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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
16 * ip4/packet.h: ip4 packet format
18 * Copyright (c) 2008 Eliot Dresselhaus
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:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
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.
40 #ifndef included_ip4_packet_h
41 #define included_ip4_packet_h
43 #include <vnet/ip/ip_packet.h> /* for ip_csum_t */
44 #include <vnet/tcp/tcp_packet.h> /* for tcp_header_t */
45 #include <vppinfra/byte_order.h> /* for clib_net_to_host_u16 */
47 /* IP4 address which can be accessed either as 4 bytes
48 or as a 32-bit number. */
61 /* IP address must be first for ip_interface_address_get_address() to work */
62 ip4_address_t ip4_addr;
67 ip4_addr_fib_init (ip4_address_fib_t * addr_fib,
68 const ip4_address_t * address, u32 fib_index)
70 clib_memcpy_fast (&addr_fib->ip4_addr, address,
71 sizeof (addr_fib->ip4_addr));
72 addr_fib->fib_index = fib_index;
75 /* (src,dst) pair of addresses as found in packet header. */
78 ip4_address_t src, dst;
83 ip4_address_t addr, mask;
84 } ip4_address_and_mask_t;
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;
94 /* Type of service. */
97 /* Total layer 3 packet length including this header. */
100 /* Fragmentation ID. */
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)
110 /* Time to live decremented by router at each hop. */
113 /* Next level protocol packet. */
119 /* Source and destination address. */
124 ip4_address_t src_address, dst_address;
126 ip4_address_pair_t address_pair;
130 /* For checksumming we'll want to access IP header in word sized chunks. */
131 /* For 64 bit machines. */
133 CLIB_PACKED (struct {
134 u64 checksum_data_64[2];
135 u32 checksum_data_64_32[1];
139 /* For 32 bit machines. */
141 CLIB_PACKED (struct {
142 u32 checksum_data_32[5];
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)))
151 #define IP4_ROUTER_ALERT_OPTION 20
154 ip4_get_fragment_offset (const ip4_header_t * i)
156 return clib_net_to_host_u16 (i->flags_and_fragment_offset) & 0x1fff;
160 ip4_get_fragment_more (const ip4_header_t * i)
162 return clib_net_to_host_u16 (i->flags_and_fragment_offset) &
163 IP4_HEADER_FLAG_MORE_FRAGMENTS;
167 ip4_is_fragment (const ip4_header_t * i)
169 return (i->flags_and_fragment_offset &
170 clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS));
174 ip4_is_first_fragment (const ip4_header_t * i)
176 return (i->flags_and_fragment_offset &
177 clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS)) ==
178 clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
181 /* Fragment offset in bytes. */
183 ip4_get_fragment_offset_bytes (const ip4_header_t * i)
185 return 8 * ip4_get_fragment_offset (i);
189 ip4_header_bytes (const ip4_header_t * i)
191 return sizeof (u32) * (i->ip_version_and_header_length & 0xf);
195 ip4_next_header (ip4_header_t * i)
197 return (void *) i + ip4_header_bytes (i);
201 ip4_header_checksum (ip4_header_t * i)
203 u16 *iphdr = (u16 *) i;
205 int option_len = (i->ip_version_and_header_length & 0xf) - 5;
207 sum += clib_net_to_host_u16 (iphdr[0]);
208 sum += clib_net_to_host_u16 (iphdr[1]);
209 sum += clib_net_to_host_u16 (iphdr[2]);
210 sum += clib_net_to_host_u16 (iphdr[3]);
211 sum += clib_net_to_host_u16 (iphdr[4]);
213 sum += clib_net_to_host_u16 (iphdr[6]);
214 sum += clib_net_to_host_u16 (iphdr[7]);
215 sum += clib_net_to_host_u16 (iphdr[8]);
216 sum += clib_net_to_host_u16 (iphdr[9]);
218 if (PREDICT_FALSE (option_len > 0))
222 sum += clib_net_to_host_u16 (iphdr[28]);
223 sum += clib_net_to_host_u16 (iphdr[29]);
225 sum += clib_net_to_host_u16 (iphdr[26]);
226 sum += clib_net_to_host_u16 (iphdr[27]);
228 sum += clib_net_to_host_u16 (iphdr[24]);
229 sum += clib_net_to_host_u16 (iphdr[25]);
231 sum += clib_net_to_host_u16 (iphdr[22]);
232 sum += clib_net_to_host_u16 (iphdr[23]);
234 sum += clib_net_to_host_u16 (iphdr[20]);
235 sum += clib_net_to_host_u16 (iphdr[21]);
237 sum += clib_net_to_host_u16 (iphdr[18]);
238 sum += clib_net_to_host_u16 (iphdr[19]);
240 sum += clib_net_to_host_u16 (iphdr[16]);
241 sum += clib_net_to_host_u16 (iphdr[17]);
243 sum += clib_net_to_host_u16 (iphdr[14]);
244 sum += clib_net_to_host_u16 (iphdr[15]);
246 sum += clib_net_to_host_u16 (iphdr[12]);
247 sum += clib_net_to_host_u16 (iphdr[13]);
249 sum += clib_net_to_host_u16 (iphdr[10]);
250 sum += clib_net_to_host_u16 (iphdr[11]);
255 sum = ((u16) sum) + (sum >> 16);
256 sum = ((u16) sum) + (sum >> 16);
257 return clib_host_to_net_u16 (~((u16) sum));
261 ip4_header_set_dscp (ip4_header_t * ip4, ip_dscp_t dscp)
264 /* not masking the dscp value to save th instruction
265 * it shouldn't b necessary since the argument is an enum
266 * whose range is therefore constrained in the CP. in the
267 * DP it will have been taken from another packet, so again
268 * constrained in value */
269 ip4->tos |= dscp << IP_PACKET_TC_FIELD_DSCP_BIT_SHIFT;
273 ip4_header_set_ecn (ip4_header_t * ip4, ip_ecn_t ecn)
275 ip4->tos &= ~IP_PACKET_TC_FIELD_ECN_MASK;
280 ip4_header_set_ecn_w_chksum (ip4_header_t * ip4, ip_ecn_t ecn)
282 ip_csum_t sum = ip4->checksum;
284 u8 new = (old & ~IP_PACKET_TC_FIELD_ECN_MASK) | ecn;
286 sum = ip_csum_update (sum, old, new, ip4_header_t, tos);
287 ip4->checksum = ip_csum_fold (sum);
291 always_inline ip_dscp_t
292 ip4_header_get_dscp (const ip4_header_t * ip4)
294 return (ip4->tos >> IP_PACKET_TC_FIELD_DSCP_BIT_SHIFT);
297 always_inline ip_ecn_t
298 ip4_header_get_ecn (const ip4_header_t * ip4)
300 return (ip4->tos & IP_PACKET_TC_FIELD_ECN_MASK);
304 ip4_header_set_df (ip4_header_t * ip4)
306 ip4->flags_and_fragment_offset |=
307 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT);
311 ip4_header_clear_df (ip4_header_t * ip4)
313 ip4->flags_and_fragment_offset &=
314 ~clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT);
318 ip4_header_get_df (const ip4_header_t * ip4)
320 return (! !(ip4->flags_and_fragment_offset &
321 clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT)));
325 ip4_header_checksum_is_valid (ip4_header_t * i)
327 return i->checksum == ip4_header_checksum (i);
330 #define ip4_partial_header_checksum_x1(ip0,sum0) \
332 if (BITS (ip_csum_t) > 32) \
334 sum0 = ip0->checksum_data_64[0]; \
335 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
336 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
340 sum0 = ip0->checksum_data_32[0]; \
341 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
342 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
343 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
344 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
348 #define ip4_partial_header_checksum_x2(ip0,ip1,sum0,sum1) \
350 if (BITS (ip_csum_t) > 32) \
352 sum0 = ip0->checksum_data_64[0]; \
353 sum1 = ip1->checksum_data_64[0]; \
354 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
355 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64[1]); \
356 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
357 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64_32[0]); \
361 sum0 = ip0->checksum_data_32[0]; \
362 sum1 = ip1->checksum_data_32[0]; \
363 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
364 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[1]); \
365 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
366 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[2]); \
367 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
368 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[3]); \
369 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
370 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[4]); \
375 ip4_address_is_multicast (const ip4_address_t * a)
377 return (a->data[0] & 0xf0) == 0xe0;
381 ip4_address_is_global_broadcast (const ip4_address_t * a)
383 return (a->as_u32) == 0xffffffff;
387 ip4_multicast_address_set_for_group (ip4_address_t * a,
388 ip_multicast_group_t g)
390 ASSERT ((u32) g < (1 << 28));
391 a->as_u32 = clib_host_to_net_u32 ((0xe << 28) + g);
395 ip4_multicast_ethernet_address (u8 * ethernet_address,
396 const ip4_address_t * a)
398 const u8 *d = a->as_u8;
400 ethernet_address[0] = 0x01;
401 ethernet_address[1] = 0x00;
402 ethernet_address[2] = 0x5e;
403 ethernet_address[3] = d[1] & 0x7f;
404 ethernet_address[4] = d[2];
405 ethernet_address[5] = d[3];
409 ip4_tcp_reply_x1 (ip4_header_t * ip0, tcp_header_t * tcp0)
413 src0 = ip0->src_address.data_u32;
414 dst0 = ip0->dst_address.data_u32;
415 ip0->src_address.data_u32 = dst0;
416 ip0->dst_address.data_u32 = src0;
425 ip4_tcp_reply_x2 (ip4_header_t * ip0, ip4_header_t * ip1,
426 tcp_header_t * tcp0, tcp_header_t * tcp1)
428 u32 src0, dst0, src1, dst1;
430 src0 = ip0->src_address.data_u32;
431 src1 = ip1->src_address.data_u32;
432 dst0 = ip0->dst_address.data_u32;
433 dst1 = ip1->dst_address.data_u32;
434 ip0->src_address.data_u32 = dst0;
435 ip1->src_address.data_u32 = dst1;
436 ip0->dst_address.data_u32 = src0;
437 ip1->dst_address.data_u32 = src1;
449 #endif /* included_ip4_packet_h */
452 * fd.io coding-style-patch-verification: ON
455 * eval: (c-set-style "gnu")