net/sunrpc/xprtsock.c

   1 /*
   2  * linux/net/sunrpc/xprtsock.c
   3  *
   4  * Client-side transport implementation for sockets.
   5  *
   6  * TCP callback races fixes (C) 1998 Red Hat
   7  * TCP send fixes (C) 1998 Red Hat
   8  * TCP NFS related read + write fixes
   9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
  10  *
  11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
  12  * Fix behaviour when socket buffer is full.
  13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  14  *
  15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
  16  *
  17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
  18  *   <gilles.quillard@bull.net>
  19  */
  20
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/capability.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/errno.h>
  28 #include <linux/socket.h>
  29 #include <linux/in.h>
  30 #include <linux/net.h>
  31 #include <linux/mm.h>
  32 #include <linux/un.h>
  33 #include <linux/udp.h>
  34 #include <linux/tcp.h>
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/sched.h>
  38 #include <linux/sunrpc/svcsock.h>
  39 #include <linux/sunrpc/xprtsock.h>
  40 #include <linux/file.h>
  41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
  42 #include <linux/sunrpc/bc_xprt.h>
  43 #endif
  44
  45 #include <net/sock.h>
  46 #include <net/checksum.h>
  47 #include <net/udp.h>
  48 #include <net/tcp.h>
  49
  50 #include "sunrpc.h"
  51
  52 static void xs_close(struct rpc_xprt *xprt);
  53
  54 /*
  55  * xprtsock tunables
  56  */
  57 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  58 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
  59 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
  60
  61 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  62 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  63
  64 #define XS_TCP_LINGER_TO        (15U * HZ)
  65 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  66
  67 /*
  68  * We can register our own files under /proc/sys/sunrpc by
  69  * calling register_sysctl_table() again.  The files in that
  70  * directory become the union of all files registered there.
  71  *
  72  * We simply need to make sure that we don't collide with
  73  * someone else's file names!
  74  */
  75
  76 #ifdef RPC_DEBUG
  77
  78 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  79 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  80 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
  81 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  82 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  83
  84 static struct ctl_table_header *sunrpc_table_header;
  85
  86 /*
  87  * FIXME: changing the UDP slot table size should also resize the UDP
  88  *        socket buffers for existing UDP transports
  89  */
  90 static struct ctl_table xs_tunables_table[] = {
  91         {
  92                 .procname       = "udp_slot_table_entries",
  93                 .data           = &xprt_udp_slot_table_entries,
  94                 .maxlen         = sizeof(unsigned int),
  95                 .mode           = 0644,
  96                 .proc_handler   = proc_dointvec_minmax,
  97                 .extra1         = &min_slot_table_size,
  98                 .extra2         = &max_slot_table_size
  99         },
 100         {
 101                 .procname       = "tcp_slot_table_entries",
 102                 .data           = &xprt_tcp_slot_table_entries,
 103                 .maxlen         = sizeof(unsigned int),
 104                 .mode           = 0644,
 105                 .proc_handler   = proc_dointvec_minmax,
 106                 .extra1         = &min_slot_table_size,
 107                 .extra2         = &max_slot_table_size
 108         },
 109         {
 110                 .procname       = "tcp_max_slot_table_entries",
 111                 .data           = &xprt_max_tcp_slot_table_entries,
 112                 .maxlen         = sizeof(unsigned int),
 113                 .mode           = 0644,
 114                 .proc_handler   = proc_dointvec_minmax,
 115                 .extra1         = &min_slot_table_size,
 116                 .extra2         = &max_tcp_slot_table_limit
 117         },
 118         {
 119                 .procname       = "min_resvport",
 120                 .data           = &xprt_min_resvport,
 121                 .maxlen         = sizeof(unsigned int),
 122                 .mode           = 0644,
 123                 .proc_handler   = proc_dointvec_minmax,
 124                 .extra1         = &xprt_min_resvport_limit,
 125                 .extra2         = &xprt_max_resvport_limit
 126         },
 127         {
 128                 .procname       = "max_resvport",
 129                 .data           = &xprt_max_resvport,
 130                 .maxlen         = sizeof(unsigned int),
 131                 .mode           = 0644,
 132                 .proc_handler   = proc_dointvec_minmax,
 133                 .extra1         = &xprt_min_resvport_limit,
 134                 .extra2         = &xprt_max_resvport_limit
 135         },
 136         {
 137                 .procname       = "tcp_fin_timeout",
 138                 .data           = &xs_tcp_fin_timeout,
 139                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 140                 .mode           = 0644,
 141                 .proc_handler   = proc_dointvec_jiffies,
 142         },
 143         { },
 144 };
 145
 146 static struct ctl_table sunrpc_table[] = {
 147         {
 148                 .procname       = "sunrpc",
 149                 .mode           = 0555,
 150                 .child          = xs_tunables_table
 151         },
 152         { },
 153 };
 154
 155 #endif
 156
 157 /*
 158  * Wait duration for a reply from the RPC portmapper.
 159  */
 160 #define XS_BIND_TO              (60U * HZ)
 161
 162 /*
 163  * Delay if a UDP socket connect error occurs.  This is most likely some
 164  * kind of resource problem on the local host.
 165  */
 166 #define XS_UDP_REEST_TO         (2U * HZ)
 167
 168 /*
 169  * The reestablish timeout allows clients to delay for a bit before attempting
 170  * to reconnect to a server that just dropped our connection.
 171  *
 172  * We implement an exponential backoff when trying to reestablish a TCP
 173  * transport connection with the server.  Some servers like to drop a TCP
 174  * connection when they are overworked, so we start with a short timeout and
 175  * increase over time if the server is down or not responding.
 176  */
 177 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 178 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
 179
 180 /*
 181  * TCP idle timeout; client drops the transport socket if it is idle
 182  * for this long.  Note that we also timeout UDP sockets to prevent
 183  * holding port numbers when there is no RPC traffic.
 184  */
 185 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 186
 187 #ifdef RPC_DEBUG
 188 # undef  RPC_DEBUG_DATA
 189 # define RPCDBG_FACILITY        RPCDBG_TRANS
 190 #endif
 191
 192 #ifdef RPC_DEBUG_DATA
 193 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 194 {
 195         u8 *buf = (u8 *) packet;
 196         int j;
 197
 198         dprintk("RPC:       %s\n", msg);
 199         for (j = 0; j < count && j < 128; j += 4) {
 200                 if (!(j & 31)) {
 201                         if (j)
 202                                 dprintk("\n");
 203                         dprintk("0x%04x ", j);
 204                 }
 205                 dprintk("%02x%02x%02x%02x ",
 206                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 207         }
 208         dprintk("\n");
 209 }
 210 #else
 211 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 212 {
 213         /* NOP */
 214 }
 215 #endif
 216
 217 struct sock_xprt {
 218         struct rpc_xprt         xprt;
 219
 220         /*
 221          * Network layer
 222          */
 223         struct socket *         sock;
 224         struct sock *           inet;
 225
 226         /*
 227          * State of TCP reply receive
 228          */
 229         __be32                  tcp_fraghdr,
 230                                 tcp_xid,
 231                                 tcp_calldir;
 232
 233         u32                     tcp_offset,
 234                                 tcp_reclen;
 235
 236         unsigned long           tcp_copied,
 237                                 tcp_flags;
 238
 239         /*
 240          * Connection of transports
 241          */
 242         struct delayed_work     connect_worker;
 243         struct sockaddr_storage srcaddr;
 244         unsigned short          srcport;
 245
 246         /*
 247          * UDP socket buffer size parameters
 248          */
 249         size_t                  rcvsize,
 250                                 sndsize;
 251
 252         /*
 253          * Saved socket callback addresses
 254          */
 255         void                    (*old_data_ready)(struct sock *, int);
 256         void                    (*old_state_change)(struct sock *);
 257         void                    (*old_write_space)(struct sock *);
 258 };
 259
 260 /*
 261  * TCP receive state flags
 262  */
 263 #define TCP_RCV_LAST_FRAG       (1UL << 0)
 264 #define TCP_RCV_COPY_FRAGHDR    (1UL << 1)
 265 #define TCP_RCV_COPY_XID        (1UL << 2)
 266 #define TCP_RCV_COPY_DATA       (1UL << 3)
 267 #define TCP_RCV_READ_CALLDIR    (1UL << 4)
 268 #define TCP_RCV_COPY_CALLDIR    (1UL << 5)
 269
 270 /*
 271  * TCP RPC flags
 272  */
 273 #define TCP_RPC_REPLY           (1UL << 6)
 274
 275 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 276 {
 277         return (struct sockaddr *) &xprt->addr;
 278 }
 279
 280 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
 281 {
 282         return (struct sockaddr_un *) &xprt->addr;
 283 }
 284
 285 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 286 {
 287         return (struct sockaddr_in *) &xprt->addr;
 288 }
 289
 290 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 291 {
 292         return (struct sockaddr_in6 *) &xprt->addr;
 293 }
 294
 295 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 296 {
 297         struct sockaddr *sap = xs_addr(xprt);
 298         struct sockaddr_in6 *sin6;
 299         struct sockaddr_in *sin;
 300         struct sockaddr_un *sun;
 301         char buf[128];
 302
 303         switch (sap->sa_family) {
 304         case AF_LOCAL:
 305                 sun = xs_addr_un(xprt);
 306                 strlcpy(buf, sun->sun_path, sizeof(buf));
 307                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 308                                                 kstrdup(buf, GFP_KERNEL);
 309                 break;
 310         case AF_INET:
 311                 (void)rpc_ntop(sap, buf, sizeof(buf));
 312                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 313                                                 kstrdup(buf, GFP_KERNEL);
 314                 sin = xs_addr_in(xprt);
 315                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 316                 break;
 317         case AF_INET6:
 318                 (void)rpc_ntop(sap, buf, sizeof(buf));
 319                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 320                                                 kstrdup(buf, GFP_KERNEL);
 321                 sin6 = xs_addr_in6(xprt);
 322                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 323                 break;
 324         default:
 325                 BUG();
 326         }
 327
 328         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 329 }
 330
 331 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 332 {
 333         struct sockaddr *sap = xs_addr(xprt);
 334         char buf[128];
 335
 336         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 337         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 338
 339         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 340         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 341 }
 342
 343 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 344                                      const char *protocol,
 345                                      const char *netid)
 346 {
 347         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 348         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 349         xs_format_common_peer_addresses(xprt);
 350         xs_format_common_peer_ports(xprt);
 351 }
 352
 353 static void xs_update_peer_port(struct rpc_xprt *xprt)
 354 {
 355         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 356         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 357
 358         xs_format_common_peer_ports(xprt);
 359 }
 360
 361 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 362 {
 363         unsigned int i;
 364
 365         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 366                 switch (i) {
 367                 case RPC_DISPLAY_PROTO:
 368                 case RPC_DISPLAY_NETID:
 369                         continue;
 370                 default:
 371                         kfree(xprt->address_strings[i]);
 372                 }
 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 -ENOTSOCK;
 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 static void xs_nospace_callback(struct rpc_task *task)
 482 {
 483         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 484
 485         transport->inet->sk_write_pending--;
 486         clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 487 }
 488
 489 /**
 490  * xs_nospace - place task on wait queue if transmit was incomplete
 491  * @task: task to put to sleep
 492  *
 493  */
 494 static int xs_nospace(struct rpc_task *task)
 495 {
 496         struct rpc_rqst *req = task->tk_rqstp;
 497         struct rpc_xprt *xprt = req->rq_xprt;
 498         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 499         int ret = -EAGAIN;
 500
 501         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 502                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 503                         req->rq_slen);
 504
 505         /* Protect against races with write_space */
 506         spin_lock_bh(&xprt->transport_lock);
 507
 508         /* Don't race with disconnect */
 509         if (xprt_connected(xprt)) {
 510                 if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
 511                         /*
 512                          * Notify TCP that we're limited by the application
 513                          * window size
 514                          */
 515                         set_bit(SOCK_NOSPACE, &transport->sock->flags);
 516                         transport->inet->sk_write_pending++;
 517                         /* ...and wait for more buffer space */
 518                         xprt_wait_for_buffer_space(task, xs_nospace_callback);
 519                 }
 520         } else {
 521                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 522                 ret = -ENOTCONN;
 523         }
 524
 525         spin_unlock_bh(&xprt->transport_lock);
 526         return ret;
 527 }
 528
 529 /*
 530  * Construct a stream transport record marker in @buf.
 531  */
 532 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
 533 {
 534         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 535         rpc_fraghdr *base = buf->head[0].iov_base;
 536         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
 537 }
 538
 539 /**
 540  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 541  * @task: RPC task that manages the state of an RPC request
 542  *
 543  * Return values:
 544  *        0:    The request has been sent
 545  *   EAGAIN:    The socket was blocked, please call again later to
 546  *              complete the request
 547  * ENOTCONN:    Caller needs to invoke connect logic then call again
 548  *    other:    Some other error occured, the request was not sent
 549  */
 550 static int xs_local_send_request(struct rpc_task *task)
 551 {
 552         struct rpc_rqst *req = task->tk_rqstp;
 553         struct rpc_xprt *xprt = req->rq_xprt;
 554         struct sock_xprt *transport =
 555                                 container_of(xprt, struct sock_xprt, xprt);
 556         struct xdr_buf *xdr = &req->rq_snd_buf;
 557         int status;
 558
 559         xs_encode_stream_record_marker(&req->rq_snd_buf);
 560
 561         xs_pktdump("packet data:",
 562                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 563
 564         status = xs_sendpages(transport->sock, NULL, 0,
 565                                                 xdr, req->rq_bytes_sent);
 566         dprintk("RPC:       %s(%u) = %d\n",
 567                         __func__, xdr->len - req->rq_bytes_sent, status);
 568         if (likely(status >= 0)) {
 569                 req->rq_bytes_sent += status;
 570                 req->rq_xmit_bytes_sent += status;
 571                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 572                         req->rq_bytes_sent = 0;
 573                         return 0;
 574                 }
 575                 status = -EAGAIN;
 576         }
 577
 578         switch (status) {
 579         case -EAGAIN:
 580                 status = xs_nospace(task);
 581                 break;
 582         default:
 583                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 584                         -status);
 585         case -EPIPE:
 586                 xs_close(xprt);
 587                 status = -ENOTCONN;
 588         }
 589
 590         return status;
 591 }
 592
 593 /**
 594  * xs_udp_send_request - write an RPC request to a UDP socket
 595  * @task: address of RPC task that manages the state of an RPC request
 596  *
 597  * Return values:
 598  *        0:    The request has been sent
 599  *   EAGAIN:    The socket was blocked, please call again later to
 600  *              complete the request
 601  * ENOTCONN:    Caller needs to invoke connect logic then call again
 602  *    other:    Some other error occurred, the request was not sent
 603  */
 604 static int xs_udp_send_request(struct rpc_task *task)
 605 {
 606         struct rpc_rqst *req = task->tk_rqstp;
 607         struct rpc_xprt *xprt = req->rq_xprt;
 608         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 609         struct xdr_buf *xdr = &req->rq_snd_buf;
 610         int status;
 611
 612         xs_pktdump("packet data:",
 613                                 req->rq_svec->iov_base,
 614                                 req->rq_svec->iov_len);
 615
 616         if (!xprt_bound(xprt))
 617                 return -ENOTCONN;
 618         status = xs_sendpages(transport->sock,
 619                               xs_addr(xprt),
 620                               xprt->addrlen, xdr,
 621                               req->rq_bytes_sent);
 622
 623         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 624                         xdr->len - req->rq_bytes_sent, status);
 625
 626         if (status >= 0) {
 627                 req->rq_xmit_bytes_sent += status;
 628                 if (status >= req->rq_slen)
 629                         return 0;
 630                 /* Still some bytes left; set up for a retry later. */
 631                 status = -EAGAIN;
 632         }
 633
 634         switch (status) {
 635         case -ENOTSOCK:
 636                 status = -ENOTCONN;
 637                 /* Should we call xs_close() here? */
 638                 break;
 639         case -EAGAIN:
 640                 status = xs_nospace(task);
 641                 break;
 642         default:
 643                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 644                         -status);
 645         case -ENETUNREACH:
 646         case -EPIPE:
 647         case -ECONNREFUSED:
 648                 /* When the server has died, an ICMP port unreachable message
 649                  * prompts ECONNREFUSED. */
 650                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 651         }
 652
 653         return status;
 654 }
 655
 656 /**
 657  * xs_tcp_shutdown - gracefully shut down a TCP socket
 658  * @xprt: transport
 659  *
 660  * Initiates a graceful shutdown of the TCP socket by calling the
 661  * equivalent of shutdown(SHUT_WR);
 662  */
 663 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 664 {
 665         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 666         struct socket *sock = transport->sock;
 667
 668         if (sock != NULL)
 669                 kernel_sock_shutdown(sock, SHUT_WR);
 670 }
 671
 672 /**
 673  * xs_tcp_send_request - write an RPC request to a TCP socket
 674  * @task: address of RPC task that manages the state of an RPC request
 675  *
 676  * Return values:
 677  *        0:    The request has been sent
 678  *   EAGAIN:    The socket was blocked, please call again later to
 679  *              complete the request
 680  * ENOTCONN:    Caller needs to invoke connect logic then call again
 681  *    other:    Some other error occurred, the request was not sent
 682  *
 683  * XXX: In the case of soft timeouts, should we eventually give up
 684  *      if sendmsg is not able to make progress?
 685  */
 686 static int xs_tcp_send_request(struct rpc_task *task)
 687 {
 688         struct rpc_rqst *req = task->tk_rqstp;
 689         struct rpc_xprt *xprt = req->rq_xprt;
 690         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 691         struct xdr_buf *xdr = &req->rq_snd_buf;
 692         int status;
 693
 694         xs_encode_stream_record_marker(&req->rq_snd_buf);
 695
 696         xs_pktdump("packet data:",
 697                                 req->rq_svec->iov_base,
 698                                 req->rq_svec->iov_len);
 699
 700         /* Continue transmitting the packet/record. We must be careful
 701          * to cope with writespace callbacks arriving _after_ we have
 702          * called sendmsg(). */
 703         while (1) {
 704                 status = xs_sendpages(transport->sock,
 705                                         NULL, 0, xdr, req->rq_bytes_sent);
 706
 707                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 708                                 xdr->len - req->rq_bytes_sent, status);
 709
 710                 if (unlikely(status < 0))
 711                         break;
 712
 713                 /* If we've sent the entire packet, immediately
 714                  * reset the count of bytes sent. */
 715                 req->rq_bytes_sent += status;
 716                 req->rq_xmit_bytes_sent += status;
 717                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 718                         req->rq_bytes_sent = 0;
 719                         return 0;
 720                 }
 721
 722                 if (status != 0)
 723                         continue;
 724                 status = -EAGAIN;
 725                 break;
 726         }
 727
 728         switch (status) {
 729         case -ENOTSOCK:
 730                 status = -ENOTCONN;
 731                 /* Should we call xs_close() here? */
 732                 break;
 733         case -EAGAIN:
 734                 status = xs_nospace(task);
 735                 break;
 736         default:
 737                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 738                         -status);
 739         case -ECONNRESET:
 740                 xs_tcp_shutdown(xprt);
 741         case -ECONNREFUSED:
 742         case -ENOTCONN:
 743         case -EPIPE:
 744                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 745         }
 746
 747         return status;
 748 }
 749
 750 /**
 751  * xs_tcp_release_xprt - clean up after a tcp transmission
 752  * @xprt: transport
 753  * @task: rpc task
 754  *
 755  * This cleans up if an error causes us to abort the transmission of a request.
 756  * In this case, the socket may need to be reset in order to avoid confusing
 757  * the server.
 758  */
 759 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 760 {
 761         struct rpc_rqst *req;
 762
 763         if (task != xprt->snd_task)
 764                 return;
 765         if (task == NULL)
 766                 goto out_release;
 767         req = task->tk_rqstp;
 768         if (req == NULL)
 769                 goto out_release;
 770         if (req->rq_bytes_sent == 0)
 771                 goto out_release;
 772         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 773                 goto out_release;
 774         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 775 out_release:
 776         xprt_release_xprt(xprt, task);
 777 }
 778
 779 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 780 {
 781         transport->old_data_ready = sk->sk_data_ready;
 782         transport->old_state_change = sk->sk_state_change;
 783         transport->old_write_space = sk->sk_write_space;
 784 }
 785
 786 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 787 {
 788         sk->sk_data_ready = transport->old_data_ready;
 789         sk->sk_state_change = transport->old_state_change;
 790         sk->sk_write_space = transport->old_write_space;
 791 }
 792
 793 static void xs_reset_transport(struct sock_xprt *transport)
 794 {
 795         struct socket *sock = transport->sock;
 796         struct sock *sk = transport->inet;
 797
 798         if (sk == NULL)
 799                 return;
 800
 801         transport->srcport = 0;
 802
 803         write_lock_bh(&sk->sk_callback_lock);
 804         transport->inet = NULL;
 805         transport->sock = NULL;
 806
 807         sk->sk_user_data = NULL;
 808
 809         xs_restore_old_callbacks(transport, sk);
 810         write_unlock_bh(&sk->sk_callback_lock);
 811
 812         sk->sk_no_check = 0;
 813
 814         sock_release(sock);
 815 }
 816
 817 /**
 818  * xs_close - close a socket
 819  * @xprt: transport
 820  *
 821  * This is used when all requests are complete; ie, no DRC state remains
 822  * on the server we want to save.
 823  *
 824  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 825  * xs_reset_transport() zeroing the socket from underneath a writer.
 826  */
 827 static void xs_close(struct rpc_xprt *xprt)
 828 {
 829         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 830
 831         dprintk("RPC:       xs_close xprt %p\n", xprt);
 832
 833         xs_reset_transport(transport);
 834         xprt->reestablish_timeout = 0;
 835
 836         smp_mb__before_clear_bit();
 837         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
 838         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 839         clear_bit(XPRT_CLOSING, &xprt->state);
 840         smp_mb__after_clear_bit();
 841         xprt_disconnect_done(xprt);
 842 }
 843
 844 static void xs_tcp_close(struct rpc_xprt *xprt)
 845 {
 846         if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
 847                 xs_close(xprt);
 848         else
 849                 xs_tcp_shutdown(xprt);
 850 }
 851
 852 static void xs_local_destroy(struct rpc_xprt *xprt)
 853 {
 854         xs_close(xprt);
 855         xs_free_peer_addresses(xprt);
 856         xprt_free(xprt);
 857         module_put(THIS_MODULE);
 858 }
 859
 860 /**
 861  * xs_destroy - prepare to shutdown a transport
 862  * @xprt: doomed transport
 863  *
 864  */
 865 static void xs_destroy(struct rpc_xprt *xprt)
 866 {
 867         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 868
 869         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 870
 871         cancel_delayed_work_sync(&transport->connect_worker);
 872
 873         xs_local_destroy(xprt);
 874 }
 875
 876 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 877 {
 878         return (struct rpc_xprt *) sk->sk_user_data;
 879 }
 880
 881 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 882 {
 883         struct xdr_skb_reader desc = {
 884                 .skb            = skb,
 885                 .offset         = sizeof(rpc_fraghdr),
 886                 .count          = skb->len - sizeof(rpc_fraghdr),
 887         };
 888
 889         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
 890                 return -1;
 891         if (desc.count)
 892                 return -1;
 893         return 0;
 894 }
 895
 896 /**
 897  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
 898  * @sk: socket with data to read
 899  * @len: how much data to read
 900  *
 901  * Currently this assumes we can read the whole reply in a single gulp.
 902  */
 903 static void xs_local_data_ready(struct sock *sk, int len)
 904 {
 905         struct rpc_task *task;
 906         struct rpc_xprt *xprt;
 907         struct rpc_rqst *rovr;
 908         struct sk_buff *skb;
 909         int err, repsize, copied;
 910         u32 _xid;
 911         __be32 *xp;
 912
 913         read_lock_bh(&sk->sk_callback_lock);
 914         dprintk("RPC:       %s...\n", __func__);
 915         xprt = xprt_from_sock(sk);
 916         if (xprt == NULL)
 917                 goto out;
 918
 919         skb = skb_recv_datagram(sk, 0, 1, &err);
 920         if (skb == NULL)
 921                 goto out;
 922
 923         repsize = skb->len - sizeof(rpc_fraghdr);
 924         if (repsize < 4) {
 925                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
 926                 goto dropit;
 927         }
 928
 929         /* Copy the XID from the skb... */
 930         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 931         if (xp == NULL)
 932                 goto dropit;
 933
 934         /* Look up and lock the request corresponding to the given XID */
 935         spin_lock(&xprt->transport_lock);
 936         rovr = xprt_lookup_rqst(xprt, *xp);
 937         if (!rovr)
 938                 goto out_unlock;
 939         task = rovr->rq_task;
 940
 941         copied = rovr->rq_private_buf.buflen;
 942         if (copied > repsize)
 943                 copied = repsize;
 944
 945         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 946                 dprintk("RPC:       sk_buff copy failed\n");
 947                 goto out_unlock;
 948         }
 949
 950         xprt_complete_rqst(task, copied);
 951
 952  out_unlock:
 953         spin_unlock(&xprt->transport_lock);
 954  dropit:
 955         skb_free_datagram(sk, skb);
 956  out:
 957         read_unlock_bh(&sk->sk_callback_lock);
 958 }
 959
 960 /**
 961  * xs_udp_data_ready - "data ready" callback for UDP sockets
 962  * @sk: socket with data to read
 963  * @len: how much data to read
 964  *
 965  */
 966 static void xs_udp_data_ready(struct sock *sk, int len)
 967 {
 968         struct rpc_task *task;
 969         struct rpc_xprt *xprt;
 970         struct rpc_rqst *rovr;
 971         struct sk_buff *skb;
 972         int err, repsize, copied;
 973         u32 _xid;
 974         __be32 *xp;
 975
 976         read_lock_bh(&sk->sk_callback_lock);
 977         dprintk("RPC:       xs_udp_data_ready...\n");
 978         if (!(xprt = xprt_from_sock(sk)))
 979                 goto out;
 980
 981         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
 982                 goto out;
 983
 984         repsize = skb->len - sizeof(struct udphdr);
 985         if (repsize < 4) {
 986                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
 987                 goto dropit;
 988         }
 989
 990         /* Copy the XID from the skb... */
 991         xp = skb_header_pointer(skb, sizeof(struct udphdr),
 992                                 sizeof(_xid), &_xid);
 993         if (xp == NULL)
 994                 goto dropit;
 995
 996         /* Look up and lock the request corresponding to the given XID */
 997         spin_lock(&xprt->transport_lock);
 998         rovr = xprt_lookup_rqst(xprt, *xp);
 999         if (!rovr)
1000                 goto out_unlock;
1001         task = rovr->rq_task;
1002
1003         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1004                 copied = repsize;
1005
1006         /* Suck it into the iovec, verify checksum if not done by hw. */
1007         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1008                 UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1009                 goto out_unlock;
1010         }
1011
1012         UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1013
1014         xprt_adjust_cwnd(xprt, task, copied);
1015         xprt_complete_rqst(task, copied);
1016
1017  out_unlock:
1018         spin_unlock(&xprt->transport_lock);
1019  dropit:
1020         skb_free_datagram(sk, skb);
1021  out:
1022         read_unlock_bh(&sk->sk_callback_lock);
1023 }
1024
1025 /*
1026  * Helper function to force a TCP close if the server is sending
1027  * junk and/or it has put us in CLOSE_WAIT
1028  */
1029 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1030 {
1031         set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1032         xprt_force_disconnect(xprt);
1033 }
1034
1035 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1036 {
1037         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1038         size_t len, used;
1039         char *p;
1040
1041         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1042         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1043         used = xdr_skb_read_bits(desc, p, len);
1044         transport->tcp_offset += used;
1045         if (used != len)
1046                 return;
1047
1048         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1049         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1050                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1051         else
1052                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1053         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1054
1055         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1056         transport->tcp_offset = 0;
1057
1058         /* Sanity check of the record length */
1059         if (unlikely(transport->tcp_reclen < 8)) {
1060                 dprintk("RPC:       invalid TCP record fragment length\n");
1061                 xs_tcp_force_close(xprt);
1062                 return;
1063         }
1064         dprintk("RPC:       reading TCP record fragment of length %d\n",
1065                         transport->tcp_reclen);
1066 }
1067
1068 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1069 {
1070         if (transport->tcp_offset == transport->tcp_reclen) {
1071                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1072                 transport->tcp_offset = 0;
1073                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1074                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1075                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1076                         transport->tcp_copied = 0;
1077                 }
1078         }
1079 }
1080
1081 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1082 {
1083         size_t len, used;
1084         char *p;
1085
1086         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1087         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1088         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1089         used = xdr_skb_read_bits(desc, p, len);
1090         transport->tcp_offset += used;
1091         if (used != len)
1092                 return;
1093         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1094         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1095         transport->tcp_copied = 4;
1096         dprintk("RPC:       reading %s XID %08x\n",
1097                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1098                                                               : "request with",
1099                         ntohl(transport->tcp_xid));
1100         xs_tcp_check_fraghdr(transport);
1101 }
1102
1103 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1104                                        struct xdr_skb_reader *desc)
1105 {
1106         size_t len, used;
1107         u32 offset;
1108         char *p;
1109
1110         /*
1111          * We want transport->tcp_offset to be 8 at the end of this routine
1112          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1113          * When this function is called for the first time,
1114          * transport->tcp_offset is 4 (after having already read the xid).
1115          */
1116         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1117         len = sizeof(transport->tcp_calldir) - offset;
1118         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1119         p = ((char *) &transport->tcp_calldir) + offset;
1120         used = xdr_skb_read_bits(desc, p, len);
1121         transport->tcp_offset += used;
1122         if (used != len)
1123                 return;
1124         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1125         /*
1126          * We don't yet have the XDR buffer, so we will write the calldir
1127          * out after we get the buffer from the 'struct rpc_rqst'
1128          */
1129         switch (ntohl(transport->tcp_calldir)) {
1130         case RPC_REPLY:
1131                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1132                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1133                 transport->tcp_flags |= TCP_RPC_REPLY;
1134                 break;
1135         case RPC_CALL:
1136                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1137                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1138                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1139                 break;
1140         default:
1141                 dprintk("RPC:       invalid request message type\n");
1142                 xs_tcp_force_close(&transport->xprt);
1143         }
1144         xs_tcp_check_fraghdr(transport);
1145 }
1146
1147 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1148                                      struct xdr_skb_reader *desc,
1149                                      struct rpc_rqst *req)
1150 {
1151         struct sock_xprt *transport =
1152                                 container_of(xprt, struct sock_xprt, xprt);
1153         struct xdr_buf *rcvbuf;
1154         size_t len;
1155         ssize_t r;
1156
1157         rcvbuf = &req->rq_private_buf;
1158
1159         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1160                 /*
1161                  * Save the RPC direction in the XDR buffer
1162                  */
1163                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1164                         &transport->tcp_calldir,
1165                         sizeof(transport->tcp_calldir));
1166                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1167                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1168         }
1169
1170         len = desc->count;
1171         if (len > transport->tcp_reclen - transport->tcp_offset) {
1172                 struct xdr_skb_reader my_desc;
1173
1174                 len = transport->tcp_reclen - transport->tcp_offset;
1175                 memcpy(&my_desc, desc, sizeof(my_desc));
1176                 my_desc.count = len;
1177                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1178                                           &my_desc, xdr_skb_read_bits);
1179                 desc->count -= r;
1180                 desc->offset += r;
1181         } else
1182                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1183                                           desc, xdr_skb_read_bits);
1184
1185         if (r > 0) {
1186                 transport->tcp_copied += r;
1187                 transport->tcp_offset += r;
1188         }
1189         if (r != len) {
1190                 /* Error when copying to the receive buffer,
1191                  * usually because we weren't able to allocate
1192                  * additional buffer pages. All we can do now
1193                  * is turn off TCP_RCV_COPY_DATA, so the request
1194                  * will not receive any additional updates,
1195                  * and time out.
1196                  * Any remaining data from this record will
1197                  * be discarded.
1198                  */
1199                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1200                 dprintk("RPC:       XID %08x truncated request\n",
1201                                 ntohl(transport->tcp_xid));
1202                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1203                                 "tcp_offset = %u, tcp_reclen = %u\n",
1204                                 xprt, transport->tcp_copied,
1205                                 transport->tcp_offset, transport->tcp_reclen);
1206                 return;
1207         }
1208
1209         dprintk("RPC:       XID %08x read %Zd bytes\n",
1210                         ntohl(transport->tcp_xid), r);
1211         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1212                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1213                         transport->tcp_offset, transport->tcp_reclen);
1214
1215         if (transport->tcp_copied == req->rq_private_buf.buflen)
1216                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1217         else if (transport->tcp_offset == transport->tcp_reclen) {
1218                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1219                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1220         }
1221 }
1222
1223 /*
1224  * Finds the request corresponding to the RPC xid and invokes the common
1225  * tcp read code to read the data.
1226  */
1227 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1228                                     struct xdr_skb_reader *desc)
1229 {
1230         struct sock_xprt *transport =
1231                                 container_of(xprt, struct sock_xprt, xprt);
1232         struct rpc_rqst *req;
1233
1234         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1235
1236         /* Find and lock the request corresponding to this xid */
1237         spin_lock(&xprt->transport_lock);
1238         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1239         if (!req) {
1240                 dprintk("RPC:       XID %08x request not found!\n",
1241                                 ntohl(transport->tcp_xid));
1242                 spin_unlock(&xprt->transport_lock);
1243                 return -1;
1244         }
1245
1246         xs_tcp_read_common(xprt, desc, req);
1247
1248         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1249                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1250
1251         spin_unlock(&xprt->transport_lock);
1252         return 0;
1253 }
1254
1255 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1256 /*
1257  * Obtains an rpc_rqst previously allocated and invokes the common
1258  * tcp read code to read the data.  The result is placed in the callback
1259  * queue.
1260  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1261  * connection and return -1.
1262  */
1263 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1264                                        struct xdr_skb_reader *desc)
1265 {
1266         struct sock_xprt *transport =
1267                                 container_of(xprt, struct sock_xprt, xprt);
1268         struct rpc_rqst *req;
1269
1270         req = xprt_alloc_bc_request(xprt);
1271         if (req == NULL) {
1272                 printk(KERN_WARNING "Callback slot table overflowed\n");
1273                 xprt_force_disconnect(xprt);
1274                 return -1;
1275         }
1276
1277         req->rq_xid = transport->tcp_xid;
1278         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1279         xs_tcp_read_common(xprt, desc, req);
1280
1281         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1282                 struct svc_serv *bc_serv = xprt->bc_serv;
1283
1284                 /*
1285                  * Add callback request to callback list.  The callback
1286                  * service sleeps on the sv_cb_waitq waiting for new
1287                  * requests.  Wake it up after adding enqueing the
1288                  * request.
1289                  */
1290                 dprintk("RPC:       add callback request to list\n");
1291                 spin_lock(&bc_serv->sv_cb_lock);
1292                 list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1293                 spin_unlock(&bc_serv->sv_cb_lock);
1294                 wake_up(&bc_serv->sv_cb_waitq);
1295         }
1296
1297         req->rq_private_buf.len = transport->tcp_copied;
1298
1299         return 0;
1300 }
1301
1302 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1303                                         struct xdr_skb_reader *desc)
1304 {
1305         struct sock_xprt *transport =
1306                                 container_of(xprt, struct sock_xprt, xprt);
1307
1308         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1309                 xs_tcp_read_reply(xprt, desc) :
1310                 xs_tcp_read_callback(xprt, desc);
1311 }
1312 #else
1313 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1314                                         struct xdr_skb_reader *desc)
1315 {
1316         return xs_tcp_read_reply(xprt, desc);
1317 }
1318 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1319
1320 /*
1321  * Read data off the transport.  This can be either an RPC_CALL or an
1322  * RPC_REPLY.  Relay the processing to helper functions.
1323  */
1324 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1325                                     struct xdr_skb_reader *desc)
1326 {
1327         struct sock_xprt *transport =
1328                                 container_of(xprt, struct sock_xprt, xprt);
1329
1330         if (_xs_tcp_read_data(xprt, desc) == 0)
1331                 xs_tcp_check_fraghdr(transport);
1332         else {
1333                 /*
1334                  * The transport_lock protects the request handling.
1335                  * There's no need to hold it to update the tcp_flags.
1336                  */
1337                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1338         }
1339 }
1340
1341 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1342 {
1343         size_t len;
1344
1345         len = transport->tcp_reclen - transport->tcp_offset;
1346         if (len > desc->count)
1347                 len = desc->count;
1348         desc->count -= len;
1349         desc->offset += len;
1350         transport->tcp_offset += len;
1351         dprintk("RPC:       discarded %Zu bytes\n", len);
1352         xs_tcp_check_fraghdr(transport);
1353 }
1354
1355 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1356 {
1357         struct rpc_xprt *xprt = rd_desc->arg.data;
1358         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1359         struct xdr_skb_reader desc = {
1360                 .skb    = skb,
1361                 .offset = offset,
1362                 .count  = len,
1363         };
1364
1365         dprintk("RPC:       xs_tcp_data_recv started\n");
1366         do {
1367                 /* Read in a new fragment marker if necessary */
1368                 /* Can we ever really expect to get completely empty fragments? */
1369                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1370                         xs_tcp_read_fraghdr(xprt, &desc);
1371                         continue;
1372                 }
1373                 /* Read in the xid if necessary */
1374                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1375                         xs_tcp_read_xid(transport, &desc);
1376                         continue;
1377                 }
1378                 /* Read in the call/reply flag */
1379                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1380                         xs_tcp_read_calldir(transport, &desc);
1381                         continue;
1382                 }
1383                 /* Read in the request data */
1384                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1385                         xs_tcp_read_data(xprt, &desc);
1386                         continue;
1387                 }
1388                 /* Skip over any trailing bytes on short reads */
1389                 xs_tcp_read_discard(transport, &desc);
1390         } while (desc.count);
1391         dprintk("RPC:       xs_tcp_data_recv done\n");
1392         return len - desc.count;
1393 }
1394
1395 /**
1396  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1397  * @sk: socket with data to read
1398  * @bytes: how much data to read
1399  *
1400  */
1401 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1402 {
1403         struct rpc_xprt *xprt;
1404         read_descriptor_t rd_desc;
1405         int read;
1406
1407         dprintk("RPC:       xs_tcp_data_ready...\n");
1408
1409         read_lock_bh(&sk->sk_callback_lock);
1410         if (!(xprt = xprt_from_sock(sk)))
1411                 goto out;
1412         /* Any data means we had a useful conversation, so
1413          * the we don't need to delay the next reconnect
1414          */
1415         if (xprt->reestablish_timeout)
1416                 xprt->reestablish_timeout = 0;
1417
1418         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1419         rd_desc.arg.data = xprt;
1420         do {
1421                 rd_desc.count = 65536;
1422                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1423         } while (read > 0);
1424 out:
1425         read_unlock_bh(&sk->sk_callback_lock);
1426 }
1427
1428 /*
1429  * Do the equivalent of linger/linger2 handling for dealing with
1430  * broken servers that don't close the socket in a timely
1431  * fashion
1432  */
1433 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1434                 unsigned long timeout)
1435 {
1436         struct sock_xprt *transport;
1437
1438         if (xprt_test_and_set_connecting(xprt))
1439                 return;
1440         set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1441         transport = container_of(xprt, struct sock_xprt, xprt);
1442         queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1443                            timeout);
1444 }
1445
1446 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1447 {
1448         struct sock_xprt *transport;
1449
1450         transport = container_of(xprt, struct sock_xprt, xprt);
1451
1452         if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1453             !cancel_delayed_work(&transport->connect_worker))
1454                 return;
1455         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1456         xprt_clear_connecting(xprt);
1457 }
1458
1459 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1460 {
1461         smp_mb__before_clear_bit();
1462         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1463         clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1464         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1465         clear_bit(XPRT_CLOSING, &xprt->state);
1466         smp_mb__after_clear_bit();
1467 }
1468
1469 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1470 {
1471         xs_sock_reset_connection_flags(xprt);
1472         /* Mark transport as closed and wake up all pending tasks */
1473         xprt_disconnect_done(xprt);
1474 }
1475
1476 /**
1477  * xs_tcp_state_change - callback to handle TCP socket state changes
1478  * @sk: socket whose state has changed
1479  *
1480  */
1481 static void xs_tcp_state_change(struct sock *sk)
1482 {
1483         struct rpc_xprt *xprt;
1484
1485         read_lock_bh(&sk->sk_callback_lock);
1486         if (!(xprt = xprt_from_sock(sk)))
1487                 goto out;
1488         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1489         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1490                         sk->sk_state, xprt_connected(xprt),
1491                         sock_flag(sk, SOCK_DEAD),
1492                         sock_flag(sk, SOCK_ZAPPED),
1493                         sk->sk_shutdown);
1494
1495         switch (sk->sk_state) {
1496         case TCP_ESTABLISHED:
1497                 spin_lock(&xprt->transport_lock);
1498                 if (!xprt_test_and_set_connected(xprt)) {
1499                         struct sock_xprt *transport = container_of(xprt,
1500                                         struct sock_xprt, xprt);
1501
1502                         /* Reset TCP record info */
1503                         transport->tcp_offset = 0;
1504                         transport->tcp_reclen = 0;
1505                         transport->tcp_copied = 0;
1506                         transport->tcp_flags =
1507                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1508
1509                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1510                 }
1511                 spin_unlock(&xprt->transport_lock);
1512                 break;
1513         case TCP_FIN_WAIT1:
1514                 /* The client initiated a shutdown of the socket */
1515                 xprt->connect_cookie++;
1516                 xprt->reestablish_timeout = 0;
1517                 set_bit(XPRT_CLOSING, &xprt->state);
1518                 smp_mb__before_clear_bit();
1519                 clear_bit(XPRT_CONNECTED, &xprt->state);
1520                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1521                 smp_mb__after_clear_bit();
1522                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1523                 break;
1524         case TCP_CLOSE_WAIT:
1525                 /* The server initiated a shutdown of the socket */
1526                 xprt->connect_cookie++;
1527                 clear_bit(XPRT_CONNECTED, &xprt->state);
1528                 xs_tcp_force_close(xprt);
1529         case TCP_CLOSING:
1530                 /*
1531                  * If the server closed down the connection, make sure that
1532                  * we back off before reconnecting
1533                  */
1534                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1535                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1536                 break;
1537         case TCP_LAST_ACK:
1538                 set_bit(XPRT_CLOSING, &xprt->state);
1539                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1540                 smp_mb__before_clear_bit();
1541                 clear_bit(XPRT_CONNECTED, &xprt->state);
1542                 smp_mb__after_clear_bit();
1543                 break;
1544         case TCP_CLOSE:
1545                 xs_tcp_cancel_linger_timeout(xprt);
1546                 xs_sock_mark_closed(xprt);
1547         }
1548  out:
1549         read_unlock_bh(&sk->sk_callback_lock);
1550 }
1551
1552 static void xs_write_space(struct sock *sk)
1553 {
1554         struct socket *sock;
1555         struct rpc_xprt *xprt;
1556
1557         if (unlikely(!(sock = sk->sk_socket)))
1558                 return;
1559         clear_bit(SOCK_NOSPACE, &sock->flags);
1560
1561         if (unlikely(!(xprt = xprt_from_sock(sk))))
1562                 return;
1563         if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1564                 return;
1565
1566         xprt_write_space(xprt);
1567 }
1568
1569 /**
1570  * xs_udp_write_space - callback invoked when socket buffer space
1571  *                             becomes available
1572  * @sk: socket whose state has changed
1573  *
1574  * Called when more output buffer space is available for this socket.
1575  * We try not to wake our writers until they can make "significant"
1576  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1577  * with a bunch of small requests.
1578  */
1579 static void xs_udp_write_space(struct sock *sk)
1580 {
1581         read_lock_bh(&sk->sk_callback_lock);
1582
1583         /* from net/core/sock.c:sock_def_write_space */
1584         if (sock_writeable(sk))
1585                 xs_write_space(sk);
1586
1587         read_unlock_bh(&sk->sk_callback_lock);
1588 }
1589
1590 /**
1591  * xs_tcp_write_space - callback invoked when socket buffer space
1592  *                             becomes available
1593  * @sk: socket whose state has changed
1594  *
1595  * Called when more output buffer space is available for this socket.
1596  * We try not to wake our writers until they can make "significant"
1597  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1598  * with a bunch of small requests.
1599  */
1600 static void xs_tcp_write_space(struct sock *sk)
1601 {
1602         read_lock_bh(&sk->sk_callback_lock);
1603
1604         /* from net/core/stream.c:sk_stream_write_space */
1605         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
1606                 xs_write_space(sk);
1607
1608         read_unlock_bh(&sk->sk_callback_lock);
1609 }
1610
1611 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1612 {
1613         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1614         struct sock *sk = transport->inet;
1615
1616         if (transport->rcvsize) {
1617                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1618                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1619         }
1620         if (transport->sndsize) {
1621                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1622                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1623                 sk->sk_write_space(sk);
1624         }
1625 }
1626
1627 /**
1628  * xs_udp_set_buffer_size - set send and receive limits
1629  * @xprt: generic transport
1630  * @sndsize: requested size of send buffer, in bytes
1631  * @rcvsize: requested size of receive buffer, in bytes
1632  *
1633  * Set socket send and receive buffer size limits.
1634  */
1635 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1636 {
1637         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1638
1639         transport->sndsize = 0;
1640         if (sndsize)
1641                 transport->sndsize = sndsize + 1024;
1642         transport->rcvsize = 0;
1643         if (rcvsize)
1644                 transport->rcvsize = rcvsize + 1024;
1645
1646         xs_udp_do_set_buffer_size(xprt);
1647 }
1648
1649 /**
1650  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1651  * @task: task that timed out
1652  *
1653  * Adjust the congestion window after a retransmit timeout has occurred.
1654  */
1655 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1656 {
1657         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1658 }
1659
1660 static unsigned short xs_get_random_port(void)
1661 {
1662         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1663         unsigned short rand = (unsigned short) net_random() % range;
1664         return rand + xprt_min_resvport;
1665 }
1666
1667 /**
1668  * xs_set_port - reset the port number in the remote endpoint address
1669  * @xprt: generic transport
1670  * @port: new port number
1671  *
1672  */
1673 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1674 {
1675         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1676
1677         rpc_set_port(xs_addr(xprt), port);
1678         xs_update_peer_port(xprt);
1679 }
1680
1681 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1682 {
1683         unsigned short port = transport->srcport;
1684
1685         if (port == 0 && transport->xprt.resvport)
1686                 port = xs_get_random_port();
1687         return port;
1688 }
1689
1690 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1691 {
1692         if (transport->srcport != 0)
1693                 transport->srcport = 0;
1694         if (!transport->xprt.resvport)
1695                 return 0;
1696         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1697                 return xprt_max_resvport;
1698         return --port;
1699 }
1700 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1701 {
1702         struct sockaddr_storage myaddr;
1703         int err, nloop = 0;
1704         unsigned short port = xs_get_srcport(transport);
1705         unsigned short last;
1706
1707         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1708         do {
1709                 rpc_set_port((struct sockaddr *)&myaddr, port);
1710                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1711                                 transport->xprt.addrlen);
1712                 if (port == 0)
1713                         break;
1714                 if (err == 0) {
1715                         transport->srcport = port;
1716                         break;
1717                 }
1718                 last = port;
1719                 port = xs_next_srcport(transport, port);
1720                 if (port > last)
1721                         nloop++;
1722         } while (err == -EADDRINUSE && nloop != 2);
1723
1724         if (myaddr.ss_family == AF_INET)
1725                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1726                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1727                                 port, err ? "failed" : "ok", err);
1728         else
1729                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1730                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1731                                 port, err ? "failed" : "ok", err);
1732         return err;
1733 }
1734
1735 /*
1736  * We don't support autobind on AF_LOCAL sockets
1737  */
1738 static void xs_local_rpcbind(struct rpc_task *task)
1739 {
1740         rcu_read_lock();
1741         xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1742         rcu_read_unlock();
1743 }
1744
1745 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1746 {
1747 }
1748
1749 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1750 static struct lock_class_key xs_key[2];
1751 static struct lock_class_key xs_slock_key[2];
1752
1753 static inline void xs_reclassify_socketu(struct socket *sock)
1754 {
1755         struct sock *sk = sock->sk;
1756
1757         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1758                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1759 }
1760
1761 static inline void xs_reclassify_socket4(struct socket *sock)
1762 {
1763         struct sock *sk = sock->sk;
1764
1765         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1766                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1767 }
1768
1769 static inline void xs_reclassify_socket6(struct socket *sock)
1770 {
1771         struct sock *sk = sock->sk;
1772
1773         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1774                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1775 }
1776
1777 static inline void xs_reclassify_socket(int family, struct socket *sock)
1778 {
1779         WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1780         if (sock_owned_by_user(sock->sk))
1781                 return;
1782
1783         switch (family) {
1784         case AF_LOCAL:
1785                 xs_reclassify_socketu(sock);
1786                 break;
1787         case AF_INET:
1788                 xs_reclassify_socket4(sock);
1789                 break;
1790         case AF_INET6:
1791                 xs_reclassify_socket6(sock);
1792                 break;
1793         }
1794 }
1795 #else
1796 static inline void xs_reclassify_socketu(struct socket *sock)
1797 {
1798 }
1799
1800 static inline void xs_reclassify_socket4(struct socket *sock)
1801 {
1802 }
1803
1804 static inline void xs_reclassify_socket6(struct socket *sock)
1805 {
1806 }
1807
1808 static inline void xs_reclassify_socket(int family, struct socket *sock)
1809 {
1810 }
1811 #endif
1812
1813 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1814                 struct sock_xprt *transport, int family, int type, int protocol)
1815 {
1816         struct socket *sock;
1817         int err;
1818
1819         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1820         if (err < 0) {
1821                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1822                                 protocol, -err);
1823                 goto out;
1824         }
1825         xs_reclassify_socket(family, sock);
1826
1827         err = xs_bind(transport, sock);
1828         if (err) {
1829                 sock_release(sock);
1830                 goto out;
1831         }
1832
1833         return sock;
1834 out:
1835         return ERR_PTR(err);
1836 }
1837
1838 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1839                                       struct socket *sock)
1840 {
1841         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1842                                                                         xprt);
1843
1844         if (!transport->inet) {
1845                 struct sock *sk = sock->sk;
1846
1847                 write_lock_bh(&sk->sk_callback_lock);
1848
1849                 xs_save_old_callbacks(transport, sk);
1850
1851                 sk->sk_user_data = xprt;
1852                 sk->sk_data_ready = xs_local_data_ready;
1853                 sk->sk_write_space = xs_udp_write_space;
1854                 sk->sk_allocation = GFP_ATOMIC;
1855
1856                 xprt_clear_connected(xprt);
1857
1858                 /* Reset to new socket */
1859                 transport->sock = sock;
1860                 transport->inet = sk;
1861
1862                 write_unlock_bh(&sk->sk_callback_lock);
1863         }
1864
1865         /* Tell the socket layer to start connecting... */
1866         xprt->stat.connect_count++;
1867         xprt->stat.connect_start = jiffies;
1868         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1869 }
1870
1871 /**
1872  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1873  * @xprt: RPC transport to connect
1874  * @transport: socket transport to connect
1875  * @create_sock: function to create a socket of the correct type
1876  */
1877 static int xs_local_setup_socket(struct sock_xprt *transport)
1878 {
1879         struct rpc_xprt *xprt = &transport->xprt;
1880         struct socket *sock;
1881         int status = -EIO;
1882
1883         current->flags |= PF_FSTRANS;
1884
1885         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1886         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1887                                         SOCK_STREAM, 0, &sock, 1);
1888         if (status < 0) {
1889                 dprintk("RPC:       can't create AF_LOCAL "
1890                         "transport socket (%d).\n", -status);
1891                 goto out;
1892         }
1893         xs_reclassify_socketu(sock);
1894
1895         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1896                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1897
1898         status = xs_local_finish_connecting(xprt, sock);
1899         switch (status) {
1900         case 0:
1901                 dprintk("RPC:       xprt %p connected to %s\n",
1902                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1903                 xprt_set_connected(xprt);
1904                 break;
1905         case -ENOENT:
1906                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1907                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1908                 break;
1909         case -ECONNREFUSED:
1910                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1911                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1912                 break;
1913         default:
1914                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1915                                 __func__, -status,
1916                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1917         }
1918
1919 out:
1920         xprt_clear_connecting(xprt);
1921         xprt_wake_pending_tasks(xprt, status);
1922         current->flags &= ~PF_FSTRANS;
1923         return status;
1924 }
1925
1926 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1927 {
1928         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1929         int ret;
1930
1931          if (RPC_IS_ASYNC(task)) {
1932                 /*
1933                  * We want the AF_LOCAL connect to be resolved in the
1934                  * filesystem namespace of the process making the rpc
1935                  * call.  Thus we connect synchronously.
1936                  *
1937                  * If we want to support asynchronous AF_LOCAL calls,
1938                  * we'll need to figure out how to pass a namespace to
1939                  * connect.
1940                  */
1941                 rpc_exit(task, -ENOTCONN);
1942                 return;
1943         }
1944         ret = xs_local_setup_socket(transport);
1945         if (ret && !RPC_IS_SOFTCONN(task))
1946                 msleep_interruptible(15000);
1947 }
1948
1949 #ifdef CONFIG_SUNRPC_SWAP
1950 static void xs_set_memalloc(struct rpc_xprt *xprt)
1951 {
1952         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1953                         xprt);
1954
1955         if (xprt->swapper)
1956                 sk_set_memalloc(transport->inet);
1957 }
1958
1959 /**
1960  * xs_swapper - Tag this transport as being used for swap.
1961  * @xprt: transport to tag
1962  * @enable: enable/disable
1963  *
1964  */
1965 int xs_swapper(struct rpc_xprt *xprt, int enable)
1966 {
1967         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1968                         xprt);
1969         int err = 0;
1970
1971         if (enable) {
1972                 xprt->swapper++;
1973                 xs_set_memalloc(xprt);
1974         } else if (xprt->swapper) {
1975                 xprt->swapper--;
1976                 sk_clear_memalloc(transport->inet);
1977         }
1978
1979         return err;
1980 }
1981 EXPORT_SYMBOL_GPL(xs_swapper);
1982 #else
1983 static void xs_set_memalloc(struct rpc_xprt *xprt)
1984 {
1985 }
1986 #endif
1987
1988 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1989 {
1990         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1991
1992         if (!transport->inet) {
1993                 struct sock *sk = sock->sk;
1994
1995                 write_lock_bh(&sk->sk_callback_lock);
1996
1997                 xs_save_old_callbacks(transport, sk);
1998
1999                 sk->sk_user_data = xprt;
2000                 sk->sk_data_ready = xs_udp_data_ready;
2001                 sk->sk_write_space = xs_udp_write_space;
2002                 sk->sk_no_check = UDP_CSUM_NORCV;
2003                 sk->sk_allocation = GFP_ATOMIC;
2004
2005                 xprt_set_connected(xprt);
2006
2007                 /* Reset to new socket */
2008                 transport->sock = sock;
2009                 transport->inet = sk;
2010
2011                 xs_set_memalloc(xprt);
2012
2013                 write_unlock_bh(&sk->sk_callback_lock);
2014         }
2015         xs_udp_do_set_buffer_size(xprt);
2016 }
2017
2018 static void xs_udp_setup_socket(struct work_struct *work)
2019 {
2020         struct sock_xprt *transport =
2021                 container_of(work, struct sock_xprt, connect_worker.work);
2022         struct rpc_xprt *xprt = &transport->xprt;
2023         struct socket *sock = transport->sock;
2024         int status = -EIO;
2025
2026         current->flags |= PF_FSTRANS;
2027
2028         /* Start by resetting any existing state */
2029         xs_reset_transport(transport);
2030         sock = xs_create_sock(xprt, transport,
2031                         xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2032         if (IS_ERR(sock))
2033                 goto out;
2034
2035         dprintk("RPC:       worker connecting xprt %p via %s to "
2036                                 "%s (port %s)\n", xprt,
2037                         xprt->address_strings[RPC_DISPLAY_PROTO],
2038                         xprt->address_strings[RPC_DISPLAY_ADDR],
2039                         xprt->address_strings[RPC_DISPLAY_PORT]);
2040
2041         xs_udp_finish_connecting(xprt, sock);
2042         status = 0;
2043 out:
2044         xprt_clear_connecting(xprt);
2045         xprt_wake_pending_tasks(xprt, status);
2046         current->flags &= ~PF_FSTRANS;
2047 }
2048
2049 /*
2050  * We need to preserve the port number so the reply cache on the server can
2051  * find our cached RPC replies when we get around to reconnecting.
2052  */
2053 static void xs_abort_connection(struct sock_xprt *transport)
2054 {
2055         int result;
2056         struct sockaddr any;
2057
2058         dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2059
2060         /*
2061          * Disconnect the transport socket by doing a connect operation
2062          * with AF_UNSPEC.  This should return immediately...
2063          */
2064         memset(&any, 0, sizeof(any));
2065         any.sa_family = AF_UNSPEC;
2066         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2067         if (!result)
2068                 xs_sock_reset_connection_flags(&transport->xprt);
2069         dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2070 }
2071
2072 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2073 {
2074         unsigned int state = transport->inet->sk_state;
2075
2076         if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2077                 /* we don't need to abort the connection if the socket
2078                  * hasn't undergone a shutdown
2079                  */
2080                 if (transport->inet->sk_shutdown == 0)
2081                         return;
2082                 dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2083                                 __func__, transport->inet->sk_shutdown);
2084         }
2085         if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2086                 /* we don't need to abort the connection if the socket
2087                  * hasn't undergone a shutdown
2088                  */
2089                 if (transport->inet->sk_shutdown == 0)
2090                         return;
2091                 dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2092                                 "sk_shutdown set to %d\n",
2093                                 __func__, transport->inet->sk_shutdown);
2094         }
2095         xs_abort_connection(transport);
2096 }
2097
2098 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2099 {
2100         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2101         int ret = -ENOTCONN;
2102
2103         if (!transport->inet) {
2104                 struct sock *sk = sock->sk;
2105
2106                 write_lock_bh(&sk->sk_callback_lock);
2107
2108                 xs_save_old_callbacks(transport, sk);
2109
2110                 sk->sk_user_data = xprt;
2111                 sk->sk_data_ready = xs_tcp_data_ready;
2112                 sk->sk_state_change = xs_tcp_state_change;
2113                 sk->sk_write_space = xs_tcp_write_space;
2114                 sk->sk_allocation = GFP_ATOMIC;
2115
2116                 /* socket options */
2117                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2118                 sock_reset_flag(sk, SOCK_LINGER);
2119                 tcp_sk(sk)->linger2 = 0;
2120                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2121
2122                 xprt_clear_connected(xprt);
2123
2124                 /* Reset to new socket */
2125                 transport->sock = sock;
2126                 transport->inet = sk;
2127
2128                 write_unlock_bh(&sk->sk_callback_lock);
2129         }
2130
2131         if (!xprt_bound(xprt))
2132                 goto out;
2133
2134         xs_set_memalloc(xprt);
2135
2136         /* Tell the socket layer to start connecting... */
2137         xprt->stat.connect_count++;
2138         xprt->stat.connect_start = jiffies;
2139         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2140         switch (ret) {
2141         case 0:
2142         case -EINPROGRESS:
2143                 /* SYN_SENT! */
2144                 xprt->connect_cookie++;
2145                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2146                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2147         }
2148 out:
2149         return ret;
2150 }
2151
2152 /**
2153  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2154  * @xprt: RPC transport to connect
2155  * @transport: socket transport to connect
2156  * @create_sock: function to create a socket of the correct type
2157  *
2158  * Invoked by a work queue tasklet.
2159  */
2160 static void xs_tcp_setup_socket(struct work_struct *work)
2161 {
2162         struct sock_xprt *transport =
2163                 container_of(work, struct sock_xprt, connect_worker.work);
2164         struct socket *sock = transport->sock;
2165         struct rpc_xprt *xprt = &transport->xprt;
2166         int status = -EIO;
2167
2168         current->flags |= PF_FSTRANS;
2169
2170         if (!sock) {
2171                 clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2172                 sock = xs_create_sock(xprt, transport,
2173                                 xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2174                 if (IS_ERR(sock)) {
2175                         status = PTR_ERR(sock);
2176                         goto out;
2177                 }
2178         } else {
2179                 int abort_and_exit;
2180
2181                 abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2182                                 &xprt->state);
2183                 /* "close" the socket, preserving the local port */
2184                 xs_tcp_reuse_connection(transport);
2185
2186                 if (abort_and_exit)
2187                         goto out_eagain;
2188         }
2189
2190         dprintk("RPC:       worker connecting xprt %p via %s to "
2191                                 "%s (port %s)\n", xprt,
2192                         xprt->address_strings[RPC_DISPLAY_PROTO],
2193                         xprt->address_strings[RPC_DISPLAY_ADDR],
2194                         xprt->address_strings[RPC_DISPLAY_PORT]);
2195
2196         status = xs_tcp_finish_connecting(xprt, sock);
2197         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2198                         xprt, -status, xprt_connected(xprt),
2199                         sock->sk->sk_state);
2200         switch (status) {
2201         default:
2202                 printk("%s: connect returned unhandled error %d\n",
2203                         __func__, status);
2204         case -EADDRNOTAVAIL:
2205                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2206                  * and retry
2207                  */
2208                 xs_tcp_force_close(xprt);
2209                 break;
2210         case 0:
2211         case -EINPROGRESS:
2212         case -EALREADY:
2213                 xprt_clear_connecting(xprt);
2214                 current->flags &= ~PF_FSTRANS;
2215                 return;
2216         case -EINVAL:
2217                 /* Happens, for instance, if the user specified a link
2218                  * local IPv6 address without a scope-id.
2219                  */
2220         case -ECONNREFUSED:
2221         case -ECONNRESET:
2222         case -ENETUNREACH:
2223                 /* retry with existing socket, after a delay */
2224                 goto out;
2225         }
2226 out_eagain:
2227         status = -EAGAIN;
2228 out:
2229         xprt_clear_connecting(xprt);
2230         xprt_wake_pending_tasks(xprt, status);
2231         current->flags &= ~PF_FSTRANS;
2232 }
2233
2234 /**
2235  * xs_connect - connect a socket to a remote endpoint
2236  * @xprt: pointer to transport structure
2237  * @task: address of RPC task that manages state of connect request
2238  *
2239  * TCP: If the remote end dropped the connection, delay reconnecting.
2240  *
2241  * UDP socket connects are synchronous, but we use a work queue anyway
2242  * to guarantee that even unprivileged user processes can set up a
2243  * socket on a privileged port.
2244  *
2245  * If a UDP socket connect fails, the delay behavior here prevents
2246  * retry floods (hard mounts).
2247  */
2248 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2249 {
2250         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2251
2252         if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2253                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2254                                 "seconds\n",
2255                                 xprt, xprt->reestablish_timeout / HZ);
2256                 queue_delayed_work(rpciod_workqueue,
2257                                    &transport->connect_worker,
2258                                    xprt->reestablish_timeout);
2259                 xprt->reestablish_timeout <<= 1;
2260                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2261                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2262                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2263                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2264         } else {
2265                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2266                 queue_delayed_work(rpciod_workqueue,
2267                                    &transport->connect_worker, 0);
2268         }
2269 }
2270
2271 /**
2272  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2273  * @xprt: rpc_xprt struct containing statistics
2274  * @seq: output file
2275  *
2276  */
2277 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2278 {
2279         long idle_time = 0;
2280
2281         if (xprt_connected(xprt))
2282                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2283
2284         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2285                         "%llu %llu %lu %llu %llu\n",
2286                         xprt->stat.bind_count,
2287                         xprt->stat.connect_count,
2288                         xprt->stat.connect_time,
2289                         idle_time,
2290                         xprt->stat.sends,
2291                         xprt->stat.recvs,
2292                         xprt->stat.bad_xids,
2293                         xprt->stat.req_u,
2294                         xprt->stat.bklog_u,
2295                         xprt->stat.max_slots,
2296                         xprt->stat.sending_u,
2297                         xprt->stat.pending_u);
2298 }
2299
2300 /**
2301  * xs_udp_print_stats - display UDP socket-specifc stats
2302  * @xprt: rpc_xprt struct containing statistics
2303  * @seq: output file
2304  *
2305  */
2306 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2307 {
2308         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2309
2310         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2311                         "%lu %llu %llu\n",
2312                         transport->srcport,
2313                         xprt->stat.bind_count,
2314                         xprt->stat.sends,
2315                         xprt->stat.recvs,
2316                         xprt->stat.bad_xids,
2317                         xprt->stat.req_u,
2318                         xprt->stat.bklog_u,
2319                         xprt->stat.max_slots,
2320                         xprt->stat.sending_u,
2321                         xprt->stat.pending_u);
2322 }
2323
2324 /**
2325  * xs_tcp_print_stats - display TCP socket-specifc stats
2326  * @xprt: rpc_xprt struct containing statistics
2327  * @seq: output file
2328  *
2329  */
2330 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2331 {
2332         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2333         long idle_time = 0;
2334
2335         if (xprt_connected(xprt))
2336                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2337
2338         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2339                         "%llu %llu %lu %llu %llu\n",
2340                         transport->srcport,
2341                         xprt->stat.bind_count,
2342                         xprt->stat.connect_count,
2343                         xprt->stat.connect_time,
2344                         idle_time,
2345                         xprt->stat.sends,
2346                         xprt->stat.recvs,
2347                         xprt->stat.bad_xids,
2348                         xprt->stat.req_u,
2349                         xprt->stat.bklog_u,
2350                         xprt->stat.max_slots,
2351                         xprt->stat.sending_u,
2352                         xprt->stat.pending_u);
2353 }
2354
2355 /*
2356  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2357  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2358  * to use the server side send routines.
2359  */
2360 static void *bc_malloc(struct rpc_task *task, size_t size)
2361 {
2362         struct page *page;
2363         struct rpc_buffer *buf;
2364
2365         WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2366         if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2367                 return NULL;
2368
2369         page = alloc_page(GFP_KERNEL);
2370         if (!page)
2371                 return NULL;
2372
2373         buf = page_address(page);
2374         buf->len = PAGE_SIZE;
2375
2376         return buf->data;
2377 }
2378
2379 /*
2380  * Free the space allocated in the bc_alloc routine
2381  */
2382 static void bc_free(void *buffer)
2383 {
2384         struct rpc_buffer *buf;
2385
2386         if (!buffer)
2387                 return;
2388
2389         buf = container_of(buffer, struct rpc_buffer, data);
2390         free_page((unsigned long)buf);
2391 }
2392
2393 /*
2394  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2395  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2396  */
2397 static int bc_sendto(struct rpc_rqst *req)
2398 {
2399         int len;
2400         struct xdr_buf *xbufp = &req->rq_snd_buf;
2401         struct rpc_xprt *xprt = req->rq_xprt;
2402         struct sock_xprt *transport =
2403                                 container_of(xprt, struct sock_xprt, xprt);
2404         struct socket *sock = transport->sock;
2405         unsigned long headoff;
2406         unsigned long tailoff;
2407
2408         xs_encode_stream_record_marker(xbufp);
2409
2410         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2411         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2412         len = svc_send_common(sock, xbufp,
2413                               virt_to_page(xbufp->head[0].iov_base), headoff,
2414                               xbufp->tail[0].iov_base, tailoff);
2415
2416         if (len != xbufp->len) {
2417                 printk(KERN_NOTICE "Error sending entire callback!\n");
2418                 len = -EAGAIN;
2419         }
2420
2421         return len;
2422 }
2423
2424 /*
2425  * The send routine. Borrows from svc_send
2426  */
2427 static int bc_send_request(struct rpc_task *task)
2428 {
2429         struct rpc_rqst *req = task->tk_rqstp;
2430         struct svc_xprt *xprt;
2431         u32                     len;
2432
2433         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2434         /*
2435          * Get the server socket associated with this callback xprt
2436          */
2437         xprt = req->rq_xprt->bc_xprt;
2438
2439         /*
2440          * Grab the mutex to serialize data as the connection is shared
2441          * with the fore channel
2442          */
2443         if (!mutex_trylock(&xprt->xpt_mutex)) {
2444                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2445                 if (!mutex_trylock(&xprt->xpt_mutex))
2446                         return -EAGAIN;
2447                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2448         }
2449         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2450                 len = -ENOTCONN;
2451         else
2452                 len = bc_sendto(req);
2453         mutex_unlock(&xprt->xpt_mutex);
2454
2455         if (len > 0)
2456                 len = 0;
2457
2458         return len;
2459 }
2460
2461 /*
2462  * The close routine. Since this is client initiated, we do nothing
2463  */
2464
2465 static void bc_close(struct rpc_xprt *xprt)
2466 {
2467 }
2468
2469 /*
2470  * The xprt destroy routine. Again, because this connection is client
2471  * initiated, we do nothing
2472  */
2473
2474 static void bc_destroy(struct rpc_xprt *xprt)
2475 {
2476 }
2477
2478 static struct rpc_xprt_ops xs_local_ops = {
2479         .reserve_xprt           = xprt_reserve_xprt,
2480         .release_xprt           = xs_tcp_release_xprt,
2481         .alloc_slot             = xprt_alloc_slot,
2482         .rpcbind                = xs_local_rpcbind,
2483         .set_port               = xs_local_set_port,
2484         .connect                = xs_local_connect,
2485         .buf_alloc              = rpc_malloc,
2486         .buf_free               = rpc_free,
2487         .send_request           = xs_local_send_request,
2488         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2489         .close                  = xs_close,
2490         .destroy                = xs_local_destroy,
2491         .print_stats            = xs_local_print_stats,
2492 };
2493
2494 static struct rpc_xprt_ops xs_udp_ops = {
2495         .set_buffer_size        = xs_udp_set_buffer_size,
2496         .reserve_xprt           = xprt_reserve_xprt_cong,
2497         .release_xprt           = xprt_release_xprt_cong,
2498         .alloc_slot             = xprt_alloc_slot,
2499         .rpcbind                = rpcb_getport_async,
2500         .set_port               = xs_set_port,
2501         .connect                = xs_connect,
2502         .buf_alloc              = rpc_malloc,
2503         .buf_free               = rpc_free,
2504         .send_request           = xs_udp_send_request,
2505         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2506         .timer                  = xs_udp_timer,
2507         .release_request        = xprt_release_rqst_cong,
2508         .close                  = xs_close,
2509         .destroy                = xs_destroy,
2510         .print_stats            = xs_udp_print_stats,
2511 };
2512
2513 static struct rpc_xprt_ops xs_tcp_ops = {
2514         .reserve_xprt           = xprt_reserve_xprt,
2515         .release_xprt           = xs_tcp_release_xprt,
2516         .alloc_slot             = xprt_lock_and_alloc_slot,
2517         .rpcbind                = rpcb_getport_async,
2518         .set_port               = xs_set_port,
2519         .connect                = xs_connect,
2520         .buf_alloc              = rpc_malloc,
2521         .buf_free               = rpc_free,
2522         .send_request           = xs_tcp_send_request,
2523         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2524         .close                  = xs_tcp_close,
2525         .destroy                = xs_destroy,
2526         .print_stats            = xs_tcp_print_stats,
2527 };
2528
2529 /*
2530  * The rpc_xprt_ops for the server backchannel
2531  */
2532
2533 static struct rpc_xprt_ops bc_tcp_ops = {
2534         .reserve_xprt           = xprt_reserve_xprt,
2535         .release_xprt           = xprt_release_xprt,
2536         .alloc_slot             = xprt_alloc_slot,
2537         .buf_alloc              = bc_malloc,
2538         .buf_free               = bc_free,
2539         .send_request           = bc_send_request,
2540         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2541         .close                  = bc_close,
2542         .destroy                = bc_destroy,
2543         .print_stats            = xs_tcp_print_stats,
2544 };
2545
2546 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2547 {
2548         static const struct sockaddr_in sin = {
2549                 .sin_family             = AF_INET,
2550                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2551         };
2552         static const struct sockaddr_in6 sin6 = {
2553                 .sin6_family            = AF_INET6,
2554                 .sin6_addr              = IN6ADDR_ANY_INIT,
2555         };
2556
2557         switch (family) {
2558         case AF_LOCAL:
2559                 break;
2560         case AF_INET:
2561                 memcpy(sap, &sin, sizeof(sin));
2562                 break;
2563         case AF_INET6:
2564                 memcpy(sap, &sin6, sizeof(sin6));
2565                 break;
2566         default:
2567                 dprintk("RPC:       %s: Bad address family\n", __func__);
2568                 return -EAFNOSUPPORT;
2569         }
2570         return 0;
2571 }
2572
2573 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2574                                       unsigned int slot_table_size,
2575                                       unsigned int max_slot_table_size)
2576 {
2577         struct rpc_xprt *xprt;
2578         struct sock_xprt *new;
2579
2580         if (args->addrlen > sizeof(xprt->addr)) {
2581                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2582                 return ERR_PTR(-EBADF);
2583         }
2584
2585         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2586                         max_slot_table_size);
2587         if (xprt == NULL) {
2588                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2589                                 "rpc_xprt\n");
2590                 return ERR_PTR(-ENOMEM);
2591         }
2592
2593         new = container_of(xprt, struct sock_xprt, xprt);
2594         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2595         xprt->addrlen = args->addrlen;
2596         if (args->srcaddr)
2597                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2598         else {
2599                 int err;
2600                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2601                                         (struct sockaddr *)&new->srcaddr);
2602                 if (err != 0) {
2603                         xprt_free(xprt);
2604                         return ERR_PTR(err);
2605                 }
2606         }
2607
2608         return xprt;
2609 }
2610
2611 static const struct rpc_timeout xs_local_default_timeout = {
2612         .to_initval = 10 * HZ,
2613         .to_maxval = 10 * HZ,
2614         .to_retries = 2,
2615 };
2616
2617 /**
2618  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2619  * @args: rpc transport creation arguments
2620  *
2621  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2622  */
2623 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2624 {
2625         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2626         struct sock_xprt *transport;
2627         struct rpc_xprt *xprt;
2628         struct rpc_xprt *ret;
2629
2630         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2631                         xprt_max_tcp_slot_table_entries);
2632         if (IS_ERR(xprt))
2633                 return xprt;
2634         transport = container_of(xprt, struct sock_xprt, xprt);
2635
2636         xprt->prot = 0;
2637         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2638         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2639
2640         xprt->bind_timeout = XS_BIND_TO;
2641         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2642         xprt->idle_timeout = XS_IDLE_DISC_TO;
2643
2644         xprt->ops = &xs_local_ops;
2645         xprt->timeout = &xs_local_default_timeout;
2646
2647         switch (sun->sun_family) {
2648         case AF_LOCAL:
2649                 if (sun->sun_path[0] != '/') {
2650                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2651                                         sun->sun_path);
2652                         ret = ERR_PTR(-EINVAL);
2653                         goto out_err;
2654                 }
2655                 xprt_set_bound(xprt);
2656                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2657                 ret = ERR_PTR(xs_local_setup_socket(transport));
2658                 if (ret)
2659                         goto out_err;
2660                 break;
2661         default:
2662                 ret = ERR_PTR(-EAFNOSUPPORT);
2663                 goto out_err;
2664         }
2665
2666         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2667                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2668
2669         if (try_module_get(THIS_MODULE))
2670                 return xprt;
2671         ret = ERR_PTR(-EINVAL);
2672 out_err:
2673         xprt_free(xprt);
2674         return ret;
2675 }
2676
2677 static const struct rpc_timeout xs_udp_default_timeout = {
2678         .to_initval = 5 * HZ,
2679         .to_maxval = 30 * HZ,
2680         .to_increment = 5 * HZ,
2681         .to_retries = 5,
2682 };
2683
2684 /**
2685  * xs_setup_udp - Set up transport to use a UDP socket
2686  * @args: rpc transport creation arguments
2687  *
2688  */
2689 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2690 {
2691         struct sockaddr *addr = args->dstaddr;
2692         struct rpc_xprt *xprt;
2693         struct sock_xprt *transport;
2694         struct rpc_xprt *ret;
2695
2696         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2697                         xprt_udp_slot_table_entries);
2698         if (IS_ERR(xprt))
2699                 return xprt;
2700         transport = container_of(xprt, struct sock_xprt, xprt);
2701
2702         xprt->prot = IPPROTO_UDP;
2703         xprt->tsh_size = 0;
2704         /* XXX: header size can vary due to auth type, IPv6, etc. */
2705         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2706
2707         xprt->bind_timeout = XS_BIND_TO;
2708         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2709         xprt->idle_timeout = XS_IDLE_DISC_TO;
2710
2711         xprt->ops = &xs_udp_ops;
2712
2713         xprt->timeout = &xs_udp_default_timeout;
2714
2715         switch (addr->sa_family) {
2716         case AF_INET:
2717                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2718                         xprt_set_bound(xprt);
2719
2720                 INIT_DELAYED_WORK(&transport->connect_worker,
2721                                         xs_udp_setup_socket);
2722                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2723                 break;
2724         case AF_INET6:
2725                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2726                         xprt_set_bound(xprt);
2727
2728                 INIT_DELAYED_WORK(&transport->connect_worker,
2729                                         xs_udp_setup_socket);
2730                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2731                 break;
2732         default:
2733                 ret = ERR_PTR(-EAFNOSUPPORT);
2734                 goto out_err;
2735         }
2736
2737         if (xprt_bound(xprt))
2738                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2739                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2740                                 xprt->address_strings[RPC_DISPLAY_PORT],
2741                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2742         else
2743                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2744                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2745                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2746
2747         if (try_module_get(THIS_MODULE))
2748                 return xprt;
2749         ret = ERR_PTR(-EINVAL);
2750 out_err:
2751         xprt_free(xprt);
2752         return ret;
2753 }
2754
2755 static const struct rpc_timeout xs_tcp_default_timeout = {
2756         .to_initval = 60 * HZ,
2757         .to_maxval = 60 * HZ,
2758         .to_retries = 2,
2759 };
2760
2761 /**
2762  * xs_setup_tcp - Set up transport to use a TCP socket
2763  * @args: rpc transport creation arguments
2764  *
2765  */
2766 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2767 {
2768         struct sockaddr *addr = args->dstaddr;
2769         struct rpc_xprt *xprt;
2770         struct sock_xprt *transport;
2771         struct rpc_xprt *ret;
2772         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2773
2774         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2775                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2776
2777         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2778                         max_slot_table_size);
2779         if (IS_ERR(xprt))
2780                 return xprt;
2781         transport = container_of(xprt, struct sock_xprt, xprt);
2782
2783         xprt->prot = IPPROTO_TCP;
2784         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2785         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2786
2787         xprt->bind_timeout = XS_BIND_TO;
2788         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2789         xprt->idle_timeout = XS_IDLE_DISC_TO;
2790
2791         xprt->ops = &xs_tcp_ops;
2792         xprt->timeout = &xs_tcp_default_timeout;
2793
2794         switch (addr->sa_family) {
2795         case AF_INET:
2796                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2797                         xprt_set_bound(xprt);
2798
2799                 INIT_DELAYED_WORK(&transport->connect_worker,
2800                                         xs_tcp_setup_socket);
2801                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2802                 break;
2803         case AF_INET6:
2804                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2805                         xprt_set_bound(xprt);
2806
2807                 INIT_DELAYED_WORK(&transport->connect_worker,
2808                                         xs_tcp_setup_socket);
2809                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2810                 break;
2811         default:
2812                 ret = ERR_PTR(-EAFNOSUPPORT);
2813                 goto out_err;
2814         }
2815
2816         if (xprt_bound(xprt))
2817                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2818                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2819                                 xprt->address_strings[RPC_DISPLAY_PORT],
2820                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2821         else
2822                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2823                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2824                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2825
2826
2827         if (try_module_get(THIS_MODULE))
2828                 return xprt;
2829         ret = ERR_PTR(-EINVAL);
2830 out_err:
2831         xprt_free(xprt);
2832         return ret;
2833 }
2834
2835 /**
2836  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2837  * @args: rpc transport creation arguments
2838  *
2839  */
2840 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2841 {
2842         struct sockaddr *addr = args->dstaddr;
2843         struct rpc_xprt *xprt;
2844         struct sock_xprt *transport;
2845         struct svc_sock *bc_sock;
2846         struct rpc_xprt *ret;
2847
2848         if (args->bc_xprt->xpt_bc_xprt) {
2849                 /*
2850                  * This server connection already has a backchannel
2851                  * export; we can't create a new one, as we wouldn't be
2852                  * able to match replies based on xid any more.  So,
2853                  * reuse the already-existing one:
2854                  */
2855                  return args->bc_xprt->xpt_bc_xprt;
2856         }
2857         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2858                         xprt_tcp_slot_table_entries);
2859         if (IS_ERR(xprt))
2860                 return xprt;
2861         transport = container_of(xprt, struct sock_xprt, xprt);
2862
2863         xprt->prot = IPPROTO_TCP;
2864         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2865         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2866         xprt->timeout = &xs_tcp_default_timeout;
2867
2868         /* backchannel */
2869         xprt_set_bound(xprt);
2870         xprt->bind_timeout = 0;
2871         xprt->reestablish_timeout = 0;
2872         xprt->idle_timeout = 0;
2873
2874         xprt->ops = &bc_tcp_ops;
2875
2876         switch (addr->sa_family) {
2877         case AF_INET:
2878                 xs_format_peer_addresses(xprt, "tcp",
2879                                          RPCBIND_NETID_TCP);
2880                 break;
2881         case AF_INET6:
2882                 xs_format_peer_addresses(xprt, "tcp",
2883                                    RPCBIND_NETID_TCP6);
2884                 break;
2885         default:
2886                 ret = ERR_PTR(-EAFNOSUPPORT);
2887                 goto out_err;
2888         }
2889
2890         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2891                         xprt->address_strings[RPC_DISPLAY_ADDR],
2892                         xprt->address_strings[RPC_DISPLAY_PORT],
2893                         xprt->address_strings[RPC_DISPLAY_PROTO]);
2894
2895         /*
2896          * Once we've associated a backchannel xprt with a connection,
2897          * we want to keep it around as long as long as the connection
2898          * lasts, in case we need to start using it for a backchannel
2899          * again; this reference won't be dropped until bc_xprt is
2900          * destroyed.
2901          */
2902         xprt_get(xprt);
2903         args->bc_xprt->xpt_bc_xprt = xprt;
2904         xprt->bc_xprt = args->bc_xprt;
2905         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2906         transport->sock = bc_sock->sk_sock;
2907         transport->inet = bc_sock->sk_sk;
2908
2909         /*
2910          * Since we don't want connections for the backchannel, we set
2911          * the xprt status to connected
2912          */
2913         xprt_set_connected(xprt);
2914
2915
2916         if (try_module_get(THIS_MODULE))
2917                 return xprt;
2918         xprt_put(xprt);
2919         ret = ERR_PTR(-EINVAL);
2920 out_err:
2921         xprt_free(xprt);
2922         return ret;
2923 }
2924
2925 static struct xprt_class        xs_local_transport = {
2926         .list           = LIST_HEAD_INIT(xs_local_transport.list),
2927         .name           = "named UNIX socket",
2928         .owner          = THIS_MODULE,
2929         .ident          = XPRT_TRANSPORT_LOCAL,
2930         .setup          = xs_setup_local,
2931 };
2932
2933 static struct xprt_class        xs_udp_transport = {
2934         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
2935         .name           = "udp",
2936         .owner          = THIS_MODULE,
2937         .ident          = XPRT_TRANSPORT_UDP,
2938         .setup          = xs_setup_udp,
2939 };
2940
2941 static struct xprt_class        xs_tcp_transport = {
2942         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
2943         .name           = "tcp",
2944         .owner          = THIS_MODULE,
2945         .ident          = XPRT_TRANSPORT_TCP,
2946         .setup          = xs_setup_tcp,
2947 };
2948
2949 static struct xprt_class        xs_bc_tcp_transport = {
2950         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2951         .name           = "tcp NFSv4.1 backchannel",
2952         .owner          = THIS_MODULE,
2953         .ident          = XPRT_TRANSPORT_BC_TCP,
2954         .setup          = xs_setup_bc_tcp,
2955 };
2956
2957 /**
2958  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2959  *
2960  */
2961 int init_socket_xprt(void)
2962 {
2963 #ifdef RPC_DEBUG
2964         if (!sunrpc_table_header)
2965                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
2966 #endif
2967
2968         xprt_register_transport(&xs_local_transport);
2969         xprt_register_transport(&xs_udp_transport);
2970         xprt_register_transport(&xs_tcp_transport);
2971         xprt_register_transport(&xs_bc_tcp_transport);
2972
2973         return 0;
2974 }
2975
2976 /**
2977  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2978  *
2979  */
2980 void cleanup_socket_xprt(void)
2981 {
2982 #ifdef RPC_DEBUG
2983         if (sunrpc_table_header) {
2984                 unregister_sysctl_table(sunrpc_table_header);
2985                 sunrpc_table_header = NULL;
2986         }
2987 #endif
2988
2989         xprt_unregister_transport(&xs_local_transport);
2990         xprt_unregister_transport(&xs_udp_transport);
2991         xprt_unregister_transport(&xs_tcp_transport);
2992         xprt_unregister_transport(&xs_bc_tcp_transport);
2993 }
2994
2995 static int param_set_uint_minmax(const char *val,
2996                 const struct kernel_param *kp,
2997                 unsigned int min, unsigned int max)
2998 {
2999         unsigned long num;
3000         int ret;
3001
3002         if (!val)
3003                 return -EINVAL;
3004         ret = strict_strtoul(val, 0, &num);
3005         if (ret == -EINVAL || num < min || num > max)
3006                 return -EINVAL;
3007         *((unsigned int *)kp->arg) = num;
3008         return 0;
3009 }
3010
3011 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3012 {
3013         return param_set_uint_minmax(val, kp,
3014                         RPC_MIN_RESVPORT,
3015                         RPC_MAX_RESVPORT);
3016 }
3017
3018 static struct kernel_param_ops param_ops_portnr = {
3019         .set = param_set_portnr,
3020         .get = param_get_uint,
3021 };
3022
3023 #define param_check_portnr(name, p) \
3024         __param_check(name, p, unsigned int);
3025
3026 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3027 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3028
3029 static int param_set_slot_table_size(const char *val,
3030                                      const struct kernel_param *kp)
3031 {
3032         return param_set_uint_minmax(val, kp,
3033                         RPC_MIN_SLOT_TABLE,
3034                         RPC_MAX_SLOT_TABLE);
3035 }
3036
3037 static struct kernel_param_ops param_ops_slot_table_size = {
3038         .set = param_set_slot_table_size,
3039         .get = param_get_uint,
3040 };
3041
3042 #define param_check_slot_table_size(name, p) \
3043         __param_check(name, p, unsigned int);
3044
3045 static int param_set_max_slot_table_size(const char *val,
3046                                      const struct kernel_param *kp)
3047 {
3048         return param_set_uint_minmax(val, kp,
3049                         RPC_MIN_SLOT_TABLE,
3050                         RPC_MAX_SLOT_TABLE_LIMIT);
3051 }
3052
3053 static struct kernel_param_ops param_ops_max_slot_table_size = {
3054         .set = param_set_max_slot_table_size,
3055         .get = param_get_uint,
3056 };
3057
3058 #define param_check_max_slot_table_size(name, p) \
3059         __param_check(name, p, unsigned int);
3060
3061 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3062                    slot_table_size, 0644);
3063 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3064                    max_slot_table_size, 0644);
3065 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3066                    slot_table_size, 0644);
3067