mirror of
https://github.com/xdp-project/bpf-examples.git
synced 2024-05-06 15:54:53 +00:00
0306ff7cca
The type of the net->net_cookie field member was changed in kernel 5.12
with commit 3d368ab87cf6 ("net: initialize net->net_cookie at netns setup").
Older versions of the kernel devices net->net_cookie as an atomic64_t
instead of a u64. This causes CO-RE reading of the field to fail due to the
type mismatch. Handle this by adding CO-RE checks for the old type as well
and using the CO-RE facility to check for the right type at load time.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
31 lines
896 B
C
31 lines
896 B
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#include <linux/bpf.h>
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#include <asm/ptrace.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_core_read.h>
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#include "bpf-defs.h"
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int bond_ifindex = 0;
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int active_slave_ifindex = 0;
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volatile const int netns_cookie = INIT_NS;
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SEC("kprobe/bond_select_active_slave")
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int BPF_KPROBE(handle_select_slave, struct bonding *bond)
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{
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struct net_device *dev = BPF_PROBE_READ(bond, dev);
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struct net *net = BPF_CORE_READ(dev, nd_net.net);
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int ifindex = BPF_CORE_READ(dev, ifindex);
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__u64 cookie = read_net_cookie(net);
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if (cookie == netns_cookie && ifindex == bond_ifindex) {
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struct net_device *active_dev = BPF_PROBE_READ(bond, curr_active_slave, dev);
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active_slave_ifindex = BPF_CORE_READ(active_dev, ifindex);
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}
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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