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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/net/sunrpc/xprtsock.c
4  *
5  * Client-side transport implementation for sockets.
6  *
7  * TCP callback races fixes (C) 1998 Red Hat
8  * TCP send fixes (C) 1998 Red Hat
9  * TCP NFS related read + write fixes
10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
11  *
12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
13  * Fix behaviour when socket buffer is full.
14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
15  *
16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
17  *
18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
19  *   <gilles.quillard@bull.net>
20  */
21 
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/pagemap.h>
28 #include <linux/errno.h>
29 #include <linux/socket.h>
30 #include <linux/in.h>
31 #include <linux/net.h>
32 #include <linux/mm.h>
33 #include <linux/un.h>
34 #include <linux/udp.h>
35 #include <linux/tcp.h>
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/addr.h>
38 #include <linux/sunrpc/sched.h>
39 #include <linux/sunrpc/svcsock.h>
40 #include <linux/sunrpc/xprtsock.h>
41 #include <linux/file.h>
42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
43 #include <linux/sunrpc/bc_xprt.h>
44 #endif
45 
46 #include <net/sock.h>
47 #include <net/checksum.h>
48 #include <net/udp.h>
49 #include <net/tcp.h>
50 #include <linux/bvec.h>
51 #include <linux/highmem.h>
52 #include <linux/uio.h>
53 #include <linux/sched/mm.h>
54 
55 #include <trace/events/sunrpc.h>
56 
57 #include "socklib.h"
58 #include "sunrpc.h"
59 
60 static void xs_close(struct rpc_xprt *xprt);
61 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
62 		struct socket *sock);
63 
64 /*
65  * xprtsock tunables
66  */
67 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
68 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
69 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
70 
71 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
72 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
73 
74 #define XS_TCP_LINGER_TO	(15U * HZ)
75 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
76 
77 /*
78  * We can register our own files under /proc/sys/sunrpc by
79  * calling register_sysctl_table() again.  The files in that
80  * directory become the union of all files registered there.
81  *
82  * We simply need to make sure that we don't collide with
83  * someone else's file names!
84  */
85 
86 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
87 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
88 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
89 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
90 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
91 
92 static struct ctl_table_header *sunrpc_table_header;
93 
94 /*
95  * FIXME: changing the UDP slot table size should also resize the UDP
96  *        socket buffers for existing UDP transports
97  */
98 static struct ctl_table xs_tunables_table[] = {
99 	{
100 		.procname	= "udp_slot_table_entries",
101 		.data		= &xprt_udp_slot_table_entries,
102 		.maxlen		= sizeof(unsigned int),
103 		.mode		= 0644,
104 		.proc_handler	= proc_dointvec_minmax,
105 		.extra1		= &min_slot_table_size,
106 		.extra2		= &max_slot_table_size
107 	},
108 	{
109 		.procname	= "tcp_slot_table_entries",
110 		.data		= &xprt_tcp_slot_table_entries,
111 		.maxlen		= sizeof(unsigned int),
112 		.mode		= 0644,
113 		.proc_handler	= proc_dointvec_minmax,
114 		.extra1		= &min_slot_table_size,
115 		.extra2		= &max_slot_table_size
116 	},
117 	{
118 		.procname	= "tcp_max_slot_table_entries",
119 		.data		= &xprt_max_tcp_slot_table_entries,
120 		.maxlen		= sizeof(unsigned int),
121 		.mode		= 0644,
122 		.proc_handler	= proc_dointvec_minmax,
123 		.extra1		= &min_slot_table_size,
124 		.extra2		= &max_tcp_slot_table_limit
125 	},
126 	{
127 		.procname	= "min_resvport",
128 		.data		= &xprt_min_resvport,
129 		.maxlen		= sizeof(unsigned int),
130 		.mode		= 0644,
131 		.proc_handler	= proc_dointvec_minmax,
132 		.extra1		= &xprt_min_resvport_limit,
133 		.extra2		= &xprt_max_resvport_limit
134 	},
135 	{
136 		.procname	= "max_resvport",
137 		.data		= &xprt_max_resvport,
138 		.maxlen		= sizeof(unsigned int),
139 		.mode		= 0644,
140 		.proc_handler	= proc_dointvec_minmax,
141 		.extra1		= &xprt_min_resvport_limit,
142 		.extra2		= &xprt_max_resvport_limit
143 	},
144 	{
145 		.procname	= "tcp_fin_timeout",
146 		.data		= &xs_tcp_fin_timeout,
147 		.maxlen		= sizeof(xs_tcp_fin_timeout),
148 		.mode		= 0644,
149 		.proc_handler	= proc_dointvec_jiffies,
150 	},
151 	{ },
152 };
153 
154 static struct ctl_table sunrpc_table[] = {
155 	{
156 		.procname	= "sunrpc",
157 		.mode		= 0555,
158 		.child		= xs_tunables_table
159 	},
160 	{ },
161 };
162 
163 /*
164  * Wait duration for a reply from the RPC portmapper.
165  */
166 #define XS_BIND_TO		(60U * HZ)
167 
168 /*
169  * Delay if a UDP socket connect error occurs.  This is most likely some
170  * kind of resource problem on the local host.
171  */
172 #define XS_UDP_REEST_TO		(2U * HZ)
173 
174 /*
175  * The reestablish timeout allows clients to delay for a bit before attempting
176  * to reconnect to a server that just dropped our connection.
177  *
178  * We implement an exponential backoff when trying to reestablish a TCP
179  * transport connection with the server.  Some servers like to drop a TCP
180  * connection when they are overworked, so we start with a short timeout and
181  * increase over time if the server is down or not responding.
182  */
183 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
184 
185 /*
186  * TCP idle timeout; client drops the transport socket if it is idle
187  * for this long.  Note that we also timeout UDP sockets to prevent
188  * holding port numbers when there is no RPC traffic.
189  */
190 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
191 
192 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
193 # undef  RPC_DEBUG_DATA
194 # define RPCDBG_FACILITY	RPCDBG_TRANS
195 #endif
196 
197 #ifdef RPC_DEBUG_DATA
xs_pktdump(char * msg,u32 * packet,unsigned int count)198 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
199 {
200 	u8 *buf = (u8 *) packet;
201 	int j;
202 
203 	dprintk("RPC:       %s\n", msg);
204 	for (j = 0; j < count && j < 128; j += 4) {
205 		if (!(j & 31)) {
206 			if (j)
207 				dprintk("\n");
208 			dprintk("0x%04x ", j);
209 		}
210 		dprintk("%02x%02x%02x%02x ",
211 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
212 	}
213 	dprintk("\n");
214 }
215 #else
xs_pktdump(char * msg,u32 * packet,unsigned int count)216 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
217 {
218 	/* NOP */
219 }
220 #endif
221 
xprt_from_sock(struct sock * sk)222 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
223 {
224 	return (struct rpc_xprt *) sk->sk_user_data;
225 }
226 
xs_addr(struct rpc_xprt * xprt)227 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
228 {
229 	return (struct sockaddr *) &xprt->addr;
230 }
231 
xs_addr_un(struct rpc_xprt * xprt)232 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
233 {
234 	return (struct sockaddr_un *) &xprt->addr;
235 }
236 
xs_addr_in(struct rpc_xprt * xprt)237 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
238 {
239 	return (struct sockaddr_in *) &xprt->addr;
240 }
241 
xs_addr_in6(struct rpc_xprt * xprt)242 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
243 {
244 	return (struct sockaddr_in6 *) &xprt->addr;
245 }
246 
xs_format_common_peer_addresses(struct rpc_xprt * xprt)247 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
248 {
249 	struct sockaddr *sap = xs_addr(xprt);
250 	struct sockaddr_in6 *sin6;
251 	struct sockaddr_in *sin;
252 	struct sockaddr_un *sun;
253 	char buf[128];
254 
255 	switch (sap->sa_family) {
256 	case AF_LOCAL:
257 		sun = xs_addr_un(xprt);
258 		strlcpy(buf, sun->sun_path, sizeof(buf));
259 		xprt->address_strings[RPC_DISPLAY_ADDR] =
260 						kstrdup(buf, GFP_KERNEL);
261 		break;
262 	case AF_INET:
263 		(void)rpc_ntop(sap, buf, sizeof(buf));
264 		xprt->address_strings[RPC_DISPLAY_ADDR] =
265 						kstrdup(buf, GFP_KERNEL);
266 		sin = xs_addr_in(xprt);
267 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
268 		break;
269 	case AF_INET6:
270 		(void)rpc_ntop(sap, buf, sizeof(buf));
271 		xprt->address_strings[RPC_DISPLAY_ADDR] =
272 						kstrdup(buf, GFP_KERNEL);
273 		sin6 = xs_addr_in6(xprt);
274 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
275 		break;
276 	default:
277 		BUG();
278 	}
279 
280 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
281 }
282 
xs_format_common_peer_ports(struct rpc_xprt * xprt)283 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
284 {
285 	struct sockaddr *sap = xs_addr(xprt);
286 	char buf[128];
287 
288 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
289 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
290 
291 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
292 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
293 }
294 
xs_format_peer_addresses(struct rpc_xprt * xprt,const char * protocol,const char * netid)295 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
296 				     const char *protocol,
297 				     const char *netid)
298 {
299 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
300 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
301 	xs_format_common_peer_addresses(xprt);
302 	xs_format_common_peer_ports(xprt);
303 }
304 
xs_update_peer_port(struct rpc_xprt * xprt)305 static void xs_update_peer_port(struct rpc_xprt *xprt)
306 {
307 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
308 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
309 
310 	xs_format_common_peer_ports(xprt);
311 }
312 
xs_free_peer_addresses(struct rpc_xprt * xprt)313 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
314 {
315 	unsigned int i;
316 
317 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
318 		switch (i) {
319 		case RPC_DISPLAY_PROTO:
320 		case RPC_DISPLAY_NETID:
321 			continue;
322 		default:
323 			kfree(xprt->address_strings[i]);
324 		}
325 }
326 
327 static size_t
xs_alloc_sparse_pages(struct xdr_buf * buf,size_t want,gfp_t gfp)328 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
329 {
330 	size_t i,n;
331 
332 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
333 		return want;
334 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
335 	for (i = 0; i < n; i++) {
336 		if (buf->pages[i])
337 			continue;
338 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
339 		if (!buf->pages[i]) {
340 			i *= PAGE_SIZE;
341 			return i > buf->page_base ? i - buf->page_base : 0;
342 		}
343 	}
344 	return want;
345 }
346 
347 static ssize_t
xs_sock_recvmsg(struct socket * sock,struct msghdr * msg,int flags,size_t seek)348 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
349 {
350 	ssize_t ret;
351 	if (seek != 0)
352 		iov_iter_advance(&msg->msg_iter, seek);
353 	ret = sock_recvmsg(sock, msg, flags);
354 	return ret > 0 ? ret + seek : ret;
355 }
356 
357 static ssize_t
xs_read_kvec(struct socket * sock,struct msghdr * msg,int flags,struct kvec * kvec,size_t count,size_t seek)358 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
359 		struct kvec *kvec, size_t count, size_t seek)
360 {
361 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
362 	return xs_sock_recvmsg(sock, msg, flags, seek);
363 }
364 
365 static ssize_t
xs_read_bvec(struct socket * sock,struct msghdr * msg,int flags,struct bio_vec * bvec,unsigned long nr,size_t count,size_t seek)366 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
367 		struct bio_vec *bvec, unsigned long nr, size_t count,
368 		size_t seek)
369 {
370 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
371 	return xs_sock_recvmsg(sock, msg, flags, seek);
372 }
373 
374 static ssize_t
xs_read_discard(struct socket * sock,struct msghdr * msg,int flags,size_t count)375 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
376 		size_t count)
377 {
378 	iov_iter_discard(&msg->msg_iter, READ, count);
379 	return sock_recvmsg(sock, msg, flags);
380 }
381 
382 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
383 static void
xs_flush_bvec(const struct bio_vec * bvec,size_t count,size_t seek)384 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
385 {
386 	struct bvec_iter bi = {
387 		.bi_size = count,
388 	};
389 	struct bio_vec bv;
390 
391 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
392 	for_each_bvec(bv, bvec, bi, bi)
393 		flush_dcache_page(bv.bv_page);
394 }
395 #else
396 static inline void
xs_flush_bvec(const struct bio_vec * bvec,size_t count,size_t seek)397 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
398 {
399 }
400 #endif
401 
402 static ssize_t
xs_read_xdr_buf(struct socket * sock,struct msghdr * msg,int flags,struct xdr_buf * buf,size_t count,size_t seek,size_t * read)403 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
404 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
405 {
406 	size_t want, seek_init = seek, offset = 0;
407 	ssize_t ret;
408 
409 	want = min_t(size_t, count, buf->head[0].iov_len);
410 	if (seek < want) {
411 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
412 		if (ret <= 0)
413 			goto sock_err;
414 		offset += ret;
415 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
416 			goto out;
417 		if (ret != want)
418 			goto out;
419 		seek = 0;
420 	} else {
421 		seek -= want;
422 		offset += want;
423 	}
424 
425 	want = xs_alloc_sparse_pages(buf,
426 			min_t(size_t, count - offset, buf->page_len),
427 			GFP_KERNEL);
428 	if (seek < want) {
429 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
430 				xdr_buf_pagecount(buf),
431 				want + buf->page_base,
432 				seek + buf->page_base);
433 		if (ret <= 0)
434 			goto sock_err;
435 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
436 		ret -= buf->page_base;
437 		offset += ret;
438 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
439 			goto out;
440 		if (ret != want)
441 			goto out;
442 		seek = 0;
443 	} else {
444 		seek -= want;
445 		offset += want;
446 	}
447 
448 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
449 	if (seek < want) {
450 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
451 		if (ret <= 0)
452 			goto sock_err;
453 		offset += ret;
454 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
455 			goto out;
456 		if (ret != want)
457 			goto out;
458 	} else if (offset < seek_init)
459 		offset = seek_init;
460 	ret = -EMSGSIZE;
461 out:
462 	*read = offset - seek_init;
463 	return ret;
464 sock_err:
465 	offset += seek;
466 	goto out;
467 }
468 
469 static void
xs_read_header(struct sock_xprt * transport,struct xdr_buf * buf)470 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
471 {
472 	if (!transport->recv.copied) {
473 		if (buf->head[0].iov_len >= transport->recv.offset)
474 			memcpy(buf->head[0].iov_base,
475 					&transport->recv.xid,
476 					transport->recv.offset);
477 		transport->recv.copied = transport->recv.offset;
478 	}
479 }
480 
481 static bool
xs_read_stream_request_done(struct sock_xprt * transport)482 xs_read_stream_request_done(struct sock_xprt *transport)
483 {
484 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
485 }
486 
487 static void
xs_read_stream_check_eor(struct sock_xprt * transport,struct msghdr * msg)488 xs_read_stream_check_eor(struct sock_xprt *transport,
489 		struct msghdr *msg)
490 {
491 	if (xs_read_stream_request_done(transport))
492 		msg->msg_flags |= MSG_EOR;
493 }
494 
495 static ssize_t
xs_read_stream_request(struct sock_xprt * transport,struct msghdr * msg,int flags,struct rpc_rqst * req)496 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
497 		int flags, struct rpc_rqst *req)
498 {
499 	struct xdr_buf *buf = &req->rq_private_buf;
500 	size_t want, read;
501 	ssize_t ret;
502 
503 	xs_read_header(transport, buf);
504 
505 	want = transport->recv.len - transport->recv.offset;
506 	if (want != 0) {
507 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
508 				transport->recv.copied + want,
509 				transport->recv.copied,
510 				&read);
511 		transport->recv.offset += read;
512 		transport->recv.copied += read;
513 	}
514 
515 	if (transport->recv.offset == transport->recv.len)
516 		xs_read_stream_check_eor(transport, msg);
517 
518 	if (want == 0)
519 		return 0;
520 
521 	switch (ret) {
522 	default:
523 		break;
524 	case -EFAULT:
525 	case -EMSGSIZE:
526 		msg->msg_flags |= MSG_TRUNC;
527 		return read;
528 	case 0:
529 		return -ESHUTDOWN;
530 	}
531 	return ret < 0 ? ret : read;
532 }
533 
534 static size_t
xs_read_stream_headersize(bool isfrag)535 xs_read_stream_headersize(bool isfrag)
536 {
537 	if (isfrag)
538 		return sizeof(__be32);
539 	return 3 * sizeof(__be32);
540 }
541 
542 static ssize_t
xs_read_stream_header(struct sock_xprt * transport,struct msghdr * msg,int flags,size_t want,size_t seek)543 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
544 		int flags, size_t want, size_t seek)
545 {
546 	struct kvec kvec = {
547 		.iov_base = &transport->recv.fraghdr,
548 		.iov_len = want,
549 	};
550 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
551 }
552 
553 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
554 static ssize_t
xs_read_stream_call(struct sock_xprt * transport,struct msghdr * msg,int flags)555 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
556 {
557 	struct rpc_xprt *xprt = &transport->xprt;
558 	struct rpc_rqst *req;
559 	ssize_t ret;
560 
561 	/* Look up and lock the request corresponding to the given XID */
562 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
563 	if (!req) {
564 		printk(KERN_WARNING "Callback slot table overflowed\n");
565 		return -ESHUTDOWN;
566 	}
567 	if (transport->recv.copied && !req->rq_private_buf.len)
568 		return -ESHUTDOWN;
569 
570 	ret = xs_read_stream_request(transport, msg, flags, req);
571 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
572 		xprt_complete_bc_request(req, transport->recv.copied);
573 	else
574 		req->rq_private_buf.len = transport->recv.copied;
575 
576 	return ret;
577 }
578 #else /* CONFIG_SUNRPC_BACKCHANNEL */
579 static ssize_t
xs_read_stream_call(struct sock_xprt * transport,struct msghdr * msg,int flags)580 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
581 {
582 	return -ESHUTDOWN;
583 }
584 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
585 
586 static ssize_t
xs_read_stream_reply(struct sock_xprt * transport,struct msghdr * msg,int flags)587 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
588 {
589 	struct rpc_xprt *xprt = &transport->xprt;
590 	struct rpc_rqst *req;
591 	ssize_t ret = 0;
592 
593 	/* Look up and lock the request corresponding to the given XID */
594 	spin_lock(&xprt->queue_lock);
595 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
596 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
597 		msg->msg_flags |= MSG_TRUNC;
598 		goto out;
599 	}
600 	xprt_pin_rqst(req);
601 	spin_unlock(&xprt->queue_lock);
602 
603 	ret = xs_read_stream_request(transport, msg, flags, req);
604 
605 	spin_lock(&xprt->queue_lock);
606 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
607 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
608 	else
609 		req->rq_private_buf.len = transport->recv.copied;
610 	xprt_unpin_rqst(req);
611 out:
612 	spin_unlock(&xprt->queue_lock);
613 	return ret;
614 }
615 
616 static ssize_t
xs_read_stream(struct sock_xprt * transport,int flags)617 xs_read_stream(struct sock_xprt *transport, int flags)
618 {
619 	struct msghdr msg = { 0 };
620 	size_t want, read = 0;
621 	ssize_t ret = 0;
622 
623 	if (transport->recv.len == 0) {
624 		want = xs_read_stream_headersize(transport->recv.copied != 0);
625 		ret = xs_read_stream_header(transport, &msg, flags, want,
626 				transport->recv.offset);
627 		if (ret <= 0)
628 			goto out_err;
629 		transport->recv.offset = ret;
630 		if (transport->recv.offset != want)
631 			return transport->recv.offset;
632 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
633 			RPC_FRAGMENT_SIZE_MASK;
634 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
635 		read = ret;
636 	}
637 
638 	switch (be32_to_cpu(transport->recv.calldir)) {
639 	default:
640 		msg.msg_flags |= MSG_TRUNC;
641 		break;
642 	case RPC_CALL:
643 		ret = xs_read_stream_call(transport, &msg, flags);
644 		break;
645 	case RPC_REPLY:
646 		ret = xs_read_stream_reply(transport, &msg, flags);
647 	}
648 	if (msg.msg_flags & MSG_TRUNC) {
649 		transport->recv.calldir = cpu_to_be32(-1);
650 		transport->recv.copied = -1;
651 	}
652 	if (ret < 0)
653 		goto out_err;
654 	read += ret;
655 	if (transport->recv.offset < transport->recv.len) {
656 		if (!(msg.msg_flags & MSG_TRUNC))
657 			return read;
658 		msg.msg_flags = 0;
659 		ret = xs_read_discard(transport->sock, &msg, flags,
660 				transport->recv.len - transport->recv.offset);
661 		if (ret <= 0)
662 			goto out_err;
663 		transport->recv.offset += ret;
664 		read += ret;
665 		if (transport->recv.offset != transport->recv.len)
666 			return read;
667 	}
668 	if (xs_read_stream_request_done(transport)) {
669 		trace_xs_stream_read_request(transport);
670 		transport->recv.copied = 0;
671 	}
672 	transport->recv.offset = 0;
673 	transport->recv.len = 0;
674 	return read;
675 out_err:
676 	return ret != 0 ? ret : -ESHUTDOWN;
677 }
678 
xs_poll_socket(struct sock_xprt * transport)679 static __poll_t xs_poll_socket(struct sock_xprt *transport)
680 {
681 	return transport->sock->ops->poll(transport->file, transport->sock,
682 			NULL);
683 }
684 
xs_poll_socket_readable(struct sock_xprt * transport)685 static bool xs_poll_socket_readable(struct sock_xprt *transport)
686 {
687 	__poll_t events = xs_poll_socket(transport);
688 
689 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
690 }
691 
xs_poll_check_readable(struct sock_xprt * transport)692 static void xs_poll_check_readable(struct sock_xprt *transport)
693 {
694 
695 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
696 	if (!xs_poll_socket_readable(transport))
697 		return;
698 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
699 		queue_work(xprtiod_workqueue, &transport->recv_worker);
700 }
701 
xs_stream_data_receive(struct sock_xprt * transport)702 static void xs_stream_data_receive(struct sock_xprt *transport)
703 {
704 	size_t read = 0;
705 	ssize_t ret = 0;
706 
707 	mutex_lock(&transport->recv_mutex);
708 	if (transport->sock == NULL)
709 		goto out;
710 	for (;;) {
711 		ret = xs_read_stream(transport, MSG_DONTWAIT);
712 		if (ret < 0)
713 			break;
714 		read += ret;
715 		cond_resched();
716 	}
717 	if (ret == -ESHUTDOWN)
718 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
719 	else
720 		xs_poll_check_readable(transport);
721 out:
722 	mutex_unlock(&transport->recv_mutex);
723 	trace_xs_stream_read_data(&transport->xprt, ret, read);
724 }
725 
xs_stream_data_receive_workfn(struct work_struct * work)726 static void xs_stream_data_receive_workfn(struct work_struct *work)
727 {
728 	struct sock_xprt *transport =
729 		container_of(work, struct sock_xprt, recv_worker);
730 	unsigned int pflags = memalloc_nofs_save();
731 
732 	xs_stream_data_receive(transport);
733 	memalloc_nofs_restore(pflags);
734 }
735 
736 static void
xs_stream_reset_connect(struct sock_xprt * transport)737 xs_stream_reset_connect(struct sock_xprt *transport)
738 {
739 	transport->recv.offset = 0;
740 	transport->recv.len = 0;
741 	transport->recv.copied = 0;
742 	transport->xmit.offset = 0;
743 }
744 
745 static void
xs_stream_start_connect(struct sock_xprt * transport)746 xs_stream_start_connect(struct sock_xprt *transport)
747 {
748 	transport->xprt.stat.connect_count++;
749 	transport->xprt.stat.connect_start = jiffies;
750 }
751 
752 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
753 
754 /**
755  * xs_nospace - handle transmit was incomplete
756  * @req: pointer to RPC request
757  *
758  */
xs_nospace(struct rpc_rqst * req)759 static int xs_nospace(struct rpc_rqst *req)
760 {
761 	struct rpc_xprt *xprt = req->rq_xprt;
762 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
763 	struct sock *sk = transport->inet;
764 	int ret = -EAGAIN;
765 
766 	trace_rpc_socket_nospace(req, transport);
767 
768 	/* Protect against races with write_space */
769 	spin_lock(&xprt->transport_lock);
770 
771 	/* Don't race with disconnect */
772 	if (xprt_connected(xprt)) {
773 		/* wait for more buffer space */
774 		sk->sk_write_pending++;
775 		xprt_wait_for_buffer_space(xprt);
776 	} else
777 		ret = -ENOTCONN;
778 
779 	spin_unlock(&xprt->transport_lock);
780 
781 	/* Race breaker in case memory is freed before above code is called */
782 	if (ret == -EAGAIN) {
783 		struct socket_wq *wq;
784 
785 		rcu_read_lock();
786 		wq = rcu_dereference(sk->sk_wq);
787 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
788 		rcu_read_unlock();
789 
790 		sk->sk_write_space(sk);
791 	}
792 	return ret;
793 }
794 
795 static void
xs_stream_prepare_request(struct rpc_rqst * req)796 xs_stream_prepare_request(struct rpc_rqst *req)
797 {
798 	xdr_free_bvec(&req->rq_rcv_buf);
799 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
800 }
801 
802 /*
803  * Determine if the previous message in the stream was aborted before it
804  * could complete transmission.
805  */
806 static bool
xs_send_request_was_aborted(struct sock_xprt * transport,struct rpc_rqst * req)807 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
808 {
809 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
810 }
811 
812 /*
813  * Return the stream record marker field for a record of length < 2^31-1
814  */
815 static rpc_fraghdr
xs_stream_record_marker(struct xdr_buf * xdr)816 xs_stream_record_marker(struct xdr_buf *xdr)
817 {
818 	if (!xdr->len)
819 		return 0;
820 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
821 }
822 
823 /**
824  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
825  * @req: pointer to RPC request
826  *
827  * Return values:
828  *        0:	The request has been sent
829  *   EAGAIN:	The socket was blocked, please call again later to
830  *		complete the request
831  * ENOTCONN:	Caller needs to invoke connect logic then call again
832  *    other:	Some other error occured, the request was not sent
833  */
xs_local_send_request(struct rpc_rqst * req)834 static int xs_local_send_request(struct rpc_rqst *req)
835 {
836 	struct rpc_xprt *xprt = req->rq_xprt;
837 	struct sock_xprt *transport =
838 				container_of(xprt, struct sock_xprt, xprt);
839 	struct xdr_buf *xdr = &req->rq_snd_buf;
840 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
841 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
842 	struct msghdr msg = {
843 		.msg_flags	= XS_SENDMSG_FLAGS,
844 	};
845 	unsigned int sent;
846 	int status;
847 
848 	/* Close the stream if the previous transmission was incomplete */
849 	if (xs_send_request_was_aborted(transport, req)) {
850 		xprt_force_disconnect(xprt);
851 		return -ENOTCONN;
852 	}
853 
854 	xs_pktdump("packet data:",
855 			req->rq_svec->iov_base, req->rq_svec->iov_len);
856 
857 	req->rq_xtime = ktime_get();
858 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
859 				   transport->xmit.offset, rm, &sent);
860 	dprintk("RPC:       %s(%u) = %d\n",
861 			__func__, xdr->len - transport->xmit.offset, status);
862 
863 	if (status == -EAGAIN && sock_writeable(transport->inet))
864 		status = -ENOBUFS;
865 
866 	if (likely(sent > 0) || status == 0) {
867 		transport->xmit.offset += sent;
868 		req->rq_bytes_sent = transport->xmit.offset;
869 		if (likely(req->rq_bytes_sent >= msglen)) {
870 			req->rq_xmit_bytes_sent += transport->xmit.offset;
871 			transport->xmit.offset = 0;
872 			return 0;
873 		}
874 		status = -EAGAIN;
875 	}
876 
877 	switch (status) {
878 	case -ENOBUFS:
879 		break;
880 	case -EAGAIN:
881 		status = xs_nospace(req);
882 		break;
883 	default:
884 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
885 			-status);
886 		fallthrough;
887 	case -EPIPE:
888 		xprt_force_disconnect(xprt);
889 		status = -ENOTCONN;
890 	}
891 
892 	return status;
893 }
894 
895 /**
896  * xs_udp_send_request - write an RPC request to a UDP socket
897  * @req: pointer to RPC request
898  *
899  * Return values:
900  *        0:	The request has been sent
901  *   EAGAIN:	The socket was blocked, please call again later to
902  *		complete the request
903  * ENOTCONN:	Caller needs to invoke connect logic then call again
904  *    other:	Some other error occurred, the request was not sent
905  */
xs_udp_send_request(struct rpc_rqst * req)906 static int xs_udp_send_request(struct rpc_rqst *req)
907 {
908 	struct rpc_xprt *xprt = req->rq_xprt;
909 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
910 	struct xdr_buf *xdr = &req->rq_snd_buf;
911 	struct msghdr msg = {
912 		.msg_name	= xs_addr(xprt),
913 		.msg_namelen	= xprt->addrlen,
914 		.msg_flags	= XS_SENDMSG_FLAGS,
915 	};
916 	unsigned int sent;
917 	int status;
918 
919 	xs_pktdump("packet data:",
920 				req->rq_svec->iov_base,
921 				req->rq_svec->iov_len);
922 
923 	if (!xprt_bound(xprt))
924 		return -ENOTCONN;
925 
926 	if (!xprt_request_get_cong(xprt, req))
927 		return -EBADSLT;
928 
929 	req->rq_xtime = ktime_get();
930 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
931 
932 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
933 			xdr->len, status);
934 
935 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
936 	if (status == -EPERM)
937 		goto process_status;
938 
939 	if (status == -EAGAIN && sock_writeable(transport->inet))
940 		status = -ENOBUFS;
941 
942 	if (sent > 0 || status == 0) {
943 		req->rq_xmit_bytes_sent += sent;
944 		if (sent >= req->rq_slen)
945 			return 0;
946 		/* Still some bytes left; set up for a retry later. */
947 		status = -EAGAIN;
948 	}
949 
950 process_status:
951 	switch (status) {
952 	case -ENOTSOCK:
953 		status = -ENOTCONN;
954 		/* Should we call xs_close() here? */
955 		break;
956 	case -EAGAIN:
957 		status = xs_nospace(req);
958 		break;
959 	case -ENETUNREACH:
960 	case -ENOBUFS:
961 	case -EPIPE:
962 	case -ECONNREFUSED:
963 	case -EPERM:
964 		/* When the server has died, an ICMP port unreachable message
965 		 * prompts ECONNREFUSED. */
966 		break;
967 	default:
968 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
969 			-status);
970 	}
971 
972 	return status;
973 }
974 
975 /**
976  * xs_tcp_send_request - write an RPC request to a TCP socket
977  * @req: pointer to RPC request
978  *
979  * Return values:
980  *        0:	The request has been sent
981  *   EAGAIN:	The socket was blocked, please call again later to
982  *		complete the request
983  * ENOTCONN:	Caller needs to invoke connect logic then call again
984  *    other:	Some other error occurred, the request was not sent
985  *
986  * XXX: In the case of soft timeouts, should we eventually give up
987  *	if sendmsg is not able to make progress?
988  */
xs_tcp_send_request(struct rpc_rqst * req)989 static int xs_tcp_send_request(struct rpc_rqst *req)
990 {
991 	struct rpc_xprt *xprt = req->rq_xprt;
992 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
993 	struct xdr_buf *xdr = &req->rq_snd_buf;
994 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
995 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
996 	struct msghdr msg = {
997 		.msg_flags	= XS_SENDMSG_FLAGS,
998 	};
999 	bool vm_wait = false;
1000 	unsigned int sent;
1001 	int status;
1002 
1003 	/* Close the stream if the previous transmission was incomplete */
1004 	if (xs_send_request_was_aborted(transport, req)) {
1005 		if (transport->sock != NULL)
1006 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1007 		return -ENOTCONN;
1008 	}
1009 
1010 	xs_pktdump("packet data:",
1011 				req->rq_svec->iov_base,
1012 				req->rq_svec->iov_len);
1013 
1014 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1015 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1016 
1017 	/* Continue transmitting the packet/record. We must be careful
1018 	 * to cope with writespace callbacks arriving _after_ we have
1019 	 * called sendmsg(). */
1020 	req->rq_xtime = ktime_get();
1021 	while (1) {
1022 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1023 					   transport->xmit.offset, rm, &sent);
1024 
1025 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1026 				xdr->len - transport->xmit.offset, status);
1027 
1028 		/* If we've sent the entire packet, immediately
1029 		 * reset the count of bytes sent. */
1030 		transport->xmit.offset += sent;
1031 		req->rq_bytes_sent = transport->xmit.offset;
1032 		if (likely(req->rq_bytes_sent >= msglen)) {
1033 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1034 			transport->xmit.offset = 0;
1035 			return 0;
1036 		}
1037 
1038 		WARN_ON_ONCE(sent == 0 && status == 0);
1039 
1040 		if (status == -EAGAIN ) {
1041 			/*
1042 			 * Return EAGAIN if we're sure we're hitting the
1043 			 * socket send buffer limits.
1044 			 */
1045 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1046 				break;
1047 			/*
1048 			 * Did we hit a memory allocation failure?
1049 			 */
1050 			if (sent == 0) {
1051 				status = -ENOBUFS;
1052 				if (vm_wait)
1053 					break;
1054 				/* Retry, knowing now that we're below the
1055 				 * socket send buffer limit
1056 				 */
1057 				vm_wait = true;
1058 			}
1059 			continue;
1060 		}
1061 		if (status < 0)
1062 			break;
1063 		vm_wait = false;
1064 	}
1065 
1066 	switch (status) {
1067 	case -ENOTSOCK:
1068 		status = -ENOTCONN;
1069 		/* Should we call xs_close() here? */
1070 		break;
1071 	case -EAGAIN:
1072 		status = xs_nospace(req);
1073 		break;
1074 	case -ECONNRESET:
1075 	case -ECONNREFUSED:
1076 	case -ENOTCONN:
1077 	case -EADDRINUSE:
1078 	case -ENOBUFS:
1079 	case -EPIPE:
1080 		break;
1081 	default:
1082 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1083 			-status);
1084 	}
1085 
1086 	return status;
1087 }
1088 
xs_save_old_callbacks(struct sock_xprt * transport,struct sock * sk)1089 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1090 {
1091 	transport->old_data_ready = sk->sk_data_ready;
1092 	transport->old_state_change = sk->sk_state_change;
1093 	transport->old_write_space = sk->sk_write_space;
1094 	transport->old_error_report = sk->sk_error_report;
1095 }
1096 
xs_restore_old_callbacks(struct sock_xprt * transport,struct sock * sk)1097 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1098 {
1099 	sk->sk_data_ready = transport->old_data_ready;
1100 	sk->sk_state_change = transport->old_state_change;
1101 	sk->sk_write_space = transport->old_write_space;
1102 	sk->sk_error_report = transport->old_error_report;
1103 }
1104 
xs_sock_reset_state_flags(struct rpc_xprt * xprt)1105 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1106 {
1107 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1108 
1109 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1110 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1111 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1112 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1113 }
1114 
xs_run_error_worker(struct sock_xprt * transport,unsigned int nr)1115 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1116 {
1117 	set_bit(nr, &transport->sock_state);
1118 	queue_work(xprtiod_workqueue, &transport->error_worker);
1119 }
1120 
xs_sock_reset_connection_flags(struct rpc_xprt * xprt)1121 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1122 {
1123 	smp_mb__before_atomic();
1124 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1125 	clear_bit(XPRT_CLOSING, &xprt->state);
1126 	xs_sock_reset_state_flags(xprt);
1127 	smp_mb__after_atomic();
1128 }
1129 
1130 /**
1131  * xs_error_report - callback to handle TCP socket state errors
1132  * @sk: socket
1133  *
1134  * Note: we don't call sock_error() since there may be a rpc_task
1135  * using the socket, and so we don't want to clear sk->sk_err.
1136  */
xs_error_report(struct sock * sk)1137 static void xs_error_report(struct sock *sk)
1138 {
1139 	struct sock_xprt *transport;
1140 	struct rpc_xprt *xprt;
1141 
1142 	read_lock_bh(&sk->sk_callback_lock);
1143 	if (!(xprt = xprt_from_sock(sk)))
1144 		goto out;
1145 
1146 	transport = container_of(xprt, struct sock_xprt, xprt);
1147 	transport->xprt_err = -sk->sk_err;
1148 	if (transport->xprt_err == 0)
1149 		goto out;
1150 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1151 			xprt, -transport->xprt_err);
1152 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1153 
1154 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1155 	smp_mb__before_atomic();
1156 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1157  out:
1158 	read_unlock_bh(&sk->sk_callback_lock);
1159 }
1160 
xs_reset_transport(struct sock_xprt * transport)1161 static void xs_reset_transport(struct sock_xprt *transport)
1162 {
1163 	struct socket *sock = transport->sock;
1164 	struct sock *sk = transport->inet;
1165 	struct rpc_xprt *xprt = &transport->xprt;
1166 	struct file *filp = transport->file;
1167 
1168 	if (sk == NULL)
1169 		return;
1170 	/*
1171 	 * Make sure we're calling this in a context from which it is safe
1172 	 * to call __fput_sync(). In practice that means rpciod and the
1173 	 * system workqueue.
1174 	 */
1175 	if (!(current->flags & PF_WQ_WORKER)) {
1176 		WARN_ON_ONCE(1);
1177 		set_bit(XPRT_CLOSE_WAIT, &xprt->state);
1178 		return;
1179 	}
1180 
1181 	if (atomic_read(&transport->xprt.swapper))
1182 		sk_clear_memalloc(sk);
1183 
1184 	kernel_sock_shutdown(sock, SHUT_RDWR);
1185 
1186 	mutex_lock(&transport->recv_mutex);
1187 	write_lock_bh(&sk->sk_callback_lock);
1188 	transport->inet = NULL;
1189 	transport->sock = NULL;
1190 	transport->file = NULL;
1191 
1192 	sk->sk_user_data = NULL;
1193 
1194 	xs_restore_old_callbacks(transport, sk);
1195 	xprt_clear_connected(xprt);
1196 	write_unlock_bh(&sk->sk_callback_lock);
1197 	xs_sock_reset_connection_flags(xprt);
1198 	/* Reset stream record info */
1199 	xs_stream_reset_connect(transport);
1200 	mutex_unlock(&transport->recv_mutex);
1201 
1202 	trace_rpc_socket_close(xprt, sock);
1203 	__fput_sync(filp);
1204 
1205 	xprt_disconnect_done(xprt);
1206 }
1207 
1208 /**
1209  * xs_close - close a socket
1210  * @xprt: transport
1211  *
1212  * This is used when all requests are complete; ie, no DRC state remains
1213  * on the server we want to save.
1214  *
1215  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1216  * xs_reset_transport() zeroing the socket from underneath a writer.
1217  */
xs_close(struct rpc_xprt * xprt)1218 static void xs_close(struct rpc_xprt *xprt)
1219 {
1220 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1221 
1222 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1223 
1224 	xs_reset_transport(transport);
1225 	xprt->reestablish_timeout = 0;
1226 }
1227 
xs_inject_disconnect(struct rpc_xprt * xprt)1228 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1229 {
1230 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1231 		xprt);
1232 	xprt_disconnect_done(xprt);
1233 }
1234 
xs_xprt_free(struct rpc_xprt * xprt)1235 static void xs_xprt_free(struct rpc_xprt *xprt)
1236 {
1237 	xs_free_peer_addresses(xprt);
1238 	xprt_free(xprt);
1239 }
1240 
1241 /**
1242  * xs_destroy - prepare to shutdown a transport
1243  * @xprt: doomed transport
1244  *
1245  */
xs_destroy(struct rpc_xprt * xprt)1246 static void xs_destroy(struct rpc_xprt *xprt)
1247 {
1248 	struct sock_xprt *transport = container_of(xprt,
1249 			struct sock_xprt, xprt);
1250 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1251 
1252 	cancel_delayed_work_sync(&transport->connect_worker);
1253 	xs_close(xprt);
1254 	cancel_work_sync(&transport->recv_worker);
1255 	cancel_work_sync(&transport->error_worker);
1256 	xs_xprt_free(xprt);
1257 	module_put(THIS_MODULE);
1258 }
1259 
1260 /**
1261  * xs_udp_data_read_skb - receive callback for UDP sockets
1262  * @xprt: transport
1263  * @sk: socket
1264  * @skb: skbuff
1265  *
1266  */
xs_udp_data_read_skb(struct rpc_xprt * xprt,struct sock * sk,struct sk_buff * skb)1267 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1268 		struct sock *sk,
1269 		struct sk_buff *skb)
1270 {
1271 	struct rpc_task *task;
1272 	struct rpc_rqst *rovr;
1273 	int repsize, copied;
1274 	u32 _xid;
1275 	__be32 *xp;
1276 
1277 	repsize = skb->len;
1278 	if (repsize < 4) {
1279 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1280 		return;
1281 	}
1282 
1283 	/* Copy the XID from the skb... */
1284 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1285 	if (xp == NULL)
1286 		return;
1287 
1288 	/* Look up and lock the request corresponding to the given XID */
1289 	spin_lock(&xprt->queue_lock);
1290 	rovr = xprt_lookup_rqst(xprt, *xp);
1291 	if (!rovr)
1292 		goto out_unlock;
1293 	xprt_pin_rqst(rovr);
1294 	xprt_update_rtt(rovr->rq_task);
1295 	spin_unlock(&xprt->queue_lock);
1296 	task = rovr->rq_task;
1297 
1298 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1299 		copied = repsize;
1300 
1301 	/* Suck it into the iovec, verify checksum if not done by hw. */
1302 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1303 		spin_lock(&xprt->queue_lock);
1304 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1305 		goto out_unpin;
1306 	}
1307 
1308 
1309 	spin_lock(&xprt->transport_lock);
1310 	xprt_adjust_cwnd(xprt, task, copied);
1311 	spin_unlock(&xprt->transport_lock);
1312 	spin_lock(&xprt->queue_lock);
1313 	xprt_complete_rqst(task, copied);
1314 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1315 out_unpin:
1316 	xprt_unpin_rqst(rovr);
1317  out_unlock:
1318 	spin_unlock(&xprt->queue_lock);
1319 }
1320 
xs_udp_data_receive(struct sock_xprt * transport)1321 static void xs_udp_data_receive(struct sock_xprt *transport)
1322 {
1323 	struct sk_buff *skb;
1324 	struct sock *sk;
1325 	int err;
1326 
1327 	mutex_lock(&transport->recv_mutex);
1328 	sk = transport->inet;
1329 	if (sk == NULL)
1330 		goto out;
1331 	for (;;) {
1332 		skb = skb_recv_udp(sk, 0, 1, &err);
1333 		if (skb == NULL)
1334 			break;
1335 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1336 		consume_skb(skb);
1337 		cond_resched();
1338 	}
1339 	xs_poll_check_readable(transport);
1340 out:
1341 	mutex_unlock(&transport->recv_mutex);
1342 }
1343 
xs_udp_data_receive_workfn(struct work_struct * work)1344 static void xs_udp_data_receive_workfn(struct work_struct *work)
1345 {
1346 	struct sock_xprt *transport =
1347 		container_of(work, struct sock_xprt, recv_worker);
1348 	unsigned int pflags = memalloc_nofs_save();
1349 
1350 	xs_udp_data_receive(transport);
1351 	memalloc_nofs_restore(pflags);
1352 }
1353 
1354 /**
1355  * xs_data_ready - "data ready" callback for UDP sockets
1356  * @sk: socket with data to read
1357  *
1358  */
xs_data_ready(struct sock * sk)1359 static void xs_data_ready(struct sock *sk)
1360 {
1361 	struct rpc_xprt *xprt;
1362 
1363 	read_lock_bh(&sk->sk_callback_lock);
1364 	dprintk("RPC:       xs_data_ready...\n");
1365 	xprt = xprt_from_sock(sk);
1366 	if (xprt != NULL) {
1367 		struct sock_xprt *transport = container_of(xprt,
1368 				struct sock_xprt, xprt);
1369 		transport->old_data_ready(sk);
1370 		/* Any data means we had a useful conversation, so
1371 		 * then we don't need to delay the next reconnect
1372 		 */
1373 		if (xprt->reestablish_timeout)
1374 			xprt->reestablish_timeout = 0;
1375 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1376 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1377 	}
1378 	read_unlock_bh(&sk->sk_callback_lock);
1379 }
1380 
1381 /*
1382  * Helper function to force a TCP close if the server is sending
1383  * junk and/or it has put us in CLOSE_WAIT
1384  */
xs_tcp_force_close(struct rpc_xprt * xprt)1385 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1386 {
1387 	xprt_force_disconnect(xprt);
1388 }
1389 
1390 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
xs_tcp_bc_maxpayload(struct rpc_xprt * xprt)1391 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1392 {
1393 	return PAGE_SIZE;
1394 }
1395 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1396 
1397 /**
1398  * xs_tcp_state_change - callback to handle TCP socket state changes
1399  * @sk: socket whose state has changed
1400  *
1401  */
xs_tcp_state_change(struct sock * sk)1402 static void xs_tcp_state_change(struct sock *sk)
1403 {
1404 	struct rpc_xprt *xprt;
1405 	struct sock_xprt *transport;
1406 
1407 	read_lock_bh(&sk->sk_callback_lock);
1408 	if (!(xprt = xprt_from_sock(sk)))
1409 		goto out;
1410 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1411 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1412 			sk->sk_state, xprt_connected(xprt),
1413 			sock_flag(sk, SOCK_DEAD),
1414 			sock_flag(sk, SOCK_ZAPPED),
1415 			sk->sk_shutdown);
1416 
1417 	transport = container_of(xprt, struct sock_xprt, xprt);
1418 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1419 	switch (sk->sk_state) {
1420 	case TCP_ESTABLISHED:
1421 		if (!xprt_test_and_set_connected(xprt)) {
1422 			xprt->connect_cookie++;
1423 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1424 			xprt_clear_connecting(xprt);
1425 
1426 			xprt->stat.connect_count++;
1427 			xprt->stat.connect_time += (long)jiffies -
1428 						   xprt->stat.connect_start;
1429 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1430 		}
1431 		break;
1432 	case TCP_FIN_WAIT1:
1433 		/* The client initiated a shutdown of the socket */
1434 		xprt->connect_cookie++;
1435 		xprt->reestablish_timeout = 0;
1436 		set_bit(XPRT_CLOSING, &xprt->state);
1437 		smp_mb__before_atomic();
1438 		clear_bit(XPRT_CONNECTED, &xprt->state);
1439 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1440 		smp_mb__after_atomic();
1441 		break;
1442 	case TCP_CLOSE_WAIT:
1443 		/* The server initiated a shutdown of the socket */
1444 		xprt->connect_cookie++;
1445 		clear_bit(XPRT_CONNECTED, &xprt->state);
1446 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1447 		fallthrough;
1448 	case TCP_CLOSING:
1449 		/*
1450 		 * If the server closed down the connection, make sure that
1451 		 * we back off before reconnecting
1452 		 */
1453 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1454 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1455 		break;
1456 	case TCP_LAST_ACK:
1457 		set_bit(XPRT_CLOSING, &xprt->state);
1458 		smp_mb__before_atomic();
1459 		clear_bit(XPRT_CONNECTED, &xprt->state);
1460 		smp_mb__after_atomic();
1461 		break;
1462 	case TCP_CLOSE:
1463 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1464 					&transport->sock_state))
1465 			xprt_clear_connecting(xprt);
1466 		clear_bit(XPRT_CLOSING, &xprt->state);
1467 		/* Trigger the socket release */
1468 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1469 	}
1470  out:
1471 	read_unlock_bh(&sk->sk_callback_lock);
1472 }
1473 
xs_write_space(struct sock * sk)1474 static void xs_write_space(struct sock *sk)
1475 {
1476 	struct socket_wq *wq;
1477 	struct sock_xprt *transport;
1478 	struct rpc_xprt *xprt;
1479 
1480 	if (!sk->sk_socket)
1481 		return;
1482 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1483 
1484 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1485 		return;
1486 	transport = container_of(xprt, struct sock_xprt, xprt);
1487 	rcu_read_lock();
1488 	wq = rcu_dereference(sk->sk_wq);
1489 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1490 		goto out;
1491 
1492 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1493 	sk->sk_write_pending--;
1494 out:
1495 	rcu_read_unlock();
1496 }
1497 
1498 /**
1499  * xs_udp_write_space - callback invoked when socket buffer space
1500  *                             becomes available
1501  * @sk: socket whose state has changed
1502  *
1503  * Called when more output buffer space is available for this socket.
1504  * We try not to wake our writers until they can make "significant"
1505  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1506  * with a bunch of small requests.
1507  */
xs_udp_write_space(struct sock * sk)1508 static void xs_udp_write_space(struct sock *sk)
1509 {
1510 	read_lock_bh(&sk->sk_callback_lock);
1511 
1512 	/* from net/core/sock.c:sock_def_write_space */
1513 	if (sock_writeable(sk))
1514 		xs_write_space(sk);
1515 
1516 	read_unlock_bh(&sk->sk_callback_lock);
1517 }
1518 
1519 /**
1520  * xs_tcp_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  */
xs_tcp_write_space(struct sock * sk)1529 static void xs_tcp_write_space(struct sock *sk)
1530 {
1531 	read_lock_bh(&sk->sk_callback_lock);
1532 
1533 	/* from net/core/stream.c:sk_stream_write_space */
1534 	if (sk_stream_is_writeable(sk))
1535 		xs_write_space(sk);
1536 
1537 	read_unlock_bh(&sk->sk_callback_lock);
1538 }
1539 
xs_udp_do_set_buffer_size(struct rpc_xprt * xprt)1540 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1541 {
1542 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1543 	struct sock *sk = transport->inet;
1544 
1545 	if (transport->rcvsize) {
1546 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1547 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1548 	}
1549 	if (transport->sndsize) {
1550 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1551 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1552 		sk->sk_write_space(sk);
1553 	}
1554 }
1555 
1556 /**
1557  * xs_udp_set_buffer_size - set send and receive limits
1558  * @xprt: generic transport
1559  * @sndsize: requested size of send buffer, in bytes
1560  * @rcvsize: requested size of receive buffer, in bytes
1561  *
1562  * Set socket send and receive buffer size limits.
1563  */
xs_udp_set_buffer_size(struct rpc_xprt * xprt,size_t sndsize,size_t rcvsize)1564 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1565 {
1566 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1567 
1568 	transport->sndsize = 0;
1569 	if (sndsize)
1570 		transport->sndsize = sndsize + 1024;
1571 	transport->rcvsize = 0;
1572 	if (rcvsize)
1573 		transport->rcvsize = rcvsize + 1024;
1574 
1575 	xs_udp_do_set_buffer_size(xprt);
1576 }
1577 
1578 /**
1579  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1580  * @xprt: controlling transport
1581  * @task: task that timed out
1582  *
1583  * Adjust the congestion window after a retransmit timeout has occurred.
1584  */
xs_udp_timer(struct rpc_xprt * xprt,struct rpc_task * task)1585 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1586 {
1587 	spin_lock(&xprt->transport_lock);
1588 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1589 	spin_unlock(&xprt->transport_lock);
1590 }
1591 
xs_get_random_port(void)1592 static int xs_get_random_port(void)
1593 {
1594 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1595 	unsigned short range;
1596 	unsigned short rand;
1597 
1598 	if (max < min)
1599 		return -EADDRINUSE;
1600 	range = max - min + 1;
1601 	rand = (unsigned short) prandom_u32() % range;
1602 	return rand + min;
1603 }
1604 
xs_sock_getport(struct socket * sock)1605 static unsigned short xs_sock_getport(struct socket *sock)
1606 {
1607 	struct sockaddr_storage buf;
1608 	unsigned short port = 0;
1609 
1610 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1611 		goto out;
1612 	switch (buf.ss_family) {
1613 	case AF_INET6:
1614 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1615 		break;
1616 	case AF_INET:
1617 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1618 	}
1619 out:
1620 	return port;
1621 }
1622 
1623 /**
1624  * xs_set_port - reset the port number in the remote endpoint address
1625  * @xprt: generic transport
1626  * @port: new port number
1627  *
1628  */
xs_set_port(struct rpc_xprt * xprt,unsigned short port)1629 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1630 {
1631 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1632 
1633 	rpc_set_port(xs_addr(xprt), port);
1634 	xs_update_peer_port(xprt);
1635 }
1636 
xs_set_srcport(struct sock_xprt * transport,struct socket * sock)1637 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1638 {
1639 	if (transport->srcport == 0 && transport->xprt.reuseport)
1640 		transport->srcport = xs_sock_getport(sock);
1641 }
1642 
xs_get_srcport(struct sock_xprt * transport)1643 static int xs_get_srcport(struct sock_xprt *transport)
1644 {
1645 	int port = transport->srcport;
1646 
1647 	if (port == 0 && transport->xprt.resvport)
1648 		port = xs_get_random_port();
1649 	return port;
1650 }
1651 
get_srcport(struct rpc_xprt * xprt)1652 unsigned short get_srcport(struct rpc_xprt *xprt)
1653 {
1654 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1655 	return xs_sock_getport(sock->sock);
1656 }
1657 EXPORT_SYMBOL(get_srcport);
1658 
xs_next_srcport(struct sock_xprt * transport,unsigned short port)1659 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1660 {
1661 	if (transport->srcport != 0)
1662 		transport->srcport = 0;
1663 	if (!transport->xprt.resvport)
1664 		return 0;
1665 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1666 		return xprt_max_resvport;
1667 	return --port;
1668 }
xs_bind(struct sock_xprt * transport,struct socket * sock)1669 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1670 {
1671 	struct sockaddr_storage myaddr;
1672 	int err, nloop = 0;
1673 	int port = xs_get_srcport(transport);
1674 	unsigned short last;
1675 
1676 	/*
1677 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1678 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1679 	 * port selection happen implicitly when the socket is used
1680 	 * (for example at connect time).
1681 	 *
1682 	 * This ensures that we can continue to establish TCP
1683 	 * connections even when all local ephemeral ports are already
1684 	 * a part of some TCP connection.  This makes no difference
1685 	 * for UDP sockets, but also doens't harm them.
1686 	 *
1687 	 * If we're asking for any reserved port (i.e. port == 0 &&
1688 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1689 	 * ensure that port is non-zero and we will bind as needed.
1690 	 */
1691 	if (port <= 0)
1692 		return port;
1693 
1694 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1695 	do {
1696 		rpc_set_port((struct sockaddr *)&myaddr, port);
1697 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1698 				transport->xprt.addrlen);
1699 		if (err == 0) {
1700 			if (transport->xprt.reuseport)
1701 				transport->srcport = port;
1702 			break;
1703 		}
1704 		last = port;
1705 		port = xs_next_srcport(transport, port);
1706 		if (port > last)
1707 			nloop++;
1708 	} while (err == -EADDRINUSE && nloop != 2);
1709 
1710 	if (myaddr.ss_family == AF_INET)
1711 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1712 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1713 				port, err ? "failed" : "ok", err);
1714 	else
1715 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1716 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1717 				port, err ? "failed" : "ok", err);
1718 	return err;
1719 }
1720 
1721 /*
1722  * We don't support autobind on AF_LOCAL sockets
1723  */
xs_local_rpcbind(struct rpc_task * task)1724 static void xs_local_rpcbind(struct rpc_task *task)
1725 {
1726 	xprt_set_bound(task->tk_xprt);
1727 }
1728 
xs_local_set_port(struct rpc_xprt * xprt,unsigned short port)1729 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1730 {
1731 }
1732 
1733 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1734 static struct lock_class_key xs_key[2];
1735 static struct lock_class_key xs_slock_key[2];
1736 
xs_reclassify_socketu(struct socket * sock)1737 static inline void xs_reclassify_socketu(struct socket *sock)
1738 {
1739 	struct sock *sk = sock->sk;
1740 
1741 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1742 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1743 }
1744 
xs_reclassify_socket4(struct socket * sock)1745 static inline void xs_reclassify_socket4(struct socket *sock)
1746 {
1747 	struct sock *sk = sock->sk;
1748 
1749 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1750 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1751 }
1752 
xs_reclassify_socket6(struct socket * sock)1753 static inline void xs_reclassify_socket6(struct socket *sock)
1754 {
1755 	struct sock *sk = sock->sk;
1756 
1757 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1758 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1759 }
1760 
xs_reclassify_socket(int family,struct socket * sock)1761 static inline void xs_reclassify_socket(int family, struct socket *sock)
1762 {
1763 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1764 		return;
1765 
1766 	switch (family) {
1767 	case AF_LOCAL:
1768 		xs_reclassify_socketu(sock);
1769 		break;
1770 	case AF_INET:
1771 		xs_reclassify_socket4(sock);
1772 		break;
1773 	case AF_INET6:
1774 		xs_reclassify_socket6(sock);
1775 		break;
1776 	}
1777 }
1778 #else
xs_reclassify_socket(int family,struct socket * sock)1779 static inline void xs_reclassify_socket(int family, struct socket *sock)
1780 {
1781 }
1782 #endif
1783 
xs_dummy_setup_socket(struct work_struct * work)1784 static void xs_dummy_setup_socket(struct work_struct *work)
1785 {
1786 }
1787 
xs_create_sock(struct rpc_xprt * xprt,struct sock_xprt * transport,int family,int type,int protocol,bool reuseport)1788 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1789 		struct sock_xprt *transport, int family, int type,
1790 		int protocol, bool reuseport)
1791 {
1792 	struct file *filp;
1793 	struct socket *sock;
1794 	int err;
1795 
1796 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1797 	if (err < 0) {
1798 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1799 				protocol, -err);
1800 		goto out;
1801 	}
1802 	xs_reclassify_socket(family, sock);
1803 
1804 	if (reuseport)
1805 		sock_set_reuseport(sock->sk);
1806 
1807 	err = xs_bind(transport, sock);
1808 	if (err) {
1809 		sock_release(sock);
1810 		goto out;
1811 	}
1812 
1813 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1814 	if (IS_ERR(filp))
1815 		return ERR_CAST(filp);
1816 	transport->file = filp;
1817 
1818 	return sock;
1819 out:
1820 	return ERR_PTR(err);
1821 }
1822 
xs_local_finish_connecting(struct rpc_xprt * xprt,struct socket * sock)1823 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1824 				      struct socket *sock)
1825 {
1826 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1827 									xprt);
1828 
1829 	if (!transport->inet) {
1830 		struct sock *sk = sock->sk;
1831 
1832 		write_lock_bh(&sk->sk_callback_lock);
1833 
1834 		xs_save_old_callbacks(transport, sk);
1835 
1836 		sk->sk_user_data = xprt;
1837 		sk->sk_data_ready = xs_data_ready;
1838 		sk->sk_write_space = xs_udp_write_space;
1839 		sock_set_flag(sk, SOCK_FASYNC);
1840 		sk->sk_error_report = xs_error_report;
1841 
1842 		xprt_clear_connected(xprt);
1843 
1844 		/* Reset to new socket */
1845 		transport->sock = sock;
1846 		transport->inet = sk;
1847 
1848 		write_unlock_bh(&sk->sk_callback_lock);
1849 	}
1850 
1851 	xs_stream_start_connect(transport);
1852 
1853 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1854 }
1855 
1856 /**
1857  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1858  * @transport: socket transport to connect
1859  */
xs_local_setup_socket(struct sock_xprt * transport)1860 static int xs_local_setup_socket(struct sock_xprt *transport)
1861 {
1862 	struct rpc_xprt *xprt = &transport->xprt;
1863 	struct file *filp;
1864 	struct socket *sock;
1865 	int status;
1866 
1867 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1868 					SOCK_STREAM, 0, &sock, 1);
1869 	if (status < 0) {
1870 		dprintk("RPC:       can't create AF_LOCAL "
1871 			"transport socket (%d).\n", -status);
1872 		goto out;
1873 	}
1874 	xs_reclassify_socket(AF_LOCAL, sock);
1875 
1876 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1877 	if (IS_ERR(filp)) {
1878 		status = PTR_ERR(filp);
1879 		goto out;
1880 	}
1881 	transport->file = filp;
1882 
1883 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1884 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1885 
1886 	status = xs_local_finish_connecting(xprt, sock);
1887 	trace_rpc_socket_connect(xprt, sock, status);
1888 	switch (status) {
1889 	case 0:
1890 		dprintk("RPC:       xprt %p connected to %s\n",
1891 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1892 		xprt->stat.connect_count++;
1893 		xprt->stat.connect_time += (long)jiffies -
1894 					   xprt->stat.connect_start;
1895 		xprt_set_connected(xprt);
1896 	case -ENOBUFS:
1897 		break;
1898 	case -ENOENT:
1899 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1900 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1901 		break;
1902 	case -ECONNREFUSED:
1903 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1904 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1905 		break;
1906 	default:
1907 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1908 				__func__, -status,
1909 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1910 	}
1911 
1912 out:
1913 	xprt_clear_connecting(xprt);
1914 	xprt_wake_pending_tasks(xprt, status);
1915 	return status;
1916 }
1917 
xs_local_connect(struct rpc_xprt * xprt,struct rpc_task * task)1918 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1919 {
1920 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1921 	int ret;
1922 
1923 	 if (RPC_IS_ASYNC(task)) {
1924 		/*
1925 		 * We want the AF_LOCAL connect to be resolved in the
1926 		 * filesystem namespace of the process making the rpc
1927 		 * call.  Thus we connect synchronously.
1928 		 *
1929 		 * If we want to support asynchronous AF_LOCAL calls,
1930 		 * we'll need to figure out how to pass a namespace to
1931 		 * connect.
1932 		 */
1933 		task->tk_rpc_status = -ENOTCONN;
1934 		rpc_exit(task, -ENOTCONN);
1935 		return;
1936 	}
1937 	ret = xs_local_setup_socket(transport);
1938 	if (ret && !RPC_IS_SOFTCONN(task))
1939 		msleep_interruptible(15000);
1940 }
1941 
1942 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1943 /*
1944  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1945  * know that we have exclusive access to the socket), to guard against
1946  * races with xs_reset_transport.
1947  */
xs_set_memalloc(struct rpc_xprt * xprt)1948 static void xs_set_memalloc(struct rpc_xprt *xprt)
1949 {
1950 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1951 			xprt);
1952 
1953 	/*
1954 	 * If there's no sock, then we have nothing to set. The
1955 	 * reconnecting process will get it for us.
1956 	 */
1957 	if (!transport->inet)
1958 		return;
1959 	if (atomic_read(&xprt->swapper))
1960 		sk_set_memalloc(transport->inet);
1961 }
1962 
1963 /**
1964  * xs_enable_swap - Tag this transport as being used for swap.
1965  * @xprt: transport to tag
1966  *
1967  * Take a reference to this transport on behalf of the rpc_clnt, and
1968  * optionally mark it for swapping if it wasn't already.
1969  */
1970 static int
xs_enable_swap(struct rpc_xprt * xprt)1971 xs_enable_swap(struct rpc_xprt *xprt)
1972 {
1973 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1974 
1975 	if (atomic_inc_return(&xprt->swapper) != 1)
1976 		return 0;
1977 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1978 		return -ERESTARTSYS;
1979 	if (xs->inet)
1980 		sk_set_memalloc(xs->inet);
1981 	xprt_release_xprt(xprt, NULL);
1982 	return 0;
1983 }
1984 
1985 /**
1986  * xs_disable_swap - Untag this transport as being used for swap.
1987  * @xprt: transport to tag
1988  *
1989  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1990  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1991  */
1992 static void
xs_disable_swap(struct rpc_xprt * xprt)1993 xs_disable_swap(struct rpc_xprt *xprt)
1994 {
1995 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1996 
1997 	if (!atomic_dec_and_test(&xprt->swapper))
1998 		return;
1999 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2000 		return;
2001 	if (xs->inet)
2002 		sk_clear_memalloc(xs->inet);
2003 	xprt_release_xprt(xprt, NULL);
2004 }
2005 #else
xs_set_memalloc(struct rpc_xprt * xprt)2006 static void xs_set_memalloc(struct rpc_xprt *xprt)
2007 {
2008 }
2009 
2010 static int
xs_enable_swap(struct rpc_xprt * xprt)2011 xs_enable_swap(struct rpc_xprt *xprt)
2012 {
2013 	return -EINVAL;
2014 }
2015 
2016 static void
xs_disable_swap(struct rpc_xprt * xprt)2017 xs_disable_swap(struct rpc_xprt *xprt)
2018 {
2019 }
2020 #endif
2021 
xs_udp_finish_connecting(struct rpc_xprt * xprt,struct socket * sock)2022 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2023 {
2024 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2025 
2026 	if (!transport->inet) {
2027 		struct sock *sk = sock->sk;
2028 
2029 		write_lock_bh(&sk->sk_callback_lock);
2030 
2031 		xs_save_old_callbacks(transport, sk);
2032 
2033 		sk->sk_user_data = xprt;
2034 		sk->sk_data_ready = xs_data_ready;
2035 		sk->sk_write_space = xs_udp_write_space;
2036 		sock_set_flag(sk, SOCK_FASYNC);
2037 
2038 		xprt_set_connected(xprt);
2039 
2040 		/* Reset to new socket */
2041 		transport->sock = sock;
2042 		transport->inet = sk;
2043 
2044 		xs_set_memalloc(xprt);
2045 
2046 		write_unlock_bh(&sk->sk_callback_lock);
2047 	}
2048 	xs_udp_do_set_buffer_size(xprt);
2049 
2050 	xprt->stat.connect_start = jiffies;
2051 }
2052 
xs_udp_setup_socket(struct work_struct * work)2053 static void xs_udp_setup_socket(struct work_struct *work)
2054 {
2055 	struct sock_xprt *transport =
2056 		container_of(work, struct sock_xprt, connect_worker.work);
2057 	struct rpc_xprt *xprt = &transport->xprt;
2058 	struct socket *sock;
2059 	int status = -EIO;
2060 
2061 	sock = xs_create_sock(xprt, transport,
2062 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2063 			IPPROTO_UDP, false);
2064 	if (IS_ERR(sock))
2065 		goto out;
2066 
2067 	dprintk("RPC:       worker connecting xprt %p via %s to "
2068 				"%s (port %s)\n", xprt,
2069 			xprt->address_strings[RPC_DISPLAY_PROTO],
2070 			xprt->address_strings[RPC_DISPLAY_ADDR],
2071 			xprt->address_strings[RPC_DISPLAY_PORT]);
2072 
2073 	xs_udp_finish_connecting(xprt, sock);
2074 	trace_rpc_socket_connect(xprt, sock, 0);
2075 	status = 0;
2076 out:
2077 	xprt_clear_connecting(xprt);
2078 	xprt_unlock_connect(xprt, transport);
2079 	xprt_wake_pending_tasks(xprt, status);
2080 }
2081 
2082 /**
2083  * xs_tcp_shutdown - gracefully shut down a TCP socket
2084  * @xprt: transport
2085  *
2086  * Initiates a graceful shutdown of the TCP socket by calling the
2087  * equivalent of shutdown(SHUT_RDWR);
2088  */
xs_tcp_shutdown(struct rpc_xprt * xprt)2089 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2090 {
2091 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2092 	struct socket *sock = transport->sock;
2093 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2094 
2095 	if (sock == NULL)
2096 		return;
2097 	switch (skst) {
2098 	default:
2099 		kernel_sock_shutdown(sock, SHUT_RDWR);
2100 		trace_rpc_socket_shutdown(xprt, sock);
2101 		break;
2102 	case TCP_CLOSE:
2103 	case TCP_TIME_WAIT:
2104 		xs_reset_transport(transport);
2105 	}
2106 }
2107 
xs_tcp_set_socket_timeouts(struct rpc_xprt * xprt,struct socket * sock)2108 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2109 		struct socket *sock)
2110 {
2111 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2112 	unsigned int keepidle;
2113 	unsigned int keepcnt;
2114 	unsigned int timeo;
2115 
2116 	spin_lock(&xprt->transport_lock);
2117 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2118 	keepcnt = xprt->timeout->to_retries + 1;
2119 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2120 		(xprt->timeout->to_retries + 1);
2121 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2122 	spin_unlock(&xprt->transport_lock);
2123 
2124 	/* TCP Keepalive options */
2125 	sock_set_keepalive(sock->sk);
2126 	tcp_sock_set_keepidle(sock->sk, keepidle);
2127 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2128 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2129 
2130 	/* TCP user timeout (see RFC5482) */
2131 	tcp_sock_set_user_timeout(sock->sk, timeo);
2132 }
2133 
xs_tcp_set_connect_timeout(struct rpc_xprt * xprt,unsigned long connect_timeout,unsigned long reconnect_timeout)2134 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2135 		unsigned long connect_timeout,
2136 		unsigned long reconnect_timeout)
2137 {
2138 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2139 	struct rpc_timeout to;
2140 	unsigned long initval;
2141 
2142 	spin_lock(&xprt->transport_lock);
2143 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2144 		xprt->max_reconnect_timeout = reconnect_timeout;
2145 	if (connect_timeout < xprt->connect_timeout) {
2146 		memcpy(&to, xprt->timeout, sizeof(to));
2147 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2148 		/* Arbitrary lower limit */
2149 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2150 			initval = XS_TCP_INIT_REEST_TO << 1;
2151 		to.to_initval = initval;
2152 		to.to_maxval = initval;
2153 		memcpy(&transport->tcp_timeout, &to,
2154 				sizeof(transport->tcp_timeout));
2155 		xprt->timeout = &transport->tcp_timeout;
2156 		xprt->connect_timeout = connect_timeout;
2157 	}
2158 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2159 	spin_unlock(&xprt->transport_lock);
2160 }
2161 
xs_tcp_finish_connecting(struct rpc_xprt * xprt,struct socket * sock)2162 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2163 {
2164 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2165 	int ret = -ENOTCONN;
2166 
2167 	if (!transport->inet) {
2168 		struct sock *sk = sock->sk;
2169 
2170 		/* Avoid temporary address, they are bad for long-lived
2171 		 * connections such as NFS mounts.
2172 		 * RFC4941, section 3.6 suggests that:
2173 		 *    Individual applications, which have specific
2174 		 *    knowledge about the normal duration of connections,
2175 		 *    MAY override this as appropriate.
2176 		 */
2177 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2178 			ip6_sock_set_addr_preferences(sk,
2179 				IPV6_PREFER_SRC_PUBLIC);
2180 		}
2181 
2182 		xs_tcp_set_socket_timeouts(xprt, sock);
2183 
2184 		write_lock_bh(&sk->sk_callback_lock);
2185 
2186 		xs_save_old_callbacks(transport, sk);
2187 
2188 		sk->sk_user_data = xprt;
2189 		sk->sk_data_ready = xs_data_ready;
2190 		sk->sk_state_change = xs_tcp_state_change;
2191 		sk->sk_write_space = xs_tcp_write_space;
2192 		sock_set_flag(sk, SOCK_FASYNC);
2193 		sk->sk_error_report = xs_error_report;
2194 
2195 		/* socket options */
2196 		sock_reset_flag(sk, SOCK_LINGER);
2197 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2198 
2199 		xprt_clear_connected(xprt);
2200 
2201 		/* Reset to new socket */
2202 		transport->sock = sock;
2203 		transport->inet = sk;
2204 
2205 		write_unlock_bh(&sk->sk_callback_lock);
2206 	}
2207 
2208 	if (!xprt_bound(xprt))
2209 		goto out;
2210 
2211 	xs_set_memalloc(xprt);
2212 
2213 	xs_stream_start_connect(transport);
2214 
2215 	/* Tell the socket layer to start connecting... */
2216 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2217 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2218 	switch (ret) {
2219 	case 0:
2220 		xs_set_srcport(transport, sock);
2221 		fallthrough;
2222 	case -EINPROGRESS:
2223 		/* SYN_SENT! */
2224 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2225 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2226 		break;
2227 	case -EADDRNOTAVAIL:
2228 		/* Source port number is unavailable. Try a new one! */
2229 		transport->srcport = 0;
2230 	}
2231 out:
2232 	return ret;
2233 }
2234 
2235 /**
2236  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2237  * @work: queued work item
2238  *
2239  * Invoked by a work queue tasklet.
2240  */
xs_tcp_setup_socket(struct work_struct * work)2241 static void xs_tcp_setup_socket(struct work_struct *work)
2242 {
2243 	struct sock_xprt *transport =
2244 		container_of(work, struct sock_xprt, connect_worker.work);
2245 	struct socket *sock = transport->sock;
2246 	struct rpc_xprt *xprt = &transport->xprt;
2247 	int status = -EIO;
2248 
2249 	if (!sock) {
2250 		sock = xs_create_sock(xprt, transport,
2251 				xs_addr(xprt)->sa_family, SOCK_STREAM,
2252 				IPPROTO_TCP, true);
2253 		if (IS_ERR(sock)) {
2254 			status = PTR_ERR(sock);
2255 			goto out;
2256 		}
2257 	}
2258 
2259 	dprintk("RPC:       worker connecting xprt %p via %s to "
2260 				"%s (port %s)\n", xprt,
2261 			xprt->address_strings[RPC_DISPLAY_PROTO],
2262 			xprt->address_strings[RPC_DISPLAY_ADDR],
2263 			xprt->address_strings[RPC_DISPLAY_PORT]);
2264 
2265 	status = xs_tcp_finish_connecting(xprt, sock);
2266 	trace_rpc_socket_connect(xprt, sock, status);
2267 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2268 			xprt, -status, xprt_connected(xprt),
2269 			sock->sk->sk_state);
2270 	switch (status) {
2271 	default:
2272 		printk("%s: connect returned unhandled error %d\n",
2273 			__func__, status);
2274 		fallthrough;
2275 	case -EADDRNOTAVAIL:
2276 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2277 		 * and retry
2278 		 */
2279 		xs_tcp_force_close(xprt);
2280 		break;
2281 	case 0:
2282 	case -EINPROGRESS:
2283 	case -EALREADY:
2284 		xprt_unlock_connect(xprt, transport);
2285 		return;
2286 	case -EINVAL:
2287 		/* Happens, for instance, if the user specified a link
2288 		 * local IPv6 address without a scope-id.
2289 		 */
2290 	case -ECONNREFUSED:
2291 	case -ECONNRESET:
2292 	case -ENETDOWN:
2293 	case -ENETUNREACH:
2294 	case -EHOSTUNREACH:
2295 	case -EADDRINUSE:
2296 	case -ENOBUFS:
2297 		/*
2298 		 * xs_tcp_force_close() wakes tasks with -EIO.
2299 		 * We need to wake them first to ensure the
2300 		 * correct error code.
2301 		 */
2302 		xprt_wake_pending_tasks(xprt, status);
2303 		xs_tcp_force_close(xprt);
2304 		goto out;
2305 	}
2306 	status = -EAGAIN;
2307 out:
2308 	xprt_clear_connecting(xprt);
2309 	xprt_unlock_connect(xprt, transport);
2310 	xprt_wake_pending_tasks(xprt, status);
2311 }
2312 
2313 /**
2314  * xs_connect - connect a socket to a remote endpoint
2315  * @xprt: pointer to transport structure
2316  * @task: address of RPC task that manages state of connect request
2317  *
2318  * TCP: If the remote end dropped the connection, delay reconnecting.
2319  *
2320  * UDP socket connects are synchronous, but we use a work queue anyway
2321  * to guarantee that even unprivileged user processes can set up a
2322  * socket on a privileged port.
2323  *
2324  * If a UDP socket connect fails, the delay behavior here prevents
2325  * retry floods (hard mounts).
2326  */
xs_connect(struct rpc_xprt * xprt,struct rpc_task * task)2327 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2328 {
2329 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2330 	unsigned long delay = 0;
2331 
2332 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2333 
2334 	if (transport->sock != NULL) {
2335 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2336 				"seconds\n",
2337 				xprt, xprt->reestablish_timeout / HZ);
2338 
2339 		/* Start by resetting any existing state */
2340 		xs_reset_transport(transport);
2341 
2342 		delay = xprt_reconnect_delay(xprt);
2343 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2344 
2345 	} else
2346 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2347 
2348 	queue_delayed_work(xprtiod_workqueue,
2349 			&transport->connect_worker,
2350 			delay);
2351 }
2352 
xs_wake_disconnect(struct sock_xprt * transport)2353 static void xs_wake_disconnect(struct sock_xprt *transport)
2354 {
2355 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2356 		xs_tcp_force_close(&transport->xprt);
2357 }
2358 
xs_wake_write(struct sock_xprt * transport)2359 static void xs_wake_write(struct sock_xprt *transport)
2360 {
2361 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2362 		xprt_write_space(&transport->xprt);
2363 }
2364 
xs_wake_error(struct sock_xprt * transport)2365 static void xs_wake_error(struct sock_xprt *transport)
2366 {
2367 	int sockerr;
2368 
2369 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2370 		return;
2371 	mutex_lock(&transport->recv_mutex);
2372 	if (transport->sock == NULL)
2373 		goto out;
2374 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2375 		goto out;
2376 	sockerr = xchg(&transport->xprt_err, 0);
2377 	if (sockerr < 0)
2378 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2379 out:
2380 	mutex_unlock(&transport->recv_mutex);
2381 }
2382 
xs_wake_pending(struct sock_xprt * transport)2383 static void xs_wake_pending(struct sock_xprt *transport)
2384 {
2385 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2386 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2387 }
2388 
xs_error_handle(struct work_struct * work)2389 static void xs_error_handle(struct work_struct *work)
2390 {
2391 	struct sock_xprt *transport = container_of(work,
2392 			struct sock_xprt, error_worker);
2393 
2394 	xs_wake_disconnect(transport);
2395 	xs_wake_write(transport);
2396 	xs_wake_error(transport);
2397 	xs_wake_pending(transport);
2398 }
2399 
2400 /**
2401  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2402  * @xprt: rpc_xprt struct containing statistics
2403  * @seq: output file
2404  *
2405  */
xs_local_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)2406 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2407 {
2408 	long idle_time = 0;
2409 
2410 	if (xprt_connected(xprt))
2411 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2412 
2413 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2414 			"%llu %llu %lu %llu %llu\n",
2415 			xprt->stat.bind_count,
2416 			xprt->stat.connect_count,
2417 			xprt->stat.connect_time / HZ,
2418 			idle_time,
2419 			xprt->stat.sends,
2420 			xprt->stat.recvs,
2421 			xprt->stat.bad_xids,
2422 			xprt->stat.req_u,
2423 			xprt->stat.bklog_u,
2424 			xprt->stat.max_slots,
2425 			xprt->stat.sending_u,
2426 			xprt->stat.pending_u);
2427 }
2428 
2429 /**
2430  * xs_udp_print_stats - display UDP socket-specifc stats
2431  * @xprt: rpc_xprt struct containing statistics
2432  * @seq: output file
2433  *
2434  */
xs_udp_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)2435 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2436 {
2437 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2438 
2439 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2440 			"%lu %llu %llu\n",
2441 			transport->srcport,
2442 			xprt->stat.bind_count,
2443 			xprt->stat.sends,
2444 			xprt->stat.recvs,
2445 			xprt->stat.bad_xids,
2446 			xprt->stat.req_u,
2447 			xprt->stat.bklog_u,
2448 			xprt->stat.max_slots,
2449 			xprt->stat.sending_u,
2450 			xprt->stat.pending_u);
2451 }
2452 
2453 /**
2454  * xs_tcp_print_stats - display TCP socket-specifc stats
2455  * @xprt: rpc_xprt struct containing statistics
2456  * @seq: output file
2457  *
2458  */
xs_tcp_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)2459 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2460 {
2461 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2462 	long idle_time = 0;
2463 
2464 	if (xprt_connected(xprt))
2465 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2466 
2467 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2468 			"%llu %llu %lu %llu %llu\n",
2469 			transport->srcport,
2470 			xprt->stat.bind_count,
2471 			xprt->stat.connect_count,
2472 			xprt->stat.connect_time / HZ,
2473 			idle_time,
2474 			xprt->stat.sends,
2475 			xprt->stat.recvs,
2476 			xprt->stat.bad_xids,
2477 			xprt->stat.req_u,
2478 			xprt->stat.bklog_u,
2479 			xprt->stat.max_slots,
2480 			xprt->stat.sending_u,
2481 			xprt->stat.pending_u);
2482 }
2483 
2484 /*
2485  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2486  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2487  * to use the server side send routines.
2488  */
bc_malloc(struct rpc_task * task)2489 static int bc_malloc(struct rpc_task *task)
2490 {
2491 	struct rpc_rqst *rqst = task->tk_rqstp;
2492 	size_t size = rqst->rq_callsize;
2493 	struct page *page;
2494 	struct rpc_buffer *buf;
2495 
2496 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2497 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2498 			  size);
2499 		return -EINVAL;
2500 	}
2501 
2502 	page = alloc_page(GFP_KERNEL);
2503 	if (!page)
2504 		return -ENOMEM;
2505 
2506 	buf = page_address(page);
2507 	buf->len = PAGE_SIZE;
2508 
2509 	rqst->rq_buffer = buf->data;
2510 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2511 	return 0;
2512 }
2513 
2514 /*
2515  * Free the space allocated in the bc_alloc routine
2516  */
bc_free(struct rpc_task * task)2517 static void bc_free(struct rpc_task *task)
2518 {
2519 	void *buffer = task->tk_rqstp->rq_buffer;
2520 	struct rpc_buffer *buf;
2521 
2522 	buf = container_of(buffer, struct rpc_buffer, data);
2523 	free_page((unsigned long)buf);
2524 }
2525 
bc_sendto(struct rpc_rqst * req)2526 static int bc_sendto(struct rpc_rqst *req)
2527 {
2528 	struct xdr_buf *xdr = &req->rq_snd_buf;
2529 	struct sock_xprt *transport =
2530 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2531 	struct msghdr msg = {
2532 		.msg_flags	= 0,
2533 	};
2534 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2535 					 (u32)xdr->len);
2536 	unsigned int sent = 0;
2537 	int err;
2538 
2539 	req->rq_xtime = ktime_get();
2540 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2541 	xdr_free_bvec(xdr);
2542 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2543 		return -EAGAIN;
2544 	return sent;
2545 }
2546 
2547 /**
2548  * bc_send_request - Send a backchannel Call on a TCP socket
2549  * @req: rpc_rqst containing Call message to be sent
2550  *
2551  * xpt_mutex ensures @rqstp's whole message is written to the socket
2552  * without interruption.
2553  *
2554  * Return values:
2555  *   %0 if the message was sent successfully
2556  *   %ENOTCONN if the message was not sent
2557  */
bc_send_request(struct rpc_rqst * req)2558 static int bc_send_request(struct rpc_rqst *req)
2559 {
2560 	struct svc_xprt	*xprt;
2561 	int len;
2562 
2563 	/*
2564 	 * Get the server socket associated with this callback xprt
2565 	 */
2566 	xprt = req->rq_xprt->bc_xprt;
2567 
2568 	/*
2569 	 * Grab the mutex to serialize data as the connection is shared
2570 	 * with the fore channel
2571 	 */
2572 	mutex_lock(&xprt->xpt_mutex);
2573 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2574 		len = -ENOTCONN;
2575 	else
2576 		len = bc_sendto(req);
2577 	mutex_unlock(&xprt->xpt_mutex);
2578 
2579 	if (len > 0)
2580 		len = 0;
2581 
2582 	return len;
2583 }
2584 
2585 /*
2586  * The close routine. Since this is client initiated, we do nothing
2587  */
2588 
bc_close(struct rpc_xprt * xprt)2589 static void bc_close(struct rpc_xprt *xprt)
2590 {
2591 	xprt_disconnect_done(xprt);
2592 }
2593 
2594 /*
2595  * The xprt destroy routine. Again, because this connection is client
2596  * initiated, we do nothing
2597  */
2598 
bc_destroy(struct rpc_xprt * xprt)2599 static void bc_destroy(struct rpc_xprt *xprt)
2600 {
2601 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2602 
2603 	xs_xprt_free(xprt);
2604 	module_put(THIS_MODULE);
2605 }
2606 
2607 static const struct rpc_xprt_ops xs_local_ops = {
2608 	.reserve_xprt		= xprt_reserve_xprt,
2609 	.release_xprt		= xprt_release_xprt,
2610 	.alloc_slot		= xprt_alloc_slot,
2611 	.free_slot		= xprt_free_slot,
2612 	.rpcbind		= xs_local_rpcbind,
2613 	.set_port		= xs_local_set_port,
2614 	.connect		= xs_local_connect,
2615 	.buf_alloc		= rpc_malloc,
2616 	.buf_free		= rpc_free,
2617 	.prepare_request	= xs_stream_prepare_request,
2618 	.send_request		= xs_local_send_request,
2619 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2620 	.close			= xs_close,
2621 	.destroy		= xs_destroy,
2622 	.print_stats		= xs_local_print_stats,
2623 	.enable_swap		= xs_enable_swap,
2624 	.disable_swap		= xs_disable_swap,
2625 };
2626 
2627 static const struct rpc_xprt_ops xs_udp_ops = {
2628 	.set_buffer_size	= xs_udp_set_buffer_size,
2629 	.reserve_xprt		= xprt_reserve_xprt_cong,
2630 	.release_xprt		= xprt_release_xprt_cong,
2631 	.alloc_slot		= xprt_alloc_slot,
2632 	.free_slot		= xprt_free_slot,
2633 	.rpcbind		= rpcb_getport_async,
2634 	.set_port		= xs_set_port,
2635 	.connect		= xs_connect,
2636 	.buf_alloc		= rpc_malloc,
2637 	.buf_free		= rpc_free,
2638 	.send_request		= xs_udp_send_request,
2639 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2640 	.timer			= xs_udp_timer,
2641 	.release_request	= xprt_release_rqst_cong,
2642 	.close			= xs_close,
2643 	.destroy		= xs_destroy,
2644 	.print_stats		= xs_udp_print_stats,
2645 	.enable_swap		= xs_enable_swap,
2646 	.disable_swap		= xs_disable_swap,
2647 	.inject_disconnect	= xs_inject_disconnect,
2648 };
2649 
2650 static const struct rpc_xprt_ops xs_tcp_ops = {
2651 	.reserve_xprt		= xprt_reserve_xprt,
2652 	.release_xprt		= xprt_release_xprt,
2653 	.alloc_slot		= xprt_alloc_slot,
2654 	.free_slot		= xprt_free_slot,
2655 	.rpcbind		= rpcb_getport_async,
2656 	.set_port		= xs_set_port,
2657 	.connect		= xs_connect,
2658 	.buf_alloc		= rpc_malloc,
2659 	.buf_free		= rpc_free,
2660 	.prepare_request	= xs_stream_prepare_request,
2661 	.send_request		= xs_tcp_send_request,
2662 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2663 	.close			= xs_tcp_shutdown,
2664 	.destroy		= xs_destroy,
2665 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2666 	.print_stats		= xs_tcp_print_stats,
2667 	.enable_swap		= xs_enable_swap,
2668 	.disable_swap		= xs_disable_swap,
2669 	.inject_disconnect	= xs_inject_disconnect,
2670 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2671 	.bc_setup		= xprt_setup_bc,
2672 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2673 	.bc_num_slots		= xprt_bc_max_slots,
2674 	.bc_free_rqst		= xprt_free_bc_rqst,
2675 	.bc_destroy		= xprt_destroy_bc,
2676 #endif
2677 };
2678 
2679 /*
2680  * The rpc_xprt_ops for the server backchannel
2681  */
2682 
2683 static const struct rpc_xprt_ops bc_tcp_ops = {
2684 	.reserve_xprt		= xprt_reserve_xprt,
2685 	.release_xprt		= xprt_release_xprt,
2686 	.alloc_slot		= xprt_alloc_slot,
2687 	.free_slot		= xprt_free_slot,
2688 	.buf_alloc		= bc_malloc,
2689 	.buf_free		= bc_free,
2690 	.send_request		= bc_send_request,
2691 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2692 	.close			= bc_close,
2693 	.destroy		= bc_destroy,
2694 	.print_stats		= xs_tcp_print_stats,
2695 	.enable_swap		= xs_enable_swap,
2696 	.disable_swap		= xs_disable_swap,
2697 	.inject_disconnect	= xs_inject_disconnect,
2698 };
2699 
xs_init_anyaddr(const int family,struct sockaddr * sap)2700 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2701 {
2702 	static const struct sockaddr_in sin = {
2703 		.sin_family		= AF_INET,
2704 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2705 	};
2706 	static const struct sockaddr_in6 sin6 = {
2707 		.sin6_family		= AF_INET6,
2708 		.sin6_addr		= IN6ADDR_ANY_INIT,
2709 	};
2710 
2711 	switch (family) {
2712 	case AF_LOCAL:
2713 		break;
2714 	case AF_INET:
2715 		memcpy(sap, &sin, sizeof(sin));
2716 		break;
2717 	case AF_INET6:
2718 		memcpy(sap, &sin6, sizeof(sin6));
2719 		break;
2720 	default:
2721 		dprintk("RPC:       %s: Bad address family\n", __func__);
2722 		return -EAFNOSUPPORT;
2723 	}
2724 	return 0;
2725 }
2726 
xs_setup_xprt(struct xprt_create * args,unsigned int slot_table_size,unsigned int max_slot_table_size)2727 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2728 				      unsigned int slot_table_size,
2729 				      unsigned int max_slot_table_size)
2730 {
2731 	struct rpc_xprt *xprt;
2732 	struct sock_xprt *new;
2733 
2734 	if (args->addrlen > sizeof(xprt->addr)) {
2735 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2736 		return ERR_PTR(-EBADF);
2737 	}
2738 
2739 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2740 			max_slot_table_size);
2741 	if (xprt == NULL) {
2742 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2743 				"rpc_xprt\n");
2744 		return ERR_PTR(-ENOMEM);
2745 	}
2746 
2747 	new = container_of(xprt, struct sock_xprt, xprt);
2748 	mutex_init(&new->recv_mutex);
2749 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2750 	xprt->addrlen = args->addrlen;
2751 	if (args->srcaddr)
2752 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2753 	else {
2754 		int err;
2755 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2756 					(struct sockaddr *)&new->srcaddr);
2757 		if (err != 0) {
2758 			xprt_free(xprt);
2759 			return ERR_PTR(err);
2760 		}
2761 	}
2762 
2763 	return xprt;
2764 }
2765 
2766 static const struct rpc_timeout xs_local_default_timeout = {
2767 	.to_initval = 10 * HZ,
2768 	.to_maxval = 10 * HZ,
2769 	.to_retries = 2,
2770 };
2771 
2772 /**
2773  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2774  * @args: rpc transport creation arguments
2775  *
2776  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2777  */
xs_setup_local(struct xprt_create * args)2778 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2779 {
2780 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2781 	struct sock_xprt *transport;
2782 	struct rpc_xprt *xprt;
2783 	struct rpc_xprt *ret;
2784 
2785 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2786 			xprt_max_tcp_slot_table_entries);
2787 	if (IS_ERR(xprt))
2788 		return xprt;
2789 	transport = container_of(xprt, struct sock_xprt, xprt);
2790 
2791 	xprt->prot = 0;
2792 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2793 
2794 	xprt->bind_timeout = XS_BIND_TO;
2795 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2796 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2797 
2798 	xprt->ops = &xs_local_ops;
2799 	xprt->timeout = &xs_local_default_timeout;
2800 
2801 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2802 	INIT_WORK(&transport->error_worker, xs_error_handle);
2803 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2804 
2805 	switch (sun->sun_family) {
2806 	case AF_LOCAL:
2807 		if (sun->sun_path[0] != '/') {
2808 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2809 					sun->sun_path);
2810 			ret = ERR_PTR(-EINVAL);
2811 			goto out_err;
2812 		}
2813 		xprt_set_bound(xprt);
2814 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2815 		ret = ERR_PTR(xs_local_setup_socket(transport));
2816 		if (ret)
2817 			goto out_err;
2818 		break;
2819 	default:
2820 		ret = ERR_PTR(-EAFNOSUPPORT);
2821 		goto out_err;
2822 	}
2823 
2824 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2825 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2826 
2827 	if (try_module_get(THIS_MODULE))
2828 		return xprt;
2829 	ret = ERR_PTR(-EINVAL);
2830 out_err:
2831 	xs_xprt_free(xprt);
2832 	return ret;
2833 }
2834 
2835 static const struct rpc_timeout xs_udp_default_timeout = {
2836 	.to_initval = 5 * HZ,
2837 	.to_maxval = 30 * HZ,
2838 	.to_increment = 5 * HZ,
2839 	.to_retries = 5,
2840 };
2841 
2842 /**
2843  * xs_setup_udp - Set up transport to use a UDP socket
2844  * @args: rpc transport creation arguments
2845  *
2846  */
xs_setup_udp(struct xprt_create * args)2847 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2848 {
2849 	struct sockaddr *addr = args->dstaddr;
2850 	struct rpc_xprt *xprt;
2851 	struct sock_xprt *transport;
2852 	struct rpc_xprt *ret;
2853 
2854 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2855 			xprt_udp_slot_table_entries);
2856 	if (IS_ERR(xprt))
2857 		return xprt;
2858 	transport = container_of(xprt, struct sock_xprt, xprt);
2859 
2860 	xprt->prot = IPPROTO_UDP;
2861 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2862 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2863 
2864 	xprt->bind_timeout = XS_BIND_TO;
2865 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2866 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2867 
2868 	xprt->ops = &xs_udp_ops;
2869 
2870 	xprt->timeout = &xs_udp_default_timeout;
2871 
2872 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2873 	INIT_WORK(&transport->error_worker, xs_error_handle);
2874 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2875 
2876 	switch (addr->sa_family) {
2877 	case AF_INET:
2878 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2879 			xprt_set_bound(xprt);
2880 
2881 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2882 		break;
2883 	case AF_INET6:
2884 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2885 			xprt_set_bound(xprt);
2886 
2887 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2888 		break;
2889 	default:
2890 		ret = ERR_PTR(-EAFNOSUPPORT);
2891 		goto out_err;
2892 	}
2893 
2894 	if (xprt_bound(xprt))
2895 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2896 				xprt->address_strings[RPC_DISPLAY_ADDR],
2897 				xprt->address_strings[RPC_DISPLAY_PORT],
2898 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2899 	else
2900 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2901 				xprt->address_strings[RPC_DISPLAY_ADDR],
2902 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2903 
2904 	if (try_module_get(THIS_MODULE))
2905 		return xprt;
2906 	ret = ERR_PTR(-EINVAL);
2907 out_err:
2908 	xs_xprt_free(xprt);
2909 	return ret;
2910 }
2911 
2912 static const struct rpc_timeout xs_tcp_default_timeout = {
2913 	.to_initval = 60 * HZ,
2914 	.to_maxval = 60 * HZ,
2915 	.to_retries = 2,
2916 };
2917 
2918 /**
2919  * xs_setup_tcp - Set up transport to use a TCP socket
2920  * @args: rpc transport creation arguments
2921  *
2922  */
xs_setup_tcp(struct xprt_create * args)2923 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2924 {
2925 	struct sockaddr *addr = args->dstaddr;
2926 	struct rpc_xprt *xprt;
2927 	struct sock_xprt *transport;
2928 	struct rpc_xprt *ret;
2929 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2930 
2931 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2932 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2933 
2934 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2935 			max_slot_table_size);
2936 	if (IS_ERR(xprt))
2937 		return xprt;
2938 	transport = container_of(xprt, struct sock_xprt, xprt);
2939 
2940 	xprt->prot = IPPROTO_TCP;
2941 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2942 
2943 	xprt->bind_timeout = XS_BIND_TO;
2944 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2945 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2946 
2947 	xprt->ops = &xs_tcp_ops;
2948 	xprt->timeout = &xs_tcp_default_timeout;
2949 
2950 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2951 	xprt->connect_timeout = xprt->timeout->to_initval *
2952 		(xprt->timeout->to_retries + 1);
2953 
2954 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2955 	INIT_WORK(&transport->error_worker, xs_error_handle);
2956 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2957 
2958 	switch (addr->sa_family) {
2959 	case AF_INET:
2960 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2961 			xprt_set_bound(xprt);
2962 
2963 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2964 		break;
2965 	case AF_INET6:
2966 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2967 			xprt_set_bound(xprt);
2968 
2969 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2970 		break;
2971 	default:
2972 		ret = ERR_PTR(-EAFNOSUPPORT);
2973 		goto out_err;
2974 	}
2975 
2976 	if (xprt_bound(xprt))
2977 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2978 				xprt->address_strings[RPC_DISPLAY_ADDR],
2979 				xprt->address_strings[RPC_DISPLAY_PORT],
2980 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2981 	else
2982 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2983 				xprt->address_strings[RPC_DISPLAY_ADDR],
2984 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2985 
2986 	if (try_module_get(THIS_MODULE))
2987 		return xprt;
2988 	ret = ERR_PTR(-EINVAL);
2989 out_err:
2990 	xs_xprt_free(xprt);
2991 	return ret;
2992 }
2993 
2994 /**
2995  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2996  * @args: rpc transport creation arguments
2997  *
2998  */
xs_setup_bc_tcp(struct xprt_create * args)2999 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3000 {
3001 	struct sockaddr *addr = args->dstaddr;
3002 	struct rpc_xprt *xprt;
3003 	struct sock_xprt *transport;
3004 	struct svc_sock *bc_sock;
3005 	struct rpc_xprt *ret;
3006 
3007 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3008 			xprt_tcp_slot_table_entries);
3009 	if (IS_ERR(xprt))
3010 		return xprt;
3011 	transport = container_of(xprt, struct sock_xprt, xprt);
3012 
3013 	xprt->prot = IPPROTO_TCP;
3014 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3015 	xprt->timeout = &xs_tcp_default_timeout;
3016 
3017 	/* backchannel */
3018 	xprt_set_bound(xprt);
3019 	xprt->bind_timeout = 0;
3020 	xprt->reestablish_timeout = 0;
3021 	xprt->idle_timeout = 0;
3022 
3023 	xprt->ops = &bc_tcp_ops;
3024 
3025 	switch (addr->sa_family) {
3026 	case AF_INET:
3027 		xs_format_peer_addresses(xprt, "tcp",
3028 					 RPCBIND_NETID_TCP);
3029 		break;
3030 	case AF_INET6:
3031 		xs_format_peer_addresses(xprt, "tcp",
3032 				   RPCBIND_NETID_TCP6);
3033 		break;
3034 	default:
3035 		ret = ERR_PTR(-EAFNOSUPPORT);
3036 		goto out_err;
3037 	}
3038 
3039 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3040 			xprt->address_strings[RPC_DISPLAY_ADDR],
3041 			xprt->address_strings[RPC_DISPLAY_PORT],
3042 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3043 
3044 	/*
3045 	 * Once we've associated a backchannel xprt with a connection,
3046 	 * we want to keep it around as long as the connection lasts,
3047 	 * in case we need to start using it for a backchannel again;
3048 	 * this reference won't be dropped until bc_xprt is destroyed.
3049 	 */
3050 	xprt_get(xprt);
3051 	args->bc_xprt->xpt_bc_xprt = xprt;
3052 	xprt->bc_xprt = args->bc_xprt;
3053 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3054 	transport->sock = bc_sock->sk_sock;
3055 	transport->inet = bc_sock->sk_sk;
3056 
3057 	/*
3058 	 * Since we don't want connections for the backchannel, we set
3059 	 * the xprt status to connected
3060 	 */
3061 	xprt_set_connected(xprt);
3062 
3063 	if (try_module_get(THIS_MODULE))
3064 		return xprt;
3065 
3066 	args->bc_xprt->xpt_bc_xprt = NULL;
3067 	args->bc_xprt->xpt_bc_xps = NULL;
3068 	xprt_put(xprt);
3069 	ret = ERR_PTR(-EINVAL);
3070 out_err:
3071 	xs_xprt_free(xprt);
3072 	return ret;
3073 }
3074 
3075 static struct xprt_class	xs_local_transport = {
3076 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3077 	.name		= "named UNIX socket",
3078 	.owner		= THIS_MODULE,
3079 	.ident		= XPRT_TRANSPORT_LOCAL,
3080 	.setup		= xs_setup_local,
3081 	.netid		= { "" },
3082 };
3083 
3084 static struct xprt_class	xs_udp_transport = {
3085 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3086 	.name		= "udp",
3087 	.owner		= THIS_MODULE,
3088 	.ident		= XPRT_TRANSPORT_UDP,
3089 	.setup		= xs_setup_udp,
3090 	.netid		= { "udp", "udp6", "" },
3091 };
3092 
3093 static struct xprt_class	xs_tcp_transport = {
3094 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3095 	.name		= "tcp",
3096 	.owner		= THIS_MODULE,
3097 	.ident		= XPRT_TRANSPORT_TCP,
3098 	.setup		= xs_setup_tcp,
3099 	.netid		= { "tcp", "tcp6", "" },
3100 };
3101 
3102 static struct xprt_class	xs_bc_tcp_transport = {
3103 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3104 	.name		= "tcp NFSv4.1 backchannel",
3105 	.owner		= THIS_MODULE,
3106 	.ident		= XPRT_TRANSPORT_BC_TCP,
3107 	.setup		= xs_setup_bc_tcp,
3108 	.netid		= { "" },
3109 };
3110 
3111 /**
3112  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3113  *
3114  */
init_socket_xprt(void)3115 int init_socket_xprt(void)
3116 {
3117 	if (!sunrpc_table_header)
3118 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3119 
3120 	xprt_register_transport(&xs_local_transport);
3121 	xprt_register_transport(&xs_udp_transport);
3122 	xprt_register_transport(&xs_tcp_transport);
3123 	xprt_register_transport(&xs_bc_tcp_transport);
3124 
3125 	return 0;
3126 }
3127 
3128 /**
3129  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3130  *
3131  */
cleanup_socket_xprt(void)3132 void cleanup_socket_xprt(void)
3133 {
3134 	if (sunrpc_table_header) {
3135 		unregister_sysctl_table(sunrpc_table_header);
3136 		sunrpc_table_header = NULL;
3137 	}
3138 
3139 	xprt_unregister_transport(&xs_local_transport);
3140 	xprt_unregister_transport(&xs_udp_transport);
3141 	xprt_unregister_transport(&xs_tcp_transport);
3142 	xprt_unregister_transport(&xs_bc_tcp_transport);
3143 }
3144 
param_set_uint_minmax(const char * val,const struct kernel_param * kp,unsigned int min,unsigned int max)3145 static int param_set_uint_minmax(const char *val,
3146 		const struct kernel_param *kp,
3147 		unsigned int min, unsigned int max)
3148 {
3149 	unsigned int num;
3150 	int ret;
3151 
3152 	if (!val)
3153 		return -EINVAL;
3154 	ret = kstrtouint(val, 0, &num);
3155 	if (ret)
3156 		return ret;
3157 	if (num < min || num > max)
3158 		return -EINVAL;
3159 	*((unsigned int *)kp->arg) = num;
3160 	return 0;
3161 }
3162 
param_set_portnr(const char * val,const struct kernel_param * kp)3163 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3164 {
3165 	return param_set_uint_minmax(val, kp,
3166 			RPC_MIN_RESVPORT,
3167 			RPC_MAX_RESVPORT);
3168 }
3169 
3170 static const struct kernel_param_ops param_ops_portnr = {
3171 	.set = param_set_portnr,
3172 	.get = param_get_uint,
3173 };
3174 
3175 #define param_check_portnr(name, p) \
3176 	__param_check(name, p, unsigned int);
3177 
3178 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3179 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3180 
param_set_slot_table_size(const char * val,const struct kernel_param * kp)3181 static int param_set_slot_table_size(const char *val,
3182 				     const struct kernel_param *kp)
3183 {
3184 	return param_set_uint_minmax(val, kp,
3185 			RPC_MIN_SLOT_TABLE,
3186 			RPC_MAX_SLOT_TABLE);
3187 }
3188 
3189 static const struct kernel_param_ops param_ops_slot_table_size = {
3190 	.set = param_set_slot_table_size,
3191 	.get = param_get_uint,
3192 };
3193 
3194 #define param_check_slot_table_size(name, p) \
3195 	__param_check(name, p, unsigned int);
3196 
param_set_max_slot_table_size(const char * val,const struct kernel_param * kp)3197 static int param_set_max_slot_table_size(const char *val,
3198 				     const struct kernel_param *kp)
3199 {
3200 	return param_set_uint_minmax(val, kp,
3201 			RPC_MIN_SLOT_TABLE,
3202 			RPC_MAX_SLOT_TABLE_LIMIT);
3203 }
3204 
3205 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3206 	.set = param_set_max_slot_table_size,
3207 	.get = param_get_uint,
3208 };
3209 
3210 #define param_check_max_slot_table_size(name, p) \
3211 	__param_check(name, p, unsigned int);
3212 
3213 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3214 		   slot_table_size, 0644);
3215 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3216 		   max_slot_table_size, 0644);
3217 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3218 		   slot_table_size, 0644);
3219