Commit 1e7d217f authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
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bpf: Refactor bpf_setsockopt(TCP_CONGESTION) handling into another function 



This patch moves the bpf_setsockopt(TCP_CONGESTION) logic into
another function.  The next patch will add extra logic to avoid
recursion and this will make the latter patch easier to follow.

Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220929070407.965581-4-martin.lau@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 37cfbe0b

net/core/filter.c

+28 −17
Original line number Diff line number Diff line
@@ -5102,6 +5102,33 @@ static int bpf_sol_tcp_setsockopt(struct sock *sk, int optname, 
	return 0;

}



static int sol_tcp_sockopt_congestion(struct sock *sk, char *optval,

				      int *optlen, bool getopt)

{

	if (*optlen < 2)

		return -EINVAL;



	if (getopt) {

		if (!inet_csk(sk)->icsk_ca_ops)

			return -EINVAL;

		/* BPF expects NULL-terminated tcp-cc string */

		optval[--(*optlen)] = '\0';

		return do_tcp_getsockopt(sk, SOL_TCP, TCP_CONGESTION,

					 KERNEL_SOCKPTR(optval),

					 KERNEL_SOCKPTR(optlen));

	}



	/* "cdg" is the only cc that alloc a ptr

	 * in inet_csk_ca area.  The bpf-tcp-cc may

	 * overwrite this ptr after switching to cdg.

	 */

	if (*optlen >= sizeof("cdg") - 1 && !strncmp("cdg", optval, *optlen))

		return -ENOTSUPP;



	return do_tcp_setsockopt(sk, SOL_TCP, TCP_CONGESTION,

				KERNEL_SOCKPTR(optval), *optlen);

}



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

			   char *optval, int *optlen,

			   bool getopt)
@@ -5125,16 +5152,7 @@ static int sol_tcp_sockopt(struct sock *sk, int optname, 
			return -EINVAL;

		break;

	case TCP_CONGESTION:

		if (*optlen < 2)

			return -EINVAL;

		/* "cdg" is the only cc that alloc a ptr

		 * in inet_csk_ca area.  The bpf-tcp-cc may

		 * overwrite this ptr after switching to cdg.

		 */

		if (!getopt && *optlen >= sizeof("cdg") - 1 &&

		    !strncmp("cdg", optval, *optlen))

			return -ENOTSUPP;

		break;

		return sol_tcp_sockopt_congestion(sk, optval, optlen, getopt);

	case TCP_SAVED_SYN:

		if (*optlen < 1)

			return -EINVAL;
@@ -5159,13 +5177,6 @@ static int sol_tcp_sockopt(struct sock *sk, int optname, 
			return 0;

		}



		if (optname == TCP_CONGESTION) {

			if (!inet_csk(sk)->icsk_ca_ops)

				return -EINVAL;

			/* BPF expects NULL-terminated tcp-cc string */

			optval[--(*optlen)] = '\0';

		}



		return do_tcp_getsockopt(sk, SOL_TCP, optname,

					 KERNEL_SOCKPTR(optval),

					 KERNEL_SOCKPTR(optlen));