--- /dev/null
+/*
+ * 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 <vnet/dhcp/client.h>
+#include <vnet/udp/udp.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;
+
+static uword
+dhcp_client_detect_node_fn (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 receving '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 (vnet_buffer (b0)->sw_if_index[VLIB_TX],
+ &next0, b0);
+ vnet_feature_next (vnet_buffer (b1)->sw_if_index[VLIB_TX],
+ &next1, b1);
+ vnet_feature_next (vnet_buffer (b2)->sw_if_index[VLIB_TX],
+ &next2, b2);
+ vnet_feature_next (vnet_buffer (b3)->sw_if_index[VLIB_TX],
+ &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 (vnet_buffer (b0)->sw_if_index[VLIB_TX],
+ &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) = {
+ .function = dhcp_client_detect_node_fn,
+ .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",
+ },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (dhcp_client_detect_node,
+ dhcp_client_detect_node_fn);
+
+VNET_FEATURE_INIT (ip4_dvr_reinject_feat_node, static) =
+{
+ .arc_name = "ip4-unicast",
+ .node_name = "ip4-dhcp-client-detect",
+ .runs_before = VNET_FEATURES ("ip4-drop"),
+};
+
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
Code Review / vpp.git / blobdiff