Bluetooth: Replace RFCOMM link mode with security level

Change the RFCOMM internals to use the new security levels and remove
the link mode details.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/rfcomm.h

@@ -183,8 +183,8 @@ struct rfcomm_dlc {
 	u8            remote_v24_sig;
 	u8            mscex;
 	u8            out;
-
-	u32           link_mode;
+	u8            sec_level;
+	u8            role_switch;
 	u32           defer_setup;
 
 	uint          mtu;
@@ -307,7 +307,8 @@ struct rfcomm_pinfo {
 	struct bt_sock bt;
 	struct rfcomm_dlc   *dlc;
 	u8     channel;
-	u32    link_mode;
+	u8     sec_level;
+	u8     role_switch;
 };
 
 int  rfcomm_init_sockets(void);

net/bluetooth/rfcomm/core.c

@@ -223,21 +223,11 @@ static int rfcomm_l2sock_create(struct socket **sock)
 	return err;
 }
 
-static inline int rfcomm_check_link_mode(struct rfcomm_dlc *d)
+static inline int rfcomm_check_security(struct rfcomm_dlc *d)
 {
 	struct sock *sk = d->session->sock->sk;
-	struct l2cap_conn *conn = l2cap_pi(sk)->conn;
 
-	if (d->link_mode & RFCOMM_LM_SECURE)
-		return hci_conn_security(conn->hcon, BT_SECURITY_HIGH);
-
-	if (d->link_mode & RFCOMM_LM_ENCRYPT)
-		return hci_conn_security(conn->hcon, BT_SECURITY_MEDIUM);
-
-	if (d->link_mode & RFCOMM_LM_AUTH)
-		return hci_conn_security(conn->hcon, BT_SECURITY_LOW);
-
-	return 1;
+	return hci_conn_security(l2cap_pi(sk)->conn->hcon, d->sec_level);
 }
 
 /* ---- RFCOMM DLCs ---- */
@@ -390,7 +380,7 @@ static int __rfcomm_dlc_open(struct rfcomm_dlc *d, bdaddr_t *src, bdaddr_t *dst,
 	d->cfc = (s->cfc == RFCOMM_CFC_UNKNOWN) ? 0 : s->cfc;
 
 	if (s->state == BT_CONNECTED) {
-		if (rfcomm_check_link_mode(d))
+		if (rfcomm_check_security(d))
 			rfcomm_send_pn(s, 1, d);
 		else
 			set_bit(RFCOMM_AUTH_PENDING, &d->flags);
@@ -1192,7 +1182,7 @@ void rfcomm_dlc_accept(struct rfcomm_dlc *d)
 	d->state_change(d, 0);
 	rfcomm_dlc_unlock(d);
 
-	if (d->link_mode & RFCOMM_LM_MASTER)
+	if (d->role_switch)
 		hci_conn_switch_role(l2cap_pi(sk)->conn->hcon, 0x00);
 
 	rfcomm_send_msc(d->session, 1, d->dlci, d->v24_sig);
@@ -1200,7 +1190,7 @@ void rfcomm_dlc_accept(struct rfcomm_dlc *d)
 
 static void rfcomm_check_accept(struct rfcomm_dlc *d)
 {
-	if (rfcomm_check_link_mode(d)) {
+	if (rfcomm_check_security(d)) {
 		if (d->defer_setup) {
 			set_bit(RFCOMM_DEFER_SETUP, &d->flags);
 			rfcomm_dlc_set_timer(d, RFCOMM_AUTH_TIMEOUT);
@@ -1660,7 +1650,7 @@ static void rfcomm_process_connect(struct rfcomm_session *s)
 		d = list_entry(p, struct rfcomm_dlc, list);
 		if (d->state == BT_CONFIG) {
 			d->mtu = s->mtu;
-			if (rfcomm_check_link_mode(d)) {
+			if (rfcomm_check_security(d)) {
 				rfcomm_send_pn(s, 1, d);
 			} else {
 				set_bit(RFCOMM_AUTH_PENDING, &d->flags);
@@ -1748,10 +1738,6 @@ static inline void rfcomm_process_dlcs(struct rfcomm_session *s)
 				} else
 					rfcomm_dlc_accept(d);
 			}
-			if (d->link_mode & RFCOMM_LM_SECURE) {
-				struct sock *sk = s->sock->sk;
-				hci_conn_change_link_key(l2cap_pi(sk)->conn->hcon);
-			}
 			continue;
 		} else if (test_and_clear_bit(RFCOMM_AUTH_REJECT, &d->flags)) {
 			rfcomm_dlc_clear_timer(d);
@@ -1994,7 +1980,7 @@ static void rfcomm_security_cfm(struct hci_conn *conn, u8 status, u8 encrypt)
 		d = list_entry(p, struct rfcomm_dlc, list);
 
 		if (!status && encrypt == 0x00 &&
-				(d->link_mode & RFCOMM_LM_ENCRYPT) &&
+				d->sec_level == BT_SECURITY_HIGH &&
 					(d->state == BT_CONNECTED ||
 						d->state == BT_CONFIG)) {
 			__rfcomm_dlc_close(d, ECONNREFUSED);

net/bluetooth/rfcomm/sock.c

@@ -261,14 +261,19 @@ static void rfcomm_sock_init(struct sock *sk, struct sock *parent)
 
 	if (parent) {
 		sk->sk_type = parent->sk_type;
-		pi->link_mode = rfcomm_pi(parent)->link_mode;
 		pi->dlc->defer_setup = bt_sk(parent)->defer_setup;
+
+		pi->sec_level = rfcomm_pi(parent)->sec_level;
+		pi->role_switch = rfcomm_pi(parent)->role_switch;
 	} else {
-		pi->link_mode = 0;
 		pi->dlc->defer_setup = 0;
+
+		pi->sec_level = BT_SECURITY_LOW;
+		pi->role_switch = 0;
 	}
 
-	pi->dlc->link_mode = pi->link_mode;
+	pi->dlc->sec_level = pi->sec_level;
+	pi->dlc->role_switch = pi->role_switch;
 }
 
 static struct proto rfcomm_proto = {
@@ -408,7 +413,8 @@ static int rfcomm_sock_connect(struct socket *sock, struct sockaddr *addr, int a
 	bacpy(&bt_sk(sk)->dst, &sa->rc_bdaddr);
 	rfcomm_pi(sk)->channel = sa->rc_channel;
 
-	d->link_mode = rfcomm_pi(sk)->link_mode;
+	d->sec_level = rfcomm_pi(sk)->sec_level;
+	d->role_switch = rfcomm_pi(sk)->role_switch;
 
 	err = rfcomm_dlc_open(d, &bt_sk(sk)->src, &sa->rc_bdaddr, sa->rc_channel);
 	if (!err)
@@ -741,7 +747,14 @@ static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname, char __u
 			break;
 		}
 
-		rfcomm_pi(sk)->link_mode = opt;
+		if (opt & RFCOMM_LM_AUTH)
+			rfcomm_pi(sk)->sec_level = BT_SECURITY_LOW;
+		if (opt & RFCOMM_LM_ENCRYPT)
+			rfcomm_pi(sk)->sec_level = BT_SECURITY_MEDIUM;
+		if (opt & RFCOMM_LM_SECURE)
+			rfcomm_pi(sk)->sec_level = BT_SECURITY_HIGH;
+
+		rfcomm_pi(sk)->role_switch = (opt & RFCOMM_LM_MASTER);
 		break;
 
 	default:
@@ -756,7 +769,8 @@ static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname, char __u
 static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, char __user *optval, int optlen)
 {
 	struct sock *sk = sock->sk;
-	int err = 0;
+	struct bt_security sec;
+	int len, err = 0;
 	u32 opt;
 
 	BT_DBG("sk %p", sk);
@@ -767,6 +781,23 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, c
 	lock_sock(sk);
 
 	switch (optname) {
+	case BT_SECURITY:
+		sec.level = BT_SECURITY_LOW;
+
+		len = min_t(unsigned int, sizeof(sec), optlen);
+		if (copy_from_user((char *) &sec, optval, len)) {
+			err = -EFAULT;
+			break;
+		}
+
+		if (sec.level > BT_SECURITY_HIGH) {
+			err = -EINVAL;
+			break;
+		}
+
+		rfcomm_pi(sk)->sec_level = sec.level;
+		break;
+
 	case BT_DEFER_SETUP:
 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
 			err = -EINVAL;
@@ -796,6 +827,7 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
 	struct sock *l2cap_sk;
 	struct rfcomm_conninfo cinfo;
 	int len, err = 0;
+	u32 opt;
 
 	BT_DBG("sk %p", sk);
 
@@ -806,7 +838,26 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
 
 	switch (optname) {
 	case RFCOMM_LM:
-		if (put_user(rfcomm_pi(sk)->link_mode, (u32 __user *) optval))
+		switch (rfcomm_pi(sk)->sec_level) {
+		case BT_SECURITY_LOW:
+			opt = RFCOMM_LM_AUTH;
+			break;
+		case BT_SECURITY_MEDIUM:
+			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT;
+			break;
+		case BT_SECURITY_HIGH:
+			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
+							RFCOMM_LM_SECURE;
+			break;
+		default:
+			opt = 0;
+			break;
+		}
+
+		if (rfcomm_pi(sk)->role_switch)
+			opt |= RFCOMM_LM_MASTER;
+
+		if (put_user(opt, (u32 __user *) optval))
 			err = -EFAULT;
 		break;
 
@@ -840,6 +891,7 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __u
 static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
 {
 	struct sock *sk = sock->sk;
+	struct bt_security sec;
 	int len, err = 0;
 
 	BT_DBG("sk %p", sk);
@@ -853,6 +905,15 @@ static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, c
 	lock_sock(sk);
 
 	switch (optname) {
+	case BT_SECURITY:
+		sec.level = rfcomm_pi(sk)->sec_level;
+
+		len = min_t(unsigned int, len, sizeof(sec));
+		if (copy_to_user(optval, (char *) &sec, len))
+			err = -EFAULT;
+
+		break;
+
 	case BT_DEFER_SETUP:
 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
 			err = -EINVAL;