BCC and passing packet from XDP to user-mode app #bcc


v.a.bonert@...
 
Edited

Hi!
 
Is it possible to pass full ethernet packet from XDP to user-mode app using BCC?
I wrote C code like this:
 
BPF_PERF_OUTPUT(captured_data);
capture(struct xdp_md *ctx)
{
    events.perf_submit(ctx, ...);
}
 
But there is no flags argument in perf_submit function (but bpf_perf_event_output has such argument).
 
Without BCC I can write such code to pass full packet to user-mode:
 
struct packet_info
{
    uint32_t packet_len;
    uint32_t iface_id;
};
 
struct bpf_map_def SEC("maps") captured_data =
{
    .type        = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
    .key_size    = sizeof(u32),
    .value_size  = sizeof(u32),
    .max_entries = MAX_CPUS
};
 
SEC("xdp")
int capture_kern(struct xdp_md *ctx)
{
    u32 len = ctx->data_end - ctx->data;
    u64 flags = BPF_F_CURRENT_CPU;
    flags |= (u64)len << 32;
    struct packet_info info = {len, ctx->ingress_ifindex};
    bpf_perf_event_output(ctx, &captured_data, flags, &info, sizeof(info));
 
    return XDP_PASS;
}
 
How can I do the same when using BCC?

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