[code].text:190166A0 ; ecx = a pointer to a sockaddr structure
.text:190166A0
.text:190166A0 ; BOOL __stdcall GetSockNameEx()
.text:190166A0 GetSockNameEx proc near ; CODE XREF: sub_19013E80+A2p
.text:190166A0 ; sub_19016810+EDp
.text:190166A0
.text:190166A0 namelen = dword ptr -1
.text:190166A0
.text:190166A0 000 push ecx
.text:190166A1 004 push esi
.text:190166A2 008 xor eax, eax ; Clear eax
.text:190166A4 008 mov esi, ecx ; Backup ecx
.text:190166A6 008 mov [ecx], eax ; Set the entire structure to NULL
.text:190166A8 008 mov [ecx+4], eax
.text:190166AB 008 mov [ecx+8], eax
.text:190166AE 008 mov [ecx+0Ch], eax
.text:190166B1 008 mov eax, TCPSocket ; Move the TCPSocket into eax
.text:190166B6 008 cmp eax, INVALID_SOCKET ; Make sure it's a valid socket
.text:190166B9 008 jnz short loc_190166C0 ; Load the address of this local variable into edx
.text:190166BB 008 xor eax, eax
.text:190166BD 008 pop esi
.text:190166BE 004 pop ecx
.text:190166BF 000 retn ; If the socket is invalid, return 0
.text:190166C0 ; ---------------------------------------------------------------------------
.text:190166C0
.text:190166C0 loc_190166C0: ; CODE XREF: GetSockNameEx+19j
.text:190166C0 008 lea edx, [esp+5+namelen] ; Load the address of this local variable into edx
.text:190166C4 008 mov [esp+5+namelen], 10h ; Set it to 0x10
.text:190166CC 008 push edx ; namelen
.text:190166CD 00C push esi ; name
.text:190166CE 010 push eax ; s
.text:190166CF 014 call ds:getsockname ; retrieves the local name for a socket
.text:190166CF ; s [in] Descriptor identifying a socket.
.text:190166CF ; name [out] Receives the address (name) of the socket.
.text:190166CF ; namelen [in, out] Size of the name buffer.
.text:190166CF ;
.text:190166D5 008 cmp eax, INVALID_SOCKET
.text:190166D8 008 jnz short loc_190166DF
.text:190166DA 008 xor eax, eax
.text:190166DC 008 pop esi
.text:190166DD 004 pop ecx
.text:190166DE 000 retn
.text:190166DF ; ---------------------------------------------------------------------------
.text:190166DF
.text:190166DF loc_190166DF: ; CODE XREF: GetSockNameEx+38j
.text:190166DF 008 xor eax, eax ; Clear eax
.text:190166E1 008 add esi, 8
.text:190166E4 008 mov [esi], eax
.text:190166E6 008 mov [esi+4], eax
.text:190166E9 008 mov eax, 1 ; return TRUE
.text:190166EE 008 pop esi
.text:190166EF 004 pop ecx
.text:190166F0
.text:190166F0 unknown_libname_47:
.text:190166F0 000 retn
.text:190166F0 GetSockNameEx endp

[/code]

This is a snippet of code from battle.snp 1.10. Besides my inability to name variables, I'm trying to figure out what it does. I know it should be a __fastcall function, but that's not important...

Anyway, I can't figure out what's going on after 190166DF. It seems to add 8 to the pointer, which would put it to sockaddr.sa_name + 6 bytes, then it sets that and the next dword to NULL, but I have no idea why it's doing that.. can anybody shed some light on it?

If what you say is true, it seems to be setting sin_zero to zero...

[code]
struct sockaddr_in {
short sin_family;
u_short sin_port;
struct in_addr sin_addr;
char sin_zero[8];
};
[/code]

Hmm, that would make sense. I was looking at these definitions:
[code]int getsockname(
SOCKET s,
struct sockaddr FAR *name,
int FAR *namelen
);[/code]
and
[code]
struct sockaddr {
u_short sa_family;
char sa_data[14];
};
[/code]
(From VS.net's SDK documentation)

You can see why it confused me based on these definitions. Thanks! :)

[quote author=iago link=board=7;threadid=1568;start=0#msg11804 date=1054983739]
Hmm, that would make sense. I was looking at these definitions:
[code]int getsockname(
SOCKET s,
struct sockaddr FAR *name,
int FAR *namelen
);[/code]
and
[code]
struct sockaddr {
u_short sa_family;
char sa_data[14];
};
[/code]
(From VS.net's SDK documentation)

You can see why it confused me based on these definitions. Thanks! :)
[/quote]For future reference: The SOCKADDR struct's contents beyond sa_family are socket-family specific. When you're dealing with AF_INET, you use SOCKADDR_IN; there's a variety of other versions, however.

Yes, I figured that out. Well, Adron actually told me this morning. Thanks for the help, though! :-)