diff options
Diffstat (limited to 'net/bluetooth/l2cap_core.c')
| -rw-r--r-- | net/bluetooth/l2cap_core.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 40daa38276f3..805c752ac0a9 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -3520,12 +3520,28 @@ done: /* Configure output options and let the other side know * which ones we don't like. */ - /* If MTU is not provided in configure request, use the most recently - * explicitly or implicitly accepted value for the other direction, - * or the default value. + /* If MTU is not provided in configure request, try adjusting it + * to the current output MTU if it has been set + * + * Bluetooth Core 6.1, Vol 3, Part A, Section 4.5 + * + * Each configuration parameter value (if any is present) in an + * L2CAP_CONFIGURATION_RSP packet reflects an ‘adjustment’ to a + * configuration parameter value that has been sent (or, in case + * of default values, implied) in the corresponding + * L2CAP_CONFIGURATION_REQ packet. */ - if (mtu == 0) - mtu = chan->imtu ? chan->imtu : L2CAP_DEFAULT_MTU; + if (!mtu) { + /* Only adjust for ERTM channels as for older modes the + * remote stack may not be able to detect that the + * adjustment causing it to silently drop packets. + */ + if (chan->mode == L2CAP_MODE_ERTM && + chan->omtu && chan->omtu != L2CAP_DEFAULT_MTU) + mtu = chan->omtu; + else + mtu = L2CAP_DEFAULT_MTU; + } if (mtu < L2CAP_DEFAULT_MIN_MTU) result = L2CAP_CONF_UNACCEPT; |