linux/include/net
Hannes Frederic Sowa f87c10a8aa ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing
While forwarding we should not use the protocol path mtu to calculate
the mtu for a forwarded packet but instead use the interface mtu.

We mark forwarded skbs in ip_forward with IPSKB_FORWARDED, which was
introduced for multicast forwarding. But as it does not conflict with
our usage in unicast code path it is perfect for reuse.

I moved the functions ip_sk_accept_pmtu, ip_sk_use_pmtu and ip_skb_dst_mtu
along with the new ip_dst_mtu_maybe_forward to net/ip.h to fix circular
dependencies because of IPSKB_FORWARDED.

Because someone might have written a software which does probe
destinations manually and expects the kernel to honour those path mtus
I introduced a new per-namespace "ip_forward_use_pmtu" knob so someone
can disable this new behaviour. We also still use mtus which are locked on a
route for forwarding.

The reason for this change is, that path mtus information can be injected
into the kernel via e.g. icmp_err protocol handler without verification
of local sockets. As such, this could cause the IPv4 forwarding path to
wrongfully emit fragmentation needed notifications or start to fragment
packets along a path.

Tunnel and ipsec output paths clear IPCB again, thus IPSKB_FORWARDED
won't be set and further fragmentation logic will use the path mtu to
determine the fragmentation size. They also recheck packet size with
help of path mtu discovery and report appropriate errors.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: John Heffner <johnwheffner@gmail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-13 11:22:54 -08:00
..
9p for-linus-3.12-merge minor 9p fixes and tweaks for 3.12 merge window 2013-09-11 12:34:13 -07:00
bluetooth Bluetooth: Add quirk for disabling Delete Stored Link Key command 2014-01-04 20:10:40 +02:00
caif caif_hsi.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
irda include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
iucv af_iucv: fix recvmsg by replacing skb_pull() function 2013-04-08 17:16:57 -04:00
netfilter netfilter: nf_tables: rename nft_do_chain_pktinfo() to nft_do_chain() 2014-01-09 20:17:16 +01:00
netns ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing 2014-01-13 11:22:54 -08:00
nfc include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
phonet net: remove my future former mail address 2012-06-17 16:29:38 -07:00
sctp Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-01-06 17:37:45 -05:00
tc_act include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
act_api.h sched action: make local function static 2014-01-02 03:30:36 -05:00
addrconf.h neigh: ipv6: respect default values set before an address is assigned to device 2013-12-09 20:56:12 -05:00
af_ieee802154.h
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 VSOCK: Move af_vsock.h and vsock_addr.h to include/net 2013-07-27 22:14:06 -07:00
ah.h
arp.h arp: make arp_invalidate static 2013-12-28 17:02:46 -05:00
atmclip.h atm: clip: Use device neigh support on top of "arp_tbl". 2011-11-30 18:51:03 -05:00
ax25.h ax25.h: Remove extern from function prototypes 2013-07-31 17:50:02 -07:00
ax88796.h
busy_poll.h net: add cpu_relax to busy poll loop 2013-08-28 17:45:48 -04:00
cfg80211-wext.h
cfg80211.h cfg80211: Add support for QoS mapping 2013-12-19 16:29:22 +01:00
checksum.h net: checksum: fix warning in skb_checksum 2013-11-04 15:27:08 -05:00
cipso_ipv4.h cipso: cleanup cipso_v4_translate() when !CONFIG_NETLABEL 2013-12-10 17:56:54 -05:00
cls_cgroup.h net: net_cls: move cgroupfs classid handling into core 2014-01-03 23:41:41 +01:00
codel.h net: codel: Avoid undefined behavior from signed overflow 2013-11-04 20:01:29 -05:00
compat.h compat.h: Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
datalink.h
dcbevent.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
dcbnl.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -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 decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_nsp.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn_route.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dn.h decnet (dn*.h): Remove extern from function prototypes 2013-09-20 14:49:32 -04:00
dsa.h dsa: Include linux/if_ether.h to fix build error 2011-12-01 11:41:06 -05:00
dsfield.h ipv6: Optimize ipv6_change_dsfield(). 2013-01-09 23:59:53 -08:00
dst_ops.h net: Fix warnings in dst_ops.h 2012-07-19 10:43:03 -07:00
dst.h net: Add utility functions to clear rxhash 2013-12-17 16:36:21 -05:00
esp.h net: move pskb_put() to core code 2013-11-07 19:28:58 -05:00
ethoc.h
fib_rules.h fib_rules.h: Remove extern from function prototypes 2013-09-20 14:49:33 -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_keys.h flow_dissector: factor out the ports extraction in skb_flow_get_ports 2013-10-03 15:36:37 -04:00
flow.h net: Remove FLOWI_FLAG_CAN_SLEEP 2013-12-06 07:24:39 +01:00
garp.h garp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
gen_stats.h gen_stats.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
genetlink.h genl: Add genlmsg_new_unicast() for unicast message allocation 2014-01-06 15:51:53 -08:00
gre.h gre_offload: statically build GRE offloading support 2014-01-06 20:28:34 -05:00
gro_cells.h gro: Fix kcalloc argument order 2013-01-27 22:46:33 -05:00
icmp.h icmp.h: Remove extern from function prototypes 2013-09-20 14:49:33 -04:00
ieee80211_radiotap.h mac80211: add radiotap flag and handling for 5/10 MHz 2013-07-16 09:58:05 +03:00
ieee802154_netdev.h ieee802154/nl-mac.c: make some MLME operations optional 2013-04-08 12:00:16 -04:00
ieee802154.h 6LoWPAN: add fragmentation support 2011-11-14 00:19:42 -05:00
if_inet6.h ipv6 addrconf: extend ifa_flags to u32 2013-12-06 16:34:43 -05:00
inet6_connection_sock.h inet*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
inet6_hashtables.h ipv6: split inet6_ehashfn to hash functions per compilation unit 2013-10-19 19:45:34 -04:00
inet_common.h inet*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
inet_connection_sock.h inet*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
inet_ecn.h net: Correct comparisons and calculations using skb->tail and skb-transport_header 2013-05-28 23:49:07 -07:00
inet_frag.h inet: remove old fragmentation hash initializing 2013-10-23 17:01:41 -04:00
inet_hashtables.h tcp/dccp: remove twchain 2013-10-08 23:19:24 -04:00
inet_sock.h inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once 2013-10-19 19:45:35 -04:00
inet_timewait_sock.h netdev: inet_timewait_sock.h missing semi-colon when KMEMCHECK is enabled 2013-10-17 15:56:53 -04:00
inetpeer.h ipv4: remove unused function 2013-12-28 17:03:20 -05:00
ip6_checksum.h net: fix build errors if ipv6 is disabled 2013-10-09 13:04:03 -04:00
ip6_fib.h ipv6: remove prune parameter for fib6_clean_all 2014-01-02 03:30:35 -05:00
ip6_route.h IPv6: add the option to use anycast addresses as source addresses in echo reply 2014-01-07 15:51:39 -05:00
ip6_tunnel.h net: unify the pcpu_tstats and br_cpu_netstats as one 2014-01-04 20:10:24 -05:00
ip_fib.h ip*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
ip_tunnels.h net: unify the pcpu_tstats and br_cpu_netstats as one 2014-01-04 20:10:24 -05:00
ip_vs.h netfilter: push reasm skb through instead of original frag skbs 2013-11-11 00:19:35 -05:00
ip.h ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing 2014-01-13 11:22:54 -08:00
ipcomp.h
ipconfig.h
ipv6.h ipv6: namespace cleanups 2014-01-01 23:46:09 -05:00
ipx.h ipx.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
iw_handler.h iw_handler.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
lapb.h lapb.h: Remove extern from function prototypes 2013-09-21 14:01:38 -04:00
lib80211.h hostap: Don't use create_proc_read_entry() 2013-04-29 15:41:56 -04:00
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_conn.h llc*.h: Remove extern from function prototypes 2013-09-21 14:01:38 -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_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 mac80211: add helper functions for tracking P2P NoA state 2013-12-19 13:37:46 +01:00
mac802154.h mac802154: correct a typo in ieee802154_alloc_device() prototype 2013-10-21 18:56:23 -04:00
mip6.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
mld.h net: ipv6: mld: get rid of MLDV2_MRC and simplify calculation 2013-09-04 14:53:20 -04:00
mrp.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-01 17:06:14 -04:00
ndisc.h ndisc.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
neighbour.h ipv6: router reachability probing 2013-12-11 16:02:58 -05:00
net_namespace.h netfilter: nf_tables: complete net namespace support 2013-10-14 18:00:59 +02:00
net_ratelimit.h
netdma.h
netevent.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netlabel.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
netlink.h netevent/netlink.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
netprio_cgroup.h net: netprio: rename config to be more consistent with cgroup configs 2014-01-03 23:41:42 +01:00
netrom.h netrom.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
nexthop.h
nl802154.h
p8022.h p8022.h: Remove extern from function prototypes 2013-09-21 14:01:39 -04:00
ping.h ipv4: ping make local stuff static 2013-12-28 17:05:45 -05:00
pkt_cls.h net_sched: cls: refactor out struct tcf_ext_map 2013-12-18 12:52:07 -05:00
pkt_sched.h pkt_sched: give visibility to mq slave qdiscs 2013-12-09 19:54:47 -05:00
protocol.h protocol.h: Remove extern from function prototypes 2013-09-23 01:51:08 -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 net_sched: red: Make minor corrections to comments 2012-04-16 23:53:11 -04:00
regulatory.h cfg80211: use enum nl80211_dfs_regions for dfs_region everywhere 2013-11-25 20:52:12 +01:00
request_sock.h inet: includes a sock_common in request_sock 2013-10-10 00:08:07 -04:00
rose.h rose.h: Remove extern from function prototypes 2013-09-23 01:51:08 -04:00
route.h ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing 2014-01-13 11:22:54 -08:00
rtnetlink.h netlink: cleanup rntl_af_register 2014-01-01 23:42:19 -05:00
sch_generic.h net_sched: convert tcf_proto_ops to use struct list_head 2013-12-18 12:52:08 -05:00
scm.h scm.h: Remove extern from function prototypes 2013-09-23 01:51:09 -04:00
secure_seq.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-01 17:06:14 -04:00
slhc_vj.h
snmp.h net: avoid reloads in SNMP_UPD_PO_STATS 2012-08-06 13:40:47 -07:00
sock.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2014-01-05 20:18:50 -05:00
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
tcp_memcontrol.h tcp_memcontrol: Kill struct tcp_memcontrol 2013-10-21 18:43:02 -04:00
tcp_states.h
tcp.h tcp: make local functions static 2013-12-29 16:34:24 -05:00
timewait_sock.h [PATCH] tcp: Cache inetpeer in timewait socket, and only when necessary. 2012-06-09 14:56:12 -07:00
transp_v6.h transp_v6.h: style neatening 2013-06-04 16:43:42 -07:00
udp.h udp: Remove unnecessary semicolon from do{}while (0) macro 2013-11-07 02:14:33 -05:00
udplite.h udplite.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
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 vxlan: Have the NIC drivers do less work for offloads 2013-10-29 02:39:13 -07:00
wext.h wext.h: Remove extern from function prototypes 2013-09-23 16:29:40 -04:00
wimax.h wimax.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
wpan-phy.h mac802154: monitor device support 2012-05-16 15:17:08 -04:00
x25.h x25.h: Remove extern from function prototypes 2013-09-23 16:29:41 -04:00
x25device.h
xfrm.h xfrm: export verify_userspi_info for pkfey and netlink interface 2013-12-16 12:54:02 +01:00