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/*
* l2_vtr.h : layer 2 vlan tag rewrite processing
*
* Copyright (c) 2013 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef included_vnet_l2_vtr_h
#define included_vnet_l2_vtr_h
#include <vlib/vlib.h>
#include <vnet/vnet.h>
#include <vnet/ethernet/packet.h>
#include <vnet/l2/l2_vtr.h>
// VTR config options for API and CLI support
typedef enum {
L2_VTR_DISABLED,
L2_VTR_PUSH_1,
L2_VTR_PUSH_2,
L2_VTR_POP_1,
L2_VTR_POP_2,
L2_VTR_TRANSLATE_1_1,
L2_VTR_TRANSLATE_1_2,
L2_VTR_TRANSLATE_2_1,
L2_VTR_TRANSLATE_2_2
} l2_vtr_op_t;
// Per-interface vlan tag rewrite configuration
// There will be one instance of this struct for each sw_if_index
// for both input vtr and output vtr
typedef struct {
union {
// Up to two vlan tags to push.
// if there is only one vlan tag to push, it is in tags[1].
ethernet_vlan_header_tv_t tags[2];
u64 raw_tags;
};
union {
struct {
u8 push_bytes; // number of bytes to push for up to 2 vlans (0,4,8)
u8 pop_bytes; // number of bytes to pop for up to 2 vlans (0,4,8)
};
u16 push_and_pop_bytes; // if 0 then the feature is disabled
};
} vtr_config_t;
// Perform the configured tag rewrite on the packet.
// Return 0 if ok, 1 if packet should be dropped (e.g. tried to pop too many tags)
always_inline u32
l2_vtr_process (vlib_buffer_t * b0,
vtr_config_t * config)
{
u64 temp_8;
u32 temp_4;
u8 * eth;
eth = vlib_buffer_get_current (b0);
// copy the 12B dmac and smac to a temporary location
temp_8 = *((u64 *)eth);
temp_4 = *((u32 *)(eth+8));
// adjust for popped tags
eth += config->pop_bytes;
// if not enough tags to pop then drop packet
if (PREDICT_FALSE ((vnet_buffer(b0)->l2.l2_len - 12) < config->pop_bytes)) {
return 1;
}
// copy the 2 new tags to the start of the packet
*((u64 *)(eth + 12 - 8)) = config->raw_tags;
// TODO: set cos bits
// adjust for pushed tags:
eth -= config->push_bytes;
// copy the 12 dmac and smac back to the packet
*((u64 *)eth) = temp_8;
*((u32 *)(eth+8)) = temp_4;
// Update l2_len
vnet_buffer(b0)->l2.l2_len += (word)config->push_bytes - (word)config->pop_bytes;
// Update vlan tag count
ethernet_buffer_adjust_vlan_count_by_bytes(b0,
(word)config->push_bytes - (word)config->pop_bytes);
// Update packet len
vlib_buffer_advance(b0, (word)config->pop_bytes - (word)config->push_bytes);
return 0;
}
// Perform the egress pre-vlan tag rewrite EFP Filter check. The post-vlan tag rewrite
// check is a separate graph node.
//
// This check insures that a packet being output to an interface (before output vtr
// is performed) has vlan tags that match those on a packet received from that
// interface (after vtr has been performed).
// This means verifying that any tags pushed by input vtr are present on the packet.
//
// Return 0 if ok, 1 if packet should be dropped.
// This function should be passed the input vtr config for the interface.
always_inline u8
l2_efp_filter_process (vlib_buffer_t * b0,
vtr_config_t * in_config)
{
u8 * eth;
u64 packet_tags;
u64 tag_mask;
eth = vlib_buffer_get_current (b0);
// If there are 2 tags pushed, they must match config->tags[0] and config->tags[1].
// If there is one tag pushed, it must match config->tag[1].
// If there are 0 tags pushed, the check passes.
// mask for two vlan id and ethertypes, no cos bits
tag_mask = clib_net_to_host_u64(0xFFFF0FFFFFFF0FFF);
// mask for one vlan id and ethertype, no cos bits
tag_mask = (in_config->push_bytes == 4) ? clib_net_to_host_u64(0xFFFF0FFF) : tag_mask;
// mask for always match
tag_mask = (in_config->push_bytes == 0) ? 0 : tag_mask;
// Read 8B from the packet, getting the proper set of vlan tags
// For 0 push bytes, the address doesn't matter since the mask clears the data to 0.
packet_tags = *((u64 *)(eth + 4 + in_config->push_bytes));
// Check if the packet tags match the configured tags
return (packet_tags & tag_mask) != in_config->raw_tags;
}
// Configure vtag tag rewrite on the given interface.
// Return 1 if there is an error, 0 if ok
u32 l2vtr_configure(vlib_main_t * vlib_main,
vnet_main_t * vnet_main,
u32 sw_if_index,
u32 vtr_op,
u32 push_dot1q,
u32 vtr_tag1,
u32 vtr_tag2);
// Get vtag tag rewrite on the given interface.
// Return 1 if there is an error, 0 if ok
u32 l2vtr_get (vlib_main_t * vlib_main,
vnet_main_t * vnet_main,
u32 sw_if_index,
u32 *vtr_op,
u32 *push_dot1q,
u32 *vtr_tag1,
u32 *vtr_tag2);
#endif // included_vnet_l2_vtr_h
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