linux/net/ipv6
Hannes Frederic Sowa 91a48a2e85 ipv4: ipv6: better estimate tunnel header cut for correct ufo handling
Currently the UFO fragmentation process does not correctly handle inner
UDP frames.

(The following tcpdumps are captured on the parent interface with ufo
disabled while tunnel has ufo enabled, 2000 bytes payload, mtu 1280,
both sit device):

IPv6:
16:39:10.031613 IP (tos 0x0, ttl 64, id 3208, offset 0, flags [DF], proto IPv6 (41), length 1300)
    192.168.122.151 > 1.1.1.1: IP6 (hlim 64, next-header Fragment (44) payload length: 1240) 2001::1 > 2001::8: frag (0x00000001:0|1232) 44883 > distinct: UDP, length 2000
16:39:10.031709 IP (tos 0x0, ttl 64, id 3209, offset 0, flags [DF], proto IPv6 (41), length 844)
    192.168.122.151 > 1.1.1.1: IP6 (hlim 64, next-header Fragment (44) payload length: 784) 2001::1 > 2001::8: frag (0x00000001:0|776) 58979 > 46366: UDP, length 5471

We can see that fragmentation header offset is not correctly updated.
(fragmentation id handling is corrected by 916e4cf46d ("ipv6: reuse
ip6_frag_id from ip6_ufo_append_data")).

IPv4:
16:39:57.737761 IP (tos 0x0, ttl 64, id 3209, offset 0, flags [DF], proto IPIP (4), length 1296)
    192.168.122.151 > 1.1.1.1: IP (tos 0x0, ttl 64, id 57034, offset 0, flags [none], proto UDP (17), length 1276)
    192.168.99.1.35961 > 192.168.99.2.distinct: UDP, length 2000
16:39:57.738028 IP (tos 0x0, ttl 64, id 3210, offset 0, flags [DF], proto IPIP (4), length 792)
    192.168.122.151 > 1.1.1.1: IP (tos 0x0, ttl 64, id 57035, offset 0, flags [none], proto UDP (17), length 772)
    192.168.99.1.13531 > 192.168.99.2.20653: UDP, length 51109

In this case fragmentation id is incremented and offset is not updated.

First, I aligned inet_gso_segment and ipv6_gso_segment:
* align naming of flags
* ipv6_gso_segment: setting skb->encapsulation is unnecessary, as we
  always ensure that the state of this flag is left untouched when
  returning from upper gso segmenation function
* ipv6_gso_segment: move skb_reset_inner_headers below updating the
  fragmentation header data, we don't care for updating fragmentation
  header data
* remove currently unneeded comment indicating skb->encapsulation might
  get changed by upper gso_segment callback (gre and udp-tunnel reset
  encapsulation after segmentation on each fragment)

If we encounter an IPIP or SIT gso skb we now check for the protocol ==
IPPROTO_UDP and that we at least have already traversed another ip(6)
protocol header.

The reason why we have to special case GSO_IPIP and GSO_SIT is that
we reset skb->encapsulation to 0 while skb_mac_gso_segment the inner
protocol of GSO_UDP_TUNNEL or GSO_GRE packets.

Reported-by: Wolfgang Walter <linux@stwm.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-25 18:27:06 -05:00
..
netfilter netfilter: nf_tables: add reject module for NFPROTO_INET 2014-02-06 09:44:18 +01:00
addrconf_core.c ipv6: move in6_dev_finish_destroy() into core kernel 2013-08-31 22:30:00 -04:00
addrconf.c gre: add link local route when local addr is any 2014-02-17 14:08:26 -05:00
addrlabel.c ipv6: fix null pointer dereference in __ip6addrlbl_add 2013-09-04 14:14:53 -04:00
af_inet6.c ipv6: add flowlabel_consistency sysctl 2014-01-19 17:12:31 -08:00
ah6.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
anycast.c ipv6: enable anycast addresses as source addresses for datagrams 2014-01-22 21:57:05 -08:00
datagram.c ipv6: enable anycast addresses as source addresses for datagrams 2014-01-22 21:57:05 -08:00
esp6.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
exthdrs_core.c ipv6: Correct comparisons and calculations using skb->tail and skb-transport_header 2013-05-28 23:49:07 -07:00
exthdrs_offload.c ipv6: Pull IPv6 GSO registration out of the module 2012-11-15 17:39:24 -05:00
exthdrs.c ipv6/exthdrs: accept tlv which includes only padding 2013-09-11 15:52:27 -04:00
fib6_rules.c ipv6: move IPV6_TCLASS_SHIFT into ipv6.h and define a helper 2014-01-15 15:53:18 -08:00
icmp.c ipv6: icmp6_send: fix Oops when pinging a not set up IPv6 peer on a sit tunnel 2014-02-09 18:12:40 -08:00
inet6_connection_sock.c net: Remove FLOWI_FLAG_CAN_SLEEP 2013-12-06 07:24:39 +01:00
inet6_hashtables.c inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once 2013-10-19 19:45:35 -04:00
ip6_checksum.c ipv6: move csum_ipv6_magic() and udp6_csum_init() into static library 2013-01-08 17:56:10 -08:00
ip6_fib.c ipv6: remove prune parameter for fib6_clean_all 2014-01-02 03:30:35 -05:00
ip6_flowlabel.c ipv6: add flowlabel_consistency sysctl 2014-01-19 17:12:31 -08:00
ip6_gre.c ipv6: move IPV6_TCLASS_SHIFT into ipv6.h and define a helper 2014-01-15 15:53:18 -08:00
ip6_icmp.c ipv6: Kill ipv6 dependency of icmpv6_send(). 2013-04-29 13:54:36 -04:00
ip6_input.c net: Fix memory leak if TPROXY used with TCP early demux 2014-01-27 16:22:11 -08:00
ip6_offload.c ipv4: ipv6: better estimate tunnel header cut for correct ufo handling 2014-02-25 18:27:06 -05:00
ip6_offload.h ipv6: Pull IPv6 GSO registration out of the module 2012-11-15 17:39:24 -05:00
ip6_output.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2014-02-19 13:12:53 -05:00
ip6_tunnel.c ipv6: move IPV6_TCLASS_SHIFT into ipv6.h and define a helper 2014-01-15 15:53:18 -08:00
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-01-14 14:42:42 -08:00
ip6mr.c net: avoid reference counter overflows on fib_rules in multicast forwarding 2014-01-14 17:37:25 -08:00
ipcomp6.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
ipv6_sockglue.c ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
Kconfig ipv6: Remove privacy config option. 2013-10-28 20:07:50 -04:00
Makefile ipv6: Add support for IPsec virtual tunnel interfaces 2013-10-10 12:00:01 +02:00
mcast.c ipv6: send Change Status Report after DAD is completed 2014-01-17 18:12:29 -08:00
mip6.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
ndisc.c neigh: use tbl->family to distinguish ipv4 from ipv6 2013-12-09 20:56:12 -05:00
netfilter.c netfilter: add nf_ipv6_ops hook to fix xt_addrtype with IPv6 2013-05-23 11:58:55 +02:00
output_core.c ipv6: move ip6_local_out into core kernel 2013-08-31 22:30:00 -04:00
ping.c ipv6: protect protocols not handling ipv4 from v4 connection/bind attempts 2014-01-21 16:59:19 -08:00
proc.c net: add SNMP counters tracking incoming ECN bits 2013-08-08 22:24:59 -07:00
protocol.c net: remove outdated comment for ipv4 and ipv6 protocol handler 2013-11-28 18:47:51 -05:00
raw.c ipv6: protect protocols not handling ipv4 from v4 connection/bind attempts 2014-01-21 16:59:19 -08:00
reassembly.c ipv6: split inet6_hash_frag for netfilter and initialize secrets with net_get_random_once 2013-10-23 17:01:40 -04:00
route.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-01-06 17:37:45 -05:00
sit.c sit: fix panic with route cache in ip tunnels 2014-02-20 13:13:50 -05:00
syncookies.c net: Remove FLOWI_FLAG_CAN_SLEEP 2013-12-06 07:24:39 +01:00
sysctl_net_ipv6.c ipv6: add flowlabel_consistency sysctl 2014-01-19 17:12:31 -08:00
tcp_ipv6.c tcp: delete redundant calls of tcp_mtup_init() 2014-01-21 16:52:31 -08:00
tcpv6_offload.c net-gro: Prepare GRO stack for the upcoming tunneling support 2013-12-12 13:47:53 -05:00
tunnel6.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
udp_impl.h net: ipv4/ipv6: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
udp_offload.c ipv6: reuse ip6_frag_id from ip6_ufo_append_data 2014-02-22 00:28:21 -05:00
udp.c ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
udplite.c ipv6: do not clear pinet6 field 2013-05-11 16:26:38 -07:00
xfrm6_input.c netfilter: ipv6: use NFPROTO values for NF_HOOK invocation 2010-03-25 16:00:49 +01:00
xfrm6_mode_beet.c ipsec: be careful of non existing mac headers 2012-02-23 16:50:45 -05:00
xfrm6_mode_ro.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c ipv6: Add a receive path hook for vti6 in xfrm6_mode_tunnel. 2013-10-09 13:16:36 +02:00
xfrm6_output.c xfrm: revert ipv4 mtu determination to dst_mtu 2013-08-26 12:40:53 +02:00
xfrm6_policy.c xfrm: Fix null pointer dereference when decoding sessions 2013-11-01 07:08:46 +01:00
xfrm6_state.c xfrm: make local error reporting more robust 2013-08-14 13:07:12 +02:00
xfrm6_tunnel.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00