net/sunrpc/xprtsock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/net/sunrpc/xprtsock.c
   4  *
   5  * Client-side transport implementation for sockets.
   6  *
   7  * TCP callback races fixes (C) 1998 Red Hat
   8  * TCP send fixes (C) 1998 Red Hat
   9  * TCP NFS related read + write fixes
  10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
  11  *
  12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
  13  * Fix behaviour when socket buffer is full.
  14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  15  *
  16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
  17  *
  18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
  19  *   <gilles.quillard@bull.net>
  20  */
  21
  22 #include <linux/types.h>
  23 #include <linux/string.h>
  24 #include <linux/slab.h>
  25 #include <linux/module.h>
  26 #include <linux/capability.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/errno.h>
  29 #include <linux/socket.h>
  30 #include <linux/in.h>
  31 #include <linux/net.h>
  32 #include <linux/mm.h>
  33 #include <linux/un.h>
  34 #include <linux/udp.h>
  35 #include <linux/tcp.h>
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/sched.h>
  39 #include <linux/sunrpc/svcsock.h>
  40 #include <linux/sunrpc/xprtsock.h>
  41 #include <linux/file.h>
  42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
  43 #include <linux/sunrpc/bc_xprt.h>
  44 #endif
  45
  46 #include <net/sock.h>
  47 #include <net/checksum.h>
  48 #include <net/udp.h>
  49 #include <net/tcp.h>
  50 #include <linux/bvec.h>
  51 #include <linux/highmem.h>
  52 #include <linux/uio.h>
  53 #include <linux/sched/mm.h>
  54
  55 #include <trace/events/sunrpc.h>
  56
  57 #include "socklib.h"
  58 #include "sunrpc.h"
  59
  60 static void xs_close(struct rpc_xprt *xprt);
  61 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
  62                 struct socket *sock);
  63
  64 /*
  65  * xprtsock tunables
  66  */
  67 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  68 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
  69 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
  70
  71 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  72 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  73
  74 #define XS_TCP_LINGER_TO        (15U * HZ)
  75 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  76
  77 /*
  78  * We can register our own files under /proc/sys/sunrpc by
  79  * calling register_sysctl_table() again.  The files in that
  80  * directory become the union of all files registered there.
  81  *
  82  * We simply need to make sure that we don't collide with
  83  * someone else's file names!
  84  */
  85
  86 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  87 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  88 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
  89 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  90 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  91
  92 static struct ctl_table_header *sunrpc_table_header;
  93
  94 /*
  95  * FIXME: changing the UDP slot table size should also resize the UDP
  96  *        socket buffers for existing UDP transports
  97  */
  98 static struct ctl_table xs_tunables_table[] = {
  99         {
 100                 .procname       = "udp_slot_table_entries",
 101                 .data           = &xprt_udp_slot_table_entries,
 102                 .maxlen         = sizeof(unsigned int),
 103                 .mode           = 0644,
 104                 .proc_handler   = proc_dointvec_minmax,
 105                 .extra1         = &min_slot_table_size,
 106                 .extra2         = &max_slot_table_size
 107         },
 108         {
 109                 .procname       = "tcp_slot_table_entries",
 110                 .data           = &xprt_tcp_slot_table_entries,
 111                 .maxlen         = sizeof(unsigned int),
 112                 .mode           = 0644,
 113                 .proc_handler   = proc_dointvec_minmax,
 114                 .extra1         = &min_slot_table_size,
 115                 .extra2         = &max_slot_table_size
 116         },
 117         {
 118                 .procname       = "tcp_max_slot_table_entries",
 119                 .data           = &xprt_max_tcp_slot_table_entries,
 120                 .maxlen         = sizeof(unsigned int),
 121                 .mode           = 0644,
 122                 .proc_handler   = proc_dointvec_minmax,
 123                 .extra1         = &min_slot_table_size,
 124                 .extra2         = &max_tcp_slot_table_limit
 125         },
 126         {
 127                 .procname       = "min_resvport",
 128                 .data           = &xprt_min_resvport,
 129                 .maxlen         = sizeof(unsigned int),
 130                 .mode           = 0644,
 131                 .proc_handler   = proc_dointvec_minmax,
 132                 .extra1         = &xprt_min_resvport_limit,
 133                 .extra2         = &xprt_max_resvport_limit
 134         },
 135         {
 136                 .procname       = "max_resvport",
 137                 .data           = &xprt_max_resvport,
 138                 .maxlen         = sizeof(unsigned int),
 139                 .mode           = 0644,
 140                 .proc_handler   = proc_dointvec_minmax,
 141                 .extra1         = &xprt_min_resvport_limit,
 142                 .extra2         = &xprt_max_resvport_limit
 143         },
 144         {
 145                 .procname       = "tcp_fin_timeout",
 146                 .data           = &xs_tcp_fin_timeout,
 147                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 148                 .mode           = 0644,
 149                 .proc_handler   = proc_dointvec_jiffies,
 150         },
 151         { },
 152 };
 153
 154 static struct ctl_table sunrpc_table[] = {
 155         {
 156                 .procname       = "sunrpc",
 157                 .mode           = 0555,
 158                 .child          = xs_tunables_table
 159         },
 160         { },
 161 };
 162
 163 /*
 164  * Wait duration for a reply from the RPC portmapper.
 165  */
 166 #define XS_BIND_TO              (60U * HZ)
 167
 168 /*
 169  * Delay if a UDP socket connect error occurs.  This is most likely some
 170  * kind of resource problem on the local host.
 171  */
 172 #define XS_UDP_REEST_TO         (2U * HZ)
 173
 174 /*
 175  * The reestablish timeout allows clients to delay for a bit before attempting
 176  * to reconnect to a server that just dropped our connection.
 177  *
 178  * We implement an exponential backoff when trying to reestablish a TCP
 179  * transport connection with the server.  Some servers like to drop a TCP
 180  * connection when they are overworked, so we start with a short timeout and
 181  * increase over time if the server is down or not responding.
 182  */
 183 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 184
 185 /*
 186  * TCP idle timeout; client drops the transport socket if it is idle
 187  * for this long.  Note that we also timeout UDP sockets to prevent
 188  * holding port numbers when there is no RPC traffic.
 189  */
 190 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 191
 192 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 193 # undef  RPC_DEBUG_DATA
 194 # define RPCDBG_FACILITY        RPCDBG_TRANS
 195 #endif
 196
 197 #ifdef RPC_DEBUG_DATA
 198 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 199 {
 200         u8 *buf = (u8 *) packet;
 201         int j;
 202
 203         dprintk("RPC:       %s\n", msg);
 204         for (j = 0; j < count && j < 128; j += 4) {
 205                 if (!(j & 31)) {
 206                         if (j)
 207                                 dprintk("\n");
 208                         dprintk("0x%04x ", j);
 209                 }
 210                 dprintk("%02x%02x%02x%02x ",
 211                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 212         }
 213         dprintk("\n");
 214 }
 215 #else
 216 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 217 {
 218         /* NOP */
 219 }
 220 #endif
 221
 222 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 223 {
 224         return (struct rpc_xprt *) sk->sk_user_data;
 225 }
 226
 227 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 228 {
 229         return (struct sockaddr *) &xprt->addr;
 230 }
 231
 232 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
 233 {
 234         return (struct sockaddr_un *) &xprt->addr;
 235 }
 236
 237 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 238 {
 239         return (struct sockaddr_in *) &xprt->addr;
 240 }
 241
 242 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 243 {
 244         return (struct sockaddr_in6 *) &xprt->addr;
 245 }
 246
 247 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 248 {
 249         struct sockaddr *sap = xs_addr(xprt);
 250         struct sockaddr_in6 *sin6;
 251         struct sockaddr_in *sin;
 252         struct sockaddr_un *sun;
 253         char buf[128];
 254
 255         switch (sap->sa_family) {
 256         case AF_LOCAL:
 257                 sun = xs_addr_un(xprt);
 258                 strlcpy(buf, sun->sun_path, sizeof(buf));
 259                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 260                                                 kstrdup(buf, GFP_KERNEL);
 261                 break;
 262         case AF_INET:
 263                 (void)rpc_ntop(sap, buf, sizeof(buf));
 264                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 265                                                 kstrdup(buf, GFP_KERNEL);
 266                 sin = xs_addr_in(xprt);
 267                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 268                 break;
 269         case AF_INET6:
 270                 (void)rpc_ntop(sap, buf, sizeof(buf));
 271                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 272                                                 kstrdup(buf, GFP_KERNEL);
 273                 sin6 = xs_addr_in6(xprt);
 274                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 275                 break;
 276         default:
 277                 BUG();
 278         }
 279
 280         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 281 }
 282
 283 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 284 {
 285         struct sockaddr *sap = xs_addr(xprt);
 286         char buf[128];
 287
 288         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 289         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 290
 291         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 292         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 293 }
 294
 295 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 296                                      const char *protocol,
 297                                      const char *netid)
 298 {
 299         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 300         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 301         xs_format_common_peer_addresses(xprt);
 302         xs_format_common_peer_ports(xprt);
 303 }
 304
 305 static void xs_update_peer_port(struct rpc_xprt *xprt)
 306 {
 307         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 308         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 309
 310         xs_format_common_peer_ports(xprt);
 311 }
 312
 313 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 314 {
 315         unsigned int i;
 316
 317         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 318                 switch (i) {
 319                 case RPC_DISPLAY_PROTO:
 320                 case RPC_DISPLAY_NETID:
 321                         continue;
 322                 default:
 323                         kfree(xprt->address_strings[i]);
 324                 }
 325 }
 326
 327 static size_t
 328 xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp)
 329 {
 330         size_t i,n;
 331
 332         if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))
 333                 return want;
 334         n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;
 335         for (i = 0; i < n; i++) {
 336                 if (buf->pages[i])
 337                         continue;
 338                 buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);
 339                 if (!buf->pages[i]) {
 340                         i *= PAGE_SIZE;
 341                         return i > buf->page_base ? i - buf->page_base : 0;
 342                 }
 343         }
 344         return want;
 345 }
 346
 347 static ssize_t
 348 xs_sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags, size_t seek)
 349 {
 350         ssize_t ret;
 351         if (seek != 0)
 352                 iov_iter_advance(&msg->msg_iter, seek);
 353         ret = sock_recvmsg(sock, msg, flags);
 354         return ret > 0 ? ret + seek : ret;
 355 }
 356
 357 static ssize_t
 358 xs_read_kvec(struct socket *sock, struct msghdr *msg, int flags,
 359                 struct kvec *kvec, size_t count, size_t seek)
 360 {
 361         iov_iter_kvec(&msg->msg_iter, READ, kvec, 1, count);
 362         return xs_sock_recvmsg(sock, msg, flags, seek);
 363 }
 364
 365 static ssize_t
 366 xs_read_bvec(struct socket *sock, struct msghdr *msg, int flags,
 367                 struct bio_vec *bvec, unsigned long nr, size_t count,
 368                 size_t seek)
 369 {
 370         iov_iter_bvec(&msg->msg_iter, READ, bvec, nr, count);
 371         return xs_sock_recvmsg(sock, msg, flags, seek);
 372 }
 373
 374 static ssize_t
 375 xs_read_discard(struct socket *sock, struct msghdr *msg, int flags,
 376                 size_t count)
 377 {
 378         iov_iter_discard(&msg->msg_iter, READ, count);
 379         return sock_recvmsg(sock, msg, flags);
 380 }
 381
 382 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 383 static void
 384 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
 385 {
 386         struct bvec_iter bi = {
 387                 .bi_size = count,
 388         };
 389         struct bio_vec bv;
 390
 391         bvec_iter_advance(bvec, &bi, seek & PAGE_MASK);
 392         for_each_bvec(bv, bvec, bi, bi)
 393                 flush_dcache_page(bv.bv_page);
 394 }
 395 #else
 396 static inline void
 397 xs_flush_bvec(const struct bio_vec *bvec, size_t count, size_t seek)
 398 {
 399 }
 400 #endif
 401
 402 static ssize_t
 403 xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags,
 404                 struct xdr_buf *buf, size_t count, size_t seek, size_t *read)
 405 {
 406         size_t want, seek_init = seek, offset = 0;
 407         ssize_t ret;
 408
 409         want = min_t(size_t, count, buf->head[0].iov_len);
 410         if (seek < want) {
 411                 ret = xs_read_kvec(sock, msg, flags, &buf->head[0], want, seek);
 412                 if (ret <= 0)
 413                         goto sock_err;
 414                 offset += ret;
 415                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 416                         goto out;
 417                 if (ret != want)
 418                         goto out;
 419                 seek = 0;
 420         } else {
 421                 seek -= want;
 422                 offset += want;
 423         }
 424
 425         want = xs_alloc_sparse_pages(buf,
 426                         min_t(size_t, count - offset, buf->page_len),
 427                         GFP_KERNEL);
 428         if (seek < want) {
 429                 ret = xs_read_bvec(sock, msg, flags, buf->bvec,
 430                                 xdr_buf_pagecount(buf),
 431                                 want + buf->page_base,
 432                                 seek + buf->page_base);
 433                 if (ret <= 0)
 434                         goto sock_err;
 435                 xs_flush_bvec(buf->bvec, ret, seek + buf->page_base);
 436                 ret -= buf->page_base;
 437                 offset += ret;
 438                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 439                         goto out;
 440                 if (ret != want)
 441                         goto out;
 442                 seek = 0;
 443         } else {
 444                 seek -= want;
 445                 offset += want;
 446         }
 447
 448         want = min_t(size_t, count - offset, buf->tail[0].iov_len);
 449         if (seek < want) {
 450                 ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);
 451                 if (ret <= 0)
 452                         goto sock_err;
 453                 offset += ret;
 454                 if (offset == count || msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 455                         goto out;
 456                 if (ret != want)
 457                         goto out;
 458         } else if (offset < seek_init)
 459                 offset = seek_init;
 460         ret = -EMSGSIZE;
 461 out:
 462         *read = offset - seek_init;
 463         return ret;
 464 sock_err:
 465         offset += seek;
 466         goto out;
 467 }
 468
 469 static void
 470 xs_read_header(struct sock_xprt *transport, struct xdr_buf *buf)
 471 {
 472         if (!transport->recv.copied) {
 473                 if (buf->head[0].iov_len >= transport->recv.offset)
 474                         memcpy(buf->head[0].iov_base,
 475                                         &transport->recv.xid,
 476                                         transport->recv.offset);
 477                 transport->recv.copied = transport->recv.offset;
 478         }
 479 }
 480
 481 static bool
 482 xs_read_stream_request_done(struct sock_xprt *transport)
 483 {
 484         return transport->recv.fraghdr & cpu_to_be32(RPC_LAST_STREAM_FRAGMENT);
 485 }
 486
 487 static void
 488 xs_read_stream_check_eor(struct sock_xprt *transport,
 489                 struct msghdr *msg)
 490 {
 491         if (xs_read_stream_request_done(transport))
 492                 msg->msg_flags |= MSG_EOR;
 493 }
 494
 495 static ssize_t
 496 xs_read_stream_request(struct sock_xprt *transport, struct msghdr *msg,
 497                 int flags, struct rpc_rqst *req)
 498 {
 499         struct xdr_buf *buf = &req->rq_private_buf;
 500         size_t want, read;
 501         ssize_t ret;
 502
 503         xs_read_header(transport, buf);
 504
 505         want = transport->recv.len - transport->recv.offset;
 506         if (want != 0) {
 507                 ret = xs_read_xdr_buf(transport->sock, msg, flags, buf,
 508                                 transport->recv.copied + want,
 509                                 transport->recv.copied,
 510                                 &read);
 511                 transport->recv.offset += read;
 512                 transport->recv.copied += read;
 513         }
 514
 515         if (transport->recv.offset == transport->recv.len)
 516                 xs_read_stream_check_eor(transport, msg);
 517
 518         if (want == 0)
 519                 return 0;
 520
 521         switch (ret) {
 522         default:
 523                 break;
 524         case -EFAULT:
 525         case -EMSGSIZE:
 526                 msg->msg_flags |= MSG_TRUNC;
 527                 return read;
 528         case 0:
 529                 return -ESHUTDOWN;
 530         }
 531         return ret < 0 ? ret : read;
 532 }
 533
 534 static size_t
 535 xs_read_stream_headersize(bool isfrag)
 536 {
 537         if (isfrag)
 538                 return sizeof(__be32);
 539         return 3 * sizeof(__be32);
 540 }
 541
 542 static ssize_t
 543 xs_read_stream_header(struct sock_xprt *transport, struct msghdr *msg,
 544                 int flags, size_t want, size_t seek)
 545 {
 546         struct kvec kvec = {
 547                 .iov_base = &transport->recv.fraghdr,
 548                 .iov_len = want,
 549         };
 550         return xs_read_kvec(transport->sock, msg, flags, &kvec, want, seek);
 551 }
 552
 553 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 554 static ssize_t
 555 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
 556 {
 557         struct rpc_xprt *xprt = &transport->xprt;
 558         struct rpc_rqst *req;
 559         ssize_t ret;
 560
 561         /* Is this transport associated with the backchannel? */
 562         if (!xprt->bc_serv)
 563                 return -ESHUTDOWN;
 564
 565         /* Look up and lock the request corresponding to the given XID */
 566         req = xprt_lookup_bc_request(xprt, transport->recv.xid);
 567         if (!req) {
 568                 printk(KERN_WARNING "Callback slot table overflowed\n");
 569                 return -ESHUTDOWN;
 570         }
 571         if (transport->recv.copied && !req->rq_private_buf.len)
 572                 return -ESHUTDOWN;
 573
 574         ret = xs_read_stream_request(transport, msg, flags, req);
 575         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 576                 xprt_complete_bc_request(req, transport->recv.copied);
 577         else
 578                 req->rq_private_buf.len = transport->recv.copied;
 579
 580         return ret;
 581 }
 582 #else /* CONFIG_SUNRPC_BACKCHANNEL */
 583 static ssize_t
 584 xs_read_stream_call(struct sock_xprt *transport, struct msghdr *msg, int flags)
 585 {
 586         return -ESHUTDOWN;
 587 }
 588 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 589
 590 static ssize_t
 591 xs_read_stream_reply(struct sock_xprt *transport, struct msghdr *msg, int flags)
 592 {
 593         struct rpc_xprt *xprt = &transport->xprt;
 594         struct rpc_rqst *req;
 595         ssize_t ret = 0;
 596
 597         /* Look up and lock the request corresponding to the given XID */
 598         spin_lock(&xprt->queue_lock);
 599         req = xprt_lookup_rqst(xprt, transport->recv.xid);
 600         if (!req || (transport->recv.copied && !req->rq_private_buf.len)) {
 601                 msg->msg_flags |= MSG_TRUNC;
 602                 goto out;
 603         }
 604         xprt_pin_rqst(req);
 605         spin_unlock(&xprt->queue_lock);
 606
 607         ret = xs_read_stream_request(transport, msg, flags, req);
 608
 609         spin_lock(&xprt->queue_lock);
 610         if (msg->msg_flags & (MSG_EOR|MSG_TRUNC))
 611                 xprt_complete_rqst(req->rq_task, transport->recv.copied);
 612         else
 613                 req->rq_private_buf.len = transport->recv.copied;
 614         xprt_unpin_rqst(req);
 615 out:
 616         spin_unlock(&xprt->queue_lock);
 617         return ret;
 618 }
 619
 620 static ssize_t
 621 xs_read_stream(struct sock_xprt *transport, int flags)
 622 {
 623         struct msghdr msg = { 0 };
 624         size_t want, read = 0;
 625         ssize_t ret = 0;
 626
 627         if (transport->recv.len == 0) {
 628                 want = xs_read_stream_headersize(transport->recv.copied != 0);
 629                 ret = xs_read_stream_header(transport, &msg, flags, want,
 630                                 transport->recv.offset);
 631                 if (ret <= 0)
 632                         goto out_err;
 633                 transport->recv.offset = ret;
 634                 if (transport->recv.offset != want)
 635                         return transport->recv.offset;
 636                 transport->recv.len = be32_to_cpu(transport->recv.fraghdr) &
 637                         RPC_FRAGMENT_SIZE_MASK;
 638                 transport->recv.offset -= sizeof(transport->recv.fraghdr);
 639                 read = ret;
 640         }
 641
 642         switch (be32_to_cpu(transport->recv.calldir)) {
 643         default:
 644                 msg.msg_flags |= MSG_TRUNC;
 645                 break;
 646         case RPC_CALL:
 647                 ret = xs_read_stream_call(transport, &msg, flags);
 648                 break;
 649         case RPC_REPLY:
 650                 ret = xs_read_stream_reply(transport, &msg, flags);
 651         }
 652         if (msg.msg_flags & MSG_TRUNC) {
 653                 transport->recv.calldir = cpu_to_be32(-1);
 654                 transport->recv.copied = -1;
 655         }
 656         if (ret < 0)
 657                 goto out_err;
 658         read += ret;
 659         if (transport->recv.offset < transport->recv.len) {
 660                 if (!(msg.msg_flags & MSG_TRUNC))
 661                         return read;
 662                 msg.msg_flags = 0;
 663                 ret = xs_read_discard(transport->sock, &msg, flags,
 664                                 transport->recv.len - transport->recv.offset);
 665                 if (ret <= 0)
 666                         goto out_err;
 667                 transport->recv.offset += ret;
 668                 read += ret;
 669                 if (transport->recv.offset != transport->recv.len)
 670                         return read;
 671         }
 672         if (xs_read_stream_request_done(transport)) {
 673                 trace_xs_stream_read_request(transport);
 674                 transport->recv.copied = 0;
 675         }
 676         transport->recv.offset = 0;
 677         transport->recv.len = 0;
 678         return read;
 679 out_err:
 680         return ret != 0 ? ret : -ESHUTDOWN;
 681 }
 682
 683 static __poll_t xs_poll_socket(struct sock_xprt *transport)
 684 {
 685         return transport->sock->ops->poll(transport->file, transport->sock,
 686                         NULL);
 687 }
 688
 689 static bool xs_poll_socket_readable(struct sock_xprt *transport)
 690 {
 691         __poll_t events = xs_poll_socket(transport);
 692
 693         return (events & (EPOLLIN | EPOLLRDNORM)) && !(events & EPOLLRDHUP);
 694 }
 695
 696 static void xs_poll_check_readable(struct sock_xprt *transport)
 697 {
 698
 699         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
 700         if (!xs_poll_socket_readable(transport))
 701                 return;
 702         if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
 703                 queue_work(xprtiod_workqueue, &transport->recv_worker);
 704 }
 705
 706 static void xs_stream_data_receive(struct sock_xprt *transport)
 707 {
 708         size_t read = 0;
 709         ssize_t ret = 0;
 710
 711         mutex_lock(&transport->recv_mutex);
 712         if (transport->sock == NULL)
 713                 goto out;
 714         for (;;) {
 715                 ret = xs_read_stream(transport, MSG_DONTWAIT);
 716                 if (ret < 0)
 717                         break;
 718                 read += ret;
 719                 cond_resched();
 720         }
 721         if (ret == -ESHUTDOWN)
 722                 kernel_sock_shutdown(transport->sock, SHUT_RDWR);
 723         else
 724                 xs_poll_check_readable(transport);
 725 out:
 726         mutex_unlock(&transport->recv_mutex);
 727         trace_xs_stream_read_data(&transport->xprt, ret, read);
 728 }
 729
 730 static void xs_stream_data_receive_workfn(struct work_struct *work)
 731 {
 732         struct sock_xprt *transport =
 733                 container_of(work, struct sock_xprt, recv_worker);
 734         unsigned int pflags = memalloc_nofs_save();
 735
 736         xs_stream_data_receive(transport);
 737         memalloc_nofs_restore(pflags);
 738 }
 739
 740 static void
 741 xs_stream_reset_connect(struct sock_xprt *transport)
 742 {
 743         transport->recv.offset = 0;
 744         transport->recv.len = 0;
 745         transport->recv.copied = 0;
 746         transport->xmit.offset = 0;
 747 }
 748
 749 static void
 750 xs_stream_start_connect(struct sock_xprt *transport)
 751 {
 752         transport->xprt.stat.connect_count++;
 753         transport->xprt.stat.connect_start = jiffies;
 754 }
 755
 756 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 757
 758 /**
 759  * xs_nospace - handle transmit was incomplete
 760  * @req: pointer to RPC request
 761  *
 762  */
 763 static int xs_nospace(struct rpc_rqst *req)
 764 {
 765         struct rpc_xprt *xprt = req->rq_xprt;
 766         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 767         struct sock *sk = transport->inet;
 768         int ret = -EAGAIN;
 769
 770         trace_rpc_socket_nospace(req, transport);
 771
 772         /* Protect against races with write_space */
 773         spin_lock(&xprt->transport_lock);
 774
 775         /* Don't race with disconnect */
 776         if (xprt_connected(xprt)) {
 777                 /* wait for more buffer space */
 778                 sk->sk_write_pending++;
 779                 xprt_wait_for_buffer_space(xprt);
 780         } else
 781                 ret = -ENOTCONN;
 782
 783         spin_unlock(&xprt->transport_lock);
 784
 785         /* Race breaker in case memory is freed before above code is called */
 786         if (ret == -EAGAIN) {
 787                 struct socket_wq *wq;
 788
 789                 rcu_read_lock();
 790                 wq = rcu_dereference(sk->sk_wq);
 791                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
 792                 rcu_read_unlock();
 793
 794                 sk->sk_write_space(sk);
 795         }
 796         return ret;
 797 }
 798
 799 static void
 800 xs_stream_prepare_request(struct rpc_rqst *req)
 801 {
 802         xdr_free_bvec(&req->rq_rcv_buf);
 803         req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf, GFP_KERNEL);
 804 }
 805
 806 /*
 807  * Determine if the previous message in the stream was aborted before it
 808  * could complete transmission.
 809  */
 810 static bool
 811 xs_send_request_was_aborted(struct sock_xprt *transport, struct rpc_rqst *req)
 812 {
 813         return transport->xmit.offset != 0 && req->rq_bytes_sent == 0;
 814 }
 815
 816 /*
 817  * Return the stream record marker field for a record of length < 2^31-1
 818  */
 819 static rpc_fraghdr
 820 xs_stream_record_marker(struct xdr_buf *xdr)
 821 {
 822         if (!xdr->len)
 823                 return 0;
 824         return cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | (u32)xdr->len);
 825 }
 826
 827 /**
 828  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 829  * @req: pointer to RPC request
 830  *
 831  * Return values:
 832  *        0:    The request has been sent
 833  *   EAGAIN:    The socket was blocked, please call again later to
 834  *              complete the request
 835  * ENOTCONN:    Caller needs to invoke connect logic then call again
 836  *    other:    Some other error occurred, the request was not sent
 837  */
 838 static int xs_local_send_request(struct rpc_rqst *req)
 839 {
 840         struct rpc_xprt *xprt = req->rq_xprt;
 841         struct sock_xprt *transport =
 842                                 container_of(xprt, struct sock_xprt, xprt);
 843         struct xdr_buf *xdr = &req->rq_snd_buf;
 844         rpc_fraghdr rm = xs_stream_record_marker(xdr);
 845         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
 846         struct msghdr msg = {
 847                 .msg_flags      = XS_SENDMSG_FLAGS,
 848         };
 849         unsigned int sent;
 850         int status;
 851
 852         /* Close the stream if the previous transmission was incomplete */
 853         if (xs_send_request_was_aborted(transport, req)) {
 854                 xs_close(xprt);
 855                 return -ENOTCONN;
 856         }
 857
 858         xs_pktdump("packet data:",
 859                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 860
 861         req->rq_xtime = ktime_get();
 862         status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
 863                                    transport->xmit.offset, rm, &sent);
 864         dprintk("RPC:       %s(%u) = %d\n",
 865                         __func__, xdr->len - transport->xmit.offset, status);
 866
 867         if (status == -EAGAIN && sock_writeable(transport->inet))
 868                 status = -ENOBUFS;
 869
 870         if (likely(sent > 0) || status == 0) {
 871                 transport->xmit.offset += sent;
 872                 req->rq_bytes_sent = transport->xmit.offset;
 873                 if (likely(req->rq_bytes_sent >= msglen)) {
 874                         req->rq_xmit_bytes_sent += transport->xmit.offset;
 875                         transport->xmit.offset = 0;
 876                         return 0;
 877                 }
 878                 status = -EAGAIN;
 879         }
 880
 881         switch (status) {
 882         case -ENOBUFS:
 883                 break;
 884         case -EAGAIN:
 885                 status = xs_nospace(req);
 886                 break;
 887         default:
 888                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 889                         -status);
 890                 fallthrough;
 891         case -EPIPE:
 892                 xs_close(xprt);
 893                 status = -ENOTCONN;
 894         }
 895
 896         return status;
 897 }
 898
 899 /**
 900  * xs_udp_send_request - write an RPC request to a UDP socket
 901  * @req: pointer to RPC request
 902  *
 903  * Return values:
 904  *        0:    The request has been sent
 905  *   EAGAIN:    The socket was blocked, please call again later to
 906  *              complete the request
 907  * ENOTCONN:    Caller needs to invoke connect logic then call again
 908  *    other:    Some other error occurred, the request was not sent
 909  */
 910 static int xs_udp_send_request(struct rpc_rqst *req)
 911 {
 912         struct rpc_xprt *xprt = req->rq_xprt;
 913         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 914         struct xdr_buf *xdr = &req->rq_snd_buf;
 915         struct msghdr msg = {
 916                 .msg_name       = xs_addr(xprt),
 917                 .msg_namelen    = xprt->addrlen,
 918                 .msg_flags      = XS_SENDMSG_FLAGS,
 919         };
 920         unsigned int sent;
 921         int status;
 922
 923         xs_pktdump("packet data:",
 924                                 req->rq_svec->iov_base,
 925                                 req->rq_svec->iov_len);
 926
 927         if (!xprt_bound(xprt))
 928                 return -ENOTCONN;
 929
 930         if (!xprt_request_get_cong(xprt, req))
 931                 return -EBADSLT;
 932
 933         req->rq_xtime = ktime_get();
 934         status = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, 0, &sent);
 935
 936         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 937                         xdr->len, status);
 938
 939         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
 940         if (status == -EPERM)
 941                 goto process_status;
 942
 943         if (status == -EAGAIN && sock_writeable(transport->inet))
 944                 status = -ENOBUFS;
 945
 946         if (sent > 0 || status == 0) {
 947                 req->rq_xmit_bytes_sent += sent;
 948                 if (sent >= req->rq_slen)
 949                         return 0;
 950                 /* Still some bytes left; set up for a retry later. */
 951                 status = -EAGAIN;
 952         }
 953
 954 process_status:
 955         switch (status) {
 956         case -ENOTSOCK:
 957                 status = -ENOTCONN;
 958                 /* Should we call xs_close() here? */
 959                 break;
 960         case -EAGAIN:
 961                 status = xs_nospace(req);
 962                 break;
 963         case -ENETUNREACH:
 964         case -ENOBUFS:
 965         case -EPIPE:
 966         case -ECONNREFUSED:
 967         case -EPERM:
 968                 /* When the server has died, an ICMP port unreachable message
 969                  * prompts ECONNREFUSED. */
 970                 break;
 971         default:
 972                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 973                         -status);
 974         }
 975
 976         return status;
 977 }
 978
 979 /**
 980  * xs_tcp_send_request - write an RPC request to a TCP socket
 981  * @req: pointer to RPC request
 982  *
 983  * Return values:
 984  *        0:    The request has been sent
 985  *   EAGAIN:    The socket was blocked, please call again later to
 986  *              complete the request
 987  * ENOTCONN:    Caller needs to invoke connect logic then call again
 988  *    other:    Some other error occurred, the request was not sent
 989  *
 990  * XXX: In the case of soft timeouts, should we eventually give up
 991  *      if sendmsg is not able to make progress?
 992  */
 993 static int xs_tcp_send_request(struct rpc_rqst *req)
 994 {
 995         struct rpc_xprt *xprt = req->rq_xprt;
 996         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 997         struct xdr_buf *xdr = &req->rq_snd_buf;
 998         rpc_fraghdr rm = xs_stream_record_marker(xdr);
 999         unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
1000         struct msghdr msg = {
1001                 .msg_flags      = XS_SENDMSG_FLAGS,
1002         };
1003         bool vm_wait = false;
1004         unsigned int sent;
1005         int status;
1006
1007         /* Close the stream if the previous transmission was incomplete */
1008         if (xs_send_request_was_aborted(transport, req)) {
1009                 if (transport->sock != NULL)
1010                         kernel_sock_shutdown(transport->sock, SHUT_RDWR);
1011                 return -ENOTCONN;
1012         }
1013
1014         xs_pktdump("packet data:",
1015                                 req->rq_svec->iov_base,
1016                                 req->rq_svec->iov_len);
1017
1018         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
1019                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
1020
1021         /* Continue transmitting the packet/record. We must be careful
1022          * to cope with writespace callbacks arriving _after_ we have
1023          * called sendmsg(). */
1024         req->rq_xtime = ktime_get();
1025         tcp_sock_set_cork(transport->inet, true);
1026         while (1) {
1027                 status = xprt_sock_sendmsg(transport->sock, &msg, xdr,
1028                                            transport->xmit.offset, rm, &sent);
1029
1030                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
1031                                 xdr->len - transport->xmit.offset, status);
1032
1033                 /* If we've sent the entire packet, immediately
1034                  * reset the count of bytes sent. */
1035                 transport->xmit.offset += sent;
1036                 req->rq_bytes_sent = transport->xmit.offset;
1037                 if (likely(req->rq_bytes_sent >= msglen)) {
1038                         req->rq_xmit_bytes_sent += transport->xmit.offset;
1039                         transport->xmit.offset = 0;
1040                         if (atomic_long_read(&xprt->xmit_queuelen) == 1)
1041                                 tcp_sock_set_cork(transport->inet, false);
1042                         return 0;
1043                 }
1044
1045                 WARN_ON_ONCE(sent == 0 && status == 0);
1046
1047                 if (status == -EAGAIN ) {
1048                         /*
1049                          * Return EAGAIN if we're sure we're hitting the
1050                          * socket send buffer limits.
1051                          */
1052                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
1053                                 break;
1054                         /*
1055                          * Did we hit a memory allocation failure?
1056                          */
1057                         if (sent == 0) {
1058                                 status = -ENOBUFS;
1059                                 if (vm_wait)
1060                                         break;
1061                                 /* Retry, knowing now that we're below the
1062                                  * socket send buffer limit
1063                                  */
1064                                 vm_wait = true;
1065                         }
1066                         continue;
1067                 }
1068                 if (status < 0)
1069                         break;
1070                 vm_wait = false;
1071         }
1072
1073         switch (status) {
1074         case -ENOTSOCK:
1075                 status = -ENOTCONN;
1076                 /* Should we call xs_close() here? */
1077                 break;
1078         case -EAGAIN:
1079                 status = xs_nospace(req);
1080                 break;
1081         case -ECONNRESET:
1082         case -ECONNREFUSED:
1083         case -ENOTCONN:
1084         case -EADDRINUSE:
1085         case -ENOBUFS:
1086         case -EPIPE:
1087                 break;
1088         default:
1089                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
1090                         -status);
1091         }
1092
1093         return status;
1094 }
1095
1096 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1097 {
1098         transport->old_data_ready = sk->sk_data_ready;
1099         transport->old_state_change = sk->sk_state_change;
1100         transport->old_write_space = sk->sk_write_space;
1101         transport->old_error_report = sk->sk_error_report;
1102 }
1103
1104 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
1105 {
1106         sk->sk_data_ready = transport->old_data_ready;
1107         sk->sk_state_change = transport->old_state_change;
1108         sk->sk_write_space = transport->old_write_space;
1109         sk->sk_error_report = transport->old_error_report;
1110 }
1111
1112 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
1113 {
1114         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1115
1116         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1117         clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state);
1118         clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state);
1119         clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state);
1120 }
1121
1122 static void xs_run_error_worker(struct sock_xprt *transport, unsigned int nr)
1123 {
1124         set_bit(nr, &transport->sock_state);
1125         queue_work(xprtiod_workqueue, &transport->error_worker);
1126 }
1127
1128 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1129 {
1130         smp_mb__before_atomic();
1131         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1132         clear_bit(XPRT_CLOSING, &xprt->state);
1133         xs_sock_reset_state_flags(xprt);
1134         smp_mb__after_atomic();
1135 }
1136
1137 /**
1138  * xs_error_report - callback to handle TCP socket state errors
1139  * @sk: socket
1140  *
1141  * Note: we don't call sock_error() since there may be a rpc_task
1142  * using the socket, and so we don't want to clear sk->sk_err.
1143  */
1144 static void xs_error_report(struct sock *sk)
1145 {
1146         struct sock_xprt *transport;
1147         struct rpc_xprt *xprt;
1148
1149         read_lock_bh(&sk->sk_callback_lock);
1150         if (!(xprt = xprt_from_sock(sk)))
1151                 goto out;
1152
1153         transport = container_of(xprt, struct sock_xprt, xprt);
1154         transport->xprt_err = -sk->sk_err;
1155         if (transport->xprt_err == 0)
1156                 goto out;
1157         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
1158                         xprt, -transport->xprt_err);
1159         trace_rpc_socket_error(xprt, sk->sk_socket, transport->xprt_err);
1160
1161         /* barrier ensures xprt_err is set before XPRT_SOCK_WAKE_ERROR */
1162         smp_mb__before_atomic();
1163         xs_run_error_worker(transport, XPRT_SOCK_WAKE_ERROR);
1164  out:
1165         read_unlock_bh(&sk->sk_callback_lock);
1166 }
1167
1168 static void xs_reset_transport(struct sock_xprt *transport)
1169 {
1170         struct socket *sock = transport->sock;
1171         struct sock *sk = transport->inet;
1172         struct rpc_xprt *xprt = &transport->xprt;
1173         struct file *filp = transport->file;
1174
1175         if (sk == NULL)
1176                 return;
1177
1178         if (atomic_read(&transport->xprt.swapper))
1179                 sk_clear_memalloc(sk);
1180
1181         kernel_sock_shutdown(sock, SHUT_RDWR);
1182
1183         mutex_lock(&transport->recv_mutex);
1184         write_lock_bh(&sk->sk_callback_lock);
1185         transport->inet = NULL;
1186         transport->sock = NULL;
1187         transport->file = NULL;
1188
1189         sk->sk_user_data = NULL;
1190
1191         xs_restore_old_callbacks(transport, sk);
1192         xprt_clear_connected(xprt);
1193         write_unlock_bh(&sk->sk_callback_lock);
1194         xs_sock_reset_connection_flags(xprt);
1195         /* Reset stream record info */
1196         xs_stream_reset_connect(transport);
1197         mutex_unlock(&transport->recv_mutex);
1198
1199         trace_rpc_socket_close(xprt, sock);
1200         fput(filp);
1201
1202         xprt_disconnect_done(xprt);
1203 }
1204
1205 /**
1206  * xs_close - close a socket
1207  * @xprt: transport
1208  *
1209  * This is used when all requests are complete; ie, no DRC state remains
1210  * on the server we want to save.
1211  *
1212  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
1213  * xs_reset_transport() zeroing the socket from underneath a writer.
1214  */
1215 static void xs_close(struct rpc_xprt *xprt)
1216 {
1217         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1218
1219         dprintk("RPC:       xs_close xprt %p\n", xprt);
1220
1221         xs_reset_transport(transport);
1222         xprt->reestablish_timeout = 0;
1223 }
1224
1225 static void xs_inject_disconnect(struct rpc_xprt *xprt)
1226 {
1227         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
1228                 xprt);
1229         xprt_disconnect_done(xprt);
1230 }
1231
1232 static void xs_xprt_free(struct rpc_xprt *xprt)
1233 {
1234         xs_free_peer_addresses(xprt);
1235         xprt_free(xprt);
1236 }
1237
1238 /**
1239  * xs_destroy - prepare to shutdown a transport
1240  * @xprt: doomed transport
1241  *
1242  */
1243 static void xs_destroy(struct rpc_xprt *xprt)
1244 {
1245         struct sock_xprt *transport = container_of(xprt,
1246                         struct sock_xprt, xprt);
1247         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
1248
1249         cancel_delayed_work_sync(&transport->connect_worker);
1250         xs_close(xprt);
1251         cancel_work_sync(&transport->recv_worker);
1252         cancel_work_sync(&transport->error_worker);
1253         xs_xprt_free(xprt);
1254         module_put(THIS_MODULE);
1255 }
1256
1257 /**
1258  * xs_udp_data_read_skb - receive callback for UDP sockets
1259  * @xprt: transport
1260  * @sk: socket
1261  * @skb: skbuff
1262  *
1263  */
1264 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1265                 struct sock *sk,
1266                 struct sk_buff *skb)
1267 {
1268         struct rpc_task *task;
1269         struct rpc_rqst *rovr;
1270         int repsize, copied;
1271         u32 _xid;
1272         __be32 *xp;
1273
1274         repsize = skb->len;
1275         if (repsize < 4) {
1276                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1277                 return;
1278         }
1279
1280         /* Copy the XID from the skb... */
1281         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1282         if (xp == NULL)
1283                 return;
1284
1285         /* Look up and lock the request corresponding to the given XID */
1286         spin_lock(&xprt->queue_lock);
1287         rovr = xprt_lookup_rqst(xprt, *xp);
1288         if (!rovr)
1289                 goto out_unlock;
1290         xprt_pin_rqst(rovr);
1291         xprt_update_rtt(rovr->rq_task);
1292         spin_unlock(&xprt->queue_lock);
1293         task = rovr->rq_task;
1294
1295         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1296                 copied = repsize;
1297
1298         /* Suck it into the iovec, verify checksum if not done by hw. */
1299         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1300                 spin_lock(&xprt->queue_lock);
1301                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1302                 goto out_unpin;
1303         }
1304
1305
1306         spin_lock(&xprt->transport_lock);
1307         xprt_adjust_cwnd(xprt, task, copied);
1308         spin_unlock(&xprt->transport_lock);
1309         spin_lock(&xprt->queue_lock);
1310         xprt_complete_rqst(task, copied);
1311         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1312 out_unpin:
1313         xprt_unpin_rqst(rovr);
1314  out_unlock:
1315         spin_unlock(&xprt->queue_lock);
1316 }
1317
1318 static void xs_udp_data_receive(struct sock_xprt *transport)
1319 {
1320         struct sk_buff *skb;
1321         struct sock *sk;
1322         int err;
1323
1324         mutex_lock(&transport->recv_mutex);
1325         sk = transport->inet;
1326         if (sk == NULL)
1327                 goto out;
1328         for (;;) {
1329                 skb = skb_recv_udp(sk, 0, 1, &err);
1330                 if (skb == NULL)
1331                         break;
1332                 xs_udp_data_read_skb(&transport->xprt, sk, skb);
1333                 consume_skb(skb);
1334                 cond_resched();
1335         }
1336         xs_poll_check_readable(transport);
1337 out:
1338         mutex_unlock(&transport->recv_mutex);
1339 }
1340
1341 static void xs_udp_data_receive_workfn(struct work_struct *work)
1342 {
1343         struct sock_xprt *transport =
1344                 container_of(work, struct sock_xprt, recv_worker);
1345         unsigned int pflags = memalloc_nofs_save();
1346
1347         xs_udp_data_receive(transport);
1348         memalloc_nofs_restore(pflags);
1349 }
1350
1351 /**
1352  * xs_data_ready - "data ready" callback for UDP sockets
1353  * @sk: socket with data to read
1354  *
1355  */
1356 static void xs_data_ready(struct sock *sk)
1357 {
1358         struct rpc_xprt *xprt;
1359
1360         read_lock_bh(&sk->sk_callback_lock);
1361         dprintk("RPC:       xs_data_ready...\n");
1362         xprt = xprt_from_sock(sk);
1363         if (xprt != NULL) {
1364                 struct sock_xprt *transport = container_of(xprt,
1365                                 struct sock_xprt, xprt);
1366                 transport->old_data_ready(sk);
1367                 /* Any data means we had a useful conversation, so
1368                  * then we don't need to delay the next reconnect
1369                  */
1370                 if (xprt->reestablish_timeout)
1371                         xprt->reestablish_timeout = 0;
1372                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1373                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1374         }
1375         read_unlock_bh(&sk->sk_callback_lock);
1376 }
1377
1378 /*
1379  * Helper function to force a TCP close if the server is sending
1380  * junk and/or it has put us in CLOSE_WAIT
1381  */
1382 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1383 {
1384         xprt_force_disconnect(xprt);
1385 }
1386
1387 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1388 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1389 {
1390         return PAGE_SIZE;
1391 }
1392 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1393
1394 /**
1395  * xs_tcp_state_change - callback to handle TCP socket state changes
1396  * @sk: socket whose state has changed
1397  *
1398  */
1399 static void xs_tcp_state_change(struct sock *sk)
1400 {
1401         struct rpc_xprt *xprt;
1402         struct sock_xprt *transport;
1403
1404         read_lock_bh(&sk->sk_callback_lock);
1405         if (!(xprt = xprt_from_sock(sk)))
1406                 goto out;
1407         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1408         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1409                         sk->sk_state, xprt_connected(xprt),
1410                         sock_flag(sk, SOCK_DEAD),
1411                         sock_flag(sk, SOCK_ZAPPED),
1412                         sk->sk_shutdown);
1413
1414         transport = container_of(xprt, struct sock_xprt, xprt);
1415         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1416         switch (sk->sk_state) {
1417         case TCP_ESTABLISHED:
1418                 if (!xprt_test_and_set_connected(xprt)) {
1419                         xprt->connect_cookie++;
1420                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1421                         xprt_clear_connecting(xprt);
1422
1423                         xprt->stat.connect_count++;
1424                         xprt->stat.connect_time += (long)jiffies -
1425                                                    xprt->stat.connect_start;
1426                         xs_run_error_worker(transport, XPRT_SOCK_WAKE_PENDING);
1427                 }
1428                 break;
1429         case TCP_FIN_WAIT1:
1430                 /* The client initiated a shutdown of the socket */
1431                 xprt->connect_cookie++;
1432                 xprt->reestablish_timeout = 0;
1433                 set_bit(XPRT_CLOSING, &xprt->state);
1434                 smp_mb__before_atomic();
1435                 clear_bit(XPRT_CONNECTED, &xprt->state);
1436                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1437                 smp_mb__after_atomic();
1438                 break;
1439         case TCP_CLOSE_WAIT:
1440                 /* The server initiated a shutdown of the socket */
1441                 xprt->connect_cookie++;
1442                 clear_bit(XPRT_CONNECTED, &xprt->state);
1443                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1444                 fallthrough;
1445         case TCP_CLOSING:
1446                 /*
1447                  * If the server closed down the connection, make sure that
1448                  * we back off before reconnecting
1449                  */
1450                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1451                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1452                 break;
1453         case TCP_LAST_ACK:
1454                 set_bit(XPRT_CLOSING, &xprt->state);
1455                 smp_mb__before_atomic();
1456                 clear_bit(XPRT_CONNECTED, &xprt->state);
1457                 smp_mb__after_atomic();
1458                 break;
1459         case TCP_CLOSE:
1460                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1461                                         &transport->sock_state))
1462                         xprt_clear_connecting(xprt);
1463                 clear_bit(XPRT_CLOSING, &xprt->state);
1464                 /* Trigger the socket release */
1465                 xs_run_error_worker(transport, XPRT_SOCK_WAKE_DISCONNECT);
1466         }
1467  out:
1468         read_unlock_bh(&sk->sk_callback_lock);
1469 }
1470
1471 static void xs_write_space(struct sock *sk)
1472 {
1473         struct socket_wq *wq;
1474         struct sock_xprt *transport;
1475         struct rpc_xprt *xprt;
1476
1477         if (!sk->sk_socket)
1478                 return;
1479         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1480
1481         if (unlikely(!(xprt = xprt_from_sock(sk))))
1482                 return;
1483         transport = container_of(xprt, struct sock_xprt, xprt);
1484         rcu_read_lock();
1485         wq = rcu_dereference(sk->sk_wq);
1486         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1487                 goto out;
1488
1489         xs_run_error_worker(transport, XPRT_SOCK_WAKE_WRITE);
1490         sk->sk_write_pending--;
1491 out:
1492         rcu_read_unlock();
1493 }
1494
1495 /**
1496  * xs_udp_write_space - callback invoked when socket buffer space
1497  *                             becomes available
1498  * @sk: socket whose state has changed
1499  *
1500  * Called when more output buffer space is available for this socket.
1501  * We try not to wake our writers until they can make "significant"
1502  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1503  * with a bunch of small requests.
1504  */
1505 static void xs_udp_write_space(struct sock *sk)
1506 {
1507         read_lock_bh(&sk->sk_callback_lock);
1508
1509         /* from net/core/sock.c:sock_def_write_space */
1510         if (sock_writeable(sk))
1511                 xs_write_space(sk);
1512
1513         read_unlock_bh(&sk->sk_callback_lock);
1514 }
1515
1516 /**
1517  * xs_tcp_write_space - callback invoked when socket buffer space
1518  *                             becomes available
1519  * @sk: socket whose state has changed
1520  *
1521  * Called when more output buffer space is available for this socket.
1522  * We try not to wake our writers until they can make "significant"
1523  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1524  * with a bunch of small requests.
1525  */
1526 static void xs_tcp_write_space(struct sock *sk)
1527 {
1528         read_lock_bh(&sk->sk_callback_lock);
1529
1530         /* from net/core/stream.c:sk_stream_write_space */
1531         if (sk_stream_is_writeable(sk))
1532                 xs_write_space(sk);
1533
1534         read_unlock_bh(&sk->sk_callback_lock);
1535 }
1536
1537 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1538 {
1539         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1540         struct sock *sk = transport->inet;
1541
1542         if (transport->rcvsize) {
1543                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1544                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1545         }
1546         if (transport->sndsize) {
1547                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1548                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1549                 sk->sk_write_space(sk);
1550         }
1551 }
1552
1553 /**
1554  * xs_udp_set_buffer_size - set send and receive limits
1555  * @xprt: generic transport
1556  * @sndsize: requested size of send buffer, in bytes
1557  * @rcvsize: requested size of receive buffer, in bytes
1558  *
1559  * Set socket send and receive buffer size limits.
1560  */
1561 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1562 {
1563         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1564
1565         transport->sndsize = 0;
1566         if (sndsize)
1567                 transport->sndsize = sndsize + 1024;
1568         transport->rcvsize = 0;
1569         if (rcvsize)
1570                 transport->rcvsize = rcvsize + 1024;
1571
1572         xs_udp_do_set_buffer_size(xprt);
1573 }
1574
1575 /**
1576  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1577  * @xprt: controlling transport
1578  * @task: task that timed out
1579  *
1580  * Adjust the congestion window after a retransmit timeout has occurred.
1581  */
1582 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1583 {
1584         spin_lock(&xprt->transport_lock);
1585         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1586         spin_unlock(&xprt->transport_lock);
1587 }
1588
1589 static int xs_get_random_port(void)
1590 {
1591         unsigned short min = xprt_min_resvport, max = xprt_max_resvport;
1592         unsigned short range;
1593         unsigned short rand;
1594
1595         if (max < min)
1596                 return -EADDRINUSE;
1597         range = max - min + 1;
1598         rand = (unsigned short) prandom_u32() % range;
1599         return rand + min;
1600 }
1601
1602 static unsigned short xs_sock_getport(struct socket *sock)
1603 {
1604         struct sockaddr_storage buf;
1605         unsigned short port = 0;
1606
1607         if (kernel_getsockname(sock, (struct sockaddr *)&buf) < 0)
1608                 goto out;
1609         switch (buf.ss_family) {
1610         case AF_INET6:
1611                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1612                 break;
1613         case AF_INET:
1614                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1615         }
1616 out:
1617         return port;
1618 }
1619
1620 /**
1621  * xs_set_port - reset the port number in the remote endpoint address
1622  * @xprt: generic transport
1623  * @port: new port number
1624  *
1625  */
1626 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1627 {
1628         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1629
1630         rpc_set_port(xs_addr(xprt), port);
1631         xs_update_peer_port(xprt);
1632 }
1633
1634 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1635 {
1636         if (transport->srcport == 0 && transport->xprt.reuseport)
1637                 transport->srcport = xs_sock_getport(sock);
1638 }
1639
1640 static int xs_get_srcport(struct sock_xprt *transport)
1641 {
1642         int port = transport->srcport;
1643
1644         if (port == 0 && transport->xprt.resvport)
1645                 port = xs_get_random_port();
1646         return port;
1647 }
1648
1649 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1650 {
1651         if (transport->srcport != 0)
1652                 transport->srcport = 0;
1653         if (!transport->xprt.resvport)
1654                 return 0;
1655         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1656                 return xprt_max_resvport;
1657         return --port;
1658 }
1659 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1660 {
1661         struct sockaddr_storage myaddr;
1662         int err, nloop = 0;
1663         int port = xs_get_srcport(transport);
1664         unsigned short last;
1665
1666         /*
1667          * If we are asking for any ephemeral port (i.e. port == 0 &&
1668          * transport->xprt.resvport == 0), don't bind.  Let the local
1669          * port selection happen implicitly when the socket is used
1670          * (for example at connect time).
1671          *
1672          * This ensures that we can continue to establish TCP
1673          * connections even when all local ephemeral ports are already
1674          * a part of some TCP connection.  This makes no difference
1675          * for UDP sockets, but also doesn't harm them.
1676          *
1677          * If we're asking for any reserved port (i.e. port == 0 &&
1678          * transport->xprt.resvport == 1) xs_get_srcport above will
1679          * ensure that port is non-zero and we will bind as needed.
1680          */
1681         if (port <= 0)
1682                 return port;
1683
1684         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1685         do {
1686                 rpc_set_port((struct sockaddr *)&myaddr, port);
1687                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1688                                 transport->xprt.addrlen);
1689                 if (err == 0) {
1690                         transport->srcport = port;
1691                         break;
1692                 }
1693                 last = port;
1694                 port = xs_next_srcport(transport, port);
1695                 if (port > last)
1696                         nloop++;
1697         } while (err == -EADDRINUSE && nloop != 2);
1698
1699         if (myaddr.ss_family == AF_INET)
1700                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1701                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1702                                 port, err ? "failed" : "ok", err);
1703         else
1704                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1705                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1706                                 port, err ? "failed" : "ok", err);
1707         return err;
1708 }
1709
1710 /*
1711  * We don't support autobind on AF_LOCAL sockets
1712  */
1713 static void xs_local_rpcbind(struct rpc_task *task)
1714 {
1715         xprt_set_bound(task->tk_xprt);
1716 }
1717
1718 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1719 {
1720 }
1721
1722 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1723 static struct lock_class_key xs_key[2];
1724 static struct lock_class_key xs_slock_key[2];
1725
1726 static inline void xs_reclassify_socketu(struct socket *sock)
1727 {
1728         struct sock *sk = sock->sk;
1729
1730         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1731                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1732 }
1733
1734 static inline void xs_reclassify_socket4(struct socket *sock)
1735 {
1736         struct sock *sk = sock->sk;
1737
1738         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1739                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1740 }
1741
1742 static inline void xs_reclassify_socket6(struct socket *sock)
1743 {
1744         struct sock *sk = sock->sk;
1745
1746         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1747                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1748 }
1749
1750 static inline void xs_reclassify_socket(int family, struct socket *sock)
1751 {
1752         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1753                 return;
1754
1755         switch (family) {
1756         case AF_LOCAL:
1757                 xs_reclassify_socketu(sock);
1758                 break;
1759         case AF_INET:
1760                 xs_reclassify_socket4(sock);
1761                 break;
1762         case AF_INET6:
1763                 xs_reclassify_socket6(sock);
1764                 break;
1765         }
1766 }
1767 #else
1768 static inline void xs_reclassify_socket(int family, struct socket *sock)
1769 {
1770 }
1771 #endif
1772
1773 static void xs_dummy_setup_socket(struct work_struct *work)
1774 {
1775 }
1776
1777 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1778                 struct sock_xprt *transport, int family, int type,
1779                 int protocol, bool reuseport)
1780 {
1781         struct file *filp;
1782         struct socket *sock;
1783         int err;
1784
1785         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1786         if (err < 0) {
1787                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1788                                 protocol, -err);
1789                 goto out;
1790         }
1791         xs_reclassify_socket(family, sock);
1792
1793         if (reuseport)
1794                 sock_set_reuseport(sock->sk);
1795
1796         err = xs_bind(transport, sock);
1797         if (err) {
1798                 sock_release(sock);
1799                 goto out;
1800         }
1801
1802         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1803         if (IS_ERR(filp))
1804                 return ERR_CAST(filp);
1805         transport->file = filp;
1806
1807         return sock;
1808 out:
1809         return ERR_PTR(err);
1810 }
1811
1812 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1813                                       struct socket *sock)
1814 {
1815         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1816                                                                         xprt);
1817
1818         if (!transport->inet) {
1819                 struct sock *sk = sock->sk;
1820
1821                 write_lock_bh(&sk->sk_callback_lock);
1822
1823                 xs_save_old_callbacks(transport, sk);
1824
1825                 sk->sk_user_data = xprt;
1826                 sk->sk_data_ready = xs_data_ready;
1827                 sk->sk_write_space = xs_udp_write_space;
1828                 sock_set_flag(sk, SOCK_FASYNC);
1829                 sk->sk_error_report = xs_error_report;
1830
1831                 xprt_clear_connected(xprt);
1832
1833                 /* Reset to new socket */
1834                 transport->sock = sock;
1835                 transport->inet = sk;
1836
1837                 write_unlock_bh(&sk->sk_callback_lock);
1838         }
1839
1840         xs_stream_start_connect(transport);
1841
1842         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1843 }
1844
1845 /**
1846  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1847  * @transport: socket transport to connect
1848  */
1849 static int xs_local_setup_socket(struct sock_xprt *transport)
1850 {
1851         struct rpc_xprt *xprt = &transport->xprt;
1852         struct file *filp;
1853         struct socket *sock;
1854         int status;
1855
1856         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1857                                         SOCK_STREAM, 0, &sock, 1);
1858         if (status < 0) {
1859                 dprintk("RPC:       can't create AF_LOCAL "
1860                         "transport socket (%d).\n", -status);
1861                 goto out;
1862         }
1863         xs_reclassify_socket(AF_LOCAL, sock);
1864
1865         filp = sock_alloc_file(sock, O_NONBLOCK, NULL);
1866         if (IS_ERR(filp)) {
1867                 status = PTR_ERR(filp);
1868                 goto out;
1869         }
1870         transport->file = filp;
1871
1872         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1873                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1874
1875         status = xs_local_finish_connecting(xprt, sock);
1876         trace_rpc_socket_connect(xprt, sock, status);
1877         switch (status) {
1878         case 0:
1879                 dprintk("RPC:       xprt %p connected to %s\n",
1880                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1881                 xprt->stat.connect_count++;
1882                 xprt->stat.connect_time += (long)jiffies -
1883                                            xprt->stat.connect_start;
1884                 xprt_set_connected(xprt);
1885                 break;
1886         case -ENOBUFS:
1887                 break;
1888         case -ENOENT:
1889                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1890                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1891                 break;
1892         case -ECONNREFUSED:
1893                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1894                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1895                 break;
1896         default:
1897                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1898                                 __func__, -status,
1899                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1900         }
1901
1902 out:
1903         xprt_clear_connecting(xprt);
1904         xprt_wake_pending_tasks(xprt, status);
1905         return status;
1906 }
1907
1908 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1909 {
1910         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1911         int ret;
1912
1913          if (RPC_IS_ASYNC(task)) {
1914                 /*
1915                  * We want the AF_LOCAL connect to be resolved in the
1916                  * filesystem namespace of the process making the rpc
1917                  * call.  Thus we connect synchronously.
1918                  *
1919                  * If we want to support asynchronous AF_LOCAL calls,
1920                  * we'll need to figure out how to pass a namespace to
1921                  * connect.
1922                  */
1923                 task->tk_rpc_status = -ENOTCONN;
1924                 rpc_exit(task, -ENOTCONN);
1925                 return;
1926         }
1927         ret = xs_local_setup_socket(transport);
1928         if (ret && !RPC_IS_SOFTCONN(task))
1929                 msleep_interruptible(15000);
1930 }
1931
1932 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
1933 /*
1934  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
1935  * know that we have exclusive access to the socket), to guard against
1936  * races with xs_reset_transport.
1937  */
1938 static void xs_set_memalloc(struct rpc_xprt *xprt)
1939 {
1940         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1941                         xprt);
1942
1943         /*
1944          * If there's no sock, then we have nothing to set. The
1945          * reconnecting process will get it for us.
1946          */
1947         if (!transport->inet)
1948                 return;
1949         if (atomic_read(&xprt->swapper))
1950                 sk_set_memalloc(transport->inet);
1951 }
1952
1953 /**
1954  * xs_enable_swap - Tag this transport as being used for swap.
1955  * @xprt: transport to tag
1956  *
1957  * Take a reference to this transport on behalf of the rpc_clnt, and
1958  * optionally mark it for swapping if it wasn't already.
1959  */
1960 static int
1961 xs_enable_swap(struct rpc_xprt *xprt)
1962 {
1963         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1964
1965         if (atomic_inc_return(&xprt->swapper) != 1)
1966                 return 0;
1967         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1968                 return -ERESTARTSYS;
1969         if (xs->inet)
1970                 sk_set_memalloc(xs->inet);
1971         xprt_release_xprt(xprt, NULL);
1972         return 0;
1973 }
1974
1975 /**
1976  * xs_disable_swap - Untag this transport as being used for swap.
1977  * @xprt: transport to tag
1978  *
1979  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
1980  * swapper refcount goes to 0, untag the socket as a memalloc socket.
1981  */
1982 static void
1983 xs_disable_swap(struct rpc_xprt *xprt)
1984 {
1985         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
1986
1987         if (!atomic_dec_and_test(&xprt->swapper))
1988                 return;
1989         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
1990                 return;
1991         if (xs->inet)
1992                 sk_clear_memalloc(xs->inet);
1993         xprt_release_xprt(xprt, NULL);
1994 }
1995 #else
1996 static void xs_set_memalloc(struct rpc_xprt *xprt)
1997 {
1998 }
1999
2000 static int
2001 xs_enable_swap(struct rpc_xprt *xprt)
2002 {
2003         return -EINVAL;
2004 }
2005
2006 static void
2007 xs_disable_swap(struct rpc_xprt *xprt)
2008 {
2009 }
2010 #endif
2011
2012 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2013 {
2014         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2015
2016         if (!transport->inet) {
2017                 struct sock *sk = sock->sk;
2018
2019                 write_lock_bh(&sk->sk_callback_lock);
2020
2021                 xs_save_old_callbacks(transport, sk);
2022
2023                 sk->sk_user_data = xprt;
2024                 sk->sk_data_ready = xs_data_ready;
2025                 sk->sk_write_space = xs_udp_write_space;
2026                 sock_set_flag(sk, SOCK_FASYNC);
2027
2028                 xprt_set_connected(xprt);
2029
2030                 /* Reset to new socket */
2031                 transport->sock = sock;
2032                 transport->inet = sk;
2033
2034                 xs_set_memalloc(xprt);
2035
2036                 write_unlock_bh(&sk->sk_callback_lock);
2037         }
2038         xs_udp_do_set_buffer_size(xprt);
2039
2040         xprt->stat.connect_start = jiffies;
2041 }
2042
2043 static void xs_udp_setup_socket(struct work_struct *work)
2044 {
2045         struct sock_xprt *transport =
2046                 container_of(work, struct sock_xprt, connect_worker.work);
2047         struct rpc_xprt *xprt = &transport->xprt;
2048         struct socket *sock;
2049         int status = -EIO;
2050
2051         sock = xs_create_sock(xprt, transport,
2052                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2053                         IPPROTO_UDP, false);
2054         if (IS_ERR(sock))
2055                 goto out;
2056
2057         dprintk("RPC:       worker connecting xprt %p via %s to "
2058                                 "%s (port %s)\n", xprt,
2059                         xprt->address_strings[RPC_DISPLAY_PROTO],
2060                         xprt->address_strings[RPC_DISPLAY_ADDR],
2061                         xprt->address_strings[RPC_DISPLAY_PORT]);
2062
2063         xs_udp_finish_connecting(xprt, sock);
2064         trace_rpc_socket_connect(xprt, sock, 0);
2065         status = 0;
2066 out:
2067         xprt_clear_connecting(xprt);
2068         xprt_unlock_connect(xprt, transport);
2069         xprt_wake_pending_tasks(xprt, status);
2070 }
2071
2072 /**
2073  * xs_tcp_shutdown - gracefully shut down a TCP socket
2074  * @xprt: transport
2075  *
2076  * Initiates a graceful shutdown of the TCP socket by calling the
2077  * equivalent of shutdown(SHUT_RDWR);
2078  */
2079 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2080 {
2081         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2082         struct socket *sock = transport->sock;
2083         int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
2084
2085         if (sock == NULL)
2086                 return;
2087         switch (skst) {
2088         default:
2089                 kernel_sock_shutdown(sock, SHUT_RDWR);
2090                 trace_rpc_socket_shutdown(xprt, sock);
2091                 break;
2092         case TCP_CLOSE:
2093         case TCP_TIME_WAIT:
2094                 xs_reset_transport(transport);
2095         }
2096 }
2097
2098 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2099                 struct socket *sock)
2100 {
2101         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2102         unsigned int keepidle;
2103         unsigned int keepcnt;
2104         unsigned int timeo;
2105
2106         spin_lock(&xprt->transport_lock);
2107         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2108         keepcnt = xprt->timeout->to_retries + 1;
2109         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2110                 (xprt->timeout->to_retries + 1);
2111         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2112         spin_unlock(&xprt->transport_lock);
2113
2114         /* TCP Keepalive options */
2115         sock_set_keepalive(sock->sk);
2116         tcp_sock_set_keepidle(sock->sk, keepidle);
2117         tcp_sock_set_keepintvl(sock->sk, keepidle);
2118         tcp_sock_set_keepcnt(sock->sk, keepcnt);
2119
2120         /* TCP user timeout (see RFC5482) */
2121         tcp_sock_set_user_timeout(sock->sk, timeo);
2122 }
2123
2124 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2125                 unsigned long connect_timeout,
2126                 unsigned long reconnect_timeout)
2127 {
2128         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2129         struct rpc_timeout to;
2130         unsigned long initval;
2131
2132         spin_lock(&xprt->transport_lock);
2133         if (reconnect_timeout < xprt->max_reconnect_timeout)
2134                 xprt->max_reconnect_timeout = reconnect_timeout;
2135         if (connect_timeout < xprt->connect_timeout) {
2136                 memcpy(&to, xprt->timeout, sizeof(to));
2137                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2138                 /* Arbitrary lower limit */
2139                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2140                         initval = XS_TCP_INIT_REEST_TO << 1;
2141                 to.to_initval = initval;
2142                 to.to_maxval = initval;
2143                 memcpy(&transport->tcp_timeout, &to,
2144                                 sizeof(transport->tcp_timeout));
2145                 xprt->timeout = &transport->tcp_timeout;
2146                 xprt->connect_timeout = connect_timeout;
2147         }
2148         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2149         spin_unlock(&xprt->transport_lock);
2150 }
2151
2152 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2153 {
2154         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2155         int ret = -ENOTCONN;
2156
2157         if (!transport->inet) {
2158                 struct sock *sk = sock->sk;
2159
2160                 /* Avoid temporary address, they are bad for long-lived
2161                  * connections such as NFS mounts.
2162                  * RFC4941, section 3.6 suggests that:
2163                  *    Individual applications, which have specific
2164                  *    knowledge about the normal duration of connections,
2165                  *    MAY override this as appropriate.
2166                  */
2167                 if (xs_addr(xprt)->sa_family == PF_INET6) {
2168                         ip6_sock_set_addr_preferences(sk,
2169                                 IPV6_PREFER_SRC_PUBLIC);
2170                 }
2171
2172                 xs_tcp_set_socket_timeouts(xprt, sock);
2173                 tcp_sock_set_nodelay(sk);
2174
2175                 write_lock_bh(&sk->sk_callback_lock);
2176
2177                 xs_save_old_callbacks(transport, sk);
2178
2179                 sk->sk_user_data = xprt;
2180                 sk->sk_data_ready = xs_data_ready;
2181                 sk->sk_state_change = xs_tcp_state_change;
2182                 sk->sk_write_space = xs_tcp_write_space;
2183                 sock_set_flag(sk, SOCK_FASYNC);
2184                 sk->sk_error_report = xs_error_report;
2185
2186                 /* socket options */
2187                 sock_reset_flag(sk, SOCK_LINGER);
2188
2189                 xprt_clear_connected(xprt);
2190
2191                 /* Reset to new socket */
2192                 transport->sock = sock;
2193                 transport->inet = sk;
2194
2195                 write_unlock_bh(&sk->sk_callback_lock);
2196         }
2197
2198         if (!xprt_bound(xprt))
2199                 goto out;
2200
2201         xs_set_memalloc(xprt);
2202
2203         xs_stream_start_connect(transport);
2204
2205         /* Tell the socket layer to start connecting... */
2206         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2207         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2208         switch (ret) {
2209         case 0:
2210                 xs_set_srcport(transport, sock);
2211                 fallthrough;
2212         case -EINPROGRESS:
2213                 /* SYN_SENT! */
2214                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2215                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2216                 break;
2217         case -EADDRNOTAVAIL:
2218                 /* Source port number is unavailable. Try a new one! */
2219                 transport->srcport = 0;
2220         }
2221 out:
2222         return ret;
2223 }
2224
2225 /**
2226  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2227  * @work: queued work item
2228  *
2229  * Invoked by a work queue tasklet.
2230  */
2231 static void xs_tcp_setup_socket(struct work_struct *work)
2232 {
2233         struct sock_xprt *transport =
2234                 container_of(work, struct sock_xprt, connect_worker.work);
2235         struct socket *sock = transport->sock;
2236         struct rpc_xprt *xprt = &transport->xprt;
2237         int status = -EIO;
2238
2239         if (!sock) {
2240                 sock = xs_create_sock(xprt, transport,
2241                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2242                                 IPPROTO_TCP, true);
2243                 if (IS_ERR(sock)) {
2244                         status = PTR_ERR(sock);
2245                         goto out;
2246                 }
2247         }
2248
2249         dprintk("RPC:       worker connecting xprt %p via %s to "
2250                                 "%s (port %s)\n", xprt,
2251                         xprt->address_strings[RPC_DISPLAY_PROTO],
2252                         xprt->address_strings[RPC_DISPLAY_ADDR],
2253                         xprt->address_strings[RPC_DISPLAY_PORT]);
2254
2255         status = xs_tcp_finish_connecting(xprt, sock);
2256         trace_rpc_socket_connect(xprt, sock, status);
2257         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2258                         xprt, -status, xprt_connected(xprt),
2259                         sock->sk->sk_state);
2260         switch (status) {
2261         default:
2262                 printk("%s: connect returned unhandled error %d\n",
2263                         __func__, status);
2264                 fallthrough;
2265         case -EADDRNOTAVAIL:
2266                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2267                  * and retry
2268                  */
2269                 xs_tcp_force_close(xprt);
2270                 break;
2271         case 0:
2272         case -EINPROGRESS:
2273         case -EALREADY:
2274                 xprt_unlock_connect(xprt, transport);
2275                 return;
2276         case -EINVAL:
2277                 /* Happens, for instance, if the user specified a link
2278                  * local IPv6 address without a scope-id.
2279                  */
2280         case -ECONNREFUSED:
2281         case -ECONNRESET:
2282         case -ENETDOWN:
2283         case -ENETUNREACH:
2284         case -EHOSTUNREACH:
2285         case -EADDRINUSE:
2286         case -ENOBUFS:
2287                 /* xs_tcp_force_close() wakes tasks with a fixed error code.
2288                  * We need to wake them first to ensure the correct error code.
2289                  */
2290                 xprt_wake_pending_tasks(xprt, status);
2291                 xs_tcp_force_close(xprt);
2292                 goto out;
2293         }
2294         status = -EAGAIN;
2295 out:
2296         xprt_clear_connecting(xprt);
2297         xprt_unlock_connect(xprt, transport);
2298         xprt_wake_pending_tasks(xprt, status);
2299 }
2300
2301 /**
2302  * xs_connect - connect a socket to a remote endpoint
2303  * @xprt: pointer to transport structure
2304  * @task: address of RPC task that manages state of connect request
2305  *
2306  * TCP: If the remote end dropped the connection, delay reconnecting.
2307  *
2308  * UDP socket connects are synchronous, but we use a work queue anyway
2309  * to guarantee that even unprivileged user processes can set up a
2310  * socket on a privileged port.
2311  *
2312  * If a UDP socket connect fails, the delay behavior here prevents
2313  * retry floods (hard mounts).
2314  */
2315 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2316 {
2317         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2318         unsigned long delay = 0;
2319
2320         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2321
2322         if (transport->sock != NULL) {
2323                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2324                                 "seconds\n",
2325                                 xprt, xprt->reestablish_timeout / HZ);
2326
2327                 /* Start by resetting any existing state */
2328                 xs_reset_transport(transport);
2329
2330                 delay = xprt_reconnect_delay(xprt);
2331                 xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO);
2332
2333         } else
2334                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2335
2336         queue_delayed_work(xprtiod_workqueue,
2337                         &transport->connect_worker,
2338                         delay);
2339 }
2340
2341 static void xs_wake_disconnect(struct sock_xprt *transport)
2342 {
2343         if (test_and_clear_bit(XPRT_SOCK_WAKE_DISCONNECT, &transport->sock_state))
2344                 xs_tcp_force_close(&transport->xprt);
2345 }
2346
2347 static void xs_wake_write(struct sock_xprt *transport)
2348 {
2349         if (test_and_clear_bit(XPRT_SOCK_WAKE_WRITE, &transport->sock_state))
2350                 xprt_write_space(&transport->xprt);
2351 }
2352
2353 static void xs_wake_error(struct sock_xprt *transport)
2354 {
2355         int sockerr;
2356
2357         if (!test_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2358                 return;
2359         mutex_lock(&transport->recv_mutex);
2360         if (transport->sock == NULL)
2361                 goto out;
2362         if (!test_and_clear_bit(XPRT_SOCK_WAKE_ERROR, &transport->sock_state))
2363                 goto out;
2364         sockerr = xchg(&transport->xprt_err, 0);
2365         if (sockerr < 0)
2366                 xprt_wake_pending_tasks(&transport->xprt, sockerr);
2367 out:
2368         mutex_unlock(&transport->recv_mutex);
2369 }
2370
2371 static void xs_wake_pending(struct sock_xprt *transport)
2372 {
2373         if (test_and_clear_bit(XPRT_SOCK_WAKE_PENDING, &transport->sock_state))
2374                 xprt_wake_pending_tasks(&transport->xprt, -EAGAIN);
2375 }
2376
2377 static void xs_error_handle(struct work_struct *work)
2378 {
2379         struct sock_xprt *transport = container_of(work,
2380                         struct sock_xprt, error_worker);
2381
2382         xs_wake_disconnect(transport);
2383         xs_wake_write(transport);
2384         xs_wake_error(transport);
2385         xs_wake_pending(transport);
2386 }
2387
2388 /**
2389  * xs_local_print_stats - display AF_LOCAL socket-specific stats
2390  * @xprt: rpc_xprt struct containing statistics
2391  * @seq: output file
2392  *
2393  */
2394 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2395 {
2396         long idle_time = 0;
2397
2398         if (xprt_connected(xprt))
2399                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2400
2401         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2402                         "%llu %llu %lu %llu %llu\n",
2403                         xprt->stat.bind_count,
2404                         xprt->stat.connect_count,
2405                         xprt->stat.connect_time / HZ,
2406                         idle_time,
2407                         xprt->stat.sends,
2408                         xprt->stat.recvs,
2409                         xprt->stat.bad_xids,
2410                         xprt->stat.req_u,
2411                         xprt->stat.bklog_u,
2412                         xprt->stat.max_slots,
2413                         xprt->stat.sending_u,
2414                         xprt->stat.pending_u);
2415 }
2416
2417 /**
2418  * xs_udp_print_stats - display UDP socket-specific stats
2419  * @xprt: rpc_xprt struct containing statistics
2420  * @seq: output file
2421  *
2422  */
2423 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2424 {
2425         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2426
2427         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2428                         "%lu %llu %llu\n",
2429                         transport->srcport,
2430                         xprt->stat.bind_count,
2431                         xprt->stat.sends,
2432                         xprt->stat.recvs,
2433                         xprt->stat.bad_xids,
2434                         xprt->stat.req_u,
2435                         xprt->stat.bklog_u,
2436                         xprt->stat.max_slots,
2437                         xprt->stat.sending_u,
2438                         xprt->stat.pending_u);
2439 }
2440
2441 /**
2442  * xs_tcp_print_stats - display TCP socket-specific stats
2443  * @xprt: rpc_xprt struct containing statistics
2444  * @seq: output file
2445  *
2446  */
2447 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2448 {
2449         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2450         long idle_time = 0;
2451
2452         if (xprt_connected(xprt))
2453                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2454
2455         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2456                         "%llu %llu %lu %llu %llu\n",
2457                         transport->srcport,
2458                         xprt->stat.bind_count,
2459                         xprt->stat.connect_count,
2460                         xprt->stat.connect_time / HZ,
2461                         idle_time,
2462                         xprt->stat.sends,
2463                         xprt->stat.recvs,
2464                         xprt->stat.bad_xids,
2465                         xprt->stat.req_u,
2466                         xprt->stat.bklog_u,
2467                         xprt->stat.max_slots,
2468                         xprt->stat.sending_u,
2469                         xprt->stat.pending_u);
2470 }
2471
2472 /*
2473  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2474  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2475  * to use the server side send routines.
2476  */
2477 static int bc_malloc(struct rpc_task *task)
2478 {
2479         struct rpc_rqst *rqst = task->tk_rqstp;
2480         size_t size = rqst->rq_callsize;
2481         struct page *page;
2482         struct rpc_buffer *buf;
2483
2484         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2485                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2486                           size);
2487                 return -EINVAL;
2488         }
2489
2490         page = alloc_page(GFP_KERNEL);
2491         if (!page)
2492                 return -ENOMEM;
2493
2494         buf = page_address(page);
2495         buf->len = PAGE_SIZE;
2496
2497         rqst->rq_buffer = buf->data;
2498         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2499         return 0;
2500 }
2501
2502 /*
2503  * Free the space allocated in the bc_alloc routine
2504  */
2505 static void bc_free(struct rpc_task *task)
2506 {
2507         void *buffer = task->tk_rqstp->rq_buffer;
2508         struct rpc_buffer *buf;
2509
2510         buf = container_of(buffer, struct rpc_buffer, data);
2511         free_page((unsigned long)buf);
2512 }
2513
2514 static int bc_sendto(struct rpc_rqst *req)
2515 {
2516         struct xdr_buf *xdr = &req->rq_snd_buf;
2517         struct sock_xprt *transport =
2518                         container_of(req->rq_xprt, struct sock_xprt, xprt);
2519         struct msghdr msg = {
2520                 .msg_flags      = 0,
2521         };
2522         rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT |
2523                                          (u32)xdr->len);
2524         unsigned int sent = 0;
2525         int err;
2526
2527         req->rq_xtime = ktime_get();
2528         err = xprt_sock_sendmsg(transport->sock, &msg, xdr, 0, marker, &sent);
2529         xdr_free_bvec(xdr);
2530         if (err < 0 || sent != (xdr->len + sizeof(marker)))
2531                 return -EAGAIN;
2532         return sent;
2533 }
2534
2535 /**
2536  * bc_send_request - Send a backchannel Call on a TCP socket
2537  * @req: rpc_rqst containing Call message to be sent
2538  *
2539  * xpt_mutex ensures @rqstp's whole message is written to the socket
2540  * without interruption.
2541  *
2542  * Return values:
2543  *   %0 if the message was sent successfully
2544  *   %ENOTCONN if the message was not sent
2545  */
2546 static int bc_send_request(struct rpc_rqst *req)
2547 {
2548         struct svc_xprt *xprt;
2549         int len;
2550
2551         /*
2552          * Get the server socket associated with this callback xprt
2553          */
2554         xprt = req->rq_xprt->bc_xprt;
2555
2556         /*
2557          * Grab the mutex to serialize data as the connection is shared
2558          * with the fore channel
2559          */
2560         mutex_lock(&xprt->xpt_mutex);
2561         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2562                 len = -ENOTCONN;
2563         else
2564                 len = bc_sendto(req);
2565         mutex_unlock(&xprt->xpt_mutex);
2566
2567         if (len > 0)
2568                 len = 0;
2569
2570         return len;
2571 }
2572
2573 /*
2574  * The close routine. Since this is client initiated, we do nothing
2575  */
2576
2577 static void bc_close(struct rpc_xprt *xprt)
2578 {
2579         xprt_disconnect_done(xprt);
2580 }
2581
2582 /*
2583  * The xprt destroy routine. Again, because this connection is client
2584  * initiated, we do nothing
2585  */
2586
2587 static void bc_destroy(struct rpc_xprt *xprt)
2588 {
2589         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2590
2591         xs_xprt_free(xprt);
2592         module_put(THIS_MODULE);
2593 }
2594
2595 static const struct rpc_xprt_ops xs_local_ops = {
2596         .reserve_xprt           = xprt_reserve_xprt,
2597         .release_xprt           = xprt_release_xprt,
2598         .alloc_slot             = xprt_alloc_slot,
2599         .free_slot              = xprt_free_slot,
2600         .rpcbind                = xs_local_rpcbind,
2601         .set_port               = xs_local_set_port,
2602         .connect                = xs_local_connect,
2603         .buf_alloc              = rpc_malloc,
2604         .buf_free               = rpc_free,
2605         .prepare_request        = xs_stream_prepare_request,
2606         .send_request           = xs_local_send_request,
2607         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2608         .close                  = xs_close,
2609         .destroy                = xs_destroy,
2610         .print_stats            = xs_local_print_stats,
2611         .enable_swap            = xs_enable_swap,
2612         .disable_swap           = xs_disable_swap,
2613 };
2614
2615 static const struct rpc_xprt_ops xs_udp_ops = {
2616         .set_buffer_size        = xs_udp_set_buffer_size,
2617         .reserve_xprt           = xprt_reserve_xprt_cong,
2618         .release_xprt           = xprt_release_xprt_cong,
2619         .alloc_slot             = xprt_alloc_slot,
2620         .free_slot              = xprt_free_slot,
2621         .rpcbind                = rpcb_getport_async,
2622         .set_port               = xs_set_port,
2623         .connect                = xs_connect,
2624         .buf_alloc              = rpc_malloc,
2625         .buf_free               = rpc_free,
2626         .send_request           = xs_udp_send_request,
2627         .wait_for_reply_request = xprt_wait_for_reply_request_rtt,
2628         .timer                  = xs_udp_timer,
2629         .release_request        = xprt_release_rqst_cong,
2630         .close                  = xs_close,
2631         .destroy                = xs_destroy,
2632         .print_stats            = xs_udp_print_stats,
2633         .enable_swap            = xs_enable_swap,
2634         .disable_swap           = xs_disable_swap,
2635         .inject_disconnect      = xs_inject_disconnect,
2636 };
2637
2638 static const struct rpc_xprt_ops xs_tcp_ops = {
2639         .reserve_xprt           = xprt_reserve_xprt,
2640         .release_xprt           = xprt_release_xprt,
2641         .alloc_slot             = xprt_alloc_slot,
2642         .free_slot              = xprt_free_slot,
2643         .rpcbind                = rpcb_getport_async,
2644         .set_port               = xs_set_port,
2645         .connect                = xs_connect,
2646         .buf_alloc              = rpc_malloc,
2647         .buf_free               = rpc_free,
2648         .prepare_request        = xs_stream_prepare_request,
2649         .send_request           = xs_tcp_send_request,
2650         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2651         .close                  = xs_tcp_shutdown,
2652         .destroy                = xs_destroy,
2653         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2654         .print_stats            = xs_tcp_print_stats,
2655         .enable_swap            = xs_enable_swap,
2656         .disable_swap           = xs_disable_swap,
2657         .inject_disconnect      = xs_inject_disconnect,
2658 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2659         .bc_setup               = xprt_setup_bc,
2660         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2661         .bc_num_slots           = xprt_bc_max_slots,
2662         .bc_free_rqst           = xprt_free_bc_rqst,
2663         .bc_destroy             = xprt_destroy_bc,
2664 #endif
2665 };
2666
2667 /*
2668  * The rpc_xprt_ops for the server backchannel
2669  */
2670
2671 static const struct rpc_xprt_ops bc_tcp_ops = {
2672         .reserve_xprt           = xprt_reserve_xprt,
2673         .release_xprt           = xprt_release_xprt,
2674         .alloc_slot             = xprt_alloc_slot,
2675         .free_slot              = xprt_free_slot,
2676         .buf_alloc              = bc_malloc,
2677         .buf_free               = bc_free,
2678         .send_request           = bc_send_request,
2679         .wait_for_reply_request = xprt_wait_for_reply_request_def,
2680         .close                  = bc_close,
2681         .destroy                = bc_destroy,
2682         .print_stats            = xs_tcp_print_stats,
2683         .enable_swap            = xs_enable_swap,
2684         .disable_swap           = xs_disable_swap,
2685         .inject_disconnect      = xs_inject_disconnect,
2686 };
2687
2688 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2689 {
2690         static const struct sockaddr_in sin = {
2691                 .sin_family             = AF_INET,
2692                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2693         };
2694         static const struct sockaddr_in6 sin6 = {
2695                 .sin6_family            = AF_INET6,
2696                 .sin6_addr              = IN6ADDR_ANY_INIT,
2697         };
2698
2699         switch (family) {
2700         case AF_LOCAL:
2701                 break;
2702         case AF_INET:
2703                 memcpy(sap, &sin, sizeof(sin));
2704                 break;
2705         case AF_INET6:
2706                 memcpy(sap, &sin6, sizeof(sin6));
2707                 break;
2708         default:
2709                 dprintk("RPC:       %s: Bad address family\n", __func__);
2710                 return -EAFNOSUPPORT;
2711         }
2712         return 0;
2713 }
2714
2715 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2716                                       unsigned int slot_table_size,
2717                                       unsigned int max_slot_table_size)
2718 {
2719         struct rpc_xprt *xprt;
2720         struct sock_xprt *new;
2721
2722         if (args->addrlen > sizeof(xprt->addr)) {
2723                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2724                 return ERR_PTR(-EBADF);
2725         }
2726
2727         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2728                         max_slot_table_size);
2729         if (xprt == NULL) {
2730                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2731                                 "rpc_xprt\n");
2732                 return ERR_PTR(-ENOMEM);
2733         }
2734
2735         new = container_of(xprt, struct sock_xprt, xprt);
2736         mutex_init(&new->recv_mutex);
2737         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2738         xprt->addrlen = args->addrlen;
2739         if (args->srcaddr)
2740                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2741         else {
2742                 int err;
2743                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2744                                         (struct sockaddr *)&new->srcaddr);
2745                 if (err != 0) {
2746                         xprt_free(xprt);
2747                         return ERR_PTR(err);
2748                 }
2749         }
2750
2751         return xprt;
2752 }
2753
2754 static const struct rpc_timeout xs_local_default_timeout = {
2755         .to_initval = 10 * HZ,
2756         .to_maxval = 10 * HZ,
2757         .to_retries = 2,
2758 };
2759
2760 /**
2761  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2762  * @args: rpc transport creation arguments
2763  *
2764  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2765  */
2766 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2767 {
2768         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2769         struct sock_xprt *transport;
2770         struct rpc_xprt *xprt;
2771         struct rpc_xprt *ret;
2772
2773         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2774                         xprt_max_tcp_slot_table_entries);
2775         if (IS_ERR(xprt))
2776                 return xprt;
2777         transport = container_of(xprt, struct sock_xprt, xprt);
2778
2779         xprt->prot = 0;
2780         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2781
2782         xprt->bind_timeout = XS_BIND_TO;
2783         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2784         xprt->idle_timeout = XS_IDLE_DISC_TO;
2785
2786         xprt->ops = &xs_local_ops;
2787         xprt->timeout = &xs_local_default_timeout;
2788
2789         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2790         INIT_WORK(&transport->error_worker, xs_error_handle);
2791         INIT_DELAYED_WORK(&transport->connect_worker, xs_dummy_setup_socket);
2792
2793         switch (sun->sun_family) {
2794         case AF_LOCAL:
2795                 if (sun->sun_path[0] != '/') {
2796                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2797                                         sun->sun_path);
2798                         ret = ERR_PTR(-EINVAL);
2799                         goto out_err;
2800                 }
2801                 xprt_set_bound(xprt);
2802                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2803                 ret = ERR_PTR(xs_local_setup_socket(transport));
2804                 if (ret)
2805                         goto out_err;
2806                 break;
2807         default:
2808                 ret = ERR_PTR(-EAFNOSUPPORT);
2809                 goto out_err;
2810         }
2811
2812         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2813                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2814
2815         if (try_module_get(THIS_MODULE))
2816                 return xprt;
2817         ret = ERR_PTR(-EINVAL);
2818 out_err:
2819         xs_xprt_free(xprt);
2820         return ret;
2821 }
2822
2823 static const struct rpc_timeout xs_udp_default_timeout = {
2824         .to_initval = 5 * HZ,
2825         .to_maxval = 30 * HZ,
2826         .to_increment = 5 * HZ,
2827         .to_retries = 5,
2828 };
2829
2830 /**
2831  * xs_setup_udp - Set up transport to use a UDP socket
2832  * @args: rpc transport creation arguments
2833  *
2834  */
2835 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2836 {
2837         struct sockaddr *addr = args->dstaddr;
2838         struct rpc_xprt *xprt;
2839         struct sock_xprt *transport;
2840         struct rpc_xprt *ret;
2841
2842         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2843                         xprt_udp_slot_table_entries);
2844         if (IS_ERR(xprt))
2845                 return xprt;
2846         transport = container_of(xprt, struct sock_xprt, xprt);
2847
2848         xprt->prot = IPPROTO_UDP;
2849         /* XXX: header size can vary due to auth type, IPv6, etc. */
2850         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2851
2852         xprt->bind_timeout = XS_BIND_TO;
2853         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2854         xprt->idle_timeout = XS_IDLE_DISC_TO;
2855
2856         xprt->ops = &xs_udp_ops;
2857
2858         xprt->timeout = &xs_udp_default_timeout;
2859
2860         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2861         INIT_WORK(&transport->error_worker, xs_error_handle);
2862         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2863
2864         switch (addr->sa_family) {
2865         case AF_INET:
2866                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2867                         xprt_set_bound(xprt);
2868
2869                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2870                 break;
2871         case AF_INET6:
2872                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2873                         xprt_set_bound(xprt);
2874
2875                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2876                 break;
2877         default:
2878                 ret = ERR_PTR(-EAFNOSUPPORT);
2879                 goto out_err;
2880         }
2881
2882         if (xprt_bound(xprt))
2883                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2884                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2885                                 xprt->address_strings[RPC_DISPLAY_PORT],
2886                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2887         else
2888                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2889                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2890                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2891
2892         if (try_module_get(THIS_MODULE))
2893                 return xprt;
2894         ret = ERR_PTR(-EINVAL);
2895 out_err:
2896         xs_xprt_free(xprt);
2897         return ret;
2898 }
2899
2900 static const struct rpc_timeout xs_tcp_default_timeout = {
2901         .to_initval = 60 * HZ,
2902         .to_maxval = 60 * HZ,
2903         .to_retries = 2,
2904 };
2905
2906 /**
2907  * xs_setup_tcp - Set up transport to use a TCP socket
2908  * @args: rpc transport creation arguments
2909  *
2910  */
2911 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2912 {
2913         struct sockaddr *addr = args->dstaddr;
2914         struct rpc_xprt *xprt;
2915         struct sock_xprt *transport;
2916         struct rpc_xprt *ret;
2917         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2918
2919         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2920                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2921
2922         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2923                         max_slot_table_size);
2924         if (IS_ERR(xprt))
2925                 return xprt;
2926         transport = container_of(xprt, struct sock_xprt, xprt);
2927
2928         xprt->prot = IPPROTO_TCP;
2929         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2930
2931         xprt->bind_timeout = XS_BIND_TO;
2932         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2933         xprt->idle_timeout = XS_IDLE_DISC_TO;
2934
2935         xprt->ops = &xs_tcp_ops;
2936         xprt->timeout = &xs_tcp_default_timeout;
2937
2938         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
2939         xprt->connect_timeout = xprt->timeout->to_initval *
2940                 (xprt->timeout->to_retries + 1);
2941
2942         INIT_WORK(&transport->recv_worker, xs_stream_data_receive_workfn);
2943         INIT_WORK(&transport->error_worker, xs_error_handle);
2944         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2945
2946         switch (addr->sa_family) {
2947         case AF_INET:
2948                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2949                         xprt_set_bound(xprt);
2950
2951                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2952                 break;
2953         case AF_INET6:
2954                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2955                         xprt_set_bound(xprt);
2956
2957                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2958                 break;
2959         default:
2960                 ret = ERR_PTR(-EAFNOSUPPORT);
2961                 goto out_err;
2962         }
2963
2964         if (xprt_bound(xprt))
2965                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2966                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2967                                 xprt->address_strings[RPC_DISPLAY_PORT],
2968                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2969         else
2970                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2971                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2972                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2973
2974         if (try_module_get(THIS_MODULE))
2975                 return xprt;
2976         ret = ERR_PTR(-EINVAL);
2977 out_err:
2978         xs_xprt_free(xprt);
2979         return ret;
2980 }
2981
2982 /**
2983  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2984  * @args: rpc transport creation arguments
2985  *
2986  */
2987 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2988 {
2989         struct sockaddr *addr = args->dstaddr;
2990         struct rpc_xprt *xprt;
2991         struct sock_xprt *transport;
2992         struct svc_sock *bc_sock;
2993         struct rpc_xprt *ret;
2994
2995         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2996                         xprt_tcp_slot_table_entries);
2997         if (IS_ERR(xprt))
2998                 return xprt;
2999         transport = container_of(xprt, struct sock_xprt, xprt);
3000
3001         xprt->prot = IPPROTO_TCP;
3002         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3003         xprt->timeout = &xs_tcp_default_timeout;
3004
3005         /* backchannel */
3006         xprt_set_bound(xprt);
3007         xprt->bind_timeout = 0;
3008         xprt->reestablish_timeout = 0;
3009         xprt->idle_timeout = 0;
3010
3011         xprt->ops = &bc_tcp_ops;
3012
3013         switch (addr->sa_family) {
3014         case AF_INET:
3015                 xs_format_peer_addresses(xprt, "tcp",
3016                                          RPCBIND_NETID_TCP);
3017                 break;
3018         case AF_INET6:
3019                 xs_format_peer_addresses(xprt, "tcp",
3020                                    RPCBIND_NETID_TCP6);
3021                 break;
3022         default:
3023                 ret = ERR_PTR(-EAFNOSUPPORT);
3024                 goto out_err;
3025         }
3026
3027         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3028                         xprt->address_strings[RPC_DISPLAY_ADDR],
3029                         xprt->address_strings[RPC_DISPLAY_PORT],
3030                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3031
3032         /*
3033          * Once we've associated a backchannel xprt with a connection,
3034          * we want to keep it around as long as the connection lasts,
3035          * in case we need to start using it for a backchannel again;
3036          * this reference won't be dropped until bc_xprt is destroyed.
3037          */
3038         xprt_get(xprt);
3039         args->bc_xprt->xpt_bc_xprt = xprt;
3040         xprt->bc_xprt = args->bc_xprt;
3041         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3042         transport->sock = bc_sock->sk_sock;
3043         transport->inet = bc_sock->sk_sk;
3044
3045         /*
3046          * Since we don't want connections for the backchannel, we set
3047          * the xprt status to connected
3048          */
3049         xprt_set_connected(xprt);
3050
3051         if (try_module_get(THIS_MODULE))
3052                 return xprt;
3053
3054         args->bc_xprt->xpt_bc_xprt = NULL;
3055         args->bc_xprt->xpt_bc_xps = NULL;
3056         xprt_put(xprt);
3057         ret = ERR_PTR(-EINVAL);
3058 out_err:
3059         xs_xprt_free(xprt);
3060         return ret;
3061 }
3062
3063 static struct xprt_class        xs_local_transport = {
3064         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3065         .name           = "named UNIX socket",
3066         .owner          = THIS_MODULE,
3067         .ident          = XPRT_TRANSPORT_LOCAL,
3068         .setup          = xs_setup_local,
3069         .netid          = { "" },
3070 };
3071
3072 static struct xprt_class        xs_udp_transport = {
3073         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3074         .name           = "udp",
3075         .owner          = THIS_MODULE,
3076         .ident          = XPRT_TRANSPORT_UDP,
3077         .setup          = xs_setup_udp,
3078         .netid          = { "udp", "udp6", "" },
3079 };
3080
3081 static struct xprt_class        xs_tcp_transport = {
3082         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3083         .name           = "tcp",
3084         .owner          = THIS_MODULE,
3085         .ident          = XPRT_TRANSPORT_TCP,
3086         .setup          = xs_setup_tcp,
3087         .netid          = { "tcp", "tcp6", "" },
3088 };
3089
3090 static struct xprt_class        xs_bc_tcp_transport = {
3091         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3092         .name           = "tcp NFSv4.1 backchannel",
3093         .owner          = THIS_MODULE,
3094         .ident          = XPRT_TRANSPORT_BC_TCP,
3095         .setup          = xs_setup_bc_tcp,
3096         .netid          = { "" },
3097 };
3098
3099 /**
3100  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3101  *
3102  */
3103 int init_socket_xprt(void)
3104 {
3105         if (!sunrpc_table_header)
3106                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3107
3108         xprt_register_transport(&xs_local_transport);
3109         xprt_register_transport(&xs_udp_transport);
3110         xprt_register_transport(&xs_tcp_transport);
3111         xprt_register_transport(&xs_bc_tcp_transport);
3112
3113         return 0;
3114 }
3115
3116 /**
3117  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3118  *
3119  */
3120 void cleanup_socket_xprt(void)
3121 {
3122         if (sunrpc_table_header) {
3123                 unregister_sysctl_table(sunrpc_table_header);
3124                 sunrpc_table_header = NULL;
3125         }
3126
3127         xprt_unregister_transport(&xs_local_transport);
3128         xprt_unregister_transport(&xs_udp_transport);
3129         xprt_unregister_transport(&xs_tcp_transport);
3130         xprt_unregister_transport(&xs_bc_tcp_transport);
3131 }
3132
3133 static int param_set_uint_minmax(const char *val,
3134                 const struct kernel_param *kp,
3135                 unsigned int min, unsigned int max)
3136 {
3137         unsigned int num;
3138         int ret;
3139
3140         if (!val)
3141                 return -EINVAL;
3142         ret = kstrtouint(val, 0, &num);
3143         if (ret)
3144                 return ret;
3145         if (num < min || num > max)
3146                 return -EINVAL;
3147         *((unsigned int *)kp->arg) = num;
3148         return 0;
3149 }
3150
3151 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3152 {
3153         return param_set_uint_minmax(val, kp,
3154                         RPC_MIN_RESVPORT,
3155                         RPC_MAX_RESVPORT);
3156 }
3157
3158 static const struct kernel_param_ops param_ops_portnr = {
3159         .set = param_set_portnr,
3160         .get = param_get_uint,
3161 };
3162
3163 #define param_check_portnr(name, p) \
3164         __param_check(name, p, unsigned int);
3165
3166 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3167 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3168
3169 static int param_set_slot_table_size(const char *val,
3170                                      const struct kernel_param *kp)
3171 {
3172         return param_set_uint_minmax(val, kp,
3173                         RPC_MIN_SLOT_TABLE,
3174                         RPC_MAX_SLOT_TABLE);
3175 }
3176
3177 static const struct kernel_param_ops param_ops_slot_table_size = {
3178         .set = param_set_slot_table_size,
3179         .get = param_get_uint,
3180 };
3181
3182 #define param_check_slot_table_size(name, p) \
3183         __param_check(name, p, unsigned int);
3184
3185 static int param_set_max_slot_table_size(const char *val,
3186                                      const struct kernel_param *kp)
3187 {
3188         return param_set_uint_minmax(val, kp,
3189                         RPC_MIN_SLOT_TABLE,
3190                         RPC_MAX_SLOT_TABLE_LIMIT);
3191 }
3192
3193 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3194         .set = param_set_max_slot_table_size,
3195         .get = param_get_uint,
3196 };
3197
3198 #define param_check_max_slot_table_size(name, p) \
3199         __param_check(name, p, unsigned int);
3200
3201 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3202                    slot_table_size, 0644);
3203 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3204                    max_slot_table_size, 0644);
3205 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3206                    slot_table_size, 0644);