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rework the disconnect / connect workaround #28

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Merged
merged 1 commit into from
Aug 12, 2021
Merged

rework the disconnect / connect workaround #28

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79 changes: 68 additions & 11 deletions src/BluetoothHciSocket.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -291,6 +291,10 @@ void BluetoothHciSocket::stop() {
}

void BluetoothHciSocket::write_(char* data, int length) {
if (this->_mode == HCI_CHANNEL_RAW && this->kernelConnectWorkArounds(data, length)) {
return;
}

if (write(this->_socket, data, length) < 0) {
this->emitErrnoError("write");
}
Expand Down Expand Up @@ -350,11 +354,10 @@ int BluetoothHciSocket::kernelDisconnectWorkArounds(int length, char* data) {
// HCI Event - LE Meta Event - LE Connection Complete => manually create L2CAP socket to force kernel to book keep
// HCI Event - Disconn Complete =======================> close socket from above

if (length == 22 && data[0] == 0x04 && data[1] == 0x3e && data[2] == 0x13 && data[3] == 0x01 && data[4] == 0x00) {
if (length == 22 && data[0] == 0x04 && data[1] == 0x3e && data[2] == 0x13 && data[3] == 0x01 && data[4] == 0x00 && data[7] == 0x01) {
int l2socket;
struct sockaddr_l2 l2a = {};
unsigned short l2cid;
unsigned short handle = *((unsigned short*)(&data[5]));

#if __BYTE_ORDER == __LITTLE_ENDIAN
l2cid = ATT_CID;
Expand Down Expand Up @@ -385,21 +388,75 @@ int BluetoothHciSocket::kernelDisconnectWorkArounds(int length, char* data) {
l2a.l2_cid = l2cid;
l2a.l2_bdaddr_type = data[8] + 1; // BDADDR_LE_PUBLIC (0x01), BDADDR_LE_RANDOM (0x02)

if (connect(l2socket, (struct sockaddr *)&l2a, sizeof(l2a)) < -1) {
while (connect(l2socket, (struct sockaddr *)&l2a, sizeof(l2a) == -1) ) {
if(errno == EINTR) {
continue;
}
close(l2socket);
return -3;
}

this->_l2sockets[handle] = l2socket;
} else if (length == 7 && data[0] == 0x04 && data[1] == 0x05 && data[2] == 0x04 && data[3] == 0x00) {
unsigned short handle = *((unsigned short*)(&data[4]));
return 0;
}
}

if (this->_l2sockets.count(handle) > 0) {
close(this->_l2sockets[handle]);
this->_l2sockets.erase(handle);
}

bool BluetoothHciSocket::kernelConnectWorkArounds(char* data, int length)
{
if (length == 29 && data[0] == 0x01 && data[1] == 0x0d && data[2] == 0x20 && data[3] == 0x19) {
int l2socket;
struct sockaddr_l2 l2a;
unsigned short l2cid;
unsigned short connMinInterval;
unsigned short connMaxInterval;
unsigned short connLatency;
unsigned short supervisionTimeout;
char command[128];

#if __BYTE_ORDER == __LITTLE_ENDIAN
l2cid = ATT_CID;
#elif __BYTE_ORDER == __BIG_ENDIAN
l2cid = bswap_16(ATT_CID);
#else
#error "Unknown byte order"
#endif

l2socket = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);

memset(&l2a, 0, sizeof(l2a));
l2a.l2_family = AF_BLUETOOTH;
l2a.l2_cid = l2cid;
memcpy(&l2a.l2_bdaddr, this->_address, sizeof(l2a.l2_bdaddr));
l2a.l2_bdaddr_type = this->_addressType;
bind(l2socket, (struct sockaddr*)&l2a, sizeof(l2a));

memset(&l2a, 0, sizeof(l2a));
l2a.l2_family = AF_BLUETOOTH;
memcpy(&l2a.l2_bdaddr, &data[10], sizeof(l2a.l2_bdaddr));
l2a.l2_cid = l2cid;
l2a.l2_bdaddr_type = data[9] + 1; // BDADDR_LE_PUBLIC (0x01), BDADDR_LE_RANDOM (0x02)

// extract the connection parameter
connMinInterval = (data[18] << 8) | data[17];
connMaxInterval = (data[20] << 8) | data[19];
connLatency = (data[22] << 8) | data[21];
supervisionTimeout = (data[24] << 8) | data[23];

// override the HCI devices connection parameters using debugfs
sprintf(command, "echo %u > /sys/kernel/debug/bluetooth/hci%d/conn_min_interval", connMinInterval, this->_devId);
system(command);
sprintf(command, "echo %u > /sys/kernel/debug/bluetooth/hci%d/conn_max_interval", connMaxInterval, this->_devId);
system(command);
sprintf(command, "echo %u > /sys/kernel/debug/bluetooth/hci%d/conn_latency", connLatency, this->_devId);
system(command);
sprintf(command, "echo %u > /sys/kernel/debug/bluetooth/hci%d/supervision_timeout", supervisionTimeout, this->_devId);
system(command);

connect(l2socket, (struct sockaddr *)&l2a, sizeof(l2a));
return true;
}
return 0;

return false;
}

NAN_METHOD(BluetoothHciSocket::New) {
Expand Down
4 changes: 1 addition & 3 deletions src/BluetoothHciSocket.h
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Original file line number Diff line number Diff line change
@@ -1,8 +1,6 @@
#ifndef ___BLUETOOTH_HCI_SOCKET_H___
#define ___BLUETOOTH_HCI_SOCKET_H___

#include <map>

#include <node.h>

#include <nan.h>
Expand Down Expand Up @@ -42,6 +40,7 @@ class BluetoothHciSocket : public node::ObjectWrap {
void emitErrnoError(const char *syscall);
int devIdFor(const int* devId, bool isUp);
int kernelDisconnectWorkArounds(int length, char* data);
bool kernelConnectWorkArounds(char* data, int length);

static void PollCloseCallback(uv_poll_t* handle);
static void PollCallback(uv_poll_t* handle, int status, int events);
Expand All @@ -53,7 +52,6 @@ class BluetoothHciSocket : public node::ObjectWrap {
int _socket;
int _devId;
uv_poll_t _pollHandle;
std::map<unsigned short,int> _l2sockets;
uint8_t _address[6];
uint8_t _addressType;

Expand Down