| Message ID | 1489057006-1254-1-git-send-email-alexey.kodanev@oracle.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Alexey Kodanev <alexey.kodanev@oracle.com> Date: Thu, 9 Mar 2017 13:56:46 +0300 > commit c146066ab802 ("ipv4: Don't use ufo handling on later transformed > packets") and commit f89c56ce710a ("ipv6: Don't use ufo handling on > later transformed packets") added a check that 'rt->dst.header_len' isn't > zero in order to skip UFO, but it doesn't include IPcomp in transport mode > where it equals zero. > > Packets, after payload compression, may not require further fragmentation, > and if original length exceeds MTU, later compressed packets will be > transmitted incorrectly. This can be reproduced with LTP udp_ipsec.sh test > on veth device with enabled UFO, MTU is 1500 and UDP payload is 2000: > > * IPv4 case, offset is wrong + unnecessary fragmentation > udp_ipsec.sh -p comp -m transport -s 2000 & > tcpdump -ni ltp_ns_veth2 > ... > IP (tos 0x0, ttl 64, id 45203, offset 0, flags [+], > proto Compressed IP (108), length 49) > 10.0.0.2 > 10.0.0.1: IPComp(cpi=0x1000) > IP (tos 0x0, ttl 64, id 45203, offset 1480, flags [none], > proto UDP (17), length 21) 10.0.0.2 > 10.0.0.1: ip-proto-17 > > * IPv6 case, sending small fragments > udp_ipsec.sh -6 -p comp -m transport -s 2000 & > tcpdump -ni ltp_ns_veth2 > ... > IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108) > payload length: 37) fd00::2 > fd00::1: IPComp(cpi=0x1000) > IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108) > payload length: 21) fd00::2 > fd00::1: IPComp(cpi=0x1000) > > Fix it by checking 'rt->dst.xfrm' pointer to 'xfrm_state' struct, skip UFO > if xfrm is set. So the new check will include both cases: IPcomp and IPsec. > > Fixes: c146066ab802 ("ipv4: Don't use ufo handling on later transformed packets") > Fixes: f89c56ce710a ("ipv6: Don't use ufo handling on later transformed packets") > Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> > --- > > v2: use dst_xfrm() to access xfrm_state Applied and queued up for -stable, thanks!
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 737ce82..7a3fd25 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -966,7 +966,7 @@ static int __ip_append_data(struct sock *sk, cork->length += length; if ((((length + fragheaderlen) > mtu) || (skb && skb_is_gso(skb))) && (sk->sk_protocol == IPPROTO_UDP) && - (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && + (rt->dst.dev->features & NETIF_F_UFO) && !dst_xfrm(&rt->dst) && (sk->sk_type == SOCK_DGRAM) && !sk->sk_no_check_tx) { err = ip_ufo_append_data(sk, queue, getfrag, from, length, hh_len, fragheaderlen, transhdrlen, diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 528b3c1..df42096 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1385,7 +1385,7 @@ static int __ip6_append_data(struct sock *sk, if ((((length + fragheaderlen) > mtu) || (skb && skb_is_gso(skb))) && (sk->sk_protocol == IPPROTO_UDP) && - (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && + (rt->dst.dev->features & NETIF_F_UFO) && !dst_xfrm(&rt->dst) && (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) { err = ip6_ufo_append_data(sk, queue, getfrag, from, length, hh_len, fragheaderlen, exthdrlen,
commit c146066ab802 ("ipv4: Don't use ufo handling on later transformed packets") and commit f89c56ce710a ("ipv6: Don't use ufo handling on later transformed packets") added a check that 'rt->dst.header_len' isn't zero in order to skip UFO, but it doesn't include IPcomp in transport mode where it equals zero. Packets, after payload compression, may not require further fragmentation, and if original length exceeds MTU, later compressed packets will be transmitted incorrectly. This can be reproduced with LTP udp_ipsec.sh test on veth device with enabled UFO, MTU is 1500 and UDP payload is 2000: * IPv4 case, offset is wrong + unnecessary fragmentation udp_ipsec.sh -p comp -m transport -s 2000 & tcpdump -ni ltp_ns_veth2 ... IP (tos 0x0, ttl 64, id 45203, offset 0, flags [+], proto Compressed IP (108), length 49) 10.0.0.2 > 10.0.0.1: IPComp(cpi=0x1000) IP (tos 0x0, ttl 64, id 45203, offset 1480, flags [none], proto UDP (17), length 21) 10.0.0.2 > 10.0.0.1: ip-proto-17 * IPv6 case, sending small fragments udp_ipsec.sh -6 -p comp -m transport -s 2000 & tcpdump -ni ltp_ns_veth2 ... IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108) payload length: 37) fd00::2 > fd00::1: IPComp(cpi=0x1000) IP6 (flowlabel 0x6b9ba, hlim 64, next-header Compressed IP (108) payload length: 21) fd00::2 > fd00::1: IPComp(cpi=0x1000) Fix it by checking 'rt->dst.xfrm' pointer to 'xfrm_state' struct, skip UFO if xfrm is set. So the new check will include both cases: IPcomp and IPsec. Fixes: c146066ab802 ("ipv4: Don't use ufo handling on later transformed packets") Fixes: f89c56ce710a ("ipv6: Don't use ufo handling on later transformed packets") Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com> --- v2: use dst_xfrm() to access xfrm_state net/ipv4/ip_output.c | 2 +- net/ipv6/ip6_output.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)