diff mbox

[1/1] netfilter: constify nf_conntrack_l3/4proto parameters

Message ID 1501356197-26490-2-git-send-email-Julia.Lawall@lip6.fr
State Awaiting Upstream, archived
Delegated to: David Miller
Headers show

Commit Message

Julia Lawall July 29, 2017, 7:23 p.m. UTC 
When a nf_conntrack_l3/4proto parameter is not on the left hand side
of an assignment, its address is not taken, and it is not passed to a
function that may modify its fields, then it can be declared as const.

This change is useful from a documentation point of view, and can
possibly facilitate making some nf_conntrack_l3/4proto structures const
subsequently.

Done with the help of Coccinelle.

Some spacing adjusted to fit within 80 characters.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 include/net/netfilter/nf_conntrack_l3proto.h |    6 +++---
 include/net/netfilter/nf_conntrack_l4proto.h |    8 ++++----
 include/net/netfilter/nf_conntrack_timeout.h |    2 +-
 net/netfilter/nf_conntrack_core.c            |    8 ++++----
 net/netfilter/nf_conntrack_netlink.c         |    6 +++---
 net/netfilter/nf_conntrack_proto.c           |   20 ++++++++++----------
 net/netfilter/nfnetlink_cttimeout.c          |    2 +-
 7 files changed, 26 insertions(+), 26 deletions(-)

Comments

Florian Westphal July 29, 2017, 8:03 p.m. UTC | #1 
Julia Lawall <Julia.Lawall@lip6.fr> wrote:
> When a nf_conntrack_l3/4proto parameter is not on the left hand side
> of an assignment, its address is not taken, and it is not passed to a
> function that may modify its fields, then it can be declared as const.
> 
> This change is useful from a documentation point of view, and can
> possibly facilitate making some nf_conntrack_l3/4proto structures const
> subsequently.
> 
> Done with the help of Coccinelle.
> 
> Some spacing adjusted to fit within 80 characters.

Acked-by: Florian Westphal <fw@strlen.de>

Thanks Julia.

I think we can indeed constify these completely after making
'nla_size' set at compile time.

I'll send a simple attempt to make it so for l3proto soon.
Julia Lawall July 29, 2017, 8:18 p.m. UTC | #2 
On Sat, 29 Jul 2017, Florian Westphal wrote:

> Julia Lawall <Julia.Lawall@lip6.fr> wrote:
> > When a nf_conntrack_l3/4proto parameter is not on the left hand side
> > of an assignment, its address is not taken, and it is not passed to a
> > function that may modify its fields, then it can be declared as const.
> >
> > This change is useful from a documentation point of view, and can
> > possibly facilitate making some nf_conntrack_l3/4proto structures const
> > subsequently.
> >
> > Done with the help of Coccinelle.
> >
> > Some spacing adjusted to fit within 80 characters.
>
> Acked-by: Florian Westphal <fw@strlen.de>
>
> Thanks Julia.
>
> I think we can indeed constify these completely after making
> 'nla_size' set at compile time.
>
> I'll send a simple attempt to make it so for l3proto soon.

There is another issue with respect to nf_ct_l3proto_unregister.  This
calls nf_ct_iterate_destroy with l3proto as the second argument.  This
function has signature:

void
nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data), void *data)

The void * is not const.  Maybe it could be.

julia

> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
Florian Westphal July 29, 2017, 9:22 p.m. UTC | #3 
Julia Lawall <julia.lawall@lip6.fr> wrote:
> > I think we can indeed constify these completely after making
> > 'nla_size' set at compile time.
> >
> > I'll send a simple attempt to make it so for l3proto soon.
> 
> There is another issue with respect to nf_ct_l3proto_unregister.  This
> calls nf_ct_iterate_destroy with l3proto as the second argument.  This
> function has signature:
> 
> void
> nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data), void *data)
> 
> The void * is not const.  Maybe it could be.

Haven't looked if we can constify it in general, but, as the argument
is not going to be written to in this particular case it will not be
a showstopper.
diff mbox

Patch

diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h
index 6d14b36..4782b15 100644
--- a/include/net/netfilter/nf_conntrack_l3proto.h
+++ b/include/net/netfilter/nf_conntrack_l3proto.h
@@ -76,17 +76,17 @@  struct nf_conntrack_l3proto {
 #ifdef CONFIG_SYSCTL
 /* Protocol pernet registration. */
 int nf_ct_l3proto_pernet_register(struct net *net,
-				  struct nf_conntrack_l3proto *proto);
+				  const struct nf_conntrack_l3proto *proto);
 #else
 static inline int nf_ct_l3proto_pernet_register(struct net *n,
-						struct nf_conntrack_l3proto *p)
+					const struct nf_conntrack_l3proto *p)
 {
 	return 0;
 }
 #endif
 
 void nf_ct_l3proto_pernet_unregister(struct net *net,
-				     struct nf_conntrack_l3proto *proto);
+				     const struct nf_conntrack_l3proto *proto);
 
 /* Protocol global registration. */
 int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto);
diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index 7032e04..72589b7 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -125,13 +125,13 @@  struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
 
 struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
 						    u_int8_t l4proto);
-void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
+void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p);
 
 /* Protocol pernet registration. */
 int nf_ct_l4proto_pernet_register_one(struct net *net,
-				      struct nf_conntrack_l4proto *proto);
+				      const struct nf_conntrack_l4proto *proto);
 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
-					 struct nf_conntrack_l4proto *proto);
+				const struct nf_conntrack_l4proto *proto);
 int nf_ct_l4proto_pernet_register(struct net *net,
 				  struct nf_conntrack_l4proto *proto[],
 				  unsigned int num_proto);
@@ -141,7 +141,7 @@  void nf_ct_l4proto_pernet_unregister(struct net *net,
 
 /* Protocol global registration. */
 int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *proto);
-void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *proto);
+void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *proto);
 int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto[],
 			   unsigned int num_proto);
 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto[],
diff --git a/include/net/netfilter/nf_conntrack_timeout.h b/include/net/netfilter/nf_conntrack_timeout.h
index d40b893..b222957 100644
--- a/include/net/netfilter/nf_conntrack_timeout.h
+++ b/include/net/netfilter/nf_conntrack_timeout.h
@@ -68,7 +68,7 @@  struct nf_conn_timeout *nf_ct_timeout_ext_add(struct nf_conn *ct,
 
 static inline unsigned int *
 nf_ct_timeout_lookup(struct net *net, struct nf_conn *ct,
-		     struct nf_conntrack_l4proto *l4proto)
+		     const struct nf_conntrack_l4proto *l4proto)
 {
 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 	struct nf_conn_timeout *timeout_ext;
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 51390fe..ed4e04e 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1183,8 +1183,8 @@  void nf_conntrack_free(struct nf_conn *ct)
 static noinline struct nf_conntrack_tuple_hash *
 init_conntrack(struct net *net, struct nf_conn *tmpl,
 	       const struct nf_conntrack_tuple *tuple,
-	       struct nf_conntrack_l3proto *l3proto,
-	       struct nf_conntrack_l4proto *l4proto,
+	       const struct nf_conntrack_l3proto *l3proto,
+	       const struct nf_conntrack_l4proto *l4proto,
 	       struct sk_buff *skb,
 	       unsigned int dataoff, u32 hash)
 {
@@ -1295,8 +1295,8 @@  void nf_conntrack_free(struct nf_conn *ct)
 		  unsigned int dataoff,
 		  u_int16_t l3num,
 		  u_int8_t protonum,
-		  struct nf_conntrack_l3proto *l3proto,
-		  struct nf_conntrack_l4proto *l4proto)
+		  const struct nf_conntrack_l3proto *l3proto,
+		  const struct nf_conntrack_l4proto *l4proto)
 {
 	const struct nf_conntrack_zone *zone;
 	struct nf_conntrack_tuple tuple;
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 7999e70..5d08602 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -61,8 +61,8 @@ 
 static char __initdata version[] = "0.93";
 
 static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
-				       const struct nf_conntrack_tuple *tuple,
-				       struct nf_conntrack_l4proto *l4proto)
+				const struct nf_conntrack_tuple *tuple,
+				const struct nf_conntrack_l4proto *l4proto)
 {
 	int ret = 0;
 	struct nlattr *nest_parms;
@@ -86,7 +86,7 @@  static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
 
 static int ctnetlink_dump_tuples_ip(struct sk_buff *skb,
 				    const struct nf_conntrack_tuple *tuple,
-				    struct nf_conntrack_l3proto *l3proto)
+				    const struct nf_conntrack_l3proto *l3proto)
 {
 	int ret = 0;
 	struct nlattr *nest_parms;
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
index 1dcad22..390799a 100644
--- a/net/netfilter/nf_conntrack_proto.c
+++ b/net/netfilter/nf_conntrack_proto.c
@@ -188,7 +188,7 @@  struct nf_conntrack_l4proto *
 }
 EXPORT_SYMBOL_GPL(nf_ct_l4proto_find_get);
 
-void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p)
+void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p)
 {
 	module_put(p->me);
 }
@@ -242,7 +242,7 @@  int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
 extern unsigned int nf_conntrack_default_on;
 
 int nf_ct_l3proto_pernet_register(struct net *net,
-				  struct nf_conntrack_l3proto *proto)
+				  const struct nf_conntrack_l3proto *proto)
 {
 	if (nf_conntrack_default_on == 0)
 		return 0;
@@ -271,7 +271,7 @@  void nf_ct_l3proto_unregister(struct nf_conntrack_l3proto *proto)
 EXPORT_SYMBOL_GPL(nf_ct_l3proto_unregister);
 
 void nf_ct_l3proto_pernet_unregister(struct net *net,
-				     struct nf_conntrack_l3proto *proto)
+				     const struct nf_conntrack_l3proto *proto)
 {
 	/*
 	 * nf_conntrack_default_on *might* have registered hooks.
@@ -286,7 +286,7 @@  void nf_ct_l3proto_pernet_unregister(struct net *net,
 EXPORT_SYMBOL_GPL(nf_ct_l3proto_pernet_unregister);
 
 static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
-					      struct nf_conntrack_l4proto *l4proto)
+				const struct nf_conntrack_l4proto *l4proto)
 {
 	if (l4proto->get_net_proto) {
 		/* statically built-in protocols use static per-net */
@@ -301,7 +301,7 @@  static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
 static
 int nf_ct_l4proto_register_sysctl(struct net *net,
 				  struct nf_proto_net *pn,
-				  struct nf_conntrack_l4proto *l4proto)
+				  const struct nf_conntrack_l4proto *l4proto)
 {
 	int err = 0;
 
@@ -325,7 +325,7 @@  int nf_ct_l4proto_register_sysctl(struct net *net,
 static
 void nf_ct_l4proto_unregister_sysctl(struct net *net,
 				     struct nf_proto_net *pn,
-				     struct nf_conntrack_l4proto *l4proto)
+				     const struct nf_conntrack_l4proto *l4proto)
 {
 #ifdef CONFIG_SYSCTL
 	if (pn->ctl_table_header != NULL)
@@ -395,7 +395,7 @@  int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *l4proto)
 EXPORT_SYMBOL_GPL(nf_ct_l4proto_register_one);
 
 int nf_ct_l4proto_pernet_register_one(struct net *net,
-				      struct nf_conntrack_l4proto *l4proto)
+				const struct nf_conntrack_l4proto *l4proto)
 {
 	int ret = 0;
 	struct nf_proto_net *pn = NULL;
@@ -420,7 +420,7 @@  int nf_ct_l4proto_pernet_register_one(struct net *net,
 }
 EXPORT_SYMBOL_GPL(nf_ct_l4proto_pernet_register_one);
 
-static void __nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
+static void __nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
 
 {
 	BUG_ON(l4proto->l3proto >= ARRAY_SIZE(nf_ct_protos));
@@ -433,7 +433,7 @@  static void __nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
 			   &nf_conntrack_l4proto_generic);
 }
 
-void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
+void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *l4proto)
 {
 	mutex_lock(&nf_ct_proto_mutex);
 	__nf_ct_l4proto_unregister_one(l4proto);
@@ -444,7 +444,7 @@  void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *l4proto)
 EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister_one);
 
 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
-					 struct nf_conntrack_l4proto *l4proto)
+				const struct nf_conntrack_l4proto *l4proto)
 {
 	struct nf_proto_net *pn = nf_ct_l4proto_net(net, l4proto);
 
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index 400e9ae..ca760b9 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/net/netfilter/nfnetlink_cttimeout.c
@@ -401,7 +401,7 @@  static int cttimeout_default_set(struct net *net, struct sock *ctnl,
 static int
 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
 			    u32 seq, u32 type, int event,
-			    struct nf_conntrack_l4proto *l4proto)
+			    const struct nf_conntrack_l4proto *l4proto)
 {
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;