nginx-0.1.29-RELEASE import *) Feature: the ngx_http_ssi_module supports "include virtual" command. *) Feature: the ngx_http_ssi_module supports the condition command like 'if expr="$NAME"' and "else" and "endif" commands. Only one nested level is supported. *) Feature: the ngx_http_ssi_module supports the DATE_LOCAL and DATE_GMT variables and "config timefmt" command. *) Feature: the "ssi_ignore_recycled_buffers" directive. *) Bugfix: the "echo" command did not show the default value for the empty QUERY_STRING variable. *) Change: the ngx_http_proxy_module was rewritten. *) Feature: the "proxy_redirect", "proxy_pass_request_headers", "proxy_pass_request_body", and "proxy_method" directives. *) Feature: the "proxy_set_header" directive. The "proxy_x_var" was canceled and must be replaced with the proxy_set_header directive. *) Change: the "proxy_preserve_host" is canceled and must be replaced with the "proxy_set_header Host $host" and the "proxy_redirect off" directives, the "proxy_set_header Host $host:$proxy_port" directive and the appropriate proxy_redirect directives. *) Change: the "proxy_set_x_real_ip" is canceled and must be replaced with the "proxy_set_header X-Real-IP $remote_addr" directive. *) Change: the "proxy_add_x_forwarded_for" is canceled and must be replaced with the "proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for" directive. *) Change: the "proxy_set_x_url" is canceled and must be replaced with the "proxy_set_header X-URL http://$host:$server_port$request_uri" directive. *) Feature: the "fastcgi_param" directive. *) Change: the "fastcgi_root", "fastcgi_set_var" and "fastcgi_params" directive are canceled and must be replaced with the fastcgi_param directives. *) Feature: the "index" directive can use the variables. *) Feature: the "index" directive can be used at http and server levels. *) Change: the last index only in the "index" directive can be absolute. *) Feature: the "rewrite" directive can use the variables. *) Feature: the "internal" directive. *) Feature: the CONTENT_LENGTH, CONTENT_TYPE, REMOTE_PORT, SERVER_ADDR, SERVER_PORT, SERVER_PROTOCOL, DOCUMENT_ROOT, SERVER_NAME, REQUEST_METHOD, REQUEST_URI, and REMOTE_USER variables. *) Change: nginx now passes the invalid lines in a client request headers or a backend response header. *) Bugfix: if the backend did not transfer response for a long time and the "send_timeout" was less than "proxy_read_timeout", then nginx returned the 408 response. *) Bugfix: the segmentation fault was occurred if the backend sent an invalid line in response header; the bug had appeared in 0.1.26. *) Bugfix: the segmentation fault may occurred in FastCGI fault tolerance configuration. *) Bugfix: the "expires" directive did not remove the previous "Expires" and "Cache-Control" headers. *) Bugfix: nginx did not take into account trailing dot in "Host" header line. *) Bugfix: the ngx_http_auth_module did not work under Linux. *) Bugfix: the rewrite directive worked incorrectly, if the arguments were in a request. *) Bugfix: nginx could not be built on MacOS X.

/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>



static ngx_int_t ngx_http_not_modified_filter_init(ngx_cycle_t *cycle);


static ngx_http_module_t  ngx_http_not_modified_filter_module_ctx = {
    NULL,                                  /* preconfiguration */
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    NULL,                                  /* create server configuration */
    NULL,                                  /* merge server configuration */

    NULL,                                  /* create location configuration */
    NULL                                   /* merge location configuration */
};


ngx_module_t  ngx_http_not_modified_filter_module = {
    NGX_MODULE_V1,
    &ngx_http_not_modified_filter_module_ctx, /* module context */
    NULL,                                  /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    ngx_http_not_modified_filter_init,     /* init module */
    NULL                                   /* init process */
};


static ngx_http_output_header_filter_pt  ngx_http_next_header_filter;


static ngx_int_t ngx_http_not_modified_header_filter(ngx_http_request_t *r)
{
    time_t  ims;

    if (r->headers_out.status != NGX_HTTP_OK
        || r->main
        || r->headers_in.if_modified_since == NULL
        || r->headers_out.last_modified_time == -1)
    {
        return ngx_http_next_header_filter(r);
    }

    ims = ngx_http_parse_time(r->headers_in.if_modified_since->value.data,
                              r->headers_in.if_modified_since->value.len);
    
    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http ims:%d lm:%d", ims, r->headers_out.last_modified_time);

    /*
     * I think that the equality of the dates is correcter
     */

    if (ims != NGX_ERROR && ims == r->headers_out.last_modified_time) {
        r->headers_out.status = NGX_HTTP_NOT_MODIFIED;
        r->headers_out.content_type.len = 0;
        r->headers_out.content_length_n = -1;
        r->headers_out.content_length = NULL;
#if 0
        r->headers_out.accept_ranges->hash = 0;
#endif
    }

    return ngx_http_next_header_filter(r);
}


static ngx_int_t ngx_http_not_modified_filter_init(ngx_cycle_t *cycle)
{
    ngx_http_next_header_filter = ngx_http_top_header_filter;
    ngx_http_top_header_filter = ngx_http_not_modified_header_filter;

    return NGX_OK;
}