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 /* Returns a pointer that may be passed to free() to accomplish the same thing
125 * as ofpbuf_uninit(b). The return value is a null pointer if ofpbuf_uninit()
126 * would not free any memory. */
128 ofpbuf_get_uninit_pointer(struct ofpbuf *b)
130 return b && b->source == OFPBUF_MALLOC ? b->base : NULL;
133 /* Frees memory that 'b' points to and allocates a new ofpbuf */
135 ofpbuf_reinit(struct ofpbuf *b, size_t size)
138 ofpbuf_init(b, size);
141 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
144 ofpbuf_new(size_t size)
146 struct ofpbuf *b = xmalloc(sizeof *b);
147 ofpbuf_init(b, size);
151 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
152 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
154 ofpbuf_new_with_headroom(size_t size, size_t headroom)
156 struct ofpbuf *b = ofpbuf_new(size + headroom);
157 ofpbuf_reserve(b, headroom);
161 /* Creates and returns a new ofpbuf that initially contains a copy of the
162 * 'buffer->size' bytes of data starting at 'buffer->data' with no headroom or
165 ofpbuf_clone(const struct ofpbuf *buffer)
167 return ofpbuf_clone_with_headroom(buffer, 0);
170 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
171 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
173 ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom)
175 struct ofpbuf *new_buffer;
176 uintptr_t data_delta;
178 new_buffer = ofpbuf_clone_data_with_headroom(buffer->data, buffer->size,
180 data_delta = (char *) new_buffer->data - (char *) buffer->data;
183 new_buffer->l2 = (char *) buffer->l2 + data_delta;
186 new_buffer->l2_5 = (char *) buffer->l2_5 + data_delta;
189 new_buffer->l3 = (char *) buffer->l3 + data_delta;
192 new_buffer->l4 = (char *) buffer->l4 + data_delta;
195 new_buffer->l7 = (char *) buffer->l7 + data_delta;
201 /* Creates and returns a new ofpbuf that initially contains a copy of the
202 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
204 ofpbuf_clone_data(const void *data, size_t size)
206 return ofpbuf_clone_data_with_headroom(data, size, 0);
209 /* Creates and returns a new ofpbuf that initially contains 'headroom' bytes of
210 * headroom followed by a copy of the 'size' bytes of data starting at
213 ofpbuf_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
215 struct ofpbuf *b = ofpbuf_new_with_headroom(size, headroom);
216 ofpbuf_put(b, data, size);
220 /* Frees memory that 'b' points to, as well as 'b' itself. */
222 ofpbuf_delete(struct ofpbuf *b)
230 /* Returns the number of bytes of headroom in 'b', that is, the number of bytes
231 * of unused space in ofpbuf 'b' before the data that is in use. (Most
232 * commonly, the data in a ofpbuf is at its beginning, and thus the ofpbuf's
235 ofpbuf_headroom(const struct ofpbuf *b)
237 return (char*)b->data - (char*)b->base;
240 /* Returns the number of bytes that may be appended to the tail end of ofpbuf
241 * 'b' before the ofpbuf must be reallocated. */
243 ofpbuf_tailroom(const struct ofpbuf *b)
245 return (char*)ofpbuf_end(b) - (char*)ofpbuf_tail(b);
249 ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
250 size_t new_headroom, size_t new_tailroom)
252 const uint8_t *old_base = b->base;
253 size_t old_headroom = ofpbuf_headroom(b);
254 size_t old_tailroom = ofpbuf_tailroom(b);
255 size_t copy_headroom = MIN(old_headroom, new_headroom);
256 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
258 memcpy(&new_base[new_headroom - copy_headroom],
259 &old_base[old_headroom - copy_headroom],
260 copy_headroom + b->size + copy_tailroom);
263 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
264 * bytes of headroom and tailroom, respectively. */
266 ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
268 void *new_base, *new_data;
269 size_t new_allocated;
271 new_allocated = new_headroom + b->size + new_tailroom;
278 if (new_headroom == ofpbuf_headroom(b)) {
279 new_base = xrealloc(b->base, new_allocated);
281 new_base = xmalloc(new_allocated);
282 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
291 b->source = OFPBUF_MALLOC;
292 new_base = xmalloc(new_allocated);
293 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
300 b->allocated = new_allocated;
303 new_data = (char *) new_base + new_headroom;
304 if (b->data != new_data) {
305 uintptr_t data_delta = (char *) new_data - (char *) b->data;
308 b->l2 = (char *) b->l2 + data_delta;
311 b->l2_5 = (char *) b->l2_5 + data_delta;
314 b->l3 = (char *) b->l3 + data_delta;
317 b->l4 = (char *) b->l4 + data_delta;
320 b->l7 = (char *) b->l7 + data_delta;
325 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
326 * reallocating and copying its data if necessary. Its headroom, if any, is
329 ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size)
331 if (size > ofpbuf_tailroom(b)) {
332 ofpbuf_resize__(b, ofpbuf_headroom(b), MAX(size, 64));
336 /* Ensures that 'b' has room for at least 'size' bytes at its head,
337 * reallocating and copying its data if necessary. Its tailroom, if any, is
340 ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
342 if (size > ofpbuf_headroom(b)) {
343 ofpbuf_resize__(b, MAX(size, 64), ofpbuf_tailroom(b));
347 /* Trims the size of 'b' to fit its actual content, reducing its tailroom to
348 * 0. Its headroom, if any, is preserved.
350 * Buffers not obtained from malloc() are not resized, since that wouldn't save
353 ofpbuf_trim(struct ofpbuf *b)
355 ovs_assert(b->source != OFPBUF_DPDK);
357 if (b->source == OFPBUF_MALLOC
358 && (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
359 ofpbuf_resize__(b, 0, 0);
363 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
366 ofpbuf_padto(struct ofpbuf *b, size_t length)
368 if (b->size < length) {
369 ofpbuf_put_zeros(b, length - b->size);
373 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
374 * For example, a 'delta' of 1 would cause each byte of data to move one byte
375 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
376 * byte to move one byte backward (from 'p' to 'p-1'). */
378 ofpbuf_shift(struct ofpbuf *b, int delta)
380 ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
381 : delta < 0 ? -delta <= ofpbuf_headroom(b)
385 char *dst = (char *) b->data + delta;
386 memmove(dst, b->data, b->size);
391 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
392 * copying its data if necessary. Returns a pointer to the first byte of the
393 * new data, which is left uninitialized. */
395 ofpbuf_put_uninit(struct ofpbuf *b, size_t size)
398 ofpbuf_prealloc_tailroom(b, size);
404 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
405 * reallocated and copied if necessary. Returns a pointer to the first byte of
406 * the data's location in the ofpbuf. */
408 ofpbuf_put_zeros(struct ofpbuf *b, size_t size)
410 void *dst = ofpbuf_put_uninit(b, size);
411 memset(dst, 0, size);
415 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
416 * is reallocated and copied if necessary. Returns a pointer to the first
417 * byte of the data's location in the ofpbuf. */
419 ofpbuf_put(struct ofpbuf *b, const void *p, size_t size)
421 void *dst = ofpbuf_put_uninit(b, size);
422 memcpy(dst, p, size);
426 /* Parses as many pairs of hex digits as possible (possibly separated by
427 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
428 * Returns the first character of 's' that is not the first of a pair of hex
429 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
432 ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n)
434 size_t initial_size = b->size;
439 s += strspn(s, " \t\r\n");
440 byte = hexits_value(s, 2, &ok);
443 *n = b->size - initial_size;
445 return CONST_CAST(char *, s);
448 ofpbuf_put(b, &byte, 1);
453 /* Reserves 'size' bytes of headroom so that they can be later allocated with
454 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
456 ofpbuf_reserve(struct ofpbuf *b, size_t size)
458 ovs_assert(!b->size);
459 ofpbuf_prealloc_tailroom(b, size);
460 b->data = (char*)b->data + size;
463 /* Reserves 'size' bytes of headroom so that they can be later allocated with
464 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
466 ofpbuf_reserve_with_tailroom(struct ofpbuf *b, size_t headroom,
469 ovs_assert(!b->size);
470 ofpbuf_prealloc_tailroom(b, headroom + tailroom);
471 b->data = (char*)b->data + headroom;
474 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
475 * data if necessary. Returns a pointer to the first byte of the data's
476 * location in the ofpbuf. The new data is left uninitialized. */
478 ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
480 ofpbuf_prealloc_headroom(b, size);
481 b->data = (char*)b->data - size;
486 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
487 * copying its data if necessary. Returns a pointer to the first byte of the
488 * data's location in the ofpbuf. */
490 ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
492 void *dst = ofpbuf_push_uninit(b, size);
493 memset(dst, 0, size);
497 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
498 * and copying its data if necessary. Returns a pointer to the first byte of
499 * the data's location in the ofpbuf. */
501 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size)
503 void *dst = ofpbuf_push_uninit(b, size);
504 memcpy(dst, p, size);
508 /* If 'b' contains at least 'offset + size' bytes of data, returns a pointer to
509 * byte 'offset'. Otherwise, returns a null pointer. */
511 ofpbuf_at(const struct ofpbuf *b, size_t offset, size_t size)
513 return offset + size <= b->size ? (char *) b->data + offset : NULL;
516 /* Returns a pointer to byte 'offset' in 'b', which must contain at least
517 * 'offset + size' bytes of data. */
519 ofpbuf_at_assert(const struct ofpbuf *b, size_t offset, size_t size)
521 ovs_assert(offset + size <= b->size);
522 return ((char *) b->data) + offset;
525 /* Returns the byte following the last byte of data in use in 'b'. */
527 ofpbuf_tail(const struct ofpbuf *b)
529 return (char *) b->data + b->size;
532 /* Returns the byte following the last byte allocated for use (but not
533 * necessarily in use) by 'b'. */
535 ofpbuf_end(const struct ofpbuf *b)
537 return (char *) b->base + b->allocated;
540 /* Clears any data from 'b'. */
542 ofpbuf_clear(struct ofpbuf *b)
548 /* Removes 'size' bytes from the head end of 'b', which must contain at least
549 * 'size' bytes of data. Returns the first byte of data removed. */
551 ofpbuf_pull(struct ofpbuf *b, size_t size)
553 void *data = b->data;
554 ovs_assert(b->size >= size);
555 b->data = (char*)b->data + size;
560 /* If 'b' has at least 'size' bytes of data, removes that many bytes from the
561 * head end of 'b' and returns the first byte removed. Otherwise, returns a
562 * null pointer without modifying 'b'. */
564 ofpbuf_try_pull(struct ofpbuf *b, size_t size)
566 return b->size >= size ? ofpbuf_pull(b, size) : NULL;
569 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
570 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
571 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
573 ofpbuf_steal_data(struct ofpbuf *b)
576 ovs_assert(b->source != OFPBUF_DPDK);
578 if (b->source == OFPBUF_MALLOC && b->data == b->base) {
581 p = xmemdup(b->data, b->size);
582 if (b->source == OFPBUF_MALLOC) {
586 b->base = b->data = NULL;
590 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
591 * to 'maxbytes' from the start of the buffer. */
593 ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
598 ds_put_format(&s, "size=%"PRIuSIZE", allocated=%"PRIuSIZE", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
599 b->size, b->allocated,
600 ofpbuf_headroom(b), ofpbuf_tailroom(b));
601 ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
605 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
608 ofpbuf_list_delete(struct list *list)
610 struct ofpbuf *b, *next;
612 LIST_FOR_EACH_SAFE (b, next, list_node, list) {
613 list_remove(&b->list_node);