Mingw sockets on w7

[tristen]

hello!

i'm cross-compiling a program that uses berkeley-style sockets.

all compiles well, but the data structures for sockaddr and sockaddr_in all seem to be a bit screwy when i run the same code on windows 7. this results in the wrong ip addresses being translated from getaddrinfo and friends, particularly in translating a host name into a binary address and ultimately to a text ip address.

so...it took me a bit searching to work out that the data structures on xp and windows 7 differ. i couldn't find anything specific unfortunately, just the fact that they do.

has anyone else had the same problemo and how did they solve it?

cheers
tristen

[David Becker]

Originally Posted by tristen

hello!

i'm cross-compiling a program that uses berkeley-style sockets.

all compiles well, but the data structures for sockaddr and sockaddr_in all seem to be a bit screwy when i run the same code on windows 7. this results in the wrong ip addresses being translated from getaddrinfo and friends, particularly in translating a host name into a binary address and ultimately to a text ip address.

so...it took me a bit searching to work out that the data structures on xp and windows 7 differ. i couldn't find anything specific unfortunately, just the fact that they do.

It sounded like a case of host/net order mismatch. Maybe this helps: http://msdn.microsoft.com/en-us/libr...=VS.85%29.aspx

David

[tristen]

cheers david, that link made me think "it has to be a bug in my code" and lo, it turned out to be a bug in my code.

some gory details that may help someone else:

i had a pointer to a sockaddr_in structure in an addrinfo list returned by getaddrinfo. I subsequently freed the addrinfo structure (using freeaddrinfo). I continued to use the pointer to the sockaddr_in despite the fact that i'd freed the addrinfo structure. This is of course undefined behaviour.

xp __seemed__ to be ok about it the several dozen times i'd tested, but w7 100% of the time wasn't. I dunno and don't care how vista feels about it