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: Tony Zelenoff <antonz@parallels.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tony Zelenoff 2012-01-26 22:28:58 +00:00 committed by David S. Miller
parent 5e6bbedd82
commit 84920c1420

View File

@ -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);