/*
* Copyright (c) 2017 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 <nat/dslite.h>
#include <nat/nat_inlines.h>
typedef enum
{
DSLITE_OUT2IN_NEXT_IP4_LOOKUP,
DSLITE_OUT2IN_NEXT_IP6_LOOKUP,
DSLITE_OUT2IN_NEXT_DROP,
DSLITE_OUT2IN_N_NEXT,
} dslite_out2in_next_t;
static char *dslite_out2in_error_strings[] = {
#define _(sym,string) string,
foreach_dslite_error
#undef _
};
static inline u32
dslite_icmp_out2in (dslite_main_t * dm, ip4_header_t * ip4,
dslite_session_t ** sp, u32 next, u8 * error,
u32 thread_index)
{
dslite_session_t *s = 0;
icmp46_header_t *icmp = ip4_next_header (ip4);
clib_bihash_kv_8_8_t kv, value;
snat_session_key_t key;
u32 n = next;
icmp_echo_header_t *echo;
u32 new_addr, old_addr;
u16 old_id, new_id;
ip_csum_t sum;
echo = (icmp_echo_header_t *) (icmp + 1);
if (icmp_is_error_message (icmp) || (icmp->type != ICMP4_echo_reply))
{
n = DSLITE_OUT2IN_NEXT_DROP;
*error = DSLITE_ERROR_BAD_ICMP_TYPE;
goto done;
}
key.addr = ip4->dst_address;
key.port = echo->identifier;
key.protocol = SNAT_PROTOCOL_ICMP;
key.fib_index = 0;
kv.key = key.as_u64;
if (clib_bihash_search_8_8
(&dm->per_thread_data[thread_index].out2in, &kv, &value))
{
next = DSLITE_OUT2IN_NEXT_DROP;
*error = DSLITE_ERROR_NO_TRANSLATION;
goto done;
}
else
{
s =
pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
value.value);
}
old_id = echo->identifier;
echo->identifier = new_id = s->in2out.port;
sum = icmp->checksum;
sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier);
icmp->checksum = ip_csum_fold (sum);
old_addr = ip4->dst_address.as_u32;
ip4->dst_address = s->in2out.addr;
new_addr = ip4->dst_address.as_u32;
sum = ip4->checksum;
sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
ip4->checksum = ip_csum_fold (sum);
done:
*sp = s;
return n;
}
VLIB_NODE_FN (dslite_out2in_node) (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
u32 n_left_from, *from, *to_next;
dslite_out2in_next_t next_index;
vlib_node_runtime_t *error_node;
u32 thread_index = vm->thread_index;
f64 now = vlib_time_now (vm);
dslite_main_t *dm = &dslite_main;
error_node = vlib_node_get_runtime (vm, dm->dslite_out2in_node_index);
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors;
next_index = node->cached_next_index;
while (n_left_from > 0)
{
u32 n_left_to_next;
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_from > 0 && n_left_to_next > 0)
{
u32 bi0;
vlib_buffer_t *b0;
u32 next0 = DSLITE_OUT2IN_NEXT_IP6_LOOKUP;
u8 error0 = DSLITE_ERROR_OUT2IN;
ip4_header_t *ip40;
ip6_header_t *ip60;
u32 proto0;
udp_header_t *udp0;
tcp_header_t *tcp0;
clib_bihash_kv_8_8_t kv0, value0;
snat_session_key_t key0;
dslite_session_t *s0 = 0;
ip_csum_t sum0;
u32 new_addr0, old_addr0;
u16 new_port0, old_port0;
/* speculatively enqueue b0 to the current next frame */
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);
ip40 = vlib_buffer_get_current (b0);
proto0 = ip_proto_to_snat_proto (ip40->protocol);
if (PREDICT_FALSE (proto0 == ~0))
{
error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
next0 = DSLITE_OUT2IN_NEXT_DROP;
goto trace0;
}
if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
{
next0 =
dslite_icmp_out2in (dm, ip40, &s0, next0, &error0,
thread_index);
if (PREDICT_FALSE (next0 == DSLITE_OUT2IN_NEXT_DROP))
goto trace0;
goto encap0;
}
udp0 = ip4_next_header (ip40);
tcp0 = (tcp_header_t *) udp0;
key0.addr = ip40->dst_address;
key0.port = udp0->dst_port;
key0.protocol = proto0;
key0.fib_index = 0;
kv0.key = key0.as_u64;
if (clib_bihash_search_8_8
(&dm->per_thread_data[thread_index].out2in, &kv0, &value0))
{
next0 = DSLITE_OUT2IN_NEXT_DROP;
error0 = DSLITE_ERROR_NO_TRANSLATION;
goto trace0;
}
else
{
s0 =
pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
value0.value);
}
old_addr0 = ip40->dst_address.as_u32;
ip40->dst_address = s0->in2out.addr;
new_addr0 = ip40->dst_address.as_u32;
sum0 = ip40->checksum;
sum0 =
ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
dst_address);
ip40->checksum = ip_csum_fold (sum0);
if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
{
old_port0 = tcp0->dst_port;
tcp0->dst_port = s0->in2out.port;
new_port0 = tcp0->dst_port;
sum0 = tcp0->checksum;
sum0 =
ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
dst_address);
sum0 =
ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
length);
tcp0->checksum = ip_csum_fold (sum0);
}
else
{
old_port0 = udp0->dst_port;
udp0->dst_port = s0->in2out.port;
udp0->checksum = 0;
}
encap0:
/* Construct IPv6 header */
vlib_buffer_advance (b0, -(sizeof (ip6_header_t)));
ip60 = vlib_buffer_get_current (b0);
ip60->ip_version_traffic_class_and_flow_label =
clib_host_to_net_u32 ((6 << 28) + (ip40->tos << 20));
ip60->payload_length = ip40->length;
ip60->protocol = IP_PROTOCOL_IP_IN_IP;
ip60->hop_limit = ip40->ttl;
ip60->src_address.as_u64[0] = dm->aftr_ip6_addr.as_u64[0];
ip60->src_address.as_u64[1] = dm->aftr_ip6_addr.as_u64[1];
ip60->dst_address.as_u64[0] = s0->in2out.softwire_id.as_u64[0];
ip60->dst_address.as_u64[1] = s0->in2out.softwire_id.as_u64[1];
/* Accounting */
s0->last_heard = now;
s0->total_pkts++;
s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
/* Per-B4 LRU list maintenance */
clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
s0->per_b4_index);
clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
s0->per_b4_list_head_index, s0->per_b4_index);
trace0:
if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
&& (b0->flags & VLIB_BUFFER_IS_TRACED)))
{
dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
t->next_index = next0;
t->session_index = ~0;
if (s0)
t->session_index =
s0 - dm->per_thread_data[thread_index].sessions;
}
b0->error = error_node->errors[error0];
/* 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);
}
return frame->n_vectors;
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (dslite_out2in_node) = {
.name = "dslite-out2in",
.vector_size = sizeof (u32),
.format_trace = format_dslite_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
.n_errors = ARRAY_LEN (dslite_out2in_error_strings),
.error_strings = dslite_out2in_error_strings,
.n_next_nodes = DSLITE_OUT2IN_N_NEXT,
/* edit / add dispositions here */
.next_nodes = {
[DSLITE_OUT2IN_NEXT_DROP] = "error-drop",
[DSLITE_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
[DSLITE_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
},
};
/* *INDENT-ON* */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/