diff options
Diffstat (limited to 'net/bridge/br_arp_nd_proxy.c')
| -rw-r--r-- | net/bridge/br_arp_nd_proxy.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c index f889ad5f0048..a79c1824e163 100644 --- a/net/bridge/br_arp_nd_proxy.c +++ b/net/bridge/br_arp_nd_proxy.c @@ -14,6 +14,14 @@ */ #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 +38,183 @@ 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 *br, struct net_bridge_port *p, + struct net_device *dev, __be32 dest_ip, __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 net_bridge_vlan_group *vg; + struct sk_buff *skb; + u16 pvid; + + 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(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip, + dest_hw, src_hw, target_hw); + return; + } + + skb = arp_create(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip, + dest_hw, src_hw, target_hw); + if (!skb) + return; + + if (p) + vg = nbp_vlan_group_rcu(p); + else + vg = br_vlan_group_rcu(br); + pvid = br_get_pvid(vg); + if (pvid == (vlan_tci & VLAN_VID_MASK)) + vlan_tci = 0; + + if (vlan_tci) + __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); + + if (p) { + arp_xmit(skb); + } else { + skb_reset_mac_header(skb); + __skb_pull(skb, skb_network_offset(skb)); + skb->ip_summed = CHECKSUM_UNNECESSARY; + skb->pkt_type = PACKET_HOST; + + netif_rx_ni(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 | + BR_NEIGH_SUPPRESS)))) { + if (!vid) + br_arp_send(br, p, skb->dev, sip, tip, + sha, n->ha, sha, 0, 0); + else + br_arp_send(br, p, skb->dev, sip, 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 |