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Vector Packet Processing
rewrite.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  * rewrite.h: packet rewrite
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_vnet_rewrite_h
41 #define included_vnet_rewrite_h
42 
43 #include <vlib/vlib.h>
44 #include <vnet/l3_types.h>
45 
46 /* Consider using vector types for speed? */
48 
49 /**
50  * Flags associated with the rewrite/adjacency
51  */
53 {
54  /**
55  * This adjacency/interface has output features configured
56  */
58 
59  /**
60  * this adj performs IP4 over IP4 fixup
61  */
63 } __attribute__ ((packed)) vnet_rewrite_flags_t;
64 
65 typedef struct vnet_rewrite_header_t_
66 {
67  /* Interface to mark re-written packets with. */
69 
70  /* Next node to feed after packet rewrite is done. */
72 
73  /* Number of bytes in rewrite data. */
75 
76  /* Max packet size layer 3 (MTU) for output interface.
77  Used for MTU check after packet rewrite. */
79 
80  /* Data-plane flags on the adjacency/rewrite */
82 
83  /* When dynamically writing a multicast destination L2 addresss
84  * this is the offset from the IP address at which to write in the
85  * IP->MAC address translation.
86  */
88 
89  /* Rewrite string starting at end and going backwards. */
90  u8 data[0];
91 } __clib_packed vnet_rewrite_header_t;
92 
93 /**
94  * At 16 bytes of rewrite herader we have enought space left for a IPv6
95  * (40 bytes) + LISP-GPE (8 bytes) in the cache line
96  */
97 STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16,
98  "Rewrite header too big");
99 
100 /*
101  Helper macro for declaring rewrite string w/ given max-size.
102 
103  Typical usage:
104  typedef struct {
105  //
106  int a, b;
107 
108  // Total adjacency is 64 bytes.
109  vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
110  } my_adjacency_t;
111 */
112 #define VNET_DECLARE_REWRITE \
113  struct \
114  { \
115  vnet_rewrite_header_t rewrite_header; \
116  \
117  u8 rewrite_data[(VNET_REWRITE_TOTAL_BYTES) - \
118  sizeof (vnet_rewrite_header_t)]; \
119  }
120 
121 typedef struct __rewrite_unused_t__
122 {
124 } __rewrite_unused_t;
125 
126 STATIC_ASSERT_SIZEOF (__rewrite_unused_t, 128);
127 
128 always_inline void
129 vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
130 {
131  /* Sanity check values carefully for this clib_memset operation */
132  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
133 
134  rw->data_bytes = 0;
135  clib_memset (rw->data, 0xfe, max_size);
136 }
137 
138 always_inline void
139 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
140  int max_size, void *data, int data_bytes)
141 {
142  /* Sanity check values carefully for this clib_memset operation */
143  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
144  ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
145 
146  rw->data_bytes = data_bytes;
147  clib_memcpy_fast (rw->data, data, data_bytes);
148  clib_memset (rw->data + data_bytes, 0xfe, max_size - data_bytes);
149 }
150 
151 #define vnet_rewrite_set_data(rw,data,data_bytes) \
152  vnet_rewrite_set_data_internal (&((rw).rewrite_header), \
153  sizeof ((rw).rewrite_data), \
154  (data), \
155  (data_bytes))
156 
157 always_inline void *
158 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
159 {
160  ASSERT (rw->data_bytes <= max_size);
161  return rw->data;
162 }
163 
164 #define vnet_rewrite_get_data(rw) \
165  vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
166 
167 always_inline void
168 _vnet_rewrite_one_header (const vnet_rewrite_header_t * h0,
169  void *packet0, int most_likely_size)
170 {
171  /* 0xfefe => poisoned adjacency => crash */
172  ASSERT (h0->data_bytes != 0xfefe);
173  if (PREDICT_TRUE (most_likely_size == h0->data_bytes))
174  {
175  clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
176  h0->data, most_likely_size);
177  }
178  else
179  {
180  clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
181  h0->data, h0->data_bytes);
182  }
183 }
184 
185 always_inline void
186 _vnet_rewrite_two_headers (const vnet_rewrite_header_t * h0,
187  const vnet_rewrite_header_t * h1,
188  void *packet0, void *packet1, int most_likely_size)
189 {
190  /* 0xfefe => poisoned adjacency => crash */
191  ASSERT (h0->data_bytes != 0xfefe);
192  ASSERT (h1->data_bytes != 0xfefe);
193  if (PREDICT_TRUE
194  (most_likely_size == h0->data_bytes
195  && most_likely_size == h1->data_bytes))
196  {
197  clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
198  h0->data, most_likely_size);
199  clib_memcpy_fast ((u8 *) packet1 - most_likely_size,
200  h1->data, most_likely_size);
201  }
202  else
203  {
204  clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
205  h0->data, h0->data_bytes);
206  clib_memcpy_fast ((u8 *) packet1 - h1->data_bytes,
207  h1->data, h1->data_bytes);
208  }
209 }
210 
211 #define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
212  _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
213  (most_likely_size))
214 
215 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
216  _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
217  (p0), (p1), \
218  (most_likely_size))
219 
220 always_inline void
222  u32 dst_mcast_offset, u32 * addr, u8 * packet0)
223 {
224  if (PREDICT_TRUE (0 != dst_mcast_offset))
225  {
226  /* location to write to in the packet */
227  u8 *p0 = packet0 - dst_mcast_offset;
228  u32 *p1 = (u32 *) p0;
229 
230  *p1 |= (*addr & dst_mcast_mask);
231  }
232 }
233 
234 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
235 /** Deprecated */
237  vnet_link_t packet_type,
239  u32 node_index,
240  void *dst_address,
241  vnet_rewrite_header_t * rw,
242  u32 max_rewrite_bytes);
243 
245  u32 sw_if_index);
246 
247 void vnet_rewrite_init (struct vnet_main_t *vnm,
249  vnet_link_t linkt,
250  u32 this_node,
251  u32 next_node, vnet_rewrite_header_t * rw);
252 
253 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
254  vnet_link_t linkt, vnet_rewrite_header_t * rw);
255 
258  vnet_link_t packet_type,
259  const void *dst_address);
261  u32 sw_if_index, u32 ai);
262 
264 
266 
267 #endif /* included_vnet_rewrite_h */
268 
269 /*
270  * fd.io coding-style-patch-verification: ON
271  *
272  * Local Variables:
273  * eval: (c-set-style "gnu")
274  * End:
275  */
u8 * vnet_build_rewrite_for_sw_interface(struct vnet_main_t *vnm, u32 sw_if_index, vnet_link_t packet_type, const void *dst_address)
Definition: rewrite.c:164
void vnet_update_adjacency_for_sw_interface(struct vnet_main_t *vnm, u32 sw_if_index, u32 ai)
Definition: rewrite.c:179
serialize_function_t unserialize_vnet_rewrite
Definition: rewrite.h:265
STATIC_ASSERT(sizeof(vnet_rewrite_header_t)<=16, "Rewrite header too big")
At 16 bytes of rewrite herader we have enought space left for a IPv6 (40 bytes) + LISP-GPE (8 bytes) ...
#define PREDICT_TRUE(x)
Definition: clib.h:119
#define clib_memcpy_fast(a, b, c)
Definition: string.h:81
uword vnet_rewrite_data_t
Definition: rewrite.h:47
clib_memset(h->entries, 0, sizeof(h->entries[0]) *entries)
#define VLIB_BUFFER_PRE_DATA_SIZE
Definition: buffer.h:51
void() serialize_function_t(serialize_main_t *m, va_list *va)
Definition: serialize.h:168
vhost_vring_addr_t addr
Definition: vhost_user.h:254
unsigned char u8
Definition: types.h:56
u8 *() format_function_t(u8 *s, va_list *args)
Definition: format.h:48
this adj performs IP4 over IP4 fixup
Definition: rewrite.h:62
static void vnet_rewrite_clear_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:129
unsigned int u32
Definition: types.h:88
void vnet_rewrite_init(struct vnet_main_t *vnm, u32 sw_if_index, vnet_link_t linkt, u32 this_node, u32 next_node, vnet_rewrite_header_t *rw)
Definition: rewrite.c:80
vnet_rewrite_flags_t flags
Definition: rewrite.h:81
format_function_t format_vnet_rewrite
Definition: rewrite.h:263
unsigned short u16
Definition: types.h:57
serialize_function_t serialize_vnet_rewrite
Definition: rewrite.h:265
#define VNET_DECLARE_REWRITE
Definition: rewrite.h:112
static void * vnet_rewrite_get_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:158
#define always_inline
Definition: ipsec.h:28
u32 vnet_tx_node_index_for_sw_interface(struct vnet_main_t *vnm, u32 sw_if_index)
Definition: rewrite.c:73
static void vnet_rewrite_set_data_internal(vnet_rewrite_header_t *rw, int max_size, void *data, int data_bytes)
Definition: rewrite.h:139
STATIC_ASSERT_SIZEOF(__rewrite_unused_t, 128)
#define ASSERT(truth)
enum vnet_link_t_ vnet_link_t
Link Type: A description of the protocol of packets on the link.
void vnet_rewrite_for_sw_interface(struct vnet_main_t *vnm, vnet_link_t packet_type, u32 sw_if_index, u32 node_index, void *dst_address, vnet_rewrite_header_t *rw, u32 max_rewrite_bytes)
Deprecated.
Definition: rewrite.c:101
static void vnet_ip_mcast_fixup_header(u32 dst_mcast_mask, u32 dst_mcast_offset, u32 *addr, u8 *packet0)
Definition: rewrite.h:221
u64 uword
Definition: types.h:112
enum vnet_rewrite_flags_t_ vnet_rewrite_flags_t
Flags associated with the rewrite/adjacency.
vnet_rewrite_flags_t_
Flags associated with the rewrite/adjacency.
Definition: rewrite.h:52
This adjacency/interface has output features configured.
Definition: rewrite.h:57
void vnet_rewrite_update_mtu(struct vnet_main_t *vnm, vnet_link_t linkt, vnet_rewrite_header_t *rw)
Definition: rewrite.c:92
struct vnet_rewrite_header_t_ vnet_rewrite_header_t