Mercurial > hg > nginx
view src/http/modules/ngx_http_try_files_module.c @ 8045:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | cce6936ed2f4 |
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_array_t *lengths; ngx_array_t *values; ngx_str_t name; unsigned code:10; unsigned test_dir:1; } ngx_http_try_file_t; typedef struct { ngx_http_try_file_t *try_files; } ngx_http_try_files_loc_conf_t; static ngx_int_t ngx_http_try_files_handler(ngx_http_request_t *r); static char *ngx_http_try_files(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_http_try_files_create_loc_conf(ngx_conf_t *cf); static ngx_int_t ngx_http_try_files_init(ngx_conf_t *cf); static ngx_command_t ngx_http_try_files_commands[] = { { ngx_string("try_files"), NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_2MORE, ngx_http_try_files, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_try_files_module_ctx = { NULL, /* preconfiguration */ ngx_http_try_files_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_try_files_create_loc_conf, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_try_files_module = { NGX_MODULE_V1, &ngx_http_try_files_module_ctx, /* module context */ ngx_http_try_files_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_try_files_handler(ngx_http_request_t *r) { size_t len, root, alias, reserve, allocated; u_char *p, *name; ngx_str_t path, args; ngx_uint_t test_dir; ngx_http_try_file_t *tf; ngx_open_file_info_t of; ngx_http_script_code_pt code; ngx_http_script_engine_t e; ngx_http_core_loc_conf_t *clcf; ngx_http_script_len_code_pt lcode; ngx_http_try_files_loc_conf_t *tlcf; tlcf = ngx_http_get_module_loc_conf(r, ngx_http_try_files_module); if (tlcf->try_files == NULL) { return NGX_DECLINED; } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "try files handler"); allocated = 0; root = 0; name = NULL; /* suppress MSVC warning */ path.data = NULL; tf = tlcf->try_files; clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); alias = clcf->alias; for ( ;; ) { if (tf->lengths) { ngx_memzero(&e, sizeof(ngx_http_script_engine_t)); e.ip = tf->lengths->elts; e.request = r; /* 1 is for terminating '\0' as in static names */ len = 1; while (*(uintptr_t *) e.ip) { lcode = *(ngx_http_script_len_code_pt *) e.ip; len += lcode(&e); } } else { len = tf->name.len; } if (!alias) { reserve = len > r->uri.len ? len - r->uri.len : 0; } else if (alias == NGX_MAX_SIZE_T_VALUE) { reserve = len; } else { reserve = len > r->uri.len - alias ? len - (r->uri.len - alias) : 0; } if (reserve > allocated || !allocated) { /* 16 bytes are preallocation */ allocated = reserve + 16; if (ngx_http_map_uri_to_path(r, &path, &root, allocated) == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } name = path.data + root; } if (tf->values == NULL) { /* tf->name.len includes the terminating '\0' */ ngx_memcpy(name, tf->name.data, tf->name.len); path.len = (name + tf->name.len - 1) - path.data; } else { e.ip = tf->values->elts; e.pos = name; e.flushed = 1; while (*(uintptr_t *) e.ip) { code = *(ngx_http_script_code_pt *) e.ip; code((ngx_http_script_engine_t *) &e); } path.len = e.pos - path.data; *e.pos = '\0'; if (alias && alias != NGX_MAX_SIZE_T_VALUE && ngx_strncmp(name, r->uri.data, alias) == 0) { ngx_memmove(name, name + alias, len - alias); path.len -= alias; } } test_dir = tf->test_dir; tf++; ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "trying to use %s: \"%s\" \"%s\"", test_dir ? "dir" : "file", name, path.data); if (tf->lengths == NULL && tf->name.len == 0) { if (tf->code) { return tf->code; } path.len -= root; path.data += root; if (path.data[0] == '@') { (void) ngx_http_named_location(r, &path); } else { ngx_http_split_args(r, &path, &args); (void) ngx_http_internal_redirect(r, &path, &args); } ngx_http_finalize_request(r, NGX_DONE); return NGX_DONE; } ngx_memzero(&of, sizeof(ngx_open_file_info_t)); of.read_ahead = clcf->read_ahead; of.directio = clcf->directio; of.valid = clcf->open_file_cache_valid; of.min_uses = clcf->open_file_cache_min_uses; of.test_only = 1; of.errors = clcf->open_file_cache_errors; of.events = clcf->open_file_cache_events; if (ngx_http_set_disable_symlinks(r, clcf, &path, &of) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_open_cached_file(clcf->open_file_cache, &path, &of, r->pool) != NGX_OK) { if (of.err == 0) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (of.err != NGX_ENOENT && of.err != NGX_ENOTDIR && of.err != NGX_ENAMETOOLONG) { ngx_log_error(NGX_LOG_CRIT, r->connection->log, of.err, "%s \"%s\" failed", of.failed, path.data); } continue; } if (of.is_dir != test_dir) { continue; } path.len -= root; path.data += root; if (!alias) { r->uri = path; } else if (alias == NGX_MAX_SIZE_T_VALUE) { if (!test_dir) { r->uri = path; r->add_uri_to_alias = 1; } } else { name = r->uri.data; r->uri.len = alias + path.len; r->uri.data = ngx_pnalloc(r->pool, r->uri.len); if (r->uri.data == NULL) { r->uri.len = 0; return NGX_HTTP_INTERNAL_SERVER_ERROR; } p = ngx_copy(r->uri.data, name, alias); ngx_memcpy(p, path.data, path.len); } ngx_http_set_exten(r); ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "try file uri: \"%V\"", &r->uri); return NGX_DECLINED; } /* not reached */ } static char * ngx_http_try_files(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_try_files_loc_conf_t *tlcf = conf; ngx_str_t *value; ngx_int_t code; ngx_uint_t i, n; ngx_http_try_file_t *tf; ngx_http_script_compile_t sc; if (tlcf->try_files) { return "is duplicate"; } tf = ngx_pcalloc(cf->pool, cf->args->nelts * sizeof(ngx_http_try_file_t)); if (tf == NULL) { return NGX_CONF_ERROR; } tlcf->try_files = tf; value = cf->args->elts; for (i = 0; i < cf->args->nelts - 1; i++) { tf[i].name = value[i + 1]; if (tf[i].name.len > 0 && tf[i].name.data[tf[i].name.len - 1] == '/' && i + 2 < cf->args->nelts) { tf[i].test_dir = 1; tf[i].name.len--; tf[i].name.data[tf[i].name.len] = '\0'; } n = ngx_http_script_variables_count(&tf[i].name); if (n) { ngx_memzero(&sc, sizeof(ngx_http_script_compile_t)); sc.cf = cf; sc.source = &tf[i].name; sc.lengths = &tf[i].lengths; sc.values = &tf[i].values; sc.variables = n; sc.complete_lengths = 1; sc.complete_values = 1; if (ngx_http_script_compile(&sc) != NGX_OK) { return NGX_CONF_ERROR; } } else { /* add trailing '\0' to length */ tf[i].name.len++; } } if (tf[i - 1].name.data[0] == '=') { code = ngx_atoi(tf[i - 1].name.data + 1, tf[i - 1].name.len - 2); if (code == NGX_ERROR || code > 999) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid code \"%*s\"", tf[i - 1].name.len - 1, tf[i - 1].name.data); return NGX_CONF_ERROR; } tf[i].code = code; } return NGX_CONF_OK; } static void * ngx_http_try_files_create_loc_conf(ngx_conf_t *cf) { ngx_http_try_files_loc_conf_t *tlcf; tlcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_try_files_loc_conf_t)); if (tlcf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * tlcf->try_files = NULL; */ return tlcf; } static ngx_int_t ngx_http_try_files_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_PRECONTENT_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_try_files_handler; return NGX_OK; }