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implement L2CAP packet recombination in hci.c using a max size L2CAP buffer per connection

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matthias.ringwald 2010-02-13 15:15:19 +00:00
parent c1012e4687
commit 7856c8184a
1 changed files with 84 additions and 10 deletions
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94
src/hci.c
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@ -88,13 +88,6 @@ static void hci_connection_timestamp(hci_connection_t *connection){
gettimeofday(&connection->timestamp, NULL);
}
static void hci_connection_update_timestamp_for_acl(uint8_t *packet) {
// update timestamp
hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
hci_connection_t *connection = connection_for_handle( con_handle);
if (connection) hci_connection_timestamp(connection);
}
/**
* create connection for given address
*
@ -110,6 +103,7 @@ static hci_connection_t * create_connection_for_addr(bd_addr_t addr){
conn->timeout.process = hci_connection_timeout_handler;
hci_connection_timestamp(conn);
conn->acl_recombination_length = 0;
conn->acl_recombination_pos = 0;
linked_list_add(&hci_stack.connections, (linked_item_t *) conn);
return conn;
}
@ -163,13 +157,93 @@ static bt_control_t null_control = {
int hci_send_acl_packet(uint8_t *packet, int size){
hci_connection_update_timestamp_for_acl(packet);
// update idle timestamp
hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
hci_connection_t *connection = connection_for_handle( con_handle);
if (connection) hci_connection_timestamp(connection);
// send packet
return hci_stack.hci_transport->send_acl_packet(packet, size);
}
static void acl_handler(uint8_t *packet, int size){
hci_connection_update_timestamp_for_acl(packet);
hci_stack.acl_packet_handler(packet, size);
// get info
hci_con_handle_t con_handle = READ_ACL_CONNECTION_HANDLE(packet);
hci_connection_t *conn = connection_for_handle(con_handle);
uint8_t acl_flags = READ_ACL_FLAGS(packet);
uint16_t acl_length = READ_ACL_LENGTH(packet);
// ignore non-registered handle
if (!conn){
fprintf(stderr, "hci.c: acl_handler called with non-registered handle %u!\n" , con_handle);
return;
}
// update idle timestamp
hci_connection_timestamp(conn);
// handle different packet types
switch (acl_flags & 0x03) {
case 0x01: // continuation fragment
// sanity check
if (conn->acl_recombination_pos == 0) {
fprintf(stderr, "ACL Cont Fragment but no first fragment for handle 0x%02x\n", con_handle);
return;
}
// append fragment payload (header already stored)
memcpy(&conn->acl_recombination_buffer[conn->acl_recombination_pos], &packet[4], acl_length );
conn->acl_recombination_pos += acl_length;
// fprintf(stderr, "ACL Cont Fragment: acl_len %u, combined_len %u, l2cap_len %u\n",
// acl_length, connection->acl_recombination_pos, connection->acl_recombination_length);
// forward complete L2CAP packet if complete.
if (conn->acl_recombination_pos >= conn->acl_recombination_length + 4 + 4){ // pos already incl. ACL header
hci_stack.acl_packet_handler(conn->acl_recombination_buffer, conn->acl_recombination_pos);
// reset recombination buffer
conn->acl_recombination_length = 0;
conn->acl_recombination_pos = 0;
}
break;
case 0x02: { // first fragment
// sanity check
if (conn->acl_recombination_pos) {
fprintf(stderr, "ACL First Fragment but data in buffer for handle 0x%02x\n", con_handle);
return;
}
// peek into L2CAP packet!
uint16_t l2cap_length = READ_L2CAP_LENGTH( packet );
// compare fragment size to L2CAP packet size
if (acl_length >= l2cap_length + 4){
// forward fragment as L2CAP packet
hci_stack.acl_packet_handler(packet, acl_length + 4);
} else {
// store first fragment and tweak acl length for complete package
memcpy(conn->acl_recombination_buffer, packet, acl_length + 4);
conn->acl_recombination_pos = acl_length + 4;
conn->acl_recombination_length = l2cap_length;
bt_store_16(conn->acl_recombination_buffer, 2, acl_length +4);
// fprintf(stderr, "ACL First Fragment: acl_len %u, l2cap_len %u\n", acl_length, l2cap_length);
}
break;
}
default:
fprintf(stderr, "hci.c: acl_handler called with invalid packet boundary flags %u\n", acl_flags & 0x03);
return;
}
// execute main loop
hci_run();