FD.io VPP  v19.04.4-rc0-5-ge88582fac
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/udp/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  clib_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  ip_address_t * dst, u32 proto, u8 csum_offload)
147 {
148  if (ip_addr_version (src) != ip_addr_version (dst))
149  {
150  clib_warning ("src %U and dst %U IP have different AFI! Discarding!",
152  return 0;
153  }
154 
155  switch (ip_addr_version (src))
156  {
157  case IP4:
158  return vlib_buffer_push_ip4 (vm, b, &ip_addr_v4 (src),
159  &ip_addr_v4 (dst), proto, csum_offload);
160  break;
161  case IP6:
162  return vlib_buffer_push_ip6 (vm, b, &ip_addr_v6 (src),
163  &ip_addr_v6 (dst), proto);
164  break;
165  }
166 
167  return 0;
168 }
169 
170 void *
172  ip_address_t * sip, ip_address_t * dip, u8 csum_offload)
173 {
174  u16 udpsum;
175  udp_header_t *uh;
176  void *ih;
177 
178  uh = pkt_push_udp (vm, b, sp, dp);
179 
180  if (csum_offload)
181  {
182  ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 1);
183  b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
184  vnet_buffer (b)->l3_hdr_offset = (u8 *) ih - b->data;
185  vnet_buffer (b)->l4_hdr_offset = (u8 *) uh - b->data;
186  uh->checksum = 0;
187  }
188  else
189  {
190  ih = pkt_push_ip (vm, b, sip, dip, IP_PROTOCOL_UDP, 0);
191  udpsum = udp_checksum (uh, clib_net_to_host_u16 (uh->length), ih,
192  ip_addr_version (sip));
193  if (udpsum == (u16) ~ 0)
194  {
195  clib_warning ("Failed UDP checksum! Discarding");
196  return 0;
197  }
198  /* clear flags used for csum since we're not offloading */
199  b->flags &= ~(VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_IS_IP6);
200  uh->checksum = udpsum;
201  }
202  return ih;
203 }
204 
205 void *
207 {
208  ecm_hdr_t *h;
209  h = vlib_buffer_push_uninit (b, sizeof (h[0]));
210 
211  clib_memset (h, 0, sizeof (h[0]));
213  clib_memset (h->reserved2, 0, sizeof (h->reserved2));
214 
215  return h;
216 }
217 
218 /* *INDENT-ON* */
219 
220 /*
221  * fd.io coding-style-patch-verification: ON
222  *
223  * Local Variables:
224  * eval: (c-set-style "gnu")
225  * End:
226  */
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
boost::asio::ip::address ip_address_t
Definition: api_types.hpp:25
u16 udp_checksum(udp_header_t *uh, u32 udp_len, void *ih, u8 version)
Definition: packets.c:114
clib_memset(h->entries, 0, sizeof(h->entries[0]) *entries)
u8 data[0]
Packet data.
Definition: buffer.h:181
int i
vl_api_ip4_address_t dst
Definition: ipsec_gre.api:39
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:366
ip6_address_t src_address
Definition: ip6_packet.h:385
unsigned char u8
Definition: types.h:56
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, u8 csum_offload)
Definition: packets.c:145
u16 udp_ip6_checksum(ip6_header_t *ip6, udp_header_t *up, u32 len)
Definition: packets.c:69
unsigned int u32
Definition: types.h:88
#define ip_addr_v4(_a)
Definition: lisp_types.h:54
#define ip_addr_version(_a)
Definition: lisp_types.h:56
unsigned short u16
Definition: types.h:57
vl_api_address_union_t src_address
Definition: ip_types.api:44
vl_api_ip4_address_t src
Definition: ipsec_gre.api:38
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)
Definition: packets.c:171
#define ip_addr_v6(_a)
Definition: lisp_types.h:55
u8 len
Definition: ip_types.api:49
vlib_main_t * vm
Definition: buffer.c:312
#define clib_warning(format, args...)
Definition: error.h:59
u8 * format_ip_address(u8 *s, va_list *args)
Definition: lisp_types.c:144
option version
Definition: memclnt.api:17
static void * vlib_buffer_push_uninit(vlib_buffer_t *b, u8 size)
Prepend uninitialized data to buffer.
Definition: buffer.h:335
static void * vlib_buffer_push_ip6(vlib_main_t *vm, vlib_buffer_t *b, ip6_address_t *src, ip6_address_t *dst, int proto)
Push IPv6 header to buffer.
Definition: ip6.h:658
VLIB buffer representation.
Definition: buffer.h:102
Definition: lisp_types.h:37
#define vnet_buffer(b)
Definition: buffer.h:369
void * pkt_push_ecm_hdr(vlib_buffer_t *b)
Definition: packets.c:206
Definition: lisp_types.h:38
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.h:370
ip6_address_t dst_address
Definition: ip6_packet.h:385