Merge tag 'fixes-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux-2.6-microblaze.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 /*
95  * FIXME: changing the UDP slot table size should also resize the UDP
96  *        socket buffers for existing UDP transports
97  */
98 static struct ctl_table xs_tunables_table[] = {
99         {
100                 .procname       = "udp_slot_table_entries",
101                 .data           = &xprt_udp_slot_table_entries,
102                 .maxlen         = sizeof(unsigned int),
103                 .mode           = 0644,
104                 .proc_handler   = proc_dointvec_minmax,
105                 .extra1         = &min_slot_table_size,
106                 .extra2         = &max_slot_table_size
107         },
108         {
109                 .procname       = "tcp_slot_table_entries",
110                 .data           = &xprt_tcp_slot_table_entries,
111                 .maxlen         = sizeof(unsigned int),
112                 .mode           = 0644,
113                 .proc_handler   = proc_dointvec_minmax,
114                 .extra1         = &min_slot_table_size,
115                 .extra2         = &max_slot_table_size
116         },
117         {
118                 .procname       = "tcp_max_slot_table_entries",
119                 .data           = &xprt_max_tcp_slot_table_entries,
120                 .maxlen         = sizeof(unsigned int),
121                 .mode           = 0644,
122                 .proc_handler   = proc_dointvec_minmax,
123                 .extra1         = &min_slot_table_size,
124                 .extra2         = &max_tcp_slot_table_limit
125         },
126         {
127                 .procname       = "min_resvport",
128                 .data           = &xprt_min_resvport,
129                 .maxlen         = sizeof(unsigned int),
130                 .mode           = 0644,
131                 .proc_handler   = proc_dointvec_minmax,
132                 .extra1         = &xprt_min_resvport_limit,
133                 .extra2         = &xprt_max_resvport_limit
134         },
135         {
136                 .procname       = "max_resvport",
137                 .data           = &xprt_max_resvport,
138                 .maxlen         = sizeof(unsigned int),
139                 .mode           = 0644,
140                 .proc_handler   = proc_dointvec_minmax,
141                 .extra1         = &xprt_min_resvport_limit,
142                 .extra2         = &xprt_max_resvport_limit
143         },
144         {
145                 .procname       = "tcp_fin_timeout",
146                 .data           = &xs_tcp_fin_timeout,
147                 .maxlen         = sizeof(xs_tcp_fin_timeout),
148                 .mode           = 0644,
149                 .proc_handler   = proc_dointvec_jiffies,
150         },
151         { },
152 };
153
154 static struct ctl_table sunrpc_table[] = {
155         {
156                 .procname       = "sunrpc",
157                 .mode           = 0555,
158                 .child          = xs_tunables_table
159         },
160         { },
161 };
162
163 /*
164  * Wait duration for a reply from the RPC portmapper.
165  */
166 #define XS_BIND_TO              (60U * HZ)
167
168 /*
169  * Delay if a UDP socket connect error occurs.  This is most likely some
170  * kind of resource problem on the local host.
171  */
172 #define XS_UDP_REEST_TO         (2U * HZ)
173
174 /*
175  * The reestablish timeout allows clients to delay for a bit before attempting
176  * to reconnect to a server that just dropped our connection.
177  *
178  * We implement an exponential backoff when trying to reestablish a TCP
179  * transport connection with the server.  Some servers like to drop a TCP
180  * connection when they are overworked, so we start with a short timeout and
181  * increase over time if the server is down or not responding.
182  */
183 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
184
185 /*
186  * TCP idle timeout; client drops the transport socket if it is idle
187  * for this long.  Note that we also timeout UDP sockets to prevent
188  * holding port numbers when there is no RPC traffic.
189  */
190 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
191
192 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
193 # undef  RPC_DEBUG_DATA
194 # define RPCDBG_FACILITY        RPCDBG_TRANS
195 #endif
196
197 #ifdef RPC_DEBUG_DATA
198 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
199 {
200         u8 *buf = (u8 *) packet;
201         int j;
202
203         dprintk("RPC:       %s\n", msg);
204         for (j = 0; j < count && j < 128; j += 4) {
205                 if (!(j & 31)) {
206                         if (j)
207                                 dprintk("\n");
208                         dprintk("0x%04x ", j);
209                 }
210                 dprintk("%02x%02x%02x%02x ",
211                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
212         }
213         dprintk("\n");
214 }
215 #else
216 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
217 {
218         /* NOP */
219 }
220 #endif
221
222 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
223 {
224         return (struct rpc_xprt *) sk->sk_user_data;
225 }
226
227 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
228 {
229         return (struct sockaddr *) &xprt->addr;
230 }
231
232 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
233 {
234         return (struct sockaddr_un *) &xprt->addr;
235 }
236
237 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
238 {
239         return (struct sockaddr_in *) &xprt->addr;
240 }
241
242 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
243 {
244         return (struct sockaddr_in6 *) &xprt->addr;
245 }
246
247 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
248 {
249         struct sockaddr *sap = xs_addr(xprt);
250         struct sockaddr_in6 *sin6;
251         struct sockaddr_in *sin;
252         struct sockaddr_un *sun;
253         char buf[128];
254
255         switch (sap->sa_family) {
256         case AF_LOCAL:
257                 sun = xs_addr_un(xprt);
258                 strlcpy(buf, sun->sun_path, sizeof(buf));
259                 xprt->address_strings[RPC_DISPLAY_ADDR] =
260                                                 kstrdup(buf, GFP_KERNEL);
261                 break;
262         case AF_INET:
263                 (void)rpc_ntop(sap, buf, sizeof(buf));
264                 xprt->address_strings[RPC_DISPLAY_ADDR] =
265                                                 kstrdup(buf, GFP_KERNEL);
266                 sin = xs_addr_in(xprt);
267                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
268                 break;
269         case AF_INET6:
270                 (void)rpc_ntop(sap, buf, sizeof(buf));
271                 xprt->address_strings[RPC_DISPLAY_ADDR] =
272                                                 kstrdup(buf, GFP_KERNEL);
273                 sin6 = xs_addr_in6(xprt);
274                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
275                 break;
276         default:
277                 BUG();
278         }
279
280         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
281 }
282
283 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
284 {
285         struct sockaddr *sap = xs_addr(xprt);
286         char buf[128];
287
288         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
289         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
290
291         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
292         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
293 }
294
295 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
296                                      const char *protocol,
297                                      const char *netid)
298 {
299         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
300         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
301         xs_format_common_peer_addresses(xprt);
302         xs_format_common_peer_ports(xprt);
303 }
304
305 static void xs_update_peer_port(struct rpc_xprt *xprt)
306 {
307         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
308         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
309
310         xs_format_common_peer_ports(xprt);
311 }
312
313 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
314 {
315         unsigned int i;
316
317         for (i = 0; i < RPC_DISPLAY_MAX; i++)
318                 switch (i) {
319                 case RPC_DISPLAY_PROTO:
320                 case RPC_DISPLAY_NETID:
321                         continue;
322                 default:
323                         kfree(xprt->address_strings[i]);
324                 }
325 }
326
327 static size_t
328 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
329 {
330         size_t i,n;
331
332         if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
333                 return want;
334         n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
335         for (i = 0; i < n; i++) {
336                 if (buf->pages[i])
337                         continue;
338                 buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
339                 if (!buf->pages[i]) {
340                         i *= PAGE_SIZE;
341                         return i > buf->page_base ? i - buf->page_base : 0;
342                 }
343         }
344         return want;
345 }
346
347 static ssize_t
348 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
349 {
350         ssize_t ret;
351         if (seek != 0)
352                 iov_iter_advance(&msg->msg_iter, seek);
353         ret = sock_recvmsg(sock, msg, flags);
354         return ret > 0 ? ret + seek : ret;
355 }
356
357 static ssize_t
358 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
359                 struct kvec *kvec, size_t count, size_t seek)
360 {
361         iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
362         return xs_sock_recvmsg(sock, msg, flags, seek);
363 }
364
365 static ssize_t
366 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
367                 struct bio_vec *bvec, unsigned long nr, size_t count,
368                 size_t seek)
369 {
370         iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
371         return xs_sock_recvmsg(sock, msg, flags, seek);
372 }
373
374 static ssize_t
375 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
376                 size_t count)
377 {
378         iov_iter_discard(&msg->msg_iter, READ, count);
379         return sock_recvmsg(sock, msg, flags);
380 }
381
382 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
383 static void
384 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
385 {
386         struct bvec_iter bi = {
387                 .bi_size = count,
388         };
389         struct bio_vec bv;
390
391         bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
392         for_each_bvec(bv, bvec, bi, bi)
393                 flush_dcache_page(bv.bv_page);
394 }
395 #else
396 static inline void
397 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
398 {
399 }
400 #endif
401
402 static ssize_t
403 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
404                 struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
405 {
406         size_t want, seek_init = seek, offset = 0;
407         ssize_t ret;
408
409         want = min_t(size_t, count, buf->head[0].iov_len);
410         if (seek < want) {
411                 ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
412                 if (ret <= 0)
413                         goto sock_err;
414                 offset += ret;
415                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
416                         goto out;
417                 if (ret != want)
418                         goto out;
419                 seek = 0;
420         } else {
421                 seek -= want;
422                 offset += want;
423         }
424
425         want = xs_alloc_sparse_pages(buf,
426                         min_t(size_t, count - offset, buf->page_len),
427                         GFP_KERNEL);
428         if (seek < want) {
429                 ret = xs_read_bvec(sock, msg, flags, buf->bvec,
430                                 xdr_buf_pagecount(buf),
431                                 want + buf->page_base,
432                                 seek + buf->page_base);
433                 if (ret <= 0)
434                         goto sock_err;
435                 xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
436                 ret -= buf->page_base;
437                 offset += ret;
438                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
439                         goto out;
440                 if (ret != want)
441                         goto out;
442                 seek = 0;
443         } else {
444                 seek -= want;
445                 offset += want;
446         }
447
448         want = min_t(size_t, count - offset, buf->tail[0].iov_len);
449         if (seek < want) {
450                 ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
451                 if (ret <= 0)
452                         goto sock_err;
453                 offset += ret;
454                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
455                         goto out;
456                 if (ret != want)
457                         goto out;
458         } else if (offset < seek_init)
459                 offset = seek_init;
460         ret = -EMSGSIZE;
461 out:
462         *read = offset - seek_init;
463         return ret;
464 sock_err:
465         offset += seek;
466         goto out;
467 }
468
469 static void
470 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
471 {
472         if (!transport->recv.copied) {
473                 if (buf->head[0].iov_len >= transport->recv.offset)
474                         memcpy(buf->head[0].iov_base,
475                                         &transport->recv.xid,
476                                         transport->recv.offset);
477                 transport->recv.copied = transport->recv.offset;
478         }
479 }
480
481 static bool
482 xs_read_stream_request_done(struct sock_xprt *transport)
483 {
484         return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
485 }
486
487 static void
488 xs_read_stream_check_eor(struct sock_xprt *transport,
489                 struct msghdr *msg)
490 {
491         if (xs_read_stream_request_done(transport))
492                 msg->msg_flags |= MSG_EOR;
493 }
494
495 static ssize_t
496 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
497                 int flags, struct rpc_rqst *req)
498 {
499         struct xdr_buf *buf = &req->rq_private_buf;
500         size_t want, read;
501         ssize_t ret;
502
503         xs_read_header(transport, buf);
504
505         want = transport->recv.len - transport->recv.offset;
506         if (want != 0) {
507                 ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
508                                 transport->recv.copied + want,
509                                 transport->recv.copied,
510                                 &read);
511                 transport->recv.offset += read;
512                 transport->recv.copied += read;
513         }
514
515         if (transport->recv.offset == transport->recv.len)
516                 xs_read_stream_check_eor(transport, msg);
517
518         if (want == 0)
519                 return 0;
520
521         switch (ret) {
522         default:
523                 break;
524         case -EFAULT:
525         case -EMSGSIZE:
526                 msg->msg_flags |= MSG_TRUNC;
527                 return read;
528         case 0:
529                 return -ESHUTDOWN;
530         }
531         return ret < 0 ? ret : read;
532 }
533
534 static size_t
535 xs_read_stream_headersize(bool isfrag)
536 {
537         if (isfrag)
538                 return sizeof(__be32);
539         return 3 * sizeof(__be32);
540 }
541
542 static ssize_t
543 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
544                 int flags, size_t want, size_t seek)
545 {
546         struct kvec kvec = {
547                 .iov_base = &transport->recv.fraghdr,
548                 .iov_len = want,
549         };
550         return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
551 }
552
553 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
554 static ssize_t
555 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
556 {
557         struct rpc_xprt *xprt = &transport->xprt;
558         struct rpc_rqst *req;
559         ssize_t ret;
560
561         /* Look up and lock the request corresponding to the given XID */
562         req = xprt_lookup_bc_request(xprt, transport->recv.xid);
563         if (!req) {
564                 printk(KERN_WARNING "Callback slot table overflowed\n");
565                 return -ESHUTDOWN;
566         }
567         if (transport->recv.copied && !req->rq_private_buf.len)
568                 return -ESHUTDOWN;
569
570         ret = xs_read_stream_request(transport, msg, flags, req);
571         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
572                 xprt_complete_bc_request(req, transport->recv.copied);
573         else
574                 req->rq_private_buf.len = transport->recv.copied;
575
576         return ret;
577 }
578 #else /* CONFIG_SUNRPC_BACKCHANNEL */
579 static ssize_t
580 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
581 {
582         return -ESHUTDOWN;
583 }
584 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
585
586 static ssize_t
587 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
588 {
589         struct rpc_xprt *xprt = &transport->xprt;
590         struct rpc_rqst *req;
591         ssize_t ret = 0;
592
593         /* Look up and lock the request corresponding to the given XID */
594         spin_lock(&xprt->queue_lock);
595         req = xprt_lookup_rqst(xprt, transport->recv.xid);
596         if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
597                 msg->msg_flags |= MSG_TRUNC;
598                 goto out;
599         }
600         xprt_pin_rqst(req);
601         spin_unlock(&xprt->queue_lock);
602
603         ret = xs_read_stream_request(transport, msg, flags, req);
604
605         spin_lock(&xprt->queue_lock);
606         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
607                 xprt_complete_rqst(req->rq_task, transport->recv.copied);
608         else
609                 req->rq_private_buf.len = transport->recv.copied;
610         xprt_unpin_rqst(req);
611 out:
612         spin_unlock(&xprt->queue_lock);
613         return ret;
614 }
615
616 static ssize_t
617 xs_read_stream(struct sock_xprt *transport, int flags)
618 {
619         struct msghdr msg = { 0 };
620         size_t want, read = 0;
621         ssize_t ret = 0;
622
623         if (transport->recv.len == 0) {
624                 want = xs_read_stream_headersize(transport->recv.copied != 0);
625                 ret = xs_read_stream_header(transport, &msg, flags, want,
626                                 transport->recv.offset);
627                 if (ret <= 0)
628                         goto out_err;
629                 transport->recv.offset = ret;
630                 if (transport->recv.offset != want)
631                         return transport->recv.offset;
632                 transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
633                         RPC_FRAGMENT_SIZE_MASK;
634                 transport->recv.offset -= sizeof(transport->recv.fraghdr);
635                 read = ret;
636         }
637
638         switch (be32_to_cpu(transport->recv.calldir)) {
639         default:
640                 msg.msg_flags |= MSG_TRUNC;
641                 break;
642         case RPC_CALL:
643                 ret = xs_read_stream_call(transport, &msg, flags);
644                 break;
645         case RPC_REPLY:
646                 ret = xs_read_stream_reply(transport, &msg, flags);
647         }
648         if (msg.msg_flags & MSG_TRUNC) {
649                 transport->recv.calldir = cpu_to_be32(-1);
650                 transport->recv.copied = -1;
651         }
652         if (ret < 0)
653                 goto out_err;
654         read += ret;
655         if (transport->recv.offset < transport->recv.len) {
656                 if (!(msg.msg_flags & MSG_TRUNC))
657                         return read;
658                 msg.msg_flags = 0;
659                 ret = xs_read_discard(transport->sock, &msg, flags,
660                                 transport->recv.len - transport->recv.offset);
661                 if (ret <= 0)
662                         goto out_err;
663                 transport->recv.offset += ret;
664                 read += ret;
665                 if (transport->recv.offset != transport->recv.len)
666                         return read;
667         }
668         if (xs_read_stream_request_done(transport)) {
669                 trace_xs_stream_read_request(transport);
670                 transport->recv.copied = 0;
671         }
672         transport->recv.offset = 0;
673         transport->recv.len = 0;
674         return read;
675 out_err:
676         return ret != 0 ? ret : -ESHUTDOWN;
677 }
678
679 static __poll_t xs_poll_socket(struct sock_xprt *transport)
680 {
681         return transport->sock->ops->poll(transport->file, transport->sock,
682                         NULL);
683 }
684
685 static bool xs_poll_socket_readable(struct sock_xprt *transport)
686 {
687         __poll_t events = xs_poll_socket(transport);
688
689         return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
690 }
691
692 static void xs_poll_check_readable(struct sock_xprt *transport)
693 {
694
695         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
696         if (!xs_poll_socket_readable(transport))
697                 return;
698         if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
699                 queue_work(xprtiod_workqueue, &transport->recv_worker);
700 }
701
702 static void xs_stream_data_receive(struct sock_xprt *transport)
703 {
704         size_t read = 0;
705         ssize_t ret = 0;
706
707         mutex_lock(&transport->recv_mutex);
708         if (transport->sock == NULL)
709                 goto out;
710         for (;;) {
711                 ret = xs_read_stream(transport, MSG_DONTWAIT);
712                 if (ret < 0)
713                         break;
714                 read += ret;
715                 cond_resched();
716         }
717         if (ret == -ESHUTDOWN)
718                 kernel_sock_shutdown(transport->sock, SHUT_RDWR);
719         else
720                 xs_poll_check_readable(transport);
721 out:
722         mutex_unlock(&transport->recv_mutex);
723         trace_xs_stream_read_data(&transport->xprt, ret, read);
724 }
725
726 static void xs_stream_data_receive_workfn(struct work_struct *work)
727 {
728         struct sock_xprt *transport =
729                 container_of(work, struct sock_xprt, recv_worker);
730         unsigned int pflags = memalloc_nofs_save();
731
732         xs_stream_data_receive(transport);
733         memalloc_nofs_restore(pflags);
734 }
735
736 static void
737 xs_stream_reset_connect(struct sock_xprt *transport)
738 {
739         transport->recv.offset = 0;
740         transport->recv.len = 0;
741         transport->recv.copied = 0;
742         transport->xmit.offset = 0;
743 }
744
745 static void
746 xs_stream_start_connect(struct sock_xprt *transport)
747 {
748         transport->xprt.stat.connect_count++;
749         transport->xprt.stat.connect_start = jiffies;
750 }
751
752 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
753
754 /**
755  * xs_nospace - handle transmit was incomplete
756  * @req: pointer to RPC request
757  *
758  */
759 static int xs_nospace(struct rpc_rqst *req)
760 {
761         struct rpc_xprt *xprt = req->rq_xprt;
762         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
763         struct sock *sk = transport->inet;
764         int ret = -EAGAIN;
765
766         trace_rpc_socket_nospace(req, transport);
767
768         /* Protect against races with write_space */
769         spin_lock(&xprt->transport_lock);
770
771         /* Don't race with disconnect */
772         if (xprt_connected(xprt)) {
773                 /* wait for more buffer space */
774                 sk->sk_write_pending++;
775                 xprt_wait_for_buffer_space(xprt);
776         } else
777                 ret = -ENOTCONN;
778
779         spin_unlock(&xprt->transport_lock);
780
781         /* Race breaker in case memory is freed before above code is called */
782         if (ret == -EAGAIN) {
783                 struct socket_wq *wq;
784
785                 rcu_read_lock();
786                 wq = rcu_dereference(sk->sk_wq);
787                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
788                 rcu_read_unlock();
789
790                 sk->sk_write_space(sk);
791         }
792         return ret;
793 }
794
795 static void
796 xs_stream_prepare_request(struct rpc_rqst *req)
797 {
798         xdr_free_bvec(&req->rq_rcv_buf);
799         req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
800 }
801
802 /*
803  * Determine if the previous message in the stream was aborted before it
804  * could complete transmission.
805  */
806 static bool
807 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
808 {
809         return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
810 }
811
812 /*
813  * Return the stream record marker field for a record of length < 2^31-1
814  */
815 static rpc_fraghdr
816 xs_stream_record_marker(struct xdr_buf *xdr)
817 {
818         if (!xdr->len)
819                 return 0;
820         return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
821 }
822
823 /**
824  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
825  * @req: pointer to RPC request
826  *
827  * Return values:
828  *        0:    The request has been sent
829  *   EAGAIN:    The socket was blocked, please call again later to
830  *              complete the request
831  * ENOTCONN:    Caller needs to invoke connect logic then call again
832  *    other:    Some other error occurred, the request was not sent
833  */
834 static int xs_local_send_request(struct rpc_rqst *req)
835 {
836         struct rpc_xprt *xprt = req->rq_xprt;
837         struct sock_xprt *transport =
838                                 container_of(xprt, struct sock_xprt, xprt);
839         struct xdr_buf *xdr = &req->rq_snd_buf;
840         rpc_fraghdr rm = xs_stream_record_marker(xdr);
841         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
842         struct msghdr msg = {
843                 .msg_flags      = XS_SENDMSG_FLAGS,
844         };
845         unsigned int sent;
846         int status;
847
848         /* Close the stream if the previous transmission was incomplete */
849         if (xs_send_request_was_aborted(transport, req)) {
850                 xs_close(xprt);
851                 return -ENOTCONN;
852         }
853
854         xs_pktdump("packet data:",
855                         req->rq_svec->iov_base, req->rq_svec->iov_len);
856
857         req->rq_xtime = ktime_get();
858         status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
859                                    transport->xmit.offset, rm, &sent);
860         dprintk("RPC:       %s(%u) = %d\n",
861                         __func__, xdr->len - transport->xmit.offset, status);
862
863         if (status == -EAGAIN && sock_writeable(transport->inet))
864                 status = -ENOBUFS;
865
866         if (likely(sent > 0) || status == 0) {
867                 transport->xmit.offset += sent;
868                 req->rq_bytes_sent = transport->xmit.offset;
869                 if (likely(req->rq_bytes_sent >= msglen)) {
870                         req->rq_xmit_bytes_sent += transport->xmit.offset;
871                         transport->xmit.offset = 0;
872                         return 0;
873                 }
874                 status = -EAGAIN;
875         }
876
877         switch (status) {
878         case -ENOBUFS:
879                 break;
880         case -EAGAIN:
881                 status = xs_nospace(req);
882                 break;
883         default:
884                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
885                         -status);
886                 fallthrough;
887         case -EPIPE:
888                 xs_close(xprt);
889                 status = -ENOTCONN;
890         }
891
892         return status;
893 }
894
895 /**
896  * xs_udp_send_request - write an RPC request to a UDP socket
897  * @req: pointer to RPC request
898  *
899  * Return values:
900  *        0:    The request has been sent
901  *   EAGAIN:    The socket was blocked, please call again later to
902  *              complete the request
903  * ENOTCONN:    Caller needs to invoke connect logic then call again
904  *    other:    Some other error occurred, the request was not sent
905  */
906 static int xs_udp_send_request(struct rpc_rqst *req)
907 {
908         struct rpc_xprt *xprt = req->rq_xprt;
909         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
910         struct xdr_buf *xdr = &req->rq_snd_buf;
911         struct msghdr msg = {
912                 .msg_name       = xs_addr(xprt),
913                 .msg_namelen    = xprt->addrlen,
914                 .msg_flags      = XS_SENDMSG_FLAGS,
915         };
916         unsigned int sent;
917         int status;
918
919         xs_pktdump("packet data:",
920                                 req->rq_svec->iov_base,
921                                 req->rq_svec->iov_len);
922
923         if (!xprt_bound(xprt))
924                 return -ENOTCONN;
925
926         if (!xprt_request_get_cong(xprt, req))
927                 return -EBADSLT;
928
929         req->rq_xtime = ktime_get();
930         status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
931
932         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
933                         xdr->len, status);
934
935         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
936         if (status == -EPERM)
937                 goto process_status;
938
939         if (status == -EAGAIN && sock_writeable(transport->inet))
940                 status = -ENOBUFS;
941
942         if (sent > 0 || status == 0) {
943                 req->rq_xmit_bytes_sent += sent;
944                 if (sent >= req->rq_slen)
945                         return 0;
946                 /* Still some bytes left; set up for a retry later. */
947                 status = -EAGAIN;
948         }
949
950 process_status:
951         switch (status) {
952         case -ENOTSOCK:
953                 status = -ENOTCONN;
954                 /* Should we call xs_close() here? */
955                 break;
956         case -EAGAIN:
957                 status = xs_nospace(req);
958                 break;
959         case -ENETUNREACH:
960         case -ENOBUFS:
961         case -EPIPE:
962         case -ECONNREFUSED:
963         case -EPERM:
964                 /* When the server has died, an ICMP port unreachable message
965                  * prompts ECONNREFUSED. */
966                 break;
967         default:
968                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
969                         -status);
970         }
971
972         return status;
973 }
974
975 /**
976  * xs_tcp_send_request - write an RPC request to a TCP socket
977  * @req: pointer to RPC request
978  *
979  * Return values:
980  *        0:    The request has been sent
981  *   EAGAIN:    The socket was blocked, please call again later to
982  *              complete the request
983  * ENOTCONN:    Caller needs to invoke connect logic then call again
984  *    other:    Some other error occurred, the request was not sent
985  *
986  * XXX: In the case of soft timeouts, should we eventually give up
987  *      if sendmsg is not able to make progress?
988  */
989 static int xs_tcp_send_request(struct rpc_rqst *req)
990 {
991         struct rpc_xprt *xprt = req->rq_xprt;
992         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
993         struct xdr_buf *xdr = &req->rq_snd_buf;
994         rpc_fraghdr rm = xs_stream_record_marker(xdr);
995         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
996         struct msghdr msg = {
997                 .msg_flags      = XS_SENDMSG_FLAGS,
998         };
999         bool vm_wait = false;
1000         unsigned int sent;
1001         int status;
1002
1003         /* Close the stream if the previous transmission was incomplete */
1004         if (xs_send_request_was_aborted(transport, req)) {
1005                 if (transport->sock != NULL)
1006                         kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1007                 return -ENOTCONN;
1008         }
1009
1010         xs_pktdump("packet data:",
1011                                 req->rq_svec->iov_base,
1012                                 req->rq_svec->iov_len);
1013
1014         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1015                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
1016
1017         /* Continue transmitting the packet/record. We must be careful
1018          * to cope with writespace callbacks arriving _after_ we have
1019          * called sendmsg(). */
1020         req->rq_xtime = ktime_get();
1021         while (1) {
1022                 status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1023                                            transport->xmit.offset, rm, &sent);
1024
1025                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1026                                 xdr->len - transport->xmit.offset, status);
1027
1028                 /* If we've sent the entire packet, immediately
1029                  * reset the count of bytes sent. */
1030                 transport->xmit.offset += sent;
1031                 req->rq_bytes_sent = transport->xmit.offset;
1032                 if (likely(req->rq_bytes_sent >= msglen)) {
1033                         req->rq_xmit_bytes_sent += transport->xmit.offset;
1034                         transport->xmit.offset = 0;
1035                         return 0;
1036                 }
1037
1038                 WARN_ON_ONCE(sent == 0 && status == 0);
1039
1040                 if (status == -EAGAIN ) {
1041                         /*
1042                          * Return EAGAIN if we're sure we're hitting the
1043                          * socket send buffer limits.
1044                          */
1045                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1046                                 break;
1047                         /*
1048                          * Did we hit a memory allocation failure?
1049                          */
1050                         if (sent == 0) {
1051                                 status = -ENOBUFS;
1052                                 if (vm_wait)
1053                                         break;
1054                                 /* Retry, knowing now that we're below the
1055                                  * socket send buffer limit
1056                                  */
1057                                 vm_wait = true;
1058                         }
1059                         continue;
1060                 }
1061                 if (status < 0)
1062                         break;
1063                 vm_wait = false;
1064         }
1065
1066         switch (status) {
1067         case -ENOTSOCK:
1068                 status = -ENOTCONN;
1069                 /* Should we call xs_close() here? */
1070                 break;
1071         case -EAGAIN:
1072                 status = xs_nospace(req);
1073                 break;
1074         case -ECONNRESET:
1075         case -ECONNREFUSED:
1076         case -ENOTCONN:
1077         case -EADDRINUSE:
1078         case -ENOBUFS:
1079         case -EPIPE:
1080                 break;
1081         default:
1082                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1083                         -status);
1084         }
1085
1086         return status;
1087 }
1088
1089 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1090 {
1091         transport->old_data_ready = sk->sk_data_ready;
1092         transport->old_state_change = sk->sk_state_change;
1093         transport->old_write_space = sk->sk_write_space;
1094         transport->old_error_report = sk->sk_error_report;
1095 }
1096
1097 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1098 {
1099         sk->sk_data_ready = transport->old_data_ready;
1100         sk->sk_state_change = transport->old_state_change;
1101         sk->sk_write_space = transport->old_write_space;
1102         sk->sk_error_report = transport->old_error_report;
1103 }
1104
1105 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1106 {
1107         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1108
1109         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1110         clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1111         clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1112         clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1113 }
1114
1115 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1116 {
1117         set_bit(nr, &transport->sock_state);
1118         queue_work(xprtiod_workqueue, &transport->error_worker);
1119 }
1120
1121 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1122 {
1123         smp_mb__before_atomic();
1124         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1125         clear_bit(XPRT_CLOSING, &xprt->state);
1126         xs_sock_reset_state_flags(xprt);
1127         smp_mb__after_atomic();
1128 }
1129
1130 /**
1131  * xs_error_report - callback to handle TCP socket state errors
1132  * @sk: socket
1133  *
1134  * Note: we don't call sock_error() since there may be a rpc_task
1135  * using the socket, and so we don't want to clear sk->sk_err.
1136  */
1137 static void xs_error_report(struct sock *sk)
1138 {
1139         struct sock_xprt *transport;
1140         struct rpc_xprt *xprt;
1141
1142         read_lock_bh(&sk->sk_callback_lock);
1143         if (!(xprt = xprt_from_sock(sk)))
1144                 goto out;
1145
1146         transport = container_of(xprt, struct sock_xprt, xprt);
1147         transport->xprt_err = -sk->sk_err;
1148         if (transport->xprt_err == 0)
1149                 goto out;
1150         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1151                         xprt, -transport->xprt_err);
1152         trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1153
1154         /* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1155         smp_mb__before_atomic();
1156         xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1157  out:
1158         read_unlock_bh(&sk->sk_callback_lock);
1159 }
1160
1161 static void xs_reset_transport(struct sock_xprt *transport)
1162 {
1163         struct socket *sock = transport->sock;
1164         struct sock *sk = transport->inet;
1165         struct rpc_xprt *xprt = &transport->xprt;
1166         struct file *filp = transport->file;
1167
1168         if (sk == NULL)
1169                 return;
1170
1171         if (atomic_read(&transport->xprt.swapper))
1172                 sk_clear_memalloc(sk);
1173
1174         kernel_sock_shutdown(sock, SHUT_RDWR);
1175
1176         mutex_lock(&transport->recv_mutex);
1177         write_lock_bh(&sk->sk_callback_lock);
1178         transport->inet = NULL;
1179         transport->sock = NULL;
1180         transport->file = NULL;
1181
1182         sk->sk_user_data = NULL;
1183
1184         xs_restore_old_callbacks(transport, sk);
1185         xprt_clear_connected(xprt);
1186         write_unlock_bh(&sk->sk_callback_lock);
1187         xs_sock_reset_connection_flags(xprt);
1188         /* Reset stream record info */
1189         xs_stream_reset_connect(transport);
1190         mutex_unlock(&transport->recv_mutex);
1191
1192         trace_rpc_socket_close(xprt, sock);
1193         fput(filp);
1194
1195         xprt_disconnect_done(xprt);
1196 }
1197
1198 /**
1199  * xs_close - close a socket
1200  * @xprt: transport
1201  *
1202  * This is used when all requests are complete; ie, no DRC state remains
1203  * on the server we want to save.
1204  *
1205  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1206  * xs_reset_transport() zeroing the socket from underneath a writer.
1207  */
1208 static void xs_close(struct rpc_xprt *xprt)
1209 {
1210         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1211
1212         dprintk("RPC:       xs_close xprt %p\n", xprt);
1213
1214         xs_reset_transport(transport);
1215         xprt->reestablish_timeout = 0;
1216 }
1217
1218 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1219 {
1220         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1221                 xprt);
1222         xprt_disconnect_done(xprt);
1223 }
1224
1225 static void xs_xprt_free(struct rpc_xprt *xprt)
1226 {
1227         xs_free_peer_addresses(xprt);
1228         xprt_free(xprt);
1229 }
1230
1231 /**
1232  * xs_destroy - prepare to shutdown a transport
1233  * @xprt: doomed transport
1234  *
1235  */
1236 static void xs_destroy(struct rpc_xprt *xprt)
1237 {
1238         struct sock_xprt *transport = container_of(xprt,
1239                         struct sock_xprt, xprt);
1240         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1241
1242         cancel_delayed_work_sync(&transport->connect_worker);
1243         xs_close(xprt);
1244         cancel_work_sync(&transport->recv_worker);
1245         cancel_work_sync(&transport->error_worker);
1246         xs_xprt_free(xprt);
1247         module_put(THIS_MODULE);
1248 }
1249
1250 /**
1251  * xs_udp_data_read_skb - receive callback for UDP sockets
1252  * @xprt: transport
1253  * @sk: socket
1254  * @skb: skbuff
1255  *
1256  */
1257 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1258                 struct sock *sk,
1259                 struct sk_buff *skb)
1260 {
1261         struct rpc_task *task;
1262         struct rpc_rqst *rovr;
1263         int repsize, copied;
1264         u32 _xid;
1265         __be32 *xp;
1266
1267         repsize = skb->len;
1268         if (repsize < 4) {
1269                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1270                 return;
1271         }
1272
1273         /* Copy the XID from the skb... */
1274         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1275         if (xp == NULL)
1276                 return;
1277
1278         /* Look up and lock the request corresponding to the given XID */
1279         spin_lock(&xprt->queue_lock);
1280         rovr = xprt_lookup_rqst(xprt, *xp);
1281         if (!rovr)
1282                 goto out_unlock;
1283         xprt_pin_rqst(rovr);
1284         xprt_update_rtt(rovr->rq_task);
1285         spin_unlock(&xprt->queue_lock);
1286         task = rovr->rq_task;
1287
1288         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1289                 copied = repsize;
1290
1291         /* Suck it into the iovec, verify checksum if not done by hw. */
1292         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1293                 spin_lock(&xprt->queue_lock);
1294                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1295                 goto out_unpin;
1296         }
1297
1298
1299         spin_lock(&xprt->transport_lock);
1300         xprt_adjust_cwnd(xprt, task, copied);
1301         spin_unlock(&xprt->transport_lock);
1302         spin_lock(&xprt->queue_lock);
1303         xprt_complete_rqst(task, copied);
1304         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1305 out_unpin:
1306         xprt_unpin_rqst(rovr);
1307  out_unlock:
1308         spin_unlock(&xprt->queue_lock);
1309 }
1310
1311 static void xs_udp_data_receive(struct sock_xprt *transport)
1312 {
1313         struct sk_buff *skb;
1314         struct sock *sk;
1315         int err;
1316
1317         mutex_lock(&transport->recv_mutex);
1318         sk = transport->inet;
1319         if (sk == NULL)
1320                 goto out;
1321         for (;;) {
1322                 skb = skb_recv_udp(sk, 0, 1, &err);
1323                 if (skb == NULL)
1324                         break;
1325                 xs_udp_data_read_skb(&transport->xprt, sk, skb);
1326                 consume_skb(skb);
1327                 cond_resched();
1328         }
1329         xs_poll_check_readable(transport);
1330 out:
1331         mutex_unlock(&transport->recv_mutex);
1332 }
1333
1334 static void xs_udp_data_receive_workfn(struct work_struct *work)
1335 {
1336         struct sock_xprt *transport =
1337                 container_of(work, struct sock_xprt, recv_worker);
1338         unsigned int pflags = memalloc_nofs_save();
1339
1340         xs_udp_data_receive(transport);
1341         memalloc_nofs_restore(pflags);
1342 }
1343
1344 /**
1345  * xs_data_ready - "data ready" callback for UDP sockets
1346  * @sk: socket with data to read
1347  *
1348  */
1349 static void xs_data_ready(struct sock *sk)
1350 {
1351         struct rpc_xprt *xprt;
1352
1353         read_lock_bh(&sk->sk_callback_lock);
1354         dprintk("RPC:       xs_data_ready...\n");
1355         xprt = xprt_from_sock(sk);
1356         if (xprt != NULL) {
1357                 struct sock_xprt *transport = container_of(xprt,
1358                                 struct sock_xprt, xprt);
1359                 transport->old_data_ready(sk);
1360                 /* Any data means we had a useful conversation, so
1361                  * then we don't need to delay the next reconnect
1362                  */
1363                 if (xprt->reestablish_timeout)
1364                         xprt->reestablish_timeout = 0;
1365                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1366                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1367         }
1368         read_unlock_bh(&sk->sk_callback_lock);
1369 }
1370
1371 /*
1372  * Helper function to force a TCP close if the server is sending
1373  * junk and/or it has put us in CLOSE_WAIT
1374  */
1375 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1376 {
1377         xprt_force_disconnect(xprt);
1378 }
1379
1380 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1381 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1382 {
1383         return PAGE_SIZE;
1384 }
1385 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1386
1387 /**
1388  * xs_tcp_state_change - callback to handle TCP socket state changes
1389  * @sk: socket whose state has changed
1390  *
1391  */
1392 static void xs_tcp_state_change(struct sock *sk)
1393 {
1394         struct rpc_xprt *xprt;
1395         struct sock_xprt *transport;
1396
1397         read_lock_bh(&sk->sk_callback_lock);
1398         if (!(xprt = xprt_from_sock(sk)))
1399                 goto out;
1400         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1401         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1402                         sk->sk_state, xprt_connected(xprt),
1403                         sock_flag(sk, SOCK_DEAD),
1404                         sock_flag(sk, SOCK_ZAPPED),
1405                         sk->sk_shutdown);
1406
1407         transport = container_of(xprt, struct sock_xprt, xprt);
1408         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1409         switch (sk->sk_state) {
1410         case TCP_ESTABLISHED:
1411                 if (!xprt_test_and_set_connected(xprt)) {
1412                         xprt->connect_cookie++;
1413                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1414                         xprt_clear_connecting(xprt);
1415
1416                         xprt->stat.connect_count++;
1417                         xprt->stat.connect_time += (long)jiffies -
1418                                                    xprt->stat.connect_start;
1419                         xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1420                 }
1421                 break;
1422         case TCP_FIN_WAIT1:
1423                 /* The client initiated a shutdown of the socket */
1424                 xprt->connect_cookie++;
1425                 xprt->reestablish_timeout = 0;
1426                 set_bit(XPRT_CLOSING, &xprt->state);
1427                 smp_mb__before_atomic();
1428                 clear_bit(XPRT_CONNECTED, &xprt->state);
1429                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1430                 smp_mb__after_atomic();
1431                 break;
1432         case TCP_CLOSE_WAIT:
1433                 /* The server initiated a shutdown of the socket */
1434                 xprt->connect_cookie++;
1435                 clear_bit(XPRT_CONNECTED, &xprt->state);
1436                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1437                 fallthrough;
1438         case TCP_CLOSING:
1439                 /*
1440                  * If the server closed down the connection, make sure that
1441                  * we back off before reconnecting
1442                  */
1443                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1444                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1445                 break;
1446         case TCP_LAST_ACK:
1447                 set_bit(XPRT_CLOSING, &xprt->state);
1448                 smp_mb__before_atomic();
1449                 clear_bit(XPRT_CONNECTED, &xprt->state);
1450                 smp_mb__after_atomic();
1451                 break;
1452         case TCP_CLOSE:
1453                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1454                                         &transport->sock_state))
1455                         xprt_clear_connecting(xprt);
1456                 clear_bit(XPRT_CLOSING, &xprt->state);
1457                 /* Trigger the socket release */
1458                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1459         }
1460  out:
1461         read_unlock_bh(&sk->sk_callback_lock);
1462 }
1463
1464 static void xs_write_space(struct sock *sk)
1465 {
1466         struct socket_wq *wq;
1467         struct sock_xprt *transport;
1468         struct rpc_xprt *xprt;
1469
1470         if (!sk->sk_socket)
1471                 return;
1472         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1473
1474         if (unlikely(!(xprt = xprt_from_sock(sk))))
1475                 return;
1476         transport = container_of(xprt, struct sock_xprt, xprt);
1477         rcu_read_lock();
1478         wq = rcu_dereference(sk->sk_wq);
1479         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1480                 goto out;
1481
1482         xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1483         sk->sk_write_pending--;
1484 out:
1485         rcu_read_unlock();
1486 }
1487
1488 /**
1489  * xs_udp_write_space - callback invoked when socket buffer space
1490  *                             becomes available
1491  * @sk: socket whose state has changed
1492  *
1493  * Called when more output buffer space is available for this socket.
1494  * We try not to wake our writers until they can make "significant"
1495  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1496  * with a bunch of small requests.
1497  */
1498 static void xs_udp_write_space(struct sock *sk)
1499 {
1500         read_lock_bh(&sk->sk_callback_lock);
1501
1502         /* from net/core/sock.c:sock_def_write_space */
1503         if (sock_writeable(sk))
1504                 xs_write_space(sk);
1505
1506         read_unlock_bh(&sk->sk_callback_lock);
1507 }
1508
1509 /**
1510  * xs_tcp_write_space - callback invoked when socket buffer space
1511  *                             becomes available
1512  * @sk: socket whose state has changed
1513  *
1514  * Called when more output buffer space is available for this socket.
1515  * We try not to wake our writers until they can make "significant"
1516  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1517  * with a bunch of small requests.
1518  */
1519 static void xs_tcp_write_space(struct sock *sk)
1520 {
1521         read_lock_bh(&sk->sk_callback_lock);
1522
1523         /* from net/core/stream.c:sk_stream_write_space */
1524         if (sk_stream_is_writeable(sk))
1525                 xs_write_space(sk);
1526
1527         read_unlock_bh(&sk->sk_callback_lock);
1528 }
1529
1530 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1531 {
1532         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1533         struct sock *sk = transport->inet;
1534
1535         if (transport->rcvsize) {
1536                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1537                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1538         }
1539         if (transport->sndsize) {
1540                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1541                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1542                 sk->sk_write_space(sk);
1543         }
1544 }
1545
1546 /**
1547  * xs_udp_set_buffer_size - set send and receive limits
1548  * @xprt: generic transport
1549  * @sndsize: requested size of send buffer, in bytes
1550  * @rcvsize: requested size of receive buffer, in bytes
1551  *
1552  * Set socket send and receive buffer size limits.
1553  */
1554 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1555 {
1556         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1557
1558         transport->sndsize = 0;
1559         if (sndsize)
1560                 transport->sndsize = sndsize + 1024;
1561         transport->rcvsize = 0;
1562         if (rcvsize)
1563                 transport->rcvsize = rcvsize + 1024;
1564
1565         xs_udp_do_set_buffer_size(xprt);
1566 }
1567
1568 /**
1569  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1570  * @xprt: controlling transport
1571  * @task: task that timed out
1572  *
1573  * Adjust the congestion window after a retransmit timeout has occurred.
1574  */
1575 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1576 {
1577         spin_lock(&xprt->transport_lock);
1578         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1579         spin_unlock(&xprt->transport_lock);
1580 }
1581
1582 static int xs_get_random_port(void)
1583 {
1584         unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1585         unsigned short range;
1586         unsigned short rand;
1587
1588         if (max < min)
1589                 return -EADDRINUSE;
1590         range = max - min + 1;
1591         rand = (unsigned short) prandom_u32() % range;
1592         return rand + min;
1593 }
1594
1595 static unsigned short xs_sock_getport(struct socket *sock)
1596 {
1597         struct sockaddr_storage buf;
1598         unsigned short port = 0;
1599
1600         if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1601                 goto out;
1602         switch (buf.ss_family) {
1603         case AF_INET6:
1604                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1605                 break;
1606         case AF_INET:
1607                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1608         }
1609 out:
1610         return port;
1611 }
1612
1613 /**
1614  * xs_set_port - reset the port number in the remote endpoint address
1615  * @xprt: generic transport
1616  * @port: new port number
1617  *
1618  */
1619 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1620 {
1621         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1622
1623         rpc_set_port(xs_addr(xprt), port);
1624         xs_update_peer_port(xprt);
1625 }
1626
1627 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1628 {
1629         if (transport->srcport == 0 && transport->xprt.reuseport)
1630                 transport->srcport = xs_sock_getport(sock);
1631 }
1632
1633 static int xs_get_srcport(struct sock_xprt *transport)
1634 {
1635         int port = transport->srcport;
1636
1637         if (port == 0 && transport->xprt.resvport)
1638                 port = xs_get_random_port();
1639         return port;
1640 }
1641
1642 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1643 {
1644         if (transport->srcport != 0)
1645                 transport->srcport = 0;
1646         if (!transport->xprt.resvport)
1647                 return 0;
1648         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1649                 return xprt_max_resvport;
1650         return --port;
1651 }
1652 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1653 {
1654         struct sockaddr_storage myaddr;
1655         int err, nloop = 0;
1656         int port = xs_get_srcport(transport);
1657         unsigned short last;
1658
1659         /*
1660          * If we are asking for any ephemeral port (i.e. port == 0 &&
1661          * transport->xprt.resvport == 0), don't bind.  Let the local
1662          * port selection happen implicitly when the socket is used
1663          * (for example at connect time).
1664          *
1665          * This ensures that we can continue to establish TCP
1666          * connections even when all local ephemeral ports are already
1667          * a part of some TCP connection.  This makes no difference
1668          * for UDP sockets, but also doesn't harm them.
1669          *
1670          * If we're asking for any reserved port (i.e. port == 0 &&
1671          * transport->xprt.resvport == 1) xs_get_srcport above will
1672          * ensure that port is non-zero and we will bind as needed.
1673          */
1674         if (port <= 0)
1675                 return port;
1676
1677         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1678         do {
1679                 rpc_set_port((struct sockaddr *)&myaddr, port);
1680                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1681                                 transport->xprt.addrlen);
1682                 if (err == 0) {
1683                         transport->srcport = port;
1684                         break;
1685                 }
1686                 last = port;
1687                 port = xs_next_srcport(transport, port);
1688                 if (port > last)
1689                         nloop++;
1690         } while (err == -EADDRINUSE && nloop != 2);
1691
1692         if (myaddr.ss_family == AF_INET)
1693                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1694                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1695                                 port, err ? "failed" : "ok", err);
1696         else
1697                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1698                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1699                                 port, err ? "failed" : "ok", err);
1700         return err;
1701 }
1702
1703 /*
1704  * We don't support autobind on AF_LOCAL sockets
1705  */
1706 static void xs_local_rpcbind(struct rpc_task *task)
1707 {
1708         xprt_set_bound(task->tk_xprt);
1709 }
1710
1711 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1712 {
1713 }
1714
1715 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1716 static struct lock_class_key xs_key[2];
1717 static struct lock_class_key xs_slock_key[2];
1718
1719 static inline void xs_reclassify_socketu(struct socket *sock)
1720 {
1721         struct sock *sk = sock->sk;
1722
1723         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1724                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1725 }
1726
1727 static inline void xs_reclassify_socket4(struct socket *sock)
1728 {
1729         struct sock *sk = sock->sk;
1730
1731         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1732                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1733 }
1734
1735 static inline void xs_reclassify_socket6(struct socket *sock)
1736 {
1737         struct sock *sk = sock->sk;
1738
1739         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1740                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1741 }
1742
1743 static inline void xs_reclassify_socket(int family, struct socket *sock)
1744 {
1745         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1746                 return;
1747
1748         switch (family) {
1749         case AF_LOCAL:
1750                 xs_reclassify_socketu(sock);
1751                 break;
1752         case AF_INET:
1753                 xs_reclassify_socket4(sock);
1754                 break;
1755         case AF_INET6:
1756                 xs_reclassify_socket6(sock);
1757                 break;
1758         }
1759 }
1760 #else
1761 static inline void xs_reclassify_socket(int family, struct socket *sock)
1762 {
1763 }
1764 #endif
1765
1766 static void xs_dummy_setup_socket(struct work_struct *work)
1767 {
1768 }
1769
1770 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1771                 struct sock_xprt *transport, int family, int type,
1772                 int protocol, bool reuseport)
1773 {
1774         struct file *filp;
1775         struct socket *sock;
1776         int err;
1777
1778         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1779         if (err < 0) {
1780                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1781                                 protocol, -err);
1782                 goto out;
1783         }
1784         xs_reclassify_socket(family, sock);
1785
1786         if (reuseport)
1787                 sock_set_reuseport(sock->sk);
1788
1789         err = xs_bind(transport, sock);
1790         if (err) {
1791                 sock_release(sock);
1792                 goto out;
1793         }
1794
1795         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1796         if (IS_ERR(filp))
1797                 return ERR_CAST(filp);
1798         transport->file = filp;
1799
1800         return sock;
1801 out:
1802         return ERR_PTR(err);
1803 }
1804
1805 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1806                                       struct socket *sock)
1807 {
1808         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1809                                                                         xprt);
1810
1811         if (!transport->inet) {
1812                 struct sock *sk = sock->sk;
1813
1814                 write_lock_bh(&sk->sk_callback_lock);
1815
1816                 xs_save_old_callbacks(transport, sk);
1817
1818                 sk->sk_user_data = xprt;
1819                 sk->sk_data_ready = xs_data_ready;
1820                 sk->sk_write_space = xs_udp_write_space;
1821                 sock_set_flag(sk, SOCK_FASYNC);
1822                 sk->sk_error_report = xs_error_report;
1823
1824                 xprt_clear_connected(xprt);
1825
1826                 /* Reset to new socket */
1827                 transport->sock = sock;
1828                 transport->inet = sk;
1829
1830                 write_unlock_bh(&sk->sk_callback_lock);
1831         }
1832
1833         xs_stream_start_connect(transport);
1834
1835         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1836 }
1837
1838 /**
1839  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1840  * @transport: socket transport to connect
1841  */
1842 static int xs_local_setup_socket(struct sock_xprt *transport)
1843 {
1844         struct rpc_xprt *xprt = &transport->xprt;
1845         struct file *filp;
1846         struct socket *sock;
1847         int status;
1848
1849         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1850                                         SOCK_STREAM, 0, &sock, 1);
1851         if (status < 0) {
1852                 dprintk("RPC:       can't create AF_LOCAL "
1853                         "transport socket (%d).\n", -status);
1854                 goto out;
1855         }
1856         xs_reclassify_socket(AF_LOCAL, sock);
1857
1858         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1859         if (IS_ERR(filp)) {
1860                 status = PTR_ERR(filp);
1861                 goto out;
1862         }
1863         transport->file = filp;
1864
1865         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1866                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1867
1868         status = xs_local_finish_connecting(xprt, sock);
1869         trace_rpc_socket_connect(xprt, sock, status);
1870         switch (status) {
1871         case 0:
1872                 dprintk("RPC:       xprt %p connected to %s\n",
1873                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1874                 xprt->stat.connect_count++;
1875                 xprt->stat.connect_time += (long)jiffies -
1876                                            xprt->stat.connect_start;
1877                 xprt_set_connected(xprt);
1878                 break;
1879         case -ENOBUFS:
1880                 break;
1881         case -ENOENT:
1882                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1883                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1884                 break;
1885         case -ECONNREFUSED:
1886                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1887                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1888                 break;
1889         default:
1890                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1891                                 __func__, -status,
1892                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1893         }
1894
1895 out:
1896         xprt_clear_connecting(xprt);
1897         xprt_wake_pending_tasks(xprt, status);
1898         return status;
1899 }
1900
1901 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1902 {
1903         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1904         int ret;
1905
1906          if (RPC_IS_ASYNC(task)) {
1907                 /*
1908                  * We want the AF_LOCAL connect to be resolved in the
1909                  * filesystem namespace of the process making the rpc
1910                  * call.  Thus we connect synchronously.
1911                  *
1912                  * If we want to support asynchronous AF_LOCAL calls,
1913                  * we'll need to figure out how to pass a namespace to
1914                  * connect.
1915                  */
1916                 task->tk_rpc_status = -ENOTCONN;
1917                 rpc_exit(task, -ENOTCONN);
1918                 return;
1919         }
1920         ret = xs_local_setup_socket(transport);
1921         if (ret && !RPC_IS_SOFTCONN(task))
1922                 msleep_interruptible(15000);
1923 }
1924
1925 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1926 /*
1927  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1928  * know that we have exclusive access to the socket), to guard against
1929  * races with xs_reset_transport.
1930  */
1931 static void xs_set_memalloc(struct rpc_xprt *xprt)
1932 {
1933         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1934                         xprt);
1935
1936         /*
1937          * If there's no sock, then we have nothing to set. The
1938          * reconnecting process will get it for us.
1939          */
1940         if (!transport->inet)
1941                 return;
1942         if (atomic_read(&xprt->swapper))
1943                 sk_set_memalloc(transport->inet);
1944 }
1945
1946 /**
1947  * xs_enable_swap - Tag this transport as being used for swap.
1948  * @xprt: transport to tag
1949  *
1950  * Take a reference to this transport on behalf of the rpc_clnt, and
1951  * optionally mark it for swapping if it wasn't already.
1952  */
1953 static int
1954 xs_enable_swap(struct rpc_xprt *xprt)
1955 {
1956         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1957
1958         if (atomic_inc_return(&xprt->swapper) != 1)
1959                 return 0;
1960         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1961                 return -ERESTARTSYS;
1962         if (xs->inet)
1963                 sk_set_memalloc(xs->inet);
1964         xprt_release_xprt(xprt, NULL);
1965         return 0;
1966 }
1967
1968 /**
1969  * xs_disable_swap - Untag this transport as being used for swap.
1970  * @xprt: transport to tag
1971  *
1972  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1973  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1974  */
1975 static void
1976 xs_disable_swap(struct rpc_xprt *xprt)
1977 {
1978         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1979
1980         if (!atomic_dec_and_test(&xprt->swapper))
1981                 return;
1982         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1983                 return;
1984         if (xs->inet)
1985                 sk_clear_memalloc(xs->inet);
1986         xprt_release_xprt(xprt, NULL);
1987 }
1988 #else
1989 static void xs_set_memalloc(struct rpc_xprt *xprt)
1990 {
1991 }
1992
1993 static int
1994 xs_enable_swap(struct rpc_xprt *xprt)
1995 {
1996         return -EINVAL;
1997 }
1998
1999 static void
2000 xs_disable_swap(struct rpc_xprt *xprt)
2001 {
2002 }
2003 #endif
2004
2005 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2006 {
2007         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2008
2009         if (!transport->inet) {
2010                 struct sock *sk = sock->sk;
2011
2012                 write_lock_bh(&sk->sk_callback_lock);
2013
2014                 xs_save_old_callbacks(transport, sk);
2015
2016                 sk->sk_user_data = xprt;
2017                 sk->sk_data_ready = xs_data_ready;
2018                 sk->sk_write_space = xs_udp_write_space;
2019                 sock_set_flag(sk, SOCK_FASYNC);
2020
2021                 xprt_set_connected(xprt);
2022
2023                 /* Reset to new socket */
2024                 transport->sock = sock;
2025                 transport->inet = sk;
2026
2027                 xs_set_memalloc(xprt);
2028
2029                 write_unlock_bh(&sk->sk_callback_lock);
2030         }
2031         xs_udp_do_set_buffer_size(xprt);
2032
2033         xprt->stat.connect_start = jiffies;
2034 }
2035
2036 static void xs_udp_setup_socket(struct work_struct *work)
2037 {
2038         struct sock_xprt *transport =
2039                 container_of(work, struct sock_xprt, connect_worker.work);
2040         struct rpc_xprt *xprt = &transport->xprt;
2041         struct socket *sock;
2042         int status = -EIO;
2043
2044         sock = xs_create_sock(xprt, transport,
2045                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2046                         IPPROTO_UDP, false);
2047         if (IS_ERR(sock))
2048                 goto out;
2049
2050         dprintk("RPC:       worker connecting xprt %p via %s to "
2051                                 "%s (port %s)\n", xprt,
2052                         xprt->address_strings[RPC_DISPLAY_PROTO],
2053                         xprt->address_strings[RPC_DISPLAY_ADDR],
2054                         xprt->address_strings[RPC_DISPLAY_PORT]);
2055
2056         xs_udp_finish_connecting(xprt, sock);
2057         trace_rpc_socket_connect(xprt, sock, 0);
2058         status = 0;
2059 out:
2060         xprt_clear_connecting(xprt);
2061         xprt_unlock_connect(xprt, transport);
2062         xprt_wake_pending_tasks(xprt, status);
2063 }
2064
2065 /**
2066  * xs_tcp_shutdown - gracefully shut down a TCP socket
2067  * @xprt: transport
2068  *
2069  * Initiates a graceful shutdown of the TCP socket by calling the
2070  * equivalent of shutdown(SHUT_RDWR);
2071  */
2072 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2073 {
2074         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2075         struct socket *sock = transport->sock;
2076         int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2077
2078         if (sock == NULL)
2079                 return;
2080         switch (skst) {
2081         default:
2082                 kernel_sock_shutdown(sock, SHUT_RDWR);
2083                 trace_rpc_socket_shutdown(xprt, sock);
2084                 break;
2085         case TCP_CLOSE:
2086         case TCP_TIME_WAIT:
2087                 xs_reset_transport(transport);
2088         }
2089 }
2090
2091 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2092                 struct socket *sock)
2093 {
2094         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2095         unsigned int keepidle;
2096         unsigned int keepcnt;
2097         unsigned int timeo;
2098
2099         spin_lock(&xprt->transport_lock);
2100         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2101         keepcnt = xprt->timeout->to_retries + 1;
2102         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2103                 (xprt->timeout->to_retries + 1);
2104         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2105         spin_unlock(&xprt->transport_lock);
2106
2107         /* TCP Keepalive options */
2108         sock_set_keepalive(sock->sk);
2109         tcp_sock_set_keepidle(sock->sk, keepidle);
2110         tcp_sock_set_keepintvl(sock->sk, keepidle);
2111         tcp_sock_set_keepcnt(sock->sk, keepcnt);
2112
2113         /* TCP user timeout (see RFC5482) */
2114         tcp_sock_set_user_timeout(sock->sk, timeo);
2115 }
2116
2117 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2118                 unsigned long connect_timeout,
2119                 unsigned long reconnect_timeout)
2120 {
2121         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2122         struct rpc_timeout to;
2123         unsigned long initval;
2124
2125         spin_lock(&xprt->transport_lock);
2126         if (reconnect_timeout < xprt->max_reconnect_timeout)
2127                 xprt->max_reconnect_timeout = reconnect_timeout;
2128         if (connect_timeout < xprt->connect_timeout) {
2129                 memcpy(&to, xprt->timeout, sizeof(to));
2130                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2131                 /* Arbitrary lower limit */
2132                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2133                         initval = XS_TCP_INIT_REEST_TO << 1;
2134                 to.to_initval = initval;
2135                 to.to_maxval = initval;
2136                 memcpy(&transport->tcp_timeout, &to,
2137                                 sizeof(transport->tcp_timeout));
2138                 xprt->timeout = &transport->tcp_timeout;
2139                 xprt->connect_timeout = connect_timeout;
2140         }
2141         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2142         spin_unlock(&xprt->transport_lock);
2143 }
2144
2145 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2146 {
2147         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2148         int ret = -ENOTCONN;
2149
2150         if (!transport->inet) {
2151                 struct sock *sk = sock->sk;
2152
2153                 /* Avoid temporary address, they are bad for long-lived
2154                  * connections such as NFS mounts.
2155                  * RFC4941, section 3.6 suggests that:
2156                  *    Individual applications, which have specific
2157                  *    knowledge about the normal duration of connections,
2158                  *    MAY override this as appropriate.
2159                  */
2160                 if (xs_addr(xprt)->sa_family == PF_INET6) {
2161                         ip6_sock_set_addr_preferences(sk,
2162                                 IPV6_PREFER_SRC_PUBLIC);
2163                 }
2164
2165                 xs_tcp_set_socket_timeouts(xprt, sock);
2166
2167                 write_lock_bh(&sk->sk_callback_lock);
2168
2169                 xs_save_old_callbacks(transport, sk);
2170
2171                 sk->sk_user_data = xprt;
2172                 sk->sk_data_ready = xs_data_ready;
2173                 sk->sk_state_change = xs_tcp_state_change;
2174                 sk->sk_write_space = xs_tcp_write_space;
2175                 sock_set_flag(sk, SOCK_FASYNC);
2176                 sk->sk_error_report = xs_error_report;
2177
2178                 /* socket options */
2179                 sock_reset_flag(sk, SOCK_LINGER);
2180                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2181
2182                 xprt_clear_connected(xprt);
2183
2184                 /* Reset to new socket */
2185                 transport->sock = sock;
2186                 transport->inet = sk;
2187
2188                 write_unlock_bh(&sk->sk_callback_lock);
2189         }
2190
2191         if (!xprt_bound(xprt))
2192                 goto out;
2193
2194         xs_set_memalloc(xprt);
2195
2196         xs_stream_start_connect(transport);
2197
2198         /* Tell the socket layer to start connecting... */
2199         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2200         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2201         switch (ret) {
2202         case 0:
2203                 xs_set_srcport(transport, sock);
2204                 fallthrough;
2205         case -EINPROGRESS:
2206                 /* SYN_SENT! */
2207                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2208                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2209                 break;
2210         case -EADDRNOTAVAIL:
2211                 /* Source port number is unavailable. Try a new one! */
2212                 transport->srcport = 0;
2213         }
2214 out:
2215         return ret;
2216 }
2217
2218 /**
2219  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2220  * @work: queued work item
2221  *
2222  * Invoked by a work queue tasklet.
2223  */
2224 static void xs_tcp_setup_socket(struct work_struct *work)
2225 {
2226         struct sock_xprt *transport =
2227                 container_of(work, struct sock_xprt, connect_worker.work);
2228         struct socket *sock = transport->sock;
2229         struct rpc_xprt *xprt = &transport->xprt;
2230         int status = -EIO;
2231
2232         if (!sock) {
2233                 sock = xs_create_sock(xprt, transport,
2234                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2235                                 IPPROTO_TCP, true);
2236                 if (IS_ERR(sock)) {
2237                         status = PTR_ERR(sock);
2238                         goto out;
2239                 }
2240         }
2241
2242         dprintk("RPC:       worker connecting xprt %p via %s to "
2243                                 "%s (port %s)\n", xprt,
2244                         xprt->address_strings[RPC_DISPLAY_PROTO],
2245                         xprt->address_strings[RPC_DISPLAY_ADDR],
2246                         xprt->address_strings[RPC_DISPLAY_PORT]);
2247
2248         status = xs_tcp_finish_connecting(xprt, sock);
2249         trace_rpc_socket_connect(xprt, sock, status);
2250         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2251                         xprt, -status, xprt_connected(xprt),
2252                         sock->sk->sk_state);
2253         switch (status) {
2254         default:
2255                 printk("%s: connect returned unhandled error %d\n",
2256                         __func__, status);
2257                 fallthrough;
2258         case -EADDRNOTAVAIL:
2259                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2260                  * and retry
2261                  */
2262                 xs_tcp_force_close(xprt);
2263                 break;
2264         case 0:
2265         case -EINPROGRESS:
2266         case -EALREADY:
2267                 xprt_unlock_connect(xprt, transport);
2268                 return;
2269         case -EINVAL:
2270                 /* Happens, for instance, if the user specified a link
2271                  * local IPv6 address without a scope-id.
2272                  */
2273         case -ECONNREFUSED:
2274         case -ECONNRESET:
2275         case -ENETDOWN:
2276         case -ENETUNREACH:
2277         case -EHOSTUNREACH:
2278         case -EADDRINUSE:
2279         case -ENOBUFS:
2280                 /* xs_tcp_force_close() wakes tasks with a fixed error code.
2281                  * We need to wake them first to ensure the correct error code.
2282                  */
2283                 xprt_wake_pending_tasks(xprt, status);
2284                 xs_tcp_force_close(xprt);
2285                 goto out;
2286         }
2287         status = -EAGAIN;
2288 out:
2289         xprt_clear_connecting(xprt);
2290         xprt_unlock_connect(xprt, transport);
2291         xprt_wake_pending_tasks(xprt, status);
2292 }
2293
2294 /**
2295  * xs_connect - connect a socket to a remote endpoint
2296  * @xprt: pointer to transport structure
2297  * @task: address of RPC task that manages state of connect request
2298  *
2299  * TCP: If the remote end dropped the connection, delay reconnecting.
2300  *
2301  * UDP socket connects are synchronous, but we use a work queue anyway
2302  * to guarantee that even unprivileged user processes can set up a
2303  * socket on a privileged port.
2304  *
2305  * If a UDP socket connect fails, the delay behavior here prevents
2306  * retry floods (hard mounts).
2307  */
2308 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2309 {
2310         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2311         unsigned long delay = 0;
2312
2313         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2314
2315         if (transport->sock != NULL) {
2316                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2317                                 "seconds\n",
2318                                 xprt, xprt->reestablish_timeout / HZ);
2319
2320                 /* Start by resetting any existing state */
2321                 xs_reset_transport(transport);
2322
2323                 delay = xprt_reconnect_delay(xprt);
2324                 xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2325
2326         } else
2327                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2328
2329         queue_delayed_work(xprtiod_workqueue,
2330                         &transport->connect_worker,
2331                         delay);
2332 }
2333
2334 static void xs_wake_disconnect(struct sock_xprt *transport)
2335 {
2336         if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2337                 xs_tcp_force_close(&transport->xprt);
2338 }
2339
2340 static void xs_wake_write(struct sock_xprt *transport)
2341 {
2342         if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2343                 xprt_write_space(&transport->xprt);
2344 }
2345
2346 static void xs_wake_error(struct sock_xprt *transport)
2347 {
2348         int sockerr;
2349
2350         if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2351                 return;
2352         mutex_lock(&transport->recv_mutex);
2353         if (transport->sock == NULL)
2354                 goto out;
2355         if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2356                 goto out;
2357         sockerr = xchg(&transport->xprt_err, 0);
2358         if (sockerr < 0)
2359                 xprt_wake_pending_tasks(&transport->xprt, sockerr);
2360 out:
2361         mutex_unlock(&transport->recv_mutex);
2362 }
2363
2364 static void xs_wake_pending(struct sock_xprt *transport)
2365 {
2366         if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2367                 xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2368 }
2369
2370 static void xs_error_handle(struct work_struct *work)
2371 {
2372         struct sock_xprt *transport = container_of(work,
2373                         struct sock_xprt, error_worker);
2374
2375         xs_wake_disconnect(transport);
2376         xs_wake_write(transport);
2377         xs_wake_error(transport);
2378         xs_wake_pending(transport);
2379 }
2380
2381 /**
2382  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2383  * @xprt: rpc_xprt struct containing statistics
2384  * @seq: output file
2385  *
2386  */
2387 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2388 {
2389         long idle_time = 0;
2390
2391         if (xprt_connected(xprt))
2392                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2393
2394         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2395                         "%llu %llu %lu %llu %llu\n",
2396                         xprt->stat.bind_count,
2397                         xprt->stat.connect_count,
2398                         xprt->stat.connect_time / HZ,
2399                         idle_time,
2400                         xprt->stat.sends,
2401                         xprt->stat.recvs,
2402                         xprt->stat.bad_xids,
2403                         xprt->stat.req_u,
2404                         xprt->stat.bklog_u,
2405                         xprt->stat.max_slots,
2406                         xprt->stat.sending_u,
2407                         xprt->stat.pending_u);
2408 }
2409
2410 /**
2411  * xs_udp_print_stats - display UDP socket-specific stats
2412  * @xprt: rpc_xprt struct containing statistics
2413  * @seq: output file
2414  *
2415  */
2416 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2417 {
2418         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2419
2420         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2421                         "%lu %llu %llu\n",
2422                         transport->srcport,
2423                         xprt->stat.bind_count,
2424                         xprt->stat.sends,
2425                         xprt->stat.recvs,
2426                         xprt->stat.bad_xids,
2427                         xprt->stat.req_u,
2428                         xprt->stat.bklog_u,
2429                         xprt->stat.max_slots,
2430                         xprt->stat.sending_u,
2431                         xprt->stat.pending_u);
2432 }
2433
2434 /**
2435  * xs_tcp_print_stats - display TCP socket-specific stats
2436  * @xprt: rpc_xprt struct containing statistics
2437  * @seq: output file
2438  *
2439  */
2440 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2441 {
2442         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2443         long idle_time = 0;
2444
2445         if (xprt_connected(xprt))
2446                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2447
2448         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2449                         "%llu %llu %lu %llu %llu\n",
2450                         transport->srcport,
2451                         xprt->stat.bind_count,
2452                         xprt->stat.connect_count,
2453                         xprt->stat.connect_time / HZ,
2454                         idle_time,
2455                         xprt->stat.sends,
2456                         xprt->stat.recvs,
2457                         xprt->stat.bad_xids,
2458                         xprt->stat.req_u,
2459                         xprt->stat.bklog_u,
2460                         xprt->stat.max_slots,
2461                         xprt->stat.sending_u,
2462                         xprt->stat.pending_u);
2463 }
2464
2465 /*
2466  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2467  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2468  * to use the server side send routines.
2469  */
2470 static int bc_malloc(struct rpc_task *task)
2471 {
2472         struct rpc_rqst *rqst = task->tk_rqstp;
2473         size_t size = rqst->rq_callsize;
2474         struct page *page;
2475         struct rpc_buffer *buf;
2476
2477         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2478                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2479                           size);
2480                 return -EINVAL;
2481         }
2482
2483         page = alloc_page(GFP_KERNEL);
2484         if (!page)
2485                 return -ENOMEM;
2486
2487         buf = page_address(page);
2488         buf->len = PAGE_SIZE;
2489
2490         rqst->rq_buffer = buf->data;
2491         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2492         return 0;
2493 }
2494
2495 /*
2496  * Free the space allocated in the bc_alloc routine
2497  */
2498 static void bc_free(struct rpc_task *task)
2499 {
2500         void *buffer = task->tk_rqstp->rq_buffer;
2501         struct rpc_buffer *buf;
2502
2503         buf = container_of(buffer, struct rpc_buffer, data);
2504         free_page((unsigned long)buf);
2505 }
2506
2507 static int bc_sendto(struct rpc_rqst *req)
2508 {
2509         struct xdr_buf *xdr = &req->rq_snd_buf;
2510         struct sock_xprt *transport =
2511                         container_of(req->rq_xprt, struct sock_xprt, xprt);
2512         struct msghdr msg = {
2513                 .msg_flags      = 0,
2514         };
2515         rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2516                                          (u32)xdr->len);
2517         unsigned int sent = 0;
2518         int err;
2519
2520         req->rq_xtime = ktime_get();
2521         err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2522         xdr_free_bvec(xdr);
2523         if (err < 0 || sent != (xdr->len + sizeof(marker)))
2524                 return -EAGAIN;
2525         return sent;
2526 }
2527
2528 /**
2529  * bc_send_request - Send a backchannel Call on a TCP socket
2530  * @req: rpc_rqst containing Call message to be sent
2531  *
2532  * xpt_mutex ensures @rqstp's whole message is written to the socket
2533  * without interruption.
2534  *
2535  * Return values:
2536  *   %0 if the message was sent successfully
2537  *   %ENOTCONN if the message was not sent
2538  */
2539 static int bc_send_request(struct rpc_rqst *req)
2540 {
2541         struct svc_xprt *xprt;
2542         int len;
2543
2544         /*
2545          * Get the server socket associated with this callback xprt
2546          */
2547         xprt = req->rq_xprt->bc_xprt;
2548
2549         /*
2550          * Grab the mutex to serialize data as the connection is shared
2551          * with the fore channel
2552          */
2553         mutex_lock(&xprt->xpt_mutex);
2554         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2555                 len = -ENOTCONN;
2556         else
2557                 len = bc_sendto(req);
2558         mutex_unlock(&xprt->xpt_mutex);
2559
2560         if (len > 0)
2561                 len = 0;
2562
2563         return len;
2564 }
2565
2566 /*
2567  * The close routine. Since this is client initiated, we do nothing
2568  */
2569
2570 static void bc_close(struct rpc_xprt *xprt)
2571 {
2572         xprt_disconnect_done(xprt);
2573 }
2574
2575 /*
2576  * The xprt destroy routine. Again, because this connection is client
2577  * initiated, we do nothing
2578  */
2579
2580 static void bc_destroy(struct rpc_xprt *xprt)
2581 {
2582         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2583
2584         xs_xprt_free(xprt);
2585         module_put(THIS_MODULE);
2586 }
2587
2588 static const struct rpc_xprt_ops xs_local_ops = {
2589         .reserve_xprt           = xprt_reserve_xprt,
2590         .release_xprt           = xprt_release_xprt,
2591         .alloc_slot             = xprt_alloc_slot,
2592         .free_slot              = xprt_free_slot,
2593         .rpcbind                = xs_local_rpcbind,
2594         .set_port               = xs_local_set_port,
2595         .connect                = xs_local_connect,
2596         .buf_alloc              = rpc_malloc,
2597         .buf_free               = rpc_free,
2598         .prepare_request        = xs_stream_prepare_request,
2599         .send_request           = xs_local_send_request,
2600         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2601         .close                  = xs_close,
2602         .destroy                = xs_destroy,
2603         .print_stats            = xs_local_print_stats,
2604         .enable_swap            = xs_enable_swap,
2605         .disable_swap           = xs_disable_swap,
2606 };
2607
2608 static const struct rpc_xprt_ops xs_udp_ops = {
2609         .set_buffer_size        = xs_udp_set_buffer_size,
2610         .reserve_xprt           = xprt_reserve_xprt_cong,
2611         .release_xprt           = xprt_release_xprt_cong,
2612         .alloc_slot             = xprt_alloc_slot,
2613         .free_slot              = xprt_free_slot,
2614         .rpcbind                = rpcb_getport_async,
2615         .set_port               = xs_set_port,
2616         .connect                = xs_connect,
2617         .buf_alloc              = rpc_malloc,
2618         .buf_free               = rpc_free,
2619         .send_request           = xs_udp_send_request,
2620         .wait_for_reply_request = xprt_wait_for_reply_request_rtt,
2621         .timer                  = xs_udp_timer,
2622         .release_request        = xprt_release_rqst_cong,
2623         .close                  = xs_close,
2624         .destroy                = xs_destroy,
2625         .print_stats            = xs_udp_print_stats,
2626         .enable_swap            = xs_enable_swap,
2627         .disable_swap           = xs_disable_swap,
2628         .inject_disconnect      = xs_inject_disconnect,
2629 };
2630
2631 static const struct rpc_xprt_ops xs_tcp_ops = {
2632         .reserve_xprt           = xprt_reserve_xprt,
2633         .release_xprt           = xprt_release_xprt,
2634         .alloc_slot             = xprt_alloc_slot,
2635         .free_slot              = xprt_free_slot,
2636         .rpcbind                = rpcb_getport_async,
2637         .set_port               = xs_set_port,
2638         .connect                = xs_connect,
2639         .buf_alloc              = rpc_malloc,
2640         .buf_free               = rpc_free,
2641         .prepare_request        = xs_stream_prepare_request,
2642         .send_request           = xs_tcp_send_request,
2643         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2644         .close                  = xs_tcp_shutdown,
2645         .destroy                = xs_destroy,
2646         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2647         .print_stats            = xs_tcp_print_stats,
2648         .enable_swap            = xs_enable_swap,
2649         .disable_swap           = xs_disable_swap,
2650         .inject_disconnect      = xs_inject_disconnect,
2651 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2652         .bc_setup               = xprt_setup_bc,
2653         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2654         .bc_num_slots           = xprt_bc_max_slots,
2655         .bc_free_rqst           = xprt_free_bc_rqst,
2656         .bc_destroy             = xprt_destroy_bc,
2657 #endif
2658 };
2659
2660 /*
2661  * The rpc_xprt_ops for the server backchannel
2662  */
2663
2664 static const struct rpc_xprt_ops bc_tcp_ops = {
2665         .reserve_xprt           = xprt_reserve_xprt,
2666         .release_xprt           = xprt_release_xprt,
2667         .alloc_slot             = xprt_alloc_slot,
2668         .free_slot              = xprt_free_slot,
2669         .buf_alloc              = bc_malloc,
2670         .buf_free               = bc_free,
2671         .send_request           = bc_send_request,
2672         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2673         .close                  = bc_close,
2674         .destroy                = bc_destroy,
2675         .print_stats            = xs_tcp_print_stats,
2676         .enable_swap            = xs_enable_swap,
2677         .disable_swap           = xs_disable_swap,
2678         .inject_disconnect      = xs_inject_disconnect,
2679 };
2680
2681 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2682 {
2683         static const struct sockaddr_in sin = {
2684                 .sin_family             = AF_INET,
2685                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2686         };
2687         static const struct sockaddr_in6 sin6 = {
2688                 .sin6_family            = AF_INET6,
2689                 .sin6_addr              = IN6ADDR_ANY_INIT,
2690         };
2691
2692         switch (family) {
2693         case AF_LOCAL:
2694                 break;
2695         case AF_INET:
2696                 memcpy(sap, &sin, sizeof(sin));
2697                 break;
2698         case AF_INET6:
2699                 memcpy(sap, &sin6, sizeof(sin6));
2700                 break;
2701         default:
2702                 dprintk("RPC:       %s: Bad address family\n", __func__);
2703                 return -EAFNOSUPPORT;
2704         }
2705         return 0;
2706 }
2707
2708 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2709                                       unsigned int slot_table_size,
2710                                       unsigned int max_slot_table_size)
2711 {
2712         struct rpc_xprt *xprt;
2713         struct sock_xprt *new;
2714
2715         if (args->addrlen > sizeof(xprt->addr)) {
2716                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2717                 return ERR_PTR(-EBADF);
2718         }
2719
2720         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2721                         max_slot_table_size);
2722         if (xprt == NULL) {
2723                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2724                                 "rpc_xprt\n");
2725                 return ERR_PTR(-ENOMEM);
2726         }
2727
2728         new = container_of(xprt, struct sock_xprt, xprt);
2729         mutex_init(&new->recv_mutex);
2730         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2731         xprt->addrlen = args->addrlen;
2732         if (args->srcaddr)
2733                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2734         else {
2735                 int err;
2736                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2737                                         (struct sockaddr *)&new->srcaddr);
2738                 if (err != 0) {
2739                         xprt_free(xprt);
2740                         return ERR_PTR(err);
2741                 }
2742         }
2743
2744         return xprt;
2745 }
2746
2747 static const struct rpc_timeout xs_local_default_timeout = {
2748         .to_initval = 10 * HZ,
2749         .to_maxval = 10 * HZ,
2750         .to_retries = 2,
2751 };
2752
2753 /**
2754  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2755  * @args: rpc transport creation arguments
2756  *
2757  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2758  */
2759 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2760 {
2761         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2762         struct sock_xprt *transport;
2763         struct rpc_xprt *xprt;
2764         struct rpc_xprt *ret;
2765
2766         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2767                         xprt_max_tcp_slot_table_entries);
2768         if (IS_ERR(xprt))
2769                 return xprt;
2770         transport = container_of(xprt, struct sock_xprt, xprt);
2771
2772         xprt->prot = 0;
2773         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2774
2775         xprt->bind_timeout = XS_BIND_TO;
2776         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2777         xprt->idle_timeout = XS_IDLE_DISC_TO;
2778
2779         xprt->ops = &xs_local_ops;
2780         xprt->timeout = &xs_local_default_timeout;
2781
2782         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2783         INIT_WORK(&transport->error_worker, xs_error_handle);
2784         INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2785
2786         switch (sun->sun_family) {
2787         case AF_LOCAL:
2788                 if (sun->sun_path[0] != '/') {
2789                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2790                                         sun->sun_path);
2791                         ret = ERR_PTR(-EINVAL);
2792                         goto out_err;
2793                 }
2794                 xprt_set_bound(xprt);
2795                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2796                 ret = ERR_PTR(xs_local_setup_socket(transport));
2797                 if (ret)
2798                         goto out_err;
2799                 break;
2800         default:
2801                 ret = ERR_PTR(-EAFNOSUPPORT);
2802                 goto out_err;
2803         }
2804
2805         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2806                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2807
2808         if (try_module_get(THIS_MODULE))
2809                 return xprt;
2810         ret = ERR_PTR(-EINVAL);
2811 out_err:
2812         xs_xprt_free(xprt);
2813         return ret;
2814 }
2815
2816 static const struct rpc_timeout xs_udp_default_timeout = {
2817         .to_initval = 5 * HZ,
2818         .to_maxval = 30 * HZ,
2819         .to_increment = 5 * HZ,
2820         .to_retries = 5,
2821 };
2822
2823 /**
2824  * xs_setup_udp - Set up transport to use a UDP socket
2825  * @args: rpc transport creation arguments
2826  *
2827  */
2828 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2829 {
2830         struct sockaddr *addr = args->dstaddr;
2831         struct rpc_xprt *xprt;
2832         struct sock_xprt *transport;
2833         struct rpc_xprt *ret;
2834
2835         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2836                         xprt_udp_slot_table_entries);
2837         if (IS_ERR(xprt))
2838                 return xprt;
2839         transport = container_of(xprt, struct sock_xprt, xprt);
2840
2841         xprt->prot = IPPROTO_UDP;
2842         /* XXX: header size can vary due to auth type, IPv6, etc. */
2843         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2844
2845         xprt->bind_timeout = XS_BIND_TO;
2846         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2847         xprt->idle_timeout = XS_IDLE_DISC_TO;
2848
2849         xprt->ops = &xs_udp_ops;
2850
2851         xprt->timeout = &xs_udp_default_timeout;
2852
2853         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2854         INIT_WORK(&transport->error_worker, xs_error_handle);
2855         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2856
2857         switch (addr->sa_family) {
2858         case AF_INET:
2859                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2860                         xprt_set_bound(xprt);
2861
2862                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2863                 break;
2864         case AF_INET6:
2865                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2866                         xprt_set_bound(xprt);
2867
2868                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2869                 break;
2870         default:
2871                 ret = ERR_PTR(-EAFNOSUPPORT);
2872                 goto out_err;
2873         }
2874
2875         if (xprt_bound(xprt))
2876                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2877                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2878                                 xprt->address_strings[RPC_DISPLAY_PORT],
2879                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2880         else
2881                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2882                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2883                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2884
2885         if (try_module_get(THIS_MODULE))
2886                 return xprt;
2887         ret = ERR_PTR(-EINVAL);
2888 out_err:
2889         xs_xprt_free(xprt);
2890         return ret;
2891 }
2892
2893 static const struct rpc_timeout xs_tcp_default_timeout = {
2894         .to_initval = 60 * HZ,
2895         .to_maxval = 60 * HZ,
2896         .to_retries = 2,
2897 };
2898
2899 /**
2900  * xs_setup_tcp - Set up transport to use a TCP socket
2901  * @args: rpc transport creation arguments
2902  *
2903  */
2904 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2905 {
2906         struct sockaddr *addr = args->dstaddr;
2907         struct rpc_xprt *xprt;
2908         struct sock_xprt *transport;
2909         struct rpc_xprt *ret;
2910         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2911
2912         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2913                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2914
2915         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2916                         max_slot_table_size);
2917         if (IS_ERR(xprt))
2918                 return xprt;
2919         transport = container_of(xprt, struct sock_xprt, xprt);
2920
2921         xprt->prot = IPPROTO_TCP;
2922         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2923
2924         xprt->bind_timeout = XS_BIND_TO;
2925         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2926         xprt->idle_timeout = XS_IDLE_DISC_TO;
2927
2928         xprt->ops = &xs_tcp_ops;
2929         xprt->timeout = &xs_tcp_default_timeout;
2930
2931         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2932         xprt->connect_timeout = xprt->timeout->to_initval *
2933                 (xprt->timeout->to_retries + 1);
2934
2935         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2936         INIT_WORK(&transport->error_worker, xs_error_handle);
2937         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2938
2939         switch (addr->sa_family) {
2940         case AF_INET:
2941                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2942                         xprt_set_bound(xprt);
2943
2944                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2945                 break;
2946         case AF_INET6:
2947                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2948                         xprt_set_bound(xprt);
2949
2950                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2951                 break;
2952         default:
2953                 ret = ERR_PTR(-EAFNOSUPPORT);
2954                 goto out_err;
2955         }
2956
2957         if (xprt_bound(xprt))
2958                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2959                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2960                                 xprt->address_strings[RPC_DISPLAY_PORT],
2961                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2962         else
2963                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2964                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2965                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2966
2967         if (try_module_get(THIS_MODULE))
2968                 return xprt;
2969         ret = ERR_PTR(-EINVAL);
2970 out_err:
2971         xs_xprt_free(xprt);
2972         return ret;
2973 }
2974
2975 /**
2976  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2977  * @args: rpc transport creation arguments
2978  *
2979  */
2980 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2981 {
2982         struct sockaddr *addr = args->dstaddr;
2983         struct rpc_xprt *xprt;
2984         struct sock_xprt *transport;
2985         struct svc_sock *bc_sock;
2986         struct rpc_xprt *ret;
2987
2988         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2989                         xprt_tcp_slot_table_entries);
2990         if (IS_ERR(xprt))
2991                 return xprt;
2992         transport = container_of(xprt, struct sock_xprt, xprt);
2993
2994         xprt->prot = IPPROTO_TCP;
2995         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2996         xprt->timeout = &xs_tcp_default_timeout;
2997
2998         /* backchannel */
2999         xprt_set_bound(xprt);
3000         xprt->bind_timeout = 0;
3001         xprt->reestablish_timeout = 0;
3002         xprt->idle_timeout = 0;
3003
3004         xprt->ops = &bc_tcp_ops;
3005
3006         switch (addr->sa_family) {
3007         case AF_INET:
3008                 xs_format_peer_addresses(xprt, "tcp",
3009                                          RPCBIND_NETID_TCP);
3010                 break;
3011         case AF_INET6:
3012                 xs_format_peer_addresses(xprt, "tcp",
3013                                    RPCBIND_NETID_TCP6);
3014                 break;
3015         default:
3016                 ret = ERR_PTR(-EAFNOSUPPORT);
3017                 goto out_err;
3018         }
3019
3020         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3021                         xprt->address_strings[RPC_DISPLAY_ADDR],
3022                         xprt->address_strings[RPC_DISPLAY_PORT],
3023                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3024
3025         /*
3026          * Once we've associated a backchannel xprt with a connection,
3027          * we want to keep it around as long as the connection lasts,
3028          * in case we need to start using it for a backchannel again;
3029          * this reference won't be dropped until bc_xprt is destroyed.
3030          */
3031         xprt_get(xprt);
3032         args->bc_xprt->xpt_bc_xprt = xprt;
3033         xprt->bc_xprt = args->bc_xprt;
3034         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3035         transport->sock = bc_sock->sk_sock;
3036         transport->inet = bc_sock->sk_sk;
3037
3038         /*
3039          * Since we don't want connections for the backchannel, we set
3040          * the xprt status to connected
3041          */
3042         xprt_set_connected(xprt);
3043
3044         if (try_module_get(THIS_MODULE))
3045                 return xprt;
3046
3047         args->bc_xprt->xpt_bc_xprt = NULL;
3048         args->bc_xprt->xpt_bc_xps = NULL;
3049         xprt_put(xprt);
3050         ret = ERR_PTR(-EINVAL);
3051 out_err:
3052         xs_xprt_free(xprt);
3053         return ret;
3054 }
3055
3056 static struct xprt_class        xs_local_transport = {
3057         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3058         .name           = "named UNIX socket",
3059         .owner          = THIS_MODULE,
3060         .ident          = XPRT_TRANSPORT_LOCAL,
3061         .setup          = xs_setup_local,
3062         .netid          = { "" },
3063 };
3064
3065 static struct xprt_class        xs_udp_transport = {
3066         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3067         .name           = "udp",
3068         .owner          = THIS_MODULE,
3069         .ident          = XPRT_TRANSPORT_UDP,
3070         .setup          = xs_setup_udp,
3071         .netid          = { "udp", "udp6", "" },
3072 };
3073
3074 static struct xprt_class        xs_tcp_transport = {
3075         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3076         .name           = "tcp",
3077         .owner          = THIS_MODULE,
3078         .ident          = XPRT_TRANSPORT_TCP,
3079         .setup          = xs_setup_tcp,
3080         .netid          = { "tcp", "tcp6", "" },
3081 };
3082
3083 static struct xprt_class        xs_bc_tcp_transport = {
3084         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3085         .name           = "tcp NFSv4.1 backchannel",
3086         .owner          = THIS_MODULE,
3087         .ident          = XPRT_TRANSPORT_BC_TCP,
3088         .setup          = xs_setup_bc_tcp,
3089         .netid          = { "" },
3090 };
3091
3092 /**
3093  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3094  *
3095  */
3096 int init_socket_xprt(void)
3097 {
3098         if (!sunrpc_table_header)
3099                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3100
3101         xprt_register_transport(&xs_local_transport);
3102         xprt_register_transport(&xs_udp_transport);
3103         xprt_register_transport(&xs_tcp_transport);
3104         xprt_register_transport(&xs_bc_tcp_transport);
3105
3106         return 0;
3107 }
3108
3109 /**
3110  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3111  *
3112  */
3113 void cleanup_socket_xprt(void)
3114 {
3115         if (sunrpc_table_header) {
3116                 unregister_sysctl_table(sunrpc_table_header);
3117                 sunrpc_table_header = NULL;
3118         }
3119
3120         xprt_unregister_transport(&xs_local_transport);
3121         xprt_unregister_transport(&xs_udp_transport);
3122         xprt_unregister_transport(&xs_tcp_transport);
3123         xprt_unregister_transport(&xs_bc_tcp_transport);
3124 }
3125
3126 static int param_set_uint_minmax(const char *val,
3127                 const struct kernel_param *kp,
3128                 unsigned int min, unsigned int max)
3129 {
3130         unsigned int num;
3131         int ret;
3132
3133         if (!val)
3134                 return -EINVAL;
3135         ret = kstrtouint(val, 0, &num);
3136         if (ret)
3137                 return ret;
3138         if (num < min || num > max)
3139                 return -EINVAL;
3140         *((unsigned int *)kp->arg) = num;
3141         return 0;
3142 }
3143
3144 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3145 {
3146         return param_set_uint_minmax(val, kp,
3147                         RPC_MIN_RESVPORT,
3148                         RPC_MAX_RESVPORT);
3149 }
3150
3151 static const struct kernel_param_ops param_ops_portnr = {
3152         .set = param_set_portnr,
3153         .get = param_get_uint,
3154 };
3155
3156 #define param_check_portnr(name, p) \
3157         __param_check(name, p, unsigned int);
3158
3159 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3160 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3161
3162 static int param_set_slot_table_size(const char *val,
3163                                      const struct kernel_param *kp)
3164 {
3165         return param_set_uint_minmax(val, kp,
3166                         RPC_MIN_SLOT_TABLE,
3167                         RPC_MAX_SLOT_TABLE);
3168 }
3169
3170 static const struct kernel_param_ops param_ops_slot_table_size = {
3171         .set = param_set_slot_table_size,
3172         .get = param_get_uint,
3173 };
3174
3175 #define param_check_slot_table_size(name, p) \
3176         __param_check(name, p, unsigned int);
3177
3178 static int param_set_max_slot_table_size(const char *val,
3179                                      const struct kernel_param *kp)
3180 {
3181         return param_set_uint_minmax(val, kp,
3182                         RPC_MIN_SLOT_TABLE,
3183                         RPC_MAX_SLOT_TABLE_LIMIT);
3184 }
3185
3186 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3187         .set = param_set_max_slot_table_size,
3188         .get = param_get_uint,
3189 };
3190
3191 #define param_check_max_slot_table_size(name, p) \
3192         __param_check(name, p, unsigned int);
3193
3194 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3195                    slot_table_size, 0644);
3196 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3197                    max_slot_table_size, 0644);
3198 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3199                    slot_table_size, 0644);