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Commit 84920c14 authored by Tony Zelenoff's avatar Tony Zelenoff Committed by David S. Miller
Browse files

net: Allow ipv6 proxies and arp proxies be shown with iproute2 



Add ability to return neighbour proxies list to caller if
it sent full ndmsg structure and has NTF_PROXY flag set.

Before this patch (and before iproute2 patches):
$ ip neigh add proxy 2001::1 dev eth0
$ ip -6 neigh show
$

After it and with applied iproute2 patches:
$ ip neigh add proxy 2001::1 dev eth0
$ ip -6 neigh show
2001::1 dev eth0  proxy
$

Compatibility with old versions of iproute2 is not broken,
kernel checks for incoming structure size and properly
works if old structure is came.

[v2]
* changed comments style.
* removed useless line with continue and curly bracket.
* changed incoming message size check from equal to more or
  equal.

CC: davem@davemloft.net
CC: kuznet@ms2.inr.ac.ru
CC: netdev@vger.kernel.org
CC: xemul@parallels.com
Signed-off-by: default avatarTony Zelenoff <antonz@parallels.com>
Acked-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5e6bbedd

net/core/neighbour.c

+87 −3
Original line number Diff line number Diff line
@@ -2165,6 +2165,35 @@ static int neigh_fill_info(struct sk_buff *skb, struct neighbour *neigh, 
	return -EMSGSIZE;

}



static int pneigh_fill_info(struct sk_buff *skb, struct pneigh_entry *pn,

			    u32 pid, u32 seq, int type, unsigned int flags,

			    struct neigh_table *tbl)

{

	struct nlmsghdr *nlh;

	struct ndmsg *ndm;



	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);

	if (nlh == NULL)

		return -EMSGSIZE;



	ndm = nlmsg_data(nlh);

	ndm->ndm_family	 = tbl->family;

	ndm->ndm_pad1    = 0;

	ndm->ndm_pad2    = 0;

	ndm->ndm_flags	 = pn->flags | NTF_PROXY;

	ndm->ndm_type	 = NDA_DST;

	ndm->ndm_ifindex = pn->dev->ifindex;

	ndm->ndm_state	 = NUD_NONE;



	NLA_PUT(skb, NDA_DST, tbl->key_len, pn->key);



	return nlmsg_end(skb, nlh);



nla_put_failure:

	nlmsg_cancel(skb, nlh);

	return -EMSGSIZE;

}



static void neigh_update_notify(struct neighbour *neigh)

{

	call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, neigh);
@@ -2214,23 +2243,78 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, 
	return rc;

}



static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb,

			     struct netlink_callback *cb)

{

	struct pneigh_entry *n;

	struct net *net = sock_net(skb->sk);

	int rc, h, s_h = cb->args[3];

	int idx, s_idx = idx = cb->args[4];



	read_lock_bh(&tbl->lock);



	for (h = 0; h <= PNEIGH_HASHMASK; h++) {

		if (h < s_h)

			continue;

		if (h > s_h)

			s_idx = 0;

		for (n = tbl->phash_buckets[h], idx = 0; n; n = n->next) {

			if (dev_net(n->dev) != net)

				continue;

			if (idx < s_idx)

				goto next;

			if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).pid,

					    cb->nlh->nlmsg_seq,

					    RTM_NEWNEIGH,

					    NLM_F_MULTI, tbl) <= 0) {

				read_unlock_bh(&tbl->lock);

				rc = -1;

				goto out;

			}

		next:

			idx++;

		}

	}



	read_unlock_bh(&tbl->lock);

	rc = skb->len;

out:

	cb->args[3] = h;

	cb->args[4] = idx;

	return rc;



}



static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct neigh_table *tbl;

	int t, family, s_t;

	int proxy = 0;

	int err = 0;



	read_lock(&neigh_tbl_lock);

	family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family;



	/* check for full ndmsg structure presence, family member is

	 * the same for both structures

	 */

	if (nlmsg_len(cb->nlh) >= sizeof(struct ndmsg) &&

	    ((struct ndmsg *) nlmsg_data(cb->nlh))->ndm_flags == NTF_PROXY)

		proxy = 1;



	s_t = cb->args[0];



	for (tbl = neigh_tables, t = 0; tbl; tbl = tbl->next, t++) {

	for (tbl = neigh_tables, t = 0; tbl && (err >= 0);

	     tbl = tbl->next, t++) {

		if (t < s_t || (family && tbl->family != family))

			continue;

		if (t > s_t)

			memset(&cb->args[1], 0, sizeof(cb->args) -

						sizeof(cb->args[0]));

		if (neigh_dump_table(tbl, skb, cb) < 0)

			break;

		if (proxy)

			err = pneigh_dump_table(tbl, skb, cb);

		else

			err = neigh_dump_table(tbl, skb, cb);

	}

	read_unlock(&neigh_tbl_lock);