ipv6 03/05: reassembly: use seperate reassembly queues for conntrack and local delivery

Patrick McHardy
2009-12-15T16:14:30Z

commit 0b5ccb2ee250136dd7385b1c7da28417d0d4d32d
Author: Patrick McHardy <kaber@trash.net>
Date: Tue Dec 15 16:59:18 2009 +0100

ipv6: reassembly: use seperate reassembly queues for conntrack and local delivery

Currently the same reassembly queue might be used for packets reassembled
by conntrack in different positions in the stack (PREROUTING/LOCAL_OUT),
as well as local delivery. This can cause "packet jumps" when the fragment
completing a reassembled packet is queued from a different position in the
stack than the previous ones.

Add a "user" identifier to the reassembly queue key to seperate the queues
of each caller, similar to what we do for IPv4.

Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 92db861..d691603 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -350,8 +350,15 @@ static inline int ipv6_prefix_equal(const struct in6_addr *a1,

struct inet_frag_queue;

+enum ip6_defrag_users {
+ IP6_DEFRAG_LOCAL_DELIVER,
+ IP6_DEFRAG_CONNTRACK_IN,
+ IP6_DEFRAG_CONNTRACK_OUT,
+};
+
struct ip6_create_arg {
__be32 id;
+ u32 user;
struct in6_addr *src;
struct in6_addr *dst;
};
diff --git a/include/net/netfilter/ipv6/nf_conntrack_ipv6.h b/include/net/netfilter/ipv6/nf_conntrack_ipv6.h
index abc55ad..1ee717e 100644
--- a/include/net/netfilter/ipv6/nf_conntrack_ipv6.h
+++ b/include/net/netfilter/ipv6/nf_conntrack_ipv6.h
@@ -9,7 +9,7 @@ extern struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6;

extern int nf_ct_frag6_init(void);
extern void nf_ct_frag6_cleanup(void);
-extern struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb);
+extern struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user);
extern void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
struct net_device *in,
struct net_device *out,
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 5f2ec20..c0a82fe 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -187,6 +187,16 @@ out:
return nf_conntrack_confirm(skb);
}

+static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
+ struct sk_buff *skb)
+{
+ if (hooknum == NF_INET_PRE_ROUTING)
+ return IP6_DEFRAG_CONNTRACK_IN;
+ else
+ return IP6_DEFRAG_CONNTRACK_OUT;
+
+}
+
static unsigned int ipv6_defrag(unsigned int hooknum,
struct sk_buff *skb,
const struct net_device *in,
@@ -199,8 +209,7 @@ static unsigned int ipv6_defrag(unsigned int hooknum,
if (skb->nfct)
return NF_ACCEPT;

- reasm = nf_ct_frag6_gather(skb);
-
+ reasm = nf_ct_frag6_gather(skb, nf_ct6_defrag_user(hooknum, skb));
/* queued */
if (reasm == NULL)
return NF_STOLEN;
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index e0b9424..312c20a 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -168,13 +168,14 @@ out:
/* Creation primitives. */

static __inline__ struct nf_ct_frag6_queue *
-fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
+fq_find(__be32 id, u32 user, struct in6_addr *src, struct in6_addr *dst)
{
struct inet_frag_queue *q;
struct ip6_create_arg arg;
unsigned int hash;

arg.id = id;
+ arg.user = user;
arg.src = src;
arg.dst = dst;

@@ -559,7 +560,7 @@ find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
return 0;
}

-struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
+struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user)
{
struct sk_buff *clone;
struct net_device *dev = skb->dev;
@@ -605,7 +606,7 @@ struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
if (atomic_read(&nf_init_frags.mem) > nf_init_frags.high_thresh)
nf_ct_frag6_evictor();

- fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
+ fq = fq_find(fhdr->identification, user, &hdr->saddr, &hdr->daddr);
if (fq == NULL) {
pr_debug("Can't find and can't create new queue\n");
goto ret_orig;
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 4d98549..3b3a956 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -72,6 +72,7 @@ struct frag_queue
struct inet_frag_queue q;

__be32 id; /* fragment id */
+ u32 user;
struct in6_addr saddr;
struct in6_addr daddr;

@@ -141,7 +142,7 @@ int ip6_frag_match(struct inet_frag_queue *q, void *a)
struct ip6_create_arg *arg = a;

fq = container_of(q, struct frag_queue, q);
- return (fq->id == arg->id &&
+ return (fq->id == arg->id && fq->user == arg->user &&
ipv6_addr_equal(&fq->saddr, arg->src) &&
ipv6_addr_equal(&fq->daddr, arg->dst));
}
@@ -163,6 +164,7 @@ void ip6_frag_init(struct inet_frag_queue *q, void *a)
struct ip6_create_arg *arg = a;

fq->id = arg->id;
+ fq->user = arg->user;
ipv6_addr_copy(&fq->saddr, arg->src);
ipv6_addr_copy(&fq->daddr, arg->dst);
}
@@ -243,6 +245,7 @@ fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst,
unsigned int hash;

arg.id = id;
+ arg.user = IP6_DEFRAG_LOCAL_DELIVER;
arg.src = src;
arg.dst = dst;