FD.io VPP  v20.01-48-g3e0dafb74
Vector Packet Processing
nat66_in2out.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2018 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 /**
16  * @file
17  * @brief NAT66 inside to outside network translation
18  */
19 
20 #include <nat/nat66.h>
21 #include <vnet/ip/ip6_to_ip4.h>
22 #include <vnet/fib/fib_table.h>
23 
24 typedef struct
25 {
29 
30 static u8 *
31 format_nat66_in2out_trace (u8 * s, va_list * args)
32 {
33  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
34  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
35  nat66_in2out_trace_t *t = va_arg (*args, nat66_in2out_trace_t *);
36 
37  s =
38  format (s, "NAT66-in2out: sw_if_index %d, next index %d", t->sw_if_index,
39  t->next_index);
40 
41  return s;
42 }
43 
44 #define foreach_nat66_in2out_error \
45 _(IN2OUT_PACKETS, "good in2out packets processed") \
46 _(NO_TRANSLATION, "no translation") \
47 _(UNKNOWN, "unknown")
48 
49 typedef enum
50 {
51 #define _(sym,str) NAT66_IN2OUT_ERROR_##sym,
53 #undef _
56 
57 static char *nat66_in2out_error_strings[] = {
58 #define _(sym,string) string,
60 #undef _
61 };
62 
63 typedef enum
64 {
69 
70 static inline u8
71 nat66_not_translate (u32 rx_fib_index, ip6_address_t ip6_addr)
72 {
73  nat66_main_t *nm = &nat66_main;
77  fib_prefix_t pfx = {
79  .fp_len = 128,
80  .fp_addr = {
81  .ip6 = ip6_addr,
82  },
83  };
84 
85  fei = fib_table_lookup (rx_fib_index, &pfx);
86  if (FIB_NODE_INDEX_INVALID == fei)
87  return 1;
88  sw_if_index = fib_entry_get_resolving_interface (fei);
89 
90  if (sw_if_index == ~0)
91  {
92  fei = fib_table_lookup (nm->outside_fib_index, &pfx);
93  if (FIB_NODE_INDEX_INVALID == fei)
94  return 1;
95  sw_if_index = fib_entry_get_resolving_interface (fei);
96  }
97 
98  /* *INDENT-OFF* */
99  pool_foreach (i, nm->interfaces,
100  ({
101  /* NAT packet aimed at outside interface */
102  if (nat_interface_is_outside (i) && sw_if_index == i->sw_if_index)
103  return 0;
104  }));
105  /* *INDENT-ON* */
106 
107  return 1;
108 }
109 
113 {
114  u32 n_left_from, *from, *to_next;
115  nat66_in2out_next_t next_index;
116  u32 pkts_processed = 0;
117  u32 thread_index = vm->thread_index;
118  nat66_main_t *nm = &nat66_main;
119 
120  from = vlib_frame_vector_args (frame);
121  n_left_from = frame->n_vectors;
122  next_index = node->cached_next_index;
123 
124  while (n_left_from > 0)
125  {
126  u32 n_left_to_next;
127 
128  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
129 
130  while (n_left_from > 0 && n_left_to_next > 0)
131  {
132  u32 bi0;
133  vlib_buffer_t *b0;
135  ip6_header_t *ip60;
136  u16 l4_offset0, frag_offset0;
137  u8 l4_protocol0;
139  u32 sw_if_index0, fib_index0;
140  udp_header_t *udp0;
141  tcp_header_t *tcp0;
142  icmp46_header_t *icmp0;
143  u16 *checksum0 = 0;
144  ip_csum_t csum0;
145 
146  /* speculatively enqueue b0 to the current next frame */
147  bi0 = from[0];
148  to_next[0] = bi0;
149  from += 1;
150  to_next += 1;
151  n_left_from -= 1;
152  n_left_to_next -= 1;
153 
154  b0 = vlib_get_buffer (vm, bi0);
155  ip60 = vlib_buffer_get_current (b0);
156 
157  if (PREDICT_FALSE
158  (ip6_parse
159  (vm, b0, ip60, b0->current_length, &l4_protocol0, &l4_offset0,
160  &frag_offset0)))
161  {
162  next0 = NAT66_IN2OUT_NEXT_DROP;
163  b0->error = node->errors[NAT66_IN2OUT_ERROR_UNKNOWN];
164  goto trace0;
165  }
166 
167  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
168  fib_index0 =
170  sw_if_index0);
171 
172  if (nat66_not_translate (fib_index0, ip60->dst_address))
173  goto trace0;
174 
175  sm0 = nat66_static_mapping_get (&ip60->src_address, fib_index0, 1);
176  if (PREDICT_FALSE (!sm0))
177  {
178  goto trace0;
179  }
180 
181  if (l4_protocol0 == IP_PROTOCOL_UDP)
182  {
183  udp0 = (udp_header_t *) u8_ptr_add (ip60, l4_offset0);
184  checksum0 = &udp0->checksum;
185  }
186  else if (l4_protocol0 == IP_PROTOCOL_TCP)
187  {
188  tcp0 = (tcp_header_t *) u8_ptr_add (ip60, l4_offset0);
189  checksum0 = &tcp0->checksum;
190  }
191  else if (l4_protocol0 == IP_PROTOCOL_ICMP6)
192  {
193  icmp0 = (icmp46_header_t *) u8_ptr_add (ip60, l4_offset0);
194  checksum0 = &icmp0->checksum;
195  }
196  else
197  goto skip_csum0;
198 
199  csum0 = ip_csum_sub_even (*checksum0, ip60->src_address.as_u64[0]);
200  csum0 = ip_csum_sub_even (csum0, ip60->src_address.as_u64[1]);
201  csum0 = ip_csum_add_even (csum0, sm0->e_addr.as_u64[0]);
202  csum0 = ip_csum_add_even (csum0, sm0->e_addr.as_u64[1]);
203  *checksum0 = ip_csum_fold (csum0);
204 
205  skip_csum0:
206  ip60->src_address.as_u64[0] = sm0->e_addr.as_u64[0];
207  ip60->src_address.as_u64[1] = sm0->e_addr.as_u64[1];
208 
210  thread_index, sm0 - nm->sm, 1,
212  b0));
213 
214  trace0:
215  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
216  && (b0->flags & VLIB_BUFFER_IS_TRACED)))
217  {
219  vlib_add_trace (vm, node, b0, sizeof (*t));
220  t->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
221  t->next_index = next0;
222  }
223 
224  pkts_processed += next0 != NAT66_IN2OUT_NEXT_DROP;
225 
226  /* verify speculative enqueue, maybe switch current next frame */
227  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
228  n_left_to_next, bi0, next0);
229  }
230  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
231  }
232 
234  NAT66_IN2OUT_ERROR_IN2OUT_PACKETS,
235  pkts_processed);
236  return frame->n_vectors;
237 }
238 
239 /* *INDENT-OFF* */
241  .name = "nat66-in2out",
242  .vector_size = sizeof (u32),
243  .format_trace = format_nat66_in2out_trace,
246  .error_strings = nat66_in2out_error_strings,
247  .n_next_nodes = NAT66_IN2OUT_N_NEXT,
248  /* edit / add dispositions here */
249  .next_nodes = {
250  [NAT66_IN2OUT_NEXT_DROP] = "error-drop",
251  [NAT66_IN2OUT_NEXT_IP6_LOOKUP] = "ip6-lookup",
252  },
253 };
254 /* *INDENT-ON* */
255 
256 /*
257  * fd.io coding-style-patch-verification: ON
258  *
259  * Local Variables:
260  * eval: (c-set-style "gnu")
261  * End:
262  */
u32 flags
buffer flags: VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index, VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:124
fib_protocol_t fp_proto
protocol type
Definition: fib_types.h:212
#define CLIB_UNUSED(x)
Definition: clib.h:82
static void vlib_increment_combined_counter(vlib_combined_counter_main_t *cm, u32 thread_index, u32 index, u64 n_packets, u64 n_bytes)
Increment a combined counter.
Definition: counter.h:220
u64 as_u64[2]
Definition: ip6_packet.h:51
u32 fib_table_get_index_for_sw_if_index(fib_protocol_t proto, u32 sw_if_index)
Get the index of the FIB bound to the interface.
Definition: fib_table.c:989
u32 thread_index
Definition: main.h:218
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:113
int i
uword ip_csum_t
Definition: ip_packet.h:244
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:424
#define VLIB_NODE_FN(node)
Definition: node.h:202
static uword vlib_buffer_length_in_chain(vlib_main_t *vm, vlib_buffer_t *b)
Get length in bytes of the buffer chain.
Definition: buffer_funcs.h:366
struct _tcp_header tcp_header_t
ip6_address_t src_address
Definition: ip6_packet.h:307
unsigned char u8
Definition: types.h:56
nat66_in2out_error_t
Definition: nat66_in2out.c:49
nat66_main_t nat66_main
Definition: nat66.c:24
nat66_in2out_next_t
Definition: nat66_in2out.c:63
#define u8_ptr_add(ptr, index)
Definition: ip_types.h:34
#define pool_foreach(VAR, POOL, BODY)
Iterate through pool.
Definition: pool.h:498
vl_api_interface_index_t sw_if_index
Definition: gre.api:59
Aggregate type for a prefix.
Definition: fib_types.h:203
unsigned int u32
Definition: types.h:88
fib_node_index_t fib_table_lookup(u32 fib_index, const fib_prefix_t *prefix)
Perfom a longest prefix match in the non-forwarding table.
Definition: fib_table.c:68
vl_api_fib_path_type_t type
Definition: fib_types.api:123
vlib_error_t error
Error code for buffers to be enqueued to error handler.
Definition: buffer.h:136
unsigned short u16
Definition: types.h:57
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:229
#define PREDICT_FALSE(x)
Definition: clib.h:111
#define vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next0)
Finish enqueueing one buffer forward in the graph.
Definition: buffer_node.h:218
#define vlib_get_next_frame(vm, node, next_index, vectors, n_vectors_left)
Get pointer to next frame vector data by (vlib_node_runtime_t, next_index).
Definition: node_funcs.h:338
vlib_main_t * vm
Definition: in2out_ed.c:1810
vlib_node_registration_t nat66_in2out_node
(constructor) VLIB_REGISTER_NODE (nat66_in2out_node)
Definition: nat66_in2out.c:240
static void vlib_node_increment_counter(vlib_main_t *vm, u32 node_index, u32 counter_index, u64 increment)
Definition: node_funcs.h:1150
u32 fib_entry_get_resolving_interface(fib_node_index_t entry_index)
Definition: fib_entry.c:1458
static u8 nat66_not_translate(u32 rx_fib_index, ip6_address_t ip6_addr)
Definition: nat66_in2out.c:71
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:169
ip6_address_t e_addr
Definition: nat66.h:28
snat_interface_t * interfaces
Interface pool.
Definition: nat66.h:49
u32 fib_node_index_t
A typedef of a node index.
Definition: fib_types.h:30
static char * nat66_in2out_error_strings[]
Definition: nat66_in2out.c:57
#define ARRAY_LEN(x)
Definition: clib.h:62
void vlib_put_next_frame(vlib_main_t *vm, vlib_node_runtime_t *r, u32 next_index, u32 n_vectors_left)
Release pointer to next frame vector data.
Definition: main.c:456
vlib_main_t vlib_node_runtime_t * node
Definition: in2out_ed.c:1810
static ip_csum_t ip_csum_sub_even(ip_csum_t c, ip_csum_t x)
Definition: ip_packet.h:272
IPv6 to IPv4 translation.
static void * vlib_add_trace(vlib_main_t *vm, vlib_node_runtime_t *r, vlib_buffer_t *b, u32 n_data_bytes)
Definition: trace_funcs.h:55
vlib_combined_counter_main_t session_counters
Session counters.
Definition: nat66.h:57
#define foreach_nat66_in2out_error
Definition: nat66_in2out.c:44
#define FIB_NODE_INDEX_INVALID
Definition: fib_types.h:31
u32 outside_fib_index
Definition: nat66.h:63
VLIB buffer representation.
Definition: buffer.h:102
static void * vlib_frame_vector_args(vlib_frame_t *f)
Get pointer to frame vector data.
Definition: node_funcs.h:244
static u8 * format_nat66_in2out_trace(u8 *s, va_list *args)
Definition: nat66_in2out.c:31
#define vnet_buffer(b)
Definition: buffer.h:408
vlib_main_t vlib_node_runtime_t vlib_frame_t * frame
Definition: in2out_ed.c:1811
nat66_static_mapping_t * sm
Static mapping pool.
Definition: nat66.h:51
static_always_inline int ip6_parse(vlib_main_t *vm, vlib_buffer_t *b, const ip6_header_t *ip6, u32 buff_len, u8 *l4_protocol, u16 *l4_offset, u16 *frag_hdr_offset)
Parse some useful information from IPv6 header.
Definition: ip6_to_ip4.h:65
#define VLIB_NODE_FLAG_TRACE
Definition: node.h:302
u32 in2out_node_index
node index
Definition: nat66.h:59
NAT66 global declarations.
nat66_static_mapping_t * nat66_static_mapping_get(ip6_address_t *addr, u32 fib_index, u8 is_local)
Definition: nat66.c:128
static vlib_buffer_t * vlib_get_buffer(vlib_main_t *vm, u32 buffer_index)
Translate buffer index into buffer pointer.
Definition: buffer_funcs.h:85
static u16 ip_csum_fold(ip_csum_t c)
Definition: ip_packet.h:300
Definition: defs.h:46
static ip_csum_t ip_csum_add_even(ip_csum_t c, ip_csum_t x)
Definition: ip_packet.h:255
ip6_address_t dst_address
Definition: ip6_packet.h:307