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;
31 b->l2_5_ofs = b->l3_ofs = b->l4_ofs = UINT16_MAX;
32 list_poison(&b->list_node);
36 ofpbuf_use__(struct ofpbuf *b, void *base, size_t allocated,
37 enum ofpbuf_source source)
39 ofpbuf_set_base(b, base);
40 ofpbuf_set_data(b, base);
41 ofpbuf_set_size(b, 0);
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);
107 ofpbuf_set_size(b, size);
110 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
111 * memory starting at 'base'. DPDK allocated ofpbuf and *data is allocated
112 * from one continous memory region, so in memory data start right after
113 * ofpbuf. Therefore there is special method to free this type of
114 * buffer. ofpbuf base, data and size are initialized by dpdk rcv() so no
115 * need to initialize those fields. */
117 ofpbuf_init_dpdk(struct ofpbuf *b, size_t allocated)
119 ofpbuf_init__(b, allocated, OFPBUF_DPDK);
122 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
125 ofpbuf_init(struct ofpbuf *b, size_t size)
127 ofpbuf_use(b, size ? xmalloc(size) : NULL, size);
130 /* Frees memory that 'b' points to. */
132 ofpbuf_uninit(struct ofpbuf *b)
135 if (b->source == OFPBUF_MALLOC) {
136 free(ofpbuf_base(b));
138 ovs_assert(b->source != OFPBUF_DPDK);
142 /* Frees memory that 'b' points to and allocates a new ofpbuf */
144 ofpbuf_reinit(struct ofpbuf *b, size_t size)
147 ofpbuf_init(b, size);
150 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
153 ofpbuf_new(size_t size)
155 struct ofpbuf *b = xmalloc(sizeof *b);
156 ofpbuf_init(b, size);
160 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
161 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
163 ofpbuf_new_with_headroom(size_t size, size_t headroom)
165 struct ofpbuf *b = ofpbuf_new(size + headroom);
166 ofpbuf_reserve(b, headroom);
170 /* Creates and returns a new ofpbuf that initially contains a copy of the
171 * 'ofpbuf_size(buffer)' bytes of data starting at 'buffer->data' with no headroom or
174 ofpbuf_clone(const struct ofpbuf *buffer)
176 return ofpbuf_clone_with_headroom(buffer, 0);
179 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
180 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
182 ofpbuf_clone_with_headroom(const struct ofpbuf *buffer, size_t headroom)
184 struct ofpbuf *new_buffer;
186 new_buffer = ofpbuf_clone_data_with_headroom(ofpbuf_data(buffer),
190 uintptr_t data_delta = (char *)ofpbuf_data(new_buffer) - (char *)ofpbuf_data(buffer);
192 new_buffer->l2 = (char *) buffer->l2 + data_delta;
194 new_buffer->l2_5_ofs = buffer->l2_5_ofs;
195 new_buffer->l3_ofs = buffer->l3_ofs;
196 new_buffer->l4_ofs = buffer->l4_ofs;
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);
221 ofpbuf_copy__(struct ofpbuf *b, uint8_t *new_base,
222 size_t new_headroom, size_t new_tailroom)
224 const uint8_t *old_base = ofpbuf_base(b);
225 size_t old_headroom = ofpbuf_headroom(b);
226 size_t old_tailroom = ofpbuf_tailroom(b);
227 size_t copy_headroom = MIN(old_headroom, new_headroom);
228 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
230 memcpy(&new_base[new_headroom - copy_headroom],
231 &old_base[old_headroom - copy_headroom],
232 copy_headroom + ofpbuf_size(b) + copy_tailroom);
235 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
236 * bytes of headroom and tailroom, respectively. */
238 ofpbuf_resize__(struct ofpbuf *b, size_t new_headroom, size_t new_tailroom)
240 void *new_base, *new_data;
241 size_t new_allocated;
243 new_allocated = new_headroom + ofpbuf_size(b) + new_tailroom;
250 if (new_headroom == ofpbuf_headroom(b)) {
251 new_base = xrealloc(ofpbuf_base(b), new_allocated);
253 new_base = xmalloc(new_allocated);
254 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
255 free(ofpbuf_base(b));
263 b->source = OFPBUF_MALLOC;
264 new_base = xmalloc(new_allocated);
265 ofpbuf_copy__(b, new_base, new_headroom, new_tailroom);
272 b->allocated = new_allocated;
273 ofpbuf_set_base(b, new_base);
275 new_data = (char *) new_base + new_headroom;
276 if (ofpbuf_data(b) != new_data) {
277 uintptr_t data_delta = (char *) new_data - (char *) ofpbuf_data(b);
279 ofpbuf_set_data(b, new_data);
281 b->l2 = (char *) b->l2 + data_delta;
286 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
287 * reallocating and copying its data if necessary. Its headroom, if any, is
290 ofpbuf_prealloc_tailroom(struct ofpbuf *b, size_t size)
292 if (size > ofpbuf_tailroom(b)) {
293 ofpbuf_resize__(b, ofpbuf_headroom(b), MAX(size, 64));
297 /* Ensures that 'b' has room for at least 'size' bytes at its head,
298 * reallocating and copying its data if necessary. Its tailroom, if any, is
301 ofpbuf_prealloc_headroom(struct ofpbuf *b, size_t size)
303 if (size > ofpbuf_headroom(b)) {
304 ofpbuf_resize__(b, MAX(size, 64), ofpbuf_tailroom(b));
308 /* Trims the size of 'b' to fit its actual content, reducing its tailroom to
309 * 0. Its headroom, if any, is preserved.
311 * Buffers not obtained from malloc() are not resized, since that wouldn't save
314 ofpbuf_trim(struct ofpbuf *b)
316 ovs_assert(b->source != OFPBUF_DPDK);
318 if (b->source == OFPBUF_MALLOC
319 && (ofpbuf_headroom(b) || ofpbuf_tailroom(b))) {
320 ofpbuf_resize__(b, 0, 0);
324 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
327 ofpbuf_padto(struct ofpbuf *b, size_t length)
329 if (ofpbuf_size(b) < length) {
330 ofpbuf_put_zeros(b, length - ofpbuf_size(b));
334 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
335 * For example, a 'delta' of 1 would cause each byte of data to move one byte
336 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
337 * byte to move one byte backward (from 'p' to 'p-1'). */
339 ofpbuf_shift(struct ofpbuf *b, int delta)
341 ovs_assert(delta > 0 ? delta <= ofpbuf_tailroom(b)
342 : delta < 0 ? -delta <= ofpbuf_headroom(b)
346 char *dst = (char *) ofpbuf_data(b) + delta;
347 memmove(dst, ofpbuf_data(b), ofpbuf_size(b));
348 ofpbuf_set_data(b, dst);
352 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
353 * copying its data if necessary. Returns a pointer to the first byte of the
354 * new data, which is left uninitialized. */
356 ofpbuf_put_uninit(struct ofpbuf *b, size_t size)
359 ofpbuf_prealloc_tailroom(b, size);
361 ofpbuf_set_size(b, ofpbuf_size(b) + size);
365 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
366 * reallocated and copied if necessary. Returns a pointer to the first byte of
367 * the data's location in the ofpbuf. */
369 ofpbuf_put_zeros(struct ofpbuf *b, size_t size)
371 void *dst = ofpbuf_put_uninit(b, size);
372 memset(dst, 0, size);
376 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
377 * is reallocated and copied if necessary. Returns a pointer to the first
378 * byte of the data's location in the ofpbuf. */
380 ofpbuf_put(struct ofpbuf *b, const void *p, size_t size)
382 void *dst = ofpbuf_put_uninit(b, size);
383 memcpy(dst, p, size);
387 /* Parses as many pairs of hex digits as possible (possibly separated by
388 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
389 * Returns the first character of 's' that is not the first of a pair of hex
390 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
393 ofpbuf_put_hex(struct ofpbuf *b, const char *s, size_t *n)
395 size_t initial_size = ofpbuf_size(b);
400 s += strspn(s, " \t\r\n");
401 byte = hexits_value(s, 2, &ok);
404 *n = ofpbuf_size(b) - initial_size;
406 return CONST_CAST(char *, s);
409 ofpbuf_put(b, &byte, 1);
414 /* Reserves 'size' bytes of headroom so that they can be later allocated with
415 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
417 ofpbuf_reserve(struct ofpbuf *b, size_t size)
419 ovs_assert(!ofpbuf_size(b));
420 ofpbuf_prealloc_tailroom(b, size);
421 ofpbuf_set_data(b, (char*)ofpbuf_data(b) + size);
424 /* Reserves 'size' bytes of headroom so that they can be later allocated with
425 * ofpbuf_push_uninit() without reallocating the ofpbuf. */
427 ofpbuf_reserve_with_tailroom(struct ofpbuf *b, size_t headroom,
430 ovs_assert(!ofpbuf_size(b));
431 ofpbuf_prealloc_tailroom(b, headroom + tailroom);
432 ofpbuf_set_data(b, (char*)ofpbuf_data(b) + headroom);
435 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
436 * data if necessary. Returns a pointer to the first byte of the data's
437 * location in the ofpbuf. The new data is left uninitialized. */
439 ofpbuf_push_uninit(struct ofpbuf *b, size_t size)
441 ofpbuf_prealloc_headroom(b, size);
442 ofpbuf_set_data(b, (char*)ofpbuf_data(b) - size);
443 ofpbuf_set_size(b, ofpbuf_size(b) + size);
444 return ofpbuf_data(b);
447 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
448 * copying its data if necessary. Returns a pointer to the first byte of the
449 * data's location in the ofpbuf. */
451 ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
453 void *dst = ofpbuf_push_uninit(b, size);
454 memset(dst, 0, size);
458 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
459 * and copying its data if necessary. Returns a pointer to the first byte of
460 * the data's location in the ofpbuf. */
462 ofpbuf_push(struct ofpbuf *b, const void *p, size_t size)
464 void *dst = ofpbuf_push_uninit(b, size);
465 memcpy(dst, p, size);
469 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
470 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
471 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
473 ofpbuf_steal_data(struct ofpbuf *b)
476 ovs_assert(b->source != OFPBUF_DPDK);
478 if (b->source == OFPBUF_MALLOC && ofpbuf_data(b) == ofpbuf_base(b)) {
481 p = xmemdup(ofpbuf_data(b), ofpbuf_size(b));
482 if (b->source == OFPBUF_MALLOC) {
483 free(ofpbuf_base(b));
486 ofpbuf_set_base(b, NULL);
487 ofpbuf_set_data(b, NULL);
491 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
492 * to 'maxbytes' from the start of the buffer. */
494 ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
499 ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
500 ofpbuf_size(b), b->allocated,
501 ofpbuf_headroom(b), ofpbuf_tailroom(b));
502 ds_put_hex_dump(&s, ofpbuf_data(b), MIN(ofpbuf_size(b), maxbytes), 0, false);
506 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
509 ofpbuf_list_delete(struct list *list)
511 struct ofpbuf *b, *next;
513 LIST_FOR_EACH_SAFE (b, next, list_node, list) {
514 list_remove(&b->list_node);
520 ofpbuf_adjust_layer_offset(uint16_t *offset, int increment)
522 if (*offset != UINT16_MAX) {
523 *offset += increment;
527 /* Adjust the size of the l2_5 portion of the ofpbuf, updating the l2
528 * pointer and the layer offsets. The caller is responsible for
529 * modifying the contents. */
531 ofpbuf_resize_l2_5(struct ofpbuf *b, int increment)
533 if (increment >= 0) {
534 ofpbuf_push_uninit(b, increment);
536 ofpbuf_pull(b, -increment);
539 b->l2 = ofpbuf_data(b);
540 /* Adjust layer offsets after l2_5. */
541 ofpbuf_adjust_layer_offset(&b->l3_ofs, increment);
542 ofpbuf_adjust_layer_offset(&b->l4_ofs, increment);
547 /* Adjust the size of the l2 portion of the ofpbuf, updating the l2
548 * pointer and the layer offsets. The caller is responsible for
549 * modifying the contents. */
551 ofpbuf_resize_l2(struct ofpbuf *b, int increment)
553 ofpbuf_resize_l2_5(b, increment);
554 ofpbuf_adjust_layer_offset(&b->l2_5_ofs, increment);