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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 } __attribute__ ((packed)) vnet_rewrite_flags_t;
59 
60 /* *INDENT-OFF* */
61 typedef CLIB_PACKED (struct {
62  /* Interface to mark re-written packets with. */
64 
65  /* Next node to feed after packet rewrite is done. */
66  u16 next_index;
67 
68  /* Number of bytes in rewrite data. */
69  u16 data_bytes;
70 
71  /* Max packet size layer 3 (MTU) for output interface.
72  Used for MTU check after packet rewrite. */
73  u16 max_l3_packet_bytes;
74 
75  /* Data-plane flags on the adjacency/rewrite */
77 
78  /* When dynamically writing a multicast destination L2 addresss
79  * this is the offset from the IP address at which to write in the
80  * IP->MAC address translation.
81  */
82  u8 dst_mcast_offset;
83 
84  /* Rewrite string starting at end and going backwards. */
85  u8 data[0];
86 }) vnet_rewrite_header_t;
87 /* *INDENT-ON* */
88 
89 /**
90  * At 16 bytes of rewrite herader we have enought space left for a IPv6
91  * (40 bytes) + LISP-GPE (8 bytes) in the cache line
92  */
93 STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16,
94  "Rewrite header too big");
95 
96 /*
97  Helper macro for declaring rewrite string w/ given max-size.
98 
99  Typical usage:
100  typedef struct {
101  //
102  int a, b;
103 
104  // Total adjacency is 64 bytes.
105  vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
106  } my_adjacency_t;
107 */
108 #define vnet_declare_rewrite(total_bytes) \
109 struct { \
110  vnet_rewrite_header_t rewrite_header; \
111  \
112  u8 rewrite_data[(total_bytes) - sizeof (vnet_rewrite_header_t)]; \
113 }
114 
115 always_inline void
116 vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
117 {
118  /* Sanity check values carefully for this memset operation */
119  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
120 
121  rw->data_bytes = 0;
122  memset (rw->data, 0xfe, max_size);
123 }
124 
125 always_inline void
126 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
127  int max_size, void *data, int data_bytes)
128 {
129  /* Sanity check values carefully for this memset operation */
130  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
131  ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
132 
133  rw->data_bytes = data_bytes;
134  clib_memcpy (rw->data + max_size - data_bytes, data, data_bytes);
135  memset (rw->data, 0xfe, max_size - data_bytes);
136 }
137 
138 #define vnet_rewrite_set_data(rw,data,data_bytes) \
139  vnet_rewrite_set_data_internal (&((rw).rewrite_header), \
140  sizeof ((rw).rewrite_data), \
141  (data), \
142  (data_bytes))
143 
144 always_inline void *
145 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
146 {
147  ASSERT (rw->data_bytes <= max_size);
148  return rw->data + max_size - rw->data_bytes;
149 }
150 
151 #define vnet_rewrite_get_data(rw) \
152  vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
153 
154 always_inline void
155 vnet_rewrite_copy_one (vnet_rewrite_data_t * p0, vnet_rewrite_data_t * rw0,
156  int i)
157 {
158  p0[-i] = rw0[-i];
159 }
160 
161 void vnet_rewrite_copy_slow_path (vnet_rewrite_data_t * p0,
162  vnet_rewrite_data_t * rw0,
163  word n_left, uword most_likely_size);
164 
165 /* *INDENT-OFF* */
166 typedef CLIB_PACKED (struct {
167  u64 a;
168  u32 b;
169  u16 c;
170 }) eh_copy_t;
171 /* *INDENT-ON* */
172 
173 always_inline void
174 _vnet_rewrite_one_header (vnet_rewrite_header_t * h0,
175  void *packet0, int max_size, int most_likely_size)
176 {
177  vnet_rewrite_data_t *p0 = packet0;
178  vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
179  word n_left0;
180 
181  /* 0xfefe => poisoned adjacency => crash */
182  ASSERT (h0->data_bytes != 0xfefe);
183 
184  if (PREDICT_TRUE (h0->data_bytes == sizeof (eh_copy_t)))
185  {
186  eh_copy_t *s, *d;
187  s = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
188  d = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
189  clib_memcpy (d, s, sizeof (eh_copy_t));
190  return;
191  }
192 
193 
194 #define _(i) \
195  do { \
196  if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
197  vnet_rewrite_copy_one (p0, rw0, (i)); \
198  } while (0)
199 
200  _(4);
201  _(3);
202  _(2);
203  _(1);
204 
205 #undef _
206 
207  n_left0 = (int)
208  (((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
209  / (int) sizeof (rw0[0]);
210  if (PREDICT_FALSE (n_left0 > 0))
211  vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
212 }
213 
214 always_inline void
215 _vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
216  vnet_rewrite_header_t * h1,
217  void *packet0,
218  void *packet1, int max_size, int most_likely_size)
219 {
220  vnet_rewrite_data_t *p0 = packet0;
221  vnet_rewrite_data_t *p1 = packet1;
222  vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
223  vnet_rewrite_data_t *rw1 = (vnet_rewrite_data_t *) (h1->data + max_size);
224  word n_left0, n_left1;
225  int slow_path;
226 
227  /* 0xfefe => poisoned adjacency => crash */
228  ASSERT (h0->data_bytes != 0xfefe);
229  ASSERT (h1->data_bytes != 0xfefe);
230 
231  /* Arithmetic calculation: bytes0 == bytes1 == 14 */
232  slow_path = h0->data_bytes ^ h1->data_bytes;
233  slow_path += h0->data_bytes ^ sizeof (eh_copy_t);
234 
235  if (PREDICT_TRUE (slow_path == 0))
236  {
237  eh_copy_t *s0, *d0, *s1, *d1;
238  s0 = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
239  d0 = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
240  clib_memcpy (d0, s0, sizeof (eh_copy_t));
241  s1 = (eh_copy_t *) (h1->data + max_size - sizeof (eh_copy_t));
242  d1 = (eh_copy_t *) (((u8 *) packet1) - sizeof (eh_copy_t));
243  clib_memcpy (d1, s1, sizeof (eh_copy_t));
244  return;
245  }
246 
247 #define _(i) \
248  do { \
249  if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
250  { \
251  vnet_rewrite_copy_one (p0, rw0, (i)); \
252  vnet_rewrite_copy_one (p1, rw1, (i)); \
253  } \
254  } while (0)
255 
256  _(4);
257  _(3);
258  _(2);
259  _(1);
260 
261 #undef _
262 
263  n_left0 = (int)
264  (((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
265  / (int) sizeof (rw0[0]);
266  n_left1 = (int)
267  (((int) h1->data_bytes - most_likely_size) + (sizeof (rw1[0]) - 1))
268  / (int) sizeof (rw1[0]);
269 
270  if (PREDICT_FALSE (n_left0 > 0 || n_left1 > 0))
271  {
272  vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
273  vnet_rewrite_copy_slow_path (p1, rw1, n_left1, most_likely_size);
274  }
275 }
276 
277 #define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
278  _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
279  sizeof ((rw0).rewrite_data), \
280  (most_likely_size))
281 
282 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
283  _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
284  (p0), (p1), \
285  sizeof ((rw0).rewrite_data), \
286  (most_likely_size))
287 
288 always_inline void
290  u32 dst_mcast_offset, u32 * addr, u8 * packet0)
291 {
292  if (PREDICT_TRUE (0 != dst_mcast_offset))
293  {
294  /* location to write to in the packet */
295  u8 *p0 = packet0 - dst_mcast_offset;
296  u32 *p1 = (u32 *) p0;
297 
298  *p1 |= (*addr & dst_mcast_mask);
299  }
300 }
301 
302 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
303 /** Deprecated */
305  vnet_link_t packet_type,
307  u32 node_index,
308  void *dst_address,
309  vnet_rewrite_header_t * rw,
310  u32 max_rewrite_bytes);
311 
313  u32 sw_if_index);
314 
315 void vnet_rewrite_init (struct vnet_main_t *vnm,
317  vnet_link_t linkt,
318  u32 this_node,
319  u32 next_node, vnet_rewrite_header_t * rw);
320 
321 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
322  vnet_link_t linkt, vnet_rewrite_header_t * rw);
323 
326  vnet_link_t packet_type,
327  const void *dst_address);
329  u32 sw_if_index, u32 ai);
330 
332 
334 
335 #endif /* included_vnet_rewrite_h */
336 
337 /*
338  * fd.io coding-style-patch-verification: ON
339  *
340  * Local Variables:
341  * eval: (c-set-style "gnu")
342  * End:
343  */
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:213
void vnet_update_adjacency_for_sw_interface(struct vnet_main_t *vnm, u32 sw_if_index, u32 ai)
Definition: rewrite.c:228
a
Definition: bitmap.h:538
serialize_function_t unserialize_vnet_rewrite
Definition: rewrite.h:333
#define PREDICT_TRUE(x)
Definition: clib.h:108
unsigned long u64
Definition: types.h:89
uword vnet_rewrite_data_t
Definition: rewrite.h:47
#define VLIB_BUFFER_PRE_DATA_SIZE
Definition: buffer.h:52
int i
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
vhost_vring_addr_t addr
Definition: vhost_user.h:121
unsigned char u8
Definition: types.h:56
memset(h->entries, 0, sizeof(h->entries[0])*entries)
i64 word
Definition: types.h:111
static u32 slow_path(dslite_main_t *dm, dslite_session_key_t *in2out_key, dslite_session_t **sp, u32 next, u8 *error, u32 thread_index)
Definition: dslite_in2out.c:37
u32 sw_if_index
Definition: vxlan_gbp.api:39
#define always_inline
Definition: clib.h:94
static void vnet_rewrite_clear_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:116
static void vnet_rewrite_copy_one(vnet_rewrite_data_t *p0, vnet_rewrite_data_t *rw0, int i)
Definition: rewrite.h:155
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:104
format_function_t format_vnet_rewrite
Definition: rewrite.h:331
unsigned short u16
Definition: types.h:57
serialize_function_t serialize_vnet_rewrite
Definition: rewrite.h:333
static void * vnet_rewrite_get_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:145
#define PREDICT_FALSE(x)
Definition: clib.h:107
void vnet_rewrite_copy_slow_path(vnet_rewrite_data_t *p0, vnet_rewrite_data_t *rw0, word n_left, uword most_likely_size)
Definition: rewrite.c:44
u32 flags
Definition: vhost_user.h:115
svmdb_client_t * c
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) ...
u32 vnet_tx_node_index_for_sw_interface(struct vnet_main_t *vnm, u32 sw_if_index)
Definition: rewrite.c:97
static void vnet_rewrite_set_data_internal(vnet_rewrite_header_t *rw, int max_size, void *data, int data_bytes)
Definition: rewrite.h:126
#define clib_memcpy(a, b, c)
Definition: string.h:75
#define ASSERT(truth)
enum vnet_link_t_ vnet_link_t
Link Type: A description of the protocol of packets on the link.
typedef CLIB_PACKED(struct{u32 sw_if_index;u16 next_index;u16 data_bytes;u16 max_l3_packet_bytes;vnet_rewrite_flags_t flags;u8 dst_mcast_offset;u8 data[0];}) vnet_rewrite_header_t
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:125
static void vnet_ip_mcast_fixup_header(u32 dst_mcast_mask, u32 dst_mcast_offset, u32 *addr, u8 *packet0)
Definition: rewrite.h:289
void( serialize_function_t)(serialize_main_t *m, va_list *va)
Definition: serialize.h:168
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:116