RE: Socket programming in RPG (C runtime) and IPv6

Thanks Scott,

Yes, Unix-type API's. Everything I think I know about sockets in RPG I
learned from you, so... <g>

I will review your (obviously newer than the ones I've been using)
copybooks, and review documentation from IBM. I actually found some
decent documentation from IBM that covers IPv6 development, but I
thought it was worth checking with the community before I dive into
this.

I'm having trouble getting a feel for the risk associated with IPv6. Is
this an issue I need to be looking into now, or can I safely ignore it
as everyone else seems to be doing? What happens if a site I need to
access changes to IPv6 addressing?

Thanks again for sharing your expertise with us.
-Eric DeLong

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Scott Klement
Sent: Monday, November 15, 2010 6:15 PM
To: RPG programming on the IBM i / System i
Subject: Re: Socket programming in RPG (C runtime) and IPv6

I assume you mean using the Unix-type APIs. (I'm not aware of any way
to do socket programming with the C run-time -- and I thought I was
pretty good at sockets!)

I've written the prototypes/constants/structures for IPv6 into my
SOCKET_H member. You can get them here:

http://www.scottklement.com/rpg/copybooks/socket_h.rpgle.txt

Unfortunately, at this point, they're all untested. I don't currently
have access to an IPv6 network, so I have no way to test my code.

Here are a few salient points:

1) You should replace inet_addr(), gethostbyname() and getservbyname(),
gethostbyaddr() with a calls to getaddrinfo() and getnameinfo(). (This
will work with IPv4 as well... but does require v5r2.

2) For IPv6, you'll want to use AF_INET6 and IPPROTO_IPV6 instead of
AF_INET and IPPROTO_IP when calling the socket() API.

3) Use structure sockaddr_in6 in place of sockaddr_in when calling
connect(), bind(), or accept().

4) recv(), send(), close() should work the same as before.

5) You must call freeaddrinfo() to free up memory used by getaddrinfo().

Good luck


On 11/15/2010 5:45 PM, DeLong, Eric wrote:

I've been looking at documentation relating to IPv6, and realize that
any sockets applications that I've written will need to be modified to
work with IPv6 addressing. Has anyone gone through this, and could
offer any tips or sample code? I am just wanting to be prepared for
this for when we're forced to switch. I sometimes wonder if I'm
misunderstanding this whole IPv6 issue, since I don't see anyone here
who seem to be coding for it. Am I jumping to unwarranted

conclusions,

or will this transition to IPv6 be another bloody mess?