haproxy/src/queue.c
Willy Tarreau 7867cebf31 BUG/MAJOR: queue: set SF_ASSIGNED when setting strm->target on dequeue
Commit 82cd5c13a ("OPTIM: backend: skip LB when we know the backend is
full") has uncovered a long-burried bug in the dequeing code: when a
server releases a connection, it picks a new one from the proxy's or
its queue. Technically speaking it only picks a pendconn which is a
link between a position in the queue and a stream. It then sets this
pendconn's target to itself, and wakes up the stream's task so that
it can try to connect again.

The stream then goes through the regular connection setup phases,
calls back_try_conn_req() which calls pendconn_dequeue(), which
sets the stream's target to the pendconn's and releases the pendconn.
It then reaches assign_server() which sees no SF_ASSIGNED and calls
assign_server_and_queue() to perform load balancing or queuing. This
one first destroys the stream's target and gets ready to perform load
balancing. At this point we're load-balancing for no reason since we
already knew what server was available. And this is where the commit
above comes into play: the check for the backend's queue above may
detect other connections that arrived in between, and will immediately
return FULL, forcing this request back into the queue. If the server
had a very low maxconn (e.g. 1 due to a long slowstart), it's possible
that this evicted connection was the last one on the server and that
no other one will ever be present to process the queue. Usually a
regularly processed request will still have its own srv_conn that will
be used during stream_free() to dequeue other connections. But if the
server had a down-up cycle, then a call to pendconn_grab_from_px()
may start to dequeue entries which had no srv_conn and which will have
no server slot to offer when they expire, thus maintaining the situation
above forever. Worse, as new requests arrive, there are always some
requests in the queue and the situation feeds on itself.

The correct fix here is to properly set SF_ASSIGNED in pendconn_dequeue()
when the stream's target is assigned (as it's what this flag means), so
as to avoid a load-balancing pass when dequeuing.

Many thanks to Pierre Cheynier for the numerous detailed traces he
provided that helped narrow this problem down.

This could be backported to all stable versions, but in practice only
2.3 and above are really affected since the presence of the commit
above. Given how tricky this code is it's better to limit it to those
versions that really need it.
2021-06-16 09:05:35 +02:00

710 lines
23 KiB
C

/*
* Queue management functions.
*
* 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.
*
*/
/* Short explanation on the locking, which is far from being trivial : a
* pendconn is a list element which necessarily is associated with an existing
* stream. It has pendconn->strm always valid. A pendconn may only be in one of
* these three states :
* - unlinked : in this case it is an empty list head ;
* - linked into the server's queue ;
* - linked into the proxy's queue.
*
* A stream does not necessarily have such a pendconn. Thus the pendconn is
* designated by the stream->pend_pos pointer. This results in some properties :
* - pendconn->strm->pend_pos is never NULL for any valid pendconn
* - if p->node.node.leaf_p is NULL, the element is unlinked,
* otherwise it necessarily belongs to one of the other lists ; this may
* not be atomically checked under threads though ;
* - pendconn->px is never NULL if pendconn->list is not empty
* - pendconn->srv is never NULL if pendconn->list is in the server's queue,
* and is always NULL if pendconn->list is in the backend's queue or empty.
* - pendconn->target is NULL while the element is queued, and points to the
* assigned server when the pendconn is picked.
*
* Threads complicate the design a little bit but rules remain simple :
* - the server's queue lock must be held at least when manipulating the
* server's queue, which is when adding a pendconn to the queue and when
* removing a pendconn from the queue. It protects the queue's integrity.
*
* - the proxy's queue lock must be held at least when manipulating the
* proxy's queue, which is when adding a pendconn to the queue and when
* removing a pendconn from the queue. It protects the queue's integrity.
*
* - both locks are compatible and may be held at the same time.
*
* - a pendconn_add() is only performed by the stream which will own the
* pendconn ; the pendconn is allocated at this moment and returned ; it is
* added to either the server or the proxy's queue while holding this
s * queue's lock.
*
* - the pendconn is then met by a thread walking over the proxy or server's
* queue with the respective lock held. This lock is exclusive and the
* pendconn can only appear in one queue so by definition a single thread
* may find this pendconn at a time.
*
* - the pendconn is unlinked either by its own stream upon success/abort/
* free, or by another one offering it its server slot. This is achieved by
* pendconn_process_next_strm() under either the server or proxy's lock,
* pendconn_redistribute() under the server's lock, pendconn_grab_from_px()
* under the proxy's lock, or pendconn_unlink() under either the proxy's or
* the server's lock depending on the queue the pendconn is attached to.
*
* - no single operation except the pendconn initialisation prior to the
* insertion are performed without eithre a queue lock held or the element
* being unlinked and visible exclusively to its stream.
*
* - pendconn_grab_from_px() and pendconn_process_next_strm() assign ->target
* so that the stream knows what server to work with (via
* pendconn_dequeue() which sets it on strm->target).
*
* - a pendconn doesn't switch between queues, it stays where it is.
*/
#include <import/eb32tree.h>
#include <haproxy/api.h>
#include <haproxy/backend.h>
#include <haproxy/http_rules.h>
#include <haproxy/pool.h>
#include <haproxy/queue.h>
#include <haproxy/sample.h>
#include <haproxy/server-t.h>
#include <haproxy/stream.h>
#include <haproxy/stream_interface.h>
#include <haproxy/task.h>
#include <haproxy/tcp_rules.h>
#include <haproxy/thread.h>
#include <haproxy/time.h>
#include <haproxy/tools.h>
#define NOW_OFFSET_BOUNDARY() ((now_ms - (TIMER_LOOK_BACK >> 12)) & 0xfffff)
#define KEY_CLASS(key) ((u32)key & 0xfff00000)
#define KEY_OFFSET(key) ((u32)key & 0x000fffff)
#define KEY_CLASS_OFFSET_BOUNDARY(key) (KEY_CLASS(key) | NOW_OFFSET_BOUNDARY())
#define MAKE_KEY(class, offset) (((u32)(class + 0x7ff) << 20) | ((u32)(now_ms + offset) & 0xfffff))
DECLARE_POOL(pool_head_pendconn, "pendconn", sizeof(struct pendconn));
/* returns the effective dynamic maxconn for a server, considering the minconn
* and the proxy's usage relative to its dynamic connections limit. It is
* expected that 0 < s->minconn <= s->maxconn when this is called. If the
* server is currently warming up, the slowstart is also applied to the
* resulting value, which can be lower than minconn in this case, but never
* less than 1.
*/
unsigned int srv_dynamic_maxconn(const struct server *s)
{
unsigned int max;
if (s->proxy->beconn >= s->proxy->fullconn)
/* no fullconn or proxy is full */
max = s->maxconn;
else if (s->minconn == s->maxconn)
/* static limit */
max = s->maxconn;
else max = MAX(s->minconn,
s->proxy->beconn * s->maxconn / s->proxy->fullconn);
if ((s->cur_state == SRV_ST_STARTING) &&
now.tv_sec < s->last_change + s->slowstart &&
now.tv_sec >= s->last_change) {
unsigned int ratio;
ratio = 100 * (now.tv_sec - s->last_change) / s->slowstart;
max = MAX(1, max * ratio / 100);
}
return max;
}
/* Remove the pendconn from the server's queue. At this stage, the connection
* is not really dequeued. It will be done during the process_stream. It is
* up to the caller to atomically decrement the pending counts.
*
* The caller must own the lock on the server queue. The pendconn must still be
* queued (p->node.leaf_p != NULL) and must be in a server (p->srv != NULL).
*/
static void __pendconn_unlink_srv(struct pendconn *p)
{
p->strm->logs.srv_queue_pos += p->srv->queue_idx - p->queue_idx;
eb32_delete(&p->node);
}
/* Remove the pendconn from the proxy's queue. At this stage, the connection
* is not really dequeued. It will be done during the process_stream. It is
* up to the caller to atomically decrement the pending counts.
*
* The caller must own the lock on the proxy queue. The pendconn must still be
* queued (p->node.leaf_p != NULL) and must be in the proxy (p->srv == NULL).
*/
static void __pendconn_unlink_prx(struct pendconn *p)
{
p->strm->logs.prx_queue_pos += p->px->queue_idx - p->queue_idx;
eb32_delete(&p->node);
}
/* Locks the queue the pendconn element belongs to. This relies on both p->px
* and p->srv to be properly initialized (which is always the case once the
* element has been added).
*/
static inline void pendconn_queue_lock(struct pendconn *p)
{
if (p->srv)
HA_SPIN_LOCK(SERVER_LOCK, &p->srv->lock);
else
HA_RWLOCK_WRLOCK(PROXY_LOCK, &p->px->lock);
}
/* Unlocks the queue the pendconn element belongs to. This relies on both p->px
* and p->srv to be properly initialized (which is always the case once the
* element has been added).
*/
static inline void pendconn_queue_unlock(struct pendconn *p)
{
if (p->srv)
HA_SPIN_UNLOCK(SERVER_LOCK, &p->srv->lock);
else
HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &p->px->lock);
}
/* Removes the pendconn from the server/proxy queue. At this stage, the
* connection is not really dequeued. It will be done during process_stream().
* This function takes all the required locks for the operation. The pendconn
* must be valid, though it doesn't matter if it was already unlinked. Prefer
* pendconn_cond_unlink() to first check <p>. When the locks are already held,
* please use __pendconn_unlink_{srv,prx}() instead.
*/
void pendconn_unlink(struct pendconn *p)
{
int done = 0;
if (p->srv) {
/* queued in the server */
HA_SPIN_LOCK(SERVER_LOCK, &p->srv->lock);
if (p->node.node.leaf_p) {
__pendconn_unlink_srv(p);
done = 1;
}
HA_SPIN_UNLOCK(SERVER_LOCK, &p->srv->lock);
if (done) {
_HA_ATOMIC_DEC(&p->srv->nbpend);
_HA_ATOMIC_DEC(&p->px->totpend);
}
}
else {
/* queued in the proxy */
HA_RWLOCK_WRLOCK(PROXY_LOCK, &p->px->lock);
if (p->node.node.leaf_p) {
__pendconn_unlink_prx(p);
done = 1;
}
HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &p->px->lock);
if (done) {
_HA_ATOMIC_DEC(&p->px->nbpend);
_HA_ATOMIC_DEC(&p->px->totpend);
}
}
}
/* Retrieve the first pendconn from tree <pendconns>. Classes are always
* considered first, then the time offset. The time does wrap, so the
* lookup is performed twice, one to retrieve the first class and a second
* time to retrieve the earliest time in this class.
*/
static struct pendconn *pendconn_first(struct eb_root *pendconns)
{
struct eb32_node *node, *node2 = NULL;
u32 key;
node = eb32_first(pendconns);
if (!node)
return NULL;
key = KEY_CLASS_OFFSET_BOUNDARY(node->key);
node2 = eb32_lookup_ge(pendconns, key);
if (!node2 ||
KEY_CLASS(node2->key) != KEY_CLASS(node->key)) {
/* no other key in the tree, or in this class */
return eb32_entry(node, struct pendconn, node);
}
/* found a better key */
return eb32_entry(node2, struct pendconn, node);
}
/* Process the next pending connection from either a server or a proxy, and
* returns a strictly positive value on success (see below). If no pending
* connection is found, 0 is returned. Note that neither <srv> nor <px> may be
* NULL. Priority is given to the oldest request in the queue if both <srv> and
* <px> have pending requests. This ensures that no request will be left
* unserved. The <px> queue is not considered if the server (or a tracked
* server) is not RUNNING, is disabled, or has a null weight (server going
* down). The <srv> queue is still considered in this case, because if some
* connections remain there, it means that some requests have been forced there
* after it was seen down (eg: due to option persist). The stream is
* immediately marked as "assigned", and both its <srv> and <srv_conn> are set
* to <srv>.
*
* This function must only be called if the server queue _AND_ the proxy queue
* are locked. Today it is only called by process_srv_queue. When a pending
* connection is dequeued, this function returns 1 if the pending connection can
* be handled by the current thread, else it returns 2.
*/
static int pendconn_process_next_strm(struct server *srv, struct proxy *px)
{
struct pendconn *p = NULL;
struct pendconn *pp = NULL;
struct server *rsrv;
u32 pkey, ppkey;
rsrv = srv->track;
if (!rsrv)
rsrv = srv;
p = NULL;
if (srv->nbpend)
p = pendconn_first(&srv->pendconns);
pp = NULL;
if (srv_currently_usable(rsrv) && px->nbpend &&
(!(srv->flags & SRV_F_BACKUP) ||
(!px->srv_act &&
(srv == px->lbprm.fbck || (px->options & PR_O_USE_ALL_BK)))))
pp = pendconn_first(&px->pendconns);
if (!p && !pp)
return 0;
else if (!pp)
goto use_p; /* p != NULL */
else if (!p)
goto use_pp; /* pp != NULL */
/* p != NULL && pp != NULL*/
if (KEY_CLASS(p->node.key) < KEY_CLASS(pp->node.key))
goto use_p;
if (KEY_CLASS(pp->node.key) < KEY_CLASS(p->node.key))
goto use_pp;
pkey = KEY_OFFSET(p->node.key);
ppkey = KEY_OFFSET(pp->node.key);
if (pkey < NOW_OFFSET_BOUNDARY())
pkey += 0x100000; // key in the future
if (ppkey < NOW_OFFSET_BOUNDARY())
ppkey += 0x100000; // key in the future
if (pkey <= ppkey)
goto use_p;
use_pp:
/* Let's switch from the server pendconn to the proxy pendconn */
__pendconn_unlink_prx(pp);
_HA_ATOMIC_DEC(&px->nbpend);
_HA_ATOMIC_DEC(&px->totpend);
px->queue_idx++;
p = pp;
goto unlinked;
use_p:
__pendconn_unlink_srv(p);
_HA_ATOMIC_DEC(&srv->nbpend);
_HA_ATOMIC_DEC(&px->totpend);
srv->queue_idx++;
unlinked:
p->strm_flags |= SF_ASSIGNED;
p->target = srv;
_HA_ATOMIC_INC(&srv->served);
_HA_ATOMIC_INC(&srv->proxy->served);
__ha_barrier_atomic_store();
if (px->lbprm.server_take_conn)
px->lbprm.server_take_conn(srv, 1);
stream_add_srv_conn(p->strm, srv);
task_wakeup(p->strm->task, TASK_WOKEN_RES);
return 1;
}
/* Manages a server's connection queue. This function will try to dequeue as
* many pending streams as possible, and wake them up.
*/
void process_srv_queue(struct server *s)
{
struct proxy *p = s->proxy;
int maxconn;
HA_SPIN_LOCK(SERVER_LOCK, &s->lock);
HA_RWLOCK_WRLOCK(PROXY_LOCK, &p->lock);
maxconn = srv_dynamic_maxconn(s);
while (s->served < maxconn) {
int ret = pendconn_process_next_strm(s, p);
if (!ret)
break;
}
HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &p->lock);
HA_SPIN_UNLOCK(SERVER_LOCK, &s->lock);
}
/* Adds the stream <strm> to the pending connection queue of server <strm>->srv
* or to the one of <strm>->proxy if srv is NULL. All counters and back pointers
* are updated accordingly. Returns NULL if no memory is available, otherwise the
* pendconn itself. If the stream was already marked as served, its flag is
* cleared. It is illegal to call this function with a non-NULL strm->srv_conn.
* The stream's queue position is counted with an offset of -1 because we want
* to make sure that being at the first position in the queue reports 1.
*
* The queue is sorted by the composition of the priority_class, and the current
* timestamp offset by strm->priority_offset. The timestamp is in milliseconds
* and truncated to 20 bits, so will wrap every 17m28s575ms.
* The offset can be positive or negative, and an offset of 0 puts it in the
* middle of this range (~ 8 min). Note that this also means if the adjusted
* timestamp wraps around, the request will be misinterpreted as being of
* the highest priority for that priority class.
*
* This function must be called by the stream itself, so in the context of
* process_stream.
*/
struct pendconn *pendconn_add(struct stream *strm)
{
struct pendconn *p;
struct proxy *px;
struct server *srv;
p = pool_alloc(pool_head_pendconn);
if (!p)
return NULL;
if (strm->flags & SF_ASSIGNED)
srv = objt_server(strm->target);
else
srv = NULL;
px = strm->be;
p->target = NULL;
p->srv = srv;
p->node.key = MAKE_KEY(strm->priority_class, strm->priority_offset);
p->px = px;
p->strm = strm;
p->strm_flags = strm->flags;
if (srv) {
unsigned int old_max, new_max;
new_max = _HA_ATOMIC_ADD_FETCH(&srv->nbpend, 1);
old_max = srv->counters.nbpend_max;
while (new_max > old_max) {
if (likely(_HA_ATOMIC_CAS(&srv->counters.nbpend_max, &old_max, new_max)))
break;
}
__ha_barrier_atomic_store();
HA_SPIN_LOCK(SERVER_LOCK, &p->srv->lock);
p->queue_idx = srv->queue_idx - 1; // for increment
eb32_insert(&srv->pendconns, &p->node);
HA_SPIN_UNLOCK(SERVER_LOCK, &p->srv->lock);
}
else {
unsigned int old_max, new_max;
new_max = _HA_ATOMIC_ADD_FETCH(&px->nbpend, 1);
old_max = px->be_counters.nbpend_max;
while (new_max > old_max) {
if (likely(_HA_ATOMIC_CAS(&px->be_counters.nbpend_max, &old_max, new_max)))
break;
}
__ha_barrier_atomic_store();
HA_RWLOCK_WRLOCK(PROXY_LOCK, &p->px->lock);
p->queue_idx = px->queue_idx - 1; // for increment
eb32_insert(&px->pendconns, &p->node);
HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &p->px->lock);
}
strm->pend_pos = p;
_HA_ATOMIC_INC(&px->totpend);
return p;
}
/* Redistribute pending connections when a server goes down. The number of
* connections redistributed is returned. It must be called with the server
* lock held.
*/
int pendconn_redistribute(struct server *s)
{
struct pendconn *p;
struct eb32_node *node, *nodeb;
int xferred = 0;
/* The REDISP option was specified. We will ignore cookie and force to
* balance or use the dispatcher. */
if ((s->proxy->options & (PR_O_REDISP|PR_O_PERSIST)) != PR_O_REDISP)
return 0;
for (node = eb32_first(&s->pendconns); node; node = nodeb) {
nodeb = eb32_next(node);
p = eb32_entry(node, struct pendconn, node);
if (p->strm_flags & SF_FORCE_PRST)
continue;
/* it's left to the dispatcher to choose a server */
__pendconn_unlink_srv(p);
p->strm_flags &= ~(SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
task_wakeup(p->strm->task, TASK_WOKEN_RES);
xferred++;
}
if (xferred) {
_HA_ATOMIC_SUB(&s->nbpend, xferred);
_HA_ATOMIC_SUB(&s->proxy->totpend, xferred);
}
return xferred;
}
/* Check for pending connections at the backend, and assign some of them to
* the server coming up. The server's weight is checked before being assigned
* connections it may not be able to handle. The total number of transferred
* connections is returned. It must be called with the server lock held, and
* will take the proxy's lock.
*/
int pendconn_grab_from_px(struct server *s)
{
struct pendconn *p;
int maxconn, xferred = 0;
if (!srv_currently_usable(s))
return 0;
/* if this is a backup server and there are active servers or at
* least another backup server was elected, then this one must
* not dequeue requests from the proxy.
*/
if ((s->flags & SRV_F_BACKUP) &&
(s->proxy->srv_act ||
((s != s->proxy->lbprm.fbck) && !(s->proxy->options & PR_O_USE_ALL_BK))))
return 0;
HA_RWLOCK_WRLOCK(PROXY_LOCK, &s->proxy->lock);
maxconn = srv_dynamic_maxconn(s);
while ((p = pendconn_first(&s->proxy->pendconns))) {
if (s->maxconn && s->served + xferred >= maxconn)
break;
__pendconn_unlink_prx(p);
p->target = s;
task_wakeup(p->strm->task, TASK_WOKEN_RES);
xferred++;
}
HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &s->proxy->lock);
if (xferred) {
_HA_ATOMIC_SUB(&s->proxy->nbpend, xferred);
_HA_ATOMIC_SUB(&s->proxy->totpend, xferred);
}
return xferred;
}
/* Try to dequeue pending connection attached to the stream <strm>. It must
* always exists here. If the pendconn is still linked to the server or the
* proxy queue, nothing is done and the function returns 1. Otherwise,
* <strm>->flags and <strm>->target are updated, the pendconn is released and 0
* is returned.
*
* This function must be called by the stream itself, so in the context of
* process_stream.
*/
int pendconn_dequeue(struct stream *strm)
{
struct pendconn *p;
int is_unlinked;
if (unlikely(!strm->pend_pos)) {
/* unexpected case because it is called by the stream itself and
* only the stream can release a pendconn. So it is only
* possible if a pendconn is released by someone else or if the
* stream is supposed to be queued but without its associated
* pendconn. In both cases it is a bug! */
abort();
}
p = strm->pend_pos;
/* note below : we need to grab the queue's lock to check for emptiness
* because we don't want a partial _grab_from_px() or _redistribute()
* to be called in parallel and show an empty list without having the
* time to finish. With this we know that if we see the element
* unlinked, these functions were completely done.
*/
pendconn_queue_lock(p);
is_unlinked = !p->node.node.leaf_p;
pendconn_queue_unlock(p);
if (!is_unlinked)
return 1;
/* the pendconn is not queued anymore and will not be so we're safe
* to proceed.
*/
strm->flags &= ~(SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
strm->flags |= p->strm_flags & (SF_DIRECT | SF_ASSIGNED | SF_ADDR_SET);
if (p->target) {
/* a server picked this pendconn, it must skip LB */
strm->target = &p->target->obj_type;
strm->flags |= SF_ASSIGNED;
}
strm->pend_pos = NULL;
pool_free(pool_head_pendconn, p);
return 0;
}
static enum act_return action_set_priority_class(struct act_rule *rule, struct proxy *px,
struct session *sess, struct stream *s, int flags)
{
struct sample *smp;
smp = sample_fetch_as_type(px, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.expr, SMP_T_SINT);
if (!smp)
return ACT_RET_CONT;
s->priority_class = queue_limit_class(smp->data.u.sint);
return ACT_RET_CONT;
}
static enum act_return action_set_priority_offset(struct act_rule *rule, struct proxy *px,
struct session *sess, struct stream *s, int flags)
{
struct sample *smp;
smp = sample_fetch_as_type(px, sess, s, SMP_OPT_DIR_REQ|SMP_OPT_FINAL, rule->arg.expr, SMP_T_SINT);
if (!smp)
return ACT_RET_CONT;
s->priority_offset = queue_limit_offset(smp->data.u.sint);
return ACT_RET_CONT;
}
static enum act_parse_ret parse_set_priority_class(const char **args, int *arg, struct proxy *px,
struct act_rule *rule, char **err)
{
unsigned int where = 0;
rule->arg.expr = sample_parse_expr((char **)args, arg, px->conf.args.file,
px->conf.args.line, err, &px->conf.args, NULL);
if (!rule->arg.expr)
return ACT_RET_PRS_ERR;
if (px->cap & PR_CAP_FE)
where |= SMP_VAL_FE_HRQ_HDR;
if (px->cap & PR_CAP_BE)
where |= SMP_VAL_BE_HRQ_HDR;
if (!(rule->arg.expr->fetch->val & where)) {
memprintf(err,
"fetch method '%s' extracts information from '%s', none of which is available here",
args[0], sample_src_names(rule->arg.expr->fetch->use));
free(rule->arg.expr);
return ACT_RET_PRS_ERR;
}
rule->action = ACT_CUSTOM;
rule->action_ptr = action_set_priority_class;
return ACT_RET_PRS_OK;
}
static enum act_parse_ret parse_set_priority_offset(const char **args, int *arg, struct proxy *px,
struct act_rule *rule, char **err)
{
unsigned int where = 0;
rule->arg.expr = sample_parse_expr((char **)args, arg, px->conf.args.file,
px->conf.args.line, err, &px->conf.args, NULL);
if (!rule->arg.expr)
return ACT_RET_PRS_ERR;
if (px->cap & PR_CAP_FE)
where |= SMP_VAL_FE_HRQ_HDR;
if (px->cap & PR_CAP_BE)
where |= SMP_VAL_BE_HRQ_HDR;
if (!(rule->arg.expr->fetch->val & where)) {
memprintf(err,
"fetch method '%s' extracts information from '%s', none of which is available here",
args[0], sample_src_names(rule->arg.expr->fetch->use));
free(rule->arg.expr);
return ACT_RET_PRS_ERR;
}
rule->action = ACT_CUSTOM;
rule->action_ptr = action_set_priority_offset;
return ACT_RET_PRS_OK;
}
static struct action_kw_list tcp_cont_kws = {ILH, {
{ "set-priority-class", parse_set_priority_class },
{ "set-priority-offset", parse_set_priority_offset },
{ /* END */ }
}};
INITCALL1(STG_REGISTER, tcp_req_cont_keywords_register, &tcp_cont_kws);
static struct action_kw_list http_req_kws = {ILH, {
{ "set-priority-class", parse_set_priority_class },
{ "set-priority-offset", parse_set_priority_offset },
{ /* END */ }
}};
INITCALL1(STG_REGISTER, http_req_keywords_register, &http_req_kws);
static int
smp_fetch_priority_class(const struct arg *args, struct sample *smp, const char *kw, void *private)
{
if (!smp->strm)
return 0;
smp->data.type = SMP_T_SINT;
smp->data.u.sint = smp->strm->priority_class;
return 1;
}
static int
smp_fetch_priority_offset(const struct arg *args, struct sample *smp, const char *kw, void *private)
{
if (!smp->strm)
return 0;
smp->data.type = SMP_T_SINT;
smp->data.u.sint = smp->strm->priority_offset;
return 1;
}
static struct sample_fetch_kw_list smp_kws = {ILH, {
{ "prio_class", smp_fetch_priority_class, 0, NULL, SMP_T_SINT, SMP_USE_INTRN, },
{ "prio_offset", smp_fetch_priority_offset, 0, NULL, SMP_T_SINT, SMP_USE_INTRN, },
{ /* END */},
}};
INITCALL1(STG_REGISTER, sample_register_fetches, &smp_kws);
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/