xref: /openbmc/linux/net/sunrpc/xprtsock.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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/slab.h>
23 #include <linux/module.h>
24 #include <linux/capability.h>
25 #include <linux/pagemap.h>
26 #include <linux/errno.h>
27 #include <linux/socket.h>
28 #include <linux/in.h>
29 #include <linux/net.h>
30 #include <linux/mm.h>
31 #include <linux/udp.h>
32 #include <linux/tcp.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/sched.h>
35 #include <linux/sunrpc/xprtsock.h>
36 #include <linux/file.h>
37 
38 #include <net/sock.h>
39 #include <net/checksum.h>
40 #include <net/udp.h>
41 #include <net/tcp.h>
42 
43 /*
44  * xprtsock tunables
45  */
46 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
47 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
48 
49 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
50 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
51 
52 #define XS_TCP_LINGER_TO	(15U * HZ)
53 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
54 
55 /*
56  * We can register our own files under /proc/sys/sunrpc by
57  * calling register_sysctl_table() again.  The files in that
58  * directory become the union of all files registered there.
59  *
60  * We simply need to make sure that we don't collide with
61  * someone else's file names!
62  */
63 
64 #ifdef RPC_DEBUG
65 
66 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
67 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
68 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
69 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
70 
71 static struct ctl_table_header *sunrpc_table_header;
72 
73 /*
74  * FIXME: changing the UDP slot table size should also resize the UDP
75  *        socket buffers for existing UDP transports
76  */
77 static ctl_table xs_tunables_table[] = {
78 	{
79 		.ctl_name	= CTL_SLOTTABLE_UDP,
80 		.procname	= "udp_slot_table_entries",
81 		.data		= &xprt_udp_slot_table_entries,
82 		.maxlen		= sizeof(unsigned int),
83 		.mode		= 0644,
84 		.proc_handler	= &proc_dointvec_minmax,
85 		.strategy	= &sysctl_intvec,
86 		.extra1		= &min_slot_table_size,
87 		.extra2		= &max_slot_table_size
88 	},
89 	{
90 		.ctl_name	= CTL_SLOTTABLE_TCP,
91 		.procname	= "tcp_slot_table_entries",
92 		.data		= &xprt_tcp_slot_table_entries,
93 		.maxlen		= sizeof(unsigned int),
94 		.mode		= 0644,
95 		.proc_handler	= &proc_dointvec_minmax,
96 		.strategy	= &sysctl_intvec,
97 		.extra1		= &min_slot_table_size,
98 		.extra2		= &max_slot_table_size
99 	},
100 	{
101 		.ctl_name	= CTL_MIN_RESVPORT,
102 		.procname	= "min_resvport",
103 		.data		= &xprt_min_resvport,
104 		.maxlen		= sizeof(unsigned int),
105 		.mode		= 0644,
106 		.proc_handler	= &proc_dointvec_minmax,
107 		.strategy	= &sysctl_intvec,
108 		.extra1		= &xprt_min_resvport_limit,
109 		.extra2		= &xprt_max_resvport_limit
110 	},
111 	{
112 		.ctl_name	= CTL_MAX_RESVPORT,
113 		.procname	= "max_resvport",
114 		.data		= &xprt_max_resvport,
115 		.maxlen		= sizeof(unsigned int),
116 		.mode		= 0644,
117 		.proc_handler	= &proc_dointvec_minmax,
118 		.strategy	= &sysctl_intvec,
119 		.extra1		= &xprt_min_resvport_limit,
120 		.extra2		= &xprt_max_resvport_limit
121 	},
122 	{
123 		.procname	= "tcp_fin_timeout",
124 		.data		= &xs_tcp_fin_timeout,
125 		.maxlen		= sizeof(xs_tcp_fin_timeout),
126 		.mode		= 0644,
127 		.proc_handler	= &proc_dointvec_jiffies,
128 		.strategy	= sysctl_jiffies
129 	},
130 	{
131 		.ctl_name = 0,
132 	},
133 };
134 
135 static ctl_table sunrpc_table[] = {
136 	{
137 		.ctl_name	= CTL_SUNRPC,
138 		.procname	= "sunrpc",
139 		.mode		= 0555,
140 		.child		= xs_tunables_table
141 	},
142 	{
143 		.ctl_name = 0,
144 	},
145 };
146 
147 #endif
148 
149 /*
150  * Time out for an RPC UDP socket connect.  UDP socket connects are
151  * synchronous, but we set a timeout anyway in case of resource
152  * exhaustion on the local host.
153  */
154 #define XS_UDP_CONN_TO		(5U * HZ)
155 
156 /*
157  * Wait duration for an RPC TCP connection to be established.  Solaris
158  * NFS over TCP uses 60 seconds, for example, which is in line with how
159  * long a server takes to reboot.
160  */
161 #define XS_TCP_CONN_TO		(60U * HZ)
162 
163 /*
164  * Wait duration for a reply from the RPC portmapper.
165  */
166 #define XS_BIND_TO		(60U * HZ)
167 
168 /*
169  * Delay if a UDP socket connect error occurs.  This is most likely some
170  * kind of resource problem on the local host.
171  */
172 #define XS_UDP_REEST_TO		(2U * HZ)
173 
174 /*
175  * The reestablish timeout allows clients to delay for a bit before attempting
176  * to reconnect to a server that just dropped our connection.
177  *
178  * We implement an exponential backoff when trying to reestablish a TCP
179  * transport connection with the server.  Some servers like to drop a TCP
180  * connection when they are overworked, so we start with a short timeout and
181  * increase over time if the server is down or not responding.
182  */
183 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
184 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
185 
186 /*
187  * TCP idle timeout; client drops the transport socket if it is idle
188  * for this long.  Note that we also timeout UDP sockets to prevent
189  * holding port numbers when there is no RPC traffic.
190  */
191 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
192 
193 #ifdef RPC_DEBUG
194 # undef  RPC_DEBUG_DATA
195 # define RPCDBG_FACILITY	RPCDBG_TRANS
196 #endif
197 
198 #ifdef RPC_DEBUG_DATA
199 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
200 {
201 	u8 *buf = (u8 *) packet;
202 	int j;
203 
204 	dprintk("RPC:       %s\n", msg);
205 	for (j = 0; j < count && j < 128; j += 4) {
206 		if (!(j & 31)) {
207 			if (j)
208 				dprintk("\n");
209 			dprintk("0x%04x ", j);
210 		}
211 		dprintk("%02x%02x%02x%02x ",
212 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
213 	}
214 	dprintk("\n");
215 }
216 #else
217 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
218 {
219 	/* NOP */
220 }
221 #endif
222 
223 struct sock_xprt {
224 	struct rpc_xprt		xprt;
225 
226 	/*
227 	 * Network layer
228 	 */
229 	struct socket *		sock;
230 	struct sock *		inet;
231 
232 	/*
233 	 * State of TCP reply receive
234 	 */
235 	__be32			tcp_fraghdr,
236 				tcp_xid;
237 
238 	u32			tcp_offset,
239 				tcp_reclen;
240 
241 	unsigned long		tcp_copied,
242 				tcp_flags;
243 
244 	/*
245 	 * Connection of transports
246 	 */
247 	struct delayed_work	connect_worker;
248 	struct sockaddr_storage	addr;
249 	unsigned short		port;
250 
251 	/*
252 	 * UDP socket buffer size parameters
253 	 */
254 	size_t			rcvsize,
255 				sndsize;
256 
257 	/*
258 	 * Saved socket callback addresses
259 	 */
260 	void			(*old_data_ready)(struct sock *, int);
261 	void			(*old_state_change)(struct sock *);
262 	void			(*old_write_space)(struct sock *);
263 	void			(*old_error_report)(struct sock *);
264 };
265 
266 /*
267  * TCP receive state flags
268  */
269 #define TCP_RCV_LAST_FRAG	(1UL << 0)
270 #define TCP_RCV_COPY_FRAGHDR	(1UL << 1)
271 #define TCP_RCV_COPY_XID	(1UL << 2)
272 #define TCP_RCV_COPY_DATA	(1UL << 3)
273 
274 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
275 {
276 	return (struct sockaddr *) &xprt->addr;
277 }
278 
279 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
280 {
281 	return (struct sockaddr_in *) &xprt->addr;
282 }
283 
284 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
285 {
286 	return (struct sockaddr_in6 *) &xprt->addr;
287 }
288 
289 static void xs_format_ipv4_peer_addresses(struct rpc_xprt *xprt,
290 					  const char *protocol,
291 					  const char *netid)
292 {
293 	struct sockaddr_in *addr = xs_addr_in(xprt);
294 	char *buf;
295 
296 	buf = kzalloc(20, GFP_KERNEL);
297 	if (buf) {
298 		snprintf(buf, 20, "%pI4", &addr->sin_addr.s_addr);
299 	}
300 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
301 
302 	buf = kzalloc(8, GFP_KERNEL);
303 	if (buf) {
304 		snprintf(buf, 8, "%u",
305 				ntohs(addr->sin_port));
306 	}
307 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
308 
309 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
310 
311 	buf = kzalloc(48, GFP_KERNEL);
312 	if (buf) {
313 		snprintf(buf, 48, "addr=%pI4 port=%u proto=%s",
314 			&addr->sin_addr.s_addr,
315 			ntohs(addr->sin_port),
316 			protocol);
317 	}
318 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
319 
320 	buf = kzalloc(10, GFP_KERNEL);
321 	if (buf) {
322 		snprintf(buf, 10, "%02x%02x%02x%02x",
323 				NIPQUAD(addr->sin_addr.s_addr));
324 	}
325 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
326 
327 	buf = kzalloc(8, GFP_KERNEL);
328 	if (buf) {
329 		snprintf(buf, 8, "%4hx",
330 				ntohs(addr->sin_port));
331 	}
332 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
333 
334 	buf = kzalloc(30, GFP_KERNEL);
335 	if (buf) {
336 		snprintf(buf, 30, "%pI4.%u.%u",
337 				&addr->sin_addr.s_addr,
338 				ntohs(addr->sin_port) >> 8,
339 				ntohs(addr->sin_port) & 0xff);
340 	}
341 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
342 
343 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
344 }
345 
346 static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt,
347 					  const char *protocol,
348 					  const char *netid)
349 {
350 	struct sockaddr_in6 *addr = xs_addr_in6(xprt);
351 	char *buf;
352 
353 	buf = kzalloc(40, GFP_KERNEL);
354 	if (buf) {
355 		snprintf(buf, 40, "%pI6",&addr->sin6_addr);
356 	}
357 	xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
358 
359 	buf = kzalloc(8, GFP_KERNEL);
360 	if (buf) {
361 		snprintf(buf, 8, "%u",
362 				ntohs(addr->sin6_port));
363 	}
364 	xprt->address_strings[RPC_DISPLAY_PORT] = buf;
365 
366 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
367 
368 	buf = kzalloc(64, GFP_KERNEL);
369 	if (buf) {
370 		snprintf(buf, 64, "addr=%pI6 port=%u proto=%s",
371 				&addr->sin6_addr,
372 				ntohs(addr->sin6_port),
373 				protocol);
374 	}
375 	xprt->address_strings[RPC_DISPLAY_ALL] = buf;
376 
377 	buf = kzalloc(36, GFP_KERNEL);
378 	if (buf)
379 		snprintf(buf, 36, "%pi6", &addr->sin6_addr);
380 
381 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
382 
383 	buf = kzalloc(8, GFP_KERNEL);
384 	if (buf) {
385 		snprintf(buf, 8, "%4hx",
386 				ntohs(addr->sin6_port));
387 	}
388 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
389 
390 	buf = kzalloc(50, GFP_KERNEL);
391 	if (buf) {
392 		snprintf(buf, 50, "%pI6.%u.%u",
393 			 &addr->sin6_addr,
394 			 ntohs(addr->sin6_port) >> 8,
395 			 ntohs(addr->sin6_port) & 0xff);
396 	}
397 	xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
398 
399 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
400 }
401 
402 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
403 {
404 	unsigned int i;
405 
406 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
407 		switch (i) {
408 		case RPC_DISPLAY_PROTO:
409 		case RPC_DISPLAY_NETID:
410 			continue;
411 		default:
412 			kfree(xprt->address_strings[i]);
413 		}
414 }
415 
416 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
417 
418 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
419 {
420 	struct msghdr msg = {
421 		.msg_name	= addr,
422 		.msg_namelen	= addrlen,
423 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
424 	};
425 	struct kvec iov = {
426 		.iov_base	= vec->iov_base + base,
427 		.iov_len	= vec->iov_len - base,
428 	};
429 
430 	if (iov.iov_len != 0)
431 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
432 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
433 }
434 
435 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
436 {
437 	struct page **ppage;
438 	unsigned int remainder;
439 	int err, sent = 0;
440 
441 	remainder = xdr->page_len - base;
442 	base += xdr->page_base;
443 	ppage = xdr->pages + (base >> PAGE_SHIFT);
444 	base &= ~PAGE_MASK;
445 	for(;;) {
446 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
447 		int flags = XS_SENDMSG_FLAGS;
448 
449 		remainder -= len;
450 		if (remainder != 0 || more)
451 			flags |= MSG_MORE;
452 		err = sock->ops->sendpage(sock, *ppage, base, len, flags);
453 		if (remainder == 0 || err != len)
454 			break;
455 		sent += err;
456 		ppage++;
457 		base = 0;
458 	}
459 	if (sent == 0)
460 		return err;
461 	if (err > 0)
462 		sent += err;
463 	return sent;
464 }
465 
466 /**
467  * xs_sendpages - write pages directly to a socket
468  * @sock: socket to send on
469  * @addr: UDP only -- address of destination
470  * @addrlen: UDP only -- length of destination address
471  * @xdr: buffer containing this request
472  * @base: starting position in the buffer
473  *
474  */
475 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
476 {
477 	unsigned int remainder = xdr->len - base;
478 	int err, sent = 0;
479 
480 	if (unlikely(!sock))
481 		return -ENOTSOCK;
482 
483 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
484 	if (base != 0) {
485 		addr = NULL;
486 		addrlen = 0;
487 	}
488 
489 	if (base < xdr->head[0].iov_len || addr != NULL) {
490 		unsigned int len = xdr->head[0].iov_len - base;
491 		remainder -= len;
492 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
493 		if (remainder == 0 || err != len)
494 			goto out;
495 		sent += err;
496 		base = 0;
497 	} else
498 		base -= xdr->head[0].iov_len;
499 
500 	if (base < xdr->page_len) {
501 		unsigned int len = xdr->page_len - base;
502 		remainder -= len;
503 		err = xs_send_pagedata(sock, xdr, base, remainder != 0);
504 		if (remainder == 0 || err != len)
505 			goto out;
506 		sent += err;
507 		base = 0;
508 	} else
509 		base -= xdr->page_len;
510 
511 	if (base >= xdr->tail[0].iov_len)
512 		return sent;
513 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
514 out:
515 	if (sent == 0)
516 		return err;
517 	if (err > 0)
518 		sent += err;
519 	return sent;
520 }
521 
522 static void xs_nospace_callback(struct rpc_task *task)
523 {
524 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
525 
526 	transport->inet->sk_write_pending--;
527 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
528 }
529 
530 /**
531  * xs_nospace - place task on wait queue if transmit was incomplete
532  * @task: task to put to sleep
533  *
534  */
535 static int xs_nospace(struct rpc_task *task)
536 {
537 	struct rpc_rqst *req = task->tk_rqstp;
538 	struct rpc_xprt *xprt = req->rq_xprt;
539 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
540 	int ret = 0;
541 
542 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
543 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
544 			req->rq_slen);
545 
546 	/* Protect against races with write_space */
547 	spin_lock_bh(&xprt->transport_lock);
548 
549 	/* Don't race with disconnect */
550 	if (xprt_connected(xprt)) {
551 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
552 			ret = -EAGAIN;
553 			/*
554 			 * Notify TCP that we're limited by the application
555 			 * window size
556 			 */
557 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
558 			transport->inet->sk_write_pending++;
559 			/* ...and wait for more buffer space */
560 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
561 		}
562 	} else {
563 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
564 		ret = -ENOTCONN;
565 	}
566 
567 	spin_unlock_bh(&xprt->transport_lock);
568 	return ret;
569 }
570 
571 /**
572  * xs_udp_send_request - write an RPC request to a UDP socket
573  * @task: address of RPC task that manages the state of an RPC request
574  *
575  * Return values:
576  *        0:	The request has been sent
577  *   EAGAIN:	The socket was blocked, please call again later to
578  *		complete the request
579  * ENOTCONN:	Caller needs to invoke connect logic then call again
580  *    other:	Some other error occured, the request was not sent
581  */
582 static int xs_udp_send_request(struct rpc_task *task)
583 {
584 	struct rpc_rqst *req = task->tk_rqstp;
585 	struct rpc_xprt *xprt = req->rq_xprt;
586 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
587 	struct xdr_buf *xdr = &req->rq_snd_buf;
588 	int status;
589 
590 	xs_pktdump("packet data:",
591 				req->rq_svec->iov_base,
592 				req->rq_svec->iov_len);
593 
594 	if (!xprt_bound(xprt))
595 		return -ENOTCONN;
596 	status = xs_sendpages(transport->sock,
597 			      xs_addr(xprt),
598 			      xprt->addrlen, xdr,
599 			      req->rq_bytes_sent);
600 
601 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
602 			xdr->len - req->rq_bytes_sent, status);
603 
604 	if (status >= 0) {
605 		task->tk_bytes_sent += status;
606 		if (status >= req->rq_slen)
607 			return 0;
608 		/* Still some bytes left; set up for a retry later. */
609 		status = -EAGAIN;
610 	}
611 	if (!transport->sock)
612 		goto out;
613 
614 	switch (status) {
615 	case -ENOTSOCK:
616 		status = -ENOTCONN;
617 		/* Should we call xs_close() here? */
618 		break;
619 	case -EAGAIN:
620 		status = xs_nospace(task);
621 		break;
622 	default:
623 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
624 			-status);
625 	case -ENETUNREACH:
626 	case -EPIPE:
627 	case -ECONNREFUSED:
628 		/* When the server has died, an ICMP port unreachable message
629 		 * prompts ECONNREFUSED. */
630 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
631 	}
632 out:
633 	return status;
634 }
635 
636 /**
637  * xs_tcp_shutdown - gracefully shut down a TCP socket
638  * @xprt: transport
639  *
640  * Initiates a graceful shutdown of the TCP socket by calling the
641  * equivalent of shutdown(SHUT_WR);
642  */
643 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
644 {
645 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
646 	struct socket *sock = transport->sock;
647 
648 	if (sock != NULL)
649 		kernel_sock_shutdown(sock, SHUT_WR);
650 }
651 
652 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
653 {
654 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
655 	rpc_fraghdr *base = buf->head[0].iov_base;
656 	*base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
657 }
658 
659 /**
660  * xs_tcp_send_request - write an RPC request to a TCP socket
661  * @task: address of RPC task that manages the state of an RPC request
662  *
663  * Return values:
664  *        0:	The request has been sent
665  *   EAGAIN:	The socket was blocked, please call again later to
666  *		complete the request
667  * ENOTCONN:	Caller needs to invoke connect logic then call again
668  *    other:	Some other error occured, the request was not sent
669  *
670  * XXX: In the case of soft timeouts, should we eventually give up
671  *	if sendmsg is not able to make progress?
672  */
673 static int xs_tcp_send_request(struct rpc_task *task)
674 {
675 	struct rpc_rqst *req = task->tk_rqstp;
676 	struct rpc_xprt *xprt = req->rq_xprt;
677 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
678 	struct xdr_buf *xdr = &req->rq_snd_buf;
679 	int status;
680 
681 	xs_encode_tcp_record_marker(&req->rq_snd_buf);
682 
683 	xs_pktdump("packet data:",
684 				req->rq_svec->iov_base,
685 				req->rq_svec->iov_len);
686 
687 	/* Continue transmitting the packet/record. We must be careful
688 	 * to cope with writespace callbacks arriving _after_ we have
689 	 * called sendmsg(). */
690 	while (1) {
691 		status = xs_sendpages(transport->sock,
692 					NULL, 0, xdr, req->rq_bytes_sent);
693 
694 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
695 				xdr->len - req->rq_bytes_sent, status);
696 
697 		if (unlikely(status < 0))
698 			break;
699 
700 		/* If we've sent the entire packet, immediately
701 		 * reset the count of bytes sent. */
702 		req->rq_bytes_sent += status;
703 		task->tk_bytes_sent += status;
704 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
705 			req->rq_bytes_sent = 0;
706 			return 0;
707 		}
708 
709 		if (status != 0)
710 			continue;
711 		status = -EAGAIN;
712 		break;
713 	}
714 	if (!transport->sock)
715 		goto out;
716 
717 	switch (status) {
718 	case -ENOTSOCK:
719 		status = -ENOTCONN;
720 		/* Should we call xs_close() here? */
721 		break;
722 	case -EAGAIN:
723 		status = xs_nospace(task);
724 		break;
725 	default:
726 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
727 			-status);
728 	case -ECONNRESET:
729 	case -EPIPE:
730 		xs_tcp_shutdown(xprt);
731 	case -ECONNREFUSED:
732 	case -ENOTCONN:
733 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
734 	}
735 out:
736 	return status;
737 }
738 
739 /**
740  * xs_tcp_release_xprt - clean up after a tcp transmission
741  * @xprt: transport
742  * @task: rpc task
743  *
744  * This cleans up if an error causes us to abort the transmission of a request.
745  * In this case, the socket may need to be reset in order to avoid confusing
746  * the server.
747  */
748 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
749 {
750 	struct rpc_rqst *req;
751 
752 	if (task != xprt->snd_task)
753 		return;
754 	if (task == NULL)
755 		goto out_release;
756 	req = task->tk_rqstp;
757 	if (req->rq_bytes_sent == 0)
758 		goto out_release;
759 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
760 		goto out_release;
761 	set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
762 out_release:
763 	xprt_release_xprt(xprt, task);
764 }
765 
766 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
767 {
768 	transport->old_data_ready = sk->sk_data_ready;
769 	transport->old_state_change = sk->sk_state_change;
770 	transport->old_write_space = sk->sk_write_space;
771 	transport->old_error_report = sk->sk_error_report;
772 }
773 
774 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
775 {
776 	sk->sk_data_ready = transport->old_data_ready;
777 	sk->sk_state_change = transport->old_state_change;
778 	sk->sk_write_space = transport->old_write_space;
779 	sk->sk_error_report = transport->old_error_report;
780 }
781 
782 static void xs_reset_transport(struct sock_xprt *transport)
783 {
784 	struct socket *sock = transport->sock;
785 	struct sock *sk = transport->inet;
786 
787 	if (sk == NULL)
788 		return;
789 
790 	write_lock_bh(&sk->sk_callback_lock);
791 	transport->inet = NULL;
792 	transport->sock = NULL;
793 
794 	sk->sk_user_data = NULL;
795 
796 	xs_restore_old_callbacks(transport, sk);
797 	write_unlock_bh(&sk->sk_callback_lock);
798 
799 	sk->sk_no_check = 0;
800 
801 	sock_release(sock);
802 }
803 
804 /**
805  * xs_close - close a socket
806  * @xprt: transport
807  *
808  * This is used when all requests are complete; ie, no DRC state remains
809  * on the server we want to save.
810  */
811 static void xs_close(struct rpc_xprt *xprt)
812 {
813 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
814 
815 	dprintk("RPC:       xs_close xprt %p\n", xprt);
816 
817 	xs_reset_transport(transport);
818 
819 	smp_mb__before_clear_bit();
820 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
821 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
822 	clear_bit(XPRT_CLOSING, &xprt->state);
823 	smp_mb__after_clear_bit();
824 	xprt_disconnect_done(xprt);
825 }
826 
827 /**
828  * xs_destroy - prepare to shutdown a transport
829  * @xprt: doomed transport
830  *
831  */
832 static void xs_destroy(struct rpc_xprt *xprt)
833 {
834 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
835 
836 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
837 
838 	cancel_rearming_delayed_work(&transport->connect_worker);
839 
840 	xs_close(xprt);
841 	xs_free_peer_addresses(xprt);
842 	kfree(xprt->slot);
843 	kfree(xprt);
844 	module_put(THIS_MODULE);
845 }
846 
847 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
848 {
849 	return (struct rpc_xprt *) sk->sk_user_data;
850 }
851 
852 /**
853  * xs_udp_data_ready - "data ready" callback for UDP sockets
854  * @sk: socket with data to read
855  * @len: how much data to read
856  *
857  */
858 static void xs_udp_data_ready(struct sock *sk, int len)
859 {
860 	struct rpc_task *task;
861 	struct rpc_xprt *xprt;
862 	struct rpc_rqst *rovr;
863 	struct sk_buff *skb;
864 	int err, repsize, copied;
865 	u32 _xid;
866 	__be32 *xp;
867 
868 	read_lock(&sk->sk_callback_lock);
869 	dprintk("RPC:       xs_udp_data_ready...\n");
870 	if (!(xprt = xprt_from_sock(sk)))
871 		goto out;
872 
873 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
874 		goto out;
875 
876 	if (xprt->shutdown)
877 		goto dropit;
878 
879 	repsize = skb->len - sizeof(struct udphdr);
880 	if (repsize < 4) {
881 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
882 		goto dropit;
883 	}
884 
885 	/* Copy the XID from the skb... */
886 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
887 				sizeof(_xid), &_xid);
888 	if (xp == NULL)
889 		goto dropit;
890 
891 	/* Look up and lock the request corresponding to the given XID */
892 	spin_lock(&xprt->transport_lock);
893 	rovr = xprt_lookup_rqst(xprt, *xp);
894 	if (!rovr)
895 		goto out_unlock;
896 	task = rovr->rq_task;
897 
898 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
899 		copied = repsize;
900 
901 	/* Suck it into the iovec, verify checksum if not done by hw. */
902 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
903 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
904 		goto out_unlock;
905 	}
906 
907 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
908 
909 	/* Something worked... */
910 	dst_confirm(skb->dst);
911 
912 	xprt_adjust_cwnd(task, copied);
913 	xprt_update_rtt(task);
914 	xprt_complete_rqst(task, copied);
915 
916  out_unlock:
917 	spin_unlock(&xprt->transport_lock);
918  dropit:
919 	skb_free_datagram(sk, skb);
920  out:
921 	read_unlock(&sk->sk_callback_lock);
922 }
923 
924 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
925 {
926 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
927 	size_t len, used;
928 	char *p;
929 
930 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
931 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
932 	used = xdr_skb_read_bits(desc, p, len);
933 	transport->tcp_offset += used;
934 	if (used != len)
935 		return;
936 
937 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
938 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
939 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
940 	else
941 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
942 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
943 
944 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
945 	transport->tcp_offset = 0;
946 
947 	/* Sanity check of the record length */
948 	if (unlikely(transport->tcp_reclen < 4)) {
949 		dprintk("RPC:       invalid TCP record fragment length\n");
950 		xprt_force_disconnect(xprt);
951 		return;
952 	}
953 	dprintk("RPC:       reading TCP record fragment of length %d\n",
954 			transport->tcp_reclen);
955 }
956 
957 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
958 {
959 	if (transport->tcp_offset == transport->tcp_reclen) {
960 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
961 		transport->tcp_offset = 0;
962 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
963 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
964 			transport->tcp_flags |= TCP_RCV_COPY_XID;
965 			transport->tcp_copied = 0;
966 		}
967 	}
968 }
969 
970 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
971 {
972 	size_t len, used;
973 	char *p;
974 
975 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
976 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
977 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
978 	used = xdr_skb_read_bits(desc, p, len);
979 	transport->tcp_offset += used;
980 	if (used != len)
981 		return;
982 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
983 	transport->tcp_flags |= TCP_RCV_COPY_DATA;
984 	transport->tcp_copied = 4;
985 	dprintk("RPC:       reading reply for XID %08x\n",
986 			ntohl(transport->tcp_xid));
987 	xs_tcp_check_fraghdr(transport);
988 }
989 
990 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
991 {
992 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
993 	struct rpc_rqst *req;
994 	struct xdr_buf *rcvbuf;
995 	size_t len;
996 	ssize_t r;
997 
998 	/* Find and lock the request corresponding to this xid */
999 	spin_lock(&xprt->transport_lock);
1000 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1001 	if (!req) {
1002 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1003 		dprintk("RPC:       XID %08x request not found!\n",
1004 				ntohl(transport->tcp_xid));
1005 		spin_unlock(&xprt->transport_lock);
1006 		return;
1007 	}
1008 
1009 	rcvbuf = &req->rq_private_buf;
1010 	len = desc->count;
1011 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1012 		struct xdr_skb_reader my_desc;
1013 
1014 		len = transport->tcp_reclen - transport->tcp_offset;
1015 		memcpy(&my_desc, desc, sizeof(my_desc));
1016 		my_desc.count = len;
1017 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1018 					  &my_desc, xdr_skb_read_bits);
1019 		desc->count -= r;
1020 		desc->offset += r;
1021 	} else
1022 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1023 					  desc, xdr_skb_read_bits);
1024 
1025 	if (r > 0) {
1026 		transport->tcp_copied += r;
1027 		transport->tcp_offset += r;
1028 	}
1029 	if (r != len) {
1030 		/* Error when copying to the receive buffer,
1031 		 * usually because we weren't able to allocate
1032 		 * additional buffer pages. All we can do now
1033 		 * is turn off TCP_RCV_COPY_DATA, so the request
1034 		 * will not receive any additional updates,
1035 		 * and time out.
1036 		 * Any remaining data from this record will
1037 		 * be discarded.
1038 		 */
1039 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1040 		dprintk("RPC:       XID %08x truncated request\n",
1041 				ntohl(transport->tcp_xid));
1042 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1043 				"tcp_offset = %u, tcp_reclen = %u\n",
1044 				xprt, transport->tcp_copied,
1045 				transport->tcp_offset, transport->tcp_reclen);
1046 		goto out;
1047 	}
1048 
1049 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1050 			ntohl(transport->tcp_xid), r);
1051 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1052 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1053 			transport->tcp_offset, transport->tcp_reclen);
1054 
1055 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1056 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1057 	else if (transport->tcp_offset == transport->tcp_reclen) {
1058 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1059 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1060 	}
1061 
1062 out:
1063 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1064 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1065 	spin_unlock(&xprt->transport_lock);
1066 	xs_tcp_check_fraghdr(transport);
1067 }
1068 
1069 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1070 {
1071 	size_t len;
1072 
1073 	len = transport->tcp_reclen - transport->tcp_offset;
1074 	if (len > desc->count)
1075 		len = desc->count;
1076 	desc->count -= len;
1077 	desc->offset += len;
1078 	transport->tcp_offset += len;
1079 	dprintk("RPC:       discarded %Zu bytes\n", len);
1080 	xs_tcp_check_fraghdr(transport);
1081 }
1082 
1083 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1084 {
1085 	struct rpc_xprt *xprt = rd_desc->arg.data;
1086 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1087 	struct xdr_skb_reader desc = {
1088 		.skb	= skb,
1089 		.offset	= offset,
1090 		.count	= len,
1091 	};
1092 
1093 	dprintk("RPC:       xs_tcp_data_recv started\n");
1094 	do {
1095 		/* Read in a new fragment marker if necessary */
1096 		/* Can we ever really expect to get completely empty fragments? */
1097 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1098 			xs_tcp_read_fraghdr(xprt, &desc);
1099 			continue;
1100 		}
1101 		/* Read in the xid if necessary */
1102 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1103 			xs_tcp_read_xid(transport, &desc);
1104 			continue;
1105 		}
1106 		/* Read in the request data */
1107 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1108 			xs_tcp_read_request(xprt, &desc);
1109 			continue;
1110 		}
1111 		/* Skip over any trailing bytes on short reads */
1112 		xs_tcp_read_discard(transport, &desc);
1113 	} while (desc.count);
1114 	dprintk("RPC:       xs_tcp_data_recv done\n");
1115 	return len - desc.count;
1116 }
1117 
1118 /**
1119  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1120  * @sk: socket with data to read
1121  * @bytes: how much data to read
1122  *
1123  */
1124 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1125 {
1126 	struct rpc_xprt *xprt;
1127 	read_descriptor_t rd_desc;
1128 	int read;
1129 
1130 	dprintk("RPC:       xs_tcp_data_ready...\n");
1131 
1132 	read_lock(&sk->sk_callback_lock);
1133 	if (!(xprt = xprt_from_sock(sk)))
1134 		goto out;
1135 	if (xprt->shutdown)
1136 		goto out;
1137 
1138 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1139 	rd_desc.arg.data = xprt;
1140 	do {
1141 		rd_desc.count = 65536;
1142 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1143 	} while (read > 0);
1144 out:
1145 	read_unlock(&sk->sk_callback_lock);
1146 }
1147 
1148 /*
1149  * Do the equivalent of linger/linger2 handling for dealing with
1150  * broken servers that don't close the socket in a timely
1151  * fashion
1152  */
1153 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1154 		unsigned long timeout)
1155 {
1156 	struct sock_xprt *transport;
1157 
1158 	if (xprt_test_and_set_connecting(xprt))
1159 		return;
1160 	set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1161 	transport = container_of(xprt, struct sock_xprt, xprt);
1162 	queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1163 			   timeout);
1164 }
1165 
1166 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1167 {
1168 	struct sock_xprt *transport;
1169 
1170 	transport = container_of(xprt, struct sock_xprt, xprt);
1171 
1172 	if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1173 	    !cancel_delayed_work(&transport->connect_worker))
1174 		return;
1175 	clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1176 	xprt_clear_connecting(xprt);
1177 }
1178 
1179 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1180 {
1181 	smp_mb__before_clear_bit();
1182 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1183 	clear_bit(XPRT_CLOSING, &xprt->state);
1184 	smp_mb__after_clear_bit();
1185 	/* Mark transport as closed and wake up all pending tasks */
1186 	xprt_disconnect_done(xprt);
1187 }
1188 
1189 /**
1190  * xs_tcp_state_change - callback to handle TCP socket state changes
1191  * @sk: socket whose state has changed
1192  *
1193  */
1194 static void xs_tcp_state_change(struct sock *sk)
1195 {
1196 	struct rpc_xprt *xprt;
1197 
1198 	read_lock(&sk->sk_callback_lock);
1199 	if (!(xprt = xprt_from_sock(sk)))
1200 		goto out;
1201 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1202 	dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1203 			sk->sk_state, xprt_connected(xprt),
1204 			sock_flag(sk, SOCK_DEAD),
1205 			sock_flag(sk, SOCK_ZAPPED));
1206 
1207 	switch (sk->sk_state) {
1208 	case TCP_ESTABLISHED:
1209 		spin_lock_bh(&xprt->transport_lock);
1210 		if (!xprt_test_and_set_connected(xprt)) {
1211 			struct sock_xprt *transport = container_of(xprt,
1212 					struct sock_xprt, xprt);
1213 
1214 			/* Reset TCP record info */
1215 			transport->tcp_offset = 0;
1216 			transport->tcp_reclen = 0;
1217 			transport->tcp_copied = 0;
1218 			transport->tcp_flags =
1219 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1220 
1221 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1222 		}
1223 		spin_unlock_bh(&xprt->transport_lock);
1224 		break;
1225 	case TCP_FIN_WAIT1:
1226 		/* The client initiated a shutdown of the socket */
1227 		xprt->connect_cookie++;
1228 		xprt->reestablish_timeout = 0;
1229 		set_bit(XPRT_CLOSING, &xprt->state);
1230 		smp_mb__before_clear_bit();
1231 		clear_bit(XPRT_CONNECTED, &xprt->state);
1232 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1233 		smp_mb__after_clear_bit();
1234 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1235 		break;
1236 	case TCP_CLOSE_WAIT:
1237 		/* The server initiated a shutdown of the socket */
1238 		xprt_force_disconnect(xprt);
1239 	case TCP_SYN_SENT:
1240 		xprt->connect_cookie++;
1241 	case TCP_CLOSING:
1242 		/*
1243 		 * If the server closed down the connection, make sure that
1244 		 * we back off before reconnecting
1245 		 */
1246 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1247 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1248 		break;
1249 	case TCP_LAST_ACK:
1250 		set_bit(XPRT_CLOSING, &xprt->state);
1251 		xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1252 		smp_mb__before_clear_bit();
1253 		clear_bit(XPRT_CONNECTED, &xprt->state);
1254 		smp_mb__after_clear_bit();
1255 		break;
1256 	case TCP_CLOSE:
1257 		xs_tcp_cancel_linger_timeout(xprt);
1258 		xs_sock_mark_closed(xprt);
1259 	}
1260  out:
1261 	read_unlock(&sk->sk_callback_lock);
1262 }
1263 
1264 /**
1265  * xs_error_report - callback mainly for catching socket errors
1266  * @sk: socket
1267  */
1268 static void xs_error_report(struct sock *sk)
1269 {
1270 	struct rpc_xprt *xprt;
1271 
1272 	read_lock(&sk->sk_callback_lock);
1273 	if (!(xprt = xprt_from_sock(sk)))
1274 		goto out;
1275 	dprintk("RPC:       %s client %p...\n"
1276 			"RPC:       error %d\n",
1277 			__func__, xprt, sk->sk_err);
1278 	xprt_wake_pending_tasks(xprt, -EAGAIN);
1279 out:
1280 	read_unlock(&sk->sk_callback_lock);
1281 }
1282 
1283 static void xs_write_space(struct sock *sk)
1284 {
1285 	struct socket *sock;
1286 	struct rpc_xprt *xprt;
1287 
1288 	if (unlikely(!(sock = sk->sk_socket)))
1289 		return;
1290 	clear_bit(SOCK_NOSPACE, &sock->flags);
1291 
1292 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1293 		return;
1294 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1295 		return;
1296 
1297 	xprt_write_space(xprt);
1298 }
1299 
1300 /**
1301  * xs_udp_write_space - callback invoked when socket buffer space
1302  *                             becomes available
1303  * @sk: socket whose state has changed
1304  *
1305  * Called when more output buffer space is available for this socket.
1306  * We try not to wake our writers until they can make "significant"
1307  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1308  * with a bunch of small requests.
1309  */
1310 static void xs_udp_write_space(struct sock *sk)
1311 {
1312 	read_lock(&sk->sk_callback_lock);
1313 
1314 	/* from net/core/sock.c:sock_def_write_space */
1315 	if (sock_writeable(sk))
1316 		xs_write_space(sk);
1317 
1318 	read_unlock(&sk->sk_callback_lock);
1319 }
1320 
1321 /**
1322  * xs_tcp_write_space - callback invoked when socket buffer space
1323  *                             becomes available
1324  * @sk: socket whose state has changed
1325  *
1326  * Called when more output buffer space is available for this socket.
1327  * We try not to wake our writers until they can make "significant"
1328  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1329  * with a bunch of small requests.
1330  */
1331 static void xs_tcp_write_space(struct sock *sk)
1332 {
1333 	read_lock(&sk->sk_callback_lock);
1334 
1335 	/* from net/core/stream.c:sk_stream_write_space */
1336 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
1337 		xs_write_space(sk);
1338 
1339 	read_unlock(&sk->sk_callback_lock);
1340 }
1341 
1342 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1343 {
1344 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1345 	struct sock *sk = transport->inet;
1346 
1347 	if (transport->rcvsize) {
1348 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1349 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1350 	}
1351 	if (transport->sndsize) {
1352 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1353 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1354 		sk->sk_write_space(sk);
1355 	}
1356 }
1357 
1358 /**
1359  * xs_udp_set_buffer_size - set send and receive limits
1360  * @xprt: generic transport
1361  * @sndsize: requested size of send buffer, in bytes
1362  * @rcvsize: requested size of receive buffer, in bytes
1363  *
1364  * Set socket send and receive buffer size limits.
1365  */
1366 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1367 {
1368 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1369 
1370 	transport->sndsize = 0;
1371 	if (sndsize)
1372 		transport->sndsize = sndsize + 1024;
1373 	transport->rcvsize = 0;
1374 	if (rcvsize)
1375 		transport->rcvsize = rcvsize + 1024;
1376 
1377 	xs_udp_do_set_buffer_size(xprt);
1378 }
1379 
1380 /**
1381  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1382  * @task: task that timed out
1383  *
1384  * Adjust the congestion window after a retransmit timeout has occurred.
1385  */
1386 static void xs_udp_timer(struct rpc_task *task)
1387 {
1388 	xprt_adjust_cwnd(task, -ETIMEDOUT);
1389 }
1390 
1391 static unsigned short xs_get_random_port(void)
1392 {
1393 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1394 	unsigned short rand = (unsigned short) net_random() % range;
1395 	return rand + xprt_min_resvport;
1396 }
1397 
1398 /**
1399  * xs_set_port - reset the port number in the remote endpoint address
1400  * @xprt: generic transport
1401  * @port: new port number
1402  *
1403  */
1404 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1405 {
1406 	struct sockaddr *addr = xs_addr(xprt);
1407 
1408 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1409 
1410 	switch (addr->sa_family) {
1411 	case AF_INET:
1412 		((struct sockaddr_in *)addr)->sin_port = htons(port);
1413 		break;
1414 	case AF_INET6:
1415 		((struct sockaddr_in6 *)addr)->sin6_port = htons(port);
1416 		break;
1417 	default:
1418 		BUG();
1419 	}
1420 }
1421 
1422 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1423 {
1424 	unsigned short port = transport->port;
1425 
1426 	if (port == 0 && transport->xprt.resvport)
1427 		port = xs_get_random_port();
1428 	return port;
1429 }
1430 
1431 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1432 {
1433 	if (transport->port != 0)
1434 		transport->port = 0;
1435 	if (!transport->xprt.resvport)
1436 		return 0;
1437 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1438 		return xprt_max_resvport;
1439 	return --port;
1440 }
1441 
1442 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1443 {
1444 	struct sockaddr_in myaddr = {
1445 		.sin_family = AF_INET,
1446 	};
1447 	struct sockaddr_in *sa;
1448 	int err, nloop = 0;
1449 	unsigned short port = xs_get_srcport(transport, sock);
1450 	unsigned short last;
1451 
1452 	sa = (struct sockaddr_in *)&transport->addr;
1453 	myaddr.sin_addr = sa->sin_addr;
1454 	do {
1455 		myaddr.sin_port = htons(port);
1456 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1457 						sizeof(myaddr));
1458 		if (port == 0)
1459 			break;
1460 		if (err == 0) {
1461 			transport->port = port;
1462 			break;
1463 		}
1464 		last = port;
1465 		port = xs_next_srcport(transport, sock, port);
1466 		if (port > last)
1467 			nloop++;
1468 	} while (err == -EADDRINUSE && nloop != 2);
1469 	dprintk("RPC:       %s %pI4:%u: %s (%d)\n",
1470 			__func__, &myaddr.sin_addr,
1471 			port, err ? "failed" : "ok", err);
1472 	return err;
1473 }
1474 
1475 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1476 {
1477 	struct sockaddr_in6 myaddr = {
1478 		.sin6_family = AF_INET6,
1479 	};
1480 	struct sockaddr_in6 *sa;
1481 	int err, nloop = 0;
1482 	unsigned short port = xs_get_srcport(transport, sock);
1483 	unsigned short last;
1484 
1485 	sa = (struct sockaddr_in6 *)&transport->addr;
1486 	myaddr.sin6_addr = sa->sin6_addr;
1487 	do {
1488 		myaddr.sin6_port = htons(port);
1489 		err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1490 						sizeof(myaddr));
1491 		if (port == 0)
1492 			break;
1493 		if (err == 0) {
1494 			transport->port = port;
1495 			break;
1496 		}
1497 		last = port;
1498 		port = xs_next_srcport(transport, sock, port);
1499 		if (port > last)
1500 			nloop++;
1501 	} while (err == -EADDRINUSE && nloop != 2);
1502 	dprintk("RPC:       xs_bind6 %pI6:%u: %s (%d)\n",
1503 		&myaddr.sin6_addr, port, err ? "failed" : "ok", err);
1504 	return err;
1505 }
1506 
1507 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1508 static struct lock_class_key xs_key[2];
1509 static struct lock_class_key xs_slock_key[2];
1510 
1511 static inline void xs_reclassify_socket4(struct socket *sock)
1512 {
1513 	struct sock *sk = sock->sk;
1514 
1515 	BUG_ON(sock_owned_by_user(sk));
1516 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1517 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1518 }
1519 
1520 static inline void xs_reclassify_socket6(struct socket *sock)
1521 {
1522 	struct sock *sk = sock->sk;
1523 
1524 	BUG_ON(sock_owned_by_user(sk));
1525 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1526 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1527 }
1528 #else
1529 static inline void xs_reclassify_socket4(struct socket *sock)
1530 {
1531 }
1532 
1533 static inline void xs_reclassify_socket6(struct socket *sock)
1534 {
1535 }
1536 #endif
1537 
1538 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1539 {
1540 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1541 
1542 	if (!transport->inet) {
1543 		struct sock *sk = sock->sk;
1544 
1545 		write_lock_bh(&sk->sk_callback_lock);
1546 
1547 		xs_save_old_callbacks(transport, sk);
1548 
1549 		sk->sk_user_data = xprt;
1550 		sk->sk_data_ready = xs_udp_data_ready;
1551 		sk->sk_write_space = xs_udp_write_space;
1552 		sk->sk_error_report = xs_error_report;
1553 		sk->sk_no_check = UDP_CSUM_NORCV;
1554 		sk->sk_allocation = GFP_ATOMIC;
1555 
1556 		xprt_set_connected(xprt);
1557 
1558 		/* Reset to new socket */
1559 		transport->sock = sock;
1560 		transport->inet = sk;
1561 
1562 		write_unlock_bh(&sk->sk_callback_lock);
1563 	}
1564 	xs_udp_do_set_buffer_size(xprt);
1565 }
1566 
1567 /**
1568  * xs_udp_connect_worker4 - set up a UDP socket
1569  * @work: RPC transport to connect
1570  *
1571  * Invoked by a work queue tasklet.
1572  */
1573 static void xs_udp_connect_worker4(struct work_struct *work)
1574 {
1575 	struct sock_xprt *transport =
1576 		container_of(work, struct sock_xprt, connect_worker.work);
1577 	struct rpc_xprt *xprt = &transport->xprt;
1578 	struct socket *sock = transport->sock;
1579 	int err, status = -EIO;
1580 
1581 	if (xprt->shutdown)
1582 		goto out;
1583 
1584 	/* Start by resetting any existing state */
1585 	xs_reset_transport(transport);
1586 
1587 	err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
1588 	if (err < 0) {
1589 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1590 		goto out;
1591 	}
1592 	xs_reclassify_socket4(sock);
1593 
1594 	if (xs_bind4(transport, sock)) {
1595 		sock_release(sock);
1596 		goto out;
1597 	}
1598 
1599 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1600 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1601 
1602 	xs_udp_finish_connecting(xprt, sock);
1603 	status = 0;
1604 out:
1605 	xprt_clear_connecting(xprt);
1606 	xprt_wake_pending_tasks(xprt, status);
1607 }
1608 
1609 /**
1610  * xs_udp_connect_worker6 - set up a UDP socket
1611  * @work: RPC transport to connect
1612  *
1613  * Invoked by a work queue tasklet.
1614  */
1615 static void xs_udp_connect_worker6(struct work_struct *work)
1616 {
1617 	struct sock_xprt *transport =
1618 		container_of(work, struct sock_xprt, connect_worker.work);
1619 	struct rpc_xprt *xprt = &transport->xprt;
1620 	struct socket *sock = transport->sock;
1621 	int err, status = -EIO;
1622 
1623 	if (xprt->shutdown)
1624 		goto out;
1625 
1626 	/* Start by resetting any existing state */
1627 	xs_reset_transport(transport);
1628 
1629 	err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock);
1630 	if (err < 0) {
1631 		dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1632 		goto out;
1633 	}
1634 	xs_reclassify_socket6(sock);
1635 
1636 	if (xs_bind6(transport, sock) < 0) {
1637 		sock_release(sock);
1638 		goto out;
1639 	}
1640 
1641 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1642 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1643 
1644 	xs_udp_finish_connecting(xprt, sock);
1645 	status = 0;
1646 out:
1647 	xprt_clear_connecting(xprt);
1648 	xprt_wake_pending_tasks(xprt, status);
1649 }
1650 
1651 /*
1652  * We need to preserve the port number so the reply cache on the server can
1653  * find our cached RPC replies when we get around to reconnecting.
1654  */
1655 static void xs_abort_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
1656 {
1657 	int result;
1658 	struct sockaddr any;
1659 
1660 	dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1661 
1662 	/*
1663 	 * Disconnect the transport socket by doing a connect operation
1664 	 * with AF_UNSPEC.  This should return immediately...
1665 	 */
1666 	memset(&any, 0, sizeof(any));
1667 	any.sa_family = AF_UNSPEC;
1668 	result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1669 	if (!result)
1670 		xs_sock_mark_closed(xprt);
1671 	else
1672 		dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1673 				result);
1674 }
1675 
1676 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
1677 {
1678 	unsigned int state = transport->inet->sk_state;
1679 
1680 	if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED)
1681 		return;
1682 	if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT))
1683 		return;
1684 	xs_abort_connection(xprt, transport);
1685 }
1686 
1687 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1688 {
1689 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1690 
1691 	if (!transport->inet) {
1692 		struct sock *sk = sock->sk;
1693 
1694 		write_lock_bh(&sk->sk_callback_lock);
1695 
1696 		xs_save_old_callbacks(transport, sk);
1697 
1698 		sk->sk_user_data = xprt;
1699 		sk->sk_data_ready = xs_tcp_data_ready;
1700 		sk->sk_state_change = xs_tcp_state_change;
1701 		sk->sk_write_space = xs_tcp_write_space;
1702 		sk->sk_error_report = xs_error_report;
1703 		sk->sk_allocation = GFP_ATOMIC;
1704 
1705 		/* socket options */
1706 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1707 		sock_reset_flag(sk, SOCK_LINGER);
1708 		tcp_sk(sk)->linger2 = 0;
1709 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1710 
1711 		xprt_clear_connected(xprt);
1712 
1713 		/* Reset to new socket */
1714 		transport->sock = sock;
1715 		transport->inet = sk;
1716 
1717 		write_unlock_bh(&sk->sk_callback_lock);
1718 	}
1719 
1720 	if (!xprt_bound(xprt))
1721 		return -ENOTCONN;
1722 
1723 	/* Tell the socket layer to start connecting... */
1724 	xprt->stat.connect_count++;
1725 	xprt->stat.connect_start = jiffies;
1726 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1727 }
1728 
1729 /**
1730  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
1731  * @xprt: RPC transport to connect
1732  * @transport: socket transport to connect
1733  * @create_sock: function to create a socket of the correct type
1734  *
1735  * Invoked by a work queue tasklet.
1736  */
1737 static void xs_tcp_setup_socket(struct rpc_xprt *xprt,
1738 		struct sock_xprt *transport,
1739 		struct socket *(*create_sock)(struct rpc_xprt *,
1740 			struct sock_xprt *))
1741 {
1742 	struct socket *sock = transport->sock;
1743 	int status = -EIO;
1744 
1745 	if (xprt->shutdown)
1746 		goto out;
1747 
1748 	if (!sock) {
1749 		clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1750 		sock = create_sock(xprt, transport);
1751 		if (IS_ERR(sock)) {
1752 			status = PTR_ERR(sock);
1753 			goto out;
1754 		}
1755 	} else {
1756 		int abort_and_exit;
1757 
1758 		abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
1759 				&xprt->state);
1760 		/* "close" the socket, preserving the local port */
1761 		xs_tcp_reuse_connection(xprt, transport);
1762 
1763 		if (abort_and_exit)
1764 			goto out_eagain;
1765 	}
1766 
1767 	dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1768 			xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1769 
1770 	status = xs_tcp_finish_connecting(xprt, sock);
1771 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1772 			xprt, -status, xprt_connected(xprt),
1773 			sock->sk->sk_state);
1774 	switch (status) {
1775 	case -ECONNREFUSED:
1776 	case -ECONNRESET:
1777 	case -ENETUNREACH:
1778 		/* retry with existing socket, after a delay */
1779 	case 0:
1780 	case -EINPROGRESS:
1781 	case -EALREADY:
1782 		xprt_clear_connecting(xprt);
1783 		return;
1784 	}
1785 	/* get rid of existing socket, and retry */
1786 	xs_tcp_shutdown(xprt);
1787 	printk("%s: connect returned unhandled error %d\n",
1788 			__func__, status);
1789 out_eagain:
1790 	status = -EAGAIN;
1791 out:
1792 	xprt_clear_connecting(xprt);
1793 	xprt_wake_pending_tasks(xprt, status);
1794 }
1795 
1796 static struct socket *xs_create_tcp_sock4(struct rpc_xprt *xprt,
1797 		struct sock_xprt *transport)
1798 {
1799 	struct socket *sock;
1800 	int err;
1801 
1802 	/* start from scratch */
1803 	err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1804 	if (err < 0) {
1805 		dprintk("RPC:       can't create TCP transport socket (%d).\n",
1806 				-err);
1807 		goto out_err;
1808 	}
1809 	xs_reclassify_socket4(sock);
1810 
1811 	if (xs_bind4(transport, sock) < 0) {
1812 		sock_release(sock);
1813 		goto out_err;
1814 	}
1815 	return sock;
1816 out_err:
1817 	return ERR_PTR(-EIO);
1818 }
1819 
1820 /**
1821  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1822  * @work: RPC transport to connect
1823  *
1824  * Invoked by a work queue tasklet.
1825  */
1826 static void xs_tcp_connect_worker4(struct work_struct *work)
1827 {
1828 	struct sock_xprt *transport =
1829 		container_of(work, struct sock_xprt, connect_worker.work);
1830 	struct rpc_xprt *xprt = &transport->xprt;
1831 
1832 	xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock4);
1833 }
1834 
1835 static struct socket *xs_create_tcp_sock6(struct rpc_xprt *xprt,
1836 		struct sock_xprt *transport)
1837 {
1838 	struct socket *sock;
1839 	int err;
1840 
1841 	/* start from scratch */
1842 	err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock);
1843 	if (err < 0) {
1844 		dprintk("RPC:       can't create TCP transport socket (%d).\n",
1845 				-err);
1846 		goto out_err;
1847 	}
1848 	xs_reclassify_socket6(sock);
1849 
1850 	if (xs_bind6(transport, sock) < 0) {
1851 		sock_release(sock);
1852 		goto out_err;
1853 	}
1854 	return sock;
1855 out_err:
1856 	return ERR_PTR(-EIO);
1857 }
1858 
1859 /**
1860  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1861  * @work: RPC transport to connect
1862  *
1863  * Invoked by a work queue tasklet.
1864  */
1865 static void xs_tcp_connect_worker6(struct work_struct *work)
1866 {
1867 	struct sock_xprt *transport =
1868 		container_of(work, struct sock_xprt, connect_worker.work);
1869 	struct rpc_xprt *xprt = &transport->xprt;
1870 
1871 	xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock6);
1872 }
1873 
1874 /**
1875  * xs_connect - connect a socket to a remote endpoint
1876  * @task: address of RPC task that manages state of connect request
1877  *
1878  * TCP: If the remote end dropped the connection, delay reconnecting.
1879  *
1880  * UDP socket connects are synchronous, but we use a work queue anyway
1881  * to guarantee that even unprivileged user processes can set up a
1882  * socket on a privileged port.
1883  *
1884  * If a UDP socket connect fails, the delay behavior here prevents
1885  * retry floods (hard mounts).
1886  */
1887 static void xs_connect(struct rpc_task *task)
1888 {
1889 	struct rpc_xprt *xprt = task->tk_xprt;
1890 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1891 
1892 	if (xprt_test_and_set_connecting(xprt))
1893 		return;
1894 
1895 	if (transport->sock != NULL) {
1896 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
1897 				"seconds\n",
1898 				xprt, xprt->reestablish_timeout / HZ);
1899 		queue_delayed_work(rpciod_workqueue,
1900 				   &transport->connect_worker,
1901 				   xprt->reestablish_timeout);
1902 		xprt->reestablish_timeout <<= 1;
1903 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1904 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1905 	} else {
1906 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
1907 		queue_delayed_work(rpciod_workqueue,
1908 				   &transport->connect_worker, 0);
1909 	}
1910 }
1911 
1912 static void xs_tcp_connect(struct rpc_task *task)
1913 {
1914 	struct rpc_xprt *xprt = task->tk_xprt;
1915 
1916 	/* Exit if we need to wait for socket shutdown to complete */
1917 	if (test_bit(XPRT_CLOSING, &xprt->state))
1918 		return;
1919 	xs_connect(task);
1920 }
1921 
1922 /**
1923  * xs_udp_print_stats - display UDP socket-specifc stats
1924  * @xprt: rpc_xprt struct containing statistics
1925  * @seq: output file
1926  *
1927  */
1928 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1929 {
1930 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1931 
1932 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1933 			transport->port,
1934 			xprt->stat.bind_count,
1935 			xprt->stat.sends,
1936 			xprt->stat.recvs,
1937 			xprt->stat.bad_xids,
1938 			xprt->stat.req_u,
1939 			xprt->stat.bklog_u);
1940 }
1941 
1942 /**
1943  * xs_tcp_print_stats - display TCP socket-specifc stats
1944  * @xprt: rpc_xprt struct containing statistics
1945  * @seq: output file
1946  *
1947  */
1948 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1949 {
1950 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1951 	long idle_time = 0;
1952 
1953 	if (xprt_connected(xprt))
1954 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
1955 
1956 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1957 			transport->port,
1958 			xprt->stat.bind_count,
1959 			xprt->stat.connect_count,
1960 			xprt->stat.connect_time,
1961 			idle_time,
1962 			xprt->stat.sends,
1963 			xprt->stat.recvs,
1964 			xprt->stat.bad_xids,
1965 			xprt->stat.req_u,
1966 			xprt->stat.bklog_u);
1967 }
1968 
1969 static struct rpc_xprt_ops xs_udp_ops = {
1970 	.set_buffer_size	= xs_udp_set_buffer_size,
1971 	.reserve_xprt		= xprt_reserve_xprt_cong,
1972 	.release_xprt		= xprt_release_xprt_cong,
1973 	.rpcbind		= rpcb_getport_async,
1974 	.set_port		= xs_set_port,
1975 	.connect		= xs_connect,
1976 	.buf_alloc		= rpc_malloc,
1977 	.buf_free		= rpc_free,
1978 	.send_request		= xs_udp_send_request,
1979 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
1980 	.timer			= xs_udp_timer,
1981 	.release_request	= xprt_release_rqst_cong,
1982 	.close			= xs_close,
1983 	.destroy		= xs_destroy,
1984 	.print_stats		= xs_udp_print_stats,
1985 };
1986 
1987 static struct rpc_xprt_ops xs_tcp_ops = {
1988 	.reserve_xprt		= xprt_reserve_xprt,
1989 	.release_xprt		= xs_tcp_release_xprt,
1990 	.rpcbind		= rpcb_getport_async,
1991 	.set_port		= xs_set_port,
1992 	.connect		= xs_tcp_connect,
1993 	.buf_alloc		= rpc_malloc,
1994 	.buf_free		= rpc_free,
1995 	.send_request		= xs_tcp_send_request,
1996 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
1997 	.close			= xs_tcp_shutdown,
1998 	.destroy		= xs_destroy,
1999 	.print_stats		= xs_tcp_print_stats,
2000 };
2001 
2002 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2003 				      unsigned int slot_table_size)
2004 {
2005 	struct rpc_xprt *xprt;
2006 	struct sock_xprt *new;
2007 
2008 	if (args->addrlen > sizeof(xprt->addr)) {
2009 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2010 		return ERR_PTR(-EBADF);
2011 	}
2012 
2013 	new = kzalloc(sizeof(*new), GFP_KERNEL);
2014 	if (new == NULL) {
2015 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2016 				"rpc_xprt\n");
2017 		return ERR_PTR(-ENOMEM);
2018 	}
2019 	xprt = &new->xprt;
2020 
2021 	xprt->max_reqs = slot_table_size;
2022 	xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
2023 	if (xprt->slot == NULL) {
2024 		kfree(xprt);
2025 		dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
2026 				"table\n");
2027 		return ERR_PTR(-ENOMEM);
2028 	}
2029 
2030 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2031 	xprt->addrlen = args->addrlen;
2032 	if (args->srcaddr)
2033 		memcpy(&new->addr, args->srcaddr, args->addrlen);
2034 
2035 	return xprt;
2036 }
2037 
2038 static const struct rpc_timeout xs_udp_default_timeout = {
2039 	.to_initval = 5 * HZ,
2040 	.to_maxval = 30 * HZ,
2041 	.to_increment = 5 * HZ,
2042 	.to_retries = 5,
2043 };
2044 
2045 /**
2046  * xs_setup_udp - Set up transport to use a UDP socket
2047  * @args: rpc transport creation arguments
2048  *
2049  */
2050 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2051 {
2052 	struct sockaddr *addr = args->dstaddr;
2053 	struct rpc_xprt *xprt;
2054 	struct sock_xprt *transport;
2055 
2056 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
2057 	if (IS_ERR(xprt))
2058 		return xprt;
2059 	transport = container_of(xprt, struct sock_xprt, xprt);
2060 
2061 	xprt->prot = IPPROTO_UDP;
2062 	xprt->tsh_size = 0;
2063 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2064 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2065 
2066 	xprt->bind_timeout = XS_BIND_TO;
2067 	xprt->connect_timeout = XS_UDP_CONN_TO;
2068 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2069 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2070 
2071 	xprt->ops = &xs_udp_ops;
2072 
2073 	xprt->timeout = &xs_udp_default_timeout;
2074 
2075 	switch (addr->sa_family) {
2076 	case AF_INET:
2077 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2078 			xprt_set_bound(xprt);
2079 
2080 		INIT_DELAYED_WORK(&transport->connect_worker,
2081 					xs_udp_connect_worker4);
2082 		xs_format_ipv4_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2083 		break;
2084 	case AF_INET6:
2085 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2086 			xprt_set_bound(xprt);
2087 
2088 		INIT_DELAYED_WORK(&transport->connect_worker,
2089 					xs_udp_connect_worker6);
2090 		xs_format_ipv6_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2091 		break;
2092 	default:
2093 		kfree(xprt);
2094 		return ERR_PTR(-EAFNOSUPPORT);
2095 	}
2096 
2097 	dprintk("RPC:       set up transport to address %s\n",
2098 			xprt->address_strings[RPC_DISPLAY_ALL]);
2099 
2100 	if (try_module_get(THIS_MODULE))
2101 		return xprt;
2102 
2103 	kfree(xprt->slot);
2104 	kfree(xprt);
2105 	return ERR_PTR(-EINVAL);
2106 }
2107 
2108 static const struct rpc_timeout xs_tcp_default_timeout = {
2109 	.to_initval = 60 * HZ,
2110 	.to_maxval = 60 * HZ,
2111 	.to_retries = 2,
2112 };
2113 
2114 /**
2115  * xs_setup_tcp - Set up transport to use a TCP socket
2116  * @args: rpc transport creation arguments
2117  *
2118  */
2119 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2120 {
2121 	struct sockaddr *addr = args->dstaddr;
2122 	struct rpc_xprt *xprt;
2123 	struct sock_xprt *transport;
2124 
2125 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2126 	if (IS_ERR(xprt))
2127 		return xprt;
2128 	transport = container_of(xprt, struct sock_xprt, xprt);
2129 
2130 	xprt->prot = IPPROTO_TCP;
2131 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2132 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2133 
2134 	xprt->bind_timeout = XS_BIND_TO;
2135 	xprt->connect_timeout = XS_TCP_CONN_TO;
2136 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2137 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2138 
2139 	xprt->ops = &xs_tcp_ops;
2140 	xprt->timeout = &xs_tcp_default_timeout;
2141 
2142 	switch (addr->sa_family) {
2143 	case AF_INET:
2144 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2145 			xprt_set_bound(xprt);
2146 
2147 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker4);
2148 		xs_format_ipv4_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2149 		break;
2150 	case AF_INET6:
2151 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2152 			xprt_set_bound(xprt);
2153 
2154 		INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker6);
2155 		xs_format_ipv6_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2156 		break;
2157 	default:
2158 		kfree(xprt);
2159 		return ERR_PTR(-EAFNOSUPPORT);
2160 	}
2161 
2162 	dprintk("RPC:       set up transport to address %s\n",
2163 			xprt->address_strings[RPC_DISPLAY_ALL]);
2164 
2165 	if (try_module_get(THIS_MODULE))
2166 		return xprt;
2167 
2168 	kfree(xprt->slot);
2169 	kfree(xprt);
2170 	return ERR_PTR(-EINVAL);
2171 }
2172 
2173 static struct xprt_class	xs_udp_transport = {
2174 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2175 	.name		= "udp",
2176 	.owner		= THIS_MODULE,
2177 	.ident		= IPPROTO_UDP,
2178 	.setup		= xs_setup_udp,
2179 };
2180 
2181 static struct xprt_class	xs_tcp_transport = {
2182 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2183 	.name		= "tcp",
2184 	.owner		= THIS_MODULE,
2185 	.ident		= IPPROTO_TCP,
2186 	.setup		= xs_setup_tcp,
2187 };
2188 
2189 /**
2190  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2191  *
2192  */
2193 int init_socket_xprt(void)
2194 {
2195 #ifdef RPC_DEBUG
2196 	if (!sunrpc_table_header)
2197 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
2198 #endif
2199 
2200 	xprt_register_transport(&xs_udp_transport);
2201 	xprt_register_transport(&xs_tcp_transport);
2202 
2203 	return 0;
2204 }
2205 
2206 /**
2207  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2208  *
2209  */
2210 void cleanup_socket_xprt(void)
2211 {
2212 #ifdef RPC_DEBUG
2213 	if (sunrpc_table_header) {
2214 		unregister_sysctl_table(sunrpc_table_header);
2215 		sunrpc_table_header = NULL;
2216 	}
2217 #endif
2218 
2219 	xprt_unregister_transport(&xs_udp_transport);
2220 	xprt_unregister_transport(&xs_tcp_transport);
2221 }
2222