xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 8b235f2f)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44 
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49 
50 #include <trace/events/sunrpc.h>
51 
52 #include "sunrpc.h"
53 
54 static void xs_close(struct rpc_xprt *xprt);
55 
56 /*
57  * xprtsock tunables
58  */
59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
62 
63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
65 
66 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
67 
68 #define XS_TCP_LINGER_TO	(15U * HZ)
69 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
70 
71 /*
72  * We can register our own files under /proc/sys/sunrpc by
73  * calling register_sysctl_table() again.  The files in that
74  * directory become the union of all files registered there.
75  *
76  * We simply need to make sure that we don't collide with
77  * someone else's file names!
78  */
79 
80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
85 
86 static struct ctl_table_header *sunrpc_table_header;
87 
88 /*
89  * FIXME: changing the UDP slot table size should also resize the UDP
90  *        socket buffers for existing UDP transports
91  */
92 static struct ctl_table xs_tunables_table[] = {
93 	{
94 		.procname	= "udp_slot_table_entries",
95 		.data		= &xprt_udp_slot_table_entries,
96 		.maxlen		= sizeof(unsigned int),
97 		.mode		= 0644,
98 		.proc_handler	= proc_dointvec_minmax,
99 		.extra1		= &min_slot_table_size,
100 		.extra2		= &max_slot_table_size
101 	},
102 	{
103 		.procname	= "tcp_slot_table_entries",
104 		.data		= &xprt_tcp_slot_table_entries,
105 		.maxlen		= sizeof(unsigned int),
106 		.mode		= 0644,
107 		.proc_handler	= proc_dointvec_minmax,
108 		.extra1		= &min_slot_table_size,
109 		.extra2		= &max_slot_table_size
110 	},
111 	{
112 		.procname	= "tcp_max_slot_table_entries",
113 		.data		= &xprt_max_tcp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_tcp_slot_table_limit
119 	},
120 	{
121 		.procname	= "min_resvport",
122 		.data		= &xprt_min_resvport,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &xprt_min_resvport_limit,
127 		.extra2		= &xprt_max_resvport_limit
128 	},
129 	{
130 		.procname	= "max_resvport",
131 		.data		= &xprt_max_resvport,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &xprt_min_resvport_limit,
136 		.extra2		= &xprt_max_resvport_limit
137 	},
138 	{
139 		.procname	= "tcp_fin_timeout",
140 		.data		= &xs_tcp_fin_timeout,
141 		.maxlen		= sizeof(xs_tcp_fin_timeout),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_jiffies,
144 	},
145 	{ },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149 	{
150 		.procname	= "sunrpc",
151 		.mode		= 0555,
152 		.child		= xs_tunables_table
153 	},
154 	{ },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO		(60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO		(2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
180 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
188 
189 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
190 # undef  RPC_DEBUG_DATA
191 # define RPCDBG_FACILITY	RPCDBG_TRANS
192 #endif
193 
194 #ifdef RPC_DEBUG_DATA
195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
196 {
197 	u8 *buf = (u8 *) packet;
198 	int j;
199 
200 	dprintk("RPC:       %s\n", msg);
201 	for (j = 0; j < count && j < 128; j += 4) {
202 		if (!(j & 31)) {
203 			if (j)
204 				dprintk("\n");
205 			dprintk("0x%04x ", j);
206 		}
207 		dprintk("%02x%02x%02x%02x ",
208 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
209 	}
210 	dprintk("\n");
211 }
212 #else
213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
214 {
215 	/* NOP */
216 }
217 #endif
218 
219 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
220 {
221 	return (struct rpc_xprt *) sk->sk_user_data;
222 }
223 
224 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
225 {
226 	return (struct sockaddr *) &xprt->addr;
227 }
228 
229 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
230 {
231 	return (struct sockaddr_un *) &xprt->addr;
232 }
233 
234 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
235 {
236 	return (struct sockaddr_in *) &xprt->addr;
237 }
238 
239 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
240 {
241 	return (struct sockaddr_in6 *) &xprt->addr;
242 }
243 
244 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
245 {
246 	struct sockaddr *sap = xs_addr(xprt);
247 	struct sockaddr_in6 *sin6;
248 	struct sockaddr_in *sin;
249 	struct sockaddr_un *sun;
250 	char buf[128];
251 
252 	switch (sap->sa_family) {
253 	case AF_LOCAL:
254 		sun = xs_addr_un(xprt);
255 		strlcpy(buf, sun->sun_path, sizeof(buf));
256 		xprt->address_strings[RPC_DISPLAY_ADDR] =
257 						kstrdup(buf, GFP_KERNEL);
258 		break;
259 	case AF_INET:
260 		(void)rpc_ntop(sap, buf, sizeof(buf));
261 		xprt->address_strings[RPC_DISPLAY_ADDR] =
262 						kstrdup(buf, GFP_KERNEL);
263 		sin = xs_addr_in(xprt);
264 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
265 		break;
266 	case AF_INET6:
267 		(void)rpc_ntop(sap, buf, sizeof(buf));
268 		xprt->address_strings[RPC_DISPLAY_ADDR] =
269 						kstrdup(buf, GFP_KERNEL);
270 		sin6 = xs_addr_in6(xprt);
271 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
272 		break;
273 	default:
274 		BUG();
275 	}
276 
277 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
278 }
279 
280 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
281 {
282 	struct sockaddr *sap = xs_addr(xprt);
283 	char buf[128];
284 
285 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
286 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
287 
288 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
290 }
291 
292 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
293 				     const char *protocol,
294 				     const char *netid)
295 {
296 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
297 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
298 	xs_format_common_peer_addresses(xprt);
299 	xs_format_common_peer_ports(xprt);
300 }
301 
302 static void xs_update_peer_port(struct rpc_xprt *xprt)
303 {
304 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
305 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
306 
307 	xs_format_common_peer_ports(xprt);
308 }
309 
310 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
311 {
312 	unsigned int i;
313 
314 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
315 		switch (i) {
316 		case RPC_DISPLAY_PROTO:
317 		case RPC_DISPLAY_NETID:
318 			continue;
319 		default:
320 			kfree(xprt->address_strings[i]);
321 		}
322 }
323 
324 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
325 
326 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
327 {
328 	struct msghdr msg = {
329 		.msg_name	= addr,
330 		.msg_namelen	= addrlen,
331 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
332 	};
333 	struct kvec iov = {
334 		.iov_base	= vec->iov_base + base,
335 		.iov_len	= vec->iov_len - base,
336 	};
337 
338 	if (iov.iov_len != 0)
339 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
340 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
341 }
342 
343 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
344 {
345 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
346 			int offset, size_t size, int flags);
347 	struct page **ppage;
348 	unsigned int remainder;
349 	int err;
350 
351 	remainder = xdr->page_len - base;
352 	base += xdr->page_base;
353 	ppage = xdr->pages + (base >> PAGE_SHIFT);
354 	base &= ~PAGE_MASK;
355 	do_sendpage = sock->ops->sendpage;
356 	if (!zerocopy)
357 		do_sendpage = sock_no_sendpage;
358 	for(;;) {
359 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
360 		int flags = XS_SENDMSG_FLAGS;
361 
362 		remainder -= len;
363 		if (remainder != 0 || more)
364 			flags |= MSG_MORE;
365 		err = do_sendpage(sock, *ppage, base, len, flags);
366 		if (remainder == 0 || err != len)
367 			break;
368 		*sent_p += err;
369 		ppage++;
370 		base = 0;
371 	}
372 	if (err > 0) {
373 		*sent_p += err;
374 		err = 0;
375 	}
376 	return err;
377 }
378 
379 /**
380  * xs_sendpages - write pages directly to a socket
381  * @sock: socket to send on
382  * @addr: UDP only -- address of destination
383  * @addrlen: UDP only -- length of destination address
384  * @xdr: buffer containing this request
385  * @base: starting position in the buffer
386  * @zerocopy: true if it is safe to use sendpage()
387  * @sent_p: return the total number of bytes successfully queued for sending
388  *
389  */
390 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
391 {
392 	unsigned int remainder = xdr->len - base;
393 	int err = 0;
394 	int sent = 0;
395 
396 	if (unlikely(!sock))
397 		return -ENOTSOCK;
398 
399 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
400 	if (base != 0) {
401 		addr = NULL;
402 		addrlen = 0;
403 	}
404 
405 	if (base < xdr->head[0].iov_len || addr != NULL) {
406 		unsigned int len = xdr->head[0].iov_len - base;
407 		remainder -= len;
408 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
409 		if (remainder == 0 || err != len)
410 			goto out;
411 		*sent_p += err;
412 		base = 0;
413 	} else
414 		base -= xdr->head[0].iov_len;
415 
416 	if (base < xdr->page_len) {
417 		unsigned int len = xdr->page_len - base;
418 		remainder -= len;
419 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
420 		*sent_p += sent;
421 		if (remainder == 0 || sent != len)
422 			goto out;
423 		base = 0;
424 	} else
425 		base -= xdr->page_len;
426 
427 	if (base >= xdr->tail[0].iov_len)
428 		return 0;
429 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
430 out:
431 	if (err > 0) {
432 		*sent_p += err;
433 		err = 0;
434 	}
435 	return err;
436 }
437 
438 static void xs_nospace_callback(struct rpc_task *task)
439 {
440 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
441 
442 	transport->inet->sk_write_pending--;
443 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
444 }
445 
446 /**
447  * xs_nospace - place task on wait queue if transmit was incomplete
448  * @task: task to put to sleep
449  *
450  */
451 static int xs_nospace(struct rpc_task *task)
452 {
453 	struct rpc_rqst *req = task->tk_rqstp;
454 	struct rpc_xprt *xprt = req->rq_xprt;
455 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
456 	struct sock *sk = transport->inet;
457 	int ret = -EAGAIN;
458 
459 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
460 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
461 			req->rq_slen);
462 
463 	/* Protect against races with write_space */
464 	spin_lock_bh(&xprt->transport_lock);
465 
466 	/* Don't race with disconnect */
467 	if (xprt_connected(xprt)) {
468 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
469 			/*
470 			 * Notify TCP that we're limited by the application
471 			 * window size
472 			 */
473 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
474 			sk->sk_write_pending++;
475 			/* ...and wait for more buffer space */
476 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
477 		}
478 	} else {
479 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
480 		ret = -ENOTCONN;
481 	}
482 
483 	spin_unlock_bh(&xprt->transport_lock);
484 
485 	/* Race breaker in case memory is freed before above code is called */
486 	sk->sk_write_space(sk);
487 	return ret;
488 }
489 
490 /*
491  * Construct a stream transport record marker in @buf.
492  */
493 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
494 {
495 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
496 	rpc_fraghdr *base = buf->head[0].iov_base;
497 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
498 }
499 
500 /**
501  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
502  * @task: RPC task that manages the state of an RPC request
503  *
504  * Return values:
505  *        0:	The request has been sent
506  *   EAGAIN:	The socket was blocked, please call again later to
507  *		complete the request
508  * ENOTCONN:	Caller needs to invoke connect logic then call again
509  *    other:	Some other error occured, the request was not sent
510  */
511 static int xs_local_send_request(struct rpc_task *task)
512 {
513 	struct rpc_rqst *req = task->tk_rqstp;
514 	struct rpc_xprt *xprt = req->rq_xprt;
515 	struct sock_xprt *transport =
516 				container_of(xprt, struct sock_xprt, xprt);
517 	struct xdr_buf *xdr = &req->rq_snd_buf;
518 	int status;
519 	int sent = 0;
520 
521 	xs_encode_stream_record_marker(&req->rq_snd_buf);
522 
523 	xs_pktdump("packet data:",
524 			req->rq_svec->iov_base, req->rq_svec->iov_len);
525 
526 	status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
527 			      true, &sent);
528 	dprintk("RPC:       %s(%u) = %d\n",
529 			__func__, xdr->len - req->rq_bytes_sent, status);
530 
531 	if (status == -EAGAIN && sock_writeable(transport->inet))
532 		status = -ENOBUFS;
533 
534 	if (likely(sent > 0) || status == 0) {
535 		req->rq_bytes_sent += sent;
536 		req->rq_xmit_bytes_sent += sent;
537 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
538 			req->rq_bytes_sent = 0;
539 			return 0;
540 		}
541 		status = -EAGAIN;
542 	}
543 
544 	switch (status) {
545 	case -ENOBUFS:
546 		break;
547 	case -EAGAIN:
548 		status = xs_nospace(task);
549 		break;
550 	default:
551 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
552 			-status);
553 	case -EPIPE:
554 		xs_close(xprt);
555 		status = -ENOTCONN;
556 	}
557 
558 	return status;
559 }
560 
561 /**
562  * xs_udp_send_request - write an RPC request to a UDP socket
563  * @task: address of RPC task that manages the state of an RPC request
564  *
565  * Return values:
566  *        0:	The request has been sent
567  *   EAGAIN:	The socket was blocked, please call again later to
568  *		complete the request
569  * ENOTCONN:	Caller needs to invoke connect logic then call again
570  *    other:	Some other error occurred, the request was not sent
571  */
572 static int xs_udp_send_request(struct rpc_task *task)
573 {
574 	struct rpc_rqst *req = task->tk_rqstp;
575 	struct rpc_xprt *xprt = req->rq_xprt;
576 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
577 	struct xdr_buf *xdr = &req->rq_snd_buf;
578 	int sent = 0;
579 	int status;
580 
581 	xs_pktdump("packet data:",
582 				req->rq_svec->iov_base,
583 				req->rq_svec->iov_len);
584 
585 	if (!xprt_bound(xprt))
586 		return -ENOTCONN;
587 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
588 			      xdr, req->rq_bytes_sent, true, &sent);
589 
590 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
591 			xdr->len - req->rq_bytes_sent, status);
592 
593 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
594 	if (status == -EPERM)
595 		goto process_status;
596 
597 	if (status == -EAGAIN && sock_writeable(transport->inet))
598 		status = -ENOBUFS;
599 
600 	if (sent > 0 || status == 0) {
601 		req->rq_xmit_bytes_sent += sent;
602 		if (sent >= req->rq_slen)
603 			return 0;
604 		/* Still some bytes left; set up for a retry later. */
605 		status = -EAGAIN;
606 	}
607 
608 process_status:
609 	switch (status) {
610 	case -ENOTSOCK:
611 		status = -ENOTCONN;
612 		/* Should we call xs_close() here? */
613 		break;
614 	case -EAGAIN:
615 		status = xs_nospace(task);
616 		break;
617 	default:
618 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
619 			-status);
620 	case -ENETUNREACH:
621 	case -ENOBUFS:
622 	case -EPIPE:
623 	case -ECONNREFUSED:
624 	case -EPERM:
625 		/* When the server has died, an ICMP port unreachable message
626 		 * prompts ECONNREFUSED. */
627 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
628 	}
629 
630 	return status;
631 }
632 
633 /**
634  * xs_tcp_send_request - write an RPC request to a TCP socket
635  * @task: address of RPC task that manages the state of an RPC request
636  *
637  * Return values:
638  *        0:	The request has been sent
639  *   EAGAIN:	The socket was blocked, please call again later to
640  *		complete the request
641  * ENOTCONN:	Caller needs to invoke connect logic then call again
642  *    other:	Some other error occurred, the request was not sent
643  *
644  * XXX: In the case of soft timeouts, should we eventually give up
645  *	if sendmsg is not able to make progress?
646  */
647 static int xs_tcp_send_request(struct rpc_task *task)
648 {
649 	struct rpc_rqst *req = task->tk_rqstp;
650 	struct rpc_xprt *xprt = req->rq_xprt;
651 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
652 	struct xdr_buf *xdr = &req->rq_snd_buf;
653 	bool zerocopy = true;
654 	int status;
655 	int sent;
656 
657 	xs_encode_stream_record_marker(&req->rq_snd_buf);
658 
659 	xs_pktdump("packet data:",
660 				req->rq_svec->iov_base,
661 				req->rq_svec->iov_len);
662 	/* Don't use zero copy if this is a resend. If the RPC call
663 	 * completes while the socket holds a reference to the pages,
664 	 * then we may end up resending corrupted data.
665 	 */
666 	if (task->tk_flags & RPC_TASK_SENT)
667 		zerocopy = false;
668 
669 	/* Continue transmitting the packet/record. We must be careful
670 	 * to cope with writespace callbacks arriving _after_ we have
671 	 * called sendmsg(). */
672 	while (1) {
673 		sent = 0;
674 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
675 				      req->rq_bytes_sent, zerocopy, &sent);
676 
677 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
678 				xdr->len - req->rq_bytes_sent, status);
679 
680 		/* If we've sent the entire packet, immediately
681 		 * reset the count of bytes sent. */
682 		req->rq_bytes_sent += sent;
683 		req->rq_xmit_bytes_sent += sent;
684 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
685 			req->rq_bytes_sent = 0;
686 			return 0;
687 		}
688 
689 		if (status < 0)
690 			break;
691 		if (sent == 0) {
692 			status = -EAGAIN;
693 			break;
694 		}
695 	}
696 	if (status == -EAGAIN && sk_stream_is_writeable(transport->inet))
697 		status = -ENOBUFS;
698 
699 	switch (status) {
700 	case -ENOTSOCK:
701 		status = -ENOTCONN;
702 		/* Should we call xs_close() here? */
703 		break;
704 	case -EAGAIN:
705 		status = xs_nospace(task);
706 		break;
707 	default:
708 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
709 			-status);
710 	case -ECONNRESET:
711 	case -ECONNREFUSED:
712 	case -ENOTCONN:
713 	case -EADDRINUSE:
714 	case -ENOBUFS:
715 	case -EPIPE:
716 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
717 	}
718 
719 	return status;
720 }
721 
722 /**
723  * xs_tcp_release_xprt - clean up after a tcp transmission
724  * @xprt: transport
725  * @task: rpc task
726  *
727  * This cleans up if an error causes us to abort the transmission of a request.
728  * In this case, the socket may need to be reset in order to avoid confusing
729  * the server.
730  */
731 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
732 {
733 	struct rpc_rqst *req;
734 
735 	if (task != xprt->snd_task)
736 		return;
737 	if (task == NULL)
738 		goto out_release;
739 	req = task->tk_rqstp;
740 	if (req == NULL)
741 		goto out_release;
742 	if (req->rq_bytes_sent == 0)
743 		goto out_release;
744 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
745 		goto out_release;
746 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
747 out_release:
748 	xprt_release_xprt(xprt, task);
749 }
750 
751 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
752 {
753 	transport->old_data_ready = sk->sk_data_ready;
754 	transport->old_state_change = sk->sk_state_change;
755 	transport->old_write_space = sk->sk_write_space;
756 	transport->old_error_report = sk->sk_error_report;
757 }
758 
759 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
760 {
761 	sk->sk_data_ready = transport->old_data_ready;
762 	sk->sk_state_change = transport->old_state_change;
763 	sk->sk_write_space = transport->old_write_space;
764 	sk->sk_error_report = transport->old_error_report;
765 }
766 
767 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
768 {
769 	smp_mb__before_atomic();
770 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
771 	clear_bit(XPRT_CLOSING, &xprt->state);
772 	smp_mb__after_atomic();
773 }
774 
775 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
776 {
777 	xs_sock_reset_connection_flags(xprt);
778 	/* Mark transport as closed and wake up all pending tasks */
779 	xprt_disconnect_done(xprt);
780 	xprt_force_disconnect(xprt);
781 }
782 
783 /**
784  * xs_error_report - callback to handle TCP socket state errors
785  * @sk: socket
786  *
787  * Note: we don't call sock_error() since there may be a rpc_task
788  * using the socket, and so we don't want to clear sk->sk_err.
789  */
790 static void xs_error_report(struct sock *sk)
791 {
792 	struct rpc_xprt *xprt;
793 	int err;
794 
795 	read_lock_bh(&sk->sk_callback_lock);
796 	if (!(xprt = xprt_from_sock(sk)))
797 		goto out;
798 
799 	err = -sk->sk_err;
800 	if (err == 0)
801 		goto out;
802 	/* Is this a reset event? */
803 	if (sk->sk_state == TCP_CLOSE)
804 		xs_sock_mark_closed(xprt);
805 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
806 			xprt, -err);
807 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
808 	xprt_wake_pending_tasks(xprt, err);
809  out:
810 	read_unlock_bh(&sk->sk_callback_lock);
811 }
812 
813 static void xs_reset_transport(struct sock_xprt *transport)
814 {
815 	struct socket *sock = transport->sock;
816 	struct sock *sk = transport->inet;
817 	struct rpc_xprt *xprt = &transport->xprt;
818 
819 	if (sk == NULL)
820 		return;
821 
822 	if (atomic_read(&transport->xprt.swapper))
823 		sk_clear_memalloc(sk);
824 
825 	kernel_sock_shutdown(sock, SHUT_RDWR);
826 
827 	write_lock_bh(&sk->sk_callback_lock);
828 	transport->inet = NULL;
829 	transport->sock = NULL;
830 
831 	sk->sk_user_data = NULL;
832 
833 	xs_restore_old_callbacks(transport, sk);
834 	xprt_clear_connected(xprt);
835 	write_unlock_bh(&sk->sk_callback_lock);
836 	xs_sock_reset_connection_flags(xprt);
837 
838 	trace_rpc_socket_close(xprt, sock);
839 	sock_release(sock);
840 }
841 
842 /**
843  * xs_close - close a socket
844  * @xprt: transport
845  *
846  * This is used when all requests are complete; ie, no DRC state remains
847  * on the server we want to save.
848  *
849  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
850  * xs_reset_transport() zeroing the socket from underneath a writer.
851  */
852 static void xs_close(struct rpc_xprt *xprt)
853 {
854 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
855 
856 	dprintk("RPC:       xs_close xprt %p\n", xprt);
857 
858 	xs_reset_transport(transport);
859 	xprt->reestablish_timeout = 0;
860 
861 	xprt_disconnect_done(xprt);
862 }
863 
864 static void xs_inject_disconnect(struct rpc_xprt *xprt)
865 {
866 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
867 		xprt);
868 	xprt_disconnect_done(xprt);
869 }
870 
871 static void xs_xprt_free(struct rpc_xprt *xprt)
872 {
873 	xs_free_peer_addresses(xprt);
874 	xprt_free(xprt);
875 }
876 
877 /**
878  * xs_destroy - prepare to shutdown a transport
879  * @xprt: doomed transport
880  *
881  */
882 static void xs_destroy(struct rpc_xprt *xprt)
883 {
884 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
885 
886 	xs_close(xprt);
887 	xs_xprt_free(xprt);
888 	module_put(THIS_MODULE);
889 }
890 
891 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
892 {
893 	struct xdr_skb_reader desc = {
894 		.skb		= skb,
895 		.offset		= sizeof(rpc_fraghdr),
896 		.count		= skb->len - sizeof(rpc_fraghdr),
897 	};
898 
899 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
900 		return -1;
901 	if (desc.count)
902 		return -1;
903 	return 0;
904 }
905 
906 /**
907  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
908  * @sk: socket with data to read
909  *
910  * Currently this assumes we can read the whole reply in a single gulp.
911  */
912 static void xs_local_data_ready(struct sock *sk)
913 {
914 	struct rpc_task *task;
915 	struct rpc_xprt *xprt;
916 	struct rpc_rqst *rovr;
917 	struct sk_buff *skb;
918 	int err, repsize, copied;
919 	u32 _xid;
920 	__be32 *xp;
921 
922 	read_lock_bh(&sk->sk_callback_lock);
923 	dprintk("RPC:       %s...\n", __func__);
924 	xprt = xprt_from_sock(sk);
925 	if (xprt == NULL)
926 		goto out;
927 
928 	skb = skb_recv_datagram(sk, 0, 1, &err);
929 	if (skb == NULL)
930 		goto out;
931 
932 	repsize = skb->len - sizeof(rpc_fraghdr);
933 	if (repsize < 4) {
934 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
935 		goto dropit;
936 	}
937 
938 	/* Copy the XID from the skb... */
939 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
940 	if (xp == NULL)
941 		goto dropit;
942 
943 	/* Look up and lock the request corresponding to the given XID */
944 	spin_lock(&xprt->transport_lock);
945 	rovr = xprt_lookup_rqst(xprt, *xp);
946 	if (!rovr)
947 		goto out_unlock;
948 	task = rovr->rq_task;
949 
950 	copied = rovr->rq_private_buf.buflen;
951 	if (copied > repsize)
952 		copied = repsize;
953 
954 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
955 		dprintk("RPC:       sk_buff copy failed\n");
956 		goto out_unlock;
957 	}
958 
959 	xprt_complete_rqst(task, copied);
960 
961  out_unlock:
962 	spin_unlock(&xprt->transport_lock);
963  dropit:
964 	skb_free_datagram(sk, skb);
965  out:
966 	read_unlock_bh(&sk->sk_callback_lock);
967 }
968 
969 /**
970  * xs_udp_data_ready - "data ready" callback for UDP sockets
971  * @sk: socket with data to read
972  *
973  */
974 static void xs_udp_data_ready(struct sock *sk)
975 {
976 	struct rpc_task *task;
977 	struct rpc_xprt *xprt;
978 	struct rpc_rqst *rovr;
979 	struct sk_buff *skb;
980 	int err, repsize, copied;
981 	u32 _xid;
982 	__be32 *xp;
983 
984 	read_lock_bh(&sk->sk_callback_lock);
985 	dprintk("RPC:       xs_udp_data_ready...\n");
986 	if (!(xprt = xprt_from_sock(sk)))
987 		goto out;
988 
989 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
990 		goto out;
991 
992 	repsize = skb->len - sizeof(struct udphdr);
993 	if (repsize < 4) {
994 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
995 		goto dropit;
996 	}
997 
998 	/* Copy the XID from the skb... */
999 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
1000 				sizeof(_xid), &_xid);
1001 	if (xp == NULL)
1002 		goto dropit;
1003 
1004 	/* Look up and lock the request corresponding to the given XID */
1005 	spin_lock(&xprt->transport_lock);
1006 	rovr = xprt_lookup_rqst(xprt, *xp);
1007 	if (!rovr)
1008 		goto out_unlock;
1009 	task = rovr->rq_task;
1010 
1011 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1012 		copied = repsize;
1013 
1014 	/* Suck it into the iovec, verify checksum if not done by hw. */
1015 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1016 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1017 		goto out_unlock;
1018 	}
1019 
1020 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1021 
1022 	xprt_adjust_cwnd(xprt, task, copied);
1023 	xprt_complete_rqst(task, copied);
1024 
1025  out_unlock:
1026 	spin_unlock(&xprt->transport_lock);
1027  dropit:
1028 	skb_free_datagram(sk, skb);
1029  out:
1030 	read_unlock_bh(&sk->sk_callback_lock);
1031 }
1032 
1033 /*
1034  * Helper function to force a TCP close if the server is sending
1035  * junk and/or it has put us in CLOSE_WAIT
1036  */
1037 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1038 {
1039 	xprt_force_disconnect(xprt);
1040 }
1041 
1042 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1043 {
1044 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1045 	size_t len, used;
1046 	char *p;
1047 
1048 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1049 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1050 	used = xdr_skb_read_bits(desc, p, len);
1051 	transport->tcp_offset += used;
1052 	if (used != len)
1053 		return;
1054 
1055 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1056 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1057 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1058 	else
1059 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1060 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1061 
1062 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1063 	transport->tcp_offset = 0;
1064 
1065 	/* Sanity check of the record length */
1066 	if (unlikely(transport->tcp_reclen < 8)) {
1067 		dprintk("RPC:       invalid TCP record fragment length\n");
1068 		xs_tcp_force_close(xprt);
1069 		return;
1070 	}
1071 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1072 			transport->tcp_reclen);
1073 }
1074 
1075 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1076 {
1077 	if (transport->tcp_offset == transport->tcp_reclen) {
1078 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1079 		transport->tcp_offset = 0;
1080 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1081 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1082 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1083 			transport->tcp_copied = 0;
1084 		}
1085 	}
1086 }
1087 
1088 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1089 {
1090 	size_t len, used;
1091 	char *p;
1092 
1093 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1094 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1095 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1096 	used = xdr_skb_read_bits(desc, p, len);
1097 	transport->tcp_offset += used;
1098 	if (used != len)
1099 		return;
1100 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1101 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1102 	transport->tcp_copied = 4;
1103 	dprintk("RPC:       reading %s XID %08x\n",
1104 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1105 							      : "request with",
1106 			ntohl(transport->tcp_xid));
1107 	xs_tcp_check_fraghdr(transport);
1108 }
1109 
1110 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1111 				       struct xdr_skb_reader *desc)
1112 {
1113 	size_t len, used;
1114 	u32 offset;
1115 	char *p;
1116 
1117 	/*
1118 	 * We want transport->tcp_offset to be 8 at the end of this routine
1119 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1120 	 * When this function is called for the first time,
1121 	 * transport->tcp_offset is 4 (after having already read the xid).
1122 	 */
1123 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1124 	len = sizeof(transport->tcp_calldir) - offset;
1125 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1126 	p = ((char *) &transport->tcp_calldir) + offset;
1127 	used = xdr_skb_read_bits(desc, p, len);
1128 	transport->tcp_offset += used;
1129 	if (used != len)
1130 		return;
1131 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1132 	/*
1133 	 * We don't yet have the XDR buffer, so we will write the calldir
1134 	 * out after we get the buffer from the 'struct rpc_rqst'
1135 	 */
1136 	switch (ntohl(transport->tcp_calldir)) {
1137 	case RPC_REPLY:
1138 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1139 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1140 		transport->tcp_flags |= TCP_RPC_REPLY;
1141 		break;
1142 	case RPC_CALL:
1143 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1144 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1145 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1146 		break;
1147 	default:
1148 		dprintk("RPC:       invalid request message type\n");
1149 		xs_tcp_force_close(&transport->xprt);
1150 	}
1151 	xs_tcp_check_fraghdr(transport);
1152 }
1153 
1154 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1155 				     struct xdr_skb_reader *desc,
1156 				     struct rpc_rqst *req)
1157 {
1158 	struct sock_xprt *transport =
1159 				container_of(xprt, struct sock_xprt, xprt);
1160 	struct xdr_buf *rcvbuf;
1161 	size_t len;
1162 	ssize_t r;
1163 
1164 	rcvbuf = &req->rq_private_buf;
1165 
1166 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1167 		/*
1168 		 * Save the RPC direction in the XDR buffer
1169 		 */
1170 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1171 			&transport->tcp_calldir,
1172 			sizeof(transport->tcp_calldir));
1173 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1174 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1175 	}
1176 
1177 	len = desc->count;
1178 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1179 		struct xdr_skb_reader my_desc;
1180 
1181 		len = transport->tcp_reclen - transport->tcp_offset;
1182 		memcpy(&my_desc, desc, sizeof(my_desc));
1183 		my_desc.count = len;
1184 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1185 					  &my_desc, xdr_skb_read_bits);
1186 		desc->count -= r;
1187 		desc->offset += r;
1188 	} else
1189 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1190 					  desc, xdr_skb_read_bits);
1191 
1192 	if (r > 0) {
1193 		transport->tcp_copied += r;
1194 		transport->tcp_offset += r;
1195 	}
1196 	if (r != len) {
1197 		/* Error when copying to the receive buffer,
1198 		 * usually because we weren't able to allocate
1199 		 * additional buffer pages. All we can do now
1200 		 * is turn off TCP_RCV_COPY_DATA, so the request
1201 		 * will not receive any additional updates,
1202 		 * and time out.
1203 		 * Any remaining data from this record will
1204 		 * be discarded.
1205 		 */
1206 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1207 		dprintk("RPC:       XID %08x truncated request\n",
1208 				ntohl(transport->tcp_xid));
1209 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1210 				"tcp_offset = %u, tcp_reclen = %u\n",
1211 				xprt, transport->tcp_copied,
1212 				transport->tcp_offset, transport->tcp_reclen);
1213 		return;
1214 	}
1215 
1216 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1217 			ntohl(transport->tcp_xid), r);
1218 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1219 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1220 			transport->tcp_offset, transport->tcp_reclen);
1221 
1222 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1223 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1224 	else if (transport->tcp_offset == transport->tcp_reclen) {
1225 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1226 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1227 	}
1228 }
1229 
1230 /*
1231  * Finds the request corresponding to the RPC xid and invokes the common
1232  * tcp read code to read the data.
1233  */
1234 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1235 				    struct xdr_skb_reader *desc)
1236 {
1237 	struct sock_xprt *transport =
1238 				container_of(xprt, struct sock_xprt, xprt);
1239 	struct rpc_rqst *req;
1240 
1241 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1242 
1243 	/* Find and lock the request corresponding to this xid */
1244 	spin_lock(&xprt->transport_lock);
1245 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1246 	if (!req) {
1247 		dprintk("RPC:       XID %08x request not found!\n",
1248 				ntohl(transport->tcp_xid));
1249 		spin_unlock(&xprt->transport_lock);
1250 		return -1;
1251 	}
1252 
1253 	xs_tcp_read_common(xprt, desc, req);
1254 
1255 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1256 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1257 
1258 	spin_unlock(&xprt->transport_lock);
1259 	return 0;
1260 }
1261 
1262 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1263 /*
1264  * Obtains an rpc_rqst previously allocated and invokes the common
1265  * tcp read code to read the data.  The result is placed in the callback
1266  * queue.
1267  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1268  * connection and return -1.
1269  */
1270 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1271 				       struct xdr_skb_reader *desc)
1272 {
1273 	struct sock_xprt *transport =
1274 				container_of(xprt, struct sock_xprt, xprt);
1275 	struct rpc_rqst *req;
1276 
1277 	/* Look up and lock the request corresponding to the given XID */
1278 	spin_lock(&xprt->transport_lock);
1279 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1280 	if (req == NULL) {
1281 		spin_unlock(&xprt->transport_lock);
1282 		printk(KERN_WARNING "Callback slot table overflowed\n");
1283 		xprt_force_disconnect(xprt);
1284 		return -1;
1285 	}
1286 
1287 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1288 	xs_tcp_read_common(xprt, desc, req);
1289 
1290 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1291 		xprt_complete_bc_request(req, transport->tcp_copied);
1292 	spin_unlock(&xprt->transport_lock);
1293 
1294 	return 0;
1295 }
1296 
1297 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1298 					struct xdr_skb_reader *desc)
1299 {
1300 	struct sock_xprt *transport =
1301 				container_of(xprt, struct sock_xprt, xprt);
1302 
1303 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1304 		xs_tcp_read_reply(xprt, desc) :
1305 		xs_tcp_read_callback(xprt, desc);
1306 }
1307 #else
1308 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1309 					struct xdr_skb_reader *desc)
1310 {
1311 	return xs_tcp_read_reply(xprt, desc);
1312 }
1313 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1314 
1315 /*
1316  * Read data off the transport.  This can be either an RPC_CALL or an
1317  * RPC_REPLY.  Relay the processing to helper functions.
1318  */
1319 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1320 				    struct xdr_skb_reader *desc)
1321 {
1322 	struct sock_xprt *transport =
1323 				container_of(xprt, struct sock_xprt, xprt);
1324 
1325 	if (_xs_tcp_read_data(xprt, desc) == 0)
1326 		xs_tcp_check_fraghdr(transport);
1327 	else {
1328 		/*
1329 		 * The transport_lock protects the request handling.
1330 		 * There's no need to hold it to update the tcp_flags.
1331 		 */
1332 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1333 	}
1334 }
1335 
1336 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1337 {
1338 	size_t len;
1339 
1340 	len = transport->tcp_reclen - transport->tcp_offset;
1341 	if (len > desc->count)
1342 		len = desc->count;
1343 	desc->count -= len;
1344 	desc->offset += len;
1345 	transport->tcp_offset += len;
1346 	dprintk("RPC:       discarded %Zu bytes\n", len);
1347 	xs_tcp_check_fraghdr(transport);
1348 }
1349 
1350 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1351 {
1352 	struct rpc_xprt *xprt = rd_desc->arg.data;
1353 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1354 	struct xdr_skb_reader desc = {
1355 		.skb	= skb,
1356 		.offset	= offset,
1357 		.count	= len,
1358 	};
1359 
1360 	dprintk("RPC:       xs_tcp_data_recv started\n");
1361 	do {
1362 		trace_xs_tcp_data_recv(transport);
1363 		/* Read in a new fragment marker if necessary */
1364 		/* Can we ever really expect to get completely empty fragments? */
1365 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1366 			xs_tcp_read_fraghdr(xprt, &desc);
1367 			continue;
1368 		}
1369 		/* Read in the xid if necessary */
1370 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1371 			xs_tcp_read_xid(transport, &desc);
1372 			continue;
1373 		}
1374 		/* Read in the call/reply flag */
1375 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1376 			xs_tcp_read_calldir(transport, &desc);
1377 			continue;
1378 		}
1379 		/* Read in the request data */
1380 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1381 			xs_tcp_read_data(xprt, &desc);
1382 			continue;
1383 		}
1384 		/* Skip over any trailing bytes on short reads */
1385 		xs_tcp_read_discard(transport, &desc);
1386 	} while (desc.count);
1387 	trace_xs_tcp_data_recv(transport);
1388 	dprintk("RPC:       xs_tcp_data_recv done\n");
1389 	return len - desc.count;
1390 }
1391 
1392 /**
1393  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1394  * @sk: socket with data to read
1395  *
1396  */
1397 static void xs_tcp_data_ready(struct sock *sk)
1398 {
1399 	struct rpc_xprt *xprt;
1400 	read_descriptor_t rd_desc;
1401 	int read;
1402 	unsigned long total = 0;
1403 
1404 	dprintk("RPC:       xs_tcp_data_ready...\n");
1405 
1406 	read_lock_bh(&sk->sk_callback_lock);
1407 	if (!(xprt = xprt_from_sock(sk))) {
1408 		read = 0;
1409 		goto out;
1410 	}
1411 	/* Any data means we had a useful conversation, so
1412 	 * the we don't need to delay the next reconnect
1413 	 */
1414 	if (xprt->reestablish_timeout)
1415 		xprt->reestablish_timeout = 0;
1416 
1417 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1418 	rd_desc.arg.data = xprt;
1419 	do {
1420 		rd_desc.count = 65536;
1421 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1422 		if (read > 0)
1423 			total += read;
1424 	} while (read > 0);
1425 out:
1426 	trace_xs_tcp_data_ready(xprt, read, total);
1427 	read_unlock_bh(&sk->sk_callback_lock);
1428 }
1429 
1430 /**
1431  * xs_tcp_state_change - callback to handle TCP socket state changes
1432  * @sk: socket whose state has changed
1433  *
1434  */
1435 static void xs_tcp_state_change(struct sock *sk)
1436 {
1437 	struct rpc_xprt *xprt;
1438 
1439 	read_lock_bh(&sk->sk_callback_lock);
1440 	if (!(xprt = xprt_from_sock(sk)))
1441 		goto out;
1442 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1443 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1444 			sk->sk_state, xprt_connected(xprt),
1445 			sock_flag(sk, SOCK_DEAD),
1446 			sock_flag(sk, SOCK_ZAPPED),
1447 			sk->sk_shutdown);
1448 
1449 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1450 	switch (sk->sk_state) {
1451 	case TCP_ESTABLISHED:
1452 		spin_lock(&xprt->transport_lock);
1453 		if (!xprt_test_and_set_connected(xprt)) {
1454 			struct sock_xprt *transport = container_of(xprt,
1455 					struct sock_xprt, xprt);
1456 
1457 			/* Reset TCP record info */
1458 			transport->tcp_offset = 0;
1459 			transport->tcp_reclen = 0;
1460 			transport->tcp_copied = 0;
1461 			transport->tcp_flags =
1462 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1463 			xprt->connect_cookie++;
1464 
1465 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1466 		}
1467 		spin_unlock(&xprt->transport_lock);
1468 		break;
1469 	case TCP_FIN_WAIT1:
1470 		/* The client initiated a shutdown of the socket */
1471 		xprt->connect_cookie++;
1472 		xprt->reestablish_timeout = 0;
1473 		set_bit(XPRT_CLOSING, &xprt->state);
1474 		smp_mb__before_atomic();
1475 		clear_bit(XPRT_CONNECTED, &xprt->state);
1476 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1477 		smp_mb__after_atomic();
1478 		break;
1479 	case TCP_CLOSE_WAIT:
1480 		/* The server initiated a shutdown of the socket */
1481 		xprt->connect_cookie++;
1482 		clear_bit(XPRT_CONNECTED, &xprt->state);
1483 		xs_tcp_force_close(xprt);
1484 	case TCP_CLOSING:
1485 		/*
1486 		 * If the server closed down the connection, make sure that
1487 		 * we back off before reconnecting
1488 		 */
1489 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1490 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1491 		break;
1492 	case TCP_LAST_ACK:
1493 		set_bit(XPRT_CLOSING, &xprt->state);
1494 		smp_mb__before_atomic();
1495 		clear_bit(XPRT_CONNECTED, &xprt->state);
1496 		smp_mb__after_atomic();
1497 		break;
1498 	case TCP_CLOSE:
1499 		xs_sock_mark_closed(xprt);
1500 	}
1501  out:
1502 	read_unlock_bh(&sk->sk_callback_lock);
1503 }
1504 
1505 static void xs_write_space(struct sock *sk)
1506 {
1507 	struct socket *sock;
1508 	struct rpc_xprt *xprt;
1509 
1510 	if (unlikely(!(sock = sk->sk_socket)))
1511 		return;
1512 	clear_bit(SOCK_NOSPACE, &sock->flags);
1513 
1514 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1515 		return;
1516 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1517 		return;
1518 
1519 	xprt_write_space(xprt);
1520 }
1521 
1522 /**
1523  * xs_udp_write_space - callback invoked when socket buffer space
1524  *                             becomes available
1525  * @sk: socket whose state has changed
1526  *
1527  * Called when more output buffer space is available for this socket.
1528  * We try not to wake our writers until they can make "significant"
1529  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1530  * with a bunch of small requests.
1531  */
1532 static void xs_udp_write_space(struct sock *sk)
1533 {
1534 	read_lock_bh(&sk->sk_callback_lock);
1535 
1536 	/* from net/core/sock.c:sock_def_write_space */
1537 	if (sock_writeable(sk))
1538 		xs_write_space(sk);
1539 
1540 	read_unlock_bh(&sk->sk_callback_lock);
1541 }
1542 
1543 /**
1544  * xs_tcp_write_space - callback invoked when socket buffer space
1545  *                             becomes available
1546  * @sk: socket whose state has changed
1547  *
1548  * Called when more output buffer space is available for this socket.
1549  * We try not to wake our writers until they can make "significant"
1550  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1551  * with a bunch of small requests.
1552  */
1553 static void xs_tcp_write_space(struct sock *sk)
1554 {
1555 	read_lock_bh(&sk->sk_callback_lock);
1556 
1557 	/* from net/core/stream.c:sk_stream_write_space */
1558 	if (sk_stream_is_writeable(sk))
1559 		xs_write_space(sk);
1560 
1561 	read_unlock_bh(&sk->sk_callback_lock);
1562 }
1563 
1564 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1565 {
1566 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1567 	struct sock *sk = transport->inet;
1568 
1569 	if (transport->rcvsize) {
1570 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1571 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1572 	}
1573 	if (transport->sndsize) {
1574 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1575 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1576 		sk->sk_write_space(sk);
1577 	}
1578 }
1579 
1580 /**
1581  * xs_udp_set_buffer_size - set send and receive limits
1582  * @xprt: generic transport
1583  * @sndsize: requested size of send buffer, in bytes
1584  * @rcvsize: requested size of receive buffer, in bytes
1585  *
1586  * Set socket send and receive buffer size limits.
1587  */
1588 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1589 {
1590 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1591 
1592 	transport->sndsize = 0;
1593 	if (sndsize)
1594 		transport->sndsize = sndsize + 1024;
1595 	transport->rcvsize = 0;
1596 	if (rcvsize)
1597 		transport->rcvsize = rcvsize + 1024;
1598 
1599 	xs_udp_do_set_buffer_size(xprt);
1600 }
1601 
1602 /**
1603  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1604  * @task: task that timed out
1605  *
1606  * Adjust the congestion window after a retransmit timeout has occurred.
1607  */
1608 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1609 {
1610 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1611 }
1612 
1613 static unsigned short xs_get_random_port(void)
1614 {
1615 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1616 	unsigned short rand = (unsigned short) prandom_u32() % range;
1617 	return rand + xprt_min_resvport;
1618 }
1619 
1620 /**
1621  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1622  * @sock: socket
1623  *
1624  * Note that this function has to be called on all sockets that share the
1625  * same port, and it must be called before binding.
1626  */
1627 static void xs_sock_set_reuseport(struct socket *sock)
1628 {
1629 	int opt = 1;
1630 
1631 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1632 			(char *)&opt, sizeof(opt));
1633 }
1634 
1635 static unsigned short xs_sock_getport(struct socket *sock)
1636 {
1637 	struct sockaddr_storage buf;
1638 	int buflen;
1639 	unsigned short port = 0;
1640 
1641 	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1642 		goto out;
1643 	switch (buf.ss_family) {
1644 	case AF_INET6:
1645 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1646 		break;
1647 	case AF_INET:
1648 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1649 	}
1650 out:
1651 	return port;
1652 }
1653 
1654 /**
1655  * xs_set_port - reset the port number in the remote endpoint address
1656  * @xprt: generic transport
1657  * @port: new port number
1658  *
1659  */
1660 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1661 {
1662 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1663 
1664 	rpc_set_port(xs_addr(xprt), port);
1665 	xs_update_peer_port(xprt);
1666 }
1667 
1668 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1669 {
1670 	if (transport->srcport == 0)
1671 		transport->srcport = xs_sock_getport(sock);
1672 }
1673 
1674 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1675 {
1676 	unsigned short port = transport->srcport;
1677 
1678 	if (port == 0 && transport->xprt.resvport)
1679 		port = xs_get_random_port();
1680 	return port;
1681 }
1682 
1683 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1684 {
1685 	if (transport->srcport != 0)
1686 		transport->srcport = 0;
1687 	if (!transport->xprt.resvport)
1688 		return 0;
1689 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1690 		return xprt_max_resvport;
1691 	return --port;
1692 }
1693 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1694 {
1695 	struct sockaddr_storage myaddr;
1696 	int err, nloop = 0;
1697 	unsigned short port = xs_get_srcport(transport);
1698 	unsigned short last;
1699 
1700 	/*
1701 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1702 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1703 	 * port selection happen implicitly when the socket is used
1704 	 * (for example at connect time).
1705 	 *
1706 	 * This ensures that we can continue to establish TCP
1707 	 * connections even when all local ephemeral ports are already
1708 	 * a part of some TCP connection.  This makes no difference
1709 	 * for UDP sockets, but also doens't harm them.
1710 	 *
1711 	 * If we're asking for any reserved port (i.e. port == 0 &&
1712 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1713 	 * ensure that port is non-zero and we will bind as needed.
1714 	 */
1715 	if (port == 0)
1716 		return 0;
1717 
1718 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1719 	do {
1720 		rpc_set_port((struct sockaddr *)&myaddr, port);
1721 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1722 				transport->xprt.addrlen);
1723 		if (err == 0) {
1724 			transport->srcport = port;
1725 			break;
1726 		}
1727 		last = port;
1728 		port = xs_next_srcport(transport, port);
1729 		if (port > last)
1730 			nloop++;
1731 	} while (err == -EADDRINUSE && nloop != 2);
1732 
1733 	if (myaddr.ss_family == AF_INET)
1734 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1735 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1736 				port, err ? "failed" : "ok", err);
1737 	else
1738 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1739 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1740 				port, err ? "failed" : "ok", err);
1741 	return err;
1742 }
1743 
1744 /*
1745  * We don't support autobind on AF_LOCAL sockets
1746  */
1747 static void xs_local_rpcbind(struct rpc_task *task)
1748 {
1749 	rcu_read_lock();
1750 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1751 	rcu_read_unlock();
1752 }
1753 
1754 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1755 {
1756 }
1757 
1758 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1759 static struct lock_class_key xs_key[2];
1760 static struct lock_class_key xs_slock_key[2];
1761 
1762 static inline void xs_reclassify_socketu(struct socket *sock)
1763 {
1764 	struct sock *sk = sock->sk;
1765 
1766 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1767 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1768 }
1769 
1770 static inline void xs_reclassify_socket4(struct socket *sock)
1771 {
1772 	struct sock *sk = sock->sk;
1773 
1774 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1775 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1776 }
1777 
1778 static inline void xs_reclassify_socket6(struct socket *sock)
1779 {
1780 	struct sock *sk = sock->sk;
1781 
1782 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1783 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1784 }
1785 
1786 static inline void xs_reclassify_socket(int family, struct socket *sock)
1787 {
1788 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1789 	if (sock_owned_by_user(sock->sk))
1790 		return;
1791 
1792 	switch (family) {
1793 	case AF_LOCAL:
1794 		xs_reclassify_socketu(sock);
1795 		break;
1796 	case AF_INET:
1797 		xs_reclassify_socket4(sock);
1798 		break;
1799 	case AF_INET6:
1800 		xs_reclassify_socket6(sock);
1801 		break;
1802 	}
1803 }
1804 #else
1805 static inline void xs_reclassify_socketu(struct socket *sock)
1806 {
1807 }
1808 
1809 static inline void xs_reclassify_socket4(struct socket *sock)
1810 {
1811 }
1812 
1813 static inline void xs_reclassify_socket6(struct socket *sock)
1814 {
1815 }
1816 
1817 static inline void xs_reclassify_socket(int family, struct socket *sock)
1818 {
1819 }
1820 #endif
1821 
1822 static void xs_dummy_setup_socket(struct work_struct *work)
1823 {
1824 }
1825 
1826 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1827 		struct sock_xprt *transport, int family, int type,
1828 		int protocol, bool reuseport)
1829 {
1830 	struct socket *sock;
1831 	int err;
1832 
1833 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1834 	if (err < 0) {
1835 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1836 				protocol, -err);
1837 		goto out;
1838 	}
1839 	xs_reclassify_socket(family, sock);
1840 
1841 	if (reuseport)
1842 		xs_sock_set_reuseport(sock);
1843 
1844 	err = xs_bind(transport, sock);
1845 	if (err) {
1846 		sock_release(sock);
1847 		goto out;
1848 	}
1849 
1850 	return sock;
1851 out:
1852 	return ERR_PTR(err);
1853 }
1854 
1855 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1856 				      struct socket *sock)
1857 {
1858 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1859 									xprt);
1860 
1861 	if (!transport->inet) {
1862 		struct sock *sk = sock->sk;
1863 
1864 		write_lock_bh(&sk->sk_callback_lock);
1865 
1866 		xs_save_old_callbacks(transport, sk);
1867 
1868 		sk->sk_user_data = xprt;
1869 		sk->sk_data_ready = xs_local_data_ready;
1870 		sk->sk_write_space = xs_udp_write_space;
1871 		sk->sk_error_report = xs_error_report;
1872 		sk->sk_allocation = GFP_NOIO;
1873 
1874 		xprt_clear_connected(xprt);
1875 
1876 		/* Reset to new socket */
1877 		transport->sock = sock;
1878 		transport->inet = sk;
1879 
1880 		write_unlock_bh(&sk->sk_callback_lock);
1881 	}
1882 
1883 	/* Tell the socket layer to start connecting... */
1884 	xprt->stat.connect_count++;
1885 	xprt->stat.connect_start = jiffies;
1886 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1887 }
1888 
1889 /**
1890  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1891  * @transport: socket transport to connect
1892  */
1893 static int xs_local_setup_socket(struct sock_xprt *transport)
1894 {
1895 	struct rpc_xprt *xprt = &transport->xprt;
1896 	struct socket *sock;
1897 	int status = -EIO;
1898 
1899 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1900 					SOCK_STREAM, 0, &sock, 1);
1901 	if (status < 0) {
1902 		dprintk("RPC:       can't create AF_LOCAL "
1903 			"transport socket (%d).\n", -status);
1904 		goto out;
1905 	}
1906 	xs_reclassify_socketu(sock);
1907 
1908 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1909 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1910 
1911 	status = xs_local_finish_connecting(xprt, sock);
1912 	trace_rpc_socket_connect(xprt, sock, status);
1913 	switch (status) {
1914 	case 0:
1915 		dprintk("RPC:       xprt %p connected to %s\n",
1916 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1917 		xprt_set_connected(xprt);
1918 	case -ENOBUFS:
1919 		break;
1920 	case -ENOENT:
1921 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1922 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1923 		break;
1924 	case -ECONNREFUSED:
1925 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1926 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1927 		break;
1928 	default:
1929 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1930 				__func__, -status,
1931 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1932 	}
1933 
1934 out:
1935 	xprt_clear_connecting(xprt);
1936 	xprt_wake_pending_tasks(xprt, status);
1937 	return status;
1938 }
1939 
1940 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1941 {
1942 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1943 	int ret;
1944 
1945 	 if (RPC_IS_ASYNC(task)) {
1946 		/*
1947 		 * We want the AF_LOCAL connect to be resolved in the
1948 		 * filesystem namespace of the process making the rpc
1949 		 * call.  Thus we connect synchronously.
1950 		 *
1951 		 * If we want to support asynchronous AF_LOCAL calls,
1952 		 * we'll need to figure out how to pass a namespace to
1953 		 * connect.
1954 		 */
1955 		rpc_exit(task, -ENOTCONN);
1956 		return;
1957 	}
1958 	ret = xs_local_setup_socket(transport);
1959 	if (ret && !RPC_IS_SOFTCONN(task))
1960 		msleep_interruptible(15000);
1961 }
1962 
1963 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1964 /*
1965  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1966  * know that we have exclusive access to the socket), to guard against
1967  * races with xs_reset_transport.
1968  */
1969 static void xs_set_memalloc(struct rpc_xprt *xprt)
1970 {
1971 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1972 			xprt);
1973 
1974 	/*
1975 	 * If there's no sock, then we have nothing to set. The
1976 	 * reconnecting process will get it for us.
1977 	 */
1978 	if (!transport->inet)
1979 		return;
1980 	if (atomic_read(&xprt->swapper))
1981 		sk_set_memalloc(transport->inet);
1982 }
1983 
1984 /**
1985  * xs_enable_swap - Tag this transport as being used for swap.
1986  * @xprt: transport to tag
1987  *
1988  * Take a reference to this transport on behalf of the rpc_clnt, and
1989  * optionally mark it for swapping if it wasn't already.
1990  */
1991 static int
1992 xs_enable_swap(struct rpc_xprt *xprt)
1993 {
1994 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1995 
1996 	if (atomic_inc_return(&xprt->swapper) != 1)
1997 		return 0;
1998 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1999 		return -ERESTARTSYS;
2000 	if (xs->inet)
2001 		sk_set_memalloc(xs->inet);
2002 	xprt_release_xprt(xprt, NULL);
2003 	return 0;
2004 }
2005 
2006 /**
2007  * xs_disable_swap - Untag this transport as being used for swap.
2008  * @xprt: transport to tag
2009  *
2010  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2011  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2012  */
2013 static void
2014 xs_disable_swap(struct rpc_xprt *xprt)
2015 {
2016 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2017 
2018 	if (!atomic_dec_and_test(&xprt->swapper))
2019 		return;
2020 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2021 		return;
2022 	if (xs->inet)
2023 		sk_clear_memalloc(xs->inet);
2024 	xprt_release_xprt(xprt, NULL);
2025 }
2026 #else
2027 static void xs_set_memalloc(struct rpc_xprt *xprt)
2028 {
2029 }
2030 
2031 static int
2032 xs_enable_swap(struct rpc_xprt *xprt)
2033 {
2034 	return -EINVAL;
2035 }
2036 
2037 static void
2038 xs_disable_swap(struct rpc_xprt *xprt)
2039 {
2040 }
2041 #endif
2042 
2043 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2044 {
2045 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2046 
2047 	if (!transport->inet) {
2048 		struct sock *sk = sock->sk;
2049 
2050 		write_lock_bh(&sk->sk_callback_lock);
2051 
2052 		xs_save_old_callbacks(transport, sk);
2053 
2054 		sk->sk_user_data = xprt;
2055 		sk->sk_data_ready = xs_udp_data_ready;
2056 		sk->sk_write_space = xs_udp_write_space;
2057 		sk->sk_allocation = GFP_NOIO;
2058 
2059 		xprt_set_connected(xprt);
2060 
2061 		/* Reset to new socket */
2062 		transport->sock = sock;
2063 		transport->inet = sk;
2064 
2065 		xs_set_memalloc(xprt);
2066 
2067 		write_unlock_bh(&sk->sk_callback_lock);
2068 	}
2069 	xs_udp_do_set_buffer_size(xprt);
2070 }
2071 
2072 static void xs_udp_setup_socket(struct work_struct *work)
2073 {
2074 	struct sock_xprt *transport =
2075 		container_of(work, struct sock_xprt, connect_worker.work);
2076 	struct rpc_xprt *xprt = &transport->xprt;
2077 	struct socket *sock = transport->sock;
2078 	int status = -EIO;
2079 
2080 	sock = xs_create_sock(xprt, transport,
2081 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2082 			IPPROTO_UDP, false);
2083 	if (IS_ERR(sock))
2084 		goto out;
2085 
2086 	dprintk("RPC:       worker connecting xprt %p via %s to "
2087 				"%s (port %s)\n", xprt,
2088 			xprt->address_strings[RPC_DISPLAY_PROTO],
2089 			xprt->address_strings[RPC_DISPLAY_ADDR],
2090 			xprt->address_strings[RPC_DISPLAY_PORT]);
2091 
2092 	xs_udp_finish_connecting(xprt, sock);
2093 	trace_rpc_socket_connect(xprt, sock, 0);
2094 	status = 0;
2095 out:
2096 	xprt_unlock_connect(xprt, transport);
2097 	xprt_clear_connecting(xprt);
2098 	xprt_wake_pending_tasks(xprt, status);
2099 }
2100 
2101 /**
2102  * xs_tcp_shutdown - gracefully shut down a TCP socket
2103  * @xprt: transport
2104  *
2105  * Initiates a graceful shutdown of the TCP socket by calling the
2106  * equivalent of shutdown(SHUT_RDWR);
2107  */
2108 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2109 {
2110 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2111 	struct socket *sock = transport->sock;
2112 
2113 	if (sock == NULL)
2114 		return;
2115 	if (xprt_connected(xprt)) {
2116 		kernel_sock_shutdown(sock, SHUT_RDWR);
2117 		trace_rpc_socket_shutdown(xprt, sock);
2118 	} else
2119 		xs_reset_transport(transport);
2120 }
2121 
2122 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2123 {
2124 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2125 	int ret = -ENOTCONN;
2126 
2127 	if (!transport->inet) {
2128 		struct sock *sk = sock->sk;
2129 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2130 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2131 		unsigned int opt_on = 1;
2132 		unsigned int timeo;
2133 
2134 		/* TCP Keepalive options */
2135 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2136 				(char *)&opt_on, sizeof(opt_on));
2137 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2138 				(char *)&keepidle, sizeof(keepidle));
2139 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2140 				(char *)&keepidle, sizeof(keepidle));
2141 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2142 				(char *)&keepcnt, sizeof(keepcnt));
2143 
2144 		/* TCP user timeout (see RFC5482) */
2145 		timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2146 			(xprt->timeout->to_retries + 1);
2147 		kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2148 				(char *)&timeo, sizeof(timeo));
2149 
2150 		write_lock_bh(&sk->sk_callback_lock);
2151 
2152 		xs_save_old_callbacks(transport, sk);
2153 
2154 		sk->sk_user_data = xprt;
2155 		sk->sk_data_ready = xs_tcp_data_ready;
2156 		sk->sk_state_change = xs_tcp_state_change;
2157 		sk->sk_write_space = xs_tcp_write_space;
2158 		sk->sk_error_report = xs_error_report;
2159 		sk->sk_allocation = GFP_NOIO;
2160 
2161 		/* socket options */
2162 		sock_reset_flag(sk, SOCK_LINGER);
2163 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2164 
2165 		xprt_clear_connected(xprt);
2166 
2167 		/* Reset to new socket */
2168 		transport->sock = sock;
2169 		transport->inet = sk;
2170 
2171 		write_unlock_bh(&sk->sk_callback_lock);
2172 	}
2173 
2174 	if (!xprt_bound(xprt))
2175 		goto out;
2176 
2177 	xs_set_memalloc(xprt);
2178 
2179 	/* Tell the socket layer to start connecting... */
2180 	xprt->stat.connect_count++;
2181 	xprt->stat.connect_start = jiffies;
2182 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2183 	switch (ret) {
2184 	case 0:
2185 		xs_set_srcport(transport, sock);
2186 	case -EINPROGRESS:
2187 		/* SYN_SENT! */
2188 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2189 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2190 	}
2191 out:
2192 	return ret;
2193 }
2194 
2195 /**
2196  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2197  *
2198  * Invoked by a work queue tasklet.
2199  */
2200 static void xs_tcp_setup_socket(struct work_struct *work)
2201 {
2202 	struct sock_xprt *transport =
2203 		container_of(work, struct sock_xprt, connect_worker.work);
2204 	struct socket *sock = transport->sock;
2205 	struct rpc_xprt *xprt = &transport->xprt;
2206 	int status = -EIO;
2207 
2208 	if (!sock) {
2209 		sock = xs_create_sock(xprt, transport,
2210 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2211 				IPPROTO_TCP, true);
2212 		if (IS_ERR(sock)) {
2213 			status = PTR_ERR(sock);
2214 			goto out;
2215 		}
2216 	}
2217 
2218 	dprintk("RPC:       worker connecting xprt %p via %s to "
2219 				"%s (port %s)\n", xprt,
2220 			xprt->address_strings[RPC_DISPLAY_PROTO],
2221 			xprt->address_strings[RPC_DISPLAY_ADDR],
2222 			xprt->address_strings[RPC_DISPLAY_PORT]);
2223 
2224 	status = xs_tcp_finish_connecting(xprt, sock);
2225 	trace_rpc_socket_connect(xprt, sock, status);
2226 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2227 			xprt, -status, xprt_connected(xprt),
2228 			sock->sk->sk_state);
2229 	switch (status) {
2230 	default:
2231 		printk("%s: connect returned unhandled error %d\n",
2232 			__func__, status);
2233 	case -EADDRNOTAVAIL:
2234 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2235 		 * and retry
2236 		 */
2237 		xs_tcp_force_close(xprt);
2238 		break;
2239 	case 0:
2240 	case -EINPROGRESS:
2241 	case -EALREADY:
2242 		xprt_unlock_connect(xprt, transport);
2243 		xprt_clear_connecting(xprt);
2244 		return;
2245 	case -EINVAL:
2246 		/* Happens, for instance, if the user specified a link
2247 		 * local IPv6 address without a scope-id.
2248 		 */
2249 	case -ECONNREFUSED:
2250 	case -ECONNRESET:
2251 	case -ENETUNREACH:
2252 	case -EADDRINUSE:
2253 	case -ENOBUFS:
2254 		/* retry with existing socket, after a delay */
2255 		xs_tcp_force_close(xprt);
2256 		goto out;
2257 	}
2258 	status = -EAGAIN;
2259 out:
2260 	xprt_unlock_connect(xprt, transport);
2261 	xprt_clear_connecting(xprt);
2262 	xprt_wake_pending_tasks(xprt, status);
2263 }
2264 
2265 /**
2266  * xs_connect - connect a socket to a remote endpoint
2267  * @xprt: pointer to transport structure
2268  * @task: address of RPC task that manages state of connect request
2269  *
2270  * TCP: If the remote end dropped the connection, delay reconnecting.
2271  *
2272  * UDP socket connects are synchronous, but we use a work queue anyway
2273  * to guarantee that even unprivileged user processes can set up a
2274  * socket on a privileged port.
2275  *
2276  * If a UDP socket connect fails, the delay behavior here prevents
2277  * retry floods (hard mounts).
2278  */
2279 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2280 {
2281 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2282 
2283 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2284 
2285 	if (transport->sock != NULL) {
2286 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2287 				"seconds\n",
2288 				xprt, xprt->reestablish_timeout / HZ);
2289 
2290 		/* Start by resetting any existing state */
2291 		xs_reset_transport(transport);
2292 
2293 		queue_delayed_work(rpciod_workqueue,
2294 				   &transport->connect_worker,
2295 				   xprt->reestablish_timeout);
2296 		xprt->reestablish_timeout <<= 1;
2297 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2298 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2299 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2300 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2301 	} else {
2302 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2303 		queue_delayed_work(rpciod_workqueue,
2304 				   &transport->connect_worker, 0);
2305 	}
2306 }
2307 
2308 /**
2309  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2310  * @xprt: rpc_xprt struct containing statistics
2311  * @seq: output file
2312  *
2313  */
2314 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2315 {
2316 	long idle_time = 0;
2317 
2318 	if (xprt_connected(xprt))
2319 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2320 
2321 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2322 			"%llu %llu %lu %llu %llu\n",
2323 			xprt->stat.bind_count,
2324 			xprt->stat.connect_count,
2325 			xprt->stat.connect_time,
2326 			idle_time,
2327 			xprt->stat.sends,
2328 			xprt->stat.recvs,
2329 			xprt->stat.bad_xids,
2330 			xprt->stat.req_u,
2331 			xprt->stat.bklog_u,
2332 			xprt->stat.max_slots,
2333 			xprt->stat.sending_u,
2334 			xprt->stat.pending_u);
2335 }
2336 
2337 /**
2338  * xs_udp_print_stats - display UDP socket-specifc stats
2339  * @xprt: rpc_xprt struct containing statistics
2340  * @seq: output file
2341  *
2342  */
2343 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2344 {
2345 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2346 
2347 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2348 			"%lu %llu %llu\n",
2349 			transport->srcport,
2350 			xprt->stat.bind_count,
2351 			xprt->stat.sends,
2352 			xprt->stat.recvs,
2353 			xprt->stat.bad_xids,
2354 			xprt->stat.req_u,
2355 			xprt->stat.bklog_u,
2356 			xprt->stat.max_slots,
2357 			xprt->stat.sending_u,
2358 			xprt->stat.pending_u);
2359 }
2360 
2361 /**
2362  * xs_tcp_print_stats - display TCP socket-specifc stats
2363  * @xprt: rpc_xprt struct containing statistics
2364  * @seq: output file
2365  *
2366  */
2367 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2368 {
2369 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2370 	long idle_time = 0;
2371 
2372 	if (xprt_connected(xprt))
2373 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2374 
2375 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2376 			"%llu %llu %lu %llu %llu\n",
2377 			transport->srcport,
2378 			xprt->stat.bind_count,
2379 			xprt->stat.connect_count,
2380 			xprt->stat.connect_time,
2381 			idle_time,
2382 			xprt->stat.sends,
2383 			xprt->stat.recvs,
2384 			xprt->stat.bad_xids,
2385 			xprt->stat.req_u,
2386 			xprt->stat.bklog_u,
2387 			xprt->stat.max_slots,
2388 			xprt->stat.sending_u,
2389 			xprt->stat.pending_u);
2390 }
2391 
2392 /*
2393  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2394  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2395  * to use the server side send routines.
2396  */
2397 static void *bc_malloc(struct rpc_task *task, size_t size)
2398 {
2399 	struct page *page;
2400 	struct rpc_buffer *buf;
2401 
2402 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2403 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2404 		return NULL;
2405 
2406 	page = alloc_page(GFP_KERNEL);
2407 	if (!page)
2408 		return NULL;
2409 
2410 	buf = page_address(page);
2411 	buf->len = PAGE_SIZE;
2412 
2413 	return buf->data;
2414 }
2415 
2416 /*
2417  * Free the space allocated in the bc_alloc routine
2418  */
2419 static void bc_free(void *buffer)
2420 {
2421 	struct rpc_buffer *buf;
2422 
2423 	if (!buffer)
2424 		return;
2425 
2426 	buf = container_of(buffer, struct rpc_buffer, data);
2427 	free_page((unsigned long)buf);
2428 }
2429 
2430 /*
2431  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2432  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2433  */
2434 static int bc_sendto(struct rpc_rqst *req)
2435 {
2436 	int len;
2437 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2438 	struct rpc_xprt *xprt = req->rq_xprt;
2439 	struct sock_xprt *transport =
2440 				container_of(xprt, struct sock_xprt, xprt);
2441 	struct socket *sock = transport->sock;
2442 	unsigned long headoff;
2443 	unsigned long tailoff;
2444 
2445 	xs_encode_stream_record_marker(xbufp);
2446 
2447 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2448 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2449 	len = svc_send_common(sock, xbufp,
2450 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2451 			      xbufp->tail[0].iov_base, tailoff);
2452 
2453 	if (len != xbufp->len) {
2454 		printk(KERN_NOTICE "Error sending entire callback!\n");
2455 		len = -EAGAIN;
2456 	}
2457 
2458 	return len;
2459 }
2460 
2461 /*
2462  * The send routine. Borrows from svc_send
2463  */
2464 static int bc_send_request(struct rpc_task *task)
2465 {
2466 	struct rpc_rqst *req = task->tk_rqstp;
2467 	struct svc_xprt	*xprt;
2468 	u32                     len;
2469 
2470 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2471 	/*
2472 	 * Get the server socket associated with this callback xprt
2473 	 */
2474 	xprt = req->rq_xprt->bc_xprt;
2475 
2476 	/*
2477 	 * Grab the mutex to serialize data as the connection is shared
2478 	 * with the fore channel
2479 	 */
2480 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2481 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2482 		if (!mutex_trylock(&xprt->xpt_mutex))
2483 			return -EAGAIN;
2484 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2485 	}
2486 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2487 		len = -ENOTCONN;
2488 	else
2489 		len = bc_sendto(req);
2490 	mutex_unlock(&xprt->xpt_mutex);
2491 
2492 	if (len > 0)
2493 		len = 0;
2494 
2495 	return len;
2496 }
2497 
2498 /*
2499  * The close routine. Since this is client initiated, we do nothing
2500  */
2501 
2502 static void bc_close(struct rpc_xprt *xprt)
2503 {
2504 }
2505 
2506 /*
2507  * The xprt destroy routine. Again, because this connection is client
2508  * initiated, we do nothing
2509  */
2510 
2511 static void bc_destroy(struct rpc_xprt *xprt)
2512 {
2513 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2514 
2515 	xs_xprt_free(xprt);
2516 	module_put(THIS_MODULE);
2517 }
2518 
2519 static struct rpc_xprt_ops xs_local_ops = {
2520 	.reserve_xprt		= xprt_reserve_xprt,
2521 	.release_xprt		= xs_tcp_release_xprt,
2522 	.alloc_slot		= xprt_alloc_slot,
2523 	.rpcbind		= xs_local_rpcbind,
2524 	.set_port		= xs_local_set_port,
2525 	.connect		= xs_local_connect,
2526 	.buf_alloc		= rpc_malloc,
2527 	.buf_free		= rpc_free,
2528 	.send_request		= xs_local_send_request,
2529 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2530 	.close			= xs_close,
2531 	.destroy		= xs_destroy,
2532 	.print_stats		= xs_local_print_stats,
2533 	.enable_swap		= xs_enable_swap,
2534 	.disable_swap		= xs_disable_swap,
2535 };
2536 
2537 static struct rpc_xprt_ops xs_udp_ops = {
2538 	.set_buffer_size	= xs_udp_set_buffer_size,
2539 	.reserve_xprt		= xprt_reserve_xprt_cong,
2540 	.release_xprt		= xprt_release_xprt_cong,
2541 	.alloc_slot		= xprt_alloc_slot,
2542 	.rpcbind		= rpcb_getport_async,
2543 	.set_port		= xs_set_port,
2544 	.connect		= xs_connect,
2545 	.buf_alloc		= rpc_malloc,
2546 	.buf_free		= rpc_free,
2547 	.send_request		= xs_udp_send_request,
2548 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2549 	.timer			= xs_udp_timer,
2550 	.release_request	= xprt_release_rqst_cong,
2551 	.close			= xs_close,
2552 	.destroy		= xs_destroy,
2553 	.print_stats		= xs_udp_print_stats,
2554 	.enable_swap		= xs_enable_swap,
2555 	.disable_swap		= xs_disable_swap,
2556 	.inject_disconnect	= xs_inject_disconnect,
2557 };
2558 
2559 static struct rpc_xprt_ops xs_tcp_ops = {
2560 	.reserve_xprt		= xprt_reserve_xprt,
2561 	.release_xprt		= xs_tcp_release_xprt,
2562 	.alloc_slot		= xprt_lock_and_alloc_slot,
2563 	.rpcbind		= rpcb_getport_async,
2564 	.set_port		= xs_set_port,
2565 	.connect		= xs_connect,
2566 	.buf_alloc		= rpc_malloc,
2567 	.buf_free		= rpc_free,
2568 	.send_request		= xs_tcp_send_request,
2569 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2570 	.close			= xs_tcp_shutdown,
2571 	.destroy		= xs_destroy,
2572 	.print_stats		= xs_tcp_print_stats,
2573 	.enable_swap		= xs_enable_swap,
2574 	.disable_swap		= xs_disable_swap,
2575 	.inject_disconnect	= xs_inject_disconnect,
2576 };
2577 
2578 /*
2579  * The rpc_xprt_ops for the server backchannel
2580  */
2581 
2582 static struct rpc_xprt_ops bc_tcp_ops = {
2583 	.reserve_xprt		= xprt_reserve_xprt,
2584 	.release_xprt		= xprt_release_xprt,
2585 	.alloc_slot		= xprt_alloc_slot,
2586 	.buf_alloc		= bc_malloc,
2587 	.buf_free		= bc_free,
2588 	.send_request		= bc_send_request,
2589 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2590 	.close			= bc_close,
2591 	.destroy		= bc_destroy,
2592 	.print_stats		= xs_tcp_print_stats,
2593 	.enable_swap		= xs_enable_swap,
2594 	.disable_swap		= xs_disable_swap,
2595 	.inject_disconnect	= xs_inject_disconnect,
2596 };
2597 
2598 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2599 {
2600 	static const struct sockaddr_in sin = {
2601 		.sin_family		= AF_INET,
2602 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2603 	};
2604 	static const struct sockaddr_in6 sin6 = {
2605 		.sin6_family		= AF_INET6,
2606 		.sin6_addr		= IN6ADDR_ANY_INIT,
2607 	};
2608 
2609 	switch (family) {
2610 	case AF_LOCAL:
2611 		break;
2612 	case AF_INET:
2613 		memcpy(sap, &sin, sizeof(sin));
2614 		break;
2615 	case AF_INET6:
2616 		memcpy(sap, &sin6, sizeof(sin6));
2617 		break;
2618 	default:
2619 		dprintk("RPC:       %s: Bad address family\n", __func__);
2620 		return -EAFNOSUPPORT;
2621 	}
2622 	return 0;
2623 }
2624 
2625 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2626 				      unsigned int slot_table_size,
2627 				      unsigned int max_slot_table_size)
2628 {
2629 	struct rpc_xprt *xprt;
2630 	struct sock_xprt *new;
2631 
2632 	if (args->addrlen > sizeof(xprt->addr)) {
2633 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2634 		return ERR_PTR(-EBADF);
2635 	}
2636 
2637 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2638 			max_slot_table_size);
2639 	if (xprt == NULL) {
2640 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2641 				"rpc_xprt\n");
2642 		return ERR_PTR(-ENOMEM);
2643 	}
2644 
2645 	new = container_of(xprt, struct sock_xprt, xprt);
2646 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2647 	xprt->addrlen = args->addrlen;
2648 	if (args->srcaddr)
2649 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2650 	else {
2651 		int err;
2652 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2653 					(struct sockaddr *)&new->srcaddr);
2654 		if (err != 0) {
2655 			xprt_free(xprt);
2656 			return ERR_PTR(err);
2657 		}
2658 	}
2659 
2660 	return xprt;
2661 }
2662 
2663 static const struct rpc_timeout xs_local_default_timeout = {
2664 	.to_initval = 10 * HZ,
2665 	.to_maxval = 10 * HZ,
2666 	.to_retries = 2,
2667 };
2668 
2669 /**
2670  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2671  * @args: rpc transport creation arguments
2672  *
2673  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2674  */
2675 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2676 {
2677 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2678 	struct sock_xprt *transport;
2679 	struct rpc_xprt *xprt;
2680 	struct rpc_xprt *ret;
2681 
2682 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2683 			xprt_max_tcp_slot_table_entries);
2684 	if (IS_ERR(xprt))
2685 		return xprt;
2686 	transport = container_of(xprt, struct sock_xprt, xprt);
2687 
2688 	xprt->prot = 0;
2689 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2690 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2691 
2692 	xprt->bind_timeout = XS_BIND_TO;
2693 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2694 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2695 
2696 	xprt->ops = &xs_local_ops;
2697 	xprt->timeout = &xs_local_default_timeout;
2698 
2699 	INIT_DELAYED_WORK(&transport->connect_worker,
2700 			xs_dummy_setup_socket);
2701 
2702 	switch (sun->sun_family) {
2703 	case AF_LOCAL:
2704 		if (sun->sun_path[0] != '/') {
2705 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2706 					sun->sun_path);
2707 			ret = ERR_PTR(-EINVAL);
2708 			goto out_err;
2709 		}
2710 		xprt_set_bound(xprt);
2711 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2712 		ret = ERR_PTR(xs_local_setup_socket(transport));
2713 		if (ret)
2714 			goto out_err;
2715 		break;
2716 	default:
2717 		ret = ERR_PTR(-EAFNOSUPPORT);
2718 		goto out_err;
2719 	}
2720 
2721 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2722 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2723 
2724 	if (try_module_get(THIS_MODULE))
2725 		return xprt;
2726 	ret = ERR_PTR(-EINVAL);
2727 out_err:
2728 	xs_xprt_free(xprt);
2729 	return ret;
2730 }
2731 
2732 static const struct rpc_timeout xs_udp_default_timeout = {
2733 	.to_initval = 5 * HZ,
2734 	.to_maxval = 30 * HZ,
2735 	.to_increment = 5 * HZ,
2736 	.to_retries = 5,
2737 };
2738 
2739 /**
2740  * xs_setup_udp - Set up transport to use a UDP socket
2741  * @args: rpc transport creation arguments
2742  *
2743  */
2744 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2745 {
2746 	struct sockaddr *addr = args->dstaddr;
2747 	struct rpc_xprt *xprt;
2748 	struct sock_xprt *transport;
2749 	struct rpc_xprt *ret;
2750 
2751 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2752 			xprt_udp_slot_table_entries);
2753 	if (IS_ERR(xprt))
2754 		return xprt;
2755 	transport = container_of(xprt, struct sock_xprt, xprt);
2756 
2757 	xprt->prot = IPPROTO_UDP;
2758 	xprt->tsh_size = 0;
2759 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2760 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2761 
2762 	xprt->bind_timeout = XS_BIND_TO;
2763 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2764 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2765 
2766 	xprt->ops = &xs_udp_ops;
2767 
2768 	xprt->timeout = &xs_udp_default_timeout;
2769 
2770 	switch (addr->sa_family) {
2771 	case AF_INET:
2772 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2773 			xprt_set_bound(xprt);
2774 
2775 		INIT_DELAYED_WORK(&transport->connect_worker,
2776 					xs_udp_setup_socket);
2777 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2778 		break;
2779 	case AF_INET6:
2780 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2781 			xprt_set_bound(xprt);
2782 
2783 		INIT_DELAYED_WORK(&transport->connect_worker,
2784 					xs_udp_setup_socket);
2785 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2786 		break;
2787 	default:
2788 		ret = ERR_PTR(-EAFNOSUPPORT);
2789 		goto out_err;
2790 	}
2791 
2792 	if (xprt_bound(xprt))
2793 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2794 				xprt->address_strings[RPC_DISPLAY_ADDR],
2795 				xprt->address_strings[RPC_DISPLAY_PORT],
2796 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2797 	else
2798 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2799 				xprt->address_strings[RPC_DISPLAY_ADDR],
2800 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2801 
2802 	if (try_module_get(THIS_MODULE))
2803 		return xprt;
2804 	ret = ERR_PTR(-EINVAL);
2805 out_err:
2806 	xs_xprt_free(xprt);
2807 	return ret;
2808 }
2809 
2810 static const struct rpc_timeout xs_tcp_default_timeout = {
2811 	.to_initval = 60 * HZ,
2812 	.to_maxval = 60 * HZ,
2813 	.to_retries = 2,
2814 };
2815 
2816 /**
2817  * xs_setup_tcp - Set up transport to use a TCP socket
2818  * @args: rpc transport creation arguments
2819  *
2820  */
2821 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2822 {
2823 	struct sockaddr *addr = args->dstaddr;
2824 	struct rpc_xprt *xprt;
2825 	struct sock_xprt *transport;
2826 	struct rpc_xprt *ret;
2827 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2828 
2829 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2830 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2831 
2832 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2833 			max_slot_table_size);
2834 	if (IS_ERR(xprt))
2835 		return xprt;
2836 	transport = container_of(xprt, struct sock_xprt, xprt);
2837 
2838 	xprt->prot = IPPROTO_TCP;
2839 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2840 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2841 
2842 	xprt->bind_timeout = XS_BIND_TO;
2843 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2844 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2845 
2846 	xprt->ops = &xs_tcp_ops;
2847 	xprt->timeout = &xs_tcp_default_timeout;
2848 
2849 	switch (addr->sa_family) {
2850 	case AF_INET:
2851 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2852 			xprt_set_bound(xprt);
2853 
2854 		INIT_DELAYED_WORK(&transport->connect_worker,
2855 					xs_tcp_setup_socket);
2856 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2857 		break;
2858 	case AF_INET6:
2859 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2860 			xprt_set_bound(xprt);
2861 
2862 		INIT_DELAYED_WORK(&transport->connect_worker,
2863 					xs_tcp_setup_socket);
2864 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2865 		break;
2866 	default:
2867 		ret = ERR_PTR(-EAFNOSUPPORT);
2868 		goto out_err;
2869 	}
2870 
2871 	if (xprt_bound(xprt))
2872 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2873 				xprt->address_strings[RPC_DISPLAY_ADDR],
2874 				xprt->address_strings[RPC_DISPLAY_PORT],
2875 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2876 	else
2877 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2878 				xprt->address_strings[RPC_DISPLAY_ADDR],
2879 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2880 
2881 	if (try_module_get(THIS_MODULE))
2882 		return xprt;
2883 	ret = ERR_PTR(-EINVAL);
2884 out_err:
2885 	xs_xprt_free(xprt);
2886 	return ret;
2887 }
2888 
2889 /**
2890  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2891  * @args: rpc transport creation arguments
2892  *
2893  */
2894 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2895 {
2896 	struct sockaddr *addr = args->dstaddr;
2897 	struct rpc_xprt *xprt;
2898 	struct sock_xprt *transport;
2899 	struct svc_sock *bc_sock;
2900 	struct rpc_xprt *ret;
2901 
2902 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2903 			xprt_tcp_slot_table_entries);
2904 	if (IS_ERR(xprt))
2905 		return xprt;
2906 	transport = container_of(xprt, struct sock_xprt, xprt);
2907 
2908 	xprt->prot = IPPROTO_TCP;
2909 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2910 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2911 	xprt->timeout = &xs_tcp_default_timeout;
2912 
2913 	/* backchannel */
2914 	xprt_set_bound(xprt);
2915 	xprt->bind_timeout = 0;
2916 	xprt->reestablish_timeout = 0;
2917 	xprt->idle_timeout = 0;
2918 
2919 	xprt->ops = &bc_tcp_ops;
2920 
2921 	switch (addr->sa_family) {
2922 	case AF_INET:
2923 		xs_format_peer_addresses(xprt, "tcp",
2924 					 RPCBIND_NETID_TCP);
2925 		break;
2926 	case AF_INET6:
2927 		xs_format_peer_addresses(xprt, "tcp",
2928 				   RPCBIND_NETID_TCP6);
2929 		break;
2930 	default:
2931 		ret = ERR_PTR(-EAFNOSUPPORT);
2932 		goto out_err;
2933 	}
2934 
2935 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2936 			xprt->address_strings[RPC_DISPLAY_ADDR],
2937 			xprt->address_strings[RPC_DISPLAY_PORT],
2938 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2939 
2940 	/*
2941 	 * Once we've associated a backchannel xprt with a connection,
2942 	 * we want to keep it around as long as the connection lasts,
2943 	 * in case we need to start using it for a backchannel again;
2944 	 * this reference won't be dropped until bc_xprt is destroyed.
2945 	 */
2946 	xprt_get(xprt);
2947 	args->bc_xprt->xpt_bc_xprt = xprt;
2948 	xprt->bc_xprt = args->bc_xprt;
2949 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2950 	transport->sock = bc_sock->sk_sock;
2951 	transport->inet = bc_sock->sk_sk;
2952 
2953 	/*
2954 	 * Since we don't want connections for the backchannel, we set
2955 	 * the xprt status to connected
2956 	 */
2957 	xprt_set_connected(xprt);
2958 
2959 	if (try_module_get(THIS_MODULE))
2960 		return xprt;
2961 
2962 	args->bc_xprt->xpt_bc_xprt = NULL;
2963 	xprt_put(xprt);
2964 	ret = ERR_PTR(-EINVAL);
2965 out_err:
2966 	xs_xprt_free(xprt);
2967 	return ret;
2968 }
2969 
2970 static struct xprt_class	xs_local_transport = {
2971 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2972 	.name		= "named UNIX socket",
2973 	.owner		= THIS_MODULE,
2974 	.ident		= XPRT_TRANSPORT_LOCAL,
2975 	.setup		= xs_setup_local,
2976 };
2977 
2978 static struct xprt_class	xs_udp_transport = {
2979 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2980 	.name		= "udp",
2981 	.owner		= THIS_MODULE,
2982 	.ident		= XPRT_TRANSPORT_UDP,
2983 	.setup		= xs_setup_udp,
2984 };
2985 
2986 static struct xprt_class	xs_tcp_transport = {
2987 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2988 	.name		= "tcp",
2989 	.owner		= THIS_MODULE,
2990 	.ident		= XPRT_TRANSPORT_TCP,
2991 	.setup		= xs_setup_tcp,
2992 };
2993 
2994 static struct xprt_class	xs_bc_tcp_transport = {
2995 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2996 	.name		= "tcp NFSv4.1 backchannel",
2997 	.owner		= THIS_MODULE,
2998 	.ident		= XPRT_TRANSPORT_BC_TCP,
2999 	.setup		= xs_setup_bc_tcp,
3000 };
3001 
3002 /**
3003  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3004  *
3005  */
3006 int init_socket_xprt(void)
3007 {
3008 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3009 	if (!sunrpc_table_header)
3010 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3011 #endif
3012 
3013 	xprt_register_transport(&xs_local_transport);
3014 	xprt_register_transport(&xs_udp_transport);
3015 	xprt_register_transport(&xs_tcp_transport);
3016 	xprt_register_transport(&xs_bc_tcp_transport);
3017 
3018 	return 0;
3019 }
3020 
3021 /**
3022  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3023  *
3024  */
3025 void cleanup_socket_xprt(void)
3026 {
3027 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3028 	if (sunrpc_table_header) {
3029 		unregister_sysctl_table(sunrpc_table_header);
3030 		sunrpc_table_header = NULL;
3031 	}
3032 #endif
3033 
3034 	xprt_unregister_transport(&xs_local_transport);
3035 	xprt_unregister_transport(&xs_udp_transport);
3036 	xprt_unregister_transport(&xs_tcp_transport);
3037 	xprt_unregister_transport(&xs_bc_tcp_transport);
3038 }
3039 
3040 static int param_set_uint_minmax(const char *val,
3041 		const struct kernel_param *kp,
3042 		unsigned int min, unsigned int max)
3043 {
3044 	unsigned int num;
3045 	int ret;
3046 
3047 	if (!val)
3048 		return -EINVAL;
3049 	ret = kstrtouint(val, 0, &num);
3050 	if (ret == -EINVAL || num < min || num > max)
3051 		return -EINVAL;
3052 	*((unsigned int *)kp->arg) = num;
3053 	return 0;
3054 }
3055 
3056 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3057 {
3058 	return param_set_uint_minmax(val, kp,
3059 			RPC_MIN_RESVPORT,
3060 			RPC_MAX_RESVPORT);
3061 }
3062 
3063 static const struct kernel_param_ops param_ops_portnr = {
3064 	.set = param_set_portnr,
3065 	.get = param_get_uint,
3066 };
3067 
3068 #define param_check_portnr(name, p) \
3069 	__param_check(name, p, unsigned int);
3070 
3071 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3072 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3073 
3074 static int param_set_slot_table_size(const char *val,
3075 				     const struct kernel_param *kp)
3076 {
3077 	return param_set_uint_minmax(val, kp,
3078 			RPC_MIN_SLOT_TABLE,
3079 			RPC_MAX_SLOT_TABLE);
3080 }
3081 
3082 static const struct kernel_param_ops param_ops_slot_table_size = {
3083 	.set = param_set_slot_table_size,
3084 	.get = param_get_uint,
3085 };
3086 
3087 #define param_check_slot_table_size(name, p) \
3088 	__param_check(name, p, unsigned int);
3089 
3090 static int param_set_max_slot_table_size(const char *val,
3091 				     const struct kernel_param *kp)
3092 {
3093 	return param_set_uint_minmax(val, kp,
3094 			RPC_MIN_SLOT_TABLE,
3095 			RPC_MAX_SLOT_TABLE_LIMIT);
3096 }
3097 
3098 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3099 	.set = param_set_max_slot_table_size,
3100 	.get = param_get_uint,
3101 };
3102 
3103 #define param_check_max_slot_table_size(name, p) \
3104 	__param_check(name, p, unsigned int);
3105 
3106 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3107 		   slot_table_size, 0644);
3108 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3109 		   max_slot_table_size, 0644);
3110 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3111 		   slot_table_size, 0644);
3112 
3113