/****************************************************************************** * * Copyright (C) 1999-2012 Broadcom Corporation * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ******************************************************************************/ /****************************************************************************** * * this file contains the functions relating to link management. A "link" * is a connection between this device and another device. Only ACL links * are managed. * ******************************************************************************/ #include #include #include #include #include "device/include/controller.h" #include "bt_common.h" #include "bt_types.h" #include "bt_utils.h" #include "hcimsgs.h" #include "l2cdefs.h" #include "l2c_int.h" #include "l2c_api.h" #include "btu.h" #include "btm_api.h" #include "btm_int.h" #include "btcore/include/bdaddr.h" extern fixed_queue_t *btu_general_alarm_queue; static BOOLEAN l2c_link_send_to_lower (tL2C_LCB *p_lcb, BT_HDR *p_buf); /******************************************************************************* ** ** Function l2c_link_hci_conn_req ** ** Description This function is called when an HCI Connection Request ** event is received. ** ** Returns TRUE, if accept conn ** *******************************************************************************/ BOOLEAN l2c_link_hci_conn_req (BD_ADDR bd_addr) { tL2C_LCB *p_lcb; tL2C_LCB *p_lcb_cur; int xx; BOOLEAN no_links; /* See if we have a link control block for the remote device */ p_lcb = l2cu_find_lcb_by_bd_addr (bd_addr, BT_TRANSPORT_BR_EDR); /* If we don't have one, create one and accept the connection. */ if (!p_lcb) { p_lcb = l2cu_allocate_lcb (bd_addr, FALSE, BT_TRANSPORT_BR_EDR); if (!p_lcb) { btsnd_hcic_reject_conn (bd_addr, HCI_ERR_HOST_REJECT_RESOURCES); L2CAP_TRACE_ERROR ("L2CAP failed to allocate LCB"); return FALSE; } no_links = TRUE; /* If we already have connection, accept as a master */ for (xx = 0, p_lcb_cur = &l2cb.lcb_pool[0]; xx < MAX_L2CAP_LINKS; xx++, p_lcb_cur++) { if (p_lcb_cur == p_lcb) continue; if (p_lcb_cur->in_use) { no_links = FALSE; p_lcb->link_role = HCI_ROLE_MASTER; break; } } if (no_links) { if (!btm_dev_support_switch (bd_addr)) p_lcb->link_role = HCI_ROLE_SLAVE; else p_lcb->link_role = l2cu_get_conn_role(p_lcb); } /* Tell the other side we accept the connection */ btsnd_hcic_accept_conn (bd_addr, p_lcb->link_role); p_lcb->link_state = LST_CONNECTING; /* Start a timer waiting for connect complete */ alarm_set_on_queue(p_lcb->l2c_lcb_timer, L2CAP_LINK_CONNECT_TIMEOUT_MS, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); return (TRUE); } /* We already had a link control block to the guy. Check what state it is in */ if ((p_lcb->link_state == LST_CONNECTING) || (p_lcb->link_state == LST_CONNECT_HOLDING)) { /* Connection collision. Accept the connection anyways. */ if (!btm_dev_support_switch (bd_addr)) p_lcb->link_role = HCI_ROLE_SLAVE; else p_lcb->link_role = l2cu_get_conn_role(p_lcb); btsnd_hcic_accept_conn (bd_addr, p_lcb->link_role); p_lcb->link_state = LST_CONNECTING; return (TRUE); } else if (p_lcb->link_state == LST_DISCONNECTING) { /* In disconnecting state, reject the connection. */ btsnd_hcic_reject_conn (bd_addr, HCI_ERR_HOST_REJECT_DEVICE); } else { L2CAP_TRACE_ERROR("L2CAP got conn_req while connected (state:%d). Reject it", p_lcb->link_state); /* Reject the connection with ACL Connection Already exist reason */ btsnd_hcic_reject_conn (bd_addr, HCI_ERR_CONNECTION_EXISTS); } return (FALSE); } /******************************************************************************* ** ** Function l2c_link_hci_conn_comp ** ** Description This function is called when an HCI Connection Complete ** event is received. ** ** Returns void ** *******************************************************************************/ BOOLEAN l2c_link_hci_conn_comp (UINT8 status, UINT16 handle, BD_ADDR p_bda) { tL2C_CONN_INFO ci; tL2C_LCB *p_lcb; tL2C_CCB *p_ccb; tBTM_SEC_DEV_REC *p_dev_info = NULL; btm_acl_update_busy_level (BTM_BLI_PAGE_DONE_EVT); /* Save the parameters */ ci.status = status; memcpy (ci.bd_addr, p_bda, BD_ADDR_LEN); /* See if we have a link control block for the remote device */ p_lcb = l2cu_find_lcb_by_bd_addr (ci.bd_addr, BT_TRANSPORT_BR_EDR); /* If we don't have one, this is an error */ if (!p_lcb) { L2CAP_TRACE_WARNING ("L2CAP got conn_comp for unknown BD_ADDR"); return (FALSE); } if (p_lcb->link_state != LST_CONNECTING) { L2CAP_TRACE_ERROR ("L2CAP got conn_comp in bad state: %d status: 0x%d", p_lcb->link_state, status); if (status != HCI_SUCCESS) l2c_link_hci_disc_comp (p_lcb->handle, status); return (FALSE); } /* Save the handle */ p_lcb->handle = handle; if (ci.status == HCI_SUCCESS) { /* Connected OK. Change state to connected */ p_lcb->link_state = LST_CONNECTED; /* Get the peer information if the l2cap flow-control/rtrans is supported */ l2cu_send_peer_info_req (p_lcb, L2CAP_EXTENDED_FEATURES_INFO_TYPE); /* Tell BTM Acl management about the link */ if ((p_dev_info = btm_find_dev (p_bda)) != NULL) btm_acl_created (ci.bd_addr, p_dev_info->dev_class, p_dev_info->sec_bd_name, handle, p_lcb->link_role, BT_TRANSPORT_BR_EDR); else btm_acl_created (ci.bd_addr, NULL, NULL, handle, p_lcb->link_role, BT_TRANSPORT_BR_EDR); BTM_SetLinkSuperTout (ci.bd_addr, btm_cb.btm_def_link_super_tout); /* If dedicated bonding do not process any further */ if (p_lcb->is_bonding) { if (l2cu_start_post_bond_timer(handle)) return (TRUE); } /* Update the timeouts in the hold queue */ l2c_process_held_packets(FALSE); alarm_cancel(p_lcb->l2c_lcb_timer); /* For all channels, send the event through their FSMs */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) { l2c_csm_execute (p_ccb, L2CEVT_LP_CONNECT_CFM, &ci); } if (p_lcb->p_echo_rsp_cb) { l2cu_send_peer_echo_req (p_lcb, NULL, 0); alarm_set_on_queue(p_lcb->l2c_lcb_timer, L2CAP_ECHO_RSP_TIMEOUT_MS, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); } else if (!p_lcb->ccb_queue.p_first_ccb) { period_ms_t timeout_ms = L2CAP_LINK_STARTUP_TOUT * 1000; alarm_set_on_queue(p_lcb->l2c_lcb_timer, timeout_ms, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); } } /* Max number of acl connections. */ /* If there's an lcb disconnecting set this one to holding */ else if ((ci.status == HCI_ERR_MAX_NUM_OF_CONNECTIONS) && l2cu_lcb_disconnecting()) { p_lcb->link_state = LST_CONNECT_HOLDING; p_lcb->handle = HCI_INVALID_HANDLE; } else { /* Just in case app decides to try again in the callback context */ p_lcb->link_state = LST_DISCONNECTING; /* Connection failed. For all channels, send the event through */ /* their FSMs. The CCBs should remove themselves from the LCB */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; ) { tL2C_CCB *pn = p_ccb->p_next_ccb; l2c_csm_execute (p_ccb, L2CEVT_LP_CONNECT_CFM_NEG, &ci); p_ccb = pn; } p_lcb->disc_reason = status; /* Release the LCB */ if (p_lcb->ccb_queue.p_first_ccb == NULL) l2cu_release_lcb (p_lcb); else /* there are any CCBs remaining */ { if (ci.status == HCI_ERR_CONNECTION_EXISTS) { /* we are in collision situation, wait for connecttion request from controller */ p_lcb->link_state = LST_CONNECTING; } else { l2cu_create_conn(p_lcb, BT_TRANSPORT_BR_EDR); } } } return (TRUE); } /******************************************************************************* ** ** Function l2c_link_sec_comp ** ** Description This function is called when required security procedures ** are completed. ** ** Returns void ** *******************************************************************************/ void l2c_link_sec_comp (BD_ADDR p_bda, tBT_TRANSPORT transport, void *p_ref_data, UINT8 status) { tL2C_CONN_INFO ci; tL2C_LCB *p_lcb; tL2C_CCB *p_ccb; tL2C_CCB *p_next_ccb; UINT8 event; UNUSED(transport); L2CAP_TRACE_DEBUG ("l2c_link_sec_comp: %d, 0x%x", status, p_ref_data); if (status == BTM_SUCCESS_NO_SECURITY) status = BTM_SUCCESS; /* Save the parameters */ ci.status = status; memcpy (ci.bd_addr, p_bda, BD_ADDR_LEN); p_lcb = l2cu_find_lcb_by_bd_addr (p_bda, transport); /* If we don't have one, this is an error */ if (!p_lcb) { L2CAP_TRACE_WARNING ("L2CAP got sec_comp for unknown BD_ADDR"); return; } /* Match p_ccb with p_ref_data returned by sec manager */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_next_ccb) { p_next_ccb = p_ccb->p_next_ccb; if (p_ccb == p_ref_data) { switch(status) { case BTM_SUCCESS: event = L2CEVT_SEC_COMP; break; case BTM_DELAY_CHECK: /* start a timer - encryption change not received before L2CAP connect req */ alarm_set_on_queue(p_ccb->l2c_ccb_timer, L2CAP_DELAY_CHECK_SM4_TIMEOUT_MS, l2c_ccb_timer_timeout, p_ccb, btu_general_alarm_queue); return; default: event = L2CEVT_SEC_COMP_NEG; } l2c_csm_execute (p_ccb, event, &ci); break; } } } /******************************************************************************* ** ** Function l2c_link_hci_disc_comp ** ** Description This function is called when an HCI Disconnect Complete ** event is received. ** ** Returns TRUE if the link is known about, else FALSE ** *******************************************************************************/ BOOLEAN l2c_link_hci_disc_comp (UINT16 handle, UINT8 reason) { tL2C_LCB *p_lcb; tL2C_CCB *p_ccb; BOOLEAN status = TRUE; BOOLEAN lcb_is_free = TRUE; tBT_TRANSPORT transport = BT_TRANSPORT_BR_EDR; /* See if we have a link control block for the connection */ p_lcb = l2cu_find_lcb_by_handle (handle); /* If we don't have one, maybe an SCO link. Send to MM */ if (!p_lcb) { status = FALSE; } else { /* There can be a case when we rejected PIN code authentication */ /* otherwise save a new reason */ if (btm_cb.acl_disc_reason != HCI_ERR_HOST_REJECT_SECURITY) btm_cb.acl_disc_reason = reason; p_lcb->disc_reason = btm_cb.acl_disc_reason; /* Just in case app decides to try again in the callback context */ p_lcb->link_state = LST_DISCONNECTING; #if (BLE_INCLUDED == TRUE) /* Check for BLE and handle that differently */ if (p_lcb->transport == BT_TRANSPORT_LE) btm_ble_update_link_topology_mask(p_lcb->link_role, FALSE); #endif /* Link is disconnected. For all channels, send the event through */ /* their FSMs. The CCBs should remove themselves from the LCB */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; ) { tL2C_CCB *pn = p_ccb->p_next_ccb; /* Keep connect pending control block (if exists) * Possible Race condition when a reconnect occurs * on the channel during a disconnect of link. This * ccb will be automatically retried after link disconnect * arrives */ if (p_ccb != p_lcb->p_pending_ccb) { l2c_csm_execute (p_ccb, L2CEVT_LP_DISCONNECT_IND, &reason); } p_ccb = pn; } #if (BTM_SCO_INCLUDED == TRUE) #if (BLE_INCLUDED == TRUE) if (p_lcb->transport == BT_TRANSPORT_BR_EDR) #endif /* Tell SCO management to drop any SCOs on this ACL */ btm_sco_acl_removed (p_lcb->remote_bd_addr); #endif /* If waiting for disconnect and reconnect is pending start the reconnect now race condition where layer above issued connect request on link that was disconnecting */ if (p_lcb->ccb_queue.p_first_ccb != NULL || p_lcb->p_pending_ccb) { L2CAP_TRACE_DEBUG("l2c_link_hci_disc_comp: Restarting pending ACL request"); transport = p_lcb->transport; #if BLE_INCLUDED == TRUE /* for LE link, always drop and re-open to ensure to get LE remote feature */ if (p_lcb->transport == BT_TRANSPORT_LE) { l2cb.is_ble_connecting = FALSE; btm_acl_removed (p_lcb->remote_bd_addr, p_lcb->transport); /* Release any held buffers */ BT_HDR *p_buf; while (!list_is_empty(p_lcb->link_xmit_data_q)) { p_buf = list_front(p_lcb->link_xmit_data_q); list_remove(p_lcb->link_xmit_data_q, p_buf); osi_free(p_buf); } } else #endif { #if (L2CAP_NUM_FIXED_CHNLS > 0) /* If we are going to re-use the LCB without dropping it, release all fixed channels here */ int xx; for (xx = 0; xx < L2CAP_NUM_FIXED_CHNLS; xx++) { if (p_lcb->p_fixed_ccbs[xx] && p_lcb->p_fixed_ccbs[xx] != p_lcb->p_pending_ccb) { #if BLE_INCLUDED == TRUE (*l2cb.fixed_reg[xx].pL2CA_FixedConn_Cb)(xx + L2CAP_FIRST_FIXED_CHNL, p_lcb->remote_bd_addr, FALSE, p_lcb->disc_reason, p_lcb->transport); #else (*l2cb.fixed_reg[xx].pL2CA_FixedConn_Cb)(xx + L2CAP_FIRST_FIXED_CHNL, p_lcb->remote_bd_addr, FALSE, p_lcb->disc_reason, BT_TRANSPORT_BR_EDR); #endif if (p_lcb->p_fixed_ccbs[xx] == NULL) { bdstr_t bd_addr_str = {0}; L2CAP_TRACE_ERROR("%s: unexpected p_fixed_ccbs[%d] is NULL remote_bd_addr = %s p_lcb = %p in_use = %d link_state = %d handle = %d link_role = %d is_bonding = %d disc_reason = %d transport = %d", __func__, xx, bdaddr_to_string((bt_bdaddr_t *)&p_lcb->remote_bd_addr, bd_addr_str, sizeof(bd_addr_str)), p_lcb, p_lcb->in_use, p_lcb->link_state, p_lcb->handle, p_lcb->link_role, p_lcb->is_bonding, p_lcb->disc_reason, p_lcb->transport); } assert(p_lcb->p_fixed_ccbs[xx] != NULL); l2cu_release_ccb (p_lcb->p_fixed_ccbs[xx]); p_lcb->p_fixed_ccbs[xx] = NULL; } } #endif } if (l2cu_create_conn(p_lcb, transport)) lcb_is_free = FALSE; /* still using this lcb */ } p_lcb->p_pending_ccb = NULL; /* Release the LCB */ if (lcb_is_free) l2cu_release_lcb (p_lcb); } /* Now that we have a free acl connection, see if any lcbs are pending */ if (lcb_is_free && ((p_lcb = l2cu_find_lcb_by_state(LST_CONNECT_HOLDING)) != NULL)) { /* we found one-- create a connection */ l2cu_create_conn(p_lcb, BT_TRANSPORT_BR_EDR); } return status; } /******************************************************************************* ** ** Function l2c_link_hci_qos_violation ** ** Description This function is called when an HCI QOS Violation ** event is received. ** ** Returns TRUE if the link is known about, else FALSE ** *******************************************************************************/ BOOLEAN l2c_link_hci_qos_violation (UINT16 handle) { tL2C_LCB *p_lcb; tL2C_CCB *p_ccb; /* See if we have a link control block for the connection */ p_lcb = l2cu_find_lcb_by_handle (handle); /* If we don't have one, maybe an SCO link. */ if (!p_lcb) return (FALSE); /* For all channels, tell the upper layer about it */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) { if (p_ccb->p_rcb->api.pL2CA_QoSViolationInd_Cb) l2c_csm_execute (p_ccb, L2CEVT_LP_QOS_VIOLATION_IND, NULL); } return (TRUE); } /******************************************************************************* ** ** Function l2c_link_timeout ** ** Description This function is called when a link timer expires ** ** Returns void ** *******************************************************************************/ void l2c_link_timeout (tL2C_LCB *p_lcb) { tL2C_CCB *p_ccb; tBTM_STATUS rc; L2CAP_TRACE_EVENT ("L2CAP - l2c_link_timeout() link state %d first CCB %p is_bonding:%d", p_lcb->link_state, p_lcb->ccb_queue.p_first_ccb, p_lcb->is_bonding); /* If link was connecting or disconnecting, clear all channels and drop the LCB */ if ((p_lcb->link_state == LST_CONNECTING_WAIT_SWITCH) || (p_lcb->link_state == LST_CONNECTING) || (p_lcb->link_state == LST_CONNECT_HOLDING) || (p_lcb->link_state == LST_DISCONNECTING)) { p_lcb->p_pending_ccb = NULL; /* For all channels, send a disconnect indication event through */ /* their FSMs. The CCBs should remove themselves from the LCB */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; ) { tL2C_CCB *pn = p_ccb->p_next_ccb; l2c_csm_execute (p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL); p_ccb = pn; } #if (BLE_INCLUDED == TRUE) if (p_lcb->link_state == LST_CONNECTING && l2cb.is_ble_connecting == TRUE) { L2CA_CancelBleConnectReq(l2cb.ble_connecting_bda); } #endif /* Release the LCB */ l2cu_release_lcb (p_lcb); } /* If link is connected, check for inactivity timeout */ if (p_lcb->link_state == LST_CONNECTED) { /* Check for ping outstanding */ if (p_lcb->p_echo_rsp_cb) { tL2CA_ECHO_RSP_CB *p_cb = p_lcb->p_echo_rsp_cb; /* Zero out the callback in case app immediately calls us again */ p_lcb->p_echo_rsp_cb = NULL; (*p_cb) (L2CAP_PING_RESULT_NO_RESP); L2CAP_TRACE_WARNING ("L2CAP - ping timeout"); /* For all channels, send a disconnect indication event through */ /* their FSMs. The CCBs should remove themselves from the LCB */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; ) { tL2C_CCB *pn = p_ccb->p_next_ccb; l2c_csm_execute (p_ccb, L2CEVT_LP_DISCONNECT_IND, NULL); p_ccb = pn; } } /* If no channels in use, drop the link. */ if (!p_lcb->ccb_queue.p_first_ccb) { period_ms_t timeout_ms; bool start_timeout = true; rc = btm_sec_disconnect (p_lcb->handle, HCI_ERR_PEER_USER); if (rc == BTM_CMD_STORED) { /* Security Manager will take care of disconnecting, state will be updated at that time */ start_timeout = false; } else if (rc == BTM_CMD_STARTED) { p_lcb->link_state = LST_DISCONNECTING; timeout_ms = L2CAP_LINK_DISCONNECT_TIMEOUT_MS; } else if (rc == BTM_SUCCESS) { l2cu_process_fixed_disc_cback(p_lcb); /* BTM SEC will make sure that link is release (probably after pairing is done) */ p_lcb->link_state = LST_DISCONNECTING; start_timeout = false; } else if (rc == BTM_BUSY) { /* BTM is still executing security process. Let lcb stay as connected */ start_timeout = false; } else if ((p_lcb->is_bonding) && (btsnd_hcic_disconnect (p_lcb->handle, HCI_ERR_PEER_USER))) { l2cu_process_fixed_disc_cback(p_lcb); p_lcb->link_state = LST_DISCONNECTING; timeout_ms = L2CAP_LINK_DISCONNECT_TIMEOUT_MS; } else { /* probably no buffer to send disconnect */ timeout_ms = BT_1SEC_TIMEOUT_MS; } if (start_timeout) { alarm_set_on_queue(p_lcb->l2c_lcb_timer, timeout_ms, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); } } else { /* Check in case we were flow controlled */ l2c_link_check_send_pkts (p_lcb, NULL, NULL); } } } /******************************************************************************* ** ** Function l2c_info_resp_timer_timeout ** ** Description This function is called when an info request times out ** ** Returns void ** *******************************************************************************/ void l2c_info_resp_timer_timeout(void *data) { tL2C_LCB *p_lcb = (tL2C_LCB *)data; tL2C_CCB *p_ccb; tL2C_CONN_INFO ci; /* If we timed out waiting for info response, just continue using basic if allowed */ if (p_lcb->w4_info_rsp) { /* If waiting for security complete, restart the info response timer */ for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) { if ( (p_ccb->chnl_state == CST_ORIG_W4_SEC_COMP) || (p_ccb->chnl_state == CST_TERM_W4_SEC_COMP) ) { alarm_set_on_queue(p_lcb->info_resp_timer, L2CAP_WAIT_INFO_RSP_TIMEOUT_MS, l2c_info_resp_timer_timeout, p_lcb, btu_general_alarm_queue); return; } } p_lcb->w4_info_rsp = FALSE; /* If link is in process of being brought up */ if ((p_lcb->link_state != LST_DISCONNECTED) && (p_lcb->link_state != LST_DISCONNECTING)) { /* Notify active channels that peer info is finished */ if (p_lcb->ccb_queue.p_first_ccb) { ci.status = HCI_SUCCESS; memcpy (ci.bd_addr, p_lcb->remote_bd_addr, sizeof(BD_ADDR)); for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) { l2c_csm_execute (p_ccb, L2CEVT_L2CAP_INFO_RSP, &ci); } } } } } /******************************************************************************* ** ** Function l2c_link_adjust_allocation ** ** Description This function is called when a link is created or removed ** to calculate the amount of packets each link may send to ** the HCI without an ack coming back. ** ** Currently, this is a simple allocation, dividing the ** number of Controller Packets by the number of links. In ** the future, QOS configuration should be examined. ** ** Returns void ** *******************************************************************************/ void l2c_link_adjust_allocation (void) { UINT16 qq, yy, qq_remainder; tL2C_LCB *p_lcb; UINT16 hi_quota, low_quota; UINT16 num_lowpri_links = 0; UINT16 num_hipri_links = 0; UINT16 controller_xmit_quota = l2cb.num_lm_acl_bufs; UINT16 high_pri_link_quota = L2CAP_HIGH_PRI_MIN_XMIT_QUOTA_A; /* If no links active, reset buffer quotas and controller buffers */ if (l2cb.num_links_active == 0) { l2cb.controller_xmit_window = l2cb.num_lm_acl_bufs; l2cb.round_robin_quota = l2cb.round_robin_unacked = 0; return; } /* First, count the links */ for (yy = 0, p_lcb = &l2cb.lcb_pool[0]; yy < MAX_L2CAP_LINKS; yy++, p_lcb++) { if (p_lcb->in_use) { if (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) num_hipri_links++; else num_lowpri_links++; } } /* now adjust high priority link quota */ low_quota = num_lowpri_links ? 1 : 0; while ( (num_hipri_links * high_pri_link_quota + low_quota) > controller_xmit_quota ) high_pri_link_quota--; /* Work out the xmit quota and buffer quota high and low priorities */ hi_quota = num_hipri_links * high_pri_link_quota; low_quota = (hi_quota < controller_xmit_quota) ? controller_xmit_quota - hi_quota : 1; /* Work out and save the HCI xmit quota for each low priority link */ /* If each low priority link cannot have at least one buffer */ if (num_lowpri_links > low_quota) { l2cb.round_robin_quota = low_quota; qq = qq_remainder = 1; } /* If each low priority link can have at least one buffer */ else if (num_lowpri_links > 0) { l2cb.round_robin_quota = 0; l2cb.round_robin_unacked = 0; qq = low_quota / num_lowpri_links; qq_remainder = low_quota % num_lowpri_links; } /* If no low priority link */ else { l2cb.round_robin_quota = 0; l2cb.round_robin_unacked = 0; qq = qq_remainder = 1; } L2CAP_TRACE_EVENT ("l2c_link_adjust_allocation num_hipri: %u num_lowpri: %u low_quota: %u round_robin_quota: %u qq: %u", num_hipri_links, num_lowpri_links, low_quota, l2cb.round_robin_quota, qq); /* Now, assign the quotas to each link */ for (yy = 0, p_lcb = &l2cb.lcb_pool[0]; yy < MAX_L2CAP_LINKS; yy++, p_lcb++) { if (p_lcb->in_use) { if (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) { p_lcb->link_xmit_quota = high_pri_link_quota; } else { /* Safety check in case we switched to round-robin with something outstanding */ /* if sent_not_acked is added into round_robin_unacked then don't add it again */ /* l2cap keeps updating sent_not_acked for exiting from round robin */ if (( p_lcb->link_xmit_quota > 0 )&&( qq == 0 )) l2cb.round_robin_unacked += p_lcb->sent_not_acked; p_lcb->link_xmit_quota = qq; if (qq_remainder > 0) { p_lcb->link_xmit_quota++; qq_remainder--; } } L2CAP_TRACE_EVENT ("l2c_link_adjust_allocation LCB %d Priority: %d XmitQuota: %d", yy, p_lcb->acl_priority, p_lcb->link_xmit_quota); L2CAP_TRACE_EVENT (" SentNotAcked: %d RRUnacked: %d", p_lcb->sent_not_acked, l2cb.round_robin_unacked); /* There is a special case where we have readjusted the link quotas and */ /* this link may have sent anything but some other link sent packets so */ /* so we may need a timer to kick off this link's transmissions. */ if ( (p_lcb->link_state == LST_CONNECTED) && (!list_is_empty(p_lcb->link_xmit_data_q)) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota) ) { alarm_set_on_queue(p_lcb->l2c_lcb_timer, L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); } } } } /******************************************************************************* ** ** Function l2c_link_adjust_chnl_allocation ** ** Description This function is called to calculate the amount of packets each ** non-F&EC channel may have outstanding. ** ** Currently, this is a simple allocation, dividing the number ** of packets allocated to the link by the number of channels. In ** the future, QOS configuration should be examined. ** ** Returns void ** *******************************************************************************/ void l2c_link_adjust_chnl_allocation (void) { UINT8 xx; L2CAP_TRACE_DEBUG("%s", __func__); /* assign buffer quota to each channel based on its data rate requirement */ for (xx = 0; xx < MAX_L2CAP_CHANNELS; xx++) { tL2C_CCB *p_ccb = l2cb.ccb_pool + xx; if (!p_ccb->in_use) continue; tL2CAP_CHNL_DATA_RATE data_rate = p_ccb->tx_data_rate + p_ccb->rx_data_rate; p_ccb->buff_quota = L2CAP_CBB_DEFAULT_DATA_RATE_BUFF_QUOTA * data_rate; L2CAP_TRACE_EVENT("CID:0x%04x FCR Mode:%u Priority:%u TxDataRate:%u RxDataRate:%u Quota:%u", p_ccb->local_cid, p_ccb->peer_cfg.fcr.mode, p_ccb->ccb_priority, p_ccb->tx_data_rate, p_ccb->rx_data_rate, p_ccb->buff_quota); /* quota may be change so check congestion */ l2cu_check_channel_congestion(p_ccb); } } /******************************************************************************* ** ** Function l2c_link_processs_num_bufs ** ** Description This function is called when a "controller buffer size" ** event is first received from the controller. It updates ** the L2CAP values. ** ** Returns void ** *******************************************************************************/ void l2c_link_processs_num_bufs (UINT16 num_lm_acl_bufs) { l2cb.num_lm_acl_bufs = l2cb.controller_xmit_window = num_lm_acl_bufs; } /******************************************************************************* ** ** Function l2c_link_pkts_rcvd ** ** Description This function is called from the HCI transport when it is time ** tto send a "Host ready for packets" command. This is only when ** host to controller flow control is used. If fills in the arrays ** of numbers of packets and handles. ** ** Returns count of number of entries filled in ** *******************************************************************************/ UINT8 l2c_link_pkts_rcvd (UINT16 *num_pkts, UINT16 *handles) { UINT8 num_found = 0; UNUSED(num_pkts); UNUSED(handles); return (num_found); } /******************************************************************************* ** ** Function l2c_link_role_changed ** ** Description This function is called whan a link's master/slave role change ** event is received. It simply updates the link control block. ** ** Returns void ** *******************************************************************************/ void l2c_link_role_changed (BD_ADDR bd_addr, UINT8 new_role, UINT8 hci_status) { tL2C_LCB *p_lcb; int xx; /* Make sure not called from HCI Command Status (bd_addr and new_role are invalid) */ if (bd_addr) { /* If here came form hci role change event */ p_lcb = l2cu_find_lcb_by_bd_addr (bd_addr, BT_TRANSPORT_BR_EDR); if (p_lcb) { p_lcb->link_role = new_role; /* Reset high priority link if needed */ if (hci_status == HCI_SUCCESS) l2cu_set_acl_priority(bd_addr, p_lcb->acl_priority, TRUE); } } /* Check if any LCB was waiting for switch to be completed */ for (xx = 0, p_lcb = &l2cb.lcb_pool[0]; xx < MAX_L2CAP_LINKS; xx++, p_lcb++) { if ((p_lcb->in_use) && (p_lcb->link_state == LST_CONNECTING_WAIT_SWITCH)) { l2cu_create_conn_after_switch (p_lcb); } } } /******************************************************************************* ** ** Function l2c_pin_code_request ** ** Description This function is called whan a pin-code request is received ** on a connection. If there are no channels active yet on the ** link, it extends the link first connection timer. Make sure ** that inactivity timer is not extended if PIN code happens ** to be after last ccb released. ** ** Returns void ** *******************************************************************************/ void l2c_pin_code_request (BD_ADDR bd_addr) { tL2C_LCB *p_lcb = l2cu_find_lcb_by_bd_addr (bd_addr, BT_TRANSPORT_BR_EDR); if ( (p_lcb) && (!p_lcb->ccb_queue.p_first_ccb) ) { alarm_set_on_queue(p_lcb->l2c_lcb_timer, L2CAP_LINK_CONNECT_EXT_TIMEOUT_MS, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); } } #if L2CAP_WAKE_PARKED_LINK == TRUE /******************************************************************************* ** ** Function l2c_link_check_power_mode ** ** Description This function is called to check power mode. ** ** Returns TRUE if link is going to be active from park ** FALSE if nothing to send or not in park mode ** *******************************************************************************/ BOOLEAN l2c_link_check_power_mode (tL2C_LCB *p_lcb) { tBTM_PM_MODE mode; tL2C_CCB *p_ccb; BOOLEAN need_to_active = FALSE; /* * We only switch park to active only if we have unsent packets */ if (list_is_empty(p_lcb->link_xmit_data_q)) { for (p_ccb = p_lcb->ccb_queue.p_first_ccb; p_ccb; p_ccb = p_ccb->p_next_ccb) { if (!fixed_queue_is_empty(p_ccb->xmit_hold_q)) { need_to_active = TRUE; break; } } } else need_to_active = TRUE; /* if we have packets to send */ if ( need_to_active ) { /* check power mode */ if (BTM_ReadPowerMode(p_lcb->remote_bd_addr, &mode) == BTM_SUCCESS) { if ( mode == BTM_PM_STS_PENDING ) { L2CAP_TRACE_DEBUG ("LCB(0x%x) is in PM pending state", p_lcb->handle); return TRUE; } } } return FALSE; } #endif /* L2CAP_WAKE_PARKED_LINK == TRUE) */ /******************************************************************************* ** ** Function l2c_link_check_send_pkts ** ** Description This function is called to check if it can send packets ** to the Host Controller. It may be passed the address of ** a packet to send. ** ** Returns void ** *******************************************************************************/ void l2c_link_check_send_pkts (tL2C_LCB *p_lcb, tL2C_CCB *p_ccb, BT_HDR *p_buf) { int xx; BOOLEAN single_write = FALSE; /* Save the channel ID for faster counting */ if (p_buf) { if (p_ccb != NULL) { p_buf->event = p_ccb->local_cid; single_write = TRUE; } else p_buf->event = 0; p_buf->layer_specific = 0; list_append(p_lcb->link_xmit_data_q, p_buf); if (p_lcb->link_xmit_quota == 0) { #if BLE_INCLUDED == TRUE if (p_lcb->transport == BT_TRANSPORT_LE) l2cb.ble_check_round_robin = TRUE; else #endif l2cb.check_round_robin = TRUE; } } /* If this is called from uncongested callback context break recursive calling. ** This LCB will be served when receiving number of completed packet event. */ if (l2cb.is_cong_cback_context) return; /* If we are in a scenario where there are not enough buffers for each link to ** have at least 1, then do a round-robin for all the LCBs */ if ( (p_lcb == NULL) || (p_lcb->link_xmit_quota == 0) ) { if (p_lcb == NULL) p_lcb = l2cb.lcb_pool; else if (!single_write) p_lcb++; /* Loop through, starting at the next */ for (xx = 0; xx < MAX_L2CAP_LINKS; xx++, p_lcb++) { /* If controller window is full, nothing to do */ if (((l2cb.controller_xmit_window == 0 || (l2cb.round_robin_unacked >= l2cb.round_robin_quota)) #if (BLE_INCLUDED == TRUE) && (p_lcb->transport == BT_TRANSPORT_BR_EDR) ) || (p_lcb->transport == BT_TRANSPORT_LE && (l2cb.ble_round_robin_unacked >= l2cb.ble_round_robin_quota || l2cb.controller_le_xmit_window == 0 ))) #else )) #endif break; /* Check for wraparound */ if (p_lcb == &l2cb.lcb_pool[MAX_L2CAP_LINKS]) p_lcb = &l2cb.lcb_pool[0]; if ( (!p_lcb->in_use) || (p_lcb->partial_segment_being_sent) || (p_lcb->link_state != LST_CONNECTED) || (p_lcb->link_xmit_quota != 0) || (L2C_LINK_CHECK_POWER_MODE (p_lcb)) ) continue; /* See if we can send anything from the Link Queue */ if (!list_is_empty(p_lcb->link_xmit_data_q)) { p_buf = (BT_HDR *)list_front(p_lcb->link_xmit_data_q); list_remove(p_lcb->link_xmit_data_q, p_buf); l2c_link_send_to_lower (p_lcb, p_buf); } else if (single_write) { /* If only doing one write, break out */ break; } /* If nothing on the link queue, check the channel queue */ else if ((p_buf = l2cu_get_next_buffer_to_send (p_lcb)) != NULL) { l2c_link_send_to_lower (p_lcb, p_buf); } } /* If we finished without using up our quota, no need for a safety check */ if ( (l2cb.controller_xmit_window > 0) && (l2cb.round_robin_unacked < l2cb.round_robin_quota) #if (BLE_INCLUDED == TRUE) && (p_lcb->transport == BT_TRANSPORT_BR_EDR) #endif ) l2cb.check_round_robin = FALSE; #if (BLE_INCLUDED == TRUE) if ( (l2cb.controller_le_xmit_window > 0) && (l2cb.ble_round_robin_unacked < l2cb.ble_round_robin_quota) && (p_lcb->transport == BT_TRANSPORT_LE)) l2cb.ble_check_round_robin = FALSE; #endif } else /* if this is not round-robin service */ { /* If a partial segment is being sent, can't send anything else */ if ( (p_lcb->partial_segment_being_sent) || (p_lcb->link_state != LST_CONNECTED) || (L2C_LINK_CHECK_POWER_MODE (p_lcb)) ) return; /* See if we can send anything from the link queue */ #if (BLE_INCLUDED == TRUE) while ( ((l2cb.controller_xmit_window != 0 && (p_lcb->transport == BT_TRANSPORT_BR_EDR)) || (l2cb.controller_le_xmit_window != 0 && (p_lcb->transport == BT_TRANSPORT_LE))) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) #else while ( (l2cb.controller_xmit_window != 0) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) #endif { if (list_is_empty(p_lcb->link_xmit_data_q)) break; p_buf = (BT_HDR *)list_front(p_lcb->link_xmit_data_q); list_remove(p_lcb->link_xmit_data_q, p_buf); if (!l2c_link_send_to_lower (p_lcb, p_buf)) break; } if (!single_write) { /* See if we can send anything for any channel */ #if (BLE_INCLUDED == TRUE) while ( ((l2cb.controller_xmit_window != 0 && (p_lcb->transport == BT_TRANSPORT_BR_EDR)) || (l2cb.controller_le_xmit_window != 0 && (p_lcb->transport == BT_TRANSPORT_LE))) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) #else while ((l2cb.controller_xmit_window != 0) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota)) #endif { if ((p_buf = l2cu_get_next_buffer_to_send (p_lcb)) == NULL) break; if (!l2c_link_send_to_lower (p_lcb, p_buf)) break; } } /* There is a special case where we have readjusted the link quotas and */ /* this link may have sent anything but some other link sent packets so */ /* so we may need a timer to kick off this link's transmissions. */ if ( (!list_is_empty(p_lcb->link_xmit_data_q)) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota) ) { alarm_set_on_queue(p_lcb->l2c_lcb_timer, L2CAP_LINK_FLOW_CONTROL_TIMEOUT_MS, l2c_lcb_timer_timeout, p_lcb, btu_general_alarm_queue); } } } /******************************************************************************* ** ** Function l2c_link_send_to_lower ** ** Description This function queues the buffer for HCI transmission ** ** Returns TRUE for success, FALSE for fail ** *******************************************************************************/ static BOOLEAN l2c_link_send_to_lower (tL2C_LCB *p_lcb, BT_HDR *p_buf) { UINT16 num_segs; UINT16 xmit_window, acl_data_size; const controller_t *controller = controller_get_interface(); if ((p_buf->len <= controller->get_acl_packet_size_classic() #if (BLE_INCLUDED == TRUE) && (p_lcb->transport == BT_TRANSPORT_BR_EDR)) || ((p_lcb->transport == BT_TRANSPORT_LE) && (p_buf->len <= controller->get_acl_packet_size_ble())) #else ) #endif ) { if (p_lcb->link_xmit_quota == 0) { #if (BLE_INCLUDED == TRUE) if (p_lcb->transport == BT_TRANSPORT_LE) l2cb.ble_round_robin_unacked++; else #endif l2cb.round_robin_unacked++; } p_lcb->sent_not_acked++; p_buf->layer_specific = 0; #if (BLE_INCLUDED == TRUE) if (p_lcb->transport == BT_TRANSPORT_LE) { l2cb.controller_le_xmit_window--; bte_main_hci_send(p_buf, (UINT16)(BT_EVT_TO_LM_HCI_ACL|LOCAL_BLE_CONTROLLER_ID)); } else #endif { l2cb.controller_xmit_window--; bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL); } } else { #if BLE_INCLUDED == TRUE if (p_lcb->transport == BT_TRANSPORT_LE) { acl_data_size = controller->get_acl_data_size_ble(); xmit_window = l2cb.controller_le_xmit_window; } else #endif { acl_data_size = controller->get_acl_data_size_classic(); xmit_window = l2cb.controller_xmit_window; } num_segs = (p_buf->len - HCI_DATA_PREAMBLE_SIZE + acl_data_size - 1) / acl_data_size; /* If doing round-robin, then only 1 segment each time */ if (p_lcb->link_xmit_quota == 0) { num_segs = 1; p_lcb->partial_segment_being_sent = TRUE; } else { /* Multi-segment packet. Make sure it can fit */ if (num_segs > xmit_window) { num_segs = xmit_window; p_lcb->partial_segment_being_sent = TRUE; } if (num_segs > (p_lcb->link_xmit_quota - p_lcb->sent_not_acked)) { num_segs = (p_lcb->link_xmit_quota - p_lcb->sent_not_acked); p_lcb->partial_segment_being_sent = TRUE; } } p_buf->layer_specific = num_segs; #if BLE_INCLUDED == TRUE if (p_lcb->transport == BT_TRANSPORT_LE) { l2cb.controller_le_xmit_window -= num_segs; if (p_lcb->link_xmit_quota == 0) l2cb.ble_round_robin_unacked += num_segs; } else #endif { l2cb.controller_xmit_window -= num_segs; if (p_lcb->link_xmit_quota == 0) l2cb.round_robin_unacked += num_segs; } p_lcb->sent_not_acked += num_segs; #if BLE_INCLUDED == TRUE if (p_lcb->transport == BT_TRANSPORT_LE) { bte_main_hci_send(p_buf, (UINT16)(BT_EVT_TO_LM_HCI_ACL|LOCAL_BLE_CONTROLLER_ID)); } else #endif { bte_main_hci_send(p_buf, BT_EVT_TO_LM_HCI_ACL); } } #if (L2CAP_HCI_FLOW_CONTROL_DEBUG == TRUE) #if (BLE_INCLUDED == TRUE) if (p_lcb->transport == BT_TRANSPORT_LE) { L2CAP_TRACE_DEBUG ("TotalWin=%d,Hndl=0x%x,Quota=%d,Unack=%d,RRQuota=%d,RRUnack=%d", l2cb.controller_le_xmit_window, p_lcb->handle, p_lcb->link_xmit_quota, p_lcb->sent_not_acked, l2cb.ble_round_robin_quota, l2cb.ble_round_robin_unacked); } else #endif { L2CAP_TRACE_DEBUG ("TotalWin=%d,Hndl=0x%x,Quota=%d,Unack=%d,RRQuota=%d,RRUnack=%d", l2cb.controller_xmit_window, p_lcb->handle, p_lcb->link_xmit_quota, p_lcb->sent_not_acked, l2cb.round_robin_quota, l2cb.round_robin_unacked); } #endif return TRUE; } /******************************************************************************* ** ** Function l2c_link_process_num_completed_pkts ** ** Description This function is called when a "number-of-completed-packets" ** event is received from the controller. It updates all the ** LCB transmit counts. ** ** Returns void ** *******************************************************************************/ void l2c_link_process_num_completed_pkts (UINT8 *p) { UINT8 num_handles, xx; UINT16 handle; UINT16 num_sent; tL2C_LCB *p_lcb; STREAM_TO_UINT8 (num_handles, p); for (xx = 0; xx < num_handles; xx++) { STREAM_TO_UINT16 (handle, p); STREAM_TO_UINT16 (num_sent, p); p_lcb = l2cu_find_lcb_by_handle (handle); /* Callback for number of completed packet event */ /* Originally designed for [3DSG] */ if((p_lcb != NULL) && (p_lcb->p_nocp_cb)) { L2CAP_TRACE_DEBUG ("L2CAP - calling NoCP callback"); (*p_lcb->p_nocp_cb)(p_lcb->remote_bd_addr); } if (p_lcb) { #if (BLE_INCLUDED == TRUE) if (p_lcb && (p_lcb->transport == BT_TRANSPORT_LE)) l2cb.controller_le_xmit_window += num_sent; else #endif { /* Maintain the total window to the controller */ l2cb.controller_xmit_window += num_sent; } /* If doing round-robin, adjust communal counts */ if (p_lcb->link_xmit_quota == 0) { #if BLE_INCLUDED == TRUE if (p_lcb->transport == BT_TRANSPORT_LE) { /* Don't go negative */ if (l2cb.ble_round_robin_unacked > num_sent) l2cb.ble_round_robin_unacked -= num_sent; else l2cb.ble_round_robin_unacked = 0; } else #endif { /* Don't go negative */ if (l2cb.round_robin_unacked > num_sent) l2cb.round_robin_unacked -= num_sent; else l2cb.round_robin_unacked = 0; } } /* Don't go negative */ if (p_lcb->sent_not_acked > num_sent) p_lcb->sent_not_acked -= num_sent; else p_lcb->sent_not_acked = 0; l2c_link_check_send_pkts (p_lcb, NULL, NULL); /* If we were doing round-robin for low priority links, check 'em */ if ( (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) && (l2cb.check_round_robin) && (l2cb.round_robin_unacked < l2cb.round_robin_quota) ) { l2c_link_check_send_pkts (NULL, NULL, NULL); } #if BLE_INCLUDED == TRUE if ((p_lcb->transport == BT_TRANSPORT_LE) && (p_lcb->acl_priority == L2CAP_PRIORITY_HIGH) && ((l2cb.ble_check_round_robin) && (l2cb.ble_round_robin_unacked < l2cb.ble_round_robin_quota))) { l2c_link_check_send_pkts (NULL, NULL, NULL); } #endif } #if (L2CAP_HCI_FLOW_CONTROL_DEBUG == TRUE) if (p_lcb) { #if (BLE_INCLUDED == TRUE) if (p_lcb->transport == BT_TRANSPORT_LE) { L2CAP_TRACE_DEBUG ("TotalWin=%d,LinkUnack(0x%x)=%d,RRCheck=%d,RRUnack=%d", l2cb.controller_le_xmit_window, p_lcb->handle, p_lcb->sent_not_acked, l2cb.ble_check_round_robin, l2cb.ble_round_robin_unacked); } else #endif { L2CAP_TRACE_DEBUG ("TotalWin=%d,LinkUnack(0x%x)=%d,RRCheck=%d,RRUnack=%d", l2cb.controller_xmit_window, p_lcb->handle, p_lcb->sent_not_acked, l2cb.check_round_robin, l2cb.round_robin_unacked); } } else { #if (BLE_INCLUDED == TRUE) L2CAP_TRACE_DEBUG ("TotalWin=%d LE_Win: %d, Handle=0x%x, RRCheck=%d, RRUnack=%d", l2cb.controller_xmit_window, l2cb.controller_le_xmit_window, handle, l2cb.ble_check_round_robin, l2cb.ble_round_robin_unacked); #else L2CAP_TRACE_DEBUG ("TotalWin=%d Handle=0x%x RRCheck=%d RRUnack=%d", l2cb.controller_xmit_window, handle, l2cb.check_round_robin, l2cb.round_robin_unacked); #endif } #endif } #if (defined(HCILP_INCLUDED) && HCILP_INCLUDED == TRUE) /* only full stack can enable sleep mode */ btu_check_bt_sleep (); #endif } /******************************************************************************* ** ** Function l2c_link_segments_xmitted ** ** Description This function is called from the HCI Interface when an ACL ** data packet segment is transmitted. ** ** Returns void ** *******************************************************************************/ void l2c_link_segments_xmitted (BT_HDR *p_msg) { UINT8 *p = (UINT8 *)(p_msg + 1) + p_msg->offset; UINT16 handle; tL2C_LCB *p_lcb; /* Extract the handle */ STREAM_TO_UINT16 (handle, p); handle = HCID_GET_HANDLE (handle); /* Find the LCB based on the handle */ if ((p_lcb = l2cu_find_lcb_by_handle (handle)) == NULL) { L2CAP_TRACE_WARNING ("L2CAP - rcvd segment complete, unknown handle: %d", handle); osi_free(p_msg); return; } if (p_lcb->link_state == LST_CONNECTED) { /* Enqueue the buffer to the head of the transmit queue, and see */ /* if we can transmit anything more. */ list_prepend(p_lcb->link_xmit_data_q, p_msg); p_lcb->partial_segment_being_sent = FALSE; l2c_link_check_send_pkts (p_lcb, NULL, NULL); } else osi_free(p_msg); }