kernel/linux.git/tools/lib/bpf/netlink.c, branch v6.12.80

bpftool: Fix truncated netlink dumps

2026-03-04T12:20:38+00:00

[ Upstream commit 3b39d73cc3379360a33eb583b17f21fe55e1288e ] Netlink requires that the recv buffer used during dumps is at least min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will get truncated. Make sure bpftool follows this requirement, avoid missing information on systems with large pages. Acked-by: Quentin Monnet Fixes: 7084566a236f ("tools/bpftool: Remove libbpf_internal.h usage in bpftool") Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Use OPTS_SET() macro in bpf_xdp_query()

2024-02-06T17:51:26+00:00

When the feature_flags and xdp_zc_max_segs fields were added to the libbpf bpf_xdp_query_opts, the code writing them did not use the OPTS_SET() macro. This causes libbpf to write to those fields unconditionally, which means that programs compiled against an older version of libbpf (with a smaller size of the bpf_xdp_query_opts struct) will have its stack corrupted by libbpf writing out of bounds. The patch adding the feature_flags field has an early bail out if the feature_flags field is not part of the opts struct (via the OPTS_HAS) macro, but the patch adding xdp_zc_max_segs does not. For consistency, this fix just changes the assignments to both fields to use the OPTS_SET() macro. Fixes: 13ce2daa259a ("xsk: add new netlink attribute dedicated for ZC max frags") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240206125922.1992815-1-toke@redhat.com

xsk: add new netlink attribute dedicated for ZC max frags

2023-07-19T16:56:49+00:00

Introduce new netlink attribute NETDEV_A_DEV_XDP_ZC_MAX_SEGS that will carry maximum fragments that underlying ZC driver is able to handle on TX side. It is going to be included in netlink response only when driver supports ZC. Any value higher than 1 implies multi-buffer ZC support on underlying device. Signed-off-by: Maciej Fijalkowski Link: https://lore.kernel.org/r/20230719132421.584801-11-maciej.fijalkowski@intel.com Signed-off-by: Alexei Starovoitov

libbpf: Fix bpf_xdp_query() in old kernels

2023-02-27T23:26:12+00:00

Commit 04d58f1b26a4("libbpf: add API to get XDP/XSK supported features") added feature_flags to struct bpf_xdp_query_opts. If a user uses bpf_xdp_query_opts with feature_flags member, the bpf_xdp_query() will check whether 'netdev' family exists or not in the kernel. If it does not exist, the bpf_xdp_query() will return -ENOENT. But 'netdev' family does not exist in old kernels as it is introduced in the same patch set as Commit 04d58f1b26a4. So old kernel with newer libbpf won't work properly with bpf_xdp_query() api call. To fix this issue, if the return value of libbpf_netlink_resolve_genl_family_id() is -ENOENT, bpf_xdp_query() will just return 0, skipping the rest of xdp feature query. This preserves backward compatibility. Fixes: 04d58f1b26a4 ("libbpf: add API to get XDP/XSK supported features") Signed-off-by: Yonghong Song Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230227224943.1153459-1-yhs@fb.com

libbpf: Use bpf_{btf,link,map,prog}_get_info_by_fd()

2023-02-16T23:32:45+00:00

Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230214231221.249277-3-iii@linux.ibm.com

libbpf: Always use libbpf_err to return an error in bpf_xdp_query()

2023-02-07T21:56:11+00:00

In order to properly set errno, rely on libbpf_err utility routine in bpf_xdp_query() to return an error to the caller. Fixes: 04d58f1b26a4 ("libbpf: add API to get XDP/XSK supported features") Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/827d40181f9f90fb37702f44328e1614df7c0503.1675768112.git.lorenzo@kernel.org

libbpf: add API to get XDP/XSK supported features

2023-02-03T04:48:24+00:00

Extend bpf_xdp_query routine in order to get XDP/XSK supported features of netdev over route netlink interface. Extend libbpf netlink implementation in order to support netlink_generic protocol. Co-developed-by: Kumar Kartikeya Dwivedi Signed-off-by: Kumar Kartikeya Dwivedi Co-developed-by: Marek Majtyka Signed-off-by: Marek Majtyka Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/a72609ef4f0de7fee5376c40dbf54ad7f13bfb8d.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: add the capability to specify netlink proto in libbpf_netlink_send_recv

2023-02-03T04:48:23+00:00

This is a preliminary patch in order to introduce netlink_generic protocol support to libbpf. Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/7878a54667e74afeec3ee519999c044bd514b44c.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Streamline bpf_attr and perf_event_attr initialization

2022-08-17T20:42:10+00:00

Make sure that entire libbpf code base is initializing bpf_attr and perf_event_attr with memset(0). Also for bpf_attr make sure we clear and pass to kernel only relevant parts of bpf_attr. bpf_attr is a huge union of independent sub-command attributes, so there is no need to clear and pass entire union bpf_attr, which over time grows quite a lot and for most commands this growth is completely irrelevant. Few cases where we were relying on compiler initialization of BPF UAPI structs (like bpf_prog_info, bpf_map_info, etc) with `= {};` were switched to memset(0) pattern for future-proofing. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Hao Luo Link: https://lore.kernel.org/bpf/20220816001929.369487-3-andrii@kernel.org

libbpf: remove deprecated XDP APIs

2022-06-28T20:13:32+00:00

Get rid of deprecated bpf_set_link*() and bpf_get_link*() APIs. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220627211527.2245459-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov