Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_random_index_module.c @ 7514:319242d2ddc9
Upstream: background cache update before cache send (ticket #1782).
In case of filter finalization, essential request fields like r->uri,
r->args etc could be changed, which affected the cache update subrequest.
Also, after filter finalization r->cache could be set to NULL, leading to
null pointer dereference in ngx_http_upstream_cache_background_update().
The fix is to create background cache update subrequest before sending the
cached response.
Since initial introduction in 1aeaae6e9446 (1.11.10) background cache update
subrequest was created after sending the cached response because otherwise it
blocked the parent request output. In 9552758a786e (1.13.1) background
subrequests were introduced to eliminate the delay before sending the final
part of the cached response. This also made it possible to create the
background cache update subrequest before sending the response.
Note that creating the subrequest earlier does not change the fact that in case
of filter finalization the background cache update subrequest will likely not
have enough time to successfully update the cache entry. Filter finalization
leads to the main request termination as soon the current iteration of request
processing is complete.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 03 Jun 2019 20:33:26 +0300 |
parents | 061ec464813f |
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_flag_t enable; } ngx_http_random_index_loc_conf_t; #define NGX_HTTP_RANDOM_INDEX_PREALLOCATE 50 static ngx_int_t ngx_http_random_index_error(ngx_http_request_t *r, ngx_dir_t *dir, ngx_str_t *name); static ngx_int_t ngx_http_random_index_init(ngx_conf_t *cf); static void *ngx_http_random_index_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_random_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_command_t ngx_http_random_index_commands[] = { { ngx_string("random_index"), NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_random_index_loc_conf_t, enable), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_random_index_module_ctx = { NULL, /* preconfiguration */ ngx_http_random_index_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_random_index_create_loc_conf, /* create location configuration */ ngx_http_random_index_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_random_index_module = { NGX_MODULE_V1, &ngx_http_random_index_module_ctx, /* module context */ ngx_http_random_index_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_random_index_handler(ngx_http_request_t *r) { u_char *last, *filename; size_t len, allocated, root; ngx_err_t err; ngx_int_t rc; ngx_str_t path, uri, *name; ngx_dir_t dir; ngx_uint_t n, level; ngx_array_t names; ngx_http_random_index_loc_conf_t *rlcf; if (r->uri.data[r->uri.len - 1] != '/') { return NGX_DECLINED; } if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD|NGX_HTTP_POST))) { return NGX_DECLINED; } rlcf = ngx_http_get_module_loc_conf(r, ngx_http_random_index_module); if (!rlcf->enable) { return NGX_DECLINED; } #if (NGX_HAVE_D_TYPE) len = 0; #else len = NGX_HTTP_RANDOM_INDEX_PREALLOCATE; #endif last = ngx_http_map_uri_to_path(r, &path, &root, len); if (last == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } allocated = path.len; path.len = last - path.data - 1; path.data[path.len] = '\0'; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http random index: \"%s\"", path.data); if (ngx_open_dir(&path, &dir) == NGX_ERROR) { err = ngx_errno; if (err == NGX_ENOENT || err == NGX_ENOTDIR || err == NGX_ENAMETOOLONG) { level = NGX_LOG_ERR; rc = NGX_HTTP_NOT_FOUND; } else if (err == NGX_EACCES) { level = NGX_LOG_ERR; rc = NGX_HTTP_FORBIDDEN; } else { level = NGX_LOG_CRIT; rc = NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_log_error(level, r->connection->log, err, ngx_open_dir_n " \"%s\" failed", path.data); return rc; } if (ngx_array_init(&names, r->pool, 32, sizeof(ngx_str_t)) != NGX_OK) { return ngx_http_random_index_error(r, &dir, &path); } filename = path.data; filename[path.len] = '/'; for ( ;; ) { ngx_set_errno(0); if (ngx_read_dir(&dir) == NGX_ERROR) { err = ngx_errno; if (err != NGX_ENOMOREFILES) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, err, ngx_read_dir_n " \"%V\" failed", &path); return ngx_http_random_index_error(r, &dir, &path); } break; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http random index file: \"%s\"", ngx_de_name(&dir)); if (ngx_de_name(&dir)[0] == '.') { continue; } len = ngx_de_namelen(&dir); if (dir.type == 0 || ngx_de_is_link(&dir)) { /* 1 byte for '/' and 1 byte for terminating '\0' */ if (path.len + 1 + len + 1 > allocated) { allocated = path.len + 1 + len + 1 + NGX_HTTP_RANDOM_INDEX_PREALLOCATE; filename = ngx_pnalloc(r->pool, allocated); if (filename == NULL) { return ngx_http_random_index_error(r, &dir, &path); } last = ngx_cpystrn(filename, path.data, path.len + 1); *last++ = '/'; } ngx_cpystrn(last, ngx_de_name(&dir), len + 1); if (ngx_de_info(filename, &dir) == NGX_FILE_ERROR) { err = ngx_errno; if (err != NGX_ENOENT) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, err, ngx_de_info_n " \"%s\" failed", filename); return ngx_http_random_index_error(r, &dir, &path); } if (ngx_de_link_info(filename, &dir) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno, ngx_de_link_info_n " \"%s\" failed", filename); return ngx_http_random_index_error(r, &dir, &path); } } } if (!ngx_de_is_file(&dir)) { continue; } name = ngx_array_push(&names); if (name == NULL) { return ngx_http_random_index_error(r, &dir, &path); } name->len = len; name->data = ngx_pnalloc(r->pool, len); if (name->data == NULL) { return ngx_http_random_index_error(r, &dir, &path); } ngx_memcpy(name->data, ngx_de_name(&dir), len); } if (ngx_close_dir(&dir) == NGX_ERROR) { ngx_log_error(NGX_LOG_ALERT, r->connection->log, ngx_errno, ngx_close_dir_n " \"%V\" failed", &path); } n = names.nelts; if (n == 0) { return NGX_DECLINED; } name = names.elts; n = (ngx_uint_t) (((uint64_t) ngx_random() * n) / 0x80000000); uri.len = r->uri.len + name[n].len; uri.data = ngx_pnalloc(r->pool, uri.len); if (uri.data == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } last = ngx_copy(uri.data, r->uri.data, r->uri.len); ngx_memcpy(last, name[n].data, name[n].len); return ngx_http_internal_redirect(r, &uri, &r->args); } static ngx_int_t ngx_http_random_index_error(ngx_http_request_t *r, ngx_dir_t *dir, ngx_str_t *name) { if (ngx_close_dir(dir) == NGX_ERROR) { ngx_log_error(NGX_LOG_ALERT, r->connection->log, ngx_errno, ngx_close_dir_n " \"%V\" failed", name); } return NGX_HTTP_INTERNAL_SERVER_ERROR; } static void * ngx_http_random_index_create_loc_conf(ngx_conf_t *cf) { ngx_http_random_index_loc_conf_t *conf; conf = ngx_palloc(cf->pool, sizeof(ngx_http_random_index_loc_conf_t)); if (conf == NULL) { return NULL; } conf->enable = NGX_CONF_UNSET; return conf; } static char * ngx_http_random_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_random_index_loc_conf_t *prev = parent; ngx_http_random_index_loc_conf_t *conf = child; ngx_conf_merge_value(conf->enable, prev->enable, 0); return NGX_CONF_OK; } static ngx_int_t ngx_http_random_index_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_CONTENT_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_random_index_handler; return NGX_OK; }