From: wenxu <wenxu@xxxxxxxxx>
Add ip_defrag_ignore_cb for conntrack defrag and it will
elide the CB clear when packets are defragmented by
connection tracking.
Signed-off-by: wenxu <wenxu@xxxxxxxxx>
---
include/net/ip.h | 2 ++
net/ipv4/ip_fragment.c | 55 ++++++++++++++++++++++++++++++++++++++++++--------
2 files changed, 49 insertions(+), 8 deletions(-)
diff --git a/include/net/ip.h b/include/net/ip.h
index 862c954..31779a5 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -671,6 +671,8 @@ static inline bool ip_defrag_user_in_between(u32 user,
}
int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
+int ip_defrag_ignore_cb(struct net *net, struct sk_buff *skb,
+ u32 user, u16 *frag_max_size);
#ifdef CONFIG_INET
struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
#else
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index cfeb889..afc2b3d 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -76,7 +76,8 @@ static u8 ip4_frag_ecn(u8 tos)
static struct inet_frags ip4_frags;
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
- struct sk_buff *prev_tail, struct net_device *dev);
+ struct sk_buff *prev_tail, struct net_device *dev,
+ bool ignore_skb_cb, u16 *frag_max_size);
static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
@@ -269,7 +270,8 @@ static int ip_frag_reinit(struct ipq *qp)
}
/* Add new segment to existing queue. */
-static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
+static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb,
+ bool ignore_skb_cb, u16 *frag_max_size)
{
struct net *net = qp->q.fqdir->net;
int ihl, end, flags, offset;
@@ -282,7 +284,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
if (qp->q.flags & INET_FRAG_COMPLETE)
goto err;
- if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
+ if ((ignore_skb_cb || !(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE)) &&
unlikely(ip_frag_too_far(qp)) &&
unlikely(err = ip_frag_reinit(qp))) {
ipq_kill(qp);
@@ -368,7 +370,8 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
unsigned long orefdst = skb->_skb_refdst;
skb->_skb_refdst = 0UL;
- err = ip_frag_reasm(qp, skb, prev_tail, dev);
+ err = ip_frag_reasm(qp, skb, prev_tail, dev, ignore_skb_cb,
+ frag_max_size);
skb->_skb_refdst = orefdst;
if (err)
inet_frag_kill(&qp->q);
@@ -400,7 +403,8 @@ static bool ip_frag_coalesce_ok(const struct ipq *qp)
/* Build a new IP datagram from all its fragments. */
static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
- struct sk_buff *prev_tail, struct net_device *dev)
+ struct sk_buff *prev_tail, struct net_device *dev,
+ bool ignore_skb_cb, u16 *frag_max_size)
{
struct net *net = qp->q.fqdir->net;
struct iphdr *iph;
@@ -430,7 +434,10 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
ip_frag_coalesce_ok(qp));
skb->dev = dev;
- IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
+ if (!ignore_skb_cb)
+ IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
+ else if (frag_max_size)
+ *frag_max_size = max(qp->max_df_size, qp->q.max_size);
iph = ip_hdr(skb);
iph->tot_len = htons(len);
@@ -445,7 +452,8 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
* from one very small df-fragment and one large non-df frag.
*/
if (qp->max_df_size == qp->q.max_size) {
- IPCB(skb)->flags |= IPSKB_FRAG_PMTU;
+ if (!ignore_skb_cb)
+ IPCB(skb)->flags |= IPSKB_FRAG_PMTU;
iph->frag_off = htons(IP_DF);
} else {
iph->frag_off = 0;
@@ -487,7 +495,7 @@ int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
spin_lock(&qp->q.lock);
- ret = ip_frag_queue(qp, skb);
+ ret = ip_frag_queue(qp, skb, false, NULL);
spin_unlock(&qp->q.lock);
ipq_put(qp);
@@ -500,6 +508,37 @@ int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
}
EXPORT_SYMBOL(ip_defrag);
+/* Process an incoming IP datagram fragment. */
+int ip_defrag_ignore_cb(struct net *net, struct sk_buff *skb,
+ u32 user, u16 *frag_max_size)
+{
+ struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
+ int vif = l3mdev_master_ifindex_rcu(dev);
+ struct ipq *qp;
+
+ __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS);
+ skb_orphan(skb);
+
+ /* Lookup (or create) queue header */
+ qp = ip_find(net, ip_hdr(skb), user, vif);
+ if (qp) {
+ int ret;
+
+ spin_lock_bh(&qp->q.lock);
+
+ ret = ip_frag_queue(qp, skb, true, frag_max_size);
+
+ spin_unlock_bh(&qp->q.lock);
+ ipq_put(qp);
+ return ret;
+ }
+
+ __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
+ kfree_skb(skb);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL(ip_defrag_ignore_cb);
+
struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
{
struct iphdr iph;
--
1.8.3.1
