xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision 161f4089)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44 
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49 
50 #include <trace/events/sunrpc.h>
51 
52 #include "sunrpc.h"
53 
54 static void xs_close(struct rpc_xprt *xprt);
55 
56 /*
57  * xprtsock tunables
58  */
59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
62 
63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
65 
66 #define XS_TCP_LINGER_TO	(15U * HZ)
67 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
68 
69 /*
70  * We can register our own files under /proc/sys/sunrpc by
71  * calling register_sysctl_table() again.  The files in that
72  * directory become the union of all files registered there.
73  *
74  * We simply need to make sure that we don't collide with
75  * someone else's file names!
76  */
77 
78 #ifdef RPC_DEBUG
79 
80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
85 
86 static struct ctl_table_header *sunrpc_table_header;
87 
88 /*
89  * FIXME: changing the UDP slot table size should also resize the UDP
90  *        socket buffers for existing UDP transports
91  */
92 static struct ctl_table xs_tunables_table[] = {
93 	{
94 		.procname	= "udp_slot_table_entries",
95 		.data		= &xprt_udp_slot_table_entries,
96 		.maxlen		= sizeof(unsigned int),
97 		.mode		= 0644,
98 		.proc_handler	= proc_dointvec_minmax,
99 		.extra1		= &min_slot_table_size,
100 		.extra2		= &max_slot_table_size
101 	},
102 	{
103 		.procname	= "tcp_slot_table_entries",
104 		.data		= &xprt_tcp_slot_table_entries,
105 		.maxlen		= sizeof(unsigned int),
106 		.mode		= 0644,
107 		.proc_handler	= proc_dointvec_minmax,
108 		.extra1		= &min_slot_table_size,
109 		.extra2		= &max_slot_table_size
110 	},
111 	{
112 		.procname	= "tcp_max_slot_table_entries",
113 		.data		= &xprt_max_tcp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_tcp_slot_table_limit
119 	},
120 	{
121 		.procname	= "min_resvport",
122 		.data		= &xprt_min_resvport,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &xprt_min_resvport_limit,
127 		.extra2		= &xprt_max_resvport_limit
128 	},
129 	{
130 		.procname	= "max_resvport",
131 		.data		= &xprt_max_resvport,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &xprt_min_resvport_limit,
136 		.extra2		= &xprt_max_resvport_limit
137 	},
138 	{
139 		.procname	= "tcp_fin_timeout",
140 		.data		= &xs_tcp_fin_timeout,
141 		.maxlen		= sizeof(xs_tcp_fin_timeout),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_jiffies,
144 	},
145 	{ },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149 	{
150 		.procname	= "sunrpc",
151 		.mode		= 0555,
152 		.child		= xs_tunables_table
153 	},
154 	{ },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO		(60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO		(2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
180 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
188 
189 #ifdef RPC_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 struct sock_xprt {
220 	struct rpc_xprt		xprt;
221 
222 	/*
223 	 * Network layer
224 	 */
225 	struct socket *		sock;
226 	struct sock *		inet;
227 
228 	/*
229 	 * State of TCP reply receive
230 	 */
231 	__be32			tcp_fraghdr,
232 				tcp_xid,
233 				tcp_calldir;
234 
235 	u32			tcp_offset,
236 				tcp_reclen;
237 
238 	unsigned long		tcp_copied,
239 				tcp_flags;
240 
241 	/*
242 	 * Connection of transports
243 	 */
244 	struct delayed_work	connect_worker;
245 	struct sockaddr_storage	srcaddr;
246 	unsigned short		srcport;
247 
248 	/*
249 	 * UDP socket buffer size parameters
250 	 */
251 	size_t			rcvsize,
252 				sndsize;
253 
254 	/*
255 	 * Saved socket callback addresses
256 	 */
257 	void			(*old_data_ready)(struct sock *, int);
258 	void			(*old_state_change)(struct sock *);
259 	void			(*old_write_space)(struct sock *);
260 };
261 
262 /*
263  * TCP receive state flags
264  */
265 #define TCP_RCV_LAST_FRAG	(1UL << 0)
266 #define TCP_RCV_COPY_FRAGHDR	(1UL << 1)
267 #define TCP_RCV_COPY_XID	(1UL << 2)
268 #define TCP_RCV_COPY_DATA	(1UL << 3)
269 #define TCP_RCV_READ_CALLDIR	(1UL << 4)
270 #define TCP_RCV_COPY_CALLDIR	(1UL << 5)
271 
272 /*
273  * TCP RPC flags
274  */
275 #define TCP_RPC_REPLY		(1UL << 6)
276 
277 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
278 {
279 	return (struct sockaddr *) &xprt->addr;
280 }
281 
282 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
283 {
284 	return (struct sockaddr_un *) &xprt->addr;
285 }
286 
287 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
288 {
289 	return (struct sockaddr_in *) &xprt->addr;
290 }
291 
292 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
293 {
294 	return (struct sockaddr_in6 *) &xprt->addr;
295 }
296 
297 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
298 {
299 	struct sockaddr *sap = xs_addr(xprt);
300 	struct sockaddr_in6 *sin6;
301 	struct sockaddr_in *sin;
302 	struct sockaddr_un *sun;
303 	char buf[128];
304 
305 	switch (sap->sa_family) {
306 	case AF_LOCAL:
307 		sun = xs_addr_un(xprt);
308 		strlcpy(buf, sun->sun_path, sizeof(buf));
309 		xprt->address_strings[RPC_DISPLAY_ADDR] =
310 						kstrdup(buf, GFP_KERNEL);
311 		break;
312 	case AF_INET:
313 		(void)rpc_ntop(sap, buf, sizeof(buf));
314 		xprt->address_strings[RPC_DISPLAY_ADDR] =
315 						kstrdup(buf, GFP_KERNEL);
316 		sin = xs_addr_in(xprt);
317 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
318 		break;
319 	case AF_INET6:
320 		(void)rpc_ntop(sap, buf, sizeof(buf));
321 		xprt->address_strings[RPC_DISPLAY_ADDR] =
322 						kstrdup(buf, GFP_KERNEL);
323 		sin6 = xs_addr_in6(xprt);
324 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
325 		break;
326 	default:
327 		BUG();
328 	}
329 
330 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
331 }
332 
333 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
334 {
335 	struct sockaddr *sap = xs_addr(xprt);
336 	char buf[128];
337 
338 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
339 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
340 
341 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
342 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
343 }
344 
345 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
346 				     const char *protocol,
347 				     const char *netid)
348 {
349 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
350 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
351 	xs_format_common_peer_addresses(xprt);
352 	xs_format_common_peer_ports(xprt);
353 }
354 
355 static void xs_update_peer_port(struct rpc_xprt *xprt)
356 {
357 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
358 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
359 
360 	xs_format_common_peer_ports(xprt);
361 }
362 
363 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
364 {
365 	unsigned int i;
366 
367 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
368 		switch (i) {
369 		case RPC_DISPLAY_PROTO:
370 		case RPC_DISPLAY_NETID:
371 			continue;
372 		default:
373 			kfree(xprt->address_strings[i]);
374 		}
375 }
376 
377 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
378 
379 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
380 {
381 	struct msghdr msg = {
382 		.msg_name	= addr,
383 		.msg_namelen	= addrlen,
384 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
385 	};
386 	struct kvec iov = {
387 		.iov_base	= vec->iov_base + base,
388 		.iov_len	= vec->iov_len - base,
389 	};
390 
391 	if (iov.iov_len != 0)
392 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
393 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
394 }
395 
396 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
397 {
398 	struct page **ppage;
399 	unsigned int remainder;
400 	int err, sent = 0;
401 
402 	remainder = xdr->page_len - base;
403 	base += xdr->page_base;
404 	ppage = xdr->pages + (base >> PAGE_SHIFT);
405 	base &= ~PAGE_MASK;
406 	for(;;) {
407 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
408 		int flags = XS_SENDMSG_FLAGS;
409 
410 		remainder -= len;
411 		if (remainder != 0 || more)
412 			flags |= MSG_MORE;
413 		err = sock->ops->sendpage(sock, *ppage, base, len, flags);
414 		if (remainder == 0 || err != len)
415 			break;
416 		sent += err;
417 		ppage++;
418 		base = 0;
419 	}
420 	if (sent == 0)
421 		return err;
422 	if (err > 0)
423 		sent += err;
424 	return sent;
425 }
426 
427 /**
428  * xs_sendpages - write pages directly to a socket
429  * @sock: socket to send on
430  * @addr: UDP only -- address of destination
431  * @addrlen: UDP only -- length of destination address
432  * @xdr: buffer containing this request
433  * @base: starting position in the buffer
434  *
435  */
436 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
437 {
438 	unsigned int remainder = xdr->len - base;
439 	int err, sent = 0;
440 
441 	if (unlikely(!sock))
442 		return -ENOTSOCK;
443 
444 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
445 	if (base != 0) {
446 		addr = NULL;
447 		addrlen = 0;
448 	}
449 
450 	if (base < xdr->head[0].iov_len || addr != NULL) {
451 		unsigned int len = xdr->head[0].iov_len - base;
452 		remainder -= len;
453 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
454 		if (remainder == 0 || err != len)
455 			goto out;
456 		sent += err;
457 		base = 0;
458 	} else
459 		base -= xdr->head[0].iov_len;
460 
461 	if (base < xdr->page_len) {
462 		unsigned int len = xdr->page_len - base;
463 		remainder -= len;
464 		err = xs_send_pagedata(sock, xdr, base, remainder != 0);
465 		if (remainder == 0 || err != len)
466 			goto out;
467 		sent += err;
468 		base = 0;
469 	} else
470 		base -= xdr->page_len;
471 
472 	if (base >= xdr->tail[0].iov_len)
473 		return sent;
474 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
475 out:
476 	if (sent == 0)
477 		return err;
478 	if (err > 0)
479 		sent += err;
480 	return sent;
481 }
482 
483 static void xs_nospace_callback(struct rpc_task *task)
484 {
485 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
486 
487 	transport->inet->sk_write_pending--;
488 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
489 }
490 
491 /**
492  * xs_nospace - place task on wait queue if transmit was incomplete
493  * @task: task to put to sleep
494  *
495  */
496 static int xs_nospace(struct rpc_task *task)
497 {
498 	struct rpc_rqst *req = task->tk_rqstp;
499 	struct rpc_xprt *xprt = req->rq_xprt;
500 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
501 	int ret = -EAGAIN;
502 
503 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
504 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
505 			req->rq_slen);
506 
507 	/* Protect against races with write_space */
508 	spin_lock_bh(&xprt->transport_lock);
509 
510 	/* Don't race with disconnect */
511 	if (xprt_connected(xprt)) {
512 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
513 			/*
514 			 * Notify TCP that we're limited by the application
515 			 * window size
516 			 */
517 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
518 			transport->inet->sk_write_pending++;
519 			/* ...and wait for more buffer space */
520 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
521 		}
522 	} else {
523 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
524 		ret = -ENOTCONN;
525 	}
526 
527 	spin_unlock_bh(&xprt->transport_lock);
528 	return ret;
529 }
530 
531 /*
532  * Construct a stream transport record marker in @buf.
533  */
534 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
535 {
536 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
537 	rpc_fraghdr *base = buf->head[0].iov_base;
538 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
539 }
540 
541 /**
542  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
543  * @task: RPC task that manages the state of an RPC request
544  *
545  * Return values:
546  *        0:	The request has been sent
547  *   EAGAIN:	The socket was blocked, please call again later to
548  *		complete the request
549  * ENOTCONN:	Caller needs to invoke connect logic then call again
550  *    other:	Some other error occured, the request was not sent
551  */
552 static int xs_local_send_request(struct rpc_task *task)
553 {
554 	struct rpc_rqst *req = task->tk_rqstp;
555 	struct rpc_xprt *xprt = req->rq_xprt;
556 	struct sock_xprt *transport =
557 				container_of(xprt, struct sock_xprt, xprt);
558 	struct xdr_buf *xdr = &req->rq_snd_buf;
559 	int status;
560 
561 	xs_encode_stream_record_marker(&req->rq_snd_buf);
562 
563 	xs_pktdump("packet data:",
564 			req->rq_svec->iov_base, req->rq_svec->iov_len);
565 
566 	status = xs_sendpages(transport->sock, NULL, 0,
567 						xdr, req->rq_bytes_sent);
568 	dprintk("RPC:       %s(%u) = %d\n",
569 			__func__, xdr->len - req->rq_bytes_sent, status);
570 	if (likely(status >= 0)) {
571 		req->rq_bytes_sent += status;
572 		req->rq_xmit_bytes_sent += status;
573 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
574 			req->rq_bytes_sent = 0;
575 			return 0;
576 		}
577 		status = -EAGAIN;
578 	}
579 
580 	switch (status) {
581 	case -EAGAIN:
582 		status = xs_nospace(task);
583 		break;
584 	default:
585 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
586 			-status);
587 	case -EPIPE:
588 		xs_close(xprt);
589 		status = -ENOTCONN;
590 	}
591 
592 	return status;
593 }
594 
595 /**
596  * xs_udp_send_request - write an RPC request to a UDP socket
597  * @task: address of RPC task that manages the state of an RPC request
598  *
599  * Return values:
600  *        0:	The request has been sent
601  *   EAGAIN:	The socket was blocked, please call again later to
602  *		complete the request
603  * ENOTCONN:	Caller needs to invoke connect logic then call again
604  *    other:	Some other error occurred, the request was not sent
605  */
606 static int xs_udp_send_request(struct rpc_task *task)
607 {
608 	struct rpc_rqst *req = task->tk_rqstp;
609 	struct rpc_xprt *xprt = req->rq_xprt;
610 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
611 	struct xdr_buf *xdr = &req->rq_snd_buf;
612 	int status;
613 
614 	xs_pktdump("packet data:",
615 				req->rq_svec->iov_base,
616 				req->rq_svec->iov_len);
617 
618 	if (!xprt_bound(xprt))
619 		return -ENOTCONN;
620 	status = xs_sendpages(transport->sock,
621 			      xs_addr(xprt),
622 			      xprt->addrlen, xdr,
623 			      req->rq_bytes_sent);
624 
625 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
626 			xdr->len - req->rq_bytes_sent, status);
627 
628 	if (status >= 0) {
629 		req->rq_xmit_bytes_sent += status;
630 		if (status >= req->rq_slen)
631 			return 0;
632 		/* Still some bytes left; set up for a retry later. */
633 		status = -EAGAIN;
634 	}
635 
636 	switch (status) {
637 	case -ENOTSOCK:
638 		status = -ENOTCONN;
639 		/* Should we call xs_close() here? */
640 		break;
641 	case -EAGAIN:
642 		status = xs_nospace(task);
643 		break;
644 	default:
645 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
646 			-status);
647 	case -ENETUNREACH:
648 	case -EPIPE:
649 	case -ECONNREFUSED:
650 		/* When the server has died, an ICMP port unreachable message
651 		 * prompts ECONNREFUSED. */
652 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
653 	}
654 
655 	return status;
656 }
657 
658 /**
659  * xs_tcp_shutdown - gracefully shut down a TCP socket
660  * @xprt: transport
661  *
662  * Initiates a graceful shutdown of the TCP socket by calling the
663  * equivalent of shutdown(SHUT_WR);
664  */
665 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
666 {
667 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
668 	struct socket *sock = transport->sock;
669 
670 	if (sock != NULL) {
671 		kernel_sock_shutdown(sock, SHUT_WR);
672 		trace_rpc_socket_shutdown(xprt, sock);
673 	}
674 }
675 
676 /**
677  * xs_tcp_send_request - write an RPC request to a TCP socket
678  * @task: address of RPC task that manages the state of an RPC request
679  *
680  * Return values:
681  *        0:	The request has been sent
682  *   EAGAIN:	The socket was blocked, please call again later to
683  *		complete the request
684  * ENOTCONN:	Caller needs to invoke connect logic then call again
685  *    other:	Some other error occurred, the request was not sent
686  *
687  * XXX: In the case of soft timeouts, should we eventually give up
688  *	if sendmsg is not able to make progress?
689  */
690 static int xs_tcp_send_request(struct rpc_task *task)
691 {
692 	struct rpc_rqst *req = task->tk_rqstp;
693 	struct rpc_xprt *xprt = req->rq_xprt;
694 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
695 	struct xdr_buf *xdr = &req->rq_snd_buf;
696 	int status;
697 
698 	xs_encode_stream_record_marker(&req->rq_snd_buf);
699 
700 	xs_pktdump("packet data:",
701 				req->rq_svec->iov_base,
702 				req->rq_svec->iov_len);
703 
704 	/* Continue transmitting the packet/record. We must be careful
705 	 * to cope with writespace callbacks arriving _after_ we have
706 	 * called sendmsg(). */
707 	while (1) {
708 		status = xs_sendpages(transport->sock,
709 					NULL, 0, xdr, req->rq_bytes_sent);
710 
711 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
712 				xdr->len - req->rq_bytes_sent, status);
713 
714 		if (unlikely(status < 0))
715 			break;
716 
717 		/* If we've sent the entire packet, immediately
718 		 * reset the count of bytes sent. */
719 		req->rq_bytes_sent += status;
720 		req->rq_xmit_bytes_sent += status;
721 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
722 			req->rq_bytes_sent = 0;
723 			return 0;
724 		}
725 
726 		if (status != 0)
727 			continue;
728 		status = -EAGAIN;
729 		break;
730 	}
731 
732 	switch (status) {
733 	case -ENOTSOCK:
734 		status = -ENOTCONN;
735 		/* Should we call xs_close() here? */
736 		break;
737 	case -EAGAIN:
738 		status = xs_nospace(task);
739 		break;
740 	default:
741 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
742 			-status);
743 	case -ECONNRESET:
744 		xs_tcp_shutdown(xprt);
745 	case -ECONNREFUSED:
746 	case -ENOTCONN:
747 	case -EPIPE:
748 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
749 	}
750 
751 	return status;
752 }
753 
754 /**
755  * xs_tcp_release_xprt - clean up after a tcp transmission
756  * @xprt: transport
757  * @task: rpc task
758  *
759  * This cleans up if an error causes us to abort the transmission of a request.
760  * In this case, the socket may need to be reset in order to avoid confusing
761  * the server.
762  */
763 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
764 {
765 	struct rpc_rqst *req;
766 
767 	if (task != xprt->snd_task)
768 		return;
769 	if (task == NULL)
770 		goto out_release;
771 	req = task->tk_rqstp;
772 	if (req == NULL)
773 		goto out_release;
774 	if (req->rq_bytes_sent == 0)
775 		goto out_release;
776 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
777 		goto out_release;
778 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
779 out_release:
780 	xprt_release_xprt(xprt, task);
781 }
782 
783 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
784 {
785 	transport->old_data_ready = sk->sk_data_ready;
786 	transport->old_state_change = sk->sk_state_change;
787 	transport->old_write_space = sk->sk_write_space;
788 }
789 
790 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
791 {
792 	sk->sk_data_ready = transport->old_data_ready;
793 	sk->sk_state_change = transport->old_state_change;
794 	sk->sk_write_space = transport->old_write_space;
795 }
796 
797 static void xs_reset_transport(struct sock_xprt *transport)
798 {
799 	struct socket *sock = transport->sock;
800 	struct sock *sk = transport->inet;
801 
802 	if (sk == NULL)
803 		return;
804 
805 	transport->srcport = 0;
806 
807 	write_lock_bh(&sk->sk_callback_lock);
808 	transport->inet = NULL;
809 	transport->sock = NULL;
810 
811 	sk->sk_user_data = NULL;
812 
813 	xs_restore_old_callbacks(transport, sk);
814 	write_unlock_bh(&sk->sk_callback_lock);
815 
816 	sk->sk_no_check = 0;
817 
818 	trace_rpc_socket_close(&transport->xprt, sock);
819 	sock_release(sock);
820 }
821 
822 /**
823  * xs_close - close a socket
824  * @xprt: transport
825  *
826  * This is used when all requests are complete; ie, no DRC state remains
827  * on the server we want to save.
828  *
829  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
830  * xs_reset_transport() zeroing the socket from underneath a writer.
831  */
832 static void xs_close(struct rpc_xprt *xprt)
833 {
834 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
835 
836 	dprintk("RPC:       xs_close xprt %p\n", xprt);
837 
838 	cancel_delayed_work_sync(&transport->connect_worker);
839 
840 	xs_reset_transport(transport);
841 	xprt->reestablish_timeout = 0;
842 
843 	smp_mb__before_clear_bit();
844 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
845 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
846 	clear_bit(XPRT_CLOSING, &xprt->state);
847 	smp_mb__after_clear_bit();
848 	xprt_disconnect_done(xprt);
849 }
850 
851 static void xs_tcp_close(struct rpc_xprt *xprt)
852 {
853 	if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
854 		xs_close(xprt);
855 	else
856 		xs_tcp_shutdown(xprt);
857 }
858 
859 /**
860  * xs_destroy - prepare to shutdown a transport
861  * @xprt: doomed transport
862  *
863  */
864 static void xs_destroy(struct rpc_xprt *xprt)
865 {
866 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
867 
868 	xs_close(xprt);
869 	xs_free_peer_addresses(xprt);
870 	xprt_free(xprt);
871 	module_put(THIS_MODULE);
872 }
873 
874 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
875 {
876 	return (struct rpc_xprt *) sk->sk_user_data;
877 }
878 
879 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
880 {
881 	struct xdr_skb_reader desc = {
882 		.skb		= skb,
883 		.offset		= sizeof(rpc_fraghdr),
884 		.count		= skb->len - sizeof(rpc_fraghdr),
885 	};
886 
887 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
888 		return -1;
889 	if (desc.count)
890 		return -1;
891 	return 0;
892 }
893 
894 /**
895  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
896  * @sk: socket with data to read
897  * @len: how much data to read
898  *
899  * Currently this assumes we can read the whole reply in a single gulp.
900  */
901 static void xs_local_data_ready(struct sock *sk, int len)
902 {
903 	struct rpc_task *task;
904 	struct rpc_xprt *xprt;
905 	struct rpc_rqst *rovr;
906 	struct sk_buff *skb;
907 	int err, repsize, copied;
908 	u32 _xid;
909 	__be32 *xp;
910 
911 	read_lock_bh(&sk->sk_callback_lock);
912 	dprintk("RPC:       %s...\n", __func__);
913 	xprt = xprt_from_sock(sk);
914 	if (xprt == NULL)
915 		goto out;
916 
917 	skb = skb_recv_datagram(sk, 0, 1, &err);
918 	if (skb == NULL)
919 		goto out;
920 
921 	repsize = skb->len - sizeof(rpc_fraghdr);
922 	if (repsize < 4) {
923 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
924 		goto dropit;
925 	}
926 
927 	/* Copy the XID from the skb... */
928 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
929 	if (xp == NULL)
930 		goto dropit;
931 
932 	/* Look up and lock the request corresponding to the given XID */
933 	spin_lock(&xprt->transport_lock);
934 	rovr = xprt_lookup_rqst(xprt, *xp);
935 	if (!rovr)
936 		goto out_unlock;
937 	task = rovr->rq_task;
938 
939 	copied = rovr->rq_private_buf.buflen;
940 	if (copied > repsize)
941 		copied = repsize;
942 
943 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
944 		dprintk("RPC:       sk_buff copy failed\n");
945 		goto out_unlock;
946 	}
947 
948 	xprt_complete_rqst(task, copied);
949 
950  out_unlock:
951 	spin_unlock(&xprt->transport_lock);
952  dropit:
953 	skb_free_datagram(sk, skb);
954  out:
955 	read_unlock_bh(&sk->sk_callback_lock);
956 }
957 
958 /**
959  * xs_udp_data_ready - "data ready" callback for UDP sockets
960  * @sk: socket with data to read
961  * @len: how much data to read
962  *
963  */
964 static void xs_udp_data_ready(struct sock *sk, int len)
965 {
966 	struct rpc_task *task;
967 	struct rpc_xprt *xprt;
968 	struct rpc_rqst *rovr;
969 	struct sk_buff *skb;
970 	int err, repsize, copied;
971 	u32 _xid;
972 	__be32 *xp;
973 
974 	read_lock_bh(&sk->sk_callback_lock);
975 	dprintk("RPC:       xs_udp_data_ready...\n");
976 	if (!(xprt = xprt_from_sock(sk)))
977 		goto out;
978 
979 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
980 		goto out;
981 
982 	repsize = skb->len - sizeof(struct udphdr);
983 	if (repsize < 4) {
984 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
985 		goto dropit;
986 	}
987 
988 	/* Copy the XID from the skb... */
989 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
990 				sizeof(_xid), &_xid);
991 	if (xp == NULL)
992 		goto dropit;
993 
994 	/* Look up and lock the request corresponding to the given XID */
995 	spin_lock(&xprt->transport_lock);
996 	rovr = xprt_lookup_rqst(xprt, *xp);
997 	if (!rovr)
998 		goto out_unlock;
999 	task = rovr->rq_task;
1000 
1001 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1002 		copied = repsize;
1003 
1004 	/* Suck it into the iovec, verify checksum if not done by hw. */
1005 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1006 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1007 		goto out_unlock;
1008 	}
1009 
1010 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1011 
1012 	xprt_adjust_cwnd(xprt, task, copied);
1013 	xprt_complete_rqst(task, copied);
1014 
1015  out_unlock:
1016 	spin_unlock(&xprt->transport_lock);
1017  dropit:
1018 	skb_free_datagram(sk, skb);
1019  out:
1020 	read_unlock_bh(&sk->sk_callback_lock);
1021 }
1022 
1023 /*
1024  * Helper function to force a TCP close if the server is sending
1025  * junk and/or it has put us in CLOSE_WAIT
1026  */
1027 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1028 {
1029 	set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1030 	xprt_force_disconnect(xprt);
1031 }
1032 
1033 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1034 {
1035 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1036 	size_t len, used;
1037 	char *p;
1038 
1039 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1040 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1041 	used = xdr_skb_read_bits(desc, p, len);
1042 	transport->tcp_offset += used;
1043 	if (used != len)
1044 		return;
1045 
1046 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1047 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1048 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1049 	else
1050 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1051 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1052 
1053 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1054 	transport->tcp_offset = 0;
1055 
1056 	/* Sanity check of the record length */
1057 	if (unlikely(transport->tcp_reclen < 8)) {
1058 		dprintk("RPC:       invalid TCP record fragment length\n");
1059 		xs_tcp_force_close(xprt);
1060 		return;
1061 	}
1062 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1063 			transport->tcp_reclen);
1064 }
1065 
1066 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1067 {
1068 	if (transport->tcp_offset == transport->tcp_reclen) {
1069 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1070 		transport->tcp_offset = 0;
1071 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1072 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1073 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1074 			transport->tcp_copied = 0;
1075 		}
1076 	}
1077 }
1078 
1079 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1080 {
1081 	size_t len, used;
1082 	char *p;
1083 
1084 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1085 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1086 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1087 	used = xdr_skb_read_bits(desc, p, len);
1088 	transport->tcp_offset += used;
1089 	if (used != len)
1090 		return;
1091 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1092 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1093 	transport->tcp_copied = 4;
1094 	dprintk("RPC:       reading %s XID %08x\n",
1095 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1096 							      : "request with",
1097 			ntohl(transport->tcp_xid));
1098 	xs_tcp_check_fraghdr(transport);
1099 }
1100 
1101 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1102 				       struct xdr_skb_reader *desc)
1103 {
1104 	size_t len, used;
1105 	u32 offset;
1106 	char *p;
1107 
1108 	/*
1109 	 * We want transport->tcp_offset to be 8 at the end of this routine
1110 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1111 	 * When this function is called for the first time,
1112 	 * transport->tcp_offset is 4 (after having already read the xid).
1113 	 */
1114 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1115 	len = sizeof(transport->tcp_calldir) - offset;
1116 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1117 	p = ((char *) &transport->tcp_calldir) + offset;
1118 	used = xdr_skb_read_bits(desc, p, len);
1119 	transport->tcp_offset += used;
1120 	if (used != len)
1121 		return;
1122 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1123 	/*
1124 	 * We don't yet have the XDR buffer, so we will write the calldir
1125 	 * out after we get the buffer from the 'struct rpc_rqst'
1126 	 */
1127 	switch (ntohl(transport->tcp_calldir)) {
1128 	case RPC_REPLY:
1129 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1130 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1131 		transport->tcp_flags |= TCP_RPC_REPLY;
1132 		break;
1133 	case RPC_CALL:
1134 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1135 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1136 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1137 		break;
1138 	default:
1139 		dprintk("RPC:       invalid request message type\n");
1140 		xs_tcp_force_close(&transport->xprt);
1141 	}
1142 	xs_tcp_check_fraghdr(transport);
1143 }
1144 
1145 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1146 				     struct xdr_skb_reader *desc,
1147 				     struct rpc_rqst *req)
1148 {
1149 	struct sock_xprt *transport =
1150 				container_of(xprt, struct sock_xprt, xprt);
1151 	struct xdr_buf *rcvbuf;
1152 	size_t len;
1153 	ssize_t r;
1154 
1155 	rcvbuf = &req->rq_private_buf;
1156 
1157 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1158 		/*
1159 		 * Save the RPC direction in the XDR buffer
1160 		 */
1161 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1162 			&transport->tcp_calldir,
1163 			sizeof(transport->tcp_calldir));
1164 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1165 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1166 	}
1167 
1168 	len = desc->count;
1169 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1170 		struct xdr_skb_reader my_desc;
1171 
1172 		len = transport->tcp_reclen - transport->tcp_offset;
1173 		memcpy(&my_desc, desc, sizeof(my_desc));
1174 		my_desc.count = len;
1175 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1176 					  &my_desc, xdr_skb_read_bits);
1177 		desc->count -= r;
1178 		desc->offset += r;
1179 	} else
1180 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1181 					  desc, xdr_skb_read_bits);
1182 
1183 	if (r > 0) {
1184 		transport->tcp_copied += r;
1185 		transport->tcp_offset += r;
1186 	}
1187 	if (r != len) {
1188 		/* Error when copying to the receive buffer,
1189 		 * usually because we weren't able to allocate
1190 		 * additional buffer pages. All we can do now
1191 		 * is turn off TCP_RCV_COPY_DATA, so the request
1192 		 * will not receive any additional updates,
1193 		 * and time out.
1194 		 * Any remaining data from this record will
1195 		 * be discarded.
1196 		 */
1197 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1198 		dprintk("RPC:       XID %08x truncated request\n",
1199 				ntohl(transport->tcp_xid));
1200 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1201 				"tcp_offset = %u, tcp_reclen = %u\n",
1202 				xprt, transport->tcp_copied,
1203 				transport->tcp_offset, transport->tcp_reclen);
1204 		return;
1205 	}
1206 
1207 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1208 			ntohl(transport->tcp_xid), r);
1209 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1210 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1211 			transport->tcp_offset, transport->tcp_reclen);
1212 
1213 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1214 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1215 	else if (transport->tcp_offset == transport->tcp_reclen) {
1216 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1217 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1218 	}
1219 }
1220 
1221 /*
1222  * Finds the request corresponding to the RPC xid and invokes the common
1223  * tcp read code to read the data.
1224  */
1225 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1226 				    struct xdr_skb_reader *desc)
1227 {
1228 	struct sock_xprt *transport =
1229 				container_of(xprt, struct sock_xprt, xprt);
1230 	struct rpc_rqst *req;
1231 
1232 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1233 
1234 	/* Find and lock the request corresponding to this xid */
1235 	spin_lock(&xprt->transport_lock);
1236 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1237 	if (!req) {
1238 		dprintk("RPC:       XID %08x request not found!\n",
1239 				ntohl(transport->tcp_xid));
1240 		spin_unlock(&xprt->transport_lock);
1241 		return -1;
1242 	}
1243 
1244 	xs_tcp_read_common(xprt, desc, req);
1245 
1246 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1247 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1248 
1249 	spin_unlock(&xprt->transport_lock);
1250 	return 0;
1251 }
1252 
1253 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1254 /*
1255  * Obtains an rpc_rqst previously allocated and invokes the common
1256  * tcp read code to read the data.  The result is placed in the callback
1257  * queue.
1258  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1259  * connection and return -1.
1260  */
1261 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1262 				       struct xdr_skb_reader *desc)
1263 {
1264 	struct sock_xprt *transport =
1265 				container_of(xprt, struct sock_xprt, xprt);
1266 	struct rpc_rqst *req;
1267 
1268 	req = xprt_alloc_bc_request(xprt);
1269 	if (req == NULL) {
1270 		printk(KERN_WARNING "Callback slot table overflowed\n");
1271 		xprt_force_disconnect(xprt);
1272 		return -1;
1273 	}
1274 
1275 	req->rq_xid = transport->tcp_xid;
1276 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1277 	xs_tcp_read_common(xprt, desc, req);
1278 
1279 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1280 		struct svc_serv *bc_serv = xprt->bc_serv;
1281 
1282 		/*
1283 		 * Add callback request to callback list.  The callback
1284 		 * service sleeps on the sv_cb_waitq waiting for new
1285 		 * requests.  Wake it up after adding enqueing the
1286 		 * request.
1287 		 */
1288 		dprintk("RPC:       add callback request to list\n");
1289 		spin_lock(&bc_serv->sv_cb_lock);
1290 		list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1291 		spin_unlock(&bc_serv->sv_cb_lock);
1292 		wake_up(&bc_serv->sv_cb_waitq);
1293 	}
1294 
1295 	req->rq_private_buf.len = transport->tcp_copied;
1296 
1297 	return 0;
1298 }
1299 
1300 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1301 					struct xdr_skb_reader *desc)
1302 {
1303 	struct sock_xprt *transport =
1304 				container_of(xprt, struct sock_xprt, xprt);
1305 
1306 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1307 		xs_tcp_read_reply(xprt, desc) :
1308 		xs_tcp_read_callback(xprt, desc);
1309 }
1310 #else
1311 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1312 					struct xdr_skb_reader *desc)
1313 {
1314 	return xs_tcp_read_reply(xprt, desc);
1315 }
1316 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1317 
1318 /*
1319  * Read data off the transport.  This can be either an RPC_CALL or an
1320  * RPC_REPLY.  Relay the processing to helper functions.
1321  */
1322 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1323 				    struct xdr_skb_reader *desc)
1324 {
1325 	struct sock_xprt *transport =
1326 				container_of(xprt, struct sock_xprt, xprt);
1327 
1328 	if (_xs_tcp_read_data(xprt, desc) == 0)
1329 		xs_tcp_check_fraghdr(transport);
1330 	else {
1331 		/*
1332 		 * The transport_lock protects the request handling.
1333 		 * There's no need to hold it to update the tcp_flags.
1334 		 */
1335 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1336 	}
1337 }
1338 
1339 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1340 {
1341 	size_t len;
1342 
1343 	len = transport->tcp_reclen - transport->tcp_offset;
1344 	if (len > desc->count)
1345 		len = desc->count;
1346 	desc->count -= len;
1347 	desc->offset += len;
1348 	transport->tcp_offset += len;
1349 	dprintk("RPC:       discarded %Zu bytes\n", len);
1350 	xs_tcp_check_fraghdr(transport);
1351 }
1352 
1353 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1354 {
1355 	struct rpc_xprt *xprt = rd_desc->arg.data;
1356 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1357 	struct xdr_skb_reader desc = {
1358 		.skb	= skb,
1359 		.offset	= offset,
1360 		.count	= len,
1361 	};
1362 
1363 	dprintk("RPC:       xs_tcp_data_recv started\n");
1364 	do {
1365 		/* Read in a new fragment marker if necessary */
1366 		/* Can we ever really expect to get completely empty fragments? */
1367 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1368 			xs_tcp_read_fraghdr(xprt, &desc);
1369 			continue;
1370 		}
1371 		/* Read in the xid if necessary */
1372 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1373 			xs_tcp_read_xid(transport, &desc);
1374 			continue;
1375 		}
1376 		/* Read in the call/reply flag */
1377 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1378 			xs_tcp_read_calldir(transport, &desc);
1379 			continue;
1380 		}
1381 		/* Read in the request data */
1382 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1383 			xs_tcp_read_data(xprt, &desc);
1384 			continue;
1385 		}
1386 		/* Skip over any trailing bytes on short reads */
1387 		xs_tcp_read_discard(transport, &desc);
1388 	} while (desc.count);
1389 	dprintk("RPC:       xs_tcp_data_recv done\n");
1390 	return len - desc.count;
1391 }
1392 
1393 /**
1394  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1395  * @sk: socket with data to read
1396  * @bytes: how much data to read
1397  *
1398  */
1399 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1400 {
1401 	struct rpc_xprt *xprt;
1402 	read_descriptor_t rd_desc;
1403 	int read;
1404 
1405 	dprintk("RPC:       xs_tcp_data_ready...\n");
1406 
1407 	read_lock_bh(&sk->sk_callback_lock);
1408 	if (!(xprt = xprt_from_sock(sk)))
1409 		goto out;
1410 	/* Any data means we had a useful conversation, so
1411 	 * the we don't need to delay the next reconnect
1412 	 */
1413 	if (xprt->reestablish_timeout)
1414 		xprt->reestablish_timeout = 0;
1415 
1416 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1417 	rd_desc.arg.data = xprt;
1418 	do {
1419 		rd_desc.count = 65536;
1420 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1421 	} while (read > 0);
1422 out:
1423 	read_unlock_bh(&sk->sk_callback_lock);
1424 }
1425 
1426 /*
1427  * Do the equivalent of linger/linger2 handling for dealing with
1428  * broken servers that don't close the socket in a timely
1429  * fashion
1430  */
1431 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1432 		unsigned long timeout)
1433 {
1434 	struct sock_xprt *transport;
1435 
1436 	if (xprt_test_and_set_connecting(xprt))
1437 		return;
1438 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1439 	transport = container_of(xprt, struct sock_xprt, xprt);
1440 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1441 			   timeout);
1442 }
1443 
1444 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1445 {
1446 	struct sock_xprt *transport;
1447 
1448 	transport = container_of(xprt, struct sock_xprt, xprt);
1449 
1450 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1451 	    !cancel_delayed_work(&transport->connect_worker))
1452 		return;
1453 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1454 	xprt_clear_connecting(xprt);
1455 }
1456 
1457 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1458 {
1459 	smp_mb__before_clear_bit();
1460 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1461 	clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1462 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1463 	clear_bit(XPRT_CLOSING, &xprt->state);
1464 	smp_mb__after_clear_bit();
1465 }
1466 
1467 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1468 {
1469 	xs_sock_reset_connection_flags(xprt);
1470 	/* Mark transport as closed and wake up all pending tasks */
1471 	xprt_disconnect_done(xprt);
1472 }
1473 
1474 /**
1475  * xs_tcp_state_change - callback to handle TCP socket state changes
1476  * @sk: socket whose state has changed
1477  *
1478  */
1479 static void xs_tcp_state_change(struct sock *sk)
1480 {
1481 	struct rpc_xprt *xprt;
1482 
1483 	read_lock_bh(&sk->sk_callback_lock);
1484 	if (!(xprt = xprt_from_sock(sk)))
1485 		goto out;
1486 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1487 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1488 			sk->sk_state, xprt_connected(xprt),
1489 			sock_flag(sk, SOCK_DEAD),
1490 			sock_flag(sk, SOCK_ZAPPED),
1491 			sk->sk_shutdown);
1492 
1493 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1494 	switch (sk->sk_state) {
1495 	case TCP_ESTABLISHED:
1496 		spin_lock(&xprt->transport_lock);
1497 		if (!xprt_test_and_set_connected(xprt)) {
1498 			struct sock_xprt *transport = container_of(xprt,
1499 					struct sock_xprt, xprt);
1500 
1501 			/* Reset TCP record info */
1502 			transport->tcp_offset = 0;
1503 			transport->tcp_reclen = 0;
1504 			transport->tcp_copied = 0;
1505 			transport->tcp_flags =
1506 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1507 			xprt->connect_cookie++;
1508 
1509 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1510 		}
1511 		spin_unlock(&xprt->transport_lock);
1512 		break;
1513 	case TCP_FIN_WAIT1:
1514 		/* The client initiated a shutdown of the socket */
1515 		xprt->connect_cookie++;
1516 		xprt->reestablish_timeout = 0;
1517 		set_bit(XPRT_CLOSING, &xprt->state);
1518 		smp_mb__before_clear_bit();
1519 		clear_bit(XPRT_CONNECTED, &xprt->state);
1520 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1521 		smp_mb__after_clear_bit();
1522 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1523 		break;
1524 	case TCP_CLOSE_WAIT:
1525 		/* The server initiated a shutdown of the socket */
1526 		xprt->connect_cookie++;
1527 		clear_bit(XPRT_CONNECTED, &xprt->state);
1528 		xs_tcp_force_close(xprt);
1529 	case TCP_CLOSING:
1530 		/*
1531 		 * If the server closed down the connection, make sure that
1532 		 * we back off before reconnecting
1533 		 */
1534 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1535 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1536 		break;
1537 	case TCP_LAST_ACK:
1538 		set_bit(XPRT_CLOSING, &xprt->state);
1539 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1540 		smp_mb__before_clear_bit();
1541 		clear_bit(XPRT_CONNECTED, &xprt->state);
1542 		smp_mb__after_clear_bit();
1543 		break;
1544 	case TCP_CLOSE:
1545 		xs_tcp_cancel_linger_timeout(xprt);
1546 		xs_sock_mark_closed(xprt);
1547 	}
1548  out:
1549 	read_unlock_bh(&sk->sk_callback_lock);
1550 }
1551 
1552 static void xs_write_space(struct sock *sk)
1553 {
1554 	struct socket *sock;
1555 	struct rpc_xprt *xprt;
1556 
1557 	if (unlikely(!(sock = sk->sk_socket)))
1558 		return;
1559 	clear_bit(SOCK_NOSPACE, &sock->flags);
1560 
1561 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1562 		return;
1563 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1564 		return;
1565 
1566 	xprt_write_space(xprt);
1567 }
1568 
1569 /**
1570  * xs_udp_write_space - callback invoked when socket buffer space
1571  *                             becomes available
1572  * @sk: socket whose state has changed
1573  *
1574  * Called when more output buffer space is available for this socket.
1575  * We try not to wake our writers until they can make "significant"
1576  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1577  * with a bunch of small requests.
1578  */
1579 static void xs_udp_write_space(struct sock *sk)
1580 {
1581 	read_lock_bh(&sk->sk_callback_lock);
1582 
1583 	/* from net/core/sock.c:sock_def_write_space */
1584 	if (sock_writeable(sk))
1585 		xs_write_space(sk);
1586 
1587 	read_unlock_bh(&sk->sk_callback_lock);
1588 }
1589 
1590 /**
1591  * xs_tcp_write_space - callback invoked when socket buffer space
1592  *                             becomes available
1593  * @sk: socket whose state has changed
1594  *
1595  * Called when more output buffer space is available for this socket.
1596  * We try not to wake our writers until they can make "significant"
1597  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1598  * with a bunch of small requests.
1599  */
1600 static void xs_tcp_write_space(struct sock *sk)
1601 {
1602 	read_lock_bh(&sk->sk_callback_lock);
1603 
1604 	/* from net/core/stream.c:sk_stream_write_space */
1605 	if (sk_stream_is_writeable(sk))
1606 		xs_write_space(sk);
1607 
1608 	read_unlock_bh(&sk->sk_callback_lock);
1609 }
1610 
1611 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1612 {
1613 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1614 	struct sock *sk = transport->inet;
1615 
1616 	if (transport->rcvsize) {
1617 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1618 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1619 	}
1620 	if (transport->sndsize) {
1621 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1622 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1623 		sk->sk_write_space(sk);
1624 	}
1625 }
1626 
1627 /**
1628  * xs_udp_set_buffer_size - set send and receive limits
1629  * @xprt: generic transport
1630  * @sndsize: requested size of send buffer, in bytes
1631  * @rcvsize: requested size of receive buffer, in bytes
1632  *
1633  * Set socket send and receive buffer size limits.
1634  */
1635 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1636 {
1637 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1638 
1639 	transport->sndsize = 0;
1640 	if (sndsize)
1641 		transport->sndsize = sndsize + 1024;
1642 	transport->rcvsize = 0;
1643 	if (rcvsize)
1644 		transport->rcvsize = rcvsize + 1024;
1645 
1646 	xs_udp_do_set_buffer_size(xprt);
1647 }
1648 
1649 /**
1650  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1651  * @task: task that timed out
1652  *
1653  * Adjust the congestion window after a retransmit timeout has occurred.
1654  */
1655 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1656 {
1657 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1658 }
1659 
1660 static unsigned short xs_get_random_port(void)
1661 {
1662 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1663 	unsigned short rand = (unsigned short) net_random() % range;
1664 	return rand + xprt_min_resvport;
1665 }
1666 
1667 /**
1668  * xs_set_port - reset the port number in the remote endpoint address
1669  * @xprt: generic transport
1670  * @port: new port number
1671  *
1672  */
1673 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1674 {
1675 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1676 
1677 	rpc_set_port(xs_addr(xprt), port);
1678 	xs_update_peer_port(xprt);
1679 }
1680 
1681 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1682 {
1683 	unsigned short port = transport->srcport;
1684 
1685 	if (port == 0 && transport->xprt.resvport)
1686 		port = xs_get_random_port();
1687 	return port;
1688 }
1689 
1690 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1691 {
1692 	if (transport->srcport != 0)
1693 		transport->srcport = 0;
1694 	if (!transport->xprt.resvport)
1695 		return 0;
1696 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1697 		return xprt_max_resvport;
1698 	return --port;
1699 }
1700 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1701 {
1702 	struct sockaddr_storage myaddr;
1703 	int err, nloop = 0;
1704 	unsigned short port = xs_get_srcport(transport);
1705 	unsigned short last;
1706 
1707 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1708 	do {
1709 		rpc_set_port((struct sockaddr *)&myaddr, port);
1710 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1711 				transport->xprt.addrlen);
1712 		if (port == 0)
1713 			break;
1714 		if (err == 0) {
1715 			transport->srcport = port;
1716 			break;
1717 		}
1718 		last = port;
1719 		port = xs_next_srcport(transport, port);
1720 		if (port > last)
1721 			nloop++;
1722 	} while (err == -EADDRINUSE && nloop != 2);
1723 
1724 	if (myaddr.ss_family == AF_INET)
1725 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1726 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1727 				port, err ? "failed" : "ok", err);
1728 	else
1729 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1730 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1731 				port, err ? "failed" : "ok", err);
1732 	return err;
1733 }
1734 
1735 /*
1736  * We don't support autobind on AF_LOCAL sockets
1737  */
1738 static void xs_local_rpcbind(struct rpc_task *task)
1739 {
1740 	rcu_read_lock();
1741 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1742 	rcu_read_unlock();
1743 }
1744 
1745 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1746 {
1747 }
1748 
1749 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1750 static struct lock_class_key xs_key[2];
1751 static struct lock_class_key xs_slock_key[2];
1752 
1753 static inline void xs_reclassify_socketu(struct socket *sock)
1754 {
1755 	struct sock *sk = sock->sk;
1756 
1757 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1758 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1759 }
1760 
1761 static inline void xs_reclassify_socket4(struct socket *sock)
1762 {
1763 	struct sock *sk = sock->sk;
1764 
1765 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1766 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1767 }
1768 
1769 static inline void xs_reclassify_socket6(struct socket *sock)
1770 {
1771 	struct sock *sk = sock->sk;
1772 
1773 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1774 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1775 }
1776 
1777 static inline void xs_reclassify_socket(int family, struct socket *sock)
1778 {
1779 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1780 	if (sock_owned_by_user(sock->sk))
1781 		return;
1782 
1783 	switch (family) {
1784 	case AF_LOCAL:
1785 		xs_reclassify_socketu(sock);
1786 		break;
1787 	case AF_INET:
1788 		xs_reclassify_socket4(sock);
1789 		break;
1790 	case AF_INET6:
1791 		xs_reclassify_socket6(sock);
1792 		break;
1793 	}
1794 }
1795 #else
1796 static inline void xs_reclassify_socketu(struct socket *sock)
1797 {
1798 }
1799 
1800 static inline void xs_reclassify_socket4(struct socket *sock)
1801 {
1802 }
1803 
1804 static inline void xs_reclassify_socket6(struct socket *sock)
1805 {
1806 }
1807 
1808 static inline void xs_reclassify_socket(int family, struct socket *sock)
1809 {
1810 }
1811 #endif
1812 
1813 static void xs_dummy_setup_socket(struct work_struct *work)
1814 {
1815 }
1816 
1817 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1818 		struct sock_xprt *transport, int family, int type, int protocol)
1819 {
1820 	struct socket *sock;
1821 	int err;
1822 
1823 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1824 	if (err < 0) {
1825 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1826 				protocol, -err);
1827 		goto out;
1828 	}
1829 	xs_reclassify_socket(family, sock);
1830 
1831 	err = xs_bind(transport, sock);
1832 	if (err) {
1833 		sock_release(sock);
1834 		goto out;
1835 	}
1836 
1837 	return sock;
1838 out:
1839 	return ERR_PTR(err);
1840 }
1841 
1842 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1843 				      struct socket *sock)
1844 {
1845 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1846 									xprt);
1847 
1848 	if (!transport->inet) {
1849 		struct sock *sk = sock->sk;
1850 
1851 		write_lock_bh(&sk->sk_callback_lock);
1852 
1853 		xs_save_old_callbacks(transport, sk);
1854 
1855 		sk->sk_user_data = xprt;
1856 		sk->sk_data_ready = xs_local_data_ready;
1857 		sk->sk_write_space = xs_udp_write_space;
1858 		sk->sk_allocation = GFP_ATOMIC;
1859 
1860 		xprt_clear_connected(xprt);
1861 
1862 		/* Reset to new socket */
1863 		transport->sock = sock;
1864 		transport->inet = sk;
1865 
1866 		write_unlock_bh(&sk->sk_callback_lock);
1867 	}
1868 
1869 	/* Tell the socket layer to start connecting... */
1870 	xprt->stat.connect_count++;
1871 	xprt->stat.connect_start = jiffies;
1872 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1873 }
1874 
1875 /**
1876  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1877  * @xprt: RPC transport to connect
1878  * @transport: socket transport to connect
1879  * @create_sock: function to create a socket of the correct type
1880  */
1881 static int xs_local_setup_socket(struct sock_xprt *transport)
1882 {
1883 	struct rpc_xprt *xprt = &transport->xprt;
1884 	struct socket *sock;
1885 	int status = -EIO;
1886 
1887 	current->flags |= PF_FSTRANS;
1888 
1889 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1890 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1891 					SOCK_STREAM, 0, &sock, 1);
1892 	if (status < 0) {
1893 		dprintk("RPC:       can't create AF_LOCAL "
1894 			"transport socket (%d).\n", -status);
1895 		goto out;
1896 	}
1897 	xs_reclassify_socketu(sock);
1898 
1899 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1900 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1901 
1902 	status = xs_local_finish_connecting(xprt, sock);
1903 	trace_rpc_socket_connect(xprt, sock, status);
1904 	switch (status) {
1905 	case 0:
1906 		dprintk("RPC:       xprt %p connected to %s\n",
1907 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1908 		xprt_set_connected(xprt);
1909 		break;
1910 	case -ENOENT:
1911 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1912 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1913 		break;
1914 	case -ECONNREFUSED:
1915 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1916 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1917 		break;
1918 	default:
1919 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1920 				__func__, -status,
1921 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1922 	}
1923 
1924 out:
1925 	xprt_clear_connecting(xprt);
1926 	xprt_wake_pending_tasks(xprt, status);
1927 	current->flags &= ~PF_FSTRANS;
1928 	return status;
1929 }
1930 
1931 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1932 {
1933 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1934 	int ret;
1935 
1936 	 if (RPC_IS_ASYNC(task)) {
1937 		/*
1938 		 * We want the AF_LOCAL connect to be resolved in the
1939 		 * filesystem namespace of the process making the rpc
1940 		 * call.  Thus we connect synchronously.
1941 		 *
1942 		 * If we want to support asynchronous AF_LOCAL calls,
1943 		 * we'll need to figure out how to pass a namespace to
1944 		 * connect.
1945 		 */
1946 		rpc_exit(task, -ENOTCONN);
1947 		return;
1948 	}
1949 	ret = xs_local_setup_socket(transport);
1950 	if (ret && !RPC_IS_SOFTCONN(task))
1951 		msleep_interruptible(15000);
1952 }
1953 
1954 #ifdef CONFIG_SUNRPC_SWAP
1955 static void xs_set_memalloc(struct rpc_xprt *xprt)
1956 {
1957 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1958 			xprt);
1959 
1960 	if (xprt->swapper)
1961 		sk_set_memalloc(transport->inet);
1962 }
1963 
1964 /**
1965  * xs_swapper - Tag this transport as being used for swap.
1966  * @xprt: transport to tag
1967  * @enable: enable/disable
1968  *
1969  */
1970 int xs_swapper(struct rpc_xprt *xprt, int enable)
1971 {
1972 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1973 			xprt);
1974 	int err = 0;
1975 
1976 	if (enable) {
1977 		xprt->swapper++;
1978 		xs_set_memalloc(xprt);
1979 	} else if (xprt->swapper) {
1980 		xprt->swapper--;
1981 		sk_clear_memalloc(transport->inet);
1982 	}
1983 
1984 	return err;
1985 }
1986 EXPORT_SYMBOL_GPL(xs_swapper);
1987 #else
1988 static void xs_set_memalloc(struct rpc_xprt *xprt)
1989 {
1990 }
1991 #endif
1992 
1993 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1994 {
1995 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1996 
1997 	if (!transport->inet) {
1998 		struct sock *sk = sock->sk;
1999 
2000 		write_lock_bh(&sk->sk_callback_lock);
2001 
2002 		xs_save_old_callbacks(transport, sk);
2003 
2004 		sk->sk_user_data = xprt;
2005 		sk->sk_data_ready = xs_udp_data_ready;
2006 		sk->sk_write_space = xs_udp_write_space;
2007 		sk->sk_no_check = UDP_CSUM_NORCV;
2008 		sk->sk_allocation = GFP_ATOMIC;
2009 
2010 		xprt_set_connected(xprt);
2011 
2012 		/* Reset to new socket */
2013 		transport->sock = sock;
2014 		transport->inet = sk;
2015 
2016 		xs_set_memalloc(xprt);
2017 
2018 		write_unlock_bh(&sk->sk_callback_lock);
2019 	}
2020 	xs_udp_do_set_buffer_size(xprt);
2021 }
2022 
2023 static void xs_udp_setup_socket(struct work_struct *work)
2024 {
2025 	struct sock_xprt *transport =
2026 		container_of(work, struct sock_xprt, connect_worker.work);
2027 	struct rpc_xprt *xprt = &transport->xprt;
2028 	struct socket *sock = transport->sock;
2029 	int status = -EIO;
2030 
2031 	current->flags |= PF_FSTRANS;
2032 
2033 	/* Start by resetting any existing state */
2034 	xs_reset_transport(transport);
2035 	sock = xs_create_sock(xprt, transport,
2036 			xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2037 	if (IS_ERR(sock))
2038 		goto out;
2039 
2040 	dprintk("RPC:       worker connecting xprt %p via %s to "
2041 				"%s (port %s)\n", xprt,
2042 			xprt->address_strings[RPC_DISPLAY_PROTO],
2043 			xprt->address_strings[RPC_DISPLAY_ADDR],
2044 			xprt->address_strings[RPC_DISPLAY_PORT]);
2045 
2046 	xs_udp_finish_connecting(xprt, sock);
2047 	trace_rpc_socket_connect(xprt, sock, 0);
2048 	status = 0;
2049 out:
2050 	xprt_clear_connecting(xprt);
2051 	xprt_wake_pending_tasks(xprt, status);
2052 	current->flags &= ~PF_FSTRANS;
2053 }
2054 
2055 /*
2056  * We need to preserve the port number so the reply cache on the server can
2057  * find our cached RPC replies when we get around to reconnecting.
2058  */
2059 static void xs_abort_connection(struct sock_xprt *transport)
2060 {
2061 	int result;
2062 	struct sockaddr any;
2063 
2064 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2065 
2066 	/*
2067 	 * Disconnect the transport socket by doing a connect operation
2068 	 * with AF_UNSPEC.  This should return immediately...
2069 	 */
2070 	memset(&any, 0, sizeof(any));
2071 	any.sa_family = AF_UNSPEC;
2072 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2073 	trace_rpc_socket_reset_connection(&transport->xprt,
2074 			transport->sock, result);
2075 	if (!result)
2076 		xs_sock_reset_connection_flags(&transport->xprt);
2077 	dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2078 }
2079 
2080 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2081 {
2082 	unsigned int state = transport->inet->sk_state;
2083 
2084 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2085 		/* we don't need to abort the connection if the socket
2086 		 * hasn't undergone a shutdown
2087 		 */
2088 		if (transport->inet->sk_shutdown == 0)
2089 			return;
2090 		dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2091 				__func__, transport->inet->sk_shutdown);
2092 	}
2093 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2094 		/* we don't need to abort the connection if the socket
2095 		 * hasn't undergone a shutdown
2096 		 */
2097 		if (transport->inet->sk_shutdown == 0)
2098 			return;
2099 		dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2100 				"sk_shutdown set to %d\n",
2101 				__func__, transport->inet->sk_shutdown);
2102 	}
2103 	xs_abort_connection(transport);
2104 }
2105 
2106 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2107 {
2108 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2109 	int ret = -ENOTCONN;
2110 
2111 	if (!transport->inet) {
2112 		struct sock *sk = sock->sk;
2113 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2114 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2115 		unsigned int opt_on = 1;
2116 
2117 		/* TCP Keepalive options */
2118 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2119 				(char *)&opt_on, sizeof(opt_on));
2120 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2121 				(char *)&keepidle, sizeof(keepidle));
2122 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2123 				(char *)&keepidle, sizeof(keepidle));
2124 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2125 				(char *)&keepcnt, sizeof(keepcnt));
2126 
2127 		write_lock_bh(&sk->sk_callback_lock);
2128 
2129 		xs_save_old_callbacks(transport, sk);
2130 
2131 		sk->sk_user_data = xprt;
2132 		sk->sk_data_ready = xs_tcp_data_ready;
2133 		sk->sk_state_change = xs_tcp_state_change;
2134 		sk->sk_write_space = xs_tcp_write_space;
2135 		sk->sk_allocation = GFP_ATOMIC;
2136 
2137 		/* socket options */
2138 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2139 		sock_reset_flag(sk, SOCK_LINGER);
2140 		tcp_sk(sk)->linger2 = 0;
2141 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2142 
2143 		xprt_clear_connected(xprt);
2144 
2145 		/* Reset to new socket */
2146 		transport->sock = sock;
2147 		transport->inet = sk;
2148 
2149 		write_unlock_bh(&sk->sk_callback_lock);
2150 	}
2151 
2152 	if (!xprt_bound(xprt))
2153 		goto out;
2154 
2155 	xs_set_memalloc(xprt);
2156 
2157 	/* Tell the socket layer to start connecting... */
2158 	xprt->stat.connect_count++;
2159 	xprt->stat.connect_start = jiffies;
2160 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2161 	switch (ret) {
2162 	case 0:
2163 	case -EINPROGRESS:
2164 		/* SYN_SENT! */
2165 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2166 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2167 	}
2168 out:
2169 	return ret;
2170 }
2171 
2172 /**
2173  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2174  * @xprt: RPC transport to connect
2175  * @transport: socket transport to connect
2176  * @create_sock: function to create a socket of the correct type
2177  *
2178  * Invoked by a work queue tasklet.
2179  */
2180 static void xs_tcp_setup_socket(struct work_struct *work)
2181 {
2182 	struct sock_xprt *transport =
2183 		container_of(work, struct sock_xprt, connect_worker.work);
2184 	struct socket *sock = transport->sock;
2185 	struct rpc_xprt *xprt = &transport->xprt;
2186 	int status = -EIO;
2187 
2188 	current->flags |= PF_FSTRANS;
2189 
2190 	if (!sock) {
2191 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2192 		sock = xs_create_sock(xprt, transport,
2193 				xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2194 		if (IS_ERR(sock)) {
2195 			status = PTR_ERR(sock);
2196 			goto out;
2197 		}
2198 	} else {
2199 		int abort_and_exit;
2200 
2201 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2202 				&xprt->state);
2203 		/* "close" the socket, preserving the local port */
2204 		xs_tcp_reuse_connection(transport);
2205 
2206 		if (abort_and_exit)
2207 			goto out_eagain;
2208 	}
2209 
2210 	dprintk("RPC:       worker connecting xprt %p via %s to "
2211 				"%s (port %s)\n", xprt,
2212 			xprt->address_strings[RPC_DISPLAY_PROTO],
2213 			xprt->address_strings[RPC_DISPLAY_ADDR],
2214 			xprt->address_strings[RPC_DISPLAY_PORT]);
2215 
2216 	status = xs_tcp_finish_connecting(xprt, sock);
2217 	trace_rpc_socket_connect(xprt, sock, status);
2218 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2219 			xprt, -status, xprt_connected(xprt),
2220 			sock->sk->sk_state);
2221 	switch (status) {
2222 	default:
2223 		printk("%s: connect returned unhandled error %d\n",
2224 			__func__, status);
2225 	case -EADDRNOTAVAIL:
2226 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2227 		 * and retry
2228 		 */
2229 		xs_tcp_force_close(xprt);
2230 		break;
2231 	case 0:
2232 	case -EINPROGRESS:
2233 	case -EALREADY:
2234 		xprt_clear_connecting(xprt);
2235 		current->flags &= ~PF_FSTRANS;
2236 		return;
2237 	case -EINVAL:
2238 		/* Happens, for instance, if the user specified a link
2239 		 * local IPv6 address without a scope-id.
2240 		 */
2241 	case -ECONNREFUSED:
2242 	case -ECONNRESET:
2243 	case -ENETUNREACH:
2244 		/* retry with existing socket, after a delay */
2245 		goto out;
2246 	}
2247 out_eagain:
2248 	status = -EAGAIN;
2249 out:
2250 	xprt_clear_connecting(xprt);
2251 	xprt_wake_pending_tasks(xprt, status);
2252 	current->flags &= ~PF_FSTRANS;
2253 }
2254 
2255 /**
2256  * xs_connect - connect a socket to a remote endpoint
2257  * @xprt: pointer to transport structure
2258  * @task: address of RPC task that manages state of connect request
2259  *
2260  * TCP: If the remote end dropped the connection, delay reconnecting.
2261  *
2262  * UDP socket connects are synchronous, but we use a work queue anyway
2263  * to guarantee that even unprivileged user processes can set up a
2264  * socket on a privileged port.
2265  *
2266  * If a UDP socket connect fails, the delay behavior here prevents
2267  * retry floods (hard mounts).
2268  */
2269 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2270 {
2271 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2272 
2273 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2274 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2275 				"seconds\n",
2276 				xprt, xprt->reestablish_timeout / HZ);
2277 		queue_delayed_work(rpciod_workqueue,
2278 				   &transport->connect_worker,
2279 				   xprt->reestablish_timeout);
2280 		xprt->reestablish_timeout <<= 1;
2281 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2282 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2283 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2284 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2285 	} else {
2286 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2287 		queue_delayed_work(rpciod_workqueue,
2288 				   &transport->connect_worker, 0);
2289 	}
2290 }
2291 
2292 /**
2293  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2294  * @xprt: rpc_xprt struct containing statistics
2295  * @seq: output file
2296  *
2297  */
2298 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2299 {
2300 	long idle_time = 0;
2301 
2302 	if (xprt_connected(xprt))
2303 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2304 
2305 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2306 			"%llu %llu %lu %llu %llu\n",
2307 			xprt->stat.bind_count,
2308 			xprt->stat.connect_count,
2309 			xprt->stat.connect_time,
2310 			idle_time,
2311 			xprt->stat.sends,
2312 			xprt->stat.recvs,
2313 			xprt->stat.bad_xids,
2314 			xprt->stat.req_u,
2315 			xprt->stat.bklog_u,
2316 			xprt->stat.max_slots,
2317 			xprt->stat.sending_u,
2318 			xprt->stat.pending_u);
2319 }
2320 
2321 /**
2322  * xs_udp_print_stats - display UDP socket-specifc stats
2323  * @xprt: rpc_xprt struct containing statistics
2324  * @seq: output file
2325  *
2326  */
2327 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2328 {
2329 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2330 
2331 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2332 			"%lu %llu %llu\n",
2333 			transport->srcport,
2334 			xprt->stat.bind_count,
2335 			xprt->stat.sends,
2336 			xprt->stat.recvs,
2337 			xprt->stat.bad_xids,
2338 			xprt->stat.req_u,
2339 			xprt->stat.bklog_u,
2340 			xprt->stat.max_slots,
2341 			xprt->stat.sending_u,
2342 			xprt->stat.pending_u);
2343 }
2344 
2345 /**
2346  * xs_tcp_print_stats - display TCP socket-specifc stats
2347  * @xprt: rpc_xprt struct containing statistics
2348  * @seq: output file
2349  *
2350  */
2351 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2352 {
2353 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2354 	long idle_time = 0;
2355 
2356 	if (xprt_connected(xprt))
2357 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2358 
2359 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2360 			"%llu %llu %lu %llu %llu\n",
2361 			transport->srcport,
2362 			xprt->stat.bind_count,
2363 			xprt->stat.connect_count,
2364 			xprt->stat.connect_time,
2365 			idle_time,
2366 			xprt->stat.sends,
2367 			xprt->stat.recvs,
2368 			xprt->stat.bad_xids,
2369 			xprt->stat.req_u,
2370 			xprt->stat.bklog_u,
2371 			xprt->stat.max_slots,
2372 			xprt->stat.sending_u,
2373 			xprt->stat.pending_u);
2374 }
2375 
2376 /*
2377  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2378  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2379  * to use the server side send routines.
2380  */
2381 static void *bc_malloc(struct rpc_task *task, size_t size)
2382 {
2383 	struct page *page;
2384 	struct rpc_buffer *buf;
2385 
2386 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2387 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2388 		return NULL;
2389 
2390 	page = alloc_page(GFP_KERNEL);
2391 	if (!page)
2392 		return NULL;
2393 
2394 	buf = page_address(page);
2395 	buf->len = PAGE_SIZE;
2396 
2397 	return buf->data;
2398 }
2399 
2400 /*
2401  * Free the space allocated in the bc_alloc routine
2402  */
2403 static void bc_free(void *buffer)
2404 {
2405 	struct rpc_buffer *buf;
2406 
2407 	if (!buffer)
2408 		return;
2409 
2410 	buf = container_of(buffer, struct rpc_buffer, data);
2411 	free_page((unsigned long)buf);
2412 }
2413 
2414 /*
2415  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2416  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2417  */
2418 static int bc_sendto(struct rpc_rqst *req)
2419 {
2420 	int len;
2421 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2422 	struct rpc_xprt *xprt = req->rq_xprt;
2423 	struct sock_xprt *transport =
2424 				container_of(xprt, struct sock_xprt, xprt);
2425 	struct socket *sock = transport->sock;
2426 	unsigned long headoff;
2427 	unsigned long tailoff;
2428 
2429 	xs_encode_stream_record_marker(xbufp);
2430 
2431 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2432 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2433 	len = svc_send_common(sock, xbufp,
2434 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2435 			      xbufp->tail[0].iov_base, tailoff);
2436 
2437 	if (len != xbufp->len) {
2438 		printk(KERN_NOTICE "Error sending entire callback!\n");
2439 		len = -EAGAIN;
2440 	}
2441 
2442 	return len;
2443 }
2444 
2445 /*
2446  * The send routine. Borrows from svc_send
2447  */
2448 static int bc_send_request(struct rpc_task *task)
2449 {
2450 	struct rpc_rqst *req = task->tk_rqstp;
2451 	struct svc_xprt	*xprt;
2452 	u32                     len;
2453 
2454 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2455 	/*
2456 	 * Get the server socket associated with this callback xprt
2457 	 */
2458 	xprt = req->rq_xprt->bc_xprt;
2459 
2460 	/*
2461 	 * Grab the mutex to serialize data as the connection is shared
2462 	 * with the fore channel
2463 	 */
2464 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2465 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2466 		if (!mutex_trylock(&xprt->xpt_mutex))
2467 			return -EAGAIN;
2468 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2469 	}
2470 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2471 		len = -ENOTCONN;
2472 	else
2473 		len = bc_sendto(req);
2474 	mutex_unlock(&xprt->xpt_mutex);
2475 
2476 	if (len > 0)
2477 		len = 0;
2478 
2479 	return len;
2480 }
2481 
2482 /*
2483  * The close routine. Since this is client initiated, we do nothing
2484  */
2485 
2486 static void bc_close(struct rpc_xprt *xprt)
2487 {
2488 }
2489 
2490 /*
2491  * The xprt destroy routine. Again, because this connection is client
2492  * initiated, we do nothing
2493  */
2494 
2495 static void bc_destroy(struct rpc_xprt *xprt)
2496 {
2497 }
2498 
2499 static struct rpc_xprt_ops xs_local_ops = {
2500 	.reserve_xprt		= xprt_reserve_xprt,
2501 	.release_xprt		= xs_tcp_release_xprt,
2502 	.alloc_slot		= xprt_alloc_slot,
2503 	.rpcbind		= xs_local_rpcbind,
2504 	.set_port		= xs_local_set_port,
2505 	.connect		= xs_local_connect,
2506 	.buf_alloc		= rpc_malloc,
2507 	.buf_free		= rpc_free,
2508 	.send_request		= xs_local_send_request,
2509 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2510 	.close			= xs_close,
2511 	.destroy		= xs_destroy,
2512 	.print_stats		= xs_local_print_stats,
2513 };
2514 
2515 static struct rpc_xprt_ops xs_udp_ops = {
2516 	.set_buffer_size	= xs_udp_set_buffer_size,
2517 	.reserve_xprt		= xprt_reserve_xprt_cong,
2518 	.release_xprt		= xprt_release_xprt_cong,
2519 	.alloc_slot		= xprt_alloc_slot,
2520 	.rpcbind		= rpcb_getport_async,
2521 	.set_port		= xs_set_port,
2522 	.connect		= xs_connect,
2523 	.buf_alloc		= rpc_malloc,
2524 	.buf_free		= rpc_free,
2525 	.send_request		= xs_udp_send_request,
2526 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2527 	.timer			= xs_udp_timer,
2528 	.release_request	= xprt_release_rqst_cong,
2529 	.close			= xs_close,
2530 	.destroy		= xs_destroy,
2531 	.print_stats		= xs_udp_print_stats,
2532 };
2533 
2534 static struct rpc_xprt_ops xs_tcp_ops = {
2535 	.reserve_xprt		= xprt_reserve_xprt,
2536 	.release_xprt		= xs_tcp_release_xprt,
2537 	.alloc_slot		= xprt_lock_and_alloc_slot,
2538 	.rpcbind		= rpcb_getport_async,
2539 	.set_port		= xs_set_port,
2540 	.connect		= xs_connect,
2541 	.buf_alloc		= rpc_malloc,
2542 	.buf_free		= rpc_free,
2543 	.send_request		= xs_tcp_send_request,
2544 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2545 	.close			= xs_tcp_close,
2546 	.destroy		= xs_destroy,
2547 	.print_stats		= xs_tcp_print_stats,
2548 };
2549 
2550 /*
2551  * The rpc_xprt_ops for the server backchannel
2552  */
2553 
2554 static struct rpc_xprt_ops bc_tcp_ops = {
2555 	.reserve_xprt		= xprt_reserve_xprt,
2556 	.release_xprt		= xprt_release_xprt,
2557 	.alloc_slot		= xprt_alloc_slot,
2558 	.buf_alloc		= bc_malloc,
2559 	.buf_free		= bc_free,
2560 	.send_request		= bc_send_request,
2561 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2562 	.close			= bc_close,
2563 	.destroy		= bc_destroy,
2564 	.print_stats		= xs_tcp_print_stats,
2565 };
2566 
2567 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2568 {
2569 	static const struct sockaddr_in sin = {
2570 		.sin_family		= AF_INET,
2571 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2572 	};
2573 	static const struct sockaddr_in6 sin6 = {
2574 		.sin6_family		= AF_INET6,
2575 		.sin6_addr		= IN6ADDR_ANY_INIT,
2576 	};
2577 
2578 	switch (family) {
2579 	case AF_LOCAL:
2580 		break;
2581 	case AF_INET:
2582 		memcpy(sap, &sin, sizeof(sin));
2583 		break;
2584 	case AF_INET6:
2585 		memcpy(sap, &sin6, sizeof(sin6));
2586 		break;
2587 	default:
2588 		dprintk("RPC:       %s: Bad address family\n", __func__);
2589 		return -EAFNOSUPPORT;
2590 	}
2591 	return 0;
2592 }
2593 
2594 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2595 				      unsigned int slot_table_size,
2596 				      unsigned int max_slot_table_size)
2597 {
2598 	struct rpc_xprt *xprt;
2599 	struct sock_xprt *new;
2600 
2601 	if (args->addrlen > sizeof(xprt->addr)) {
2602 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2603 		return ERR_PTR(-EBADF);
2604 	}
2605 
2606 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2607 			max_slot_table_size);
2608 	if (xprt == NULL) {
2609 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2610 				"rpc_xprt\n");
2611 		return ERR_PTR(-ENOMEM);
2612 	}
2613 
2614 	new = container_of(xprt, struct sock_xprt, xprt);
2615 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2616 	xprt->addrlen = args->addrlen;
2617 	if (args->srcaddr)
2618 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2619 	else {
2620 		int err;
2621 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2622 					(struct sockaddr *)&new->srcaddr);
2623 		if (err != 0) {
2624 			xprt_free(xprt);
2625 			return ERR_PTR(err);
2626 		}
2627 	}
2628 
2629 	return xprt;
2630 }
2631 
2632 static const struct rpc_timeout xs_local_default_timeout = {
2633 	.to_initval = 10 * HZ,
2634 	.to_maxval = 10 * HZ,
2635 	.to_retries = 2,
2636 };
2637 
2638 /**
2639  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2640  * @args: rpc transport creation arguments
2641  *
2642  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2643  */
2644 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2645 {
2646 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2647 	struct sock_xprt *transport;
2648 	struct rpc_xprt *xprt;
2649 	struct rpc_xprt *ret;
2650 
2651 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2652 			xprt_max_tcp_slot_table_entries);
2653 	if (IS_ERR(xprt))
2654 		return xprt;
2655 	transport = container_of(xprt, struct sock_xprt, xprt);
2656 
2657 	xprt->prot = 0;
2658 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2659 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2660 
2661 	xprt->bind_timeout = XS_BIND_TO;
2662 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2663 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2664 
2665 	xprt->ops = &xs_local_ops;
2666 	xprt->timeout = &xs_local_default_timeout;
2667 
2668 	INIT_DELAYED_WORK(&transport->connect_worker,
2669 			xs_dummy_setup_socket);
2670 
2671 	switch (sun->sun_family) {
2672 	case AF_LOCAL:
2673 		if (sun->sun_path[0] != '/') {
2674 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2675 					sun->sun_path);
2676 			ret = ERR_PTR(-EINVAL);
2677 			goto out_err;
2678 		}
2679 		xprt_set_bound(xprt);
2680 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2681 		ret = ERR_PTR(xs_local_setup_socket(transport));
2682 		if (ret)
2683 			goto out_err;
2684 		break;
2685 	default:
2686 		ret = ERR_PTR(-EAFNOSUPPORT);
2687 		goto out_err;
2688 	}
2689 
2690 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2691 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2692 
2693 	if (try_module_get(THIS_MODULE))
2694 		return xprt;
2695 	ret = ERR_PTR(-EINVAL);
2696 out_err:
2697 	xprt_free(xprt);
2698 	return ret;
2699 }
2700 
2701 static const struct rpc_timeout xs_udp_default_timeout = {
2702 	.to_initval = 5 * HZ,
2703 	.to_maxval = 30 * HZ,
2704 	.to_increment = 5 * HZ,
2705 	.to_retries = 5,
2706 };
2707 
2708 /**
2709  * xs_setup_udp - Set up transport to use a UDP socket
2710  * @args: rpc transport creation arguments
2711  *
2712  */
2713 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2714 {
2715 	struct sockaddr *addr = args->dstaddr;
2716 	struct rpc_xprt *xprt;
2717 	struct sock_xprt *transport;
2718 	struct rpc_xprt *ret;
2719 
2720 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2721 			xprt_udp_slot_table_entries);
2722 	if (IS_ERR(xprt))
2723 		return xprt;
2724 	transport = container_of(xprt, struct sock_xprt, xprt);
2725 
2726 	xprt->prot = IPPROTO_UDP;
2727 	xprt->tsh_size = 0;
2728 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2729 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2730 
2731 	xprt->bind_timeout = XS_BIND_TO;
2732 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2733 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2734 
2735 	xprt->ops = &xs_udp_ops;
2736 
2737 	xprt->timeout = &xs_udp_default_timeout;
2738 
2739 	switch (addr->sa_family) {
2740 	case AF_INET:
2741 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2742 			xprt_set_bound(xprt);
2743 
2744 		INIT_DELAYED_WORK(&transport->connect_worker,
2745 					xs_udp_setup_socket);
2746 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2747 		break;
2748 	case AF_INET6:
2749 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2750 			xprt_set_bound(xprt);
2751 
2752 		INIT_DELAYED_WORK(&transport->connect_worker,
2753 					xs_udp_setup_socket);
2754 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2755 		break;
2756 	default:
2757 		ret = ERR_PTR(-EAFNOSUPPORT);
2758 		goto out_err;
2759 	}
2760 
2761 	if (xprt_bound(xprt))
2762 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2763 				xprt->address_strings[RPC_DISPLAY_ADDR],
2764 				xprt->address_strings[RPC_DISPLAY_PORT],
2765 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2766 	else
2767 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2768 				xprt->address_strings[RPC_DISPLAY_ADDR],
2769 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2770 
2771 	if (try_module_get(THIS_MODULE))
2772 		return xprt;
2773 	ret = ERR_PTR(-EINVAL);
2774 out_err:
2775 	xprt_free(xprt);
2776 	return ret;
2777 }
2778 
2779 static const struct rpc_timeout xs_tcp_default_timeout = {
2780 	.to_initval = 60 * HZ,
2781 	.to_maxval = 60 * HZ,
2782 	.to_retries = 2,
2783 };
2784 
2785 /**
2786  * xs_setup_tcp - Set up transport to use a TCP socket
2787  * @args: rpc transport creation arguments
2788  *
2789  */
2790 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2791 {
2792 	struct sockaddr *addr = args->dstaddr;
2793 	struct rpc_xprt *xprt;
2794 	struct sock_xprt *transport;
2795 	struct rpc_xprt *ret;
2796 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2797 
2798 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2799 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2800 
2801 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2802 			max_slot_table_size);
2803 	if (IS_ERR(xprt))
2804 		return xprt;
2805 	transport = container_of(xprt, struct sock_xprt, xprt);
2806 
2807 	xprt->prot = IPPROTO_TCP;
2808 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2809 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2810 
2811 	xprt->bind_timeout = XS_BIND_TO;
2812 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2813 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2814 
2815 	xprt->ops = &xs_tcp_ops;
2816 	xprt->timeout = &xs_tcp_default_timeout;
2817 
2818 	switch (addr->sa_family) {
2819 	case AF_INET:
2820 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2821 			xprt_set_bound(xprt);
2822 
2823 		INIT_DELAYED_WORK(&transport->connect_worker,
2824 					xs_tcp_setup_socket);
2825 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2826 		break;
2827 	case AF_INET6:
2828 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2829 			xprt_set_bound(xprt);
2830 
2831 		INIT_DELAYED_WORK(&transport->connect_worker,
2832 					xs_tcp_setup_socket);
2833 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2834 		break;
2835 	default:
2836 		ret = ERR_PTR(-EAFNOSUPPORT);
2837 		goto out_err;
2838 	}
2839 
2840 	if (xprt_bound(xprt))
2841 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2842 				xprt->address_strings[RPC_DISPLAY_ADDR],
2843 				xprt->address_strings[RPC_DISPLAY_PORT],
2844 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2845 	else
2846 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2847 				xprt->address_strings[RPC_DISPLAY_ADDR],
2848 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2849 
2850 
2851 	if (try_module_get(THIS_MODULE))
2852 		return xprt;
2853 	ret = ERR_PTR(-EINVAL);
2854 out_err:
2855 	xprt_free(xprt);
2856 	return ret;
2857 }
2858 
2859 /**
2860  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2861  * @args: rpc transport creation arguments
2862  *
2863  */
2864 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2865 {
2866 	struct sockaddr *addr = args->dstaddr;
2867 	struct rpc_xprt *xprt;
2868 	struct sock_xprt *transport;
2869 	struct svc_sock *bc_sock;
2870 	struct rpc_xprt *ret;
2871 
2872 	if (args->bc_xprt->xpt_bc_xprt) {
2873 		/*
2874 		 * This server connection already has a backchannel
2875 		 * transport; we can't create a new one, as we wouldn't
2876 		 * be able to match replies based on xid any more.  So,
2877 		 * reuse the already-existing one:
2878 		 */
2879 		 return args->bc_xprt->xpt_bc_xprt;
2880 	}
2881 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2882 			xprt_tcp_slot_table_entries);
2883 	if (IS_ERR(xprt))
2884 		return xprt;
2885 	transport = container_of(xprt, struct sock_xprt, xprt);
2886 
2887 	xprt->prot = IPPROTO_TCP;
2888 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2889 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2890 	xprt->timeout = &xs_tcp_default_timeout;
2891 
2892 	/* backchannel */
2893 	xprt_set_bound(xprt);
2894 	xprt->bind_timeout = 0;
2895 	xprt->reestablish_timeout = 0;
2896 	xprt->idle_timeout = 0;
2897 
2898 	xprt->ops = &bc_tcp_ops;
2899 
2900 	switch (addr->sa_family) {
2901 	case AF_INET:
2902 		xs_format_peer_addresses(xprt, "tcp",
2903 					 RPCBIND_NETID_TCP);
2904 		break;
2905 	case AF_INET6:
2906 		xs_format_peer_addresses(xprt, "tcp",
2907 				   RPCBIND_NETID_TCP6);
2908 		break;
2909 	default:
2910 		ret = ERR_PTR(-EAFNOSUPPORT);
2911 		goto out_err;
2912 	}
2913 
2914 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2915 			xprt->address_strings[RPC_DISPLAY_ADDR],
2916 			xprt->address_strings[RPC_DISPLAY_PORT],
2917 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2918 
2919 	/*
2920 	 * Once we've associated a backchannel xprt with a connection,
2921 	 * we want to keep it around as long as long as the connection
2922 	 * lasts, in case we need to start using it for a backchannel
2923 	 * again; this reference won't be dropped until bc_xprt is
2924 	 * destroyed.
2925 	 */
2926 	xprt_get(xprt);
2927 	args->bc_xprt->xpt_bc_xprt = xprt;
2928 	xprt->bc_xprt = args->bc_xprt;
2929 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2930 	transport->sock = bc_sock->sk_sock;
2931 	transport->inet = bc_sock->sk_sk;
2932 
2933 	/*
2934 	 * Since we don't want connections for the backchannel, we set
2935 	 * the xprt status to connected
2936 	 */
2937 	xprt_set_connected(xprt);
2938 
2939 
2940 	if (try_module_get(THIS_MODULE))
2941 		return xprt;
2942 	xprt_put(xprt);
2943 	ret = ERR_PTR(-EINVAL);
2944 out_err:
2945 	xprt_free(xprt);
2946 	return ret;
2947 }
2948 
2949 static struct xprt_class	xs_local_transport = {
2950 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2951 	.name		= "named UNIX socket",
2952 	.owner		= THIS_MODULE,
2953 	.ident		= XPRT_TRANSPORT_LOCAL,
2954 	.setup		= xs_setup_local,
2955 };
2956 
2957 static struct xprt_class	xs_udp_transport = {
2958 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2959 	.name		= "udp",
2960 	.owner		= THIS_MODULE,
2961 	.ident		= XPRT_TRANSPORT_UDP,
2962 	.setup		= xs_setup_udp,
2963 };
2964 
2965 static struct xprt_class	xs_tcp_transport = {
2966 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2967 	.name		= "tcp",
2968 	.owner		= THIS_MODULE,
2969 	.ident		= XPRT_TRANSPORT_TCP,
2970 	.setup		= xs_setup_tcp,
2971 };
2972 
2973 static struct xprt_class	xs_bc_tcp_transport = {
2974 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2975 	.name		= "tcp NFSv4.1 backchannel",
2976 	.owner		= THIS_MODULE,
2977 	.ident		= XPRT_TRANSPORT_BC_TCP,
2978 	.setup		= xs_setup_bc_tcp,
2979 };
2980 
2981 /**
2982  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2983  *
2984  */
2985 int init_socket_xprt(void)
2986 {
2987 #ifdef RPC_DEBUG
2988 	if (!sunrpc_table_header)
2989 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2990 #endif
2991 
2992 	xprt_register_transport(&xs_local_transport);
2993 	xprt_register_transport(&xs_udp_transport);
2994 	xprt_register_transport(&xs_tcp_transport);
2995 	xprt_register_transport(&xs_bc_tcp_transport);
2996 
2997 	return 0;
2998 }
2999 
3000 /**
3001  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3002  *
3003  */
3004 void cleanup_socket_xprt(void)
3005 {
3006 #ifdef RPC_DEBUG
3007 	if (sunrpc_table_header) {
3008 		unregister_sysctl_table(sunrpc_table_header);
3009 		sunrpc_table_header = NULL;
3010 	}
3011 #endif
3012 
3013 	xprt_unregister_transport(&xs_local_transport);
3014 	xprt_unregister_transport(&xs_udp_transport);
3015 	xprt_unregister_transport(&xs_tcp_transport);
3016 	xprt_unregister_transport(&xs_bc_tcp_transport);
3017 }
3018 
3019 static int param_set_uint_minmax(const char *val,
3020 		const struct kernel_param *kp,
3021 		unsigned int min, unsigned int max)
3022 {
3023 	unsigned long num;
3024 	int ret;
3025 
3026 	if (!val)
3027 		return -EINVAL;
3028 	ret = strict_strtoul(val, 0, &num);
3029 	if (ret == -EINVAL || num < min || num > max)
3030 		return -EINVAL;
3031 	*((unsigned int *)kp->arg) = num;
3032 	return 0;
3033 }
3034 
3035 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3036 {
3037 	return param_set_uint_minmax(val, kp,
3038 			RPC_MIN_RESVPORT,
3039 			RPC_MAX_RESVPORT);
3040 }
3041 
3042 static struct kernel_param_ops param_ops_portnr = {
3043 	.set = param_set_portnr,
3044 	.get = param_get_uint,
3045 };
3046 
3047 #define param_check_portnr(name, p) \
3048 	__param_check(name, p, unsigned int);
3049 
3050 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3051 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3052 
3053 static int param_set_slot_table_size(const char *val,
3054 				     const struct kernel_param *kp)
3055 {
3056 	return param_set_uint_minmax(val, kp,
3057 			RPC_MIN_SLOT_TABLE,
3058 			RPC_MAX_SLOT_TABLE);
3059 }
3060 
3061 static struct kernel_param_ops param_ops_slot_table_size = {
3062 	.set = param_set_slot_table_size,
3063 	.get = param_get_uint,
3064 };
3065 
3066 #define param_check_slot_table_size(name, p) \
3067 	__param_check(name, p, unsigned int);
3068 
3069 static int param_set_max_slot_table_size(const char *val,
3070 				     const struct kernel_param *kp)
3071 {
3072 	return param_set_uint_minmax(val, kp,
3073 			RPC_MIN_SLOT_TABLE,
3074 			RPC_MAX_SLOT_TABLE_LIMIT);
3075 }
3076 
3077 static struct kernel_param_ops param_ops_max_slot_table_size = {
3078 	.set = param_set_max_slot_table_size,
3079 	.get = param_get_uint,
3080 };
3081 
3082 #define param_check_max_slot_table_size(name, p) \
3083 	__param_check(name, p, unsigned int);
3084 
3085 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3086 		   slot_table_size, 0644);
3087 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3088 		   max_slot_table_size, 0644);
3089 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3090 		   slot_table_size, 0644);
3091 
3092