/* *------------------------------------------------------------------ * ip_path_mtu.c * * Copyright (c) 2020 Graphiant. * 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/ip/ip_path_mtu.h> #include <vnet/ip/ip_frag.h> typedef enum { IP_PMTU_DROP, IP_PMTU_N_NEXT, } ip_pmtu_next_t; typedef struct ip_pmtu_trace_t_ { u16 pmtu; u16 packet_size; } ip_pmtu_trace_t; static u8 * format_ip_pmtu_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 *); ip_pmtu_trace_t *t = va_arg (*args, ip_pmtu_trace_t *); s = format (s, "path mtu:%d packet size:%d", t->pmtu, t->packet_size); return s; } static inline uword ip_pmtu_dpo_inline (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame, ip_address_family_t af) { u32 n_left_from, *from, next_index, *to_next, n_left_to_next; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; next_index = node->cached_next_index; u32 *buffer = 0; while (n_left_from > 0) { vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { const ip_pmtu_dpo_t *ipm0; u32 pi0, *frag_from, frag_left; vlib_buffer_t *p0; ip_frag_error_t error0; u16 next0; /* * Note: The packet is not enqueued now. It is instead put * in a vector where other fragments will be put as well. */ pi0 = from[0]; from += 1; n_left_from -= 1; p0 = vlib_get_buffer (vm, pi0); ipm0 = ip_pmtu_dpo_get (vnet_buffer (p0)->ip.adj_index[VLIB_TX]); vnet_buffer (p0)->ip.adj_index[VLIB_TX] = ipm0->ipm_dpo.dpoi_index; next0 = ipm0->ipm_dpo.dpoi_next_node; if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED)) { ip_pmtu_trace_t *t; t = vlib_add_trace (vm, node, p0, sizeof (*t)); t->pmtu = ipm0->ipm_pmtu; t->packet_size = vlib_buffer_length_in_chain (vm, p0); } if (AF_IP6 == af) error0 = ip6_frag_do_fragment (vm, pi0, ipm0->ipm_pmtu, 0, &buffer); else error0 = ip4_frag_do_fragment (vm, pi0, ipm0->ipm_pmtu, 0, &buffer); if (AF_IP4 == af && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET) { icmp4_error_set_vnet_buffer ( p0, ICMP4_destination_unreachable, ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set, ipm0->ipm_pmtu); next0 = IP_FRAG_NEXT_ICMP_ERROR; } else { next0 = (error0 == IP_FRAG_ERROR_NONE ? next0 : IP_FRAG_NEXT_DROP); } if (error0 == IP_FRAG_ERROR_NONE) { /* Free original buffer chain */ vlib_buffer_free_one (vm, pi0); /* Free original packet */ } else { vlib_error_count (vm, node->node_index, error0, 1); vec_add1 (buffer, pi0); /* Get rid of the original buffer */ } /* Send fragments that were added in the frame */ frag_from = buffer; frag_left = vec_len (buffer); while (frag_left > 0) { while (frag_left > 0 && n_left_to_next > 0) { u32 i; i = to_next[0] = frag_from[0]; frag_from += 1; frag_left -= 1; to_next += 1; n_left_to_next -= 1; vlib_get_buffer (vm, i)->error = node->errors[error0]; vlib_validate_buffer_enqueue_x1 ( vm, node, next_index, to_next, n_left_to_next, i, next0); } 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); } vec_reset_length (buffer); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } vec_free (buffer); return frame->n_vectors; } // clang-format off VLIB_NODE_FN (ip4_ip_pmtu_dpo_node) (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame) { return (ip_pmtu_dpo_inline (vm, node, from_frame, 0)); } VLIB_NODE_FN (ip6_ip_pmtu_dpo_node) (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame) { return (ip_pmtu_dpo_inline (vm, node, from_frame, 1)); } VLIB_REGISTER_NODE (ip4_ip_pmtu_dpo_node) = { .name = "ip4-pmtu-dpo", .vector_size = sizeof (u32), .format_trace = format_ip_pmtu_trace, .n_errors = IP_FRAG_N_ERROR, .error_strings = ip4_frag_error_strings, .n_next_nodes = IP_PMTU_N_NEXT, .next_nodes = { [IP_PMTU_DROP] = "ip4-drop", } }; VLIB_REGISTER_NODE (ip6_ip_pmtu_dpo_node) = { .name = "ip6-pmtu-dpo", .vector_size = sizeof (u32), .format_trace = format_ip_pmtu_trace, .n_errors = IP_FRAG_N_ERROR, .error_strings = ip4_frag_error_strings, .n_next_nodes = IP_PMTU_N_NEXT, .next_nodes = { [IP_PMTU_DROP] = "ip6-drop", } }; // clang-format on /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */