Commit 0c751f70 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: Change bpf_setsockopt(SOL_TCP) to reuse do_tcp_setsockopt() 



After the prep work in the previous patches,
this patch removes all the dup code from bpf_setsockopt(SOL_TCP)
and reuses the do_tcp_setsockopt().

The existing optname white-list is refactored into a new
function sol_tcp_setsockopt().  The sol_tcp_setsockopt()
also calls the bpf_sol_tcp_setsockopt() to handle
the TCP_BPF_XXX specific optnames.

bpf_setsockopt(TCP_SAVE_SYN) now also allows a value 2 to
save the eth header also and it comes for free from
do_tcp_setsockopt().

Reviewed-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061819.4180146-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 57db31a1

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -405,6 +405,8 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, 
int tcp_getsockopt(struct sock *sk, int level, int optname,

		   char __user *optval, int __user *optlen);

bool tcp_bpf_bypass_getsockopt(int level, int optname);

int do_tcp_setsockopt(struct sock *sk, int level, int optname,

		      sockptr_t optval, unsigned int optlen);

int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,

		   unsigned int optlen);

void tcp_set_keepalive(struct sock *sk, int val);

net/core/filter.c

+30 −67
Original line number Diff line number Diff line
@@ -5086,6 +5086,34 @@ static int bpf_sol_tcp_setsockopt(struct sock *sk, int optname, 
	return 0;

}



static int sol_tcp_setsockopt(struct sock *sk, int optname,

			      char *optval, int optlen)

{

	if (sk->sk_prot->setsockopt != tcp_setsockopt)

		return -EINVAL;



	switch (optname) {

	case TCP_KEEPIDLE:

	case TCP_KEEPINTVL:

	case TCP_KEEPCNT:

	case TCP_SYNCNT:

	case TCP_WINDOW_CLAMP:

	case TCP_USER_TIMEOUT:

	case TCP_NOTSENT_LOWAT:

	case TCP_SAVE_SYN:

		if (optlen != sizeof(int))

			return -EINVAL;

		break;

	case TCP_CONGESTION:

		break;

	default:

		return bpf_sol_tcp_setsockopt(sk, optname, optval, optlen);

	}



	return do_tcp_setsockopt(sk, SOL_TCP, optname,

				 KERNEL_SOCKPTR(optval), optlen);

}



static int __bpf_setsockopt(struct sock *sk, int level, int optname,

			    char *optval, int optlen)

{
@@ -5138,73 +5166,8 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname, 
		default:

			ret = -EINVAL;

		}

	} else if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP &&

		   sk->sk_prot->setsockopt == tcp_setsockopt) {

		if (optname >= TCP_BPF_IW)

			return bpf_sol_tcp_setsockopt(sk, optname,

						      optval, optlen);



		if (optname == TCP_CONGESTION) {

			char name[TCP_CA_NAME_MAX];



			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, true);

		} else {

			struct inet_connection_sock *icsk = inet_csk(sk);

			struct tcp_sock *tp = tcp_sk(sk);



			if (optlen != sizeof(int))

				return -EINVAL;



			val = *((int *)optval);

			/* Only some options are supported */

			switch (optname) {

			case TCP_SAVE_SYN:

				if (val < 0 || val > 1)

					ret = -EINVAL;

				else

					tp->save_syn = val;

				break;

			case TCP_KEEPIDLE:

				ret = tcp_sock_set_keepidle_locked(sk, val);

				break;

			case TCP_KEEPINTVL:

				if (val < 1 || val > MAX_TCP_KEEPINTVL)

					ret = -EINVAL;

				else

					tp->keepalive_intvl = val * HZ;

				break;

			case TCP_KEEPCNT:

				if (val < 1 || val > MAX_TCP_KEEPCNT)

					ret = -EINVAL;

				else

					tp->keepalive_probes = val;

				break;

			case TCP_SYNCNT:

				if (val < 1 || val > MAX_TCP_SYNCNT)

					ret = -EINVAL;

				else

					icsk->icsk_syn_retries = val;

				break;

			case TCP_USER_TIMEOUT:

				if (val < 0)

					ret = -EINVAL;

				else

					icsk->icsk_user_timeout = val;

				break;

			case TCP_NOTSENT_LOWAT:

				tp->notsent_lowat = val;

				sk->sk_write_space(sk);

				break;

			case TCP_WINDOW_CLAMP:

				ret = tcp_set_window_clamp(sk, val);

				break;

			default:

				ret = -EINVAL;

			}

		}

	} else if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP) {

		return sol_tcp_setsockopt(sk, optname, optval, optlen);

	} else {

		ret = -EINVAL;

	}

net/ipv4/tcp.c

+2 −2
Original line number Diff line number Diff line
@@ -3479,7 +3479,7 @@ int tcp_set_window_clamp(struct sock *sk, int val) 
/*

 *	Socket option code for TCP.

 */

static int do_tcp_setsockopt(struct sock *sk, int level, int optname,

int do_tcp_setsockopt(struct sock *sk, int level, int optname,

		      sockptr_t optval, unsigned int optlen)

{

	struct tcp_sock *tp = tcp_sk(sk);