ngx_http_random_index_module

auto/modules

@@ -81,6 +81,7 @@ fi
 #     ngx_http_dav_module
 #     ngx_http_autoindex_module
 #     ngx_http_index_module
+#     ngx_http_random_index_module
 #
 #     ngx_http_access_module
 #     ngx_http_realip_module
@@ -177,6 +178,12 @@ fi
 
 HTTP_MODULES="$HTTP_MODULES $HTTP_INDEX_MODULE"
 
+if [ $HTTP_RANDOM_INDEX = YES ]; then
+    have=NGX_HTTP_RANDOM_INDEX . auto/have
+    HTTP_MODULES="$HTTP_MODULES $HTTP_RANDOM_INDEX_MODULE"
+    HTTP_SRCS="$HTTP_SRCS $HTTP_RANDOM_INDEX_SRCS"
+fi
+
 if [ $HTTP_AUTH_BASIC = YES ]; then
     have=NGX_HTTP_AUTH_BASIC . auto/have
     have=NGX_CRYPT . auto/have

auto/options

@@ -64,6 +64,7 @@ HTTP_ACCESS=YES
 HTTP_AUTH_BASIC=YES
 HTTP_USERID=YES
 HTTP_AUTOINDEX=YES
+HTTP_RANDOM_INDEX=NO
 HTTP_STATUS=NO
 HTTP_GEO=YES
 HTTP_MAP=YES
@@ -171,6 +172,7 @@ do
         --with-http_dav_module)          HTTP_DAV=YES               ;;
         --with-http_flv_module)          HTTP_FLV=YES               ;;
         --with-http_gzip_static_module)  HTTP_GZIP_STATIC=YES       ;;
+        --with-http_random_index_module) HTTP_RANDOM_INDEX=YES      ;;
 
         --without-http_charset_module)   HTTP_CHARSET=NO            ;;
         --without-http_gzip_module)      HTTP_GZIP=NO               ;;
@@ -287,6 +289,7 @@ cat << END
   --with-http_dav_module             enable ngx_http_dav_module
   --with-http_flv_module             enable ngx_http_flv_module
   --with-http_gzip_static_module     enable ngx_http_gzip_static_module
+  --with-http_random_index_module    enable ngx_http_random_index_module
   --with-http_stub_status_module     enable ngx_http_stub_status_module
 
   --without-http_charset_module      disable ngx_http_charset_module

auto/sources

@@ -366,6 +366,10 @@ HTTP_AUTOINDEX_MODULE=ngx_http_autoindex_module
 HTTP_AUTOINDEX_SRCS=src/http/modules/ngx_http_autoindex_module.c
 
 
+HTTP_RANDOM_INDEX_MODULE=ngx_http_random_index_module
+HTTP_RANDOM_INDEX_SRCS=src/http/modules/ngx_http_random_index_module.c
+
+
 HTTP_STATUS_MODULE=ngx_http_status_module
 HTTP_STATUS_SRCS=src/http/modules/ngx_http_status_module.c
 

src/http/modules/ngx_http_random_index_module.c

@@ -0,0 +1,321 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+typedef struct {
+    ngx_flag_t  enable;
+} ngx_http_random_index_loc_conf_t;
+
+
+#define NGX_HTTP_RANDOM_INDEX_PREALLOCATE  50
+
+
+static ngx_int_t ngx_http_random_index_error(ngx_http_request_t *r,
+    ngx_dir_t *dir, ngx_str_t *name);
+static ngx_int_t ngx_http_random_index_init(ngx_conf_t *cf);
+static void *ngx_http_random_index_create_loc_conf(ngx_conf_t *cf);
+static char *ngx_http_random_index_merge_loc_conf(ngx_conf_t *cf,
+    void *parent, void *child);
+
+
+static ngx_command_t  ngx_http_random_index_commands[] = {
+
+    { ngx_string("random_index"),
+      NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_random_index_loc_conf_t, enable),
+      NULL },
+
+      ngx_null_command
+};
+
+
+static ngx_http_module_t  ngx_http_random_index_module_ctx = {
+    NULL,                                  /* preconfiguration */
+    ngx_http_random_index_init,            /* postconfiguration */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    NULL,                                  /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    ngx_http_random_index_create_loc_conf, /* create location configration */
+    ngx_http_random_index_merge_loc_conf   /* merge location configration */
+};
+
+
+ngx_module_t  ngx_http_random_index_module = {
+    NGX_MODULE_V1,
+    &ngx_http_random_index_module_ctx,     /* module context */
+    ngx_http_random_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
+};
+
+
+static ngx_int_t
+ngx_http_random_index_handler(ngx_http_request_t *r)
+{
+    u_char                            *last, *filename;
+    size_t                             len, allocated, root;
+    ngx_err_t                          err;
+    ngx_int_t                          rc;
+    ngx_str_t                          path, uri, *name;
+    ngx_dir_t                          dir;
+    ngx_uint_t                         n, level;
+    ngx_array_t                        names;
+    ngx_http_random_index_loc_conf_t  *rlcf;
+
+    if (r->uri.data[r->uri.len - 1] != '/') {
+        return NGX_DECLINED;
+    }
+
+    /* TODO: Win32 */
+    if (r->zero_in_uri) {
+        return NGX_DECLINED;
+    }
+
+    if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD|NGX_HTTP_POST))) {
+        return NGX_DECLINED;
+    }
+
+    rlcf = ngx_http_get_module_loc_conf(r, ngx_http_random_index_module);
+
+    if (!rlcf->enable) {
+        return NGX_DECLINED;
+    }
+
+#if (NGX_HAVE_D_TYPE)
+    len = NGX_DIR_MASK_LEN;
+#else
+    len = NGX_HTTP_RANDOM_INDEX_PREALLOCATE;
+#endif
+
+    last = ngx_http_map_uri_to_path(r, &path, &root, len);
+    if (last == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    allocated = path.len;
+
+    path.len = last - path.data - 1;
+    path.data[path.len] = '\0';
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "http random index: \"%s\"", path.data);
+
+    if (ngx_open_dir(&path, &dir) == NGX_ERROR) {
+        err = ngx_errno;
+
+        if (err == NGX_ENOENT
+            || err == NGX_ENOTDIR
+            || err == NGX_ENAMETOOLONG)
+        {
+            level = NGX_LOG_ERR;
+            rc = NGX_HTTP_NOT_FOUND;
+
+        } else if (err == NGX_EACCES) {
+            level = NGX_LOG_ERR;
+            rc = NGX_HTTP_FORBIDDEN;
+
+        } else {
+            level = NGX_LOG_CRIT;
+            rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        ngx_log_error(level, r->connection->log, err,
+                      ngx_open_dir_n " \"%s\" failed", path.data);
+
+        return rc;
+    }
+
+    if (ngx_array_init(&names, r->pool, 32, sizeof(ngx_str_t)) != NGX_OK) {
+        return ngx_http_random_index_error(r, &dir, &path);
+    }
+
+    filename = path.data;
+    filename[path.len] = '/';
+
+    for ( ;; ) {
+        ngx_set_errno(0);
+
+        if (ngx_read_dir(&dir) == NGX_ERROR) {
+            err = ngx_errno;
+
+            if (err != NGX_ENOMOREFILES) {
+                ngx_log_error(NGX_LOG_CRIT, r->connection->log, err,
+                              ngx_read_dir_n " \"%V\" failed", &path);
+                return ngx_http_random_index_error(r, &dir, &path);
+            }
+
+            break;
+        }
+
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                       "http random index file: \"%s\"", ngx_de_name(&dir));
+
+        if (ngx_de_name(&dir)[0] == '.') {
+            continue;
+        }
+
+        len = ngx_de_namelen(&dir);
+
+        if (!dir.valid_type) {
+
+            /* 1 byte for '/' and 1 byte for terminating '\0' */
+
+            if (path.len + 1 + len + 1 > allocated) {
+                allocated = path.len + 1 + len + 1
+                                     + NGX_HTTP_RANDOM_INDEX_PREALLOCATE;
+
+                filename = ngx_pnalloc(r->pool, allocated);
+                if (filename == NULL) {
+                    return ngx_http_random_index_error(r, &dir, &path);
+                }
+
+                last = ngx_cpystrn(filename, path.data, path.len + 1);
+                *last++ = '/';
+            }
+
+            ngx_cpystrn(last, ngx_de_name(&dir), len + 1);
+
+            if (ngx_de_info(filename, &dir) == NGX_FILE_ERROR) {
+                err = ngx_errno;
+
+                if (err != NGX_ENOENT) {
+                    ngx_log_error(NGX_LOG_CRIT, r->connection->log, err,
+                                  ngx_de_info_n " \"%s\" failed", filename);
+                    return ngx_http_random_index_error(r, &dir, &path);
+                }
+
+                if (ngx_de_link_info(filename, &dir) == NGX_FILE_ERROR) {
+                    ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno,
+                                  ngx_de_link_info_n " \"%s\" failed",
+                                  filename);
+                    return ngx_http_random_index_error(r, &dir, &path);
+                }
+            }
+        }
+
+        if (!ngx_de_is_file(&dir)) {
+            continue;
+        }
+
+        name = ngx_array_push(&names);
+        if (name == NULL) {
+            return ngx_http_random_index_error(r, &dir, &path);
+        }
+
+        name->len = len;
+
+        name->data = ngx_pnalloc(r->pool, len);
+        if (name->data == NULL) {
+            return ngx_http_random_index_error(r, &dir, &path);
+        }
+
+        ngx_memcpy(name->data, ngx_de_name(&dir), len);
+    }
+
+    if (ngx_close_dir(&dir) == NGX_ERROR) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, ngx_errno,
+                      ngx_close_dir_n " \"%s\" failed", &path);
+    }
+
+    n = names.nelts;
+
+    if (n == 0) {
+        return NGX_DECLINED;
+    }
+
+    name = names.elts;
+
+    n = (ngx_uint_t) (((uint64_t) ngx_random() * n) / 0x80000000);
+
+    uri.len = r->uri.len + name[n].len;
+
+    uri.data = ngx_pnalloc(r->pool, uri.len);
+    if (uri.data == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    last = ngx_copy(uri.data, r->uri.data, r->uri.len);
+    ngx_memcpy(last, name[n].data, name[n].len);
+
+    return ngx_http_internal_redirect(r, &uri, &r->args);
+}
+
+
+static ngx_int_t
+ngx_http_random_index_error(ngx_http_request_t *r, ngx_dir_t *dir,
+    ngx_str_t *name)
+{
+    if (ngx_close_dir(dir) == NGX_ERROR) {
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, ngx_errno,
+                      ngx_close_dir_n " \"%V\" failed", name);
+    }
+
+    return NGX_HTTP_INTERNAL_SERVER_ERROR;
+}
+
+
+static void *
+ngx_http_random_index_create_loc_conf(ngx_conf_t *cf)
+{
+    ngx_http_random_index_loc_conf_t  *conf;
+
+    conf = ngx_palloc(cf->pool, sizeof(ngx_http_random_index_loc_conf_t));
+    if (conf == NULL) {
+        return NGX_CONF_ERROR;
+    }
+
+    conf->enable = NGX_CONF_UNSET;
+
+    return conf;
+}
+
+
+static char *
+ngx_http_random_index_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
+{
+    ngx_http_random_index_loc_conf_t *prev = parent;
+    ngx_http_random_index_loc_conf_t *conf = child;
+
+    ngx_conf_merge_value(conf->enable, prev->enable, 0);
+
+    return NGX_CONF_OK;
+}
+
+
+static ngx_int_t
+ngx_http_random_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_random_index_handler;
+
+    return NGX_OK;
+}