Mercurial > hg > nginx
view src/http/modules/ngx_http_map_module.c @ 8018:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +0300 |
parents | ec10ce307dc0 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_uint_t hash_max_size; ngx_uint_t hash_bucket_size; } ngx_http_map_conf_t; typedef struct { ngx_hash_keys_arrays_t keys; ngx_array_t *values_hash; #if (NGX_PCRE) ngx_array_t regexes; #endif ngx_http_variable_value_t *default_value; ngx_conf_t *cf; unsigned hostnames:1; unsigned no_cacheable:1; } ngx_http_map_conf_ctx_t; typedef struct { ngx_http_map_t map; ngx_http_complex_value_t value; ngx_http_variable_value_t *default_value; ngx_uint_t hostnames; /* unsigned hostnames:1 */ } ngx_http_map_ctx_t; static int ngx_libc_cdecl ngx_http_map_cmp_dns_wildcards(const void *one, const void *two); static void *ngx_http_map_create_conf(ngx_conf_t *cf); static char *ngx_http_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf); static ngx_command_t ngx_http_map_commands[] = { { ngx_string("map"), NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2, ngx_http_map_block, NGX_HTTP_MAIN_CONF_OFFSET, 0, NULL }, { ngx_string("map_hash_max_size"), NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_HTTP_MAIN_CONF_OFFSET, offsetof(ngx_http_map_conf_t, hash_max_size), NULL }, { ngx_string("map_hash_bucket_size"), NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_HTTP_MAIN_CONF_OFFSET, offsetof(ngx_http_map_conf_t, hash_bucket_size), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_map_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ ngx_http_map_create_conf, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_map_module = { NGX_MODULE_V1, &ngx_http_map_module_ctx, /* module context */ ngx_http_map_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_map_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_http_map_ctx_t *map = (ngx_http_map_ctx_t *) data; ngx_str_t val, str; ngx_http_complex_value_t *cv; ngx_http_variable_value_t *value; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http map started"); if (ngx_http_complex_value(r, &map->value, &val) != NGX_OK) { return NGX_ERROR; } if (map->hostnames && val.len > 0 && val.data[val.len - 1] == '.') { val.len--; } value = ngx_http_map_find(r, &map->map, &val); if (value == NULL) { value = map->default_value; } if (!value->valid) { cv = (ngx_http_complex_value_t *) value->data; if (ngx_http_complex_value(r, cv, &str) != NGX_OK) { return NGX_ERROR; } v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->len = str.len; v->data = str.data; } else { *v = *value; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http map: \"%V\" \"%v\"", &val, v); return NGX_OK; } static void * ngx_http_map_create_conf(ngx_conf_t *cf) { ngx_http_map_conf_t *mcf; mcf = ngx_palloc(cf->pool, sizeof(ngx_http_map_conf_t)); if (mcf == NULL) { return NULL; } mcf->hash_max_size = NGX_CONF_UNSET_UINT; mcf->hash_bucket_size = NGX_CONF_UNSET_UINT; return mcf; } static char * ngx_http_map_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_map_conf_t *mcf = conf; char *rv; ngx_str_t *value, name; ngx_conf_t save; ngx_pool_t *pool; ngx_hash_init_t hash; ngx_http_map_ctx_t *map; ngx_http_variable_t *var; ngx_http_map_conf_ctx_t ctx; ngx_http_compile_complex_value_t ccv; if (mcf->hash_max_size == NGX_CONF_UNSET_UINT) { mcf->hash_max_size = 2048; } if (mcf->hash_bucket_size == NGX_CONF_UNSET_UINT) { mcf->hash_bucket_size = ngx_cacheline_size; } else { mcf->hash_bucket_size = ngx_align(mcf->hash_bucket_size, ngx_cacheline_size); } map = ngx_pcalloc(cf->pool, sizeof(ngx_http_map_ctx_t)); if (map == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &map->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } name = value[2]; if (name.data[0] != '$') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &name); return NGX_CONF_ERROR; } name.len--; name.data++; var = ngx_http_add_variable(cf, &name, NGX_HTTP_VAR_CHANGEABLE); if (var == NULL) { return NGX_CONF_ERROR; } var->get_handler = ngx_http_map_variable; var->data = (uintptr_t) map; pool = ngx_create_pool(NGX_DEFAULT_POOL_SIZE, cf->log); if (pool == NULL) { return NGX_CONF_ERROR; } ctx.keys.pool = cf->pool; ctx.keys.temp_pool = pool; if (ngx_hash_keys_array_init(&ctx.keys, NGX_HASH_LARGE) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } ctx.values_hash = ngx_pcalloc(pool, sizeof(ngx_array_t) * ctx.keys.hsize); if (ctx.values_hash == NULL) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } #if (NGX_PCRE) if (ngx_array_init(&ctx.regexes, cf->pool, 2, sizeof(ngx_http_map_regex_t)) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } #endif ctx.default_value = NULL; ctx.cf = &save; ctx.hostnames = 0; ctx.no_cacheable = 0; save = *cf; cf->pool = pool; cf->ctx = &ctx; cf->handler = ngx_http_map; cf->handler_conf = conf; rv = ngx_conf_parse(cf, NULL); *cf = save; if (rv != NGX_CONF_OK) { ngx_destroy_pool(pool); return rv; } if (ctx.no_cacheable) { var->flags |= NGX_HTTP_VAR_NOCACHEABLE; } map->default_value = ctx.default_value ? ctx.default_value: &ngx_http_variable_null_value; map->hostnames = ctx.hostnames; hash.key = ngx_hash_key_lc; hash.max_size = mcf->hash_max_size; hash.bucket_size = mcf->hash_bucket_size; hash.name = "map_hash"; hash.pool = cf->pool; if (ctx.keys.keys.nelts) { hash.hash = &map->map.hash.hash; hash.temp_pool = NULL; if (ngx_hash_init(&hash, ctx.keys.keys.elts, ctx.keys.keys.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } } if (ctx.keys.dns_wc_head.nelts) { ngx_qsort(ctx.keys.dns_wc_head.elts, (size_t) ctx.keys.dns_wc_head.nelts, sizeof(ngx_hash_key_t), ngx_http_map_cmp_dns_wildcards); hash.hash = NULL; hash.temp_pool = pool; if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_head.elts, ctx.keys.dns_wc_head.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } map->map.hash.wc_head = (ngx_hash_wildcard_t *) hash.hash; } if (ctx.keys.dns_wc_tail.nelts) { ngx_qsort(ctx.keys.dns_wc_tail.elts, (size_t) ctx.keys.dns_wc_tail.nelts, sizeof(ngx_hash_key_t), ngx_http_map_cmp_dns_wildcards); hash.hash = NULL; hash.temp_pool = pool; if (ngx_hash_wildcard_init(&hash, ctx.keys.dns_wc_tail.elts, ctx.keys.dns_wc_tail.nelts) != NGX_OK) { ngx_destroy_pool(pool); return NGX_CONF_ERROR; } map->map.hash.wc_tail = (ngx_hash_wildcard_t *) hash.hash; } #if (NGX_PCRE) if (ctx.regexes.nelts) { map->map.regex = ctx.regexes.elts; map->map.nregex = ctx.regexes.nelts; } #endif ngx_destroy_pool(pool); return rv; } static int ngx_libc_cdecl ngx_http_map_cmp_dns_wildcards(const void *one, const void *two) { ngx_hash_key_t *first, *second; first = (ngx_hash_key_t *) one; second = (ngx_hash_key_t *) two; return ngx_dns_strcmp(first->key.data, second->key.data); } static char * ngx_http_map(ngx_conf_t *cf, ngx_command_t *dummy, void *conf) { u_char *data; size_t len; ngx_int_t rv; ngx_str_t *value, v; ngx_uint_t i, key; ngx_http_map_conf_ctx_t *ctx; ngx_http_complex_value_t cv, *cvp; ngx_http_variable_value_t *var, **vp; ngx_http_compile_complex_value_t ccv; ctx = cf->ctx; value = cf->args->elts; if (cf->args->nelts == 1 && ngx_strcmp(value[0].data, "hostnames") == 0) { ctx->hostnames = 1; return NGX_CONF_OK; } if (cf->args->nelts == 1 && ngx_strcmp(value[0].data, "volatile") == 0) { ctx->no_cacheable = 1; return NGX_CONF_OK; } if (cf->args->nelts != 2) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid number of the map parameters"); return NGX_CONF_ERROR; } if (ngx_strcmp(value[0].data, "include") == 0) { return ngx_conf_include(cf, dummy, conf); } key = 0; for (i = 0; i < value[1].len; i++) { key = ngx_hash(key, value[1].data[i]); } key %= ctx->keys.hsize; vp = ctx->values_hash[key].elts; if (vp) { for (i = 0; i < ctx->values_hash[key].nelts; i++) { if (vp[i]->valid) { data = vp[i]->data; len = vp[i]->len; } else { cvp = (ngx_http_complex_value_t *) vp[i]->data; data = cvp->value.data; len = cvp->value.len; } if (value[1].len != len) { continue; } if (ngx_strncmp(value[1].data, data, len) == 0) { var = vp[i]; goto found; } } } else { if (ngx_array_init(&ctx->values_hash[key], cf->pool, 4, sizeof(ngx_http_variable_value_t *)) != NGX_OK) { return NGX_CONF_ERROR; } } var = ngx_palloc(ctx->keys.pool, sizeof(ngx_http_variable_value_t)); if (var == NULL) { return NGX_CONF_ERROR; } v.len = value[1].len; v.data = ngx_pstrdup(ctx->keys.pool, &value[1]); if (v.data == NULL) { return NGX_CONF_ERROR; } ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = ctx->cf; ccv.value = &v; ccv.complex_value = &cv; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } if (cv.lengths != NULL) { cvp = ngx_palloc(ctx->keys.pool, sizeof(ngx_http_complex_value_t)); if (cvp == NULL) { return NGX_CONF_ERROR; } *cvp = cv; var->len = 0; var->data = (u_char *) cvp; var->valid = 0; } else { var->len = v.len; var->data = v.data; var->valid = 1; } var->no_cacheable = 0; var->not_found = 0; vp = ngx_array_push(&ctx->values_hash[key]); if (vp == NULL) { return NGX_CONF_ERROR; } *vp = var; found: if (ngx_strcmp(value[0].data, "default") == 0) { if (ctx->default_value) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate default map parameter"); return NGX_CONF_ERROR; } ctx->default_value = var; return NGX_CONF_OK; } #if (NGX_PCRE) if (value[0].len && value[0].data[0] == '~') { ngx_regex_compile_t rc; ngx_http_map_regex_t *regex; u_char errstr[NGX_MAX_CONF_ERRSTR]; regex = ngx_array_push(&ctx->regexes); if (regex == NULL) { return NGX_CONF_ERROR; } value[0].len--; value[0].data++; ngx_memzero(&rc, sizeof(ngx_regex_compile_t)); if (value[0].data[0] == '*') { value[0].len--; value[0].data++; rc.options = NGX_REGEX_CASELESS; } rc.pattern = value[0]; rc.err.len = NGX_MAX_CONF_ERRSTR; rc.err.data = errstr; regex->regex = ngx_http_regex_compile(ctx->cf, &rc); if (regex->regex == NULL) { return NGX_CONF_ERROR; } regex->value = var; return NGX_CONF_OK; } #endif if (value[0].len && value[0].data[0] == '\\') { value[0].len--; value[0].data++; } rv = ngx_hash_add_key(&ctx->keys, &value[0], var, (ctx->hostnames) ? NGX_HASH_WILDCARD_KEY : 0); if (rv == NGX_OK) { return NGX_CONF_OK; } if (rv == NGX_DECLINED) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid hostname or wildcard \"%V\"", &value[0]); } if (rv == NGX_BUSY) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "conflicting parameter \"%V\"", &value[0]); } return NGX_CONF_ERROR; }