Mercurial > hg > nginx
view contrib/geo2nginx.pl @ 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> |
---|---|
date | Thu, 07 Jul 2016 21:03:21 +0300 |
parents | c9ad0d9c7d59 |
children |
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#!/usr/bin/perl -w # (c) Andrei Nigmatulin, 2005 # # this script provided "as is", without any warranties. use it at your own risk. # # special thanx to Andrew Sitnikov for perl port # # this script converts CSV geoip database (free download at http://www.maxmind.com/app/geoip_country) # to format, suitable for use with nginx_http_geo module (http://sysoev.ru/nginx) # # for example, line with ip range # # "62.16.68.0","62.16.127.255","1041253376","1041268735","RU","Russian Federation" # # will be converted to four subnetworks: # # 62.16.68.0/22 RU; # 62.16.72.0/21 RU; # 62.16.80.0/20 RU; # 62.16.96.0/19 RU; use warnings; use strict; while( <STDIN> ){ if (/"[^"]+","[^"]+","([^"]+)","([^"]+)","([^"]+)"/){ print_subnets($1, $2, $3); } } sub print_subnets { my ($a1, $a2, $c) = @_; my $l; while ($a1 <= $a2) { for ($l = 0; ($a1 & (1 << $l)) == 0 && ($a1 + ((1 << ($l + 1)) - 1)) <= $a2; $l++){}; print long2ip($a1) . "/" . (32 - $l) . " " . $c . ";\n"; $a1 += (1 << $l); } } sub long2ip { my $ip = shift; my $str = 0; $str = ($ip & 255); $ip >>= 8; $str = ($ip & 255).".$str"; $ip >>= 8; $str = ($ip & 255).".$str"; $ip >>= 8; $str = ($ip & 255).".$str"; }