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authorZoltan Kiss <zoltan.kiss@citrix.com>2014-03-26 22:37:45 +0000
committerDavid S. Miller <davem@davemloft.net>2014-03-27 15:29:38 -0400
commit36d5fe6a000790f56039afe26834265db0a3ad4c (patch)
tree391de83f18ede9ca651ed347112ce4400e4645d5 /net
parentfc0d48b8fb449ca007b2057328abf736cb516168 (diff)
downloadlinux-linaro-stable-36d5fe6a000790f56039afe26834265db0a3ad4c.tar.gz
core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors
skb_zerocopy can copy elements of the frags array between skbs, but it doesn't orphan them. Also, it doesn't handle errors, so this patch takes care of that as well, and modify the callers accordingly. skb_tx_error() is also added to the callers so they will signal the failed delivery towards the creator of the skb. Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/skbuff.c27
-rw-r--r--net/netfilter/nfnetlink_queue_core.c9
-rw-r--r--net/openvswitch/datapath.c6
3 files changed, 32 insertions, 10 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 869c7afe3b07..97e5a2c3d947 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2127,25 +2127,31 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_headlen);
*
* The `hlen` as calculated by skb_zerocopy_headlen() specifies the
* headroom in the `to` buffer.
+ *
+ * Return value:
+ * 0: everything is OK
+ * -ENOMEM: couldn't orphan frags of @from due to lack of memory
+ * -EFAULT: skb_copy_bits() found some problem with skb geometry
*/
-void
-skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
+int
+skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
{
int i, j = 0;
int plen = 0; /* length of skb->head fragment */
+ int ret;
struct page *page;
unsigned int offset;
BUG_ON(!from->head_frag && !hlen);
/* dont bother with small payloads */
- if (len <= skb_tailroom(to)) {
- skb_copy_bits(from, 0, skb_put(to, len), len);
- return;
- }
+ if (len <= skb_tailroom(to))
+ return skb_copy_bits(from, 0, skb_put(to, len), len);
if (hlen) {
- skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
+ ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
+ if (unlikely(ret))
+ return ret;
len -= hlen;
} else {
plen = min_t(int, skb_headlen(from), len);
@@ -2163,6 +2169,11 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
to->len += len + plen;
to->data_len += len + plen;
+ if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {
+ skb_tx_error(from);
+ return -ENOMEM;
+ }
+
for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
if (!len)
break;
@@ -2173,6 +2184,8 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
j++;
}
skb_shinfo(to)->nr_frags = j;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(skb_zerocopy);
diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c
index f072fe803510..108120f216b1 100644
--- a/net/netfilter/nfnetlink_queue_core.c
+++ b/net/netfilter/nfnetlink_queue_core.c
@@ -354,13 +354,16 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
skb = nfnetlink_alloc_skb(net, size, queue->peer_portid,
GFP_ATOMIC);
- if (!skb)
+ if (!skb) {
+ skb_tx_error(entskb);
return NULL;
+ }
nlh = nlmsg_put(skb, 0, 0,
NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
sizeof(struct nfgenmsg), 0);
if (!nlh) {
+ skb_tx_error(entskb);
kfree_skb(skb);
return NULL;
}
@@ -488,13 +491,15 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
nla->nla_type = NFQA_PAYLOAD;
nla->nla_len = nla_attr_size(data_len);
- skb_zerocopy(skb, entskb, data_len, hlen);
+ if (skb_zerocopy(skb, entskb, data_len, hlen))
+ goto nla_put_failure;
}
nlh->nlmsg_len = skb->len;
return skb;
nla_put_failure:
+ skb_tx_error(entskb);
kfree_skb(skb);
net_err_ratelimited("nf_queue: error creating packet message\n");
return NULL;
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 8601b320b443..270b77dfac30 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -464,7 +464,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
}
nla->nla_len = nla_attr_size(skb->len);
- skb_zerocopy(user_skb, skb, skb->len, hlen);
+ err = skb_zerocopy(user_skb, skb, skb->len, hlen);
+ if (err)
+ goto out;
/* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
@@ -478,6 +480,8 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);
out:
+ if (err)
+ skb_tx_error(skb);
kfree_skb(nskb);
return err;
}