linux-uconsole/include/net
Eric Dumazet 4176df017a ip: make IP identifiers less predictable
[ Upstream commit 04ca6973f7 ]

In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.

With commit 73f156a6e8 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.

This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.

Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.

This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.

We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.

For IPv6, adds saddr into the hash as well, but not nexthdr.

If I ping the patched target, we can see ID are now hard to predict.

21:57:11.008086 IP (...)
    A > target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
    target > A: ICMP echo reply, seq 1, length 64

21:57:12.013133 IP (...)
    A > target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
    target > A: ICMP echo reply, seq 2, length 64

21:57:13.016580 IP (...)
    A > target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
    target > A: ICMP echo reply, seq 3, length 64

[1] TCP sessions uses a per flow ID generator not changed by this patch.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jeffrey Knockel <jeffk@cs.unm.edu>
Reported-by: Jedidiah R. Crandall <crandall@cs.unm.edu>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Hannes Frederic Sowa <hannes@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-08-14 09:24:15 +08:00
..
9p 9p: turn fid->dlist into hlist 2013-02-27 22:51:08 -05:00
bluetooth Bluetooth: Introduce a new HCI_RFKILLED flag 2013-10-13 16:08:32 -07:00
caif caif: Remove my bouncing email address. 2013-04-23 13:25:51 -04:00
irda irda: small read past the end of array in debug code 2013-04-19 17:32:31 -04:00
iucv af_iucv: fix recvmsg by replacing skb_pull() function 2013-04-08 17:16:57 -04:00
netfilter netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len 2014-05-30 21:52:11 -07:00
netns netfilter: nf_log: prepare net namespace support for loggers 2013-04-05 20:12:54 +02:00
nfc NFC: RFKILL support 2013-04-12 16:54:45 +02:00
phonet net: remove my future former mail address 2012-06-17 16:29:38 -07:00
sctp net: sctp: cache auth_enable per endpoint 2014-05-30 21:52:15 -07:00
tc_act
act_api.h act_police: move struct tcf_police to act_police.c 2013-02-12 18:59:45 -05:00
addrconf.h IPv6 NAT: Do not drop DNATed 6to4/6rd packets 2013-10-13 16:08:30 -07:00
af_ieee802154.h
af_rxrpc.h
af_unix.h af_unix: fix a fatal race with bit fields 2013-05-01 15:13:49 -04:00
ah.h
arp.h net: Dont use ifindices in hash fns 2012-08-09 16:18:06 -07:00
atmclip.h atm: clip: Use device neigh support on top of "arp_tbl". 2011-11-30 18:51:03 -05:00
ax25.h hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ax88796.h
cfg80211-wext.h
cfg80211.h cfg80211: introduce critical protocol indication from user-space 2013-04-22 15:48:00 +02:00
checksum.h net: core: add function for incremental IPv6 pseudo header checksum updates 2012-08-30 03:00:16 +02:00
cipso_ipv4.h net: fix cipso packet validation when !NETLABEL 2013-11-04 04:31:04 -08:00
cls_cgroup.h cls_cgroup: remove task_struct parameter from sock_update_classid() 2013-04-09 13:19:35 -04:00
codel.h codel: refine one condition to avoid a nul rec_inv_sqrt 2012-08-10 16:52:54 -07:00
compat.h net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
datalink.h
dcbevent.h
dcbnl.h net/dcb: Add an optional max rate attribute 2012-04-05 05:08:04 -04:00
dn.h net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
dn_dev.h
dn_fib.h decnet: Parse netlink attributes on our own 2013-03-22 10:31:16 -04:00
dn_neigh.h
dn_nsp.h
dn_route.h decnet: use correct RCU API to deref sk_dst_cache field 2013-01-28 00:15:27 -05:00
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.h net: dst: provide accessor function to dst->xfrm 2013-11-04 04:31:03 -08:00
dst_ops.h net: Fix warnings in dst_ops.h 2012-07-19 10:43:03 -07:00
esp.h
ethoc.h
fib_rules.h ipv4: Elide fib_validate_source() completely when possible. 2012-06-29 01:36:36 -07:00
firewire.h firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection. 2013-03-26 12:32:13 -04:00
flow.h ipv4: Add FLOWI_FLAG_KNOWN_NH 2012-10-08 17:42:36 -04:00
flow_keys.h flow_keys: include thoff into flow_keys for later usage 2013-03-20 12:14:36 -04:00
garp.h
gen_stats.h
genetlink.h genl: Hold reference on correct module while netlink-dump. 2013-09-14 06:54:55 -07:00
gre.h GRE: Refactor GRE tunneling code. 2013-03-26 12:27:18 -04:00
gro_cells.h gro: Fix kcalloc argument order 2013-01-27 22:46:33 -05:00
icmp.h ipv4: fix error handling in icmp_protocol. 2013-02-22 15:10:18 -05:00
ieee80211_radiotap.h mac80211: support (partial) VHT radiotap information 2012-11-27 11:56:18 +01:00
ieee802154.h
ieee802154_netdev.h ieee802154/nl-mac.c: make some MLME operations optional 2013-04-08 12:00:16 -04:00
if_inet6.h net: ipv6: only invalidate previously tokenized addresses 2013-04-09 13:12:23 -04:00
inet6_connection_sock.h ipv6: Add helper inet6_csk_update_pmtu(). 2012-07-16 03:44:56 -07:00
inet6_hashtables.h ipv6: use a stronger hash for tcp 2013-02-21 18:15:58 -05:00
inet_common.h net-tcp: Fast Open client - sendmsg(MSG_FASTOPEN) 2012-07-19 11:02:03 -07:00
inet_connection_sock.h tcp: Tail loss probe (TLP) 2013-03-12 08:30:34 -04:00
inet_ecn.h tunnel: drop packet if ECN present with not-ECT 2012-09-27 18:12:37 -04:00
inet_frag.h net: frag, fix race conditions in LRU list maintenance 2013-05-06 11:06:51 -04:00
inet_hashtables.h hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
inet_sock.h ipv6: use a stronger hash for tcp 2013-02-21 18:15:58 -05:00
inet_timewait_sock.h hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
inetpeer.h inetpeer: get rid of ip_id_count 2014-08-14 09:24:15 +08:00
ip.h ip: make IP identifiers less predictable 2014-08-14 09:24:15 +08:00
ip6_checksum.h ipv6: move csum_ipv6_magic() and udp6_csum_init() into static library 2013-01-08 17:56:10 -08:00
ip6_fib.h ipv6: reset dst.expires value when clearing expire flag 2013-11-20 12:27:46 -08:00
ip6_route.h ipv6: Limit mtu to 65575 bytes 2014-05-30 21:52:14 -07:00
ip6_tunnel.h GRE: Refactor GRE tunneling code. 2013-03-26 12:27:18 -04:00
ip_fib.h ipv4: fix definition of FIB_TABLE_HASHSZ 2013-03-13 10:47:09 -04:00
ip_tunnels.h ip_gre: Fix WCCPv2 header parsing. 2013-11-20 12:27:46 -08:00
ip_vs.h netfilter: push reasm skb through instead of original frag skbs 2013-12-08 07:29:25 -08:00
ipcomp.h
ipconfig.h
ipv6.h inetpeer: get rid of ip_id_count 2014-08-14 09:24:15 +08:00
ipx.h
iw_handler.h
lapb.h lapb: Neaten debugging 2012-05-17 18:45:20 -04:00
lib80211.h hostap: Don't use create_proc_read_entry() 2013-04-29 15:41:56 -04:00
llc.h llc: Remove stray reference to sysctl_llc_station_ack_timeout. 2012-09-17 13:13:24 -04:00
llc_c_ac.h
llc_c_ev.h net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
llc_c_st.h
llc_conn.h
llc_if.h
llc_pdu.h net: delete all instances of special processing for token ring 2012-05-15 20:14:35 -04:00
llc_s_ac.h
llc_s_ev.h
llc_s_st.h
llc_sap.h
mac80211.h mac80211: add a flag to indicate CCK support for HT clients 2013-09-07 22:09:59 -07:00
mac802154.h mac802154: add wpan device-class support 2012-06-26 21:06:11 -07:00
mip6.h
mld.h
mrp.h net/802: Implement Multiple Registration Protocol (MRP) 2013-02-10 20:37:22 -05:00
ndisc.h ndisc: Add missing inline to ndisc_addr_option_pad 2013-08-11 18:35:26 -07:00
neighbour.h net neighbour, decnet: Ensure to align device private data on preferred alignment. 2013-02-11 00:21:44 -05:00
net_namespace.h netfilter: make /proc/net/netfilter pernet 2013-04-05 19:35:02 +02:00
net_ratelimit.h
netdma.h
netevent.h ipv6 netevent: Remove old_neigh from netevent_redirect. 2013-01-14 15:04:59 -05:00
netlabel.h userns: Convert the audit loginuid to be a kuid 2012-09-17 18:08:54 -07:00
netlink.h netlink: Rename pid to portid to avoid confusion 2012-09-10 15:30:41 -04:00
netprio_cgroup.h netprio_cgroup: remove task_struct parameter from sock_update_netprio() 2013-04-09 13:19:37 -04:00
netrom.h hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
nexthop.h
nl802154.h
p8022.h
ping.h
pkt_cls.h pkt_sched: namespace aware act_mirred 2013-01-14 15:09:36 -05:00
pkt_sched.h sch_api: introduce qdisc_watchdog_schedule_ns() 2013-02-12 18:59:45 -05:00
protocol.h net: Remove code duplication between offload structures 2012-11-15 17:39:51 -05:00
psnap.h
raw.h
rawv6.h ipv6: bool/const conversions phase2 2012-05-19 01:08:16 -04:00
red.h net_sched: red: Make minor corrections to comments 2012-04-16 23:53:11 -04:00
regulatory.h regulatory: use RCU to protect last_request 2013-01-03 13:01:30 +01:00
request_sock.h net: remove a stale comment for dl_next 2013-04-22 15:55:48 -04:00
rose.h
route.h ipv4: avoid a test in ip_rt_put() 2012-11-03 14:59:04 -04:00
rtnetlink.h rtnetlink: Remove passing of attributes into rtnl_doit functions 2013-03-22 10:31:16 -04:00
sch_generic.h net_sched: restore "linklayer atm" handling 2013-09-14 06:54:55 -07:00
scm.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-04-22 20:32:51 -04:00
secure_seq.h inetpeer: get rid of ip_id_count 2014-08-14 09:24:15 +08:00
slhc_vj.h
snmp.h net: avoid reloads in SNMP_UPD_PO_STATS 2012-08-06 13:40:47 -07:00
sock.h net: fix sparse warning in sk_dst_set() 2014-07-28 08:00:04 -07:00
stp.h
tcp.h net-tcp: fastopen: fix high order allocations 2014-03-23 21:38:10 -07:00
tcp_memcontrol.h cgroup: pass struct mem_cgroup instead of struct cgroup to socket memcg 2012-04-10 10:04:07 -07:00
tcp_states.h
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 ipv6: rename datagram_send_ctl and datagram_recv_ctl 2013-01-31 13:53:08 -05:00
udp.h ipv6: call udp_push_pending_frames when uncorking a socket with AF_INET pending data 2013-07-28 16:29:49 -07:00
udplite.h net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00
wext.h
wimax.h net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
wpan-phy.h mac802154: monitor device support 2012-05-16 15:17:08 -04:00
x25.h net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
x25device.h
xfrm.h xfrm: force a garbage collection after deleting a policy 2013-05-31 17:30:07 -07:00