Commit 36d5fe6a authored by Zoltan Kiss's avatar Zoltan Kiss Committed by David S. Miller

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: default avatarZoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fc0d48b8
...@@ -2451,8 +2451,8 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset, ...@@ -2451,8 +2451,8 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
unsigned int flags); unsigned int flags);
void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
unsigned int skb_zerocopy_headlen(const struct sk_buff *from); unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
void skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
int len, int hlen); int len, int hlen);
void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len); void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
void skb_scrub_packet(struct sk_buff *skb, bool xnet); void skb_scrub_packet(struct sk_buff *skb, bool xnet);
......
...@@ -2127,25 +2127,31 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_headlen); ...@@ -2127,25 +2127,31 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_headlen);
* *
* The `hlen` as calculated by skb_zerocopy_headlen() specifies the * The `hlen` as calculated by skb_zerocopy_headlen() specifies the
* headroom in the `to` buffer. * 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 int
skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
{ {
int i, j = 0; int i, j = 0;
int plen = 0; /* length of skb->head fragment */ int plen = 0; /* length of skb->head fragment */
int ret;
struct page *page; struct page *page;
unsigned int offset; unsigned int offset;
BUG_ON(!from->head_frag && !hlen); BUG_ON(!from->head_frag && !hlen);
/* dont bother with small payloads */ /* dont bother with small payloads */
if (len <= skb_tailroom(to)) { if (len <= skb_tailroom(to))
skb_copy_bits(from, 0, skb_put(to, len), len); return skb_copy_bits(from, 0, skb_put(to, len), len);
return;
}
if (hlen) { 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; len -= hlen;
} else { } else {
plen = min_t(int, skb_headlen(from), len); 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) ...@@ -2163,6 +2169,11 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
to->len += len + plen; to->len += len + plen;
to->data_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++) { for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
if (!len) if (!len)
break; break;
...@@ -2173,6 +2184,8 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen) ...@@ -2173,6 +2184,8 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
j++; j++;
} }
skb_shinfo(to)->nr_frags = j; skb_shinfo(to)->nr_frags = j;
return 0;
} }
EXPORT_SYMBOL_GPL(skb_zerocopy); EXPORT_SYMBOL_GPL(skb_zerocopy);
......
...@@ -354,13 +354,16 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, ...@@ -354,13 +354,16 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
skb = nfnetlink_alloc_skb(net, size, queue->peer_portid, skb = nfnetlink_alloc_skb(net, size, queue->peer_portid,
GFP_ATOMIC); GFP_ATOMIC);
if (!skb) if (!skb) {
skb_tx_error(entskb);
return NULL; return NULL;
}
nlh = nlmsg_put(skb, 0, 0, nlh = nlmsg_put(skb, 0, 0,
NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
sizeof(struct nfgenmsg), 0); sizeof(struct nfgenmsg), 0);
if (!nlh) { if (!nlh) {
skb_tx_error(entskb);
kfree_skb(skb); kfree_skb(skb);
return NULL; return NULL;
} }
...@@ -488,13 +491,15 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, ...@@ -488,13 +491,15 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
nla->nla_type = NFQA_PAYLOAD; nla->nla_type = NFQA_PAYLOAD;
nla->nla_len = nla_attr_size(data_len); 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; nlh->nlmsg_len = skb->len;
return skb; return skb;
nla_put_failure: nla_put_failure:
skb_tx_error(entskb);
kfree_skb(skb); kfree_skb(skb);
net_err_ratelimited("nf_queue: error creating packet message\n"); net_err_ratelimited("nf_queue: error creating packet message\n");
return NULL; return NULL;
......
...@@ -464,7 +464,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, ...@@ -464,7 +464,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
} }
nla->nla_len = nla_attr_size(skb->len); 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 */ /* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
if (!(dp->user_features & OVS_DP_F_UNALIGNED)) { if (!(dp->user_features & OVS_DP_F_UNALIGNED)) {
...@@ -478,6 +480,8 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, ...@@ -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); err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);
out: out:
if (err)
skb_tx_error(skb);
kfree_skb(nskb); kfree_skb(nskb);
return err; return err;
} }
......
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