[syslinux] IP details in COM32 module

[H. Peter Anvin]

Coe, Colin C. (Unix Engineer) wrote:
> Hi all
> 
> I'm trying to resolve a problem that's recently popped up by turning on
> auxillary VLANs for our Linux workstations.  The problem shows as DHCP
> failling for anaconda (but always succeeds for PXE).
> 
> I tried adding 'ipappend 1' to the pxelinux config files but had no joy.
> 
> I'm thinking that if I write a COM32 module that adds "ip=1.2.3.4
> gateway=1.2.3.1 netmask=255.255.255.0 dns= etc" to the end of the append
> line my problem may be solved.  Is there an API call of function to get
> this info?  I've seen the "resolve hostname" (AX=0010h) but it's what
> I'm looking for.
> 

There are two ways to do it.

API 000Fh "get ipappend strings" will give you the ip= string that
ipappend would add.

API 0009h can be used to call the PXE stack and get the entire DHCP packets.

In 3.50-pre* there are library wrappers for these -- they are called
syslinux_ipappend_strings (<syslinux/config.h>) and pxe_get_cached_info
(<syslinux/pxe.h>) repectively.

	-hpa