net/socket: Break down __sys_setsockopt

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>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231016134750.1381153-4-leitao@debian.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/net/sock.h b/include/net/sock.h
index b770261fbdaf59d4d1c0b30adb2592c56442e9e3..24fbf71823868b66e6ba2e8540e33c6dfbf38dba 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1867,6 +1867,8 @@ 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 9a43f6e850c72e28951203855e429e8bd6201ca7..63be25d762f6bc86fa08bec08a62512b8c8ca442 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -2262,31 +2262,21 @@ 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);
@@ -2309,6 +2299,27 @@ 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;
 }