Commit 65ddc82d authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: Change bpf_getsockopt(SOL_SOCKET) to reuse sk_getsockopt() 



This patch changes bpf_getsockopt(SOL_SOCKET) to reuse
sk_getsockopt().  It removes all duplicated code from
bpf_getsockopt(SOL_SOCKET).

Before this patch, there were some optnames available to
bpf_setsockopt(SOL_SOCKET) but missing in bpf_getsockopt(SOL_SOCKET).
It surprises users from time to time.  For example, SO_REUSEADDR,
SO_KEEPALIVE, SO_RCVLOWAT, and SO_MAX_PACING_RATE.  This patch
automatically closes this gap without duplicating more code.
The only exception is SO_BINDTODEVICE because it needs to acquire a
blocking lock.  Thus, SO_BINDTODEVICE is not supported.

Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002912.2894040-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent c2b063ca

include/net/sock.h

+2 −0
Original line number Diff line number Diff line
@@ -1833,6 +1833,8 @@ int sk_setsockopt(struct sock *sk, int level, int optname, 
int sock_setsockopt(struct socket *sock, int level, int op,

		    sockptr_t optval, unsigned int optlen);



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

		  sockptr_t optval, sockptr_t optlen);

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

		    char __user *optval, int __user *optlen);

int sock_gettstamp(struct socket *sock, void __user *userstamp,

net/core/filter.c

+23 −34
Original line number Diff line number Diff line
@@ -5017,8 +5017,9 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { 
	.arg1_type      = ARG_PTR_TO_CTX,

};



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

				 char *optval, int optlen)

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

			      char *optval, int *optlen,

			      bool getopt)

{

	switch (optname) {

	case SO_REUSEADDR:
@@ -5032,7 +5033,7 @@ static int sol_socket_setsockopt(struct sock *sk, int optname, 
	case SO_MAX_PACING_RATE:

	case SO_BINDTOIFINDEX:

	case SO_TXREHASH:

		if (optlen != sizeof(int))

		if (*optlen != sizeof(int))

			return -EINVAL;

		break;

	case SO_BINDTODEVICE:
@@ -5041,8 +5042,16 @@ static int sol_socket_setsockopt(struct sock *sk, int optname, 
		return -EINVAL;

	}



	if (getopt) {

		if (optname == SO_BINDTODEVICE)

			return -EINVAL;

		return sk_getsockopt(sk, SOL_SOCKET, optname,

				     KERNEL_SOCKPTR(optval),

				     KERNEL_SOCKPTR(optlen));

	}



	return sk_setsockopt(sk, SOL_SOCKET, optname,

			     KERNEL_SOCKPTR(optval), optlen);

			     KERNEL_SOCKPTR(optval), *optlen);

}



static int bpf_sol_tcp_setsockopt(struct sock *sk, int optname,
@@ -5168,7 +5177,7 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname, 
		return -EINVAL;



	if (level == SOL_SOCKET)

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

		return sol_socket_sockopt(sk, optname, optval, &optlen, false);

	else if (IS_ENABLED(CONFIG_INET) && level == SOL_IP)

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

	else if (IS_ENABLED(CONFIG_IPV6) && level == SOL_IPV6)
@@ -5190,38 +5199,13 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, 
static int __bpf_getsockopt(struct sock *sk, int level, int optname,

			    char *optval, int optlen)

{

	int err = 0, saved_optlen = optlen;



	if (!sk_fullsock(sk))

		goto err_clear;



	if (level == SOL_SOCKET) {

		if (optlen != sizeof(int))

			goto err_clear;



		switch (optname) {

		case SO_RCVBUF:

			*((int *)optval) = sk->sk_rcvbuf;

			break;

		case SO_SNDBUF:

			*((int *)optval) = sk->sk_sndbuf;

			break;

		case SO_MARK:

			*((int *)optval) = sk->sk_mark;

			break;

		case SO_PRIORITY:

			*((int *)optval) = sk->sk_priority;

			break;

		case SO_BINDTOIFINDEX:

			*((int *)optval) = sk->sk_bound_dev_if;

			break;

		case SO_REUSEPORT:

			*((int *)optval) = sk->sk_reuseport;

			break;

		case SO_TXREHASH:

			*((int *)optval) = sk->sk_txrehash;

			break;

		default:

			goto err_clear;

		}

		err = sol_socket_sockopt(sk, optname, optval, &optlen, true);

	} else if (IS_ENABLED(CONFIG_INET) &&

		   level == SOL_TCP && sk->sk_prot->getsockopt == tcp_getsockopt) {

		struct inet_connection_sock *icsk;
@@ -5278,7 +5262,12 @@ static int __bpf_getsockopt(struct sock *sk, int level, int optname, 
	} else {

		goto err_clear;

	}

	return 0;



	if (err)

		optlen = 0;

	if (optlen < saved_optlen)

		memset(optval + optlen, 0, saved_optlen - optlen);

	return err;

err_clear:

	memset(optval, 0, optlen);

	return -EINVAL;

net/core/sock.c

+2 −2
Original line number Diff line number Diff line
@@ -1583,7 +1583,7 @@ static int groups_to_user(sockptr_t dst, const struct group_info *src) 
	return 0;

}



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

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

		  sockptr_t optval, sockptr_t optlen)

{

	struct socket *sock = sk->sk_socket;