock *sk = sock->sk;
2161 
2162 		/* Avoid temporary address, they are bad for long-lived
2163 		 * connections such as NFS mounts.
2164 		 * RFC4941, section 3.6 suggests that:
2165 		 *    Individual applications, which have specific
2166 		 *    knowledge about the normal duration of connections,
2167 		 *    MAY override this as appropriate.
2168 		 */
2169 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2170 			ip6_sock_set_addr_preferences(sk,
2171 				IPV6_PREFER_SRC_PUBLIC);
2172 		}
2173 
2174 		xs_tcp_set_socket_timeouts(xprt, sock);
2175 		tcp_sock_set_nodelay(sk);
2176 
2177 		write_lock_bh(&sk->sk_callback_lock);
2178 
2179 		xs_save_old_callbacks(transport, sk);
2180 
2181 		sk->sk_user_data = xprt;
2182 		sk->sk_data_ready = xs_data_ready;
2183 		sk->sk_state_change = xs_tcp_state_change;
2184 		sk->sk_write_space = xs_tcp_write_space;
2185 		sock_set_flag(sk, SOCK_FASYNC);
2186 		sk->sk_error_report = xs_error_report;
2187 
2188 		/* socket options */
2189 		sock_reset_flag(sk, SOCK_LINGER);
2190 
2191 		xprt_clear_connected(xprt);
2192 
2193 		/* Reset to new socket */
2194 		transport->sock = sock;
2195 		transport->inet = sk;
2196 
2197 		write_unlock_bh(&sk->sk_callback_lock);
2198 	}
2199 
2200 	if (!xprt_bound(xprt))
2201 		goto out;
2202 
2203 	xs_set_memalloc(xprt);
2204 
2205 	xs_stream_start_connect(transport);
2206 
2207 	/* Tell the socket layer to start connecting... */
2208 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2209 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2210 	switch (ret) {
2211 	case 0:
2212 		xs_set_srcport(transport, sock);
2213 		fallthrough;
2214 	case -EINPROGRESS:
2215 		/* SYN_SENT! */
2216 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2217 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2218 		break;
2219 	case -EADDRNOTAVAIL:
2220 		/* Source port number is unavailable. Try a new one! */
2221 		transport->srcport = 0;
2222 	}
2223 out:
2224 	return ret;
2225 }
2226 
2227 /**
2228  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2229  * @work: queued work item
2230  *
2231  * Invoked by a work queue tasklet.
2232  */
2233 static void xs_tcp_setup_socket(struct work_struct *work)
2234 {
2235 	struct sock_xprt *transport =
2236 		container_of(work, struct sock_xprt, connect_worker.work);
2237 	struct socket *sock = transport->sock;
2238 	struct rpc_xprt *xprt = &transport->xprt;
2239 	int status = -EIO;
2240 
2241 	if (!sock) {
2242 		sock = xs_create_sock(xprt, transport,
2243 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2244 				IPPROTO_TCP, true);
2245 		if (IS_ERR(sock)) {
2246 			status = PTR_ERR(sock);
2247 			goto out;
2248 		}
2249 	}
2250 
2251 	dprintk("RPC:       worker connecting xprt %p via %s to "
2252 				"%s (port %s)\n", xprt,
2253 			xprt->address_strings[RPC_DISPLAY_PROTO],
2254 			xprt->address_strings[RPC_DISPLAY_ADDR],
2255 			xprt->address_strings[RPC_DISPLAY_PORT]);
2256 
2257 	status = xs_tcp_finish_connecting(xprt, sock);
2258 	trace_rpc_socket_connect(xprt, sock, status);
2259 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2260 			xprt, -status, xprt_connected(xprt),
2261 			sock->sk->sk_state);
2262 	switch (status) {
2263 	default:
2264 		printk("%s: connect returned unhandled error %d\n",
2265 			__func__, status);
2266 		fallthrough;
2267 	case -EADDRNOTAVAIL:
2268 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2269 		 * and retry
2270 		 */
2271 		xs_tcp_force_close(xprt);
2272 		break;
2273 	case 0:
2274 	case -EINPROGRESS:
2275 	case -EALREADY:
2276 		xprt_unlock_connect(xprt, transport);
2277 		return;
2278 	case -EINVAL:
2279 		/* Happens, for instance, if the user specified a link
2280 		 * local IPv6 address without a scope-id.
2281 		 */
2282 	case -ECONNREFUSED:
2283 	case -ECONNRESET:
2284 	case -ENETDOWN:
2285 	case -ENETUNREACH:
2286 	case -EHOSTUNREACH:
2287 	case -EADDRINUSE:
2288 	case -ENOBUFS:
2289 		/* xs_tcp_force_close() wakes tasks with a fixed error code.
2290 		 * We need to wake them first to ensure the correct error code.
2291 		 */
2292 		xprt_wake_pending_tasks(xprt, status);
2293 		xs_tcp_force_close(xprt);
2294 		goto out;
2295 	}
2296 	status = -EAGAIN;
2297 out:
2298 	xprt_clear_connecting(xprt);
2299 	xprt_unlock_connect(xprt, transport);
2300 	xprt_wake_pending_tasks(xprt, status);
2301 }
2302 
2303 /**
2304  * xs_connect - connect a socket to a remote endpoint
2305  * @xprt: pointer to transport structure
2306  * @task: address of RPC task that manages state of connect request
2307  *
2308  * TCP: If the remote end dropped the connection, delay reconnecting.
2309  *
2310  * UDP socket connects are synchronous, but we use a work queue anyway
2311  * to guarantee that even unprivileged user processes can set up a
2312  * socket on a privileged port.
2313  *
2314  * If a UDP socket connect fails, the delay behavior here prevents
2315  * retry floods (hard mounts).
2316  */
2317 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2318 {
2319 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2320 	unsigned long delay = 0;
2321 
2322 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2323 
2324 	if (transport->sock != NULL) {
2325 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2326 				"seconds\n",
2327 				xprt, xprt->reestablish_timeout / HZ);
2328 
2329 		/* Start by resetting any existing state */
2330 		xs_reset_transport(transport);
2331 
2332 		delay = xprt_reconnect_delay(xprt);
2333 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2334 
2335 	} else
2336 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2337 
2338 	queue_delayed_work(xprtiod_workqueue,
2339 			&transport->connect_worker,
2340 			delay);
2341 }
2342 
2343 static void xs_wake_disconnect(struct sock_xprt *transport)
2344 {
2345 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2346 		xs_tcp_force_close(&transport->xprt);
2347 }
2348 
2349 static void xs_wake_write(struct sock_xprt *transport)
2350 {
2351 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2352 		xprt_write_space(&transport->xprt);
2353 }
2354 
2355 static void xs_wake_error(struct sock_xprt *transport)
2356 {
2357 	int sockerr;
2358 
2359 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2360 		return;
2361 	mutex_lock(&transport->recv_mutex);
2362 	if (transport->sock == NULL)
2363 		goto out;
2364 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2365 		goto out;
2366 	sockerr = xchg(&transport->xprt_err, 0);
2367 	if (sockerr < 0)
2368 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2369 out:
2370 	mutex_unlock(&transport->recv_mutex);
2371 }
2372 
2373 static void xs_wake_pending(struct sock_xprt *transport)
2374 {
2375 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2376 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2377 }
2378 
2379 static void xs_error_handle(struct work_struct *work)
2380 {
2381 	struct sock_xprt *transport = container_of(work,
2382 			struct sock_xprt, error_worker);
2383 
2384 	xs_wake_disconnect(transport);
2385 	xs_wake_write(transport);
2386 	xs_wake_error(transport);
2387 	xs_wake_pending(transport);
2388 }
2389 
2390 /**
2391  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2392  * @xprt: rpc_xprt struct containing statistics
2393  * @seq: output file
2394  *
2395  */
2396 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2397 {
2398 	long idle_time = 0;
2399 
2400 	if (xprt_connected(xprt))
2401 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2402 
2403 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2404 			"%llu %llu %lu %llu %llu\n",
2405 			xprt->stat.bind_count,
2406 			xprt->stat.connect_count,
2407 			xprt->stat.connect_time / HZ,
2408 			idle_time,
2409 			xprt->stat.sends,
2410 			xprt->stat.recvs,
2411 			xprt->stat.bad_xids,
2412 			xprt->stat.req_u,
2413 			xprt->stat.bklog_u,
2414 			xprt->stat.max_slots,
2415 			xprt->stat.sending_u,
2416 			xprt->stat.pending_u);
2417 }
2418 
2419 /**
2420  * xs_udp_print_stats - display UDP socket-specific stats
2421  * @xprt: rpc_xprt struct containing statistics
2422  * @seq: output file
2423  *
2424  */
2425 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2426 {
2427 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2428 
2429 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2430 			"%lu %llu %llu\n",
2431 			transport->srcport,
2432 			xprt->stat.bind_count,
2433 			xprt->stat.sends,
2434 			xprt->stat.recvs,
2435 			xprt->stat.bad_xids,
2436 			xprt->stat.req_u,
2437 			xprt->stat.bklog_u,
2438 			xprt->stat.max_slots,
2439 			xprt->stat.sending_u,
2440 			xprt->stat.pending_u);
2441 }
2442 
2443 /**
2444  * xs_tcp_print_stats - display TCP socket-specific stats
2445  * @xprt: rpc_xprt struct containing statistics
2446  * @seq: output file
2447  *
2448  */
2449 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2450 {
2451 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2452 	long idle_time = 0;
2453 
2454 	if (xprt_connected(xprt))
2455 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2456 
2457 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2458 			"%llu %llu %lu %llu %llu\n",
2459 			transport->srcport,
2460 			xprt->stat.bind_count,
2461 			xprt->stat.connect_count,
2462 			xprt->stat.connect_time / HZ,
2463 			idle_time,
2464 			xprt->stat.sends,
2465 			xprt->stat.recvs,
2466 			xprt->stat.bad_xids,
2467 			xprt->stat.req_u,
2468 			xprt->stat.bklog_u,
2469 			xprt->stat.max_slots,
2470 			xprt->stat.sending_u,
2471 			xprt->stat.pending_u);
2472 }
2473 
2474 /*
2475  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2476  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2477  * to use the server side send routines.
2478  */
2479 static int bc_malloc(struct rpc_task *task)
2480 {
2481 	struct rpc_rqst *rqst = task->tk_rqstp;
2482 	size_t size = rqst->rq_callsize;
2483 	struct page *page;
2484 	struct rpc_buffer *buf;
2485 
2486 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2487 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2488 			  size);
2489 		return -EINVAL;
2490 	}
2491 
2492 	page = alloc_page(GFP_KERNEL);
2493 	if (!page)
2494 		return -ENOMEM;
2495 
2496 	buf = page_address(page);
2497 	buf->len = PAGE_SIZE;
2498 
2499 	rqst->rq_buffer = buf->data;
2500 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2501 	return 0;
2502 }
2503 
2504 /*
2505  * Free the space allocated in the bc_alloc routine
2506  */
2507 static void bc_free(struct rpc_task *task)
2508 {
2509 	void *buffer = task->tk_rqstp->rq_buffer;
2510 	struct rpc_buffer *buf;
2511 
2512 	buf = container_of(buffer, struct rpc_buffer, data);
2513 	free_page((unsigned long)buf);
2514 }
2515 
2516 static int bc_sendto(struct rpc_rqst *req)
2517 {
2518 	struct xdr_buf *xdr = &req->rq_snd_buf;
2519 	struct sock_xprt *transport =
2520 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2521 	struct msghdr msg = {
2522 		.msg_flags	= 0,
2523 	};
2524 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2525 					 (u32)xdr->len);
2526 	unsigned int sent = 0;
2527 	int err;
2528 
2529 	req->rq_xtime = ktime_get();
2530 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2531 	xdr_free_bvec(xdr);
2532 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2533 		return -EAGAIN;
2534 	return sent;
2535 }
2536 
2537 /**
2538  * bc_send_request - Send a backchannel Call on a TCP socket
2539  * @req: rpc_rqst containing Call message to be sent
2540  *
2541  * xpt_mutex ensures @rqstp's whole message is written to the socket
2542  * without interruption.
2543  *
2544  * Return values:
2545  *   %0 if the message was sent successfully
2546  *   %ENOTCONN if the message was not sent
2547  */
2548 static int bc_send_request(struct rpc_rqst *req)
2549 {
2550 	struct svc_xprt	*xprt;
2551 	int len;
2552 
2553 	/*
2554 	 * Get the server socket associated with this callback xprt
2555 	 */
2556 	xprt = req->rq_xprt->bc_xprt;
2557 
2558 	/*
2559 	 * Grab the mutex to serialize data as the connection is shared
2560 	 * with the fore channel
2561 	 */
2562 	mutex_lock(&xprt->xpt_mutex);
2563 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2564 		len = -ENOTCONN;
2565 	else
2566 		len = bc_sendto(req);
2567 	mutex_unlock(&xprt->xpt_mutex);
2568 
2569 	if (len > 0)
2570 		len = 0;
2571 
2572 	return len;
2573 }
2574 
2575 /*
2576  * The close routine. Since this is client initiated, we do nothing
2577  */
2578 
2579 static void bc_close(struct rpc_xprt *xprt)
2580 {
2581 	xprt_disconnect_done(xprt);
2582 }
2583 
2584 /*
2585  * The xprt destroy routine. Again, because this connection is client
2586  * initiated, we do nothing
2587  */
2588 
2589 static void bc_destroy(struct rpc_xprt *xprt)
2590 {
2591 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2592 
2593 	xs_xprt_free(xprt);
2594 	module_put(THIS_MODULE);
2595 }
2596 
2597 static const struct rpc_xprt_ops xs_local_ops = {
2598 	.reserve_xprt		= xprt_reserve_xprt,
2599 	.release_xprt		= xprt_release_xprt,
2600 	.alloc_slot		= xprt_alloc_slot,
2601 	.free_slot		= xprt_free_slot,
2602 	.rpcbind		= xs_local_rpcbind,
2603 	.set_port		= xs_local_set_port,
2604 	.connect		= xs_local_connect,
2605 	.buf_alloc		= rpc_malloc,
2606 	.buf_free		= rpc_free,
2607 	.prepare_request	= xs_stream_prepare_request,
2608 	.send_request		= xs_local_send_request,
2609 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2610 	.close			= xs_close,
2611 	.destroy		= xs_destroy,
2612 	.print_stats		= xs_local_print_stats,
2613 	.enable_swap		= xs_enable_swap,
2614 	.disable_swap		= xs_disable_swap,
2615 };
2616 
2617 static const struct rpc_xprt_ops xs_udp_ops = {
2618 	.set_buffer_size	= xs_udp_set_buffer_size,
2619 	.reserve_xprt		= xprt_reserve_xprt_cong,
2620 	.release_xprt		= xprt_release_xprt_cong,
2621 	.alloc_slot		= xprt_alloc_slot,
2622 	.free_slot		= xprt_free_slot,
2623 	.rpcbind		= rpcb_getport_async,
2624 	.set_port		= xs_set_port,
2625 	.connect		= xs_connect,
2626 	.buf_alloc		= rpc_malloc,
2627 	.buf_free		= rpc_free,
2628 	.send_request		= xs_udp_send_request,
2629 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2630 	.timer			= xs_udp_timer,
2631 	.release_request	= xprt_release_rqst_cong,
2632 	.close			= xs_close,
2633 	.destroy		= xs_destroy,
2634 	.print_stats		= xs_udp_print_stats,
2635 	.enable_swap		= xs_enable_swap,
2636 	.disable_swap		= xs_disable_swap,
2637 	.inject_disconnect	= xs_inject_disconnect,
2638 };
2639 
2640 static const struct rpc_xprt_ops xs_tcp_ops = {
2641 	.reserve_xprt		= xprt_reserve_xprt,
2642 	.release_xprt		= xprt_release_xprt,
2643 	.alloc_slot		= xprt_alloc_slot,
2644 	.free_slot		= xprt_free_slot,
2645 	.rpcbind		= rpcb_getport_async,
2646 	.set_port		= xs_set_port,
2647 	.connect		= xs_connect,
2648 	.buf_alloc		= rpc_malloc,
2649 	.buf_free		= rpc_free,
2650 	.prepare_request	= xs_stream_prepare_request,
2651 	.send_request		= xs_tcp_send_request,
2652 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2653 	.close			= xs_tcp_shutdown,
2654 	.destroy		= xs_destroy,
2655 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2656 	.print_stats		= xs_tcp_print_stats,
2657 	.enable_swap		= xs_enable_swap,
2658 	.disable_swap		= xs_disable_swap,
2659 	.inject_disconnect	= xs_inject_disconnect,
2660 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2661 	.bc_setup		= xprt_setup_bc,
2662 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2663 	.bc_num_slots		= xprt_bc_max_slots,
2664 	.bc_free_rqst		= xprt_free_bc_rqst,
2665 	.bc_destroy		= xprt_destroy_bc,
2666 #endif
2667 };
2668 
2669 /*
2670  * The rpc_xprt_ops for the server backchannel
2671  */
2672 
2673 static const struct rpc_xprt_ops bc_tcp_ops = {
2674 	.reserve_xprt		= xprt_reserve_xprt,
2675 	.release_xprt		= xprt_release_xprt,
2676 	.alloc_slot		= xprt_alloc_slot,
2677 	.free_slot		= xprt_free_slot,
2678 	.buf_alloc		= bc_malloc,
2679 	.buf_free		= bc_free,
2680 	.send_request		= bc_send_request,
2681 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2682 	.close			= bc_close,
2683 	.destroy		= bc_destroy,
2684 	.print_stats		= xs_tcp_print_stats,
2685 	.enable_swap		= xs_enable_swap,
2686 	.disable_swap		= xs_disable_swap,
2687 	.inject_disconnect	= xs_inject_disconnect,
2688 };
2689 
2690 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2691 {
2692 	static const struct sockaddr_in sin = {
2693 		.sin_family		= AF_INET,
2694 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2695 	};
2696 	static const struct sockaddr_in6 sin6 = {
2697 		.sin6_family		= AF_INET6,
2698 		.sin6_addr		= IN6ADDR_ANY_INIT,
2699 	};
2700 
2701 	switch (family) {
2702 	case AF_LOCAL:
2703 		break;
2704 	case AF_INET:
2705 		memcpy(sap, &sin, sizeof(sin));
2706 		break;
2707 	case AF_INET6:
2708 		memcpy(sap, &sin6, sizeof(sin6));
2709 		break;
2710 	default:
2711 		dprintk("RPC:       %s: Bad address family\n", __func__);
2712 		return -EAFNOSUPPORT;
2713 	}
2714 	return 0;
2715 }
2716 
2717 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2718 				      unsigned int slot_table_size,
2719 				      unsigned int max_slot_table_size)
2720 {
2721 	struct rpc_xprt *xprt;
2722 	struct sock_xprt *new;
2723 
2724 	if (args->addrlen > sizeof(xprt->addr)) {
2725 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2726 		return ERR_PTR(-EBADF);
2727 	}
2728 
2729 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2730 			max_slot_table_size);
2731 	if (xprt == NULL) {
2732 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2733 				"rpc_xprt\n");
2734 		return ERR_PTR(-ENOMEM);
2735 	}
2736 
2737 	new = container_of(xprt, struct sock_xprt, xprt);
2738 	mutex_init(&new->recv_mutex);
2739 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2740 	xprt->addrlen = args->addrlen;
2741 	if (args->srcaddr)
2742 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2743 	else {
2744 		int err;
2745 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2746 					(struct sockaddr *)&new->srcaddr);
2747 		if (err != 0) {
2748 			xprt_free(xprt);
2749 			return ERR_PTR(err);
2750 		}
2751 	}
2752 
2753 	return xprt;
2754 }
2755 
2756 static const struct rpc_timeout xs_local_default_timeout = {
2757 	.to_initval = 10 * HZ,
2758 	.to_maxval = 10 * HZ,
2759 	.to_retries = 2,
2760 };
2761 
2762 /**
2763  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2764  * @args: rpc transport creation arguments
2765  *
2766  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2767  */
2768 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2769 {
2770 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2771 	struct sock_xprt *transport;
2772 	struct rpc_xprt *xprt;
2773 	struct rpc_xprt *ret;
2774 
2775 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2776 			xprt_max_tcp_slot_table_entries);
2777 	if (IS_ERR(xprt))
2778 		return xprt;
2779 	transport = container_of(xprt, struct sock_xprt, xprt);
2780 
2781 	xprt->prot = 0;
2782 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2783 
2784 	xprt->bind_timeout = XS_BIND_TO;
2785 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2786 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2787 
2788 	xprt->ops = &xs_local_ops;
2789 	xprt->timeout = &xs_local_default_timeout;
2790 
2791 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2792 	INIT_WORK(&transport->error_worker, xs_error_handle);
2793 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2794 
2795 	switch (sun->sun_family) {
2796 	case AF_LOCAL:
2797 		if (sun->sun_path[0] != '/') {
2798 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2799 					sun->sun_path);
2800 			ret = ERR_PTR(-EINVAL);
2801 			goto out_err;
2802 		}
2803 		xprt_set_bound(xprt);
2804 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2805 		ret = ERR_PTR(xs_local_setup_socket(transport));
2806 		if (ret)
2807 			goto out_err;
2808 		break;
2809 	default:
2810 		ret = ERR_PTR(-EAFNOSUPPORT);
2811 		goto out_err;
2812 	}
2813 
2814 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2815 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2816 
2817 	if (try_module_get(THIS_MODULE))
2818 		return xprt;
2819 	ret = ERR_PTR(-EINVAL);
2820 out_err:
2821 	xs_xprt_free(xprt);
2822 	return ret;
2823 }
2824 
2825 static const struct rpc_timeout xs_udp_default_timeout = {
2826 	.to_initval = 5 * HZ,
2827 	.to_maxval = 30 * HZ,
2828 	.to_increment = 5 * HZ,
2829 	.to_retries = 5,
2830 };
2831 
2832 /**
2833  * xs_setup_udp - Set up transport to use a UDP socket
2834  * @args: rpc transport creation arguments
2835  *
2836  */
2837 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2838 {
2839 	struct sockaddr *addr = args->dstaddr;
2840 	struct rpc_xprt *xprt;
2841 	struct sock_xprt *transport;
2842 	struct rpc_xprt *ret;
2843 
2844 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2845 			xprt_udp_slot_table_entries);
2846 	if (IS_ERR(xprt))
2847 		return xprt;
2848 	transport = container_of(xprt, struct sock_xprt, xprt);
2849 
2850 	xprt->prot = IPPROTO_UDP;
2851 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2852 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2853 
2854 	xprt->bind_timeout = XS_BIND_TO;
2855 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2856 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2857 
2858 	xprt->ops = &xs_udp_ops;
2859 
2860 	xprt->timeout = &xs_udp_default_timeout;
2861 
2862 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2863 	INIT_WORK(&transport->error_worker, xs_error_handle);
2864 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2865 
2866 	switch (addr->sa_family) {
2867 	case AF_INET:
2868 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2869 			xprt_set_bound(xprt);
2870 
2871 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2872 		break;
2873 	case AF_INET6:
2874 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2875 			xprt_set_bound(xprt);
2876 
2877 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2878 		break;
2879 	default:
2880 		ret = ERR_PTR(-EAFNOSUPPORT);
2881 		goto out_err;
2882 	}
2883 
2884 	if (xprt_bound(xprt))
2885 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2886 				xprt->address_strings[RPC_DISPLAY_ADDR],
2887 				xprt->address_strings[RPC_DISPLAY_PORT],
2888 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2889 	else
2890 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2891 				xprt->address_strings[RPC_DISPLAY_ADDR],
2892 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2893 
2894 	if (try_module_get(THIS_MODULE))
2895 		return xprt;
2896 	ret = ERR_PTR(-EINVAL);
2897 out_err:
2898 	xs_xprt_free(xprt);
2899 	return ret;
2900 }
2901 
2902 static const struct rpc_timeout xs_tcp_default_timeout = {
2903 	.to_initval = 60 * HZ,
2904 	.to_maxval = 60 * HZ,
2905 	.to_retries = 2,
2906 };
2907 
2908 /**
2909  * xs_setup_tcp - Set up transport to use a TCP socket
2910  * @args: rpc transport creation arguments
2911  *
2912  */
2913 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2914 {
2915 	struct sockaddr *addr = args->dstaddr;
2916 	struct rpc_xprt *xprt;
2917 	struct sock_xprt *transport;
2918 	struct rpc_xprt *ret;
2919 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2920 
2921 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2922 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2923 
2924 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2925 			max_slot_table_size);
2926 	if (IS_ERR(xprt))
2927 		return xprt;
2928 	transport = container_of(xprt, struct sock_xprt, xprt);
2929 
2930 	xprt->prot = IPPROTO_TCP;
2931 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2932 
2933 	xprt->bind_timeout = XS_BIND_TO;
2934 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2935 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2936 
2937 	xprt->ops = &xs_tcp_ops;
2938 	xprt->timeout = &xs_tcp_default_timeout;
2939 
2940 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2941 	xprt->connect_timeout = xprt->timeout->to_initval *
2942 		(xprt->timeout->to_retries + 1);
2943 
2944 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2945 	INIT_WORK(&transport->error_worker, xs_error_handle);
2946 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2947 
2948 	switch (addr->sa_family) {
2949 	case AF_INET:
2950 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2951 			xprt_set_bound(xprt);
2952 
2953 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2954 		break;
2955 	case AF_INET6:
2956 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2957 			xprt_set_bound(xprt);
2958 
2959 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2960 		break;
2961 	default:
2962 		ret = ERR_PTR(-EAFNOSUPPORT);
2963 		goto out_err;
2964 	}
2965 
2966 	if (xprt_bound(xprt))
2967 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2968 				xprt->address_strings[RPC_DISPLAY_ADDR],
2969 				xprt->address_strings[RPC_DISPLAY_PORT],
2970 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2971 	else
2972 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2973 				xprt->address_strings[RPC_DISPLAY_ADDR],
2974 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2975 
2976 	if (try_module_get(THIS_MODULE))
2977 		return xprt;
2978 	ret = ERR_PTR(-EINVAL);
2979 out_err:
2980 	xs_xprt_free(xprt);
2981 	return ret;
2982 }
2983 
2984 /**
2985  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2986  * @args: rpc transport creation arguments
2987  *
2988  */
2989 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2990 {
2991 	struct sockaddr *addr = args->dstaddr;
2992 	struct rpc_xprt *xprt;
2993 	struct sock_xprt *transport;
2994 	struct svc_sock *bc_sock;
2995 	struct rpc_xprt *ret;
2996 
2997 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2998 			xprt_tcp_slot_table_entries);
2999 	if (IS_ERR(xprt))
3000 		return xprt;
3001 	transport = container_of(xprt, struct sock_xprt, xprt);
3002 
3003 	xprt->prot = IPPROTO_TCP;
3004 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3005 	xprt->timeout = &xs_tcp_default_timeout;
3006 
3007 	/* backchannel */
3008 	xprt_set_bound(xprt);
3009 	xprt->bind_timeout = 0;
3010 	xprt->reestablish_timeout = 0;
3011 	xprt->idle_timeout = 0;
3012 
3013 	xprt->ops = &bc_tcp_ops;
3014 
3015 	switch (addr->sa_family) {
3016 	case AF_INET:
3017 		xs_format_peer_addresses(xprt, "tcp",
3018 					 RPCBIND_NETID_TCP);
3019 		break;
3020 	case AF_INET6:
3021 		xs_format_peer_addresses(xprt, "tcp",
3022 				   RPCBIND_NETID_TCP6);
3023 		break;
3024 	default:
3025 		ret = ERR_PTR(-EAFNOSUPPORT);
3026 		goto out_err;
3027 	}
3028 
3029 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3030 			xprt->address_strings[RPC_DISPLAY_ADDR],
3031 			xprt->address_strings[RPC_DISPLAY_PORT],
3032 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3033 
3034 	/*
3035 	 * Once we've associated a backchannel xprt with a connection,
3036 	 * we want to keep it around as long as the connection lasts,
3037 	 * in case we need to start using it for a backchannel again;
3038 	 * this reference won't be dropped until bc_xprt is destroyed.
3039 	 */
3040 	xprt_get(xprt);
3041 	args->bc_xprt->xpt_bc_xprt = xprt;
3042 	xprt->bc_xprt = args->bc_xprt;
3043 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3044 	transport->sock = bc_sock->sk_sock;
3045 	transport->inet = bc_sock->sk_sk;
3046 
3047 	/*
3048 	 * Since we don't want connections for the backchannel, we set
3049 	 * the xprt status to connected
3050 	 */
3051 	xprt_set_connected(xprt);
3052 
3053 	if (try_module_get(THIS_MODULE))
3054 		return xprt;
3055 
3056 	args->bc_xprt->xpt_bc_xprt = NULL;
3057 	args->bc_xprt->xpt_bc_xps = NULL;
3058 	xprt_put(xprt);
3059 	ret = ERR_PTR(-EINVAL);
3060 out_err:
3061 	xs_xprt_free(xprt);
3062 	return ret;
3063 }
3064 
3065 static struct xprt_class	xs_local_transport = {
3066 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3067 	.name		= "named UNIX socket",
3068 	.owner		= THIS_MODULE,
3069 	.ident		= XPRT_TRANSPORT_LOCAL,
3070 	.setup		= xs_setup_local,
3071 	.netid		= { "" },
3072 };
3073 
3074 static struct xprt_class	xs_udp_transport = {
3075 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3076 	.name		= "udp",
3077 	.owner		= THIS_MODULE,
3078 	.ident		= XPRT_TRANSPORT_UDP,
3079 	.setup		= xs_setup_udp,
3080 	.netid		= { "udp", "udp6", "" },
3081 };
3082 
3083 static struct xprt_class	xs_tcp_transport = {
3084 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3085 	.name		= "tcp",
3086 	.owner		= THIS_MODULE,
3087 	.ident		= XPRT_TRANSPORT_TCP,
3088 	.setup		= xs_setup_tcp,
3089 	.netid		= { "tcp", "tcp6", "" },
3090 };
3091 
3092 static struct xprt_class	xs_bc_tcp_transport = {
3093 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3094 	.name		= "tcp NFSv4.1 backchannel",
3095 	.owner		= THIS_MODULE,
3096 	.ident		= XPRT_TRANSPORT_BC_TCP,
3097 	.setup		= xs_setup_bc_tcp,
3098 	.netid		= { "" },
3099 };
3100 
3101 /**
3102  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3103  *
3104  */
3105 int init_socket_xprt(void)
3106 {
3107 	if (!sunrpc_table_header)
3108 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3109 
3110 	xprt_register_transport(&xs_local_transport);
3111 	xprt_register_transport(&xs_udp_transport);
3112 	xprt_register_transport(&xs_tcp_transport);
3113 	xprt_register_transport(&xs_bc_tcp_transport);
3114 
3115 	return 0;
3116 }
3117 
3118 /**
3119  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3120  *
3121  */
3122 void cleanup_socket_xprt(void)
3123 {
3124 	if (sunrpc_table_header) {
3125 		unregister_sysctl_table(sunrpc_table_header);
3126 		sunrpc_table_header = NULL;
3127 	}
3128 
3129 	xprt_unregister_transport(&xs_local_transport);
3130 	xprt_unregister_transport(&xs_udp_transport);
3131 	xprt_unregister_transport(&xs_tcp_transport);
3132 	xprt_unregister_transport(&xs_bc_tcp_transport);
3133 }
3134 
3135 static int param_set_uint_minmax(const char *val,
3136 		const struct kernel_param *kp,
3137 		unsigned int min, unsigned int max)
3138 {
3139 	unsigned int num;
3140 	int ret;
3141 
3142 	if (!val)
3143 		return -EINVAL;
3144 	ret = kstrtouint(val, 0, &num);
3145 	if (ret)
3146 		return ret;
3147 	if (num < min || num > max)
3148 		return -EINVAL;
3149 	*((unsigned int *)kp->arg) = num;
3150 	return 0;
3151 }
3152 
3153 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3154 {
3155 	return param_set_uint_minmax(val, kp,
3156 			RPC_MIN_RESVPORT,
3157 			RPC_MAX_RESVPORT);
3158 }
3159 
3160 static const struct kernel_param_ops param_ops_portnr = {
3161 	.set = param_set_portnr,
3162 	.get = param_get_uint,
3163 };
3164 
3165 #define param_check_portnr(name, p) \
3166 	__param_check(name, p, unsigned int);
3167 
3168 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3169 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3170 
3171 static int param_set_slot_table_size(const char *val,
3172 				     const struct kernel_param *kp)
3173 {
3174 	return param_set_uint_minmax(val, kp,
3175 			RPC_MIN_SLOT_TABLE,
3176 			RPC_MAX_SLOT_TABLE);
3177 }
3178 
3179 static const struct kernel_param_ops param_ops_slot_table_size = {
3180 	.set = param_set_slot_table_size,
3181 	.get = param_get_uint,
3182 };
3183 
3184 #define param_check_slot_table_size(name, p) \
3185 	__param_check(name, p, unsigned int);
3186 
3187 static int param_set_max_slot_table_size(const char *val,
3188 				     const struct kernel_param *kp)
3189 {
3190 	return param_set_uint_minmax(val, kp,
3191 			RPC_MIN_SLOT_TABLE,
3192 			RPC_MAX_SLOT_TABLE_LIMIT);
3193 }
3194 
3195 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3196 	.set = param_set_max_slot_table_size,
3197 	.get = param_get_uint,
3198 };
3199 
3200 #define param_check_max_slot_table_size(name, p) \
3201 	__param_check(name, p, unsigned int);
3202 
3203 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3204 		   slot_table_size, 0644);
3205 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3206 		   max_slot_table_size, 0644);
3207 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3208 		   slot_table_size, 0644);
3209