blob: 9f7e979edf51b0e7a156acf9a867d048770d59de [file] [log] [blame]
/*
* Functions managing stream_interface structures
*
* Copyright 2000-2012 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.
*
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.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/channel.h>
#include <proto/connection.h>
#include <proto/fd.h>
#include <proto/pipe.h>
#include <proto/stream_interface.h>
#include <proto/task.h>
#include <types/pipe.h>
/* socket functions used when running a stream interface as a task */
static void stream_int_update_embedded(struct stream_interface *si);
static void stream_int_shutr(struct stream_interface *si);
static void stream_int_shutw(struct stream_interface *si);
static void stream_int_chk_rcv(struct stream_interface *si);
static void stream_int_chk_snd(struct stream_interface *si);
static void stream_int_update_conn(struct stream_interface *si);
static void stream_int_shutr_conn(struct stream_interface *si);
static void stream_int_shutw_conn(struct stream_interface *si);
static void stream_int_chk_rcv_conn(struct stream_interface *si);
static void stream_int_chk_snd_conn(struct stream_interface *si);
static void si_conn_recv_cb(struct connection *conn);
static void si_conn_send_cb(struct connection *conn);
static int si_conn_wake_cb(struct connection *conn);
static int si_idle_conn_wake_cb(struct connection *conn);
static void si_idle_conn_null_cb(struct connection *conn);
/* stream-interface operations for embedded tasks */
struct si_ops si_embedded_ops = {
.update = stream_int_update_embedded,
.chk_rcv = stream_int_chk_rcv,
.chk_snd = stream_int_chk_snd,
.shutr = stream_int_shutr,
.shutw = stream_int_shutw,
};
/* stream-interface operations for connections */
struct si_ops si_conn_ops = {
.update = stream_int_update_conn,
.chk_rcv = stream_int_chk_rcv_conn,
.chk_snd = stream_int_chk_snd_conn,
.shutr = stream_int_shutr_conn,
.shutw = stream_int_shutw_conn,
};
struct data_cb si_conn_cb = {
.recv = si_conn_recv_cb,
.send = si_conn_send_cb,
.wake = si_conn_wake_cb,
};
struct data_cb si_idle_conn_cb = {
.recv = si_idle_conn_null_cb,
.send = si_idle_conn_null_cb,
.wake = si_idle_conn_wake_cb,
};
/*
* This function only has to be called once after a wakeup event in case of
* suspected timeout. It controls the stream interface timeouts and sets
* si->flags accordingly. It does NOT close anything, as this timeout may
* be used for any purpose. It returns 1 if the timeout fired, otherwise
* zero.
*/
int stream_int_check_timeouts(struct stream_interface *si)
{
if (tick_is_expired(si->exp, now_ms)) {
si->flags |= SI_FL_EXP;
return 1;
}
return 0;
}
/* to be called only when in SI_ST_DIS with SI_FL_ERR */
void stream_int_report_error(struct stream_interface *si)
{
if (!si->err_type)
si->err_type = SI_ET_DATA_ERR;
si->ob->flags |= CF_WRITE_ERROR;
si->ib->flags |= CF_READ_ERROR;
}
/*
* Returns a message to the client ; the connection is shut down for read,
* and the request is cleared so that no server connection can be initiated.
* The buffer is marked for read shutdown on the other side to protect the
* message, and the buffer write is enabled. The message is contained in a
* "chunk". If it is null, then an empty message is used. The reply buffer does
* not need to be empty before this, and its contents will not be overwritten.
* The primary goal of this function is to return error messages to a client.
*/
void stream_int_retnclose(struct stream_interface *si, const struct chunk *msg)
{
channel_auto_read(si->ib);
channel_abort(si->ib);
channel_auto_close(si->ib);
channel_erase(si->ib);
bi_erase(si->ob);
if (likely(msg && msg->len))
bo_inject(si->ob, msg->str, msg->len);
si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
channel_auto_read(si->ob);
channel_auto_close(si->ob);
channel_shutr_now(si->ob);
}
/* default update function for embedded tasks, to be used at the end of the i/o handler */
static void stream_int_update_embedded(struct stream_interface *si)
{
int old_flags = si->flags;
DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
__FUNCTION__,
si, si->state, si->ib->flags, si->ob->flags);
if (si->state != SI_ST_EST)
return;
if ((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW &&
channel_is_empty(si->ob))
si_shutw(si);
if ((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0 && !channel_full(si->ob))
si->flags |= SI_FL_WAIT_DATA;
/* we're almost sure that we need some space if the buffer is not
* empty, even if it's not full, because the applets can't fill it.
*/
if ((si->ib->flags & (CF_SHUTR|CF_DONT_READ)) == 0 && !channel_is_empty(si->ib))
si->flags |= SI_FL_WAIT_ROOM;
if (si->ob->flags & CF_WRITE_ACTIVITY) {
if (tick_isset(si->ob->wex))
si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
}
if (si->ib->flags & CF_READ_ACTIVITY ||
(si->ob->flags & CF_WRITE_ACTIVITY && !(si->flags & SI_FL_INDEP_STR))) {
if (tick_isset(si->ib->rex))
si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
}
/* save flags to detect changes */
old_flags = si->flags;
if (likely((si->ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL|CF_DONT_READ)) == CF_WRITE_PARTIAL &&
!channel_full(si->ob) &&
(si->ob->prod->flags & SI_FL_WAIT_ROOM)))
si_chk_rcv(si->ob->prod);
if (((si->ib->flags & CF_READ_PARTIAL) && !channel_is_empty(si->ib)) &&
(si->ib->cons->flags & SI_FL_WAIT_DATA)) {
si_chk_snd(si->ib->cons);
/* check if the consumer has freed some space */
if (!channel_full(si->ib))
si->flags &= ~SI_FL_WAIT_ROOM;
}
/* Note that we're trying to wake up in two conditions here :
* - special event, which needs the holder task attention
* - status indicating that the applet can go on working. This
* is rather hard because we might be blocking on output and
* don't want to wake up on input and vice-versa. The idea is
* to only rely on the changes the chk_* might have performed.
*/
if (/* check stream interface changes */
((old_flags & ~si->flags) & (SI_FL_WAIT_ROOM|SI_FL_WAIT_DATA)) ||
/* changes on the production side */
(si->ib->flags & (CF_READ_NULL|CF_READ_ERROR)) ||
si->state != SI_ST_EST ||
(si->flags & SI_FL_ERR) ||
((si->ib->flags & CF_READ_PARTIAL) &&
(!si->ib->to_forward || si->ib->cons->state != SI_ST_EST)) ||
/* changes on the consumption side */
(si->ob->flags & (CF_WRITE_NULL|CF_WRITE_ERROR)) ||
((si->ob->flags & CF_WRITE_ACTIVITY) &&
((si->ob->flags & CF_SHUTW) ||
((si->ob->flags & CF_WAKE_WRITE) &&
(si->ob->prod->state != SI_ST_EST ||
(channel_is_empty(si->ob) && !si->ob->to_forward)))))) {
if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
task_wakeup(si->owner, TASK_WOKEN_IO);
}
if (si->ib->flags & CF_READ_ACTIVITY)
si->ib->flags &= ~CF_READ_DONTWAIT;
}
/*
* This function performs a shutdown-read on a stream interface attached to an
* applet in a connected or init state (it does nothing for other states). It
* either shuts the read side or marks itself as closed. The buffer flags are
* updated to reflect the new state. If the stream interface has SI_FL_NOHALF,
* we also forward the close to the write side. The owner task is woken up if
* it exists.
*/
static void stream_int_shutr(struct stream_interface *si)
{
si->ib->flags &= ~CF_SHUTR_NOW;
if (si->ib->flags & CF_SHUTR)
return;
si->ib->flags |= CF_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 & CF_SHUTW) {
si->state = SI_ST_DIS;
si->exp = TICK_ETERNITY;
si_applet_release(si);
}
else if (si->flags & SI_FL_NOHALF) {
/* we want to immediately forward this close to the write side */
return stream_int_shutw(si);
}
/* note that if the task exists, it must unregister itself once it runs */
if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
task_wakeup(si->owner, TASK_WOKEN_IO);
}
/*
* This function performs a shutdown-write on a stream interface attached to an
* applet in a connected or init state (it does nothing for other states). It
* either shuts the write side or marks itself as closed. The buffer flags are
* updated to reflect the new state. It does also close everything if the SI
* was marked as being in error state. The owner task is woken up if it exists.
*/
static void stream_int_shutw(struct stream_interface *si)
{
si->ob->flags &= ~CF_SHUTW_NOW;
if (si->ob->flags & CF_SHUTW)
return;
si->ob->flags |= CF_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.
* However, if SI_FL_NOLINGER is explicitly set, we know there is
* no risk so we close both sides immediately.
*/
if (!(si->flags & (SI_FL_ERR | SI_FL_NOLINGER)) &&
!(si->ib->flags & (CF_SHUTR|CF_DONT_READ)))
return;
/* fall through */
case SI_ST_CON:
case SI_ST_CER:
case SI_ST_QUE:
case SI_ST_TAR:
/* Note that none of these states may happen with applets */
si->state = SI_ST_DIS;
si_applet_release(si);
default:
si->flags &= ~(SI_FL_WAIT_ROOM | SI_FL_NOLINGER);
si->ib->flags &= ~CF_SHUTR_NOW;
si->ib->flags |= CF_SHUTR;
si->ib->rex = TICK_ETERNITY;
si->exp = TICK_ETERNITY;
}
/* note that if the task exists, it must unregister itself once it runs */
if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
task_wakeup(si->owner, TASK_WOKEN_IO);
}
/* default chk_rcv function for scheduled tasks */
static void stream_int_chk_rcv(struct stream_interface *si)
{
struct channel *ib = si->ib;
DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
__FUNCTION__,
si, si->state, si->ib->flags, si->ob->flags);
if (unlikely(si->state != SI_ST_EST || (ib->flags & (CF_SHUTR|CF_DONT_READ))))
return;
if (channel_full(ib)) {
/* stop reading */
si->flags |= SI_FL_WAIT_ROOM;
}
else {
/* (re)start reading */
si->flags &= ~SI_FL_WAIT_ROOM;
if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
task_wakeup(si->owner, TASK_WOKEN_IO);
}
}
/* default chk_snd function for scheduled tasks */
static void stream_int_chk_snd(struct stream_interface *si)
{
struct channel *ob = si->ob;
DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
__FUNCTION__,
si, si->state, si->ib->flags, si->ob->flags);
if (unlikely(si->state != SI_ST_EST || (si->ob->flags & CF_SHUTW)))
return;
if (!(si->flags & SI_FL_WAIT_DATA) || /* not waiting for data */
channel_is_empty(ob)) /* called with nothing to send ! */
return;
/* Otherwise there are remaining data to be sent in the buffer,
* so we tell the handler.
*/
si->flags &= ~SI_FL_WAIT_DATA;
if (!tick_isset(ob->wex))
ob->wex = tick_add_ifset(now_ms, ob->wto);
if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
task_wakeup(si->owner, TASK_WOKEN_IO);
}
/* Register an applet to handle a stream_interface as part of the
* stream interface's owner task. The SI will wake it up everytime it
* is solicited. The task's processing function must call the applet's
* function before returning. It must be deleted by the task handler
* using stream_int_unregister_handler(), possibly from within the
* function itself. It also pre-initializes the applet's context and
* returns it (or NULL in case it could not be allocated).
*/
struct appctx *stream_int_register_handler(struct stream_interface *si, struct si_applet *app)
{
struct appctx *appctx;
DPRINTF(stderr, "registering handler %p for si %p (was %p)\n", app, si, si->owner);
appctx = si_alloc_appctx(si);
if (!si)
return NULL;
appctx_set_applet(appctx, app);
si->flags |= SI_FL_WAIT_DATA;
return si_appctx(si);
}
/* Unregister a stream interface handler. This must be called by the handler task
* itself when it detects that it is in the SI_ST_DIS state.
*/
void stream_int_unregister_handler(struct stream_interface *si)
{
si_detach(si);
}
/* This callback is used to send a valid PROXY protocol line to a socket being
* established. It returns 0 if it fails in a fatal way or needs to poll to go
* further, otherwise it returns non-zero and removes itself from the connection's
* flags (the bit is provided in <flag> by the caller). It is designed to be
* called by the connection handler and relies on it to commit polling changes.
* Note that it can emit a PROXY line by relying on the other end's address
* when the connection is attached to a stream interface, or by resolving the
* local address otherwise (also called a LOCAL line).
*/
int conn_si_send_proxy(struct connection *conn, unsigned int flag)
{
/* we might have been called just after an asynchronous shutw */
if (conn->flags & CO_FL_SOCK_WR_SH)
goto out_error;
if (!conn_ctrl_ready(conn))
goto out_error;
if (!fd_send_ready(conn->t.sock.fd))
goto out_wait;
/* If we have a PROXY line to send, we'll use this to validate the
* connection, in which case the connection is validated only once
* we've sent the whole proxy line. Otherwise we use connect().
*/
while (conn->send_proxy_ofs) {
int ret;
/* The target server expects a PROXY line to be sent first.
* If the send_proxy_ofs is negative, it corresponds to the
* offset to start sending from then end of the proxy string
* (which is recomputed every time since it's constant). If
* it is positive, it means we have to send from the start.
* We can only send a "normal" PROXY line when the connection
* is attached to a stream interface. Otherwise we can only
* send a LOCAL line (eg: for use with health checks).
*/
if (conn->data == &si_conn_cb) {
struct stream_interface *si = conn->owner;
struct connection *remote = objt_conn(si->ob->prod->end);
ret = make_proxy_line(trash.str, trash.size, objt_server(conn->target), remote);
}
else {
/* The target server expects a LOCAL line to be sent first. Retrieving
* local or remote addresses may fail until the connection is established.
*/
conn_get_from_addr(conn);
if (!(conn->flags & CO_FL_ADDR_FROM_SET))
goto out_wait;
conn_get_to_addr(conn);
if (!(conn->flags & CO_FL_ADDR_TO_SET))
goto out_wait;
ret = make_proxy_line(trash.str, trash.size, objt_server(conn->target), conn);
}
if (!ret)
goto out_error;
if (conn->send_proxy_ofs > 0)
conn->send_proxy_ofs = -ret; /* first call */
/* we have to send trash from (ret+sp for -sp bytes). If the
* data layer has a pending write, we'll also set MSG_MORE.
*/
ret = send(conn->t.sock.fd, trash.str + ret + conn->send_proxy_ofs, -conn->send_proxy_ofs,
(conn->flags & CO_FL_DATA_WR_ENA) ? MSG_MORE : 0);
if (ret == 0)
goto out_wait;
if (ret < 0) {
if (errno == EAGAIN || errno == ENOTCONN)
goto out_wait;
if (errno == EINTR)
continue;
conn->flags |= CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
goto out_error;
}
conn->send_proxy_ofs += ret; /* becomes zero once complete */
if (conn->send_proxy_ofs != 0)
goto out_wait;
/* OK we've sent the whole line, we're connected */
break;
}
/* The connection is ready now, simply return and let the connection
* handler notify upper layers if needed.
*/
if (conn->flags & CO_FL_WAIT_L4_CONN)
conn->flags &= ~CO_FL_WAIT_L4_CONN;
conn->flags &= ~flag;
return 1;
out_error:
/* Write error on the file descriptor */
conn->flags |= CO_FL_ERROR;
return 0;
out_wait:
__conn_sock_stop_recv(conn);
fd_cant_send(conn->t.sock.fd);
return 0;
}
/* Tiny I/O callback called on recv/send I/O events on idle connections.
* It simply sets the CO_FL_SOCK_RD_SH flag so that si_idle_conn_wake_cb()
* is notified and can kill the connection.
*/
static void si_idle_conn_null_cb(struct connection *conn)
{
if (conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH))
return;
if (fdtab[conn->t.sock.fd].ev & (FD_POLL_ERR|FD_POLL_HUP)) {
fdtab[conn->t.sock.fd].linger_risk = 0;
conn->flags |= CO_FL_SOCK_RD_SH;
}
else {
conn_drain(conn);
}
/* disable draining if we were called and have no drain function */
if (!conn->ctrl->drain)
__conn_data_stop_recv(conn);
}
/* Callback to be used by connection I/O handlers when some activity is detected
* on an idle server connection. Its main purpose is to kill the connection once
* a close was detected on it. It returns 0 if it did nothing serious, or -1 if
* it killed the connection.
*/
static int si_idle_conn_wake_cb(struct connection *conn)
{
struct stream_interface *si = conn->owner;
if (!conn_ctrl_ready(conn))
return 0;
if (conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH)) {
/* warning, we can't do anything on <conn> after this call ! */
conn_force_close(conn);
conn_free(conn);
si->end = NULL;
return -1;
}
return 0;
}
/* Callback to be used by connection I/O handlers upon completion. It differs from
* the update function in that it is designed to be called by lower layers after I/O
* events have been completed. It will also try to wake the associated task up if
* an important event requires special handling. It relies on the connection handler
* to commit any polling updates. The function always returns 0.
*/
static int si_conn_wake_cb(struct connection *conn)
{
struct stream_interface *si = conn->owner;
DPRINTF(stderr, "%s: si=%p, si->state=%d ib->flags=%08x ob->flags=%08x\n",
__FUNCTION__,
si, si->state, si->ib->flags, si->ob->flags);
if (conn->flags & CO_FL_ERROR)
si->flags |= SI_FL_ERR;
/* check for recent connection establishment */
if (unlikely(!(conn->flags & (CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN | CO_FL_CONNECTED)))) {
si->exp = TICK_ETERNITY;
si->ob->flags |= CF_WRITE_NULL;
}
/* process consumer side */
if (channel_is_empty(si->ob)) {
if (((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW) &&
(si->state == SI_ST_EST))
stream_int_shutw_conn(si);
__conn_data_stop_send(conn);
si->ob->wex = TICK_ETERNITY;
}
if ((si->ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0 && !channel_full(si->ob))
si->flags |= SI_FL_WAIT_DATA;
if (si->ob->flags & CF_WRITE_ACTIVITY) {
/* update timeouts if we have written something */
if ((si->ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
!channel_is_empty(si->ob))
if (tick_isset(si->ob->wex))
si->ob->wex = tick_add_ifset(now_ms, si->ob->wto);
if (!(si->flags & SI_FL_INDEP_STR))
if (tick_isset(si->ib->rex))
si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
if (likely((si->ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL|CF_DONT_READ)) == CF_WRITE_PARTIAL &&
!channel_full(si->ob) &&
(si->ob->prod->flags & SI_FL_WAIT_ROOM)))
si_chk_rcv(si->ob->prod);
}
/* process producer side.
* We might have some data the consumer is waiting for.
* We can do fast-forwarding, but we avoid doing this for partial
* buffers, because it is very likely that it will be done again
* immediately afterwards once the following data is parsed (eg:
* HTTP chunking).
*/
if (((si->ib->flags & CF_READ_PARTIAL) && !channel_is_empty(si->ib)) &&
(si->ib->pipe /* always try to send spliced data */ ||
(si->ib->buf->i == 0 && (si->ib->cons->flags & SI_FL_WAIT_DATA)))) {
int last_len = si->ib->pipe ? si->ib->pipe->data : 0;
si_chk_snd(si->ib->cons);
/* check if the consumer has freed some space either in the
* buffer or in the pipe.
*/
if (!channel_full(si->ib) &&
(!last_len || !si->ib->pipe || si->ib->pipe->data < last_len))
si->flags &= ~SI_FL_WAIT_ROOM;
}
if (si->flags & SI_FL_WAIT_ROOM) {
__conn_data_stop_recv(conn);
si->ib->rex = TICK_ETERNITY;
}
else if ((si->ib->flags & (CF_SHUTR|CF_READ_PARTIAL|CF_DONT_READ)) == CF_READ_PARTIAL &&
!channel_full(si->ib)) {
/* we must re-enable reading if si_chk_snd() has freed some space */
__conn_data_want_recv(conn);
if (!(si->ib->flags & CF_READ_NOEXP) && tick_isset(si->ib->rex))
si->ib->rex = tick_add_ifset(now_ms, si->ib->rto);
}
/* wake the task up only when needed */
if (/* changes on the production side */
(si->ib->flags & (CF_READ_NULL|CF_READ_ERROR)) ||
si->state != SI_ST_EST ||
(si->flags & SI_FL_ERR) ||
((si->ib->flags & CF_READ_PARTIAL) &&
(!si->ib->to_forward || si->ib->cons->state != SI_ST_EST)) ||
/* changes on the consumption side */
(si->ob->flags & (CF_WRITE_NULL|CF_WRITE_ERROR)) ||
((si->ob->flags & CF_WRITE_ACTIVITY) &&
((si->ob->flags & CF_SHUTW) ||
((si->ob->flags & CF_WAKE_WRITE) &&
(si->ob->prod->state != SI_ST_EST ||
(channel_is_empty(si->ob) && !si->ob->to_forward)))))) {
task_wakeup(si->owner, TASK_WOKEN_IO);
}
if (si->ib->flags & CF_READ_ACTIVITY)
si->ib->flags &= ~CF_READ_DONTWAIT;
return 0;
}
/*
* This function is called to send buffer data to a stream socket.
* It calls the transport layer's snd_buf function. It relies on the
* caller to commit polling changes. The caller should check conn->flags
* for errors.
*/
static void si_conn_send(struct connection *conn)
{
struct stream_interface *si = conn->owner;
struct channel *chn = si->ob;
int ret;
if (chn->pipe && conn->xprt->snd_pipe) {
ret = conn->xprt->snd_pipe(conn, chn->pipe);
if (ret > 0)
chn->flags |= CF_WRITE_PARTIAL | CF_WROTE_DATA;
if (!chn->pipe->data) {
put_pipe(chn->pipe);
chn->pipe = NULL;
}
if (conn->flags & CO_FL_ERROR)
return;
}
/* At this point, the pipe is empty, but we may still have data pending
* in the normal buffer.
*/
if (!chn->buf->o)
return;
/* when we're here, we already know that there is no spliced
* data left, and that there are sendable buffered data.
*/
if (!(conn->flags & (CO_FL_ERROR | CO_FL_SOCK_WR_SH | CO_FL_DATA_WR_SH | CO_FL_WAIT_DATA | CO_FL_HANDSHAKE))) {
/* check if we want to inform the kernel that we're interested in
* sending more data after this call. We want this if :
* - we're about to close after this last send and want to merge
* the ongoing FIN with the last segment.
* - we know we can't send everything at once and must get back
* here because of unaligned data
* - there is still a finite amount of data to forward
* The test is arranged so that the most common case does only 2
* tests.
*/
unsigned int send_flag = 0;
if ((!(chn->flags & (CF_NEVER_WAIT|CF_SEND_DONTWAIT)) &&
((chn->to_forward && chn->to_forward != CHN_INFINITE_FORWARD) ||
(chn->flags & CF_EXPECT_MORE))) ||
((chn->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW))
send_flag |= CO_SFL_MSG_MORE;
if (chn->flags & CF_STREAMER)
send_flag |= CO_SFL_STREAMER;
ret = conn->xprt->snd_buf(conn, chn->buf, send_flag);
if (ret > 0) {
chn->flags |= CF_WRITE_PARTIAL | CF_WROTE_DATA;
if (!chn->buf->o) {
/* Always clear both flags once everything has been sent, they're one-shot */
chn->flags &= ~(CF_EXPECT_MORE | CF_SEND_DONTWAIT);
}
/* if some data remain in the buffer, it's only because the
* system buffers are full, we will try next time.
*/
}
}
return;
}
/* Updates the timers and flags of a stream interface attached to a connection,
* depending on 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).
* It is only meant to be called by upper layers after buffer flags have been
* manipulated by analysers.
*/
void stream_int_update_conn(struct stream_interface *si)
{
struct channel *ib = si->ib;
struct channel *ob = si->ob;
struct connection *conn = __objt_conn(si->end);
/* Check if we need to close the read side */
if (!(ib->flags & CF_SHUTR)) {
/* Read not closed, update FD status and timeout for reads */
if ((ib->flags & CF_DONT_READ) || channel_full(ib)) {
/* stop reading */
if (!(si->flags & SI_FL_WAIT_ROOM)) {
if (!(ib->flags & CF_DONT_READ)) /* full */
si->flags |= SI_FL_WAIT_ROOM;
conn_data_stop_recv(conn);
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. The stream socket handler will already
* have updated it if there has been a completed I/O.
*/
si->flags &= ~SI_FL_WAIT_ROOM;
conn_data_want_recv(conn);
if (!(ib->flags & (CF_READ_NOEXP|CF_DONT_READ)) && !tick_isset(ib->rex))
ib->rex = tick_add_ifset(now_ms, ib->rto);
}
}
/* Check if we need to close the write side */
if (!(ob->flags & CF_SHUTW)) {
/* Write not closed, update FD status and timeout for writes */
if (channel_is_empty(ob)) {
/* stop writing */
if (!(si->flags & SI_FL_WAIT_DATA)) {
if ((ob->flags & CF_SHUTW_NOW) == 0)
si->flags |= SI_FL_WAIT_DATA;
conn_data_stop_send(conn);
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. The stream socket handler will already
* have updated it if there has been a completed I/O.
*/
si->flags &= ~SI_FL_WAIT_DATA;
conn_data_want_send(conn);
if (!tick_isset(ob->wex)) {
ob->wex = tick_add_ifset(now_ms, ob->wto);
if (tick_isset(ib->rex) && !(si->flags & SI_FL_INDEP_STR)) {
/* 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 or if we have explicitly setup
* independent streams.
*/
ib->rex = tick_add_ifset(now_ms, ib->rto);
}
}
}
}
}
/*
* This function performs a shutdown-read on a stream interface attached to
* a connection in a connected or init state (it does nothing for other
* states). It either shuts the read side or marks itself as closed. The buffer
* flags are updated to reflect the new state. If the stream interface has
* SI_FL_NOHALF, we also forward the close to the write side. If a control
* layer is defined, then it is supposed to be a socket layer and file
* descriptors are then shutdown or closed accordingly. The function
* automatically disables polling if needed.
*/
static void stream_int_shutr_conn(struct stream_interface *si)
{
struct connection *conn = __objt_conn(si->end);
si->ib->flags &= ~CF_SHUTR_NOW;
if (si->ib->flags & CF_SHUTR)
return;
si->ib->flags |= CF_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 & CF_SHUTW) {
conn_full_close(conn);
si->state = SI_ST_DIS;
si->exp = TICK_ETERNITY;
}
else if (si->flags & SI_FL_NOHALF) {
/* we want to immediately forward this close to the write side */
return stream_int_shutw_conn(si);
}
else if (conn->ctrl) {
/* we want the caller to disable polling on this FD */
conn_data_stop_recv(conn);
}
}
/*
* This function performs a shutdown-write on a stream interface attached to
* a connection in a connected or init state (it does nothing for other
* states). It either shuts the write side or marks itself as closed. The
* buffer flags are updated to reflect the new state. It does also close
* everything if the SI was marked as being in error state. If there is a
* data-layer shutdown, it is called. If a control layer is defined, then it is
* supposed to be a socket layer and file descriptors are then shutdown or
* closed accordingly. The function automatically disables polling if needed.
* Note: at the moment, we continue to check conn->ctrl eventhough we *know* it
* is valid. This will help selecting the proper shutdown() and setsockopt()
* calls if/when we implement remote sockets later.
*/
static void stream_int_shutw_conn(struct stream_interface *si)
{
struct connection *conn = __objt_conn(si->end);
si->ob->flags &= ~CF_SHUTW_NOW;
if (si->ob->flags & CF_SHUTW)
return;
si->ob->flags |= CF_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.
* However, if SI_FL_NOLINGER is explicitly set, we know there is
* no risk so we close both sides immediately.
*/
if (si->flags & SI_FL_ERR) {
/* quick close, the socket is alredy shut anyway */
}
else if (si->flags & SI_FL_NOLINGER) {
/* unclean data-layer shutdown */
if (conn->xprt && conn->xprt->shutw)
conn->xprt->shutw(conn, 0);
}
else {
/* clean data-layer shutdown */
if (conn->xprt && conn->xprt->shutw)
conn->xprt->shutw(conn, 1);
/* If the stream interface is configured to disable half-open
* connections, we'll skip the shutdown(), but only if the
* read size is already closed. Otherwise we can't support
* closed write with pending read (eg: abortonclose while
* waiting for the server).
*/
if (!(si->flags & SI_FL_NOHALF) || !(si->ib->flags & (CF_SHUTR|CF_DONT_READ))) {
/* We shutdown transport layer */
if (conn_ctrl_ready(conn))
shutdown(conn->t.sock.fd, SHUT_WR);
if (!(si->ib->flags & (CF_SHUTR|CF_DONT_READ))) {
/* OK just a shutw, but we want the caller
* to disable polling on this FD if exists.
*/
if (conn->ctrl)
conn_data_stop_send(conn);
return;
}
}
}
/* fall through */
case SI_ST_CON:
/* we may have to close a pending connection, and mark the
* response buffer as shutr
*/
conn_full_close(conn);
/* fall through */
case SI_ST_CER:
case SI_ST_QUE:
case SI_ST_TAR:
si->state = SI_ST_DIS;
/* fall through */
default:
si->flags &= ~(SI_FL_WAIT_ROOM | SI_FL_NOLINGER);
si->ib->flags &= ~CF_SHUTR_NOW;
si->ib->flags |= CF_SHUTR;
si->ib->rex = TICK_ETERNITY;
si->exp = TICK_ETERNITY;
}
}
/* 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. This function is
* dedicated to connection-based stream interfaces.
*/
static void stream_int_chk_rcv_conn(struct stream_interface *si)
{
struct channel *ib = si->ib;
struct connection *conn = __objt_conn(si->end);
if (unlikely(si->state > SI_ST_EST || (ib->flags & CF_SHUTR)))
return;
conn_refresh_polling_flags(conn);
if ((ib->flags & CF_DONT_READ) || channel_full(ib)) {
/* stop reading */
if (!(ib->flags & CF_DONT_READ)) /* full */
si->flags |= SI_FL_WAIT_ROOM;
__conn_data_stop_recv(conn);
}
else {
/* (re)start reading */
si->flags &= ~SI_FL_WAIT_ROOM;
__conn_data_want_recv(conn);
}
conn_cond_update_data_polling(conn);
}
/* 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.
*/
static void stream_int_chk_snd_conn(struct stream_interface *si)
{
struct channel *ob = si->ob;
struct connection *conn = __objt_conn(si->end);
if (unlikely(si->state > SI_ST_EST || (ob->flags & CF_SHUTW)))
return;
if (unlikely(channel_is_empty(ob))) /* called with nothing to send ! */
return;
if (!ob->pipe && /* spliced data wants to be forwarded ASAP */
!(si->flags & SI_FL_WAIT_DATA)) /* not waiting for data */
return;
if (conn->flags & (CO_FL_DATA_WR_ENA|CO_FL_CURR_WR_ENA)) {
/* already subscribed to write notifications, will be called
* anyway, so let's avoid calling it especially if the reader
* is not ready.
*/
return;
}
/* Before calling the data-level operations, we have to prepare
* the polling flags to ensure we properly detect changes.
*/
conn_refresh_polling_flags(conn);
__conn_data_want_send(conn);
if (!(conn->flags & (CO_FL_HANDSHAKE|CO_FL_WAIT_L4_CONN|CO_FL_WAIT_L6_CONN))) {
si_conn_send(conn);
if (conn->flags & CO_FL_ERROR) {
/* Write error on the file descriptor */
__conn_data_stop_both(conn);
si->flags |= SI_FL_ERR;
goto out_wakeup;
}
}
/* OK, so now we know that some data might have been sent, and that we may
* have to poll first. We have to do that too if the buffer is not empty.
*/
if (channel_is_empty(ob)) {
/* the connection is established but we can't write. Either the
* buffer is empty, or we just refrain from sending because the
* ->o limit was reached. Maybe we just wrote the last
* chunk and need to close.
*/
__conn_data_stop_send(conn);
if (((ob->flags & (CF_SHUTW|CF_AUTO_CLOSE|CF_SHUTW_NOW)) ==
(CF_AUTO_CLOSE|CF_SHUTW_NOW)) &&
(si->state == SI_ST_EST)) {
si_shutw(si);
goto out_wakeup;
}
if ((ob->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0)
si->flags |= SI_FL_WAIT_DATA;
ob->wex = TICK_ETERNITY;
}
else {
/* Otherwise there are remaining data to be sent in the buffer,
* which means we have to poll before doing so.
*/
__conn_data_want_send(conn);
si->flags &= ~SI_FL_WAIT_DATA;
if (!tick_isset(ob->wex))
ob->wex = tick_add_ifset(now_ms, ob->wto);
}
if (likely(ob->flags & CF_WRITE_ACTIVITY)) {
/* update timeout if we have written something */
if ((ob->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
!channel_is_empty(ob))
ob->wex = tick_add_ifset(now_ms, ob->wto);
if (tick_isset(si->ib->rex) && !(si->flags & SI_FL_INDEP_STR)) {
/* Note: to prevent the client from expiring read timeouts
* during writes, we refresh it. We only do this if the
* interface is not configured for "independent streams",
* because for some applications it's better not to do this,
* for instance when continuously exchanging small amounts
* of data which can full the socket buffers long before a
* write timeout is detected.
*/
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 & (CF_WRITE_NULL|CF_WRITE_ERROR|CF_SHUTW)) ||
((ob->flags & CF_WAKE_WRITE) &&
((channel_is_empty(si->ob) && !ob->to_forward) ||
si->state != SI_ST_EST)))) {
out_wakeup:
if (!(si->flags & SI_FL_DONT_WAKE) && si->owner)
task_wakeup(si->owner, TASK_WOKEN_IO);
}
/* commit possible polling changes */
conn_cond_update_polling(conn);
}
/*
* This is the callback which is called by the connection layer to receive data
* into the buffer from the connection. It iterates over the transport layer's
* rcv_buf function.
*/
static void si_conn_recv_cb(struct connection *conn)
{
struct stream_interface *si = conn->owner;
struct channel *chn = si->ib;
int ret, max, cur_read;
int read_poll = MAX_READ_POLL_LOOPS;
/* 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 (conn->flags & CO_FL_ERROR)
return;
/* stop here if we reached the end of data */
if (conn_data_read0_pending(conn))
goto out_shutdown_r;
/* maybe we were called immediately after an asynchronous shutr */
if (chn->flags & CF_SHUTR)
return;
cur_read = 0;
if ((chn->flags & (CF_STREAMER | CF_STREAMER_FAST)) && !chn->buf->o &&
global.tune.idle_timer &&
(unsigned short)(now_ms - chn->last_read) >= global.tune.idle_timer) {
/* The buffer was empty and nothing was transferred for more
* than one second. This was caused by a pause and not by
* congestion. Reset any streaming mode to reduce latency.
*/
chn->xfer_small = 0;
chn->xfer_large = 0;
chn->flags &= ~(CF_STREAMER | CF_STREAMER_FAST);
}
/* First, let's see if we may splice data across the channel without
* using a buffer.
*/
if (conn->xprt->rcv_pipe &&
(chn->pipe || chn->to_forward >= MIN_SPLICE_FORWARD) &&
chn->flags & CF_KERN_SPLICING) {
if (buffer_not_empty(chn->buf)) {
/* 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.
*/
goto abort_splice;
}
if (unlikely(chn->pipe == NULL)) {
if (pipes_used >= global.maxpipes || !(chn->pipe = get_pipe())) {
chn->flags &= ~CF_KERN_SPLICING;
goto abort_splice;
}
}
ret = conn->xprt->rcv_pipe(conn, chn->pipe, chn->to_forward);
if (ret < 0) {
/* splice not supported on this end, let's disable it */
chn->flags &= ~CF_KERN_SPLICING;
goto abort_splice;
}
if (ret > 0) {
if (chn->to_forward != CHN_INFINITE_FORWARD)
chn->to_forward -= ret;
chn->total += ret;
cur_read += ret;
chn->flags |= CF_READ_PARTIAL;
}
if (conn_data_read0_pending(conn))
goto out_shutdown_r;
if (conn->flags & CO_FL_ERROR)
return;
if (conn->flags & CO_FL_WAIT_ROOM) {
/* the pipe is full or we have read enough data that it
* could soon be full. Let's stop before needing to poll.
*/
si->flags |= SI_FL_WAIT_ROOM;
__conn_data_stop_recv(conn);
}
/* splice not possible (anymore), let's go on on standard copy */
}
abort_splice:
if (chn->pipe && unlikely(!chn->pipe->data)) {
put_pipe(chn->pipe);
chn->pipe = NULL;
}
/* Important note : if we're called with POLL_IN|POLL_HUP, it means the read polling
* was enabled, which implies that the recv buffer was not full. So we have a guarantee
* that if such an event is not handled above in splice, it will be handled here by
* recv().
*/
while (!(conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_DATA_RD_SH | CO_FL_WAIT_ROOM | CO_FL_HANDSHAKE))) {
max = bi_avail(chn);
if (!max) {
si->flags |= SI_FL_WAIT_ROOM;
break;
}
ret = conn->xprt->rcv_buf(conn, chn->buf, max);
if (ret <= 0)
break;
cur_read += ret;
/* if we're allowed to directly forward data, we must update ->o */
if (chn->to_forward && !(chn->flags & (CF_SHUTW|CF_SHUTW_NOW))) {
unsigned long fwd = ret;
if (chn->to_forward != CHN_INFINITE_FORWARD) {
if (fwd > chn->to_forward)
fwd = chn->to_forward;
chn->to_forward -= fwd;
}
b_adv(chn->buf, fwd);
}
chn->flags |= CF_READ_PARTIAL;
chn->total += ret;
if (channel_full(chn)) {
si->flags |= SI_FL_WAIT_ROOM;
break;
}
if ((chn->flags & CF_READ_DONTWAIT) || --read_poll <= 0) {
si->flags |= SI_FL_WAIT_ROOM;
__conn_data_stop_recv(conn);
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.
*/
if (ret < max) {
/* if a streamer has read few data, it may be because we
* have exhausted system buffers. It's not worth trying
* again.
*/
if (chn->flags & CF_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;
}
} /* while !flags */
if (conn->flags & CO_FL_ERROR)
return;
if (cur_read) {
if ((chn->flags & (CF_STREAMER | CF_STREAMER_FAST)) &&
(cur_read <= chn->buf->size / 2)) {
chn->xfer_large = 0;
chn->xfer_small++;
if (chn->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.
*/
chn->flags &= ~(CF_STREAMER | CF_STREAMER_FAST);
}
else if (chn->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".
*/
chn->flags &= ~CF_STREAMER_FAST;
}
}
else if (!(chn->flags & CF_STREAMER_FAST) &&
(cur_read >= chn->buf->size - global.tune.maxrewrite)) {
/* we read a full buffer at once */
chn->xfer_small = 0;
chn->xfer_large++;
if (chn->xfer_large >= 3) {
/* we call this buffer a fast streamer if it manages
* to be filled in one call 3 consecutive times.
*/
chn->flags |= (CF_STREAMER | CF_STREAMER_FAST);
}
}
else {
chn->xfer_small = 0;
chn->xfer_large = 0;
}
chn->last_read = now_ms;
}
if (conn_data_read0_pending(conn))
/* connection closed */
goto out_shutdown_r;
return;
out_shutdown_r:
/* we received a shutdown */
chn->flags |= CF_READ_NULL;
if (chn->flags & CF_AUTO_CLOSE)
channel_shutw_now(chn);
stream_sock_read0(si);
conn_data_read0(conn);
return;
}
/*
* This is the callback which is called by the connection layer to send data
* from the buffer to the connection. It iterates over the transport layer's
* snd_buf function.
*/
static void si_conn_send_cb(struct connection *conn)
{
struct stream_interface *si = conn->owner;
struct channel *chn = si->ob;
if (conn->flags & CO_FL_ERROR)
return;
if (conn->flags & CO_FL_HANDSHAKE)
/* a handshake was requested */
return;
/* we might have been called just after an asynchronous shutw */
if (chn->flags & CF_SHUTW)
return;
/* OK there are data waiting to be sent */
si_conn_send(conn);
/* OK all done */
return;
}
/*
* This function propagates a null read received on a socket-based connection.
* It updates the stream interface. If the stream interface has SI_FL_NOHALF,
* the close is also forwarded to the write side as an abort. This function is
* still socket-specific as it handles a setsockopt() call to set the SO_LINGER
* state on the socket.
*/
void stream_sock_read0(struct stream_interface *si)
{
struct connection *conn = __objt_conn(si->end);
si->ib->flags &= ~CF_SHUTR_NOW;
if (si->ib->flags & CF_SHUTR)
return;
si->ib->flags |= CF_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 & CF_SHUTW)
goto do_close;
if (si->flags & SI_FL_NOHALF) {
/* we want to immediately forward this close to the write side */
/* force flag on ssl to keep session in cache */
if (conn->xprt->shutw)
conn->xprt->shutw(conn, 0);
goto do_close;
}
/* otherwise that's just a normal read shutdown */
if (conn_ctrl_ready(conn))
fdtab[conn->t.sock.fd].linger_risk = 0;
__conn_data_stop_recv(conn);
return;
do_close:
/* OK we completely close the socket here just as if we went through si_shut[rw]() */
conn_full_close(conn);
si->ib->flags &= ~CF_SHUTR_NOW;
si->ib->flags |= CF_SHUTR;
si->ib->rex = TICK_ETERNITY;
si->ob->flags &= ~CF_SHUTW_NOW;
si->ob->flags |= CF_SHUTW;
si->ob->wex = TICK_ETERNITY;
si->flags &= ~(SI_FL_WAIT_DATA | SI_FL_WAIT_ROOM);
si->state = SI_ST_DIS;
si->exp = TICK_ETERNITY;
return;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/