From 0d03510038bda70b5a4a252e8216822e6ce0cbdb Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 12 Aug 2017 00:57:02 +0200 Subject: [PATCH] netfilter: conntrack: compute l3proto nla size at compile time avoids a pointer and allows struct to be const later on. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_l3proto.h | 19 ++++++++----------- .../netfilter/nf_conntrack_l3proto_ipv4.c | 13 +++++++------ .../netfilter/nf_conntrack_l3proto_ipv6.c | 14 ++++++++------ net/netfilter/nf_conntrack_netlink.c | 3 ++- net/netfilter/nf_conntrack_proto.c | 9 +++------ 5 files changed, 28 insertions(+), 30 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h index 1b8de164d744..6a27ffea7480 100644 --- a/include/net/netfilter/nf_conntrack_l3proto.h +++ b/include/net/netfilter/nf_conntrack_l3proto.h @@ -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; @@ -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; diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c index de5f0e6ddd1b..9fb8cb033d80 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c @@ -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 = { @@ -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, @@ -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"); diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c index ddef5ee9e0a8..6b4d59fd0214 100644 --- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -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) @@ -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, @@ -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"); diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index f4ca48817f66..b59a453a0fd8 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -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; diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index 27810cf816a6..85104a27cc89 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -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)); @@ -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: -- 2.20.1