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Diffstat (limited to 'net/netfilter/xt_hashlimit.c')
-rw-r--r--net/netfilter/xt_hashlimit.c132
1 files changed, 106 insertions, 26 deletions
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index d95f9c963cde..26a668a84aa2 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -171,8 +171,7 @@ dsthash_alloc_init(struct xt_hashlimit_htable *ht,
if (ht->cfg.max && ht->count >= ht->cfg.max) {
/* FIXME: do something. question is what.. */
- if (net_ratelimit())
- pr_err("max count of %u reached\n", ht->cfg.max);
+ net_err_ratelimited("max count of %u reached\n", ht->cfg.max);
ent = NULL;
} else
ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC);
@@ -388,9 +387,20 @@ static void htable_put(struct xt_hashlimit_htable *hinfo)
#define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
+/* in byte mode, the lowest possible rate is one packet/second.
+ * credit_cap is used as a counter that tells us how many times we can
+ * refill the "credits available" counter when it becomes empty.
+ */
+#define MAX_CPJ_BYTES (0xFFFFFFFF / HZ)
+#define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES)
+
+static u32 xt_hashlimit_len_to_chunks(u32 len)
+{
+ return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1;
+}
+
/* Precision saver. */
-static inline u_int32_t
-user2credits(u_int32_t user)
+static u32 user2credits(u32 user)
{
/* If multiplying would overflow... */
if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
@@ -400,12 +410,53 @@ user2credits(u_int32_t user)
return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE;
}
-static inline void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now)
+static u32 user2credits_byte(u32 user)
{
- dh->rateinfo.credit += (now - dh->rateinfo.prev) * CREDITS_PER_JIFFY;
- if (dh->rateinfo.credit > dh->rateinfo.credit_cap)
- dh->rateinfo.credit = dh->rateinfo.credit_cap;
+ u64 us = user;
+ us *= HZ * CREDITS_PER_JIFFY_BYTES;
+ return (u32) (us >> 32);
+}
+
+static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, u32 mode)
+{
+ unsigned long delta = now - dh->rateinfo.prev;
+ u32 cap;
+
+ if (delta == 0)
+ return;
+
dh->rateinfo.prev = now;
+
+ if (mode & XT_HASHLIMIT_BYTES) {
+ u32 tmp = dh->rateinfo.credit;
+ dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta;
+ cap = CREDITS_PER_JIFFY_BYTES * HZ;
+ if (tmp >= dh->rateinfo.credit) {/* overflow */
+ dh->rateinfo.credit = cap;
+ return;
+ }
+ } else {
+ dh->rateinfo.credit += delta * CREDITS_PER_JIFFY;
+ cap = dh->rateinfo.credit_cap;
+ }
+ if (dh->rateinfo.credit > cap)
+ dh->rateinfo.credit = cap;
+}
+
+static void rateinfo_init(struct dsthash_ent *dh,
+ struct xt_hashlimit_htable *hinfo)
+{
+ dh->rateinfo.prev = jiffies;
+ if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) {
+ dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ;
+ dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg);
+ dh->rateinfo.credit_cap = hinfo->cfg.burst;
+ } else {
+ dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
+ hinfo->cfg.burst);
+ dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
+ dh->rateinfo.credit_cap = dh->rateinfo.credit;
+ }
}
static inline __be32 maskl(__be32 a, unsigned int l)
@@ -511,6 +562,21 @@ hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo,
return 0;
}
+static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh)
+{
+ u64 tmp = xt_hashlimit_len_to_chunks(len);
+ tmp = tmp * dh->rateinfo.cost;
+
+ if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ))
+ tmp = CREDITS_PER_JIFFY_BYTES * HZ;
+
+ if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) {
+ dh->rateinfo.credit_cap--;
+ dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ;
+ }
+ return (u32) tmp;
+}
+
static bool
hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
@@ -519,6 +585,7 @@ hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
unsigned long now = jiffies;
struct dsthash_ent *dh;
struct dsthash_dst dst;
+ u32 cost;
if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0)
goto hotdrop;
@@ -532,21 +599,21 @@ hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
goto hotdrop;
}
dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire);
- dh->rateinfo.prev = jiffies;
- dh->rateinfo.credit = user2credits(hinfo->cfg.avg *
- hinfo->cfg.burst);
- dh->rateinfo.credit_cap = user2credits(hinfo->cfg.avg *
- hinfo->cfg.burst);
- dh->rateinfo.cost = user2credits(hinfo->cfg.avg);
+ rateinfo_init(dh, hinfo);
} else {
/* update expiration timeout */
dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire);
- rateinfo_recalc(dh, now);
+ rateinfo_recalc(dh, now, hinfo->cfg.mode);
}
- if (dh->rateinfo.credit >= dh->rateinfo.cost) {
+ if (info->cfg.mode & XT_HASHLIMIT_BYTES)
+ cost = hashlimit_byte_cost(skb->len, dh);
+ else
+ cost = dh->rateinfo.cost;
+
+ if (dh->rateinfo.credit >= cost) {
/* below the limit */
- dh->rateinfo.credit -= dh->rateinfo.cost;
+ dh->rateinfo.credit -= cost;
spin_unlock(&dh->lock);
rcu_read_unlock_bh();
return !(info->cfg.mode & XT_HASHLIMIT_INVERT);
@@ -568,14 +635,6 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par)
struct xt_hashlimit_mtinfo1 *info = par->matchinfo;
int ret;
- /* Check for overflow. */
- if (info->cfg.burst == 0 ||
- user2credits(info->cfg.avg * info->cfg.burst) <
- user2credits(info->cfg.avg)) {
- pr_info("overflow, try lower: %u/%u\n",
- info->cfg.avg, info->cfg.burst);
- return -ERANGE;
- }
if (info->cfg.gc_interval == 0 || info->cfg.expire == 0)
return -EINVAL;
if (info->name[sizeof(info->name)-1] != '\0')
@@ -588,6 +647,26 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par)
return -EINVAL;
}
+ if (info->cfg.mode & ~XT_HASHLIMIT_ALL) {
+ pr_info("Unknown mode mask %X, kernel too old?\n",
+ info->cfg.mode);
+ return -EINVAL;
+ }
+
+ /* Check for overflow. */
+ if (info->cfg.mode & XT_HASHLIMIT_BYTES) {
+ if (user2credits_byte(info->cfg.avg) == 0) {
+ pr_info("overflow, rate too high: %u\n", info->cfg.avg);
+ return -EINVAL;
+ }
+ } else if (info->cfg.burst == 0 ||
+ user2credits(info->cfg.avg * info->cfg.burst) <
+ user2credits(info->cfg.avg)) {
+ pr_info("overflow, try lower: %u/%u\n",
+ info->cfg.avg, info->cfg.burst);
+ return -ERANGE;
+ }
+
mutex_lock(&hashlimit_mutex);
info->hinfo = htable_find_get(net, info->name, par->family);
if (info->hinfo == NULL) {
@@ -680,10 +759,11 @@ static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family,
struct seq_file *s)
{
int res;
+ const struct xt_hashlimit_htable *ht = s->private;
spin_lock(&ent->lock);
/* recalculate to show accurate numbers */
- rateinfo_recalc(ent, jiffies);
+ rateinfo_recalc(ent, jiffies, ht->cfg.mode);
switch (family) {
case NFPROTO_IPV4:
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