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1 files changed, 316 insertions, 0 deletions

diff --git a/kernel/linux2.5/net/bridge/netfilter/ebt_vlan.c b/kernel/linux2.5/net/bridge/netfilter/ebt_vlan.c
new file mode 100644
index 0000000..6f8915f
--- /dev/null
+++ b/kernel/linux2.5/net/bridge/netfilter/ebt_vlan.c
@@ -0,0 +1,316 @@
+/*
+ * Description: EBTables 802.1Q match extension kernelspace module.
+ * Authors: Nick Fedchik <nick@fedchik.org.ua>
+ *          Bart De Schuymer <bart.de.schuymer@pandora.be>
+ *    
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *  
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/module.h>
+#include <linux/netfilter_bridge/ebtables.h>
+#include <linux/netfilter_bridge/ebt_vlan.h>
+
+static unsigned char debug;
+#define MODULE_VERSION "0.4 (" __DATE__ " " __TIME__ ")"
+
+MODULE_PARM (debug, "0-1b");
+MODULE_PARM_DESC (debug, "debug=1 is turn on debug messages");
+MODULE_AUTHOR ("Nick Fedchik <nick@fedchik.org.ua>");
+MODULE_DESCRIPTION ("802.1Q match module (ebtables extension), v"
+		    MODULE_VERSION);
+MODULE_LICENSE ("GPL");
+
+
+#define DEBUG_MSG(...) if (debug) printk (KERN_DEBUG __FILE__ ":" __VA_ARGS__)
+#define INV_FLAG(_inv_flag_) (info->invflags & _inv_flag_) ? "!" : ""
+#define GET_BITMASK(_BIT_MASK_) info->bitmask & _BIT_MASK_
+#define SET_BITMASK(_BIT_MASK_) info->bitmask |= _BIT_MASK_
+#define EXIT_ON_MISMATCH(_MATCH_,_MASK_) if (!((info->_MATCH_ == _MATCH_)^!!(info->invflags & _MASK_))) return 1;
+
+/*
+ * Function description: ebt_filter_vlan() is main engine for 
+ * checking passed 802.1Q frame according to 
+ * the passed extension parameters (in the *data buffer)
+ * ebt_filter_vlan() is called after successfull check the rule params
+ * by ebt_check_vlan() function.
+ * Parameters:
+ * const struct sk_buff *skb - pointer to passed ethernet frame buffer
+ * const void *data - pointer to passed extension parameters
+ * unsigned int datalen - length of passed *data buffer
+ * const struct net_device *in  -
+ * const struct net_device *out -
+ * const struct ebt_counter *c -
+ * Returned values:
+ * 0 - ok (all rule params matched)
+ * 1 - miss (rule params not acceptable to the parsed frame)
+ */
+static int
+ebt_filter_vlan (const struct sk_buff *skb,
+		 const struct net_device *in,
+		 const struct net_device *out,
+		 const void *data,
+		 unsigned int datalen)
+{
+	struct ebt_vlan_info *info = (struct ebt_vlan_info *) data;	/* userspace data */
+	struct vlan_ethhdr *frame = (struct vlan_ethhdr *) skb->mac.raw;	/* Passed tagged frame */
+
+	unsigned short TCI;	/* Whole TCI, given from parsed frame */
+	unsigned short id;	/* VLAN ID, given from frame TCI */
+	unsigned char prio;	/* user_priority, given from frame TCI */
+	unsigned short encap;	/* VLAN encapsulated Type/Length field, given from orig frame */
+
+	/*
+	 * Tag Control Information (TCI) consists of the following elements:
+	 * - User_priority. This field allows the tagged frame to carry user_priority
+	 * information across Bridged LANs in which individual LAN segments may be unable to signal
+	 * priority information (e.g., 802.3/Ethernet segments). 
+	 * The user_priority field is three bits in length, 
+	 * interpreted as a binary number. The user_priority is therefore
+	 * capable of representing eight priority levels, 0 through 7. 
+	 * The use and interpretation of this field is defined in ISO/IEC 15802-3.
+	 * - Canonical Format Indicator (CFI). This field is used,
+	 * in 802.3/Ethernet, to signal the presence or absence
+	 * of a RIF field, and, in combination with the Non-canonical Format Indicator (NCFI) carried
+	 * in the RIF, to signal the bit order of address information carried in the encapsulated
+	 * frame. The Canonical Format Indicator (CFI) is a single bit flag value.
+	 * - VLAN Identifier (VID). This field uniquely identifies the VLAN to
+	 * which the frame belongs. The twelve-bit VLAN Identifier (VID) field 
+	 * uniquely identify the VLAN to which the frame belongs. 
+	 * The VID is encoded as an unsigned binary number. 
+	 */
+	TCI = ntohs (frame->h_vlan_TCI);
+	id = TCI & 0xFFF;
+	prio = TCI >> 13;
+	encap = frame->h_vlan_encapsulated_proto;
+
+	/*
+	 * First step is to check is null VLAN ID present
+	 * in the parsed frame
+	 */
+	if (!(id)) {
+		/*
+		 * Checking VLAN Identifier (VID)
+		 */
+		if (GET_BITMASK (EBT_VLAN_ID)) {	/* Is VLAN ID parsed? */
+			EXIT_ON_MISMATCH (id, EBT_VLAN_ID);
+			DEBUG_MSG
+			    ("matched rule id=%s%d for frame id=%d\n",
+			     INV_FLAG (EBT_VLAN_ID), info->id, id);
+		}
+	} else {
+		/*
+		 * Checking user_priority
+		 */
+		if (GET_BITMASK (EBT_VLAN_PRIO)) {	/* Is VLAN user_priority parsed? */
+			EXIT_ON_MISMATCH (prio, EBT_VLAN_PRIO);
+			DEBUG_MSG
+			    ("matched rule prio=%s%d for frame prio=%d\n",
+			     INV_FLAG (EBT_VLAN_PRIO), info->prio,
+			     prio);
+		}
+	}
+	/*
+	 * Checking Encapsulated Proto (Length/Type) field
+	 */
+	if (GET_BITMASK (EBT_VLAN_ENCAP)) {	/* Is VLAN Encap parsed? */
+		EXIT_ON_MISMATCH (encap, EBT_VLAN_ENCAP);
+		DEBUG_MSG ("matched encap=%s%2.4X for frame encap=%2.4X\n",
+			   INV_FLAG (EBT_VLAN_ENCAP),
+			   ntohs (info->encap), ntohs (encap));
+	}
+	/*
+	 * All possible extension parameters was parsed.
+	 * If rule never returned by missmatch, then all ok.
+	 */
+	return 0;
+}
+
+/*
+ * Function description: ebt_vlan_check() is called when userspace 
+ * delivers the table to the kernel, 
+ * and to check that userspace doesn't give a bad table.
+ * Parameters:
+ * const char *tablename - table name string
+ * unsigned int hooknr - hook number
+ * const struct ebt_entry *e - ebtables entry basic set
+ * const void *data - pointer to passed extension parameters
+ * unsigned int datalen - length of passed *data buffer
+ * Returned values:
+ * 0 - ok (all delivered rule params are correct)
+ * 1 - miss (rule params is out of range, invalid, incompatible, etc.)
+ */
+static int
+ebt_check_vlan (const char *tablename,
+		unsigned int hooknr,
+		const struct ebt_entry *e, void *data,
+		unsigned int datalen)
+{
+	struct ebt_vlan_info *info = (struct ebt_vlan_info *) data;
+
+	/*
+	 * Parameters buffer overflow check 
+	 */
+	if (datalen != sizeof (struct ebt_vlan_info)) {
+		DEBUG_MSG
+		    ("params size %d is not eq to ebt_vlan_info (%d)\n",
+		     datalen, sizeof (struct ebt_vlan_info));
+		return -EINVAL;
+	}
+
+	/*
+	 * Is it 802.1Q frame checked?
+	 */
+	if (e->ethproto != __constant_htons (ETH_P_8021Q)) {
+		DEBUG_MSG ("passed entry proto %2.4X is not 802.1Q (8100)\n",
+			   (unsigned short) ntohs (e->ethproto));
+		return -EINVAL;
+	}
+
+	/*
+	 * Check for bitmask range 
+	 * True if even one bit is out of mask
+	 */
+	if (info->bitmask & ~EBT_VLAN_MASK) {
+		DEBUG_MSG ("bitmask %2X is out of mask (%2X)\n",
+			   info->bitmask, EBT_VLAN_MASK);
+		return -EINVAL;
+	}
+
+	/*
+	 * Check for inversion flags range 
+	 */
+	if (info->invflags & ~EBT_VLAN_MASK) {
+		DEBUG_MSG ("inversion flags %2X is out of mask (%2X)\n",
+			   info->invflags, EBT_VLAN_MASK);
+		return -EINVAL;
+	}
+
+	/*
+	 * Reserved VLAN ID (VID) values
+	 * -----------------------------
+	 * 0 - The null VLAN ID. Indicates that the tag header contains only user_priority information;
+	 * no VLAN identifier is present in the frame. This VID value shall not be
+	 * configured as a PVID, configured in any Filtering Database entry, or used in any
+	 * Management operation.
+	 * 
+	 * 1 - The default Port VID (PVID) value used for classifying frames on ingress through a Bridge
+	 * Port. The PVID value can be changed by management on a per-Port basis.
+	 * 
+	 * 0x0FFF - Reserved for implementation use. This VID value shall not be configured as a
+	 * PVID or transmitted in a tag header.
+	 * 
+	 * The remaining values of VID are available for general use as VLAN identifiers.
+	 * A Bridge may implement the ability to support less than the full range of VID values; 
+	 * i.e., for a given implementation,
+	 * an upper limit, N, is defined for the VID values supported, where N is less than or equal to 4094.
+	 * All implementations shall support the use of all VID values in the range 0 through their defined maximum
+	 * VID, N.
+	 * 
+	 * For Linux, N = 4094.
+	 */
+	if (GET_BITMASK (EBT_VLAN_ID)) {	/* when vlan-id param was spec-ed */
+		if (!!info->id) {	/* if id!=0 => check vid range */
+			if (info->id > 4094) {	/* check if id > than (0x0FFE) */
+				DEBUG_MSG
+				    ("vlan id %d is out of range (1-4094)\n",
+				     info->id);
+				return -EINVAL;
+			}
+			/*
+			 * Note: This is valid VLAN-tagged frame point.
+			 * Any value of user_priority are acceptable, but could be ignored
+			 * according to 802.1Q Std.
+			 */
+		} else {
+			/*
+			 * if id=0 (null VLAN ID)  => Check for user_priority range 
+			 */
+			if (GET_BITMASK (EBT_VLAN_PRIO)) {
+				if ((unsigned char) info->prio > 7) {
+					DEBUG_MSG
+					    ("prio %d is out of range (0-7)\n",
+					     info->prio);
+					return -EINVAL;
+				}
+			}
+			/*
+			 * Note2: This is valid priority-tagged frame point
+			 * with null VID field.
+			 */
+		}
+	} else {		/* VLAN Id not set */
+		if (GET_BITMASK (EBT_VLAN_PRIO)) {	/* But user_priority is set - abnormal! */
+			info->id = 0;	/* Set null VID (case for Priority-tagged frames) */
+			SET_BITMASK (EBT_VLAN_ID);	/* and set id flag */
+		}
+	}
+	/*
+	 * Check for encapsulated proto range - it is possible to be any value for u_short range.
+	 * When relaying a tagged frame between 802.3/Ethernet MACs, 
+	 * a Bridge may adjust the padding field such that
+	 * the minimum size of a transmitted tagged frame is 68 octets (7.2).
+	 * if_ether.h:  ETH_ZLEN        60   -  Min. octets in frame sans FCS
+	 */
+	if (GET_BITMASK (EBT_VLAN_ENCAP)) {
+		if ((unsigned short) ntohs (info->encap) < ETH_ZLEN) {
+			DEBUG_MSG
+			    ("encap packet length %d is less than minimal %d\n",
+			     ntohs (info->encap), ETH_ZLEN);
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * Otherwise is all correct 
+	 */
+	DEBUG_MSG ("802.1Q tagged frame checked (%s table, %d hook)\n",
+		   tablename, hooknr);
+	return 0;
+}
+
+static struct ebt_match filter_vlan = {
+	{NULL, NULL},
+	EBT_VLAN_MATCH,
+	ebt_filter_vlan,
+	ebt_check_vlan,
+	NULL,
+	THIS_MODULE
+};
+
+/*
+ * Module initialization function.
+ * Called when module is loaded to kernelspace
+ */
+static int __init init (void)
+{
+	DEBUG_MSG ("ebtables 802.1Q extension module v"
+		   MODULE_VERSION "\n");
+	DEBUG_MSG ("module debug=%d\n", !!debug);
+	return ebt_register_match (&filter_vlan);
+}
+
+/*
+ * Module "finalization" function
+ * Called when download module from kernelspace
+ */
+static void __exit fini (void)
+{
+	ebt_unregister_match (&filter_vlan);
+}
+
+module_init (init);
+module_exit (fini);