Commit 0b05b0cd authored by Breno Leitao's avatar Breno Leitao Committed by Jens Axboe
Browse files

net/socket: Break down __sys_getsockopt 



Split __sys_getsockopt() into two functions by removing the core
logic into a sub-function (do_sock_getsockopt()). This will avoid
code duplication when doing the same operation in other callers, for
instance.

do_sock_getsockopt() will be called by io_uring getsockopt() command
operation in the following patch.

The same was done for the setsockopt pair.

Suggested-by: default avatarMartin KaFai Lau <martin.lau@linux.dev>
Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Acked-by: default avatarJakub Kicinski <kuba@kernel.org>
Acked-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231016134750.1381153-5-leitao@debian.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1406245c

include/linux/bpf-cgroup.h

+1 −1
Original line number Diff line number Diff line
@@ -378,7 +378,7 @@ static inline bool cgroup_bpf_sock_enabled(struct sock *sk, 
({									       \

	int __ret = 0;							       \

	if (cgroup_bpf_enabled(CGROUP_GETSOCKOPT))			       \

		get_user(__ret, optlen);				       \

		copy_from_sockptr(&__ret, optlen, sizeof(int));		       \

	__ret;								       \

})

include/net/sock.h

+2 −2
Original line number Diff line number Diff line
@@ -1869,11 +1869,11 @@ int sock_setsockopt(struct socket *sock, int level, int op, 
		    sockptr_t optval, unsigned int optlen);

int do_sock_setsockopt(struct socket *sock, bool compat, int level,

		       int optname, sockptr_t optval, int optlen);

int do_sock_getsockopt(struct socket *sock, bool compat, int level,

		       int optname, sockptr_t optval, sockptr_t 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,

		   bool timeval, bool time32);

struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,

net/core/sock.c

+0 −8
Original line number Diff line number Diff line
@@ -2010,14 +2010,6 @@ int sk_getsockopt(struct sock *sk, int level, int optname, 
	return 0;

}



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

		    char __user *optval, int __user *optlen)

{

	return sk_getsockopt(sock->sk, level, optname,

			     USER_SOCKPTR(optval),

			     USER_SOCKPTR(optlen));

}



/*

 * Initialize an sk_lock.

 *

net/socket.c

+41 −23
Original line number Diff line number Diff line
@@ -2333,6 +2333,43 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname, 
INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level,

							 int optname));



int do_sock_getsockopt(struct socket *sock, bool compat, int level,

		       int optname, sockptr_t optval, sockptr_t optlen)

{

	int max_optlen __maybe_unused;

	const struct proto_ops *ops;

	int err;



	err = security_socket_getsockopt(sock, level, optname);

	if (err)

		return err;



	if (!compat)

		max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);



	ops = READ_ONCE(sock->ops);

	if (level == SOL_SOCKET) {

		err = sk_getsockopt(sock->sk, level, optname, optval, optlen);

	} else if (unlikely(!ops->getsockopt)) {

		err = -EOPNOTSUPP;

	} else {

		if (WARN_ONCE(optval.is_kernel || optlen.is_kernel,

			      "Invalid argument type"))

			return -EOPNOTSUPP;



		err = ops->getsockopt(sock, level, optname, optval.user,

				      optlen.user);

	}



	if (!compat)

		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,

						     optval, optlen, max_optlen,

						     err);



	return err;

}

EXPORT_SYMBOL(do_sock_getsockopt);



/*

 *	Get a socket option. Because we don't know the option lengths we have

 *	to pass a user mode parameter for the protocols to sort out.
@@ -2340,37 +2377,18 @@ INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level, 
int __sys_getsockopt(int fd, int level, int optname, char __user *optval,

		int __user *optlen)

{

	int max_optlen __maybe_unused;

	const struct proto_ops *ops;

	int err, fput_needed;

	struct socket *sock;

	bool compat;



	sock = sockfd_lookup_light(fd, &err, &fput_needed);

	if (!sock)

		return err;



	err = security_socket_getsockopt(sock, level, optname);

	if (err)

		goto out_put;

	compat = in_compat_syscall();

	err = do_sock_getsockopt(sock, compat, level, optname,

				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));



	if (!in_compat_syscall())

		max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);



	ops = READ_ONCE(sock->ops);

	if (level == SOL_SOCKET)

		err = sock_getsockopt(sock, level, optname, optval, optlen);

	else if (unlikely(!ops->getsockopt))

		err = -EOPNOTSUPP;

	else

		err = ops->getsockopt(sock, level, optname, optval,

					    optlen);



	if (!in_compat_syscall())

		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,

						     USER_SOCKPTR(optval),

						     USER_SOCKPTR(optlen),

						     max_optlen, err);

out_put:

	fput_light(sock->file, fput_needed);

	return err;

}