ipv4: Add ICMPv6 support when parse route ipproto

For ip rules, we need to use 'ipproto ipv6-icmp' to match ICMPv6 headers.
But for ip -6 route, currently we only support tcp, udp and icmp.

Add ICMPv6 support so we can match ipv6-icmp rules for route lookup.

v2: As David Ahern and Sabrina Dubroca suggested, Add an argument to
rtm_getroute_parse_ip_proto() to handle ICMP/ICMPv6 with different family.
Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: eacb9384 ("ipv6: support sport, dport and ip_proto in RTM_GETROUTE")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip.h

@@ -718,7 +718,7 @@ extern int sysctl_icmp_msgs_burst;
 int ip_misc_proc_init(void);
 #endif
 
-int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto,
+int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
 				struct netlink_ext_ack *extack);
 
 #endif	/* _IP_H */

net/ipv4/netlink.c

@@ -3,9 +3,10 @@
 #include <linux/types.h>
 #include <net/net_namespace.h>
 #include <net/netlink.h>
+#include <linux/in6.h>
 #include <net/ip.h>
 
-int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto,
+int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
 				struct netlink_ext_ack *extack)
 {
 	*ip_proto = nla_get_u8(attr);
@@ -13,11 +14,19 @@ int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto,
 	switch (*ip_proto) {
 	case IPPROTO_TCP:
 	case IPPROTO_UDP:
+		return 0;
 	case IPPROTO_ICMP:
+		if (family != AF_INET)
+			break;
+		return 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	case IPPROTO_ICMPV6:
+		if (family != AF_INET6)
+			break;
 		return 0;
-	default:
-		NL_SET_ERR_MSG(extack, "Unsupported ip proto");
-		return -EOPNOTSUPP;
+#endif
 	}
+	NL_SET_ERR_MSG(extack, "Unsupported ip proto");
+	return -EOPNOTSUPP;
 }
 EXPORT_SYMBOL_GPL(rtm_getroute_parse_ip_proto);

net/ipv4/route.c

@@ -2803,7 +2803,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 
 	if (tb[RTA_IP_PROTO]) {
 		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
-						  &ip_proto, extack);
+						  &ip_proto, AF_INET, extack);
 		if (err)
 			return err;
 	}

net/ipv6/route.c

@@ -4893,7 +4893,8 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 
 	if (tb[RTA_IP_PROTO]) {
 		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
-						  &fl6.flowi6_proto, extack);
+						  &fl6.flowi6_proto, AF_INET6,
+						  extack);
 		if (err)
 			goto errout;
 	}