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_init__(struct ofpbuf *b, size_t allocated, enum ofpbuf_source source)
28 b->allocated = allocated;
32 list_poison(&b->list_node);
36 ofpbuf_use__(struct ofpbuf *b, void *base, size_t allocated, size_t size,
37 enum ofpbuf_source source)
43 ofpbuf_init__(b, allocated, source);
46 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
47 * memory starting at 'base'. 'base' should be the first byte of a region
48 * obtained from malloc(). It will be freed (with free()) if 'b' is resized or
51 ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated)
53 ofpbuf_use__(b, base, allocated, 0, OFPBUF_MALLOC);
56 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
57 * memory starting at 'base'. 'base' should point to a buffer on the stack.
58 * (Nothing actually relies on 'base' being allocated on the stack. It could
59 * be static or malloc()'d memory. But stack space is the most common use
62 * 'base' should be appropriately aligned. Using an array of uint32_t or
63 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
64 * for 32- or 64-bit data.
66 * An ofpbuf operation that requires reallocating data will assert-fail if this
67 * function was used to initialize it. Thus, one need not call ofpbuf_uninit()
68 * on an ofpbuf initialized by this function (though doing so is harmless),
69 * because it is guaranteed that 'b' does not own any heap-allocated memory. */
71 ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
73 ofpbuf_use__(b, base, allocated, 0, OFPBUF_STACK);
76 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
77 * memory starting at 'base'. 'base' should point to a buffer on the stack.
78 * (Nothing actually relies on 'base' being allocated on the stack. It could
79 * be static or malloc()'d memory. But stack space is the most common use
82 * 'base' should be appropriately aligned. Using an array of uint32_t or
83 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
84 * for 32- or 64-bit data.
86 * An ofpbuf operation that requires reallocating data will copy the provided
87 * buffer into a malloc()'d buffer. Thus, it is wise to call ofpbuf_uninit()
88 * on an ofpbuf initialized by this function, so that if it expanded into the
89 * heap, that memory is freed. */
91 ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
93 ofpbuf_use__(b, base, allocated, 0, OFPBUF_STUB);
96 /* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
97 * 'size' bytes. This is appropriate for an ofpbuf that will be used to
98 * inspect existing data, without moving it around or reallocating it, and
99 * generally without modifying it at all.
101 * An ofpbuf operation that requires reallocating data will assert-fail if this
102 * function was used to initialize it. */
104 ofpbuf_use_const(struct ofpbuf *b, const void *data, size_t size)
106 ofpbuf_use__(b, CONST_CAST(void *, data), size, size, OFPBUF_STACK);
109 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
112 ofpbuf_init(struct ofpbuf *b, size_t size)
114 ofpbuf_use(b, size ? xmalloc(size) : NULL, size);
117 /* Frees memory that 'b' points to. */
119 ofpbuf_uninit(struct ofpbuf *b)
122 if (b->source == OFPBUF_MALLOC) {
128 /* Frees memory that 'b' points to and allocates a new ofpbuf */
130 ofpbuf_reinit(struct ofpbuf *b, size_t size)
133 ofpbuf_init(b, size);
136 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
139 ofpbuf_new(size_t size)
141 struct ofpbuf *b = xmalloc(sizeof *b);
142 ofpbuf_init(b, size);
146 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
147 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
149 ofpbuf_new_with_headroom(size_t size, size_t headroom)
151 struct ofpbuf *b = ofpbuf_new(size + headroom);
152 ofpbuf_reserve(b, headroom);
156 /* Creates and returns a new ofpbuf that initially contains a copy of the
157 * 'buffer->size' bytes of data starting at 'buffer->data' with no headroom or
160 ofpbuf_clone(const struct ofpbuf *buffer)
162 return ofpbuf_clone_with_headroom(buffer, 0);
165 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
166 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
168 ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom)
170 struct ofpbuf *new_buffer;
172 new_buffer = ofpbuf_clone_data_with_headroom(buffer->data,
175 if (buffer->header) {
177 = (char *)new_buffer->data - (char *)buffer->data;
179 new_buffer->header = (char *) buffer->header + data_delta;
181 new_buffer->msg = buffer->msg;
186 /* Creates and returns a new ofpbuf that initially contains a copy of the
187 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
189 ofpbuf_clone_data(const void *data, size_t size)
191 return ofpbuf_clone_data_with_headroom(data, size, 0);
194 /* Creates and returns a new ofpbuf that initially contains 'headroom' bytes of
195 * headroom followed by a copy of the 'size' bytes of data starting at
198 ofpbuf_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
200 struct ofpbuf *b = ofpbuf_new_with_headroom(size, headroom);
201 ofpbuf_put(b, data, size);
206 ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
207 size_t new_headroom, size_t new_tailroom)
209 const uint8_t *old_base = b->base;
210 size_t old_headroom = ofpbuf_headroom(b);
211 size_t old_tailroom = ofpbuf_tailroom(b);
212 size_t copy_headroom = MIN(old_headroom, new_headroom);
213 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
215 memcpy(&new_base[new_headroom - copy_headroom],
216 &old_base[old_headroom - copy_headroom],
217 copy_headroom + b->size + copy_tailroom);
220 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
221 * bytes of headroom and tailroom, respectively. */
223 ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
225 void *new_base, *new_data;
226 size_t new_allocated;
228 new_allocated = new_headroom + b->size + new_tailroom;
232 if (new_headroom == ofpbuf_headroom(b)) {
233 new_base = xrealloc(b->base, new_allocated);
235 new_base = xmalloc(new_allocated);
236 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
245 b->source = OFPBUF_MALLOC;
246 new_base = xmalloc(new_allocated);
247 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
254 b->allocated = new_allocated;
257 new_data = (char *) new_base + new_headroom;
258 if (b->data != new_data) {
260 uintptr_t data_delta = (char *) b->header - (char *) b->data;
262 b->header = (char *) new_data + data_delta;
265 uintptr_t data_delta = (char *) b->msg - (char *) b->data;
267 b->msg = (char *) new_data + data_delta;
273 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
274 * reallocating and copying its data if necessary. Its headroom, if any, is
277 ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size)
279 if (size > ofpbuf_tailroom(b)) {
280 ofpbuf_resize__(b, ofpbuf_headroom(b), MAX(size, 64));
284 /* Ensures that 'b' has room for at least 'size' bytes at its head,
285 * reallocating and copying its data if necessary. Its tailroom, if any, is
288 ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
290 if (size > ofpbuf_headroom(b)) {
291 ofpbuf_resize__(b, MAX(size, 64), ofpbuf_tailroom(b));
295 /* Trims the size of 'b' to fit its actual content, reducing its headroom and
296 * tailroom to 0, if any.
298 * Buffers not obtained from malloc() are not resized, since that wouldn't save
301 * Caller needs to updates 'b->header' and 'b->msg' so that they point to the
302 * same locations in the data. (If they pointed into the tailroom or headroom
303 * then they become invalid.)
307 ofpbuf_trim(struct ofpbuf *b)
309 if (b->source == OFPBUF_MALLOC
310 && (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
311 ofpbuf_resize__(b, 0, 0);
315 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
318 ofpbuf_padto(struct ofpbuf *b, size_t length)
320 if (b->size < length) {
321 ofpbuf_put_zeros(b, length - b->size);
325 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
326 * For example, a 'delta' of 1 would cause each byte of data to move one byte
327 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
328 * byte to move one byte backward (from 'p' to 'p-1').
330 * If used, user must make sure the 'header' and 'msg' pointers are updated
334 ofpbuf_shift(struct ofpbuf *b, int delta)
336 ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
337 : delta < 0 ? -delta <= ofpbuf_headroom(b)
341 char *dst = (char *) b->data + delta;
342 memmove(dst, b->data, b->size);
347 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
348 * copying its data if necessary. Returns a pointer to the first byte of the
349 * new data, which is left uninitialized. */
351 ofpbuf_put_uninit(struct ofpbuf *b, size_t size)
354 ofpbuf_prealloc_tailroom(b, size);
360 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
361 * reallocated and copied if necessary. Returns a pointer to the first byte of
362 * the data's location in the ofpbuf. */
364 ofpbuf_put_zeros(struct ofpbuf *b, size_t size)
366 void *dst = ofpbuf_put_uninit(b, size);
367 memset(dst, 0, size);
371 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
372 * is reallocated and copied if necessary. Returns a pointer to the first
373 * byte of the data's location in the ofpbuf. */
375 ofpbuf_put(struct ofpbuf *b, const void *p, size_t size)
377 void *dst = ofpbuf_put_uninit(b, size);
378 memcpy(dst, p, size);
382 /* Parses as many pairs of hex digits as possible (possibly separated by
383 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
384 * Returns the first character of 's' that is not the first of a pair of hex
385 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
388 ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n)
390 size_t initial_size = b->size;
395 s += strspn(s, " \t\r\n");
396 byte = hexits_value(s, 2, &ok);
399 *n = b->size - initial_size;
401 return CONST_CAST(char *, s);
404 ofpbuf_put(b, &byte, 1);
409 /* Reserves 'size' bytes of headroom so that they can be later allocated with
410 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
412 ofpbuf_reserve(struct ofpbuf *b, size_t size)
414 ovs_assert(!b->size);
415 ofpbuf_prealloc_tailroom(b, size);
416 b->data = (char*)b->data + size;
419 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
420 * data if necessary. Returns a pointer to the first byte of the data's
421 * location in the ofpbuf. The new data is left uninitialized. */
423 ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
425 ofpbuf_prealloc_headroom(b, size);
426 b->data = (char*)b->data - size;
431 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
432 * copying its data if necessary. Returns a pointer to the first byte of the
433 * data's location in the ofpbuf. */
435 ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
437 void *dst = ofpbuf_push_uninit(b, size);
438 memset(dst, 0, size);
442 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
443 * and copying its data if necessary. Returns a pointer to the first byte of
444 * the data's location in the ofpbuf. */
446 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size)
448 void *dst = ofpbuf_push_uninit(b, size);
449 memcpy(dst, p, size);
453 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
454 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
455 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
457 ofpbuf_steal_data(struct ofpbuf *b)
461 if (b->source == OFPBUF_MALLOC && b->data == b->base) {
464 p = xmemdup(b->data, b->size);
465 if (b->source == OFPBUF_MALLOC) {
476 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
477 * to 'maxbytes' from the start of the buffer. */
479 ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
484 ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
485 b->size, b->allocated,
486 ofpbuf_headroom(b), ofpbuf_tailroom(b));
487 ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
491 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
494 ofpbuf_list_delete(struct ovs_list *list)
498 LIST_FOR_EACH_POP (b, list_node, list) {