xref: /linux/net/sunrpc/xprtsock.c (revision cf2f33a4e54096f90652cca3511fd6a456ea5abe)
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20 
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44 
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49 
50 #include <trace/events/sunrpc.h>
51 
52 #include "sunrpc.h"
53 
54 static void xs_close(struct rpc_xprt *xprt);
55 
56 /*
57  * xprtsock tunables
58  */
59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
62 
63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
65 
66 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
67 
68 #define XS_TCP_LINGER_TO	(15U * HZ)
69 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
70 
71 /*
72  * We can register our own files under /proc/sys/sunrpc by
73  * calling register_sysctl_table() again.  The files in that
74  * directory become the union of all files registered there.
75  *
76  * We simply need to make sure that we don't collide with
77  * someone else's file names!
78  */
79 
80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
85 
86 static struct ctl_table_header *sunrpc_table_header;
87 
88 /*
89  * FIXME: changing the UDP slot table size should also resize the UDP
90  *        socket buffers for existing UDP transports
91  */
92 static struct ctl_table xs_tunables_table[] = {
93 	{
94 		.procname	= "udp_slot_table_entries",
95 		.data		= &xprt_udp_slot_table_entries,
96 		.maxlen		= sizeof(unsigned int),
97 		.mode		= 0644,
98 		.proc_handler	= proc_dointvec_minmax,
99 		.extra1		= &min_slot_table_size,
100 		.extra2		= &max_slot_table_size
101 	},
102 	{
103 		.procname	= "tcp_slot_table_entries",
104 		.data		= &xprt_tcp_slot_table_entries,
105 		.maxlen		= sizeof(unsigned int),
106 		.mode		= 0644,
107 		.proc_handler	= proc_dointvec_minmax,
108 		.extra1		= &min_slot_table_size,
109 		.extra2		= &max_slot_table_size
110 	},
111 	{
112 		.procname	= "tcp_max_slot_table_entries",
113 		.data		= &xprt_max_tcp_slot_table_entries,
114 		.maxlen		= sizeof(unsigned int),
115 		.mode		= 0644,
116 		.proc_handler	= proc_dointvec_minmax,
117 		.extra1		= &min_slot_table_size,
118 		.extra2		= &max_tcp_slot_table_limit
119 	},
120 	{
121 		.procname	= "min_resvport",
122 		.data		= &xprt_min_resvport,
123 		.maxlen		= sizeof(unsigned int),
124 		.mode		= 0644,
125 		.proc_handler	= proc_dointvec_minmax,
126 		.extra1		= &xprt_min_resvport_limit,
127 		.extra2		= &xprt_max_resvport_limit
128 	},
129 	{
130 		.procname	= "max_resvport",
131 		.data		= &xprt_max_resvport,
132 		.maxlen		= sizeof(unsigned int),
133 		.mode		= 0644,
134 		.proc_handler	= proc_dointvec_minmax,
135 		.extra1		= &xprt_min_resvport_limit,
136 		.extra2		= &xprt_max_resvport_limit
137 	},
138 	{
139 		.procname	= "tcp_fin_timeout",
140 		.data		= &xs_tcp_fin_timeout,
141 		.maxlen		= sizeof(xs_tcp_fin_timeout),
142 		.mode		= 0644,
143 		.proc_handler	= proc_dointvec_jiffies,
144 	},
145 	{ },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149 	{
150 		.procname	= "sunrpc",
151 		.mode		= 0555,
152 		.child		= xs_tunables_table
153 	},
154 	{ },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO		(60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO		(2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
180 #define XS_TCP_MAX_REEST_TO	(5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
188 
189 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
190 # undef  RPC_DEBUG_DATA
191 # define RPCDBG_FACILITY	RPCDBG_TRANS
192 #endif
193 
194 #ifdef RPC_DEBUG_DATA
195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
196 {
197 	u8 *buf = (u8 *) packet;
198 	int j;
199 
200 	dprintk("RPC:       %s\n", msg);
201 	for (j = 0; j < count && j < 128; j += 4) {
202 		if (!(j & 31)) {
203 			if (j)
204 				dprintk("\n");
205 			dprintk("0x%04x ", j);
206 		}
207 		dprintk("%02x%02x%02x%02x ",
208 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
209 	}
210 	dprintk("\n");
211 }
212 #else
213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
214 {
215 	/* NOP */
216 }
217 #endif
218 
219 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
220 {
221 	return (struct rpc_xprt *) sk->sk_user_data;
222 }
223 
224 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
225 {
226 	return (struct sockaddr *) &xprt->addr;
227 }
228 
229 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
230 {
231 	return (struct sockaddr_un *) &xprt->addr;
232 }
233 
234 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
235 {
236 	return (struct sockaddr_in *) &xprt->addr;
237 }
238 
239 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
240 {
241 	return (struct sockaddr_in6 *) &xprt->addr;
242 }
243 
244 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
245 {
246 	struct sockaddr *sap = xs_addr(xprt);
247 	struct sockaddr_in6 *sin6;
248 	struct sockaddr_in *sin;
249 	struct sockaddr_un *sun;
250 	char buf[128];
251 
252 	switch (sap->sa_family) {
253 	case AF_LOCAL:
254 		sun = xs_addr_un(xprt);
255 		strlcpy(buf, sun->sun_path, sizeof(buf));
256 		xprt->address_strings[RPC_DISPLAY_ADDR] =
257 						kstrdup(buf, GFP_KERNEL);
258 		break;
259 	case AF_INET:
260 		(void)rpc_ntop(sap, buf, sizeof(buf));
261 		xprt->address_strings[RPC_DISPLAY_ADDR] =
262 						kstrdup(buf, GFP_KERNEL);
263 		sin = xs_addr_in(xprt);
264 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
265 		break;
266 	case AF_INET6:
267 		(void)rpc_ntop(sap, buf, sizeof(buf));
268 		xprt->address_strings[RPC_DISPLAY_ADDR] =
269 						kstrdup(buf, GFP_KERNEL);
270 		sin6 = xs_addr_in6(xprt);
271 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
272 		break;
273 	default:
274 		BUG();
275 	}
276 
277 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
278 }
279 
280 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
281 {
282 	struct sockaddr *sap = xs_addr(xprt);
283 	char buf[128];
284 
285 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
286 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
287 
288 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
290 }
291 
292 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
293 				     const char *protocol,
294 				     const char *netid)
295 {
296 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
297 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
298 	xs_format_common_peer_addresses(xprt);
299 	xs_format_common_peer_ports(xprt);
300 }
301 
302 static void xs_update_peer_port(struct rpc_xprt *xprt)
303 {
304 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
305 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
306 
307 	xs_format_common_peer_ports(xprt);
308 }
309 
310 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
311 {
312 	unsigned int i;
313 
314 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
315 		switch (i) {
316 		case RPC_DISPLAY_PROTO:
317 		case RPC_DISPLAY_NETID:
318 			continue;
319 		default:
320 			kfree(xprt->address_strings[i]);
321 		}
322 }
323 
324 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
325 
326 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
327 {
328 	struct msghdr msg = {
329 		.msg_name	= addr,
330 		.msg_namelen	= addrlen,
331 		.msg_flags	= XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
332 	};
333 	struct kvec iov = {
334 		.iov_base	= vec->iov_base + base,
335 		.iov_len	= vec->iov_len - base,
336 	};
337 
338 	if (iov.iov_len != 0)
339 		return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
340 	return kernel_sendmsg(sock, &msg, NULL, 0, 0);
341 }
342 
343 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
344 {
345 	ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
346 			int offset, size_t size, int flags);
347 	struct page **ppage;
348 	unsigned int remainder;
349 	int err;
350 
351 	remainder = xdr->page_len - base;
352 	base += xdr->page_base;
353 	ppage = xdr->pages + (base >> PAGE_SHIFT);
354 	base &= ~PAGE_MASK;
355 	do_sendpage = sock->ops->sendpage;
356 	if (!zerocopy)
357 		do_sendpage = sock_no_sendpage;
358 	for(;;) {
359 		unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
360 		int flags = XS_SENDMSG_FLAGS;
361 
362 		remainder -= len;
363 		if (remainder != 0 || more)
364 			flags |= MSG_MORE;
365 		err = do_sendpage(sock, *ppage, base, len, flags);
366 		if (remainder == 0 || err != len)
367 			break;
368 		*sent_p += err;
369 		ppage++;
370 		base = 0;
371 	}
372 	if (err > 0) {
373 		*sent_p += err;
374 		err = 0;
375 	}
376 	return err;
377 }
378 
379 /**
380  * xs_sendpages - write pages directly to a socket
381  * @sock: socket to send on
382  * @addr: UDP only -- address of destination
383  * @addrlen: UDP only -- length of destination address
384  * @xdr: buffer containing this request
385  * @base: starting position in the buffer
386  * @zerocopy: true if it is safe to use sendpage()
387  * @sent_p: return the total number of bytes successfully queued for sending
388  *
389  */
390 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
391 {
392 	unsigned int remainder = xdr->len - base;
393 	int err = 0;
394 	int sent = 0;
395 
396 	if (unlikely(!sock))
397 		return -ENOTSOCK;
398 
399 	clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
400 	if (base != 0) {
401 		addr = NULL;
402 		addrlen = 0;
403 	}
404 
405 	if (base < xdr->head[0].iov_len || addr != NULL) {
406 		unsigned int len = xdr->head[0].iov_len - base;
407 		remainder -= len;
408 		err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
409 		if (remainder == 0 || err != len)
410 			goto out;
411 		*sent_p += err;
412 		base = 0;
413 	} else
414 		base -= xdr->head[0].iov_len;
415 
416 	if (base < xdr->page_len) {
417 		unsigned int len = xdr->page_len - base;
418 		remainder -= len;
419 		err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
420 		*sent_p += sent;
421 		if (remainder == 0 || sent != len)
422 			goto out;
423 		base = 0;
424 	} else
425 		base -= xdr->page_len;
426 
427 	if (base >= xdr->tail[0].iov_len)
428 		return 0;
429 	err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
430 out:
431 	if (err > 0) {
432 		*sent_p += err;
433 		err = 0;
434 	}
435 	return err;
436 }
437 
438 static void xs_nospace_callback(struct rpc_task *task)
439 {
440 	struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
441 
442 	transport->inet->sk_write_pending--;
443 	clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
444 }
445 
446 /**
447  * xs_nospace - place task on wait queue if transmit was incomplete
448  * @task: task to put to sleep
449  *
450  */
451 static int xs_nospace(struct rpc_task *task)
452 {
453 	struct rpc_rqst *req = task->tk_rqstp;
454 	struct rpc_xprt *xprt = req->rq_xprt;
455 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
456 	struct sock *sk = transport->inet;
457 	int ret = -EAGAIN;
458 
459 	dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
460 			task->tk_pid, req->rq_slen - req->rq_bytes_sent,
461 			req->rq_slen);
462 
463 	/* Protect against races with write_space */
464 	spin_lock_bh(&xprt->transport_lock);
465 
466 	/* Don't race with disconnect */
467 	if (xprt_connected(xprt)) {
468 		if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
469 			/*
470 			 * Notify TCP that we're limited by the application
471 			 * window size
472 			 */
473 			set_bit(SOCK_NOSPACE, &transport->sock->flags);
474 			sk->sk_write_pending++;
475 			/* ...and wait for more buffer space */
476 			xprt_wait_for_buffer_space(task, xs_nospace_callback);
477 		}
478 	} else {
479 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
480 		ret = -ENOTCONN;
481 	}
482 
483 	spin_unlock_bh(&xprt->transport_lock);
484 
485 	/* Race breaker in case memory is freed before above code is called */
486 	sk->sk_write_space(sk);
487 	return ret;
488 }
489 
490 /*
491  * Construct a stream transport record marker in @buf.
492  */
493 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
494 {
495 	u32 reclen = buf->len - sizeof(rpc_fraghdr);
496 	rpc_fraghdr *base = buf->head[0].iov_base;
497 	*base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
498 }
499 
500 /**
501  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
502  * @task: RPC task that manages the state of an RPC request
503  *
504  * Return values:
505  *        0:	The request has been sent
506  *   EAGAIN:	The socket was blocked, please call again later to
507  *		complete the request
508  * ENOTCONN:	Caller needs to invoke connect logic then call again
509  *    other:	Some other error occured, the request was not sent
510  */
511 static int xs_local_send_request(struct rpc_task *task)
512 {
513 	struct rpc_rqst *req = task->tk_rqstp;
514 	struct rpc_xprt *xprt = req->rq_xprt;
515 	struct sock_xprt *transport =
516 				container_of(xprt, struct sock_xprt, xprt);
517 	struct xdr_buf *xdr = &req->rq_snd_buf;
518 	int status;
519 	int sent = 0;
520 
521 	xs_encode_stream_record_marker(&req->rq_snd_buf);
522 
523 	xs_pktdump("packet data:",
524 			req->rq_svec->iov_base, req->rq_svec->iov_len);
525 
526 	status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
527 			      true, &sent);
528 	dprintk("RPC:       %s(%u) = %d\n",
529 			__func__, xdr->len - req->rq_bytes_sent, status);
530 
531 	if (status == -EAGAIN && sock_writeable(transport->inet))
532 		status = -ENOBUFS;
533 
534 	if (likely(sent > 0) || status == 0) {
535 		req->rq_bytes_sent += sent;
536 		req->rq_xmit_bytes_sent += sent;
537 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
538 			req->rq_bytes_sent = 0;
539 			return 0;
540 		}
541 		status = -EAGAIN;
542 	}
543 
544 	switch (status) {
545 	case -ENOBUFS:
546 		break;
547 	case -EAGAIN:
548 		status = xs_nospace(task);
549 		break;
550 	default:
551 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
552 			-status);
553 	case -EPIPE:
554 		xs_close(xprt);
555 		status = -ENOTCONN;
556 	}
557 
558 	return status;
559 }
560 
561 /**
562  * xs_udp_send_request - write an RPC request to a UDP socket
563  * @task: address of RPC task that manages the state of an RPC request
564  *
565  * Return values:
566  *        0:	The request has been sent
567  *   EAGAIN:	The socket was blocked, please call again later to
568  *		complete the request
569  * ENOTCONN:	Caller needs to invoke connect logic then call again
570  *    other:	Some other error occurred, the request was not sent
571  */
572 static int xs_udp_send_request(struct rpc_task *task)
573 {
574 	struct rpc_rqst *req = task->tk_rqstp;
575 	struct rpc_xprt *xprt = req->rq_xprt;
576 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
577 	struct xdr_buf *xdr = &req->rq_snd_buf;
578 	int sent = 0;
579 	int status;
580 
581 	xs_pktdump("packet data:",
582 				req->rq_svec->iov_base,
583 				req->rq_svec->iov_len);
584 
585 	if (!xprt_bound(xprt))
586 		return -ENOTCONN;
587 	status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
588 			      xdr, req->rq_bytes_sent, true, &sent);
589 
590 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
591 			xdr->len - req->rq_bytes_sent, status);
592 
593 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
594 	if (status == -EPERM)
595 		goto process_status;
596 
597 	if (status == -EAGAIN && sock_writeable(transport->inet))
598 		status = -ENOBUFS;
599 
600 	if (sent > 0 || status == 0) {
601 		req->rq_xmit_bytes_sent += sent;
602 		if (sent >= req->rq_slen)
603 			return 0;
604 		/* Still some bytes left; set up for a retry later. */
605 		status = -EAGAIN;
606 	}
607 
608 process_status:
609 	switch (status) {
610 	case -ENOTSOCK:
611 		status = -ENOTCONN;
612 		/* Should we call xs_close() here? */
613 		break;
614 	case -EAGAIN:
615 		status = xs_nospace(task);
616 		break;
617 	default:
618 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
619 			-status);
620 	case -ENETUNREACH:
621 	case -ENOBUFS:
622 	case -EPIPE:
623 	case -ECONNREFUSED:
624 	case -EPERM:
625 		/* When the server has died, an ICMP port unreachable message
626 		 * prompts ECONNREFUSED. */
627 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
628 	}
629 
630 	return status;
631 }
632 
633 /**
634  * xs_tcp_send_request - write an RPC request to a TCP socket
635  * @task: address of RPC task that manages the state of an RPC request
636  *
637  * Return values:
638  *        0:	The request has been sent
639  *   EAGAIN:	The socket was blocked, please call again later to
640  *		complete the request
641  * ENOTCONN:	Caller needs to invoke connect logic then call again
642  *    other:	Some other error occurred, the request was not sent
643  *
644  * XXX: In the case of soft timeouts, should we eventually give up
645  *	if sendmsg is not able to make progress?
646  */
647 static int xs_tcp_send_request(struct rpc_task *task)
648 {
649 	struct rpc_rqst *req = task->tk_rqstp;
650 	struct rpc_xprt *xprt = req->rq_xprt;
651 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
652 	struct xdr_buf *xdr = &req->rq_snd_buf;
653 	bool zerocopy = true;
654 	int status;
655 	int sent;
656 
657 	xs_encode_stream_record_marker(&req->rq_snd_buf);
658 
659 	xs_pktdump("packet data:",
660 				req->rq_svec->iov_base,
661 				req->rq_svec->iov_len);
662 	/* Don't use zero copy if this is a resend. If the RPC call
663 	 * completes while the socket holds a reference to the pages,
664 	 * then we may end up resending corrupted data.
665 	 */
666 	if (task->tk_flags & RPC_TASK_SENT)
667 		zerocopy = false;
668 
669 	/* Continue transmitting the packet/record. We must be careful
670 	 * to cope with writespace callbacks arriving _after_ we have
671 	 * called sendmsg(). */
672 	while (1) {
673 		sent = 0;
674 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
675 				      req->rq_bytes_sent, zerocopy, &sent);
676 
677 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
678 				xdr->len - req->rq_bytes_sent, status);
679 
680 		/* If we've sent the entire packet, immediately
681 		 * reset the count of bytes sent. */
682 		req->rq_bytes_sent += sent;
683 		req->rq_xmit_bytes_sent += sent;
684 		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
685 			req->rq_bytes_sent = 0;
686 			return 0;
687 		}
688 
689 		if (status < 0)
690 			break;
691 		if (sent == 0) {
692 			status = -EAGAIN;
693 			break;
694 		}
695 	}
696 	if (status == -EAGAIN && sk_stream_is_writeable(transport->inet))
697 		status = -ENOBUFS;
698 
699 	switch (status) {
700 	case -ENOTSOCK:
701 		status = -ENOTCONN;
702 		/* Should we call xs_close() here? */
703 		break;
704 	case -EAGAIN:
705 		status = xs_nospace(task);
706 		break;
707 	default:
708 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
709 			-status);
710 	case -ECONNRESET:
711 	case -ECONNREFUSED:
712 	case -ENOTCONN:
713 	case -EADDRINUSE:
714 	case -ENOBUFS:
715 	case -EPIPE:
716 		clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
717 	}
718 
719 	return status;
720 }
721 
722 /**
723  * xs_tcp_release_xprt - clean up after a tcp transmission
724  * @xprt: transport
725  * @task: rpc task
726  *
727  * This cleans up if an error causes us to abort the transmission of a request.
728  * In this case, the socket may need to be reset in order to avoid confusing
729  * the server.
730  */
731 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
732 {
733 	struct rpc_rqst *req;
734 
735 	if (task != xprt->snd_task)
736 		return;
737 	if (task == NULL)
738 		goto out_release;
739 	req = task->tk_rqstp;
740 	if (req == NULL)
741 		goto out_release;
742 	if (req->rq_bytes_sent == 0)
743 		goto out_release;
744 	if (req->rq_bytes_sent == req->rq_snd_buf.len)
745 		goto out_release;
746 	set_bit(XPRT_CLOSE_WAIT, &xprt->state);
747 out_release:
748 	xprt_release_xprt(xprt, task);
749 }
750 
751 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
752 {
753 	transport->old_data_ready = sk->sk_data_ready;
754 	transport->old_state_change = sk->sk_state_change;
755 	transport->old_write_space = sk->sk_write_space;
756 	transport->old_error_report = sk->sk_error_report;
757 }
758 
759 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
760 {
761 	sk->sk_data_ready = transport->old_data_ready;
762 	sk->sk_state_change = transport->old_state_change;
763 	sk->sk_write_space = transport->old_write_space;
764 	sk->sk_error_report = transport->old_error_report;
765 }
766 
767 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
768 {
769 	smp_mb__before_atomic();
770 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
771 	clear_bit(XPRT_CLOSING, &xprt->state);
772 	smp_mb__after_atomic();
773 }
774 
775 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
776 {
777 	xs_sock_reset_connection_flags(xprt);
778 	/* Mark transport as closed and wake up all pending tasks */
779 	xprt_disconnect_done(xprt);
780 	xprt_force_disconnect(xprt);
781 }
782 
783 /**
784  * xs_error_report - callback to handle TCP socket state errors
785  * @sk: socket
786  *
787  * Note: we don't call sock_error() since there may be a rpc_task
788  * using the socket, and so we don't want to clear sk->sk_err.
789  */
790 static void xs_error_report(struct sock *sk)
791 {
792 	struct rpc_xprt *xprt;
793 	int err;
794 
795 	read_lock_bh(&sk->sk_callback_lock);
796 	if (!(xprt = xprt_from_sock(sk)))
797 		goto out;
798 
799 	err = -sk->sk_err;
800 	if (err == 0)
801 		goto out;
802 	/* Is this a reset event? */
803 	if (sk->sk_state == TCP_CLOSE)
804 		xs_sock_mark_closed(xprt);
805 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
806 			xprt, -err);
807 	trace_rpc_socket_error(xprt, sk->sk_socket, err);
808 	xprt_wake_pending_tasks(xprt, err);
809  out:
810 	read_unlock_bh(&sk->sk_callback_lock);
811 }
812 
813 static void xs_reset_transport(struct sock_xprt *transport)
814 {
815 	struct socket *sock = transport->sock;
816 	struct sock *sk = transport->inet;
817 	struct rpc_xprt *xprt = &transport->xprt;
818 
819 	if (sk == NULL)
820 		return;
821 
822 	if (atomic_read(&transport->xprt.swapper))
823 		sk_clear_memalloc(sk);
824 
825 	write_lock_bh(&sk->sk_callback_lock);
826 	transport->inet = NULL;
827 	transport->sock = NULL;
828 
829 	sk->sk_user_data = NULL;
830 
831 	xs_restore_old_callbacks(transport, sk);
832 	write_unlock_bh(&sk->sk_callback_lock);
833 	xs_sock_reset_connection_flags(xprt);
834 
835 	trace_rpc_socket_close(xprt, sock);
836 	sock_release(sock);
837 }
838 
839 /**
840  * xs_close - close a socket
841  * @xprt: transport
842  *
843  * This is used when all requests are complete; ie, no DRC state remains
844  * on the server we want to save.
845  *
846  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
847  * xs_reset_transport() zeroing the socket from underneath a writer.
848  */
849 static void xs_close(struct rpc_xprt *xprt)
850 {
851 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
852 
853 	dprintk("RPC:       xs_close xprt %p\n", xprt);
854 
855 	xs_reset_transport(transport);
856 	xprt->reestablish_timeout = 0;
857 
858 	xprt_disconnect_done(xprt);
859 }
860 
861 static void xs_inject_disconnect(struct rpc_xprt *xprt)
862 {
863 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
864 		xprt);
865 	xprt_disconnect_done(xprt);
866 }
867 
868 static void xs_xprt_free(struct rpc_xprt *xprt)
869 {
870 	xs_free_peer_addresses(xprt);
871 	xprt_free(xprt);
872 }
873 
874 /**
875  * xs_destroy - prepare to shutdown a transport
876  * @xprt: doomed transport
877  *
878  */
879 static void xs_destroy(struct rpc_xprt *xprt)
880 {
881 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
882 
883 	xs_close(xprt);
884 	xs_xprt_free(xprt);
885 	module_put(THIS_MODULE);
886 }
887 
888 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
889 {
890 	struct xdr_skb_reader desc = {
891 		.skb		= skb,
892 		.offset		= sizeof(rpc_fraghdr),
893 		.count		= skb->len - sizeof(rpc_fraghdr),
894 	};
895 
896 	if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
897 		return -1;
898 	if (desc.count)
899 		return -1;
900 	return 0;
901 }
902 
903 /**
904  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
905  * @sk: socket with data to read
906  *
907  * Currently this assumes we can read the whole reply in a single gulp.
908  */
909 static void xs_local_data_ready(struct sock *sk)
910 {
911 	struct rpc_task *task;
912 	struct rpc_xprt *xprt;
913 	struct rpc_rqst *rovr;
914 	struct sk_buff *skb;
915 	int err, repsize, copied;
916 	u32 _xid;
917 	__be32 *xp;
918 
919 	read_lock_bh(&sk->sk_callback_lock);
920 	dprintk("RPC:       %s...\n", __func__);
921 	xprt = xprt_from_sock(sk);
922 	if (xprt == NULL)
923 		goto out;
924 
925 	skb = skb_recv_datagram(sk, 0, 1, &err);
926 	if (skb == NULL)
927 		goto out;
928 
929 	repsize = skb->len - sizeof(rpc_fraghdr);
930 	if (repsize < 4) {
931 		dprintk("RPC:       impossible RPC reply size %d\n", repsize);
932 		goto dropit;
933 	}
934 
935 	/* Copy the XID from the skb... */
936 	xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
937 	if (xp == NULL)
938 		goto dropit;
939 
940 	/* Look up and lock the request corresponding to the given XID */
941 	spin_lock(&xprt->transport_lock);
942 	rovr = xprt_lookup_rqst(xprt, *xp);
943 	if (!rovr)
944 		goto out_unlock;
945 	task = rovr->rq_task;
946 
947 	copied = rovr->rq_private_buf.buflen;
948 	if (copied > repsize)
949 		copied = repsize;
950 
951 	if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
952 		dprintk("RPC:       sk_buff copy failed\n");
953 		goto out_unlock;
954 	}
955 
956 	xprt_complete_rqst(task, copied);
957 
958  out_unlock:
959 	spin_unlock(&xprt->transport_lock);
960  dropit:
961 	skb_free_datagram(sk, skb);
962  out:
963 	read_unlock_bh(&sk->sk_callback_lock);
964 }
965 
966 /**
967  * xs_udp_data_ready - "data ready" callback for UDP sockets
968  * @sk: socket with data to read
969  *
970  */
971 static void xs_udp_data_ready(struct sock *sk)
972 {
973 	struct rpc_task *task;
974 	struct rpc_xprt *xprt;
975 	struct rpc_rqst *rovr;
976 	struct sk_buff *skb;
977 	int err, repsize, copied;
978 	u32 _xid;
979 	__be32 *xp;
980 
981 	read_lock_bh(&sk->sk_callback_lock);
982 	dprintk("RPC:       xs_udp_data_ready...\n");
983 	if (!(xprt = xprt_from_sock(sk)))
984 		goto out;
985 
986 	if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
987 		goto out;
988 
989 	repsize = skb->len - sizeof(struct udphdr);
990 	if (repsize < 4) {
991 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
992 		goto dropit;
993 	}
994 
995 	/* Copy the XID from the skb... */
996 	xp = skb_header_pointer(skb, sizeof(struct udphdr),
997 				sizeof(_xid), &_xid);
998 	if (xp == NULL)
999 		goto dropit;
1000 
1001 	/* Look up and lock the request corresponding to the given XID */
1002 	spin_lock(&xprt->transport_lock);
1003 	rovr = xprt_lookup_rqst(xprt, *xp);
1004 	if (!rovr)
1005 		goto out_unlock;
1006 	task = rovr->rq_task;
1007 
1008 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1009 		copied = repsize;
1010 
1011 	/* Suck it into the iovec, verify checksum if not done by hw. */
1012 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1013 		UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1014 		goto out_unlock;
1015 	}
1016 
1017 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1018 
1019 	xprt_adjust_cwnd(xprt, task, copied);
1020 	xprt_complete_rqst(task, copied);
1021 
1022  out_unlock:
1023 	spin_unlock(&xprt->transport_lock);
1024  dropit:
1025 	skb_free_datagram(sk, skb);
1026  out:
1027 	read_unlock_bh(&sk->sk_callback_lock);
1028 }
1029 
1030 /*
1031  * Helper function to force a TCP close if the server is sending
1032  * junk and/or it has put us in CLOSE_WAIT
1033  */
1034 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1035 {
1036 	xprt_force_disconnect(xprt);
1037 }
1038 
1039 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1040 {
1041 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1042 	size_t len, used;
1043 	char *p;
1044 
1045 	p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1046 	len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1047 	used = xdr_skb_read_bits(desc, p, len);
1048 	transport->tcp_offset += used;
1049 	if (used != len)
1050 		return;
1051 
1052 	transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1053 	if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1054 		transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1055 	else
1056 		transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1057 	transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1058 
1059 	transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1060 	transport->tcp_offset = 0;
1061 
1062 	/* Sanity check of the record length */
1063 	if (unlikely(transport->tcp_reclen < 8)) {
1064 		dprintk("RPC:       invalid TCP record fragment length\n");
1065 		xs_tcp_force_close(xprt);
1066 		return;
1067 	}
1068 	dprintk("RPC:       reading TCP record fragment of length %d\n",
1069 			transport->tcp_reclen);
1070 }
1071 
1072 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1073 {
1074 	if (transport->tcp_offset == transport->tcp_reclen) {
1075 		transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1076 		transport->tcp_offset = 0;
1077 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1078 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1079 			transport->tcp_flags |= TCP_RCV_COPY_XID;
1080 			transport->tcp_copied = 0;
1081 		}
1082 	}
1083 }
1084 
1085 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1086 {
1087 	size_t len, used;
1088 	char *p;
1089 
1090 	len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1091 	dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1092 	p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1093 	used = xdr_skb_read_bits(desc, p, len);
1094 	transport->tcp_offset += used;
1095 	if (used != len)
1096 		return;
1097 	transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1098 	transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1099 	transport->tcp_copied = 4;
1100 	dprintk("RPC:       reading %s XID %08x\n",
1101 			(transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1102 							      : "request with",
1103 			ntohl(transport->tcp_xid));
1104 	xs_tcp_check_fraghdr(transport);
1105 }
1106 
1107 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1108 				       struct xdr_skb_reader *desc)
1109 {
1110 	size_t len, used;
1111 	u32 offset;
1112 	char *p;
1113 
1114 	/*
1115 	 * We want transport->tcp_offset to be 8 at the end of this routine
1116 	 * (4 bytes for the xid and 4 bytes for the call/reply flag).
1117 	 * When this function is called for the first time,
1118 	 * transport->tcp_offset is 4 (after having already read the xid).
1119 	 */
1120 	offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1121 	len = sizeof(transport->tcp_calldir) - offset;
1122 	dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1123 	p = ((char *) &transport->tcp_calldir) + offset;
1124 	used = xdr_skb_read_bits(desc, p, len);
1125 	transport->tcp_offset += used;
1126 	if (used != len)
1127 		return;
1128 	transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1129 	/*
1130 	 * We don't yet have the XDR buffer, so we will write the calldir
1131 	 * out after we get the buffer from the 'struct rpc_rqst'
1132 	 */
1133 	switch (ntohl(transport->tcp_calldir)) {
1134 	case RPC_REPLY:
1135 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1136 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1137 		transport->tcp_flags |= TCP_RPC_REPLY;
1138 		break;
1139 	case RPC_CALL:
1140 		transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1141 		transport->tcp_flags |= TCP_RCV_COPY_DATA;
1142 		transport->tcp_flags &= ~TCP_RPC_REPLY;
1143 		break;
1144 	default:
1145 		dprintk("RPC:       invalid request message type\n");
1146 		xs_tcp_force_close(&transport->xprt);
1147 	}
1148 	xs_tcp_check_fraghdr(transport);
1149 }
1150 
1151 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1152 				     struct xdr_skb_reader *desc,
1153 				     struct rpc_rqst *req)
1154 {
1155 	struct sock_xprt *transport =
1156 				container_of(xprt, struct sock_xprt, xprt);
1157 	struct xdr_buf *rcvbuf;
1158 	size_t len;
1159 	ssize_t r;
1160 
1161 	rcvbuf = &req->rq_private_buf;
1162 
1163 	if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1164 		/*
1165 		 * Save the RPC direction in the XDR buffer
1166 		 */
1167 		memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1168 			&transport->tcp_calldir,
1169 			sizeof(transport->tcp_calldir));
1170 		transport->tcp_copied += sizeof(transport->tcp_calldir);
1171 		transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1172 	}
1173 
1174 	len = desc->count;
1175 	if (len > transport->tcp_reclen - transport->tcp_offset) {
1176 		struct xdr_skb_reader my_desc;
1177 
1178 		len = transport->tcp_reclen - transport->tcp_offset;
1179 		memcpy(&my_desc, desc, sizeof(my_desc));
1180 		my_desc.count = len;
1181 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1182 					  &my_desc, xdr_skb_read_bits);
1183 		desc->count -= r;
1184 		desc->offset += r;
1185 	} else
1186 		r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1187 					  desc, xdr_skb_read_bits);
1188 
1189 	if (r > 0) {
1190 		transport->tcp_copied += r;
1191 		transport->tcp_offset += r;
1192 	}
1193 	if (r != len) {
1194 		/* Error when copying to the receive buffer,
1195 		 * usually because we weren't able to allocate
1196 		 * additional buffer pages. All we can do now
1197 		 * is turn off TCP_RCV_COPY_DATA, so the request
1198 		 * will not receive any additional updates,
1199 		 * and time out.
1200 		 * Any remaining data from this record will
1201 		 * be discarded.
1202 		 */
1203 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1204 		dprintk("RPC:       XID %08x truncated request\n",
1205 				ntohl(transport->tcp_xid));
1206 		dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1207 				"tcp_offset = %u, tcp_reclen = %u\n",
1208 				xprt, transport->tcp_copied,
1209 				transport->tcp_offset, transport->tcp_reclen);
1210 		return;
1211 	}
1212 
1213 	dprintk("RPC:       XID %08x read %Zd bytes\n",
1214 			ntohl(transport->tcp_xid), r);
1215 	dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1216 			"tcp_reclen = %u\n", xprt, transport->tcp_copied,
1217 			transport->tcp_offset, transport->tcp_reclen);
1218 
1219 	if (transport->tcp_copied == req->rq_private_buf.buflen)
1220 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1221 	else if (transport->tcp_offset == transport->tcp_reclen) {
1222 		if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1223 			transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1224 	}
1225 }
1226 
1227 /*
1228  * Finds the request corresponding to the RPC xid and invokes the common
1229  * tcp read code to read the data.
1230  */
1231 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1232 				    struct xdr_skb_reader *desc)
1233 {
1234 	struct sock_xprt *transport =
1235 				container_of(xprt, struct sock_xprt, xprt);
1236 	struct rpc_rqst *req;
1237 
1238 	dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1239 
1240 	/* Find and lock the request corresponding to this xid */
1241 	spin_lock(&xprt->transport_lock);
1242 	req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1243 	if (!req) {
1244 		dprintk("RPC:       XID %08x request not found!\n",
1245 				ntohl(transport->tcp_xid));
1246 		spin_unlock(&xprt->transport_lock);
1247 		return -1;
1248 	}
1249 
1250 	xs_tcp_read_common(xprt, desc, req);
1251 
1252 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1253 		xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1254 
1255 	spin_unlock(&xprt->transport_lock);
1256 	return 0;
1257 }
1258 
1259 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1260 /*
1261  * Obtains an rpc_rqst previously allocated and invokes the common
1262  * tcp read code to read the data.  The result is placed in the callback
1263  * queue.
1264  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1265  * connection and return -1.
1266  */
1267 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1268 				       struct xdr_skb_reader *desc)
1269 {
1270 	struct sock_xprt *transport =
1271 				container_of(xprt, struct sock_xprt, xprt);
1272 	struct rpc_rqst *req;
1273 
1274 	/* Look up and lock the request corresponding to the given XID */
1275 	spin_lock(&xprt->transport_lock);
1276 	req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1277 	if (req == NULL) {
1278 		spin_unlock(&xprt->transport_lock);
1279 		printk(KERN_WARNING "Callback slot table overflowed\n");
1280 		xprt_force_disconnect(xprt);
1281 		return -1;
1282 	}
1283 
1284 	dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1285 	xs_tcp_read_common(xprt, desc, req);
1286 
1287 	if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1288 		xprt_complete_bc_request(req, transport->tcp_copied);
1289 	spin_unlock(&xprt->transport_lock);
1290 
1291 	return 0;
1292 }
1293 
1294 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1295 					struct xdr_skb_reader *desc)
1296 {
1297 	struct sock_xprt *transport =
1298 				container_of(xprt, struct sock_xprt, xprt);
1299 
1300 	return (transport->tcp_flags & TCP_RPC_REPLY) ?
1301 		xs_tcp_read_reply(xprt, desc) :
1302 		xs_tcp_read_callback(xprt, desc);
1303 }
1304 #else
1305 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1306 					struct xdr_skb_reader *desc)
1307 {
1308 	return xs_tcp_read_reply(xprt, desc);
1309 }
1310 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1311 
1312 /*
1313  * Read data off the transport.  This can be either an RPC_CALL or an
1314  * RPC_REPLY.  Relay the processing to helper functions.
1315  */
1316 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1317 				    struct xdr_skb_reader *desc)
1318 {
1319 	struct sock_xprt *transport =
1320 				container_of(xprt, struct sock_xprt, xprt);
1321 
1322 	if (_xs_tcp_read_data(xprt, desc) == 0)
1323 		xs_tcp_check_fraghdr(transport);
1324 	else {
1325 		/*
1326 		 * The transport_lock protects the request handling.
1327 		 * There's no need to hold it to update the tcp_flags.
1328 		 */
1329 		transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1330 	}
1331 }
1332 
1333 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1334 {
1335 	size_t len;
1336 
1337 	len = transport->tcp_reclen - transport->tcp_offset;
1338 	if (len > desc->count)
1339 		len = desc->count;
1340 	desc->count -= len;
1341 	desc->offset += len;
1342 	transport->tcp_offset += len;
1343 	dprintk("RPC:       discarded %Zu bytes\n", len);
1344 	xs_tcp_check_fraghdr(transport);
1345 }
1346 
1347 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1348 {
1349 	struct rpc_xprt *xprt = rd_desc->arg.data;
1350 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1351 	struct xdr_skb_reader desc = {
1352 		.skb	= skb,
1353 		.offset	= offset,
1354 		.count	= len,
1355 	};
1356 
1357 	dprintk("RPC:       xs_tcp_data_recv started\n");
1358 	do {
1359 		trace_xs_tcp_data_recv(transport);
1360 		/* Read in a new fragment marker if necessary */
1361 		/* Can we ever really expect to get completely empty fragments? */
1362 		if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1363 			xs_tcp_read_fraghdr(xprt, &desc);
1364 			continue;
1365 		}
1366 		/* Read in the xid if necessary */
1367 		if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1368 			xs_tcp_read_xid(transport, &desc);
1369 			continue;
1370 		}
1371 		/* Read in the call/reply flag */
1372 		if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1373 			xs_tcp_read_calldir(transport, &desc);
1374 			continue;
1375 		}
1376 		/* Read in the request data */
1377 		if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1378 			xs_tcp_read_data(xprt, &desc);
1379 			continue;
1380 		}
1381 		/* Skip over any trailing bytes on short reads */
1382 		xs_tcp_read_discard(transport, &desc);
1383 	} while (desc.count);
1384 	trace_xs_tcp_data_recv(transport);
1385 	dprintk("RPC:       xs_tcp_data_recv done\n");
1386 	return len - desc.count;
1387 }
1388 
1389 /**
1390  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1391  * @sk: socket with data to read
1392  *
1393  */
1394 static void xs_tcp_data_ready(struct sock *sk)
1395 {
1396 	struct rpc_xprt *xprt;
1397 	read_descriptor_t rd_desc;
1398 	int read;
1399 	unsigned long total = 0;
1400 
1401 	dprintk("RPC:       xs_tcp_data_ready...\n");
1402 
1403 	read_lock_bh(&sk->sk_callback_lock);
1404 	if (!(xprt = xprt_from_sock(sk))) {
1405 		read = 0;
1406 		goto out;
1407 	}
1408 	/* Any data means we had a useful conversation, so
1409 	 * the we don't need to delay the next reconnect
1410 	 */
1411 	if (xprt->reestablish_timeout)
1412 		xprt->reestablish_timeout = 0;
1413 
1414 	/* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1415 	rd_desc.arg.data = xprt;
1416 	do {
1417 		rd_desc.count = 65536;
1418 		read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1419 		if (read > 0)
1420 			total += read;
1421 	} while (read > 0);
1422 out:
1423 	trace_xs_tcp_data_ready(xprt, read, total);
1424 	read_unlock_bh(&sk->sk_callback_lock);
1425 }
1426 
1427 /**
1428  * xs_tcp_state_change - callback to handle TCP socket state changes
1429  * @sk: socket whose state has changed
1430  *
1431  */
1432 static void xs_tcp_state_change(struct sock *sk)
1433 {
1434 	struct rpc_xprt *xprt;
1435 
1436 	read_lock_bh(&sk->sk_callback_lock);
1437 	if (!(xprt = xprt_from_sock(sk)))
1438 		goto out;
1439 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1440 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1441 			sk->sk_state, xprt_connected(xprt),
1442 			sock_flag(sk, SOCK_DEAD),
1443 			sock_flag(sk, SOCK_ZAPPED),
1444 			sk->sk_shutdown);
1445 
1446 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1447 	switch (sk->sk_state) {
1448 	case TCP_ESTABLISHED:
1449 		spin_lock(&xprt->transport_lock);
1450 		if (!xprt_test_and_set_connected(xprt)) {
1451 			struct sock_xprt *transport = container_of(xprt,
1452 					struct sock_xprt, xprt);
1453 
1454 			/* Reset TCP record info */
1455 			transport->tcp_offset = 0;
1456 			transport->tcp_reclen = 0;
1457 			transport->tcp_copied = 0;
1458 			transport->tcp_flags =
1459 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1460 			xprt->connect_cookie++;
1461 
1462 			xprt_wake_pending_tasks(xprt, -EAGAIN);
1463 		}
1464 		spin_unlock(&xprt->transport_lock);
1465 		break;
1466 	case TCP_FIN_WAIT1:
1467 		/* The client initiated a shutdown of the socket */
1468 		xprt->connect_cookie++;
1469 		xprt->reestablish_timeout = 0;
1470 		set_bit(XPRT_CLOSING, &xprt->state);
1471 		smp_mb__before_atomic();
1472 		clear_bit(XPRT_CONNECTED, &xprt->state);
1473 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1474 		smp_mb__after_atomic();
1475 		break;
1476 	case TCP_CLOSE_WAIT:
1477 		/* The server initiated a shutdown of the socket */
1478 		xprt->connect_cookie++;
1479 		clear_bit(XPRT_CONNECTED, &xprt->state);
1480 		xs_tcp_force_close(xprt);
1481 	case TCP_CLOSING:
1482 		/*
1483 		 * If the server closed down the connection, make sure that
1484 		 * we back off before reconnecting
1485 		 */
1486 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1487 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1488 		break;
1489 	case TCP_LAST_ACK:
1490 		set_bit(XPRT_CLOSING, &xprt->state);
1491 		smp_mb__before_atomic();
1492 		clear_bit(XPRT_CONNECTED, &xprt->state);
1493 		smp_mb__after_atomic();
1494 		break;
1495 	case TCP_CLOSE:
1496 		xs_sock_mark_closed(xprt);
1497 	}
1498  out:
1499 	read_unlock_bh(&sk->sk_callback_lock);
1500 }
1501 
1502 static void xs_write_space(struct sock *sk)
1503 {
1504 	struct socket *sock;
1505 	struct rpc_xprt *xprt;
1506 
1507 	if (unlikely(!(sock = sk->sk_socket)))
1508 		return;
1509 	clear_bit(SOCK_NOSPACE, &sock->flags);
1510 
1511 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1512 		return;
1513 	if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1514 		return;
1515 
1516 	xprt_write_space(xprt);
1517 }
1518 
1519 /**
1520  * xs_udp_write_space - callback invoked when socket buffer space
1521  *                             becomes available
1522  * @sk: socket whose state has changed
1523  *
1524  * Called when more output buffer space is available for this socket.
1525  * We try not to wake our writers until they can make "significant"
1526  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1527  * with a bunch of small requests.
1528  */
1529 static void xs_udp_write_space(struct sock *sk)
1530 {
1531 	read_lock_bh(&sk->sk_callback_lock);
1532 
1533 	/* from net/core/sock.c:sock_def_write_space */
1534 	if (sock_writeable(sk))
1535 		xs_write_space(sk);
1536 
1537 	read_unlock_bh(&sk->sk_callback_lock);
1538 }
1539 
1540 /**
1541  * xs_tcp_write_space - callback invoked when socket buffer space
1542  *                             becomes available
1543  * @sk: socket whose state has changed
1544  *
1545  * Called when more output buffer space is available for this socket.
1546  * We try not to wake our writers until they can make "significant"
1547  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1548  * with a bunch of small requests.
1549  */
1550 static void xs_tcp_write_space(struct sock *sk)
1551 {
1552 	read_lock_bh(&sk->sk_callback_lock);
1553 
1554 	/* from net/core/stream.c:sk_stream_write_space */
1555 	if (sk_stream_is_writeable(sk))
1556 		xs_write_space(sk);
1557 
1558 	read_unlock_bh(&sk->sk_callback_lock);
1559 }
1560 
1561 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1562 {
1563 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1564 	struct sock *sk = transport->inet;
1565 
1566 	if (transport->rcvsize) {
1567 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1568 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1569 	}
1570 	if (transport->sndsize) {
1571 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1572 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1573 		sk->sk_write_space(sk);
1574 	}
1575 }
1576 
1577 /**
1578  * xs_udp_set_buffer_size - set send and receive limits
1579  * @xprt: generic transport
1580  * @sndsize: requested size of send buffer, in bytes
1581  * @rcvsize: requested size of receive buffer, in bytes
1582  *
1583  * Set socket send and receive buffer size limits.
1584  */
1585 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1586 {
1587 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1588 
1589 	transport->sndsize = 0;
1590 	if (sndsize)
1591 		transport->sndsize = sndsize + 1024;
1592 	transport->rcvsize = 0;
1593 	if (rcvsize)
1594 		transport->rcvsize = rcvsize + 1024;
1595 
1596 	xs_udp_do_set_buffer_size(xprt);
1597 }
1598 
1599 /**
1600  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1601  * @task: task that timed out
1602  *
1603  * Adjust the congestion window after a retransmit timeout has occurred.
1604  */
1605 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1606 {
1607 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1608 }
1609 
1610 static unsigned short xs_get_random_port(void)
1611 {
1612 	unsigned short range = xprt_max_resvport - xprt_min_resvport;
1613 	unsigned short rand = (unsigned short) prandom_u32() % range;
1614 	return rand + xprt_min_resvport;
1615 }
1616 
1617 /**
1618  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1619  * @sock: socket
1620  *
1621  * Note that this function has to be called on all sockets that share the
1622  * same port, and it must be called before binding.
1623  */
1624 static void xs_sock_set_reuseport(struct socket *sock)
1625 {
1626 	int opt = 1;
1627 
1628 	kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1629 			(char *)&opt, sizeof(opt));
1630 }
1631 
1632 static unsigned short xs_sock_getport(struct socket *sock)
1633 {
1634 	struct sockaddr_storage buf;
1635 	int buflen;
1636 	unsigned short port = 0;
1637 
1638 	if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1639 		goto out;
1640 	switch (buf.ss_family) {
1641 	case AF_INET6:
1642 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1643 		break;
1644 	case AF_INET:
1645 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1646 	}
1647 out:
1648 	return port;
1649 }
1650 
1651 /**
1652  * xs_set_port - reset the port number in the remote endpoint address
1653  * @xprt: generic transport
1654  * @port: new port number
1655  *
1656  */
1657 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1658 {
1659 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1660 
1661 	rpc_set_port(xs_addr(xprt), port);
1662 	xs_update_peer_port(xprt);
1663 }
1664 
1665 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1666 {
1667 	if (transport->srcport == 0)
1668 		transport->srcport = xs_sock_getport(sock);
1669 }
1670 
1671 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1672 {
1673 	unsigned short port = transport->srcport;
1674 
1675 	if (port == 0 && transport->xprt.resvport)
1676 		port = xs_get_random_port();
1677 	return port;
1678 }
1679 
1680 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1681 {
1682 	if (transport->srcport != 0)
1683 		transport->srcport = 0;
1684 	if (!transport->xprt.resvport)
1685 		return 0;
1686 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1687 		return xprt_max_resvport;
1688 	return --port;
1689 }
1690 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1691 {
1692 	struct sockaddr_storage myaddr;
1693 	int err, nloop = 0;
1694 	unsigned short port = xs_get_srcport(transport);
1695 	unsigned short last;
1696 
1697 	/*
1698 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1699 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1700 	 * port selection happen implicitly when the socket is used
1701 	 * (for example at connect time).
1702 	 *
1703 	 * This ensures that we can continue to establish TCP
1704 	 * connections even when all local ephemeral ports are already
1705 	 * a part of some TCP connection.  This makes no difference
1706 	 * for UDP sockets, but also doens't harm them.
1707 	 *
1708 	 * If we're asking for any reserved port (i.e. port == 0 &&
1709 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1710 	 * ensure that port is non-zero and we will bind as needed.
1711 	 */
1712 	if (port == 0)
1713 		return 0;
1714 
1715 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1716 	do {
1717 		rpc_set_port((struct sockaddr *)&myaddr, port);
1718 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1719 				transport->xprt.addrlen);
1720 		if (err == 0) {
1721 			transport->srcport = port;
1722 			break;
1723 		}
1724 		last = port;
1725 		port = xs_next_srcport(transport, port);
1726 		if (port > last)
1727 			nloop++;
1728 	} while (err == -EADDRINUSE && nloop != 2);
1729 
1730 	if (myaddr.ss_family == AF_INET)
1731 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1732 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1733 				port, err ? "failed" : "ok", err);
1734 	else
1735 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1736 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1737 				port, err ? "failed" : "ok", err);
1738 	return err;
1739 }
1740 
1741 /*
1742  * We don't support autobind on AF_LOCAL sockets
1743  */
1744 static void xs_local_rpcbind(struct rpc_task *task)
1745 {
1746 	rcu_read_lock();
1747 	xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1748 	rcu_read_unlock();
1749 }
1750 
1751 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1752 {
1753 }
1754 
1755 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1756 static struct lock_class_key xs_key[2];
1757 static struct lock_class_key xs_slock_key[2];
1758 
1759 static inline void xs_reclassify_socketu(struct socket *sock)
1760 {
1761 	struct sock *sk = sock->sk;
1762 
1763 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1764 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1765 }
1766 
1767 static inline void xs_reclassify_socket4(struct socket *sock)
1768 {
1769 	struct sock *sk = sock->sk;
1770 
1771 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1772 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1773 }
1774 
1775 static inline void xs_reclassify_socket6(struct socket *sock)
1776 {
1777 	struct sock *sk = sock->sk;
1778 
1779 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1780 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1781 }
1782 
1783 static inline void xs_reclassify_socket(int family, struct socket *sock)
1784 {
1785 	WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1786 	if (sock_owned_by_user(sock->sk))
1787 		return;
1788 
1789 	switch (family) {
1790 	case AF_LOCAL:
1791 		xs_reclassify_socketu(sock);
1792 		break;
1793 	case AF_INET:
1794 		xs_reclassify_socket4(sock);
1795 		break;
1796 	case AF_INET6:
1797 		xs_reclassify_socket6(sock);
1798 		break;
1799 	}
1800 }
1801 #else
1802 static inline void xs_reclassify_socketu(struct socket *sock)
1803 {
1804 }
1805 
1806 static inline void xs_reclassify_socket4(struct socket *sock)
1807 {
1808 }
1809 
1810 static inline void xs_reclassify_socket6(struct socket *sock)
1811 {
1812 }
1813 
1814 static inline void xs_reclassify_socket(int family, struct socket *sock)
1815 {
1816 }
1817 #endif
1818 
1819 static void xs_dummy_setup_socket(struct work_struct *work)
1820 {
1821 }
1822 
1823 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1824 		struct sock_xprt *transport, int family, int type,
1825 		int protocol, bool reuseport)
1826 {
1827 	struct socket *sock;
1828 	int err;
1829 
1830 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1831 	if (err < 0) {
1832 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1833 				protocol, -err);
1834 		goto out;
1835 	}
1836 	xs_reclassify_socket(family, sock);
1837 
1838 	if (reuseport)
1839 		xs_sock_set_reuseport(sock);
1840 
1841 	err = xs_bind(transport, sock);
1842 	if (err) {
1843 		sock_release(sock);
1844 		goto out;
1845 	}
1846 
1847 	return sock;
1848 out:
1849 	return ERR_PTR(err);
1850 }
1851 
1852 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1853 				      struct socket *sock)
1854 {
1855 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1856 									xprt);
1857 
1858 	if (!transport->inet) {
1859 		struct sock *sk = sock->sk;
1860 
1861 		write_lock_bh(&sk->sk_callback_lock);
1862 
1863 		xs_save_old_callbacks(transport, sk);
1864 
1865 		sk->sk_user_data = xprt;
1866 		sk->sk_data_ready = xs_local_data_ready;
1867 		sk->sk_write_space = xs_udp_write_space;
1868 		sk->sk_error_report = xs_error_report;
1869 		sk->sk_allocation = GFP_ATOMIC;
1870 
1871 		xprt_clear_connected(xprt);
1872 
1873 		/* Reset to new socket */
1874 		transport->sock = sock;
1875 		transport->inet = sk;
1876 
1877 		write_unlock_bh(&sk->sk_callback_lock);
1878 	}
1879 
1880 	/* Tell the socket layer to start connecting... */
1881 	xprt->stat.connect_count++;
1882 	xprt->stat.connect_start = jiffies;
1883 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1884 }
1885 
1886 /**
1887  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1888  * @transport: socket transport to connect
1889  */
1890 static int xs_local_setup_socket(struct sock_xprt *transport)
1891 {
1892 	struct rpc_xprt *xprt = &transport->xprt;
1893 	struct socket *sock;
1894 	int status = -EIO;
1895 
1896 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1897 					SOCK_STREAM, 0, &sock, 1);
1898 	if (status < 0) {
1899 		dprintk("RPC:       can't create AF_LOCAL "
1900 			"transport socket (%d).\n", -status);
1901 		goto out;
1902 	}
1903 	xs_reclassify_socketu(sock);
1904 
1905 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1906 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1907 
1908 	status = xs_local_finish_connecting(xprt, sock);
1909 	trace_rpc_socket_connect(xprt, sock, status);
1910 	switch (status) {
1911 	case 0:
1912 		dprintk("RPC:       xprt %p connected to %s\n",
1913 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1914 		xprt_set_connected(xprt);
1915 	case -ENOBUFS:
1916 		break;
1917 	case -ENOENT:
1918 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1919 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1920 		break;
1921 	case -ECONNREFUSED:
1922 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1923 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1924 		break;
1925 	default:
1926 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1927 				__func__, -status,
1928 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1929 	}
1930 
1931 out:
1932 	xprt_clear_connecting(xprt);
1933 	xprt_wake_pending_tasks(xprt, status);
1934 	return status;
1935 }
1936 
1937 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1938 {
1939 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1940 	int ret;
1941 
1942 	 if (RPC_IS_ASYNC(task)) {
1943 		/*
1944 		 * We want the AF_LOCAL connect to be resolved in the
1945 		 * filesystem namespace of the process making the rpc
1946 		 * call.  Thus we connect synchronously.
1947 		 *
1948 		 * If we want to support asynchronous AF_LOCAL calls,
1949 		 * we'll need to figure out how to pass a namespace to
1950 		 * connect.
1951 		 */
1952 		rpc_exit(task, -ENOTCONN);
1953 		return;
1954 	}
1955 	ret = xs_local_setup_socket(transport);
1956 	if (ret && !RPC_IS_SOFTCONN(task))
1957 		msleep_interruptible(15000);
1958 }
1959 
1960 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1961 /*
1962  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1963  * know that we have exclusive access to the socket), to guard against
1964  * races with xs_reset_transport.
1965  */
1966 static void xs_set_memalloc(struct rpc_xprt *xprt)
1967 {
1968 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1969 			xprt);
1970 
1971 	/*
1972 	 * If there's no sock, then we have nothing to set. The
1973 	 * reconnecting process will get it for us.
1974 	 */
1975 	if (!transport->inet)
1976 		return;
1977 	if (atomic_read(&xprt->swapper))
1978 		sk_set_memalloc(transport->inet);
1979 }
1980 
1981 /**
1982  * xs_enable_swap - Tag this transport as being used for swap.
1983  * @xprt: transport to tag
1984  *
1985  * Take a reference to this transport on behalf of the rpc_clnt, and
1986  * optionally mark it for swapping if it wasn't already.
1987  */
1988 static int
1989 xs_enable_swap(struct rpc_xprt *xprt)
1990 {
1991 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1992 
1993 	if (atomic_inc_return(&xprt->swapper) != 1)
1994 		return 0;
1995 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1996 		return -ERESTARTSYS;
1997 	if (xs->inet)
1998 		sk_set_memalloc(xs->inet);
1999 	xprt_release_xprt(xprt, NULL);
2000 	return 0;
2001 }
2002 
2003 /**
2004  * xs_disable_swap - Untag this transport as being used for swap.
2005  * @xprt: transport to tag
2006  *
2007  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2008  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2009  */
2010 static void
2011 xs_disable_swap(struct rpc_xprt *xprt)
2012 {
2013 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2014 
2015 	if (!atomic_dec_and_test(&xprt->swapper))
2016 		return;
2017 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2018 		return;
2019 	if (xs->inet)
2020 		sk_clear_memalloc(xs->inet);
2021 	xprt_release_xprt(xprt, NULL);
2022 }
2023 #else
2024 static void xs_set_memalloc(struct rpc_xprt *xprt)
2025 {
2026 }
2027 
2028 static int
2029 xs_enable_swap(struct rpc_xprt *xprt)
2030 {
2031 	return -EINVAL;
2032 }
2033 
2034 static void
2035 xs_disable_swap(struct rpc_xprt *xprt)
2036 {
2037 }
2038 #endif
2039 
2040 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2041 {
2042 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2043 
2044 	if (!transport->inet) {
2045 		struct sock *sk = sock->sk;
2046 
2047 		write_lock_bh(&sk->sk_callback_lock);
2048 
2049 		xs_save_old_callbacks(transport, sk);
2050 
2051 		sk->sk_user_data = xprt;
2052 		sk->sk_data_ready = xs_udp_data_ready;
2053 		sk->sk_write_space = xs_udp_write_space;
2054 		sk->sk_allocation = GFP_ATOMIC;
2055 
2056 		xprt_set_connected(xprt);
2057 
2058 		/* Reset to new socket */
2059 		transport->sock = sock;
2060 		transport->inet = sk;
2061 
2062 		xs_set_memalloc(xprt);
2063 
2064 		write_unlock_bh(&sk->sk_callback_lock);
2065 	}
2066 	xs_udp_do_set_buffer_size(xprt);
2067 }
2068 
2069 static void xs_udp_setup_socket(struct work_struct *work)
2070 {
2071 	struct sock_xprt *transport =
2072 		container_of(work, struct sock_xprt, connect_worker.work);
2073 	struct rpc_xprt *xprt = &transport->xprt;
2074 	struct socket *sock = transport->sock;
2075 	int status = -EIO;
2076 
2077 	sock = xs_create_sock(xprt, transport,
2078 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2079 			IPPROTO_UDP, false);
2080 	if (IS_ERR(sock))
2081 		goto out;
2082 
2083 	dprintk("RPC:       worker connecting xprt %p via %s to "
2084 				"%s (port %s)\n", xprt,
2085 			xprt->address_strings[RPC_DISPLAY_PROTO],
2086 			xprt->address_strings[RPC_DISPLAY_ADDR],
2087 			xprt->address_strings[RPC_DISPLAY_PORT]);
2088 
2089 	xs_udp_finish_connecting(xprt, sock);
2090 	trace_rpc_socket_connect(xprt, sock, 0);
2091 	status = 0;
2092 out:
2093 	xprt_unlock_connect(xprt, transport);
2094 	xprt_clear_connecting(xprt);
2095 	xprt_wake_pending_tasks(xprt, status);
2096 }
2097 
2098 /**
2099  * xs_tcp_shutdown - gracefully shut down a TCP socket
2100  * @xprt: transport
2101  *
2102  * Initiates a graceful shutdown of the TCP socket by calling the
2103  * equivalent of shutdown(SHUT_RDWR);
2104  */
2105 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2106 {
2107 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2108 	struct socket *sock = transport->sock;
2109 
2110 	if (sock == NULL)
2111 		return;
2112 	if (xprt_connected(xprt)) {
2113 		kernel_sock_shutdown(sock, SHUT_RDWR);
2114 		trace_rpc_socket_shutdown(xprt, sock);
2115 	} else
2116 		xs_reset_transport(transport);
2117 }
2118 
2119 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2120 {
2121 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2122 	int ret = -ENOTCONN;
2123 
2124 	if (!transport->inet) {
2125 		struct sock *sk = sock->sk;
2126 		unsigned int keepidle = xprt->timeout->to_initval / HZ;
2127 		unsigned int keepcnt = xprt->timeout->to_retries + 1;
2128 		unsigned int opt_on = 1;
2129 		unsigned int timeo;
2130 
2131 		/* TCP Keepalive options */
2132 		kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2133 				(char *)&opt_on, sizeof(opt_on));
2134 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2135 				(char *)&keepidle, sizeof(keepidle));
2136 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2137 				(char *)&keepidle, sizeof(keepidle));
2138 		kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2139 				(char *)&keepcnt, sizeof(keepcnt));
2140 
2141 		/* TCP user timeout (see RFC5482) */
2142 		timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2143 			(xprt->timeout->to_retries + 1);
2144 		kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2145 				(char *)&timeo, sizeof(timeo));
2146 
2147 		write_lock_bh(&sk->sk_callback_lock);
2148 
2149 		xs_save_old_callbacks(transport, sk);
2150 
2151 		sk->sk_user_data = xprt;
2152 		sk->sk_data_ready = xs_tcp_data_ready;
2153 		sk->sk_state_change = xs_tcp_state_change;
2154 		sk->sk_write_space = xs_tcp_write_space;
2155 		sk->sk_error_report = xs_error_report;
2156 		sk->sk_allocation = GFP_ATOMIC;
2157 
2158 		/* socket options */
2159 		sock_reset_flag(sk, SOCK_LINGER);
2160 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2161 
2162 		xprt_clear_connected(xprt);
2163 
2164 		/* Reset to new socket */
2165 		transport->sock = sock;
2166 		transport->inet = sk;
2167 
2168 		write_unlock_bh(&sk->sk_callback_lock);
2169 	}
2170 
2171 	if (!xprt_bound(xprt))
2172 		goto out;
2173 
2174 	xs_set_memalloc(xprt);
2175 
2176 	/* Tell the socket layer to start connecting... */
2177 	xprt->stat.connect_count++;
2178 	xprt->stat.connect_start = jiffies;
2179 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2180 	switch (ret) {
2181 	case 0:
2182 		xs_set_srcport(transport, sock);
2183 	case -EINPROGRESS:
2184 		/* SYN_SENT! */
2185 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2186 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2187 	}
2188 out:
2189 	return ret;
2190 }
2191 
2192 /**
2193  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2194  *
2195  * Invoked by a work queue tasklet.
2196  */
2197 static void xs_tcp_setup_socket(struct work_struct *work)
2198 {
2199 	struct sock_xprt *transport =
2200 		container_of(work, struct sock_xprt, connect_worker.work);
2201 	struct socket *sock = transport->sock;
2202 	struct rpc_xprt *xprt = &transport->xprt;
2203 	int status = -EIO;
2204 
2205 	if (!sock) {
2206 		sock = xs_create_sock(xprt, transport,
2207 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2208 				IPPROTO_TCP, true);
2209 		if (IS_ERR(sock)) {
2210 			status = PTR_ERR(sock);
2211 			goto out;
2212 		}
2213 	}
2214 
2215 	dprintk("RPC:       worker connecting xprt %p via %s to "
2216 				"%s (port %s)\n", xprt,
2217 			xprt->address_strings[RPC_DISPLAY_PROTO],
2218 			xprt->address_strings[RPC_DISPLAY_ADDR],
2219 			xprt->address_strings[RPC_DISPLAY_PORT]);
2220 
2221 	status = xs_tcp_finish_connecting(xprt, sock);
2222 	trace_rpc_socket_connect(xprt, sock, status);
2223 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2224 			xprt, -status, xprt_connected(xprt),
2225 			sock->sk->sk_state);
2226 	switch (status) {
2227 	default:
2228 		printk("%s: connect returned unhandled error %d\n",
2229 			__func__, status);
2230 	case -EADDRNOTAVAIL:
2231 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2232 		 * and retry
2233 		 */
2234 		xs_tcp_force_close(xprt);
2235 		break;
2236 	case 0:
2237 	case -EINPROGRESS:
2238 	case -EALREADY:
2239 		xprt_unlock_connect(xprt, transport);
2240 		xprt_clear_connecting(xprt);
2241 		return;
2242 	case -EINVAL:
2243 		/* Happens, for instance, if the user specified a link
2244 		 * local IPv6 address without a scope-id.
2245 		 */
2246 	case -ECONNREFUSED:
2247 	case -ECONNRESET:
2248 	case -ENETUNREACH:
2249 	case -EADDRINUSE:
2250 	case -ENOBUFS:
2251 		/* retry with existing socket, after a delay */
2252 		xs_tcp_force_close(xprt);
2253 		goto out;
2254 	}
2255 	status = -EAGAIN;
2256 out:
2257 	xprt_unlock_connect(xprt, transport);
2258 	xprt_clear_connecting(xprt);
2259 	xprt_wake_pending_tasks(xprt, status);
2260 }
2261 
2262 /**
2263  * xs_connect - connect a socket to a remote endpoint
2264  * @xprt: pointer to transport structure
2265  * @task: address of RPC task that manages state of connect request
2266  *
2267  * TCP: If the remote end dropped the connection, delay reconnecting.
2268  *
2269  * UDP socket connects are synchronous, but we use a work queue anyway
2270  * to guarantee that even unprivileged user processes can set up a
2271  * socket on a privileged port.
2272  *
2273  * If a UDP socket connect fails, the delay behavior here prevents
2274  * retry floods (hard mounts).
2275  */
2276 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2277 {
2278 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2279 
2280 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2281 
2282 	/* Start by resetting any existing state */
2283 	xs_reset_transport(transport);
2284 
2285 	if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2286 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2287 				"seconds\n",
2288 				xprt, xprt->reestablish_timeout / HZ);
2289 		queue_delayed_work(rpciod_workqueue,
2290 				   &transport->connect_worker,
2291 				   xprt->reestablish_timeout);
2292 		xprt->reestablish_timeout <<= 1;
2293 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2294 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2295 		if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2296 			xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2297 	} else {
2298 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2299 		queue_delayed_work(rpciod_workqueue,
2300 				   &transport->connect_worker, 0);
2301 	}
2302 }
2303 
2304 /**
2305  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2306  * @xprt: rpc_xprt struct containing statistics
2307  * @seq: output file
2308  *
2309  */
2310 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2311 {
2312 	long idle_time = 0;
2313 
2314 	if (xprt_connected(xprt))
2315 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2316 
2317 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2318 			"%llu %llu %lu %llu %llu\n",
2319 			xprt->stat.bind_count,
2320 			xprt->stat.connect_count,
2321 			xprt->stat.connect_time,
2322 			idle_time,
2323 			xprt->stat.sends,
2324 			xprt->stat.recvs,
2325 			xprt->stat.bad_xids,
2326 			xprt->stat.req_u,
2327 			xprt->stat.bklog_u,
2328 			xprt->stat.max_slots,
2329 			xprt->stat.sending_u,
2330 			xprt->stat.pending_u);
2331 }
2332 
2333 /**
2334  * xs_udp_print_stats - display UDP socket-specifc stats
2335  * @xprt: rpc_xprt struct containing statistics
2336  * @seq: output file
2337  *
2338  */
2339 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2340 {
2341 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2342 
2343 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2344 			"%lu %llu %llu\n",
2345 			transport->srcport,
2346 			xprt->stat.bind_count,
2347 			xprt->stat.sends,
2348 			xprt->stat.recvs,
2349 			xprt->stat.bad_xids,
2350 			xprt->stat.req_u,
2351 			xprt->stat.bklog_u,
2352 			xprt->stat.max_slots,
2353 			xprt->stat.sending_u,
2354 			xprt->stat.pending_u);
2355 }
2356 
2357 /**
2358  * xs_tcp_print_stats - display TCP socket-specifc stats
2359  * @xprt: rpc_xprt struct containing statistics
2360  * @seq: output file
2361  *
2362  */
2363 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2364 {
2365 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2366 	long idle_time = 0;
2367 
2368 	if (xprt_connected(xprt))
2369 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2370 
2371 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2372 			"%llu %llu %lu %llu %llu\n",
2373 			transport->srcport,
2374 			xprt->stat.bind_count,
2375 			xprt->stat.connect_count,
2376 			xprt->stat.connect_time,
2377 			idle_time,
2378 			xprt->stat.sends,
2379 			xprt->stat.recvs,
2380 			xprt->stat.bad_xids,
2381 			xprt->stat.req_u,
2382 			xprt->stat.bklog_u,
2383 			xprt->stat.max_slots,
2384 			xprt->stat.sending_u,
2385 			xprt->stat.pending_u);
2386 }
2387 
2388 /*
2389  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2390  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2391  * to use the server side send routines.
2392  */
2393 static void *bc_malloc(struct rpc_task *task, size_t size)
2394 {
2395 	struct page *page;
2396 	struct rpc_buffer *buf;
2397 
2398 	WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2399 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2400 		return NULL;
2401 
2402 	page = alloc_page(GFP_KERNEL);
2403 	if (!page)
2404 		return NULL;
2405 
2406 	buf = page_address(page);
2407 	buf->len = PAGE_SIZE;
2408 
2409 	return buf->data;
2410 }
2411 
2412 /*
2413  * Free the space allocated in the bc_alloc routine
2414  */
2415 static void bc_free(void *buffer)
2416 {
2417 	struct rpc_buffer *buf;
2418 
2419 	if (!buffer)
2420 		return;
2421 
2422 	buf = container_of(buffer, struct rpc_buffer, data);
2423 	free_page((unsigned long)buf);
2424 }
2425 
2426 /*
2427  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2428  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2429  */
2430 static int bc_sendto(struct rpc_rqst *req)
2431 {
2432 	int len;
2433 	struct xdr_buf *xbufp = &req->rq_snd_buf;
2434 	struct rpc_xprt *xprt = req->rq_xprt;
2435 	struct sock_xprt *transport =
2436 				container_of(xprt, struct sock_xprt, xprt);
2437 	struct socket *sock = transport->sock;
2438 	unsigned long headoff;
2439 	unsigned long tailoff;
2440 
2441 	xs_encode_stream_record_marker(xbufp);
2442 
2443 	tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2444 	headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2445 	len = svc_send_common(sock, xbufp,
2446 			      virt_to_page(xbufp->head[0].iov_base), headoff,
2447 			      xbufp->tail[0].iov_base, tailoff);
2448 
2449 	if (len != xbufp->len) {
2450 		printk(KERN_NOTICE "Error sending entire callback!\n");
2451 		len = -EAGAIN;
2452 	}
2453 
2454 	return len;
2455 }
2456 
2457 /*
2458  * The send routine. Borrows from svc_send
2459  */
2460 static int bc_send_request(struct rpc_task *task)
2461 {
2462 	struct rpc_rqst *req = task->tk_rqstp;
2463 	struct svc_xprt	*xprt;
2464 	u32                     len;
2465 
2466 	dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2467 	/*
2468 	 * Get the server socket associated with this callback xprt
2469 	 */
2470 	xprt = req->rq_xprt->bc_xprt;
2471 
2472 	/*
2473 	 * Grab the mutex to serialize data as the connection is shared
2474 	 * with the fore channel
2475 	 */
2476 	if (!mutex_trylock(&xprt->xpt_mutex)) {
2477 		rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2478 		if (!mutex_trylock(&xprt->xpt_mutex))
2479 			return -EAGAIN;
2480 		rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2481 	}
2482 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2483 		len = -ENOTCONN;
2484 	else
2485 		len = bc_sendto(req);
2486 	mutex_unlock(&xprt->xpt_mutex);
2487 
2488 	if (len > 0)
2489 		len = 0;
2490 
2491 	return len;
2492 }
2493 
2494 /*
2495  * The close routine. Since this is client initiated, we do nothing
2496  */
2497 
2498 static void bc_close(struct rpc_xprt *xprt)
2499 {
2500 }
2501 
2502 /*
2503  * The xprt destroy routine. Again, because this connection is client
2504  * initiated, we do nothing
2505  */
2506 
2507 static void bc_destroy(struct rpc_xprt *xprt)
2508 {
2509 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2510 
2511 	xs_xprt_free(xprt);
2512 	module_put(THIS_MODULE);
2513 }
2514 
2515 static struct rpc_xprt_ops xs_local_ops = {
2516 	.reserve_xprt		= xprt_reserve_xprt,
2517 	.release_xprt		= xs_tcp_release_xprt,
2518 	.alloc_slot		= xprt_alloc_slot,
2519 	.rpcbind		= xs_local_rpcbind,
2520 	.set_port		= xs_local_set_port,
2521 	.connect		= xs_local_connect,
2522 	.buf_alloc		= rpc_malloc,
2523 	.buf_free		= rpc_free,
2524 	.send_request		= xs_local_send_request,
2525 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2526 	.close			= xs_close,
2527 	.destroy		= xs_destroy,
2528 	.print_stats		= xs_local_print_stats,
2529 	.enable_swap		= xs_enable_swap,
2530 	.disable_swap		= xs_disable_swap,
2531 };
2532 
2533 static struct rpc_xprt_ops xs_udp_ops = {
2534 	.set_buffer_size	= xs_udp_set_buffer_size,
2535 	.reserve_xprt		= xprt_reserve_xprt_cong,
2536 	.release_xprt		= xprt_release_xprt_cong,
2537 	.alloc_slot		= xprt_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_udp_send_request,
2544 	.set_retrans_timeout	= xprt_set_retrans_timeout_rtt,
2545 	.timer			= xs_udp_timer,
2546 	.release_request	= xprt_release_rqst_cong,
2547 	.close			= xs_close,
2548 	.destroy		= xs_destroy,
2549 	.print_stats		= xs_udp_print_stats,
2550 	.enable_swap		= xs_enable_swap,
2551 	.disable_swap		= xs_disable_swap,
2552 	.inject_disconnect	= xs_inject_disconnect,
2553 };
2554 
2555 static struct rpc_xprt_ops xs_tcp_ops = {
2556 	.reserve_xprt		= xprt_reserve_xprt,
2557 	.release_xprt		= xs_tcp_release_xprt,
2558 	.alloc_slot		= xprt_lock_and_alloc_slot,
2559 	.rpcbind		= rpcb_getport_async,
2560 	.set_port		= xs_set_port,
2561 	.connect		= xs_connect,
2562 	.buf_alloc		= rpc_malloc,
2563 	.buf_free		= rpc_free,
2564 	.send_request		= xs_tcp_send_request,
2565 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2566 	.close			= xs_tcp_shutdown,
2567 	.destroy		= xs_destroy,
2568 	.print_stats		= xs_tcp_print_stats,
2569 	.enable_swap		= xs_enable_swap,
2570 	.disable_swap		= xs_disable_swap,
2571 	.inject_disconnect	= xs_inject_disconnect,
2572 };
2573 
2574 /*
2575  * The rpc_xprt_ops for the server backchannel
2576  */
2577 
2578 static struct rpc_xprt_ops bc_tcp_ops = {
2579 	.reserve_xprt		= xprt_reserve_xprt,
2580 	.release_xprt		= xprt_release_xprt,
2581 	.alloc_slot		= xprt_alloc_slot,
2582 	.buf_alloc		= bc_malloc,
2583 	.buf_free		= bc_free,
2584 	.send_request		= bc_send_request,
2585 	.set_retrans_timeout	= xprt_set_retrans_timeout_def,
2586 	.close			= bc_close,
2587 	.destroy		= bc_destroy,
2588 	.print_stats		= xs_tcp_print_stats,
2589 	.enable_swap		= xs_enable_swap,
2590 	.disable_swap		= xs_disable_swap,
2591 	.inject_disconnect	= xs_inject_disconnect,
2592 };
2593 
2594 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2595 {
2596 	static const struct sockaddr_in sin = {
2597 		.sin_family		= AF_INET,
2598 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2599 	};
2600 	static const struct sockaddr_in6 sin6 = {
2601 		.sin6_family		= AF_INET6,
2602 		.sin6_addr		= IN6ADDR_ANY_INIT,
2603 	};
2604 
2605 	switch (family) {
2606 	case AF_LOCAL:
2607 		break;
2608 	case AF_INET:
2609 		memcpy(sap, &sin, sizeof(sin));
2610 		break;
2611 	case AF_INET6:
2612 		memcpy(sap, &sin6, sizeof(sin6));
2613 		break;
2614 	default:
2615 		dprintk("RPC:       %s: Bad address family\n", __func__);
2616 		return -EAFNOSUPPORT;
2617 	}
2618 	return 0;
2619 }
2620 
2621 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2622 				      unsigned int slot_table_size,
2623 				      unsigned int max_slot_table_size)
2624 {
2625 	struct rpc_xprt *xprt;
2626 	struct sock_xprt *new;
2627 
2628 	if (args->addrlen > sizeof(xprt->addr)) {
2629 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2630 		return ERR_PTR(-EBADF);
2631 	}
2632 
2633 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2634 			max_slot_table_size);
2635 	if (xprt == NULL) {
2636 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2637 				"rpc_xprt\n");
2638 		return ERR_PTR(-ENOMEM);
2639 	}
2640 
2641 	new = container_of(xprt, struct sock_xprt, xprt);
2642 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2643 	xprt->addrlen = args->addrlen;
2644 	if (args->srcaddr)
2645 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2646 	else {
2647 		int err;
2648 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2649 					(struct sockaddr *)&new->srcaddr);
2650 		if (err != 0) {
2651 			xprt_free(xprt);
2652 			return ERR_PTR(err);
2653 		}
2654 	}
2655 
2656 	return xprt;
2657 }
2658 
2659 static const struct rpc_timeout xs_local_default_timeout = {
2660 	.to_initval = 10 * HZ,
2661 	.to_maxval = 10 * HZ,
2662 	.to_retries = 2,
2663 };
2664 
2665 /**
2666  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2667  * @args: rpc transport creation arguments
2668  *
2669  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2670  */
2671 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2672 {
2673 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2674 	struct sock_xprt *transport;
2675 	struct rpc_xprt *xprt;
2676 	struct rpc_xprt *ret;
2677 
2678 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2679 			xprt_max_tcp_slot_table_entries);
2680 	if (IS_ERR(xprt))
2681 		return xprt;
2682 	transport = container_of(xprt, struct sock_xprt, xprt);
2683 
2684 	xprt->prot = 0;
2685 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2686 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2687 
2688 	xprt->bind_timeout = XS_BIND_TO;
2689 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2690 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2691 
2692 	xprt->ops = &xs_local_ops;
2693 	xprt->timeout = &xs_local_default_timeout;
2694 
2695 	INIT_DELAYED_WORK(&transport->connect_worker,
2696 			xs_dummy_setup_socket);
2697 
2698 	switch (sun->sun_family) {
2699 	case AF_LOCAL:
2700 		if (sun->sun_path[0] != '/') {
2701 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2702 					sun->sun_path);
2703 			ret = ERR_PTR(-EINVAL);
2704 			goto out_err;
2705 		}
2706 		xprt_set_bound(xprt);
2707 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2708 		ret = ERR_PTR(xs_local_setup_socket(transport));
2709 		if (ret)
2710 			goto out_err;
2711 		break;
2712 	default:
2713 		ret = ERR_PTR(-EAFNOSUPPORT);
2714 		goto out_err;
2715 	}
2716 
2717 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2718 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2719 
2720 	if (try_module_get(THIS_MODULE))
2721 		return xprt;
2722 	ret = ERR_PTR(-EINVAL);
2723 out_err:
2724 	xs_xprt_free(xprt);
2725 	return ret;
2726 }
2727 
2728 static const struct rpc_timeout xs_udp_default_timeout = {
2729 	.to_initval = 5 * HZ,
2730 	.to_maxval = 30 * HZ,
2731 	.to_increment = 5 * HZ,
2732 	.to_retries = 5,
2733 };
2734 
2735 /**
2736  * xs_setup_udp - Set up transport to use a UDP socket
2737  * @args: rpc transport creation arguments
2738  *
2739  */
2740 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2741 {
2742 	struct sockaddr *addr = args->dstaddr;
2743 	struct rpc_xprt *xprt;
2744 	struct sock_xprt *transport;
2745 	struct rpc_xprt *ret;
2746 
2747 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2748 			xprt_udp_slot_table_entries);
2749 	if (IS_ERR(xprt))
2750 		return xprt;
2751 	transport = container_of(xprt, struct sock_xprt, xprt);
2752 
2753 	xprt->prot = IPPROTO_UDP;
2754 	xprt->tsh_size = 0;
2755 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2756 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2757 
2758 	xprt->bind_timeout = XS_BIND_TO;
2759 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2760 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2761 
2762 	xprt->ops = &xs_udp_ops;
2763 
2764 	xprt->timeout = &xs_udp_default_timeout;
2765 
2766 	switch (addr->sa_family) {
2767 	case AF_INET:
2768 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2769 			xprt_set_bound(xprt);
2770 
2771 		INIT_DELAYED_WORK(&transport->connect_worker,
2772 					xs_udp_setup_socket);
2773 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2774 		break;
2775 	case AF_INET6:
2776 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2777 			xprt_set_bound(xprt);
2778 
2779 		INIT_DELAYED_WORK(&transport->connect_worker,
2780 					xs_udp_setup_socket);
2781 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2782 		break;
2783 	default:
2784 		ret = ERR_PTR(-EAFNOSUPPORT);
2785 		goto out_err;
2786 	}
2787 
2788 	if (xprt_bound(xprt))
2789 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2790 				xprt->address_strings[RPC_DISPLAY_ADDR],
2791 				xprt->address_strings[RPC_DISPLAY_PORT],
2792 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2793 	else
2794 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2795 				xprt->address_strings[RPC_DISPLAY_ADDR],
2796 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2797 
2798 	if (try_module_get(THIS_MODULE))
2799 		return xprt;
2800 	ret = ERR_PTR(-EINVAL);
2801 out_err:
2802 	xs_xprt_free(xprt);
2803 	return ret;
2804 }
2805 
2806 static const struct rpc_timeout xs_tcp_default_timeout = {
2807 	.to_initval = 60 * HZ,
2808 	.to_maxval = 60 * HZ,
2809 	.to_retries = 2,
2810 };
2811 
2812 /**
2813  * xs_setup_tcp - Set up transport to use a TCP socket
2814  * @args: rpc transport creation arguments
2815  *
2816  */
2817 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2818 {
2819 	struct sockaddr *addr = args->dstaddr;
2820 	struct rpc_xprt *xprt;
2821 	struct sock_xprt *transport;
2822 	struct rpc_xprt *ret;
2823 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2824 
2825 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2826 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2827 
2828 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2829 			max_slot_table_size);
2830 	if (IS_ERR(xprt))
2831 		return xprt;
2832 	transport = container_of(xprt, struct sock_xprt, xprt);
2833 
2834 	xprt->prot = IPPROTO_TCP;
2835 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2836 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2837 
2838 	xprt->bind_timeout = XS_BIND_TO;
2839 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2840 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2841 
2842 	xprt->ops = &xs_tcp_ops;
2843 	xprt->timeout = &xs_tcp_default_timeout;
2844 
2845 	switch (addr->sa_family) {
2846 	case AF_INET:
2847 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2848 			xprt_set_bound(xprt);
2849 
2850 		INIT_DELAYED_WORK(&transport->connect_worker,
2851 					xs_tcp_setup_socket);
2852 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2853 		break;
2854 	case AF_INET6:
2855 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2856 			xprt_set_bound(xprt);
2857 
2858 		INIT_DELAYED_WORK(&transport->connect_worker,
2859 					xs_tcp_setup_socket);
2860 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2861 		break;
2862 	default:
2863 		ret = ERR_PTR(-EAFNOSUPPORT);
2864 		goto out_err;
2865 	}
2866 
2867 	if (xprt_bound(xprt))
2868 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2869 				xprt->address_strings[RPC_DISPLAY_ADDR],
2870 				xprt->address_strings[RPC_DISPLAY_PORT],
2871 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2872 	else
2873 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2874 				xprt->address_strings[RPC_DISPLAY_ADDR],
2875 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2876 
2877 	if (try_module_get(THIS_MODULE))
2878 		return xprt;
2879 	ret = ERR_PTR(-EINVAL);
2880 out_err:
2881 	xs_xprt_free(xprt);
2882 	return ret;
2883 }
2884 
2885 /**
2886  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2887  * @args: rpc transport creation arguments
2888  *
2889  */
2890 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2891 {
2892 	struct sockaddr *addr = args->dstaddr;
2893 	struct rpc_xprt *xprt;
2894 	struct sock_xprt *transport;
2895 	struct svc_sock *bc_sock;
2896 	struct rpc_xprt *ret;
2897 
2898 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2899 			xprt_tcp_slot_table_entries);
2900 	if (IS_ERR(xprt))
2901 		return xprt;
2902 	transport = container_of(xprt, struct sock_xprt, xprt);
2903 
2904 	xprt->prot = IPPROTO_TCP;
2905 	xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2906 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2907 	xprt->timeout = &xs_tcp_default_timeout;
2908 
2909 	/* backchannel */
2910 	xprt_set_bound(xprt);
2911 	xprt->bind_timeout = 0;
2912 	xprt->reestablish_timeout = 0;
2913 	xprt->idle_timeout = 0;
2914 
2915 	xprt->ops = &bc_tcp_ops;
2916 
2917 	switch (addr->sa_family) {
2918 	case AF_INET:
2919 		xs_format_peer_addresses(xprt, "tcp",
2920 					 RPCBIND_NETID_TCP);
2921 		break;
2922 	case AF_INET6:
2923 		xs_format_peer_addresses(xprt, "tcp",
2924 				   RPCBIND_NETID_TCP6);
2925 		break;
2926 	default:
2927 		ret = ERR_PTR(-EAFNOSUPPORT);
2928 		goto out_err;
2929 	}
2930 
2931 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2932 			xprt->address_strings[RPC_DISPLAY_ADDR],
2933 			xprt->address_strings[RPC_DISPLAY_PORT],
2934 			xprt->address_strings[RPC_DISPLAY_PROTO]);
2935 
2936 	/*
2937 	 * Once we've associated a backchannel xprt with a connection,
2938 	 * we want to keep it around as long as the connection lasts,
2939 	 * in case we need to start using it for a backchannel again;
2940 	 * this reference won't be dropped until bc_xprt is destroyed.
2941 	 */
2942 	xprt_get(xprt);
2943 	args->bc_xprt->xpt_bc_xprt = xprt;
2944 	xprt->bc_xprt = args->bc_xprt;
2945 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2946 	transport->sock = bc_sock->sk_sock;
2947 	transport->inet = bc_sock->sk_sk;
2948 
2949 	/*
2950 	 * Since we don't want connections for the backchannel, we set
2951 	 * the xprt status to connected
2952 	 */
2953 	xprt_set_connected(xprt);
2954 
2955 	if (try_module_get(THIS_MODULE))
2956 		return xprt;
2957 
2958 	args->bc_xprt->xpt_bc_xprt = NULL;
2959 	xprt_put(xprt);
2960 	ret = ERR_PTR(-EINVAL);
2961 out_err:
2962 	xs_xprt_free(xprt);
2963 	return ret;
2964 }
2965 
2966 static struct xprt_class	xs_local_transport = {
2967 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
2968 	.name		= "named UNIX socket",
2969 	.owner		= THIS_MODULE,
2970 	.ident		= XPRT_TRANSPORT_LOCAL,
2971 	.setup		= xs_setup_local,
2972 };
2973 
2974 static struct xprt_class	xs_udp_transport = {
2975 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
2976 	.name		= "udp",
2977 	.owner		= THIS_MODULE,
2978 	.ident		= XPRT_TRANSPORT_UDP,
2979 	.setup		= xs_setup_udp,
2980 };
2981 
2982 static struct xprt_class	xs_tcp_transport = {
2983 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
2984 	.name		= "tcp",
2985 	.owner		= THIS_MODULE,
2986 	.ident		= XPRT_TRANSPORT_TCP,
2987 	.setup		= xs_setup_tcp,
2988 };
2989 
2990 static struct xprt_class	xs_bc_tcp_transport = {
2991 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2992 	.name		= "tcp NFSv4.1 backchannel",
2993 	.owner		= THIS_MODULE,
2994 	.ident		= XPRT_TRANSPORT_BC_TCP,
2995 	.setup		= xs_setup_bc_tcp,
2996 };
2997 
2998 /**
2999  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3000  *
3001  */
3002 int init_socket_xprt(void)
3003 {
3004 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3005 	if (!sunrpc_table_header)
3006 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3007 #endif
3008 
3009 	xprt_register_transport(&xs_local_transport);
3010 	xprt_register_transport(&xs_udp_transport);
3011 	xprt_register_transport(&xs_tcp_transport);
3012 	xprt_register_transport(&xs_bc_tcp_transport);
3013 
3014 	return 0;
3015 }
3016 
3017 /**
3018  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3019  *
3020  */
3021 void cleanup_socket_xprt(void)
3022 {
3023 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3024 	if (sunrpc_table_header) {
3025 		unregister_sysctl_table(sunrpc_table_header);
3026 		sunrpc_table_header = NULL;
3027 	}
3028 #endif
3029 
3030 	xprt_unregister_transport(&xs_local_transport);
3031 	xprt_unregister_transport(&xs_udp_transport);
3032 	xprt_unregister_transport(&xs_tcp_transport);
3033 	xprt_unregister_transport(&xs_bc_tcp_transport);
3034 }
3035 
3036 static int param_set_uint_minmax(const char *val,
3037 		const struct kernel_param *kp,
3038 		unsigned int min, unsigned int max)
3039 {
3040 	unsigned int num;
3041 	int ret;
3042 
3043 	if (!val)
3044 		return -EINVAL;
3045 	ret = kstrtouint(val, 0, &num);
3046 	if (ret == -EINVAL || num < min || num > max)
3047 		return -EINVAL;
3048 	*((unsigned int *)kp->arg) = num;
3049 	return 0;
3050 }
3051 
3052 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3053 {
3054 	return param_set_uint_minmax(val, kp,
3055 			RPC_MIN_RESVPORT,
3056 			RPC_MAX_RESVPORT);
3057 }
3058 
3059 static const struct kernel_param_ops param_ops_portnr = {
3060 	.set = param_set_portnr,
3061 	.get = param_get_uint,
3062 };
3063 
3064 #define param_check_portnr(name, p) \
3065 	__param_check(name, p, unsigned int);
3066 
3067 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3068 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3069 
3070 static int param_set_slot_table_size(const char *val,
3071 				     const struct kernel_param *kp)
3072 {
3073 	return param_set_uint_minmax(val, kp,
3074 			RPC_MIN_SLOT_TABLE,
3075 			RPC_MAX_SLOT_TABLE);
3076 }
3077 
3078 static const struct kernel_param_ops param_ops_slot_table_size = {
3079 	.set = param_set_slot_table_size,
3080 	.get = param_get_uint,
3081 };
3082 
3083 #define param_check_slot_table_size(name, p) \
3084 	__param_check(name, p, unsigned int);
3085 
3086 static int param_set_max_slot_table_size(const char *val,
3087 				     const struct kernel_param *kp)
3088 {
3089 	return param_set_uint_minmax(val, kp,
3090 			RPC_MIN_SLOT_TABLE,
3091 			RPC_MAX_SLOT_TABLE_LIMIT);
3092 }
3093 
3094 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3095 	.set = param_set_max_slot_table_size,
3096 	.get = param_get_uint,
3097 };
3098 
3099 #define param_check_max_slot_table_size(name, p) \
3100 	__param_check(name, p, unsigned int);
3101 
3102 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3103 		   slot_table_size, 0644);
3104 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3105 		   max_slot_table_size, 0644);
3106 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3107 		   slot_table_size, 0644);
3108 
3109