--- /dev/null
+/*
+ * decap.c : L2TPv3 tunnel decapsulation
+ *
+ * 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 <vppinfra/error.h>
+#include <vppinfra/hash.h>
+#include <vnet/vnet.h>
+#include <vnet/ip/ip.h>
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/l2tp/l2tp.h>
+
+/* Statistics (not really errors) */
+#define foreach_l2t_decap_error \
+_(USER_TO_NETWORK, "L2TP user (ip6) to L2 network pkts") \
+_(SESSION_ID_MISMATCH, "l2tpv3 local session id mismatches") \
+_(COOKIE_MISMATCH, "l2tpv3 local cookie mismatches")
+
+static char * l2t_decap_error_strings[] = {
+#define _(sym,string) string,
+ foreach_l2t_decap_error
+#undef _
+};
+
+typedef enum {
+#define _(sym,str) L2T_DECAP_ERROR_##sym,
+ foreach_l2t_decap_error
+#undef _
+ L2T_DECAP_N_ERROR,
+} l2t_DECAP_error_t;
+
+typedef enum {
+ L2T_DECAP_NEXT_DROP,
+ L2T_DECAP_NEXT_L2_INPUT,
+ L2T_DECAP_N_NEXT,
+ /* Pseudo next index */
+ L2T_DECAP_NEXT_NO_INTERCEPT = L2T_DECAP_N_NEXT,
+} l2t_decap_next_t;
+
+#define NSTAGES 3
+
+static inline void stage0 (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ u32 buffer_index)
+{
+ vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
+ vlib_prefetch_buffer_header (b, STORE);
+ /* l2tpv3 header is a long way away, need 2 cache lines */
+ CLIB_PREFETCH (b->data, 2*CLIB_CACHE_LINE_BYTES, STORE);
+}
+
+static inline void stage1 (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ u32 bi)
+{
+ vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+ l2t_main_t *lm = &l2t_main;
+ ip6_header_t * ip6 = vlib_buffer_get_current (b);
+ u32 session_index;
+ uword *p = 0;
+ l2tpv3_header_t * l2t;
+
+ /* Not L2tpv3 (0x73, 0t115)? Use the normal path. */
+ if (PREDICT_FALSE(ip6->protocol != IP_PROTOCOL_L2TP)) {
+ vnet_buffer(b)->l2t.next_index = L2T_DECAP_NEXT_NO_INTERCEPT;
+ return;
+ }
+
+ /* Make up your minds, people... */
+ switch (lm->lookup_type) {
+ case L2T_LOOKUP_SRC_ADDRESS:
+ p = hash_get_mem (lm->session_by_src_address, &ip6->src_address);
+ break;
+ case L2T_LOOKUP_DST_ADDRESS:
+ p = hash_get_mem (lm->session_by_dst_address, &ip6->dst_address);
+ break;
+ case L2T_LOOKUP_SESSION_ID:
+ l2t = (l2tpv3_header_t*)(ip6+1);
+ p = hash_get (lm->session_by_session_id, l2t->session_id);
+ break;
+ default:
+ ASSERT(0);
+ }
+
+ if (PREDICT_FALSE(p == 0)) {
+ vnet_buffer(b)->l2t.next_index = L2T_DECAP_NEXT_NO_INTERCEPT;
+ return;
+ } else {
+ session_index = p[0];
+ }
+
+ /* Remember mapping index, prefetch the mini counter */
+ vnet_buffer(b)->l2t.next_index = L2T_DECAP_NEXT_L2_INPUT;
+ vnet_buffer(b)->l2t.session_index = session_index;
+
+ /* $$$$$ prefetch counter */
+}
+
+static inline u32 last_stage (vlib_main_t *vm, vlib_node_runtime_t *node,
+ u32 bi)
+{
+ vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+ l2t_main_t *lm = &l2t_main;
+ ip6_header_t * ip6 = vlib_buffer_get_current (b);
+ vlib_node_t *n = vlib_get_node (vm, l2t_decap_node.index);
+ u32 node_counter_base_index = n->error_heap_index;
+ vlib_error_main_t * em = &vm->error_main;
+ l2tpv3_header_t * l2tp;
+ u32 counter_index;
+ l2t_session_t * session;
+ u32 session_index;
+ u32 next_index;
+
+ /* Other-than-output pkt? We're done... */
+ if (vnet_buffer(b)->l2t.next_index != L2T_DECAP_NEXT_L2_INPUT) {
+ next_index = vnet_buffer(b)->l2t.next_index;
+ goto done;
+ }
+
+ em->counters[node_counter_base_index + L2T_DECAP_ERROR_USER_TO_NETWORK] += 1;
+
+ session_index = vnet_buffer(b)->l2t.session_index;
+
+ counter_index =
+ session_index_to_counter_index (session_index,
+ SESSION_COUNTER_USER_TO_NETWORK);
+
+ /* per-mapping byte stats include the ethernet header */
+ vlib_increment_combined_counter (&lm->counter_main,
+ os_get_cpu_number(),
+ counter_index,
+ 1 /* packet_increment */,
+ vlib_buffer_length_in_chain (vm, b) +
+ sizeof (ethernet_header_t));
+
+ session = pool_elt_at_index (lm->sessions, session_index);
+
+ l2tp = vlib_buffer_get_current (b) + sizeof (*ip6);
+
+ if (PREDICT_FALSE(l2tp->session_id != session->local_session_id)) {
+ // Key matched but session id does not. Assume packet is not for us.
+ em->counters[node_counter_base_index + L2T_DECAP_ERROR_SESSION_ID_MISMATCH] += 1;
+ next_index = L2T_DECAP_NEXT_NO_INTERCEPT;
+ goto done;
+ }
+
+ if (PREDICT_FALSE (l2tp->cookie != session->local_cookie[0])) {
+ if (l2tp->cookie != session->local_cookie[1]) {
+ // Key and session ID matched, but cookie doesn't. Drop this packet.
+ b->error = node->errors[L2T_DECAP_ERROR_COOKIE_MISMATCH];
+ next_index = L2T_DECAP_NEXT_DROP;
+ goto done;
+ }
+ }
+
+ vnet_buffer(b)->sw_if_index[VLIB_RX] = session->sw_if_index;
+
+ /* strip the ip6 and L2TP header */
+ vlib_buffer_advance (b, sizeof (*ip6) + session->l2tp_hdr_size);
+
+ /* Required to make the l2 tag push / pop code work on l2 subifs */
+ vnet_update_l2_len (b);
+
+ if (PREDICT_FALSE(b->flags & VLIB_BUFFER_IS_TRACED)) {
+ l2t_trace_t *t = vlib_add_trace (vm, node, b, sizeof (*t));
+ t->is_user_to_network = 1;
+ t->our_address.as_u64[0] =
+ ip6->dst_address.as_u64[0];
+ t->our_address.as_u64[1] =
+ ip6->dst_address.as_u64[1];
+ t->client_address.as_u64[0] =
+ ip6->src_address.as_u64[0];
+ t->client_address.as_u64[1] =
+ ip6->src_address.as_u64[1];
+ t->session_index = session_index;
+ }
+
+ return L2T_DECAP_NEXT_L2_INPUT;
+
+ done:
+ if (next_index == L2T_DECAP_NEXT_NO_INTERCEPT) {
+ // Go to next node on the ip6 configuration chain
+ ip6_main_t * im = &ip6_main;
+ ip_lookup_main_t * lm = &im->lookup_main;
+ ip_config_main_t * cm = &lm->rx_config_mains[VNET_UNICAST];
+ ip6_l2tpv3_config_t * c0;
+
+ vnet_get_config_data (&cm->config_main,
+ &vnet_buffer (b)->ip.current_config_index,
+ &next_index,
+ sizeof (c0[0]));
+ }
+
+ if (PREDICT_FALSE(b->flags & VLIB_BUFFER_IS_TRACED)) {
+ l2t_trace_t *t = vlib_add_trace (vm, node, b, sizeof (*t));
+ t->is_user_to_network = 1;
+ t->our_address.as_u64[0] =
+ ip6->dst_address.as_u64[0];
+ t->our_address.as_u64[1] =
+ ip6->dst_address.as_u64[1];
+ t->client_address.as_u64[0] =
+ ip6->src_address.as_u64[0];
+ t->client_address.as_u64[1] =
+ ip6->src_address.as_u64[1];
+ t->session_index = ~0;
+ }
+ return next_index;
+}
+
+#include <vnet/pipeline.h>
+
+static uword l2t_decap_node_fn (vlib_main_t * vm,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame)
+{
+ return dispatch_pipeline (vm, node, frame);
+}
+
+VLIB_REGISTER_NODE (l2t_decap_node) = {
+ .function = l2t_decap_node_fn,
+ .name = "l2tp-decap",
+ .vector_size = sizeof (u32),
+ .format_trace = format_l2t_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+
+ .n_errors = ARRAY_LEN(l2t_decap_error_strings),
+ .error_strings = l2t_decap_error_strings,
+
+ .n_next_nodes = L2T_DECAP_N_NEXT,
+
+ /* edit / add dispositions here */
+ .next_nodes = {
+ [L2T_DECAP_NEXT_L2_INPUT] = "l2-input",
+ [L2T_DECAP_NEXT_DROP] = "error-drop",
+ },
+};
+
+void l2tp_decap_init (void)
+{
+ ip6_register_protocol (IP_PROTOCOL_L2TP, l2t_decap_node.index);
+}
Code Review / vpp.git / blobdiff