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netfilter: conntrack: compute l3proto nla size at compile time
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avoids a pointer and allows struct to be const later on.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Florian Westphal authored and Pablo Neira Ayuso committed Aug 24, 2017
1 parent eee6ebb commit 0d03510
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Showing 5 changed files with 28 additions and 30 deletions.
19 changes: 8 additions & 11 deletions include/net/netfilter/nf_conntrack_l3proto.h
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,9 @@ struct nf_conntrack_l3proto {
/* L3 Protocol Family number. ex) PF_INET */
u_int16_t l3proto;

/* size of tuple nlattr, fills a hole */
u16 nla_size;

/* Protocol name */
const char *name;

Expand Down Expand Up @@ -49,23 +52,17 @@ struct nf_conntrack_l3proto {
int (*get_l4proto)(const struct sk_buff *skb, unsigned int nhoff,
unsigned int *dataoff, u_int8_t *protonum);

#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
int (*tuple_to_nlattr)(struct sk_buff *skb,
const struct nf_conntrack_tuple *t);

/* Called when netns wants to use connection tracking */
int (*net_ns_get)(struct net *);
void (*net_ns_put)(struct net *);

/*
* Calculate size of tuple nlattr
*/
int (*nlattr_tuple_size)(void);

int (*nlattr_to_tuple)(struct nlattr *tb[],
struct nf_conntrack_tuple *t);
const struct nla_policy *nla_policy;
#endif

size_t nla_size;
/* Called when netns wants to use connection tracking */
int (*net_ns_get)(struct net *);
void (*net_ns_put)(struct net *);

/* Module (if any) which this is connected to. */
struct module *me;
Expand Down
13 changes: 7 additions & 6 deletions net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
Original file line number Diff line number Diff line change
Expand Up @@ -303,11 +303,6 @@ static int ipv4_nlattr_to_tuple(struct nlattr *tb[],

return 0;
}

static int ipv4_nlattr_tuple_size(void)
{
return nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1);
}
#endif

static struct nf_sockopt_ops so_getorigdst = {
Expand Down Expand Up @@ -365,9 +360,10 @@ struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
.get_l4proto = ipv4_get_l4proto,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.tuple_to_nlattr = ipv4_tuple_to_nlattr,
.nlattr_tuple_size = ipv4_nlattr_tuple_size,
.nlattr_to_tuple = ipv4_nlattr_to_tuple,
.nla_policy = ipv4_nla_policy,
.nla_size = NLA_ALIGN(NLA_HDRLEN + sizeof(u32)) + /* CTA_IP_V4_SRC */
NLA_ALIGN(NLA_HDRLEN + sizeof(u32)), /* CTA_IP_V4_DST */
#endif
.net_ns_get = ipv4_hooks_register,
.net_ns_put = ipv4_hooks_unregister,
Expand Down Expand Up @@ -421,6 +417,11 @@ static int __init nf_conntrack_l3proto_ipv4_init(void)

need_conntrack();

#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
if (WARN_ON(nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1) !=
nf_conntrack_l3proto_ipv4.nla_size))
return -EINVAL;
#endif
ret = nf_register_sockopt(&so_getorigdst);
if (ret < 0) {
pr_err("Unable to register netfilter socket option\n");
Expand Down
14 changes: 8 additions & 6 deletions net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
Original file line number Diff line number Diff line change
Expand Up @@ -308,11 +308,6 @@ static int ipv6_nlattr_to_tuple(struct nlattr *tb[],

return 0;
}

static int ipv6_nlattr_tuple_size(void)
{
return nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1);
}
#endif

static int ipv6_hooks_register(struct net *net)
Expand Down Expand Up @@ -360,9 +355,10 @@ struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
.get_l4proto = ipv6_get_l4proto,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.tuple_to_nlattr = ipv6_tuple_to_nlattr,
.nlattr_tuple_size = ipv6_nlattr_tuple_size,
.nlattr_to_tuple = ipv6_nlattr_to_tuple,
.nla_policy = ipv6_nla_policy,
.nla_size = NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])) +
NLA_ALIGN(NLA_HDRLEN + sizeof(u32[4])),
#endif
.net_ns_get = ipv6_hooks_register,
.net_ns_put = ipv6_hooks_unregister,
Expand Down Expand Up @@ -421,6 +417,12 @@ static int __init nf_conntrack_l3proto_ipv6_init(void)

need_conntrack();

#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
if (WARN_ON(nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1) !=
nf_conntrack_l3proto_ipv6.nla_size))
return -EINVAL;
#endif

ret = nf_register_sockopt(&so_getorigdst6);
if (ret < 0) {
pr_err("Unable to register netfilter socket option\n");
Expand Down
3 changes: 2 additions & 1 deletion net/netfilter/nf_conntrack_netlink.c
Original file line number Diff line number Diff line change
Expand Up @@ -540,7 +540,8 @@ static inline size_t ctnetlink_proto_size(const struct nf_conn *ct)
size_t len = 0;

l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
len += l3proto->nla_size;
len = l3proto->nla_size;
len *= 3u; /* ORIG, REPLY, MASTER */

l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
len += l4proto->nla_size;
Expand Down
9 changes: 3 additions & 6 deletions net/netfilter/nf_conntrack_proto.c
Original file line number Diff line number Diff line change
Expand Up @@ -214,10 +214,10 @@ int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)

if (proto->l3proto >= NFPROTO_NUMPROTO)
return -EBUSY;

if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size)
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
if (proto->tuple_to_nlattr && proto->nla_size == 0)
return -EINVAL;

#endif
mutex_lock(&nf_ct_proto_mutex);
old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
lockdep_is_held(&nf_ct_proto_mutex));
Expand All @@ -226,9 +226,6 @@ int nf_ct_l3proto_register(struct nf_conntrack_l3proto *proto)
goto out_unlock;
}

if (proto->nlattr_tuple_size)
proto->nla_size = 3 * proto->nlattr_tuple_size();

rcu_assign_pointer(nf_ct_l3protos[proto->l3proto], proto);

out_unlock:
Expand Down

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