Re: [PATCH] iproute2: add 64bit support to ifstat

Stephen Hemminger
2010-08-23T17:33:35Z

On Mon, 23 Aug 2010 18:54:24 +0200
Eric Dumazet <eric.dumazet@gmail.com> wrote:

> Le lundi 23 août 2010 à 09:17 -0700, Stephen Hemminger a écrit :
> > On Mon, 23 Aug 2010 16:43:23 +0100
> > Ben Hutchings <bhutchings@solarflare.com> wrote:
> >
> > > On Mon, 2010-08-23 at 08:32 -0700, Stephen Hemminger wrote:
> > > > This commit broke iproute2 build:
> > > >
> > > > commit be1f3c2c027cc5ad735df6a45a542ed1db7ec48b
> > > > Author: Ben Hutchings <bhutchings@solarflare.com>
> > > > Date: Tue Jun 8 07:19:54 2010 +0000
> > > >
> > > > net: Enable 64-bit net device statistics on 32-bit architectures
> > > >
> > > > Use struct rtnl_link_stats64 as the statistics structure.
> > > >
> > > > Iproute2 uses a the kernel exported headers, and the structure
> > > > net_device_stats which is part of the netlink IFLA_STATS message
> > > > was no longer exposed.
> > > [...]
> > >
> > > This is not true; the kernel uses struct rtnl_link_stats for IFLA_STATS.
> > > AFAICS the only reference to struct net_device_stats in iproute2 is:
> > >
> > > misc/ifstat.c:51:#define MAXS (sizeof(struct net_device_stats)/sizeof(unsigned long))
> > >
> > > This should be changed to refer to the structure that is actually used.
> >
> > Ok.
>
> Stephen,
>
> Here is a patch to ifstat on top of your last one.
>
> I guess nobody tried it on a 64bit platform...
>
> Thanks
>
> iproute2: add 64bit support to ifstat
>
> ifstat assumes IFLA_STATS fields are "unsigned long"
>
> ifstat can use 64bit stats if available (IFLA_STATS64)
>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ---
>
> diff --git a/misc/ifstat.c b/misc/ifstat.c
> index 5cf2e01..c649ee2 100644
> --- a/misc/ifstat.c
> +++ b/misc/ifstat.c
> @@ -49,7 +49,7 @@ int npatterns;
> char info_source[128];
> int source_mismatch;
>
> -#define MAXS (sizeof(struct rtnl_link_stats)/sizeof(unsigned long))
> +#define MAXS (sizeof(struct rtnl_link_stats)/sizeof(__u32))
>
> struct ifstat_ent
> {
> @@ -58,7 +58,7 @@ struct ifstat_ent
> int ifindex;
> unsigned long long val[MAXS];
> double rate[MAXS];
> - unsigned long ival[MAXS];
> + __u32 ival[MAXS];
> };
>
> struct ifstat_ent *kern_db;
> @@ -108,8 +108,12 @@ static int get_nlmsg(const struct sockaddr_nl *who,
> n->name = strdup(RTA_DATA(tb[IFLA_IFNAME]));
> memcpy(&n->ival, RTA_DATA(tb[IFLA_STATS]), sizeof(n->ival));
> memset(&n->rate, 0, sizeof(n->rate));
> - for (i=0; i<MAXS; i++)
> - n->val[i] = n->ival[i];
> + if (tb[IFLA_STATS64])
> + memcpy(&n->val, RTA_DATA(tb[IFLA_STATS64]), sizeof(n->val));
> + else
> + for (i = 0; i < MAXS; i++)
> + n->val[i] = n->ival[i];
> +
> n->next = kern_db;
> kern_db = n;
> return 0;
>
>

I think this breaks the wraparound detection code in this command.

--