aboutsummaryrefslogtreecommitdiffstats
path: root/vnet/vnet/ip/ip_packet.h
blob: d3f3de771bcf0d8cf0bf2c3406639859c7a99aba (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * ip/ip_packet.h: packet format common between ip4 & ip6
 *
 * Copyright (c) 2008 Eliot Dresselhaus
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef included_ip_packet_h
#define included_ip_packet_h

#include <vppinfra/byte_order.h>
#include <vppinfra/error.h>

typedef enum ip_protocol
{
#define ip_protocol(n,s) IP_PROTOCOL_##s = n,
#include "protocols.def"
#undef ip_protocol
} ip_protocol_t;

/* TCP/UDP ports. */
typedef enum
{
#define ip_port(s,n) IP_PORT_##s = n,
#include "ports.def"
#undef ip_port
} ip_port_t;

/* Classifies protocols into UDP, ICMP or other. */
typedef enum
{
  IP_BUILTIN_PROTOCOL_UDP,
  IP_BUILTIN_PROTOCOL_ICMP,
  IP_BUILTIN_PROTOCOL_UNKNOWN,
} ip_builtin_protocol_t;

#define foreach_ip_builtin_multicast_group	\
  _ (1, all_hosts_on_subnet)			\
  _ (2, all_routers_on_subnet)			\
  _ (4, dvmrp)					\
  _ (5, ospf_all_routers)			\
  _ (6, ospf_designated_routers)		\
  _ (13, pim)					\
  _ (18, vrrp)					\
  _ (102, hsrp)					\
  _ (22, igmp_v3)

typedef enum
{
#define _(n,f) IP_MULTICAST_GROUP_##f = n,
  foreach_ip_builtin_multicast_group
#undef _
} ip_multicast_group_t;

/* IP checksum support. */

/* Incremental checksum update. */
typedef uword ip_csum_t;

always_inline ip_csum_t
ip_csum_with_carry (ip_csum_t sum, ip_csum_t x)
{
  ip_csum_t t = sum + x;
  return t + (t < x);
}

/* Update checksum changing field at even byte offset from x -> 0. */
always_inline ip_csum_t
ip_csum_add_even (ip_csum_t c, ip_csum_t x)
{
  ip_csum_t d;

  d = c - x;

  /* Fold in carry from high bit. */
  d -= d > c;

  ASSERT (ip_csum_with_carry (d, x) == c);

  return d;
}

/* Update checksum changing field at even byte offset from 0 -> x. */
always_inline ip_csum_t
ip_csum_sub_even (ip_csum_t c, ip_csum_t x)
{
  return ip_csum_with_carry (c, x);
}

always_inline ip_csum_t
ip_csum_update_inline (ip_csum_t sum, ip_csum_t old, ip_csum_t new,
		       u32 field_byte_offset, u32 field_n_bytes)
{
  /* For even 1-byte fields on big-endian and odd 1-byte fields on little endian
     we need to shift byte into place for checksum. */
  if ((field_n_bytes % 2)
      && (field_byte_offset % 2) == CLIB_ARCH_IS_LITTLE_ENDIAN)
    {
      old = old << 8;
      new = new << 8;
    }
  sum = ip_csum_sub_even (sum, old);
  sum = ip_csum_add_even (sum, new);
  return sum;
}

#define ip_csum_update(sum,old,new,type,field)			\
  ip_csum_update_inline ((sum), (old), (new),			\
			 STRUCT_OFFSET_OF (type, field),	\
			 STRUCT_SIZE_OF (type, field))

always_inline u16
ip_csum_fold (ip_csum_t c)
{
  /* Reduce to 16 bits. */
#if uword_bits == 64
  c = (c & (ip_csum_t) 0xffffffff) + (c >> (ip_csum_t) 32);
  c = (c & 0xffff) + (c >> 16);
#endif

  c = (c & 0xffff) + (c >> 16);
  c = (c & 0xffff) + (c >> 16);

  return c;
}

/* Copy data and checksum at the same time. */
ip_csum_t ip_csum_and_memcpy (ip_csum_t sum, void *dst, void *src,
			      uword n_bytes);

always_inline u16
ip_csum_and_memcpy_fold (ip_csum_t sum, void *dst)
{
  return ip_csum_fold (sum);
}

/* Checksum routine. */
ip_csum_t ip_incremental_checksum (ip_csum_t sum, void *data, uword n_bytes);

#endif /* included_ip_packet_h */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */