iOSは現在のデバイスIPアドレスを取得

// ip 
- (NSString *)getDeviceIpAddresses {
    int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0) return nil;
    NSMutableArray *ips = [NSMutableArray array];
    
    int BUFFERSIZE = 4096;
    struct ifconf ifc;
    char buffer[BUFFERSIZE], *ptr, lastname[IFNAMSIZ], *cptr;
    struct ifreq *ifr, ifrcopy;
    ifc.ifc_len = BUFFERSIZE;
    ifc.ifc_buf = buffer;
    if (ioctl(sockfd, SIOCGIFCONF, &ifc) >= 0){
        for (ptr = buffer; ptr < buffer + ifc.ifc_len; ){
            ifr = (struct ifreq *)ptr;
            int len = sizeof(struct sockaddr);
            if (ifr->ifr_addr.sa_len > len) {
                len = ifr->ifr_addr.sa_len;
            }
            ptr += sizeof(ifr->ifr_name) + len;
            if (ifr->ifr_addr.sa_family != AF_INET) continue;
            if ((cptr = (char *)strchr(ifr->ifr_name, ':')) != NULL) *cptr = 0;
            if (strncmp(lastname, ifr->ifr_name, IFNAMSIZ) == 0) continue;
            memcpy(lastname, ifr->ifr_name, IFNAMSIZ);
            ifrcopy = *ifr;
            ioctl(sockfd, SIOCGIFFLAGS, &ifrcopy);
            if ((ifrcopy.ifr_flags & IFF_UP) == 0) continue;
            
            NSString *ip = [NSString stringWithFormat:@"%s", inet_ntoa(((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr)];
            [ips addObject:ip];
        }
    }
    close(sockfd);
    NSString *address=[ips lastObject];
    return address;
}