SUNRPC: ensure correct error is reported by xs_tcp_setup_socket()
[sfrench/cifs-2.6.git] / net / sunrpc / xprtsock.c
1 /*
2  * linux/net/sunrpc/xprtsock.c
3  *
4  * Client-side transport implementation for sockets.
5  *
6  * TCP callback races fixes (C) 1998 Red Hat
7  * TCP send fixes (C) 1998 Red Hat
8  * TCP NFS related read + write fixes
9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10  *
11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
12  * Fix behaviour when socket buffer is full.
13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14  *
15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16  *
17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
18  *   <gilles.quillard@bull.net>
19  */
20
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/capability.h>
26 #include <linux/pagemap.h>
27 #include <linux/errno.h>
28 #include <linux/socket.h>
29 #include <linux/in.h>
30 #include <linux/net.h>
31 #include <linux/mm.h>
32 #include <linux/un.h>
33 #include <linux/udp.h>
34 #include <linux/tcp.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/sched.h>
38 #include <linux/sunrpc/svcsock.h>
39 #include <linux/sunrpc/xprtsock.h>
40 #include <linux/file.h>
41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
42 #include <linux/sunrpc/bc_xprt.h>
43 #endif
44
45 #include <net/sock.h>
46 #include <net/checksum.h>
47 #include <net/udp.h>
48 #include <net/tcp.h>
49
50 #include <trace/events/sunrpc.h>
51
52 #include "sunrpc.h"
53
54 static void xs_close(struct rpc_xprt *xprt);
55 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
56                 struct socket *sock);
57
58 /*
59  * xprtsock tunables
60  */
61 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
62 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
63 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
64
65 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
66 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
67
68 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
69
70 #define XS_TCP_LINGER_TO        (15U * HZ)
71 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
72
73 /*
74  * We can register our own files under /proc/sys/sunrpc by
75  * calling register_sysctl_table() again.  The files in that
76  * directory become the union of all files registered there.
77  *
78  * We simply need to make sure that we don't collide with
79  * someone else's file names!
80  */
81
82 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
83 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
84 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
85 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
86 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
87
88 static struct ctl_table_header *sunrpc_table_header;
89
90 /*
91  * FIXME: changing the UDP slot table size should also resize the UDP
92  *        socket buffers for existing UDP transports
93  */
94 static struct ctl_table xs_tunables_table[] = {
95         {
96                 .procname       = "udp_slot_table_entries",
97                 .data           = &xprt_udp_slot_table_entries,
98                 .maxlen         = sizeof(unsigned int),
99                 .mode           = 0644,
100                 .proc_handler   = proc_dointvec_minmax,
101                 .extra1         = &min_slot_table_size,
102                 .extra2         = &max_slot_table_size
103         },
104         {
105                 .procname       = "tcp_slot_table_entries",
106                 .data           = &xprt_tcp_slot_table_entries,
107                 .maxlen         = sizeof(unsigned int),
108                 .mode           = 0644,
109                 .proc_handler   = proc_dointvec_minmax,
110                 .extra1         = &min_slot_table_size,
111                 .extra2         = &max_slot_table_size
112         },
113         {
114                 .procname       = "tcp_max_slot_table_entries",
115                 .data           = &xprt_max_tcp_slot_table_entries,
116                 .maxlen         = sizeof(unsigned int),
117                 .mode           = 0644,
118                 .proc_handler   = proc_dointvec_minmax,
119                 .extra1         = &min_slot_table_size,
120                 .extra2         = &max_tcp_slot_table_limit
121         },
122         {
123                 .procname       = "min_resvport",
124                 .data           = &xprt_min_resvport,
125                 .maxlen         = sizeof(unsigned int),
126                 .mode           = 0644,
127                 .proc_handler   = proc_dointvec_minmax,
128                 .extra1         = &xprt_min_resvport_limit,
129                 .extra2         = &xprt_max_resvport
130         },
131         {
132                 .procname       = "max_resvport",
133                 .data           = &xprt_max_resvport,
134                 .maxlen         = sizeof(unsigned int),
135                 .mode           = 0644,
136                 .proc_handler   = proc_dointvec_minmax,
137                 .extra1         = &xprt_min_resvport,
138                 .extra2         = &xprt_max_resvport_limit
139         },
140         {
141                 .procname       = "tcp_fin_timeout",
142                 .data           = &xs_tcp_fin_timeout,
143                 .maxlen         = sizeof(xs_tcp_fin_timeout),
144                 .mode           = 0644,
145                 .proc_handler   = proc_dointvec_jiffies,
146         },
147         { },
148 };
149
150 static struct ctl_table sunrpc_table[] = {
151         {
152                 .procname       = "sunrpc",
153                 .mode           = 0555,
154                 .child          = xs_tunables_table
155         },
156         { },
157 };
158
159 #endif
160
161 /*
162  * Wait duration for a reply from the RPC portmapper.
163  */
164 #define XS_BIND_TO              (60U * HZ)
165
166 /*
167  * Delay if a UDP socket connect error occurs.  This is most likely some
168  * kind of resource problem on the local host.
169  */
170 #define XS_UDP_REEST_TO         (2U * HZ)
171
172 /*
173  * The reestablish timeout allows clients to delay for a bit before attempting
174  * to reconnect to a server that just dropped our connection.
175  *
176  * We implement an exponential backoff when trying to reestablish a TCP
177  * transport connection with the server.  Some servers like to drop a TCP
178  * connection when they are overworked, so we start with a short timeout and
179  * increase over time if the server is down or not responding.
180  */
181 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
182
183 /*
184  * TCP idle timeout; client drops the transport socket if it is idle
185  * for this long.  Note that we also timeout UDP sockets to prevent
186  * holding port numbers when there is no RPC traffic.
187  */
188 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
189
190 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
191 # undef  RPC_DEBUG_DATA
192 # define RPCDBG_FACILITY        RPCDBG_TRANS
193 #endif
194
195 #ifdef RPC_DEBUG_DATA
196 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
197 {
198         u8 *buf = (u8 *) packet;
199         int j;
200
201         dprintk("RPC:       %s\n", msg);
202         for (j = 0; j < count && j < 128; j += 4) {
203                 if (!(j & 31)) {
204                         if (j)
205                                 dprintk("\n");
206                         dprintk("0x%04x ", j);
207                 }
208                 dprintk("%02x%02x%02x%02x ",
209                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
210         }
211         dprintk("\n");
212 }
213 #else
214 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
215 {
216         /* NOP */
217 }
218 #endif
219
220 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
221 {
222         return (struct rpc_xprt *) sk->sk_user_data;
223 }
224
225 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
226 {
227         return (struct sockaddr *) &xprt->addr;
228 }
229
230 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
231 {
232         return (struct sockaddr_un *) &xprt->addr;
233 }
234
235 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
236 {
237         return (struct sockaddr_in *) &xprt->addr;
238 }
239
240 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
241 {
242         return (struct sockaddr_in6 *) &xprt->addr;
243 }
244
245 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
246 {
247         struct sockaddr *sap = xs_addr(xprt);
248         struct sockaddr_in6 *sin6;
249         struct sockaddr_in *sin;
250         struct sockaddr_un *sun;
251         char buf[128];
252
253         switch (sap->sa_family) {
254         case AF_LOCAL:
255                 sun = xs_addr_un(xprt);
256                 strlcpy(buf, sun->sun_path, sizeof(buf));
257                 xprt->address_strings[RPC_DISPLAY_ADDR] =
258                                                 kstrdup(buf, GFP_KERNEL);
259                 break;
260         case AF_INET:
261                 (void)rpc_ntop(sap, buf, sizeof(buf));
262                 xprt->address_strings[RPC_DISPLAY_ADDR] =
263                                                 kstrdup(buf, GFP_KERNEL);
264                 sin = xs_addr_in(xprt);
265                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
266                 break;
267         case AF_INET6:
268                 (void)rpc_ntop(sap, buf, sizeof(buf));
269                 xprt->address_strings[RPC_DISPLAY_ADDR] =
270                                                 kstrdup(buf, GFP_KERNEL);
271                 sin6 = xs_addr_in6(xprt);
272                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
273                 break;
274         default:
275                 BUG();
276         }
277
278         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
279 }
280
281 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
282 {
283         struct sockaddr *sap = xs_addr(xprt);
284         char buf[128];
285
286         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
287         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
288
289         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
290         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
291 }
292
293 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
294                                      const char *protocol,
295                                      const char *netid)
296 {
297         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
298         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
299         xs_format_common_peer_addresses(xprt);
300         xs_format_common_peer_ports(xprt);
301 }
302
303 static void xs_update_peer_port(struct rpc_xprt *xprt)
304 {
305         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
306         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
307
308         xs_format_common_peer_ports(xprt);
309 }
310
311 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
312 {
313         unsigned int i;
314
315         for (i = 0; i < RPC_DISPLAY_MAX; i++)
316                 switch (i) {
317                 case RPC_DISPLAY_PROTO:
318                 case RPC_DISPLAY_NETID:
319                         continue;
320                 default:
321                         kfree(xprt->address_strings[i]);
322                 }
323 }
324
325 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
326
327 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
328 {
329         struct msghdr msg = {
330                 .msg_name       = addr,
331                 .msg_namelen    = addrlen,
332                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
333         };
334         struct kvec iov = {
335                 .iov_base       = vec->iov_base + base,
336                 .iov_len        = vec->iov_len - base,
337         };
338
339         if (iov.iov_len != 0)
340                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
341         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
342 }
343
344 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
345 {
346         ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
347                         int offset, size_t size, int flags);
348         struct page **ppage;
349         unsigned int remainder;
350         int err;
351
352         remainder = xdr->page_len - base;
353         base += xdr->page_base;
354         ppage = xdr->pages + (base >> PAGE_SHIFT);
355         base &= ~PAGE_MASK;
356         do_sendpage = sock->ops->sendpage;
357         if (!zerocopy)
358                 do_sendpage = sock_no_sendpage;
359         for(;;) {
360                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
361                 int flags = XS_SENDMSG_FLAGS;
362
363                 remainder -= len;
364                 if (more)
365                         flags |= MSG_MORE;
366                 if (remainder != 0)
367                         flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
368                 err = do_sendpage(sock, *ppage, base, len, flags);
369                 if (remainder == 0 || err != len)
370                         break;
371                 *sent_p += err;
372                 ppage++;
373                 base = 0;
374         }
375         if (err > 0) {
376                 *sent_p += err;
377                 err = 0;
378         }
379         return err;
380 }
381
382 /**
383  * xs_sendpages - write pages directly to a socket
384  * @sock: socket to send on
385  * @addr: UDP only -- address of destination
386  * @addrlen: UDP only -- length of destination address
387  * @xdr: buffer containing this request
388  * @base: starting position in the buffer
389  * @zerocopy: true if it is safe to use sendpage()
390  * @sent_p: return the total number of bytes successfully queued for sending
391  *
392  */
393 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
394 {
395         unsigned int remainder = xdr->len - base;
396         int err = 0;
397         int sent = 0;
398
399         if (unlikely(!sock))
400                 return -ENOTSOCK;
401
402         if (base != 0) {
403                 addr = NULL;
404                 addrlen = 0;
405         }
406
407         if (base < xdr->head[0].iov_len || addr != NULL) {
408                 unsigned int len = xdr->head[0].iov_len - base;
409                 remainder -= len;
410                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
411                 if (remainder == 0 || err != len)
412                         goto out;
413                 *sent_p += err;
414                 base = 0;
415         } else
416                 base -= xdr->head[0].iov_len;
417
418         if (base < xdr->page_len) {
419                 unsigned int len = xdr->page_len - base;
420                 remainder -= len;
421                 err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
422                 *sent_p += sent;
423                 if (remainder == 0 || sent != len)
424                         goto out;
425                 base = 0;
426         } else
427                 base -= xdr->page_len;
428
429         if (base >= xdr->tail[0].iov_len)
430                 return 0;
431         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
432 out:
433         if (err > 0) {
434                 *sent_p += err;
435                 err = 0;
436         }
437         return err;
438 }
439
440 static void xs_nospace_callback(struct rpc_task *task)
441 {
442         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
443
444         transport->inet->sk_write_pending--;
445 }
446
447 /**
448  * xs_nospace - place task on wait queue if transmit was incomplete
449  * @task: task to put to sleep
450  *
451  */
452 static int xs_nospace(struct rpc_task *task)
453 {
454         struct rpc_rqst *req = task->tk_rqstp;
455         struct rpc_xprt *xprt = req->rq_xprt;
456         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
457         struct sock *sk = transport->inet;
458         int ret = -EAGAIN;
459
460         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
461                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
462                         req->rq_slen);
463
464         /* Protect against races with write_space */
465         spin_lock_bh(&xprt->transport_lock);
466
467         /* Don't race with disconnect */
468         if (xprt_connected(xprt)) {
469                 /* wait for more buffer space */
470                 sk->sk_write_pending++;
471                 xprt_wait_for_buffer_space(task, xs_nospace_callback);
472         } else
473                 ret = -ENOTCONN;
474
475         spin_unlock_bh(&xprt->transport_lock);
476
477         /* Race breaker in case memory is freed before above code is called */
478         if (ret == -EAGAIN) {
479                 struct socket_wq *wq;
480
481                 rcu_read_lock();
482                 wq = rcu_dereference(sk->sk_wq);
483                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
484                 rcu_read_unlock();
485
486                 sk->sk_write_space(sk);
487         }
488         return ret;
489 }
490
491 /*
492  * Construct a stream transport record marker in @buf.
493  */
494 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
495 {
496         u32 reclen = buf->len - sizeof(rpc_fraghdr);
497         rpc_fraghdr *base = buf->head[0].iov_base;
498         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
499 }
500
501 /**
502  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
503  * @task: RPC task that manages the state of an RPC request
504  *
505  * Return values:
506  *        0:    The request has been sent
507  *   EAGAIN:    The socket was blocked, please call again later to
508  *              complete the request
509  * ENOTCONN:    Caller needs to invoke connect logic then call again
510  *    other:    Some other error occured, the request was not sent
511  */
512 static int xs_local_send_request(struct rpc_task *task)
513 {
514         struct rpc_rqst *req = task->tk_rqstp;
515         struct rpc_xprt *xprt = req->rq_xprt;
516         struct sock_xprt *transport =
517                                 container_of(xprt, struct sock_xprt, xprt);
518         struct xdr_buf *xdr = &req->rq_snd_buf;
519         int status;
520         int sent = 0;
521
522         xs_encode_stream_record_marker(&req->rq_snd_buf);
523
524         xs_pktdump("packet data:",
525                         req->rq_svec->iov_base, req->rq_svec->iov_len);
526
527         status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
528                               true, &sent);
529         dprintk("RPC:       %s(%u) = %d\n",
530                         __func__, xdr->len - req->rq_bytes_sent, status);
531
532         if (status == -EAGAIN && sock_writeable(transport->inet))
533                 status = -ENOBUFS;
534
535         if (likely(sent > 0) || status == 0) {
536                 req->rq_bytes_sent += sent;
537                 req->rq_xmit_bytes_sent += sent;
538                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
539                         req->rq_bytes_sent = 0;
540                         return 0;
541                 }
542                 status = -EAGAIN;
543         }
544
545         switch (status) {
546         case -ENOBUFS:
547                 break;
548         case -EAGAIN:
549                 status = xs_nospace(task);
550                 break;
551         default:
552                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
553                         -status);
554         case -EPIPE:
555                 xs_close(xprt);
556                 status = -ENOTCONN;
557         }
558
559         return status;
560 }
561
562 /**
563  * xs_udp_send_request - write an RPC request to a UDP socket
564  * @task: address of RPC task that manages the state of an RPC request
565  *
566  * Return values:
567  *        0:    The request has been sent
568  *   EAGAIN:    The socket was blocked, please call again later to
569  *              complete the request
570  * ENOTCONN:    Caller needs to invoke connect logic then call again
571  *    other:    Some other error occurred, the request was not sent
572  */
573 static int xs_udp_send_request(struct rpc_task *task)
574 {
575         struct rpc_rqst *req = task->tk_rqstp;
576         struct rpc_xprt *xprt = req->rq_xprt;
577         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
578         struct xdr_buf *xdr = &req->rq_snd_buf;
579         int sent = 0;
580         int status;
581
582         xs_pktdump("packet data:",
583                                 req->rq_svec->iov_base,
584                                 req->rq_svec->iov_len);
585
586         if (!xprt_bound(xprt))
587                 return -ENOTCONN;
588         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
589                               xdr, req->rq_bytes_sent, true, &sent);
590
591         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
592                         xdr->len - req->rq_bytes_sent, status);
593
594         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
595         if (status == -EPERM)
596                 goto process_status;
597
598         if (status == -EAGAIN && sock_writeable(transport->inet))
599                 status = -ENOBUFS;
600
601         if (sent > 0 || status == 0) {
602                 req->rq_xmit_bytes_sent += sent;
603                 if (sent >= req->rq_slen)
604                         return 0;
605                 /* Still some bytes left; set up for a retry later. */
606                 status = -EAGAIN;
607         }
608
609 process_status:
610         switch (status) {
611         case -ENOTSOCK:
612                 status = -ENOTCONN;
613                 /* Should we call xs_close() here? */
614                 break;
615         case -EAGAIN:
616                 status = xs_nospace(task);
617                 break;
618         case -ENETUNREACH:
619         case -ENOBUFS:
620         case -EPIPE:
621         case -ECONNREFUSED:
622         case -EPERM:
623                 /* When the server has died, an ICMP port unreachable message
624                  * prompts ECONNREFUSED. */
625                 break;
626         default:
627                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
628                         -status);
629         }
630
631         return status;
632 }
633
634 /**
635  * xs_tcp_send_request - write an RPC request to a TCP socket
636  * @task: address of RPC task that manages the state of an RPC request
637  *
638  * Return values:
639  *        0:    The request has been sent
640  *   EAGAIN:    The socket was blocked, please call again later to
641  *              complete the request
642  * ENOTCONN:    Caller needs to invoke connect logic then call again
643  *    other:    Some other error occurred, the request was not sent
644  *
645  * XXX: In the case of soft timeouts, should we eventually give up
646  *      if sendmsg is not able to make progress?
647  */
648 static int xs_tcp_send_request(struct rpc_task *task)
649 {
650         struct rpc_rqst *req = task->tk_rqstp;
651         struct rpc_xprt *xprt = req->rq_xprt;
652         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
653         struct xdr_buf *xdr = &req->rq_snd_buf;
654         bool zerocopy = true;
655         bool vm_wait = false;
656         int status;
657         int sent;
658
659         xs_encode_stream_record_marker(&req->rq_snd_buf);
660
661         xs_pktdump("packet data:",
662                                 req->rq_svec->iov_base,
663                                 req->rq_svec->iov_len);
664         /* Don't use zero copy if this is a resend. If the RPC call
665          * completes while the socket holds a reference to the pages,
666          * then we may end up resending corrupted data.
667          */
668         if (task->tk_flags & RPC_TASK_SENT)
669                 zerocopy = false;
670
671         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
672                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
673
674         /* Continue transmitting the packet/record. We must be careful
675          * to cope with writespace callbacks arriving _after_ we have
676          * called sendmsg(). */
677         while (1) {
678                 sent = 0;
679                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
680                                       req->rq_bytes_sent, zerocopy, &sent);
681
682                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
683                                 xdr->len - req->rq_bytes_sent, status);
684
685                 /* If we've sent the entire packet, immediately
686                  * reset the count of bytes sent. */
687                 req->rq_bytes_sent += sent;
688                 req->rq_xmit_bytes_sent += sent;
689                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
690                         req->rq_bytes_sent = 0;
691                         return 0;
692                 }
693
694                 WARN_ON_ONCE(sent == 0 && status == 0);
695
696                 if (status == -EAGAIN ) {
697                         /*
698                          * Return EAGAIN if we're sure we're hitting the
699                          * socket send buffer limits.
700                          */
701                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
702                                 break;
703                         /*
704                          * Did we hit a memory allocation failure?
705                          */
706                         if (sent == 0) {
707                                 status = -ENOBUFS;
708                                 if (vm_wait)
709                                         break;
710                                 /* Retry, knowing now that we're below the
711                                  * socket send buffer limit
712                                  */
713                                 vm_wait = true;
714                         }
715                         continue;
716                 }
717                 if (status < 0)
718                         break;
719                 vm_wait = false;
720         }
721
722         switch (status) {
723         case -ENOTSOCK:
724                 status = -ENOTCONN;
725                 /* Should we call xs_close() here? */
726                 break;
727         case -EAGAIN:
728                 status = xs_nospace(task);
729                 break;
730         case -ECONNRESET:
731         case -ECONNREFUSED:
732         case -ENOTCONN:
733         case -EADDRINUSE:
734         case -ENOBUFS:
735         case -EPIPE:
736                 break;
737         default:
738                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
739                         -status);
740         }
741
742         return status;
743 }
744
745 /**
746  * xs_tcp_release_xprt - clean up after a tcp transmission
747  * @xprt: transport
748  * @task: rpc task
749  *
750  * This cleans up if an error causes us to abort the transmission of a request.
751  * In this case, the socket may need to be reset in order to avoid confusing
752  * the server.
753  */
754 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
755 {
756         struct rpc_rqst *req;
757
758         if (task != xprt->snd_task)
759                 return;
760         if (task == NULL)
761                 goto out_release;
762         req = task->tk_rqstp;
763         if (req == NULL)
764                 goto out_release;
765         if (req->rq_bytes_sent == 0)
766                 goto out_release;
767         if (req->rq_bytes_sent == req->rq_snd_buf.len)
768                 goto out_release;
769         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
770 out_release:
771         xprt_release_xprt(xprt, task);
772 }
773
774 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
775 {
776         transport->old_data_ready = sk->sk_data_ready;
777         transport->old_state_change = sk->sk_state_change;
778         transport->old_write_space = sk->sk_write_space;
779         transport->old_error_report = sk->sk_error_report;
780 }
781
782 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
783 {
784         sk->sk_data_ready = transport->old_data_ready;
785         sk->sk_state_change = transport->old_state_change;
786         sk->sk_write_space = transport->old_write_space;
787         sk->sk_error_report = transport->old_error_report;
788 }
789
790 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
791 {
792         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
793
794         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
795 }
796
797 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
798 {
799         smp_mb__before_atomic();
800         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
801         clear_bit(XPRT_CLOSING, &xprt->state);
802         xs_sock_reset_state_flags(xprt);
803         smp_mb__after_atomic();
804 }
805
806 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
807 {
808         xs_sock_reset_connection_flags(xprt);
809         /* Mark transport as closed and wake up all pending tasks */
810         xprt_disconnect_done(xprt);
811 }
812
813 /**
814  * xs_error_report - callback to handle TCP socket state errors
815  * @sk: socket
816  *
817  * Note: we don't call sock_error() since there may be a rpc_task
818  * using the socket, and so we don't want to clear sk->sk_err.
819  */
820 static void xs_error_report(struct sock *sk)
821 {
822         struct rpc_xprt *xprt;
823         int err;
824
825         read_lock_bh(&sk->sk_callback_lock);
826         if (!(xprt = xprt_from_sock(sk)))
827                 goto out;
828
829         err = -sk->sk_err;
830         if (err == 0)
831                 goto out;
832         /* Is this a reset event? */
833         if (sk->sk_state == TCP_CLOSE)
834                 xs_sock_mark_closed(xprt);
835         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
836                         xprt, -err);
837         trace_rpc_socket_error(xprt, sk->sk_socket, err);
838         xprt_wake_pending_tasks(xprt, err);
839  out:
840         read_unlock_bh(&sk->sk_callback_lock);
841 }
842
843 static void xs_reset_transport(struct sock_xprt *transport)
844 {
845         struct socket *sock = transport->sock;
846         struct sock *sk = transport->inet;
847         struct rpc_xprt *xprt = &transport->xprt;
848
849         if (sk == NULL)
850                 return;
851
852         if (atomic_read(&transport->xprt.swapper))
853                 sk_clear_memalloc(sk);
854
855         kernel_sock_shutdown(sock, SHUT_RDWR);
856
857         mutex_lock(&transport->recv_mutex);
858         write_lock_bh(&sk->sk_callback_lock);
859         transport->inet = NULL;
860         transport->sock = NULL;
861
862         sk->sk_user_data = NULL;
863
864         xs_restore_old_callbacks(transport, sk);
865         xprt_clear_connected(xprt);
866         write_unlock_bh(&sk->sk_callback_lock);
867         xs_sock_reset_connection_flags(xprt);
868         mutex_unlock(&transport->recv_mutex);
869
870         trace_rpc_socket_close(xprt, sock);
871         sock_release(sock);
872 }
873
874 /**
875  * xs_close - close a socket
876  * @xprt: transport
877  *
878  * This is used when all requests are complete; ie, no DRC state remains
879  * on the server we want to save.
880  *
881  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
882  * xs_reset_transport() zeroing the socket from underneath a writer.
883  */
884 static void xs_close(struct rpc_xprt *xprt)
885 {
886         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
887
888         dprintk("RPC:       xs_close xprt %p\n", xprt);
889
890         xs_reset_transport(transport);
891         xprt->reestablish_timeout = 0;
892
893         xprt_disconnect_done(xprt);
894 }
895
896 static void xs_inject_disconnect(struct rpc_xprt *xprt)
897 {
898         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
899                 xprt);
900         xprt_disconnect_done(xprt);
901 }
902
903 static void xs_xprt_free(struct rpc_xprt *xprt)
904 {
905         xs_free_peer_addresses(xprt);
906         xprt_free(xprt);
907 }
908
909 /**
910  * xs_destroy - prepare to shutdown a transport
911  * @xprt: doomed transport
912  *
913  */
914 static void xs_destroy(struct rpc_xprt *xprt)
915 {
916         struct sock_xprt *transport = container_of(xprt,
917                         struct sock_xprt, xprt);
918         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
919
920         cancel_delayed_work_sync(&transport->connect_worker);
921         xs_close(xprt);
922         cancel_work_sync(&transport->recv_worker);
923         xs_xprt_free(xprt);
924         module_put(THIS_MODULE);
925 }
926
927 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
928 {
929         struct xdr_skb_reader desc = {
930                 .skb            = skb,
931                 .offset         = sizeof(rpc_fraghdr),
932                 .count          = skb->len - sizeof(rpc_fraghdr),
933         };
934
935         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
936                 return -1;
937         if (desc.count)
938                 return -1;
939         return 0;
940 }
941
942 /**
943  * xs_local_data_read_skb
944  * @xprt: transport
945  * @sk: socket
946  * @skb: skbuff
947  *
948  * Currently this assumes we can read the whole reply in a single gulp.
949  */
950 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
951                 struct sock *sk,
952                 struct sk_buff *skb)
953 {
954         struct rpc_task *task;
955         struct rpc_rqst *rovr;
956         int repsize, copied;
957         u32 _xid;
958         __be32 *xp;
959
960         repsize = skb->len - sizeof(rpc_fraghdr);
961         if (repsize < 4) {
962                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
963                 return;
964         }
965
966         /* Copy the XID from the skb... */
967         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
968         if (xp == NULL)
969                 return;
970
971         /* Look up and lock the request corresponding to the given XID */
972         spin_lock_bh(&xprt->transport_lock);
973         rovr = xprt_lookup_rqst(xprt, *xp);
974         if (!rovr)
975                 goto out_unlock;
976         task = rovr->rq_task;
977
978         copied = rovr->rq_private_buf.buflen;
979         if (copied > repsize)
980                 copied = repsize;
981
982         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
983                 dprintk("RPC:       sk_buff copy failed\n");
984                 goto out_unlock;
985         }
986
987         xprt_complete_rqst(task, copied);
988
989  out_unlock:
990         spin_unlock_bh(&xprt->transport_lock);
991 }
992
993 static void xs_local_data_receive(struct sock_xprt *transport)
994 {
995         struct sk_buff *skb;
996         struct sock *sk;
997         int err;
998
999         mutex_lock(&transport->recv_mutex);
1000         sk = transport->inet;
1001         if (sk == NULL)
1002                 goto out;
1003         for (;;) {
1004                 skb = skb_recv_datagram(sk, 0, 1, &err);
1005                 if (skb != NULL) {
1006                         xs_local_data_read_skb(&transport->xprt, sk, skb);
1007                         skb_free_datagram(sk, skb);
1008                         continue;
1009                 }
1010                 if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1011                         break;
1012         }
1013 out:
1014         mutex_unlock(&transport->recv_mutex);
1015 }
1016
1017 static void xs_local_data_receive_workfn(struct work_struct *work)
1018 {
1019         struct sock_xprt *transport =
1020                 container_of(work, struct sock_xprt, recv_worker);
1021         xs_local_data_receive(transport);
1022 }
1023
1024 /**
1025  * xs_udp_data_read_skb - receive callback for UDP sockets
1026  * @xprt: transport
1027  * @sk: socket
1028  * @skb: skbuff
1029  *
1030  */
1031 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1032                 struct sock *sk,
1033                 struct sk_buff *skb)
1034 {
1035         struct rpc_task *task;
1036         struct rpc_rqst *rovr;
1037         int repsize, copied;
1038         u32 _xid;
1039         __be32 *xp;
1040
1041         repsize = skb->len;
1042         if (repsize < 4) {
1043                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1044                 return;
1045         }
1046
1047         /* Copy the XID from the skb... */
1048         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1049         if (xp == NULL)
1050                 return;
1051
1052         /* Look up and lock the request corresponding to the given XID */
1053         spin_lock_bh(&xprt->transport_lock);
1054         rovr = xprt_lookup_rqst(xprt, *xp);
1055         if (!rovr)
1056                 goto out_unlock;
1057         task = rovr->rq_task;
1058
1059         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1060                 copied = repsize;
1061
1062         /* Suck it into the iovec, verify checksum if not done by hw. */
1063         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1064                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1065                 goto out_unlock;
1066         }
1067
1068         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1069
1070         xprt_adjust_cwnd(xprt, task, copied);
1071         xprt_complete_rqst(task, copied);
1072
1073  out_unlock:
1074         spin_unlock_bh(&xprt->transport_lock);
1075 }
1076
1077 static void xs_udp_data_receive(struct sock_xprt *transport)
1078 {
1079         struct sk_buff *skb;
1080         struct sock *sk;
1081         int err;
1082
1083         mutex_lock(&transport->recv_mutex);
1084         sk = transport->inet;
1085         if (sk == NULL)
1086                 goto out;
1087         for (;;) {
1088                 skb = skb_recv_udp(sk, 0, 1, &err);
1089                 if (skb != NULL) {
1090                         xs_udp_data_read_skb(&transport->xprt, sk, skb);
1091                         consume_skb(skb);
1092                         continue;
1093                 }
1094                 if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1095                         break;
1096         }
1097 out:
1098         mutex_unlock(&transport->recv_mutex);
1099 }
1100
1101 static void xs_udp_data_receive_workfn(struct work_struct *work)
1102 {
1103         struct sock_xprt *transport =
1104                 container_of(work, struct sock_xprt, recv_worker);
1105         xs_udp_data_receive(transport);
1106 }
1107
1108 /**
1109  * xs_data_ready - "data ready" callback for UDP sockets
1110  * @sk: socket with data to read
1111  *
1112  */
1113 static void xs_data_ready(struct sock *sk)
1114 {
1115         struct rpc_xprt *xprt;
1116
1117         read_lock_bh(&sk->sk_callback_lock);
1118         dprintk("RPC:       xs_data_ready...\n");
1119         xprt = xprt_from_sock(sk);
1120         if (xprt != NULL) {
1121                 struct sock_xprt *transport = container_of(xprt,
1122                                 struct sock_xprt, xprt);
1123                 transport->old_data_ready(sk);
1124                 /* Any data means we had a useful conversation, so
1125                  * then we don't need to delay the next reconnect
1126                  */
1127                 if (xprt->reestablish_timeout)
1128                         xprt->reestablish_timeout = 0;
1129                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1130                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1131         }
1132         read_unlock_bh(&sk->sk_callback_lock);
1133 }
1134
1135 /*
1136  * Helper function to force a TCP close if the server is sending
1137  * junk and/or it has put us in CLOSE_WAIT
1138  */
1139 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1140 {
1141         xprt_force_disconnect(xprt);
1142 }
1143
1144 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1145 {
1146         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1147         size_t len, used;
1148         char *p;
1149
1150         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1151         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1152         used = xdr_skb_read_bits(desc, p, len);
1153         transport->tcp_offset += used;
1154         if (used != len)
1155                 return;
1156
1157         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1158         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1159                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1160         else
1161                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1162         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1163
1164         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1165         transport->tcp_offset = 0;
1166
1167         /* Sanity check of the record length */
1168         if (unlikely(transport->tcp_reclen < 8)) {
1169                 dprintk("RPC:       invalid TCP record fragment length\n");
1170                 xs_tcp_force_close(xprt);
1171                 return;
1172         }
1173         dprintk("RPC:       reading TCP record fragment of length %d\n",
1174                         transport->tcp_reclen);
1175 }
1176
1177 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1178 {
1179         if (transport->tcp_offset == transport->tcp_reclen) {
1180                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1181                 transport->tcp_offset = 0;
1182                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1183                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1184                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1185                         transport->tcp_copied = 0;
1186                 }
1187         }
1188 }
1189
1190 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1191 {
1192         size_t len, used;
1193         char *p;
1194
1195         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1196         dprintk("RPC:       reading XID (%zu bytes)\n", len);
1197         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1198         used = xdr_skb_read_bits(desc, p, len);
1199         transport->tcp_offset += used;
1200         if (used != len)
1201                 return;
1202         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1203         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1204         transport->tcp_copied = 4;
1205         dprintk("RPC:       reading %s XID %08x\n",
1206                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1207                                                               : "request with",
1208                         ntohl(transport->tcp_xid));
1209         xs_tcp_check_fraghdr(transport);
1210 }
1211
1212 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1213                                        struct xdr_skb_reader *desc)
1214 {
1215         size_t len, used;
1216         u32 offset;
1217         char *p;
1218
1219         /*
1220          * We want transport->tcp_offset to be 8 at the end of this routine
1221          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1222          * When this function is called for the first time,
1223          * transport->tcp_offset is 4 (after having already read the xid).
1224          */
1225         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1226         len = sizeof(transport->tcp_calldir) - offset;
1227         dprintk("RPC:       reading CALL/REPLY flag (%zu bytes)\n", len);
1228         p = ((char *) &transport->tcp_calldir) + offset;
1229         used = xdr_skb_read_bits(desc, p, len);
1230         transport->tcp_offset += used;
1231         if (used != len)
1232                 return;
1233         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1234         /*
1235          * We don't yet have the XDR buffer, so we will write the calldir
1236          * out after we get the buffer from the 'struct rpc_rqst'
1237          */
1238         switch (ntohl(transport->tcp_calldir)) {
1239         case RPC_REPLY:
1240                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1241                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1242                 transport->tcp_flags |= TCP_RPC_REPLY;
1243                 break;
1244         case RPC_CALL:
1245                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1246                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1247                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1248                 break;
1249         default:
1250                 dprintk("RPC:       invalid request message type\n");
1251                 xs_tcp_force_close(&transport->xprt);
1252         }
1253         xs_tcp_check_fraghdr(transport);
1254 }
1255
1256 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1257                                      struct xdr_skb_reader *desc,
1258                                      struct rpc_rqst *req)
1259 {
1260         struct sock_xprt *transport =
1261                                 container_of(xprt, struct sock_xprt, xprt);
1262         struct xdr_buf *rcvbuf;
1263         size_t len;
1264         ssize_t r;
1265
1266         rcvbuf = &req->rq_private_buf;
1267
1268         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1269                 /*
1270                  * Save the RPC direction in the XDR buffer
1271                  */
1272                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1273                         &transport->tcp_calldir,
1274                         sizeof(transport->tcp_calldir));
1275                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1276                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1277         }
1278
1279         len = desc->count;
1280         if (len > transport->tcp_reclen - transport->tcp_offset) {
1281                 struct xdr_skb_reader my_desc;
1282
1283                 len = transport->tcp_reclen - transport->tcp_offset;
1284                 memcpy(&my_desc, desc, sizeof(my_desc));
1285                 my_desc.count = len;
1286                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1287                                           &my_desc, xdr_skb_read_bits);
1288                 desc->count -= r;
1289                 desc->offset += r;
1290         } else
1291                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1292                                           desc, xdr_skb_read_bits);
1293
1294         if (r > 0) {
1295                 transport->tcp_copied += r;
1296                 transport->tcp_offset += r;
1297         }
1298         if (r != len) {
1299                 /* Error when copying to the receive buffer,
1300                  * usually because we weren't able to allocate
1301                  * additional buffer pages. All we can do now
1302                  * is turn off TCP_RCV_COPY_DATA, so the request
1303                  * will not receive any additional updates,
1304                  * and time out.
1305                  * Any remaining data from this record will
1306                  * be discarded.
1307                  */
1308                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1309                 dprintk("RPC:       XID %08x truncated request\n",
1310                                 ntohl(transport->tcp_xid));
1311                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1312                                 "tcp_offset = %u, tcp_reclen = %u\n",
1313                                 xprt, transport->tcp_copied,
1314                                 transport->tcp_offset, transport->tcp_reclen);
1315                 return;
1316         }
1317
1318         dprintk("RPC:       XID %08x read %zd bytes\n",
1319                         ntohl(transport->tcp_xid), r);
1320         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1321                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1322                         transport->tcp_offset, transport->tcp_reclen);
1323
1324         if (transport->tcp_copied == req->rq_private_buf.buflen)
1325                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1326         else if (transport->tcp_offset == transport->tcp_reclen) {
1327                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1328                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1329         }
1330 }
1331
1332 /*
1333  * Finds the request corresponding to the RPC xid and invokes the common
1334  * tcp read code to read the data.
1335  */
1336 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1337                                     struct xdr_skb_reader *desc)
1338 {
1339         struct sock_xprt *transport =
1340                                 container_of(xprt, struct sock_xprt, xprt);
1341         struct rpc_rqst *req;
1342
1343         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1344
1345         /* Find and lock the request corresponding to this xid */
1346         spin_lock_bh(&xprt->transport_lock);
1347         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1348         if (!req) {
1349                 dprintk("RPC:       XID %08x request not found!\n",
1350                                 ntohl(transport->tcp_xid));
1351                 spin_unlock_bh(&xprt->transport_lock);
1352                 return -1;
1353         }
1354
1355         xs_tcp_read_common(xprt, desc, req);
1356
1357         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1358                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1359
1360         spin_unlock_bh(&xprt->transport_lock);
1361         return 0;
1362 }
1363
1364 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1365 /*
1366  * Obtains an rpc_rqst previously allocated and invokes the common
1367  * tcp read code to read the data.  The result is placed in the callback
1368  * queue.
1369  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1370  * connection and return -1.
1371  */
1372 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1373                                        struct xdr_skb_reader *desc)
1374 {
1375         struct sock_xprt *transport =
1376                                 container_of(xprt, struct sock_xprt, xprt);
1377         struct rpc_rqst *req;
1378
1379         /* Look up and lock the request corresponding to the given XID */
1380         spin_lock_bh(&xprt->transport_lock);
1381         req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1382         if (req == NULL) {
1383                 spin_unlock_bh(&xprt->transport_lock);
1384                 printk(KERN_WARNING "Callback slot table overflowed\n");
1385                 xprt_force_disconnect(xprt);
1386                 return -1;
1387         }
1388
1389         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1390         xs_tcp_read_common(xprt, desc, req);
1391
1392         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1393                 xprt_complete_bc_request(req, transport->tcp_copied);
1394         spin_unlock_bh(&xprt->transport_lock);
1395
1396         return 0;
1397 }
1398
1399 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1400                                         struct xdr_skb_reader *desc)
1401 {
1402         struct sock_xprt *transport =
1403                                 container_of(xprt, struct sock_xprt, xprt);
1404
1405         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1406                 xs_tcp_read_reply(xprt, desc) :
1407                 xs_tcp_read_callback(xprt, desc);
1408 }
1409
1410 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1411 {
1412         int ret;
1413
1414         ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1415                               SVC_SOCK_ANONYMOUS);
1416         if (ret < 0)
1417                 return ret;
1418         return 0;
1419 }
1420
1421 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1422 {
1423         return PAGE_SIZE;
1424 }
1425 #else
1426 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1427                                         struct xdr_skb_reader *desc)
1428 {
1429         return xs_tcp_read_reply(xprt, desc);
1430 }
1431 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1432
1433 /*
1434  * Read data off the transport.  This can be either an RPC_CALL or an
1435  * RPC_REPLY.  Relay the processing to helper functions.
1436  */
1437 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1438                                     struct xdr_skb_reader *desc)
1439 {
1440         struct sock_xprt *transport =
1441                                 container_of(xprt, struct sock_xprt, xprt);
1442
1443         if (_xs_tcp_read_data(xprt, desc) == 0)
1444                 xs_tcp_check_fraghdr(transport);
1445         else {
1446                 /*
1447                  * The transport_lock protects the request handling.
1448                  * There's no need to hold it to update the tcp_flags.
1449                  */
1450                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1451         }
1452 }
1453
1454 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1455 {
1456         size_t len;
1457
1458         len = transport->tcp_reclen - transport->tcp_offset;
1459         if (len > desc->count)
1460                 len = desc->count;
1461         desc->count -= len;
1462         desc->offset += len;
1463         transport->tcp_offset += len;
1464         dprintk("RPC:       discarded %zu bytes\n", len);
1465         xs_tcp_check_fraghdr(transport);
1466 }
1467
1468 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1469 {
1470         struct rpc_xprt *xprt = rd_desc->arg.data;
1471         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1472         struct xdr_skb_reader desc = {
1473                 .skb    = skb,
1474                 .offset = offset,
1475                 .count  = len,
1476         };
1477
1478         dprintk("RPC:       xs_tcp_data_recv started\n");
1479         do {
1480                 trace_xs_tcp_data_recv(transport);
1481                 /* Read in a new fragment marker if necessary */
1482                 /* Can we ever really expect to get completely empty fragments? */
1483                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1484                         xs_tcp_read_fraghdr(xprt, &desc);
1485                         continue;
1486                 }
1487                 /* Read in the xid if necessary */
1488                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1489                         xs_tcp_read_xid(transport, &desc);
1490                         continue;
1491                 }
1492                 /* Read in the call/reply flag */
1493                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1494                         xs_tcp_read_calldir(transport, &desc);
1495                         continue;
1496                 }
1497                 /* Read in the request data */
1498                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1499                         xs_tcp_read_data(xprt, &desc);
1500                         continue;
1501                 }
1502                 /* Skip over any trailing bytes on short reads */
1503                 xs_tcp_read_discard(transport, &desc);
1504         } while (desc.count);
1505         trace_xs_tcp_data_recv(transport);
1506         dprintk("RPC:       xs_tcp_data_recv done\n");
1507         return len - desc.count;
1508 }
1509
1510 static void xs_tcp_data_receive(struct sock_xprt *transport)
1511 {
1512         struct rpc_xprt *xprt = &transport->xprt;
1513         struct sock *sk;
1514         read_descriptor_t rd_desc = {
1515                 .count = 2*1024*1024,
1516                 .arg.data = xprt,
1517         };
1518         unsigned long total = 0;
1519         int read = 0;
1520
1521         mutex_lock(&transport->recv_mutex);
1522         sk = transport->inet;
1523         if (sk == NULL)
1524                 goto out;
1525
1526         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1527         for (;;) {
1528                 lock_sock(sk);
1529                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1530                 if (read <= 0) {
1531                         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1532                         release_sock(sk);
1533                         if (!test_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1534                                 break;
1535                 } else {
1536                         release_sock(sk);
1537                         total += read;
1538                 }
1539                 rd_desc.count = 65536;
1540         }
1541 out:
1542         mutex_unlock(&transport->recv_mutex);
1543         trace_xs_tcp_data_ready(xprt, read, total);
1544 }
1545
1546 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1547 {
1548         struct sock_xprt *transport =
1549                 container_of(work, struct sock_xprt, recv_worker);
1550         xs_tcp_data_receive(transport);
1551 }
1552
1553 /**
1554  * xs_tcp_state_change - callback to handle TCP socket state changes
1555  * @sk: socket whose state has changed
1556  *
1557  */
1558 static void xs_tcp_state_change(struct sock *sk)
1559 {
1560         struct rpc_xprt *xprt;
1561         struct sock_xprt *transport;
1562
1563         read_lock_bh(&sk->sk_callback_lock);
1564         if (!(xprt = xprt_from_sock(sk)))
1565                 goto out;
1566         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1567         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1568                         sk->sk_state, xprt_connected(xprt),
1569                         sock_flag(sk, SOCK_DEAD),
1570                         sock_flag(sk, SOCK_ZAPPED),
1571                         sk->sk_shutdown);
1572
1573         transport = container_of(xprt, struct sock_xprt, xprt);
1574         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1575         switch (sk->sk_state) {
1576         case TCP_ESTABLISHED:
1577                 spin_lock(&xprt->transport_lock);
1578                 if (!xprt_test_and_set_connected(xprt)) {
1579
1580                         /* Reset TCP record info */
1581                         transport->tcp_offset = 0;
1582                         transport->tcp_reclen = 0;
1583                         transport->tcp_copied = 0;
1584                         transport->tcp_flags =
1585                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1586                         xprt->connect_cookie++;
1587                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1588                         xprt_clear_connecting(xprt);
1589
1590                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1591                 }
1592                 spin_unlock(&xprt->transport_lock);
1593                 break;
1594         case TCP_FIN_WAIT1:
1595                 /* The client initiated a shutdown of the socket */
1596                 xprt->connect_cookie++;
1597                 xprt->reestablish_timeout = 0;
1598                 set_bit(XPRT_CLOSING, &xprt->state);
1599                 smp_mb__before_atomic();
1600                 clear_bit(XPRT_CONNECTED, &xprt->state);
1601                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1602                 smp_mb__after_atomic();
1603                 break;
1604         case TCP_CLOSE_WAIT:
1605                 /* The server initiated a shutdown of the socket */
1606                 xprt->connect_cookie++;
1607                 clear_bit(XPRT_CONNECTED, &xprt->state);
1608                 xs_tcp_force_close(xprt);
1609         case TCP_CLOSING:
1610                 /*
1611                  * If the server closed down the connection, make sure that
1612                  * we back off before reconnecting
1613                  */
1614                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1615                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1616                 break;
1617         case TCP_LAST_ACK:
1618                 set_bit(XPRT_CLOSING, &xprt->state);
1619                 smp_mb__before_atomic();
1620                 clear_bit(XPRT_CONNECTED, &xprt->state);
1621                 smp_mb__after_atomic();
1622                 break;
1623         case TCP_CLOSE:
1624                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1625                                         &transport->sock_state))
1626                         xprt_clear_connecting(xprt);
1627                 xs_sock_mark_closed(xprt);
1628         }
1629  out:
1630         read_unlock_bh(&sk->sk_callback_lock);
1631 }
1632
1633 static void xs_write_space(struct sock *sk)
1634 {
1635         struct socket_wq *wq;
1636         struct rpc_xprt *xprt;
1637
1638         if (!sk->sk_socket)
1639                 return;
1640         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1641
1642         if (unlikely(!(xprt = xprt_from_sock(sk))))
1643                 return;
1644         rcu_read_lock();
1645         wq = rcu_dereference(sk->sk_wq);
1646         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1647                 goto out;
1648
1649         xprt_write_space(xprt);
1650 out:
1651         rcu_read_unlock();
1652 }
1653
1654 /**
1655  * xs_udp_write_space - callback invoked when socket buffer space
1656  *                             becomes available
1657  * @sk: socket whose state has changed
1658  *
1659  * Called when more output buffer space is available for this socket.
1660  * We try not to wake our writers until they can make "significant"
1661  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1662  * with a bunch of small requests.
1663  */
1664 static void xs_udp_write_space(struct sock *sk)
1665 {
1666         read_lock_bh(&sk->sk_callback_lock);
1667
1668         /* from net/core/sock.c:sock_def_write_space */
1669         if (sock_writeable(sk))
1670                 xs_write_space(sk);
1671
1672         read_unlock_bh(&sk->sk_callback_lock);
1673 }
1674
1675 /**
1676  * xs_tcp_write_space - callback invoked when socket buffer space
1677  *                             becomes available
1678  * @sk: socket whose state has changed
1679  *
1680  * Called when more output buffer space is available for this socket.
1681  * We try not to wake our writers until they can make "significant"
1682  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1683  * with a bunch of small requests.
1684  */
1685 static void xs_tcp_write_space(struct sock *sk)
1686 {
1687         read_lock_bh(&sk->sk_callback_lock);
1688
1689         /* from net/core/stream.c:sk_stream_write_space */
1690         if (sk_stream_is_writeable(sk))
1691                 xs_write_space(sk);
1692
1693         read_unlock_bh(&sk->sk_callback_lock);
1694 }
1695
1696 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1697 {
1698         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1699         struct sock *sk = transport->inet;
1700
1701         if (transport->rcvsize) {
1702                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1703                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1704         }
1705         if (transport->sndsize) {
1706                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1707                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1708                 sk->sk_write_space(sk);
1709         }
1710 }
1711
1712 /**
1713  * xs_udp_set_buffer_size - set send and receive limits
1714  * @xprt: generic transport
1715  * @sndsize: requested size of send buffer, in bytes
1716  * @rcvsize: requested size of receive buffer, in bytes
1717  *
1718  * Set socket send and receive buffer size limits.
1719  */
1720 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1721 {
1722         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1723
1724         transport->sndsize = 0;
1725         if (sndsize)
1726                 transport->sndsize = sndsize + 1024;
1727         transport->rcvsize = 0;
1728         if (rcvsize)
1729                 transport->rcvsize = rcvsize + 1024;
1730
1731         xs_udp_do_set_buffer_size(xprt);
1732 }
1733
1734 /**
1735  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1736  * @task: task that timed out
1737  *
1738  * Adjust the congestion window after a retransmit timeout has occurred.
1739  */
1740 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1741 {
1742         spin_lock_bh(&xprt->transport_lock);
1743         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1744         spin_unlock_bh(&xprt->transport_lock);
1745 }
1746
1747 static unsigned short xs_get_random_port(void)
1748 {
1749         unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
1750         unsigned short rand = (unsigned short) prandom_u32() % range;
1751         return rand + xprt_min_resvport;
1752 }
1753
1754 /**
1755  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1756  * @sock: socket
1757  *
1758  * Note that this function has to be called on all sockets that share the
1759  * same port, and it must be called before binding.
1760  */
1761 static void xs_sock_set_reuseport(struct socket *sock)
1762 {
1763         int opt = 1;
1764
1765         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1766                         (char *)&opt, sizeof(opt));
1767 }
1768
1769 static unsigned short xs_sock_getport(struct socket *sock)
1770 {
1771         struct sockaddr_storage buf;
1772         int buflen;
1773         unsigned short port = 0;
1774
1775         if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1776                 goto out;
1777         switch (buf.ss_family) {
1778         case AF_INET6:
1779                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1780                 break;
1781         case AF_INET:
1782                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1783         }
1784 out:
1785         return port;
1786 }
1787
1788 /**
1789  * xs_set_port - reset the port number in the remote endpoint address
1790  * @xprt: generic transport
1791  * @port: new port number
1792  *
1793  */
1794 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1795 {
1796         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1797
1798         rpc_set_port(xs_addr(xprt), port);
1799         xs_update_peer_port(xprt);
1800 }
1801
1802 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1803 {
1804         if (transport->srcport == 0)
1805                 transport->srcport = xs_sock_getport(sock);
1806 }
1807
1808 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1809 {
1810         unsigned short port = transport->srcport;
1811
1812         if (port == 0 && transport->xprt.resvport)
1813                 port = xs_get_random_port();
1814         return port;
1815 }
1816
1817 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1818 {
1819         if (transport->srcport != 0)
1820                 transport->srcport = 0;
1821         if (!transport->xprt.resvport)
1822                 return 0;
1823         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1824                 return xprt_max_resvport;
1825         return --port;
1826 }
1827 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1828 {
1829         struct sockaddr_storage myaddr;
1830         int err, nloop = 0;
1831         unsigned short port = xs_get_srcport(transport);
1832         unsigned short last;
1833
1834         /*
1835          * If we are asking for any ephemeral port (i.e. port == 0 &&
1836          * transport->xprt.resvport == 0), don't bind.  Let the local
1837          * port selection happen implicitly when the socket is used
1838          * (for example at connect time).
1839          *
1840          * This ensures that we can continue to establish TCP
1841          * connections even when all local ephemeral ports are already
1842          * a part of some TCP connection.  This makes no difference
1843          * for UDP sockets, but also doens't harm them.
1844          *
1845          * If we're asking for any reserved port (i.e. port == 0 &&
1846          * transport->xprt.resvport == 1) xs_get_srcport above will
1847          * ensure that port is non-zero and we will bind as needed.
1848          */
1849         if (port == 0)
1850                 return 0;
1851
1852         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1853         do {
1854                 rpc_set_port((struct sockaddr *)&myaddr, port);
1855                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1856                                 transport->xprt.addrlen);
1857                 if (err == 0) {
1858                         transport->srcport = port;
1859                         break;
1860                 }
1861                 last = port;
1862                 port = xs_next_srcport(transport, port);
1863                 if (port > last)
1864                         nloop++;
1865         } while (err == -EADDRINUSE && nloop != 2);
1866
1867         if (myaddr.ss_family == AF_INET)
1868                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1869                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1870                                 port, err ? "failed" : "ok", err);
1871         else
1872                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1873                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1874                                 port, err ? "failed" : "ok", err);
1875         return err;
1876 }
1877
1878 /*
1879  * We don't support autobind on AF_LOCAL sockets
1880  */
1881 static void xs_local_rpcbind(struct rpc_task *task)
1882 {
1883         xprt_set_bound(task->tk_xprt);
1884 }
1885
1886 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1887 {
1888 }
1889
1890 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1891 static struct lock_class_key xs_key[2];
1892 static struct lock_class_key xs_slock_key[2];
1893
1894 static inline void xs_reclassify_socketu(struct socket *sock)
1895 {
1896         struct sock *sk = sock->sk;
1897
1898         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1899                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1900 }
1901
1902 static inline void xs_reclassify_socket4(struct socket *sock)
1903 {
1904         struct sock *sk = sock->sk;
1905
1906         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1907                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1908 }
1909
1910 static inline void xs_reclassify_socket6(struct socket *sock)
1911 {
1912         struct sock *sk = sock->sk;
1913
1914         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1915                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1916 }
1917
1918 static inline void xs_reclassify_socket(int family, struct socket *sock)
1919 {
1920         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1921                 return;
1922
1923         switch (family) {
1924         case AF_LOCAL:
1925                 xs_reclassify_socketu(sock);
1926                 break;
1927         case AF_INET:
1928                 xs_reclassify_socket4(sock);
1929                 break;
1930         case AF_INET6:
1931                 xs_reclassify_socket6(sock);
1932                 break;
1933         }
1934 }
1935 #else
1936 static inline void xs_reclassify_socket(int family, struct socket *sock)
1937 {
1938 }
1939 #endif
1940
1941 static void xs_dummy_setup_socket(struct work_struct *work)
1942 {
1943 }
1944
1945 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1946                 struct sock_xprt *transport, int family, int type,
1947                 int protocol, bool reuseport)
1948 {
1949         struct socket *sock;
1950         int err;
1951
1952         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1953         if (err < 0) {
1954                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1955                                 protocol, -err);
1956                 goto out;
1957         }
1958         xs_reclassify_socket(family, sock);
1959
1960         if (reuseport)
1961                 xs_sock_set_reuseport(sock);
1962
1963         err = xs_bind(transport, sock);
1964         if (err) {
1965                 sock_release(sock);
1966                 goto out;
1967         }
1968
1969         return sock;
1970 out:
1971         return ERR_PTR(err);
1972 }
1973
1974 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1975                                       struct socket *sock)
1976 {
1977         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1978                                                                         xprt);
1979
1980         if (!transport->inet) {
1981                 struct sock *sk = sock->sk;
1982
1983                 write_lock_bh(&sk->sk_callback_lock);
1984
1985                 xs_save_old_callbacks(transport, sk);
1986
1987                 sk->sk_user_data = xprt;
1988                 sk->sk_data_ready = xs_data_ready;
1989                 sk->sk_write_space = xs_udp_write_space;
1990                 sock_set_flag(sk, SOCK_FASYNC);
1991                 sk->sk_error_report = xs_error_report;
1992                 sk->sk_allocation = GFP_NOIO;
1993
1994                 xprt_clear_connected(xprt);
1995
1996                 /* Reset to new socket */
1997                 transport->sock = sock;
1998                 transport->inet = sk;
1999
2000                 write_unlock_bh(&sk->sk_callback_lock);
2001         }
2002
2003         /* Tell the socket layer to start connecting... */
2004         xprt->stat.connect_count++;
2005         xprt->stat.connect_start = jiffies;
2006         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
2007 }
2008
2009 /**
2010  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
2011  * @transport: socket transport to connect
2012  */
2013 static int xs_local_setup_socket(struct sock_xprt *transport)
2014 {
2015         struct rpc_xprt *xprt = &transport->xprt;
2016         struct socket *sock;
2017         int status = -EIO;
2018
2019         status = __sock_create(xprt->xprt_net, AF_LOCAL,
2020                                         SOCK_STREAM, 0, &sock, 1);
2021         if (status < 0) {
2022                 dprintk("RPC:       can't create AF_LOCAL "
2023                         "transport socket (%d).\n", -status);
2024                 goto out;
2025         }
2026         xs_reclassify_socket(AF_LOCAL, sock);
2027
2028         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
2029                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2030
2031         status = xs_local_finish_connecting(xprt, sock);
2032         trace_rpc_socket_connect(xprt, sock, status);
2033         switch (status) {
2034         case 0:
2035                 dprintk("RPC:       xprt %p connected to %s\n",
2036                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2037                 xprt_set_connected(xprt);
2038         case -ENOBUFS:
2039                 break;
2040         case -ENOENT:
2041                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
2042                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2043                 break;
2044         case -ECONNREFUSED:
2045                 dprintk("RPC:       xprt %p: connection refused for %s\n",
2046                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2047                 break;
2048         default:
2049                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2050                                 __func__, -status,
2051                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
2052         }
2053
2054 out:
2055         xprt_clear_connecting(xprt);
2056         xprt_wake_pending_tasks(xprt, status);
2057         return status;
2058 }
2059
2060 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2061 {
2062         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2063         int ret;
2064
2065          if (RPC_IS_ASYNC(task)) {
2066                 /*
2067                  * We want the AF_LOCAL connect to be resolved in the
2068                  * filesystem namespace of the process making the rpc
2069                  * call.  Thus we connect synchronously.
2070                  *
2071                  * If we want to support asynchronous AF_LOCAL calls,
2072                  * we'll need to figure out how to pass a namespace to
2073                  * connect.
2074                  */
2075                 rpc_exit(task, -ENOTCONN);
2076                 return;
2077         }
2078         ret = xs_local_setup_socket(transport);
2079         if (ret && !RPC_IS_SOFTCONN(task))
2080                 msleep_interruptible(15000);
2081 }
2082
2083 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2084 /*
2085  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2086  * know that we have exclusive access to the socket), to guard against
2087  * races with xs_reset_transport.
2088  */
2089 static void xs_set_memalloc(struct rpc_xprt *xprt)
2090 {
2091         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2092                         xprt);
2093
2094         /*
2095          * If there's no sock, then we have nothing to set. The
2096          * reconnecting process will get it for us.
2097          */
2098         if (!transport->inet)
2099                 return;
2100         if (atomic_read(&xprt->swapper))
2101                 sk_set_memalloc(transport->inet);
2102 }
2103
2104 /**
2105  * xs_enable_swap - Tag this transport as being used for swap.
2106  * @xprt: transport to tag
2107  *
2108  * Take a reference to this transport on behalf of the rpc_clnt, and
2109  * optionally mark it for swapping if it wasn't already.
2110  */
2111 static int
2112 xs_enable_swap(struct rpc_xprt *xprt)
2113 {
2114         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2115
2116         if (atomic_inc_return(&xprt->swapper) != 1)
2117                 return 0;
2118         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2119                 return -ERESTARTSYS;
2120         if (xs->inet)
2121                 sk_set_memalloc(xs->inet);
2122         xprt_release_xprt(xprt, NULL);
2123         return 0;
2124 }
2125
2126 /**
2127  * xs_disable_swap - Untag this transport as being used for swap.
2128  * @xprt: transport to tag
2129  *
2130  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2131  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2132  */
2133 static void
2134 xs_disable_swap(struct rpc_xprt *xprt)
2135 {
2136         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2137
2138         if (!atomic_dec_and_test(&xprt->swapper))
2139                 return;
2140         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2141                 return;
2142         if (xs->inet)
2143                 sk_clear_memalloc(xs->inet);
2144         xprt_release_xprt(xprt, NULL);
2145 }
2146 #else
2147 static void xs_set_memalloc(struct rpc_xprt *xprt)
2148 {
2149 }
2150
2151 static int
2152 xs_enable_swap(struct rpc_xprt *xprt)
2153 {
2154         return -EINVAL;
2155 }
2156
2157 static void
2158 xs_disable_swap(struct rpc_xprt *xprt)
2159 {
2160 }
2161 #endif
2162
2163 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2164 {
2165         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2166
2167         if (!transport->inet) {
2168                 struct sock *sk = sock->sk;
2169
2170                 write_lock_bh(&sk->sk_callback_lock);
2171
2172                 xs_save_old_callbacks(transport, sk);
2173
2174                 sk->sk_user_data = xprt;
2175                 sk->sk_data_ready = xs_data_ready;
2176                 sk->sk_write_space = xs_udp_write_space;
2177                 sock_set_flag(sk, SOCK_FASYNC);
2178                 sk->sk_allocation = GFP_NOIO;
2179
2180                 xprt_set_connected(xprt);
2181
2182                 /* Reset to new socket */
2183                 transport->sock = sock;
2184                 transport->inet = sk;
2185
2186                 xs_set_memalloc(xprt);
2187
2188                 write_unlock_bh(&sk->sk_callback_lock);
2189         }
2190         xs_udp_do_set_buffer_size(xprt);
2191
2192         xprt->stat.connect_start = jiffies;
2193 }
2194
2195 static void xs_udp_setup_socket(struct work_struct *work)
2196 {
2197         struct sock_xprt *transport =
2198                 container_of(work, struct sock_xprt, connect_worker.work);
2199         struct rpc_xprt *xprt = &transport->xprt;
2200         struct socket *sock = transport->sock;
2201         int status = -EIO;
2202
2203         sock = xs_create_sock(xprt, transport,
2204                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2205                         IPPROTO_UDP, false);
2206         if (IS_ERR(sock))
2207                 goto out;
2208
2209         dprintk("RPC:       worker connecting xprt %p via %s to "
2210                                 "%s (port %s)\n", xprt,
2211                         xprt->address_strings[RPC_DISPLAY_PROTO],
2212                         xprt->address_strings[RPC_DISPLAY_ADDR],
2213                         xprt->address_strings[RPC_DISPLAY_PORT]);
2214
2215         xs_udp_finish_connecting(xprt, sock);
2216         trace_rpc_socket_connect(xprt, sock, 0);
2217         status = 0;
2218 out:
2219         xprt_unlock_connect(xprt, transport);
2220         xprt_clear_connecting(xprt);
2221         xprt_wake_pending_tasks(xprt, status);
2222 }
2223
2224 /**
2225  * xs_tcp_shutdown - gracefully shut down a TCP socket
2226  * @xprt: transport
2227  *
2228  * Initiates a graceful shutdown of the TCP socket by calling the
2229  * equivalent of shutdown(SHUT_RDWR);
2230  */
2231 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2232 {
2233         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2234         struct socket *sock = transport->sock;
2235
2236         if (sock == NULL)
2237                 return;
2238         if (xprt_connected(xprt)) {
2239                 kernel_sock_shutdown(sock, SHUT_RDWR);
2240                 trace_rpc_socket_shutdown(xprt, sock);
2241         } else
2242                 xs_reset_transport(transport);
2243 }
2244
2245 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2246                 struct socket *sock)
2247 {
2248         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2249         unsigned int keepidle;
2250         unsigned int keepcnt;
2251         unsigned int opt_on = 1;
2252         unsigned int timeo;
2253
2254         spin_lock_bh(&xprt->transport_lock);
2255         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2256         keepcnt = xprt->timeout->to_retries + 1;
2257         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2258                 (xprt->timeout->to_retries + 1);
2259         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2260         spin_unlock_bh(&xprt->transport_lock);
2261
2262         /* TCP Keepalive options */
2263         kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2264                         (char *)&opt_on, sizeof(opt_on));
2265         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2266                         (char *)&keepidle, sizeof(keepidle));
2267         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2268                         (char *)&keepidle, sizeof(keepidle));
2269         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2270                         (char *)&keepcnt, sizeof(keepcnt));
2271
2272         /* TCP user timeout (see RFC5482) */
2273         kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2274                         (char *)&timeo, sizeof(timeo));
2275 }
2276
2277 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2278                 unsigned long connect_timeout,
2279                 unsigned long reconnect_timeout)
2280 {
2281         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2282         struct rpc_timeout to;
2283         unsigned long initval;
2284
2285         spin_lock_bh(&xprt->transport_lock);
2286         if (reconnect_timeout < xprt->max_reconnect_timeout)
2287                 xprt->max_reconnect_timeout = reconnect_timeout;
2288         if (connect_timeout < xprt->connect_timeout) {
2289                 memcpy(&to, xprt->timeout, sizeof(to));
2290                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2291                 /* Arbitrary lower limit */
2292                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2293                         initval = XS_TCP_INIT_REEST_TO << 1;
2294                 to.to_initval = initval;
2295                 to.to_maxval = initval;
2296                 memcpy(&transport->tcp_timeout, &to,
2297                                 sizeof(transport->tcp_timeout));
2298                 xprt->timeout = &transport->tcp_timeout;
2299                 xprt->connect_timeout = connect_timeout;
2300         }
2301         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2302         spin_unlock_bh(&xprt->transport_lock);
2303 }
2304
2305 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2306 {
2307         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2308         int ret = -ENOTCONN;
2309
2310         if (!transport->inet) {
2311                 struct sock *sk = sock->sk;
2312                 unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2313
2314                 /* Avoid temporary address, they are bad for long-lived
2315                  * connections such as NFS mounts.
2316                  * RFC4941, section 3.6 suggests that:
2317                  *    Individual applications, which have specific
2318                  *    knowledge about the normal duration of connections,
2319                  *    MAY override this as appropriate.
2320                  */
2321                 kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2322                                 (char *)&addr_pref, sizeof(addr_pref));
2323
2324                 xs_tcp_set_socket_timeouts(xprt, sock);
2325
2326                 write_lock_bh(&sk->sk_callback_lock);
2327
2328                 xs_save_old_callbacks(transport, sk);
2329
2330                 sk->sk_user_data = xprt;
2331                 sk->sk_data_ready = xs_data_ready;
2332                 sk->sk_state_change = xs_tcp_state_change;
2333                 sk->sk_write_space = xs_tcp_write_space;
2334                 sock_set_flag(sk, SOCK_FASYNC);
2335                 sk->sk_error_report = xs_error_report;
2336                 sk->sk_allocation = GFP_NOIO;
2337
2338                 /* socket options */
2339                 sock_reset_flag(sk, SOCK_LINGER);
2340                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2341
2342                 xprt_clear_connected(xprt);
2343
2344                 /* Reset to new socket */
2345                 transport->sock = sock;
2346                 transport->inet = sk;
2347
2348                 write_unlock_bh(&sk->sk_callback_lock);
2349         }
2350
2351         if (!xprt_bound(xprt))
2352                 goto out;
2353
2354         xs_set_memalloc(xprt);
2355
2356         /* Tell the socket layer to start connecting... */
2357         xprt->stat.connect_count++;
2358         xprt->stat.connect_start = jiffies;
2359         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2360         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2361         switch (ret) {
2362         case 0:
2363                 xs_set_srcport(transport, sock);
2364         case -EINPROGRESS:
2365                 /* SYN_SENT! */
2366                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2367                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2368                 break;
2369         case -EADDRNOTAVAIL:
2370                 /* Source port number is unavailable. Try a new one! */
2371                 transport->srcport = 0;
2372         }
2373 out:
2374         return ret;
2375 }
2376
2377 /**
2378  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2379  *
2380  * Invoked by a work queue tasklet.
2381  */
2382 static void xs_tcp_setup_socket(struct work_struct *work)
2383 {
2384         struct sock_xprt *transport =
2385                 container_of(work, struct sock_xprt, connect_worker.work);
2386         struct socket *sock = transport->sock;
2387         struct rpc_xprt *xprt = &transport->xprt;
2388         int status = -EIO;
2389
2390         if (!sock) {
2391                 sock = xs_create_sock(xprt, transport,
2392                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2393                                 IPPROTO_TCP, true);
2394                 if (IS_ERR(sock)) {
2395                         status = PTR_ERR(sock);
2396                         goto out;
2397                 }
2398         }
2399
2400         dprintk("RPC:       worker connecting xprt %p via %s to "
2401                                 "%s (port %s)\n", xprt,
2402                         xprt->address_strings[RPC_DISPLAY_PROTO],
2403                         xprt->address_strings[RPC_DISPLAY_ADDR],
2404                         xprt->address_strings[RPC_DISPLAY_PORT]);
2405
2406         status = xs_tcp_finish_connecting(xprt, sock);
2407         trace_rpc_socket_connect(xprt, sock, status);
2408         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2409                         xprt, -status, xprt_connected(xprt),
2410                         sock->sk->sk_state);
2411         switch (status) {
2412         default:
2413                 printk("%s: connect returned unhandled error %d\n",
2414                         __func__, status);
2415         case -EADDRNOTAVAIL:
2416                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2417                  * and retry
2418                  */
2419                 xs_tcp_force_close(xprt);
2420                 break;
2421         case 0:
2422         case -EINPROGRESS:
2423         case -EALREADY:
2424                 xprt_unlock_connect(xprt, transport);
2425                 return;
2426         case -EINVAL:
2427                 /* Happens, for instance, if the user specified a link
2428                  * local IPv6 address without a scope-id.
2429                  */
2430         case -ECONNREFUSED:
2431         case -ECONNRESET:
2432         case -ENETUNREACH:
2433         case -EADDRINUSE:
2434         case -ENOBUFS:
2435                 /*
2436                  * xs_tcp_force_close() wakes tasks with -EIO.
2437                  * We need to wake them first to ensure the
2438                  * correct error code.
2439                  */
2440                 xprt_wake_pending_tasks(xprt, status);
2441                 xs_tcp_force_close(xprt);
2442                 goto out;
2443         }
2444         status = -EAGAIN;
2445 out:
2446         xprt_unlock_connect(xprt, transport);
2447         xprt_clear_connecting(xprt);
2448         xprt_wake_pending_tasks(xprt, status);
2449 }
2450
2451 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2452 {
2453         unsigned long start, now = jiffies;
2454
2455         start = xprt->stat.connect_start + xprt->reestablish_timeout;
2456         if (time_after(start, now))
2457                 return start - now;
2458         return 0;
2459 }
2460
2461 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2462 {
2463         xprt->reestablish_timeout <<= 1;
2464         if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2465                 xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2466         if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2467                 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2468 }
2469
2470 /**
2471  * xs_connect - connect a socket to a remote endpoint
2472  * @xprt: pointer to transport structure
2473  * @task: address of RPC task that manages state of connect request
2474  *
2475  * TCP: If the remote end dropped the connection, delay reconnecting.
2476  *
2477  * UDP socket connects are synchronous, but we use a work queue anyway
2478  * to guarantee that even unprivileged user processes can set up a
2479  * socket on a privileged port.
2480  *
2481  * If a UDP socket connect fails, the delay behavior here prevents
2482  * retry floods (hard mounts).
2483  */
2484 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2485 {
2486         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2487         unsigned long delay = 0;
2488
2489         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2490
2491         if (transport->sock != NULL) {
2492                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2493                                 "seconds\n",
2494                                 xprt, xprt->reestablish_timeout / HZ);
2495
2496                 /* Start by resetting any existing state */
2497                 xs_reset_transport(transport);
2498
2499                 delay = xs_reconnect_delay(xprt);
2500                 xs_reconnect_backoff(xprt);
2501
2502         } else
2503                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2504
2505         queue_delayed_work(xprtiod_workqueue,
2506                         &transport->connect_worker,
2507                         delay);
2508 }
2509
2510 /**
2511  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2512  * @xprt: rpc_xprt struct containing statistics
2513  * @seq: output file
2514  *
2515  */
2516 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2517 {
2518         long idle_time = 0;
2519
2520         if (xprt_connected(xprt))
2521                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2522
2523         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2524                         "%llu %llu %lu %llu %llu\n",
2525                         xprt->stat.bind_count,
2526                         xprt->stat.connect_count,
2527                         xprt->stat.connect_time,
2528                         idle_time,
2529                         xprt->stat.sends,
2530                         xprt->stat.recvs,
2531                         xprt->stat.bad_xids,
2532                         xprt->stat.req_u,
2533                         xprt->stat.bklog_u,
2534                         xprt->stat.max_slots,
2535                         xprt->stat.sending_u,
2536                         xprt->stat.pending_u);
2537 }
2538
2539 /**
2540  * xs_udp_print_stats - display UDP socket-specifc stats
2541  * @xprt: rpc_xprt struct containing statistics
2542  * @seq: output file
2543  *
2544  */
2545 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2546 {
2547         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2548
2549         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2550                         "%lu %llu %llu\n",
2551                         transport->srcport,
2552                         xprt->stat.bind_count,
2553                         xprt->stat.sends,
2554                         xprt->stat.recvs,
2555                         xprt->stat.bad_xids,
2556                         xprt->stat.req_u,
2557                         xprt->stat.bklog_u,
2558                         xprt->stat.max_slots,
2559                         xprt->stat.sending_u,
2560                         xprt->stat.pending_u);
2561 }
2562
2563 /**
2564  * xs_tcp_print_stats - display TCP socket-specifc stats
2565  * @xprt: rpc_xprt struct containing statistics
2566  * @seq: output file
2567  *
2568  */
2569 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2570 {
2571         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2572         long idle_time = 0;
2573
2574         if (xprt_connected(xprt))
2575                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2576
2577         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2578                         "%llu %llu %lu %llu %llu\n",
2579                         transport->srcport,
2580                         xprt->stat.bind_count,
2581                         xprt->stat.connect_count,
2582                         xprt->stat.connect_time,
2583                         idle_time,
2584                         xprt->stat.sends,
2585                         xprt->stat.recvs,
2586                         xprt->stat.bad_xids,
2587                         xprt->stat.req_u,
2588                         xprt->stat.bklog_u,
2589                         xprt->stat.max_slots,
2590                         xprt->stat.sending_u,
2591                         xprt->stat.pending_u);
2592 }
2593
2594 /*
2595  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2596  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2597  * to use the server side send routines.
2598  */
2599 static int bc_malloc(struct rpc_task *task)
2600 {
2601         struct rpc_rqst *rqst = task->tk_rqstp;
2602         size_t size = rqst->rq_callsize;
2603         struct page *page;
2604         struct rpc_buffer *buf;
2605
2606         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2607                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2608                           size);
2609                 return -EINVAL;
2610         }
2611
2612         page = alloc_page(GFP_KERNEL);
2613         if (!page)
2614                 return -ENOMEM;
2615
2616         buf = page_address(page);
2617         buf->len = PAGE_SIZE;
2618
2619         rqst->rq_buffer = buf->data;
2620         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2621         return 0;
2622 }
2623
2624 /*
2625  * Free the space allocated in the bc_alloc routine
2626  */
2627 static void bc_free(struct rpc_task *task)
2628 {
2629         void *buffer = task->tk_rqstp->rq_buffer;
2630         struct rpc_buffer *buf;
2631
2632         buf = container_of(buffer, struct rpc_buffer, data);
2633         free_page((unsigned long)buf);
2634 }
2635
2636 /*
2637  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2638  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2639  */
2640 static int bc_sendto(struct rpc_rqst *req)
2641 {
2642         int len;
2643         struct xdr_buf *xbufp = &req->rq_snd_buf;
2644         struct rpc_xprt *xprt = req->rq_xprt;
2645         struct sock_xprt *transport =
2646                                 container_of(xprt, struct sock_xprt, xprt);
2647         struct socket *sock = transport->sock;
2648         unsigned long headoff;
2649         unsigned long tailoff;
2650
2651         xs_encode_stream_record_marker(xbufp);
2652
2653         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2654         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2655         len = svc_send_common(sock, xbufp,
2656                               virt_to_page(xbufp->head[0].iov_base), headoff,
2657                               xbufp->tail[0].iov_base, tailoff);
2658
2659         if (len != xbufp->len) {
2660                 printk(KERN_NOTICE "Error sending entire callback!\n");
2661                 len = -EAGAIN;
2662         }
2663
2664         return len;
2665 }
2666
2667 /*
2668  * The send routine. Borrows from svc_send
2669  */
2670 static int bc_send_request(struct rpc_task *task)
2671 {
2672         struct rpc_rqst *req = task->tk_rqstp;
2673         struct svc_xprt *xprt;
2674         int len;
2675
2676         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2677         /*
2678          * Get the server socket associated with this callback xprt
2679          */
2680         xprt = req->rq_xprt->bc_xprt;
2681
2682         /*
2683          * Grab the mutex to serialize data as the connection is shared
2684          * with the fore channel
2685          */
2686         if (!mutex_trylock(&xprt->xpt_mutex)) {
2687                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2688                 if (!mutex_trylock(&xprt->xpt_mutex))
2689                         return -EAGAIN;
2690                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2691         }
2692         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2693                 len = -ENOTCONN;
2694         else
2695                 len = bc_sendto(req);
2696         mutex_unlock(&xprt->xpt_mutex);
2697
2698         if (len > 0)
2699                 len = 0;
2700
2701         return len;
2702 }
2703
2704 /*
2705  * The close routine. Since this is client initiated, we do nothing
2706  */
2707
2708 static void bc_close(struct rpc_xprt *xprt)
2709 {
2710 }
2711
2712 /*
2713  * The xprt destroy routine. Again, because this connection is client
2714  * initiated, we do nothing
2715  */
2716
2717 static void bc_destroy(struct rpc_xprt *xprt)
2718 {
2719         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2720
2721         xs_xprt_free(xprt);
2722         module_put(THIS_MODULE);
2723 }
2724
2725 static struct rpc_xprt_ops xs_local_ops = {
2726         .reserve_xprt           = xprt_reserve_xprt,
2727         .release_xprt           = xs_tcp_release_xprt,
2728         .alloc_slot             = xprt_alloc_slot,
2729         .rpcbind                = xs_local_rpcbind,
2730         .set_port               = xs_local_set_port,
2731         .connect                = xs_local_connect,
2732         .buf_alloc              = rpc_malloc,
2733         .buf_free               = rpc_free,
2734         .send_request           = xs_local_send_request,
2735         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2736         .close                  = xs_close,
2737         .destroy                = xs_destroy,
2738         .print_stats            = xs_local_print_stats,
2739         .enable_swap            = xs_enable_swap,
2740         .disable_swap           = xs_disable_swap,
2741 };
2742
2743 static struct rpc_xprt_ops xs_udp_ops = {
2744         .set_buffer_size        = xs_udp_set_buffer_size,
2745         .reserve_xprt           = xprt_reserve_xprt_cong,
2746         .release_xprt           = xprt_release_xprt_cong,
2747         .alloc_slot             = xprt_alloc_slot,
2748         .rpcbind                = rpcb_getport_async,
2749         .set_port               = xs_set_port,
2750         .connect                = xs_connect,
2751         .buf_alloc              = rpc_malloc,
2752         .buf_free               = rpc_free,
2753         .send_request           = xs_udp_send_request,
2754         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2755         .timer                  = xs_udp_timer,
2756         .release_request        = xprt_release_rqst_cong,
2757         .close                  = xs_close,
2758         .destroy                = xs_destroy,
2759         .print_stats            = xs_udp_print_stats,
2760         .enable_swap            = xs_enable_swap,
2761         .disable_swap           = xs_disable_swap,
2762         .inject_disconnect      = xs_inject_disconnect,
2763 };
2764
2765 static struct rpc_xprt_ops xs_tcp_ops = {
2766         .reserve_xprt           = xprt_reserve_xprt,
2767         .release_xprt           = xs_tcp_release_xprt,
2768         .alloc_slot             = xprt_lock_and_alloc_slot,
2769         .rpcbind                = rpcb_getport_async,
2770         .set_port               = xs_set_port,
2771         .connect                = xs_connect,
2772         .buf_alloc              = rpc_malloc,
2773         .buf_free               = rpc_free,
2774         .send_request           = xs_tcp_send_request,
2775         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2776         .close                  = xs_tcp_shutdown,
2777         .destroy                = xs_destroy,
2778         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2779         .print_stats            = xs_tcp_print_stats,
2780         .enable_swap            = xs_enable_swap,
2781         .disable_swap           = xs_disable_swap,
2782         .inject_disconnect      = xs_inject_disconnect,
2783 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2784         .bc_setup               = xprt_setup_bc,
2785         .bc_up                  = xs_tcp_bc_up,
2786         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2787         .bc_free_rqst           = xprt_free_bc_rqst,
2788         .bc_destroy             = xprt_destroy_bc,
2789 #endif
2790 };
2791
2792 /*
2793  * The rpc_xprt_ops for the server backchannel
2794  */
2795
2796 static struct rpc_xprt_ops bc_tcp_ops = {
2797         .reserve_xprt           = xprt_reserve_xprt,
2798         .release_xprt           = xprt_release_xprt,
2799         .alloc_slot             = xprt_alloc_slot,
2800         .buf_alloc              = bc_malloc,
2801         .buf_free               = bc_free,
2802         .send_request           = bc_send_request,
2803         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2804         .close                  = bc_close,
2805         .destroy                = bc_destroy,
2806         .print_stats            = xs_tcp_print_stats,
2807         .enable_swap            = xs_enable_swap,
2808         .disable_swap           = xs_disable_swap,
2809         .inject_disconnect      = xs_inject_disconnect,
2810 };
2811
2812 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2813 {
2814         static const struct sockaddr_in sin = {
2815                 .sin_family             = AF_INET,
2816                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2817         };
2818         static const struct sockaddr_in6 sin6 = {
2819                 .sin6_family            = AF_INET6,
2820                 .sin6_addr              = IN6ADDR_ANY_INIT,
2821         };
2822
2823         switch (family) {
2824         case AF_LOCAL:
2825                 break;
2826         case AF_INET:
2827                 memcpy(sap, &sin, sizeof(sin));
2828                 break;
2829         case AF_INET6:
2830                 memcpy(sap, &sin6, sizeof(sin6));
2831                 break;
2832         default:
2833                 dprintk("RPC:       %s: Bad address family\n", __func__);
2834                 return -EAFNOSUPPORT;
2835         }
2836         return 0;
2837 }
2838
2839 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2840                                       unsigned int slot_table_size,
2841                                       unsigned int max_slot_table_size)
2842 {
2843         struct rpc_xprt *xprt;
2844         struct sock_xprt *new;
2845
2846         if (args->addrlen > sizeof(xprt->addr)) {
2847                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2848                 return ERR_PTR(-EBADF);
2849         }
2850
2851         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2852                         max_slot_table_size);
2853         if (xprt == NULL) {
2854                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2855                                 "rpc_xprt\n");
2856                 return ERR_PTR(-ENOMEM);
2857         }
2858
2859         new = container_of(xprt, struct sock_xprt, xprt);
2860         mutex_init(&new->recv_mutex);
2861         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2862         xprt->addrlen = args->addrlen;
2863         if (args->srcaddr)
2864                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2865         else {
2866                 int err;
2867                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2868                                         (struct sockaddr *)&new->srcaddr);
2869                 if (err != 0) {
2870                         xprt_free(xprt);
2871                         return ERR_PTR(err);
2872                 }
2873         }
2874
2875         return xprt;
2876 }
2877
2878 static const struct rpc_timeout xs_local_default_timeout = {
2879         .to_initval = 10 * HZ,
2880         .to_maxval = 10 * HZ,
2881         .to_retries = 2,
2882 };
2883
2884 /**
2885  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2886  * @args: rpc transport creation arguments
2887  *
2888  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2889  */
2890 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2891 {
2892         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2893         struct sock_xprt *transport;
2894         struct rpc_xprt *xprt;
2895         struct rpc_xprt *ret;
2896
2897         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2898                         xprt_max_tcp_slot_table_entries);
2899         if (IS_ERR(xprt))
2900                 return xprt;
2901         transport = container_of(xprt, struct sock_xprt, xprt);
2902
2903         xprt->prot = 0;
2904         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2905         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2906
2907         xprt->bind_timeout = XS_BIND_TO;
2908         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2909         xprt->idle_timeout = XS_IDLE_DISC_TO;
2910
2911         xprt->ops = &xs_local_ops;
2912         xprt->timeout = &xs_local_default_timeout;
2913
2914         INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2915         INIT_DELAYED_WORK(&transport->connect_worker,
2916                         xs_dummy_setup_socket);
2917
2918         switch (sun->sun_family) {
2919         case AF_LOCAL:
2920                 if (sun->sun_path[0] != '/') {
2921                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2922                                         sun->sun_path);
2923                         ret = ERR_PTR(-EINVAL);
2924                         goto out_err;
2925                 }
2926                 xprt_set_bound(xprt);
2927                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2928                 ret = ERR_PTR(xs_local_setup_socket(transport));
2929                 if (ret)
2930                         goto out_err;
2931                 break;
2932         default:
2933                 ret = ERR_PTR(-EAFNOSUPPORT);
2934                 goto out_err;
2935         }
2936
2937         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2938                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2939
2940         if (try_module_get(THIS_MODULE))
2941                 return xprt;
2942         ret = ERR_PTR(-EINVAL);
2943 out_err:
2944         xs_xprt_free(xprt);
2945         return ret;
2946 }
2947
2948 static const struct rpc_timeout xs_udp_default_timeout = {
2949         .to_initval = 5 * HZ,
2950         .to_maxval = 30 * HZ,
2951         .to_increment = 5 * HZ,
2952         .to_retries = 5,
2953 };
2954
2955 /**
2956  * xs_setup_udp - Set up transport to use a UDP socket
2957  * @args: rpc transport creation arguments
2958  *
2959  */
2960 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2961 {
2962         struct sockaddr *addr = args->dstaddr;
2963         struct rpc_xprt *xprt;
2964         struct sock_xprt *transport;
2965         struct rpc_xprt *ret;
2966
2967         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2968                         xprt_udp_slot_table_entries);
2969         if (IS_ERR(xprt))
2970                 return xprt;
2971         transport = container_of(xprt, struct sock_xprt, xprt);
2972
2973         xprt->prot = IPPROTO_UDP;
2974         xprt->tsh_size = 0;
2975         /* XXX: header size can vary due to auth type, IPv6, etc. */
2976         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2977
2978         xprt->bind_timeout = XS_BIND_TO;
2979         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2980         xprt->idle_timeout = XS_IDLE_DISC_TO;
2981
2982         xprt->ops = &xs_udp_ops;
2983
2984         xprt->timeout = &xs_udp_default_timeout;
2985
2986         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2987         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2988
2989         switch (addr->sa_family) {
2990         case AF_INET:
2991                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2992                         xprt_set_bound(xprt);
2993
2994                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2995                 break;
2996         case AF_INET6:
2997                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2998                         xprt_set_bound(xprt);
2999
3000                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
3001                 break;
3002         default:
3003                 ret = ERR_PTR(-EAFNOSUPPORT);
3004                 goto out_err;
3005         }
3006
3007         if (xprt_bound(xprt))
3008                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3009                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3010                                 xprt->address_strings[RPC_DISPLAY_PORT],
3011                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3012         else
3013                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3014                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3015                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3016
3017         if (try_module_get(THIS_MODULE))
3018                 return xprt;
3019         ret = ERR_PTR(-EINVAL);
3020 out_err:
3021         xs_xprt_free(xprt);
3022         return ret;
3023 }
3024
3025 static const struct rpc_timeout xs_tcp_default_timeout = {
3026         .to_initval = 60 * HZ,
3027         .to_maxval = 60 * HZ,
3028         .to_retries = 2,
3029 };
3030
3031 /**
3032  * xs_setup_tcp - Set up transport to use a TCP socket
3033  * @args: rpc transport creation arguments
3034  *
3035  */
3036 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
3037 {
3038         struct sockaddr *addr = args->dstaddr;
3039         struct rpc_xprt *xprt;
3040         struct sock_xprt *transport;
3041         struct rpc_xprt *ret;
3042         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3043
3044         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3045                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3046
3047         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3048                         max_slot_table_size);
3049         if (IS_ERR(xprt))
3050                 return xprt;
3051         transport = container_of(xprt, struct sock_xprt, xprt);
3052
3053         xprt->prot = IPPROTO_TCP;
3054         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3055         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3056
3057         xprt->bind_timeout = XS_BIND_TO;
3058         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3059         xprt->idle_timeout = XS_IDLE_DISC_TO;
3060
3061         xprt->ops = &xs_tcp_ops;
3062         xprt->timeout = &xs_tcp_default_timeout;
3063
3064         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3065         xprt->connect_timeout = xprt->timeout->to_initval *
3066                 (xprt->timeout->to_retries + 1);
3067
3068         INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
3069         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3070
3071         switch (addr->sa_family) {
3072         case AF_INET:
3073                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3074                         xprt_set_bound(xprt);
3075
3076                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3077                 break;
3078         case AF_INET6:
3079                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3080                         xprt_set_bound(xprt);
3081
3082                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3083                 break;
3084         default:
3085                 ret = ERR_PTR(-EAFNOSUPPORT);
3086                 goto out_err;
3087         }
3088
3089         if (xprt_bound(xprt))
3090                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3091                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3092                                 xprt->address_strings[RPC_DISPLAY_PORT],
3093                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3094         else
3095                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3096                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3097                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3098
3099         if (try_module_get(THIS_MODULE))
3100                 return xprt;
3101         ret = ERR_PTR(-EINVAL);
3102 out_err:
3103         xs_xprt_free(xprt);
3104         return ret;
3105 }
3106
3107 /**
3108  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3109  * @args: rpc transport creation arguments
3110  *
3111  */
3112 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3113 {
3114         struct sockaddr *addr = args->dstaddr;
3115         struct rpc_xprt *xprt;
3116         struct sock_xprt *transport;
3117         struct svc_sock *bc_sock;
3118         struct rpc_xprt *ret;
3119
3120         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3121                         xprt_tcp_slot_table_entries);
3122         if (IS_ERR(xprt))
3123                 return xprt;
3124         transport = container_of(xprt, struct sock_xprt, xprt);
3125
3126         xprt->prot = IPPROTO_TCP;
3127         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3128         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3129         xprt->timeout = &xs_tcp_default_timeout;
3130
3131         /* backchannel */
3132         xprt_set_bound(xprt);
3133         xprt->bind_timeout = 0;
3134         xprt->reestablish_timeout = 0;
3135         xprt->idle_timeout = 0;
3136
3137         xprt->ops = &bc_tcp_ops;
3138
3139         switch (addr->sa_family) {
3140         case AF_INET:
3141                 xs_format_peer_addresses(xprt, "tcp",
3142                                          RPCBIND_NETID_TCP);
3143                 break;
3144         case AF_INET6:
3145                 xs_format_peer_addresses(xprt, "tcp",
3146                                    RPCBIND_NETID_TCP6);
3147                 break;
3148         default:
3149                 ret = ERR_PTR(-EAFNOSUPPORT);
3150                 goto out_err;
3151         }
3152
3153         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3154                         xprt->address_strings[RPC_DISPLAY_ADDR],
3155                         xprt->address_strings[RPC_DISPLAY_PORT],
3156                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3157
3158         /*
3159          * Once we've associated a backchannel xprt with a connection,
3160          * we want to keep it around as long as the connection lasts,
3161          * in case we need to start using it for a backchannel again;
3162          * this reference won't be dropped until bc_xprt is destroyed.
3163          */
3164         xprt_get(xprt);
3165         args->bc_xprt->xpt_bc_xprt = xprt;
3166         xprt->bc_xprt = args->bc_xprt;
3167         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3168         transport->sock = bc_sock->sk_sock;
3169         transport->inet = bc_sock->sk_sk;
3170
3171         /*
3172          * Since we don't want connections for the backchannel, we set
3173          * the xprt status to connected
3174          */
3175         xprt_set_connected(xprt);
3176
3177         if (try_module_get(THIS_MODULE))
3178                 return xprt;
3179
3180         args->bc_xprt->xpt_bc_xprt = NULL;
3181         args->bc_xprt->xpt_bc_xps = NULL;
3182         xprt_put(xprt);
3183         ret = ERR_PTR(-EINVAL);
3184 out_err:
3185         xs_xprt_free(xprt);
3186         return ret;
3187 }
3188
3189 static struct xprt_class        xs_local_transport = {
3190         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3191         .name           = "named UNIX socket",
3192         .owner          = THIS_MODULE,
3193         .ident          = XPRT_TRANSPORT_LOCAL,
3194         .setup          = xs_setup_local,
3195 };
3196
3197 static struct xprt_class        xs_udp_transport = {
3198         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3199         .name           = "udp",
3200         .owner          = THIS_MODULE,
3201         .ident          = XPRT_TRANSPORT_UDP,
3202         .setup          = xs_setup_udp,
3203 };
3204
3205 static struct xprt_class        xs_tcp_transport = {
3206         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3207         .name           = "tcp",
3208         .owner          = THIS_MODULE,
3209         .ident          = XPRT_TRANSPORT_TCP,
3210         .setup          = xs_setup_tcp,
3211 };
3212
3213 static struct xprt_class        xs_bc_tcp_transport = {
3214         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3215         .name           = "tcp NFSv4.1 backchannel",
3216         .owner          = THIS_MODULE,
3217         .ident          = XPRT_TRANSPORT_BC_TCP,
3218         .setup          = xs_setup_bc_tcp,
3219 };
3220
3221 /**
3222  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3223  *
3224  */
3225 int init_socket_xprt(void)
3226 {
3227 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3228         if (!sunrpc_table_header)
3229                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3230 #endif
3231
3232         xprt_register_transport(&xs_local_transport);
3233         xprt_register_transport(&xs_udp_transport);
3234         xprt_register_transport(&xs_tcp_transport);
3235         xprt_register_transport(&xs_bc_tcp_transport);
3236
3237         return 0;
3238 }
3239
3240 /**
3241  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3242  *
3243  */
3244 void cleanup_socket_xprt(void)
3245 {
3246 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3247         if (sunrpc_table_header) {
3248                 unregister_sysctl_table(sunrpc_table_header);
3249                 sunrpc_table_header = NULL;
3250         }
3251 #endif
3252
3253         xprt_unregister_transport(&xs_local_transport);
3254         xprt_unregister_transport(&xs_udp_transport);
3255         xprt_unregister_transport(&xs_tcp_transport);
3256         xprt_unregister_transport(&xs_bc_tcp_transport);
3257 }
3258
3259 static int param_set_uint_minmax(const char *val,
3260                 const struct kernel_param *kp,
3261                 unsigned int min, unsigned int max)
3262 {
3263         unsigned int num;
3264         int ret;
3265
3266         if (!val)
3267                 return -EINVAL;
3268         ret = kstrtouint(val, 0, &num);
3269         if (ret)
3270                 return ret;
3271         if (num < min || num > max)
3272                 return -EINVAL;
3273         *((unsigned int *)kp->arg) = num;
3274         return 0;
3275 }
3276
3277 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3278 {
3279         if (kp->arg == &xprt_min_resvport)
3280                 return param_set_uint_minmax(val, kp,
3281                         RPC_MIN_RESVPORT,
3282                         xprt_max_resvport);
3283         return param_set_uint_minmax(val, kp,
3284                         xprt_min_resvport,
3285                         RPC_MAX_RESVPORT);
3286 }
3287
3288 static const struct kernel_param_ops param_ops_portnr = {
3289         .set = param_set_portnr,
3290         .get = param_get_uint,
3291 };
3292
3293 #define param_check_portnr(name, p) \
3294         __param_check(name, p, unsigned int);
3295
3296 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3297 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3298