Fix Can not resolve "localhost" if not Network adapter exists #4988 #5019
Conversation
| return result; | ||
| } | ||
| #if defined(_WIN32) | ||
| else if(rc == WSANO_DATA && address.isLoopback()) // no data record found and is local host |
There was a problem hiding this comment.
Does it make sense putting this condition first, before checking the "localhost" hostname?
There was a problem hiding this comment.
i would say checking the rc value is much cheaper than checking for localhost or loopback and is less common.
There was a problem hiding this comment.
I apologise for not being clear enough.
In line 86 (above) it is first checked if the hostname is localhost and if that is not true then in line 145 is is checked if the device is a loopback.
From the logic point of view, what shall be the order? localhost first of loopback first? Or it does not matter?
There was a problem hiding this comment.
@matejk Those are different methods:
First is 'DNS::hostByName()' line 63-114, second is 'DNS::hostByAddress' from line 117-176
| #if defined(POCO_OS_FAMILY_WINDOWS) | ||
| else if(rc == WSANO_DATA && hostname == "localhost") // no data record found and is local host | ||
| { | ||
| #if defined(POCO_HAVE_IPv6) |
There was a problem hiding this comment.
I don't think it's a good idea to default to IPv6 solely based on it being present on the system where poco was compiled. Not even the presence of IPv6 on the runtime system would warrant it being default, given the prevalence of IPv4.
Bottom line, I would prefer this to be decided at runtime, based on an additional function argument, defaulting to IPv4.
There was a problem hiding this comment.
@aleks-f Since this is an edge case i am not sure if a addition argument wouldn't confuse users.
Does an function exists, that determines if ipv6 is available?
Otherwise i would use 127.0.0.1
|
I don't think Poco should do any name resolution at all outside of that provided by the operating system's network stack. |
|
@obiltschnig i can not respond to you comment. |
4 participants
Fill HostEntry with localhost and a default loopback address if 'getaddrinfo' returns 'WSANO_DATA'