2 * encap.c : L2TPv3 tunnel encapsulation
4 * Copyright (c) 2013 Cisco and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #include <vppinfra/error.h>
19 #include <vppinfra/hash.h>
20 #include <vnet/vnet.h>
21 #include <vnet/ip/ip.h>
22 #include <vnet/ethernet/ethernet.h>
23 #include <vnet/l2tp/l2tp.h>
25 /* Statistics (not really errors) */
26 #define foreach_l2t_encap_error \
27 _(NETWORK_TO_USER, "L2TP L2 network to user (ip6) pkts") \
28 _(LOOKUP_FAIL_TO_L3, "L2TP L2 session lookup failed pkts") \
29 _(ADMIN_DOWN, "L2TP tunnel is down")
31 static char * l2t_encap_error_strings[] = {
32 #define _(sym,string) string,
33 foreach_l2t_encap_error
38 #define _(sym,str) L2T_ENCAP_ERROR_##sym,
39 foreach_l2t_encap_error
47 L2T_ENCAP_NEXT_IP6_LOOKUP,
52 u32 cached_session_index;
53 u32 cached_sw_if_index;
54 vnet_main_t * vnet_main;
55 } l2tp_encap_runtime_t;
57 vlib_node_registration_t l2t_encap_node;
61 static inline void stage0 (vlib_main_t * vm,
62 vlib_node_runtime_t * node,
65 vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
66 vlib_prefetch_buffer_header (b, STORE);
67 CLIB_PREFETCH (b->data, 2*CLIB_CACHE_LINE_BYTES, STORE);
70 static inline void stage1 (vlib_main_t * vm,
71 vlib_node_runtime_t * node,
74 l2tp_encap_runtime_t * rt = (void *) node->runtime_data;
75 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
76 vnet_hw_interface_t * hi;
78 u32 sw_if_index = vnet_buffer(b)->sw_if_index[VLIB_TX];
79 u32 session_index = rt->cached_session_index;
81 if (PREDICT_FALSE(rt->cached_sw_if_index != sw_if_index))
83 hi = vnet_get_sup_hw_interface (rt->vnet_main, sw_if_index);
84 session_index = rt->cached_session_index = hi->dev_instance;
85 rt->cached_sw_if_index = sw_if_index;
88 /* Remember mapping index, prefetch the mini counter */
89 vnet_buffer(b)->l2t.next_index = L2T_ENCAP_NEXT_IP6_LOOKUP;
90 vnet_buffer(b)->l2t.session_index = session_index;
92 /* $$$$ prefetch counter... */
95 static inline u32 last_stage (vlib_main_t *vm, vlib_node_runtime_t *node,
98 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
99 l2t_main_t *lm = &l2t_main;
100 vlib_node_t *n = vlib_get_node (vm, l2t_encap_node.index);
101 u32 node_counter_base_index = n->error_heap_index;
102 vlib_error_main_t * em = &vm->error_main;
103 l2tpv3_header_t * l2tp;
109 u32 next_index = L2T_ENCAP_NEXT_IP6_LOOKUP;
111 /* Other-than-output pkt? We're done... */
112 if (vnet_buffer(b)->l2t.next_index != L2T_ENCAP_NEXT_IP6_LOOKUP)
113 return vnet_buffer(b)->l2t.next_index;
115 /* clear so it is not interpreted as fib_index */
116 vnet_buffer(b)->sw_if_index[VLIB_TX] = (u32)~0;
118 em->counters[node_counter_base_index + L2T_ENCAP_ERROR_NETWORK_TO_USER] += 1;
120 session_index = vnet_buffer(b)->l2t.session_index;
123 session_index_to_counter_index (session_index,
124 SESSION_COUNTER_NETWORK_TO_USER);
126 /* per-mapping byte stats include the ethernet header */
127 vlib_increment_combined_counter (&lm->counter_main,
130 1 /* packet_increment */,
131 vlib_buffer_length_in_chain (vm, b));
133 s = pool_elt_at_index (lm->sessions, session_index);
135 /* Paint on an l2tpv3 hdr */
136 vlib_buffer_advance (b, -(s->l2tp_hdr_size));
137 l2tp = vlib_buffer_get_current (b);
139 l2tp->session_id = s->remote_session_id;
140 l2tp->cookie = s->remote_cookie;
141 if (PREDICT_FALSE (s->l2_sublayer_present)) {
142 l2tp->l2_specific_sublayer = 0;
145 /* Paint on an ip6 header */
146 vlib_buffer_advance (b, -(sizeof (*ip6)));
147 ip6 = vlib_buffer_get_current (b);
149 if (PREDICT_FALSE(!(s->admin_up))) {
150 b->error = node->errors[L2T_ENCAP_ERROR_ADMIN_DOWN];
151 next_index = L2T_ENCAP_NEXT_DROP;
155 ip6->ip_version_traffic_class_and_flow_label =
156 clib_host_to_net_u32 (0x6<<28);
158 /* calculate ip6 payload length */
159 payload_length = vlib_buffer_length_in_chain (vm, b);
160 payload_length -= sizeof (*ip6);
162 ip6->payload_length = clib_host_to_net_u16 (payload_length);
163 ip6->protocol = IP_PROTOCOL_L2TP;
164 ip6->hop_limit = 0xff;
165 ip6->src_address.as_u64[0] = s->our_address.as_u64[0];
166 ip6->src_address.as_u64[1] = s->our_address.as_u64[1];
167 ip6->dst_address.as_u64[0] = s->client_address.as_u64[0];
168 ip6->dst_address.as_u64[1] = s->client_address.as_u64[1];
172 if (PREDICT_FALSE(b->flags & VLIB_BUFFER_IS_TRACED)) {
173 l2t_trace_t *t = vlib_add_trace (vm, node, b, sizeof (*t));
174 t->is_user_to_network = 0;
175 t->our_address.as_u64[0] =
176 ip6->src_address.as_u64[0];
177 t->our_address.as_u64[1] =
178 ip6->src_address.as_u64[1];
179 t->client_address.as_u64[0] =
180 ip6->dst_address.as_u64[0];
181 t->client_address.as_u64[1] =
182 ip6->dst_address.as_u64[1];
183 t->session_index = session_index;
189 #include <vnet/pipeline.h>
191 uword l2t_encap_node_fn (vlib_main_t * vm,
192 vlib_node_runtime_t * node,
193 vlib_frame_t * frame)
195 return dispatch_pipeline (vm, node, frame);
199 VLIB_REGISTER_NODE (l2t_encap_node) = {
200 .function = l2t_encap_node_fn,
201 .name = "l2tp-encap",
202 .vector_size = sizeof (u32),
203 .format_trace = format_l2t_trace,
204 .type = VLIB_NODE_TYPE_INTERNAL,
205 .runtime_data_bytes = sizeof (l2tp_encap_runtime_t),
207 .n_errors = ARRAY_LEN(l2t_encap_error_strings),
208 .error_strings = l2t_encap_error_strings,
210 .n_next_nodes = L2T_ENCAP_N_NEXT,
212 // add dispositions here
214 [L2T_ENCAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
215 [L2T_ENCAP_NEXT_DROP] = "error-drop",
219 VLIB_NODE_FUNCTION_MULTIARCH (l2t_encap_node, l2t_encap_node_fn)
221 void l2tp_encap_init (vlib_main_t * vm)
223 l2tp_encap_runtime_t * rt;
225 rt = vlib_node_get_runtime_data (vm, l2t_encap_node.index);
226 rt->vnet_main = vnet_get_main();
227 rt->cached_sw_if_index = (u32) ~0;
228 rt->cached_session_index = (u32) ~0;