How to use inet_ntop to detect a VPN?

I support an answer on StackOverflow on how to get active IP addresses on iOS devices (code below). Someone updated it to detect if the device is on a VPN by testing for 'utun0' and/or 'utun1', but the heuristic failed as it seems those are used for other purposes. Is there a way to detect a primary VPN connection?

#include <ifaddrs.h>
#include <arpa/inet.h>
#include <net/if.h>
#define IOS_CELLULAR    @"pdp_ip0"
#define IOS_WIFI        @"en0"
// #define IOS_VPN       @"utun0"
#define IP_ADDR_IPv4    @"ipv4"
#define IP_ADDR_IPv6    @"ipv6"
- (NSString *)getIPAddress:(BOOL)preferIPv4
{
    NSArray *searchArray     preferIPv4 ?
                            @[ /IOS_VPN @"/" IP_ADDR_IPv4, IOS_VPN @"/" IP_ADDR_IPv6,*/ IOS_WIFI @"/" IP_ADDR_IPv4, IOS_WIFI @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6 ] :
                            @[ /IOS_VPN @"/" IP_ADDR_IPv6, IOS_VPN @"/" IP_ADDR_IPv4,*/ IOS_WIFI @"/" IP_ADDR_IPv6, IOS_WIFI @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4 ] ;
    NSDictionary *addresses      [self getIPAddresses];
    NSLog(@"addresses: %@", addresses);
    __block NSString *address;
    [searchArray enumerateObjectsUsingBlock:^(NSString *key, NSUInteger idx, BOOL *stop)
        {
            address      addresses[key];
            if(address) *stop    YES;
        } ];
    return address ? address : @"0.0.0.0";
}
- (NSDictionary *)getIPAddresses
{
    NSMutableDictionary *addresses   [NSMutableDictionary dictionaryWithCapacity:8];
    struct ifaddrs *interfaces;
    if(!getifaddrs(&interfaces)) {
        struct ifaddrs *interface;
        for(interface   interfaces; interface; interface    interface->ifa_next) {
            if(!(interface->ifa_flags & IFF_UP) / || (interface->ifa_flags & IFF_LOOPBACK) */ ) {
                continue; /
            }
            const struct sockaddr_in *addr   (const struct sockaddr_in*)interface->ifa_addr;
            char addrBuf[ MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) ];
            if(addr && (addr->sin_family        AF_INET || addr->sin_family     AF_INET6)) {
                NSString *name   [NSString stringWithUTF8String:interface->ifa_name];
                NSString *type;
                if(addr->sin_family          AF_INET) {
                    if(inet_ntop(AF_INET, &addr->sin_addr, addrBuf, INET_ADDRSTRLEN)) {
                        type     IP_ADDR_IPv4;
                    }
                } else {
                    const struct sockaddr_in6 *addr6     (const struct sockaddr_in6*)interface->ifa_addr;
                    if(inet_ntop(AF_INET6, &addr6->sin6_addr, addrBuf, INET6_ADDRSTRLEN)) {
                        type     IP_ADDR_IPv6;
                    }
                }
                if(type) {
                    NSString *key    [NSString stringWithFormat:@"%@/%@", name, type];
                    addresses[key]   [NSString stringWithUTF8String:addrBuf];
                }
            }
        }
        freeifaddrs(interfaces);
    }
    return [addresses count] ? addresses : nil;
}