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net: ethernet: Drop pkt if MAC dst is bcast address but IP is not

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Drop packet if it has broadcast destination MAC address but the IPv4
destination address is not multicast or broadcast address.
See RFC 1122 ch 3.3.6 for details.

Fixes #16276

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
This commit is contained in:
Jukka Rissanen 2019-05-21 13:33:23 +03:00
commit 19b48687ec
1 changed files with 24 additions and 2 deletions
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26
subsys/net/l2/ethernet/ethernet.c
View file

@ -145,6 +145,23 @@ static inline bool eth_is_vlan_tag_stripped(struct net_if *iface)
return (api->get_capabilities(dev) & ETHERNET_HW_VLAN_TAG_STRIP);
}
/* Drop packet if it has broadcast destination MAC address but the IP
* address is not multicast or broadcast address. See RFC 1122 ch 3.3.6
*/
static inline
enum net_verdict ethernet_check_ipv4_bcast_addr(struct net_pkt *pkt,
struct net_eth_hdr *hdr)
{
if (net_eth_is_addr_broadcast(&hdr->dst) &&
!(net_ipv4_is_addr_mcast(&NET_IPV4_HDR(pkt)->dst) ||
net_ipv4_is_addr_bcast(net_pkt_iface(pkt),
&NET_IPV4_HDR(pkt)->dst))) {
return NET_DROP;
}
return NET_OK;
}
static enum net_verdict ethernet_recv(struct net_if *iface,
struct net_pkt *pkt)
{
@ -240,10 +257,15 @@ static enum net_verdict ethernet_recv(struct net_if *iface,
goto drop;
}
ethernet_update_rx_stats(iface, pkt, net_pkt_get_len(pkt));
net_buf_pull(pkt->frags, hdr_len);
if (IS_ENABLED(CONFIG_NET_IPV4) && type == NET_ETH_PTYPE_IP &&
ethernet_check_ipv4_bcast_addr(pkt, hdr) == NET_DROP) {
goto drop;
}
ethernet_update_rx_stats(iface, pkt, net_pkt_get_len(pkt) + hdr_len);
#ifdef CONFIG_NET_ARP
if (family == AF_INET && type == NET_ETH_PTYPE_ARP) {
NET_DBG("ARP packet from %s received",