IB/IPoIB: Add destination address when re-queue packet

When sending packet to destination that was not resolved yet
via path query, the driver keeps the skb and tries to re-send it
again when the path is resolved.

But when re-sending via dev_queue_xmit the kernel doesn't call
to dev_hard_header, so IPoIB needs to keep 20 bytes in the skb
and to put the destination address inside them.

In that way the dev_start_xmit will have the correct destination,
and the driver won't take the destination from the skb->data, while
nothing exists there, which causes to packet be be dropped.

The test flow is:
1. Run the SM on remote node,
2. Restart the driver.
4. Ping some destination,
3. Observe that first ICMP request will be dropped.

Fixes: fc791b633515 ("IB/ipoib: move back IB LL address into the hard header")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Tested-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 17 insertions, 13 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index e3bfa8a99ad2..259c59f67394 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -721,6 +721,14 @@ int ipoib_check_sm_sendonly_fullmember_support(struct ipoib_dev_priv *priv)
         return ret;
 }
 
+static void push_pseudo_header(struct sk_buff *skb, const char *daddr)
+{
+        struct ipoib_pseudo_header *phdr;
+
+        phdr = (struct ipoib_pseudo_header *)skb_push(skb, sizeof(*phdr));
+        memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
+}
+
 void ipoib_flush_paths(struct net_device *dev)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
@@ -947,8 +955,7 @@ static void neigh_add_path(struct sk_buff *skb, u8 *daddr,
                         }
                         if (skb_queue_len(&neigh->queue) <
                             IPOIB_MAX_PATH_REC_QUEUE) {
-                                /* put pseudoheader back on for next time */
-                                skb_push(skb, IPOIB_PSEUDO_LEN);
+                                push_pseudo_header(skb, neigh->daddr);
                                 __skb_queue_tail(&neigh->queue, skb);
                         } else {
                                 ipoib_warn(priv, "queue length limit %d. Packet drop.\n",
@@ -966,10 +973,12 @@ static void neigh_add_path(struct sk_buff *skb, u8 *daddr,
 
                 if (!path->query && path_rec_start(dev, path))
                         goto err_path;
-                if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE)
+                if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
+                        push_pseudo_header(skb, neigh->daddr);
                         __skb_queue_tail(&neigh->queue, skb);
-                else
+                } else {
                         goto err_drop;
+                }
         }
 
         spin_unlock_irqrestore(&priv->lock, flags);
@@ -1005,8 +1014,7 @@ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
                 }
                 if (path) {
                         if (skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
-                                /* put pseudoheader back on for next time */
-                                skb_push(skb, IPOIB_PSEUDO_LEN);
+                                push_pseudo_header(skb, phdr->hwaddr);
                                 __skb_queue_tail(&path->queue, skb);
                         } else {
                                 ++dev->stats.tx_dropped;
@@ -1038,8 +1046,7 @@ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
                 return;
         } else if ((path->query || !path_rec_start(dev, path)) &&
                    skb_queue_len(&path->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
-                /* put pseudoheader back on for next time */
-                skb_push(skb, IPOIB_PSEUDO_LEN);
+                push_pseudo_header(skb, phdr->hwaddr);
                 __skb_queue_tail(&path->queue, skb);
         } else {
                 ++dev->stats.tx_dropped;
@@ -1120,8 +1127,7 @@ send_using_neigh:
         }
 
         if (skb_queue_len(&neigh->queue) < IPOIB_MAX_PATH_REC_QUEUE) {
-                /* put pseudoheader back on for next time */
-                skb_push(skb, sizeof(*phdr));
+                push_pseudo_header(skb, phdr->hwaddr);
                 spin_lock_irqsave(&priv->lock, flags);
                 __skb_queue_tail(&neigh->queue, skb);
                 spin_unlock_irqrestore(&priv->lock, flags);
@@ -1153,7 +1159,6 @@ static int ipoib_hard_header(struct sk_buff *skb,
                              unsigned short type,
                              const void *daddr, const void *saddr, unsigned len)
 {
-        struct ipoib_pseudo_header *phdr;
         struct ipoib_header *header;
 
         header = (struct ipoib_header *) skb_push(skb, sizeof *header);
@@ -1166,8 +1171,7 @@ static int ipoib_hard_header(struct sk_buff *skb,
          * destination address into skb hard header so we can figure out where
          * to send the packet later.
          */
-        phdr = (struct ipoib_pseudo_header *) skb_push(skb, sizeof(*phdr));
-        memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
+        push_pseudo_header(skb, daddr);
 
         return IPOIB_HARD_LEN;
 }