Mercurial > hg > nginx
view contrib/geo2nginx.pl @ 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> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | c9ad0d9c7d59 |
children |
line wrap: on
line source
#!/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"; }