/* * Copyright (c) 2016 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. */ #include <vnet/buffer.h> #include <vnet/vnet.h> #include <vnet/bier/bier_fmask.h> #include <vnet/bier/bier_hdr_inlines.h> #include <vnet/bier/bier_table.h> #include <vnet/bier/bier_fmask.h> /** * Struct maintaining the per-worker thread data for BIER lookups */ typedef struct bier_lookup_main_t_ { /* per-cpu vector of cloned packets */ u32 **blm_clones; /* per-cpu vector of BIER fmasks */ u32 **blm_fmasks; } bier_lookup_main_t; /** * Single instance of the lookup main */ static bier_lookup_main_t bier_lookup_main; static char * bier_lookup_error_strings[] = { #define bier_error(n,s) s, #include <vnet/bier/bier_lookup_error.def> #undef bier_error }; /* * Keep these values semantically the same as BIER lookup */ #define foreach_bier_lookup_next \ _(DROP, "bier-drop") \ _(OUTPUT, "bier-output") typedef enum { #define _(s,n) BIER_LOOKUP_NEXT_##s, foreach_bier_lookup_next #undef _ BIER_LOOKUP_N_NEXT, } bier_lookup_next_t; typedef enum { #define bier_error(n,s) BIER_LOOKUP_ERROR_##n, #include <vnet/bier/bier_lookup_error.def> #undef bier_error BIER_LOOKUP_N_ERROR, } bier_lookup_error_t; vlib_node_registration_t bier_lookup_node; /** * @brief Packet trace record for a BIER lookup */ typedef struct bier_lookup_trace_t_ { u32 next_index; index_t bt_index; index_t bfm_index; } bier_lookup_trace_t; static uword bier_lookup (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { u32 n_left_from, next_index, * from, * to_next; bier_lookup_main_t *blm = &bier_lookup_main; u32 thread_index = vlib_get_thread_index(); bier_bit_mask_bucket_t buckets_copy[BIER_HDR_BUCKETS_4096]; from = vlib_frame_vector_args (from_frame); n_left_from = from_frame->n_vectors; next_index = BIER_LOOKUP_NEXT_DROP; while (n_left_from > 0) { u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { u32 next0, bi0, n_bytes, bti0, bfmi0; const bier_fmask_t *bfm0; const bier_table_t *bt0; u16 index, num_buckets; const bier_hdr_t *bh0; bier_bit_string_t bbs; vlib_buffer_t *b0; bier_bp_t fbs; int bucket; bi0 = from[0]; from += 1; n_left_from -= 1; b0 = vlib_get_buffer (vm, bi0); bh0 = vlib_buffer_get_current (b0); bti0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX]; /* * default to drop so that if no bits are matched then * that is where we go - DROP. */ next0 = BIER_LOOKUP_NEXT_DROP; /* * At the imposition or input node, * we stored the BIER Table index in the TX adjacency */ bt0 = bier_table_get(vnet_buffer(b0)->ip.adj_index[VLIB_TX]); /* * we should only forward via one for the ECMP tables */ ASSERT(!bier_table_is_main(bt0)); /* * number of integer sized buckets */ n_bytes = bier_hdr_len_id_to_num_buckets(bt0->bt_id.bti_hdr_len); vnet_buffer(b0)->mpls.bier.n_bytes = n_bytes; vnet_buffer(b0)->sw_if_index[VLIB_TX] = ~0; num_buckets = n_bytes / sizeof(int); bier_bit_string_init(&bbs, bt0->bt_id.bti_hdr_len, buckets_copy); memcpy(bbs.bbs_buckets, bh0->bh_bit_string, bbs.bbs_len); /* * reset the fmask storage vector */ vec_reset_length (blm->blm_fmasks[thread_index]); /* * Loop through the buckets in the header */ for (index = 0; index < num_buckets; index++) { /* * loop through each bit in the bucket */ bucket = ((int*)bbs.bbs_buckets)[index]; while (bucket) { fbs = bier_find_first_bit_string_set(bucket); fbs += (((num_buckets - 1) - index) * BIER_BIT_MASK_BITS_PER_INT); bfmi0 = bier_table_fwd_lookup(bt0, fbs); /* * whatever happens, the bit we just looked for * MUST be cleared from the packet * otherwise we could be in this loop a while ... */ bier_bit_string_clear_bit(&bbs, fbs); if (PREDICT_TRUE(INDEX_INVALID != bfmi0)) { bfm0 = bier_fmask_get(bfmi0); /* * use the bit-string on the fmask to reset * the bits in the header we are walking */ bier_bit_string_clear_string( &bfm0->bfm_bits.bfmb_input_reset_string, &bbs); bucket = ((int*)bbs.bbs_buckets)[index]; /* * the fmask is resolved so replicate a * packet its way */ next0 = BIER_LOOKUP_NEXT_OUTPUT; vec_add1 (blm->blm_fmasks[thread_index], bfmi0); } else { /* * go to the next bit-position set */ vlib_node_increment_counter( vm, node->node_index, BIER_LOOKUP_ERROR_FMASK_UNRES, 1); bucket = ((int*)bbs.bbs_buckets)[index]; continue; } } } /* * Full mask now processed. * Create the number of clones we need based on the number * of fmasks we are sending to. */ u16 num_cloned, clone; u32 n_clones; n_clones = vec_len(blm->blm_fmasks[thread_index]); if (PREDICT_TRUE(0 != n_clones)) { vec_set_len(blm->blm_clones[thread_index], n_clones); num_cloned = vlib_buffer_clone(vm, bi0, blm->blm_clones[thread_index], n_clones, VLIB_BUFFER_CLONE_HEAD_SIZE); if (num_cloned != n_clones) { vec_set_len(blm->blm_clones[thread_index], num_cloned); vlib_node_increment_counter (vm, node->node_index, BIER_LOOKUP_ERROR_BUFFER_ALLOCATION_FAILURE, 1); } for (clone = 0; clone < num_cloned; clone++) { vlib_buffer_t *c0; u32 ci0; ci0 = blm->blm_clones[thread_index][clone]; c0 = vlib_get_buffer(vm, ci0); vnet_buffer(c0)->ip.adj_index[VLIB_TX] = blm->blm_fmasks[thread_index][clone]; to_next[0] = ci0; to_next += 1; n_left_to_next -= 1; if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) { bier_lookup_trace_t *tr; tr = vlib_add_trace (vm, node, c0, sizeof (*tr)); tr->bt_index = bti0; tr->bfm_index = blm->blm_fmasks[thread_index][clone]; } vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, ci0, next0); /* * After the enqueue it is possible that we over-flow the * frame of the to-next node. When this happens we need to * 'put' that full frame to the node and get a fresh empty * one. Note that these are macros with side effects that * change to_next & n_left_to_next */ if (PREDICT_FALSE(0 == n_left_to_next)) { vlib_put_next_frame (vm, node, next_index, n_left_to_next); vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); } } } else { /* * no clones/replications required. drop this packet */ next0 = BIER_LOOKUP_NEXT_DROP; to_next[0] = bi0; to_next += 1; n_left_to_next -= 1; if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) { bier_lookup_trace_t *tr; tr = vlib_add_trace (vm, node, b0, sizeof (*tr)); tr->bt_index = bti0; tr->bfm_index = ~0; } vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next0); } } vlib_put_next_frame(vm, node, next_index, n_left_to_next); } vlib_node_increment_counter(vm, bier_lookup_node.index, BIER_LOOKUP_ERROR_NONE, from_frame->n_vectors); return (from_frame->n_vectors); } static u8 * format_bier_lookup_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 *); bier_lookup_trace_t * t = va_arg (*args, bier_lookup_trace_t *); s = format (s, "BIER: next [%d], tbl:%d BFM:%d", t->next_index, t->bt_index, t->bfm_index); return s; } VLIB_REGISTER_NODE (bier_lookup_node) = { .function = bier_lookup, .name = "bier-lookup", /* Takes a vector of packets. */ .vector_size = sizeof (u32), .n_errors = BIER_LOOKUP_N_ERROR, .error_strings = bier_lookup_error_strings, .format_trace = format_bier_lookup_trace, .n_next_nodes = BIER_LOOKUP_N_NEXT, .next_nodes = { [BIER_LOOKUP_NEXT_DROP] = "bier-drop", [BIER_LOOKUP_NEXT_OUTPUT] = "bier-output", }, }; clib_error_t * bier_lookup_module_init (vlib_main_t * vm) { bier_lookup_main_t *blm = &bier_lookup_main; u32 thread_index; vec_validate (blm->blm_clones, vlib_num_workers()); vec_validate (blm->blm_fmasks, vlib_num_workers()); for (thread_index = 0; thread_index <= vlib_num_workers(); thread_index++) { /* * 1024 is the most we will ever need to support * a Bit-Mask length of 1024 */ vec_validate(blm->blm_fmasks[thread_index], 1023); vec_validate(blm->blm_clones[thread_index], 1023); } return 0; } VLIB_INIT_FUNCTION (bier_lookup_module_init);