user/sven/linux.git/kernel/bpf/devmap.c, branch v4.20.15

bpf: devmap: fix wrong interface selection in notifier_call

2018-10-25T22:32:21Z

The dev_map_notification() removes interface in devmap if unregistering interface's ifindex is same. But only checking ifindex is not enough because other netns can have same ifindex. so that wrong interface selection could occurred. Hence netdev pointer comparison code is added. v2: compare netdev pointer instead of using net_eq() (Daniel Borkmann) v1: Initial patch Fixes: 2ddf71e23cc2 ("net: add notifier hooks for devmap bpf map") Signed-off-by: Taehee Yoo Acked-by: Song Liu Signed-off-by: Daniel Borkmann

bpf: fix redirect to map under tail calls

2018-08-17T22:56:23Z

Commits 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") and 7c3001313396 ("bpf: fix ri->map_owner pointer on bpf_prog_realloc") tried to mitigate that buggy programs using bpf_redirect_map() helper call do not leave stale maps behind. Idea was to add a map_owner cookie into the per CPU struct redirect_info which was set to prog->aux by the prog making the helper call as a proof that the map is not stale since the prog is implicitly holding a reference to it. This owner cookie could later on get compared with the program calling into BPF whether they match and therefore the redirect could proceed with processing the map safely. In (obvious) hindsight, this approach breaks down when tail calls are involved since the original caller's prog->aux pointer does not have to match the one from one of the progs out of the tail call chain, and therefore the xdp buffer will be dropped instead of redirected. A way around that would be to fix the issue differently (which also allows to remove related work in fast path at the same time): once the life-time of a redirect map has come to its end we use it's map free callback where we need to wait on synchronize_rcu() for current outstanding xdp buffers and remove such a map pointer from the redirect info if found to be present. At that time no program is using this map anymore so we simply invalidate the map pointers to NULL iff they previously pointed to that instance while making sure that the redirect path only reads out the map once. Fixes: 97f91a7cf04f ("bpf: add bpf_redirect_map helper routine") Fixes: 109980b894e9 ("bpf: don't select potentially stale ri->map from buggy xdp progs") Reported-by: Sebastiano Miano Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Signed-off-by: Alexei Starovoitov

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2018-08-13T17:07:23Z

Daniel Borkmann says: ==================== pull-request: bpf-next 2018-08-13 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add driver XDP support for veth. This can be used in conjunction with redirect of another XDP program e.g. sitting on NIC so the xdp_frame can be forwarded to the peer veth directly without modification, from Toshiaki. 2) Add a new BPF map type REUSEPORT_SOCKARRAY and prog type SK_REUSEPORT in order to provide more control and visibility on where a SO_REUSEPORT sk should be located, and the latter enables to directly select a sk from the bpf map. This also enables map-in-map for application migration use cases, from Martin. 3) Add a new BPF helper bpf_skb_ancestor_cgroup_id() that returns the id of cgroup v2 that is the ancestor of the cgroup associated with the skb at the ancestor_level, from Andrey. 4) Implement BPF fs map pretty-print support based on BTF data for regular hash table and LRU map, from Yonghong. 5) Decouple the ability to attach BTF for a map from the key and value pretty-printer in BPF fs, and enable further support of BTF for maps for percpu and LPM trie, from Daniel. 6) Implement a better BPF sample of using XDP's CPU redirect feature for load balancing SKB processing to remote CPU. The sample implements the same XDP load balancing as Suricata does which is symmetric hash based on IP and L4 protocol, from Jesper. 7) Revert adding NULL pointer check with WARN_ON_ONCE() in __xdp_return()'s critical path as it is ensured that the allocator is present, from Björn. ==================== Signed-off-by: David S. Miller

bpf: decouple btf from seq bpf fs dump and enable more maps

2018-08-12T22:52:45Z

Commit a26ca7c982cb ("bpf: btf: Add pretty print support to the basic arraymap") and 699c86d6ec21 ("bpf: btf: add pretty print for hash/lru_hash maps") enabled support for BTF and dumping via BPF fs for array and hash/lru map. However, both can be decoupled from each other such that regular BPF maps can be supported for attaching BTF key/value information, while not all maps necessarily need to dump via map_seq_show_elem() callback. The basic sanity check which is a prerequisite for all maps is that key/value size has to match in any case, and some maps can have extra checks via map_check_btf() callback, e.g. probing certain types or indicating no support in general. With that we can also enable retrieving BTF info for per-cpu map types and lpm. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Acked-by: Yonghong Song

xdp: fix bug in devmap teardown code path

2018-08-09T19:50:44Z

Like cpumap teardown, the devmap teardown code also flush remaining xdp_frames, via bq_xmit_all() in case map entry is removed. The code can call xdp_return_frame_rx_napi, from the the wrong context, in-case ndo_xdp_xmit() fails. Fixes: 389ab7f01af9 ("xdp: introduce xdp_return_frame_rx_napi") Fixes: 735fc4054b3a ("xdp: change ndo_xdp_xmit API to support bulking") Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann

xdp: XDP_REDIRECT should check IFF_UP and MTU

2018-07-07T22:25:35Z

Otherwise we end up with attempting to send packets from down devices or to send oversized packets, which may cause unexpected driver/device behaviour. Generic XDP has already done this check, so reuse the logic in native XDP. Fixes: 814abfabef3c ("xdp: add bpf_redirect helper function") Signed-off-by: Toshiaki Makita Signed-off-by: Alexei Starovoitov

xdp: Fix handling of devmap in generic XDP

2018-06-15T21:47:15Z

Commit 67f29e07e131 ("bpf: devmap introduce dev_map_enqueue") changed the return value type of __devmap_lookup_elem() from struct net_device * to struct bpf_dtab_netdev * but forgot to modify generic XDP code accordingly. Thus generic XDP incorrectly used struct bpf_dtab_netdev where struct net_device is expected, then skb->dev was set to invalid value. v2: - Fix compiler warning without CONFIG_BPF_SYSCALL. Fixes: 67f29e07e131 ("bpf: devmap introduce dev_map_enqueue") Signed-off-by: Toshiaki Makita Acked-by: Yonghong Song Acked-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann

bpf/xdp: devmap can avoid calling ndo_xdp_flush

2018-06-03T15:11:35Z

The XDP_REDIRECT map devmap can avoid using ndo_xdp_flush, by instead instructing ndo_xdp_xmit to flush via XDP_XMIT_FLUSH flag in appropriate places. Notice after this patch it is possible to remove ndo_xdp_flush completely, as this is the last user of ndo_xdp_flush. This is left for later patches, to keep driver changes separate. Signed-off-by: Jesper Dangaard Brouer Acked-by: Song Liu Signed-off-by: Alexei Starovoitov

xdp: add flags argument to ndo_xdp_xmit API

2018-06-03T15:11:34Z

This patch only change the API and reject any use of flags. This is an intermediate step that allows us to implement the flush flag operation later, for each individual driver in a separate patch. The plan is to implement flush operation via XDP_XMIT_FLUSH flag and then remove XDP_XMIT_FLAGS_NONE when done. Signed-off-by: Jesper Dangaard Brouer Acked-by: Song Liu Signed-off-by: Alexei Starovoitov

bpf: devmap: remove redundant assignment of dev = dev

2018-05-30T21:02:48Z

The assignment dev = dev is redundant and should be removed. Detected by CoverityScan, CID#1469486 ("Evaluation order violation") Signed-off-by: Colin Ian King Acked-by: Song Liu Signed-off-by: Alexei Starovoitov