net: bonding: Add support for IPV6 ns/na to balance-alb/balance-tlb mode

mainline inclusion
from mainline-v5.4
commit 0da8aa00
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5UY5E
CVE: NA

--------------------------------

Since ipv6 neighbor solicitation and advertisement messages
isn't handled gracefully in bond6 driver, we can see packet
drop due to inconsistency between mac address in the option
message and source MAC .

Another examples is ipv6 neighbor solicitation and advertisement
messages from VM via tap attached to host bridge, the src mac
might be changed through balance-alb mode, but it is not synced
with Link-layer address in the option message.

The patch implements bond6's tx handle for ipv6 neighbor
solicitation and advertisement messages.
Suggested-by: NHu Yadi <huyd12@chinatelecom.cn>
Acked-by: NJay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: NSun Shouxin <sunshouxin@chinatelecom.cn>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSun Shouxin <sunshouxin@chinatelecom.cn>

drivers/net/bonding/bond_alb.c

@@ -1281,6 +1281,27 @@ static int alb_set_mac_address(struct bonding *bond, void *addr)
 	return res;
 }
 
+/* determine if the packet is NA or NS */
+static bool alb_determine_nd(struct sk_buff *skb, struct bonding *bond)
+{
+	struct ipv6hdr *ip6hdr;
+	struct icmp6hdr *hdr;
+
+	if (!pskb_network_may_pull(skb, sizeof(*ip6hdr)))
+		return true;
+
+	ip6hdr = ipv6_hdr(skb);
+	if (ip6hdr->nexthdr != IPPROTO_ICMPV6)
+		return false;
+
+	if (!pskb_network_may_pull(skb, sizeof(*ip6hdr) + sizeof(*hdr)))
+		return true;
+
+	hdr = icmp6_hdr(skb);
+	return hdr->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT ||
+		hdr->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION;
+}
+
 /************************ exported alb funcions ************************/
 
 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
@@ -1363,10 +1384,13 @@ netdev_tx_t bond_tlb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
 	/* Do not TX balance any multicast or broadcast */
 	if (!is_multicast_ether_addr(eth_data->h_dest)) {
 		switch (skb->protocol) {
+		case htons(ETH_P_IPV6):
+			if (alb_determine_nd(skb, bond))
+				break;
+			/* fallthrough */
 		case htons(ETH_P_IP):
 		case htons(ETH_P_IPX):
 		    /* In case of IPX, it will falback to L2 hash */
-		case htons(ETH_P_IPV6):
 			hash_index = bond_xmit_hash(bond, skb);
 			if (bond->params.tlb_dynamic_lb) {
 				tx_slave = tlb_choose_channel(bond,
@@ -1440,10 +1464,12 @@ netdev_tx_t bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)
 			break;
 		}
 
-		if (!pskb_network_may_pull(skb, sizeof(*ip6hdr))) {
+		if (alb_determine_nd(skb, bond)) {
 			do_tx_balance = false;
 			break;
 		}
+
+		/* The IPv6 header is pulled by alb_determine_nd */
 		/* Additionally, DAD probes should not be tx-balanced as that
 		 * will lead to false positives for duplicate addresses and
 		 * prevent address configuration from working.