net/sunrpc/xprtsock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/net/sunrpc/xprtsock.c
   4  *
   5  * Client-side transport implementation for sockets.
   6  *
   7  * TCP callback races fixes (C) 1998 Red Hat
   8  * TCP send fixes (C) 1998 Red Hat
   9  * TCP NFS related read + write fixes
  10  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
  11  *
  12  * Rewrite of larges part of the code in order to stabilize TCP stuff.
  13  * Fix behaviour when socket buffer is full.
  14  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  15  *
  16  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
  17  *
  18  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
  19  *   <gilles.quillard@bull.net>
  20  */
  21
  22 #include <linux/types.h>
  23 #include <linux/string.h>
  24 #include <linux/slab.h>
  25 #include <linux/module.h>
  26 #include <linux/capability.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/errno.h>
  29 #include <linux/socket.h>
  30 #include <linux/in.h>
  31 #include <linux/net.h>
  32 #include <linux/mm.h>
  33 #include <linux/un.h>
  34 #include <linux/udp.h>
  35 #include <linux/tcp.h>
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/sched.h>
  39 #include <linux/sunrpc/svcsock.h>
  40 #include <linux/sunrpc/xprtsock.h>
  41 #include <linux/file.h>
  42 #ifdef CONFIG_SUNRPC_BACKCHANNEL
  43 #include <linux/sunrpc/bc_xprt.h>
  44 #endif
  45
  46 #include <net/sock.h>
  47 #include <net/checksum.h>
  48 #include <net/udp.h>
  49 #include <net/tcp.h>
  50
  51 #include <trace/events/sunrpc.h>
  52
  53 #include "sunrpc.h"
  54
  55 static void xs_close(struct rpc_xprt *xprt);
  56 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
  57                 struct socket *sock);
  58
  59 /*
  60  * xprtsock tunables
  61  */
  62 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  63 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
  64 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
  65
  66 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  67 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  68
  69 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  70
  71 #define XS_TCP_LINGER_TO        (15U * HZ)
  72 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  73
  74 /*
  75  * We can register our own files under /proc/sys/sunrpc by
  76  * calling register_sysctl_table() again.  The files in that
  77  * directory become the union of all files registered there.
  78  *
  79  * We simply need to make sure that we don't collide with
  80  * someone else's file names!
  81  */
  82
  83 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  84 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  85 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
  86 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  87 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  88
  89 static struct ctl_table_header *sunrpc_table_header;
  90
  91 /*
  92  * FIXME: changing the UDP slot table size should also resize the UDP
  93  *        socket buffers for existing UDP transports
  94  */
  95 static struct ctl_table xs_tunables_table[] = {
  96         {
  97                 .procname       = "udp_slot_table_entries",
  98                 .data           = &xprt_udp_slot_table_entries,
  99                 .maxlen         = sizeof(unsigned int),
 100                 .mode           = 0644,
 101                 .proc_handler   = proc_dointvec_minmax,
 102                 .extra1         = &min_slot_table_size,
 103                 .extra2         = &max_slot_table_size
 104         },
 105         {
 106                 .procname       = "tcp_slot_table_entries",
 107                 .data           = &xprt_tcp_slot_table_entries,
 108                 .maxlen         = sizeof(unsigned int),
 109                 .mode           = 0644,
 110                 .proc_handler   = proc_dointvec_minmax,
 111                 .extra1         = &min_slot_table_size,
 112                 .extra2         = &max_slot_table_size
 113         },
 114         {
 115                 .procname       = "tcp_max_slot_table_entries",
 116                 .data           = &xprt_max_tcp_slot_table_entries,
 117                 .maxlen         = sizeof(unsigned int),
 118                 .mode           = 0644,
 119                 .proc_handler   = proc_dointvec_minmax,
 120                 .extra1         = &min_slot_table_size,
 121                 .extra2         = &max_tcp_slot_table_limit
 122         },
 123         {
 124                 .procname       = "min_resvport",
 125                 .data           = &xprt_min_resvport,
 126                 .maxlen         = sizeof(unsigned int),
 127                 .mode           = 0644,
 128                 .proc_handler   = proc_dointvec_minmax,
 129                 .extra1         = &xprt_min_resvport_limit,
 130                 .extra2         = &xprt_max_resvport
 131         },
 132         {
 133                 .procname       = "max_resvport",
 134                 .data           = &xprt_max_resvport,
 135                 .maxlen         = sizeof(unsigned int),
 136                 .mode           = 0644,
 137                 .proc_handler   = proc_dointvec_minmax,
 138                 .extra1         = &xprt_min_resvport,
 139                 .extra2         = &xprt_max_resvport_limit
 140         },
 141         {
 142                 .procname       = "tcp_fin_timeout",
 143                 .data           = &xs_tcp_fin_timeout,
 144                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 145                 .mode           = 0644,
 146                 .proc_handler   = proc_dointvec_jiffies,
 147         },
 148         { },
 149 };
 150
 151 static struct ctl_table sunrpc_table[] = {
 152         {
 153                 .procname       = "sunrpc",
 154                 .mode           = 0555,
 155                 .child          = xs_tunables_table
 156         },
 157         { },
 158 };
 159
 160 #endif
 161
 162 /*
 163  * Wait duration for a reply from the RPC portmapper.
 164  */
 165 #define XS_BIND_TO              (60U * HZ)
 166
 167 /*
 168  * Delay if a UDP socket connect error occurs.  This is most likely some
 169  * kind of resource problem on the local host.
 170  */
 171 #define XS_UDP_REEST_TO         (2U * HZ)
 172
 173 /*
 174  * The reestablish timeout allows clients to delay for a bit before attempting
 175  * to reconnect to a server that just dropped our connection.
 176  *
 177  * We implement an exponential backoff when trying to reestablish a TCP
 178  * transport connection with the server.  Some servers like to drop a TCP
 179  * connection when they are overworked, so we start with a short timeout and
 180  * increase over time if the server is down or not responding.
 181  */
 182 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 183
 184 /*
 185  * TCP idle timeout; client drops the transport socket if it is idle
 186  * for this long.  Note that we also timeout UDP sockets to prevent
 187  * holding port numbers when there is no RPC traffic.
 188  */
 189 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 190
 191 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 192 # undef  RPC_DEBUG_DATA
 193 # define RPCDBG_FACILITY        RPCDBG_TRANS
 194 #endif
 195
 196 #ifdef RPC_DEBUG_DATA
 197 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 198 {
 199         u8 *buf = (u8 *) packet;
 200         int j;
 201
 202         dprintk("RPC:       %s\n", msg);
 203         for (j = 0; j < count && j < 128; j += 4) {
 204                 if (!(j & 31)) {
 205                         if (j)
 206                                 dprintk("\n");
 207                         dprintk("0x%04x ", j);
 208                 }
 209                 dprintk("%02x%02x%02x%02x ",
 210                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 211         }
 212         dprintk("\n");
 213 }
 214 #else
 215 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 216 {
 217         /* NOP */
 218 }
 219 #endif
 220
 221 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 222 {
 223         return (struct rpc_xprt *) sk->sk_user_data;
 224 }
 225
 226 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 227 {
 228         return (struct sockaddr *) &xprt->addr;
 229 }
 230
 231 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
 232 {
 233         return (struct sockaddr_un *) &xprt->addr;
 234 }
 235
 236 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 237 {
 238         return (struct sockaddr_in *) &xprt->addr;
 239 }
 240
 241 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 242 {
 243         return (struct sockaddr_in6 *) &xprt->addr;
 244 }
 245
 246 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 247 {
 248         struct sockaddr *sap = xs_addr(xprt);
 249         struct sockaddr_in6 *sin6;
 250         struct sockaddr_in *sin;
 251         struct sockaddr_un *sun;
 252         char buf[128];
 253
 254         switch (sap->sa_family) {
 255         case AF_LOCAL:
 256                 sun = xs_addr_un(xprt);
 257                 strlcpy(buf, sun->sun_path, sizeof(buf));
 258                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 259                                                 kstrdup(buf, GFP_KERNEL);
 260                 break;
 261         case AF_INET:
 262                 (void)rpc_ntop(sap, buf, sizeof(buf));
 263                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 264                                                 kstrdup(buf, GFP_KERNEL);
 265                 sin = xs_addr_in(xprt);
 266                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 267                 break;
 268         case AF_INET6:
 269                 (void)rpc_ntop(sap, buf, sizeof(buf));
 270                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 271                                                 kstrdup(buf, GFP_KERNEL);
 272                 sin6 = xs_addr_in6(xprt);
 273                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 274                 break;
 275         default:
 276                 BUG();
 277         }
 278
 279         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 280 }
 281
 282 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 283 {
 284         struct sockaddr *sap = xs_addr(xprt);
 285         char buf[128];
 286
 287         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 288         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 289
 290         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 291         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 292 }
 293
 294 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 295                                      const char *protocol,
 296                                      const char *netid)
 297 {
 298         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 299         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 300         xs_format_common_peer_addresses(xprt);
 301         xs_format_common_peer_ports(xprt);
 302 }
 303
 304 static void xs_update_peer_port(struct rpc_xprt *xprt)
 305 {
 306         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 307         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 308
 309         xs_format_common_peer_ports(xprt);
 310 }
 311
 312 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 313 {
 314         unsigned int i;
 315
 316         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 317                 switch (i) {
 318                 case RPC_DISPLAY_PROTO:
 319                 case RPC_DISPLAY_NETID:
 320                         continue;
 321                 default:
 322                         kfree(xprt->address_strings[i]);
 323                 }
 324 }
 325
 326 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 327
 328 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
 329 {
 330         struct msghdr msg = {
 331                 .msg_name       = addr,
 332                 .msg_namelen    = addrlen,
 333                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
 334         };
 335         struct kvec iov = {
 336                 .iov_base       = vec->iov_base + base,
 337                 .iov_len        = vec->iov_len - base,
 338         };
 339
 340         if (iov.iov_len != 0)
 341                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 342         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 343 }
 344
 345 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
 346 {
 347         ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
 348                         int offset, size_t size, int flags);
 349         struct page **ppage;
 350         unsigned int remainder;
 351         int err;
 352
 353         remainder = xdr->page_len - base;
 354         base += xdr->page_base;
 355         ppage = xdr->pages + (base >> PAGE_SHIFT);
 356         base &= ~PAGE_MASK;
 357         do_sendpage = sock->ops->sendpage;
 358         if (!zerocopy)
 359                 do_sendpage = sock_no_sendpage;
 360         for(;;) {
 361                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
 362                 int flags = XS_SENDMSG_FLAGS;
 363
 364                 remainder -= len;
 365                 if (more)
 366                         flags |= MSG_MORE;
 367                 if (remainder != 0)
 368                         flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
 369                 err = do_sendpage(sock, *ppage, base, len, flags);
 370                 if (remainder == 0 || err != len)
 371                         break;
 372                 *sent_p += err;
 373                 ppage++;
 374                 base = 0;
 375         }
 376         if (err > 0) {
 377                 *sent_p += err;
 378                 err = 0;
 379         }
 380         return err;
 381 }
 382
 383 /**
 384  * xs_sendpages - write pages directly to a socket
 385  * @sock: socket to send on
 386  * @addr: UDP only -- address of destination
 387  * @addrlen: UDP only -- length of destination address
 388  * @xdr: buffer containing this request
 389  * @base: starting position in the buffer
 390  * @zerocopy: true if it is safe to use sendpage()
 391  * @sent_p: return the total number of bytes successfully queued for sending
 392  *
 393  */
 394 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
 395 {
 396         unsigned int remainder = xdr->len - base;
 397         int err = 0;
 398         int sent = 0;
 399
 400         if (unlikely(!sock))
 401                 return -ENOTSOCK;
 402
 403         if (base != 0) {
 404                 addr = NULL;
 405                 addrlen = 0;
 406         }
 407
 408         if (base < xdr->head[0].iov_len || addr != NULL) {
 409                 unsigned int len = xdr->head[0].iov_len - base;
 410                 remainder -= len;
 411                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
 412                 if (remainder == 0 || err != len)
 413                         goto out;
 414                 *sent_p += err;
 415                 base = 0;
 416         } else
 417                 base -= xdr->head[0].iov_len;
 418
 419         if (base < xdr->page_len) {
 420                 unsigned int len = xdr->page_len - base;
 421                 remainder -= len;
 422                 err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
 423                 *sent_p += sent;
 424                 if (remainder == 0 || sent != len)
 425                         goto out;
 426                 base = 0;
 427         } else
 428                 base -= xdr->page_len;
 429
 430         if (base >= xdr->tail[0].iov_len)
 431                 return 0;
 432         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
 433 out:
 434         if (err > 0) {
 435                 *sent_p += err;
 436                 err = 0;
 437         }
 438         return err;
 439 }
 440
 441 static void xs_nospace_callback(struct rpc_task *task)
 442 {
 443         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 444
 445         transport->inet->sk_write_pending--;
 446 }
 447
 448 /**
 449  * xs_nospace - place task on wait queue if transmit was incomplete
 450  * @task: task to put to sleep
 451  *
 452  */
 453 static int xs_nospace(struct rpc_task *task)
 454 {
 455         struct rpc_rqst *req = task->tk_rqstp;
 456         struct rpc_xprt *xprt = req->rq_xprt;
 457         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 458         struct sock *sk = transport->inet;
 459         int ret = -EAGAIN;
 460
 461         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 462                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 463                         req->rq_slen);
 464
 465         /* Protect against races with write_space */
 466         spin_lock_bh(&xprt->transport_lock);
 467
 468         /* Don't race with disconnect */
 469         if (xprt_connected(xprt)) {
 470                 /* wait for more buffer space */
 471                 sk->sk_write_pending++;
 472                 xprt_wait_for_buffer_space(task, xs_nospace_callback);
 473         } else
 474                 ret = -ENOTCONN;
 475
 476         spin_unlock_bh(&xprt->transport_lock);
 477
 478         /* Race breaker in case memory is freed before above code is called */
 479         if (ret == -EAGAIN) {
 480                 struct socket_wq *wq;
 481
 482                 rcu_read_lock();
 483                 wq = rcu_dereference(sk->sk_wq);
 484                 set_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags);
 485                 rcu_read_unlock();
 486
 487                 sk->sk_write_space(sk);
 488         }
 489         return ret;
 490 }
 491
 492 /*
 493  * Construct a stream transport record marker in @buf.
 494  */
 495 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
 496 {
 497         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 498         rpc_fraghdr *base = buf->head[0].iov_base;
 499         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
 500 }
 501
 502 /**
 503  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 504  * @task: RPC task that manages the state of an RPC request
 505  *
 506  * Return values:
 507  *        0:    The request has been sent
 508  *   EAGAIN:    The socket was blocked, please call again later to
 509  *              complete the request
 510  * ENOTCONN:    Caller needs to invoke connect logic then call again
 511  *    other:    Some other error occured, the request was not sent
 512  */
 513 static int xs_local_send_request(struct rpc_task *task)
 514 {
 515         struct rpc_rqst *req = task->tk_rqstp;
 516         struct rpc_xprt *xprt = req->rq_xprt;
 517         struct sock_xprt *transport =
 518                                 container_of(xprt, struct sock_xprt, xprt);
 519         struct xdr_buf *xdr = &req->rq_snd_buf;
 520         int status;
 521         int sent = 0;
 522
 523         xs_encode_stream_record_marker(&req->rq_snd_buf);
 524
 525         xs_pktdump("packet data:",
 526                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 527
 528         status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
 529                               true, &sent);
 530         dprintk("RPC:       %s(%u) = %d\n",
 531                         __func__, xdr->len - req->rq_bytes_sent, status);
 532
 533         if (status == -EAGAIN && sock_writeable(transport->inet))
 534                 status = -ENOBUFS;
 535
 536         if (likely(sent > 0) || status == 0) {
 537                 req->rq_bytes_sent += sent;
 538                 req->rq_xmit_bytes_sent += sent;
 539                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 540                         req->rq_bytes_sent = 0;
 541                         return 0;
 542                 }
 543                 status = -EAGAIN;
 544         }
 545
 546         switch (status) {
 547         case -ENOBUFS:
 548                 break;
 549         case -EAGAIN:
 550                 status = xs_nospace(task);
 551                 break;
 552         default:
 553                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 554                         -status);
 555         case -EPIPE:
 556                 xs_close(xprt);
 557                 status = -ENOTCONN;
 558         }
 559
 560         return status;
 561 }
 562
 563 /**
 564  * xs_udp_send_request - write an RPC request to a UDP socket
 565  * @task: address of RPC task that manages the state of an RPC request
 566  *
 567  * Return values:
 568  *        0:    The request has been sent
 569  *   EAGAIN:    The socket was blocked, please call again later to
 570  *              complete the request
 571  * ENOTCONN:    Caller needs to invoke connect logic then call again
 572  *    other:    Some other error occurred, the request was not sent
 573  */
 574 static int xs_udp_send_request(struct rpc_task *task)
 575 {
 576         struct rpc_rqst *req = task->tk_rqstp;
 577         struct rpc_xprt *xprt = req->rq_xprt;
 578         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 579         struct xdr_buf *xdr = &req->rq_snd_buf;
 580         int sent = 0;
 581         int status;
 582
 583         xs_pktdump("packet data:",
 584                                 req->rq_svec->iov_base,
 585                                 req->rq_svec->iov_len);
 586
 587         if (!xprt_bound(xprt))
 588                 return -ENOTCONN;
 589         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
 590                               xdr, req->rq_bytes_sent, true, &sent);
 591
 592         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 593                         xdr->len - req->rq_bytes_sent, status);
 594
 595         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
 596         if (status == -EPERM)
 597                 goto process_status;
 598
 599         if (status == -EAGAIN && sock_writeable(transport->inet))
 600                 status = -ENOBUFS;
 601
 602         if (sent > 0 || status == 0) {
 603                 req->rq_xmit_bytes_sent += sent;
 604                 if (sent >= req->rq_slen)
 605                         return 0;
 606                 /* Still some bytes left; set up for a retry later. */
 607                 status = -EAGAIN;
 608         }
 609
 610 process_status:
 611         switch (status) {
 612         case -ENOTSOCK:
 613                 status = -ENOTCONN;
 614                 /* Should we call xs_close() here? */
 615                 break;
 616         case -EAGAIN:
 617                 status = xs_nospace(task);
 618                 break;
 619         case -ENETUNREACH:
 620         case -ENOBUFS:
 621         case -EPIPE:
 622         case -ECONNREFUSED:
 623         case -EPERM:
 624                 /* When the server has died, an ICMP port unreachable message
 625                  * prompts ECONNREFUSED. */
 626                 break;
 627         default:
 628                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 629                         -status);
 630         }
 631
 632         return status;
 633 }
 634
 635 /**
 636  * xs_tcp_send_request - write an RPC request to a TCP socket
 637  * @task: address of RPC task that manages the state of an RPC request
 638  *
 639  * Return values:
 640  *        0:    The request has been sent
 641  *   EAGAIN:    The socket was blocked, please call again later to
 642  *              complete the request
 643  * ENOTCONN:    Caller needs to invoke connect logic then call again
 644  *    other:    Some other error occurred, the request was not sent
 645  *
 646  * XXX: In the case of soft timeouts, should we eventually give up
 647  *      if sendmsg is not able to make progress?
 648  */
 649 static int xs_tcp_send_request(struct rpc_task *task)
 650 {
 651         struct rpc_rqst *req = task->tk_rqstp;
 652         struct rpc_xprt *xprt = req->rq_xprt;
 653         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 654         struct xdr_buf *xdr = &req->rq_snd_buf;
 655         bool zerocopy = true;
 656         bool vm_wait = false;
 657         int status;
 658         int sent;
 659
 660         xs_encode_stream_record_marker(&req->rq_snd_buf);
 661
 662         xs_pktdump("packet data:",
 663                                 req->rq_svec->iov_base,
 664                                 req->rq_svec->iov_len);
 665         /* Don't use zero copy if this is a resend. If the RPC call
 666          * completes while the socket holds a reference to the pages,
 667          * then we may end up resending corrupted data.
 668          */
 669         if (task->tk_flags & RPC_TASK_SENT)
 670                 zerocopy = false;
 671
 672         if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
 673                 xs_tcp_set_socket_timeouts(xprt, transport->sock);
 674
 675         /* Continue transmitting the packet/record. We must be careful
 676          * to cope with writespace callbacks arriving _after_ we have
 677          * called sendmsg(). */
 678         while (1) {
 679                 sent = 0;
 680                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
 681                                       req->rq_bytes_sent, zerocopy, &sent);
 682
 683                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 684                                 xdr->len - req->rq_bytes_sent, status);
 685
 686                 /* If we've sent the entire packet, immediately
 687                  * reset the count of bytes sent. */
 688                 req->rq_bytes_sent += sent;
 689                 req->rq_xmit_bytes_sent += sent;
 690                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 691                         req->rq_bytes_sent = 0;
 692                         return 0;
 693                 }
 694
 695                 WARN_ON_ONCE(sent == 0 && status == 0);
 696
 697                 if (status == -EAGAIN ) {
 698                         /*
 699                          * Return EAGAIN if we're sure we're hitting the
 700                          * socket send buffer limits.
 701                          */
 702                         if (test_bit(SOCK_NOSPACE, &transport->sock->flags))
 703                                 break;
 704                         /*
 705                          * Did we hit a memory allocation failure?
 706                          */
 707                         if (sent == 0) {
 708                                 status = -ENOBUFS;
 709                                 if (vm_wait)
 710                                         break;
 711                                 /* Retry, knowing now that we're below the
 712                                  * socket send buffer limit
 713                                  */
 714                                 vm_wait = true;
 715                         }
 716                         continue;
 717                 }
 718                 if (status < 0)
 719                         break;
 720                 vm_wait = false;
 721         }
 722
 723         switch (status) {
 724         case -ENOTSOCK:
 725                 status = -ENOTCONN;
 726                 /* Should we call xs_close() here? */
 727                 break;
 728         case -EAGAIN:
 729                 status = xs_nospace(task);
 730                 break;
 731         case -ECONNRESET:
 732         case -ECONNREFUSED:
 733         case -ENOTCONN:
 734         case -EADDRINUSE:
 735         case -ENOBUFS:
 736         case -EPIPE:
 737                 break;
 738         default:
 739                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 740                         -status);
 741         }
 742
 743         return status;
 744 }
 745
 746 /**
 747  * xs_tcp_release_xprt - clean up after a tcp transmission
 748  * @xprt: transport
 749  * @task: rpc task
 750  *
 751  * This cleans up if an error causes us to abort the transmission of a request.
 752  * In this case, the socket may need to be reset in order to avoid confusing
 753  * the server.
 754  */
 755 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 756 {
 757         struct rpc_rqst *req;
 758
 759         if (task != xprt->snd_task)
 760                 return;
 761         if (task == NULL)
 762                 goto out_release;
 763         req = task->tk_rqstp;
 764         if (req == NULL)
 765                 goto out_release;
 766         if (req->rq_bytes_sent == 0)
 767                 goto out_release;
 768         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 769                 goto out_release;
 770         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 771 out_release:
 772         xprt_release_xprt(xprt, task);
 773 }
 774
 775 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 776 {
 777         transport->old_data_ready = sk->sk_data_ready;
 778         transport->old_state_change = sk->sk_state_change;
 779         transport->old_write_space = sk->sk_write_space;
 780         transport->old_error_report = sk->sk_error_report;
 781 }
 782
 783 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 784 {
 785         sk->sk_data_ready = transport->old_data_ready;
 786         sk->sk_state_change = transport->old_state_change;
 787         sk->sk_write_space = transport->old_write_space;
 788         sk->sk_error_report = transport->old_error_report;
 789 }
 790
 791 static void xs_sock_reset_state_flags(struct rpc_xprt *xprt)
 792 {
 793         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 794
 795         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
 796 }
 797
 798 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
 799 {
 800         smp_mb__before_atomic();
 801         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 802         clear_bit(XPRT_CLOSING, &xprt->state);
 803         xs_sock_reset_state_flags(xprt);
 804         smp_mb__after_atomic();
 805 }
 806
 807 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
 808 {
 809         xs_sock_reset_connection_flags(xprt);
 810         /* Mark transport as closed and wake up all pending tasks */
 811         xprt_disconnect_done(xprt);
 812 }
 813
 814 /**
 815  * xs_error_report - callback to handle TCP socket state errors
 816  * @sk: socket
 817  *
 818  * Note: we don't call sock_error() since there may be a rpc_task
 819  * using the socket, and so we don't want to clear sk->sk_err.
 820  */
 821 static void xs_error_report(struct sock *sk)
 822 {
 823         struct rpc_xprt *xprt;
 824         int err;
 825
 826         read_lock_bh(&sk->sk_callback_lock);
 827         if (!(xprt = xprt_from_sock(sk)))
 828                 goto out;
 829
 830         err = -sk->sk_err;
 831         if (err == 0)
 832                 goto out;
 833         /* Is this a reset event? */
 834         if (sk->sk_state == TCP_CLOSE)
 835                 xs_sock_mark_closed(xprt);
 836         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 837                         xprt, -err);
 838         trace_rpc_socket_error(xprt, sk->sk_socket, err);
 839         xprt_wake_pending_tasks(xprt, err);
 840  out:
 841         read_unlock_bh(&sk->sk_callback_lock);
 842 }
 843
 844 static void xs_reset_transport(struct sock_xprt *transport)
 845 {
 846         struct socket *sock = transport->sock;
 847         struct sock *sk = transport->inet;
 848         struct rpc_xprt *xprt = &transport->xprt;
 849
 850         if (sk == NULL)
 851                 return;
 852
 853         if (atomic_read(&transport->xprt.swapper))
 854                 sk_clear_memalloc(sk);
 855
 856         kernel_sock_shutdown(sock, SHUT_RDWR);
 857
 858         mutex_lock(&transport->recv_mutex);
 859         write_lock_bh(&sk->sk_callback_lock);
 860         transport->inet = NULL;
 861         transport->sock = NULL;
 862
 863         sk->sk_user_data = NULL;
 864
 865         xs_restore_old_callbacks(transport, sk);
 866         xprt_clear_connected(xprt);
 867         write_unlock_bh(&sk->sk_callback_lock);
 868         xs_sock_reset_connection_flags(xprt);
 869         mutex_unlock(&transport->recv_mutex);
 870
 871         trace_rpc_socket_close(xprt, sock);
 872         sock_release(sock);
 873 }
 874
 875 /**
 876  * xs_close - close a socket
 877  * @xprt: transport
 878  *
 879  * This is used when all requests are complete; ie, no DRC state remains
 880  * on the server we want to save.
 881  *
 882  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 883  * xs_reset_transport() zeroing the socket from underneath a writer.
 884  */
 885 static void xs_close(struct rpc_xprt *xprt)
 886 {
 887         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 888
 889         dprintk("RPC:       xs_close xprt %p\n", xprt);
 890
 891         xs_reset_transport(transport);
 892         xprt->reestablish_timeout = 0;
 893
 894         xprt_disconnect_done(xprt);
 895 }
 896
 897 static void xs_inject_disconnect(struct rpc_xprt *xprt)
 898 {
 899         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
 900                 xprt);
 901         xprt_disconnect_done(xprt);
 902 }
 903
 904 static void xs_xprt_free(struct rpc_xprt *xprt)
 905 {
 906         xs_free_peer_addresses(xprt);
 907         xprt_free(xprt);
 908 }
 909
 910 /**
 911  * xs_destroy - prepare to shutdown a transport
 912  * @xprt: doomed transport
 913  *
 914  */
 915 static void xs_destroy(struct rpc_xprt *xprt)
 916 {
 917         struct sock_xprt *transport = container_of(xprt,
 918                         struct sock_xprt, xprt);
 919         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 920
 921         cancel_delayed_work_sync(&transport->connect_worker);
 922         xs_close(xprt);
 923         cancel_work_sync(&transport->recv_worker);
 924         xs_xprt_free(xprt);
 925         module_put(THIS_MODULE);
 926 }
 927
 928 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 929 {
 930         struct xdr_skb_reader desc = {
 931                 .skb            = skb,
 932                 .offset         = sizeof(rpc_fraghdr),
 933                 .count          = skb->len - sizeof(rpc_fraghdr),
 934         };
 935
 936         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
 937                 return -1;
 938         if (desc.count)
 939                 return -1;
 940         return 0;
 941 }
 942
 943 /**
 944  * xs_local_data_read_skb
 945  * @xprt: transport
 946  * @sk: socket
 947  * @skb: skbuff
 948  *
 949  * Currently this assumes we can read the whole reply in a single gulp.
 950  */
 951 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
 952                 struct sock *sk,
 953                 struct sk_buff *skb)
 954 {
 955         struct rpc_task *task;
 956         struct rpc_rqst *rovr;
 957         int repsize, copied;
 958         u32 _xid;
 959         __be32 *xp;
 960
 961         repsize = skb->len - sizeof(rpc_fraghdr);
 962         if (repsize < 4) {
 963                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
 964                 return;
 965         }
 966
 967         /* Copy the XID from the skb... */
 968         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 969         if (xp == NULL)
 970                 return;
 971
 972         /* Look up and lock the request corresponding to the given XID */
 973         spin_lock(&xprt->recv_lock);
 974         rovr = xprt_lookup_rqst(xprt, *xp);
 975         if (!rovr)
 976                 goto out_unlock;
 977         xprt_pin_rqst(rovr);
 978         spin_unlock(&xprt->recv_lock);
 979         task = rovr->rq_task;
 980
 981         copied = rovr->rq_private_buf.buflen;
 982         if (copied > repsize)
 983                 copied = repsize;
 984
 985         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 986                 dprintk("RPC:       sk_buff copy failed\n");
 987                 spin_lock(&xprt->recv_lock);
 988                 goto out_unpin;
 989         }
 990
 991         spin_lock(&xprt->recv_lock);
 992         xprt_complete_rqst(task, copied);
 993 out_unpin:
 994         xprt_unpin_rqst(rovr);
 995  out_unlock:
 996         spin_unlock(&xprt->recv_lock);
 997 }
 998
 999 static void xs_local_data_receive(struct sock_xprt *transport)
1000 {
1001         struct sk_buff *skb;
1002         struct sock *sk;
1003         int err;
1004
1005         mutex_lock(&transport->recv_mutex);
1006         sk = transport->inet;
1007         if (sk == NULL)
1008                 goto out;
1009         for (;;) {
1010                 skb = skb_recv_datagram(sk, 0, 1, &err);
1011                 if (skb != NULL) {
1012                         xs_local_data_read_skb(&transport->xprt, sk, skb);
1013                         skb_free_datagram(sk, skb);
1014                         continue;
1015                 }
1016                 if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1017                         break;
1018         }
1019 out:
1020         mutex_unlock(&transport->recv_mutex);
1021 }
1022
1023 static void xs_local_data_receive_workfn(struct work_struct *work)
1024 {
1025         struct sock_xprt *transport =
1026                 container_of(work, struct sock_xprt, recv_worker);
1027         xs_local_data_receive(transport);
1028 }
1029
1030 /**
1031  * xs_udp_data_read_skb - receive callback for UDP sockets
1032  * @xprt: transport
1033  * @sk: socket
1034  * @skb: skbuff
1035  *
1036  */
1037 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
1038                 struct sock *sk,
1039                 struct sk_buff *skb)
1040 {
1041         struct rpc_task *task;
1042         struct rpc_rqst *rovr;
1043         int repsize, copied;
1044         u32 _xid;
1045         __be32 *xp;
1046
1047         repsize = skb->len;
1048         if (repsize < 4) {
1049                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1050                 return;
1051         }
1052
1053         /* Copy the XID from the skb... */
1054         xp = skb_header_pointer(skb, 0, sizeof(_xid), &_xid);
1055         if (xp == NULL)
1056                 return;
1057
1058         /* Look up and lock the request corresponding to the given XID */
1059         spin_lock(&xprt->recv_lock);
1060         rovr = xprt_lookup_rqst(xprt, *xp);
1061         if (!rovr)
1062                 goto out_unlock;
1063         xprt_pin_rqst(rovr);
1064         spin_unlock(&xprt->recv_lock);
1065         task = rovr->rq_task;
1066
1067         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1068                 copied = repsize;
1069
1070         /* Suck it into the iovec, verify checksum if not done by hw. */
1071         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1072                 __UDPX_INC_STATS(sk, UDP_MIB_INERRORS);
1073                 spin_lock(&xprt->recv_lock);
1074                 goto out_unpin;
1075         }
1076
1077         __UDPX_INC_STATS(sk, UDP_MIB_INDATAGRAMS);
1078
1079         spin_lock_bh(&xprt->transport_lock);
1080         xprt_adjust_cwnd(xprt, task, copied);
1081         spin_unlock_bh(&xprt->transport_lock);
1082         spin_lock(&xprt->recv_lock);
1083         xprt_complete_rqst(task, copied);
1084 out_unpin:
1085         xprt_unpin_rqst(rovr);
1086  out_unlock:
1087         spin_unlock(&xprt->recv_lock);
1088 }
1089
1090 static void xs_udp_data_receive(struct sock_xprt *transport)
1091 {
1092         struct sk_buff *skb;
1093         struct sock *sk;
1094         int err;
1095
1096         mutex_lock(&transport->recv_mutex);
1097         sk = transport->inet;
1098         if (sk == NULL)
1099                 goto out;
1100         for (;;) {
1101                 skb = skb_recv_udp(sk, 0, 1, &err);
1102                 if (skb != NULL) {
1103                         xs_udp_data_read_skb(&transport->xprt, sk, skb);
1104                         consume_skb(skb);
1105                         continue;
1106                 }
1107                 if (!test_and_clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1108                         break;
1109         }
1110 out:
1111         mutex_unlock(&transport->recv_mutex);
1112 }
1113
1114 static void xs_udp_data_receive_workfn(struct work_struct *work)
1115 {
1116         struct sock_xprt *transport =
1117                 container_of(work, struct sock_xprt, recv_worker);
1118         xs_udp_data_receive(transport);
1119 }
1120
1121 /**
1122  * xs_data_ready - "data ready" callback for UDP sockets
1123  * @sk: socket with data to read
1124  *
1125  */
1126 static void xs_data_ready(struct sock *sk)
1127 {
1128         struct rpc_xprt *xprt;
1129
1130         read_lock_bh(&sk->sk_callback_lock);
1131         dprintk("RPC:       xs_data_ready...\n");
1132         xprt = xprt_from_sock(sk);
1133         if (xprt != NULL) {
1134                 struct sock_xprt *transport = container_of(xprt,
1135                                 struct sock_xprt, xprt);
1136                 transport->old_data_ready(sk);
1137                 /* Any data means we had a useful conversation, so
1138                  * then we don't need to delay the next reconnect
1139                  */
1140                 if (xprt->reestablish_timeout)
1141                         xprt->reestablish_timeout = 0;
1142                 if (!test_and_set_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1143                         queue_work(xprtiod_workqueue, &transport->recv_worker);
1144         }
1145         read_unlock_bh(&sk->sk_callback_lock);
1146 }
1147
1148 /*
1149  * Helper function to force a TCP close if the server is sending
1150  * junk and/or it has put us in CLOSE_WAIT
1151  */
1152 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1153 {
1154         xprt_force_disconnect(xprt);
1155 }
1156
1157 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1158 {
1159         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1160         size_t len, used;
1161         char *p;
1162
1163         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1164         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1165         used = xdr_skb_read_bits(desc, p, len);
1166         transport->tcp_offset += used;
1167         if (used != len)
1168                 return;
1169
1170         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1171         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1172                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1173         else
1174                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1175         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1176
1177         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1178         transport->tcp_offset = 0;
1179
1180         /* Sanity check of the record length */
1181         if (unlikely(transport->tcp_reclen < 8)) {
1182                 dprintk("RPC:       invalid TCP record fragment length\n");
1183                 xs_tcp_force_close(xprt);
1184                 return;
1185         }
1186         dprintk("RPC:       reading TCP record fragment of length %d\n",
1187                         transport->tcp_reclen);
1188 }
1189
1190 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1191 {
1192         if (transport->tcp_offset == transport->tcp_reclen) {
1193                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1194                 transport->tcp_offset = 0;
1195                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1196                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1197                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1198                         transport->tcp_copied = 0;
1199                 }
1200         }
1201 }
1202
1203 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1204 {
1205         size_t len, used;
1206         char *p;
1207
1208         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1209         dprintk("RPC:       reading XID (%zu bytes)\n", len);
1210         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1211         used = xdr_skb_read_bits(desc, p, len);
1212         transport->tcp_offset += used;
1213         if (used != len)
1214                 return;
1215         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1216         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1217         transport->tcp_copied = 4;
1218         dprintk("RPC:       reading %s XID %08x\n",
1219                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1220                                                               : "request with",
1221                         ntohl(transport->tcp_xid));
1222         xs_tcp_check_fraghdr(transport);
1223 }
1224
1225 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1226                                        struct xdr_skb_reader *desc)
1227 {
1228         size_t len, used;
1229         u32 offset;
1230         char *p;
1231
1232         /*
1233          * We want transport->tcp_offset to be 8 at the end of this routine
1234          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1235          * When this function is called for the first time,
1236          * transport->tcp_offset is 4 (after having already read the xid).
1237          */
1238         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1239         len = sizeof(transport->tcp_calldir) - offset;
1240         dprintk("RPC:       reading CALL/REPLY flag (%zu bytes)\n", len);
1241         p = ((char *) &transport->tcp_calldir) + offset;
1242         used = xdr_skb_read_bits(desc, p, len);
1243         transport->tcp_offset += used;
1244         if (used != len)
1245                 return;
1246         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1247         /*
1248          * We don't yet have the XDR buffer, so we will write the calldir
1249          * out after we get the buffer from the 'struct rpc_rqst'
1250          */
1251         switch (ntohl(transport->tcp_calldir)) {
1252         case RPC_REPLY:
1253                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1254                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1255                 transport->tcp_flags |= TCP_RPC_REPLY;
1256                 break;
1257         case RPC_CALL:
1258                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1259                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1260                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1261                 break;
1262         default:
1263                 dprintk("RPC:       invalid request message type\n");
1264                 xs_tcp_force_close(&transport->xprt);
1265         }
1266         xs_tcp_check_fraghdr(transport);
1267 }
1268
1269 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1270                                      struct xdr_skb_reader *desc,
1271                                      struct rpc_rqst *req)
1272 {
1273         struct sock_xprt *transport =
1274                                 container_of(xprt, struct sock_xprt, xprt);
1275         struct xdr_buf *rcvbuf;
1276         size_t len;
1277         ssize_t r;
1278
1279         rcvbuf = &req->rq_private_buf;
1280
1281         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1282                 /*
1283                  * Save the RPC direction in the XDR buffer
1284                  */
1285                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1286                         &transport->tcp_calldir,
1287                         sizeof(transport->tcp_calldir));
1288                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1289                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1290         }
1291
1292         len = desc->count;
1293         if (len > transport->tcp_reclen - transport->tcp_offset)
1294                 desc->count = transport->tcp_reclen - transport->tcp_offset;
1295         r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1296                                           desc, xdr_skb_read_bits);
1297
1298         if (desc->count) {
1299                 /* Error when copying to the receive buffer,
1300                  * usually because we weren't able to allocate
1301                  * additional buffer pages. All we can do now
1302                  * is turn off TCP_RCV_COPY_DATA, so the request
1303                  * will not receive any additional updates,
1304                  * and time out.
1305                  * Any remaining data from this record will
1306                  * be discarded.
1307                  */
1308                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1309                 dprintk("RPC:       XID %08x truncated request\n",
1310                                 ntohl(transport->tcp_xid));
1311                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1312                                 "tcp_offset = %u, tcp_reclen = %u\n",
1313                                 xprt, transport->tcp_copied,
1314                                 transport->tcp_offset, transport->tcp_reclen);
1315                 return;
1316         }
1317
1318         transport->tcp_copied += r;
1319         transport->tcp_offset += r;
1320         desc->count = len - r;
1321
1322         dprintk("RPC:       XID %08x read %zd bytes\n",
1323                         ntohl(transport->tcp_xid), r);
1324         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1325                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1326                         transport->tcp_offset, transport->tcp_reclen);
1327
1328         if (transport->tcp_copied == req->rq_private_buf.buflen)
1329                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1330         else if (transport->tcp_offset == transport->tcp_reclen) {
1331                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1332                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1333         }
1334 }
1335
1336 /*
1337  * Finds the request corresponding to the RPC xid and invokes the common
1338  * tcp read code to read the data.
1339  */
1340 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1341                                     struct xdr_skb_reader *desc)
1342 {
1343         struct sock_xprt *transport =
1344                                 container_of(xprt, struct sock_xprt, xprt);
1345         struct rpc_rqst *req;
1346
1347         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1348
1349         /* Find and lock the request corresponding to this xid */
1350         spin_lock(&xprt->recv_lock);
1351         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1352         if (!req) {
1353                 dprintk("RPC:       XID %08x request not found!\n",
1354                                 ntohl(transport->tcp_xid));
1355                 spin_unlock(&xprt->recv_lock);
1356                 return -1;
1357         }
1358         xprt_pin_rqst(req);
1359         spin_unlock(&xprt->recv_lock);
1360
1361         xs_tcp_read_common(xprt, desc, req);
1362
1363         spin_lock(&xprt->recv_lock);
1364         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1365                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1366         xprt_unpin_rqst(req);
1367         spin_unlock(&xprt->recv_lock);
1368         return 0;
1369 }
1370
1371 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1372 /*
1373  * Obtains an rpc_rqst previously allocated and invokes the common
1374  * tcp read code to read the data.  The result is placed in the callback
1375  * queue.
1376  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1377  * connection and return -1.
1378  */
1379 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1380                                        struct xdr_skb_reader *desc)
1381 {
1382         struct sock_xprt *transport =
1383                                 container_of(xprt, struct sock_xprt, xprt);
1384         struct rpc_rqst *req;
1385
1386         /* Look up the request corresponding to the given XID */
1387         req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1388         if (req == NULL) {
1389                 printk(KERN_WARNING "Callback slot table overflowed\n");
1390                 xprt_force_disconnect(xprt);
1391                 return -1;
1392         }
1393
1394         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1395         xs_tcp_read_common(xprt, desc, req);
1396
1397         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1398                 xprt_complete_bc_request(req, transport->tcp_copied);
1399
1400         return 0;
1401 }
1402
1403 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1404                                         struct xdr_skb_reader *desc)
1405 {
1406         struct sock_xprt *transport =
1407                                 container_of(xprt, struct sock_xprt, xprt);
1408
1409         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1410                 xs_tcp_read_reply(xprt, desc) :
1411                 xs_tcp_read_callback(xprt, desc);
1412 }
1413
1414 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1415 {
1416         int ret;
1417
1418         ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1419                               SVC_SOCK_ANONYMOUS);
1420         if (ret < 0)
1421                 return ret;
1422         return 0;
1423 }
1424
1425 static size_t xs_tcp_bc_maxpayload(struct rpc_xprt *xprt)
1426 {
1427         return PAGE_SIZE;
1428 }
1429 #else
1430 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1431                                         struct xdr_skb_reader *desc)
1432 {
1433         return xs_tcp_read_reply(xprt, desc);
1434 }
1435 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1436
1437 /*
1438  * Read data off the transport.  This can be either an RPC_CALL or an
1439  * RPC_REPLY.  Relay the processing to helper functions.
1440  */
1441 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1442                                     struct xdr_skb_reader *desc)
1443 {
1444         struct sock_xprt *transport =
1445                                 container_of(xprt, struct sock_xprt, xprt);
1446
1447         if (_xs_tcp_read_data(xprt, desc) == 0)
1448                 xs_tcp_check_fraghdr(transport);
1449         else {
1450                 /*
1451                  * The transport_lock protects the request handling.
1452                  * There's no need to hold it to update the tcp_flags.
1453                  */
1454                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1455         }
1456 }
1457
1458 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1459 {
1460         size_t len;
1461
1462         len = transport->tcp_reclen - transport->tcp_offset;
1463         if (len > desc->count)
1464                 len = desc->count;
1465         desc->count -= len;
1466         desc->offset += len;
1467         transport->tcp_offset += len;
1468         dprintk("RPC:       discarded %zu bytes\n", len);
1469         xs_tcp_check_fraghdr(transport);
1470 }
1471
1472 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1473 {
1474         struct rpc_xprt *xprt = rd_desc->arg.data;
1475         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1476         struct xdr_skb_reader desc = {
1477                 .skb    = skb,
1478                 .offset = offset,
1479                 .count  = len,
1480         };
1481
1482         dprintk("RPC:       xs_tcp_data_recv started\n");
1483         do {
1484                 trace_xs_tcp_data_recv(transport);
1485                 /* Read in a new fragment marker if necessary */
1486                 /* Can we ever really expect to get completely empty fragments? */
1487                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1488                         xs_tcp_read_fraghdr(xprt, &desc);
1489                         continue;
1490                 }
1491                 /* Read in the xid if necessary */
1492                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1493                         xs_tcp_read_xid(transport, &desc);
1494                         continue;
1495                 }
1496                 /* Read in the call/reply flag */
1497                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1498                         xs_tcp_read_calldir(transport, &desc);
1499                         continue;
1500                 }
1501                 /* Read in the request data */
1502                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1503                         xs_tcp_read_data(xprt, &desc);
1504                         continue;
1505                 }
1506                 /* Skip over any trailing bytes on short reads */
1507                 xs_tcp_read_discard(transport, &desc);
1508         } while (desc.count);
1509         trace_xs_tcp_data_recv(transport);
1510         dprintk("RPC:       xs_tcp_data_recv done\n");
1511         return len - desc.count;
1512 }
1513
1514 static void xs_tcp_data_receive(struct sock_xprt *transport)
1515 {
1516         struct rpc_xprt *xprt = &transport->xprt;
1517         struct sock *sk;
1518         read_descriptor_t rd_desc = {
1519                 .count = 2*1024*1024,
1520                 .arg.data = xprt,
1521         };
1522         unsigned long total = 0;
1523         int loop;
1524         int read = 0;
1525
1526         mutex_lock(&transport->recv_mutex);
1527         sk = transport->inet;
1528         if (sk == NULL)
1529                 goto out;
1530
1531         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1532         for (loop = 0; loop < 64; loop++) {
1533                 lock_sock(sk);
1534                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1535                 if (read <= 0) {
1536                         clear_bit(XPRT_SOCK_DATA_READY, &transport->sock_state);
1537                         release_sock(sk);
1538                         break;
1539                 }
1540                 release_sock(sk);
1541                 total += read;
1542                 rd_desc.count = 65536;
1543         }
1544         if (test_bit(XPRT_SOCK_DATA_READY, &transport->sock_state))
1545                 queue_work(xprtiod_workqueue, &transport->recv_worker);
1546 out:
1547         mutex_unlock(&transport->recv_mutex);
1548         trace_xs_tcp_data_ready(xprt, read, total);
1549 }
1550
1551 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1552 {
1553         struct sock_xprt *transport =
1554                 container_of(work, struct sock_xprt, recv_worker);
1555         xs_tcp_data_receive(transport);
1556 }
1557
1558 /**
1559  * xs_tcp_state_change - callback to handle TCP socket state changes
1560  * @sk: socket whose state has changed
1561  *
1562  */
1563 static void xs_tcp_state_change(struct sock *sk)
1564 {
1565         struct rpc_xprt *xprt;
1566         struct sock_xprt *transport;
1567
1568         read_lock_bh(&sk->sk_callback_lock);
1569         if (!(xprt = xprt_from_sock(sk)))
1570                 goto out;
1571         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1572         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1573                         sk->sk_state, xprt_connected(xprt),
1574                         sock_flag(sk, SOCK_DEAD),
1575                         sock_flag(sk, SOCK_ZAPPED),
1576                         sk->sk_shutdown);
1577
1578         transport = container_of(xprt, struct sock_xprt, xprt);
1579         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1580         switch (sk->sk_state) {
1581         case TCP_ESTABLISHED:
1582                 spin_lock(&xprt->transport_lock);
1583                 if (!xprt_test_and_set_connected(xprt)) {
1584
1585                         /* Reset TCP record info */
1586                         transport->tcp_offset = 0;
1587                         transport->tcp_reclen = 0;
1588                         transport->tcp_copied = 0;
1589                         transport->tcp_flags =
1590                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1591                         xprt->connect_cookie++;
1592                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1593                         xprt_clear_connecting(xprt);
1594
1595                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1596                 }
1597                 spin_unlock(&xprt->transport_lock);
1598                 break;
1599         case TCP_FIN_WAIT1:
1600                 /* The client initiated a shutdown of the socket */
1601                 xprt->connect_cookie++;
1602                 xprt->reestablish_timeout = 0;
1603                 set_bit(XPRT_CLOSING, &xprt->state);
1604                 smp_mb__before_atomic();
1605                 clear_bit(XPRT_CONNECTED, &xprt->state);
1606                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1607                 smp_mb__after_atomic();
1608                 break;
1609         case TCP_CLOSE_WAIT:
1610                 /* The server initiated a shutdown of the socket */
1611                 xprt->connect_cookie++;
1612                 clear_bit(XPRT_CONNECTED, &xprt->state);
1613                 xs_tcp_force_close(xprt);
1614         case TCP_CLOSING:
1615                 /*
1616                  * If the server closed down the connection, make sure that
1617                  * we back off before reconnecting
1618                  */
1619                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1620                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1621                 break;
1622         case TCP_LAST_ACK:
1623                 set_bit(XPRT_CLOSING, &xprt->state);
1624                 smp_mb__before_atomic();
1625                 clear_bit(XPRT_CONNECTED, &xprt->state);
1626                 smp_mb__after_atomic();
1627                 break;
1628         case TCP_CLOSE:
1629                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1630                                         &transport->sock_state))
1631                         xprt_clear_connecting(xprt);
1632                 if (sk->sk_err)
1633                         xprt_wake_pending_tasks(xprt, -sk->sk_err);
1634                 xs_sock_mark_closed(xprt);
1635         }
1636  out:
1637         read_unlock_bh(&sk->sk_callback_lock);
1638 }
1639
1640 static void xs_write_space(struct sock *sk)
1641 {
1642         struct socket_wq *wq;
1643         struct rpc_xprt *xprt;
1644
1645         if (!sk->sk_socket)
1646                 return;
1647         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1648
1649         if (unlikely(!(xprt = xprt_from_sock(sk))))
1650                 return;
1651         rcu_read_lock();
1652         wq = rcu_dereference(sk->sk_wq);
1653         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1654                 goto out;
1655
1656         xprt_write_space(xprt);
1657 out:
1658         rcu_read_unlock();
1659 }
1660
1661 /**
1662  * xs_udp_write_space - callback invoked when socket buffer space
1663  *                             becomes available
1664  * @sk: socket whose state has changed
1665  *
1666  * Called when more output buffer space is available for this socket.
1667  * We try not to wake our writers until they can make "significant"
1668  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1669  * with a bunch of small requests.
1670  */
1671 static void xs_udp_write_space(struct sock *sk)
1672 {
1673         read_lock_bh(&sk->sk_callback_lock);
1674
1675         /* from net/core/sock.c:sock_def_write_space */
1676         if (sock_writeable(sk))
1677                 xs_write_space(sk);
1678
1679         read_unlock_bh(&sk->sk_callback_lock);
1680 }
1681
1682 /**
1683  * xs_tcp_write_space - callback invoked when socket buffer space
1684  *                             becomes available
1685  * @sk: socket whose state has changed
1686  *
1687  * Called when more output buffer space is available for this socket.
1688  * We try not to wake our writers until they can make "significant"
1689  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1690  * with a bunch of small requests.
1691  */
1692 static void xs_tcp_write_space(struct sock *sk)
1693 {
1694         read_lock_bh(&sk->sk_callback_lock);
1695
1696         /* from net/core/stream.c:sk_stream_write_space */
1697         if (sk_stream_is_writeable(sk))
1698                 xs_write_space(sk);
1699
1700         read_unlock_bh(&sk->sk_callback_lock);
1701 }
1702
1703 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1704 {
1705         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1706         struct sock *sk = transport->inet;
1707
1708         if (transport->rcvsize) {
1709                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1710                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1711         }
1712         if (transport->sndsize) {
1713                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1714                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1715                 sk->sk_write_space(sk);
1716         }
1717 }
1718
1719 /**
1720  * xs_udp_set_buffer_size - set send and receive limits
1721  * @xprt: generic transport
1722  * @sndsize: requested size of send buffer, in bytes
1723  * @rcvsize: requested size of receive buffer, in bytes
1724  *
1725  * Set socket send and receive buffer size limits.
1726  */
1727 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1728 {
1729         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1730
1731         transport->sndsize = 0;
1732         if (sndsize)
1733                 transport->sndsize = sndsize + 1024;
1734         transport->rcvsize = 0;
1735         if (rcvsize)
1736                 transport->rcvsize = rcvsize + 1024;
1737
1738         xs_udp_do_set_buffer_size(xprt);
1739 }
1740
1741 /**
1742  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1743  * @task: task that timed out
1744  *
1745  * Adjust the congestion window after a retransmit timeout has occurred.
1746  */
1747 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1748 {
1749         spin_lock_bh(&xprt->transport_lock);
1750         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1751         spin_unlock_bh(&xprt->transport_lock);
1752 }
1753
1754 static unsigned short xs_get_random_port(void)
1755 {
1756         unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
1757         unsigned short rand = (unsigned short) prandom_u32() % range;
1758         return rand + xprt_min_resvport;
1759 }
1760
1761 /**
1762  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1763  * @sock: socket
1764  *
1765  * Note that this function has to be called on all sockets that share the
1766  * same port, and it must be called before binding.
1767  */
1768 static void xs_sock_set_reuseport(struct socket *sock)
1769 {
1770         int opt = 1;
1771
1772         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1773                         (char *)&opt, sizeof(opt));
1774 }
1775
1776 static unsigned short xs_sock_getport(struct socket *sock)
1777 {
1778         struct sockaddr_storage buf;
1779         int buflen;
1780         unsigned short port = 0;
1781
1782         if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1783                 goto out;
1784         switch (buf.ss_family) {
1785         case AF_INET6:
1786                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1787                 break;
1788         case AF_INET:
1789                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1790         }
1791 out:
1792         return port;
1793 }
1794
1795 /**
1796  * xs_set_port - reset the port number in the remote endpoint address
1797  * @xprt: generic transport
1798  * @port: new port number
1799  *
1800  */
1801 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1802 {
1803         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1804
1805         rpc_set_port(xs_addr(xprt), port);
1806         xs_update_peer_port(xprt);
1807 }
1808
1809 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1810 {
1811         if (transport->srcport == 0)
1812                 transport->srcport = xs_sock_getport(sock);
1813 }
1814
1815 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1816 {
1817         unsigned short port = transport->srcport;
1818
1819         if (port == 0 && transport->xprt.resvport)
1820                 port = xs_get_random_port();
1821         return port;
1822 }
1823
1824 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1825 {
1826         if (transport->srcport != 0)
1827                 transport->srcport = 0;
1828         if (!transport->xprt.resvport)
1829                 return 0;
1830         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1831                 return xprt_max_resvport;
1832         return --port;
1833 }
1834 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1835 {
1836         struct sockaddr_storage myaddr;
1837         int err, nloop = 0;
1838         unsigned short port = xs_get_srcport(transport);
1839         unsigned short last;
1840
1841         /*
1842          * If we are asking for any ephemeral port (i.e. port == 0 &&
1843          * transport->xprt.resvport == 0), don't bind.  Let the local
1844          * port selection happen implicitly when the socket is used
1845          * (for example at connect time).
1846          *
1847          * This ensures that we can continue to establish TCP
1848          * connections even when all local ephemeral ports are already
1849          * a part of some TCP connection.  This makes no difference
1850          * for UDP sockets, but also doens't harm them.
1851          *
1852          * If we're asking for any reserved port (i.e. port == 0 &&
1853          * transport->xprt.resvport == 1) xs_get_srcport above will
1854          * ensure that port is non-zero and we will bind as needed.
1855          */
1856         if (port == 0)
1857                 return 0;
1858
1859         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1860         do {
1861                 rpc_set_port((struct sockaddr *)&myaddr, port);
1862                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1863                                 transport->xprt.addrlen);
1864                 if (err == 0) {
1865                         transport->srcport = port;
1866                         break;
1867                 }
1868                 last = port;
1869                 port = xs_next_srcport(transport, port);
1870                 if (port > last)
1871                         nloop++;
1872         } while (err == -EADDRINUSE && nloop != 2);
1873
1874         if (myaddr.ss_family == AF_INET)
1875                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1876                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1877                                 port, err ? "failed" : "ok", err);
1878         else
1879                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1880                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1881                                 port, err ? "failed" : "ok", err);
1882         return err;
1883 }
1884
1885 /*
1886  * We don't support autobind on AF_LOCAL sockets
1887  */
1888 static void xs_local_rpcbind(struct rpc_task *task)
1889 {
1890         xprt_set_bound(task->tk_xprt);
1891 }
1892
1893 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1894 {
1895 }
1896
1897 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1898 static struct lock_class_key xs_key[2];
1899 static struct lock_class_key xs_slock_key[2];
1900
1901 static inline void xs_reclassify_socketu(struct socket *sock)
1902 {
1903         struct sock *sk = sock->sk;
1904
1905         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1906                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1907 }
1908
1909 static inline void xs_reclassify_socket4(struct socket *sock)
1910 {
1911         struct sock *sk = sock->sk;
1912
1913         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1914                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1915 }
1916
1917 static inline void xs_reclassify_socket6(struct socket *sock)
1918 {
1919         struct sock *sk = sock->sk;
1920
1921         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1922                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1923 }
1924
1925 static inline void xs_reclassify_socket(int family, struct socket *sock)
1926 {
1927         if (WARN_ON_ONCE(!sock_allow_reclassification(sock->sk)))
1928                 return;
1929
1930         switch (family) {
1931         case AF_LOCAL:
1932                 xs_reclassify_socketu(sock);
1933                 break;
1934         case AF_INET:
1935                 xs_reclassify_socket4(sock);
1936                 break;
1937         case AF_INET6:
1938                 xs_reclassify_socket6(sock);
1939                 break;
1940         }
1941 }
1942 #else
1943 static inline void xs_reclassify_socket(int family, struct socket *sock)
1944 {
1945 }
1946 #endif
1947
1948 static void xs_dummy_setup_socket(struct work_struct *work)
1949 {
1950 }
1951
1952 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1953                 struct sock_xprt *transport, int family, int type,
1954                 int protocol, bool reuseport)
1955 {
1956         struct socket *sock;
1957         int err;
1958
1959         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1960         if (err < 0) {
1961                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1962                                 protocol, -err);
1963                 goto out;
1964         }
1965         xs_reclassify_socket(family, sock);
1966
1967         if (reuseport)
1968                 xs_sock_set_reuseport(sock);
1969
1970         err = xs_bind(transport, sock);
1971         if (err) {
1972                 sock_release(sock);
1973                 goto out;
1974         }
1975
1976         return sock;
1977 out:
1978         return ERR_PTR(err);
1979 }
1980
1981 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1982                                       struct socket *sock)
1983 {
1984         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1985                                                                         xprt);
1986
1987         if (!transport->inet) {
1988                 struct sock *sk = sock->sk;
1989
1990                 write_lock_bh(&sk->sk_callback_lock);
1991
1992                 xs_save_old_callbacks(transport, sk);
1993
1994                 sk->sk_user_data = xprt;
1995                 sk->sk_data_ready = xs_data_ready;
1996                 sk->sk_write_space = xs_udp_write_space;
1997                 sock_set_flag(sk, SOCK_FASYNC);
1998                 sk->sk_error_report = xs_error_report;
1999                 sk->sk_allocation = GFP_NOIO;
2000
2001                 xprt_clear_connected(xprt);
2002
2003                 /* Reset to new socket */
2004                 transport->sock = sock;
2005                 transport->inet = sk;
2006
2007                 write_unlock_bh(&sk->sk_callback_lock);
2008         }
2009
2010         /* Tell the socket layer to start connecting... */
2011         xprt->stat.connect_count++;
2012         xprt->stat.connect_start = jiffies;
2013         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
2014 }
2015
2016 /**
2017  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
2018  * @transport: socket transport to connect
2019  */
2020 static int xs_local_setup_socket(struct sock_xprt *transport)
2021 {
2022         struct rpc_xprt *xprt = &transport->xprt;
2023         struct socket *sock;
2024         int status = -EIO;
2025
2026         status = __sock_create(xprt->xprt_net, AF_LOCAL,
2027                                         SOCK_STREAM, 0, &sock, 1);
2028         if (status < 0) {
2029                 dprintk("RPC:       can't create AF_LOCAL "
2030                         "transport socket (%d).\n", -status);
2031                 goto out;
2032         }
2033         xs_reclassify_socket(AF_LOCAL, sock);
2034
2035         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
2036                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2037
2038         status = xs_local_finish_connecting(xprt, sock);
2039         trace_rpc_socket_connect(xprt, sock, status);
2040         switch (status) {
2041         case 0:
2042                 dprintk("RPC:       xprt %p connected to %s\n",
2043                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2044                 xprt_set_connected(xprt);
2045         case -ENOBUFS:
2046                 break;
2047         case -ENOENT:
2048                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
2049                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2050                 break;
2051         case -ECONNREFUSED:
2052                 dprintk("RPC:       xprt %p: connection refused for %s\n",
2053                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2054                 break;
2055         default:
2056                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2057                                 __func__, -status,
2058                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
2059         }
2060
2061 out:
2062         xprt_clear_connecting(xprt);
2063         xprt_wake_pending_tasks(xprt, status);
2064         return status;
2065 }
2066
2067 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2068 {
2069         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2070         int ret;
2071
2072          if (RPC_IS_ASYNC(task)) {
2073                 /*
2074                  * We want the AF_LOCAL connect to be resolved in the
2075                  * filesystem namespace of the process making the rpc
2076                  * call.  Thus we connect synchronously.
2077                  *
2078                  * If we want to support asynchronous AF_LOCAL calls,
2079                  * we'll need to figure out how to pass a namespace to
2080                  * connect.
2081                  */
2082                 rpc_exit(task, -ENOTCONN);
2083                 return;
2084         }
2085         ret = xs_local_setup_socket(transport);
2086         if (ret && !RPC_IS_SOFTCONN(task))
2087                 msleep_interruptible(15000);
2088 }
2089
2090 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2091 /*
2092  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2093  * know that we have exclusive access to the socket), to guard against
2094  * races with xs_reset_transport.
2095  */
2096 static void xs_set_memalloc(struct rpc_xprt *xprt)
2097 {
2098         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2099                         xprt);
2100
2101         /*
2102          * If there's no sock, then we have nothing to set. The
2103          * reconnecting process will get it for us.
2104          */
2105         if (!transport->inet)
2106                 return;
2107         if (atomic_read(&xprt->swapper))
2108                 sk_set_memalloc(transport->inet);
2109 }
2110
2111 /**
2112  * xs_enable_swap - Tag this transport as being used for swap.
2113  * @xprt: transport to tag
2114  *
2115  * Take a reference to this transport on behalf of the rpc_clnt, and
2116  * optionally mark it for swapping if it wasn't already.
2117  */
2118 static int
2119 xs_enable_swap(struct rpc_xprt *xprt)
2120 {
2121         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2122
2123         if (atomic_inc_return(&xprt->swapper) != 1)
2124                 return 0;
2125         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2126                 return -ERESTARTSYS;
2127         if (xs->inet)
2128                 sk_set_memalloc(xs->inet);
2129         xprt_release_xprt(xprt, NULL);
2130         return 0;
2131 }
2132
2133 /**
2134  * xs_disable_swap - Untag this transport as being used for swap.
2135  * @xprt: transport to tag
2136  *
2137  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2138  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2139  */
2140 static void
2141 xs_disable_swap(struct rpc_xprt *xprt)
2142 {
2143         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2144
2145         if (!atomic_dec_and_test(&xprt->swapper))
2146                 return;
2147         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2148                 return;
2149         if (xs->inet)
2150                 sk_clear_memalloc(xs->inet);
2151         xprt_release_xprt(xprt, NULL);
2152 }
2153 #else
2154 static void xs_set_memalloc(struct rpc_xprt *xprt)
2155 {
2156 }
2157
2158 static int
2159 xs_enable_swap(struct rpc_xprt *xprt)
2160 {
2161         return -EINVAL;
2162 }
2163
2164 static void
2165 xs_disable_swap(struct rpc_xprt *xprt)
2166 {
2167 }
2168 #endif
2169
2170 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2171 {
2172         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2173
2174         if (!transport->inet) {
2175                 struct sock *sk = sock->sk;
2176
2177                 write_lock_bh(&sk->sk_callback_lock);
2178
2179                 xs_save_old_callbacks(transport, sk);
2180
2181                 sk->sk_user_data = xprt;
2182                 sk->sk_data_ready = xs_data_ready;
2183                 sk->sk_write_space = xs_udp_write_space;
2184                 sock_set_flag(sk, SOCK_FASYNC);
2185                 sk->sk_allocation = GFP_NOIO;
2186
2187                 xprt_set_connected(xprt);
2188
2189                 /* Reset to new socket */
2190                 transport->sock = sock;
2191                 transport->inet = sk;
2192
2193                 xs_set_memalloc(xprt);
2194
2195                 write_unlock_bh(&sk->sk_callback_lock);
2196         }
2197         xs_udp_do_set_buffer_size(xprt);
2198
2199         xprt->stat.connect_start = jiffies;
2200 }
2201
2202 static void xs_udp_setup_socket(struct work_struct *work)
2203 {
2204         struct sock_xprt *transport =
2205                 container_of(work, struct sock_xprt, connect_worker.work);
2206         struct rpc_xprt *xprt = &transport->xprt;
2207         struct socket *sock;
2208         int status = -EIO;
2209
2210         sock = xs_create_sock(xprt, transport,
2211                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2212                         IPPROTO_UDP, false);
2213         if (IS_ERR(sock))
2214                 goto out;
2215
2216         dprintk("RPC:       worker connecting xprt %p via %s to "
2217                                 "%s (port %s)\n", xprt,
2218                         xprt->address_strings[RPC_DISPLAY_PROTO],
2219                         xprt->address_strings[RPC_DISPLAY_ADDR],
2220                         xprt->address_strings[RPC_DISPLAY_PORT]);
2221
2222         xs_udp_finish_connecting(xprt, sock);
2223         trace_rpc_socket_connect(xprt, sock, 0);
2224         status = 0;
2225 out:
2226         xprt_unlock_connect(xprt, transport);
2227         xprt_clear_connecting(xprt);
2228         xprt_wake_pending_tasks(xprt, status);
2229 }
2230
2231 /**
2232  * xs_tcp_shutdown - gracefully shut down a TCP socket
2233  * @xprt: transport
2234  *
2235  * Initiates a graceful shutdown of the TCP socket by calling the
2236  * equivalent of shutdown(SHUT_RDWR);
2237  */
2238 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2239 {
2240         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2241         struct socket *sock = transport->sock;
2242
2243         if (sock == NULL)
2244                 return;
2245         if (xprt_connected(xprt)) {
2246                 kernel_sock_shutdown(sock, SHUT_RDWR);
2247                 trace_rpc_socket_shutdown(xprt, sock);
2248         } else
2249                 xs_reset_transport(transport);
2250 }
2251
2252 static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
2253                 struct socket *sock)
2254 {
2255         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2256         unsigned int keepidle;
2257         unsigned int keepcnt;
2258         unsigned int opt_on = 1;
2259         unsigned int timeo;
2260
2261         spin_lock_bh(&xprt->transport_lock);
2262         keepidle = DIV_ROUND_UP(xprt->timeout->to_initval, HZ);
2263         keepcnt = xprt->timeout->to_retries + 1;
2264         timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2265                 (xprt->timeout->to_retries + 1);
2266         clear_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2267         spin_unlock_bh(&xprt->transport_lock);
2268
2269         /* TCP Keepalive options */
2270         kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2271                         (char *)&opt_on, sizeof(opt_on));
2272         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2273                         (char *)&keepidle, sizeof(keepidle));
2274         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2275                         (char *)&keepidle, sizeof(keepidle));
2276         kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2277                         (char *)&keepcnt, sizeof(keepcnt));
2278
2279         /* TCP user timeout (see RFC5482) */
2280         kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2281                         (char *)&timeo, sizeof(timeo));
2282 }
2283
2284 static void xs_tcp_set_connect_timeout(struct rpc_xprt *xprt,
2285                 unsigned long connect_timeout,
2286                 unsigned long reconnect_timeout)
2287 {
2288         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2289         struct rpc_timeout to;
2290         unsigned long initval;
2291
2292         spin_lock_bh(&xprt->transport_lock);
2293         if (reconnect_timeout < xprt->max_reconnect_timeout)
2294                 xprt->max_reconnect_timeout = reconnect_timeout;
2295         if (connect_timeout < xprt->connect_timeout) {
2296                 memcpy(&to, xprt->timeout, sizeof(to));
2297                 initval = DIV_ROUND_UP(connect_timeout, to.to_retries + 1);
2298                 /* Arbitrary lower limit */
2299                 if (initval <  XS_TCP_INIT_REEST_TO << 1)
2300                         initval = XS_TCP_INIT_REEST_TO << 1;
2301                 to.to_initval = initval;
2302                 to.to_maxval = initval;
2303                 memcpy(&transport->tcp_timeout, &to,
2304                                 sizeof(transport->tcp_timeout));
2305                 xprt->timeout = &transport->tcp_timeout;
2306                 xprt->connect_timeout = connect_timeout;
2307         }
2308         set_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state);
2309         spin_unlock_bh(&xprt->transport_lock);
2310 }
2311
2312 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2313 {
2314         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2315         int ret = -ENOTCONN;
2316
2317         if (!transport->inet) {
2318                 struct sock *sk = sock->sk;
2319                 unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;
2320
2321                 /* Avoid temporary address, they are bad for long-lived
2322                  * connections such as NFS mounts.
2323                  * RFC4941, section 3.6 suggests that:
2324                  *    Individual applications, which have specific
2325                  *    knowledge about the normal duration of connections,
2326                  *    MAY override this as appropriate.
2327                  */
2328                 kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
2329                                 (char *)&addr_pref, sizeof(addr_pref));
2330
2331                 xs_tcp_set_socket_timeouts(xprt, sock);
2332
2333                 write_lock_bh(&sk->sk_callback_lock);
2334
2335                 xs_save_old_callbacks(transport, sk);
2336
2337                 sk->sk_user_data = xprt;
2338                 sk->sk_data_ready = xs_data_ready;
2339                 sk->sk_state_change = xs_tcp_state_change;
2340                 sk->sk_write_space = xs_tcp_write_space;
2341                 sock_set_flag(sk, SOCK_FASYNC);
2342                 sk->sk_error_report = xs_error_report;
2343                 sk->sk_allocation = GFP_NOIO;
2344
2345                 /* socket options */
2346                 sock_reset_flag(sk, SOCK_LINGER);
2347                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2348
2349                 xprt_clear_connected(xprt);
2350
2351                 /* Reset to new socket */
2352                 transport->sock = sock;
2353                 transport->inet = sk;
2354
2355                 write_unlock_bh(&sk->sk_callback_lock);
2356         }
2357
2358         if (!xprt_bound(xprt))
2359                 goto out;
2360
2361         xs_set_memalloc(xprt);
2362
2363         /* Tell the socket layer to start connecting... */
2364         xprt->stat.connect_count++;
2365         xprt->stat.connect_start = jiffies;
2366         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2367         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2368         switch (ret) {
2369         case 0:
2370                 xs_set_srcport(transport, sock);
2371         case -EINPROGRESS:
2372                 /* SYN_SENT! */
2373                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2374                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2375                 break;
2376         case -EADDRNOTAVAIL:
2377                 /* Source port number is unavailable. Try a new one! */
2378                 transport->srcport = 0;
2379         }
2380 out:
2381         return ret;
2382 }
2383
2384 /**
2385  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2386  *
2387  * Invoked by a work queue tasklet.
2388  */
2389 static void xs_tcp_setup_socket(struct work_struct *work)
2390 {
2391         struct sock_xprt *transport =
2392                 container_of(work, struct sock_xprt, connect_worker.work);
2393         struct socket *sock = transport->sock;
2394         struct rpc_xprt *xprt = &transport->xprt;
2395         int status = -EIO;
2396
2397         if (!sock) {
2398                 sock = xs_create_sock(xprt, transport,
2399                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2400                                 IPPROTO_TCP, true);
2401                 if (IS_ERR(sock)) {
2402                         status = PTR_ERR(sock);
2403                         goto out;
2404                 }
2405         }
2406
2407         dprintk("RPC:       worker connecting xprt %p via %s to "
2408                                 "%s (port %s)\n", xprt,
2409                         xprt->address_strings[RPC_DISPLAY_PROTO],
2410                         xprt->address_strings[RPC_DISPLAY_ADDR],
2411                         xprt->address_strings[RPC_DISPLAY_PORT]);
2412
2413         status = xs_tcp_finish_connecting(xprt, sock);
2414         trace_rpc_socket_connect(xprt, sock, status);
2415         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2416                         xprt, -status, xprt_connected(xprt),
2417                         sock->sk->sk_state);
2418         switch (status) {
2419         default:
2420                 printk("%s: connect returned unhandled error %d\n",
2421                         __func__, status);
2422         case -EADDRNOTAVAIL:
2423                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2424                  * and retry
2425                  */
2426                 xs_tcp_force_close(xprt);
2427                 break;
2428         case 0:
2429         case -EINPROGRESS:
2430         case -EALREADY:
2431                 xprt_unlock_connect(xprt, transport);
2432                 return;
2433         case -EINVAL:
2434                 /* Happens, for instance, if the user specified a link
2435                  * local IPv6 address without a scope-id.
2436                  */
2437         case -ECONNREFUSED:
2438         case -ECONNRESET:
2439         case -ENETUNREACH:
2440         case -EADDRINUSE:
2441         case -ENOBUFS:
2442                 /*
2443                  * xs_tcp_force_close() wakes tasks with -EIO.
2444                  * We need to wake them first to ensure the
2445                  * correct error code.
2446                  */
2447                 xprt_wake_pending_tasks(xprt, status);
2448                 xs_tcp_force_close(xprt);
2449                 goto out;
2450         }
2451         status = -EAGAIN;
2452 out:
2453         xprt_unlock_connect(xprt, transport);
2454         xprt_clear_connecting(xprt);
2455         xprt_wake_pending_tasks(xprt, status);
2456 }
2457
2458 static unsigned long xs_reconnect_delay(const struct rpc_xprt *xprt)
2459 {
2460         unsigned long start, now = jiffies;
2461
2462         start = xprt->stat.connect_start + xprt->reestablish_timeout;
2463         if (time_after(start, now))
2464                 return start - now;
2465         return 0;
2466 }
2467
2468 static void xs_reconnect_backoff(struct rpc_xprt *xprt)
2469 {
2470         xprt->reestablish_timeout <<= 1;
2471         if (xprt->reestablish_timeout > xprt->max_reconnect_timeout)
2472                 xprt->reestablish_timeout = xprt->max_reconnect_timeout;
2473         if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2474                 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2475 }
2476
2477 /**
2478  * xs_connect - connect a socket to a remote endpoint
2479  * @xprt: pointer to transport structure
2480  * @task: address of RPC task that manages state of connect request
2481  *
2482  * TCP: If the remote end dropped the connection, delay reconnecting.
2483  *
2484  * UDP socket connects are synchronous, but we use a work queue anyway
2485  * to guarantee that even unprivileged user processes can set up a
2486  * socket on a privileged port.
2487  *
2488  * If a UDP socket connect fails, the delay behavior here prevents
2489  * retry floods (hard mounts).
2490  */
2491 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2492 {
2493         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2494         unsigned long delay = 0;
2495
2496         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2497
2498         if (transport->sock != NULL) {
2499                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2500                                 "seconds\n",
2501                                 xprt, xprt->reestablish_timeout / HZ);
2502
2503                 /* Start by resetting any existing state */
2504                 xs_reset_transport(transport);
2505
2506                 delay = xs_reconnect_delay(xprt);
2507                 xs_reconnect_backoff(xprt);
2508
2509         } else
2510                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2511
2512         queue_delayed_work(xprtiod_workqueue,
2513                         &transport->connect_worker,
2514                         delay);
2515 }
2516
2517 /**
2518  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2519  * @xprt: rpc_xprt struct containing statistics
2520  * @seq: output file
2521  *
2522  */
2523 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2524 {
2525         long idle_time = 0;
2526
2527         if (xprt_connected(xprt))
2528                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2529
2530         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2531                         "%llu %llu %lu %llu %llu\n",
2532                         xprt->stat.bind_count,
2533                         xprt->stat.connect_count,
2534                         xprt->stat.connect_time,
2535                         idle_time,
2536                         xprt->stat.sends,
2537                         xprt->stat.recvs,
2538                         xprt->stat.bad_xids,
2539                         xprt->stat.req_u,
2540                         xprt->stat.bklog_u,
2541                         xprt->stat.max_slots,
2542                         xprt->stat.sending_u,
2543                         xprt->stat.pending_u);
2544 }
2545
2546 /**
2547  * xs_udp_print_stats - display UDP socket-specifc stats
2548  * @xprt: rpc_xprt struct containing statistics
2549  * @seq: output file
2550  *
2551  */
2552 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2553 {
2554         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2555
2556         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2557                         "%lu %llu %llu\n",
2558                         transport->srcport,
2559                         xprt->stat.bind_count,
2560                         xprt->stat.sends,
2561                         xprt->stat.recvs,
2562                         xprt->stat.bad_xids,
2563                         xprt->stat.req_u,
2564                         xprt->stat.bklog_u,
2565                         xprt->stat.max_slots,
2566                         xprt->stat.sending_u,
2567                         xprt->stat.pending_u);
2568 }
2569
2570 /**
2571  * xs_tcp_print_stats - display TCP socket-specifc stats
2572  * @xprt: rpc_xprt struct containing statistics
2573  * @seq: output file
2574  *
2575  */
2576 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2577 {
2578         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2579         long idle_time = 0;
2580
2581         if (xprt_connected(xprt))
2582                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2583
2584         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2585                         "%llu %llu %lu %llu %llu\n",
2586                         transport->srcport,
2587                         xprt->stat.bind_count,
2588                         xprt->stat.connect_count,
2589                         xprt->stat.connect_time,
2590                         idle_time,
2591                         xprt->stat.sends,
2592                         xprt->stat.recvs,
2593                         xprt->stat.bad_xids,
2594                         xprt->stat.req_u,
2595                         xprt->stat.bklog_u,
2596                         xprt->stat.max_slots,
2597                         xprt->stat.sending_u,
2598                         xprt->stat.pending_u);
2599 }
2600
2601 /*
2602  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2603  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2604  * to use the server side send routines.
2605  */
2606 static int bc_malloc(struct rpc_task *task)
2607 {
2608         struct rpc_rqst *rqst = task->tk_rqstp;
2609         size_t size = rqst->rq_callsize;
2610         struct page *page;
2611         struct rpc_buffer *buf;
2612
2613         if (size > PAGE_SIZE - sizeof(struct rpc_buffer)) {
2614                 WARN_ONCE(1, "xprtsock: large bc buffer request (size %zu)\n",
2615                           size);
2616                 return -EINVAL;
2617         }
2618
2619         page = alloc_page(GFP_KERNEL);
2620         if (!page)
2621                 return -ENOMEM;
2622
2623         buf = page_address(page);
2624         buf->len = PAGE_SIZE;
2625
2626         rqst->rq_buffer = buf->data;
2627         rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
2628         return 0;
2629 }
2630
2631 /*
2632  * Free the space allocated in the bc_alloc routine
2633  */
2634 static void bc_free(struct rpc_task *task)
2635 {
2636         void *buffer = task->tk_rqstp->rq_buffer;
2637         struct rpc_buffer *buf;
2638
2639         buf = container_of(buffer, struct rpc_buffer, data);
2640         free_page((unsigned long)buf);
2641 }
2642
2643 /*
2644  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2645  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2646  */
2647 static int bc_sendto(struct rpc_rqst *req)
2648 {
2649         int len;
2650         struct xdr_buf *xbufp = &req->rq_snd_buf;
2651         struct rpc_xprt *xprt = req->rq_xprt;
2652         struct sock_xprt *transport =
2653                                 container_of(xprt, struct sock_xprt, xprt);
2654         struct socket *sock = transport->sock;
2655         unsigned long headoff;
2656         unsigned long tailoff;
2657
2658         xs_encode_stream_record_marker(xbufp);
2659
2660         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2661         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2662         len = svc_send_common(sock, xbufp,
2663                               virt_to_page(xbufp->head[0].iov_base), headoff,
2664                               xbufp->tail[0].iov_base, tailoff);
2665
2666         if (len != xbufp->len) {
2667                 printk(KERN_NOTICE "Error sending entire callback!\n");
2668                 len = -EAGAIN;
2669         }
2670
2671         return len;
2672 }
2673
2674 /*
2675  * The send routine. Borrows from svc_send
2676  */
2677 static int bc_send_request(struct rpc_task *task)
2678 {
2679         struct rpc_rqst *req = task->tk_rqstp;
2680         struct svc_xprt *xprt;
2681         int len;
2682
2683         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2684         /*
2685          * Get the server socket associated with this callback xprt
2686          */
2687         xprt = req->rq_xprt->bc_xprt;
2688
2689         /*
2690          * Grab the mutex to serialize data as the connection is shared
2691          * with the fore channel
2692          */
2693         if (!mutex_trylock(&xprt->xpt_mutex)) {
2694                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2695                 if (!mutex_trylock(&xprt->xpt_mutex))
2696                         return -EAGAIN;
2697                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2698         }
2699         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2700                 len = -ENOTCONN;
2701         else
2702                 len = bc_sendto(req);
2703         mutex_unlock(&xprt->xpt_mutex);
2704
2705         if (len > 0)
2706                 len = 0;
2707
2708         return len;
2709 }
2710
2711 /*
2712  * The close routine. Since this is client initiated, we do nothing
2713  */
2714
2715 static void bc_close(struct rpc_xprt *xprt)
2716 {
2717 }
2718
2719 /*
2720  * The xprt destroy routine. Again, because this connection is client
2721  * initiated, we do nothing
2722  */
2723
2724 static void bc_destroy(struct rpc_xprt *xprt)
2725 {
2726         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2727
2728         xs_xprt_free(xprt);
2729         module_put(THIS_MODULE);
2730 }
2731
2732 static const struct rpc_xprt_ops xs_local_ops = {
2733         .reserve_xprt           = xprt_reserve_xprt,
2734         .release_xprt           = xs_tcp_release_xprt,
2735         .alloc_slot             = xprt_alloc_slot,
2736         .rpcbind                = xs_local_rpcbind,
2737         .set_port               = xs_local_set_port,
2738         .connect                = xs_local_connect,
2739         .buf_alloc              = rpc_malloc,
2740         .buf_free               = rpc_free,
2741         .send_request           = xs_local_send_request,
2742         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2743         .close                  = xs_close,
2744         .destroy                = xs_destroy,
2745         .print_stats            = xs_local_print_stats,
2746         .enable_swap            = xs_enable_swap,
2747         .disable_swap           = xs_disable_swap,
2748 };
2749
2750 static const struct rpc_xprt_ops xs_udp_ops = {
2751         .set_buffer_size        = xs_udp_set_buffer_size,
2752         .reserve_xprt           = xprt_reserve_xprt_cong,
2753         .release_xprt           = xprt_release_xprt_cong,
2754         .alloc_slot             = xprt_alloc_slot,
2755         .rpcbind                = rpcb_getport_async,
2756         .set_port               = xs_set_port,
2757         .connect                = xs_connect,
2758         .buf_alloc              = rpc_malloc,
2759         .buf_free               = rpc_free,
2760         .send_request           = xs_udp_send_request,
2761         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2762         .timer                  = xs_udp_timer,
2763         .release_request        = xprt_release_rqst_cong,
2764         .close                  = xs_close,
2765         .destroy                = xs_destroy,
2766         .print_stats            = xs_udp_print_stats,
2767         .enable_swap            = xs_enable_swap,
2768         .disable_swap           = xs_disable_swap,
2769         .inject_disconnect      = xs_inject_disconnect,
2770 };
2771
2772 static const struct rpc_xprt_ops xs_tcp_ops = {
2773         .reserve_xprt           = xprt_reserve_xprt,
2774         .release_xprt           = xs_tcp_release_xprt,
2775         .alloc_slot             = xprt_lock_and_alloc_slot,
2776         .rpcbind                = rpcb_getport_async,
2777         .set_port               = xs_set_port,
2778         .connect                = xs_connect,
2779         .buf_alloc              = rpc_malloc,
2780         .buf_free               = rpc_free,
2781         .send_request           = xs_tcp_send_request,
2782         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2783         .close                  = xs_tcp_shutdown,
2784         .destroy                = xs_destroy,
2785         .set_connect_timeout    = xs_tcp_set_connect_timeout,
2786         .print_stats            = xs_tcp_print_stats,
2787         .enable_swap            = xs_enable_swap,
2788         .disable_swap           = xs_disable_swap,
2789         .inject_disconnect      = xs_inject_disconnect,
2790 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2791         .bc_setup               = xprt_setup_bc,
2792         .bc_up                  = xs_tcp_bc_up,
2793         .bc_maxpayload          = xs_tcp_bc_maxpayload,
2794         .bc_free_rqst           = xprt_free_bc_rqst,
2795         .bc_destroy             = xprt_destroy_bc,
2796 #endif
2797 };
2798
2799 /*
2800  * The rpc_xprt_ops for the server backchannel
2801  */
2802
2803 static const struct rpc_xprt_ops bc_tcp_ops = {
2804         .reserve_xprt           = xprt_reserve_xprt,
2805         .release_xprt           = xprt_release_xprt,
2806         .alloc_slot             = xprt_alloc_slot,
2807         .buf_alloc              = bc_malloc,
2808         .buf_free               = bc_free,
2809         .send_request           = bc_send_request,
2810         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2811         .close                  = bc_close,
2812         .destroy                = bc_destroy,
2813         .print_stats            = xs_tcp_print_stats,
2814         .enable_swap            = xs_enable_swap,
2815         .disable_swap           = xs_disable_swap,
2816         .inject_disconnect      = xs_inject_disconnect,
2817 };
2818
2819 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2820 {
2821         static const struct sockaddr_in sin = {
2822                 .sin_family             = AF_INET,
2823                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2824         };
2825         static const struct sockaddr_in6 sin6 = {
2826                 .sin6_family            = AF_INET6,
2827                 .sin6_addr              = IN6ADDR_ANY_INIT,
2828         };
2829
2830         switch (family) {
2831         case AF_LOCAL:
2832                 break;
2833         case AF_INET:
2834                 memcpy(sap, &sin, sizeof(sin));
2835                 break;
2836         case AF_INET6:
2837                 memcpy(sap, &sin6, sizeof(sin6));
2838                 break;
2839         default:
2840                 dprintk("RPC:       %s: Bad address family\n", __func__);
2841                 return -EAFNOSUPPORT;
2842         }
2843         return 0;
2844 }
2845
2846 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2847                                       unsigned int slot_table_size,
2848                                       unsigned int max_slot_table_size)
2849 {
2850         struct rpc_xprt *xprt;
2851         struct sock_xprt *new;
2852
2853         if (args->addrlen > sizeof(xprt->addr)) {
2854                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2855                 return ERR_PTR(-EBADF);
2856         }
2857
2858         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2859                         max_slot_table_size);
2860         if (xprt == NULL) {
2861                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2862                                 "rpc_xprt\n");
2863                 return ERR_PTR(-ENOMEM);
2864         }
2865
2866         new = container_of(xprt, struct sock_xprt, xprt);
2867         mutex_init(&new->recv_mutex);
2868         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2869         xprt->addrlen = args->addrlen;
2870         if (args->srcaddr)
2871                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2872         else {
2873                 int err;
2874                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2875                                         (struct sockaddr *)&new->srcaddr);
2876                 if (err != 0) {
2877                         xprt_free(xprt);
2878                         return ERR_PTR(err);
2879                 }
2880         }
2881
2882         return xprt;
2883 }
2884
2885 static const struct rpc_timeout xs_local_default_timeout = {
2886         .to_initval = 10 * HZ,
2887         .to_maxval = 10 * HZ,
2888         .to_retries = 2,
2889 };
2890
2891 /**
2892  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2893  * @args: rpc transport creation arguments
2894  *
2895  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2896  */
2897 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2898 {
2899         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2900         struct sock_xprt *transport;
2901         struct rpc_xprt *xprt;
2902         struct rpc_xprt *ret;
2903
2904         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2905                         xprt_max_tcp_slot_table_entries);
2906         if (IS_ERR(xprt))
2907                 return xprt;
2908         transport = container_of(xprt, struct sock_xprt, xprt);
2909
2910         xprt->prot = 0;
2911         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2912         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2913
2914         xprt->bind_timeout = XS_BIND_TO;
2915         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2916         xprt->idle_timeout = XS_IDLE_DISC_TO;
2917
2918         xprt->ops = &xs_local_ops;
2919         xprt->timeout = &xs_local_default_timeout;
2920
2921         INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2922         INIT_DELAYED_WORK(&transport->connect_worker,
2923                         xs_dummy_setup_socket);
2924
2925         switch (sun->sun_family) {
2926         case AF_LOCAL:
2927                 if (sun->sun_path[0] != '/') {
2928                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2929                                         sun->sun_path);
2930                         ret = ERR_PTR(-EINVAL);
2931                         goto out_err;
2932                 }
2933                 xprt_set_bound(xprt);
2934                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2935                 ret = ERR_PTR(xs_local_setup_socket(transport));
2936                 if (ret)
2937                         goto out_err;
2938                 break;
2939         default:
2940                 ret = ERR_PTR(-EAFNOSUPPORT);
2941                 goto out_err;
2942         }
2943
2944         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2945                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2946
2947         if (try_module_get(THIS_MODULE))
2948                 return xprt;
2949         ret = ERR_PTR(-EINVAL);
2950 out_err:
2951         xs_xprt_free(xprt);
2952         return ret;
2953 }
2954
2955 static const struct rpc_timeout xs_udp_default_timeout = {
2956         .to_initval = 5 * HZ,
2957         .to_maxval = 30 * HZ,
2958         .to_increment = 5 * HZ,
2959         .to_retries = 5,
2960 };
2961
2962 /**
2963  * xs_setup_udp - Set up transport to use a UDP socket
2964  * @args: rpc transport creation arguments
2965  *
2966  */
2967 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2968 {
2969         struct sockaddr *addr = args->dstaddr;
2970         struct rpc_xprt *xprt;
2971         struct sock_xprt *transport;
2972         struct rpc_xprt *ret;
2973
2974         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2975                         xprt_udp_slot_table_entries);
2976         if (IS_ERR(xprt))
2977                 return xprt;
2978         transport = container_of(xprt, struct sock_xprt, xprt);
2979
2980         xprt->prot = IPPROTO_UDP;
2981         xprt->tsh_size = 0;
2982         /* XXX: header size can vary due to auth type, IPv6, etc. */
2983         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2984
2985         xprt->bind_timeout = XS_BIND_TO;
2986         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2987         xprt->idle_timeout = XS_IDLE_DISC_TO;
2988
2989         xprt->ops = &xs_udp_ops;
2990
2991         xprt->timeout = &xs_udp_default_timeout;
2992
2993         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2994         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2995
2996         switch (addr->sa_family) {
2997         case AF_INET:
2998                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2999                         xprt_set_bound(xprt);
3000
3001                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
3002                 break;
3003         case AF_INET6:
3004                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3005                         xprt_set_bound(xprt);
3006
3007                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
3008                 break;
3009         default:
3010                 ret = ERR_PTR(-EAFNOSUPPORT);
3011                 goto out_err;
3012         }
3013
3014         if (xprt_bound(xprt))
3015                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3016                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3017                                 xprt->address_strings[RPC_DISPLAY_PORT],
3018                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3019         else
3020                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3021                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3022                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3023
3024         if (try_module_get(THIS_MODULE))
3025                 return xprt;
3026         ret = ERR_PTR(-EINVAL);
3027 out_err:
3028         xs_xprt_free(xprt);
3029         return ret;
3030 }
3031
3032 static const struct rpc_timeout xs_tcp_default_timeout = {
3033         .to_initval = 60 * HZ,
3034         .to_maxval = 60 * HZ,
3035         .to_retries = 2,
3036 };
3037
3038 /**
3039  * xs_setup_tcp - Set up transport to use a TCP socket
3040  * @args: rpc transport creation arguments
3041  *
3042  */
3043 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
3044 {
3045         struct sockaddr *addr = args->dstaddr;
3046         struct rpc_xprt *xprt;
3047         struct sock_xprt *transport;
3048         struct rpc_xprt *ret;
3049         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
3050
3051         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
3052                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
3053
3054         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3055                         max_slot_table_size);
3056         if (IS_ERR(xprt))
3057                 return xprt;
3058         transport = container_of(xprt, struct sock_xprt, xprt);
3059
3060         xprt->prot = IPPROTO_TCP;
3061         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3062         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3063
3064         xprt->bind_timeout = XS_BIND_TO;
3065         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
3066         xprt->idle_timeout = XS_IDLE_DISC_TO;
3067
3068         xprt->ops = &xs_tcp_ops;
3069         xprt->timeout = &xs_tcp_default_timeout;
3070
3071         xprt->max_reconnect_timeout = xprt->timeout->to_maxval;
3072         xprt->connect_timeout = xprt->timeout->to_initval *
3073                 (xprt->timeout->to_retries + 1);
3074
3075         INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
3076         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
3077
3078         switch (addr->sa_family) {
3079         case AF_INET:
3080                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
3081                         xprt_set_bound(xprt);
3082
3083                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
3084                 break;
3085         case AF_INET6:
3086                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
3087                         xprt_set_bound(xprt);
3088
3089                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
3090                 break;
3091         default:
3092                 ret = ERR_PTR(-EAFNOSUPPORT);
3093                 goto out_err;
3094         }
3095
3096         if (xprt_bound(xprt))
3097                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3098                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3099                                 xprt->address_strings[RPC_DISPLAY_PORT],
3100                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3101         else
3102                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
3103                                 xprt->address_strings[RPC_DISPLAY_ADDR],
3104                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
3105
3106         if (try_module_get(THIS_MODULE))
3107                 return xprt;
3108         ret = ERR_PTR(-EINVAL);
3109 out_err:
3110         xs_xprt_free(xprt);
3111         return ret;
3112 }
3113
3114 /**
3115  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
3116  * @args: rpc transport creation arguments
3117  *
3118  */
3119 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
3120 {
3121         struct sockaddr *addr = args->dstaddr;
3122         struct rpc_xprt *xprt;
3123         struct sock_xprt *transport;
3124         struct svc_sock *bc_sock;
3125         struct rpc_xprt *ret;
3126
3127         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
3128                         xprt_tcp_slot_table_entries);
3129         if (IS_ERR(xprt))
3130                 return xprt;
3131         transport = container_of(xprt, struct sock_xprt, xprt);
3132
3133         xprt->prot = IPPROTO_TCP;
3134         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3135         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3136         xprt->timeout = &xs_tcp_default_timeout;
3137
3138         /* backchannel */
3139         xprt_set_bound(xprt);
3140         xprt->bind_timeout = 0;
3141         xprt->reestablish_timeout = 0;
3142         xprt->idle_timeout = 0;
3143
3144         xprt->ops = &bc_tcp_ops;
3145
3146         switch (addr->sa_family) {
3147         case AF_INET:
3148                 xs_format_peer_addresses(xprt, "tcp",
3149                                          RPCBIND_NETID_TCP);
3150                 break;
3151         case AF_INET6:
3152                 xs_format_peer_addresses(xprt, "tcp",
3153                                    RPCBIND_NETID_TCP6);
3154                 break;
3155         default:
3156                 ret = ERR_PTR(-EAFNOSUPPORT);
3157                 goto out_err;
3158         }
3159
3160         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3161                         xprt->address_strings[RPC_DISPLAY_ADDR],
3162                         xprt->address_strings[RPC_DISPLAY_PORT],
3163                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3164
3165         /*
3166          * Once we've associated a backchannel xprt with a connection,
3167          * we want to keep it around as long as the connection lasts,
3168          * in case we need to start using it for a backchannel again;
3169          * this reference won't be dropped until bc_xprt is destroyed.
3170          */
3171         xprt_get(xprt);
3172         args->bc_xprt->xpt_bc_xprt = xprt;
3173         xprt->bc_xprt = args->bc_xprt;
3174         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3175         transport->sock = bc_sock->sk_sock;
3176         transport->inet = bc_sock->sk_sk;
3177
3178         /*
3179          * Since we don't want connections for the backchannel, we set
3180          * the xprt status to connected
3181          */
3182         xprt_set_connected(xprt);
3183
3184         if (try_module_get(THIS_MODULE))
3185                 return xprt;
3186
3187         args->bc_xprt->xpt_bc_xprt = NULL;
3188         args->bc_xprt->xpt_bc_xps = NULL;
3189         xprt_put(xprt);
3190         ret = ERR_PTR(-EINVAL);
3191 out_err:
3192         xs_xprt_free(xprt);
3193         return ret;
3194 }
3195
3196 static struct xprt_class        xs_local_transport = {
3197         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3198         .name           = "named UNIX socket",
3199         .owner          = THIS_MODULE,
3200         .ident          = XPRT_TRANSPORT_LOCAL,
3201         .setup          = xs_setup_local,
3202 };
3203
3204 static struct xprt_class        xs_udp_transport = {
3205         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3206         .name           = "udp",
3207         .owner          = THIS_MODULE,
3208         .ident          = XPRT_TRANSPORT_UDP,
3209         .setup          = xs_setup_udp,
3210 };
3211
3212 static struct xprt_class        xs_tcp_transport = {
3213         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3214         .name           = "tcp",
3215         .owner          = THIS_MODULE,
3216         .ident          = XPRT_TRANSPORT_TCP,
3217         .setup          = xs_setup_tcp,
3218 };
3219
3220 static struct xprt_class        xs_bc_tcp_transport = {
3221         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3222         .name           = "tcp NFSv4.1 backchannel",
3223         .owner          = THIS_MODULE,
3224         .ident          = XPRT_TRANSPORT_BC_TCP,
3225         .setup          = xs_setup_bc_tcp,
3226 };
3227
3228 /**
3229  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3230  *
3231  */
3232 int init_socket_xprt(void)
3233 {
3234 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3235         if (!sunrpc_table_header)
3236                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3237 #endif
3238
3239         xprt_register_transport(&xs_local_transport);
3240         xprt_register_transport(&xs_udp_transport);
3241         xprt_register_transport(&xs_tcp_transport);
3242         xprt_register_transport(&xs_bc_tcp_transport);
3243
3244         return 0;
3245 }
3246
3247 /**
3248  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3249  *
3250  */
3251 void cleanup_socket_xprt(void)
3252 {
3253 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3254         if (sunrpc_table_header) {
3255                 unregister_sysctl_table(sunrpc_table_header);
3256                 sunrpc_table_header = NULL;
3257         }
3258 #endif
3259
3260         xprt_unregister_transport(&xs_local_transport);
3261         xprt_unregister_transport(&xs_udp_transport);
3262         xprt_unregister_transport(&xs_tcp_transport);
3263         xprt_unregister_transport(&xs_bc_tcp_transport);
3264 }
3265
3266 static int param_set_uint_minmax(const char *val,
3267                 const struct kernel_param *kp,
3268                 unsigned int min, unsigned int max)
3269 {
3270         unsigned int num;
3271         int ret;
3272
3273         if (!val)
3274                 return -EINVAL;
3275         ret = kstrtouint(val, 0, &num);
3276         if (ret)
3277                 return ret;
3278         if (num < min || num > max)
3279                 return -EINVAL;
3280         *((unsigned int *)kp->arg) = num;
3281         return 0;
3282 }
3283
3284 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3285 {
3286         if (kp->arg == &xprt_min_resvport)
3287                 return param_set_uint_minmax(val, kp,
3288                         RPC_MIN_RESVPORT,
3289                         xprt_max_resvport);
3290         return param_set_uint_minmax(val, kp,
3291                         xprt_min_resvport,
3292                         RPC_MAX_RESVPORT);
3293 }
3294
3295 static const struct kernel_param_ops param_ops_portnr = {
3296         .set = param_set_portnr,
3297         .get = param_get_uint,
3298 };
3299
3300 #define param_check_portnr(name, p) \
3301         __param_check(name, p, unsigned int);
3302
3303 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3304 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3305
3306 static int param_set_slot_table_size(const char *val,
3307                                      const struct kernel_param *kp)
3308 {
3309         return param_set_uint_minmax(val, kp,
3310                         RPC_MIN_SLOT_TABLE,
3311                         RPC_MAX_SLOT_TABLE);
3312 }
3313
3314 static const struct kernel_param_ops param_ops_slot_table_size = {
3315         .set = param_set_slot_table_size,
3316         .get = param_get_uint,
3317 };
3318
3319 #define param_check_slot_table_size(name, p) \
3320         __param_check(name, p, unsigned int);
3321
3322 static int param_set_max_slot_table_size(const char *val,
3323                                      const struct kernel_param *kp)
3324 {
3325         return param_set_uint_minmax(val, kp,
3326                         RPC_MIN_SLOT_TABLE,
3327                         RPC_MAX_SLOT_TABLE_LIMIT);
3328 }
3329
3330 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3331         .set = param_set_max_slot_table_size,
3332         .get = param_get_uint,
3333 };
3334
3335 #define param_check_max_slot_table_size(name, p) \
3336         __param_check(name, p, unsigned int);
3337
3338 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3339                    slot_table_size, 0644);
3340 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3341                    max_slot_table_size, 0644);
3342 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3343                    slot_table_size, 0644);
3344