mirrors/haproxy
1
0
Fork 0
mirror of https://git.haproxy.org/git/haproxy.git/ synced 2026-02-28 12:41:22 +01:00
Code Issues Projects Releases Wiki Activity
haproxy/src/stream_sock.c
Willy Tarreau 7154365cc6 [BUG] stream_sock: don't stop reading when the poller reports an error 
As reported by Jean-Baptiste Quenot and Robbie Aelter, sometimes a
backend server error is converted to a 502 error if the backend stops
before reading all the request. The reason is that the remote system
sends a TCP RST packet because there are still unread data pending in
the socket buffer. This RST is translated as a socket error on the
local system, and this error is reported by the poller.

However, most of the time, it's a write error, but the system is
still able to read the remaining pending data, such as in the trace
below :

send(7, "GET /aaa HTTP/1.0\r\nUser-Agent: Mo"..., 1123, MSG_DONTWAIT|MSG_NOSIGNAL) = 1123
epoll_ctl(3, EPOLL_CTL_ADD, 7, {EPOLLIN, {u32=7, u64=7}}) = 0
epoll_wait(3, {{EPOLLIN|EPOLLERR|EPOLLHUP, {u32=7, u64=7}}}, 8, 1000) = 1
gettimeofday({1247593958, 643572}, NULL) = 0
recv(7, "HTTP/1.0 400 Bad request\r\nCache-C"..., 7000, MSG_NOSIGNAL) = 187
setsockopt(6, SOL_TCP, TCP_NODELAY, [0], 4) = 0
setsockopt(6, SOL_TCP, TCP_CORK, [1], 4) = 0
send(6, "HTTP/1.0 400 Bad request\r\nCache-C"..., 187, MSG_DONTWAIT|MSG_NOSIGNAL) = 187
shutdown(6, 1 /* send */)               = 0

The recv succeeded while epoll_wait() reported an error.

Note: This case is very hard to reproduce and requires that the backend
server is reached via the loopback in order to minimise latency and
reduce the risk of sent data being ACKed.
2009-07-14 19:55:05 +02:00

1105 lines
31 KiB
C
Raw Blame History

/*
* Functions operating on SOCK_STREAM and buffers.
*
* Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <netinet/tcp.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <common/compat.h>
#include <common/config.h>
#include <common/debug.h>
#include <common/standard.h>
#include <common/ticks.h>
#include <common/time.h>
#include <proto/buffers.h>
#include <proto/client.h>
#include <proto/fd.h>
#include <proto/pipe.h>
#include <proto/stream_sock.h>
#include <proto/task.h>
#include <types/global.h>
/* On recent Linux kernels, the splice() syscall may be used for faster data copy.
* But it's not always defined on some OS versions, and it even happens that some
* definitions are wrong with some glibc due to an offset bug in syscall().
*/
#if defined(CONFIG_HAP_LINUX_SPLICE)
#include <unistd.h>
#include <sys/syscall.h>
#ifndef SPLICE_F_MOVE
#define SPLICE_F_MOVE 0x1
#endif
#ifndef SPLICE_F_NONBLOCK
#define SPLICE_F_NONBLOCK 0x2
#endif
#ifndef SPLICE_F_MORE
#define SPLICE_F_MORE 0x4
#endif
#ifndef __NR_splice
#if defined(__powerpc__) || defined(__powerpc64__)
#define __NR_splice 283
#elif defined(__sparc__) || defined(__sparc64__)
#define __NR_splice 232
#elif defined(__x86_64__)
#define __NR_splice 275
#elif defined(__alpha__)
#define __NR_splice 468
#elif defined (__i386__)
#define __NR_splice 313
#else
#warning unsupported architecture, guessing __NR_splice=313 like x86...
#define __NR_splice 313
#endif /* $arch */
_syscall6(int, splice, int, fdin, loff_t *, off_in, int, fdout, loff_t *, off_out, size_t, len, unsigned long, flags)
#endif /* __NR_splice */
/* A pipe contains 16 segments max, and it's common to see segments of 1448 bytes
* because of timestamps. Use this as a hint for not looping on splice().
*/
#define SPLICE_FULL_HINT 16*1448
/* Returns :
* -1 if splice is not possible or not possible anymore and we must switch to
* user-land copy (eg: to_forward reached)
* 0 when we know that polling is required to get more data (EAGAIN)
* 1 for all other cases (we can safely try again, or if an activity has been
* detected (DATA/NULL/ERR))
* Sets :
* BF_READ_NULL
* BF_READ_PARTIAL
* BF_WRITE_PARTIAL (during copy)
* BF_EMPTY (during copy)
* SI_FL_ERR
* SI_FL_WAIT_ROOM
* (SI_FL_WAIT_RECV)
*
* This function automatically allocates a pipe from the pipe pool. It also
* carefully ensures to clear b->pipe whenever it leaves the pipe empty.
*/
static int stream_sock_splice_in(struct buffer *b, struct stream_interface *si)
{
int fd = si->fd;
int ret, max, total = 0;
int retval = 1;
if (!b->to_forward)
return -1;
if (!(b->flags & BF_KERN_SPLICING))
return -1;
if (b->l) {
/* We're embarrassed, there are already data pending in
* the buffer and we don't want to have them at two
* locations at a time. Let's indicate we need some
* place and ask the consumer to hurry.
*/
si->flags |= SI_FL_WAIT_ROOM;
EV_FD_CLR(fd, DIR_RD);
b->rex = TICK_ETERNITY;
b->cons->chk_snd(b->cons);
return 1;
}
if (unlikely(b->pipe == NULL)) {
if (pipes_used >= global.maxpipes || !(b->pipe = get_pipe())) {
b->flags &= ~BF_KERN_SPLICING;
return -1;
}
}
/* At this point, b->pipe is valid */
while (1) {
max = b->to_forward;
if (max <= 0) {
/* It looks like the buffer + the pipe already contain
* the maximum amount of data to be transferred. Try to
* send those data immediately on the other side if it
* is currently waiting.
*/
retval = -1; /* end of forwarding */
break;
}
ret = splice(fd, NULL, b->pipe->prod, NULL, max,
SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
if (ret <= 0) {
if (ret == 0) {
/* connection closed. This is only detected by
* recent kernels (>= 2.6.27.13).
*/
b->flags |= BF_READ_NULL;
retval = 1; /* no need for further polling */
break;
}
if (errno == EAGAIN) {
/* there are two reasons for EAGAIN :
* - nothing in the socket buffer (standard)
* - pipe is full
* - the connection is closed (kernel < 2.6.27.13)
* Since we don't know if pipe is full, we'll
* stop if the pipe is not empty. Anyway, we
* will almost always fill/empty the pipe.
*/
if (b->pipe->data) {
si->flags |= SI_FL_WAIT_ROOM;
retval = 1;
break;
}
/* We don't know if the connection was closed.
* But if we're called upon POLLIN with an empty
* pipe and get EAGAIN, it is suspect enought to
* try to fall back to the normal recv scheme
* which will be able to deal with the situation.
*/
retval = -1;
break;
}
if (errno == ENOSYS) {
/* splice not supported on this end, disable it */
b->flags &= ~BF_KERN_SPLICING;
si->flags &= ~SI_FL_CAP_SPLICE;
put_pipe(b->pipe);
b->pipe = NULL;
return -1;
}
/* here we have another error */
si->flags |= SI_FL_ERR;
retval = 1;
break;
} /* ret <= 0 */
b->to_forward -= ret;
total += ret;
b->total += ret;
b->pipe->data += ret;
b->flags |= BF_READ_PARTIAL;
b->flags &= ~BF_EMPTY; /* to prevent shutdowns */
if (b->pipe->data >= SPLICE_FULL_HINT ||
ret >= global.tune.recv_enough) {
/* We've read enough of it for this time. */
retval = 1;
break;
}
} /* while */
if (unlikely(!b->pipe->data)) {
put_pipe(b->pipe);
b->pipe = NULL;
}
return retval;
}
#endif /* CONFIG_HAP_LINUX_SPLICE */
/*
* this function is called on a read event from a stream socket.
* It returns 0 if we have a high confidence that we will not be
* able to read more data without polling first. Returns non-zero
* otherwise.
*/
int stream_sock_read(int fd) {
struct stream_interface *si = fdtab[fd].owner;
struct buffer *b = si->ib;
int ret, max, retval, cur_read;
int read_poll = MAX_READ_POLL_LOOPS;
#ifdef DEBUG_FULL
fprintf(stderr,"stream_sock_read : fd=%d, ev=0x%02x, owner=%p\n", fd, fdtab[fd].ev, fdtab[fd].owner);
#endif
retval = 1;
/* stop immediately on errors. Note that we DON'T want to stop on
* POLL_ERR, as the poller might report a write error while there
* are still data available in the recv buffer. This typically
* happens when we send too large a request to a backend server
* which rejects it before reading it all.
*/
if (fdtab[fd].state == FD_STERROR)
goto out_error;
/* stop here if we reached the end of data */
if ((fdtab[fd].ev & (FD_POLL_IN|FD_POLL_HUP)) == FD_POLL_HUP)
goto out_shutdown_r;
/* maybe we were called immediately after an asynchronous shutr */
if (b->flags & BF_SHUTR)
goto out_wakeup;
#if defined(CONFIG_HAP_LINUX_SPLICE)
if (b->to_forward && b->flags & BF_KERN_SPLICING) {
/* Under Linux, if FD_POLL_HUP is set, we have reached the end.
* Since older splice() implementations were buggy and returned
* EAGAIN on end of read, let's bypass the call to splice() now.
*/
if (fdtab[fd].ev & FD_POLL_HUP)
goto out_shutdown_r;
retval = stream_sock_splice_in(b, si);
if (retval >= 0) {
if (si->flags & SI_FL_ERR)
goto out_error;
if (b->flags & BF_READ_NULL)
goto out_shutdown_r;
goto out_wakeup;
}
/* splice not possible (anymore), let's go on on standard copy */
}
#endif
cur_read = 0;
while (1) {
/*
* 1. compute the maximum block size we can read at once.
*/
if (b->l == 0) {
/* let's realign the buffer to optimize I/O */
b->r = b->w = b->lr = b->data;
max = b->max_len;
}
else if (b->r > b->w) {
max = b->data + b->max_len - b->r;
}
else {
max = b->w - b->r;
if (max > b->max_len)
max = b->max_len;
}
if (max == 0) {
b->flags |= BF_FULL;
si->flags |= SI_FL_WAIT_ROOM;
break;
}
/*
* 2. read the largest possible block
*/
#ifndef MSG_NOSIGNAL
{
int skerr;
socklen_t lskerr = sizeof(skerr);
ret = getsockopt(fd, SOL_SOCKET, SO_ERROR, &skerr, &lskerr);
if (ret == -1 || skerr)
ret = -1;
else
ret = recv(fd, b->r, max, 0);
}
#else
ret = recv(fd, b->r, max, MSG_NOSIGNAL);
#endif
if (ret > 0) {
b->r += ret;
b->l += ret;
cur_read += ret;
/* if we're allowed to directly forward data, we must update send_max */
if (b->to_forward > 0) {
int fwd = MIN(b->to_forward, ret);
b->send_max += fwd;
b->to_forward -= fwd;
}
if (fdtab[fd].state == FD_STCONN)
fdtab[fd].state = FD_STREADY;
b->flags |= BF_READ_PARTIAL;
b->flags &= ~BF_EMPTY;
if (b->r == b->data + BUFSIZE) {
b->r = b->data; /* wrap around the buffer */
}
b->total += ret;
if (b->l >= b->max_len) {
/* The buffer is now full, there's no point in going through
* the loop again.
*/
if (!(b->flags & BF_STREAMER_FAST) && (cur_read == b->l)) {
b->xfer_small = 0;
b->xfer_large++;
if (b->xfer_large >= 3) {
/* we call this buffer a fast streamer if it manages
* to be filled in one call 3 consecutive times.
*/
b->flags |= (BF_STREAMER | BF_STREAMER_FAST);
//fputc('+', stderr);
}
}
else if ((b->flags & (BF_STREAMER | BF_STREAMER_FAST)) &&
(cur_read <= BUFSIZE / 2)) {
b->xfer_large = 0;
b->xfer_small++;
if (b->xfer_small >= 2) {
/* if the buffer has been at least half full twice,
* we receive faster than we send, so at least it
* is not a "fast streamer".
*/
b->flags &= ~BF_STREAMER_FAST;
//fputc('-', stderr);
}
}
else {
b->xfer_small = 0;
b->xfer_large = 0;
}
b->flags |= BF_FULL;
si->flags |= SI_FL_WAIT_ROOM;
break;
}
/* if too many bytes were missing from last read, it means that
* it's pointless trying to read again because the system does
* not have them in buffers. BTW, if FD_POLL_HUP was present,
* it means that we have reached the end and that the connection
* is closed.
*/
if (ret < max) {
if ((b->flags & (BF_STREAMER | BF_STREAMER_FAST)) &&
(cur_read <= BUFSIZE / 2)) {
b->xfer_large = 0;
b->xfer_small++;
if (b->xfer_small >= 3) {
/* we have read less than half of the buffer in
* one pass, and this happened at least 3 times.
* This is definitely not a streamer.
*/
b->flags &= ~(BF_STREAMER | BF_STREAMER_FAST);
//fputc('!', stderr);
}
}
/* unfortunately, on level-triggered events, POLL_HUP
* is generally delivered AFTER the system buffer is
* empty, so this one might never match.
*/
if (fdtab[fd].ev & FD_POLL_HUP)
goto out_shutdown_r;
/* if a streamer has read few data, it may be because we
* have exhausted system buffers. It's not worth trying
* again.
*/
if (b->flags & BF_STREAMER)
break;
/* generally if we read something smaller than 1 or 2 MSS,
* it means that either we have exhausted the system's
* buffers (streamer or question-response protocol) or
* that the connection will be closed. Streamers are
* easily detected so we return early. For other cases,
* it's still better to perform a last read to be sure,
* because it may save one complete poll/read/wakeup cycle
* in case of shutdown.
*/
if (ret < MIN_RET_FOR_READ_LOOP && b->flags & BF_STREAMER)
break;
/* if we read a large block smaller than what we requested,
* it's almost certain we'll never get anything more.
*/
if (ret >= global.tune.recv_enough)
break;
}
if ((b->flags & BF_READ_DONTWAIT) || --read_poll <= 0)
break;
}
else if (ret == 0) {
/* connection closed */
goto out_shutdown_r;
}
else if (errno == EAGAIN) {
/* Ignore EAGAIN but inform the poller that there is
* nothing to read left if we did not read much, ie
* less than what we were still expecting to read.
* But we may have done some work justifying to notify
* the task.
*/
if (cur_read < MIN_RET_FOR_READ_LOOP)
retval = 0;
break;
}
else {
goto out_error;
}
} /* while (1) */
out_wakeup:
/* We might have some data the consumer is waiting for */
if ((b->send_max || b->pipe) && (b->cons->flags & SI_FL_WAIT_DATA)) {
int last_len = b->pipe ? b->pipe->data : 0;
b->cons->chk_snd(b->cons);
/* check if the consumer has freed some space */
if (!(b->flags & BF_FULL) &&
(!last_len || !b->pipe || b->pipe->data < last_len))
si->flags &= ~SI_FL_WAIT_ROOM;
}
if (si->flags & SI_FL_WAIT_ROOM) {
EV_FD_CLR(fd, DIR_RD);
b->rex = TICK_ETERNITY;
}
else if ((b->flags & (BF_SHUTR|BF_READ_PARTIAL|BF_FULL|BF_READ_NOEXP)) == BF_READ_PARTIAL)
b->rex = tick_add_ifset(now_ms, b->rto);
/* we have to wake up if there is a special event or if we don't have
* any more data to forward.
*/
if ((b->flags & (BF_READ_NULL|BF_READ_ERROR|BF_SHUTR|BF_READ_DONTWAIT)) ||
!b->to_forward ||
si->state != SI_ST_EST ||
b->cons->state != SI_ST_EST ||
(si->flags & SI_FL_ERR))
task_wakeup(si->owner, TASK_WOKEN_IO);
b->flags &= ~BF_READ_DONTWAIT;
fdtab[fd].ev &= ~FD_POLL_IN;
return retval;
out_shutdown_r:
/* we received a shutdown */
fdtab[fd].ev &= ~FD_POLL_HUP;
b->flags |= BF_READ_NULL;
stream_sock_shutr(si);
goto out_wakeup;
out_error:
/* Read error on the file descriptor. We mark the FD as STERROR so
* that we don't use it anymore. The error is reported to the stream
* interface which will take proper action. We must not perturbate the
* buffer because the stream interface wants to ensure transparent
* connection retries.
*/
fdtab[fd].state = FD_STERROR;
fdtab[fd].ev &= ~FD_POLL_STICKY;
EV_FD_REM(fd);
si->flags |= SI_FL_ERR;
retval = 1;
goto out_wakeup;
}
/*
* This function is called to send buffer data to a stream socket.
* It returns -1 in case of unrecoverable error, 0 if the caller needs to poll
* before calling it again, otherwise 1. If a pipe was associated with the
* buffer and it empties it, it releases it as well.
*/
static int stream_sock_write_loop(struct stream_interface *si, struct buffer *b)
{
int write_poll = MAX_WRITE_POLL_LOOPS;
int retval = 1;
int ret, max;
#if defined(CONFIG_HAP_LINUX_SPLICE)
while (b->pipe) {
ret = splice(b->pipe->cons, NULL, si->fd, NULL, b->pipe->data,
SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
if (ret <= 0) {
if (ret == 0 || errno == EAGAIN) {
retval = 0;
return retval;
}
/* here we have another error */
retval = -1;
return retval;
}
b->flags |= BF_WRITE_PARTIAL;
b->pipe->data -= ret;
if (!b->pipe->data) {
put_pipe(b->pipe);
b->pipe = NULL;
break;
}
if (--write_poll <= 0)
return retval;
}
/* At this point, the pipe is empty, but we may still have data pending
* in the normal buffer.
*/
if (!b->l) {
b->flags |= BF_EMPTY;
return retval;
}
#endif
if (!b->send_max)
return retval;
/* when we're in this loop, we already know that there is no spliced
* data left, and that there are sendable buffered data.
*/
while (1) {
if (b->r > b->w)
max = b->r - b->w;
else
max = b->data + BUFSIZE - b->w;
/* limit the amount of outgoing data if required */
if (max > b->send_max)
max = b->send_max;
#ifdef TCP_CORK
/*
* Check if we want to cork output before sending. This typically occurs
* when there are data left in the buffer, or when we reached the end of
* buffer but we know we will close, so we try to merge the ongoing FIN
* with the last data segment.
*/
if ((fdtab[si->fd].flags & (FD_FL_TCP|FD_FL_TCP_NOLING|FD_FL_TCP_CORK)) == FD_FL_TCP) {
if (unlikely((b->send_max == b->l &&
(b->flags & (BF_SHUTW|BF_SHUTW_NOW|BF_HIJACK|BF_WRITE_ENA|BF_SHUTR)) ==
(BF_WRITE_ENA|BF_SHUTR)))) {
/* we have to unconditionally reset TCP_NODELAY for CORK */
setsockopt(si->fd, IPPROTO_TCP, TCP_NODELAY, (char *) &zero, sizeof(zero));
setsockopt(si->fd, SOL_TCP, TCP_CORK, (char *) &one, sizeof(one));
fdtab[si->fd].flags = (fdtab[si->fd].flags & ~FD_FL_TCP_NODELAY) | FD_FL_TCP_CORK;
}
}
#endif
#ifndef MSG_NOSIGNAL
{
int skerr;
socklen_t lskerr = sizeof(skerr);
ret = getsockopt(si->fd, SOL_SOCKET, SO_ERROR, &skerr, &lskerr);
if (ret == -1 || skerr)
ret = -1;
else
ret = send(si->fd, b->w, max, MSG_DONTWAIT);
}
#else
ret = send(si->fd, b->w, max, MSG_DONTWAIT | MSG_NOSIGNAL);
#endif
if (ret > 0) {
if (fdtab[si->fd].state == FD_STCONN)
fdtab[si->fd].state = FD_STREADY;
b->flags |= BF_WRITE_PARTIAL;
b->w += ret;
if (b->w == b->data + BUFSIZE)
b->w = b->data; /* wrap around the buffer */
b->l -= ret;
if (likely(b->l < b->max_len))
b->flags &= ~BF_FULL;
if (likely(!b->l)) {
/* optimize data alignment in the buffer */
b->r = b->w = b->lr = b->data;
if (likely(!b->pipe))
b->flags |= BF_EMPTY;
}
b->send_max -= ret;
if (!b->send_max || !b->l)
break;
/* if the system buffer is full, don't insist */
if (ret < max)
break;
if (--write_poll <= 0)
break;
}
else if (ret == 0 || errno == EAGAIN) {
/* nothing written, we need to poll for write first */
retval = 0;
break;
}
else {
/* bad, we got an error */
retval = -1;
break;
}
} /* while (1) */
/* check if we need to uncork the output, for instance when the
* output buffer is empty but not shutr().
*/
if (unlikely((fdtab[si->fd].flags & (FD_FL_TCP|FD_FL_TCP_NODELAY)) == FD_FL_TCP && (b->flags & BF_EMPTY))) {
if ((b->flags & (BF_SHUTW|BF_SHUTW_NOW|BF_HIJACK|BF_WRITE_ENA|BF_SHUTR)) != (BF_WRITE_ENA|BF_SHUTR)) {
#ifdef TCP_CORK
if (fdtab[si->fd].flags & FD_FL_TCP_CORK)
setsockopt(si->fd, SOL_TCP, TCP_CORK, (char *) &zero, sizeof(zero));
#endif
setsockopt(si->fd, IPPROTO_TCP, TCP_NODELAY, (char *) &one, sizeof(one));
fdtab[si->fd].flags = (fdtab[si->fd].flags & ~FD_FL_TCP_CORK) | FD_FL_TCP_NODELAY;
}
}
return retval;
}
/*
* This function is called on a write event from a stream socket.
* It returns 0 if the caller needs to poll before calling it again, otherwise
* non-zero.
*/
int stream_sock_write(int fd)
{
struct stream_interface *si = fdtab[fd].owner;
struct buffer *b = si->ob;
int retval = 1;
#ifdef DEBUG_FULL
fprintf(stderr,"stream_sock_write : fd=%d, owner=%p\n", fd, fdtab[fd].owner);
#endif
retval = 1;
if (fdtab[fd].state == FD_STERROR)
goto out_error;
/* we might have been called just after an asynchronous shutw */
if (b->flags & BF_SHUTW)
goto out_wakeup;
if (likely(!(b->flags & BF_EMPTY))) {
/* OK there are data waiting to be sent */
retval = stream_sock_write_loop(si, b);
if (retval < 0)
goto out_error;
}
else {
/* may be we have received a connection acknowledgement in TCP mode without data */
if (likely(fdtab[fd].state == FD_STCONN)) {
/* We have no data to send to check the connection, and
* getsockopt() will not inform us whether the connection
* is still pending. So we'll reuse connect() to check the
* state of the socket. This has the advantage of givig us
* the following info :
* - error
* - connecting (EALREADY, EINPROGRESS)
* - connected (EISCONN, 0)
*/
if ((connect(fd, fdtab[fd].peeraddr, fdtab[fd].peerlen) == 0))
errno = 0;
if (errno == EALREADY || errno == EINPROGRESS) {
retval = 0;
goto out_may_wakeup;
}
if (errno && errno != EISCONN)
goto out_error;
/* OK we just need to indicate that we got a connection
* and that we wrote nothing.
*/
b->flags |= BF_WRITE_NULL;
fdtab[fd].state = FD_STREADY;
}
/* Funny, we were called to write something but there wasn't
* anything. We can get there, for example if we were woken up
* on a write event to finish the splice, but the send_max is 0
* so we cannot write anything from the buffer. Let's disable
* the write event and pretend we never came there.
*/
}
if (!b->pipe && !b->send_max) {
/* the connection is established but we can't write. Either the
* buffer is empty, or we just refrain from sending because the
* send_max limit was reached. Maybe we just wrote the last
* chunk and need to close.
*/
if (((b->flags & (BF_SHUTW|BF_EMPTY|BF_HIJACK|BF_WRITE_ENA|BF_SHUTR)) ==
(BF_EMPTY|BF_WRITE_ENA|BF_SHUTR)) &&
(si->state == SI_ST_EST)) {
stream_sock_shutw(si);
goto out_wakeup;
}
if ((b->flags & (BF_EMPTY|BF_SHUTW)) == BF_EMPTY)
si->flags |= SI_FL_WAIT_DATA;
EV_FD_CLR(fd, DIR_WR);
b->wex = TICK_ETERNITY;
}
out_may_wakeup:
if (b->flags & BF_WRITE_ACTIVITY) {
/* update timeout if we have written something */
if ((b->send_max || b->pipe) &&
(b->flags & (BF_SHUTW|BF_WRITE_PARTIAL)) == BF_WRITE_PARTIAL)
b->wex = tick_add_ifset(now_ms, b->wto);
out_wakeup:
if (tick_isset(si->ib->rex)) {
/* Note: to prevent the client from expiring read timeouts
* during writes, we refresh it. A better solution would be
* to merge read+write timeouts into a unique one, although
* that needs some study particularly on full-duplex TCP
* connections.
*/
si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
}
/* the producer might be waiting for more room to store data */
if (likely((b->flags & (BF_SHUTW|BF_WRITE_PARTIAL|BF_FULL)) == BF_WRITE_PARTIAL &&
(b->prod->flags & SI_FL_WAIT_ROOM)))
b->prod->chk_rcv(b->prod);
/* we have to wake up if there is a special event or if we don't have
* any more data to forward and it's not planned to send any more.
*/
if (likely((b->flags & (BF_WRITE_NULL|BF_WRITE_ERROR|BF_SHUTW)) ||
(!b->to_forward && !b->send_max && !b->pipe) ||
si->state != SI_ST_EST ||
b->prod->state != SI_ST_EST))
task_wakeup(si->owner, TASK_WOKEN_IO);
}
fdtab[fd].ev &= ~FD_POLL_OUT;
return retval;
out_error:
/* Write error on the file descriptor. We mark the FD as STERROR so
* that we don't use it anymore. The error is reported to the stream
* interface which will take proper action. We must not perturbate the
* buffer because the stream interface wants to ensure transparent
* connection retries.
*/
fdtab[fd].state = FD_STERROR;
fdtab[fd].ev &= ~FD_POLL_STICKY;
EV_FD_REM(fd);
si->flags |= SI_FL_ERR;
task_wakeup(si->owner, TASK_WOKEN_IO);
return 1;
}
/*
* This function performs a shutdown-write on a stream interface in a connected or
* init state (it does nothing for other states). It either shuts the write side
* or closes the file descriptor and marks itself as closed. The buffer flags are
* updated to reflect the new state.
*/
void stream_sock_shutw(struct stream_interface *si)
{
if (si->ob->flags & BF_SHUTW)
return;
si->ob->flags |= BF_SHUTW;
si->ob->wex = TICK_ETERNITY;
si->flags &= ~SI_FL_WAIT_DATA;
switch (si->state) {
case SI_ST_EST:
/* we have to shut before closing, otherwise some short messages
* may never leave the system, especially when there are remaining
* unread data in the socket input buffer, or when nolinger is set.
*/
EV_FD_CLR(si->fd, DIR_WR);
shutdown(si->fd, SHUT_WR);
if (!(si->ib->flags & BF_SHUTR))
return;
/* fall through */
case SI_ST_CON:
/* we may have to close a pending connection, and mark the
* response buffer as shutr
*/
fd_delete(si->fd);
/* fall through */
case SI_ST_CER:
si->state = SI_ST_DIS;
default:
si->flags &= ~SI_FL_WAIT_ROOM;
si->ib->flags |= BF_SHUTR;
si->ib->rex = TICK_ETERNITY;
si->exp = TICK_ETERNITY;
return;
}
}
/*
* This function performs a shutdown-read on a stream interface in a connected or
* init state (it does nothing for other states). It either shuts the read side
* or closes the file descriptor and marks itself as closed. The buffer flags are
* updated to reflect the new state.
*/
void stream_sock_shutr(struct stream_interface *si)
{
if (si->ib->flags & BF_SHUTR)
return;
si->ib->flags |= BF_SHUTR;
si->ib->rex = TICK_ETERNITY;
si->flags &= ~SI_FL_WAIT_ROOM;
if (si->state != SI_ST_EST && si->state != SI_ST_CON)
return;
if (si->ob->flags & BF_SHUTW) {
fd_delete(si->fd);
si->state = SI_ST_DIS;
si->exp = TICK_ETERNITY;
return;
}
EV_FD_CLR(si->fd, DIR_RD);
return;
}
/*
* Updates a connected stream_sock file descriptor status and timeouts
* according to the buffers' flags. It should only be called once after the
* buffer flags have settled down, and before they are cleared. It doesn't
* harm to call it as often as desired (it just slightly hurts performance).
*/
void stream_sock_data_finish(struct stream_interface *si)
{
struct buffer *ib = si->ib;
struct buffer *ob = si->ob;
int fd = si->fd;
DPRINTF(stderr,"[%u] %s: fd=%d owner=%p ib=%p, ob=%p, exp(r,w)=%u,%u ibf=%08x obf=%08x ibl=%d obl=%d si=%d\n",
now_ms, __FUNCTION__,
fd, fdtab[fd].owner,
ib, ob,
ib->rex, ob->wex,
ib->flags, ob->flags,
ib->l, ob->l, si->state);
/* Check if we need to close the read side */
if (!(ib->flags & BF_SHUTR)) {
/* Read not closed, update FD status and timeout for reads */
if (ib->flags & (BF_FULL|BF_HIJACK)) {
/* stop reading */
if ((ib->flags & (BF_FULL|BF_HIJACK)) == BF_FULL)
si->flags |= SI_FL_WAIT_ROOM;
EV_FD_COND_C(fd, DIR_RD);
ib->rex = TICK_ETERNITY;
}
else {
/* (re)start reading and update timeout. Note: we don't recompute the timeout
* everytime we get here, otherwise it would risk never to expire. We only
* update it if is was not yet set, or if we already got some read status.
*/
si->flags &= ~SI_FL_WAIT_ROOM;
EV_FD_COND_S(fd, DIR_RD);
if (!(ib->flags & BF_READ_NOEXP) &&
(!tick_isset(ib->rex) || ib->flags & BF_READ_ACTIVITY))
ib->rex = tick_add_ifset(now_ms, ib->rto);
}
}
/* Check if we need to close the write side */
if (!(ob->flags & BF_SHUTW)) {
/* Write not closed, update FD status and timeout for writes */
if ((ob->send_max == 0 && !ob->pipe) ||
(ob->flags & BF_EMPTY) ||
(ob->flags & (BF_HIJACK|BF_WRITE_ENA)) == 0) {
/* stop writing */
if ((ob->flags & (BF_EMPTY|BF_HIJACK|BF_WRITE_ENA)) == (BF_EMPTY|BF_WRITE_ENA))
si->flags |= SI_FL_WAIT_DATA;
EV_FD_COND_C(fd, DIR_WR);
ob->wex = TICK_ETERNITY;
}
else {
/* (re)start writing and update timeout. Note: we don't recompute the timeout
* everytime we get here, otherwise it would risk never to expire. We only
* update it if is was not yet set, or if we already got some write status.
*/
si->flags &= ~SI_FL_WAIT_DATA;
EV_FD_COND_S(fd, DIR_WR);
if (!tick_isset(ob->wex) || ob->flags & BF_WRITE_ACTIVITY) {
ob->wex = tick_add_ifset(now_ms, ob->wto);
if (tick_isset(ib->rex)) {
/* Note: depending on the protocol, we don't know if we're waiting
* for incoming data or not. So in order to prevent the socket from
* expiring read timeouts during writes, we refresh the read timeout,
* except if it was already infinite.
*/
ib->rex = tick_add_ifset(now_ms, ib->rto);
}
}
}
}
}
/* This function is used for inter-stream-interface calls. It is called by the
* consumer to inform the producer side that it may be interested in checking
* for free space in the buffer. Note that it intentionally does not update
* timeouts, so that we can still check them later at wake-up.
*/
void stream_sock_chk_rcv(struct stream_interface *si)
{
struct buffer *ib = si->ib;
DPRINTF(stderr,"[%u] %s: fd=%d owner=%p ib=%p, ob=%p, exp(r,w)=%u,%u ibf=%08x obf=%08x ibl=%d obl=%d si=%d\n",
now_ms, __FUNCTION__,
si->fd, fdtab[si->fd].owner,
ib, si->ob,
ib->rex, si->ob->wex,
ib->flags, si->ob->flags,
ib->l, si->ob->l, si->state);
if (unlikely(si->state != SI_ST_EST || (ib->flags & BF_SHUTR)))
return;
if (ib->flags & (BF_FULL|BF_HIJACK)) {
/* stop reading */
if ((ib->flags & (BF_FULL|BF_HIJACK)) == BF_FULL)
si->flags |= SI_FL_WAIT_ROOM;
EV_FD_COND_C(si->fd, DIR_RD);
}
else {
/* (re)start reading */
si->flags &= ~SI_FL_WAIT_ROOM;
EV_FD_COND_S(si->fd, DIR_RD);
}
}
/* This function is used for inter-stream-interface calls. It is called by the
* producer to inform the consumer side that it may be interested in checking
* for data in the buffer. Note that it intentionally does not update timeouts,
* so that we can still check them later at wake-up.
*/
void stream_sock_chk_snd(struct stream_interface *si)
{
struct buffer *ob = si->ob;
int retval;
DPRINTF(stderr,"[%u] %s: fd=%d owner=%p ib=%p, ob=%p, exp(r,w)=%u,%u ibf=%08x obf=%08x ibl=%d obl=%d si=%d\n",
now_ms, __FUNCTION__,
si->fd, fdtab[si->fd].owner,
si->ib, ob,
si->ib->rex, ob->wex,
si->ib->flags, ob->flags,
si->ib->l, ob->l, si->state);
if (unlikely(si->state != SI_ST_EST || (ob->flags & BF_SHUTW)))
return;
if (!(si->flags & SI_FL_WAIT_DATA) || /* not waiting for data */
(fdtab[si->fd].ev & FD_POLL_OUT) || /* we'll be called anyway */
!(ob->send_max || ob->pipe) || /* called with nothing to send ! */
!(ob->flags & (BF_HIJACK|BF_WRITE_ENA))) /* we may not write */
return;
retval = stream_sock_write_loop(si, ob);
if (retval < 0) {
/* Write error on the file descriptor. We mark the FD as STERROR so
* that we don't use it anymore and we notify the task.
*/
fdtab[si->fd].state = FD_STERROR;
fdtab[si->fd].ev &= ~FD_POLL_STICKY;
EV_FD_REM(si->fd);
si->flags |= SI_FL_ERR;
goto out_wakeup;
}
if (retval > 0 || (ob->send_max == 0 && !ob->pipe)) {
/* the connection is established but we can't write. Either the
* buffer is empty, or we just refrain from sending because the
* send_max limit was reached. Maybe we just wrote the last
* chunk and need to close.
*/
if (((ob->flags & (BF_SHUTW|BF_EMPTY|BF_HIJACK|BF_WRITE_ENA|BF_SHUTR)) ==
(BF_EMPTY|BF_WRITE_ENA|BF_SHUTR)) &&
(si->state == SI_ST_EST)) {
stream_sock_shutw(si);
goto out_wakeup;
}
if ((ob->flags & (BF_SHUTW|BF_EMPTY|BF_HIJACK|BF_WRITE_ENA)) == (BF_EMPTY|BF_WRITE_ENA))
si->flags |= SI_FL_WAIT_DATA;
ob->wex = TICK_ETERNITY;
}
else {
/* (re)start writing. */
si->flags &= ~SI_FL_WAIT_DATA;
EV_FD_COND_S(si->fd, DIR_WR);
}
if (likely(ob->flags & BF_WRITE_ACTIVITY)) {
/* update timeout if we have written something */
if ((ob->send_max || ob->pipe) &&
(ob->flags & (BF_SHUTW|BF_WRITE_PARTIAL)) == BF_WRITE_PARTIAL)
ob->wex = tick_add_ifset(now_ms, ob->wto);
if (tick_isset(si->ib->rex)) {
/* Note: to prevent the client from expiring read timeouts
* during writes, we refresh it. A better solution would be
* to merge read+write timeouts into a unique one, although
* that needs some study particularly on full-duplex TCP
* connections.
*/
si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
}
}
/* in case of special condition (error, shutdown, end of write...), we
* have to notify the task.
*/
if (likely((ob->flags & (BF_WRITE_NULL|BF_WRITE_ERROR|BF_SHUTW)) ||
(!ob->to_forward && !ob->send_max && !ob->pipe) ||
si->state != SI_ST_EST)) {
out_wakeup:
task_wakeup(si->owner, TASK_WOKEN_IO);
}
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/
Reference in New Issue View Git Blame Copy Permalink