diff options
Diffstat (limited to 'src/http/modules/ngx_http_empty_gif_module.c')
-rw-r--r-- | src/http/modules/ngx_http_empty_gif_module.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/src/http/modules/ngx_http_empty_gif_module.c b/src/http/modules/ngx_http_empty_gif_module.c new file mode 100644 index 000000000..5c9a415c7 --- /dev/null +++ b/src/http/modules/ngx_http_empty_gif_module.c @@ -0,0 +1,173 @@ + +/* + * Copyright (C) Igor Sysoev + */ + +#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 */ +}; + + +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_int_t +ngx_http_empty_gif_handler(ngx_http_request_t *r) +{ + ngx_int_t rc; + ngx_buf_t *b; + ngx_chain_t out; + + if (r->method != NGX_HTTP_GET && r->method != NGX_HTTP_HEAD) { + return NGX_HTTP_NOT_ALLOWED; + } + + rc = ngx_http_discard_body(r); + + if (rc != NGX_OK && rc != NGX_AGAIN) { + return rc; + } + + r->headers_out.content_type.len = sizeof("image/gif") - 1; + r->headers_out.content_type.data = (u_char *) "image/gif"; + + if (r->method == NGX_HTTP_HEAD) { + r->headers_out.status = NGX_HTTP_OK; + + rc = ngx_http_send_header(r); + + if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { + return rc; + } + } + + b = ngx_create_temp_buf(r->pool, sizeof(ngx_empty_gif)); + if (b == NULL) { + return NGX_HTTP_INTERNAL_SERVER_ERROR; + } + + out.buf = b; + out.next = NULL; + + b->pos = ngx_empty_gif; + b->last = ngx_empty_gif + sizeof(ngx_empty_gif); + b->last_buf = 1; + + r->headers_out.status = NGX_HTTP_OK; + r->headers_out.content_length_n = b->last - b->pos; + r->headers_out.last_modified_time = 23349600; + + rc = ngx_http_send_header(r); + + if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) { + return rc; + } + + return ngx_http_output_filter(r, &out);; +} + + +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; +} |