Give precedence to hosts file over DNS for name resolution

edit

This would be a new feature or Enhancement request. They are created on the Wireshark Gitlab Issues page. (If you open an issue please add a link back to this question.)

What's happening:
Last one in wins. This is how the global hosts file is superseded by entries in the personal hosts.
When an entry come in from DNS it updates the hash table.

What you're looking for is sort of like nsswitch.conf setting the order or precedence of checking. I'm not sure if this would need to be another Name Resolution preference or if hosts entries always win.

The address hash table hashipv4_t (wtap.h) does have a flags field that might be used to implement this. If an entry is added in read_hosts_file(), set the flag bit so the entry is not updated by DNS.

packet-dns.c:

    case T_A: /* a host Address (1) */
...
        add_ipv4_name(addr_int, name);
...
    case T_AAAA: /* IPv6 Address (28) */
...
        add_ipv6_name(&addr_in6, name);

addr_resolv.c:

add_ipv4_name(const guint addr, const gchar *name)
...
    tp = (hashipv4_t *)wmem_map_lookup(ipv4_hash_table, GUINT_TO_POINTER(addr));
    if (!tp) {
        tp = new_ipv4(addr);
        wmem_map_insert(ipv4_hash_table, GUINT_TO_POINTER(addr), tp);
    }

    if (g_ascii_strcasecmp(tp->name, name)) {
        (void) g_strlcpy(tp->name, name, MAXNAMELEN);
        new_resolved_objects = TRUE;
    }