From 9e3252b5cec76dddb9877e593c799ebe15cae0af Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Fri, 21 Sep 2018 13:10:28 -0400 Subject: Network delay simulator plugin Change-Id: I4a70c7df8f0cb368a4e1cb16f30eeef5c6058c79 Signed-off-by: Dave Barach --- src/plugins/nsim/nsim_input.c | 228 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 228 insertions(+) create mode 100644 src/plugins/nsim/nsim_input.c (limited to 'src/plugins/nsim/nsim_input.c') diff --git a/src/plugins/nsim/nsim_input.c b/src/plugins/nsim/nsim_input.c new file mode 100644 index 00000000000..50dbcb97d6b --- /dev/null +++ b/src/plugins/nsim/nsim_input.c @@ -0,0 +1,228 @@ +/* + * nsim.c - skeleton vpp engine plug-in + * + * Copyright (c) + * 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. + */ + +#include +#include +#include +#include +#include + +typedef struct +{ + f64 expired; + u32 tx_sw_if_index; +} nsim_tx_trace_t; + +#ifndef CLIB_MARCH_VARIANT +/* packet trace format function */ +static u8 * +format_nsim_tx_trace (u8 * s, va_list * args) +{ + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + nsim_tx_trace_t *t = va_arg (*args, nsim_tx_trace_t *); + + s = format (s, "NSIM: tx at %.6f sw_if_index %d", + t->expired, t->tx_sw_if_index); + return s; +} +#endif /* CLIB_MARCH_VARIANT */ + +vlib_node_registration_t nsim_node; + +#define foreach_nsim_tx_error \ +_(TX, "Packets transmitted") \ +_(DROPPED, "No buffer drops") + +typedef enum +{ +#define _(sym,str) NSIM_TX_ERROR_##sym, + foreach_nsim_tx_error +#undef _ + NSIM_N_ERROR, +} nsim_tx_error_t; + +#ifndef CLIB_MARCH_VARIANT +static char *nsim_tx_error_strings[] = { +#define _(sym,string) string, + foreach_nsim_tx_error +#undef _ +}; +#endif /* CLIB_MARCH_VARIANT */ + +typedef enum +{ + NSIM_NEXT_DROP, + NSIM_N_NEXT, +} nsim_next_t; + +always_inline uword +nsim_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node, + vlib_frame_t * f, int is_trace) +{ + nsim_main_t *nsm = &nsim_main; + u32 my_thread_index = vm->thread_index; + u32 *my_buffer_cache = nsm->buffer_indices_by_thread[my_thread_index]; + nsim_wheel_t *wp = nsm->wheel_by_thread[my_thread_index]; + f64 now = vlib_time_now (vm); + uword n_rx_packets = 0; + vlib_buffer_t *b0; + u32 bi0, next0; + vlib_buffer_free_list_t *fl; + u32 *to_next; + u32 next_index; + u32 n_left_to_next; + nsim_wheel_entry_t *ep; + + /* Nothing on the scheduler wheel? */ + if (wp->cursize == 0) + return 0; + + /* First entry on the wheel isn't expired? */ + ep = wp->entries + wp->head; + if (ep->tx_time > now) + return n_rx_packets; + + /* + * We use per-thread buffer caches, so we need the freelist to + * initialize them... + */ + fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX); + next_index = node->cached_next_index; + + while (wp->cursize) + { + /* Be aware: this is not the usual coding pattern */ + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + + while (n_left_to_next > 0 && ep->tx_time <= now) + { + /* Out of local buffer cache? */ + if (PREDICT_FALSE (_vec_len (my_buffer_cache) == 0)) + { + u32 n = + vlib_buffer_alloc (vm, my_buffer_cache, VLIB_FRAME_SIZE); + _vec_len (my_buffer_cache) = n; + + /* Ugh, drop the rest of the expired entries */ + if (n == 0) + { + u32 drops = 0; + while (ep->tx_time <= now && wp->cursize) + { + wp->head++; + if (wp->head == wp->wheel_size) + wp->head = 0; + ep = wp->entries + wp->head; + wp->cursize--; + drops++; + } + /* Count the drops */ + vlib_node_increment_counter (vm, node->node_index, + NSIM_TX_ERROR_DROPPED, drops); + /* Ship any pkts we already processed */ + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + return n_rx_packets + drops; + } + } + + /* Allocate a buffer */ + bi0 = my_buffer_cache[_vec_len (my_buffer_cache) - 1]; + _vec_len (my_buffer_cache) -= 1; + + to_next[0] = bi0; + to_next += 1; + n_left_to_next -= 1; + + b0 = vlib_get_buffer (vm, bi0); + /* Initialize the buffer */ + vlib_buffer_init_for_free_list (b0, fl); + + b0->current_data = 0; + b0->current_length = ep->current_length; + + /* Copy data from the ring */ + clib_memcpy (b0->data, ep->data, ep->current_length); + b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID; + vnet_buffer (b0)->sw_if_index[VLIB_TX] = ep->tx_sw_if_index; + vnet_buffer (b0)->sw_if_index[VLIB_RX] = + (ep->tx_sw_if_index == nsm->sw_if_index0) ? nsm->sw_if_index1 : + nsm->sw_if_index0; + next0 = (ep->tx_sw_if_index == nsm->sw_if_index0) ? + nsm->output_next_index0 : nsm->output_next_index1; + + /* verify speculative enqueue, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, + to_next, n_left_to_next, + bi0, next0); + /* Advance to the next ring entry */ + wp->head++; + if (wp->head == wp->wheel_size) + wp->head = 0; + wp->cursize--; + ep = wp->entries + wp->head; + n_rx_packets++; + + /* Out of ring entries? */ + if (PREDICT_FALSE (wp->cursize == 0)) + break; + } + + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + + /* If the current entry hasn't expired, we're done */ + if (ep->tx_time > now) + break; + } + return n_rx_packets; +} + +VLIB_NODE_FN (nsim_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node, + vlib_frame_t * frame) +{ + if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE)) + return nsim_input_inline (vm, node, frame, 1 /* is_trace */ ); + else + return nsim_input_inline (vm, node, frame, 0 /* is_trace */ ); + +} + +/* *INDENT-OFF* */ +#ifndef CLIB_MARCH_VARIANT +VLIB_REGISTER_NODE (nsim_input_node) = +{ + .type = VLIB_NODE_TYPE_INPUT, + .name = "nsim-wheel", + + /* Will be enabled if/when the feature is configured */ + .state = VLIB_NODE_STATE_DISABLED, + + .format_trace = format_nsim_tx_trace, + + .n_errors = NSIM_N_ERROR, + .error_strings = nsim_tx_error_strings, +}; +#endif /* CLIB_MARCH_VARIANT */ +/* *INDENT-ON* */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ -- cgit 1.2.3-korg