[linux.git] / net / bridge / br_arp_nd_proxy.c

/*
 *  Handle bridge arp/nd proxy/suppress
 *
 *  Copyright (C) 2017 Cumulus Networks
 *  Copyright (c) 2017 Roopa Prabhu <[email protected]>
 *
 *  Authors:
 *	Roopa Prabhu <[email protected]>
 *
 *  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_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 = 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_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 = 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_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 = 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_opt_get(br, BROPT_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_opt_get(br, BROPT_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 <[email protected]>
	6	*
	7	* Authors:
	8	* Roopa Prabhu <[email protected]>
	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
c69c2cd4	42	br_opt_toggle(br, BROPT_NEIGH_SUPPRESS_ENABLED, neigh_suppress);
821f1b21	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
c69c2cd4	158	if (br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
057658cb RP	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
c69c2cd4 NA	178	if (br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
c69c2cd4 NA	179	br_is_local_ip(vlandev, tip)) {
057658cb RP	180	/* its our local ip, so don't proxy reply
	181	* and don't forward to neigh suppress ports
	182	*/
	183	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
	184	return;
	185	}
	186
	187	n = neigh_lookup(&arp_tbl, &tip, vlandev);
	188	if (n) {
	189	struct net_bridge_fdb_entry *f;
	190
	191	if (!(n->nud_state & NUD_VALID)) {
	192	neigh_release(n);
	193	return;
	194	}
	195
	196	f = br_fdb_find_rcu(br, n->ha, vid);
	197	if (f) {
	198	bool replied = false;
	199
	200	if ((p && (p->flags & BR_PROXYARP)) \|\|
	201	(f->dst && (f->dst->flags & (BR_PROXYARP_WIFI \|
	202	BR_NEIGH_SUPPRESS)))) {
	203	if (!vid)
	204	br_arp_send(br, p, skb->dev, sip, tip,
	205	sha, n->ha, sha, 0, 0);
	206	else
	207	br_arp_send(br, p, skb->dev, sip, tip,
	208	sha, n->ha, sha,
	209	skb->vlan_proto,
	210	skb_vlan_tag_get(skb));
	211	replied = true;
	212	}
	213
	214	/* If we have replied or as long as we know the
	215	* mac, indicate to arp replied
	216	*/
c69c2cd4 NA	217	if (replied \|\|
c69c2cd4 NA	218	br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))
057658cb RP	219	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
	220	}
	221
	222	neigh_release(n);
	223	}
	224	}
	225	#endif
ed842fae RP	226
	227	#if IS_ENABLED(CONFIG_IPV6)
	228	struct nd_msg br_is_nd_neigh_msg(struct sk_buff skb, struct nd_msg *msg)
	229	{
	230	struct nd_msg *m;
	231
	232	m = skb_header_pointer(skb, skb_network_offset(skb) +
	233	sizeof(struct ipv6hdr), sizeof(*msg), msg);
	234	if (!m)
	235	return NULL;
	236
	237	if (m->icmph.icmp6_code != 0 \|\|
	238	(m->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION &&
	239	m->icmph.icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT))
	240	return NULL;
	241
	242	return m;
	243	}
	244
	245	static void br_nd_send(struct net_bridge br, struct net_bridge_port p,
	246	struct sk_buff request, struct neighbour n,
	247	__be16 vlan_proto, u16 vlan_tci, struct nd_msg *ns)
	248	{
	249	struct net_device *dev = request->dev;
	250	struct net_bridge_vlan_group *vg;
	251	struct sk_buff *reply;
	252	struct nd_msg *na;
	253	struct ipv6hdr *pip6;
	254	int na_olen = 8; /* opt hdr + ETH_ALEN for target */
	255	int ns_olen;
	256	int i, len;
	257	u8 *daddr;
	258	u16 pvid;
	259
	260	if (!dev)
	261	return;
	262
	263	len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) +
	264	sizeof(*na) + na_olen + dev->needed_tailroom;
	265
	266	reply = alloc_skb(len, GFP_ATOMIC);
	267	if (!reply)
	268	return;
	269
	270	reply->protocol = htons(ETH_P_IPV6);
	271	reply->dev = dev;
	272	skb_reserve(reply, LL_RESERVED_SPACE(dev));
	273	skb_push(reply, sizeof(struct ethhdr));
	274	skb_set_mac_header(reply, 0);
	275
	276	daddr = eth_hdr(request)->h_source;
	277
	278	/* Do we need option processing ? */
	279	ns_olen = request->len - (skb_network_offset(request) +
	280	sizeof(struct ipv6hdr)) - sizeof(*ns);
	281	for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) {
	282	if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) {
	283	daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
	284	break;
	285	}
	286	}
	287
	288	/* Ethernet header */
	289	ether_addr_copy(eth_hdr(reply)->h_dest, daddr);
290	ether_addr_copy(eth_hdr(reply)->h_source, n->ha);
291	eth_hdr(reply)->h_proto = htons(ETH_P_IPV6);
292	reply->protocol = htons(ETH_P_IPV6);
293
294	skb_pull(reply, sizeof(struct ethhdr));
295	skb_set_network_header(reply, 0);
296	skb_put(reply, sizeof(struct ipv6hdr));
297
298	/* IPv6 header */
299	pip6 = ipv6_hdr(reply);
300	memset(pip6, 0, sizeof(struct ipv6hdr));
301	pip6->version = 6;
302	pip6->priority = ipv6_hdr(request)->priority;
303	pip6->nexthdr = IPPROTO_ICMPV6;
304	pip6->hop_limit = 255;
305	pip6->daddr = ipv6_hdr(request)->saddr;
306	pip6->saddr = (struct in6_addr )n->primary_key;
307
308	skb_pull(reply, sizeof(struct ipv6hdr));
309	skb_set_transport_header(reply, 0);
310
311	na = (struct nd_msg )skb_put(reply, sizeof(na) + na_olen);
312
313	/* Neighbor Advertisement */
314	memset(na, 0, sizeof(*na) + na_olen);
315	na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
7aca011f	316	na->icmph.icmp6_router = (n->flags & NTF_ROUTER) ? 1 : 0;
ed842fae RP	317	na->icmph.icmp6_override = 1;
	318	na->icmph.icmp6_solicited = 1;
	319	na->target = ns->target;
	320	ether_addr_copy(&na->opt[2], n->ha);
	321	na->opt[0] = ND_OPT_TARGET_LL_ADDR;
	322	na->opt[1] = na_olen >> 3;
	323
	324	na->icmph.icmp6_cksum = csum_ipv6_magic(&pip6->saddr,
	325	&pip6->daddr,
	326	sizeof(*na) + na_olen,
	327	IPPROTO_ICMPV6,
	328	csum_partial(na, sizeof(*na) + na_olen, 0));
	329
	330	pip6->payload_len = htons(sizeof(*na) + na_olen);
	331
	332	skb_push(reply, sizeof(struct ipv6hdr));
	333	skb_push(reply, sizeof(struct ethhdr));
	334
	335	reply->ip_summed = CHECKSUM_UNNECESSARY;
	336
	337	if (p)
	338	vg = nbp_vlan_group_rcu(p);
	339	else
	340	vg = br_vlan_group_rcu(br);
	341	pvid = br_get_pvid(vg);
	342	if (pvid == (vlan_tci & VLAN_VID_MASK))
	343	vlan_tci = 0;
	344
	345	if (vlan_tci)
	346	__vlan_hwaccel_put_tag(reply, vlan_proto, vlan_tci);
	347
	348	netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n",
	349	dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha);
	350
	351	if (p) {
	352	dev_queue_xmit(reply);
	353	} else {
	354	skb_reset_mac_header(reply);
	355	__skb_pull(reply, skb_network_offset(reply));
	356	reply->ip_summed = CHECKSUM_UNNECESSARY;
	357	reply->pkt_type = PACKET_HOST;
	358
	359	netif_rx_ni(reply);
	360	}
	361	}
	362
	363	static int br_chk_addr_ip6(struct net_device dev, void data)
	364	{
	365	struct in6_addr addr = (struct in6_addr )data;
	366
	367	if (ipv6_chk_addr(dev_net(dev), addr, dev, 0))
	368	return 1;
	369
	370	return 0;
	371	}
	372
	373	static bool br_is_local_ip6(struct net_device dev, struct in6_addr addr)
	374
	375	{
	376	if (br_chk_addr_ip6(dev, addr))
	377	return true;
	378
	379	/* check if ip is configured on upper dev */
	380	if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, addr))
381	return true;
382
383	return false;
384	}
385
386	void br_do_suppress_nd(struct sk_buff skb, struct net_bridge br,
387	u16 vid, struct net_bridge_port p, struct nd_msg msg)
388	{
389	struct net_device *dev = br->dev;
390	struct net_device *vlandev = NULL;
391	struct in6_addr saddr, daddr;
392	struct ipv6hdr *iphdr;
393	struct neighbour *n;
394
395	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;
396
397	if (p && (p->flags & BR_NEIGH_SUPPRESS))
398	return;
399
400	if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT &&
401	!msg->icmph.icmp6_solicited) {
402	/* prevent flooding to neigh suppress ports */
403	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
404	return;
405	}
406
407	if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
408	return;
409
410	iphdr = ipv6_hdr(skb);
411	saddr = &iphdr->saddr;
412	daddr = &iphdr->daddr;
413
414	if (ipv6_addr_any(saddr) \|\| !ipv6_addr_cmp(saddr, daddr)) {
415	/* prevent flooding to neigh suppress ports */
416	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
417	return;
418	}
419
420	if (vid != 0) {
421	/* build neigh table lookup on the vlan device */
422	vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto,
423	vid);
424	if (!vlandev)
425	return;
426	} else {
427	vlandev = dev;
428	}
429
430	if (br_is_local_ip6(vlandev, &msg->target)) {
431	/* its our own ip, so don't proxy reply
432	* and don't forward to arp suppress ports
433	*/
434	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
435	return;
436	}
437
438	n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, vlandev);
439	if (n) {
440	struct net_bridge_fdb_entry *f;
441
442	if (!(n->nud_state & NUD_VALID)) {
443	neigh_release(n);
444	return;
445	}
446
447	f = br_fdb_find_rcu(br, n->ha, vid);
448	if (f) {
449	bool replied = false;
450
451	if (f->dst && (f->dst->flags & BR_NEIGH_SUPPRESS)) {
452	if (vid != 0)
453	br_nd_send(br, p, skb, n,
454	skb->vlan_proto,
455	skb_vlan_tag_get(skb), msg);
456	else
457	br_nd_send(br, p, skb, n, 0, 0, msg);
458	replied = true;
459	}
460
461	/* If we have replied or as long as we know the
462	* mac, indicate to NEIGH_SUPPRESS ports that we
463	* have replied
464	*/
c69c2cd4 NA	465	if (replied \|\|
c69c2cd4 NA	466	br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))
ed842fae RP	467	BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;
	468	}
	469	neigh_release(n);
	470	}
	471	}
	472	#endif