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,
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, 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, 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, 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, OFPBUF_STACK);
110 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
113 ofpbuf_init(struct ofpbuf *b, size_t size)
115 ofpbuf_use(b, size ? xmalloc(size) : NULL, size);
118 /* Frees memory that 'b' points to. */
120 ofpbuf_uninit(struct ofpbuf *b)
123 if (b->source == OFPBUF_MALLOC) {
129 /* Frees memory that 'b' points to and allocates a new ofpbuf */
131 ofpbuf_reinit(struct ofpbuf *b, size_t size)
134 ofpbuf_init(b, size);
137 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
140 ofpbuf_new(size_t size)
142 struct ofpbuf *b = xmalloc(sizeof *b);
143 ofpbuf_init(b, size);
147 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
148 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
150 ofpbuf_new_with_headroom(size_t size, size_t headroom)
152 struct ofpbuf *b = ofpbuf_new(size + headroom);
153 ofpbuf_reserve(b, headroom);
157 /* Creates and returns a new ofpbuf that initially contains a copy of the
158 * 'buffer->size' bytes of data starting at 'buffer->data' with no headroom or
161 ofpbuf_clone(const struct ofpbuf *buffer)
163 return ofpbuf_clone_with_headroom(buffer, 0);
166 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
167 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
169 ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom)
171 struct ofpbuf *new_buffer;
173 new_buffer = ofpbuf_clone_data_with_headroom(buffer->data,
176 if (buffer->header) {
178 = (char *)new_buffer->data - (char *)buffer->data;
180 new_buffer->header = (char *) buffer->header + data_delta;
182 new_buffer->msg = buffer->msg;
187 /* Creates and returns a new ofpbuf that initially contains a copy of the
188 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
190 ofpbuf_clone_data(const void *data, size_t size)
192 return ofpbuf_clone_data_with_headroom(data, size, 0);
195 /* Creates and returns a new ofpbuf that initially contains 'headroom' bytes of
196 * headroom followed by a copy of the 'size' bytes of data starting at
199 ofpbuf_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
201 struct ofpbuf *b = ofpbuf_new_with_headroom(size, headroom);
202 ofpbuf_put(b, data, size);
207 ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
208 size_t new_headroom, size_t new_tailroom)
210 const uint8_t *old_base = b->base;
211 size_t old_headroom = ofpbuf_headroom(b);
212 size_t old_tailroom = ofpbuf_tailroom(b);
213 size_t copy_headroom = MIN(old_headroom, new_headroom);
214 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
216 memcpy(&new_base[new_headroom - copy_headroom],
217 &old_base[old_headroom - copy_headroom],
218 copy_headroom + b->size + copy_tailroom);
221 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
222 * bytes of headroom and tailroom, respectively. */
224 ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
226 void *new_base, *new_data;
227 size_t new_allocated;
229 new_allocated = new_headroom + b->size + new_tailroom;
233 if (new_headroom == ofpbuf_headroom(b)) {
234 new_base = xrealloc(b->base, new_allocated);
236 new_base = xmalloc(new_allocated);
237 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
246 b->source = OFPBUF_MALLOC;
247 new_base = xmalloc(new_allocated);
248 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
255 b->allocated = new_allocated;
258 new_data = (char *) new_base + new_headroom;
259 if (b->data != new_data) {
261 uintptr_t data_delta = (char *) new_data - (char *) b->data;
263 b->header = (char *) b->header + data_delta;
269 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
270 * reallocating and copying its data if necessary. Its headroom, if any, is
273 ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size)
275 if (size > ofpbuf_tailroom(b)) {
276 ofpbuf_resize__(b, ofpbuf_headroom(b), MAX(size, 64));
280 /* Ensures that 'b' has room for at least 'size' bytes at its head,
281 * reallocating and copying its data if necessary. Its tailroom, if any, is
284 ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
286 if (size > ofpbuf_headroom(b)) {
287 ofpbuf_resize__(b, MAX(size, 64), ofpbuf_tailroom(b));
291 /* Trims the size of 'b' to fit its actual content, reducing its headroom and
292 * tailroom to 0, if any.
294 * Buffers not obtained from malloc() are not resized, since that wouldn't save
297 ofpbuf_trim(struct ofpbuf *b)
299 if (b->source == OFPBUF_MALLOC
300 && (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
301 ofpbuf_resize__(b, 0, 0);
305 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
308 ofpbuf_padto(struct ofpbuf *b, size_t length)
310 if (b->size < length) {
311 ofpbuf_put_zeros(b, length - b->size);
315 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
316 * For example, a 'delta' of 1 would cause each byte of data to move one byte
317 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
318 * byte to move one byte backward (from 'p' to 'p-1'). */
320 ofpbuf_shift(struct ofpbuf *b, int delta)
322 ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
323 : delta < 0 ? -delta <= ofpbuf_headroom(b)
327 char *dst = (char *) b->data + delta;
328 memmove(dst, b->data, b->size);
333 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
334 * copying its data if necessary. Returns a pointer to the first byte of the
335 * new data, which is left uninitialized. */
337 ofpbuf_put_uninit(struct ofpbuf *b, size_t size)
340 ofpbuf_prealloc_tailroom(b, size);
346 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
347 * reallocated and copied if necessary. Returns a pointer to the first byte of
348 * the data's location in the ofpbuf. */
350 ofpbuf_put_zeros(struct ofpbuf *b, size_t size)
352 void *dst = ofpbuf_put_uninit(b, size);
353 memset(dst, 0, size);
357 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
358 * is reallocated and copied if necessary. Returns a pointer to the first
359 * byte of the data's location in the ofpbuf. */
361 ofpbuf_put(struct ofpbuf *b, const void *p, size_t size)
363 void *dst = ofpbuf_put_uninit(b, size);
364 memcpy(dst, p, size);
368 /* Parses as many pairs of hex digits as possible (possibly separated by
369 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
370 * Returns the first character of 's' that is not the first of a pair of hex
371 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
374 ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n)
376 size_t initial_size = b->size;
381 s += strspn(s, " \t\r\n");
382 byte = hexits_value(s, 2, &ok);
385 *n = b->size - initial_size;
387 return CONST_CAST(char *, s);
390 ofpbuf_put(b, &byte, 1);
395 /* Reserves 'size' bytes of headroom so that they can be later allocated with
396 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
398 ofpbuf_reserve(struct ofpbuf *b, size_t size)
400 ovs_assert(!b->size);
401 ofpbuf_prealloc_tailroom(b, size);
402 b->data = (char*)b->data + size;
405 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
406 * data if necessary. Returns a pointer to the first byte of the data's
407 * location in the ofpbuf. The new data is left uninitialized. */
409 ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
411 ofpbuf_prealloc_headroom(b, size);
412 b->data = (char*)b->data - size;
417 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
418 * copying its data if necessary. Returns a pointer to the first byte of the
419 * data's location in the ofpbuf. */
421 ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
423 void *dst = ofpbuf_push_uninit(b, size);
424 memset(dst, 0, size);
428 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
429 * and copying its data if necessary. Returns a pointer to the first byte of
430 * the data's location in the ofpbuf. */
432 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size)
434 void *dst = ofpbuf_push_uninit(b, size);
435 memcpy(dst, p, size);
439 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
440 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
441 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
443 ofpbuf_steal_data(struct ofpbuf *b)
447 if (b->source == OFPBUF_MALLOC && b->data == b->base) {
450 p = xmemdup(b->data, b->size);
451 if (b->source == OFPBUF_MALLOC) {
460 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
461 * to 'maxbytes' from the start of the buffer. */
463 ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
468 ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
469 b->size, b->allocated,
470 ofpbuf_headroom(b), ofpbuf_tailroom(b));
471 ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
475 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
478 ofpbuf_list_delete(struct ovs_list *list)
480 struct ofpbuf *b, *next;
482 LIST_FOR_EACH_SAFE (b, next, list_node, list) {
483 list_remove(&b->list_node);