~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sunrpc/xprtsock.c

Version: ~ [ linux-6.2-rc3 ] ~ [ linux-6.1.5 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.87 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.162 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.228 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.269 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.302 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * linux/net/sunrpc/xprtsock.c
  4  *
  5  * Client-side transport implementation for sockets.
  6  *
  7  * TCP callback races fixes (C) 1998 Red Hat
  8  * TCP send fixes (C) 1998 Red Hat
  9  * TCP NFS related read + write fixes
 10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
 11  *
 12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
 13  * Fix behaviour when socket buffer is full.
 14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
 15  *
 16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
 17  *
 18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
 19  *   <gilles.quillard@bull.net>
 20  */
 21 
 22 #include <linux/types.h>
 23 #include <linux/string.h>
 24 #include <linux/slab.h>
 25 #include <linux/module.h>
 26 #include <linux/capability.h>
 27 #include <linux/pagemap.h>
 28 #include <linux/errno.h>
 29 #include <linux/socket.h>
 30 #include <linux/in.h>
 31 #include <linux/net.h>
 32 #include <linux/mm.h>
 33 #include <linux/un.h>
 34 #include <linux/udp.h>
 35 #include <linux/tcp.h>
 36 #include <linux/sunrpc/clnt.h>
 37 #include <linux/sunrpc/addr.h>
 38 #include <linux/sunrpc/sched.h>
 39 #include <linux/sunrpc/svcsock.h>
 40 #include <linux/sunrpc/xprtsock.h>
 41 #include <linux/file.h>
 42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
 43 #include <linux/sunrpc/bc_xprt.h>
 44 #endif
 45 
 46 #include <net/sock.h>
 47 #include <net/checksum.h>
 48 #include <net/udp.h>
 49 #include <net/tcp.h>
 50 #include <linux/bvec.h>
 51 #include <linux/highmem.h>
 52 #include <linux/uio.h>
 53 #include <linux/sched/mm.h>
 54 
 55 #include <trace/events/sunrpc.h>
 56 
 57 #include "sunrpc.h"
 58 
 59 static void xs_close(struct rpc_xprt *xprt);
 60 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
 61                 struct socket *sock);
 62 
 63 /*
 64  * xprtsock tunables
 65  */
 66 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
 67 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
 68 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
 69 
 70 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
 71 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
 72 
 73 #define XS_TCP_LINGER_TO        (15U * HZ)
 74 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
 75 
 76 /*
 77  * We can register our own files under /proc/sys/sunrpc by
 78  * calling register_sysctl_table() again.  The files in that
 79  * directory become the union of all files registered there.
 80  *
 81  * We simply need to make sure that we don't collide with
 82  * someone else's file names!
 83  */
 84 
 85 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
 86 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
 87 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
 88 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
 89 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
 90 
 91 static struct ctl_table_header *sunrpc_table_header;
 92 
 93 /*
 94  * FIXME: changing the UDP slot table size should also resize the UDP
 95  *        socket buffers for existing UDP transports
 96  */
 97 static struct ctl_table xs_tunables_table[] = {
 98         {
 99                 .procname       = "udp_slot_table_entries",
100                 .data           = &xprt_udp_slot_table_entries,
101                 .maxlen         = sizeof(unsigned int),
102                 .mode           = 0644,
103                 .proc_handler   = proc_dointvec_minmax,
104                 .extra1         = &min_slot_table_size,
105                 .extra2         = &max_slot_table_size
106         },
107         {
108                 .procname       = "tcp_slot_table_entries",
109                 .data           = &xprt_tcp_slot_table_entries,
110                 .maxlen         = sizeof(unsigned int),
111                 .mode           = 0644,
112                 .proc_handler   = proc_dointvec_minmax,
113                 .extra1         = &min_slot_table_size,
114                 .extra2         = &max_slot_table_size
115         },
116         {
117                 .procname       = "tcp_max_slot_table_entries",
118                 .data           = &xprt_max_tcp_slot_table_entries,
119                 .maxlen         = sizeof(unsigned int),
120                 .mode           = 0644,
121                 .proc_handler   = proc_dointvec_minmax,
122                 .extra1         = &min_slot_table_size,
123                 .extra2         = &max_tcp_slot_table_limit
124         },
125         {
126                 .procname       = "min_resvport",
127                 .data           = &xprt_min_resvport,
128                 .maxlen         = sizeof(unsigned int),
129                 .mode           = 0644,
130                 .proc_handler   = proc_dointvec_minmax,
131                 .extra1         = &xprt_min_resvport_limit,
132                 .extra2         = &xprt_max_resvport_limit
133         },
134         {
135                 .procname       = "max_resvport",
136                 .data           = &xprt_max_resvport,
137                 .maxlen         = sizeof(unsigned int),
138                 .mode           = 0644,
139                 .proc_handler   = proc_dointvec_minmax,
140                 .extra1         = &xprt_min_resvport_limit,
141                 .extra2         = &xprt_max_resvport_limit
142         },
143         {
144                 .procname       = "tcp_fin_timeout",
145                 .data           = &xs_tcp_fin_timeout,
146                 .maxlen         = sizeof(xs_tcp_fin_timeout),
147                 .mode           = 0644,
148                 .proc_handler   = proc_dointvec_jiffies,
149         },
150         { },
151 };
152 
153 static struct ctl_table sunrpc_table[] = {
154         {
155                 .procname       = "sunrpc",
156                 .mode           = 0555,
157                 .child          = xs_tunables_table
158         },
159         { },
160 };
161 
162 /*
163  * Wait duration for a reply from the RPC portmapper.
164  */
165 #define XS_BIND_TO              (60U * HZ)
166 
167 /*
168  * Delay if a UDP socket connect error occurs.  This is most likely some
169  * kind of resource problem on the local host.
170  */
171 #define XS_UDP_REEST_TO         (2U * HZ)
172 
173 /*
174  * The reestablish timeout allows clients to delay for a bit before attempting
175  * to reconnect to a server that just dropped our connection.
176  *
177  * We implement an exponential backoff when trying to reestablish a TCP
178  * transport connection with the server.  Some servers like to drop a TCP
179  * connection when they are overworked, so we start with a short timeout and
180  * increase over time if the server is down or not responding.
181  */
182 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
183 
184 /*
185  * TCP idle timeout; client drops the transport socket if it is idle
186  * for this long.  Note that we also timeout UDP sockets to prevent
187  * holding port numbers when there is no RPC traffic.
188  */
189 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
190 
191 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
192 # undef  RPC_DEBUG_DATA
193 # define RPCDBG_FACILITY        RPCDBG_TRANS
194 #endif
195 
196 #ifdef RPC_DEBUG_DATA
197 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
198 {
199         u8 *buf = (u8 *) packet;
200         int j;
201 
202         dprintk("RPC:       %s\n", msg);
203         for (j = 0; j < count && j < 128; j += 4) {
204                 if (!(j & 31)) {
205                         if (j)
206                                 dprintk("\n");
207                         dprintk("0x%04x ", j);
208                 }
209                 dprintk("%02x%02x%02x%02x ",
210                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
211         }
212         dprintk("\n");
213 }
214 #else
215 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
216 {
217         /* NOP */
218 }
219 #endif
220 
221 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
222 {
223         return (struct rpc_xprt *) sk->sk_user_data;
224 }
225 
226 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
227 {
228         return (struct sockaddr *) &xprt->addr;
229 }
230 
231 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
232 {
233         return (struct sockaddr_un *) &xprt->addr;
234 }
235 
236 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
237 {
238         return (struct sockaddr_in *) &xprt->addr;
239 }
240 
241 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
242 {
243         return (struct sockaddr_in6 *) &xprt->addr;
244 }
245 
246 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
247 {
248         struct sockaddr *sap = xs_addr(xprt);
249         struct sockaddr_in6 *sin6;
250         struct sockaddr_in *sin;
251         struct sockaddr_un *sun;
252         char buf[128];
253 
254         switch (sap->sa_family) {
255         case AF_LOCAL:
256                 sun = xs_addr_un(xprt);
257                 strlcpy(buf, sun->sun_path, sizeof(buf));
258                 xprt->address_strings[RPC_DISPLAY_ADDR] =
259                                                 kstrdup(buf, GFP_KERNEL);
260                 break;
261         case AF_INET:
262                 (void)rpc_ntop(sap, buf, sizeof(buf));
263                 xprt->address_strings[RPC_DISPLAY_ADDR] =
264                                                 kstrdup(buf, GFP_KERNEL);
265                 sin = xs_addr_in(xprt);
266                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
267                 break;
268         case AF_INET6:
269                 (void)rpc_ntop(sap, buf, sizeof(buf));
270                 xprt->address_strings[RPC_DISPLAY_ADDR] =
271                                                 kstrdup(buf, GFP_KERNEL);
272                 sin6 = xs_addr_in6(xprt);
273                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
274                 break;
275         default:
276                 BUG();
277         }
278 
279         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
280 }
281 
282 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
283 {
284         struct sockaddr *sap = xs_addr(xprt);
285         char buf[128];
286 
287         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
288         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
289 
290         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
291         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
292 }
293 
294 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
295                                      const char *protocol,
296                                      const char *netid)
297 {
298         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
299         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
300         xs_format_common_peer_addresses(xprt);
301         xs_format_common_peer_ports(xprt);
302 }
303 
304 static void xs_update_peer_port(struct rpc_xprt *xprt)
305 {
306         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
307         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
308 
309         xs_format_common_peer_ports(xprt);
310 }
311 
312 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
313 {
314         unsigned int i;
315 
316         for (i = 0; i < RPC_DISPLAY_MAX; i++)
317                 switch (i) {
318                 case RPC_DISPLAY_PROTO:
319                 case RPC_DISPLAY_NETID:
320                         continue;
321                 default:
322                         kfree(xprt->address_strings[i]);
323                 }
324 }
325 
326 static size_t
327 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
328 {
329         size_t i,n;
330 
331         if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
332                 return want;
333         n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
334         for (i = 0; i < n; i++) {
335                 if (buf->pages[i])
336                         continue;
337                 buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
338                 if (!buf->pages[i]) {
339                         i *= PAGE_SIZE;
340                         return i > buf->page_base ? i - buf->page_base : 0;
341                 }
342         }
343         return want;
344 }
345 
346 static ssize_t
347 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
348 {
349         ssize_t ret;
350         if (seek != 0)
351                 iov_iter_advance(&msg->msg_iter, seek);
352         ret = sock_recvmsg(sock, msg, flags);
353         return ret > 0 ? ret + seek : ret;
354 }
355 
356 static ssize_t
357 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
358                 struct kvec *kvec, size_t count, size_t seek)
359 {
360         iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
361         return xs_sock_recvmsg(sock, msg, flags, seek);
362 }
363 
364 static ssize_t
365 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
366                 struct bio_vec *bvec, unsigned long nr, size_t count,
367                 size_t seek)
368 {
369         iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
370         return xs_sock_recvmsg(sock, msg, flags, seek);
371 }
372 
373 static ssize_t
374 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
375                 size_t count)
376 {
377         iov_iter_discard(&msg->msg_iter, READ, count);
378         return sock_recvmsg(sock, msg, flags);
379 }
380 
381 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
382 static void
383 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
384 {
385         struct bvec_iter bi = {
386                 .bi_size = count,
387         };
388         struct bio_vec bv;
389 
390         bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
391         for_each_bvec(bv, bvec, bi, bi)
392                 flush_dcache_page(bv.bv_page);
393 }
394 #else
395 static inline void
396 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
397 {
398 }
399 #endif
400 
401 static ssize_t
402 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
403                 struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
404 {
405         size_t want, seek_init = seek, offset = 0;
406         ssize_t ret;
407 
408         want = min_t(size_t, count, buf->head[0].iov_len);
409         if (seek < want) {
410                 ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
411                 if (ret <= 0)
412                         goto sock_err;
413                 offset += ret;
414                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
415                         goto out;
416                 if (ret != want)
417                         goto out;
418                 seek = 0;
419         } else {
420                 seek -= want;
421                 offset += want;
422         }
423 
424         want = xs_alloc_sparse_pages(buf,
425                         min_t(size_t, count - offset, buf->page_len),
426                         GFP_KERNEL);
427         if (seek < want) {
428                 ret = xs_read_bvec(sock, msg, flags, buf->bvec,
429                                 xdr_buf_pagecount(buf),
430                                 want + buf->page_base,
431                                 seek + buf->page_base);
432                 if (ret <= 0)
433                         goto sock_err;
434                 xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
435                 offset += ret - buf->page_base;
436                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
437                         goto out;
438                 if (ret != want)
439                         goto out;
440                 seek = 0;
441         } else {
442                 seek -= want;
443                 offset += want;
444         }
445 
446         want = min_t(size_t, count - offset, buf->tail[0].iov_len);
447         if (seek < want) {
448                 ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
449                 if (ret <= 0)
450                         goto sock_err;
451                 offset += ret;
452                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
453                         goto out;
454                 if (ret != want)
455                         goto out;
456         } else if (offset < seek_init)
457                 offset = seek_init;
458         ret = -EMSGSIZE;
459 out:
460         *read = offset - seek_init;
461         return ret;
462 sock_err:
463         offset += seek;
464         goto out;
465 }
466 
467 static void
468 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
469 {
470         if (!transport->recv.copied) {
471                 if (buf->head[0].iov_len >= transport->recv.offset)
472                         memcpy(buf->head[0].iov_base,
473                                         &transport->recv.xid,
474                                         transport->recv.offset);
475                 transport->recv.copied = transport->recv.offset;
476         }
477 }
478 
479 static bool
480 xs_read_stream_request_done(struct sock_xprt *transport)
481 {
482         return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
483 }
484 
485 static void
486 xs_read_stream_check_eor(struct sock_xprt *transport,
487                 struct msghdr *msg)
488 {
489         if (xs_read_stream_request_done(transport))
490                 msg->msg_flags |= MSG_EOR;
491 }
492 
493 static ssize_t
494 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
495                 int flags, struct rpc_rqst *req)
496 {
497         struct xdr_buf *buf = &req->rq_private_buf;
498         size_t want, uninitialized_var(read);
499         ssize_t uninitialized_var(ret);
500 
501         xs_read_header(transport, buf);
502 
503         want = transport->recv.len - transport->recv.offset;
504         if (want != 0) {
505                 ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
506                                 transport->recv.copied + want,
507                                 transport->recv.copied,
508                                 &read);
509                 transport->recv.offset += read;
510                 transport->recv.copied += read;
511         }
512 
513         if (transport->recv.offset == transport->recv.len)
514                 xs_read_stream_check_eor(transport, msg);
515 
516         if (want == 0)
517                 return 0;
518 
519         switch (ret) {
520         default:
521                 break;
522         case -EFAULT:
523         case -EMSGSIZE:
524                 msg->msg_flags |= MSG_TRUNC;
525                 return read;
526         case 0:
527                 return -ESHUTDOWN;
528         }
529         return ret < 0 ? ret : read;
530 }
531 
532 static size_t
533 xs_read_stream_headersize(bool isfrag)
534 {
535         if (isfrag)
536                 return sizeof(__be32);
537         return 3 * sizeof(__be32);
538 }
539 
540 static ssize_t
541 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
542                 int flags, size_t want, size_t seek)
543 {
544         struct kvec kvec = {
545                 .iov_base = &transport->recv.fraghdr,
546                 .iov_len = want,
547         };
548         return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
549 }
550 
551 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
552 static ssize_t
553 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
554 {
555         struct rpc_xprt *xprt = &transport->xprt;
556         struct rpc_rqst *req;
557         ssize_t ret;
558 
559         /* Look up and lock the request corresponding to the given XID */
560         req = xprt_lookup_bc_request(xprt, transport->recv.xid);
561         if (!req) {
562                 printk(KERN_WARNING "Callback slot table overflowed\n");
563                 return -ESHUTDOWN;
564         }
565         if (transport->recv.copied && !req->rq_private_buf.len)
566                 return -ESHUTDOWN;
567 
568         ret = xs_read_stream_request(transport, msg, flags, req);
569         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
570                 xprt_complete_bc_request(req, transport->recv.copied);
571         else
572                 req->rq_private_buf.len = transport->recv.copied;
573 
574         return ret;
575 }
576 #else /* CONFIG_SUNRPC_BACKCHANNEL */
577 static ssize_t
578 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
579 {
580         return -ESHUTDOWN;
581 }
582 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
583 
584 static ssize_t
585 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
586 {
587         struct rpc_xprt *xprt = &transport->xprt;
588         struct rpc_rqst *req;
589         ssize_t ret = 0;
590 
591         /* Look up and lock the request corresponding to the given XID */
592         spin_lock(&xprt->queue_lock);
593         req = xprt_lookup_rqst(xprt, transport->recv.xid);
594         if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
595                 msg->msg_flags |= MSG_TRUNC;
596                 goto out;
597         }
598         xprt_pin_rqst(req);
599         spin_unlock(&xprt->queue_lock);
600 
601         ret = xs_read_stream_request(transport, msg, flags, req);
602 
603         spin_lock(&xprt->queue_lock);
604         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
605                 xprt_complete_rqst(req->rq_task, transport->recv.copied);
606         else
607                 req->rq_private_buf.len = transport->recv.copied;
608         xprt_unpin_rqst(req);
609 out:
610         spin_unlock(&xprt->queue_lock);
611         return ret;
612 }
613 
614 static ssize_t
615 xs_read_stream(struct sock_xprt *transport, int flags)
616 {
617         struct msghdr msg = { 0 };
618         size_t want, read = 0;
619         ssize_t ret = 0;
620 
621         if (transport->recv.len == 0) {
622                 want = xs_read_stream_headersize(transport->recv.copied != 0);
623                 ret = xs_read_stream_header(transport, &msg, flags, want,
624                                 transport->recv.offset);
625                 if (ret <= 0)
626                         goto out_err;
627                 transport->recv.offset = ret;
628                 if (transport->recv.offset != want)
629                         return transport->recv.offset;
630                 transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
631                         RPC_FRAGMENT_SIZE_MASK;
632                 transport->recv.offset -= sizeof(transport->recv.fraghdr);
633                 read = ret;
634         }
635 
636         switch (be32_to_cpu(transport->recv.calldir)) {
637         default:
638                 msg.msg_flags |= MSG_TRUNC;
639                 break;
640         case RPC_CALL:
641                 ret = xs_read_stream_call(transport, &msg, flags);
642                 break;
643         case RPC_REPLY:
644                 ret = xs_read_stream_reply(transport, &msg, flags);
645         }
646         if (msg.msg_flags & MSG_TRUNC) {
647                 transport->recv.calldir = cpu_to_be32(-1);
648                 transport->recv.copied = -1;
649         }
650         if (ret < 0)
651                 goto out_err;
652         read += ret;
653         if (transport->recv.offset < transport->recv.len) {
654                 if (!(msg.msg_flags & MSG_TRUNC))
655                         return read;
656                 msg.msg_flags = 0;
657                 ret = xs_read_discard(transport->sock, &msg, flags,
658                                 transport->recv.len - transport->recv.offset);
659                 if (ret <= 0)
660                         goto out_err;
661                 transport->recv.offset += ret;
662                 read += ret;
663                 if (transport->recv.offset != transport->recv.len)
664                         return read;
665         }
666         if (xs_read_stream_request_done(transport)) {
667                 trace_xs_stream_read_request(transport);
668                 transport->recv.copied = 0;
669         }
670         transport->recv.offset = 0;
671         transport->recv.len = 0;
672         return read;
673 out_err:
674         return ret != 0 ? ret : -ESHUTDOWN;
675 }
676 
677 static __poll_t xs_poll_socket(struct sock_xprt *transport)
678 {
679         return transport->sock->ops->poll(transport->file, transport->sock,
680                         NULL);
681 }
682 
683 static bool xs_poll_socket_readable(struct sock_xprt *transport)
684 {
685         __poll_t events = xs_poll_socket(transport);
686 
687         return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
688 }
689 
690 static void xs_poll_check_readable(struct sock_xprt *transport)
691 {
692 
693         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
694         if (!xs_poll_socket_readable(transport))
695                 return;
696         if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
697                 queue_work(xprtiod_workqueue, &transport->recv_worker);
698 }
699 
700 static void xs_stream_data_receive(struct sock_xprt *transport)
701 {
702         size_t read = 0;
703         ssize_t ret = 0;
704 
705         mutex_lock(&transport->recv_mutex);
706         if (transport->sock == NULL)
707                 goto out;
708         for (;;) {
709                 ret = xs_read_stream(transport, MSG_DONTWAIT);
710                 if (ret < 0)
711                         break;
712                 read += ret;
713                 cond_resched();
714         }
715         if (ret == -ESHUTDOWN)
716                 kernel_sock_shutdown(transport->sock, SHUT_RDWR);
717         else
718                 xs_poll_check_readable(transport);
719 out:
720         mutex_unlock(&transport->recv_mutex);
721         trace_xs_stream_read_data(&transport->xprt, ret, read);
722 }
723 
724 static void xs_stream_data_receive_workfn(struct work_struct *work)
725 {
726         struct sock_xprt *transport =
727                 container_of(work, struct sock_xprt, recv_worker);
728         unsigned int pflags = memalloc_nofs_save();
729 
730         xs_stream_data_receive(transport);
731         memalloc_nofs_restore(pflags);
732 }
733 
734 static void
735 xs_stream_reset_connect(struct sock_xprt *transport)
736 {
737         transport->recv.offset = 0;
738         transport->recv.len = 0;
739         transport->recv.copied = 0;
740         transport->xmit.offset = 0;
741 }
742 
743 static void
744 xs_stream_start_connect(struct sock_xprt *transport)
745 {
746         transport->xprt.stat.connect_count++;
747         transport->xprt.stat.connect_start = jiffies;
748 }
749 
750 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
751 
752 static int xs_sendmsg(struct socket *sock, struct msghdr *msg, size_t seek)
753 {
754         if (seek)
755                 iov_iter_advance(&msg->msg_iter, seek);
756         return sock_sendmsg(sock, msg);
757 }
758 
759 static int xs_send_kvec(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t seek)
760 {
761         iov_iter_kvec(&msg->msg_iter, WRITE, vec, 1, vec->iov_len);
762         return xs_sendmsg(sock, msg, seek);
763 }
764 
765 static int xs_send_pagedata(struct socket *sock, struct msghdr *msg, struct xdr_buf *xdr, size_t base)
766 {
767         int err;
768 
769         err = xdr_alloc_bvec(xdr, GFP_KERNEL);
770         if (err < 0)
771                 return err;
772 
773         iov_iter_bvec(&msg->msg_iter, WRITE, xdr->bvec,
774                         xdr_buf_pagecount(xdr),
775                         xdr->page_len + xdr->page_base);
776         return xs_sendmsg(sock, msg, base + xdr->page_base);
777 }
778 
779 #define xs_record_marker_len() sizeof(rpc_fraghdr)
780 
781 /* Common case:
782  *  - stream transport
783  *  - sending from byte 0 of the message
784  *  - the message is wholly contained in @xdr's head iovec
785  */
786 static int xs_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
787                 rpc_fraghdr marker, struct kvec *vec, size_t base)
788 {
789         struct kvec iov[2] = {
790                 [0] = {
791                         .iov_base       = &marker,
792                         .iov_len        = sizeof(marker)
793                 },
794                 [1] = *vec,
795         };
796         size_t len = iov[0].iov_len + iov[1].iov_len;
797 
798         iov_iter_kvec(&msg->msg_iter, WRITE, iov, 2, len);
799         return xs_sendmsg(sock, msg, base);
800 }
801 
802 /**
803  * xs_sendpages - write pages directly to a socket
804  * @sock: socket to send on
805  * @addr: UDP only -- address of destination
806  * @addrlen: UDP only -- length of destination address
807  * @xdr: buffer containing this request
808  * @base: starting position in the buffer
809  * @rm: stream record marker field
810  * @sent_p: return the total number of bytes successfully queued for sending
811  *
812  */
813 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, rpc_fraghdr rm, int *sent_p)
814 {
815         struct msghdr msg = {
816                 .msg_name = addr,
817                 .msg_namelen = addrlen,
818                 .msg_flags = XS_SENDMSG_FLAGS | MSG_MORE,
819         };
820         unsigned int rmsize = rm ? sizeof(rm) : 0;
821         unsigned int remainder = rmsize + xdr->len - base;
822         unsigned int want;
823         int err = 0;
824 
825         if (unlikely(!sock))
826                 return -ENOTSOCK;
827 
828         want = xdr->head[0].iov_len + rmsize;
829         if (base < want) {
830                 unsigned int len = want - base;
831                 remainder -= len;
832                 if (remainder == 0)
833                         msg.msg_flags &= ~MSG_MORE;
834                 if (rmsize)
835                         err = xs_send_rm_and_kvec(sock, &msg, rm,
836                                         &xdr->head[0], base);
837                 else
838                         err = xs_send_kvec(sock, &msg, &xdr->head[0], base);
839                 if (remainder == 0 || err != len)
840                         goto out;
841                 *sent_p += err;
842                 base = 0;
843         } else
844                 base -= want;
845 
846         if (base < xdr->page_len) {
847                 unsigned int len = xdr->page_len - base;
848                 remainder -= len;
849                 if (remainder == 0)
850                         msg.msg_flags &= ~MSG_MORE;
851                 err = xs_send_pagedata(sock, &msg, xdr, base);
852                 if (remainder == 0 || err != len)
853                         goto out;
854                 *sent_p += err;
855                 base = 0;
856         } else
857                 base -= xdr->page_len;
858 
859         if (base >= xdr->tail[0].iov_len)
860                 return 0;
861         msg.msg_flags &= ~MSG_MORE;
862         err = xs_send_kvec(sock, &msg, &xdr->tail[0], base);
863 out:
864         if (err > 0) {
865                 *sent_p += err;
866                 err = 0;
867         }
868         return err;
869 }
870 
871 /**
872  * xs_nospace - handle transmit was incomplete
873  * @req: pointer to RPC request
874  *
875  */
876 static int xs_nospace(struct rpc_rqst *req)
877 {
878         struct rpc_xprt *xprt = req->rq_xprt;
879         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
880         struct sock *sk = transport->inet;
881         int ret = -EAGAIN;
882 
883         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
884                         req->rq_task->tk_pid,
885                         req->rq_slen - transport->xmit.offset,
886                         req->rq_slen);
887 
888         /* Protect against races with write_space */
889         spin_lock(&xprt->transport_lock);
890 
891         /* Don't race with disconnect */
892         if (xprt_connected(xprt)) {
893                 /* wait for more buffer space */
894                 sk->sk_write_pending++;
895                 xprt_wait_for_buffer_space(xprt);
896         } else
897                 ret = -ENOTCONN;
898 
899         spin_unlock(&xprt->transport_lock);
900 
901         /* Race breaker in case memory is freed before above code is called */
902         if (ret == -EAGAIN) {
903                 struct socket_wq *wq;
904 
905                 rcu_read_lock();
906                 wq = rcu_dereference(sk->sk_wq);
907                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
908                 rcu_read_unlock();
909 
910                 sk->sk_write_space(sk);
911         }
912         return ret;
913 }
914 
915 static void
916 xs_stream_prepare_request(struct rpc_rqst *req)
917 {
918         xdr_free_bvec(&req->rq_rcv_buf);
919         req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
920 }
921 
922 /*
923  * Determine if the previous message in the stream was aborted before it
924  * could complete transmission.
925  */
926 static bool
927 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
928 {
929         return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
930 }
931 
932 /*
933  * Return the stream record marker field for a record of length < 2^31-1
934  */
935 static rpc_fraghdr
936 xs_stream_record_marker(struct xdr_buf *xdr)
937 {
938         if (!xdr->len)
939                 return 0;
940         return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
941 }
942 
943 /**
944  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
945  * @req: pointer to RPC request
946  *
947  * Return values:
948  *        0:    The request has been sent
949  *   EAGAIN:    The socket was blocked, please call again later to
950  *              complete the request
951  * ENOTCONN:    Caller needs to invoke connect logic then call again
952  *    other:    Some other error occured, the request was not sent
953  */
954 static int xs_local_send_request(struct rpc_rqst *req)
955 {
956         struct rpc_xprt *xprt = req->rq_xprt;
957         struct sock_xprt *transport =
958                                 container_of(xprt, struct sock_xprt, xprt);
959         struct xdr_buf *xdr = &req->rq_snd_buf;
960         rpc_fraghdr rm = xs_stream_record_marker(xdr);
961         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
962         int status;
963         int sent = 0;
964 
965         /* Close the stream if the previous transmission was incomplete */
966         if (xs_send_request_was_aborted(transport, req)) {
967                 xs_close(xprt);
968                 return -ENOTCONN;
969         }
970 
971         xs_pktdump("packet data:",
972                         req->rq_svec->iov_base, req->rq_svec->iov_len);
973 
974         req->rq_xtime = ktime_get();
975         status = xs_sendpages(transport->sock, NULL, 0, xdr,
976                               transport->xmit.offset, rm, &sent);
977         dprintk("RPC:       %s(%u) = %d\n",
978                         __func__, xdr->len - transport->xmit.offset, status);
979 
980         if (status == -EAGAIN && sock_writeable(transport->inet))
981                 status = -ENOBUFS;
982 
983         if (likely(sent > 0) || status == 0) {
984                 transport->xmit.offset += sent;
985                 req->rq_bytes_sent = transport->xmit.offset;
986                 if (likely(req->rq_bytes_sent >= msglen)) {
987                         req->rq_xmit_bytes_sent += transport->xmit.offset;
988                         transport->xmit.offset = 0;
989                         return 0;
990                 }
991                 status = -EAGAIN;
992         }
993 
994         switch (status) {
995         case -ENOBUFS:
996                 break;
997         case -EAGAIN:
998                 status = xs_nospace(req);
999                 break;
1000         default:
1001                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1002                         -status);
1003                 /* fall through */
1004         case -EPIPE:
1005                 xs_close(xprt);
1006                 status = -ENOTCONN;
1007         }
1008 
1009         return status;
1010 }
1011 
1012 /**
1013  * xs_udp_send_request - write an RPC request to a UDP socket
1014  * @req: pointer to RPC request
1015  *
1016  * Return values:
1017  *        0:    The request has been sent
1018  *   EAGAIN:    The socket was blocked, please call again later to
1019  *              complete the request
1020  * ENOTCONN:    Caller needs to invoke connect logic then call again
1021  *    other:    Some other error occurred, the request was not sent
1022  */
1023 static int xs_udp_send_request(struct rpc_rqst *req)
1024 {
1025         struct rpc_xprt *xprt = req->rq_xprt;
1026         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1027         struct xdr_buf *xdr = &req->rq_snd_buf;
1028         int sent = 0;
1029         int status;
1030 
1031         xs_pktdump("packet data:",
1032                                 req->rq_svec->iov_base,
1033                                 req->rq_svec->iov_len);
1034 
1035         if (!xprt_bound(xprt))
1036                 return -ENOTCONN;
1037 
1038         if (!xprt_request_get_cong(xprt, req))
1039                 return -EBADSLT;
1040 
1041         req->rq_xtime = ktime_get();
1042         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
1043                               xdr, 0, 0, &sent);
1044 
1045         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
1046                         xdr->len, status);
1047 
1048         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
1049         if (status == -EPERM)
1050                 goto process_status;
1051 
1052         if (status == -EAGAIN && sock_writeable(transport->inet))
1053                 status = -ENOBUFS;
1054 
1055         if (sent > 0 || status == 0) {
1056                 req->rq_xmit_bytes_sent += sent;
1057                 if (sent >= req->rq_slen)
1058                         return 0;
1059                 /* Still some bytes left; set up for a retry later. */
1060                 status = -EAGAIN;
1061         }
1062 
1063 process_status:
1064         switch (status) {
1065         case -ENOTSOCK:
1066                 status = -ENOTCONN;
1067                 /* Should we call xs_close() here? */
1068                 break;
1069         case -EAGAIN:
1070                 status = xs_nospace(req);
1071                 break;
1072         case -ENETUNREACH:
1073         case -ENOBUFS:
1074         case -EPIPE:
1075         case -ECONNREFUSED:
1076         case -EPERM:
1077                 /* When the server has died, an ICMP port unreachable message
1078                  * prompts ECONNREFUSED. */
1079                 break;
1080         default:
1081                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1082                         -status);
1083         }
1084 
1085         return status;
1086 }
1087 
1088 /**
1089  * xs_tcp_send_request - write an RPC request to a TCP socket
1090  * @req: pointer to RPC request
1091  *
1092  * Return values:
1093  *        0:    The request has been sent
1094  *   EAGAIN:    The socket was blocked, please call again later to
1095  *              complete the request
1096  * ENOTCONN:    Caller needs to invoke connect logic then call again
1097  *    other:    Some other error occurred, the request was not sent
1098  *
1099  * XXX: In the case of soft timeouts, should we eventually give up
1100  *      if sendmsg is not able to make progress?
1101  */
1102 static int xs_tcp_send_request(struct rpc_rqst *req)
1103 {
1104         struct rpc_xprt *xprt = req->rq_xprt;
1105         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1106         struct xdr_buf *xdr = &req->rq_snd_buf;
1107         rpc_fraghdr rm = xs_stream_record_marker(xdr);
1108         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1109         bool vm_wait = false;
1110         int status;
1111         int sent;
1112 
1113         /* Close the stream if the previous transmission was incomplete */
1114         if (xs_send_request_was_aborted(transport, req)) {
1115                 if (transport->sock != NULL)
1116                         kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1117                 return -ENOTCONN;
1118         }
1119 
1120         xs_pktdump("packet data:",
1121                                 req->rq_svec->iov_base,
1122                                 req->rq_svec->iov_len);
1123 
1124         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1125                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
1126 
1127         /* Continue transmitting the packet/record. We must be careful
1128          * to cope with writespace callbacks arriving _after_ we have
1129          * called sendmsg(). */
1130         req->rq_xtime = ktime_get();
1131         while (1) {
1132                 sent = 0;
1133                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
1134                                       transport->xmit.offset, rm, &sent);
1135 
1136                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1137                                 xdr->len - transport->xmit.offset, status);
1138 
1139                 /* If we've sent the entire packet, immediately
1140                  * reset the count of bytes sent. */
1141                 transport->xmit.offset += sent;
1142                 req->rq_bytes_sent = transport->xmit.offset;
1143                 if (likely(req->rq_bytes_sent >= msglen)) {
1144                         req->rq_xmit_bytes_sent += transport->xmit.offset;
1145                         transport->xmit.offset = 0;
1146                         return 0;
1147                 }
1148 
1149                 WARN_ON_ONCE(sent == 0 && status == 0);
1150 
1151                 if (status == -EAGAIN ) {
1152                         /*
1153                          * Return EAGAIN if we're sure we're hitting the
1154                          * socket send buffer limits.
1155                          */
1156                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1157                                 break;
1158                         /*
1159                          * Did we hit a memory allocation failure?
1160                          */
1161                         if (sent == 0) {
1162                                 status = -ENOBUFS;
1163                                 if (vm_wait)
1164                                         break;
1165                                 /* Retry, knowing now that we're below the
1166                                  * socket send buffer limit
1167                                  */
1168                                 vm_wait = true;
1169                         }
1170                         continue;
1171                 }
1172                 if (status < 0)
1173                         break;
1174                 vm_wait = false;
1175         }
1176 
1177         switch (status) {
1178         case -ENOTSOCK:
1179                 status = -ENOTCONN;
1180                 /* Should we call xs_close() here? */
1181                 break;
1182         case -EAGAIN:
1183                 status = xs_nospace(req);
1184                 break;
1185         case -ECONNRESET:
1186         case -ECONNREFUSED:
1187         case -ENOTCONN:
1188         case -EADDRINUSE:
1189         case -ENOBUFS:
1190         case -EPIPE:
1191                 break;
1192         default:
1193                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1194                         -status);
1195         }
1196 
1197         return status;
1198 }
1199 
1200 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1201 {
1202         transport->old_data_ready = sk->sk_data_ready;
1203         transport->old_state_change = sk->sk_state_change;
1204         transport->old_write_space = sk->sk_write_space;
1205         transport->old_error_report = sk->sk_error_report;
1206 }
1207 
1208 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1209 {
1210         sk->sk_data_ready = transport->old_data_ready;
1211         sk->sk_state_change = transport->old_state_change;
1212         sk->sk_write_space = transport->old_write_space;
1213         sk->sk_error_report = transport->old_error_report;
1214 }
1215 
1216 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1217 {
1218         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1219 
1220         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1221         clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1222         clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1223         clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1224 }
1225 
1226 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1227 {
1228         set_bit(nr, &transport->sock_state);
1229         queue_work(xprtiod_workqueue, &transport->error_worker);
1230 }
1231 
1232 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1233 {
1234         smp_mb__before_atomic();
1235         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1236         clear_bit(XPRT_CLOSING, &xprt->state);
1237         xs_sock_reset_state_flags(xprt);
1238         smp_mb__after_atomic();
1239 }
1240 
1241 /**
1242  * xs_error_report - callback to handle TCP socket state errors
1243  * @sk: socket
1244  *
1245  * Note: we don't call sock_error() since there may be a rpc_task
1246  * using the socket, and so we don't want to clear sk->sk_err.
1247  */
1248 static void xs_error_report(struct sock *sk)
1249 {
1250         struct sock_xprt *transport;
1251         struct rpc_xprt *xprt;
1252 
1253         read_lock_bh(&sk->sk_callback_lock);
1254         if (!(xprt = xprt_from_sock(sk)))
1255                 goto out;
1256 
1257         transport = container_of(xprt, struct sock_xprt, xprt);
1258         transport->xprt_err = -sk->sk_err;
1259         if (transport->xprt_err == 0)
1260                 goto out;
1261         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1262                         xprt, -transport->xprt_err);
1263         trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1264 
1265         /* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1266         smp_mb__before_atomic();
1267         xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1268  out:
1269         read_unlock_bh(&sk->sk_callback_lock);
1270 }
1271 
1272 static void xs_reset_transport(struct sock_xprt *transport)
1273 {
1274         struct socket *sock = transport->sock;
1275         struct sock *sk = transport->inet;
1276         struct rpc_xprt *xprt = &transport->xprt;
1277         struct file *filp = transport->file;
1278 
1279         if (sk == NULL)
1280                 return;
1281 
1282         if (atomic_read(&transport->xprt.swapper))
1283                 sk_clear_memalloc(sk);
1284 
1285         kernel_sock_shutdown(sock, SHUT_RDWR);
1286 
1287         mutex_lock(&transport->recv_mutex);
1288         write_lock_bh(&sk->sk_callback_lock);
1289         transport->inet = NULL;
1290         transport->sock = NULL;
1291         transport->file = NULL;
1292 
1293         sk->sk_user_data = NULL;
1294 
1295         xs_restore_old_callbacks(transport, sk);
1296         xprt_clear_connected(xprt);
1297         write_unlock_bh(&sk->sk_callback_lock);
1298         xs_sock_reset_connection_flags(xprt);
1299         /* Reset stream record info */
1300         xs_stream_reset_connect(transport);
1301         mutex_unlock(&transport->recv_mutex);
1302 
1303         trace_rpc_socket_close(xprt, sock);
1304         fput(filp);
1305 
1306         xprt_disconnect_done(xprt);
1307 }
1308 
1309 /**
1310  * xs_close - close a socket
1311  * @xprt: transport
1312  *
1313  * This is used when all requests are complete; ie, no DRC state remains
1314  * on the server we want to save.
1315  *
1316  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1317  * xs_reset_transport() zeroing the socket from underneath a writer.
1318  */
1319 static void xs_close(struct rpc_xprt *xprt)
1320 {
1321         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1322 
1323         dprintk("RPC:       xs_close xprt %p\n", xprt);
1324 
1325         xs_reset_transport(transport);
1326         xprt->reestablish_timeout = 0;
1327 }
1328 
1329 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1330 {
1331         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1332                 xprt);
1333         xprt_disconnect_done(xprt);
1334 }
1335 
1336 static void xs_xprt_free(struct rpc_xprt *xprt)
1337 {
1338         xs_free_peer_addresses(xprt);
1339         xprt_free(xprt);
1340 }
1341 
1342 /**
1343  * xs_destroy - prepare to shutdown a transport
1344  * @xprt: doomed transport
1345  *
1346  */
1347 static void xs_destroy(struct rpc_xprt *xprt)
1348 {
1349         struct sock_xprt *transport = container_of(xprt,
1350                         struct sock_xprt, xprt);
1351         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1352 
1353         cancel_delayed_work_sync(&transport->connect_worker);
1354         xs_close(xprt);
1355         cancel_work_sync(&transport->recv_worker);
1356         cancel_work_sync(&transport->error_worker);
1357         xs_xprt_free(xprt);
1358         module_put(THIS_MODULE);
1359 }
1360 
1361 /**
1362  * xs_udp_data_read_skb - receive callback for UDP sockets
1363  * @xprt: transport
1364  * @sk: socket
1365  * @skb: skbuff
1366  *
1367  */
1368 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1369                 struct sock *sk,
1370                 struct sk_buff *skb)
1371 {
1372         struct rpc_task *task;
1373         struct rpc_rqst *rovr;
1374         int repsize, copied;
1375         u32 _xid;
1376         __be32 *xp;
1377 
1378         repsize = skb->len;
1379         if (repsize < 4) {
1380                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1381                 return;
1382         }
1383 
1384         /* Copy the XID from the skb... */
1385         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1386         if (xp == NULL)
1387                 return;
1388 
1389         /* Look up and lock the request corresponding to the given XID */
1390         spin_lock(&xprt->queue_lock);
1391         rovr = xprt_lookup_rqst(xprt, *xp);
1392         if (!rovr)
1393                 goto out_unlock;
1394         xprt_pin_rqst(rovr);
1395         xprt_update_rtt(rovr->rq_task);
1396         spin_unlock(&xprt->queue_lock);
1397         task = rovr->rq_task;
1398 
1399         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1400                 copied = repsize;
1401 
1402         /* Suck it into the iovec, verify checksum if not done by hw. */
1403         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1404                 spin_lock(&xprt->queue_lock);
1405                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1406                 goto out_unpin;
1407         }
1408 
1409 
1410         spin_lock(&xprt->transport_lock);
1411         xprt_adjust_cwnd(xprt, task, copied);
1412         spin_unlock(&xprt->transport_lock);
1413         spin_lock(&xprt->queue_lock);
1414         xprt_complete_rqst(task, copied);
1415         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1416 out_unpin:
1417         xprt_unpin_rqst(rovr);
1418  out_unlock:
1419         spin_unlock(&xprt->queue_lock);
1420 }
1421 
1422 static void xs_udp_data_receive(struct sock_xprt *transport)
1423 {
1424         struct sk_buff *skb;
1425         struct sock *sk;
1426         int err;
1427 
1428         mutex_lock(&transport->recv_mutex);
1429         sk = transport->inet;
1430         if (sk == NULL)
1431                 goto out;
1432         for (;;) {
1433                 skb = skb_recv_udp(sk, 0, 1, &err);
1434                 if (skb == NULL)
1435                         break;
1436                 xs_udp_data_read_skb(&transport->xprt, sk, skb);
1437                 consume_skb(skb);
1438                 cond_resched();
1439         }
1440         xs_poll_check_readable(transport);
1441 out:
1442         mutex_unlock(&transport->recv_mutex);
1443 }
1444 
1445 static void xs_udp_data_receive_workfn(struct work_struct *work)
1446 {
1447         struct sock_xprt *transport =
1448                 container_of(work, struct sock_xprt, recv_worker);
1449         unsigned int pflags = memalloc_nofs_save();
1450 
1451         xs_udp_data_receive(transport);
1452         memalloc_nofs_restore(pflags);
1453 }
1454 
1455 /**
1456  * xs_data_ready - "data ready" callback for UDP sockets
1457  * @sk: socket with data to read
1458  *
1459  */
1460 static void xs_data_ready(struct sock *sk)
1461 {
1462         struct rpc_xprt *xprt;
1463 
1464         read_lock_bh(&sk->sk_callback_lock);
1465         dprintk("RPC:       xs_data_ready...\n");
1466         xprt = xprt_from_sock(sk);
1467         if (xprt != NULL) {
1468                 struct sock_xprt *transport = container_of(xprt,
1469                                 struct sock_xprt, xprt);
1470                 transport->old_data_ready(sk);
1471                 /* Any data means we had a useful conversation, so
1472                  * then we don't need to delay the next reconnect
1473                  */
1474                 if (xprt->reestablish_timeout)
1475                         xprt->reestablish_timeout = 0;
1476                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1477                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1478         }
1479         read_unlock_bh(&sk->sk_callback_lock);
1480 }
1481 
1482 /*
1483  * Helper function to force a TCP close if the server is sending
1484  * junk and/or it has put us in CLOSE_WAIT
1485  */
1486 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1487 {
1488         xprt_force_disconnect(xprt);
1489 }
1490 
1491 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1492 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1493 {
1494         return PAGE_SIZE;
1495 }
1496 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1497 
1498 /**
1499  * xs_tcp_state_change - callback to handle TCP socket state changes
1500  * @sk: socket whose state has changed
1501  *
1502  */
1503 static void xs_tcp_state_change(struct sock *sk)
1504 {
1505         struct rpc_xprt *xprt;
1506         struct sock_xprt *transport;
1507 
1508         read_lock_bh(&sk->sk_callback_lock);
1509         if (!(xprt = xprt_from_sock(sk)))
1510                 goto out;
1511         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1512         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1513                         sk->sk_state, xprt_connected(xprt),
1514                         sock_flag(sk, SOCK_DEAD),
1515                         sock_flag(sk, SOCK_ZAPPED),
1516                         sk->sk_shutdown);
1517 
1518         transport = container_of(xprt, struct sock_xprt, xprt);
1519         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1520         switch (sk->sk_state) {
1521         case TCP_ESTABLISHED:
1522                 if (!xprt_test_and_set_connected(xprt)) {
1523                         xprt->connect_cookie++;
1524                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1525                         xprt_clear_connecting(xprt);
1526 
1527                         xprt->stat.connect_count++;
1528                         xprt->stat.connect_time += (long)jiffies -
1529                                                    xprt->stat.connect_start;
1530                         xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1531                 }
1532                 break;
1533         case TCP_FIN_WAIT1:
1534                 /* The client initiated a shutdown of the socket */
1535                 xprt->connect_cookie++;
1536                 xprt->reestablish_timeout = 0;
1537                 set_bit(XPRT_CLOSING, &xprt->state);
1538                 smp_mb__before_atomic();
1539                 clear_bit(XPRT_CONNECTED, &xprt->state);
1540                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1541                 smp_mb__after_atomic();
1542                 break;
1543         case TCP_CLOSE_WAIT:
1544                 /* The server initiated a shutdown of the socket */
1545                 xprt->connect_cookie++;
1546                 clear_bit(XPRT_CONNECTED, &xprt->state);
1547                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1548                 /* fall through */
1549         case TCP_CLOSING:
1550                 /*
1551                  * If the server closed down the connection, make sure that
1552                  * we back off before reconnecting
1553                  */
1554                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1555                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1556                 break;
1557         case TCP_LAST_ACK:
1558                 set_bit(XPRT_CLOSING, &xprt->state);
1559                 smp_mb__before_atomic();
1560                 clear_bit(XPRT_CONNECTED, &xprt->state);
1561                 smp_mb__after_atomic();
1562                 break;
1563         case TCP_CLOSE:
1564                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1565                                         &transport->sock_state))
1566                         xprt_clear_connecting(xprt);
1567                 clear_bit(XPRT_CLOSING, &xprt->state);
1568                 /* Trigger the socket release */
1569                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1570         }
1571  out:
1572         read_unlock_bh(&sk->sk_callback_lock);
1573 }
1574 
1575 static void xs_write_space(struct sock *sk)
1576 {
1577         struct socket_wq *wq;
1578         struct sock_xprt *transport;
1579         struct rpc_xprt *xprt;
1580 
1581         if (!sk->sk_socket)
1582                 return;
1583         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1584 
1585         if (unlikely(!(xprt = xprt_from_sock(sk))))
1586                 return;
1587         transport = container_of(xprt, struct sock_xprt, xprt);
1588         rcu_read_lock();
1589         wq = rcu_dereference(sk->sk_wq);
1590         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1591                 goto out;
1592 
1593         xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1594         sk->sk_write_pending--;
1595 out:
1596         rcu_read_unlock();
1597 }
1598 
1599 /**
1600  * xs_udp_write_space - callback invoked when socket buffer space
1601  *                             becomes available
1602  * @sk: socket whose state has changed
1603  *
1604  * Called when more output buffer space is available for this socket.
1605  * We try not to wake our writers until they can make "significant"
1606  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1607  * with a bunch of small requests.
1608  */
1609 static void xs_udp_write_space(struct sock *sk)
1610 {
1611         read_lock_bh(&sk->sk_callback_lock);
1612 
1613         /* from net/core/sock.c:sock_def_write_space */
1614         if (sock_writeable(sk))
1615                 xs_write_space(sk);
1616 
1617         read_unlock_bh(&sk->sk_callback_lock);
1618 }
1619 
1620 /**
1621  * xs_tcp_write_space - callback invoked when socket buffer space
1622  *                             becomes available
1623  * @sk: socket whose state has changed
1624  *
1625  * Called when more output buffer space is available for this socket.
1626  * We try not to wake our writers until they can make "significant"
1627  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1628  * with a bunch of small requests.
1629  */
1630 static void xs_tcp_write_space(struct sock *sk)
1631 {
1632         read_lock_bh(&sk->sk_callback_lock);
1633 
1634         /* from net/core/stream.c:sk_stream_write_space */
1635         if (sk_stream_is_writeable(sk))
1636                 xs_write_space(sk);
1637 
1638         read_unlock_bh(&sk->sk_callback_lock);
1639 }
1640 
1641 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1642 {
1643         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1644         struct sock *sk = transport->inet;
1645 
1646         if (transport->rcvsize) {
1647                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1648                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1649         }
1650         if (transport->sndsize) {
1651                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1652                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1653                 sk->sk_write_space(sk);
1654         }
1655 }
1656 
1657 /**
1658  * xs_udp_set_buffer_size - set send and receive limits
1659  * @xprt: generic transport
1660  * @sndsize: requested size of send buffer, in bytes
1661  * @rcvsize: requested size of receive buffer, in bytes
1662  *
1663  * Set socket send and receive buffer size limits.
1664  */
1665 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1666 {
1667         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1668 
1669         transport->sndsize = 0;
1670         if (sndsize)
1671                 transport->sndsize = sndsize + 1024;
1672         transport->rcvsize = 0;
1673         if (rcvsize)
1674                 transport->rcvsize = rcvsize + 1024;
1675 
1676         xs_udp_do_set_buffer_size(xprt);
1677 }
1678 
1679 /**
1680  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1681  * @xprt: controlling transport
1682  * @task: task that timed out
1683  *
1684  * Adjust the congestion window after a retransmit timeout has occurred.
1685  */
1686 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1687 {
1688         spin_lock(&xprt->transport_lock);
1689         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1690         spin_unlock(&xprt->transport_lock);
1691 }
1692 
1693 static int xs_get_random_port(void)
1694 {
1695         unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1696         unsigned short range;
1697         unsigned short rand;
1698 
1699         if (max < min)
1700                 return -EADDRINUSE;
1701         range = max - min + 1;
1702         rand = (unsigned short) prandom_u32() % range;
1703         return rand + min;
1704 }
1705 
1706 /**
1707  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1708  * @sock: socket
1709  *
1710  * Note that this function has to be called on all sockets that share the
1711  * same port, and it must be called before binding.
1712  */
1713 static void xs_sock_set_reuseport(struct socket *sock)
1714 {
1715         int opt = 1;
1716 
1717         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1718                         (char *)&opt, sizeof(opt));
1719 }
1720 
1721 static unsigned short xs_sock_getport(struct socket *sock)
1722 {
1723         struct sockaddr_storage buf;
1724         unsigned short port = 0;
1725 
1726         if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1727                 goto out;
1728         switch (buf.ss_family) {
1729         case AF_INET6:
1730                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1731                 break;
1732         case AF_INET:
1733                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1734         }
1735 out:
1736         return port;
1737 }
1738 
1739 /**
1740  * xs_set_port - reset the port number in the remote endpoint address
1741  * @xprt: generic transport
1742  * @port: new port number
1743  *
1744  */
1745 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1746 {
1747         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1748 
1749         rpc_set_port(xs_addr(xprt), port);
1750         xs_update_peer_port(xprt);
1751 }
1752 
1753 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1754 {
1755         if (transport->srcport == 0 && transport->xprt.reuseport)
1756                 transport->srcport = xs_sock_getport(sock);
1757 }
1758 
1759 static int xs_get_srcport(struct sock_xprt *transport)
1760 {
1761         int port = transport->srcport;
1762 
1763         if (port == 0 && transport->xprt.resvport)
1764                 port = xs_get_random_port();
1765         return port;
1766 }
1767 
1768 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1769 {
1770         if (transport->srcport != 0)
1771                 transport->srcport = 0;
1772         if (!transport->xprt.resvport)
1773                 return 0;
1774         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1775                 return xprt_max_resvport;
1776         return --port;
1777 }
1778 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1779 {
1780         struct sockaddr_storage myaddr;
1781         int err, nloop = 0;
1782         int port = xs_get_srcport(transport);
1783         unsigned short last;
1784 
1785         /*
1786          * If we are asking for any ephemeral port (i.e. port == 0 &&
1787          * transport->xprt.resvport == 0), don't bind.  Let the local
1788          * port selection happen implicitly when the socket is used
1789          * (for example at connect time).
1790          *
1791          * This ensures that we can continue to establish TCP
1792          * connections even when all local ephemeral ports are already
1793          * a part of some TCP connection.  This makes no difference
1794          * for UDP sockets, but also doens't harm them.
1795          *
1796          * If we're asking for any reserved port (i.e. port == 0 &&
1797          * transport->xprt.resvport == 1) xs_get_srcport above will
1798          * ensure that port is non-zero and we will bind as needed.
1799          */
1800         if (port <= 0)
1801                 return port;
1802 
1803         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1804         do {
1805                 rpc_set_port((struct sockaddr *)&myaddr, port);
1806                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1807                                 transport->xprt.addrlen);
1808                 if (err == 0) {
1809                         transport->srcport = port;
1810                         break;
1811                 }
1812                 last = port;
1813                 port = xs_next_srcport(transport, port);
1814                 if (port > last)
1815                         nloop++;
1816         } while (err == -EADDRINUSE && nloop != 2);
1817 
1818         if (myaddr.ss_family == AF_INET)
1819                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1820                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1821                                 port, err ? "failed" : "ok", err);
1822         else
1823                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1824                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1825                                 port, err ? "failed" : "ok", err);
1826         return err;
1827 }
1828 
1829 /*
1830  * We don't support autobind on AF_LOCAL sockets
1831  */
1832 static void xs_local_rpcbind(struct rpc_task *task)
1833 {
1834         xprt_set_bound(task->tk_xprt);
1835 }
1836 
1837 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1838 {
1839 }
1840 
1841 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1842 static struct lock_class_key xs_key[2];
1843 static struct lock_class_key xs_slock_key[2];
1844 
1845 static inline void xs_reclassify_socketu(struct socket *sock)
1846 {
1847         struct sock *sk = sock->sk;
1848 
1849         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1850                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1851 }
1852 
1853 static inline void xs_reclassify_socket4(struct socket *sock)
1854 {
1855         struct sock *sk = sock->sk;
1856 
1857         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1858                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1859 }
1860 
1861 static inline void xs_reclassify_socket6(struct socket *sock)
1862 {
1863         struct sock *sk = sock->sk;
1864 
1865         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1866                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1867 }
1868 
1869 static inline void xs_reclassify_socket(int family, struct socket *sock)
1870 {
1871         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1872                 return;
1873 
1874         switch (family) {
1875         case AF_LOCAL:
1876                 xs_reclassify_socketu(sock);
1877                 break;
1878         case AF_INET:
1879                 xs_reclassify_socket4(sock);
1880                 break;
1881         case AF_INET6:
1882                 xs_reclassify_socket6(sock);
1883                 break;
1884         }
1885 }
1886 #else
1887 static inline void xs_reclassify_socket(int family, struct socket *sock)
1888 {
1889 }
1890 #endif
1891 
1892 static void xs_dummy_setup_socket(struct work_struct *work)
1893 {
1894 }
1895 
1896 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1897                 struct sock_xprt *transport, int family, int type,
1898                 int protocol, bool reuseport)
1899 {
1900         struct file *filp;
1901         struct socket *sock;
1902         int err;
1903 
1904         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1905         if (err < 0) {
1906                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1907                                 protocol, -err);
1908                 goto out;
1909         }
1910         xs_reclassify_socket(family, sock);
1911 
1912         if (reuseport)
1913                 xs_sock_set_reuseport(sock);
1914 
1915         err = xs_bind(transport, sock);
1916         if (err) {
1917                 sock_release(sock);
1918                 goto out;
1919         }
1920 
1921         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1922         if (IS_ERR(filp))
1923                 return ERR_CAST(filp);
1924         transport->file = filp;
1925 
1926         return sock;
1927 out:
1928         return ERR_PTR(err);
1929 }
1930 
1931 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1932                                       struct socket *sock)
1933 {
1934         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1935                                                                         xprt);
1936 
1937         if (!transport->inet) {
1938                 struct sock *sk = sock->sk;
1939 
1940                 write_lock_bh(&sk->sk_callback_lock);
1941 
1942                 xs_save_old_callbacks(transport, sk);
1943 
1944                 sk->sk_user_data = xprt;
1945                 sk->sk_data_ready = xs_data_ready;
1946                 sk->sk_write_space = xs_udp_write_space;
1947                 sock_set_flag(sk, SOCK_FASYNC);
1948                 sk->sk_error_report = xs_error_report;
1949 
1950                 xprt_clear_connected(xprt);
1951 
1952                 /* Reset to new socket */
1953                 transport->sock = sock;
1954                 transport->inet = sk;
1955 
1956                 write_unlock_bh(&sk->sk_callback_lock);
1957         }
1958 
1959         xs_stream_start_connect(transport);
1960 
1961         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1962 }
1963 
1964 /**
1965  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1966  * @transport: socket transport to connect
1967  */
1968 static int xs_local_setup_socket(struct sock_xprt *transport)
1969 {
1970         struct rpc_xprt *xprt = &transport->xprt;
1971         struct file *filp;
1972         struct socket *sock;
1973         int status = -EIO;
1974 
1975         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1976                                         SOCK_STREAM, 0, &sock, 1);
1977         if (status < 0) {
1978                 dprintk("RPC:       can't create AF_LOCAL "
1979                         "transport socket (%d).\n", -status);
1980                 goto out;
1981         }
1982         xs_reclassify_socket(AF_LOCAL, sock);
1983 
1984         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1985         if (IS_ERR(filp)) {
1986                 status = PTR_ERR(filp);
1987                 goto out;
1988         }
1989         transport->file = filp;
1990 
1991         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1992                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1993 
1994         status = xs_local_finish_connecting(xprt, sock);
1995         trace_rpc_socket_connect(xprt, sock, status);
1996         switch (status) {
1997         case 0:
1998                 dprintk("RPC:       xprt %p connected to %s\n",
1999                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2000                 xprt->stat.connect_count++;
2001                 xprt->stat.connect_time += (long)jiffies -
2002                                            xprt->stat.connect_start;
2003                 xprt_set_connected(xprt);
2004         case -ENOBUFS:
2005                 break;
2006         case -ENOENT:
2007                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
2008                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2009                 break;
2010         case -ECONNREFUSED:
2011                 dprintk("RPC:       xprt %p: connection refused for %s\n",
2012                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2013                 break;
2014         default:
2015                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2016                                 __func__, -status,
2017                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
2018         }
2019 
2020 out:
2021         xprt_clear_connecting(xprt);
2022         xprt_wake_pending_tasks(xprt, status);
2023         return status;
2024 }
2025 
2026 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2027 {
2028         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2029         int ret;
2030 
2031          if (RPC_IS_ASYNC(task)) {
2032                 /*
2033                  * We want the AF_LOCAL connect to be resolved in the
2034                  * filesystem namespace of the process making the rpc
2035                  * call.  Thus we connect synchronously.
2036                  *
2037                  * If we want to support asynchronous AF_LOCAL calls,
2038                  * we'll need to figure out how to pass a namespace to
2039                  * connect.
2040                  */
2041                 task->tk_rpc_status = -ENOTCONN;
2042                 rpc_exit(task, -ENOTCONN);
2043                 return;
2044         }
2045         ret = xs_local_setup_socket(transport);
2046         if (ret && !RPC_IS_SOFTCONN(task))
2047                 msleep_interruptible(15000);
2048 }
2049 
2050 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2051 /*
2052  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2053  * know that we have exclusive access to the socket), to guard against
2054  * races with xs_reset_transport.
2055  */
2056 static void xs_set_memalloc(struct rpc_xprt *xprt)
2057 {
2058         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2059                         xprt);
2060 
2061         /*
2062          * If there's no sock, then we have nothing to set. The
2063          * reconnecting process will get it for us.
2064          */
2065         if (!transport->inet)
2066                 return;
2067         if (atomic_read(&xprt->swapper))
2068                 sk_set_memalloc(transport->inet);
2069 }
2070 
2071 /**
2072  * xs_enable_swap - Tag this transport as being used for swap.
2073  * @xprt: transport to tag
2074  *
2075  * Take a reference to this transport on behalf of the rpc_clnt, and
2076  * optionally mark it for swapping if it wasn't already.
2077  */
2078 static int
2079 xs_enable_swap(struct rpc_xprt *xprt)
2080 {
2081         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2082 
2083         if (atomic_inc_return(&xprt->swapper) != 1)
2084                 return 0;
2085         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2086                 return -ERESTARTSYS;
2087         if (xs->inet)
2088                 sk_set_memalloc(xs->inet);
2089         xprt_release_xprt(xprt, NULL);
2090         return 0;
2091 }
2092 
2093 /**
2094  * xs_disable_swap - Untag this transport as being used for swap.
2095  * @xprt: transport to tag
2096  *
2097  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2098  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2099  */
2100 static void
2101 xs_disable_swap(struct rpc_xprt *xprt)
2102 {
2103         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2104 
2105         if (!atomic_dec_and_test(&xprt->swapper))
2106                 return;
2107         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2108                 return;
2109         if (xs->inet)
2110                 sk_clear_memalloc(xs->inet);
2111         xprt_release_xprt(xprt, NULL);
2112 }
2113 #else
2114 static void xs_set_memalloc(struct rpc_xprt *xprt)
2115 {
2116 }
2117 
2118 static int
2119 xs_enable_swap(struct rpc_xprt *xprt)
2120 {
2121         return -EINVAL;
2122 }
2123 
2124 static void
2125 xs_disable_swap(struct rpc_xprt *xprt)
2126 {
2127 }
2128 #endif
2129 
2130 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2131 {
2132         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2133 
2134         if (!transport->inet) {
2135                 struct sock *sk = sock->sk;
2136 
2137                 write_lock_bh(&sk->sk_callback_lock);
2138 
2139                 xs_save_old_callbacks(transport, sk);
2140 
2141                 sk->sk_user_data = xprt;
2142                 sk->sk_data_ready = xs_data_ready;
2143                 sk->sk_write_space = xs_udp_write_space;
2144                 sock_set_flag(sk, SOCK_FASYNC);
2145 
2146                 xprt_set_connected(xprt);
2147 
2148                 /* Reset to new socket */
2149                 transport->sock = sock;
2150                 transport->inet = sk;
2151 
2152                 xs_set_memalloc(xprt);
2153 
2154                 write_unlock_bh(&sk->sk_callback_lock);
2155         }
2156         xs_udp_do_set_buffer_size(xprt);
2157 
2158         xprt->stat.connect_start = jiffies;
2159 }
2160 
2161 static void xs_udp_setup_socket(struct work_struct *work)
2162 {
2163         struct sock_xprt *transport =
2164                 container_of(work, struct sock_xprt, connect_worker.work);
2165         struct rpc_xprt *xprt = &transport->xprt;
2166         struct socket *sock;
2167         int status = -EIO;
2168 
2169         sock = xs_create_sock(xprt, transport,
2170                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2171                         IPPROTO_UDP, false);
2172         if (IS_ERR(sock))
2173                 goto out;
2174 
2175         dprintk("RPC:       worker connecting xprt %p via %s to "
2176                                 "%s (port %s)\n", xprt,
2177                         xprt->address_strings[RPC_DISPLAY_PROTO],
2178                         xprt->address_strings[RPC_DISPLAY_ADDR],
2179                         xprt->address_strings[RPC_DISPLAY_PORT]);
2180 
2181         xs_udp_finish_connecting(xprt, sock);
2182         trace_rpc_socket_connect(xprt, sock, 0);
2183         status = 0;
2184 out:
2185         xprt_clear_connecting(xprt);
2186         xprt_unlock_connect(xprt, transport);
2187         xprt_wake_pending_tasks(xprt, status);
2188 }
2189 
2190 /**
2191  * xs_tcp_shutdown - gracefully shut down a TCP socket
2192  * @xprt: transport
2193  *
2194  * Initiates a graceful shutdown of the TCP socket by calling the
2195  * equivalent of shutdown(SHUT_RDWR);
2196  */
2197 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2198 {
2199         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2200         struct socket *sock = transport->sock;
2201         int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2202 
2203         if (sock == NULL)
2204                 return;
2205         switch (skst) {
2206         default:
2207                 kernel_sock_shutdown(sock, SHUT_RDWR);
2208                 trace_rpc_socket_shutdown(xprt, sock);
2209                 break;
2210         case TCP_CLOSE:
2211         case TCP_TIME_WAIT:
2212                 xs_reset_transport(transport);
2213         }
2214 }
2215 
2216 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2217                 struct socket *sock)
2218 {
2219         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2220         unsigned int keepidle;
2221         unsigned int keepcnt;
2222         unsigned int opt_on = 1;
2223         unsigned int timeo;
2224 
2225         spin_lock(&xprt->transport_lock);
2226         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2227         keepcnt = xprt->timeout->to_retries + 1;
2228         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2229                 (xprt->timeout->to_retries + 1);
2230         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2231         spin_unlock(&xprt->transport_lock);
2232 
2233         /* TCP Keepalive options */
2234         kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2235                         (char *)&opt_on, sizeof(opt_on));
2236         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2237                         (char *)&keepidle, sizeof(keepidle));
2238         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2239                         (char *)&keepidle, sizeof(keepidle));
2240         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2241                         (char *)&keepcnt, sizeof(keepcnt));
2242 
2243         /* TCP user timeout (see RFC5482) */
2244         kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2245                         (char *)&timeo, sizeof(timeo));
2246 }
2247 
2248 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2249                 unsigned long connect_timeout,
2250                 unsigned long reconnect_timeout)
2251 {
2252         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2253         struct rpc_timeout to;
2254         unsigned long initval;
2255 
2256         spin_lock(&xprt->transport_lock);
2257         if (reconnect_timeout < xprt->max_reconnect_timeout)
2258                 xprt->max_reconnect_timeout = reconnect_timeout;
2259         if (connect_timeout < xprt->connect_timeout) {
2260                 memcpy(&to, xprt->timeout, sizeof(to));
2261                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2262                 /* Arbitrary lower limit */
2263                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2264                         initval = XS_TCP_INIT_REEST_TO << 1;
2265                 to.to_initval = initval;
2266                 to.to_maxval = initval;
2267                 memcpy(&transport->tcp_timeout, &to,
2268                                 sizeof(transport->tcp_timeout));
2269                 xprt->timeout = &transport->tcp_timeout;
2270                 xprt->connect_timeout = connect_timeout;
2271         }
2272         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2273         spin_unlock(&xprt->transport_lock);
2274 }
2275 
2276 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2277 {
2278         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2279         int ret = -ENOTCONN;
2280 
2281         if (!transport->inet) {
2282                 struct sock *sk = sock->sk;
2283                 unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2284 
2285                 /* Avoid temporary address, they are bad for long-lived
2286                  * connections such as NFS mounts.
2287                  * RFC4941, section 3.6 suggests that:
2288                  *    Individual applications, which have specific
2289                  *    knowledge about the normal duration of connections,
2290                  *    MAY override this as appropriate.
2291                  */
2292                 kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2293                                 (char *)&addr_pref, sizeof(addr_pref));
2294 
2295                 xs_tcp_set_socket_timeouts(xprt, sock);
2296 
2297                 write_lock_bh(&sk->sk_callback_lock);
2298 
2299                 xs_save_old_callbacks(transport, sk);
2300 
2301                 sk->sk_user_data = xprt;
2302                 sk->sk_data_ready = xs_data_ready;
2303                 sk->sk_state_change = xs_tcp_state_change;
2304                 sk->sk_write_space = xs_tcp_write_space;
2305                 sock_set_flag(sk, SOCK_FASYNC);
2306                 sk->sk_error_report = xs_error_report;
2307 
2308                 /* socket options */
2309                 sock_reset_flag(sk, SOCK_LINGER);
2310                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2311 
2312                 xprt_clear_connected(xprt);
2313 
2314                 /* Reset to new socket */
2315                 transport->sock = sock;
2316                 transport->inet = sk;
2317 
2318                 write_unlock_bh(&sk->sk_callback_lock);
2319         }
2320 
2321         if (!xprt_bound(xprt))
2322                 goto out;
2323 
2324         xs_set_memalloc(xprt);
2325 
2326         xs_stream_start_connect(transport);
2327 
2328         /* Tell the socket layer to start connecting... */
2329         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2330         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2331         switch (ret) {
2332         case 0:
2333                 xs_set_srcport(transport, sock);
2334                 /* fall through */
2335         case -EINPROGRESS:
2336                 /* SYN_SENT! */
2337                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2338                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2339                 break;
2340         case -EADDRNOTAVAIL:
2341                 /* Source port number is unavailable. Try a new one! */
2342                 transport->srcport = 0;
2343         }
2344 out:
2345         return ret;
2346 }
2347 
2348 /**
2349  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2350  * @work: queued work item
2351  *
2352  * Invoked by a work queue tasklet.
2353  */
2354 static void xs_tcp_setup_socket(struct work_struct *work)
2355 {
2356         struct sock_xprt *transport =
2357                 container_of(work, struct sock_xprt, connect_worker.work);
2358         struct socket *sock = transport->sock;
2359         struct rpc_xprt *xprt = &transport->xprt;
2360         int status = -EIO;
2361 
2362         if (!sock) {
2363                 sock = xs_create_sock(xprt, transport,
2364                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2365                                 IPPROTO_TCP, true);
2366                 if (IS_ERR(sock)) {
2367                         status = PTR_ERR(sock);
2368                         goto out;
2369                 }
2370         }
2371 
2372         dprintk("RPC:       worker connecting xprt %p via %s to "
2373                                 "%s (port %s)\n", xprt,
2374                         xprt->address_strings[RPC_DISPLAY_PROTO],
2375                         xprt->address_strings[RPC_DISPLAY_ADDR],
2376                         xprt->address_strings[RPC_DISPLAY_PORT]);
2377 
2378         status = xs_tcp_finish_connecting(xprt, sock);
2379         trace_rpc_socket_connect(xprt, sock, status);
2380         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2381                         xprt, -status, xprt_connected(xprt),
2382                         sock->sk->sk_state);
2383         switch (status) {
2384         default:
2385                 printk("%s: connect returned unhandled error %d\n",
2386                         __func__, status);
2387                 /* fall through */
2388         case -EADDRNOTAVAIL:
2389                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2390                  * and retry
2391                  */
2392                 xs_tcp_force_close(xprt);
2393                 break;
2394         case 0:
2395         case -EINPROGRESS:
2396         case -EALREADY:
2397                 xprt_unlock_connect(xprt, transport);
2398                 return;
2399         case -EINVAL:
2400                 /* Happens, for instance, if the user specified a link
2401                  * local IPv6 address without a scope-id.
2402                  */
2403         case -ECONNREFUSED:
2404         case -ECONNRESET:
2405         case -ENETDOWN:
2406         case -ENETUNREACH:
2407         case -EHOSTUNREACH:
2408         case -EADDRINUSE:
2409         case -ENOBUFS:
2410                 /*
2411                  * xs_tcp_force_close() wakes tasks with -EIO.
2412                  * We need to wake them first to ensure the
2413                  * correct error code.
2414                  */
2415                 xprt_wake_pending_tasks(xprt, status);
2416                 xs_tcp_force_close(xprt);
2417                 goto out;
2418         }
2419         status = -EAGAIN;
2420 out:
2421         xprt_clear_connecting(xprt);
2422         xprt_unlock_connect(xprt, transport);
2423         xprt_wake_pending_tasks(xprt, status);
2424 }
2425 
2426 /**
2427  * xs_connect - connect a socket to a remote endpoint
2428  * @xprt: pointer to transport structure
2429  * @task: address of RPC task that manages state of connect request
2430  *
2431  * TCP: If the remote end dropped the connection, delay reconnecting.
2432  *
2433  * UDP socket connects are synchronous, but we use a work queue anyway
2434  * to guarantee that even unprivileged user processes can set up a
2435  * socket on a privileged port.
2436  *
2437  * If a UDP socket connect fails, the delay behavior here prevents
2438  * retry floods (hard mounts).
2439  */
2440 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2441 {
2442         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2443         unsigned long delay = 0;
2444 
2445         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2446 
2447         if (transport->sock != NULL) {
2448                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2449                                 "seconds\n",
2450                                 xprt, xprt->reestablish_timeout / HZ);
2451 
2452                 /* Start by resetting any existing state */
2453                 xs_reset_transport(transport);
2454 
2455                 delay = xprt_reconnect_delay(xprt);
2456                 xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2457 
2458         } else
2459                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2460 
2461         queue_delayed_work(xprtiod_workqueue,
2462                         &transport->connect_worker,
2463                         delay);
2464 }
2465 
2466 static void xs_wake_disconnect(struct sock_xprt *transport)
2467 {
2468         if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2469                 xs_tcp_force_close(&transport->xprt);
2470 }
2471 
2472 static void xs_wake_write(struct sock_xprt *transport)
2473 {
2474         if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2475                 xprt_write_space(&transport->xprt);
2476 }
2477 
2478 static void xs_wake_error(struct sock_xprt *transport)
2479 {
2480         int sockerr;
2481 
2482         if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2483                 return;
2484         mutex_lock(&transport->recv_mutex);
2485         if (transport->sock == NULL)
2486                 goto out;
2487         if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2488                 goto out;
2489         sockerr = xchg(&transport->xprt_err, 0);
2490         if (sockerr < 0)
2491                 xprt_wake_pending_tasks(&transport->xprt, sockerr);
2492 out:
2493         mutex_unlock(&transport->recv_mutex);
2494 }
2495 
2496 static void xs_wake_pending(struct sock_xprt *transport)
2497 {
2498         if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2499                 xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2500 }
2501 
2502 static void xs_error_handle(struct work_struct *work)
2503 {
2504         struct sock_xprt *transport = container_of(work,
2505                         struct sock_xprt, error_worker);
2506 
2507         xs_wake_disconnect(transport);
2508         xs_wake_write(transport);
2509         xs_wake_error(transport);
2510         xs_wake_pending(transport);
2511 }
2512 
2513 /**
2514  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2515  * @xprt: rpc_xprt struct containing statistics
2516  * @seq: output file
2517  *
2518  */
2519 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2520 {
2521         long idle_time = 0;
2522 
2523         if (xprt_connected(xprt))
2524                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2525 
2526         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2527                         "%llu %llu %lu %llu %llu\n",
2528                         xprt->stat.bind_count,
2529                         xprt->stat.connect_count,
2530                         xprt->stat.connect_time / HZ,
2531                         idle_time,
2532                         xprt->stat.sends,
2533                         xprt->stat.recvs,
2534                         xprt->stat.bad_xids,
2535                         xprt->stat.req_u,
2536                         xprt->stat.bklog_u,
2537                         xprt->stat.max_slots,
2538                         xprt->stat.sending_u,
2539                         xprt->stat.pending_u);
2540 }
2541 
2542 /**
2543  * xs_udp_print_stats - display UDP socket-specifc stats
2544  * @xprt: rpc_xprt struct containing statistics
2545  * @seq: output file
2546  *
2547  */
2548 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2549 {
2550         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2551 
2552         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2553                         "%lu %llu %llu\n",
2554                         transport->srcport,
2555                         xprt->stat.bind_count,
2556                         xprt->stat.sends,
2557                         xprt->stat.recvs,
2558                         xprt->stat.bad_xids,
2559                         xprt->stat.req_u,
2560                         xprt->stat.bklog_u,
2561                         xprt->stat.max_slots,
2562                         xprt->stat.sending_u,
2563                         xprt->stat.pending_u);
2564 }
2565 
2566 /**
2567  * xs_tcp_print_stats - display TCP socket-specifc stats
2568  * @xprt: rpc_xprt struct containing statistics
2569  * @seq: output file
2570  *
2571  */
2572 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2573 {
2574         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2575         long idle_time = 0;
2576 
2577         if (xprt_connected(xprt))
2578                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2579 
2580         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2581                         "%llu %llu %lu %llu %llu\n",
2582                         transport->srcport,
2583                         xprt->stat.bind_count,
2584                         xprt->stat.connect_count,
2585                         xprt->stat.connect_time / HZ,
2586                         idle_time,
2587                         xprt->stat.sends,
2588                         xprt->stat.recvs,
2589                         xprt->stat.bad_xids,
2590                         xprt->stat.req_u,
2591                         xprt->stat.bklog_u,
2592                         xprt->stat.max_slots,
2593                         xprt->stat.sending_u,
2594                         xprt->stat.pending_u);
2595 }
2596 
2597 /*
2598  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2599  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2600  * to use the server side send routines.
2601  */
2602 static int bc_malloc(struct rpc_task *task)
2603 {
2604         struct rpc_rqst *rqst = task->tk_rqstp;
2605         size_t size = rqst->rq_callsize;
2606         struct page *page;
2607         struct rpc_buffer *buf;
2608 
2609         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2610                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2611                           size);
2612                 return -EINVAL;
2613         }
2614 
2615         page = alloc_page(GFP_KERNEL);
2616         if (!page)
2617                 return -ENOMEM;
2618 
2619         buf = page_address(page);
2620         buf->len = PAGE_SIZE;
2621 
2622         rqst->rq_buffer = buf->data;
2623         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2624         return 0;
2625 }
2626 
2627 /*
2628  * Free the space allocated in the bc_alloc routine
2629  */
2630 static void bc_free(struct rpc_task *task)
2631 {
2632         void *buffer = task->tk_rqstp->rq_buffer;
2633         struct rpc_buffer *buf;
2634 
2635         buf = container_of(buffer, struct rpc_buffer, data);
2636         free_page((unsigned long)buf);
2637 }
2638 
2639 /*
2640  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2641  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2642  */
2643 static int bc_sendto(struct rpc_rqst *req)
2644 {
2645         int len;
2646         struct xdr_buf *xbufp = &req->rq_snd_buf;
2647         struct sock_xprt *transport =
2648                         container_of(req->rq_xprt, struct sock_xprt, xprt);
2649         unsigned long headoff;
2650         unsigned long tailoff;
2651         struct page *tailpage;
2652         struct msghdr msg = {
2653                 .msg_flags      = MSG_MORE
2654         };
2655         rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2656                                          (u32)xbufp->len);
2657         struct kvec iov = {
2658                 .iov_base       = &marker,
2659                 .iov_len        = sizeof(marker),
2660         };
2661 
2662         req->rq_xtime = ktime_get();
2663 
2664         len = kernel_sendmsg(transport->sock, &msg, &iov, 1, iov.iov_len);
2665         if (len != iov.iov_len)
2666                 return -EAGAIN;
2667 
2668         tailpage = NULL;
2669         if (xbufp->tail[0].iov_len)
2670                 tailpage = virt_to_page(xbufp->tail[0].iov_base);
2671         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2672         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2673         len = svc_send_common(transport->sock, xbufp,
2674                               virt_to_page(xbufp->head[0].iov_base), headoff,
2675                               tailpage, tailoff);
2676         if (len != xbufp->len)
2677                 return -EAGAIN;
2678         return len;
2679 }
2680 
2681 /*
2682  * The send routine. Borrows from svc_send
2683  */
2684 static int bc_send_request(struct rpc_rqst *req)
2685 {
2686         struct svc_xprt *xprt;
2687         int len;
2688 
2689         /*
2690          * Get the server socket associated with this callback xprt
2691          */
2692         xprt = req->rq_xprt->bc_xprt;
2693 
2694         /*
2695          * Grab the mutex to serialize data as the connection is shared
2696          * with the fore channel
2697          */
2698         mutex_lock(&xprt->xpt_mutex);
2699         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2700                 len = -ENOTCONN;
2701         else
2702                 len = bc_sendto(req);
2703         mutex_unlock(&xprt->xpt_mutex);
2704 
2705         if (len > 0)
2706                 len = 0;
2707 
2708         return len;
2709 }
2710 
2711 /*
2712  * The close routine. Since this is client initiated, we do nothing
2713  */
2714 
2715 static void bc_close(struct rpc_xprt *xprt)
2716 {
2717         xprt_disconnect_done(xprt);
2718 }
2719 
2720 /*
2721  * The xprt destroy routine. Again, because this connection is client
2722  * initiated, we do nothing
2723  */
2724 
2725 static void bc_destroy(struct rpc_xprt *xprt)
2726 {
2727         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2728 
2729         xs_xprt_free(xprt);
2730         module_put(THIS_MODULE);
2731 }
2732 
2733 static const struct rpc_xprt_ops xs_local_ops = {
2734         .reserve_xprt           = xprt_reserve_xprt,
2735         .release_xprt           = xprt_release_xprt,
2736         .alloc_slot             = xprt_alloc_slot,
2737         .free_slot              = xprt_free_slot,
2738         .rpcbind                = xs_local_rpcbind,
2739         .set_port               = xs_local_set_port,
2740         .connect                = xs_local_connect,
2741         .buf_alloc              = rpc_malloc,
2742         .buf_free               = rpc_free,
2743         .prepare_request        = xs_stream_prepare_request,
2744         .send_request           = xs_local_send_request,
2745         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2746         .close                  = xs_close,
2747         .destroy                = xs_destroy,
2748         .print_stats            = xs_local_print_stats,
2749         .enable_swap            = xs_enable_swap,
2750         .disable_swap           = xs_disable_swap,
2751 };
2752 
2753 static const struct rpc_xprt_ops xs_udp_ops = {
2754         .set_buffer_size        = xs_udp_set_buffer_size,
2755         .reserve_xprt           = xprt_reserve_xprt_cong,
2756         .release_xprt           = xprt_release_xprt_cong,
2757         .alloc_slot             = xprt_alloc_slot,
2758         .free_slot              = xprt_free_slot,
2759         .rpcbind                = rpcb_getport_async,
2760         .set_port               = xs_set_port,
2761         .connect                = xs_connect,
2762         .buf_alloc              = rpc_malloc,
2763         .buf_free               = rpc_free,
2764         .send_request           = xs_udp_send_request,
2765         .wait_for_reply_request = xprt_wait_for_reply_request_rtt,
2766         .timer                  = xs_udp_timer,
2767         .release_request        = xprt_release_rqst_cong,
2768         .close                  = xs_close,
2769         .destroy                = xs_destroy,
2770         .print_stats            = xs_udp_print_stats,
2771         .enable_swap            = xs_enable_swap,
2772         .disable_swap           = xs_disable_swap,
2773         .inject_disconnect      = xs_inject_disconnect,
2774 };
2775 
2776 static const struct rpc_xprt_ops xs_tcp_ops = {
2777         .reserve_xprt           = xprt_reserve_xprt,
2778         .release_xprt           = xprt_release_xprt,
2779         .alloc_slot             = xprt_alloc_slot,
2780         .free_slot              = xprt_free_slot,
2781         .rpcbind                = rpcb_getport_async,
2782         .set_port               = xs_set_port,
2783         .connect                = xs_connect,
2784         .buf_alloc              = rpc_malloc,
2785         .buf_free               = rpc_free,
2786         .prepare_request        = xs_stream_prepare_request,
2787         .send_request           = xs_tcp_send_request,
2788         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2789         .close                  = xs_tcp_shutdown,
2790         .destroy                = xs_destroy,
2791         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2792         .print_stats            = xs_tcp_print_stats,
2793         .enable_swap            = xs_enable_swap,
2794         .disable_swap           = xs_disable_swap,
2795         .inject_disconnect      = xs_inject_disconnect,
2796 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2797         .bc_setup               = xprt_setup_bc,
2798         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2799         .bc_num_slots           = xprt_bc_max_slots,
2800         .bc_free_rqst           = xprt_free_bc_rqst,
2801         .bc_destroy             = xprt_destroy_bc,
2802 #endif
2803 };
2804 
2805 /*
2806  * The rpc_xprt_ops for the server backchannel
2807  */
2808 
2809 static const struct rpc_xprt_ops bc_tcp_ops = {
2810         .reserve_xprt           = xprt_reserve_xprt,
2811         .release_xprt           = xprt_release_xprt,
2812         .alloc_slot             = xprt_alloc_slot,
2813         .free_slot              = xprt_free_slot,
2814         .buf_alloc              = bc_malloc,
2815         .buf_free               = bc_free,
2816         .send_request           = bc_send_request,
2817         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2818         .close                  = bc_close,
2819         .destroy                = bc_destroy,
2820         .print_stats            = xs_tcp_print_stats,
2821         .enable_swap            = xs_enable_swap,
2822         .disable_swap           = xs_disable_swap,
2823         .inject_disconnect      = xs_inject_disconnect,
2824 };
2825 
2826 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2827 {
2828         static const struct sockaddr_in sin = {
2829                 .sin_family             = AF_INET,
2830                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2831         };
2832         static const struct sockaddr_in6 sin6 = {
2833                 .sin6_family            = AF_INET6,
2834                 .sin6_addr              = IN6ADDR_ANY_INIT,
2835         };
2836 
2837         switch (family) {
2838         case AF_LOCAL:
2839                 break;
2840         case AF_INET:
2841                 memcpy(sap, &sin, sizeof(sin));
2842                 break;
2843         case AF_INET6:
2844                 memcpy(sap, &sin6, sizeof(sin6));
2845                 break;
2846         default:
2847                 dprintk("RPC:       %s: Bad address family\n", __func__);
2848                 return -EAFNOSUPPORT;
2849         }
2850         return 0;
2851 }
2852 
2853 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2854                                       unsigned int slot_table_size,
2855                                       unsigned int max_slot_table_size)
2856 {
2857         struct rpc_xprt *xprt;
2858         struct sock_xprt *new;
2859 
2860         if (args->addrlen > sizeof(xprt->addr)) {
2861                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2862                 return ERR_PTR(-EBADF);
2863         }
2864 
2865         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2866                         max_slot_table_size);
2867         if (xprt == NULL) {
2868                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2869                                 "rpc_xprt\n");
2870                 return ERR_PTR(-ENOMEM);
2871         }
2872 
2873         new = container_of(xprt, struct sock_xprt, xprt);
2874         mutex_init(&new->recv_mutex);
2875         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2876         xprt->addrlen = args->addrlen;
2877         if (args->srcaddr)
2878                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2879         else {
2880                 int err;
2881                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2882                                         (struct sockaddr *)&new->srcaddr);
2883                 if (err != 0) {
2884                         xprt_free(xprt);
2885                         return ERR_PTR(err);
2886                 }
2887         }
2888 
2889         return xprt;
2890 }
2891 
2892 static const struct rpc_timeout xs_local_default_timeout = {
2893         .to_initval = 10 * HZ,
2894         .to_maxval = 10 * HZ,
2895         .to_retries = 2,
2896 };
2897 
2898 /**
2899  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2900  * @args: rpc transport creation arguments
2901  *
2902  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2903  */
2904 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2905 {
2906         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2907         struct sock_xprt *transport;
2908         struct rpc_xprt *xprt;
2909         struct rpc_xprt *ret;
2910 
2911         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2912                         xprt_max_tcp_slot_table_entries);
2913         if (IS_ERR(xprt))
2914                 return xprt;
2915         transport = container_of(xprt, struct sock_xprt, xprt);
2916 
2917         xprt->prot = 0;
2918         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2919 
2920         xprt->bind_timeout = XS_BIND_TO;
2921         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2922         xprt->idle_timeout = XS_IDLE_DISC_TO;
2923 
2924         xprt->ops = &xs_local_ops;
2925         xprt->timeout = &xs_local_default_timeout;
2926 
2927         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2928         INIT_WORK(&transport->error_worker, xs_error_handle);
2929         INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2930 
2931         switch (sun->sun_family) {
2932         case AF_LOCAL:
2933                 if (sun->sun_path[0] != '/') {
2934                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2935                                         sun->sun_path);
2936                         ret = ERR_PTR(-EINVAL);
2937                         goto out_err;
2938                 }
2939                 xprt_set_bound(xprt);
2940                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2941                 ret = ERR_PTR(xs_local_setup_socket(transport));
2942                 if (ret)
2943                         goto out_err;
2944                 break;
2945         default:
2946                 ret = ERR_PTR(-EAFNOSUPPORT);
2947                 goto out_err;
2948         }
2949 
2950         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2951                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2952 
2953         if (try_module_get(THIS_MODULE))
2954                 return xprt;
2955         ret = ERR_PTR(-EINVAL);
2956 out_err:
2957         xs_xprt_free(xprt);
2958         return ret;
2959 }
2960 
2961 static const struct rpc_timeout xs_udp_default_timeout = {
2962         .to_initval = 5 * HZ,
2963         .to_maxval = 30 * HZ,
2964         .to_increment = 5 * HZ,
2965         .to_retries = 5,
2966 };
2967 
2968 /**
2969  * xs_setup_udp - Set up transport to use a UDP socket
2970  * @args: rpc transport creation arguments
2971  *
2972  */
2973 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2974 {
2975         struct sockaddr *addr = args->dstaddr;
2976         struct rpc_xprt *xprt;
2977         struct sock_xprt *transport;
2978         struct rpc_xprt *ret;
2979 
2980         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2981                         xprt_udp_slot_table_entries);
2982         if (IS_ERR(xprt))
2983                 return xprt;
2984         transport = container_of(xprt, struct sock_xprt, xprt);
2985 
2986         xprt->prot = IPPROTO_UDP;
2987         /* XXX: header size can vary due to auth type, IPv6, etc. */
2988         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2989 
2990         xprt->bind_timeout = XS_BIND_TO;
2991         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2992         xprt->idle_timeout = XS_IDLE_DISC_TO;
2993 
2994         xprt->ops = &xs_udp_ops;
2995 
2996         xprt->timeout = &xs_udp_default_timeout;
2997 
2998         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2999         INIT_WORK(&transport->error_worker, xs_error_handle);
3000         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
3001 
3002         switch (addr->sa_family) {
3003         case AF_INET:
3004                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3005                         xprt_set_bound(xprt);
3006 
3007                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
3008                 break;
3009         case AF_INET6:
3010                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3011                         xprt_set_bound(xprt);
3012 
3013                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
3014                 break;
3015         default:
3016                 ret = ERR_PTR(-EAFNOSUPPORT);
3017                 goto out_err;
3018         }
3019 
3020         if (xprt_bound(xprt))
3021                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3022                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3023                                 xprt->address_strings[RPC_DISPLAY_PORT],
3024                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3025         else
3026                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3027                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3028                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3029 
3030         if (try_module_get(THIS_MODULE))
3031                 return xprt;
3032         ret = ERR_PTR(-EINVAL);
3033 out_err:
3034         xs_xprt_free(xprt);
3035         return ret;
3036 }
3037 
3038 static const struct rpc_timeout xs_tcp_default_timeout = {
3039         .to_initval = 60 * HZ,
3040         .to_maxval = 60 * HZ,
3041         .to_retries = 2,
3042 };
3043 
3044 /**
3045  * xs_setup_tcp - Set up transport to use a TCP socket
3046  * @args: rpc transport creation arguments
3047  *
3048  */
3049 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
3050 {
3051         struct sockaddr *addr = args->dstaddr;
3052         struct rpc_xprt *xprt;
3053         struct sock_xprt *transport;
3054         struct rpc_xprt *ret;
3055         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3056 
3057         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3058                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3059 
3060         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3061                         max_slot_table_size);
3062         if (IS_ERR(xprt))
3063                 return xprt;
3064         transport = container_of(xprt, struct sock_xprt, xprt);
3065 
3066         xprt->prot = IPPROTO_TCP;
3067         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3068 
3069         xprt->bind_timeout = XS_BIND_TO;
3070         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3071         xprt->idle_timeout = XS_IDLE_DISC_TO;
3072 
3073         xprt->ops = &xs_tcp_ops;
3074         xprt->timeout = &xs_tcp_default_timeout;
3075 
3076         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3077         xprt->connect_timeout = xprt->timeout->to_initval *
3078                 (xprt->timeout->to_retries + 1);
3079 
3080         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
3081         INIT_WORK(&transport->error_worker, xs_error_handle);
3082         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3083 
3084         switch (addr->sa_family) {
3085         case AF_INET:
3086                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3087                         xprt_set_bound(xprt);
3088 
3089                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3090                 break;
3091         case AF_INET6:
3092                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3093                         xprt_set_bound(xprt);
3094 
3095                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3096                 break;
3097         default:
3098                 ret = ERR_PTR(-EAFNOSUPPORT);
3099                 goto out_err;
3100         }
3101 
3102         if (xprt_bound(xprt))
3103                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3104                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3105                                 xprt->address_strings[RPC_DISPLAY_PORT],
3106                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3107         else
3108                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3109                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3110                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3111 
3112         if (try_module_get(THIS_MODULE))
3113                 return xprt;
3114         ret = ERR_PTR(-EINVAL);
3115 out_err:
3116         xs_xprt_free(xprt);
3117         return ret;
3118 }
3119 
3120 /**
3121  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3122  * @args: rpc transport creation arguments
3123  *
3124  */
3125 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3126 {
3127         struct sockaddr *addr = args->dstaddr;
3128         struct rpc_xprt *xprt;
3129         struct sock_xprt *transport;
3130         struct svc_sock *bc_sock;
3131         struct rpc_xprt *ret;
3132 
3133         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3134                         xprt_tcp_slot_table_entries);
3135         if (IS_ERR(xprt))
3136                 return xprt;
3137         transport = container_of(xprt, struct sock_xprt, xprt);
3138 
3139         xprt->prot = IPPROTO_TCP;
3140         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3141         xprt->timeout = &xs_tcp_default_timeout;
3142 
3143         /* backchannel */
3144         xprt_set_bound(xprt);
3145         xprt->bind_timeout = 0;
3146         xprt->reestablish_timeout = 0;
3147         xprt->idle_timeout = 0;
3148 
3149         xprt->ops = &bc_tcp_ops;
3150 
3151         switch (addr->sa_family) {
3152         case AF_INET:
3153                 xs_format_peer_addresses(xprt, "tcp",
3154                                          RPCBIND_NETID_TCP);
3155                 break;
3156         case AF_INET6:
3157                 xs_format_peer_addresses(xprt, "tcp",
3158                                    RPCBIND_NETID_TCP6);
3159                 break;
3160         default:
3161                 ret = ERR_PTR(-EAFNOSUPPORT);
3162                 goto out_err;
3163         }
3164 
3165         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3166                         xprt->address_strings[RPC_DISPLAY_ADDR],
3167                         xprt->address_strings[RPC_DISPLAY_PORT],
3168                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3169 
3170         /*
3171          * Once we've associated a backchannel xprt with a connection,
3172          * we want to keep it around as long as the connection lasts,
3173          * in case we need to start using it for a backchannel again;
3174          * this reference won't be dropped until bc_xprt is destroyed.
3175          */
3176         xprt_get(xprt);
3177         args->bc_xprt->xpt_bc_xprt = xprt;
3178         xprt->bc_xprt = args->bc_xprt;
3179         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3180         transport->sock = bc_sock->sk_sock;
3181         transport->inet = bc_sock->sk_sk;
3182 
3183         /*
3184          * Since we don't want connections for the backchannel, we set
3185          * the xprt status to connected
3186          */
3187         xprt_set_connected(xprt);
3188 
3189         if (try_module_get(THIS_MODULE))
3190                 return xprt;
3191 
3192         args->bc_xprt->xpt_bc_xprt = NULL;
3193         args->bc_xprt->xpt_bc_xps = NULL;
3194         xprt_put(xprt);
3195         ret = ERR_PTR(-EINVAL);
3196 out_err:
3197         xs_xprt_free(xprt);
3198         return ret;
3199 }
3200 
3201 static struct xprt_class        xs_local_transport = {
3202         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3203         .name           = "named UNIX socket",
3204         .owner          = THIS_MODULE,
3205         .ident          = XPRT_TRANSPORT_LOCAL,
3206         .setup          = xs_setup_local,
3207 };
3208 
3209 static struct xprt_class        xs_udp_transport = {
3210         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3211         .name           = "udp",
3212         .owner          = THIS_MODULE,
3213         .ident          = XPRT_TRANSPORT_UDP,
3214         .setup          = xs_setup_udp,
3215 };
3216 
3217 static struct xprt_class        xs_tcp_transport = {
3218         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3219         .name           = "tcp",
3220         .owner          = THIS_MODULE,
3221         .ident          = XPRT_TRANSPORT_TCP,
3222         .setup          = xs_setup_tcp,
3223 };
3224 
3225 static struct xprt_class        xs_bc_tcp_transport = {
3226         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3227         .name           = "tcp NFSv4.1 backchannel",
3228         .owner          = THIS_MODULE,
3229         .ident          = XPRT_TRANSPORT_BC_TCP,
3230         .setup          = xs_setup_bc_tcp,
3231 };
3232 
3233 /**
3234  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3235  *
3236  */
3237 int init_socket_xprt(void)
3238 {
3239         if (!sunrpc_table_header)
3240                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3241 
3242         xprt_register_transport(&xs_local_transport);
3243         xprt_register_transport(&xs_udp_transport);
3244         xprt_register_transport(&xs_tcp_transport);
3245         xprt_register_transport(&xs_bc_tcp_transport);
3246 
3247         return 0;
3248 }
3249 
3250 /**
3251  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3252  *
3253  */
3254 void cleanup_socket_xprt(void)
3255 {
3256         if (sunrpc_table_header) {
3257                 unregister_sysctl_table(sunrpc_table_header);
3258                 sunrpc_table_header = NULL;
3259         }
3260 
3261         xprt_unregister_transport(&xs_local_transport);
3262         xprt_unregister_transport(&xs_udp_transport);
3263         xprt_unregister_transport(&xs_tcp_transport);
3264         xprt_unregister_transport(&xs_bc_tcp_transport);
3265 }
3266 
3267 static int param_set_uint_minmax(const char *val,
3268                 const struct kernel_param *kp,
3269                 unsigned int min, unsigned int max)
3270 {
3271         unsigned int num;
3272         int ret;
3273 
3274         if (!val)
3275                 return -EINVAL;
3276         ret = kstrtouint(val, 0, &num);
3277         if (ret)
3278                 return ret;
3279         if (num < min || num > max)
3280                 return -EINVAL;
3281         *((unsigned int *)kp->arg) = num;
3282         return 0;
3283 }
3284 
3285 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3286 {
3287         return param_set_uint_minmax(val, kp,
3288                         RPC_MIN_RESVPORT,
3289                         RPC_MAX_RESVPORT);
3290 }
3291 
3292 static const struct kernel_param_ops param_ops_portnr = {
3293         .set = param_set_portnr,
3294         .get = param_get_uint,
3295 };
3296 
3297 #define param_check_portnr(name, p) \
3298         __param_check(name, p, unsigned int);
3299 
3300 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3301 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3302 
3303 static int param_set_slot_table_size(const char *val,
3304                                      const struct kernel_param *kp)
3305 {
3306         return param_set_uint_minmax(val, kp,
3307                         RPC_MIN_SLOT_TABLE,
3308                         RPC_MAX_SLOT_TABLE);
3309 }
3310 
3311 static const struct kernel_param_ops param_ops_slot_table_size = {
3312         .set = param_set_slot_table_size,
3313         .get = param_get_uint,
3314 };
3315 
3316 #define param_check_slot_table_size(name, p) \
3317         __param_check(name, p, unsigned int);
3318 
3319 static int param_set_max_slot_table_size(const char *val,
3320                                      const struct kernel_param *kp)
3321 {
3322         return param_set_uint_minmax(val, kp,
3323                         RPC_MIN_SLOT_TABLE,
3324                         RPC_MAX_SLOT_TABLE_LIMIT);
3325 }
3326 
3327 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3328         .set = param_set_max_slot_table_size,
3329         .get = param_get_uint,
3330 };
3331 
3332 #define param_check_max_slot_table_size(name, p) \
3333         __param_check(name, p, unsigned int);
3334 
3335 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3336                    slot_table_size, 0644);
3337 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3338                    max_slot_table_size, 0644);
3339 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3340                    slot_table_size, 0644);
3341 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp