netfilter: nfnetlink_queue: return error number to caller
instead of returning -1 on error, return an error number to allow the
caller to handle some errors differently.
ECANCELED is used to indicate that the hook is going away and should be
ignored.
A followup patch will introduce more 'ignore this hook' conditions,
(depending on queue settings) and will move kfree_skb responsibility
to the caller.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index e69d537..91d66d2f 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -179,9 +179,11 @@
if (ret == 0)
ret = -EPERM;
} else if ((verdict & NF_VERDICT_MASK) == NF_QUEUE) {
- if (!nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
- verdict >> NF_VERDICT_BITS))
+ ret = nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
+ verdict >> NF_VERDICT_BITS);
+ if (ret == -ECANCELED)
goto next_hook;
+ ret = 0;
}
rcu_read_unlock();
return ret;
diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index 1876f74..ad25c7e 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -125,7 +125,7 @@
int (*okfn)(struct sk_buff *),
unsigned int queuenum)
{
- int status;
+ int status = -ENOENT;
struct nf_queue_entry *entry = NULL;
#ifdef CONFIG_BRIDGE_NETFILTER
struct net_device *physindev;
@@ -146,8 +146,10 @@
goto err_unlock;
entry = kmalloc(sizeof(*entry) + afinfo->route_key_size, GFP_ATOMIC);
- if (!entry)
+ if (!entry) {
+ status = -ENOMEM;
goto err_unlock;
+ }
*entry = (struct nf_queue_entry) {
.skb = skb,
@@ -163,9 +165,8 @@
if (!try_module_get(entry->elem->owner)) {
rcu_read_unlock();
kfree(entry);
- return 0;
+ return -ECANCELED;
}
-
/* Bump dev refs so they don't vanish while packet is out */
if (indev)
dev_hold(indev);
@@ -192,14 +193,14 @@
goto err;
}
- return 1;
+ return 0;
err_unlock:
rcu_read_unlock();
err:
kfree_skb(skb);
kfree(entry);
- return 1;
+ return status;
}
int nf_queue(struct sk_buff *skb,
@@ -211,6 +212,8 @@
unsigned int queuenum)
{
struct sk_buff *segs;
+ int err;
+ unsigned int queued;
if (!skb_is_gso(skb))
return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn,
@@ -227,19 +230,32 @@
segs = skb_gso_segment(skb, 0);
kfree_skb(skb);
+ /* Does not use PTR_ERR to limit the number of error codes that can be
+ * returned by nf_queue. For instance, callers rely on -ECANCELED to mean
+ * 'ignore this hook'.
+ */
if (IS_ERR(segs))
- return 1;
+ return -EINVAL;
+ queued = 0;
+ err = 0;
do {
struct sk_buff *nskb = segs->next;
segs->next = NULL;
- if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn,
- queuenum))
+ if (err == 0)
+ err = __nf_queue(segs, elem, pf, hook, indev,
+ outdev, okfn, queuenum);
+ if (err == 0)
+ queued++;
+ else
kfree_skb(segs);
segs = nskb;
} while (segs);
- return 1;
+
+ if (unlikely(err && queued))
+ err = 0;
+ return err;
}
void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict)
@@ -247,6 +263,7 @@
struct sk_buff *skb = entry->skb;
struct list_head *elem = &entry->elem->list;
const struct nf_afinfo *afinfo;
+ int err;
rcu_read_lock();
@@ -280,9 +297,10 @@
local_bh_enable();
break;
case NF_QUEUE:
- if (!__nf_queue(skb, elem, entry->pf, entry->hook,
- entry->indev, entry->outdev, entry->okfn,
- verdict >> NF_VERDICT_BITS))
+ err = __nf_queue(skb, elem, entry->pf, entry->hook,
+ entry->indev, entry->outdev, entry->okfn,
+ verdict >> NF_VERDICT_BITS);
+ if (err == -ECANCELED)
goto next_hook;
break;
case NF_STOLEN:
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 68e67d1..b83123f 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -387,25 +387,31 @@
{
struct sk_buff *nskb;
struct nfqnl_instance *queue;
- int err;
+ int err = -ENOBUFS;
/* rcu_read_lock()ed by nf_hook_slow() */
queue = instance_lookup(queuenum);
- if (!queue)
+ if (!queue) {
+ err = -ESRCH;
goto err_out;
+ }
- if (queue->copy_mode == NFQNL_COPY_NONE)
+ if (queue->copy_mode == NFQNL_COPY_NONE) {
+ err = -EINVAL;
goto err_out;
+ }
nskb = nfqnl_build_packet_message(queue, entry);
- if (nskb == NULL)
+ if (nskb == NULL) {
+ err = -ENOMEM;
goto err_out;
-
+ }
spin_lock_bh(&queue->lock);
- if (!queue->peer_pid)
+ if (!queue->peer_pid) {
+ err = -EINVAL;
goto err_out_free_nskb;
-
+ }
if (queue->queue_total >= queue->queue_maxlen) {
queue->queue_dropped++;
if (net_ratelimit())
@@ -432,7 +438,7 @@
err_out_unlock:
spin_unlock_bh(&queue->lock);
err_out:
- return -1;
+ return err;
}
static int
