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

[Breno Leitao <leitao@debian.org>]

Convert SCO 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 *opt
- Use opt->optlen for buffer length (input) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- Drop the open-coded ptr cursor in BT_CODEC; iter_out advances on
  every copy_to_iter() naturally
- Add linux/uio.h for copy_to_iter()

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/bluetooth/sco.c | 59 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 28 deletions(-)

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index eba44525d41d9..37dcba9edfab6 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -28,6 +28,7 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/sched/signal.h>
+#include <linux/uio.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
@@ -1072,7 +1073,7 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname,
 }
 
 static int sco_sock_getsockopt_old(struct socket *sock, int optname,
-				   char __user *optval, int __user *optlen)
+				   sockopt_t *opt)
 {
 	struct sock *sk = sock->sk;
 	struct sco_options opts;
@@ -1082,8 +1083,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname,
 
 	BT_DBG("sk %p", sk);
 
-	if (get_user(len, optlen))
-		return -EFAULT;
+	len = opt->optlen;
 
 	lock_sock(sk);
 
@@ -1101,7 +1101,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname,
 		BT_DBG("mtu %u", opts.mtu);
 
 		len = min(len, sizeof(opts));
-		if (copy_to_user(optval, (char *)&opts, len))
+		if (copy_to_iter(&opts, len, &opt->iter_out) != len)
 			err = -EFAULT;
 
 		break;
@@ -1119,7 +1119,7 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname,
 		memcpy(cinfo.dev_class, sco_pi(sk)->conn->hcon->dev_class, 3);
 
 		len = min(len, sizeof(cinfo));
-		if (copy_to_user(optval, (char *)&cinfo, len))
+		if (copy_to_iter(&cinfo, len, &opt->iter_out) != len)
 			err = -EFAULT;
 
 		break;
@@ -1134,15 +1134,15 @@ static int sco_sock_getsockopt_old(struct socket *sock, int optname,
 }
 
 static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
-			       char __user *optval, int __user *optlen)
+			       sockopt_t *opt)
 {
 	struct sock *sk = sock->sk;
-	int len, err = 0;
+	int len, val, err = 0;
 	struct bt_voice voice;
 	u32 phys;
 	int buf_len;
 	struct codec_list *c;
-	u8 num_codecs, i, __user *ptr;
+	u8 num_codecs, i;
 	struct hci_dev *hdev;
 	struct hci_codec_caps *caps;
 	struct bt_codec codec;
@@ -1150,10 +1150,9 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 	BT_DBG("sk %p", sk);
 
 	if (level == SOL_SCO)
-		return sco_sock_getsockopt_old(sock, optname, optval, optlen);
+		return sco_sock_getsockopt_old(sock, optname, opt);
 
-	if (get_user(len, optlen))
-		return -EFAULT;
+	len = opt->optlen;
 
 	lock_sock(sk);
 
@@ -1165,8 +1164,9 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 			break;
 		}
 
-		if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
-			     (u32 __user *)optval))
+		val = test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
+		if (copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
+		    sizeof(val))
 			err = -EFAULT;
 
 		break;
@@ -1175,7 +1175,7 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 		voice.setting = sco_pi(sk)->setting;
 
 		len = min_t(unsigned int, len, sizeof(voice));
-		if (copy_to_user(optval, (char *)&voice, len))
+		if (copy_to_iter(&voice, len, &opt->iter_out) != len)
 			err = -EFAULT;
 
 		break;
@@ -1188,13 +1188,15 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 
 		phys = hci_conn_get_phy(sco_pi(sk)->conn->hcon);
 
-		if (put_user(phys, (u32 __user *) optval))
+		if (copy_to_iter(&phys, sizeof(phys), &opt->iter_out) !=
+		    sizeof(phys))
 			err = -EFAULT;
 		break;
 
 	case BT_PKT_STATUS:
-		if (put_user(test_bit(BT_SK_PKT_STATUS, &bt_sk(sk)->flags),
-			     (int __user *)optval))
+		val = test_bit(BT_SK_PKT_STATUS, &bt_sk(sk)->flags);
+		if (copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
+		    sizeof(val))
 			err = -EFAULT;
 		break;
 
@@ -1205,7 +1207,9 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 			break;
 		}
 
-		if (put_user(sco_pi(sk)->conn->mtu, (u32 __user *)optval))
+		val = sco_pi(sk)->conn->mtu;
+		if (copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
+		    sizeof(val))
 			err = -EFAULT;
 		break;
 
@@ -1252,13 +1256,12 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 			hci_dev_put(hdev);
 			return -ENOBUFS;
 		}
-		ptr = optval;
 
-		if (put_user(num_codecs, ptr)) {
+		if (copy_to_iter(&num_codecs, sizeof(num_codecs),
+				 &opt->iter_out) != sizeof(num_codecs)) {
 			hci_dev_put(hdev);
 			return -EFAULT;
 		}
-		ptr += sizeof(num_codecs);
 
 		/* Iterate all the codecs supported over SCO and populate
 		 * codec data
@@ -1275,11 +1278,11 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 			if (err < 0)
 				break;
 			codec.num_caps = c->num_caps;
-			if (copy_to_user(ptr, &codec, sizeof(codec))) {
+			if (copy_to_iter(&codec, sizeof(codec), &opt->iter_out)
+			    != sizeof(codec)) {
 				err = -EFAULT;
 				break;
 			}
-			ptr += sizeof(codec);
 
 			/* find codec capabilities data length */
 			len = 0;
@@ -1289,11 +1292,11 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 			}
 
 			/* copy codec capabilities data */
-			if (len && copy_to_user(ptr, c->caps, len)) {
+			if (len &&
+			    copy_to_iter(c->caps, len, &opt->iter_out) != len) {
 				err = -EFAULT;
 				break;
 			}
-			ptr += len;
 		}
 
 		hci_dev_unlock(hdev);
@@ -1301,8 +1304,8 @@ static int sco_sock_getsockopt(struct socket *sock, int level, int optname,
 
 		lock_sock(sk);
 
-		if (!err && put_user(buf_len, optlen))
-			err = -EFAULT;
+		if (!err)
+			opt->optlen = buf_len;
 
 		break;
 
@@ -1577,7 +1580,7 @@ static const struct proto_ops sco_sock_ops = {
 	.socketpair	= sock_no_socketpair,
 	.shutdown	= sco_sock_shutdown,
 	.setsockopt	= sco_sock_setsockopt,
-	.getsockopt	= sco_sock_getsockopt
+	.getsockopt_iter = sco_sock_getsockopt
 };
 
 static const struct net_proto_family sco_sock_family_ops = {

-- 
2.53.0-Meta