monitor.m   [plain text]

//
//  monitor.m
//  IOHIDFamily
//
//  Created by dekom on 8/2/17.
//

#include <IOKit/hid/IOHIDEventSystemClient.h>
#include <getopt.h>
#include "utility.h"
#import "HIDEvent.h"
#import <objc/runtime.h>

int monitor(int argc, const char * argv[]);

static const char MAIN_OPTIONS_SHORT[] = "p:cm:i:s:t:h";
static const struct option MAIN_OPTIONS[] =
{
    { "predicate",  required_argument,  NULL,   'p' },
    { "children",   no_argument,        NULL,   'c' },
    { "matching",   required_argument,  NULL,   'm' },
    { "info",       required_argument,  NULL,   'i' },
    { "show",       required_argument,  NULL,   's' },
    { "type",       required_argument,  NULL,   't' },
    { "help",       0,                  NULL,   'h' },
    { NULL,         0,                  NULL,    0  }
};

const char monitorUsage[] =
"\nMonitor HID Event System events\n"
"\nUsage:\n\n"
"  hidutil monitor [ --info <eventType | eventName> ][ --predicate <predicate> ][ --show <varibles> ][ --type <event type> ][ --matching <matching> ][ --children ]\n"
"\nFlags:\n\n"
"  -i  --info..................print predicate info for an event type\n"
"  -p  --predicate.............filter events based on predicate\n"
"  -s  --show..................show only specified variables\n"
"  -t  --type..................filter by event type, takes integer or string\n"
"  -c  --children..............show child events\n"
MATCHING_HELP
"\nExamples:\n\n"
"  hidutil monitor --info keyboard\n"
"  hidutil monitor --type keyboard\n"
"  hidutil monitor --predicate 'typestr contains \"digit\"' --children\n"
"  hidutil monitor --predicate 'usagepage == 7 and latency > 100'\n"
"  hidutil monitor --show 'timestamp sender typestr usagepage usage'\n"
"  hidutil monitor --matching '{\"ProductID\":0x54c,\"VendorID\":746}'\n";

static NSCompoundPredicate  *_predicate = NULL;
static bool                 _children   = false;
static NSArray              *_variables = NULL;

static void printClassInfo(Class cls) {
    objc_property_t *properties = NULL;
    unsigned int outCount, i;
    
    properties = class_copyPropertyList(cls, &outCount);
    
    for(i = 0; i < outCount; i++) {
        objc_property_t property = properties[i];
        printf("    %s\n", property_getName(property));
    }
    
    free(properties);
}

static void printEventInfo(char *arg) {
    NSString *eventString       = [NSString stringWithUTF8String:arg];
    NSNumberFormatter *nf       = [[NSNumberFormatter alloc] init];
    BOOL isNum                  = [nf numberFromString:eventString] != nil;
    IOHIDEventRef dummyEvent    = NULL;
    HIDEvent *event             = [[HIDEvent alloc] init];
    IOHIDEventType eventType    = kIOHIDEventTypeCount;
    
    // get event type from string
    if (isNum) {
        eventType = [eventString intValue];
    } else {
        for (uint32_t i = 0; i < kIOHIDEventTypeCount; i++) {
            NSString *eventTypeString = [NSString stringWithUTF8String:IOHIDEventGetTypeString(i)];
            
            if ([[eventTypeString lowercaseString] containsString:eventString]) {
                eventType = i;
                break;
            }
        }
    }
    
    dummyEvent = IOHIDEventCreate(kCFAllocatorDefault, eventType, 0, 0);
    
    printf("base event predicates:\n");
    printClassInfo([event class]);
    
    if (eventType < kIOHIDEventTypeCount) {
        event = createHIDEvent(dummyEvent);
        printf("\n%s event predicates:\n", IOHIDEventGetTypeString(eventType));
        printClassInfo([event class]);
    }
    
    CFRelease(dummyEvent);
}

static void printEventVariables(HIDEvent *event) {
    NSString *eventString = [[NSString alloc] init];
    
    for (NSString *variable in _variables) {
        @try {
            if (variable == _variables.lastObject) {
                eventString = [eventString stringByAppendingFormat:@"%@:%@", variable, [event valueForKey:variable]];
            } else {
                eventString = [eventString stringByAppendingFormat:@"%@:%@ ", variable, [event valueForKey:variable]];
            }
        } @ catch(...) {
        }
    }
    
    if (eventString == nil) {
        printf("%s\n", [[event description] UTF8String]);
    } else {
        printf("%s\n", [eventString UTF8String]);
    }
}

static void eventCallback(void *target __unused, void *refcon __unused, void *sender __unused, IOHIDEventRef event) {
    bool        predicated  = false;
    HIDEvent    *hidEvent   = createHIDEvent(event);
    
    if (_predicate) {
        @try {
            if (![_predicate evaluateWithObject:hidEvent]) {
                predicated = true;
            }
        } @ catch(...) {
            predicated = true;
        }
    }
    
    if (!predicated) {
        if (_variables) {
            printEventVariables(hidEvent);
        } else {
           printf("%s\n", [[hidEvent description] UTF8String]);
        }
        
        if (_children) {
            CFArrayRef children = IOHIDEventGetChildren(event);
            for (CFIndex index = 0, count = children ? CFArrayGetCount(children) : 0; index < count; index++) {
                IOHIDEventRef child = (IOHIDEventRef)CFArrayGetValueAtIndex(children, index);
                HIDEvent *childHIDEvent = createHIDEvent(child);
                
                if (_variables) {
                    printf("    ");
                    printEventVariables(childHIDEvent);
                } else {
                   printf("    %s\n", [[childHIDEvent description] UTF8String]);
                }
            }
        }
    }
}

static NSPredicate *predicateForEventType(NSString *eventType)
{
    if ([eventType rangeOfCharacterFromSet:[NSCharacterSet decimalDigitCharacterSet]].location == NSNotFound) {
        // event type string
        return [NSPredicate predicateWithFormat:@"typestr contains %@", eventType ];
    } else {
        // event type number
        return [NSPredicate predicateWithFormat:@"typeval == %d",  [eventType intValue]];
    }
}

int monitor(int argc __unused, const char * argv[] __unused) {
    int                         arg;
    int                         status              = STATUS_SUCCESS;
    IOHIDEventSystemClientRef   client              = NULL;
    bool                        matching            = false;
    
    client = IOHIDEventSystemClientCreateWithType(kCFAllocatorDefault, kIOHIDEventSystemClientTypeMonitor, NULL);
    if (!client) {
        goto exit;
    }
    
    while ((arg = getopt_long(argc, (char **) argv, MAIN_OPTIONS_SHORT, MAIN_OPTIONS, NULL)) != -1) {
        switch (arg) {
                // --help
            case 'h':
                printf("%s", monitorUsage);
                goto exit;
                // --predicate
            case 'p': {
                NSPredicate *predicate = [NSPredicate predicateWithFormat:@(optarg)];
                if (_predicate) {
                    _predicate = [NSCompoundPredicate andPredicateWithSubpredicates:[NSArray arrayWithObjects:_predicate, predicate, nil]];
                } else {
                    _predicate = (NSCompoundPredicate *)predicate;
                }
                
                if (!_predicate) {
                    printf("Bad predicate: %s\n", optarg);
                    status = STATUS_ERROR;
                    goto exit;
                }
                break;
            }
                // --children
            case 'c':
                _children = true;
                break;
                // --matching
            case 'm':
                matching = setClientMatching(client, optarg);
                if (!matching) {
                    printf ("bad matching string: %s\n", optarg);
                }
                break;
                // --info
            case 'i':
                printEventInfo(optarg);
                goto exit;
                break;
                // --show
            case 's':
                _variables = [[NSString stringWithUTF8String:optarg] componentsSeparatedByString:@" "];
                break;
                // --type
            case 't': {
                NSPredicate *predicate = predicateForEventType([NSString stringWithUTF8String:optarg]);
                
                if (_predicate) {
                    _predicate = [NSCompoundPredicate andPredicateWithSubpredicates:[NSArray arrayWithObjects:_predicate, predicate, nil]];
                } else {
                    _predicate = (NSCompoundPredicate *)predicate;
                }
                break;
            }
            default:
                printf("%s", monitorUsage);
                goto exit;
                break;
        }
    }
    
    IOHIDEventSystemClientRegisterEventCallback(client, eventCallback, NULL, NULL);
    IOHIDEventSystemClientScheduleWithRunLoop(client, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
    
    CFRunLoopRun();
    
    IOHIDEventSystemClientUnscheduleWithRunLoop(client, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
    IOHIDEventSystemClientUnregisterEventCallback(client, eventCallback, NULL, NULL);
    status = STATUS_SUCCESS;
    
exit:
    if (client) {
        CFRelease(client);
    }
    
    return status;
}