2 * l2_vtr.h : layer 2 vlan tag rewrite processing
4 * Copyright (c) 2013 Cisco and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #ifndef included_vnet_l2_vtr_h
19 #define included_vnet_l2_vtr_h
21 #include <vlib/vlib.h>
22 #include <vnet/vnet.h>
23 #include <vnet/ethernet/packet.h>
24 #include <vnet/l2/l2_vtr.h>
26 // VTR config options for API and CLI support
39 // Per-interface vlan tag rewrite configuration
40 // There will be one instance of this struct for each sw_if_index
41 // for both input vtr and output vtr
44 // Up to two vlan tags to push.
45 // if there is only one vlan tag to push, it is in tags[1].
46 ethernet_vlan_header_tv_t tags[2];
52 u8 push_bytes; // number of bytes to push for up to 2 vlans (0,4,8)
53 u8 pop_bytes; // number of bytes to pop for up to 2 vlans (0,4,8)
55 u16 push_and_pop_bytes; // if 0 then the feature is disabled
60 // Perform the configured tag rewrite on the packet.
61 // Return 0 if ok, 1 if packet should be dropped (e.g. tried to pop too many tags)
63 l2_vtr_process (vlib_buffer_t * b0,
64 vtr_config_t * config)
70 eth = vlib_buffer_get_current (b0);
72 // copy the 12B dmac and smac to a temporary location
73 temp_8 = *((u64 *)eth);
74 temp_4 = *((u32 *)(eth+8));
76 // adjust for popped tags
77 eth += config->pop_bytes;
79 // if not enough tags to pop then drop packet
80 if (PREDICT_FALSE ((vnet_buffer(b0)->l2.l2_len - 12) < config->pop_bytes)) {
84 // copy the 2 new tags to the start of the packet
85 *((u64 *)(eth + 12 - 8)) = config->raw_tags;
89 // adjust for pushed tags:
90 eth -= config->push_bytes;
92 // copy the 12 dmac and smac back to the packet
93 *((u64 *)eth) = temp_8;
94 *((u32 *)(eth+8)) = temp_4;
97 vnet_buffer(b0)->l2.l2_len += (word)config->push_bytes - (word)config->pop_bytes;
100 vlib_buffer_advance(b0, (word)config->pop_bytes - (word)config->push_bytes);
106 // Perform the egress pre-vlan tag rewrite EFP Filter check. The post-vlan tag rewrite
107 // check is a separate graph node.
109 // This check insures that a packet being output to an interface (before output vtr
110 // is performed) has vlan tags that match those on a packet received from that
111 // interface (after vtr has been performed).
112 // This means verifying that any tags pushed by input vtr are present on the packet.
114 // Return 0 if ok, 1 if packet should be dropped.
115 // This function should be passed the input vtr config for the interface.
117 l2_efp_filter_process (vlib_buffer_t * b0,
118 vtr_config_t * in_config)
124 eth = vlib_buffer_get_current (b0);
126 // If there are 2 tags pushed, they must match config->tags[0] and config->tags[1].
127 // If there is one tag pushed, it must match config->tag[1].
128 // If there are 0 tags pushed, the check passes.
130 // mask for two vlan id and ethertypes, no cos bits
131 tag_mask = clib_net_to_host_u64(0xFFFF0FFFFFFF0FFF);
132 // mask for one vlan id and ethertype, no cos bits
133 tag_mask = (in_config->push_bytes == 4) ? clib_net_to_host_u64(0xFFFF0FFF) : tag_mask;
134 // mask for always match
135 tag_mask = (in_config->push_bytes == 0) ? 0 : tag_mask;
137 // Read 8B from the packet, getting the proper set of vlan tags
138 // For 0 push bytes, the address doesn't matter since the mask clears the data to 0.
139 packet_tags = *((u64 *)(eth + 4 + in_config->push_bytes));
141 // Check if the packet tags match the configured tags
142 return (packet_tags & tag_mask) != in_config->raw_tags;
146 // Configure vtag tag rewrite on the given interface.
147 // Return 1 if there is an error, 0 if ok
148 u32 l2vtr_configure(vlib_main_t * vlib_main,
149 vnet_main_t * vnet_main,
156 // Get vtag tag rewrite on the given interface.
157 // Return 1 if there is an error, 0 if ok
158 u32 l2vtr_get (vlib_main_t * vlib_main,
159 vnet_main_t * vnet_main,
166 #endif // included_vnet_l2_vtr_h