On 6/9/17 8:22 AM, Donald Sharp wrote:
> @@ -988,7 +988,16 @@ static void ipmr_cache_resolve(struct net *net, struct
> mr_table *mrt,
>
> rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
> } else {
> - ip_mr_forward(net, mrt, skb, c, 0);
> + struct net_device *dev = skb->dev;
> +
> + if (netif_is_l3_master(dev)) {
> + dev = __dev_get_by_index(net,
> IPCB(skb)->iif);
> + if (!dev) {
> + kfree_skb(skb);
> + continue;
> + }
> + }
> + ip_mr_forward(net, mrt, dev, skb, c, 0);
> }
> }
> }
What about changing ipmr_cache_unresolved to take the dev it looked up
already and then have ipmr_cache_unresolved reset skb->dev to it (and
reset skb->skb_iff to dev->ifindex) when queuing to the unresolved list?
Since this path does not have a local delivery, resetting the skb->dev
will be fine and it avoids this second lookup using IPCB(skb)->iif:
@@ -1073,7 +1073,7 @@ static int ipmr_cache_report(struct mr_table *mrt,
/* Queue a packet for resolution. It gets locked cache entry! */
static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
- struct sk_buff *skb)
+ struct sk_buff *skb, struct net_device
*dev)
{
const struct iphdr *iph = ip_hdr(skb);
struct mfc_cache *c;
@@ -1130,6 +1130,10 @@ static int ipmr_cache_unresolved(struct mr_table
*mrt, vifi_t vifi,
kfree_skb(skb);
err = -ENOBUFS;
} else {
+ if (dev) {
+ skb->dev = dev;
+ skb->skb_iif = dev->ifindex;
+ }
skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
err = 0;
}
Combined with Thomas' earlier change this check in ip_mr_forward becomes:
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 9374b99c7c17..1393a4d18a9a 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1853,13 +1853,7 @@ static void ip_mr_forward(struct net *net, struct
mr_table *mrt,
}
/* Wrong interface: drop packet and (maybe) send PIM assert. */
- if (mrt->vif_table[vif].dev != skb->dev) {
- struct net_device *mdev;
-
- mdev = l3mdev_master_dev_rcu(mrt->vif_table[vif].dev);
- if (mdev == skb->dev)
- goto forward;
-
+ if (mrt->vif_table[vif].dev != dev) {
if (rt_is_output_route(skb_rtable(skb))) {
/* It is our own packet, looped back.
* Very complicated situation...
