FD.io VPP  v17.01-9-ge7dcee4
Vector Packet Processing
packets.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2016 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 #include <vnet/lisp-cp/packets.h>
18 #include <vnet/ip/udp_packet.h>
19 
20 /* Returns IP ID for the packet */
21 /* static u16 ip_id = 0;
22 static inline u16
23 get_IP_ID()
24 {
25  ip_id++;
26  return (ip_id);
27 } */
28 
29 u16
30 udp_ip4_checksum (const void *b, u32 len, u8 * src, u8 * dst)
31 {
32  const u16 *buf = b;
33  u16 *ip_src = (u16 *) src;
34  u16 *ip_dst = (u16 *) dst;
35  u32 length = len;
36  u32 sum = 0;
37 
38  while (len > 1)
39  {
40  sum += *buf++;
41  if (sum & 0x80000000)
42  sum = (sum & 0xFFFF) + (sum >> 16);
43  len -= 2;
44  }
45 
46  /* Add the padding if the packet length is odd */
47  if (len & 1)
48  sum += *((u8 *) buf);
49 
50  /* Add the pseudo-header */
51  sum += *(ip_src++);
52  sum += *ip_src;
53 
54  sum += *(ip_dst++);
55  sum += *ip_dst;
56 
57  sum += clib_host_to_net_u16 (IP_PROTOCOL_UDP);
58  sum += clib_host_to_net_u16 (length);
59 
60  /* Add the carries */
61  while (sum >> 16)
62  sum = (sum & 0xFFFF) + (sum >> 16);
63 
64  /* Return the one's complement of sum */
65  return ((u16) (~sum));
66 }
67 
68 u16
70 {
71  size_t i;
72  register const u16 *sp;
73  u32 sum;
74  union
75  {
76  struct
77  {
78  ip6_address_t ph_src;
79  ip6_address_t ph_dst;
80  u32 ph_len;
81  u8 ph_zero[3];
82  u8 ph_nxt;
83  } ph;
84  u16 pa[20];
85  } phu;
86 
87  /* pseudo-header */
88  memset (&phu, 0, sizeof (phu));
89  phu.ph.ph_src = ip6->src_address;
90  phu.ph.ph_dst = ip6->dst_address;
91  phu.ph.ph_len = clib_host_to_net_u32 (len);
92  phu.ph.ph_nxt = IP_PROTOCOL_UDP;
93 
94  sum = 0;
95  for (i = 0; i < sizeof (phu.pa) / sizeof (phu.pa[0]); i++)
96  sum += phu.pa[i];
97 
98  sp = (const u16 *) up;
99 
100  for (i = 0; i < (len & ~1); i += 2)
101  sum += *sp++;
102 
103  if (len & 1)
104  sum += clib_host_to_net_u16 ((*(const u8 *) sp) << 8);
105 
106  while (sum > 0xffff)
107  sum = (sum & 0xffff) + (sum >> 16);
108  sum = ~sum & 0xffff;
109 
110  return (sum);
111 }
112 
113 u16
114 udp_checksum (udp_header_t * uh, u32 udp_len, void *ih, u8 version)
115 {
116  switch (version)
117  {
118  case IP4:
119  return (udp_ip4_checksum (uh, udp_len,
120  ((ip4_header_t *) ih)->src_address.as_u8,
121  ((ip4_header_t *) ih)->dst_address.as_u8));
122  case IP6:
123  return (udp_ip6_checksum (ih, uh, udp_len));
124  default:
125  return ~0;
126  }
127 }
128 
129 void *
131 {
132  udp_header_t *uh;
133  u16 udp_len = sizeof (udp_header_t) + vlib_buffer_length_in_chain (vm, b);
134 
135  uh = vlib_buffer_push_uninit (b, sizeof (*uh));
136 
137  uh->src_port = clib_host_to_net_u16 (sp);
138  uh->dst_port = clib_host_to_net_u16 (dp);
139  uh->length = clib_host_to_net_u16 (udp_len);
140  uh->checksum = 0;
141  return uh;
142 }
143 
144 void *
146  ip4_address_t * dst, int proto)
147 {
148  ip4_header_t *ih;
149 
150  /* make some room */
151  ih = vlib_buffer_push_uninit (b, sizeof (ip4_header_t));
152 
153  ih->ip_version_and_header_length = 0x45;
154  ih->tos = 0;
155  ih->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b));
156 
157  /* iph->fragment_id = clib_host_to_net_u16(get_IP_ID ()); */
158 
159  /* TODO: decide if we allow fragments in case of control */
160  ih->flags_and_fragment_offset = clib_host_to_net_u16 (IP_DF);
161  ih->ttl = 255;
162  ih->protocol = proto;
163  ih->src_address.as_u32 = src->as_u32;
164  ih->dst_address.as_u32 = dst->as_u32;
165 
166  ih->checksum = ip4_header_checksum (ih);
167  return ih;
168 }
169 
170 void *
172  ip6_address_t * dst, int proto)
173 {
174  ip6_header_t *ip6h;
175  u16 payload_length;
176 
177  /* make some room */
178  ip6h = vlib_buffer_push_uninit (b, sizeof (ip6_header_t));
179 
181  clib_host_to_net_u32 (0x6 << 28);
182 
183  /* calculate ip6 payload length */
184  payload_length = vlib_buffer_length_in_chain (vm, b);
185  payload_length -= sizeof (*ip6h);
186 
187  ip6h->payload_length = clib_host_to_net_u16 (payload_length);
188 
189  ip6h->hop_limit = 0xff;
190  ip6h->protocol = proto;
191  clib_memcpy (ip6h->src_address.as_u8, src->as_u8,
192  sizeof (ip6h->src_address));
193  clib_memcpy (ip6h->dst_address.as_u8, dst->as_u8,
194  sizeof (ip6h->src_address));
195 
196  return ip6h;
197 }
198 
199 void *
200 pkt_push_ip (vlib_main_t * vm, vlib_buffer_t * b, ip_address_t * src,
201  ip_address_t * dst, u32 proto)
202 {
203  if (ip_addr_version (src) != ip_addr_version (dst))
204  {
205  clib_warning ("src %U and dst %U IP have different AFI! Discarding!",
207  return 0;
208  }
209 
210  switch (ip_addr_version (src))
211  {
212  case IP4:
213  return pkt_push_ipv4 (vm, b, &ip_addr_v4 (src), &ip_addr_v4 (dst),
214  proto);
215  break;
216  case IP6:
217  return pkt_push_ipv6 (vm, b, &ip_addr_v6 (src), &ip_addr_v6 (dst),
218  proto);
219  break;
220  }
221 
222  return 0;
223 }
224 
225 void *
227  ip_address_t * sip, ip_address_t * dip)
228 {
229  u16 udpsum;
230  udp_header_t *uh;
231  void *ih;
232 
233  uh = pkt_push_udp (vm, b, sp, dp);
234 
235  ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP);
236 
237  udpsum = udp_checksum (uh, clib_net_to_host_u16 (uh->length), ih,
238  ip_addr_version (sip));
239  if (udpsum == (u16) ~ 0)
240  {
241  clib_warning ("Failed UDP checksum! Discarding");
242  return 0;
243  }
244  uh->checksum = udpsum;
245  return ih;
246 }
247 
248 void *
250 {
251  ecm_hdr_t *h;
252  h = vlib_buffer_push_uninit (b, sizeof (h[0]));
253 
254  memset (h, 0, sizeof (h[0]));
256  memset (h->reserved2, 0, sizeof (h->reserved2));
257 
258  return h;
259 }
260 
261 /* *INDENT-ON* */
262 
263 /*
264  * fd.io coding-style-patch-verification: ON
265  *
266  * Local Variables:
267  * eval: (c-set-style "gnu")
268  * End:
269  */
sll srl srl sll sra u16x4 i
Definition: vector_sse2.h:343
u16 udp_checksum(udp_header_t *uh, u32 udp_len, void *ih, u8 version)
Definition: packets.c:114
ip4_address_t src_address
Definition: ip4_packet.h:163
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)
Definition: packets.c:226
u8 as_u8[16]
Definition: ip6_packet.h:48
void * pkt_push_ipv4(vlib_main_t *vm, vlib_buffer_t *b, ip4_address_t *src, ip4_address_t *dst, int proto)
Definition: packets.c:145
static void * vlib_buffer_push_uninit(vlib_buffer_t *b, u8 size)
Definition: packets.h:45
u16 flags_and_fragment_offset
Definition: ip4_packet.h:144
u16 udp_ip4_checksum(const void *b, u32 len, u8 *src, u8 *dst)
Definition: packets.c:30
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:100
ip6_address_t src_address
Definition: ip6_packet.h:337
void * pkt_push_udp(vlib_main_t *vm, vlib_buffer_t *b, u16 sp, u16 dp)
Definition: packets.c:130
void * pkt_push_ip(vlib_main_t *vm, vlib_buffer_t *b, ip_address_t *src, ip_address_t *dst, u32 proto)
Definition: packets.c:200
ip4_address_t dst_address
Definition: ip4_packet.h:163
#define IP_DF
Definition: packets.h:19
#define clib_warning(format, args...)
Definition: error.h:59
u16 udp_ip6_checksum(ip6_header_t *ip6, udp_header_t *up, u32 len)
Definition: packets.c:69
#define ip_addr_v4(_a)
Definition: lisp_types.h:54
#define ip_addr_version(_a)
Definition: lisp_types.h:56
void * pkt_push_ipv6(vlib_main_t *vm, vlib_buffer_t *b, ip6_address_t *src, ip6_address_t *dst, int proto)
Definition: packets.c:171
#define ip_addr_v6(_a)
Definition: lisp_types.h:55
#define clib_memcpy(a, b, c)
Definition: string.h:69
unsigned int u32
Definition: types.h:88
u8 * format_ip_address(u8 *s, va_list *args)
Definition: lisp_types.c:127
u32 ip_version_traffic_class_and_flow_label
Definition: ip6_packet.h:324
unsigned short u16
Definition: types.h:57
u16 payload_length
Definition: ip6_packet.h:328
unsigned char u8
Definition: types.h:56
Definition: lisp_types.h:37
u8 ip_version_and_header_length
Definition: ip4_packet.h:131
void * pkt_push_ecm_hdr(vlib_buffer_t *b)
Definition: packets.c:249
Definition: lisp_types.h:38
static u16 ip4_header_checksum(ip4_header_t *i)
Definition: ip4_packet.h:238
ip6_address_t dst_address
Definition: ip6_packet.h:337