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path: root/net/sched/cls_bpf.c
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2018-05-24net_sched: switch to rcu_workCong Wang
Commit 05f0fe6b74db ("RCU, workqueue: Implement rcu_work") introduces new API's for dispatching work in a RCU callback. Now we can just switch to the new API's for tc filters. This could get rid of a lot of code. Cc: Tejun Heo <tj@kernel.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-06cls_bpf: Convert to use idr_alloc_u32Matthew Wilcox
Use the new helper. This has a modest reduction in both lines of code and compiled code size. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Delete idr_replace_ext functionMatthew Wilcox
Changing idr_replace's 'id' argument to 'unsigned long' works for all callers. Callers which passed a negative ID now get -ENOENT instead of -EINVAL. No callers relied on this error value. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Delete idr_remove_ext functionMatthew Wilcox
Simply changing idr_remove's 'id' argument to 'unsigned long' suffices for all callers. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-01-24cls_bpf: propagate extack to offload delete callbackJakub Kicinski
Propagate extack on removal of offloaded filter. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24cls_bpf: pass offload flags to tc_cls_common_offload_init()Jakub Kicinski
Pass offload flags to the new implementation of tc_cls_common_offload_init(). Extack will now only be set if user requested skip_sw. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24cls_bpf: remove gen_flags from bpf_offloadJakub Kicinski
cls_bpf now guarantees that only device-bound programs are allowed with skip_sw. The drivers no longer pay attention to flags on filter load, therefore the bpf_offload member can be removed. If flags are needed again they should probably be added to struct tc_cls_common_offload instead. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24net: sched: prepare for reimplementation of tc_cls_common_offload_init()Jakub Kicinski
Rename the tc_cls_common_offload_init() helper function to tc_cls_common_offload_init_deprecated() and add a new implementation which also takes flags argument. We will only set extack if flags indicate that offload is forced (skip_sw) otherwise driver errors should be ignored, as they don't influence the overall filter installation. Note that we need the tc_skip_hw() helper for new version, therefore it is added later in the file. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-24net: sched: propagate extack to cls->destroy callbacksJakub Kicinski
Propagate extack to cls->destroy callbacks when called from non-error paths. On error paths pass NULL to avoid overwriting the failure message. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-22net: sched: add extack support for offload via tc_cls_common_offloadQuentin Monnet
Add extack support for hardware offload of classifiers. In order to achieve this, a pointer to a struct netlink_ext_ack is added to the struct tc_cls_common_offload that is passed to the callback for setting up the classifier. Function tc_cls_common_offload_init() is updated to support initialization of this new attribute. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-22net: sched: cls_bpf: plumb extack support in filter for hardware offloadQuentin Monnet
Pass the extack pointer obtained in the `->change()` filter operation to cls_bpf_offload() and then to cls_bpf_offload_cmd(). This makes it possible to use this extack pointer in drivers offloading BPF programs in a future patch. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The BPF verifier conflict was some minor contextual issue. The TUN conflict was less trivial. Cong Wang fixed a memory leak of tfile->tx_array in 'net'. This is an skb_array. But meanwhile in net-next tun changed tfile->tx_arry into tfile->tx_ring which is a ptr_ring. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19net: sched: cls: add extack support for delete callbackAlexander Aring
This patch adds extack support for classifier delete callback api. This prepares to handle extack support inside each specific classifier implementation. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19net: sched: cls: add extack support for tcf_exts_validateAlexander Aring
The tcf_exts_validate function calls the act api change callback. For preparing extack support for act api, this patch adds the extack as parameter for this function which is common used in cls implementations. Furthermore the tcf_exts_validate will call action init callback which prepares the TC action subsystem for extack support. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19net: sched: cls: add extack support for change callbackAlexander Aring
This patch adds extack support for classifier change callback api. This prepares to handle extack support inside each specific classifier implementation. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17bpf: fix cls_bpf on filter replaceDaniel Borkmann
Running the following sequence is currently broken: # tc qdisc add dev foo clsact # tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o # tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o RTNETLINK answers: Invalid argument The normal expectation on kernel side is that the second command succeeds replacing the existing program. However, what happens is in cls_bpf_change(), we bail out with err in the second run in cls_bpf_offload(). The EINVAL comes directly in cls_bpf_offload() when comparing prog vs oldprog's gen_flags. In case of above replace the new prog's gen_flags are 0, but the old ones are 8, which means TCA_CLS_FLAGS_NOT_IN_HW is set (e.g. drivers not having cls_bpf offload). Fix 102740bd9436 ("cls_bpf: fix offload assumptions after callback conversion") in the following way: gen_flags from user space passed down via netlink cannot include status flags like TCA_CLS_FLAGS_IN_HW or TCA_CLS_FLAGS_NOT_IN_HW as opposed to oldprog that we previously loaded. Therefore, it doesn't make any sense to include them in the gen_flags comparison with the new prog before we even attempt to offload. Thus, lets fix this before 4.15 goes out. Fixes: 102740bd9436 ("cls_bpf: fix offload assumptions after callback conversion") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: sched: keep track of offloaded filters and check tc offload featureJiri Pirko
During block bind, we need to check tc offload feature. If it is disabled yet still the block contains offloaded filters, forbid the bind. Also forbid to register callback for a block that already contains offloaded filters, as the play back is not supported now. For keeping track of offloaded filters there is a new counter introduced, alongside with couple of helpers called from cls_* code. These helpers set and clear TCA_CLS_FLAGS_IN_HW flag. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17net: sched: introduce block mechanism to handle netif_keep_dst callsJiri Pirko
Couple of classifiers call netif_keep_dst directly on q->dev. That is not possible to do directly for shared blocke where multiple qdiscs are owning the block. So introduce a infrastructure to keep track of the block owners in list and use this list to implement block variant of netif_keep_dst. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-20cls_bpf: fix offload assumptions after callback conversionJakub Kicinski
cls_bpf used to take care of tracking what offload state a filter is in, i.e. it would track if offload request succeeded or not. This information would then be used to issue correct requests to the driver, e.g. requests for statistics only on offloaded filters, removing only filters which were offloaded, using add instead of replace if previous filter was not added etc. This tracking of offload state no longer functions with the new callback infrastructure. There could be multiple entities trying to offload the same filter. Throw out all the tracking and corresponding commands and simply pass to the drivers both old and new bpf program. Drivers will have to deal with offload state tracking by themselves. Fixes: 3f7889c4c79b ("net: sched: cls_bpf: call block callbacks for offload") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-28cls_bpf: don't decrement net's refcount when offload failsJakub Kicinski
When cls_bpf offload was added it seemed like a good idea to call cls_bpf_delete_prog() instead of extending the error handling path, since the software state is fully initialized at that point. This handling of errors without jumping to the end of the function is error prone, as proven by later commit missing that extra call to __cls_bpf_delete_prog(). __cls_bpf_delete_prog() is now expected to be invoked with a reference on exts->net or the field zeroed out. The call on the offload's error patch does not fullfil this requirement, leading to each error stealing a reference on net namespace. Create a function undoing what cls_bpf_set_parms() did and use it from __cls_bpf_delete_prog() and the error path. Fixes: aae2c35ec892 ("cls_bpf: use tcf_exts_get_net() before call_rcu()") Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-21bpf: offload: move offload device validation out to the driversJakub Kicinski
With TC shared block changes we can't depend on correct netdev pointer being available in cls_bpf. Move the device validation to the driver. Core will only make sure that offloaded programs are always attached in the driver (or in HW by the driver). We trust that drivers which implement offload callbacks will perform necessary checks. Moving the checks to the driver is generally a useful thing, in practice the check should be against a switchdev instance, not a netdev, given that most ASICs will probably allow using the same program on many ports. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-11-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Simple cases of overlapping changes in the packet scheduler. Must easier to resolve this time. Which probably means that I screwed it up somehow. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-09cls_bpf: use tcf_exts_get_net() before call_rcu()Cong Wang
Hold netns refcnt before call_rcu() and release it after the tcf_exts_destroy() is done. Note, on ->destroy() path we have to respect the return value of tcf_exts_get_net(), on other paths it should always return true, so we don't need to care. Cc: Lucas Bates <lucasb@mojatatu.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05cls_bpf: allow attaching programs loaded for specific deviceJakub Kicinski
If TC program is loaded with skip_sw flag, we should allow the device-specific programs to be accepted. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-03net: sched: cls_bpf: use bitwise & rather than logical && on gen_flagsColin Ian King
Currently gen_flags is being operated on by a logical && operator rather than a bitwise & operator. This looks incorrect as these should be bit flag operations. Fix this. Detected by CoverityScan, CID#1460305 ("Logical vs. bitwise operator") Fixes: 3f7889c4c79b ("net: sched: cls_bpf: call block callbacks for offload) Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Several conflicts here. NFP driver bug fix adding nfp_netdev_is_nfp_repr() check to nfp_fl_output() needed some adjustments because the code block is in an else block now. Parallel additions to net/pkt_cls.h and net/sch_generic.h A bug fix in __tcp_retransmit_skb() conflicted with some of the rbtree changes in net-next. The tc action RCU callback fixes in 'net' had some overlap with some of the recent tcf_block reworking. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29net_sched: use tcf_queue_work() in bpf filterCong Wang
Defer the tcf_exts_destroy() in RCU callback to tc filter workqueue and get RTNL lock. Reported-by: Chris Mi <chrism@mellanox.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Pirko <jiri@resnulli.us> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-21net: sched: avoid ndo_setup_tc calls for TC_SETUP_CLS*Jiri Pirko
All drivers are converted to use block callbacks for TC_SETUP_CLS*. So it is now safe to remove the calls to ndo_setup_tc from cls_* Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-21net: sched: cls_bpf: call block callbacks for offloadJiri Pirko
Use the newly introduced callbacks infrastructure and call block callbacks alongside with the existing per-netdev ndo_setup_tc. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-28net_sched: use idr to allocate bpf filter handlesCong Wang
Instead of calling cls_bpf_get() in a loop to find a unused handle, just switch to idr API to allocate new handles. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Chris Mi <chrism@mellanox.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-26bpf: rename bpf_compute_data_end into bpf_compute_data_pointersDaniel Borkmann
Just do the rename into bpf_compute_data_pointers() as we'll add one more pointer here to recompute. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-31net_sched: add reverse binding for tc classCong Wang
TC filters when used as classifiers are bound to TC classes. However, there is a hidden difference when adding them in different orders: 1. If we add tc classes before its filters, everything is fine. Logically, the classes exist before we specify their ID's in filters, it is easy to bind them together, just as in the current code base. 2. If we add tc filters before the tc classes they bind, we have to do dynamic lookup in fast path. What's worse, this happens all the time not just once, because on fast path tcf_result is passed on stack, there is no way to propagate back to the one in tc filters. This hidden difference hurts performance silently if we have many tc classes in hierarchy. This patch intends to close this gap by doing the reverse binding when we create a new class, in this case we can actually search all the filters in its parent, match and fixup by classid. And because tcf_result is specific to each type of tc filter, we have to introduce a new ops for each filter to tell how to bind the class. Note, we still can NOT totally get rid of those class lookup in ->enqueue() because cgroup and flow filters have no way to determine the classid at setup time, they still have to go through dynamic lookup. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-11net: sched: remove cops->tcf_cl_offloadJiri Pirko
cops->tcf_cl_offload is no longer needed, as the drivers check what they can and cannot offload using the classid identify helpers. So remove this. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07net_sched: use void pointer for filter handleWANG Cong
Now we use 'unsigned long fh' as a pointer in every place, it is safe to convert it to a void pointer now. This gets rid of many casts to pointer. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07net: sched: get rid of struct tc_to_netdevJiri Pirko
Get rid of struct tc_to_netdev which is now just unnecessary container and rather pass per-type structures down to drivers directly. Along with that, consolidate the naming of per-type structure variables in cls_*. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07net: sched: push cls related args into cls_common structureJiri Pirko
As ndo_setup_tc is generic offload op for whole tc subsystem, does not really make sense to have cls-specific args. So move them under cls_common structurure which is embedded in all cls structs. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07net: sched: make type an argument for ndo_setup_tcJiri Pirko
Since the type is always present, push it to be a separate argument to ndo_setup_tc. On the way, name the type enum and use it for arg type. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_bpf: no need to call tcf_exts_change for newly allocated structJiri Pirko
As the prog struct was allocated right before cls_bpf_set_parms call, no need to use tcf_exts_change to do atomic change, and we can just fill-up the unused exts struct directly by tcf_exts_validate. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04net: sched: cls_bpf: rename cls_bpf_modify_existing functionJiri Pirko
The name cls_bpf_modify_existing is highly misleading, as it indeed does not modify anything existing. It does not modify at all. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21bpf: expose prog id for cls_bpf and act_bpfDaniel Borkmann
In order to be able to retrieve the attached programs from cls_bpf and act_bpf, we need to expose the prog ids via netlink so that an application can later on get an fd based on the id through the BPF_PROG_GET_FD_BY_ID command, and dump related prog info via BPF_OBJ_GET_INFO_BY_FD command for bpf(2). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08net: propagate tc filter chain index down the ndo_setup_tc callJiri Pirko
We need to push the chain index down to the drivers, so they have the information to which chain the rule belongs. For now, no driver supports multichain offload, so only chain 0 is supported. This is needed to prevent chain squashes during offload for now. Later this will be used to implement multichain offload. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-06net: sched: introduce a TRAP control actionJiri Pirko
There is need to instruct the HW offloaded path to push certain matched packets to cpu/kernel for further analysis. So this patch introduces a new TRAP control action to TC. For kernel datapath, this action does not make much sense. So with the same logic as in HW, new TRAP behaves similar to STOLEN. The skb is just dropped in the datapath (and virtually ejected to an upper level, which does not exist in case of kernel). Signed-off-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Yotam Gigi <yotamg@mellanox.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-21net_sched: move the empty tp check from ->destroy() to ->delete()WANG Cong
We could have a race condition where in ->classify() path we dereference tp->root and meanwhile a parallel ->destroy() makes it a NULL. Daniel cured this bug in commit d936377414fa ("net, sched: respect rcu grace period on cls destruction"). This happens when ->destroy() is called for deleting a filter to check if we are the last one in tp, this tp is still linked and visible at that time. The root cause of this problem is the semantic of ->destroy(), it does two things (for non-force case): 1) check if tp is empty 2) if tp is empty we could really destroy it and its caller, if cares, needs to check its return value to see if it is really destroyed. Therefore we can't unlink tp unless we know it is empty. As suggested by Daniel, we could actually move the test logic to ->delete() so that we can safely unlink tp after ->delete() tells us the last one is just deleted and before ->destroy(). Fixes: 1e052be69d04 ("net_sched: destroy proto tp when all filters are gone") Cc: Roi Dayan <roid@mellanox.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-17net/sched: cls_bpf: Reflect HW offload statusOr Gerlitz
BPF classifier support for the "in hw" offloading flags. Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Amir Vadai <amir@vadai.me> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-16bpf: rework prog_digest into prog_tagDaniel Borkmann
Commit 7bd509e311f4 ("bpf: add prog_digest and expose it via fdinfo/netlink") was recently discussed, partially due to admittedly suboptimal name of "prog_digest" in combination with sha1 hash usage, thus inevitably and rightfully concerns about its security in terms of collision resistance were raised with regards to use-cases. The intended use cases are for debugging resp. introspection only for providing a stable "tag" over the instruction sequence that both kernel and user space can calculate independently. It's not usable at all for making a security relevant decision. So collisions where two different instruction sequences generate the same tag can happen, but ideally at a rather low rate. The "tag" will be dumped in hex and is short enough to introspect in tracepoints or kallsyms output along with other data such as stack trace, etc. Thus, this patch performs a rename into prog_tag and truncates the tag to a short output (64 bits) to make it obvious it's not collision-free. Should in future a hash or facility be needed with a security relevant focus, then we can think about requirements, constraints, etc that would fit to that situation. For now, rework the exposed parts for the current use cases as long as nothing has been released yet. Tested on x86_64 and s390x. Fixes: 7bd509e311f4 ("bpf: add prog_digest and expose it via fdinfo/netlink") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05bpf: add prog_digest and expose it via fdinfo/netlinkDaniel Borkmann
When loading a BPF program via bpf(2), calculate the digest over the program's instruction stream and store it in struct bpf_prog's digest member. This is done at a point in time before any instructions are rewritten by the verifier. Any unstable map file descriptor number part of the imm field will be zeroed for the hash. fdinfo example output for progs: # cat /proc/1590/fdinfo/5 pos: 0 flags: 02000002 mnt_id: 11 prog_type: 1 prog_jited: 1 prog_digest: b27e8b06da22707513aa97363dfb11c7c3675d28 memlock: 4096 When programs are pinned and retrieved by an ELF loader, the loader can check the program's digest through fdinfo and compare it against one that was generated over the ELF file's program section to see if the program needs to be reloaded. Furthermore, this can also be exposed through other means such as netlink in case of a tc cls/act dump (or xdp in future), but also through tracepoints or other facilities to identify the program. Other than that, the digest can also serve as a base name for the work in progress kallsyms support of programs. The digest doesn't depend/select the crypto layer, since we need to keep dependencies to a minimum. iproute2 will get support for this facility. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05bpf, cls: consolidate prog deletion pathDaniel Borkmann
Commit 18cdb37ebf4c ("net: sched: do not use tcf_proto 'tp' argument from call_rcu") removed the last usage of tp from cls_bpf_delete_prog(), so also remove it from the function as argument to not give a wrong impression. tp is illegal to access from this callback, since it could already have been freed. Refactor the deletion code a bit, so that cls_bpf_destroy() can call into the same code for prog deletion as cls_bpf_delete() op, instead of having it unnecessarily duplicated. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Couple conflicts resolved here: 1) In the MACB driver, a bug fix to properly initialize the RX tail pointer properly overlapped with some changes to support variable sized rings. 2) In XGBE we had a "CONFIG_PM" --> "CONFIG_PM_SLEEP" fix overlapping with a reorganization of the driver to support ACPI, OF, as well as PCI variants of the chip. 3) In 'net' we had several probe error path bug fixes to the stmmac driver, meanwhile a lot of this code was cleaned up and reorganized in 'net-next'. 4) The cls_flower classifier obtained a helper function in 'net-next' called __fl_delete() and this overlapped with Daniel Borkamann's bug fix to use RCU for object destruction in 'net'. It also overlapped with Jiri's change to guard the rhashtable_remove_fast() call with a check against tc_skip_sw(). 5) In mlx4, a revert bug fix in 'net' overlapped with some unrelated changes in 'net-next'. 6) In geneve, a stale header pointer after pskb_expand_head() bug fix in 'net' overlapped with a large reorganization of the same code in 'net-next'. Since the 'net-next' code no longer had the bug in question, there was nothing to do other than to simply take the 'net-next' hunks. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-28net, sched: respect rcu grace period on cls destructionDaniel Borkmann
Roi reported a crash in flower where tp->root was NULL in ->classify() callbacks. Reason is that in ->destroy() tp->root is set to NULL via RCU_INIT_POINTER(). It's problematic for some of the classifiers, because this doesn't respect RCU grace period for them, and as a result, still outstanding readers from tc_classify() will try to blindly dereference a NULL tp->root. The tp->root object is strictly private to the classifier implementation and holds internal data the core such as tc_ctl_tfilter() doesn't know about. Within some classifiers, such as cls_bpf, cls_basic, etc, tp->root is only checked for NULL in ->get() callback, but nowhere else. This is misleading and seemed to be copied from old classifier code that was not cleaned up properly. For example, d3fa76ee6b4a ("[NET_SCHED]: cls_basic: fix NULL pointer dereference") moved tp->root initialization into ->init() routine, where before it was part of ->change(), so ->get() had to deal with tp->root being NULL back then, so that was indeed a valid case, after d3fa76ee6b4a, not really anymore. We used to set tp->root to NULL long ago in ->destroy(), see 47a1a1d4be29 ("pkt_sched: remove unnecessary xchg() in packet classifiers"); but the NULLifying was reintroduced with the RCUification, but it's not correct for every classifier implementation. In the cases that are fixed here with one exception of cls_cgroup, tp->root object is allocated and initialized inside ->init() callback, which is always performed at a point in time after we allocate a new tp, which means tp and thus tp->root was not globally visible in the tp chain yet (see tc_ctl_tfilter()). Also, on destruction tp->root is strictly kfree_rcu()'ed in ->destroy() handler, same for the tp which is kfree_rcu()'ed right when we return from ->destroy() in tcf_destroy(). This means, the head object's lifetime for such classifiers is always tied to the tp lifetime. The RCU callback invocation for the two kfree_rcu() could be out of order, but that's fine since both are independent. Dropping the RCU_INIT_POINTER(tp->root, NULL) for these classifiers here means that 1) we don't need a useless NULL check in fast-path and, 2) that outstanding readers of that tp in tc_classify() can still execute under respect with RCU grace period as it is actually expected. Things that haven't been touched here: cls_fw and cls_route. They each handle tp->root being NULL in ->classify() path for historic reasons, so their ->destroy() implementation can stay as is. If someone actually cares, they could get cleaned up at some point to avoid the test in fast path. cls_u32 doesn't set tp->root to NULL. For cls_rsvp, I just added a !head should anyone actually be using/testing it, so it at least aligns with cls_fw and cls_route. For cls_flower we additionally need to defer rhashtable destruction (to a sleepable context) after RCU grace period as concurrent readers might still access it. (Note that in this case we need to hold module reference to keep work callback address intact, since we only wait on module unload for all call_rcu()s to finish.) This fixes one race to bring RCU grace period guarantees back. Next step as worked on by Cong however is to fix 1e052be69d04 ("net_sched: destroy proto tp when all filters are gone") to get the order of unlinking the tp in tc_ctl_tfilter() for the RTM_DELTFILTER case right by moving RCU_INIT_POINTER() before tcf_destroy() and let the notification for removal be done through the prior ->delete() callback. Both are independant issues. Once we have that right, we can then clean tp->root up for a number of classifiers by not making them RCU pointers, which requires a new callback (->uninit) that is triggered from tp's RCU callback, where we just kfree() tp->root from there. Fixes: 1f947bf151e9 ("net: sched: rcu'ify cls_bpf") Fixes: 9888faefe132 ("net: sched: cls_basic use RCU") Fixes: 70da9f0bf999 ("net: sched: cls_flow use RCU") Fixes: 77b9900ef53a ("tc: introduce Flower classifier") Fixes: bf3994d2ed31 ("net/sched: introduce Match-all classifier") Fixes: 952313bd6258 ("net: sched: cls_cgroup use RCU") Reported-by: Roi Dayan <roid@mellanox.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Roi Dayan <roid@mellanox.com> Cc: Jiri Pirko <jiri@mellanox.com> Acked-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>