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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 static struct xprt_class xs_local_transport;
95 static struct xprt_class xs_udp_transport;
96 static struct xprt_class xs_tcp_transport;
97 static struct xprt_class xs_bc_tcp_transport;
98 
99 /*
100  * FIXME: changing the UDP slot table size should also resize the UDP
101  *        socket buffers for existing UDP transports
102  */
103 static struct ctl_table xs_tunables_table[] = {
104 	{
105 		.procname	= "udp_slot_table_entries",
106 		.data		= &xprt_udp_slot_table_entries,
107 		.maxlen		= sizeof(unsigned int),
108 		.mode		= 0644,
109 		.proc_handler	= proc_dointvec_minmax,
110 		.extra1		= &min_slot_table_size,
111 		.extra2		= &max_slot_table_size
112 	},
113 	{
114 		.procname	= "tcp_slot_table_entries",
115 		.data		= &xprt_tcp_slot_table_entries,
116 		.maxlen		= sizeof(unsigned int),
117 		.mode		= 0644,
118 		.proc_handler	= proc_dointvec_minmax,
119 		.extra1		= &min_slot_table_size,
120 		.extra2		= &max_slot_table_size
121 	},
122 	{
123 		.procname	= "tcp_max_slot_table_entries",
124 		.data		= &xprt_max_tcp_slot_table_entries,
125 		.maxlen		= sizeof(unsigned int),
126 		.mode		= 0644,
127 		.proc_handler	= proc_dointvec_minmax,
128 		.extra1		= &min_slot_table_size,
129 		.extra2		= &max_tcp_slot_table_limit
130 	},
131 	{
132 		.procname	= "min_resvport",
133 		.data		= &xprt_min_resvport,
134 		.maxlen		= sizeof(unsigned int),
135 		.mode		= 0644,
136 		.proc_handler	= proc_dointvec_minmax,
137 		.extra1		= &xprt_min_resvport_limit,
138 		.extra2		= &xprt_max_resvport_limit
139 	},
140 	{
141 		.procname	= "max_resvport",
142 		.data		= &xprt_max_resvport,
143 		.maxlen		= sizeof(unsigned int),
144 		.mode		= 0644,
145 		.proc_handler	= proc_dointvec_minmax,
146 		.extra1		= &xprt_min_resvport_limit,
147 		.extra2		= &xprt_max_resvport_limit
148 	},
149 	{
150 		.procname	= "tcp_fin_timeout",
151 		.data		= &xs_tcp_fin_timeout,
152 		.maxlen		= sizeof(xs_tcp_fin_timeout),
153 		.mode		= 0644,
154 		.proc_handler	= proc_dointvec_jiffies,
155 	},
156 	{ },
157 };
158 
159 static struct ctl_table sunrpc_table[] = {
160 	{
161 		.procname	= "sunrpc",
162 		.mode		= 0555,
163 		.child		= xs_tunables_table
164 	},
165 	{ },
166 };
167 
168 /*
169  * Wait duration for a reply from the RPC portmapper.
170  */
171 #define XS_BIND_TO		(60U * HZ)
172 
173 /*
174  * Delay if a UDP socket connect error occurs.  This is most likely some
175  * kind of resource problem on the local host.
176  */
177 #define XS_UDP_REEST_TO		(2U * HZ)
178 
179 /*
180  * The reestablish timeout allows clients to delay for a bit before attempting
181  * to reconnect to a server that just dropped our connection.
182  *
183  * We implement an exponential backoff when trying to reestablish a TCP
184  * transport connection with the server.  Some servers like to drop a TCP
185  * connection when they are overworked, so we start with a short timeout and
186  * increase over time if the server is down or not responding.
187  */
188 #define XS_TCP_INIT_REEST_TO	(3U * HZ)
189 
190 /*
191  * TCP idle timeout; client drops the transport socket if it is idle
192  * for this long.  Note that we also timeout UDP sockets to prevent
193  * holding port numbers when there is no RPC traffic.
194  */
195 #define XS_IDLE_DISC_TO		(5U * 60 * HZ)
196 
197 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
198 # undef  RPC_DEBUG_DATA
199 # define RPCDBG_FACILITY	RPCDBG_TRANS
200 #endif
201 
202 #ifdef RPC_DEBUG_DATA
xs_pktdump(char * msg,u32 * packet,unsigned int count)203 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
204 {
205 	u8 *buf = (u8 *) packet;
206 	int j;
207 
208 	dprintk("RPC:       %s\n", msg);
209 	for (j = 0; j < count && j < 128; j += 4) {
210 		if (!(j & 31)) {
211 			if (j)
212 				dprintk("\n");
213 			dprintk("0x%04x ", j);
214 		}
215 		dprintk("%02x%02x%02x%02x ",
216 			buf[j], buf[j+1], buf[j+2], buf[j+3]);
217 	}
218 	dprintk("\n");
219 }
220 #else
xs_pktdump(char * msg,u32 * packet,unsigned int count)221 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
222 {
223 	/* NOP */
224 }
225 #endif
226 
xprt_from_sock(struct sock * sk)227 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
228 {
229 	return (struct rpc_xprt *) sk->sk_user_data;
230 }
231 
xs_addr(struct rpc_xprt * xprt)232 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
233 {
234 	return (struct sockaddr *) &xprt->addr;
235 }
236 
xs_addr_un(struct rpc_xprt * xprt)237 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
238 {
239 	return (struct sockaddr_un *) &xprt->addr;
240 }
241 
xs_addr_in(struct rpc_xprt * xprt)242 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
243 {
244 	return (struct sockaddr_in *) &xprt->addr;
245 }
246 
xs_addr_in6(struct rpc_xprt * xprt)247 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
248 {
249 	return (struct sockaddr_in6 *) &xprt->addr;
250 }
251 
xs_format_common_peer_addresses(struct rpc_xprt * xprt)252 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
253 {
254 	struct sockaddr *sap = xs_addr(xprt);
255 	struct sockaddr_in6 *sin6;
256 	struct sockaddr_in *sin;
257 	struct sockaddr_un *sun;
258 	char buf[128];
259 
260 	switch (sap->sa_family) {
261 	case AF_LOCAL:
262 		sun = xs_addr_un(xprt);
263 		strlcpy(buf, sun->sun_path, sizeof(buf));
264 		xprt->address_strings[RPC_DISPLAY_ADDR] =
265 						kstrdup(buf, GFP_KERNEL);
266 		break;
267 	case AF_INET:
268 		(void)rpc_ntop(sap, buf, sizeof(buf));
269 		xprt->address_strings[RPC_DISPLAY_ADDR] =
270 						kstrdup(buf, GFP_KERNEL);
271 		sin = xs_addr_in(xprt);
272 		snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
273 		break;
274 	case AF_INET6:
275 		(void)rpc_ntop(sap, buf, sizeof(buf));
276 		xprt->address_strings[RPC_DISPLAY_ADDR] =
277 						kstrdup(buf, GFP_KERNEL);
278 		sin6 = xs_addr_in6(xprt);
279 		snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
280 		break;
281 	default:
282 		BUG();
283 	}
284 
285 	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
286 }
287 
xs_format_common_peer_ports(struct rpc_xprt * xprt)288 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
289 {
290 	struct sockaddr *sap = xs_addr(xprt);
291 	char buf[128];
292 
293 	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
294 	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
295 
296 	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
297 	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
298 }
299 
xs_format_peer_addresses(struct rpc_xprt * xprt,const char * protocol,const char * netid)300 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
301 				     const char *protocol,
302 				     const char *netid)
303 {
304 	xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
305 	xprt->address_strings[RPC_DISPLAY_NETID] = netid;
306 	xs_format_common_peer_addresses(xprt);
307 	xs_format_common_peer_ports(xprt);
308 }
309 
xs_update_peer_port(struct rpc_xprt * xprt)310 static void xs_update_peer_port(struct rpc_xprt *xprt)
311 {
312 	kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
313 	kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
314 
315 	xs_format_common_peer_ports(xprt);
316 }
317 
xs_free_peer_addresses(struct rpc_xprt * xprt)318 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
319 {
320 	unsigned int i;
321 
322 	for (i = 0; i < RPC_DISPLAY_MAX; i++)
323 		switch (i) {
324 		case RPC_DISPLAY_PROTO:
325 		case RPC_DISPLAY_NETID:
326 			continue;
327 		default:
328 			kfree(xprt->address_strings[i]);
329 		}
330 }
331 
332 static size_t
xs_alloc_sparse_pages(struct xdr_buf * buf,size_t want,gfp_t gfp)333 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
334 {
335 	size_t i,n;
336 
337 	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
338 		return want;
339 	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
340 	for (i = 0; i < n; i++) {
341 		if (buf->pages[i])
342 			continue;
343 		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
344 		if (!buf->pages[i]) {
345 			i *= PAGE_SIZE;
346 			return i > buf->page_base ? i - buf->page_base : 0;
347 		}
348 	}
349 	return want;
350 }
351 
352 static ssize_t
xs_sock_recvmsg(struct socket * sock,struct msghdr * msg,int flags,size_t seek)353 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
354 {
355 	ssize_t ret;
356 	if (seek != 0)
357 		iov_iter_advance(&msg->msg_iter, seek);
358 	ret = sock_recvmsg(sock, msg, flags);
359 	return ret > 0 ? ret + seek : ret;
360 }
361 
362 static ssize_t
xs_read_kvec(struct socket * sock,struct msghdr * msg,int flags,struct kvec * kvec,size_t count,size_t seek)363 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
364 		struct kvec *kvec, size_t count, size_t seek)
365 {
366 	iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
367 	return xs_sock_recvmsg(sock, msg, flags, seek);
368 }
369 
370 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)371 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
372 		struct bio_vec *bvec, unsigned long nr, size_t count,
373 		size_t seek)
374 {
375 	iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
376 	return xs_sock_recvmsg(sock, msg, flags, seek);
377 }
378 
379 static ssize_t
xs_read_discard(struct socket * sock,struct msghdr * msg,int flags,size_t count)380 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
381 		size_t count)
382 {
383 	iov_iter_discard(&msg->msg_iter, READ, count);
384 	return sock_recvmsg(sock, msg, flags);
385 }
386 
387 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
388 static void
xs_flush_bvec(const struct bio_vec * bvec,size_t count,size_t seek)389 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
390 {
391 	struct bvec_iter bi = {
392 		.bi_size = count,
393 	};
394 	struct bio_vec bv;
395 
396 	bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
397 	for_each_bvec(bv, bvec, bi, bi)
398 		flush_dcache_page(bv.bv_page);
399 }
400 #else
401 static inline void
xs_flush_bvec(const struct bio_vec * bvec,size_t count,size_t seek)402 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
403 {
404 }
405 #endif
406 
407 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)408 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
409 		struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
410 {
411 	size_t want, seek_init = seek, offset = 0;
412 	ssize_t ret;
413 
414 	want = min_t(size_t, count, buf->head[0].iov_len);
415 	if (seek < want) {
416 		ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
417 		if (ret <= 0)
418 			goto sock_err;
419 		offset += ret;
420 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
421 			goto out;
422 		if (ret != want)
423 			goto out;
424 		seek = 0;
425 	} else {
426 		seek -= want;
427 		offset += want;
428 	}
429 
430 	want = xs_alloc_sparse_pages(buf,
431 			min_t(size_t, count - offset, buf->page_len),
432 			GFP_KERNEL);
433 	if (seek < want) {
434 		ret = xs_read_bvec(sock, msg, flags, buf->bvec,
435 				xdr_buf_pagecount(buf),
436 				want + buf->page_base,
437 				seek + buf->page_base);
438 		if (ret <= 0)
439 			goto sock_err;
440 		xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
441 		ret -= buf->page_base;
442 		offset += ret;
443 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
444 			goto out;
445 		if (ret != want)
446 			goto out;
447 		seek = 0;
448 	} else {
449 		seek -= want;
450 		offset += want;
451 	}
452 
453 	want = min_t(size_t, count - offset, buf->tail[0].iov_len);
454 	if (seek < want) {
455 		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
456 		if (ret <= 0)
457 			goto sock_err;
458 		offset += ret;
459 		if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
460 			goto out;
461 		if (ret != want)
462 			goto out;
463 	} else if (offset < seek_init)
464 		offset = seek_init;
465 	ret = -EMSGSIZE;
466 out:
467 	*read = offset - seek_init;
468 	return ret;
469 sock_err:
470 	offset += seek;
471 	goto out;
472 }
473 
474 static void
xs_read_header(struct sock_xprt * transport,struct xdr_buf * buf)475 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
476 {
477 	if (!transport->recv.copied) {
478 		if (buf->head[0].iov_len >= transport->recv.offset)
479 			memcpy(buf->head[0].iov_base,
480 					&transport->recv.xid,
481 					transport->recv.offset);
482 		transport->recv.copied = transport->recv.offset;
483 	}
484 }
485 
486 static bool
xs_read_stream_request_done(struct sock_xprt * transport)487 xs_read_stream_request_done(struct sock_xprt *transport)
488 {
489 	return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
490 }
491 
492 static void
xs_read_stream_check_eor(struct sock_xprt * transport,struct msghdr * msg)493 xs_read_stream_check_eor(struct sock_xprt *transport,
494 		struct msghdr *msg)
495 {
496 	if (xs_read_stream_request_done(transport))
497 		msg->msg_flags |= MSG_EOR;
498 }
499 
500 static ssize_t
xs_read_stream_request(struct sock_xprt * transport,struct msghdr * msg,int flags,struct rpc_rqst * req)501 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
502 		int flags, struct rpc_rqst *req)
503 {
504 	struct xdr_buf *buf = &req->rq_private_buf;
505 	size_t want, read;
506 	ssize_t ret;
507 
508 	xs_read_header(transport, buf);
509 
510 	want = transport->recv.len - transport->recv.offset;
511 	if (want != 0) {
512 		ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
513 				transport->recv.copied + want,
514 				transport->recv.copied,
515 				&read);
516 		transport->recv.offset += read;
517 		transport->recv.copied += read;
518 	}
519 
520 	if (transport->recv.offset == transport->recv.len)
521 		xs_read_stream_check_eor(transport, msg);
522 
523 	if (want == 0)
524 		return 0;
525 
526 	switch (ret) {
527 	default:
528 		break;
529 	case -EFAULT:
530 	case -EMSGSIZE:
531 		msg->msg_flags |= MSG_TRUNC;
532 		return read;
533 	case 0:
534 		return -ESHUTDOWN;
535 	}
536 	return ret < 0 ? ret : read;
537 }
538 
539 static size_t
xs_read_stream_headersize(bool isfrag)540 xs_read_stream_headersize(bool isfrag)
541 {
542 	if (isfrag)
543 		return sizeof(__be32);
544 	return 3 * sizeof(__be32);
545 }
546 
547 static ssize_t
xs_read_stream_header(struct sock_xprt * transport,struct msghdr * msg,int flags,size_t want,size_t seek)548 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
549 		int flags, size_t want, size_t seek)
550 {
551 	struct kvec kvec = {
552 		.iov_base = &transport->recv.fraghdr,
553 		.iov_len = want,
554 	};
555 	return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
556 }
557 
558 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
559 static ssize_t
xs_read_stream_call(struct sock_xprt * transport,struct msghdr * msg,int flags)560 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
561 {
562 	struct rpc_xprt *xprt = &transport->xprt;
563 	struct rpc_rqst *req;
564 	ssize_t ret;
565 
566 	/* Is this transport associated with the backchannel? */
567 	if (!xprt->bc_serv)
568 		return -ESHUTDOWN;
569 
570 	/* Look up and lock the request corresponding to the given XID */
571 	req = xprt_lookup_bc_request(xprt, transport->recv.xid);
572 	if (!req) {
573 		printk(KERN_WARNING "Callback slot table overflowed\n");
574 		return -ESHUTDOWN;
575 	}
576 	if (transport->recv.copied && !req->rq_private_buf.len)
577 		return -ESHUTDOWN;
578 
579 	ret = xs_read_stream_request(transport, msg, flags, req);
580 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
581 		xprt_complete_bc_request(req, transport->recv.copied);
582 	else
583 		req->rq_private_buf.len = transport->recv.copied;
584 
585 	return ret;
586 }
587 #else /* CONFIG_SUNRPC_BACKCHANNEL */
588 static ssize_t
xs_read_stream_call(struct sock_xprt * transport,struct msghdr * msg,int flags)589 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
590 {
591 	return -ESHUTDOWN;
592 }
593 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
594 
595 static ssize_t
xs_read_stream_reply(struct sock_xprt * transport,struct msghdr * msg,int flags)596 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
597 {
598 	struct rpc_xprt *xprt = &transport->xprt;
599 	struct rpc_rqst *req;
600 	ssize_t ret = 0;
601 
602 	/* Look up and lock the request corresponding to the given XID */
603 	spin_lock(&xprt->queue_lock);
604 	req = xprt_lookup_rqst(xprt, transport->recv.xid);
605 	if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
606 		msg->msg_flags |= MSG_TRUNC;
607 		goto out;
608 	}
609 	xprt_pin_rqst(req);
610 	spin_unlock(&xprt->queue_lock);
611 
612 	ret = xs_read_stream_request(transport, msg, flags, req);
613 
614 	spin_lock(&xprt->queue_lock);
615 	if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
616 		xprt_complete_rqst(req->rq_task, transport->recv.copied);
617 	else
618 		req->rq_private_buf.len = transport->recv.copied;
619 	xprt_unpin_rqst(req);
620 out:
621 	spin_unlock(&xprt->queue_lock);
622 	return ret;
623 }
624 
625 static ssize_t
xs_read_stream(struct sock_xprt * transport,int flags)626 xs_read_stream(struct sock_xprt *transport, int flags)
627 {
628 	struct msghdr msg = { 0 };
629 	size_t want, read = 0;
630 	ssize_t ret = 0;
631 
632 	if (transport->recv.len == 0) {
633 		want = xs_read_stream_headersize(transport->recv.copied != 0);
634 		ret = xs_read_stream_header(transport, &msg, flags, want,
635 				transport->recv.offset);
636 		if (ret <= 0)
637 			goto out_err;
638 		transport->recv.offset = ret;
639 		if (transport->recv.offset != want)
640 			return transport->recv.offset;
641 		transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
642 			RPC_FRAGMENT_SIZE_MASK;
643 		transport->recv.offset -= sizeof(transport->recv.fraghdr);
644 		read = ret;
645 	}
646 
647 	switch (be32_to_cpu(transport->recv.calldir)) {
648 	default:
649 		msg.msg_flags |= MSG_TRUNC;
650 		break;
651 	case RPC_CALL:
652 		ret = xs_read_stream_call(transport, &msg, flags);
653 		break;
654 	case RPC_REPLY:
655 		ret = xs_read_stream_reply(transport, &msg, flags);
656 	}
657 	if (msg.msg_flags & MSG_TRUNC) {
658 		transport->recv.calldir = cpu_to_be32(-1);
659 		transport->recv.copied = -1;
660 	}
661 	if (ret < 0)
662 		goto out_err;
663 	read += ret;
664 	if (transport->recv.offset < transport->recv.len) {
665 		if (!(msg.msg_flags & MSG_TRUNC))
666 			return read;
667 		msg.msg_flags = 0;
668 		ret = xs_read_discard(transport->sock, &msg, flags,
669 				transport->recv.len - transport->recv.offset);
670 		if (ret <= 0)
671 			goto out_err;
672 		transport->recv.offset += ret;
673 		read += ret;
674 		if (transport->recv.offset != transport->recv.len)
675 			return read;
676 	}
677 	if (xs_read_stream_request_done(transport)) {
678 		trace_xs_stream_read_request(transport);
679 		transport->recv.copied = 0;
680 	}
681 	transport->recv.offset = 0;
682 	transport->recv.len = 0;
683 	return read;
684 out_err:
685 	return ret != 0 ? ret : -ESHUTDOWN;
686 }
687 
xs_poll_socket(struct sock_xprt * transport)688 static __poll_t xs_poll_socket(struct sock_xprt *transport)
689 {
690 	return transport->sock->ops->poll(transport->file, transport->sock,
691 			NULL);
692 }
693 
xs_poll_socket_readable(struct sock_xprt * transport)694 static bool xs_poll_socket_readable(struct sock_xprt *transport)
695 {
696 	__poll_t events = xs_poll_socket(transport);
697 
698 	return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
699 }
700 
xs_poll_check_readable(struct sock_xprt * transport)701 static void xs_poll_check_readable(struct sock_xprt *transport)
702 {
703 
704 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
705 	if (!xs_poll_socket_readable(transport))
706 		return;
707 	if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
708 		queue_work(xprtiod_workqueue, &transport->recv_worker);
709 }
710 
xs_stream_data_receive(struct sock_xprt * transport)711 static void xs_stream_data_receive(struct sock_xprt *transport)
712 {
713 	size_t read = 0;
714 	ssize_t ret = 0;
715 
716 	mutex_lock(&transport->recv_mutex);
717 	if (transport->sock == NULL)
718 		goto out;
719 	for (;;) {
720 		ret = xs_read_stream(transport, MSG_DONTWAIT);
721 		if (ret < 0)
722 			break;
723 		read += ret;
724 		cond_resched();
725 	}
726 	if (ret == -ESHUTDOWN)
727 		kernel_sock_shutdown(transport->sock, SHUT_RDWR);
728 	else
729 		xs_poll_check_readable(transport);
730 out:
731 	mutex_unlock(&transport->recv_mutex);
732 	trace_xs_stream_read_data(&transport->xprt, ret, read);
733 }
734 
xs_stream_data_receive_workfn(struct work_struct * work)735 static void xs_stream_data_receive_workfn(struct work_struct *work)
736 {
737 	struct sock_xprt *transport =
738 		container_of(work, struct sock_xprt, recv_worker);
739 	unsigned int pflags = memalloc_nofs_save();
740 
741 	xs_stream_data_receive(transport);
742 	memalloc_nofs_restore(pflags);
743 }
744 
745 static void
xs_stream_reset_connect(struct sock_xprt * transport)746 xs_stream_reset_connect(struct sock_xprt *transport)
747 {
748 	transport->recv.offset = 0;
749 	transport->recv.len = 0;
750 	transport->recv.copied = 0;
751 	transport->xmit.offset = 0;
752 }
753 
754 static void
xs_stream_start_connect(struct sock_xprt * transport)755 xs_stream_start_connect(struct sock_xprt *transport)
756 {
757 	transport->xprt.stat.connect_count++;
758 	transport->xprt.stat.connect_start = jiffies;
759 }
760 
761 #define XS_SENDMSG_FLAGS	(MSG_DONTWAIT | MSG_NOSIGNAL)
762 
763 /**
764  * xs_nospace - handle transmit was incomplete
765  * @req: pointer to RPC request
766  * @transport: pointer to struct sock_xprt
767  *
768  */
xs_nospace(struct rpc_rqst * req,struct sock_xprt * transport)769 static int xs_nospace(struct rpc_rqst *req, struct sock_xprt *transport)
770 {
771 	struct rpc_xprt *xprt = &transport->xprt;
772 	struct sock *sk = transport->inet;
773 	int ret = -EAGAIN;
774 
775 	trace_rpc_socket_nospace(req, transport);
776 
777 	/* Protect against races with write_space */
778 	spin_lock(&xprt->transport_lock);
779 
780 	/* Don't race with disconnect */
781 	if (xprt_connected(xprt)) {
782 		struct socket_wq *wq;
783 
784 		rcu_read_lock();
785 		wq = rcu_dereference(sk->sk_wq);
786 		set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
787 		rcu_read_unlock();
788 
789 		/* wait for more buffer space */
790 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
791 		sk->sk_write_pending++;
792 		xprt_wait_for_buffer_space(xprt);
793 	} else
794 		ret = -ENOTCONN;
795 
796 	spin_unlock(&xprt->transport_lock);
797 	return ret;
798 }
799 
xs_sock_nospace(struct rpc_rqst * req)800 static int xs_sock_nospace(struct rpc_rqst *req)
801 {
802 	struct sock_xprt *transport =
803 		container_of(req->rq_xprt, struct sock_xprt, xprt);
804 	struct sock *sk = transport->inet;
805 	int ret = -EAGAIN;
806 
807 	lock_sock(sk);
808 	if (!sock_writeable(sk))
809 		ret = xs_nospace(req, transport);
810 	release_sock(sk);
811 	return ret;
812 }
813 
xs_stream_nospace(struct rpc_rqst * req)814 static int xs_stream_nospace(struct rpc_rqst *req)
815 {
816 	struct sock_xprt *transport =
817 		container_of(req->rq_xprt, struct sock_xprt, xprt);
818 	struct sock *sk = transport->inet;
819 	int ret = -EAGAIN;
820 
821 	lock_sock(sk);
822 	if (!sk_stream_memory_free(sk))
823 		ret = xs_nospace(req, transport);
824 	release_sock(sk);
825 	return ret;
826 }
827 
828 static void
xs_stream_prepare_request(struct rpc_rqst * req)829 xs_stream_prepare_request(struct rpc_rqst *req)
830 {
831 	xdr_free_bvec(&req->rq_rcv_buf);
832 	req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
833 }
834 
835 /*
836  * Determine if the previous message in the stream was aborted before it
837  * could complete transmission.
838  */
839 static bool
xs_send_request_was_aborted(struct sock_xprt * transport,struct rpc_rqst * req)840 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
841 {
842 	return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
843 }
844 
845 /*
846  * Return the stream record marker field for a record of length < 2^31-1
847  */
848 static rpc_fraghdr
xs_stream_record_marker(struct xdr_buf * xdr)849 xs_stream_record_marker(struct xdr_buf *xdr)
850 {
851 	if (!xdr->len)
852 		return 0;
853 	return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
854 }
855 
856 /**
857  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
858  * @req: pointer to RPC request
859  *
860  * Return values:
861  *        0:	The request has been sent
862  *   EAGAIN:	The socket was blocked, please call again later to
863  *		complete the request
864  * ENOTCONN:	Caller needs to invoke connect logic then call again
865  *    other:	Some other error occurred, the request was not sent
866  */
xs_local_send_request(struct rpc_rqst * req)867 static int xs_local_send_request(struct rpc_rqst *req)
868 {
869 	struct rpc_xprt *xprt = req->rq_xprt;
870 	struct sock_xprt *transport =
871 				container_of(xprt, struct sock_xprt, xprt);
872 	struct xdr_buf *xdr = &req->rq_snd_buf;
873 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
874 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
875 	struct msghdr msg = {
876 		.msg_flags	= XS_SENDMSG_FLAGS,
877 	};
878 	unsigned int sent;
879 	int status;
880 
881 	/* Close the stream if the previous transmission was incomplete */
882 	if (xs_send_request_was_aborted(transport, req)) {
883 		xprt_force_disconnect(xprt);
884 		return -ENOTCONN;
885 	}
886 
887 	xs_pktdump("packet data:",
888 			req->rq_svec->iov_base, req->rq_svec->iov_len);
889 
890 	req->rq_xtime = ktime_get();
891 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
892 				   transport->xmit.offset, rm, &sent);
893 	dprintk("RPC:       %s(%u) = %d\n",
894 			__func__, xdr->len - transport->xmit.offset, status);
895 
896 	if (status == -EAGAIN && sock_writeable(transport->inet))
897 		status = -ENOBUFS;
898 
899 	if (likely(sent > 0) || status == 0) {
900 		transport->xmit.offset += sent;
901 		req->rq_bytes_sent = transport->xmit.offset;
902 		if (likely(req->rq_bytes_sent >= msglen)) {
903 			req->rq_xmit_bytes_sent += transport->xmit.offset;
904 			transport->xmit.offset = 0;
905 			return 0;
906 		}
907 		status = -EAGAIN;
908 	}
909 
910 	switch (status) {
911 	case -ENOBUFS:
912 		break;
913 	case -EAGAIN:
914 		status = xs_stream_nospace(req);
915 		break;
916 	default:
917 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
918 			-status);
919 		fallthrough;
920 	case -EPIPE:
921 		xprt_force_disconnect(xprt);
922 		status = -ENOTCONN;
923 	}
924 
925 	return status;
926 }
927 
928 /**
929  * xs_udp_send_request - write an RPC request to a UDP socket
930  * @req: pointer to RPC request
931  *
932  * Return values:
933  *        0:	The request has been sent
934  *   EAGAIN:	The socket was blocked, please call again later to
935  *		complete the request
936  * ENOTCONN:	Caller needs to invoke connect logic then call again
937  *    other:	Some other error occurred, the request was not sent
938  */
xs_udp_send_request(struct rpc_rqst * req)939 static int xs_udp_send_request(struct rpc_rqst *req)
940 {
941 	struct rpc_xprt *xprt = req->rq_xprt;
942 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
943 	struct xdr_buf *xdr = &req->rq_snd_buf;
944 	struct msghdr msg = {
945 		.msg_name	= xs_addr(xprt),
946 		.msg_namelen	= xprt->addrlen,
947 		.msg_flags	= XS_SENDMSG_FLAGS,
948 	};
949 	unsigned int sent;
950 	int status;
951 
952 	xs_pktdump("packet data:",
953 				req->rq_svec->iov_base,
954 				req->rq_svec->iov_len);
955 
956 	if (!xprt_bound(xprt))
957 		return -ENOTCONN;
958 
959 	if (!xprt_request_get_cong(xprt, req))
960 		return -EBADSLT;
961 
962 	req->rq_xtime = ktime_get();
963 	status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
964 
965 	dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
966 			xdr->len, status);
967 
968 	/* firewall is blocking us, don't return -EAGAIN or we end up looping */
969 	if (status == -EPERM)
970 		goto process_status;
971 
972 	if (status == -EAGAIN && sock_writeable(transport->inet))
973 		status = -ENOBUFS;
974 
975 	if (sent > 0 || status == 0) {
976 		req->rq_xmit_bytes_sent += sent;
977 		if (sent >= req->rq_slen)
978 			return 0;
979 		/* Still some bytes left; set up for a retry later. */
980 		status = -EAGAIN;
981 	}
982 
983 process_status:
984 	switch (status) {
985 	case -ENOTSOCK:
986 		status = -ENOTCONN;
987 		/* Should we call xs_close() here? */
988 		break;
989 	case -EAGAIN:
990 		status = xs_sock_nospace(req);
991 		break;
992 	case -ENETUNREACH:
993 	case -ENOBUFS:
994 	case -EPIPE:
995 	case -ECONNREFUSED:
996 	case -EPERM:
997 		/* When the server has died, an ICMP port unreachable message
998 		 * prompts ECONNREFUSED. */
999 		break;
1000 	default:
1001 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1002 			-status);
1003 	}
1004 
1005 	return status;
1006 }
1007 
1008 /**
1009  * xs_tcp_send_request - write an RPC request to a TCP socket
1010  * @req: pointer to RPC request
1011  *
1012  * Return values:
1013  *        0:	The request has been sent
1014  *   EAGAIN:	The socket was blocked, please call again later to
1015  *		complete the request
1016  * ENOTCONN:	Caller needs to invoke connect logic then call again
1017  *    other:	Some other error occurred, the request was not sent
1018  *
1019  * XXX: In the case of soft timeouts, should we eventually give up
1020  *	if sendmsg is not able to make progress?
1021  */
xs_tcp_send_request(struct rpc_rqst * req)1022 static int xs_tcp_send_request(struct rpc_rqst *req)
1023 {
1024 	struct rpc_xprt *xprt = req->rq_xprt;
1025 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1026 	struct xdr_buf *xdr = &req->rq_snd_buf;
1027 	rpc_fraghdr rm = xs_stream_record_marker(xdr);
1028 	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1029 	struct msghdr msg = {
1030 		.msg_flags	= XS_SENDMSG_FLAGS,
1031 	};
1032 	bool vm_wait = false;
1033 	unsigned int sent;
1034 	int status;
1035 
1036 	/* Close the stream if the previous transmission was incomplete */
1037 	if (xs_send_request_was_aborted(transport, req)) {
1038 		if (transport->sock != NULL)
1039 			kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1040 		return -ENOTCONN;
1041 	}
1042 	if (!transport->inet)
1043 		return -ENOTCONN;
1044 
1045 	xs_pktdump("packet data:",
1046 				req->rq_svec->iov_base,
1047 				req->rq_svec->iov_len);
1048 
1049 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1050 		xs_tcp_set_socket_timeouts(xprt, transport->sock);
1051 
1052 	/* Continue transmitting the packet/record. We must be careful
1053 	 * to cope with writespace callbacks arriving _after_ we have
1054 	 * called sendmsg(). */
1055 	req->rq_xtime = ktime_get();
1056 	tcp_sock_set_cork(transport->inet, true);
1057 	while (1) {
1058 		status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1059 					   transport->xmit.offset, rm, &sent);
1060 
1061 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1062 				xdr->len - transport->xmit.offset, status);
1063 
1064 		/* If we've sent the entire packet, immediately
1065 		 * reset the count of bytes sent. */
1066 		transport->xmit.offset += sent;
1067 		req->rq_bytes_sent = transport->xmit.offset;
1068 		if (likely(req->rq_bytes_sent >= msglen)) {
1069 			req->rq_xmit_bytes_sent += transport->xmit.offset;
1070 			transport->xmit.offset = 0;
1071 			if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1072 				tcp_sock_set_cork(transport->inet, false);
1073 			return 0;
1074 		}
1075 
1076 		WARN_ON_ONCE(sent == 0 && status == 0);
1077 
1078 		if (status == -EAGAIN ) {
1079 			/*
1080 			 * Return EAGAIN if we're sure we're hitting the
1081 			 * socket send buffer limits.
1082 			 */
1083 			if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1084 				break;
1085 			/*
1086 			 * Did we hit a memory allocation failure?
1087 			 */
1088 			if (sent == 0) {
1089 				status = -ENOBUFS;
1090 				if (vm_wait)
1091 					break;
1092 				/* Retry, knowing now that we're below the
1093 				 * socket send buffer limit
1094 				 */
1095 				vm_wait = true;
1096 			}
1097 			continue;
1098 		}
1099 		if (status < 0)
1100 			break;
1101 		vm_wait = false;
1102 	}
1103 
1104 	switch (status) {
1105 	case -ENOTSOCK:
1106 		status = -ENOTCONN;
1107 		/* Should we call xs_close() here? */
1108 		break;
1109 	case -EAGAIN:
1110 		status = xs_stream_nospace(req);
1111 		break;
1112 	case -ECONNRESET:
1113 	case -ECONNREFUSED:
1114 	case -ENOTCONN:
1115 	case -EADDRINUSE:
1116 	case -ENOBUFS:
1117 	case -EPIPE:
1118 		break;
1119 	default:
1120 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1121 			-status);
1122 	}
1123 
1124 	return status;
1125 }
1126 
xs_save_old_callbacks(struct sock_xprt * transport,struct sock * sk)1127 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1128 {
1129 	transport->old_data_ready = sk->sk_data_ready;
1130 	transport->old_state_change = sk->sk_state_change;
1131 	transport->old_write_space = sk->sk_write_space;
1132 	transport->old_error_report = sk->sk_error_report;
1133 }
1134 
xs_restore_old_callbacks(struct sock_xprt * transport,struct sock * sk)1135 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1136 {
1137 	sk->sk_data_ready = transport->old_data_ready;
1138 	sk->sk_state_change = transport->old_state_change;
1139 	sk->sk_write_space = transport->old_write_space;
1140 	sk->sk_error_report = transport->old_error_report;
1141 }
1142 
xs_sock_reset_state_flags(struct rpc_xprt * xprt)1143 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1144 {
1145 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1146 
1147 	clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1148 	clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1149 	clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1150 	clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1151 }
1152 
xs_run_error_worker(struct sock_xprt * transport,unsigned int nr)1153 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1154 {
1155 	set_bit(nr, &transport->sock_state);
1156 	queue_work(xprtiod_workqueue, &transport->error_worker);
1157 }
1158 
xs_sock_reset_connection_flags(struct rpc_xprt * xprt)1159 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1160 {
1161 	smp_mb__before_atomic();
1162 	clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1163 	clear_bit(XPRT_CLOSING, &xprt->state);
1164 	xs_sock_reset_state_flags(xprt);
1165 	smp_mb__after_atomic();
1166 }
1167 
1168 /**
1169  * xs_error_report - callback to handle TCP socket state errors
1170  * @sk: socket
1171  *
1172  * Note: we don't call sock_error() since there may be a rpc_task
1173  * using the socket, and so we don't want to clear sk->sk_err.
1174  */
xs_error_report(struct sock * sk)1175 static void xs_error_report(struct sock *sk)
1176 {
1177 	struct sock_xprt *transport;
1178 	struct rpc_xprt *xprt;
1179 
1180 	read_lock_bh(&sk->sk_callback_lock);
1181 	if (!(xprt = xprt_from_sock(sk)))
1182 		goto out;
1183 
1184 	transport = container_of(xprt, struct sock_xprt, xprt);
1185 	transport->xprt_err = -sk->sk_err;
1186 	if (transport->xprt_err == 0)
1187 		goto out;
1188 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1189 			xprt, -transport->xprt_err);
1190 	trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1191 
1192 	/* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1193 	smp_mb__before_atomic();
1194 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1195  out:
1196 	read_unlock_bh(&sk->sk_callback_lock);
1197 }
1198 
xs_reset_transport(struct sock_xprt * transport)1199 static void xs_reset_transport(struct sock_xprt *transport)
1200 {
1201 	struct socket *sock = transport->sock;
1202 	struct sock *sk = transport->inet;
1203 	struct rpc_xprt *xprt = &transport->xprt;
1204 	struct file *filp = transport->file;
1205 
1206 	if (sk == NULL)
1207 		return;
1208 	/*
1209 	 * Make sure we're calling this in a context from which it is safe
1210 	 * to call __fput_sync(). In practice that means rpciod and the
1211 	 * system workqueue.
1212 	 */
1213 	if (!(current->flags & PF_WQ_WORKER)) {
1214 		WARN_ON_ONCE(1);
1215 		set_bit(XPRT_CLOSE_WAIT, &xprt->state);
1216 		return;
1217 	}
1218 
1219 	if (atomic_read(&transport->xprt.swapper))
1220 		sk_clear_memalloc(sk);
1221 
1222 	kernel_sock_shutdown(sock, SHUT_RDWR);
1223 
1224 	mutex_lock(&transport->recv_mutex);
1225 	write_lock_bh(&sk->sk_callback_lock);
1226 	transport->inet = NULL;
1227 	transport->sock = NULL;
1228 	transport->file = NULL;
1229 
1230 	sk->sk_user_data = NULL;
1231 
1232 	xs_restore_old_callbacks(transport, sk);
1233 	xprt_clear_connected(xprt);
1234 	write_unlock_bh(&sk->sk_callback_lock);
1235 	xs_sock_reset_connection_flags(xprt);
1236 	/* Reset stream record info */
1237 	xs_stream_reset_connect(transport);
1238 	mutex_unlock(&transport->recv_mutex);
1239 
1240 	trace_rpc_socket_close(xprt, sock);
1241 	__fput_sync(filp);
1242 
1243 	xprt_disconnect_done(xprt);
1244 }
1245 
1246 /**
1247  * xs_close - close a socket
1248  * @xprt: transport
1249  *
1250  * This is used when all requests are complete; ie, no DRC state remains
1251  * on the server we want to save.
1252  *
1253  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1254  * xs_reset_transport() zeroing the socket from underneath a writer.
1255  */
xs_close(struct rpc_xprt * xprt)1256 static void xs_close(struct rpc_xprt *xprt)
1257 {
1258 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1259 
1260 	dprintk("RPC:       xs_close xprt %p\n", xprt);
1261 
1262 	xs_reset_transport(transport);
1263 	xprt->reestablish_timeout = 0;
1264 }
1265 
xs_inject_disconnect(struct rpc_xprt * xprt)1266 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1267 {
1268 	dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1269 		xprt);
1270 	xprt_disconnect_done(xprt);
1271 }
1272 
xs_xprt_free(struct rpc_xprt * xprt)1273 static void xs_xprt_free(struct rpc_xprt *xprt)
1274 {
1275 	xs_free_peer_addresses(xprt);
1276 	xprt_free(xprt);
1277 }
1278 
1279 /**
1280  * xs_destroy - prepare to shutdown a transport
1281  * @xprt: doomed transport
1282  *
1283  */
xs_destroy(struct rpc_xprt * xprt)1284 static void xs_destroy(struct rpc_xprt *xprt)
1285 {
1286 	struct sock_xprt *transport = container_of(xprt,
1287 			struct sock_xprt, xprt);
1288 	dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1289 
1290 	cancel_delayed_work_sync(&transport->connect_worker);
1291 	xs_close(xprt);
1292 	cancel_work_sync(&transport->recv_worker);
1293 	cancel_work_sync(&transport->error_worker);
1294 	xs_xprt_free(xprt);
1295 	module_put(THIS_MODULE);
1296 }
1297 
1298 /**
1299  * xs_udp_data_read_skb - receive callback for UDP sockets
1300  * @xprt: transport
1301  * @sk: socket
1302  * @skb: skbuff
1303  *
1304  */
xs_udp_data_read_skb(struct rpc_xprt * xprt,struct sock * sk,struct sk_buff * skb)1305 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1306 		struct sock *sk,
1307 		struct sk_buff *skb)
1308 {
1309 	struct rpc_task *task;
1310 	struct rpc_rqst *rovr;
1311 	int repsize, copied;
1312 	u32 _xid;
1313 	__be32 *xp;
1314 
1315 	repsize = skb->len;
1316 	if (repsize < 4) {
1317 		dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1318 		return;
1319 	}
1320 
1321 	/* Copy the XID from the skb... */
1322 	xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1323 	if (xp == NULL)
1324 		return;
1325 
1326 	/* Look up and lock the request corresponding to the given XID */
1327 	spin_lock(&xprt->queue_lock);
1328 	rovr = xprt_lookup_rqst(xprt, *xp);
1329 	if (!rovr)
1330 		goto out_unlock;
1331 	xprt_pin_rqst(rovr);
1332 	xprt_update_rtt(rovr->rq_task);
1333 	spin_unlock(&xprt->queue_lock);
1334 	task = rovr->rq_task;
1335 
1336 	if ((copied = rovr->rq_private_buf.buflen) > repsize)
1337 		copied = repsize;
1338 
1339 	/* Suck it into the iovec, verify checksum if not done by hw. */
1340 	if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1341 		spin_lock(&xprt->queue_lock);
1342 		__UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1343 		goto out_unpin;
1344 	}
1345 
1346 
1347 	spin_lock(&xprt->transport_lock);
1348 	xprt_adjust_cwnd(xprt, task, copied);
1349 	spin_unlock(&xprt->transport_lock);
1350 	spin_lock(&xprt->queue_lock);
1351 	xprt_complete_rqst(task, copied);
1352 	__UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1353 out_unpin:
1354 	xprt_unpin_rqst(rovr);
1355  out_unlock:
1356 	spin_unlock(&xprt->queue_lock);
1357 }
1358 
xs_udp_data_receive(struct sock_xprt * transport)1359 static void xs_udp_data_receive(struct sock_xprt *transport)
1360 {
1361 	struct sk_buff *skb;
1362 	struct sock *sk;
1363 	int err;
1364 
1365 	mutex_lock(&transport->recv_mutex);
1366 	sk = transport->inet;
1367 	if (sk == NULL)
1368 		goto out;
1369 	for (;;) {
1370 		skb = skb_recv_udp(sk, 0, 1, &err);
1371 		if (skb == NULL)
1372 			break;
1373 		xs_udp_data_read_skb(&transport->xprt, sk, skb);
1374 		consume_skb(skb);
1375 		cond_resched();
1376 	}
1377 	xs_poll_check_readable(transport);
1378 out:
1379 	mutex_unlock(&transport->recv_mutex);
1380 }
1381 
xs_udp_data_receive_workfn(struct work_struct * work)1382 static void xs_udp_data_receive_workfn(struct work_struct *work)
1383 {
1384 	struct sock_xprt *transport =
1385 		container_of(work, struct sock_xprt, recv_worker);
1386 	unsigned int pflags = memalloc_nofs_save();
1387 
1388 	xs_udp_data_receive(transport);
1389 	memalloc_nofs_restore(pflags);
1390 }
1391 
1392 /**
1393  * xs_data_ready - "data ready" callback for UDP sockets
1394  * @sk: socket with data to read
1395  *
1396  */
xs_data_ready(struct sock * sk)1397 static void xs_data_ready(struct sock *sk)
1398 {
1399 	struct rpc_xprt *xprt;
1400 
1401 	read_lock_bh(&sk->sk_callback_lock);
1402 	dprintk("RPC:       xs_data_ready...\n");
1403 	xprt = xprt_from_sock(sk);
1404 	if (xprt != NULL) {
1405 		struct sock_xprt *transport = container_of(xprt,
1406 				struct sock_xprt, xprt);
1407 		transport->old_data_ready(sk);
1408 		/* Any data means we had a useful conversation, so
1409 		 * then we don't need to delay the next reconnect
1410 		 */
1411 		if (xprt->reestablish_timeout)
1412 			xprt->reestablish_timeout = 0;
1413 		if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1414 			queue_work(xprtiod_workqueue, &transport->recv_worker);
1415 	}
1416 	read_unlock_bh(&sk->sk_callback_lock);
1417 }
1418 
1419 /*
1420  * Helper function to force a TCP close if the server is sending
1421  * junk and/or it has put us in CLOSE_WAIT
1422  */
xs_tcp_force_close(struct rpc_xprt * xprt)1423 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1424 {
1425 	xprt_force_disconnect(xprt);
1426 }
1427 
1428 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
xs_tcp_bc_maxpayload(struct rpc_xprt * xprt)1429 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1430 {
1431 	return PAGE_SIZE;
1432 }
1433 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1434 
1435 /**
1436  * xs_tcp_state_change - callback to handle TCP socket state changes
1437  * @sk: socket whose state has changed
1438  *
1439  */
xs_tcp_state_change(struct sock * sk)1440 static void xs_tcp_state_change(struct sock *sk)
1441 {
1442 	struct rpc_xprt *xprt;
1443 	struct sock_xprt *transport;
1444 
1445 	read_lock_bh(&sk->sk_callback_lock);
1446 	if (!(xprt = xprt_from_sock(sk)))
1447 		goto out;
1448 	dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1449 	dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1450 			sk->sk_state, xprt_connected(xprt),
1451 			sock_flag(sk, SOCK_DEAD),
1452 			sock_flag(sk, SOCK_ZAPPED),
1453 			sk->sk_shutdown);
1454 
1455 	transport = container_of(xprt, struct sock_xprt, xprt);
1456 	trace_rpc_socket_state_change(xprt, sk->sk_socket);
1457 	switch (sk->sk_state) {
1458 	case TCP_ESTABLISHED:
1459 		if (!xprt_test_and_set_connected(xprt)) {
1460 			xprt->connect_cookie++;
1461 			clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1462 			xprt_clear_connecting(xprt);
1463 
1464 			xprt->stat.connect_count++;
1465 			xprt->stat.connect_time += (long)jiffies -
1466 						   xprt->stat.connect_start;
1467 			xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1468 		}
1469 		break;
1470 	case TCP_FIN_WAIT1:
1471 		/* The client initiated a shutdown of the socket */
1472 		xprt->connect_cookie++;
1473 		xprt->reestablish_timeout = 0;
1474 		set_bit(XPRT_CLOSING, &xprt->state);
1475 		smp_mb__before_atomic();
1476 		clear_bit(XPRT_CONNECTED, &xprt->state);
1477 		clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1478 		smp_mb__after_atomic();
1479 		break;
1480 	case TCP_CLOSE_WAIT:
1481 		/* The server initiated a shutdown of the socket */
1482 		xprt->connect_cookie++;
1483 		clear_bit(XPRT_CONNECTED, &xprt->state);
1484 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1485 		fallthrough;
1486 	case TCP_CLOSING:
1487 		/*
1488 		 * If the server closed down the connection, make sure that
1489 		 * we back off before reconnecting
1490 		 */
1491 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1492 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1493 		break;
1494 	case TCP_LAST_ACK:
1495 		set_bit(XPRT_CLOSING, &xprt->state);
1496 		smp_mb__before_atomic();
1497 		clear_bit(XPRT_CONNECTED, &xprt->state);
1498 		smp_mb__after_atomic();
1499 		break;
1500 	case TCP_CLOSE:
1501 		if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1502 					&transport->sock_state))
1503 			xprt_clear_connecting(xprt);
1504 		clear_bit(XPRT_CLOSING, &xprt->state);
1505 		/* Trigger the socket release */
1506 		xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1507 	}
1508  out:
1509 	read_unlock_bh(&sk->sk_callback_lock);
1510 }
1511 
xs_write_space(struct sock * sk)1512 static void xs_write_space(struct sock *sk)
1513 {
1514 	struct socket_wq *wq;
1515 	struct sock_xprt *transport;
1516 	struct rpc_xprt *xprt;
1517 
1518 	if (!sk->sk_socket)
1519 		return;
1520 	clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1521 
1522 	if (unlikely(!(xprt = xprt_from_sock(sk))))
1523 		return;
1524 	transport = container_of(xprt, struct sock_xprt, xprt);
1525 	rcu_read_lock();
1526 	wq = rcu_dereference(sk->sk_wq);
1527 	if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1528 		goto out;
1529 
1530 	xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1531 	sk->sk_write_pending--;
1532 out:
1533 	rcu_read_unlock();
1534 }
1535 
1536 /**
1537  * xs_udp_write_space - callback invoked when socket buffer space
1538  *                             becomes available
1539  * @sk: socket whose state has changed
1540  *
1541  * Called when more output buffer space is available for this socket.
1542  * We try not to wake our writers until they can make "significant"
1543  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1544  * with a bunch of small requests.
1545  */
xs_udp_write_space(struct sock * sk)1546 static void xs_udp_write_space(struct sock *sk)
1547 {
1548 	read_lock_bh(&sk->sk_callback_lock);
1549 
1550 	/* from net/core/sock.c:sock_def_write_space */
1551 	if (sock_writeable(sk))
1552 		xs_write_space(sk);
1553 
1554 	read_unlock_bh(&sk->sk_callback_lock);
1555 }
1556 
1557 /**
1558  * xs_tcp_write_space - callback invoked when socket buffer space
1559  *                             becomes available
1560  * @sk: socket whose state has changed
1561  *
1562  * Called when more output buffer space is available for this socket.
1563  * We try not to wake our writers until they can make "significant"
1564  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1565  * with a bunch of small requests.
1566  */
xs_tcp_write_space(struct sock * sk)1567 static void xs_tcp_write_space(struct sock *sk)
1568 {
1569 	read_lock_bh(&sk->sk_callback_lock);
1570 
1571 	/* from net/core/stream.c:sk_stream_write_space */
1572 	if (sk_stream_is_writeable(sk))
1573 		xs_write_space(sk);
1574 
1575 	read_unlock_bh(&sk->sk_callback_lock);
1576 }
1577 
xs_udp_do_set_buffer_size(struct rpc_xprt * xprt)1578 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1579 {
1580 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1581 	struct sock *sk = transport->inet;
1582 
1583 	if (transport->rcvsize) {
1584 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1585 		sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1586 	}
1587 	if (transport->sndsize) {
1588 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1589 		sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1590 		sk->sk_write_space(sk);
1591 	}
1592 }
1593 
1594 /**
1595  * xs_udp_set_buffer_size - set send and receive limits
1596  * @xprt: generic transport
1597  * @sndsize: requested size of send buffer, in bytes
1598  * @rcvsize: requested size of receive buffer, in bytes
1599  *
1600  * Set socket send and receive buffer size limits.
1601  */
xs_udp_set_buffer_size(struct rpc_xprt * xprt,size_t sndsize,size_t rcvsize)1602 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1603 {
1604 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1605 
1606 	transport->sndsize = 0;
1607 	if (sndsize)
1608 		transport->sndsize = sndsize + 1024;
1609 	transport->rcvsize = 0;
1610 	if (rcvsize)
1611 		transport->rcvsize = rcvsize + 1024;
1612 
1613 	xs_udp_do_set_buffer_size(xprt);
1614 }
1615 
1616 /**
1617  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1618  * @xprt: controlling transport
1619  * @task: task that timed out
1620  *
1621  * Adjust the congestion window after a retransmit timeout has occurred.
1622  */
xs_udp_timer(struct rpc_xprt * xprt,struct rpc_task * task)1623 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1624 {
1625 	spin_lock(&xprt->transport_lock);
1626 	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1627 	spin_unlock(&xprt->transport_lock);
1628 }
1629 
xs_get_random_port(void)1630 static int xs_get_random_port(void)
1631 {
1632 	unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1633 	unsigned short range;
1634 	unsigned short rand;
1635 
1636 	if (max < min)
1637 		return -EADDRINUSE;
1638 	range = max - min + 1;
1639 	rand = (unsigned short) prandom_u32() % range;
1640 	return rand + min;
1641 }
1642 
xs_sock_getport(struct socket * sock)1643 static unsigned short xs_sock_getport(struct socket *sock)
1644 {
1645 	struct sockaddr_storage buf;
1646 	unsigned short port = 0;
1647 
1648 	if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1649 		goto out;
1650 	switch (buf.ss_family) {
1651 	case AF_INET6:
1652 		port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1653 		break;
1654 	case AF_INET:
1655 		port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1656 	}
1657 out:
1658 	return port;
1659 }
1660 
1661 /**
1662  * xs_set_port - reset the port number in the remote endpoint address
1663  * @xprt: generic transport
1664  * @port: new port number
1665  *
1666  */
xs_set_port(struct rpc_xprt * xprt,unsigned short port)1667 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1668 {
1669 	dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1670 
1671 	rpc_set_port(xs_addr(xprt), port);
1672 	xs_update_peer_port(xprt);
1673 }
1674 
xs_set_srcport(struct sock_xprt * transport,struct socket * sock)1675 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1676 {
1677 	if (transport->srcport == 0 && transport->xprt.reuseport)
1678 		transport->srcport = xs_sock_getport(sock);
1679 }
1680 
xs_get_srcport(struct sock_xprt * transport)1681 static int xs_get_srcport(struct sock_xprt *transport)
1682 {
1683 	int port = transport->srcport;
1684 
1685 	if (port == 0 && transport->xprt.resvport)
1686 		port = xs_get_random_port();
1687 	return port;
1688 }
1689 
get_srcport(struct rpc_xprt * xprt)1690 unsigned short get_srcport(struct rpc_xprt *xprt)
1691 {
1692 	struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1693 	return xs_sock_getport(sock->sock);
1694 }
1695 EXPORT_SYMBOL(get_srcport);
1696 
xs_next_srcport(struct sock_xprt * transport,unsigned short port)1697 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1698 {
1699 	if (transport->srcport != 0)
1700 		transport->srcport = 0;
1701 	if (!transport->xprt.resvport)
1702 		return 0;
1703 	if (port <= xprt_min_resvport || port > xprt_max_resvport)
1704 		return xprt_max_resvport;
1705 	return --port;
1706 }
xs_bind(struct sock_xprt * transport,struct socket * sock)1707 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1708 {
1709 	struct sockaddr_storage myaddr;
1710 	int err, nloop = 0;
1711 	int port = xs_get_srcport(transport);
1712 	unsigned short last;
1713 
1714 	/*
1715 	 * If we are asking for any ephemeral port (i.e. port == 0 &&
1716 	 * transport->xprt.resvport == 0), don't bind.  Let the local
1717 	 * port selection happen implicitly when the socket is used
1718 	 * (for example at connect time).
1719 	 *
1720 	 * This ensures that we can continue to establish TCP
1721 	 * connections even when all local ephemeral ports are already
1722 	 * a part of some TCP connection.  This makes no difference
1723 	 * for UDP sockets, but also doesn't harm them.
1724 	 *
1725 	 * If we're asking for any reserved port (i.e. port == 0 &&
1726 	 * transport->xprt.resvport == 1) xs_get_srcport above will
1727 	 * ensure that port is non-zero and we will bind as needed.
1728 	 */
1729 	if (port <= 0)
1730 		return port;
1731 
1732 	memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1733 	do {
1734 		rpc_set_port((struct sockaddr *)&myaddr, port);
1735 		err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1736 				transport->xprt.addrlen);
1737 		if (err == 0) {
1738 			if (transport->xprt.reuseport)
1739 				transport->srcport = port;
1740 			break;
1741 		}
1742 		last = port;
1743 		port = xs_next_srcport(transport, port);
1744 		if (port > last)
1745 			nloop++;
1746 	} while (err == -EADDRINUSE && nloop != 2);
1747 
1748 	if (myaddr.ss_family == AF_INET)
1749 		dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1750 				&((struct sockaddr_in *)&myaddr)->sin_addr,
1751 				port, err ? "failed" : "ok", err);
1752 	else
1753 		dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1754 				&((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1755 				port, err ? "failed" : "ok", err);
1756 	return err;
1757 }
1758 
1759 /*
1760  * We don't support autobind on AF_LOCAL sockets
1761  */
xs_local_rpcbind(struct rpc_task * task)1762 static void xs_local_rpcbind(struct rpc_task *task)
1763 {
1764 	xprt_set_bound(task->tk_xprt);
1765 }
1766 
xs_local_set_port(struct rpc_xprt * xprt,unsigned short port)1767 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1768 {
1769 }
1770 
1771 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1772 static struct lock_class_key xs_key[2];
1773 static struct lock_class_key xs_slock_key[2];
1774 
xs_reclassify_socketu(struct socket * sock)1775 static inline void xs_reclassify_socketu(struct socket *sock)
1776 {
1777 	struct sock *sk = sock->sk;
1778 
1779 	sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1780 		&xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1781 }
1782 
xs_reclassify_socket4(struct socket * sock)1783 static inline void xs_reclassify_socket4(struct socket *sock)
1784 {
1785 	struct sock *sk = sock->sk;
1786 
1787 	sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1788 		&xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1789 }
1790 
xs_reclassify_socket6(struct socket * sock)1791 static inline void xs_reclassify_socket6(struct socket *sock)
1792 {
1793 	struct sock *sk = sock->sk;
1794 
1795 	sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1796 		&xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1797 }
1798 
xs_reclassify_socket(int family,struct socket * sock)1799 static inline void xs_reclassify_socket(int family, struct socket *sock)
1800 {
1801 	if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1802 		return;
1803 
1804 	switch (family) {
1805 	case AF_LOCAL:
1806 		xs_reclassify_socketu(sock);
1807 		break;
1808 	case AF_INET:
1809 		xs_reclassify_socket4(sock);
1810 		break;
1811 	case AF_INET6:
1812 		xs_reclassify_socket6(sock);
1813 		break;
1814 	}
1815 }
1816 #else
xs_reclassify_socket(int family,struct socket * sock)1817 static inline void xs_reclassify_socket(int family, struct socket *sock)
1818 {
1819 }
1820 #endif
1821 
xs_dummy_setup_socket(struct work_struct * work)1822 static void xs_dummy_setup_socket(struct work_struct *work)
1823 {
1824 }
1825 
xs_create_sock(struct rpc_xprt * xprt,struct sock_xprt * transport,int family,int type,int protocol,bool reuseport)1826 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1827 		struct sock_xprt *transport, int family, int type,
1828 		int protocol, bool reuseport)
1829 {
1830 	struct file *filp;
1831 	struct socket *sock;
1832 	int err;
1833 
1834 	err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1835 	if (err < 0) {
1836 		dprintk("RPC:       can't create %d transport socket (%d).\n",
1837 				protocol, -err);
1838 		goto out;
1839 	}
1840 	xs_reclassify_socket(family, sock);
1841 
1842 	if (reuseport)
1843 		sock_set_reuseport(sock->sk);
1844 
1845 	err = xs_bind(transport, sock);
1846 	if (err) {
1847 		sock_release(sock);
1848 		goto out;
1849 	}
1850 
1851 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1852 	if (IS_ERR(filp))
1853 		return ERR_CAST(filp);
1854 	transport->file = filp;
1855 
1856 	return sock;
1857 out:
1858 	return ERR_PTR(err);
1859 }
1860 
xs_local_finish_connecting(struct rpc_xprt * xprt,struct socket * sock)1861 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1862 				      struct socket *sock)
1863 {
1864 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1865 									xprt);
1866 
1867 	if (!transport->inet) {
1868 		struct sock *sk = sock->sk;
1869 
1870 		write_lock_bh(&sk->sk_callback_lock);
1871 
1872 		xs_save_old_callbacks(transport, sk);
1873 
1874 		sk->sk_user_data = xprt;
1875 		sk->sk_data_ready = xs_data_ready;
1876 		sk->sk_write_space = xs_udp_write_space;
1877 		sock_set_flag(sk, SOCK_FASYNC);
1878 		sk->sk_error_report = xs_error_report;
1879 
1880 		xprt_clear_connected(xprt);
1881 
1882 		/* Reset to new socket */
1883 		transport->sock = sock;
1884 		transport->inet = sk;
1885 
1886 		write_unlock_bh(&sk->sk_callback_lock);
1887 	}
1888 
1889 	xs_stream_start_connect(transport);
1890 
1891 	return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1892 }
1893 
1894 /**
1895  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1896  * @transport: socket transport to connect
1897  */
xs_local_setup_socket(struct sock_xprt * transport)1898 static int xs_local_setup_socket(struct sock_xprt *transport)
1899 {
1900 	struct rpc_xprt *xprt = &transport->xprt;
1901 	struct file *filp;
1902 	struct socket *sock;
1903 	int status;
1904 
1905 	status = __sock_create(xprt->xprt_net, AF_LOCAL,
1906 					SOCK_STREAM, 0, &sock, 1);
1907 	if (status < 0) {
1908 		dprintk("RPC:       can't create AF_LOCAL "
1909 			"transport socket (%d).\n", -status);
1910 		goto out;
1911 	}
1912 	xs_reclassify_socket(AF_LOCAL, sock);
1913 
1914 	filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1915 	if (IS_ERR(filp)) {
1916 		status = PTR_ERR(filp);
1917 		goto out;
1918 	}
1919 	transport->file = filp;
1920 
1921 	dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1922 			xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1923 
1924 	status = xs_local_finish_connecting(xprt, sock);
1925 	trace_rpc_socket_connect(xprt, sock, status);
1926 	switch (status) {
1927 	case 0:
1928 		dprintk("RPC:       xprt %p connected to %s\n",
1929 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1930 		xprt->stat.connect_count++;
1931 		xprt->stat.connect_time += (long)jiffies -
1932 					   xprt->stat.connect_start;
1933 		xprt_set_connected(xprt);
1934 		break;
1935 	case -ENOBUFS:
1936 		break;
1937 	case -ENOENT:
1938 		dprintk("RPC:       xprt %p: socket %s does not exist\n",
1939 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1940 		break;
1941 	case -ECONNREFUSED:
1942 		dprintk("RPC:       xprt %p: connection refused for %s\n",
1943 				xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1944 		break;
1945 	default:
1946 		printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1947 				__func__, -status,
1948 				xprt->address_strings[RPC_DISPLAY_ADDR]);
1949 	}
1950 
1951 out:
1952 	xprt_clear_connecting(xprt);
1953 	xprt_wake_pending_tasks(xprt, status);
1954 	return status;
1955 }
1956 
xs_local_connect(struct rpc_xprt * xprt,struct rpc_task * task)1957 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1958 {
1959 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1960 	int ret;
1961 
1962 	 if (RPC_IS_ASYNC(task)) {
1963 		/*
1964 		 * We want the AF_LOCAL connect to be resolved in the
1965 		 * filesystem namespace of the process making the rpc
1966 		 * call.  Thus we connect synchronously.
1967 		 *
1968 		 * If we want to support asynchronous AF_LOCAL calls,
1969 		 * we'll need to figure out how to pass a namespace to
1970 		 * connect.
1971 		 */
1972 		task->tk_rpc_status = -ENOTCONN;
1973 		rpc_exit(task, -ENOTCONN);
1974 		return;
1975 	}
1976 	ret = xs_local_setup_socket(transport);
1977 	if (ret && !RPC_IS_SOFTCONN(task))
1978 		msleep_interruptible(15000);
1979 }
1980 
1981 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1982 /*
1983  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1984  * know that we have exclusive access to the socket), to guard against
1985  * races with xs_reset_transport.
1986  */
xs_set_memalloc(struct rpc_xprt * xprt)1987 static void xs_set_memalloc(struct rpc_xprt *xprt)
1988 {
1989 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1990 			xprt);
1991 
1992 	/*
1993 	 * If there's no sock, then we have nothing to set. The
1994 	 * reconnecting process will get it for us.
1995 	 */
1996 	if (!transport->inet)
1997 		return;
1998 	if (atomic_read(&xprt->swapper))
1999 		sk_set_memalloc(transport->inet);
2000 }
2001 
2002 /**
2003  * xs_enable_swap - Tag this transport as being used for swap.
2004  * @xprt: transport to tag
2005  *
2006  * Take a reference to this transport on behalf of the rpc_clnt, and
2007  * optionally mark it for swapping if it wasn't already.
2008  */
2009 static int
xs_enable_swap(struct rpc_xprt * xprt)2010 xs_enable_swap(struct rpc_xprt *xprt)
2011 {
2012 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2013 
2014 	if (atomic_inc_return(&xprt->swapper) != 1)
2015 		return 0;
2016 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2017 		return -ERESTARTSYS;
2018 	if (xs->inet)
2019 		sk_set_memalloc(xs->inet);
2020 	xprt_release_xprt(xprt, NULL);
2021 	return 0;
2022 }
2023 
2024 /**
2025  * xs_disable_swap - Untag this transport as being used for swap.
2026  * @xprt: transport to tag
2027  *
2028  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2029  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2030  */
2031 static void
xs_disable_swap(struct rpc_xprt * xprt)2032 xs_disable_swap(struct rpc_xprt *xprt)
2033 {
2034 	struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2035 
2036 	if (!atomic_dec_and_test(&xprt->swapper))
2037 		return;
2038 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2039 		return;
2040 	if (xs->inet)
2041 		sk_clear_memalloc(xs->inet);
2042 	xprt_release_xprt(xprt, NULL);
2043 }
2044 #else
xs_set_memalloc(struct rpc_xprt * xprt)2045 static void xs_set_memalloc(struct rpc_xprt *xprt)
2046 {
2047 }
2048 
2049 static int
xs_enable_swap(struct rpc_xprt * xprt)2050 xs_enable_swap(struct rpc_xprt *xprt)
2051 {
2052 	return -EINVAL;
2053 }
2054 
2055 static void
xs_disable_swap(struct rpc_xprt * xprt)2056 xs_disable_swap(struct rpc_xprt *xprt)
2057 {
2058 }
2059 #endif
2060 
xs_udp_finish_connecting(struct rpc_xprt * xprt,struct socket * sock)2061 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2062 {
2063 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2064 
2065 	if (!transport->inet) {
2066 		struct sock *sk = sock->sk;
2067 
2068 		write_lock_bh(&sk->sk_callback_lock);
2069 
2070 		xs_save_old_callbacks(transport, sk);
2071 
2072 		sk->sk_user_data = xprt;
2073 		sk->sk_data_ready = xs_data_ready;
2074 		sk->sk_write_space = xs_udp_write_space;
2075 		sock_set_flag(sk, SOCK_FASYNC);
2076 
2077 		xprt_set_connected(xprt);
2078 
2079 		/* Reset to new socket */
2080 		transport->sock = sock;
2081 		transport->inet = sk;
2082 
2083 		xs_set_memalloc(xprt);
2084 
2085 		write_unlock_bh(&sk->sk_callback_lock);
2086 	}
2087 	xs_udp_do_set_buffer_size(xprt);
2088 
2089 	xprt->stat.connect_start = jiffies;
2090 }
2091 
xs_udp_setup_socket(struct work_struct * work)2092 static void xs_udp_setup_socket(struct work_struct *work)
2093 {
2094 	struct sock_xprt *transport =
2095 		container_of(work, struct sock_xprt, connect_worker.work);
2096 	struct rpc_xprt *xprt = &transport->xprt;
2097 	struct socket *sock;
2098 	int status = -EIO;
2099 
2100 	sock = xs_create_sock(xprt, transport,
2101 			xs_addr(xprt)->sa_family, SOCK_DGRAM,
2102 			IPPROTO_UDP, false);
2103 	if (IS_ERR(sock))
2104 		goto out;
2105 
2106 	dprintk("RPC:       worker connecting xprt %p via %s to "
2107 				"%s (port %s)\n", xprt,
2108 			xprt->address_strings[RPC_DISPLAY_PROTO],
2109 			xprt->address_strings[RPC_DISPLAY_ADDR],
2110 			xprt->address_strings[RPC_DISPLAY_PORT]);
2111 
2112 	xs_udp_finish_connecting(xprt, sock);
2113 	trace_rpc_socket_connect(xprt, sock, 0);
2114 	status = 0;
2115 out:
2116 	xprt_clear_connecting(xprt);
2117 	xprt_unlock_connect(xprt, transport);
2118 	xprt_wake_pending_tasks(xprt, status);
2119 }
2120 
2121 /**
2122  * xs_tcp_shutdown - gracefully shut down a TCP socket
2123  * @xprt: transport
2124  *
2125  * Initiates a graceful shutdown of the TCP socket by calling the
2126  * equivalent of shutdown(SHUT_RDWR);
2127  */
xs_tcp_shutdown(struct rpc_xprt * xprt)2128 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2129 {
2130 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2131 	struct socket *sock = transport->sock;
2132 	int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2133 
2134 	if (sock == NULL)
2135 		return;
2136 	if (!xprt->reuseport) {
2137 		xs_close(xprt);
2138 		return;
2139 	}
2140 	switch (skst) {
2141 	case TCP_FIN_WAIT1:
2142 	case TCP_FIN_WAIT2:
2143 	case TCP_LAST_ACK:
2144 		break;
2145 	case TCP_ESTABLISHED:
2146 	case TCP_CLOSE_WAIT:
2147 		kernel_sock_shutdown(sock, SHUT_RDWR);
2148 		trace_rpc_socket_shutdown(xprt, sock);
2149 		break;
2150 	default:
2151 		xs_reset_transport(transport);
2152 	}
2153 }
2154 
xs_tcp_set_socket_timeouts(struct rpc_xprt * xprt,struct socket * sock)2155 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2156 		struct socket *sock)
2157 {
2158 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2159 	unsigned int keepidle;
2160 	unsigned int keepcnt;
2161 	unsigned int timeo;
2162 
2163 	spin_lock(&xprt->transport_lock);
2164 	keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2165 	keepcnt = xprt->timeout->to_retries + 1;
2166 	timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2167 		(xprt->timeout->to_retries + 1);
2168 	clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2169 	spin_unlock(&xprt->transport_lock);
2170 
2171 	/* TCP Keepalive options */
2172 	sock_set_keepalive(sock->sk);
2173 	tcp_sock_set_keepidle(sock->sk, keepidle);
2174 	tcp_sock_set_keepintvl(sock->sk, keepidle);
2175 	tcp_sock_set_keepcnt(sock->sk, keepcnt);
2176 
2177 	/* TCP user timeout (see RFC5482) */
2178 	tcp_sock_set_user_timeout(sock->sk, timeo);
2179 }
2180 
xs_tcp_set_connect_timeout(struct rpc_xprt * xprt,unsigned long connect_timeout,unsigned long reconnect_timeout)2181 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2182 		unsigned long connect_timeout,
2183 		unsigned long reconnect_timeout)
2184 {
2185 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2186 	struct rpc_timeout to;
2187 	unsigned long initval;
2188 
2189 	spin_lock(&xprt->transport_lock);
2190 	if (reconnect_timeout < xprt->max_reconnect_timeout)
2191 		xprt->max_reconnect_timeout = reconnect_timeout;
2192 	if (connect_timeout < xprt->connect_timeout) {
2193 		memcpy(&to, xprt->timeout, sizeof(to));
2194 		initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2195 		/* Arbitrary lower limit */
2196 		if (initval <  XS_TCP_INIT_REEST_TO << 1)
2197 			initval = XS_TCP_INIT_REEST_TO << 1;
2198 		to.to_initval = initval;
2199 		to.to_maxval = initval;
2200 		memcpy(&transport->tcp_timeout, &to,
2201 				sizeof(transport->tcp_timeout));
2202 		xprt->timeout = &transport->tcp_timeout;
2203 		xprt->connect_timeout = connect_timeout;
2204 	}
2205 	set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2206 	spin_unlock(&xprt->transport_lock);
2207 }
2208 
xs_tcp_finish_connecting(struct rpc_xprt * xprt,struct socket * sock)2209 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2210 {
2211 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2212 	int ret = -ENOTCONN;
2213 
2214 	if (!transport->inet) {
2215 		struct sock *sk = sock->sk;
2216 
2217 		/* Avoid temporary address, they are bad for long-lived
2218 		 * connections such as NFS mounts.
2219 		 * RFC4941, section 3.6 suggests that:
2220 		 *    Individual applications, which have specific
2221 		 *    knowledge about the normal duration of connections,
2222 		 *    MAY override this as appropriate.
2223 		 */
2224 		if (xs_addr(xprt)->sa_family == PF_INET6) {
2225 			ip6_sock_set_addr_preferences(sk,
2226 				IPV6_PREFER_SRC_PUBLIC);
2227 		}
2228 
2229 		xs_tcp_set_socket_timeouts(xprt, sock);
2230 		tcp_sock_set_nodelay(sk);
2231 
2232 		write_lock_bh(&sk->sk_callback_lock);
2233 
2234 		xs_save_old_callbacks(transport, sk);
2235 
2236 		sk->sk_user_data = xprt;
2237 		sk->sk_data_ready = xs_data_ready;
2238 		sk->sk_state_change = xs_tcp_state_change;
2239 		sk->sk_write_space = xs_tcp_write_space;
2240 		sock_set_flag(sk, SOCK_FASYNC);
2241 		sk->sk_error_report = xs_error_report;
2242 
2243 		/* socket options */
2244 		sock_reset_flag(sk, SOCK_LINGER);
2245 
2246 		xprt_clear_connected(xprt);
2247 
2248 		/* Reset to new socket */
2249 		transport->sock = sock;
2250 		transport->inet = sk;
2251 
2252 		write_unlock_bh(&sk->sk_callback_lock);
2253 	}
2254 
2255 	if (!xprt_bound(xprt))
2256 		goto out;
2257 
2258 	xs_set_memalloc(xprt);
2259 
2260 	xs_stream_start_connect(transport);
2261 
2262 	/* Tell the socket layer to start connecting... */
2263 	set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2264 	ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2265 	switch (ret) {
2266 	case 0:
2267 		xs_set_srcport(transport, sock);
2268 		fallthrough;
2269 	case -EINPROGRESS:
2270 		/* SYN_SENT! */
2271 		set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state);
2272 		if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2273 			xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2274 		break;
2275 	case -EADDRNOTAVAIL:
2276 		/* Source port number is unavailable. Try a new one! */
2277 		transport->srcport = 0;
2278 	}
2279 out:
2280 	return ret;
2281 }
2282 
2283 /**
2284  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2285  * @work: queued work item
2286  *
2287  * Invoked by a work queue tasklet.
2288  */
xs_tcp_setup_socket(struct work_struct * work)2289 static void xs_tcp_setup_socket(struct work_struct *work)
2290 {
2291 	struct sock_xprt *transport =
2292 		container_of(work, struct sock_xprt, connect_worker.work);
2293 	struct socket *sock = transport->sock;
2294 	struct rpc_xprt *xprt = &transport->xprt;
2295 	int status = -EIO;
2296 
2297 	if (xprt_connected(xprt))
2298 		goto out;
2299 	if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT,
2300 			       &transport->sock_state) ||
2301 	    !sock) {
2302 		xs_reset_transport(transport);
2303 		sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family,
2304 				      SOCK_STREAM, IPPROTO_TCP, true);
2305 		if (IS_ERR(sock)) {
2306 			status = PTR_ERR(sock);
2307 			goto out;
2308 		}
2309 	}
2310 
2311 	dprintk("RPC:       worker connecting xprt %p via %s to "
2312 				"%s (port %s)\n", xprt,
2313 			xprt->address_strings[RPC_DISPLAY_PROTO],
2314 			xprt->address_strings[RPC_DISPLAY_ADDR],
2315 			xprt->address_strings[RPC_DISPLAY_PORT]);
2316 
2317 	status = xs_tcp_finish_connecting(xprt, sock);
2318 	trace_rpc_socket_connect(xprt, sock, status);
2319 	dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2320 			xprt, -status, xprt_connected(xprt),
2321 			sock->sk->sk_state);
2322 	switch (status) {
2323 	default:
2324 		printk("%s: connect returned unhandled error %d\n",
2325 			__func__, status);
2326 		fallthrough;
2327 	case -EADDRNOTAVAIL:
2328 		/* We're probably in TIME_WAIT. Get rid of existing socket,
2329 		 * and retry
2330 		 */
2331 		xs_tcp_force_close(xprt);
2332 		break;
2333 	case 0:
2334 	case -EINPROGRESS:
2335 	case -EALREADY:
2336 		xprt_unlock_connect(xprt, transport);
2337 		return;
2338 	case -EINVAL:
2339 		/* Happens, for instance, if the user specified a link
2340 		 * local IPv6 address without a scope-id.
2341 		 */
2342 	case -ECONNREFUSED:
2343 	case -ECONNRESET:
2344 	case -ENETDOWN:
2345 	case -ENETUNREACH:
2346 	case -EHOSTUNREACH:
2347 	case -EADDRINUSE:
2348 	case -ENOBUFS:
2349 		/* xs_tcp_force_close() wakes tasks with a fixed error code.
2350 		 * We need to wake them first to ensure the correct error code.
2351 		 */
2352 		xprt_wake_pending_tasks(xprt, status);
2353 		xs_tcp_force_close(xprt);
2354 		goto out;
2355 	}
2356 	status = -EAGAIN;
2357 out:
2358 	xprt_clear_connecting(xprt);
2359 	xprt_unlock_connect(xprt, transport);
2360 	xprt_wake_pending_tasks(xprt, status);
2361 }
2362 
2363 /**
2364  * xs_connect - connect a socket to a remote endpoint
2365  * @xprt: pointer to transport structure
2366  * @task: address of RPC task that manages state of connect request
2367  *
2368  * TCP: If the remote end dropped the connection, delay reconnecting.
2369  *
2370  * UDP socket connects are synchronous, but we use a work queue anyway
2371  * to guarantee that even unprivileged user processes can set up a
2372  * socket on a privileged port.
2373  *
2374  * If a UDP socket connect fails, the delay behavior here prevents
2375  * retry floods (hard mounts).
2376  */
xs_connect(struct rpc_xprt * xprt,struct rpc_task * task)2377 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2378 {
2379 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2380 	unsigned long delay = 0;
2381 
2382 	WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2383 
2384 	if (transport->sock != NULL) {
2385 		dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2386 			"seconds\n", xprt, xprt->reestablish_timeout / HZ);
2387 
2388 		delay = xprt_reconnect_delay(xprt);
2389 		xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2390 
2391 	} else
2392 		dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2393 
2394 	queue_delayed_work(xprtiod_workqueue,
2395 			&transport->connect_worker,
2396 			delay);
2397 }
2398 
xs_wake_disconnect(struct sock_xprt * transport)2399 static void xs_wake_disconnect(struct sock_xprt *transport)
2400 {
2401 	if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2402 		xs_tcp_force_close(&transport->xprt);
2403 }
2404 
xs_wake_write(struct sock_xprt * transport)2405 static void xs_wake_write(struct sock_xprt *transport)
2406 {
2407 	if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2408 		xprt_write_space(&transport->xprt);
2409 }
2410 
xs_wake_error(struct sock_xprt * transport)2411 static void xs_wake_error(struct sock_xprt *transport)
2412 {
2413 	int sockerr;
2414 
2415 	if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2416 		return;
2417 	mutex_lock(&transport->recv_mutex);
2418 	if (transport->sock == NULL)
2419 		goto out;
2420 	if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2421 		goto out;
2422 	sockerr = xchg(&transport->xprt_err, 0);
2423 	if (sockerr < 0)
2424 		xprt_wake_pending_tasks(&transport->xprt, sockerr);
2425 out:
2426 	mutex_unlock(&transport->recv_mutex);
2427 }
2428 
xs_wake_pending(struct sock_xprt * transport)2429 static void xs_wake_pending(struct sock_xprt *transport)
2430 {
2431 	if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2432 		xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2433 }
2434 
xs_error_handle(struct work_struct * work)2435 static void xs_error_handle(struct work_struct *work)
2436 {
2437 	struct sock_xprt *transport = container_of(work,
2438 			struct sock_xprt, error_worker);
2439 
2440 	xs_wake_disconnect(transport);
2441 	xs_wake_write(transport);
2442 	xs_wake_error(transport);
2443 	xs_wake_pending(transport);
2444 }
2445 
2446 /**
2447  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2448  * @xprt: rpc_xprt struct containing statistics
2449  * @seq: output file
2450  *
2451  */
xs_local_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)2452 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2453 {
2454 	long idle_time = 0;
2455 
2456 	if (xprt_connected(xprt))
2457 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2458 
2459 	seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2460 			"%llu %llu %lu %llu %llu\n",
2461 			xprt->stat.bind_count,
2462 			xprt->stat.connect_count,
2463 			xprt->stat.connect_time / HZ,
2464 			idle_time,
2465 			xprt->stat.sends,
2466 			xprt->stat.recvs,
2467 			xprt->stat.bad_xids,
2468 			xprt->stat.req_u,
2469 			xprt->stat.bklog_u,
2470 			xprt->stat.max_slots,
2471 			xprt->stat.sending_u,
2472 			xprt->stat.pending_u);
2473 }
2474 
2475 /**
2476  * xs_udp_print_stats - display UDP socket-specific stats
2477  * @xprt: rpc_xprt struct containing statistics
2478  * @seq: output file
2479  *
2480  */
xs_udp_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)2481 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2482 {
2483 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2484 
2485 	seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2486 			"%lu %llu %llu\n",
2487 			transport->srcport,
2488 			xprt->stat.bind_count,
2489 			xprt->stat.sends,
2490 			xprt->stat.recvs,
2491 			xprt->stat.bad_xids,
2492 			xprt->stat.req_u,
2493 			xprt->stat.bklog_u,
2494 			xprt->stat.max_slots,
2495 			xprt->stat.sending_u,
2496 			xprt->stat.pending_u);
2497 }
2498 
2499 /**
2500  * xs_tcp_print_stats - display TCP socket-specific stats
2501  * @xprt: rpc_xprt struct containing statistics
2502  * @seq: output file
2503  *
2504  */
xs_tcp_print_stats(struct rpc_xprt * xprt,struct seq_file * seq)2505 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2506 {
2507 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2508 	long idle_time = 0;
2509 
2510 	if (xprt_connected(xprt))
2511 		idle_time = (long)(jiffies - xprt->last_used) / HZ;
2512 
2513 	seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2514 			"%llu %llu %lu %llu %llu\n",
2515 			transport->srcport,
2516 			xprt->stat.bind_count,
2517 			xprt->stat.connect_count,
2518 			xprt->stat.connect_time / HZ,
2519 			idle_time,
2520 			xprt->stat.sends,
2521 			xprt->stat.recvs,
2522 			xprt->stat.bad_xids,
2523 			xprt->stat.req_u,
2524 			xprt->stat.bklog_u,
2525 			xprt->stat.max_slots,
2526 			xprt->stat.sending_u,
2527 			xprt->stat.pending_u);
2528 }
2529 
2530 /*
2531  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2532  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2533  * to use the server side send routines.
2534  */
bc_malloc(struct rpc_task * task)2535 static int bc_malloc(struct rpc_task *task)
2536 {
2537 	struct rpc_rqst *rqst = task->tk_rqstp;
2538 	size_t size = rqst->rq_callsize;
2539 	struct page *page;
2540 	struct rpc_buffer *buf;
2541 
2542 	if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2543 		WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2544 			  size);
2545 		return -EINVAL;
2546 	}
2547 
2548 	page = alloc_page(GFP_KERNEL);
2549 	if (!page)
2550 		return -ENOMEM;
2551 
2552 	buf = page_address(page);
2553 	buf->len = PAGE_SIZE;
2554 
2555 	rqst->rq_buffer = buf->data;
2556 	rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2557 	return 0;
2558 }
2559 
2560 /*
2561  * Free the space allocated in the bc_alloc routine
2562  */
bc_free(struct rpc_task * task)2563 static void bc_free(struct rpc_task *task)
2564 {
2565 	void *buffer = task->tk_rqstp->rq_buffer;
2566 	struct rpc_buffer *buf;
2567 
2568 	buf = container_of(buffer, struct rpc_buffer, data);
2569 	free_page((unsigned long)buf);
2570 }
2571 
bc_sendto(struct rpc_rqst * req)2572 static int bc_sendto(struct rpc_rqst *req)
2573 {
2574 	struct xdr_buf *xdr = &req->rq_snd_buf;
2575 	struct sock_xprt *transport =
2576 			container_of(req->rq_xprt, struct sock_xprt, xprt);
2577 	struct msghdr msg = {
2578 		.msg_flags	= 0,
2579 	};
2580 	rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2581 					 (u32)xdr->len);
2582 	unsigned int sent = 0;
2583 	int err;
2584 
2585 	req->rq_xtime = ktime_get();
2586 	err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2587 	xdr_free_bvec(xdr);
2588 	if (err < 0 || sent != (xdr->len + sizeof(marker)))
2589 		return -EAGAIN;
2590 	return sent;
2591 }
2592 
2593 /**
2594  * bc_send_request - Send a backchannel Call on a TCP socket
2595  * @req: rpc_rqst containing Call message to be sent
2596  *
2597  * xpt_mutex ensures @rqstp's whole message is written to the socket
2598  * without interruption.
2599  *
2600  * Return values:
2601  *   %0 if the message was sent successfully
2602  *   %ENOTCONN if the message was not sent
2603  */
bc_send_request(struct rpc_rqst * req)2604 static int bc_send_request(struct rpc_rqst *req)
2605 {
2606 	struct svc_xprt	*xprt;
2607 	int len;
2608 
2609 	/*
2610 	 * Get the server socket associated with this callback xprt
2611 	 */
2612 	xprt = req->rq_xprt->bc_xprt;
2613 
2614 	/*
2615 	 * Grab the mutex to serialize data as the connection is shared
2616 	 * with the fore channel
2617 	 */
2618 	mutex_lock(&xprt->xpt_mutex);
2619 	if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2620 		len = -ENOTCONN;
2621 	else
2622 		len = bc_sendto(req);
2623 	mutex_unlock(&xprt->xpt_mutex);
2624 
2625 	if (len > 0)
2626 		len = 0;
2627 
2628 	return len;
2629 }
2630 
2631 /*
2632  * The close routine. Since this is client initiated, we do nothing
2633  */
2634 
bc_close(struct rpc_xprt * xprt)2635 static void bc_close(struct rpc_xprt *xprt)
2636 {
2637 	xprt_disconnect_done(xprt);
2638 }
2639 
2640 /*
2641  * The xprt destroy routine. Again, because this connection is client
2642  * initiated, we do nothing
2643  */
2644 
bc_destroy(struct rpc_xprt * xprt)2645 static void bc_destroy(struct rpc_xprt *xprt)
2646 {
2647 	dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2648 
2649 	xs_xprt_free(xprt);
2650 	module_put(THIS_MODULE);
2651 }
2652 
2653 static const struct rpc_xprt_ops xs_local_ops = {
2654 	.reserve_xprt		= xprt_reserve_xprt,
2655 	.release_xprt		= xprt_release_xprt,
2656 	.alloc_slot		= xprt_alloc_slot,
2657 	.free_slot		= xprt_free_slot,
2658 	.rpcbind		= xs_local_rpcbind,
2659 	.set_port		= xs_local_set_port,
2660 	.connect		= xs_local_connect,
2661 	.buf_alloc		= rpc_malloc,
2662 	.buf_free		= rpc_free,
2663 	.prepare_request	= xs_stream_prepare_request,
2664 	.send_request		= xs_local_send_request,
2665 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2666 	.close			= xs_close,
2667 	.destroy		= xs_destroy,
2668 	.print_stats		= xs_local_print_stats,
2669 	.enable_swap		= xs_enable_swap,
2670 	.disable_swap		= xs_disable_swap,
2671 };
2672 
2673 static const struct rpc_xprt_ops xs_udp_ops = {
2674 	.set_buffer_size	= xs_udp_set_buffer_size,
2675 	.reserve_xprt		= xprt_reserve_xprt_cong,
2676 	.release_xprt		= xprt_release_xprt_cong,
2677 	.alloc_slot		= xprt_alloc_slot,
2678 	.free_slot		= xprt_free_slot,
2679 	.rpcbind		= rpcb_getport_async,
2680 	.set_port		= xs_set_port,
2681 	.connect		= xs_connect,
2682 	.buf_alloc		= rpc_malloc,
2683 	.buf_free		= rpc_free,
2684 	.send_request		= xs_udp_send_request,
2685 	.wait_for_reply_request	= xprt_wait_for_reply_request_rtt,
2686 	.timer			= xs_udp_timer,
2687 	.release_request	= xprt_release_rqst_cong,
2688 	.close			= xs_close,
2689 	.destroy		= xs_destroy,
2690 	.print_stats		= xs_udp_print_stats,
2691 	.enable_swap		= xs_enable_swap,
2692 	.disable_swap		= xs_disable_swap,
2693 	.inject_disconnect	= xs_inject_disconnect,
2694 };
2695 
2696 static const struct rpc_xprt_ops xs_tcp_ops = {
2697 	.reserve_xprt		= xprt_reserve_xprt,
2698 	.release_xprt		= xprt_release_xprt,
2699 	.alloc_slot		= xprt_alloc_slot,
2700 	.free_slot		= xprt_free_slot,
2701 	.rpcbind		= rpcb_getport_async,
2702 	.set_port		= xs_set_port,
2703 	.connect		= xs_connect,
2704 	.buf_alloc		= rpc_malloc,
2705 	.buf_free		= rpc_free,
2706 	.prepare_request	= xs_stream_prepare_request,
2707 	.send_request		= xs_tcp_send_request,
2708 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2709 	.close			= xs_tcp_shutdown,
2710 	.destroy		= xs_destroy,
2711 	.set_connect_timeout	= xs_tcp_set_connect_timeout,
2712 	.print_stats		= xs_tcp_print_stats,
2713 	.enable_swap		= xs_enable_swap,
2714 	.disable_swap		= xs_disable_swap,
2715 	.inject_disconnect	= xs_inject_disconnect,
2716 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2717 	.bc_setup		= xprt_setup_bc,
2718 	.bc_maxpayload		= xs_tcp_bc_maxpayload,
2719 	.bc_num_slots		= xprt_bc_max_slots,
2720 	.bc_free_rqst		= xprt_free_bc_rqst,
2721 	.bc_destroy		= xprt_destroy_bc,
2722 #endif
2723 };
2724 
2725 /*
2726  * The rpc_xprt_ops for the server backchannel
2727  */
2728 
2729 static const struct rpc_xprt_ops bc_tcp_ops = {
2730 	.reserve_xprt		= xprt_reserve_xprt,
2731 	.release_xprt		= xprt_release_xprt,
2732 	.alloc_slot		= xprt_alloc_slot,
2733 	.free_slot		= xprt_free_slot,
2734 	.buf_alloc		= bc_malloc,
2735 	.buf_free		= bc_free,
2736 	.send_request		= bc_send_request,
2737 	.wait_for_reply_request	= xprt_wait_for_reply_request_def,
2738 	.close			= bc_close,
2739 	.destroy		= bc_destroy,
2740 	.print_stats		= xs_tcp_print_stats,
2741 	.enable_swap		= xs_enable_swap,
2742 	.disable_swap		= xs_disable_swap,
2743 	.inject_disconnect	= xs_inject_disconnect,
2744 };
2745 
xs_init_anyaddr(const int family,struct sockaddr * sap)2746 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2747 {
2748 	static const struct sockaddr_in sin = {
2749 		.sin_family		= AF_INET,
2750 		.sin_addr.s_addr	= htonl(INADDR_ANY),
2751 	};
2752 	static const struct sockaddr_in6 sin6 = {
2753 		.sin6_family		= AF_INET6,
2754 		.sin6_addr		= IN6ADDR_ANY_INIT,
2755 	};
2756 
2757 	switch (family) {
2758 	case AF_LOCAL:
2759 		break;
2760 	case AF_INET:
2761 		memcpy(sap, &sin, sizeof(sin));
2762 		break;
2763 	case AF_INET6:
2764 		memcpy(sap, &sin6, sizeof(sin6));
2765 		break;
2766 	default:
2767 		dprintk("RPC:       %s: Bad address family\n", __func__);
2768 		return -EAFNOSUPPORT;
2769 	}
2770 	return 0;
2771 }
2772 
xs_setup_xprt(struct xprt_create * args,unsigned int slot_table_size,unsigned int max_slot_table_size)2773 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2774 				      unsigned int slot_table_size,
2775 				      unsigned int max_slot_table_size)
2776 {
2777 	struct rpc_xprt *xprt;
2778 	struct sock_xprt *new;
2779 
2780 	if (args->addrlen > sizeof(xprt->addr)) {
2781 		dprintk("RPC:       xs_setup_xprt: address too large\n");
2782 		return ERR_PTR(-EBADF);
2783 	}
2784 
2785 	xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2786 			max_slot_table_size);
2787 	if (xprt == NULL) {
2788 		dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2789 				"rpc_xprt\n");
2790 		return ERR_PTR(-ENOMEM);
2791 	}
2792 
2793 	new = container_of(xprt, struct sock_xprt, xprt);
2794 	mutex_init(&new->recv_mutex);
2795 	memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2796 	xprt->addrlen = args->addrlen;
2797 	if (args->srcaddr)
2798 		memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2799 	else {
2800 		int err;
2801 		err = xs_init_anyaddr(args->dstaddr->sa_family,
2802 					(struct sockaddr *)&new->srcaddr);
2803 		if (err != 0) {
2804 			xprt_free(xprt);
2805 			return ERR_PTR(err);
2806 		}
2807 	}
2808 
2809 	return xprt;
2810 }
2811 
2812 static const struct rpc_timeout xs_local_default_timeout = {
2813 	.to_initval = 10 * HZ,
2814 	.to_maxval = 10 * HZ,
2815 	.to_retries = 2,
2816 };
2817 
2818 /**
2819  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2820  * @args: rpc transport creation arguments
2821  *
2822  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2823  */
xs_setup_local(struct xprt_create * args)2824 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2825 {
2826 	struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2827 	struct sock_xprt *transport;
2828 	struct rpc_xprt *xprt;
2829 	struct rpc_xprt *ret;
2830 
2831 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2832 			xprt_max_tcp_slot_table_entries);
2833 	if (IS_ERR(xprt))
2834 		return xprt;
2835 	transport = container_of(xprt, struct sock_xprt, xprt);
2836 
2837 	xprt->prot = 0;
2838 	xprt->xprt_class = &xs_local_transport;
2839 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2840 
2841 	xprt->bind_timeout = XS_BIND_TO;
2842 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2843 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2844 
2845 	xprt->ops = &xs_local_ops;
2846 	xprt->timeout = &xs_local_default_timeout;
2847 
2848 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2849 	INIT_WORK(&transport->error_worker, xs_error_handle);
2850 	INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2851 
2852 	switch (sun->sun_family) {
2853 	case AF_LOCAL:
2854 		if (sun->sun_path[0] != '/') {
2855 			dprintk("RPC:       bad AF_LOCAL address: %s\n",
2856 					sun->sun_path);
2857 			ret = ERR_PTR(-EINVAL);
2858 			goto out_err;
2859 		}
2860 		xprt_set_bound(xprt);
2861 		xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2862 		break;
2863 	default:
2864 		ret = ERR_PTR(-EAFNOSUPPORT);
2865 		goto out_err;
2866 	}
2867 
2868 	dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2869 			xprt->address_strings[RPC_DISPLAY_ADDR]);
2870 
2871 	if (try_module_get(THIS_MODULE))
2872 		return xprt;
2873 	ret = ERR_PTR(-EINVAL);
2874 out_err:
2875 	xs_xprt_free(xprt);
2876 	return ret;
2877 }
2878 
2879 static const struct rpc_timeout xs_udp_default_timeout = {
2880 	.to_initval = 5 * HZ,
2881 	.to_maxval = 30 * HZ,
2882 	.to_increment = 5 * HZ,
2883 	.to_retries = 5,
2884 };
2885 
2886 /**
2887  * xs_setup_udp - Set up transport to use a UDP socket
2888  * @args: rpc transport creation arguments
2889  *
2890  */
xs_setup_udp(struct xprt_create * args)2891 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2892 {
2893 	struct sockaddr *addr = args->dstaddr;
2894 	struct rpc_xprt *xprt;
2895 	struct sock_xprt *transport;
2896 	struct rpc_xprt *ret;
2897 
2898 	xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2899 			xprt_udp_slot_table_entries);
2900 	if (IS_ERR(xprt))
2901 		return xprt;
2902 	transport = container_of(xprt, struct sock_xprt, xprt);
2903 
2904 	xprt->prot = IPPROTO_UDP;
2905 	xprt->xprt_class = &xs_udp_transport;
2906 	/* XXX: header size can vary due to auth type, IPv6, etc. */
2907 	xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2908 
2909 	xprt->bind_timeout = XS_BIND_TO;
2910 	xprt->reestablish_timeout = XS_UDP_REEST_TO;
2911 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2912 
2913 	xprt->ops = &xs_udp_ops;
2914 
2915 	xprt->timeout = &xs_udp_default_timeout;
2916 
2917 	INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2918 	INIT_WORK(&transport->error_worker, xs_error_handle);
2919 	INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2920 
2921 	switch (addr->sa_family) {
2922 	case AF_INET:
2923 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2924 			xprt_set_bound(xprt);
2925 
2926 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2927 		break;
2928 	case AF_INET6:
2929 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2930 			xprt_set_bound(xprt);
2931 
2932 		xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2933 		break;
2934 	default:
2935 		ret = ERR_PTR(-EAFNOSUPPORT);
2936 		goto out_err;
2937 	}
2938 
2939 	if (xprt_bound(xprt))
2940 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2941 				xprt->address_strings[RPC_DISPLAY_ADDR],
2942 				xprt->address_strings[RPC_DISPLAY_PORT],
2943 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2944 	else
2945 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2946 				xprt->address_strings[RPC_DISPLAY_ADDR],
2947 				xprt->address_strings[RPC_DISPLAY_PROTO]);
2948 
2949 	if (try_module_get(THIS_MODULE))
2950 		return xprt;
2951 	ret = ERR_PTR(-EINVAL);
2952 out_err:
2953 	xs_xprt_free(xprt);
2954 	return ret;
2955 }
2956 
2957 static const struct rpc_timeout xs_tcp_default_timeout = {
2958 	.to_initval = 60 * HZ,
2959 	.to_maxval = 60 * HZ,
2960 	.to_retries = 2,
2961 };
2962 
2963 /**
2964  * xs_setup_tcp - Set up transport to use a TCP socket
2965  * @args: rpc transport creation arguments
2966  *
2967  */
xs_setup_tcp(struct xprt_create * args)2968 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2969 {
2970 	struct sockaddr *addr = args->dstaddr;
2971 	struct rpc_xprt *xprt;
2972 	struct sock_xprt *transport;
2973 	struct rpc_xprt *ret;
2974 	unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2975 
2976 	if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2977 		max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2978 
2979 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2980 			max_slot_table_size);
2981 	if (IS_ERR(xprt))
2982 		return xprt;
2983 	transport = container_of(xprt, struct sock_xprt, xprt);
2984 
2985 	xprt->prot = IPPROTO_TCP;
2986 	xprt->xprt_class = &xs_tcp_transport;
2987 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2988 
2989 	xprt->bind_timeout = XS_BIND_TO;
2990 	xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2991 	xprt->idle_timeout = XS_IDLE_DISC_TO;
2992 
2993 	xprt->ops = &xs_tcp_ops;
2994 	xprt->timeout = &xs_tcp_default_timeout;
2995 
2996 	xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2997 	xprt->connect_timeout = xprt->timeout->to_initval *
2998 		(xprt->timeout->to_retries + 1);
2999 
3000 	INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
3001 	INIT_WORK(&transport->error_worker, xs_error_handle);
3002 	INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3003 
3004 	switch (addr->sa_family) {
3005 	case AF_INET:
3006 		if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3007 			xprt_set_bound(xprt);
3008 
3009 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3010 		break;
3011 	case AF_INET6:
3012 		if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3013 			xprt_set_bound(xprt);
3014 
3015 		xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3016 		break;
3017 	default:
3018 		ret = ERR_PTR(-EAFNOSUPPORT);
3019 		goto out_err;
3020 	}
3021 
3022 	if (xprt_bound(xprt))
3023 		dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3024 				xprt->address_strings[RPC_DISPLAY_ADDR],
3025 				xprt->address_strings[RPC_DISPLAY_PORT],
3026 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3027 	else
3028 		dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3029 				xprt->address_strings[RPC_DISPLAY_ADDR],
3030 				xprt->address_strings[RPC_DISPLAY_PROTO]);
3031 
3032 	if (try_module_get(THIS_MODULE))
3033 		return xprt;
3034 	ret = ERR_PTR(-EINVAL);
3035 out_err:
3036 	xs_xprt_free(xprt);
3037 	return ret;
3038 }
3039 
3040 /**
3041  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3042  * @args: rpc transport creation arguments
3043  *
3044  */
xs_setup_bc_tcp(struct xprt_create * args)3045 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3046 {
3047 	struct sockaddr *addr = args->dstaddr;
3048 	struct rpc_xprt *xprt;
3049 	struct sock_xprt *transport;
3050 	struct svc_sock *bc_sock;
3051 	struct rpc_xprt *ret;
3052 
3053 	xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3054 			xprt_tcp_slot_table_entries);
3055 	if (IS_ERR(xprt))
3056 		return xprt;
3057 	transport = container_of(xprt, struct sock_xprt, xprt);
3058 
3059 	xprt->prot = IPPROTO_TCP;
3060 	xprt->xprt_class = &xs_bc_tcp_transport;
3061 	xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3062 	xprt->timeout = &xs_tcp_default_timeout;
3063 
3064 	/* backchannel */
3065 	xprt_set_bound(xprt);
3066 	xprt->bind_timeout = 0;
3067 	xprt->reestablish_timeout = 0;
3068 	xprt->idle_timeout = 0;
3069 
3070 	xprt->ops = &bc_tcp_ops;
3071 
3072 	switch (addr->sa_family) {
3073 	case AF_INET:
3074 		xs_format_peer_addresses(xprt, "tcp",
3075 					 RPCBIND_NETID_TCP);
3076 		break;
3077 	case AF_INET6:
3078 		xs_format_peer_addresses(xprt, "tcp",
3079 				   RPCBIND_NETID_TCP6);
3080 		break;
3081 	default:
3082 		ret = ERR_PTR(-EAFNOSUPPORT);
3083 		goto out_err;
3084 	}
3085 
3086 	dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3087 			xprt->address_strings[RPC_DISPLAY_ADDR],
3088 			xprt->address_strings[RPC_DISPLAY_PORT],
3089 			xprt->address_strings[RPC_DISPLAY_PROTO]);
3090 
3091 	/*
3092 	 * Once we've associated a backchannel xprt with a connection,
3093 	 * we want to keep it around as long as the connection lasts,
3094 	 * in case we need to start using it for a backchannel again;
3095 	 * this reference won't be dropped until bc_xprt is destroyed.
3096 	 */
3097 	xprt_get(xprt);
3098 	args->bc_xprt->xpt_bc_xprt = xprt;
3099 	xprt->bc_xprt = args->bc_xprt;
3100 	bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3101 	transport->sock = bc_sock->sk_sock;
3102 	transport->inet = bc_sock->sk_sk;
3103 
3104 	/*
3105 	 * Since we don't want connections for the backchannel, we set
3106 	 * the xprt status to connected
3107 	 */
3108 	xprt_set_connected(xprt);
3109 
3110 	if (try_module_get(THIS_MODULE))
3111 		return xprt;
3112 
3113 	args->bc_xprt->xpt_bc_xprt = NULL;
3114 	args->bc_xprt->xpt_bc_xps = NULL;
3115 	xprt_put(xprt);
3116 	ret = ERR_PTR(-EINVAL);
3117 out_err:
3118 	xs_xprt_free(xprt);
3119 	return ret;
3120 }
3121 
3122 static struct xprt_class	xs_local_transport = {
3123 	.list		= LIST_HEAD_INIT(xs_local_transport.list),
3124 	.name		= "named UNIX socket",
3125 	.owner		= THIS_MODULE,
3126 	.ident		= XPRT_TRANSPORT_LOCAL,
3127 	.setup		= xs_setup_local,
3128 	.netid		= { "" },
3129 };
3130 
3131 static struct xprt_class	xs_udp_transport = {
3132 	.list		= LIST_HEAD_INIT(xs_udp_transport.list),
3133 	.name		= "udp",
3134 	.owner		= THIS_MODULE,
3135 	.ident		= XPRT_TRANSPORT_UDP,
3136 	.setup		= xs_setup_udp,
3137 	.netid		= { "udp", "udp6", "" },
3138 };
3139 
3140 static struct xprt_class	xs_tcp_transport = {
3141 	.list		= LIST_HEAD_INIT(xs_tcp_transport.list),
3142 	.name		= "tcp",
3143 	.owner		= THIS_MODULE,
3144 	.ident		= XPRT_TRANSPORT_TCP,
3145 	.setup		= xs_setup_tcp,
3146 	.netid		= { "tcp", "tcp6", "" },
3147 };
3148 
3149 static struct xprt_class	xs_bc_tcp_transport = {
3150 	.list		= LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3151 	.name		= "tcp NFSv4.1 backchannel",
3152 	.owner		= THIS_MODULE,
3153 	.ident		= XPRT_TRANSPORT_BC_TCP,
3154 	.setup		= xs_setup_bc_tcp,
3155 	.netid		= { "" },
3156 };
3157 
3158 /**
3159  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3160  *
3161  */
init_socket_xprt(void)3162 int init_socket_xprt(void)
3163 {
3164 	if (!sunrpc_table_header)
3165 		sunrpc_table_header = register_sysctl_table(sunrpc_table);
3166 
3167 	xprt_register_transport(&xs_local_transport);
3168 	xprt_register_transport(&xs_udp_transport);
3169 	xprt_register_transport(&xs_tcp_transport);
3170 	xprt_register_transport(&xs_bc_tcp_transport);
3171 
3172 	return 0;
3173 }
3174 
3175 /**
3176  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3177  *
3178  */
cleanup_socket_xprt(void)3179 void cleanup_socket_xprt(void)
3180 {
3181 	if (sunrpc_table_header) {
3182 		unregister_sysctl_table(sunrpc_table_header);
3183 		sunrpc_table_header = NULL;
3184 	}
3185 
3186 	xprt_unregister_transport(&xs_local_transport);
3187 	xprt_unregister_transport(&xs_udp_transport);
3188 	xprt_unregister_transport(&xs_tcp_transport);
3189 	xprt_unregister_transport(&xs_bc_tcp_transport);
3190 }
3191 
param_set_portnr(const char * val,const struct kernel_param * kp)3192 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3193 {
3194 	return param_set_uint_minmax(val, kp,
3195 			RPC_MIN_RESVPORT,
3196 			RPC_MAX_RESVPORT);
3197 }
3198 
3199 static const struct kernel_param_ops param_ops_portnr = {
3200 	.set = param_set_portnr,
3201 	.get = param_get_uint,
3202 };
3203 
3204 #define param_check_portnr(name, p) \
3205 	__param_check(name, p, unsigned int);
3206 
3207 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3208 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3209 
param_set_slot_table_size(const char * val,const struct kernel_param * kp)3210 static int param_set_slot_table_size(const char *val,
3211 				     const struct kernel_param *kp)
3212 {
3213 	return param_set_uint_minmax(val, kp,
3214 			RPC_MIN_SLOT_TABLE,
3215 			RPC_MAX_SLOT_TABLE);
3216 }
3217 
3218 static const struct kernel_param_ops param_ops_slot_table_size = {
3219 	.set = param_set_slot_table_size,
3220 	.get = param_get_uint,
3221 };
3222 
3223 #define param_check_slot_table_size(name, p) \
3224 	__param_check(name, p, unsigned int);
3225 
param_set_max_slot_table_size(const char * val,const struct kernel_param * kp)3226 static int param_set_max_slot_table_size(const char *val,
3227 				     const struct kernel_param *kp)
3228 {
3229 	return param_set_uint_minmax(val, kp,
3230 			RPC_MIN_SLOT_TABLE,
3231 			RPC_MAX_SLOT_TABLE_LIMIT);
3232 }
3233 
3234 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3235 	.set = param_set_max_slot_table_size,
3236 	.get = param_get_uint,
3237 };
3238 
3239 #define param_check_max_slot_table_size(name, p) \
3240 	__param_check(name, p, unsigned int);
3241 
3242 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3243 		   slot_table_size, 0644);
3244 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3245 		   max_slot_table_size, 0644);
3246 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3247 		   slot_table_size, 0644);
3248