xref: /linux/net/sunrpc/xprtsock.c (revision 55f3538c4923e9dfca132e99ebec370e8094afda)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 
51 #include <trace/events/sunrpc.h>
52 
53 #include "sunrpc.h"
54 
55 #define RPC_TCP_READ_CHUNK_SZ	(3*512*1024)
56 
57 static void xs_close(struct rpc_xprt *xprt);
58 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
59 		struct socket *sock);
60 
61 /*
62  * xprtsock tunables
63  */
64 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
65 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
66 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
67 
68 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
69 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
70 
71 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
72 
73 #define XS_TCP_LINGER_TO	(15U * HZ)
74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
75 
76 /*
77  * We can register our own files under /proc/sys/sunrpc by
78  * calling register_sysctl_table() again.  The files in that
79  * directory become the union of all files registered there.
80  *
81  * We simply need to make sure that we don't collide with
82  * someone else's file names!
83  */
84 
85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
90 
91 static struct ctl_table_header *sunrpc_table_header;
92 
93 /*
94  * FIXME: changing the UDP slot table size should also resize the UDP
95  *        socket buffers for existing UDP transports
96  */
97 static struct ctl_table xs_tunables_table[] = {
98 	{
99 		.procname	= "udp_slot_table_entries",
100 		.data		= &xprt_udp_slot_table_entries,
101 		.maxlen		= sizeof(unsigned int),
102 		.mode		= 0644,
103 		.proc_handler	= proc_dointvec_minmax,
104 		.extra1		= &min_slot_table_size,
105 		.extra2		= &max_slot_table_size
106 	},
107 	{
108 		.procname	= "tcp_slot_table_entries",
109 		.data		= &xprt_tcp_slot_table_entries,
110 		.maxlen		= sizeof(unsigned int),
111 		.mode		= 0644,
112 		.proc_handler	= proc_dointvec_minmax,
113 		.extra1		= &min_slot_table_size,
114 		.extra2		= &max_slot_table_size
115 	},
116 	{
117 		.procname	= "tcp_max_slot_table_entries",
118 		.data		= &xprt_max_tcp_slot_table_entries,
119 		.maxlen		= sizeof(unsigned int),
120 		.mode		= 0644,
121 		.proc_handler	= proc_dointvec_minmax,
122 		.extra1		= &min_slot_table_size,
123 		.extra2		= &max_tcp_slot_table_limit
124 	},
125 	{
126 		.procname	= "min_resvport",
127 		.data		= &xprt_min_resvport,
128 		.maxlen		= sizeof(unsigned int),
129 		.mode		= 0644,
130 		.proc_handler	= proc_dointvec_minmax,
131 		.extra1		= &xprt_min_resvport_limit,
132 		.extra2		= &xprt_max_resvport
133 	},
134 	{
135 		.procname	= "max_resvport",
136 		.data		= &xprt_max_resvport,
137 		.maxlen		= sizeof(unsigned int),
138 		.mode		= 0644,
139 		.proc_handler	= proc_dointvec_minmax,
140 		.extra1		= &xprt_min_resvport,
141 		.extra2		= &xprt_max_resvport_limit
142 	},
143 	{
144 		.procname	= "tcp_fin_timeout",
145 		.data		= &xs_tcp_fin_timeout,
146 		.maxlen		= sizeof(xs_tcp_fin_timeout),
147 		.mode		= 0644,
148 		.proc_handler	= proc_dointvec_jiffies,
149 	},
150 	{ },
151 };
152 
153 static struct ctl_table sunrpc_table[] = {
154 	{
155 		.procname	= "sunrpc",
156 		.mode		= 0555,
157 		.child		= xs_tunables_table
158 	},
159 	{ },
160 };
161 
162 #endif
163 
164 /*
165  * Wait duration for a reply from the RPC portmapper.
166  */
167 #define XS_BIND_TO		(60U * HZ)
168 
169 /*
170  * Delay if a UDP socket connect error occurs.  This is most likely some
171  * kind of resource problem on the local host.
172  */
173 #define XS_UDP_REEST_TO		(2U * HZ)
174 
175 /*
176  * The reestablish timeout allows clients to delay for a bit before attempting
177  * to reconnect to a server that just dropped our connection.
178  *
179  * We implement an exponential backoff when trying to reestablish a TCP
180  * transport connection with the server.  Some servers like to drop a TCP
181  * connection when they are overworked, so we start with a short timeout and
182  * increase over time if the server is down or not responding.
183  */
184 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
185 
186 /*
187  * TCP idle timeout; client drops the transport socket if it is idle
188  * for this long.  Note that we also timeout UDP sockets to prevent
189  * holding port numbers when there is no RPC traffic.
190  */
191 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
192 
193 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
194 # undef  RPC_DEBUG_DATA
195 # define RPCDBG_FACILITY	RPCDBG_TRANS
196 #endif
197 
198 #ifdef RPC_DEBUG_DATA
199 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
200 {
201 	u8 *buf = (u8 *) packet;
202 	int j;
203 
204 	dprintk("RPC:       %s\n", msg);
205 	for (j = 0; j < count && j < 128; j += 4) {
206 		if (!(j & 31)) {
207 			if (j)
208 				dprintk("\n");
209 			dprintk("0x%04x ", j);
210 		}
211 		dprintk("%02x%02x%02x%02x ",
212 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
213 	}
214 	dprintk("\n");
215 }
216 #else
217 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
218 {
219 	/* NOP */
220 }
221 #endif
222 
223 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
224 {
225 	return (struct rpc_xprt *) sk->sk_user_data;
226 }
227 
228 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
229 {
230 	return (struct sockaddr *) &xprt->addr;
231 }
232 
233 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
234 {
235 	return (struct sockaddr_un *) &xprt->addr;
236 }
237 
238 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
239 {
240 	return (struct sockaddr_in *) &xprt->addr;
241 }
242 
243 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
244 {
245 	return (struct sockaddr_in6 *) &xprt->addr;
246 }
247 
248 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
249 {
250 	struct sockaddr *sap = xs_addr(xprt);
251 	struct sockaddr_in6 *sin6;
252 	struct sockaddr_in *sin;
253 	struct sockaddr_un *sun;
254 	char buf[128];
255 
256 	switch (sap->sa_family) {
257 	case AF_LOCAL:
258 		sun = xs_addr_un(xprt);
259 		strlcpy(buf, sun->sun_path, sizeof(buf));
260 		xprt->address_strings[RPC_DISPLAY_ADDR] =
261 						kstrdup(buf, GFP_KERNEL);
262 		break;
263 	case AF_INET:
264 		(void)rpc_ntop(sap, buf, sizeof(buf));
265 		xprt->address_strings[RPC_DISPLAY_ADDR] =
266 						kstrdup(buf, GFP_KERNEL);
267 		sin = xs_addr_in(xprt);
268 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
269 		break;
270 	case AF_INET6:
271 		(void)rpc_ntop(sap, buf, sizeof(buf));
272 		xprt->address_strings[RPC_DISPLAY_ADDR] =
273 						kstrdup(buf, GFP_KERNEL);
274 		sin6 = xs_addr_in6(xprt);
275 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
276 		break;
277 	default:
278 		BUG();
279 	}
280 
281 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
282 }
283 
284 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
285 {
286 	struct sockaddr *sap = xs_addr(xprt);
287 	char buf[128];
288 
289 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
290 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
291 
292 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
293 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
294 }
295 
296 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
297 				     const char *protocol,
298 				     const char *netid)
299 {
300 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
301 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
302 	xs_format_common_peer_addresses(xprt);
303 	xs_format_common_peer_ports(xprt);
304 }
305 
306 static void xs_update_peer_port(struct rpc_xprt *xprt)
307 {
308 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
309 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
310 
311 	xs_format_common_peer_ports(xprt);
312 }
313 
314 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
315 {
316 	unsigned int i;
317 
318 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
319 		switch (i) {
320 		case RPC_DISPLAY_PROTO:
321 		case RPC_DISPLAY_NETID:
322 			continue;
323 		default:
324 			kfree(xprt->address_strings[i]);
325 		}
326 }
327 
328 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
329 
330 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
331 {
332 	struct msghdr msg = {
333 		.msg_name	= addr,
334 		.msg_namelen	= addrlen,
335 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
336 	};
337 	struct kvec iov = {
338 		.iov_base	= vec->iov_base + base,
339 		.iov_len	= vec->iov_len - base,
340 	};
341 
342 	if (iov.iov_len != 0)
343 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
344 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
345 }
346 
347 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
348 {
349 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
350 			int offset, size_t size, int flags);
351 	struct page **ppage;
352 	unsigned int remainder;
353 	int err;
354 
355 	remainder = xdr->page_len - base;
356 	base += xdr->page_base;
357 	ppage = xdr->pages + (base >> PAGE_SHIFT);
358 	base &= ~PAGE_MASK;
359 	do_sendpage = sock->ops->sendpage;
360 	if (!zerocopy)
361 		do_sendpage = sock_no_sendpage;
362 	for(;;) {
363 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
364 		int flags = XS_SENDMSG_FLAGS;
365 
366 		remainder -= len;
367 		if (more)
368 			flags |= MSG_MORE;
369 		if (remainder != 0)
370 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
371 		err = do_sendpage(sock, *ppage, base, len, flags);
372 		if (remainder == 0 || err != len)
373 			break;
374 		*sent_p += err;
375 		ppage++;
376 		base = 0;
377 	}
378 	if (err > 0) {
379 		*sent_p += err;
380 		err = 0;
381 	}
382 	return err;
383 }
384 
385 /**
386  * xs_sendpages - write pages directly to a socket
387  * @sock: socket to send on
388  * @addr: UDP only -- address of destination
389  * @addrlen: UDP only -- length of destination address
390  * @xdr: buffer containing this request
391  * @base: starting position in the buffer
392  * @zerocopy: true if it is safe to use sendpage()
393  * @sent_p: return the total number of bytes successfully queued for sending
394  *
395  */
396 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
397 {
398 	unsigned int remainder = xdr->len - base;
399 	int err = 0;
400 	int sent = 0;
401 
402 	if (unlikely(!sock))
403 		return -ENOTSOCK;
404 
405 	if (base != 0) {
406 		addr = NULL;
407 		addrlen = 0;
408 	}
409 
410 	if (base < xdr->head[0].iov_len || addr != NULL) {
411 		unsigned int len = xdr->head[0].iov_len - base;
412 		remainder -= len;
413 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
414 		if (remainder == 0 || err != len)
415 			goto out;
416 		*sent_p += err;
417 		base = 0;
418 	} else
419 		base -= xdr->head[0].iov_len;
420 
421 	if (base < xdr->page_len) {
422 		unsigned int len = xdr->page_len - base;
423 		remainder -= len;
424 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
425 		*sent_p += sent;
426 		if (remainder == 0 || sent != len)
427 			goto out;
428 		base = 0;
429 	} else
430 		base -= xdr->page_len;
431 
432 	if (base >= xdr->tail[0].iov_len)
433 		return 0;
434 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
435 out:
436 	if (err > 0) {
437 		*sent_p += err;
438 		err = 0;
439 	}
440 	return err;
441 }
442 
443 static void xs_nospace_callback(struct rpc_task *task)
444 {
445 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
446 
447 	transport->inet->sk_write_pending--;
448 }
449 
450 /**
451  * xs_nospace - place task on wait queue if transmit was incomplete
452  * @task: task to put to sleep
453  *
454  */
455 static int xs_nospace(struct rpc_task *task)
456 {
457 	struct rpc_rqst *req = task->tk_rqstp;
458 	struct rpc_xprt *xprt = req->rq_xprt;
459 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
460 	struct sock *sk = transport->inet;
461 	int ret = -EAGAIN;
462 
463 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
464 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
465 			req->rq_slen);
466 
467 	/* Protect against races with write_space */
468 	spin_lock_bh(&xprt->transport_lock);
469 
470 	/* Don't race with disconnect */
471 	if (xprt_connected(xprt)) {
472 		/* wait for more buffer space */
473 		sk->sk_write_pending++;
474 		xprt_wait_for_buffer_space(task, xs_nospace_callback);
475 	} else
476 		ret = -ENOTCONN;
477 
478 	spin_unlock_bh(&xprt->transport_lock);
479 
480 	/* Race breaker in case memory is freed before above code is called */
481 	if (ret == -EAGAIN) {
482 		struct socket_wq *wq;
483 
484 		rcu_read_lock();
485 		wq = rcu_dereference(sk->sk_wq);
486 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
487 		rcu_read_unlock();
488 
489 		sk->sk_write_space(sk);
490 	}
491 	return ret;
492 }
493 
494 /*
495  * Construct a stream transport record marker in @buf.
496  */
497 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
498 {
499 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
500 	rpc_fraghdr *base = buf->head[0].iov_base;
501 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
502 }
503 
504 /**
505  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
506  * @task: RPC task that manages the state of an RPC request
507  *
508  * Return values:
509  *        0:	The request has been sent
510  *   EAGAIN:	The socket was blocked, please call again later to
511  *		complete the request
512  * ENOTCONN:	Caller needs to invoke connect logic then call again
513  *    other:	Some other error occured, the request was not sent
514  */
515 static int xs_local_send_request(struct rpc_task *task)
516 {
517 	struct rpc_rqst *req = task->tk_rqstp;
518 	struct rpc_xprt *xprt = req->rq_xprt;
519 	struct sock_xprt *transport =
520 				container_of(xprt, struct sock_xprt, xprt);
521 	struct xdr_buf *xdr = &req->rq_snd_buf;
522 	int status;
523 	int sent = 0;
524 
525 	xs_encode_stream_record_marker(&req->rq_snd_buf);
526 
527 	xs_pktdump("packet data:",
528 			req->rq_svec->iov_base, req->rq_svec->iov_len);
529 
530 	status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
531 			      true, &sent);
532 	dprintk("RPC:       %s(%u) = %d\n",
533 			__func__, xdr->len - req->rq_bytes_sent, status);
534 
535 	if (status == -EAGAIN && sock_writeable(transport->inet))
536 		status = -ENOBUFS;
537 
538 	if (likely(sent > 0) || status == 0) {
539 		req->rq_bytes_sent += sent;
540 		req->rq_xmit_bytes_sent += sent;
541 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
542 			req->rq_bytes_sent = 0;
543 			return 0;
544 		}
545 		status = -EAGAIN;
546 	}
547 
548 	switch (status) {
549 	case -ENOBUFS:
550 		break;
551 	case -EAGAIN:
552 		status = xs_nospace(task);
553 		break;
554 	default:
555 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
556 			-status);
557 		/* fall through */
558 	case -EPIPE:
559 		xs_close(xprt);
560 		status = -ENOTCONN;
561 	}
562 
563 	return status;
564 }
565 
566 /**
567  * xs_udp_send_request - write an RPC request to a UDP socket
568  * @task: address of RPC task that manages the state of an RPC request
569  *
570  * Return values:
571  *        0:	The request has been sent
572  *   EAGAIN:	The socket was blocked, please call again later to
573  *		complete the request
574  * ENOTCONN:	Caller needs to invoke connect logic then call again
575  *    other:	Some other error occurred, the request was not sent
576  */
577 static int xs_udp_send_request(struct rpc_task *task)
578 {
579 	struct rpc_rqst *req = task->tk_rqstp;
580 	struct rpc_xprt *xprt = req->rq_xprt;
581 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
582 	struct xdr_buf *xdr = &req->rq_snd_buf;
583 	int sent = 0;
584 	int status;
585 
586 	xs_pktdump("packet data:",
587 				req->rq_svec->iov_base,
588 				req->rq_svec->iov_len);
589 
590 	if (!xprt_bound(xprt))
591 		return -ENOTCONN;
592 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
593 			      xdr, req->rq_bytes_sent, true, &sent);
594 
595 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
596 			xdr->len - req->rq_bytes_sent, status);
597 
598 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
599 	if (status == -EPERM)
600 		goto process_status;
601 
602 	if (status == -EAGAIN && sock_writeable(transport->inet))
603 		status = -ENOBUFS;
604 
605 	if (sent > 0 || status == 0) {
606 		req->rq_xmit_bytes_sent += sent;
607 		if (sent >= req->rq_slen)
608 			return 0;
609 		/* Still some bytes left; set up for a retry later. */
610 		status = -EAGAIN;
611 	}
612 
613 process_status:
614 	switch (status) {
615 	case -ENOTSOCK:
616 		status = -ENOTCONN;
617 		/* Should we call xs_close() here? */
618 		break;
619 	case -EAGAIN:
620 		status = xs_nospace(task);
621 		break;
622 	case -ENETUNREACH:
623 	case -ENOBUFS:
624 	case -EPIPE:
625 	case -ECONNREFUSED:
626 	case -EPERM:
627 		/* When the server has died, an ICMP port unreachable message
628 		 * prompts ECONNREFUSED. */
629 		break;
630 	default:
631 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
632 			-status);
633 	}
634 
635 	return status;
636 }
637 
638 /**
639  * xs_tcp_send_request - write an RPC request to a TCP socket
640  * @task: address of RPC task that manages the state of an RPC request
641  *
642  * Return values:
643  *        0:	The request has been sent
644  *   EAGAIN:	The socket was blocked, please call again later to
645  *		complete the request
646  * ENOTCONN:	Caller needs to invoke connect logic then call again
647  *    other:	Some other error occurred, the request was not sent
648  *
649  * XXX: In the case of soft timeouts, should we eventually give up
650  *	if sendmsg is not able to make progress?
651  */
652 static int xs_tcp_send_request(struct rpc_task *task)
653 {
654 	struct rpc_rqst *req = task->tk_rqstp;
655 	struct rpc_xprt *xprt = req->rq_xprt;
656 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
657 	struct xdr_buf *xdr = &req->rq_snd_buf;
658 	bool zerocopy = true;
659 	bool vm_wait = false;
660 	int status;
661 	int sent;
662 
663 	xs_encode_stream_record_marker(&req->rq_snd_buf);
664 
665 	xs_pktdump("packet data:",
666 				req->rq_svec->iov_base,
667 				req->rq_svec->iov_len);
668 	/* Don't use zero copy if this is a resend. If the RPC call
669 	 * completes while the socket holds a reference to the pages,
670 	 * then we may end up resending corrupted data.
671 	 */
672 	if (task->tk_flags & RPC_TASK_SENT)
673 		zerocopy = false;
674 
675 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
676 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
677 
678 	/* Continue transmitting the packet/record. We must be careful
679 	 * to cope with writespace callbacks arriving _after_ we have
680 	 * called sendmsg(). */
681 	while (1) {
682 		sent = 0;
683 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
684 				      req->rq_bytes_sent, zerocopy, &sent);
685 
686 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
687 				xdr->len - req->rq_bytes_sent, status);
688 
689 		/* If we've sent the entire packet, immediately
690 		 * reset the count of bytes sent. */
691 		req->rq_bytes_sent += sent;
692 		req->rq_xmit_bytes_sent += sent;
693 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
694 			req->rq_bytes_sent = 0;
695 			return 0;
696 		}
697 
698 		WARN_ON_ONCE(sent == 0 && status == 0);
699 
700 		if (status == -EAGAIN ) {
701 			/*
702 			 * Return EAGAIN if we're sure we're hitting the
703 			 * socket send buffer limits.
704 			 */
705 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
706 				break;
707 			/*
708 			 * Did we hit a memory allocation failure?
709 			 */
710 			if (sent == 0) {
711 				status = -ENOBUFS;
712 				if (vm_wait)
713 					break;
714 				/* Retry, knowing now that we're below the
715 				 * socket send buffer limit
716 				 */
717 				vm_wait = true;
718 			}
719 			continue;
720 		}
721 		if (status < 0)
722 			break;
723 		vm_wait = false;
724 	}
725 
726 	switch (status) {
727 	case -ENOTSOCK:
728 		status = -ENOTCONN;
729 		/* Should we call xs_close() here? */
730 		break;
731 	case -EAGAIN:
732 		status = xs_nospace(task);
733 		break;
734 	case -ECONNRESET:
735 	case -ECONNREFUSED:
736 	case -ENOTCONN:
737 	case -EADDRINUSE:
738 	case -ENOBUFS:
739 	case -EPIPE:
740 		break;
741 	default:
742 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
743 			-status);
744 	}
745 
746 	return status;
747 }
748 
749 /**
750  * xs_tcp_release_xprt - clean up after a tcp transmission
751  * @xprt: transport
752  * @task: rpc task
753  *
754  * This cleans up if an error causes us to abort the transmission of a request.
755  * In this case, the socket may need to be reset in order to avoid confusing
756  * the server.
757  */
758 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
759 {
760 	struct rpc_rqst *req;
761 
762 	if (task != xprt->snd_task)
763 		return;
764 	if (task == NULL)
765 		goto out_release;
766 	req = task->tk_rqstp;
767 	if (req == NULL)
768 		goto out_release;
769 	if (req->rq_bytes_sent == 0)
770 		goto out_release;
771 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
772 		goto out_release;
773 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
774 out_release:
775 	xprt_release_xprt(xprt, task);
776 }
777 
778 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
779 {
780 	transport->old_data_ready = sk->sk_data_ready;
781 	transport->old_state_change = sk->sk_state_change;
782 	transport->old_write_space = sk->sk_write_space;
783 	transport->old_error_report = sk->sk_error_report;
784 }
785 
786 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
787 {
788 	sk->sk_data_ready = transport->old_data_ready;
789 	sk->sk_state_change = transport->old_state_change;
790 	sk->sk_write_space = transport->old_write_space;
791 	sk->sk_error_report = transport->old_error_report;
792 }
793 
794 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
795 {
796 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
797 
798 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
799 }
800 
801 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
802 {
803 	smp_mb__before_atomic();
804 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
805 	clear_bit(XPRT_CLOSING, &xprt->state);
806 	xs_sock_reset_state_flags(xprt);
807 	smp_mb__after_atomic();
808 }
809 
810 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
811 {
812 	xs_sock_reset_connection_flags(xprt);
813 	/* Mark transport as closed and wake up all pending tasks */
814 	xprt_disconnect_done(xprt);
815 }
816 
817 /**
818  * xs_error_report - callback to handle TCP socket state errors
819  * @sk: socket
820  *
821  * Note: we don't call sock_error() since there may be a rpc_task
822  * using the socket, and so we don't want to clear sk->sk_err.
823  */
824 static void xs_error_report(struct sock *sk)
825 {
826 	struct rpc_xprt *xprt;
827 	int err;
828 
829 	read_lock_bh(&sk->sk_callback_lock);
830 	if (!(xprt = xprt_from_sock(sk)))
831 		goto out;
832 
833 	err = -sk->sk_err;
834 	if (err == 0)
835 		goto out;
836 	/* Is this a reset event? */
837 	if (sk->sk_state == TCP_CLOSE)
838 		xs_sock_mark_closed(xprt);
839 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
840 			xprt, -err);
841 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
842 	xprt_wake_pending_tasks(xprt, err);
843  out:
844 	read_unlock_bh(&sk->sk_callback_lock);
845 }
846 
847 static void xs_reset_transport(struct sock_xprt *transport)
848 {
849 	struct socket *sock = transport->sock;
850 	struct sock *sk = transport->inet;
851 	struct rpc_xprt *xprt = &transport->xprt;
852 
853 	if (sk == NULL)
854 		return;
855 
856 	if (atomic_read(&transport->xprt.swapper))
857 		sk_clear_memalloc(sk);
858 
859 	kernel_sock_shutdown(sock, SHUT_RDWR);
860 
861 	mutex_lock(&transport->recv_mutex);
862 	write_lock_bh(&sk->sk_callback_lock);
863 	transport->inet = NULL;
864 	transport->sock = NULL;
865 
866 	sk->sk_user_data = NULL;
867 
868 	xs_restore_old_callbacks(transport, sk);
869 	xprt_clear_connected(xprt);
870 	write_unlock_bh(&sk->sk_callback_lock);
871 	xs_sock_reset_connection_flags(xprt);
872 	mutex_unlock(&transport->recv_mutex);
873 
874 	trace_rpc_socket_close(xprt, sock);
875 	sock_release(sock);
876 }
877 
878 /**
879  * xs_close - close a socket
880  * @xprt: transport
881  *
882  * This is used when all requests are complete; ie, no DRC state remains
883  * on the server we want to save.
884  *
885  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
886  * xs_reset_transport() zeroing the socket from underneath a writer.
887  */
888 static void xs_close(struct rpc_xprt *xprt)
889 {
890 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
891 
892 	dprintk("RPC:       xs_close xprt %p\n", xprt);
893 
894 	xs_reset_transport(transport);
895 	xprt->reestablish_timeout = 0;
896 
897 	xprt_disconnect_done(xprt);
898 }
899 
900 static void xs_inject_disconnect(struct rpc_xprt *xprt)
901 {
902 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
903 		xprt);
904 	xprt_disconnect_done(xprt);
905 }
906 
907 static void xs_xprt_free(struct rpc_xprt *xprt)
908 {
909 	xs_free_peer_addresses(xprt);
910 	xprt_free(xprt);
911 }
912 
913 /**
914  * xs_destroy - prepare to shutdown a transport
915  * @xprt: doomed transport
916  *
917  */
918 static void xs_destroy(struct rpc_xprt *xprt)
919 {
920 	struct sock_xprt *transport = container_of(xprt,
921 			struct sock_xprt, xprt);
922 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
923 
924 	cancel_delayed_work_sync(&transport->connect_worker);
925 	xs_close(xprt);
926 	cancel_work_sync(&transport->recv_worker);
927 	xs_xprt_free(xprt);
928 	module_put(THIS_MODULE);
929 }
930 
931 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
932 {
933 	struct xdr_skb_reader desc = {
934 		.skb		= skb,
935 		.offset		= sizeof(rpc_fraghdr),
936 		.count		= skb->len - sizeof(rpc_fraghdr),
937 	};
938 
939 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
940 		return -1;
941 	if (desc.count)
942 		return -1;
943 	return 0;
944 }
945 
946 /**
947  * xs_local_data_read_skb
948  * @xprt: transport
949  * @sk: socket
950  * @skb: skbuff
951  *
952  * Currently this assumes we can read the whole reply in a single gulp.
953  */
954 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
955 		struct sock *sk,
956 		struct sk_buff *skb)
957 {
958 	struct rpc_task *task;
959 	struct rpc_rqst *rovr;
960 	int repsize, copied;
961 	u32 _xid;
962 	__be32 *xp;
963 
964 	repsize = skb->len - sizeof(rpc_fraghdr);
965 	if (repsize < 4) {
966 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
967 		return;
968 	}
969 
970 	/* Copy the XID from the skb... */
971 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
972 	if (xp == NULL)
973 		return;
974 
975 	/* Look up and lock the request corresponding to the given XID */
976 	spin_lock(&xprt->recv_lock);
977 	rovr = xprt_lookup_rqst(xprt, *xp);
978 	if (!rovr)
979 		goto out_unlock;
980 	xprt_pin_rqst(rovr);
981 	spin_unlock(&xprt->recv_lock);
982 	task = rovr->rq_task;
983 
984 	copied = rovr->rq_private_buf.buflen;
985 	if (copied > repsize)
986 		copied = repsize;
987 
988 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
989 		dprintk("RPC:       sk_buff copy failed\n");
990 		spin_lock(&xprt->recv_lock);
991 		goto out_unpin;
992 	}
993 
994 	spin_lock(&xprt->recv_lock);
995 	xprt_complete_rqst(task, copied);
996 out_unpin:
997 	xprt_unpin_rqst(rovr);
998  out_unlock:
999 	spin_unlock(&xprt->recv_lock);
1000 }
1001 
1002 static void xs_local_data_receive(struct sock_xprt *transport)
1003 {
1004 	struct sk_buff *skb;
1005 	struct sock *sk;
1006 	int err;
1007 
1008 restart:
1009 	mutex_lock(&transport->recv_mutex);
1010 	sk = transport->inet;
1011 	if (sk == NULL)
1012 		goto out;
1013 	for (;;) {
1014 		skb = skb_recv_datagram(sk, 0, 1, &err);
1015 		if (skb != NULL) {
1016 			xs_local_data_read_skb(&transport->xprt, sk, skb);
1017 			skb_free_datagram(sk, skb);
1018 			continue;
1019 		}
1020 		if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1021 			break;
1022 		if (need_resched()) {
1023 			mutex_unlock(&transport->recv_mutex);
1024 			cond_resched();
1025 			goto restart;
1026 		}
1027 	}
1028 out:
1029 	mutex_unlock(&transport->recv_mutex);
1030 }
1031 
1032 static void xs_local_data_receive_workfn(struct work_struct *work)
1033 {
1034 	struct sock_xprt *transport =
1035 		container_of(work, struct sock_xprt, recv_worker);
1036 	xs_local_data_receive(transport);
1037 }
1038 
1039 /**
1040  * xs_udp_data_read_skb - receive callback for UDP sockets
1041  * @xprt: transport
1042  * @sk: socket
1043  * @skb: skbuff
1044  *
1045  */
1046 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1047 		struct sock *sk,
1048 		struct sk_buff *skb)
1049 {
1050 	struct rpc_task *task;
1051 	struct rpc_rqst *rovr;
1052 	int repsize, copied;
1053 	u32 _xid;
1054 	__be32 *xp;
1055 
1056 	repsize = skb->len;
1057 	if (repsize < 4) {
1058 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1059 		return;
1060 	}
1061 
1062 	/* Copy the XID from the skb... */
1063 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1064 	if (xp == NULL)
1065 		return;
1066 
1067 	/* Look up and lock the request corresponding to the given XID */
1068 	spin_lock(&xprt->recv_lock);
1069 	rovr = xprt_lookup_rqst(xprt, *xp);
1070 	if (!rovr)
1071 		goto out_unlock;
1072 	xprt_pin_rqst(rovr);
1073 	spin_unlock(&xprt->recv_lock);
1074 	task = rovr->rq_task;
1075 
1076 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1077 		copied = repsize;
1078 
1079 	/* Suck it into the iovec, verify checksum if not done by hw. */
1080 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1081 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1082 		spin_lock(&xprt->recv_lock);
1083 		goto out_unpin;
1084 	}
1085 
1086 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1087 
1088 	spin_lock_bh(&xprt->transport_lock);
1089 	xprt_adjust_cwnd(xprt, task, copied);
1090 	spin_unlock_bh(&xprt->transport_lock);
1091 	spin_lock(&xprt->recv_lock);
1092 	xprt_complete_rqst(task, copied);
1093 out_unpin:
1094 	xprt_unpin_rqst(rovr);
1095  out_unlock:
1096 	spin_unlock(&xprt->recv_lock);
1097 }
1098 
1099 static void xs_udp_data_receive(struct sock_xprt *transport)
1100 {
1101 	struct sk_buff *skb;
1102 	struct sock *sk;
1103 	int err;
1104 
1105 restart:
1106 	mutex_lock(&transport->recv_mutex);
1107 	sk = transport->inet;
1108 	if (sk == NULL)
1109 		goto out;
1110 	for (;;) {
1111 		skb = skb_recv_udp(sk, 0, 1, &err);
1112 		if (skb != NULL) {
1113 			xs_udp_data_read_skb(&transport->xprt, sk, skb);
1114 			consume_skb(skb);
1115 			continue;
1116 		}
1117 		if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1118 			break;
1119 		if (need_resched()) {
1120 			mutex_unlock(&transport->recv_mutex);
1121 			cond_resched();
1122 			goto restart;
1123 		}
1124 	}
1125 out:
1126 	mutex_unlock(&transport->recv_mutex);
1127 }
1128 
1129 static void xs_udp_data_receive_workfn(struct work_struct *work)
1130 {
1131 	struct sock_xprt *transport =
1132 		container_of(work, struct sock_xprt, recv_worker);
1133 	xs_udp_data_receive(transport);
1134 }
1135 
1136 /**
1137  * xs_data_ready - "data ready" callback for UDP sockets
1138  * @sk: socket with data to read
1139  *
1140  */
1141 static void xs_data_ready(struct sock *sk)
1142 {
1143 	struct rpc_xprt *xprt;
1144 
1145 	read_lock_bh(&sk->sk_callback_lock);
1146 	dprintk("RPC:       xs_data_ready...\n");
1147 	xprt = xprt_from_sock(sk);
1148 	if (xprt != NULL) {
1149 		struct sock_xprt *transport = container_of(xprt,
1150 				struct sock_xprt, xprt);
1151 		transport->old_data_ready(sk);
1152 		/* Any data means we had a useful conversation, so
1153 		 * then we don't need to delay the next reconnect
1154 		 */
1155 		if (xprt->reestablish_timeout)
1156 			xprt->reestablish_timeout = 0;
1157 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1158 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1159 	}
1160 	read_unlock_bh(&sk->sk_callback_lock);
1161 }
1162 
1163 /*
1164  * Helper function to force a TCP close if the server is sending
1165  * junk and/or it has put us in CLOSE_WAIT
1166  */
1167 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1168 {
1169 	xprt_force_disconnect(xprt);
1170 }
1171 
1172 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1173 {
1174 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1175 	size_t len, used;
1176 	char *p;
1177 
1178 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1179 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1180 	used = xdr_skb_read_bits(desc, p, len);
1181 	transport->tcp_offset += used;
1182 	if (used != len)
1183 		return;
1184 
1185 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1186 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1187 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1188 	else
1189 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1190 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1191 
1192 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1193 	transport->tcp_offset = 0;
1194 
1195 	/* Sanity check of the record length */
1196 	if (unlikely(transport->tcp_reclen < 8)) {
1197 		dprintk("RPC:       invalid TCP record fragment length\n");
1198 		xs_tcp_force_close(xprt);
1199 		return;
1200 	}
1201 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1202 			transport->tcp_reclen);
1203 }
1204 
1205 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1206 {
1207 	if (transport->tcp_offset == transport->tcp_reclen) {
1208 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1209 		transport->tcp_offset = 0;
1210 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1211 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1212 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1213 			transport->tcp_copied = 0;
1214 		}
1215 	}
1216 }
1217 
1218 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1219 {
1220 	size_t len, used;
1221 	char *p;
1222 
1223 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1224 	dprintk("RPC:       reading XID (%zu bytes)\n", len);
1225 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1226 	used = xdr_skb_read_bits(desc, p, len);
1227 	transport->tcp_offset += used;
1228 	if (used != len)
1229 		return;
1230 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1231 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1232 	transport->tcp_copied = 4;
1233 	dprintk("RPC:       reading %s XID %08x\n",
1234 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1235 							      : "request with",
1236 			ntohl(transport->tcp_xid));
1237 	xs_tcp_check_fraghdr(transport);
1238 }
1239 
1240 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1241 				       struct xdr_skb_reader *desc)
1242 {
1243 	size_t len, used;
1244 	u32 offset;
1245 	char *p;
1246 
1247 	/*
1248 	 * We want transport->tcp_offset to be 8 at the end of this routine
1249 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1250 	 * When this function is called for the first time,
1251 	 * transport->tcp_offset is 4 (after having already read the xid).
1252 	 */
1253 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1254 	len = sizeof(transport->tcp_calldir) - offset;
1255 	dprintk("RPC:       reading CALL/REPLY flag (%zu bytes)\n", len);
1256 	p = ((char *) &transport->tcp_calldir) + offset;
1257 	used = xdr_skb_read_bits(desc, p, len);
1258 	transport->tcp_offset += used;
1259 	if (used != len)
1260 		return;
1261 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1262 	/*
1263 	 * We don't yet have the XDR buffer, so we will write the calldir
1264 	 * out after we get the buffer from the 'struct rpc_rqst'
1265 	 */
1266 	switch (ntohl(transport->tcp_calldir)) {
1267 	case RPC_REPLY:
1268 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1269 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1270 		transport->tcp_flags |= TCP_RPC_REPLY;
1271 		break;
1272 	case RPC_CALL:
1273 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1274 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1275 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1276 		break;
1277 	default:
1278 		dprintk("RPC:       invalid request message type\n");
1279 		xs_tcp_force_close(&transport->xprt);
1280 	}
1281 	xs_tcp_check_fraghdr(transport);
1282 }
1283 
1284 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1285 				     struct xdr_skb_reader *desc,
1286 				     struct rpc_rqst *req)
1287 {
1288 	struct sock_xprt *transport =
1289 				container_of(xprt, struct sock_xprt, xprt);
1290 	struct xdr_buf *rcvbuf;
1291 	size_t len;
1292 	ssize_t r;
1293 
1294 	rcvbuf = &req->rq_private_buf;
1295 
1296 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1297 		/*
1298 		 * Save the RPC direction in the XDR buffer
1299 		 */
1300 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1301 			&transport->tcp_calldir,
1302 			sizeof(transport->tcp_calldir));
1303 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1304 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1305 	}
1306 
1307 	len = desc->count;
1308 	if (len > transport->tcp_reclen - transport->tcp_offset)
1309 		desc->count = transport->tcp_reclen - transport->tcp_offset;
1310 	r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1311 					  desc, xdr_skb_read_bits);
1312 
1313 	if (desc->count) {
1314 		/* Error when copying to the receive buffer,
1315 		 * usually because we weren't able to allocate
1316 		 * additional buffer pages. All we can do now
1317 		 * is turn off TCP_RCV_COPY_DATA, so the request
1318 		 * will not receive any additional updates,
1319 		 * and time out.
1320 		 * Any remaining data from this record will
1321 		 * be discarded.
1322 		 */
1323 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1324 		dprintk("RPC:       XID %08x truncated request\n",
1325 				ntohl(transport->tcp_xid));
1326 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1327 				"tcp_offset = %u, tcp_reclen = %u\n",
1328 				xprt, transport->tcp_copied,
1329 				transport->tcp_offset, transport->tcp_reclen);
1330 		return;
1331 	}
1332 
1333 	transport->tcp_copied += r;
1334 	transport->tcp_offset += r;
1335 	desc->count = len - r;
1336 
1337 	dprintk("RPC:       XID %08x read %zd bytes\n",
1338 			ntohl(transport->tcp_xid), r);
1339 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1340 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1341 			transport->tcp_offset, transport->tcp_reclen);
1342 
1343 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1344 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1345 	else if (transport->tcp_offset == transport->tcp_reclen) {
1346 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1347 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1348 	}
1349 }
1350 
1351 /*
1352  * Finds the request corresponding to the RPC xid and invokes the common
1353  * tcp read code to read the data.
1354  */
1355 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1356 				    struct xdr_skb_reader *desc)
1357 {
1358 	struct sock_xprt *transport =
1359 				container_of(xprt, struct sock_xprt, xprt);
1360 	struct rpc_rqst *req;
1361 
1362 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1363 
1364 	/* Find and lock the request corresponding to this xid */
1365 	spin_lock(&xprt->recv_lock);
1366 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1367 	if (!req) {
1368 		dprintk("RPC:       XID %08x request not found!\n",
1369 				ntohl(transport->tcp_xid));
1370 		spin_unlock(&xprt->recv_lock);
1371 		return -1;
1372 	}
1373 	xprt_pin_rqst(req);
1374 	spin_unlock(&xprt->recv_lock);
1375 
1376 	xs_tcp_read_common(xprt, desc, req);
1377 
1378 	spin_lock(&xprt->recv_lock);
1379 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1380 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1381 	xprt_unpin_rqst(req);
1382 	spin_unlock(&xprt->recv_lock);
1383 	return 0;
1384 }
1385 
1386 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1387 /*
1388  * Obtains an rpc_rqst previously allocated and invokes the common
1389  * tcp read code to read the data.  The result is placed in the callback
1390  * queue.
1391  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1392  * connection and return -1.
1393  */
1394 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1395 				       struct xdr_skb_reader *desc)
1396 {
1397 	struct sock_xprt *transport =
1398 				container_of(xprt, struct sock_xprt, xprt);
1399 	struct rpc_rqst *req;
1400 
1401 	/* Look up the request corresponding to the given XID */
1402 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1403 	if (req == NULL) {
1404 		printk(KERN_WARNING "Callback slot table overflowed\n");
1405 		xprt_force_disconnect(xprt);
1406 		return -1;
1407 	}
1408 
1409 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1410 	xs_tcp_read_common(xprt, desc, req);
1411 
1412 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1413 		xprt_complete_bc_request(req, transport->tcp_copied);
1414 
1415 	return 0;
1416 }
1417 
1418 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1419 					struct xdr_skb_reader *desc)
1420 {
1421 	struct sock_xprt *transport =
1422 				container_of(xprt, struct sock_xprt, xprt);
1423 
1424 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1425 		xs_tcp_read_reply(xprt, desc) :
1426 		xs_tcp_read_callback(xprt, desc);
1427 }
1428 
1429 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1430 {
1431 	int ret;
1432 
1433 	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1434 			      SVC_SOCK_ANONYMOUS);
1435 	if (ret < 0)
1436 		return ret;
1437 	return 0;
1438 }
1439 
1440 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1441 {
1442 	return PAGE_SIZE;
1443 }
1444 #else
1445 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1446 					struct xdr_skb_reader *desc)
1447 {
1448 	return xs_tcp_read_reply(xprt, desc);
1449 }
1450 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1451 
1452 /*
1453  * Read data off the transport.  This can be either an RPC_CALL or an
1454  * RPC_REPLY.  Relay the processing to helper functions.
1455  */
1456 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1457 				    struct xdr_skb_reader *desc)
1458 {
1459 	struct sock_xprt *transport =
1460 				container_of(xprt, struct sock_xprt, xprt);
1461 
1462 	if (_xs_tcp_read_data(xprt, desc) == 0)
1463 		xs_tcp_check_fraghdr(transport);
1464 	else {
1465 		/*
1466 		 * The transport_lock protects the request handling.
1467 		 * There's no need to hold it to update the tcp_flags.
1468 		 */
1469 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1470 	}
1471 }
1472 
1473 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1474 {
1475 	size_t len;
1476 
1477 	len = transport->tcp_reclen - transport->tcp_offset;
1478 	if (len > desc->count)
1479 		len = desc->count;
1480 	desc->count -= len;
1481 	desc->offset += len;
1482 	transport->tcp_offset += len;
1483 	dprintk("RPC:       discarded %zu bytes\n", len);
1484 	xs_tcp_check_fraghdr(transport);
1485 }
1486 
1487 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1488 {
1489 	struct rpc_xprt *xprt = rd_desc->arg.data;
1490 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1491 	struct xdr_skb_reader desc = {
1492 		.skb	= skb,
1493 		.offset	= offset,
1494 		.count	= len,
1495 	};
1496 	size_t ret;
1497 
1498 	dprintk("RPC:       xs_tcp_data_recv started\n");
1499 	do {
1500 		trace_xs_tcp_data_recv(transport);
1501 		/* Read in a new fragment marker if necessary */
1502 		/* Can we ever really expect to get completely empty fragments? */
1503 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1504 			xs_tcp_read_fraghdr(xprt, &desc);
1505 			continue;
1506 		}
1507 		/* Read in the xid if necessary */
1508 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1509 			xs_tcp_read_xid(transport, &desc);
1510 			continue;
1511 		}
1512 		/* Read in the call/reply flag */
1513 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1514 			xs_tcp_read_calldir(transport, &desc);
1515 			continue;
1516 		}
1517 		/* Read in the request data */
1518 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1519 			xs_tcp_read_data(xprt, &desc);
1520 			continue;
1521 		}
1522 		/* Skip over any trailing bytes on short reads */
1523 		xs_tcp_read_discard(transport, &desc);
1524 	} while (desc.count);
1525 	ret = len - desc.count;
1526 	if (ret < rd_desc->count)
1527 		rd_desc->count -= ret;
1528 	else
1529 		rd_desc->count = 0;
1530 	trace_xs_tcp_data_recv(transport);
1531 	dprintk("RPC:       xs_tcp_data_recv done\n");
1532 	return ret;
1533 }
1534 
1535 static void xs_tcp_data_receive(struct sock_xprt *transport)
1536 {
1537 	struct rpc_xprt *xprt = &transport->xprt;
1538 	struct sock *sk;
1539 	read_descriptor_t rd_desc = {
1540 		.arg.data = xprt,
1541 	};
1542 	unsigned long total = 0;
1543 	int read = 0;
1544 
1545 restart:
1546 	mutex_lock(&transport->recv_mutex);
1547 	sk = transport->inet;
1548 	if (sk == NULL)
1549 		goto out;
1550 
1551 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1552 	for (;;) {
1553 		rd_desc.count = RPC_TCP_READ_CHUNK_SZ;
1554 		lock_sock(sk);
1555 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1556 		if (rd_desc.count != 0 || read < 0) {
1557 			clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1558 			release_sock(sk);
1559 			break;
1560 		}
1561 		release_sock(sk);
1562 		total += read;
1563 		if (need_resched()) {
1564 			mutex_unlock(&transport->recv_mutex);
1565 			cond_resched();
1566 			goto restart;
1567 		}
1568 	}
1569 	if (test_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1570 		queue_work(xprtiod_workqueue, &transport->recv_worker);
1571 out:
1572 	mutex_unlock(&transport->recv_mutex);
1573 	trace_xs_tcp_data_ready(xprt, read, total);
1574 }
1575 
1576 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1577 {
1578 	struct sock_xprt *transport =
1579 		container_of(work, struct sock_xprt, recv_worker);
1580 	xs_tcp_data_receive(transport);
1581 }
1582 
1583 /**
1584  * xs_tcp_state_change - callback to handle TCP socket state changes
1585  * @sk: socket whose state has changed
1586  *
1587  */
1588 static void xs_tcp_state_change(struct sock *sk)
1589 {
1590 	struct rpc_xprt *xprt;
1591 	struct sock_xprt *transport;
1592 
1593 	read_lock_bh(&sk->sk_callback_lock);
1594 	if (!(xprt = xprt_from_sock(sk)))
1595 		goto out;
1596 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1597 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1598 			sk->sk_state, xprt_connected(xprt),
1599 			sock_flag(sk, SOCK_DEAD),
1600 			sock_flag(sk, SOCK_ZAPPED),
1601 			sk->sk_shutdown);
1602 
1603 	transport = container_of(xprt, struct sock_xprt, xprt);
1604 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1605 	switch (sk->sk_state) {
1606 	case TCP_ESTABLISHED:
1607 		spin_lock(&xprt->transport_lock);
1608 		if (!xprt_test_and_set_connected(xprt)) {
1609 
1610 			/* Reset TCP record info */
1611 			transport->tcp_offset = 0;
1612 			transport->tcp_reclen = 0;
1613 			transport->tcp_copied = 0;
1614 			transport->tcp_flags =
1615 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1616 			xprt->connect_cookie++;
1617 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1618 			xprt_clear_connecting(xprt);
1619 
1620 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1621 		}
1622 		spin_unlock(&xprt->transport_lock);
1623 		break;
1624 	case TCP_FIN_WAIT1:
1625 		/* The client initiated a shutdown of the socket */
1626 		xprt->connect_cookie++;
1627 		xprt->reestablish_timeout = 0;
1628 		set_bit(XPRT_CLOSING, &xprt->state);
1629 		smp_mb__before_atomic();
1630 		clear_bit(XPRT_CONNECTED, &xprt->state);
1631 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1632 		smp_mb__after_atomic();
1633 		break;
1634 	case TCP_CLOSE_WAIT:
1635 		/* The server initiated a shutdown of the socket */
1636 		xprt->connect_cookie++;
1637 		clear_bit(XPRT_CONNECTED, &xprt->state);
1638 		xs_tcp_force_close(xprt);
1639 		/* fall through */
1640 	case TCP_CLOSING:
1641 		/*
1642 		 * If the server closed down the connection, make sure that
1643 		 * we back off before reconnecting
1644 		 */
1645 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1646 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1647 		break;
1648 	case TCP_LAST_ACK:
1649 		set_bit(XPRT_CLOSING, &xprt->state);
1650 		smp_mb__before_atomic();
1651 		clear_bit(XPRT_CONNECTED, &xprt->state);
1652 		smp_mb__after_atomic();
1653 		break;
1654 	case TCP_CLOSE:
1655 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1656 					&transport->sock_state))
1657 			xprt_clear_connecting(xprt);
1658 		if (sk->sk_err)
1659 			xprt_wake_pending_tasks(xprt, -sk->sk_err);
1660 		xs_sock_mark_closed(xprt);
1661 	}
1662  out:
1663 	read_unlock_bh(&sk->sk_callback_lock);
1664 }
1665 
1666 static void xs_write_space(struct sock *sk)
1667 {
1668 	struct socket_wq *wq;
1669 	struct rpc_xprt *xprt;
1670 
1671 	if (!sk->sk_socket)
1672 		return;
1673 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1674 
1675 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1676 		return;
1677 	rcu_read_lock();
1678 	wq = rcu_dereference(sk->sk_wq);
1679 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1680 		goto out;
1681 
1682 	xprt_write_space(xprt);
1683 out:
1684 	rcu_read_unlock();
1685 }
1686 
1687 /**
1688  * xs_udp_write_space - callback invoked when socket buffer space
1689  *                             becomes available
1690  * @sk: socket whose state has changed
1691  *
1692  * Called when more output buffer space is available for this socket.
1693  * We try not to wake our writers until they can make "significant"
1694  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1695  * with a bunch of small requests.
1696  */
1697 static void xs_udp_write_space(struct sock *sk)
1698 {
1699 	read_lock_bh(&sk->sk_callback_lock);
1700 
1701 	/* from net/core/sock.c:sock_def_write_space */
1702 	if (sock_writeable(sk))
1703 		xs_write_space(sk);
1704 
1705 	read_unlock_bh(&sk->sk_callback_lock);
1706 }
1707 
1708 /**
1709  * xs_tcp_write_space - callback invoked when socket buffer space
1710  *                             becomes available
1711  * @sk: socket whose state has changed
1712  *
1713  * Called when more output buffer space is available for this socket.
1714  * We try not to wake our writers until they can make "significant"
1715  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1716  * with a bunch of small requests.
1717  */
1718 static void xs_tcp_write_space(struct sock *sk)
1719 {
1720 	read_lock_bh(&sk->sk_callback_lock);
1721 
1722 	/* from net/core/stream.c:sk_stream_write_space */
1723 	if (sk_stream_is_writeable(sk))
1724 		xs_write_space(sk);
1725 
1726 	read_unlock_bh(&sk->sk_callback_lock);
1727 }
1728 
1729 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1730 {
1731 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1732 	struct sock *sk = transport->inet;
1733 
1734 	if (transport->rcvsize) {
1735 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1736 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1737 	}
1738 	if (transport->sndsize) {
1739 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1740 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1741 		sk->sk_write_space(sk);
1742 	}
1743 }
1744 
1745 /**
1746  * xs_udp_set_buffer_size - set send and receive limits
1747  * @xprt: generic transport
1748  * @sndsize: requested size of send buffer, in bytes
1749  * @rcvsize: requested size of receive buffer, in bytes
1750  *
1751  * Set socket send and receive buffer size limits.
1752  */
1753 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1754 {
1755 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1756 
1757 	transport->sndsize = 0;
1758 	if (sndsize)
1759 		transport->sndsize = sndsize + 1024;
1760 	transport->rcvsize = 0;
1761 	if (rcvsize)
1762 		transport->rcvsize = rcvsize + 1024;
1763 
1764 	xs_udp_do_set_buffer_size(xprt);
1765 }
1766 
1767 /**
1768  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1769  * @task: task that timed out
1770  *
1771  * Adjust the congestion window after a retransmit timeout has occurred.
1772  */
1773 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1774 {
1775 	spin_lock_bh(&xprt->transport_lock);
1776 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1777 	spin_unlock_bh(&xprt->transport_lock);
1778 }
1779 
1780 static unsigned short xs_get_random_port(void)
1781 {
1782 	unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
1783 	unsigned short rand = (unsigned short) prandom_u32() % range;
1784 	return rand + xprt_min_resvport;
1785 }
1786 
1787 /**
1788  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1789  * @sock: socket
1790  *
1791  * Note that this function has to be called on all sockets that share the
1792  * same port, and it must be called before binding.
1793  */
1794 static void xs_sock_set_reuseport(struct socket *sock)
1795 {
1796 	int opt = 1;
1797 
1798 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1799 			(char *)&opt, sizeof(opt));
1800 }
1801 
1802 static unsigned short xs_sock_getport(struct socket *sock)
1803 {
1804 	struct sockaddr_storage buf;
1805 	int buflen;
1806 	unsigned short port = 0;
1807 
1808 	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1809 		goto out;
1810 	switch (buf.ss_family) {
1811 	case AF_INET6:
1812 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1813 		break;
1814 	case AF_INET:
1815 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1816 	}
1817 out:
1818 	return port;
1819 }
1820 
1821 /**
1822  * xs_set_port - reset the port number in the remote endpoint address
1823  * @xprt: generic transport
1824  * @port: new port number
1825  *
1826  */
1827 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1828 {
1829 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1830 
1831 	rpc_set_port(xs_addr(xprt), port);
1832 	xs_update_peer_port(xprt);
1833 }
1834 
1835 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1836 {
1837 	if (transport->srcport == 0)
1838 		transport->srcport = xs_sock_getport(sock);
1839 }
1840 
1841 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1842 {
1843 	unsigned short port = transport->srcport;
1844 
1845 	if (port == 0 && transport->xprt.resvport)
1846 		port = xs_get_random_port();
1847 	return port;
1848 }
1849 
1850 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1851 {
1852 	if (transport->srcport != 0)
1853 		transport->srcport = 0;
1854 	if (!transport->xprt.resvport)
1855 		return 0;
1856 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1857 		return xprt_max_resvport;
1858 	return --port;
1859 }
1860 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1861 {
1862 	struct sockaddr_storage myaddr;
1863 	int err, nloop = 0;
1864 	unsigned short port = xs_get_srcport(transport);
1865 	unsigned short last;
1866 
1867 	/*
1868 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1869 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1870 	 * port selection happen implicitly when the socket is used
1871 	 * (for example at connect time).
1872 	 *
1873 	 * This ensures that we can continue to establish TCP
1874 	 * connections even when all local ephemeral ports are already
1875 	 * a part of some TCP connection.  This makes no difference
1876 	 * for UDP sockets, but also doens't harm them.
1877 	 *
1878 	 * If we're asking for any reserved port (i.e. port == 0 &&
1879 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1880 	 * ensure that port is non-zero and we will bind as needed.
1881 	 */
1882 	if (port == 0)
1883 		return 0;
1884 
1885 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1886 	do {
1887 		rpc_set_port((struct sockaddr *)&myaddr, port);
1888 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1889 				transport->xprt.addrlen);
1890 		if (err == 0) {
1891 			transport->srcport = port;
1892 			break;
1893 		}
1894 		last = port;
1895 		port = xs_next_srcport(transport, port);
1896 		if (port > last)
1897 			nloop++;
1898 	} while (err == -EADDRINUSE && nloop != 2);
1899 
1900 	if (myaddr.ss_family == AF_INET)
1901 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1902 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1903 				port, err ? "failed" : "ok", err);
1904 	else
1905 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1906 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1907 				port, err ? "failed" : "ok", err);
1908 	return err;
1909 }
1910 
1911 /*
1912  * We don't support autobind on AF_LOCAL sockets
1913  */
1914 static void xs_local_rpcbind(struct rpc_task *task)
1915 {
1916 	xprt_set_bound(task->tk_xprt);
1917 }
1918 
1919 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1920 {
1921 }
1922 
1923 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1924 static struct lock_class_key xs_key[2];
1925 static struct lock_class_key xs_slock_key[2];
1926 
1927 static inline void xs_reclassify_socketu(struct socket *sock)
1928 {
1929 	struct sock *sk = sock->sk;
1930 
1931 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1932 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1933 }
1934 
1935 static inline void xs_reclassify_socket4(struct socket *sock)
1936 {
1937 	struct sock *sk = sock->sk;
1938 
1939 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1940 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1941 }
1942 
1943 static inline void xs_reclassify_socket6(struct socket *sock)
1944 {
1945 	struct sock *sk = sock->sk;
1946 
1947 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1948 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1949 }
1950 
1951 static inline void xs_reclassify_socket(int family, struct socket *sock)
1952 {
1953 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1954 		return;
1955 
1956 	switch (family) {
1957 	case AF_LOCAL:
1958 		xs_reclassify_socketu(sock);
1959 		break;
1960 	case AF_INET:
1961 		xs_reclassify_socket4(sock);
1962 		break;
1963 	case AF_INET6:
1964 		xs_reclassify_socket6(sock);
1965 		break;
1966 	}
1967 }
1968 #else
1969 static inline void xs_reclassify_socket(int family, struct socket *sock)
1970 {
1971 }
1972 #endif
1973 
1974 static void xs_dummy_setup_socket(struct work_struct *work)
1975 {
1976 }
1977 
1978 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1979 		struct sock_xprt *transport, int family, int type,
1980 		int protocol, bool reuseport)
1981 {
1982 	struct socket *sock;
1983 	int err;
1984 
1985 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1986 	if (err < 0) {
1987 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1988 				protocol, -err);
1989 		goto out;
1990 	}
1991 	xs_reclassify_socket(family, sock);
1992 
1993 	if (reuseport)
1994 		xs_sock_set_reuseport(sock);
1995 
1996 	err = xs_bind(transport, sock);
1997 	if (err) {
1998 		sock_release(sock);
1999 		goto out;
2000 	}
2001 
2002 	return sock;
2003 out:
2004 	return ERR_PTR(err);
2005 }
2006 
2007 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
2008 				      struct socket *sock)
2009 {
2010 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2011 									xprt);
2012 
2013 	if (!transport->inet) {
2014 		struct sock *sk = sock->sk;
2015 
2016 		write_lock_bh(&sk->sk_callback_lock);
2017 
2018 		xs_save_old_callbacks(transport, sk);
2019 
2020 		sk->sk_user_data = xprt;
2021 		sk->sk_data_ready = xs_data_ready;
2022 		sk->sk_write_space = xs_udp_write_space;
2023 		sock_set_flag(sk, SOCK_FASYNC);
2024 		sk->sk_error_report = xs_error_report;
2025 		sk->sk_allocation = GFP_NOIO;
2026 
2027 		xprt_clear_connected(xprt);
2028 
2029 		/* Reset to new socket */
2030 		transport->sock = sock;
2031 		transport->inet = sk;
2032 
2033 		write_unlock_bh(&sk->sk_callback_lock);
2034 	}
2035 
2036 	/* Tell the socket layer to start connecting... */
2037 	xprt->stat.connect_count++;
2038 	xprt->stat.connect_start = jiffies;
2039 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
2040 }
2041 
2042 /**
2043  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
2044  * @transport: socket transport to connect
2045  */
2046 static int xs_local_setup_socket(struct sock_xprt *transport)
2047 {
2048 	struct rpc_xprt *xprt = &transport->xprt;
2049 	struct socket *sock;
2050 	int status = -EIO;
2051 
2052 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
2053 					SOCK_STREAM, 0, &sock, 1);
2054 	if (status < 0) {
2055 		dprintk("RPC:       can't create AF_LOCAL "
2056 			"transport socket (%d).\n", -status);
2057 		goto out;
2058 	}
2059 	xs_reclassify_socket(AF_LOCAL, sock);
2060 
2061 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
2062 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2063 
2064 	status = xs_local_finish_connecting(xprt, sock);
2065 	trace_rpc_socket_connect(xprt, sock, status);
2066 	switch (status) {
2067 	case 0:
2068 		dprintk("RPC:       xprt %p connected to %s\n",
2069 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2070 		xprt_set_connected(xprt);
2071 	case -ENOBUFS:
2072 		break;
2073 	case -ENOENT:
2074 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
2075 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2076 		break;
2077 	case -ECONNREFUSED:
2078 		dprintk("RPC:       xprt %p: connection refused for %s\n",
2079 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2080 		break;
2081 	default:
2082 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2083 				__func__, -status,
2084 				xprt->address_strings[RPC_DISPLAY_ADDR]);
2085 	}
2086 
2087 out:
2088 	xprt_clear_connecting(xprt);
2089 	xprt_wake_pending_tasks(xprt, status);
2090 	return status;
2091 }
2092 
2093 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2094 {
2095 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2096 	int ret;
2097 
2098 	 if (RPC_IS_ASYNC(task)) {
2099 		/*
2100 		 * We want the AF_LOCAL connect to be resolved in the
2101 		 * filesystem namespace of the process making the rpc
2102 		 * call.  Thus we connect synchronously.
2103 		 *
2104 		 * If we want to support asynchronous AF_LOCAL calls,
2105 		 * we'll need to figure out how to pass a namespace to
2106 		 * connect.
2107 		 */
2108 		rpc_exit(task, -ENOTCONN);
2109 		return;
2110 	}
2111 	ret = xs_local_setup_socket(transport);
2112 	if (ret && !RPC_IS_SOFTCONN(task))
2113 		msleep_interruptible(15000);
2114 }
2115 
2116 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2117 /*
2118  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2119  * know that we have exclusive access to the socket), to guard against
2120  * races with xs_reset_transport.
2121  */
2122 static void xs_set_memalloc(struct rpc_xprt *xprt)
2123 {
2124 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2125 			xprt);
2126 
2127 	/*
2128 	 * If there's no sock, then we have nothing to set. The
2129 	 * reconnecting process will get it for us.
2130 	 */
2131 	if (!transport->inet)
2132 		return;
2133 	if (atomic_read(&xprt->swapper))
2134 		sk_set_memalloc(transport->inet);
2135 }
2136 
2137 /**
2138  * xs_enable_swap - Tag this transport as being used for swap.
2139  * @xprt: transport to tag
2140  *
2141  * Take a reference to this transport on behalf of the rpc_clnt, and
2142  * optionally mark it for swapping if it wasn't already.
2143  */
2144 static int
2145 xs_enable_swap(struct rpc_xprt *xprt)
2146 {
2147 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2148 
2149 	if (atomic_inc_return(&xprt->swapper) != 1)
2150 		return 0;
2151 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2152 		return -ERESTARTSYS;
2153 	if (xs->inet)
2154 		sk_set_memalloc(xs->inet);
2155 	xprt_release_xprt(xprt, NULL);
2156 	return 0;
2157 }
2158 
2159 /**
2160  * xs_disable_swap - Untag this transport as being used for swap.
2161  * @xprt: transport to tag
2162  *
2163  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2164  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2165  */
2166 static void
2167 xs_disable_swap(struct rpc_xprt *xprt)
2168 {
2169 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2170 
2171 	if (!atomic_dec_and_test(&xprt->swapper))
2172 		return;
2173 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2174 		return;
2175 	if (xs->inet)
2176 		sk_clear_memalloc(xs->inet);
2177 	xprt_release_xprt(xprt, NULL);
2178 }
2179 #else
2180 static void xs_set_memalloc(struct rpc_xprt *xprt)
2181 {
2182 }
2183 
2184 static int
2185 xs_enable_swap(struct rpc_xprt *xprt)
2186 {
2187 	return -EINVAL;
2188 }
2189 
2190 static void
2191 xs_disable_swap(struct rpc_xprt *xprt)
2192 {
2193 }
2194 #endif
2195 
2196 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2197 {
2198 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2199 
2200 	if (!transport->inet) {
2201 		struct sock *sk = sock->sk;
2202 
2203 		write_lock_bh(&sk->sk_callback_lock);
2204 
2205 		xs_save_old_callbacks(transport, sk);
2206 
2207 		sk->sk_user_data = xprt;
2208 		sk->sk_data_ready = xs_data_ready;
2209 		sk->sk_write_space = xs_udp_write_space;
2210 		sock_set_flag(sk, SOCK_FASYNC);
2211 		sk->sk_allocation = GFP_NOIO;
2212 
2213 		xprt_set_connected(xprt);
2214 
2215 		/* Reset to new socket */
2216 		transport->sock = sock;
2217 		transport->inet = sk;
2218 
2219 		xs_set_memalloc(xprt);
2220 
2221 		write_unlock_bh(&sk->sk_callback_lock);
2222 	}
2223 	xs_udp_do_set_buffer_size(xprt);
2224 
2225 	xprt->stat.connect_start = jiffies;
2226 }
2227 
2228 static void xs_udp_setup_socket(struct work_struct *work)
2229 {
2230 	struct sock_xprt *transport =
2231 		container_of(work, struct sock_xprt, connect_worker.work);
2232 	struct rpc_xprt *xprt = &transport->xprt;
2233 	struct socket *sock;
2234 	int status = -EIO;
2235 
2236 	sock = xs_create_sock(xprt, transport,
2237 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2238 			IPPROTO_UDP, false);
2239 	if (IS_ERR(sock))
2240 		goto out;
2241 
2242 	dprintk("RPC:       worker connecting xprt %p via %s to "
2243 				"%s (port %s)\n", xprt,
2244 			xprt->address_strings[RPC_DISPLAY_PROTO],
2245 			xprt->address_strings[RPC_DISPLAY_ADDR],
2246 			xprt->address_strings[RPC_DISPLAY_PORT]);
2247 
2248 	xs_udp_finish_connecting(xprt, sock);
2249 	trace_rpc_socket_connect(xprt, sock, 0);
2250 	status = 0;
2251 out:
2252 	xprt_unlock_connect(xprt, transport);
2253 	xprt_clear_connecting(xprt);
2254 	xprt_wake_pending_tasks(xprt, status);
2255 }
2256 
2257 /**
2258  * xs_tcp_shutdown - gracefully shut down a TCP socket
2259  * @xprt: transport
2260  *
2261  * Initiates a graceful shutdown of the TCP socket by calling the
2262  * equivalent of shutdown(SHUT_RDWR);
2263  */
2264 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2265 {
2266 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2267 	struct socket *sock = transport->sock;
2268 
2269 	if (sock == NULL)
2270 		return;
2271 	if (xprt_connected(xprt)) {
2272 		kernel_sock_shutdown(sock, SHUT_RDWR);
2273 		trace_rpc_socket_shutdown(xprt, sock);
2274 	} else
2275 		xs_reset_transport(transport);
2276 }
2277 
2278 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2279 		struct socket *sock)
2280 {
2281 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2282 	unsigned int keepidle;
2283 	unsigned int keepcnt;
2284 	unsigned int opt_on = 1;
2285 	unsigned int timeo;
2286 
2287 	spin_lock_bh(&xprt->transport_lock);
2288 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2289 	keepcnt = xprt->timeout->to_retries + 1;
2290 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2291 		(xprt->timeout->to_retries + 1);
2292 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2293 	spin_unlock_bh(&xprt->transport_lock);
2294 
2295 	/* TCP Keepalive options */
2296 	kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2297 			(char *)&opt_on, sizeof(opt_on));
2298 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2299 			(char *)&keepidle, sizeof(keepidle));
2300 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2301 			(char *)&keepidle, sizeof(keepidle));
2302 	kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2303 			(char *)&keepcnt, sizeof(keepcnt));
2304 
2305 	/* TCP user timeout (see RFC5482) */
2306 	kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2307 			(char *)&timeo, sizeof(timeo));
2308 }
2309 
2310 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2311 		unsigned long connect_timeout,
2312 		unsigned long reconnect_timeout)
2313 {
2314 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2315 	struct rpc_timeout to;
2316 	unsigned long initval;
2317 
2318 	spin_lock_bh(&xprt->transport_lock);
2319 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2320 		xprt->max_reconnect_timeout = reconnect_timeout;
2321 	if (connect_timeout < xprt->connect_timeout) {
2322 		memcpy(&to, xprt->timeout, sizeof(to));
2323 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2324 		/* Arbitrary lower limit */
2325 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2326 			initval = XS_TCP_INIT_REEST_TO << 1;
2327 		to.to_initval = initval;
2328 		to.to_maxval = initval;
2329 		memcpy(&transport->tcp_timeout, &to,
2330 				sizeof(transport->tcp_timeout));
2331 		xprt->timeout = &transport->tcp_timeout;
2332 		xprt->connect_timeout = connect_timeout;
2333 	}
2334 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2335 	spin_unlock_bh(&xprt->transport_lock);
2336 }
2337 
2338 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2339 {
2340 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2341 	int ret = -ENOTCONN;
2342 
2343 	if (!transport->inet) {
2344 		struct sock *sk = sock->sk;
2345 		unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2346 
2347 		/* Avoid temporary address, they are bad for long-lived
2348 		 * connections such as NFS mounts.
2349 		 * RFC4941, section 3.6 suggests that:
2350 		 *    Individual applications, which have specific
2351 		 *    knowledge about the normal duration of connections,
2352 		 *    MAY override this as appropriate.
2353 		 */
2354 		kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2355 				(char *)&addr_pref, sizeof(addr_pref));
2356 
2357 		xs_tcp_set_socket_timeouts(xprt, sock);
2358 
2359 		write_lock_bh(&sk->sk_callback_lock);
2360 
2361 		xs_save_old_callbacks(transport, sk);
2362 
2363 		sk->sk_user_data = xprt;
2364 		sk->sk_data_ready = xs_data_ready;
2365 		sk->sk_state_change = xs_tcp_state_change;
2366 		sk->sk_write_space = xs_tcp_write_space;
2367 		sock_set_flag(sk, SOCK_FASYNC);
2368 		sk->sk_error_report = xs_error_report;
2369 		sk->sk_allocation = GFP_NOIO;
2370 
2371 		/* socket options */
2372 		sock_reset_flag(sk, SOCK_LINGER);
2373 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2374 
2375 		xprt_clear_connected(xprt);
2376 
2377 		/* Reset to new socket */
2378 		transport->sock = sock;
2379 		transport->inet = sk;
2380 
2381 		write_unlock_bh(&sk->sk_callback_lock);
2382 	}
2383 
2384 	if (!xprt_bound(xprt))
2385 		goto out;
2386 
2387 	xs_set_memalloc(xprt);
2388 
2389 	/* Tell the socket layer to start connecting... */
2390 	xprt->stat.connect_count++;
2391 	xprt->stat.connect_start = jiffies;
2392 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2393 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2394 	switch (ret) {
2395 	case 0:
2396 		xs_set_srcport(transport, sock);
2397 		/* fall through */
2398 	case -EINPROGRESS:
2399 		/* SYN_SENT! */
2400 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2401 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2402 		break;
2403 	case -EADDRNOTAVAIL:
2404 		/* Source port number is unavailable. Try a new one! */
2405 		transport->srcport = 0;
2406 	}
2407 out:
2408 	return ret;
2409 }
2410 
2411 /**
2412  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2413  *
2414  * Invoked by a work queue tasklet.
2415  */
2416 static void xs_tcp_setup_socket(struct work_struct *work)
2417 {
2418 	struct sock_xprt *transport =
2419 		container_of(work, struct sock_xprt, connect_worker.work);
2420 	struct socket *sock = transport->sock;
2421 	struct rpc_xprt *xprt = &transport->xprt;
2422 	int status = -EIO;
2423 
2424 	if (!sock) {
2425 		sock = xs_create_sock(xprt, transport,
2426 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2427 				IPPROTO_TCP, true);
2428 		if (IS_ERR(sock)) {
2429 			status = PTR_ERR(sock);
2430 			goto out;
2431 		}
2432 	}
2433 
2434 	dprintk("RPC:       worker connecting xprt %p via %s to "
2435 				"%s (port %s)\n", xprt,
2436 			xprt->address_strings[RPC_DISPLAY_PROTO],
2437 			xprt->address_strings[RPC_DISPLAY_ADDR],
2438 			xprt->address_strings[RPC_DISPLAY_PORT]);
2439 
2440 	status = xs_tcp_finish_connecting(xprt, sock);
2441 	trace_rpc_socket_connect(xprt, sock, status);
2442 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2443 			xprt, -status, xprt_connected(xprt),
2444 			sock->sk->sk_state);
2445 	switch (status) {
2446 	default:
2447 		printk("%s: connect returned unhandled error %d\n",
2448 			__func__, status);
2449 		/* fall through */
2450 	case -EADDRNOTAVAIL:
2451 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2452 		 * and retry
2453 		 */
2454 		xs_tcp_force_close(xprt);
2455 		break;
2456 	case 0:
2457 	case -EINPROGRESS:
2458 	case -EALREADY:
2459 		xprt_unlock_connect(xprt, transport);
2460 		return;
2461 	case -EINVAL:
2462 		/* Happens, for instance, if the user specified a link
2463 		 * local IPv6 address without a scope-id.
2464 		 */
2465 	case -ECONNREFUSED:
2466 	case -ECONNRESET:
2467 	case -ENETDOWN:
2468 	case -ENETUNREACH:
2469 	case -EHOSTUNREACH:
2470 	case -EADDRINUSE:
2471 	case -ENOBUFS:
2472 		/*
2473 		 * xs_tcp_force_close() wakes tasks with -EIO.
2474 		 * We need to wake them first to ensure the
2475 		 * correct error code.
2476 		 */
2477 		xprt_wake_pending_tasks(xprt, status);
2478 		xs_tcp_force_close(xprt);
2479 		goto out;
2480 	}
2481 	status = -EAGAIN;
2482 out:
2483 	xprt_unlock_connect(xprt, transport);
2484 	xprt_clear_connecting(xprt);
2485 	xprt_wake_pending_tasks(xprt, status);
2486 }
2487 
2488 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2489 {
2490 	unsigned long start, now = jiffies;
2491 
2492 	start = xprt->stat.connect_start + xprt->reestablish_timeout;
2493 	if (time_after(start, now))
2494 		return start - now;
2495 	return 0;
2496 }
2497 
2498 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2499 {
2500 	xprt->reestablish_timeout <<= 1;
2501 	if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2502 		xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2503 	if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2504 		xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2505 }
2506 
2507 /**
2508  * xs_connect - connect a socket to a remote endpoint
2509  * @xprt: pointer to transport structure
2510  * @task: address of RPC task that manages state of connect request
2511  *
2512  * TCP: If the remote end dropped the connection, delay reconnecting.
2513  *
2514  * UDP socket connects are synchronous, but we use a work queue anyway
2515  * to guarantee that even unprivileged user processes can set up a
2516  * socket on a privileged port.
2517  *
2518  * If a UDP socket connect fails, the delay behavior here prevents
2519  * retry floods (hard mounts).
2520  */
2521 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2522 {
2523 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2524 	unsigned long delay = 0;
2525 
2526 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2527 
2528 	if (transport->sock != NULL) {
2529 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2530 				"seconds\n",
2531 				xprt, xprt->reestablish_timeout / HZ);
2532 
2533 		/* Start by resetting any existing state */
2534 		xs_reset_transport(transport);
2535 
2536 		delay = xs_reconnect_delay(xprt);
2537 		xs_reconnect_backoff(xprt);
2538 
2539 	} else
2540 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2541 
2542 	queue_delayed_work(xprtiod_workqueue,
2543 			&transport->connect_worker,
2544 			delay);
2545 }
2546 
2547 /**
2548  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2549  * @xprt: rpc_xprt struct containing statistics
2550  * @seq: output file
2551  *
2552  */
2553 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2554 {
2555 	long idle_time = 0;
2556 
2557 	if (xprt_connected(xprt))
2558 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2559 
2560 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2561 			"%llu %llu %lu %llu %llu\n",
2562 			xprt->stat.bind_count,
2563 			xprt->stat.connect_count,
2564 			xprt->stat.connect_time,
2565 			idle_time,
2566 			xprt->stat.sends,
2567 			xprt->stat.recvs,
2568 			xprt->stat.bad_xids,
2569 			xprt->stat.req_u,
2570 			xprt->stat.bklog_u,
2571 			xprt->stat.max_slots,
2572 			xprt->stat.sending_u,
2573 			xprt->stat.pending_u);
2574 }
2575 
2576 /**
2577  * xs_udp_print_stats - display UDP socket-specifc stats
2578  * @xprt: rpc_xprt struct containing statistics
2579  * @seq: output file
2580  *
2581  */
2582 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2583 {
2584 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2585 
2586 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2587 			"%lu %llu %llu\n",
2588 			transport->srcport,
2589 			xprt->stat.bind_count,
2590 			xprt->stat.sends,
2591 			xprt->stat.recvs,
2592 			xprt->stat.bad_xids,
2593 			xprt->stat.req_u,
2594 			xprt->stat.bklog_u,
2595 			xprt->stat.max_slots,
2596 			xprt->stat.sending_u,
2597 			xprt->stat.pending_u);
2598 }
2599 
2600 /**
2601  * xs_tcp_print_stats - display TCP socket-specifc stats
2602  * @xprt: rpc_xprt struct containing statistics
2603  * @seq: output file
2604  *
2605  */
2606 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2607 {
2608 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2609 	long idle_time = 0;
2610 
2611 	if (xprt_connected(xprt))
2612 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2613 
2614 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2615 			"%llu %llu %lu %llu %llu\n",
2616 			transport->srcport,
2617 			xprt->stat.bind_count,
2618 			xprt->stat.connect_count,
2619 			xprt->stat.connect_time,
2620 			idle_time,
2621 			xprt->stat.sends,
2622 			xprt->stat.recvs,
2623 			xprt->stat.bad_xids,
2624 			xprt->stat.req_u,
2625 			xprt->stat.bklog_u,
2626 			xprt->stat.max_slots,
2627 			xprt->stat.sending_u,
2628 			xprt->stat.pending_u);
2629 }
2630 
2631 /*
2632  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2633  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2634  * to use the server side send routines.
2635  */
2636 static int bc_malloc(struct rpc_task *task)
2637 {
2638 	struct rpc_rqst *rqst = task->tk_rqstp;
2639 	size_t size = rqst->rq_callsize;
2640 	struct page *page;
2641 	struct rpc_buffer *buf;
2642 
2643 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2644 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2645 			  size);
2646 		return -EINVAL;
2647 	}
2648 
2649 	page = alloc_page(GFP_KERNEL);
2650 	if (!page)
2651 		return -ENOMEM;
2652 
2653 	buf = page_address(page);
2654 	buf->len = PAGE_SIZE;
2655 
2656 	rqst->rq_buffer = buf->data;
2657 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2658 	return 0;
2659 }
2660 
2661 /*
2662  * Free the space allocated in the bc_alloc routine
2663  */
2664 static void bc_free(struct rpc_task *task)
2665 {
2666 	void *buffer = task->tk_rqstp->rq_buffer;
2667 	struct rpc_buffer *buf;
2668 
2669 	buf = container_of(buffer, struct rpc_buffer, data);
2670 	free_page((unsigned long)buf);
2671 }
2672 
2673 /*
2674  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2675  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2676  */
2677 static int bc_sendto(struct rpc_rqst *req)
2678 {
2679 	int len;
2680 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2681 	struct rpc_xprt *xprt = req->rq_xprt;
2682 	struct sock_xprt *transport =
2683 				container_of(xprt, struct sock_xprt, xprt);
2684 	struct socket *sock = transport->sock;
2685 	unsigned long headoff;
2686 	unsigned long tailoff;
2687 
2688 	xs_encode_stream_record_marker(xbufp);
2689 
2690 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2691 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2692 	len = svc_send_common(sock, xbufp,
2693 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2694 			      xbufp->tail[0].iov_base, tailoff);
2695 
2696 	if (len != xbufp->len) {
2697 		printk(KERN_NOTICE "Error sending entire callback!\n");
2698 		len = -EAGAIN;
2699 	}
2700 
2701 	return len;
2702 }
2703 
2704 /*
2705  * The send routine. Borrows from svc_send
2706  */
2707 static int bc_send_request(struct rpc_task *task)
2708 {
2709 	struct rpc_rqst *req = task->tk_rqstp;
2710 	struct svc_xprt	*xprt;
2711 	int len;
2712 
2713 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2714 	/*
2715 	 * Get the server socket associated with this callback xprt
2716 	 */
2717 	xprt = req->rq_xprt->bc_xprt;
2718 
2719 	/*
2720 	 * Grab the mutex to serialize data as the connection is shared
2721 	 * with the fore channel
2722 	 */
2723 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2724 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2725 		if (!mutex_trylock(&xprt->xpt_mutex))
2726 			return -EAGAIN;
2727 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2728 	}
2729 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2730 		len = -ENOTCONN;
2731 	else
2732 		len = bc_sendto(req);
2733 	mutex_unlock(&xprt->xpt_mutex);
2734 
2735 	if (len > 0)
2736 		len = 0;
2737 
2738 	return len;
2739 }
2740 
2741 /*
2742  * The close routine. Since this is client initiated, we do nothing
2743  */
2744 
2745 static void bc_close(struct rpc_xprt *xprt)
2746 {
2747 }
2748 
2749 /*
2750  * The xprt destroy routine. Again, because this connection is client
2751  * initiated, we do nothing
2752  */
2753 
2754 static void bc_destroy(struct rpc_xprt *xprt)
2755 {
2756 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2757 
2758 	xs_xprt_free(xprt);
2759 	module_put(THIS_MODULE);
2760 }
2761 
2762 static const struct rpc_xprt_ops xs_local_ops = {
2763 	.reserve_xprt		= xprt_reserve_xprt,
2764 	.release_xprt		= xs_tcp_release_xprt,
2765 	.alloc_slot		= xprt_alloc_slot,
2766 	.rpcbind		= xs_local_rpcbind,
2767 	.set_port		= xs_local_set_port,
2768 	.connect		= xs_local_connect,
2769 	.buf_alloc		= rpc_malloc,
2770 	.buf_free		= rpc_free,
2771 	.send_request		= xs_local_send_request,
2772 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2773 	.close			= xs_close,
2774 	.destroy		= xs_destroy,
2775 	.print_stats		= xs_local_print_stats,
2776 	.enable_swap		= xs_enable_swap,
2777 	.disable_swap		= xs_disable_swap,
2778 };
2779 
2780 static const struct rpc_xprt_ops xs_udp_ops = {
2781 	.set_buffer_size	= xs_udp_set_buffer_size,
2782 	.reserve_xprt		= xprt_reserve_xprt_cong,
2783 	.release_xprt		= xprt_release_xprt_cong,
2784 	.alloc_slot		= xprt_alloc_slot,
2785 	.rpcbind		= rpcb_getport_async,
2786 	.set_port		= xs_set_port,
2787 	.connect		= xs_connect,
2788 	.buf_alloc		= rpc_malloc,
2789 	.buf_free		= rpc_free,
2790 	.send_request		= xs_udp_send_request,
2791 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2792 	.timer			= xs_udp_timer,
2793 	.release_request	= xprt_release_rqst_cong,
2794 	.close			= xs_close,
2795 	.destroy		= xs_destroy,
2796 	.print_stats		= xs_udp_print_stats,
2797 	.enable_swap		= xs_enable_swap,
2798 	.disable_swap		= xs_disable_swap,
2799 	.inject_disconnect	= xs_inject_disconnect,
2800 };
2801 
2802 static const struct rpc_xprt_ops xs_tcp_ops = {
2803 	.reserve_xprt		= xprt_reserve_xprt,
2804 	.release_xprt		= xs_tcp_release_xprt,
2805 	.alloc_slot		= xprt_lock_and_alloc_slot,
2806 	.rpcbind		= rpcb_getport_async,
2807 	.set_port		= xs_set_port,
2808 	.connect		= xs_connect,
2809 	.buf_alloc		= rpc_malloc,
2810 	.buf_free		= rpc_free,
2811 	.send_request		= xs_tcp_send_request,
2812 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2813 	.close			= xs_tcp_shutdown,
2814 	.destroy		= xs_destroy,
2815 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2816 	.print_stats		= xs_tcp_print_stats,
2817 	.enable_swap		= xs_enable_swap,
2818 	.disable_swap		= xs_disable_swap,
2819 	.inject_disconnect	= xs_inject_disconnect,
2820 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2821 	.bc_setup		= xprt_setup_bc,
2822 	.bc_up			= xs_tcp_bc_up,
2823 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2824 	.bc_free_rqst		= xprt_free_bc_rqst,
2825 	.bc_destroy		= xprt_destroy_bc,
2826 #endif
2827 };
2828 
2829 /*
2830  * The rpc_xprt_ops for the server backchannel
2831  */
2832 
2833 static const struct rpc_xprt_ops bc_tcp_ops = {
2834 	.reserve_xprt		= xprt_reserve_xprt,
2835 	.release_xprt		= xprt_release_xprt,
2836 	.alloc_slot		= xprt_alloc_slot,
2837 	.buf_alloc		= bc_malloc,
2838 	.buf_free		= bc_free,
2839 	.send_request		= bc_send_request,
2840 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2841 	.close			= bc_close,
2842 	.destroy		= bc_destroy,
2843 	.print_stats		= xs_tcp_print_stats,
2844 	.enable_swap		= xs_enable_swap,
2845 	.disable_swap		= xs_disable_swap,
2846 	.inject_disconnect	= xs_inject_disconnect,
2847 };
2848 
2849 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2850 {
2851 	static const struct sockaddr_in sin = {
2852 		.sin_family		= AF_INET,
2853 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2854 	};
2855 	static const struct sockaddr_in6 sin6 = {
2856 		.sin6_family		= AF_INET6,
2857 		.sin6_addr		= IN6ADDR_ANY_INIT,
2858 	};
2859 
2860 	switch (family) {
2861 	case AF_LOCAL:
2862 		break;
2863 	case AF_INET:
2864 		memcpy(sap, &sin, sizeof(sin));
2865 		break;
2866 	case AF_INET6:
2867 		memcpy(sap, &sin6, sizeof(sin6));
2868 		break;
2869 	default:
2870 		dprintk("RPC:       %s: Bad address family\n", __func__);
2871 		return -EAFNOSUPPORT;
2872 	}
2873 	return 0;
2874 }
2875 
2876 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2877 				      unsigned int slot_table_size,
2878 				      unsigned int max_slot_table_size)
2879 {
2880 	struct rpc_xprt *xprt;
2881 	struct sock_xprt *new;
2882 
2883 	if (args->addrlen > sizeof(xprt->addr)) {
2884 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2885 		return ERR_PTR(-EBADF);
2886 	}
2887 
2888 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2889 			max_slot_table_size);
2890 	if (xprt == NULL) {
2891 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2892 				"rpc_xprt\n");
2893 		return ERR_PTR(-ENOMEM);
2894 	}
2895 
2896 	new = container_of(xprt, struct sock_xprt, xprt);
2897 	mutex_init(&new->recv_mutex);
2898 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2899 	xprt->addrlen = args->addrlen;
2900 	if (args->srcaddr)
2901 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2902 	else {
2903 		int err;
2904 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2905 					(struct sockaddr *)&new->srcaddr);
2906 		if (err != 0) {
2907 			xprt_free(xprt);
2908 			return ERR_PTR(err);
2909 		}
2910 	}
2911 
2912 	return xprt;
2913 }
2914 
2915 static const struct rpc_timeout xs_local_default_timeout = {
2916 	.to_initval = 10 * HZ,
2917 	.to_maxval = 10 * HZ,
2918 	.to_retries = 2,
2919 };
2920 
2921 /**
2922  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2923  * @args: rpc transport creation arguments
2924  *
2925  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2926  */
2927 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2928 {
2929 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2930 	struct sock_xprt *transport;
2931 	struct rpc_xprt *xprt;
2932 	struct rpc_xprt *ret;
2933 
2934 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2935 			xprt_max_tcp_slot_table_entries);
2936 	if (IS_ERR(xprt))
2937 		return xprt;
2938 	transport = container_of(xprt, struct sock_xprt, xprt);
2939 
2940 	xprt->prot = 0;
2941 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2942 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2943 
2944 	xprt->bind_timeout = XS_BIND_TO;
2945 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2946 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2947 
2948 	xprt->ops = &xs_local_ops;
2949 	xprt->timeout = &xs_local_default_timeout;
2950 
2951 	INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2952 	INIT_DELAYED_WORK(&transport->connect_worker,
2953 			xs_dummy_setup_socket);
2954 
2955 	switch (sun->sun_family) {
2956 	case AF_LOCAL:
2957 		if (sun->sun_path[0] != '/') {
2958 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2959 					sun->sun_path);
2960 			ret = ERR_PTR(-EINVAL);
2961 			goto out_err;
2962 		}
2963 		xprt_set_bound(xprt);
2964 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2965 		ret = ERR_PTR(xs_local_setup_socket(transport));
2966 		if (ret)
2967 			goto out_err;
2968 		break;
2969 	default:
2970 		ret = ERR_PTR(-EAFNOSUPPORT);
2971 		goto out_err;
2972 	}
2973 
2974 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2975 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2976 
2977 	if (try_module_get(THIS_MODULE))
2978 		return xprt;
2979 	ret = ERR_PTR(-EINVAL);
2980 out_err:
2981 	xs_xprt_free(xprt);
2982 	return ret;
2983 }
2984 
2985 static const struct rpc_timeout xs_udp_default_timeout = {
2986 	.to_initval = 5 * HZ,
2987 	.to_maxval = 30 * HZ,
2988 	.to_increment = 5 * HZ,
2989 	.to_retries = 5,
2990 };
2991 
2992 /**
2993  * xs_setup_udp - Set up transport to use a UDP socket
2994  * @args: rpc transport creation arguments
2995  *
2996  */
2997 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2998 {
2999 	struct sockaddr *addr = args->dstaddr;
3000 	struct rpc_xprt *xprt;
3001 	struct sock_xprt *transport;
3002 	struct rpc_xprt *ret;
3003 
3004 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
3005 			xprt_udp_slot_table_entries);
3006 	if (IS_ERR(xprt))
3007 		return xprt;
3008 	transport = container_of(xprt, struct sock_xprt, xprt);
3009 
3010 	xprt->prot = IPPROTO_UDP;
3011 	xprt->tsh_size = 0;
3012 	/* XXX: header size can vary due to auth type, IPv6, etc. */
3013 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
3014 
3015 	xprt->bind_timeout = XS_BIND_TO;
3016 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
3017 	xprt->idle_timeout = XS_IDLE_DISC_TO;
3018 
3019 	xprt->ops = &xs_udp_ops;
3020 
3021 	xprt->timeout = &xs_udp_default_timeout;
3022 
3023 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
3024 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
3025 
3026 	switch (addr->sa_family) {
3027 	case AF_INET:
3028 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3029 			xprt_set_bound(xprt);
3030 
3031 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
3032 		break;
3033 	case AF_INET6:
3034 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3035 			xprt_set_bound(xprt);
3036 
3037 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
3038 		break;
3039 	default:
3040 		ret = ERR_PTR(-EAFNOSUPPORT);
3041 		goto out_err;
3042 	}
3043 
3044 	if (xprt_bound(xprt))
3045 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3046 				xprt->address_strings[RPC_DISPLAY_ADDR],
3047 				xprt->address_strings[RPC_DISPLAY_PORT],
3048 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3049 	else
3050 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3051 				xprt->address_strings[RPC_DISPLAY_ADDR],
3052 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3053 
3054 	if (try_module_get(THIS_MODULE))
3055 		return xprt;
3056 	ret = ERR_PTR(-EINVAL);
3057 out_err:
3058 	xs_xprt_free(xprt);
3059 	return ret;
3060 }
3061 
3062 static const struct rpc_timeout xs_tcp_default_timeout = {
3063 	.to_initval = 60 * HZ,
3064 	.to_maxval = 60 * HZ,
3065 	.to_retries = 2,
3066 };
3067 
3068 /**
3069  * xs_setup_tcp - Set up transport to use a TCP socket
3070  * @args: rpc transport creation arguments
3071  *
3072  */
3073 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
3074 {
3075 	struct sockaddr *addr = args->dstaddr;
3076 	struct rpc_xprt *xprt;
3077 	struct sock_xprt *transport;
3078 	struct rpc_xprt *ret;
3079 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3080 
3081 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3082 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3083 
3084 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3085 			max_slot_table_size);
3086 	if (IS_ERR(xprt))
3087 		return xprt;
3088 	transport = container_of(xprt, struct sock_xprt, xprt);
3089 
3090 	xprt->prot = IPPROTO_TCP;
3091 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3092 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3093 
3094 	xprt->bind_timeout = XS_BIND_TO;
3095 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3096 	xprt->idle_timeout = XS_IDLE_DISC_TO;
3097 
3098 	xprt->ops = &xs_tcp_ops;
3099 	xprt->timeout = &xs_tcp_default_timeout;
3100 
3101 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3102 	xprt->connect_timeout = xprt->timeout->to_initval *
3103 		(xprt->timeout->to_retries + 1);
3104 
3105 	INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
3106 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3107 
3108 	switch (addr->sa_family) {
3109 	case AF_INET:
3110 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3111 			xprt_set_bound(xprt);
3112 
3113 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3114 		break;
3115 	case AF_INET6:
3116 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3117 			xprt_set_bound(xprt);
3118 
3119 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3120 		break;
3121 	default:
3122 		ret = ERR_PTR(-EAFNOSUPPORT);
3123 		goto out_err;
3124 	}
3125 
3126 	if (xprt_bound(xprt))
3127 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3128 				xprt->address_strings[RPC_DISPLAY_ADDR],
3129 				xprt->address_strings[RPC_DISPLAY_PORT],
3130 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3131 	else
3132 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3133 				xprt->address_strings[RPC_DISPLAY_ADDR],
3134 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3135 
3136 	if (try_module_get(THIS_MODULE))
3137 		return xprt;
3138 	ret = ERR_PTR(-EINVAL);
3139 out_err:
3140 	xs_xprt_free(xprt);
3141 	return ret;
3142 }
3143 
3144 /**
3145  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3146  * @args: rpc transport creation arguments
3147  *
3148  */
3149 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3150 {
3151 	struct sockaddr *addr = args->dstaddr;
3152 	struct rpc_xprt *xprt;
3153 	struct sock_xprt *transport;
3154 	struct svc_sock *bc_sock;
3155 	struct rpc_xprt *ret;
3156 
3157 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3158 			xprt_tcp_slot_table_entries);
3159 	if (IS_ERR(xprt))
3160 		return xprt;
3161 	transport = container_of(xprt, struct sock_xprt, xprt);
3162 
3163 	xprt->prot = IPPROTO_TCP;
3164 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3165 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3166 	xprt->timeout = &xs_tcp_default_timeout;
3167 
3168 	/* backchannel */
3169 	xprt_set_bound(xprt);
3170 	xprt->bind_timeout = 0;
3171 	xprt->reestablish_timeout = 0;
3172 	xprt->idle_timeout = 0;
3173 
3174 	xprt->ops = &bc_tcp_ops;
3175 
3176 	switch (addr->sa_family) {
3177 	case AF_INET:
3178 		xs_format_peer_addresses(xprt, "tcp",
3179 					 RPCBIND_NETID_TCP);
3180 		break;
3181 	case AF_INET6:
3182 		xs_format_peer_addresses(xprt, "tcp",
3183 				   RPCBIND_NETID_TCP6);
3184 		break;
3185 	default:
3186 		ret = ERR_PTR(-EAFNOSUPPORT);
3187 		goto out_err;
3188 	}
3189 
3190 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3191 			xprt->address_strings[RPC_DISPLAY_ADDR],
3192 			xprt->address_strings[RPC_DISPLAY_PORT],
3193 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3194 
3195 	/*
3196 	 * Once we've associated a backchannel xprt with a connection,
3197 	 * we want to keep it around as long as the connection lasts,
3198 	 * in case we need to start using it for a backchannel again;
3199 	 * this reference won't be dropped until bc_xprt is destroyed.
3200 	 */
3201 	xprt_get(xprt);
3202 	args->bc_xprt->xpt_bc_xprt = xprt;
3203 	xprt->bc_xprt = args->bc_xprt;
3204 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3205 	transport->sock = bc_sock->sk_sock;
3206 	transport->inet = bc_sock->sk_sk;
3207 
3208 	/*
3209 	 * Since we don't want connections for the backchannel, we set
3210 	 * the xprt status to connected
3211 	 */
3212 	xprt_set_connected(xprt);
3213 
3214 	if (try_module_get(THIS_MODULE))
3215 		return xprt;
3216 
3217 	args->bc_xprt->xpt_bc_xprt = NULL;
3218 	args->bc_xprt->xpt_bc_xps = NULL;
3219 	xprt_put(xprt);
3220 	ret = ERR_PTR(-EINVAL);
3221 out_err:
3222 	xs_xprt_free(xprt);
3223 	return ret;
3224 }
3225 
3226 static struct xprt_class	xs_local_transport = {
3227 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3228 	.name		= "named UNIX socket",
3229 	.owner		= THIS_MODULE,
3230 	.ident		= XPRT_TRANSPORT_LOCAL,
3231 	.setup		= xs_setup_local,
3232 };
3233 
3234 static struct xprt_class	xs_udp_transport = {
3235 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3236 	.name		= "udp",
3237 	.owner		= THIS_MODULE,
3238 	.ident		= XPRT_TRANSPORT_UDP,
3239 	.setup		= xs_setup_udp,
3240 };
3241 
3242 static struct xprt_class	xs_tcp_transport = {
3243 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3244 	.name		= "tcp",
3245 	.owner		= THIS_MODULE,
3246 	.ident		= XPRT_TRANSPORT_TCP,
3247 	.setup		= xs_setup_tcp,
3248 };
3249 
3250 static struct xprt_class	xs_bc_tcp_transport = {
3251 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3252 	.name		= "tcp NFSv4.1 backchannel",
3253 	.owner		= THIS_MODULE,
3254 	.ident		= XPRT_TRANSPORT_BC_TCP,
3255 	.setup		= xs_setup_bc_tcp,
3256 };
3257 
3258 /**
3259  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3260  *
3261  */
3262 int init_socket_xprt(void)
3263 {
3264 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3265 	if (!sunrpc_table_header)
3266 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3267 #endif
3268 
3269 	xprt_register_transport(&xs_local_transport);
3270 	xprt_register_transport(&xs_udp_transport);
3271 	xprt_register_transport(&xs_tcp_transport);
3272 	xprt_register_transport(&xs_bc_tcp_transport);
3273 
3274 	return 0;
3275 }
3276 
3277 /**
3278  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3279  *
3280  */
3281 void cleanup_socket_xprt(void)
3282 {
3283 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3284 	if (sunrpc_table_header) {
3285 		unregister_sysctl_table(sunrpc_table_header);
3286 		sunrpc_table_header = NULL;
3287 	}
3288 #endif
3289 
3290 	xprt_unregister_transport(&xs_local_transport);
3291 	xprt_unregister_transport(&xs_udp_transport);
3292 	xprt_unregister_transport(&xs_tcp_transport);
3293 	xprt_unregister_transport(&xs_bc_tcp_transport);
3294 }
3295 
3296 static int param_set_uint_minmax(const char *val,
3297 		const struct kernel_param *kp,
3298 		unsigned int min, unsigned int max)
3299 {
3300 	unsigned int num;
3301 	int ret;
3302 
3303 	if (!val)
3304 		return -EINVAL;
3305 	ret = kstrtouint(val, 0, &num);
3306 	if (ret)
3307 		return ret;
3308 	if (num < min || num > max)
3309 		return -EINVAL;
3310 	*((unsigned int *)kp->arg) = num;
3311 	return 0;
3312 }
3313 
3314 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3315 {
3316 	if (kp->arg == &xprt_min_resvport)
3317 		return param_set_uint_minmax(val, kp,
3318 			RPC_MIN_RESVPORT,
3319 			xprt_max_resvport);
3320 	return param_set_uint_minmax(val, kp,
3321 			xprt_min_resvport,
3322 			RPC_MAX_RESVPORT);
3323 }
3324 
3325 static const struct kernel_param_ops param_ops_portnr = {
3326 	.set = param_set_portnr,
3327 	.get = param_get_uint,
3328 };
3329 
3330 #define param_check_portnr(name, p) \
3331 	__param_check(name, p, unsigned int);
3332 
3333 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3334 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3335 
3336 static int param_set_slot_table_size(const char *val,
3337 				     const struct kernel_param *kp)
3338 {
3339 	return param_set_uint_minmax(val, kp,
3340 			RPC_MIN_SLOT_TABLE,
3341 			RPC_MAX_SLOT_TABLE);
3342 }
3343 
3344 static const struct kernel_param_ops param_ops_slot_table_size = {
3345 	.set = param_set_slot_table_size,
3346 	.get = param_get_uint,
3347 };
3348 
3349 #define param_check_slot_table_size(name, p) \
3350 	__param_check(name, p, unsigned int);
3351 
3352 static int param_set_max_slot_table_size(const char *val,
3353 				     const struct kernel_param *kp)
3354 {
3355 	return param_set_uint_minmax(val, kp,
3356 			RPC_MIN_SLOT_TABLE,
3357 			RPC_MAX_SLOT_TABLE_LIMIT);
3358 }
3359 
3360 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3361 	.set = param_set_max_slot_table_size,
3362 	.get = param_get_uint,
3363 };
3364 
3365 #define param_check_max_slot_table_size(name, p) \
3366 	__param_check(name, p, unsigned int);
3367 
3368 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3369 		   slot_table_size, 0644);
3370 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3371 		   max_slot_table_size, 0644);
3372 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3373 		   slot_table_size, 0644);
3374 
3375