Mercurial > hg > nginx-quic
annotate docs/html/50x.html @ 6627:ad736705a744
HTTP/2: avoid left-shifting signed integer into the sign bit.
On non-aligned platforms, properly cast argument before left-shifting it in
ngx_http_v2_parse_uint32 that is used with u_char. Otherwise it propagates
to int to hold the value and can step over the sign bit. Usually, on known
compilers, this results in negation. Furthermore, a subsequent store into a
wider type, that is ngx_uint_t on 64-bit platforms, results in sign-extension.
In practice, this can be observed in debug log as a very large exclusive bit
value, when client sent PRIORITY frame with exclusive bit set:
: *14 http2 PRIORITY frame sid:5 on 1 excl:8589934591 weight:17
Found with UndefinedBehaviorSanitizer.
author | Sergey Kandaurov <pluknet@nginx.com> |
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date | Thu, 07 Jul 2016 21:03:21 +0300 |
parents | b5ba6f22a0fc |
children | 1cd63ae46243 |
rev | line source |
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4840
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
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1 <!DOCTYPE html> |
657 | 2 <html> |
3 <head> | |
4840
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Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
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4 <title>Error</title> |
657 | 5 <style> |
4840
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
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6 body { |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
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7 width: 35em; |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
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8 margin: 0 auto; |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
9 font-family: Tahoma, Verdana, Arial, sans-serif; |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
10 } |
657 | 11 </style> |
12 </head> | |
4840
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
13 <body> |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
14 <h1>An error occurred.</h1> |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
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15 <p>Sorry, the page you are looking for is currently unavailable.<br/> |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
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16 Please try again later.</p> |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
17 <p>If you are the system administrator of this resource then you should check |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
18 the <a href="http://nginx.org/r/error_log">error log</a> for details.</p> |
b5ba6f22a0fc
Improved 50x error page.
Valentin Bartenev <vbart@nginx.com>
parents:
663
diff
changeset
|
19 <p><em>Faithfully yours, nginx.</em></p> |
657 | 20 </body> |
21 </html> |