网络偏好代理设置

- (void)openPac:(NSString *)pacUrl {
    static AuthorizationRef authRef;
    static AuthorizationFlags authFlags;
    authFlags = kAuthorizationFlagDefaults
    | kAuthorizationFlagExtendRights
    | kAuthorizationFlagInteractionAllowed
    | kAuthorizationFlagPreAuthorize;
    OSStatus authErr = AuthorizationCreate(nil, kAuthorizationEmptyEnvironment, authFlags, &authRef);
    if (authErr != noErr) {
        authRef = nil;
        NSLog(@"Error when create authorization");
    } else {
        if (authRef == NULL) {
            NSLog(@"No authorization has been granted to modify network configuration");
        }
    }

    SCPreferencesRef prefRef = SCPreferencesCreateWithAuthorization(nil, CFSTR("cloudscreen"), nil, authRef);
    NSDictionary *sets = (__bridge NSDictionary *)SCPreferencesGetValue(prefRef, kSCPrefNetworkServices);

    // proxies 设置
    NSMutableDictionary *proxies = [[NSMutableDictionary alloc] init];
    [proxies setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCFNetworkProxiesHTTPEnable];
    [proxies setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCFNetworkProxiesHTTPSEnable];
    [proxies setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCFNetworkProxiesProxyAutoConfigEnable];
    [proxies setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCFNetworkProxiesSOCKSEnable];
    [proxies setObject:@[] forKey:(NSString *)kCFNetworkProxiesExceptionsList];

    for (NSString *key in [sets allKeys]){
        NSMutableDictionary *dict = [sets objectForKey:key];
        NSString *hardware = [dict valueForKeyPath:@"Interface.Hardware"];
        BOOL modify = NO;
        if ([hardware isEqualToString:@"AirPort"]
            || [hardware isEqualToString:@"Wi-Fi"]
            || [hardware isEqualToString:@"Ethernet"]) {
            modify = YES;
        }

        [proxies setObject:pacUrl forKey:(NSString *)kCFNetworkProxiesProxyAutoConfigURLString];
        [proxies setObject:[NSNumber numberWithInt:1] forKey:(NSString *)kCFNetworkProxiesProxyAutoConfigEnable];
        NSString* prefPath = [NSString stringWithFormat:@"/%@/%@/%@", kSCPrefNetworkServices
                              , key, kSCEntNetProxies];
        SCPreferencesPathSetValue(prefRef, (__bridge CFStringRef)prefPath
                                  , (__bridge CFDictionaryRef)proxies);
    }
    SCPreferencesCommitChanges(prefRef);
    SCPreferencesApplyChanges(prefRef);
    SCPreferencesSynchronize(prefRef);

    AuthorizationFree(authRef, kAuthorizationFlagDefaults);
}