linux/net/ipv4
Tom Herbert 4465b46900 ipv4: Allow configuring subnets as local addresses
This patch allows a host to be configured to respond to any address in
a specified range as if it were local, without actually needing to
configure the address on an interface.  This is done through routing
table configuration.  For instance, to configure a host to respond
to any address in 10.1/16 received on eth0 as a local address we can do:

ip rule add from all iif eth0 lookup 200
ip route add local 10.1/16 dev lo proto kernel scope host src 127.0.0.1 table 200

This host is now reachable by any 10.1/16 address (route lookup on
input for packets received on eth0 can find the route).  On output, the
rule will not be matched so that this host can still send packets to
10.1/16 (not sent on loopback).  Presumably, external routing can be
configured to make sense out of this.

To make this work, we needed to modify the logic in finding the
interface which is assigned a given source address for output
(dev_ip_find).  We perform a normal fib_lookup instead of just a
lookup on the local table, and in the lookup we ignore the input
interface for matching.

This patch is useful to implement IP-anycast for subnets of virtual
addresses.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-28 23:38:15 -07:00
..
netfilter Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
af_inet.c net: build_ehash_secret() and rt_bind_peer() cleanups 2010-08-20 00:50:16 -07:00
ah4.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
arp.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
cipso_ipv4.c net: Remove unnecessary returns from void function()s 2010-05-17 23:23:14 -07:00
datagram.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
devinet.c ipv4: ip_ptr cleanups 2010-09-15 22:06:05 -07:00
esp4.c xfrm: SA lookups signature with mark 2010-02-22 16:20:22 -08:00
fib_frontend.c ipv4: Allow configuring subnets as local addresses 2010-09-28 23:38:15 -07:00
fib_hash.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fib_lookup.h ipv4: cleanup - remove two unused parameters from fib_semantic_match(). 2009-05-18 15:16:37 -07:00
fib_rules.c net: rtnetlink: decouple rtnetlink address families from real address families 2010-04-26 16:13:54 +02:00
fib_semantics.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fib_trie.c fib: cleanups 2010-09-10 12:32:02 -07:00
gre.c PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol) 2010-08-21 23:05:39 -07:00
icmp.c net: simplify flags for tx timestamping 2010-08-19 00:08:30 -07:00
igmp.c ipv4: force_igmp_version ignored when a IGMPv3 query received 2010-09-13 12:56:51 -07:00
inet_connection_sock.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_diag.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
inet_fragment.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_hashtables.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_lro.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
inet_timewait_sock.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
inetpeer.c inetpeer: restore small inet_peer structures 2010-06-16 11:55:39 -07:00
ip_forward.c net-next: remove useless union keyword 2010-06-10 23:31:35 -07:00
ip_fragment.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
ip_gre.c ip_gre: percpu stats accounting 2010-09-27 21:30:43 -07:00
ip_input.c net: use this_cpu_ptr() 2010-06-28 23:24:29 -07:00
ip_options.c bridge : Sanitize skb before it enters the IP stack 2010-09-19 12:42:34 -07:00
ip_output.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
ip_sockglue.c ipv4: enable getsockopt() for IP_NODEFRAG 2010-09-13 19:57:23 -07:00
ipcomp.c xfrm: SA lookups signature with mark 2010-02-22 16:20:22 -08:00
ipconfig.c ipconfig: send host-name in DHCP requests 2010-06-02 07:05:03 -07:00
ipip.c ipip: percpu stats accounting 2010-09-27 21:30:43 -07:00
ipmr.c ipv4: ip_ptr cleanups 2010-09-15 22:06:05 -07:00
Kconfig Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-09 22:27:33 -07:00
Makefile PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol) 2010-08-21 23:05:39 -07:00
netfilter.c Merge branch 'master' of /repos/git/net-next-2.6 2010-06-15 17:31:06 +02:00
proc.c snmp: 64bit ipstats_mib for all arches 2010-06-30 13:31:19 -07:00
protocol.c net: inet_add_protocol() can use cmpxchg() 2010-09-08 21:31:35 -07:00
raw.c net: simplify flags for tx timestamping 2010-08-19 00:08:30 -07:00
route.c net: fix rcu use in ip_route_output_slow 2010-09-26 19:04:07 -07:00
syncookies.c syncookies: add support for ECN 2010-06-26 22:00:03 -07:00
sysctl_net_ipv4.c net: reserve ports for applications using fixed port numbers 2010-05-15 23:28:40 -07:00
tcp.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
tcp_bic.c
tcp_cong.c net/ipv4: Eliminate kstrdup memory leak 2010-08-27 19:31:56 -07:00
tcp_cubic.c
tcp_diag.c tcp: diag: Dont report negative values for rx queue 2009-12-03 16:06:13 -08:00
tcp_highspeed.c
tcp_htcp.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp_hybla.c TCP: tcp_hybla: Fix integer overflow in slow start increment 2010-06-02 07:15:48 -07:00
tcp_illinois.c
tcp_input.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
tcp_ipv4.c gro: unexport tcp4_gro_receive and tcp4_gro_complete 2010-08-31 13:37:07 -07:00
tcp_lp.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp_minisocks.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
tcp_output.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
tcp_probe.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
tcp_scalable.c
tcp_timer.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-09 22:27:33 -07:00
tcp_vegas.c tcp: tcp_vegas ssthresh bugfix 2009-05-25 22:44:59 -07:00
tcp_vegas.h
tcp_veno.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tcp_westwood.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
tcp_yeah.c net/ipv4: Move && and || to end of previous line 2009-11-23 10:41:23 -08:00
tunnel4.c tunnels: missing rcu_assign_pointer() 2010-09-09 15:02:39 -07:00
udp.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-09 22:27:33 -07:00
udp_impl.h net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
udplite.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
xfrm4_input.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
xfrm4_output.c netfilter: ipv4: use NFPROTO values for NF_HOOK invocation 2010-03-25 16:00:30 +01:00
xfrm4_policy.c xfrm4: strip ECN bits from tos field 2010-09-22 20:25:48 -07:00
xfrm4_state.c xfrm: Allow different selector family in temporary state 2010-09-20 11:11:38 -07:00
xfrm4_tunnel.c net: struct xfrm_tunnel in read_mostly section 2010-08-30 13:50:45 -07:00