netfilter: ctnetlink: cleanup message-size calculation

This patch cleans up the message calculation to make it similar
to rtnetlink, moreover, it removes unneeded verbose information.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 40 insertions, 62 deletions

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 5c14867dd440..58fde0e47b05 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -403,76 +403,55 @@ nla_put_failure:
 }
 
 #ifdef CONFIG_NF_CONNTRACK_EVENTS
-/*
- * The general structure of a ctnetlink event is
- *
- *  CTA_TUPLE_ORIG
- *    <l3/l4-proto-attributes>
- *  CTA_TUPLE_REPLY
- *    <l3/l4-proto-attributes>
- *  CTA_ID
- *  ...
- *  CTA_PROTOINFO
- *    <l4-proto-attributes>
- *  CTA_TUPLE_MASTER
- *    <l3/l4-proto-attributes>
- *
- * Therefore the formular is
- *
- *   size = sizeof(headers) + sizeof(generic_nlas) + 3 * sizeof(tuple_nlas)
- *              + sizeof(protoinfo_nlas)
- */
-static struct sk_buff *
-ctnetlink_alloc_skb(const struct nf_conntrack_tuple *tuple, gfp_t gfp)
+static inline size_t
+ctnetlink_proto_size(const struct nf_conn *ct)
 {
         struct nf_conntrack_l3proto *l3proto;
         struct nf_conntrack_l4proto *l4proto;
-        int len;
-
-#define NLA_TYPE_SIZE(type)             nla_total_size(sizeof(type))
-
-        /* proto independant part */
-        len = NLMSG_ALIGN(sizeof(struct nfgenmsg))
-                + 3 * nla_total_size(0)         /* CTA_TUPLE_ORIG|REPL|MASTER */
-                + 3 * nla_total_size(0)         /* CTA_TUPLE_IP */
-                + 3 * nla_total_size(0)         /* CTA_TUPLE_PROTO */
-                + 3 * NLA_TYPE_SIZE(u_int8_t)   /* CTA_PROTO_NUM */
-                + NLA_TYPE_SIZE(u_int32_t)      /* CTA_ID */
-                + NLA_TYPE_SIZE(u_int32_t)      /* CTA_STATUS */
+        size_t len = 0;
+
+        rcu_read_lock();
+        l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
+        len += l3proto->nla_size;
+
+        l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
+        len += l4proto->nla_size;
+        rcu_read_unlock();
+
+        return len;
+}
+
+static inline size_t
+ctnetlink_nlmsg_size(const struct nf_conn *ct)
+{
+        return NLMSG_ALIGN(sizeof(struct nfgenmsg))
+               + 3 * nla_total_size(0) /* CTA_TUPLE_ORIG|REPL|MASTER */
+               + 3 * nla_total_size(0) /* CTA_TUPLE_IP */
+               + 3 * nla_total_size(0) /* CTA_TUPLE_PROTO */
+               + 3 * nla_total_size(sizeof(u_int8_t)) /* CTA_PROTO_NUM */
+               + nla_total_size(sizeof(u_int32_t)) /* CTA_ID */
+               + nla_total_size(sizeof(u_int32_t)) /* CTA_STATUS */
 #ifdef CONFIG_NF_CT_ACCT
-                + 2 * nla_total_size(0)         /* CTA_COUNTERS_ORIG|REPL */
-                + 2 * NLA_TYPE_SIZE(uint64_t)   /* CTA_COUNTERS_PACKETS */
-                + 2 * NLA_TYPE_SIZE(uint64_t)   /* CTA_COUNTERS_BYTES */
+               + 2 * nla_total_size(0) /* CTA_COUNTERS_ORIG|REPL */
+               + 2 * nla_total_size(sizeof(uint64_t)) /* CTA_COUNTERS_PACKETS */
+               + 2 * nla_total_size(sizeof(uint64_t)) /* CTA_COUNTERS_BYTES */
 #endif
-                + NLA_TYPE_SIZE(u_int32_t)      /* CTA_TIMEOUT */
-                + nla_total_size(0)             /* CTA_PROTOINFO */
-                + nla_total_size(0)             /* CTA_HELP */
-                + nla_total_size(NF_CT_HELPER_NAME_LEN) /* CTA_HELP_NAME */
+               + nla_total_size(sizeof(u_int32_t)) /* CTA_TIMEOUT */
+               + nla_total_size(0) /* CTA_PROTOINFO */
+               + nla_total_size(0) /* CTA_HELP */
+               + nla_total_size(NF_CT_HELPER_NAME_LEN) /* CTA_HELP_NAME */
 #ifdef CONFIG_NF_CONNTRACK_SECMARK
-                + NLA_TYPE_SIZE(u_int32_t)      /* CTA_SECMARK */
+               + nla_total_size(sizeof(u_int32_t)) /* CTA_SECMARK */
 #endif
 #ifdef CONFIG_NF_NAT_NEEDED
-                + 2 * nla_total_size(0)         /* CTA_NAT_SEQ_ADJ_ORIG|REPL */
-                + 2 * NLA_TYPE_SIZE(u_int32_t)  /* CTA_NAT_SEQ_CORRECTION_POS */
-                + 2 * NLA_TYPE_SIZE(u_int32_t)  /* CTA_NAT_SEQ_CORRECTION_BEFORE */
-                + 2 * NLA_TYPE_SIZE(u_int32_t)  /* CTA_NAT_SEQ_CORRECTION_AFTER */
+               + 2 * nla_total_size(0) /* CTA_NAT_SEQ_ADJ_ORIG|REPL */
+               + 6 * nla_total_size(sizeof(u_int32_t)) /* CTA_NAT_SEQ_OFFSET */
 #endif
 #ifdef CONFIG_NF_CONNTRACK_MARK
-                + NLA_TYPE_SIZE(u_int32_t)      /* CTA_MARK */
+               + nla_total_size(sizeof(u_int32_t)) /* CTA_MARK */
 #endif
-                ;
-
-#undef NLA_TYPE_SIZE
-
-        rcu_read_lock();
-        l3proto = __nf_ct_l3proto_find(tuple->src.l3num);
-        len += l3proto->nla_size;
-
-        l4proto = __nf_ct_l4proto_find(tuple->src.l3num, tuple->dst.protonum);
-        len += l4proto->nla_size;
-        rcu_read_unlock();
-
-        return nlmsg_new(len, gfp);
+               + ctnetlink_proto_size(ct)
+               ;
 }
 
 static int ctnetlink_conntrack_event(struct notifier_block *this,
@@ -507,9 +486,8 @@ static int ctnetlink_conntrack_event(struct notifier_block *this,
         if (!item->report && !nfnetlink_has_listeners(group))
                 return NOTIFY_DONE;
 
-        skb = ctnetlink_alloc_skb(nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL),
-                                  GFP_ATOMIC);
-        if (!skb)
+        skb = nlmsg_new(ctnetlink_nlmsg_size(ct), GFP_ATOMIC);
+        if (skb == NULL)
                 goto errout;
 
         type |= NFNL_SUBSYS_CTNETLINK << 8;