Re: [PATCH iproute2-next] ip tunnel: add json output

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu,  1 Aug 2019 12:12:58 +0200
Andrea Claudi <aclaudi@redhat.com> wrote:

> Add json support on iptunnel and ip6tunnel.
> The plain text output format should remain the same.
> 
> Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
> ---
>  ip/ip6tunnel.c | 82 +++++++++++++++++++++++++++++++--------------
>  ip/iptunnel.c  | 90 +++++++++++++++++++++++++++++++++-----------------
>  ip/tunnel.c    | 42 +++++++++++++++++------
>  3 files changed, 148 insertions(+), 66 deletions(-)
> 
> diff --git a/ip/ip6tunnel.c b/ip/ip6tunnel.c
> index d7684a673fdc4..f2b9710c1320f 100644
> --- a/ip/ip6tunnel.c
> +++ b/ip/ip6tunnel.c
> @@ -71,57 +71,90 @@ static void usage(void)
>  static void print_tunnel(const void *t)
>  {
>  	const struct ip6_tnl_parm2 *p = t;
> -	char s1[1024];
> -	char s2[1024];
> +	SPRINT_BUF(b1);
>  
>  	/* Do not use format_host() for local addr,
>  	 * symbolic name will not be useful.
>  	 */
> -	printf("%s: %s/ipv6 remote %s local %s",
> -	       p->name,
> -	       tnl_strproto(p->proto),
> -	       format_host_r(AF_INET6, 16, &p->raddr, s1, sizeof(s1)),
> -	       rt_addr_n2a_r(AF_INET6, 16, &p->laddr, s2, sizeof(s2)));
> +	open_json_object(NULL);
> +	print_string(PRINT_ANY, "ifname", "%s: ", p->name);

Print this using color for interface name?


> +	snprintf(b1, sizeof(b1), "%s/ipv6", tnl_strproto(p->proto));
> +	print_string(PRINT_ANY, "mode", "%s ", b1);
> +	print_string(PRINT_ANY,
> +		     "remote",
> +		     "remote %s ",
> +		     format_host_r(AF_INET6, 16, &p->raddr, b1, sizeof(b1)));
> +	print_string(PRINT_ANY,
> +		     "local",
> +		     "local %s",
> +		     rt_addr_n2a_r(AF_INET6, 16, &p->laddr, b1, sizeof(b1)));
> +
>  	if (p->link) {
>  		const char *n = ll_index_to_name(p->link);
>  
>  		if (n)
> -			printf(" dev %s", n);
> +			print_string(PRINT_ANY, "link", " dev %s", n);
>  	}
>  
>  	if (p->flags & IP6_TNL_F_IGN_ENCAP_LIMIT)
> -		printf(" encaplimit none");
> +		print_bool(PRINT_ANY,
> +			   "ip6_tnl_f_ign_encap_limit",
> +			   " encaplimit none",
> +			   true);

For flags like this, print_null is more typical JSON than a boolean
value. Null is better for presence flag. Bool is better if both true and
false are printed.