nfcd is a daemon running under the mobile user. It handles the communications between PassKit and the underlying hardware and libraries.
Core objects
- NFDaemon
- NFFieldDetectController
- NFCoreTelephonyConnection
- NFPowerManager
- NFAbstractController
- NFCardEmulationController
- NFSecureElementController
Launchd plist
{
EnablePressuredExit = 1;
EnableTransactions = 1;
ExitTimeOut = 45;
Label = "com.apple.nfcd";
MachServices = {
"com.apple.nfcd" = 1;
};
ProcessType = Interactive;
Program = "/usr/libexec/nfcd";
UserName = mobile;
}
Where the XPC service is registered under the "com.apple.nfcd" name
Supported XPC Commands
ID | Command |
---|---|
1 | q_registerConnection:info: |
2 | q_unregisterConnection: |
3-64 | send command to SE controller |
65 | q_updateSecureElementPowerState |
66 | _seIsInRestrictedMode |
67 | restrictedModeChanged |
68-239 | callSEContoller |
240 | setDeviceString |
241 | q_getControllerInfo |
242 | q_getSecureElementInfo |
243 | q_getBoosterInfo |
244 | q_readBoosterRegister |
245 | q_sendBoosterCommand |
246 | q_triggerAssertion |
>247 | throw error |
Sending XPC Commands
Four XPC keys are sent for the XPC command:
- NFMsgObject - dictionary containing values to sent to receiving objects
- NFMsgType - uint64, sending is a 0, receiving a 1
- NFMsgCode - uint64, "command" as described above
- NFMsgId - uint64, undetermined
Example of XPC command to the nfcd:
#include <xpc/xpc.h>
int main(int argc, char **argv, char **envp) {
// Create connection to mach service
xpc_connection_t connection = xpc_connection_create_mach_service("com.apple.nfcd", NULL, 0);
xpc_connection_set_event_handler(connection, ^(xpc_object_t object) {
char *description = xpc_copy_description(object);
printf("Sending object: %s\n", description);
free(description);
});
xpc_connection_resume(connection);
while (true) {
// Send message to mach service, and wait for a response
xpc_object_t msgobject = xpc_dictionary_create(NULL,NULL,0);
xpc_object_t object = xpc_dictionary_create(NULL, NULL, 0);
xpc_dictionary_set_int64(msgobject, "Controller", 6);
xpc_dictionary_set_value(object, "NFMsgObject", msgobject);
xpc_dictionary_set_uint64(object, "NFMsgType", 0x00);
xpc_dictionary_set_uint64(object, "NFMsgCode", 0x01);
xpc_dictionary_set_uint64(object, "NFMsgId", 17);
char *description = xpc_copy_description(object);
printf("Sending object: %s\n", description);
free(description);
xpc_object_t reply = xpc_connection_send_message_with_reply_sync(connection, object);
description = xpc_copy_description(object);
printf("Received reply object: %s\n\n", description);
free(description);
sleep(1);
}
return 0;
}
NFDaemon methods
Signature | -(void)XPCConnection:(id)connection didReceiveCommand:(id)command; |
---|---|
Available in | 8.0 - 9.0.1 |
Signature | -(int)q_registerConnection:(id)connection info:(id)info; |
---|---|
Available in | 8.0 - 9.0.1 |
This function checks for an existing controller
- [NFCardEmulationController embeddedCardEmulationController]
- [NFCardEmulationController UICCCardEmulationController]
- [NFSecureElementController seController]
- [NFFieldDetectController fieldDetectController]
When it finds the appropriate controller it calls the unregister function for it.
Signature | -(unsigned int)q_unregisterConnection:(id)connection; |
---|---|
Available in | 8.0 - 9.0.1 |