/* * DHCP feature; applied as an input feature to select DHCP packets * * Copyright (c) 2013 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 <dhcp/client.h> #include <vnet/udp/udp_local.h> #define foreach_dhcp_client_detect \ _(EXTRACT, "Extract") typedef enum { #define _(sym,str) DHCP_CLIENT_DETECT_ERROR_##sym, foreach_dhcp_client_detect #undef _ DHCP_CLIENT_DETECT_N_ERROR, } dhcp_client_detect_error_t; static char *dhcp_client_detect_error_strings[] = { #define _(sym,string) string, foreach_dhcp_client_detect #undef _ }; typedef enum { #define _(sym,str) DHCP_CLIENT_DETECT_NEXT_##sym, foreach_dhcp_client_detect #undef _ DHCP_CLIENT_DETECT_N_NEXT, } dhcp_client_detect_next_t; /** * per-packet trace data */ typedef struct dhcp_client_detect_trace_t_ { /* per-pkt trace data */ u8 extracted; } dhcp_client_detect_trace_t; VLIB_NODE_FN (dhcp_client_detect_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { dhcp_client_detect_next_t next_index; u16 dhcp_client_port_network_order; u32 n_left_from, *from, *to_next; u32 extractions; dhcp_client_port_network_order = clib_net_to_host_u16 (UDP_DST_PORT_dhcp_to_client); next_index = 0; extractions = 0; n_left_from = frame->n_vectors; from = vlib_frame_vector_args (frame); while (n_left_from > 0) { u32 n_left_to_next; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); /* * This loop is optimised not so we can really quickly process DHCp * offers... but so we can quickly sift them out when the interface * is also receiving 'normal' packets */ while (n_left_from >= 8 && n_left_to_next >= 4) { udp_header_t *udp0, *udp1, *udp2, *udp3; ip4_header_t *ip0, *ip1, *ip2, *ip3; vlib_buffer_t *b0, *b1, *b2, *b3; u32 next0, next1, next2, next3; u32 bi0, bi1, bi2, bi3; next0 = next1 = next2 = next3 = ~0; bi0 = to_next[0] = from[0]; bi1 = to_next[1] = from[1]; bi2 = to_next[2] = from[2]; bi3 = to_next[3] = from[3]; /* Prefetch next iteration. */ { vlib_buffer_t *p2, *p3, *p4, *p5; p2 = vlib_get_buffer (vm, from[2]); p3 = vlib_get_buffer (vm, from[3]); p4 = vlib_get_buffer (vm, from[4]); p5 = vlib_get_buffer (vm, from[5]); vlib_prefetch_buffer_header (p2, STORE); vlib_prefetch_buffer_header (p3, STORE); vlib_prefetch_buffer_header (p4, STORE); vlib_prefetch_buffer_header (p5, STORE); CLIB_PREFETCH (p2->data, sizeof (ip0[0]) + sizeof (udp0[0]), STORE); CLIB_PREFETCH (p3->data, sizeof (ip0[0]) + sizeof (udp0[0]), STORE); CLIB_PREFETCH (p4->data, sizeof (ip0[0]) + sizeof (udp0[0]), STORE); CLIB_PREFETCH (p5->data, sizeof (ip0[0]) + sizeof (udp0[0]), STORE); } from += 4; to_next += 4; n_left_from -= 4; n_left_to_next -= 4; b0 = vlib_get_buffer (vm, bi0); b1 = vlib_get_buffer (vm, bi1); b2 = vlib_get_buffer (vm, bi2); b3 = vlib_get_buffer (vm, bi3); ip0 = vlib_buffer_get_current (b0); ip1 = vlib_buffer_get_current (b1); ip2 = vlib_buffer_get_current (b2); ip3 = vlib_buffer_get_current (b2); vnet_feature_next (&next0, b0); vnet_feature_next (&next1, b1); vnet_feature_next (&next2, b2); vnet_feature_next (&next3, b3); if (ip0->protocol == IP_PROTOCOL_UDP) { udp0 = (udp_header_t *) (ip0 + 1); if (dhcp_client_port_network_order == udp0->dst_port) { next0 = DHCP_CLIENT_DETECT_NEXT_EXTRACT; extractions++; } } if (ip1->protocol == IP_PROTOCOL_UDP) { udp1 = (udp_header_t *) (ip1 + 1); if (dhcp_client_port_network_order == udp1->dst_port) { next1 = DHCP_CLIENT_DETECT_NEXT_EXTRACT; extractions++; } } if (ip2->protocol == IP_PROTOCOL_UDP) { udp2 = (udp_header_t *) (ip2 + 1); if (dhcp_client_port_network_order == udp2->dst_port) { next2 = DHCP_CLIENT_DETECT_NEXT_EXTRACT; extractions++; } } if (ip3->protocol == IP_PROTOCOL_UDP) { udp3 = (udp_header_t *) (ip3 + 1); if (dhcp_client_port_network_order == udp3->dst_port) { next3 = DHCP_CLIENT_DETECT_NEXT_EXTRACT; extractions++; } } if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) { dhcp_client_detect_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->extracted = (next0 == DHCP_CLIENT_DETECT_NEXT_EXTRACT); } if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED)) { dhcp_client_detect_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t)); t->extracted = (next1 == DHCP_CLIENT_DETECT_NEXT_EXTRACT); } if (PREDICT_FALSE (b2->flags & VLIB_BUFFER_IS_TRACED)) { dhcp_client_detect_trace_t *t = vlib_add_trace (vm, node, b2, sizeof (*t)); t->extracted = (next2 == DHCP_CLIENT_DETECT_NEXT_EXTRACT); } if (PREDICT_FALSE (b3->flags & VLIB_BUFFER_IS_TRACED)) { dhcp_client_detect_trace_t *t = vlib_add_trace (vm, node, b3, sizeof (*t)); t->extracted = (next3 == DHCP_CLIENT_DETECT_NEXT_EXTRACT); } /* verify speculative enqueue, maybe switch current next frame */ vlib_validate_buffer_enqueue_x4 (vm, node, next_index, to_next, n_left_to_next, bi0, bi1, bi2, bi3, next0, next1, next2, next3); } while (n_left_from > 0 && n_left_to_next > 0) { udp_header_t *udp0; vlib_buffer_t *b0; ip4_header_t *ip0; u32 next0 = ~0; u32 bi0; bi0 = from[0]; to_next[0] = bi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; b0 = vlib_get_buffer (vm, bi0); ip0 = vlib_buffer_get_current (b0); /* * when this feature is applied on an interface that is already * accepting packets (because e.g. the interface has other addresses * assigned) we are looking for the preverbial needle in the haystack * so assume the packet is not the one we are looking for. */ vnet_feature_next (&next0, b0); /* * all we are looking for here is DHCP/BOOTP packet-to-client * UDO port. */ if (ip0->protocol == IP_PROTOCOL_UDP) { udp0 = (udp_header_t *) (ip0 + 1); if (dhcp_client_port_network_order == udp0->dst_port) { next0 = DHCP_CLIENT_DETECT_NEXT_EXTRACT; extractions++; } } if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED)) { dhcp_client_detect_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->extracted = (next0 == DHCP_CLIENT_DETECT_NEXT_EXTRACT); } /* 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); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } vlib_node_increment_counter (vm, node->node_index, DHCP_CLIENT_DETECT_ERROR_EXTRACT, extractions); return frame->n_vectors; } /* packet trace format function */ static u8 * format_dhcp_client_detect_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 *); dhcp_client_detect_trace_t *t = va_arg (*args, dhcp_client_detect_trace_t *); s = format (s, "dhcp-client-detect: %s", (t->extracted ? "yes" : "no")); return s; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (dhcp_client_detect_node) = { .name = "ip4-dhcp-client-detect", .vector_size = sizeof (u32), .format_trace = format_dhcp_client_detect_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(dhcp_client_detect_error_strings), .error_strings = dhcp_client_detect_error_strings, .n_next_nodes = DHCP_CLIENT_DETECT_N_NEXT, .next_nodes = { /* * Jump straight to the UDP dispatch node thus avoiding * the RPF checks in ip4-local that will fail */ [DHCP_CLIENT_DETECT_NEXT_EXTRACT] = "ip4-udp-lookup", }, }; VNET_FEATURE_INIT (ip4_dvr_reinject_feat_node, static) = { .arc_name = "ip4-unicast", .node_name = "ip4-dhcp-client-detect", .runs_before = VNET_FEATURES ("ip4-not-enabled"), }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */