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>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index e287346..f98ec44 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2165,6 +2165,35 @@
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 @@
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);