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/*
* Copyright (c) 2017-2020 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 __HICN_DATA_FWD_H__
#define __HICN_DATA_FWD_H__
#include <vlib/buffer.h>
#include "pcs.h"
/**
* @file data_fwd.h
*
* This is the node encoutered by data packets after the hicn-data-pcslookup.
* This node has two goals: 1) clone/copy the vlib buffer as many time as the number
* of faces stored in the pit entry, 2) store a clone/copy of the vlib buffer in the CS.
* Unless there are memory issue (no more vlib buffer available to perform cloning/copy),
* a single vlib buffer received might results in several vlib buffer sent to the next
* vlib node (hicn4-iface-output or hicn6-iface-output).
*
* It must be noted that cloning is possible only if the lentgh of the data pointed by
* the vlib buffer is at least 256 bytes. This is due to an imposition in the vpp source
* code. In all the other cases the vlib buffer is copied. Cloning is performed by advancing
* the vlib buffer of 256 bytes and a new vlib buffer is created and chained in from of the received
* buffer. Additionally, the 256 bytes removed (advanced) from the received vlib buffer are
* copied in the head vlib buffer. In case of multiple cloning for the same vlib buffer, this
* mechanism allows us to have a different hICN header for each clone (+ the same additional bytes
* due to the vpp restriction on cloning).
*/
/* Trace context struct */
typedef struct
{
u32 next_index;
u32 sw_if_index;
u8 pkt_type;
u8 packet_data[64];
} hicn_data_fwd_trace_t;
typedef enum
{
HICN_DATA_FWD_NEXT_V4_LOOKUP,
HICN_DATA_FWD_NEXT_V6_LOOKUP,
HICN_DATA_FWD_NEXT_IFACE4_OUT,
HICN_DATA_FWD_NEXT_IFACE6_OUT,
HICN_DATA_FWD_NEXT_ERROR_DROP,
HICN_DATA_FWD_N_NEXT,
} hicn_data_fwd_next_t;
/**
* @brief Create a maximum of 256 clones of buffer and store them
* in the supplied array. Unlike the original function in the vlib
* library, we don't prevent cloning if n_buffer==1 and if
* s->current_length <= head_end_offset + CLIB_CACHE_LINE_BYTES * 2.
*
* @param vm - (vlib_main_t *) vlib main data structure pointer
* @param src_buffer - (u32) source buffer index
* @param buffers - (u32 * ) buffer index array
* @param n_buffers - (u16) number of buffer clones requested (<=256)
* @param head_end_offset - (u16) offset relative to current position
* where packet head ends
* @return - (u16) number of buffers actually cloned, may be
* less than the number requested or zero
*/
always_inline u16
vlib_buffer_clone_256_2 (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
u16 n_buffers, u16 head_end_offset)
{
u16 i;
vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer);
ASSERT (n_buffers);
ASSERT (n_buffers <= 256);
if (s->current_length <= head_end_offset + CLIB_CACHE_LINE_BYTES * 2)
{
for (i = 0; i < n_buffers; i++)
{
vlib_buffer_t *d;
d = vlib_buffer_copy (vm, s);
if (d == 0)
return i;
buffers[i] = vlib_get_buffer_index (vm, d);
}
return n_buffers;
}
n_buffers = vlib_buffer_alloc_from_pool (vm, buffers, n_buffers,
s->buffer_pool_index);
for (i = 0; i < n_buffers; i++)
{
vlib_buffer_t *d = vlib_get_buffer (vm, buffers[i]);
d->current_data = s->current_data;
d->current_length = head_end_offset;
d->trace_handle = s->trace_handle;
d->total_length_not_including_first_buffer = s->current_length -
head_end_offset;
if (PREDICT_FALSE (s->flags & VLIB_BUFFER_NEXT_PRESENT))
{
d->total_length_not_including_first_buffer +=
s->total_length_not_including_first_buffer;
}
d->flags = s->flags | VLIB_BUFFER_NEXT_PRESENT;
d->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
d->trace_handle = s->trace_handle;
clib_memcpy_fast (d->opaque, s->opaque, sizeof (s->opaque));
clib_memcpy_fast (d->opaque2, s->opaque2, sizeof (s->opaque2));
clib_memcpy_fast (vlib_buffer_get_current (d),
vlib_buffer_get_current (s), head_end_offset);
d->next_buffer = src_buffer;
}
vlib_buffer_advance (s, head_end_offset);
s->ref_count = n_buffers;
while (s->flags & VLIB_BUFFER_NEXT_PRESENT)
{
s = vlib_get_buffer (vm, s->next_buffer);
s->ref_count = n_buffers;
}
return n_buffers;
}
/**
* @brief Create multiple clones of buffer and store them
* in the supplied array. Unlike the function in the vlib library,
* we allow src_buffer to have ref_count != 0.
*
* @param vm - (vlib_main_t *) vlib main data structure pointer
* @param src_buffer - (u32) source buffer index
* @param buffers - (u32 * ) buffer index array
* @param n_buffers - (u16) number of buffer clones requested (<=256)
* @param head_end_offset - (u16) offset relative to current position
* where packet head ends
* @return - (u16) number of buffers actually cloned, may be
* less than the number requested or zero
*/
always_inline u16
vlib_buffer_clone2 (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
u16 n_buffers, u16 head_end_offset)
{
vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer);
/*
* total_length_not_including_first_buffer is not initialized to 0
* when a buffer is used.
*/
if (PREDICT_TRUE (s->next_buffer == 0))
s->total_length_not_including_first_buffer = 0;
u16 n_cloned = 0;
u8 n_clone_src = 255 - s->ref_count;
/*
* We need to copy src for all the clones that cannot be chained in
* the src_buffer
*/
/* MAX(ref_count) = 256 */
if (n_buffers > n_clone_src)
{
vlib_buffer_t *copy;
/* Ok to call the original vlib_buffer_copy. */
copy = vlib_buffer_copy (vm, s);
n_cloned += vlib_buffer_clone (vm,
vlib_get_buffer_index (vm, copy),
buffers,
n_buffers - n_clone_src,
head_end_offset);
n_buffers -= n_cloned;
}
/*
* vlib_buffer_clone_256 check if ref_count is 0. We force it to be
* 0 before calling the function and we retore it to the right value
* after the function has been called
*/
u8 tmp_ref_count = s->ref_count;
s->ref_count = 1;
/*
* The regular vlib_buffer_clone_256 does copy if we need to clone
* only one packet. While this is not a problem per se, it adds
* complexity to the code, especially because we need to add 1 to
* ref_count when the packet is cloned.
*/
n_cloned += vlib_buffer_clone_256_2 (vm,
src_buffer,
(buffers + n_cloned),
n_buffers, head_end_offset);
s->ref_count += (tmp_ref_count - 1);
return n_cloned;
}
#endif /* //__HICN_DATA_FWD_H__ */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables: eval: (c-set-style "gnu") End:
*/
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