Re: [patch iproute2-next 2/4] devlink: introduce support for netns id for nested handle

[David Ahern <dsahern@gmail.com>]

On 9/18/23 4:54 AM, Jiri Pirko wrote:
>  static const enum mnl_attr_data_type
> @@ -2723,6 +2725,85 @@ static bool should_arr_last_handle_end(struct dl *dl, const char *bus_name,
>  	       !cmp_arr_last_handle(dl, bus_name, dev_name);
>  }
>  
> +static int32_t netns_id_by_name(const char *name)
> +{
> +	struct {
> +		struct nlmsghdr n;
> +		struct rtgenmsg g;
> +		char            buf[1024];
> +	} req = {
> +		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
> +		.n.nlmsg_flags = NLM_F_REQUEST,
> +		.n.nlmsg_type = RTM_GETNSID,
> +		.g.rtgen_family = AF_UNSPEC,
> +	};
> +	int ret = NETNSA_NSID_NOT_ASSIGNED;
> +	struct rtattr *tb[NETNSA_MAX + 1];
> +	struct nlmsghdr *n = NULL;
> +	struct rtnl_handle rth;
> +	struct rtgenmsg *rtg;
> +	int len;
> +	int fd;
> +
> +	fd = netns_get_fd(name);
> +	if (fd < 0)
> +		return ret;
> +
> +	if (rtnl_open(&rth, 0) < 0)
> +		return ret;
> +
> +	addattr32(&req.n, sizeof(req), NETNSA_FD, fd);
> +	if (rtnl_talk(&rth, &req.n, &n) < 0)
> +		goto out;
> +
> +	if (n->nlmsg_type == NLMSG_ERROR)
> +		goto out;
> +
> +	rtg = NLMSG_DATA(n);
> +	len = n->nlmsg_len;
> +
> +	len -= NLMSG_SPACE(sizeof(*rtg));
> +	if (len < 0)
> +		goto out;
> +
> +	parse_rtattr(tb, NETNSA_MAX, NETNS_RTA(rtg), len);
> +	if (tb[NETNSA_NSID])
> +		ret = rta_getattr_s32(tb[NETNSA_NSID]);
> +
> +out:
> +	free(n);
> +	rtnl_close(&rth);
> +	close(fd);
> +	return ret;
> +}

duplicates get_netnsid_from_name