[asterisk-dev] [Code Review] SIP URI comparison test (plus some bug fixes)

[Kevin P. Fleming]

On 07/22/2010 08:58 AM, Olle E. Johansson wrote:
> 
> 21 jul 2010 kl. 16.56 skrev Rod Dorman:
> 
>> On Wednesday, July 21, 2010, 04:18:43, Kevin P. Fleming wrote:
>>> On 07/21/2010 10:00 AM, Olle E. Johansson wrote:
>>>> 20 jul 2010 kl. 15.15 skrev Simon Perreault:
>>>>> /trunk/channels/sip/reqresp_parser.c
>>>>> <https://reviewboard.asterisk.org/r/792/#comment5354>
>>>>>
>>>>>   There's a subtle but important bug here: glibc's strcasecmp() is locale-dependent. SIP URI domains are limited to the ASCII character set. So we want ASCII-based case-insensitive comparison, not something that depends on the current locale.
>>>>>
>>>>>   This could be solved by using strcasecmp_l() and passing the "C" locale (I think). Or just roll your own ASCII-based strcasecmp().
>>>>
>>>> That is a huge issue and possibly affects many different parts of asterisk.
>>>>
>>>> While writing the bug report I forgot to mention that the string comparision of IP also affects IPv4.
>>>>
>>>> 192.02.68.01 == 192.02.68.1
>>>> 192.2.068.1 != 192.2.68.1
>>>>
>>>> The zero prefix indicates that the group is written in octal notation...
>>
>>> Are you sure about that? The ABNF that Mark already posted shows that
>>> each group is limited to three digits, and three digits is not adequate
>>> to allow for the range 0-255 to be expressed on octal, only in decimal.
>>
>> Not only that, in RFC 3986 "Uniform Resource Identifier (URI): Generic
>> Syntax" under section "7.4 Rare IP Address Formats" it explicitly states
>>    These additional IP address formats are not allowed in the URI
>>    syntax due to differences between platform implementations.
>>
> 
> Right. That's the theory. Then you have what happens out there in the wild... 
> 
> The new draft points out in very detail that you should compare the ip address in binary. Period.

I don't think that was the point he was making; his point was that the
conversion from text format to binary format should *always* interpret
the digit strings as decimal, regardless of whether any digit group
starts with a zero digit or not.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
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