Re: [PATCH net-next RESEND] net: bonding: add bond_is_icmpv6_nd() helper

[Hangbin Liu <liuhangbin@gmail.com>]

On Tue, Jul 08, 2025 at 08:32:51PM +0800, Tonghao Zhang wrote:
> Introduce ipv6 ns/nd checking helper, using skb_header_pointer()
> instead of pskb_network_may_pull() on tx path.
> 
> alb_determine_nd introduced from commit 0da8aa00bfcfe
> 
> Cc: Jay Vosburgh <jv@jvosburgh.net>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Simon Horman <horms@kernel.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Andrew Lunn <andrew+netdev@lunn.ch>
> Cc: Nikolay Aleksandrov <razor@blackwall.org>
> Signed-off-by: Tonghao Zhang <tonghao@bamaicloud.com>
> Signed-off-by: Zengbing Tu <tuzengbing@didiglobal.com>
> ---
>  drivers/net/bonding/bond_alb.c  | 32 +++++++-------------------------
>  drivers/net/bonding/bond_main.c | 17 ++---------------
>  include/net/bonding.h           | 19 +++++++++++++++++++
>  3 files changed, 28 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 2d37b07c8215..8e5b9ce52077 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -19,7 +19,6 @@
>  #include <linux/in.h>
>  #include <net/arp.h>
>  #include <net/ipv6.h>
> -#include <net/ndisc.h>
>  #include <asm/byteorder.h>
>  #include <net/bonding.h>
>  #include <net/bond_alb.h>
> @@ -1280,27 +1279,6 @@ 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 functions ************************/
>  
>  int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
> @@ -1381,7 +1359,7 @@ struct slave *bond_xmit_tlb_slave_get(struct bonding *bond,
>  	if (!is_multicast_ether_addr(eth_data->h_dest)) {
>  		switch (skb->protocol) {
>  		case htons(ETH_P_IPV6):
> -			if (alb_determine_nd(skb, bond))
> +			if (bond_is_icmpv6_nd(skb))
>  				break;
>  			fallthrough;
>  		case htons(ETH_P_IP):
> @@ -1467,16 +1445,20 @@ struct slave *bond_xmit_alb_slave_get(struct bonding *bond,
>  			break;
>  		}
>  
> -		if (alb_determine_nd(skb, bond)) {
> +		if (bond_is_icmpv6_nd(skb)) {
>  			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.
>  		 */
> +		if (!pskb_network_may_pull(skb, sizeof(*ip6hdr))) {
> +			do_tx_balance = false;
> +			break;
> +		}
> +
>  		ip6hdr = ipv6_hdr(skb);
>  		if (ipv6_addr_any(&ip6hdr->saddr)) {
>  			do_tx_balance = false;
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 17c7542be6a5..a8034a561011 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -5338,10 +5338,6 @@ static bool bond_should_broadcast_neighbor(struct sk_buff *skb,
>  					   struct net_device *dev)
>  {
>  	struct bonding *bond = netdev_priv(dev);
> -	struct {
> -		struct ipv6hdr ip6;
> -		struct icmp6hdr icmp6;
> -	} *combined, _combined;
>  
>  	if (!static_branch_unlikely(&bond_bcast_neigh_enabled))
>  		return false;
> @@ -5349,19 +5345,10 @@ static bool bond_should_broadcast_neighbor(struct sk_buff *skb,
>  	if (!bond->params.broadcast_neighbor)
>  		return false;
>  
> -	if (skb->protocol == htons(ETH_P_ARP))
> +	if (skb->protocol == htons(ETH_P_ARP) ||
> +	    (skb->protocol == htons(ETH_P_IPV6) && bond_is_icmpv6_nd(skb)))
>  		return true;
>  
> -	if (skb->protocol == htons(ETH_P_IPV6)) {
> -		combined = skb_header_pointer(skb, skb_mac_header_len(skb),
> -					      sizeof(_combined),
> -					      &_combined);
> -		if (combined && combined->ip6.nexthdr == NEXTHDR_ICMP &&
> -		    (combined->icmp6.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
> -		     combined->icmp6.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT))
> -			return true;
> -	}
> -
>  	return false;
>  }
>  
> diff --git a/include/net/bonding.h b/include/net/bonding.h
> index e06f0d63b2c1..32d9fcca858c 100644
> --- a/include/net/bonding.h
> +++ b/include/net/bonding.h
> @@ -29,6 +29,7 @@
>  #include <net/bond_options.h>
>  #include <net/ipv6.h>
>  #include <net/addrconf.h>
> +#include <net/ndisc.h>
>  
>  #define BOND_MAX_ARP_TARGETS	16
>  #define BOND_MAX_NS_TARGETS	BOND_MAX_ARP_TARGETS
> @@ -814,4 +815,22 @@ static inline netdev_tx_t bond_tx_drop(struct net_device *dev, struct sk_buff *s
>  	return NET_XMIT_DROP;
>  }
>  
> +static inline bool bond_is_icmpv6_nd(struct sk_buff *skb)
> +{
> +	struct {
> +		struct ipv6hdr ip6;
> +		struct icmp6hdr icmp6;
> +	} *combined, _combined;
> +
> +	combined = skb_header_pointer(skb, skb_mac_header_len(skb),
> +				      sizeof(_combined),
> +				      &_combined);
> +	if (combined && combined->ip6.nexthdr == NEXTHDR_ICMP &&
> +	    (combined->icmp6.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
> +	     combined->icmp6.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT))
> +		return true;
> +
> +	return false;
> +}
> +
>  #endif /* _NET_BONDING_H */
> -- 
> 2.34.1
> 

Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>