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Message-Id: <1507092235-39876-3-git-send-email-roopa@cumulusnetworks.com>
Date: Tue, 3 Oct 2017 21:43:54 -0700
From: Roopa Prabhu <roopa@...ulusnetworks.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, nikolay@...ulusnetworks.com,
stephen@...workplumber.org, bridge@...ts.linux-foundation.org
Subject: [PATCH net-next v3 2/3] bridge: suppress arp pkts on BR_NEIGH_SUPPRESS ports
From: Roopa Prabhu <roopa@...ulusnetworks.com>
This patch avoids flooding and proxies arp packets
for BR_NEIGH_SUPPRESS ports.
Moves existing br_do_proxy_arp to br_do_proxy_suppress_arp
to support both proxy arp and neigh suppress.
Signed-off-by: Roopa Prabhu <roopa@...ulusnetworks.com>
---
net/bridge/br_arp_nd_proxy.c | 186 +++++++++++++++++++++++++++++++++++++++++++
net/bridge/br_device.c | 9 +++
net/bridge/br_input.c | 63 ++-------------
net/bridge/br_private.h | 3 +
4 files changed, 203 insertions(+), 58 deletions(-)
diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index f889ad5..6a31104 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -14,6 +14,13 @@
*/
#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/neighbour.h>
+#include <net/arp.h>
+#include <linux/if_vlan.h>
+#include <linux/inetdevice.h>
+#include <net/addrconf.h>
#include "br_private.h"
void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
@@ -30,3 +37,182 @@ void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
br->neigh_suppress_enabled = neigh_suppress;
}
+
+#if IS_ENABLED(CONFIG_INET)
+static void br_arp_send(struct net_bridge_port *p, int type, int ptype,
+ __be32 dest_ip, struct net_device *dev,
+ __be32 src_ip, const unsigned char *dest_hw,
+ const unsigned char *src_hw,
+ const unsigned char *target_hw,
+ __be16 vlan_proto, u16 vlan_tci)
+{
+ struct sk_buff *skb;
+
+ netdev_dbg(dev, "arp send dev %s dst %pI4 dst_hw %pM src %pI4 src_hw %pM\n",
+ dev->name, &dest_ip, dest_hw, &src_ip, src_hw);
+
+ if (!vlan_tci) {
+ arp_send(type, ptype, dest_ip, dev, src_ip,
+ dest_hw, src_hw, target_hw);
+ return;
+ }
+
+ skb = arp_create(type, ptype, dest_ip, dev, src_ip,
+ dest_hw, src_hw, target_hw);
+ if (!skb)
+ return;
+
+ if (p) {
+ struct net_bridge_vlan_group *vg;
+ u16 pvid;
+
+ vg = nbp_vlan_group_rcu(p);
+ pvid = br_get_pvid(vg);
+ if (pvid == vlan_tci)
+ vlan_tci = 0;
+ }
+
+ if (vlan_tci) {
+ skb = vlan_insert_tag_set_proto(skb, vlan_proto,
+ vlan_tci);
+ if (!skb) {
+ net_err_ratelimited("%s: failed to insert VLAN tag\n",
+ __func__);
+ return;
+ }
+ }
+
+ arp_xmit(skb);
+}
+
+static int br_chk_addr_ip(struct net_device *dev, void *data)
+{
+ __be32 ip = *(__be32 *)data;
+ struct in_device *in_dev;
+ __be32 addr = 0;
+
+ in_dev = __in_dev_get_rcu(dev);
+ if (in_dev)
+ addr = inet_confirm_addr(dev_net(dev), in_dev, 0, ip,
+ RT_SCOPE_HOST);
+
+ if (addr == ip)
+ return 1;
+
+ return 0;
+}
+
+static bool br_is_local_ip(struct net_device *dev, __be32 ip)
+{
+ if (br_chk_addr_ip(dev, &ip))
+ return true;
+
+ /* check if ip is configured on upper dev */
+ if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &ip))
+ return true;
+
+ return false;
+}
+
+void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br,
+ u16 vid, struct net_bridge_port *p)
+{
+ struct net_device *dev = br->dev;
+ struct net_device *vlandev = dev;
+ struct neighbour *n;
+ struct arphdr *parp;
+ u8 *arpptr, *sha;
+ __be32 sip, tip;
+
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
+
+ if ((dev->flags & IFF_NOARP) ||
+ !pskb_may_pull(skb, arp_hdr_len(dev)))
+ return;
+
+ parp = arp_hdr(skb);
+
+ if (parp->ar_pro != htons(ETH_P_IP) ||
+ parp->ar_hln != dev->addr_len ||
+ parp->ar_pln != 4)
+ return;
+
+ arpptr = (u8 *)parp + sizeof(struct arphdr);
+ sha = arpptr;
+ arpptr += dev->addr_len; /* sha */
+ memcpy(&sip, arpptr, sizeof(sip));
+ arpptr += sizeof(sip);
+ arpptr += dev->addr_len; /* tha */
+ memcpy(&tip, arpptr, sizeof(tip));
+
+ if (ipv4_is_loopback(tip) ||
+ ipv4_is_multicast(tip))
+ return;
+
+ if (br->neigh_suppress_enabled) {
+ if (p && (p->flags & BR_NEIGH_SUPPRESS))
+ return;
+ if (ipv4_is_zeronet(sip) || sip == tip) {
+ /* prevent flooding to neigh suppress ports */
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ return;
+ }
+ }
+
+ if (parp->ar_op != htons(ARPOP_REQUEST))
+ return;
+
+ if (vid != 0) {
+ vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
+ vid);
+ if (!vlandev)
+ return;
+ }
+
+ if (br->neigh_suppress_enabled && br_is_local_ip(vlandev, tip)) {
+ /* its our local ip, so don't proxy reply
+ * and don't forward to neigh suppress ports
+ */
+ BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
+ return;
+ }
+
+ n = neigh_lookup(&arp_tbl, &tip, 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 ((p && (p->flags & BR_PROXYARP)) ||
+ (f->dst && ((f->dst->flags & BR_PROXYARP_WIFI) ||
+ (f->dst->flags & BR_NEIGH_SUPPRESS)))) {
+ if (!vid)
+ br_arp_send(p, ARPOP_REPLY, ETH_P_ARP,
+ sip, skb->dev, tip, sha,
+ n->ha, sha, 0, 0);
+ else
+ br_arp_send(p, ARPOP_REPLY, ETH_P_ARP,
+ sip, skb->dev, tip, sha,
+ n->ha, sha, skb->vlan_proto,
+ skb_vlan_tag_get(skb));
+ replied = true;
+ }
+
+ /* If we have replied or as long as we know the
+ * mac, indicate to arp 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 f6b6a92..53d1456 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -39,6 +39,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
const struct nf_br_ops *nf_ops;
const unsigned char *dest;
+ struct ethhdr *eth;
u16 vid = 0;
rcu_read_lock();
@@ -57,11 +58,19 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
BR_INPUT_SKB_CB(skb)->brdev = dev;
skb_reset_mac_header(skb);
+ eth = eth_hdr(skb);
skb_pull(skb, ETH_HLEN);
if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
goto out;
+ if (IS_ENABLED(CONFIG_INET) &&
+ (eth->h_proto == htons(ETH_P_ARP) ||
+ eth->h_proto == htons(ETH_P_RARP)) &&
+ br->neigh_suppress_enabled) {
+ br_do_proxy_suppress_arp(skb, br, vid, NULL);
+ }
+
dest = eth_hdr(skb)->h_dest;
if (is_broadcast_ether_addr(dest)) {
br_flood(br, skb, BR_PKT_BROADCAST, false, true);
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 7cb6137..4b8d2ec 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -71,62 +71,6 @@ static int br_pass_frame_up(struct sk_buff *skb)
br_netif_receive_skb);
}
-static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br,
- u16 vid, struct net_bridge_port *p)
-{
- struct net_device *dev = br->dev;
- struct neighbour *n;
- struct arphdr *parp;
- u8 *arpptr, *sha;
- __be32 sip, tip;
-
- BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
-
- if ((dev->flags & IFF_NOARP) ||
- !pskb_may_pull(skb, arp_hdr_len(dev)))
- return;
-
- parp = arp_hdr(skb);
-
- if (parp->ar_pro != htons(ETH_P_IP) ||
- parp->ar_op != htons(ARPOP_REQUEST) ||
- parp->ar_hln != dev->addr_len ||
- parp->ar_pln != 4)
- return;
-
- arpptr = (u8 *)parp + sizeof(struct arphdr);
- sha = arpptr;
- arpptr += dev->addr_len; /* sha */
- memcpy(&sip, arpptr, sizeof(sip));
- arpptr += sizeof(sip);
- arpptr += dev->addr_len; /* tha */
- memcpy(&tip, arpptr, sizeof(tip));
-
- if (ipv4_is_loopback(tip) ||
- ipv4_is_multicast(tip))
- return;
-
- n = neigh_lookup(&arp_tbl, &tip, dev);
- 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 && ((p->flags & BR_PROXYARP) ||
- (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) {
- arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip,
- sha, n->ha, sha);
- BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
- }
-
- neigh_release(n);
- }
-}
-
/* note: already called with rcu_read_lock */
int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
@@ -171,8 +115,11 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
BR_INPUT_SKB_CB(skb)->brdev = br->dev;
- if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP))
- br_do_proxy_arp(skb, br, vid, p);
+ if (IS_ENABLED(CONFIG_INET) &&
+ (skb->protocol == htons(ETH_P_ARP) ||
+ skb->protocol == htons(ETH_P_RARP))) {
+ br_do_proxy_suppress_arp(skb, br, vid, p);
+ }
switch (pkt_type) {
case BR_PKT_MULTICAST:
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index f47332e..bb095dc 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1139,5 +1139,8 @@ static inline void br_switchdev_frame_unmark(struct sk_buff *skb)
}
#endif /* CONFIG_NET_SWITCHDEV */
+/* br_arp_nd_proxy.c */
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);
#endif
--
2.1.4
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