[Bridge] [PATCH net-next v2 3/3] bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports
Roopa Prabhu
roopa at cumulusnetworks.com
Tue Oct 3 18:21:16 UTC 2017
From: Roopa Prabhu <roopa at cumulusnetworks.com>
This patch avoids flooding and proxies ndisc packets
for BR_NEIGH_SUPPRESS ports.
Signed-off-by: Roopa Prabhu <roopa at cumulusnetworks.com>
---
net/bridge/br_arp_nd_proxy.c | 246 +++++++++++++++++++++++++++++++++++++++++++
net/bridge/br_device.c | 11 ++
net/bridge/br_input.c | 10 ++
net/bridge/br_private.h | 3 +
4 files changed, 270 insertions(+)
diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index 1177547..2ae8ea3 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -214,3 +214,249 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br,
neigh_release(n);
}
}
+
+#if IS_ENABLED(CONFIG_IPV6)
+struct nd_msg *br_is_nd_neigh_msg(struct sk_buff *skb, struct nd_msg *msg)
+{
+ struct nd_msg *m;
+
+ m = skb_header_pointer(skb, skb_network_offset(skb) +
+ sizeof(struct ipv6hdr), sizeof(*msg), msg);
+ if (!m)
+ return NULL;
+
+ if (m->icmph.icmp6_code != 0 ||
+ (m->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION &&
+ m->icmph.icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT))
+ return NULL;
+
+ return m;
+}
+
+static void br_nd_send(struct net_bridge_port *p, struct sk_buff *request,
+ struct neighbour *n, __be16 vlan_proto, u16 vlan_tci,
+ struct nd_msg *ns)
+{
+ struct net_device *dev = request->dev;
+ struct sk_buff *reply;
+ struct nd_msg *na;
+ struct ipv6hdr *pip6;
+ u8 *daddr;
+ int na_olen = 8; /* opt hdr + ETH_ALEN for target */
+ int ns_olen;
+ int i, len;
+
+ if (!dev)
+ return;
+
+ len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) +
+ sizeof(*na) + na_olen + dev->needed_tailroom;
+
+ reply = alloc_skb(len, GFP_ATOMIC);
+ if (!reply)
+ return;
+
+ reply->protocol = htons(ETH_P_IPV6);
+ reply->dev = dev;
+ skb_reserve(reply, LL_RESERVED_SPACE(dev));
+ skb_push(reply, sizeof(struct ethhdr));
+ skb_set_mac_header(reply, 0);
+
+ daddr = eth_hdr(request)->h_source;
+
+ /* Do we need option processing ? */
+ ns_olen = request->len - (skb_network_offset(request) +
+ sizeof(struct ipv6hdr)) - sizeof(*ns);
+ for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) {
+ if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) {
+ daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
+ break;
+ }
+ }
+
+ /* Ethernet header */
+ ether_addr_copy(eth_hdr(reply)->h_dest, daddr);
+ ether_addr_copy(eth_hdr(reply)->h_source, n->ha);
+ eth_hdr(reply)->h_proto = htons(ETH_P_IPV6);
+ reply->protocol = htons(ETH_P_IPV6);
+
+ skb_pull(reply, sizeof(struct ethhdr));
+ skb_set_network_header(reply, 0);
+ skb_put(reply, sizeof(struct ipv6hdr));
+
+ /* IPv6 header */
+ pip6 = ipv6_hdr(reply);
+ memset(pip6, 0, sizeof(struct ipv6hdr));
+ pip6->version = 6;
+ pip6->priority = ipv6_hdr(request)->priority;
+ pip6->nexthdr = IPPROTO_ICMPV6;
+ pip6->hop_limit = 255;
+ pip6->daddr = ipv6_hdr(request)->saddr;
+ pip6->saddr = *(struct in6_addr *)n->primary_key;
+
+ skb_pull(reply, sizeof(struct ipv6hdr));
+ skb_set_transport_header(reply, 0);
+
+ na = (struct nd_msg *)skb_put(reply, sizeof(*na) + na_olen);
+
+ /* Neighbor Advertisement */
+ memset(na, 0, sizeof(*na) + na_olen);
+ na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
+ na->icmph.icmp6_router = 0; /* XXX: should be 1 ? */
+ na->icmph.icmp6_override = 1;
+ na->icmph.icmp6_solicited = 1;
+ na->target = ns->target;
+ ether_addr_copy(&na->opt[2], n->ha);
+ na->opt[0] = ND_OPT_TARGET_LL_ADDR;
+ na->opt[1] = na_olen >> 3;
+
+ na->icmph.icmp6_cksum = csum_ipv6_magic(&pip6->saddr,
+ &pip6->daddr,
+ sizeof(*na) + na_olen,
+ IPPROTO_ICMPV6,
+ csum_partial(na, sizeof(*na) + na_olen, 0));
+
+ pip6->payload_len = htons(sizeof(*na) + na_olen);
+
+ skb_push(reply, sizeof(struct ipv6hdr));
+ skb_push(reply, sizeof(struct ethhdr));
+
+ reply->ip_summed = CHECKSUM_UNNECESSARY;
+
+ if (p) {
+ struct net_bridge_vlan_group *vg;
+ u16 pvid;
+
+ vg = nbp_vlan_group_rcu(p);
+ pvid = br_get_pvid(vg);
+ if (pvid && pvid == vlan_tci)
+ vlan_tci = 0;
+ }
+
+ if (vlan_tci != 0) {
+ reply = vlan_insert_tag_set_proto(reply, vlan_proto, vlan_tci);
+ if (!reply) {
+ net_err_ratelimited("evpn: failed to insert VLAN tag\n");
+ return;
+ }
+ }
+
+ netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n",
+ dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha);
+
+ dev_queue_xmit(reply);
+}
+
+static int br_chk_addr_ip6(struct net_device *dev, void *data)
+{
+ struct in6_addr *addr = (struct in6_addr *)data;
+
+ if (ipv6_chk_addr(dev_net(dev), addr, dev, 0))
+ return 1;
+
+ return 0;
+}
+
+static bool br_is_local_ip6(struct net_device *dev, struct in6_addr *addr)
+
+{
+ if (br_chk_addr_ip6(dev, addr))
+ return true;
+
+ /* check if ip is configured on upper dev */
+ if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, addr))
+ return true;
+
+ return false;
+}
+
+void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br,
+ u16 vid, struct net_bridge_port *p, struct nd_msg *msg)
+{
+ struct net_device *dev = br->dev;
+ struct net_device *vlandev = NULL;
+ struct in6_addr *saddr, *daddr;
+ struct ipv6hdr *iphdr;
+ struct inet6_dev *in6_dev;
+ struct neighbour *n;
+
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
+
+ if (p && (p->flags & BR_NEIGH_SUPPRESS))
+ return;
+
+ if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT &&
+ !msg->icmph.icmp6_solicited) {
+ /* prevent flooding to neigh suppress ports */
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ return;
+ }
+
+ if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
+ return;
+
+ in6_dev = __in6_dev_get(dev);
+ if (!in6_dev)
+ return;
+
+ iphdr = ipv6_hdr(skb);
+ saddr = &iphdr->saddr;
+ daddr = &iphdr->daddr;
+
+ if (ipv6_addr_any(saddr) || !ipv6_addr_cmp(saddr, daddr)) {
+ /* prevent flooding to neigh suppress ports */
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ return;
+ }
+
+ if (vid != 0) {
+ /* build neigh table lookup on the vlan device */
+ vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
+ vid);
+ if (!vlandev)
+ return;
+ } else {
+ vlandev = dev;
+ }
+
+ if (br_is_local_ip6(vlandev, &msg->target)) {
+ /* its our own ip, so don't proxy reply
+ * and don't forward to arp suppress ports
+ */
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ return;
+ }
+
+ n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, vlandev);
+ if (n) {
+ struct net_bridge_fdb_entry *f;
+
+ if (!(n->nud_state & NUD_VALID)) {
+ neigh_release(n);
+ return;
+ }
+
+ f = br_fdb_find_rcu(br, n->ha, vid);
+ if (f) {
+ bool replied = false;
+
+ if (f->dst && (f->dst->flags & BR_NEIGH_SUPPRESS)) {
+ if (vid != 0)
+ br_nd_send(p, skb, n, skb->vlan_proto,
+ skb_vlan_tag_get(skb), msg);
+ else
+ br_nd_send(p, skb, n, 0, 0, msg);
+ replied = true;
+ }
+
+ /* If we have replied or as long as we know the
+ * mac, indicate to NEIGH_SUPPRESS ports that we
+ * have replied
+ */
+ if (replied || br->neigh_suppress_enabled)
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ }
+ neigh_release(n);
+ }
+}
+#endif
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 53d1456..c85345a 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -69,6 +69,17 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
eth->h_proto == htons(ETH_P_RARP)) &&
br->neigh_suppress_enabled) {
br_do_proxy_suppress_arp(skb, br, vid, NULL);
+ } else if (IS_ENABLED(CONFIG_IPV6) &&
+ skb->protocol == htons(ETH_P_IPV6) &&
+ br->neigh_suppress_enabled &&
+ pskb_may_pull(skb, sizeof(struct ipv6hdr) +
+ sizeof(struct nd_msg)) &&
+ ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
+ struct nd_msg *msg, _msg;
+
+ msg = br_is_nd_neigh_msg(skb, &_msg);
+ if (msg)
+ br_do_suppress_nd(skb, br, vid, NULL, msg);
}
dest = eth_hdr(skb)->h_dest;
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 4b8d2ec..013b65f 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -119,6 +119,16 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
(skb->protocol == htons(ETH_P_ARP) ||
skb->protocol == htons(ETH_P_RARP))) {
br_do_proxy_suppress_arp(skb, br, vid, p);
+ } else if (IS_ENABLED(CONFIG_IPV6) && br->neigh_suppress_enabled &&
+ skb->protocol == htons(ETH_P_IPV6) &&
+ pskb_may_pull(skb, sizeof(struct ipv6hdr) +
+ sizeof(struct nd_msg)) &&
+ ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
+ struct nd_msg *msg, _msg;
+
+ msg = br_is_nd_neigh_msg(skb, &_msg);
+ if (msg)
+ br_do_suppress_nd(skb, br, vid, p, msg);
}
switch (pkt_type) {
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index bb095dc..f6936e9 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1143,4 +1143,7 @@ static inline void br_switchdev_frame_unmark(struct sk_buff *skb)
void br_recalculate_neigh_suppress_enabled(struct net_bridge *br);
void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br,
u16 vid, struct net_bridge_port *p);
+void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br,
+ u16 vid, struct net_bridge_port *p, struct nd_msg *msg);
+struct nd_msg *br_is_nd_neigh_msg(struct sk_buff *skb, struct nd_msg *m);
#endif
--
2.1.4
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