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/slab.h>
  23 #include <linux/module.h>
  24 #include <linux/capability.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/errno.h>
  27 #include <linux/socket.h>
  28 #include <linux/in.h>
  29 #include <linux/net.h>
  30 #include <linux/mm.h>
  31 #include <linux/udp.h>
  32 #include <linux/tcp.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/sched.h>
  35 #include <linux/sunrpc/svcsock.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/file.h>
  38 #ifdef CONFIG_NFS_V4_1
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #endif
  41
  42 #include <net/sock.h>
  43 #include <net/checksum.h>
  44 #include <net/udp.h>
  45 #include <net/tcp.h>
  46
  47 #include "sunrpc.h"
  48 /*
  49  * xprtsock tunables
  50  */
  51 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  52 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  53
  54 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  55 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  56
  57 #define XS_TCP_LINGER_TO        (15U * HZ)
  58 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  59
  60 /*
  61  * We can register our own files under /proc/sys/sunrpc by
  62  * calling register_sysctl_table() again.  The files in that
  63  * directory become the union of all files registered there.
  64  *
  65  * We simply need to make sure that we don't collide with
  66  * someone else's file names!
  67  */
  68
  69 #ifdef RPC_DEBUG
  70
  71 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  72 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  73 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  74 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  75
  76 static struct ctl_table_header *sunrpc_table_header;
  77
  78 /*
  79  * FIXME: changing the UDP slot table size should also resize the UDP
  80  *        socket buffers for existing UDP transports
  81  */
  82 static ctl_table xs_tunables_table[] = {
  83         {
  84                 .procname       = "udp_slot_table_entries",
  85                 .data           = &xprt_udp_slot_table_entries,
  86                 .maxlen         = sizeof(unsigned int),
  87                 .mode           = 0644,
  88                 .proc_handler   = proc_dointvec_minmax,
  89                 .extra1         = &min_slot_table_size,
  90                 .extra2         = &max_slot_table_size
  91         },
  92         {
  93                 .procname       = "tcp_slot_table_entries",
  94                 .data           = &xprt_tcp_slot_table_entries,
  95                 .maxlen         = sizeof(unsigned int),
  96                 .mode           = 0644,
  97                 .proc_handler   = proc_dointvec_minmax,
  98                 .extra1         = &min_slot_table_size,
  99                 .extra2         = &max_slot_table_size
 100         },
 101         {
 102                 .procname       = "min_resvport",
 103                 .data           = &xprt_min_resvport,
 104                 .maxlen         = sizeof(unsigned int),
 105                 .mode           = 0644,
 106                 .proc_handler   = proc_dointvec_minmax,
 107                 .extra1         = &xprt_min_resvport_limit,
 108                 .extra2         = &xprt_max_resvport_limit
 109         },
 110         {
 111                 .procname       = "max_resvport",
 112                 .data           = &xprt_max_resvport,
 113                 .maxlen         = sizeof(unsigned int),
 114                 .mode           = 0644,
 115                 .proc_handler   = proc_dointvec_minmax,
 116                 .extra1         = &xprt_min_resvport_limit,
 117                 .extra2         = &xprt_max_resvport_limit
 118         },
 119         {
 120                 .procname       = "tcp_fin_timeout",
 121                 .data           = &xs_tcp_fin_timeout,
 122                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 123                 .mode           = 0644,
 124                 .proc_handler   = proc_dointvec_jiffies,
 125         },
 126         { },
 127 };
 128
 129 static ctl_table sunrpc_table[] = {
 130         {
 131                 .procname       = "sunrpc",
 132                 .mode           = 0555,
 133                 .child          = xs_tunables_table
 134         },
 135         { },
 136 };
 137
 138 #endif
 139
 140 /*
 141  * Wait duration for a reply from the RPC portmapper.
 142  */
 143 #define XS_BIND_TO              (60U * HZ)
 144
 145 /*
 146  * Delay if a UDP socket connect error occurs.  This is most likely some
 147  * kind of resource problem on the local host.
 148  */
 149 #define XS_UDP_REEST_TO         (2U * HZ)
 150
 151 /*
 152  * The reestablish timeout allows clients to delay for a bit before attempting
 153  * to reconnect to a server that just dropped our connection.
 154  *
 155  * We implement an exponential backoff when trying to reestablish a TCP
 156  * transport connection with the server.  Some servers like to drop a TCP
 157  * connection when they are overworked, so we start with a short timeout and
 158  * increase over time if the server is down or not responding.
 159  */
 160 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 161 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
 162
 163 /*
 164  * TCP idle timeout; client drops the transport socket if it is idle
 165  * for this long.  Note that we also timeout UDP sockets to prevent
 166  * holding port numbers when there is no RPC traffic.
 167  */
 168 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 169
 170 #ifdef RPC_DEBUG
 171 # undef  RPC_DEBUG_DATA
 172 # define RPCDBG_FACILITY        RPCDBG_TRANS
 173 #endif
 174
 175 #ifdef RPC_DEBUG_DATA
 176 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 177 {
 178         u8 *buf = (u8 *) packet;
 179         int j;
 180
 181         dprintk("RPC:       %s\n", msg);
 182         for (j = 0; j < count && j < 128; j += 4) {
 183                 if (!(j & 31)) {
 184                         if (j)
 185                                 dprintk("\n");
 186                         dprintk("0x%04x ", j);
 187                 }
 188                 dprintk("%02x%02x%02x%02x ",
 189                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 190         }
 191         dprintk("\n");
 192 }
 193 #else
 194 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 195 {
 196         /* NOP */
 197 }
 198 #endif
 199
 200 struct sock_xprt {
 201         struct rpc_xprt         xprt;
 202
 203         /*
 204          * Network layer
 205          */
 206         struct socket *         sock;
 207         struct sock *           inet;
 208
 209         /*
 210          * State of TCP reply receive
 211          */
 212         __be32                  tcp_fraghdr,
 213                                 tcp_xid;
 214
 215         u32                     tcp_offset,
 216                                 tcp_reclen;
 217
 218         unsigned long           tcp_copied,
 219                                 tcp_flags;
 220
 221         /*
 222          * Connection of transports
 223          */
 224         struct delayed_work     connect_worker;
 225         struct sockaddr_storage srcaddr;
 226         unsigned short          srcport;
 227
 228         /*
 229          * UDP socket buffer size parameters
 230          */
 231         size_t                  rcvsize,
 232                                 sndsize;
 233
 234         /*
 235          * Saved socket callback addresses
 236          */
 237         void                    (*old_data_ready)(struct sock *, int);
 238         void                    (*old_state_change)(struct sock *);
 239         void                    (*old_write_space)(struct sock *);
 240         void                    (*old_error_report)(struct sock *);
 241 };
 242
 243 /*
 244  * TCP receive state flags
 245  */
 246 #define TCP_RCV_LAST_FRAG       (1UL << 0)
 247 #define TCP_RCV_COPY_FRAGHDR    (1UL << 1)
 248 #define TCP_RCV_COPY_XID        (1UL << 2)
 249 #define TCP_RCV_COPY_DATA       (1UL << 3)
 250 #define TCP_RCV_READ_CALLDIR    (1UL << 4)
 251 #define TCP_RCV_COPY_CALLDIR    (1UL << 5)
 252
 253 /*
 254  * TCP RPC flags
 255  */
 256 #define TCP_RPC_REPLY           (1UL << 6)
 257
 258 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 259 {
 260         return (struct sockaddr *) &xprt->addr;
 261 }
 262
 263 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 264 {
 265         return (struct sockaddr_in *) &xprt->addr;
 266 }
 267
 268 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 269 {
 270         return (struct sockaddr_in6 *) &xprt->addr;
 271 }
 272
 273 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 274 {
 275         struct sockaddr *sap = xs_addr(xprt);
 276         struct sockaddr_in6 *sin6;
 277         struct sockaddr_in *sin;
 278         char buf[128];
 279
 280         (void)rpc_ntop(sap, buf, sizeof(buf));
 281         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 282
 283         switch (sap->sa_family) {
 284         case AF_INET:
 285                 sin = xs_addr_in(xprt);
 286                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 287                 break;
 288         case AF_INET6:
 289                 sin6 = xs_addr_in6(xprt);
 290                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 291                 break;
 292         default:
 293                 BUG();
 294         }
 295         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 296 }
 297
 298 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 299 {
 300         struct sockaddr *sap = xs_addr(xprt);
 301         char buf[128];
 302
 303         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 304         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 305
 306         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 307         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 308 }
 309
 310 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 311                                      const char *protocol,
 312                                      const char *netid)
 313 {
 314         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 315         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 316         xs_format_common_peer_addresses(xprt);
 317         xs_format_common_peer_ports(xprt);
 318 }
 319
 320 static void xs_update_peer_port(struct rpc_xprt *xprt)
 321 {
 322         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 323         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 324
 325         xs_format_common_peer_ports(xprt);
 326 }
 327
 328 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 329 {
 330         unsigned int i;
 331
 332         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 333                 switch (i) {
 334                 case RPC_DISPLAY_PROTO:
 335                 case RPC_DISPLAY_NETID:
 336                         continue;
 337                 default:
 338                         kfree(xprt->address_strings[i]);
 339                 }
 340 }
 341
 342 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 343
 344 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
 345 {
 346         struct msghdr msg = {
 347                 .msg_name       = addr,
 348                 .msg_namelen    = addrlen,
 349                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
 350         };
 351         struct kvec iov = {
 352                 .iov_base       = vec->iov_base + base,
 353                 .iov_len        = vec->iov_len - base,
 354         };
 355
 356         if (iov.iov_len != 0)
 357                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 358         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 359 }
 360
 361 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
 362 {
 363         struct page **ppage;
 364         unsigned int remainder;
 365         int err, sent = 0;
 366
 367         remainder = xdr->page_len - base;
 368         base += xdr->page_base;
 369         ppage = xdr->pages + (base >> PAGE_SHIFT);
 370         base &= ~PAGE_MASK;
 371         for(;;) {
 372                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
 373                 int flags = XS_SENDMSG_FLAGS;
 374
 375                 remainder -= len;
 376                 if (remainder != 0 || more)
 377                         flags |= MSG_MORE;
 378                 err = sock->ops->sendpage(sock, *ppage, base, len, flags);
 379                 if (remainder == 0 || err != len)
 380                         break;
 381                 sent += err;
 382                 ppage++;
 383                 base = 0;
 384         }
 385         if (sent == 0)
 386                 return err;
 387         if (err > 0)
 388                 sent += err;
 389         return sent;
 390 }
 391
 392 /**
 393  * xs_sendpages - write pages directly to a socket
 394  * @sock: socket to send on
 395  * @addr: UDP only -- address of destination
 396  * @addrlen: UDP only -- length of destination address
 397  * @xdr: buffer containing this request
 398  * @base: starting position in the buffer
 399  *
 400  */
 401 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
 402 {
 403         unsigned int remainder = xdr->len - base;
 404         int err, sent = 0;
 405
 406         if (unlikely(!sock))
 407                 return -ENOTSOCK;
 408
 409         clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
 410         if (base != 0) {
 411                 addr = NULL;
 412                 addrlen = 0;
 413         }
 414
 415         if (base < xdr->head[0].iov_len || addr != NULL) {
 416                 unsigned int len = xdr->head[0].iov_len - base;
 417                 remainder -= len;
 418                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
 419                 if (remainder == 0 || err != len)
 420                         goto out;
 421                 sent += err;
 422                 base = 0;
 423         } else
 424                 base -= xdr->head[0].iov_len;
 425
 426         if (base < xdr->page_len) {
 427                 unsigned int len = xdr->page_len - base;
 428                 remainder -= len;
 429                 err = xs_send_pagedata(sock, xdr, base, remainder != 0);
 430                 if (remainder == 0 || err != len)
 431                         goto out;
 432                 sent += err;
 433                 base = 0;
 434         } else
 435                 base -= xdr->page_len;
 436
 437         if (base >= xdr->tail[0].iov_len)
 438                 return sent;
 439         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
 440 out:
 441         if (sent == 0)
 442                 return err;
 443         if (err > 0)
 444                 sent += err;
 445         return sent;
 446 }
 447
 448 static void xs_nospace_callback(struct rpc_task *task)
 449 {
 450         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 451
 452         transport->inet->sk_write_pending--;
 453         clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 454 }
 455
 456 /**
 457  * xs_nospace - place task on wait queue if transmit was incomplete
 458  * @task: task to put to sleep
 459  *
 460  */
 461 static int xs_nospace(struct rpc_task *task)
 462 {
 463         struct rpc_rqst *req = task->tk_rqstp;
 464         struct rpc_xprt *xprt = req->rq_xprt;
 465         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 466         int ret = 0;
 467
 468         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 469                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 470                         req->rq_slen);
 471
 472         /* Protect against races with write_space */
 473         spin_lock_bh(&xprt->transport_lock);
 474
 475         /* Don't race with disconnect */
 476         if (xprt_connected(xprt)) {
 477                 if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
 478                         ret = -EAGAIN;
 479                         /*
 480                          * Notify TCP that we're limited by the application
 481                          * window size
 482                          */
 483                         set_bit(SOCK_NOSPACE, &transport->sock->flags);
 484                         transport->inet->sk_write_pending++;
 485                         /* ...and wait for more buffer space */
 486                         xprt_wait_for_buffer_space(task, xs_nospace_callback);
 487                 }
 488         } else {
 489                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 490                 ret = -ENOTCONN;
 491         }
 492
 493         spin_unlock_bh(&xprt->transport_lock);
 494         return ret;
 495 }
 496
 497 /**
 498  * xs_udp_send_request - write an RPC request to a UDP socket
 499  * @task: address of RPC task that manages the state of an RPC request
 500  *
 501  * Return values:
 502  *        0:    The request has been sent
 503  *   EAGAIN:    The socket was blocked, please call again later to
 504  *              complete the request
 505  * ENOTCONN:    Caller needs to invoke connect logic then call again
 506  *    other:    Some other error occured, the request was not sent
 507  */
 508 static int xs_udp_send_request(struct rpc_task *task)
 509 {
 510         struct rpc_rqst *req = task->tk_rqstp;
 511         struct rpc_xprt *xprt = req->rq_xprt;
 512         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 513         struct xdr_buf *xdr = &req->rq_snd_buf;
 514         int status;
 515
 516         xs_pktdump("packet data:",
 517                                 req->rq_svec->iov_base,
 518                                 req->rq_svec->iov_len);
 519
 520         if (!xprt_bound(xprt))
 521                 return -ENOTCONN;
 522         status = xs_sendpages(transport->sock,
 523                               xs_addr(xprt),
 524                               xprt->addrlen, xdr,
 525                               req->rq_bytes_sent);
 526
 527         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 528                         xdr->len - req->rq_bytes_sent, status);
 529
 530         if (status >= 0) {
 531                 req->rq_xmit_bytes_sent += status;
 532                 if (status >= req->rq_slen)
 533                         return 0;
 534                 /* Still some bytes left; set up for a retry later. */
 535                 status = -EAGAIN;
 536         }
 537
 538         switch (status) {
 539         case -ENOTSOCK:
 540                 status = -ENOTCONN;
 541                 /* Should we call xs_close() here? */
 542                 break;
 543         case -EAGAIN:
 544                 status = xs_nospace(task);
 545                 break;
 546         default:
 547                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 548                         -status);
 549         case -ENETUNREACH:
 550         case -EPIPE:
 551         case -ECONNREFUSED:
 552                 /* When the server has died, an ICMP port unreachable message
 553                  * prompts ECONNREFUSED. */
 554                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 555         }
 556
 557         return status;
 558 }
 559
 560 /**
 561  * xs_tcp_shutdown - gracefully shut down a TCP socket
 562  * @xprt: transport
 563  *
 564  * Initiates a graceful shutdown of the TCP socket by calling the
 565  * equivalent of shutdown(SHUT_WR);
 566  */
 567 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 568 {
 569         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 570         struct socket *sock = transport->sock;
 571
 572         if (sock != NULL)
 573                 kernel_sock_shutdown(sock, SHUT_WR);
 574 }
 575
 576 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
 577 {
 578         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 579         rpc_fraghdr *base = buf->head[0].iov_base;
 580         *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
 581 }
 582
 583 /**
 584  * xs_tcp_send_request - write an RPC request to a TCP socket
 585  * @task: address of RPC task that manages the state of an RPC request
 586  *
 587  * Return values:
 588  *        0:    The request has been sent
 589  *   EAGAIN:    The socket was blocked, please call again later to
 590  *              complete the request
 591  * ENOTCONN:    Caller needs to invoke connect logic then call again
 592  *    other:    Some other error occured, the request was not sent
 593  *
 594  * XXX: In the case of soft timeouts, should we eventually give up
 595  *      if sendmsg is not able to make progress?
 596  */
 597 static int xs_tcp_send_request(struct rpc_task *task)
 598 {
 599         struct rpc_rqst *req = task->tk_rqstp;
 600         struct rpc_xprt *xprt = req->rq_xprt;
 601         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 602         struct xdr_buf *xdr = &req->rq_snd_buf;
 603         int status;
 604
 605         xs_encode_tcp_record_marker(&req->rq_snd_buf);
 606
 607         xs_pktdump("packet data:",
 608                                 req->rq_svec->iov_base,
 609                                 req->rq_svec->iov_len);
 610
 611         /* Continue transmitting the packet/record. We must be careful
 612          * to cope with writespace callbacks arriving _after_ we have
 613          * called sendmsg(). */
 614         while (1) {
 615                 status = xs_sendpages(transport->sock,
 616                                         NULL, 0, xdr, req->rq_bytes_sent);
 617
 618                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 619                                 xdr->len - req->rq_bytes_sent, status);
 620
 621                 if (unlikely(status < 0))
 622                         break;
 623
 624                 /* If we've sent the entire packet, immediately
 625                  * reset the count of bytes sent. */
 626                 req->rq_bytes_sent += status;
 627                 req->rq_xmit_bytes_sent += status;
 628                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 629                         req->rq_bytes_sent = 0;
 630                         return 0;
 631                 }
 632
 633                 if (status != 0)
 634                         continue;
 635                 status = -EAGAIN;
 636                 break;
 637         }
 638
 639         switch (status) {
 640         case -ENOTSOCK:
 641                 status = -ENOTCONN;
 642                 /* Should we call xs_close() here? */
 643                 break;
 644         case -EAGAIN:
 645                 status = xs_nospace(task);
 646                 break;
 647         default:
 648                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 649                         -status);
 650         case -ECONNRESET:
 651         case -EPIPE:
 652                 xs_tcp_shutdown(xprt);
 653         case -ECONNREFUSED:
 654         case -ENOTCONN:
 655                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 656         }
 657
 658         return status;
 659 }
 660
 661 /**
 662  * xs_tcp_release_xprt - clean up after a tcp transmission
 663  * @xprt: transport
 664  * @task: rpc task
 665  *
 666  * This cleans up if an error causes us to abort the transmission of a request.
 667  * In this case, the socket may need to be reset in order to avoid confusing
 668  * the server.
 669  */
 670 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 671 {
 672         struct rpc_rqst *req;
 673
 674         if (task != xprt->snd_task)
 675                 return;
 676         if (task == NULL)
 677                 goto out_release;
 678         req = task->tk_rqstp;
 679         if (req->rq_bytes_sent == 0)
 680                 goto out_release;
 681         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 682                 goto out_release;
 683         set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
 684 out_release:
 685         xprt_release_xprt(xprt, task);
 686 }
 687
 688 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 689 {
 690         transport->old_data_ready = sk->sk_data_ready;
 691         transport->old_state_change = sk->sk_state_change;
 692         transport->old_write_space = sk->sk_write_space;
 693         transport->old_error_report = sk->sk_error_report;
 694 }
 695
 696 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 697 {
 698         sk->sk_data_ready = transport->old_data_ready;
 699         sk->sk_state_change = transport->old_state_change;
 700         sk->sk_write_space = transport->old_write_space;
 701         sk->sk_error_report = transport->old_error_report;
 702 }
 703
 704 static void xs_reset_transport(struct sock_xprt *transport)
 705 {
 706         struct socket *sock = transport->sock;
 707         struct sock *sk = transport->inet;
 708
 709         if (sk == NULL)
 710                 return;
 711
 712         write_lock_bh(&sk->sk_callback_lock);
 713         transport->inet = NULL;
 714         transport->sock = NULL;
 715
 716         sk->sk_user_data = NULL;
 717
 718         xs_restore_old_callbacks(transport, sk);
 719         write_unlock_bh(&sk->sk_callback_lock);
 720
 721         sk->sk_no_check = 0;
 722
 723         sock_release(sock);
 724 }
 725
 726 /**
 727  * xs_close - close a socket
 728  * @xprt: transport
 729  *
 730  * This is used when all requests are complete; ie, no DRC state remains
 731  * on the server we want to save.
 732  *
 733  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 734  * xs_reset_transport() zeroing the socket from underneath a writer.
 735  */
 736 static void xs_close(struct rpc_xprt *xprt)
 737 {
 738         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 739
 740         dprintk("RPC:       xs_close xprt %p\n", xprt);
 741
 742         xs_reset_transport(transport);
 743         xprt->reestablish_timeout = 0;
 744
 745         smp_mb__before_clear_bit();
 746         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
 747         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 748         clear_bit(XPRT_CLOSING, &xprt->state);
 749         smp_mb__after_clear_bit();
 750         xprt_disconnect_done(xprt);
 751 }
 752
 753 static void xs_tcp_close(struct rpc_xprt *xprt)
 754 {
 755         if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
 756                 xs_close(xprt);
 757         else
 758                 xs_tcp_shutdown(xprt);
 759 }
 760
 761 /**
 762  * xs_destroy - prepare to shutdown a transport
 763  * @xprt: doomed transport
 764  *
 765  */
 766 static void xs_destroy(struct rpc_xprt *xprt)
 767 {
 768         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 769
 770         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 771
 772         cancel_rearming_delayed_work(&transport->connect_worker);
 773
 774         xs_close(xprt);
 775         xs_free_peer_addresses(xprt);
 776         kfree(xprt->slot);
 777         kfree(xprt);
 778         module_put(THIS_MODULE);
 779 }
 780
 781 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 782 {
 783         return (struct rpc_xprt *) sk->sk_user_data;
 784 }
 785
 786 /**
 787  * xs_udp_data_ready - "data ready" callback for UDP sockets
 788  * @sk: socket with data to read
 789  * @len: how much data to read
 790  *
 791  */
 792 static void xs_udp_data_ready(struct sock *sk, int len)
 793 {
 794         struct rpc_task *task;
 795         struct rpc_xprt *xprt;
 796         struct rpc_rqst *rovr;
 797         struct sk_buff *skb;
 798         int err, repsize, copied;
 799         u32 _xid;
 800         __be32 *xp;
 801
 802         read_lock(&sk->sk_callback_lock);
 803         dprintk("RPC:       xs_udp_data_ready...\n");
 804         if (!(xprt = xprt_from_sock(sk)))
 805                 goto out;
 806
 807         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
 808                 goto out;
 809
 810         if (xprt->shutdown)
 811                 goto dropit;
 812
 813         repsize = skb->len - sizeof(struct udphdr);
 814         if (repsize < 4) {
 815                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
 816                 goto dropit;
 817         }
 818
 819         /* Copy the XID from the skb... */
 820         xp = skb_header_pointer(skb, sizeof(struct udphdr),
 821                                 sizeof(_xid), &_xid);
 822         if (xp == NULL)
 823                 goto dropit;
 824
 825         /* Look up and lock the request corresponding to the given XID */
 826         spin_lock(&xprt->transport_lock);
 827         rovr = xprt_lookup_rqst(xprt, *xp);
 828         if (!rovr)
 829                 goto out_unlock;
 830         task = rovr->rq_task;
 831
 832         if ((copied = rovr->rq_private_buf.buflen) > repsize)
 833                 copied = repsize;
 834
 835         /* Suck it into the iovec, verify checksum if not done by hw. */
 836         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 837                 UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
 838                 goto out_unlock;
 839         }
 840
 841         UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
 842
 843         /* Something worked... */
 844         dst_confirm(skb_dst(skb));
 845
 846         xprt_adjust_cwnd(task, copied);
 847         xprt_complete_rqst(task, copied);
 848
 849  out_unlock:
 850         spin_unlock(&xprt->transport_lock);
 851  dropit:
 852         skb_free_datagram(sk, skb);
 853  out:
 854         read_unlock(&sk->sk_callback_lock);
 855 }
 856
 857 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
 858 {
 859         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 860         size_t len, used;
 861         char *p;
 862
 863         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
 864         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
 865         used = xdr_skb_read_bits(desc, p, len);
 866         transport->tcp_offset += used;
 867         if (used != len)
 868                 return;
 869
 870         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
 871         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
 872                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
 873         else
 874                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
 875         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
 876
 877         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
 878         transport->tcp_offset = 0;
 879
 880         /* Sanity check of the record length */
 881         if (unlikely(transport->tcp_reclen < 8)) {
 882                 dprintk("RPC:       invalid TCP record fragment length\n");
 883                 xprt_force_disconnect(xprt);
 884                 return;
 885         }
 886         dprintk("RPC:       reading TCP record fragment of length %d\n",
 887                         transport->tcp_reclen);
 888 }
 889
 890 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
 891 {
 892         if (transport->tcp_offset == transport->tcp_reclen) {
 893                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
 894                 transport->tcp_offset = 0;
 895                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
 896                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 897                         transport->tcp_flags |= TCP_RCV_COPY_XID;
 898                         transport->tcp_copied = 0;
 899                 }
 900         }
 901 }
 902
 903 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
 904 {
 905         size_t len, used;
 906         char *p;
 907
 908         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
 909         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
 910         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
 911         used = xdr_skb_read_bits(desc, p, len);
 912         transport->tcp_offset += used;
 913         if (used != len)
 914                 return;
 915         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
 916         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
 917         transport->tcp_copied = 4;
 918         dprintk("RPC:       reading %s XID %08x\n",
 919                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
 920                                                               : "request with",
 921                         ntohl(transport->tcp_xid));
 922         xs_tcp_check_fraghdr(transport);
 923 }
 924
 925 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
 926                                        struct xdr_skb_reader *desc)
 927 {
 928         size_t len, used;
 929         u32 offset;
 930         __be32  calldir;
 931
 932         /*
 933          * We want transport->tcp_offset to be 8 at the end of this routine
 934          * (4 bytes for the xid and 4 bytes for the call/reply flag).
 935          * When this function is called for the first time,
 936          * transport->tcp_offset is 4 (after having already read the xid).
 937          */
 938         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
 939         len = sizeof(calldir) - offset;
 940         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
 941         used = xdr_skb_read_bits(desc, &calldir, len);
 942         transport->tcp_offset += used;
 943         if (used != len)
 944                 return;
 945         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
 946         transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
 947         transport->tcp_flags |= TCP_RCV_COPY_DATA;
 948         /*
 949          * We don't yet have the XDR buffer, so we will write the calldir
 950          * out after we get the buffer from the 'struct rpc_rqst'
 951          */
 952         if (ntohl(calldir) == RPC_REPLY)
 953                 transport->tcp_flags |= TCP_RPC_REPLY;
 954         else
 955                 transport->tcp_flags &= ~TCP_RPC_REPLY;
 956         dprintk("RPC:       reading %s CALL/REPLY flag %08x\n",
 957                         (transport->tcp_flags & TCP_RPC_REPLY) ?
 958                                 "reply for" : "request with", calldir);
 959         xs_tcp_check_fraghdr(transport);
 960 }
 961
 962 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
 963                                      struct xdr_skb_reader *desc,
 964                                      struct rpc_rqst *req)
 965 {
 966         struct sock_xprt *transport =
 967                                 container_of(xprt, struct sock_xprt, xprt);
 968         struct xdr_buf *rcvbuf;
 969         size_t len;
 970         ssize_t r;
 971
 972         rcvbuf = &req->rq_private_buf;
 973
 974         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
 975                 /*
 976                  * Save the RPC direction in the XDR buffer
 977                  */
 978                 __be32  calldir = transport->tcp_flags & TCP_RPC_REPLY ?
 979                                         htonl(RPC_REPLY) : 0;
 980
 981                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
 982                         &calldir, sizeof(calldir));
 983                 transport->tcp_copied += sizeof(calldir);
 984                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
 985         }
 986
 987         len = desc->count;
 988         if (len > transport->tcp_reclen - transport->tcp_offset) {
 989                 struct xdr_skb_reader my_desc;
 990
 991                 len = transport->tcp_reclen - transport->tcp_offset;
 992                 memcpy(&my_desc, desc, sizeof(my_desc));
 993                 my_desc.count = len;
 994                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
 995                                           &my_desc, xdr_skb_read_bits);
 996                 desc->count -= r;
 997                 desc->offset += r;
 998         } else
 999                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1000                                           desc, xdr_skb_read_bits);
1001
1002         if (r > 0) {
1003                 transport->tcp_copied += r;
1004                 transport->tcp_offset += r;
1005         }
1006         if (r != len) {
1007                 /* Error when copying to the receive buffer,
1008                  * usually because we weren't able to allocate
1009                  * additional buffer pages. All we can do now
1010                  * is turn off TCP_RCV_COPY_DATA, so the request
1011                  * will not receive any additional updates,
1012                  * and time out.
1013                  * Any remaining data from this record will
1014                  * be discarded.
1015                  */
1016                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1017                 dprintk("RPC:       XID %08x truncated request\n",
1018                                 ntohl(transport->tcp_xid));
1019                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1020                                 "tcp_offset = %u, tcp_reclen = %u\n",
1021                                 xprt, transport->tcp_copied,
1022                                 transport->tcp_offset, transport->tcp_reclen);
1023                 return;
1024         }
1025
1026         dprintk("RPC:       XID %08x read %Zd bytes\n",
1027                         ntohl(transport->tcp_xid), r);
1028         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1029                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1030                         transport->tcp_offset, transport->tcp_reclen);
1031
1032         if (transport->tcp_copied == req->rq_private_buf.buflen)
1033                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1034         else if (transport->tcp_offset == transport->tcp_reclen) {
1035                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1036                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1037         }
1038 }
1039
1040 /*
1041  * Finds the request corresponding to the RPC xid and invokes the common
1042  * tcp read code to read the data.
1043  */
1044 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1045                                     struct xdr_skb_reader *desc)
1046 {
1047         struct sock_xprt *transport =
1048                                 container_of(xprt, struct sock_xprt, xprt);
1049         struct rpc_rqst *req;
1050
1051         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1052
1053         /* Find and lock the request corresponding to this xid */
1054         spin_lock(&xprt->transport_lock);
1055         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1056         if (!req) {
1057                 dprintk("RPC:       XID %08x request not found!\n",
1058                                 ntohl(transport->tcp_xid));
1059                 spin_unlock(&xprt->transport_lock);
1060                 return -1;
1061         }
1062
1063         xs_tcp_read_common(xprt, desc, req);
1064
1065         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1066                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1067
1068         spin_unlock(&xprt->transport_lock);
1069         return 0;
1070 }
1071
1072 #if defined(CONFIG_NFS_V4_1)
1073 /*
1074  * Obtains an rpc_rqst previously allocated and invokes the common
1075  * tcp read code to read the data.  The result is placed in the callback
1076  * queue.
1077  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1078  * connection and return -1.
1079  */
1080 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1081                                        struct xdr_skb_reader *desc)
1082 {
1083         struct sock_xprt *transport =
1084                                 container_of(xprt, struct sock_xprt, xprt);
1085         struct rpc_rqst *req;
1086
1087         req = xprt_alloc_bc_request(xprt);
1088         if (req == NULL) {
1089                 printk(KERN_WARNING "Callback slot table overflowed\n");
1090                 xprt_force_disconnect(xprt);
1091                 return -1;
1092         }
1093
1094         req->rq_xid = transport->tcp_xid;
1095         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1096         xs_tcp_read_common(xprt, desc, req);
1097
1098         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1099                 struct svc_serv *bc_serv = xprt->bc_serv;
1100
1101                 /*
1102                  * Add callback request to callback list.  The callback
1103                  * service sleeps on the sv_cb_waitq waiting for new
1104                  * requests.  Wake it up after adding enqueing the
1105                  * request.
1106                  */
1107                 dprintk("RPC:       add callback request to list\n");
1108                 spin_lock(&bc_serv->sv_cb_lock);
1109                 list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1110                 spin_unlock(&bc_serv->sv_cb_lock);
1111                 wake_up(&bc_serv->sv_cb_waitq);
1112         }
1113
1114         req->rq_private_buf.len = transport->tcp_copied;
1115
1116         return 0;
1117 }
1118
1119 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1120                                         struct xdr_skb_reader *desc)
1121 {
1122         struct sock_xprt *transport =
1123                                 container_of(xprt, struct sock_xprt, xprt);
1124
1125         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1126                 xs_tcp_read_reply(xprt, desc) :
1127                 xs_tcp_read_callback(xprt, desc);
1128 }
1129 #else
1130 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1131                                         struct xdr_skb_reader *desc)
1132 {
1133         return xs_tcp_read_reply(xprt, desc);
1134 }
1135 #endif /* CONFIG_NFS_V4_1 */
1136
1137 /*
1138  * Read data off the transport.  This can be either an RPC_CALL or an
1139  * RPC_REPLY.  Relay the processing to helper functions.
1140  */
1141 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1142                                     struct xdr_skb_reader *desc)
1143 {
1144         struct sock_xprt *transport =
1145                                 container_of(xprt, struct sock_xprt, xprt);
1146
1147         if (_xs_tcp_read_data(xprt, desc) == 0)
1148                 xs_tcp_check_fraghdr(transport);
1149         else {
1150                 /*
1151                  * The transport_lock protects the request handling.
1152                  * There's no need to hold it to update the tcp_flags.
1153                  */
1154                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1155         }
1156 }
1157
1158 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1159 {
1160         size_t len;
1161
1162         len = transport->tcp_reclen - transport->tcp_offset;
1163         if (len > desc->count)
1164                 len = desc->count;
1165         desc->count -= len;
1166         desc->offset += len;
1167         transport->tcp_offset += len;
1168         dprintk("RPC:       discarded %Zu bytes\n", len);
1169         xs_tcp_check_fraghdr(transport);
1170 }
1171
1172 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1173 {
1174         struct rpc_xprt *xprt = rd_desc->arg.data;
1175         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1176         struct xdr_skb_reader desc = {
1177                 .skb    = skb,
1178                 .offset = offset,
1179                 .count  = len,
1180         };
1181
1182         dprintk("RPC:       xs_tcp_data_recv started\n");
1183         do {
1184                 /* Read in a new fragment marker if necessary */
1185                 /* Can we ever really expect to get completely empty fragments? */
1186                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1187                         xs_tcp_read_fraghdr(xprt, &desc);
1188                         continue;
1189                 }
1190                 /* Read in the xid if necessary */
1191                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1192                         xs_tcp_read_xid(transport, &desc);
1193                         continue;
1194                 }
1195                 /* Read in the call/reply flag */
1196                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1197                         xs_tcp_read_calldir(transport, &desc);
1198                         continue;
1199                 }
1200                 /* Read in the request data */
1201                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1202                         xs_tcp_read_data(xprt, &desc);
1203                         continue;
1204                 }
1205                 /* Skip over any trailing bytes on short reads */
1206                 xs_tcp_read_discard(transport, &desc);
1207         } while (desc.count);
1208         dprintk("RPC:       xs_tcp_data_recv done\n");
1209         return len - desc.count;
1210 }
1211
1212 /**
1213  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1214  * @sk: socket with data to read
1215  * @bytes: how much data to read
1216  *
1217  */
1218 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1219 {
1220         struct rpc_xprt *xprt;
1221         read_descriptor_t rd_desc;
1222         int read;
1223
1224         dprintk("RPC:       xs_tcp_data_ready...\n");
1225
1226         read_lock(&sk->sk_callback_lock);
1227         if (!(xprt = xprt_from_sock(sk)))
1228                 goto out;
1229         if (xprt->shutdown)
1230                 goto out;
1231
1232         /* Any data means we had a useful conversation, so
1233          * the we don't need to delay the next reconnect
1234          */
1235         if (xprt->reestablish_timeout)
1236                 xprt->reestablish_timeout = 0;
1237
1238         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1239         rd_desc.arg.data = xprt;
1240         do {
1241                 rd_desc.count = 65536;
1242                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1243         } while (read > 0);
1244 out:
1245         read_unlock(&sk->sk_callback_lock);
1246 }
1247
1248 /*
1249  * Do the equivalent of linger/linger2 handling for dealing with
1250  * broken servers that don't close the socket in a timely
1251  * fashion
1252  */
1253 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1254                 unsigned long timeout)
1255 {
1256         struct sock_xprt *transport;
1257
1258         if (xprt_test_and_set_connecting(xprt))
1259                 return;
1260         set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1261         transport = container_of(xprt, struct sock_xprt, xprt);
1262         queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1263                            timeout);
1264 }
1265
1266 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1267 {
1268         struct sock_xprt *transport;
1269
1270         transport = container_of(xprt, struct sock_xprt, xprt);
1271
1272         if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1273             !cancel_delayed_work(&transport->connect_worker))
1274                 return;
1275         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1276         xprt_clear_connecting(xprt);
1277 }
1278
1279 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1280 {
1281         smp_mb__before_clear_bit();
1282         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1283         clear_bit(XPRT_CLOSING, &xprt->state);
1284         smp_mb__after_clear_bit();
1285         /* Mark transport as closed and wake up all pending tasks */
1286         xprt_disconnect_done(xprt);
1287 }
1288
1289 /**
1290  * xs_tcp_state_change - callback to handle TCP socket state changes
1291  * @sk: socket whose state has changed
1292  *
1293  */
1294 static void xs_tcp_state_change(struct sock *sk)
1295 {
1296         struct rpc_xprt *xprt;
1297
1298         read_lock(&sk->sk_callback_lock);
1299         if (!(xprt = xprt_from_sock(sk)))
1300                 goto out;
1301         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1302         dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1303                         sk->sk_state, xprt_connected(xprt),
1304                         sock_flag(sk, SOCK_DEAD),
1305                         sock_flag(sk, SOCK_ZAPPED));
1306
1307         switch (sk->sk_state) {
1308         case TCP_ESTABLISHED:
1309                 spin_lock_bh(&xprt->transport_lock);
1310                 if (!xprt_test_and_set_connected(xprt)) {
1311                         struct sock_xprt *transport = container_of(xprt,
1312                                         struct sock_xprt, xprt);
1313
1314                         /* Reset TCP record info */
1315                         transport->tcp_offset = 0;
1316                         transport->tcp_reclen = 0;
1317                         transport->tcp_copied = 0;
1318                         transport->tcp_flags =
1319                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1320
1321                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1322                 }
1323                 spin_unlock_bh(&xprt->transport_lock);
1324                 break;
1325         case TCP_FIN_WAIT1:
1326                 /* The client initiated a shutdown of the socket */
1327                 xprt->connect_cookie++;
1328                 xprt->reestablish_timeout = 0;
1329                 set_bit(XPRT_CLOSING, &xprt->state);
1330                 smp_mb__before_clear_bit();
1331                 clear_bit(XPRT_CONNECTED, &xprt->state);
1332                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1333                 smp_mb__after_clear_bit();
1334                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1335                 break;
1336         case TCP_CLOSE_WAIT:
1337                 /* The server initiated a shutdown of the socket */
1338                 xprt_force_disconnect(xprt);
1339         case TCP_SYN_SENT:
1340                 xprt->connect_cookie++;
1341         case TCP_CLOSING:
1342                 /*
1343                  * If the server closed down the connection, make sure that
1344                  * we back off before reconnecting
1345                  */
1346                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1347                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1348                 break;
1349         case TCP_LAST_ACK:
1350                 set_bit(XPRT_CLOSING, &xprt->state);
1351                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1352                 smp_mb__before_clear_bit();
1353                 clear_bit(XPRT_CONNECTED, &xprt->state);
1354                 smp_mb__after_clear_bit();
1355                 break;
1356         case TCP_CLOSE:
1357                 xs_tcp_cancel_linger_timeout(xprt);
1358                 xs_sock_mark_closed(xprt);
1359         }
1360  out:
1361         read_unlock(&sk->sk_callback_lock);
1362 }
1363
1364 /**
1365  * xs_error_report - callback mainly for catching socket errors
1366  * @sk: socket
1367  */
1368 static void xs_error_report(struct sock *sk)
1369 {
1370         struct rpc_xprt *xprt;
1371
1372         read_lock(&sk->sk_callback_lock);
1373         if (!(xprt = xprt_from_sock(sk)))
1374                 goto out;
1375         dprintk("RPC:       %s client %p...\n"
1376                         "RPC:       error %d\n",
1377                         __func__, xprt, sk->sk_err);
1378         xprt_wake_pending_tasks(xprt, -EAGAIN);
1379 out:
1380         read_unlock(&sk->sk_callback_lock);
1381 }
1382
1383 static void xs_write_space(struct sock *sk)
1384 {
1385         struct socket *sock;
1386         struct rpc_xprt *xprt;
1387
1388         if (unlikely(!(sock = sk->sk_socket)))
1389                 return;
1390         clear_bit(SOCK_NOSPACE, &sock->flags);
1391
1392         if (unlikely(!(xprt = xprt_from_sock(sk))))
1393                 return;
1394         if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1395                 return;
1396
1397         xprt_write_space(xprt);
1398 }
1399
1400 /**
1401  * xs_udp_write_space - callback invoked when socket buffer space
1402  *                             becomes available
1403  * @sk: socket whose state has changed
1404  *
1405  * Called when more output buffer space is available for this socket.
1406  * We try not to wake our writers until they can make "significant"
1407  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1408  * with a bunch of small requests.
1409  */
1410 static void xs_udp_write_space(struct sock *sk)
1411 {
1412         read_lock(&sk->sk_callback_lock);
1413
1414         /* from net/core/sock.c:sock_def_write_space */
1415         if (sock_writeable(sk))
1416                 xs_write_space(sk);
1417
1418         read_unlock(&sk->sk_callback_lock);
1419 }
1420
1421 /**
1422  * xs_tcp_write_space - callback invoked when socket buffer space
1423  *                             becomes available
1424  * @sk: socket whose state has changed
1425  *
1426  * Called when more output buffer space is available for this socket.
1427  * We try not to wake our writers until they can make "significant"
1428  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1429  * with a bunch of small requests.
1430  */
1431 static void xs_tcp_write_space(struct sock *sk)
1432 {
1433         read_lock(&sk->sk_callback_lock);
1434
1435         /* from net/core/stream.c:sk_stream_write_space */
1436         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
1437                 xs_write_space(sk);
1438
1439         read_unlock(&sk->sk_callback_lock);
1440 }
1441
1442 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1443 {
1444         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1445         struct sock *sk = transport->inet;
1446
1447         if (transport->rcvsize) {
1448                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1449                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1450         }
1451         if (transport->sndsize) {
1452                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1453                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1454                 sk->sk_write_space(sk);
1455         }
1456 }
1457
1458 /**
1459  * xs_udp_set_buffer_size - set send and receive limits
1460  * @xprt: generic transport
1461  * @sndsize: requested size of send buffer, in bytes
1462  * @rcvsize: requested size of receive buffer, in bytes
1463  *
1464  * Set socket send and receive buffer size limits.
1465  */
1466 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1467 {
1468         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1469
1470         transport->sndsize = 0;
1471         if (sndsize)
1472                 transport->sndsize = sndsize + 1024;
1473         transport->rcvsize = 0;
1474         if (rcvsize)
1475                 transport->rcvsize = rcvsize + 1024;
1476
1477         xs_udp_do_set_buffer_size(xprt);
1478 }
1479
1480 /**
1481  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1482  * @task: task that timed out
1483  *
1484  * Adjust the congestion window after a retransmit timeout has occurred.
1485  */
1486 static void xs_udp_timer(struct rpc_task *task)
1487 {
1488         xprt_adjust_cwnd(task, -ETIMEDOUT);
1489 }
1490
1491 static unsigned short xs_get_random_port(void)
1492 {
1493         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1494         unsigned short rand = (unsigned short) net_random() % range;
1495         return rand + xprt_min_resvport;
1496 }
1497
1498 /**
1499  * xs_set_port - reset the port number in the remote endpoint address
1500  * @xprt: generic transport
1501  * @port: new port number
1502  *
1503  */
1504 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1505 {
1506         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1507
1508         rpc_set_port(xs_addr(xprt), port);
1509         xs_update_peer_port(xprt);
1510 }
1511
1512 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1513 {
1514         unsigned short port = transport->srcport;
1515
1516         if (port == 0 && transport->xprt.resvport)
1517                 port = xs_get_random_port();
1518         return port;
1519 }
1520
1521 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1522 {
1523         if (transport->srcport != 0)
1524                 transport->srcport = 0;
1525         if (!transport->xprt.resvport)
1526                 return 0;
1527         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1528                 return xprt_max_resvport;
1529         return --port;
1530 }
1531
1532 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1533 {
1534         struct sockaddr_in myaddr = {
1535                 .sin_family = AF_INET,
1536         };
1537         struct sockaddr_in *sa;
1538         int err, nloop = 0;
1539         unsigned short port = xs_get_srcport(transport, sock);
1540         unsigned short last;
1541
1542         sa = (struct sockaddr_in *)&transport->srcaddr;
1543         myaddr.sin_addr = sa->sin_addr;
1544         do {
1545                 myaddr.sin_port = htons(port);
1546                 err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1547                                                 sizeof(myaddr));
1548                 if (port == 0)
1549                         break;
1550                 if (err == 0) {
1551                         transport->srcport = port;
1552                         break;
1553                 }
1554                 last = port;
1555                 port = xs_next_srcport(transport, sock, port);
1556                 if (port > last)
1557                         nloop++;
1558         } while (err == -EADDRINUSE && nloop != 2);
1559         dprintk("RPC:       %s %pI4:%u: %s (%d)\n",
1560                         __func__, &myaddr.sin_addr,
1561                         port, err ? "failed" : "ok", err);
1562         return err;
1563 }
1564
1565 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1566 {
1567         struct sockaddr_in6 myaddr = {
1568                 .sin6_family = AF_INET6,
1569         };
1570         struct sockaddr_in6 *sa;
1571         int err, nloop = 0;
1572         unsigned short port = xs_get_srcport(transport, sock);
1573         unsigned short last;
1574
1575         sa = (struct sockaddr_in6 *)&transport->srcaddr;
1576         myaddr.sin6_addr = sa->sin6_addr;
1577         do {
1578                 myaddr.sin6_port = htons(port);
1579                 err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1580                                                 sizeof(myaddr));
1581                 if (port == 0)
1582                         break;
1583                 if (err == 0) {
1584                         transport->srcport = port;
1585                         break;
1586                 }
1587                 last = port;
1588                 port = xs_next_srcport(transport, sock, port);
1589                 if (port > last)
1590                         nloop++;
1591         } while (err == -EADDRINUSE && nloop != 2);
1592         dprintk("RPC:       xs_bind6 %pI6:%u: %s (%d)\n",
1593                 &myaddr.sin6_addr, port, err ? "failed" : "ok", err);
1594         return err;
1595 }
1596
1597 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1598 static struct lock_class_key xs_key[2];
1599 static struct lock_class_key xs_slock_key[2];
1600
1601 static inline void xs_reclassify_socket4(struct socket *sock)
1602 {
1603         struct sock *sk = sock->sk;
1604
1605         BUG_ON(sock_owned_by_user(sk));
1606         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1607                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1608 }
1609
1610 static inline void xs_reclassify_socket6(struct socket *sock)
1611 {
1612         struct sock *sk = sock->sk;
1613
1614         BUG_ON(sock_owned_by_user(sk));
1615         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1616                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1617 }
1618 #else
1619 static inline void xs_reclassify_socket4(struct socket *sock)
1620 {
1621 }
1622
1623 static inline void xs_reclassify_socket6(struct socket *sock)
1624 {
1625 }
1626 #endif
1627
1628 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1629 {
1630         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1631
1632         if (!transport->inet) {
1633                 struct sock *sk = sock->sk;
1634
1635                 write_lock_bh(&sk->sk_callback_lock);
1636
1637                 xs_save_old_callbacks(transport, sk);
1638
1639                 sk->sk_user_data = xprt;
1640                 sk->sk_data_ready = xs_udp_data_ready;
1641                 sk->sk_write_space = xs_udp_write_space;
1642                 sk->sk_error_report = xs_error_report;
1643                 sk->sk_no_check = UDP_CSUM_NORCV;
1644                 sk->sk_allocation = GFP_ATOMIC;
1645
1646                 xprt_set_connected(xprt);
1647
1648                 /* Reset to new socket */
1649                 transport->sock = sock;
1650                 transport->inet = sk;
1651
1652                 write_unlock_bh(&sk->sk_callback_lock);
1653         }
1654         xs_udp_do_set_buffer_size(xprt);
1655 }
1656
1657 /**
1658  * xs_udp_connect_worker4 - set up a UDP socket
1659  * @work: RPC transport to connect
1660  *
1661  * Invoked by a work queue tasklet.
1662  */
1663 static void xs_udp_connect_worker4(struct work_struct *work)
1664 {
1665         struct sock_xprt *transport =
1666                 container_of(work, struct sock_xprt, connect_worker.work);
1667         struct rpc_xprt *xprt = &transport->xprt;
1668         struct socket *sock = transport->sock;
1669         int err, status = -EIO;
1670
1671         if (xprt->shutdown)
1672                 goto out;
1673
1674         /* Start by resetting any existing state */
1675         xs_reset_transport(transport);
1676
1677         err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
1678         if (err < 0) {
1679                 dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1680                 goto out;
1681         }
1682         xs_reclassify_socket4(sock);
1683
1684         if (xs_bind4(transport, sock)) {
1685                 sock_release(sock);
1686                 goto out;
1687         }
1688
1689         dprintk("RPC:       worker connecting xprt %p via %s to "
1690                                 "%s (port %s)\n", xprt,
1691                         xprt->address_strings[RPC_DISPLAY_PROTO],
1692                         xprt->address_strings[RPC_DISPLAY_ADDR],
1693                         xprt->address_strings[RPC_DISPLAY_PORT]);
1694
1695         xs_udp_finish_connecting(xprt, sock);
1696         status = 0;
1697 out:
1698         xprt_clear_connecting(xprt);
1699         xprt_wake_pending_tasks(xprt, status);
1700 }
1701
1702 /**
1703  * xs_udp_connect_worker6 - set up a UDP socket
1704  * @work: RPC transport to connect
1705  *
1706  * Invoked by a work queue tasklet.
1707  */
1708 static void xs_udp_connect_worker6(struct work_struct *work)
1709 {
1710         struct sock_xprt *transport =
1711                 container_of(work, struct sock_xprt, connect_worker.work);
1712         struct rpc_xprt *xprt = &transport->xprt;
1713         struct socket *sock = transport->sock;
1714         int err, status = -EIO;
1715
1716         if (xprt->shutdown)
1717                 goto out;
1718
1719         /* Start by resetting any existing state */
1720         xs_reset_transport(transport);
1721
1722         err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock);
1723         if (err < 0) {
1724                 dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1725                 goto out;
1726         }
1727         xs_reclassify_socket6(sock);
1728
1729         if (xs_bind6(transport, sock) < 0) {
1730                 sock_release(sock);
1731                 goto out;
1732         }
1733
1734         dprintk("RPC:       worker connecting xprt %p via %s to "
1735                                 "%s (port %s)\n", xprt,
1736                         xprt->address_strings[RPC_DISPLAY_PROTO],
1737                         xprt->address_strings[RPC_DISPLAY_ADDR],
1738                         xprt->address_strings[RPC_DISPLAY_PORT]);
1739
1740         xs_udp_finish_connecting(xprt, sock);
1741         status = 0;
1742 out:
1743         xprt_clear_connecting(xprt);
1744         xprt_wake_pending_tasks(xprt, status);
1745 }
1746
1747 /*
1748  * We need to preserve the port number so the reply cache on the server can
1749  * find our cached RPC replies when we get around to reconnecting.
1750  */
1751 static void xs_abort_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
1752 {
1753         int result;
1754         struct sockaddr any;
1755
1756         dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1757
1758         /*
1759          * Disconnect the transport socket by doing a connect operation
1760          * with AF_UNSPEC.  This should return immediately...
1761          */
1762         memset(&any, 0, sizeof(any));
1763         any.sa_family = AF_UNSPEC;
1764         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1765         if (!result)
1766                 xs_sock_mark_closed(xprt);
1767         else
1768                 dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1769                                 result);
1770 }
1771
1772 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
1773 {
1774         unsigned int state = transport->inet->sk_state;
1775
1776         if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED)
1777                 return;
1778         if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT))
1779                 return;
1780         xs_abort_connection(xprt, transport);
1781 }
1782
1783 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1784 {
1785         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1786
1787         if (!transport->inet) {
1788                 struct sock *sk = sock->sk;
1789
1790                 write_lock_bh(&sk->sk_callback_lock);
1791
1792                 xs_save_old_callbacks(transport, sk);
1793
1794                 sk->sk_user_data = xprt;
1795                 sk->sk_data_ready = xs_tcp_data_ready;
1796                 sk->sk_state_change = xs_tcp_state_change;
1797                 sk->sk_write_space = xs_tcp_write_space;
1798                 sk->sk_error_report = xs_error_report;
1799                 sk->sk_allocation = GFP_ATOMIC;
1800
1801                 /* socket options */
1802                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1803                 sock_reset_flag(sk, SOCK_LINGER);
1804                 tcp_sk(sk)->linger2 = 0;
1805                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1806
1807                 xprt_clear_connected(xprt);
1808
1809                 /* Reset to new socket */
1810                 transport->sock = sock;
1811                 transport->inet = sk;
1812
1813                 write_unlock_bh(&sk->sk_callback_lock);
1814         }
1815
1816         if (!xprt_bound(xprt))
1817                 return -ENOTCONN;
1818
1819         /* Tell the socket layer to start connecting... */
1820         xprt->stat.connect_count++;
1821         xprt->stat.connect_start = jiffies;
1822         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1823 }
1824
1825 /**
1826  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
1827  * @xprt: RPC transport to connect
1828  * @transport: socket transport to connect
1829  * @create_sock: function to create a socket of the correct type
1830  *
1831  * Invoked by a work queue tasklet.
1832  */
1833 static void xs_tcp_setup_socket(struct rpc_xprt *xprt,
1834                 struct sock_xprt *transport,
1835                 struct socket *(*create_sock)(struct rpc_xprt *,
1836                         struct sock_xprt *))
1837 {
1838         struct socket *sock = transport->sock;
1839         int status = -EIO;
1840
1841         if (xprt->shutdown)
1842                 goto out;
1843
1844         if (!sock) {
1845                 clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1846                 sock = create_sock(xprt, transport);
1847                 if (IS_ERR(sock)) {
1848                         status = PTR_ERR(sock);
1849                         goto out;
1850                 }
1851         } else {
1852                 int abort_and_exit;
1853
1854                 abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
1855                                 &xprt->state);
1856                 /* "close" the socket, preserving the local port */
1857                 xs_tcp_reuse_connection(xprt, transport);
1858
1859                 if (abort_and_exit)
1860                         goto out_eagain;
1861         }
1862
1863         dprintk("RPC:       worker connecting xprt %p via %s to "
1864                                 "%s (port %s)\n", xprt,
1865                         xprt->address_strings[RPC_DISPLAY_PROTO],
1866                         xprt->address_strings[RPC_DISPLAY_ADDR],
1867                         xprt->address_strings[RPC_DISPLAY_PORT]);
1868
1869         status = xs_tcp_finish_connecting(xprt, sock);
1870         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1871                         xprt, -status, xprt_connected(xprt),
1872                         sock->sk->sk_state);
1873         switch (status) {
1874         default:
1875                 printk("%s: connect returned unhandled error %d\n",
1876                         __func__, status);
1877         case -EADDRNOTAVAIL:
1878                 /* We're probably in TIME_WAIT. Get rid of existing socket,
1879                  * and retry
1880                  */
1881                 set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1882                 xprt_force_disconnect(xprt);
1883                 break;
1884         case -ECONNREFUSED:
1885         case -ECONNRESET:
1886         case -ENETUNREACH:
1887                 /* retry with existing socket, after a delay */
1888         case 0:
1889         case -EINPROGRESS:
1890         case -EALREADY:
1891                 xprt_clear_connecting(xprt);
1892                 return;
1893         case -EINVAL:
1894                 /* Happens, for instance, if the user specified a link
1895                  * local IPv6 address without a scope-id.
1896                  */
1897                 goto out;
1898         }
1899 out_eagain:
1900         status = -EAGAIN;
1901 out:
1902         xprt_clear_connecting(xprt);
1903         xprt_wake_pending_tasks(xprt, status);
1904 }
1905
1906 static struct socket *xs_create_tcp_sock4(struct rpc_xprt *xprt,
1907                 struct sock_xprt *transport)
1908 {
1909         struct socket *sock;
1910         int err;
1911
1912         /* start from scratch */
1913         err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1914         if (err < 0) {
1915                 dprintk("RPC:       can't create TCP transport socket (%d).\n",
1916                                 -err);
1917                 goto out_err;
1918         }
1919         xs_reclassify_socket4(sock);
1920
1921         if (xs_bind4(transport, sock) < 0) {
1922                 sock_release(sock);
1923                 goto out_err;
1924         }
1925         return sock;
1926 out_err:
1927         return ERR_PTR(-EIO);
1928 }
1929
1930 /**
1931  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1932  * @work: RPC transport to connect
1933  *
1934  * Invoked by a work queue tasklet.
1935  */
1936 static void xs_tcp_connect_worker4(struct work_struct *work)
1937 {
1938         struct sock_xprt *transport =
1939                 container_of(work, struct sock_xprt, connect_worker.work);
1940         struct rpc_xprt *xprt = &transport->xprt;
1941
1942         xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock4);
1943 }
1944
1945 static struct socket *xs_create_tcp_sock6(struct rpc_xprt *xprt,
1946                 struct sock_xprt *transport)
1947 {
1948         struct socket *sock;
1949         int err;
1950
1951         /* start from scratch */
1952         err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock);
1953         if (err < 0) {
1954                 dprintk("RPC:       can't create TCP transport socket (%d).\n",
1955                                 -err);
1956                 goto out_err;
1957         }
1958         xs_reclassify_socket6(sock);
1959
1960         if (xs_bind6(transport, sock) < 0) {
1961                 sock_release(sock);
1962                 goto out_err;
1963         }
1964         return sock;
1965 out_err:
1966         return ERR_PTR(-EIO);
1967 }
1968
1969 /**
1970  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1971  * @work: RPC transport to connect
1972  *
1973  * Invoked by a work queue tasklet.
1974  */
1975 static void xs_tcp_connect_worker6(struct work_struct *work)
1976 {
1977         struct sock_xprt *transport =
1978                 container_of(work, struct sock_xprt, connect_worker.work);
1979         struct rpc_xprt *xprt = &transport->xprt;
1980
1981         xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock6);
1982 }
1983
1984 /**
1985  * xs_connect - connect a socket to a remote endpoint
1986  * @task: address of RPC task that manages state of connect request
1987  *
1988  * TCP: If the remote end dropped the connection, delay reconnecting.
1989  *
1990  * UDP socket connects are synchronous, but we use a work queue anyway
1991  * to guarantee that even unprivileged user processes can set up a
1992  * socket on a privileged port.
1993  *
1994  * If a UDP socket connect fails, the delay behavior here prevents
1995  * retry floods (hard mounts).
1996  */
1997 static void xs_connect(struct rpc_task *task)
1998 {
1999         struct rpc_xprt *xprt = task->tk_xprt;
2000         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2001
2002         if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2003                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2004                                 "seconds\n",
2005                                 xprt, xprt->reestablish_timeout / HZ);
2006                 queue_delayed_work(rpciod_workqueue,
2007                                    &transport->connect_worker,
2008                                    xprt->reestablish_timeout);
2009                 xprt->reestablish_timeout <<= 1;
2010                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2011                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2012                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2013                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2014         } else {
2015                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2016                 queue_delayed_work(rpciod_workqueue,
2017                                    &transport->connect_worker, 0);
2018         }
2019 }
2020
2021 /**
2022  * xs_udp_print_stats - display UDP socket-specifc stats
2023  * @xprt: rpc_xprt struct containing statistics
2024  * @seq: output file
2025  *
2026  */
2027 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2028 {
2029         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2030
2031         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
2032                         transport->srcport,
2033                         xprt->stat.bind_count,
2034                         xprt->stat.sends,
2035                         xprt->stat.recvs,
2036                         xprt->stat.bad_xids,
2037                         xprt->stat.req_u,
2038                         xprt->stat.bklog_u);
2039 }
2040
2041 /**
2042  * xs_tcp_print_stats - display TCP socket-specifc stats
2043  * @xprt: rpc_xprt struct containing statistics
2044  * @seq: output file
2045  *
2046  */
2047 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2048 {
2049         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2050         long idle_time = 0;
2051
2052         if (xprt_connected(xprt))
2053                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2054
2055         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
2056                         transport->srcport,
2057                         xprt->stat.bind_count,
2058                         xprt->stat.connect_count,
2059                         xprt->stat.connect_time,
2060                         idle_time,
2061                         xprt->stat.sends,
2062                         xprt->stat.recvs,
2063                         xprt->stat.bad_xids,
2064                         xprt->stat.req_u,
2065                         xprt->stat.bklog_u);
2066 }
2067
2068 /*
2069  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2070  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2071  * to use the server side send routines.
2072  */
2073 static void *bc_malloc(struct rpc_task *task, size_t size)
2074 {
2075         struct page *page;
2076         struct rpc_buffer *buf;
2077
2078         BUG_ON(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2079         page = alloc_page(GFP_KERNEL);
2080
2081         if (!page)
2082                 return NULL;
2083
2084         buf = page_address(page);
2085         buf->len = PAGE_SIZE;
2086
2087         return buf->data;
2088 }
2089
2090 /*
2091  * Free the space allocated in the bc_alloc routine
2092  */
2093 static void bc_free(void *buffer)
2094 {
2095         struct rpc_buffer *buf;
2096
2097         if (!buffer)
2098                 return;
2099
2100         buf = container_of(buffer, struct rpc_buffer, data);
2101         free_page((unsigned long)buf);
2102 }
2103
2104 /*
2105  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2106  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2107  */
2108 static int bc_sendto(struct rpc_rqst *req)
2109 {
2110         int len;
2111         struct xdr_buf *xbufp = &req->rq_snd_buf;
2112         struct rpc_xprt *xprt = req->rq_xprt;
2113         struct sock_xprt *transport =
2114                                 container_of(xprt, struct sock_xprt, xprt);
2115         struct socket *sock = transport->sock;
2116         unsigned long headoff;
2117         unsigned long tailoff;
2118
2119         /*
2120          * Set up the rpc header and record marker stuff
2121          */
2122         xs_encode_tcp_record_marker(xbufp);
2123
2124         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2125         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2126         len = svc_send_common(sock, xbufp,
2127                               virt_to_page(xbufp->head[0].iov_base), headoff,
2128                               xbufp->tail[0].iov_base, tailoff);
2129
2130         if (len != xbufp->len) {
2131                 printk(KERN_NOTICE "Error sending entire callback!\n");
2132                 len = -EAGAIN;
2133         }
2134
2135         return len;
2136 }
2137
2138 /*
2139  * The send routine. Borrows from svc_send
2140  */
2141 static int bc_send_request(struct rpc_task *task)
2142 {
2143         struct rpc_rqst *req = task->tk_rqstp;
2144         struct svc_xprt *xprt;
2145         struct svc_sock         *svsk;
2146         u32                     len;
2147
2148         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2149         /*
2150          * Get the server socket associated with this callback xprt
2151          */
2152         xprt = req->rq_xprt->bc_xprt;
2153         svsk = container_of(xprt, struct svc_sock, sk_xprt);
2154
2155         /*
2156          * Grab the mutex to serialize data as the connection is shared
2157          * with the fore channel
2158          */
2159         if (!mutex_trylock(&xprt->xpt_mutex)) {
2160                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2161                 if (!mutex_trylock(&xprt->xpt_mutex))
2162                         return -EAGAIN;
2163                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2164         }
2165         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2166                 len = -ENOTCONN;
2167         else
2168                 len = bc_sendto(req);
2169         mutex_unlock(&xprt->xpt_mutex);
2170
2171         if (len > 0)
2172                 len = 0;
2173
2174         return len;
2175 }
2176
2177 /*
2178  * The close routine. Since this is client initiated, we do nothing
2179  */
2180
2181 static void bc_close(struct rpc_xprt *xprt)
2182 {
2183 }
2184
2185 /*
2186  * The xprt destroy routine. Again, because this connection is client
2187  * initiated, we do nothing
2188  */
2189
2190 static void bc_destroy(struct rpc_xprt *xprt)
2191 {
2192 }
2193
2194 static struct rpc_xprt_ops xs_udp_ops = {
2195         .set_buffer_size        = xs_udp_set_buffer_size,
2196         .reserve_xprt           = xprt_reserve_xprt_cong,
2197         .release_xprt           = xprt_release_xprt_cong,
2198         .rpcbind                = rpcb_getport_async,
2199         .set_port               = xs_set_port,
2200         .connect                = xs_connect,
2201         .buf_alloc              = rpc_malloc,
2202         .buf_free               = rpc_free,
2203         .send_request           = xs_udp_send_request,
2204         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2205         .timer                  = xs_udp_timer,
2206         .release_request        = xprt_release_rqst_cong,
2207         .close                  = xs_close,
2208         .destroy                = xs_destroy,
2209         .print_stats            = xs_udp_print_stats,
2210 };
2211
2212 static struct rpc_xprt_ops xs_tcp_ops = {
2213         .reserve_xprt           = xprt_reserve_xprt,
2214         .release_xprt           = xs_tcp_release_xprt,
2215         .rpcbind                = rpcb_getport_async,
2216         .set_port               = xs_set_port,
2217         .connect                = xs_connect,
2218         .buf_alloc              = rpc_malloc,
2219         .buf_free               = rpc_free,
2220         .send_request           = xs_tcp_send_request,
2221         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2222         .close                  = xs_tcp_close,
2223         .destroy                = xs_destroy,
2224         .print_stats            = xs_tcp_print_stats,
2225 };
2226
2227 /*
2228  * The rpc_xprt_ops for the server backchannel
2229  */
2230
2231 static struct rpc_xprt_ops bc_tcp_ops = {
2232         .reserve_xprt           = xprt_reserve_xprt,
2233         .release_xprt           = xprt_release_xprt,
2234         .buf_alloc              = bc_malloc,
2235         .buf_free               = bc_free,
2236         .send_request           = bc_send_request,
2237         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2238         .close                  = bc_close,
2239         .destroy                = bc_destroy,
2240         .print_stats            = xs_tcp_print_stats,
2241 };
2242
2243 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2244                                       unsigned int slot_table_size)
2245 {
2246         struct rpc_xprt *xprt;
2247         struct sock_xprt *new;
2248
2249         if (args->addrlen > sizeof(xprt->addr)) {
2250                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2251                 return ERR_PTR(-EBADF);
2252         }
2253
2254         new = kzalloc(sizeof(*new), GFP_KERNEL);
2255         if (new == NULL) {
2256                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2257                                 "rpc_xprt\n");
2258                 return ERR_PTR(-ENOMEM);
2259         }
2260         xprt = &new->xprt;
2261
2262         xprt->max_reqs = slot_table_size;
2263         xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
2264         if (xprt->slot == NULL) {
2265                 kfree(xprt);
2266                 dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
2267                                 "table\n");
2268                 return ERR_PTR(-ENOMEM);
2269         }
2270
2271         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2272         xprt->addrlen = args->addrlen;
2273         if (args->srcaddr)
2274                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2275
2276         return xprt;
2277 }
2278
2279 static const struct rpc_timeout xs_udp_default_timeout = {
2280         .to_initval = 5 * HZ,
2281         .to_maxval = 30 * HZ,
2282         .to_increment = 5 * HZ,
2283         .to_retries = 5,
2284 };
2285
2286 /**
2287  * xs_setup_udp - Set up transport to use a UDP socket
2288  * @args: rpc transport creation arguments
2289  *
2290  */
2291 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2292 {
2293         struct sockaddr *addr = args->dstaddr;
2294         struct rpc_xprt *xprt;
2295         struct sock_xprt *transport;
2296         struct rpc_xprt *ret;
2297
2298         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
2299         if (IS_ERR(xprt))
2300                 return xprt;
2301         transport = container_of(xprt, struct sock_xprt, xprt);
2302
2303         xprt->prot = IPPROTO_UDP;
2304         xprt->tsh_size = 0;
2305         /* XXX: header size can vary due to auth type, IPv6, etc. */
2306         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2307
2308         xprt->bind_timeout = XS_BIND_TO;
2309         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2310         xprt->idle_timeout = XS_IDLE_DISC_TO;
2311
2312         xprt->ops = &xs_udp_ops;
2313
2314         xprt->timeout = &xs_udp_default_timeout;
2315
2316         switch (addr->sa_family) {
2317         case AF_INET:
2318                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2319                         xprt_set_bound(xprt);
2320
2321                 INIT_DELAYED_WORK(&transport->connect_worker,
2322                                         xs_udp_connect_worker4);
2323                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2324                 break;
2325         case AF_INET6:
2326                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2327                         xprt_set_bound(xprt);
2328
2329                 INIT_DELAYED_WORK(&transport->connect_worker,
2330                                         xs_udp_connect_worker6);
2331                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2332                 break;
2333         default:
2334                 ret = ERR_PTR(-EAFNOSUPPORT);
2335                 goto out_err;
2336         }
2337
2338         if (xprt_bound(xprt))
2339                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2340                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2341                                 xprt->address_strings[RPC_DISPLAY_PORT],
2342                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2343         else
2344                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2345                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2346                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2347
2348         if (try_module_get(THIS_MODULE))
2349                 return xprt;
2350         ret = ERR_PTR(-EINVAL);
2351 out_err:
2352         kfree(xprt->slot);
2353         kfree(xprt);
2354         return ret;
2355 }
2356
2357 static const struct rpc_timeout xs_tcp_default_timeout = {
2358         .to_initval = 60 * HZ,
2359         .to_maxval = 60 * HZ,
2360         .to_retries = 2,
2361 };
2362
2363 /**
2364  * xs_setup_tcp - Set up transport to use a TCP socket
2365  * @args: rpc transport creation arguments
2366  *
2367  */
2368 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2369 {
2370         struct sockaddr *addr = args->dstaddr;
2371         struct rpc_xprt *xprt;
2372         struct sock_xprt *transport;
2373         struct rpc_xprt *ret;
2374
2375         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2376         if (IS_ERR(xprt))
2377                 return xprt;
2378         transport = container_of(xprt, struct sock_xprt, xprt);
2379
2380         xprt->prot = IPPROTO_TCP;
2381         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2382         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2383
2384         xprt->bind_timeout = XS_BIND_TO;
2385         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2386         xprt->idle_timeout = XS_IDLE_DISC_TO;
2387
2388         xprt->ops = &xs_tcp_ops;
2389         xprt->timeout = &xs_tcp_default_timeout;
2390
2391         switch (addr->sa_family) {
2392         case AF_INET:
2393                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2394                         xprt_set_bound(xprt);
2395
2396                 INIT_DELAYED_WORK(&transport->connect_worker,
2397                                         xs_tcp_connect_worker4);
2398                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2399                 break;
2400         case AF_INET6:
2401                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2402                         xprt_set_bound(xprt);
2403
2404                 INIT_DELAYED_WORK(&transport->connect_worker,
2405                                         xs_tcp_connect_worker6);
2406                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2407                 break;
2408         default:
2409                 ret = ERR_PTR(-EAFNOSUPPORT);
2410                 goto out_err;
2411         }
2412
2413         if (xprt_bound(xprt))
2414                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2415                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2416                                 xprt->address_strings[RPC_DISPLAY_PORT],
2417                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2418         else
2419                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2420                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2421                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2422
2423
2424         if (try_module_get(THIS_MODULE))
2425                 return xprt;
2426         ret = ERR_PTR(-EINVAL);
2427 out_err:
2428         kfree(xprt->slot);
2429         kfree(xprt);
2430         return ret;
2431 }
2432
2433 /**
2434  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2435  * @args: rpc transport creation arguments
2436  *
2437  */
2438 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2439 {
2440         struct sockaddr *addr = args->dstaddr;
2441         struct rpc_xprt *xprt;
2442         struct sock_xprt *transport;
2443         struct svc_sock *bc_sock;
2444         struct rpc_xprt *ret;
2445
2446         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2447         if (IS_ERR(xprt))
2448                 return xprt;
2449         transport = container_of(xprt, struct sock_xprt, xprt);
2450
2451         xprt->prot = IPPROTO_TCP;
2452         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2453         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2454         xprt->timeout = &xs_tcp_default_timeout;
2455
2456         /* backchannel */
2457         xprt_set_bound(xprt);
2458         xprt->bind_timeout = 0;
2459         xprt->reestablish_timeout = 0;
2460         xprt->idle_timeout = 0;
2461
2462         /*
2463          * The backchannel uses the same socket connection as the
2464          * forechannel
2465          */
2466         xprt->bc_xprt = args->bc_xprt;
2467         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2468         bc_sock->sk_bc_xprt = xprt;
2469         transport->sock = bc_sock->sk_sock;
2470         transport->inet = bc_sock->sk_sk;
2471
2472         xprt->ops = &bc_tcp_ops;
2473
2474         switch (addr->sa_family) {
2475         case AF_INET:
2476                 xs_format_peer_addresses(xprt, "tcp",
2477                                          RPCBIND_NETID_TCP);
2478                 break;
2479         case AF_INET6:
2480                 xs_format_peer_addresses(xprt, "tcp",
2481                                    RPCBIND_NETID_TCP6);
2482                 break;
2483         default:
2484                 ret = ERR_PTR(-EAFNOSUPPORT);
2485                 goto out_err;
2486         }
2487
2488         if (xprt_bound(xprt))
2489                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2490                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2491                                 xprt->address_strings[RPC_DISPLAY_PORT],
2492                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2493         else
2494                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2495                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2496                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2497
2498         /*
2499          * Since we don't want connections for the backchannel, we set
2500          * the xprt status to connected
2501          */
2502         xprt_set_connected(xprt);
2503
2504
2505         if (try_module_get(THIS_MODULE))
2506                 return xprt;
2507         ret = ERR_PTR(-EINVAL);
2508 out_err:
2509         kfree(xprt->slot);
2510         kfree(xprt);
2511         return ret;
2512 }
2513
2514 static struct xprt_class        xs_udp_transport = {
2515         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
2516         .name           = "udp",
2517         .owner          = THIS_MODULE,
2518         .ident          = XPRT_TRANSPORT_UDP,
2519         .setup          = xs_setup_udp,
2520 };
2521
2522 static struct xprt_class        xs_tcp_transport = {
2523         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
2524         .name           = "tcp",
2525         .owner          = THIS_MODULE,
2526         .ident          = XPRT_TRANSPORT_TCP,
2527         .setup          = xs_setup_tcp,
2528 };
2529
2530 static struct xprt_class        xs_bc_tcp_transport = {
2531         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2532         .name           = "tcp NFSv4.1 backchannel",
2533         .owner          = THIS_MODULE,
2534         .ident          = XPRT_TRANSPORT_BC_TCP,
2535         .setup          = xs_setup_bc_tcp,
2536 };
2537
2538 /**
2539  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2540  *
2541  */
2542 int init_socket_xprt(void)
2543 {
2544 #ifdef RPC_DEBUG
2545         if (!sunrpc_table_header)
2546                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
2547 #endif
2548
2549         xprt_register_transport(&xs_udp_transport);
2550         xprt_register_transport(&xs_tcp_transport);
2551         xprt_register_transport(&xs_bc_tcp_transport);
2552
2553         return 0;
2554 }
2555
2556 /**
2557  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2558  *
2559  */
2560 void cleanup_socket_xprt(void)
2561 {
2562 #ifdef RPC_DEBUG
2563         if (sunrpc_table_header) {
2564                 unregister_sysctl_table(sunrpc_table_header);
2565                 sunrpc_table_header = NULL;
2566         }
2567 #endif
2568
2569         xprt_unregister_transport(&xs_udp_transport);
2570         xprt_unregister_transport(&xs_tcp_transport);
2571         xprt_unregister_transport(&xs_bc_tcp_transport);
2572 }
2573
2574 static int param_set_uint_minmax(const char *val, struct kernel_param *kp,
2575                 unsigned int min, unsigned int max)
2576 {
2577         unsigned long num;
2578         int ret;
2579
2580         if (!val)
2581                 return -EINVAL;
2582         ret = strict_strtoul(val, 0, &num);
2583         if (ret == -EINVAL || num < min || num > max)
2584                 return -EINVAL;
2585         *((unsigned int *)kp->arg) = num;
2586         return 0;
2587 }
2588
2589 static int param_set_portnr(const char *val, struct kernel_param *kp)
2590 {
2591         return param_set_uint_minmax(val, kp,
2592                         RPC_MIN_RESVPORT,
2593                         RPC_MAX_RESVPORT);
2594 }
2595
2596 static int param_get_portnr(char *buffer, struct kernel_param *kp)
2597 {
2598         return param_get_uint(buffer, kp);
2599 }
2600 #define param_check_portnr(name, p) \
2601         __param_check(name, p, unsigned int);
2602
2603 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
2604 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
2605
2606 static int param_set_slot_table_size(const char *val, struct kernel_param *kp)
2607 {
2608         return param_set_uint_minmax(val, kp,
2609                         RPC_MIN_SLOT_TABLE,
2610                         RPC_MAX_SLOT_TABLE);
2611 }
2612
2613 static int param_get_slot_table_size(char *buffer, struct kernel_param *kp)
2614 {
2615         return param_get_uint(buffer, kp);
2616 }
2617 #define param_check_slot_table_size(name, p) \
2618         __param_check(name, p, unsigned int);
2619
2620 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
2621                    slot_table_size, 0644);
2622 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
2623                    slot_table_size, 0644);
2624