From d0dba7255b541f1651a88e75ebdb20dd45509c2f Mon Sep 17 00:00:00 2001 From: Holger Eitzenberger Date: Wed, 25 Mar 2009 18:24:48 +0100 Subject: [PATCH] netfilter: ctnetlink: add callbacks to the per-proto nlattrs There is added a single callback for the l3 proto helper. The two callbacks for the l4 protos are necessary because of the general structure of a ctnetlink event, which is in short: CTA_TUPLE_ORIG CTA_TUPLE_REPLY CTA_ID ... CTA_PROTOINFO CTA_TUPLE_MASTER Therefore the formular is size := sizeof(generic-nlas) + 3 * sizeof(tuple_nlas) + sizeof(protoinfo_nlas) Some of the NLAs are optional, e. g. CTA_TUPLE_MASTER, which is only set if it's an expected connection. But the number of optional NLAs is small enough to prevent netlink_trim() from reallocating if calculated properly. Signed-off-by: Holger Eitzenberger Signed-off-by: Patrick McHardy --- include/net/netfilter/nf_conntrack_l3proto.h | 7 +++++++ include/net/netfilter/nf_conntrack_l4proto.h | 6 ++++++ net/netfilter/nf_conntrack_proto.c | 16 ++++++++++++++++ 3 files changed, 29 insertions(+) diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h index 0378676c3dd8..9f99d36d5de9 100644 --- a/include/net/netfilter/nf_conntrack_l3proto.h +++ b/include/net/netfilter/nf_conntrack_l3proto.h @@ -53,10 +53,17 @@ struct nf_conntrack_l3proto int (*tuple_to_nlattr)(struct sk_buff *skb, const struct nf_conntrack_tuple *t); + /* + * 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; + size_t nla_size; + #ifdef CONFIG_SYSCTL struct ctl_table_header *ctl_table_header; struct ctl_path *ctl_table_path; diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h index b01070bf2f84..a120990b3b2b 100644 --- a/include/net/netfilter/nf_conntrack_l4proto.h +++ b/include/net/netfilter/nf_conntrack_l4proto.h @@ -64,16 +64,22 @@ struct nf_conntrack_l4proto /* convert protoinfo to nfnetink attributes */ int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla, const struct nf_conn *ct); + /* Calculate protoinfo nlattr size */ + int (*nlattr_size)(void); /* convert nfnetlink attributes to protoinfo */ int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct); int (*tuple_to_nlattr)(struct sk_buff *skb, const struct nf_conntrack_tuple *t); + /* Calculate tuple nlattr size */ + int (*nlattr_tuple_size)(void); int (*nlattr_to_tuple)(struct nlattr *tb[], struct nf_conntrack_tuple *t); const struct nla_policy *nla_policy; + size_t nla_size; + #ifdef CONFIG_SYSCTL struct ctl_table_header **ctl_table_header; struct ctl_table *ctl_table; diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index 9a62b4efa0e1..1a4568bf7ea5 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -167,6 +167,9 @@ int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) if (proto->l3proto >= AF_MAX) return -EBUSY; + if (proto->tuple_to_nlattr && !proto->nlattr_tuple_size) + return -EINVAL; + mutex_lock(&nf_ct_proto_mutex); if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) { ret = -EBUSY; @@ -177,6 +180,9 @@ int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto) if (ret < 0) 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: @@ -263,6 +269,10 @@ int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) if (l4proto->l3proto >= PF_MAX) return -EBUSY; + if ((l4proto->to_nlattr && !l4proto->nlattr_size) + || (l4proto->tuple_to_nlattr && !l4proto->nlattr_tuple_size)) + return -EINVAL; + mutex_lock(&nf_ct_proto_mutex); if (!nf_ct_protos[l4proto->l3proto]) { /* l3proto may be loaded latter. */ @@ -290,6 +300,12 @@ int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto) if (ret < 0) goto out_unlock; + l4proto->nla_size = 0; + if (l4proto->nlattr_size) + l4proto->nla_size += l4proto->nlattr_size(); + if (l4proto->nlattr_tuple_size) + l4proto->nla_size += 3 * l4proto->nlattr_tuple_size(); + rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto], l4proto); -- 2.20.1