Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_random_index_module.c @ 6133:af7eba90645d
Win32: shared memory base addresses and remapping.
Two mechanisms are implemented to make it possible to store pointers
in shared memory on Windows, in particular on Windows Vista and later
versions with ASLR:
- The ngx_shm_remap() function added to allow remapping of a shared memory
zone to the address originally used for it in the master process. While
important, it doesn't solve the problem by itself as in many cases it's
not possible to use the address because of conflicts with other
allocations.
- We now create mappings at the same address in all processes by starting
mappings at predefined addresses normally unused by newborn processes.
These two mechanisms combined allow to use shared memory on Windows
almost without problems, including reloads.
Based on the patch by Sergey Brester:
http://mailman.nginx.org/pipermail/nginx-devel/2015-April/006836.html
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 27 Apr 2015 18:25:42 +0300 |
parents | 778ef9c3fd2d |
children | 47daf95d0138 |
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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 = NGX_DIR_MASK_LEN; #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 " \"%s\" 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; }