diff options
| author | Holger Eitzenberger <holger@eitzenberger.org> | 2009-03-25 21:50:59 +0100 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2009-03-25 21:50:59 +0100 |
| commit | 2732c4e45bb67006fdc9ae6669be866762711ab5 (patch) | |
| tree | d9ab37014adad2709cbb0a198eb2c48921d62420 /net/netfilter | |
| parent | ea781f197d6a835cbb93a0bf88ee1696296ed8aa (diff) | |
netfilter: ctnetlink: allocate right-sized ctnetlink skb
Try to allocate a Netlink skb roughly the size of the actual
message, with the help from the l3 and l4 protocol helpers.
This is all to prevent a reallocation in netlink_trim() later.
The overhead of allocating the right-sized skb is rather small, with
ctnetlink_alloc_skb() actually being inlined away on my x86_64 box.
The size of the per-proto space is determined at registration time of
the protocol helper.
Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter')
| -rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 65 |
1 files changed, 64 insertions, 1 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 349bbefe551..03547c60f38 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -405,6 +405,69 @@ 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) +{ + 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_SPACE(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 */ + + 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 */ + + 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_TYPE_SIZE(u_int32_t) /* CTA_SECMARK */ + + 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 */ + + NLA_TYPE_SIZE(u_int32_t); /* CTA_MARK */ + +#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 alloc_skb(len, gfp); +} + static int ctnetlink_conntrack_event(struct notifier_block *this, unsigned long events, void *ptr) { @@ -438,7 +501,7 @@ static int ctnetlink_conntrack_event(struct notifier_block *this, if (!item->report && !nfnetlink_has_listeners(group)) return NOTIFY_DONE; - skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC); + skb = ctnetlink_alloc_skb(tuple(ct, IP_CT_DIR_ORIGINAL), GFP_ATOMIC); if (!skb) return NOTIFY_DONE; |