netfilter: nft_meta: deal with PACKET_LOOPBACK in netdev family

After adding the following nft rule, then ping 224.0.0.1:
  # nft add rule netdev t c pkttype host counter

The warning complain message will be printed out again and again:
  WARNING: CPU: 0 PID: 10182 at net/netfilter/nft_meta.c:163 \
           nft_meta_get_eval+0x3fe/0x460 [nft_meta]
  [...]
  Call Trace:
  <IRQ>
  dump_stack+0x85/0xc2
  __warn+0xcb/0xf0
  warn_slowpath_null+0x1d/0x20
  nft_meta_get_eval+0x3fe/0x460 [nft_meta]
  nft_do_chain+0xff/0x5e0 [nf_tables]

So we should deal with PACKET_LOOPBACK in netdev family too. For ipv4,
convert it to PACKET_BROADCAST/MULTICAST according to the destination
address's type; For ipv6, convert it to PACKET_MULTICAST directly.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Liping Zhang 2017-01-07 21:33:55 +08:00 committed by Pablo Neira Ayuso
parent 9a6d876262
commit f169fd695b
1 changed files with 27 additions and 1 deletions

View File

@ -156,8 +156,34 @@ void nft_meta_get_eval(const struct nft_expr *expr,
case NFPROTO_IPV6:
*dest = PACKET_MULTICAST;
break;
case NFPROTO_NETDEV:
switch (skb->protocol) {
case htons(ETH_P_IP): {
int noff = skb_network_offset(skb);
struct iphdr *iph, _iph;
iph = skb_header_pointer(skb, noff,
sizeof(_iph), &_iph);
if (!iph)
goto err;
if (ipv4_is_multicast(iph->daddr))
*dest = PACKET_MULTICAST;
else
*dest = PACKET_BROADCAST;
break;
}
case htons(ETH_P_IPV6):
*dest = PACKET_MULTICAST;
break;
default:
WARN_ON_ONCE(1);
goto err;
}
break;
default:
WARN_ON(1);
WARN_ON_ONCE(1);
goto err;
}
break;