[PATCH 4.9 39/41] ipv6: remove dependency of nf_defrag_ipv6 on ipv6 module

From: Greg Kroah-Hartman
Date: Tue Apr 30 2019 - 07:40:57 EST


From: Florian Westphal <fw@xxxxxxxxx>

[ Upstream commit 70b095c84326640eeacfd69a411db8fc36e8ab1a ]

IPV6=m
DEFRAG_IPV6=m
CONNTRACK=y yields:

net/netfilter/nf_conntrack_proto.o: In function `nf_ct_netns_do_get':
net/netfilter/nf_conntrack_proto.c:802: undefined reference to `nf_defrag_ipv6_enable'
net/netfilter/nf_conntrack_proto.o:(.rodata+0x640): undefined reference to `nf_conntrack_l4proto_icmpv6'

Setting DEFRAG_IPV6=y causes undefined references to ip6_rhash_params
ip6_frag_init and ip6_expire_frag_queue so it would be needed to force
IPV6=y too.

This patch gets rid of the 'followup linker error' by removing
the dependency of ipv6.ko symbols from netfilter ipv6 defrag.

Shared code is placed into a header, then used from both.

Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/ipv6.h | 29 --------
include/net/ipv6_frag.h | 104 ++++++++++++++++++++++++++++++
net/ieee802154/6lowpan/reassembly.c | 2
net/ipv6/netfilter/nf_conntrack_reasm.c | 17 +++-
net/ipv6/netfilter/nf_defrag_ipv6_hooks.c | 3
net/ipv6/reassembly.c | 92 ++------------------------
net/openvswitch/conntrack.c | 1
7 files changed, 126 insertions(+), 122 deletions(-)
create mode 100644 include/net/ipv6_frag.h

--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -511,35 +511,6 @@ static inline bool ipv6_prefix_equal(con
}
#endif

-struct inet_frag_queue;
-
-enum ip6_defrag_users {
- IP6_DEFRAG_LOCAL_DELIVER,
- IP6_DEFRAG_CONNTRACK_IN,
- __IP6_DEFRAG_CONNTRACK_IN = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
- IP6_DEFRAG_CONNTRACK_OUT,
- __IP6_DEFRAG_CONNTRACK_OUT = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
- IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
- __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
-};
-
-void ip6_frag_init(struct inet_frag_queue *q, const void *a);
-extern const struct rhashtable_params ip6_rhash_params;
-
-/*
- * Equivalent of ipv4 struct ip
- */
-struct frag_queue {
- struct inet_frag_queue q;
-
- int iif;
- unsigned int csum;
- __u16 nhoffset;
- u8 ecn;
-};
-
-void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq);
-
static inline bool ipv6_addr_any(const struct in6_addr *a)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
--- /dev/null
+++ b/include/net/ipv6_frag.h
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _IPV6_FRAG_H
+#define _IPV6_FRAG_H
+#include <linux/kernel.h>
+#include <net/addrconf.h>
+#include <net/ipv6.h>
+#include <net/inet_frag.h>
+
+enum ip6_defrag_users {
+ IP6_DEFRAG_LOCAL_DELIVER,
+ IP6_DEFRAG_CONNTRACK_IN,
+ __IP6_DEFRAG_CONNTRACK_IN = IP6_DEFRAG_CONNTRACK_IN + USHRT_MAX,
+ IP6_DEFRAG_CONNTRACK_OUT,
+ __IP6_DEFRAG_CONNTRACK_OUT = IP6_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
+ IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
+ __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
+};
+
+/*
+ * Equivalent of ipv4 struct ip
+ */
+struct frag_queue {
+ struct inet_frag_queue q;
+
+ int iif;
+ __u16 nhoffset;
+ u8 ecn;
+};
+
+#if IS_ENABLED(CONFIG_IPV6)
+static inline void ip6frag_init(struct inet_frag_queue *q, const void *a)
+{
+ struct frag_queue *fq = container_of(q, struct frag_queue, q);
+ const struct frag_v6_compare_key *key = a;
+
+ q->key.v6 = *key;
+ fq->ecn = 0;
+}
+
+static inline u32 ip6frag_key_hashfn(const void *data, u32 len, u32 seed)
+{
+ return jhash2(data,
+ sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
+}
+
+static inline u32 ip6frag_obj_hashfn(const void *data, u32 len, u32 seed)
+{
+ const struct inet_frag_queue *fq = data;
+
+ return jhash2((const u32 *)&fq->key.v6,
+ sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
+}
+
+static inline int
+ip6frag_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
+{
+ const struct frag_v6_compare_key *key = arg->key;
+ const struct inet_frag_queue *fq = ptr;
+
+ return !!memcmp(&fq->key, key, sizeof(*key));
+}
+
+static inline void
+ip6frag_expire_frag_queue(struct net *net, struct frag_queue *fq)
+{
+ struct net_device *dev = NULL;
+ struct sk_buff *head;
+
+ rcu_read_lock();
+ spin_lock(&fq->q.lock);
+
+ if (fq->q.flags & INET_FRAG_COMPLETE)
+ goto out;
+
+ inet_frag_kill(&fq->q);
+
+ dev = dev_get_by_index_rcu(net, fq->iif);
+ if (!dev)
+ goto out;
+
+ __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
+ __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
+
+ /* Don't send error if the first segment did not arrive. */
+ head = fq->q.fragments;
+ if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head)
+ goto out;
+
+ head->dev = dev;
+ skb_get(head);
+ spin_unlock(&fq->q.lock);
+
+ icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
+ kfree_skb(head);
+ goto out_rcu_unlock;
+
+out:
+ spin_unlock(&fq->q.lock);
+out_rcu_unlock:
+ rcu_read_unlock();
+ inet_frag_put(&fq->q);
+}
+#endif
+#endif
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -25,7 +25,7 @@

#include <net/ieee802154_netdev.h>
#include <net/6lowpan.h>
-#include <net/ipv6.h>
+#include <net/ipv6_frag.h>
#include <net/inet_frag.h>

#include "6lowpan_i.h"
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -33,9 +33,8 @@

#include <net/sock.h>
#include <net/snmp.h>
-#include <net/inet_frag.h>
+#include <net/ipv6_frag.h>

-#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/rawv6.h>
@@ -158,7 +157,7 @@ static void nf_ct_frag6_expire(unsigned
fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
net = container_of(fq->q.net, struct net, nf_frag.frags);

- ip6_expire_frag_queue(net, fq);
+ ip6frag_expire_frag_queue(net, fq);
}

/* Creation primitives. */
@@ -634,16 +633,24 @@ static struct pernet_operations nf_ct_ne
.exit = nf_ct_net_exit,
};

+static const struct rhashtable_params nfct_rhash_params = {
+ .head_offset = offsetof(struct inet_frag_queue, node),
+ .hashfn = ip6frag_key_hashfn,
+ .obj_hashfn = ip6frag_obj_hashfn,
+ .obj_cmpfn = ip6frag_obj_cmpfn,
+ .automatic_shrinking = true,
+};
+
int nf_ct_frag6_init(void)
{
int ret = 0;

- nf_frags.constructor = ip6_frag_init;
+ nf_frags.constructor = ip6frag_init;
nf_frags.destructor = NULL;
nf_frags.qsize = sizeof(struct frag_queue);
nf_frags.frag_expire = nf_ct_frag6_expire;
nf_frags.frags_cache_name = nf_frags_cache_name;
- nf_frags.rhash_params = ip6_rhash_params;
+ nf_frags.rhash_params = nfct_rhash_params;
ret = inet_frags_init(&nf_frags);
if (ret)
goto out;
--- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
+++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
@@ -14,8 +14,7 @@
#include <linux/skbuff.h>
#include <linux/icmp.h>
#include <linux/sysctl.h>
-#include <net/ipv6.h>
-#include <net/inet_frag.h>
+#include <net/ipv6_frag.h>

#include <linux/netfilter_ipv6.h>
#include <linux/netfilter_bridge.h>
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -57,7 +57,7 @@
#include <net/rawv6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
-#include <net/inet_frag.h>
+#include <net/ipv6_frag.h>
#include <net/inet_ecn.h>

static const char ip6_frag_cache_name[] = "ip6-frags";
@@ -79,61 +79,6 @@ static struct inet_frags ip6_frags;
static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
struct net_device *dev);

-void ip6_frag_init(struct inet_frag_queue *q, const void *a)
-{
- struct frag_queue *fq = container_of(q, struct frag_queue, q);
- const struct frag_v6_compare_key *key = a;
-
- q->key.v6 = *key;
- fq->ecn = 0;
-}
-EXPORT_SYMBOL(ip6_frag_init);
-
-void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)
-{
- struct net_device *dev = NULL;
- struct sk_buff *head;
-
- rcu_read_lock();
- spin_lock(&fq->q.lock);
-
- if (fq->q.flags & INET_FRAG_COMPLETE)
- goto out;
-
- inet_frag_kill(&fq->q);
-
- dev = dev_get_by_index_rcu(net, fq->iif);
- if (!dev)
- goto out;
-
- __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
- __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
-
- /* Don't send error if the first segment did not arrive. */
- head = fq->q.fragments;
- if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head)
- goto out;
-
- /* But use as source device on which LAST ARRIVED
- * segment was received. And do not use fq->dev
- * pointer directly, device might already disappeared.
- */
- head->dev = dev;
- skb_get(head);
- spin_unlock(&fq->q.lock);
-
- icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
- kfree_skb(head);
- goto out_rcu_unlock;
-
-out:
- spin_unlock(&fq->q.lock);
-out_rcu_unlock:
- rcu_read_unlock();
- inet_frag_put(&fq->q);
-}
-EXPORT_SYMBOL(ip6_expire_frag_queue);
-
static void ip6_frag_expire(unsigned long data)
{
struct frag_queue *fq;
@@ -142,7 +87,7 @@ static void ip6_frag_expire(unsigned lon
fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
net = container_of(fq->q.net, struct net, ipv6.frags);

- ip6_expire_frag_queue(net, fq);
+ ip6frag_expire_frag_queue(net, fq);
}

static struct frag_queue *
@@ -701,42 +646,19 @@ static struct pernet_operations ip6_frag
.exit = ipv6_frags_exit_net,
};

-static u32 ip6_key_hashfn(const void *data, u32 len, u32 seed)
-{
- return jhash2(data,
- sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
-}
-
-static u32 ip6_obj_hashfn(const void *data, u32 len, u32 seed)
-{
- const struct inet_frag_queue *fq = data;
-
- return jhash2((const u32 *)&fq->key.v6,
- sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
-}
-
-static int ip6_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
-{
- const struct frag_v6_compare_key *key = arg->key;
- const struct inet_frag_queue *fq = ptr;
-
- return !!memcmp(&fq->key, key, sizeof(*key));
-}
-
-const struct rhashtable_params ip6_rhash_params = {
+static const struct rhashtable_params ip6_rhash_params = {
.head_offset = offsetof(struct inet_frag_queue, node),
- .hashfn = ip6_key_hashfn,
- .obj_hashfn = ip6_obj_hashfn,
- .obj_cmpfn = ip6_obj_cmpfn,
+ .hashfn = ip6frag_key_hashfn,
+ .obj_hashfn = ip6frag_obj_hashfn,
+ .obj_cmpfn = ip6frag_obj_cmpfn,
.automatic_shrinking = true,
};
-EXPORT_SYMBOL(ip6_rhash_params);

int __init ipv6_frag_init(void)
{
int ret;

- ip6_frags.constructor = ip6_frag_init;
+ ip6_frags.constructor = ip6frag_init;
ip6_frags.destructor = NULL;
ip6_frags.qsize = sizeof(struct frag_queue);
ip6_frags.frag_expire = ip6_frag_expire;
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -23,6 +23,7 @@
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
+#include <net/ipv6_frag.h>

#ifdef CONFIG_NF_NAT_NEEDED
#include <linux/netfilter/nf_nat.h>