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Diffstat (limited to 'net/bridge/netfilter/ebt_vlan.c')
-rw-r--r--net/bridge/netfilter/ebt_vlan.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/net/bridge/netfilter/ebt_vlan.c b/net/bridge/netfilter/ebt_vlan.c
new file mode 100644
index 00000000000..db60d734908
--- /dev/null
+++ b/net/bridge/netfilter/ebt_vlan.c
@@ -0,0 +1,195 @@
+/*
+ * Description: EBTables 802.1Q match extension kernelspace module.
+ * Authors: Nick Fedchik <nick@fedchik.org.ua>
+ * Bart De Schuymer <bdschuym@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/moduleparam.h>
+#include <linux/netfilter_bridge/ebtables.h>
+#include <linux/netfilter_bridge/ebt_vlan.h>
+
+static int debug;
+#define MODULE_VERS "0.6"
+
+module_param(debug, int, 0);
+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_VERS);
+MODULE_LICENSE("GPL");
+
+
+#define DEBUG_MSG(args...) if (debug) printk (KERN_DEBUG "ebt_vlan: " 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 EBT_NOMATCH;}
+
+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;
+ struct vlan_hdr _frame, *fp;
+
+ 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 */
+ /* VLAN encapsulated Type/Length field, given from orig frame */
+ unsigned short encap;
+
+ fp = skb_header_pointer(skb, 0, sizeof(_frame), &_frame);
+ if (fp == NULL)
+ return EBT_NOMATCH;
+
+ /* Tag Control Information (TCI) consists of the following elements:
+ * - User_priority. The user_priority field is three bits in length,
+ * interpreted as a binary number.
+ * - Canonical Format Indicator (CFI). The Canonical Format Indicator
+ * (CFI) is a single bit flag value. Currently ignored.
+ * - VLAN Identifier (VID). The VID is encoded as
+ * an unsigned binary number. */
+ TCI = ntohs(fp->h_vlan_TCI);
+ id = TCI & VLAN_VID_MASK;
+ prio = (TCI >> 13) & 0x7;
+ encap = fp->h_vlan_encapsulated_proto;
+
+ /* Checking VLAN Identifier (VID) */
+ if (GET_BITMASK(EBT_VLAN_ID))
+ EXIT_ON_MISMATCH(id, EBT_VLAN_ID);
+
+ /* Checking user_priority */
+ if (GET_BITMASK(EBT_VLAN_PRIO))
+ EXIT_ON_MISMATCH(prio, EBT_VLAN_PRIO);
+
+ /* Checking Encapsulated Proto (Length/Type) field */
+ if (GET_BITMASK(EBT_VLAN_ENCAP))
+ EXIT_ON_MISMATCH(encap, EBT_VLAN_ENCAP);
+
+ return EBT_MATCH;
+}
+
+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 != EBT_ALIGN(sizeof(struct ebt_vlan_info))) {
+ DEBUG_MSG
+ ("passed size %d is not eq to ebt_vlan_info (%Zd)\n",
+ datalen, sizeof(struct ebt_vlan_info));
+ return -EINVAL;
+ }
+
+ /* Is it 802.1Q frame checked? */
+ if (e->ethproto != 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.
+ * 1 - The default Port VID (PVID)
+ * 0x0FFF - Reserved for implementation use.
+ * if_vlan.h: VLAN_GROUP_ARRAY_LEN 4096. */
+ if (GET_BITMASK(EBT_VLAN_ID)) {
+ if (!!info->id) { /* if id!=0 => check vid range */
+ if (info->id > VLAN_GROUP_ARRAY_LEN) {
+ DEBUG_MSG
+ ("id %d is out of range (1-4096)\n",
+ info->id);
+ return -EINVAL;
+ }
+ /* Note: This is valid VLAN-tagged frame point.
+ * Any value of user_priority are acceptable,
+ * but should be ignored according to 802.1Q Std.
+ * So we just drop the prio flag. */
+ info->bitmask &= ~EBT_VLAN_PRIO;
+ }
+ /* Else, id=0 (null VLAN ID) => user_priority range (any?) */
+ }
+
+ 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;
+ }
+ }
+ /* Check for encapsulated proto range - it is possible to be
+ * any value for u_short range.
+ * 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 frame length %d is less than minimal\n",
+ ntohs(info->encap));
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static struct ebt_match filter_vlan = {
+ .name = EBT_VLAN_MATCH,
+ .match = ebt_filter_vlan,
+ .check = ebt_check_vlan,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ DEBUG_MSG("ebtables 802.1Q extension module v"
+ MODULE_VERS "\n");
+ DEBUG_MSG("module debug=%d\n", !!debug);
+ return ebt_register_match(&filter_vlan);
+}
+
+static void __exit fini(void)
+{
+ ebt_unregister_match(&filter_vlan);
+}
+
+module_init(init);
+module_exit(fini);