FD.io VPP  v20.01-48-g3e0dafb74
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_type_is_error_message (icmp->type)
50  || (icmp->type != ICMP4_echo_reply))
51  {
53  *error = DSLITE_ERROR_BAD_ICMP_TYPE;
54  goto done;
55  }
56 
57  key.addr = ip4->dst_address;
58  key.port = echo->identifier;
59  key.protocol = SNAT_PROTOCOL_ICMP;
60  key.fib_index = 0;
61  kv.key = key.as_u64;
62 
63  if (clib_bihash_search_8_8
64  (&dm->per_thread_data[thread_index].out2in, &kv, &value))
65  {
67  *error = DSLITE_ERROR_NO_TRANSLATION;
68  goto done;
69  }
70  else
71  {
72  s =
73  pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
74  value.value);
75  }
76 
77  old_id = echo->identifier;
78  echo->identifier = new_id = s->in2out.port;
79  sum = icmp->checksum;
80  sum = ip_csum_update (sum, old_id, new_id, icmp_echo_header_t, identifier);
81  icmp->checksum = ip_csum_fold (sum);
82 
83  old_addr = ip4->dst_address.as_u32;
84  ip4->dst_address = s->in2out.addr;
85  new_addr = ip4->dst_address.as_u32;
86 
87  sum = ip4->checksum;
88  sum = ip_csum_update (sum, old_addr, new_addr, ip4_header_t, dst_address);
89  ip4->checksum = ip_csum_fold (sum);
90 
91 done:
92  *sp = s;
93  return n;
94 }
95 
99 {
100  u32 n_left_from, *from, *to_next;
101  dslite_out2in_next_t next_index;
102  vlib_node_runtime_t *error_node;
103  u32 thread_index = vm->thread_index;
104  f64 now = vlib_time_now (vm);
105  dslite_main_t *dm = &dslite_main;
106 
107  error_node = vlib_node_get_runtime (vm, dm->dslite_out2in_node_index);
108 
109  from = vlib_frame_vector_args (frame);
110  n_left_from = frame->n_vectors;
111  next_index = node->cached_next_index;
112 
113 
114  while (n_left_from > 0)
115  {
116  u32 n_left_to_next;
117 
118  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
119 
120  while (n_left_from > 0 && n_left_to_next > 0)
121  {
122  u32 bi0;
123  vlib_buffer_t *b0;
125  u8 error0 = DSLITE_ERROR_OUT2IN;
126  ip4_header_t *ip40;
127  ip6_header_t *ip60;
128  u32 proto0;
129  udp_header_t *udp0;
130  tcp_header_t *tcp0;
131  clib_bihash_kv_8_8_t kv0, value0;
132  snat_session_key_t key0;
133  dslite_session_t *s0 = 0;
134  ip_csum_t sum0;
135  u32 new_addr0, old_addr0;
136  u16 new_port0, old_port0;
137 
138  /* speculatively enqueue b0 to the current next frame */
139  bi0 = from[0];
140  to_next[0] = bi0;
141  from += 1;
142  to_next += 1;
143  n_left_from -= 1;
144  n_left_to_next -= 1;
145 
146  b0 = vlib_get_buffer (vm, bi0);
147  ip40 = vlib_buffer_get_current (b0);
148  proto0 = ip_proto_to_snat_proto (ip40->protocol);
149 
150  if (PREDICT_FALSE (proto0 == ~0))
151  {
152  error0 = DSLITE_ERROR_UNSUPPORTED_PROTOCOL;
153  next0 = DSLITE_OUT2IN_NEXT_DROP;
154  goto trace0;
155  }
156 
157  if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP))
158  {
159  next0 =
160  dslite_icmp_out2in (dm, ip40, &s0, next0, &error0,
161  thread_index);
162  if (PREDICT_FALSE (next0 == DSLITE_OUT2IN_NEXT_DROP))
163  goto trace0;
164 
165  goto encap0;
166  }
167 
168  udp0 = ip4_next_header (ip40);
169  tcp0 = (tcp_header_t *) udp0;
170 
171  key0.addr = ip40->dst_address;
172  key0.port = udp0->dst_port;
173  key0.protocol = proto0;
174  key0.fib_index = 0;
175  kv0.key = key0.as_u64;
176 
177  if (clib_bihash_search_8_8
178  (&dm->per_thread_data[thread_index].out2in, &kv0, &value0))
179  {
180  next0 = DSLITE_OUT2IN_NEXT_DROP;
181  error0 = DSLITE_ERROR_NO_TRANSLATION;
182  goto trace0;
183  }
184  else
185  {
186  s0 =
187  pool_elt_at_index (dm->per_thread_data[thread_index].sessions,
188  value0.value);
189  }
190 
191  old_addr0 = ip40->dst_address.as_u32;
192  ip40->dst_address = s0->in2out.addr;
193  new_addr0 = ip40->dst_address.as_u32;
194 
195  sum0 = ip40->checksum;
196  sum0 =
197  ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
198  dst_address);
199  ip40->checksum = ip_csum_fold (sum0);
200 
201  if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP))
202  {
203  old_port0 = tcp0->dst_port;
204  tcp0->dst_port = s0->in2out.port;
205  new_port0 = tcp0->dst_port;
206 
207  sum0 = tcp0->checksum;
208  sum0 =
209  ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
210  dst_address);
211  sum0 =
212  ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
213  length);
214  tcp0->checksum = ip_csum_fold (sum0);
215  }
216  else
217  {
218  old_port0 = udp0->dst_port;
219  udp0->dst_port = s0->in2out.port;
220  udp0->checksum = 0;
221  }
222 
223  encap0:
224  /* Construct IPv6 header */
225  vlib_buffer_advance (b0, -(sizeof (ip6_header_t)));
226  ip60 = vlib_buffer_get_current (b0);
228  clib_host_to_net_u32 ((6 << 28) + (ip40->tos << 20));
229  ip60->payload_length = ip40->length;
230  ip60->protocol = IP_PROTOCOL_IP_IN_IP;
231  ip60->hop_limit = ip40->ttl;
232  ip60->src_address.as_u64[0] = dm->aftr_ip6_addr.as_u64[0];
233  ip60->src_address.as_u64[1] = dm->aftr_ip6_addr.as_u64[1];
234  ip60->dst_address.as_u64[0] = s0->in2out.softwire_id.as_u64[0];
235  ip60->dst_address.as_u64[1] = s0->in2out.softwire_id.as_u64[1];
236 
237  /* Accounting */
238  s0->last_heard = now;
239  s0->total_pkts++;
240  s0->total_bytes += vlib_buffer_length_in_chain (vm, b0);
241  /* Per-B4 LRU list maintenance */
242  clib_dlist_remove (dm->per_thread_data[thread_index].list_pool,
243  s0->per_b4_index);
244  clib_dlist_addtail (dm->per_thread_data[thread_index].list_pool,
245  s0->per_b4_list_head_index, s0->per_b4_index);
246  trace0:
247  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
248  && (b0->flags & VLIB_BUFFER_IS_TRACED)))
249  {
250  dslite_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t));
251  t->next_index = next0;
252  t->session_index = ~0;
253  if (s0)
254  t->session_index =
255  s0 - dm->per_thread_data[thread_index].sessions;
256  }
257 
258  b0->error = error_node->errors[error0];
259 
260  /* verify speculative enqueue, maybe switch current next frame */
261  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
262  n_left_to_next, bi0, next0);
263  }
264  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
265  }
266 
267  return frame->n_vectors;
268 }
269 
270 /* *INDENT-OFF* */
272  .name = "dslite-out2in",
273  .vector_size = sizeof (u32),
274  .format_trace = format_dslite_trace,
277  .error_strings = dslite_out2in_error_strings,
278  .n_next_nodes = DSLITE_OUT2IN_N_NEXT,
279  /* edit / add dispositions here */
280  .next_nodes = {
281  [DSLITE_OUT2IN_NEXT_DROP] = "error-drop",
282  [DSLITE_OUT2IN_NEXT_IP4_LOOKUP] = "ip4-lookup",
283  [DSLITE_OUT2IN_NEXT_IP6_LOOKUP] = "ip6-lookup",
284  },
285 };
286 /* *INDENT-ON* */
287 
288 /*
289  * fd.io coding-style-patch-verification: ON
290  *
291  * Local Variables:
292  * eval: (c-set-style "gnu")
293  * End:
294  */
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:112
u64 as_u64[2]
Definition: ip6_packet.h:51
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:244
#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:307
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:519
static_always_inline u8 icmp_type_is_error_message(u8 icmp_type)
Definition: nat_inlines.h:174
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:92
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
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
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:62
ip4_address_t addr
Definition: nat.h:90
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
vlib_main_t vlib_node_runtime_t * node
Definition: in2out_ed.c:1810
u8 value
Definition: qos.api:54
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
typedef key
Definition: ipsec_types.api:83
u32 ip_version_traffic_class_and_flow_label
Definition: ip6_packet.h:294
u16 payload_length
Definition: ip6_packet.h:298
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
#define ip_csum_update(sum, old, new, type, field)
Definition: ip_packet.h:294
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
vlib_main_t vlib_node_runtime_t vlib_frame_t * frame
Definition: in2out_ed.c:1811
#define foreach_dslite_error
Definition: dslite.h:115
u32 ip4
Definition: one.api:440
#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:300
u16 fib_index
Definition: nat.h:92
ip6_address_t dst_address
Definition: ip6_packet.h:307