linux/net/ipv6, branch v4.6

net/route: enforce hoplimit max value

2016-05-14T19:33:32Z

Currently, when creating or updating a route, no check is performed in both ipv4 and ipv6 code to the hoplimit value. The caller can i.e. set hoplimit to 256, and when such route will be used, packets will be sent with hoplimit/ttl equal to 0. This commit adds checks for the RTAX_HOPLIMIT value, in both ipv4 ipv6 route code, substituting any value greater than 255 with 255. This is consistent with what is currently done for ADVMSS and MTU in the ipv4 code. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

net: ipv6: tcp reset, icmp need to consider L3 domain

2016-05-06T19:49:07Z

Responses for packets to unused ports are getting lost with L3 domains. IPv4 has ip_send_unicast_reply for sending TCP responses which accounts for L3 domains; update the IPv6 counterpart tcp_v6_send_response. For icmp the L3 master check needs to be moved up in icmp6_send to properly respond to UDP packets to a port with no listener. Fixes: ca254490c8df ("net: Add VRF support to IPv6 stack") Signed-off-by: David Ahern Signed-off-by: David S. Miller

ipv6/ila: fix nlsize calculation for lwtunnel

2016-05-03T20:21:33Z

The handler 'ila_fill_encap_info' adds one attribute: ILA_ATTR_LOCATOR. Fixes: 65d7ab8de582 ("net: Identifier Locator Addressing module") CC: Tom Herbert Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller

net: ipv6: Delete host routes on an ifdown

2016-04-26T15:48:26Z

It was a simple idea -- save IPv6 configured addresses on a link down so that IPv6 behaves similar to IPv4. As always the devil is in the details and the IPv6 stack as too many behavioral differences from IPv4 making the simple idea more complicated than it needs to be. The current implementation for keeping IPv6 addresses can panic or spit out a warning in one of many paths: 1. IPv6 route gets an IPv4 route as its 'next' which causes a panic in rt6_fill_node while handling a route dump request. 2. rt->dst.obsolete is set to DST_OBSOLETE_DEAD hitting the WARN_ON in fib6_del 3. Panic in fib6_purge_rt because rt6i_ref count is not 1. The root cause of all these is references related to the host route for an address that is retained. So, this patch deletes the host route every time the ifdown loop runs. Since the host route is deleted and will be re-generated an up there is no longer a need for the l3mdev fix up. On the 'admin up' side move addrconf_permanent_addr into the NETDEV_UP event handling so that it runs only once versus on UP and CHANGE events. All of the current panics and warnings appear to be related to addresses on the loopback device, but given the catastrophic nature when a bug is triggered this patch takes the conservative approach and evicts all host routes rather than trying to determine when it can be re-used and when it can not. That can be a later optimizaton if desired. Signed-off-by: David Ahern Signed-off-by: David S. Miller

Revert "ipv6: Revert optional address flusing on ifdown."

2016-04-26T15:47:41Z

This reverts commit 841645b5f2dfceac69b78fcd0c9050868d41ea61. Ok, this puts the feature back. I've decided to apply David A.'s bug fix and run with that rather than make everyone wait another whole release for this feature. Signed-off-by: David S. Miller

ipv6: Revert optional address flusing on ifdown.

2016-04-25T19:33:55Z

This reverts the following three commits: 70af921db6f8835f4b11c65731116560adb00c14 799977d9aafbf0ca0b9c39b04cbfb16db71302c9 f1705ec197e705b79ea40fe7a2cc5acfa1d3bfac The feature was ill conceived, has terrible semantics, and has added nothing but regressions to the already fragile ipv6 stack. Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") Signed-off-by: David S. Miller

ipv6: udp: Do a route lookup and update during release_cb

2016-04-14T20:29:53Z

This patch adds a release_cb for UDPv6. It does a route lookup and updates sk->sk_dst_cache if it is needed. It picks up the left-over job from ip6_sk_update_pmtu() if the sk was owned by user during the pmtu update. It takes a rcu_read_lock to protect the __sk_dst_get() operations because another thread may do ip6_dst_store() without taking the sk lock (e.g. sendmsg). Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception") Signed-off-by: Martin KaFai Lau Reported-by: Wei Wang Cc: Cong Wang Cc: Eric Dumazet Cc: Wei Wang Signed-off-by: David S. Miller

ipv6: datagram: Update dst cache of a connected datagram sk during pmtu update

2016-04-14T20:29:51Z

There is a case in connected UDP socket such that getsockopt(IPV6_MTU) will return a stale MTU value. The reproducible sequence could be the following: 1. Create a connected UDP socket 2. Send some datagrams out 3. Receive a ICMPV6_PKT_TOOBIG 4. No new outgoing datagrams to trigger the sk_dst_check() logic to update the sk->sk_dst_cache. 5. getsockopt(IPV6_MTU) returns the mtu from the invalid sk->sk_dst_cache instead of the newly created RTF_CACHE clone. This patch updates the sk->sk_dst_cache for a connected datagram sk during pmtu-update code path. Note that the sk->sk_v6_daddr is used to do the route lookup instead of skb->data (i.e. iph). It is because a UDP socket can become connected after sending out some datagrams in un-connected state. or It can be connected multiple times to different destinations. Hence, iph may not be related to where sk is currently connected to. It is done under '!sock_owned_by_user(sk)' condition because the user may make another ip6_datagram_connect() (i.e changing the sk->sk_v6_daddr) while dst lookup is happening in the pmtu-update code path. For the sock_owned_by_user(sk) == true case, the next patch will introduce a release_cb() which will update the sk->sk_dst_cache. Test: Server (Connected UDP Socket): ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Route Details: [root@arch-fb-vm1 ~]# ip -6 r show | egrep '2fac' 2fac::/64 dev eth0 proto kernel metric 256 pref medium 2fac:face::/64 via 2fac::face dev eth0 metric 1024 pref medium A simple python code to create a connected UDP socket: import socket import errno HOST = '2fac::1' PORT = 8080 s = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM) s.bind((HOST, PORT)) s.connect(('2fac:face::face', 53)) print("connected") while True: try: data = s.recv(1024) except socket.error as se: if se.errno == errno.EMSGSIZE: pmtu = s.getsockopt(41, 24) print("PMTU:%d" % pmtu) break s.close() Python program output after getting a ICMPV6_PKT_TOOBIG: [root@arch-fb-vm1 ~]# python2 ~/devshare/kernel/tasks/fib6/udp-connect-53-8080.py connected PMTU:1300 Cache routes after recieving TOOBIG: [root@arch-fb-vm1 ~]# ip -6 r show table cache 2fac:face::face via 2fac::face dev eth0 metric 0 cache expires 463sec mtu 1300 pref medium Client (Send the ICMPV6_PKT_TOOBIG): ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ scapy is used to generate the TOOBIG message. Here is the scapy script I have used: >>> p=Ether(src='da:75:4d:36:ac:32', dst='52:54:00:12:34:66', type=0x86dd)/IPv6(src='2fac::face', dst='2fac::1')/ICMPv6PacketTooBig(mtu=1300)/IPv6(src='2fac:: 1',dst='2fac:face::face', nh='UDP')/UDP(sport=8080,dport=53) >>> sendp(p, iface='qemubr0') Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception") Signed-off-by: Martin KaFai Lau Reported-by: Wei Wang Cc: Cong Wang Cc: Eric Dumazet Cc: Wei Wang Signed-off-by: David S. Miller

ipv6: datagram: Refactor dst lookup and update codes to a new function

2016-04-14T20:29:50Z

This patch moves the route lookup and update codes for connected datagram sk to a newly created function ip6_datagram_dst_update() It will be reused during the pmtu update in the later patch. Signed-off-by: Martin KaFai Lau Cc: Cong Wang Cc: Eric Dumazet Cc: Wei Wang Signed-off-by: David S. Miller

ipv6: datagram: Refactor flowi6 init codes to a new function

2016-04-14T20:29:49Z

Move flowi6 init codes for connected datagram sk to a newly created function ip6_datagram_flow_key_init(). Notes: 1. fl6_flowlabel is used instead of fl6.flowlabel in __ip6_datagram_connect 2. ipv6_addr_is_multicast(&fl6->daddr) is used instead of (addr_type & IPV6_ADDR_MULTICAST) in ip6_datagram_flow_key_init() This new function will be reused during pmtu update in the later patch. Signed-off-by: Martin KaFai Lau Cc: Cong Wang Cc: Eric Dumazet Cc: Wei Wang Signed-off-by: David S. Miller