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ngx_http_limit_req2_module.c
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/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#define LIMIT_REQ2_BLOCK_ACTION_NONE 0
#define LIMIT_REQ2_BLOCK_ACTION_QUERY 1
#define LIMIT_REQ2_BLOCK_ACTION_SET 2
#define LIMIT_REQ2_BLOCK_ACTION_CLEAR 3
typedef struct {
u_char color;
u_char dummy;
u_short len;
ngx_queue_t queue;
ngx_msec_t last;
/* integer value, 1 corresponds to 0.001 r/s */
ngx_uint_t excess;
ngx_uint_t count;
uint64_t block_stat;
ngx_uint_t block_stat_base;
ngx_uint_t block_stop_time;
/* range count for computing qps */
ngx_uint_t last_seg;
ngx_uint_t curr_seg;
u_char data[1];
} ngx_http_limit_req2_node_t;
typedef struct {
ngx_rbtree_t rbtree;
ngx_rbtree_node_t sentinel;
ngx_queue_t queue;
} ngx_http_limit_req2_shctx_t;
typedef struct {
ngx_int_t index;
ngx_str_t var;
} ngx_http_limit_req2_variable_t;
typedef struct {
ngx_int_t index;
ngx_str_t var;
} ngx_http_limit_req_variable_t;
typedef struct {
ngx_http_limit_req2_shctx_t *sh;
ngx_slab_pool_t *shpool;
/* integer value, 1 corresponds to 0.001 r/s */
ngx_uint_t rate;
ngx_http_complex_value_t key;
ngx_http_limit_req2_node_t *node;
ngx_uint_t rate_seg;
ngx_uint_t last_seg;
ngx_uint_t curr_seg;
ngx_uint_t curr_seg_time_diff;
ngx_array_t *limit_vars;
} ngx_http_limit_req2_ctx_t;
typedef struct {
ngx_shm_zone_t *shm_zone;
/* integer value, 1 corresponds to 0.001 r/s */
ngx_uint_t burst;
ngx_uint_t nodelay; /* unsigned nodelay:1 */
ngx_str_t forbid_action;
/* 5x60x1800 */
ngx_uint_t block_stat_interval; /* 60 */
ngx_uint_t block_stat_times; /* 5 */
ngx_uint_t block_time; /* 1800 */
ngx_uint_t rate_seg;
} ngx_http_limit_req2_t;
typedef struct {
ngx_flag_t enable;
ngx_array_t *rules;
ngx_str_t geo_var_name;
ngx_int_t geo_var_index;
ngx_str_t geo_var_value;
ngx_array_t limits;
ngx_uint_t limit_log_level;
ngx_uint_t delay_log_level;
ngx_uint_t status_code;
ngx_int_t block_action;
ngx_int_t block_time;
ngx_shm_zone_t *block_shm_zone;
ngx_array_t *block_limit_vars;
ngx_int_t enable_record_rate;
} ngx_http_limit_req2_conf_t;
static ngx_str_t ngx_http_limit_req2_rate = ngx_string("limit_req2_rate");
static void ngx_http_limit_req2_delay(ngx_http_request_t *r);
static ngx_int_t ngx_http_limit_req2_lookup(ngx_http_request_t *r,
ngx_http_limit_req2_t *limit_req2, ngx_uint_t hash, ngx_uint_t *ep,
ngx_uint_t *bst, ngx_uint_t *last_seg, ngx_uint_t *curr_seg,
ngx_uint_t *curr_seg_time_diff, ngx_int_t block_action);
static void ngx_http_limit_req2_expire(ngx_http_request_t *r,
ngx_http_limit_req2_ctx_t *ctx, ngx_uint_t n);
static void *ngx_http_limit_req2_create_conf(ngx_conf_t *cf);
static char *ngx_http_limit_req2_merge_conf(ngx_conf_t *cf, void *parent,
void *child);
static char *ngx_http_limit_req2_zone(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static char *ngx_http_limit_req2(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static char *ngx_http_limit_req2_whitelist(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static char *ngx_http_limit_req2_block(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
static ngx_int_t ngx_http_limit_req2_init(ngx_conf_t *cf);
static ngx_int_t ngx_http_limit_req2_add_variables(ngx_conf_t *cf);
static inline
int get_stat_bit(uint64_t stat, int idx)
{
stat >>= idx;
return stat & 1;
}
static inline
void set_stat_bit(uint64_t *pstat, int idx, int val)
{
uint64_t tmp = val <<= idx;
*pstat |= tmp;
}
static ngx_conf_enum_t ngx_http_limit_req2_log_levels[] = {
{ ngx_string("info"), NGX_LOG_INFO },
{ ngx_string("notice"), NGX_LOG_NOTICE },
{ ngx_string("warn"), NGX_LOG_WARN },
{ ngx_string("error"), NGX_LOG_ERR },
{ ngx_null_string, 0 }
};
static ngx_conf_num_bounds_t ngx_http_limit_req2_status_bounds = {
ngx_conf_check_num_bounds, 400, 599
};
static ngx_command_t ngx_http_limit_req2_commands[] = {
{ ngx_string("limit_req2_zone"),
NGX_HTTP_MAIN_CONF|NGX_CONF_2MORE,
ngx_http_limit_req2_zone,
0,
0,
NULL },
{ ngx_string("limit_req2"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1234,
ngx_http_limit_req2,
NGX_HTTP_LOC_CONF_OFFSET,
0,
NULL },
{ ngx_string("limit_req2_whitelist"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
ngx_http_limit_req2_whitelist,
NGX_HTTP_LOC_CONF_OFFSET,
0,
NULL },
{ ngx_string("limit_req2_log_level"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_conf_set_enum_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_limit_req2_conf_t, limit_log_level),
&ngx_http_limit_req2_log_levels },
{ ngx_string("limit_req2_status"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_limit_req2_conf_t, status_code),
&ngx_http_limit_req2_status_bounds },
{ ngx_string("limit_req2_block"),
NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_2MORE,
ngx_http_limit_req2_block,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_limit_req2_conf_t, enable),
NULL },
ngx_null_command
};
static ngx_http_module_t ngx_http_limit_req2_module_ctx = {
ngx_http_limit_req2_add_variables, /* preconfiguration */
ngx_http_limit_req2_init, /* postconfiguration */
NULL, /* create main configuration */
NULL, /* init main configuration */
NULL, /* create server configuration */
NULL, /* merge server configuration */
ngx_http_limit_req2_create_conf, /* create location configuration */
ngx_http_limit_req2_merge_conf /* merge location configuration */
};
ngx_module_t ngx_http_limit_req2_module = {
NGX_MODULE_V1,
&ngx_http_limit_req2_module_ctx, /* module context */
ngx_http_limit_req2_commands, /* module directives */
NGX_HTTP_MODULE, /* module type */
NULL, /* init master */
NULL, /* init module */
NULL, /* init process */
NULL, /* init thread */
NULL, /* exit thread */
NULL, /* exit process */
NULL, /* exit master */
NGX_MODULE_V1_PADDING
};
static inline ngx_int_t
ngx_http_limit_req2_ip_filter(ngx_http_request_t *r,
ngx_http_limit_req2_conf_t *lrcf)
{
ngx_http_variable_value_t *vv;
if (lrcf->geo_var_index != NGX_CONF_UNSET) {
vv = ngx_http_get_indexed_variable(r, lrcf->geo_var_index);
if (vv == NULL || vv->not_found) {
return NGX_DECLINED;
}
if ((vv->len == lrcf->geo_var_value.len)
&& (ngx_memcmp(vv->data, lrcf->geo_var_value.data, vv->len) == 0))
{
return NGX_OK;
}
}
return NGX_DECLINED;
}
static ngx_int_t
ngx_http_limit_req2_copy_variables(ngx_http_request_t *r, uint32_t *hash,
ngx_array_t *limit_vars, ngx_http_limit_req2_node_t *node)
{
u_char *p;
size_t len, total_len;
ngx_uint_t j;
ngx_http_variable_value_t *vv;
ngx_http_limit_req2_variable_t *lrv;
len = 0;
total_len = 0;
p = NULL;
if (node != NULL) {
p = node->data;
}
lrv = limit_vars->elts;
for (j = 0; j < limit_vars->nelts; j++) {
vv = ngx_http_get_indexed_variable(r, lrv[j].index);
if (vv == NULL || vv->not_found) {
total_len = 0;
break;
}
len = vv->len;
if (len == 0) {
total_len = 0;
break;
}
if (len > 65535) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"the value of the \"%V\" variable "
"is more than 65535 bytes: \"%v\"",
&lrv[j].var, vv);
total_len = 0;
break;
}
if (node == NULL) {
total_len += len;
ngx_crc32_update(hash, vv->data, len);
} else {
p = ngx_cpymem(p, vv->data, len);
}
}
return total_len;
}
static ngx_int_t
ngx_http_limit_req2_handler(ngx_http_request_t *r)
{
size_t n, total_len;
uint32_t hash;
ngx_int_t rc;
ngx_msec_t delay_time;
ngx_uint_t excess, delay_excess, delay_postion,
nodelay, i;
ngx_time_t *tp;
ngx_rbtree_node_t *node;
ngx_http_limit_req2_t *limit_req2;
ngx_http_limit_req2_ctx_t *ctx;
ngx_http_limit_req2_node_t *lr;
ngx_http_limit_req2_conf_t *lrcf;
ngx_uint_t last_seg, curr_seg, curr_seg_time_diff;
ngx_uint_t block_stop_time = 0;
delay_excess = 0;
excess = 0;
delay_postion = 0;
nodelay = 0;
ctx = NULL;
rc = NGX_DECLINED;
last_seg = 0;
curr_seg = 0;
curr_seg_time_diff = 0;
if (r->main->limit_req_set) {
return NGX_DECLINED;
}
lrcf = ngx_http_get_module_loc_conf(r, ngx_http_limit_req2_module);
if (lrcf->rules == NULL) {
return NGX_DECLINED;
}
if (!lrcf->enable) {
return NGX_DECLINED;
}
/* filter whitelist */
if (ngx_http_limit_req2_ip_filter(r, lrcf) == NGX_OK) {
return NGX_DECLINED;
}
/* to match limit_req2 rule*/
limit_req2 = lrcf->rules->elts;
for (i = 0; i < lrcf->rules->nelts; i++) {
ctx = limit_req2[i].shm_zone->data;
ngx_crc32_init(hash);
total_len = ngx_http_limit_req2_copy_variables(
r, &hash, ctx->limit_vars, NULL);
if (total_len == 0) {
continue;
}
ngx_crc32_final(hash);
ngx_shmtx_lock(&ctx->shpool->mutex);
ngx_http_limit_req2_expire(r, ctx, 1);
excess = 0;
rc = ngx_http_limit_req2_lookup(r, &limit_req2[i], hash, &excess,
&block_stop_time, &last_seg, &curr_seg,
&curr_seg_time_diff, 0);
ngx_log_debug6(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2 module: %i %ui.%03ui "
"block_stop_time: %ui "
"hash is %D total_len is %uz",
rc, excess / 1000, excess % 1000,
block_stop_time,
hash, total_len);
/*
* add variable for computing rate
*/
if (limit_req2[i].rate_seg > 0) {
ctx->rate_seg = limit_req2[i].rate_seg;
ctx->last_seg = last_seg;
ctx->curr_seg = curr_seg;
ctx->curr_seg_time_diff = curr_seg_time_diff;
ngx_log_debug4(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2 rate_seg : %ui "
"last_seg : %ui "
"curr_seg : %ui "
"curr_seg_time_diff : %ui",
limit_req2[i].rate_seg, last_seg, curr_seg, curr_seg_time_diff);
}
/* first limit_req2 */
if (rc == NGX_DECLINED) {
n = offsetof(ngx_rbtree_node_t, color)
+ offsetof(ngx_http_limit_req2_node_t, data)
+ total_len;
node = ngx_slab_alloc_locked(ctx->shpool, n);
if (node == NULL) {
ngx_http_limit_req2_expire(r, ctx, 0);
node = ngx_slab_alloc_locked(ctx->shpool, n);
if (node == NULL) {
ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
"could not allocate node%s",
ctx->shpool->log_ctx);
ngx_shmtx_unlock(&ctx->shpool->mutex);
return lrcf->status_code;
}
}
lr = (ngx_http_limit_req2_node_t *) &node->color;
node->key = hash;
lr->len = (u_short) total_len;
tp = ngx_timeofday();
lr->last = (ngx_msec_t) (tp->sec * 1000 + tp->msec);
lr->excess = 0;
lr->block_stat = 0;
lr->block_stat_base = 0;
lr->block_stop_time = 0;
lr->last_seg = 0;
lr->curr_seg = 1;
ngx_http_limit_req2_copy_variables(r, &hash, ctx->limit_vars, lr);
ngx_queue_insert_head(&ctx->sh->queue, &lr->queue);
ngx_rbtree_insert(&ctx->sh->rbtree, node);
ngx_shmtx_unlock(&ctx->shpool->mutex);
continue;
}
ngx_shmtx_unlock(&ctx->shpool->mutex);
if (rc == NGX_BUSY || rc == NGX_ERROR) {
break;
}
/* NGX_AGAIN or NGX_OK */
if (delay_excess < excess) {
delay_excess = excess;
nodelay = limit_req2[i].nodelay;
delay_postion = i;
}
}
r->main->limit_req_set = 1;
if (rc == NGX_BUSY || rc == NGX_ERROR) {
if (rc == NGX_BUSY) {
if (block_stop_time) {
ngx_log_error(lrcf->limit_log_level, r->connection->log, 0,
"limit_req2 blocking requests, "
"block_stop_time: %ui by zone \"%V\"",
block_stop_time,
&limit_req2[i].shm_zone->shm.name);
} else {
ngx_log_error(lrcf->limit_log_level, r->connection->log, 0,
"limit_req2 limiting requests, "
"excess: %ui.%03ui by zone \"%V\"",
excess / 1000, excess % 1000,
&limit_req2[i].shm_zone->shm.name);
}
}
if (rc == NGX_ERROR || limit_req2[i].forbid_action.len == 0) {
return lrcf->status_code;
} else if (limit_req2[i].forbid_action.data[0] == '@') {
ngx_log_error(lrcf->limit_log_level, r->connection->log, 0,
"limiting requests, forbid_action is %V",
&limit_req2[i].forbid_action);
(void) ngx_http_named_location(r, &limit_req2[i].forbid_action);
} else {
ngx_log_error(lrcf->limit_log_level, r->connection->log, 0,
"limiting requests, forbid_action is %V",
&limit_req2[i].forbid_action);
(void) ngx_http_internal_redirect(r,
&limit_req2[i].forbid_action,
&r->args);
}
ngx_http_finalize_request(r, NGX_DONE);
return NGX_DONE;
}
/* rc = NGX_AGAIN */
if (delay_excess != 0) {
if (nodelay) {
return NGX_DECLINED;
}
delay_time = (ngx_msec_t) delay_excess * 1000 / ctx->rate;
ngx_log_error(lrcf->delay_log_level, r->connection->log, 0,
"delaying request,"
"excess: %ui.%03ui, by zone \"%V\", delay \"%M\" ms",
delay_excess / 1000, delay_excess % 1000,
&limit_req2[delay_postion].shm_zone->shm.name, delay_time);
if (ngx_handle_read_event(r->connection->read, 0) != NGX_OK) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
r->read_event_handler = ngx_http_test_reading;
r->write_event_handler = ngx_http_limit_req2_delay;
ngx_add_timer(r->connection->write, delay_time);
return NGX_AGAIN;
}
/* rc == NGX_OK or rc == NGX_DECLINED */
return NGX_DECLINED;
}
static void
ngx_http_limit_req2_delay(ngx_http_request_t *r)
{
ngx_event_t *wev;
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2 delay");
wev = r->connection->write;
if (!wev->timedout) {
if (ngx_handle_write_event(wev, 0) != NGX_OK) {
ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
}
return;
}
wev->timedout = 0;
if (ngx_handle_read_event(r->connection->read, 0) != NGX_OK) {
ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
return;
}
r->read_event_handler = ngx_http_block_reading;
r->write_event_handler = ngx_http_core_run_phases;
ngx_http_core_run_phases(r);
}
static void
ngx_http_limit_req2_rbtree_insert_value(ngx_rbtree_node_t *temp,
ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
{
ngx_rbtree_node_t **p;
ngx_http_limit_req2_node_t *lrn, *lrnt;
for ( ;; ) {
if (node->key < temp->key) {
p = &temp->left;
} else if (node->key > temp->key) {
p = &temp->right;
} else { /* node->key == temp->key */
lrn = (ngx_http_limit_req2_node_t *) &node->color;
lrnt = (ngx_http_limit_req2_node_t *) &temp->color;
p = (ngx_memn2cmp(lrn->data, lrnt->data, lrn->len, lrnt->len) < 0)
? &temp->left : &temp->right;
}
if (*p == sentinel) {
break;
}
temp = *p;
}
*p = node;
node->parent = temp;
node->left = sentinel;
node->right = sentinel;
ngx_rbt_red(node);
}
static ngx_int_t
ngx_http_limit_req2_lookup(ngx_http_request_t *r,
ngx_http_limit_req2_t *limit_req2, ngx_uint_t hash, ngx_uint_t *ep,
ngx_uint_t *bst, ngx_uint_t *last_seg, ngx_uint_t *curr_seg,
ngx_uint_t *curr_seg_time_diff, ngx_int_t block_action)
{
u_char *lr_data, *lr_last;
size_t lr_vv_len;
ngx_int_t rc, excess;
ngx_uint_t i;
ngx_time_t *tp;
ngx_msec_t now;
ngx_msec_int_t ms;
ngx_rbtree_node_t *node, *sentinel;
ngx_http_limit_req2_ctx_t *ctx;
ngx_http_limit_req2_node_t *lr;
ngx_http_variable_value_t *vv;
ngx_http_limit_req2_variable_t *lrv;
ngx_http_limit_req2_conf_t *lrcf;
ngx_uint_t stat_interval, stat_times, now_sec, diff;
ngx_int_t check_all_bit, last_zero_pos;
ngx_uint_t j;
ngx_msec_t last_rate_seg;
ngx_msec_t curr_rate_seg;
ctx = limit_req2->shm_zone->data;
tp = ngx_timeofday();
now_sec = (ngx_uint_t) (tp->sec);
node = ctx->sh->rbtree.root;
sentinel = ctx->sh->rbtree.sentinel;
rc = -1;
lrv = ctx->limit_vars->elts;
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2_lookup hash : %i", hash);
while (node != sentinel) {
if (hash < node->key) {
node = node->left;
continue;
}
if (hash > node->key) {
node = node->right;
continue;
}
/* hash == node->key */
lr = (ngx_http_limit_req2_node_t *) &node->color;
lr_data = lr->data;
lr_last = lr_data + lr->len;
for (i = 0; i < ctx->limit_vars->nelts; i++) {
vv = ngx_http_get_indexed_variable(r, lrv[i].index);
ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2 vv is %i %v node is %s",
lrv[i].index, vv, lr_data);
lr_vv_len = ngx_min(lr_last - lr_data, vv->len);
if ((rc = ngx_memcmp(vv->data, lr_data, lr_vv_len)) != 0) {
break;
}
if (lr_vv_len != vv->len) {
rc = 1;
break;
}
/* lr_vv_len == vv->len */
lr_data += lr_vv_len;
}
if (rc == 0 && lr_last > lr_data) {
rc = -1;
}
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2 lookup is : %i, size is %ui",
rc, ctx->limit_vars->nelts);
if (rc == 0) {
ngx_queue_remove(&lr->queue);
ngx_queue_insert_head(&ctx->sh->queue, &lr->queue);
ngx_log_debug5(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"limit_req2 lookup sucess "
"block_action: %i "
"now_sec: %ui "
"block_stop_time: %i "
"excess: %ui.%03ui",
block_action, now_sec, lr->block_stop_time,
lr->excess / 1000, lr->excess % 1000);
if (block_action == LIMIT_REQ2_BLOCK_ACTION_QUERY) {
if (lr->block_stop_time > now_sec) {
*bst = lr->block_stop_time;
} else {
*bst = 0;
}
return NGX_OK;
} else if (block_action == LIMIT_REQ2_BLOCK_ACTION_SET) {
lrcf = ngx_http_get_module_loc_conf(r,
ngx_http_limit_req2_module);
lr->block_stop_time = now_sec + lrcf->block_time;
*bst = lr->block_stop_time;
return NGX_OK;
} else if (block_action == LIMIT_REQ2_BLOCK_ACTION_CLEAR) {
lr->block_stop_time = 0;
lr->excess = 0;
return NGX_OK;
} else {
now = (ngx_msec_t) (tp->sec * 1000 + tp->msec);
ms = (ngx_msec_int_t) (now - lr->last);
/* block check */
if (lr->block_stop_time >= now_sec) {
*bst = lr->block_stop_time;
return NGX_BUSY;
}
excess = lr->excess - ctx->rate * ngx_abs(ms) / 1000 + 1000;
if (excess < 0) {
excess = 0;
}
*ep = excess;
if ((ngx_uint_t) excess > limit_req2->burst) {
/* stat for block */
stat_times = limit_req2->block_stat_times;
if (stat_times != 0) {
stat_interval = limit_req2->block_stat_interval;
diff = now_sec - lr->block_stat_base;
if (diff >= stat_interval * stat_times) {
lr->block_stat_base = now_sec;
lr->block_stat = 1;
} else if (diff >= (stat_times-1) * stat_interval) {
set_stat_bit(&lr->block_stat,
stat_times - 1, 1);
check_all_bit = 1;
last_zero_pos = 0;
for (j = 0; j < stat_times - 1; ++j) {
if (!get_stat_bit(lr->block_stat, j)) {
check_all_bit = 0;
last_zero_pos = j;
}
}
if (check_all_bit) {
/* auto block */
lr->block_stop_time = now_sec
+ limit_req2->block_time;
lr->block_stat >>= 1;
lr->block_stat_base += stat_interval;
} else {
lr->block_stat >>= last_zero_pos + 1;
lr->block_stat_base += (last_zero_pos + 1)
* stat_interval;
}
} else {
set_stat_bit(&lr->block_stat,
diff / stat_interval, 1);
}
ngx_log_debug4(NGX_LOG_DEBUG_HTTP,
r->connection->log, 0,
"limit_req2 now_sec: %ui "
"block stop_time: %ui "
"block_stat_base: %ui "
"block stat: %ul ",
now_sec, lr->block_stop_time,
lr->block_stat_base, lr->block_stat);
}
return NGX_BUSY;
}
if (limit_req2->rate_seg != 0) {
last_rate_seg = lr->last / limit_req2->rate_seg;
curr_rate_seg = now / limit_req2->rate_seg;
if (curr_rate_seg > last_rate_seg + 1) {
lr->last_seg = 0;
lr->curr_seg = 1;
} else if (curr_rate_seg == last_rate_seg + 1) {
lr->last_seg = lr->curr_seg;
lr->curr_seg = 1;
} else if (curr_rate_seg == last_rate_seg) {
++lr->curr_seg;
} else {
/* never appear */
lr->last_seg = 0;
lr->curr_seg = 0;
}
*last_seg = lr->last_seg;
*curr_seg = lr->curr_seg;
*curr_seg_time_diff = now % limit_req2->rate_seg;
}
lr->excess = excess;
lr->last = now;
if (excess) {
return NGX_AGAIN;
}
return NGX_OK;
}
}
node = (rc < 0) ? node->left : node->right;
}
*ep = 0;
*last_seg = 0;
*curr_seg = 1;
*curr_seg_time_diff = 0;
return NGX_DECLINED;
}
static void
ngx_http_limit_req2_expire(ngx_http_request_t *r,
ngx_http_limit_req2_ctx_t *ctx, ngx_uint_t n)
{
ngx_int_t excess;
ngx_time_t *tp;
ngx_msec_t now;
ngx_queue_t *q;
ngx_msec_int_t ms;
ngx_rbtree_node_t *node;
ngx_http_limit_req2_node_t *lr;
ngx_http_limit_req2_node_t *first_lr;
ngx_uint_t m;
tp = ngx_timeofday();
now = (ngx_msec_t) (tp->sec * 1000 + tp->msec);
/*
* n == 1 deletes one or two zero rate entries
* n == 0 deletes oldest entry by force
* and one or two zero rate entries
*/
m = 0;
first_lr = NULL;
while (n < 3) {
if (ngx_queue_empty(&ctx->sh->queue)) {
return;
}
q = ngx_queue_last(&ctx->sh->queue);
lr = ngx_queue_data(q, ngx_http_limit_req2_node_t, queue);
if (lr->block_stop_time > (ngx_uint_t)tp->sec
&& first_lr != lr && m++ < 100) {
ngx_queue_remove(&lr->queue);
ngx_queue_insert_head(&ctx->sh->queue, &lr->queue);
continue;
}
if (m == 1) {
first_lr = lr;
}
if (n++ != 0) {
ms = (ngx_msec_int_t) (now - lr->last);
ms = ngx_abs(ms);
if (ms < 60000) {
return;
}
excess = lr->excess - ctx->rate * ms / 1000;
if (excess > 0) {
return;
}
}
ngx_queue_remove(q);
node = (ngx_rbtree_node_t *)
((u_char *) lr - offsetof(ngx_rbtree_node_t, color));
ngx_rbtree_delete(&ctx->sh->rbtree, node);
ngx_slab_free_locked(ctx->shpool, node);
}
}
static ngx_int_t
ngx_http_limit_req2_init_zone(ngx_shm_zone_t *shm_zone, void *data)
{
ngx_http_limit_req2_ctx_t *octx = data;
size_t len;
ngx_uint_t i, j;
ngx_http_limit_req2_ctx_t *ctx;
ngx_http_limit_req2_variable_t *v1, *v2;
ctx = shm_zone->data;
v1 = ctx->limit_vars->elts;
if (octx) {
v2 = octx->limit_vars->elts;
if (ctx->limit_vars->nelts != octx->limit_vars->nelts) {
ngx_log_error(NGX_LOG_EMERG, shm_zone->shm.log, 0,
"limit_req2 \"%V\" uses the \"%V\" variable "
"while previously it used the \"%V\" variable",
&shm_zone->shm.name, &v1[0].var, &v2[0].var);
return NGX_ERROR;
}
for (i = 0, j = 0;
i < ctx->limit_vars->nelts && j < octx->limit_vars->nelts;
i++, j++)