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 #define XS_TCP_LINGER_TO        (15U * HZ)
  67 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  68
  69 /*
  70  * We can register our own files under /proc/sys/sunrpc by
  71  * calling register_sysctl_table() again.  The files in that
  72  * directory become the union of all files registered there.
  73  *
  74  * We simply need to make sure that we don't collide with
  75  * someone else's file names!
  76  */
  77
  78 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  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         if (likely(sent > 0) || status == 0) {
 531                 req->rq_bytes_sent += sent;
 532                 req->rq_xmit_bytes_sent += sent;
 533                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 534                         req->rq_bytes_sent = 0;
 535                         return 0;
 536                 }
 537                 status = -EAGAIN;
 538         }
 539
 540         switch (status) {
 541         case -ENOBUFS:
 542         case -EAGAIN:
 543                 status = xs_nospace(task);
 544                 break;
 545         default:
 546                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 547                         -status);
 548         case -EPIPE:
 549                 xs_close(xprt);
 550                 status = -ENOTCONN;
 551         }
 552
 553         return status;
 554 }
 555
 556 /**
 557  * xs_udp_send_request - write an RPC request to a UDP socket
 558  * @task: address of RPC task that manages the state of an RPC request
 559  *
 560  * Return values:
 561  *        0:    The request has been sent
 562  *   EAGAIN:    The socket was blocked, please call again later to
 563  *              complete the request
 564  * ENOTCONN:    Caller needs to invoke connect logic then call again
 565  *    other:    Some other error occurred, the request was not sent
 566  */
 567 static int xs_udp_send_request(struct rpc_task *task)
 568 {
 569         struct rpc_rqst *req = task->tk_rqstp;
 570         struct rpc_xprt *xprt = req->rq_xprt;
 571         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 572         struct xdr_buf *xdr = &req->rq_snd_buf;
 573         int sent = 0;
 574         int status;
 575
 576         xs_pktdump("packet data:",
 577                                 req->rq_svec->iov_base,
 578                                 req->rq_svec->iov_len);
 579
 580         if (!xprt_bound(xprt))
 581                 return -ENOTCONN;
 582         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
 583                               xdr, req->rq_bytes_sent, true, &sent);
 584
 585         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 586                         xdr->len - req->rq_bytes_sent, status);
 587
 588         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
 589         if (status == -EPERM)
 590                 goto process_status;
 591
 592         if (sent > 0 || status == 0) {
 593                 req->rq_xmit_bytes_sent += sent;
 594                 if (sent >= req->rq_slen)
 595                         return 0;
 596                 /* Still some bytes left; set up for a retry later. */
 597                 status = -EAGAIN;
 598         }
 599
 600 process_status:
 601         switch (status) {
 602         case -ENOTSOCK:
 603                 status = -ENOTCONN;
 604                 /* Should we call xs_close() here? */
 605                 break;
 606         case -EAGAIN:
 607                 status = xs_nospace(task);
 608                 break;
 609         default:
 610                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 611                         -status);
 612         case -ENETUNREACH:
 613         case -ENOBUFS:
 614         case -EPIPE:
 615         case -ECONNREFUSED:
 616         case -EPERM:
 617                 /* When the server has died, an ICMP port unreachable message
 618                  * prompts ECONNREFUSED. */
 619                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 620         }
 621
 622         return status;
 623 }
 624
 625 /**
 626  * xs_tcp_shutdown - gracefully shut down a TCP socket
 627  * @xprt: transport
 628  *
 629  * Initiates a graceful shutdown of the TCP socket by calling the
 630  * equivalent of shutdown(SHUT_WR);
 631  */
 632 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 633 {
 634         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 635         struct socket *sock = transport->sock;
 636
 637         if (sock != NULL) {
 638                 kernel_sock_shutdown(sock, SHUT_WR);
 639                 trace_rpc_socket_shutdown(xprt, sock);
 640         }
 641 }
 642
 643 /**
 644  * xs_tcp_send_request - write an RPC request to a TCP socket
 645  * @task: address of RPC task that manages the state of an RPC request
 646  *
 647  * Return values:
 648  *        0:    The request has been sent
 649  *   EAGAIN:    The socket was blocked, please call again later to
 650  *              complete the request
 651  * ENOTCONN:    Caller needs to invoke connect logic then call again
 652  *    other:    Some other error occurred, the request was not sent
 653  *
 654  * XXX: In the case of soft timeouts, should we eventually give up
 655  *      if sendmsg is not able to make progress?
 656  */
 657 static int xs_tcp_send_request(struct rpc_task *task)
 658 {
 659         struct rpc_rqst *req = task->tk_rqstp;
 660         struct rpc_xprt *xprt = req->rq_xprt;
 661         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 662         struct xdr_buf *xdr = &req->rq_snd_buf;
 663         bool zerocopy = true;
 664         int status;
 665         int sent;
 666
 667         xs_encode_stream_record_marker(&req->rq_snd_buf);
 668
 669         xs_pktdump("packet data:",
 670                                 req->rq_svec->iov_base,
 671                                 req->rq_svec->iov_len);
 672         /* Don't use zero copy if this is a resend. If the RPC call
 673          * completes while the socket holds a reference to the pages,
 674          * then we may end up resending corrupted data.
 675          */
 676         if (task->tk_flags & RPC_TASK_SENT)
 677                 zerocopy = false;
 678
 679         /* Continue transmitting the packet/record. We must be careful
 680          * to cope with writespace callbacks arriving _after_ we have
 681          * called sendmsg(). */
 682         while (1) {
 683                 sent = 0;
 684                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
 685                                       req->rq_bytes_sent, zerocopy, &sent);
 686
 687                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 688                                 xdr->len - req->rq_bytes_sent, status);
 689
 690                 if (unlikely(sent == 0 && status < 0))
 691                         break;
 692
 693                 /* If we've sent the entire packet, immediately
 694                  * reset the count of bytes sent. */
 695                 req->rq_bytes_sent += sent;
 696                 req->rq_xmit_bytes_sent += sent;
 697                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 698                         req->rq_bytes_sent = 0;
 699                         return 0;
 700                 }
 701
 702                 if (sent != 0)
 703                         continue;
 704                 status = -EAGAIN;
 705                 break;
 706         }
 707
 708         switch (status) {
 709         case -ENOTSOCK:
 710                 status = -ENOTCONN;
 711                 /* Should we call xs_close() here? */
 712                 break;
 713         case -ENOBUFS:
 714         case -EAGAIN:
 715                 status = xs_nospace(task);
 716                 break;
 717         default:
 718                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 719                         -status);
 720         case -ECONNRESET:
 721                 xs_tcp_shutdown(xprt);
 722         case -ECONNREFUSED:
 723         case -ENOTCONN:
 724         case -EADDRINUSE:
 725         case -EPIPE:
 726                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 727         }
 728
 729         return status;
 730 }
 731
 732 /**
 733  * xs_tcp_release_xprt - clean up after a tcp transmission
 734  * @xprt: transport
 735  * @task: rpc task
 736  *
 737  * This cleans up if an error causes us to abort the transmission of a request.
 738  * In this case, the socket may need to be reset in order to avoid confusing
 739  * the server.
 740  */
 741 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 742 {
 743         struct rpc_rqst *req;
 744
 745         if (task != xprt->snd_task)
 746                 return;
 747         if (task == NULL)
 748                 goto out_release;
 749         req = task->tk_rqstp;
 750         if (req == NULL)
 751                 goto out_release;
 752         if (req->rq_bytes_sent == 0)
 753                 goto out_release;
 754         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 755                 goto out_release;
 756         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 757 out_release:
 758         xprt_release_xprt(xprt, task);
 759 }
 760
 761 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 762 {
 763         transport->old_data_ready = sk->sk_data_ready;
 764         transport->old_state_change = sk->sk_state_change;
 765         transport->old_write_space = sk->sk_write_space;
 766         transport->old_error_report = sk->sk_error_report;
 767 }
 768
 769 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 770 {
 771         sk->sk_data_ready = transport->old_data_ready;
 772         sk->sk_state_change = transport->old_state_change;
 773         sk->sk_write_space = transport->old_write_space;
 774         sk->sk_error_report = transport->old_error_report;
 775 }
 776
 777 /**
 778  * xs_error_report - callback to handle TCP socket state errors
 779  * @sk: socket
 780  *
 781  * Note: we don't call sock_error() since there may be a rpc_task
 782  * using the socket, and so we don't want to clear sk->sk_err.
 783  */
 784 static void xs_error_report(struct sock *sk)
 785 {
 786         struct rpc_xprt *xprt;
 787         int err;
 788
 789         read_lock_bh(&sk->sk_callback_lock);
 790         if (!(xprt = xprt_from_sock(sk)))
 791                 goto out;
 792
 793         err = -sk->sk_err;
 794         if (err == 0)
 795                 goto out;
 796         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 797                         xprt, -err);
 798         trace_rpc_socket_error(xprt, sk->sk_socket, err);
 799         if (test_bit(XPRT_CONNECTION_REUSE, &xprt->state))
 800                 goto out;
 801         xprt_wake_pending_tasks(xprt, err);
 802  out:
 803         read_unlock_bh(&sk->sk_callback_lock);
 804 }
 805
 806 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
 807 {
 808         smp_mb__before_atomic();
 809         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
 810         clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
 811         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 812         clear_bit(XPRT_CLOSING, &xprt->state);
 813         smp_mb__after_atomic();
 814 }
 815
 816 static void xs_reset_transport(struct sock_xprt *transport)
 817 {
 818         struct socket *sock = transport->sock;
 819         struct sock *sk = transport->inet;
 820         struct rpc_xprt *xprt = &transport->xprt;
 821
 822         if (sk == NULL)
 823                 return;
 824
 825         write_lock_bh(&sk->sk_callback_lock);
 826         transport->inet = NULL;
 827         transport->sock = NULL;
 828
 829         sk->sk_user_data = NULL;
 830
 831         xs_restore_old_callbacks(transport, sk);
 832         write_unlock_bh(&sk->sk_callback_lock);
 833         xs_sock_reset_connection_flags(xprt);
 834
 835         trace_rpc_socket_close(xprt, sock);
 836         sock_release(sock);
 837 }
 838
 839 /**
 840  * xs_close - close a socket
 841  * @xprt: transport
 842  *
 843  * This is used when all requests are complete; ie, no DRC state remains
 844  * on the server we want to save.
 845  *
 846  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 847  * xs_reset_transport() zeroing the socket from underneath a writer.
 848  */
 849 static void xs_close(struct rpc_xprt *xprt)
 850 {
 851         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 852
 853         dprintk("RPC:       xs_close xprt %p\n", xprt);
 854
 855         cancel_delayed_work_sync(&transport->connect_worker);
 856
 857         xs_reset_transport(transport);
 858         xprt->reestablish_timeout = 0;
 859
 860         xprt_disconnect_done(xprt);
 861 }
 862
 863 static void xs_tcp_close(struct rpc_xprt *xprt)
 864 {
 865         if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
 866                 xs_close(xprt);
 867         else
 868                 xs_tcp_shutdown(xprt);
 869 }
 870
 871 static void xs_xprt_free(struct rpc_xprt *xprt)
 872 {
 873         xs_free_peer_addresses(xprt);
 874         xprt_free(xprt);
 875 }
 876
 877 /**
 878  * xs_destroy - prepare to shutdown a transport
 879  * @xprt: doomed transport
 880  *
 881  */
 882 static void xs_destroy(struct rpc_xprt *xprt)
 883 {
 884         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 885
 886         xs_close(xprt);
 887         xs_xprt_free(xprt);
 888         module_put(THIS_MODULE);
 889 }
 890
 891 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 892 {
 893         struct xdr_skb_reader desc = {
 894                 .skb            = skb,
 895                 .offset         = sizeof(rpc_fraghdr),
 896                 .count          = skb->len - sizeof(rpc_fraghdr),
 897         };
 898
 899         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
 900                 return -1;
 901         if (desc.count)
 902                 return -1;
 903         return 0;
 904 }
 905
 906 /**
 907  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
 908  * @sk: socket with data to read
 909  * @len: how much data to read
 910  *
 911  * Currently this assumes we can read the whole reply in a single gulp.
 912  */
 913 static void xs_local_data_ready(struct sock *sk)
 914 {
 915         struct rpc_task *task;
 916         struct rpc_xprt *xprt;
 917         struct rpc_rqst *rovr;
 918         struct sk_buff *skb;
 919         int err, repsize, copied;
 920         u32 _xid;
 921         __be32 *xp;
 922
 923         read_lock_bh(&sk->sk_callback_lock);
 924         dprintk("RPC:       %s...\n", __func__);
 925         xprt = xprt_from_sock(sk);
 926         if (xprt == NULL)
 927                 goto out;
 928
 929         skb = skb_recv_datagram(sk, 0, 1, &err);
 930         if (skb == NULL)
 931                 goto out;
 932
 933         repsize = skb->len - sizeof(rpc_fraghdr);
 934         if (repsize < 4) {
 935                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
 936                 goto dropit;
 937         }
 938
 939         /* Copy the XID from the skb... */
 940         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 941         if (xp == NULL)
 942                 goto dropit;
 943
 944         /* Look up and lock the request corresponding to the given XID */
 945         spin_lock(&xprt->transport_lock);
 946         rovr = xprt_lookup_rqst(xprt, *xp);
 947         if (!rovr)
 948                 goto out_unlock;
 949         task = rovr->rq_task;
 950
 951         copied = rovr->rq_private_buf.buflen;
 952         if (copied > repsize)
 953                 copied = repsize;
 954
 955         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 956                 dprintk("RPC:       sk_buff copy failed\n");
 957                 goto out_unlock;
 958         }
 959
 960         xprt_complete_rqst(task, copied);
 961
 962  out_unlock:
 963         spin_unlock(&xprt->transport_lock);
 964  dropit:
 965         skb_free_datagram(sk, skb);
 966  out:
 967         read_unlock_bh(&sk->sk_callback_lock);
 968 }
 969
 970 /**
 971  * xs_udp_data_ready - "data ready" callback for UDP sockets
 972  * @sk: socket with data to read
 973  * @len: how much 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         set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1042         xprt_force_disconnect(xprt);
1043 }
1044
1045 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1046 {
1047         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1048         size_t len, used;
1049         char *p;
1050
1051         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1052         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1053         used = xdr_skb_read_bits(desc, p, len);
1054         transport->tcp_offset += used;
1055         if (used != len)
1056                 return;
1057
1058         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1059         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1060                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1061         else
1062                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1063         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1064
1065         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1066         transport->tcp_offset = 0;
1067
1068         /* Sanity check of the record length */
1069         if (unlikely(transport->tcp_reclen < 8)) {
1070                 dprintk("RPC:       invalid TCP record fragment length\n");
1071                 xs_tcp_force_close(xprt);
1072                 return;
1073         }
1074         dprintk("RPC:       reading TCP record fragment of length %d\n",
1075                         transport->tcp_reclen);
1076 }
1077
1078 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1079 {
1080         if (transport->tcp_offset == transport->tcp_reclen) {
1081                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1082                 transport->tcp_offset = 0;
1083                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1084                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1085                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1086                         transport->tcp_copied = 0;
1087                 }
1088         }
1089 }
1090
1091 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1092 {
1093         size_t len, used;
1094         char *p;
1095
1096         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1097         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1098         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1099         used = xdr_skb_read_bits(desc, p, len);
1100         transport->tcp_offset += used;
1101         if (used != len)
1102                 return;
1103         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1104         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1105         transport->tcp_copied = 4;
1106         dprintk("RPC:       reading %s XID %08x\n",
1107                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1108                                                               : "request with",
1109                         ntohl(transport->tcp_xid));
1110         xs_tcp_check_fraghdr(transport);
1111 }
1112
1113 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1114                                        struct xdr_skb_reader *desc)
1115 {
1116         size_t len, used;
1117         u32 offset;
1118         char *p;
1119
1120         /*
1121          * We want transport->tcp_offset to be 8 at the end of this routine
1122          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1123          * When this function is called for the first time,
1124          * transport->tcp_offset is 4 (after having already read the xid).
1125          */
1126         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1127         len = sizeof(transport->tcp_calldir) - offset;
1128         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1129         p = ((char *) &transport->tcp_calldir) + offset;
1130         used = xdr_skb_read_bits(desc, p, len);
1131         transport->tcp_offset += used;
1132         if (used != len)
1133                 return;
1134         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1135         /*
1136          * We don't yet have the XDR buffer, so we will write the calldir
1137          * out after we get the buffer from the 'struct rpc_rqst'
1138          */
1139         switch (ntohl(transport->tcp_calldir)) {
1140         case RPC_REPLY:
1141                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1142                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1143                 transport->tcp_flags |= TCP_RPC_REPLY;
1144                 break;
1145         case RPC_CALL:
1146                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1147                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1148                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1149                 break;
1150         default:
1151                 dprintk("RPC:       invalid request message type\n");
1152                 xs_tcp_force_close(&transport->xprt);
1153         }
1154         xs_tcp_check_fraghdr(transport);
1155 }
1156
1157 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1158                                      struct xdr_skb_reader *desc,
1159                                      struct rpc_rqst *req)
1160 {
1161         struct sock_xprt *transport =
1162                                 container_of(xprt, struct sock_xprt, xprt);
1163         struct xdr_buf *rcvbuf;
1164         size_t len;
1165         ssize_t r;
1166
1167         rcvbuf = &req->rq_private_buf;
1168
1169         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1170                 /*
1171                  * Save the RPC direction in the XDR buffer
1172                  */
1173                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1174                         &transport->tcp_calldir,
1175                         sizeof(transport->tcp_calldir));
1176                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1177                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1178         }
1179
1180         len = desc->count;
1181         if (len > transport->tcp_reclen - transport->tcp_offset) {
1182                 struct xdr_skb_reader my_desc;
1183
1184                 len = transport->tcp_reclen - transport->tcp_offset;
1185                 memcpy(&my_desc, desc, sizeof(my_desc));
1186                 my_desc.count = len;
1187                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1188                                           &my_desc, xdr_skb_read_bits);
1189                 desc->count -= r;
1190                 desc->offset += r;
1191         } else
1192                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1193                                           desc, xdr_skb_read_bits);
1194
1195         if (r > 0) {
1196                 transport->tcp_copied += r;
1197                 transport->tcp_offset += r;
1198         }
1199         if (r != len) {
1200                 /* Error when copying to the receive buffer,
1201                  * usually because we weren't able to allocate
1202                  * additional buffer pages. All we can do now
1203                  * is turn off TCP_RCV_COPY_DATA, so the request
1204                  * will not receive any additional updates,
1205                  * and time out.
1206                  * Any remaining data from this record will
1207                  * be discarded.
1208                  */
1209                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1210                 dprintk("RPC:       XID %08x truncated request\n",
1211                                 ntohl(transport->tcp_xid));
1212                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1213                                 "tcp_offset = %u, tcp_reclen = %u\n",
1214                                 xprt, transport->tcp_copied,
1215                                 transport->tcp_offset, transport->tcp_reclen);
1216                 return;
1217         }
1218
1219         dprintk("RPC:       XID %08x read %Zd bytes\n",
1220                         ntohl(transport->tcp_xid), r);
1221         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1222                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1223                         transport->tcp_offset, transport->tcp_reclen);
1224
1225         if (transport->tcp_copied == req->rq_private_buf.buflen)
1226                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1227         else if (transport->tcp_offset == transport->tcp_reclen) {
1228                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1229                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1230         }
1231 }
1232
1233 /*
1234  * Finds the request corresponding to the RPC xid and invokes the common
1235  * tcp read code to read the data.
1236  */
1237 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1238                                     struct xdr_skb_reader *desc)
1239 {
1240         struct sock_xprt *transport =
1241                                 container_of(xprt, struct sock_xprt, xprt);
1242         struct rpc_rqst *req;
1243
1244         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1245
1246         /* Find and lock the request corresponding to this xid */
1247         spin_lock(&xprt->transport_lock);
1248         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1249         if (!req) {
1250                 dprintk("RPC:       XID %08x request not found!\n",
1251                                 ntohl(transport->tcp_xid));
1252                 spin_unlock(&xprt->transport_lock);
1253                 return -1;
1254         }
1255
1256         xs_tcp_read_common(xprt, desc, req);
1257
1258         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1259                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1260
1261         spin_unlock(&xprt->transport_lock);
1262         return 0;
1263 }
1264
1265 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1266 /*
1267  * Obtains an rpc_rqst previously allocated and invokes the common
1268  * tcp read code to read the data.  The result is placed in the callback
1269  * queue.
1270  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1271  * connection and return -1.
1272  */
1273 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1274                                        struct xdr_skb_reader *desc)
1275 {
1276         struct sock_xprt *transport =
1277                                 container_of(xprt, struct sock_xprt, xprt);
1278         struct rpc_rqst *req;
1279
1280         /* Look up and lock the request corresponding to the given XID */
1281         spin_lock(&xprt->transport_lock);
1282         req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1283         if (req == NULL) {
1284                 spin_unlock(&xprt->transport_lock);
1285                 printk(KERN_WARNING "Callback slot table overflowed\n");
1286                 xprt_force_disconnect(xprt);
1287                 return -1;
1288         }
1289
1290         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1291         xs_tcp_read_common(xprt, desc, req);
1292
1293         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1294                 xprt_complete_bc_request(req, transport->tcp_copied);
1295         spin_unlock(&xprt->transport_lock);
1296
1297         return 0;
1298 }
1299
1300 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1301                                         struct xdr_skb_reader *desc)
1302 {
1303         struct sock_xprt *transport =
1304                                 container_of(xprt, struct sock_xprt, xprt);
1305
1306         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1307                 xs_tcp_read_reply(xprt, desc) :
1308                 xs_tcp_read_callback(xprt, desc);
1309 }
1310 #else
1311 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1312                                         struct xdr_skb_reader *desc)
1313 {
1314         return xs_tcp_read_reply(xprt, desc);
1315 }
1316 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1317
1318 /*
1319  * Read data off the transport.  This can be either an RPC_CALL or an
1320  * RPC_REPLY.  Relay the processing to helper functions.
1321  */
1322 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1323                                     struct xdr_skb_reader *desc)
1324 {
1325         struct sock_xprt *transport =
1326                                 container_of(xprt, struct sock_xprt, xprt);
1327
1328         if (_xs_tcp_read_data(xprt, desc) == 0)
1329                 xs_tcp_check_fraghdr(transport);
1330         else {
1331                 /*
1332                  * The transport_lock protects the request handling.
1333                  * There's no need to hold it to update the tcp_flags.
1334                  */
1335                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1336         }
1337 }
1338
1339 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1340 {
1341         size_t len;
1342
1343         len = transport->tcp_reclen - transport->tcp_offset;
1344         if (len > desc->count)
1345                 len = desc->count;
1346         desc->count -= len;
1347         desc->offset += len;
1348         transport->tcp_offset += len;
1349         dprintk("RPC:       discarded %Zu bytes\n", len);
1350         xs_tcp_check_fraghdr(transport);
1351 }
1352
1353 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1354 {
1355         struct rpc_xprt *xprt = rd_desc->arg.data;
1356         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1357         struct xdr_skb_reader desc = {
1358                 .skb    = skb,
1359                 .offset = offset,
1360                 .count  = len,
1361         };
1362
1363         dprintk("RPC:       xs_tcp_data_recv started\n");
1364         do {
1365                 trace_xs_tcp_data_recv(transport);
1366                 /* Read in a new fragment marker if necessary */
1367                 /* Can we ever really expect to get completely empty fragments? */
1368                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1369                         xs_tcp_read_fraghdr(xprt, &desc);
1370                         continue;
1371                 }
1372                 /* Read in the xid if necessary */
1373                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1374                         xs_tcp_read_xid(transport, &desc);
1375                         continue;
1376                 }
1377                 /* Read in the call/reply flag */
1378                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1379                         xs_tcp_read_calldir(transport, &desc);
1380                         continue;
1381                 }
1382                 /* Read in the request data */
1383                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1384                         xs_tcp_read_data(xprt, &desc);
1385                         continue;
1386                 }
1387                 /* Skip over any trailing bytes on short reads */
1388                 xs_tcp_read_discard(transport, &desc);
1389         } while (desc.count);
1390         trace_xs_tcp_data_recv(transport);
1391         dprintk("RPC:       xs_tcp_data_recv done\n");
1392         return len - desc.count;
1393 }
1394
1395 /**
1396  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1397  * @sk: socket with data to read
1398  * @bytes: how much data to read
1399  *
1400  */
1401 static void xs_tcp_data_ready(struct sock *sk)
1402 {
1403         struct rpc_xprt *xprt;
1404         read_descriptor_t rd_desc;
1405         int read;
1406         unsigned long total = 0;
1407
1408         dprintk("RPC:       xs_tcp_data_ready...\n");
1409
1410         read_lock_bh(&sk->sk_callback_lock);
1411         if (!(xprt = xprt_from_sock(sk))) {
1412                 read = 0;
1413                 goto out;
1414         }
1415         /* Any data means we had a useful conversation, so
1416          * the we don't need to delay the next reconnect
1417          */
1418         if (xprt->reestablish_timeout)
1419                 xprt->reestablish_timeout = 0;
1420
1421         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1422         rd_desc.arg.data = xprt;
1423         do {
1424                 rd_desc.count = 65536;
1425                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1426                 if (read > 0)
1427                         total += read;
1428         } while (read > 0);
1429 out:
1430         trace_xs_tcp_data_ready(xprt, read, total);
1431         read_unlock_bh(&sk->sk_callback_lock);
1432 }
1433
1434 /*
1435  * Do the equivalent of linger/linger2 handling for dealing with
1436  * broken servers that don't close the socket in a timely
1437  * fashion
1438  */
1439 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1440                 unsigned long timeout)
1441 {
1442         struct sock_xprt *transport;
1443
1444         if (xprt_test_and_set_connecting(xprt))
1445                 return;
1446         set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1447         transport = container_of(xprt, struct sock_xprt, xprt);
1448         queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1449                            timeout);
1450 }
1451
1452 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1453 {
1454         struct sock_xprt *transport;
1455
1456         transport = container_of(xprt, struct sock_xprt, xprt);
1457
1458         if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1459             !cancel_delayed_work(&transport->connect_worker))
1460                 return;
1461         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1462         xprt_clear_connecting(xprt);
1463 }
1464
1465 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1466 {
1467         xs_sock_reset_connection_flags(xprt);
1468         /* Mark transport as closed and wake up all pending tasks */
1469         xprt_disconnect_done(xprt);
1470 }
1471
1472 /**
1473  * xs_tcp_state_change - callback to handle TCP socket state changes
1474  * @sk: socket whose state has changed
1475  *
1476  */
1477 static void xs_tcp_state_change(struct sock *sk)
1478 {
1479         struct rpc_xprt *xprt;
1480
1481         read_lock_bh(&sk->sk_callback_lock);
1482         if (!(xprt = xprt_from_sock(sk)))
1483                 goto out;
1484         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1485         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1486                         sk->sk_state, xprt_connected(xprt),
1487                         sock_flag(sk, SOCK_DEAD),
1488                         sock_flag(sk, SOCK_ZAPPED),
1489                         sk->sk_shutdown);
1490
1491         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1492         switch (sk->sk_state) {
1493         case TCP_ESTABLISHED:
1494                 spin_lock(&xprt->transport_lock);
1495                 if (!xprt_test_and_set_connected(xprt)) {
1496                         struct sock_xprt *transport = container_of(xprt,
1497                                         struct sock_xprt, xprt);
1498
1499                         /* Reset TCP record info */
1500                         transport->tcp_offset = 0;
1501                         transport->tcp_reclen = 0;
1502                         transport->tcp_copied = 0;
1503                         transport->tcp_flags =
1504                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1505                         xprt->connect_cookie++;
1506
1507                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1508                 }
1509                 spin_unlock(&xprt->transport_lock);
1510                 break;
1511         case TCP_FIN_WAIT1:
1512                 /* The client initiated a shutdown of the socket */
1513                 xprt->connect_cookie++;
1514                 xprt->reestablish_timeout = 0;
1515                 set_bit(XPRT_CLOSING, &xprt->state);
1516                 smp_mb__before_atomic();
1517                 clear_bit(XPRT_CONNECTED, &xprt->state);
1518                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1519                 smp_mb__after_atomic();
1520                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1521                 break;
1522         case TCP_CLOSE_WAIT:
1523                 /* The server initiated a shutdown of the socket */
1524                 xprt->connect_cookie++;
1525                 clear_bit(XPRT_CONNECTED, &xprt->state);
1526                 xs_tcp_force_close(xprt);
1527         case TCP_CLOSING:
1528                 /*
1529                  * If the server closed down the connection, make sure that
1530                  * we back off before reconnecting
1531                  */
1532                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1533                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1534                 break;
1535         case TCP_LAST_ACK:
1536                 set_bit(XPRT_CLOSING, &xprt->state);
1537                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1538                 smp_mb__before_atomic();
1539                 clear_bit(XPRT_CONNECTED, &xprt->state);
1540                 smp_mb__after_atomic();
1541                 break;
1542         case TCP_CLOSE:
1543                 xs_tcp_cancel_linger_timeout(xprt);
1544                 xs_sock_mark_closed(xprt);
1545         }
1546  out:
1547         read_unlock_bh(&sk->sk_callback_lock);
1548 }
1549
1550 static void xs_write_space(struct sock *sk)
1551 {
1552         struct socket *sock;
1553         struct rpc_xprt *xprt;
1554
1555         if (unlikely(!(sock = sk->sk_socket)))
1556                 return;
1557         clear_bit(SOCK_NOSPACE, &sock->flags);
1558
1559         if (unlikely(!(xprt = xprt_from_sock(sk))))
1560                 return;
1561         if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1562                 return;
1563
1564         xprt_write_space(xprt);
1565 }
1566
1567 /**
1568  * xs_udp_write_space - callback invoked when socket buffer space
1569  *                             becomes available
1570  * @sk: socket whose state has changed
1571  *
1572  * Called when more output buffer space is available for this socket.
1573  * We try not to wake our writers until they can make "significant"
1574  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1575  * with a bunch of small requests.
1576  */
1577 static void xs_udp_write_space(struct sock *sk)
1578 {
1579         read_lock_bh(&sk->sk_callback_lock);
1580
1581         /* from net/core/sock.c:sock_def_write_space */
1582         if (sock_writeable(sk))
1583                 xs_write_space(sk);
1584
1585         read_unlock_bh(&sk->sk_callback_lock);
1586 }
1587
1588 /**
1589  * xs_tcp_write_space - callback invoked when socket buffer space
1590  *                             becomes available
1591  * @sk: socket whose state has changed
1592  *
1593  * Called when more output buffer space is available for this socket.
1594  * We try not to wake our writers until they can make "significant"
1595  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1596  * with a bunch of small requests.
1597  */
1598 static void xs_tcp_write_space(struct sock *sk)
1599 {
1600         read_lock_bh(&sk->sk_callback_lock);
1601
1602         /* from net/core/stream.c:sk_stream_write_space */
1603         if (sk_stream_is_writeable(sk))
1604                 xs_write_space(sk);
1605
1606         read_unlock_bh(&sk->sk_callback_lock);
1607 }
1608
1609 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1610 {
1611         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1612         struct sock *sk = transport->inet;
1613
1614         if (transport->rcvsize) {
1615                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1616                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1617         }
1618         if (transport->sndsize) {
1619                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1620                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1621                 sk->sk_write_space(sk);
1622         }
1623 }
1624
1625 /**
1626  * xs_udp_set_buffer_size - set send and receive limits
1627  * @xprt: generic transport
1628  * @sndsize: requested size of send buffer, in bytes
1629  * @rcvsize: requested size of receive buffer, in bytes
1630  *
1631  * Set socket send and receive buffer size limits.
1632  */
1633 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1634 {
1635         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1636
1637         transport->sndsize = 0;
1638         if (sndsize)
1639                 transport->sndsize = sndsize + 1024;
1640         transport->rcvsize = 0;
1641         if (rcvsize)
1642                 transport->rcvsize = rcvsize + 1024;
1643
1644         xs_udp_do_set_buffer_size(xprt);
1645 }
1646
1647 /**
1648  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1649  * @task: task that timed out
1650  *
1651  * Adjust the congestion window after a retransmit timeout has occurred.
1652  */
1653 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1654 {
1655         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1656 }
1657
1658 static unsigned short xs_get_random_port(void)
1659 {
1660         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1661         unsigned short rand = (unsigned short) prandom_u32() % range;
1662         return rand + xprt_min_resvport;
1663 }
1664
1665 /**
1666  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1667  * @sock: socket
1668  *
1669  * Note that this function has to be called on all sockets that share the
1670  * same port, and it must be called before binding.
1671  */
1672 static void xs_sock_set_reuseport(struct socket *sock)
1673 {
1674         char opt = 1;
1675
1676         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt));
1677 }
1678
1679 static unsigned short xs_sock_getport(struct socket *sock)
1680 {
1681         struct sockaddr_storage buf;
1682         int buflen;
1683         unsigned short port = 0;
1684
1685         if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1686                 goto out;
1687         switch (buf.ss_family) {
1688         case AF_INET6:
1689                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1690                 break;
1691         case AF_INET:
1692                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1693         }
1694 out:
1695         return port;
1696 }
1697
1698 /**
1699  * xs_set_port - reset the port number in the remote endpoint address
1700  * @xprt: generic transport
1701  * @port: new port number
1702  *
1703  */
1704 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1705 {
1706         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1707
1708         rpc_set_port(xs_addr(xprt), port);
1709         xs_update_peer_port(xprt);
1710 }
1711
1712 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1713 {
1714         if (transport->srcport == 0)
1715                 transport->srcport = xs_sock_getport(sock);
1716 }
1717
1718 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1719 {
1720         unsigned short port = transport->srcport;
1721
1722         if (port == 0 && transport->xprt.resvport)
1723                 port = xs_get_random_port();
1724         return port;
1725 }
1726
1727 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1728 {
1729         if (transport->srcport != 0)
1730                 transport->srcport = 0;
1731         if (!transport->xprt.resvport)
1732                 return 0;
1733         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1734                 return xprt_max_resvport;
1735         return --port;
1736 }
1737 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1738 {
1739         struct sockaddr_storage myaddr;
1740         int err, nloop = 0;
1741         unsigned short port = xs_get_srcport(transport);
1742         unsigned short last;
1743
1744         /*
1745          * If we are asking for any ephemeral port (i.e. port == 0 &&
1746          * transport->xprt.resvport == 0), don't bind.  Let the local
1747          * port selection happen implicitly when the socket is used
1748          * (for example at connect time).
1749          *
1750          * This ensures that we can continue to establish TCP
1751          * connections even when all local ephemeral ports are already
1752          * a part of some TCP connection.  This makes no difference
1753          * for UDP sockets, but also doens't harm them.
1754          *
1755          * If we're asking for any reserved port (i.e. port == 0 &&
1756          * transport->xprt.resvport == 1) xs_get_srcport above will
1757          * ensure that port is non-zero and we will bind as needed.
1758          */
1759         if (port == 0)
1760                 return 0;
1761
1762         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1763         do {
1764                 rpc_set_port((struct sockaddr *)&myaddr, port);
1765                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1766                                 transport->xprt.addrlen);
1767                 if (err == 0) {
1768                         transport->srcport = port;
1769                         break;
1770                 }
1771                 last = port;
1772                 port = xs_next_srcport(transport, port);
1773                 if (port > last)
1774                         nloop++;
1775         } while (err == -EADDRINUSE && nloop != 2);
1776
1777         if (myaddr.ss_family == AF_INET)
1778                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1779                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1780                                 port, err ? "failed" : "ok", err);
1781         else
1782                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1783                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1784                                 port, err ? "failed" : "ok", err);
1785         return err;
1786 }
1787
1788 /*
1789  * We don't support autobind on AF_LOCAL sockets
1790  */
1791 static void xs_local_rpcbind(struct rpc_task *task)
1792 {
1793         rcu_read_lock();
1794         xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1795         rcu_read_unlock();
1796 }
1797
1798 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1799 {
1800 }
1801
1802 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1803 static struct lock_class_key xs_key[2];
1804 static struct lock_class_key xs_slock_key[2];
1805
1806 static inline void xs_reclassify_socketu(struct socket *sock)
1807 {
1808         struct sock *sk = sock->sk;
1809
1810         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1811                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1812 }
1813
1814 static inline void xs_reclassify_socket4(struct socket *sock)
1815 {
1816         struct sock *sk = sock->sk;
1817
1818         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1819                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1820 }
1821
1822 static inline void xs_reclassify_socket6(struct socket *sock)
1823 {
1824         struct sock *sk = sock->sk;
1825
1826         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1827                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1828 }
1829
1830 static inline void xs_reclassify_socket(int family, struct socket *sock)
1831 {
1832         WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1833         if (sock_owned_by_user(sock->sk))
1834                 return;
1835
1836         switch (family) {
1837         case AF_LOCAL:
1838                 xs_reclassify_socketu(sock);
1839                 break;
1840         case AF_INET:
1841                 xs_reclassify_socket4(sock);
1842                 break;
1843         case AF_INET6:
1844                 xs_reclassify_socket6(sock);
1845                 break;
1846         }
1847 }
1848 #else
1849 static inline void xs_reclassify_socketu(struct socket *sock)
1850 {
1851 }
1852
1853 static inline void xs_reclassify_socket4(struct socket *sock)
1854 {
1855 }
1856
1857 static inline void xs_reclassify_socket6(struct socket *sock)
1858 {
1859 }
1860
1861 static inline void xs_reclassify_socket(int family, struct socket *sock)
1862 {
1863 }
1864 #endif
1865
1866 static void xs_dummy_setup_socket(struct work_struct *work)
1867 {
1868 }
1869
1870 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1871                 struct sock_xprt *transport, int family, int type,
1872                 int protocol, bool reuseport)
1873 {
1874         struct socket *sock;
1875         int err;
1876
1877         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1878         if (err < 0) {
1879                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1880                                 protocol, -err);
1881                 goto out;
1882         }
1883         xs_reclassify_socket(family, sock);
1884
1885         if (reuseport)
1886                 xs_sock_set_reuseport(sock);
1887
1888         err = xs_bind(transport, sock);
1889         if (err) {
1890                 sock_release(sock);
1891                 goto out;
1892         }
1893
1894         return sock;
1895 out:
1896         return ERR_PTR(err);
1897 }
1898
1899 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1900                                       struct socket *sock)
1901 {
1902         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1903                                                                         xprt);
1904
1905         if (!transport->inet) {
1906                 struct sock *sk = sock->sk;
1907
1908                 write_lock_bh(&sk->sk_callback_lock);
1909
1910                 xs_save_old_callbacks(transport, sk);
1911
1912                 sk->sk_user_data = xprt;
1913                 sk->sk_data_ready = xs_local_data_ready;
1914                 sk->sk_write_space = xs_udp_write_space;
1915                 sk->sk_error_report = xs_error_report;
1916                 sk->sk_allocation = GFP_ATOMIC;
1917
1918                 xprt_clear_connected(xprt);
1919
1920                 /* Reset to new socket */
1921                 transport->sock = sock;
1922                 transport->inet = sk;
1923
1924                 write_unlock_bh(&sk->sk_callback_lock);
1925         }
1926
1927         /* Tell the socket layer to start connecting... */
1928         xprt->stat.connect_count++;
1929         xprt->stat.connect_start = jiffies;
1930         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1931 }
1932
1933 /**
1934  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1935  * @xprt: RPC transport to connect
1936  * @transport: socket transport to connect
1937  * @create_sock: function to create a socket of the correct type
1938  */
1939 static int xs_local_setup_socket(struct sock_xprt *transport)
1940 {
1941         struct rpc_xprt *xprt = &transport->xprt;
1942         struct socket *sock;
1943         int status = -EIO;
1944
1945         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1946         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1947                                         SOCK_STREAM, 0, &sock, 1);
1948         if (status < 0) {
1949                 dprintk("RPC:       can't create AF_LOCAL "
1950                         "transport socket (%d).\n", -status);
1951                 goto out;
1952         }
1953         xs_reclassify_socketu(sock);
1954
1955         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1956                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1957
1958         status = xs_local_finish_connecting(xprt, sock);
1959         trace_rpc_socket_connect(xprt, sock, status);
1960         switch (status) {
1961         case 0:
1962                 dprintk("RPC:       xprt %p connected to %s\n",
1963                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1964                 xprt_set_connected(xprt);
1965         case -ENOBUFS:
1966                 break;
1967         case -ENOENT:
1968                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1969                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1970                 break;
1971         case -ECONNREFUSED:
1972                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1973                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1974                 break;
1975         default:
1976                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1977                                 __func__, -status,
1978                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1979         }
1980
1981 out:
1982         xprt_clear_connecting(xprt);
1983         xprt_wake_pending_tasks(xprt, status);
1984         return status;
1985 }
1986
1987 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1988 {
1989         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1990         int ret;
1991
1992          if (RPC_IS_ASYNC(task)) {
1993                 /*
1994                  * We want the AF_LOCAL connect to be resolved in the
1995                  * filesystem namespace of the process making the rpc
1996                  * call.  Thus we connect synchronously.
1997                  *
1998                  * If we want to support asynchronous AF_LOCAL calls,
1999                  * we'll need to figure out how to pass a namespace to
2000                  * connect.
2001                  */
2002                 rpc_exit(task, -ENOTCONN);
2003                 return;
2004         }
2005         ret = xs_local_setup_socket(transport);
2006         if (ret && !RPC_IS_SOFTCONN(task))
2007                 msleep_interruptible(15000);
2008 }
2009
2010 #ifdef CONFIG_SUNRPC_SWAP
2011 static void xs_set_memalloc(struct rpc_xprt *xprt)
2012 {
2013         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2014                         xprt);
2015
2016         if (xprt->swapper)
2017                 sk_set_memalloc(transport->inet);
2018 }
2019
2020 /**
2021  * xs_swapper - Tag this transport as being used for swap.
2022  * @xprt: transport to tag
2023  * @enable: enable/disable
2024  *
2025  */
2026 int xs_swapper(struct rpc_xprt *xprt, int enable)
2027 {
2028         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2029                         xprt);
2030         int err = 0;
2031
2032         if (enable) {
2033                 xprt->swapper++;
2034                 xs_set_memalloc(xprt);
2035         } else if (xprt->swapper) {
2036                 xprt->swapper--;
2037                 sk_clear_memalloc(transport->inet);
2038         }
2039
2040         return err;
2041 }
2042 EXPORT_SYMBOL_GPL(xs_swapper);
2043 #else
2044 static void xs_set_memalloc(struct rpc_xprt *xprt)
2045 {
2046 }
2047 #endif
2048
2049 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2050 {
2051         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2052
2053         if (!transport->inet) {
2054                 struct sock *sk = sock->sk;
2055
2056                 write_lock_bh(&sk->sk_callback_lock);
2057
2058                 xs_save_old_callbacks(transport, sk);
2059
2060                 sk->sk_user_data = xprt;
2061                 sk->sk_data_ready = xs_udp_data_ready;
2062                 sk->sk_write_space = xs_udp_write_space;
2063                 sk->sk_allocation = GFP_ATOMIC;
2064
2065                 xprt_set_connected(xprt);
2066
2067                 /* Reset to new socket */
2068                 transport->sock = sock;
2069                 transport->inet = sk;
2070
2071                 xs_set_memalloc(xprt);
2072
2073                 write_unlock_bh(&sk->sk_callback_lock);
2074         }
2075         xs_udp_do_set_buffer_size(xprt);
2076 }
2077
2078 static void xs_udp_setup_socket(struct work_struct *work)
2079 {
2080         struct sock_xprt *transport =
2081                 container_of(work, struct sock_xprt, connect_worker.work);
2082         struct rpc_xprt *xprt = &transport->xprt;
2083         struct socket *sock = transport->sock;
2084         int status = -EIO;
2085
2086         /* Start by resetting any existing state */
2087         xs_reset_transport(transport);
2088         sock = xs_create_sock(xprt, transport,
2089                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2090                         IPPROTO_UDP, false);
2091         if (IS_ERR(sock))
2092                 goto out;
2093
2094         dprintk("RPC:       worker connecting xprt %p via %s to "
2095                                 "%s (port %s)\n", xprt,
2096                         xprt->address_strings[RPC_DISPLAY_PROTO],
2097                         xprt->address_strings[RPC_DISPLAY_ADDR],
2098                         xprt->address_strings[RPC_DISPLAY_PORT]);
2099
2100         xs_udp_finish_connecting(xprt, sock);
2101         trace_rpc_socket_connect(xprt, sock, 0);
2102         status = 0;
2103 out:
2104         xprt_clear_connecting(xprt);
2105         xprt_wake_pending_tasks(xprt, status);
2106 }
2107
2108 /*
2109  * We need to preserve the port number so the reply cache on the server can
2110  * find our cached RPC replies when we get around to reconnecting.
2111  */
2112 static void xs_abort_connection(struct sock_xprt *transport)
2113 {
2114         int result;
2115         struct sockaddr any;
2116
2117         dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2118
2119         /*
2120          * Disconnect the transport socket by doing a connect operation
2121          * with AF_UNSPEC.  This should return immediately...
2122          */
2123         memset(&any, 0, sizeof(any));
2124         any.sa_family = AF_UNSPEC;
2125         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2126         trace_rpc_socket_reset_connection(&transport->xprt,
2127                         transport->sock, result);
2128         if (!result)
2129                 xs_sock_reset_connection_flags(&transport->xprt);
2130         dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2131 }
2132
2133 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2134 {
2135         unsigned int state = transport->inet->sk_state;
2136
2137         if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2138                 /* we don't need to abort the connection if the socket
2139                  * hasn't undergone a shutdown
2140                  */
2141                 if (transport->inet->sk_shutdown == 0)
2142                         return;
2143                 dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2144                                 __func__, transport->inet->sk_shutdown);
2145         }
2146         if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2147                 /* we don't need to abort the connection if the socket
2148                  * hasn't undergone a shutdown
2149                  */
2150                 if (transport->inet->sk_shutdown == 0)
2151                         return;
2152                 dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2153                                 "sk_shutdown set to %d\n",
2154                                 __func__, transport->inet->sk_shutdown);
2155         }
2156         xs_abort_connection(transport);
2157 }
2158
2159 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2160 {
2161         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2162         int ret = -ENOTCONN;
2163
2164         if (!transport->inet) {
2165                 struct sock *sk = sock->sk;
2166                 unsigned int keepidle = xprt->timeout->to_initval / HZ;
2167                 unsigned int keepcnt = xprt->timeout->to_retries + 1;
2168                 unsigned int opt_on = 1;
2169
2170                 /* TCP Keepalive options */
2171                 kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2172                                 (char *)&opt_on, sizeof(opt_on));
2173                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2174                                 (char *)&keepidle, sizeof(keepidle));
2175                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2176                                 (char *)&keepidle, sizeof(keepidle));
2177                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2178                                 (char *)&keepcnt, sizeof(keepcnt));
2179
2180                 write_lock_bh(&sk->sk_callback_lock);
2181
2182                 xs_save_old_callbacks(transport, sk);
2183
2184                 sk->sk_user_data = xprt;
2185                 sk->sk_data_ready = xs_tcp_data_ready;
2186                 sk->sk_state_change = xs_tcp_state_change;
2187                 sk->sk_write_space = xs_tcp_write_space;
2188                 sk->sk_error_report = xs_error_report;
2189                 sk->sk_allocation = GFP_ATOMIC;
2190
2191                 /* socket options */
2192                 sock_reset_flag(sk, SOCK_LINGER);
2193                 tcp_sk(sk)->linger2 = 0;
2194                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2195
2196                 xprt_clear_connected(xprt);
2197
2198                 /* Reset to new socket */
2199                 transport->sock = sock;
2200                 transport->inet = sk;
2201
2202                 write_unlock_bh(&sk->sk_callback_lock);
2203         }
2204
2205         if (!xprt_bound(xprt))
2206                 goto out;
2207
2208         xs_set_memalloc(xprt);
2209
2210         /* Tell the socket layer to start connecting... */
2211         xprt->stat.connect_count++;
2212         xprt->stat.connect_start = jiffies;
2213         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2214         switch (ret) {
2215         case 0:
2216                 xs_set_srcport(transport, sock);
2217         case -EINPROGRESS:
2218                 /* SYN_SENT! */
2219                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2220                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2221         }
2222 out:
2223         return ret;
2224 }
2225
2226 /**
2227  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2228  * @xprt: RPC transport to connect
2229  * @transport: socket transport to connect
2230  * @create_sock: function to create a socket of the correct type
2231  *
2232  * Invoked by a work queue tasklet.
2233  */
2234 static void xs_tcp_setup_socket(struct work_struct *work)
2235 {
2236         struct sock_xprt *transport =
2237                 container_of(work, struct sock_xprt, connect_worker.work);
2238         struct socket *sock = transport->sock;
2239         struct rpc_xprt *xprt = &transport->xprt;
2240         int status = -EIO;
2241
2242         if (!sock) {
2243                 clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2244                 sock = xs_create_sock(xprt, transport,
2245                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2246                                 IPPROTO_TCP, true);
2247                 if (IS_ERR(sock)) {
2248                         status = PTR_ERR(sock);
2249                         goto out;
2250                 }
2251         } else {
2252                 int abort_and_exit;
2253
2254                 abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2255                                 &xprt->state);
2256                 /* "close" the socket, preserving the local port */
2257                 set_bit(XPRT_CONNECTION_REUSE, &xprt->state);
2258                 xs_tcp_reuse_connection(transport);
2259                 clear_bit(XPRT_CONNECTION_REUSE, &xprt->state);
2260
2261                 if (abort_and_exit)
2262                         goto out_eagain;
2263         }
2264
2265         dprintk("RPC:       worker connecting xprt %p via %s to "
2266                                 "%s (port %s)\n", xprt,
2267                         xprt->address_strings[RPC_DISPLAY_PROTO],
2268                         xprt->address_strings[RPC_DISPLAY_ADDR],
2269                         xprt->address_strings[RPC_DISPLAY_PORT]);
2270
2271         status = xs_tcp_finish_connecting(xprt, sock);
2272         trace_rpc_socket_connect(xprt, sock, status);
2273         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2274                         xprt, -status, xprt_connected(xprt),
2275                         sock->sk->sk_state);
2276         switch (status) {
2277         default:
2278                 printk("%s: connect returned unhandled error %d\n",
2279                         __func__, status);
2280         case -EADDRNOTAVAIL:
2281                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2282                  * and retry
2283                  */
2284                 xs_tcp_force_close(xprt);
2285                 break;
2286         case 0:
2287         case -EINPROGRESS:
2288         case -EALREADY:
2289                 xprt_clear_connecting(xprt);
2290                 return;
2291         case -EINVAL:
2292                 /* Happens, for instance, if the user specified a link
2293                  * local IPv6 address without a scope-id.
2294                  */
2295         case -ECONNREFUSED:
2296         case -ECONNRESET:
2297         case -ENETUNREACH:
2298         case -EADDRINUSE:
2299         case -ENOBUFS:
2300                 /* retry with existing socket, after a delay */
2301                 goto out;
2302         }
2303 out_eagain:
2304         status = -EAGAIN;
2305 out:
2306         xprt_clear_connecting(xprt);
2307         xprt_wake_pending_tasks(xprt, status);
2308 }
2309
2310 /**
2311  * xs_connect - connect a socket to a remote endpoint
2312  * @xprt: pointer to transport structure
2313  * @task: address of RPC task that manages state of connect request
2314  *
2315  * TCP: If the remote end dropped the connection, delay reconnecting.
2316  *
2317  * UDP socket connects are synchronous, but we use a work queue anyway
2318  * to guarantee that even unprivileged user processes can set up a
2319  * socket on a privileged port.
2320  *
2321  * If a UDP socket connect fails, the delay behavior here prevents
2322  * retry floods (hard mounts).
2323  */
2324 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2325 {
2326         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2327
2328         if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2329                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2330                                 "seconds\n",
2331                                 xprt, xprt->reestablish_timeout / HZ);
2332                 queue_delayed_work(rpciod_workqueue,
2333                                    &transport->connect_worker,
2334                                    xprt->reestablish_timeout);
2335                 xprt->reestablish_timeout <<= 1;
2336                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2337                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2338                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2339                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2340         } else {
2341                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2342                 queue_delayed_work(rpciod_workqueue,
2343                                    &transport->connect_worker, 0);
2344         }
2345 }
2346
2347 /**
2348  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2349  * @xprt: rpc_xprt struct containing statistics
2350  * @seq: output file
2351  *
2352  */
2353 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2354 {
2355         long idle_time = 0;
2356
2357         if (xprt_connected(xprt))
2358                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2359
2360         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2361                         "%llu %llu %lu %llu %llu\n",
2362                         xprt->stat.bind_count,
2363                         xprt->stat.connect_count,
2364                         xprt->stat.connect_time,
2365                         idle_time,
2366                         xprt->stat.sends,
2367                         xprt->stat.recvs,
2368                         xprt->stat.bad_xids,
2369                         xprt->stat.req_u,
2370                         xprt->stat.bklog_u,
2371                         xprt->stat.max_slots,
2372                         xprt->stat.sending_u,
2373                         xprt->stat.pending_u);
2374 }
2375
2376 /**
2377  * xs_udp_print_stats - display UDP socket-specifc stats
2378  * @xprt: rpc_xprt struct containing statistics
2379  * @seq: output file
2380  *
2381  */
2382 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2383 {
2384         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2385
2386         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2387                         "%lu %llu %llu\n",
2388                         transport->srcport,
2389                         xprt->stat.bind_count,
2390                         xprt->stat.sends,
2391                         xprt->stat.recvs,
2392                         xprt->stat.bad_xids,
2393                         xprt->stat.req_u,
2394                         xprt->stat.bklog_u,
2395                         xprt->stat.max_slots,
2396                         xprt->stat.sending_u,
2397                         xprt->stat.pending_u);
2398 }
2399
2400 /**
2401  * xs_tcp_print_stats - display TCP socket-specifc stats
2402  * @xprt: rpc_xprt struct containing statistics
2403  * @seq: output file
2404  *
2405  */
2406 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2407 {
2408         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2409         long idle_time = 0;
2410
2411         if (xprt_connected(xprt))
2412                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2413
2414         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2415                         "%llu %llu %lu %llu %llu\n",
2416                         transport->srcport,
2417                         xprt->stat.bind_count,
2418                         xprt->stat.connect_count,
2419                         xprt->stat.connect_time,
2420                         idle_time,
2421                         xprt->stat.sends,
2422                         xprt->stat.recvs,
2423                         xprt->stat.bad_xids,
2424                         xprt->stat.req_u,
2425                         xprt->stat.bklog_u,
2426                         xprt->stat.max_slots,
2427                         xprt->stat.sending_u,
2428                         xprt->stat.pending_u);
2429 }
2430
2431 /*
2432  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2433  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2434  * to use the server side send routines.
2435  */
2436 static void *bc_malloc(struct rpc_task *task, size_t size)
2437 {
2438         struct page *page;
2439         struct rpc_buffer *buf;
2440
2441         WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2442         if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2443                 return NULL;
2444
2445         page = alloc_page(GFP_KERNEL);
2446         if (!page)
2447                 return NULL;
2448
2449         buf = page_address(page);
2450         buf->len = PAGE_SIZE;
2451
2452         return buf->data;
2453 }
2454
2455 /*
2456  * Free the space allocated in the bc_alloc routine
2457  */
2458 static void bc_free(void *buffer)
2459 {
2460         struct rpc_buffer *buf;
2461
2462         if (!buffer)
2463                 return;
2464
2465         buf = container_of(buffer, struct rpc_buffer, data);
2466         free_page((unsigned long)buf);
2467 }
2468
2469 /*
2470  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2471  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2472  */
2473 static int bc_sendto(struct rpc_rqst *req)
2474 {
2475         int len;
2476         struct xdr_buf *xbufp = &req->rq_snd_buf;
2477         struct rpc_xprt *xprt = req->rq_xprt;
2478         struct sock_xprt *transport =
2479                                 container_of(xprt, struct sock_xprt, xprt);
2480         struct socket *sock = transport->sock;
2481         unsigned long headoff;
2482         unsigned long tailoff;
2483
2484         xs_encode_stream_record_marker(xbufp);
2485
2486         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2487         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2488         len = svc_send_common(sock, xbufp,
2489                               virt_to_page(xbufp->head[0].iov_base), headoff,
2490                               xbufp->tail[0].iov_base, tailoff);
2491
2492         if (len != xbufp->len) {
2493                 printk(KERN_NOTICE "Error sending entire callback!\n");
2494                 len = -EAGAIN;
2495         }
2496
2497         return len;
2498 }
2499
2500 /*
2501  * The send routine. Borrows from svc_send
2502  */
2503 static int bc_send_request(struct rpc_task *task)
2504 {
2505         struct rpc_rqst *req = task->tk_rqstp;
2506         struct svc_xprt *xprt;
2507         u32                     len;
2508
2509         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2510         /*
2511          * Get the server socket associated with this callback xprt
2512          */
2513         xprt = req->rq_xprt->bc_xprt;
2514
2515         /*
2516          * Grab the mutex to serialize data as the connection is shared
2517          * with the fore channel
2518          */
2519         if (!mutex_trylock(&xprt->xpt_mutex)) {
2520                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2521                 if (!mutex_trylock(&xprt->xpt_mutex))
2522                         return -EAGAIN;
2523                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2524         }
2525         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2526                 len = -ENOTCONN;
2527         else
2528                 len = bc_sendto(req);
2529         mutex_unlock(&xprt->xpt_mutex);
2530
2531         if (len > 0)
2532                 len = 0;
2533
2534         return len;
2535 }
2536
2537 /*
2538  * The close routine. Since this is client initiated, we do nothing
2539  */
2540
2541 static void bc_close(struct rpc_xprt *xprt)
2542 {
2543 }
2544
2545 /*
2546  * The xprt destroy routine. Again, because this connection is client
2547  * initiated, we do nothing
2548  */
2549
2550 static void bc_destroy(struct rpc_xprt *xprt)
2551 {
2552         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2553
2554         xs_xprt_free(xprt);
2555         module_put(THIS_MODULE);
2556 }
2557
2558 static struct rpc_xprt_ops xs_local_ops = {
2559         .reserve_xprt           = xprt_reserve_xprt,
2560         .release_xprt           = xs_tcp_release_xprt,
2561         .alloc_slot             = xprt_alloc_slot,
2562         .rpcbind                = xs_local_rpcbind,
2563         .set_port               = xs_local_set_port,
2564         .connect                = xs_local_connect,
2565         .buf_alloc              = rpc_malloc,
2566         .buf_free               = rpc_free,
2567         .send_request           = xs_local_send_request,
2568         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2569         .close                  = xs_close,
2570         .destroy                = xs_destroy,
2571         .print_stats            = xs_local_print_stats,
2572 };
2573
2574 static struct rpc_xprt_ops xs_udp_ops = {
2575         .set_buffer_size        = xs_udp_set_buffer_size,
2576         .reserve_xprt           = xprt_reserve_xprt_cong,
2577         .release_xprt           = xprt_release_xprt_cong,
2578         .alloc_slot             = xprt_alloc_slot,
2579         .rpcbind                = rpcb_getport_async,
2580         .set_port               = xs_set_port,
2581         .connect                = xs_connect,
2582         .buf_alloc              = rpc_malloc,
2583         .buf_free               = rpc_free,
2584         .send_request           = xs_udp_send_request,
2585         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2586         .timer                  = xs_udp_timer,
2587         .release_request        = xprt_release_rqst_cong,
2588         .close                  = xs_close,
2589         .destroy                = xs_destroy,
2590         .print_stats            = xs_udp_print_stats,
2591 };
2592
2593 static struct rpc_xprt_ops xs_tcp_ops = {
2594         .reserve_xprt           = xprt_reserve_xprt,
2595         .release_xprt           = xs_tcp_release_xprt,
2596         .alloc_slot             = xprt_lock_and_alloc_slot,
2597         .rpcbind                = rpcb_getport_async,
2598         .set_port               = xs_set_port,
2599         .connect                = xs_connect,
2600         .buf_alloc              = rpc_malloc,
2601         .buf_free               = rpc_free,
2602         .send_request           = xs_tcp_send_request,
2603         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2604         .close                  = xs_tcp_close,
2605         .destroy                = xs_destroy,
2606         .print_stats            = xs_tcp_print_stats,
2607 };
2608
2609 /*
2610  * The rpc_xprt_ops for the server backchannel
2611  */
2612
2613 static struct rpc_xprt_ops bc_tcp_ops = {
2614         .reserve_xprt           = xprt_reserve_xprt,
2615         .release_xprt           = xprt_release_xprt,
2616         .alloc_slot             = xprt_alloc_slot,
2617         .buf_alloc              = bc_malloc,
2618         .buf_free               = bc_free,
2619         .send_request           = bc_send_request,
2620         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2621         .close                  = bc_close,
2622         .destroy                = bc_destroy,
2623         .print_stats            = xs_tcp_print_stats,
2624 };
2625
2626 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2627 {
2628         static const struct sockaddr_in sin = {
2629                 .sin_family             = AF_INET,
2630                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2631         };
2632         static const struct sockaddr_in6 sin6 = {
2633                 .sin6_family            = AF_INET6,
2634                 .sin6_addr              = IN6ADDR_ANY_INIT,
2635         };
2636
2637         switch (family) {
2638         case AF_LOCAL:
2639                 break;
2640         case AF_INET:
2641                 memcpy(sap, &sin, sizeof(sin));
2642                 break;
2643         case AF_INET6:
2644                 memcpy(sap, &sin6, sizeof(sin6));
2645                 break;
2646         default:
2647                 dprintk("RPC:       %s: Bad address family\n", __func__);
2648                 return -EAFNOSUPPORT;
2649         }
2650         return 0;
2651 }
2652
2653 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2654                                       unsigned int slot_table_size,
2655                                       unsigned int max_slot_table_size)
2656 {
2657         struct rpc_xprt *xprt;
2658         struct sock_xprt *new;
2659
2660         if (args->addrlen > sizeof(xprt->addr)) {
2661                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2662                 return ERR_PTR(-EBADF);
2663         }
2664
2665         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2666                         max_slot_table_size);
2667         if (xprt == NULL) {
2668                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2669                                 "rpc_xprt\n");
2670                 return ERR_PTR(-ENOMEM);
2671         }
2672
2673         new = container_of(xprt, struct sock_xprt, xprt);
2674         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2675         xprt->addrlen = args->addrlen;
2676         if (args->srcaddr)
2677                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2678         else {
2679                 int err;
2680                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2681                                         (struct sockaddr *)&new->srcaddr);
2682                 if (err != 0) {
2683                         xprt_free(xprt);
2684                         return ERR_PTR(err);
2685                 }
2686         }
2687
2688         return xprt;
2689 }
2690
2691 static const struct rpc_timeout xs_local_default_timeout = {
2692         .to_initval = 10 * HZ,
2693         .to_maxval = 10 * HZ,
2694         .to_retries = 2,
2695 };
2696
2697 /**
2698  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2699  * @args: rpc transport creation arguments
2700  *
2701  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2702  */
2703 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2704 {
2705         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2706         struct sock_xprt *transport;
2707         struct rpc_xprt *xprt;
2708         struct rpc_xprt *ret;
2709
2710         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2711                         xprt_max_tcp_slot_table_entries);
2712         if (IS_ERR(xprt))
2713                 return xprt;
2714         transport = container_of(xprt, struct sock_xprt, xprt);
2715
2716         xprt->prot = 0;
2717         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2718         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2719
2720         xprt->bind_timeout = XS_BIND_TO;
2721         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2722         xprt->idle_timeout = XS_IDLE_DISC_TO;
2723
2724         xprt->ops = &xs_local_ops;
2725         xprt->timeout = &xs_local_default_timeout;
2726
2727         INIT_DELAYED_WORK(&transport->connect_worker,
2728                         xs_dummy_setup_socket);
2729
2730         switch (sun->sun_family) {
2731         case AF_LOCAL:
2732                 if (sun->sun_path[0] != '/') {
2733                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2734                                         sun->sun_path);
2735                         ret = ERR_PTR(-EINVAL);
2736                         goto out_err;
2737                 }
2738                 xprt_set_bound(xprt);
2739                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2740                 ret = ERR_PTR(xs_local_setup_socket(transport));
2741                 if (ret)
2742                         goto out_err;
2743                 break;
2744         default:
2745                 ret = ERR_PTR(-EAFNOSUPPORT);
2746                 goto out_err;
2747         }
2748
2749         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2750                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2751
2752         if (try_module_get(THIS_MODULE))
2753                 return xprt;
2754         ret = ERR_PTR(-EINVAL);
2755 out_err:
2756         xs_xprt_free(xprt);
2757         return ret;
2758 }
2759
2760 static const struct rpc_timeout xs_udp_default_timeout = {
2761         .to_initval = 5 * HZ,
2762         .to_maxval = 30 * HZ,
2763         .to_increment = 5 * HZ,
2764         .to_retries = 5,
2765 };
2766
2767 /**
2768  * xs_setup_udp - Set up transport to use a UDP socket
2769  * @args: rpc transport creation arguments
2770  *
2771  */
2772 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2773 {
2774         struct sockaddr *addr = args->dstaddr;
2775         struct rpc_xprt *xprt;
2776         struct sock_xprt *transport;
2777         struct rpc_xprt *ret;
2778
2779         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2780                         xprt_udp_slot_table_entries);
2781         if (IS_ERR(xprt))
2782                 return xprt;
2783         transport = container_of(xprt, struct sock_xprt, xprt);
2784
2785         xprt->prot = IPPROTO_UDP;
2786         xprt->tsh_size = 0;
2787         /* XXX: header size can vary due to auth type, IPv6, etc. */
2788         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2789
2790         xprt->bind_timeout = XS_BIND_TO;
2791         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2792         xprt->idle_timeout = XS_IDLE_DISC_TO;
2793
2794         xprt->ops = &xs_udp_ops;
2795
2796         xprt->timeout = &xs_udp_default_timeout;
2797
2798         switch (addr->sa_family) {
2799         case AF_INET:
2800                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2801                         xprt_set_bound(xprt);
2802
2803                 INIT_DELAYED_WORK(&transport->connect_worker,
2804                                         xs_udp_setup_socket);
2805                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2806                 break;
2807         case AF_INET6:
2808                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2809                         xprt_set_bound(xprt);
2810
2811                 INIT_DELAYED_WORK(&transport->connect_worker,
2812                                         xs_udp_setup_socket);
2813                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2814                 break;
2815         default:
2816                 ret = ERR_PTR(-EAFNOSUPPORT);
2817                 goto out_err;
2818         }
2819
2820         if (xprt_bound(xprt))
2821                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2822                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2823                                 xprt->address_strings[RPC_DISPLAY_PORT],
2824                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2825         else
2826                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2827                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2828                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2829
2830         if (try_module_get(THIS_MODULE))
2831                 return xprt;
2832         ret = ERR_PTR(-EINVAL);
2833 out_err:
2834         xs_xprt_free(xprt);
2835         return ret;
2836 }
2837
2838 static const struct rpc_timeout xs_tcp_default_timeout = {
2839         .to_initval = 60 * HZ,
2840         .to_maxval = 60 * HZ,
2841         .to_retries = 2,
2842 };
2843
2844 /**
2845  * xs_setup_tcp - Set up transport to use a TCP socket
2846  * @args: rpc transport creation arguments
2847  *
2848  */
2849 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2850 {
2851         struct sockaddr *addr = args->dstaddr;
2852         struct rpc_xprt *xprt;
2853         struct sock_xprt *transport;
2854         struct rpc_xprt *ret;
2855         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2856
2857         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2858                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2859
2860         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2861                         max_slot_table_size);
2862         if (IS_ERR(xprt))
2863                 return xprt;
2864         transport = container_of(xprt, struct sock_xprt, xprt);
2865
2866         xprt->prot = IPPROTO_TCP;
2867         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2868         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2869
2870         xprt->bind_timeout = XS_BIND_TO;
2871         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2872         xprt->idle_timeout = XS_IDLE_DISC_TO;
2873
2874         xprt->ops = &xs_tcp_ops;
2875         xprt->timeout = &xs_tcp_default_timeout;
2876
2877         switch (addr->sa_family) {
2878         case AF_INET:
2879                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2880                         xprt_set_bound(xprt);
2881
2882                 INIT_DELAYED_WORK(&transport->connect_worker,
2883                                         xs_tcp_setup_socket);
2884                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2885                 break;
2886         case AF_INET6:
2887                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2888                         xprt_set_bound(xprt);
2889
2890                 INIT_DELAYED_WORK(&transport->connect_worker,
2891                                         xs_tcp_setup_socket);
2892                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2893                 break;
2894         default:
2895                 ret = ERR_PTR(-EAFNOSUPPORT);
2896                 goto out_err;
2897         }
2898
2899         if (xprt_bound(xprt))
2900                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2901                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2902                                 xprt->address_strings[RPC_DISPLAY_PORT],
2903                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2904         else
2905                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2906                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2907                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2908
2909         if (try_module_get(THIS_MODULE))
2910                 return xprt;
2911         ret = ERR_PTR(-EINVAL);
2912 out_err:
2913         xs_xprt_free(xprt);
2914         return ret;
2915 }
2916
2917 /**
2918  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2919  * @args: rpc transport creation arguments
2920  *
2921  */
2922 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2923 {
2924         struct sockaddr *addr = args->dstaddr;
2925         struct rpc_xprt *xprt;
2926         struct sock_xprt *transport;
2927         struct svc_sock *bc_sock;
2928         struct rpc_xprt *ret;
2929
2930         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2931                         xprt_tcp_slot_table_entries);
2932         if (IS_ERR(xprt))
2933                 return xprt;
2934         transport = container_of(xprt, struct sock_xprt, xprt);
2935
2936         xprt->prot = IPPROTO_TCP;
2937         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2938         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2939         xprt->timeout = &xs_tcp_default_timeout;
2940
2941         /* backchannel */
2942         xprt_set_bound(xprt);
2943         xprt->bind_timeout = 0;
2944         xprt->reestablish_timeout = 0;
2945         xprt->idle_timeout = 0;
2946
2947         xprt->ops = &bc_tcp_ops;
2948
2949         switch (addr->sa_family) {
2950         case AF_INET:
2951                 xs_format_peer_addresses(xprt, "tcp",
2952                                          RPCBIND_NETID_TCP);
2953                 break;
2954         case AF_INET6:
2955                 xs_format_peer_addresses(xprt, "tcp",
2956                                    RPCBIND_NETID_TCP6);
2957                 break;
2958         default:
2959                 ret = ERR_PTR(-EAFNOSUPPORT);
2960                 goto out_err;
2961         }
2962
2963         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2964                         xprt->address_strings[RPC_DISPLAY_ADDR],
2965                         xprt->address_strings[RPC_DISPLAY_PORT],
2966                         xprt->address_strings[RPC_DISPLAY_PROTO]);
2967
2968         /*
2969          * Once we've associated a backchannel xprt with a connection,
2970          * we want to keep it around as long as the connection lasts,
2971          * in case we need to start using it for a backchannel again;
2972          * this reference won't be dropped until bc_xprt is destroyed.
2973          */
2974         xprt_get(xprt);
2975         args->bc_xprt->xpt_bc_xprt = xprt;
2976         xprt->bc_xprt = args->bc_xprt;
2977         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2978         transport->sock = bc_sock->sk_sock;
2979         transport->inet = bc_sock->sk_sk;
2980
2981         /*
2982          * Since we don't want connections for the backchannel, we set
2983          * the xprt status to connected
2984          */
2985         xprt_set_connected(xprt);
2986
2987         if (try_module_get(THIS_MODULE))
2988                 return xprt;
2989
2990         args->bc_xprt->xpt_bc_xprt = NULL;
2991         xprt_put(xprt);
2992         ret = ERR_PTR(-EINVAL);
2993 out_err:
2994         xs_xprt_free(xprt);
2995         return ret;
2996 }
2997
2998 static struct xprt_class        xs_local_transport = {
2999         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3000         .name           = "named UNIX socket",
3001         .owner          = THIS_MODULE,
3002         .ident          = XPRT_TRANSPORT_LOCAL,
3003         .setup          = xs_setup_local,
3004 };
3005
3006 static struct xprt_class        xs_udp_transport = {
3007         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3008         .name           = "udp",
3009         .owner          = THIS_MODULE,
3010         .ident          = XPRT_TRANSPORT_UDP,
3011         .setup          = xs_setup_udp,
3012 };
3013
3014 static struct xprt_class        xs_tcp_transport = {
3015         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3016         .name           = "tcp",
3017         .owner          = THIS_MODULE,
3018         .ident          = XPRT_TRANSPORT_TCP,
3019         .setup          = xs_setup_tcp,
3020 };
3021
3022 static struct xprt_class        xs_bc_tcp_transport = {
3023         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3024         .name           = "tcp NFSv4.1 backchannel",
3025         .owner          = THIS_MODULE,
3026         .ident          = XPRT_TRANSPORT_BC_TCP,
3027         .setup          = xs_setup_bc_tcp,
3028 };
3029
3030 /**
3031  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3032  *
3033  */
3034 int init_socket_xprt(void)
3035 {
3036 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3037         if (!sunrpc_table_header)
3038                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3039 #endif
3040
3041         xprt_register_transport(&xs_local_transport);
3042         xprt_register_transport(&xs_udp_transport);
3043         xprt_register_transport(&xs_tcp_transport);
3044         xprt_register_transport(&xs_bc_tcp_transport);
3045
3046         return 0;
3047 }
3048
3049 /**
3050  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3051  *
3052  */
3053 void cleanup_socket_xprt(void)
3054 {
3055 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3056         if (sunrpc_table_header) {
3057                 unregister_sysctl_table(sunrpc_table_header);
3058                 sunrpc_table_header = NULL;
3059         }
3060 #endif
3061
3062         xprt_unregister_transport(&xs_local_transport);
3063         xprt_unregister_transport(&xs_udp_transport);
3064         xprt_unregister_transport(&xs_tcp_transport);
3065         xprt_unregister_transport(&xs_bc_tcp_transport);
3066 }
3067
3068 static int param_set_uint_minmax(const char *val,
3069                 const struct kernel_param *kp,
3070                 unsigned int min, unsigned int max)
3071 {
3072         unsigned int num;
3073         int ret;
3074
3075         if (!val)
3076                 return -EINVAL;
3077         ret = kstrtouint(val, 0, &num);
3078         if (ret == -EINVAL || num < min || num > max)
3079                 return -EINVAL;
3080         *((unsigned int *)kp->arg) = num;
3081         return 0;
3082 }
3083
3084 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3085 {
3086         return param_set_uint_minmax(val, kp,
3087                         RPC_MIN_RESVPORT,
3088                         RPC_MAX_RESVPORT);
3089 }
3090
3091 static struct kernel_param_ops param_ops_portnr = {
3092         .set = param_set_portnr,
3093         .get = param_get_uint,
3094 };
3095
3096 #define param_check_portnr(name, p) \
3097         __param_check(name, p, unsigned int);
3098
3099 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3100 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3101
3102 static int param_set_slot_table_size(const char *val,
3103                                      const struct kernel_param *kp)
3104 {
3105         return param_set_uint_minmax(val, kp,
3106                         RPC_MIN_SLOT_TABLE,
3107                         RPC_MAX_SLOT_TABLE);
3108 }
3109
3110 static struct kernel_param_ops param_ops_slot_table_size = {
3111         .set = param_set_slot_table_size,
3112         .get = param_get_uint,
3113 };
3114
3115 #define param_check_slot_table_size(name, p) \
3116         __param_check(name, p, unsigned int);
3117
3118 static int param_set_max_slot_table_size(const char *val,
3119                                      const struct kernel_param *kp)
3120 {
3121         return param_set_uint_minmax(val, kp,
3122                         RPC_MIN_SLOT_TABLE,
3123                         RPC_MAX_SLOT_TABLE_LIMIT);
3124 }
3125
3126 static struct kernel_param_ops param_ops_max_slot_table_size = {
3127         .set = param_set_max_slot_table_size,
3128         .get = param_get_uint,
3129 };
3130
3131 #define param_check_max_slot_table_size(name, p) \
3132         __param_check(name, p, unsigned int);
3133
3134 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3135                    slot_table_size, 0644);
3136 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3137                    max_slot_table_size, 0644);
3138 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3139                    slot_table_size, 0644);
3140