Date: Thu, 18 Jun 2015 20:43:16 +0000 (UTC) From: Kristof Provost <kp@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r284574 - stable/10/sys/netpfil/pf Message-ID: <201506182043.t5IKhGD9032155@svn.freebsd.org>
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Author: kp Date: Thu Jun 18 20:43:16 2015 New Revision: 284574 URL: https://svnweb.freebsd.org/changeset/base/284574 Log: Merge r281164 pf: Skip firewall for refragmented ip6 packets In cases where we scrub (fragment reassemble) on both input and output we risk ending up in infinite loops when forwarding packets. Fragmented packets come in and get collected until we can defragment. At that point the defragmented packet is handed back to the ip stack (at the pfil point in ip6_input(). Normal processing continues. Eventually we figure out that the packet has to be forwarded and we end up at the pfil hook in ip6_forward(). After doing the inspection on the defragmented packet we see that the packet has been defragmented and because we're forwarding we have to refragment it. In pf_refragment6() we split the packet up again and then ip6_forward() the individual fragments. Those fragments hit the pfil hook on the way out, so they're collected until we can reconstruct the full packet, at which point we're right back where we left off and things continue until we run out of stack. Break that loop by marking the fragments generated by pf_refragment6() as M_SKIP_FIREWALL. There's no point in processing those packets in the firewall anyway. We've already filtered on the full packet. Differential Revision: https://reviews.freebsd.org/D2819 Reviewed by: gnn Modified: stable/10/sys/netpfil/pf/pf_norm.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/netpfil/pf/pf_norm.c ============================================================================== --- stable/10/sys/netpfil/pf/pf_norm.c Thu Jun 18 20:41:55 2015 (r284573) +++ stable/10/sys/netpfil/pf/pf_norm.c Thu Jun 18 20:43:16 2015 (r284574) @@ -1158,6 +1158,7 @@ pf_refragment6(struct ifnet *ifp, struct for (t = m; m; m = t) { t = m->m_nextpkt; m->m_nextpkt = NULL; + m->m_flags |= M_SKIP_FIREWALL; memset(&pd, 0, sizeof(pd)); pd.pf_mtag = pf_find_mtag(m); if (error == 0)
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