Re: [PATCH] ss: Enclose IPv6 address in brackets

On Mon, 31 Jul 2017 12:30:10 +0200
Phil Sutter [off-list ref] wrote:

On Sat, Jul 29, 2017 at 02:29:10PM +0200, Florian Lehner wrote:

quoted

This patch adds support for RFC2732 IPv6 address format with brackets
for the tool ss. So output for ss changes from
2a00:1450:400a:804::200e:443 to [2a00:1450:400a:804::200e]:443 for IPv6
addresses with attached port number.

Signed-off-by: Lehner Florian <redacted>
---
 misc/ss.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/misc/ss.c b/misc/ss.c
index 12763c9..db39c93 100644
--- a/misc/ss.c
+++ b/misc/ss.c

@@ -1059,7 +1059,11 @@ static void inet_addr_print(const inet_prefix *a,

int port, unsigned int ifindex
 			ap = format_host(AF_INET, 4, a->data);
 		}
 	} else {
-		ap = format_host(a->family, 16, a->data);
+		if (a->family == AF_INET6) {
+			sprintf(buf, "[%s]", format_host(a->family, 16, a->data));
+		} else {
+			ap = format_host(a->family, 16, a->data);
+		}
 		est_len = strlen(ap);
 		if (est_len <= addr_width)
 			est_len = addr_width;  

Note that this will enclosed resolved hostnames in brackets as well, not
sure if that's intended. Looks like fixing that is not exactly trivial:
Hostname resolution is buried in format_host() which resides in
lib/utils.c so is shared code with ip, tc, etc. Hence, adding the
brackets in rt_addr_n2a_r() is not an option, either. Adding a 'bool *'
param to format_host() and format_host_r() indicating that name
resolution has happened might help here.

Cheers, Phil

Also, this code should return "*" for IN6ADDR_ANY