[mirror_ubuntu-bionic-kernel.git] / net / bridge / br_arp_nd_proxy.c

/*
 *  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>
 *
 *  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.
 */

#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>
#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->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

#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 = 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
Commit	Line	Data
821f1b21 RP	1	/*
	2	* Handle bridge arp/nd proxy/suppress
	3	*
	4	* Copyright (C) 2017 Cumulus Networks
	5	* Copyright (c) 2017 Roopa Prabhu <roopa@cumulusnetworks.com>
	6	*
	7	* Authors:
	8	* Roopa Prabhu <roopa@cumulusnetworks.com>
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*/
	15
	16	#include <linux/kernel.h>
057658cb RP	17	#include <linux/netdevice.h>
	18	#include <linux/etherdevice.h>
	19	#include <linux/neighbour.h>
	20	#include <net/arp.h>
	21	#include <linux/if_vlan.h>
	22	#include <linux/inetdevice.h>
	23	#include <net/addrconf.h>
ed842fae RP	24	#if IS_ENABLED(CONFIG_IPV6)
	25	#include <net/ip6_checksum.h>
	26	#endif
057658cb	27
821f1b21 RP	28	#include "br_private.h"
	29
	30	void br_recalculate_neigh_suppress_enabled(struct net_bridge *br)
	31	{
	32	struct net_bridge_port *p;
	33	bool neigh_suppress = false;
	34
	35	list_for_each_entry(p, &br->port_list, list) {
	36	if (p->flags & BR_NEIGH_SUPPRESS) {
	37	neigh_suppress = true;
	38	break;
	39	}
	40	}
	41
	42	br->neigh_suppress_enabled = neigh_suppress;
	43	}
057658cb RP	44
	45	#if IS_ENABLED(CONFIG_INET)
	46	static void br_arp_send(struct net_bridge br, struct net_bridge_port p,
	47	struct net_device *dev, __be32 dest_ip, __be32 src_ip,
	48	const unsigned char *dest_hw,
	49	const unsigned char *src_hw,
	50	const unsigned char *target_hw,
	51	__be16 vlan_proto, u16 vlan_tci)
	52	{
	53	struct net_bridge_vlan_group *vg;
	54	struct sk_buff *skb;
	55	u16 pvid;
	56
	57	netdev_dbg(dev, "arp send dev %s dst %pI4 dst_hw %pM src %pI4 src_hw %pM\n",
	58	dev->name, &dest_ip, dest_hw, &src_ip, src_hw);
	59
	60	if (!vlan_tci) {
	61	arp_send(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip,
	62	dest_hw, src_hw, target_hw);
	63	return;
	64	}
	65
	66	skb = arp_create(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip,
	67	dest_hw, src_hw, target_hw);
	68	if (!skb)
	69	return;
	70
	71	if (p)
	72	vg = nbp_vlan_group_rcu(p);
	73	else
	74	vg = br_vlan_group_rcu(br);
	75	pvid = br_get_pvid(vg);
	76	if (pvid == (vlan_tci & VLAN_VID_MASK))
	77	vlan_tci = 0;
	78
	79	if (vlan_tci)
	80	__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
	81
	82	if (p) {
	83	arp_xmit(skb);
	84	} else {
	85	skb_reset_mac_header(skb);
	86	__skb_pull(skb, skb_network_offset(skb));
	87	skb->ip_summed = CHECKSUM_UNNECESSARY;
	88	skb->pkt_type = PACKET_HOST;
	89
	90	netif_rx_ni(skb);
	91	}
	92	}
	93
	94	static int br_chk_addr_ip(struct net_device dev, void data)
	95	{
	96	__be32 ip = (__be32 )data;
	97	struct in_device *in_dev;
	98	__be32 addr = 0;
	99
	100	in_dev = __in_dev_get_rcu(dev);
	101	if (in_dev)
	102	addr = inet_confirm_addr(dev_net(dev), in_dev, 0, ip,
	103	RT_SCOPE_HOST);
	104
	105	if (addr == ip)
	106	return 1;
	107
108	return 0;
109	}
110
111	static bool br_is_local_ip(struct net_device *dev, __be32 ip)
112	{
113	if (br_chk_addr_ip(dev, &ip))
114	return true;
115
116	/* check if ip is configured on upper dev */
117	if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &ip))
118	return true;
119
120	return false;
121	}
122
123	void br_do_proxy_suppress_arp(struct sk_buff skb, struct net_bridge br,
124	u16 vid, struct net_bridge_port *p)
125	{
126	struct net_device *dev = br->dev;
127	struct net_device *vlandev = dev;
128	struct neighbour *n;
129	struct arphdr *parp;
130	u8 arpptr, sha;
131	__be32 sip, tip;
132
133	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
134
135	if ((dev->flags & IFF_NOARP) \|\|
136	!pskb_may_pull(skb, arp_hdr_len(dev)))
137	return;
138
139	parp = arp_hdr(skb);
140
141	if (parp->ar_pro != htons(ETH_P_IP) \|\|
142	parp->ar_hln != dev->addr_len \|\|
143	parp->ar_pln != 4)
144	return;
145
146	arpptr = (u8 *)parp + sizeof(struct arphdr);
147	sha = arpptr;
148	arpptr += dev->addr_len; /* sha */
149	memcpy(&sip, arpptr, sizeof(sip));
150	arpptr += sizeof(sip);
151	arpptr += dev->addr_len; /* tha */
152	memcpy(&tip, arpptr, sizeof(tip));
153
154	if (ipv4_is_loopback(tip) \|\|
155	ipv4_is_multicast(tip))
156	return;
157
158	if (br->neigh_suppress_enabled) {
159	if (p && (p->flags & BR_NEIGH_SUPPRESS))
160	return;
161	if (ipv4_is_zeronet(sip) \|\| sip == tip) {
162	/* prevent flooding to neigh suppress ports */
163	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
164	return;
165	}
166	}
167
168	if (parp->ar_op != htons(ARPOP_REQUEST))
169	return;
170
171	if (vid != 0) {
172	vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
173	vid);
174	if (!vlandev)
175	return;
176	}
177
178	if (br->neigh_suppress_enabled && br_is_local_ip(vlandev, tip)) {
179	/* its our local ip, so don't proxy reply
180	* and don't forward to neigh suppress ports
181	*/
182	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
183	return;
184	}
185
186	n = neigh_lookup(&arp_tbl, &tip, vlandev);
187	if (n) {
188	struct net_bridge_fdb_entry *f;
189
190	if (!(n->nud_state & NUD_VALID)) {
191	neigh_release(n);
192	return;
193	}
194
195	f = br_fdb_find_rcu(br, n->ha, vid);
196	if (f) {
197	bool replied = false;
198
199	if ((p && (p->flags & BR_PROXYARP)) \|\|
200	(f->dst && (f->dst->flags & (BR_PROXYARP_WIFI \|
201	BR_NEIGH_SUPPRESS)))) {
202	if (!vid)
203	br_arp_send(br, p, skb->dev, sip, tip,
204	sha, n->ha, sha, 0, 0);
205	else
206	br_arp_send(br, p, skb->dev, sip, tip,
207	sha, n->ha, sha,
208	skb->vlan_proto,
209	skb_vlan_tag_get(skb));
210	replied = true;
211	}
212
213	/* If we have replied or as long as we know the
214	* mac, indicate to arp replied
215	*/
216	if (replied \|\| br->neigh_suppress_enabled)
217	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
218	}
219
220	neigh_release(n);
221	}
222	}
223	#endif
ed842fae RP	224
	225	#if IS_ENABLED(CONFIG_IPV6)
	226	struct nd_msg br_is_nd_neigh_msg(struct sk_buff skb, struct nd_msg *msg)
	227	{
	228	struct nd_msg *m;
	229
	230	m = skb_header_pointer(skb, skb_network_offset(skb) +
	231	sizeof(struct ipv6hdr), sizeof(*msg), msg);
	232	if (!m)
	233	return NULL;
	234
	235	if (m->icmph.icmp6_code != 0 \|\|
	236	(m->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION &&
	237	m->icmph.icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT))
	238	return NULL;
	239
	240	return m;
	241	}
	242
	243	static void br_nd_send(struct net_bridge br, struct net_bridge_port p,
	244	struct sk_buff request, struct neighbour n,
	245	__be16 vlan_proto, u16 vlan_tci, struct nd_msg *ns)
	246	{
	247	struct net_device *dev = request->dev;
	248	struct net_bridge_vlan_group *vg;
	249	struct sk_buff *reply;
	250	struct nd_msg *na;
	251	struct ipv6hdr *pip6;
	252	int na_olen = 8; /* opt hdr + ETH_ALEN for target */
	253	int ns_olen;
	254	int i, len;
	255	u8 *daddr;
	256	u16 pvid;
	257
	258	if (!dev)
	259	return;
	260
	261	len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) +
	262	sizeof(*na) + na_olen + dev->needed_tailroom;
	263
	264	reply = alloc_skb(len, GFP_ATOMIC);
	265	if (!reply)
	266	return;
	267
	268	reply->protocol = htons(ETH_P_IPV6);
	269	reply->dev = dev;
	270	skb_reserve(reply, LL_RESERVED_SPACE(dev));
	271	skb_push(reply, sizeof(struct ethhdr));
	272	skb_set_mac_header(reply, 0);
	273
	274	daddr = eth_hdr(request)->h_source;
	275
	276	/* Do we need option processing ? */
	277	ns_olen = request->len - (skb_network_offset(request) +
	278	sizeof(struct ipv6hdr)) - sizeof(*ns);
	279	for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) {
	280	if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) {
	281	daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
	282	break;
	283	}
	284	}
	285
	286	/* Ethernet header */
	287	ether_addr_copy(eth_hdr(reply)->h_dest, daddr);
288	ether_addr_copy(eth_hdr(reply)->h_source, n->ha);
289	eth_hdr(reply)->h_proto = htons(ETH_P_IPV6);
290	reply->protocol = htons(ETH_P_IPV6);
291
292	skb_pull(reply, sizeof(struct ethhdr));
293	skb_set_network_header(reply, 0);
294	skb_put(reply, sizeof(struct ipv6hdr));
295
296	/* IPv6 header */
297	pip6 = ipv6_hdr(reply);
298	memset(pip6, 0, sizeof(struct ipv6hdr));
299	pip6->version = 6;
300	pip6->priority = ipv6_hdr(request)->priority;
301	pip6->nexthdr = IPPROTO_ICMPV6;
302	pip6->hop_limit = 255;
303	pip6->daddr = ipv6_hdr(request)->saddr;
304	pip6->saddr = (struct in6_addr )n->primary_key;
305
306	skb_pull(reply, sizeof(struct ipv6hdr));
307	skb_set_transport_header(reply, 0);
308
309	na = (struct nd_msg )skb_put(reply, sizeof(na) + na_olen);
310
311	/* Neighbor Advertisement */
312	memset(na, 0, sizeof(*na) + na_olen);
313	na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
94244148	314	na->icmph.icmp6_router = (n->flags & NTF_ROUTER) ? 1 : 0;
ed842fae RP	315	na->icmph.icmp6_override = 1;
	316	na->icmph.icmp6_solicited = 1;
	317	na->target = ns->target;
	318	ether_addr_copy(&na->opt[2], n->ha);
	319	na->opt[0] = ND_OPT_TARGET_LL_ADDR;
	320	na->opt[1] = na_olen >> 3;
	321
	322	na->icmph.icmp6_cksum = csum_ipv6_magic(&pip6->saddr,
	323	&pip6->daddr,
	324	sizeof(*na) + na_olen,
	325	IPPROTO_ICMPV6,
	326	csum_partial(na, sizeof(*na) + na_olen, 0));
	327
	328	pip6->payload_len = htons(sizeof(*na) + na_olen);
	329
	330	skb_push(reply, sizeof(struct ipv6hdr));
	331	skb_push(reply, sizeof(struct ethhdr));
	332
	333	reply->ip_summed = CHECKSUM_UNNECESSARY;
	334
	335	if (p)
	336	vg = nbp_vlan_group_rcu(p);
	337	else
	338	vg = br_vlan_group_rcu(br);
	339	pvid = br_get_pvid(vg);
	340	if (pvid == (vlan_tci & VLAN_VID_MASK))
	341	vlan_tci = 0;
	342
	343	if (vlan_tci)
	344	__vlan_hwaccel_put_tag(reply, vlan_proto, vlan_tci);
	345
	346	netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n",
	347	dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha);
	348
	349	if (p) {
	350	dev_queue_xmit(reply);
	351	} else {
	352	skb_reset_mac_header(reply);
	353	__skb_pull(reply, skb_network_offset(reply));
	354	reply->ip_summed = CHECKSUM_UNNECESSARY;
	355	reply->pkt_type = PACKET_HOST;
	356
	357	netif_rx_ni(reply);
	358	}
	359	}
	360
	361	static int br_chk_addr_ip6(struct net_device dev, void data)
	362	{
	363	struct in6_addr addr = (struct in6_addr )data;
	364
	365	if (ipv6_chk_addr(dev_net(dev), addr, dev, 0))
	366	return 1;
	367
	368	return 0;
	369	}
	370
	371	static bool br_is_local_ip6(struct net_device dev, struct in6_addr addr)
	372
	373	{
	374	if (br_chk_addr_ip6(dev, addr))
	375	return true;
	376
	377	/* check if ip is configured on upper dev */
	378	if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, addr))
379	return true;
380
381	return false;
382	}
383
384	void br_do_suppress_nd(struct sk_buff skb, struct net_bridge br,
385	u16 vid, struct net_bridge_port p, struct nd_msg msg)
386	{
387	struct net_device *dev = br->dev;
388	struct net_device *vlandev = NULL;
389	struct in6_addr saddr, daddr;
390	struct ipv6hdr *iphdr;
391	struct neighbour *n;
392
393	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
394
395	if (p && (p->flags & BR_NEIGH_SUPPRESS))
396	return;
397
398	if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT &&
399	!msg->icmph.icmp6_solicited) {
400	/* prevent flooding to neigh suppress ports */
401	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
402	return;
403	}
404
405	if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
406	return;
407
408	iphdr = ipv6_hdr(skb);
409	saddr = &iphdr->saddr;
410	daddr = &iphdr->daddr;
411
412	if (ipv6_addr_any(saddr) \|\| !ipv6_addr_cmp(saddr, daddr)) {
413	/* prevent flooding to neigh suppress ports */
414	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
415	return;
416	}
417
418	if (vid != 0) {
419	/* build neigh table lookup on the vlan device */
420	vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
421	vid);
422	if (!vlandev)
423	return;
424	} else {
425	vlandev = dev;
426	}
427
428	if (br_is_local_ip6(vlandev, &msg->target)) {
429	/* its our own ip, so don't proxy reply
430	* and don't forward to arp suppress ports
431	*/
432	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
433	return;
434	}
435
436	n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, vlandev);
437	if (n) {
438	struct net_bridge_fdb_entry *f;
439
440	if (!(n->nud_state & NUD_VALID)) {
441	neigh_release(n);
442	return;
443	}
444
445	f = br_fdb_find_rcu(br, n->ha, vid);
446	if (f) {
447	bool replied = false;
448
449	if (f->dst && (f->dst->flags & BR_NEIGH_SUPPRESS)) {
450	if (vid != 0)
451	br_nd_send(br, p, skb, n,
452	skb->vlan_proto,
453	skb_vlan_tag_get(skb), msg);
454	else
455	br_nd_send(br, p, skb, n, 0, 0, msg);
456	replied = true;
457	}
458
459	/* If we have replied or as long as we know the
460	* mac, indicate to NEIGH_SUPPRESS ports that we
461	* have replied
462	*/
463	if (replied \|\| br->neigh_suppress_enabled)
464	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
465	}
466	neigh_release(n);
467	}
468	}
469	#endif