On 03/27/2012 12:53 AM, Floris Bos / Maxnet wrote:
Is there any way to determinate the IP-address of the proxy DHCP/TFTP
server that was used when booting iPXE in an ipxe script?
Tried (with undionly.kkpxe):
==
set use-cached 1
dhcp
show next-server
==
But it shows me the IP of the regular DHCP server, not the TFTP/proxy
dhcp server (running dnsmasq) which I'm looking for.
Some more information:
Syslinux's Pxelinux does display the correct IP address.
I suspect iPXE's behavior of providing the wrong cached next-server
address when a proxy DHCP server is used in addition to a regular DHCP
server, is caused by it only fetching the cached DHCP ack packet in
src/arch/i386/interface/pxeparent/pxeparent_dhcp.c:
===
/* Obtain cached DHCP packet */
memset ( &get_cached_info, 0, sizeof ( get_cached_info ) );
get_cached_info.PacketType = PXENV_PACKET_TYPE_DHCP_ACK;
if ( ( rc = pxeparent_call ( undi->entry, PXENV_GET_CACHED_INFO,
&get_cached_info,
sizeof ( get_cached_info ) ) ) != 0 ) {
DBG ( "PXEDHCP GET_CACHED_INFO failed: %s\n", strerror ( rc ) );
return;
}
===
While Pxelinux not only fetches and parses the cached
PXENV_PACKET_TYPE_DHCP_ACK (2) but also PXENV_PACKET_TYPE_CACHED_REPLY (3)
===
/*
* Get the BOOTP/DHCP packet that brought us file (and an IP
* address). This lives in the DHCPACK packet (query info 2)
*/
pkt_len = pxe_get_cached_info(2);
parse_dhcp(pkt_len);
/*
* Save away MAC address (assume this is in query info 2. If this
* turns out to be problematic it might be better getting it from
* the query info 1 packet
*/
MAC_len = bp->hardlen > 16 ? 0 : bp->hardlen;
MAC_type = bp->hardware;
memcpy(MAC, bp->macaddr, MAC_len);
/*
* Get the boot file and other info. This lives in the CACHED_REPLY
* packet (query info 3)
*/
pkt_len = pxe_get_cached_info(3);
parse_dhcp(pkt_len);
printf("\n");
===
Yours sincerely,
Floris Bos
_______________________________________________
ipxe-devel mailing list
ipxe-devel@lists.ipxe.org
https://lists.ipxe.org/mailman/listinfo/ipxe-devel
