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/*
* Copyright (c) 2020 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 <vlibmemory/api.h>
#include <cnat/cnat_node.h>
#include <cnat/cnat_inline.h>
#include <cnat/cnat_src_policy.h>
typedef enum cnat_translation_next_t_
{
CNAT_TRANSLATION_NEXT_DROP,
CNAT_TRANSLATION_NEXT_LOOKUP,
CNAT_TRANSLATION_N_NEXT,
} cnat_translation_next_t;
vlib_node_registration_t cnat_vip_ip4_node;
vlib_node_registration_t cnat_vip_ip6_node;
/* CNat sub for NAT behind a fib entry (VIP or interposed real IP) */
static uword
cnat_vip_node_fn (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_buffer_t *b,
cnat_node_ctx_t *ctx, int session_not_found,
cnat_session_t *session)
{
vlib_combined_counter_main_t *cntm = &cnat_translation_counters;
cnat_src_policy_main_t *cspm = &cnat_src_policy_main;
const cnat_translation_t *ct = NULL;
ip4_header_t *ip4 = NULL;
ip_protocol_t iproto;
ip6_header_t *ip6 = NULL;
udp_header_t *udp0;
cnat_client_t *cc;
u16 next0;
index_t cti;
u8 trace_flags = 0;
int rv;
if (AF_IP4 == ctx->af)
{
ip4 = vlib_buffer_get_current (b);
iproto = ip4->protocol;
udp0 = (udp_header_t *) (ip4 + 1);
}
else
{
ip6 = vlib_buffer_get_current (b);
iproto = ip6->protocol;
udp0 = (udp_header_t *) (ip6 + 1);
}
cc = cnat_client_get (vnet_buffer (b)->ip.adj_index[VLIB_TX]);
/* Wrong session key */
if (session->key.cs_proto == 0)
{
/* Dont translate & follow the fib programming */
next0 = cc->cc_parent.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
goto trace;
}
if (!session_not_found)
{
/* session table hit */
cnat_timestamp_update (session->value.cs_ts_index, ctx->now);
if (INDEX_INVALID != session->value.cs_lbi)
{
/* Translate & follow the translation given LB */
next0 = session->value.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
}
else if (session->value.flags & CNAT_SESSION_FLAG_HAS_SNAT)
{
/* The return needs DNAT, so we need an additionnal
* lookup after translation */
next0 = CNAT_TRANSLATION_NEXT_LOOKUP;
}
else
{
/* Translate & follow the fib programming */
next0 = cc->cc_parent.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
}
}
else
{
ct =
cnat_find_translation (cc->parent_cci,
clib_host_to_net_u16 (udp0->dst_port), iproto);
if (NULL == ct)
{
/* Dont translate & Follow the fib programming */
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
next0 = cc->cc_parent.dpoi_next_node;
goto trace;
}
/* New flow, create the sessions */
cnat_ep_trk_t *trk0;
u32 rsession_flags = 0;
u32 dpoi_index = -1;
trk0 = cnat_load_balance (ct, ctx->af, ip4, ip6, &dpoi_index);
if (PREDICT_FALSE (NULL == trk0))
{
/* Dont translate & Follow the fib programming */
vnet_buffer (b)->ip.adj_index[VLIB_TX] = cc->cc_parent.dpoi_index;
next0 = cc->cc_parent.dpoi_next_node;
goto trace;
}
/* add the session */
ip46_address_copy (&session->value.cs_ip[VLIB_TX],
&trk0->ct_ep[VLIB_TX].ce_ip.ip);
if (ip_address_is_zero (&trk0->ct_ep[VLIB_RX].ce_ip))
{
if (AF_IP4 == ctx->af)
ip46_address_set_ip4 (&session->value.cs_ip[VLIB_RX],
&ip4->src_address);
else
ip46_address_set_ip6 (&session->value.cs_ip[VLIB_RX],
&ip6->src_address);
}
else
{
/* We source NAT with the translation */
rsession_flags |= CNAT_SESSION_FLAG_HAS_SNAT;
ip46_address_copy (&session->value.cs_ip[VLIB_RX],
&trk0->ct_ep[VLIB_RX].ce_ip.ip);
}
session->value.cs_port[VLIB_TX] =
clib_host_to_net_u16 (trk0->ct_ep[VLIB_TX].ce_port);
session->value.cs_port[VLIB_RX] =
clib_host_to_net_u16 (trk0->ct_ep[VLIB_RX].ce_port);
session->value.dpoi_next_node = ct->ct_lb.dpoi_next_node;
session->value.cs_lbi = dpoi_index;
session->value.flags = 0;
rv = cspm->vip_policy (vm, b, session, &rsession_flags, ct, ctx);
if (CNAT_SOURCE_ERROR_USE_DEFAULT == rv)
rv = cspm->default_policy (vm, b, session, &rsession_flags, ct, ctx);
if (rv)
{
if (CNAT_SOURCE_ERROR_EXHAUSTED_PORTS == rv)
{
vlib_node_registration_t *node =
(AF_IP4 == ctx->af) ? &cnat_vip_ip4_node : &cnat_vip_ip6_node;
vlib_node_increment_counter (vm, node->index,
CNAT_ERROR_EXHAUSTED_PORTS, 1);
}
next0 = CNAT_TRANSLATION_NEXT_DROP;
goto trace;
}
/* refcnt session in current client */
cnat_client_cnt_session (cc);
cnat_session_create (session, ctx, CNAT_LOCATION_FIB, rsession_flags);
trace_flags |= CNAT_TRACE_SESSION_CREATED;
next0 = ct->ct_lb.dpoi_next_node;
vnet_buffer (b)->ip.adj_index[VLIB_TX] = session->value.cs_lbi;
}
if (AF_IP4 == ctx->af)
cnat_translation_ip4 (session, ip4, udp0, vnet_buffer (b)->oflags);
else
cnat_translation_ip6 (session, ip6, udp0, vnet_buffer (b)->oflags);
if (NULL != ct)
{
cti = ct - cnat_translation_pool;
vlib_increment_combined_counter (cntm, ctx->thread_index, cti, 1,
vlib_buffer_length_in_chain (vm, b));
}
trace:
if (PREDICT_FALSE (ctx->do_trace))
{
trace_flags |= session_not_found ? 0 : CNAT_TRACE_SESSION_FOUND;
cnat_add_trace (vm, node, b, session, ct, trace_flags);
}
return next0;
}
VLIB_NODE_FN (cnat_vip_ip4_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
return cnat_node_inline (vm, node, frame, cnat_vip_node_fn, AF_IP4,
CNAT_LOCATION_FIB, 1 /* do_trace */);
return cnat_node_inline (vm, node, frame, cnat_vip_node_fn, AF_IP4,
CNAT_LOCATION_FIB, 0 /* do_trace */);
}
VLIB_NODE_FN (cnat_vip_ip6_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
return cnat_node_inline (vm, node, frame, cnat_vip_node_fn, AF_IP6,
CNAT_LOCATION_FIB, 1 /* do_trace */);
return cnat_node_inline (vm, node, frame, cnat_vip_node_fn, AF_IP6,
CNAT_LOCATION_FIB, 0 /* do_trace */);
}
VLIB_REGISTER_NODE (cnat_vip_ip4_node) =
{
.name = "ip4-cnat-tx",
.vector_size = sizeof (u32),
.format_trace = format_cnat_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = 0,
.n_next_nodes = CNAT_TRANSLATION_N_NEXT,
.next_nodes =
{
[CNAT_TRANSLATION_NEXT_DROP] = "ip4-drop",
[CNAT_TRANSLATION_NEXT_LOOKUP] = "ip4-lookup",
},
};
VLIB_REGISTER_NODE (cnat_vip_ip6_node) =
{
.name = "ip6-cnat-tx",
.vector_size = sizeof (u32),
.format_trace = format_cnat_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = 0,
.n_next_nodes = CNAT_TRANSLATION_N_NEXT,
.next_nodes =
{
[CNAT_TRANSLATION_NEXT_DROP] = "ip6-drop",
[CNAT_TRANSLATION_NEXT_LOOKUP] = "ip6-lookup",
},
};
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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