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 /* Converts ds into ofpbuf 'b'. 'b' contains the 'ds->allocated' bytes of
57 * memory starting at 'ds->string'. 'ds' should not be modified any more.
58 * The memory allocated for 'ds' will be freed (with free()) if 'b' is
59 * resized or freed. */
61 ofpbuf_use_ds(struct ofpbuf *b, const struct ds *ds)
63 ofpbuf_use__(b, ds->string, ds->allocated + 1, ds->length, OFPBUF_MALLOC);
66 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
67 * memory starting at 'base'. 'base' should point to a buffer on the stack.
68 * (Nothing actually relies on 'base' being allocated on the stack. It could
69 * be static or malloc()'d memory. But stack space is the most common use
72 * 'base' should be appropriately aligned. Using an array of uint32_t or
73 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
74 * for 32- or 64-bit data.
76 * An ofpbuf operation that requires reallocating data will assert-fail if this
77 * function was used to initialize it. Thus, one need not call ofpbuf_uninit()
78 * on an ofpbuf initialized by this function (though doing so is harmless),
79 * because it is guaranteed that 'b' does not own any heap-allocated memory. */
81 ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
83 ofpbuf_use__(b, base, allocated, 0, OFPBUF_STACK);
86 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
87 * memory starting at 'base'. 'base' should point to a buffer on the stack.
88 * (Nothing actually relies on 'base' being allocated on the stack. It could
89 * be static or malloc()'d memory. But stack space is the most common use
92 * 'base' should be appropriately aligned. Using an array of uint32_t or
93 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
94 * for 32- or 64-bit data.
96 * An ofpbuf operation that requires reallocating data will copy the provided
97 * buffer into a malloc()'d buffer. Thus, it is wise to call ofpbuf_uninit()
98 * on an ofpbuf initialized by this function, so that if it expanded into the
99 * heap, that memory is freed. */
101 ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
103 ofpbuf_use__(b, base, allocated, 0, OFPBUF_STUB);
106 /* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
107 * 'size' bytes. This is appropriate for an ofpbuf that will be used to
108 * inspect existing data, without moving it around or reallocating it, and
109 * generally without modifying it at all.
111 * An ofpbuf operation that requires reallocating data will assert-fail if this
112 * function was used to initialize it. */
114 ofpbuf_use_const(struct ofpbuf *b, const void *data, size_t size)
116 ofpbuf_use__(b, CONST_CAST(void *, data), size, size, OFPBUF_STACK);
119 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
122 ofpbuf_init(struct ofpbuf *b, size_t size)
124 ofpbuf_use(b, size ? xmalloc(size) : NULL, size);
127 /* Frees memory that 'b' points to. */
129 ofpbuf_uninit(struct ofpbuf *b)
132 if (b->source == OFPBUF_MALLOC) {
138 /* Frees memory that 'b' points to and allocates a new ofpbuf */
140 ofpbuf_reinit(struct ofpbuf *b, size_t size)
143 ofpbuf_init(b, size);
146 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
149 ofpbuf_new(size_t size)
151 struct ofpbuf *b = xmalloc(sizeof *b);
152 ofpbuf_init(b, size);
156 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
157 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
159 ofpbuf_new_with_headroom(size_t size, size_t headroom)
161 struct ofpbuf *b = ofpbuf_new(size + headroom);
162 ofpbuf_reserve(b, headroom);
166 /* Creates and returns a new ofpbuf that initially contains a copy of the
167 * 'buffer->size' bytes of data starting at 'buffer->data' with no headroom or
170 ofpbuf_clone(const struct ofpbuf *buffer)
172 return ofpbuf_clone_with_headroom(buffer, 0);
175 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
176 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
178 ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom)
180 struct ofpbuf *new_buffer;
182 new_buffer = ofpbuf_clone_data_with_headroom(buffer->data,
185 if (buffer->header) {
187 = (char *)new_buffer->data - (char *)buffer->data;
189 new_buffer->header = (char *) buffer->header + data_delta;
191 new_buffer->msg = buffer->msg;
196 /* Creates and returns a new ofpbuf that initially contains a copy of the
197 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
199 ofpbuf_clone_data(const void *data, size_t size)
201 return ofpbuf_clone_data_with_headroom(data, size, 0);
204 /* Creates and returns a new ofpbuf that initially contains 'headroom' bytes of
205 * headroom followed by a copy of the 'size' bytes of data starting at
208 ofpbuf_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
210 struct ofpbuf *b = ofpbuf_new_with_headroom(size, headroom);
211 ofpbuf_put(b, data, size);
216 ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
217 size_t new_headroom, size_t new_tailroom)
219 const uint8_t *old_base = b->base;
220 size_t old_headroom = ofpbuf_headroom(b);
221 size_t old_tailroom = ofpbuf_tailroom(b);
222 size_t copy_headroom = MIN(old_headroom, new_headroom);
223 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
225 memcpy(&new_base[new_headroom - copy_headroom],
226 &old_base[old_headroom - copy_headroom],
227 copy_headroom + b->size + copy_tailroom);
230 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
231 * bytes of headroom and tailroom, respectively. */
233 ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
235 void *new_base, *new_data;
236 size_t new_allocated;
238 new_allocated = new_headroom + b->size + new_tailroom;
242 if (new_headroom == ofpbuf_headroom(b)) {
243 new_base = xrealloc(b->base, new_allocated);
245 new_base = xmalloc(new_allocated);
246 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
255 b->source = OFPBUF_MALLOC;
256 new_base = xmalloc(new_allocated);
257 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
264 b->allocated = new_allocated;
267 new_data = (char *) new_base + new_headroom;
268 if (b->data != new_data) {
270 uintptr_t data_delta = (char *) b->header - (char *) b->data;
272 b->header = (char *) new_data + data_delta;
275 uintptr_t data_delta = (char *) b->msg - (char *) b->data;
277 b->msg = (char *) new_data + data_delta;
283 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
284 * reallocating and copying its data if necessary. Its headroom, if any, is
287 ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size)
289 if (size > ofpbuf_tailroom(b)) {
290 ofpbuf_resize__(b, ofpbuf_headroom(b), MAX(size, 64));
294 /* Ensures that 'b' has room for at least 'size' bytes at its head,
295 * reallocating and copying its data if necessary. Its tailroom, if any, is
298 ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
300 if (size > ofpbuf_headroom(b)) {
301 ofpbuf_resize__(b, MAX(size, 64), ofpbuf_tailroom(b));
305 /* Trims the size of 'b' to fit its actual content, reducing its headroom and
306 * tailroom to 0, if any.
308 * Buffers not obtained from malloc() are not resized, since that wouldn't save
311 * Caller needs to updates 'b->header' and 'b->msg' so that they point to the
312 * same locations in the data. (If they pointed into the tailroom or headroom
313 * then they become invalid.)
317 ofpbuf_trim(struct ofpbuf *b)
319 if (b->source == OFPBUF_MALLOC
320 && (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
321 ofpbuf_resize__(b, 0, 0);
325 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
328 ofpbuf_padto(struct ofpbuf *b, size_t length)
330 if (b->size < length) {
331 ofpbuf_put_zeros(b, length - b->size);
335 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
336 * For example, a 'delta' of 1 would cause each byte of data to move one byte
337 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
338 * byte to move one byte backward (from 'p' to 'p-1').
340 * If used, user must make sure the 'header' and 'msg' pointers are updated
344 ofpbuf_shift(struct ofpbuf *b, int delta)
346 ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
347 : delta < 0 ? -delta <= ofpbuf_headroom(b)
351 char *dst = (char *) b->data + delta;
352 memmove(dst, b->data, b->size);
357 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
358 * copying its data if necessary. Returns a pointer to the first byte of the
359 * new data, which is left uninitialized. */
361 ofpbuf_put_uninit(struct ofpbuf *b, size_t size)
364 ofpbuf_prealloc_tailroom(b, size);
370 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
371 * reallocated and copied if necessary. Returns a pointer to the first byte of
372 * the data's location in the ofpbuf. */
374 ofpbuf_put_zeros(struct ofpbuf *b, size_t size)
376 void *dst = ofpbuf_put_uninit(b, size);
377 memset(dst, 0, size);
381 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
382 * is reallocated and copied if necessary. Returns a pointer to the first
383 * byte of the data's location in the ofpbuf. */
385 ofpbuf_put(struct ofpbuf *b, const void *p, size_t size)
387 void *dst = ofpbuf_put_uninit(b, size);
388 memcpy(dst, p, size);
392 /* Parses as many pairs of hex digits as possible (possibly separated by
393 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
394 * Returns the first character of 's' that is not the first of a pair of hex
395 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
398 ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n)
400 size_t initial_size = b->size;
405 s += strspn(s, " \t\r\n");
406 byte = hexits_value(s, 2, &ok);
409 *n = b->size - initial_size;
411 return CONST_CAST(char *, s);
414 ofpbuf_put(b, &byte, 1);
419 /* Reserves 'size' bytes of headroom so that they can be later allocated with
420 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
422 ofpbuf_reserve(struct ofpbuf *b, size_t size)
424 ovs_assert(!b->size);
425 ofpbuf_prealloc_tailroom(b, size);
426 b->data = (char*)b->data + size;
429 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
430 * data if necessary. Returns a pointer to the first byte of the data's
431 * location in the ofpbuf. The new data is left uninitialized. */
433 ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
435 ofpbuf_prealloc_headroom(b, size);
436 b->data = (char*)b->data - size;
441 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
442 * copying its data if necessary. Returns a pointer to the first byte of the
443 * data's location in the ofpbuf. */
445 ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
447 void *dst = ofpbuf_push_uninit(b, size);
448 memset(dst, 0, size);
452 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
453 * and copying its data if necessary. Returns a pointer to the first byte of
454 * the data's location in the ofpbuf. */
456 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size)
458 void *dst = ofpbuf_push_uninit(b, size);
459 memcpy(dst, p, size);
463 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
464 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
465 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
467 ofpbuf_steal_data(struct ofpbuf *b)
471 if (b->source == OFPBUF_MALLOC && b->data == b->base) {
474 p = xmemdup(b->data, b->size);
475 if (b->source == OFPBUF_MALLOC) {
486 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
487 * to 'maxbytes' from the start of the buffer. */
489 ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
494 ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
495 b->size, b->allocated,
496 ofpbuf_headroom(b), ofpbuf_tailroom(b));
497 ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
501 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
504 ofpbuf_list_delete(struct ovs_list *list)
508 LIST_FOR_EACH_POP (b, list_node, list) {