Displaying IPv6 addresses with port number in logs

[kabassanov]

Hi,

There is some old code in openvpn stripping tcp/udp ports from ipv6 addresses because "v6addr:port" is too ambiguous. But there is an ipv6 address notation for this, we can simply use [ ] to delimit ipv6 address. So something like this should be enough:

+++ ../openvpn-2.6.14/src/openvpn/mroute.c      2026-01-28 11:51:12.878773385 +0100
@@ -430,9 +430,6 @@ mroute_addr_print_ex(const struct mroute
                 {
                     buf_printf(&out, "%s", print_in_addr_t(maddr.v4mappedv6.addr,
                                                            IA_NET_ORDER, gc));
-                    /* we only print port numbers for v4mapped v6 as of
-                     * today, because "v6addr:port" is too ambiguous
-                     */
                     if (maddr.type & MR_WITH_PORT)
                     {
                         buf_printf(&out, ":%d", ntohs(maddr.v6.port));
@@ -440,7 +437,11 @@ mroute_addr_print_ex(const struct mroute
                 }
                 else
                 {
-                    buf_printf(&out, "%s", print_in6_addr(maddr.v6.addr, 0, gc));
+                    buf_printf(&out, "[%s]", print_in6_addr(maddr.v6.addr, 0, gc));
+                    if (maddr.type & MR_WITH_PORT)
+                    {
+                        buf_printf(&out, ":%d", ntohs(maddr.v6.port));
+                    }
                 }
                 if (maddr.type & MR_WITH_NETBITS)
                 {

What do you think?

[cron2]

please try using "master". That has quite a few changes wrt address printing and different sockets, so might already do what you want.

[kabassanov]

Right. I was just using packet from Debian release...

I wonder why you don't use brackets in general and have different treatments?

      else if (maddr.type & MR_WITH_PORT)
                {
                    buf_printf(&out, "[%s]", print_in6_addr(maddr.v6.addr, 0, gc));
                }
                else
                {
                    buf_printf(&out, "%s", print_in6_addr(maddr.v6.addr, 0, gc));
                }

[schwabe]

Because that is what a lot of people are doing. Printing IPv6 with square brackets when there is no port is quite uncommon.

[cron2]

Personal taste, at least a bit :-) - having IPv6 addresses "always in brackets" is something I find harder to read - with port, you must have it to avoid ambiguity...

[kabassanov]

Although a lot of people do it, there are also some who do not do it :).
I did not check all the code yet, but are there cases where mroute_addr_print is used without port ?