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From: bugzilla-daemon@bugs.ecos.sourceware.org To: ecos-bugs@ecos.sourceware.org Subject: [Bug 1001177] New: Redboot DHCP client race condition, XID, and retry problems. Date: Mon, 21 Mar 2011 14:50:00 -0000 [thread overview] Message-ID: <bug-1001177-13@http.bugs.ecos.sourceware.org/> (raw) Please do not reply to this email. Use the web interface provided at: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001177 Summary: Redboot DHCP client race condition, XID, and retry problems. Product: eCos Version: CVS Platform: All OS/Version: All Status: NEW Severity: normal Priority: low Component: RedBoot AssignedTo: unassigned@bugs.ecos.sourceware.org ReportedBy: grant.b.edwards@gmail.com CC: ecos-bugs@ecos.sourceware.org Class: Advice Request Redboot's DHCP implementation has multiple problems: 1) Received BOOTP packets overwrite the stored configuration information regardless of their XID, the destination MAC address, the type of the packet, or the state of the DHCP FSM. Because of they way the state machine and packet handling is split between the receive packet handler and the foreground loop, this can result in corruption of the IP configuration and failure to obtian an IP address. 2) The retry mechanism doesn't work. The retry counter is decremented at an inappropriate point in the code -- resulting in the counter being decremented multiple times during a single DHCP transaction. At one point in the transaction the retry counter also gets reset back to it's max value. Between these two bugs there are failure cases where no retries are performed at all and cases where the state machine goes into an infinite loop retrying indefinitely. 3) Although the DHCP spec says the XID should be chosen so as to be unique, the XID used is a hard-wired constant that's always the same -- this can result in problems if multiple devices are started simultaneously. 4) The XID on received packets is not verified, and the XID sent in the REQUEST packet is copied from the OFFER packet regardless of what the original XID was in the DISCOVER packet. I've completely re-written the BOOTP/DHCP support to fix the above problems and an currently testing it. -- Configure bugmail: http://bugs.ecos.sourceware.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
next reply other threads:[~2011-03-21 14:50 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-03-21 14:50 bugzilla-daemon [this message] 2011-03-24 14:35 ` [Bug 1001177] " bugzilla-daemon 2011-03-24 17:37 ` bugzilla-daemon 2011-03-24 17:37 ` bugzilla-daemon 2011-03-24 17:37 ` bugzilla-daemon 2011-03-24 18:12 ` bugzilla-daemon 2011-03-24 19:33 ` bugzilla-daemon 2011-03-24 19:36 ` bugzilla-daemon 2011-03-25 16:20 ` bugzilla-daemon 2011-03-26 2:17 ` bugzilla-daemon 2011-03-26 4:21 ` bugzilla-daemon 2011-03-26 18:01 ` bugzilla-daemon 2011-06-08 16:13 ` bugzilla-daemon 2012-03-02 21:10 ` bugzilla-daemon 2012-03-03 3:44 ` bugzilla-daemon 2012-03-03 3:44 ` bugzilla-daemon 2012-03-06 16:47 ` bugzilla-daemon -- strict thread matches above, loose matches on Subject: below -- 2011-03-21 14:50 [Bug 1001177] New: " bugzilla-daemon
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