net/sunrpc/xprtsock.c

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