On Thu, Mar 1, 2018 at 2:18 AM, Daniel Borkmann <dan...@iogearbox.net> wrote:
> On 03/01/2018 01:11 AM, William Tu wrote:
>> Currently GRE sequence number can only be used in native
>> tunnel mode. This patch adds sequence number support for
>> gre collect metadata mode. RFC2890 defines GRE sequence
>> number to be specific to the traffic flow identified by the
>> key. However, this patch does not implement per-key seqno.
>> The sequence number is shared in the same tunnel device.
>> That is, different tunnel keys using the same collect_md
>> tunnel share single sequence number.
>>
>> Signed-off-by: William Tu <u9012...@gmail.com>
>> ---
>> include/uapi/linux/bpf.h | 1 +
>> net/core/filter.c | 4 +++-
>> net/ipv4/ip_gre.c | 7 +++++--
>> net/ipv6/ip6_gre.c | 13 ++++++++-----
>> 4 files changed, 17 insertions(+), 8 deletions(-)
>>
>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>> index db6bdc375126..2c6dd942953d 100644
>> --- a/include/uapi/linux/bpf.h
>> +++ b/include/uapi/linux/bpf.h
>> @@ -800,6 +800,7 @@ enum bpf_func_id {
>> /* BPF_FUNC_skb_set_tunnel_key flags. */
>> #define BPF_F_ZERO_CSUM_TX (1ULL << 1)
>> #define BPF_F_DONT_FRAGMENT (1ULL << 2)
>> +#define BPF_F_GRE_SEQ (1ULL << 3)
>>
>> /* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
>> * BPF_FUNC_perf_event_read_value flags.
>> diff --git a/net/core/filter.c b/net/core/filter.c
>> index 0c121adbdbaa..010305e0791a 100644
>> --- a/net/core/filter.c
>> +++ b/net/core/filter.c
>> @@ -2991,7 +2991,7 @@ BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *,
>> skb,
>> struct ip_tunnel_info *info;
>>
>> if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6 | BPF_F_ZERO_CSUM_TX |
>> - BPF_F_DONT_FRAGMENT)))
>> + BPF_F_DONT_FRAGMENT | BPF_F_GRE_SEQ)))
>> return -EINVAL;
>> if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
>> switch (size) {
>> @@ -3025,6 +3025,8 @@ BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *,
>> skb,
>> info->key.tun_flags |= TUNNEL_DONT_FRAGMENT;
>> if (flags & BPF_F_ZERO_CSUM_TX)
>> info->key.tun_flags &= ~TUNNEL_CSUM;
>> + if (flags & BPF_F_GRE_SEQ)
>> + info->key.tun_flags |= TUNNEL_SEQ;
>
> Ok, looks fine. My only minor request would be to rename BPF_F_GRE_SEQ
> into e.g. BPF_F_SEQ_NUMBER to at least not have something GRE specific
> in the name in case we could later on reuse it elsewhere as well, and
> the bpf_skb_set_tunnel_key() is unaware of the underlying encap anyway.
OK, make sense. Thanks!
I will rename it in the next version.
William
