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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. */
63  u32 sw_if_index;
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  /* The mask to apply to the lower 4 bytes of the IP address before ORing
85  * into the destinaiton MAC address */
86  u32 dst_mcast_mask;
87 
88  /* Rewrite string starting at end and going backwards. */
89  u8 data[0];
90 }) vnet_rewrite_header_t;
91 /* *INDENT-ON* */
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(total_bytes) \
113 struct { \
114  vnet_rewrite_header_t rewrite_header; \
115  \
116  u8 rewrite_data[(total_bytes) - sizeof (vnet_rewrite_header_t)]; \
117 }
118 
119 always_inline void
120 vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
121 {
122  /* Sanity check values carefully for this memset operation */
123  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
124 
125  rw->data_bytes = 0;
126  memset (rw->data, 0xfe, max_size);
127 }
128 
129 always_inline void
130 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
131  int max_size, void *data, int data_bytes)
132 {
133  /* Sanity check values carefully for this memset operation */
134  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
135  ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
136 
137  rw->data_bytes = data_bytes;
138  clib_memcpy (rw->data + max_size - data_bytes, data, data_bytes);
139  memset (rw->data, 0xfe, max_size - data_bytes);
140 }
141 
142 #define vnet_rewrite_set_data(rw,data,data_bytes) \
143  vnet_rewrite_set_data_internal (&((rw).rewrite_header), \
144  sizeof ((rw).rewrite_data), \
145  (data), \
146  (data_bytes))
147 
148 always_inline void *
149 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
150 {
151  ASSERT (rw->data_bytes <= max_size);
152  return rw->data + max_size - rw->data_bytes;
153 }
154 
155 #define vnet_rewrite_get_data(rw) \
156  vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
157 
158 always_inline void
159 vnet_rewrite_copy_one (vnet_rewrite_data_t * p0, vnet_rewrite_data_t * rw0,
160  int i)
161 {
162  p0[-i] = rw0[-i];
163 }
164 
165 void vnet_rewrite_copy_slow_path (vnet_rewrite_data_t * p0,
166  vnet_rewrite_data_t * rw0,
167  word n_left, uword most_likely_size);
168 
169 /* *INDENT-OFF* */
170 typedef CLIB_PACKED (struct {
171  u64 a;
172  u32 b;
173  u16 c;
174 }) eh_copy_t;
175 /* *INDENT-ON* */
176 
177 always_inline void
178 _vnet_rewrite_one_header (vnet_rewrite_header_t * h0,
179  void *packet0, int max_size, int most_likely_size)
180 {
181  vnet_rewrite_data_t *p0 = packet0;
182  vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
183  word n_left0;
184 
185  /* 0xfefe => poisoned adjacency => crash */
186  ASSERT (h0->data_bytes != 0xfefe);
187 
188  if (PREDICT_TRUE (h0->data_bytes == sizeof (eh_copy_t)))
189  {
190  eh_copy_t *s, *d;
191  s = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
192  d = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
193  clib_memcpy (d, s, sizeof (eh_copy_t));
194  return;
195  }
196 
197 
198 #define _(i) \
199  do { \
200  if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
201  vnet_rewrite_copy_one (p0, rw0, (i)); \
202  } while (0)
203 
204  _(4);
205  _(3);
206  _(2);
207  _(1);
208 
209 #undef _
210 
211  n_left0 = (int)
212  (((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
213  / (int) sizeof (rw0[0]);
214  if (PREDICT_FALSE (n_left0 > 0))
215  vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
216 }
217 
218 always_inline void
219 _vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
220  vnet_rewrite_header_t * h1,
221  void *packet0,
222  void *packet1, int max_size, int most_likely_size)
223 {
224  vnet_rewrite_data_t *p0 = packet0;
225  vnet_rewrite_data_t *p1 = packet1;
226  vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
227  vnet_rewrite_data_t *rw1 = (vnet_rewrite_data_t *) (h1->data + max_size);
228  word n_left0, n_left1;
229  int slow_path;
230 
231  /* 0xfefe => poisoned adjacency => crash */
232  ASSERT (h0->data_bytes != 0xfefe);
233  ASSERT (h1->data_bytes != 0xfefe);
234 
235  /* Arithmetic calculation: bytes0 == bytes1 == 14 */
236  slow_path = h0->data_bytes ^ h1->data_bytes;
237  slow_path += h0->data_bytes ^ sizeof (eh_copy_t);
238 
239  if (PREDICT_TRUE (slow_path == 0))
240  {
241  eh_copy_t *s0, *d0, *s1, *d1;
242  s0 = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
243  d0 = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
244  clib_memcpy (d0, s0, sizeof (eh_copy_t));
245  s1 = (eh_copy_t *) (h1->data + max_size - sizeof (eh_copy_t));
246  d1 = (eh_copy_t *) (((u8 *) packet1) - sizeof (eh_copy_t));
247  clib_memcpy (d1, s1, sizeof (eh_copy_t));
248  return;
249  }
250 
251 #define _(i) \
252  do { \
253  if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
254  { \
255  vnet_rewrite_copy_one (p0, rw0, (i)); \
256  vnet_rewrite_copy_one (p1, rw1, (i)); \
257  } \
258  } while (0)
259 
260  _(4);
261  _(3);
262  _(2);
263  _(1);
264 
265 #undef _
266 
267  n_left0 = (int)
268  (((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
269  / (int) sizeof (rw0[0]);
270  n_left1 = (int)
271  (((int) h1->data_bytes - most_likely_size) + (sizeof (rw1[0]) - 1))
272  / (int) sizeof (rw1[0]);
273 
274  if (PREDICT_FALSE (n_left0 > 0 || n_left1 > 0))
275  {
276  vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
277  vnet_rewrite_copy_slow_path (p1, rw1, n_left1, most_likely_size);
278  }
279 }
280 
281 #define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
282  _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
283  sizeof ((rw0).rewrite_data), \
284  (most_likely_size))
285 
286 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
287  _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
288  (p0), (p1), \
289  sizeof ((rw0).rewrite_data), \
290  (most_likely_size))
291 
292 always_inline void
293 _vnet_fixup_one_header (vnet_rewrite_header_t * h0,
294  u8 * addr, u32 addr_len, u8 * packet0)
295 {
296  if (PREDICT_TRUE (h0->dst_mcast_mask))
297  {
298  /* location to write to in the packet */
299  u8 *p0 = packet0 - h0->dst_mcast_offset;
300  u32 *p1 = (u32 *) p0;
301  /* location to copy from in the L3 dest address */
302  u32 *a0 = (u32 *) (addr + addr_len - sizeof (h0->dst_mcast_mask));
303 
304  *p1 |= (*a0 & h0->dst_mcast_mask);
305  }
306 }
307 
308 #define vnet_fixup_one_header(rw0,addr,p0) \
309  _vnet_fixup_one_header (&((rw0).rewrite_header), \
310  (u8*)(addr), sizeof((*addr)), \
311  (u8*)(p0))
312 
313 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
314 /** Deprecated */
316  vnet_link_t packet_type,
317  u32 sw_if_index,
318  u32 node_index,
319  void *dst_address,
320  vnet_rewrite_header_t * rw,
321  u32 max_rewrite_bytes);
322 
324  u32 sw_if_index);
325 
326 void vnet_rewrite_init (struct vnet_main_t *vnm,
327  u32 sw_if_index,
328  u32 this_node,
329  u32 next_node, vnet_rewrite_header_t * rw);
330 
331 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
332  vnet_rewrite_header_t * rw);
333 
335  u32 sw_if_index,
336  vnet_link_t packet_type,
337  const void *dst_address);
339  u32 sw_if_index, u32 ai);
340 
342 
344 
345 #endif /* included_vnet_rewrite_h */
346 
347 /*
348  * fd.io coding-style-patch-verification: ON
349  *
350  * Local Variables:
351  * eval: (c-set-style "gnu")
352  * End:
353  */
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:210
void vnet_update_adjacency_for_sw_interface(struct vnet_main_t *vnm, u32 sw_if_index, u32 ai)
Definition: rewrite.c:225
a
Definition: bitmap.h:516
serialize_function_t unserialize_vnet_rewrite
Definition: rewrite.h:343
#define PREDICT_TRUE(x)
Definition: clib.h:106
uword vnet_rewrite_data_t
Definition: rewrite.h:47
#define VLIB_BUFFER_PRE_DATA_SIZE
Definition: buffer.h:52
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;u32 dst_mcast_mask;u8 data[0];}) vnet_rewrite_header_t
void vnet_rewrite_init(struct vnet_main_t *vnm, u32 sw_if_index, u32 this_node, u32 next_node, vnet_rewrite_header_t *rw)
Definition: rewrite.c:104
int i
u8 *( format_function_t)(u8 *s, va_list *args)
Definition: format.h:48
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:36
#define always_inline
Definition: clib.h:92
static void vnet_rewrite_clear_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:120
static void vnet_rewrite_copy_one(vnet_rewrite_data_t *p0, vnet_rewrite_data_t *rw0, int i)
Definition: rewrite.h:159
unsigned long u64
Definition: types.h:89
format_function_t format_vnet_rewrite
Definition: rewrite.h:341
serialize_function_t serialize_vnet_rewrite
Definition: rewrite.h:343
static void * vnet_rewrite_get_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:149
#define PREDICT_FALSE(x)
Definition: clib.h:105
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
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:130
#define clib_memcpy(a, b, c)
Definition: string.h:75
#define ASSERT(truth)
unsigned int u32
Definition: types.h:88
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:122
u64 uword
Definition: types.h:112
unsigned short u16
Definition: types.h:57
i64 word
Definition: types.h:111
void( serialize_function_t)(serialize_main_t *m, va_list *va)
Definition: serialize.h:168
unsigned char u8
Definition: types.h:56
enum vnet_rewrite_flags_t_ vnet_rewrite_flags_t
Flags associated with the rewrite/adjacency.
vhost_vring_addr_t addr
Definition: vhost-user.h:83
vnet_rewrite_flags_t_
Flags associated with the rewrite/adjacency.
Definition: rewrite.h:52
u32 flags
Definition: vhost-user.h:77
This adjacency/interface has output features configured.
Definition: rewrite.h:57
void vnet_rewrite_update_mtu(struct vnet_main_t *vnm, vnet_rewrite_header_t *rw)
Definition: rewrite.c:115