[lwip-users] dhcp on multiple interfaces

[Jim Gibbons]

For some time now, one of our clients has been asking for DHCP on both the ethernet interfaces to his system.  We're finally getting around to doing it for him.  This e-mail is an inquiry to determine if this should be done privately, or if it would be of benefit to submit this as a change to lwIP.  I'm also interested to know if anyone has a better implementation idea. Background:  All DHCP transmissions go through udp_send.  udp_send determines the netif to use for the output by calling ip_route.  In the case of a broadcast destination, ip_route selects a single default netif for the transmission (netif_default).  This precludes the use of DHCP on any interface but netif_default. Proposed solution: Create a new function in udp.c named udp_send_if.  This new function will have a linkage like udp_send, but with the addition of a netif parameter.  The body of this new function will be virtually identical to the existing udp_send.  The only difference would be that ip_route would be called only if the incoming netif was NULL.  If an incoming netif is specified, it will be used. Create a new version of udp_send, either as a macro in the udp header or as a function in udp.c.  The implementation will be a call to udp_send_if with a NULL netif parameter, thus forcing the use of ip_route. Put udp_send_if into udp.h. Modify DHCP to use udp_send_if in some (or all) of the instances where it now calls udp_send.  At a minimum, udp_send_if would be used for all broadcasts.  It could probably be used everywhere. -- Jim Gibbons [EMAIL PROTECTED] Gibbons and Associates, Inc. TEL: (408) 984-1441 900 Lafayette, Suite 704, Santa Clara, CA FAX: (408) 247-6395

_______________________________________________
lwip-users mailing list
lwip-users@nongnu.org
http://lists.nongnu.org/mailman/listinfo/lwip-users