On Thu, 24 Sep 2020 00:45:10 +0200 Michal Kubecek wrote:
> > + if (mnl_attr_validate(tb[stats[i].attr], MNL_TYPE_U64)) {
> > + fprintf(stderr, "malformed netlink message
> > (statistic)\n");
> > + goto err_close_stats;
> > + }
> > +
> > + n = snprintf(fmt, sizeof(fmt), " %s: %%" PRId64 "\n",
> > + stats[i].name);
>
> The stats are unsigned so the format should be PRIu64 here.
Good catch.
> > @@ -173,8 +236,9 @@ int nl_gpause(struct cmd_context *ctx)
> > return 1;
> > }
> >
> > + flags = nlctx->ctx->show_stats ? ETHTOOL_FLAG_STATS : 0;
> > ret = nlsock_prep_get_request(nlsk, ETHTOOL_MSG_PAUSE_GET,
> > - ETHTOOL_A_PAUSE_HEADER, 0);
> > + ETHTOOL_A_PAUSE_HEADER, flags);
> > if (ret < 0)
> > return ret;
> >
>
> When the stats are supported by kernel but not provided by a device,
> the request will succeed and usual output without stats will be shown.
> However, when stats are requested on a pre-5.10 kernel not recognizing
> ETHTOOL_FLAG_STATS, the request will fail:
>
> mike@lion:~/work/git/ethtool> ./ethtool --debug 0x10 -I -a eth0
> netlink error: unrecognized request flags
> netlink error: Operation not supported
> offending message and attribute:
> ETHTOOL_MSG_PAUSE_GET
> ETHTOOL_A_PAUSE_HEADER
> ETHTOOL_A_HEADER_DEV_NAME = "eth0"
> ===> ETHTOOL_A_HEADER_FLAGS = 0x00000004
>
> We should probably repeat the request with flags=0 in this case but that
> would require keeping the offset of ETHTOOL_A_HEADER_FLAGS attribute and
> checking for -EOPNOTSUPP with this offset in nlsock_process_ack().
Makes sense, will do.
