linux/include/net
Florian Westphal d6b915e29f ip_fragment: don't forward defragmented DF packet
We currently always send fragments without DF bit set.

Thus, given following setup:

mtu1500 - mtu1500:1400 - mtu1400:1280 - mtu1280
   A           R1              R2         B

Where R1 and R2 run linux with netfilter defragmentation/conntrack
enabled, then if Host A sent a fragmented packet _with_ DF set to B, R1
will respond with icmp too big error if one of these fragments exceeded
1400 bytes.

However, if R1 receives fragment sizes 1200 and 100, it would
forward the reassembled packet without refragmenting, i.e.
R2 will send an icmp error in response to a packet that was never sent,
citing mtu that the original sender never exceeded.

The other minor issue is that a refragmentation on R1 will conceal the
MTU of R2-B since refragmentation does not set DF bit on the fragments.

This modifies ip_fragment so that we track largest fragment size seen
both for DF and non-DF packets, and set frag_max_size to the largest
value.

If the DF fragment size is larger or equal to the non-df one, we will
consider the packet a path mtu probe:
We set DF bit on the reassembled skb and also tag it with a new IPCB flag
to force refragmentation even if skb fits outdev mtu.

We will also set DF bit on each fragment in this case.

Joint work with Hannes Frederic Sowa.

Reported-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-27 13:03:31 -04:00
..
9p 9p: switch p9_client_read() to passing struct iov_iter * 2015-04-11 22:28:27 -04:00
bluetooth Bluetooth: Read LE remote features during connection establishment 2015-04-09 08:36:54 +03:00
caif caif: fix a signedness bug in cfpkt_iterate() 2015-02-20 17:35:14 -05:00
irda irda: Convert function pointer arrays and uses to const 2014-12-10 15:33:16 -05:00
iucv af_iucv: fix recvmsg by replacing skb_pull() function 2013-04-08 17:16:57 -04:00
netfilter netfilter: nf_tables: mark stateful expressions 2015-04-13 20:12:31 +02:00
netns tcp: add rfc3168, section 6.1.1.1. fallback 2015-05-19 16:53:37 -04:00
nfc nfc: nci: Add comment to explain NCI_HCI_MAX_PIPES 2015-04-06 00:19:05 +02:00
phonet
sctp sctp: avoid to repeatedly declare external variables 2015-03-25 11:40:16 -04:00
tc_act act_bpf: add initial eBPF support for actions 2015-03-20 19:10:44 -04:00
6lowpan.h ieee802154: 6lowpan: rename process_data and lowpan_process_data 2014-10-27 15:51:16 +01:00
act_api.h net_sched: act: refuse to remove bound action outside 2014-02-12 19:23:32 -05:00
addrconf.h net: Export IGMP/MLD message validation code 2015-05-04 14:49:23 -04:00
af_ieee802154.h ieee802154: mac802154: remove FSF address 2014-10-25 08:07:30 +02:00
af_rxrpc.h af_rxrpc.h: Remove extern from function prototypes 2013-07-31 17:50:01 -07:00
af_unix.h af_unix: improve STREAM behavior with fragmented memory 2013-08-10 01:16:44 -07:00
af_vsock.h net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
ah.h ipsec: Remove obsolete MAX_AH_AUTH_LEN 2014-09-18 10:54:36 +02:00
arp.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
atmclip.h
ax25.h ax25: Stop using magic neighbour cache operations. 2015-03-03 14:44:41 -05:00
ax88796.h
bond_3ad.h bonding: Implement port churn-machine (AD standard 43.4.17). 2015-02-24 16:05:48 -05:00
bond_alb.h net: Move bonding headers under include/net 2014-11-10 13:27:49 -05:00
bond_options.h bonding: Implement user key part of port_key in an AD system. 2015-05-11 10:59:32 -04:00
bonding.h bonding: Implement user key part of port_key in an AD system. 2015-05-11 10:59:32 -04:00
busy_poll.h sched, net: Fixup busy_loop_us_clock() 2014-01-13 17:39:11 +01:00
cfg80211-wext.h
cfg80211.h cfg80211: change GO_CONCURRENT to IR_CONCURRENT for STA 2015-05-06 15:50:02 +02:00
cfg802154.h cfg802154: pass name_assign_type to rdev_add_virtual_intf() 2015-04-30 18:48:10 +02:00
checksum.h net: fix sparse error in csum_replace4() 2015-05-17 13:08:29 -04:00
cipso_ipv4.h cipso: don't use IPCB() to locate the CIPSO IP option 2015-02-11 14:46:37 -05:00
cls_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
codel.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-05-13 14:31:43 -04:00
compat.h net: switch importing msghdr from userland to {compat_,}import_iovec() 2015-04-09 00:02:26 -04:00
datalink.h net: Move prototype declaration to header file include/net/datalink.h from net/ipx/af_ipx.c 2014-02-09 17:32:50 -08:00
dcbevent.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
dcbnl.h net/dcb: Add IEEE QCN attribute 2015-03-06 21:50:02 -05:00
dn_dev.h dn_dev: add support for IFA_FLAGS nl attribute 2013-12-10 21:50:00 -05:00
dn_fib.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_neigh.h netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
dn_nsp.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_route.h net: Move prototype declaration to appropriate header file from decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dn.h 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
dsa.h net: dsa: Add basic framework to support ndo_fdb functions 2015-03-29 13:23:54 -07:00
dsfield.h ipv6: Optimize ipv6_change_dsfield(). 2013-01-09 23:59:53 -08:00
dst_ops.h net: Remove protocol from struct dst_ops 2015-03-09 16:06:10 -04:00
dst.h net: make skb_dst_pop routine static 2015-05-12 23:19:49 -04:00
esp.h net: move pskb_put() to core code 2013-11-07 19:28:58 -05:00
ethoc.h net: ethoc: set up MII management bus clock 2014-02-04 20:19:51 -08:00
fib_rules.h net: Kill hold_net release_net 2015-03-12 14:39:40 -04:00
firewire.h firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection. 2013-03-26 12:32:13 -04:00
flow_dissector.h flow_dissector: change port array into src, dst tuple 2015-05-13 15:19:47 -04:00
flow.h ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif 2014-04-16 15:05:11 -04:00
flowcache.h flowcache: Make flow cache name space aware 2014-02-12 07:02:11 +01:00
fou.h ip_tunnel: Ops registration for secondary encap (fou, gue) 2014-11-12 15:01:35 -05:00
garp.h garp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
gen_stats.h net: sched: enable per cpu qstats 2014-09-30 01:02:26 -04:00
genetlink.h net: Introduce possible_net_t 2015-03-12 14:39:40 -04:00
geneve.h geneve: move definition of geneve_hdr() to geneve.h 2015-05-13 15:59:13 -04:00
gre.h gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
gro_cells.h ip_tunnel: Create percpu gro_cell 2015-01-18 01:56:32 -05:00
gue.h gue: Protocol constants for remote checksum offload 2014-11-05 16:30:03 -05:00
icmp.h icmp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
ieee80211_radiotap.h mac80211: propagate STBC / LDPC flags to radiotap 2014-02-06 09:34:58 +01:00
ieee802154_netdev.h ieee802154: rework cca setting 2014-12-19 00:19:23 +01:00
if_inet6.h ipv6: do retries on stable privacy addresses 2015-03-23 22:12:09 -04:00
inet_common.h net: Modify sk_alloc to not reference count the netns of kernel sockets. 2015-05-11 10:50:18 -04:00
inet_connection_sock.h inet: properly align icsk_ca_priv 2015-05-19 11:08:00 -04:00
inet_ecn.h tunnel: fix RFC number in comment for INET_ECN_decapsulate() 2014-05-07 15:30:52 -04:00
inet_frag.h ip_fragment: don't forward defragmented DF packet 2015-05-27 13:03:31 -04:00
inet_hashtables.h tcp: fix/cleanup inet_ehash_locks_alloc() 2015-05-26 19:48:46 -04:00
inet_sock.h inet: fix request sock refcounting 2015-03-17 22:02:29 -04:00
inet_timewait_sock.h tcp/dccp: get rid of central timewait timer 2015-04-13 16:40:05 -04:00
inet6_connection_sock.h inet: get rid of central tcp/dccp listener timer 2015-03-20 12:40:25 -04:00
inet6_hashtables.h ipv6: get rid of __inet6_hash() 2015-03-18 22:00:35 -04:00
inetpeer.h tcp: simplify inetpeer_addr_base use 2015-03-31 13:58:35 -04:00
ip_fib.h ipv4: FIB Local/MAIN table collapse 2015-03-11 16:22:14 -04:00
ip_tunnels.h ipip,gre,vti,sit: implement ndo_get_iflink 2015-04-02 14:05:00 -04:00
ip_vs.h net: Introduce possible_net_t 2015-03-12 14:39:40 -04:00
ip.h ip_fragment: don't forward defragmented DF packet 2015-05-27 13:03:31 -04:00
ip6_checksum.h net: add gro_compute_pseudo functions 2014-08-24 18:09:23 -07:00
ip6_fib.h ipv6: Create percpu rt6_info 2015-05-25 13:25:35 -04:00
ip6_route.h ipv6: Add rt6_get_cookie() function 2015-05-25 13:25:34 -04:00
ip6_tunnel.h udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
ipcomp.h
ipconfig.h
ipv6.h ipv6: ipv6_select_ident() returns a __be32 2015-05-25 20:27:11 -04:00
ipx.h switch ipxrtr_route_packet() from iovec to msghdr 2014-11-24 04:28:49 -05:00
iw_handler.h wext: add checked wrappers for adding events/points to streams 2015-02-28 21:31:12 +01:00
lapb.h lapb.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
lib80211.h lib80211: remove unused print_ssid() 2014-10-14 02:18:27 +02:00
llc_c_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_c_st.h llc: Make llc_conn_ev_qfyr_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_conn.h net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
llc_if.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_pdu.h net: llc: fix order of evaluation in llc_conn_ac_inc_vr_by_1 2014-01-01 22:22:43 -05:00
llc_s_ac.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_ev.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc_s_st.h llc: Make llc_sap_action_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_sap.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
llc.h llc: make lock static 2014-01-03 20:56:48 -05:00
mac80211.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-05-13 14:31:43 -04:00
mac802154.h mac802154: add description to mac802154 APIs 2015-04-30 18:48:09 +02:00
mip6.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
mld.h ipv6: mld: answer mldv2 queries with mldv1 reports in mldv1 fallback 2014-09-22 16:23:15 -04:00
mpls.h openvswitch: Add basic MPLS support to kernel 2014-11-05 23:52:33 -08:00
mrp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-01 17:06:14 -04:00
ndisc.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
neighbour.h net: neighbour: Add mcast_resolicit to configure the number of multicast resolicitations in PROBE state. 2015-03-20 21:47:40 -04:00
net_namespace.h netns: make nsid_lock per net 2015-05-17 23:41:11 -04:00
net_ratelimit.h
netevent.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netlabel.h netlabel: fix the netlbl_catmap_setlong() dummy function 2014-08-07 20:55:21 -04:00
netlink.h netlink: implement nla_get_in_addr and nla_get_in6_addr 2015-03-31 13:58:35 -04:00
netprio_cgroup.h cgroup: clean up cgroup_subsys names and initialization 2014-02-08 10:36:58 -05:00
netrom.h netrom.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
nexthop.h
nl802154.h nl802154: introduce support for cca settings 2014-12-19 00:19:23 +01:00
p8022.h p8022.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
ping.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
pkt_cls.h net: sched: remove tcf_proto from ematch calls 2014-10-06 18:02:32 -04:00
pkt_sched.h net: rename vlan_tx_* helpers since "tx" is misleading there 2015-01-13 17:51:08 -05:00
protocol.h net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
psnap.h psnap.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
raw.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
rawv6.h raw/rawv6.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
red.h reciprocal_divide: update/correction of the algorithm 2014-01-21 23:17:20 -08:00
regulatory.h cfg80211: allow wiphy specific regdomain management 2014-12-17 11:49:55 +01:00
request_sock.h tcp: provide SYN headers for passive connections 2015-05-05 16:02:34 -04:00
rose.h rose.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
route.h ipv4: per cpu uncached list 2015-01-15 18:26:16 -05:00
rtnetlink.h rtnetlink: Mark name argument of rtnl_create_link() const 2015-04-10 12:42:40 -07:00
sch_generic.h net: sched: use counter to break reclassify loops 2015-05-13 15:08:14 -04:00
scm.h scm.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
secure_seq.h inetpeer: get rid of ip_id_count 2014-06-02 11:00:41 -07:00
slhc_vj.h
snmp.h Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
sock.h tcp: add a force_schedule argument to sk_stream_alloc_skb() 2015-05-21 16:56:40 -04:00
Space.h drivers: net: Include new header file in sbni.c 2013-12-19 18:51:20 -05:00
stp.h stp.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
switchdev.h switchdev: add support for fdb add/del/dump via switchdev_port_obj ops. 2015-05-17 22:49:09 -04:00
tcp_memcontrol.h tcp_memcontrol: Kill struct tcp_memcontrol 2013-10-21 18:43:02 -04:00
tcp_states.h inet: add TCP_NEW_SYN_RECV state 2015-03-12 22:58:12 -04:00
tcp.h tcp: add rfc3168, section 6.1.1.1. fallback 2015-05-19 16:53:37 -04:00
timewait_sock.h
transp_v6.h ipv6: make IPV6_RECVPKTINFO work for ipv4 datagrams 2014-01-19 19:53:18 -08:00
tso.h net: Add a software TSO helper API 2014-05-22 14:57:15 -04:00
udp_tunnel.h udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
udp.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udplite.h net: switch memcpy_fromiovec()/memcpy_fromiovecend() users to copy_from_iter() 2015-02-04 01:34:15 -05:00
vsock_addr.h VSOCK: Move af_vsock.h and vsock_addr.h to include/net 2013-07-27 22:14:06 -07:00
vxlan.h udp_tunnel: Pass UDP socket down through udp_tunnel{, 6}_xmit_skb(). 2015-04-07 15:29:08 -04:00
wext.h wext.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
wimax.h net: treewide: Fix typo found in DocBook/networking.xml 2014-09-05 17:35:28 -07:00
x25.h x25.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
x25device.h
xfrm.h netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00