bpf: Change bpf_setsockopt(SOL_IP) to reuse do_ip_setsockopt()

After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IP)
and reuses the implementation in do_ip_setsockopt().

The existing optname white-list is refactored into a new
function sol_ip_setsockopt().

NOTE,
the current bpf_setsockopt(IP_TOS) is quite different from the
the do_ip_setsockopt(IP_TOS).  For example, it does not take
the INET_ECN_MASK into the account for tcp and also does not adjust
sk->sk_priority.  It looks like the current bpf_setsockopt(IP_TOS)
was referencing the IPV6_TCLASS implementation instead of IP_TOS.
This patch tries to rectify that by using the do_ip_setsockopt(IP_TOS).
While this is a behavior change,  the do_ip_setsockopt(IP_TOS) behavior
is arguably what the user is expecting.  At least, the INET_ECN_MASK bits
should be masked out for tcp.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061826.4180990-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Martin KaFai Lau 2022-08-16 23:18:26 -07:00 committed by Alexei Starovoitov
parent 0c751f7071
commit ee7f1e1302
3 changed files with 24 additions and 22 deletions

View File

@ -743,6 +743,8 @@ void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
struct ipcm_cookie *ipc, bool allow_ipv6);
DECLARE_STATIC_KEY_FALSE(ip4_min_ttl);
int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
unsigned int optlen);
int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
unsigned int optlen);
int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,

View File

@ -5114,6 +5114,25 @@ static int sol_tcp_setsockopt(struct sock *sk, int optname,
KERNEL_SOCKPTR(optval), optlen);
}
static int sol_ip_setsockopt(struct sock *sk, int optname,
char *optval, int optlen)
{
if (sk->sk_family != AF_INET)
return -EINVAL;
switch (optname) {
case IP_TOS:
if (optlen != sizeof(int))
return -EINVAL;
break;
default:
return -EINVAL;
}
return do_ip_setsockopt(sk, SOL_IP, optname,
KERNEL_SOCKPTR(optval), optlen);
}
static int __bpf_setsockopt(struct sock *sk, int level, int optname,
char *optval, int optlen)
{
@ -5125,26 +5144,7 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname,
if (level == SOL_SOCKET) {
return sol_socket_setsockopt(sk, optname, optval, optlen);
} else if (IS_ENABLED(CONFIG_INET) && 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;
}
break;
default:
ret = -EINVAL;
}
return sol_ip_setsockopt(sk, optname, optval, optlen);
} else if (IS_ENABLED(CONFIG_IPV6) && level == SOL_IPV6) {
if (optlen != sizeof(int) || sk->sk_family != AF_INET6)
return -EINVAL;

View File

@ -888,7 +888,7 @@ static int compat_ip_mcast_join_leave(struct sock *sk, int optname,
DEFINE_STATIC_KEY_FALSE(ip4_min_ttl);
static int do_ip_setsockopt(struct sock *sk, int level, int optname,
int do_ip_setsockopt(struct sock *sk, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
struct inet_sock *inet = inet_sk(sk);