Date: Sat, 11 Apr 2015 14:26:49 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 199378] [patch] dhclient violates RFC2131 when sending early DHCPREQUEST message to re-obtain old IP Message-ID: <bug-199378-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=199378 Bug ID: 199378 Summary: [patch] dhclient violates RFC2131 when sending early DHCPREQUEST message to re-obtain old IP Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Keywords: patch Severity: Affects Many People Priority: --- Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: fbsd@opal.com Keywords: patch Created attachment 155476 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=155476&action=edit patch to cause early DHCPREQUEST broadcasts to be sent using source IP 0.0.0.0 When dhclient first starts, if an old IP address exists in the dhclient.leases file, dhclient(8) sends early DHCPREQUEST message(s) in an attempt to re-obtain the old IP address again. These messages contain the old IP as a requested-IP-address option in the message body (correct) but the message also uses the old IP address as the packet's source IP (incorrect). RFC2131 sec 4.1 states: DHCP messages broadcast by a client prior to that client obtaining its IP address must have the source address field in the IP header set to 0. The use of the old IP as the packet's source address is incorrect if (a) the computer is now on a different network or (b) it is on the same network, but the old IP has been reallocated to another host. The attached patch fixes things to use 0.0.0.0 as the source IP without removing any existing functionality. Any previously-used old IP is still requested in the body of an early DHCPREQUEST message. -- You are receiving this mail because: You are the assignee for the bug.
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