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2021-03-10net, bpf: Fix ip6ip6 crash with collect_md populated skbsDaniel Borkmann
I ran into a crash where setting up a ip6ip6 tunnel device which was /not/ set to collect_md mode was receiving collect_md populated skbs for xmit. The BPF prog was populating the skb via bpf_skb_set_tunnel_key() which is assigning special metadata dst entry and then redirecting the skb to the device, taking ip6_tnl_start_xmit() -> ipxip6_tnl_xmit() -> ip6_tnl_xmit() and in the latter it performs a neigh lookup based on skb_dst(skb) where we trigger a NULL pointer dereference on dst->ops->neigh_lookup() since the md_dst_ops do not populate neigh_lookup callback with a fake handler. Transform the md_dst_ops into generic dst_blackhole_ops that can also be reused elsewhere when needed, and use them for the metadata dst entries as callback ops. Also, remove the dst_md_discard{,_out}() ops and rely on dst_discard{,_out}() from dst_init() which free the skb the same way modulo the splat. Given we will be able to recover just fine from there, avoid any potential splats iff this gets ever triggered in future (or worse, panic on warns when set). Fixes: f38a9eb1f77b ("dst: Metadata destinations") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-10net: Consolidate common blackhole dst opsDaniel Borkmann
Move generic blackhole dst ops to the core and use them from both ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No functional change otherwise. We need these also in other locations and having to define them over and over again is not great. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10net: Correct the comment of dst_dev_put()Miaohe Lin
Since commit 8d7017fd621d ("blackhole_netdev: use blackhole_netdev to invalidate dst entries"), we use blackhole_netdev to invalidate dst entries instead of loopback device anymore. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-08net/dst: use a smaller percpu_counter batch for dst entries accountingEric Dumazet
percpu_counter_add() uses a default batch size which is quite big on platforms with 256 cpus. (2*256 -> 512) This means dst_entries_get_fast() can be off by +/- 2*(nr_cpus^2) (131072 on servers with 256 cpus) Reduce the batch size to something more reasonable, and add logic to ip6_dst_gc() to call dst_entries_get_slow() before calling the _very_ expensive fib6_run_gc() function. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2019-09-26net: print proper warning on dst underflowJason A. Donenfeld
Proper warnings with stack traces make it much easier to figure out what's doing the double free and create more meaningful bug reports from users. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-01blackhole_netdev: use blackhole_netdev to invalidate dst entriesMahesh Bandewar
Use blackhole_netdev instead of 'lo' device with lower MTU when marking dst "dead". Signed-off-by: Mahesh Bandewar <maheshb@google.com> Tested-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-21net: dst: remove gc leftoversJulian Wiedmann
Get rid of some obsolete gc-related documentation and macros that were missed in commit 5b7c9a8ff828 ("net: remove dst gc related code"). CC: Wei Wang <weiwan@google.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-17net: add a route cache full diagnostic messagePeter Oskolkov
In some testing scenarios, dst/route cache can fill up so quickly that even an explicit GC call occasionally fails to clean it up. This leads to sporadically failing calls to dst_alloc and "network unreachable" errors to the user, which is confusing. This patch adds a diagnostic message to make the cause of the failure easier to determine. Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03netfilter: nf_tables: add tunnel supportPablo Neira Ayuso
This patch implements the tunnel object type that can be used to configure tunnels via metadata template through the existing lightweight API from the ingress path. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-17net/ipv6: move metrics from dst to rt6_infoDavid Ahern
Similar to IPv4, add fib metrics to the fib struct, which at the moment is rt6_info. Will be moved to fib6_info in a later patch. Copy metrics into dst by reference using refcount. To make the transition: - add dst_metrics to rt6_info. Default to dst_default_metrics if no metrics are passed during route add. No need for a separate pmtu entry; it can reference the MTU slot in fib6_metrics - ip6_convert_metrics allocates memory in the FIB entry and uses ip_metrics_convert to copy from netlink attribute to metrics entry - the convert metrics call is done in ip6_route_info_create simplifying the route add path + fib6_commit_metrics and fib6_copy_metrics and the temporary mx6_config are no longer needed - add fib6_metric_set helper to change the value of a metric in the fib entry since dst_metric_set can no longer be used - cow_metrics for IPv6 can drop to dst_cow_metrics_generic - rt6_dst_from_metrics_check is no longer needed - rt6_fill_node needs the FIB entry and dst as separate arguments to keep compatibility with existing output. Current dst address is renamed to dest. (to be consistent with IPv4 rt6_fill_node really should be split into 2 functions similar to fib_dump_info and rt_fill_info) - rt6_fill_node no longer needs the temporary metrics variable Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-30net: Remove dst->nextDavid Miller
There are no more users. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30xfrm: Move dst->path into struct xfrm_dstDavid Miller
The first member of an IPSEC route bundle chain sets it's dst->path to the underlying ipv4/ipv6 route that carries the bundle. Stated another way, if one were to follow the xfrm_dst->child chain of the bundle, the final non-NULL pointer would be the path and point to either an ipv4 or an ipv6 route. This is largely used to make sure that PMTU events propagate down to the correct ipv4 or ipv6 route. When we don't have the top of an IPSEC bundle 'dst->path == dst'. Move it down into xfrm_dst and key off of dst->xfrm. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30ipv6: Move dst->from into struct rt6_info.David Miller
The dst->from value is only used by ipv6 routes to track where a route "came from". Any time we clone or copy a core ipv6 route in the ipv6 routing tables, we have the copy/clone's ->from point to the base route. This is used to handle route expiration properly. Only ipv6 uses this mechanism, and only ipv6 code references it. So it is safe to move it into rt6_info. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30xfrm: Move child route linkage into xfrm_dst.David Miller
XFRM bundle child chains look like this: xdst1 --> xdst2 --> xdst3 --> path_dst All of xdstN are xfrm_dst objects and xdst->u.dst.xfrm is non-NULL. The final child pointer in the chain, here called 'path_dst', is some other kind of route such as an ipv4 or ipv6 one. The xfrm output path pops routes, one at a time, via the child pointer, until we hit one which has a dst->xfrm pointer which is NULL. We can easily preserve the above mechanisms with child sitting only in the xfrm_dst structure. All children in the chain before we break out of the xfrm_output() loop have dst->xfrm non-NULL and are therefore xfrm_dst objects. Since we break out of the loop when we find dst->xfrm NULL, we will not try to dereference 'dst' as if it were an xfrm_dst. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-30net: Create and use new helper xfrm_dst_child().David Miller
Only IPSEC routes have a non-NULL dst->child pointer. And IPSEC routes are identified by a non-NULL dst->xfrm pointer. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10net: dst: move cpu inside ifdef to avoid compilation warningJakub Kicinski
If CONFIG_DST_CACHE is not selected cpu variable will be unused and we will see a compilation warning. Move it under the ifdef. Reported-by: kbuild test robot <fengguang.wu@intel.com> Fixes: d66f2b91f95b ("bpf: don't rely on the verifier lock for metadata_dst allocation") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-10bpf: don't rely on the verifier lock for metadata_dst allocationJakub Kicinski
bpf_skb_set_tunnel_*() functions require allocation of per-cpu metadata_dst. The allocation happens upon verification of the first program using those helpers. In preparation for removing the verifier lock, use cmpxchg() to make sure we only allocate the metadata_dsts once. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21net: check type when freeing metadata dstDavid Lamparter
Commit 3fcece12bc1b ("net: store port/representator id in metadata_dst") added a new type field to metadata_dst, but metadata_dst_free() wasn't updated to check it before freeing the METADATA_IP_TUNNEL specific dst cache entry. This is not currently causing problems since it's far enough back in the struct to be zeroed for the only other type currently in existance (METADATA_HW_PORT_MUX), but nevertheless it's not correct. Fixes: 3fcece12bc1b ("net: store port/representator id in metadata_dst") Signed-off-by: David Lamparter <equinox@diac24.net> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Sridhar Samudrala <sridhar.samudrala@intel.com> Cc: Simon Horman <horms@verge.net.au> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18ipv4: convert dst_metrics.refcnt from atomic_t to refcount_tEric Dumazet
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-25net: store port/representator id in metadata_dstJakub Kicinski
Switches and modern SR-IOV enabled NICs may multiplex traffic from Port representators and control messages over single set of hardware queues. Control messages and muxed traffic may need ordered delivery. Those requirements make it hard to comfortably use TC infrastructure today unless we have a way of attaching metadata to skbs at the upper device. Because single set of queues is used for many netdevs stopping TC/sched queues of all of them reliably is impossible and lower device has to retreat to returning NETDEV_TX_BUSY and usually has to take extra locks on the fastpath. This patch attempts to enable port/representative devs to attach metadata to skbs which carry port id. This way representatives can be queueless and all queuing can be performed at the lower netdev in the usual way. Traffic arriving on the port/representative interfaces will be have metadata attached and will subsequently be queued to the lower device for transmission. The lower device should recognize the metadata and translate it to HW specific format which is most likely either a special header inserted before the network headers or descriptor/metadata fields. Metadata is associated with the lower device by storing the netdev pointer along with port id so that if TC decides to redirect or mirror the new netdev will not try to interpret it. This is mostly for SR-IOV devices since switches don't have lower netdevs today. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: remove DST_NOCACHE flagWei Wang
DST_NOCACHE flag check has been removed from dst_release() and dst_hold_safe() in a previous patch because all the dst are now ref counted properly and can be released based on refcnt only. Looking at the rest of the DST_NOCACHE use, all of them can now be removed or replaced with other checks. So this patch gets rid of all the DST_NOCACHE usage and remove this flag completely. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: remove DST_NOGC flagWei Wang
Now that all the components have been changed to release dst based on refcnt only and not depend on dst gc anymore, we can remove the temporary flag DST_NOGC. Note that we also need to remove the DST_NOCACHE check in dst_release() and dst_hold_safe() because now all the dst are released based on refcnt and behaves as DST_NOCACHE. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: remove dst gc related codeWei Wang
This patch removes all dst gc related code and all the dst free functions Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17xfrm: take refcnt of dst when creating struct xfrm_dst bundleWei Wang
During the creation of xfrm_dst bundle, always take ref count when allocating the dst. This way, xfrm_bundle_create() will form a linked list of dst with dst->child pointing to a ref counted dst child. And the returned dst pointer is also ref counted. This makes the link from the flow cache to this dst now ref counted properly. As the dst is always ref counted properly, we can safely mark DST_NOGC flag so dst_release() will release dst based on refcnt only. And dst gc is no longer needed and all dst_free() and its related function calls should be replaced with dst_release() or dst_release_immediate(). The special handling logic for dst->child in dst_destroy() can be replaced with a simple dst_release_immediate() call on the child to release the whole list linked by dst->child pointer. Previously used DST_NOHASH flag is not needed anymore as well. The reason that DST_NOHASH is used in the existing code is mainly to prevent the dst inserted in the fib tree to be wrongly destroyed during the deletion of the xfrm_dst bundle. So in the existing code, DST_NOHASH flag is marked in all the dst children except the one which is in the fib tree. However, with this patch series to remove dst gc logic and release dst only based on ref count, it is safe to release all the children from a xfrm_dst bundle as long as the dst children are all ref counted properly which is already the case in the existing code. So, this patch removes the use of DST_NOHASH flag. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: introduce a new function dst_dev_put()Wei Wang
This function should be called when removing routes from fib tree after the dst gc is no longer in use. We first mark DST_OBSOLETE_DEAD on this dst to make sure next dst_ops->check() fails and returns NULL. Secondly, as we no longer keep the gc_list, we need to properly release dst->dev right at the moment when the dst is removed from the fib/fib6 tree. It does the following: 1. change dst->input and output pointers to dst_discard/dst_dscard_out to discard all packets 2. replace dst->dev with loopback interface Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: introduce DST_NOGC in dst_release() to destroy dst based on refcntWei Wang
The current mechanism of freeing dst is a bit complicated. dst has its ref count and when user grabs the reference to the dst, the ref count is properly taken in most cases except in IPv4/IPv6/decnet/xfrm routing code due to some historic reasons. If the reference to dst is always taken properly, we should be able to simplify the logic in dst_release() to destroy dst when dst->__refcnt drops from 1 to 0. And this should be the only condition to determine if we can call dst_destroy(). And as dst is always ref counted, there is no need for a dst garbage list to hold the dst entries that already get removed by the routing code but are still held by other users. And the task to periodically check the list to free dst if ref count become 0 is also not needed anymore. This patch introduces a temporary flag DST_NOGC(no garbage collector). If it is set in the dst, dst_release() will call dst_destroy() when dst->__refcnt drops to 0. dst_hold_safe() will also check for this flag and do atomic_inc_not_zero() similar as DST_NOCACHE to avoid double free issue. This temporary flag is mainly used so that we can make the transition component by component without breaking other parts. This flag will be removed after all components are properly transitioned. This patch also introduces a new function dst_release_immediate() which destroys dst without waiting on the rcu when refcnt drops to 0. It will be used in later patches. Follow-up patches will correct all the places to properly take ref count on dst and mark DST_NOGC. dst_release() or dst_release_immediate() will be used to release the dst instead of dst_free() and its related functions. And final clean-up patch will remove the DST_NOGC flag. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-09Fix an intermittent pr_emerg warning about lo becoming free.Krister Johansen
It looks like this: Message from syslogd@flamingo at Apr 26 00:45:00 ... kernel:unregister_netdevice: waiting for lo to become free. Usage count = 4 They seem to coincide with net namespace teardown. The message is emitted by netdev_wait_allrefs(). Forced a kdump in netdev_run_todo, but found that the refcount on the lo device was already 0 at the time we got to the panic. Used bcc to check the blocking in netdev_run_todo. The only places where we're off cpu there are in the rcu_barrier() and msleep() calls. That behavior is expected. The msleep time coincides with the amount of time we spend waiting for the refcount to reach zero; the rcu_barrier() wait times are not excessive. After looking through the list of callbacks that the netdevice notifiers invoke in this path, it appears that the dst_dev_event is the most interesting. The dst_ifdown path places a hold on the loopback_dev as part of releasing the dev associated with the original dst cache entry. Most of our notifier callbacks are straight-forward, but this one a) looks complex, and b) places a hold on the network interface in question. I constructed a new bcc script that watches various events in the liftime of a dst cache entry. Note that dst_ifdown will take a hold on the loopback device until the invalidated dst entry gets freed. [ __dst_free] on DST: ffff883ccabb7900 IF tap1008300eth0 invoked at 1282115677036183 __dst_free rcu_nocb_kthread kthread ret_from_fork Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-26ipv4: add reference counting to metricsEric Dumazet
Andrey Konovalov reported crashes in ipv4_mtu() I could reproduce the issue with KASAN kernels, between 10.246.7.151 and 10.246.7.152 : 1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 & 2) At the same time run following loop : while : do ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500 done Cong Wang attempted to add back rt->fi in commit 82486aa6f1b9 ("ipv4: restore rt->fi for reference counting") but this proved to add some issues that were complex to solve. Instead, I suggested to add a refcount to the metrics themselves, being a standalone object (in particular, no reference to other objects) I tried to make this patch as small as possible to ease its backport, instead of being super clean. Note that we believe that only ipv4 dst need to take care of the metric refcount. But if this is wrong, this patch adds the basic infrastructure to extend this to other families. Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang for his efforts on this problem. Fixes: 2860583fe840 ("ipv4: Kill rt->fi") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07net: pending_confirm is not used anymoreJulian Anastasov
When same struct dst_entry can be used for many different neighbours we can not use it for pending confirmations. As last step, we can remove the pending_confirm flag. Reported-by: YueHaibing <yuehaibing@huawei.com> Fixes: 5110effee8fd ("net: Do delayed neigh confirmation.") Fixes: f2bb4bedf35d ("ipv4: Cache output routes in fib_info nexthops.") Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16net: add dst_cache to ovs vxlan lwtunnelPaolo Abeni
In case of UDP traffic with datagram length below MTU this give about 2% performance increase when tunneling over ipv4 and about 60% when tunneling over ipv6 Signed-off-by: Paolo Abeni <pabeni@redhat.com> Suggested-and-acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-06net: possible use after free in dst_releaseFrancesco Ruggeri
dst_release should not access dst->flags after decrementing __refcnt to 0. The dst_entry may be in dst_busy_list and dst_gc_task may dst_destroy it before dst_release gets a chance to access dst->flags. Fixes: d69bbf88c8d0 ("net: fix a race in dst_release()") Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst") Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-09net: fix a race in dst_release()Eric Dumazet
Only cpu seeing dst refcount going to 0 can safely dereference dst->flags. Otherwise an other cpu might already have freed the dst. Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst") Reported-by: Greg Thelen <gthelen@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08dst: Pass net into dst->outputEric W. Biederman
The network namespace is already passed into dst_output pass it into dst->output lwt->output and friends. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-31tun_dst: Remove opts_sizePravin B Shelar
opts_size is only written and never read. Following patch removes this unused variable. Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25route: fix a use-after-freeWANG Cong
This patch fixes the following crash: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.2.0-rc7+ #166 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff88010656d280 ti: ffff880106570000 task.ti: ffff880106570000 RIP: 0010:[<ffffffff8182f91b>] [<ffffffff8182f91b>] dst_destroy+0xa6/0xef RSP: 0018:ffff880107603e38 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff8800d225a000 RCX: ffffffff82250fd0 RDX: 0000000000000001 RSI: ffffffff82250fd0 RDI: 6b6b6b6b6b6b6b6b RBP: ffff880107603e58 R08: 0000000000000001 R09: 0000000000000001 R10: 000000000000b530 R11: ffff880107609000 R12: 0000000000000000 R13: ffffffff82343c40 R14: 0000000000000000 R15: ffffffff8182fb4f FS: 0000000000000000(0000) GS:ffff880107600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007fcabd9d3000 CR3: 00000000d7279000 CR4: 00000000000006e0 Stack: ffffffff82250fd0 ffff8801077d6f00 ffffffff82253c40 ffff8800d225a000 ffff880107603e68 ffffffff8182fb5d ffff880107603f08 ffffffff810d795e ffffffff810d7648 ffff880106574000 ffff88010656d280 ffff88010656d280 Call Trace: <IRQ> [<ffffffff8182fb5d>] dst_destroy_rcu+0xe/0x1d [<ffffffff810d795e>] rcu_process_callbacks+0x618/0x7eb [<ffffffff810d7648>] ? rcu_process_callbacks+0x302/0x7eb [<ffffffff8182fb4f>] ? dst_gc_task+0x1eb/0x1eb [<ffffffff8107e11b>] __do_softirq+0x178/0x39f [<ffffffff8107e52e>] irq_exit+0x41/0x95 [<ffffffff81a4f215>] smp_apic_timer_interrupt+0x34/0x40 [<ffffffff81a4d5cd>] apic_timer_interrupt+0x6d/0x80 <EOI> [<ffffffff8100b968>] ? default_idle+0x21/0x32 [<ffffffff8100b966>] ? default_idle+0x1f/0x32 [<ffffffff8100bf19>] arch_cpu_idle+0xf/0x11 [<ffffffff810b0bc7>] default_idle_call+0x1f/0x21 [<ffffffff810b0dce>] cpu_startup_entry+0x1ad/0x273 [<ffffffff8102fe67>] start_secondary+0x135/0x156 dst is freed right before lwtstate_put(), this is not correct... Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry") Acked-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-20route: move lwtunnel state to dst_entryJiri Benc
Currently, the lwtunnel state resides in per-protocol data. This is a problem if we encapsulate ipv6 traffic in an ipv4 tunnel (or vice versa). The xmit function of the tunnel does not know whether the packet has been routed to it by ipv4 or ipv6, yet it needs the lwtstate data. Moving the lwtstate data to dst_entry makes such inter-protocol tunneling possible. As a bonus, this brings a nice diffstat. Signed-off-by: Jiri Benc <jbenc@redhat.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31bpf: add helpers to access tunnel metadataAlexei Starovoitov
Introduce helpers to let eBPF programs attached to TC manipulate tunnel metadata: bpf_skb_[gs]et_tunnel_key(skb, key, size, flags) skb: pointer to skb key: pointer to 'struct bpf_tunnel_key' size: size of 'struct bpf_tunnel_key' flags: room for future extensions First eBPF program that uses these helpers will allocate per_cpu metadata_dst structures that will be used on TX. On RX metadata_dst is allocated by tunnel driver. Typical usage for TX: struct bpf_tunnel_key tkey; ... populate tkey ... bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0); bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); RX: struct bpf_tunnel_key tkey = {}; bpf_skb_get_tunnel_key(skb, &tkey, sizeof(tkey), 0); ... lookup or redirect based on tkey ... 'struct bpf_tunnel_key' will be extended in the future by adding elements to the end and the 'size' argument will indicate which fields are populated, thereby keeping backwards compatibility. The 'flags' argument may be used as well when the 'size' is not enough or to indicate completely different layout of bpf_tunnel_key. Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/bridge/br_mdb.c br_mdb.c conflict was a function call being removed to fix a bug in 'net' but whose signature was changed in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21dst: Metadata destinationsThomas Graf
Introduces a new dst_metadata which enables to carry per packet metadata between forwarding and processing elements via the skb->dst pointer. The structure is set up to be a union. Thus, each separate type of metadata requires its own dst instance. If demand arises to carry multiple types of metadata concurrently, metadata dst entries can be made stackable. The metadata dst entry is refcnt'ed as expected for now but a non reference counted use is possible if the reference is forced before queueing the skb. In order to allow allocating dsts with variable length, the existing dst_alloc() is split into a dst_alloc() and dst_init() function. The existing dst_init() function to initialize the subsystem is being renamed to dst_subsys_init() to make it clear what is what. The check before ip_route_input() is changed to ignore metadata dsts and drop the dst inside the routing function thus allowing to interpret metadata in a later commit. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21net: ratelimit warnings about dst entry refcount underflow or overflowKonstantin Khlebnikov
Kernel generates a lot of warnings when dst entry reference counter overflows and becomes negative. That bug was seen several times at machines with outdated 3.10.y kernels. Most like it's already fixed in upstream. Anyway that flood completely kills machine and makes further debugging impossible. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-09dst: no need to take reference on DST_NOCACHE dstsHannes Frederic Sowa
Since commit f8864972126899 ("ipv4: fix dst race in sk_dst_get()") DST_NOCACHE dst_entries get freed by RCU. So there is no need to get a reference on them when we are in rcu protected sections. Cc: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Reviewed-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-25ipv4: fix dst race in sk_dst_get()Eric Dumazet
When IP route cache had been removed in linux-3.6, we broke assumption that dst entries were all freed after rcu grace period. DST_NOCACHE dst were supposed to be freed from dst_release(). But it appears we want to keep such dst around, either in UDP sockets or tunnels. In sk_dst_get() we need to make sure dst refcount is not 0 before incrementing it, or else we might end up freeing a dst twice. DST_NOCACHE set on a dst does not mean this dst can not be attached to a socket or a tunnel. Then, before actual freeing, we need to observe a rcu grace period to make sure all other cpus can catch the fact the dst is no longer usable. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dormando <dormando@rydia.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-15ipv4: add a sock pointer to dst->output() path.Eric Dumazet
In the dst->output() path for ipv4, the code assumes the skb it has to transmit is attached to an inet socket, specifically via ip_mc_output() : The sk_mc_loop() test triggers a WARN_ON() when the provider of the packet is an AF_PACKET socket. The dst->output() method gets an additional 'struct sock *sk' parameter. This needs a cascade of changes so that this parameter can be propagated from vxlan to final consumer. Fixes: 8f646c922d55 ("vxlan: keep original skb ownership") Reported-by: lucien xin <lucien.xin@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-28net: pass info struct via netdevice notifierJiri Pirko
So far, only net_device * could be passed along with netdevice notifier event. This patch provides a possibility to pass custom structure able to provide info that event listener needs to know. Signed-off-by: Jiri Pirko <jiri@resnulli.us> v2->v3: fix typo on simeth shortened dev_getter shortened notifier_info struct name v1->v2: fix notifier_call parameter in call_netdevice_notifier() Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-02net: add skb_dst_set_noref_forceJulian Anastasov
Rename skb_dst_set_noref to __skb_dst_set_noref and add force flag as suggested by David Miller. The new wrapper skb_dst_set_noref_force will force dst entries that are not cached to be attached as skb dst without taking reference as long as provided dst is reclaimed after RCU grace period. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off by: Hans Schillstrom <hans@schillstrom.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Simon Horman <horms@verge.net.au>
2013-02-20ipv6: fix race condition regarding dst->expires and dst->from.YOSHIFUJI Hideaki / 吉藤英明
Eric Dumazet wrote: | Some strange crashes happen in rt6_check_expired(), with access | to random addresses. | | At first glance, it looks like the RTF_EXPIRES and | stuff added in commit 1716a96101c49186b | (ipv6: fix problem with expired dst cache) | are racy : same dst could be manipulated at the same time | on different cpus. | | At some point, our stack believes rt->dst.from contains a dst pointer, | while its really a jiffie value (as rt->dst.expires shares the same area | of memory) | | rt6_update_expires() should be fixed, or am I missing something ? | | CC Neil because of https://bugzilla.redhat.com/show_bug.cgi?id=892060 Because we do not have any locks for dst_entry, we cannot change essential structure in the entry; e.g., we cannot change reference to other entity. To fix this issue, split 'from' and 'expires' field in dst_entry out of union. Once it is 'from' is assigned in the constructor, keep the reference until the very last stage of the life time of the object. Of course, it is unsafe to change 'from', so make rt6_set_from simple just for fresh entries. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Neil Horman <nhorman@tuxdriver.com> CC: Gao Feng <gaofeng@cn.fujitsu.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reported-by: Steinar H. Gunderson <sesse@google.com> Reviewed-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking changes from David Miller: 1) GRE now works over ipv6, from Dmitry Kozlov. 2) Make SCTP more network namespace aware, from Eric Biederman. 3) TEAM driver now works with non-ethernet devices, from Jiri Pirko. 4) Make openvswitch network namespace aware, from Pravin B Shelar. 5) IPV6 NAT implementation, from Patrick McHardy. 6) Server side support for TCP Fast Open, from Jerry Chu and others. 7) Packet BPF filter supports MOD and XOR, from Eric Dumazet and Daniel Borkmann. 8) Increate the loopback default MTU to 64K, from Eric Dumazet. 9) Use a per-task rather than per-socket page fragment allocator for outgoing networking traffic. This benefits processes that have very many mostly idle sockets, which is quite common. From Eric Dumazet. 10) Use up to 32K for page fragment allocations, with fallbacks to smaller sizes when higher order page allocations fail. Benefits are a) less segments for driver to process b) less calls to page allocator c) less waste of space. From Eric Dumazet. 11) Allow GRO to be used on GRE tunnels, from Eric Dumazet. 12) VXLAN device driver, one way to handle VLAN issues such as the limitation of 4096 VLAN IDs yet still have some level of isolation. From Stephen Hemminger. 13) As usual there is a large boatload of driver changes, with the scale perhaps tilted towards the wireless side this time around. Fix up various fairly trivial conflicts, mostly caused by the user namespace changes. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1012 commits) hyperv: Add buffer for extended info after the RNDIS response message. hyperv: Report actual status in receive completion packet hyperv: Remove extra allocated space for recv_pkt_list elements hyperv: Fix page buffer handling in rndis_filter_send_request() hyperv: Fix the missing return value in rndis_filter_set_packet_filter() hyperv: Fix the max_xfer_size in RNDIS initialization vxlan: put UDP socket in correct namespace vxlan: Depend on CONFIG_INET sfc: Fix the reported priorities of different filter types sfc: Remove EFX_FILTER_FLAG_RX_OVERRIDE_IP sfc: Fix loopback self-test with separate_tx_channels=1 sfc: Fix MCDI structure field lookup sfc: Add parentheses around use of bitfield macro arguments sfc: Fix null function pointer in efx_sriov_channel_type vxlan: virtual extensible lan igmp: export symbol ip_mc_leave_group netlink: add attributes to fdb interface tg3: unconditionally select HWMON support when tg3 is enabled. Revert "net: ti cpsw ethernet: allow reading phy interface mode from DT" gre: fix sparse warning ...
2012-10-02Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue changes from Tejun Heo: "This is workqueue updates for v3.7-rc1. A lot of activities this round including considerable API and behavior cleanups. * delayed_work combines a timer and a work item. The handling of the timer part has always been a bit clunky leading to confusing cancelation API with weird corner-case behaviors. delayed_work is updated to use new IRQ safe timer and cancelation now works as expected. * Another deficiency of delayed_work was lack of the counterpart of mod_timer() which led to cancel+queue combinations or open-coded timer+work usages. mod_delayed_work[_on]() are added. These two delayed_work changes make delayed_work provide interface and behave like timer which is executed with process context. * A work item could be executed concurrently on multiple CPUs, which is rather unintuitive and made flush_work() behavior confusing and half-broken under certain circumstances. This problem doesn't exist for non-reentrant workqueues. While non-reentrancy check isn't free, the overhead is incurred only when a work item bounces across different CPUs and even in simulated pathological scenario the overhead isn't too high. All workqueues are made non-reentrant. This removes the distinction between flush_[delayed_]work() and flush_[delayed_]_work_sync(). The former is now as strong as the latter and the specified work item is guaranteed to have finished execution of any previous queueing on return. * In addition to the various bug fixes, Lai redid and simplified CPU hotplug handling significantly. * Joonsoo introduced system_highpri_wq and used it during CPU hotplug. There are two merge commits - one to pull in IRQ safe timer from tip/timers/core and the other to pull in CPU hotplug fixes from wq/for-3.6-fixes as Lai's hotplug restructuring depended on them." Fixed a number of trivial conflicts, but the more interesting conflicts were silent ones where the deprecated interfaces had been used by new code in the merge window, and thus didn't cause any real data conflicts. Tejun pointed out a few of them, I fixed a couple more. * 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits) workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending() workqueue: use cwq_set_max_active() helper for workqueue_set_max_active() workqueue: introduce cwq_set_max_active() helper for thaw_workqueues() workqueue: remove @delayed from cwq_dec_nr_in_flight() workqueue: fix possible stall on try_to_grab_pending() of a delayed work item workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback() workqueue: use __cpuinit instead of __devinit for cpu callbacks workqueue: rename manager_mutex to assoc_mutex workqueue: WORKER_REBIND is no longer necessary for idle rebinding workqueue: WORKER_REBIND is no longer necessary for busy rebinding workqueue: reimplement idle worker rebinding workqueue: deprecate __cancel_delayed_work() workqueue: reimplement cancel_delayed_work() using try_to_grab_pending() workqueue: use mod_delayed_work() instead of __cancel + queue workqueue: use irqsafe timer for delayed_work workqueue: clean up delayed_work initializers and add missing one workqueue: make deferrable delayed_work initializer names consistent workqueue: cosmetic whitespace updates for macro definitions workqueue: deprecate system_nrt[_freezable]_wq workqueue: deprecate flush[_delayed]_work_sync() ...
2012-08-22net: remove delay at device dismantleEric Dumazet
I noticed extra one second delay in device dismantle, tracked down to a call to dst_dev_event() while some call_rcu() are still in RCU queues. These call_rcu() were posted by rt_free(struct rtable *rt) calls. We then wait a little (but one second) in netdev_wait_allrefs() before kicking again NETDEV_UNREGISTER. As the call_rcu() are now completed, dst_dev_event() can do the needed device swap on busy dst. To solve this problem, add a new NETDEV_UNREGISTER_FINAL, called after a rcu_barrier(), but outside of RTNL lock. Use NETDEV_UNREGISTER_FINAL with care ! Change dst_dev_event() handler to react to NETDEV_UNREGISTER_FINAL Also remove NETDEV_UNREGISTER_BATCH, as its not used anymore after IP cache removal. With help from Gao feng Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>