Mercurial > hg > nginx
view src/http/modules/ngx_http_try_files_module.c @ 7507:ea05113adbdb
Range filter: fixed loss of incoming chain links.
Filters are not allowed to change incoming chain links, and should allocate
their own links if any modifications are needed. Nevertheless
ngx_http_range_singlepart_body() modified incoming chain links in some
cases, notably at the end of the requested range.
No problems caused by this are currently known, mostly because of
limited number of possible modifications and the position of the range
body filter in the filter chain. Though this behaviour is clearly incorrect
and tests demonstrate that it can at least cause some proxy buffers being
lost when using proxy_force_ranges, leading to less effective handling
of responses.
Fix is to always allocate new chain links in ngx_http_range_singlepart_body().
Links are explicitly freed to ensure constant memory usage with long-lived
requests.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 13 May 2019 22:44:02 +0300 |
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; }