xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 3913c78c)
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 #define XS_TCP_LINGER_TO	(15U * HZ)
67 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
68 
69 /*
70  * We can register our own files under /proc/sys/sunrpc by
71  * calling register_sysctl_table() again.  The files in that
72  * directory become the union of all files registered there.
73  *
74  * We simply need to make sure that we don't collide with
75  * someone else's file names!
76  */
77 
78 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
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 	if (likely(sent > 0) || status == 0) {
531 		req->rq_bytes_sent += sent;
532 		req->rq_xmit_bytes_sent += sent;
533 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
534 			req->rq_bytes_sent = 0;
535 			return 0;
536 		}
537 		status = -EAGAIN;
538 	}
539 
540 	switch (status) {
541 	case -ENOBUFS:
542 	case -EAGAIN:
543 		status = xs_nospace(task);
544 		break;
545 	default:
546 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
547 			-status);
548 	case -EPIPE:
549 		xs_close(xprt);
550 		status = -ENOTCONN;
551 	}
552 
553 	return status;
554 }
555 
556 /**
557  * xs_udp_send_request - write an RPC request to a UDP socket
558  * @task: address of RPC task that manages the state of an RPC request
559  *
560  * Return values:
561  *        0:	The request has been sent
562  *   EAGAIN:	The socket was blocked, please call again later to
563  *		complete the request
564  * ENOTCONN:	Caller needs to invoke connect logic then call again
565  *    other:	Some other error occurred, the request was not sent
566  */
567 static int xs_udp_send_request(struct rpc_task *task)
568 {
569 	struct rpc_rqst *req = task->tk_rqstp;
570 	struct rpc_xprt *xprt = req->rq_xprt;
571 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
572 	struct xdr_buf *xdr = &req->rq_snd_buf;
573 	int sent = 0;
574 	int status;
575 
576 	xs_pktdump("packet data:",
577 				req->rq_svec->iov_base,
578 				req->rq_svec->iov_len);
579 
580 	if (!xprt_bound(xprt))
581 		return -ENOTCONN;
582 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
583 			      xdr, req->rq_bytes_sent, true, &sent);
584 
585 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
586 			xdr->len - req->rq_bytes_sent, status);
587 
588 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
589 	if (status == -EPERM)
590 		goto process_status;
591 
592 	if (sent > 0 || status == 0) {
593 		req->rq_xmit_bytes_sent += sent;
594 		if (sent >= req->rq_slen)
595 			return 0;
596 		/* Still some bytes left; set up for a retry later. */
597 		status = -EAGAIN;
598 	}
599 
600 process_status:
601 	switch (status) {
602 	case -ENOTSOCK:
603 		status = -ENOTCONN;
604 		/* Should we call xs_close() here? */
605 		break;
606 	case -EAGAIN:
607 		status = xs_nospace(task);
608 		break;
609 	default:
610 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
611 			-status);
612 	case -ENETUNREACH:
613 	case -ENOBUFS:
614 	case -EPIPE:
615 	case -ECONNREFUSED:
616 	case -EPERM:
617 		/* When the server has died, an ICMP port unreachable message
618 		 * prompts ECONNREFUSED. */
619 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
620 	}
621 
622 	return status;
623 }
624 
625 /**
626  * xs_tcp_shutdown - gracefully shut down a TCP socket
627  * @xprt: transport
628  *
629  * Initiates a graceful shutdown of the TCP socket by calling the
630  * equivalent of shutdown(SHUT_WR);
631  */
632 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
633 {
634 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
635 	struct socket *sock = transport->sock;
636 
637 	if (sock != NULL) {
638 		kernel_sock_shutdown(sock, SHUT_WR);
639 		trace_rpc_socket_shutdown(xprt, sock);
640 	}
641 }
642 
643 /**
644  * xs_tcp_send_request - write an RPC request to a TCP socket
645  * @task: address of RPC task that manages the state of an RPC request
646  *
647  * Return values:
648  *        0:	The request has been sent
649  *   EAGAIN:	The socket was blocked, please call again later to
650  *		complete the request
651  * ENOTCONN:	Caller needs to invoke connect logic then call again
652  *    other:	Some other error occurred, the request was not sent
653  *
654  * XXX: In the case of soft timeouts, should we eventually give up
655  *	if sendmsg is not able to make progress?
656  */
657 static int xs_tcp_send_request(struct rpc_task *task)
658 {
659 	struct rpc_rqst *req = task->tk_rqstp;
660 	struct rpc_xprt *xprt = req->rq_xprt;
661 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
662 	struct xdr_buf *xdr = &req->rq_snd_buf;
663 	bool zerocopy = true;
664 	int status;
665 	int sent;
666 
667 	xs_encode_stream_record_marker(&req->rq_snd_buf);
668 
669 	xs_pktdump("packet data:",
670 				req->rq_svec->iov_base,
671 				req->rq_svec->iov_len);
672 	/* Don't use zero copy if this is a resend. If the RPC call
673 	 * completes while the socket holds a reference to the pages,
674 	 * then we may end up resending corrupted data.
675 	 */
676 	if (task->tk_flags & RPC_TASK_SENT)
677 		zerocopy = false;
678 
679 	/* Continue transmitting the packet/record. We must be careful
680 	 * to cope with writespace callbacks arriving _after_ we have
681 	 * called sendmsg(). */
682 	while (1) {
683 		sent = 0;
684 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
685 				      req->rq_bytes_sent, zerocopy, &sent);
686 
687 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
688 				xdr->len - req->rq_bytes_sent, status);
689 
690 		if (unlikely(sent == 0 && status < 0))
691 			break;
692 
693 		/* If we've sent the entire packet, immediately
694 		 * reset the count of bytes sent. */
695 		req->rq_bytes_sent += sent;
696 		req->rq_xmit_bytes_sent += sent;
697 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
698 			req->rq_bytes_sent = 0;
699 			return 0;
700 		}
701 
702 		if (sent != 0)
703 			continue;
704 		status = -EAGAIN;
705 		break;
706 	}
707 
708 	switch (status) {
709 	case -ENOTSOCK:
710 		status = -ENOTCONN;
711 		/* Should we call xs_close() here? */
712 		break;
713 	case -ENOBUFS:
714 	case -EAGAIN:
715 		status = xs_nospace(task);
716 		break;
717 	default:
718 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
719 			-status);
720 	case -ECONNRESET:
721 		xs_tcp_shutdown(xprt);
722 	case -ECONNREFUSED:
723 	case -ENOTCONN:
724 	case -EADDRINUSE:
725 	case -EPIPE:
726 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
727 	}
728 
729 	return status;
730 }
731 
732 /**
733  * xs_tcp_release_xprt - clean up after a tcp transmission
734  * @xprt: transport
735  * @task: rpc task
736  *
737  * This cleans up if an error causes us to abort the transmission of a request.
738  * In this case, the socket may need to be reset in order to avoid confusing
739  * the server.
740  */
741 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
742 {
743 	struct rpc_rqst *req;
744 
745 	if (task != xprt->snd_task)
746 		return;
747 	if (task == NULL)
748 		goto out_release;
749 	req = task->tk_rqstp;
750 	if (req == NULL)
751 		goto out_release;
752 	if (req->rq_bytes_sent == 0)
753 		goto out_release;
754 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
755 		goto out_release;
756 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
757 out_release:
758 	xprt_release_xprt(xprt, task);
759 }
760 
761 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
762 {
763 	transport->old_data_ready = sk->sk_data_ready;
764 	transport->old_state_change = sk->sk_state_change;
765 	transport->old_write_space = sk->sk_write_space;
766 	transport->old_error_report = sk->sk_error_report;
767 }
768 
769 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
770 {
771 	sk->sk_data_ready = transport->old_data_ready;
772 	sk->sk_state_change = transport->old_state_change;
773 	sk->sk_write_space = transport->old_write_space;
774 	sk->sk_error_report = transport->old_error_report;
775 }
776 
777 /**
778  * xs_error_report - callback to handle TCP socket state errors
779  * @sk: socket
780  *
781  * Note: we don't call sock_error() since there may be a rpc_task
782  * using the socket, and so we don't want to clear sk->sk_err.
783  */
784 static void xs_error_report(struct sock *sk)
785 {
786 	struct rpc_xprt *xprt;
787 	int err;
788 
789 	read_lock_bh(&sk->sk_callback_lock);
790 	if (!(xprt = xprt_from_sock(sk)))
791 		goto out;
792 
793 	err = -sk->sk_err;
794 	if (err == 0)
795 		goto out;
796 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
797 			xprt, -err);
798 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
799 	if (test_bit(XPRT_CONNECTION_REUSE, &xprt->state))
800 		goto out;
801 	xprt_wake_pending_tasks(xprt, err);
802  out:
803 	read_unlock_bh(&sk->sk_callback_lock);
804 }
805 
806 static void xs_reset_transport(struct sock_xprt *transport)
807 {
808 	struct socket *sock = transport->sock;
809 	struct sock *sk = transport->inet;
810 
811 	if (sk == NULL)
812 		return;
813 
814 	transport->srcport = 0;
815 
816 	write_lock_bh(&sk->sk_callback_lock);
817 	transport->inet = NULL;
818 	transport->sock = NULL;
819 
820 	sk->sk_user_data = NULL;
821 
822 	xs_restore_old_callbacks(transport, sk);
823 	write_unlock_bh(&sk->sk_callback_lock);
824 
825 	trace_rpc_socket_close(&transport->xprt, sock);
826 	sock_release(sock);
827 }
828 
829 /**
830  * xs_close - close a socket
831  * @xprt: transport
832  *
833  * This is used when all requests are complete; ie, no DRC state remains
834  * on the server we want to save.
835  *
836  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
837  * xs_reset_transport() zeroing the socket from underneath a writer.
838  */
839 static void xs_close(struct rpc_xprt *xprt)
840 {
841 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
842 
843 	dprintk("RPC:       xs_close xprt %p\n", xprt);
844 
845 	cancel_delayed_work_sync(&transport->connect_worker);
846 
847 	xs_reset_transport(transport);
848 	xprt->reestablish_timeout = 0;
849 
850 	smp_mb__before_atomic();
851 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
852 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
853 	clear_bit(XPRT_CLOSING, &xprt->state);
854 	smp_mb__after_atomic();
855 	xprt_disconnect_done(xprt);
856 }
857 
858 static void xs_tcp_close(struct rpc_xprt *xprt)
859 {
860 	if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
861 		xs_close(xprt);
862 	else
863 		xs_tcp_shutdown(xprt);
864 }
865 
866 static void xs_xprt_free(struct rpc_xprt *xprt)
867 {
868 	xs_free_peer_addresses(xprt);
869 	xprt_free(xprt);
870 }
871 
872 /**
873  * xs_destroy - prepare to shutdown a transport
874  * @xprt: doomed transport
875  *
876  */
877 static void xs_destroy(struct rpc_xprt *xprt)
878 {
879 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
880 
881 	xs_close(xprt);
882 	xs_xprt_free(xprt);
883 	module_put(THIS_MODULE);
884 }
885 
886 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
887 {
888 	struct xdr_skb_reader desc = {
889 		.skb		= skb,
890 		.offset		= sizeof(rpc_fraghdr),
891 		.count		= skb->len - sizeof(rpc_fraghdr),
892 	};
893 
894 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
895 		return -1;
896 	if (desc.count)
897 		return -1;
898 	return 0;
899 }
900 
901 /**
902  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
903  * @sk: socket with data to read
904  * @len: how much data to read
905  *
906  * Currently this assumes we can read the whole reply in a single gulp.
907  */
908 static void xs_local_data_ready(struct sock *sk)
909 {
910 	struct rpc_task *task;
911 	struct rpc_xprt *xprt;
912 	struct rpc_rqst *rovr;
913 	struct sk_buff *skb;
914 	int err, repsize, copied;
915 	u32 _xid;
916 	__be32 *xp;
917 
918 	read_lock_bh(&sk->sk_callback_lock);
919 	dprintk("RPC:       %s...\n", __func__);
920 	xprt = xprt_from_sock(sk);
921 	if (xprt == NULL)
922 		goto out;
923 
924 	skb = skb_recv_datagram(sk, 0, 1, &err);
925 	if (skb == NULL)
926 		goto out;
927 
928 	repsize = skb->len - sizeof(rpc_fraghdr);
929 	if (repsize < 4) {
930 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
931 		goto dropit;
932 	}
933 
934 	/* Copy the XID from the skb... */
935 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
936 	if (xp == NULL)
937 		goto dropit;
938 
939 	/* Look up and lock the request corresponding to the given XID */
940 	spin_lock(&xprt->transport_lock);
941 	rovr = xprt_lookup_rqst(xprt, *xp);
942 	if (!rovr)
943 		goto out_unlock;
944 	task = rovr->rq_task;
945 
946 	copied = rovr->rq_private_buf.buflen;
947 	if (copied > repsize)
948 		copied = repsize;
949 
950 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
951 		dprintk("RPC:       sk_buff copy failed\n");
952 		goto out_unlock;
953 	}
954 
955 	xprt_complete_rqst(task, copied);
956 
957  out_unlock:
958 	spin_unlock(&xprt->transport_lock);
959  dropit:
960 	skb_free_datagram(sk, skb);
961  out:
962 	read_unlock_bh(&sk->sk_callback_lock);
963 }
964 
965 /**
966  * xs_udp_data_ready - "data ready" callback for UDP sockets
967  * @sk: socket with data to read
968  * @len: how much data to read
969  *
970  */
971 static void xs_udp_data_ready(struct sock *sk)
972 {
973 	struct rpc_task *task;
974 	struct rpc_xprt *xprt;
975 	struct rpc_rqst *rovr;
976 	struct sk_buff *skb;
977 	int err, repsize, copied;
978 	u32 _xid;
979 	__be32 *xp;
980 
981 	read_lock_bh(&sk->sk_callback_lock);
982 	dprintk("RPC:       xs_udp_data_ready...\n");
983 	if (!(xprt = xprt_from_sock(sk)))
984 		goto out;
985 
986 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
987 		goto out;
988 
989 	repsize = skb->len - sizeof(struct udphdr);
990 	if (repsize < 4) {
991 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
992 		goto dropit;
993 	}
994 
995 	/* Copy the XID from the skb... */
996 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
997 				sizeof(_xid), &_xid);
998 	if (xp == NULL)
999 		goto dropit;
1000 
1001 	/* Look up and lock the request corresponding to the given XID */
1002 	spin_lock(&xprt->transport_lock);
1003 	rovr = xprt_lookup_rqst(xprt, *xp);
1004 	if (!rovr)
1005 		goto out_unlock;
1006 	task = rovr->rq_task;
1007 
1008 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1009 		copied = repsize;
1010 
1011 	/* Suck it into the iovec, verify checksum if not done by hw. */
1012 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1013 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1014 		goto out_unlock;
1015 	}
1016 
1017 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1018 
1019 	xprt_adjust_cwnd(xprt, task, copied);
1020 	xprt_complete_rqst(task, copied);
1021 
1022  out_unlock:
1023 	spin_unlock(&xprt->transport_lock);
1024  dropit:
1025 	skb_free_datagram(sk, skb);
1026  out:
1027 	read_unlock_bh(&sk->sk_callback_lock);
1028 }
1029 
1030 /*
1031  * Helper function to force a TCP close if the server is sending
1032  * junk and/or it has put us in CLOSE_WAIT
1033  */
1034 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1035 {
1036 	set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1037 	xprt_force_disconnect(xprt);
1038 }
1039 
1040 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1041 {
1042 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1043 	size_t len, used;
1044 	char *p;
1045 
1046 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1047 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1048 	used = xdr_skb_read_bits(desc, p, len);
1049 	transport->tcp_offset += used;
1050 	if (used != len)
1051 		return;
1052 
1053 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1054 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1055 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1056 	else
1057 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1058 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1059 
1060 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1061 	transport->tcp_offset = 0;
1062 
1063 	/* Sanity check of the record length */
1064 	if (unlikely(transport->tcp_reclen < 8)) {
1065 		dprintk("RPC:       invalid TCP record fragment length\n");
1066 		xs_tcp_force_close(xprt);
1067 		return;
1068 	}
1069 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1070 			transport->tcp_reclen);
1071 }
1072 
1073 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1074 {
1075 	if (transport->tcp_offset == transport->tcp_reclen) {
1076 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1077 		transport->tcp_offset = 0;
1078 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1079 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1080 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1081 			transport->tcp_copied = 0;
1082 		}
1083 	}
1084 }
1085 
1086 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1087 {
1088 	size_t len, used;
1089 	char *p;
1090 
1091 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1092 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1093 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1094 	used = xdr_skb_read_bits(desc, p, len);
1095 	transport->tcp_offset += used;
1096 	if (used != len)
1097 		return;
1098 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1099 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1100 	transport->tcp_copied = 4;
1101 	dprintk("RPC:       reading %s XID %08x\n",
1102 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1103 							      : "request with",
1104 			ntohl(transport->tcp_xid));
1105 	xs_tcp_check_fraghdr(transport);
1106 }
1107 
1108 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1109 				       struct xdr_skb_reader *desc)
1110 {
1111 	size_t len, used;
1112 	u32 offset;
1113 	char *p;
1114 
1115 	/*
1116 	 * We want transport->tcp_offset to be 8 at the end of this routine
1117 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1118 	 * When this function is called for the first time,
1119 	 * transport->tcp_offset is 4 (after having already read the xid).
1120 	 */
1121 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1122 	len = sizeof(transport->tcp_calldir) - offset;
1123 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1124 	p = ((char *) &transport->tcp_calldir) + offset;
1125 	used = xdr_skb_read_bits(desc, p, len);
1126 	transport->tcp_offset += used;
1127 	if (used != len)
1128 		return;
1129 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1130 	/*
1131 	 * We don't yet have the XDR buffer, so we will write the calldir
1132 	 * out after we get the buffer from the 'struct rpc_rqst'
1133 	 */
1134 	switch (ntohl(transport->tcp_calldir)) {
1135 	case RPC_REPLY:
1136 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1137 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1138 		transport->tcp_flags |= TCP_RPC_REPLY;
1139 		break;
1140 	case RPC_CALL:
1141 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1142 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1143 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1144 		break;
1145 	default:
1146 		dprintk("RPC:       invalid request message type\n");
1147 		xs_tcp_force_close(&transport->xprt);
1148 	}
1149 	xs_tcp_check_fraghdr(transport);
1150 }
1151 
1152 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1153 				     struct xdr_skb_reader *desc,
1154 				     struct rpc_rqst *req)
1155 {
1156 	struct sock_xprt *transport =
1157 				container_of(xprt, struct sock_xprt, xprt);
1158 	struct xdr_buf *rcvbuf;
1159 	size_t len;
1160 	ssize_t r;
1161 
1162 	rcvbuf = &req->rq_private_buf;
1163 
1164 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1165 		/*
1166 		 * Save the RPC direction in the XDR buffer
1167 		 */
1168 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1169 			&transport->tcp_calldir,
1170 			sizeof(transport->tcp_calldir));
1171 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1172 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1173 	}
1174 
1175 	len = desc->count;
1176 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1177 		struct xdr_skb_reader my_desc;
1178 
1179 		len = transport->tcp_reclen - transport->tcp_offset;
1180 		memcpy(&my_desc, desc, sizeof(my_desc));
1181 		my_desc.count = len;
1182 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1183 					  &my_desc, xdr_skb_read_bits);
1184 		desc->count -= r;
1185 		desc->offset += r;
1186 	} else
1187 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1188 					  desc, xdr_skb_read_bits);
1189 
1190 	if (r > 0) {
1191 		transport->tcp_copied += r;
1192 		transport->tcp_offset += r;
1193 	}
1194 	if (r != len) {
1195 		/* Error when copying to the receive buffer,
1196 		 * usually because we weren't able to allocate
1197 		 * additional buffer pages. All we can do now
1198 		 * is turn off TCP_RCV_COPY_DATA, so the request
1199 		 * will not receive any additional updates,
1200 		 * and time out.
1201 		 * Any remaining data from this record will
1202 		 * be discarded.
1203 		 */
1204 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1205 		dprintk("RPC:       XID %08x truncated request\n",
1206 				ntohl(transport->tcp_xid));
1207 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1208 				"tcp_offset = %u, tcp_reclen = %u\n",
1209 				xprt, transport->tcp_copied,
1210 				transport->tcp_offset, transport->tcp_reclen);
1211 		return;
1212 	}
1213 
1214 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1215 			ntohl(transport->tcp_xid), r);
1216 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1217 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1218 			transport->tcp_offset, transport->tcp_reclen);
1219 
1220 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1221 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1222 	else if (transport->tcp_offset == transport->tcp_reclen) {
1223 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1224 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1225 	}
1226 }
1227 
1228 /*
1229  * Finds the request corresponding to the RPC xid and invokes the common
1230  * tcp read code to read the data.
1231  */
1232 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1233 				    struct xdr_skb_reader *desc)
1234 {
1235 	struct sock_xprt *transport =
1236 				container_of(xprt, struct sock_xprt, xprt);
1237 	struct rpc_rqst *req;
1238 
1239 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1240 
1241 	/* Find and lock the request corresponding to this xid */
1242 	spin_lock(&xprt->transport_lock);
1243 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1244 	if (!req) {
1245 		dprintk("RPC:       XID %08x request not found!\n",
1246 				ntohl(transport->tcp_xid));
1247 		spin_unlock(&xprt->transport_lock);
1248 		return -1;
1249 	}
1250 
1251 	xs_tcp_read_common(xprt, desc, req);
1252 
1253 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1254 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1255 
1256 	spin_unlock(&xprt->transport_lock);
1257 	return 0;
1258 }
1259 
1260 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1261 /*
1262  * Obtains an rpc_rqst previously allocated and invokes the common
1263  * tcp read code to read the data.  The result is placed in the callback
1264  * queue.
1265  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1266  * connection and return -1.
1267  */
1268 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1269 				       struct xdr_skb_reader *desc)
1270 {
1271 	struct sock_xprt *transport =
1272 				container_of(xprt, struct sock_xprt, xprt);
1273 	struct rpc_rqst *req;
1274 
1275 	/* Look up and lock the request corresponding to the given XID */
1276 	spin_lock(&xprt->transport_lock);
1277 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1278 	if (req == NULL) {
1279 		spin_unlock(&xprt->transport_lock);
1280 		printk(KERN_WARNING "Callback slot table overflowed\n");
1281 		xprt_force_disconnect(xprt);
1282 		return -1;
1283 	}
1284 
1285 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1286 	xs_tcp_read_common(xprt, desc, req);
1287 
1288 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1289 		xprt_complete_bc_request(req, transport->tcp_copied);
1290 	spin_unlock(&xprt->transport_lock);
1291 
1292 	return 0;
1293 }
1294 
1295 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1296 					struct xdr_skb_reader *desc)
1297 {
1298 	struct sock_xprt *transport =
1299 				container_of(xprt, struct sock_xprt, xprt);
1300 
1301 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1302 		xs_tcp_read_reply(xprt, desc) :
1303 		xs_tcp_read_callback(xprt, desc);
1304 }
1305 #else
1306 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1307 					struct xdr_skb_reader *desc)
1308 {
1309 	return xs_tcp_read_reply(xprt, desc);
1310 }
1311 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1312 
1313 /*
1314  * Read data off the transport.  This can be either an RPC_CALL or an
1315  * RPC_REPLY.  Relay the processing to helper functions.
1316  */
1317 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1318 				    struct xdr_skb_reader *desc)
1319 {
1320 	struct sock_xprt *transport =
1321 				container_of(xprt, struct sock_xprt, xprt);
1322 
1323 	if (_xs_tcp_read_data(xprt, desc) == 0)
1324 		xs_tcp_check_fraghdr(transport);
1325 	else {
1326 		/*
1327 		 * The transport_lock protects the request handling.
1328 		 * There's no need to hold it to update the tcp_flags.
1329 		 */
1330 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1331 	}
1332 }
1333 
1334 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1335 {
1336 	size_t len;
1337 
1338 	len = transport->tcp_reclen - transport->tcp_offset;
1339 	if (len > desc->count)
1340 		len = desc->count;
1341 	desc->count -= len;
1342 	desc->offset += len;
1343 	transport->tcp_offset += len;
1344 	dprintk("RPC:       discarded %Zu bytes\n", len);
1345 	xs_tcp_check_fraghdr(transport);
1346 }
1347 
1348 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1349 {
1350 	struct rpc_xprt *xprt = rd_desc->arg.data;
1351 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1352 	struct xdr_skb_reader desc = {
1353 		.skb	= skb,
1354 		.offset	= offset,
1355 		.count	= len,
1356 	};
1357 
1358 	dprintk("RPC:       xs_tcp_data_recv started\n");
1359 	do {
1360 		trace_xs_tcp_data_recv(transport);
1361 		/* Read in a new fragment marker if necessary */
1362 		/* Can we ever really expect to get completely empty fragments? */
1363 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1364 			xs_tcp_read_fraghdr(xprt, &desc);
1365 			continue;
1366 		}
1367 		/* Read in the xid if necessary */
1368 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1369 			xs_tcp_read_xid(transport, &desc);
1370 			continue;
1371 		}
1372 		/* Read in the call/reply flag */
1373 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1374 			xs_tcp_read_calldir(transport, &desc);
1375 			continue;
1376 		}
1377 		/* Read in the request data */
1378 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1379 			xs_tcp_read_data(xprt, &desc);
1380 			continue;
1381 		}
1382 		/* Skip over any trailing bytes on short reads */
1383 		xs_tcp_read_discard(transport, &desc);
1384 	} while (desc.count);
1385 	trace_xs_tcp_data_recv(transport);
1386 	dprintk("RPC:       xs_tcp_data_recv done\n");
1387 	return len - desc.count;
1388 }
1389 
1390 /**
1391  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1392  * @sk: socket with data to read
1393  * @bytes: how much data to read
1394  *
1395  */
1396 static void xs_tcp_data_ready(struct sock *sk)
1397 {
1398 	struct rpc_xprt *xprt;
1399 	read_descriptor_t rd_desc;
1400 	int read;
1401 	unsigned long total = 0;
1402 
1403 	dprintk("RPC:       xs_tcp_data_ready...\n");
1404 
1405 	read_lock_bh(&sk->sk_callback_lock);
1406 	if (!(xprt = xprt_from_sock(sk))) {
1407 		read = 0;
1408 		goto out;
1409 	}
1410 	/* Any data means we had a useful conversation, so
1411 	 * the we don't need to delay the next reconnect
1412 	 */
1413 	if (xprt->reestablish_timeout)
1414 		xprt->reestablish_timeout = 0;
1415 
1416 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1417 	rd_desc.arg.data = xprt;
1418 	do {
1419 		rd_desc.count = 65536;
1420 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1421 		if (read > 0)
1422 			total += read;
1423 	} while (read > 0);
1424 out:
1425 	trace_xs_tcp_data_ready(xprt, read, total);
1426 	read_unlock_bh(&sk->sk_callback_lock);
1427 }
1428 
1429 /*
1430  * Do the equivalent of linger/linger2 handling for dealing with
1431  * broken servers that don't close the socket in a timely
1432  * fashion
1433  */
1434 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1435 		unsigned long timeout)
1436 {
1437 	struct sock_xprt *transport;
1438 
1439 	if (xprt_test_and_set_connecting(xprt))
1440 		return;
1441 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1442 	transport = container_of(xprt, struct sock_xprt, xprt);
1443 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1444 			   timeout);
1445 }
1446 
1447 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1448 {
1449 	struct sock_xprt *transport;
1450 
1451 	transport = container_of(xprt, struct sock_xprt, xprt);
1452 
1453 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1454 	    !cancel_delayed_work(&transport->connect_worker))
1455 		return;
1456 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1457 	xprt_clear_connecting(xprt);
1458 }
1459 
1460 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1461 {
1462 	smp_mb__before_atomic();
1463 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1464 	clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1465 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1466 	clear_bit(XPRT_CLOSING, &xprt->state);
1467 	smp_mb__after_atomic();
1468 }
1469 
1470 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1471 {
1472 	xs_sock_reset_connection_flags(xprt);
1473 	/* Mark transport as closed and wake up all pending tasks */
1474 	xprt_disconnect_done(xprt);
1475 }
1476 
1477 /**
1478  * xs_tcp_state_change - callback to handle TCP socket state changes
1479  * @sk: socket whose state has changed
1480  *
1481  */
1482 static void xs_tcp_state_change(struct sock *sk)
1483 {
1484 	struct rpc_xprt *xprt;
1485 
1486 	read_lock_bh(&sk->sk_callback_lock);
1487 	if (!(xprt = xprt_from_sock(sk)))
1488 		goto out;
1489 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1490 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1491 			sk->sk_state, xprt_connected(xprt),
1492 			sock_flag(sk, SOCK_DEAD),
1493 			sock_flag(sk, SOCK_ZAPPED),
1494 			sk->sk_shutdown);
1495 
1496 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1497 	switch (sk->sk_state) {
1498 	case TCP_ESTABLISHED:
1499 		spin_lock(&xprt->transport_lock);
1500 		if (!xprt_test_and_set_connected(xprt)) {
1501 			struct sock_xprt *transport = container_of(xprt,
1502 					struct sock_xprt, xprt);
1503 
1504 			/* Reset TCP record info */
1505 			transport->tcp_offset = 0;
1506 			transport->tcp_reclen = 0;
1507 			transport->tcp_copied = 0;
1508 			transport->tcp_flags =
1509 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1510 			xprt->connect_cookie++;
1511 
1512 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1513 		}
1514 		spin_unlock(&xprt->transport_lock);
1515 		break;
1516 	case TCP_FIN_WAIT1:
1517 		/* The client initiated a shutdown of the socket */
1518 		xprt->connect_cookie++;
1519 		xprt->reestablish_timeout = 0;
1520 		set_bit(XPRT_CLOSING, &xprt->state);
1521 		smp_mb__before_atomic();
1522 		clear_bit(XPRT_CONNECTED, &xprt->state);
1523 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1524 		smp_mb__after_atomic();
1525 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1526 		break;
1527 	case TCP_CLOSE_WAIT:
1528 		/* The server initiated a shutdown of the socket */
1529 		xprt->connect_cookie++;
1530 		clear_bit(XPRT_CONNECTED, &xprt->state);
1531 		xs_tcp_force_close(xprt);
1532 	case TCP_CLOSING:
1533 		/*
1534 		 * If the server closed down the connection, make sure that
1535 		 * we back off before reconnecting
1536 		 */
1537 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1538 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1539 		break;
1540 	case TCP_LAST_ACK:
1541 		set_bit(XPRT_CLOSING, &xprt->state);
1542 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1543 		smp_mb__before_atomic();
1544 		clear_bit(XPRT_CONNECTED, &xprt->state);
1545 		smp_mb__after_atomic();
1546 		break;
1547 	case TCP_CLOSE:
1548 		xs_tcp_cancel_linger_timeout(xprt);
1549 		xs_sock_mark_closed(xprt);
1550 	}
1551  out:
1552 	read_unlock_bh(&sk->sk_callback_lock);
1553 }
1554 
1555 static void xs_write_space(struct sock *sk)
1556 {
1557 	struct socket *sock;
1558 	struct rpc_xprt *xprt;
1559 
1560 	if (unlikely(!(sock = sk->sk_socket)))
1561 		return;
1562 	clear_bit(SOCK_NOSPACE, &sock->flags);
1563 
1564 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1565 		return;
1566 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1567 		return;
1568 
1569 	xprt_write_space(xprt);
1570 }
1571 
1572 /**
1573  * xs_udp_write_space - callback invoked when socket buffer space
1574  *                             becomes available
1575  * @sk: socket whose state has changed
1576  *
1577  * Called when more output buffer space is available for this socket.
1578  * We try not to wake our writers until they can make "significant"
1579  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1580  * with a bunch of small requests.
1581  */
1582 static void xs_udp_write_space(struct sock *sk)
1583 {
1584 	read_lock_bh(&sk->sk_callback_lock);
1585 
1586 	/* from net/core/sock.c:sock_def_write_space */
1587 	if (sock_writeable(sk))
1588 		xs_write_space(sk);
1589 
1590 	read_unlock_bh(&sk->sk_callback_lock);
1591 }
1592 
1593 /**
1594  * xs_tcp_write_space - callback invoked when socket buffer space
1595  *                             becomes available
1596  * @sk: socket whose state has changed
1597  *
1598  * Called when more output buffer space is available for this socket.
1599  * We try not to wake our writers until they can make "significant"
1600  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1601  * with a bunch of small requests.
1602  */
1603 static void xs_tcp_write_space(struct sock *sk)
1604 {
1605 	read_lock_bh(&sk->sk_callback_lock);
1606 
1607 	/* from net/core/stream.c:sk_stream_write_space */
1608 	if (sk_stream_is_writeable(sk))
1609 		xs_write_space(sk);
1610 
1611 	read_unlock_bh(&sk->sk_callback_lock);
1612 }
1613 
1614 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1615 {
1616 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1617 	struct sock *sk = transport->inet;
1618 
1619 	if (transport->rcvsize) {
1620 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1621 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1622 	}
1623 	if (transport->sndsize) {
1624 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1625 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1626 		sk->sk_write_space(sk);
1627 	}
1628 }
1629 
1630 /**
1631  * xs_udp_set_buffer_size - set send and receive limits
1632  * @xprt: generic transport
1633  * @sndsize: requested size of send buffer, in bytes
1634  * @rcvsize: requested size of receive buffer, in bytes
1635  *
1636  * Set socket send and receive buffer size limits.
1637  */
1638 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1639 {
1640 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1641 
1642 	transport->sndsize = 0;
1643 	if (sndsize)
1644 		transport->sndsize = sndsize + 1024;
1645 	transport->rcvsize = 0;
1646 	if (rcvsize)
1647 		transport->rcvsize = rcvsize + 1024;
1648 
1649 	xs_udp_do_set_buffer_size(xprt);
1650 }
1651 
1652 /**
1653  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1654  * @task: task that timed out
1655  *
1656  * Adjust the congestion window after a retransmit timeout has occurred.
1657  */
1658 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1659 {
1660 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1661 }
1662 
1663 static unsigned short xs_get_random_port(void)
1664 {
1665 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1666 	unsigned short rand = (unsigned short) prandom_u32() % range;
1667 	return rand + xprt_min_resvport;
1668 }
1669 
1670 /**
1671  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1672  * @sock: socket
1673  *
1674  * Note that this function has to be called on all sockets that share the
1675  * same port, and it must be called before binding.
1676  */
1677 static void xs_sock_set_reuseport(struct socket *sock)
1678 {
1679 	char opt = 1;
1680 
1681 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt));
1682 }
1683 
1684 static unsigned short xs_sock_getport(struct socket *sock)
1685 {
1686 	struct sockaddr_storage buf;
1687 	int buflen;
1688 	unsigned short port = 0;
1689 
1690 	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1691 		goto out;
1692 	switch (buf.ss_family) {
1693 	case AF_INET6:
1694 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1695 		break;
1696 	case AF_INET:
1697 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1698 	}
1699 out:
1700 	return port;
1701 }
1702 
1703 /**
1704  * xs_set_port - reset the port number in the remote endpoint address
1705  * @xprt: generic transport
1706  * @port: new port number
1707  *
1708  */
1709 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1710 {
1711 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1712 
1713 	rpc_set_port(xs_addr(xprt), port);
1714 	xs_update_peer_port(xprt);
1715 }
1716 
1717 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1718 {
1719 	if (transport->srcport == 0)
1720 		transport->srcport = xs_sock_getport(sock);
1721 }
1722 
1723 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1724 {
1725 	unsigned short port = transport->srcport;
1726 
1727 	if (port == 0 && transport->xprt.resvport)
1728 		port = xs_get_random_port();
1729 	return port;
1730 }
1731 
1732 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1733 {
1734 	if (transport->srcport != 0)
1735 		transport->srcport = 0;
1736 	if (!transport->xprt.resvport)
1737 		return 0;
1738 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1739 		return xprt_max_resvport;
1740 	return --port;
1741 }
1742 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1743 {
1744 	struct sockaddr_storage myaddr;
1745 	int err, nloop = 0;
1746 	unsigned short port = xs_get_srcport(transport);
1747 	unsigned short last;
1748 
1749 	/*
1750 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1751 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1752 	 * port selection happen implicitly when the socket is used
1753 	 * (for example at connect time).
1754 	 *
1755 	 * This ensures that we can continue to establish TCP
1756 	 * connections even when all local ephemeral ports are already
1757 	 * a part of some TCP connection.  This makes no difference
1758 	 * for UDP sockets, but also doens't harm them.
1759 	 *
1760 	 * If we're asking for any reserved port (i.e. port == 0 &&
1761 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1762 	 * ensure that port is non-zero and we will bind as needed.
1763 	 */
1764 	if (port == 0)
1765 		return 0;
1766 
1767 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1768 	do {
1769 		rpc_set_port((struct sockaddr *)&myaddr, port);
1770 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1771 				transport->xprt.addrlen);
1772 		if (err == 0) {
1773 			transport->srcport = port;
1774 			break;
1775 		}
1776 		last = port;
1777 		port = xs_next_srcport(transport, port);
1778 		if (port > last)
1779 			nloop++;
1780 	} while (err == -EADDRINUSE && nloop != 2);
1781 
1782 	if (myaddr.ss_family == AF_INET)
1783 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1784 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1785 				port, err ? "failed" : "ok", err);
1786 	else
1787 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1788 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1789 				port, err ? "failed" : "ok", err);
1790 	return err;
1791 }
1792 
1793 /*
1794  * We don't support autobind on AF_LOCAL sockets
1795  */
1796 static void xs_local_rpcbind(struct rpc_task *task)
1797 {
1798 	rcu_read_lock();
1799 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1800 	rcu_read_unlock();
1801 }
1802 
1803 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1804 {
1805 }
1806 
1807 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1808 static struct lock_class_key xs_key[2];
1809 static struct lock_class_key xs_slock_key[2];
1810 
1811 static inline void xs_reclassify_socketu(struct socket *sock)
1812 {
1813 	struct sock *sk = sock->sk;
1814 
1815 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1816 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1817 }
1818 
1819 static inline void xs_reclassify_socket4(struct socket *sock)
1820 {
1821 	struct sock *sk = sock->sk;
1822 
1823 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1824 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1825 }
1826 
1827 static inline void xs_reclassify_socket6(struct socket *sock)
1828 {
1829 	struct sock *sk = sock->sk;
1830 
1831 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1832 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1833 }
1834 
1835 static inline void xs_reclassify_socket(int family, struct socket *sock)
1836 {
1837 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1838 	if (sock_owned_by_user(sock->sk))
1839 		return;
1840 
1841 	switch (family) {
1842 	case AF_LOCAL:
1843 		xs_reclassify_socketu(sock);
1844 		break;
1845 	case AF_INET:
1846 		xs_reclassify_socket4(sock);
1847 		break;
1848 	case AF_INET6:
1849 		xs_reclassify_socket6(sock);
1850 		break;
1851 	}
1852 }
1853 #else
1854 static inline void xs_reclassify_socketu(struct socket *sock)
1855 {
1856 }
1857 
1858 static inline void xs_reclassify_socket4(struct socket *sock)
1859 {
1860 }
1861 
1862 static inline void xs_reclassify_socket6(struct socket *sock)
1863 {
1864 }
1865 
1866 static inline void xs_reclassify_socket(int family, struct socket *sock)
1867 {
1868 }
1869 #endif
1870 
1871 static void xs_dummy_setup_socket(struct work_struct *work)
1872 {
1873 }
1874 
1875 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1876 		struct sock_xprt *transport, int family, int type,
1877 		int protocol, bool reuseport)
1878 {
1879 	struct socket *sock;
1880 	int err;
1881 
1882 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1883 	if (err < 0) {
1884 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1885 				protocol, -err);
1886 		goto out;
1887 	}
1888 	xs_reclassify_socket(family, sock);
1889 
1890 	if (reuseport)
1891 		xs_sock_set_reuseport(sock);
1892 
1893 	err = xs_bind(transport, sock);
1894 	if (err) {
1895 		sock_release(sock);
1896 		goto out;
1897 	}
1898 
1899 	return sock;
1900 out:
1901 	return ERR_PTR(err);
1902 }
1903 
1904 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1905 				      struct socket *sock)
1906 {
1907 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1908 									xprt);
1909 
1910 	if (!transport->inet) {
1911 		struct sock *sk = sock->sk;
1912 
1913 		write_lock_bh(&sk->sk_callback_lock);
1914 
1915 		xs_save_old_callbacks(transport, sk);
1916 
1917 		sk->sk_user_data = xprt;
1918 		sk->sk_data_ready = xs_local_data_ready;
1919 		sk->sk_write_space = xs_udp_write_space;
1920 		sk->sk_error_report = xs_error_report;
1921 		sk->sk_allocation = GFP_ATOMIC;
1922 
1923 		xprt_clear_connected(xprt);
1924 
1925 		/* Reset to new socket */
1926 		transport->sock = sock;
1927 		transport->inet = sk;
1928 
1929 		write_unlock_bh(&sk->sk_callback_lock);
1930 	}
1931 
1932 	/* Tell the socket layer to start connecting... */
1933 	xprt->stat.connect_count++;
1934 	xprt->stat.connect_start = jiffies;
1935 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1936 }
1937 
1938 /**
1939  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1940  * @xprt: RPC transport to connect
1941  * @transport: socket transport to connect
1942  * @create_sock: function to create a socket of the correct type
1943  */
1944 static int xs_local_setup_socket(struct sock_xprt *transport)
1945 {
1946 	struct rpc_xprt *xprt = &transport->xprt;
1947 	struct socket *sock;
1948 	int status = -EIO;
1949 
1950 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1951 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1952 					SOCK_STREAM, 0, &sock, 1);
1953 	if (status < 0) {
1954 		dprintk("RPC:       can't create AF_LOCAL "
1955 			"transport socket (%d).\n", -status);
1956 		goto out;
1957 	}
1958 	xs_reclassify_socketu(sock);
1959 
1960 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1961 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1962 
1963 	status = xs_local_finish_connecting(xprt, sock);
1964 	trace_rpc_socket_connect(xprt, sock, status);
1965 	switch (status) {
1966 	case 0:
1967 		dprintk("RPC:       xprt %p connected to %s\n",
1968 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1969 		xprt_set_connected(xprt);
1970 	case -ENOBUFS:
1971 		break;
1972 	case -ENOENT:
1973 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1974 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1975 		break;
1976 	case -ECONNREFUSED:
1977 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1978 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1979 		break;
1980 	default:
1981 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1982 				__func__, -status,
1983 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1984 	}
1985 
1986 out:
1987 	xprt_clear_connecting(xprt);
1988 	xprt_wake_pending_tasks(xprt, status);
1989 	return status;
1990 }
1991 
1992 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1993 {
1994 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1995 	int ret;
1996 
1997 	 if (RPC_IS_ASYNC(task)) {
1998 		/*
1999 		 * We want the AF_LOCAL connect to be resolved in the
2000 		 * filesystem namespace of the process making the rpc
2001 		 * call.  Thus we connect synchronously.
2002 		 *
2003 		 * If we want to support asynchronous AF_LOCAL calls,
2004 		 * we'll need to figure out how to pass a namespace to
2005 		 * connect.
2006 		 */
2007 		rpc_exit(task, -ENOTCONN);
2008 		return;
2009 	}
2010 	ret = xs_local_setup_socket(transport);
2011 	if (ret && !RPC_IS_SOFTCONN(task))
2012 		msleep_interruptible(15000);
2013 }
2014 
2015 #ifdef CONFIG_SUNRPC_SWAP
2016 static void xs_set_memalloc(struct rpc_xprt *xprt)
2017 {
2018 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2019 			xprt);
2020 
2021 	if (xprt->swapper)
2022 		sk_set_memalloc(transport->inet);
2023 }
2024 
2025 /**
2026  * xs_swapper - Tag this transport as being used for swap.
2027  * @xprt: transport to tag
2028  * @enable: enable/disable
2029  *
2030  */
2031 int xs_swapper(struct rpc_xprt *xprt, int enable)
2032 {
2033 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2034 			xprt);
2035 	int err = 0;
2036 
2037 	if (enable) {
2038 		xprt->swapper++;
2039 		xs_set_memalloc(xprt);
2040 	} else if (xprt->swapper) {
2041 		xprt->swapper--;
2042 		sk_clear_memalloc(transport->inet);
2043 	}
2044 
2045 	return err;
2046 }
2047 EXPORT_SYMBOL_GPL(xs_swapper);
2048 #else
2049 static void xs_set_memalloc(struct rpc_xprt *xprt)
2050 {
2051 }
2052 #endif
2053 
2054 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2055 {
2056 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2057 
2058 	if (!transport->inet) {
2059 		struct sock *sk = sock->sk;
2060 
2061 		write_lock_bh(&sk->sk_callback_lock);
2062 
2063 		xs_save_old_callbacks(transport, sk);
2064 
2065 		sk->sk_user_data = xprt;
2066 		sk->sk_data_ready = xs_udp_data_ready;
2067 		sk->sk_write_space = xs_udp_write_space;
2068 		sk->sk_allocation = GFP_ATOMIC;
2069 
2070 		xprt_set_connected(xprt);
2071 
2072 		/* Reset to new socket */
2073 		transport->sock = sock;
2074 		transport->inet = sk;
2075 
2076 		xs_set_memalloc(xprt);
2077 
2078 		write_unlock_bh(&sk->sk_callback_lock);
2079 	}
2080 	xs_udp_do_set_buffer_size(xprt);
2081 }
2082 
2083 static void xs_udp_setup_socket(struct work_struct *work)
2084 {
2085 	struct sock_xprt *transport =
2086 		container_of(work, struct sock_xprt, connect_worker.work);
2087 	struct rpc_xprt *xprt = &transport->xprt;
2088 	struct socket *sock = transport->sock;
2089 	int status = -EIO;
2090 
2091 	/* Start by resetting any existing state */
2092 	xs_reset_transport(transport);
2093 	sock = xs_create_sock(xprt, transport,
2094 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2095 			IPPROTO_UDP, false);
2096 	if (IS_ERR(sock))
2097 		goto out;
2098 
2099 	dprintk("RPC:       worker connecting xprt %p via %s to "
2100 				"%s (port %s)\n", xprt,
2101 			xprt->address_strings[RPC_DISPLAY_PROTO],
2102 			xprt->address_strings[RPC_DISPLAY_ADDR],
2103 			xprt->address_strings[RPC_DISPLAY_PORT]);
2104 
2105 	xs_udp_finish_connecting(xprt, sock);
2106 	trace_rpc_socket_connect(xprt, sock, 0);
2107 	status = 0;
2108 out:
2109 	xprt_clear_connecting(xprt);
2110 	xprt_wake_pending_tasks(xprt, status);
2111 }
2112 
2113 /*
2114  * We need to preserve the port number so the reply cache on the server can
2115  * find our cached RPC replies when we get around to reconnecting.
2116  */
2117 static void xs_abort_connection(struct sock_xprt *transport)
2118 {
2119 	int result;
2120 	struct sockaddr any;
2121 
2122 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2123 
2124 	/*
2125 	 * Disconnect the transport socket by doing a connect operation
2126 	 * with AF_UNSPEC.  This should return immediately...
2127 	 */
2128 	memset(&any, 0, sizeof(any));
2129 	any.sa_family = AF_UNSPEC;
2130 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2131 	trace_rpc_socket_reset_connection(&transport->xprt,
2132 			transport->sock, result);
2133 	if (!result)
2134 		xs_sock_reset_connection_flags(&transport->xprt);
2135 	dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2136 }
2137 
2138 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2139 {
2140 	unsigned int state = transport->inet->sk_state;
2141 
2142 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2143 		/* we don't need to abort the connection if the socket
2144 		 * hasn't undergone a shutdown
2145 		 */
2146 		if (transport->inet->sk_shutdown == 0)
2147 			return;
2148 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2149 				__func__, transport->inet->sk_shutdown);
2150 	}
2151 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2152 		/* we don't need to abort the connection if the socket
2153 		 * hasn't undergone a shutdown
2154 		 */
2155 		if (transport->inet->sk_shutdown == 0)
2156 			return;
2157 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2158 				"sk_shutdown set to %d\n",
2159 				__func__, transport->inet->sk_shutdown);
2160 	}
2161 	xs_abort_connection(transport);
2162 }
2163 
2164 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2165 {
2166 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2167 	int ret = -ENOTCONN;
2168 
2169 	if (!transport->inet) {
2170 		struct sock *sk = sock->sk;
2171 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2172 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2173 		unsigned int opt_on = 1;
2174 
2175 		/* TCP Keepalive options */
2176 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2177 				(char *)&opt_on, sizeof(opt_on));
2178 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2179 				(char *)&keepidle, sizeof(keepidle));
2180 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2181 				(char *)&keepidle, sizeof(keepidle));
2182 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2183 				(char *)&keepcnt, sizeof(keepcnt));
2184 
2185 		write_lock_bh(&sk->sk_callback_lock);
2186 
2187 		xs_save_old_callbacks(transport, sk);
2188 
2189 		sk->sk_user_data = xprt;
2190 		sk->sk_data_ready = xs_tcp_data_ready;
2191 		sk->sk_state_change = xs_tcp_state_change;
2192 		sk->sk_write_space = xs_tcp_write_space;
2193 		sk->sk_error_report = xs_error_report;
2194 		sk->sk_allocation = GFP_ATOMIC;
2195 
2196 		/* socket options */
2197 		sock_reset_flag(sk, SOCK_LINGER);
2198 		tcp_sk(sk)->linger2 = 0;
2199 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2200 
2201 		xprt_clear_connected(xprt);
2202 
2203 		/* Reset to new socket */
2204 		transport->sock = sock;
2205 		transport->inet = sk;
2206 
2207 		write_unlock_bh(&sk->sk_callback_lock);
2208 	}
2209 
2210 	if (!xprt_bound(xprt))
2211 		goto out;
2212 
2213 	xs_set_memalloc(xprt);
2214 
2215 	/* Tell the socket layer to start connecting... */
2216 	xprt->stat.connect_count++;
2217 	xprt->stat.connect_start = jiffies;
2218 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2219 	switch (ret) {
2220 	case 0:
2221 		xs_set_srcport(transport, sock);
2222 	case -EINPROGRESS:
2223 		/* SYN_SENT! */
2224 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2225 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2226 	}
2227 out:
2228 	return ret;
2229 }
2230 
2231 /**
2232  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2233  * @xprt: RPC transport to connect
2234  * @transport: socket transport to connect
2235  * @create_sock: function to create a socket of the correct type
2236  *
2237  * Invoked by a work queue tasklet.
2238  */
2239 static void xs_tcp_setup_socket(struct work_struct *work)
2240 {
2241 	struct sock_xprt *transport =
2242 		container_of(work, struct sock_xprt, connect_worker.work);
2243 	struct socket *sock = transport->sock;
2244 	struct rpc_xprt *xprt = &transport->xprt;
2245 	int status = -EIO;
2246 
2247 	if (!sock) {
2248 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2249 		sock = xs_create_sock(xprt, transport,
2250 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2251 				IPPROTO_TCP, true);
2252 		if (IS_ERR(sock)) {
2253 			status = PTR_ERR(sock);
2254 			goto out;
2255 		}
2256 	} else {
2257 		int abort_and_exit;
2258 
2259 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2260 				&xprt->state);
2261 		/* "close" the socket, preserving the local port */
2262 		set_bit(XPRT_CONNECTION_REUSE, &xprt->state);
2263 		xs_tcp_reuse_connection(transport);
2264 		clear_bit(XPRT_CONNECTION_REUSE, &xprt->state);
2265 
2266 		if (abort_and_exit)
2267 			goto out_eagain;
2268 	}
2269 
2270 	dprintk("RPC:       worker connecting xprt %p via %s to "
2271 				"%s (port %s)\n", xprt,
2272 			xprt->address_strings[RPC_DISPLAY_PROTO],
2273 			xprt->address_strings[RPC_DISPLAY_ADDR],
2274 			xprt->address_strings[RPC_DISPLAY_PORT]);
2275 
2276 	status = xs_tcp_finish_connecting(xprt, sock);
2277 	trace_rpc_socket_connect(xprt, sock, status);
2278 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2279 			xprt, -status, xprt_connected(xprt),
2280 			sock->sk->sk_state);
2281 	switch (status) {
2282 	default:
2283 		printk("%s: connect returned unhandled error %d\n",
2284 			__func__, status);
2285 	case -EADDRNOTAVAIL:
2286 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2287 		 * and retry
2288 		 */
2289 		xs_tcp_force_close(xprt);
2290 		break;
2291 	case 0:
2292 	case -EINPROGRESS:
2293 	case -EALREADY:
2294 		xprt_clear_connecting(xprt);
2295 		return;
2296 	case -EINVAL:
2297 		/* Happens, for instance, if the user specified a link
2298 		 * local IPv6 address without a scope-id.
2299 		 */
2300 	case -ECONNREFUSED:
2301 	case -ECONNRESET:
2302 	case -ENETUNREACH:
2303 	case -EADDRINUSE:
2304 	case -ENOBUFS:
2305 		/* retry with existing socket, after a delay */
2306 		goto out;
2307 	}
2308 out_eagain:
2309 	status = -EAGAIN;
2310 out:
2311 	xprt_clear_connecting(xprt);
2312 	xprt_wake_pending_tasks(xprt, status);
2313 }
2314 
2315 /**
2316  * xs_connect - connect a socket to a remote endpoint
2317  * @xprt: pointer to transport structure
2318  * @task: address of RPC task that manages state of connect request
2319  *
2320  * TCP: If the remote end dropped the connection, delay reconnecting.
2321  *
2322  * UDP socket connects are synchronous, but we use a work queue anyway
2323  * to guarantee that even unprivileged user processes can set up a
2324  * socket on a privileged port.
2325  *
2326  * If a UDP socket connect fails, the delay behavior here prevents
2327  * retry floods (hard mounts).
2328  */
2329 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2330 {
2331 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2332 
2333 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2334 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2335 				"seconds\n",
2336 				xprt, xprt->reestablish_timeout / HZ);
2337 		queue_delayed_work(rpciod_workqueue,
2338 				   &transport->connect_worker,
2339 				   xprt->reestablish_timeout);
2340 		xprt->reestablish_timeout <<= 1;
2341 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2342 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2343 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2344 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2345 	} else {
2346 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2347 		queue_delayed_work(rpciod_workqueue,
2348 				   &transport->connect_worker, 0);
2349 	}
2350 }
2351 
2352 /**
2353  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2354  * @xprt: rpc_xprt struct containing statistics
2355  * @seq: output file
2356  *
2357  */
2358 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2359 {
2360 	long idle_time = 0;
2361 
2362 	if (xprt_connected(xprt))
2363 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2364 
2365 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2366 			"%llu %llu %lu %llu %llu\n",
2367 			xprt->stat.bind_count,
2368 			xprt->stat.connect_count,
2369 			xprt->stat.connect_time,
2370 			idle_time,
2371 			xprt->stat.sends,
2372 			xprt->stat.recvs,
2373 			xprt->stat.bad_xids,
2374 			xprt->stat.req_u,
2375 			xprt->stat.bklog_u,
2376 			xprt->stat.max_slots,
2377 			xprt->stat.sending_u,
2378 			xprt->stat.pending_u);
2379 }
2380 
2381 /**
2382  * xs_udp_print_stats - display UDP socket-specifc stats
2383  * @xprt: rpc_xprt struct containing statistics
2384  * @seq: output file
2385  *
2386  */
2387 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2388 {
2389 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2390 
2391 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2392 			"%lu %llu %llu\n",
2393 			transport->srcport,
2394 			xprt->stat.bind_count,
2395 			xprt->stat.sends,
2396 			xprt->stat.recvs,
2397 			xprt->stat.bad_xids,
2398 			xprt->stat.req_u,
2399 			xprt->stat.bklog_u,
2400 			xprt->stat.max_slots,
2401 			xprt->stat.sending_u,
2402 			xprt->stat.pending_u);
2403 }
2404 
2405 /**
2406  * xs_tcp_print_stats - display TCP socket-specifc stats
2407  * @xprt: rpc_xprt struct containing statistics
2408  * @seq: output file
2409  *
2410  */
2411 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2412 {
2413 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2414 	long idle_time = 0;
2415 
2416 	if (xprt_connected(xprt))
2417 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2418 
2419 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2420 			"%llu %llu %lu %llu %llu\n",
2421 			transport->srcport,
2422 			xprt->stat.bind_count,
2423 			xprt->stat.connect_count,
2424 			xprt->stat.connect_time,
2425 			idle_time,
2426 			xprt->stat.sends,
2427 			xprt->stat.recvs,
2428 			xprt->stat.bad_xids,
2429 			xprt->stat.req_u,
2430 			xprt->stat.bklog_u,
2431 			xprt->stat.max_slots,
2432 			xprt->stat.sending_u,
2433 			xprt->stat.pending_u);
2434 }
2435 
2436 /*
2437  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2438  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2439  * to use the server side send routines.
2440  */
2441 static void *bc_malloc(struct rpc_task *task, size_t size)
2442 {
2443 	struct page *page;
2444 	struct rpc_buffer *buf;
2445 
2446 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2447 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2448 		return NULL;
2449 
2450 	page = alloc_page(GFP_KERNEL);
2451 	if (!page)
2452 		return NULL;
2453 
2454 	buf = page_address(page);
2455 	buf->len = PAGE_SIZE;
2456 
2457 	return buf->data;
2458 }
2459 
2460 /*
2461  * Free the space allocated in the bc_alloc routine
2462  */
2463 static void bc_free(void *buffer)
2464 {
2465 	struct rpc_buffer *buf;
2466 
2467 	if (!buffer)
2468 		return;
2469 
2470 	buf = container_of(buffer, struct rpc_buffer, data);
2471 	free_page((unsigned long)buf);
2472 }
2473 
2474 /*
2475  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2476  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2477  */
2478 static int bc_sendto(struct rpc_rqst *req)
2479 {
2480 	int len;
2481 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2482 	struct rpc_xprt *xprt = req->rq_xprt;
2483 	struct sock_xprt *transport =
2484 				container_of(xprt, struct sock_xprt, xprt);
2485 	struct socket *sock = transport->sock;
2486 	unsigned long headoff;
2487 	unsigned long tailoff;
2488 
2489 	xs_encode_stream_record_marker(xbufp);
2490 
2491 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2492 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2493 	len = svc_send_common(sock, xbufp,
2494 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2495 			      xbufp->tail[0].iov_base, tailoff);
2496 
2497 	if (len != xbufp->len) {
2498 		printk(KERN_NOTICE "Error sending entire callback!\n");
2499 		len = -EAGAIN;
2500 	}
2501 
2502 	return len;
2503 }
2504 
2505 /*
2506  * The send routine. Borrows from svc_send
2507  */
2508 static int bc_send_request(struct rpc_task *task)
2509 {
2510 	struct rpc_rqst *req = task->tk_rqstp;
2511 	struct svc_xprt	*xprt;
2512 	u32                     len;
2513 
2514 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2515 	/*
2516 	 * Get the server socket associated with this callback xprt
2517 	 */
2518 	xprt = req->rq_xprt->bc_xprt;
2519 
2520 	/*
2521 	 * Grab the mutex to serialize data as the connection is shared
2522 	 * with the fore channel
2523 	 */
2524 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2525 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2526 		if (!mutex_trylock(&xprt->xpt_mutex))
2527 			return -EAGAIN;
2528 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2529 	}
2530 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2531 		len = -ENOTCONN;
2532 	else
2533 		len = bc_sendto(req);
2534 	mutex_unlock(&xprt->xpt_mutex);
2535 
2536 	if (len > 0)
2537 		len = 0;
2538 
2539 	return len;
2540 }
2541 
2542 /*
2543  * The close routine. Since this is client initiated, we do nothing
2544  */
2545 
2546 static void bc_close(struct rpc_xprt *xprt)
2547 {
2548 }
2549 
2550 /*
2551  * The xprt destroy routine. Again, because this connection is client
2552  * initiated, we do nothing
2553  */
2554 
2555 static void bc_destroy(struct rpc_xprt *xprt)
2556 {
2557 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2558 
2559 	xs_xprt_free(xprt);
2560 	module_put(THIS_MODULE);
2561 }
2562 
2563 static struct rpc_xprt_ops xs_local_ops = {
2564 	.reserve_xprt		= xprt_reserve_xprt,
2565 	.release_xprt		= xs_tcp_release_xprt,
2566 	.alloc_slot		= xprt_alloc_slot,
2567 	.rpcbind		= xs_local_rpcbind,
2568 	.set_port		= xs_local_set_port,
2569 	.connect		= xs_local_connect,
2570 	.buf_alloc		= rpc_malloc,
2571 	.buf_free		= rpc_free,
2572 	.send_request		= xs_local_send_request,
2573 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2574 	.close			= xs_close,
2575 	.destroy		= xs_destroy,
2576 	.print_stats		= xs_local_print_stats,
2577 };
2578 
2579 static struct rpc_xprt_ops xs_udp_ops = {
2580 	.set_buffer_size	= xs_udp_set_buffer_size,
2581 	.reserve_xprt		= xprt_reserve_xprt_cong,
2582 	.release_xprt		= xprt_release_xprt_cong,
2583 	.alloc_slot		= xprt_alloc_slot,
2584 	.rpcbind		= rpcb_getport_async,
2585 	.set_port		= xs_set_port,
2586 	.connect		= xs_connect,
2587 	.buf_alloc		= rpc_malloc,
2588 	.buf_free		= rpc_free,
2589 	.send_request		= xs_udp_send_request,
2590 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2591 	.timer			= xs_udp_timer,
2592 	.release_request	= xprt_release_rqst_cong,
2593 	.close			= xs_close,
2594 	.destroy		= xs_destroy,
2595 	.print_stats		= xs_udp_print_stats,
2596 };
2597 
2598 static struct rpc_xprt_ops xs_tcp_ops = {
2599 	.reserve_xprt		= xprt_reserve_xprt,
2600 	.release_xprt		= xs_tcp_release_xprt,
2601 	.alloc_slot		= xprt_lock_and_alloc_slot,
2602 	.rpcbind		= rpcb_getport_async,
2603 	.set_port		= xs_set_port,
2604 	.connect		= xs_connect,
2605 	.buf_alloc		= rpc_malloc,
2606 	.buf_free		= rpc_free,
2607 	.send_request		= xs_tcp_send_request,
2608 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2609 	.close			= xs_tcp_close,
2610 	.destroy		= xs_destroy,
2611 	.print_stats		= xs_tcp_print_stats,
2612 };
2613 
2614 /*
2615  * The rpc_xprt_ops for the server backchannel
2616  */
2617 
2618 static struct rpc_xprt_ops bc_tcp_ops = {
2619 	.reserve_xprt		= xprt_reserve_xprt,
2620 	.release_xprt		= xprt_release_xprt,
2621 	.alloc_slot		= xprt_alloc_slot,
2622 	.buf_alloc		= bc_malloc,
2623 	.buf_free		= bc_free,
2624 	.send_request		= bc_send_request,
2625 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2626 	.close			= bc_close,
2627 	.destroy		= bc_destroy,
2628 	.print_stats		= xs_tcp_print_stats,
2629 };
2630 
2631 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2632 {
2633 	static const struct sockaddr_in sin = {
2634 		.sin_family		= AF_INET,
2635 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2636 	};
2637 	static const struct sockaddr_in6 sin6 = {
2638 		.sin6_family		= AF_INET6,
2639 		.sin6_addr		= IN6ADDR_ANY_INIT,
2640 	};
2641 
2642 	switch (family) {
2643 	case AF_LOCAL:
2644 		break;
2645 	case AF_INET:
2646 		memcpy(sap, &sin, sizeof(sin));
2647 		break;
2648 	case AF_INET6:
2649 		memcpy(sap, &sin6, sizeof(sin6));
2650 		break;
2651 	default:
2652 		dprintk("RPC:       %s: Bad address family\n", __func__);
2653 		return -EAFNOSUPPORT;
2654 	}
2655 	return 0;
2656 }
2657 
2658 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2659 				      unsigned int slot_table_size,
2660 				      unsigned int max_slot_table_size)
2661 {
2662 	struct rpc_xprt *xprt;
2663 	struct sock_xprt *new;
2664 
2665 	if (args->addrlen > sizeof(xprt->addr)) {
2666 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2667 		return ERR_PTR(-EBADF);
2668 	}
2669 
2670 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2671 			max_slot_table_size);
2672 	if (xprt == NULL) {
2673 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2674 				"rpc_xprt\n");
2675 		return ERR_PTR(-ENOMEM);
2676 	}
2677 
2678 	new = container_of(xprt, struct sock_xprt, xprt);
2679 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2680 	xprt->addrlen = args->addrlen;
2681 	if (args->srcaddr)
2682 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2683 	else {
2684 		int err;
2685 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2686 					(struct sockaddr *)&new->srcaddr);
2687 		if (err != 0) {
2688 			xprt_free(xprt);
2689 			return ERR_PTR(err);
2690 		}
2691 	}
2692 
2693 	return xprt;
2694 }
2695 
2696 static const struct rpc_timeout xs_local_default_timeout = {
2697 	.to_initval = 10 * HZ,
2698 	.to_maxval = 10 * HZ,
2699 	.to_retries = 2,
2700 };
2701 
2702 /**
2703  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2704  * @args: rpc transport creation arguments
2705  *
2706  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2707  */
2708 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2709 {
2710 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2711 	struct sock_xprt *transport;
2712 	struct rpc_xprt *xprt;
2713 	struct rpc_xprt *ret;
2714 
2715 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2716 			xprt_max_tcp_slot_table_entries);
2717 	if (IS_ERR(xprt))
2718 		return xprt;
2719 	transport = container_of(xprt, struct sock_xprt, xprt);
2720 
2721 	xprt->prot = 0;
2722 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2723 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2724 
2725 	xprt->bind_timeout = XS_BIND_TO;
2726 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2727 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2728 
2729 	xprt->ops = &xs_local_ops;
2730 	xprt->timeout = &xs_local_default_timeout;
2731 
2732 	INIT_DELAYED_WORK(&transport->connect_worker,
2733 			xs_dummy_setup_socket);
2734 
2735 	switch (sun->sun_family) {
2736 	case AF_LOCAL:
2737 		if (sun->sun_path[0] != '/') {
2738 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2739 					sun->sun_path);
2740 			ret = ERR_PTR(-EINVAL);
2741 			goto out_err;
2742 		}
2743 		xprt_set_bound(xprt);
2744 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2745 		ret = ERR_PTR(xs_local_setup_socket(transport));
2746 		if (ret)
2747 			goto out_err;
2748 		break;
2749 	default:
2750 		ret = ERR_PTR(-EAFNOSUPPORT);
2751 		goto out_err;
2752 	}
2753 
2754 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2755 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2756 
2757 	if (try_module_get(THIS_MODULE))
2758 		return xprt;
2759 	ret = ERR_PTR(-EINVAL);
2760 out_err:
2761 	xs_xprt_free(xprt);
2762 	return ret;
2763 }
2764 
2765 static const struct rpc_timeout xs_udp_default_timeout = {
2766 	.to_initval = 5 * HZ,
2767 	.to_maxval = 30 * HZ,
2768 	.to_increment = 5 * HZ,
2769 	.to_retries = 5,
2770 };
2771 
2772 /**
2773  * xs_setup_udp - Set up transport to use a UDP socket
2774  * @args: rpc transport creation arguments
2775  *
2776  */
2777 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2778 {
2779 	struct sockaddr *addr = args->dstaddr;
2780 	struct rpc_xprt *xprt;
2781 	struct sock_xprt *transport;
2782 	struct rpc_xprt *ret;
2783 
2784 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2785 			xprt_udp_slot_table_entries);
2786 	if (IS_ERR(xprt))
2787 		return xprt;
2788 	transport = container_of(xprt, struct sock_xprt, xprt);
2789 
2790 	xprt->prot = IPPROTO_UDP;
2791 	xprt->tsh_size = 0;
2792 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2793 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2794 
2795 	xprt->bind_timeout = XS_BIND_TO;
2796 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2797 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2798 
2799 	xprt->ops = &xs_udp_ops;
2800 
2801 	xprt->timeout = &xs_udp_default_timeout;
2802 
2803 	switch (addr->sa_family) {
2804 	case AF_INET:
2805 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2806 			xprt_set_bound(xprt);
2807 
2808 		INIT_DELAYED_WORK(&transport->connect_worker,
2809 					xs_udp_setup_socket);
2810 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2811 		break;
2812 	case AF_INET6:
2813 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2814 			xprt_set_bound(xprt);
2815 
2816 		INIT_DELAYED_WORK(&transport->connect_worker,
2817 					xs_udp_setup_socket);
2818 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2819 		break;
2820 	default:
2821 		ret = ERR_PTR(-EAFNOSUPPORT);
2822 		goto out_err;
2823 	}
2824 
2825 	if (xprt_bound(xprt))
2826 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2827 				xprt->address_strings[RPC_DISPLAY_ADDR],
2828 				xprt->address_strings[RPC_DISPLAY_PORT],
2829 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2830 	else
2831 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2832 				xprt->address_strings[RPC_DISPLAY_ADDR],
2833 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2834 
2835 	if (try_module_get(THIS_MODULE))
2836 		return xprt;
2837 	ret = ERR_PTR(-EINVAL);
2838 out_err:
2839 	xs_xprt_free(xprt);
2840 	return ret;
2841 }
2842 
2843 static const struct rpc_timeout xs_tcp_default_timeout = {
2844 	.to_initval = 60 * HZ,
2845 	.to_maxval = 60 * HZ,
2846 	.to_retries = 2,
2847 };
2848 
2849 /**
2850  * xs_setup_tcp - Set up transport to use a TCP socket
2851  * @args: rpc transport creation arguments
2852  *
2853  */
2854 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2855 {
2856 	struct sockaddr *addr = args->dstaddr;
2857 	struct rpc_xprt *xprt;
2858 	struct sock_xprt *transport;
2859 	struct rpc_xprt *ret;
2860 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2861 
2862 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2863 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2864 
2865 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2866 			max_slot_table_size);
2867 	if (IS_ERR(xprt))
2868 		return xprt;
2869 	transport = container_of(xprt, struct sock_xprt, xprt);
2870 
2871 	xprt->prot = IPPROTO_TCP;
2872 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2873 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2874 
2875 	xprt->bind_timeout = XS_BIND_TO;
2876 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2877 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2878 
2879 	xprt->ops = &xs_tcp_ops;
2880 	xprt->timeout = &xs_tcp_default_timeout;
2881 
2882 	switch (addr->sa_family) {
2883 	case AF_INET:
2884 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2885 			xprt_set_bound(xprt);
2886 
2887 		INIT_DELAYED_WORK(&transport->connect_worker,
2888 					xs_tcp_setup_socket);
2889 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2890 		break;
2891 	case AF_INET6:
2892 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2893 			xprt_set_bound(xprt);
2894 
2895 		INIT_DELAYED_WORK(&transport->connect_worker,
2896 					xs_tcp_setup_socket);
2897 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2898 		break;
2899 	default:
2900 		ret = ERR_PTR(-EAFNOSUPPORT);
2901 		goto out_err;
2902 	}
2903 
2904 	if (xprt_bound(xprt))
2905 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2906 				xprt->address_strings[RPC_DISPLAY_ADDR],
2907 				xprt->address_strings[RPC_DISPLAY_PORT],
2908 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2909 	else
2910 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2911 				xprt->address_strings[RPC_DISPLAY_ADDR],
2912 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2913 
2914 	if (try_module_get(THIS_MODULE))
2915 		return xprt;
2916 	ret = ERR_PTR(-EINVAL);
2917 out_err:
2918 	xs_xprt_free(xprt);
2919 	return ret;
2920 }
2921 
2922 /**
2923  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2924  * @args: rpc transport creation arguments
2925  *
2926  */
2927 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2928 {
2929 	struct sockaddr *addr = args->dstaddr;
2930 	struct rpc_xprt *xprt;
2931 	struct sock_xprt *transport;
2932 	struct svc_sock *bc_sock;
2933 	struct rpc_xprt *ret;
2934 
2935 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2936 			xprt_tcp_slot_table_entries);
2937 	if (IS_ERR(xprt))
2938 		return xprt;
2939 	transport = container_of(xprt, struct sock_xprt, xprt);
2940 
2941 	xprt->prot = IPPROTO_TCP;
2942 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2943 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2944 	xprt->timeout = &xs_tcp_default_timeout;
2945 
2946 	/* backchannel */
2947 	xprt_set_bound(xprt);
2948 	xprt->bind_timeout = 0;
2949 	xprt->reestablish_timeout = 0;
2950 	xprt->idle_timeout = 0;
2951 
2952 	xprt->ops = &bc_tcp_ops;
2953 
2954 	switch (addr->sa_family) {
2955 	case AF_INET:
2956 		xs_format_peer_addresses(xprt, "tcp",
2957 					 RPCBIND_NETID_TCP);
2958 		break;
2959 	case AF_INET6:
2960 		xs_format_peer_addresses(xprt, "tcp",
2961 				   RPCBIND_NETID_TCP6);
2962 		break;
2963 	default:
2964 		ret = ERR_PTR(-EAFNOSUPPORT);
2965 		goto out_err;
2966 	}
2967 
2968 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2969 			xprt->address_strings[RPC_DISPLAY_ADDR],
2970 			xprt->address_strings[RPC_DISPLAY_PORT],
2971 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2972 
2973 	/*
2974 	 * Once we've associated a backchannel xprt with a connection,
2975 	 * we want to keep it around as long as the connection lasts,
2976 	 * in case we need to start using it for a backchannel again;
2977 	 * this reference won't be dropped until bc_xprt is destroyed.
2978 	 */
2979 	xprt_get(xprt);
2980 	args->bc_xprt->xpt_bc_xprt = xprt;
2981 	xprt->bc_xprt = args->bc_xprt;
2982 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2983 	transport->sock = bc_sock->sk_sock;
2984 	transport->inet = bc_sock->sk_sk;
2985 
2986 	/*
2987 	 * Since we don't want connections for the backchannel, we set
2988 	 * the xprt status to connected
2989 	 */
2990 	xprt_set_connected(xprt);
2991 
2992 	if (try_module_get(THIS_MODULE))
2993 		return xprt;
2994 
2995 	args->bc_xprt->xpt_bc_xprt = NULL;
2996 	xprt_put(xprt);
2997 	ret = ERR_PTR(-EINVAL);
2998 out_err:
2999 	xs_xprt_free(xprt);
3000 	return ret;
3001 }
3002 
3003 static struct xprt_class	xs_local_transport = {
3004 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3005 	.name		= "named UNIX socket",
3006 	.owner		= THIS_MODULE,
3007 	.ident		= XPRT_TRANSPORT_LOCAL,
3008 	.setup		= xs_setup_local,
3009 };
3010 
3011 static struct xprt_class	xs_udp_transport = {
3012 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3013 	.name		= "udp",
3014 	.owner		= THIS_MODULE,
3015 	.ident		= XPRT_TRANSPORT_UDP,
3016 	.setup		= xs_setup_udp,
3017 };
3018 
3019 static struct xprt_class	xs_tcp_transport = {
3020 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3021 	.name		= "tcp",
3022 	.owner		= THIS_MODULE,
3023 	.ident		= XPRT_TRANSPORT_TCP,
3024 	.setup		= xs_setup_tcp,
3025 };
3026 
3027 static struct xprt_class	xs_bc_tcp_transport = {
3028 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3029 	.name		= "tcp NFSv4.1 backchannel",
3030 	.owner		= THIS_MODULE,
3031 	.ident		= XPRT_TRANSPORT_BC_TCP,
3032 	.setup		= xs_setup_bc_tcp,
3033 };
3034 
3035 /**
3036  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3037  *
3038  */
3039 int init_socket_xprt(void)
3040 {
3041 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3042 	if (!sunrpc_table_header)
3043 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3044 #endif
3045 
3046 	xprt_register_transport(&xs_local_transport);
3047 	xprt_register_transport(&xs_udp_transport);
3048 	xprt_register_transport(&xs_tcp_transport);
3049 	xprt_register_transport(&xs_bc_tcp_transport);
3050 
3051 	return 0;
3052 }
3053 
3054 /**
3055  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3056  *
3057  */
3058 void cleanup_socket_xprt(void)
3059 {
3060 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3061 	if (sunrpc_table_header) {
3062 		unregister_sysctl_table(sunrpc_table_header);
3063 		sunrpc_table_header = NULL;
3064 	}
3065 #endif
3066 
3067 	xprt_unregister_transport(&xs_local_transport);
3068 	xprt_unregister_transport(&xs_udp_transport);
3069 	xprt_unregister_transport(&xs_tcp_transport);
3070 	xprt_unregister_transport(&xs_bc_tcp_transport);
3071 }
3072 
3073 static int param_set_uint_minmax(const char *val,
3074 		const struct kernel_param *kp,
3075 		unsigned int min, unsigned int max)
3076 {
3077 	unsigned int num;
3078 	int ret;
3079 
3080 	if (!val)
3081 		return -EINVAL;
3082 	ret = kstrtouint(val, 0, &num);
3083 	if (ret == -EINVAL || num < min || num > max)
3084 		return -EINVAL;
3085 	*((unsigned int *)kp->arg) = num;
3086 	return 0;
3087 }
3088 
3089 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3090 {
3091 	return param_set_uint_minmax(val, kp,
3092 			RPC_MIN_RESVPORT,
3093 			RPC_MAX_RESVPORT);
3094 }
3095 
3096 static struct kernel_param_ops param_ops_portnr = {
3097 	.set = param_set_portnr,
3098 	.get = param_get_uint,
3099 };
3100 
3101 #define param_check_portnr(name, p) \
3102 	__param_check(name, p, unsigned int);
3103 
3104 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3105 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3106 
3107 static int param_set_slot_table_size(const char *val,
3108 				     const struct kernel_param *kp)
3109 {
3110 	return param_set_uint_minmax(val, kp,
3111 			RPC_MIN_SLOT_TABLE,
3112 			RPC_MAX_SLOT_TABLE);
3113 }
3114 
3115 static struct kernel_param_ops param_ops_slot_table_size = {
3116 	.set = param_set_slot_table_size,
3117 	.get = param_get_uint,
3118 };
3119 
3120 #define param_check_slot_table_size(name, p) \
3121 	__param_check(name, p, unsigned int);
3122 
3123 static int param_set_max_slot_table_size(const char *val,
3124 				     const struct kernel_param *kp)
3125 {
3126 	return param_set_uint_minmax(val, kp,
3127 			RPC_MIN_SLOT_TABLE,
3128 			RPC_MAX_SLOT_TABLE_LIMIT);
3129 }
3130 
3131 static struct kernel_param_ops param_ops_max_slot_table_size = {
3132 	.set = param_set_max_slot_table_size,
3133 	.get = param_get_uint,
3134 };
3135 
3136 #define param_check_max_slot_table_size(name, p) \
3137 	__param_check(name, p, unsigned int);
3138 
3139 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3140 		   slot_table_size, 0644);
3141 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3142 		   max_slot_table_size, 0644);
3143 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3144 		   slot_table_size, 0644);
3145 
3146