2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 #include "dynamic-string.h"
21 #include "netdev-dpdk.h"
22 #include "dp-packet.h"
26 dp_packet_init__(struct dp_packet *b, size_t allocated, enum dp_packet_source source)
28 b->allocated = allocated;
32 b->l2_5_ofs = b->l3_ofs = b->l4_ofs = UINT16_MAX;
33 b->md = PKT_METADATA_INITIALIZER(0);
34 list_poison(&b->list_node);
38 dp_packet_use__(struct dp_packet *b, void *base, size_t allocated,
39 enum dp_packet_source source)
41 dp_packet_set_base(b, base);
42 dp_packet_set_data(b, base);
43 dp_packet_set_size(b, 0);
45 dp_packet_init__(b, allocated, source);
48 /* Initializes 'b' as an empty dp_packet that contains the 'allocated' bytes of
49 * memory starting at 'base'. 'base' should be the first byte of a region
50 * obtained from malloc(). It will be freed (with free()) if 'b' is resized or
53 dp_packet_use(struct dp_packet *b, void *base, size_t allocated)
55 dp_packet_use__(b, base, allocated, DPBUF_MALLOC);
58 /* Initializes 'b' as an empty dp_packet that contains the 'allocated' bytes of
59 * memory starting at 'base'. 'base' should point to a buffer on the stack.
60 * (Nothing actually relies on 'base' being allocated on the stack. It could
61 * be static or malloc()'d memory. But stack space is the most common use
64 * 'base' should be appropriately aligned. Using an array of uint32_t or
65 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
66 * for 32- or 64-bit data.
68 * An dp_packet operation that requires reallocating data will copy the provided
69 * buffer into a malloc()'d buffer. Thus, it is wise to call dp_packet_uninit()
70 * on an dp_packet initialized by this function, so that if it expanded into the
71 * heap, that memory is freed. */
73 dp_packet_use_stub(struct dp_packet *b, void *base, size_t allocated)
75 dp_packet_use__(b, base, allocated, DPBUF_STUB);
78 /* Initializes 'b' as an dp_packet whose data starts at 'data' and continues for
79 * 'size' bytes. This is appropriate for an dp_packet that will be used to
80 * inspect existing data, without moving it around or reallocating it, and
81 * generally without modifying it at all.
83 * An dp_packet operation that requires reallocating data will assert-fail if this
84 * function was used to initialize it. */
86 dp_packet_use_const(struct dp_packet *b, const void *data, size_t size)
88 dp_packet_use__(b, CONST_CAST(void *, data), size, DPBUF_STACK);
89 dp_packet_set_size(b, size);
92 /* Initializes 'b' as an empty dp_packet that contains the 'allocated' bytes of
93 * memory starting at 'base'. DPDK allocated dp_packet and *data is allocated
94 * from one continous memory region, so in memory data start right after
95 * dp_packet. Therefore there is special method to free this type of
96 * buffer. dp_packet base, data and size are initialized by dpdk rcv() so no
97 * need to initialize those fields. */
99 dp_packet_init_dpdk(struct dp_packet *b, size_t allocated)
101 dp_packet_init__(b, allocated, DPBUF_DPDK);
104 /* Initializes 'b' as an empty dp_packet with an initial capacity of 'size'
107 dp_packet_init(struct dp_packet *b, size_t size)
109 dp_packet_use(b, size ? xmalloc(size) : NULL, size);
112 /* Frees memory that 'b' points to. */
114 dp_packet_uninit(struct dp_packet *b)
117 if (b->source == DPBUF_MALLOC) {
118 free(dp_packet_base(b));
119 } else if (b->source == DPBUF_DPDK) {
121 /* If this dp_packet was allocated by DPDK it must have been
122 * created as a dp_packet */
123 free_dpdk_buf((struct dp_packet*) b);
129 /* Creates and returns a new dp_packet with an initial capacity of 'size'
132 dp_packet_new(size_t size)
134 struct dp_packet *b = xmalloc(sizeof *b);
135 dp_packet_init(b, size);
139 /* Creates and returns a new dp_packet with an initial capacity of 'size +
140 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
142 dp_packet_new_with_headroom(size_t size, size_t headroom)
144 struct dp_packet *b = dp_packet_new(size + headroom);
145 dp_packet_reserve(b, headroom);
149 /* Creates and returns a new dp_packet that initially contains a copy of the
150 * 'dp_packet_size(buffer)' bytes of data starting at 'buffer->data' with no headroom or
153 dp_packet_clone(const struct dp_packet *buffer)
155 return dp_packet_clone_with_headroom(buffer, 0);
158 /* Creates and returns a new dp_packet whose data are copied from 'buffer'. The
159 * returned dp_packet will additionally have 'headroom' bytes of headroom. */
161 dp_packet_clone_with_headroom(const struct dp_packet *buffer, size_t headroom)
163 struct dp_packet *new_buffer;
165 new_buffer = dp_packet_clone_data_with_headroom(dp_packet_data(buffer),
166 dp_packet_size(buffer),
170 = (char *)dp_packet_data(new_buffer) - (char *)dp_packet_data(buffer);
172 new_buffer->frame = (char *) buffer->frame + data_delta;
174 new_buffer->l2_pad_size = buffer->l2_pad_size;
175 new_buffer->l2_5_ofs = buffer->l2_5_ofs;
176 new_buffer->l3_ofs = buffer->l3_ofs;
177 new_buffer->l4_ofs = buffer->l4_ofs;
178 new_buffer->md = buffer->md;
183 /* Creates and returns a new dp_packet that initially contains a copy of the
184 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
186 dp_packet_clone_data(const void *data, size_t size)
188 return dp_packet_clone_data_with_headroom(data, size, 0);
191 /* Creates and returns a new dp_packet that initially contains 'headroom' bytes of
192 * headroom followed by a copy of the 'size' bytes of data starting at
195 dp_packet_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
197 struct dp_packet *b = dp_packet_new_with_headroom(size, headroom);
198 dp_packet_put(b, data, size);
203 dp_packet_copy__(struct dp_packet *b, uint8_t *new_base,
204 size_t new_headroom, size_t new_tailroom)
206 const uint8_t *old_base = dp_packet_base(b);
207 size_t old_headroom = dp_packet_headroom(b);
208 size_t old_tailroom = dp_packet_tailroom(b);
209 size_t copy_headroom = MIN(old_headroom, new_headroom);
210 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
212 memcpy(&new_base[new_headroom - copy_headroom],
213 &old_base[old_headroom - copy_headroom],
214 copy_headroom + dp_packet_size(b) + copy_tailroom);
217 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
218 * bytes of headroom and tailroom, respectively. */
220 dp_packet_resize__(struct dp_packet *b, size_t new_headroom, size_t new_tailroom)
222 void *new_base, *new_data;
223 size_t new_allocated;
225 new_allocated = new_headroom + dp_packet_size(b) + new_tailroom;
232 if (new_headroom == dp_packet_headroom(b)) {
233 new_base = xrealloc(dp_packet_base(b), new_allocated);
235 new_base = xmalloc(new_allocated);
236 dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
237 free(dp_packet_base(b));
245 b->source = DPBUF_MALLOC;
246 new_base = xmalloc(new_allocated);
247 dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
254 b->allocated = new_allocated;
255 dp_packet_set_base(b, new_base);
257 new_data = (char *) new_base + new_headroom;
258 if (dp_packet_data(b) != new_data) {
260 uintptr_t data_delta = (char *) new_data - (char *) dp_packet_data(b);
262 b->frame = (char *) b->frame + data_delta;
264 dp_packet_set_data(b, new_data);
268 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
269 * reallocating and copying its data if necessary. Its headroom, if any, is
272 dp_packet_prealloc_tailroom(struct dp_packet *b, size_t size)
274 if (size > dp_packet_tailroom(b)) {
275 dp_packet_resize__(b, dp_packet_headroom(b), MAX(size, 64));
279 /* Ensures that 'b' has room for at least 'size' bytes at its head,
280 * reallocating and copying its data if necessary. Its tailroom, if any, is
283 dp_packet_prealloc_headroom(struct dp_packet *b, size_t size)
285 if (size > dp_packet_headroom(b)) {
286 dp_packet_resize__(b, MAX(size, 64), dp_packet_tailroom(b));
290 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
291 * For example, a 'delta' of 1 would cause each byte of data to move one byte
292 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
293 * byte to move one byte backward (from 'p' to 'p-1'). */
295 dp_packet_shift(struct dp_packet *b, int delta)
297 ovs_assert(delta > 0 ? delta <= dp_packet_tailroom(b)
298 : delta < 0 ? -delta <= dp_packet_headroom(b)
302 char *dst = (char *) dp_packet_data(b) + delta;
303 memmove(dst, dp_packet_data(b), dp_packet_size(b));
304 dp_packet_set_data(b, dst);
308 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
309 * copying its data if necessary. Returns a pointer to the first byte of the
310 * new data, which is left uninitialized. */
312 dp_packet_put_uninit(struct dp_packet *b, size_t size)
315 dp_packet_prealloc_tailroom(b, size);
316 p = dp_packet_tail(b);
317 dp_packet_set_size(b, dp_packet_size(b) + size);
321 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
322 * reallocated and copied if necessary. Returns a pointer to the first byte of
323 * the data's location in the dp_packet. */
325 dp_packet_put_zeros(struct dp_packet *b, size_t size)
327 void *dst = dp_packet_put_uninit(b, size);
328 memset(dst, 0, size);
332 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
333 * is reallocated and copied if necessary. Returns a pointer to the first
334 * byte of the data's location in the dp_packet. */
336 dp_packet_put(struct dp_packet *b, const void *p, size_t size)
338 void *dst = dp_packet_put_uninit(b, size);
339 memcpy(dst, p, size);
343 /* Parses as many pairs of hex digits as possible (possibly separated by
344 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
345 * Returns the first character of 's' that is not the first of a pair of hex
346 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
349 dp_packet_put_hex(struct dp_packet *b, const char *s, size_t *n)
351 size_t initial_size = dp_packet_size(b);
356 s += strspn(s, " \t\r\n");
357 byte = hexits_value(s, 2, &ok);
360 *n = dp_packet_size(b) - initial_size;
362 return CONST_CAST(char *, s);
365 dp_packet_put(b, &byte, 1);
370 /* Reserves 'size' bytes of headroom so that they can be later allocated with
371 * dp_packet_push_uninit() without reallocating the dp_packet. */
373 dp_packet_reserve(struct dp_packet *b, size_t size)
375 ovs_assert(!dp_packet_size(b));
376 dp_packet_prealloc_tailroom(b, size);
377 dp_packet_set_data(b, (char*)dp_packet_data(b) + size);
380 /* Reserves 'headroom' bytes at the head and 'tailroom' at the end so that
381 * they can be later allocated with dp_packet_push_uninit() or
382 * dp_packet_put_uninit() without reallocating the dp_packet. */
384 dp_packet_reserve_with_tailroom(struct dp_packet *b, size_t headroom,
387 ovs_assert(!dp_packet_size(b));
388 dp_packet_prealloc_tailroom(b, headroom + tailroom);
389 dp_packet_set_data(b, (char*)dp_packet_data(b) + headroom);
392 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
393 * data if necessary. Returns a pointer to the first byte of the data's
394 * location in the dp_packet. The new data is left uninitialized. */
396 dp_packet_push_uninit(struct dp_packet *b, size_t size)
398 dp_packet_prealloc_headroom(b, size);
399 dp_packet_set_data(b, (char*)dp_packet_data(b) - size);
400 dp_packet_set_size(b, dp_packet_size(b) + size);
401 return dp_packet_data(b);
404 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
405 * copying its data if necessary. Returns a pointer to the first byte of the
406 * data's location in the dp_packet. */
408 dp_packet_push_zeros(struct dp_packet *b, size_t size)
410 void *dst = dp_packet_push_uninit(b, size);
411 memset(dst, 0, size);
415 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
416 * and copying its data if necessary. Returns a pointer to the first byte of
417 * the data's location in the dp_packet. */
419 dp_packet_push(struct dp_packet *b, const void *p, size_t size)
421 void *dst = dp_packet_push_uninit(b, size);
422 memcpy(dst, p, size);
426 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
427 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
428 * dp_packet_new(), then it should still be freed with, e.g., dp_packet_delete().) */
430 dp_packet_steal_data(struct dp_packet *b)
433 ovs_assert(b->source != DPBUF_DPDK);
435 if (b->source == DPBUF_MALLOC && dp_packet_data(b) == dp_packet_base(b)) {
436 p = dp_packet_data(b);
438 p = xmemdup(dp_packet_data(b), dp_packet_size(b));
439 if (b->source == DPBUF_MALLOC) {
440 free(dp_packet_base(b));
443 dp_packet_set_base(b, NULL);
444 dp_packet_set_data(b, NULL);
448 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
449 * to 'maxbytes' from the start of the buffer. */
451 dp_packet_to_string(const struct dp_packet *b, size_t maxbytes)
456 ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
457 dp_packet_size(b), b->allocated,
458 dp_packet_headroom(b), dp_packet_tailroom(b));
459 ds_put_hex_dump(&s, dp_packet_data(b), MIN(dp_packet_size(b), maxbytes), 0, false);
463 /* Removes each of the "struct dp_packet"s on 'list' from the list and frees
466 dp_packet_list_delete(struct ovs_list *list)
468 struct dp_packet *b, *next;
470 LIST_FOR_EACH_SAFE (b, next, list_node, list) {
471 list_remove(&b->list_node);
477 dp_packet_adjust_layer_offset(uint16_t *offset, int increment)
479 if (*offset != UINT16_MAX) {
480 *offset += increment;
484 /* Adjust the size of the l2_5 portion of the dp_packet, updating the l2
485 * pointer and the layer offsets. The caller is responsible for
486 * modifying the contents. */
488 dp_packet_resize_l2_5(struct dp_packet *b, int increment)
490 if (increment >= 0) {
491 dp_packet_push_uninit(b, increment);
493 dp_packet_pull(b, -increment);
496 b->frame = dp_packet_data(b);
497 /* Adjust layer offsets after l2_5. */
498 dp_packet_adjust_layer_offset(&b->l3_ofs, increment);
499 dp_packet_adjust_layer_offset(&b->l4_ofs, increment);
504 /* Adjust the size of the l2 portion of the dp_packet, updating the l2
505 * pointer and the layer offsets. The caller is responsible for
506 * modifying the contents. */
508 dp_packet_resize_l2(struct dp_packet *b, int increment)
510 dp_packet_resize_l2_5(b, increment);
511 dp_packet_adjust_layer_offset(&b->l2_5_ofs, increment);