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2017-01-24lwtunnel: Fix oops on state free after encap module unloadRobert Shearman1-1/+5
When attempting to free lwtunnel state after the module for the encap has been unloaded an oops occurs: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: lwtstate_free+0x18/0x40 [..] task: ffff88003e372380 task.stack: ffffc900001fc000 RIP: 0010:lwtstate_free+0x18/0x40 RSP: 0018:ffff88003fd83e88 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88002bbb3380 RCX: ffff88000c91a300 [..] Call Trace: <IRQ> free_fib_info_rcu+0x195/0x1a0 ? rt_fibinfo_free+0x50/0x50 rcu_process_callbacks+0x2d3/0x850 ? rcu_process_callbacks+0x296/0x850 __do_softirq+0xe4/0x4cb irq_exit+0xb0/0xc0 smp_apic_timer_interrupt+0x3d/0x50 apic_timer_interrupt+0x93/0xa0 [..] Code: e8 6e c6 fc ff 89 d8 5b 5d c3 bb de ff ff ff eb f4 66 90 66 66 66 66 90 55 48 89 e5 53 0f b7 07 48 89 fb 48 8b 04 c5 00 81 d5 81 <48> 8b 40 08 48 85 c0 74 13 ff d0 48 8d 7b 20 be 20 00 00 00 e8 The problem is after the module for the encap can be unloaded the corresponding ops is removed and is thus NULL here. Modules implementing lwtunnel ops should not be allowed to unload while there is state alive using those ops, so grab the module reference for the ops on creating lwtunnel state and of course release the reference when freeing the state. Fixes: 1104d9ba443a ("lwtunnel: Add destroy state operation") Signed-off-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18lwtunnel: fix autoload of lwt modulesDavid Ahern1-6/+56
Trying to add an mpls encap route when the MPLS modules are not loaded hangs. For example: CONFIG_MPLS=y CONFIG_NET_MPLS_GSO=m CONFIG_MPLS_ROUTING=m CONFIG_MPLS_IPTUNNEL=m $ ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2 The ip command hangs: root 880 826 0 21:25 pts/0 00:00:00 ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2 $ cat /proc/880/stack [<ffffffff81065a9b>] call_usermodehelper_exec+0xd6/0x134 [<ffffffff81065efc>] __request_module+0x27b/0x30a [<ffffffff814542f6>] lwtunnel_build_state+0xe4/0x178 [<ffffffff814aa1e4>] fib_create_info+0x47f/0xdd4 [<ffffffff814ae451>] fib_table_insert+0x90/0x41f [<ffffffff814a8010>] inet_rtm_newroute+0x4b/0x52 ... modprobe is trying to load rtnl-lwt-MPLS: root 881 5 0 21:25 ? 00:00:00 /sbin/modprobe -q -- rtnl-lwt-MPLS and it hangs after loading mpls_router: $ cat /proc/881/stack [<ffffffff81441537>] rtnl_lock+0x12/0x14 [<ffffffff8142ca2a>] register_netdevice_notifier+0x16/0x179 [<ffffffffa0033025>] mpls_init+0x25/0x1000 [mpls_router] [<ffffffff81000471>] do_one_initcall+0x8e/0x13f [<ffffffff81119961>] do_init_module+0x5a/0x1e5 [<ffffffff810bd070>] load_module+0x13bd/0x17d6 ... The problem is that lwtunnel_build_state is called with rtnl lock held preventing mpls_init from registering. Given the potential references held by the time lwtunnel_build_state it can not drop the rtnl lock to the load module. So, extract the module loading code from lwtunnel_build_state into a new function to validate the encap type. The new function is called while converting the user request into a fib_config which is well before any table, device or fib entries are examined. Fixes: 745041e2aaf1 ("lwtunnel: autoload of lwt modules") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02bpf: BPF for lightweight tunnel infrastructureThomas Graf1-0/+2
Registers new BPF program types which correspond to the LWT hooks: - BPF_PROG_TYPE_LWT_IN => dst_input() - BPF_PROG_TYPE_LWT_OUT => dst_output() - BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit() The separate program types are required to differentiate between the capabilities each LWT hook allows: * Programs attached to dst_input() or dst_output() are restricted and may only read the data of an skb. This prevent modification and possible invalidation of already validated packet headers on receive and the construction of illegal headers while the IP headers are still being assembled. * Programs attached to lwtunnel_xmit() are allowed to modify packet content as well as prepending an L2 header via a newly introduced helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is invoked after the IP header has been assembled completely. All BPF programs receive an skb with L3 headers attached and may return one of the following error codes: BPF_OK - Continue routing as per nexthop BPF_DROP - Drop skb and return EPERM BPF_REDIRECT - Redirect skb to device as per redirect() helper. (Only valid in lwtunnel_xmit() context) The return codes are binary compatible with their TC_ACT_ relatives to ease compatibility. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09ipv6: sr: add support for SRH encapsulation and injection with lwtunnelsDavid Lebrun1-0/+2
This patch creates a new type of interfaceless lightweight tunnel (SEG6), enabling the encapsulation and injection of SRH within locally emitted packets and forwarded packets. >From a configuration viewpoint, a seg6 tunnel would be configured as follows: ip -6 ro ad fc00::1/128 encap seg6 mode encap segs fc42::1,fc42::2,fc42::3 dev eth0 Any packet whose destination address is fc00::1 would thus be encapsulated within an outer IPv6 header containing the SRH with three segments, and would actually be routed to the first segment of the list. If `mode inline' was specified instead of `mode encap', then the SRH would be directly inserted after the IPv6 header without outer encapsulation. The inline mode is only available if CONFIG_IPV6_SEG6_INLINE is enabled. This feature was made configurable because direct header insertion may break several mechanisms such as PMTUD or IPSec AH. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-15lwtunnel: Add destroy state operationTom Herbert1-0/+13
Users of lwt tunnels may set up some secondary state in build_state function. Add a corresponding destroy_state function to allow users to clean up state. This destroy state function is called from lwstate_free. Also, we now free lwstate using kfree_rcu so user can assume structure is not freed before rcu. Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30net: lwtunnel: Handle fragmentationRoopa Prabhu1-0/+35
Today mpls iptunnel lwtunnel_output redirect expects the tunnel output function to handle fragmentation. This is ok but can be avoided if we did not do the mpls output redirect too early. ie we could wait until ip fragmentation is done and then call mpls output for each ip fragment. To make this work we will need, 1) the lwtunnel state to carry encap headroom 2) and do the redirect to the encap output handler on the ip fragment (essentially do the output redirect after fragmentation) This patch adds tunnel headroom in lwtstate to make sure we account for tunnel data in mtu calculations during fragmentation and adds new xmit redirect handler to redirect to lwtunnel xmit func after ip fragmentation. This includes IPV6 and some mtu fixes and testing from David Ahern. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-21lwtunnel: autoload of lwt modulesRobert Shearman1-0/+37
The lwt implementations using net devices can autoload using the existing mechanism using IFLA_INFO_KIND. However, there's no mechanism that lwt modules not using net devices can use. Therefore, add the ability to autoload modules registering lwt operations for lwt implementations not using a net device so that users don't have to manually load the modules. Only users with the CAP_NET_ADMIN capability can cause modules to be loaded, which is ensured by rtnetlink_rcv_msg rejecting non-RTM_GETxxx messages for users without this capability, and by lwtunnel_build_state not being called in response to RTM_GETxxx messages. Signed-off-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08dst: Pass net into dst->outputEric W. Biederman1-2/+2
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>
2015-08-24lwt: Add cfg argument to build_stateTom Herbert1-2/+3
Add cfg and family arguments to lwt build state functions. cfg is a void pointer and will either be a pointer to a fib_config or fib6_config structure. The family parameter indicates which one (either AF_INET or AF_INET6). LWT encpasulation implementation may use the fib configuration to build the LWT state. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-20route: move lwtunnel state to dst_entryJiri Benc1-60/+10
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>
2015-08-17lwt: Add support to redirect dst.inputTom Herbert1-0/+55
This patch adds the capability to redirect dst input in the same way that dst output is redirected by LWT. Also, save the original dst.input and and dst.out when setting up lwtunnel redirection. These can be called by the client as a pass- through. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-03lwtunnel: set skb protocol and devRobert Shearman1-2/+10
In the locally-generated packet path skb->protocol may not be set and this is required for the lwtunnel encap in order to get the lwtstate. This would otherwise have been set by ip_output or ip6_output so set skb->protocol prior to calling the lwtunnel encap function. Additionally set skb->dev in case it is needed further down the transmit path. Signed-off-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-29lwtunnel: Make lwtun_encaps[] staticThomas Graf1-1/+1
Any external user should use the registration API instead of accessing this directly. Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27lwtunnel: use kfree_skb() instead of vanilla kfree()Dan Carpenter1-1/+1
kfree_skb() is correct here. Fixes: ffce41962ef6 ('lwtunnel: support dst output redirect function') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21lwtunnel: support dst output redirect functionRoopa Prabhu1-0/+56
This patch introduces lwtunnel_output function to call corresponding lwtunnels output function to xmit the packet. It adds two variants lwtunnel_output and lwtunnel_output6 for ipv4 and ipv6 respectively today. But this is subject to change when lwtstate will reside in dst or dst_metadata (as per upstream discussions). Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21lwtunnel: infrastructure for handling light weight tunnels like mplsRoopa Prabhu1-0/+179
Provides infrastructure to parse/dump/store encap information for light weight tunnels like mpls. Encap information for such tunnels is associated with fib routes. This infrastructure is based on previous suggestions from Eric Biederman to follow the xfrm infrastructure. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>