1 files changed, 161 insertions, 51 deletions

diff --git a/kernel/linux2.5/net/bridge/netfilter/ebt_among.c b/kernel/linux2.5/net/bridge/netfilter/ebt_among.c
index 1ae9ad4..e4b2268 100644
--- a/kernel/linux2.5/net/bridge/netfilter/ebt_among.c
+++ b/kernel/linux2.5/net/bridge/netfilter/ebt_among.c
@@ -10,100 +10,209 @@
 
 #include <linux/netfilter_bridge/ebtables.h>
 #include <linux/netfilter_bridge/ebt_among.h>
+#include <linux/ip.h>
+#include <linux/if_arp.h>
 #include <linux/module.h>
 
-static int ebt_mac_wormhash_contains(const struct ebt_mac_wormhash *wh, const char *mac)
+/*
+#define DEBUG
+*/
+
+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];
-	while (offset) {
-		p = (const struct ebt_mac_wormhash_tuple*)(base + offset);
-		if (cmp[1] == p->cmp[1] && cmp[0] == p->cmp[0])
-			return 1;
-		offset = p->next_ofs;
+	int key = (const unsigned char) mac[5];
+	memcpy(((char *) cmp) + 2, mac, 6);
+	start = wh->table[key];
+	limit = wh->table[key + 1];
+	if (ip) {
+		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;
+				}
+			}
+		}
+	} else {
+		for (i = start; i < limit; i++) {
+			p = &wh->pool[i];
+			if (cmp[1] == p->cmp[1] && cmp[0] == p->cmp[0]) {
+				return 1;
+			}
+		}
 	}
 	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)
-				return -1;
-			if (p > wh->pool + 256 - 1)
-				return -2;
-			count++;
-			if (count > 1000)
-				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)
+{
+	if (skb->mac.ethernet->h_proto == __constant_htons(ETH_P_IP)) {
+		*addr = skb->nh.iph->daddr;
+		return 1;
+	}
+	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));
+
+		/* Make sure the packet is long enough. */
+		if ((((*skb).nh.raw) + arp_len) > (*skb).tail)
+			return 0;
+		/* 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));
+
+		return 2;
+	}
+	return 0;
+}
+
+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;
+		return 1;
+	}
+	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));
+
+		/* Make sure the packet is long enough. */
+		if ((((*skb).nh.raw) + arp_len) > (*skb).tail)
+			return 0;
+		/* 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));
+
+		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;
-	if (info->bitmask & EBT_AMONG_SRC) {
+	const struct ebt_mac_wormhash *wh_dst, *wh_src;
+	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;
-		if (!ebt_mac_wormhash_contains(&info->wh_src, smac))
-			return EBT_NOMATCH;
+		get_ip_src(skb, &sip);
+		if (!(info->bitmask & EBT_AMONG_SRC_NEG)) {
+			/* we match only if it contains */
+			if (!ebt_mac_wormhash_contains(wh_src, smac, sip)) {
+				return EBT_NOMATCH;
+			}
+		} else {
+			/* we match only if it DOES NOT contain */
+			if (ebt_mac_wormhash_contains(wh_src, smac, sip)) {
+				return EBT_NOMATCH;
+			}
+		}
 	}
 
-	if (info->bitmask & EBT_AMONG_DST) {
+	if (wh_dst) {
 		dmac = skb->mac.ethernet->h_dest;
-		if (!ebt_mac_wormhash_contains(&info->wh_dst, dmac))
-			return EBT_NOMATCH;
+		get_ip_dst(skb, &dip);
+		if (!(info->bitmask & EBT_AMONG_DST_NEG)) {
+			/* we match only if it contains */
+			if (!ebt_mac_wormhash_contains(wh_dst, dmac, dip)) {
+				return EBT_NOMATCH;
+			}
+		} else {
+			/* we match only if it DOES NOT contain */
+			if (ebt_mac_wormhash_contains(wh_dst, dmac, dip)) {
+				return EBT_NOMATCH;
+			}
+		}
 	}
 
 	return EBT_MATCH;
 }
 
 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(sizeof(struct ebt_among_info))) {
-		printk(KERN_WARNING "ebtables: among: wrong size\n");
+	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));
 		return -EINVAL;
 	}
-	if ((info->bitmask & EBT_AMONG_DST) && ebt_mac_wormhash_check_integrity(&info->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 ((info->bitmask & EBT_AMONG_SRC) && ebt_mac_wormhash_check_integrity(&info->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
 };
 
@@ -119,4 +228,5 @@ static void __exit fini(void)
 
 module_init(init);
 module_exit(fini);
+EXPORT_NO_SYMBOLS;
 MODULE_LICENSE("GPL");