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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 clib_memset operation */
119  ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
120 
121  rw->data_bytes = 0;
122  clib_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 clib_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_fast (rw->data, data, data_bytes);
135  clib_memset (rw->data + data_bytes, 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;
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_one_header (vnet_rewrite_header_t * h0,
156  void *packet0, int most_likely_size)
157 {
158  /* 0xfefe => poisoned adjacency => crash */
159  ASSERT (h0->data_bytes != 0xfefe);
160  if (PREDICT_TRUE (most_likely_size == h0->data_bytes))
161  {
162  clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
163  h0->data, most_likely_size);
164  }
165  else
166  {
167  clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
168  h0->data, h0->data_bytes);
169  }
170 }
171 
172 always_inline void
173 _vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
174  vnet_rewrite_header_t * h1,
175  void *packet0, void *packet1, int most_likely_size)
176 {
177  /* 0xfefe => poisoned adjacency => crash */
178  ASSERT (h0->data_bytes != 0xfefe);
179  ASSERT (h1->data_bytes != 0xfefe);
180  if (PREDICT_TRUE
181  (most_likely_size == h0->data_bytes
182  && most_likely_size == h1->data_bytes))
183  {
184  clib_memcpy_fast ((u8 *) packet0 - most_likely_size,
185  h0->data, most_likely_size);
186  clib_memcpy_fast ((u8 *) packet1 - most_likely_size,
187  h1->data, most_likely_size);
188  }
189  else
190  {
191  clib_memcpy_fast ((u8 *) packet0 - h0->data_bytes,
192  h0->data, h0->data_bytes);
193  clib_memcpy_fast ((u8 *) packet1 - h1->data_bytes,
194  h1->data, h1->data_bytes);
195  }
196 }
197 
198 #define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
199  _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
200  (most_likely_size))
201 
202 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
203  _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
204  (p0), (p1), \
205  (most_likely_size))
206 
207 always_inline void
209  u32 dst_mcast_offset, u32 * addr, u8 * packet0)
210 {
211  if (PREDICT_TRUE (0 != dst_mcast_offset))
212  {
213  /* location to write to in the packet */
214  u8 *p0 = packet0 - dst_mcast_offset;
215  u32 *p1 = (u32 *) p0;
216 
217  *p1 |= (*addr & dst_mcast_mask);
218  }
219 }
220 
221 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
222 /** Deprecated */
224  vnet_link_t packet_type,
226  u32 node_index,
227  void *dst_address,
228  vnet_rewrite_header_t * rw,
229  u32 max_rewrite_bytes);
230 
232  u32 sw_if_index);
233 
234 void vnet_rewrite_init (struct vnet_main_t *vnm,
236  vnet_link_t linkt,
237  u32 this_node,
238  u32 next_node, vnet_rewrite_header_t * rw);
239 
240 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
241  vnet_link_t linkt, vnet_rewrite_header_t * rw);
242 
245  vnet_link_t packet_type,
246  const void *dst_address);
248  u32 sw_if_index, u32 ai);
249 
251 
253 
254 #endif /* included_vnet_rewrite_h */
255 
256 /*
257  * fd.io coding-style-patch-verification: ON
258  *
259  * Local Variables:
260  * eval: (c-set-style "gnu")
261  * End:
262  */
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
u32 flags
Definition: vhost_user.h:141
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:252
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:113
#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
u8 data[128]
Definition: ipsec.api:251
vhost_vring_addr_t addr
Definition: vhost_user.h:147
unsigned char u8
Definition: types.h:56
u8 *() format_function_t(u8 *s, va_list *args)
Definition: format.h:48
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
vl_api_interface_index_t sw_if_index
Definition: gre.api:50
#define always_inline
Definition: clib.h:99
static void vnet_rewrite_clear_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:116
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
format_function_t format_vnet_rewrite
Definition: rewrite.h:250
unsigned short u16
Definition: types.h:57
serialize_function_t serialize_vnet_rewrite
Definition: rewrite.h:252
static void * vnet_rewrite_get_data_internal(vnet_rewrite_header_t *rw, int max_size)
Definition: rewrite.h:145
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:126
#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:208
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