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path: root/include/net/dst.h
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2012-07-11net: Kill set_dst_metric_rtt().David S. Miller1-6/+0
No longer used. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05net: Kill dst->_neighbour, accessors, and final uses.David S. Miller1-16/+1
No longer used. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05net: Add optional SKB arg to dst_ops->neigh_lookup().David S. Miller1-1/+7
Causes the handler to use the daddr in the ipv4/ipv6 header when the route gateway is unspecified (local subnet). Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-05net: Do delayed neigh confirmation.David S. Miller1-8/+21
When a dst_confirm() happens, mark the confirmation as pending in the dst. Then on the next packet out, when we have the neigh in-hand, do the update. This removes the dependency in dst_confirm() of dst's having an attached neigh. While we're here, remove the explicit 'dst' NULL check, all except 2 or 3 call sites ensure it's not NULL. So just fix those cases up. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-17include/net/dst.h: neaten asterisk placementEldad Zack1-9/+8
Fix code style - place the asterisk where it belongs. Signed-off-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-27ipv6: fix incorrect ipsec fragmentGao feng1-0/+1
Since commit ad0081e43a "ipv6: Fragment locally generated tunnel-mode IPSec6 packets as needed" the fragment of packets is incorrect. because tunnel mode needs IPsec headers and trailer for all fragments, while on transport mode it is sufficient to add the headers to the first fragment and the trailer to the last. so modify mtu and maxfraglen base on ipsec mode and if fragment is first or last. with my test,it work well(every fragment's size is the mtu) and does not trigger slow fragment path. Changes from v1: though optimization, mtu_prev and maxfraglen_prev can be delete. replace xfrm mode codes with dst_entry's new frag DST_XFRM_TUNNEL. add fuction ip6_append_data_mtu to make codes clearer. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-24set fake_rtable's dst to NULL to avoid kernel OopsPeter Huang (Peng)1-0/+1
bridge: set fake_rtable's dst to NULL to avoid kernel Oops when bridge is deleted before tap/vif device's delete, kernel may encounter an oops because of NULL reference to fake_rtable's dst. Set fake_rtable's dst to NULL before sending packets out can solve this problem. v4 reformat, change br_drop_fake_rtable(skb) to {} v3 enrich commit header v2 introducing new flag DST_FAKE_RTABLE to dst_entry struct. [ Use "do { } while (0)" for nop br_drop_fake_rtable() implementation -DaveM ] Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Peter Huang <peter.huangpeng@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13ipv6: fix problem with expired dst cacheGao feng1-1/+5
If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet. this dst cache will not check expire because it has no RTF_EXPIRES flag. So this dst cache will always be used until the dst gc run. Change the struct dst_entry,add a union contains new pointer from and expires. When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use. we can use this field to point to where the dst cache copy from. The dst.from is only used in IPV6. rt6_check_expired check if rt6_info.dst.from is expired. ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. ip6_dst_destroy release the ort. Add some functions to operate the RTF_EXPIRES flag and expires(from) together. and change the code to use these new adding functions. Changes from v5: modify ip6_route_add and ndisc_router_discovery to use new adding functions. Only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-05BUG: headers with BUG/BUG_ON etc. need linux/bug.hPaul Gortmaker1-0/+1
If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including <linux/bug.h> and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+1
Conflicts: net/bluetooth/l2cap_core.c Just two overlapping changes, one added an initialization of a local variable, and another change added a new local variable. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-23net: introduce DST_NOPEER dst flagEric Dumazet1-0/+1
Chris Boot reported crashes occurring in ipv6_select_ident(). [ 461.457562] RIP: 0010:[<ffffffff812dde61>] [<ffffffff812dde61>] ipv6_select_ident+0x31/0xa7 [ 461.578229] Call Trace: [ 461.580742] <IRQ> [ 461.582870] [<ffffffff812efa7f>] ? udp6_ufo_fragment+0x124/0x1a2 [ 461.589054] [<ffffffff812dbfe0>] ? ipv6_gso_segment+0xc0/0x155 [ 461.595140] [<ffffffff812700c6>] ? skb_gso_segment+0x208/0x28b [ 461.601198] [<ffffffffa03f236b>] ? ipv6_confirm+0x146/0x15e [nf_conntrack_ipv6] [ 461.608786] [<ffffffff81291c4d>] ? nf_iterate+0x41/0x77 [ 461.614227] [<ffffffff81271d64>] ? dev_hard_start_xmit+0x357/0x543 [ 461.620659] [<ffffffff81291cf6>] ? nf_hook_slow+0x73/0x111 [ 461.626440] [<ffffffffa0379745>] ? br_parse_ip_options+0x19a/0x19a [bridge] [ 461.633581] [<ffffffff812722ff>] ? dev_queue_xmit+0x3af/0x459 [ 461.639577] [<ffffffffa03747d2>] ? br_dev_queue_push_xmit+0x72/0x76 [bridge] [ 461.646887] [<ffffffffa03791e3>] ? br_nf_post_routing+0x17d/0x18f [bridge] [ 461.653997] [<ffffffff81291c4d>] ? nf_iterate+0x41/0x77 [ 461.659473] [<ffffffffa0374760>] ? br_flood+0xfa/0xfa [bridge] [ 461.665485] [<ffffffff81291cf6>] ? nf_hook_slow+0x73/0x111 [ 461.671234] [<ffffffffa0374760>] ? br_flood+0xfa/0xfa [bridge] [ 461.677299] [<ffffffffa0379215>] ? nf_bridge_update_protocol+0x20/0x20 [bridge] [ 461.684891] [<ffffffffa03bb0e5>] ? nf_ct_zone+0xa/0x17 [nf_conntrack] [ 461.691520] [<ffffffffa0374760>] ? br_flood+0xfa/0xfa [bridge] [ 461.697572] [<ffffffffa0374812>] ? NF_HOOK.constprop.8+0x3c/0x56 [bridge] [ 461.704616] [<ffffffffa0379031>] ? nf_bridge_push_encap_header+0x1c/0x26 [bridge] [ 461.712329] [<ffffffffa037929f>] ? br_nf_forward_finish+0x8a/0x95 [bridge] [ 461.719490] [<ffffffffa037900a>] ? nf_bridge_pull_encap_header+0x1c/0x27 [bridge] [ 461.727223] [<ffffffffa0379974>] ? br_nf_forward_ip+0x1c0/0x1d4 [bridge] [ 461.734292] [<ffffffff81291c4d>] ? nf_iterate+0x41/0x77 [ 461.739758] [<ffffffffa03748cc>] ? __br_deliver+0xa0/0xa0 [bridge] [ 461.746203] [<ffffffff81291cf6>] ? nf_hook_slow+0x73/0x111 [ 461.751950] [<ffffffffa03748cc>] ? __br_deliver+0xa0/0xa0 [bridge] [ 461.758378] [<ffffffffa037533a>] ? NF_HOOK.constprop.4+0x56/0x56 [bridge] This is caused by bridge netfilter special dst_entry (fake_rtable), a special shared entry, where attaching an inetpeer makes no sense. Problem is present since commit 87c48fa3b46 (ipv6: make fragment identifications less predictable) Introduce DST_NOPEER dst flag and make sure ipv6_select_ident() and __ip_select_ident() fallback to the 'no peer attached' handling. Reported-by: Chris Boot <bootc@bootc.net> Tested-by: Chris Boot <bootc@bootc.net> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-06net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}.David Miller1-3/+3
To reflect the fact that a refrence is not obtained to the resulting neighbour entry. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Roland Dreier <roland@purestorage.com>
2011-11-26net: Move mtu handling down to the protocol depended handlersSteffen Klassert1-6/+1
We move all mtu handling from dst_mtu() down to the protocol layer. So each protocol can implement the mtu handling in a different manner. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26net: Rename the dst_opt default_mtu method to mtuSteffen Klassert1-1/+1
We plan to invoke the dst_opt->default_mtu() method unconditioally from dst_mtu(). So rename the method to dst_opt->mtu() to match the name with the new meaning. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-18rps: Add flag to skb to indicate rxhash is based on L4 tupleTom Herbert1-1/+8
The l4_rxhash flag was added to the skb structure to indicate that the rxhash value was computed over the 4 tuple for the packet which includes the port information in the encapsulated transport packet. This is used by the stack to preserve the rxhash value in __skb_rx_tunnel. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-03net: fix NULL dereferences in check_peer_redir()Eric Dumazet1-4/+13
Gergely Kalman reported crashes in check_peer_redir(). It appears commit f39925dbde778 (ipv4: Cache learned redirect information in inetpeer.) added a race, leading to possible NULL ptr dereference. Since we can now change dst neighbour, we should make sure a reader can safely use a neighbour. Add RCU protection to dst neighbour, and make sure check_peer_redir() can be called safely by different cpus in parallel. As neighbours are already freed after one RCU grace period, this patch should not add typical RCU penalty (cache cold effects) Many thanks to Gergely for providing a pretty report pointing to the bug. Reported-by: Gergely Kalman <synapse@hippy.csoma.elte.hu> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-18net: Add ->neigh_lookup() operation to dst_opsDavid S. Miller1-0/+5
In the future dst entries will be neigh-less. In that environment we need to have an easy transition point for current users of dst->neighbour outside of the packet output fast path. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-18net: Abstract dst->neighbour accesses behind helpers.David S. Miller1-3/+15
dst_{get,set}_neighbour() Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-14net: Embed hh_cache inside of struct neighbour.David S. Miller1-9/+9
Now that there is a one-to-one correspondance between neighbour and hh_cache entries, we no longer need: 1) dynamic allocation 2) attachment to dst->hh 3) refcounting Initialization of the hh_cache entry is indicated by hh_len being non-zero, and such initialization is always done with the neighbour's lock held as a writer. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-02ipv6: Don't put artificial limit on routing table size.David S. Miller1-0/+1
IPV6, unlike IPV4, doesn't have a routing cache. Routing table entries, as well as clones made in response to route lookup requests, all live in the same table. And all of these things are together collected in the destination cache table for ipv6. This means that routing table entries count against the garbage collection limits, even though such entries cannot ever be reclaimed and are added explicitly by the administrator (rather than being created in response to lookups). Therefore it makes no sense to count ipv6 routing table entries against the GC limits. Add a DST_NOCOUNT destination cache entry flag, and skip the counting if it is set. Use this flag bit in ipv6 when adding routing table entries. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-24dst: catch uninitialized metricsStephen Hemminger1-0/+2
Catch cases where dst_metric_set() and other functions are called but _metrics is NULL. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-19ipv4: Kill RT_CACHE_DEBUGDavid S. Miller1-7/+0
It's way past it's usefulness. And this gets rid of a bunch of stray ->rt_{dst,src} references. Even the comment documenting the macro was inaccurate (stated default was 1 when it's 0). If reintroduced, it should be done properly, with dynamic debug facilities. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-29net: Make dst_alloc() take more explicit initializations.David S. Miller1-1/+2
Now the dst->dev, dev->obsolete, and dst->flags values can be specified as well. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-24net: Remove __KERNEL__ cpp checks from include/netDavid S. Miller1-3/+0
These header files are never installed to user consumption, so any __KERNEL__ cpp checks are superfluous. Projects should also not copy these files into their userland utility sources and try to use them there. If they insist on doing so, the onus is on them to sanitize the headers as needed. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-28dst: Clone child entry in skb_dst_popSteffen Klassert1-1/+1
We clone the child entry in skb_dst_pop before we call skb_dst_drop(). Otherwise we might kill the child right before we return it to the caller. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03xfrm: Return dst directly from xfrm_lookup()David S. Miller1-6/+8
Instead of on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02xfrm: Handle blackhole route creation via afinfo.David S. Miller1-8/+0
That way we don't have to potentially do this in every xfrm_lookup() caller. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02xfrm: Kill XFRM_LOOKUP_WAIT flag.David S. Miller1-2/+1
This can be determined from the flow flags instead. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-23net: Make flow cache paths use a const struct flowi.David S. Miller1-4/+6
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-18net: Add initial_ref arg to dst_alloc().David S. Miller1-1/+1
This allows avoiding multiple writes to the initial __refcnt. The most simplest cases of wanting an initial reference of "1" in ipv4 and ipv6 have been converted, the rest have been left along and kept at the existing "0". Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-09net: Remove bogus barrier() in dst_allfrag().David S. Miller1-2/+0
I simply missed this one when modifying the other dst metric interfaces earlier. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-05inetpeer: Move ICMP rate limiting state into inet_peer entries.David S. Miller1-2/+0
Like metrics, the ICMP rate limiting bits are cached state about a destination. So move it into the inet_peer entries. If an inet_peer cannot be bound (the reason is memory allocation failure or similar), the policy is to allow. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-29ipv4: Attach FIB info to dst_default_metrics when possibleDavid S. Miller1-0/+1
If there are no explicit metrics attached to a route, hook fi->fib_info up to dst_default_metrics. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-27net: Implement read-only protection and COW'ing of metrics.David S. Miller1-37/+77
Routing metrics are now copy-on-write. Initially a route entry points it's metrics at a read-only location. If a routing table entry exists, it will point there. Else it will point at the all zero metric place-holder called 'dst_default_metrics'. The writeability state of the metrics is stored in the low bits of the metrics pointer, we have two bits left to spare if we want to store more states. For the initial implementation, COW is implemented simply via kmalloc. However future enhancements will change this to place the writable metrics somewhere else, in order to increase sharing. Very likely this "somewhere else" will be the inetpeer cache. Note also that this means that metrics updates may transiently fail if we cannot COW the metrics successfully. But even by itself, this patch should decrease memory usage and increase cache locality especially for routing workloads. In those cases the read-only metric copies stay in place and never get written to. TCP workloads where metrics get updated, and those rare cases where PMTU triggers occur, will take a very slight performance hit. But that hit will be alleviated when the long-term writable metrics move to a more sharable location. Since the metrics storage went from a u32 array of RTAX_MAX entries to what is essentially a pointer, some retooling of the dst_entry layout was necessary. Most importantly, we need to preserve the alignment of the reference count so that it doesn't share cache lines with the read-mostly state, as per Eric Dumazet's alignment assertion checks. The only non-trivial bit here is the move of the 'flags' member into the writeable cacheline. This is OK since we are always accessing the flags around the same moment when we made a modification to the reference count. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-14Merge branch 'master' of git://1984.lsi.us.es/net-next-2.6Patrick McHardy1-10/+50
Conflicts: net/ipv4/route.c Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-01-14netfilter: fix Kconfig dependenciesPatrick McHardy1-1/+1
Fix dependencies of netfilter realm match: it depends on NET_CLS_ROUTE, which itself depends on NET_SCHED; this dependency is missing from netfilter. Since matching on realms is also useful without having NET_SCHED enabled and the option really only controls whether the tclassid member is included in route and dst entries, rename the config option to IP_ROUTE_CLASSID and move it outside of traffic scheduling context to get rid of the NET_SCHED dependeny. Reported-by: Vladis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-12-15net: Abstract default MTU metric calculation behind an accessor.David S. Miller1-7/+8
Like RTAX_ADVMSS, make the default calculation go through a dst_ops method rather than caching the computation in the routing cache entries. Now dst metrics are pretty much left as-is when new entries are created, thus optimizing metric sharing becomes a real possibility. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-13net: Abstract default ADVMSS behind an accessor.David S. Miller1-1/+13
Make all RTAX_ADVMSS metric accesses go through a new helper function, dst_metric_advmss(). Leave the actual default metric as "zero" in the real metric slot, and compute the actual default value dynamically via a new dst_ops AF specific callback. For stacked IPSEC routes, we use the advmss of the path which preserves existing behavior. Unlike ipv4/ipv6, DecNET ties the advmss to the mtu and thus updates advmss on pmtu updates. This inconsistency in advmss handling results in more raw metric accesses than I wish we ended up with. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-13ipv4: Don't pre-seed hoplimit metric.David S. Miller1-6/+0
Always go through a new ip4_dst_hoplimit() helper, just like ipv6. This allowed several simplifications: 1) The interim dst_metric_hoplimit() can go as it's no longer userd. 2) The sysctl_ip_default_ttl entry no longer needs to use ipv4_doint_and_flush, since the sysctl is not cached in routing cache metrics any longer. 3) ipv4_doint_and_flush no longer needs to be exported and therefore can be marked static. When ipv4_doint_and_flush_strategy was removed some time ago, the external declaration in ip.h was mistakenly left around so kill that off too. We have to move the sysctl_ip_default_ttl declaration into ipv4's route cache definition header net/route.h, because currently net/ip.h (where the declaration lives now) has a back dependency on net/route.h Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-13net: Abstract RTAX_HOPLIMIT metric accesses behind helper.David S. Miller1-1/+14
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-09net: Abstract away all dst_entry metrics accesses.David S. Miller1-3/+23
Use helper functions to hide all direct accesses, especially writes, to dst_entry metrics values. This will allow us to: 1) More easily change how the metrics are stored. 2) Implement COW for metrics. In particular this will help us put metrics into the inetpeer cache if that is what we end up doing. We can make the _metrics member a pointer instead of an array, initially have it point at the read-only metrics in the FIB, and then on the first set grab an inetpeer entry and point the _metrics member there. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2010-11-09decnet: RCU conversion and get rid of dev_base_lockEric Dumazet1-4/+4
While tracking dev_base_lock users, I found decnet used it in dnet_select_source(), but for a wrong purpose: Writers only hold RTNL, not dev_base_lock, so readers must use RCU if they cannot use RTNL. Adds an rcu_head in struct dn_ifaddr and handle proper RCU management. Adds __rcu annotation in dn_route as well. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-27ipv4: add __rcu annotations to routes.cEric Dumazet1-1/+1
Add __rcu annotations to : (struct dst_entry)->rt_next (struct rt_hash_bucket)->chain And use appropriate rcu primitives to reduce sparse warnings if CONFIG_SPARSE_RCU_POINTER=y Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-04net: introduce DST_NOCACHE flagEric Dumazet1-4/+5
While doing stress tests with IP route cache disabled, and multi queue devices, I noticed a very high contention on one rwlock used in neighbour code. When many cpus are trying to send frames (possibly using a high performance multiqueue device) to the same neighbour, they fight for the neigh->lock rwlock in order to call neigh_hh_init(), and fight on hh->hh_refcnt (a pair of atomic_inc/atomic_dec_and_test()) But we dont need to call neigh_hh_init() for dst that are used only once. It costs four atomic operations at least, on two contended cache lines, plus the high contention on neigh->lock rwlock. Introduce a new dst flag, DST_NOCACHE, that is set when dst was not inserted in route cache. With the stress test bench, sending 160000000 frames on one neighbour, results are : Before patch: real 2m28.406s user 0m11.781s sys 36m17.964s After patch: real 1m26.532s user 0m12.185s sys 20m3.903s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-28tunnels: prepare percpu accountingEric Dumazet1-5/+19
Tunnels are going to use percpu for their accounting. They are going to use a new tstats field in net_device. skb_tunnel_rx() is changed to be a wrapper around __skb_tunnel_rx() IPTUNNEL_XMIT() is changed to be a wrapper around __IPTUNNEL_XMIT() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27net: reset skb queue mapping when rx'ing over tunnelTom Herbert1-0/+1
Reset queue mapping when an skb is reentering the stack via a tunnel. On second pass, the queue mapping from the original device is no longer valid. Signed-off-by: Tom Herbert <therbert@google.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-05net: check for refcount if pop a stacked dst_entrySteffen Klassert1-3/+3
xfrm triggers a warning if dst_pop() drops a refcount on a noref dst. This patch changes dst_pop() to skb_dst_pop(). skb_dst_pop() drops the refcnt only on a refcounted dst. Also we don't clone the child dst_entry, so it is not refcounted and we can use skb_dst_set_noref() in xfrm_output_one(). Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-18net: Introduce skb_tunnel_rx() helperEric Dumazet1-0/+20
skb rxhash should be cleared when a skb is handled by a tunnel before being delivered again, so that correct packet steering can take place. There are other cleanups and accounting that we can factorize in a new helper, skb_tunnel_rx() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-18net: add a noref bit on skb dstEric Dumazet1-3/+45
Use low order bit of skb->_skb_dst to tell dst is not refcounted. Change _skb_dst to _skb_refdst to make sure all uses are catched. skb_dst() returns the dst, regardless of noref bit set or not, but with a lockdep check to make sure a noref dst is not given if current user is not rcu protected. New skb_dst_set_noref() helper to set an notrefcounted dst on a skb. (with lockdep check) skb_dst_drop() drops a reference only if skb dst was refcounted. skb_dst_force() helper is used to force a refcount on dst, when skb is queued and not anymore RCU protected. Use skb_dst_force() in __sk_add_backlog(), __dev_xmit_skb() if !IFF_XMIT_DST_RELEASE or skb enqueued on qdisc queue, in sock_queue_rcv_skb(), in __nf_queue(). Use skb_dst_force() in dev_requeue_skb(). Note: dst_use_noref() still dirties dst, we might transform it later to do one dirtying per jiffies. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-13net: sk_dst_cache RCUificationEric Dumazet1-15/+0
With latest CONFIG_PROVE_RCU stuff, I felt more comfortable to make this work. sk->sk_dst_cache is currently protected by a rwlock (sk_dst_lock) This rwlock is readlocked for a very small amount of time, and dst entries are already freed after RCU grace period. This calls for RCU again :) This patch converts sk_dst_lock to a spinlock, and use RCU for readers. __sk_dst_get() is supposed to be called with rcu_read_lock() or if socket locked by user, so use appropriate rcu_dereference_check() condition (rcu_read_lock_held() || sock_owned_by_user(sk)) This patch avoids two atomic ops per tx packet on UDP connected sockets, for example, and permits sk_dst_lock to be much less dirtied. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>