linux.git/tools/lib/bpf/netlink.c, branch v6.6

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

libbpf: Fix memleak in libbpf_netlink_recv()

2022-02-17T15:09:07+00:00

Ensure that libbpf_netlink_recv() frees dynamically allocated buffer in
all code paths.

Fixes: 9c3de619e13e ("libbpf: Use dynamically allocated buffer when receiving netlink messages")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Toke Høiland-Jørgensen 
Link: https://lore.kernel.org/bpf/20220217073958.276959-1-andrii@kernel.org

libbpf: Use dynamically allocated buffer when receiving netlink messages

2022-02-12T15:57:44+00:00

When receiving netlink messages, libbpf was using a statically allocated
stack buffer of 4k bytes. This happened to work fine on systems with a 4k
page size, but on systems with larger page sizes it can lead to truncated
messages. The user-visible impact of this was that libbpf would insist no
XDP program was attached to some interfaces because that bit of the netlink
message got chopped off.

Fix this by switching to a dynamically allocated buffer; we borrow the
approach from iproute2 of using recvmsg() with MSG_PEEK|MSG_TRUNC to get
the actual size of the pending message before receiving it, adjusting the
buffer as necessary. While we're at it, also add retries on interrupted
system calls around the recvmsg() call.

v2:
  - Move peek logic to libbpf_netlink_recv(), don't double free on ENOMEM.

Fixes: 8bbb77b7c7a2 ("libbpf: Add various netlink helpers")
Reported-by: Zhiqian Guan 
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Andrii Nakryiko 
Acked-by: Kumar Kartikeya Dwivedi 
Link: https://lore.kernel.org/bpf/20220211234819.612288-1-toke@redhat.com