Re: [PATCH v2 net-next] net: drop_monitor: support drop reason

[Menglong Dong]

On Thu, Jan 27, 2022 at 10:48 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Wed, 26 Jan 2022 15:23:06 +0800 menglong8.dong@xxxxxxxxx wrote:
> > @@ -606,12 +610,17 @@ static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
> >  static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
> >                                    size_t payload_len)
> >  {
> > -     u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
> > +     struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb);
> >       char buf[NET_DM_MAX_SYMBOL_LEN];
> > +     enum skb_drop_reason reason;
> >       struct nlattr *attr;
> >       void *hdr;
> > +     u64 pc;
> >       int rc;
> >
> > +     pc = (u64)(uintptr_t)cb->pc;
> > +     reason = cb->reason;
> > +
> >       hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0,
> >                         NET_DM_CMD_PACKET_ALERT);
> >       if (!hdr)
> > @@ -623,6 +632,9 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
> >       if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
> >               goto nla_put_failure;
> >
> > +     if (nla_put_u32(msg, NET_DM_ATTR_REASON, reason))
>
> Why the temporary variable instead of referring to cb->reason directly?

Good question......v3 is coming

>
> > +             goto nla_put_failure;