Line data Source code
1 : /*
2 : * Copyright (c) 2015 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 : * ip4/packet.h: ip4 packet format
17 : *
18 : * Copyright (c) 2008 Eliot Dresselhaus
19 : *
20 : * Permission is hereby granted, free of charge, to any person obtaining
21 : * a copy of this software and associated documentation files (the
22 : * "Software"), to deal in the Software without restriction, including
23 : * without limitation the rights to use, copy, modify, merge, publish,
24 : * distribute, sublicense, and/or sell copies of the Software, and to
25 : * permit persons to whom the Software is furnished to do so, subject to
26 : * the following conditions:
27 : *
28 : * The above copyright notice and this permission notice shall be
29 : * included in all copies or substantial portions of the Software.
30 : *
31 : * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 : * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 : * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 : * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 : * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 : * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 : * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
38 : */
39 :
40 : #ifndef included_ip4_packet_h
41 : #define included_ip4_packet_h
42 :
43 : #include <vnet/ip/ip_packet.h> /* for ip_csum_t */
44 : #include <vppinfra/byte_order.h> /* for clib_net_to_host_u16 */
45 : #include <vppinfra/warnings.h> /* for WARN_OFF/WARN_ON macro */
46 :
47 : /* IP4 address which can be accessed either as 4 bytes
48 : or as a 32-bit number. */
49 : typedef union
50 : {
51 : u8 data[4];
52 : u32 data_u32;
53 : /* Aliases. */
54 : u8 as_u8[4];
55 : u16 as_u16[2];
56 : u32 as_u32;
57 : } ip4_address_t;
58 :
59 : typedef struct
60 : {
61 : /* IP address must be first for ip_interface_address_get_address() to work */
62 : ip4_address_t ip4_addr;
63 : u32 fib_index;
64 : } ip4_address_fib_t;
65 :
66 : always_inline void
67 4845 : ip4_addr_fib_init (ip4_address_fib_t * addr_fib,
68 : const ip4_address_t * address, u32 fib_index)
69 : {
70 4845 : clib_memcpy_fast (&addr_fib->ip4_addr, address,
71 : sizeof (addr_fib->ip4_addr));
72 4845 : addr_fib->fib_index = fib_index;
73 4845 : }
74 :
75 : /* (src,dst) pair of addresses as found in packet header. */
76 : typedef struct
77 : {
78 : ip4_address_t src, dst;
79 : } ip4_address_pair_t;
80 :
81 : typedef struct
82 : {
83 : ip4_address_t addr, mask;
84 : } ip4_address_and_mask_t;
85 :
86 : typedef union
87 : {
88 : struct
89 : {
90 : /* 4 bit packet length (in 32bit units) and version VVVVLLLL.
91 : e.g. for packets w/ no options ip_version_and_header_length == 0x45. */
92 : u8 ip_version_and_header_length;
93 :
94 : /* Type of service. */
95 : ip_dscp_t tos;
96 :
97 : /* Total layer 3 packet length including this header. */
98 : u16 length;
99 :
100 : /* Fragmentation ID. */
101 : u16 fragment_id;
102 :
103 : /* 3 bits of flags and 13 bits of fragment offset (in units
104 : of 8 byte quantities). */
105 : u16 flags_and_fragment_offset;
106 : #define IP4_HEADER_FLAG_MORE_FRAGMENTS (1 << 13)
107 : #define IP4_HEADER_FLAG_DONT_FRAGMENT (1 << 14)
108 : #define IP4_HEADER_FLAG_CONGESTION (1 << 15)
109 :
110 : /* Time to live decremented by router at each hop. */
111 : u8 ttl;
112 :
113 : /* Next level protocol packet. */
114 : u8 protocol;
115 :
116 : /* Checksum. */
117 : u16 checksum;
118 :
119 : /* Source and destination address. */
120 : union
121 : {
122 : struct
123 : {
124 : ip4_address_t src_address, dst_address;
125 : };
126 : ip4_address_pair_t address_pair;
127 : };
128 : };
129 :
130 : /* For checksumming we'll want to access IP header in word sized chunks. */
131 : /* For 64 bit machines. */
132 : /* *INDENT-OFF* */
133 : CLIB_PACKED (struct {
134 : u64 checksum_data_64[2];
135 : u32 checksum_data_64_32[1];
136 : });
137 : /* *INDENT-ON* */
138 :
139 : /* For 32 bit machines. */
140 : /* *INDENT-OFF* */
141 : CLIB_PACKED (struct {
142 : u32 checksum_data_32[5];
143 : });
144 : /* *INDENT-ON* */
145 : } ip4_header_t;
146 :
147 : /* Value of ip_version_and_header_length for packets w/o options. */
148 : #define IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS \
149 : ((4 << 4) | (sizeof (ip4_header_t) / sizeof (u32)))
150 :
151 : #define IP4_ROUTER_ALERT_OPTION 20
152 :
153 : always_inline u16
154 13742211 : ip4_get_fragment_offset (const ip4_header_t * i)
155 : {
156 13742211 : return clib_net_to_host_u16 (i->flags_and_fragment_offset) & 0x1fff;
157 : }
158 :
159 : always_inline u16
160 74800 : ip4_get_fragment_more (const ip4_header_t * i)
161 : {
162 74800 : return clib_net_to_host_u16 (i->flags_and_fragment_offset) &
163 : IP4_HEADER_FLAG_MORE_FRAGMENTS;
164 : }
165 :
166 : always_inline int
167 1296327 : ip4_is_fragment (const ip4_header_t * i)
168 : {
169 1296327 : return (i->flags_and_fragment_offset &
170 1296327 : clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS));
171 : }
172 :
173 : always_inline int
174 0 : ip4_is_first_fragment (const ip4_header_t * i)
175 : {
176 0 : return (i->flags_and_fragment_offset &
177 0 : clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS)) ==
178 0 : clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
179 : }
180 :
181 : /* Fragment offset in bytes. */
182 : always_inline int
183 45052 : ip4_get_fragment_offset_bytes (const ip4_header_t * i)
184 : {
185 45052 : return 8 * ip4_get_fragment_offset (i);
186 : }
187 :
188 : always_inline int
189 51728716 : ip4_header_bytes (const ip4_header_t * i)
190 : {
191 51728716 : return sizeof (u32) * (i->ip_version_and_header_length & 0xf);
192 : }
193 :
194 : always_inline void *
195 1454798 : ip4_next_header (ip4_header_t * i)
196 : {
197 1454798 : return (void *) i + ip4_header_bytes (i);
198 : }
199 :
200 : /* Turn off array bounds check due to ip4_header_t
201 : option field operations. */
202 :
203 : /* *INDENT-OFF* */
204 : WARN_OFF(array-bounds)
205 : /* *INDENT-ON* */
206 :
207 : static_always_inline u16
208 18495201 : ip4_header_checksum_inline (ip4_header_t * i, int with_checksum)
209 : {
210 18495201 : int option_len = (i->ip_version_and_header_length & 0xf) - 5;
211 18495201 : uword sum = 0;
212 : #if uword_bits == 64
213 18495201 : u32 *iphdr = (u32 *) i;
214 :
215 18495201 : sum += iphdr[0];
216 18495201 : sum += iphdr[1];
217 18495201 : sum += with_checksum ? iphdr[2] : *(u16 *) (iphdr + 2);
218 : /* skip checksum */
219 18495201 : sum += iphdr[3];
220 18495201 : sum += iphdr[4];
221 :
222 18495201 : if (PREDICT_FALSE (option_len > 0))
223 82 : switch (option_len)
224 : {
225 0 : case 10:
226 0 : sum += iphdr[14];
227 0 : case 9:
228 0 : sum += iphdr[13];
229 0 : case 8:
230 0 : sum += iphdr[12];
231 0 : case 7:
232 0 : sum += iphdr[11];
233 0 : case 6:
234 0 : sum += iphdr[10];
235 0 : case 5:
236 0 : sum += iphdr[9];
237 0 : case 4:
238 0 : sum += iphdr[8];
239 0 : case 3:
240 0 : sum += iphdr[7];
241 0 : case 2:
242 0 : sum += iphdr[6];
243 82 : case 1:
244 82 : sum += iphdr[5];
245 82 : default:
246 82 : break;
247 : }
248 :
249 18495122 : sum = ((u32) sum) + (sum >> 32);
250 : #else
251 : u16 *iphdr = (u16 *) i;
252 :
253 : sum += iphdr[0];
254 : sum += iphdr[1];
255 : sum += iphdr[2];
256 : sum += iphdr[3];
257 : sum += iphdr[4];
258 : if (with_checksum)
259 : sum += iphdr[5];
260 : sum += iphdr[6];
261 : sum += iphdr[7];
262 : sum += iphdr[8];
263 : sum += iphdr[9];
264 :
265 : if (PREDICT_FALSE (option_len > 0))
266 : switch (option_len)
267 : {
268 : case 10:
269 : sum += iphdr[28];
270 : sum += iphdr[29];
271 : case 9:
272 : sum += iphdr[26];
273 : sum += iphdr[27];
274 : case 8:
275 : sum += iphdr[24];
276 : sum += iphdr[25];
277 : case 7:
278 : sum += iphdr[22];
279 : sum += iphdr[23];
280 : case 6:
281 : sum += iphdr[20];
282 : sum += iphdr[21];
283 : case 5:
284 : sum += iphdr[18];
285 : sum += iphdr[19];
286 : case 4:
287 : sum += iphdr[16];
288 : sum += iphdr[17];
289 : case 3:
290 : sum += iphdr[14];
291 : sum += iphdr[15];
292 : case 2:
293 : sum += iphdr[12];
294 : sum += iphdr[13];
295 : case 1:
296 : sum += iphdr[10];
297 : sum += iphdr[11];
298 : default:
299 : break;
300 : }
301 : #endif
302 :
303 18495201 : sum = ((u16) sum) + (sum >> 16);
304 18495201 : sum = ((u16) sum) + (sum >> 16);
305 18495201 : return ~((u16) sum);
306 : }
307 :
308 : /* *INDENT-OFF* */
309 : WARN_ON(array-bounds)
310 : /* *INDENT-ON* */
311 :
312 : always_inline u16
313 3716387 : ip4_header_checksum (ip4_header_t * i)
314 : {
315 3716387 : return ip4_header_checksum_inline (i, /* with_checksum */ 0);
316 : }
317 :
318 : always_inline void
319 1123112 : ip4_header_set_dscp (ip4_header_t * ip4, ip_dscp_t dscp)
320 : {
321 1123112 : ip4->tos &= ~0xfc;
322 : /* not masking the dscp value to save th instruction
323 : * it shouldn't b necessary since the argument is an enum
324 : * whose range is therefore constrained in the CP. in the
325 : * DP it will have been taken from another packet, so again
326 : * constrained in value */
327 1123112 : ip4->tos |= dscp << IP_PACKET_TC_FIELD_DSCP_BIT_SHIFT;
328 1123112 : }
329 :
330 : always_inline void
331 1122836 : ip4_header_set_ecn (ip4_header_t * ip4, ip_ecn_t ecn)
332 : {
333 1122836 : ip4->tos &= ~IP_PACKET_TC_FIELD_ECN_MASK;
334 1122836 : ip4->tos |= ecn;
335 1122836 : }
336 :
337 : always_inline void
338 504 : ip4_header_set_ecn_w_chksum (ip4_header_t * ip4, ip_ecn_t ecn)
339 : {
340 504 : ip_csum_t sum = ip4->checksum;
341 504 : u8 old = ip4->tos;
342 504 : u8 new = (old & ~IP_PACKET_TC_FIELD_ECN_MASK) | ecn;
343 :
344 504 : sum = ip_csum_update (sum, old, new, ip4_header_t, tos);
345 504 : ip4->checksum = ip_csum_fold (sum);
346 504 : ip4->tos = new;
347 504 : }
348 :
349 : always_inline ip_dscp_t
350 1398425 : ip4_header_get_dscp (const ip4_header_t * ip4)
351 : {
352 1398425 : return (ip4->tos >> IP_PACKET_TC_FIELD_DSCP_BIT_SHIFT);
353 : }
354 :
355 : always_inline ip_ecn_t
356 1398769 : ip4_header_get_ecn (const ip4_header_t * ip4)
357 : {
358 1398769 : return (ip4->tos & IP_PACKET_TC_FIELD_ECN_MASK);
359 : }
360 :
361 : always_inline u8
362 127 : ip4_header_get_ttl (const ip4_header_t *ip4)
363 : {
364 127 : return (ip4->ttl);
365 : }
366 :
367 : always_inline void
368 0 : ip4_header_set_ttl (ip4_header_t *ip4, u8 ttl)
369 : {
370 0 : ip4->ttl = ttl;
371 0 : }
372 :
373 : always_inline void
374 65 : ip4_header_set_df (ip4_header_t * ip4)
375 : {
376 65 : ip4->flags_and_fragment_offset |=
377 65 : clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT);
378 65 : }
379 :
380 : always_inline void
381 : ip4_header_clear_df (ip4_header_t * ip4)
382 : {
383 : ip4->flags_and_fragment_offset &=
384 : ~clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT);
385 : }
386 :
387 : always_inline u8
388 252 : ip4_header_get_df (const ip4_header_t * ip4)
389 : {
390 252 : return (! !(ip4->flags_and_fragment_offset &
391 252 : clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT)));
392 : }
393 :
394 : static inline uword
395 14778751 : ip4_header_checksum_is_valid (ip4_header_t * i)
396 : {
397 14778751 : return ip4_header_checksum_inline (i, /* with_checksum */ 1) == 0;
398 : }
399 :
400 : #define ip4_partial_header_checksum_x1(ip0,sum0) \
401 : do { \
402 : if (BITS (ip_csum_t) > 32) \
403 : { \
404 : sum0 = ip0->checksum_data_64[0]; \
405 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
406 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
407 : } \
408 : else \
409 : { \
410 : sum0 = ip0->checksum_data_32[0]; \
411 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
412 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
413 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
414 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
415 : } \
416 : } while (0)
417 :
418 : #define ip4_partial_header_checksum_x2(ip0,ip1,sum0,sum1) \
419 : do { \
420 : if (BITS (ip_csum_t) > 32) \
421 : { \
422 : sum0 = ip0->checksum_data_64[0]; \
423 : sum1 = ip1->checksum_data_64[0]; \
424 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
425 : sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64[1]); \
426 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
427 : sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64_32[0]); \
428 : } \
429 : else \
430 : { \
431 : sum0 = ip0->checksum_data_32[0]; \
432 : sum1 = ip1->checksum_data_32[0]; \
433 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
434 : sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[1]); \
435 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
436 : sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[2]); \
437 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
438 : sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[3]); \
439 : sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
440 : sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[4]); \
441 : } \
442 : } while (0)
443 :
444 : always_inline uword
445 13573989 : ip4_address_is_multicast (const ip4_address_t * a)
446 : {
447 13573989 : return (a->data[0] & 0xf0) == 0xe0;
448 : }
449 :
450 : always_inline uword
451 819 : ip4_address_is_global_broadcast (const ip4_address_t * a)
452 : {
453 819 : return (a->as_u32) == 0xffffffff;
454 : }
455 :
456 : always_inline void
457 : ip4_multicast_address_set_for_group (ip4_address_t * a,
458 : ip_multicast_group_t g)
459 : {
460 : ASSERT ((u32) g < (1 << 28));
461 : a->as_u32 = clib_host_to_net_u32 ((0xe << 28) + g);
462 : }
463 :
464 : always_inline void
465 : ip4_multicast_ethernet_address (u8 * ethernet_address,
466 : const ip4_address_t * a)
467 : {
468 : const u8 *d = a->as_u8;
469 :
470 : ethernet_address[0] = 0x01;
471 : ethernet_address[1] = 0x00;
472 : ethernet_address[2] = 0x5e;
473 : ethernet_address[3] = d[1] & 0x7f;
474 : ethernet_address[4] = d[2];
475 : ethernet_address[5] = d[3];
476 : }
477 :
478 : #endif /* included_ip4_packet_h */
479 :
480 : /*
481 : * fd.io coding-style-patch-verification: ON
482 : *
483 : * Local Variables:
484 : * eval: (c-set-style "gnu")
485 : * End:
486 : */
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