Re: connect() question (solaris vs obsd (vs linux))

[Rob Pickering <rob@syntonet.co.uk>]

Tor Houghton Said:
> 
>     sa.sin_port=53;
>     if(bind(sd,(struct sockaddr *)&sa,sizeof(sa)) == -1) {
>       perror("Unable to bind()");
>       if(sd != -1) {close(sd);}
>       return;
>     }
> -- end excerpt --
> 
> Basically, the change is that I use bind() to change the source address. I
> know I should perhaps use raw sockets, or libnet, but I didn't want to
> change the code too much.
> 
> The odd thing is this.
> 
> On Solaris, this code compiles cleanly, and behaves exactly as I want to.

You got lucky, big endian sparc and the junk in the uninitialised
sa struct members meant something to Solaris.

> On OpenBSD, the code compiles cleanly, but still uses random source port.
> On Linux, the code compiles cleanly, but I get the error
> 	Unable to connect(): Invalid argument

You need to fill in the rest of sa, including sin_family to AF_INET
and sin_addr to a valid interface on your machine or INADDR_ANY.

Then you need to set the port number properly:

sa.sin_port=htons(53);

--
	Rob.