http 模块配置解析

2015-08-16 21:09:44   最后更新: 2015-09-28 12:52:14   访问数量:1193




 

要理解 HTTP 模块配置解析的过程,首先需要对 nginx 的配置文件结构做一个了解

nginx 的配置文件是用树状结构组织的,每个 NGX_CORE_MODULE 作为根统领着其下的所有配置项

而如下图所示,HTTP 模块的配置被分成了 main、server、location 三层

 

 

整个 nginx 配置解析的过程其实就是这棵树的深度遍历过程

而遍历 HTTP 子树的函数就是下面要介绍的 ngx_http_block

 

当我们需要使用 http 模块的时候,我们需要在配置文件中加入 http 配置块:

http { // http 配置块 {{{ include mime.types; default_type application/octet-stream; #log_format main '$remote_addr - $remote_user [$time_local] "$request" ' # '$status $body_bytes_sent "$http_referer" ' # '"$http_user_agent" "$http_x_forwarded_for"'; #access_log logs/access.log main; sendfile on; #tcp_nopush on; #keepalive_timeout 0; keepalive_timeout 65; #gzip on; server { listen 8001; server_name localhost; #autoindex on; #charset koi8-r; #access_log logs/host.access.log main; location / { root /var/www/; index index.html index.htm index.php; } location /nginx_status { # Turn on nginx stats stub_status on; # I do not need logs for stats access_log off; # Security: Only allow access from 192.168.1.100 IP # #allow 192.168.1.100; # Send rest of the world to /dev/null # #deny all; } #error_page 404 /404.html; # redirect server error pages to the static page /50x.html # #error_page 500 502 503 504 /50x.html; #location = /50x.html { # root html; #} # proxy the PHP scripts to Apache listening on 127.0.0.1:80 # #location ~ \.php$ { # proxy_pass http://127.0.0.1; #} # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000 location ~ \.php$ { root html; # fastcgi_pass unix:/var/run/php5-fpm.sock; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME /var/www$fastcgi_script_name; include fastcgi_params; } # deny access to .htaccess files, if Apache's document root # concurs with nginx's one # #location ~ /\.ht { # deny all; #} } # another virtual host using mix of IP-, name-, and port-based configuration # #server { # listen 8000; # listen somename:8080; # server_name somename alias another.alias; # location / { # root html; # index index.html index.htm; # } #} # HTTPS server # #server { # listen 443 ssl; # server_name localhost; # ssl_certificate cert.pem; # ssl_certificate_key cert.key; # ssl_session_cache shared:SSL:1m; # ssl_session_timeout 5m; # ssl_ciphers HIGH:!aNULL:!MD5; # ssl_prefer_server_ciphers on; # location / { # root html; # index index.html index.htm; # } #} } // }}}

 

 

在 http 配置块中,我们配置了 http 连接相关的信息,HTTP 框架也正是从这里启动的

 

在 nginx 初始化的过程中,执行了 ngx_init_cycle 函数,其中进行了配置文件解析,调用了 ngx_conf_parse 函数

配置文件解析

函数 ngx_conf_handler 根据配置项的 command 调用了对应的 set 回调函数

// static ngx_int_t ngx_conf_handler(ngx_conf_t *cf, ngx_int_t last) // 配置项解析 {{{ static ngx_int_t ngx_conf_handler(ngx_conf_t *cf, ngx_int_t last) { char *rv; void *conf, **confp; ngx_uint_t i, found; ngx_str_t *name; ngx_command_t *cmd; name = cf->args->elts; found = 0; for (i = 0; ngx_modules[i]; i++) { cmd = ngx_modules[i]->commands; if (cmd == NULL) { continue; } for ( /* void */ ; cmd->name.len; cmd++) { if (name->len != cmd->name.len) { continue; } if (ngx_strcmp(name->data, cmd->name.data) != 0) { continue; } found = 1; if (ngx_modules[i]->type != NGX_CONF_MODULE && ngx_modules[i]->type != cf->module_type) { continue; } /* is the directive's location right ? */ if (!(cmd->type & cf->cmd_type)) { continue; } if (!(cmd->type & NGX_CONF_BLOCK) && last != NGX_OK) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "directive \"%s\" is not terminated by \";\"", name->data); return NGX_ERROR; } if ((cmd->type & NGX_CONF_BLOCK) && last != NGX_CONF_BLOCK_START) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "directive \"%s\" has no opening \"{\"", name->data); return NGX_ERROR; } /* is the directive's argument count right ? */ if (!(cmd->type & NGX_CONF_ANY)) { if (cmd->type & NGX_CONF_FLAG) { if (cf->args->nelts != 2) { goto invalid; } } else if (cmd->type & NGX_CONF_1MORE) { if (cf->args->nelts < 2) { goto invalid; } } else if (cmd->type & NGX_CONF_2MORE) { if (cf->args->nelts < 3) { goto invalid; } } else if (cf->args->nelts > NGX_CONF_MAX_ARGS) { goto invalid; } else if (!(cmd->type & argument_number[cf->args->nelts - 1])) { goto invalid; } } /* set up the directive's configuration context */ conf = NULL; if (cmd->type & NGX_DIRECT_CONF) { conf = ((void **) cf->ctx)[ngx_modules[i]->index]; } else if (cmd->type & NGX_MAIN_CONF) { conf = &(((void **) cf->ctx)[ngx_modules[i]->index]); } else if (cf->ctx) { confp = *(void **) ((char *) cf->ctx + cmd->conf); if (confp) { conf = confp[ngx_modules[i]->ctx_index]; } } // 调用命令创建回调函数 rv = cmd->set(cf, cmd, conf); if (rv == NGX_CONF_OK) { return NGX_OK; } if (rv == NGX_CONF_ERROR) { return NGX_ERROR; } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"%s\" directive %s", name->data, rv); return NGX_ERROR; } } if (found) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"%s\" directive is not allowed here", name->data); return NGX_ERROR; } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown directive \"%s\"", name->data); return NGX_ERROR; invalid: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid number of arguments in \"%s\" directive", name->data); return NGX_ERROR; } // }}}

 

 

阅读各模块的 ngx_command_t 命令配置结构,可以找到:

// static ngx_command_t ngx_http_commands // http 模块命令结构 {{{ static ngx_command_t ngx_http_commands[] = { { ngx_string("http"), NGX_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_NOARGS, ngx_http_block, 0, 0, NULL }, ngx_null_command }; // }}}

 

 

 

 

在解析到 http 配置块时,执行了对应的 set 回调函数 ngx_http_block

// static char * ngx_http_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) // "http" 配置块解析 {{{ static char * ngx_http_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { char *rv; ngx_uint_t mi, m, s; ngx_conf_t pcf; ngx_http_module_t *module; ngx_http_conf_ctx_t *ctx; ngx_http_core_loc_conf_t *clcf; ngx_http_core_srv_conf_t **cscfp; ngx_http_core_main_conf_t *cmcf; /* the main http context */ ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } // 创建 http 配置结构,保存所有 http 模块的配置信息 *(ngx_http_conf_ctx_t **) conf = ctx; /* count the number of the http modules and set up their indices */ ngx_http_max_module = 0; for (m = 0; ngx_modules[m]; m++) { if (ngx_modules[m]->type != NGX_HTTP_MODULE) { continue; } // 重新设定 HTTP 模块序号 ngx_modules[m]->ctx_index = ngx_http_max_module++; } /* the http main_conf context, it is the same in the all http contexts */ ctx->main_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module); if (ctx->main_conf == NULL) { return NGX_CONF_ERROR; } /* * the http null srv_conf context, it is used to merge * the server{}s' srv_conf's */ ctx->srv_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module); if (ctx->srv_conf == NULL) { return NGX_CONF_ERROR; } /* * the http null loc_conf context, it is used to merge * the server{}s' loc_conf's */ ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module); if (ctx->loc_conf == NULL) { return NGX_CONF_ERROR; } /* * create the main_conf's, the null srv_conf's, and the null loc_conf's * of the all http modules */ for (m = 0; ngx_modules[m]; m++) { if (ngx_modules[m]->type != NGX_HTTP_MODULE) { continue; } module = ngx_modules[m]->ctx; mi = ngx_modules[m]->ctx_index; if (module->create_main_conf) { // 调用每个模块的 create_main_conf 回调函数 // 创建自己的 main_conf // // ngx_http_core_module ngx_http_core_create_main_conf // ngx_http_log_module ngx_http_log_create_main_conf // ngx_http_upstream_module ngx_http_upstream_create_main_conf // ngx_http_map_module ngx_http_map_create_conf // ngx_http_ssi_filter_module ngx_http_ssi_create_main_conf // ngx_http_charset_filter_module ngx_http_charset_create_main_conf ctx->main_conf[mi] = module->create_main_conf(cf); if (ctx->main_conf[mi] == NULL) { return NGX_CONF_ERROR; } } if (module->create_srv_conf) { // 调用每个模块的 create_srv_conf 回调函数 // 创建自己的 srv_conf // // ngx_http_core_module ngx_http_core_create_srv_conf // ngx_http_ssl_module ngx_http_ssl_create_srv_conf // ngx_http_upstream_hash_module ngx_http_upstream_hash_create_conf // ngx_http_upstream_least_conn_module ngx_http_upstream_least_conn_create_conf // ngx_http_upstream_keepalive_module ngx_http_upstream_keepalive_create_conf ctx->srv_conf[mi] = module->create_srv_conf(cf); if (ctx->srv_conf[mi] == NULL) { return NGX_CONF_ERROR; } } if (module->create_loc_conf) { // 调用每个模块的 create_loc_conf 回调函数 // 创建自己的 loc_conf // // ngx_http_core_module ngx_http_core_create_loc_conf // ngx_http_log_module ngx_http_log_create_loc_conf // ngx_http_gzip_static_module ngx_http_gzip_static_create_conf // ngx_http_autoindex_module ngx_http_autoindex_create_loc_conf // ngx_http_index_module ngx_http_index_create_loc_conf // ngx_http_auth_basic_module ngx_http_auth_basic_create_loc_conf // ngx_http_access_module ngx_http_access_create_loc_conf // ngx_http_limit_conn_module ngx_http_limit_conn_create_conf // ngx_http_limit_req_module ngx_http_limit_req_create_conf // ngx_http_referer_module ngx_http_referer_create_conf // ngx_http_rewrite_module ngx_http_rewrite_create_loc_conf // ngx_http_proxy_module ngx_http_proxy_create_loc_conf // ngx_http_fastcgi_module ngx_http_fastcgi_create_loc_conf // ngx_http_uwsgi_module ngx_http_uwsgi_create_loc_conf // ngx_http_scgi_module ngx_http_scgi_create_loc_conf // ngx_http_memcached_module ngx_http_memcached_create_loc_conf // ngx_http_browser_module ngx_http_browser_create_conf // ngx_http_gzip_filter_module ngx_http_gzip_create_conf // ngx_http_ssi_filter_module ngx_http_ssi_create_loc_conf // ngx_http_charset_filter_module ngx_http_charset_create_loc_conf // ngx_http_userid_filter_module ngx_http_userid_create_conf // ngx_http_headers_filter_module ngx_http_headers_create_conf // ngx_http_copy_filter_module ngx_http_copy_filter_create_conf ctx->loc_conf[mi] = module->create_loc_conf(cf); if (ctx->loc_conf[mi] == NULL) { return NGX_CONF_ERROR; } } } pcf = *cf; cf->ctx = ctx; for (m = 0; ngx_modules[m]; m++) { if (ngx_modules[m]->type != NGX_HTTP_MODULE) { continue; } module = ngx_modules[m]->ctx; if (module->preconfiguration) { // 调用每个模块的 preconfiguration 回调函数 // // ngx_http_core_module ngx_http_core_preconfiguration // ngx_http_upstream_module ngx_http_upstream_add_variables // ngx_http_ssl_module ngx_http_ssl_add_variables // ngx_http_proxy_module ngx_http_proxy_add_variables // ngx_http_fastcgi_module ngx_http_fastcgi_add_variables // ngx_http_browser_module ngx_http_browser_add_variable // ngx_http_stub_status_module ngx_http_stub_status_add_variables // ngx_http_gzip_filter_module ngx_http_gzip_add_variables // ngx_http_ssi_filter_module ngx_http_ssi_preconfiguration // ngx_http_userid_filter_module ngx_http_userid_add_variables if (module->preconfiguration(cf) != NGX_OK) { return NGX_CONF_ERROR; } } } /* parse inside the http{} block */ cf->module_type = NGX_HTTP_MODULE; cf->cmd_type = NGX_HTTP_MAIN_CONF; rv = ngx_conf_parse(cf, NULL); if (rv != NGX_CONF_OK) { goto failed; } /* * init http{} main_conf's, merge the server{}s' srv_conf's * and its location{}s' loc_conf's */ cmcf = ctx->main_conf[ngx_http_core_module.ctx_index]; cscfp = cmcf->servers.elts; for (m = 0; ngx_modules[m]; m++) { if (ngx_modules[m]->type != NGX_HTTP_MODULE) { continue; } module = ngx_modules[m]->ctx; mi = ngx_modules[m]->ctx_index; /* init http{} main_conf's */ if (module->init_main_conf) { // 调用每个模块的 init_main_conf 回调函数 // 初始化自己的 main_conf // // ngx_http_core_module ngx_http_core_init_main_conf // ngx_http_upstream_module ngx_http_upstream_init_main_conf // ngx_http_ssi_filter_module ngx_http_ssi_init_main_conf rv = module->init_main_conf(cf, ctx->main_conf[mi]); if (rv != NGX_CONF_OK) { goto failed; } } // 合并同名配置项 rv = ngx_http_merge_servers(cf, cmcf, module, mi); if (rv != NGX_CONF_OK) { goto failed; } } /* create location trees */ for (s = 0; s < cmcf->servers.nelts; s++) { clcf = cscfp[s]->ctx->loc_conf[ngx_http_core_module.ctx_index]; if (ngx_http_init_locations(cf, cscfp[s], clcf) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_http_init_static_location_trees(cf, clcf) != NGX_OK) { return NGX_CONF_ERROR; } } if (ngx_http_init_phases(cf, cmcf) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_http_init_headers_in_hash(cf, cmcf) != NGX_OK) { return NGX_CONF_ERROR; } for (m = 0; ngx_modules[m]; m++) { if (ngx_modules[m]->type != NGX_HTTP_MODULE) { continue; } module = ngx_modules[m]->ctx; if (module->postconfiguration) { // 调用每个 HTTP 模块的 postconfiguration 回调函数 // // ngx_http_log_module ngx_http_log_init // ngx_http_static_module ngx_http_static_init // ngx_http_gzip_static_module ngx_http_gzip_static_init // ngx_http_autoindex_module ngx_http_autoindex_init // ngx_http_index_module ngx_http_index_init // ngx_http_auth_basic_module ngx_http_auth_basic_init // ngx_http_access_module ngx_http_access_init // ngx_http_limit_conn_module ngx_http_limit_conn_init // ngx_http_limit_req_module ngx_http_limit_req_init // ngx_http_rewrite_module ngx_http_rewrite_init // ngx_http_ssl_module ngx_http_ssl_init // ngx_http_write_filter_module ngx_http_write_filter_init // ngx_http_header_filter_module ngx_http_header_filter_init // ngx_http_chunked_filter_module ngx_http_chunked_filter_init // ngx_http_range_body_filter_module ngx_http_range_body_filter_init // ngx_http_gzip_filter_module ngx_http_gzip_filter_init // ngx_http_postpone_filter_module ngx_http_postpone_filter_init // ngx_http_ssi_filter_module ngx_http_ssi_filter_init // ngx_http_charset_filter_module ngx_http_charset_postconfiguration // ngx_http_userid_filter_module ngx_http_userid_init // ngx_http_headers_filter_module ngx_http_headers_filter_init // ngx_http_copy_filter_module ngx_http_copy_filter_init // ngx_http_range_body_filter_module ngx_http_range_body_filter_init // ngx_http_not_modified_filter_module ngx_http_not_modified_filter_init if (module->postconfiguration(cf) != NGX_OK) { return NGX_CONF_ERROR; } } } // 初始化所有的变量 // 不仅包括HTTP core模块的变量 // 也包括其他的HTTP模块导出的变量,以及配置文件中使用 set 命令设置的变量 // 这里的初始化包括初始化hash表,以及初始化数组索引 if (ngx_http_variables_init_vars(cf) != NGX_OK) { return NGX_CONF_ERROR; } /* * http{}'s cf->ctx was needed while the configuration merging * and in postconfiguration process */ *cf = pcf; // 初始化 phase_engine 结构 if (ngx_http_init_phase_handlers(cf, cmcf) != NGX_OK) { return NGX_CONF_ERROR; } /* optimize the lists of ports, addresses and server names */ // 创建 http 连接,并设置为监听状态 if (ngx_http_optimize_servers(cf, cmcf, cmcf->ports) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; failed: *cf = pcf; return rv; } // }}}

 

 

这个函数中,为所有的 http 模块都分配并创建了配置结构,同时,调用了每个模块相应的初始化回调

最后,调用 ngx_http_optimize_servers 创建了 http 连接,加入 cycle 的监听数组,并设为监听状态

 

nginx 配置文件对 http 模块的配置分为三层:main、sever、location,因此,http 模块上下文 ngx_http_module_t 中定义了以下六个回调函数,用来创建和保存配置信息

  1. create_main_conf
  2. init_main_conf
  3. create_srv_conf
  4. merge_srv_conf
  5. create_loc_conf
  6. merge_loc_conf

 

在 ngx_http_block 中,循环调用了所有 NGX_HTTP_MODULE 的这六个回调函数,创建相关的配置结构

 

在调用所有 HTTP 模块的 create_main_conf、create_srv_conf、create_loc_conf 后,所有需要配置结构的模块都完成了配置结构的创建,于是在调用所有模块的 preconfiguration 回调函数后,配置解析工作正式展开

通过调用 ngx_conf_parse 函数,开始了 http 配置块的解析,并通过解析到的命令调用相应的函数

在首个 NGX_HTTP_MODULE ngx_http_core_module 的 ngx_command_t 域中包含了大量的配置指令,它们都是在http{}块中出现的,其中包括两个重要的指令:

{ ngx_string("listen"), NGX_HTTP_SRV_CONF|NGX_CONF_1MORE, ngx_http_core_listen, NGX_HTTP_SRV_CONF_OFFSET, 0, NULL }, { ngx_string("server"), NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_NOARGS, ngx_http_core_server, 0, 0, NULL }, { ngx_string("location"), NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE12, ngx_http_core_location, NGX_HTTP_SRV_CONF_OFFSET, 0, NULL },

 

 

这里配置了 listen、server 与 location 块的解析函数 ngx_http_core_listen、ngx_http_core_server 和 ngx_http_core_location

listen 的解析是一个很重要的过程,他获取了 IP、port 及虚拟主机的相关配置,这个部分我们下一篇博客中进行详细介绍

 

// static char * // ngx_http_core_server(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy) // http server 块解析 {{{ static char * ngx_http_core_server(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy) { char *rv; void *mconf; ngx_uint_t i; ngx_conf_t pcf; ngx_http_module_t *module; struct sockaddr_in *sin; ngx_http_conf_ctx_t *ctx, *http_ctx; ngx_http_listen_opt_t lsopt; ngx_http_core_srv_conf_t *cscf, **cscfp; ngx_http_core_main_conf_t *cmcf; ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } http_ctx = cf->ctx; ctx->main_conf = http_ctx->main_conf; /* the server{}'s srv_conf */ // 为所有 HTTP 模块分配空间存储 srv_conf ctx->srv_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module); if (ctx->srv_conf == NULL) { return NGX_CONF_ERROR; } /* the server{}'s loc_conf */ // 为所有 HTTP 模块分配空间存储 loc_conf ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module); if (ctx->loc_conf == NULL) { return NGX_CONF_ERROR; } // 循环调用每个模块的 create_srv_conf 与 create_loc_conf 回调,创建配置结构 for (i = 0; ngx_modules[i]; i++) { if (ngx_modules[i]->type != NGX_HTTP_MODULE) { continue; } module = ngx_modules[i]->ctx; if (module->create_srv_conf) { mconf = module->create_srv_conf(cf); if (mconf == NULL) { return NGX_CONF_ERROR; } ctx->srv_conf[ngx_modules[i]->ctx_index] = mconf; } if (module->create_loc_conf) { mconf = module->create_loc_conf(cf); if (mconf == NULL) { return NGX_CONF_ERROR; } ctx->loc_conf[ngx_modules[i]->ctx_index] = mconf; } } /* the server configuration context */ cscf = ctx->srv_conf[ngx_http_core_module.ctx_index]; cscf->ctx = ctx; cmcf = ctx->main_conf[ngx_http_core_module.ctx_index]; cscfp = ngx_array_push(&cmcf->servers); if (cscfp == NULL) { return NGX_CONF_ERROR; } *cscfp = cscf; /* parse inside server{} */ pcf = *cf; cf->ctx = ctx; cf->cmd_type = NGX_HTTP_SRV_CONF; // 解析 server 块配置 rv = ngx_conf_parse(cf, NULL); *cf = pcf; // 如果没有监听任何端口,则监听默认的 80 或 8000端口 if (rv == NGX_CONF_OK && !cscf->listen) { ngx_memzero(&lsopt, sizeof(ngx_http_listen_opt_t)); sin = &lsopt.u.sockaddr_in; sin->sin_family = AF_INET; #if (NGX_WIN32) sin->sin_port = htons(80); #else sin->sin_port = htons((getuid() == 0) ? 80 : 8000); #endif sin->sin_addr.s_addr = INADDR_ANY; lsopt.socklen = sizeof(struct sockaddr_in); lsopt.backlog = NGX_LISTEN_BACKLOG; lsopt.rcvbuf = -1; lsopt.sndbuf = -1; #if (NGX_HAVE_SETFIB) lsopt.setfib = -1; #endif #if (NGX_HAVE_TCP_FASTOPEN) lsopt.fastopen = -1; #endif lsopt.wildcard = 1; (void) ngx_sock_ntop(&lsopt.u.sockaddr, lsopt.socklen, lsopt.addr, NGX_SOCKADDR_STRLEN, 1); if (ngx_http_add_listen(cf, cscf, &lsopt) != NGX_OK) { return NGX_CONF_ERROR; } } return rv; } // }}}

 

这里有重新循环创建了 srv_conf 和 loc_conf,这是为什么呢?

这是为了防止在外层和内层出现相同的配置项,这些创建的配置结构会在最后 merge 到一起

 

// static char * // ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy) // location 块配置解析 {{{ static char * ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy) { char *rv; u_char *mod; size_t len; ngx_str_t *value, *name; ngx_uint_t i; ngx_conf_t save; ngx_http_module_t *module; ngx_http_conf_ctx_t *ctx, *pctx; ngx_http_core_loc_conf_t *clcf, *pclcf; ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_conf_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } pctx = cf->ctx; ctx->main_conf = pctx->main_conf; ctx->srv_conf = pctx->srv_conf; ctx->loc_conf = ngx_pcalloc(cf->pool, sizeof(void *) * ngx_http_max_module); if (ctx->loc_conf == NULL) { return NGX_CONF_ERROR; } for (i = 0; ngx_modules[i]; i++) { if (ngx_modules[i]->type != NGX_HTTP_MODULE) { continue; } module = ngx_modules[i]->ctx; if (module->create_loc_conf) { ctx->loc_conf[ngx_modules[i]->ctx_index] = module->create_loc_conf(cf); if (ctx->loc_conf[ngx_modules[i]->ctx_index] == NULL) { return NGX_CONF_ERROR; } } } clcf = ctx->loc_conf[ngx_http_core_module.ctx_index]; clcf->loc_conf = ctx->loc_conf; value = cf->args->elts; if (cf->args->nelts == 3) { len = value[1].len; mod = value[1].data; name = &value[2]; if (len == 1 && mod[0] == '=') { clcf->name = *name; clcf->exact_match = 1; } else if (len == 2 && mod[0] == '^' && mod[1] == '~') { clcf->name = *name; clcf->noregex = 1; } else if (len == 1 && mod[0] == '~') { if (ngx_http_core_regex_location(cf, clcf, name, 0) != NGX_OK) { return NGX_CONF_ERROR; } } else if (len == 2 && mod[0] == '~' && mod[1] == '*') { if (ngx_http_core_regex_location(cf, clcf, name, 1) != NGX_OK) { return NGX_CONF_ERROR; } } else { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid location modifier \"%V\"", &value[1]); return NGX_CONF_ERROR; } } else { name = &value[1]; if (name->data[0] == '=') { clcf->name.len = name->len - 1; clcf->name.data = name->data + 1; clcf->exact_match = 1; } else if (name->data[0] == '^' && name->data[1] == '~') { clcf->name.len = name->len - 2; clcf->name.data = name->data + 2; clcf->noregex = 1; } else if (name->data[0] == '~') { name->len--; name->data++; if (name->data[0] == '*') { name->len--; name->data++; if (ngx_http_core_regex_location(cf, clcf, name, 1) != NGX_OK) { return NGX_CONF_ERROR; } } else { if (ngx_http_core_regex_location(cf, clcf, name, 0) != NGX_OK) { return NGX_CONF_ERROR; } } } else { clcf->name = *name; if (name->data[0] == '@') { clcf->named = 1; } } } pclcf = pctx->loc_conf[ngx_http_core_module.ctx_index]; if (pclcf->name.len) { /* nested location */ #if 0 clcf->prev_location = pclcf; #endif if (pclcf->exact_match) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "location \"%V\" cannot be inside " "the exact location \"%V\"", &clcf->name, &pclcf->name); return NGX_CONF_ERROR; } if (pclcf->named) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "location \"%V\" cannot be inside " "the named location \"%V\"", &clcf->name, &pclcf->name); return NGX_CONF_ERROR; } if (clcf->named) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "named location \"%V\" can be " "on the server level only", &clcf->name); return NGX_CONF_ERROR; } len = pclcf->name.len; #if (NGX_PCRE) if (clcf->regex == NULL && ngx_filename_cmp(clcf->name.data, pclcf->name.data, len) != 0) #else if (ngx_filename_cmp(clcf->name.data, pclcf->name.data, len) != 0) #endif { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "location \"%V\" is outside location \"%V\"", &clcf->name, &pclcf->name); return NGX_CONF_ERROR; } } // 将 location 配置加入到 locations 配置链表中 if (ngx_http_add_location(cf, &pclcf->locations, clcf) != NGX_OK) { return NGX_CONF_ERROR; } save = *cf; cf->ctx = ctx; cf->cmd_type = NGX_HTTP_LOC_CONF; rv = ngx_conf_parse(cf, NULL); *cf = save; return rv; } // }}}

 

 

与 server 块解析函数 ngx_http_core_server 类似,他创建了所有模块的 loc_conf,为了防止内外层具有相同指令,在配置赋值完成后,会通过 merge 函数合并到一起

然而,与 server 块不同,location 块在 location 后面会通过路径或正则表达式指定 location 配置的应用 uri,因此,在 ngx_http_core_location 函数中调用 PCRE 进行了 location 命令的解析

解析完成后调用 ngx_http_add_location 将解析结果加入到 locations 链表中

 

// ngx_int_t ngx_http_add_location(ngx_conf_t *cf, ngx_queue_t **locations, // ngx_http_core_loc_conf_t *clcf) // 将 location 配置加入到 locations 配置链表中 {{{ ngx_int_t ngx_http_add_location(ngx_conf_t *cf, ngx_queue_t **locations, ngx_http_core_loc_conf_t *clcf) { ngx_http_location_queue_t *lq; if (*locations == NULL) { *locations = ngx_palloc(cf->temp_pool, sizeof(ngx_http_location_queue_t)); if (*locations == NULL) { return NGX_ERROR; } ngx_queue_init(*locations); } lq = ngx_palloc(cf->temp_pool, sizeof(ngx_http_location_queue_t)); if (lq == NULL) { return NGX_ERROR; } if (clcf->exact_match #if (NGX_PCRE) || clcf->regex #endif || clcf->named || clcf->noname) { lq->exact = clcf; lq->inclusive = NULL; } else { lq->exact = NULL; lq->inclusive = clcf; } lq->name = &clcf->name; lq->file_name = cf->conf_file->file.name.data; lq->line = cf->conf_file->line; ngx_queue_init(&lq->list); ngx_queue_insert_tail(*locations, &lq->queue); return NGX_OK; } // }}}

 

 

 

 






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