On 03/26/2018 05:36 PM, Nikita V. Shirokov wrote:
> bpf: Add sock_ops R/W access to ipv4 tos
>
> Sample usage for tos:
>
> bpf_getsockopt(skops, SOL_IP, IP_TOS, &v, sizeof(v))
>
> where skops is a pointer to the ctx (struct bpf_sock_ops).
>
> Signed-off-by: Nikita V. Shirokov <tehn...@fb.com>
> ---
> net/core/filter.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 00c711c..afd8255 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -3462,6 +3462,27 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *,
> bpf_sock,
> ret = -EINVAL;
> }
> #ifdef CONFIG_INET
> + } else if (level == SOL_IP) {
> + if (optlen != sizeof(int) || sk->sk_family != AF_INET)
> + return -EINVAL;
> +
> + val = *((int *)optval);
> + /* Only some options are supported */
> + switch (optname) {
> + case IP_TOS:
> + if (val < -1 || val > 0xff) {
> + ret = -EINVAL;
> + } else {
> + struct inet_sock *inet = inet_sk(sk);
> +
> + if (val == -1)
> + val = 0;
> + inet->tos = val;
Should this not have the exact same semantics given the helper resembles
the normal setsockopt? do_ip_setsockopt() does the following when setting
IP_TOS:
case IP_TOS: /* This sets both TOS and Precedence */
if (sk->sk_type == SOCK_STREAM) {
val &= ~INET_ECN_MASK;
val |= inet->tos & INET_ECN_MASK;
}
if (inet->tos != val) {
inet->tos = val;
sk->sk_priority = rt_tos2priority(val);
sk_dst_reset(sk);
}
break;
E.g. why we don't need to set sk->sk_priority as well or reset the dst
entry here?
> + }
> + break;
> + default:
> + ret = -EINVAL;
> + }
> #if IS_ENABLED(CONFIG_IPV6)
> } else if (level == SOL_IPV6) {
> if (optlen != sizeof(int) || sk->sk_family != AF_INET6)
> @@ -3561,6 +3582,20 @@ BPF_CALL_5(bpf_getsockopt, struct bpf_sock_ops_kern *,
> bpf_sock,
> } else {
> goto err_clear;
> }
> + } else if (level == SOL_IP) {
> + struct inet_sock *inet = inet_sk(sk);
> +
> + if (optlen != sizeof(int) || sk->sk_family != AF_INET)
> + goto err_clear;
> +
> + /* Only some options are supported */
> + switch (optname) {
> + case IP_TOS:
> + *((int *)optval) = (int)inet->tos;
This part is fine though, same as in do_ip_getsockopt().
> + break;
> + default:
> + goto err_clear;
> + }
> #if IS_ENABLED(CONFIG_IPV6)
> } else if (level == SOL_IPV6) {
> struct ipv6_pinfo *np = inet6_sk(sk);
>
