A BPF application, e.g., a TCP congestion control, might benefit from or even require precise (=hardware) packet timestamps. These timestamps are already available in __sk_buff.hwtstamp and bpf_sock_ops.skb_hwtstamp, but could not be requested: A BPF program was not allowed to set SO_TIMESTAMPING* on a socket.
Enable BPF programs to actively request the generation of timestamps from a stream socket. The also required ioctl(SIOCSHWTSTAMP) on the network device must still be done separately, in user space.
Signed-off-by: Jörn-Thorben Hinz jthinz@mailbox.tu-berlin.de --- include/uapi/linux/bpf.h | 3 ++- net/core/filter.c | 2 ++ tools/include/uapi/linux/bpf.h | 3 ++- tools/testing/selftests/bpf/progs/bpf_tracing_net.h | 2 ++ tools/testing/selftests/bpf/progs/setget_sockopt.c | 4 ++++ 5 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 60a9d59beeab..3e64b8137931 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2640,7 +2640,8 @@ union bpf_attr { * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**, * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**, * **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**, - * **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**. + * **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**, + * **SO_TIMESTAMPING_NEW**, **SO_TIMESTAMPING_OLD**. * * **IPPROTO_TCP**, which supports the following *optname*\ s: * **TCP_CONGESTION**, **TCP_BPF_IW**, * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**, diff --git a/net/core/filter.c b/net/core/filter.c index 06ba0e56e369..af0f3a6762de 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5108,6 +5108,8 @@ static int sol_socket_sockopt(struct sock *sk, int optname, case SO_MAX_PACING_RATE: case SO_BINDTOIFINDEX: case SO_TXREHASH: + case SO_TIMESTAMPING_NEW: + case SO_TIMESTAMPING_OLD: if (*optlen != sizeof(int)) return -EINVAL; break; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 60a9d59beeab..3e64b8137931 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2640,7 +2640,8 @@ union bpf_attr { * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**, * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**, * **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**, - * **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**. + * **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**, + * **SO_TIMESTAMPING_NEW**, **SO_TIMESTAMPING_OLD**. * * **IPPROTO_TCP**, which supports the following *optname*\ s: * **TCP_CONGESTION**, **TCP_BPF_IW**, * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**, diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index cfed4df490f3..8d526db8ceeb 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -15,8 +15,10 @@ #define SO_RCVLOWAT 18 #define SO_BINDTODEVICE 25 #define SO_MARK 36 +#define SO_TIMESTAMPING_OLD 37 #define SO_MAX_PACING_RATE 47 #define SO_BINDTOIFINDEX 62 +#define SO_TIMESTAMPING_NEW 65 #define SO_TXREHASH 74 #define __SO_ACCEPTCON (1 << 16)
diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c index 7a438600ae98..54205d10793c 100644 --- a/tools/testing/selftests/bpf/progs/setget_sockopt.c +++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c @@ -48,6 +48,10 @@ static const struct sockopt_test sol_socket_tests[] = { { .opt = SO_MARK, .new = 0xeb9f, .expected = 0xeb9f, }, { .opt = SO_MAX_PACING_RATE, .new = 0xeb9f, .expected = 0xeb9f, }, { .opt = SO_TXREHASH, .flip = 1, }, + { .opt = SO_TIMESTAMPING_NEW, .new = SOF_TIMESTAMPING_RX_HARDWARE, + .expected = SOF_TIMESTAMPING_RX_HARDWARE, }, + { .opt = SO_TIMESTAMPING_OLD, .new = SOF_TIMESTAMPING_RX_HARDWARE, + .expected = SOF_TIMESTAMPING_RX_HARDWARE, }, { .opt = 0, }, };