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;
50 * Flags associated with the rewrite/adjacency
52 typedef enum vnet_rewrite_flags_t_
55 * This adjacency/interface has output features configured
57 VNET_REWRITE_HAS_FEATURES = (1 << 0),
58 } __attribute__ ((packed)) vnet_rewrite_flags_t;
61 typedef CLIB_PACKED (struct {
62 /* Interface to mark re-written packets with. */
65 /* Next node to feed after packet rewrite is done. */
68 /* Number of bytes in rewrite data. */
71 /* Max packet size layer 3 (MTU) for output interface.
72 Used for MTU check after packet rewrite. */
73 u16 max_l3_packet_bytes;
75 /* Data-plane flags on the adjacency/rewrite */
76 vnet_rewrite_flags_t flags;
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.
84 /* Rewrite string starting at end and going backwards. */
86 }) vnet_rewrite_header_t;
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
93 STATIC_ASSERT (sizeof (vnet_rewrite_header_t) <= 16,
94 "Rewrite header too big");
97 Helper macro for declaring rewrite string w/ given max-size.
104 // Total adjacency is 64 bytes.
105 vnet_rewrite_declare(64 - 2*sizeof(int)) rw;
108 #define vnet_declare_rewrite(total_bytes) \
110 vnet_rewrite_header_t rewrite_header; \
112 u8 rewrite_data[(total_bytes) - sizeof (vnet_rewrite_header_t)]; \
116 vnet_rewrite_clear_data_internal (vnet_rewrite_header_t * rw, int max_size)
118 /* Sanity check values carefully for this clib_memset operation */
119 ASSERT ((max_size > 0) && (max_size < VLIB_BUFFER_PRE_DATA_SIZE));
122 clib_memset (rw->data, 0xfe, max_size);
126 vnet_rewrite_set_data_internal (vnet_rewrite_header_t * rw,
127 int max_size, void *data, int data_bytes)
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));
133 rw->data_bytes = data_bytes;
134 clib_memcpy_fast (rw->data + max_size - data_bytes, data, data_bytes);
135 clib_memset (rw->data, 0xfe, max_size - data_bytes);
138 #define vnet_rewrite_set_data(rw,data,data_bytes) \
139 vnet_rewrite_set_data_internal (&((rw).rewrite_header), \
140 sizeof ((rw).rewrite_data), \
145 vnet_rewrite_get_data_internal (vnet_rewrite_header_t * rw, int max_size)
147 ASSERT (rw->data_bytes <= max_size);
148 return rw->data + max_size - rw->data_bytes;
151 #define vnet_rewrite_get_data(rw) \
152 vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
155 vnet_rewrite_copy_one (vnet_rewrite_data_t * p0, vnet_rewrite_data_t * rw0,
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);
166 typedef CLIB_PACKED (struct {
174 _vnet_rewrite_one_header (vnet_rewrite_header_t * h0,
175 void *packet0, int max_size, int most_likely_size)
177 vnet_rewrite_data_t *p0 = packet0;
178 vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
181 /* 0xfefe => poisoned adjacency => crash */
182 ASSERT (h0->data_bytes != 0xfefe);
184 if (PREDICT_TRUE (h0->data_bytes == sizeof (eh_copy_t)))
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));
193 * Stop now if the data_bytes field is zero, to avoid the cache
194 * miss consequences of spraying [functionally harmless] junk into
195 * un-prefetched rewrite space.
197 if (PREDICT_FALSE (h0->data_bytes == 0))
202 if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
203 vnet_rewrite_copy_one (p0, rw0, (i)); \
214 (((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
215 / (int) sizeof (rw0[0]);
216 if (PREDICT_FALSE (n_left0 > 0))
217 vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
221 _vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
222 vnet_rewrite_header_t * h1,
224 void *packet1, int max_size, int most_likely_size)
226 vnet_rewrite_data_t *p0 = packet0;
227 vnet_rewrite_data_t *p1 = packet1;
228 vnet_rewrite_data_t *rw0 = (vnet_rewrite_data_t *) (h0->data + max_size);
229 vnet_rewrite_data_t *rw1 = (vnet_rewrite_data_t *) (h1->data + max_size);
230 word n_left0, n_left1;
233 /* 0xfefe => poisoned adjacency => crash */
234 ASSERT (h0->data_bytes != 0xfefe);
235 ASSERT (h1->data_bytes != 0xfefe);
237 /* Arithmetic calculation: bytes0 == bytes1 == 14 */
238 slow_path = h0->data_bytes ^ h1->data_bytes;
239 slow_path += h0->data_bytes ^ sizeof (eh_copy_t);
241 if (PREDICT_TRUE (slow_path == 0))
243 eh_copy_t *s0, *d0, *s1, *d1;
244 s0 = (eh_copy_t *) (h0->data + max_size - sizeof (eh_copy_t));
245 d0 = (eh_copy_t *) (((u8 *) packet0) - sizeof (eh_copy_t));
246 clib_memcpy (d0, s0, sizeof (eh_copy_t));
247 s1 = (eh_copy_t *) (h1->data + max_size - sizeof (eh_copy_t));
248 d1 = (eh_copy_t *) (((u8 *) packet1) - sizeof (eh_copy_t));
249 clib_memcpy (d1, s1, sizeof (eh_copy_t));
254 * Stop now if both rewrite data_bytes fields are zero, to avoid the cache
255 * miss consequences of spraying [functionally harmless] junk into
256 * un-prefetched rewrite space.
258 if (PREDICT_FALSE (h0->data_bytes + h1->data_bytes == 0))
263 if (most_likely_size > ((i)-1)*sizeof (vnet_rewrite_data_t)) \
265 vnet_rewrite_copy_one (p0, rw0, (i)); \
266 vnet_rewrite_copy_one (p1, rw1, (i)); \
278 (((int) h0->data_bytes - most_likely_size) + (sizeof (rw0[0]) - 1))
279 / (int) sizeof (rw0[0]);
281 (((int) h1->data_bytes - most_likely_size) + (sizeof (rw1[0]) - 1))
282 / (int) sizeof (rw1[0]);
284 if (PREDICT_FALSE (n_left0 > 0 || n_left1 > 0))
286 vnet_rewrite_copy_slow_path (p0, rw0, n_left0, most_likely_size);
287 vnet_rewrite_copy_slow_path (p1, rw1, n_left1, most_likely_size);
291 #define vnet_rewrite_one_header(rw0,p0,most_likely_size) \
292 _vnet_rewrite_one_header (&((rw0).rewrite_header), (p0), \
293 sizeof ((rw0).rewrite_data), \
296 #define vnet_rewrite_two_headers(rw0,rw1,p0,p1,most_likely_size) \
297 _vnet_rewrite_two_headers (&((rw0).rewrite_header), &((rw1).rewrite_header), \
299 sizeof ((rw0).rewrite_data), \
303 vnet_ip_mcast_fixup_header (u32 dst_mcast_mask,
304 u32 dst_mcast_offset, u32 * addr, u8 * packet0)
306 if (PREDICT_TRUE (0 != dst_mcast_offset))
308 /* location to write to in the packet */
309 u8 *p0 = packet0 - dst_mcast_offset;
310 u32 *p1 = (u32 *) p0;
312 *p1 |= (*addr & dst_mcast_mask);
316 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
318 void vnet_rewrite_for_sw_interface (struct vnet_main_t *vnm,
319 vnet_link_t packet_type,
323 vnet_rewrite_header_t * rw,
324 u32 max_rewrite_bytes);
326 u32 vnet_tx_node_index_for_sw_interface (struct vnet_main_t *vnm,
329 void vnet_rewrite_init (struct vnet_main_t *vnm,
333 u32 next_node, vnet_rewrite_header_t * rw);
335 void vnet_rewrite_update_mtu (struct vnet_main_t *vnm,
336 vnet_link_t linkt, vnet_rewrite_header_t * rw);
338 u8 *vnet_build_rewrite_for_sw_interface (struct vnet_main_t *vnm,
340 vnet_link_t packet_type,
341 const void *dst_address);
342 void vnet_update_adjacency_for_sw_interface (struct vnet_main_t *vnm,
343 u32 sw_if_index, u32 ai);
345 format_function_t format_vnet_rewrite;
347 serialize_function_t serialize_vnet_rewrite, unserialize_vnet_rewrite;
349 #endif /* included_vnet_rewrite_h */
352 * fd.io coding-style-patch-verification: ON
355 * eval: (c-set-style "gnu")