FD.io VPP  v20.09-64-g4f7b92f0a
Vector Packet Processing
udp.h
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1 /*
2  * Copyright (c) 2017-2020 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 #ifndef __included_udp_h__
16 #define __included_udp_h__
17 
18 #include <vnet/vnet.h>
19 #include <vnet/udp/udp_packet.h>
20 #include <vnet/ip/ip.h>
21 #include <vnet/ip/ip4.h>
22 #include <vnet/ip/ip4_packet.h>
23 #include <vnet/pg/pg.h>
24 #include <vnet/ip/format.h>
25 
26 #include <vnet/ip/ip.h>
27 #include <vnet/session/transport.h>
28 
29 typedef enum
30 {
31 #define udp_error(n,s) UDP_ERROR_##n,
32 #include <vnet/udp/udp_error.def>
33 #undef udp_error
35 } udp_error_t;
36 
37 #define foreach_udp_connection_flag \
38  _(CONNECTED, "CONNECTED") /**< connected mode */ \
39  _(OWNS_PORT, "OWNS_PORT") /**< port belong to conn (UDPC) */ \
40  _(CLOSING, "CLOSING") /**< conn closed with data */ \
41  _(LISTEN, "LISTEN") /**< conn is listening */ \
42  _(MIGRATED, "MIGRATED") /**< cloned to another thread */ \
43 
45 {
46 #define _(sym, str) UDP_CONN_F_BIT_##sym,
48 #undef _
50 };
51 
52 typedef enum udp_conn_flags_
53 {
54 #define _(sym, str) UDP_CONN_F_##sym = 1 << UDP_CONN_F_BIT_##sym,
56 #undef _
58 
59 typedef struct
60 {
61  /** Required for pool_get_aligned */
62  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
63  transport_connection_t connection; /**< must be first */
64  clib_spinlock_t rx_lock; /**< rx fifo lock */
65  u8 flags; /**< connection flags */
66  u16 mss; /**< connection mss */
68 
69 #define foreach_udp4_dst_port \
70 _ (53, dns) \
71 _ (67, dhcp_to_server) \
72 _ (68, dhcp_to_client) \
73 _ (500, ikev2) \
74 _ (2152, GTPU) \
75 _ (3784, bfd4) \
76 _ (3785, bfd_echo4) \
77 _ (4341, lisp_gpe) \
78 _ (4342, lisp_cp) \
79 _ (4500, ipsec) \
80 _ (4739, ipfix) \
81 _ (4789, vxlan) \
82 _ (4789, vxlan6) \
83 _ (48879, vxlan_gbp) \
84 _ (4790, VXLAN_GPE) \
85 _ (6633, vpath_3) \
86 _ (6081, geneve) \
87 _ (53053, dns_reply)
88 
89 
90 #define foreach_udp6_dst_port \
91 _ (53, dns6) \
92 _ (547, dhcpv6_to_server) \
93 _ (546, dhcpv6_to_client) \
94 _ (2152, GTPU6) \
95 _ (3784, bfd6) \
96 _ (3785, bfd_echo6) \
97 _ (4341, lisp_gpe6) \
98 _ (4342, lisp_cp6) \
99 _ (48879, vxlan6_gbp) \
100 _ (4790, VXLAN6_GPE) \
101 _ (6633, vpath6_3) \
102 _ (6081, geneve6) \
103 _ (8138, BIER) \
104 _ (53053, dns_reply6)
105 
106 typedef enum
107 {
108 #define _(n,f) UDP_DST_PORT_##f = n,
110 #undef _
112 
113 typedef enum
114 {
115 #define _(n,f) UDP6_DST_PORT_##f = n,
117 #undef _
119 
120 typedef struct
121 {
122  /* Name (a c string). */
123  char *name;
125  /* Port number in host byte order. */
128  /* Node which handles this type. */
129  u32 node_index;
131  /* Next index for this type. */
132  u32 next_index;
134  /* UDP sessions refcount (not tunnels) */
135  u32 n_connections;
137  /* Parser for packet generator edits for this protocol */
140 
141 typedef enum
142 {
143  UDP_IP6 = 0,
144  UDP_IP4, /* the code is full of is_ip4... */
147 
148 typedef struct
149 {
150  udp_dst_port_info_t *dst_port_infos[N_UDP_AF];
152  /* Hash tables mapping name/protocol to protocol info index. */
153  uword *dst_port_info_by_name[N_UDP_AF];
154  uword *dst_port_info_by_dst_port[N_UDP_AF];
156  /* Sparse vector mapping udp dst_port in network byte order
157  to next index. */
158  u16 *next_by_dst_port4;
159  u16 *next_by_dst_port6;
160  u8 punt_unknown4;
161  u8 punt_unknown6;
163  /* Udp local to input arc index */
164  u32 local_to_input_edge[N_UDP_AF];
166  /*
167  * Per-worker thread udp connection pools used with session layer
168  */
170  u32 *connection_peekers;
171  clib_spinlock_t *peekers_readers_locks;
172  clib_spinlock_t *peekers_write_locks;
173  udp_connection_t *listener_pool;
175  u16 default_mtu;
177 
178 extern udp_main_t udp_main;
183 
185 udp_connection_get (u32 conn_index, u32 thread_index)
186 {
187  if (pool_is_free_index (udp_main.connections[thread_index], conn_index))
188  return 0;
189  return pool_elt_at_index (udp_main.connections[thread_index], conn_index);
190 }
191 
193 udp_listener_get (u32 conn_index)
194 {
195  return pool_elt_at_index (udp_main.listener_pool, conn_index);
196 }
197 
200 {
201  return &udp_main;
202 }
203 
206 {
207  return ((udp_connection_t *) tc);
208 }
209 
212 {
213  return (uc - udp_main.connections[uc->c_thread_index]);
214 }
215 
218 
219 /**
220  * Acquires a lock that blocks a connection pool from expanding.
221  */
222 always_inline void
223 udp_pool_add_peeker (u32 thread_index)
224 {
225  if (thread_index != vlib_get_thread_index ())
226  return;
227  clib_spinlock_lock_if_init (&udp_main.peekers_readers_locks[thread_index]);
228  udp_main.connection_peekers[thread_index] += 1;
229  if (udp_main.connection_peekers[thread_index] == 1)
230  clib_spinlock_lock_if_init (&udp_main.peekers_write_locks[thread_index]);
232  [thread_index]);
233 }
234 
235 always_inline void
236 udp_pool_remove_peeker (u32 thread_index)
237 {
238  if (thread_index != vlib_get_thread_index ())
239  return;
240  ASSERT (udp_main.connection_peekers[thread_index] > 0);
241  clib_spinlock_lock_if_init (&udp_main.peekers_readers_locks[thread_index]);
242  udp_main.connection_peekers[thread_index] -= 1;
243  if (udp_main.connection_peekers[thread_index] == 0)
245  [thread_index]);
247  [thread_index]);
248 }
249 
251 udp_connection_clone_safe (u32 connection_index, u32 thread_index)
252 {
253  udp_connection_t *old_c, *new_c;
254  u32 current_thread_index = vlib_get_thread_index ();
255  new_c = udp_connection_alloc (current_thread_index);
256 
257  /* If during the memcpy pool is reallocated AND the memory allocator
258  * decides to give the old chunk of memory to somebody in a hurry to
259  * scribble something on it, we have a problem. So add this thread as
260  * a session pool peeker.
261  */
262  udp_pool_add_peeker (thread_index);
263  old_c = udp_main.connections[thread_index] + connection_index;
264  clib_memcpy_fast (new_c, old_c, sizeof (*new_c));
265  old_c->flags |= UDP_CONN_F_MIGRATED;
266  udp_pool_remove_peeker (thread_index);
267  new_c->c_thread_index = current_thread_index;
268  new_c->c_c_index = udp_connection_index (new_c);
269  new_c->c_fib_index = old_c->c_fib_index;
270  return new_c;
271 }
272 
275 {
276  uword *p = hash_get (um->dst_port_info_by_dst_port[is_ip4], dst_port);
277  return p ? vec_elt_at_index (um->dst_port_infos[is_ip4], p[0]) : 0;
278 }
279 
287  char *dst_port_name, u8 is_ip4);
290  u32 node_index, u8 is_ip4);
292  udp_dst_port_t dst_port, u8 is_ip4);
294 void udp_connection_share_port (u16 lcl_port, u8 is_ip4);
295 
296 void udp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);
297 
298 always_inline void *
299 vlib_buffer_push_udp (vlib_buffer_t * b, u16 sp, u16 dp, u8 offload_csum)
300 {
301  udp_header_t *uh;
302  u16 udp_len = sizeof (udp_header_t) + b->current_length;
303  if (PREDICT_FALSE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID))
305 
306  uh = vlib_buffer_push_uninit (b, sizeof (udp_header_t));
307  uh->src_port = sp;
308  uh->dst_port = dp;
309  uh->checksum = 0;
310  uh->length = clib_host_to_net_u16 (udp_len);
311  if (offload_csum)
312  b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
313  vnet_buffer (b)->l4_hdr_offset = (u8 *) uh - b->data;
314  b->flags |= VNET_BUFFER_F_L4_HDR_OFFSET_VALID;
315  return uh;
316 }
317 
318 always_inline void
319 ip_udp_fixup_one (vlib_main_t * vm, vlib_buffer_t * b0, u8 is_ip4)
320 {
321  u16 new_l0;
322  udp_header_t *udp0;
323 
324  if (is_ip4)
325  {
326  ip4_header_t *ip0;
327  ip_csum_t sum0;
328  u16 old_l0 = 0;
329 
330  ip0 = vlib_buffer_get_current (b0);
331 
332  /* fix the <bleep>ing outer-IP checksum */
333  sum0 = ip0->checksum;
334  /* old_l0 always 0, see the rewrite setup */
335  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
336 
337  sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
338  length /* changed member */ );
339  ip0->checksum = ip_csum_fold (sum0);
340  ip0->length = new_l0;
341 
342  /* Fix UDP length */
343  udp0 = (udp_header_t *) (ip0 + 1);
344  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0)
345  - sizeof (*ip0));
346  udp0->length = new_l0;
347  }
348  else
349  {
350  ip6_header_t *ip0;
351  int bogus0;
352 
353  ip0 = vlib_buffer_get_current (b0);
354 
355  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0)
356  - sizeof (*ip0));
357  ip0->payload_length = new_l0;
358 
359  /* Fix UDP length */
360  udp0 = (udp_header_t *) (ip0 + 1);
361  udp0->length = new_l0;
362 
363  udp0->checksum =
364  ip6_tcp_udp_icmp_compute_checksum (vm, b0, ip0, &bogus0);
365  ASSERT (bogus0 == 0);
366 
367  if (udp0->checksum == 0)
368  udp0->checksum = 0xffff;
369  }
370 }
371 
372 always_inline void
373 ip_udp_encap_one (vlib_main_t * vm, vlib_buffer_t * b0, u8 * ec0, word ec_len,
374  u8 is_ip4)
375 {
376  vlib_buffer_advance (b0, -ec_len);
377 
378  if (is_ip4)
379  {
380  ip4_header_t *ip0;
381 
382  ip0 = vlib_buffer_get_current (b0);
383 
384  /* Apply the encap string. */
385  clib_memcpy_fast (ip0, ec0, ec_len);
386  ip_udp_fixup_one (vm, b0, 1);
387  }
388  else
389  {
390  ip6_header_t *ip0;
391 
392  ip0 = vlib_buffer_get_current (b0);
393 
394  /* Apply the encap string. */
395  clib_memcpy_fast (ip0, ec0, ec_len);
396  ip_udp_fixup_one (vm, b0, 0);
397  }
398 }
399 
400 always_inline void
402  u8 * ec0, u8 * ec1, word ec_len, u8 is_v4)
403 {
404  u16 new_l0, new_l1;
405  udp_header_t *udp0, *udp1;
406 
407  ASSERT (_vec_len (ec0) == _vec_len (ec1));
408 
409  vlib_buffer_advance (b0, -ec_len);
410  vlib_buffer_advance (b1, -ec_len);
411 
412  if (is_v4)
413  {
414  ip4_header_t *ip0, *ip1;
415  ip_csum_t sum0, sum1;
416  u16 old_l0 = 0, old_l1 = 0;
417 
418  ip0 = vlib_buffer_get_current (b0);
419  ip1 = vlib_buffer_get_current (b1);
420 
421  /* Apply the encap string */
422  clib_memcpy_fast (ip0, ec0, ec_len);
423  clib_memcpy_fast (ip1, ec1, ec_len);
424 
425  /* fix the <bleep>ing outer-IP checksum */
426  sum0 = ip0->checksum;
427  sum1 = ip1->checksum;
428 
429  /* old_l0 always 0, see the rewrite setup */
430  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
431  new_l1 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b1));
432 
433  sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
434  length /* changed member */ );
435  sum1 = ip_csum_update (sum1, old_l1, new_l1, ip4_header_t,
436  length /* changed member */ );
437 
438  ip0->checksum = ip_csum_fold (sum0);
439  ip1->checksum = ip_csum_fold (sum1);
440 
441  ip0->length = new_l0;
442  ip1->length = new_l1;
443 
444  /* Fix UDP length */
445  udp0 = (udp_header_t *) (ip0 + 1);
446  udp1 = (udp_header_t *) (ip1 + 1);
447 
448  new_l0 =
449  clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0) -
450  sizeof (*ip0));
451  new_l1 =
452  clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b1) -
453  sizeof (*ip1));
454  udp0->length = new_l0;
455  udp1->length = new_l1;
456  }
457  else
458  {
459  ip6_header_t *ip0, *ip1;
460  int bogus0, bogus1;
461 
462  ip0 = vlib_buffer_get_current (b0);
463  ip1 = vlib_buffer_get_current (b1);
464 
465  /* Apply the encap string. */
466  clib_memcpy_fast (ip0, ec0, ec_len);
467  clib_memcpy_fast (ip1, ec1, ec_len);
468 
469  new_l0 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0)
470  - sizeof (*ip0));
471  new_l1 = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b1)
472  - sizeof (*ip1));
473  ip0->payload_length = new_l0;
474  ip1->payload_length = new_l1;
475 
476  /* Fix UDP length */
477  udp0 = (udp_header_t *) (ip0 + 1);
478  udp1 = (udp_header_t *) (ip1 + 1);
479 
480  udp0->length = new_l0;
481  udp1->length = new_l1;
482 
483  udp0->checksum =
484  ip6_tcp_udp_icmp_compute_checksum (vm, b0, ip0, &bogus0);
485  udp1->checksum =
486  ip6_tcp_udp_icmp_compute_checksum (vm, b1, ip1, &bogus1);
487  ASSERT (bogus0 == 0);
488  ASSERT (bogus1 == 0);
489 
490  if (udp0->checksum == 0)
491  udp0->checksum = 0xffff;
492  if (udp1->checksum == 0)
493  udp1->checksum = 0xffff;
494  }
495 }
496 
497 /*
498  * fd.io coding-style-patch-verification: ON
499  *
500  * Local Variables:
501  * eval: (c-set-style "gnu")
502  * End:
503  */
504 
505 #endif /* __included_udp_h__ */
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
static udp_connection_t * udp_connection_from_transport(transport_connection_t *tc)
Definition: udp.h:206
static udp_connection_t * udp_listener_get(u32 conn_index)
Definition: udp.h:194
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:60
unformat_function_t unformat_udp_header
Definition: udp.h:284
vl_api_wireguard_peer_flags_t flags
Definition: wireguard.api:103
u32 * connection_peekers
Definition: udp.h:171
vl_api_ip_port_and_mask_t dst_port
Definition: flow_types.api:92
uword * dst_port_info_by_dst_port[N_UDP_AF]
Definition: udp.h:155
unformat_function_t unformat_udp_port
Definition: udp.h:285
#define clib_memcpy_fast(a, b, c)
Definition: string.h:81
static_always_inline void clib_spinlock_unlock_if_init(clib_spinlock_t *p)
Definition: lock.h:127
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:113
uword unformat_pg_edit(unformat_input_t *input, va_list *args)
Definition: edit.c:106
static udp_dst_port_info_t * udp_get_dst_port_info(udp_main_t *um, udp_dst_port_t dst_port, u8 is_ip4)
Definition: udp.h:275
uword ip_csum_t
Definition: ip_packet.h:244
vlib_node_registration_t udp4_local_node
(constructor) VLIB_REGISTER_NODE (udp4_local_node)
Definition: udp_local.c:403
static void * vlib_buffer_push_udp(vlib_buffer_t *b, u16 sp, u16 dp, u8 offload_csum)
Definition: udp.h:300
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:402
udp_conn_flags_
Definition: udp.h:53
unsigned char u8
Definition: types.h:56
static udp_main_t * vnet_get_udp_main()
Definition: udp.h:200
u8 flags
connection flags
Definition: udp.h:66
u8 *() format_function_t(u8 *s, va_list *args)
Definition: format.h:48
i64 word
Definition: types.h:111
udp_connection_t * udp_connection_alloc(u32 thread_index)
Definition: udp.c:92
#define vec_elt_at_index(v, i)
Get vector value at index i checking that i is in bounds.
void udp_add_dst_port(udp_main_t *um, udp_dst_port_t dst_port, char *dst_port_name, u8 is_ip4)
Definition: udp_local.c:448
#define foreach_udp6_dst_port
Definition: udp.h:91
void udp_connection_share_port(u16 lcl_port, u8 is_ip4)
Definition: udp.c:80
unsigned int u32
Definition: types.h:88
static ct_connection_t * connections
static void udp_pool_remove_peeker(u32 thread_index)
Definition: udp.h:237
vlib_node_registration_t udp4_input_node
(constructor) VLIB_REGISTER_NODE (udp4_input_node)
Definition: udp_input.c:345
#define hash_get(h, key)
Definition: hash.h:249
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:534
udp_main_t udp_main
Definition: udp.c:22
static u32 udp_connection_index(udp_connection_t *uc)
Definition: udp.h:212
format_function_t format_udp_connection
Definition: udp.h:283
udp_dst_port_info_t * dst_port_infos[N_UDP_AF]
Definition: udp.h:151
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
clib_spinlock_t * peekers_readers_locks
Definition: udp.h:172
vlib_node_registration_t udp6_input_node
(constructor) VLIB_REGISTER_NODE (udp6_input_node)
Definition: udp_input.c:371
#define PREDICT_FALSE(x)
Definition: clib.h:120
#define always_inline
Definition: ipsec.h:28
udp_connection_t * listener_pool
Definition: udp.h:174
static void ip_udp_encap_one(vlib_main_t *vm, vlib_buffer_t *b0, u8 *ec0, word ec_len, u8 is_ip4)
Definition: udp.h:374
uword() unformat_function_t(unformat_input_t *input, va_list *args)
Definition: format.h:233
Definition: udp.h:144
static void udp_pool_add_peeker(u32 thread_index)
Acquires a lock that blocks a connection pool from expanding.
Definition: udp.h:224
void udp_punt_unknown(vlib_main_t *vm, u8 is_ip4, u8 is_add)
Definition: udp_local.c:545
static void ip_udp_fixup_one(vlib_main_t *vm, vlib_buffer_t *b0, u8 is_ip4)
Definition: udp.h:320
format_function_t format_udp_rx_trace
Definition: udp.h:282
static void ip_udp_encap_two(vlib_main_t *vm, vlib_buffer_t *b0, vlib_buffer_t *b1, u8 *ec0, u8 *ec1, word ec_len, u8 is_v4)
Definition: udp.h:402
static_always_inline uword vlib_get_thread_index(void)
Definition: threads.h:219
void udp_unregister_dst_port(vlib_main_t *vm, udp_dst_port_t dst_port, u8 is_ip4)
Definition: udp_local.c:506
u8 data[]
Packet data.
Definition: buffer.h:181
static udp_connection_t * udp_connection_get(u32 conn_index, u32 thread_index)
Definition: udp.h:186
struct _transport_connection transport_connection_t
udp_error_t
Definition: udp.h:29
#define pool_is_free_index(P, I)
Use free bitmap to query whether given index is free.
Definition: pool.h:299
string name[64]
Definition: ip.api:44
udp_dst_port_t
Definition: udp.h:107
u16 ip6_tcp_udp_icmp_compute_checksum(vlib_main_t *vm, vlib_buffer_t *p0, ip6_header_t *ip0, int *bogus_lengthp)
Definition: ip6_forward.c:1095
#define foreach_udp4_dst_port
Definition: udp.h:70
#define ASSERT(truth)
udp_af_t
Definition: udp.h:142
static void vlib_buffer_advance(vlib_buffer_t *b, word l)
Advance current data pointer by the supplied (signed!) amount.
Definition: buffer.h:248
clib_spinlock_t * peekers_write_locks
Definition: udp.h:173
#define foreach_udp_connection_flag
cloned to another thread
Definition: udp.h:37
enum udp_conn_flags_ udp_conn_flags_t
struct _vlib_node_registration vlib_node_registration_t
static void * vlib_buffer_push_uninit(vlib_buffer_t *b, u8 size)
Prepend uninitialized data to buffer.
Definition: buffer.h:335
u16 payload_length
Definition: ip6_packet.h:301
bool udp_is_valid_dst_port(udp_dst_port_t dst_port, u8 is_ip4)
Definition: udp_local.c:529
VLIB buffer representation.
Definition: buffer.h:102
u64 uword
Definition: types.h:112
#define ip_csum_update(sum, old, new, type, field)
Definition: ip_packet.h:294
udp_conn_flags_bits
Definition: udp.h:45
vlib_node_registration_t udp6_local_node
(constructor) VLIB_REGISTER_NODE (udp6_local_node)
Definition: udp_local.c:425
#define vnet_buffer(b)
Definition: buffer.h:417
void udp_connection_free(udp_connection_t *uc)
Definition: udp.c:123
void udp_register_dst_port(vlib_main_t *vm, udp_dst_port_t dst_port, u32 node_index, u8 is_ip4)
Definition: udp_local.c:468
static udp_connection_t * udp_connection_clone_safe(u32 connection_index, u32 thread_index)
Definition: udp.h:252
u32 total_length_not_including_first_buffer
Only valid for first buffer in chain.
Definition: buffer.h:167
udp_connection_t ** connections
Definition: udp.h:170
static_always_inline void clib_spinlock_lock_if_init(clib_spinlock_t *p)
Definition: lock.h:104
udp6_dst_port_t
Definition: udp.h:114
Definition: udp.h:145
static u16 ip_csum_fold(ip_csum_t c)
Definition: ip_packet.h:300
Definition: udp.h:146
format_function_t format_udp_header
Definition: udp.h:281