diff options
Diffstat (limited to 'vnet/vnet/l2/l2_vtr.h')
| -rw-r--r-- | vnet/vnet/l2/l2_vtr.h | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/vnet/vnet/l2/l2_vtr.h b/vnet/vnet/l2/l2_vtr.h new file mode 100644 index 00000000000..aef6c6d255e --- /dev/null +++ b/vnet/vnet/l2/l2_vtr.h @@ -0,0 +1,167 @@ +/* + * 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 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 + |