[PATCH v4 03/10] net/socket: Break down __sys_setsockopt

Breno Leitao
2023-09-04T16:25:39Z

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

do_sock_setsockopt() will be called by io_uring setsockopt() command
operation in the following patch.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
---
include/net/sock.h | 2 ++
net/socket.c | 39 +++++++++++++++++++++++++--------------
2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 11d503417591..b059f9272303 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1861,6 +1861,8 @@ 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);
+int do_sock_setsockopt(struct socket *sock, bool compat, int level,
+ int optname, sockptr_t optval, int optlen);

int sk_getsockopt(struct sock *sk, int level, int optname,
sockptr_t optval, sockptr_t optlen);
diff --git a/net/socket.c b/net/socket.c
index 9ec9a8a07c0e..3bf29a27653f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2261,31 +2261,21 @@ static bool sock_use_custom_sol_socket(const struct socket *sock)
return test_bit(SOCK_CUSTOM_SOCKOPT, &sock->flags);
}

-/*
- * Set a socket option. Because we don't know the option lengths we have
- * to pass the user mode parameter for the protocols to sort out.
- */
-int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
- int optlen)
+int do_sock_setsockopt(struct socket *sock, bool compat, int level,
+ int optname, sockptr_t optval, int optlen)
{
- sockptr_t optval = USER_SOCKPTR(user_optval);
const struct proto_ops *ops;
char *kernel_optval = NULL;
- int err, fput_needed;
- struct socket *sock;
+ int err;

if (optlen < 0)
return -EINVAL;

- sock = sockfd_lookup_light(fd, &err, &fput_needed);
- if (!sock)
- return err;
-
err = security_socket_setsockopt(sock, level, optname);
if (err)
goto out_put;

- if (!in_compat_syscall())
+ if (!compat)
err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
optval, &optlen,
&kernel_optval);
@@ -2308,6 +2298,27 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
optlen);
kfree(kernel_optval);
out_put:
+ return err;
+}
+EXPORT_SYMBOL(do_sock_setsockopt);
+
+/* Set a socket option. Because we don't know the option lengths we have
+ * to pass the user mode parameter for the protocols to sort out.
+ */
+int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
+ int optlen)
+{
+ sockptr_t optval = USER_SOCKPTR(user_optval);
+ bool compat = in_compat_syscall();
+ int err, fput_needed;
+ struct socket *sock;
+
+ sock = sockfd_lookup_light(fd, &err, &fput_needed);
+ if (!sock)
+ return err;
+
+ err = do_sock_setsockopt(sock, compat, level, optname, optval, optlen);
+
fput_light(sock->file, fput_needed);
return err;
}
--
2.34.1