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Based on 2 normalized pattern(s): 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 see http www gnu org licenses 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 [based] [from] [clk] [highbank] [c] you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 355 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
174 lines
4.8 KiB
C
174 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Description: EBTables 802.1Q match extension kernelspace module.
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* Authors: Nick Fedchik <nick@fedchik.org.ua>
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* Bart De Schuymer <bdschuym@pandora.be>
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*/
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#include <linux/if_ether.h>
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#include <linux/if_vlan.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_bridge/ebtables.h>
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#include <linux/netfilter_bridge/ebt_vlan.h>
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#define MODULE_VERS "0.6"
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MODULE_AUTHOR("Nick Fedchik <nick@fedchik.org.ua>");
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MODULE_DESCRIPTION("Ebtables: 802.1Q VLAN tag match");
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MODULE_LICENSE("GPL");
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#define GET_BITMASK(_BIT_MASK_) info->bitmask & _BIT_MASK_
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#define EXIT_ON_MISMATCH(_MATCH_,_MASK_) {if (!((info->_MATCH_ == _MATCH_)^!!(info->invflags & _MASK_))) return false; }
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static bool
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ebt_vlan_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct ebt_vlan_info *info = par->matchinfo;
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unsigned short TCI; /* Whole TCI, given from parsed frame */
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unsigned short id; /* VLAN ID, given from frame TCI */
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unsigned char prio; /* user_priority, given from frame TCI */
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/* VLAN encapsulated Type/Length field, given from orig frame */
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__be16 encap;
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if (skb_vlan_tag_present(skb)) {
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TCI = skb_vlan_tag_get(skb);
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encap = skb->protocol;
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} else {
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const struct vlan_hdr *fp;
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struct vlan_hdr _frame;
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fp = skb_header_pointer(skb, 0, sizeof(_frame), &_frame);
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if (fp == NULL)
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return false;
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TCI = ntohs(fp->h_vlan_TCI);
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encap = fp->h_vlan_encapsulated_proto;
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}
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/* Tag Control Information (TCI) consists of the following elements:
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* - User_priority. The user_priority field is three bits in length,
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* interpreted as a binary number.
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* - Canonical Format Indicator (CFI). The Canonical Format Indicator
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* (CFI) is a single bit flag value. Currently ignored.
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* - VLAN Identifier (VID). The VID is encoded as
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* an unsigned binary number.
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*/
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id = TCI & VLAN_VID_MASK;
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prio = (TCI >> 13) & 0x7;
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/* Checking VLAN Identifier (VID) */
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if (GET_BITMASK(EBT_VLAN_ID))
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EXIT_ON_MISMATCH(id, EBT_VLAN_ID);
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/* Checking user_priority */
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if (GET_BITMASK(EBT_VLAN_PRIO))
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EXIT_ON_MISMATCH(prio, EBT_VLAN_PRIO);
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/* Checking Encapsulated Proto (Length/Type) field */
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if (GET_BITMASK(EBT_VLAN_ENCAP))
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EXIT_ON_MISMATCH(encap, EBT_VLAN_ENCAP);
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return true;
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}
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static int ebt_vlan_mt_check(const struct xt_mtchk_param *par)
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{
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struct ebt_vlan_info *info = par->matchinfo;
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const struct ebt_entry *e = par->entryinfo;
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/* Is it 802.1Q frame checked? */
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if (e->ethproto != htons(ETH_P_8021Q)) {
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pr_debug("passed entry proto %2.4X is not 802.1Q (8100)\n",
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ntohs(e->ethproto));
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return -EINVAL;
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}
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/* Check for bitmask range
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* True if even one bit is out of mask
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*/
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if (info->bitmask & ~EBT_VLAN_MASK) {
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pr_debug("bitmask %2X is out of mask (%2X)\n",
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info->bitmask, EBT_VLAN_MASK);
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return -EINVAL;
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}
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/* Check for inversion flags range */
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if (info->invflags & ~EBT_VLAN_MASK) {
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pr_debug("inversion flags %2X is out of mask (%2X)\n",
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info->invflags, EBT_VLAN_MASK);
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return -EINVAL;
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}
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/* Reserved VLAN ID (VID) values
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* -----------------------------
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* 0 - The null VLAN ID.
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* 1 - The default Port VID (PVID)
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* 0x0FFF - Reserved for implementation use.
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* if_vlan.h: VLAN_N_VID 4096.
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*/
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if (GET_BITMASK(EBT_VLAN_ID)) {
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if (!!info->id) { /* if id!=0 => check vid range */
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if (info->id > VLAN_N_VID) {
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pr_debug("id %d is out of range (1-4096)\n",
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info->id);
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return -EINVAL;
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}
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/* Note: This is valid VLAN-tagged frame point.
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* Any value of user_priority are acceptable,
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* but should be ignored according to 802.1Q Std.
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* So we just drop the prio flag.
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*/
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info->bitmask &= ~EBT_VLAN_PRIO;
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}
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/* Else, id=0 (null VLAN ID) => user_priority range (any?) */
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}
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if (GET_BITMASK(EBT_VLAN_PRIO)) {
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if ((unsigned char) info->prio > 7) {
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pr_debug("prio %d is out of range (0-7)\n",
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info->prio);
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return -EINVAL;
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}
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}
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/* Check for encapsulated proto range - it is possible to be
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* any value for u_short range.
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* if_ether.h: ETH_ZLEN 60 - Min. octets in frame sans FCS
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*/
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if (GET_BITMASK(EBT_VLAN_ENCAP)) {
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if ((unsigned short) ntohs(info->encap) < ETH_ZLEN) {
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pr_debug("encap frame length %d is less than "
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"minimal\n", ntohs(info->encap));
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return -EINVAL;
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}
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}
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return 0;
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}
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static struct xt_match ebt_vlan_mt_reg __read_mostly = {
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.name = "vlan",
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.revision = 0,
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.family = NFPROTO_BRIDGE,
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.match = ebt_vlan_mt,
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.checkentry = ebt_vlan_mt_check,
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.matchsize = sizeof(struct ebt_vlan_info),
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.me = THIS_MODULE,
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};
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static int __init ebt_vlan_init(void)
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{
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pr_debug("ebtables 802.1Q extension module v" MODULE_VERS "\n");
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return xt_register_match(&ebt_vlan_mt_reg);
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}
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static void __exit ebt_vlan_fini(void)
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{
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xt_unregister_match(&ebt_vlan_mt_reg);
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}
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module_init(ebt_vlan_init);
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module_exit(ebt_vlan_fini);
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