Hi, In Ubuntu we have applied the attached patch to solve this issue.
Essentially, the DHCP messages need to be broadcast since when there are multiple interfaces, you might otherwise send from a different interface than the one you'll receive responses on while the interfaces are not yet configured. This fixes yiaddr to INADDR_ANY (which was missing for some DHCP message types) and sets the broadcast bit. Kindly, Mathieu Trudel-Lapierre <mathieu...@gmail.com> Freenode: cyphermox, Jabber: mathieu...@gmail.com 4096R/65B58DA1 818A D123 0992 275B 23C2 CF89 C67B B4D6 65B5 8DA1
From: Mathieu Trudel-Lapierre <mathieu.trudel-lapie...@canonical.com> Subject: Set broadcast when sending DHCPREQUEST and DHCPDISCOVER Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=733988 Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/klibc/+bug/1327412 We need to do this, since our devices are probably not configured yet and there may be more than one device we're trying to do DHCP on on the same network. Otherwise, things might be dropped. Patch is originally from here: https://bugs.launchpad.net/ubuntu/+source/klibc/+bug/1327412/comments/5 ... but the reporter "patpat" has not provided contact information, and this is independently verifiable by looking at RFC 2131, section 4.1, page 24. --- usr/kinit/ipconfig/dhcp_proto.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) Index: b/usr/kinit/ipconfig/dhcp_proto.c =================================================================== --- a/usr/kinit/ipconfig/dhcp_proto.c +++ b/usr/kinit/ipconfig/dhcp_proto.c @@ -201,8 +201,14 @@ static int dhcp_send(struct netdev *dev, bootp.hlen = dev->hwlen; bootp.xid = dev->bootp.xid; bootp.ciaddr = INADDR_ANY; - bootp.yiaddr = dev->ip_addr; + /* yiaddr should always be set to 0 for the messages we're likely + * to send as a DHCP client: DHCPDISCOVER, DHCPREQUEST, DHCPDECLINE, + * DHCPINFORM, DHCPRELEASE + * cf. RFC2131 section 4.1.1, table 5. + */ + bootp.yiaddr = INADDR_ANY; bootp.giaddr = INADDR_ANY; + bootp.flags = htons(0x8000); bootp.secs = htons(time(NULL) - dev->open_time); memcpy(bootp.chaddr, dev->hwaddr, 16);
