net: ipv4: Drop packet if source address is my address

jukkar · cfriedt · commit 32748c69b898 · 2024-01-03T13:13:51.000-05:00
If we receive a packet where the source address is our own address, then we should drop it. Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no> (cherry picked from commit 19392a6)
diff --git a/subsys/net/ip/ipv4.c b/subsys/net/ip/ipv4.c
@@ -272,6 +272,11 @@ enum net_verdict net_ipv4_input(struct net_pkt *pkt, bool is_loopback)
 			NET_DBG("DROP: localhost packet");
 			goto drop;
 		}
+
+		if (net_ipv4_is_my_addr(&hdr->src)) {
+			NET_DBG("DROP: src addr is %s", "mine");
+			goto drop;
+		}
 	}
 
 	if (net_ipv4_is_addr_mcast(&hdr->src)) {

Original file line number	Diff line number	Diff line change
`@@ -272,6 +272,11 @@ enum net_verdict net_ipv4_input(struct net_pkt *pkt, bool is_loopback)`
`272`	`272`	`NET_DBG("DROP: localhost packet");`
`273`	`273`	`goto drop;`
`274`	`274`	`}`
	`275`	`+`
	`276`	`+ if (net_ipv4_is_my_addr(&hdr->src)) {`
	`277`	`+ NET_DBG("DROP: src addr is %s", "mine");`
	`278`	`+ goto drop;`
	`279`	`+ }`
`275`	`280`	`}`
`276`	`281`
`277`	`282`	`if (net_ipv4_is_addr_mcast(&hdr->src)) {`