net/sunrpc/xprtsock.c

   1 /*
   2  * linux/net/sunrpc/xprtsock.c
   3  *
   4  * Client-side transport implementation for sockets.
   5  *
   6  * TCP callback races fixes (C) 1998 Red Hat
   7  * TCP send fixes (C) 1998 Red Hat
   8  * TCP NFS related read + write fixes
   9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
  10  *
  11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
  12  * Fix behaviour when socket buffer is full.
  13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  14  *
  15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
  16  *
  17  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
  18  *   <gilles.quillard@bull.net>
  19  */
  20
  21 #include <linux/types.h>
  22 #include <linux/string.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/capability.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/errno.h>
  28 #include <linux/socket.h>
  29 #include <linux/in.h>
  30 #include <linux/net.h>
  31 #include <linux/mm.h>
  32 #include <linux/un.h>
  33 #include <linux/udp.h>
  34 #include <linux/tcp.h>
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/sched.h>
  38 #include <linux/sunrpc/svcsock.h>
  39 #include <linux/sunrpc/xprtsock.h>
  40 #include <linux/file.h>
  41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
  42 #include <linux/sunrpc/bc_xprt.h>
  43 #endif
  44
  45 #include <net/sock.h>
  46 #include <net/checksum.h>
  47 #include <net/udp.h>
  48 #include <net/tcp.h>
  49
  50 #include <trace/events/sunrpc.h>
  51
  52 #include "sunrpc.h"
  53
  54 static void xs_close(struct rpc_xprt *xprt);
  55 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
  56                 struct socket *sock);
  57
  58 /*
  59  * xprtsock tunables
  60  */
  61 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  62 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
  63 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
  64
  65 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  66 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  67
  68 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  69
  70 #define XS_TCP_LINGER_TO        (15U * HZ)
  71 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  72
  73 /*
  74  * We can register our own files under /proc/sys/sunrpc by
  75  * calling register_sysctl_table() again.  The files in that
  76  * directory become the union of all files registered there.
  77  *
  78  * We simply need to make sure that we don't collide with
  79  * someone else's file names!
  80  */
  81
  82 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  83 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  84 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
  85 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  86 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  87
  88 static struct ctl_table_header *sunrpc_table_header;
  89
  90 /*
  91  * FIXME: changing the UDP slot table size should also resize the UDP
  92  *        socket buffers for existing UDP transports
  93  */
  94 static struct ctl_table xs_tunables_table[] = {
  95         {
  96                 .procname       = "udp_slot_table_entries",
  97                 .data           = &xprt_udp_slot_table_entries,
  98                 .maxlen         = sizeof(unsigned int),
  99                 .mode           = 0644,
 100                 .proc_handler   = proc_dointvec_minmax,
 101                 .extra1         = &min_slot_table_size,
 102                 .extra2         = &max_slot_table_size
 103         },
 104         {
 105                 .procname       = "tcp_slot_table_entries",
 106                 .data           = &xprt_tcp_slot_table_entries,
 107                 .maxlen         = sizeof(unsigned int),
 108                 .mode           = 0644,
 109                 .proc_handler   = proc_dointvec_minmax,
 110                 .extra1         = &min_slot_table_size,
 111                 .extra2         = &max_slot_table_size
 112         },
 113         {
 114                 .procname       = "tcp_max_slot_table_entries",
 115                 .data           = &xprt_max_tcp_slot_table_entries,
 116                 .maxlen         = sizeof(unsigned int),
 117                 .mode           = 0644,
 118                 .proc_handler   = proc_dointvec_minmax,
 119                 .extra1         = &min_slot_table_size,
 120                 .extra2         = &max_tcp_slot_table_limit
 121         },
 122         {
 123                 .procname       = "min_resvport",
 124                 .data           = &xprt_min_resvport,
 125                 .maxlen         = sizeof(unsigned int),
 126                 .mode           = 0644,
 127                 .proc_handler   = proc_dointvec_minmax,
 128                 .extra1         = &xprt_min_resvport_limit,
 129                 .extra2         = &xprt_max_resvport
 130         },
 131         {
 132                 .procname       = "max_resvport",
 133                 .data           = &xprt_max_resvport,
 134                 .maxlen         = sizeof(unsigned int),
 135                 .mode           = 0644,
 136                 .proc_handler   = proc_dointvec_minmax,
 137                 .extra1         = &xprt_min_resvport,
 138                 .extra2         = &xprt_max_resvport_limit
 139         },
 140         {
 141                 .procname       = "tcp_fin_timeout",
 142                 .data           = &xs_tcp_fin_timeout,
 143                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 144                 .mode           = 0644,
 145                 .proc_handler   = proc_dointvec_jiffies,
 146         },
 147         { },
 148 };
 149
 150 static struct ctl_table sunrpc_table[] = {
 151         {
 152                 .procname       = "sunrpc",
 153                 .mode           = 0555,
 154                 .child          = xs_tunables_table
 155         },
 156         { },
 157 };
 158
 159 #endif
 160
 161 /*
 162  * Wait duration for a reply from the RPC portmapper.
 163  */
 164 #define XS_BIND_TO              (60U * HZ)
 165
 166 /*
 167  * Delay if a UDP socket connect error occurs.  This is most likely some
 168  * kind of resource problem on the local host.
 169  */
 170 #define XS_UDP_REEST_TO         (2U * HZ)
 171
 172 /*
 173  * The reestablish timeout allows clients to delay for a bit before attempting
 174  * to reconnect to a server that just dropped our connection.
 175  *
 176  * We implement an exponential backoff when trying to reestablish a TCP
 177  * transport connection with the server.  Some servers like to drop a TCP
 178  * connection when they are overworked, so we start with a short timeout and
 179  * increase over time if the server is down or not responding.
 180  */
 181 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 182
 183 /*
 184  * TCP idle timeout; client drops the transport socket if it is idle
 185  * for this long.  Note that we also timeout UDP sockets to prevent
 186  * holding port numbers when there is no RPC traffic.
 187  */
 188 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 189
 190 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 191 # undef  RPC_DEBUG_DATA
 192 # define RPCDBG_FACILITY        RPCDBG_TRANS
 193 #endif
 194
 195 #ifdef RPC_DEBUG_DATA
 196 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 197 {
 198         u8 *buf = (u8 *) packet;
 199         int j;
 200
 201         dprintk("RPC:       %s\n", msg);
 202         for (j = 0; j < count && j < 128; j += 4) {
 203                 if (!(j & 31)) {
 204                         if (j)
 205                                 dprintk("\n");
 206                         dprintk("0x%04x ", j);
 207                 }
 208                 dprintk("%02x%02x%02x%02x ",
 209                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 210         }
 211         dprintk("\n");
 212 }
 213 #else
 214 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 215 {
 216         /* NOP */
 217 }
 218 #endif
 219
 220 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 221 {
 222         return (struct rpc_xprt *) sk->sk_user_data;
 223 }
 224
 225 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 226 {
 227         return (struct sockaddr *) &xprt->addr;
 228 }
 229
 230 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
 231 {
 232         return (struct sockaddr_un *) &xprt->addr;
 233 }
 234
 235 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 236 {
 237         return (struct sockaddr_in *) &xprt->addr;
 238 }
 239
 240 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 241 {
 242         return (struct sockaddr_in6 *) &xprt->addr;
 243 }
 244
 245 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 246 {
 247         struct sockaddr *sap = xs_addr(xprt);
 248         struct sockaddr_in6 *sin6;
 249         struct sockaddr_in *sin;
 250         struct sockaddr_un *sun;
 251         char buf[128];
 252
 253         switch (sap->sa_family) {
 254         case AF_LOCAL:
 255                 sun = xs_addr_un(xprt);
 256                 strlcpy(buf, sun->sun_path, sizeof(buf));
 257                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 258                                                 kstrdup(buf, GFP_KERNEL);
 259                 break;
 260         case AF_INET:
 261                 (void)rpc_ntop(sap, buf, sizeof(buf));
 262                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 263                                                 kstrdup(buf, GFP_KERNEL);
 264                 sin = xs_addr_in(xprt);
 265                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 266                 break;
 267         case AF_INET6:
 268                 (void)rpc_ntop(sap, buf, sizeof(buf));
 269                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 270                                                 kstrdup(buf, GFP_KERNEL);
 271                 sin6 = xs_addr_in6(xprt);
 272                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 273                 break;
 274         default:
 275                 BUG();
 276         }
 277
 278         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 279 }
 280
 281 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 282 {
 283         struct sockaddr *sap = xs_addr(xprt);
 284         char buf[128];
 285
 286         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 287         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 288
 289         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 290         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 291 }
 292
 293 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 294                                      const char *protocol,
 295                                      const char *netid)
 296 {
 297         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 298         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 299         xs_format_common_peer_addresses(xprt);
 300         xs_format_common_peer_ports(xprt);
 301 }
 302
 303 static void xs_update_peer_port(struct rpc_xprt *xprt)
 304 {
 305         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 306         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 307
 308         xs_format_common_peer_ports(xprt);
 309 }
 310
 311 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 312 {
 313         unsigned int i;
 314
 315         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 316                 switch (i) {
 317                 case RPC_DISPLAY_PROTO:
 318                 case RPC_DISPLAY_NETID:
 319                         continue;
 320                 default:
 321                         kfree(xprt->address_strings[i]);
 322                 }
 323 }
 324
 325 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 326
 327 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
 328 {
 329         struct msghdr msg = {
 330                 .msg_name       = addr,
 331                 .msg_namelen    = addrlen,
 332                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
 333         };
 334         struct kvec iov = {
 335                 .iov_base       = vec->iov_base + base,
 336                 .iov_len        = vec->iov_len - base,
 337         };
 338
 339         if (iov.iov_len != 0)
 340                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 341         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 342 }
 343
 344 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
 345 {
 346         ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
 347                         int offset, size_t size, int flags);
 348         struct page **ppage;
 349         unsigned int remainder;
 350         int err;
 351
 352         remainder = xdr->page_len - base;
 353         base += xdr->page_base;
 354         ppage = xdr->pages + (base >> PAGE_SHIFT);
 355         base &= ~PAGE_MASK;
 356         do_sendpage = sock->ops->sendpage;
 357         if (!zerocopy)
 358                 do_sendpage = sock_no_sendpage;
 359         for(;;) {
 360                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
 361                 int flags = XS_SENDMSG_FLAGS;
 362
 363                 remainder -= len;
 364                 if (more)
 365                         flags |= MSG_MORE;
 366                 if (remainder != 0)
 367                         flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
 368                 err = do_sendpage(sock, *ppage, base, len, flags);
 369                 if (remainder == 0 || err != len)
 370                         break;
 371                 *sent_p += err;
 372                 ppage++;
 373                 base = 0;
 374         }
 375         if (err > 0) {
 376                 *sent_p += err;
 377                 err = 0;
 378         }
 379         return err;
 380 }
 381
 382 /**
 383  * xs_sendpages - write pages directly to a socket
 384  * @sock: socket to send on
 385  * @addr: UDP only -- address of destination
 386  * @addrlen: UDP only -- length of destination address
 387  * @xdr: buffer containing this request
 388  * @base: starting position in the buffer
 389  * @zerocopy: true if it is safe to use sendpage()
 390  * @sent_p: return the total number of bytes successfully queued for sending
 391  *
 392  */
 393 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
 394 {
 395         unsigned int remainder = xdr->len - base;
 396         int err = 0;
 397         int sent = 0;
 398
 399         if (unlikely(!sock))
 400                 return -ENOTSOCK;
 401
 402         if (base != 0) {
 403                 addr = NULL;
 404                 addrlen = 0;
 405         }
 406
 407         if (base < xdr->head[0].iov_len || addr != NULL) {
 408                 unsigned int len = xdr->head[0].iov_len - base;
 409                 remainder -= len;
 410                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
 411                 if (remainder == 0 || err != len)
 412                         goto out;
 413                 *sent_p += err;
 414                 base = 0;
 415         } else
 416                 base -= xdr->head[0].iov_len;
 417
 418         if (base < xdr->page_len) {
 419                 unsigned int len = xdr->page_len - base;
 420                 remainder -= len;
 421                 err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
 422                 *sent_p += sent;
 423                 if (remainder == 0 || sent != len)
 424                         goto out;
 425                 base = 0;
 426         } else
 427                 base -= xdr->page_len;
 428
 429         if (base >= xdr->tail[0].iov_len)
 430                 return 0;
 431         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
 432 out:
 433         if (err > 0) {
 434                 *sent_p += err;
 435                 err = 0;
 436         }
 437         return err;
 438 }
 439
 440 static void xs_nospace_callback(struct rpc_task *task)
 441 {
 442         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 443
 444         transport->inet->sk_write_pending--;
 445 }
 446
 447 /**
 448  * xs_nospace - place task on wait queue if transmit was incomplete
 449  * @task: task to put to sleep
 450  *
 451  */
 452 static int xs_nospace(struct rpc_task *task)
 453 {
 454         struct rpc_rqst *req = task->tk_rqstp;
 455         struct rpc_xprt *xprt = req->rq_xprt;
 456         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 457         struct sock *sk = transport->inet;
 458         int ret = -EAGAIN;
 459
 460         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 461                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 462                         req->rq_slen);
 463
 464         /* Protect against races with write_space */
 465         spin_lock_bh(&xprt->transport_lock);
 466
 467         /* Don't race with disconnect */
 468         if (xprt_connected(xprt)) {
 469                 /* wait for more buffer space */
 470                 sk->sk_write_pending++;
 471                 xprt_wait_for_buffer_space(task, xs_nospace_callback);
 472         } else
 473                 ret = -ENOTCONN;
 474
 475         spin_unlock_bh(&xprt->transport_lock);
 476
 477         /* Race breaker in case memory is freed before above code is called */
 478         if (ret == -EAGAIN) {
 479                 struct socket_wq *wq;
 480
 481                 rcu_read_lock();
 482                 wq = rcu_dereference(sk->sk_wq);
 483                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
 484                 rcu_read_unlock();
 485
 486                 sk->sk_write_space(sk);
 487         }
 488         return ret;
 489 }
 490
 491 /*
 492  * Construct a stream transport record marker in @buf.
 493  */
 494 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
 495 {
 496         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 497         rpc_fraghdr *base = buf->head[0].iov_base;
 498         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
 499 }
 500
 501 /**
 502  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 503  * @task: RPC task that manages the state of an RPC request
 504  *
 505  * Return values:
 506  *        0:    The request has been sent
 507  *   EAGAIN:    The socket was blocked, please call again later to
 508  *              complete the request
 509  * ENOTCONN:    Caller needs to invoke connect logic then call again
 510  *    other:    Some other error occured, the request was not sent
 511  */
 512 static int xs_local_send_request(struct rpc_task *task)
 513 {
 514         struct rpc_rqst *req = task->tk_rqstp;
 515         struct rpc_xprt *xprt = req->rq_xprt;
 516         struct sock_xprt *transport =
 517                                 container_of(xprt, struct sock_xprt, xprt);
 518         struct xdr_buf *xdr = &req->rq_snd_buf;
 519         int status;
 520         int sent = 0;
 521
 522         xs_encode_stream_record_marker(&req->rq_snd_buf);
 523
 524         xs_pktdump("packet data:",
 525                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 526
 527         status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
 528                               true, &sent);
 529         dprintk("RPC:       %s(%u) = %d\n",
 530                         __func__, xdr->len - req->rq_bytes_sent, status);
 531
 532         if (status == -EAGAIN && sock_writeable(transport->inet))
 533                 status = -ENOBUFS;
 534
 535         if (likely(sent > 0) || status == 0) {
 536                 req->rq_bytes_sent += sent;
 537                 req->rq_xmit_bytes_sent += sent;
 538                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 539                         req->rq_bytes_sent = 0;
 540                         return 0;
 541                 }
 542                 status = -EAGAIN;
 543         }
 544
 545         switch (status) {
 546         case -ENOBUFS:
 547                 break;
 548         case -EAGAIN:
 549                 status = xs_nospace(task);
 550                 break;
 551         default:
 552                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 553                         -status);
 554         case -EPIPE:
 555                 xs_close(xprt);
 556                 status = -ENOTCONN;
 557         }
 558
 559         return status;
 560 }
 561
 562 /**
 563  * xs_udp_send_request - write an RPC request to a UDP socket
 564  * @task: address of RPC task that manages the state of an RPC request
 565  *
 566  * Return values:
 567  *        0:    The request has been sent
 568  *   EAGAIN:    The socket was blocked, please call again later to
 569  *              complete the request
 570  * ENOTCONN:    Caller needs to invoke connect logic then call again
 571  *    other:    Some other error occurred, the request was not sent
 572  */
 573 static int xs_udp_send_request(struct rpc_task *task)
 574 {
 575         struct rpc_rqst *req = task->tk_rqstp;
 576         struct rpc_xprt *xprt = req->rq_xprt;
 577         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 578         struct xdr_buf *xdr = &req->rq_snd_buf;
 579         int sent = 0;
 580         int status;
 581
 582         xs_pktdump("packet data:",
 583                                 req->rq_svec->iov_base,
 584                                 req->rq_svec->iov_len);
 585
 586         if (!xprt_bound(xprt))
 587                 return -ENOTCONN;
 588         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
 589                               xdr, req->rq_bytes_sent, true, &sent);
 590
 591         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 592                         xdr->len - req->rq_bytes_sent, status);
 593
 594         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
 595         if (status == -EPERM)
 596                 goto process_status;
 597
 598         if (status == -EAGAIN && sock_writeable(transport->inet))
 599                 status = -ENOBUFS;
 600
 601         if (sent > 0 || status == 0) {
 602                 req->rq_xmit_bytes_sent += sent;
 603                 if (sent >= req->rq_slen)
 604                         return 0;
 605                 /* Still some bytes left; set up for a retry later. */
 606                 status = -EAGAIN;
 607         }
 608
 609 process_status:
 610         switch (status) {
 611         case -ENOTSOCK:
 612                 status = -ENOTCONN;
 613                 /* Should we call xs_close() here? */
 614                 break;
 615         case -EAGAIN:
 616                 status = xs_nospace(task);
 617                 break;
 618         case -ENETUNREACH:
 619         case -ENOBUFS:
 620         case -EPIPE:
 621         case -ECONNREFUSED:
 622         case -EPERM:
 623                 /* When the server has died, an ICMP port unreachable message
 624                  * prompts ECONNREFUSED. */
 625                 break;
 626         default:
 627                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 628                         -status);
 629         }
 630
 631         return status;
 632 }
 633
 634 /**
 635  * xs_tcp_send_request - write an RPC request to a TCP socket
 636  * @task: address of RPC task that manages the state of an RPC request
 637  *
 638  * Return values:
 639  *        0:    The request has been sent
 640  *   EAGAIN:    The socket was blocked, please call again later to
 641  *              complete the request
 642  * ENOTCONN:    Caller needs to invoke connect logic then call again
 643  *    other:    Some other error occurred, the request was not sent
 644  *
 645  * XXX: In the case of soft timeouts, should we eventually give up
 646  *      if sendmsg is not able to make progress?
 647  */
 648 static int xs_tcp_send_request(struct rpc_task *task)
 649 {
 650         struct rpc_rqst *req = task->tk_rqstp;
 651         struct rpc_xprt *xprt = req->rq_xprt;
 652         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 653         struct xdr_buf *xdr = &req->rq_snd_buf;
 654         bool zerocopy = true;
 655         bool vm_wait = false;
 656         int status;
 657         int sent;
 658
 659         xs_encode_stream_record_marker(&req->rq_snd_buf);
 660
 661         xs_pktdump("packet data:",
 662                                 req->rq_svec->iov_base,
 663                                 req->rq_svec->iov_len);
 664         /* Don't use zero copy if this is a resend. If the RPC call
 665          * completes while the socket holds a reference to the pages,
 666          * then we may end up resending corrupted data.
 667          */
 668         if (task->tk_flags & RPC_TASK_SENT)
 669                 zerocopy = false;
 670
 671         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
 672                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
 673
 674         /* Continue transmitting the packet/record. We must be careful
 675          * to cope with writespace callbacks arriving _after_ we have
 676          * called sendmsg(). */
 677         while (1) {
 678                 sent = 0;
 679                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
 680                                       req->rq_bytes_sent, zerocopy, &sent);
 681
 682                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 683                                 xdr->len - req->rq_bytes_sent, status);
 684
 685                 /* If we've sent the entire packet, immediately
 686                  * reset the count of bytes sent. */
 687                 req->rq_bytes_sent += sent;
 688                 req->rq_xmit_bytes_sent += sent;
 689                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 690                         req->rq_bytes_sent = 0;
 691                         return 0;
 692                 }
 693
 694                 WARN_ON_ONCE(sent == 0 && status == 0);
 695
 696                 if (status == -EAGAIN ) {
 697                         /*
 698                          * Return EAGAIN if we're sure we're hitting the
 699                          * socket send buffer limits.
 700                          */
 701                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
 702                                 break;
 703                         /*
 704                          * Did we hit a memory allocation failure?
 705                          */
 706                         if (sent == 0) {
 707                                 status = -ENOBUFS;
 708                                 if (vm_wait)
 709                                         break;
 710                                 /* Retry, knowing now that we're below the
 711                                  * socket send buffer limit
 712                                  */
 713                                 vm_wait = true;
 714                         }
 715                         continue;
 716                 }
 717                 if (status < 0)
 718                         break;
 719                 vm_wait = false;
 720         }
 721
 722         switch (status) {
 723         case -ENOTSOCK:
 724                 status = -ENOTCONN;
 725                 /* Should we call xs_close() here? */
 726                 break;
 727         case -EAGAIN:
 728                 status = xs_nospace(task);
 729                 break;
 730         case -ECONNRESET:
 731         case -ECONNREFUSED:
 732         case -ENOTCONN:
 733         case -EADDRINUSE:
 734         case -ENOBUFS:
 735         case -EPIPE:
 736                 break;
 737         default:
 738                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 739                         -status);
 740         }
 741
 742         return status;
 743 }
 744
 745 /**
 746  * xs_tcp_release_xprt - clean up after a tcp transmission
 747  * @xprt: transport
 748  * @task: rpc task
 749  *
 750  * This cleans up if an error causes us to abort the transmission of a request.
 751  * In this case, the socket may need to be reset in order to avoid confusing
 752  * the server.
 753  */
 754 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 755 {
 756         struct rpc_rqst *req;
 757
 758         if (task != xprt->snd_task)
 759                 return;
 760         if (task == NULL)
 761                 goto out_release;
 762         req = task->tk_rqstp;
 763         if (req == NULL)
 764                 goto out_release;
 765         if (req->rq_bytes_sent == 0)
 766                 goto out_release;
 767         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 768                 goto out_release;
 769         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 770 out_release:
 771         xprt_release_xprt(xprt, task);
 772 }
 773
 774 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 775 {
 776         transport->old_data_ready = sk->sk_data_ready;
 777         transport->old_state_change = sk->sk_state_change;
 778         transport->old_write_space = sk->sk_write_space;
 779         transport->old_error_report = sk->sk_error_report;
 780 }
 781
 782 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 783 {
 784         sk->sk_data_ready = transport->old_data_ready;
 785         sk->sk_state_change = transport->old_state_change;
 786         sk->sk_write_space = transport->old_write_space;
 787         sk->sk_error_report = transport->old_error_report;
 788 }
 789
 790 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
 791 {
 792         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 793
 794         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
 795 }
 796
 797 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
 798 {
 799         smp_mb__before_atomic();
 800         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 801         clear_bit(XPRT_CLOSING, &xprt->state);
 802         xs_sock_reset_state_flags(xprt);
 803         smp_mb__after_atomic();
 804 }
 805
 806 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
 807 {
 808         xs_sock_reset_connection_flags(xprt);
 809         /* Mark transport as closed and wake up all pending tasks */
 810         xprt_disconnect_done(xprt);
 811 }
 812
 813 /**
 814  * xs_error_report - callback to handle TCP socket state errors
 815  * @sk: socket
 816  *
 817  * Note: we don't call sock_error() since there may be a rpc_task
 818  * using the socket, and so we don't want to clear sk->sk_err.
 819  */
 820 static void xs_error_report(struct sock *sk)
 821 {
 822         struct rpc_xprt *xprt;
 823         int err;
 824
 825         read_lock_bh(&sk->sk_callback_lock);
 826         if (!(xprt = xprt_from_sock(sk)))
 827                 goto out;
 828
 829         err = -sk->sk_err;
 830         if (err == 0)
 831                 goto out;
 832         /* Is this a reset event? */
 833         if (sk->sk_state == TCP_CLOSE)
 834                 xs_sock_mark_closed(xprt);
 835         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 836                         xprt, -err);
 837         trace_rpc_socket_error(xprt, sk->sk_socket, err);
 838         xprt_wake_pending_tasks(xprt, err);
 839  out:
 840         read_unlock_bh(&sk->sk_callback_lock);
 841 }
 842
 843 static void xs_reset_transport(struct sock_xprt *transport)
 844 {
 845         struct socket *sock = transport->sock;
 846         struct sock *sk = transport->inet;
 847         struct rpc_xprt *xprt = &transport->xprt;
 848
 849         if (sk == NULL)
 850                 return;
 851
 852         if (atomic_read(&transport->xprt.swapper))
 853                 sk_clear_memalloc(sk);
 854
 855         kernel_sock_shutdown(sock, SHUT_RDWR);
 856
 857         mutex_lock(&transport->recv_mutex);
 858         write_lock_bh(&sk->sk_callback_lock);
 859         transport->inet = NULL;
 860         transport->sock = NULL;
 861
 862         sk->sk_user_data = NULL;
 863
 864         xs_restore_old_callbacks(transport, sk);
 865         xprt_clear_connected(xprt);
 866         write_unlock_bh(&sk->sk_callback_lock);
 867         xs_sock_reset_connection_flags(xprt);
 868         mutex_unlock(&transport->recv_mutex);
 869
 870         trace_rpc_socket_close(xprt, sock);
 871         sock_release(sock);
 872 }
 873
 874 /**
 875  * xs_close - close a socket
 876  * @xprt: transport
 877  *
 878  * This is used when all requests are complete; ie, no DRC state remains
 879  * on the server we want to save.
 880  *
 881  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 882  * xs_reset_transport() zeroing the socket from underneath a writer.
 883  */
 884 static void xs_close(struct rpc_xprt *xprt)
 885 {
 886         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 887
 888         dprintk("RPC:       xs_close xprt %p\n", xprt);
 889
 890         xs_reset_transport(transport);
 891         xprt->reestablish_timeout = 0;
 892
 893         xprt_disconnect_done(xprt);
 894 }
 895
 896 static void xs_inject_disconnect(struct rpc_xprt *xprt)
 897 {
 898         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
 899                 xprt);
 900         xprt_disconnect_done(xprt);
 901 }
 902
 903 static void xs_xprt_free(struct rpc_xprt *xprt)
 904 {
 905         xs_free_peer_addresses(xprt);
 906         xprt_free(xprt);
 907 }
 908
 909 /**
 910  * xs_destroy - prepare to shutdown a transport
 911  * @xprt: doomed transport
 912  *
 913  */
 914 static void xs_destroy(struct rpc_xprt *xprt)
 915 {
 916         struct sock_xprt *transport = container_of(xprt,
 917                         struct sock_xprt, xprt);
 918         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 919
 920         cancel_delayed_work_sync(&transport->connect_worker);
 921         xs_close(xprt);
 922         cancel_work_sync(&transport->recv_worker);
 923         xs_xprt_free(xprt);
 924         module_put(THIS_MODULE);
 925 }
 926
 927 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 928 {
 929         struct xdr_skb_reader desc = {
 930                 .skb            = skb,
 931                 .offset         = sizeof(rpc_fraghdr),
 932                 .count          = skb->len - sizeof(rpc_fraghdr),
 933         };
 934
 935         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
 936                 return -1;
 937         if (desc.count)
 938                 return -1;
 939         return 0;
 940 }
 941
 942 /**
 943  * xs_local_data_read_skb
 944  * @xprt: transport
 945  * @sk: socket
 946  * @skb: skbuff
 947  *
 948  * Currently this assumes we can read the whole reply in a single gulp.
 949  */
 950 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
 951                 struct sock *sk,
 952                 struct sk_buff *skb)
 953 {
 954         struct rpc_task *task;
 955         struct rpc_rqst *rovr;
 956         int repsize, copied;
 957         u32 _xid;
 958         __be32 *xp;
 959
 960         repsize = skb->len - sizeof(rpc_fraghdr);
 961         if (repsize < 4) {
 962                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
 963                 return;
 964         }
 965
 966         /* Copy the XID from the skb... */
 967         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 968         if (xp == NULL)
 969                 return;
 970
 971         /* Look up and lock the request corresponding to the given XID */
 972         spin_lock(&xprt->recv_lock);
 973         rovr = xprt_lookup_rqst(xprt, *xp);
 974         if (!rovr)
 975                 goto out_unlock;
 976         xprt_pin_rqst(rovr);
 977         spin_unlock(&xprt->recv_lock);
 978         task = rovr->rq_task;
 979
 980         copied = rovr->rq_private_buf.buflen;
 981         if (copied > repsize)
 982                 copied = repsize;
 983
 984         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 985                 dprintk("RPC:       sk_buff copy failed\n");
 986                 spin_lock(&xprt->recv_lock);
 987                 goto out_unpin;
 988         }
 989
 990         spin_lock(&xprt->recv_lock);
 991         xprt_complete_rqst(task, copied);
 992 out_unpin:
 993         xprt_unpin_rqst(rovr);
 994  out_unlock:
 995         spin_unlock(&xprt->recv_lock);
 996 }
 997
 998 static void xs_local_data_receive(struct sock_xprt *transport)
 999 {
1000         struct sk_buff *skb;
1001         struct sock *sk;
1002         int err;
1003
1004         mutex_lock(&transport->recv_mutex);
1005         sk = transport->inet;
1006         if (sk == NULL)
1007                 goto out;
1008         for (;;) {
1009                 skb = skb_recv_datagram(sk, 0, 1, &err);
1010                 if (skb != NULL) {
1011                         xs_local_data_read_skb(&transport->xprt, sk, skb);
1012                         skb_free_datagram(sk, skb);
1013                         continue;
1014                 }
1015                 if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1016                         break;
1017         }
1018 out:
1019         mutex_unlock(&transport->recv_mutex);
1020 }
1021
1022 static void xs_local_data_receive_workfn(struct work_struct *work)
1023 {
1024         struct sock_xprt *transport =
1025                 container_of(work, struct sock_xprt, recv_worker);
1026         xs_local_data_receive(transport);
1027 }
1028
1029 /**
1030  * xs_udp_data_read_skb - receive callback for UDP sockets
1031  * @xprt: transport
1032  * @sk: socket
1033  * @skb: skbuff
1034  *
1035  */
1036 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1037                 struct sock *sk,
1038                 struct sk_buff *skb)
1039 {
1040         struct rpc_task *task;
1041         struct rpc_rqst *rovr;
1042         int repsize, copied;
1043         u32 _xid;
1044         __be32 *xp;
1045
1046         repsize = skb->len;
1047         if (repsize < 4) {
1048                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1049                 return;
1050         }
1051
1052         /* Copy the XID from the skb... */
1053         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1054         if (xp == NULL)
1055                 return;
1056
1057         /* Look up and lock the request corresponding to the given XID */
1058         spin_lock(&xprt->recv_lock);
1059         rovr = xprt_lookup_rqst(xprt, *xp);
1060         if (!rovr)
1061                 goto out_unlock;
1062         xprt_pin_rqst(rovr);
1063         spin_unlock(&xprt->recv_lock);
1064         task = rovr->rq_task;
1065
1066         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1067                 copied = repsize;
1068
1069         /* Suck it into the iovec, verify checksum if not done by hw. */
1070         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1071                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1072                 spin_lock(&xprt->recv_lock);
1073                 goto out_unpin;
1074         }
1075
1076         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1077
1078         spin_lock_bh(&xprt->transport_lock);
1079         xprt_adjust_cwnd(xprt, task, copied);
1080         spin_unlock_bh(&xprt->transport_lock);
1081         spin_lock(&xprt->recv_lock);
1082         xprt_complete_rqst(task, copied);
1083 out_unpin:
1084         xprt_unpin_rqst(rovr);
1085  out_unlock:
1086         spin_unlock(&xprt->recv_lock);
1087 }
1088
1089 static void xs_udp_data_receive(struct sock_xprt *transport)
1090 {
1091         struct sk_buff *skb;
1092         struct sock *sk;
1093         int err;
1094
1095         mutex_lock(&transport->recv_mutex);
1096         sk = transport->inet;
1097         if (sk == NULL)
1098                 goto out;
1099         for (;;) {
1100                 skb = skb_recv_udp(sk, 0, 1, &err);
1101                 if (skb != NULL) {
1102                         xs_udp_data_read_skb(&transport->xprt, sk, skb);
1103                         consume_skb(skb);
1104                         continue;
1105                 }
1106                 if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1107                         break;
1108         }
1109 out:
1110         mutex_unlock(&transport->recv_mutex);
1111 }
1112
1113 static void xs_udp_data_receive_workfn(struct work_struct *work)
1114 {
1115         struct sock_xprt *transport =
1116                 container_of(work, struct sock_xprt, recv_worker);
1117         xs_udp_data_receive(transport);
1118 }
1119
1120 /**
1121  * xs_data_ready - "data ready" callback for UDP sockets
1122  * @sk: socket with data to read
1123  *
1124  */
1125 static void xs_data_ready(struct sock *sk)
1126 {
1127         struct rpc_xprt *xprt;
1128
1129         read_lock_bh(&sk->sk_callback_lock);
1130         dprintk("RPC:       xs_data_ready...\n");
1131         xprt = xprt_from_sock(sk);
1132         if (xprt != NULL) {
1133                 struct sock_xprt *transport = container_of(xprt,
1134                                 struct sock_xprt, xprt);
1135                 transport->old_data_ready(sk);
1136                 /* Any data means we had a useful conversation, so
1137                  * then we don't need to delay the next reconnect
1138                  */
1139                 if (xprt->reestablish_timeout)
1140                         xprt->reestablish_timeout = 0;
1141                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1142                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1143         }
1144         read_unlock_bh(&sk->sk_callback_lock);
1145 }
1146
1147 /*
1148  * Helper function to force a TCP close if the server is sending
1149  * junk and/or it has put us in CLOSE_WAIT
1150  */
1151 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1152 {
1153         xprt_force_disconnect(xprt);
1154 }
1155
1156 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1157 {
1158         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1159         size_t len, used;
1160         char *p;
1161
1162         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1163         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1164         used = xdr_skb_read_bits(desc, p, len);
1165         transport->tcp_offset += used;
1166         if (used != len)
1167                 return;
1168
1169         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1170         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1171                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1172         else
1173                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1174         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1175
1176         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1177         transport->tcp_offset = 0;
1178
1179         /* Sanity check of the record length */
1180         if (unlikely(transport->tcp_reclen < 8)) {
1181                 dprintk("RPC:       invalid TCP record fragment length\n");
1182                 xs_tcp_force_close(xprt);
1183                 return;
1184         }
1185         dprintk("RPC:       reading TCP record fragment of length %d\n",
1186                         transport->tcp_reclen);
1187 }
1188
1189 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1190 {
1191         if (transport->tcp_offset == transport->tcp_reclen) {
1192                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1193                 transport->tcp_offset = 0;
1194                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1195                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1196                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1197                         transport->tcp_copied = 0;
1198                 }
1199         }
1200 }
1201
1202 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1203 {
1204         size_t len, used;
1205         char *p;
1206
1207         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1208         dprintk("RPC:       reading XID (%zu bytes)\n", len);
1209         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1210         used = xdr_skb_read_bits(desc, p, len);
1211         transport->tcp_offset += used;
1212         if (used != len)
1213                 return;
1214         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1215         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1216         transport->tcp_copied = 4;
1217         dprintk("RPC:       reading %s XID %08x\n",
1218                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1219                                                               : "request with",
1220                         ntohl(transport->tcp_xid));
1221         xs_tcp_check_fraghdr(transport);
1222 }
1223
1224 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1225                                        struct xdr_skb_reader *desc)
1226 {
1227         size_t len, used;
1228         u32 offset;
1229         char *p;
1230
1231         /*
1232          * We want transport->tcp_offset to be 8 at the end of this routine
1233          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1234          * When this function is called for the first time,
1235          * transport->tcp_offset is 4 (after having already read the xid).
1236          */
1237         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1238         len = sizeof(transport->tcp_calldir) - offset;
1239         dprintk("RPC:       reading CALL/REPLY flag (%zu bytes)\n", len);
1240         p = ((char *) &transport->tcp_calldir) + offset;
1241         used = xdr_skb_read_bits(desc, p, len);
1242         transport->tcp_offset += used;
1243         if (used != len)
1244                 return;
1245         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1246         /*
1247          * We don't yet have the XDR buffer, so we will write the calldir
1248          * out after we get the buffer from the 'struct rpc_rqst'
1249          */
1250         switch (ntohl(transport->tcp_calldir)) {
1251         case RPC_REPLY:
1252                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1253                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1254                 transport->tcp_flags |= TCP_RPC_REPLY;
1255                 break;
1256         case RPC_CALL:
1257                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1258                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1259                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1260                 break;
1261         default:
1262                 dprintk("RPC:       invalid request message type\n");
1263                 xs_tcp_force_close(&transport->xprt);
1264         }
1265         xs_tcp_check_fraghdr(transport);
1266 }
1267
1268 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1269                                      struct xdr_skb_reader *desc,
1270                                      struct rpc_rqst *req)
1271 {
1272         struct sock_xprt *transport =
1273                                 container_of(xprt, struct sock_xprt, xprt);
1274         struct xdr_buf *rcvbuf;
1275         size_t len;
1276         ssize_t r;
1277
1278         rcvbuf = &req->rq_private_buf;
1279
1280         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1281                 /*
1282                  * Save the RPC direction in the XDR buffer
1283                  */
1284                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1285                         &transport->tcp_calldir,
1286                         sizeof(transport->tcp_calldir));
1287                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1288                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1289         }
1290
1291         len = desc->count;
1292         if (len > transport->tcp_reclen - transport->tcp_offset)
1293                 desc->count = transport->tcp_reclen - transport->tcp_offset;
1294         r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1295                                           desc, xdr_skb_read_bits);
1296
1297         if (desc->count) {
1298                 /* Error when copying to the receive buffer,
1299                  * usually because we weren't able to allocate
1300                  * additional buffer pages. All we can do now
1301                  * is turn off TCP_RCV_COPY_DATA, so the request
1302                  * will not receive any additional updates,
1303                  * and time out.
1304                  * Any remaining data from this record will
1305                  * be discarded.
1306                  */
1307                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1308                 dprintk("RPC:       XID %08x truncated request\n",
1309                                 ntohl(transport->tcp_xid));
1310                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1311                                 "tcp_offset = %u, tcp_reclen = %u\n",
1312                                 xprt, transport->tcp_copied,
1313                                 transport->tcp_offset, transport->tcp_reclen);
1314                 return;
1315         }
1316
1317         transport->tcp_copied += r;
1318         transport->tcp_offset += r;
1319         desc->count = len - r;
1320
1321         dprintk("RPC:       XID %08x read %zd bytes\n",
1322                         ntohl(transport->tcp_xid), r);
1323         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1324                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1325                         transport->tcp_offset, transport->tcp_reclen);
1326
1327         if (transport->tcp_copied == req->rq_private_buf.buflen)
1328                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1329         else if (transport->tcp_offset == transport->tcp_reclen) {
1330                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1331                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1332         }
1333 }
1334
1335 /*
1336  * Finds the request corresponding to the RPC xid and invokes the common
1337  * tcp read code to read the data.
1338  */
1339 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1340                                     struct xdr_skb_reader *desc)
1341 {
1342         struct sock_xprt *transport =
1343                                 container_of(xprt, struct sock_xprt, xprt);
1344         struct rpc_rqst *req;
1345
1346         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1347
1348         /* Find and lock the request corresponding to this xid */
1349         spin_lock(&xprt->recv_lock);
1350         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1351         if (!req) {
1352                 dprintk("RPC:       XID %08x request not found!\n",
1353                                 ntohl(transport->tcp_xid));
1354                 spin_unlock(&xprt->recv_lock);
1355                 return -1;
1356         }
1357         xprt_pin_rqst(req);
1358         spin_unlock(&xprt->recv_lock);
1359
1360         xs_tcp_read_common(xprt, desc, req);
1361
1362         spin_lock(&xprt->recv_lock);
1363         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1364                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1365         xprt_unpin_rqst(req);
1366         spin_unlock(&xprt->recv_lock);
1367         return 0;
1368 }
1369
1370 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1371 /*
1372  * Obtains an rpc_rqst previously allocated and invokes the common
1373  * tcp read code to read the data.  The result is placed in the callback
1374  * queue.
1375  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1376  * connection and return -1.
1377  */
1378 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1379                                        struct xdr_skb_reader *desc)
1380 {
1381         struct sock_xprt *transport =
1382                                 container_of(xprt, struct sock_xprt, xprt);
1383         struct rpc_rqst *req;
1384
1385         /* Look up the request corresponding to the given XID */
1386         req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1387         if (req == NULL) {
1388                 printk(KERN_WARNING "Callback slot table overflowed\n");
1389                 xprt_force_disconnect(xprt);
1390                 return -1;
1391         }
1392
1393         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1394         xs_tcp_read_common(xprt, desc, req);
1395
1396         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1397                 xprt_complete_bc_request(req, transport->tcp_copied);
1398
1399         return 0;
1400 }
1401
1402 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1403                                         struct xdr_skb_reader *desc)
1404 {
1405         struct sock_xprt *transport =
1406                                 container_of(xprt, struct sock_xprt, xprt);
1407
1408         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1409                 xs_tcp_read_reply(xprt, desc) :
1410                 xs_tcp_read_callback(xprt, desc);
1411 }
1412
1413 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1414 {
1415         int ret;
1416
1417         ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1418                               SVC_SOCK_ANONYMOUS);
1419         if (ret < 0)
1420                 return ret;
1421         return 0;
1422 }
1423
1424 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1425 {
1426         return PAGE_SIZE;
1427 }
1428 #else
1429 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1430                                         struct xdr_skb_reader *desc)
1431 {
1432         return xs_tcp_read_reply(xprt, desc);
1433 }
1434 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1435
1436 /*
1437  * Read data off the transport.  This can be either an RPC_CALL or an
1438  * RPC_REPLY.  Relay the processing to helper functions.
1439  */
1440 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1441                                     struct xdr_skb_reader *desc)
1442 {
1443         struct sock_xprt *transport =
1444                                 container_of(xprt, struct sock_xprt, xprt);
1445
1446         if (_xs_tcp_read_data(xprt, desc) == 0)
1447                 xs_tcp_check_fraghdr(transport);
1448         else {
1449                 /*
1450                  * The transport_lock protects the request handling.
1451                  * There's no need to hold it to update the tcp_flags.
1452                  */
1453                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1454         }
1455 }
1456
1457 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1458 {
1459         size_t len;
1460
1461         len = transport->tcp_reclen - transport->tcp_offset;
1462         if (len > desc->count)
1463                 len = desc->count;
1464         desc->count -= len;
1465         desc->offset += len;
1466         transport->tcp_offset += len;
1467         dprintk("RPC:       discarded %zu bytes\n", len);
1468         xs_tcp_check_fraghdr(transport);
1469 }
1470
1471 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1472 {
1473         struct rpc_xprt *xprt = rd_desc->arg.data;
1474         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1475         struct xdr_skb_reader desc = {
1476                 .skb    = skb,
1477                 .offset = offset,
1478                 .count  = len,
1479         };
1480
1481         dprintk("RPC:       xs_tcp_data_recv started\n");
1482         do {
1483                 trace_xs_tcp_data_recv(transport);
1484                 /* Read in a new fragment marker if necessary */
1485                 /* Can we ever really expect to get completely empty fragments? */
1486                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1487                         xs_tcp_read_fraghdr(xprt, &desc);
1488                         continue;
1489                 }
1490                 /* Read in the xid if necessary */
1491                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1492                         xs_tcp_read_xid(transport, &desc);
1493                         continue;
1494                 }
1495                 /* Read in the call/reply flag */
1496                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1497                         xs_tcp_read_calldir(transport, &desc);
1498                         continue;
1499                 }
1500                 /* Read in the request data */
1501                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1502                         xs_tcp_read_data(xprt, &desc);
1503                         continue;
1504                 }
1505                 /* Skip over any trailing bytes on short reads */
1506                 xs_tcp_read_discard(transport, &desc);
1507         } while (desc.count);
1508         trace_xs_tcp_data_recv(transport);
1509         dprintk("RPC:       xs_tcp_data_recv done\n");
1510         return len - desc.count;
1511 }
1512
1513 static void xs_tcp_data_receive(struct sock_xprt *transport)
1514 {
1515         struct rpc_xprt *xprt = &transport->xprt;
1516         struct sock *sk;
1517         read_descriptor_t rd_desc = {
1518                 .count = 2*1024*1024,
1519                 .arg.data = xprt,
1520         };
1521         unsigned long total = 0;
1522         int loop;
1523         int read = 0;
1524
1525         mutex_lock(&transport->recv_mutex);
1526         sk = transport->inet;
1527         if (sk == NULL)
1528                 goto out;
1529
1530         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1531         for (loop = 0; loop < 64; loop++) {
1532                 lock_sock(sk);
1533                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1534                 if (read <= 0) {
1535                         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1536                         release_sock(sk);
1537                         break;
1538                 }
1539                 release_sock(sk);
1540                 total += read;
1541                 rd_desc.count = 65536;
1542         }
1543         if (test_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1544                 queue_work(xprtiod_workqueue, &transport->recv_worker);
1545 out:
1546         mutex_unlock(&transport->recv_mutex);
1547         trace_xs_tcp_data_ready(xprt, read, total);
1548 }
1549
1550 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1551 {
1552         struct sock_xprt *transport =
1553                 container_of(work, struct sock_xprt, recv_worker);
1554         xs_tcp_data_receive(transport);
1555 }
1556
1557 /**
1558  * xs_tcp_state_change - callback to handle TCP socket state changes
1559  * @sk: socket whose state has changed
1560  *
1561  */
1562 static void xs_tcp_state_change(struct sock *sk)
1563 {
1564         struct rpc_xprt *xprt;
1565         struct sock_xprt *transport;
1566
1567         read_lock_bh(&sk->sk_callback_lock);
1568         if (!(xprt = xprt_from_sock(sk)))
1569                 goto out;
1570         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1571         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1572                         sk->sk_state, xprt_connected(xprt),
1573                         sock_flag(sk, SOCK_DEAD),
1574                         sock_flag(sk, SOCK_ZAPPED),
1575                         sk->sk_shutdown);
1576
1577         transport = container_of(xprt, struct sock_xprt, xprt);
1578         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1579         switch (sk->sk_state) {
1580         case TCP_ESTABLISHED:
1581                 spin_lock(&xprt->transport_lock);
1582                 if (!xprt_test_and_set_connected(xprt)) {
1583
1584                         /* Reset TCP record info */
1585                         transport->tcp_offset = 0;
1586                         transport->tcp_reclen = 0;
1587                         transport->tcp_copied = 0;
1588                         transport->tcp_flags =
1589                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1590                         xprt->connect_cookie++;
1591                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1592                         xprt_clear_connecting(xprt);
1593
1594                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1595                 }
1596                 spin_unlock(&xprt->transport_lock);
1597                 break;
1598         case TCP_FIN_WAIT1:
1599                 /* The client initiated a shutdown of the socket */
1600                 xprt->connect_cookie++;
1601                 xprt->reestablish_timeout = 0;
1602                 set_bit(XPRT_CLOSING, &xprt->state);
1603                 smp_mb__before_atomic();
1604                 clear_bit(XPRT_CONNECTED, &xprt->state);
1605                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1606                 smp_mb__after_atomic();
1607                 break;
1608         case TCP_CLOSE_WAIT:
1609                 /* The server initiated a shutdown of the socket */
1610                 xprt->connect_cookie++;
1611                 clear_bit(XPRT_CONNECTED, &xprt->state);
1612                 xs_tcp_force_close(xprt);
1613         case TCP_CLOSING:
1614                 /*
1615                  * If the server closed down the connection, make sure that
1616                  * we back off before reconnecting
1617                  */
1618                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1619                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1620                 break;
1621         case TCP_LAST_ACK:
1622                 set_bit(XPRT_CLOSING, &xprt->state);
1623                 smp_mb__before_atomic();
1624                 clear_bit(XPRT_CONNECTED, &xprt->state);
1625                 smp_mb__after_atomic();
1626                 break;
1627         case TCP_CLOSE:
1628                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1629                                         &transport->sock_state))
1630                         xprt_clear_connecting(xprt);
1631                 if (sk->sk_err)
1632                         xprt_wake_pending_tasks(xprt, -sk->sk_err);
1633                 xs_sock_mark_closed(xprt);
1634         }
1635  out:
1636         read_unlock_bh(&sk->sk_callback_lock);
1637 }
1638
1639 static void xs_write_space(struct sock *sk)
1640 {
1641         struct socket_wq *wq;
1642         struct rpc_xprt *xprt;
1643
1644         if (!sk->sk_socket)
1645                 return;
1646         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1647
1648         if (unlikely(!(xprt = xprt_from_sock(sk))))
1649                 return;
1650         rcu_read_lock();
1651         wq = rcu_dereference(sk->sk_wq);
1652         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1653                 goto out;
1654
1655         xprt_write_space(xprt);
1656 out:
1657         rcu_read_unlock();
1658 }
1659
1660 /**
1661  * xs_udp_write_space - callback invoked when socket buffer space
1662  *                             becomes available
1663  * @sk: socket whose state has changed
1664  *
1665  * Called when more output buffer space is available for this socket.
1666  * We try not to wake our writers until they can make "significant"
1667  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1668  * with a bunch of small requests.
1669  */
1670 static void xs_udp_write_space(struct sock *sk)
1671 {
1672         read_lock_bh(&sk->sk_callback_lock);
1673
1674         /* from net/core/sock.c:sock_def_write_space */
1675         if (sock_writeable(sk))
1676                 xs_write_space(sk);
1677
1678         read_unlock_bh(&sk->sk_callback_lock);
1679 }
1680
1681 /**
1682  * xs_tcp_write_space - callback invoked when socket buffer space
1683  *                             becomes available
1684  * @sk: socket whose state has changed
1685  *
1686  * Called when more output buffer space is available for this socket.
1687  * We try not to wake our writers until they can make "significant"
1688  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1689  * with a bunch of small requests.
1690  */
1691 static void xs_tcp_write_space(struct sock *sk)
1692 {
1693         read_lock_bh(&sk->sk_callback_lock);
1694
1695         /* from net/core/stream.c:sk_stream_write_space */
1696         if (sk_stream_is_writeable(sk))
1697                 xs_write_space(sk);
1698
1699         read_unlock_bh(&sk->sk_callback_lock);
1700 }
1701
1702 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1703 {
1704         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1705         struct sock *sk = transport->inet;
1706
1707         if (transport->rcvsize) {
1708                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1709                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1710         }
1711         if (transport->sndsize) {
1712                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1713                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1714                 sk->sk_write_space(sk);
1715         }
1716 }
1717
1718 /**
1719  * xs_udp_set_buffer_size - set send and receive limits
1720  * @xprt: generic transport
1721  * @sndsize: requested size of send buffer, in bytes
1722  * @rcvsize: requested size of receive buffer, in bytes
1723  *
1724  * Set socket send and receive buffer size limits.
1725  */
1726 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1727 {
1728         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1729
1730         transport->sndsize = 0;
1731         if (sndsize)
1732                 transport->sndsize = sndsize + 1024;
1733         transport->rcvsize = 0;
1734         if (rcvsize)
1735                 transport->rcvsize = rcvsize + 1024;
1736
1737         xs_udp_do_set_buffer_size(xprt);
1738 }
1739
1740 /**
1741  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1742  * @task: task that timed out
1743  *
1744  * Adjust the congestion window after a retransmit timeout has occurred.
1745  */
1746 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1747 {
1748         spin_lock_bh(&xprt->transport_lock);
1749         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1750         spin_unlock_bh(&xprt->transport_lock);
1751 }
1752
1753 static unsigned short xs_get_random_port(void)
1754 {
1755         unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
1756         unsigned short rand = (unsigned short) prandom_u32() % range;
1757         return rand + xprt_min_resvport;
1758 }
1759
1760 /**
1761  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1762  * @sock: socket
1763  *
1764  * Note that this function has to be called on all sockets that share the
1765  * same port, and it must be called before binding.
1766  */
1767 static void xs_sock_set_reuseport(struct socket *sock)
1768 {
1769         int opt = 1;
1770
1771         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1772                         (char *)&opt, sizeof(opt));
1773 }
1774
1775 static unsigned short xs_sock_getport(struct socket *sock)
1776 {
1777         struct sockaddr_storage buf;
1778         int buflen;
1779         unsigned short port = 0;
1780
1781         if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1782                 goto out;
1783         switch (buf.ss_family) {
1784         case AF_INET6:
1785                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1786                 break;
1787         case AF_INET:
1788                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1789         }
1790 out:
1791         return port;
1792 }
1793
1794 /**
1795  * xs_set_port - reset the port number in the remote endpoint address
1796  * @xprt: generic transport
1797  * @port: new port number
1798  *
1799  */
1800 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1801 {
1802         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1803
1804         rpc_set_port(xs_addr(xprt), port);
1805         xs_update_peer_port(xprt);
1806 }
1807
1808 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1809 {
1810         if (transport->srcport == 0)
1811                 transport->srcport = xs_sock_getport(sock);
1812 }
1813
1814 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1815 {
1816         unsigned short port = transport->srcport;
1817
1818         if (port == 0 && transport->xprt.resvport)
1819                 port = xs_get_random_port();
1820         return port;
1821 }
1822
1823 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1824 {
1825         if (transport->srcport != 0)
1826                 transport->srcport = 0;
1827         if (!transport->xprt.resvport)
1828                 return 0;
1829         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1830                 return xprt_max_resvport;
1831         return --port;
1832 }
1833 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1834 {
1835         struct sockaddr_storage myaddr;
1836         int err, nloop = 0;
1837         unsigned short port = xs_get_srcport(transport);
1838         unsigned short last;
1839
1840         /*
1841          * If we are asking for any ephemeral port (i.e. port == 0 &&
1842          * transport->xprt.resvport == 0), don't bind.  Let the local
1843          * port selection happen implicitly when the socket is used
1844          * (for example at connect time).
1845          *
1846          * This ensures that we can continue to establish TCP
1847          * connections even when all local ephemeral ports are already
1848          * a part of some TCP connection.  This makes no difference
1849          * for UDP sockets, but also doens't harm them.
1850          *
1851          * If we're asking for any reserved port (i.e. port == 0 &&
1852          * transport->xprt.resvport == 1) xs_get_srcport above will
1853          * ensure that port is non-zero and we will bind as needed.
1854          */
1855         if (port == 0)
1856                 return 0;
1857
1858         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1859         do {
1860                 rpc_set_port((struct sockaddr *)&myaddr, port);
1861                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1862                                 transport->xprt.addrlen);
1863                 if (err == 0) {
1864                         transport->srcport = port;
1865                         break;
1866                 }
1867                 last = port;
1868                 port = xs_next_srcport(transport, port);
1869                 if (port > last)
1870                         nloop++;
1871         } while (err == -EADDRINUSE && nloop != 2);
1872
1873         if (myaddr.ss_family == AF_INET)
1874                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1875                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1876                                 port, err ? "failed" : "ok", err);
1877         else
1878                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1879                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1880                                 port, err ? "failed" : "ok", err);
1881         return err;
1882 }
1883
1884 /*
1885  * We don't support autobind on AF_LOCAL sockets
1886  */
1887 static void xs_local_rpcbind(struct rpc_task *task)
1888 {
1889         xprt_set_bound(task->tk_xprt);
1890 }
1891
1892 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1893 {
1894 }
1895
1896 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1897 static struct lock_class_key xs_key[2];
1898 static struct lock_class_key xs_slock_key[2];
1899
1900 static inline void xs_reclassify_socketu(struct socket *sock)
1901 {
1902         struct sock *sk = sock->sk;
1903
1904         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1905                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1906 }
1907
1908 static inline void xs_reclassify_socket4(struct socket *sock)
1909 {
1910         struct sock *sk = sock->sk;
1911
1912         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1913                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1914 }
1915
1916 static inline void xs_reclassify_socket6(struct socket *sock)
1917 {
1918         struct sock *sk = sock->sk;
1919
1920         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1921                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1922 }
1923
1924 static inline void xs_reclassify_socket(int family, struct socket *sock)
1925 {
1926         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1927                 return;
1928
1929         switch (family) {
1930         case AF_LOCAL:
1931                 xs_reclassify_socketu(sock);
1932                 break;
1933         case AF_INET:
1934                 xs_reclassify_socket4(sock);
1935                 break;
1936         case AF_INET6:
1937                 xs_reclassify_socket6(sock);
1938                 break;
1939         }
1940 }
1941 #else
1942 static inline void xs_reclassify_socket(int family, struct socket *sock)
1943 {
1944 }
1945 #endif
1946
1947 static void xs_dummy_setup_socket(struct work_struct *work)
1948 {
1949 }
1950
1951 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1952                 struct sock_xprt *transport, int family, int type,
1953                 int protocol, bool reuseport)
1954 {
1955         struct socket *sock;
1956         int err;
1957
1958         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1959         if (err < 0) {
1960                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1961                                 protocol, -err);
1962                 goto out;
1963         }
1964         xs_reclassify_socket(family, sock);
1965
1966         if (reuseport)
1967                 xs_sock_set_reuseport(sock);
1968
1969         err = xs_bind(transport, sock);
1970         if (err) {
1971                 sock_release(sock);
1972                 goto out;
1973         }
1974
1975         return sock;
1976 out:
1977         return ERR_PTR(err);
1978 }
1979
1980 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1981                                       struct socket *sock)
1982 {
1983         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1984                                                                         xprt);
1985
1986         if (!transport->inet) {
1987                 struct sock *sk = sock->sk;
1988
1989                 write_lock_bh(&sk->sk_callback_lock);
1990
1991                 xs_save_old_callbacks(transport, sk);
1992
1993                 sk->sk_user_data = xprt;
1994                 sk->sk_data_ready = xs_data_ready;
1995                 sk->sk_write_space = xs_udp_write_space;
1996                 sock_set_flag(sk, SOCK_FASYNC);
1997                 sk->sk_error_report = xs_error_report;
1998                 sk->sk_allocation = GFP_NOIO;
1999
2000                 xprt_clear_connected(xprt);
2001
2002                 /* Reset to new socket */
2003                 transport->sock = sock;
2004                 transport->inet = sk;
2005
2006                 write_unlock_bh(&sk->sk_callback_lock);
2007         }
2008
2009         /* Tell the socket layer to start connecting... */
2010         xprt->stat.connect_count++;
2011         xprt->stat.connect_start = jiffies;
2012         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
2013 }
2014
2015 /**
2016  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
2017  * @transport: socket transport to connect
2018  */
2019 static int xs_local_setup_socket(struct sock_xprt *transport)
2020 {
2021         struct rpc_xprt *xprt = &transport->xprt;
2022         struct socket *sock;
2023         int status = -EIO;
2024
2025         status = __sock_create(xprt->xprt_net, AF_LOCAL,
2026                                         SOCK_STREAM, 0, &sock, 1);
2027         if (status < 0) {
2028                 dprintk("RPC:       can't create AF_LOCAL "
2029                         "transport socket (%d).\n", -status);
2030                 goto out;
2031         }
2032         xs_reclassify_socket(AF_LOCAL, sock);
2033
2034         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
2035                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2036
2037         status = xs_local_finish_connecting(xprt, sock);
2038         trace_rpc_socket_connect(xprt, sock, status);
2039         switch (status) {
2040         case 0:
2041                 dprintk("RPC:       xprt %p connected to %s\n",
2042                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2043                 xprt_set_connected(xprt);
2044         case -ENOBUFS:
2045                 break;
2046         case -ENOENT:
2047                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
2048                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2049                 break;
2050         case -ECONNREFUSED:
2051                 dprintk("RPC:       xprt %p: connection refused for %s\n",
2052                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2053                 break;
2054         default:
2055                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2056                                 __func__, -status,
2057                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
2058         }
2059
2060 out:
2061         xprt_clear_connecting(xprt);
2062         xprt_wake_pending_tasks(xprt, status);
2063         return status;
2064 }
2065
2066 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2067 {
2068         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2069         int ret;
2070
2071          if (RPC_IS_ASYNC(task)) {
2072                 /*
2073                  * We want the AF_LOCAL connect to be resolved in the
2074                  * filesystem namespace of the process making the rpc
2075                  * call.  Thus we connect synchronously.
2076                  *
2077                  * If we want to support asynchronous AF_LOCAL calls,
2078                  * we'll need to figure out how to pass a namespace to
2079                  * connect.
2080                  */
2081                 rpc_exit(task, -ENOTCONN);
2082                 return;
2083         }
2084         ret = xs_local_setup_socket(transport);
2085         if (ret && !RPC_IS_SOFTCONN(task))
2086                 msleep_interruptible(15000);
2087 }
2088
2089 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2090 /*
2091  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2092  * know that we have exclusive access to the socket), to guard against
2093  * races with xs_reset_transport.
2094  */
2095 static void xs_set_memalloc(struct rpc_xprt *xprt)
2096 {
2097         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2098                         xprt);
2099
2100         /*
2101          * If there's no sock, then we have nothing to set. The
2102          * reconnecting process will get it for us.
2103          */
2104         if (!transport->inet)
2105                 return;
2106         if (atomic_read(&xprt->swapper))
2107                 sk_set_memalloc(transport->inet);
2108 }
2109
2110 /**
2111  * xs_enable_swap - Tag this transport as being used for swap.
2112  * @xprt: transport to tag
2113  *
2114  * Take a reference to this transport on behalf of the rpc_clnt, and
2115  * optionally mark it for swapping if it wasn't already.
2116  */
2117 static int
2118 xs_enable_swap(struct rpc_xprt *xprt)
2119 {
2120         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2121
2122         if (atomic_inc_return(&xprt->swapper) != 1)
2123                 return 0;
2124         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2125                 return -ERESTARTSYS;
2126         if (xs->inet)
2127                 sk_set_memalloc(xs->inet);
2128         xprt_release_xprt(xprt, NULL);
2129         return 0;
2130 }
2131
2132 /**
2133  * xs_disable_swap - Untag this transport as being used for swap.
2134  * @xprt: transport to tag
2135  *
2136  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2137  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2138  */
2139 static void
2140 xs_disable_swap(struct rpc_xprt *xprt)
2141 {
2142         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2143
2144         if (!atomic_dec_and_test(&xprt->swapper))
2145                 return;
2146         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2147                 return;
2148         if (xs->inet)
2149                 sk_clear_memalloc(xs->inet);
2150         xprt_release_xprt(xprt, NULL);
2151 }
2152 #else
2153 static void xs_set_memalloc(struct rpc_xprt *xprt)
2154 {
2155 }
2156
2157 static int
2158 xs_enable_swap(struct rpc_xprt *xprt)
2159 {
2160         return -EINVAL;
2161 }
2162
2163 static void
2164 xs_disable_swap(struct rpc_xprt *xprt)
2165 {
2166 }
2167 #endif
2168
2169 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2170 {
2171         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2172
2173         if (!transport->inet) {
2174                 struct sock *sk = sock->sk;
2175
2176                 write_lock_bh(&sk->sk_callback_lock);
2177
2178                 xs_save_old_callbacks(transport, sk);
2179
2180                 sk->sk_user_data = xprt;
2181                 sk->sk_data_ready = xs_data_ready;
2182                 sk->sk_write_space = xs_udp_write_space;
2183                 sock_set_flag(sk, SOCK_FASYNC);
2184                 sk->sk_allocation = GFP_NOIO;
2185
2186                 xprt_set_connected(xprt);
2187
2188                 /* Reset to new socket */
2189                 transport->sock = sock;
2190                 transport->inet = sk;
2191
2192                 xs_set_memalloc(xprt);
2193
2194                 write_unlock_bh(&sk->sk_callback_lock);
2195         }
2196         xs_udp_do_set_buffer_size(xprt);
2197
2198         xprt->stat.connect_start = jiffies;
2199 }
2200
2201 static void xs_udp_setup_socket(struct work_struct *work)
2202 {
2203         struct sock_xprt *transport =
2204                 container_of(work, struct sock_xprt, connect_worker.work);
2205         struct rpc_xprt *xprt = &transport->xprt;
2206         struct socket *sock;
2207         int status = -EIO;
2208
2209         sock = xs_create_sock(xprt, transport,
2210                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2211                         IPPROTO_UDP, false);
2212         if (IS_ERR(sock))
2213                 goto out;
2214
2215         dprintk("RPC:       worker connecting xprt %p via %s to "
2216                                 "%s (port %s)\n", xprt,
2217                         xprt->address_strings[RPC_DISPLAY_PROTO],
2218                         xprt->address_strings[RPC_DISPLAY_ADDR],
2219                         xprt->address_strings[RPC_DISPLAY_PORT]);
2220
2221         xs_udp_finish_connecting(xprt, sock);
2222         trace_rpc_socket_connect(xprt, sock, 0);
2223         status = 0;
2224 out:
2225         xprt_unlock_connect(xprt, transport);
2226         xprt_clear_connecting(xprt);
2227         xprt_wake_pending_tasks(xprt, status);
2228 }
2229
2230 /**
2231  * xs_tcp_shutdown - gracefully shut down a TCP socket
2232  * @xprt: transport
2233  *
2234  * Initiates a graceful shutdown of the TCP socket by calling the
2235  * equivalent of shutdown(SHUT_RDWR);
2236  */
2237 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2238 {
2239         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2240         struct socket *sock = transport->sock;
2241
2242         if (sock == NULL)
2243                 return;
2244         if (xprt_connected(xprt)) {
2245                 kernel_sock_shutdown(sock, SHUT_RDWR);
2246                 trace_rpc_socket_shutdown(xprt, sock);
2247         } else
2248                 xs_reset_transport(transport);
2249 }
2250
2251 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2252                 struct socket *sock)
2253 {
2254         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2255         unsigned int keepidle;
2256         unsigned int keepcnt;
2257         unsigned int opt_on = 1;
2258         unsigned int timeo;
2259
2260         spin_lock_bh(&xprt->transport_lock);
2261         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2262         keepcnt = xprt->timeout->to_retries + 1;
2263         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2264                 (xprt->timeout->to_retries + 1);
2265         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2266         spin_unlock_bh(&xprt->transport_lock);
2267
2268         /* TCP Keepalive options */
2269         kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2270                         (char *)&opt_on, sizeof(opt_on));
2271         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2272                         (char *)&keepidle, sizeof(keepidle));
2273         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2274                         (char *)&keepidle, sizeof(keepidle));
2275         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2276                         (char *)&keepcnt, sizeof(keepcnt));
2277
2278         /* TCP user timeout (see RFC5482) */
2279         kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2280                         (char *)&timeo, sizeof(timeo));
2281 }
2282
2283 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2284                 unsigned long connect_timeout,
2285                 unsigned long reconnect_timeout)
2286 {
2287         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2288         struct rpc_timeout to;
2289         unsigned long initval;
2290
2291         spin_lock_bh(&xprt->transport_lock);
2292         if (reconnect_timeout < xprt->max_reconnect_timeout)
2293                 xprt->max_reconnect_timeout = reconnect_timeout;
2294         if (connect_timeout < xprt->connect_timeout) {
2295                 memcpy(&to, xprt->timeout, sizeof(to));
2296                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2297                 /* Arbitrary lower limit */
2298                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2299                         initval = XS_TCP_INIT_REEST_TO << 1;
2300                 to.to_initval = initval;
2301                 to.to_maxval = initval;
2302                 memcpy(&transport->tcp_timeout, &to,
2303                                 sizeof(transport->tcp_timeout));
2304                 xprt->timeout = &transport->tcp_timeout;
2305                 xprt->connect_timeout = connect_timeout;
2306         }
2307         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2308         spin_unlock_bh(&xprt->transport_lock);
2309 }
2310
2311 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2312 {
2313         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2314         int ret = -ENOTCONN;
2315
2316         if (!transport->inet) {
2317                 struct sock *sk = sock->sk;
2318                 unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2319
2320                 /* Avoid temporary address, they are bad for long-lived
2321                  * connections such as NFS mounts.
2322                  * RFC4941, section 3.6 suggests that:
2323                  *    Individual applications, which have specific
2324                  *    knowledge about the normal duration of connections,
2325                  *    MAY override this as appropriate.
2326                  */
2327                 kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2328                                 (char *)&addr_pref, sizeof(addr_pref));
2329
2330                 xs_tcp_set_socket_timeouts(xprt, sock);
2331
2332                 write_lock_bh(&sk->sk_callback_lock);
2333
2334                 xs_save_old_callbacks(transport, sk);
2335
2336                 sk->sk_user_data = xprt;
2337                 sk->sk_data_ready = xs_data_ready;
2338                 sk->sk_state_change = xs_tcp_state_change;
2339                 sk->sk_write_space = xs_tcp_write_space;
2340                 sock_set_flag(sk, SOCK_FASYNC);
2341                 sk->sk_error_report = xs_error_report;
2342                 sk->sk_allocation = GFP_NOIO;
2343
2344                 /* socket options */
2345                 sock_reset_flag(sk, SOCK_LINGER);
2346                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2347
2348                 xprt_clear_connected(xprt);
2349
2350                 /* Reset to new socket */
2351                 transport->sock = sock;
2352                 transport->inet = sk;
2353
2354                 write_unlock_bh(&sk->sk_callback_lock);
2355         }
2356
2357         if (!xprt_bound(xprt))
2358                 goto out;
2359
2360         xs_set_memalloc(xprt);
2361
2362         /* Tell the socket layer to start connecting... */
2363         xprt->stat.connect_count++;
2364         xprt->stat.connect_start = jiffies;
2365         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2366         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2367         switch (ret) {
2368         case 0:
2369                 xs_set_srcport(transport, sock);
2370         case -EINPROGRESS:
2371                 /* SYN_SENT! */
2372                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2373                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2374                 break;
2375         case -EADDRNOTAVAIL:
2376                 /* Source port number is unavailable. Try a new one! */
2377                 transport->srcport = 0;
2378         }
2379 out:
2380         return ret;
2381 }
2382
2383 /**
2384  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2385  *
2386  * Invoked by a work queue tasklet.
2387  */
2388 static void xs_tcp_setup_socket(struct work_struct *work)
2389 {
2390         struct sock_xprt *transport =
2391                 container_of(work, struct sock_xprt, connect_worker.work);
2392         struct socket *sock = transport->sock;
2393         struct rpc_xprt *xprt = &transport->xprt;
2394         int status = -EIO;
2395
2396         if (!sock) {
2397                 sock = xs_create_sock(xprt, transport,
2398                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2399                                 IPPROTO_TCP, true);
2400                 if (IS_ERR(sock)) {
2401                         status = PTR_ERR(sock);
2402                         goto out;
2403                 }
2404         }
2405
2406         dprintk("RPC:       worker connecting xprt %p via %s to "
2407                                 "%s (port %s)\n", xprt,
2408                         xprt->address_strings[RPC_DISPLAY_PROTO],
2409                         xprt->address_strings[RPC_DISPLAY_ADDR],
2410                         xprt->address_strings[RPC_DISPLAY_PORT]);
2411
2412         status = xs_tcp_finish_connecting(xprt, sock);
2413         trace_rpc_socket_connect(xprt, sock, status);
2414         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2415                         xprt, -status, xprt_connected(xprt),
2416                         sock->sk->sk_state);
2417         switch (status) {
2418         default:
2419                 printk("%s: connect returned unhandled error %d\n",
2420                         __func__, status);
2421         case -EADDRNOTAVAIL:
2422                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2423                  * and retry
2424                  */
2425                 xs_tcp_force_close(xprt);
2426                 break;
2427         case 0:
2428         case -EINPROGRESS:
2429         case -EALREADY:
2430                 xprt_unlock_connect(xprt, transport);
2431                 return;
2432         case -EINVAL:
2433                 /* Happens, for instance, if the user specified a link
2434                  * local IPv6 address without a scope-id.
2435                  */
2436         case -ECONNREFUSED:
2437         case -ECONNRESET:
2438         case -ENETUNREACH:
2439         case -EADDRINUSE:
2440         case -ENOBUFS:
2441                 /*
2442                  * xs_tcp_force_close() wakes tasks with -EIO.
2443                  * We need to wake them first to ensure the
2444                  * correct error code.
2445                  */
2446                 xprt_wake_pending_tasks(xprt, status);
2447                 xs_tcp_force_close(xprt);
2448                 goto out;
2449         }
2450         status = -EAGAIN;
2451 out:
2452         xprt_unlock_connect(xprt, transport);
2453         xprt_clear_connecting(xprt);
2454         xprt_wake_pending_tasks(xprt, status);
2455 }
2456
2457 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2458 {
2459         unsigned long start, now = jiffies;
2460
2461         start = xprt->stat.connect_start + xprt->reestablish_timeout;
2462         if (time_after(start, now))
2463                 return start - now;
2464         return 0;
2465 }
2466
2467 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2468 {
2469         xprt->reestablish_timeout <<= 1;
2470         if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2471                 xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2472         if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2473                 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2474 }
2475
2476 /**
2477  * xs_connect - connect a socket to a remote endpoint
2478  * @xprt: pointer to transport structure
2479  * @task: address of RPC task that manages state of connect request
2480  *
2481  * TCP: If the remote end dropped the connection, delay reconnecting.
2482  *
2483  * UDP socket connects are synchronous, but we use a work queue anyway
2484  * to guarantee that even unprivileged user processes can set up a
2485  * socket on a privileged port.
2486  *
2487  * If a UDP socket connect fails, the delay behavior here prevents
2488  * retry floods (hard mounts).
2489  */
2490 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2491 {
2492         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2493         unsigned long delay = 0;
2494
2495         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2496
2497         if (transport->sock != NULL) {
2498                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2499                                 "seconds\n",
2500                                 xprt, xprt->reestablish_timeout / HZ);
2501
2502                 /* Start by resetting any existing state */
2503                 xs_reset_transport(transport);
2504
2505                 delay = xs_reconnect_delay(xprt);
2506                 xs_reconnect_backoff(xprt);
2507
2508         } else
2509                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2510
2511         queue_delayed_work(xprtiod_workqueue,
2512                         &transport->connect_worker,
2513                         delay);
2514 }
2515
2516 /**
2517  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2518  * @xprt: rpc_xprt struct containing statistics
2519  * @seq: output file
2520  *
2521  */
2522 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2523 {
2524         long idle_time = 0;
2525
2526         if (xprt_connected(xprt))
2527                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2528
2529         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2530                         "%llu %llu %lu %llu %llu\n",
2531                         xprt->stat.bind_count,
2532                         xprt->stat.connect_count,
2533                         xprt->stat.connect_time,
2534                         idle_time,
2535                         xprt->stat.sends,
2536                         xprt->stat.recvs,
2537                         xprt->stat.bad_xids,
2538                         xprt->stat.req_u,
2539                         xprt->stat.bklog_u,
2540                         xprt->stat.max_slots,
2541                         xprt->stat.sending_u,
2542                         xprt->stat.pending_u);
2543 }
2544
2545 /**
2546  * xs_udp_print_stats - display UDP socket-specifc stats
2547  * @xprt: rpc_xprt struct containing statistics
2548  * @seq: output file
2549  *
2550  */
2551 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2552 {
2553         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2554
2555         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2556                         "%lu %llu %llu\n",
2557                         transport->srcport,
2558                         xprt->stat.bind_count,
2559                         xprt->stat.sends,
2560                         xprt->stat.recvs,
2561                         xprt->stat.bad_xids,
2562                         xprt->stat.req_u,
2563                         xprt->stat.bklog_u,
2564                         xprt->stat.max_slots,
2565                         xprt->stat.sending_u,
2566                         xprt->stat.pending_u);
2567 }
2568
2569 /**
2570  * xs_tcp_print_stats - display TCP socket-specifc stats
2571  * @xprt: rpc_xprt struct containing statistics
2572  * @seq: output file
2573  *
2574  */
2575 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2576 {
2577         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2578         long idle_time = 0;
2579
2580         if (xprt_connected(xprt))
2581                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2582
2583         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2584                         "%llu %llu %lu %llu %llu\n",
2585                         transport->srcport,
2586                         xprt->stat.bind_count,
2587                         xprt->stat.connect_count,
2588                         xprt->stat.connect_time,
2589                         idle_time,
2590                         xprt->stat.sends,
2591                         xprt->stat.recvs,
2592                         xprt->stat.bad_xids,
2593                         xprt->stat.req_u,
2594                         xprt->stat.bklog_u,
2595                         xprt->stat.max_slots,
2596                         xprt->stat.sending_u,
2597                         xprt->stat.pending_u);
2598 }
2599
2600 /*
2601  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2602  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2603  * to use the server side send routines.
2604  */
2605 static int bc_malloc(struct rpc_task *task)
2606 {
2607         struct rpc_rqst *rqst = task->tk_rqstp;
2608         size_t size = rqst->rq_callsize;
2609         struct page *page;
2610         struct rpc_buffer *buf;
2611
2612         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2613                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2614                           size);
2615                 return -EINVAL;
2616         }
2617
2618         page = alloc_page(GFP_KERNEL);
2619         if (!page)
2620                 return -ENOMEM;
2621
2622         buf = page_address(page);
2623         buf->len = PAGE_SIZE;
2624
2625         rqst->rq_buffer = buf->data;
2626         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2627         return 0;
2628 }
2629
2630 /*
2631  * Free the space allocated in the bc_alloc routine
2632  */
2633 static void bc_free(struct rpc_task *task)
2634 {
2635         void *buffer = task->tk_rqstp->rq_buffer;
2636         struct rpc_buffer *buf;
2637
2638         buf = container_of(buffer, struct rpc_buffer, data);
2639         free_page((unsigned long)buf);
2640 }
2641
2642 /*
2643  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2644  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2645  */
2646 static int bc_sendto(struct rpc_rqst *req)
2647 {
2648         int len;
2649         struct xdr_buf *xbufp = &req->rq_snd_buf;
2650         struct rpc_xprt *xprt = req->rq_xprt;
2651         struct sock_xprt *transport =
2652                                 container_of(xprt, struct sock_xprt, xprt);
2653         struct socket *sock = transport->sock;
2654         unsigned long headoff;
2655         unsigned long tailoff;
2656
2657         xs_encode_stream_record_marker(xbufp);
2658
2659         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2660         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2661         len = svc_send_common(sock, xbufp,
2662                               virt_to_page(xbufp->head[0].iov_base), headoff,
2663                               xbufp->tail[0].iov_base, tailoff);
2664
2665         if (len != xbufp->len) {
2666                 printk(KERN_NOTICE "Error sending entire callback!\n");
2667                 len = -EAGAIN;
2668         }
2669
2670         return len;
2671 }
2672
2673 /*
2674  * The send routine. Borrows from svc_send
2675  */
2676 static int bc_send_request(struct rpc_task *task)
2677 {
2678         struct rpc_rqst *req = task->tk_rqstp;
2679         struct svc_xprt *xprt;
2680         int len;
2681
2682         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2683         /*
2684          * Get the server socket associated with this callback xprt
2685          */
2686         xprt = req->rq_xprt->bc_xprt;
2687
2688         /*
2689          * Grab the mutex to serialize data as the connection is shared
2690          * with the fore channel
2691          */
2692         if (!mutex_trylock(&xprt->xpt_mutex)) {
2693                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2694                 if (!mutex_trylock(&xprt->xpt_mutex))
2695                         return -EAGAIN;
2696                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2697         }
2698         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2699                 len = -ENOTCONN;
2700         else
2701                 len = bc_sendto(req);
2702         mutex_unlock(&xprt->xpt_mutex);
2703
2704         if (len > 0)
2705                 len = 0;
2706
2707         return len;
2708 }
2709
2710 /*
2711  * The close routine. Since this is client initiated, we do nothing
2712  */
2713
2714 static void bc_close(struct rpc_xprt *xprt)
2715 {
2716 }
2717
2718 /*
2719  * The xprt destroy routine. Again, because this connection is client
2720  * initiated, we do nothing
2721  */
2722
2723 static void bc_destroy(struct rpc_xprt *xprt)
2724 {
2725         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2726
2727         xs_xprt_free(xprt);
2728         module_put(THIS_MODULE);
2729 }
2730
2731 static const struct rpc_xprt_ops xs_local_ops = {
2732         .reserve_xprt           = xprt_reserve_xprt,
2733         .release_xprt           = xs_tcp_release_xprt,
2734         .alloc_slot             = xprt_alloc_slot,
2735         .rpcbind                = xs_local_rpcbind,
2736         .set_port               = xs_local_set_port,
2737         .connect                = xs_local_connect,
2738         .buf_alloc              = rpc_malloc,
2739         .buf_free               = rpc_free,
2740         .send_request           = xs_local_send_request,
2741         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2742         .close                  = xs_close,
2743         .destroy                = xs_destroy,
2744         .print_stats            = xs_local_print_stats,
2745         .enable_swap            = xs_enable_swap,
2746         .disable_swap           = xs_disable_swap,
2747 };
2748
2749 static const struct rpc_xprt_ops xs_udp_ops = {
2750         .set_buffer_size        = xs_udp_set_buffer_size,
2751         .reserve_xprt           = xprt_reserve_xprt_cong,
2752         .release_xprt           = xprt_release_xprt_cong,
2753         .alloc_slot             = xprt_alloc_slot,
2754         .rpcbind                = rpcb_getport_async,
2755         .set_port               = xs_set_port,
2756         .connect                = xs_connect,
2757         .buf_alloc              = rpc_malloc,
2758         .buf_free               = rpc_free,
2759         .send_request           = xs_udp_send_request,
2760         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2761         .timer                  = xs_udp_timer,
2762         .release_request        = xprt_release_rqst_cong,
2763         .close                  = xs_close,
2764         .destroy                = xs_destroy,
2765         .print_stats            = xs_udp_print_stats,
2766         .enable_swap            = xs_enable_swap,
2767         .disable_swap           = xs_disable_swap,
2768         .inject_disconnect      = xs_inject_disconnect,
2769 };
2770
2771 static const struct rpc_xprt_ops xs_tcp_ops = {
2772         .reserve_xprt           = xprt_reserve_xprt,
2773         .release_xprt           = xs_tcp_release_xprt,
2774         .alloc_slot             = xprt_lock_and_alloc_slot,
2775         .rpcbind                = rpcb_getport_async,
2776         .set_port               = xs_set_port,
2777         .connect                = xs_connect,
2778         .buf_alloc              = rpc_malloc,
2779         .buf_free               = rpc_free,
2780         .send_request           = xs_tcp_send_request,
2781         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2782         .close                  = xs_tcp_shutdown,
2783         .destroy                = xs_destroy,
2784         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2785         .print_stats            = xs_tcp_print_stats,
2786         .enable_swap            = xs_enable_swap,
2787         .disable_swap           = xs_disable_swap,
2788         .inject_disconnect      = xs_inject_disconnect,
2789 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2790         .bc_setup               = xprt_setup_bc,
2791         .bc_up                  = xs_tcp_bc_up,
2792         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2793         .bc_free_rqst           = xprt_free_bc_rqst,
2794         .bc_destroy             = xprt_destroy_bc,
2795 #endif
2796 };
2797
2798 /*
2799  * The rpc_xprt_ops for the server backchannel
2800  */
2801
2802 static const struct rpc_xprt_ops bc_tcp_ops = {
2803         .reserve_xprt           = xprt_reserve_xprt,
2804         .release_xprt           = xprt_release_xprt,
2805         .alloc_slot             = xprt_alloc_slot,
2806         .buf_alloc              = bc_malloc,
2807         .buf_free               = bc_free,
2808         .send_request           = bc_send_request,
2809         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2810         .close                  = bc_close,
2811         .destroy                = bc_destroy,
2812         .print_stats            = xs_tcp_print_stats,
2813         .enable_swap            = xs_enable_swap,
2814         .disable_swap           = xs_disable_swap,
2815         .inject_disconnect      = xs_inject_disconnect,
2816 };
2817
2818 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2819 {
2820         static const struct sockaddr_in sin = {
2821                 .sin_family             = AF_INET,
2822                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2823         };
2824         static const struct sockaddr_in6 sin6 = {
2825                 .sin6_family            = AF_INET6,
2826                 .sin6_addr              = IN6ADDR_ANY_INIT,
2827         };
2828
2829         switch (family) {
2830         case AF_LOCAL:
2831                 break;
2832         case AF_INET:
2833                 memcpy(sap, &sin, sizeof(sin));
2834                 break;
2835         case AF_INET6:
2836                 memcpy(sap, &sin6, sizeof(sin6));
2837                 break;
2838         default:
2839                 dprintk("RPC:       %s: Bad address family\n", __func__);
2840                 return -EAFNOSUPPORT;
2841         }
2842         return 0;
2843 }
2844
2845 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2846                                       unsigned int slot_table_size,
2847                                       unsigned int max_slot_table_size)
2848 {
2849         struct rpc_xprt *xprt;
2850         struct sock_xprt *new;
2851
2852         if (args->addrlen > sizeof(xprt->addr)) {
2853                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2854                 return ERR_PTR(-EBADF);
2855         }
2856
2857         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2858                         max_slot_table_size);
2859         if (xprt == NULL) {
2860                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2861                                 "rpc_xprt\n");
2862                 return ERR_PTR(-ENOMEM);
2863         }
2864
2865         new = container_of(xprt, struct sock_xprt, xprt);
2866         mutex_init(&new->recv_mutex);
2867         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2868         xprt->addrlen = args->addrlen;
2869         if (args->srcaddr)
2870                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2871         else {
2872                 int err;
2873                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2874                                         (struct sockaddr *)&new->srcaddr);
2875                 if (err != 0) {
2876                         xprt_free(xprt);
2877                         return ERR_PTR(err);
2878                 }
2879         }
2880
2881         return xprt;
2882 }
2883
2884 static const struct rpc_timeout xs_local_default_timeout = {
2885         .to_initval = 10 * HZ,
2886         .to_maxval = 10 * HZ,
2887         .to_retries = 2,
2888 };
2889
2890 /**
2891  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2892  * @args: rpc transport creation arguments
2893  *
2894  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2895  */
2896 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2897 {
2898         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2899         struct sock_xprt *transport;
2900         struct rpc_xprt *xprt;
2901         struct rpc_xprt *ret;
2902
2903         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2904                         xprt_max_tcp_slot_table_entries);
2905         if (IS_ERR(xprt))
2906                 return xprt;
2907         transport = container_of(xprt, struct sock_xprt, xprt);
2908
2909         xprt->prot = 0;
2910         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2911         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2912
2913         xprt->bind_timeout = XS_BIND_TO;
2914         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2915         xprt->idle_timeout = XS_IDLE_DISC_TO;
2916
2917         xprt->ops = &xs_local_ops;
2918         xprt->timeout = &xs_local_default_timeout;
2919
2920         INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2921         INIT_DELAYED_WORK(&transport->connect_worker,
2922                         xs_dummy_setup_socket);
2923
2924         switch (sun->sun_family) {
2925         case AF_LOCAL:
2926                 if (sun->sun_path[0] != '/') {
2927                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2928                                         sun->sun_path);
2929                         ret = ERR_PTR(-EINVAL);
2930                         goto out_err;
2931                 }
2932                 xprt_set_bound(xprt);
2933                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2934                 ret = ERR_PTR(xs_local_setup_socket(transport));
2935                 if (ret)
2936                         goto out_err;
2937                 break;
2938         default:
2939                 ret = ERR_PTR(-EAFNOSUPPORT);
2940                 goto out_err;
2941         }
2942
2943         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2944                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2945
2946         if (try_module_get(THIS_MODULE))
2947                 return xprt;
2948         ret = ERR_PTR(-EINVAL);
2949 out_err:
2950         xs_xprt_free(xprt);
2951         return ret;
2952 }
2953
2954 static const struct rpc_timeout xs_udp_default_timeout = {
2955         .to_initval = 5 * HZ,
2956         .to_maxval = 30 * HZ,
2957         .to_increment = 5 * HZ,
2958         .to_retries = 5,
2959 };
2960
2961 /**
2962  * xs_setup_udp - Set up transport to use a UDP socket
2963  * @args: rpc transport creation arguments
2964  *
2965  */
2966 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2967 {
2968         struct sockaddr *addr = args->dstaddr;
2969         struct rpc_xprt *xprt;
2970         struct sock_xprt *transport;
2971         struct rpc_xprt *ret;
2972
2973         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2974                         xprt_udp_slot_table_entries);
2975         if (IS_ERR(xprt))
2976                 return xprt;
2977         transport = container_of(xprt, struct sock_xprt, xprt);
2978
2979         xprt->prot = IPPROTO_UDP;
2980         xprt->tsh_size = 0;
2981         /* XXX: header size can vary due to auth type, IPv6, etc. */
2982         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2983
2984         xprt->bind_timeout = XS_BIND_TO;
2985         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2986         xprt->idle_timeout = XS_IDLE_DISC_TO;
2987
2988         xprt->ops = &xs_udp_ops;
2989
2990         xprt->timeout = &xs_udp_default_timeout;
2991
2992         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2993         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2994
2995         switch (addr->sa_family) {
2996         case AF_INET:
2997                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2998                         xprt_set_bound(xprt);
2999
3000                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
3001                 break;
3002         case AF_INET6:
3003                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3004                         xprt_set_bound(xprt);
3005
3006                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
3007                 break;
3008         default:
3009                 ret = ERR_PTR(-EAFNOSUPPORT);
3010                 goto out_err;
3011         }
3012
3013         if (xprt_bound(xprt))
3014                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3015                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3016                                 xprt->address_strings[RPC_DISPLAY_PORT],
3017                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3018         else
3019                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3020                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3021                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3022
3023         if (try_module_get(THIS_MODULE))
3024                 return xprt;
3025         ret = ERR_PTR(-EINVAL);
3026 out_err:
3027         xs_xprt_free(xprt);
3028         return ret;
3029 }
3030
3031 static const struct rpc_timeout xs_tcp_default_timeout = {
3032         .to_initval = 60 * HZ,
3033         .to_maxval = 60 * HZ,
3034         .to_retries = 2,
3035 };
3036
3037 /**
3038  * xs_setup_tcp - Set up transport to use a TCP socket
3039  * @args: rpc transport creation arguments
3040  *
3041  */
3042 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
3043 {
3044         struct sockaddr *addr = args->dstaddr;
3045         struct rpc_xprt *xprt;
3046         struct sock_xprt *transport;
3047         struct rpc_xprt *ret;
3048         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3049
3050         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3051                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3052
3053         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3054                         max_slot_table_size);
3055         if (IS_ERR(xprt))
3056                 return xprt;
3057         transport = container_of(xprt, struct sock_xprt, xprt);
3058
3059         xprt->prot = IPPROTO_TCP;
3060         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3061         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3062
3063         xprt->bind_timeout = XS_BIND_TO;
3064         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3065         xprt->idle_timeout = XS_IDLE_DISC_TO;
3066
3067         xprt->ops = &xs_tcp_ops;
3068         xprt->timeout = &xs_tcp_default_timeout;
3069
3070         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3071         xprt->connect_timeout = xprt->timeout->to_initval *
3072                 (xprt->timeout->to_retries + 1);
3073
3074         INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
3075         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3076
3077         switch (addr->sa_family) {
3078         case AF_INET:
3079                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3080                         xprt_set_bound(xprt);
3081
3082                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3083                 break;
3084         case AF_INET6:
3085                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3086                         xprt_set_bound(xprt);
3087
3088                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3089                 break;
3090         default:
3091                 ret = ERR_PTR(-EAFNOSUPPORT);
3092                 goto out_err;
3093         }
3094
3095         if (xprt_bound(xprt))
3096                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3097                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3098                                 xprt->address_strings[RPC_DISPLAY_PORT],
3099                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3100         else
3101                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3102                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3103                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3104
3105         if (try_module_get(THIS_MODULE))
3106                 return xprt;
3107         ret = ERR_PTR(-EINVAL);
3108 out_err:
3109         xs_xprt_free(xprt);
3110         return ret;
3111 }
3112
3113 /**
3114  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3115  * @args: rpc transport creation arguments
3116  *
3117  */
3118 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3119 {
3120         struct sockaddr *addr = args->dstaddr;
3121         struct rpc_xprt *xprt;
3122         struct sock_xprt *transport;
3123         struct svc_sock *bc_sock;
3124         struct rpc_xprt *ret;
3125
3126         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3127                         xprt_tcp_slot_table_entries);
3128         if (IS_ERR(xprt))
3129                 return xprt;
3130         transport = container_of(xprt, struct sock_xprt, xprt);
3131
3132         xprt->prot = IPPROTO_TCP;
3133         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3134         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3135         xprt->timeout = &xs_tcp_default_timeout;
3136
3137         /* backchannel */
3138         xprt_set_bound(xprt);
3139         xprt->bind_timeout = 0;
3140         xprt->reestablish_timeout = 0;
3141         xprt->idle_timeout = 0;
3142
3143         xprt->ops = &bc_tcp_ops;
3144
3145         switch (addr->sa_family) {
3146         case AF_INET:
3147                 xs_format_peer_addresses(xprt, "tcp",
3148                                          RPCBIND_NETID_TCP);
3149                 break;
3150         case AF_INET6:
3151                 xs_format_peer_addresses(xprt, "tcp",
3152                                    RPCBIND_NETID_TCP6);
3153                 break;
3154         default:
3155                 ret = ERR_PTR(-EAFNOSUPPORT);
3156                 goto out_err;
3157         }
3158
3159         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3160                         xprt->address_strings[RPC_DISPLAY_ADDR],
3161                         xprt->address_strings[RPC_DISPLAY_PORT],
3162                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3163
3164         /*
3165          * Once we've associated a backchannel xprt with a connection,
3166          * we want to keep it around as long as the connection lasts,
3167          * in case we need to start using it for a backchannel again;
3168          * this reference won't be dropped until bc_xprt is destroyed.
3169          */
3170         xprt_get(xprt);
3171         args->bc_xprt->xpt_bc_xprt = xprt;
3172         xprt->bc_xprt = args->bc_xprt;
3173         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3174         transport->sock = bc_sock->sk_sock;
3175         transport->inet = bc_sock->sk_sk;
3176
3177         /*
3178          * Since we don't want connections for the backchannel, we set
3179          * the xprt status to connected
3180          */
3181         xprt_set_connected(xprt);
3182
3183         if (try_module_get(THIS_MODULE))
3184                 return xprt;
3185
3186         args->bc_xprt->xpt_bc_xprt = NULL;
3187         args->bc_xprt->xpt_bc_xps = NULL;
3188         xprt_put(xprt);
3189         ret = ERR_PTR(-EINVAL);
3190 out_err:
3191         xs_xprt_free(xprt);
3192         return ret;
3193 }
3194
3195 static struct xprt_class        xs_local_transport = {
3196         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3197         .name           = "named UNIX socket",
3198         .owner          = THIS_MODULE,
3199         .ident          = XPRT_TRANSPORT_LOCAL,
3200         .setup          = xs_setup_local,
3201 };
3202
3203 static struct xprt_class        xs_udp_transport = {
3204         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3205         .name           = "udp",
3206         .owner          = THIS_MODULE,
3207         .ident          = XPRT_TRANSPORT_UDP,
3208         .setup          = xs_setup_udp,
3209 };
3210
3211 static struct xprt_class        xs_tcp_transport = {
3212         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3213         .name           = "tcp",
3214         .owner          = THIS_MODULE,
3215         .ident          = XPRT_TRANSPORT_TCP,
3216         .setup          = xs_setup_tcp,
3217 };
3218
3219 static struct xprt_class        xs_bc_tcp_transport = {
3220         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3221         .name           = "tcp NFSv4.1 backchannel",
3222         .owner          = THIS_MODULE,
3223         .ident          = XPRT_TRANSPORT_BC_TCP,
3224         .setup          = xs_setup_bc_tcp,
3225 };
3226
3227 /**
3228  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3229  *
3230  */
3231 int init_socket_xprt(void)
3232 {
3233 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3234         if (!sunrpc_table_header)
3235                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3236 #endif
3237
3238         xprt_register_transport(&xs_local_transport);
3239         xprt_register_transport(&xs_udp_transport);
3240         xprt_register_transport(&xs_tcp_transport);
3241         xprt_register_transport(&xs_bc_tcp_transport);
3242
3243         return 0;
3244 }
3245
3246 /**
3247  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3248  *
3249  */
3250 void cleanup_socket_xprt(void)
3251 {
3252 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3253         if (sunrpc_table_header) {
3254                 unregister_sysctl_table(sunrpc_table_header);
3255                 sunrpc_table_header = NULL;
3256         }
3257 #endif
3258
3259         xprt_unregister_transport(&xs_local_transport);
3260         xprt_unregister_transport(&xs_udp_transport);
3261         xprt_unregister_transport(&xs_tcp_transport);
3262         xprt_unregister_transport(&xs_bc_tcp_transport);
3263 }
3264
3265 static int param_set_uint_minmax(const char *val,
3266                 const struct kernel_param *kp,
3267                 unsigned int min, unsigned int max)
3268 {
3269         unsigned int num;
3270         int ret;
3271
3272         if (!val)
3273                 return -EINVAL;
3274         ret = kstrtouint(val, 0, &num);
3275         if (ret)
3276                 return ret;
3277         if (num < min || num > max)
3278                 return -EINVAL;
3279         *((unsigned int *)kp->arg) = num;
3280         return 0;
3281 }
3282
3283 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3284 {
3285         if (kp->arg == &xprt_min_resvport)
3286                 return param_set_uint_minmax(val, kp,
3287                         RPC_MIN_RESVPORT,
3288                         xprt_max_resvport);
3289         return param_set_uint_minmax(val, kp,
3290                         xprt_min_resvport,
3291                         RPC_MAX_RESVPORT);
3292 }
3293
3294 static const struct kernel_param_ops param_ops_portnr = {
3295         .set = param_set_portnr,
3296         .get = param_get_uint,
3297 };
3298
3299 #define param_check_portnr(name, p) \
3300         __param_check(name, p, unsigned int);
3301
3302 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3303 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3304
3305 static int param_set_slot_table_size(const char *val,
3306                                      const struct kernel_param *kp)
3307 {
3308         return param_set_uint_minmax(val, kp,
3309                         RPC_MIN_SLOT_TABLE,
3310                         RPC_MAX_SLOT_TABLE);
3311 }
3312
3313 static const struct kernel_param_ops param_ops_slot_table_size = {
3314         .set = param_set_slot_table_size,
3315         .get = param_get_uint,
3316 };
3317
3318 #define param_check_slot_table_size(name, p) \
3319         __param_check(name, p, unsigned int);
3320
3321 static int param_set_max_slot_table_size(const char *val,
3322                                      const struct kernel_param *kp)
3323 {
3324         return param_set_uint_minmax(val, kp,
3325                         RPC_MIN_SLOT_TABLE,
3326                         RPC_MAX_SLOT_TABLE_LIMIT);
3327 }
3328
3329 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3330         .set = param_set_max_slot_table_size,
3331         .get = param_get_uint,
3332 };
3333
3334 #define param_check_max_slot_table_size(name, p) \
3335         __param_check(name, p, unsigned int);
3336
3337 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3338                    slot_table_size, 0644);
3339 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3340                    max_slot_table_size, 0644);
3341 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3342                    slot_table_size, 0644);
3343