netfilter: nfnetlink_acct: Adding quota support to accounting framework
nfacct objects already support accounting at the byte and packet
level. As such it is a natural extension to add the possiblity to
define a ceiling limit for both metrics.
All the support for quotas itself is added to nfnetlink acctounting
framework to stay coherent with current accounting object management.
Quota limit checks are implemented in xt_nfacct filter where
statistic collection is already done.
Pablo Neira Ayuso has also contributed to this feature.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
index c7b6d46..70e86bb 100644
--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -32,18 +32,24 @@
struct nf_acct {
atomic64_t pkts;
atomic64_t bytes;
+ unsigned long flags;
struct list_head head;
atomic_t refcnt;
char name[NFACCT_NAME_MAX];
struct rcu_head rcu_head;
+ char data[0];
};
+#define NFACCT_F_QUOTA (NFACCT_F_QUOTA_PKTS | NFACCT_F_QUOTA_BYTES)
+
static int
nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
const struct nlmsghdr *nlh, const struct nlattr * const tb[])
{
struct nf_acct *nfacct, *matching = NULL;
char *acct_name;
+ unsigned int size = 0;
+ u32 flags = 0;
if (!tb[NFACCT_NAME])
return -EINVAL;
@@ -68,15 +74,39 @@
/* reset counters if you request a replacement. */
atomic64_set(&matching->pkts, 0);
atomic64_set(&matching->bytes, 0);
+ smp_mb__before_clear_bit();
+ /* reset overquota flag if quota is enabled. */
+ if ((matching->flags & NFACCT_F_QUOTA))
+ clear_bit(NFACCT_F_OVERQUOTA, &matching->flags);
return 0;
}
return -EBUSY;
}
nfacct = kzalloc(sizeof(struct nf_acct), GFP_KERNEL);
+ if (tb[NFACCT_FLAGS]) {
+ flags = ntohl(nla_get_be32(tb[NFACCT_FLAGS]));
+ if (flags & ~NFACCT_F_QUOTA)
+ return -EOPNOTSUPP;
+ if ((flags & NFACCT_F_QUOTA) == NFACCT_F_QUOTA)
+ return -EINVAL;
+ if (flags & NFACCT_F_OVERQUOTA)
+ return -EINVAL;
+
+ size += sizeof(u64);
+ }
+
+ nfacct = kzalloc(sizeof(struct nf_acct) + size, GFP_KERNEL);
if (nfacct == NULL)
return -ENOMEM;
+ if (flags & NFACCT_F_QUOTA) {
+ u64 *quota = (u64 *)nfacct->data;
+
+ *quota = be64_to_cpu(nla_get_be64(tb[NFACCT_QUOTA]));
+ nfacct->flags = flags;
+ }
+
strncpy(nfacct->name, nla_data(tb[NFACCT_NAME]), NFACCT_NAME_MAX);
if (tb[NFACCT_BYTES]) {
@@ -117,6 +147,9 @@
if (type == NFNL_MSG_ACCT_GET_CTRZERO) {
pkts = atomic64_xchg(&acct->pkts, 0);
bytes = atomic64_xchg(&acct->bytes, 0);
+ smp_mb__before_clear_bit();
+ if (acct->flags & NFACCT_F_QUOTA)
+ clear_bit(NFACCT_F_OVERQUOTA, &acct->flags);
} else {
pkts = atomic64_read(&acct->pkts);
bytes = atomic64_read(&acct->bytes);
@@ -125,7 +158,13 @@
nla_put_be64(skb, NFACCT_BYTES, cpu_to_be64(bytes)) ||
nla_put_be32(skb, NFACCT_USE, htonl(atomic_read(&acct->refcnt))))
goto nla_put_failure;
+ if (acct->flags & NFACCT_F_QUOTA) {
+ u64 *quota = (u64 *)acct->data;
+ if (nla_put_be32(skb, NFACCT_FLAGS, htonl(acct->flags)) ||
+ nla_put_be64(skb, NFACCT_QUOTA, cpu_to_be64(*quota)))
+ goto nla_put_failure;
+ }
nlmsg_end(skb, nlh);
return skb->len;
@@ -270,6 +309,8 @@
[NFACCT_NAME] = { .type = NLA_NUL_STRING, .len = NFACCT_NAME_MAX-1 },
[NFACCT_BYTES] = { .type = NLA_U64 },
[NFACCT_PKTS] = { .type = NLA_U64 },
+ [NFACCT_FLAGS] = { .type = NLA_U32 },
+ [NFACCT_QUOTA] = { .type = NLA_U64 },
};
static const struct nfnl_callback nfnl_acct_cb[NFNL_MSG_ACCT_MAX] = {
@@ -336,6 +377,50 @@
}
EXPORT_SYMBOL_GPL(nfnl_acct_update);
+static void nfnl_overquota_report(struct nf_acct *nfacct)
+{
+ int ret;
+ struct sk_buff *skb;
+
+ skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+ if (skb == NULL)
+ return;
+
+ ret = nfnl_acct_fill_info(skb, 0, 0, NFNL_MSG_ACCT_OVERQUOTA, 0,
+ nfacct);
+ if (ret <= 0) {
+ kfree_skb(skb);
+ return;
+ }
+ netlink_broadcast(init_net.nfnl, skb, 0, NFNLGRP_ACCT_QUOTA,
+ GFP_ATOMIC);
+}
+
+int nfnl_acct_overquota(const struct sk_buff *skb, struct nf_acct *nfacct)
+{
+ u64 now;
+ u64 *quota;
+ int ret = NFACCT_UNDERQUOTA;
+
+ /* no place here if we don't have a quota */
+ if (!(nfacct->flags & NFACCT_F_QUOTA))
+ return NFACCT_NO_QUOTA;
+
+ quota = (u64 *)nfacct->data;
+ now = (nfacct->flags & NFACCT_F_QUOTA_PKTS) ?
+ atomic64_read(&nfacct->pkts) : atomic64_read(&nfacct->bytes);
+
+ ret = now > *quota;
+
+ if (now >= *quota &&
+ !test_and_set_bit(NFACCT_F_OVERQUOTA, &nfacct->flags)) {
+ nfnl_overquota_report(nfacct);
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(nfnl_acct_overquota);
+
static int __init nfnl_acct_init(void)
{
int ret;