FD.io VPP  v17.04-9-g99c0734
Vector Packet Processing
ip_packet.h
Go to the documentation of this file.
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  * ip/ip_packet.h: packet format common between ip4 & ip6
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_ip_packet_h
41 #define included_ip_packet_h
42 
43 #include <vppinfra/byte_order.h>
44 #include <vppinfra/error.h>
45 
46 typedef enum ip_protocol
47 {
48 #define ip_protocol(n,s) IP_PROTOCOL_##s = n,
49 #include "protocols.def"
50 #undef ip_protocol
52 
53 /* TCP/UDP ports. */
54 typedef enum
55 {
56 #define ip_port(s,n) IP_PORT_##s = n,
57 #include "ports.def"
58 #undef ip_port
59 } ip_port_t;
60 
61 /* Classifies protocols into UDP, ICMP or other. */
62 typedef enum
63 {
68 
69 #define foreach_ip_builtin_multicast_group \
70  _ (1, all_hosts_on_subnet) \
71  _ (2, all_routers_on_subnet) \
72  _ (4, dvmrp) \
73  _ (5, ospf_all_routers) \
74  _ (6, ospf_designated_routers) \
75  _ (13, pim) \
76  _ (18, vrrp) \
77  _ (102, hsrp) \
78  _ (22, igmp_v3)
79 
80 typedef enum
81 {
82 #define _(n,f) IP_MULTICAST_GROUP_##f = n,
84 #undef _
86 
87 /* IP checksum support. */
88 
89 /* Incremental checksum update. */
90 typedef uword ip_csum_t;
91 
94 {
95  ip_csum_t t = sum + x;
96  return t + (t < x);
97 }
98 
99 /* Update checksum changing field at even byte offset from x -> 0. */
102 {
103  ip_csum_t d;
104 
105  d = c - x;
106 
107  /* Fold in carry from high bit. */
108  d -= d > c;
109 
110  ASSERT (ip_csum_with_carry (d, x) == c);
111 
112  return d;
113 }
114 
115 /* Update checksum changing field at even byte offset from 0 -> x. */
118 {
119  return ip_csum_with_carry (c, x);
120 }
121 
124  u32 field_byte_offset, u32 field_n_bytes)
125 {
126  /* For even 1-byte fields on big-endian and odd 1-byte fields on little endian
127  we need to shift byte into place for checksum. */
128  if ((field_n_bytes % 2)
129  && (field_byte_offset % 2) == CLIB_ARCH_IS_LITTLE_ENDIAN)
130  {
131  old = old << 8;
132  new = new << 8;
133  }
134  sum = ip_csum_sub_even (sum, old);
135  sum = ip_csum_add_even (sum, new);
136  return sum;
137 }
138 
139 #define ip_csum_update(sum,old,new,type,field) \
140  ip_csum_update_inline ((sum), (old), (new), \
141  STRUCT_OFFSET_OF (type, field), \
142  STRUCT_SIZE_OF (type, field))
143 
146 {
147  /* Reduce to 16 bits. */
148 #if uword_bits == 64
149  c = (c & (ip_csum_t) 0xffffffff) + (c >> (ip_csum_t) 32);
150  c = (c & 0xffff) + (c >> 16);
151 #endif
152 
153  c = (c & 0xffff) + (c >> 16);
154  c = (c & 0xffff) + (c >> 16);
155 
156  return c;
157 }
158 
159 /* Copy data and checksum at the same time. */
160 ip_csum_t ip_csum_and_memcpy (ip_csum_t sum, void *dst, void *src,
161  uword n_bytes);
162 
165 {
166  return ip_csum_fold (sum);
167 }
168 
169 /* Checksum routine. */
170 ip_csum_t ip_incremental_checksum (ip_csum_t sum, void *data, uword n_bytes);
171 
172 #endif /* included_ip_packet_h */
173 
174 /*
175  * fd.io coding-style-patch-verification: ON
176  *
177  * Local Variables:
178  * eval: (c-set-style "gnu")
179  * End:
180  */
#define CLIB_ARCH_IS_LITTLE_ENDIAN
Definition: byte_order.h:45
uword ip_csum_t
Definition: ip_packet.h:90
static ip_csum_t ip_csum_with_carry(ip_csum_t sum, ip_csum_t x)
Definition: ip_packet.h:93
static u16 ip_csum_and_memcpy_fold(ip_csum_t sum, void *dst)
Definition: ip_packet.h:164
#define always_inline
Definition: clib.h:84
static 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)
Definition: ip_packet.h:123
enum ip_protocol ip_protocol_t
svmdb_client_t * c
ip_csum_t ip_incremental_checksum(ip_csum_t sum, void *data, uword n_bytes)
Definition: ip_checksum.c:43
ip_protocol
Definition: ip_packet.h:46
ip_port_t
Definition: ip_packet.h:54
#define ASSERT(truth)
unsigned int u32
Definition: types.h:88
static ip_csum_t ip_csum_sub_even(ip_csum_t c, ip_csum_t x)
Definition: ip_packet.h:117
ip_csum_t ip_csum_and_memcpy(ip_csum_t sum, void *dst, void *src, uword n_bytes)
Definition: ip_checksum.c:110
u64 uword
Definition: types.h:112
unsigned short u16
Definition: types.h:57
#define foreach_ip_builtin_multicast_group
Definition: ip_packet.h:69
ip_multicast_group_t
Definition: ip_packet.h:80
ip_builtin_protocol_t
Definition: ip_packet.h:62
static u16 ip_csum_fold(ip_csum_t c)
Definition: ip_packet.h:145
static ip_csum_t ip_csum_add_even(ip_csum_t c, ip_csum_t x)
Definition: ip_packet.h:101