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/sunrpc/sched.h> 32 #include <linux/file.h> 33 34 #include <net/sock.h> 35 #include <net/checksum.h> 36 #include <net/udp.h> 37 #include <net/tcp.h> 38 39 /* 40 * xprtsock tunables 41 */ 42 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE; 43 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE; 44 45 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT; 46 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT; 47 48 /* 49 * How many times to try sending a request on a socket before waiting 50 * for the socket buffer to clear. 51 */ 52 #define XS_SENDMSG_RETRY (10U) 53 54 /* 55 * Time out for an RPC UDP socket connect. UDP socket connects are 56 * synchronous, but we set a timeout anyway in case of resource 57 * exhaustion on the local host. 58 */ 59 #define XS_UDP_CONN_TO (5U * HZ) 60 61 /* 62 * Wait duration for an RPC TCP connection to be established. Solaris 63 * NFS over TCP uses 60 seconds, for example, which is in line with how 64 * long a server takes to reboot. 65 */ 66 #define XS_TCP_CONN_TO (60U * HZ) 67 68 /* 69 * Wait duration for a reply from the RPC portmapper. 70 */ 71 #define XS_BIND_TO (60U * HZ) 72 73 /* 74 * Delay if a UDP socket connect error occurs. This is most likely some 75 * kind of resource problem on the local host. 76 */ 77 #define XS_UDP_REEST_TO (2U * HZ) 78 79 /* 80 * The reestablish timeout allows clients to delay for a bit before attempting 81 * to reconnect to a server that just dropped our connection. 82 * 83 * We implement an exponential backoff when trying to reestablish a TCP 84 * transport connection with the server. Some servers like to drop a TCP 85 * connection when they are overworked, so we start with a short timeout and 86 * increase over time if the server is down or not responding. 87 */ 88 #define XS_TCP_INIT_REEST_TO (3U * HZ) 89 #define XS_TCP_MAX_REEST_TO (5U * 60 * HZ) 90 91 /* 92 * TCP idle timeout; client drops the transport socket if it is idle 93 * for this long. Note that we also timeout UDP sockets to prevent 94 * holding port numbers when there is no RPC traffic. 95 */ 96 #define XS_IDLE_DISC_TO (5U * 60 * HZ) 97 98 #ifdef RPC_DEBUG 99 # undef RPC_DEBUG_DATA 100 # define RPCDBG_FACILITY RPCDBG_TRANS 101 #endif 102 103 #ifdef RPC_DEBUG_DATA 104 static void xs_pktdump(char *msg, u32 *packet, unsigned int count) 105 { 106 u8 *buf = (u8 *) packet; 107 int j; 108 109 dprintk("RPC: %s\n", msg); 110 for (j = 0; j < count && j < 128; j += 4) { 111 if (!(j & 31)) { 112 if (j) 113 dprintk("\n"); 114 dprintk("0x%04x ", j); 115 } 116 dprintk("%02x%02x%02x%02x ", 117 buf[j], buf[j+1], buf[j+2], buf[j+3]); 118 } 119 dprintk("\n"); 120 } 121 #else 122 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count) 123 { 124 /* NOP */ 125 } 126 #endif 127 128 #define XS_SENDMSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL) 129 130 static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len) 131 { 132 struct kvec iov = { 133 .iov_base = xdr->head[0].iov_base + base, 134 .iov_len = len - base, 135 }; 136 struct msghdr msg = { 137 .msg_name = addr, 138 .msg_namelen = addrlen, 139 .msg_flags = XS_SENDMSG_FLAGS, 140 }; 141 142 if (xdr->len > len) 143 msg.msg_flags |= MSG_MORE; 144 145 if (likely(iov.iov_len)) 146 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len); 147 return kernel_sendmsg(sock, &msg, NULL, 0, 0); 148 } 149 150 static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len) 151 { 152 struct kvec iov = { 153 .iov_base = xdr->tail[0].iov_base + base, 154 .iov_len = len - base, 155 }; 156 struct msghdr msg = { 157 .msg_flags = XS_SENDMSG_FLAGS, 158 }; 159 160 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len); 161 } 162 163 /** 164 * xs_sendpages - write pages directly to a socket 165 * @sock: socket to send on 166 * @addr: UDP only -- address of destination 167 * @addrlen: UDP only -- length of destination address 168 * @xdr: buffer containing this request 169 * @base: starting position in the buffer 170 * 171 */ 172 static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base) 173 { 174 struct page **ppage = xdr->pages; 175 unsigned int len, pglen = xdr->page_len; 176 int err, ret = 0; 177 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int); 178 179 if (unlikely(!sock)) 180 return -ENOTCONN; 181 182 clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags); 183 184 len = xdr->head[0].iov_len; 185 if (base < len || (addr != NULL && base == 0)) { 186 err = xs_send_head(sock, addr, addrlen, xdr, base, len); 187 if (ret == 0) 188 ret = err; 189 else if (err > 0) 190 ret += err; 191 if (err != (len - base)) 192 goto out; 193 base = 0; 194 } else 195 base -= len; 196 197 if (unlikely(pglen == 0)) 198 goto copy_tail; 199 if (unlikely(base >= pglen)) { 200 base -= pglen; 201 goto copy_tail; 202 } 203 if (base || xdr->page_base) { 204 pglen -= base; 205 base += xdr->page_base; 206 ppage += base >> PAGE_CACHE_SHIFT; 207 base &= ~PAGE_CACHE_MASK; 208 } 209 210 sendpage = sock->ops->sendpage ? : sock_no_sendpage; 211 do { 212 int flags = XS_SENDMSG_FLAGS; 213 214 len = PAGE_CACHE_SIZE; 215 if (base) 216 len -= base; 217 if (pglen < len) 218 len = pglen; 219 220 if (pglen != len || xdr->tail[0].iov_len != 0) 221 flags |= MSG_MORE; 222 223 /* Hmm... We might be dealing with highmem pages */ 224 if (PageHighMem(*ppage)) 225 sendpage = sock_no_sendpage; 226 err = sendpage(sock, *ppage, base, len, flags); 227 if (ret == 0) 228 ret = err; 229 else if (err > 0) 230 ret += err; 231 if (err != len) 232 goto out; 233 base = 0; 234 ppage++; 235 } while ((pglen -= len) != 0); 236 copy_tail: 237 len = xdr->tail[0].iov_len; 238 if (base < len) { 239 err = xs_send_tail(sock, xdr, base, len); 240 if (ret == 0) 241 ret = err; 242 else if (err > 0) 243 ret += err; 244 } 245 out: 246 return ret; 247 } 248 249 /** 250 * xs_nospace - place task on wait queue if transmit was incomplete 251 * @task: task to put to sleep 252 * 253 */ 254 static void xs_nospace(struct rpc_task *task) 255 { 256 struct rpc_rqst *req = task->tk_rqstp; 257 struct rpc_xprt *xprt = req->rq_xprt; 258 259 dprintk("RPC: %4d xmit incomplete (%u left of %u)\n", 260 task->tk_pid, req->rq_slen - req->rq_bytes_sent, 261 req->rq_slen); 262 263 if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) { 264 /* Protect against races with write_space */ 265 spin_lock_bh(&xprt->transport_lock); 266 267 /* Don't race with disconnect */ 268 if (!xprt_connected(xprt)) 269 task->tk_status = -ENOTCONN; 270 else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags)) 271 xprt_wait_for_buffer_space(task); 272 273 spin_unlock_bh(&xprt->transport_lock); 274 } else 275 /* Keep holding the socket if it is blocked */ 276 rpc_delay(task, HZ>>4); 277 } 278 279 /** 280 * xs_udp_send_request - write an RPC request to a UDP socket 281 * @task: address of RPC task that manages the state of an RPC request 282 * 283 * Return values: 284 * 0: The request has been sent 285 * EAGAIN: The socket was blocked, please call again later to 286 * complete the request 287 * ENOTCONN: Caller needs to invoke connect logic then call again 288 * other: Some other error occured, the request was not sent 289 */ 290 static int xs_udp_send_request(struct rpc_task *task) 291 { 292 struct rpc_rqst *req = task->tk_rqstp; 293 struct rpc_xprt *xprt = req->rq_xprt; 294 struct xdr_buf *xdr = &req->rq_snd_buf; 295 int status; 296 297 xs_pktdump("packet data:", 298 req->rq_svec->iov_base, 299 req->rq_svec->iov_len); 300 301 req->rq_xtime = jiffies; 302 status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr, 303 sizeof(xprt->addr), xdr, req->rq_bytes_sent); 304 305 dprintk("RPC: xs_udp_send_request(%u) = %d\n", 306 xdr->len - req->rq_bytes_sent, status); 307 308 if (likely(status >= (int) req->rq_slen)) 309 return 0; 310 311 /* Still some bytes left; set up for a retry later. */ 312 if (status > 0) 313 status = -EAGAIN; 314 315 switch (status) { 316 case -ENETUNREACH: 317 case -EPIPE: 318 case -ECONNREFUSED: 319 /* When the server has died, an ICMP port unreachable message 320 * prompts ECONNREFUSED. */ 321 break; 322 case -EAGAIN: 323 xs_nospace(task); 324 break; 325 default: 326 dprintk("RPC: sendmsg returned unrecognized error %d\n", 327 -status); 328 break; 329 } 330 331 return status; 332 } 333 334 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf) 335 { 336 u32 reclen = buf->len - sizeof(rpc_fraghdr); 337 rpc_fraghdr *base = buf->head[0].iov_base; 338 *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen); 339 } 340 341 /** 342 * xs_tcp_send_request - write an RPC request to a TCP socket 343 * @task: address of RPC task that manages the state of an RPC request 344 * 345 * Return values: 346 * 0: The request has been sent 347 * EAGAIN: The socket was blocked, please call again later to 348 * complete the request 349 * ENOTCONN: Caller needs to invoke connect logic then call again 350 * other: Some other error occured, the request was not sent 351 * 352 * XXX: In the case of soft timeouts, should we eventually give up 353 * if sendmsg is not able to make progress? 354 */ 355 static int xs_tcp_send_request(struct rpc_task *task) 356 { 357 struct rpc_rqst *req = task->tk_rqstp; 358 struct rpc_xprt *xprt = req->rq_xprt; 359 struct xdr_buf *xdr = &req->rq_snd_buf; 360 int status, retry = 0; 361 362 xs_encode_tcp_record_marker(&req->rq_snd_buf); 363 364 xs_pktdump("packet data:", 365 req->rq_svec->iov_base, 366 req->rq_svec->iov_len); 367 368 /* Continue transmitting the packet/record. We must be careful 369 * to cope with writespace callbacks arriving _after_ we have 370 * called sendmsg(). */ 371 while (1) { 372 req->rq_xtime = jiffies; 373 status = xs_sendpages(xprt->sock, NULL, 0, xdr, 374 req->rq_bytes_sent); 375 376 dprintk("RPC: xs_tcp_send_request(%u) = %d\n", 377 xdr->len - req->rq_bytes_sent, status); 378 379 if (unlikely(status < 0)) 380 break; 381 382 /* If we've sent the entire packet, immediately 383 * reset the count of bytes sent. */ 384 req->rq_bytes_sent += status; 385 if (likely(req->rq_bytes_sent >= req->rq_slen)) { 386 req->rq_bytes_sent = 0; 387 return 0; 388 } 389 390 status = -EAGAIN; 391 if (retry++ > XS_SENDMSG_RETRY) 392 break; 393 } 394 395 switch (status) { 396 case -EAGAIN: 397 xs_nospace(task); 398 break; 399 case -ECONNREFUSED: 400 case -ECONNRESET: 401 case -ENOTCONN: 402 case -EPIPE: 403 status = -ENOTCONN; 404 break; 405 default: 406 dprintk("RPC: sendmsg returned unrecognized error %d\n", 407 -status); 408 xprt_disconnect(xprt); 409 break; 410 } 411 412 return status; 413 } 414 415 /** 416 * xs_close - close a socket 417 * @xprt: transport 418 * 419 * This is used when all requests are complete; ie, no DRC state remains 420 * on the server we want to save. 421 */ 422 static void xs_close(struct rpc_xprt *xprt) 423 { 424 struct socket *sock = xprt->sock; 425 struct sock *sk = xprt->inet; 426 427 if (!sk) 428 goto clear_close_wait; 429 430 dprintk("RPC: xs_close xprt %p\n", xprt); 431 432 write_lock_bh(&sk->sk_callback_lock); 433 xprt->inet = NULL; 434 xprt->sock = NULL; 435 436 sk->sk_user_data = NULL; 437 sk->sk_data_ready = xprt->old_data_ready; 438 sk->sk_state_change = xprt->old_state_change; 439 sk->sk_write_space = xprt->old_write_space; 440 write_unlock_bh(&sk->sk_callback_lock); 441 442 sk->sk_no_check = 0; 443 444 sock_release(sock); 445 clear_close_wait: 446 smp_mb__before_clear_bit(); 447 clear_bit(XPRT_CLOSE_WAIT, &xprt->state); 448 smp_mb__after_clear_bit(); 449 } 450 451 /** 452 * xs_destroy - prepare to shutdown a transport 453 * @xprt: doomed transport 454 * 455 */ 456 static void xs_destroy(struct rpc_xprt *xprt) 457 { 458 dprintk("RPC: xs_destroy xprt %p\n", xprt); 459 460 cancel_delayed_work(&xprt->connect_worker); 461 flush_scheduled_work(); 462 463 xprt_disconnect(xprt); 464 xs_close(xprt); 465 kfree(xprt->slot); 466 } 467 468 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk) 469 { 470 return (struct rpc_xprt *) sk->sk_user_data; 471 } 472 473 /** 474 * xs_udp_data_ready - "data ready" callback for UDP sockets 475 * @sk: socket with data to read 476 * @len: how much data to read 477 * 478 */ 479 static void xs_udp_data_ready(struct sock *sk, int len) 480 { 481 struct rpc_task *task; 482 struct rpc_xprt *xprt; 483 struct rpc_rqst *rovr; 484 struct sk_buff *skb; 485 int err, repsize, copied; 486 u32 _xid, *xp; 487 488 read_lock(&sk->sk_callback_lock); 489 dprintk("RPC: xs_udp_data_ready...\n"); 490 if (!(xprt = xprt_from_sock(sk))) 491 goto out; 492 493 if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL) 494 goto out; 495 496 if (xprt->shutdown) 497 goto dropit; 498 499 repsize = skb->len - sizeof(struct udphdr); 500 if (repsize < 4) { 501 dprintk("RPC: impossible RPC reply size %d!\n", repsize); 502 goto dropit; 503 } 504 505 /* Copy the XID from the skb... */ 506 xp = skb_header_pointer(skb, sizeof(struct udphdr), 507 sizeof(_xid), &_xid); 508 if (xp == NULL) 509 goto dropit; 510 511 /* Look up and lock the request corresponding to the given XID */ 512 spin_lock(&xprt->transport_lock); 513 rovr = xprt_lookup_rqst(xprt, *xp); 514 if (!rovr) 515 goto out_unlock; 516 task = rovr->rq_task; 517 518 if ((copied = rovr->rq_private_buf.buflen) > repsize) 519 copied = repsize; 520 521 /* Suck it into the iovec, verify checksum if not done by hw. */ 522 if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) 523 goto out_unlock; 524 525 /* Something worked... */ 526 dst_confirm(skb->dst); 527 528 xprt_adjust_cwnd(task, copied); 529 xprt_update_rtt(task); 530 xprt_complete_rqst(task, copied); 531 532 out_unlock: 533 spin_unlock(&xprt->transport_lock); 534 dropit: 535 skb_free_datagram(sk, skb); 536 out: 537 read_unlock(&sk->sk_callback_lock); 538 } 539 540 static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len) 541 { 542 if (len > desc->count) 543 len = desc->count; 544 if (skb_copy_bits(desc->skb, desc->offset, p, len)) { 545 dprintk("RPC: failed to copy %zu bytes from skb. %zu bytes remain\n", 546 len, desc->count); 547 return 0; 548 } 549 desc->offset += len; 550 desc->count -= len; 551 dprintk("RPC: copied %zu bytes from skb. %zu bytes remain\n", 552 len, desc->count); 553 return len; 554 } 555 556 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc) 557 { 558 size_t len, used; 559 char *p; 560 561 p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset; 562 len = sizeof(xprt->tcp_recm) - xprt->tcp_offset; 563 used = xs_tcp_copy_data(desc, p, len); 564 xprt->tcp_offset += used; 565 if (used != len) 566 return; 567 568 xprt->tcp_reclen = ntohl(xprt->tcp_recm); 569 if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT) 570 xprt->tcp_flags |= XPRT_LAST_FRAG; 571 else 572 xprt->tcp_flags &= ~XPRT_LAST_FRAG; 573 xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK; 574 575 xprt->tcp_flags &= ~XPRT_COPY_RECM; 576 xprt->tcp_offset = 0; 577 578 /* Sanity check of the record length */ 579 if (unlikely(xprt->tcp_reclen < 4)) { 580 dprintk("RPC: invalid TCP record fragment length\n"); 581 xprt_disconnect(xprt); 582 return; 583 } 584 dprintk("RPC: reading TCP record fragment of length %d\n", 585 xprt->tcp_reclen); 586 } 587 588 static void xs_tcp_check_recm(struct rpc_xprt *xprt) 589 { 590 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n", 591 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags); 592 if (xprt->tcp_offset == xprt->tcp_reclen) { 593 xprt->tcp_flags |= XPRT_COPY_RECM; 594 xprt->tcp_offset = 0; 595 if (xprt->tcp_flags & XPRT_LAST_FRAG) { 596 xprt->tcp_flags &= ~XPRT_COPY_DATA; 597 xprt->tcp_flags |= XPRT_COPY_XID; 598 xprt->tcp_copied = 0; 599 } 600 } 601 } 602 603 static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc) 604 { 605 size_t len, used; 606 char *p; 607 608 len = sizeof(xprt->tcp_xid) - xprt->tcp_offset; 609 dprintk("RPC: reading XID (%Zu bytes)\n", len); 610 p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset; 611 used = xs_tcp_copy_data(desc, p, len); 612 xprt->tcp_offset += used; 613 if (used != len) 614 return; 615 xprt->tcp_flags &= ~XPRT_COPY_XID; 616 xprt->tcp_flags |= XPRT_COPY_DATA; 617 xprt->tcp_copied = 4; 618 dprintk("RPC: reading reply for XID %08x\n", 619 ntohl(xprt->tcp_xid)); 620 xs_tcp_check_recm(xprt); 621 } 622 623 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc) 624 { 625 struct rpc_rqst *req; 626 struct xdr_buf *rcvbuf; 627 size_t len; 628 ssize_t r; 629 630 /* Find and lock the request corresponding to this xid */ 631 spin_lock(&xprt->transport_lock); 632 req = xprt_lookup_rqst(xprt, xprt->tcp_xid); 633 if (!req) { 634 xprt->tcp_flags &= ~XPRT_COPY_DATA; 635 dprintk("RPC: XID %08x request not found!\n", 636 ntohl(xprt->tcp_xid)); 637 spin_unlock(&xprt->transport_lock); 638 return; 639 } 640 641 rcvbuf = &req->rq_private_buf; 642 len = desc->count; 643 if (len > xprt->tcp_reclen - xprt->tcp_offset) { 644 skb_reader_t my_desc; 645 646 len = xprt->tcp_reclen - xprt->tcp_offset; 647 memcpy(&my_desc, desc, sizeof(my_desc)); 648 my_desc.count = len; 649 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied, 650 &my_desc, xs_tcp_copy_data); 651 desc->count -= r; 652 desc->offset += r; 653 } else 654 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied, 655 desc, xs_tcp_copy_data); 656 657 if (r > 0) { 658 xprt->tcp_copied += r; 659 xprt->tcp_offset += r; 660 } 661 if (r != len) { 662 /* Error when copying to the receive buffer, 663 * usually because we weren't able to allocate 664 * additional buffer pages. All we can do now 665 * is turn off XPRT_COPY_DATA, so the request 666 * will not receive any additional updates, 667 * and time out. 668 * Any remaining data from this record will 669 * be discarded. 670 */ 671 xprt->tcp_flags &= ~XPRT_COPY_DATA; 672 dprintk("RPC: XID %08x truncated request\n", 673 ntohl(xprt->tcp_xid)); 674 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n", 675 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen); 676 goto out; 677 } 678 679 dprintk("RPC: XID %08x read %Zd bytes\n", 680 ntohl(xprt->tcp_xid), r); 681 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n", 682 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen); 683 684 if (xprt->tcp_copied == req->rq_private_buf.buflen) 685 xprt->tcp_flags &= ~XPRT_COPY_DATA; 686 else if (xprt->tcp_offset == xprt->tcp_reclen) { 687 if (xprt->tcp_flags & XPRT_LAST_FRAG) 688 xprt->tcp_flags &= ~XPRT_COPY_DATA; 689 } 690 691 out: 692 if (!(xprt->tcp_flags & XPRT_COPY_DATA)) 693 xprt_complete_rqst(req->rq_task, xprt->tcp_copied); 694 spin_unlock(&xprt->transport_lock); 695 xs_tcp_check_recm(xprt); 696 } 697 698 static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc) 699 { 700 size_t len; 701 702 len = xprt->tcp_reclen - xprt->tcp_offset; 703 if (len > desc->count) 704 len = desc->count; 705 desc->count -= len; 706 desc->offset += len; 707 xprt->tcp_offset += len; 708 dprintk("RPC: discarded %Zu bytes\n", len); 709 xs_tcp_check_recm(xprt); 710 } 711 712 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len) 713 { 714 struct rpc_xprt *xprt = rd_desc->arg.data; 715 skb_reader_t desc = { 716 .skb = skb, 717 .offset = offset, 718 .count = len, 719 .csum = 0 720 }; 721 722 dprintk("RPC: xs_tcp_data_recv started\n"); 723 do { 724 /* Read in a new fragment marker if necessary */ 725 /* Can we ever really expect to get completely empty fragments? */ 726 if (xprt->tcp_flags & XPRT_COPY_RECM) { 727 xs_tcp_read_fraghdr(xprt, &desc); 728 continue; 729 } 730 /* Read in the xid if necessary */ 731 if (xprt->tcp_flags & XPRT_COPY_XID) { 732 xs_tcp_read_xid(xprt, &desc); 733 continue; 734 } 735 /* Read in the request data */ 736 if (xprt->tcp_flags & XPRT_COPY_DATA) { 737 xs_tcp_read_request(xprt, &desc); 738 continue; 739 } 740 /* Skip over any trailing bytes on short reads */ 741 xs_tcp_read_discard(xprt, &desc); 742 } while (desc.count); 743 dprintk("RPC: xs_tcp_data_recv done\n"); 744 return len - desc.count; 745 } 746 747 /** 748 * xs_tcp_data_ready - "data ready" callback for TCP sockets 749 * @sk: socket with data to read 750 * @bytes: how much data to read 751 * 752 */ 753 static void xs_tcp_data_ready(struct sock *sk, int bytes) 754 { 755 struct rpc_xprt *xprt; 756 read_descriptor_t rd_desc; 757 758 read_lock(&sk->sk_callback_lock); 759 dprintk("RPC: xs_tcp_data_ready...\n"); 760 if (!(xprt = xprt_from_sock(sk))) 761 goto out; 762 if (xprt->shutdown) 763 goto out; 764 765 /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */ 766 rd_desc.arg.data = xprt; 767 rd_desc.count = 65536; 768 tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv); 769 out: 770 read_unlock(&sk->sk_callback_lock); 771 } 772 773 /** 774 * xs_tcp_state_change - callback to handle TCP socket state changes 775 * @sk: socket whose state has changed 776 * 777 */ 778 static void xs_tcp_state_change(struct sock *sk) 779 { 780 struct rpc_xprt *xprt; 781 782 read_lock(&sk->sk_callback_lock); 783 if (!(xprt = xprt_from_sock(sk))) 784 goto out; 785 dprintk("RPC: xs_tcp_state_change client %p...\n", xprt); 786 dprintk("RPC: state %x conn %d dead %d zapped %d\n", 787 sk->sk_state, xprt_connected(xprt), 788 sock_flag(sk, SOCK_DEAD), 789 sock_flag(sk, SOCK_ZAPPED)); 790 791 switch (sk->sk_state) { 792 case TCP_ESTABLISHED: 793 spin_lock_bh(&xprt->transport_lock); 794 if (!xprt_test_and_set_connected(xprt)) { 795 /* Reset TCP record info */ 796 xprt->tcp_offset = 0; 797 xprt->tcp_reclen = 0; 798 xprt->tcp_copied = 0; 799 xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID; 800 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO; 801 xprt_wake_pending_tasks(xprt, 0); 802 } 803 spin_unlock_bh(&xprt->transport_lock); 804 break; 805 case TCP_SYN_SENT: 806 case TCP_SYN_RECV: 807 break; 808 case TCP_CLOSE_WAIT: 809 /* Try to schedule an autoclose RPC calls */ 810 set_bit(XPRT_CLOSE_WAIT, &xprt->state); 811 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) 812 schedule_work(&xprt->task_cleanup); 813 default: 814 xprt_disconnect(xprt); 815 } 816 out: 817 read_unlock(&sk->sk_callback_lock); 818 } 819 820 /** 821 * xs_udp_write_space - callback invoked when socket buffer space 822 * becomes available 823 * @sk: socket whose state has changed 824 * 825 * Called when more output buffer space is available for this socket. 826 * We try not to wake our writers until they can make "significant" 827 * progress, otherwise we'll waste resources thrashing kernel_sendmsg 828 * with a bunch of small requests. 829 */ 830 static void xs_udp_write_space(struct sock *sk) 831 { 832 read_lock(&sk->sk_callback_lock); 833 834 /* from net/core/sock.c:sock_def_write_space */ 835 if (sock_writeable(sk)) { 836 struct socket *sock; 837 struct rpc_xprt *xprt; 838 839 if (unlikely(!(sock = sk->sk_socket))) 840 goto out; 841 if (unlikely(!(xprt = xprt_from_sock(sk)))) 842 goto out; 843 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags))) 844 goto out; 845 846 xprt_write_space(xprt); 847 } 848 849 out: 850 read_unlock(&sk->sk_callback_lock); 851 } 852 853 /** 854 * xs_tcp_write_space - callback invoked when socket buffer space 855 * becomes available 856 * @sk: socket whose state has changed 857 * 858 * Called when more output buffer space is available for this socket. 859 * We try not to wake our writers until they can make "significant" 860 * progress, otherwise we'll waste resources thrashing kernel_sendmsg 861 * with a bunch of small requests. 862 */ 863 static void xs_tcp_write_space(struct sock *sk) 864 { 865 read_lock(&sk->sk_callback_lock); 866 867 /* from net/core/stream.c:sk_stream_write_space */ 868 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { 869 struct socket *sock; 870 struct rpc_xprt *xprt; 871 872 if (unlikely(!(sock = sk->sk_socket))) 873 goto out; 874 if (unlikely(!(xprt = xprt_from_sock(sk)))) 875 goto out; 876 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags))) 877 goto out; 878 879 xprt_write_space(xprt); 880 } 881 882 out: 883 read_unlock(&sk->sk_callback_lock); 884 } 885 886 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt) 887 { 888 struct sock *sk = xprt->inet; 889 890 if (xprt->rcvsize) { 891 sk->sk_userlocks |= SOCK_RCVBUF_LOCK; 892 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs * 2; 893 } 894 if (xprt->sndsize) { 895 sk->sk_userlocks |= SOCK_SNDBUF_LOCK; 896 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2; 897 sk->sk_write_space(sk); 898 } 899 } 900 901 /** 902 * xs_udp_set_buffer_size - set send and receive limits 903 * @xprt: generic transport 904 * @sndsize: requested size of send buffer, in bytes 905 * @rcvsize: requested size of receive buffer, in bytes 906 * 907 * Set socket send and receive buffer size limits. 908 */ 909 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize) 910 { 911 xprt->sndsize = 0; 912 if (sndsize) 913 xprt->sndsize = sndsize + 1024; 914 xprt->rcvsize = 0; 915 if (rcvsize) 916 xprt->rcvsize = rcvsize + 1024; 917 918 xs_udp_do_set_buffer_size(xprt); 919 } 920 921 /** 922 * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport 923 * @task: task that timed out 924 * 925 * Adjust the congestion window after a retransmit timeout has occurred. 926 */ 927 static void xs_udp_timer(struct rpc_task *task) 928 { 929 xprt_adjust_cwnd(task, -ETIMEDOUT); 930 } 931 932 /** 933 * xs_set_port - reset the port number in the remote endpoint address 934 * @xprt: generic transport 935 * @port: new port number 936 * 937 */ 938 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port) 939 { 940 dprintk("RPC: setting port for xprt %p to %u\n", xprt, port); 941 xprt->addr.sin_port = htons(port); 942 } 943 944 static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock) 945 { 946 struct sockaddr_in myaddr = { 947 .sin_family = AF_INET, 948 }; 949 int err; 950 unsigned short port = xprt->port; 951 952 do { 953 myaddr.sin_port = htons(port); 954 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr, 955 sizeof(myaddr)); 956 if (err == 0) { 957 xprt->port = port; 958 dprintk("RPC: xs_bindresvport bound to port %u\n", 959 port); 960 return 0; 961 } 962 if (port <= xprt_min_resvport) 963 port = xprt_max_resvport; 964 else 965 port--; 966 } while (err == -EADDRINUSE && port != xprt->port); 967 968 dprintk("RPC: can't bind to reserved port (%d).\n", -err); 969 return err; 970 } 971 972 /** 973 * xs_udp_connect_worker - set up a UDP socket 974 * @args: RPC transport to connect 975 * 976 * Invoked by a work queue tasklet. 977 */ 978 static void xs_udp_connect_worker(void *args) 979 { 980 struct rpc_xprt *xprt = (struct rpc_xprt *) args; 981 struct socket *sock = xprt->sock; 982 int err, status = -EIO; 983 984 if (xprt->shutdown || xprt->addr.sin_port == 0) 985 goto out; 986 987 dprintk("RPC: xs_udp_connect_worker for xprt %p\n", xprt); 988 989 /* Start by resetting any existing state */ 990 xs_close(xprt); 991 992 if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) { 993 dprintk("RPC: can't create UDP transport socket (%d).\n", -err); 994 goto out; 995 } 996 997 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) { 998 sock_release(sock); 999 goto out; 1000 } 1001 1002 if (!xprt->inet) { 1003 struct sock *sk = sock->sk; 1004 1005 write_lock_bh(&sk->sk_callback_lock); 1006 1007 sk->sk_user_data = xprt; 1008 xprt->old_data_ready = sk->sk_data_ready; 1009 xprt->old_state_change = sk->sk_state_change; 1010 xprt->old_write_space = sk->sk_write_space; 1011 sk->sk_data_ready = xs_udp_data_ready; 1012 sk->sk_write_space = xs_udp_write_space; 1013 sk->sk_no_check = UDP_CSUM_NORCV; 1014 sk->sk_allocation = GFP_ATOMIC; 1015 1016 xprt_set_connected(xprt); 1017 1018 /* Reset to new socket */ 1019 xprt->sock = sock; 1020 xprt->inet = sk; 1021 1022 write_unlock_bh(&sk->sk_callback_lock); 1023 } 1024 xs_udp_do_set_buffer_size(xprt); 1025 status = 0; 1026 out: 1027 xprt_wake_pending_tasks(xprt, status); 1028 xprt_clear_connecting(xprt); 1029 } 1030 1031 /* 1032 * We need to preserve the port number so the reply cache on the server can 1033 * find our cached RPC replies when we get around to reconnecting. 1034 */ 1035 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt) 1036 { 1037 int result; 1038 struct socket *sock = xprt->sock; 1039 struct sockaddr any; 1040 1041 dprintk("RPC: disconnecting xprt %p to reuse port\n", xprt); 1042 1043 /* 1044 * Disconnect the transport socket by doing a connect operation 1045 * with AF_UNSPEC. This should return immediately... 1046 */ 1047 memset(&any, 0, sizeof(any)); 1048 any.sa_family = AF_UNSPEC; 1049 result = sock->ops->connect(sock, &any, sizeof(any), 0); 1050 if (result) 1051 dprintk("RPC: AF_UNSPEC connect return code %d\n", 1052 result); 1053 } 1054 1055 /** 1056 * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint 1057 * @args: RPC transport to connect 1058 * 1059 * Invoked by a work queue tasklet. 1060 */ 1061 static void xs_tcp_connect_worker(void *args) 1062 { 1063 struct rpc_xprt *xprt = (struct rpc_xprt *)args; 1064 struct socket *sock = xprt->sock; 1065 int err, status = -EIO; 1066 1067 if (xprt->shutdown || xprt->addr.sin_port == 0) 1068 goto out; 1069 1070 dprintk("RPC: xs_tcp_connect_worker for xprt %p\n", xprt); 1071 1072 if (!xprt->sock) { 1073 /* start from scratch */ 1074 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) { 1075 dprintk("RPC: can't create TCP transport socket (%d).\n", -err); 1076 goto out; 1077 } 1078 1079 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) { 1080 sock_release(sock); 1081 goto out; 1082 } 1083 } else 1084 /* "close" the socket, preserving the local port */ 1085 xs_tcp_reuse_connection(xprt); 1086 1087 if (!xprt->inet) { 1088 struct sock *sk = sock->sk; 1089 1090 write_lock_bh(&sk->sk_callback_lock); 1091 1092 sk->sk_user_data = xprt; 1093 xprt->old_data_ready = sk->sk_data_ready; 1094 xprt->old_state_change = sk->sk_state_change; 1095 xprt->old_write_space = sk->sk_write_space; 1096 sk->sk_data_ready = xs_tcp_data_ready; 1097 sk->sk_state_change = xs_tcp_state_change; 1098 sk->sk_write_space = xs_tcp_write_space; 1099 sk->sk_allocation = GFP_ATOMIC; 1100 1101 /* socket options */ 1102 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 1103 sock_reset_flag(sk, SOCK_LINGER); 1104 tcp_sk(sk)->linger2 = 0; 1105 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF; 1106 1107 xprt_clear_connected(xprt); 1108 1109 /* Reset to new socket */ 1110 xprt->sock = sock; 1111 xprt->inet = sk; 1112 1113 write_unlock_bh(&sk->sk_callback_lock); 1114 } 1115 1116 /* Tell the socket layer to start connecting... */ 1117 status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr, 1118 sizeof(xprt->addr), O_NONBLOCK); 1119 dprintk("RPC: %p connect status %d connected %d sock state %d\n", 1120 xprt, -status, xprt_connected(xprt), sock->sk->sk_state); 1121 if (status < 0) { 1122 switch (status) { 1123 case -EINPROGRESS: 1124 case -EALREADY: 1125 goto out_clear; 1126 case -ECONNREFUSED: 1127 case -ECONNRESET: 1128 /* retry with existing socket, after a delay */ 1129 break; 1130 default: 1131 /* get rid of existing socket, and retry */ 1132 xs_close(xprt); 1133 break; 1134 } 1135 } 1136 out: 1137 xprt_wake_pending_tasks(xprt, status); 1138 out_clear: 1139 xprt_clear_connecting(xprt); 1140 } 1141 1142 /** 1143 * xs_connect - connect a socket to a remote endpoint 1144 * @task: address of RPC task that manages state of connect request 1145 * 1146 * TCP: If the remote end dropped the connection, delay reconnecting. 1147 * 1148 * UDP socket connects are synchronous, but we use a work queue anyway 1149 * to guarantee that even unprivileged user processes can set up a 1150 * socket on a privileged port. 1151 * 1152 * If a UDP socket connect fails, the delay behavior here prevents 1153 * retry floods (hard mounts). 1154 */ 1155 static void xs_connect(struct rpc_task *task) 1156 { 1157 struct rpc_xprt *xprt = task->tk_xprt; 1158 1159 if (xprt_test_and_set_connecting(xprt)) 1160 return; 1161 1162 if (xprt->sock != NULL) { 1163 dprintk("RPC: xs_connect delayed xprt %p for %lu seconds\n", 1164 xprt, xprt->reestablish_timeout / HZ); 1165 schedule_delayed_work(&xprt->connect_worker, 1166 xprt->reestablish_timeout); 1167 xprt->reestablish_timeout <<= 1; 1168 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO) 1169 xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO; 1170 } else { 1171 dprintk("RPC: xs_connect scheduled xprt %p\n", xprt); 1172 schedule_work(&xprt->connect_worker); 1173 1174 /* flush_scheduled_work can sleep... */ 1175 if (!RPC_IS_ASYNC(task)) 1176 flush_scheduled_work(); 1177 } 1178 } 1179 1180 static struct rpc_xprt_ops xs_udp_ops = { 1181 .set_buffer_size = xs_udp_set_buffer_size, 1182 .reserve_xprt = xprt_reserve_xprt_cong, 1183 .release_xprt = xprt_release_xprt_cong, 1184 .set_port = xs_set_port, 1185 .connect = xs_connect, 1186 .buf_alloc = rpc_malloc, 1187 .buf_free = rpc_free, 1188 .send_request = xs_udp_send_request, 1189 .set_retrans_timeout = xprt_set_retrans_timeout_rtt, 1190 .timer = xs_udp_timer, 1191 .release_request = xprt_release_rqst_cong, 1192 .close = xs_close, 1193 .destroy = xs_destroy, 1194 }; 1195 1196 static struct rpc_xprt_ops xs_tcp_ops = { 1197 .reserve_xprt = xprt_reserve_xprt, 1198 .release_xprt = xprt_release_xprt, 1199 .set_port = xs_set_port, 1200 .connect = xs_connect, 1201 .buf_alloc = rpc_malloc, 1202 .buf_free = rpc_free, 1203 .send_request = xs_tcp_send_request, 1204 .set_retrans_timeout = xprt_set_retrans_timeout_def, 1205 .close = xs_close, 1206 .destroy = xs_destroy, 1207 }; 1208 1209 /** 1210 * xs_setup_udp - Set up transport to use a UDP socket 1211 * @xprt: transport to set up 1212 * @to: timeout parameters 1213 * 1214 */ 1215 int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to) 1216 { 1217 size_t slot_table_size; 1218 1219 dprintk("RPC: setting up udp-ipv4 transport...\n"); 1220 1221 xprt->max_reqs = xprt_udp_slot_table_entries; 1222 slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]); 1223 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL); 1224 if (xprt->slot == NULL) 1225 return -ENOMEM; 1226 memset(xprt->slot, 0, slot_table_size); 1227 1228 xprt->prot = IPPROTO_UDP; 1229 xprt->port = xprt_max_resvport; 1230 xprt->tsh_size = 0; 1231 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0; 1232 /* XXX: header size can vary due to auth type, IPv6, etc. */ 1233 xprt->max_payload = (1U << 16) - (MAX_HEADER << 3); 1234 1235 INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt); 1236 xprt->bind_timeout = XS_BIND_TO; 1237 xprt->connect_timeout = XS_UDP_CONN_TO; 1238 xprt->reestablish_timeout = XS_UDP_REEST_TO; 1239 xprt->idle_timeout = XS_IDLE_DISC_TO; 1240 1241 xprt->ops = &xs_udp_ops; 1242 1243 if (to) 1244 xprt->timeout = *to; 1245 else 1246 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ); 1247 1248 return 0; 1249 } 1250 1251 /** 1252 * xs_setup_tcp - Set up transport to use a TCP socket 1253 * @xprt: transport to set up 1254 * @to: timeout parameters 1255 * 1256 */ 1257 int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to) 1258 { 1259 size_t slot_table_size; 1260 1261 dprintk("RPC: setting up tcp-ipv4 transport...\n"); 1262 1263 xprt->max_reqs = xprt_tcp_slot_table_entries; 1264 slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]); 1265 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL); 1266 if (xprt->slot == NULL) 1267 return -ENOMEM; 1268 memset(xprt->slot, 0, slot_table_size); 1269 1270 xprt->prot = IPPROTO_TCP; 1271 xprt->port = xprt_max_resvport; 1272 xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32); 1273 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0; 1274 xprt->max_payload = RPC_MAX_FRAGMENT_SIZE; 1275 1276 INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt); 1277 xprt->bind_timeout = XS_BIND_TO; 1278 xprt->connect_timeout = XS_TCP_CONN_TO; 1279 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO; 1280 xprt->idle_timeout = XS_IDLE_DISC_TO; 1281 1282 xprt->ops = &xs_tcp_ops; 1283 1284 if (to) 1285 xprt->timeout = *to; 1286 else 1287 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ); 1288 1289 return 0; 1290 } 1291