linux/net/bridge/br_arp_nd_proxy.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

470 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Handle bridge arp/nd proxy/suppress
*
* Copyright (C) 2017 Cumulus Networks
* Copyright (c) 2017 Roopa Prabhu <roopa@cumulusnetworks.com>
*
* Authors:
* Roopa Prabhu <roopa@cumulusnetworks.com>
*/
#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 <net/ipv6_stubs.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ip6_checksum.h>
#endif
#include "br_private.h"
void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
{
struct net_bridge_port *p;
bool neigh_suppress = false;
list_for_each_entry(p, &br->port_list, list) {
if (p->flags & BR_NEIGH_SUPPRESS) {
neigh_suppress = true;
break;
}
}
br_opt_toggle(br, BROPT_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 = 0;
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_opt_get(br, BROPT_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 = 1;
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_opt_get(br, BROPT_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 = 1;
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_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))
BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
}
neigh_release(n);
}
}
#endif
#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 *br, 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 net_bridge_vlan_group *vg;
struct sk_buff *reply;
struct nd_msg *na;
struct ipv6hdr *pip6;
int na_olen = 8; /* opt hdr + ETH_ALEN for target */
int ns_olen;
int i, len;
u8 *daddr;
u16 pvid;
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 = (n->flags & NTF_ROUTER) ? 1 : 0;
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)
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(reply, vlan_proto, vlan_tci);
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);
if (p) {
dev_queue_xmit(reply);
} else {
skb_reset_mac_header(reply);
__skb_pull(reply, skb_network_offset(reply));
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 = 0;
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 = 1;
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 = 1;
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 = 1;
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_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))
BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
}
neigh_release(n);
}
}
#endif