Bluetooth: Add L2CAP RFC option if ERTM is enabled

When trying to establish a connection with Enhanced Retransmission mode
enabled, the RFC option needs to be added to the configuration.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 20 insertions, 3 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 8a59e57d9df1..7ce1a24735c8 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1743,12 +1743,29 @@ static int l2cap_build_conf_req(struct sock *sk, void *data)
 {
         struct l2cap_pinfo *pi = l2cap_pi(sk);
         struct l2cap_conf_req *req = data;
+        struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
         void *ptr = req->data;
 
         BT_DBG("sk %p", sk);
 
-        if (pi->imtu != L2CAP_DEFAULT_MTU)
-                l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
+        switch (pi->mode) {
+        case L2CAP_MODE_BASIC:
+                if (pi->imtu != L2CAP_DEFAULT_MTU)
+                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
+                break;
+
+        case L2CAP_MODE_ERTM:
+                rfc.mode            = L2CAP_MODE_ERTM;
+                rfc.txwin_size      = L2CAP_DEFAULT_RX_WINDOW;
+                rfc.max_transmit    = L2CAP_DEFAULT_MAX_RECEIVE;
+                rfc.retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
+                rfc.monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
+                rfc.max_pdu_size    = cpu_to_le16(L2CAP_DEFAULT_MAX_RX_APDU);
+
+                l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
+                                        sizeof(rfc), (unsigned long) &rfc);
+                break;
+        }
 
         /* FIXME: Need actual value of the flush timeout */
         //if (flush_to != L2CAP_DEFAULT_FLUSH_TO)
@@ -1828,7 +1845,7 @@ static int l2cap_parse_conf_req(struct sock *sk, void *data)
                         rfc.mode = L2CAP_MODE_BASIC;
 
                         l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
-                                                sizeof(rfc), (unsigned long) &rfc);
+                                        sizeof(rfc), (unsigned long) &rfc);
                 }
         }