476 lines
11 KiB
C
476 lines
11 KiB
C
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/*
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* Handle bridge arp/nd proxy/suppress
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*
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* Copyright (C) 2017 Cumulus Networks
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* Copyright (c) 2017 Roopa Prabhu <roopa@cumulusnetworks.com>
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*
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* Authors:
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* Roopa Prabhu <roopa@cumulusnetworks.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/neighbour.h>
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#include <net/arp.h>
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#include <linux/if_vlan.h>
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#include <linux/inetdevice.h>
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#include <net/addrconf.h>
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#if IS_ENABLED(CONFIG_IPV6)
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#include <net/ip6_checksum.h>
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#endif
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#include "br_private.h"
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void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
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{
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struct net_bridge_port *p;
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bool neigh_suppress = false;
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list_for_each_entry(p, &br->port_list, list) {
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if (p->flags & BR_NEIGH_SUPPRESS) {
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neigh_suppress = true;
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break;
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}
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}
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br->neigh_suppress_enabled = neigh_suppress;
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}
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#if IS_ENABLED(CONFIG_INET)
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static void br_arp_send(struct net_bridge *br, struct net_bridge_port *p,
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struct net_device *dev, __be32 dest_ip, __be32 src_ip,
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const unsigned char *dest_hw,
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const unsigned char *src_hw,
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const unsigned char *target_hw,
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__be16 vlan_proto, u16 vlan_tci)
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{
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struct net_bridge_vlan_group *vg;
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struct sk_buff *skb;
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u16 pvid;
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netdev_dbg(dev, "arp send dev %s dst %pI4 dst_hw %pM src %pI4 src_hw %pM\n",
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dev->name, &dest_ip, dest_hw, &src_ip, src_hw);
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if (!vlan_tci) {
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arp_send(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip,
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dest_hw, src_hw, target_hw);
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return;
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}
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skb = arp_create(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip,
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dest_hw, src_hw, target_hw);
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if (!skb)
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return;
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if (p)
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vg = nbp_vlan_group_rcu(p);
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else
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vg = br_vlan_group_rcu(br);
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pvid = br_get_pvid(vg);
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if (pvid == (vlan_tci & VLAN_VID_MASK))
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vlan_tci = 0;
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if (vlan_tci)
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__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
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if (p) {
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arp_xmit(skb);
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} else {
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skb_reset_mac_header(skb);
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__skb_pull(skb, skb_network_offset(skb));
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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skb->pkt_type = PACKET_HOST;
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netif_rx_ni(skb);
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}
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}
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static int br_chk_addr_ip(struct net_device *dev, void *data)
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{
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__be32 ip = *(__be32 *)data;
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struct in_device *in_dev;
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__be32 addr = 0;
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in_dev = __in_dev_get_rcu(dev);
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if (in_dev)
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addr = inet_confirm_addr(dev_net(dev), in_dev, 0, ip,
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RT_SCOPE_HOST);
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if (addr == ip)
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return 1;
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return 0;
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}
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static bool br_is_local_ip(struct net_device *dev, __be32 ip)
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{
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if (br_chk_addr_ip(dev, &ip))
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return true;
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/* check if ip is configured on upper dev */
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if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &ip))
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return true;
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return false;
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}
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void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br,
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u16 vid, struct net_bridge_port *p)
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{
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struct net_device *dev = br->dev;
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struct net_device *vlandev = dev;
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struct neighbour *n;
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struct arphdr *parp;
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u8 *arpptr, *sha;
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__be32 sip, tip;
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BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
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if ((dev->flags & IFF_NOARP) ||
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!pskb_may_pull(skb, arp_hdr_len(dev)))
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return;
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parp = arp_hdr(skb);
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if (parp->ar_pro != htons(ETH_P_IP) ||
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parp->ar_hln != dev->addr_len ||
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parp->ar_pln != 4)
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return;
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arpptr = (u8 *)parp + sizeof(struct arphdr);
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sha = arpptr;
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arpptr += dev->addr_len; /* sha */
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memcpy(&sip, arpptr, sizeof(sip));
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arpptr += sizeof(sip);
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arpptr += dev->addr_len; /* tha */
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memcpy(&tip, arpptr, sizeof(tip));
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if (ipv4_is_loopback(tip) ||
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ipv4_is_multicast(tip))
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return;
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if (br->neigh_suppress_enabled) {
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if (p && (p->flags & BR_NEIGH_SUPPRESS))
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return;
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if (parp->ar_op != htons(ARPOP_RREQUEST) &&
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parp->ar_op != htons(ARPOP_RREPLY) &&
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(ipv4_is_zeronet(sip) || sip == tip)) {
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/* prevent flooding to neigh suppress ports */
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BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
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return;
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}
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}
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if (parp->ar_op != htons(ARPOP_REQUEST))
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return;
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if (vid != 0) {
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vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
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vid);
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if (!vlandev)
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return;
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}
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if (br->neigh_suppress_enabled && br_is_local_ip(vlandev, tip)) {
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/* its our local ip, so don't proxy reply
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* and don't forward to neigh suppress ports
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*/
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BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
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return;
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}
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n = neigh_lookup(&arp_tbl, &tip, vlandev);
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if (n) {
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struct net_bridge_fdb_entry *f;
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if (!(n->nud_state & NUD_VALID)) {
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neigh_release(n);
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return;
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}
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f = br_fdb_find_rcu(br, n->ha, vid);
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if (f) {
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bool replied = false;
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if ((p && (p->flags & BR_PROXYARP)) ||
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(f->dst && (f->dst->flags & (BR_PROXYARP_WIFI |
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BR_NEIGH_SUPPRESS)))) {
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if (!vid)
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br_arp_send(br, p, skb->dev, sip, tip,
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sha, n->ha, sha, 0, 0);
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else
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br_arp_send(br, p, skb->dev, sip, tip,
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sha, n->ha, sha,
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skb->vlan_proto,
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skb_vlan_tag_get(skb));
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replied = true;
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}
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/* If we have replied or as long as we know the
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* mac, indicate to arp replied
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*/
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if (replied || br->neigh_suppress_enabled)
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BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
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}
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neigh_release(n);
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}
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}
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#endif
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#if IS_ENABLED(CONFIG_IPV6)
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struct nd_msg *br_is_nd_neigh_msg(struct sk_buff *skb, struct nd_msg *msg)
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{
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struct nd_msg *m;
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m = skb_header_pointer(skb, skb_network_offset(skb) +
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sizeof(struct ipv6hdr), sizeof(*msg), msg);
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if (!m)
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return NULL;
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if (m->icmph.icmp6_code != 0 ||
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(m->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION &&
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m->icmph.icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT))
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return NULL;
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return m;
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}
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static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p,
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struct sk_buff *request, struct neighbour *n,
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__be16 vlan_proto, u16 vlan_tci, struct nd_msg *ns)
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{
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struct net_device *dev = request->dev;
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struct net_bridge_vlan_group *vg;
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struct sk_buff *reply;
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struct nd_msg *na;
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struct ipv6hdr *pip6;
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int na_olen = 8; /* opt hdr + ETH_ALEN for target */
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int ns_olen;
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int i, len;
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u8 *daddr;
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u16 pvid;
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if (!dev)
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return;
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len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) +
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sizeof(*na) + na_olen + dev->needed_tailroom;
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reply = alloc_skb(len, GFP_ATOMIC);
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if (!reply)
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return;
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reply->protocol = htons(ETH_P_IPV6);
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reply->dev = dev;
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skb_reserve(reply, LL_RESERVED_SPACE(dev));
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skb_push(reply, sizeof(struct ethhdr));
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skb_set_mac_header(reply, 0);
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daddr = eth_hdr(request)->h_source;
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/* Do we need option processing ? */
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ns_olen = request->len - (skb_network_offset(request) +
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sizeof(struct ipv6hdr)) - sizeof(*ns);
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for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) {
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if (!ns->opt[i + 1]) {
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kfree_skb(reply);
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return;
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}
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if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) {
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daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
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break;
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}
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}
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/* Ethernet header */
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ether_addr_copy(eth_hdr(reply)->h_dest, daddr);
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ether_addr_copy(eth_hdr(reply)->h_source, n->ha);
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eth_hdr(reply)->h_proto = htons(ETH_P_IPV6);
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reply->protocol = htons(ETH_P_IPV6);
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skb_pull(reply, sizeof(struct ethhdr));
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skb_set_network_header(reply, 0);
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skb_put(reply, sizeof(struct ipv6hdr));
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/* IPv6 header */
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pip6 = ipv6_hdr(reply);
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memset(pip6, 0, sizeof(struct ipv6hdr));
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pip6->version = 6;
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pip6->priority = ipv6_hdr(request)->priority;
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pip6->nexthdr = IPPROTO_ICMPV6;
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pip6->hop_limit = 255;
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pip6->daddr = ipv6_hdr(request)->saddr;
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pip6->saddr = *(struct in6_addr *)n->primary_key;
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skb_pull(reply, sizeof(struct ipv6hdr));
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skb_set_transport_header(reply, 0);
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na = (struct nd_msg *)skb_put(reply, sizeof(*na) + na_olen);
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/* Neighbor Advertisement */
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memset(na, 0, sizeof(*na) + na_olen);
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na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
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na->icmph.icmp6_router = (n->flags & NTF_ROUTER) ? 1 : 0;
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na->icmph.icmp6_override = 1;
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na->icmph.icmp6_solicited = 1;
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na->target = ns->target;
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ether_addr_copy(&na->opt[2], n->ha);
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na->opt[0] = ND_OPT_TARGET_LL_ADDR;
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na->opt[1] = na_olen >> 3;
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na->icmph.icmp6_cksum = csum_ipv6_magic(&pip6->saddr,
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&pip6->daddr,
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sizeof(*na) + na_olen,
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IPPROTO_ICMPV6,
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csum_partial(na, sizeof(*na) + na_olen, 0));
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pip6->payload_len = htons(sizeof(*na) + na_olen);
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skb_push(reply, sizeof(struct ipv6hdr));
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skb_push(reply, sizeof(struct ethhdr));
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reply->ip_summed = CHECKSUM_UNNECESSARY;
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if (p)
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vg = nbp_vlan_group_rcu(p);
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else
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vg = br_vlan_group_rcu(br);
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pvid = br_get_pvid(vg);
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if (pvid == (vlan_tci & VLAN_VID_MASK))
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vlan_tci = 0;
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if (vlan_tci)
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__vlan_hwaccel_put_tag(reply, vlan_proto, vlan_tci);
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netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n",
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dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha);
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if (p) {
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dev_queue_xmit(reply);
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} else {
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skb_reset_mac_header(reply);
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__skb_pull(reply, skb_network_offset(reply));
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reply->ip_summed = CHECKSUM_UNNECESSARY;
|
||
|
|
reply->pkt_type = PACKET_HOST;
|
||
|
|
|
||
|
|
netif_rx_ni(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 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;
|
||
|
|
|
||
|
|
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(br, p, skb, n,
|
||
|
|
skb->vlan_proto,
|
||
|
|
skb_vlan_tag_get(skb), msg);
|
||
|
|
else
|
||
|
|
br_nd_send(br, 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
|