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-rw-r--r--kernel/linux/net/bridge/netfilter/ebt_among.c143
1 files changed, 70 insertions, 73 deletions
diff --git a/kernel/linux/net/bridge/netfilter/ebt_among.c b/kernel/linux/net/bridge/netfilter/ebt_among.c
index b4f2aed..e4b2268 100644
--- a/kernel/linux/net/bridge/netfilter/ebt_among.c
+++ b/kernel/linux/net/bridge/netfilter/ebt_among.c
@@ -14,76 +14,63 @@
#include <linux/if_arp.h>
#include <linux/module.h>
+/*
#define DEBUG
+*/
-static int ebt_mac_wormhash_contains(const struct ebt_mac_wormhash *wh, const char *mac, uint32_t ip)
+static int ebt_mac_wormhash_contains(const struct ebt_mac_wormhash *wh,
+ const char *mac, uint32_t ip)
{
/* You may be puzzled as to how this code works.
- * Some tricks were used, refer to include/linux/netfilter_bridge/ebt_among.h
+ * Some tricks were used, refer to
+ * include/linux/netfilter_bridge/ebt_among.h
* as there you can find a solution of this mystery.
*/
const struct ebt_mac_wormhash_tuple *p;
- int offset;
- const char *base = (const char*)wh;
+ int start, limit, i;
uint32_t cmp[2] = { 0, 0 };
- int key = (const unsigned char)mac[5];
- memcpy(((char*)cmp)+2, mac, 6);
- offset = wh->table[key];
+ int key = (const unsigned char) mac[5];
+ memcpy(((char *) cmp) + 2, mac, 6);
+ start = wh->table[key];
+ limit = wh->table[key + 1];
if (ip) {
- while (offset) {
- p = (const struct ebt_mac_wormhash_tuple*)(base + offset);
+ for (i = start; i < limit; i++) {
+ p = &wh->pool[i];
if (cmp[1] == p->cmp[1] && cmp[0] == p->cmp[0]) {
if (p->ip == 0 || p->ip == ip) {
return 1;
}
}
- offset = p->next_ofs;
}
- }
- else {
- while (offset) {
- p = (const struct ebt_mac_wormhash_tuple*)(base + offset);
+ } else {
+ for (i = start; i < limit; i++) {
+ p = &wh->pool[i];
if (cmp[1] == p->cmp[1] && cmp[0] == p->cmp[0]) {
return 1;
}
- offset = p->next_ofs;
}
}
return 0;
}
-static int ebt_mac_wormhash_check_integrity(const struct ebt_mac_wormhash *wh)
+static int ebt_mac_wormhash_check_integrity(const struct ebt_mac_wormhash
+ *wh)
{
- int i, count;
- const struct ebt_mac_wormhash_tuple *p;
- int offset;
- const char *base = (const char*)wh;
-
- count = 0;
- for (i=256; i--;) {
- offset = wh->table[i];
- while (offset) {
- p = (const struct ebt_mac_wormhash_tuple*)(base + offset);
- if (p < wh->pool) {
- printk(KERN_WARNING "ebtables: among: integrity: offset too low; 0x%08x\n", offset);
- return -1;
- }
- if (p > wh->pool + wh->poolsize - 1) {
- printk(KERN_WARNING "ebtables: among: integrity: offset too high; 0x%08x\n", offset);
- return -2;
- }
- count++;
- if (count > 1000) {
- printk(KERN_WARNING "ebtables: among: integrity: loop at %d\n", i);
- return -3;
- }
- offset = p->next_ofs;
- }
+ int i;
+ for (i=0; i<256; i++) {
+ if (wh->table[i] > wh->table[i + 1])
+ return -0x100 - i;
+ if (wh->table[i] < 0)
+ return -0x200 - i;
+ if (wh->table[i] > wh->poolsize)
+ return -0x300 - i;
}
+ if (wh->table[256] > wh->poolsize)
+ return -0xc00;
return 0;
}
-static int get_ip_dst(const struct sk_buff *skb, uint32_t *addr)
+static int get_ip_dst(const struct sk_buff *skb, uint32_t * addr)
{
if (skb->mac.ethernet->h_proto == __constant_htons(ETH_P_IP)) {
*addr = skb->nh.iph->daddr;
@@ -92,26 +79,26 @@ static int get_ip_dst(const struct sk_buff *skb, uint32_t *addr)
if (skb->mac.ethernet->h_proto == __constant_htons(ETH_P_ARP)) {
uint32_t arp_len = sizeof(struct arphdr) +
- (2 * (((*skb).nh.arph)->ar_hln)) +
- (2 * (((*skb).nh.arph)->ar_pln));
+ (2 * (((*skb).nh.arph)->ar_hln)) +
+ (2 * (((*skb).nh.arph)->ar_pln));
- // Make sure the packet is long enough.
+ /* Make sure the packet is long enough. */
if ((((*skb).nh.raw) + arp_len) > (*skb).tail)
return 0;
- // IPv4 addresses are always 4 bytes.
+ /* IPv4 addresses are always 4 bytes. */
if (((*skb).nh.arph)->ar_pln != sizeof(uint32_t))
return 0;
memcpy(addr, ((*skb).nh.raw) + sizeof(struct arphdr) +
- (2*(((*skb).nh.arph)->ar_hln)) +
- (((*skb).nh.arph)->ar_pln), sizeof(uint32_t));
-
+ (2 * (((*skb).nh.arph)->ar_hln)) +
+ (((*skb).nh.arph)->ar_pln), sizeof(uint32_t));
+
return 2;
}
return 0;
}
-static int get_ip_src(const struct sk_buff *skb, uint32_t *addr)
+static int get_ip_src(const struct sk_buff *skb, uint32_t * addr)
{
if (skb->mac.ethernet->h_proto == __constant_htons(ETH_P_IP)) {
*addr = skb->nh.iph->saddr;
@@ -120,36 +107,37 @@ static int get_ip_src(const struct sk_buff *skb, uint32_t *addr)
if (skb->mac.ethernet->h_proto == __constant_htons(ETH_P_ARP)) {
uint32_t arp_len = sizeof(struct arphdr) +
- (2 * (((*skb).nh.arph)->ar_hln)) +
- (2 * (((*skb).nh.arph)->ar_pln));
+ (2 * (((*skb).nh.arph)->ar_hln)) +
+ (2 * (((*skb).nh.arph)->ar_pln));
- // Make sure the packet is long enough.
+ /* Make sure the packet is long enough. */
if ((((*skb).nh.raw) + arp_len) > (*skb).tail)
return 0;
- // IPv4 addresses are always 4 bytes.
+ /* IPv4 addresses are always 4 bytes. */
if (((*skb).nh.arph)->ar_pln != sizeof(uint32_t))
return 0;
memcpy(addr, ((*skb).nh.raw) + sizeof(struct arphdr) +
- ((((*skb).nh.arph)->ar_hln)), sizeof(uint32_t));
-
+ ((((*skb).nh.arph)->ar_hln)), sizeof(uint32_t));
+
return 2;
}
return 0;
}
static int ebt_filter_among(const struct sk_buff *skb,
- const struct net_device *in, const struct net_device *out, const void *data,
- unsigned int datalen)
+ const struct net_device *in,
+ const struct net_device *out, const void *data,
+ unsigned int datalen)
{
struct ebt_among_info *info = (struct ebt_among_info *) data;
const char *dmac, *smac;
const struct ebt_mac_wormhash *wh_dst, *wh_src;
- uint32_t dip=0, sip=0;
+ uint32_t dip = 0, sip = 0;
wh_dst = ebt_among_wh_dst(info);
wh_src = ebt_among_wh_src(info);
-
+
if (wh_src) {
smac = skb->mac.ethernet->h_source;
get_ip_src(skb, &sip);
@@ -158,8 +146,7 @@ static int ebt_filter_among(const struct sk_buff *skb,
if (!ebt_mac_wormhash_contains(wh_src, smac, sip)) {
return EBT_NOMATCH;
}
- }
- else {
+ } else {
/* we match only if it DOES NOT contain */
if (ebt_mac_wormhash_contains(wh_src, smac, sip)) {
return EBT_NOMATCH;
@@ -175,8 +162,7 @@ static int ebt_filter_among(const struct sk_buff *skb,
if (!ebt_mac_wormhash_contains(wh_dst, dmac, dip)) {
return EBT_NOMATCH;
}
- }
- else {
+ } else {
/* we match only if it DOES NOT contain */
if (ebt_mac_wormhash_contains(wh_dst, dmac, dip)) {
return EBT_NOMATCH;
@@ -188,34 +174,45 @@ static int ebt_filter_among(const struct sk_buff *skb,
}
static int ebt_among_check(const char *tablename, unsigned int hookmask,
- const struct ebt_entry *e, void *data, unsigned int datalen)
+ const struct ebt_entry *e, void *data,
+ unsigned int datalen)
{
struct ebt_among_info *info = (struct ebt_among_info *) data;
int expected_length = sizeof(struct ebt_among_info);
const struct ebt_mac_wormhash *wh_dst, *wh_src;
+ int err;
wh_dst = ebt_among_wh_dst(info);
wh_src = ebt_among_wh_src(info);
expected_length += ebt_mac_wormhash_size(wh_dst);
expected_length += ebt_mac_wormhash_size(wh_src);
if (datalen < EBT_ALIGN(expected_length)) {
- printk(KERN_WARNING "ebtables: among: wrong size: %d against expected %d, rounded to %d\n", datalen, expected_length, EBT_ALIGN(expected_length));
+ printk(KERN_WARNING
+ "ebtables: among: wrong size: %d"
+ "against expected %d, rounded to %d\n",
+ datalen, expected_length,
+ EBT_ALIGN(expected_length));
return -EINVAL;
}
- if (wh_dst && ebt_mac_wormhash_check_integrity(wh_dst)) {
- printk(KERN_WARNING "ebtables: among: dst integrity fail\n");
+ if (wh_dst && (err = ebt_mac_wormhash_check_integrity(wh_dst))) {
+ printk(KERN_WARNING
+ "ebtables: among: dst integrity fail: %x\n", -err);
return -EINVAL;
}
- if (wh_src && ebt_mac_wormhash_check_integrity(wh_src)) {
- printk(KERN_WARNING "ebtables: among: src integrity fail\n");
+ if (wh_src && (err = ebt_mac_wormhash_check_integrity(wh_src))) {
+ printk(KERN_WARNING
+ "ebtables: among: src integrity fail: %x\n", -err);
return -EINVAL;
}
return 0;
}
-static struct ebt_match filter_among =
-{
- {NULL, NULL}, EBT_AMONG_MATCH, ebt_filter_among, ebt_among_check, NULL,
+static struct ebt_match filter_among = {
+ {NULL, NULL},
+ EBT_AMONG_MATCH,
+ ebt_filter_among,
+ ebt_among_check,
+ NULL,
THIS_MODULE
};