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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
16 * rewrite.h: packet rewrite
18 * Copyright (c) 2008 Eliot Dresselhaus
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:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
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.
40 #ifndef included_vnet_rewrite_h
41 #define included_vnet_rewrite_h
43 #include <vlib/vlib.h>
44 #include <vnet/l3_types.h>
46 /* Consider using vector types for speed? */
47 typedef uword vnet_rewrite_data_t;
49 typedef CLIB_PACKED (struct {
50 /* Interface to mark re-written packets with. */
53 /* Packet processing node where rewrite happens. */
56 /* Next node to feed after packet rewrite is done. */
59 /* Number of bytes in rewrite data. */
62 /* Max packet size layer 3 (MTU) for output interface.
63 Used for MTU check after packet rewrite. */
64 u16 max_l3_packet_bytes;
66 /* Rewrite string starting at end and going backwards. */
68 }) vnet_rewrite_header_t;
71 Helper macro for declaring rewrite string w/ given max-size.
78 // Total adjacency is 64 bytes.
79 vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
82 #define vnet_declare_rewrite(total_bytes) \
84 vnet_rewrite_header_t rewrite_header; \
86 u8 rewrite_data[(total_bytes) - sizeof (vnet_rewrite_header_t)]; \
90 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
95 /* Sanity check values carefully for this memset operation*/
96 ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
97 ASSERT ((data_bytes >= 0) && (data_bytes < max_size));
99 rw->data_bytes = data_bytes;
100 memcpy (rw->data + max_size - data_bytes, data, data_bytes);
101 memset (rw->data, 0xfe, max_size - data_bytes);
104 #define vnet_rewrite_set_data(rw,data,data_bytes) \
105 vnet_rewrite_set_data_internal (&((rw).rewrite_header), \
106 sizeof ((rw).rewrite_data), \
111 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
113 ASSERT (rw->data_bytes <= max_size);
114 return rw->data + max_size - rw->data_bytes;
117 #define vnet_rewrite_get_data(rw) \
118 vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
121 vnet_rewrite_copy_one (vnet_rewrite_data_t * p0, vnet_rewrite_data_t * rw0, int i)
126 void vnet_rewrite_copy_slow_path (vnet_rewrite_data_t * p0,
127 vnet_rewrite_data_t * rw0,
129 uword most_likely_size);
131 typedef CLIB_PACKED (struct {
138 _vnet_rewrite_one_header (vnet_rewrite_header_t * h0,
141 int most_likely_size)
143 vnet_rewrite_data_t * p0 = packet0;
144 vnet_rewrite_data_t * rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
147 /* 0xfefe => poisoned adjacency => crash */
148 ASSERT (h0->data_bytes != 0xfefe);
150 if (PREDICT_TRUE (h0->data_bytes == sizeof (eh_copy_t)))
153 s = (eh_copy_t *)(h0->data + max_size - sizeof (eh_copy_t));
154 d = (eh_copy_t *)(((u8 *)packet0) - sizeof (eh_copy_t));
155 __builtin_memcpy (d, s, sizeof (eh_copy_t));
162 if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
163 vnet_rewrite_copy_one (p0, rw0, (i)); \
174 (((int) h0->data_bytes - most_likely_size) + (sizeof(rw0[0])-1))
175 / (int) sizeof (rw0[0]);
176 if (PREDICT_FALSE (n_left0 > 0))
177 vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
181 _vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
182 vnet_rewrite_header_t * h1,
186 int most_likely_size)
188 vnet_rewrite_data_t * p0 = packet0;
189 vnet_rewrite_data_t * p1 = packet1;
190 vnet_rewrite_data_t * rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
191 vnet_rewrite_data_t * rw1 = (vnet_rewrite_data_t *) (h1->data + max_size);
192 word n_left0, n_left1;
195 /* 0xfefe => poisoned adjacency => crash */
196 ASSERT (h0->data_bytes != 0xfefe);
197 ASSERT (h1->data_bytes != 0xfefe);
199 /* Arithmetic calculation: bytes0 == bytes1 == 14 */
200 slow_path = h0->data_bytes ^ h1->data_bytes;
201 slow_path += h0->data_bytes ^ sizeof (eh_copy_t);
203 if (PREDICT_TRUE (slow_path == 0))
205 eh_copy_t * s0, * d0, * s1, * d1;
206 s0 = (eh_copy_t *)(h0->data + max_size - sizeof (eh_copy_t));
207 d0 = (eh_copy_t *)(((u8 *)packet0) - sizeof (eh_copy_t));
208 __builtin_memcpy (d0, s0, sizeof (eh_copy_t));
209 s1 = (eh_copy_t *)(h1->data + max_size - sizeof (eh_copy_t));
210 d1 = (eh_copy_t *)(((u8 *)packet1) - sizeof (eh_copy_t));
211 __builtin_memcpy (d1, s1, sizeof (eh_copy_t));
217 if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
219 vnet_rewrite_copy_one (p0, rw0, (i)); \
220 vnet_rewrite_copy_one (p1, rw1, (i)); \
232 (((int) h0->data_bytes - most_likely_size) + (sizeof(rw0[0])-1))
233 / (int) sizeof (rw0[0]);
235 (((int) h1->data_bytes - most_likely_size) + (sizeof(rw1[0])-1))
236 / (int) sizeof (rw1[0]);
238 if (PREDICT_FALSE (n_left0 > 0 || n_left1 > 0))
240 vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
241 vnet_rewrite_copy_slow_path (p1, rw1, n_left1, most_likely_size);
245 #define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
246 _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
247 sizeof ((rw0).rewrite_data), \
250 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
251 _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
253 sizeof ((rw0).rewrite_data), \
256 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
257 void vnet_rewrite_for_sw_interface (struct vnet_main_t * vnm,
258 vnet_l3_packet_type_t packet_type,
262 vnet_rewrite_header_t * rw,
263 u32 max_rewrite_bytes);
265 void vnet_rewrite_for_tunnel (struct vnet_main_t * vnm,
267 u32 rewrite_node_index,
268 u32 post_rewrite_node_index,
269 vnet_rewrite_header_t * rw,
273 /* Parser for unformat header & rewrite string. */
274 unformat_function_t unformat_vnet_rewrite;
276 format_function_t format_vnet_rewrite;
277 format_function_t format_vnet_rewrite_header;
279 serialize_function_t serialize_vnet_rewrite, unserialize_vnet_rewrite;
281 #endif /* included_vnet_rewrite_h */