Re: [PATCH] net: bonding: Add support for IPV6 ns/na
From: Jay Vosburgh <hidden>
Date: 2021-12-09 20:22:40
Also in:
lkml
Sun Shouxin [off-list ref] wrote:
Since ipv6 neighbor solicitation and advertisement messages isn't handled gracefully in bonding6 driver, we can see packet drop due to inconsistency bewteen mac address in the option message and source MAC .
Could you provide a specific example where this occurs?
Another examples is ipv6 neighbor solicitation and advertisement messages from VM via tap attached to host brighe, the src mac mighe be changed through balance-alb mode, but it is not synced with Link-layer address in the option message.
What happens if the MAC assignment changes because alb does a rebalance?
The patch implements bond6's tx handle for ipv6 neighbor solicitation and advertisement messages.
A few additional minor comments below.
quoted hunk ↗ jump to hunk
Suggested-by: Hu Yadi <redacted> Signed-off-by: Sun Shouxin <redacted> --- drivers/net/bonding/bond_alb.c | 127 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+)diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c index 2ec8e01..01566ba 100644 --- a/drivers/net/bonding/bond_alb.c +++ b/drivers/net/bonding/bond_alb.c@@ -22,6 +22,7 @@#include <asm/byteorder.h> #include <net/bonding.h> #include <net/bond_alb.h> +#include <net/ndisc.h> static const u8 mac_v6_allmcast[ETH_ALEN + 2] __long_aligned = { 0x33, 0x33, 0x00, 0x00, 0x00, 0x01@@ -1269,6 +1270,112 @@ static int alb_set_mac_address(struct bonding *bond, void *addr)return res; } +static void alb_change_nd_option(struct sk_buff *skb, void *data) +{ + struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); + struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)msg->opt; + struct net_device *dev = skb->dev; + struct icmp6hdr *icmp6h = icmp6_hdr(skb); + struct ipv6hdr *ip6hdr = ipv6_hdr(skb); + u8 *lladdr = NULL; + u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) + + offsetof(struct nd_msg, opt)); + + while (ndoptlen) { + int l; + + switch (nd_opt->nd_opt_type) { + case ND_OPT_SOURCE_LL_ADDR: + case ND_OPT_TARGET_LL_ADDR: + lladdr = ndisc_opt_addr_data(nd_opt, dev); + break; + + default: + break; + } + + l = nd_opt->nd_opt_len << 3; + + if (ndoptlen < l || l == 0) + return; + + if (lladdr) { + memcpy(lladdr, data, dev->addr_len); + lladdr = NULL; + icmp6h->icmp6_cksum = 0; + + icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6hdr->saddr, + &ip6hdr->daddr, + ntohs(ip6hdr->payload_len), + IPPROTO_ICMPV6, + csum_partial(icmp6h, + ntohs(ip6hdr->payload_len), 0)); + lladdr = NULL;
"lladdr = NULL" could be in the default: case, above, instead of being done here (and it's here twice).
+ }
+ ndoptlen -= l;
+ nd_opt = ((void *)nd_opt) + l;
+ }
+}
+
+static u8 *alb_get_lladdr(struct sk_buff *skb)
+{
+ struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
+ struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)msg->opt;
+ struct net_device *dev = skb->dev;
+ u8 *lladdr = NULL;
+ u32 ndoptlen = skb_tail_pointer(skb) - (skb_transport_header(skb) +
+ offsetof(struct nd_msg, opt));
+
+ while (ndoptlen) {
+ int l;
+
+ switch (nd_opt->nd_opt_type) {
+ case ND_OPT_SOURCE_LL_ADDR:
+ case ND_OPT_TARGET_LL_ADDR:
+ lladdr = ndisc_opt_addr_data(nd_opt, dev);
+ break;
+
+ default:
+ break;
+ }
+
+ l = nd_opt->nd_opt_len << 3;
+
+ if (ndoptlen < l || l == 0)
+ return lladdr;
+
+ if (lladdr)
+ return lladdr;
+
+ ndoptlen -= l;
+ nd_opt = ((void *)nd_opt) + l;
+ }
+
+ return lladdr;
+}
+
+static void alb_set_nd_option(struct sk_buff *skb, struct bonding *bond,
+ struct slave *tx_slave)
+{
+ struct ipv6hdr *ip6hdr;
+ struct icmp6hdr *hdr = NULL;
+
+ if (tx_slave && tx_slave != rcu_access_pointer(bond->curr_active_slave)) {
+ if (ntohs(skb->protocol) == ETH_P_IPV6) {Nit: use "skb->protocol == htons(ETH_P_IPV6)" as the compiler should optimize the htons() of a constant. Also, you may want to consider reordering the tests here, as IPv6 NA/NS traffic is likely to be the vast minority.
+ ip6hdr = ipv6_hdr(skb);
+ if (ip6hdr->nexthdr == IPPROTO_ICMPV6) {
+ hdr = icmp6_hdr(skb);
+ if (hdr->icmp6_type ==
+ NDISC_NEIGHBOUR_ADVERTISEMENT ||
+ hdr->icmp6_type ==
+ NDISC_NEIGHBOUR_SOLICITATION) {This construct appears twice, perhaps it deserves its own boolean-return function? -J
quoted hunk ↗ jump to hunk
+ alb_change_nd_option(skb, tx_slave->dev->dev_addr); + } + } + } + } +} + /************************ exported alb functions ************************/ int bond_alb_initialize(struct bonding *bond, int rlb_enabled)@@ -1415,6 +1522,7 @@ struct slave *bond_xmit_alb_slave_get(struct bonding *bond,} case ETH_P_IPV6: { const struct ipv6hdr *ip6hdr; + struct icmp6hdr *hdr = NULL; /* IPv6 doesn't really use broadcast mac address, but leave * that here just in case.@@ -1446,6 +1554,24 @@ struct slave *bond_xmit_alb_slave_get(struct bonding *bond,break; } + if (ip6hdr->nexthdr == IPPROTO_ICMPV6) { + hdr = icmp6_hdr(skb); + if (hdr->icmp6_type == + NDISC_NEIGHBOUR_ADVERTISEMENT || + hdr->icmp6_type == + NDISC_NEIGHBOUR_SOLICITATION) { + u8 *lladdr = NULL; + + lladdr = alb_get_lladdr(skb); + if (lladdr) { + if (!bond_slave_has_mac_rx(bond, lladdr)) { + do_tx_balance = false; + break; + } + } + } + } + hash_start = (char *)&ip6hdr->daddr; hash_size = sizeof(ip6hdr->daddr); break;@@ -1489,6 +1615,7 @@ netdev_tx_t bond_alb_xmit(struct sk_buff *skb, struct net_device *bond_dev)struct slave *tx_slave = NULL; tx_slave = bond_xmit_alb_slave_get(bond, skb); + alb_set_nd_option(skb, bond, tx_slave); return bond_do_alb_xmit(skb, bond, tx_slave); } -- 1.8.3.1
--- -Jay Vosburgh, jay.vosburgh@canonical.com