xt_psd: move IPv4 state locking responsibility to caller

The former psd_match function is now < 72 lines.
This commit is contained in:
Florian Westphal
2012-08-17 14:31:57 +02:00
committed by Jan Engelhardt
parent 2ba833fe47
commit 0a97126f5b

View File

@@ -237,20 +237,16 @@ get_header_pointer4(const struct sk_buff *skb, unsigned int thoff, void *mem)
static bool
handle_packet4(const struct iphdr *iph, const struct tcphdr *tcph,
const struct xt_psd_info *psdinfo)
const struct xt_psd_info *psdinfo, unsigned int hash)
{
unsigned long now;
struct host *curr, *last = NULL, **head;
struct host4 *curr4;
int count = 0;
unsigned int hash;
now = jiffies;
hash = hashfunc(iph->saddr);
head = &state.hash[hash];
spin_lock(&state.lock);
/* Do we know this source address already? */
curr = *head;
while (curr != NULL) {
@@ -263,11 +259,9 @@ handle_packet4(const struct iphdr *iph, const struct tcphdr *tcph,
if (curr != NULL) {
/* We know this address, and the entry isn't too old. Update it. */
if (entry_is_recent(curr, psdinfo->delay_threshold, now)) {
if (is_portscan(curr, psdinfo, tcph, iph->protocol))
goto out_match;
goto out_no_match;
}
if (entry_is_recent(curr, psdinfo->delay_threshold, now))
return is_portscan(curr, psdinfo, tcph, iph->protocol);
/* We know this address, but the entry is outdated. Mark it unused, and
* remove from the hash table. We'll allocate a new entry instead since
* this one might get re-used too soon. */
@@ -279,7 +273,7 @@ handle_packet4(const struct iphdr *iph, const struct tcphdr *tcph,
/* We don't need an ACK from a new source address */
if (iph->protocol == IPPROTO_TCP && tcph->ack)
goto out_no_match;
return false;
/* Got too many source addresses with the same hash value? Then remove the
* oldest one from the hash table, so that they can't take too much of our
@@ -312,14 +306,7 @@ handle_packet4(const struct iphdr *iph, const struct tcphdr *tcph,
curr->weight = get_port_weight(psdinfo, tcph->dest);
curr->ports[0].number = tcph->dest;
curr->ports[0].proto = iph->protocol;
out_no_match:
spin_unlock(&state.lock);
return false;
out_match:
spin_unlock(&state.lock);
return true;
}
static bool
@@ -328,6 +315,8 @@ xt_psd_match(const struct sk_buff *pskb, struct xt_action_param *match)
struct iphdr *iph = ip_hdr(pskb);
struct tcphdr _tcph;
struct tcphdr *tcph;
bool matched;
unsigned int hash;
/* Parameters from userspace */
const struct xt_psd_info *psdinfo = match->matchinfo;
@@ -349,7 +338,12 @@ xt_psd_match(const struct sk_buff *pskb, struct xt_action_param *match)
if (tcph == NULL)
return false;
return handle_packet4(iph, tcph, psdinfo);
hash = hashfunc(iph->saddr);
spin_lock(&state.lock);
matched = handle_packet4(iph, tcph, psdinfo, hash);
spin_unlock(&state.lock);
return matched;
}
static int psd_mt_check(const struct xt_mtchk_param *par)