[PATCH 1/1 v2] netfilter: constify nf_conntrack_l3/4proto parameters

From: Julia Lawall
Date: Sun Jul 30 2017 - 16:04:37 EST


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@xxxxxxx>

---

v2: Added consideration of array parameters. This adds transformation of
nf_ct_l4proto_pernet_register and nf_ct_l4proto_pernet_unregister.

This patch also adds transformation of ctnl_timeout_parse_policy that was
somehow overlooked previously.

include/net/netfilter/nf_conntrack_l3proto.h | 6 ++---
include/net/netfilter/nf_conntrack_l4proto.h | 14 ++++++------
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 | 30 +++++++++++++--------------
net/netfilter/nfnetlink_cttimeout.c | 5 ++--
7 files changed, 36 insertions(+), 35 deletions(-)

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..c86e946 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -125,23 +125,23 @@ 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[],
+ struct nf_conntrack_l4proto * const proto[],
unsigned int num_proto);
void nf_ct_l4proto_pernet_unregister(struct net *net,
- struct nf_conntrack_l4proto *proto[],
- unsigned int num_proto);
+ struct nf_conntrack_l4proto * const proto[],
+ unsigned int num_proto);

/* 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..62a2923 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;

@@ -324,8 +324,8 @@ 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)
+ struct nf_proto_net *pn,
+ 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);

@@ -478,8 +478,8 @@ int nf_ct_l4proto_register(struct nf_conntrack_l4proto *l4proto[],
EXPORT_SYMBOL_GPL(nf_ct_l4proto_register);

int nf_ct_l4proto_pernet_register(struct net *net,
- struct nf_conntrack_l4proto *l4proto[],
- unsigned int num_proto)
+ struct nf_conntrack_l4proto * const l4proto[],
+ unsigned int num_proto)
{
int ret = -EINVAL;
unsigned int i;
@@ -514,8 +514,8 @@ void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *l4proto[],
EXPORT_SYMBOL_GPL(nf_ct_l4proto_unregister);

void nf_ct_l4proto_pernet_unregister(struct net *net,
- struct nf_conntrack_l4proto *l4proto[],
- unsigned int num_proto)
+ struct nf_conntrack_l4proto * const l4proto[],
+ unsigned int num_proto)
{
while (num_proto-- != 0)
nf_ct_l4proto_pernet_unregister_one(net, l4proto[num_proto]);
diff --git a/net/netfilter/nfnetlink_cttimeout.c b/net/netfilter/nfnetlink_cttimeout.c
index 400e9ae..707a0d8 100644
--- a/net/netfilter/nfnetlink_cttimeout.c
+++ b/net/netfilter/nfnetlink_cttimeout.c
@@ -47,7 +47,8 @@
};

static int
-ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
+ctnl_timeout_parse_policy(void *timeouts,
+ const struct nf_conntrack_l4proto *l4proto,
struct net *net, const struct nlattr *attr)
{
int ret = 0;
@@ -401,7 +402,7 @@ 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;