Mercurial > hg > nginx
view src/http/modules/ngx_http_try_files_module.c @ 9300:5be23505292b default tip
SSI: fixed incorrect or duplicate stub output.
Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set
if there are data in the first buffer sent in the subrequest. As a
result, following the change mentioned this flag cannot be used to
prevent duplicate ngx_http_ssi_stub_output() calls, since it is not
set if there was already some output, but the first buffer was empty.
Still, when there are multiple subrequests, even an empty subrequest
response might be delayed by the postpone filter, leading to a second
call of ngx_http_ssi_stub_output() during finalization from
ngx_http_writer() the subreqest buffers are released by the postpone
filter. Since r->request_output is not set after the first call, this
resulted in duplicate stub output.
Additionally, checking only the first buffer might be wrong in some
unusual cases. For example, the first buffer might be empty if
$r->flush() is called before printing any data in the embedded Perl
module.
Depending on the postpone_output value and corresponding sizes, this
issue can result in either duplicate or unexpected stub output, or
"zero size buf in writer" alerts.
Following 8124:f5515e727656 (1.23.4), it became slightly easier to
reproduce the issue, as empty static files and empty cache items now
result in a response with an empty buffer. Before the change, an empty
proxied response can be used to reproduce the issue.
Fix is check all buffers and set r->request_output if any non-empty
buffers are sent. This ensures that all unusual cases of non-empty
responses are covered, and also that r->request_output will be set
after the first stub output, preventing duplicate output.
Reported by Jan Gassen.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 04 Jul 2024 17:41:28 +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; }