blob: b47ee4f0dde3ee46705570d4f17485587fcb8b19 [file] [log] [blame]
/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#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 configuration */
ngx_http_random_index_merge_loc_conf /* merge location configuration */
};
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;
}
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.type == 0 || ngx_de_is_link(&dir)) {
/* 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 " \"%V\" 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 NULL;
}
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;
}