Connection with another computer, winsock

[gelatine1]

 I have some ideas like creating a pong game (vs someone on a different pc) or some chat room but they require me to connect to another computer. I do have a second compankuter at home which I would like to use to test but I have no clue what address or hostname or port I should use. I've been reading on msdn about winsock and also iczelions tutorials (http://win32assembly.programminghorizon.com/asmsockguide.html) but they only explain the functions and their parameters.

I don't know very much about netwerking so could anyone explain me how to find out the ip address I should connect to or the hostname ? and what about the ports ?

Thanks in advance
jannes

[six_L]

read this first.
http://www.madwizard.org/programming/tutorials/netasm/

[anunitu]

Although I haven't looked at it,you might take a look at the Doom source code. It had a multi player function for death match. Not sure what form they used,but it might be interesting to check out.

[gelatine1]

Thanks, I'll read it :) and what is the doom source code ? where can I find it ?

[shaikkareem]

read this first.
http://www.madwizard.org/programming/tutorials/netasm/

:t

[anunitu]

Doom is a video game from the 80's I think,might be 90's,they released the source code a while back. Written in C or C++,it might show how to connect two systems.

Check the source here.
https://github.com/id-Software/DOOM

here is some info about interconnecting.
http://doom.wikia.com/wiki/Doom_networking_engine

[dedndave]

it may have been the old forum, but i remember someone posted a simple client-server pair

[gelatine1]

okay, I have read the madwizard.org tutorial now and I tried to write some code for a server. I tried to compile to test a little but somehow the compiler does not seem to recognize the SOCKADDR_IN structure ?
http://msdn.microsoft.com/en-us/library/aa917469.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms740496%28v=vs.85%29.aspx

Maybe I am just missing some include or something simple ? this is the top part of my code:

Code Select Expand


.386
.model flat,stdcall
option casemap:none

include \masm32\include\windows.inc
include \masm32\include\kernel32.inc
include \masm32\include\user32.inc
include \masm32\include\ws2_32.inc

includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\user32.lib
includelib \masm32\lib\ws2_32.lib

WinMain proto :DWORD,:DWORD,:DWORD,:DWORD

.const
WM_SOCKET equ WM_USER+8

.data
file db "D:\hi.txt",0
ClassName db "Window1",0
AppName db "Circle",0

listen_ip db "127.0.0.1",0
listen_port dd 27015

.data?
wsa WSADATA <>

sock dd ?
clientSock dd ?

sockAddr SOCKADDR_IN <>

.code
;and my code below is irrelevant.


Then the compiler gives as output this:

server.asm(33) : error A2008: syntax error : sockAddr

where 33 is the line number of the "sockAddr SOCKADDR_IN <>" line.

Is there anyone who can tell me why I am getting this error ?

Thanks in advance
Jannes

[jj2007]

Jannes,

In such cases, go to \Masm32\include and use a tool that does a case-insensitive search in all *.inc files. You would find out that the struct exists but... it is all lowercase 8)

sockaddr_in STRUCT
  sin_family    WORD      ?
  sin_port      WORD      ?
  sin_addr      in_addr <>
  sin_zero      BYTE 8 dup (?)
sockaddr_in ENDS

[dedndave]

there are \masm32\include\winsock.inc (or wsock32.inc) and \masm32\lib\wsock32.lib files

but, if i remember correctly, they are superceded by

Code Select Expand

        include     \masm32\include\ws2_32.inc
        includelib  \masm32\lib\ws2_32.lib

[gelatine1]

Oh wow thank you very much jj2007  :redface:

[gelatine1]

Okay, now I have created my server and client. The client is trying to connect to the loop-back ip address (127.0.0.1) and it succeeds. I then call the send function (to send a random dword) and the send function returns 4 so it means it worked as it should.

However on the server side who listens for incoming connections I am not receiving anything. Not even an FD_ACCEPT message so I was wondering what is going wrong ? Maybe it is wrong to try to connect with 127.0.0.1 ? Ill try to give some relevant parts of my code below:

Client:

Code Select Expand


.data
ClassName db "Window1",0
AppName db "Client",0

listen_ip db "127.0.0.1",0
listen_port dd 27015


.data?
wc WNDCLASSEX <>

wsa WSADATA <>

sock dd ?
clientSock dd ?

sockAddr sockaddr_in <>
connected dd ? ; a bool to check if the connection is established, initialised to false

.code
start:
    ;first of all a window is created, but I skipped the code here because it's not relevant (except the messageloop)

WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
LOCAL buffer[4]:byte

mov eax,uMsg

__cont3:
cmp eax, WM_SOCKET
jnz __cont2

mov eax,lParam
cmp ax,FD_CONNECT
jnz _sockerror

mov connected,1

lea esi,buffer
invoke send,sock,esi,4,0

_sockerror:
jmp __cont

__cont2:
cmp eax, WM_DESTROY
jnz __cont1

cmp wParam,1
jz _quit

invoke WSACleanup

_quit:
invoke PostQuitMessage,NULL
jmp __cont
__cont1:
cmp eax,WM_CREATE
jnz __cont0

mov buffer,63

invoke WSAStartup,202h,addr wsa
cmp eax,0
jnz _error

invoke socket,AF_INET,SOCK_STREAM,IPPROTO_TCP
cmp eax,INVALID_SOCKET
jz _error2

mov sock,eax

invoke WSAAsyncSelect,sock,hWnd,WM_SOCKET,FD_READ+FD_WRITE+FD_CONNECT+FD_CLOSE

mov     [sockAddr.sin_family], AF_INET
    invoke  htons,listen_port
    mov     [sockAddr.sin_port], ax
invoke inet_addr,addr listen_ip
    mov     [sockAddr.sin_addr.S_un.S_addr], eax

invoke connect,sock,addr sockAddr,sizeof sockAddr

jmp __cont

_error2:
invoke WSACleanup
_error:
invoke PostMessage,hWnd,WM_DESTROY,1,0
jmp __cont

__cont0:
invoke DefWindowProc,hWnd,uMsg,wParam,lParam     ; Default message processing
ret

__cont:
xor eax,eax
ret
WndProc endp
end start


and the server:

Code Select Expand


WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
LOCAL buffer[4]:byte

mov eax,uMsg

__cont3:
cmp eax, WM_SOCKET
jnz __cont2

mov eax,lParam
cmp ax,FD_ACCEPT
jnz _read

invoke accept,sock,0,0
cmp eax,INVALID_SOCKET
jz _sockerror

mov clientSock,eax
jmp __cont

_read:
cmp ax,FD_READ
jnz _sockerror

lea esi,buffer
invoke recv,clientSock,esi,4,0

mov eax,dword ptr [esi]
cmp eax,63
jnz __cont

invoke MessageBox,hWnd,addr file,addr file,MB_OK

_sockerror:
jmp __cont

__cont2:
cmp eax, WM_DESTROY
jnz __cont1

cmp wParam,1
jz _quit

invoke WSACleanup

_quit:
invoke PostQuitMessage,NULL
jmp __cont

__cont1:
cmp eax,WM_CREATE
jnz __cont0

invoke WSAStartup,202h,addr wsa
cmp eax,0
jnz _error

invoke socket,AF_INET,SOCK_STREAM,IPPROTO_TCP
cmp eax,INVALID_SOCKET
jz _error2

mov sock,eax

invoke WSAAsyncSelect,sock,hWnd,WM_SOCKET,FD_READ+FD_WRITE+FD_CONNECT+FD_CLOSE+FD_ACCEPT

mov     [sockAddr.sin_family], AF_INET
    invoke  htons,listen_port
    mov     [sockAddr.sin_port], ax
    mov     [sockAddr.sin_addr.S_un.S_addr], INADDR_ANY ;use default

invoke bind,sock,addr sockAddr,sizeof sockAddr
cmp eax,SOCKET_ERROR
jz _error2

invoke listen,sock,SOMAXCONN
cmp eax,SOCKET_ERROR
jz _error2

jmp __cont

_error2:
invoke WSACleanup
_error:
invoke PostMessage,hWnd,WM_DESTROY,1,0
jmp __cont

__cont0:
invoke DefWindowProc,hWnd,uMsg,wParam,lParam     ; Default message processing
ret

__cont:
xor eax,eax
ret
WndProc endp
end start


Any help is welcome, thanks in advance!
Jannes

[Tedd]

Zip and attach full working code to allow for proper testing and debugging.

[gelatine1]

change file extension back to rar if you can't unzip. (I had to change it to zip)

[dedndave]

you might find these helpful

http://www.masmforum.com/board/index.php?topic=8292.0

https://gist.github.com/jamesladd/720718