summaryrefslogtreecommitdiffstats
path: root/src/plugins/lisp/lisp-cp/packets.c
blob: 8e2386e72bdecd615bfe9816bd2da77dd90bb57e (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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/*
 * Copyright (c) 2016 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.
 */

#include <lisp/lisp-cp/packets.h>
#include <lisp/lisp-cp/lisp_cp_messages.h>
#include <vnet/udp/udp_packet.h>
#include <vnet/ip/ip4_inlines.h>
#include <vnet/ip/ip6_inlines.h>

/* Returns IP ID for the packet */
/* static u16 ip_id = 0;
static inline u16
get_IP_ID()
{
    ip_id++;
    return (ip_id);
} */

u16
udp_ip4_checksum (const void *b, u32 len, u8 * src, u8 * dst)
{
  const u16 *buf = b;
  u16 *ip_src = (u16 *) src;
  u16 *ip_dst = (u16 *) dst;
  u32 length = len;
  u32 sum = 0;

  while (len > 1)
    {
      sum += *buf++;
      if (sum & 0x80000000)
	sum = (sum & 0xFFFF) + (sum >> 16);
      len -= 2;
    }

  /* Add the padding if the packet length is odd */
  if (len & 1)
    sum += *((u8 *) buf);

  /* Add the pseudo-header */
  sum += *(ip_src++);
  sum += *ip_src;

  sum += *(ip_dst++);
  sum += *ip_dst;

  sum += clib_host_to_net_u16 (IP_PROTOCOL_UDP);
  sum += clib_host_to_net_u16 (length);

  /* Add the carries */
  while (sum >> 16)
    sum = (sum & 0xFFFF) + (sum >> 16);

  /* Return the one's complement of sum */
  return ((u16) (~sum));
}

u16
udp_ip6_checksum (ip6_header_t * ip6, udp_header_t * up, u32 len)
{
  size_t i;
  register const u16 *sp;
  u32 sum;
  union
  {
    struct
    {
      ip6_address_t ph_src;
      ip6_address_t ph_dst;
      u32 ph_len;
      u8 ph_zero[3];
      u8 ph_nxt;
    } ph;
    u16 pa[20];
  } phu;

  /* pseudo-header */
  clib_memset (&phu, 0, sizeof (phu));
  phu.ph.ph_src = ip6->src_address;
  phu.ph.ph_dst = ip6->dst_address;
  phu.ph.ph_len = clib_host_to_net_u32 (len);
  phu.ph.ph_nxt = IP_PROTOCOL_UDP;

  sum = 0;
  for (i = 0; i < sizeof (phu.pa) / sizeof (phu.pa[0]); i++)
    sum += phu.pa[i];

  sp = (const u16 *) up;

  for (i = 0; i < (len & ~1); i += 2)
    sum += *sp++;

  if (len & 1)
    sum += clib_host_to_net_u16 ((*(const u8 *) sp) << 8);

  while (sum > 0xffff)
    sum = (sum & 0xffff) + (sum >> 16);
  sum = ~sum & 0xffff;

  return (sum);
}

u16
udp_checksum (udp_header_t * uh, u32 udp_len, void *ih, u8 version)
{
  switch (version)
    {
    case AF_IP4:
      return (udp_ip4_checksum (uh, udp_len,
				((ip4_header_t *) ih)->src_address.as_u8,
				((ip4_header_t *) ih)->dst_address.as_u8));
    case AF_IP6:
      return (udp_ip6_checksum (ih, uh, udp_len));
    default:
      return ~0;
    }
}

void *
pkt_push_udp (vlib_main_t * vm, vlib_buffer_t * b, u16 sp, u16 dp)
{
  udp_header_t *uh;
  u16 udp_len = sizeof (udp_header_t) + vlib_buffer_length_in_chain (vm, b);

  uh = vlib_buffer_push_uninit (b, sizeof (*uh));

  uh->src_port = clib_host_to_net_u16 (sp);
  uh->dst_port = clib_host_to_net_u16 (dp);
  uh->length = clib_host_to_net_u16 (udp_len);
  uh->checksum = 0;
  return uh;
}

void *
pkt_push_ip (vlib_main_t * vm, vlib_buffer_t * b, ip_address_t * src,
	     ip_address_t * dst, u32 proto, u8 csum_offload)
{
  if (ip_addr_version (src) != ip_addr_version (dst))
    {
      clib_warning ("src %U and dst %U IP have different AFI! Discarding!",
		    format_ip_address, src, format_ip_address, dst);
      return 0;
    }

  switch (ip_addr_version (src))
    {
    case AF_IP4:
      return vlib_buffer_push_ip4 (vm, b, &ip_addr_v4 (src),
				   &ip_addr_v4 (dst), proto, csum_offload);
      break;
    case AF_IP6:
      return vlib_buffer_push_ip6 (vm, b, &ip_addr_v6 (src),
				   &ip_addr_v6 (dst), proto);
      break;
    }

  return 0;
}

void *
pkt_push_udp_and_ip (vlib_main_t * vm, vlib_buffer_t * b, u16 sp, u16 dp,
		     ip_address_t * sip, ip_address_t * dip, u8 csum_offload)
{
  u16 udpsum;
  udp_header_t *uh;
  void *ih;

  uh = pkt_push_udp (vm, b, sp, dp);

  if (csum_offload)
    {
      ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 1);
      b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
      vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data;
      vnet_buffer (b)->l4_hdr_offset = (u8 *) uh - b->data;
      uh->checksum = 0;
    }
  else
    {
      ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 0);
      udpsum = udp_checksum (uh, clib_net_to_host_u16 (uh->length), ih,
			     ip_addr_version (sip));
      if (udpsum == (u16) ~ 0)
	{
	  clib_warning ("Failed UDP checksum! Discarding");
	  return 0;
	}
      /* clear flags used for csum since we're not offloading */
      b->flags &= ~(VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_IS_IP6);
      uh->checksum = udpsum;
    }
  return ih;
}

void *
pkt_push_ecm_hdr (vlib_buffer_t * b)
{
  ecm_hdr_t *h;
  h = vlib_buffer_push_uninit (b, sizeof (h[0]));

  clib_memset (h, 0, sizeof (h[0]));
  h->type = LISP_ENCAP_CONTROL_TYPE;
  clib_memset (h->reserved2, 0, sizeof (h->reserved2));

  return h;
}

/* *INDENT-ON* */

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