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.
21 #include "dynamic-string.h"
22 #include "netdev-dpdk.h"
26 ofpbuf_use__(struct ofpbuf *b, void *base, size_t allocated,
27 enum ofpbuf_source source)
29 b->base = b->data = base;
30 b->allocated = allocated;
33 b->l2 = b->l2_5 = b->l3 = b->l4 = b->l7 = NULL;
34 list_poison(&b->list_node);
38 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
39 * memory starting at 'base'. 'base' should be the first byte of a region
40 * obtained from malloc(). It will be freed (with free()) if 'b' is resized or
43 ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated)
45 ofpbuf_use__(b, base, allocated, OFPBUF_MALLOC);
48 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
49 * memory starting at 'base'. 'base' should point to a buffer on the stack.
50 * (Nothing actually relies on 'base' being allocated on the stack. It could
51 * be static or malloc()'d memory. But stack space is the most common use
54 * 'base' should be appropriately aligned. Using an array of uint32_t or
55 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
56 * for 32- or 64-bit data.
58 * An ofpbuf operation that requires reallocating data will assert-fail if this
59 * function was used to initialize it. Thus, one need not call ofpbuf_uninit()
60 * on an ofpbuf initialized by this function (though doing so is harmless),
61 * because it is guaranteed that 'b' does not own any heap-allocated memory. */
63 ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
65 ofpbuf_use__(b, base, allocated, OFPBUF_STACK);
68 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
69 * memory starting at 'base'. 'base' should point to a buffer on the stack.
70 * (Nothing actually relies on 'base' being allocated on the stack. It could
71 * be static or malloc()'d memory. But stack space is the most common use
74 * 'base' should be appropriately aligned. Using an array of uint32_t or
75 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
76 * for 32- or 64-bit data.
78 * An ofpbuf operation that requires reallocating data will copy the provided
79 * buffer into a malloc()'d buffer. Thus, it is wise to call ofpbuf_uninit()
80 * on an ofpbuf initialized by this function, so that if it expanded into the
81 * heap, that memory is freed. */
83 ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
85 ofpbuf_use__(b, base, allocated, OFPBUF_STUB);
88 /* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
89 * 'size' bytes. This is appropriate for an ofpbuf that will be used to
90 * inspect existing data, without moving it around or reallocating it, and
91 * generally without modifying it at all.
93 * An ofpbuf operation that requires reallocating data will assert-fail if this
94 * function was used to initialize it. */
96 ofpbuf_use_const(struct ofpbuf *b, const void *data, size_t size)
98 ofpbuf_use__(b, CONST_CAST(void *, data), size, OFPBUF_STACK);
102 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
105 ofpbuf_init(struct ofpbuf *b, size_t size)
107 ofpbuf_use(b, size ? xmalloc(size) : NULL, size);
110 /* Frees memory that 'b' points to. */
112 ofpbuf_uninit(struct ofpbuf *b)
115 if (b->source == OFPBUF_MALLOC) {
118 if (b->source == OFPBUF_DPDK) {
124 /* Frees memory that 'b' points to and allocates a new ofpbuf */
126 ofpbuf_reinit(struct ofpbuf *b, size_t size)
129 ofpbuf_init(b, size);
132 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
135 ofpbuf_new(size_t size)
137 struct ofpbuf *b = xmalloc(sizeof *b);
138 ofpbuf_init(b, size);
142 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
143 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
145 ofpbuf_new_with_headroom(size_t size, size_t headroom)
147 struct ofpbuf *b = ofpbuf_new(size + headroom);
148 ofpbuf_reserve(b, headroom);
152 /* Creates and returns a new ofpbuf that initially contains a copy of the
153 * 'buffer->size' bytes of data starting at 'buffer->data' with no headroom or
156 ofpbuf_clone(const struct ofpbuf *buffer)
158 return ofpbuf_clone_with_headroom(buffer, 0);
161 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
162 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
164 ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom)
166 struct ofpbuf *new_buffer;
167 uintptr_t data_delta;
169 new_buffer = ofpbuf_clone_data_with_headroom(buffer->data, buffer->size,
171 data_delta = (char *) new_buffer->data - (char *) buffer->data;
174 new_buffer->l2 = (char *) buffer->l2 + data_delta;
177 new_buffer->l2_5 = (char *) buffer->l2_5 + data_delta;
180 new_buffer->l3 = (char *) buffer->l3 + data_delta;
183 new_buffer->l4 = (char *) buffer->l4 + data_delta;
186 new_buffer->l7 = (char *) buffer->l7 + data_delta;
192 /* Creates and returns a new ofpbuf that initially contains a copy of the
193 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
195 ofpbuf_clone_data(const void *data, size_t size)
197 return ofpbuf_clone_data_with_headroom(data, size, 0);
200 /* Creates and returns a new ofpbuf that initially contains 'headroom' bytes of
201 * headroom followed by a copy of the 'size' bytes of data starting at
204 ofpbuf_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
206 struct ofpbuf *b = ofpbuf_new_with_headroom(size, headroom);
207 ofpbuf_put(b, data, size);
212 ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
213 size_t new_headroom, size_t new_tailroom)
215 const uint8_t *old_base = b->base;
216 size_t old_headroom = ofpbuf_headroom(b);
217 size_t old_tailroom = ofpbuf_tailroom(b);
218 size_t copy_headroom = MIN(old_headroom, new_headroom);
219 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
221 memcpy(&new_base[new_headroom - copy_headroom],
222 &old_base[old_headroom - copy_headroom],
223 copy_headroom + b->size + copy_tailroom);
226 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
227 * bytes of headroom and tailroom, respectively. */
229 ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
231 void *new_base, *new_data;
232 size_t new_allocated;
234 new_allocated = new_headroom + b->size + new_tailroom;
241 if (new_headroom == ofpbuf_headroom(b)) {
242 new_base = xrealloc(b->base, new_allocated);
244 new_base = xmalloc(new_allocated);
245 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
254 b->source = OFPBUF_MALLOC;
255 new_base = xmalloc(new_allocated);
256 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
263 b->allocated = new_allocated;
266 new_data = (char *) new_base + new_headroom;
267 if (b->data != new_data) {
268 uintptr_t data_delta = (char *) new_data - (char *) b->data;
271 b->l2 = (char *) b->l2 + data_delta;
274 b->l2_5 = (char *) b->l2_5 + data_delta;
277 b->l3 = (char *) b->l3 + data_delta;
280 b->l4 = (char *) b->l4 + data_delta;
283 b->l7 = (char *) b->l7 + data_delta;
288 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
289 * reallocating and copying its data if necessary. Its headroom, if any, is
292 ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size)
294 if (size > ofpbuf_tailroom(b)) {
295 ofpbuf_resize__(b, ofpbuf_headroom(b), MAX(size, 64));
299 /* Ensures that 'b' has room for at least 'size' bytes at its head,
300 * reallocating and copying its data if necessary. Its tailroom, if any, is
303 ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
305 if (size > ofpbuf_headroom(b)) {
306 ofpbuf_resize__(b, MAX(size, 64), ofpbuf_tailroom(b));
310 /* Trims the size of 'b' to fit its actual content, reducing its tailroom to
311 * 0. Its headroom, if any, is preserved.
313 * Buffers not obtained from malloc() are not resized, since that wouldn't save
316 ofpbuf_trim(struct ofpbuf *b)
318 ovs_assert(b->source != OFPBUF_DPDK);
320 if (b->source == OFPBUF_MALLOC
321 && (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
322 ofpbuf_resize__(b, 0, 0);
326 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
329 ofpbuf_padto(struct ofpbuf *b, size_t length)
331 if (b->size < length) {
332 ofpbuf_put_zeros(b, length - b->size);
336 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
337 * For example, a 'delta' of 1 would cause each byte of data to move one byte
338 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
339 * byte to move one byte backward (from 'p' to 'p-1'). */
341 ofpbuf_shift(struct ofpbuf *b, int delta)
343 ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
344 : delta < 0 ? -delta <= ofpbuf_headroom(b)
348 char *dst = (char *) b->data + delta;
349 memmove(dst, b->data, b->size);
354 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
355 * copying its data if necessary. Returns a pointer to the first byte of the
356 * new data, which is left uninitialized. */
358 ofpbuf_put_uninit(struct ofpbuf *b, size_t size)
361 ofpbuf_prealloc_tailroom(b, size);
367 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
368 * reallocated and copied if necessary. Returns a pointer to the first byte of
369 * the data's location in the ofpbuf. */
371 ofpbuf_put_zeros(struct ofpbuf *b, size_t size)
373 void *dst = ofpbuf_put_uninit(b, size);
374 memset(dst, 0, size);
378 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
379 * is reallocated and copied if necessary. Returns a pointer to the first
380 * byte of the data's location in the ofpbuf. */
382 ofpbuf_put(struct ofpbuf *b, const void *p, size_t size)
384 void *dst = ofpbuf_put_uninit(b, size);
385 memcpy(dst, p, size);
389 /* Parses as many pairs of hex digits as possible (possibly separated by
390 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
391 * Returns the first character of 's' that is not the first of a pair of hex
392 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
395 ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n)
397 size_t initial_size = b->size;
402 s += strspn(s, " \t\r\n");
403 byte = hexits_value(s, 2, &ok);
406 *n = b->size - initial_size;
408 return CONST_CAST(char *, s);
411 ofpbuf_put(b, &byte, 1);
416 /* Reserves 'size' bytes of headroom so that they can be later allocated with
417 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
419 ofpbuf_reserve(struct ofpbuf *b, size_t size)
421 ovs_assert(!b->size);
422 ofpbuf_prealloc_tailroom(b, size);
423 b->data = (char*)b->data + size;
426 /* Reserves 'size' bytes of headroom so that they can be later allocated with
427 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
429 ofpbuf_reserve_with_tailroom(struct ofpbuf *b, size_t headroom,
432 ovs_assert(!b->size);
433 ofpbuf_prealloc_tailroom(b, headroom + tailroom);
434 b->data = (char*)b->data + headroom;
437 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
438 * data if necessary. Returns a pointer to the first byte of the data's
439 * location in the ofpbuf. The new data is left uninitialized. */
441 ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
443 ofpbuf_prealloc_headroom(b, size);
444 b->data = (char*)b->data - size;
449 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
450 * copying its data if necessary. Returns a pointer to the first byte of the
451 * data's location in the ofpbuf. */
453 ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
455 void *dst = ofpbuf_push_uninit(b, size);
456 memset(dst, 0, size);
460 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
461 * and copying its data if necessary. Returns a pointer to the first byte of
462 * the data's location in the ofpbuf. */
464 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size)
466 void *dst = ofpbuf_push_uninit(b, size);
467 memcpy(dst, p, size);
471 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
472 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
473 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
475 ofpbuf_steal_data(struct ofpbuf *b)
478 ovs_assert(b->source != OFPBUF_DPDK);
480 if (b->source == OFPBUF_MALLOC && b->data == b->base) {
483 p = xmemdup(b->data, b->size);
484 if (b->source == OFPBUF_MALLOC) {
488 b->base = b->data = NULL;
492 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
493 * to 'maxbytes' from the start of the buffer. */
495 ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
500 ds_put_format(&s, "size=%"PRIuSIZE", allocated=%"PRIuSIZE", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
501 b->size, b->allocated,
502 ofpbuf_headroom(b), ofpbuf_tailroom(b));
503 ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
507 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
510 ofpbuf_list_delete(struct list *list)
512 struct ofpbuf *b, *next;
514 LIST_FOR_EACH_SAFE (b, next, list_node, list) {
515 list_remove(&b->list_node);