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/*
* encap.c : L2TPv3 tunnel encapsulation
*
* 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 <l2tp/l2tp.h>
/* Statistics (not really errors) */
#define foreach_l2t_encap_error \
_(NETWORK_TO_USER, "L2TP L2 network to user (ip6) pkts") \
_(LOOKUP_FAIL_TO_L3, "L2TP L2 session lookup failed pkts") \
_(ADMIN_DOWN, "L2TP tunnel is down")
static char *l2t_encap_error_strings[] = {
#define _(sym,string) string,
foreach_l2t_encap_error
#undef _
};
typedef enum
{
#define _(sym,str) L2T_ENCAP_ERROR_##sym,
foreach_l2t_encap_error
#undef _
L2T_ENCAP_N_ERROR,
} l2t_encap_error_t;
typedef enum
{
L2T_ENCAP_NEXT_DROP,
L2T_ENCAP_NEXT_IP6_LOOKUP,
L2T_ENCAP_N_NEXT,
} l2t_encap_next_t;
typedef struct
{
u32 cached_session_index;
u32 cached_sw_if_index;
vnet_main_t *vnet_main;
} l2tp_encap_runtime_t;
extern vlib_node_registration_t l2t_encap_node;
#define NSTAGES 3
static inline void
stage0 (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b)
{
vlib_prefetch_buffer_header (b, STORE);
CLIB_PREFETCH (b->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
}
static inline void
stage1 (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b)
{
l2tp_encap_runtime_t *rt = (void *) node->runtime_data;
vnet_hw_interface_t *hi;
u32 sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_TX];
u32 session_index = rt->cached_session_index;
if (PREDICT_FALSE (rt->cached_sw_if_index != sw_if_index))
{
hi = vnet_get_sup_hw_interface (rt->vnet_main, sw_if_index);
session_index = rt->cached_session_index = hi->dev_instance;
rt->cached_sw_if_index = sw_if_index;
}
/* Remember mapping index, prefetch the mini counter */
vnet_buffer (b)->l2t.next_index = L2T_ENCAP_NEXT_IP6_LOOKUP;
vnet_buffer (b)->l2t.session_index = session_index;
/* $$$$ prefetch counter... */
}
static inline u32
last_stage (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b)
{
l2t_main_t *lm = &l2t_main;
vlib_node_t *n = vlib_get_node (vm, l2t_encap_node.index);
u32 node_counter_base_index = n->error_heap_index;
vlib_error_main_t *em = &vm->error_main;
l2tpv3_header_t *l2tp;
u32 session_index;
u32 counter_index;
l2t_session_t *s;
ip6_header_t *ip6;
u16 payload_length;
u32 next_index = L2T_ENCAP_NEXT_IP6_LOOKUP;
/* Other-than-output pkt? We're done... */
if (vnet_buffer (b)->l2t.next_index != L2T_ENCAP_NEXT_IP6_LOOKUP)
return vnet_buffer (b)->l2t.next_index;
em->counters[node_counter_base_index + L2T_ENCAP_ERROR_NETWORK_TO_USER] +=
1;
session_index = vnet_buffer (b)->l2t.session_index;
counter_index =
session_index_to_counter_index (session_index,
SESSION_COUNTER_NETWORK_TO_USER);
/* per-mapping byte stats include the ethernet header */
vlib_increment_combined_counter (&lm->counter_main,
vlib_get_thread_index (),
counter_index, 1 /* packet_increment */ ,
vlib_buffer_length_in_chain (vm, b));
s = pool_elt_at_index (lm->sessions, session_index);
vnet_buffer (b)->sw_if_index[VLIB_TX] = s->encap_fib_index;
/* Paint on an l2tpv3 hdr */
vlib_buffer_advance (b, -(s->l2tp_hdr_size));
l2tp = vlib_buffer_get_current (b);
l2tp->session_id = s->remote_session_id;
l2tp->cookie = s->remote_cookie;
if (PREDICT_FALSE (s->l2_sublayer_present))
{
l2tp->l2_specific_sublayer = 0;
}
/* Paint on an ip6 header */
vlib_buffer_advance (b, -(sizeof (*ip6)));
ip6 = vlib_buffer_get_current (b);
if (PREDICT_FALSE (!(s->admin_up)))
{
b->error = node->errors[L2T_ENCAP_ERROR_ADMIN_DOWN];
next_index = L2T_ENCAP_NEXT_DROP;
goto done;
}
ip6->ip_version_traffic_class_and_flow_label =
clib_host_to_net_u32 (0x6 << 28);
/* calculate ip6 payload length */
payload_length = vlib_buffer_length_in_chain (vm, b);
payload_length -= sizeof (*ip6);
ip6->payload_length = clib_host_to_net_u16 (payload_length);
ip6->protocol = IP_PROTOCOL_L2TP;
ip6->hop_limit = 0xff;
ip6->src_address.as_u64[0] = s->our_address.as_u64[0];
ip6->src_address.as_u64[1] = s->our_address.as_u64[1];
ip6->dst_address.as_u64[0] = s->client_address.as_u64[0];
ip6->dst_address.as_u64[1] = s->client_address.as_u64[1];
done:
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 = 0;
t->our_address.as_u64[0] = ip6->src_address.as_u64[0];
t->our_address.as_u64[1] = ip6->src_address.as_u64[1];
t->client_address.as_u64[0] = ip6->dst_address.as_u64[0];
t->client_address.as_u64[1] = ip6->dst_address.as_u64[1];
t->session_index = session_index;
}
return next_index;
}
#include <vnet/pipeline.h>
VLIB_NODE_FN (l2t_encap_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
return dispatch_pipeline (vm, node, frame);
}
VLIB_REGISTER_NODE (l2t_encap_node) = {
.name = "l2tp-encap",
.vector_size = sizeof (u32),
.format_trace = format_l2t_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.runtime_data_bytes = sizeof (l2tp_encap_runtime_t),
.n_errors = ARRAY_LEN(l2t_encap_error_strings),
.error_strings = l2t_encap_error_strings,
.n_next_nodes = L2T_ENCAP_N_NEXT,
/* add dispositions here */
.next_nodes = {
[L2T_ENCAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
[L2T_ENCAP_NEXT_DROP] = "error-drop",
},
};
#ifndef CLIB_MARCH_VARIANT
void
l2tp_encap_init (vlib_main_t * vm)
{
l2tp_encap_runtime_t *rt;
rt = vlib_node_get_runtime_data (vm, l2t_encap_node.index);
rt->vnet_main = vnet_get_main ();
rt->cached_sw_if_index = (u32) ~ 0;
rt->cached_session_index = (u32) ~ 0;
}
#endif /* CLIB_MARCH_VARIANT */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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