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Diffstat (limited to 'hicn-plugin/src/data_fwd.h')
| -rw-r--r-- | hicn-plugin/src/data_fwd.h | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/hicn-plugin/src/data_fwd.h b/hicn-plugin/src/data_fwd.h new file mode 100644 index 000000000..d95f564c3 --- /dev/null +++ b/hicn-plugin/src/data_fwd.h @@ -0,0 +1,214 @@ +/* + * 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: + */ |