view src/http/modules/ngx_http_empty_gif_module.c @ 7730:1a719ee45526

Upstream: proxy_ssl_conf_command and friends. Similarly to ssl_conf_command, proxy_ssl_conf_command (grpc_ssl_conf_command, uwsgi_ssl_conf_command) can be used to set arbitrary OpenSSL configuration parameters as long as nginx is compiled with OpenSSL 1.0.2 or later, when connecting to upstream servers with SSL. Full list of available configuration commands can be found in the SSL_CONF_cmd manual page (https://www.openssl.org/docs/man1.1.1/man3/SSL_CONF_cmd.html).
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 22 Oct 2020 18:00:23 +0300
parents d620f497c50f
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */

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


static char *ngx_http_empty_gif(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);

static ngx_command_t  ngx_http_empty_gif_commands[] = {

    { ngx_string("empty_gif"),
      NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS,
      ngx_http_empty_gif,
      0,
      0,
      NULL },

      ngx_null_command
};


/* the minimal single pixel transparent GIF, 43 bytes */

static u_char  ngx_empty_gif[] = {

    'G', 'I', 'F', '8', '9', 'a',  /* header                                 */

                                   /* logical screen descriptor              */
    0x01, 0x00,                    /* logical screen width                   */
    0x01, 0x00,                    /* logical screen height                  */
    0x80,                          /* global 1-bit color table               */
    0x01,                          /* background color #1                    */
    0x00,                          /* no aspect ratio                        */

                                   /* global color table                     */
    0x00, 0x00, 0x00,              /* #0: black                              */
    0xff, 0xff, 0xff,              /* #1: white                              */

                                   /* graphic control extension              */
    0x21,                          /* extension introducer                   */
    0xf9,                          /* graphic control label                  */
    0x04,                          /* block size                             */
    0x01,                          /* transparent color is given,            */
                                   /*     no disposal specified,             */
                                   /*     user input is not expected         */
    0x00, 0x00,                    /* delay time                             */
    0x01,                          /* transparent color #1                   */
    0x00,                          /* block terminator                       */

                                   /* image descriptor                       */
    0x2c,                          /* image separator                        */
    0x00, 0x00,                    /* image left position                    */
    0x00, 0x00,                    /* image top position                     */
    0x01, 0x00,                    /* image width                            */
    0x01, 0x00,                    /* image height                           */
    0x00,                          /* no local color table, no interlaced    */

                                   /* table based image data                 */
    0x02,                          /* LZW minimum code size,                 */
                                   /*     must be at least 2-bit             */
    0x02,                          /* block size                             */
    0x4c, 0x01,                    /* compressed bytes 01_001_100, 0000000_1 */
                                   /* 100: clear code                        */
                                   /* 001: 1                                 */
                                   /* 101: end of information code           */
    0x00,                          /* block terminator                       */

    0x3B                           /* trailer                                */
};


static ngx_http_module_t  ngx_http_empty_gif_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_empty_gif_module = {
    NGX_MODULE_V1,
    &ngx_http_empty_gif_module_ctx, /* module context */
    ngx_http_empty_gif_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_str_t  ngx_http_gif_type = ngx_string("image/gif");


static ngx_int_t
ngx_http_empty_gif_handler(ngx_http_request_t *r)
{
    ngx_http_complex_value_t  cv;

    if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) {
        return NGX_HTTP_NOT_ALLOWED;
    }

    ngx_memzero(&cv, sizeof(ngx_http_complex_value_t));

    cv.value.len = sizeof(ngx_empty_gif);
    cv.value.data = ngx_empty_gif;
    r->headers_out.last_modified_time = 23349600;

    return ngx_http_send_response(r, NGX_HTTP_OK, &ngx_http_gif_type, &cv);
}


static char *
ngx_http_empty_gif(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_http_core_loc_conf_t  *clcf;

    clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
    clcf->handler = ngx_http_empty_gif_handler;

    return NGX_CONF_OK;
}