[PATCH net-next v2 2/6] Bluetooth: hci_sock: convert to getsockopt_iter

[Breno Leitao <leitao@debian.org>]

Convert HCI socket's getsockopt implementation to use the new
getsockopt_iter callback with sockopt_t.

Key changes:
- Replace (char __user *optval, int __user *optlen) with sockopt_t *sopt
- Use sopt->optlen for buffer length (input)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- Add linux/uio.h for copy_to_iter()

The sockopt_t parameter is named sopt rather than opt to avoid
collision with the existing local int opt used by HCI_DATA_DIR and
HCI_TIME_STAMP.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/bluetooth/hci_sock.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 1823c06ba8940..61fec674a2078 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -27,6 +27,7 @@
 #include <linux/export.h>
 #include <linux/utsname.h>
 #include <linux/sched.h>
+#include <linux/uio.h>
 #include <linux/unaligned.h>
 
 #include <net/bluetooth/bluetooth.h>
@@ -2063,7 +2064,7 @@ static int hci_sock_setsockopt(struct socket *sock, int level, int optname,
 }
 
 static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname,
-				   char __user *optval, int __user *optlen)
+				   sockopt_t *sopt)
 {
 	struct hci_ufilter uf;
 	struct sock *sk = sock->sk;
@@ -2071,8 +2072,7 @@ static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname,
 
 	BT_DBG("sk %p, opt %d", sk, optname);
 
-	if (get_user(len, optlen))
-		return -EFAULT;
+	len = sopt->optlen;
 
 	lock_sock(sk);
 
@@ -2088,7 +2088,8 @@ static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname,
 		else
 			opt = 0;
 
-		if (put_user(opt, (int __user *)optval))
+		if (copy_to_iter(&opt, sizeof(opt), &sopt->iter_out) !=
+		    sizeof(opt))
 			err = -EFAULT;
 		break;
 
@@ -2098,7 +2099,8 @@ static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname,
 		else
 			opt = 0;
 
-		if (put_user(opt, (int __user *)optval))
+		if (copy_to_iter(&opt, sizeof(opt), &sopt->iter_out) !=
+		    sizeof(opt))
 			err = -EFAULT;
 		break;
 
@@ -2114,7 +2116,7 @@ static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname,
 		}
 
 		len = min_t(unsigned int, len, sizeof(uf));
-		if (copy_to_user(optval, &uf, len))
+		if (copy_to_iter(&uf, len, &sopt->iter_out) != len)
 			err = -EFAULT;
 		break;
 
@@ -2129,16 +2131,16 @@ static int hci_sock_getsockopt_old(struct socket *sock, int level, int optname,
 }
 
 static int hci_sock_getsockopt(struct socket *sock, int level, int optname,
-			       char __user *optval, int __user *optlen)
+			       sockopt_t *sopt)
 {
 	struct sock *sk = sock->sk;
 	int err = 0;
+	u16 mtu;
 
 	BT_DBG("sk %p, opt %d", sk, optname);
 
 	if (level == SOL_HCI)
-		return hci_sock_getsockopt_old(sock, level, optname, optval,
-					       optlen);
+		return hci_sock_getsockopt_old(sock, level, optname, sopt);
 
 	if (level != SOL_BLUETOOTH)
 		return -ENOPROTOOPT;
@@ -2148,7 +2150,9 @@ static int hci_sock_getsockopt(struct socket *sock, int level, int optname,
 	switch (optname) {
 	case BT_SNDMTU:
 	case BT_RCVMTU:
-		if (put_user(hci_pi(sk)->mtu, (u16 __user *)optval))
+		mtu = hci_pi(sk)->mtu;
+		if (copy_to_iter(&mtu, sizeof(mtu), &sopt->iter_out) !=
+		    sizeof(mtu))
 			err = -EFAULT;
 		break;
 
@@ -2185,7 +2189,7 @@ static const struct proto_ops hci_sock_ops = {
 	.listen		= sock_no_listen,
 	.shutdown	= sock_no_shutdown,
 	.setsockopt	= hci_sock_setsockopt,
-	.getsockopt	= hci_sock_getsockopt,
+	.getsockopt_iter = hci_sock_getsockopt,
 	.connect	= sock_no_connect,
 	.socketpair	= sock_no_socketpair,
 	.accept		= sock_no_accept,

-- 
2.53.0-Meta