`validate_ip_address` method in `util.c` file does not check for address family mismatch

[lokeshmuthuraj]

Issue

• validate_ip_address method in util.c file does not check for address family mismatch
• Allows incompatible combinations to pass early validation and only fail during runtime when connections are being established.
• -6 -a 1.2.3.4 & -a ::1 pass early validation but fail during runtime.

Impact

This results in poor user experience with delayed error reporting.

Code

int validate_ip_address(const char *ip_str) 
{
    struct in_addr ipv4_addr;
    struct in6_addr ipv6_addr;

    if (inet_pton(AF_INET, ip_str, &ipv4_addr) == 1) {
        return NO_ERROR;  // Accepts IPv4
    } else if (inet_pton(AF_INET6, ip_str, &ipv6_addr) == 1) {
        return NO_ERROR;  // Accepts IPv6
    }
    return ERROR_ARGS;
}

ntttcp_update_client_info method in util.c file:

if (sc->domain == AF_INET) {
    if (sc->use_client_address) {
        if (inet_pton(AF_INET, sc->client_address, ...) <= 0) {
            // FAILS here if IPv6 address with IPv4 domain
            return ERROR_ARGS;
        }
    }
} else {
    if (sc->use_client_address) {
        if (inet_pton(AF_INET6, sc->client_address, ...) <= 0) {
            // FAILS here if IPv4 address with IPv6 domain
            return ERROR_ARGS;
        }
    }
}