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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /samples/bpf/xdp_sample_pkts_kern.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/xdp_sample_pkts_kern.c')
-rw-r--r-- | samples/bpf/xdp_sample_pkts_kern.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/samples/bpf/xdp_sample_pkts_kern.c b/samples/bpf/xdp_sample_pkts_kern.c new file mode 100644 index 000000000..9cf76b340 --- /dev/null +++ b/samples/bpf/xdp_sample_pkts_kern.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/ptrace.h> +#include <linux/version.h> +#include <uapi/linux/bpf.h> +#include <bpf/bpf_helpers.h> + +#define SAMPLE_SIZE 64ul + +struct { + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); + __uint(key_size, sizeof(int)); + __uint(value_size, sizeof(u32)); +} my_map SEC(".maps"); + +SEC("xdp_sample") +int xdp_sample_prog(struct xdp_md *ctx) +{ + void *data_end = (void *)(long)ctx->data_end; + void *data = (void *)(long)ctx->data; + + /* Metadata will be in the perf event before the packet data. */ + struct S { + u16 cookie; + u16 pkt_len; + } __packed metadata; + + if (data < data_end) { + /* The XDP perf_event_output handler will use the upper 32 bits + * of the flags argument as a number of bytes to include of the + * packet payload in the event data. If the size is too big, the + * call to bpf_perf_event_output will fail and return -EFAULT. + * + * See bpf_xdp_event_output in net/core/filter.c. + * + * The BPF_F_CURRENT_CPU flag means that the event output fd + * will be indexed by the CPU number in the event map. + */ + u64 flags = BPF_F_CURRENT_CPU; + u16 sample_size; + int ret; + + metadata.cookie = 0xdead; + metadata.pkt_len = (u16)(data_end - data); + sample_size = min(metadata.pkt_len, SAMPLE_SIZE); + flags |= (u64)sample_size << 32; + + ret = bpf_perf_event_output(ctx, &my_map, flags, + &metadata, sizeof(metadata)); + if (ret) + bpf_printk("perf_event_output failed: %d\n", ret); + } + + return XDP_PASS; +} + +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; |