On 06/08/2010 02:21 PM, Guy Helmer wrote:
On Jun 8, 2010, at 12:45 PM, Stephen Clark wrote:Hi, Why does FreeBSD 6.3 eat 169.254.x.x addressed packet when 4.9 didn't? ***** 6.3 ***** $ sudo ipfstat -nio empty list for ipfilter(out) empty list for ipfilter(in) Z2984:~ $ ifconfig rl0 rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=8<VLAN_MTU> inet 192.168.129.1 netmask 0xffffff00 broadcast 192.168.129.255 inet 169.254.1.1 netmask 0xffff0000 broadcast 169.254.255.255 ether 00:30:18:ae:7c:77 media: Ethernet autoselect (100baseTX<full-duplex>) status: active Z2984:~ $ ping 169.254.1.1 PING 169.254.1.1 (169.254.1.1): 56 data bytes ^C --- 169.254.1.1 ping statistics --- 4 packets transmitted, 0 packets received, 100% packet loss Z2984:~ $ uname -a FreeBSD Z2984.netwolves.com 6.3-RELEASE-p15 FreeBSD 6.3-RELEASE-p15 #17: Fri Apr 16 12:51:57 EST 2010 **** 4.9 ***** FreeBSD H101494.com 4.9-STABLE FreeBSD 4.9-STABLE #59: Thu Mar 30 13:42:10 EST 2006 r...@a1234.com:/mnt2/src/sys/compile/ i386 H101494# ipf -Fa H101494# ipfstat -nio empty list for ipfilter(out) empty list for ipfilter(in) H101494# ifconfig rl0 rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 inet 10.254.151.1 netmask 0xffffff00 broadcast 10.254.151.255 inet 10.255.3.30 netmask 0xffffffff broadcast 10.255.3.30 inet 10.255.4.30 netmask 0xffffffff broadcast 10.255.4.30 inet 169.254.202.1 netmask 0xffff0000 broadcast 169.254.255.255 ether 00:30:18:a3:49:b5 media: Ethernet autoselect (none) status: no carrier H101494# ping 169.254.202.1 PING 169.254.202.1 (169.254.202.1): 56 data bytes 64 bytes from 169.254.202.1: icmp_seq=0 ttl=64 time=0.052 ms 64 bytes from 169.254.202.1: icmp_seq=1 ttl=64 time=0.080 ms 64 bytes from 169.254.202.1: icmp_seq=2 ttl=64 time=0.081 ms ^C --- 169.254.202.1 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 0.052/0.071/0.081/0.013 msThat was a feature added to sys/netinet/in.c and ip_input.c back in 2007 to obey RFC 3927 not to output datagrams destined for 169.254.0.0/16. On a system that needed to be able to send datagrams to 169.254.0.0/16 addresses, I wrote this patch to add a sysctl knob net.inet.fwd_link_local to dynamically allow a system to send those datagrams: Index: in.c =================================================================== RCS file: /home/ncvs/src/sys/netinet/in.c,v retrieving revision 1.102.2.4.2.1 diff -u -r1.102.2.4.2.1 in.c --- in.c 15 Apr 2009 03:14:26 -0000 1.102.2.4.2.1 +++ in.c 29 Jul 2009 15:10:42 -0000 @@ -67,6 +67,9 @@ struct in_ifaddr *, struct sockaddr_in *, int); static void in_purgemaddrs(struct ifnet *); +int ip_fwdlinklocal = 0; +SYSCTL_INT(_net_inet_ip, OID_AUTO, fwd_link_local, CTLFLAG_RW, + &ip_fwdlinklocal, 0, "Forward link-local addresses"); static int subnetsarelocal = 0; SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW, &subnetsarelocal, 0, "Treat all subnets as directly connected"); @@ -129,7 +132,8 @@ register u_long i = ntohl(in.s_addr); register u_long net; - if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_LINKLOCAL(i)) + if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || + (!ip_fwdlinklocal&& IN_LINKLOCAL(i))) return (0); if (IN_CLASSA(i)) { net = i& IN_CLASSA_NET; Index: ip_input.c =================================================================== RCS file: /home/ncvs/src/sys/netinet/ip_input.c,v retrieving revision 1.332.2.5.2.1 diff -u -r1.332.2.5.2.1 ip_input.c --- ip_input.c 15 Apr 2009 03:14:26 -0000 1.332.2.5.2.1 +++ ip_input.c 29 Jul 2009 15:10:44 -0000 @@ -134,6 +134,7 @@ static struct ifqueue ipintrq; static int ipqmaxlen = IFQ_MAXLEN; +extern int ip_fwdlinklocal; extern struct domain inetdomain; extern struct protosw inetsw[]; u_char ip_protox[IPPROTO_MAX]; @@ -532,7 +533,7 @@ } } /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */ - if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) { + if (!ip_fwdlinklocal&& IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) { ipstat.ips_cantforward++; m_freem(m); return;
Hmmm... how is not responding to pings associated with forwarding? -- "They that give up essential liberty to obtain temporary safety, deserve neither liberty nor safety." (Ben Franklin) "The course of history shows that as a government grows, liberty decreases." (Thomas Jefferson) _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
