Commit 29003875 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: Change bpf_setsockopt(SOL_SOCKET) to reuse sk_setsockopt() 



After the prep work in the previous patches,
this patch removes most of the dup code from bpf_setsockopt(SOL_SOCKET)
and reuses them from sk_setsockopt().

The sock ptr test is added to the SO_RCVLOWAT because
the sk->sk_socket could be NULL in some of the bpf hooks.

The existing optname white-list is refactored into a new
function sol_socket_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/20220817061804.4178920-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ebf9e8e6

include/net/sock.h

+2 −0
Original line number Diff line number Diff line
@@ -1828,6 +1828,8 @@ void sock_pfree(struct sk_buff *skb); 
#define sock_edemux sock_efree

#endif



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

		  sockptr_t optval, unsigned int optlen);

int sock_setsockopt(struct socket *sock, int level, int op,

		    sockptr_t optval, unsigned int optlen);

net/core/filter.c

+29 −95
Original line number Diff line number Diff line
@@ -5013,109 +5013,43 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { 
	.arg1_type      = ARG_PTR_TO_CTX,

};



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

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

				 char *optval, int optlen)

{

	char devname[IFNAMSIZ];

	int val, valbool;

	struct net *net;

	int ifindex;

	int ret = 0;



	if (!sk_fullsock(sk))

		return -EINVAL;



	if (level == SOL_SOCKET) {

		if (optlen != sizeof(int) && optname != SO_BINDTODEVICE)

			return -EINVAL;

		val = *((int *)optval);

		valbool = val ? 1 : 0;



		/* Only some socketops are supported */

	switch (optname) {

		case SO_RCVBUF:

			val = min_t(u32, val, sysctl_rmem_max);

			val = min_t(int, val, INT_MAX / 2);

			sk->sk_userlocks |= SOCK_RCVBUF_LOCK;

			WRITE_ONCE(sk->sk_rcvbuf,

				   max_t(int, val * 2, SOCK_MIN_RCVBUF));

			break;

	case SO_SNDBUF:

			val = min_t(u32, val, sysctl_wmem_max);

			val = min_t(int, val, INT_MAX / 2);

			sk->sk_userlocks |= SOCK_SNDBUF_LOCK;

			WRITE_ONCE(sk->sk_sndbuf,

				   max_t(int, val * 2, SOCK_MIN_SNDBUF));

			break;

		case SO_MAX_PACING_RATE: /* 32bit version */

			if (val != ~0U)

				cmpxchg(&sk->sk_pacing_status,

					SK_PACING_NONE,

					SK_PACING_NEEDED);

			sk->sk_max_pacing_rate = (val == ~0U) ?

						 ~0UL : (unsigned int)val;

			sk->sk_pacing_rate = min(sk->sk_pacing_rate,

						 sk->sk_max_pacing_rate);

			break;

	case SO_RCVBUF:

	case SO_KEEPALIVE:

	case SO_PRIORITY:

			sk->sk_priority = val;

			break;

	case SO_REUSEPORT:

	case SO_RCVLOWAT:

			if (val < 0)

				val = INT_MAX;

			if (sk->sk_socket && sk->sk_socket->ops->set_rcvlowat)

				ret = sk->sk_socket->ops->set_rcvlowat(sk, val);

			else

				WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);

			break;

	case SO_MARK:

			if (sk->sk_mark != val) {

				sk->sk_mark = val;

				sk_dst_reset(sk);

			}

			break;

		case SO_BINDTODEVICE:

			optlen = min_t(long, optlen, IFNAMSIZ - 1);

			strncpy(devname, optval, optlen);

			devname[optlen] = 0;



			ifindex = 0;

			if (devname[0] != '\0') {

				struct net_device *dev;



				ret = -ENODEV;



				net = sock_net(sk);

				dev = dev_get_by_name(net, devname);

				if (!dev)

					break;

				ifindex = dev->ifindex;

				dev_put(dev);

			}

			fallthrough;

	case SO_MAX_PACING_RATE:

	case SO_BINDTOIFINDEX:

			if (optname == SO_BINDTOIFINDEX)

				ifindex = val;

			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;

		case SO_REUSEPORT:

			sk->sk_reuseport = valbool;

			break;

	case SO_TXREHASH:

			if (val < -1 || val > 1) {

				ret = -EINVAL;

		if (optlen != sizeof(int))

			return -EINVAL;

		break;

			}

			sk->sk_txrehash = (u8)val;

	case SO_BINDTODEVICE:

		break;

	default:

			ret = -EINVAL;

		return -EINVAL;

	}



	return sk_setsockopt(sk, SOL_SOCKET, optname,

			     KERNEL_SOCKPTR(optval), optlen);

}



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

			    char *optval, int optlen)

{

	int val, ret = 0;



	if (!sk_fullsock(sk))

		return -EINVAL;



	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;

net/core/sock.c

+3 −3
Original line number Diff line number Diff line
@@ -1077,7 +1077,7 @@ EXPORT_SYMBOL(sockopt_capable); 
 *	at the socket level. Everything here is generic.

 */



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

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

		  sockptr_t optval, unsigned int optlen)

{

	struct so_timestamping timestamping;
@@ -1264,7 +1264,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname, 
	case SO_RCVLOWAT:

		if (val < 0)

			val = INT_MAX;

		if (sock->ops->set_rcvlowat)

		if (sock && sock->ops->set_rcvlowat)

			ret = sock->ops->set_rcvlowat(sk, val);

		else

			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);