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,
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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, ip4_address_t * address,
70 clib_memcpy (&addr_fib->ip4_addr, address, sizeof (addr_fib->ip4_addr));
71 addr_fib->fib_index = fib_index;
74 /* (src,dst) pair of addresses as found in packet header. */
77 ip4_address_t src, dst;
82 ip4_address_t addr, mask;
83 } ip4_address_and_mask_t;
85 /* If address is a valid netmask, return length of mask. */
87 ip4_address_netmask_length (ip4_address_t * a)
91 for (i = 0; i < ARRAY_LEN (a->as_u8); i++)
123 /* Not a valid netmask mask. */
135 /* 4 bit packet length (in 32bit units) and version VVVVLLLL.
136 e.g. for packets w/ no options ip_version_and_header_length == 0x45. */
137 u8 ip_version_and_header_length;
139 /* Type of service. */
142 /* Total layer 3 packet length including this header. */
145 /* Fragmentation ID. */
148 /* 3 bits of flags and 13 bits of fragment offset (in units
149 of 8 byte quantities). */
150 u16 flags_and_fragment_offset;
151 #define IP4_HEADER_FLAG_MORE_FRAGMENTS (1 << 13)
152 #define IP4_HEADER_FLAG_DONT_FRAGMENT (1 << 14)
153 #define IP4_HEADER_FLAG_CONGESTION (1 << 15)
155 /* Time to live decremented by router at each hop. */
158 /* Next level protocol packet. */
164 /* Source and destination address. */
169 ip4_address_t src_address, dst_address;
171 ip4_address_pair_t address_pair;
175 /* For checksumming we'll want to access IP header in word sized chunks. */
176 /* For 64 bit machines. */
178 CLIB_PACKED (struct {
179 u64 checksum_data_64[2];
180 u32 checksum_data_64_32[1];
184 /* For 32 bit machines. */
186 CLIB_PACKED (struct {
187 u32 checksum_data_32[5];
192 /* Value of ip_version_and_header_length for packets w/o options. */
193 #define IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS \
194 ((4 << 4) | (sizeof (ip4_header_t) / sizeof (u32)))
197 ip4_get_fragment_offset (ip4_header_t * i)
199 return clib_net_to_host_u16 (i->flags_and_fragment_offset) & 0x1fff;
203 ip4_get_fragment_more (ip4_header_t * i)
205 return clib_net_to_host_u16 (i->flags_and_fragment_offset) &
206 IP4_HEADER_FLAG_MORE_FRAGMENTS;
210 ip4_is_fragment (ip4_header_t * i)
212 return (i->flags_and_fragment_offset &
213 clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS));
217 ip4_is_first_fragment (ip4_header_t * i)
219 return (i->flags_and_fragment_offset &
220 clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS)) ==
221 clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
224 /* Fragment offset in bytes. */
226 ip4_get_fragment_offset_bytes (ip4_header_t * i)
228 return 8 * ip4_get_fragment_offset (i);
232 ip4_header_bytes (ip4_header_t * i)
234 return sizeof (u32) * (i->ip_version_and_header_length & 0xf);
238 ip4_next_header (ip4_header_t * i)
240 return (void *) i + ip4_header_bytes (i);
244 ip4_header_checksum (ip4_header_t * i)
251 sum = ip_incremental_checksum (0, i, ip4_header_bytes (i));
252 csum = ~ip_csum_fold (sum);
256 /* Make checksum agree for special case where either
257 0 or 0xffff would give same 1s complement sum. */
258 if (csum == 0 && save == 0xffff)
265 ip4_header_checksum_is_valid (ip4_header_t * i)
267 return i->checksum == ip4_header_checksum (i);
270 #define ip4_partial_header_checksum_x1(ip0,sum0) \
272 if (BITS (ip_csum_t) > 32) \
274 sum0 = ip0->checksum_data_64[0]; \
275 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
276 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
280 sum0 = ip0->checksum_data_32[0]; \
281 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
282 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
283 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
284 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
288 #define ip4_partial_header_checksum_x2(ip0,ip1,sum0,sum1) \
290 if (BITS (ip_csum_t) > 32) \
292 sum0 = ip0->checksum_data_64[0]; \
293 sum1 = ip1->checksum_data_64[0]; \
294 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
295 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64[1]); \
296 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
297 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64_32[0]); \
301 sum0 = ip0->checksum_data_32[0]; \
302 sum1 = ip1->checksum_data_32[0]; \
303 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
304 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[1]); \
305 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
306 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[2]); \
307 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
308 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[3]); \
309 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
310 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[4]); \
315 ip4_address_is_multicast (ip4_address_t * a)
317 return (a->data[0] & 0xf0) == 0xe0;
321 ip4_multicast_address_set_for_group (ip4_address_t * a,
322 ip_multicast_group_t g)
324 ASSERT ((u32) g < (1 << 28));
325 a->as_u32 = clib_host_to_net_u32 ((0xe << 28) + g);
329 ip4_multicast_ethernet_address (u8 * ethernet_address, ip4_address_t * a)
333 ethernet_address[0] = 0x01;
334 ethernet_address[1] = 0x00;
335 ethernet_address[2] = 0x5e;
336 ethernet_address[3] = d[1] & 0x7f;
337 ethernet_address[4] = d[2];
338 ethernet_address[5] = d[3];
342 ip4_tcp_reply_x1 (ip4_header_t * ip0, tcp_header_t * tcp0)
346 src0 = ip0->src_address.data_u32;
347 dst0 = ip0->dst_address.data_u32;
348 ip0->src_address.data_u32 = dst0;
349 ip0->dst_address.data_u32 = src0;
358 ip4_tcp_reply_x2 (ip4_header_t * ip0, ip4_header_t * ip1,
359 tcp_header_t * tcp0, tcp_header_t * tcp1)
361 u32 src0, dst0, src1, dst1;
363 src0 = ip0->src_address.data_u32;
364 src1 = ip1->src_address.data_u32;
365 dst0 = ip0->dst_address.data_u32;
366 dst1 = ip1->dst_address.data_u32;
367 ip0->src_address.data_u32 = dst0;
368 ip1->src_address.data_u32 = dst1;
369 ip0->dst_address.data_u32 = src0;
370 ip1->dst_address.data_u32 = src1;
382 #endif /* included_ip4_packet_h */
385 * fd.io coding-style-patch-verification: ON
388 * eval: (c-set-style "gnu")