Mercurial > hg > nginx-ranges
diff src/http/modules/ngx_http_limit_req_module.c @ 425:b4f69f2ef02c NGINX_0_7_20
nginx 0.7.20
*) Changes in the ngx_http_gzip_filter_module.
*) Feature: the ngx_http_limit_req_module.
*) Bugfix: worker processes might exit on a SIGBUS signal on sparc and
ppc platforms; the bug had appeared in 0.7.3.
Thanks to Maxim Dounin.
*) Bugfix: the "proxy_pass http://host/some:uri" directives did not
work; the bug had appeared in 0.7.12.
*) Bugfix: in HTTPS mode requests might fail with the "bad write retry"
error.
*) Bugfix: the ngx_http_secure_link_module did not work inside
locations, whose names are less than 3 characters.
*) Bugfix: $server_addr variable might have no value.
author | Igor Sysoev <http://sysoev.ru> |
---|---|
date | Mon, 10 Nov 2008 00:00:00 +0300 |
parents | |
children | ff86d646f9df |
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new file mode 100644 --- /dev/null +++ b/src/http/modules/ngx_http_limit_req_module.c @@ -0,0 +1,794 @@ + +/* + * Copyright (C) Igor Sysoev + */ + + +#include <ngx_config.h> +#include <ngx_core.h> +#include <ngx_http.h> + + +typedef struct { + u_char color; + u_char dummy; + u_short len; + ngx_queue_t queue; + ngx_msec_t last; + float rate; + u_char data[1]; +} ngx_http_limit_req_node_t; + + +typedef struct { + ngx_rbtree_t *rbtree; + ngx_queue_t *queue; + ngx_slab_pool_t *shpool; + float rate; + ngx_int_t index; + ngx_str_t var; +} ngx_http_limit_req_ctx_t; + + +typedef struct { + ngx_shm_zone_t *shm_zone; + float burst; + ngx_msec_t delay; +} ngx_http_limit_req_conf_t; + + +static void ngx_http_limit_req_delay(ngx_http_request_t *r); +static ngx_int_t ngx_http_limit_req_lookup(ngx_http_limit_req_conf_t *lzcf, + ngx_uint_t hash, u_char *data, size_t len, ngx_http_limit_req_node_t **lzp); +static void ngx_http_limit_req_expire(ngx_http_limit_req_ctx_t *ctx, + ngx_uint_t n); + +static void *ngx_http_limit_req_create_conf(ngx_conf_t *cf); +static char *ngx_http_limit_req_merge_conf(ngx_conf_t *cf, void *parent, + void *child); +static char *ngx_http_limit_req_zone(ngx_conf_t *cf, ngx_command_t *cmd, + void *conf); +static char *ngx_http_limit_req(ngx_conf_t *cf, ngx_command_t *cmd, + void *conf); +static ngx_int_t ngx_http_limit_req_init(ngx_conf_t *cf); + + +static ngx_command_t ngx_http_limit_req_commands[] = { + + { ngx_string("limit_req_zone"), + NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE3, + ngx_http_limit_req_zone, + 0, + 0, + NULL }, + + { ngx_string("limit_req"), + NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE123, + ngx_http_limit_req, + NGX_HTTP_LOC_CONF_OFFSET, + 0, + NULL }, + + ngx_null_command +}; + + +static ngx_http_module_t ngx_http_limit_req_module_ctx = { + NULL, /* preconfiguration */ + ngx_http_limit_req_init, /* postconfiguration */ + + NULL, /* create main configuration */ + NULL, /* init main configuration */ + + NULL, /* create server configuration */ + NULL, /* merge server configuration */ + + ngx_http_limit_req_create_conf, /* create location configration */ + ngx_http_limit_req_merge_conf /* merge location configration */ +}; + + +ngx_module_t ngx_http_limit_req_module = { + NGX_MODULE_V1, + &ngx_http_limit_req_module_ctx, /* module context */ + ngx_http_limit_req_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 ngx_int_t +ngx_http_limit_req_handler(ngx_http_request_t *r) +{ + float rate; + size_t len, n; + uint32_t hash; + ngx_int_t rc; + ngx_time_t *tp; + ngx_rbtree_node_t *node; + ngx_http_variable_value_t *vv; + ngx_http_limit_req_ctx_t *ctx; + ngx_http_limit_req_node_t *lz; + ngx_http_limit_req_conf_t *lzcf; + + if (r->main->limit_req_set) { + return NGX_DECLINED; + } + + lzcf = ngx_http_get_module_loc_conf(r, ngx_http_limit_req_module); + + if (lzcf->shm_zone == NULL) { + return NGX_DECLINED; + } + + ctx = lzcf->shm_zone->data; + + vv = ngx_http_get_indexed_variable(r, ctx->index); + + if (vv == NULL || vv->not_found) { + return NGX_DECLINED; + } + + len = vv->len; + + if (len == 0) { + return NGX_DECLINED; + } + + 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\"", + &ctx->var, vv); + return NGX_DECLINED; + } + + r->main->limit_req_set = 1; + + hash = ngx_crc32_short(vv->data, len); + + ngx_shmtx_lock(&ctx->shpool->mutex); + + ngx_http_limit_req_expire(ctx, 1); + + rc = ngx_http_limit_req_lookup(lzcf, hash, vv->data, len, &lz); + + if (lz) { + ngx_queue_remove(&lz->queue); + + ngx_queue_insert_head(ctx->queue, &lz->queue); + + rate = lz->rate; + + } else { + rate = 0.0; + } + + ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, + "limit_req: %i %.3f", rc, rate); + + if (rc == NGX_BUSY) { + ngx_shmtx_unlock(&ctx->shpool->mutex); + + ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, + "limiting requests, %.3f r/s", rate); + + return NGX_HTTP_SERVICE_UNAVAILABLE; + } + + if (rc == NGX_AGAIN) { + ngx_shmtx_unlock(&ctx->shpool->mutex); + + if (lzcf->delay) { + ngx_log_error(NGX_LOG_WARN, r->connection->log, 0, + "delaying requests, %.3f r/s", rate); + + 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_req_delay; + ngx_add_timer(r->connection->write, lzcf->delay); + + return NGX_AGAIN; + } + + return NGX_DECLINED; + } + + if (rc == NGX_OK) { + goto done; + } + + /* rc == NGX_DECLINED */ + + n = offsetof(ngx_rbtree_node_t, color) + + offsetof(ngx_http_limit_req_node_t, data) + + len; + + node = ngx_slab_alloc_locked(ctx->shpool, n); + if (node == NULL) { + + ngx_http_limit_req_expire(ctx, 0); + + node = ngx_slab_alloc_locked(ctx->shpool, n); + if (node == NULL) { + ngx_shmtx_unlock(&ctx->shpool->mutex); + return NGX_HTTP_SERVICE_UNAVAILABLE; + } + } + + lz = (ngx_http_limit_req_node_t *) &node->color; + + node->key = hash; + lz->len = (u_char) len; + + tp = ngx_timeofday(); + lz->last = (ngx_msec_t) (tp->sec * 1000 + tp->msec); + + lz->rate = 0.0; + ngx_memcpy(lz->data, vv->data, len); + + ngx_rbtree_insert(ctx->rbtree, node); + + ngx_queue_insert_head(ctx->queue, &lz->queue); + +done: + + ngx_shmtx_unlock(&ctx->shpool->mutex); + + return NGX_DECLINED; +} + + +static void +ngx_http_limit_req_delay(ngx_http_request_t *r) +{ + ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, + "limit_req delay"); + + 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_req_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_req_node_t *lzn, *lznt; + + for ( ;; ) { + + if (node->key < temp->key) { + + p = &temp->left; + + } else if (node->key > temp->key) { + + p = &temp->right; + + } else { /* node->key == temp->key */ + + lzn = (ngx_http_limit_req_node_t *) &node->color; + lznt = (ngx_http_limit_req_node_t *) &temp->color; + + p = (ngx_memn2cmp(lzn->data, lznt->data, lzn->len, lznt->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_req_lookup(ngx_http_limit_req_conf_t *lzcf, ngx_uint_t hash, + u_char *data, size_t len, ngx_http_limit_req_node_t **lzp) +{ + ngx_int_t rc; + ngx_time_t *tp; + ngx_msec_t now; + ngx_msec_int_t ms; + ngx_rbtree_node_t *node, *sentinel; + ngx_http_limit_req_ctx_t *ctx; + ngx_http_limit_req_node_t *lz; + + ctx = lzcf->shm_zone->data; + + node = ctx->rbtree->root; + sentinel = ctx->rbtree->sentinel; + + while (node != sentinel) { + + if (hash < node->key) { + node = node->left; + continue; + } + + if (hash > node->key) { + node = node->right; + continue; + } + + /* hash == node->key */ + + do { + lz = (ngx_http_limit_req_node_t *) &node->color; + + rc = ngx_memn2cmp(data, lz->data, len, (size_t) lz->len); + + if (rc == 0) { + + tp = ngx_timeofday(); + + now = (ngx_msec_t) (tp->sec * 1000 + tp->msec); + ms = (ngx_msec_int_t) (now - lz->last); + + lz->rate = lz->rate - ctx->rate * ngx_abs(ms) / 1000 + 1; + + if (lz->rate < 0.0) { + lz->rate = 0.0; + } + + lz->last = now; + + *lzp = lz; + + if (lz->rate > lzcf->burst) { + return NGX_BUSY; + } + + if (lz->rate > ctx->rate) { + return NGX_AGAIN; + } + + return NGX_OK; + } + + node = (rc < 0) ? node->left : node->right; + + } while (node != sentinel && hash == node->key); + + break; + } + + *lzp = NULL; + + return NGX_DECLINED; +} + + +static void +ngx_http_limit_req_expire(ngx_http_limit_req_ctx_t *ctx, ngx_uint_t n) +{ + float rate; + 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_req_node_t *lz; + + 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 + */ + + while (n < 3) { + + if (ngx_queue_empty(ctx->queue)) { + return; + } + + q = ngx_queue_last(ctx->queue); + + lz = ngx_queue_data(q, ngx_http_limit_req_node_t, queue); + + if (n++ != 0) { + + ms = (ngx_msec_int_t) (now - lz->last); + ms = ngx_abs(ms); + + if (ms < 60000) { + return; + } + + rate = lz->rate - ctx->rate * ms / 1000; + + if (rate > 0.0) { + return; + } + } + + ngx_queue_remove(q); + + node = (ngx_rbtree_node_t *) + ((u_char *) lz - offsetof(ngx_rbtree_node_t, color)); + + ngx_rbtree_delete(ctx->rbtree, node); + + ngx_slab_free_locked(ctx->shpool, node); + } +} + + +static ngx_int_t +ngx_http_limit_req_init_zone(ngx_shm_zone_t *shm_zone, void *data) +{ + ngx_http_limit_req_ctx_t *octx = data; + + ngx_rbtree_node_t *sentinel; + ngx_http_limit_req_ctx_t *ctx; + + ctx = shm_zone->data; + + if (octx) { + if (ngx_strcmp(ctx->var.data, octx->var.data) != 0) { + ngx_log_error(NGX_LOG_EMERG, shm_zone->shm.log, 0, + "limit_req \"%V\" uses the \"%V\" variable " + "while previously it used the \"%V\" variable", + &shm_zone->name, &ctx->var, &octx->var); + return NGX_ERROR; + } + + ctx->rbtree = octx->rbtree; + ctx->queue = octx->queue; + ctx->shpool = octx->shpool; + + return NGX_OK; + } + + ctx->shpool = (ngx_slab_pool_t *) shm_zone->shm.addr; + + ctx->rbtree = ngx_slab_alloc(ctx->shpool, sizeof(ngx_rbtree_t)); + if (ctx->rbtree == NULL) { + return NGX_ERROR; + } + + sentinel = ngx_slab_alloc(ctx->shpool, sizeof(ngx_rbtree_node_t)); + if (sentinel == NULL) { + return NGX_ERROR; + } + + ngx_rbtree_init(ctx->rbtree, sentinel, + ngx_http_limit_req_rbtree_insert_value); + + ctx->queue = ngx_slab_alloc(ctx->shpool, sizeof(ngx_queue_t)); + if (ctx->queue == NULL) { + return NGX_ERROR; + } + + ngx_queue_init(ctx->queue); + + return NGX_OK; +} + + +static void * +ngx_http_limit_req_create_conf(ngx_conf_t *cf) +{ + ngx_http_limit_req_conf_t *conf; + + conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_req_conf_t)); + if (conf == NULL) { + return NGX_CONF_ERROR; + } + + /* + * set by ngx_pcalloc(): + * + * conf->shm_zone = NULL; + * conf->burst = 0.0; + * conf->delay = 0; + */ + + return conf; +} + + +static char * +ngx_http_limit_req_merge_conf(ngx_conf_t *cf, void *parent, void *child) +{ + ngx_http_limit_req_conf_t *prev = parent; + ngx_http_limit_req_conf_t *conf = child; + + if (conf->shm_zone == NULL) { + *conf = *prev; + } + + return NGX_CONF_OK; +} + + +static char * +ngx_http_limit_req_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) +{ + u_char *p; + size_t size, len; + ngx_str_t *value, name, s; + ngx_int_t rate, scale; + ngx_uint_t i; + ngx_shm_zone_t *shm_zone; + ngx_http_limit_req_ctx_t *ctx; + + value = cf->args->elts; + + ctx = NULL; + size = 0; + rate = 1; + scale = 1; + name.len = 0; + + for (i = 1; i < cf->args->nelts; i++) { + + if (ngx_strncmp(value[i].data, "zone=", 5) == 0) { + + name.data = value[i].data + 5; + + p = (u_char *) ngx_strchr(name.data, ':'); + + if (p) { + name.len = p - name.data; + + p++; + + s.len = value[i].data + value[i].len - p; + s.data = p; + + size = ngx_parse_size(&s); + if (size > 8191) { + continue; + } + } + + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid zone size \"%V\"", &value[i]); + return NGX_CONF_ERROR; + } + + if (ngx_strncmp(value[i].data, "rate=", 5) == 0) { + + len = value[i].len; + p = value[i].data + len - 3; + + if (ngx_strncmp(p, "r/s", 3) == 0) { + scale = 1; + len -= 3; + + } else if (ngx_strncmp(p, "r/m", 3) == 0) { + scale = 60; + len -= 3; + } + + rate = ngx_atoi(value[i].data + 5, len - 5); + if (rate <= NGX_ERROR) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid rate \"%V\"", &value[i]); + return NGX_CONF_ERROR; + } + + continue; + } + + if (value[i].data[0] == '$') { + + value[i].len--; + value[i].data++; + + ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_req_ctx_t)); + if (ctx == NULL) { + return NGX_CONF_ERROR; + } + + ctx->index = ngx_http_get_variable_index(cf, &value[i]); + if (ctx->index == NGX_ERROR) { + return NGX_CONF_ERROR; + } + + ctx->var = value[i]; + + continue; + } + + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid parameter \"%V\"", &value[i]); + return NGX_CONF_ERROR; + } + + if (name.len == 0 || size == 0) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "\"%V\" must have \"zone\" parameter", + &cmd->name); + return NGX_CONF_ERROR; + } + + if (ctx == NULL) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "no variable is defined for limit_req_zone \"%V\"", + &cmd->name); + return NGX_CONF_ERROR; + } + + ctx->rate = (float) rate / scale; + + shm_zone = ngx_shared_memory_add(cf, &name, size, + &ngx_http_limit_req_module); + if (shm_zone == NULL) { + return NGX_CONF_ERROR; + } + + if (shm_zone->data) { + ctx = shm_zone->data; + + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "limit_req_zone \"%V\" is already bound to variable \"%V\"", + &value[1], &ctx->var); + return NGX_CONF_ERROR; + } + + shm_zone->init = ngx_http_limit_req_init_zone; + shm_zone->data = ctx; + + return NGX_CONF_OK; +} + + +static char * +ngx_http_limit_req(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) +{ + ngx_http_limit_req_conf_t *lzcf = conf; + + u_char *p; + size_t len; + ngx_int_t burst, scale, delay; + ngx_str_t *value, s; + ngx_uint_t i; + ngx_http_limit_req_ctx_t *ctx; + + if (lzcf->shm_zone) { + return "is duplicate"; + } + + value = cf->args->elts; + + burst = 0; + scale = 1; + delay = 0; + + for (i = 1; i < cf->args->nelts; i++) { + + if (ngx_strncmp(value[i].data, "zone=", 5) == 0) { + + s.len = value[i].len - 5; + s.data = value[i].data + 5; + + lzcf->shm_zone = ngx_shared_memory_add(cf, &s, 0, + &ngx_http_limit_req_module); + if (lzcf->shm_zone == NULL) { + return NGX_CONF_ERROR; + } + + continue; + } + + if (ngx_strncmp(value[i].data, "burst=", 6) == 0) { + + len = value[i].len; + p = value[i].data + len - 3; + + if (ngx_strncmp(p, "r/s", 3) == 0) { + scale = 1; + len -= 3; + + } else if (ngx_strncmp(p, "r/m", 3) == 0) { + scale = 60; + len -= 3; + } + + burst = ngx_atoi(value[i].data + 6, len - 6); + if (burst <= 0) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid burst rate \"%V\"", &value[i]); + return NGX_CONF_ERROR; + } + + continue; + } + + if (ngx_strncmp(value[i].data, "delay=", 6) == 0) { + + s.len = value[i].len - 6; + s.data = value[i].data + 6; + + delay = ngx_parse_time(&s, 0); + if (delay < 0) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid clean_time value \"%V\"", &value[i]); + return NGX_CONF_ERROR; + } + + continue; + } + + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid parameter \"%V\"", &value[i]); + return NGX_CONF_ERROR; + } + + if (lzcf->shm_zone == NULL) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "\"%V\" must have \"zone\" parameter", + &cmd->name); + return NGX_CONF_ERROR; + } + + if (lzcf->shm_zone->data == NULL) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "unknown limit_req_zone \"%V\"", + &lzcf->shm_zone->name); + return NGX_CONF_ERROR; + } + + if (burst) { + lzcf->burst = (float) burst / scale; + + } else { + ctx = lzcf->shm_zone->data; + lzcf->burst = ctx->rate; + } + + lzcf->delay = (ngx_msec_t) delay; + + return NGX_CONF_OK; +} + + +static ngx_int_t +ngx_http_limit_req_init(ngx_conf_t *cf) +{ + ngx_http_handler_pt *h; + ngx_http_core_main_conf_t *cmcf; + + cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); + + h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers); + if (h == NULL) { + return NGX_ERROR; + } + + *h = ngx_http_limit_req_handler; + + return NGX_OK; +}