Merge tag 'trace-v5.15-rc6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rosted...
[platform/kernel/linux-rpi.git] / net / sunrpc / xprtsock.c
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
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
221 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
222 {
223         /* NOP */
224 }
225 #endif
226
227 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
228 {
229         return (struct rpc_xprt *) sk->sk_user_data;
230 }
231
232 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
233 {
234         return (struct sockaddr *) &xprt->addr;
235 }
236
237 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
238 {
239         return (struct sockaddr_un *) &xprt->addr;
240 }
241
242 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
243 {
244         return (struct sockaddr_in *) &xprt->addr;
245 }
246
247 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
248 {
249         return (struct sockaddr_in6 *) &xprt->addr;
250 }
251
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
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
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
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
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
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
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
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
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
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
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
402 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
403 {
404 }
405 #endif
406
407 static ssize_t
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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  *
767  */
768 static int xs_nospace(struct rpc_rqst *req)
769 {
770         struct rpc_xprt *xprt = req->rq_xprt;
771         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, 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                 /* wait for more buffer space */
783                 sk->sk_write_pending++;
784                 xprt_wait_for_buffer_space(xprt);
785         } else
786                 ret = -ENOTCONN;
787
788         spin_unlock(&xprt->transport_lock);
789
790         /* Race breaker in case memory is freed before above code is called */
791         if (ret == -EAGAIN) {
792                 struct socket_wq *wq;
793
794                 rcu_read_lock();
795                 wq = rcu_dereference(sk->sk_wq);
796                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
797                 rcu_read_unlock();
798
799                 sk->sk_write_space(sk);
800         }
801         return ret;
802 }
803
804 static void
805 xs_stream_prepare_request(struct rpc_rqst *req)
806 {
807         xdr_free_bvec(&req->rq_rcv_buf);
808         req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
809 }
810
811 /*
812  * Determine if the previous message in the stream was aborted before it
813  * could complete transmission.
814  */
815 static bool
816 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
817 {
818         return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
819 }
820
821 /*
822  * Return the stream record marker field for a record of length < 2^31-1
823  */
824 static rpc_fraghdr
825 xs_stream_record_marker(struct xdr_buf *xdr)
826 {
827         if (!xdr->len)
828                 return 0;
829         return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
830 }
831
832 /**
833  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
834  * @req: pointer to RPC request
835  *
836  * Return values:
837  *        0:    The request has been sent
838  *   EAGAIN:    The socket was blocked, please call again later to
839  *              complete the request
840  * ENOTCONN:    Caller needs to invoke connect logic then call again
841  *    other:    Some other error occurred, the request was not sent
842  */
843 static int xs_local_send_request(struct rpc_rqst *req)
844 {
845         struct rpc_xprt *xprt = req->rq_xprt;
846         struct sock_xprt *transport =
847                                 container_of(xprt, struct sock_xprt, xprt);
848         struct xdr_buf *xdr = &req->rq_snd_buf;
849         rpc_fraghdr rm = xs_stream_record_marker(xdr);
850         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
851         struct msghdr msg = {
852                 .msg_flags      = XS_SENDMSG_FLAGS,
853         };
854         unsigned int sent;
855         int status;
856
857         /* Close the stream if the previous transmission was incomplete */
858         if (xs_send_request_was_aborted(transport, req)) {
859                 xs_close(xprt);
860                 return -ENOTCONN;
861         }
862
863         xs_pktdump("packet data:",
864                         req->rq_svec->iov_base, req->rq_svec->iov_len);
865
866         req->rq_xtime = ktime_get();
867         status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
868                                    transport->xmit.offset, rm, &sent);
869         dprintk("RPC:       %s(%u) = %d\n",
870                         __func__, xdr->len - transport->xmit.offset, status);
871
872         if (status == -EAGAIN && sock_writeable(transport->inet))
873                 status = -ENOBUFS;
874
875         if (likely(sent > 0) || status == 0) {
876                 transport->xmit.offset += sent;
877                 req->rq_bytes_sent = transport->xmit.offset;
878                 if (likely(req->rq_bytes_sent >= msglen)) {
879                         req->rq_xmit_bytes_sent += transport->xmit.offset;
880                         transport->xmit.offset = 0;
881                         return 0;
882                 }
883                 status = -EAGAIN;
884         }
885
886         switch (status) {
887         case -ENOBUFS:
888                 break;
889         case -EAGAIN:
890                 status = xs_nospace(req);
891                 break;
892         default:
893                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
894                         -status);
895                 fallthrough;
896         case -EPIPE:
897                 xs_close(xprt);
898                 status = -ENOTCONN;
899         }
900
901         return status;
902 }
903
904 /**
905  * xs_udp_send_request - write an RPC request to a UDP socket
906  * @req: pointer to RPC request
907  *
908  * Return values:
909  *        0:    The request has been sent
910  *   EAGAIN:    The socket was blocked, please call again later to
911  *              complete the request
912  * ENOTCONN:    Caller needs to invoke connect logic then call again
913  *    other:    Some other error occurred, the request was not sent
914  */
915 static int xs_udp_send_request(struct rpc_rqst *req)
916 {
917         struct rpc_xprt *xprt = req->rq_xprt;
918         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
919         struct xdr_buf *xdr = &req->rq_snd_buf;
920         struct msghdr msg = {
921                 .msg_name       = xs_addr(xprt),
922                 .msg_namelen    = xprt->addrlen,
923                 .msg_flags      = XS_SENDMSG_FLAGS,
924         };
925         unsigned int sent;
926         int status;
927
928         xs_pktdump("packet data:",
929                                 req->rq_svec->iov_base,
930                                 req->rq_svec->iov_len);
931
932         if (!xprt_bound(xprt))
933                 return -ENOTCONN;
934
935         if (!xprt_request_get_cong(xprt, req))
936                 return -EBADSLT;
937
938         req->rq_xtime = ktime_get();
939         status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
940
941         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
942                         xdr->len, status);
943
944         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
945         if (status == -EPERM)
946                 goto process_status;
947
948         if (status == -EAGAIN && sock_writeable(transport->inet))
949                 status = -ENOBUFS;
950
951         if (sent > 0 || status == 0) {
952                 req->rq_xmit_bytes_sent += sent;
953                 if (sent >= req->rq_slen)
954                         return 0;
955                 /* Still some bytes left; set up for a retry later. */
956                 status = -EAGAIN;
957         }
958
959 process_status:
960         switch (status) {
961         case -ENOTSOCK:
962                 status = -ENOTCONN;
963                 /* Should we call xs_close() here? */
964                 break;
965         case -EAGAIN:
966                 status = xs_nospace(req);
967                 break;
968         case -ENETUNREACH:
969         case -ENOBUFS:
970         case -EPIPE:
971         case -ECONNREFUSED:
972         case -EPERM:
973                 /* When the server has died, an ICMP port unreachable message
974                  * prompts ECONNREFUSED. */
975                 break;
976         default:
977                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
978                         -status);
979         }
980
981         return status;
982 }
983
984 /**
985  * xs_tcp_send_request - write an RPC request to a TCP socket
986  * @req: pointer to RPC request
987  *
988  * Return values:
989  *        0:    The request has been sent
990  *   EAGAIN:    The socket was blocked, please call again later to
991  *              complete the request
992  * ENOTCONN:    Caller needs to invoke connect logic then call again
993  *    other:    Some other error occurred, the request was not sent
994  *
995  * XXX: In the case of soft timeouts, should we eventually give up
996  *      if sendmsg is not able to make progress?
997  */
998 static int xs_tcp_send_request(struct rpc_rqst *req)
999 {
1000         struct rpc_xprt *xprt = req->rq_xprt;
1001         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1002         struct xdr_buf *xdr = &req->rq_snd_buf;
1003         rpc_fraghdr rm = xs_stream_record_marker(xdr);
1004         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1005         struct msghdr msg = {
1006                 .msg_flags      = XS_SENDMSG_FLAGS,
1007         };
1008         bool vm_wait = false;
1009         unsigned int sent;
1010         int status;
1011
1012         /* Close the stream if the previous transmission was incomplete */
1013         if (xs_send_request_was_aborted(transport, req)) {
1014                 if (transport->sock != NULL)
1015                         kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1016                 return -ENOTCONN;
1017         }
1018         if (!transport->inet)
1019                 return -ENOTCONN;
1020
1021         xs_pktdump("packet data:",
1022                                 req->rq_svec->iov_base,
1023                                 req->rq_svec->iov_len);
1024
1025         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1026                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
1027
1028         /* Continue transmitting the packet/record. We must be careful
1029          * to cope with writespace callbacks arriving _after_ we have
1030          * called sendmsg(). */
1031         req->rq_xtime = ktime_get();
1032         tcp_sock_set_cork(transport->inet, true);
1033         while (1) {
1034                 status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1035                                            transport->xmit.offset, rm, &sent);
1036
1037                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1038                                 xdr->len - transport->xmit.offset, status);
1039
1040                 /* If we've sent the entire packet, immediately
1041                  * reset the count of bytes sent. */
1042                 transport->xmit.offset += sent;
1043                 req->rq_bytes_sent = transport->xmit.offset;
1044                 if (likely(req->rq_bytes_sent >= msglen)) {
1045                         req->rq_xmit_bytes_sent += transport->xmit.offset;
1046                         transport->xmit.offset = 0;
1047                         if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1048                                 tcp_sock_set_cork(transport->inet, false);
1049                         return 0;
1050                 }
1051
1052                 WARN_ON_ONCE(sent == 0 && status == 0);
1053
1054                 if (status == -EAGAIN ) {
1055                         /*
1056                          * Return EAGAIN if we're sure we're hitting the
1057                          * socket send buffer limits.
1058                          */
1059                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1060                                 break;
1061                         /*
1062                          * Did we hit a memory allocation failure?
1063                          */
1064                         if (sent == 0) {
1065                                 status = -ENOBUFS;
1066                                 if (vm_wait)
1067                                         break;
1068                                 /* Retry, knowing now that we're below the
1069                                  * socket send buffer limit
1070                                  */
1071                                 vm_wait = true;
1072                         }
1073                         continue;
1074                 }
1075                 if (status < 0)
1076                         break;
1077                 vm_wait = false;
1078         }
1079
1080         switch (status) {
1081         case -ENOTSOCK:
1082                 status = -ENOTCONN;
1083                 /* Should we call xs_close() here? */
1084                 break;
1085         case -EAGAIN:
1086                 status = xs_nospace(req);
1087                 break;
1088         case -ECONNRESET:
1089         case -ECONNREFUSED:
1090         case -ENOTCONN:
1091         case -EADDRINUSE:
1092         case -ENOBUFS:
1093         case -EPIPE:
1094                 break;
1095         default:
1096                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1097                         -status);
1098         }
1099
1100         return status;
1101 }
1102
1103 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1104 {
1105         transport->old_data_ready = sk->sk_data_ready;
1106         transport->old_state_change = sk->sk_state_change;
1107         transport->old_write_space = sk->sk_write_space;
1108         transport->old_error_report = sk->sk_error_report;
1109 }
1110
1111 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1112 {
1113         sk->sk_data_ready = transport->old_data_ready;
1114         sk->sk_state_change = transport->old_state_change;
1115         sk->sk_write_space = transport->old_write_space;
1116         sk->sk_error_report = transport->old_error_report;
1117 }
1118
1119 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1120 {
1121         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1122
1123         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1124         clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1125         clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1126         clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1127 }
1128
1129 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1130 {
1131         set_bit(nr, &transport->sock_state);
1132         queue_work(xprtiod_workqueue, &transport->error_worker);
1133 }
1134
1135 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1136 {
1137         smp_mb__before_atomic();
1138         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1139         clear_bit(XPRT_CLOSING, &xprt->state);
1140         xs_sock_reset_state_flags(xprt);
1141         smp_mb__after_atomic();
1142 }
1143
1144 /**
1145  * xs_error_report - callback to handle TCP socket state errors
1146  * @sk: socket
1147  *
1148  * Note: we don't call sock_error() since there may be a rpc_task
1149  * using the socket, and so we don't want to clear sk->sk_err.
1150  */
1151 static void xs_error_report(struct sock *sk)
1152 {
1153         struct sock_xprt *transport;
1154         struct rpc_xprt *xprt;
1155
1156         read_lock_bh(&sk->sk_callback_lock);
1157         if (!(xprt = xprt_from_sock(sk)))
1158                 goto out;
1159
1160         transport = container_of(xprt, struct sock_xprt, xprt);
1161         transport->xprt_err = -sk->sk_err;
1162         if (transport->xprt_err == 0)
1163                 goto out;
1164         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1165                         xprt, -transport->xprt_err);
1166         trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1167
1168         /* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1169         smp_mb__before_atomic();
1170         xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1171  out:
1172         read_unlock_bh(&sk->sk_callback_lock);
1173 }
1174
1175 static void xs_reset_transport(struct sock_xprt *transport)
1176 {
1177         struct socket *sock = transport->sock;
1178         struct sock *sk = transport->inet;
1179         struct rpc_xprt *xprt = &transport->xprt;
1180         struct file *filp = transport->file;
1181
1182         if (sk == NULL)
1183                 return;
1184
1185         if (atomic_read(&transport->xprt.swapper))
1186                 sk_clear_memalloc(sk);
1187
1188         kernel_sock_shutdown(sock, SHUT_RDWR);
1189
1190         mutex_lock(&transport->recv_mutex);
1191         write_lock_bh(&sk->sk_callback_lock);
1192         transport->inet = NULL;
1193         transport->sock = NULL;
1194         transport->file = NULL;
1195
1196         sk->sk_user_data = NULL;
1197
1198         xs_restore_old_callbacks(transport, sk);
1199         xprt_clear_connected(xprt);
1200         write_unlock_bh(&sk->sk_callback_lock);
1201         xs_sock_reset_connection_flags(xprt);
1202         /* Reset stream record info */
1203         xs_stream_reset_connect(transport);
1204         mutex_unlock(&transport->recv_mutex);
1205
1206         trace_rpc_socket_close(xprt, sock);
1207         fput(filp);
1208
1209         xprt_disconnect_done(xprt);
1210 }
1211
1212 /**
1213  * xs_close - close a socket
1214  * @xprt: transport
1215  *
1216  * This is used when all requests are complete; ie, no DRC state remains
1217  * on the server we want to save.
1218  *
1219  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1220  * xs_reset_transport() zeroing the socket from underneath a writer.
1221  */
1222 static void xs_close(struct rpc_xprt *xprt)
1223 {
1224         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1225
1226         dprintk("RPC:       xs_close xprt %p\n", xprt);
1227
1228         xs_reset_transport(transport);
1229         xprt->reestablish_timeout = 0;
1230 }
1231
1232 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1233 {
1234         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1235                 xprt);
1236         xprt_disconnect_done(xprt);
1237 }
1238
1239 static void xs_xprt_free(struct rpc_xprt *xprt)
1240 {
1241         xs_free_peer_addresses(xprt);
1242         xprt_free(xprt);
1243 }
1244
1245 /**
1246  * xs_destroy - prepare to shutdown a transport
1247  * @xprt: doomed transport
1248  *
1249  */
1250 static void xs_destroy(struct rpc_xprt *xprt)
1251 {
1252         struct sock_xprt *transport = container_of(xprt,
1253                         struct sock_xprt, xprt);
1254         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1255
1256         cancel_delayed_work_sync(&transport->connect_worker);
1257         xs_close(xprt);
1258         cancel_work_sync(&transport->recv_worker);
1259         cancel_work_sync(&transport->error_worker);
1260         xs_xprt_free(xprt);
1261         module_put(THIS_MODULE);
1262 }
1263
1264 /**
1265  * xs_udp_data_read_skb - receive callback for UDP sockets
1266  * @xprt: transport
1267  * @sk: socket
1268  * @skb: skbuff
1269  *
1270  */
1271 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1272                 struct sock *sk,
1273                 struct sk_buff *skb)
1274 {
1275         struct rpc_task *task;
1276         struct rpc_rqst *rovr;
1277         int repsize, copied;
1278         u32 _xid;
1279         __be32 *xp;
1280
1281         repsize = skb->len;
1282         if (repsize < 4) {
1283                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1284                 return;
1285         }
1286
1287         /* Copy the XID from the skb... */
1288         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1289         if (xp == NULL)
1290                 return;
1291
1292         /* Look up and lock the request corresponding to the given XID */
1293         spin_lock(&xprt->queue_lock);
1294         rovr = xprt_lookup_rqst(xprt, *xp);
1295         if (!rovr)
1296                 goto out_unlock;
1297         xprt_pin_rqst(rovr);
1298         xprt_update_rtt(rovr->rq_task);
1299         spin_unlock(&xprt->queue_lock);
1300         task = rovr->rq_task;
1301
1302         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1303                 copied = repsize;
1304
1305         /* Suck it into the iovec, verify checksum if not done by hw. */
1306         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1307                 spin_lock(&xprt->queue_lock);
1308                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1309                 goto out_unpin;
1310         }
1311
1312
1313         spin_lock(&xprt->transport_lock);
1314         xprt_adjust_cwnd(xprt, task, copied);
1315         spin_unlock(&xprt->transport_lock);
1316         spin_lock(&xprt->queue_lock);
1317         xprt_complete_rqst(task, copied);
1318         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1319 out_unpin:
1320         xprt_unpin_rqst(rovr);
1321  out_unlock:
1322         spin_unlock(&xprt->queue_lock);
1323 }
1324
1325 static void xs_udp_data_receive(struct sock_xprt *transport)
1326 {
1327         struct sk_buff *skb;
1328         struct sock *sk;
1329         int err;
1330
1331         mutex_lock(&transport->recv_mutex);
1332         sk = transport->inet;
1333         if (sk == NULL)
1334                 goto out;
1335         for (;;) {
1336                 skb = skb_recv_udp(sk, 0, 1, &err);
1337                 if (skb == NULL)
1338                         break;
1339                 xs_udp_data_read_skb(&transport->xprt, sk, skb);
1340                 consume_skb(skb);
1341                 cond_resched();
1342         }
1343         xs_poll_check_readable(transport);
1344 out:
1345         mutex_unlock(&transport->recv_mutex);
1346 }
1347
1348 static void xs_udp_data_receive_workfn(struct work_struct *work)
1349 {
1350         struct sock_xprt *transport =
1351                 container_of(work, struct sock_xprt, recv_worker);
1352         unsigned int pflags = memalloc_nofs_save();
1353
1354         xs_udp_data_receive(transport);
1355         memalloc_nofs_restore(pflags);
1356 }
1357
1358 /**
1359  * xs_data_ready - "data ready" callback for UDP sockets
1360  * @sk: socket with data to read
1361  *
1362  */
1363 static void xs_data_ready(struct sock *sk)
1364 {
1365         struct rpc_xprt *xprt;
1366
1367         read_lock_bh(&sk->sk_callback_lock);
1368         dprintk("RPC:       xs_data_ready...\n");
1369         xprt = xprt_from_sock(sk);
1370         if (xprt != NULL) {
1371                 struct sock_xprt *transport = container_of(xprt,
1372                                 struct sock_xprt, xprt);
1373                 transport->old_data_ready(sk);
1374                 /* Any data means we had a useful conversation, so
1375                  * then we don't need to delay the next reconnect
1376                  */
1377                 if (xprt->reestablish_timeout)
1378                         xprt->reestablish_timeout = 0;
1379                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1380                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1381         }
1382         read_unlock_bh(&sk->sk_callback_lock);
1383 }
1384
1385 /*
1386  * Helper function to force a TCP close if the server is sending
1387  * junk and/or it has put us in CLOSE_WAIT
1388  */
1389 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1390 {
1391         xprt_force_disconnect(xprt);
1392 }
1393
1394 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1395 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1396 {
1397         return PAGE_SIZE;
1398 }
1399 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1400
1401 /**
1402  * xs_tcp_state_change - callback to handle TCP socket state changes
1403  * @sk: socket whose state has changed
1404  *
1405  */
1406 static void xs_tcp_state_change(struct sock *sk)
1407 {
1408         struct rpc_xprt *xprt;
1409         struct sock_xprt *transport;
1410
1411         read_lock_bh(&sk->sk_callback_lock);
1412         if (!(xprt = xprt_from_sock(sk)))
1413                 goto out;
1414         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1415         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1416                         sk->sk_state, xprt_connected(xprt),
1417                         sock_flag(sk, SOCK_DEAD),
1418                         sock_flag(sk, SOCK_ZAPPED),
1419                         sk->sk_shutdown);
1420
1421         transport = container_of(xprt, struct sock_xprt, xprt);
1422         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1423         switch (sk->sk_state) {
1424         case TCP_ESTABLISHED:
1425                 if (!xprt_test_and_set_connected(xprt)) {
1426                         xprt->connect_cookie++;
1427                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1428                         xprt_clear_connecting(xprt);
1429
1430                         xprt->stat.connect_count++;
1431                         xprt->stat.connect_time += (long)jiffies -
1432                                                    xprt->stat.connect_start;
1433                         xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1434                 }
1435                 break;
1436         case TCP_FIN_WAIT1:
1437                 /* The client initiated a shutdown of the socket */
1438                 xprt->connect_cookie++;
1439                 xprt->reestablish_timeout = 0;
1440                 set_bit(XPRT_CLOSING, &xprt->state);
1441                 smp_mb__before_atomic();
1442                 clear_bit(XPRT_CONNECTED, &xprt->state);
1443                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1444                 smp_mb__after_atomic();
1445                 break;
1446         case TCP_CLOSE_WAIT:
1447                 /* The server initiated a shutdown of the socket */
1448                 xprt->connect_cookie++;
1449                 clear_bit(XPRT_CONNECTED, &xprt->state);
1450                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1451                 fallthrough;
1452         case TCP_CLOSING:
1453                 /*
1454                  * If the server closed down the connection, make sure that
1455                  * we back off before reconnecting
1456                  */
1457                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1458                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1459                 break;
1460         case TCP_LAST_ACK:
1461                 set_bit(XPRT_CLOSING, &xprt->state);
1462                 smp_mb__before_atomic();
1463                 clear_bit(XPRT_CONNECTED, &xprt->state);
1464                 smp_mb__after_atomic();
1465                 break;
1466         case TCP_CLOSE:
1467                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1468                                         &transport->sock_state))
1469                         xprt_clear_connecting(xprt);
1470                 clear_bit(XPRT_CLOSING, &xprt->state);
1471                 /* Trigger the socket release */
1472                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1473         }
1474  out:
1475         read_unlock_bh(&sk->sk_callback_lock);
1476 }
1477
1478 static void xs_write_space(struct sock *sk)
1479 {
1480         struct socket_wq *wq;
1481         struct sock_xprt *transport;
1482         struct rpc_xprt *xprt;
1483
1484         if (!sk->sk_socket)
1485                 return;
1486         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1487
1488         if (unlikely(!(xprt = xprt_from_sock(sk))))
1489                 return;
1490         transport = container_of(xprt, struct sock_xprt, xprt);
1491         rcu_read_lock();
1492         wq = rcu_dereference(sk->sk_wq);
1493         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1494                 goto out;
1495
1496         xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1497         sk->sk_write_pending--;
1498 out:
1499         rcu_read_unlock();
1500 }
1501
1502 /**
1503  * xs_udp_write_space - callback invoked when socket buffer space
1504  *                             becomes available
1505  * @sk: socket whose state has changed
1506  *
1507  * Called when more output buffer space is available for this socket.
1508  * We try not to wake our writers until they can make "significant"
1509  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1510  * with a bunch of small requests.
1511  */
1512 static void xs_udp_write_space(struct sock *sk)
1513 {
1514         read_lock_bh(&sk->sk_callback_lock);
1515
1516         /* from net/core/sock.c:sock_def_write_space */
1517         if (sock_writeable(sk))
1518                 xs_write_space(sk);
1519
1520         read_unlock_bh(&sk->sk_callback_lock);
1521 }
1522
1523 /**
1524  * xs_tcp_write_space - callback invoked when socket buffer space
1525  *                             becomes available
1526  * @sk: socket whose state has changed
1527  *
1528  * Called when more output buffer space is available for this socket.
1529  * We try not to wake our writers until they can make "significant"
1530  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1531  * with a bunch of small requests.
1532  */
1533 static void xs_tcp_write_space(struct sock *sk)
1534 {
1535         read_lock_bh(&sk->sk_callback_lock);
1536
1537         /* from net/core/stream.c:sk_stream_write_space */
1538         if (sk_stream_is_writeable(sk))
1539                 xs_write_space(sk);
1540
1541         read_unlock_bh(&sk->sk_callback_lock);
1542 }
1543
1544 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1545 {
1546         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1547         struct sock *sk = transport->inet;
1548
1549         if (transport->rcvsize) {
1550                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1551                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1552         }
1553         if (transport->sndsize) {
1554                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1555                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1556                 sk->sk_write_space(sk);
1557         }
1558 }
1559
1560 /**
1561  * xs_udp_set_buffer_size - set send and receive limits
1562  * @xprt: generic transport
1563  * @sndsize: requested size of send buffer, in bytes
1564  * @rcvsize: requested size of receive buffer, in bytes
1565  *
1566  * Set socket send and receive buffer size limits.
1567  */
1568 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1569 {
1570         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1571
1572         transport->sndsize = 0;
1573         if (sndsize)
1574                 transport->sndsize = sndsize + 1024;
1575         transport->rcvsize = 0;
1576         if (rcvsize)
1577                 transport->rcvsize = rcvsize + 1024;
1578
1579         xs_udp_do_set_buffer_size(xprt);
1580 }
1581
1582 /**
1583  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1584  * @xprt: controlling transport
1585  * @task: task that timed out
1586  *
1587  * Adjust the congestion window after a retransmit timeout has occurred.
1588  */
1589 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1590 {
1591         spin_lock(&xprt->transport_lock);
1592         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1593         spin_unlock(&xprt->transport_lock);
1594 }
1595
1596 static int xs_get_random_port(void)
1597 {
1598         unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1599         unsigned short range;
1600         unsigned short rand;
1601
1602         if (max < min)
1603                 return -EADDRINUSE;
1604         range = max - min + 1;
1605         rand = (unsigned short) prandom_u32() % range;
1606         return rand + min;
1607 }
1608
1609 static unsigned short xs_sock_getport(struct socket *sock)
1610 {
1611         struct sockaddr_storage buf;
1612         unsigned short port = 0;
1613
1614         if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1615                 goto out;
1616         switch (buf.ss_family) {
1617         case AF_INET6:
1618                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1619                 break;
1620         case AF_INET:
1621                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1622         }
1623 out:
1624         return port;
1625 }
1626
1627 /**
1628  * xs_set_port - reset the port number in the remote endpoint address
1629  * @xprt: generic transport
1630  * @port: new port number
1631  *
1632  */
1633 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1634 {
1635         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1636
1637         rpc_set_port(xs_addr(xprt), port);
1638         xs_update_peer_port(xprt);
1639 }
1640
1641 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1642 {
1643         if (transport->srcport == 0 && transport->xprt.reuseport)
1644                 transport->srcport = xs_sock_getport(sock);
1645 }
1646
1647 static int xs_get_srcport(struct sock_xprt *transport)
1648 {
1649         int port = transport->srcport;
1650
1651         if (port == 0 && transport->xprt.resvport)
1652                 port = xs_get_random_port();
1653         return port;
1654 }
1655
1656 unsigned short get_srcport(struct rpc_xprt *xprt)
1657 {
1658         struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
1659         return xs_sock_getport(sock->sock);
1660 }
1661 EXPORT_SYMBOL(get_srcport);
1662
1663 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1664 {
1665         if (transport->srcport != 0)
1666                 transport->srcport = 0;
1667         if (!transport->xprt.resvport)
1668                 return 0;
1669         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1670                 return xprt_max_resvport;
1671         return --port;
1672 }
1673 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1674 {
1675         struct sockaddr_storage myaddr;
1676         int err, nloop = 0;
1677         int port = xs_get_srcport(transport);
1678         unsigned short last;
1679
1680         /*
1681          * If we are asking for any ephemeral port (i.e. port == 0 &&
1682          * transport->xprt.resvport == 0), don't bind.  Let the local
1683          * port selection happen implicitly when the socket is used
1684          * (for example at connect time).
1685          *
1686          * This ensures that we can continue to establish TCP
1687          * connections even when all local ephemeral ports are already
1688          * a part of some TCP connection.  This makes no difference
1689          * for UDP sockets, but also doesn't harm them.
1690          *
1691          * If we're asking for any reserved port (i.e. port == 0 &&
1692          * transport->xprt.resvport == 1) xs_get_srcport above will
1693          * ensure that port is non-zero and we will bind as needed.
1694          */
1695         if (port <= 0)
1696                 return port;
1697
1698         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1699         do {
1700                 rpc_set_port((struct sockaddr *)&myaddr, port);
1701                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1702                                 transport->xprt.addrlen);
1703                 if (err == 0) {
1704                         if (transport->xprt.reuseport)
1705                                 transport->srcport = port;
1706                         break;
1707                 }
1708                 last = port;
1709                 port = xs_next_srcport(transport, port);
1710                 if (port > last)
1711                         nloop++;
1712         } while (err == -EADDRINUSE && nloop != 2);
1713
1714         if (myaddr.ss_family == AF_INET)
1715                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1716                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1717                                 port, err ? "failed" : "ok", err);
1718         else
1719                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1720                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1721                                 port, err ? "failed" : "ok", err);
1722         return err;
1723 }
1724
1725 /*
1726  * We don't support autobind on AF_LOCAL sockets
1727  */
1728 static void xs_local_rpcbind(struct rpc_task *task)
1729 {
1730         xprt_set_bound(task->tk_xprt);
1731 }
1732
1733 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1734 {
1735 }
1736
1737 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1738 static struct lock_class_key xs_key[2];
1739 static struct lock_class_key xs_slock_key[2];
1740
1741 static inline void xs_reclassify_socketu(struct socket *sock)
1742 {
1743         struct sock *sk = sock->sk;
1744
1745         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1746                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1747 }
1748
1749 static inline void xs_reclassify_socket4(struct socket *sock)
1750 {
1751         struct sock *sk = sock->sk;
1752
1753         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1754                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1755 }
1756
1757 static inline void xs_reclassify_socket6(struct socket *sock)
1758 {
1759         struct sock *sk = sock->sk;
1760
1761         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1762                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1763 }
1764
1765 static inline void xs_reclassify_socket(int family, struct socket *sock)
1766 {
1767         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1768                 return;
1769
1770         switch (family) {
1771         case AF_LOCAL:
1772                 xs_reclassify_socketu(sock);
1773                 break;
1774         case AF_INET:
1775                 xs_reclassify_socket4(sock);
1776                 break;
1777         case AF_INET6:
1778                 xs_reclassify_socket6(sock);
1779                 break;
1780         }
1781 }
1782 #else
1783 static inline void xs_reclassify_socket(int family, struct socket *sock)
1784 {
1785 }
1786 #endif
1787
1788 static void xs_dummy_setup_socket(struct work_struct *work)
1789 {
1790 }
1791
1792 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1793                 struct sock_xprt *transport, int family, int type,
1794                 int protocol, bool reuseport)
1795 {
1796         struct file *filp;
1797         struct socket *sock;
1798         int err;
1799
1800         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1801         if (err < 0) {
1802                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1803                                 protocol, -err);
1804                 goto out;
1805         }
1806         xs_reclassify_socket(family, sock);
1807
1808         if (reuseport)
1809                 sock_set_reuseport(sock->sk);
1810
1811         err = xs_bind(transport, sock);
1812         if (err) {
1813                 sock_release(sock);
1814                 goto out;
1815         }
1816
1817         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1818         if (IS_ERR(filp))
1819                 return ERR_CAST(filp);
1820         transport->file = filp;
1821
1822         return sock;
1823 out:
1824         return ERR_PTR(err);
1825 }
1826
1827 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1828                                       struct socket *sock)
1829 {
1830         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1831                                                                         xprt);
1832
1833         if (!transport->inet) {
1834                 struct sock *sk = sock->sk;
1835
1836                 write_lock_bh(&sk->sk_callback_lock);
1837
1838                 xs_save_old_callbacks(transport, sk);
1839
1840                 sk->sk_user_data = xprt;
1841                 sk->sk_data_ready = xs_data_ready;
1842                 sk->sk_write_space = xs_udp_write_space;
1843                 sock_set_flag(sk, SOCK_FASYNC);
1844                 sk->sk_error_report = xs_error_report;
1845
1846                 xprt_clear_connected(xprt);
1847
1848                 /* Reset to new socket */
1849                 transport->sock = sock;
1850                 transport->inet = sk;
1851
1852                 write_unlock_bh(&sk->sk_callback_lock);
1853         }
1854
1855         xs_stream_start_connect(transport);
1856
1857         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1858 }
1859
1860 /**
1861  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1862  * @transport: socket transport to connect
1863  */
1864 static int xs_local_setup_socket(struct sock_xprt *transport)
1865 {
1866         struct rpc_xprt *xprt = &transport->xprt;
1867         struct file *filp;
1868         struct socket *sock;
1869         int status;
1870
1871         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1872                                         SOCK_STREAM, 0, &sock, 1);
1873         if (status < 0) {
1874                 dprintk("RPC:       can't create AF_LOCAL "
1875                         "transport socket (%d).\n", -status);
1876                 goto out;
1877         }
1878         xs_reclassify_socket(AF_LOCAL, sock);
1879
1880         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1881         if (IS_ERR(filp)) {
1882                 status = PTR_ERR(filp);
1883                 goto out;
1884         }
1885         transport->file = filp;
1886
1887         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1888                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1889
1890         status = xs_local_finish_connecting(xprt, sock);
1891         trace_rpc_socket_connect(xprt, sock, status);
1892         switch (status) {
1893         case 0:
1894                 dprintk("RPC:       xprt %p connected to %s\n",
1895                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1896                 xprt->stat.connect_count++;
1897                 xprt->stat.connect_time += (long)jiffies -
1898                                            xprt->stat.connect_start;
1899                 xprt_set_connected(xprt);
1900                 break;
1901         case -ENOBUFS:
1902                 break;
1903         case -ENOENT:
1904                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1905                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1906                 break;
1907         case -ECONNREFUSED:
1908                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1909                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1910                 break;
1911         default:
1912                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1913                                 __func__, -status,
1914                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1915         }
1916
1917 out:
1918         xprt_clear_connecting(xprt);
1919         xprt_wake_pending_tasks(xprt, status);
1920         return status;
1921 }
1922
1923 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1924 {
1925         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1926         int ret;
1927
1928          if (RPC_IS_ASYNC(task)) {
1929                 /*
1930                  * We want the AF_LOCAL connect to be resolved in the
1931                  * filesystem namespace of the process making the rpc
1932                  * call.  Thus we connect synchronously.
1933                  *
1934                  * If we want to support asynchronous AF_LOCAL calls,
1935                  * we'll need to figure out how to pass a namespace to
1936                  * connect.
1937                  */
1938                 task->tk_rpc_status = -ENOTCONN;
1939                 rpc_exit(task, -ENOTCONN);
1940                 return;
1941         }
1942         ret = xs_local_setup_socket(transport);
1943         if (ret && !RPC_IS_SOFTCONN(task))
1944                 msleep_interruptible(15000);
1945 }
1946
1947 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1948 /*
1949  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1950  * know that we have exclusive access to the socket), to guard against
1951  * races with xs_reset_transport.
1952  */
1953 static void xs_set_memalloc(struct rpc_xprt *xprt)
1954 {
1955         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1956                         xprt);
1957
1958         /*
1959          * If there's no sock, then we have nothing to set. The
1960          * reconnecting process will get it for us.
1961          */
1962         if (!transport->inet)
1963                 return;
1964         if (atomic_read(&xprt->swapper))
1965                 sk_set_memalloc(transport->inet);
1966 }
1967
1968 /**
1969  * xs_enable_swap - Tag this transport as being used for swap.
1970  * @xprt: transport to tag
1971  *
1972  * Take a reference to this transport on behalf of the rpc_clnt, and
1973  * optionally mark it for swapping if it wasn't already.
1974  */
1975 static int
1976 xs_enable_swap(struct rpc_xprt *xprt)
1977 {
1978         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1979
1980         if (atomic_inc_return(&xprt->swapper) != 1)
1981                 return 0;
1982         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1983                 return -ERESTARTSYS;
1984         if (xs->inet)
1985                 sk_set_memalloc(xs->inet);
1986         xprt_release_xprt(xprt, NULL);
1987         return 0;
1988 }
1989
1990 /**
1991  * xs_disable_swap - Untag this transport as being used for swap.
1992  * @xprt: transport to tag
1993  *
1994  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1995  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1996  */
1997 static void
1998 xs_disable_swap(struct rpc_xprt *xprt)
1999 {
2000         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2001
2002         if (!atomic_dec_and_test(&xprt->swapper))
2003                 return;
2004         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2005                 return;
2006         if (xs->inet)
2007                 sk_clear_memalloc(xs->inet);
2008         xprt_release_xprt(xprt, NULL);
2009 }
2010 #else
2011 static void xs_set_memalloc(struct rpc_xprt *xprt)
2012 {
2013 }
2014
2015 static int
2016 xs_enable_swap(struct rpc_xprt *xprt)
2017 {
2018         return -EINVAL;
2019 }
2020
2021 static void
2022 xs_disable_swap(struct rpc_xprt *xprt)
2023 {
2024 }
2025 #endif
2026
2027 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2028 {
2029         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2030
2031         if (!transport->inet) {
2032                 struct sock *sk = sock->sk;
2033
2034                 write_lock_bh(&sk->sk_callback_lock);
2035
2036                 xs_save_old_callbacks(transport, sk);
2037
2038                 sk->sk_user_data = xprt;
2039                 sk->sk_data_ready = xs_data_ready;
2040                 sk->sk_write_space = xs_udp_write_space;
2041                 sock_set_flag(sk, SOCK_FASYNC);
2042
2043                 xprt_set_connected(xprt);
2044
2045                 /* Reset to new socket */
2046                 transport->sock = sock;
2047                 transport->inet = sk;
2048
2049                 xs_set_memalloc(xprt);
2050
2051                 write_unlock_bh(&sk->sk_callback_lock);
2052         }
2053         xs_udp_do_set_buffer_size(xprt);
2054
2055         xprt->stat.connect_start = jiffies;
2056 }
2057
2058 static void xs_udp_setup_socket(struct work_struct *work)
2059 {
2060         struct sock_xprt *transport =
2061                 container_of(work, struct sock_xprt, connect_worker.work);
2062         struct rpc_xprt *xprt = &transport->xprt;
2063         struct socket *sock;
2064         int status = -EIO;
2065
2066         sock = xs_create_sock(xprt, transport,
2067                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2068                         IPPROTO_UDP, false);
2069         if (IS_ERR(sock))
2070                 goto out;
2071
2072         dprintk("RPC:       worker connecting xprt %p via %s to "
2073                                 "%s (port %s)\n", xprt,
2074                         xprt->address_strings[RPC_DISPLAY_PROTO],
2075                         xprt->address_strings[RPC_DISPLAY_ADDR],
2076                         xprt->address_strings[RPC_DISPLAY_PORT]);
2077
2078         xs_udp_finish_connecting(xprt, sock);
2079         trace_rpc_socket_connect(xprt, sock, 0);
2080         status = 0;
2081 out:
2082         xprt_clear_connecting(xprt);
2083         xprt_unlock_connect(xprt, transport);
2084         xprt_wake_pending_tasks(xprt, status);
2085 }
2086
2087 /**
2088  * xs_tcp_shutdown - gracefully shut down a TCP socket
2089  * @xprt: transport
2090  *
2091  * Initiates a graceful shutdown of the TCP socket by calling the
2092  * equivalent of shutdown(SHUT_RDWR);
2093  */
2094 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2095 {
2096         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2097         struct socket *sock = transport->sock;
2098         int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2099
2100         if (sock == NULL)
2101                 return;
2102         if (!xprt->reuseport) {
2103                 xs_close(xprt);
2104                 return;
2105         }
2106         switch (skst) {
2107         case TCP_FIN_WAIT1:
2108         case TCP_FIN_WAIT2:
2109                 break;
2110         case TCP_ESTABLISHED:
2111         case TCP_CLOSE_WAIT:
2112                 kernel_sock_shutdown(sock, SHUT_RDWR);
2113                 trace_rpc_socket_shutdown(xprt, sock);
2114                 break;
2115         default:
2116                 xs_reset_transport(transport);
2117         }
2118 }
2119
2120 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2121                 struct socket *sock)
2122 {
2123         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2124         unsigned int keepidle;
2125         unsigned int keepcnt;
2126         unsigned int timeo;
2127
2128         spin_lock(&xprt->transport_lock);
2129         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2130         keepcnt = xprt->timeout->to_retries + 1;
2131         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2132                 (xprt->timeout->to_retries + 1);
2133         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2134         spin_unlock(&xprt->transport_lock);
2135
2136         /* TCP Keepalive options */
2137         sock_set_keepalive(sock->sk);
2138         tcp_sock_set_keepidle(sock->sk, keepidle);
2139         tcp_sock_set_keepintvl(sock->sk, keepidle);
2140         tcp_sock_set_keepcnt(sock->sk, keepcnt);
2141
2142         /* TCP user timeout (see RFC5482) */
2143         tcp_sock_set_user_timeout(sock->sk, timeo);
2144 }
2145
2146 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2147                 unsigned long connect_timeout,
2148                 unsigned long reconnect_timeout)
2149 {
2150         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2151         struct rpc_timeout to;
2152         unsigned long initval;
2153
2154         spin_lock(&xprt->transport_lock);
2155         if (reconnect_timeout < xprt->max_reconnect_timeout)
2156                 xprt->max_reconnect_timeout = reconnect_timeout;
2157         if (connect_timeout < xprt->connect_timeout) {
2158                 memcpy(&to, xprt->timeout, sizeof(to));
2159                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2160                 /* Arbitrary lower limit */
2161                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2162                         initval = XS_TCP_INIT_REEST_TO << 1;
2163                 to.to_initval = initval;
2164                 to.to_maxval = initval;
2165                 memcpy(&transport->tcp_timeout, &to,
2166                                 sizeof(transport->tcp_timeout));
2167                 xprt->timeout = &transport->tcp_timeout;
2168                 xprt->connect_timeout = connect_timeout;
2169         }
2170         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2171         spin_unlock(&xprt->transport_lock);
2172 }
2173
2174 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2175 {
2176         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2177         int ret = -ENOTCONN;
2178
2179         if (!transport->inet) {
2180                 struct sock *sk = sock->sk;
2181
2182                 /* Avoid temporary address, they are bad for long-lived
2183                  * connections such as NFS mounts.
2184                  * RFC4941, section 3.6 suggests that:
2185                  *    Individual applications, which have specific
2186                  *    knowledge about the normal duration of connections,
2187                  *    MAY override this as appropriate.
2188                  */
2189                 if (xs_addr(xprt)->sa_family == PF_INET6) {
2190                         ip6_sock_set_addr_preferences(sk,
2191                                 IPV6_PREFER_SRC_PUBLIC);
2192                 }
2193
2194                 xs_tcp_set_socket_timeouts(xprt, sock);
2195                 tcp_sock_set_nodelay(sk);
2196
2197                 write_lock_bh(&sk->sk_callback_lock);
2198
2199                 xs_save_old_callbacks(transport, sk);
2200
2201                 sk->sk_user_data = xprt;
2202                 sk->sk_data_ready = xs_data_ready;
2203                 sk->sk_state_change = xs_tcp_state_change;
2204                 sk->sk_write_space = xs_tcp_write_space;
2205                 sock_set_flag(sk, SOCK_FASYNC);
2206                 sk->sk_error_report = xs_error_report;
2207
2208                 /* socket options */
2209                 sock_reset_flag(sk, SOCK_LINGER);
2210
2211                 xprt_clear_connected(xprt);
2212
2213                 /* Reset to new socket */
2214                 transport->sock = sock;
2215                 transport->inet = sk;
2216
2217                 write_unlock_bh(&sk->sk_callback_lock);
2218         }
2219
2220         if (!xprt_bound(xprt))
2221                 goto out;
2222
2223         xs_set_memalloc(xprt);
2224
2225         xs_stream_start_connect(transport);
2226
2227         /* Tell the socket layer to start connecting... */
2228         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2229         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2230         switch (ret) {
2231         case 0:
2232                 xs_set_srcport(transport, sock);
2233                 fallthrough;
2234         case -EINPROGRESS:
2235                 /* SYN_SENT! */
2236                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2237                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2238                 break;
2239         case -EADDRNOTAVAIL:
2240                 /* Source port number is unavailable. Try a new one! */
2241                 transport->srcport = 0;
2242         }
2243 out:
2244         return ret;
2245 }
2246
2247 /**
2248  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2249  * @work: queued work item
2250  *
2251  * Invoked by a work queue tasklet.
2252  */
2253 static void xs_tcp_setup_socket(struct work_struct *work)
2254 {
2255         struct sock_xprt *transport =
2256                 container_of(work, struct sock_xprt, connect_worker.work);
2257         struct socket *sock = transport->sock;
2258         struct rpc_xprt *xprt = &transport->xprt;
2259         int status = -EIO;
2260
2261         if (!sock) {
2262                 sock = xs_create_sock(xprt, transport,
2263                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2264                                 IPPROTO_TCP, true);
2265                 if (IS_ERR(sock)) {
2266                         status = PTR_ERR(sock);
2267                         goto out;
2268                 }
2269         }
2270
2271         dprintk("RPC:       worker connecting xprt %p via %s to "
2272                                 "%s (port %s)\n", xprt,
2273                         xprt->address_strings[RPC_DISPLAY_PROTO],
2274                         xprt->address_strings[RPC_DISPLAY_ADDR],
2275                         xprt->address_strings[RPC_DISPLAY_PORT]);
2276
2277         status = xs_tcp_finish_connecting(xprt, sock);
2278         trace_rpc_socket_connect(xprt, sock, status);
2279         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2280                         xprt, -status, xprt_connected(xprt),
2281                         sock->sk->sk_state);
2282         switch (status) {
2283         default:
2284                 printk("%s: connect returned unhandled error %d\n",
2285                         __func__, status);
2286                 fallthrough;
2287         case -EADDRNOTAVAIL:
2288                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2289                  * and retry
2290                  */
2291                 xs_tcp_force_close(xprt);
2292                 break;
2293         case 0:
2294         case -EINPROGRESS:
2295         case -EALREADY:
2296                 xprt_unlock_connect(xprt, transport);
2297                 return;
2298         case -EINVAL:
2299                 /* Happens, for instance, if the user specified a link
2300                  * local IPv6 address without a scope-id.
2301                  */
2302         case -ECONNREFUSED:
2303         case -ECONNRESET:
2304         case -ENETDOWN:
2305         case -ENETUNREACH:
2306         case -EHOSTUNREACH:
2307         case -EADDRINUSE:
2308         case -ENOBUFS:
2309                 /* xs_tcp_force_close() wakes tasks with a fixed error code.
2310                  * We need to wake them first to ensure the correct error code.
2311                  */
2312                 xprt_wake_pending_tasks(xprt, status);
2313                 xs_tcp_force_close(xprt);
2314                 goto out;
2315         }
2316         status = -EAGAIN;
2317 out:
2318         xprt_clear_connecting(xprt);
2319         xprt_unlock_connect(xprt, transport);
2320         xprt_wake_pending_tasks(xprt, status);
2321 }
2322
2323 /**
2324  * xs_connect - connect a socket to a remote endpoint
2325  * @xprt: pointer to transport structure
2326  * @task: address of RPC task that manages state of connect request
2327  *
2328  * TCP: If the remote end dropped the connection, delay reconnecting.
2329  *
2330  * UDP socket connects are synchronous, but we use a work queue anyway
2331  * to guarantee that even unprivileged user processes can set up a
2332  * socket on a privileged port.
2333  *
2334  * If a UDP socket connect fails, the delay behavior here prevents
2335  * retry floods (hard mounts).
2336  */
2337 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2338 {
2339         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2340         unsigned long delay = 0;
2341
2342         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2343
2344         if (transport->sock != NULL) {
2345                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2346                                 "seconds\n",
2347                                 xprt, xprt->reestablish_timeout / HZ);
2348
2349                 /* Start by resetting any existing state */
2350                 xs_reset_transport(transport);
2351
2352                 delay = xprt_reconnect_delay(xprt);
2353                 xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2354
2355         } else
2356                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2357
2358         queue_delayed_work(xprtiod_workqueue,
2359                         &transport->connect_worker,
2360                         delay);
2361 }
2362
2363 static void xs_wake_disconnect(struct sock_xprt *transport)
2364 {
2365         if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2366                 xs_tcp_force_close(&transport->xprt);
2367 }
2368
2369 static void xs_wake_write(struct sock_xprt *transport)
2370 {
2371         if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2372                 xprt_write_space(&transport->xprt);
2373 }
2374
2375 static void xs_wake_error(struct sock_xprt *transport)
2376 {
2377         int sockerr;
2378
2379         if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2380                 return;
2381         mutex_lock(&transport->recv_mutex);
2382         if (transport->sock == NULL)
2383                 goto out;
2384         if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2385                 goto out;
2386         sockerr = xchg(&transport->xprt_err, 0);
2387         if (sockerr < 0)
2388                 xprt_wake_pending_tasks(&transport->xprt, sockerr);
2389 out:
2390         mutex_unlock(&transport->recv_mutex);
2391 }
2392
2393 static void xs_wake_pending(struct sock_xprt *transport)
2394 {
2395         if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2396                 xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2397 }
2398
2399 static void xs_error_handle(struct work_struct *work)
2400 {
2401         struct sock_xprt *transport = container_of(work,
2402                         struct sock_xprt, error_worker);
2403
2404         xs_wake_disconnect(transport);
2405         xs_wake_write(transport);
2406         xs_wake_error(transport);
2407         xs_wake_pending(transport);
2408 }
2409
2410 /**
2411  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2412  * @xprt: rpc_xprt struct containing statistics
2413  * @seq: output file
2414  *
2415  */
2416 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2417 {
2418         long idle_time = 0;
2419
2420         if (xprt_connected(xprt))
2421                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2422
2423         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2424                         "%llu %llu %lu %llu %llu\n",
2425                         xprt->stat.bind_count,
2426                         xprt->stat.connect_count,
2427                         xprt->stat.connect_time / HZ,
2428                         idle_time,
2429                         xprt->stat.sends,
2430                         xprt->stat.recvs,
2431                         xprt->stat.bad_xids,
2432                         xprt->stat.req_u,
2433                         xprt->stat.bklog_u,
2434                         xprt->stat.max_slots,
2435                         xprt->stat.sending_u,
2436                         xprt->stat.pending_u);
2437 }
2438
2439 /**
2440  * xs_udp_print_stats - display UDP socket-specific stats
2441  * @xprt: rpc_xprt struct containing statistics
2442  * @seq: output file
2443  *
2444  */
2445 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2446 {
2447         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2448
2449         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2450                         "%lu %llu %llu\n",
2451                         transport->srcport,
2452                         xprt->stat.bind_count,
2453                         xprt->stat.sends,
2454                         xprt->stat.recvs,
2455                         xprt->stat.bad_xids,
2456                         xprt->stat.req_u,
2457                         xprt->stat.bklog_u,
2458                         xprt->stat.max_slots,
2459                         xprt->stat.sending_u,
2460                         xprt->stat.pending_u);
2461 }
2462
2463 /**
2464  * xs_tcp_print_stats - display TCP socket-specific stats
2465  * @xprt: rpc_xprt struct containing statistics
2466  * @seq: output file
2467  *
2468  */
2469 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2470 {
2471         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2472         long idle_time = 0;
2473
2474         if (xprt_connected(xprt))
2475                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2476
2477         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2478                         "%llu %llu %lu %llu %llu\n",
2479                         transport->srcport,
2480                         xprt->stat.bind_count,
2481                         xprt->stat.connect_count,
2482                         xprt->stat.connect_time / HZ,
2483                         idle_time,
2484                         xprt->stat.sends,
2485                         xprt->stat.recvs,
2486                         xprt->stat.bad_xids,
2487                         xprt->stat.req_u,
2488                         xprt->stat.bklog_u,
2489                         xprt->stat.max_slots,
2490                         xprt->stat.sending_u,
2491                         xprt->stat.pending_u);
2492 }
2493
2494 /*
2495  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2496  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2497  * to use the server side send routines.
2498  */
2499 static int bc_malloc(struct rpc_task *task)
2500 {
2501         struct rpc_rqst *rqst = task->tk_rqstp;
2502         size_t size = rqst->rq_callsize;
2503         struct page *page;
2504         struct rpc_buffer *buf;
2505
2506         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2507                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2508                           size);
2509                 return -EINVAL;
2510         }
2511
2512         page = alloc_page(GFP_KERNEL);
2513         if (!page)
2514                 return -ENOMEM;
2515
2516         buf = page_address(page);
2517         buf->len = PAGE_SIZE;
2518
2519         rqst->rq_buffer = buf->data;
2520         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2521         return 0;
2522 }
2523
2524 /*
2525  * Free the space allocated in the bc_alloc routine
2526  */
2527 static void bc_free(struct rpc_task *task)
2528 {
2529         void *buffer = task->tk_rqstp->rq_buffer;
2530         struct rpc_buffer *buf;
2531
2532         buf = container_of(buffer, struct rpc_buffer, data);
2533         free_page((unsigned long)buf);
2534 }
2535
2536 static int bc_sendto(struct rpc_rqst *req)
2537 {
2538         struct xdr_buf *xdr = &req->rq_snd_buf;
2539         struct sock_xprt *transport =
2540                         container_of(req->rq_xprt, struct sock_xprt, xprt);
2541         struct msghdr msg = {
2542                 .msg_flags      = 0,
2543         };
2544         rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2545                                          (u32)xdr->len);
2546         unsigned int sent = 0;
2547         int err;
2548
2549         req->rq_xtime = ktime_get();
2550         err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2551         xdr_free_bvec(xdr);
2552         if (err < 0 || sent != (xdr->len + sizeof(marker)))
2553                 return -EAGAIN;
2554         return sent;
2555 }
2556
2557 /**
2558  * bc_send_request - Send a backchannel Call on a TCP socket
2559  * @req: rpc_rqst containing Call message to be sent
2560  *
2561  * xpt_mutex ensures @rqstp's whole message is written to the socket
2562  * without interruption.
2563  *
2564  * Return values:
2565  *   %0 if the message was sent successfully
2566  *   %ENOTCONN if the message was not sent
2567  */
2568 static int bc_send_request(struct rpc_rqst *req)
2569 {
2570         struct svc_xprt *xprt;
2571         int len;
2572
2573         /*
2574          * Get the server socket associated with this callback xprt
2575          */
2576         xprt = req->rq_xprt->bc_xprt;
2577
2578         /*
2579          * Grab the mutex to serialize data as the connection is shared
2580          * with the fore channel
2581          */
2582         mutex_lock(&xprt->xpt_mutex);
2583         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2584                 len = -ENOTCONN;
2585         else
2586                 len = bc_sendto(req);
2587         mutex_unlock(&xprt->xpt_mutex);
2588
2589         if (len > 0)
2590                 len = 0;
2591
2592         return len;
2593 }
2594
2595 /*
2596  * The close routine. Since this is client initiated, we do nothing
2597  */
2598
2599 static void bc_close(struct rpc_xprt *xprt)
2600 {
2601         xprt_disconnect_done(xprt);
2602 }
2603
2604 /*
2605  * The xprt destroy routine. Again, because this connection is client
2606  * initiated, we do nothing
2607  */
2608
2609 static void bc_destroy(struct rpc_xprt *xprt)
2610 {
2611         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2612
2613         xs_xprt_free(xprt);
2614         module_put(THIS_MODULE);
2615 }
2616
2617 static const struct rpc_xprt_ops xs_local_ops = {
2618         .reserve_xprt           = xprt_reserve_xprt,
2619         .release_xprt           = xprt_release_xprt,
2620         .alloc_slot             = xprt_alloc_slot,
2621         .free_slot              = xprt_free_slot,
2622         .rpcbind                = xs_local_rpcbind,
2623         .set_port               = xs_local_set_port,
2624         .connect                = xs_local_connect,
2625         .buf_alloc              = rpc_malloc,
2626         .buf_free               = rpc_free,
2627         .prepare_request        = xs_stream_prepare_request,
2628         .send_request           = xs_local_send_request,
2629         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2630         .close                  = xs_close,
2631         .destroy                = xs_destroy,
2632         .print_stats            = xs_local_print_stats,
2633         .enable_swap            = xs_enable_swap,
2634         .disable_swap           = xs_disable_swap,
2635 };
2636
2637 static const struct rpc_xprt_ops xs_udp_ops = {
2638         .set_buffer_size        = xs_udp_set_buffer_size,
2639         .reserve_xprt           = xprt_reserve_xprt_cong,
2640         .release_xprt           = xprt_release_xprt_cong,
2641         .alloc_slot             = xprt_alloc_slot,
2642         .free_slot              = xprt_free_slot,
2643         .rpcbind                = rpcb_getport_async,
2644         .set_port               = xs_set_port,
2645         .connect                = xs_connect,
2646         .buf_alloc              = rpc_malloc,
2647         .buf_free               = rpc_free,
2648         .send_request           = xs_udp_send_request,
2649         .wait_for_reply_request = xprt_wait_for_reply_request_rtt,
2650         .timer                  = xs_udp_timer,
2651         .release_request        = xprt_release_rqst_cong,
2652         .close                  = xs_close,
2653         .destroy                = xs_destroy,
2654         .print_stats            = xs_udp_print_stats,
2655         .enable_swap            = xs_enable_swap,
2656         .disable_swap           = xs_disable_swap,
2657         .inject_disconnect      = xs_inject_disconnect,
2658 };
2659
2660 static const struct rpc_xprt_ops xs_tcp_ops = {
2661         .reserve_xprt           = xprt_reserve_xprt,
2662         .release_xprt           = xprt_release_xprt,
2663         .alloc_slot             = xprt_alloc_slot,
2664         .free_slot              = xprt_free_slot,
2665         .rpcbind                = rpcb_getport_async,
2666         .set_port               = xs_set_port,
2667         .connect                = xs_connect,
2668         .buf_alloc              = rpc_malloc,
2669         .buf_free               = rpc_free,
2670         .prepare_request        = xs_stream_prepare_request,
2671         .send_request           = xs_tcp_send_request,
2672         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2673         .close                  = xs_tcp_shutdown,
2674         .destroy                = xs_destroy,
2675         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2676         .print_stats            = xs_tcp_print_stats,
2677         .enable_swap            = xs_enable_swap,
2678         .disable_swap           = xs_disable_swap,
2679         .inject_disconnect      = xs_inject_disconnect,
2680 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2681         .bc_setup               = xprt_setup_bc,
2682         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2683         .bc_num_slots           = xprt_bc_max_slots,
2684         .bc_free_rqst           = xprt_free_bc_rqst,
2685         .bc_destroy             = xprt_destroy_bc,
2686 #endif
2687 };
2688
2689 /*
2690  * The rpc_xprt_ops for the server backchannel
2691  */
2692
2693 static const struct rpc_xprt_ops bc_tcp_ops = {
2694         .reserve_xprt           = xprt_reserve_xprt,
2695         .release_xprt           = xprt_release_xprt,
2696         .alloc_slot             = xprt_alloc_slot,
2697         .free_slot              = xprt_free_slot,
2698         .buf_alloc              = bc_malloc,
2699         .buf_free               = bc_free,
2700         .send_request           = bc_send_request,
2701         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2702         .close                  = bc_close,
2703         .destroy                = bc_destroy,
2704         .print_stats            = xs_tcp_print_stats,
2705         .enable_swap            = xs_enable_swap,
2706         .disable_swap           = xs_disable_swap,
2707         .inject_disconnect      = xs_inject_disconnect,
2708 };
2709
2710 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2711 {
2712         static const struct sockaddr_in sin = {
2713                 .sin_family             = AF_INET,
2714                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2715         };
2716         static const struct sockaddr_in6 sin6 = {
2717                 .sin6_family            = AF_INET6,
2718                 .sin6_addr              = IN6ADDR_ANY_INIT,
2719         };
2720
2721         switch (family) {
2722         case AF_LOCAL:
2723                 break;
2724         case AF_INET:
2725                 memcpy(sap, &sin, sizeof(sin));
2726                 break;
2727         case AF_INET6:
2728                 memcpy(sap, &sin6, sizeof(sin6));
2729                 break;
2730         default:
2731                 dprintk("RPC:       %s: Bad address family\n", __func__);
2732                 return -EAFNOSUPPORT;
2733         }
2734         return 0;
2735 }
2736
2737 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2738                                       unsigned int slot_table_size,
2739                                       unsigned int max_slot_table_size)
2740 {
2741         struct rpc_xprt *xprt;
2742         struct sock_xprt *new;
2743
2744         if (args->addrlen > sizeof(xprt->addr)) {
2745                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2746                 return ERR_PTR(-EBADF);
2747         }
2748
2749         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2750                         max_slot_table_size);
2751         if (xprt == NULL) {
2752                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2753                                 "rpc_xprt\n");
2754                 return ERR_PTR(-ENOMEM);
2755         }
2756
2757         new = container_of(xprt, struct sock_xprt, xprt);
2758         mutex_init(&new->recv_mutex);
2759         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2760         xprt->addrlen = args->addrlen;
2761         if (args->srcaddr)
2762                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2763         else {
2764                 int err;
2765                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2766                                         (struct sockaddr *)&new->srcaddr);
2767                 if (err != 0) {
2768                         xprt_free(xprt);
2769                         return ERR_PTR(err);
2770                 }
2771         }
2772
2773         return xprt;
2774 }
2775
2776 static const struct rpc_timeout xs_local_default_timeout = {
2777         .to_initval = 10 * HZ,
2778         .to_maxval = 10 * HZ,
2779         .to_retries = 2,
2780 };
2781
2782 /**
2783  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2784  * @args: rpc transport creation arguments
2785  *
2786  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2787  */
2788 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2789 {
2790         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2791         struct sock_xprt *transport;
2792         struct rpc_xprt *xprt;
2793         struct rpc_xprt *ret;
2794
2795         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2796                         xprt_max_tcp_slot_table_entries);
2797         if (IS_ERR(xprt))
2798                 return xprt;
2799         transport = container_of(xprt, struct sock_xprt, xprt);
2800
2801         xprt->prot = 0;
2802         xprt->xprt_class = &xs_local_transport;
2803         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2804
2805         xprt->bind_timeout = XS_BIND_TO;
2806         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2807         xprt->idle_timeout = XS_IDLE_DISC_TO;
2808
2809         xprt->ops = &xs_local_ops;
2810         xprt->timeout = &xs_local_default_timeout;
2811
2812         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2813         INIT_WORK(&transport->error_worker, xs_error_handle);
2814         INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2815
2816         switch (sun->sun_family) {
2817         case AF_LOCAL:
2818                 if (sun->sun_path[0] != '/') {
2819                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2820                                         sun->sun_path);
2821                         ret = ERR_PTR(-EINVAL);
2822                         goto out_err;
2823                 }
2824                 xprt_set_bound(xprt);
2825                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2826                 ret = ERR_PTR(xs_local_setup_socket(transport));
2827                 if (ret)
2828                         goto out_err;
2829                 break;
2830         default:
2831                 ret = ERR_PTR(-EAFNOSUPPORT);
2832                 goto out_err;
2833         }
2834
2835         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2836                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2837
2838         if (try_module_get(THIS_MODULE))
2839                 return xprt;
2840         ret = ERR_PTR(-EINVAL);
2841 out_err:
2842         xs_xprt_free(xprt);
2843         return ret;
2844 }
2845
2846 static const struct rpc_timeout xs_udp_default_timeout = {
2847         .to_initval = 5 * HZ,
2848         .to_maxval = 30 * HZ,
2849         .to_increment = 5 * HZ,
2850         .to_retries = 5,
2851 };
2852
2853 /**
2854  * xs_setup_udp - Set up transport to use a UDP socket
2855  * @args: rpc transport creation arguments
2856  *
2857  */
2858 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2859 {
2860         struct sockaddr *addr = args->dstaddr;
2861         struct rpc_xprt *xprt;
2862         struct sock_xprt *transport;
2863         struct rpc_xprt *ret;
2864
2865         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2866                         xprt_udp_slot_table_entries);
2867         if (IS_ERR(xprt))
2868                 return xprt;
2869         transport = container_of(xprt, struct sock_xprt, xprt);
2870
2871         xprt->prot = IPPROTO_UDP;
2872         xprt->xprt_class = &xs_udp_transport;
2873         /* XXX: header size can vary due to auth type, IPv6, etc. */
2874         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2875
2876         xprt->bind_timeout = XS_BIND_TO;
2877         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2878         xprt->idle_timeout = XS_IDLE_DISC_TO;
2879
2880         xprt->ops = &xs_udp_ops;
2881
2882         xprt->timeout = &xs_udp_default_timeout;
2883
2884         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2885         INIT_WORK(&transport->error_worker, xs_error_handle);
2886         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2887
2888         switch (addr->sa_family) {
2889         case AF_INET:
2890                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2891                         xprt_set_bound(xprt);
2892
2893                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2894                 break;
2895         case AF_INET6:
2896                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2897                         xprt_set_bound(xprt);
2898
2899                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2900                 break;
2901         default:
2902                 ret = ERR_PTR(-EAFNOSUPPORT);
2903                 goto out_err;
2904         }
2905
2906         if (xprt_bound(xprt))
2907                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2908                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2909                                 xprt->address_strings[RPC_DISPLAY_PORT],
2910                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2911         else
2912                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2913                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2914                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2915
2916         if (try_module_get(THIS_MODULE))
2917                 return xprt;
2918         ret = ERR_PTR(-EINVAL);
2919 out_err:
2920         xs_xprt_free(xprt);
2921         return ret;
2922 }
2923
2924 static const struct rpc_timeout xs_tcp_default_timeout = {
2925         .to_initval = 60 * HZ,
2926         .to_maxval = 60 * HZ,
2927         .to_retries = 2,
2928 };
2929
2930 /**
2931  * xs_setup_tcp - Set up transport to use a TCP socket
2932  * @args: rpc transport creation arguments
2933  *
2934  */
2935 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2936 {
2937         struct sockaddr *addr = args->dstaddr;
2938         struct rpc_xprt *xprt;
2939         struct sock_xprt *transport;
2940         struct rpc_xprt *ret;
2941         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2942
2943         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2944                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2945
2946         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2947                         max_slot_table_size);
2948         if (IS_ERR(xprt))
2949                 return xprt;
2950         transport = container_of(xprt, struct sock_xprt, xprt);
2951
2952         xprt->prot = IPPROTO_TCP;
2953         xprt->xprt_class = &xs_tcp_transport;
2954         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2955
2956         xprt->bind_timeout = XS_BIND_TO;
2957         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2958         xprt->idle_timeout = XS_IDLE_DISC_TO;
2959
2960         xprt->ops = &xs_tcp_ops;
2961         xprt->timeout = &xs_tcp_default_timeout;
2962
2963         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2964         xprt->connect_timeout = xprt->timeout->to_initval *
2965                 (xprt->timeout->to_retries + 1);
2966
2967         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2968         INIT_WORK(&transport->error_worker, xs_error_handle);
2969         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2970
2971         switch (addr->sa_family) {
2972         case AF_INET:
2973                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2974                         xprt_set_bound(xprt);
2975
2976                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2977                 break;
2978         case AF_INET6:
2979                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2980                         xprt_set_bound(xprt);
2981
2982                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2983                 break;
2984         default:
2985                 ret = ERR_PTR(-EAFNOSUPPORT);
2986                 goto out_err;
2987         }
2988
2989         if (xprt_bound(xprt))
2990                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2991                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2992                                 xprt->address_strings[RPC_DISPLAY_PORT],
2993                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2994         else
2995                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2996                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2997                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2998
2999         if (try_module_get(THIS_MODULE))
3000                 return xprt;
3001         ret = ERR_PTR(-EINVAL);
3002 out_err:
3003         xs_xprt_free(xprt);
3004         return ret;
3005 }
3006
3007 /**
3008  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3009  * @args: rpc transport creation arguments
3010  *
3011  */
3012 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3013 {
3014         struct sockaddr *addr = args->dstaddr;
3015         struct rpc_xprt *xprt;
3016         struct sock_xprt *transport;
3017         struct svc_sock *bc_sock;
3018         struct rpc_xprt *ret;
3019
3020         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3021                         xprt_tcp_slot_table_entries);
3022         if (IS_ERR(xprt))
3023                 return xprt;
3024         transport = container_of(xprt, struct sock_xprt, xprt);
3025
3026         xprt->prot = IPPROTO_TCP;
3027         xprt->xprt_class = &xs_bc_tcp_transport;
3028         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3029         xprt->timeout = &xs_tcp_default_timeout;
3030
3031         /* backchannel */
3032         xprt_set_bound(xprt);
3033         xprt->bind_timeout = 0;
3034         xprt->reestablish_timeout = 0;
3035         xprt->idle_timeout = 0;
3036
3037         xprt->ops = &bc_tcp_ops;
3038
3039         switch (addr->sa_family) {
3040         case AF_INET:
3041                 xs_format_peer_addresses(xprt, "tcp",
3042                                          RPCBIND_NETID_TCP);
3043                 break;
3044         case AF_INET6:
3045                 xs_format_peer_addresses(xprt, "tcp",
3046                                    RPCBIND_NETID_TCP6);
3047                 break;
3048         default:
3049                 ret = ERR_PTR(-EAFNOSUPPORT);
3050                 goto out_err;
3051         }
3052
3053         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3054                         xprt->address_strings[RPC_DISPLAY_ADDR],
3055                         xprt->address_strings[RPC_DISPLAY_PORT],
3056                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3057
3058         /*
3059          * Once we've associated a backchannel xprt with a connection,
3060          * we want to keep it around as long as the connection lasts,
3061          * in case we need to start using it for a backchannel again;
3062          * this reference won't be dropped until bc_xprt is destroyed.
3063          */
3064         xprt_get(xprt);
3065         args->bc_xprt->xpt_bc_xprt = xprt;
3066         xprt->bc_xprt = args->bc_xprt;
3067         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3068         transport->sock = bc_sock->sk_sock;
3069         transport->inet = bc_sock->sk_sk;
3070
3071         /*
3072          * Since we don't want connections for the backchannel, we set
3073          * the xprt status to connected
3074          */
3075         xprt_set_connected(xprt);
3076
3077         if (try_module_get(THIS_MODULE))
3078                 return xprt;
3079
3080         args->bc_xprt->xpt_bc_xprt = NULL;
3081         args->bc_xprt->xpt_bc_xps = NULL;
3082         xprt_put(xprt);
3083         ret = ERR_PTR(-EINVAL);
3084 out_err:
3085         xs_xprt_free(xprt);
3086         return ret;
3087 }
3088
3089 static struct xprt_class        xs_local_transport = {
3090         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3091         .name           = "named UNIX socket",
3092         .owner          = THIS_MODULE,
3093         .ident          = XPRT_TRANSPORT_LOCAL,
3094         .setup          = xs_setup_local,
3095         .netid          = { "" },
3096 };
3097
3098 static struct xprt_class        xs_udp_transport = {
3099         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3100         .name           = "udp",
3101         .owner          = THIS_MODULE,
3102         .ident          = XPRT_TRANSPORT_UDP,
3103         .setup          = xs_setup_udp,
3104         .netid          = { "udp", "udp6", "" },
3105 };
3106
3107 static struct xprt_class        xs_tcp_transport = {
3108         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3109         .name           = "tcp",
3110         .owner          = THIS_MODULE,
3111         .ident          = XPRT_TRANSPORT_TCP,
3112         .setup          = xs_setup_tcp,
3113         .netid          = { "tcp", "tcp6", "" },
3114 };
3115
3116 static struct xprt_class        xs_bc_tcp_transport = {
3117         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3118         .name           = "tcp NFSv4.1 backchannel",
3119         .owner          = THIS_MODULE,
3120         .ident          = XPRT_TRANSPORT_BC_TCP,
3121         .setup          = xs_setup_bc_tcp,
3122         .netid          = { "" },
3123 };
3124
3125 /**
3126  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3127  *
3128  */
3129 int init_socket_xprt(void)
3130 {
3131         if (!sunrpc_table_header)
3132                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3133
3134         xprt_register_transport(&xs_local_transport);
3135         xprt_register_transport(&xs_udp_transport);
3136         xprt_register_transport(&xs_tcp_transport);
3137         xprt_register_transport(&xs_bc_tcp_transport);
3138
3139         return 0;
3140 }
3141
3142 /**
3143  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3144  *
3145  */
3146 void cleanup_socket_xprt(void)
3147 {
3148         if (sunrpc_table_header) {
3149                 unregister_sysctl_table(sunrpc_table_header);
3150                 sunrpc_table_header = NULL;
3151         }
3152
3153         xprt_unregister_transport(&xs_local_transport);
3154         xprt_unregister_transport(&xs_udp_transport);
3155         xprt_unregister_transport(&xs_tcp_transport);
3156         xprt_unregister_transport(&xs_bc_tcp_transport);
3157 }
3158
3159 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3160 {
3161         return param_set_uint_minmax(val, kp,
3162                         RPC_MIN_RESVPORT,
3163                         RPC_MAX_RESVPORT);
3164 }
3165
3166 static const struct kernel_param_ops param_ops_portnr = {
3167         .set = param_set_portnr,
3168         .get = param_get_uint,
3169 };
3170
3171 #define param_check_portnr(name, p) \
3172         __param_check(name, p, unsigned int);
3173
3174 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3175 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3176
3177 static int param_set_slot_table_size(const char *val,
3178                                      const struct kernel_param *kp)
3179 {
3180         return param_set_uint_minmax(val, kp,
3181                         RPC_MIN_SLOT_TABLE,
3182                         RPC_MAX_SLOT_TABLE);
3183 }
3184
3185 static const struct kernel_param_ops param_ops_slot_table_size = {
3186         .set = param_set_slot_table_size,
3187         .get = param_get_uint,
3188 };
3189
3190 #define param_check_slot_table_size(name, p) \
3191         __param_check(name, p, unsigned int);
3192
3193 static int param_set_max_slot_table_size(const char *val,
3194                                      const struct kernel_param *kp)
3195 {
3196         return param_set_uint_minmax(val, kp,
3197                         RPC_MIN_SLOT_TABLE,
3198                         RPC_MAX_SLOT_TABLE_LIMIT);
3199 }
3200
3201 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3202         .set = param_set_max_slot_table_size,
3203         .get = param_get_uint,
3204 };
3205
3206 #define param_check_max_slot_table_size(name, p) \
3207         __param_check(name, p, unsigned int);
3208
3209 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3210                    slot_table_size, 0644);
3211 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3212                    max_slot_table_size, 0644);
3213 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3214                    slot_table_size, 0644);