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   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 Software <alan@redhat.com>
   7  * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
   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
  18 #include <linux/types.h>
  19 #include <linux/slab.h>
  20 #include <linux/capability.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/errno.h>
  23 #include <linux/socket.h>
  24 #include <linux/in.h>
  25 #include <linux/net.h>
  26 #include <linux/mm.h>
  27 #include <linux/udp.h>
  28 #include <linux/tcp.h>
  29 #include <linux/sunrpc/clnt.h>
  30 #include <linux/sunrpc/sched.h>
  31 #include <linux/file.h>
  32
  33 #include <net/sock.h>
  34 #include <net/checksum.h>
  35 #include <net/udp.h>
  36 #include <net/tcp.h>
  37
  38 /*
  39  * xprtsock tunables
  40  */
  41 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  42 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  43
  44 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  45 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  46
  47 /*
  48  * We can register our own files under /proc/sys/sunrpc by
  49  * calling register_sysctl_table() again.  The files in that
  50  * directory become the union of all files registered there.
  51  *
  52  * We simply need to make sure that we don't collide with
  53  * someone else's file names!
  54  */
  55
  56 #ifdef RPC_DEBUG
  57
  58 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  59 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  60 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  61 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  62
  63 static struct ctl_table_header *sunrpc_table_header;
  64
  65 /*
  66  * FIXME: changing the UDP slot table size should also resize the UDP
  67  *        socket buffers for existing UDP transports
  68  */
  69 static ctl_table xs_tunables_table[] = {
  70         {
  71                 .ctl_name       = CTL_SLOTTABLE_UDP,
  72                 .procname       = "udp_slot_table_entries",
  73                 .data           = &xprt_udp_slot_table_entries,
  74                 .maxlen         = sizeof(unsigned int),
  75                 .mode           = 0644,
  76                 .proc_handler   = &proc_dointvec_minmax,
  77                 .strategy       = &sysctl_intvec,
  78                 .extra1         = &min_slot_table_size,
  79                 .extra2         = &max_slot_table_size
  80         },
  81         {
  82                 .ctl_name       = CTL_SLOTTABLE_TCP,
  83                 .procname       = "tcp_slot_table_entries",
  84                 .data           = &xprt_tcp_slot_table_entries,
  85                 .maxlen         = sizeof(unsigned int),
  86                 .mode           = 0644,
  87                 .proc_handler   = &proc_dointvec_minmax,
  88                 .strategy       = &sysctl_intvec,
  89                 .extra1         = &min_slot_table_size,
  90                 .extra2         = &max_slot_table_size
  91         },
  92         {
  93                 .ctl_name       = CTL_MIN_RESVPORT,
  94                 .procname       = "min_resvport",
  95                 .data           = &xprt_min_resvport,
  96                 .maxlen         = sizeof(unsigned int),
  97                 .mode           = 0644,
  98                 .proc_handler   = &proc_dointvec_minmax,
  99                 .strategy       = &sysctl_intvec,
 100                 .extra1         = &xprt_min_resvport_limit,
 101                 .extra2         = &xprt_max_resvport_limit
 102         },
 103         {
 104                 .ctl_name       = CTL_MAX_RESVPORT,
 105                 .procname       = "max_resvport",
 106                 .data           = &xprt_max_resvport,
 107                 .maxlen         = sizeof(unsigned int),
 108                 .mode           = 0644,
 109                 .proc_handler   = &proc_dointvec_minmax,
 110                 .strategy       = &sysctl_intvec,
 111                 .extra1         = &xprt_min_resvport_limit,
 112                 .extra2         = &xprt_max_resvport_limit
 113         },
 114         {
 115                 .ctl_name = 0,
 116         },
 117 };
 118
 119 static ctl_table sunrpc_table[] = {
 120         {
 121                 .ctl_name       = CTL_SUNRPC,
 122                 .procname       = "sunrpc",
 123                 .mode           = 0555,
 124                 .child          = xs_tunables_table
 125         },
 126         {
 127                 .ctl_name = 0,
 128         },
 129 };
 130
 131 #endif
 132
 133 /*
 134  * How many times to try sending a request on a socket before waiting
 135  * for the socket buffer to clear.
 136  */
 137 #define XS_SENDMSG_RETRY        (10U)
 138
 139 /*
 140  * Time out for an RPC UDP socket connect.  UDP socket connects are
 141  * synchronous, but we set a timeout anyway in case of resource
 142  * exhaustion on the local host.
 143  */
 144 #define XS_UDP_CONN_TO          (5U * HZ)
 145
 146 /*
 147  * Wait duration for an RPC TCP connection to be established.  Solaris
 148  * NFS over TCP uses 60 seconds, for example, which is in line with how
 149  * long a server takes to reboot.
 150  */
 151 #define XS_TCP_CONN_TO          (60U * HZ)
 152
 153 /*
 154  * Wait duration for a reply from the RPC portmapper.
 155  */
 156 #define XS_BIND_TO              (60U * HZ)
 157
 158 /*
 159  * Delay if a UDP socket connect error occurs.  This is most likely some
 160  * kind of resource problem on the local host.
 161  */
 162 #define XS_UDP_REEST_TO         (2U * HZ)
 163
 164 /*
 165  * The reestablish timeout allows clients to delay for a bit before attempting
 166  * to reconnect to a server that just dropped our connection.
 167  *
 168  * We implement an exponential backoff when trying to reestablish a TCP
 169  * transport connection with the server.  Some servers like to drop a TCP
 170  * connection when they are overworked, so we start with a short timeout and
 171  * increase over time if the server is down or not responding.
 172  */
 173 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 174 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
 175
 176 /*
 177  * TCP idle timeout; client drops the transport socket if it is idle
 178  * for this long.  Note that we also timeout UDP sockets to prevent
 179  * holding port numbers when there is no RPC traffic.
 180  */
 181 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 182
 183 #ifdef RPC_DEBUG
 184 # undef  RPC_DEBUG_DATA
 185 # define RPCDBG_FACILITY        RPCDBG_TRANS
 186 #endif
 187
 188 #ifdef RPC_DEBUG_DATA
 189 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 190 {
 191         u8 *buf = (u8 *) packet;
 192         int j;
 193
 194         dprintk("RPC:       %s\n", msg);
 195         for (j = 0; j < count && j < 128; j += 4) {
 196                 if (!(j & 31)) {
 197                         if (j)
 198                                 dprintk("\n");
 199                         dprintk("0x%04x ", j);
 200                 }
 201                 dprintk("%02x%02x%02x%02x ",
 202                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 203         }
 204         dprintk("\n");
 205 }
 206 #else
 207 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 208 {
 209         /* NOP */
 210 }
 211 #endif
 212
 213 struct sock_xprt {
 214         struct rpc_xprt         xprt;
 215
 216         /*
 217          * Network layer
 218          */
 219         struct socket *         sock;
 220         struct sock *           inet;
 221
 222         /*
 223          * State of TCP reply receive
 224          */
 225         __be32                  tcp_fraghdr,
 226                                 tcp_xid;
 227
 228         u32                     tcp_offset,
 229                                 tcp_reclen;
 230
 231         unsigned long           tcp_copied,
 232                                 tcp_flags;
 233
 234         /*
 235          * Connection of transports
 236          */
 237         struct delayed_work     connect_worker;
 238         struct sockaddr_storage addr;
 239         unsigned short          port;
 240
 241         /*
 242          * UDP socket buffer size parameters
 243          */
 244         size_t                  rcvsize,
 245                                 sndsize;
 246
 247         /*
 248          * Saved socket callback addresses
 249          */
 250         void                    (*old_data_ready)(struct sock *, int);
 251         void                    (*old_state_change)(struct sock *);
 252         void                    (*old_write_space)(struct sock *);
 253 };
 254
 255 /*
 256  * TCP receive state flags
 257  */
 258 #define TCP_RCV_LAST_FRAG       (1UL << 0)
 259 #define TCP_RCV_COPY_FRAGHDR    (1UL << 1)
 260 #define TCP_RCV_COPY_XID        (1UL << 2)
 261 #define TCP_RCV_COPY_DATA       (1UL << 3)
 262
 263 static void xs_format_ipv4_peer_addresses(struct rpc_xprt *xprt)
 264 {
 265         struct sockaddr_in *addr = (struct sockaddr_in *) &xprt->addr;
 266         char *buf;
 267
 268         buf = kzalloc(20, GFP_KERNEL);
 269         if (buf) {
 270                 snprintf(buf, 20, NIPQUAD_FMT,
 271                                 NIPQUAD(addr->sin_addr.s_addr));
 272         }
 273         xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
 274
 275         buf = kzalloc(8, GFP_KERNEL);
 276         if (buf) {
 277                 snprintf(buf, 8, "%u",
 278                                 ntohs(addr->sin_port));
 279         }
 280         xprt->address_strings[RPC_DISPLAY_PORT] = buf;
 281
 282         buf = kzalloc(8, GFP_KERNEL);
 283         if (buf) {
 284                 if (xprt->prot == IPPROTO_UDP)
 285                         snprintf(buf, 8, "udp");
 286                 else
 287                         snprintf(buf, 8, "tcp");
 288         }
 289         xprt->address_strings[RPC_DISPLAY_PROTO] = buf;
 290
 291         buf = kzalloc(48, GFP_KERNEL);
 292         if (buf) {
 293                 snprintf(buf, 48, "addr="NIPQUAD_FMT" port=%u proto=%s",
 294                         NIPQUAD(addr->sin_addr.s_addr),
 295                         ntohs(addr->sin_port),
 296                         xprt->prot == IPPROTO_UDP ? "udp" : "tcp");
 297         }
 298         xprt->address_strings[RPC_DISPLAY_ALL] = buf;
 299
 300         buf = kzalloc(10, GFP_KERNEL);
 301         if (buf) {
 302                 snprintf(buf, 10, "%02x%02x%02x%02x",
 303                                 NIPQUAD(addr->sin_addr.s_addr));
 304         }
 305         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
 306
 307         buf = kzalloc(8, GFP_KERNEL);
 308         if (buf) {
 309                 snprintf(buf, 8, "%4hx",
 310                                 ntohs(addr->sin_port));
 311         }
 312         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
 313 }
 314
 315 static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt)
 316 {
 317         struct sockaddr_in6 *addr = (struct sockaddr_in6 *) &xprt->addr;
 318         char *buf;
 319
 320         buf = kzalloc(40, GFP_KERNEL);
 321         if (buf) {
 322                 snprintf(buf, 40, NIP6_FMT,
 323                                 NIP6(addr->sin6_addr));
 324         }
 325         xprt->address_strings[RPC_DISPLAY_ADDR] = buf;
 326
 327         buf = kzalloc(8, GFP_KERNEL);
 328         if (buf) {
 329                 snprintf(buf, 8, "%u",
 330                                 ntohs(addr->sin6_port));
 331         }
 332         xprt->address_strings[RPC_DISPLAY_PORT] = buf;
 333
 334         buf = kzalloc(8, GFP_KERNEL);
 335         if (buf) {
 336                 if (xprt->prot == IPPROTO_UDP)
 337                         snprintf(buf, 8, "udp");
 338                 else
 339                         snprintf(buf, 8, "tcp");
 340         }
 341         xprt->address_strings[RPC_DISPLAY_PROTO] = buf;
 342
 343         buf = kzalloc(64, GFP_KERNEL);
 344         if (buf) {
 345                 snprintf(buf, 64, "addr="NIP6_FMT" port=%u proto=%s",
 346                                 NIP6(addr->sin6_addr),
 347                                 ntohs(addr->sin6_port),
 348                                 xprt->prot == IPPROTO_UDP ? "udp" : "tcp");
 349         }
 350         xprt->address_strings[RPC_DISPLAY_ALL] = buf;
 351
 352         buf = kzalloc(36, GFP_KERNEL);
 353         if (buf) {
 354                 snprintf(buf, 36, NIP6_SEQFMT,
 355                                 NIP6(addr->sin6_addr));
 356         }
 357         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = buf;
 358
 359         buf = kzalloc(8, GFP_KERNEL);
 360         if (buf) {
 361                 snprintf(buf, 8, "%4hx",
 362                                 ntohs(addr->sin6_port));
 363         }
 364         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = buf;
 365 }
 366
 367 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 368 {
 369         int i;
 370
 371         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 372                 kfree(xprt->address_strings[i]);
 373 }
 374
 375 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 376
 377 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
 378 {
 379         struct msghdr msg = {
 380                 .msg_name       = addr,
 381                 .msg_namelen    = addrlen,
 382                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
 383         };
 384         struct kvec iov = {
 385                 .iov_base       = vec->iov_base + base,
 386                 .iov_len        = vec->iov_len - base,
 387         };
 388
 389         if (iov.iov_len != 0)
 390                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 391         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 392 }
 393
 394 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
 395 {
 396         struct page **ppage;
 397         unsigned int remainder;
 398         int err, sent = 0;
 399
 400         remainder = xdr->page_len - base;
 401         base += xdr->page_base;
 402         ppage = xdr->pages + (base >> PAGE_SHIFT);
 403         base &= ~PAGE_MASK;
 404         for(;;) {
 405                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
 406                 int flags = XS_SENDMSG_FLAGS;
 407
 408                 remainder -= len;
 409                 if (remainder != 0 || more)
 410                         flags |= MSG_MORE;
 411                 err = sock->ops->sendpage(sock, *ppage, base, len, flags);
 412                 if (remainder == 0 || err != len)
 413                         break;
 414                 sent += err;
 415                 ppage++;
 416                 base = 0;
 417         }
 418         if (sent == 0)
 419                 return err;
 420         if (err > 0)
 421                 sent += err;
 422         return sent;
 423 }
 424
 425 /**
 426  * xs_sendpages - write pages directly to a socket
 427  * @sock: socket to send on
 428  * @addr: UDP only -- address of destination
 429  * @addrlen: UDP only -- length of destination address
 430  * @xdr: buffer containing this request
 431  * @base: starting position in the buffer
 432  *
 433  */
 434 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
 435 {
 436         unsigned int remainder = xdr->len - base;
 437         int err, sent = 0;
 438
 439         if (unlikely(!sock))
 440                 return -ENOTCONN;
 441
 442         clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
 443         if (base != 0) {
 444                 addr = NULL;
 445                 addrlen = 0;
 446         }
 447
 448         if (base < xdr->head[0].iov_len || addr != NULL) {
 449                 unsigned int len = xdr->head[0].iov_len - base;
 450                 remainder -= len;
 451                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
 452                 if (remainder == 0 || err != len)
 453                         goto out;
 454                 sent += err;
 455                 base = 0;
 456         } else
 457                 base -= xdr->head[0].iov_len;
 458
 459         if (base < xdr->page_len) {
 460                 unsigned int len = xdr->page_len - base;
 461                 remainder -= len;
 462                 err = xs_send_pagedata(sock, xdr, base, remainder != 0);
 463                 if (remainder == 0 || err != len)
 464                         goto out;
 465                 sent += err;
 466                 base = 0;
 467         } else
 468                 base -= xdr->page_len;
 469
 470         if (base >= xdr->tail[0].iov_len)
 471                 return sent;
 472         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
 473 out:
 474         if (sent == 0)
 475                 return err;
 476         if (err > 0)
 477                 sent += err;
 478         return sent;
 479 }
 480
 481 /**
 482  * xs_nospace - place task on wait queue if transmit was incomplete
 483  * @task: task to put to sleep
 484  *
 485  */
 486 static void xs_nospace(struct rpc_task *task)
 487 {
 488         struct rpc_rqst *req = task->tk_rqstp;
 489         struct rpc_xprt *xprt = req->rq_xprt;
 490         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 491
 492         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 493                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 494                         req->rq_slen);
 495
 496         if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
 497                 /* Protect against races with write_space */
 498                 spin_lock_bh(&xprt->transport_lock);
 499
 500                 /* Don't race with disconnect */
 501                 if (!xprt_connected(xprt))
 502                         task->tk_status = -ENOTCONN;
 503                 else if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
 504                         xprt_wait_for_buffer_space(task);
 505
 506                 spin_unlock_bh(&xprt->transport_lock);
 507         } else
 508                 /* Keep holding the socket if it is blocked */
 509                 rpc_delay(task, HZ>>4);
 510 }
 511
 512 /**
 513  * xs_udp_send_request - write an RPC request to a UDP socket
 514  * @task: address of RPC task that manages the state of an RPC request
 515  *
 516  * Return values:
 517  *        0:    The request has been sent
 518  *   EAGAIN:    The socket was blocked, please call again later to
 519  *              complete the request
 520  * ENOTCONN:    Caller needs to invoke connect logic then call again
 521  *    other:    Some other error occured, the request was not sent
 522  */
 523 static int xs_udp_send_request(struct rpc_task *task)
 524 {
 525         struct rpc_rqst *req = task->tk_rqstp;
 526         struct rpc_xprt *xprt = req->rq_xprt;
 527         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 528         struct xdr_buf *xdr = &req->rq_snd_buf;
 529         int status;
 530
 531         xs_pktdump("packet data:",
 532                                 req->rq_svec->iov_base,
 533                                 req->rq_svec->iov_len);
 534
 535         req->rq_xtime = jiffies;
 536         status = xs_sendpages(transport->sock,
 537                               (struct sockaddr *) &xprt->addr,
 538                               xprt->addrlen, xdr,
 539                               req->rq_bytes_sent);
 540
 541         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 542                         xdr->len - req->rq_bytes_sent, status);
 543
 544         if (likely(status >= (int) req->rq_slen))
 545                 return 0;
 546
 547         /* Still some bytes left; set up for a retry later. */
 548         if (status > 0)
 549                 status = -EAGAIN;
 550
 551         switch (status) {
 552         case -ENETUNREACH:
 553         case -EPIPE:
 554         case -ECONNREFUSED:
 555                 /* When the server has died, an ICMP port unreachable message
 556                  * prompts ECONNREFUSED. */
 557                 break;
 558         case -EAGAIN:
 559                 xs_nospace(task);
 560                 break;
 561         default:
 562                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 563                         -status);
 564                 break;
 565         }
 566
 567         return status;
 568 }
 569
 570 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
 571 {
 572         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 573         rpc_fraghdr *base = buf->head[0].iov_base;
 574         *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
 575 }
 576
 577 /**
 578  * xs_tcp_send_request - write an RPC request to a TCP socket
 579  * @task: address of RPC task that manages the state of an RPC request
 580  *
 581  * Return values:
 582  *        0:    The request has been sent
 583  *   EAGAIN:    The socket was blocked, please call again later to
 584  *              complete the request
 585  * ENOTCONN:    Caller needs to invoke connect logic then call again
 586  *    other:    Some other error occured, the request was not sent
 587  *
 588  * XXX: In the case of soft timeouts, should we eventually give up
 589  *      if sendmsg is not able to make progress?
 590  */
 591 static int xs_tcp_send_request(struct rpc_task *task)
 592 {
 593         struct rpc_rqst *req = task->tk_rqstp;
 594         struct rpc_xprt *xprt = req->rq_xprt;
 595         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 596         struct xdr_buf *xdr = &req->rq_snd_buf;
 597         int status;
 598         unsigned int retry = 0;
 599
 600         xs_encode_tcp_record_marker(&req->rq_snd_buf);
 601
 602         xs_pktdump("packet data:",
 603                                 req->rq_svec->iov_base,
 604                                 req->rq_svec->iov_len);
 605
 606         /* Continue transmitting the packet/record. We must be careful
 607          * to cope with writespace callbacks arriving _after_ we have
 608          * called sendmsg(). */
 609         while (1) {
 610                 req->rq_xtime = jiffies;
 611                 status = xs_sendpages(transport->sock,
 612                                         NULL, 0, xdr, req->rq_bytes_sent);
 613
 614                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 615                                 xdr->len - req->rq_bytes_sent, status);
 616
 617                 if (unlikely(status < 0))
 618                         break;
 619
 620                 /* If we've sent the entire packet, immediately
 621                  * reset the count of bytes sent. */
 622                 req->rq_bytes_sent += status;
 623                 task->tk_bytes_sent += status;
 624                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 625                         req->rq_bytes_sent = 0;
 626                         return 0;
 627                 }
 628
 629                 status = -EAGAIN;
 630                 if (retry++ > XS_SENDMSG_RETRY)
 631                         break;
 632         }
 633
 634         switch (status) {
 635         case -EAGAIN:
 636                 xs_nospace(task);
 637                 break;
 638         case -ECONNREFUSED:
 639         case -ECONNRESET:
 640         case -ENOTCONN:
 641         case -EPIPE:
 642                 status = -ENOTCONN;
 643                 break;
 644         default:
 645                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 646                         -status);
 647                 xprt_disconnect(xprt);
 648                 break;
 649         }
 650
 651         return status;
 652 }
 653
 654 /**
 655  * xs_tcp_release_xprt - clean up after a tcp transmission
 656  * @xprt: transport
 657  * @task: rpc task
 658  *
 659  * This cleans up if an error causes us to abort the transmission of a request.
 660  * In this case, the socket may need to be reset in order to avoid confusing
 661  * the server.
 662  */
 663 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 664 {
 665         struct rpc_rqst *req;
 666
 667         if (task != xprt->snd_task)
 668                 return;
 669         if (task == NULL)
 670                 goto out_release;
 671         req = task->tk_rqstp;
 672         if (req->rq_bytes_sent == 0)
 673                 goto out_release;
 674         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 675                 goto out_release;
 676         set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
 677 out_release:
 678         xprt_release_xprt(xprt, task);
 679 }
 680
 681 /**
 682  * xs_close - close a socket
 683  * @xprt: transport
 684  *
 685  * This is used when all requests are complete; ie, no DRC state remains
 686  * on the server we want to save.
 687  */
 688 static void xs_close(struct rpc_xprt *xprt)
 689 {
 690         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 691         struct socket *sock = transport->sock;
 692         struct sock *sk = transport->inet;
 693
 694         if (!sk)
 695                 goto clear_close_wait;
 696
 697         dprintk("RPC:       xs_close xprt %p\n", xprt);
 698
 699         write_lock_bh(&sk->sk_callback_lock);
 700         transport->inet = NULL;
 701         transport->sock = NULL;
 702
 703         sk->sk_user_data = NULL;
 704         sk->sk_data_ready = transport->old_data_ready;
 705         sk->sk_state_change = transport->old_state_change;
 706         sk->sk_write_space = transport->old_write_space;
 707         write_unlock_bh(&sk->sk_callback_lock);
 708
 709         sk->sk_no_check = 0;
 710
 711         sock_release(sock);
 712 clear_close_wait:
 713         smp_mb__before_clear_bit();
 714         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 715         smp_mb__after_clear_bit();
 716 }
 717
 718 /**
 719  * xs_destroy - prepare to shutdown a transport
 720  * @xprt: doomed transport
 721  *
 722  */
 723 static void xs_destroy(struct rpc_xprt *xprt)
 724 {
 725         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 726
 727         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 728
 729         cancel_rearming_delayed_work(&transport->connect_worker);
 730
 731         xprt_disconnect(xprt);
 732         xs_close(xprt);
 733         xs_free_peer_addresses(xprt);
 734         kfree(xprt->slot);
 735         kfree(xprt);
 736 }
 737
 738 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 739 {
 740         return (struct rpc_xprt *) sk->sk_user_data;
 741 }
 742
 743 /**
 744  * xs_udp_data_ready - "data ready" callback for UDP sockets
 745  * @sk: socket with data to read
 746  * @len: how much data to read
 747  *
 748  */
 749 static void xs_udp_data_ready(struct sock *sk, int len)
 750 {
 751         struct rpc_task *task;
 752         struct rpc_xprt *xprt;
 753         struct rpc_rqst *rovr;
 754         struct sk_buff *skb;
 755         int err, repsize, copied;
 756         u32 _xid;
 757         __be32 *xp;
 758
 759         read_lock(&sk->sk_callback_lock);
 760         dprintk("RPC:       xs_udp_data_ready...\n");
 761         if (!(xprt = xprt_from_sock(sk)))
 762                 goto out;
 763
 764         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
 765                 goto out;
 766
 767         if (xprt->shutdown)
 768                 goto dropit;
 769
 770         repsize = skb->len - sizeof(struct udphdr);
 771         if (repsize < 4) {
 772                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
 773                 goto dropit;
 774         }
 775
 776         /* Copy the XID from the skb... */
 777         xp = skb_header_pointer(skb, sizeof(struct udphdr),
 778                                 sizeof(_xid), &_xid);
 779         if (xp == NULL)
 780                 goto dropit;
 781
 782         /* Look up and lock the request corresponding to the given XID */
 783         spin_lock(&xprt->transport_lock);
 784         rovr = xprt_lookup_rqst(xprt, *xp);
 785         if (!rovr)
 786                 goto out_unlock;
 787         task = rovr->rq_task;
 788
 789         if ((copied = rovr->rq_private_buf.buflen) > repsize)
 790                 copied = repsize;
 791
 792         /* Suck it into the iovec, verify checksum if not done by hw. */
 793         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
 794                 goto out_unlock;
 795
 796         /* Something worked... */
 797         dst_confirm(skb->dst);
 798
 799         xprt_adjust_cwnd(task, copied);
 800         xprt_update_rtt(task);
 801         xprt_complete_rqst(task, copied);
 802
 803  out_unlock:
 804         spin_unlock(&xprt->transport_lock);
 805  dropit:
 806         skb_free_datagram(sk, skb);
 807  out:
 808         read_unlock(&sk->sk_callback_lock);
 809 }
 810
 811 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
 812 {
 813         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 814         size_t len, used;
 815         char *p;
 816
 817         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
 818         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
 819         used = xdr_skb_read_bits(desc, p, len);
 820         transport->tcp_offset += used;
 821         if (used != len)
 822                 return;
 823
 824         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
 825         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
 826                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
 827         else
 828                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
 829         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
 830
 831         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
 832         transport->tcp_offset = 0;
 833
 834         /* Sanity check of the record length */
 835         if (unlikely(transport->tcp_reclen < 4)) {
 836                 dprintk("RPC:       invalid TCP record fragment length\n");
 837                 xprt_disconnect(xprt);
 838                 return;
 839         }
 840         dprintk("RPC:       reading TCP record fragment of length %d\n",
 841                         transport->tcp_reclen);
 842 }
 843
 844 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
 845 {
 846         if (transport->tcp_offset == transport->tcp_reclen) {
 847                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
 848                 transport->tcp_offset = 0;
 849                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
 850                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 851                         transport->tcp_flags |= TCP_RCV_COPY_XID;
 852                         transport->tcp_copied = 0;
 853                 }
 854         }
 855 }
 856
 857 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
 858 {
 859         size_t len, used;
 860         char *p;
 861
 862         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
 863         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
 864         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
 865         used = xdr_skb_read_bits(desc, p, len);
 866         transport->tcp_offset += used;
 867         if (used != len)
 868                 return;
 869         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
 870         transport->tcp_flags |= TCP_RCV_COPY_DATA;
 871         transport->tcp_copied = 4;
 872         dprintk("RPC:       reading reply for XID %08x\n",
 873                         ntohl(transport->tcp_xid));
 874         xs_tcp_check_fraghdr(transport);
 875 }
 876
 877 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
 878 {
 879         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 880         struct rpc_rqst *req;
 881         struct xdr_buf *rcvbuf;
 882         size_t len;
 883         ssize_t r;
 884
 885         /* Find and lock the request corresponding to this xid */
 886         spin_lock(&xprt->transport_lock);
 887         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
 888         if (!req) {
 889                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 890                 dprintk("RPC:       XID %08x request not found!\n",
 891                                 ntohl(transport->tcp_xid));
 892                 spin_unlock(&xprt->transport_lock);
 893                 return;
 894         }
 895
 896         rcvbuf = &req->rq_private_buf;
 897         len = desc->count;
 898         if (len > transport->tcp_reclen - transport->tcp_offset) {
 899                 struct xdr_skb_reader my_desc;
 900
 901                 len = transport->tcp_reclen - transport->tcp_offset;
 902                 memcpy(&my_desc, desc, sizeof(my_desc));
 903                 my_desc.count = len;
 904                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
 905                                           &my_desc, xdr_skb_read_bits);
 906                 desc->count -= r;
 907                 desc->offset += r;
 908         } else
 909                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
 910                                           desc, xdr_skb_read_bits);
 911
 912         if (r > 0) {
 913                 transport->tcp_copied += r;
 914                 transport->tcp_offset += r;
 915         }
 916         if (r != len) {
 917                 /* Error when copying to the receive buffer,
 918                  * usually because we weren't able to allocate
 919                  * additional buffer pages. All we can do now
 920                  * is turn off TCP_RCV_COPY_DATA, so the request
 921                  * will not receive any additional updates,
 922                  * and time out.
 923                  * Any remaining data from this record will
 924                  * be discarded.
 925                  */
 926                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 927                 dprintk("RPC:       XID %08x truncated request\n",
 928                                 ntohl(transport->tcp_xid));
 929                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
 930                                 "tcp_offset = %u, tcp_reclen = %u\n",
 931                                 xprt, transport->tcp_copied,
 932                                 transport->tcp_offset, transport->tcp_reclen);
 933                 goto out;
 934         }
 935
 936         dprintk("RPC:       XID %08x read %Zd bytes\n",
 937                         ntohl(transport->tcp_xid), r);
 938         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
 939                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
 940                         transport->tcp_offset, transport->tcp_reclen);
 941
 942         if (transport->tcp_copied == req->rq_private_buf.buflen)
 943                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 944         else if (transport->tcp_offset == transport->tcp_reclen) {
 945                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
 946                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 947         }
 948
 949 out:
 950         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
 951                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
 952         spin_unlock(&xprt->transport_lock);
 953         xs_tcp_check_fraghdr(transport);
 954 }
 955
 956 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
 957 {
 958         size_t len;
 959
 960         len = transport->tcp_reclen - transport->tcp_offset;
 961         if (len > desc->count)
 962                 len = desc->count;
 963         desc->count -= len;
 964         desc->offset += len;
 965         transport->tcp_offset += len;
 966         dprintk("RPC:       discarded %Zu bytes\n", len);
 967         xs_tcp_check_fraghdr(transport);
 968 }
 969
 970 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
 971 {
 972         struct rpc_xprt *xprt = rd_desc->arg.data;
 973         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 974         struct xdr_skb_reader desc = {
 975                 .skb    = skb,
 976                 .offset = offset,
 977                 .count  = len,
 978         };
 979
 980         dprintk("RPC:       xs_tcp_data_recv started\n");
 981         do {
 982                 /* Read in a new fragment marker if necessary */
 983                 /* Can we ever really expect to get completely empty fragments? */
 984                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
 985                         xs_tcp_read_fraghdr(xprt, &desc);
 986                         continue;
 987                 }
 988                 /* Read in the xid if necessary */
 989                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
 990                         xs_tcp_read_xid(transport, &desc);
 991                         continue;
 992                 }
 993                 /* Read in the request data */
 994                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
 995                         xs_tcp_read_request(xprt, &desc);
 996                         continue;
 997                 }
 998                 /* Skip over any trailing bytes on short reads */
 999                 xs_tcp_read_discard(transport, &desc);
1000         } while (desc.count);
1001         dprintk("RPC:       xs_tcp_data_recv done\n");
1002         return len - desc.count;
1003 }
1004
1005 /**
1006  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1007  * @sk: socket with data to read
1008  * @bytes: how much data to read
1009  *
1010  */
1011 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1012 {
1013         struct rpc_xprt *xprt;
1014         read_descriptor_t rd_desc;
1015
1016         dprintk("RPC:       xs_tcp_data_ready...\n");
1017
1018         read_lock(&sk->sk_callback_lock);
1019         if (!(xprt = xprt_from_sock(sk)))
1020                 goto out;
1021         if (xprt->shutdown)
1022                 goto out;
1023
1024         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1025         rd_desc.arg.data = xprt;
1026         rd_desc.count = 65536;
1027         tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1028 out:
1029         read_unlock(&sk->sk_callback_lock);
1030 }
1031
1032 /**
1033  * xs_tcp_state_change - callback to handle TCP socket state changes
1034  * @sk: socket whose state has changed
1035  *
1036  */
1037 static void xs_tcp_state_change(struct sock *sk)
1038 {
1039         struct rpc_xprt *xprt;
1040
1041         read_lock(&sk->sk_callback_lock);
1042         if (!(xprt = xprt_from_sock(sk)))
1043                 goto out;
1044         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1045         dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1046                         sk->sk_state, xprt_connected(xprt),
1047                         sock_flag(sk, SOCK_DEAD),
1048                         sock_flag(sk, SOCK_ZAPPED));
1049
1050         switch (sk->sk_state) {
1051         case TCP_ESTABLISHED:
1052                 spin_lock_bh(&xprt->transport_lock);
1053                 if (!xprt_test_and_set_connected(xprt)) {
1054                         struct sock_xprt *transport = container_of(xprt,
1055                                         struct sock_xprt, xprt);
1056
1057                         /* Reset TCP record info */
1058                         transport->tcp_offset = 0;
1059                         transport->tcp_reclen = 0;
1060                         transport->tcp_copied = 0;
1061                         transport->tcp_flags =
1062                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1063
1064                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1065                         xprt_wake_pending_tasks(xprt, 0);
1066                 }
1067                 spin_unlock_bh(&xprt->transport_lock);
1068                 break;
1069         case TCP_SYN_SENT:
1070         case TCP_SYN_RECV:
1071                 break;
1072         case TCP_CLOSE_WAIT:
1073                 /* Try to schedule an autoclose RPC calls */
1074                 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
1075                 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
1076                         queue_work(rpciod_workqueue, &xprt->task_cleanup);
1077         default:
1078                 xprt_disconnect(xprt);
1079         }
1080  out:
1081         read_unlock(&sk->sk_callback_lock);
1082 }
1083
1084 /**
1085  * xs_udp_write_space - callback invoked when socket buffer space
1086  *                             becomes available
1087  * @sk: socket whose state has changed
1088  *
1089  * Called when more output buffer space is available for this socket.
1090  * We try not to wake our writers until they can make "significant"
1091  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1092  * with a bunch of small requests.
1093  */
1094 static void xs_udp_write_space(struct sock *sk)
1095 {
1096         read_lock(&sk->sk_callback_lock);
1097
1098         /* from net/core/sock.c:sock_def_write_space */
1099         if (sock_writeable(sk)) {
1100                 struct socket *sock;
1101                 struct rpc_xprt *xprt;
1102
1103                 if (unlikely(!(sock = sk->sk_socket)))
1104                         goto out;
1105                 if (unlikely(!(xprt = xprt_from_sock(sk))))
1106                         goto out;
1107                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
1108                         goto out;
1109
1110                 xprt_write_space(xprt);
1111         }
1112
1113  out:
1114         read_unlock(&sk->sk_callback_lock);
1115 }
1116
1117 /**
1118  * xs_tcp_write_space - callback invoked when socket buffer space
1119  *                             becomes available
1120  * @sk: socket whose state has changed
1121  *
1122  * Called when more output buffer space is available for this socket.
1123  * We try not to wake our writers until they can make "significant"
1124  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1125  * with a bunch of small requests.
1126  */
1127 static void xs_tcp_write_space(struct sock *sk)
1128 {
1129         read_lock(&sk->sk_callback_lock);
1130
1131         /* from net/core/stream.c:sk_stream_write_space */
1132         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
1133                 struct socket *sock;
1134                 struct rpc_xprt *xprt;
1135
1136                 if (unlikely(!(sock = sk->sk_socket)))
1137                         goto out;
1138                 if (unlikely(!(xprt = xprt_from_sock(sk))))
1139                         goto out;
1140                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
1141                         goto out;
1142
1143                 xprt_write_space(xprt);
1144         }
1145
1146  out:
1147         read_unlock(&sk->sk_callback_lock);
1148 }
1149
1150 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1151 {
1152         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1153         struct sock *sk = transport->inet;
1154
1155         if (transport->rcvsize) {
1156                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1157                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1158         }
1159         if (transport->sndsize) {
1160                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1161                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1162                 sk->sk_write_space(sk);
1163         }
1164 }
1165
1166 /**
1167  * xs_udp_set_buffer_size - set send and receive limits
1168  * @xprt: generic transport
1169  * @sndsize: requested size of send buffer, in bytes
1170  * @rcvsize: requested size of receive buffer, in bytes
1171  *
1172  * Set socket send and receive buffer size limits.
1173  */
1174 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1175 {
1176         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1177
1178         transport->sndsize = 0;
1179         if (sndsize)
1180                 transport->sndsize = sndsize + 1024;
1181         transport->rcvsize = 0;
1182         if (rcvsize)
1183                 transport->rcvsize = rcvsize + 1024;
1184
1185         xs_udp_do_set_buffer_size(xprt);
1186 }
1187
1188 /**
1189  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1190  * @task: task that timed out
1191  *
1192  * Adjust the congestion window after a retransmit timeout has occurred.
1193  */
1194 static void xs_udp_timer(struct rpc_task *task)
1195 {
1196         xprt_adjust_cwnd(task, -ETIMEDOUT);
1197 }
1198
1199 static unsigned short xs_get_random_port(void)
1200 {
1201         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1202         unsigned short rand = (unsigned short) net_random() % range;
1203         return rand + xprt_min_resvport;
1204 }
1205
1206 /**
1207  * xs_set_port - reset the port number in the remote endpoint address
1208  * @xprt: generic transport
1209  * @port: new port number
1210  *
1211  */
1212 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1213 {
1214         struct sockaddr_in *sap = (struct sockaddr_in *) &xprt->addr;
1215
1216         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1217
1218         sap->sin_port = htons(port);
1219 }
1220
1221 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1222 {
1223         struct sockaddr_in myaddr = {
1224                 .sin_family = AF_INET,
1225         };
1226         struct sockaddr_in *sa;
1227         int err;
1228         unsigned short port = transport->port;
1229
1230         if (!transport->xprt.resvport)
1231                 port = 0;
1232         sa = (struct sockaddr_in *)&transport->addr;
1233         myaddr.sin_addr = sa->sin_addr;
1234         do {
1235                 myaddr.sin_port = htons(port);
1236                 err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1237                                                 sizeof(myaddr));
1238                 if (!transport->xprt.resvport)
1239                         break;
1240                 if (err == 0) {
1241                         transport->port = port;
1242                         break;
1243                 }
1244                 if (port <= xprt_min_resvport)
1245                         port = xprt_max_resvport;
1246                 else
1247                         port--;
1248         } while (err == -EADDRINUSE && port != transport->port);
1249         dprintk("RPC:       xs_bind "NIPQUAD_FMT":%u: %s (%d)\n",
1250                 NIPQUAD(myaddr.sin_addr), port, err ? "failed" : "ok", err);
1251         return err;
1252 }
1253
1254 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1255 static struct lock_class_key xs_key[2];
1256 static struct lock_class_key xs_slock_key[2];
1257
1258 static inline void xs_reclassify_socket(struct socket *sock)
1259 {
1260         struct sock *sk = sock->sk;
1261         BUG_ON(sk->sk_lock.owner != NULL);
1262         switch (sk->sk_family) {
1263         case AF_INET:
1264                 sock_lock_init_class_and_name(sk, "slock-AF_INET-NFS",
1265                         &xs_slock_key[0], "sk_lock-AF_INET-NFS", &xs_key[0]);
1266                 break;
1267
1268         case AF_INET6:
1269                 sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFS",
1270                         &xs_slock_key[1], "sk_lock-AF_INET6-NFS", &xs_key[1]);
1271                 break;
1272
1273         default:
1274                 BUG();
1275         }
1276 }
1277 #else
1278 static inline void xs_reclassify_socket(struct socket *sock)
1279 {
1280 }
1281 #endif
1282
1283 /**
1284  * xs_udp_connect_worker - set up a UDP socket
1285  * @work: RPC transport to connect
1286  *
1287  * Invoked by a work queue tasklet.
1288  */
1289 static void xs_udp_connect_worker(struct work_struct *work)
1290 {
1291         struct sock_xprt *transport =
1292                 container_of(work, struct sock_xprt, connect_worker.work);
1293         struct rpc_xprt *xprt = &transport->xprt;
1294         struct socket *sock = transport->sock;
1295         int err, status = -EIO;
1296
1297         if (xprt->shutdown || !xprt_bound(xprt))
1298                 goto out;
1299
1300         /* Start by resetting any existing state */
1301         xs_close(xprt);
1302
1303         if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1304                 dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1305                 goto out;
1306         }
1307         xs_reclassify_socket(sock);
1308
1309         if (xs_bind(transport, sock)) {
1310                 sock_release(sock);
1311                 goto out;
1312         }
1313
1314         dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1315                         xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1316
1317         if (!transport->inet) {
1318                 struct sock *sk = sock->sk;
1319
1320                 write_lock_bh(&sk->sk_callback_lock);
1321
1322                 sk->sk_user_data = xprt;
1323                 transport->old_data_ready = sk->sk_data_ready;
1324                 transport->old_state_change = sk->sk_state_change;
1325                 transport->old_write_space = sk->sk_write_space;
1326                 sk->sk_data_ready = xs_udp_data_ready;
1327                 sk->sk_write_space = xs_udp_write_space;
1328                 sk->sk_no_check = UDP_CSUM_NORCV;
1329                 sk->sk_allocation = GFP_ATOMIC;
1330
1331                 xprt_set_connected(xprt);
1332
1333                 /* Reset to new socket */
1334                 transport->sock = sock;
1335                 transport->inet = sk;
1336
1337                 write_unlock_bh(&sk->sk_callback_lock);
1338         }
1339         xs_udp_do_set_buffer_size(xprt);
1340         status = 0;
1341 out:
1342         xprt_wake_pending_tasks(xprt, status);
1343         xprt_clear_connecting(xprt);
1344 }
1345
1346 /*
1347  * We need to preserve the port number so the reply cache on the server can
1348  * find our cached RPC replies when we get around to reconnecting.
1349  */
1350 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1351 {
1352         int result;
1353         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1354         struct sockaddr any;
1355
1356         dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1357
1358         /*
1359          * Disconnect the transport socket by doing a connect operation
1360          * with AF_UNSPEC.  This should return immediately...
1361          */
1362         memset(&any, 0, sizeof(any));
1363         any.sa_family = AF_UNSPEC;
1364         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1365         if (result)
1366                 dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1367                                 result);
1368 }
1369
1370 /**
1371  * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
1372  * @work: RPC transport to connect
1373  *
1374  * Invoked by a work queue tasklet.
1375  */
1376 static void xs_tcp_connect_worker(struct work_struct *work)
1377 {
1378         struct sock_xprt *transport =
1379                 container_of(work, struct sock_xprt, connect_worker.work);
1380         struct rpc_xprt *xprt = &transport->xprt;
1381         struct socket *sock = transport->sock;
1382         int err, status = -EIO;
1383
1384         if (xprt->shutdown || !xprt_bound(xprt))
1385                 goto out;
1386
1387         if (!sock) {
1388                 /* start from scratch */
1389                 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1390                         dprintk("RPC:       can't create TCP transport "
1391                                         "socket (%d).\n", -err);
1392                         goto out;
1393                 }
1394                 xs_reclassify_socket(sock);
1395
1396                 if (xs_bind(transport, sock)) {
1397                         sock_release(sock);
1398                         goto out;
1399                 }
1400         } else
1401                 /* "close" the socket, preserving the local port */
1402                 xs_tcp_reuse_connection(xprt);
1403
1404         dprintk("RPC:       worker connecting xprt %p to address: %s\n",
1405                         xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
1406
1407         if (!transport->inet) {
1408                 struct sock *sk = sock->sk;
1409
1410                 write_lock_bh(&sk->sk_callback_lock);
1411
1412                 sk->sk_user_data = xprt;
1413                 transport->old_data_ready = sk->sk_data_ready;
1414                 transport->old_state_change = sk->sk_state_change;
1415                 transport->old_write_space = sk->sk_write_space;
1416                 sk->sk_data_ready = xs_tcp_data_ready;
1417                 sk->sk_state_change = xs_tcp_state_change;
1418                 sk->sk_write_space = xs_tcp_write_space;
1419                 sk->sk_allocation = GFP_ATOMIC;
1420
1421                 /* socket options */
1422                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1423                 sock_reset_flag(sk, SOCK_LINGER);
1424                 tcp_sk(sk)->linger2 = 0;
1425                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1426
1427                 xprt_clear_connected(xprt);
1428
1429                 /* Reset to new socket */
1430                 transport->sock = sock;
1431                 transport->inet = sk;
1432
1433                 write_unlock_bh(&sk->sk_callback_lock);
1434         }
1435
1436         /* Tell the socket layer to start connecting... */
1437         xprt->stat.connect_count++;
1438         xprt->stat.connect_start = jiffies;
1439         status = kernel_connect(sock, (struct sockaddr *) &xprt->addr,
1440                         xprt->addrlen, O_NONBLOCK);
1441         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1442                         xprt, -status, xprt_connected(xprt),
1443                         sock->sk->sk_state);
1444         if (status < 0) {
1445                 switch (status) {
1446                         case -EINPROGRESS:
1447                         case -EALREADY:
1448                                 goto out_clear;
1449                         case -ECONNREFUSED:
1450                         case -ECONNRESET:
1451                                 /* retry with existing socket, after a delay */
1452                                 break;
1453                         default:
1454                                 /* get rid of existing socket, and retry */
1455                                 xs_close(xprt);
1456                                 break;
1457                 }
1458         }
1459 out:
1460         xprt_wake_pending_tasks(xprt, status);
1461 out_clear:
1462         xprt_clear_connecting(xprt);
1463 }
1464
1465 /**
1466  * xs_connect - connect a socket to a remote endpoint
1467  * @task: address of RPC task that manages state of connect request
1468  *
1469  * TCP: If the remote end dropped the connection, delay reconnecting.
1470  *
1471  * UDP socket connects are synchronous, but we use a work queue anyway
1472  * to guarantee that even unprivileged user processes can set up a
1473  * socket on a privileged port.
1474  *
1475  * If a UDP socket connect fails, the delay behavior here prevents
1476  * retry floods (hard mounts).
1477  */
1478 static void xs_connect(struct rpc_task *task)
1479 {
1480         struct rpc_xprt *xprt = task->tk_xprt;
1481         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1482
1483         if (xprt_test_and_set_connecting(xprt))
1484                 return;
1485
1486         if (transport->sock != NULL) {
1487                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
1488                                 "seconds\n",
1489                                 xprt, xprt->reestablish_timeout / HZ);
1490                 queue_delayed_work(rpciod_workqueue,
1491                                    &transport->connect_worker,
1492                                    xprt->reestablish_timeout);
1493                 xprt->reestablish_timeout <<= 1;
1494                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1495                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1496         } else {
1497                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
1498                 queue_delayed_work(rpciod_workqueue,
1499                                    &transport->connect_worker, 0);
1500         }
1501 }
1502
1503 /**
1504  * xs_udp_print_stats - display UDP socket-specifc stats
1505  * @xprt: rpc_xprt struct containing statistics
1506  * @seq: output file
1507  *
1508  */
1509 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1510 {
1511         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1512
1513         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1514                         transport->port,
1515                         xprt->stat.bind_count,
1516                         xprt->stat.sends,
1517                         xprt->stat.recvs,
1518                         xprt->stat.bad_xids,
1519                         xprt->stat.req_u,
1520                         xprt->stat.bklog_u);
1521 }
1522
1523 /**
1524  * xs_tcp_print_stats - display TCP socket-specifc stats
1525  * @xprt: rpc_xprt struct containing statistics
1526  * @seq: output file
1527  *
1528  */
1529 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1530 {
1531         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1532         long idle_time = 0;
1533
1534         if (xprt_connected(xprt))
1535                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
1536
1537         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1538                         transport->port,
1539                         xprt->stat.bind_count,
1540                         xprt->stat.connect_count,
1541                         xprt->stat.connect_time,
1542                         idle_time,
1543                         xprt->stat.sends,
1544                         xprt->stat.recvs,
1545                         xprt->stat.bad_xids,
1546                         xprt->stat.req_u,
1547                         xprt->stat.bklog_u);
1548 }
1549
1550 static struct rpc_xprt_ops xs_udp_ops = {
1551         .set_buffer_size        = xs_udp_set_buffer_size,
1552         .reserve_xprt           = xprt_reserve_xprt_cong,
1553         .release_xprt           = xprt_release_xprt_cong,
1554         .rpcbind                = rpcb_getport_async,
1555         .set_port               = xs_set_port,
1556         .connect                = xs_connect,
1557         .buf_alloc              = rpc_malloc,
1558         .buf_free               = rpc_free,
1559         .send_request           = xs_udp_send_request,
1560         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
1561         .timer                  = xs_udp_timer,
1562         .release_request        = xprt_release_rqst_cong,
1563         .close                  = xs_close,
1564         .destroy                = xs_destroy,
1565         .print_stats            = xs_udp_print_stats,
1566 };
1567
1568 static struct rpc_xprt_ops xs_tcp_ops = {
1569         .reserve_xprt           = xprt_reserve_xprt,
1570         .release_xprt           = xs_tcp_release_xprt,
1571         .rpcbind                = rpcb_getport_async,
1572         .set_port               = xs_set_port,
1573         .connect                = xs_connect,
1574         .buf_alloc              = rpc_malloc,
1575         .buf_free               = rpc_free,
1576         .send_request           = xs_tcp_send_request,
1577         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
1578         .close                  = xs_close,
1579         .destroy                = xs_destroy,
1580         .print_stats            = xs_tcp_print_stats,
1581 };
1582
1583 static struct rpc_xprt *xs_setup_xprt(struct rpc_xprtsock_create *args, unsigned int slot_table_size)
1584 {
1585         struct rpc_xprt *xprt;
1586         struct sock_xprt *new;
1587
1588         if (args->addrlen > sizeof(xprt->addr)) {
1589                 dprintk("RPC:       xs_setup_xprt: address too large\n");
1590                 return ERR_PTR(-EBADF);
1591         }
1592
1593         new = kzalloc(sizeof(*new), GFP_KERNEL);
1594         if (new == NULL) {
1595                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
1596                                 "rpc_xprt\n");
1597                 return ERR_PTR(-ENOMEM);
1598         }
1599         xprt = &new->xprt;
1600
1601         xprt->max_reqs = slot_table_size;
1602         xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
1603         if (xprt->slot == NULL) {
1604                 kfree(xprt);
1605                 dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
1606                                 "table\n");
1607                 return ERR_PTR(-ENOMEM);
1608         }
1609
1610         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
1611         xprt->addrlen = args->addrlen;
1612         if (args->srcaddr)
1613                 memcpy(&new->addr, args->srcaddr, args->addrlen);
1614         new->port = xs_get_random_port();
1615
1616         return xprt;
1617 }
1618
1619 /**
1620  * xs_setup_udp - Set up transport to use a UDP socket
1621  * @args: rpc transport creation arguments
1622  *
1623  */
1624 struct rpc_xprt *xs_setup_udp(struct rpc_xprtsock_create *args)
1625 {
1626         struct rpc_xprt *xprt;
1627         struct sock_xprt *transport;
1628
1629         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
1630         if (IS_ERR(xprt))
1631                 return xprt;
1632         transport = container_of(xprt, struct sock_xprt, xprt);
1633
1634         if (ntohs(((struct sockaddr_in *)args->dstaddr)->sin_port) != 0)
1635                 xprt_set_bound(xprt);
1636
1637         xprt->prot = IPPROTO_UDP;
1638         xprt->tsh_size = 0;
1639         /* XXX: header size can vary due to auth type, IPv6, etc. */
1640         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1641
1642         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_connect_worker);
1643         xprt->bind_timeout = XS_BIND_TO;
1644         xprt->connect_timeout = XS_UDP_CONN_TO;
1645         xprt->reestablish_timeout = XS_UDP_REEST_TO;
1646         xprt->idle_timeout = XS_IDLE_DISC_TO;
1647
1648         xprt->ops = &xs_udp_ops;
1649
1650         if (args->timeout)
1651                 xprt->timeout = *args->timeout;
1652         else
1653                 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
1654
1655         xs_format_ipv4_peer_addresses(xprt);
1656         dprintk("RPC:       set up transport to address %s\n",
1657                         xprt->address_strings[RPC_DISPLAY_ALL]);
1658
1659         return xprt;
1660 }
1661
1662 /**
1663  * xs_setup_tcp - Set up transport to use a TCP socket
1664  * @args: rpc transport creation arguments
1665  *
1666  */
1667 struct rpc_xprt *xs_setup_tcp(struct rpc_xprtsock_create *args)
1668 {
1669         struct rpc_xprt *xprt;
1670         struct sock_xprt *transport;
1671
1672         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
1673         if (IS_ERR(xprt))
1674                 return xprt;
1675         transport = container_of(xprt, struct sock_xprt, xprt);
1676
1677         if (ntohs(((struct sockaddr_in *)args->dstaddr)->sin_port) != 0)
1678                 xprt_set_bound(xprt);
1679
1680         xprt->prot = IPPROTO_TCP;
1681         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
1682         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
1683
1684         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_connect_worker);
1685         xprt->bind_timeout = XS_BIND_TO;
1686         xprt->connect_timeout = XS_TCP_CONN_TO;
1687         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1688         xprt->idle_timeout = XS_IDLE_DISC_TO;
1689
1690         xprt->ops = &xs_tcp_ops;
1691
1692         if (args->timeout)
1693                 xprt->timeout = *args->timeout;
1694         else
1695                 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
1696
1697         xs_format_ipv4_peer_addresses(xprt);
1698         dprintk("RPC:       set up transport to address %s\n",
1699                         xprt->address_strings[RPC_DISPLAY_ALL]);
1700
1701         return xprt;
1702 }
1703
1704 /**
1705  * init_socket_xprt - set up xprtsock's sysctls
1706  *
1707  */
1708 int init_socket_xprt(void)
1709 {
1710 #ifdef RPC_DEBUG
1711         if (!sunrpc_table_header)
1712                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
1713 #endif
1714
1715         return 0;
1716 }
1717
1718 /**
1719  * cleanup_socket_xprt - remove xprtsock's sysctls
1720  *
1721  */
1722 void cleanup_socket_xprt(void)
1723 {
1724 #ifdef RPC_DEBUG
1725         if (sunrpc_table_header) {
1726                 unregister_sysctl_table(sunrpc_table_header);
1727                 sunrpc_table_header = NULL;
1728         }
1729 #endif
1730 }