Mercurial > hg > nginx
view src/http/modules/ngx_http_limit_req_module.c @ 3496:fb88801564de
build nginx/Windows against OpenSSL-0.9.8n, since nginx-0.8.35
built against OpenSSL-1.0.0 crashed on Windows XP somewhere
in the NTDLL.DLL on the master process exit
author | Igor Sysoev <igor@sysoev.ru> |
---|---|
date | Wed, 21 Apr 2010 15:09:17 +0000 |
parents | 30f841e2536d |
children | eb156d98a9fa |
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/* * 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; /* integer value, 1 corresponds to 0.001 r/s */ ngx_uint_t excess; u_char data[1]; } ngx_http_limit_req_node_t; typedef struct { ngx_rbtree_t rbtree; ngx_rbtree_node_t sentinel; ngx_queue_t queue; } ngx_http_limit_req_shctx_t; typedef struct { ngx_http_limit_req_shctx_t *sh; ngx_slab_pool_t *shpool; /* integer value, 1 corresponds to 0.001 r/s */ ngx_uint_t rate; ngx_int_t index; ngx_str_t var; } ngx_http_limit_req_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 limit_log_level; ngx_uint_t delay_log_level; ngx_uint_t nodelay; /* unsigned nodelay:1 */ } 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 *lrcf, ngx_uint_t hash, u_char *data, size_t len, ngx_http_limit_req_node_t **lrp); 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_conf_enum_t ngx_http_limit_req_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_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_string("limit_req_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_req_conf_t, limit_log_level), &ngx_http_limit_req_log_levels }, 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) { size_t len, n; uint32_t hash; ngx_int_t rc; ngx_uint_t excess; 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 *lr; ngx_http_limit_req_conf_t *lrcf; if (r->main->limit_req_set) { return NGX_DECLINED; } lrcf = ngx_http_get_module_loc_conf(r, ngx_http_limit_req_module); if (lrcf->shm_zone == NULL) { return NGX_DECLINED; } ctx = lrcf->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(lrcf, hash, vv->data, len, &lr); if (lr) { ngx_queue_remove(&lr->queue); ngx_queue_insert_head(&ctx->sh->queue, &lr->queue); excess = lr->excess; } else { excess = 0; } ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "limit_req: %i %ui.%03ui", rc, excess / 1000, excess % 1000); if (rc == NGX_BUSY) { ngx_shmtx_unlock(&ctx->shpool->mutex); ngx_log_error(lrcf->limit_log_level, r->connection->log, 0, "limiting requests, excess: %ui.%03ui by zone \"%V\"", excess / 1000, excess % 1000, &lrcf->shm_zone->shm.name); return NGX_HTTP_SERVICE_UNAVAILABLE; } if (rc == NGX_AGAIN) { ngx_shmtx_unlock(&ctx->shpool->mutex); if (lrcf->nodelay) { return NGX_DECLINED; } ngx_log_error(lrcf->delay_log_level, r->connection->log, 0, "delaying request, excess: %ui.%03ui, by zone \"%V\"", excess / 1000, excess % 1000, &lrcf->shm_zone->shm.name); 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, (ngx_msec_t) excess); return NGX_AGAIN; } 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; } } lr = (ngx_http_limit_req_node_t *) &node->color; node->key = hash; lr->len = (u_char) len; tp = ngx_timeofday(); lr->last = (ngx_msec_t) (tp->sec * 1000 + tp->msec); lr->excess = 0; ngx_memcpy(lr->data, vv->data, len); ngx_rbtree_insert(&ctx->sh->rbtree, node); ngx_queue_insert_head(&ctx->sh->queue, &lr->queue); done: ngx_shmtx_unlock(&ctx->shpool->mutex); return NGX_DECLINED; } static void ngx_http_limit_req_delay(ngx_http_request_t *r) { ngx_event_t *wev; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "limit_req 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_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 *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_req_node_t *) &node->color; lrnt = (ngx_http_limit_req_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_req_lookup(ngx_http_limit_req_conf_t *lrcf, ngx_uint_t hash, u_char *data, size_t len, ngx_http_limit_req_node_t **lrp) { ngx_int_t rc, excess; 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 *lr; ctx = lrcf->shm_zone->data; node = ctx->sh->rbtree.root; sentinel = ctx->sh->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 { lr = (ngx_http_limit_req_node_t *) &node->color; rc = ngx_memn2cmp(data, lr->data, len, (size_t) lr->len); if (rc == 0) { tp = ngx_timeofday(); now = (ngx_msec_t) (tp->sec * 1000 + tp->msec); ms = (ngx_msec_int_t) (now - lr->last); excess = lr->excess - ctx->rate * ngx_abs(ms) / 1000 + 1000; if (excess < 0) { excess = 0; } if ((ngx_uint_t) excess > lrcf->burst) { *lrp = lr; return NGX_BUSY; } lr->excess = excess; lr->last = now; *lrp = lr; if (excess) { return NGX_AGAIN; } return NGX_OK; } node = (rc < 0) ? node->left : node->right; } while (node != sentinel && hash == node->key); break; } *lrp = NULL; return NGX_DECLINED; } static void ngx_http_limit_req_expire(ngx_http_limit_req_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_req_node_t *lr; 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->sh->queue)) { return; } q = ngx_queue_last(&ctx->sh->queue); lr = ngx_queue_data(q, ngx_http_limit_req_node_t, queue); 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_req_init_zone(ngx_shm_zone_t *shm_zone, void *data) { ngx_http_limit_req_ctx_t *octx = data; size_t len; 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->shm.name, &ctx->var, &octx->var); return NGX_ERROR; } ctx->sh = octx->sh; ctx->shpool = octx->shpool; return NGX_OK; } ctx->shpool = (ngx_slab_pool_t *) shm_zone->shm.addr; if (shm_zone->shm.exists) { ctx->sh = ctx->shpool->data; return NGX_OK; } ctx->sh = ngx_slab_alloc(ctx->shpool, sizeof(ngx_http_limit_req_shctx_t)); if (ctx->sh == NULL) { return NGX_ERROR; } ctx->shpool->data = ctx->sh; ngx_rbtree_init(&ctx->sh->rbtree, &ctx->sh->sentinel, ngx_http_limit_req_rbtree_insert_value); ngx_queue_init(&ctx->sh->queue); len = sizeof(" in limit_req zone \"\"") + shm_zone->shm.name.len; ctx->shpool->log_ctx = ngx_slab_alloc(ctx->shpool, len); if (ctx->shpool->log_ctx == NULL) { return NGX_ERROR; } ngx_sprintf(ctx->shpool->log_ctx, " in limit_req zone \"%V\"%Z", &shm_zone->shm.name); 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 NULL; } /* * set by ngx_pcalloc(): * * conf->shm_zone = NULL; * conf->burst = 0; * conf->nodelay = 0; */ conf->limit_log_level = NGX_CONF_UNSET_UINT; 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; } ngx_conf_merge_uint_value(conf->limit_log_level, prev->limit_log_level, NGX_LOG_ERR); conf->delay_log_level = (conf->limit_log_level == NGX_LOG_INFO) ? NGX_LOG_INFO : conf->limit_log_level + 1; 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) { *p = '\0'; 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 = rate * 1000 / 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 *lrcf = conf; ngx_int_t burst; ngx_str_t *value, s; ngx_uint_t i; if (lrcf->shm_zone) { return "is duplicate"; } value = cf->args->elts; burst = 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; lrcf->shm_zone = ngx_shared_memory_add(cf, &s, 0, &ngx_http_limit_req_module); if (lrcf->shm_zone == NULL) { return NGX_CONF_ERROR; } continue; } if (ngx_strncmp(value[i].data, "burst=", 6) == 0) { burst = ngx_atoi(value[i].data + 6, value[i].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, "nodelay", 7) == 0) { lrcf->nodelay = 1; continue; } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[i]); return NGX_CONF_ERROR; } if (lrcf->shm_zone == NULL) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"%V\" must have \"zone\" parameter", &cmd->name); return NGX_CONF_ERROR; } if (lrcf->shm_zone->data == NULL) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown limit_req_zone \"%V\"", &lrcf->shm_zone->shm.name); return NGX_CONF_ERROR; } lrcf->burst = burst * 1000; 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; }