summaryrefslogtreecommitdiff
path: root/net
AgeCommit message (Collapse)Author
2010-10-21Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6
2010-10-21Merge branch 'for-patrick' of ↵Patrick McHardy
git://git.kernel.org/pub/scm/linux/kernel/git/horms/lvs-test-2.6
2010-10-21tproxy: use the interface primary IP address as a default value for --on-ipBalazs Scheidler
The REDIRECT target and the older TProxy versions used the primary address of the incoming interface as the default value of the --on-ip parameter. This was unintentionally changed during the initial TProxy submission and caused confusion among users. Since IPv6 has no notion of primary address, we just select the first address on the list: this way the socket lookup finds wildcard bound sockets properly and we cannot really do better without the user telling us the IPv6 address of the proxy. This is implemented for both IPv4 and IPv6. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: added IPv6 support to the socket matchBalazs Scheidler
The ICMP extraction bits were contributed by Harry Mason. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: added IPv6 support to the TPROXY targetBalazs Scheidler
This requires a new revision as the old target structure was IPv4 specific. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: allow non-local binds of IPv6 sockets if IP_TRANSPARENT is enabledBalazs Scheidler
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: added tproxy sockopt interface in the IPV6 layerBalazs Scheidler
Support for IPV6_RECVORIGDSTADDR sockopt for UDP sockets were contributed by Harry Mason. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: added udp6_lib_lookup functionBalazs Scheidler
Just like with IPv4, we need access to the UDP hash table to look up local sockets, but instead of exporting the global udp_table, export a lookup function. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: added const specifiers to udp lookup functionsBalazs Scheidler
The parameters for various UDP lookup functions were non-const, even though they could be const. TProxy has some const references and instead of downcasting it, I added const specifiers along the path. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: split off ipv6 defragmentation to a separate moduleBalazs Scheidler
Like with IPv4, TProxy needs IPv6 defragmentation but does not require connection tracking. Since defragmentation was coupled with conntrack, I split off the two, creating an nf_defrag_ipv6 module, similar to the already existing nf_defrag_ipv4. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21l2tp: small cleanupEric Dumazet
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21nf_nat: restrict ICMP translation for embedded headerJulian Anastasov
Skip ICMP translation of embedded protocol header if NAT bits are not set. Needed for IPVS to see the original embedded addresses because for IPVS traffic the IPS_SRC_NAT_BIT and IPS_DST_NAT_BIT bits are not set. It happens when IPVS performs DNAT for client packets after using nf_conntrack_alter_reply to expect replies from real server. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21can-raw: add msg_flags to distinguish local trafficOliver Hartkopp
CAN has no addressing scheme. It is currently impossible for userspace to tell is a received CAN frame comes from another process on the local host, or from a remote CAN device. This patch add support for userspace applications to distinguish between 'own', 'local' and 'remote' CAN traffic. The distinction is made by returning flags in msg->msg_flags in the call to recvmsg(). The added documentation explains the introduced flags. Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-219p: client code cleanupstephen hemminger
Make p9_client_version static since only used in one file. Remove p9_client_auth because it is defined but never used. Compile tested only. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21rds: make local functions/variables staticstephen hemminger
The RDS protocol has lots of functions that should be declared static. rds_message_get/add_version_extension is removed since it defined but never used. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21napi: unexport napi_reuse_skbstephen hemminger
The function napi_reuse_skb is only used inside core. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21tipc: delete needless memset from bearer enabling.Allan Stephens
Eliminates zeroing out of the new bearer structure at the start of activation, since it is already in that state. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21bridge: Forward reserved group addresses if !STPBenjamin Poirier
Make all frames sent to reserved group MAC addresses (01:80:c2:00:00:00 to 01:80:c2:00:00:0f) be forwarded if STP is disabled. This enables forwarding EAPOL frames, among other things. Signed-off-by: Benjamin Poirier <benjamin.poirier@polymtl.ca> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21net/neighbour: cancel_delayed_work() + flush_scheduled_work() -> ↵Tejun Heo
cancel_delayed_work_sync() flush_scheduled_work() is going away. Prepare for it. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21tproxy: fix hash locking issue when using port redirection in ↵Balazs Scheidler
__inet_inherit_port() When __inet_inherit_port() is called on a tproxy connection the wrong locks are held for the inet_bind_bucket it is added to. __inet_inherit_port() made an implicit assumption that the listener's port number (and thus its bind bucket). Unfortunately, if you're using the TPROXY target to redirect skbs to a transparent proxy that assumption is not true anymore and things break. This patch adds code to __inet_inherit_port() so that it can handle this case by looking up or creating a new bind bucket for the child socket and updates callers of __inet_inherit_port() to gracefully handle __inet_inherit_port() failing. Reported by and original patch from Stephen Buck <stephen.buck@exinda.com>. See http://marc.info/?t=128169268200001&r=1&w=2 for the original discussion. Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: add lookup type checks for UDP in nf_tproxy_get_sock_v4()Balazs Scheidler
Also, inline this function as the lookup_type is always a literal and inlining removes branches performed at runtime. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21tproxy: kick out TIME_WAIT sockets in case a new connection comes in with ↵Balazs Scheidler
the same tuple Without tproxy redirections an incoming SYN kicks out conflicting TIME_WAIT sockets, in order to handle clients that reuse ports within the TIME_WAIT period. The same mechanism didn't work in case TProxy is involved in finding the proper socket, as the time_wait processing code looked up the listening socket assuming that the listener addr/port matches those of the established connection. This is not the case with TProxy as the listener addr/port is possibly changed with the tproxy rule. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: KOVACS Krisztian <hidden@balabit.hu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-10-21net_sched: remove the unused parameter of qdisc_create_dflt()Changli Gao
The first parameter dev isn't in use in qdisc_create_dflt(). Signed-off-by: Changli Gao <xiaosuo@gmail.com> Acked-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21xfrm: make xfrm_bundle_ok localstephen hemminger
Only used in one place. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21rtnetlink: remove rtnl_kill_linksstephen hemminger
The function rtnl_kill_links is defined but never used. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21xfrm6: make xfrm6_tunnel_free_spi localstephen hemminger
Function only defined and used in one file. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21bridge: make br_parse_ip_options staticstephen hemminger
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21socket: localize functionsstephen hemminger
A couple of functions in socket.c are only used there and should be localized. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21fib: introduce fib_alias_accessed() helperEric Dumazet
Perf tools session at NFWS 2010 pointed out a false sharing on struct fib_alias that can be avoided pretty easily, if we set FA_S_ACCESSED bit only if needed (ie : not already set) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21net/sched: fix missing spinlock initEric Dumazet
Under network load, doing : tc qdisc del dev eth0 root triggers : [ 167.193087] BUG: spinlock bad magic on CPU#3, udpflood/4928 [ 167.193139] lock: c15bc324, .magic: 00000000, .owner: <none>/-1, .owner_cpu: -1 [ 167.193193] Pid: 4928, comm: udpflood Not tainted 2.6.36-rc7-11417-g215340c-dirty #323 [ 167.193245] Call Trace: [ 167.193292] [<c13abaa0>] ? printk+0x18/0x20 [ 167.193342] [<c11afb53>] spin_bug+0xa3/0xf0 [ 167.193389] [<c11afcdd>] do_raw_spin_lock+0x7d/0x160 [ 167.193440] [<c1313d4e>] ? __dev_xmit_skb+0x27e/0x2b0 [ 167.193496] [<c107382b>] ? trace_hardirqs_on+0xb/0x10 [ 167.193545] [<c13ae99a>] _raw_spin_lock+0x3a/0x40 [ 167.193593] [<c1313d4e>] ? __dev_xmit_skb+0x27e/0x2b0 [ 167.193641] [<c1313d4e>] __dev_xmit_skb+0x27e/0x2b0 commit 79640a4ca695 (add additional lock to qdisc to increase throughput) forgot to initialize noop_qdisc and noqueue_qdisc busylock Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21ipvs: provide address family for debuggingJulian Anastasov
As skb->protocol is not valid in LOCAL_OUT add parameter for address family in packet debugging functions. Even if ports are not present in AH and ESP change them to use ip_vs_tcpudp_debug_packet to show at least valid addresses as before. This patch removes the last user of skb->protocol in IPVS. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: inherit forwarding method in backupJulian Anastasov
Connections in backup server should inherit the forwarding method from real server. It is a way to fix a problem where the forwarding method in backup connection is damaged by logical OR operation with the real server's connection flags. And the change is needed for setups where the backup server uses different forwarding method for the same real servers. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: changes for local clientJulian Anastasov
This patch deals with local client processing. Prefer LOCAL_OUT hook for scheduling connections from local clients. LOCAL_IN is still supported if the packets are not marked as processed in LOCAL_OUT. The idea to process requests in LOCAL_OUT is to alter conntrack reply before it is confirmed at POST_ROUTING. If the local requests are processed in LOCAL_IN the conntrack can not be updated and matching by state is impossible. Add the following handlers: - ip_vs_reply[46] at LOCAL_IN:99 to process replies from remote real servers to local clients. Now when both replies from remote real servers (ip_vs_reply*) and local real servers (ip_vs_local_reply*) are handled it is safe to remove the conn_out_get call from ip_vs_in because it does not support related ICMP packets. - ip_vs_local_request[46] at LOCAL_OUT:-98 to process requests from local client Handling in LOCAL_OUT causes some changes: - as skb->dev, skb->protocol and skb->pkt_type are not defined in LOCAL_OUT make sure we set skb->dev before calling icmpv6_send, prefer skb_dst(skb) for struct net and remove the skb->protocol checks from TUN transmitters. [ horms@verge.net.au: removed trailing whitespace ] Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: changes for local real serverJulian Anastasov
This patch deals with local real servers: - Add support for DNAT to local address (different real server port). It needs ip_vs_out hook in LOCAL_OUT for both families because skb->protocol is not set for locally generated packets and can not be used to set 'af'. - Skip packets in ip_vs_in marked with skb->ipvs_property because ip_vs_out processing can be executed in LOCAL_OUT but we still have the conn_out_get check in ip_vs_in. - Ignore packets with inet->nodefrag from local stack - Require skb_dst(skb) != NULL because we use it to get struct net - Add support for changing the route to local IPv4 stack after DNAT depending on the source address type. Local client sets output route and the remote client sets input route. It looks like IPv6 does not need such rerouting because the replies use addresses from initial incoming header, not from skb route. - All transmitters now have strict checks for the destination address type: redirect from non-local address to local real server requires NAT method, local address can not be used as source address when talking to remote real server. - Now LOCALNODE is not set explicitly as forwarding method in real server to allow the connections to provide correct forwarding method to the backup server. Not sure if this breaks tools that expect to see 'Local' real server type. If needed, this can be supported with new flag IP_VS_DEST_F_LOCAL. Now it should be possible connections in backup that lost their fwmark information during sync to be forwarded properly to their daddr, even if it is local address in the backup server. By this way backup could be used as real server for DR or TUN, for NAT there are some restrictions because tuple collisions in conntracks can create problems for the traffic. - Call ip_vs_dst_reset when destination is updated in case some real server IP type is changed between local and remote. [ horms@verge.net.au: removed trailing whitespace ] Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: move ip_route_me_harder for ICMPJulian Anastasov
Currently, ip_route_me_harder after ip_vs_out_icmp is called even if packet is not related to IPVS connection. Move it into handle_response_icmp. Also, force rerouting if sending to local client because IPv4 stack uses addresses from the route. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: create ip_vs_defrag_userJulian Anastasov
Create new function ip_vs_defrag_user to return correct IP_DEFRAG_xxx user depending on the hooknum. It will be needed when we add handlers in LOCAL_OUT. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: fix CHECKSUM_PARTIAL for TUN methodJulian Anastasov
The recent change in IP_VS_XMIT_TUNNEL to set CHECKSUM_NONE is not correct. After adding IPIP header skb->csum becomes invalid but the CHECKSUM_PARTIAL case must be supported. So, use skb_forward_csum() which is most suitable for us to allow local clients to send IPIP to remote real server. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: stop ICMP from FORWARD to localJulian Anastasov
Delivering locally ICMP from FORWARD hook is not supported. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: do not schedule conns from real serversJulian Anastasov
This patch is needed to avoid scheduling of packets from local real server when we add ip_vs_in in LOCAL_OUT hook to support local client. Currently, when ip_vs_in can not find existing connection it tries to create new one by calling ip_vs_schedule. The default indication from ip_vs_schedule was if connection was scheduled to real server. If real server is not available we try to use the bypass forwarding method or to send ICMP error. But in some cases we do not want to use the bypass feature. So, add flag 'ignored' to indicate if the scheduler ignores this packet. Make sure we do not create new connections from replies. We can hit this problem for persistent services and local real server when ip_vs_in is added to LOCAL_OUT hook to handle local clients. Also, make sure ip_vs_schedule ignores SYN packets for Active FTP DATA from local real server. The FTP DATA connection should be created on SYN+ACK from client to assign correct connection daddr. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: switch to notrack modeJulian Anastasov
Change skb->ipvs_property semantic. This is preparation to support ip_vs_out processing in LOCAL_OUT. ipvs_property=1 will be used to avoid expensive lookups for traffic sent by transmitters. Now when conntrack support is not used we call ip_vs_notrack method to avoid problems in OUTPUT and POST_ROUTING hooks instead of exiting POST_ROUTING as before. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: optimize checksums for appsJulian Anastasov
Avoid full checksum calculation for apps that can provide info whether csum was broken after payload mangling. For now only ip_vs_ftp mangles payload and it updates the csum, so the full recalculation is avoided for all packets. Add CHECKSUM_UNNECESSARY for snat_handler (TCP and UDP). It is needed to support SNAT from local address for the case when csum is fully recalculated. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21ipvs: fix CHECKSUM_PARTIAL for TCP, UDPJulian Anastasov
Fix CHECKSUM_PARTIAL handling. Tested for IPv4 TCP, UDP not tested because it needs network card with HW CSUM support. May be fixes problem where IPVS can not be used in virtual boxes. Problem appears with DNAT to local address when the local stack sends reply in CHECKSUM_PARTIAL mode. Fix tcp_dnat_handler and udp_dnat_handler to provide vaddr and daddr in right order (old and new IP) when calling tcp_partial_csum_update/udp_partial_csum_update (CHECKSUM_PARTIAL). Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au>
2010-10-21bridge: Add support for TX vlan offload.Jesse Gross
If some of the underlying devices support it, enable vlan offload on transmit for bridge devices. This allows senders to take advantage of the hardware support, similar to other forms of acceleration. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21ethtool: Add support for vlan accleration.Jesse Gross
Now that vlan acceleration is handled consistently regardless of usage, it is possible to enable and disable it at will. This adds support for Ethtool operations that change the offloading status for debugging purposes, similar to other forms of hardware acceleration. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21vlan: Centralize handling of hardware acceleration.Jesse Gross
Currently each driver that is capable of vlan hardware acceleration must be aware of the vlan groups that are configured and then pass the stripped tag to a specialized receive function. This is different from other types of hardware offload in that it places a significant amount of knowledge in the driver itself rather keeping it in the networking core. This makes vlan offloading function more similarly to other forms of offloading (such as checksum offloading or TSO) by doing the following: * On receive, stripped vlans are passed directly to the network core, without attempting to check for vlan groups or reconstructing the header if no group * vlans are made less special by folding the logic into the main receive routines * On transmit, the device layer will add the vlan header in software if the hardware doesn't support it, instead of spreading that logic out in upper layers, such as bonding. There are a number of advantages to this: * Fixes all bugs with drivers incorrectly dropping vlan headers at once. * Avoids having to disable VLAN acceleration when in promiscuous mode (good for bridging since it always puts devices in promiscuous mode). * Keeps VLAN tag separate until given to ultimate consumer, which avoids needing to do header reconstruction as in tg3 unless absolutely necessary. * Consolidates common code in core networking. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21vlan: Avoid hash table lookup to find group.Jesse Gross
A struct net_device always maps to zero or one vlan groups and we always know the device when we are looking up a group. We currently do a hash table lookup on the device to find the group but it is much simpler to just store a pointer. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21vlan: Enable software emulation for vlan accleration.Jesse Gross
Currently users of hardware vlan accleration need to know whether the device supports it before generating packets. However, vlan acceleration will soon be available in a more flexible manner so knowing ahead of time becomes much more difficult. This adds a software fallback path for vlan packets on devices without the necessary offloading support, similar to other types of hardware accleration. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21vlan: Rename VLAN_GROUP_ARRAY_LEN to VLAN_N_VID.Jesse Gross
VLAN_GROUP_ARRAY_LEN is simply the number of possible vlan VIDs. Since vlan groups will soon be more of an implementation detail for vlan devices, rename the constant to be descriptive of its actual purpose. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-21ebtables: Allow filtering of hardware accelerated vlan frames.Jesse Gross
An upcoming commit will allow packets with hardware vlan acceleration information to be passed though more parts of the network stack, including packets trunked through the bridge. This adds support for matching and filtering those packets through ebtables. Signed-off-by: Jesse Gross <jesse@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-20net: avoid RCU for NOCACHE dstEric Dumazet
There is no point using RCU for dst we allocate for a very short time (used once). Change dst_release() to take DST_NOCACHE into account, but also change skb_dst_set_noref() to force a refcount increment for such dst. This is a _huge_ gain, because we dont waste memory to store xx thousand of dsts. Instead of queueing them to RCU, we can free them instantly. CPU caches can stay hot, re-using same memory blocks to hold temporary dsts. Note : remove unneeded smp_mb__before_atomic_dec(); in dst_release(), since atomic_dec_return() implies a full memory barrier. Stress test, 160.000.000 udp frames sent, IP route cache disabled (DDOS). Before: real 0m38.091s user 0m13.189s sys 7m53.018s After: real 0m29.946s user 0m12.157s sys 7m40.605s For reference, if IP route cache was enabled : real 0m32.030s user 0m10.521s sys 8m15.243s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>