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/ip/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. */
60 /* IP address must be first for ip_interface_address_get_address() to work */
61 ip4_address_t ip4_addr;
66 ip4_addr_fib_init (ip4_address_fib_t * addr_fib, ip4_address_t * address,
69 clib_memcpy (&addr_fib->ip4_addr, address, sizeof (addr_fib->ip4_addr));
70 addr_fib->fib_index = fib_index;
73 /* (src,dst) pair of addresses as found in packet header. */
76 ip4_address_t src, dst;
79 /* If address is a valid netmask, return length of mask. */
81 ip4_address_netmask_length (ip4_address_t * a)
85 for (i = 0; i < ARRAY_LEN (a->as_u8); i++)
117 /* Not a valid netmask mask. */
129 /* 4 bit packet length (in 32bit units) and version VVVVLLLL.
130 e.g. for packets w/ no options ip_version_and_header_length == 0x45. */
131 u8 ip_version_and_header_length;
133 /* Type of service. */
136 /* Total layer 3 packet length including this header. */
139 /* Fragmentation ID. */
142 /* 3 bits of flags and 13 bits of fragment offset (in units
143 of 8 byte quantities). */
144 u16 flags_and_fragment_offset;
145 #define IP4_HEADER_FLAG_MORE_FRAGMENTS (1 << 13)
146 #define IP4_HEADER_FLAG_DONT_FRAGMENT (1 << 14)
147 #define IP4_HEADER_FLAG_CONGESTION (1 << 15)
149 /* Time to live decremented by router at each hop. */
152 /* Next level protocol packet. */
158 /* Source and destination address. */
163 ip4_address_t src_address, dst_address;
165 ip4_address_pair_t address_pair;
169 /* For checksumming we'll want to access IP header in word sized chunks. */
170 /* For 64 bit machines. */
172 CLIB_PACKED (struct {
173 u64 checksum_data_64[2];
174 u32 checksum_data_64_32[1];
178 /* For 32 bit machines. */
180 CLIB_PACKED (struct {
181 u32 checksum_data_32[5];
186 /* Value of ip_version_and_header_length for packets w/o options. */
187 #define IP4_VERSION_AND_HEADER_LENGTH_NO_OPTIONS \
188 ((4 << 4) | (sizeof (ip4_header_t) / sizeof (u32)))
191 ip4_get_fragment_offset (ip4_header_t * i)
193 return clib_net_to_host_u16 (i->flags_and_fragment_offset) & 0x1fff;
197 ip4_get_fragment_more (ip4_header_t * i)
199 return clib_net_to_host_u16 (i->flags_and_fragment_offset) &
200 IP4_HEADER_FLAG_MORE_FRAGMENTS;
204 ip4_is_fragment (ip4_header_t * i)
206 return (i->flags_and_fragment_offset &
207 clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS));
211 ip4_is_first_fragment (ip4_header_t * i)
213 return (i->flags_and_fragment_offset &
214 clib_net_to_host_u16 (0x1fff | IP4_HEADER_FLAG_MORE_FRAGMENTS)) ==
215 clib_net_to_host_u16 (IP4_HEADER_FLAG_MORE_FRAGMENTS);
218 /* Fragment offset in bytes. */
220 ip4_get_fragment_offset_bytes (ip4_header_t * i)
222 return 8 * ip4_get_fragment_offset (i);
226 ip4_header_bytes (ip4_header_t * i)
228 return sizeof (u32) * (i->ip_version_and_header_length & 0xf);
232 ip4_next_header (ip4_header_t * i)
234 return (void *) i + ip4_header_bytes (i);
238 ip4_header_checksum (ip4_header_t * i)
245 sum = ip_incremental_checksum (0, i, ip4_header_bytes (i));
246 csum = ~ip_csum_fold (sum);
250 /* Make checksum agree for special case where either
251 0 or 0xffff would give same 1s complement sum. */
252 if (csum == 0 && save == 0xffff)
259 ip4_header_checksum_is_valid (ip4_header_t * i)
261 return i->checksum == ip4_header_checksum (i);
264 #define ip4_partial_header_checksum_x1(ip0,sum0) \
266 if (BITS (ip_csum_t) > 32) \
268 sum0 = ip0->checksum_data_64[0]; \
269 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
270 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
274 sum0 = ip0->checksum_data_32[0]; \
275 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
276 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
277 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
278 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
282 #define ip4_partial_header_checksum_x2(ip0,ip1,sum0,sum1) \
284 if (BITS (ip_csum_t) > 32) \
286 sum0 = ip0->checksum_data_64[0]; \
287 sum1 = ip1->checksum_data_64[0]; \
288 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64[1]); \
289 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64[1]); \
290 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_64_32[0]); \
291 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_64_32[0]); \
295 sum0 = ip0->checksum_data_32[0]; \
296 sum1 = ip1->checksum_data_32[0]; \
297 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[1]); \
298 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[1]); \
299 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[2]); \
300 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[2]); \
301 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[3]); \
302 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[3]); \
303 sum0 = ip_csum_with_carry (sum0, ip0->checksum_data_32[4]); \
304 sum1 = ip_csum_with_carry (sum1, ip1->checksum_data_32[4]); \
309 ip4_address_is_multicast (ip4_address_t * a)
311 return (a->data[0] & 0xf0) == 0xe0;
315 ip4_multicast_address_set_for_group (ip4_address_t * a,
316 ip_multicast_group_t g)
318 ASSERT ((u32) g < (1 << 28));
319 a->as_u32 = clib_host_to_net_u32 ((0xe << 28) + g);
323 ip4_multicast_ethernet_address (u8 * ethernet_address, ip4_address_t * a)
327 ethernet_address[0] = 0x01;
328 ethernet_address[1] = 0x00;
329 ethernet_address[2] = 0x5e;
330 ethernet_address[3] = d[1] & 0x7f;
331 ethernet_address[4] = d[2];
332 ethernet_address[5] = d[3];
336 ip4_tcp_reply_x1 (ip4_header_t * ip0, tcp_header_t * tcp0)
340 src0 = ip0->src_address.data_u32;
341 dst0 = ip0->dst_address.data_u32;
342 ip0->src_address.data_u32 = dst0;
343 ip0->dst_address.data_u32 = src0;
345 src0 = tcp0->ports.src;
346 dst0 = tcp0->ports.dst;
347 tcp0->ports.src = dst0;
348 tcp0->ports.dst = src0;
352 ip4_tcp_reply_x2 (ip4_header_t * ip0, ip4_header_t * ip1,
353 tcp_header_t * tcp0, tcp_header_t * tcp1)
355 u32 src0, dst0, src1, dst1;
357 src0 = ip0->src_address.data_u32;
358 src1 = ip1->src_address.data_u32;
359 dst0 = ip0->dst_address.data_u32;
360 dst1 = ip1->dst_address.data_u32;
361 ip0->src_address.data_u32 = dst0;
362 ip1->src_address.data_u32 = dst1;
363 ip0->dst_address.data_u32 = src0;
364 ip1->dst_address.data_u32 = src1;
366 src0 = tcp0->ports.src;
367 src1 = tcp1->ports.src;
368 dst0 = tcp0->ports.dst;
369 dst1 = tcp1->ports.dst;
370 tcp0->ports.src = dst0;
371 tcp1->ports.src = dst1;
372 tcp0->ports.dst = src0;
373 tcp1->ports.dst = src1;
376 #endif /* included_ip4_packet_h */
379 * fd.io coding-style-patch-verification: ON
382 * eval: (c-set-style "gnu")