mirror of
https://github.com/nginx/nginx.git
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173 lines
6.1 KiB
C
173 lines
6.1 KiB
C
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/*
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* Copyright (C) Igor Sysoev
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*/
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#include <ngx_config.h>
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#include <ngx_core.h>
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#include <ngx_http.h>
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static char *ngx_http_empty_gif(ngx_conf_t *cf, ngx_command_t *cmd,
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void *conf);
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static ngx_command_t ngx_http_empty_gif_commands[] = {
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{ ngx_string("empty_gif"),
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NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS,
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ngx_http_empty_gif,
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0,
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0,
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NULL },
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ngx_null_command
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};
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/* the minimal single pixel transparent GIF, 43 bytes */
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static u_char ngx_empty_gif[] = {
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'G', 'I', 'F', '8', '9', 'a', /* header */
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/* logical screen descriptor */
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0x01, 0x00, /* logical screen width */
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0x01, 0x00, /* logical screen height */
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0x80, /* global 1-bit color table */
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0x01, /* background color #1 */
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0x00, /* no aspect ratio */
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/* global color table */
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0x00, 0x00, 0x00, /* #0: black */
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0xff, 0xff, 0xff, /* #1: white */
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/* graphic control extension */
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0x21, /* extension introducer */
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0xf9, /* graphic control label */
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0x04, /* block size */
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0x01, /* transparent color is given, */
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/* no disposal specified, */
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/* user input is not expected */
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0x00, 0x00, /* delay time */
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0x01, /* transparent color #1 */
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0x00, /* block terminator */
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/* image descriptor */
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0x2c, /* image separator */
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0x00, 0x00, /* image left position */
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0x00, 0x00, /* image top position */
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0x01, 0x00, /* image width */
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0x01, 0x00, /* image height */
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0x00, /* no local color table, no interlaced */
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/* table based image data */
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0x02, /* LZW minimum code size, */
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/* must be at least 2-bit */
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0x02, /* block size */
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0x4c, 0x01, /* compressed bytes 01_001_100, 0000000_1 */
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/* 100: clear code */
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/* 001: 1 */
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/* 101: end of information code */
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0x00, /* block terminator */
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0x3B /* trailer */
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};
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static ngx_http_module_t ngx_http_empty_gif_module_ctx = {
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NULL, /* preconfiguration */
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NULL, /* postconfiguration */
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NULL, /* create main configuration */
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NULL, /* init main configuration */
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NULL, /* create server configuration */
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NULL, /* merge server configuration */
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NULL, /* create location configuration */
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NULL /* merge location configuration */
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};
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ngx_module_t ngx_http_empty_gif_module = {
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NGX_MODULE_V1,
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&ngx_http_empty_gif_module_ctx, /* module context */
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ngx_http_empty_gif_commands, /* module directives */
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NGX_HTTP_MODULE, /* module type */
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NULL, /* init master */
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NULL, /* init module */
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NULL, /* init process */
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NULL, /* init thread */
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NULL, /* exit thread */
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NULL, /* exit process */
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NULL, /* exit master */
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NGX_MODULE_V1_PADDING
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};
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static ngx_int_t
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ngx_http_empty_gif_handler(ngx_http_request_t *r)
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{
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ngx_int_t rc;
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ngx_buf_t *b;
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ngx_chain_t out;
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if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) {
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return NGX_HTTP_NOT_ALLOWED;
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}
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rc = ngx_http_discard_request_body(r);
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if (rc != NGX_OK) {
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return rc;
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}
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r->headers_out.content_type.len = sizeof("image/gif") - 1;
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r->headers_out.content_type.data = (u_char *) "image/gif";
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if (r->method == NGX_HTTP_HEAD) {
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r->headers_out.status = NGX_HTTP_OK;
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r->headers_out.content_length_n = sizeof(ngx_empty_gif);
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r->headers_out.last_modified_time = 23349600;
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return ngx_http_send_header(r);
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}
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b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t));
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if (b == NULL) {
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return NGX_HTTP_INTERNAL_SERVER_ERROR;
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}
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out.buf = b;
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out.next = NULL;
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b->pos = ngx_empty_gif;
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b->last = ngx_empty_gif + sizeof(ngx_empty_gif);
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b->memory = 1;
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b->last_buf = 1;
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r->headers_out.status = NGX_HTTP_OK;
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r->headers_out.content_length_n = sizeof(ngx_empty_gif);
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r->headers_out.last_modified_time = 23349600;
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rc = ngx_http_send_header(r);
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if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
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return rc;
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}
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return ngx_http_output_filter(r, &out);
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}
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static char *
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ngx_http_empty_gif(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
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{
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ngx_http_core_loc_conf_t *clcf;
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clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
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clcf->handler = ngx_http_empty_gif_handler;
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return NGX_CONF_OK;
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}
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