Mercurial > hg > nginx
view src/http/modules/ngx_http_index_module.c @ 9300:5be23505292b
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 | e55e28e6998f |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_str_t name; ngx_array_t *lengths; ngx_array_t *values; } ngx_http_index_t; typedef struct { ngx_array_t *indices; /* array of ngx_http_index_t */ size_t max_index_len; } ngx_http_index_loc_conf_t; #define NGX_HTTP_DEFAULT_INDEX "index.html" static ngx_int_t ngx_http_index_test_dir(ngx_http_request_t *r, ngx_http_core_loc_conf_t *clcf, u_char *path, u_char *last); static ngx_int_t ngx_http_index_error(ngx_http_request_t *r, ngx_http_core_loc_conf_t *clcf, u_char *file, ngx_err_t err); static ngx_int_t ngx_http_index_init(ngx_conf_t *cf); static void *ngx_http_index_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static char *ngx_http_index_set_index(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_index_commands[] = { { ngx_string("index"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE, ngx_http_index_set_index, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_index_module_ctx = { NULL, /* preconfiguration */ ngx_http_index_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_index_create_loc_conf, /* create location configuration */ ngx_http_index_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_index_module = { NGX_MODULE_V1, &ngx_http_index_module_ctx, /* module context */ ngx_http_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 }; /* * Try to open/test the first index file before the test of directory * existence because valid requests should prevail over invalid ones. * If open()/stat() of a file will fail then stat() of a directory * should be faster because kernel may have already cached some data. * Besides, Win32 may return ERROR_PATH_NOT_FOUND (NGX_ENOTDIR) at once. * Unix has ENOTDIR error; however, it's less helpful than Win32's one: * it only indicates that path points to a regular file, not a directory. */ static ngx_int_t ngx_http_index_handler(ngx_http_request_t *r) { u_char *p, *name; size_t len, root, reserve, allocated; ngx_int_t rc; ngx_str_t path, uri; ngx_uint_t i, dir_tested; ngx_http_index_t *index; 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_index_loc_conf_t *ilcf; ngx_http_script_len_code_pt lcode; 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; } ilcf = ngx_http_get_module_loc_conf(r, ngx_http_index_module); clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); allocated = 0; root = 0; dir_tested = 0; name = NULL; /* suppress MSVC warning */ path.data = NULL; index = ilcf->indices->elts; for (i = 0; i < ilcf->indices->nelts; i++) { if (index[i].lengths == NULL) { if (index[i].name.data[0] == '/') { return ngx_http_internal_redirect(r, &index[i].name, &r->args); } reserve = ilcf->max_index_len; len = index[i].name.len; } else { ngx_memzero(&e, sizeof(ngx_http_script_engine_t)); e.ip = index[i].lengths->elts; e.request = r; e.flushed = 1; /* 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); } /* 16 bytes are preallocation */ reserve = len + 16; } if (reserve > allocated) { name = ngx_http_map_uri_to_path(r, &path, &root, reserve); if (name == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } allocated = path.data + path.len - name; } if (index[i].values == NULL) { /* index[i].name.len includes the terminating '\0' */ ngx_memcpy(name, index[i].name.data, index[i].name.len); path.len = (name + index[i].name.len - 1) - path.data; } else { e.ip = index[i].values->elts; e.pos = name; while (*(uintptr_t *) e.ip) { code = *(ngx_http_script_code_pt *) e.ip; code((ngx_http_script_engine_t *) &e); } if (*name == '/') { uri.len = len - 1; uri.data = name; return ngx_http_internal_redirect(r, &uri, &r->args); } path.len = e.pos - path.data; *e.pos = '\0'; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "open index \"%V\"", &path); 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; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, of.err, "%s \"%s\" failed", of.failed, path.data); #if (NGX_HAVE_OPENAT) if (of.err == NGX_EMLINK || of.err == NGX_ELOOP) { return NGX_HTTP_FORBIDDEN; } #endif if (of.err == NGX_ENOTDIR || of.err == NGX_ENAMETOOLONG || of.err == NGX_EACCES) { return ngx_http_index_error(r, clcf, path.data, of.err); } if (!dir_tested) { rc = ngx_http_index_test_dir(r, clcf, path.data, name - 1); if (rc != NGX_OK) { return rc; } dir_tested = 1; } if (of.err == NGX_ENOENT) { continue; } ngx_log_error(NGX_LOG_CRIT, r->connection->log, of.err, "%s \"%s\" failed", of.failed, path.data); return NGX_HTTP_INTERNAL_SERVER_ERROR; } uri.len = r->uri.len + len - 1; if (!clcf->alias) { uri.data = path.data + root; } else { uri.data = ngx_pnalloc(r->pool, uri.len); if (uri.data == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } p = ngx_copy(uri.data, r->uri.data, r->uri.len); ngx_memcpy(p, name, len - 1); } return ngx_http_internal_redirect(r, &uri, &r->args); } return NGX_DECLINED; } static ngx_int_t ngx_http_index_test_dir(ngx_http_request_t *r, ngx_http_core_loc_conf_t *clcf, u_char *path, u_char *last) { u_char c; ngx_str_t dir; ngx_open_file_info_t of; c = *last; if (c != '/' || path == last) { /* "alias" without trailing slash */ c = *(++last); } *last = '\0'; dir.len = last - path; dir.data = path; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http index check dir: \"%V\"", &dir); ngx_memzero(&of, sizeof(ngx_open_file_info_t)); of.test_dir = 1; of.test_only = 1; of.valid = clcf->open_file_cache_valid; of.errors = clcf->open_file_cache_errors; if (ngx_http_set_disable_symlinks(r, clcf, &dir, &of) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_open_cached_file(clcf->open_file_cache, &dir, &of, r->pool) != NGX_OK) { if (of.err) { #if (NGX_HAVE_OPENAT) if (of.err == NGX_EMLINK || of.err == NGX_ELOOP) { return NGX_HTTP_FORBIDDEN; } #endif if (of.err == NGX_ENOENT) { *last = c; return ngx_http_index_error(r, clcf, dir.data, NGX_ENOENT); } if (of.err == NGX_EACCES) { *last = c; /* * ngx_http_index_test_dir() is called after the first index * file testing has returned an error distinct from NGX_EACCES. * This means that directory searching is allowed. */ return NGX_OK; } ngx_log_error(NGX_LOG_CRIT, r->connection->log, of.err, "%s \"%s\" failed", of.failed, dir.data); } return NGX_HTTP_INTERNAL_SERVER_ERROR; } *last = c; if (of.is_dir) { return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "\"%s\" is not a directory", dir.data); return NGX_HTTP_INTERNAL_SERVER_ERROR; } static ngx_int_t ngx_http_index_error(ngx_http_request_t *r, ngx_http_core_loc_conf_t *clcf, u_char *file, ngx_err_t err) { if (err == NGX_EACCES) { ngx_log_error(NGX_LOG_ERR, r->connection->log, err, "\"%s\" is forbidden", file); return NGX_HTTP_FORBIDDEN; } if (clcf->log_not_found) { ngx_log_error(NGX_LOG_ERR, r->connection->log, err, "\"%s\" is not found", file); } return NGX_HTTP_NOT_FOUND; } static void * ngx_http_index_create_loc_conf(ngx_conf_t *cf) { ngx_http_index_loc_conf_t *conf; conf = ngx_palloc(cf->pool, sizeof(ngx_http_index_loc_conf_t)); if (conf == NULL) { return NULL; } conf->indices = NULL; conf->max_index_len = 0; return conf; } static char * ngx_http_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_index_loc_conf_t *prev = parent; ngx_http_index_loc_conf_t *conf = child; ngx_http_index_t *index; if (conf->indices == NULL) { conf->indices = prev->indices; conf->max_index_len = prev->max_index_len; } if (conf->indices == NULL) { conf->indices = ngx_array_create(cf->pool, 1, sizeof(ngx_http_index_t)); if (conf->indices == NULL) { return NGX_CONF_ERROR; } index = ngx_array_push(conf->indices); if (index == NULL) { return NGX_CONF_ERROR; } index->name.len = sizeof(NGX_HTTP_DEFAULT_INDEX); index->name.data = (u_char *) NGX_HTTP_DEFAULT_INDEX; index->lengths = NULL; index->values = NULL; conf->max_index_len = sizeof(NGX_HTTP_DEFAULT_INDEX); return NGX_CONF_OK; } return NGX_CONF_OK; } static ngx_int_t ngx_http_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_index_handler; return NGX_OK; } /* TODO: warn about duplicate indices */ static char * ngx_http_index_set_index(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_index_loc_conf_t *ilcf = conf; ngx_str_t *value; ngx_uint_t i, n; ngx_http_index_t *index; ngx_http_script_compile_t sc; if (ilcf->indices == NULL) { ilcf->indices = ngx_array_create(cf->pool, 2, sizeof(ngx_http_index_t)); if (ilcf->indices == NULL) { return NGX_CONF_ERROR; } } value = cf->args->elts; for (i = 1; i < cf->args->nelts; i++) { if (value[i].data[0] == '/' && i != cf->args->nelts - 1) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "only the last index in \"index\" directive " "should be absolute"); } if (value[i].len == 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "index \"%V\" in \"index\" directive is invalid", &value[1]); return NGX_CONF_ERROR; } index = ngx_array_push(ilcf->indices); if (index == NULL) { return NGX_CONF_ERROR; } index->name.len = value[i].len; index->name.data = value[i].data; index->lengths = NULL; index->values = NULL; n = ngx_http_script_variables_count(&value[i]); if (n == 0) { if (ilcf->max_index_len < index->name.len) { ilcf->max_index_len = index->name.len; } if (index->name.data[0] == '/') { continue; } /* include the terminating '\0' to the length to use ngx_memcpy() */ index->name.len++; continue; } ngx_memzero(&sc, sizeof(ngx_http_script_compile_t)); sc.cf = cf; sc.source = &value[i]; sc.lengths = &index->lengths; sc.values = &index->values; sc.variables = n; sc.complete_lengths = 1; sc.complete_values = 1; if (ngx_http_script_compile(&sc) != NGX_OK) { return NGX_CONF_ERROR; } } return NGX_CONF_OK; }