bpf: Add sock_ops R/W access to tclass

Adds direct write access to sk_txhash and access to tclass for ipv6
flows through getsockopt and setsockopt. Sample usage for tclass:

  bpf_getsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v, sizeof(v))

where skops is a pointer to the ctx (struct bpf_sock_ops).

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Lawrence Brakmo 2018-01-25 16:14:13 -08:00 committed by Alexei Starovoitov
parent 44f0e43037
commit 6f9bd3d731
1 changed files with 45 additions and 2 deletions

View File

@ -3232,6 +3232,29 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
ret = -EINVAL;
}
#ifdef CONFIG_INET
#if IS_ENABLED(CONFIG_IPV6)
} else if (level == SOL_IPV6) {
if (optlen != sizeof(int) || sk->sk_family != AF_INET6)
return -EINVAL;
val = *((int *)optval);
/* Only some options are supported */
switch (optname) {
case IPV6_TCLASS:
if (val < -1 || val > 0xff) {
ret = -EINVAL;
} else {
struct ipv6_pinfo *np = inet6_sk(sk);
if (val == -1)
val = 0;
np->tclass = val;
}
break;
default:
ret = -EINVAL;
}
#endif
} else if (level == SOL_TCP &&
sk->sk_prot->setsockopt == tcp_setsockopt) {
if (optname == TCP_CONGESTION) {
@ -3241,7 +3264,8 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock,
strncpy(name, optval, min_t(long, optlen,
TCP_CA_NAME_MAX-1));
name[TCP_CA_NAME_MAX-1] = 0;
ret = tcp_set_congestion_control(sk, name, false, reinit);
ret = tcp_set_congestion_control(sk, name, false,
reinit);
} else {
struct tcp_sock *tp = tcp_sk(sk);
@ -3307,6 +3331,22 @@ BPF_CALL_5(bpf_getsockopt, struct bpf_sock_ops_kern *, bpf_sock,
} else {
goto err_clear;
}
#if IS_ENABLED(CONFIG_IPV6)
} else if (level == SOL_IPV6) {
struct ipv6_pinfo *np = inet6_sk(sk);
if (optlen != sizeof(int) || sk->sk_family != AF_INET6)
goto err_clear;
/* Only some options are supported */
switch (optname) {
case IPV6_TCLASS:
*((int *)optval) = (int)np->tclass;
break;
default:
goto err_clear;
}
#endif
} else {
goto err_clear;
}
@ -3871,6 +3911,7 @@ static bool sock_ops_is_valid_access(int off, int size,
if (type == BPF_WRITE) {
switch (off) {
case offsetof(struct bpf_sock_ops, reply):
case offsetof(struct bpf_sock_ops, sk_txhash):
if (size != size_default)
return false;
break;
@ -4690,7 +4731,8 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
break;
case offsetof(struct bpf_sock_ops, sk_txhash):
SOCK_OPS_GET_FIELD(sk_txhash, sk_txhash, struct sock);
SOCK_OPS_GET_OR_SET_FIELD(sk_txhash, sk_txhash,
struct sock, type);
break;
case offsetof(struct bpf_sock_ops, bytes_received):
@ -4701,6 +4743,7 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
case offsetof(struct bpf_sock_ops, bytes_acked):
SOCK_OPS_GET_FIELD(bytes_acked, bytes_acked, struct tcp_sock);
break;
}
return insn - insn_buf;
}