Commit f9bcf968 authored by Dmitry Yakunin's avatar Dmitry Yakunin Committed by Alexei Starovoitov
Browse files

bpf: Add SO_KEEPALIVE and related options to bpf_setsockopt 



This patch adds support of SO_KEEPALIVE flag and TCP related options
to bpf_setsockopt() routine. This is helpful if we want to enable or tune
TCP keepalive for applications which don't do it in the userspace code.

v3:
  - update kernel-doc in uapi (Nikita Vetoshkin <nekto0n@yandex-team.ru>)

v4:
  - update kernel-doc in tools too (Alexei Starovoitov)
  - add test to selftests (Alexei Starovoitov)

Signed-off-by: default avatarDmitry Yakunin <zeil@yandex-team.ru>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200620153052.9439-3-zeil@yandex-team.ru
parent aad4a0a9

include/uapi/linux/bpf.h

+5 −2
Original line number Diff line number Diff line
@@ -1621,10 +1621,13 @@ union bpf_attr { 
 *

 * 		* **SOL_SOCKET**, which supports the following *optname*\ s:

 * 		  **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,

 * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.

 * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,

 * 		  **SO_BINDTODEVICE**, **SO_KEEPALIVE**.

 * 		* **IPPROTO_TCP**, which supports the following *optname*\ s:

 * 		  **TCP_CONGESTION**, **TCP_BPF_IW**,

 * 		  **TCP_BPF_SNDCWND_CLAMP**.

 * 		  **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,

 * 		  **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,

 * 		  **TCP_SYNCNT**, **TCP_USER_TIMEOUT**.

 * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.

 * 		* **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.

 * 	Return

net/core/filter.c

+35 −1
Original line number Diff line number Diff line
@@ -4289,10 +4289,10 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, 
			   char *optval, int optlen, u32 flags)

{

	char devname[IFNAMSIZ];

	int val, valbool;

	struct net *net;

	int ifindex;

	int ret = 0;

	int val;



	if (!sk_fullsock(sk))

		return -EINVAL;
@@ -4303,6 +4303,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, 
		if (optlen != sizeof(int) && optname != SO_BINDTODEVICE)

			return -EINVAL;

		val = *((int *)optval);

		valbool = val ? 1 : 0;



		/* Only some socketops are supported */

		switch (optname) {
@@ -4361,6 +4362,11 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, 
			}

			ret = sock_bindtoindex(sk, ifindex, false);

			break;

		case SO_KEEPALIVE:

			if (sk->sk_prot->keepalive)

				sk->sk_prot->keepalive(sk, valbool);

			sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);

			break;

		default:

			ret = -EINVAL;

		}
@@ -4421,6 +4427,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, 
			ret = tcp_set_congestion_control(sk, name, false,

							 reinit, true);

		} else {

			struct inet_connection_sock *icsk = inet_csk(sk);

			struct tcp_sock *tp = tcp_sk(sk);



			if (optlen != sizeof(int))
@@ -4449,6 +4456,33 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, 
				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;

			default:

				ret = -EINVAL;

			}

tools/include/uapi/linux/bpf.h

+5 −2
Original line number Diff line number Diff line
@@ -1621,10 +1621,13 @@ union bpf_attr { 
 *

 * 		* **SOL_SOCKET**, which supports the following *optname*\ s:

 * 		  **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,

 * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.

 * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,

 * 		  **SO_BINDTODEVICE**, **SO_KEEPALIVE**.

 * 		* **IPPROTO_TCP**, which supports the following *optname*\ s:

 * 		  **TCP_CONGESTION**, **TCP_BPF_IW**,

 * 		  **TCP_BPF_SNDCWND_CLAMP**.

 * 		  **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,

 * 		  **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,

 * 		  **TCP_SYNCNT**, **TCP_USER_TIMEOUT**.

 * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.

 * 		* **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.

 * 	Return

tools/testing/selftests/bpf/progs/connect4_prog.c

+27 −0
Original line number Diff line number Diff line
@@ -104,6 +104,30 @@ static __inline int bind_to_device(struct bpf_sock_addr *ctx) 
	return 0;

}



static __inline int set_keepalive(struct bpf_sock_addr *ctx)

{

	int zero = 0, one = 1;



	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one)))

		return 1;

	if (ctx->type == SOCK_STREAM) {

		if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPIDLE, &one, sizeof(one)))

			return 1;

		if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPINTVL, &one, sizeof(one)))

			return 1;

		if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPCNT, &one, sizeof(one)))

			return 1;

		if (bpf_setsockopt(ctx, SOL_TCP, TCP_SYNCNT, &one, sizeof(one)))

			return 1;

		if (bpf_setsockopt(ctx, SOL_TCP, TCP_USER_TIMEOUT, &one, sizeof(one)))

			return 1;

	}

	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_KEEPALIVE, &zero, sizeof(zero)))

		return 1;



	return 0;

}



SEC("cgroup/connect4")

int connect_v4_prog(struct bpf_sock_addr *ctx)

{
@@ -121,6 +145,9 @@ int connect_v4_prog(struct bpf_sock_addr *ctx) 
	if (bind_to_device(ctx))

		return 0;



	if (set_keepalive(ctx))

		return 0;



	if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)

		return 0;

	else if (ctx->type == SOCK_STREAM)

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