[PATCH v9] net: bonding: Add support for IPV6 ns/na to balance-alb/balance-tlb mode

[PATCH v9] net: bonding: Add support for IPV6 ns/na to balance-alb/balance-tlb mode

[Sun Shouxin]

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: Hu Yadi <huyd12@chinatelecom.cn>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
---
 drivers/net/bonding/bond_alb.c | 38 +++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 533e476988f2..ba7cc1a9bf6c 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -1269,6 +1269,34 @@ 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 icmp6hdr *hdr)
+{
+	if (hdr->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT ||
+	    hdr->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
+		return true;
+	}
+
+	return false;
+}
+
+static bool alb_determine_nd(struct sk_buff *skb, struct bonding *bond)
+{
+	struct ipv6hdr *ip6hdr;
+	struct icmp6hdr *hdr;
+
+	ip6hdr = ipv6_hdr(skb);
+	if (ip6hdr->nexthdr == IPPROTO_ICMPV6) {
+		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr)))
+			return true;
+
+		hdr = icmp6_hdr(skb);
+		return __alb_determine_nd(hdr);
+	}
+
+	return false;
+}
+
 /************************ exported alb functions ************************/
 
 int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
@@ -1348,8 +1376,11 @@ struct slave *bond_xmit_tlb_slave_get(struct bonding *bond,
 	/* Do not TX balance any multicast or broadcast */
 	if (!is_multicast_ether_addr(eth_data->h_dest)) {
 		switch (skb->protocol) {
-		case htons(ETH_P_IP):
 		case htons(ETH_P_IPV6):
+			if (alb_determine_nd(skb, bond))
+				break;
+			fallthrough;
+		case htons(ETH_P_IP):
 			hash_index = bond_xmit_hash(bond, skb);
 			if (bond->params.tlb_dynamic_lb) {
 				tx_slave = tlb_choose_channel(bond,
@@ -1446,6 +1477,11 @@ struct slave *bond_xmit_alb_slave_get(struct bonding *bond,
 			break;
 		}
 
+		if (alb_determine_nd(skb, bond)) {
+			do_tx_balance = false;
+			break;
+		}
+
 		hash_start = (char *)&ip6hdr->daddr;
 		hash_size = sizeof(ip6hdr->daddr);
 		break;

base-commit: dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0
-- 
2.27.0

Re: [PATCH v9] net: bonding: Add support for IPV6 ns/na to balance-alb/balance-tlb mode

[Nikolay Aleksandrov]

On 25/01/2022 04:37, Sun Shouxin wrote:
> 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: Hu Yadi <huyd12@chinatelecom.cn>
> Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
> Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
> ---
>  drivers/net/bonding/bond_alb.c | 38 +++++++++++++++++++++++++++++++++-
>  1 file changed, 37 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 533e476988f2..ba7cc1a9bf6c 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -1269,6 +1269,34 @@ 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 icmp6hdr *hdr)
> +{
> +	if (hdr->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT ||
> +	    hdr->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
> +static bool alb_determine_nd(struct sk_buff *skb, struct bonding *bond)
> +{
> +	struct ipv6hdr *ip6hdr;
> +	struct icmp6hdr *hdr;
> +
> +	ip6hdr = ipv6_hdr(skb);

You can't do this in bond_xmit_tlb_slave_get(), there's no check if the IPv6 header
is in the linear part before calling alb_determine_nd() there. You can combine
bond_xmit_alb_slave_get's IPv6 header pull with alb_determine_nd's, just please leave
a comment above the call in bond_xmit_alb_slave_get() that the IPv6 header is pulled by
alb_determine_nd.

> +	if (ip6hdr->nexthdr == IPPROTO_ICMPV6) {
> +		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + sizeof(struct icmp6hdr)))
> +			return true;

This could invalidate current pointers to skb data, more below...

> +
> +		hdr = icmp6_hdr(skb);
> +		return __alb_determine_nd(hdr);
> +	}
> +
> +	return false;
> +}
> +
>  /************************ exported alb functions ************************/
>  
>  int bond_alb_initialize(struct bonding *bond, int rlb_enabled)
> @@ -1348,8 +1376,11 @@ struct slave *bond_xmit_tlb_slave_get(struct bonding *bond,
>  	/* Do not TX balance any multicast or broadcast */
>  	if (!is_multicast_ether_addr(eth_data->h_dest)) {
>  		switch (skb->protocol) {
> -		case htons(ETH_P_IP):
>  		case htons(ETH_P_IPV6):
> +			if (alb_determine_nd(skb, bond))
> +				break;
> +			fallthrough;
> +		case htons(ETH_P_IP):
>  			hash_index = bond_xmit_hash(bond, skb);
>  			if (bond->params.tlb_dynamic_lb) {
>  				tx_slave = tlb_choose_channel(bond,
> @@ -1446,6 +1477,11 @@ struct slave *bond_xmit_alb_slave_get(struct bonding *bond,
>  			break;
>  		}
>  
> +		if (alb_determine_nd(skb, bond)) {
> +			do_tx_balance = false;
> +			break;
> +		}
> +
>  		hash_start = (char *)&ip6hdr->daddr;
>  		hash_size = sizeof(ip6hdr->daddr);

... here you have to reload ip6hdr, but that can be avoided in a few different ways.
I.e. you could move alb_determine_nd() before the assignment of that ptr.

>  		break;
> 
> base-commit: dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0

Re: [PATCH v9] net: bonding: Add support for IPV6 ns/na to balance-alb/balance-tlb mode

[Nikolay Aleksandrov]

On 25/01/2022 10:51, Nikolay Aleksandrov wrote:
> On 25/01/2022 04:37, Sun Shouxin wrote:
>> 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: Hu Yadi <huyd12@chinatelecom.cn>
>> Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
>> Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
>> ---
>>  drivers/net/bonding/bond_alb.c | 38 +++++++++++++++++++++++++++++++++-
>>  1 file changed, 37 insertions(+), 1 deletion(-)
>>
[snip]

Also forgot to mention, you should add a changelog between patch versions.
You can add it below the --- marker so it won't be included in the commit
message. Otherwise it's hard to track how the patch reached v9 and what
changed between versions.

E.g. v8 -> v9: <changed blah>

Thanks,
 Nik

Re: [PATCH v9] net: bonding: Add support for IPV6 ns/na to balance-alb/balance-tlb mode

[孙守鑫]

在 2022/1/25 17:02, Nikolay Aleksandrov 写道:
> On 25/01/2022 10:51, Nikolay Aleksandrov wrote:
>> On 25/01/2022 04:37, Sun Shouxin wrote:
>>> 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: Hu Yadi <huyd12@chinatelecom.cn>
>>> Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
>>> Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
>>> ---
>>>   drivers/net/bonding/bond_alb.c | 38 +++++++++++++++++++++++++++++++++-
>>>   1 file changed, 37 insertions(+), 1 deletion(-)
>>>
> [snip]
>
> Also forgot to mention, you should add a changelog between patch versions.
> You can add it below the --- marker so it won't be included in the commit
> message. Otherwise it's hard to track how the patch reached v9 and what
> changed between versions.
>
> E.g. v8 -> v9: <changed blah>
>
> Thanks,
>   Nik
>
>

Thanks your comment, I'll adjust it and send out V10 soon.