FD.io VPP  v19.08.3-2-gbabecb413
Vector Packet Processing
dslite_out2in.c
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1 /*
2  * Copyright (c) 2017 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 #include <nat/dslite.h>
16 #include <nat/nat_inlines.h>
17 
18 typedef enum
19 {
25 
26 static char *dslite_out2in_error_strings[] = {
27 #define _(sym,string) string,
29 #undef _
30 };
31 
32 static inline u32
34  dslite_session_t ** sp, u32 next, u8 * error,
35  u32 thread_index)
36 {
37  dslite_session_t *s = 0;
38  icmp46_header_t *icmp = ip4_next_header (ip4);
41  u32 n = next;
42  icmp_echo_header_t *echo;
43  u32 new_addr, old_addr;
44  u16 old_id, new_id;
45  ip_csum_t sum;
46 
47  echo = (icmp_echo_header_t *) (icmp + 1);
48 
49  if (icmp_is_error_message (icmp) || (icmp->type != ICMP4_echo_reply))
50  {
52  *error = DSLITE_ERROR_BAD_ICMP_TYPE;
53  goto done;
54  }
55 
56  key.addr = ip4->dst_address;
57  key.port = echo->identifier;
58  key.protocol = SNAT_PROTOCOL_ICMP;
59  key.fib_index = 0;
60  kv.key = key.as_u64;
61 
62  if (clib_bihash_search_8_8
63  (&dm->per_thread_data[thread_index].out2in, &kv, &value))
64  {
66  *error = DSLITE_ERROR_NO_TRANSLATION;
67  goto done;
68  }
69  else
70  {
71  s =
72  pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
73  value.value);
74  }
75 
76  old_id = echo->identifier;
77  echo->identifier = new_id = s->in2out.port;
78  sum = icmp->checksum;
79  sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier);
80  icmp->checksum = ip_csum_fold (sum);
81 
82  old_addr = ip4->dst_address.as_u32;
83  ip4->dst_address = s->in2out.addr;
84  new_addr = ip4->dst_address.as_u32;
85 
86  sum = ip4->checksum;
87  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
88  ip4->checksum = ip_csum_fold (sum);
89 
90 done:
91  *sp = s;
92  return n;
93 }
94 
96  vlib_node_runtime_t * node,
97  vlib_frame_t * frame)
98 {
99  u32 n_left_from, *from, *to_next;
100  dslite_out2in_next_t next_index;
101  vlib_node_runtime_t *error_node;
102  u32 thread_index = vm->thread_index;
103  f64 now = vlib_time_now (vm);
104  dslite_main_t *dm = &dslite_main;
105 
106  error_node = vlib_node_get_runtime (vm, dm->dslite_out2in_node_index);
107 
108  from = vlib_frame_vector_args (frame);
109  n_left_from = frame->n_vectors;
110  next_index = node->cached_next_index;
111 
112 
113  while (n_left_from > 0)
114  {
115  u32 n_left_to_next;
116 
117  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
118 
119  while (n_left_from > 0 && n_left_to_next > 0)
120  {
121  u32 bi0;
122  vlib_buffer_t *b0;
124  u8 error0 = DSLITE_ERROR_OUT2IN;
125  ip4_header_t *ip40;
126  ip6_header_t *ip60;
127  u32 proto0;
128  udp_header_t *udp0;
129  tcp_header_t *tcp0;
130  clib_bihash_kv_8_8_t kv0, value0;
131  snat_session_key_t key0;
132  dslite_session_t *s0 = 0;
133  ip_csum_t sum0;
134  u32 new_addr0, old_addr0;
135  u16 new_port0, old_port0;
136 
137  /* speculatively enqueue b0 to the current next frame */
138  bi0 = from[0];
139  to_next[0] = bi0;
140  from += 1;
141  to_next += 1;
142  n_left_from -= 1;
143  n_left_to_next -= 1;
144 
145  b0 = vlib_get_buffer (vm, bi0);
146  ip40 = vlib_buffer_get_current (b0);
147  proto0 = ip_proto_to_snat_proto (ip40->protocol);
148 
149  if (PREDICT_FALSE (proto0 == ~0))
150  {
151  error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
152  next0 = DSLITE_OUT2IN_NEXT_DROP;
153  goto trace0;
154  }
155 
156  if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
157  {
158  next0 =
159  dslite_icmp_out2in (dm, ip40, &s0, next0, &error0,
160  thread_index);
161  if (PREDICT_FALSE (next0 == DSLITE_OUT2IN_NEXT_DROP))
162  goto trace0;
163 
164  goto encap0;
165  }
166 
167  udp0 = ip4_next_header (ip40);
168  tcp0 = (tcp_header_t *) udp0;
169 
170  key0.addr = ip40->dst_address;
171  key0.port = udp0->dst_port;
172  key0.protocol = proto0;
173  key0.fib_index = 0;
174  kv0.key = key0.as_u64;
175 
176  if (clib_bihash_search_8_8
177  (&dm->per_thread_data[thread_index].out2in, &kv0, &value0))
178  {
179  next0 = DSLITE_OUT2IN_NEXT_DROP;
180  error0 = DSLITE_ERROR_NO_TRANSLATION;
181  goto trace0;
182  }
183  else
184  {
185  s0 =
186  pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
187  value0.value);
188  }
189 
190  old_addr0 = ip40->dst_address.as_u32;
191  ip40->dst_address = s0->in2out.addr;
192  new_addr0 = ip40->dst_address.as_u32;
193 
194  sum0 = ip40->checksum;
195  sum0 =
196  ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
197  dst_address);
198  ip40->checksum = ip_csum_fold (sum0);
199 
200  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
201  {
202  old_port0 = tcp0->dst_port;
203  tcp0->dst_port = s0->in2out.port;
204  new_port0 = tcp0->dst_port;
205 
206  sum0 = tcp0->checksum;
207  sum0 =
208  ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
209  dst_address);
210  sum0 =
211  ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
212  length);
213  tcp0->checksum = ip_csum_fold (sum0);
214  }
215  else
216  {
217  old_port0 = udp0->dst_port;
218  udp0->dst_port = s0->in2out.port;
219  udp0->checksum = 0;
220  }
221 
222  encap0:
223  /* Construct IPv6 header */
224  vlib_buffer_advance (b0, -(sizeof (ip6_header_t)));
225  ip60 = vlib_buffer_get_current (b0);
227  clib_host_to_net_u32 ((6 << 28) + (ip40->tos << 20));
228  ip60->payload_length = ip40->length;
229  ip60->protocol = IP_PROTOCOL_IP_IN_IP;
230  ip60->hop_limit = ip40->ttl;
231  ip60->src_address.as_u64[0] = dm->aftr_ip6_addr.as_u64[0];
232  ip60->src_address.as_u64[1] = dm->aftr_ip6_addr.as_u64[1];
233  ip60->dst_address.as_u64[0] = s0->in2out.softwire_id.as_u64[0];
234  ip60->dst_address.as_u64[1] = s0->in2out.softwire_id.as_u64[1];
235 
236  /* Accounting */
237  s0->last_heard = now;
238  s0->total_pkts++;
239  s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
240  /* Per-B4 LRU list maintenance */
241  clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
242  s0->per_b4_index);
243  clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
244  s0->per_b4_list_head_index, s0->per_b4_index);
245  trace0:
246  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
247  && (b0->flags & VLIB_BUFFER_IS_TRACED)))
248  {
249  dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
250  t->next_index = next0;
251  t->session_index = ~0;
252  if (s0)
253  t->session_index =
254  s0 - dm->per_thread_data[thread_index].sessions;
255  }
256 
257  b0->error = error_node->errors[error0];
258 
259  /* verify speculative enqueue, maybe switch current next frame */
260  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
261  n_left_to_next, bi0, next0);
262  }
263  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
264  }
265 
266  return frame->n_vectors;
267 }
268 
269 /* *INDENT-OFF* */
271  .name = "dslite-out2in",
272  .vector_size = sizeof (u32),
273  .format_trace = format_dslite_trace,
276  .error_strings = dslite_out2in_error_strings,
277  .n_next_nodes = DSLITE_OUT2IN_N_NEXT,
278  /* edit / add dispositions here */
279  .next_nodes = {
280  [DSLITE_OUT2IN_NEXT_DROP] = "error-drop",
281  [DSLITE_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
282  [DSLITE_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
283  },
284 };
285 /* *INDENT-ON* */
286 
287 /*
288  * fd.io coding-style-patch-verification: ON
289  *
290  * Local Variables:
291  * eval: (c-set-style "gnu")
292  * End:
293  */
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
dslite_out2in_next_t
Definition: dslite_out2in.c:18
u8 * format_dslite_trace(u8 *s, va_list *args)
Definition: dslite.c:241
#define PREDICT_TRUE(x)
Definition: clib.h:113
u64 as_u64[2]
Definition: ip6_packet.h:51
static_always_inline u8 icmp_is_error_message(icmp46_header_t *icmp)
Definition: nat_inlines.h:174
static f64 vlib_time_now(vlib_main_t *vm)
Definition: main.h:279
u32 thread_index
Definition: main.h:218
uword ip_csum_t
Definition: ip_packet.h:219
#define VLIB_NODE_FN(node)
Definition: node.h:202
vlib_error_t * errors
Vector of errors for this node.
Definition: node.h:470
u32 session_index
Definition: dslite.h:107
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:383
unsigned char u8
Definition: types.h:56
double f64
Definition: types.h:142
ip4_address_t dst_address
Definition: ip4_packet.h:170
static void * ip4_next_header(ip4_header_t *i)
Definition: ip4_packet.h:241
unsigned int u32
Definition: types.h:88
dlist_elt_t * list_pool
Definition: dslite.h:75
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
clib_bihash_8_8_t out2in
Definition: dslite.h:62
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:514
u64 key
the key
Definition: bihash_8_8.h:35
static void clib_dlist_addtail(dlist_elt_t *pool, u32 head_index, u32 new_index)
Definition: dlist.h:43
unsigned short u16
Definition: types.h:57
u16 protocol
Definition: nat.h:94
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:112
#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
u64 value
the value
Definition: bihash_8_8.h:36
ip6_address_t aftr_ip6_addr
Definition: dslite.h:80
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:169
vlib_main_t * vm
Definition: buffer.c:323
static vlib_node_runtime_t * vlib_node_get_runtime(vlib_main_t *vm, u32 node_index)
Get node runtime by node index.
Definition: node_funcs.h:89
dslite_main_t dslite_main
Definition: dslite.c:19
8 octet key, 8 octet key value pair
Definition: bihash_8_8.h:33
#define ARRAY_LEN(x)
Definition: clib.h:63
ip4_address_t addr
Definition: nat.h:92
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
static char * dslite_out2in_error_strings[]
Definition: dslite_out2in.c:26
u8 value
Definition: qos.api:53
ip_dscp_t tos
Definition: ip4_packet.h:141
static void vlib_buffer_advance(vlib_buffer_t *b, word l)
Advance current data pointer by the supplied (signed!) amount.
Definition: buffer.h:248
static void clib_dlist_remove(dlist_elt_t *pool, u32 index)
Definition: dlist.h:99
dslite_per_thread_data_t * per_thread_data
Definition: dslite.h:84
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
u32 ip_version_traffic_class_and_flow_label
Definition: ip6_packet.h:370
u16 payload_length
Definition: ip6_packet.h:374
static u32 ip_proto_to_snat_proto(u8 ip_proto)
Definition: nat_inlines.h:147
u32 next_index
Definition: dslite.h:106
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
typedef key
Definition: ipsec.api:247
#define ip_csum_update(sum, old, new, type, field)
Definition: ip_packet.h:269
vlib_node_registration_t dslite_out2in_node
(constructor) VLIB_REGISTER_NODE (dslite_out2in_node)
static u32 dslite_icmp_out2in(dslite_main_t *dm, ip4_header_t *ip4, dslite_session_t **sp, u32 next, u8 *error, u32 thread_index)
Definition: dslite_out2in.c:33
dslite_session_t * sessions
Definition: dslite.h:72
#define foreach_dslite_error
Definition: dslite.h:115
#define VLIB_NODE_FLAG_TRACE
Definition: node.h:302
u32 dslite_out2in_node_index
Definition: dslite.h:97
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:275
u16 fib_index
Definition: nat.h:94
ip6_address_t dst_address
Definition: ip6_packet.h:383