aboutsummaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorDavid Stevens <dlstevens@us.ibm.com>2014-03-24 10:39:58 -0400
committerDavid S. Miller <davem@davemloft.net>2014-03-24 15:35:10 -0400
commit4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa (patch)
tree3ee4d0ba0ee4ec64d8c1103dc1b2dc1e5231d3e5 /drivers
parent866b7cdf5f8e440c4921765b7f4e1fe102a7e089 (diff)
downloadlinux-linaro-stable-4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa.tar.gz
vxlan: fix nonfunctional neigh_reduce()
The VXLAN neigh_reduce() code is completely non-functional since check-in. Specific errors: 1) The original code drops all packets with a multicast destination address, even though neighbor solicitations are sent to the solicited-node address, a multicast address. The code after this check was never run. 2) The neighbor table lookup used the IPv6 header destination, which is the solicited node address, rather than the target address from the neighbor solicitation. So neighbor lookups would always fail if it got this far. Also for L3MISSes. 3) The code calls ndisc_send_na(), which does a send on the tunnel device. The context for neigh_reduce() is the transmit path, vxlan_xmit(), where the host or a bridge-attached neighbor is trying to transmit a neighbor solicitation. To respond to it, the tunnel endpoint needs to do a *receive* of the appropriate neighbor advertisement. Doing a send, would only try to send the advertisement, encapsulated, to the remote destinations in the fdb -- hosts that definitely did not do the corresponding solicitation. 4) The code uses the tunnel endpoint IPv6 forwarding flag to determine the isrouter flag in the advertisement. This has nothing to do with whether or not the target is a router, and generally won't be set since the tunnel endpoint is bridging, not routing, traffic. The patch below creates a proxy neighbor advertisement to respond to neighbor solicitions as intended, providing proper IPv6 support for neighbor reduction. Signed-off-by: David L Stevens <dlstevens@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/vxlan.c127
1 files changed, 113 insertions, 14 deletions
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index a7eb3f28db6c..1236812c7be6 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1342,15 +1342,103 @@ out:
}
#if IS_ENABLED(CONFIG_IPV6)
+
+static struct sk_buff *vxlan_na_create(struct sk_buff *request,
+ struct neighbour *n, bool isrouter)
+{
+ struct net_device *dev = request->dev;
+ struct sk_buff *reply;
+ struct nd_msg *ns, *na;
+ struct ipv6hdr *pip6;
+ u8 *daddr;
+ int na_olen = 8; /* opt hdr + ETH_ALEN for target */
+ int ns_olen;
+ int i, len;
+
+ if (dev == NULL)
+ return NULL;
+
+ len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) +
+ sizeof(*na) + na_olen + dev->needed_tailroom;
+ reply = alloc_skb(len, GFP_ATOMIC);
+ if (reply == NULL)
+ return NULL;
+
+ reply->protocol = htons(ETH_P_IPV6);
+ reply->dev = dev;
+ skb_reserve(reply, LL_RESERVED_SPACE(request->dev));
+ skb_push(reply, sizeof(struct ethhdr));
+ skb_set_mac_header(reply, 0);
+
+ ns = (struct nd_msg *)skb_transport_header(request);
+
+ daddr = eth_hdr(request)->h_source;
+ ns_olen = request->len - skb_transport_offset(request) - 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 = isrouter;
+ 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));
+
+ reply->ip_summed = CHECKSUM_UNNECESSARY;
+
+ return reply;
+}
+
static int neigh_reduce(struct net_device *dev, struct sk_buff *skb)
{
struct vxlan_dev *vxlan = netdev_priv(dev);
- struct neighbour *n;
- union vxlan_addr ipa;
+ struct nd_msg *msg;
const struct ipv6hdr *iphdr;
const struct in6_addr *saddr, *daddr;
- struct nd_msg *msg;
- struct inet6_dev *in6_dev = NULL;
+ struct neighbour *n;
+ struct inet6_dev *in6_dev;
in6_dev = __in6_dev_get(dev);
if (!in6_dev)
@@ -1363,19 +1451,20 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb)
saddr = &iphdr->saddr;
daddr = &iphdr->daddr;
- if (ipv6_addr_loopback(daddr) ||
- ipv6_addr_is_multicast(daddr))
- goto out;
-
msg = (struct nd_msg *)skb_transport_header(skb);
if (msg->icmph.icmp6_code != 0 ||
msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION)
goto out;
- n = neigh_lookup(ipv6_stub->nd_tbl, daddr, dev);
+ if (ipv6_addr_loopback(daddr) ||
+ ipv6_addr_is_multicast(&msg->target))
+ goto out;
+
+ n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, dev);
if (n) {
struct vxlan_fdb *f;
+ struct sk_buff *reply;
if (!(n->nud_state & NUD_CONNECTED)) {
neigh_release(n);
@@ -1389,13 +1478,23 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb)
goto out;
}
- ipv6_stub->ndisc_send_na(dev, n, saddr, &msg->target,
- !!in6_dev->cnf.forwarding,
- true, false, false);
+ reply = vxlan_na_create(skb, n,
+ !!(f ? f->flags & NTF_ROUTER : 0));
+
neigh_release(n);
+
+ if (reply == NULL)
+ goto out;
+
+ if (netif_rx_ni(reply) == NET_RX_DROP)
+ dev->stats.rx_dropped++;
+
} else if (vxlan->flags & VXLAN_F_L3MISS) {
- ipa.sin6.sin6_addr = *daddr;
- ipa.sa.sa_family = AF_INET6;
+ union vxlan_addr ipa = {
+ .sin6.sin6_addr = msg->target,
+ .sa.sa_family = AF_INET6,
+ };
+
vxlan_ip_miss(dev, &ipa);
}