1 /* 2 * linux/net/sunrpc/xprtsock.c 3 * 4 * Client-side transport implementation for sockets. 5 * 6 * TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com> 7 * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com> 8 * TCP NFS related read + write fixes 9 * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie> 10 * 11 * Rewrite of larges part of the code in order to stabilize TCP stuff. 12 * Fix behaviour when socket buffer is full. 13 * (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no> 14 * 15 * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com> 16 */ 17 18 #include <linux/types.h> 19 #include <linux/slab.h> 20 #include <linux/capability.h> 21 #include <linux/sched.h> 22 #include <linux/pagemap.h> 23 #include <linux/errno.h> 24 #include <linux/socket.h> 25 #include <linux/in.h> 26 #include <linux/net.h> 27 #include <linux/mm.h> 28 #include <linux/udp.h> 29 #include <linux/tcp.h> 30 #include <linux/sunrpc/clnt.h> 31 #include <linux/file.h> 32 33 #include <net/sock.h> 34 #include <net/checksum.h> 35 #include <net/udp.h> 36 #include <net/tcp.h> 37 38 /* 39 * xprtsock tunables 40 */ 41 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE; 42 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE; 43 44 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT; 45 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT; 46 47 /* 48 * How many times to try sending a request on a socket before waiting 49 * for the socket buffer to clear. 50 */ 51 #define XS_SENDMSG_RETRY (10U) 52 53 /* 54 * Time out for an RPC UDP socket connect. UDP socket connects are 55 * synchronous, but we set a timeout anyway in case of resource 56 * exhaustion on the local host. 57 */ 58 #define XS_UDP_CONN_TO (5U * HZ) 59 60 /* 61 * Wait duration for an RPC TCP connection to be established. Solaris 62 * NFS over TCP uses 60 seconds, for example, which is in line with how 63 * long a server takes to reboot. 64 */ 65 #define XS_TCP_CONN_TO (60U * HZ) 66 67 /* 68 * Wait duration for a reply from the RPC portmapper. 69 */ 70 #define XS_BIND_TO (60U * HZ) 71 72 /* 73 * Delay if a UDP socket connect error occurs. This is most likely some 74 * kind of resource problem on the local host. 75 */ 76 #define XS_UDP_REEST_TO (2U * HZ) 77 78 /* 79 * The reestablish timeout allows clients to delay for a bit before attempting 80 * to reconnect to a server that just dropped our connection. 81 * 82 * We implement an exponential backoff when trying to reestablish a TCP 83 * transport connection with the server. Some servers like to drop a TCP 84 * connection when they are overworked, so we start with a short timeout and 85 * increase over time if the server is down or not responding. 86 */ 87 #define XS_TCP_INIT_REEST_TO (3U * HZ) 88 #define XS_TCP_MAX_REEST_TO (5U * 60 * HZ) 89 90 /* 91 * TCP idle timeout; client drops the transport socket if it is idle 92 * for this long. Note that we also timeout UDP sockets to prevent 93 * holding port numbers when there is no RPC traffic. 94 */ 95 #define XS_IDLE_DISC_TO (5U * 60 * HZ) 96 97 #ifdef RPC_DEBUG 98 # undef RPC_DEBUG_DATA 99 # define RPCDBG_FACILITY RPCDBG_TRANS 100 #endif 101 102 #ifdef RPC_DEBUG_DATA 103 static void xs_pktdump(char *msg, u32 *packet, unsigned int count) 104 { 105 u8 *buf = (u8 *) packet; 106 int j; 107 108 dprintk("RPC: %s\n", msg); 109 for (j = 0; j < count && j < 128; j += 4) { 110 if (!(j & 31)) { 111 if (j) 112 dprintk("\n"); 113 dprintk("0x%04x ", j); 114 } 115 dprintk("%02x%02x%02x%02x ", 116 buf[j], buf[j+1], buf[j+2], buf[j+3]); 117 } 118 dprintk("\n"); 119 } 120 #else 121 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count) 122 { 123 /* NOP */ 124 } 125 #endif 126 127 #define XS_SENDMSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL) 128 129 static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len) 130 { 131 struct kvec iov = { 132 .iov_base = xdr->head[0].iov_base + base, 133 .iov_len = len - base, 134 }; 135 struct msghdr msg = { 136 .msg_name = addr, 137 .msg_namelen = addrlen, 138 .msg_flags = XS_SENDMSG_FLAGS, 139 }; 140 141 if (xdr->len > len) 142 msg.msg_flags |= MSG_MORE; 143 144 if (likely(iov.iov_len)) 145 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len); 146 return kernel_sendmsg(sock, &msg, NULL, 0, 0); 147 } 148 149 static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len) 150 { 151 struct kvec iov = { 152 .iov_base = xdr->tail[0].iov_base + base, 153 .iov_len = len - base, 154 }; 155 struct msghdr msg = { 156 .msg_flags = XS_SENDMSG_FLAGS, 157 }; 158 159 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len); 160 } 161 162 /** 163 * xs_sendpages - write pages directly to a socket 164 * @sock: socket to send on 165 * @addr: UDP only -- address of destination 166 * @addrlen: UDP only -- length of destination address 167 * @xdr: buffer containing this request 168 * @base: starting position in the buffer 169 * 170 */ 171 static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base) 172 { 173 struct page **ppage = xdr->pages; 174 unsigned int len, pglen = xdr->page_len; 175 int err, ret = 0; 176 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int); 177 178 if (unlikely(!sock)) 179 return -ENOTCONN; 180 181 clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags); 182 183 len = xdr->head[0].iov_len; 184 if (base < len || (addr != NULL && base == 0)) { 185 err = xs_send_head(sock, addr, addrlen, xdr, base, len); 186 if (ret == 0) 187 ret = err; 188 else if (err > 0) 189 ret += err; 190 if (err != (len - base)) 191 goto out; 192 base = 0; 193 } else 194 base -= len; 195 196 if (unlikely(pglen == 0)) 197 goto copy_tail; 198 if (unlikely(base >= pglen)) { 199 base -= pglen; 200 goto copy_tail; 201 } 202 if (base || xdr->page_base) { 203 pglen -= base; 204 base += xdr->page_base; 205 ppage += base >> PAGE_CACHE_SHIFT; 206 base &= ~PAGE_CACHE_MASK; 207 } 208 209 sendpage = sock->ops->sendpage ? : sock_no_sendpage; 210 do { 211 int flags = XS_SENDMSG_FLAGS; 212 213 len = PAGE_CACHE_SIZE; 214 if (base) 215 len -= base; 216 if (pglen < len) 217 len = pglen; 218 219 if (pglen != len || xdr->tail[0].iov_len != 0) 220 flags |= MSG_MORE; 221 222 /* Hmm... We might be dealing with highmem pages */ 223 if (PageHighMem(*ppage)) 224 sendpage = sock_no_sendpage; 225 err = sendpage(sock, *ppage, base, len, flags); 226 if (ret == 0) 227 ret = err; 228 else if (err > 0) 229 ret += err; 230 if (err != len) 231 goto out; 232 base = 0; 233 ppage++; 234 } while ((pglen -= len) != 0); 235 copy_tail: 236 len = xdr->tail[0].iov_len; 237 if (base < len) { 238 err = xs_send_tail(sock, xdr, base, len); 239 if (ret == 0) 240 ret = err; 241 else if (err > 0) 242 ret += err; 243 } 244 out: 245 return ret; 246 } 247 248 /** 249 * xs_nospace - place task on wait queue if transmit was incomplete 250 * @task: task to put to sleep 251 * 252 */ 253 static void xs_nospace(struct rpc_task *task) 254 { 255 struct rpc_rqst *req = task->tk_rqstp; 256 struct rpc_xprt *xprt = req->rq_xprt; 257 258 dprintk("RPC: %4d xmit incomplete (%u left of %u)\n", 259 task->tk_pid, req->rq_slen - req->rq_bytes_sent, 260 req->rq_slen); 261 262 if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) { 263 /* Protect against races with write_space */ 264 spin_lock_bh(&xprt->transport_lock); 265 266 /* Don't race with disconnect */ 267 if (!xprt_connected(xprt)) 268 task->tk_status = -ENOTCONN; 269 else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags)) 270 xprt_wait_for_buffer_space(task); 271 272 spin_unlock_bh(&xprt->transport_lock); 273 } else 274 /* Keep holding the socket if it is blocked */ 275 rpc_delay(task, HZ>>4); 276 } 277 278 /** 279 * xs_udp_send_request - write an RPC request to a UDP socket 280 * @task: address of RPC task that manages the state of an RPC request 281 * 282 * Return values: 283 * 0: The request has been sent 284 * EAGAIN: The socket was blocked, please call again later to 285 * complete the request 286 * ENOTCONN: Caller needs to invoke connect logic then call again 287 * other: Some other error occured, the request was not sent 288 */ 289 static int xs_udp_send_request(struct rpc_task *task) 290 { 291 struct rpc_rqst *req = task->tk_rqstp; 292 struct rpc_xprt *xprt = req->rq_xprt; 293 struct xdr_buf *xdr = &req->rq_snd_buf; 294 int status; 295 296 xs_pktdump("packet data:", 297 req->rq_svec->iov_base, 298 req->rq_svec->iov_len); 299 300 req->rq_xtime = jiffies; 301 status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr, 302 sizeof(xprt->addr), xdr, req->rq_bytes_sent); 303 304 dprintk("RPC: xs_udp_send_request(%u) = %d\n", 305 xdr->len - req->rq_bytes_sent, status); 306 307 if (likely(status >= (int) req->rq_slen)) 308 return 0; 309 310 /* Still some bytes left; set up for a retry later. */ 311 if (status > 0) 312 status = -EAGAIN; 313 314 switch (status) { 315 case -ENETUNREACH: 316 case -EPIPE: 317 case -ECONNREFUSED: 318 /* When the server has died, an ICMP port unreachable message 319 * prompts ECONNREFUSED. */ 320 break; 321 case -EAGAIN: 322 xs_nospace(task); 323 break; 324 default: 325 dprintk("RPC: sendmsg returned unrecognized error %d\n", 326 -status); 327 break; 328 } 329 330 return status; 331 } 332 333 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf) 334 { 335 u32 reclen = buf->len - sizeof(rpc_fraghdr); 336 rpc_fraghdr *base = buf->head[0].iov_base; 337 *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen); 338 } 339 340 /** 341 * xs_tcp_send_request - write an RPC request to a TCP socket 342 * @task: address of RPC task that manages the state of an RPC request 343 * 344 * Return values: 345 * 0: The request has been sent 346 * EAGAIN: The socket was blocked, please call again later to 347 * complete the request 348 * ENOTCONN: Caller needs to invoke connect logic then call again 349 * other: Some other error occured, the request was not sent 350 * 351 * XXX: In the case of soft timeouts, should we eventually give up 352 * if sendmsg is not able to make progress? 353 */ 354 static int xs_tcp_send_request(struct rpc_task *task) 355 { 356 struct rpc_rqst *req = task->tk_rqstp; 357 struct rpc_xprt *xprt = req->rq_xprt; 358 struct xdr_buf *xdr = &req->rq_snd_buf; 359 int status, retry = 0; 360 361 xs_encode_tcp_record_marker(&req->rq_snd_buf); 362 363 xs_pktdump("packet data:", 364 req->rq_svec->iov_base, 365 req->rq_svec->iov_len); 366 367 /* Continue transmitting the packet/record. We must be careful 368 * to cope with writespace callbacks arriving _after_ we have 369 * called sendmsg(). */ 370 while (1) { 371 req->rq_xtime = jiffies; 372 status = xs_sendpages(xprt->sock, NULL, 0, xdr, 373 req->rq_bytes_sent); 374 375 dprintk("RPC: xs_tcp_send_request(%u) = %d\n", 376 xdr->len - req->rq_bytes_sent, status); 377 378 if (unlikely(status < 0)) 379 break; 380 381 /* If we've sent the entire packet, immediately 382 * reset the count of bytes sent. */ 383 req->rq_bytes_sent += status; 384 if (likely(req->rq_bytes_sent >= req->rq_slen)) { 385 req->rq_bytes_sent = 0; 386 return 0; 387 } 388 389 status = -EAGAIN; 390 if (retry++ > XS_SENDMSG_RETRY) 391 break; 392 } 393 394 switch (status) { 395 case -EAGAIN: 396 xs_nospace(task); 397 break; 398 case -ECONNREFUSED: 399 case -ECONNRESET: 400 case -ENOTCONN: 401 case -EPIPE: 402 status = -ENOTCONN; 403 break; 404 default: 405 dprintk("RPC: sendmsg returned unrecognized error %d\n", 406 -status); 407 xprt_disconnect(xprt); 408 break; 409 } 410 411 return status; 412 } 413 414 /** 415 * xs_close - close a socket 416 * @xprt: transport 417 * 418 * This is used when all requests are complete; ie, no DRC state remains 419 * on the server we want to save. 420 */ 421 static void xs_close(struct rpc_xprt *xprt) 422 { 423 struct socket *sock = xprt->sock; 424 struct sock *sk = xprt->inet; 425 426 if (!sk) 427 return; 428 429 dprintk("RPC: xs_close xprt %p\n", xprt); 430 431 write_lock_bh(&sk->sk_callback_lock); 432 xprt->inet = NULL; 433 xprt->sock = NULL; 434 435 sk->sk_user_data = NULL; 436 sk->sk_data_ready = xprt->old_data_ready; 437 sk->sk_state_change = xprt->old_state_change; 438 sk->sk_write_space = xprt->old_write_space; 439 write_unlock_bh(&sk->sk_callback_lock); 440 441 sk->sk_no_check = 0; 442 443 sock_release(sock); 444 } 445 446 /** 447 * xs_destroy - prepare to shutdown a transport 448 * @xprt: doomed transport 449 * 450 */ 451 static void xs_destroy(struct rpc_xprt *xprt) 452 { 453 dprintk("RPC: xs_destroy xprt %p\n", xprt); 454 455 cancel_delayed_work(&xprt->connect_worker); 456 flush_scheduled_work(); 457 458 xprt_disconnect(xprt); 459 xs_close(xprt); 460 kfree(xprt->slot); 461 } 462 463 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk) 464 { 465 return (struct rpc_xprt *) sk->sk_user_data; 466 } 467 468 /** 469 * xs_udp_data_ready - "data ready" callback for UDP sockets 470 * @sk: socket with data to read 471 * @len: how much data to read 472 * 473 */ 474 static void xs_udp_data_ready(struct sock *sk, int len) 475 { 476 struct rpc_task *task; 477 struct rpc_xprt *xprt; 478 struct rpc_rqst *rovr; 479 struct sk_buff *skb; 480 int err, repsize, copied; 481 u32 _xid, *xp; 482 483 read_lock(&sk->sk_callback_lock); 484 dprintk("RPC: xs_udp_data_ready...\n"); 485 if (!(xprt = xprt_from_sock(sk))) 486 goto out; 487 488 if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL) 489 goto out; 490 491 if (xprt->shutdown) 492 goto dropit; 493 494 repsize = skb->len - sizeof(struct udphdr); 495 if (repsize < 4) { 496 dprintk("RPC: impossible RPC reply size %d!\n", repsize); 497 goto dropit; 498 } 499 500 /* Copy the XID from the skb... */ 501 xp = skb_header_pointer(skb, sizeof(struct udphdr), 502 sizeof(_xid), &_xid); 503 if (xp == NULL) 504 goto dropit; 505 506 /* Look up and lock the request corresponding to the given XID */ 507 spin_lock(&xprt->transport_lock); 508 rovr = xprt_lookup_rqst(xprt, *xp); 509 if (!rovr) 510 goto out_unlock; 511 task = rovr->rq_task; 512 513 if ((copied = rovr->rq_private_buf.buflen) > repsize) 514 copied = repsize; 515 516 /* Suck it into the iovec, verify checksum if not done by hw. */ 517 if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) 518 goto out_unlock; 519 520 /* Something worked... */ 521 dst_confirm(skb->dst); 522 523 xprt_adjust_cwnd(task, copied); 524 xprt_update_rtt(task); 525 xprt_complete_rqst(task, copied); 526 527 out_unlock: 528 spin_unlock(&xprt->transport_lock); 529 dropit: 530 skb_free_datagram(sk, skb); 531 out: 532 read_unlock(&sk->sk_callback_lock); 533 } 534 535 static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len) 536 { 537 if (len > desc->count) 538 len = desc->count; 539 if (skb_copy_bits(desc->skb, desc->offset, p, len)) { 540 dprintk("RPC: failed to copy %zu bytes from skb. %zu bytes remain\n", 541 len, desc->count); 542 return 0; 543 } 544 desc->offset += len; 545 desc->count -= len; 546 dprintk("RPC: copied %zu bytes from skb. %zu bytes remain\n", 547 len, desc->count); 548 return len; 549 } 550 551 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc) 552 { 553 size_t len, used; 554 char *p; 555 556 p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset; 557 len = sizeof(xprt->tcp_recm) - xprt->tcp_offset; 558 used = xs_tcp_copy_data(desc, p, len); 559 xprt->tcp_offset += used; 560 if (used != len) 561 return; 562 563 xprt->tcp_reclen = ntohl(xprt->tcp_recm); 564 if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT) 565 xprt->tcp_flags |= XPRT_LAST_FRAG; 566 else 567 xprt->tcp_flags &= ~XPRT_LAST_FRAG; 568 xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK; 569 570 xprt->tcp_flags &= ~XPRT_COPY_RECM; 571 xprt->tcp_offset = 0; 572 573 /* Sanity check of the record length */ 574 if (unlikely(xprt->tcp_reclen < 4)) { 575 dprintk("RPC: invalid TCP record fragment length\n"); 576 xprt_disconnect(xprt); 577 return; 578 } 579 dprintk("RPC: reading TCP record fragment of length %d\n", 580 xprt->tcp_reclen); 581 } 582 583 static void xs_tcp_check_recm(struct rpc_xprt *xprt) 584 { 585 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n", 586 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags); 587 if (xprt->tcp_offset == xprt->tcp_reclen) { 588 xprt->tcp_flags |= XPRT_COPY_RECM; 589 xprt->tcp_offset = 0; 590 if (xprt->tcp_flags & XPRT_LAST_FRAG) { 591 xprt->tcp_flags &= ~XPRT_COPY_DATA; 592 xprt->tcp_flags |= XPRT_COPY_XID; 593 xprt->tcp_copied = 0; 594 } 595 } 596 } 597 598 static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc) 599 { 600 size_t len, used; 601 char *p; 602 603 len = sizeof(xprt->tcp_xid) - xprt->tcp_offset; 604 dprintk("RPC: reading XID (%Zu bytes)\n", len); 605 p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset; 606 used = xs_tcp_copy_data(desc, p, len); 607 xprt->tcp_offset += used; 608 if (used != len) 609 return; 610 xprt->tcp_flags &= ~XPRT_COPY_XID; 611 xprt->tcp_flags |= XPRT_COPY_DATA; 612 xprt->tcp_copied = 4; 613 dprintk("RPC: reading reply for XID %08x\n", 614 ntohl(xprt->tcp_xid)); 615 xs_tcp_check_recm(xprt); 616 } 617 618 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc) 619 { 620 struct rpc_rqst *req; 621 struct xdr_buf *rcvbuf; 622 size_t len; 623 ssize_t r; 624 625 /* Find and lock the request corresponding to this xid */ 626 spin_lock(&xprt->transport_lock); 627 req = xprt_lookup_rqst(xprt, xprt->tcp_xid); 628 if (!req) { 629 xprt->tcp_flags &= ~XPRT_COPY_DATA; 630 dprintk("RPC: XID %08x request not found!\n", 631 ntohl(xprt->tcp_xid)); 632 spin_unlock(&xprt->transport_lock); 633 return; 634 } 635 636 rcvbuf = &req->rq_private_buf; 637 len = desc->count; 638 if (len > xprt->tcp_reclen - xprt->tcp_offset) { 639 skb_reader_t my_desc; 640 641 len = xprt->tcp_reclen - xprt->tcp_offset; 642 memcpy(&my_desc, desc, sizeof(my_desc)); 643 my_desc.count = len; 644 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied, 645 &my_desc, xs_tcp_copy_data); 646 desc->count -= r; 647 desc->offset += r; 648 } else 649 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied, 650 desc, xs_tcp_copy_data); 651 652 if (r > 0) { 653 xprt->tcp_copied += r; 654 xprt->tcp_offset += r; 655 } 656 if (r != len) { 657 /* Error when copying to the receive buffer, 658 * usually because we weren't able to allocate 659 * additional buffer pages. All we can do now 660 * is turn off XPRT_COPY_DATA, so the request 661 * will not receive any additional updates, 662 * and time out. 663 * Any remaining data from this record will 664 * be discarded. 665 */ 666 xprt->tcp_flags &= ~XPRT_COPY_DATA; 667 dprintk("RPC: XID %08x truncated request\n", 668 ntohl(xprt->tcp_xid)); 669 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n", 670 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen); 671 goto out; 672 } 673 674 dprintk("RPC: XID %08x read %Zd bytes\n", 675 ntohl(xprt->tcp_xid), r); 676 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n", 677 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen); 678 679 if (xprt->tcp_copied == req->rq_private_buf.buflen) 680 xprt->tcp_flags &= ~XPRT_COPY_DATA; 681 else if (xprt->tcp_offset == xprt->tcp_reclen) { 682 if (xprt->tcp_flags & XPRT_LAST_FRAG) 683 xprt->tcp_flags &= ~XPRT_COPY_DATA; 684 } 685 686 out: 687 if (!(xprt->tcp_flags & XPRT_COPY_DATA)) 688 xprt_complete_rqst(req->rq_task, xprt->tcp_copied); 689 spin_unlock(&xprt->transport_lock); 690 xs_tcp_check_recm(xprt); 691 } 692 693 static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc) 694 { 695 size_t len; 696 697 len = xprt->tcp_reclen - xprt->tcp_offset; 698 if (len > desc->count) 699 len = desc->count; 700 desc->count -= len; 701 desc->offset += len; 702 xprt->tcp_offset += len; 703 dprintk("RPC: discarded %Zu bytes\n", len); 704 xs_tcp_check_recm(xprt); 705 } 706 707 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len) 708 { 709 struct rpc_xprt *xprt = rd_desc->arg.data; 710 skb_reader_t desc = { 711 .skb = skb, 712 .offset = offset, 713 .count = len, 714 .csum = 0 715 }; 716 717 dprintk("RPC: xs_tcp_data_recv started\n"); 718 do { 719 /* Read in a new fragment marker if necessary */ 720 /* Can we ever really expect to get completely empty fragments? */ 721 if (xprt->tcp_flags & XPRT_COPY_RECM) { 722 xs_tcp_read_fraghdr(xprt, &desc); 723 continue; 724 } 725 /* Read in the xid if necessary */ 726 if (xprt->tcp_flags & XPRT_COPY_XID) { 727 xs_tcp_read_xid(xprt, &desc); 728 continue; 729 } 730 /* Read in the request data */ 731 if (xprt->tcp_flags & XPRT_COPY_DATA) { 732 xs_tcp_read_request(xprt, &desc); 733 continue; 734 } 735 /* Skip over any trailing bytes on short reads */ 736 xs_tcp_read_discard(xprt, &desc); 737 } while (desc.count); 738 dprintk("RPC: xs_tcp_data_recv done\n"); 739 return len - desc.count; 740 } 741 742 /** 743 * xs_tcp_data_ready - "data ready" callback for TCP sockets 744 * @sk: socket with data to read 745 * @bytes: how much data to read 746 * 747 */ 748 static void xs_tcp_data_ready(struct sock *sk, int bytes) 749 { 750 struct rpc_xprt *xprt; 751 read_descriptor_t rd_desc; 752 753 read_lock(&sk->sk_callback_lock); 754 dprintk("RPC: xs_tcp_data_ready...\n"); 755 if (!(xprt = xprt_from_sock(sk))) 756 goto out; 757 if (xprt->shutdown) 758 goto out; 759 760 /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */ 761 rd_desc.arg.data = xprt; 762 rd_desc.count = 65536; 763 tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv); 764 out: 765 read_unlock(&sk->sk_callback_lock); 766 } 767 768 /** 769 * xs_tcp_state_change - callback to handle TCP socket state changes 770 * @sk: socket whose state has changed 771 * 772 */ 773 static void xs_tcp_state_change(struct sock *sk) 774 { 775 struct rpc_xprt *xprt; 776 777 read_lock(&sk->sk_callback_lock); 778 if (!(xprt = xprt_from_sock(sk))) 779 goto out; 780 dprintk("RPC: xs_tcp_state_change client %p...\n", xprt); 781 dprintk("RPC: state %x conn %d dead %d zapped %d\n", 782 sk->sk_state, xprt_connected(xprt), 783 sock_flag(sk, SOCK_DEAD), 784 sock_flag(sk, SOCK_ZAPPED)); 785 786 switch (sk->sk_state) { 787 case TCP_ESTABLISHED: 788 spin_lock_bh(&xprt->transport_lock); 789 if (!xprt_test_and_set_connected(xprt)) { 790 /* Reset TCP record info */ 791 xprt->tcp_offset = 0; 792 xprt->tcp_reclen = 0; 793 xprt->tcp_copied = 0; 794 xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID; 795 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO; 796 xprt_wake_pending_tasks(xprt, 0); 797 } 798 spin_unlock_bh(&xprt->transport_lock); 799 break; 800 case TCP_SYN_SENT: 801 case TCP_SYN_RECV: 802 break; 803 default: 804 xprt_disconnect(xprt); 805 break; 806 } 807 out: 808 read_unlock(&sk->sk_callback_lock); 809 } 810 811 /** 812 * xs_udp_write_space - callback invoked when socket buffer space 813 * becomes available 814 * @sk: socket whose state has changed 815 * 816 * Called when more output buffer space is available for this socket. 817 * We try not to wake our writers until they can make "significant" 818 * progress, otherwise we'll waste resources thrashing kernel_sendmsg 819 * with a bunch of small requests. 820 */ 821 static void xs_udp_write_space(struct sock *sk) 822 { 823 read_lock(&sk->sk_callback_lock); 824 825 /* from net/core/sock.c:sock_def_write_space */ 826 if (sock_writeable(sk)) { 827 struct socket *sock; 828 struct rpc_xprt *xprt; 829 830 if (unlikely(!(sock = sk->sk_socket))) 831 goto out; 832 if (unlikely(!(xprt = xprt_from_sock(sk)))) 833 goto out; 834 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags))) 835 goto out; 836 837 xprt_write_space(xprt); 838 } 839 840 out: 841 read_unlock(&sk->sk_callback_lock); 842 } 843 844 /** 845 * xs_tcp_write_space - callback invoked when socket buffer space 846 * becomes available 847 * @sk: socket whose state has changed 848 * 849 * Called when more output buffer space is available for this socket. 850 * We try not to wake our writers until they can make "significant" 851 * progress, otherwise we'll waste resources thrashing kernel_sendmsg 852 * with a bunch of small requests. 853 */ 854 static void xs_tcp_write_space(struct sock *sk) 855 { 856 read_lock(&sk->sk_callback_lock); 857 858 /* from net/core/stream.c:sk_stream_write_space */ 859 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 860 struct socket *sock; 861 struct rpc_xprt *xprt; 862 863 if (unlikely(!(sock = sk->sk_socket))) 864 goto out; 865 if (unlikely(!(xprt = xprt_from_sock(sk)))) 866 goto out; 867 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags))) 868 goto out; 869 870 xprt_write_space(xprt); 871 } 872 873 out: 874 read_unlock(&sk->sk_callback_lock); 875 } 876 877 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt) 878 { 879 struct sock *sk = xprt->inet; 880 881 if (xprt->rcvsize) { 882 sk->sk_userlocks |= SOCK_RCVBUF_LOCK; 883 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs * 2; 884 } 885 if (xprt->sndsize) { 886 sk->sk_userlocks |= SOCK_SNDBUF_LOCK; 887 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2; 888 sk->sk_write_space(sk); 889 } 890 } 891 892 /** 893 * xs_udp_set_buffer_size - set send and receive limits 894 * @xprt: generic transport 895 * @sndsize: requested size of send buffer, in bytes 896 * @rcvsize: requested size of receive buffer, in bytes 897 * 898 * Set socket send and receive buffer size limits. 899 */ 900 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize) 901 { 902 xprt->sndsize = 0; 903 if (sndsize) 904 xprt->sndsize = sndsize + 1024; 905 xprt->rcvsize = 0; 906 if (rcvsize) 907 xprt->rcvsize = rcvsize + 1024; 908 909 xs_udp_do_set_buffer_size(xprt); 910 } 911 912 /** 913 * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport 914 * @task: task that timed out 915 * 916 * Adjust the congestion window after a retransmit timeout has occurred. 917 */ 918 static void xs_udp_timer(struct rpc_task *task) 919 { 920 xprt_adjust_cwnd(task, -ETIMEDOUT); 921 } 922 923 static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock) 924 { 925 struct sockaddr_in myaddr = { 926 .sin_family = AF_INET, 927 }; 928 int err; 929 unsigned short port = xprt->port; 930 931 do { 932 myaddr.sin_port = htons(port); 933 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr, 934 sizeof(myaddr)); 935 if (err == 0) { 936 xprt->port = port; 937 dprintk("RPC: xs_bindresvport bound to port %u\n", 938 port); 939 return 0; 940 } 941 if (port <= xprt_min_resvport) 942 port = xprt_max_resvport; 943 else 944 port--; 945 } while (err == -EADDRINUSE && port != xprt->port); 946 947 dprintk("RPC: can't bind to reserved port (%d).\n", -err); 948 return err; 949 } 950 951 /** 952 * xs_udp_connect_worker - set up a UDP socket 953 * @args: RPC transport to connect 954 * 955 * Invoked by a work queue tasklet. 956 */ 957 static void xs_udp_connect_worker(void *args) 958 { 959 struct rpc_xprt *xprt = (struct rpc_xprt *) args; 960 struct socket *sock = xprt->sock; 961 int err, status = -EIO; 962 963 if (xprt->shutdown || xprt->addr.sin_port == 0) 964 goto out; 965 966 dprintk("RPC: xs_udp_connect_worker for xprt %p\n", xprt); 967 968 /* Start by resetting any existing state */ 969 xs_close(xprt); 970 971 if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) { 972 dprintk("RPC: can't create UDP transport socket (%d).\n", -err); 973 goto out; 974 } 975 976 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) { 977 sock_release(sock); 978 goto out; 979 } 980 981 if (!xprt->inet) { 982 struct sock *sk = sock->sk; 983 984 write_lock_bh(&sk->sk_callback_lock); 985 986 sk->sk_user_data = xprt; 987 xprt->old_data_ready = sk->sk_data_ready; 988 xprt->old_state_change = sk->sk_state_change; 989 xprt->old_write_space = sk->sk_write_space; 990 sk->sk_data_ready = xs_udp_data_ready; 991 sk->sk_write_space = xs_udp_write_space; 992 sk->sk_no_check = UDP_CSUM_NORCV; 993 994 xprt_set_connected(xprt); 995 996 /* Reset to new socket */ 997 xprt->sock = sock; 998 xprt->inet = sk; 999 1000 write_unlock_bh(&sk->sk_callback_lock); 1001 } 1002 xs_udp_do_set_buffer_size(xprt); 1003 status = 0; 1004 out: 1005 xprt_wake_pending_tasks(xprt, status); 1006 xprt_clear_connecting(xprt); 1007 } 1008 1009 /* 1010 * We need to preserve the port number so the reply cache on the server can 1011 * find our cached RPC replies when we get around to reconnecting. 1012 */ 1013 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt) 1014 { 1015 int result; 1016 struct socket *sock = xprt->sock; 1017 struct sockaddr any; 1018 1019 dprintk("RPC: disconnecting xprt %p to reuse port\n", xprt); 1020 1021 /* 1022 * Disconnect the transport socket by doing a connect operation 1023 * with AF_UNSPEC. This should return immediately... 1024 */ 1025 memset(&any, 0, sizeof(any)); 1026 any.sa_family = AF_UNSPEC; 1027 result = sock->ops->connect(sock, &any, sizeof(any), 0); 1028 if (result) 1029 dprintk("RPC: AF_UNSPEC connect return code %d\n", 1030 result); 1031 } 1032 1033 /** 1034 * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint 1035 * @args: RPC transport to connect 1036 * 1037 * Invoked by a work queue tasklet. 1038 */ 1039 static void xs_tcp_connect_worker(void *args) 1040 { 1041 struct rpc_xprt *xprt = (struct rpc_xprt *)args; 1042 struct socket *sock = xprt->sock; 1043 int err, status = -EIO; 1044 1045 if (xprt->shutdown || xprt->addr.sin_port == 0) 1046 goto out; 1047 1048 dprintk("RPC: xs_tcp_connect_worker for xprt %p\n", xprt); 1049 1050 if (!xprt->sock) { 1051 /* start from scratch */ 1052 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) { 1053 dprintk("RPC: can't create TCP transport socket (%d).\n", -err); 1054 goto out; 1055 } 1056 1057 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) { 1058 sock_release(sock); 1059 goto out; 1060 } 1061 } else 1062 /* "close" the socket, preserving the local port */ 1063 xs_tcp_reuse_connection(xprt); 1064 1065 if (!xprt->inet) { 1066 struct sock *sk = sock->sk; 1067 1068 write_lock_bh(&sk->sk_callback_lock); 1069 1070 sk->sk_user_data = xprt; 1071 xprt->old_data_ready = sk->sk_data_ready; 1072 xprt->old_state_change = sk->sk_state_change; 1073 xprt->old_write_space = sk->sk_write_space; 1074 sk->sk_data_ready = xs_tcp_data_ready; 1075 sk->sk_state_change = xs_tcp_state_change; 1076 sk->sk_write_space = xs_tcp_write_space; 1077 1078 /* socket options */ 1079 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 1080 sock_reset_flag(sk, SOCK_LINGER); 1081 tcp_sk(sk)->linger2 = 0; 1082 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF; 1083 1084 xprt_clear_connected(xprt); 1085 1086 /* Reset to new socket */ 1087 xprt->sock = sock; 1088 xprt->inet = sk; 1089 1090 write_unlock_bh(&sk->sk_callback_lock); 1091 } 1092 1093 /* Tell the socket layer to start connecting... */ 1094 status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr, 1095 sizeof(xprt->addr), O_NONBLOCK); 1096 dprintk("RPC: %p connect status %d connected %d sock state %d\n", 1097 xprt, -status, xprt_connected(xprt), sock->sk->sk_state); 1098 if (status < 0) { 1099 switch (status) { 1100 case -EINPROGRESS: 1101 case -EALREADY: 1102 goto out_clear; 1103 case -ECONNREFUSED: 1104 case -ECONNRESET: 1105 /* retry with existing socket, after a delay */ 1106 break; 1107 default: 1108 /* get rid of existing socket, and retry */ 1109 xs_close(xprt); 1110 break; 1111 } 1112 } 1113 out: 1114 xprt_wake_pending_tasks(xprt, status); 1115 out_clear: 1116 xprt_clear_connecting(xprt); 1117 } 1118 1119 /** 1120 * xs_connect - connect a socket to a remote endpoint 1121 * @task: address of RPC task that manages state of connect request 1122 * 1123 * TCP: If the remote end dropped the connection, delay reconnecting. 1124 * 1125 * UDP socket connects are synchronous, but we use a work queue anyway 1126 * to guarantee that even unprivileged user processes can set up a 1127 * socket on a privileged port. 1128 * 1129 * If a UDP socket connect fails, the delay behavior here prevents 1130 * retry floods (hard mounts). 1131 */ 1132 static void xs_connect(struct rpc_task *task) 1133 { 1134 struct rpc_xprt *xprt = task->tk_xprt; 1135 1136 if (xprt_test_and_set_connecting(xprt)) 1137 return; 1138 1139 if (xprt->sock != NULL) { 1140 dprintk("RPC: xs_connect delayed xprt %p for %lu seconds\n", 1141 xprt, xprt->reestablish_timeout / HZ); 1142 schedule_delayed_work(&xprt->connect_worker, 1143 xprt->reestablish_timeout); 1144 xprt->reestablish_timeout <<= 1; 1145 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO) 1146 xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO; 1147 } else { 1148 dprintk("RPC: xs_connect scheduled xprt %p\n", xprt); 1149 schedule_work(&xprt->connect_worker); 1150 1151 /* flush_scheduled_work can sleep... */ 1152 if (!RPC_IS_ASYNC(task)) 1153 flush_scheduled_work(); 1154 } 1155 } 1156 1157 static struct rpc_xprt_ops xs_udp_ops = { 1158 .set_buffer_size = xs_udp_set_buffer_size, 1159 .reserve_xprt = xprt_reserve_xprt_cong, 1160 .release_xprt = xprt_release_xprt_cong, 1161 .connect = xs_connect, 1162 .send_request = xs_udp_send_request, 1163 .set_retrans_timeout = xprt_set_retrans_timeout_rtt, 1164 .timer = xs_udp_timer, 1165 .release_request = xprt_release_rqst_cong, 1166 .close = xs_close, 1167 .destroy = xs_destroy, 1168 }; 1169 1170 static struct rpc_xprt_ops xs_tcp_ops = { 1171 .reserve_xprt = xprt_reserve_xprt, 1172 .release_xprt = xprt_release_xprt, 1173 .connect = xs_connect, 1174 .send_request = xs_tcp_send_request, 1175 .set_retrans_timeout = xprt_set_retrans_timeout_def, 1176 .close = xs_close, 1177 .destroy = xs_destroy, 1178 }; 1179 1180 /** 1181 * xs_setup_udp - Set up transport to use a UDP socket 1182 * @xprt: transport to set up 1183 * @to: timeout parameters 1184 * 1185 */ 1186 int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to) 1187 { 1188 size_t slot_table_size; 1189 1190 dprintk("RPC: setting up udp-ipv4 transport...\n"); 1191 1192 xprt->max_reqs = xprt_udp_slot_table_entries; 1193 slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]); 1194 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL); 1195 if (xprt->slot == NULL) 1196 return -ENOMEM; 1197 memset(xprt->slot, 0, slot_table_size); 1198 1199 xprt->prot = IPPROTO_UDP; 1200 xprt->port = xprt_max_resvport; 1201 xprt->tsh_size = 0; 1202 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0; 1203 /* XXX: header size can vary due to auth type, IPv6, etc. */ 1204 xprt->max_payload = (1U << 16) - (MAX_HEADER << 3); 1205 1206 INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt); 1207 xprt->bind_timeout = XS_BIND_TO; 1208 xprt->connect_timeout = XS_UDP_CONN_TO; 1209 xprt->reestablish_timeout = XS_UDP_REEST_TO; 1210 xprt->idle_timeout = XS_IDLE_DISC_TO; 1211 1212 xprt->ops = &xs_udp_ops; 1213 1214 if (to) 1215 xprt->timeout = *to; 1216 else 1217 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ); 1218 1219 return 0; 1220 } 1221 1222 /** 1223 * xs_setup_tcp - Set up transport to use a TCP socket 1224 * @xprt: transport to set up 1225 * @to: timeout parameters 1226 * 1227 */ 1228 int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to) 1229 { 1230 size_t slot_table_size; 1231 1232 dprintk("RPC: setting up tcp-ipv4 transport...\n"); 1233 1234 xprt->max_reqs = xprt_tcp_slot_table_entries; 1235 slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]); 1236 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL); 1237 if (xprt->slot == NULL) 1238 return -ENOMEM; 1239 memset(xprt->slot, 0, slot_table_size); 1240 1241 xprt->prot = IPPROTO_TCP; 1242 xprt->port = xprt_max_resvport; 1243 xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32); 1244 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0; 1245 xprt->max_payload = RPC_MAX_FRAGMENT_SIZE; 1246 1247 INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt); 1248 xprt->bind_timeout = XS_BIND_TO; 1249 xprt->connect_timeout = XS_TCP_CONN_TO; 1250 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO; 1251 xprt->idle_timeout = XS_IDLE_DISC_TO; 1252 1253 xprt->ops = &xs_tcp_ops; 1254 1255 if (to) 1256 xprt->timeout = *to; 1257 else 1258 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ); 1259 1260 return 0; 1261 } 1262