Mercurial > hg > nginx-quic
annotate src/http/modules/ngx_http_empty_gif_module.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
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date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | d620f497c50f |
children |
rev | line source |
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577 | 1 |
2 /* | |
3 * Copyright (C) Igor Sysoev | |
4412 | 4 * Copyright (C) Nginx, Inc. |
577 | 5 */ |
6 | |
7 #include <ngx_config.h> | |
8 #include <ngx_core.h> | |
9 #include <ngx_http.h> | |
10 | |
11 | |
12 static char *ngx_http_empty_gif(ngx_conf_t *cf, ngx_command_t *cmd, | |
13 void *conf); | |
14 | |
15 static ngx_command_t ngx_http_empty_gif_commands[] = { | |
16 | |
17 { ngx_string("empty_gif"), | |
18 NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS, | |
19 ngx_http_empty_gif, | |
20 0, | |
21 0, | |
22 NULL }, | |
23 | |
24 ngx_null_command | |
25 }; | |
26 | |
27 | |
28 /* the minimal single pixel transparent GIF, 43 bytes */ | |
29 | |
30 static u_char ngx_empty_gif[] = { | |
31 | |
581 | 32 'G', 'I', 'F', '8', '9', 'a', /* header */ |
577 | 33 |
581 | 34 /* logical screen descriptor */ |
35 0x01, 0x00, /* logical screen width */ | |
36 0x01, 0x00, /* logical screen height */ | |
37 0x80, /* global 1-bit color table */ | |
38 0x01, /* background color #1 */ | |
39 0x00, /* no aspect ratio */ | |
577 | 40 |
581 | 41 /* global color table */ |
42 0x00, 0x00, 0x00, /* #0: black */ | |
43 0xff, 0xff, 0xff, /* #1: white */ | |
577 | 44 |
581 | 45 /* graphic control extension */ |
46 0x21, /* extension introducer */ | |
47 0xf9, /* graphic control label */ | |
48 0x04, /* block size */ | |
49 0x01, /* transparent color is given, */ | |
50 /* no disposal specified, */ | |
51 /* user input is not expected */ | |
52 0x00, 0x00, /* delay time */ | |
53 0x01, /* transparent color #1 */ | |
54 0x00, /* block terminator */ | |
577 | 55 |
581 | 56 /* image descriptor */ |
57 0x2c, /* image separator */ | |
58 0x00, 0x00, /* image left position */ | |
59 0x00, 0x00, /* image top position */ | |
60 0x01, 0x00, /* image width */ | |
61 0x01, 0x00, /* image height */ | |
62 0x00, /* no local color table, no interlaced */ | |
577 | 63 |
581 | 64 /* table based image data */ |
65 0x02, /* LZW minimum code size, */ | |
66 /* must be at least 2-bit */ | |
67 0x02, /* block size */ | |
577 | 68 0x4c, 0x01, /* compressed bytes 01_001_100, 0000000_1 */ |
581 | 69 /* 100: clear code */ |
70 /* 001: 1 */ | |
71 /* 101: end of information code */ | |
72 0x00, /* block terminator */ | |
577 | 73 |
581 | 74 0x3B /* trailer */ |
577 | 75 }; |
76 | |
77 | |
667 | 78 static ngx_http_module_t ngx_http_empty_gif_module_ctx = { |
577 | 79 NULL, /* preconfiguration */ |
80 NULL, /* postconfiguration */ | |
81 | |
82 NULL, /* create main configuration */ | |
83 NULL, /* init main configuration */ | |
84 | |
85 NULL, /* create server configuration */ | |
86 NULL, /* merge server configuration */ | |
87 | |
88 NULL, /* create location configuration */ | |
89 NULL /* merge location configuration */ | |
90 }; | |
91 | |
92 | |
93 ngx_module_t ngx_http_empty_gif_module = { | |
94 NGX_MODULE_V1, | |
95 &ngx_http_empty_gif_module_ctx, /* module context */ | |
96 ngx_http_empty_gif_commands, /* module directives */ | |
97 NGX_HTTP_MODULE, /* module type */ | |
98 NULL, /* init master */ | |
99 NULL, /* init module */ | |
100 NULL, /* init process */ | |
101 NULL, /* init thread */ | |
102 NULL, /* exit thread */ | |
103 NULL, /* exit process */ | |
104 NULL, /* exit master */ | |
105 NGX_MODULE_V1_PADDING | |
106 }; | |
107 | |
108 | |
3635
c0113b6648de
use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
diff
changeset
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109 static ngx_str_t ngx_http_gif_type = ngx_string("image/gif"); |
c0113b6648de
use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
diff
changeset
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110 |
c0113b6648de
use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
diff
changeset
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111 |
577 | 112 static ngx_int_t |
113 ngx_http_empty_gif_handler(ngx_http_request_t *r) | |
114 { | |
3635
c0113b6648de
use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
diff
changeset
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115 ngx_http_complex_value_t cv; |
577 | 116 |
645 | 117 if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) { |
577 | 118 return NGX_HTTP_NOT_ALLOWED; |
119 } | |
120 | |
3635
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use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
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121 ngx_memzero(&cv, sizeof(ngx_http_complex_value_t)); |
577 | 122 |
3635
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use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
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changeset
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123 cv.value.len = sizeof(ngx_empty_gif); |
c0113b6648de
use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
diff
changeset
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124 cv.value.data = ngx_empty_gif; |
577 | 125 r->headers_out.last_modified_time = 23349600; |
126 | |
3635
c0113b6648de
use ngx_http_send_response() in empty_gif
Igor Sysoev <igor@sysoev.ru>
parents:
3516
diff
changeset
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127 return ngx_http_send_response(r, NGX_HTTP_OK, &ngx_http_gif_type, &cv); |
577 | 128 } |
129 | |
130 | |
131 static char * | |
132 ngx_http_empty_gif(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) | |
133 { | |
134 ngx_http_core_loc_conf_t *clcf; | |
135 | |
136 clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module); | |
137 clcf->handler = ngx_http_empty_gif_handler; | |
138 | |
139 return NGX_CONF_OK; | |
140 } |