diff options
Diffstat (limited to 'net/bluetooth/l2cap_core.c')
| -rw-r--r-- | net/bluetooth/l2cap_core.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index a5bde5db58efc..805c752ac0a9d 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -3415,7 +3415,7 @@ static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC }; struct l2cap_conf_efs efs; u8 remote_efs = 0; - u16 mtu = L2CAP_DEFAULT_MTU; + u16 mtu = 0; u16 result = L2CAP_CONF_SUCCESS; u16 size; @@ -3520,6 +3520,29 @@ done: /* Configure output options and let the other side know * which ones we don't like. */ + /* 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) { + /* 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; else { |