On 1/23/18, 5:05 PM, "Daniel Borkmann" <dan...@iogearbox.net> wrote:
On 01/20/2018 02:45 AM, Lawrence Brakmo wrote:
> Add support for reading many more tcp_sock fields
>
> state, same as sk->sk_state
> rtt_min same as sk->rtt_min.s[0].v (current rtt_min)
> snd_ssthresh
> rcv_nxt
> snd_nxt
> snd_una
> mss_cache
> ecn_flags
> rate_delivered
> rate_interval_us
> packets_out
> retrans_out
> total_retrans
> segs_in
> data_segs_in
> segs_out
> data_segs_out
> bytes_received (__u64)
> bytes_acked (__u64)
>
> Signed-off-by: Lawrence Brakmo <bra...@fb.com>
> ---
> include/uapi/linux/bpf.h | 19 +++++++
> net/core/filter.c | 134
++++++++++++++++++++++++++++++++++++++++++-----
> 2 files changed, 140 insertions(+), 13 deletions(-)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 2a8c40a..ff34f3c 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -979,6 +979,25 @@ struct bpf_sock_ops {
> __u32 snd_cwnd;
> __u32 srtt_us; /* Averaged RTT << 3 in usecs */
> __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
> + __u32 state;
> + __u32 rtt_min;
> + __u32 snd_ssthresh;
> + __u32 rcv_nxt;
> + __u32 snd_nxt;
> + __u32 snd_una;
> + __u32 mss_cache;
> + __u32 ecn_flags;
> + __u32 rate_delivered;
> + __u32 rate_interval_us;
> + __u32 packets_out;
> + __u32 retrans_out;
> + __u32 total_retrans;
> + __u32 segs_in;
> + __u32 data_segs_in;
> + __u32 segs_out;
> + __u32 data_segs_out;
Btw, this will have a 4 bytes hole in here which the user can otherwise
address out of the prog. Could you add the sk_txhash from the next patch
in between here instead?
Good point. Will fix in new patch. Thanks Daniel.
> + __u64 bytes_received;
> + __u64 bytes_acked;
> };
>
> /* List of known BPF sock_ops operators.
> diff --git a/net/core/filter.c b/net/core/filter.c
> index c9411dc..98665ba 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -3849,34 +3849,43 @@ void bpf_warn_invalid_xdp_action(u32 act)
> }
> EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
>
> -static bool __is_valid_sock_ops_access(int off, int size)
> +static bool sock_ops_is_valid_access(int off, int size,
> + enum bpf_access_type type,
> + struct bpf_insn_access_aux *info)
> {
> + const int size_default = sizeof(__u32);
> +
> if (off < 0 || off >= sizeof(struct bpf_sock_ops))
> return false;
> +
> /* The verifier guarantees that size > 0. */
> if (off % size != 0)
> return false;
> - if (size != sizeof(__u32))
> - return false;
> -
> - return true;
> -}
>
> -static bool sock_ops_is_valid_access(int off, int size,
> - enum bpf_access_type type,
> - struct bpf_insn_access_aux *info)
> -{
> if (type == BPF_WRITE) {
> switch (off) {
> - case offsetof(struct bpf_sock_ops, op) ...
> - offsetof(struct bpf_sock_ops, replylong[3]):
> + case bpf_ctx_range_till(struct bpf_sock_ops, op, replylong[3]):
> + if (size != size_default)
> + return false;
> break;
> default:
> return false;
> }
> + } else {
> + switch (off) {
> + case bpf_ctx_range_till(struct bpf_sock_ops, bytes_received,
> + bytes_acked):
> + if (size != sizeof(__u64))
> + return false;
> + break;
> + default:
> + if (size != size_default)
> + return false;
> + break;
> + }
> }
>
> - return __is_valid_sock_ops_access(off, size);
> + return true;
> }
