From 49f810f00fa347427fa8cba2197b303234842d25 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Mon, 19 Jun 2017 10:04:00 +0200 Subject: [PATCH] vxlan: allow multiple VXLANs with same VNI for IPv6 link-local addresses As link-local addresses are only valid for a single interface, we can allow to use the same VNI for multiple independent VXLANs, as long as the used interfaces are distinct. This way, VXLANs can always be used as a drop-in replacement for VLANs with greater ID space. This also extends VNI lookup to respect the ifindex when link-local IPv6 addresses are used, so using the same VNI on multiple interfaces can actually work. Signed-off-by: Matthias Schiffer Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 68 ++++++++++++++++++++++++++++++--------------- 1 file changed, 45 insertions(+), 23 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 45a8a5475f3d..653b2bb32be1 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -226,7 +226,8 @@ static struct vxlan_sock *vxlan_find_sock(struct net *net, sa_family_t family, return NULL; } -static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, __be32 vni) +static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, int ifindex, + __be32 vni) { struct vxlan_dev *vxlan; @@ -235,17 +236,27 @@ static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs, __be32 vni) vni = 0; hlist_for_each_entry_rcu(vxlan, vni_head(vs, vni), hlist) { - if (vxlan->default_dst.remote_vni == vni) - return vxlan; + if (vxlan->default_dst.remote_vni != vni) + continue; + + if (IS_ENABLED(CONFIG_IPV6)) { + const struct vxlan_config *cfg = &vxlan->cfg; + + if ((cfg->flags & VXLAN_F_IPV6_LINKLOCAL) && + cfg->remote_ifindex != ifindex) + continue; + } + + return vxlan; } return NULL; } /* Look up VNI in a per net namespace table */ -static struct vxlan_dev *vxlan_find_vni(struct net *net, __be32 vni, - sa_family_t family, __be16 port, - u32 flags) +static struct vxlan_dev *vxlan_find_vni(struct net *net, int ifindex, + __be32 vni, sa_family_t family, + __be16 port, u32 flags) { struct vxlan_sock *vs; @@ -253,7 +264,7 @@ static struct vxlan_dev *vxlan_find_vni(struct net *net, __be32 vni, if (!vs) return NULL; - return vxlan_vs_find_vni(vs, vni); + return vxlan_vs_find_vni(vs, ifindex, vni); } /* Fill in neighbour message in skbuff. */ @@ -1360,7 +1371,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb) vni = vxlan_vni(vxlan_hdr(skb)->vx_vni); - vxlan = vxlan_vs_find_vni(vs, vni); + vxlan = vxlan_vs_find_vni(vs, skb->dev->ifindex, vni); if (!vxlan) goto drop; @@ -2022,8 +2033,10 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan, } static int encap_bypass_if_local(struct sk_buff *skb, struct net_device *dev, - struct vxlan_dev *vxlan, union vxlan_addr *daddr, - __be16 dst_port, __be32 vni, struct dst_entry *dst, + struct vxlan_dev *vxlan, + union vxlan_addr *daddr, + __be16 dst_port, int dst_ifindex, __be32 vni, + struct dst_entry *dst, u32 rt_flags) { #if IS_ENABLED(CONFIG_IPV6) @@ -2039,7 +2052,7 @@ static int encap_bypass_if_local(struct sk_buff *skb, struct net_device *dev, struct vxlan_dev *dst_vxlan; dst_release(dst); - dst_vxlan = vxlan_find_vni(vxlan->net, vni, + dst_vxlan = vxlan_find_vni(vxlan->net, dst_ifindex, vni, daddr->sa.sa_family, dst_port, vxlan->cfg.flags); if (!dst_vxlan) { @@ -2071,6 +2084,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, struct dst_entry *ndst = NULL; __be32 vni, label; __u8 tos, ttl; + int ifindex; int err; u32 flags = vxlan->cfg.flags; bool udp_sum = false; @@ -2091,6 +2105,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, dst_port = rdst->remote_port ? rdst->remote_port : vxlan->cfg.dst_port; vni = (rdst->remote_vni) ? : default_vni; + ifindex = rdst->remote_ifindex; local_ip = vxlan->cfg.saddr; dst_cache = &rdst->dst_cache; md->gbp = skb->mark; @@ -2124,6 +2139,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, dst = &remote_ip; dst_port = info->key.tp_dst ? : vxlan->cfg.dst_port; vni = tunnel_id_to_key32(info->key.tun_id); + ifindex = 0; dst_cache = &info->dst_cache; if (info->options_len) md = ip_tunnel_info_opts(info); @@ -2141,8 +2157,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, struct rtable *rt; __be16 df = 0; - rt = vxlan_get_route(vxlan, dev, sock4, skb, - rdst ? rdst->remote_ifindex : 0, tos, + rt = vxlan_get_route(vxlan, dev, sock4, skb, ifindex, tos, dst->sin.sin_addr.s_addr, &local_ip.sin.sin_addr.s_addr, dst_port, src_port, @@ -2155,8 +2170,8 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, /* Bypass encapsulation if the destination is local */ if (!info) { err = encap_bypass_if_local(skb, dev, vxlan, dst, - dst_port, vni, &rt->dst, - rt->rt_flags); + dst_port, ifindex, vni, + &rt->dst, rt->rt_flags); if (err) goto out_unlock; } else if (info->key.tun_flags & TUNNEL_DONT_FRAGMENT) { @@ -2178,8 +2193,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, } else { struct vxlan_sock *sock6 = rcu_dereference(vxlan->vn6_sock); - ndst = vxlan6_get_route(vxlan, dev, sock6, skb, - rdst ? rdst->remote_ifindex : 0, tos, + ndst = vxlan6_get_route(vxlan, dev, sock6, skb, ifindex, tos, label, &dst->sin6.sin6_addr, &local_ip.sin6.sin6_addr, dst_port, src_port, @@ -2194,8 +2208,8 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, u32 rt6i_flags = ((struct rt6_info *)ndst)->rt6i_flags; err = encap_bypass_if_local(skb, dev, vxlan, dst, - dst_port, vni, ndst, - rt6i_flags); + dst_port, ifindex, vni, + ndst, rt6i_flags); if (err) goto out_unlock; } @@ -2993,11 +3007,19 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf, if (tmp == old) continue; - if (tmp->cfg.vni == conf->vni && - tmp->cfg.dst_port == conf->dst_port && - (tmp->cfg.flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6)) == + if (tmp->cfg.vni != conf->vni) + continue; + if (tmp->cfg.dst_port != conf->dst_port) + continue; + if ((tmp->cfg.flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6)) != (conf->flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6))) - return -EEXIST; + continue; + + if ((conf->flags & VXLAN_F_IPV6_LINKLOCAL) && + tmp->cfg.remote_ifindex != conf->remote_ifindex) + continue; + + return -EEXIST; } return 0; -- 2.30.2