xref: /linux/net/sunrpc/xprtsock.c (revision 56d06fa29edd58c448766014afd833b7ff51247b)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44 
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49 
50 #include <trace/events/sunrpc.h>
51 
52 #include "sunrpc.h"
53 
54 static void xs_close(struct rpc_xprt *xprt);
55 
56 /*
57  * xprtsock tunables
58  */
59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
62 
63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
65 
66 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
67 
68 #define XS_TCP_LINGER_TO	(15U * HZ)
69 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
70 
71 /*
72  * We can register our own files under /proc/sys/sunrpc by
73  * calling register_sysctl_table() again.  The files in that
74  * directory become the union of all files registered there.
75  *
76  * We simply need to make sure that we don't collide with
77  * someone else's file names!
78  */
79 
80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
85 
86 static struct ctl_table_header *sunrpc_table_header;
87 
88 /*
89  * FIXME: changing the UDP slot table size should also resize the UDP
90  *        socket buffers for existing UDP transports
91  */
92 static struct ctl_table xs_tunables_table[] = {
93 	{
94 		.procname	= "udp_slot_table_entries",
95 		.data		= &xprt_udp_slot_table_entries,
96 		.maxlen		= sizeof(unsigned int),
97 		.mode		= 0644,
98 		.proc_handler	= proc_dointvec_minmax,
99 		.extra1		= &min_slot_table_size,
100 		.extra2		= &max_slot_table_size
101 	},
102 	{
103 		.procname	= "tcp_slot_table_entries",
104 		.data		= &xprt_tcp_slot_table_entries,
105 		.maxlen		= sizeof(unsigned int),
106 		.mode		= 0644,
107 		.proc_handler	= proc_dointvec_minmax,
108 		.extra1		= &min_slot_table_size,
109 		.extra2		= &max_slot_table_size
110 	},
111 	{
112 		.procname	= "tcp_max_slot_table_entries",
113 		.data		= &xprt_max_tcp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_tcp_slot_table_limit
119 	},
120 	{
121 		.procname	= "min_resvport",
122 		.data		= &xprt_min_resvport,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &xprt_min_resvport_limit,
127 		.extra2		= &xprt_max_resvport_limit
128 	},
129 	{
130 		.procname	= "max_resvport",
131 		.data		= &xprt_max_resvport,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &xprt_min_resvport_limit,
136 		.extra2		= &xprt_max_resvport_limit
137 	},
138 	{
139 		.procname	= "tcp_fin_timeout",
140 		.data		= &xs_tcp_fin_timeout,
141 		.maxlen		= sizeof(xs_tcp_fin_timeout),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_jiffies,
144 	},
145 	{ },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149 	{
150 		.procname	= "sunrpc",
151 		.mode		= 0555,
152 		.child		= xs_tunables_table
153 	},
154 	{ },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO		(60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO		(2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
180 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
188 
189 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
190 # undef  RPC_DEBUG_DATA
191 # define RPCDBG_FACILITY	RPCDBG_TRANS
192 #endif
193 
194 #ifdef RPC_DEBUG_DATA
195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
196 {
197 	u8 *buf = (u8 *) packet;
198 	int j;
199 
200 	dprintk("RPC:       %s\n", msg);
201 	for (j = 0; j < count && j < 128; j += 4) {
202 		if (!(j & 31)) {
203 			if (j)
204 				dprintk("\n");
205 			dprintk("0x%04x ", j);
206 		}
207 		dprintk("%02x%02x%02x%02x ",
208 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
209 	}
210 	dprintk("\n");
211 }
212 #else
213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
214 {
215 	/* NOP */
216 }
217 #endif
218 
219 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
220 {
221 	return (struct rpc_xprt *) sk->sk_user_data;
222 }
223 
224 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
225 {
226 	return (struct sockaddr *) &xprt->addr;
227 }
228 
229 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
230 {
231 	return (struct sockaddr_un *) &xprt->addr;
232 }
233 
234 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
235 {
236 	return (struct sockaddr_in *) &xprt->addr;
237 }
238 
239 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
240 {
241 	return (struct sockaddr_in6 *) &xprt->addr;
242 }
243 
244 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
245 {
246 	struct sockaddr *sap = xs_addr(xprt);
247 	struct sockaddr_in6 *sin6;
248 	struct sockaddr_in *sin;
249 	struct sockaddr_un *sun;
250 	char buf[128];
251 
252 	switch (sap->sa_family) {
253 	case AF_LOCAL:
254 		sun = xs_addr_un(xprt);
255 		strlcpy(buf, sun->sun_path, sizeof(buf));
256 		xprt->address_strings[RPC_DISPLAY_ADDR] =
257 						kstrdup(buf, GFP_KERNEL);
258 		break;
259 	case AF_INET:
260 		(void)rpc_ntop(sap, buf, sizeof(buf));
261 		xprt->address_strings[RPC_DISPLAY_ADDR] =
262 						kstrdup(buf, GFP_KERNEL);
263 		sin = xs_addr_in(xprt);
264 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
265 		break;
266 	case AF_INET6:
267 		(void)rpc_ntop(sap, buf, sizeof(buf));
268 		xprt->address_strings[RPC_DISPLAY_ADDR] =
269 						kstrdup(buf, GFP_KERNEL);
270 		sin6 = xs_addr_in6(xprt);
271 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
272 		break;
273 	default:
274 		BUG();
275 	}
276 
277 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
278 }
279 
280 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
281 {
282 	struct sockaddr *sap = xs_addr(xprt);
283 	char buf[128];
284 
285 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
286 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
287 
288 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
290 }
291 
292 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
293 				     const char *protocol,
294 				     const char *netid)
295 {
296 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
297 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
298 	xs_format_common_peer_addresses(xprt);
299 	xs_format_common_peer_ports(xprt);
300 }
301 
302 static void xs_update_peer_port(struct rpc_xprt *xprt)
303 {
304 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
305 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
306 
307 	xs_format_common_peer_ports(xprt);
308 }
309 
310 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
311 {
312 	unsigned int i;
313 
314 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
315 		switch (i) {
316 		case RPC_DISPLAY_PROTO:
317 		case RPC_DISPLAY_NETID:
318 			continue;
319 		default:
320 			kfree(xprt->address_strings[i]);
321 		}
322 }
323 
324 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
325 
326 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
327 {
328 	struct msghdr msg = {
329 		.msg_name	= addr,
330 		.msg_namelen	= addrlen,
331 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
332 	};
333 	struct kvec iov = {
334 		.iov_base	= vec->iov_base + base,
335 		.iov_len	= vec->iov_len - base,
336 	};
337 
338 	if (iov.iov_len != 0)
339 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
340 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
341 }
342 
343 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
344 {
345 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
346 			int offset, size_t size, int flags);
347 	struct page **ppage;
348 	unsigned int remainder;
349 	int err;
350 
351 	remainder = xdr->page_len - base;
352 	base += xdr->page_base;
353 	ppage = xdr->pages + (base >> PAGE_SHIFT);
354 	base &= ~PAGE_MASK;
355 	do_sendpage = sock->ops->sendpage;
356 	if (!zerocopy)
357 		do_sendpage = sock_no_sendpage;
358 	for(;;) {
359 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
360 		int flags = XS_SENDMSG_FLAGS;
361 
362 		remainder -= len;
363 		if (more)
364 			flags |= MSG_MORE;
365 		if (remainder != 0)
366 			flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
367 		err = do_sendpage(sock, *ppage, base, len, flags);
368 		if (remainder == 0 || err != len)
369 			break;
370 		*sent_p += err;
371 		ppage++;
372 		base = 0;
373 	}
374 	if (err > 0) {
375 		*sent_p += err;
376 		err = 0;
377 	}
378 	return err;
379 }
380 
381 /**
382  * xs_sendpages - write pages directly to a socket
383  * @sock: socket to send on
384  * @addr: UDP only -- address of destination
385  * @addrlen: UDP only -- length of destination address
386  * @xdr: buffer containing this request
387  * @base: starting position in the buffer
388  * @zerocopy: true if it is safe to use sendpage()
389  * @sent_p: return the total number of bytes successfully queued for sending
390  *
391  */
392 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
393 {
394 	unsigned int remainder = xdr->len - base;
395 	int err = 0;
396 	int sent = 0;
397 
398 	if (unlikely(!sock))
399 		return -ENOTSOCK;
400 
401 	if (base != 0) {
402 		addr = NULL;
403 		addrlen = 0;
404 	}
405 
406 	if (base < xdr->head[0].iov_len || addr != NULL) {
407 		unsigned int len = xdr->head[0].iov_len - base;
408 		remainder -= len;
409 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
410 		if (remainder == 0 || err != len)
411 			goto out;
412 		*sent_p += err;
413 		base = 0;
414 	} else
415 		base -= xdr->head[0].iov_len;
416 
417 	if (base < xdr->page_len) {
418 		unsigned int len = xdr->page_len - base;
419 		remainder -= len;
420 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
421 		*sent_p += sent;
422 		if (remainder == 0 || sent != len)
423 			goto out;
424 		base = 0;
425 	} else
426 		base -= xdr->page_len;
427 
428 	if (base >= xdr->tail[0].iov_len)
429 		return 0;
430 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
431 out:
432 	if (err > 0) {
433 		*sent_p += err;
434 		err = 0;
435 	}
436 	return err;
437 }
438 
439 static void xs_nospace_callback(struct rpc_task *task)
440 {
441 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
442 
443 	transport->inet->sk_write_pending--;
444 }
445 
446 /**
447  * xs_nospace - place task on wait queue if transmit was incomplete
448  * @task: task to put to sleep
449  *
450  */
451 static int xs_nospace(struct rpc_task *task)
452 {
453 	struct rpc_rqst *req = task->tk_rqstp;
454 	struct rpc_xprt *xprt = req->rq_xprt;
455 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
456 	struct sock *sk = transport->inet;
457 	int ret = -EAGAIN;
458 
459 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
460 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
461 			req->rq_slen);
462 
463 	/* Protect against races with write_space */
464 	spin_lock_bh(&xprt->transport_lock);
465 
466 	/* Don't race with disconnect */
467 	if (xprt_connected(xprt)) {
468 		/* wait for more buffer space */
469 		sk->sk_write_pending++;
470 		xprt_wait_for_buffer_space(task, xs_nospace_callback);
471 	} else
472 		ret = -ENOTCONN;
473 
474 	spin_unlock_bh(&xprt->transport_lock);
475 
476 	/* Race breaker in case memory is freed before above code is called */
477 	sk->sk_write_space(sk);
478 	return ret;
479 }
480 
481 /*
482  * Construct a stream transport record marker in @buf.
483  */
484 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
485 {
486 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
487 	rpc_fraghdr *base = buf->head[0].iov_base;
488 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
489 }
490 
491 /**
492  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
493  * @task: RPC task that manages the state of an RPC request
494  *
495  * Return values:
496  *        0:	The request has been sent
497  *   EAGAIN:	The socket was blocked, please call again later to
498  *		complete the request
499  * ENOTCONN:	Caller needs to invoke connect logic then call again
500  *    other:	Some other error occured, the request was not sent
501  */
502 static int xs_local_send_request(struct rpc_task *task)
503 {
504 	struct rpc_rqst *req = task->tk_rqstp;
505 	struct rpc_xprt *xprt = req->rq_xprt;
506 	struct sock_xprt *transport =
507 				container_of(xprt, struct sock_xprt, xprt);
508 	struct xdr_buf *xdr = &req->rq_snd_buf;
509 	int status;
510 	int sent = 0;
511 
512 	xs_encode_stream_record_marker(&req->rq_snd_buf);
513 
514 	xs_pktdump("packet data:",
515 			req->rq_svec->iov_base, req->rq_svec->iov_len);
516 
517 	status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
518 			      true, &sent);
519 	dprintk("RPC:       %s(%u) = %d\n",
520 			__func__, xdr->len - req->rq_bytes_sent, status);
521 
522 	if (status == -EAGAIN && sock_writeable(transport->inet))
523 		status = -ENOBUFS;
524 
525 	if (likely(sent > 0) || status == 0) {
526 		req->rq_bytes_sent += sent;
527 		req->rq_xmit_bytes_sent += sent;
528 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
529 			req->rq_bytes_sent = 0;
530 			return 0;
531 		}
532 		status = -EAGAIN;
533 	}
534 
535 	switch (status) {
536 	case -ENOBUFS:
537 		break;
538 	case -EAGAIN:
539 		status = xs_nospace(task);
540 		break;
541 	default:
542 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
543 			-status);
544 	case -EPIPE:
545 		xs_close(xprt);
546 		status = -ENOTCONN;
547 	}
548 
549 	return status;
550 }
551 
552 /**
553  * xs_udp_send_request - write an RPC request to a UDP socket
554  * @task: address of RPC task that manages the state of an RPC request
555  *
556  * Return values:
557  *        0:	The request has been sent
558  *   EAGAIN:	The socket was blocked, please call again later to
559  *		complete the request
560  * ENOTCONN:	Caller needs to invoke connect logic then call again
561  *    other:	Some other error occurred, the request was not sent
562  */
563 static int xs_udp_send_request(struct rpc_task *task)
564 {
565 	struct rpc_rqst *req = task->tk_rqstp;
566 	struct rpc_xprt *xprt = req->rq_xprt;
567 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
568 	struct xdr_buf *xdr = &req->rq_snd_buf;
569 	int sent = 0;
570 	int status;
571 
572 	xs_pktdump("packet data:",
573 				req->rq_svec->iov_base,
574 				req->rq_svec->iov_len);
575 
576 	if (!xprt_bound(xprt))
577 		return -ENOTCONN;
578 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
579 			      xdr, req->rq_bytes_sent, true, &sent);
580 
581 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
582 			xdr->len - req->rq_bytes_sent, status);
583 
584 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
585 	if (status == -EPERM)
586 		goto process_status;
587 
588 	if (status == -EAGAIN && sock_writeable(transport->inet))
589 		status = -ENOBUFS;
590 
591 	if (sent > 0 || status == 0) {
592 		req->rq_xmit_bytes_sent += sent;
593 		if (sent >= req->rq_slen)
594 			return 0;
595 		/* Still some bytes left; set up for a retry later. */
596 		status = -EAGAIN;
597 	}
598 
599 process_status:
600 	switch (status) {
601 	case -ENOTSOCK:
602 		status = -ENOTCONN;
603 		/* Should we call xs_close() here? */
604 		break;
605 	case -EAGAIN:
606 		status = xs_nospace(task);
607 		break;
608 	case -ENETUNREACH:
609 	case -ENOBUFS:
610 	case -EPIPE:
611 	case -ECONNREFUSED:
612 	case -EPERM:
613 		/* When the server has died, an ICMP port unreachable message
614 		 * prompts ECONNREFUSED. */
615 		break;
616 	default:
617 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
618 			-status);
619 	}
620 
621 	return status;
622 }
623 
624 /**
625  * xs_tcp_send_request - write an RPC request to a TCP socket
626  * @task: address of RPC task that manages the state of an RPC request
627  *
628  * Return values:
629  *        0:	The request has been sent
630  *   EAGAIN:	The socket was blocked, please call again later to
631  *		complete the request
632  * ENOTCONN:	Caller needs to invoke connect logic then call again
633  *    other:	Some other error occurred, the request was not sent
634  *
635  * XXX: In the case of soft timeouts, should we eventually give up
636  *	if sendmsg is not able to make progress?
637  */
638 static int xs_tcp_send_request(struct rpc_task *task)
639 {
640 	struct rpc_rqst *req = task->tk_rqstp;
641 	struct rpc_xprt *xprt = req->rq_xprt;
642 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
643 	struct xdr_buf *xdr = &req->rq_snd_buf;
644 	bool zerocopy = true;
645 	int status;
646 	int sent;
647 
648 	xs_encode_stream_record_marker(&req->rq_snd_buf);
649 
650 	xs_pktdump("packet data:",
651 				req->rq_svec->iov_base,
652 				req->rq_svec->iov_len);
653 	/* Don't use zero copy if this is a resend. If the RPC call
654 	 * completes while the socket holds a reference to the pages,
655 	 * then we may end up resending corrupted data.
656 	 */
657 	if (task->tk_flags & RPC_TASK_SENT)
658 		zerocopy = false;
659 
660 	/* Continue transmitting the packet/record. We must be careful
661 	 * to cope with writespace callbacks arriving _after_ we have
662 	 * called sendmsg(). */
663 	while (1) {
664 		sent = 0;
665 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
666 				      req->rq_bytes_sent, zerocopy, &sent);
667 
668 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
669 				xdr->len - req->rq_bytes_sent, status);
670 
671 		/* If we've sent the entire packet, immediately
672 		 * reset the count of bytes sent. */
673 		req->rq_bytes_sent += sent;
674 		req->rq_xmit_bytes_sent += sent;
675 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
676 			req->rq_bytes_sent = 0;
677 			return 0;
678 		}
679 
680 		if (status < 0)
681 			break;
682 		if (sent == 0) {
683 			status = -EAGAIN;
684 			break;
685 		}
686 	}
687 	if (status == -EAGAIN && sk_stream_is_writeable(transport->inet))
688 		status = -ENOBUFS;
689 
690 	switch (status) {
691 	case -ENOTSOCK:
692 		status = -ENOTCONN;
693 		/* Should we call xs_close() here? */
694 		break;
695 	case -EAGAIN:
696 		status = xs_nospace(task);
697 		break;
698 	case -ECONNRESET:
699 	case -ECONNREFUSED:
700 	case -ENOTCONN:
701 	case -EADDRINUSE:
702 	case -ENOBUFS:
703 	case -EPIPE:
704 		break;
705 	default:
706 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
707 			-status);
708 	}
709 
710 	return status;
711 }
712 
713 /**
714  * xs_tcp_release_xprt - clean up after a tcp transmission
715  * @xprt: transport
716  * @task: rpc task
717  *
718  * This cleans up if an error causes us to abort the transmission of a request.
719  * In this case, the socket may need to be reset in order to avoid confusing
720  * the server.
721  */
722 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
723 {
724 	struct rpc_rqst *req;
725 
726 	if (task != xprt->snd_task)
727 		return;
728 	if (task == NULL)
729 		goto out_release;
730 	req = task->tk_rqstp;
731 	if (req == NULL)
732 		goto out_release;
733 	if (req->rq_bytes_sent == 0)
734 		goto out_release;
735 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
736 		goto out_release;
737 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
738 out_release:
739 	xprt_release_xprt(xprt, task);
740 }
741 
742 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
743 {
744 	transport->old_data_ready = sk->sk_data_ready;
745 	transport->old_state_change = sk->sk_state_change;
746 	transport->old_write_space = sk->sk_write_space;
747 	transport->old_error_report = sk->sk_error_report;
748 }
749 
750 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
751 {
752 	sk->sk_data_ready = transport->old_data_ready;
753 	sk->sk_state_change = transport->old_state_change;
754 	sk->sk_write_space = transport->old_write_space;
755 	sk->sk_error_report = transport->old_error_report;
756 }
757 
758 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
759 {
760 	smp_mb__before_atomic();
761 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
762 	clear_bit(XPRT_CLOSING, &xprt->state);
763 	smp_mb__after_atomic();
764 }
765 
766 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
767 {
768 	xs_sock_reset_connection_flags(xprt);
769 	/* Mark transport as closed and wake up all pending tasks */
770 	xprt_disconnect_done(xprt);
771 }
772 
773 /**
774  * xs_error_report - callback to handle TCP socket state errors
775  * @sk: socket
776  *
777  * Note: we don't call sock_error() since there may be a rpc_task
778  * using the socket, and so we don't want to clear sk->sk_err.
779  */
780 static void xs_error_report(struct sock *sk)
781 {
782 	struct rpc_xprt *xprt;
783 	int err;
784 
785 	read_lock_bh(&sk->sk_callback_lock);
786 	if (!(xprt = xprt_from_sock(sk)))
787 		goto out;
788 
789 	err = -sk->sk_err;
790 	if (err == 0)
791 		goto out;
792 	/* Is this a reset event? */
793 	if (sk->sk_state == TCP_CLOSE)
794 		xs_sock_mark_closed(xprt);
795 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
796 			xprt, -err);
797 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
798 	xprt_wake_pending_tasks(xprt, err);
799  out:
800 	read_unlock_bh(&sk->sk_callback_lock);
801 }
802 
803 static void xs_reset_transport(struct sock_xprt *transport)
804 {
805 	struct socket *sock = transport->sock;
806 	struct sock *sk = transport->inet;
807 	struct rpc_xprt *xprt = &transport->xprt;
808 
809 	if (sk == NULL)
810 		return;
811 
812 	if (atomic_read(&transport->xprt.swapper))
813 		sk_clear_memalloc(sk);
814 
815 	kernel_sock_shutdown(sock, SHUT_RDWR);
816 
817 	mutex_lock(&transport->recv_mutex);
818 	write_lock_bh(&sk->sk_callback_lock);
819 	transport->inet = NULL;
820 	transport->sock = NULL;
821 
822 	sk->sk_user_data = NULL;
823 
824 	xs_restore_old_callbacks(transport, sk);
825 	xprt_clear_connected(xprt);
826 	write_unlock_bh(&sk->sk_callback_lock);
827 	xs_sock_reset_connection_flags(xprt);
828 	mutex_unlock(&transport->recv_mutex);
829 
830 	trace_rpc_socket_close(xprt, sock);
831 	sock_release(sock);
832 }
833 
834 /**
835  * xs_close - close a socket
836  * @xprt: transport
837  *
838  * This is used when all requests are complete; ie, no DRC state remains
839  * on the server we want to save.
840  *
841  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
842  * xs_reset_transport() zeroing the socket from underneath a writer.
843  */
844 static void xs_close(struct rpc_xprt *xprt)
845 {
846 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
847 
848 	dprintk("RPC:       xs_close xprt %p\n", xprt);
849 
850 	xs_reset_transport(transport);
851 	xprt->reestablish_timeout = 0;
852 
853 	xprt_disconnect_done(xprt);
854 }
855 
856 static void xs_inject_disconnect(struct rpc_xprt *xprt)
857 {
858 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
859 		xprt);
860 	xprt_disconnect_done(xprt);
861 }
862 
863 static void xs_xprt_free(struct rpc_xprt *xprt)
864 {
865 	xs_free_peer_addresses(xprt);
866 	xprt_free(xprt);
867 }
868 
869 /**
870  * xs_destroy - prepare to shutdown a transport
871  * @xprt: doomed transport
872  *
873  */
874 static void xs_destroy(struct rpc_xprt *xprt)
875 {
876 	struct sock_xprt *transport = container_of(xprt,
877 			struct sock_xprt, xprt);
878 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
879 
880 	cancel_delayed_work_sync(&transport->connect_worker);
881 	xs_close(xprt);
882 	cancel_work_sync(&transport->recv_worker);
883 	xs_xprt_free(xprt);
884 	module_put(THIS_MODULE);
885 }
886 
887 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
888 {
889 	struct xdr_skb_reader desc = {
890 		.skb		= skb,
891 		.offset		= sizeof(rpc_fraghdr),
892 		.count		= skb->len - sizeof(rpc_fraghdr),
893 	};
894 
895 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
896 		return -1;
897 	if (desc.count)
898 		return -1;
899 	return 0;
900 }
901 
902 /**
903  * xs_local_data_read_skb
904  * @xprt: transport
905  * @sk: socket
906  * @skb: skbuff
907  *
908  * Currently this assumes we can read the whole reply in a single gulp.
909  */
910 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
911 		struct sock *sk,
912 		struct sk_buff *skb)
913 {
914 	struct rpc_task *task;
915 	struct rpc_rqst *rovr;
916 	int repsize, copied;
917 	u32 _xid;
918 	__be32 *xp;
919 
920 	repsize = skb->len - sizeof(rpc_fraghdr);
921 	if (repsize < 4) {
922 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
923 		return;
924 	}
925 
926 	/* Copy the XID from the skb... */
927 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
928 	if (xp == NULL)
929 		return;
930 
931 	/* Look up and lock the request corresponding to the given XID */
932 	spin_lock_bh(&xprt->transport_lock);
933 	rovr = xprt_lookup_rqst(xprt, *xp);
934 	if (!rovr)
935 		goto out_unlock;
936 	task = rovr->rq_task;
937 
938 	copied = rovr->rq_private_buf.buflen;
939 	if (copied > repsize)
940 		copied = repsize;
941 
942 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
943 		dprintk("RPC:       sk_buff copy failed\n");
944 		goto out_unlock;
945 	}
946 
947 	xprt_complete_rqst(task, copied);
948 
949  out_unlock:
950 	spin_unlock_bh(&xprt->transport_lock);
951 }
952 
953 static void xs_local_data_receive(struct sock_xprt *transport)
954 {
955 	struct sk_buff *skb;
956 	struct sock *sk;
957 	int err;
958 
959 	mutex_lock(&transport->recv_mutex);
960 	sk = transport->inet;
961 	if (sk == NULL)
962 		goto out;
963 	for (;;) {
964 		skb = skb_recv_datagram(sk, 0, 1, &err);
965 		if (skb == NULL)
966 			break;
967 		xs_local_data_read_skb(&transport->xprt, sk, skb);
968 		skb_free_datagram(sk, skb);
969 	}
970 out:
971 	mutex_unlock(&transport->recv_mutex);
972 }
973 
974 static void xs_local_data_receive_workfn(struct work_struct *work)
975 {
976 	struct sock_xprt *transport =
977 		container_of(work, struct sock_xprt, recv_worker);
978 	xs_local_data_receive(transport);
979 }
980 
981 /**
982  * xs_udp_data_read_skb - receive callback for UDP sockets
983  * @xprt: transport
984  * @sk: socket
985  * @skb: skbuff
986  *
987  */
988 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
989 		struct sock *sk,
990 		struct sk_buff *skb)
991 {
992 	struct rpc_task *task;
993 	struct rpc_rqst *rovr;
994 	int repsize, copied;
995 	u32 _xid;
996 	__be32 *xp;
997 
998 	repsize = skb->len - sizeof(struct udphdr);
999 	if (repsize < 4) {
1000 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1001 		return;
1002 	}
1003 
1004 	/* Copy the XID from the skb... */
1005 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
1006 				sizeof(_xid), &_xid);
1007 	if (xp == NULL)
1008 		return;
1009 
1010 	/* Look up and lock the request corresponding to the given XID */
1011 	spin_lock_bh(&xprt->transport_lock);
1012 	rovr = xprt_lookup_rqst(xprt, *xp);
1013 	if (!rovr)
1014 		goto out_unlock;
1015 	task = rovr->rq_task;
1016 
1017 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1018 		copied = repsize;
1019 
1020 	/* Suck it into the iovec, verify checksum if not done by hw. */
1021 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1022 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1023 		goto out_unlock;
1024 	}
1025 
1026 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1027 
1028 	xprt_adjust_cwnd(xprt, task, copied);
1029 	xprt_complete_rqst(task, copied);
1030 
1031  out_unlock:
1032 	spin_unlock_bh(&xprt->transport_lock);
1033 }
1034 
1035 static void xs_udp_data_receive(struct sock_xprt *transport)
1036 {
1037 	struct sk_buff *skb;
1038 	struct sock *sk;
1039 	int err;
1040 
1041 	mutex_lock(&transport->recv_mutex);
1042 	sk = transport->inet;
1043 	if (sk == NULL)
1044 		goto out;
1045 	for (;;) {
1046 		skb = skb_recv_datagram(sk, 0, 1, &err);
1047 		if (skb == NULL)
1048 			break;
1049 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1050 		skb_free_datagram(sk, skb);
1051 	}
1052 out:
1053 	mutex_unlock(&transport->recv_mutex);
1054 }
1055 
1056 static void xs_udp_data_receive_workfn(struct work_struct *work)
1057 {
1058 	struct sock_xprt *transport =
1059 		container_of(work, struct sock_xprt, recv_worker);
1060 	xs_udp_data_receive(transport);
1061 }
1062 
1063 /**
1064  * xs_data_ready - "data ready" callback for UDP sockets
1065  * @sk: socket with data to read
1066  *
1067  */
1068 static void xs_data_ready(struct sock *sk)
1069 {
1070 	struct rpc_xprt *xprt;
1071 
1072 	read_lock_bh(&sk->sk_callback_lock);
1073 	dprintk("RPC:       xs_data_ready...\n");
1074 	xprt = xprt_from_sock(sk);
1075 	if (xprt != NULL) {
1076 		struct sock_xprt *transport = container_of(xprt,
1077 				struct sock_xprt, xprt);
1078 		queue_work(rpciod_workqueue, &transport->recv_worker);
1079 	}
1080 	read_unlock_bh(&sk->sk_callback_lock);
1081 }
1082 
1083 /*
1084  * Helper function to force a TCP close if the server is sending
1085  * junk and/or it has put us in CLOSE_WAIT
1086  */
1087 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1088 {
1089 	xprt_force_disconnect(xprt);
1090 }
1091 
1092 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1093 {
1094 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1095 	size_t len, used;
1096 	char *p;
1097 
1098 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1099 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1100 	used = xdr_skb_read_bits(desc, p, len);
1101 	transport->tcp_offset += used;
1102 	if (used != len)
1103 		return;
1104 
1105 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1106 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1107 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1108 	else
1109 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1110 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1111 
1112 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1113 	transport->tcp_offset = 0;
1114 
1115 	/* Sanity check of the record length */
1116 	if (unlikely(transport->tcp_reclen < 8)) {
1117 		dprintk("RPC:       invalid TCP record fragment length\n");
1118 		xs_tcp_force_close(xprt);
1119 		return;
1120 	}
1121 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1122 			transport->tcp_reclen);
1123 }
1124 
1125 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1126 {
1127 	if (transport->tcp_offset == transport->tcp_reclen) {
1128 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1129 		transport->tcp_offset = 0;
1130 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1131 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1132 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1133 			transport->tcp_copied = 0;
1134 		}
1135 	}
1136 }
1137 
1138 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1139 {
1140 	size_t len, used;
1141 	char *p;
1142 
1143 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1144 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1145 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1146 	used = xdr_skb_read_bits(desc, p, len);
1147 	transport->tcp_offset += used;
1148 	if (used != len)
1149 		return;
1150 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1151 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1152 	transport->tcp_copied = 4;
1153 	dprintk("RPC:       reading %s XID %08x\n",
1154 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1155 							      : "request with",
1156 			ntohl(transport->tcp_xid));
1157 	xs_tcp_check_fraghdr(transport);
1158 }
1159 
1160 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1161 				       struct xdr_skb_reader *desc)
1162 {
1163 	size_t len, used;
1164 	u32 offset;
1165 	char *p;
1166 
1167 	/*
1168 	 * We want transport->tcp_offset to be 8 at the end of this routine
1169 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1170 	 * When this function is called for the first time,
1171 	 * transport->tcp_offset is 4 (after having already read the xid).
1172 	 */
1173 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1174 	len = sizeof(transport->tcp_calldir) - offset;
1175 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1176 	p = ((char *) &transport->tcp_calldir) + offset;
1177 	used = xdr_skb_read_bits(desc, p, len);
1178 	transport->tcp_offset += used;
1179 	if (used != len)
1180 		return;
1181 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1182 	/*
1183 	 * We don't yet have the XDR buffer, so we will write the calldir
1184 	 * out after we get the buffer from the 'struct rpc_rqst'
1185 	 */
1186 	switch (ntohl(transport->tcp_calldir)) {
1187 	case RPC_REPLY:
1188 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1189 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1190 		transport->tcp_flags |= TCP_RPC_REPLY;
1191 		break;
1192 	case RPC_CALL:
1193 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1194 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1195 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1196 		break;
1197 	default:
1198 		dprintk("RPC:       invalid request message type\n");
1199 		xs_tcp_force_close(&transport->xprt);
1200 	}
1201 	xs_tcp_check_fraghdr(transport);
1202 }
1203 
1204 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1205 				     struct xdr_skb_reader *desc,
1206 				     struct rpc_rqst *req)
1207 {
1208 	struct sock_xprt *transport =
1209 				container_of(xprt, struct sock_xprt, xprt);
1210 	struct xdr_buf *rcvbuf;
1211 	size_t len;
1212 	ssize_t r;
1213 
1214 	rcvbuf = &req->rq_private_buf;
1215 
1216 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1217 		/*
1218 		 * Save the RPC direction in the XDR buffer
1219 		 */
1220 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1221 			&transport->tcp_calldir,
1222 			sizeof(transport->tcp_calldir));
1223 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1224 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1225 	}
1226 
1227 	len = desc->count;
1228 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1229 		struct xdr_skb_reader my_desc;
1230 
1231 		len = transport->tcp_reclen - transport->tcp_offset;
1232 		memcpy(&my_desc, desc, sizeof(my_desc));
1233 		my_desc.count = len;
1234 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1235 					  &my_desc, xdr_skb_read_bits);
1236 		desc->count -= r;
1237 		desc->offset += r;
1238 	} else
1239 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1240 					  desc, xdr_skb_read_bits);
1241 
1242 	if (r > 0) {
1243 		transport->tcp_copied += r;
1244 		transport->tcp_offset += r;
1245 	}
1246 	if (r != len) {
1247 		/* Error when copying to the receive buffer,
1248 		 * usually because we weren't able to allocate
1249 		 * additional buffer pages. All we can do now
1250 		 * is turn off TCP_RCV_COPY_DATA, so the request
1251 		 * will not receive any additional updates,
1252 		 * and time out.
1253 		 * Any remaining data from this record will
1254 		 * be discarded.
1255 		 */
1256 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1257 		dprintk("RPC:       XID %08x truncated request\n",
1258 				ntohl(transport->tcp_xid));
1259 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1260 				"tcp_offset = %u, tcp_reclen = %u\n",
1261 				xprt, transport->tcp_copied,
1262 				transport->tcp_offset, transport->tcp_reclen);
1263 		return;
1264 	}
1265 
1266 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1267 			ntohl(transport->tcp_xid), r);
1268 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1269 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1270 			transport->tcp_offset, transport->tcp_reclen);
1271 
1272 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1273 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1274 	else if (transport->tcp_offset == transport->tcp_reclen) {
1275 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1276 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1277 	}
1278 }
1279 
1280 /*
1281  * Finds the request corresponding to the RPC xid and invokes the common
1282  * tcp read code to read the data.
1283  */
1284 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1285 				    struct xdr_skb_reader *desc)
1286 {
1287 	struct sock_xprt *transport =
1288 				container_of(xprt, struct sock_xprt, xprt);
1289 	struct rpc_rqst *req;
1290 
1291 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1292 
1293 	/* Find and lock the request corresponding to this xid */
1294 	spin_lock_bh(&xprt->transport_lock);
1295 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1296 	if (!req) {
1297 		dprintk("RPC:       XID %08x request not found!\n",
1298 				ntohl(transport->tcp_xid));
1299 		spin_unlock_bh(&xprt->transport_lock);
1300 		return -1;
1301 	}
1302 
1303 	xs_tcp_read_common(xprt, desc, req);
1304 
1305 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1306 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1307 
1308 	spin_unlock_bh(&xprt->transport_lock);
1309 	return 0;
1310 }
1311 
1312 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1313 /*
1314  * Obtains an rpc_rqst previously allocated and invokes the common
1315  * tcp read code to read the data.  The result is placed in the callback
1316  * queue.
1317  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1318  * connection and return -1.
1319  */
1320 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1321 				       struct xdr_skb_reader *desc)
1322 {
1323 	struct sock_xprt *transport =
1324 				container_of(xprt, struct sock_xprt, xprt);
1325 	struct rpc_rqst *req;
1326 
1327 	/* Look up and lock the request corresponding to the given XID */
1328 	spin_lock_bh(&xprt->transport_lock);
1329 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1330 	if (req == NULL) {
1331 		spin_unlock_bh(&xprt->transport_lock);
1332 		printk(KERN_WARNING "Callback slot table overflowed\n");
1333 		xprt_force_disconnect(xprt);
1334 		return -1;
1335 	}
1336 
1337 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1338 	xs_tcp_read_common(xprt, desc, req);
1339 
1340 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1341 		xprt_complete_bc_request(req, transport->tcp_copied);
1342 	spin_unlock_bh(&xprt->transport_lock);
1343 
1344 	return 0;
1345 }
1346 
1347 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1348 					struct xdr_skb_reader *desc)
1349 {
1350 	struct sock_xprt *transport =
1351 				container_of(xprt, struct sock_xprt, xprt);
1352 
1353 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1354 		xs_tcp_read_reply(xprt, desc) :
1355 		xs_tcp_read_callback(xprt, desc);
1356 }
1357 
1358 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1359 {
1360 	int ret;
1361 
1362 	ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1363 			      SVC_SOCK_ANONYMOUS);
1364 	if (ret < 0)
1365 		return ret;
1366 	return 0;
1367 }
1368 #else
1369 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1370 					struct xdr_skb_reader *desc)
1371 {
1372 	return xs_tcp_read_reply(xprt, desc);
1373 }
1374 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1375 
1376 /*
1377  * Read data off the transport.  This can be either an RPC_CALL or an
1378  * RPC_REPLY.  Relay the processing to helper functions.
1379  */
1380 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1381 				    struct xdr_skb_reader *desc)
1382 {
1383 	struct sock_xprt *transport =
1384 				container_of(xprt, struct sock_xprt, xprt);
1385 
1386 	if (_xs_tcp_read_data(xprt, desc) == 0)
1387 		xs_tcp_check_fraghdr(transport);
1388 	else {
1389 		/*
1390 		 * The transport_lock protects the request handling.
1391 		 * There's no need to hold it to update the tcp_flags.
1392 		 */
1393 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1394 	}
1395 }
1396 
1397 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1398 {
1399 	size_t len;
1400 
1401 	len = transport->tcp_reclen - transport->tcp_offset;
1402 	if (len > desc->count)
1403 		len = desc->count;
1404 	desc->count -= len;
1405 	desc->offset += len;
1406 	transport->tcp_offset += len;
1407 	dprintk("RPC:       discarded %Zu bytes\n", len);
1408 	xs_tcp_check_fraghdr(transport);
1409 }
1410 
1411 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1412 {
1413 	struct rpc_xprt *xprt = rd_desc->arg.data;
1414 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1415 	struct xdr_skb_reader desc = {
1416 		.skb	= skb,
1417 		.offset	= offset,
1418 		.count	= len,
1419 	};
1420 
1421 	dprintk("RPC:       xs_tcp_data_recv started\n");
1422 	do {
1423 		trace_xs_tcp_data_recv(transport);
1424 		/* Read in a new fragment marker if necessary */
1425 		/* Can we ever really expect to get completely empty fragments? */
1426 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1427 			xs_tcp_read_fraghdr(xprt, &desc);
1428 			continue;
1429 		}
1430 		/* Read in the xid if necessary */
1431 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1432 			xs_tcp_read_xid(transport, &desc);
1433 			continue;
1434 		}
1435 		/* Read in the call/reply flag */
1436 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1437 			xs_tcp_read_calldir(transport, &desc);
1438 			continue;
1439 		}
1440 		/* Read in the request data */
1441 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1442 			xs_tcp_read_data(xprt, &desc);
1443 			continue;
1444 		}
1445 		/* Skip over any trailing bytes on short reads */
1446 		xs_tcp_read_discard(transport, &desc);
1447 	} while (desc.count);
1448 	trace_xs_tcp_data_recv(transport);
1449 	dprintk("RPC:       xs_tcp_data_recv done\n");
1450 	return len - desc.count;
1451 }
1452 
1453 static void xs_tcp_data_receive(struct sock_xprt *transport)
1454 {
1455 	struct rpc_xprt *xprt = &transport->xprt;
1456 	struct sock *sk;
1457 	read_descriptor_t rd_desc = {
1458 		.count = 2*1024*1024,
1459 		.arg.data = xprt,
1460 	};
1461 	unsigned long total = 0;
1462 	int read = 0;
1463 
1464 	mutex_lock(&transport->recv_mutex);
1465 	sk = transport->inet;
1466 	if (sk == NULL)
1467 		goto out;
1468 
1469 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1470 	for (;;) {
1471 		lock_sock(sk);
1472 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1473 		release_sock(sk);
1474 		if (read <= 0)
1475 			break;
1476 		total += read;
1477 		rd_desc.count = 65536;
1478 	}
1479 out:
1480 	mutex_unlock(&transport->recv_mutex);
1481 	trace_xs_tcp_data_ready(xprt, read, total);
1482 }
1483 
1484 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1485 {
1486 	struct sock_xprt *transport =
1487 		container_of(work, struct sock_xprt, recv_worker);
1488 	xs_tcp_data_receive(transport);
1489 }
1490 
1491 /**
1492  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1493  * @sk: socket with data to read
1494  *
1495  */
1496 static void xs_tcp_data_ready(struct sock *sk)
1497 {
1498 	struct sock_xprt *transport;
1499 	struct rpc_xprt *xprt;
1500 
1501 	dprintk("RPC:       xs_tcp_data_ready...\n");
1502 
1503 	read_lock_bh(&sk->sk_callback_lock);
1504 	if (!(xprt = xprt_from_sock(sk)))
1505 		goto out;
1506 	transport = container_of(xprt, struct sock_xprt, xprt);
1507 
1508 	/* Any data means we had a useful conversation, so
1509 	 * the we don't need to delay the next reconnect
1510 	 */
1511 	if (xprt->reestablish_timeout)
1512 		xprt->reestablish_timeout = 0;
1513 	queue_work(rpciod_workqueue, &transport->recv_worker);
1514 
1515 out:
1516 	read_unlock_bh(&sk->sk_callback_lock);
1517 }
1518 
1519 /**
1520  * xs_tcp_state_change - callback to handle TCP socket state changes
1521  * @sk: socket whose state has changed
1522  *
1523  */
1524 static void xs_tcp_state_change(struct sock *sk)
1525 {
1526 	struct rpc_xprt *xprt;
1527 	struct sock_xprt *transport;
1528 
1529 	read_lock_bh(&sk->sk_callback_lock);
1530 	if (!(xprt = xprt_from_sock(sk)))
1531 		goto out;
1532 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1533 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1534 			sk->sk_state, xprt_connected(xprt),
1535 			sock_flag(sk, SOCK_DEAD),
1536 			sock_flag(sk, SOCK_ZAPPED),
1537 			sk->sk_shutdown);
1538 
1539 	transport = container_of(xprt, struct sock_xprt, xprt);
1540 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1541 	switch (sk->sk_state) {
1542 	case TCP_ESTABLISHED:
1543 		spin_lock(&xprt->transport_lock);
1544 		if (!xprt_test_and_set_connected(xprt)) {
1545 
1546 			/* Reset TCP record info */
1547 			transport->tcp_offset = 0;
1548 			transport->tcp_reclen = 0;
1549 			transport->tcp_copied = 0;
1550 			transport->tcp_flags =
1551 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1552 			xprt->connect_cookie++;
1553 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1554 			xprt_clear_connecting(xprt);
1555 
1556 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1557 		}
1558 		spin_unlock(&xprt->transport_lock);
1559 		break;
1560 	case TCP_FIN_WAIT1:
1561 		/* The client initiated a shutdown of the socket */
1562 		xprt->connect_cookie++;
1563 		xprt->reestablish_timeout = 0;
1564 		set_bit(XPRT_CLOSING, &xprt->state);
1565 		smp_mb__before_atomic();
1566 		clear_bit(XPRT_CONNECTED, &xprt->state);
1567 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1568 		smp_mb__after_atomic();
1569 		break;
1570 	case TCP_CLOSE_WAIT:
1571 		/* The server initiated a shutdown of the socket */
1572 		xprt->connect_cookie++;
1573 		clear_bit(XPRT_CONNECTED, &xprt->state);
1574 		xs_tcp_force_close(xprt);
1575 	case TCP_CLOSING:
1576 		/*
1577 		 * If the server closed down the connection, make sure that
1578 		 * we back off before reconnecting
1579 		 */
1580 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1581 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1582 		break;
1583 	case TCP_LAST_ACK:
1584 		set_bit(XPRT_CLOSING, &xprt->state);
1585 		smp_mb__before_atomic();
1586 		clear_bit(XPRT_CONNECTED, &xprt->state);
1587 		smp_mb__after_atomic();
1588 		break;
1589 	case TCP_CLOSE:
1590 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1591 					&transport->sock_state))
1592 			xprt_clear_connecting(xprt);
1593 		xs_sock_mark_closed(xprt);
1594 	}
1595  out:
1596 	read_unlock_bh(&sk->sk_callback_lock);
1597 }
1598 
1599 static void xs_write_space(struct sock *sk)
1600 {
1601 	struct socket_wq *wq;
1602 	struct rpc_xprt *xprt;
1603 
1604 	if (!sk->sk_socket)
1605 		return;
1606 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1607 
1608 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1609 		return;
1610 	rcu_read_lock();
1611 	wq = rcu_dereference(sk->sk_wq);
1612 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1613 		goto out;
1614 
1615 	xprt_write_space(xprt);
1616 out:
1617 	rcu_read_unlock();
1618 }
1619 
1620 /**
1621  * xs_udp_write_space - callback invoked when socket buffer space
1622  *                             becomes available
1623  * @sk: socket whose state has changed
1624  *
1625  * Called when more output buffer space is available for this socket.
1626  * We try not to wake our writers until they can make "significant"
1627  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1628  * with a bunch of small requests.
1629  */
1630 static void xs_udp_write_space(struct sock *sk)
1631 {
1632 	read_lock_bh(&sk->sk_callback_lock);
1633 
1634 	/* from net/core/sock.c:sock_def_write_space */
1635 	if (sock_writeable(sk))
1636 		xs_write_space(sk);
1637 
1638 	read_unlock_bh(&sk->sk_callback_lock);
1639 }
1640 
1641 /**
1642  * xs_tcp_write_space - callback invoked when socket buffer space
1643  *                             becomes available
1644  * @sk: socket whose state has changed
1645  *
1646  * Called when more output buffer space is available for this socket.
1647  * We try not to wake our writers until they can make "significant"
1648  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1649  * with a bunch of small requests.
1650  */
1651 static void xs_tcp_write_space(struct sock *sk)
1652 {
1653 	read_lock_bh(&sk->sk_callback_lock);
1654 
1655 	/* from net/core/stream.c:sk_stream_write_space */
1656 	if (sk_stream_is_writeable(sk))
1657 		xs_write_space(sk);
1658 
1659 	read_unlock_bh(&sk->sk_callback_lock);
1660 }
1661 
1662 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1663 {
1664 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1665 	struct sock *sk = transport->inet;
1666 
1667 	if (transport->rcvsize) {
1668 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1669 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1670 	}
1671 	if (transport->sndsize) {
1672 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1673 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1674 		sk->sk_write_space(sk);
1675 	}
1676 }
1677 
1678 /**
1679  * xs_udp_set_buffer_size - set send and receive limits
1680  * @xprt: generic transport
1681  * @sndsize: requested size of send buffer, in bytes
1682  * @rcvsize: requested size of receive buffer, in bytes
1683  *
1684  * Set socket send and receive buffer size limits.
1685  */
1686 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1687 {
1688 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1689 
1690 	transport->sndsize = 0;
1691 	if (sndsize)
1692 		transport->sndsize = sndsize + 1024;
1693 	transport->rcvsize = 0;
1694 	if (rcvsize)
1695 		transport->rcvsize = rcvsize + 1024;
1696 
1697 	xs_udp_do_set_buffer_size(xprt);
1698 }
1699 
1700 /**
1701  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1702  * @task: task that timed out
1703  *
1704  * Adjust the congestion window after a retransmit timeout has occurred.
1705  */
1706 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1707 {
1708 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1709 }
1710 
1711 static unsigned short xs_get_random_port(void)
1712 {
1713 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1714 	unsigned short rand = (unsigned short) prandom_u32() % range;
1715 	return rand + xprt_min_resvport;
1716 }
1717 
1718 /**
1719  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1720  * @sock: socket
1721  *
1722  * Note that this function has to be called on all sockets that share the
1723  * same port, and it must be called before binding.
1724  */
1725 static void xs_sock_set_reuseport(struct socket *sock)
1726 {
1727 	int opt = 1;
1728 
1729 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1730 			(char *)&opt, sizeof(opt));
1731 }
1732 
1733 static unsigned short xs_sock_getport(struct socket *sock)
1734 {
1735 	struct sockaddr_storage buf;
1736 	int buflen;
1737 	unsigned short port = 0;
1738 
1739 	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1740 		goto out;
1741 	switch (buf.ss_family) {
1742 	case AF_INET6:
1743 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1744 		break;
1745 	case AF_INET:
1746 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1747 	}
1748 out:
1749 	return port;
1750 }
1751 
1752 /**
1753  * xs_set_port - reset the port number in the remote endpoint address
1754  * @xprt: generic transport
1755  * @port: new port number
1756  *
1757  */
1758 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1759 {
1760 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1761 
1762 	rpc_set_port(xs_addr(xprt), port);
1763 	xs_update_peer_port(xprt);
1764 }
1765 
1766 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1767 {
1768 	if (transport->srcport == 0)
1769 		transport->srcport = xs_sock_getport(sock);
1770 }
1771 
1772 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1773 {
1774 	unsigned short port = transport->srcport;
1775 
1776 	if (port == 0 && transport->xprt.resvport)
1777 		port = xs_get_random_port();
1778 	return port;
1779 }
1780 
1781 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1782 {
1783 	if (transport->srcport != 0)
1784 		transport->srcport = 0;
1785 	if (!transport->xprt.resvport)
1786 		return 0;
1787 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1788 		return xprt_max_resvport;
1789 	return --port;
1790 }
1791 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1792 {
1793 	struct sockaddr_storage myaddr;
1794 	int err, nloop = 0;
1795 	unsigned short port = xs_get_srcport(transport);
1796 	unsigned short last;
1797 
1798 	/*
1799 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1800 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1801 	 * port selection happen implicitly when the socket is used
1802 	 * (for example at connect time).
1803 	 *
1804 	 * This ensures that we can continue to establish TCP
1805 	 * connections even when all local ephemeral ports are already
1806 	 * a part of some TCP connection.  This makes no difference
1807 	 * for UDP sockets, but also doens't harm them.
1808 	 *
1809 	 * If we're asking for any reserved port (i.e. port == 0 &&
1810 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1811 	 * ensure that port is non-zero and we will bind as needed.
1812 	 */
1813 	if (port == 0)
1814 		return 0;
1815 
1816 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1817 	do {
1818 		rpc_set_port((struct sockaddr *)&myaddr, port);
1819 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1820 				transport->xprt.addrlen);
1821 		if (err == 0) {
1822 			transport->srcport = port;
1823 			break;
1824 		}
1825 		last = port;
1826 		port = xs_next_srcport(transport, port);
1827 		if (port > last)
1828 			nloop++;
1829 	} while (err == -EADDRINUSE && nloop != 2);
1830 
1831 	if (myaddr.ss_family == AF_INET)
1832 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1833 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1834 				port, err ? "failed" : "ok", err);
1835 	else
1836 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1837 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1838 				port, err ? "failed" : "ok", err);
1839 	return err;
1840 }
1841 
1842 /*
1843  * We don't support autobind on AF_LOCAL sockets
1844  */
1845 static void xs_local_rpcbind(struct rpc_task *task)
1846 {
1847 	xprt_set_bound(task->tk_xprt);
1848 }
1849 
1850 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1851 {
1852 }
1853 
1854 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1855 static struct lock_class_key xs_key[2];
1856 static struct lock_class_key xs_slock_key[2];
1857 
1858 static inline void xs_reclassify_socketu(struct socket *sock)
1859 {
1860 	struct sock *sk = sock->sk;
1861 
1862 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1863 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1864 }
1865 
1866 static inline void xs_reclassify_socket4(struct socket *sock)
1867 {
1868 	struct sock *sk = sock->sk;
1869 
1870 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1871 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1872 }
1873 
1874 static inline void xs_reclassify_socket6(struct socket *sock)
1875 {
1876 	struct sock *sk = sock->sk;
1877 
1878 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1879 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1880 }
1881 
1882 static inline void xs_reclassify_socket(int family, struct socket *sock)
1883 {
1884 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1885 	if (sock_owned_by_user(sock->sk))
1886 		return;
1887 
1888 	switch (family) {
1889 	case AF_LOCAL:
1890 		xs_reclassify_socketu(sock);
1891 		break;
1892 	case AF_INET:
1893 		xs_reclassify_socket4(sock);
1894 		break;
1895 	case AF_INET6:
1896 		xs_reclassify_socket6(sock);
1897 		break;
1898 	}
1899 }
1900 #else
1901 static inline void xs_reclassify_socket(int family, struct socket *sock)
1902 {
1903 }
1904 #endif
1905 
1906 static void xs_dummy_setup_socket(struct work_struct *work)
1907 {
1908 }
1909 
1910 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1911 		struct sock_xprt *transport, int family, int type,
1912 		int protocol, bool reuseport)
1913 {
1914 	struct socket *sock;
1915 	int err;
1916 
1917 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1918 	if (err < 0) {
1919 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1920 				protocol, -err);
1921 		goto out;
1922 	}
1923 	xs_reclassify_socket(family, sock);
1924 
1925 	if (reuseport)
1926 		xs_sock_set_reuseport(sock);
1927 
1928 	err = xs_bind(transport, sock);
1929 	if (err) {
1930 		sock_release(sock);
1931 		goto out;
1932 	}
1933 
1934 	return sock;
1935 out:
1936 	return ERR_PTR(err);
1937 }
1938 
1939 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1940 				      struct socket *sock)
1941 {
1942 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1943 									xprt);
1944 
1945 	if (!transport->inet) {
1946 		struct sock *sk = sock->sk;
1947 
1948 		write_lock_bh(&sk->sk_callback_lock);
1949 
1950 		xs_save_old_callbacks(transport, sk);
1951 
1952 		sk->sk_user_data = xprt;
1953 		sk->sk_data_ready = xs_data_ready;
1954 		sk->sk_write_space = xs_udp_write_space;
1955 		sk->sk_error_report = xs_error_report;
1956 		sk->sk_allocation = GFP_NOIO;
1957 
1958 		xprt_clear_connected(xprt);
1959 
1960 		/* Reset to new socket */
1961 		transport->sock = sock;
1962 		transport->inet = sk;
1963 
1964 		write_unlock_bh(&sk->sk_callback_lock);
1965 	}
1966 
1967 	/* Tell the socket layer to start connecting... */
1968 	xprt->stat.connect_count++;
1969 	xprt->stat.connect_start = jiffies;
1970 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1971 }
1972 
1973 /**
1974  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1975  * @transport: socket transport to connect
1976  */
1977 static int xs_local_setup_socket(struct sock_xprt *transport)
1978 {
1979 	struct rpc_xprt *xprt = &transport->xprt;
1980 	struct socket *sock;
1981 	int status = -EIO;
1982 
1983 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1984 					SOCK_STREAM, 0, &sock, 1);
1985 	if (status < 0) {
1986 		dprintk("RPC:       can't create AF_LOCAL "
1987 			"transport socket (%d).\n", -status);
1988 		goto out;
1989 	}
1990 	xs_reclassify_socket(AF_LOCAL, sock);
1991 
1992 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1993 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1994 
1995 	status = xs_local_finish_connecting(xprt, sock);
1996 	trace_rpc_socket_connect(xprt, sock, status);
1997 	switch (status) {
1998 	case 0:
1999 		dprintk("RPC:       xprt %p connected to %s\n",
2000 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2001 		xprt_set_connected(xprt);
2002 	case -ENOBUFS:
2003 		break;
2004 	case -ENOENT:
2005 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
2006 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2007 		break;
2008 	case -ECONNREFUSED:
2009 		dprintk("RPC:       xprt %p: connection refused for %s\n",
2010 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2011 		break;
2012 	default:
2013 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2014 				__func__, -status,
2015 				xprt->address_strings[RPC_DISPLAY_ADDR]);
2016 	}
2017 
2018 out:
2019 	xprt_clear_connecting(xprt);
2020 	xprt_wake_pending_tasks(xprt, status);
2021 	return status;
2022 }
2023 
2024 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2025 {
2026 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2027 	int ret;
2028 
2029 	 if (RPC_IS_ASYNC(task)) {
2030 		/*
2031 		 * We want the AF_LOCAL connect to be resolved in the
2032 		 * filesystem namespace of the process making the rpc
2033 		 * call.  Thus we connect synchronously.
2034 		 *
2035 		 * If we want to support asynchronous AF_LOCAL calls,
2036 		 * we'll need to figure out how to pass a namespace to
2037 		 * connect.
2038 		 */
2039 		rpc_exit(task, -ENOTCONN);
2040 		return;
2041 	}
2042 	ret = xs_local_setup_socket(transport);
2043 	if (ret && !RPC_IS_SOFTCONN(task))
2044 		msleep_interruptible(15000);
2045 }
2046 
2047 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2048 /*
2049  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2050  * know that we have exclusive access to the socket), to guard against
2051  * races with xs_reset_transport.
2052  */
2053 static void xs_set_memalloc(struct rpc_xprt *xprt)
2054 {
2055 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2056 			xprt);
2057 
2058 	/*
2059 	 * If there's no sock, then we have nothing to set. The
2060 	 * reconnecting process will get it for us.
2061 	 */
2062 	if (!transport->inet)
2063 		return;
2064 	if (atomic_read(&xprt->swapper))
2065 		sk_set_memalloc(transport->inet);
2066 }
2067 
2068 /**
2069  * xs_enable_swap - Tag this transport as being used for swap.
2070  * @xprt: transport to tag
2071  *
2072  * Take a reference to this transport on behalf of the rpc_clnt, and
2073  * optionally mark it for swapping if it wasn't already.
2074  */
2075 static int
2076 xs_enable_swap(struct rpc_xprt *xprt)
2077 {
2078 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2079 
2080 	if (atomic_inc_return(&xprt->swapper) != 1)
2081 		return 0;
2082 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2083 		return -ERESTARTSYS;
2084 	if (xs->inet)
2085 		sk_set_memalloc(xs->inet);
2086 	xprt_release_xprt(xprt, NULL);
2087 	return 0;
2088 }
2089 
2090 /**
2091  * xs_disable_swap - Untag this transport as being used for swap.
2092  * @xprt: transport to tag
2093  *
2094  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2095  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2096  */
2097 static void
2098 xs_disable_swap(struct rpc_xprt *xprt)
2099 {
2100 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2101 
2102 	if (!atomic_dec_and_test(&xprt->swapper))
2103 		return;
2104 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2105 		return;
2106 	if (xs->inet)
2107 		sk_clear_memalloc(xs->inet);
2108 	xprt_release_xprt(xprt, NULL);
2109 }
2110 #else
2111 static void xs_set_memalloc(struct rpc_xprt *xprt)
2112 {
2113 }
2114 
2115 static int
2116 xs_enable_swap(struct rpc_xprt *xprt)
2117 {
2118 	return -EINVAL;
2119 }
2120 
2121 static void
2122 xs_disable_swap(struct rpc_xprt *xprt)
2123 {
2124 }
2125 #endif
2126 
2127 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2128 {
2129 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2130 
2131 	if (!transport->inet) {
2132 		struct sock *sk = sock->sk;
2133 
2134 		write_lock_bh(&sk->sk_callback_lock);
2135 
2136 		xs_save_old_callbacks(transport, sk);
2137 
2138 		sk->sk_user_data = xprt;
2139 		sk->sk_data_ready = xs_data_ready;
2140 		sk->sk_write_space = xs_udp_write_space;
2141 		sk->sk_allocation = GFP_NOIO;
2142 
2143 		xprt_set_connected(xprt);
2144 
2145 		/* Reset to new socket */
2146 		transport->sock = sock;
2147 		transport->inet = sk;
2148 
2149 		xs_set_memalloc(xprt);
2150 
2151 		write_unlock_bh(&sk->sk_callback_lock);
2152 	}
2153 	xs_udp_do_set_buffer_size(xprt);
2154 }
2155 
2156 static void xs_udp_setup_socket(struct work_struct *work)
2157 {
2158 	struct sock_xprt *transport =
2159 		container_of(work, struct sock_xprt, connect_worker.work);
2160 	struct rpc_xprt *xprt = &transport->xprt;
2161 	struct socket *sock = transport->sock;
2162 	int status = -EIO;
2163 
2164 	sock = xs_create_sock(xprt, transport,
2165 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2166 			IPPROTO_UDP, false);
2167 	if (IS_ERR(sock))
2168 		goto out;
2169 
2170 	dprintk("RPC:       worker connecting xprt %p via %s to "
2171 				"%s (port %s)\n", xprt,
2172 			xprt->address_strings[RPC_DISPLAY_PROTO],
2173 			xprt->address_strings[RPC_DISPLAY_ADDR],
2174 			xprt->address_strings[RPC_DISPLAY_PORT]);
2175 
2176 	xs_udp_finish_connecting(xprt, sock);
2177 	trace_rpc_socket_connect(xprt, sock, 0);
2178 	status = 0;
2179 out:
2180 	xprt_unlock_connect(xprt, transport);
2181 	xprt_clear_connecting(xprt);
2182 	xprt_wake_pending_tasks(xprt, status);
2183 }
2184 
2185 /**
2186  * xs_tcp_shutdown - gracefully shut down a TCP socket
2187  * @xprt: transport
2188  *
2189  * Initiates a graceful shutdown of the TCP socket by calling the
2190  * equivalent of shutdown(SHUT_RDWR);
2191  */
2192 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2193 {
2194 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2195 	struct socket *sock = transport->sock;
2196 
2197 	if (sock == NULL)
2198 		return;
2199 	if (xprt_connected(xprt)) {
2200 		kernel_sock_shutdown(sock, SHUT_RDWR);
2201 		trace_rpc_socket_shutdown(xprt, sock);
2202 	} else
2203 		xs_reset_transport(transport);
2204 }
2205 
2206 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2207 {
2208 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2209 	int ret = -ENOTCONN;
2210 
2211 	if (!transport->inet) {
2212 		struct sock *sk = sock->sk;
2213 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2214 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2215 		unsigned int opt_on = 1;
2216 		unsigned int timeo;
2217 
2218 		/* TCP Keepalive options */
2219 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2220 				(char *)&opt_on, sizeof(opt_on));
2221 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2222 				(char *)&keepidle, sizeof(keepidle));
2223 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2224 				(char *)&keepidle, sizeof(keepidle));
2225 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2226 				(char *)&keepcnt, sizeof(keepcnt));
2227 
2228 		/* TCP user timeout (see RFC5482) */
2229 		timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2230 			(xprt->timeout->to_retries + 1);
2231 		kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2232 				(char *)&timeo, sizeof(timeo));
2233 
2234 		write_lock_bh(&sk->sk_callback_lock);
2235 
2236 		xs_save_old_callbacks(transport, sk);
2237 
2238 		sk->sk_user_data = xprt;
2239 		sk->sk_data_ready = xs_tcp_data_ready;
2240 		sk->sk_state_change = xs_tcp_state_change;
2241 		sk->sk_write_space = xs_tcp_write_space;
2242 		sk->sk_error_report = xs_error_report;
2243 		sk->sk_allocation = GFP_NOIO;
2244 
2245 		/* socket options */
2246 		sock_reset_flag(sk, SOCK_LINGER);
2247 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2248 
2249 		xprt_clear_connected(xprt);
2250 
2251 		/* Reset to new socket */
2252 		transport->sock = sock;
2253 		transport->inet = sk;
2254 
2255 		write_unlock_bh(&sk->sk_callback_lock);
2256 	}
2257 
2258 	if (!xprt_bound(xprt))
2259 		goto out;
2260 
2261 	xs_set_memalloc(xprt);
2262 
2263 	/* Tell the socket layer to start connecting... */
2264 	xprt->stat.connect_count++;
2265 	xprt->stat.connect_start = jiffies;
2266 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2267 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2268 	switch (ret) {
2269 	case 0:
2270 		xs_set_srcport(transport, sock);
2271 	case -EINPROGRESS:
2272 		/* SYN_SENT! */
2273 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2274 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2275 	}
2276 out:
2277 	return ret;
2278 }
2279 
2280 /**
2281  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2282  *
2283  * Invoked by a work queue tasklet.
2284  */
2285 static void xs_tcp_setup_socket(struct work_struct *work)
2286 {
2287 	struct sock_xprt *transport =
2288 		container_of(work, struct sock_xprt, connect_worker.work);
2289 	struct socket *sock = transport->sock;
2290 	struct rpc_xprt *xprt = &transport->xprt;
2291 	int status = -EIO;
2292 
2293 	if (!sock) {
2294 		sock = xs_create_sock(xprt, transport,
2295 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2296 				IPPROTO_TCP, true);
2297 		if (IS_ERR(sock)) {
2298 			status = PTR_ERR(sock);
2299 			goto out;
2300 		}
2301 	}
2302 
2303 	dprintk("RPC:       worker connecting xprt %p via %s to "
2304 				"%s (port %s)\n", xprt,
2305 			xprt->address_strings[RPC_DISPLAY_PROTO],
2306 			xprt->address_strings[RPC_DISPLAY_ADDR],
2307 			xprt->address_strings[RPC_DISPLAY_PORT]);
2308 
2309 	status = xs_tcp_finish_connecting(xprt, sock);
2310 	trace_rpc_socket_connect(xprt, sock, status);
2311 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2312 			xprt, -status, xprt_connected(xprt),
2313 			sock->sk->sk_state);
2314 	switch (status) {
2315 	default:
2316 		printk("%s: connect returned unhandled error %d\n",
2317 			__func__, status);
2318 	case -EADDRNOTAVAIL:
2319 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2320 		 * and retry
2321 		 */
2322 		xs_tcp_force_close(xprt);
2323 		break;
2324 	case 0:
2325 	case -EINPROGRESS:
2326 	case -EALREADY:
2327 		xprt_unlock_connect(xprt, transport);
2328 		return;
2329 	case -EINVAL:
2330 		/* Happens, for instance, if the user specified a link
2331 		 * local IPv6 address without a scope-id.
2332 		 */
2333 	case -ECONNREFUSED:
2334 	case -ECONNRESET:
2335 	case -ENETUNREACH:
2336 	case -EADDRINUSE:
2337 	case -ENOBUFS:
2338 		/* retry with existing socket, after a delay */
2339 		xs_tcp_force_close(xprt);
2340 		goto out;
2341 	}
2342 	status = -EAGAIN;
2343 out:
2344 	xprt_unlock_connect(xprt, transport);
2345 	xprt_clear_connecting(xprt);
2346 	xprt_wake_pending_tasks(xprt, status);
2347 }
2348 
2349 /**
2350  * xs_connect - connect a socket to a remote endpoint
2351  * @xprt: pointer to transport structure
2352  * @task: address of RPC task that manages state of connect request
2353  *
2354  * TCP: If the remote end dropped the connection, delay reconnecting.
2355  *
2356  * UDP socket connects are synchronous, but we use a work queue anyway
2357  * to guarantee that even unprivileged user processes can set up a
2358  * socket on a privileged port.
2359  *
2360  * If a UDP socket connect fails, the delay behavior here prevents
2361  * retry floods (hard mounts).
2362  */
2363 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2364 {
2365 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2366 
2367 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2368 
2369 	if (transport->sock != NULL) {
2370 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2371 				"seconds\n",
2372 				xprt, xprt->reestablish_timeout / HZ);
2373 
2374 		/* Start by resetting any existing state */
2375 		xs_reset_transport(transport);
2376 
2377 		queue_delayed_work(rpciod_workqueue,
2378 				   &transport->connect_worker,
2379 				   xprt->reestablish_timeout);
2380 		xprt->reestablish_timeout <<= 1;
2381 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2382 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2383 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2384 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2385 	} else {
2386 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2387 		queue_delayed_work(rpciod_workqueue,
2388 				   &transport->connect_worker, 0);
2389 	}
2390 }
2391 
2392 /**
2393  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2394  * @xprt: rpc_xprt struct containing statistics
2395  * @seq: output file
2396  *
2397  */
2398 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2399 {
2400 	long idle_time = 0;
2401 
2402 	if (xprt_connected(xprt))
2403 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2404 
2405 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2406 			"%llu %llu %lu %llu %llu\n",
2407 			xprt->stat.bind_count,
2408 			xprt->stat.connect_count,
2409 			xprt->stat.connect_time,
2410 			idle_time,
2411 			xprt->stat.sends,
2412 			xprt->stat.recvs,
2413 			xprt->stat.bad_xids,
2414 			xprt->stat.req_u,
2415 			xprt->stat.bklog_u,
2416 			xprt->stat.max_slots,
2417 			xprt->stat.sending_u,
2418 			xprt->stat.pending_u);
2419 }
2420 
2421 /**
2422  * xs_udp_print_stats - display UDP socket-specifc stats
2423  * @xprt: rpc_xprt struct containing statistics
2424  * @seq: output file
2425  *
2426  */
2427 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2428 {
2429 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2430 
2431 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2432 			"%lu %llu %llu\n",
2433 			transport->srcport,
2434 			xprt->stat.bind_count,
2435 			xprt->stat.sends,
2436 			xprt->stat.recvs,
2437 			xprt->stat.bad_xids,
2438 			xprt->stat.req_u,
2439 			xprt->stat.bklog_u,
2440 			xprt->stat.max_slots,
2441 			xprt->stat.sending_u,
2442 			xprt->stat.pending_u);
2443 }
2444 
2445 /**
2446  * xs_tcp_print_stats - display TCP socket-specifc stats
2447  * @xprt: rpc_xprt struct containing statistics
2448  * @seq: output file
2449  *
2450  */
2451 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2452 {
2453 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2454 	long idle_time = 0;
2455 
2456 	if (xprt_connected(xprt))
2457 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2458 
2459 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2460 			"%llu %llu %lu %llu %llu\n",
2461 			transport->srcport,
2462 			xprt->stat.bind_count,
2463 			xprt->stat.connect_count,
2464 			xprt->stat.connect_time,
2465 			idle_time,
2466 			xprt->stat.sends,
2467 			xprt->stat.recvs,
2468 			xprt->stat.bad_xids,
2469 			xprt->stat.req_u,
2470 			xprt->stat.bklog_u,
2471 			xprt->stat.max_slots,
2472 			xprt->stat.sending_u,
2473 			xprt->stat.pending_u);
2474 }
2475 
2476 /*
2477  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2478  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2479  * to use the server side send routines.
2480  */
2481 static void *bc_malloc(struct rpc_task *task, size_t size)
2482 {
2483 	struct page *page;
2484 	struct rpc_buffer *buf;
2485 
2486 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2487 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2488 		return NULL;
2489 
2490 	page = alloc_page(GFP_KERNEL);
2491 	if (!page)
2492 		return NULL;
2493 
2494 	buf = page_address(page);
2495 	buf->len = PAGE_SIZE;
2496 
2497 	return buf->data;
2498 }
2499 
2500 /*
2501  * Free the space allocated in the bc_alloc routine
2502  */
2503 static void bc_free(void *buffer)
2504 {
2505 	struct rpc_buffer *buf;
2506 
2507 	if (!buffer)
2508 		return;
2509 
2510 	buf = container_of(buffer, struct rpc_buffer, data);
2511 	free_page((unsigned long)buf);
2512 }
2513 
2514 /*
2515  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2516  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2517  */
2518 static int bc_sendto(struct rpc_rqst *req)
2519 {
2520 	int len;
2521 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2522 	struct rpc_xprt *xprt = req->rq_xprt;
2523 	struct sock_xprt *transport =
2524 				container_of(xprt, struct sock_xprt, xprt);
2525 	struct socket *sock = transport->sock;
2526 	unsigned long headoff;
2527 	unsigned long tailoff;
2528 
2529 	xs_encode_stream_record_marker(xbufp);
2530 
2531 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2532 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2533 	len = svc_send_common(sock, xbufp,
2534 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2535 			      xbufp->tail[0].iov_base, tailoff);
2536 
2537 	if (len != xbufp->len) {
2538 		printk(KERN_NOTICE "Error sending entire callback!\n");
2539 		len = -EAGAIN;
2540 	}
2541 
2542 	return len;
2543 }
2544 
2545 /*
2546  * The send routine. Borrows from svc_send
2547  */
2548 static int bc_send_request(struct rpc_task *task)
2549 {
2550 	struct rpc_rqst *req = task->tk_rqstp;
2551 	struct svc_xprt	*xprt;
2552 	int len;
2553 
2554 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2555 	/*
2556 	 * Get the server socket associated with this callback xprt
2557 	 */
2558 	xprt = req->rq_xprt->bc_xprt;
2559 
2560 	/*
2561 	 * Grab the mutex to serialize data as the connection is shared
2562 	 * with the fore channel
2563 	 */
2564 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2565 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2566 		if (!mutex_trylock(&xprt->xpt_mutex))
2567 			return -EAGAIN;
2568 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2569 	}
2570 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2571 		len = -ENOTCONN;
2572 	else
2573 		len = bc_sendto(req);
2574 	mutex_unlock(&xprt->xpt_mutex);
2575 
2576 	if (len > 0)
2577 		len = 0;
2578 
2579 	return len;
2580 }
2581 
2582 /*
2583  * The close routine. Since this is client initiated, we do nothing
2584  */
2585 
2586 static void bc_close(struct rpc_xprt *xprt)
2587 {
2588 }
2589 
2590 /*
2591  * The xprt destroy routine. Again, because this connection is client
2592  * initiated, we do nothing
2593  */
2594 
2595 static void bc_destroy(struct rpc_xprt *xprt)
2596 {
2597 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2598 
2599 	xs_xprt_free(xprt);
2600 	module_put(THIS_MODULE);
2601 }
2602 
2603 static struct rpc_xprt_ops xs_local_ops = {
2604 	.reserve_xprt		= xprt_reserve_xprt,
2605 	.release_xprt		= xs_tcp_release_xprt,
2606 	.alloc_slot		= xprt_alloc_slot,
2607 	.rpcbind		= xs_local_rpcbind,
2608 	.set_port		= xs_local_set_port,
2609 	.connect		= xs_local_connect,
2610 	.buf_alloc		= rpc_malloc,
2611 	.buf_free		= rpc_free,
2612 	.send_request		= xs_local_send_request,
2613 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2614 	.close			= xs_close,
2615 	.destroy		= xs_destroy,
2616 	.print_stats		= xs_local_print_stats,
2617 	.enable_swap		= xs_enable_swap,
2618 	.disable_swap		= xs_disable_swap,
2619 };
2620 
2621 static struct rpc_xprt_ops xs_udp_ops = {
2622 	.set_buffer_size	= xs_udp_set_buffer_size,
2623 	.reserve_xprt		= xprt_reserve_xprt_cong,
2624 	.release_xprt		= xprt_release_xprt_cong,
2625 	.alloc_slot		= xprt_alloc_slot,
2626 	.rpcbind		= rpcb_getport_async,
2627 	.set_port		= xs_set_port,
2628 	.connect		= xs_connect,
2629 	.buf_alloc		= rpc_malloc,
2630 	.buf_free		= rpc_free,
2631 	.send_request		= xs_udp_send_request,
2632 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2633 	.timer			= xs_udp_timer,
2634 	.release_request	= xprt_release_rqst_cong,
2635 	.close			= xs_close,
2636 	.destroy		= xs_destroy,
2637 	.print_stats		= xs_udp_print_stats,
2638 	.enable_swap		= xs_enable_swap,
2639 	.disable_swap		= xs_disable_swap,
2640 	.inject_disconnect	= xs_inject_disconnect,
2641 };
2642 
2643 static struct rpc_xprt_ops xs_tcp_ops = {
2644 	.reserve_xprt		= xprt_reserve_xprt,
2645 	.release_xprt		= xs_tcp_release_xprt,
2646 	.alloc_slot		= xprt_lock_and_alloc_slot,
2647 	.rpcbind		= rpcb_getport_async,
2648 	.set_port		= xs_set_port,
2649 	.connect		= xs_connect,
2650 	.buf_alloc		= rpc_malloc,
2651 	.buf_free		= rpc_free,
2652 	.send_request		= xs_tcp_send_request,
2653 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2654 	.close			= xs_tcp_shutdown,
2655 	.destroy		= xs_destroy,
2656 	.print_stats		= xs_tcp_print_stats,
2657 	.enable_swap		= xs_enable_swap,
2658 	.disable_swap		= xs_disable_swap,
2659 	.inject_disconnect	= xs_inject_disconnect,
2660 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2661 	.bc_setup		= xprt_setup_bc,
2662 	.bc_up			= xs_tcp_bc_up,
2663 	.bc_free_rqst		= xprt_free_bc_rqst,
2664 	.bc_destroy		= xprt_destroy_bc,
2665 #endif
2666 };
2667 
2668 /*
2669  * The rpc_xprt_ops for the server backchannel
2670  */
2671 
2672 static struct rpc_xprt_ops bc_tcp_ops = {
2673 	.reserve_xprt		= xprt_reserve_xprt,
2674 	.release_xprt		= xprt_release_xprt,
2675 	.alloc_slot		= xprt_alloc_slot,
2676 	.buf_alloc		= bc_malloc,
2677 	.buf_free		= bc_free,
2678 	.send_request		= bc_send_request,
2679 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2680 	.close			= bc_close,
2681 	.destroy		= bc_destroy,
2682 	.print_stats		= xs_tcp_print_stats,
2683 	.enable_swap		= xs_enable_swap,
2684 	.disable_swap		= xs_disable_swap,
2685 	.inject_disconnect	= xs_inject_disconnect,
2686 };
2687 
2688 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2689 {
2690 	static const struct sockaddr_in sin = {
2691 		.sin_family		= AF_INET,
2692 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2693 	};
2694 	static const struct sockaddr_in6 sin6 = {
2695 		.sin6_family		= AF_INET6,
2696 		.sin6_addr		= IN6ADDR_ANY_INIT,
2697 	};
2698 
2699 	switch (family) {
2700 	case AF_LOCAL:
2701 		break;
2702 	case AF_INET:
2703 		memcpy(sap, &sin, sizeof(sin));
2704 		break;
2705 	case AF_INET6:
2706 		memcpy(sap, &sin6, sizeof(sin6));
2707 		break;
2708 	default:
2709 		dprintk("RPC:       %s: Bad address family\n", __func__);
2710 		return -EAFNOSUPPORT;
2711 	}
2712 	return 0;
2713 }
2714 
2715 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2716 				      unsigned int slot_table_size,
2717 				      unsigned int max_slot_table_size)
2718 {
2719 	struct rpc_xprt *xprt;
2720 	struct sock_xprt *new;
2721 
2722 	if (args->addrlen > sizeof(xprt->addr)) {
2723 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2724 		return ERR_PTR(-EBADF);
2725 	}
2726 
2727 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2728 			max_slot_table_size);
2729 	if (xprt == NULL) {
2730 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2731 				"rpc_xprt\n");
2732 		return ERR_PTR(-ENOMEM);
2733 	}
2734 
2735 	new = container_of(xprt, struct sock_xprt, xprt);
2736 	mutex_init(&new->recv_mutex);
2737 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2738 	xprt->addrlen = args->addrlen;
2739 	if (args->srcaddr)
2740 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2741 	else {
2742 		int err;
2743 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2744 					(struct sockaddr *)&new->srcaddr);
2745 		if (err != 0) {
2746 			xprt_free(xprt);
2747 			return ERR_PTR(err);
2748 		}
2749 	}
2750 
2751 	return xprt;
2752 }
2753 
2754 static const struct rpc_timeout xs_local_default_timeout = {
2755 	.to_initval = 10 * HZ,
2756 	.to_maxval = 10 * HZ,
2757 	.to_retries = 2,
2758 };
2759 
2760 /**
2761  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2762  * @args: rpc transport creation arguments
2763  *
2764  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2765  */
2766 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2767 {
2768 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2769 	struct sock_xprt *transport;
2770 	struct rpc_xprt *xprt;
2771 	struct rpc_xprt *ret;
2772 
2773 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2774 			xprt_max_tcp_slot_table_entries);
2775 	if (IS_ERR(xprt))
2776 		return xprt;
2777 	transport = container_of(xprt, struct sock_xprt, xprt);
2778 
2779 	xprt->prot = 0;
2780 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2781 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2782 
2783 	xprt->bind_timeout = XS_BIND_TO;
2784 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2785 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2786 
2787 	xprt->ops = &xs_local_ops;
2788 	xprt->timeout = &xs_local_default_timeout;
2789 
2790 	INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2791 	INIT_DELAYED_WORK(&transport->connect_worker,
2792 			xs_dummy_setup_socket);
2793 
2794 	switch (sun->sun_family) {
2795 	case AF_LOCAL:
2796 		if (sun->sun_path[0] != '/') {
2797 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2798 					sun->sun_path);
2799 			ret = ERR_PTR(-EINVAL);
2800 			goto out_err;
2801 		}
2802 		xprt_set_bound(xprt);
2803 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2804 		ret = ERR_PTR(xs_local_setup_socket(transport));
2805 		if (ret)
2806 			goto out_err;
2807 		break;
2808 	default:
2809 		ret = ERR_PTR(-EAFNOSUPPORT);
2810 		goto out_err;
2811 	}
2812 
2813 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2814 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2815 
2816 	if (try_module_get(THIS_MODULE))
2817 		return xprt;
2818 	ret = ERR_PTR(-EINVAL);
2819 out_err:
2820 	xs_xprt_free(xprt);
2821 	return ret;
2822 }
2823 
2824 static const struct rpc_timeout xs_udp_default_timeout = {
2825 	.to_initval = 5 * HZ,
2826 	.to_maxval = 30 * HZ,
2827 	.to_increment = 5 * HZ,
2828 	.to_retries = 5,
2829 };
2830 
2831 /**
2832  * xs_setup_udp - Set up transport to use a UDP socket
2833  * @args: rpc transport creation arguments
2834  *
2835  */
2836 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2837 {
2838 	struct sockaddr *addr = args->dstaddr;
2839 	struct rpc_xprt *xprt;
2840 	struct sock_xprt *transport;
2841 	struct rpc_xprt *ret;
2842 
2843 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2844 			xprt_udp_slot_table_entries);
2845 	if (IS_ERR(xprt))
2846 		return xprt;
2847 	transport = container_of(xprt, struct sock_xprt, xprt);
2848 
2849 	xprt->prot = IPPROTO_UDP;
2850 	xprt->tsh_size = 0;
2851 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2852 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2853 
2854 	xprt->bind_timeout = XS_BIND_TO;
2855 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2856 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2857 
2858 	xprt->ops = &xs_udp_ops;
2859 
2860 	xprt->timeout = &xs_udp_default_timeout;
2861 
2862 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2863 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2864 
2865 	switch (addr->sa_family) {
2866 	case AF_INET:
2867 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2868 			xprt_set_bound(xprt);
2869 
2870 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2871 		break;
2872 	case AF_INET6:
2873 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2874 			xprt_set_bound(xprt);
2875 
2876 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2877 		break;
2878 	default:
2879 		ret = ERR_PTR(-EAFNOSUPPORT);
2880 		goto out_err;
2881 	}
2882 
2883 	if (xprt_bound(xprt))
2884 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2885 				xprt->address_strings[RPC_DISPLAY_ADDR],
2886 				xprt->address_strings[RPC_DISPLAY_PORT],
2887 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2888 	else
2889 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2890 				xprt->address_strings[RPC_DISPLAY_ADDR],
2891 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2892 
2893 	if (try_module_get(THIS_MODULE))
2894 		return xprt;
2895 	ret = ERR_PTR(-EINVAL);
2896 out_err:
2897 	xs_xprt_free(xprt);
2898 	return ret;
2899 }
2900 
2901 static const struct rpc_timeout xs_tcp_default_timeout = {
2902 	.to_initval = 60 * HZ,
2903 	.to_maxval = 60 * HZ,
2904 	.to_retries = 2,
2905 };
2906 
2907 /**
2908  * xs_setup_tcp - Set up transport to use a TCP socket
2909  * @args: rpc transport creation arguments
2910  *
2911  */
2912 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2913 {
2914 	struct sockaddr *addr = args->dstaddr;
2915 	struct rpc_xprt *xprt;
2916 	struct sock_xprt *transport;
2917 	struct rpc_xprt *ret;
2918 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2919 
2920 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2921 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2922 
2923 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2924 			max_slot_table_size);
2925 	if (IS_ERR(xprt))
2926 		return xprt;
2927 	transport = container_of(xprt, struct sock_xprt, xprt);
2928 
2929 	xprt->prot = IPPROTO_TCP;
2930 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2931 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2932 
2933 	xprt->bind_timeout = XS_BIND_TO;
2934 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2935 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2936 
2937 	xprt->ops = &xs_tcp_ops;
2938 	xprt->timeout = &xs_tcp_default_timeout;
2939 
2940 	INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
2941 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2942 
2943 	switch (addr->sa_family) {
2944 	case AF_INET:
2945 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2946 			xprt_set_bound(xprt);
2947 
2948 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2949 		break;
2950 	case AF_INET6:
2951 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2952 			xprt_set_bound(xprt);
2953 
2954 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2955 		break;
2956 	default:
2957 		ret = ERR_PTR(-EAFNOSUPPORT);
2958 		goto out_err;
2959 	}
2960 
2961 	if (xprt_bound(xprt))
2962 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2963 				xprt->address_strings[RPC_DISPLAY_ADDR],
2964 				xprt->address_strings[RPC_DISPLAY_PORT],
2965 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2966 	else
2967 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2968 				xprt->address_strings[RPC_DISPLAY_ADDR],
2969 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2970 
2971 	if (try_module_get(THIS_MODULE))
2972 		return xprt;
2973 	ret = ERR_PTR(-EINVAL);
2974 out_err:
2975 	xs_xprt_free(xprt);
2976 	return ret;
2977 }
2978 
2979 /**
2980  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2981  * @args: rpc transport creation arguments
2982  *
2983  */
2984 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2985 {
2986 	struct sockaddr *addr = args->dstaddr;
2987 	struct rpc_xprt *xprt;
2988 	struct sock_xprt *transport;
2989 	struct svc_sock *bc_sock;
2990 	struct rpc_xprt *ret;
2991 
2992 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2993 			xprt_tcp_slot_table_entries);
2994 	if (IS_ERR(xprt))
2995 		return xprt;
2996 	transport = container_of(xprt, struct sock_xprt, xprt);
2997 
2998 	xprt->prot = IPPROTO_TCP;
2999 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3000 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3001 	xprt->timeout = &xs_tcp_default_timeout;
3002 
3003 	/* backchannel */
3004 	xprt_set_bound(xprt);
3005 	xprt->bind_timeout = 0;
3006 	xprt->reestablish_timeout = 0;
3007 	xprt->idle_timeout = 0;
3008 
3009 	xprt->ops = &bc_tcp_ops;
3010 
3011 	switch (addr->sa_family) {
3012 	case AF_INET:
3013 		xs_format_peer_addresses(xprt, "tcp",
3014 					 RPCBIND_NETID_TCP);
3015 		break;
3016 	case AF_INET6:
3017 		xs_format_peer_addresses(xprt, "tcp",
3018 				   RPCBIND_NETID_TCP6);
3019 		break;
3020 	default:
3021 		ret = ERR_PTR(-EAFNOSUPPORT);
3022 		goto out_err;
3023 	}
3024 
3025 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3026 			xprt->address_strings[RPC_DISPLAY_ADDR],
3027 			xprt->address_strings[RPC_DISPLAY_PORT],
3028 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3029 
3030 	/*
3031 	 * Once we've associated a backchannel xprt with a connection,
3032 	 * we want to keep it around as long as the connection lasts,
3033 	 * in case we need to start using it for a backchannel again;
3034 	 * this reference won't be dropped until bc_xprt is destroyed.
3035 	 */
3036 	xprt_get(xprt);
3037 	args->bc_xprt->xpt_bc_xprt = xprt;
3038 	xprt->bc_xprt = args->bc_xprt;
3039 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3040 	transport->sock = bc_sock->sk_sock;
3041 	transport->inet = bc_sock->sk_sk;
3042 
3043 	/*
3044 	 * Since we don't want connections for the backchannel, we set
3045 	 * the xprt status to connected
3046 	 */
3047 	xprt_set_connected(xprt);
3048 
3049 	if (try_module_get(THIS_MODULE))
3050 		return xprt;
3051 
3052 	args->bc_xprt->xpt_bc_xprt = NULL;
3053 	xprt_put(xprt);
3054 	ret = ERR_PTR(-EINVAL);
3055 out_err:
3056 	xs_xprt_free(xprt);
3057 	return ret;
3058 }
3059 
3060 static struct xprt_class	xs_local_transport = {
3061 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3062 	.name		= "named UNIX socket",
3063 	.owner		= THIS_MODULE,
3064 	.ident		= XPRT_TRANSPORT_LOCAL,
3065 	.setup		= xs_setup_local,
3066 };
3067 
3068 static struct xprt_class	xs_udp_transport = {
3069 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3070 	.name		= "udp",
3071 	.owner		= THIS_MODULE,
3072 	.ident		= XPRT_TRANSPORT_UDP,
3073 	.setup		= xs_setup_udp,
3074 };
3075 
3076 static struct xprt_class	xs_tcp_transport = {
3077 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3078 	.name		= "tcp",
3079 	.owner		= THIS_MODULE,
3080 	.ident		= XPRT_TRANSPORT_TCP,
3081 	.setup		= xs_setup_tcp,
3082 };
3083 
3084 static struct xprt_class	xs_bc_tcp_transport = {
3085 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3086 	.name		= "tcp NFSv4.1 backchannel",
3087 	.owner		= THIS_MODULE,
3088 	.ident		= XPRT_TRANSPORT_BC_TCP,
3089 	.setup		= xs_setup_bc_tcp,
3090 };
3091 
3092 /**
3093  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3094  *
3095  */
3096 int init_socket_xprt(void)
3097 {
3098 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3099 	if (!sunrpc_table_header)
3100 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3101 #endif
3102 
3103 	xprt_register_transport(&xs_local_transport);
3104 	xprt_register_transport(&xs_udp_transport);
3105 	xprt_register_transport(&xs_tcp_transport);
3106 	xprt_register_transport(&xs_bc_tcp_transport);
3107 
3108 	return 0;
3109 }
3110 
3111 /**
3112  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3113  *
3114  */
3115 void cleanup_socket_xprt(void)
3116 {
3117 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3118 	if (sunrpc_table_header) {
3119 		unregister_sysctl_table(sunrpc_table_header);
3120 		sunrpc_table_header = NULL;
3121 	}
3122 #endif
3123 
3124 	xprt_unregister_transport(&xs_local_transport);
3125 	xprt_unregister_transport(&xs_udp_transport);
3126 	xprt_unregister_transport(&xs_tcp_transport);
3127 	xprt_unregister_transport(&xs_bc_tcp_transport);
3128 }
3129 
3130 static int param_set_uint_minmax(const char *val,
3131 		const struct kernel_param *kp,
3132 		unsigned int min, unsigned int max)
3133 {
3134 	unsigned int num;
3135 	int ret;
3136 
3137 	if (!val)
3138 		return -EINVAL;
3139 	ret = kstrtouint(val, 0, &num);
3140 	if (ret == -EINVAL || num < min || num > max)
3141 		return -EINVAL;
3142 	*((unsigned int *)kp->arg) = num;
3143 	return 0;
3144 }
3145 
3146 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3147 {
3148 	return param_set_uint_minmax(val, kp,
3149 			RPC_MIN_RESVPORT,
3150 			RPC_MAX_RESVPORT);
3151 }
3152 
3153 static const struct kernel_param_ops param_ops_portnr = {
3154 	.set = param_set_portnr,
3155 	.get = param_get_uint,
3156 };
3157 
3158 #define param_check_portnr(name, p) \
3159 	__param_check(name, p, unsigned int);
3160 
3161 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3162 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3163 
3164 static int param_set_slot_table_size(const char *val,
3165 				     const struct kernel_param *kp)
3166 {
3167 	return param_set_uint_minmax(val, kp,
3168 			RPC_MIN_SLOT_TABLE,
3169 			RPC_MAX_SLOT_TABLE);
3170 }
3171 
3172 static const struct kernel_param_ops param_ops_slot_table_size = {
3173 	.set = param_set_slot_table_size,
3174 	.get = param_get_uint,
3175 };
3176 
3177 #define param_check_slot_table_size(name, p) \
3178 	__param_check(name, p, unsigned int);
3179 
3180 static int param_set_max_slot_table_size(const char *val,
3181 				     const struct kernel_param *kp)
3182 {
3183 	return param_set_uint_minmax(val, kp,
3184 			RPC_MIN_SLOT_TABLE,
3185 			RPC_MAX_SLOT_TABLE_LIMIT);
3186 }
3187 
3188 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3189 	.set = param_set_max_slot_table_size,
3190 	.get = param_get_uint,
3191 };
3192 
3193 #define param_check_max_slot_table_size(name, p) \
3194 	__param_check(name, p, unsigned int);
3195 
3196 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3197 		   slot_table_size, 0644);
3198 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3199 		   max_slot_table_size, 0644);
3200 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3201 		   slot_table_size, 0644);
3202 
3203