[mirror_ubuntu-focal-kernel.git] / net / bridge / br_arp_nd_proxy.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
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
821f1b21 RP	2	/*
	3	* Handle bridge arp/nd proxy/suppress
	4	*
	5	* Copyright (C) 2017 Cumulus Networks
	6	* Copyright (c) 2017 Roopa Prabhu <roopa@cumulusnetworks.com>
	7	*
	8	* Authors:
	9	* Roopa Prabhu <roopa@cumulusnetworks.com>
821f1b21 RP	10	*/
	11
	12	#include <linux/kernel.h>
057658cb RP	13	#include <linux/netdevice.h>
	14	#include <linux/etherdevice.h>
	15	#include <linux/neighbour.h>
	16	#include <net/arp.h>
	17	#include <linux/if_vlan.h>
	18	#include <linux/inetdevice.h>
	19	#include <net/addrconf.h>
3616d08b	20	#include <net/ipv6_stubs.h>
ed842fae RP	21	#if IS_ENABLED(CONFIG_IPV6)
	22	#include <net/ip6_checksum.h>
	23	#endif
057658cb	24
821f1b21 RP	25	#include "br_private.h"
	26
	27	void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
	28	{
	29	struct net_bridge_port *p;
	30	bool neigh_suppress = false;
	31
	32	list_for_each_entry(p, &br->port_list, list) {
	33	if (p->flags & BR_NEIGH_SUPPRESS) {
	34	neigh_suppress = true;
	35	break;
	36	}
	37	}
	38
c69c2cd4	39	br_opt_toggle(br, BROPT_NEIGH_SUPPRESS_ENABLED, neigh_suppress);
821f1b21	40	}
057658cb RP	41
	42	#if IS_ENABLED(CONFIG_INET)
	43	static void br_arp_send(struct net_bridge br, struct net_bridge_port p,
	44	struct net_device *dev, __be32 dest_ip, __be32 src_ip,
	45	const unsigned char *dest_hw,
	46	const unsigned char *src_hw,
	47	const unsigned char *target_hw,
	48	__be16 vlan_proto, u16 vlan_tci)
	49	{
	50	struct net_bridge_vlan_group *vg;
	51	struct sk_buff *skb;
	52	u16 pvid;
	53
	54	netdev_dbg(dev, "arp send dev %s dst %pI4 dst_hw %pM src %pI4 src_hw %pM\n",
	55	dev->name, &dest_ip, dest_hw, &src_ip, src_hw);
	56
	57	if (!vlan_tci) {
	58	arp_send(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip,
	59	dest_hw, src_hw, target_hw);
	60	return;
	61	}
	62
	63	skb = arp_create(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip,
	64	dest_hw, src_hw, target_hw);
	65	if (!skb)
	66	return;
	67
	68	if (p)
	69	vg = nbp_vlan_group_rcu(p);
	70	else
	71	vg = br_vlan_group_rcu(br);
	72	pvid = br_get_pvid(vg);
	73	if (pvid == (vlan_tci & VLAN_VID_MASK))
	74	vlan_tci = 0;
	75
	76	if (vlan_tci)
	77	__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
	78
	79	if (p) {
	80	arp_xmit(skb);
	81	} else {
	82	skb_reset_mac_header(skb);
	83	__skb_pull(skb, skb_network_offset(skb));
	84	skb->ip_summed = CHECKSUM_UNNECESSARY;
	85	skb->pkt_type = PACKET_HOST;
	86
	87	netif_rx_ni(skb);
	88	}
	89	}
	90
	91	static int br_chk_addr_ip(struct net_device dev, void data)
	92	{
	93	__be32 ip = (__be32 )data;
	94	struct in_device *in_dev;
	95	__be32 addr = 0;
	96
	97	in_dev = __in_dev_get_rcu(dev);
	98	if (in_dev)
	99	addr = inet_confirm_addr(dev_net(dev), in_dev, 0, ip,
	100	RT_SCOPE_HOST);
	101
	102	if (addr == ip)
	103	return 1;
	104
105	return 0;
106	}
107
108	static bool br_is_local_ip(struct net_device *dev, __be32 ip)
109	{
110	if (br_chk_addr_ip(dev, &ip))
111	return true;
112
113	/* check if ip is configured on upper dev */
114	if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &ip))
115	return true;
116
117	return false;
118	}
119
120	void br_do_proxy_suppress_arp(struct sk_buff skb, struct net_bridge br,
121	u16 vid, struct net_bridge_port *p)
122	{
123	struct net_device *dev = br->dev;
124	struct net_device *vlandev = dev;
125	struct neighbour *n;
126	struct arphdr *parp;
127	u8 arpptr, sha;
128	__be32 sip, tip;
129
f12064d1	130	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 0;
057658cb RP	131
	132	if ((dev->flags & IFF_NOARP) \|\|
	133	!pskb_may_pull(skb, arp_hdr_len(dev)))
	134	return;
	135
	136	parp = arp_hdr(skb);
	137
	138	if (parp->ar_pro != htons(ETH_P_IP) \|\|
	139	parp->ar_hln != dev->addr_len \|\|
	140	parp->ar_pln != 4)
	141	return;
	142
	143	arpptr = (u8 *)parp + sizeof(struct arphdr);
	144	sha = arpptr;
	145	arpptr += dev->addr_len; /* sha */
	146	memcpy(&sip, arpptr, sizeof(sip));
	147	arpptr += sizeof(sip);
	148	arpptr += dev->addr_len; /* tha */
	149	memcpy(&tip, arpptr, sizeof(tip));
	150
	151	if (ipv4_is_loopback(tip) \|\|
	152	ipv4_is_multicast(tip))
	153	return;
	154
c69c2cd4	155	if (br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
057658cb RP	156	if (p && (p->flags & BR_NEIGH_SUPPRESS))
	157	return;
	158	if (ipv4_is_zeronet(sip) \|\| sip == tip) {
	159	/* prevent flooding to neigh suppress ports */
f12064d1	160	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
057658cb RP	161	return;
	162	}
	163	}
	164
	165	if (parp->ar_op != htons(ARPOP_REQUEST))
	166	return;
	167
	168	if (vid != 0) {
	169	vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
	170	vid);
	171	if (!vlandev)
	172	return;
	173	}
	174
c69c2cd4 NA	175	if (br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
c69c2cd4 NA	176	br_is_local_ip(vlandev, tip)) {
057658cb RP	177	/* its our local ip, so don't proxy reply
	178	* and don't forward to neigh suppress ports
	179	*/
f12064d1	180	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
057658cb RP	181	return;
	182	}
	183
	184	n = neigh_lookup(&arp_tbl, &tip, vlandev);
	185	if (n) {
	186	struct net_bridge_fdb_entry *f;
	187
	188	if (!(n->nud_state & NUD_VALID)) {
	189	neigh_release(n);
	190	return;
	191	}
	192
	193	f = br_fdb_find_rcu(br, n->ha, vid);
	194	if (f) {
	195	bool replied = false;
	196
	197	if ((p && (p->flags & BR_PROXYARP)) \|\|
	198	(f->dst && (f->dst->flags & (BR_PROXYARP_WIFI \|
	199	BR_NEIGH_SUPPRESS)))) {
	200	if (!vid)
	201	br_arp_send(br, p, skb->dev, sip, tip,
	202	sha, n->ha, sha, 0, 0);
	203	else
	204	br_arp_send(br, p, skb->dev, sip, tip,
	205	sha, n->ha, sha,
	206	skb->vlan_proto,
	207	skb_vlan_tag_get(skb));
	208	replied = true;
	209	}
	210
	211	/* If we have replied or as long as we know the
	212	* mac, indicate to arp replied
	213	*/
c69c2cd4 NA	214	if (replied \|\|
c69c2cd4 NA	215	br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))
f12064d1	216	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
057658cb RP	217	}
	218
	219	neigh_release(n);
	220	}
	221	}
	222	#endif
ed842fae RP	223
	224	#if IS_ENABLED(CONFIG_IPV6)
	225	struct nd_msg br_is_nd_neigh_msg(struct sk_buff skb, struct nd_msg *msg)
	226	{
	227	struct nd_msg *m;
	228
	229	m = skb_header_pointer(skb, skb_network_offset(skb) +
	230	sizeof(struct ipv6hdr), sizeof(*msg), msg);
	231	if (!m)
	232	return NULL;
	233
	234	if (m->icmph.icmp6_code != 0 \|\|
	235	(m->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION &&
	236	m->icmph.icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT))
	237	return NULL;
	238
	239	return m;
	240	}
	241
	242	static void br_nd_send(struct net_bridge br, struct net_bridge_port p,
	243	struct sk_buff request, struct neighbour n,
	244	__be16 vlan_proto, u16 vlan_tci, struct nd_msg *ns)
	245	{
	246	struct net_device *dev = request->dev;
	247	struct net_bridge_vlan_group *vg;
	248	struct sk_buff *reply;
	249	struct nd_msg *na;
	250	struct ipv6hdr *pip6;
	251	int na_olen = 8; /* opt hdr + ETH_ALEN for target */
	252	int ns_olen;
	253	int i, len;
	254	u8 *daddr;
	255	u16 pvid;
	256
	257	if (!dev)
	258	return;
	259
	260	len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) +
	261	sizeof(*na) + na_olen + dev->needed_tailroom;
	262
	263	reply = alloc_skb(len, GFP_ATOMIC);
	264	if (!reply)
	265	return;
	266
	267	reply->protocol = htons(ETH_P_IPV6);
	268	reply->dev = dev;
	269	skb_reserve(reply, LL_RESERVED_SPACE(dev));
	270	skb_push(reply, sizeof(struct ethhdr));
	271	skb_set_mac_header(reply, 0);
	272
	273	daddr = eth_hdr(request)->h_source;
	274
	275	/* Do we need option processing ? */
	276	ns_olen = request->len - (skb_network_offset(request) +
	277	sizeof(struct ipv6hdr)) - sizeof(*ns);
	278	for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) {
	279	if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) {
	280	daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
	281	break;
	282	}
	283	}
	284
	285	/* Ethernet header */
	286	ether_addr_copy(eth_hdr(reply)->h_dest, daddr);
287	ether_addr_copy(eth_hdr(reply)->h_source, n->ha);
288	eth_hdr(reply)->h_proto = htons(ETH_P_IPV6);
289	reply->protocol = htons(ETH_P_IPV6);
290
291	skb_pull(reply, sizeof(struct ethhdr));
292	skb_set_network_header(reply, 0);
293	skb_put(reply, sizeof(struct ipv6hdr));
294
295	/* IPv6 header */
296	pip6 = ipv6_hdr(reply);
297	memset(pip6, 0, sizeof(struct ipv6hdr));
298	pip6->version = 6;
299	pip6->priority = ipv6_hdr(request)->priority;
300	pip6->nexthdr = IPPROTO_ICMPV6;
301	pip6->hop_limit = 255;
302	pip6->daddr = ipv6_hdr(request)->saddr;
303	pip6->saddr = (struct in6_addr )n->primary_key;
304
305	skb_pull(reply, sizeof(struct ipv6hdr));
306	skb_set_transport_header(reply, 0);
307
308	na = (struct nd_msg )skb_put(reply, sizeof(na) + na_olen);
309
310	/* Neighbor Advertisement */
311	memset(na, 0, sizeof(*na) + na_olen);
312	na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
7aca011f	313	na->icmph.icmp6_router = (n->flags & NTF_ROUTER) ? 1 : 0;
ed842fae RP	314	na->icmph.icmp6_override = 1;
	315	na->icmph.icmp6_solicited = 1;
	316	na->target = ns->target;
	317	ether_addr_copy(&na->opt[2], n->ha);
	318	na->opt[0] = ND_OPT_TARGET_LL_ADDR;
	319	na->opt[1] = na_olen >> 3;
	320
	321	na->icmph.icmp6_cksum = csum_ipv6_magic(&pip6->saddr,
	322	&pip6->daddr,
	323	sizeof(*na) + na_olen,
	324	IPPROTO_ICMPV6,
	325	csum_partial(na, sizeof(*na) + na_olen, 0));
	326
	327	pip6->payload_len = htons(sizeof(*na) + na_olen);
	328
	329	skb_push(reply, sizeof(struct ipv6hdr));
	330	skb_push(reply, sizeof(struct ethhdr));
	331
	332	reply->ip_summed = CHECKSUM_UNNECESSARY;
	333
	334	if (p)
	335	vg = nbp_vlan_group_rcu(p);
	336	else
	337	vg = br_vlan_group_rcu(br);
	338	pvid = br_get_pvid(vg);
	339	if (pvid == (vlan_tci & VLAN_VID_MASK))
	340	vlan_tci = 0;
	341
	342	if (vlan_tci)
	343	__vlan_hwaccel_put_tag(reply, vlan_proto, vlan_tci);
	344
	345	netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n",
	346	dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha);
	347
	348	if (p) {
	349	dev_queue_xmit(reply);
	350	} else {
	351	skb_reset_mac_header(reply);
	352	__skb_pull(reply, skb_network_offset(reply));
	353	reply->ip_summed = CHECKSUM_UNNECESSARY;
	354	reply->pkt_type = PACKET_HOST;
	355
	356	netif_rx_ni(reply);
	357	}
	358	}
	359
	360	static int br_chk_addr_ip6(struct net_device dev, void data)
	361	{
	362	struct in6_addr addr = (struct in6_addr )data;
	363
	364	if (ipv6_chk_addr(dev_net(dev), addr, dev, 0))
	365	return 1;
	366
	367	return 0;
	368	}
	369
	370	static bool br_is_local_ip6(struct net_device dev, struct in6_addr addr)
	371
	372	{
	373	if (br_chk_addr_ip6(dev, addr))
	374	return true;
	375
	376	/* check if ip is configured on upper dev */
	377	if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, addr))
378	return true;
379
380	return false;
381	}
382
383	void br_do_suppress_nd(struct sk_buff skb, struct net_bridge br,
384	u16 vid, struct net_bridge_port p, struct nd_msg msg)
385	{
386	struct net_device *dev = br->dev;
387	struct net_device *vlandev = NULL;
388	struct in6_addr saddr, daddr;
389	struct ipv6hdr *iphdr;
390	struct neighbour *n;
391
f12064d1	392	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 0;
ed842fae RP	393
	394	if (p && (p->flags & BR_NEIGH_SUPPRESS))
	395	return;
	396
	397	if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT &&
	398	!msg->icmph.icmp6_solicited) {
	399	/* prevent flooding to neigh suppress ports */
f12064d1	400	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
ed842fae RP	401	return;
	402	}
	403
	404	if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
	405	return;
	406
	407	iphdr = ipv6_hdr(skb);
	408	saddr = &iphdr->saddr;
	409	daddr = &iphdr->daddr;
	410
	411	if (ipv6_addr_any(saddr) \|\| !ipv6_addr_cmp(saddr, daddr)) {
	412	/* prevent flooding to neigh suppress ports */
f12064d1	413	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
ed842fae RP	414	return;
	415	}
	416
	417	if (vid != 0) {
	418	/* build neigh table lookup on the vlan device */
	419	vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
	420	vid);
	421	if (!vlandev)
	422	return;
	423	} else {
	424	vlandev = dev;
	425	}
	426
	427	if (br_is_local_ip6(vlandev, &msg->target)) {
	428	/* its our own ip, so don't proxy reply
	429	* and don't forward to arp suppress ports
	430	*/
f12064d1	431	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
ed842fae RP	432	return;
	433	}
	434
	435	n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, vlandev);
	436	if (n) {
	437	struct net_bridge_fdb_entry *f;
	438
	439	if (!(n->nud_state & NUD_VALID)) {
	440	neigh_release(n);
	441	return;
	442	}
	443
	444	f = br_fdb_find_rcu(br, n->ha, vid);
	445	if (f) {
	446	bool replied = false;
	447
	448	if (f->dst && (f->dst->flags & BR_NEIGH_SUPPRESS)) {
	449	if (vid != 0)
	450	br_nd_send(br, p, skb, n,
	451	skb->vlan_proto,
	452	skb_vlan_tag_get(skb), msg);
	453	else
	454	br_nd_send(br, p, skb, n, 0, 0, msg);
	455	replied = true;
	456	}
	457
	458	/* If we have replied or as long as we know the
	459	* mac, indicate to NEIGH_SUPPRESS ports that we
	460	* have replied
	461	*/
c69c2cd4 NA	462	if (replied \|\|
c69c2cd4 NA	463	br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))
f12064d1	464	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;
ed842fae RP	465	}
	466	neigh_release(n);
	467	}
	468	}
	469	#endif