view src/http/modules/ngx_http_random_index_module.c @ 7355:b64adc956643

Rewrite: removed r->err_status special handling (ticket #1634). Trying to look into r->err_status in the "return" directive makes it behave differently than real errors generated in other parts of the code, and is an endless source of various problems. This behaviour was introduced in 726:7b71936d5299 (0.4.4) with the comment "fix: "return" always overrode "error_page" response code". It is not clear if there were any real cases this was expected to fix, but there are several cases which are broken due to this change, some previously fixed (4147:7f64de1cc2c0). In ticket #1634, the problem is that when r->err_status is set to a non-special status code, it is not possible to return a response by simply returning r->err_status. If this is the case, the only option is to return script's e->status instead. An example configuration: location / { error_page 404 =200 /err502; return 404; } location = /err502 { return 502; } After the change, such a configuration will properly return standard 502 error, much like it happens when a 502 error is generated by proxy_pass. This also fixes the following configuration to properly close connection as clearly requested by "return 444": location / { error_page 404 /close; return 404; } location = /close { return 444; } Previously, this required "error_page 404 = /close;" to work as intended.
author Maxim Dounin <mdounin@mdounin.ru>
date Fri, 21 Sep 2018 15:59:33 +0300
parents 47daf95d0138
children 061ec464813f
line wrap: on
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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_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;
}