Mercurial > hg > nginx
view src/http/modules/ngx_http_map_module.c @ 5356:acd51b0f6fd4
Disable symlinks: use O_PATH to open path components.
It was introduced in Linux 2.6.39, glibc 2.14 and allows to obtain
file descriptors without actually opening files. Thus made it possible
to traverse path with openat() syscalls without the need to have read
permissions for path components. It is effectively emulates O_SEARCH
which is missing on Linux.
O_PATH is used in combination with O_RDONLY. The last one is ignored
if O_PATH is used, but it allows nginx to not fail when it was built on
modern system (i.e. glibc 2.14+) and run with a kernel older than 2.6.39.
Then O_PATH is unknown to the kernel and ignored, while O_RDONLY is used.
Sadly, fstat() is not working with O_PATH descriptors till Linux 3.6.
As a workaround we fallback to fstatat() with the AT_EMPTY_PATH flag
that was introduced at the same time as O_PATH.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Mon, 02 Sep 2013 08:07:59 +0400 |
parents | 5482671df278 |
children | 79b9101cecf4 |
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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; ngx_array_t var_values; #if (NGX_PCRE) ngx_array_t regexes; #endif ngx_http_variable_value_t *default_value; ngx_conf_t *cf; ngx_uint_t hostnames; /* unsigned hostnames: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; 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) { value = ngx_http_get_flushed_variable(r, (ngx_uint_t) value->data); if (value == NULL || value->not_found) { value = &ngx_http_variable_null_value; } } *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_array_init(&ctx.var_values, cf->pool, 2, sizeof(ngx_http_variable_value_t)) != NGX_OK) { 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; 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; } 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) { ngx_int_t rc, index; ngx_str_t *value, name; ngx_uint_t i, key; ngx_http_map_conf_ctx_t *ctx; ngx_http_variable_value_t *var, **vp; 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; } else 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); } if (value[1].data[0] == '$') { name = value[1]; name.len--; name.data++; index = ngx_http_get_variable_index(ctx->cf, &name); if (index == NGX_ERROR) { return NGX_CONF_ERROR; } var = ctx->var_values.elts; for (i = 0; i < ctx->var_values.nelts; i++) { if (index == (ngx_int_t) var[i].data) { var = &var[i]; goto found; } } var = ngx_array_push(&ctx->var_values); if (var == NULL) { return NGX_CONF_ERROR; } var->valid = 0; var->no_cacheable = 0; var->not_found = 0; var->len = 0; var->data = (u_char *) index; goto found; } 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 (value[1].len != (size_t) vp[i]->len) { continue; } if (ngx_strncmp(value[1].data, vp[i]->data, value[1].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; } var->len = value[1].len; var->data = ngx_pstrdup(ctx->keys.pool, &value[1]); if (var->data == NULL) { return NGX_CONF_ERROR; } 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++; } rc = ngx_hash_add_key(&ctx->keys, &value[0], var, (ctx->hostnames) ? NGX_HASH_WILDCARD_KEY : 0); if (rc == NGX_OK) { return NGX_CONF_OK; } if (rc == NGX_DECLINED) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid hostname or wildcard \"%V\"", &value[0]); } if (rc == NGX_BUSY) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "conflicting parameter \"%V\"", &value[0]); } return NGX_CONF_ERROR; }