linux/net
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
..
9p 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers 2014-02-10 17:48:54 -08:00
802 neigh: use NEIGH_VAR_INIT in ndo_neigh_setup functions. 2014-01-16 11:31:58 -08:00
8021q 8021q: Use ether_addr_copy 2014-01-21 18:13:04 -08:00
appletalk net: Fix some fallout from the etner_addr_copy() changes. 2014-01-21 18:57:26 -08:00
atm net: Fix some fallout from the etner_addr_copy() changes. 2014-01-21 18:57:26 -08:00
ax25 net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
batman-adv batman-adv: fix potential kernel paging error for unicast transmissions 2014-02-17 17:17:02 +01:00
bluetooth Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2014-02-18 16:29:46 -08:00
bridge bridge: Prevent possible race condition in br_fdb_change_mac_address 2014-02-10 14:34:34 -08:00
caif net: Include appropriate header file in caif/cfsrvl.c 2014-02-09 17:32:49 -08:00
can linux-can-fixes-for-3.14-20140129 2014-01-30 16:48:17 -08:00
ceph libceph: do not dereference a NULL bio pointer 2014-02-07 11:37:07 -08:00
core neigh: fix setting of default gc_* values 2014-02-22 00:08:10 -05:00
dcb dcb: use __dev_get_by_name instead of dev_get_by_name to find interface 2014-01-14 18:50:46 -08:00
dccp dccp: re-enable debug macro 2014-02-16 23:45:00 -05:00
decnet net: Move prototype declaration to header file include/net/dn.h from net/decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dns_resolver net/*: Fix FSF address in file headers 2013-12-06 12:37:57 -05:00
dsa dsa: Use ether_addr_copy 2014-01-21 18:13:05 -08:00
ethernet net: eth_type_trans() should use skb_header_pointer() 2014-01-16 15:30:31 -08:00
hsr net/hsr: using kfree_rcu() to simplify the code 2013-12-17 16:32:30 -05:00
ieee802154 6lowpan: fix lockdep splats 2014-02-10 17:51:29 -08:00
ipv4 ipv4: ipv6: better estimate tunnel header cut for correct ufo handling 2014-02-25 18:27:06 -05:00
ipv6 ipv4: ipv6: better estimate tunnel header cut for correct ufo handling 2014-02-25 18:27:06 -05:00
ipx net: Move prototype declaration to header file include/net/net_namespace.h from net/ipx/af_ipx.c 2014-02-09 17:32:50 -08:00
irda net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
iucv net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
key xfrm: export verify_userspi_info for pkfey and netlink interface 2013-12-16 12:54:02 +01:00
l2tp ipv6: protect protocols not handling ipv4 from v4 connection/bind attempts 2014-01-21 16:59:19 -08:00
lapb
llc llc: remove noisy WARN from llc_mac_hdr_init 2014-01-28 18:01:32 -08:00
mac80211 netdevice: add queue selection fallback handler for ndo_select_queue 2014-02-17 00:36:34 -05:00
mac802154 mac802154: fix following checkpath.pl warning Prefer pr_warn(... to pr_warning(... 2013-12-22 18:53:08 -05:00
mpls ipip: add GSO/TSO support 2013-10-19 19:36:19 -04:00
netfilter netfilter: ctnetlink: force null nat binding on insert 2014-02-18 00:13:51 +01:00
netlabel netlabel: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
netlink net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
netrom net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
openvswitch openvswitch: Suppress error messages on megaflow updates 2014-02-04 22:32:38 -08:00
packet af_packet: remove a stray tab in packet_set_ring() 2014-02-18 18:02:25 -05:00
phonet net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
rds net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
rfkill Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
rose net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
rxrpc RxRPC fixes 2014-01-28 18:04:18 -08:00
sched net: sched: Cleanup PIE comments 2014-02-13 18:29:58 -05:00
sctp net: sctp: rework multihoming retransmission path selection to rfc4960 2014-02-22 00:26:05 -05:00
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-02-11 12:05:55 -08:00
tipc tipc: make bearer set up in module insertion stage 2014-02-22 00:00:15 -05:00
unix net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
vmw_vsock net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
wimax wimax: remove dead code 2013-11-21 13:09:42 -05:00
wireless cfg80211: send scan results from work queue 2014-02-06 09:55:19 +01:00
x25 net: add build-time checks for msg->msg_name size 2014-01-18 23:04:16 -08:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
compat.c x86, x32: Correct invalid use of user timespec in the kernel 2014-01-30 18:44:13 -08:00
Kconfig net: netprio: rename config to be more consistent with cgroup configs 2014-01-03 23:41:42 +01:00
Makefile net: move 6lowpan compression code to separate module 2014-01-15 15:36:38 -08:00
nonet.c
socket.c net: handle error more gracefully in socketpair() 2013-12-10 22:24:13 -05:00
sysctl_net.c net: Update the sysctl permissions handler to test effective uid/gid 2013-10-07 15:57:56 -04:00