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Message-ID: <20251021144410.257905-8-skorodumov.dmitry@huawei.com>
Date: Tue, 21 Oct 2025 17:44:09 +0300
From: Dmitry Skorodumov <skorodumov.dmitry@...wei.com>
To: <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>
CC: <andrey.bokhanko@...wei.com>, Dmitry Skorodumov
<skorodumov.dmitry@...wei.com>, Andrew Lunn <andrew+netdev@...n.ch>, "David
S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub
Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Subject: [PATCH net-next 7/8] ipvlan: Support IPv6 for learnable l2-bridge
To make IPv6 work with learnable l2-bridge, need to
process the TX-path:
* Replace Source-ll-addr in Solicitation ndisc,
* Replace Target-ll-addr in Advertisement ndisc
No need to do anything in RX-path
Signed-off-by: Dmitry Skorodumov <skorodumov.dmitry@...wei.com>
---
drivers/net/ipvlan/ipvlan_core.c | 125 +++++++++++++++++++++++++++----
1 file changed, 111 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index fe8e59066c46..ce06a06d8a28 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -738,11 +738,117 @@ static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)
return ipvlan_process_outbound(skb);
}
+static void ipvlan_snat_patch_tx_arp(struct ipvl_dev *ipvlan,
+ struct sk_buff *skb)
+{
+ int addr_type;
+ struct arphdr *arph;
+
+ arph = (struct arphdr *)ipvlan_get_L3_hdr(ipvlan->port, skb,
+ &addr_type);
+ ether_addr_copy((u8 *)(arph + 1), ipvlan->phy_dev->dev_addr);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+
+static u8 *ipvlan_search_icmp6_ll_addr(struct sk_buff *skb, u8 icmp_option)
+{
+ /* skb is ensured to pullable for all ipv6 payload_len by caller */
+ struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ struct icmp6hdr *icmph = (struct icmp6hdr *)(ip6h + 1);
+ int curr_off = sizeof(*icmph);
+ int ndsize = htons(ip6h->payload_len);
+
+ if (icmph->icmp6_type != NDISC_ROUTER_SOLICITATION)
+ curr_off += sizeof(struct in6_addr);
+
+ while ((curr_off + 2) < ndsize) {
+ u8 *data = (u8 *)icmph + curr_off;
+ u32 opt_len = data[1] << 3;
+
+ if (unlikely(opt_len == 0))
+ return NULL;
+
+ if (data[0] != icmp_option) {
+ curr_off += opt_len;
+ continue;
+ }
+
+ if (unlikely(opt_len < ETH_ALEN + 2))
+ return NULL;
+
+ if (unlikely(curr_off + opt_len > ndsize))
+ return NULL;
+
+ return data + 2;
+ }
+
+ return NULL;
+}
+
+static void ipvlan_snat_patch_tx_ipv6(struct ipvl_dev *ipvlan,
+ struct sk_buff *skb)
+{
+ struct ipv6hdr *ip6h;
+ struct icmp6hdr *icmph;
+ u8 icmp_option;
+ u8 *lladdr;
+ u16 ndsize;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h))))
+ return;
+
+ if (ipv6_hdr(skb)->nexthdr != NEXTHDR_ICMP)
+ return;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h) + sizeof(*icmph))))
+ return;
+
+ ip6h = ipv6_hdr(skb);
+ icmph = (struct icmp6hdr *)(ip6h + 1);
+
+ /* Patch Source-LL for solicitation, Target-LL for advertisement */
+ if (icmph->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
+ icmph->icmp6_type == NDISC_ROUTER_SOLICITATION)
+ icmp_option = ND_OPT_SOURCE_LL_ADDR;
+ else if (icmph->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)
+ icmp_option = ND_OPT_TARGET_LL_ADDR;
+ else
+ return;
+
+ ndsize = htons(ip6h->payload_len);
+ if (unlikely(!pskb_may_pull(skb, sizeof(*ip6h) + ndsize)))
+ return;
+
+ lladdr = ipvlan_search_icmp6_ll_addr(skb, icmp_option);
+ if (!lladdr)
+ return;
+
+ ether_addr_copy(lladdr, ipvlan->phy_dev->dev_addr);
+
+ ip6h = ipv6_hdr(skb);
+ icmph = (struct icmp6hdr *)(ip6h + 1);
+ icmph->icmp6_cksum = 0;
+ icmph->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+ ndsize,
+ IPPROTO_ICMPV6,
+ csum_partial(icmph,
+ ndsize,
+ 0));
+ skb->ip_summed = CHECKSUM_COMPLETE;
+}
+#else
+static void ipvlan_snat_patch_tx_ipv6(struct ipvl_dev *ipvlan,
+ struct sk_buff *skb)
+{
+}
+#endif
+
static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
{
void *lyr3h;
struct ipvl_addr *addr;
- int addr_type;
+ int addr_type = -1;
bool same_mac_addr;
struct ipvl_dev *ipvlan = netdev_priv(dev);
struct ethhdr *eth = skb_eth_hdr(skb);
@@ -825,8 +931,6 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
}
} else {
/* Ok. It is a packet to outside on learnable. Fix source eth-address. */
- struct sk_buff *orig_skb = skb;
-
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb)
return NET_XMIT_DROP;
@@ -835,17 +939,10 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
ether_addr_copy(skb_eth_hdr(skb)->h_source,
ipvlan->phy_dev->dev_addr);
- /* ToDo: Handle ICMPv6 for neighbours discovery.*/
- if (lyr3h && addr_type == IPVL_ARP) {
- struct arphdr *arph;
- /* must reparse new skb */
- if (skb != orig_skb && lyr3h && addr_type == IPVL_ARP)
- lyr3h = ipvlan_get_L3_hdr(ipvlan->port, skb,
- &addr_type);
- arph = (struct arphdr *)lyr3h;
- ether_addr_copy((u8 *)(arph + 1),
- ipvlan->phy_dev->dev_addr);
- }
+ if (addr_type == IPVL_ARP)
+ ipvlan_snat_patch_tx_arp(ipvlan, skb);
+ else if (addr_type == IPVL_ICMPV6 || addr_type == IPVL_IPV6)
+ ipvlan_snat_patch_tx_ipv6(ipvlan, skb);
}
tx_phy_dev:
--
2.25.1
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