linux/net/ipv4
Eric Dumazet 9088c56095 udp: Improve port randomization
Current UDP port allocation is suboptimal.
We select the shortest chain to chose a port (out of 512)
that will hash in this shortest chain.

First, it can lead to give not so ramdom ports and ease
give attackers more opportunities to break the system.

Second, it can consume a lot of CPU to scan all table
in order to find the shortest chain.

Third, in some pathological cases we can fail to find
a free port even if they are plenty of them.

This patch zap the search for a short chain and only
use one random seed. Problem of getting long chains
should be addressed in another way, since we can
obtain long chains with non random ports.

Based on a report and patch from Vitaly Mayatskikh

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:44:17 -07:00
..
ipvs net: Use hton[sl]() instead of __constant_hton[sl]() where applicable 2008-09-20 22:20:49 -07:00
netfilter netfilter: xtables: provide invoked family value to extensions 2008-10-08 11:35:20 +02:00
af_inet.c ipv4: Allow binding to non-local addresses if IP_TRANSPARENT is set 2008-10-01 07:31:24 -07:00
ah4.c [IPSEC]: Fix bogus usage of u64 on input sequence number 2008-02-12 22:50:35 -08:00
arp.c mib: add net to NET_INC_STATS_BH 2008-07-16 20:31:16 -07:00
cipso_ipv4.c cipso: Relax too much careful cipso hash function. 2008-05-13 23:23:55 -07:00
datagram.c mib: add net to IP_INC_STATS_BH 2008-07-16 20:20:11 -07:00
devinet.c ipv: Re-enable IP when MTU > 68 2008-09-02 17:28:58 -07:00
esp4.c ipsec: Interfamily IPSec BEET 2008-08-06 02:39:30 -07:00
fib_frontend.c netns: add namespace parameter to rt_cache_flush 2008-07-05 19:00:44 -07:00
fib_hash.c netns: add namespace parameter to rt_cache_flush 2008-07-05 19:00:44 -07:00
fib_lookup.h [IPV4] FIB_HASH: Reduce memory needs and speedup lookups 2008-01-28 15:02:46 -08:00
fib_rules.c net: add fib_rules_ops to flush_cache method 2008-07-05 19:01:28 -07:00
fib_semantics.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-06-13 20:52:39 -07:00
fib_trie.c proc: consolidate per-net single-release callers 2008-07-18 04:07:44 -07:00
icmp.c icmp: icmp_sk() should not use smp_processor_id() in preemptible code 2008-08-23 04:43:33 -07:00
igmp.c ipv4: add mc_count to in_device. 2008-10-07 15:34:37 -07:00
inet_connection_sock.c tcp: Port redirection support for TCP 2008-10-01 07:46:49 -07:00
inet_diag.c inet_diag: Add empty bucket optimization to inet_diag too 2008-08-28 01:09:54 -07:00
inet_fragment.c net: convert BUG_TRAP to generic WARN_ON 2008-07-25 21:43:18 -07:00
inet_hashtables.c net: convert BUG_TRAP to generic WARN_ON 2008-07-25 21:43:18 -07:00
inet_lro.c net/inet_lro: remove setting skb->ip_summed when not LRO-able 2008-06-27 20:09:00 -07:00
inet_timewait_sock.c ipv4: Implement IP_TRANSPARENT socket option 2008-10-01 07:30:02 -07:00
inetpeer.c net: remove CVS keywords 2008-06-11 21:00:38 -07:00
ip_forward.c mib: add net to IP_INC_STATS_BH 2008-07-16 20:20:11 -07:00
ip_fragment.c net: convert BUG_TRAP to generic WARN_ON 2008-07-25 21:43:18 -07:00
ip_gre.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2008-05-25 23:26:10 -07:00
ip_input.c mib: put ip statistics on struct net 2008-07-18 04:02:42 -07:00
ip_options.c net: remove CVS keywords 2008-06-11 21:00:38 -07:00
ip_output.c ipv4: Make Netfilter's ip_route_me_harder() non-local address compatible 2008-10-01 07:44:42 -07:00
ip_sockglue.c ipv4: Implement IP_TRANSPARENT socket option 2008-10-01 07:30:02 -07:00
ipcomp.c ipcomp: Fix warnings after ipcomp consolidation. 2008-07-27 03:59:24 -07:00
ipconfig.c netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
ipip.c net: remove CVS keywords 2008-06-11 21:00:38 -07:00
ipmr.c netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
Kconfig ipsec: ipcomp - Merge IPComp implementations 2008-07-25 02:54:40 -07:00
Makefile [UDP]: Revert udplite and code split. 2008-03-06 16:22:02 -08:00
netfilter.c netfilter: netns: fix {ip,6}_route_me_harder() in netns 2008-10-08 11:35:03 +02:00
proc.c tcp: MD5: Use MIB counter instead of warning for MD5 mismatch. 2008-07-30 03:27:25 -07:00
protocol.c net: remove CVS keywords 2008-06-11 21:00:38 -07:00
raw.c mib: add net to IP_INC_STATS 2008-07-16 20:19:49 -07:00
route.c ipv4: Loosen source address check on IPv4 output 2008-10-01 07:28:28 -07:00
syncookies.c tcp: Port redirection support for TCP 2008-10-01 07:46:49 -07:00
sysctl_net_ipv4.c net: Add missing extra2 parameter for ip_default_ttl sysctl 2008-08-03 14:06:44 -07:00
tcp_bic.c [TCP]: BIC web page link is corrected. 2008-02-28 22:14:32 -08:00
tcp_cong.c tcp: Limit cwnd growth when deferring for GSO 2008-04-29 03:13:52 -07:00
tcp_cubic.c rename div64_64 to div64_u64 2008-05-01 08:03:58 -07:00
tcp_diag.c net: remove CVS keywords 2008-06-11 21:00:38 -07:00
tcp_highspeed.c [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid 2008-01-28 14:55:41 -08:00
tcp_htcp.c [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid 2008-01-28 14:55:41 -08:00
tcp_hybla.c net: fix returning void-valued expression warnings 2008-05-01 02:47:38 -07:00
tcp_illinois.c [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid 2008-01-28 14:55:41 -08:00
tcp_input.c tcp: cleanup messy initializer 2008-10-07 14:43:31 -07:00
tcp_ipv4.c tcp: fix length used for checksum in a reset 2008-10-08 11:34:06 -07:00
tcp_lp.c [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid 2008-01-28 14:55:41 -08:00
tcp_minisocks.c tcp: kill pointless urg_mode 2008-10-07 14:43:06 -07:00
tcp_output.c tcp: kill pointless urg_mode 2008-10-07 14:43:06 -07:00
tcp_probe.c tcp: correct kcalloc usage 2008-07-10 16:51:32 -07:00
tcp_scalable.c [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid 2008-01-28 14:55:41 -08:00
tcp_timer.c net: wrap sk->sk_backlog_rcv() 2008-10-07 14:18:42 -07:00
tcp_vegas.c net: fix returning void-valued expression warnings 2008-05-01 02:47:38 -07:00
tcp_vegas.h [TCP]: congestion control API pass RTT in microseconds 2007-07-31 02:27:57 -07:00
tcp_veno.c net: fix returning void-valued expression warnings 2008-05-01 02:47:38 -07:00
tcp_westwood.c [TCP]: congestion control API pass RTT in microseconds 2007-07-31 02:27:57 -07:00
tcp_yeah.c [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoid 2008-01-28 14:55:41 -08:00
tcp.c tcp: kill pointless urg_mode 2008-10-07 14:43:06 -07:00
tunnel4.c [IPV4] TUNNEL4: Fix incoming packet length check for inter-protocol tunnel. 2008-06-05 04:02:33 +09:00
udp_impl.h net: change proto destroy method to return void 2008-06-14 17:04:49 -07:00
udp.c udp: Improve port randomization 2008-10-08 11:44:17 -07:00
udplite.c mib: put udplite statistics on struct net 2008-07-18 04:03:45 -07:00
xfrm4_input.c [IPSEC]: Fix transport-mode async resume on intput without netfilter 2008-01-28 15:00:10 -08:00
xfrm4_mode_beet.c ipsec: Interfamily IPSec BEET 2008-08-06 02:39:30 -07:00
xfrm4_mode_transport.c [IPSEC]: Use IPv6 calling convention as the convention for x->mode->output 2007-10-10 16:55:54 -07:00
xfrm4_mode_tunnel.c xfrm: fix fragmentation for ipv4 xfrm tunnel 2008-06-17 16:38:23 -07:00
xfrm4_output.c [IPSEC]: Fix inter address family IPsec tunnel handling. 2008-03-24 14:51:51 -07:00
xfrm4_policy.c [NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS. 2008-03-26 04:39:53 +09:00
xfrm4_state.c [IPSEC]: Fix BEET output 2008-03-26 16:51:09 -07:00
xfrm4_tunnel.c [IPCOMP]: Fix reception of incompressible packets 2008-01-31 19:27:24 -08:00