FD.io VPP  v21.01.1
Vector Packet Processing
ip4_inlines.h
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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/ip4.h: ip4 main include file
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_ip4_inlines_h
41 #define included_ip_ip4_inlines_h
42 
43 #include <vnet/ip/ip_flow_hash.h>
44 #include <vnet/ip/ip4_packet.h>
45 
46 #define IP_DF 0x4000 /* don't fragment */
47 
48 /* Compute flow hash. We'll use it to select which adjacency to use for this
49  flow. And other things. */
52  flow_hash_config_t flow_hash_config)
53 {
54  tcp_header_t *tcp = (void *) (ip + 1);
55  u32 a, b, c, t1, t2;
56  uword is_tcp_udp = (ip->protocol == IP_PROTOCOL_TCP
57  || ip->protocol == IP_PROTOCOL_UDP);
58 
59  t1 = (flow_hash_config & IP_FLOW_HASH_SRC_ADDR)
60  ? ip->src_address.data_u32 : 0;
61  t2 = (flow_hash_config & IP_FLOW_HASH_DST_ADDR)
62  ? ip->dst_address.data_u32 : 0;
63 
64  a = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t2 : t1;
65  b = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t1 : t2;
66 
67  t1 = is_tcp_udp ? tcp->src : 0;
68  t2 = is_tcp_udp ? tcp->dst : 0;
69 
70  t1 = (flow_hash_config & IP_FLOW_HASH_SRC_PORT) ? t1 : 0;
71  t2 = (flow_hash_config & IP_FLOW_HASH_DST_PORT) ? t2 : 0;
72 
73  if (flow_hash_config & IP_FLOW_HASH_SYMMETRIC)
74  {
75  if (b < a)
76  {
77  c = a;
78  a = b;
79  b = c;
80  }
81  if (t2 < t1)
82  {
83  t2 += t1;
84  t1 = t2 - t1;
85  t2 = t2 - t1;
86  }
87  }
88 
89  b ^= (flow_hash_config & IP_FLOW_HASH_PROTO) ? ip->protocol : 0;
90  c = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ?
91  (t1 << 16) | t2 : (t2 << 16) | t1;
92 
93  hash_v3_mix32 (a, b, c);
94  hash_v3_finalize32 (a, b, c);
95 
96  return c;
97 }
98 
99 always_inline void *
102  int proto, u8 csum_offload, u8 is_df)
103 {
104  ip4_header_t *ih;
105 
106  /* make some room */
107  ih = vlib_buffer_push_uninit (b, sizeof (ip4_header_t));
108 
109  ih->ip_version_and_header_length = 0x45;
110  ih->tos = 0;
111  ih->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
112 
113  /* No fragments */
114  ih->flags_and_fragment_offset = is_df ? clib_host_to_net_u16 (IP_DF) : 0;
115  ih->ttl = 255;
116  ih->protocol = proto;
117  ih->src_address.as_u32 = src->as_u32;
118  ih->dst_address.as_u32 = dst->as_u32;
119 
120  vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data;
121  b->flags |= VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L3_HDR_OFFSET_VALID;
122 
123  /* Offload ip4 header checksum generation */
124  if (csum_offload)
125  {
126  ih->checksum = 0;
127  b->flags |= VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
128  }
129  else
130  ih->checksum = ip4_header_checksum (ih);
131 
132  return ih;
133 }
134 
135 /**
136  * Push IPv4 header to buffer
137  *
138  * This does not support fragmentation.
139  *
140  * @param vm - vlib_main
141  * @param b - buffer to write the header to
142  * @param src - source IP
143  * @param dst - destination IP
144  * @param prot - payload proto
145  *
146  * @return - pointer to start of IP header
147  */
148 always_inline void *
151  u8 csum_offload)
152 {
153  return vlib_buffer_push_ip4_custom (vm, b, src, dst, proto, csum_offload,
154  1 /* is_df */ );
155 }
156 
157 #endif /* included_ip_ip4_inlines_h */
158 
159 /*
160  * fd.io coding-style-patch-verification: ON
161  *
162  * Local Variables:
163  * eval: (c-set-style "gnu")
164  * End:
165  */
u32 flags
buffer flags: VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index, VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:124
#define IP_FLOW_HASH_SYMMETRIC
Definition: ip_flow_hash.h:26
a
Definition: bitmap.h:544
ip4_address_t src_address
Definition: ip4_packet.h:125
static u32 ip4_compute_flow_hash(const ip4_header_t *ip, flow_hash_config_t flow_hash_config)
Definition: ip4_inlines.h:51
vl_api_address_t src
Definition: gre.api:54
vlib_main_t * vm
Definition: in2out_ed.c:1580
u16 flags_and_fragment_offset
Definition: ip4_packet.h:106
static uword vlib_buffer_length_in_chain(vlib_main_t *vm, vlib_buffer_t *b)
Get length in bytes of the buffer chain.
Definition: buffer_funcs.h:402
#define IP_FLOW_HASH_SRC_PORT
Definition: ip_flow_hash.h:23
struct _tcp_header tcp_header_t
#define hash_v3_mix32(a, b, c)
Definition: hash.h:554
unsigned char u8
Definition: types.h:56
ip4_address_t dst_address
Definition: ip4_packet.h:125
const cJSON *const b
Definition: cJSON.h:255
unsigned int u32
Definition: types.h:88
#define IP_FLOW_HASH_DST_ADDR
Definition: ip_flow_hash.h:21
vl_api_ip_proto_t proto
Definition: acl_types.api:51
#define IP_FLOW_HASH_DST_PORT
Definition: ip_flow_hash.h:24
#define always_inline
Definition: ipsec.h:28
vl_api_address_t dst
Definition: gre.api:55
static void * vlib_buffer_push_ip4_custom(vlib_main_t *vm, vlib_buffer_t *b, ip4_address_t *src, ip4_address_t *dst, int proto, u8 csum_offload, u8 is_df)
Definition: ip4_inlines.h:100
svmdb_client_t * c
u8 data[]
Packet data.
Definition: buffer.h:181
#define IP_FLOW_HASH_PROTO
Definition: ip_flow_hash.h:22
#define IP_DF
Definition: ip4_inlines.h:46
ip_dscp_t tos
Definition: ip4_packet.h:96
#define hash_v3_finalize32(a, b, c)
Definition: hash.h:564
static void * vlib_buffer_push_uninit(vlib_buffer_t *b, u8 size)
Prepend uninitialized data to buffer.
Definition: buffer.h:339
vl_api_address_t ip
Definition: l2.api:501
#define IP_FLOW_HASH_REVERSE_SRC_DST
Definition: ip_flow_hash.h:25
VLIB buffer representation.
Definition: buffer.h:102
u64 uword
Definition: types.h:112
#define IP_FLOW_HASH_SRC_ADDR
Flow hash configuration.
Definition: ip_flow_hash.h:20
#define vnet_buffer(b)
Definition: buffer.h:417
u32 flow_hash_config_t
A flow hash configuration is a mask of the flow hash options.
Definition: ip_flow_hash.h:43
u8 ip_version_and_header_length
Definition: ip4_packet.h:93
static void * vlib_buffer_push_ip4(vlib_main_t *vm, vlib_buffer_t *b, ip4_address_t *src, ip4_address_t *dst, int proto, u8 csum_offload)
Push IPv4 header to buffer.
Definition: ip4_inlines.h:149
static u16 ip4_header_checksum(ip4_header_t *i)
Definition: ip4_packet.h:314