haproxy/include/proto/stream.h
Christopher Faulet a73e59b690 BUG/MAJOR: Fix how the list of entities waiting for a buffer is handled
When an entity tries to get a buffer, if it cannot be allocted, for example
because the number of buffers which may be allocated per process is limited,
this entity is added in a list (called <buffer_wq>) and wait for an available
buffer.

Historically, the <buffer_wq> list was logically attached to streams because it
were the only entities likely to be added in it. Now, applets can also be
waiting for a free buffer. And with filters, we could imagine to have more other
entities waiting for a buffer. So it make sense to have a generic list.

Anyway, with the current design there is a bug. When an applet failed to get a
buffer, it will wait. But we add the stream attached to the applet in
<buffer_wq>, instead of the applet itself. So when a buffer is available, we
wake up the stream and not the waiting applet. So, it is possible to have
waiting applets and never awakened.

So, now, <buffer_wq> is independant from streams. And we really add the waiting
entity in <buffer_wq>. To be generic, the entity is responsible to define the
callback used to awaken it.

In addition, applets will still request an input buffer when they become
active. But they will not be sleeped anymore if no buffer are available. So this
is the responsibility to the applet I/O handler to check if this buffer is
allocated or not. This way, an applet can decide if this buffer is required or
not and can do additional processing if not.

[wt: backport to 1.7 and 1.6]
2016-12-12 19:11:04 +01:00

305 lines
9.1 KiB
C

/*
* include/proto/stream.h
* This file defines everything related to streams.
*
* Copyright (C) 2000-2010 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _PROTO_STREAM_H
#define _PROTO_STREAM_H
#include <common/config.h>
#include <common/memory.h>
#include <types/stream.h>
#include <proto/fd.h>
#include <proto/freq_ctr.h>
#include <proto/stick_table.h>
#include <proto/task.h>
extern struct pool_head *pool2_stream;
extern struct list streams;
extern struct data_cb sess_conn_cb;
struct stream *stream_new(struct session *sess, struct task *t, enum obj_type *origin);
/* perform minimal intializations, report 0 in case of error, 1 if OK. */
int init_stream();
/* kill a stream and set the termination flags to <why> (one of SF_ERR_*) */
void stream_shutdown(struct stream *stream, int why);
void stream_process_counters(struct stream *s);
void sess_change_server(struct stream *sess, struct server *newsrv);
struct task *process_stream(struct task *t);
void default_srv_error(struct stream *s, struct stream_interface *si);
int parse_track_counters(char **args, int *arg,
int section_type, struct proxy *curpx,
struct track_ctr_prm *prm,
struct proxy *defpx, char **err);
/* Update the stream's backend and server time stats */
void stream_update_time_stats(struct stream *s);
void stream_release_buffers(struct stream *s);
/* returns the session this stream belongs to */
static inline struct session *strm_sess(const struct stream *strm)
{
return strm->sess;
}
/* returns the frontend this stream was initiated from */
static inline struct proxy *strm_fe(const struct stream *strm)
{
return strm->sess->fe;
}
/* returns the listener this stream was initiated from */
static inline struct listener *strm_li(const struct stream *strm)
{
return strm->sess->listener;
}
/* returns a pointer to the origin of the session which created this stream */
static inline enum obj_type *strm_orig(const struct stream *strm)
{
return strm->sess->origin;
}
/* Remove the refcount from the stream to the tracked counters, and clear the
* pointer to ensure this is only performed once. The caller is responsible for
* ensuring that the pointer is valid first. We must be extremely careful not
* to touch the entries we inherited from the session.
*/
static inline void stream_store_counters(struct stream *s)
{
void *ptr;
int i;
for (i = 0; i < MAX_SESS_STKCTR; i++) {
if (!stkctr_entry(&s->stkctr[i]))
continue;
if (stkctr_entry(&s->sess->stkctr[i]))
continue;
ptr = stktable_data_ptr(s->stkctr[i].table, stkctr_entry(&s->stkctr[i]), STKTABLE_DT_CONN_CUR);
if (ptr)
stktable_data_cast(ptr, conn_cur)--;
stkctr_entry(&s->stkctr[i])->ref_cnt--;
stksess_kill_if_expired(s->stkctr[i].table, stkctr_entry(&s->stkctr[i]));
stkctr_set_entry(&s->stkctr[i], NULL);
}
}
/* Remove the refcount from the stream counters tracked at the content level if
* any, and clear the pointer to ensure this is only performed once. The caller
* is responsible for ensuring that the pointer is valid first. We must be
* extremely careful not to touch the entries we inherited from the session.
*/
static inline void stream_stop_content_counters(struct stream *s)
{
void *ptr;
int i;
for (i = 0; i < MAX_SESS_STKCTR; i++) {
if (!stkctr_entry(&s->stkctr[i]))
continue;
if (stkctr_entry(&s->sess->stkctr[i]))
continue;
if (!(stkctr_flags(&s->stkctr[i]) & STKCTR_TRACK_CONTENT))
continue;
ptr = stktable_data_ptr(s->stkctr[i].table, stkctr_entry(&s->stkctr[i]), STKTABLE_DT_CONN_CUR);
if (ptr)
stktable_data_cast(ptr, conn_cur)--;
stkctr_entry(&s->stkctr[i])->ref_cnt--;
stksess_kill_if_expired(s->stkctr[i].table, stkctr_entry(&s->stkctr[i]));
stkctr_set_entry(&s->stkctr[i], NULL);
}
}
/* Increase total and concurrent connection count for stick entry <ts> of table
* <t>. The caller is responsible for ensuring that <t> and <ts> are valid
* pointers, and for calling this only once per connection.
*/
static inline void stream_start_counters(struct stktable *t, struct stksess *ts)
{
void *ptr;
ptr = stktable_data_ptr(t, ts, STKTABLE_DT_CONN_CUR);
if (ptr)
stktable_data_cast(ptr, conn_cur)++;
ptr = stktable_data_ptr(t, ts, STKTABLE_DT_CONN_CNT);
if (ptr)
stktable_data_cast(ptr, conn_cnt)++;
ptr = stktable_data_ptr(t, ts, STKTABLE_DT_CONN_RATE);
if (ptr)
update_freq_ctr_period(&stktable_data_cast(ptr, conn_rate),
t->data_arg[STKTABLE_DT_CONN_RATE].u, 1);
if (tick_isset(t->expire))
ts->expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
}
/* Enable tracking of stream counters as <stkctr> on stksess <ts>. The caller is
* responsible for ensuring that <t> and <ts> are valid pointers. Some controls
* are performed to ensure the state can still change.
*/
static inline void stream_track_stkctr(struct stkctr *ctr, struct stktable *t, struct stksess *ts)
{
if (stkctr_entry(ctr))
return;
ts->ref_cnt++;
ctr->table = t;
stkctr_set_entry(ctr, ts);
stream_start_counters(t, ts);
}
/* Increase the number of cumulated HTTP requests in the tracked counters */
static void inline stream_inc_http_req_ctr(struct stream *s)
{
void *ptr;
int i;
for (i = 0; i < MAX_SESS_STKCTR; i++) {
struct stkctr *stkctr = &s->stkctr[i];
if (!stkctr_entry(stkctr)) {
stkctr = &s->sess->stkctr[i];
if (!stkctr_entry(stkctr))
continue;
}
ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_HTTP_REQ_CNT);
if (ptr)
stktable_data_cast(ptr, http_req_cnt)++;
ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_HTTP_REQ_RATE);
if (ptr)
update_freq_ctr_period(&stktable_data_cast(ptr, http_req_rate),
stkctr->table->data_arg[STKTABLE_DT_HTTP_REQ_RATE].u, 1);
}
}
/* Increase the number of cumulated HTTP requests in the backend's tracked
* counters. We don't look up the session since it cannot happen in the bakcend.
*/
static void inline stream_inc_be_http_req_ctr(struct stream *s)
{
void *ptr;
int i;
for (i = 0; i < MAX_SESS_STKCTR; i++) {
struct stkctr *stkctr = &s->stkctr[i];
if (!stkctr_entry(stkctr))
continue;
if (!(stkctr_flags(&s->stkctr[i]) & STKCTR_TRACK_BACKEND))
continue;
ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_HTTP_REQ_CNT);
if (ptr)
stktable_data_cast(ptr, http_req_cnt)++;
ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_HTTP_REQ_RATE);
if (ptr)
update_freq_ctr_period(&stktable_data_cast(ptr, http_req_rate),
stkctr->table->data_arg[STKTABLE_DT_HTTP_REQ_RATE].u, 1);
}
}
/* Increase the number of cumulated failed HTTP requests in the tracked
* counters. Only 4xx requests should be counted here so that we can
* distinguish between errors caused by client behaviour and other ones.
* Note that even 404 are interesting because they're generally caused by
* vulnerability scans.
*/
static void inline stream_inc_http_err_ctr(struct stream *s)
{
void *ptr;
int i;
for (i = 0; i < MAX_SESS_STKCTR; i++) {
struct stkctr *stkctr = &s->stkctr[i];
if (!stkctr_entry(stkctr)) {
stkctr = &s->sess->stkctr[i];
if (!stkctr_entry(stkctr))
continue;
}
ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_HTTP_ERR_CNT);
if (ptr)
stktable_data_cast(ptr, http_err_cnt)++;
ptr = stktable_data_ptr(stkctr->table, stkctr_entry(stkctr), STKTABLE_DT_HTTP_ERR_RATE);
if (ptr)
update_freq_ctr_period(&stktable_data_cast(ptr, http_err_rate),
stkctr->table->data_arg[STKTABLE_DT_HTTP_ERR_RATE].u, 1);
}
}
static void inline stream_add_srv_conn(struct stream *sess, struct server *srv)
{
sess->srv_conn = srv;
LIST_ADD(&srv->actconns, &sess->by_srv);
}
static void inline stream_del_srv_conn(struct stream *sess)
{
if (!sess->srv_conn)
return;
sess->srv_conn = NULL;
LIST_DEL(&sess->by_srv);
}
static void inline stream_init_srv_conn(struct stream *sess)
{
sess->srv_conn = NULL;
LIST_INIT(&sess->by_srv);
}
/* Callback used to wake up a stream when a buffer is available. The stream <s>
* is woken up is if it is not already running and if it is not already in the
* task run queue. This functions returns 1 is the stream is woken up, otherwise
* it returns 0. */
static int inline stream_res_wakeup(struct stream *s)
{
if (s->task->state & TASK_RUNNING || task_in_rq(s->task))
return 0;
task_wakeup(s->task, TASK_WOKEN_RES);
return 1;
}
void service_keywords_register(struct action_kw_list *kw_list);
#endif /* _PROTO_STREAM_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/