Re: [PATCH bpf-next]: add sock_ops R/W access to ipv4 tos
flat view
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2018-03-28 13:47:46
On 03/26/2018 05:36 PM, Nikita V. Shirokov wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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?
quoted hunk ↗ jump to hunk
+ } + 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().
quoted hunk ↗ jump to hunk
+ break; + default: + goto err_clear; + } #if IS_ENABLED(CONFIG_IPV6) } else if (level == SOL_IPV6) { struct ipv6_pinfo *np = inet6_sk(sk);