[dhcp] Assume PXE options are in DHCPOFFER only if boot menu is included

IBM's Tivoli Provisioning Manager for OS Deployment, when acting as a
ProxyDHCP server, sends an initial offer with a vendor class of "PXEClient"
and vendor-encapsulated options that have nothing to do with PXE. To
differentiate between this case and the case of a ProxyDHCP server that
sends all PXE options in its initial offer, modify gPXE to check for
the presence of an encapsulated PXE boot menu option (43.9) instead of
simply checking for the existence of any encapsulated options at all.
This is the same check used by the Intel vendor PXE ROM.

Signed-off-by: Marty Connor <mdc@etherboot.org>

diff --git a/src/net/udp/dhcp.c b/src/net/udp/dhcp.c
index ac4f82c2cee3287ca55f3d443d13c841a9387d15..aba90002a7ca659a1de462fe29fe902ea85aef3e 100644 (file)
--- a/src/net/udp/dhcp.c
+++ b/src/net/udp/dhcp.c
@@ -361,8 +361,8 @@ static void dhcp_discovery_rx ( struct dhcp_session *dhcp,
        has_pxeclient = ( ( vci_len >= ( int ) sizeof ( vci ) ) &&
                          ( strncmp ( "PXEClient", vci, sizeof (vci) ) == 0 ));
 
-       /* Identify presence of vendor-specific options */
-       pxeopts_len = dhcppkt_fetch ( dhcppkt, DHCP_VENDOR_ENCAP, NULL, 0 );
+       /* Identify presence of PXE-specific options */
+       pxeopts_len = dhcppkt_fetch ( dhcppkt, DHCP_PXE_BOOT_MENU, NULL, 0 );
        has_pxeopts = ( pxeopts_len >= 0 );
        if ( has_pxeclient )
                DBGC ( dhcp, "%s", ( has_pxeopts ? " pxe" : " proxy" ) );