]>
git.proxmox.com Git - ovs.git/blob - lib/ofpbuf.c
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 b
->l2_5_ofs
= b
->l3_ofs
= b
->l4_ofs
= UINT16_MAX
;
33 list_poison(&b
->list_node
);
37 ofpbuf_use__(struct ofpbuf
*b
, void *base
, size_t allocated
,
38 enum ofpbuf_source source
)
40 ofpbuf_set_base(b
, base
);
41 ofpbuf_set_data(b
, base
);
42 ofpbuf_set_size(b
, 0);
44 ofpbuf_init__(b
, allocated
, source
);
47 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
48 * memory starting at 'base'. 'base' should be the first byte of a region
49 * obtained from malloc(). It will be freed (with free()) if 'b' is resized or
52 ofpbuf_use(struct ofpbuf
*b
, void *base
, size_t allocated
)
54 ofpbuf_use__(b
, base
, allocated
, OFPBUF_MALLOC
);
57 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
58 * memory starting at 'base'. 'base' should point to a buffer on the stack.
59 * (Nothing actually relies on 'base' being allocated on the stack. It could
60 * be static or malloc()'d memory. But stack space is the most common use
63 * 'base' should be appropriately aligned. Using an array of uint32_t or
64 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
65 * for 32- or 64-bit data.
67 * An ofpbuf operation that requires reallocating data will assert-fail if this
68 * function was used to initialize it. Thus, one need not call ofpbuf_uninit()
69 * on an ofpbuf initialized by this function (though doing so is harmless),
70 * because it is guaranteed that 'b' does not own any heap-allocated memory. */
72 ofpbuf_use_stack(struct ofpbuf
*b
, void *base
, size_t allocated
)
74 ofpbuf_use__(b
, base
, allocated
, OFPBUF_STACK
);
77 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
78 * memory starting at 'base'. 'base' should point to a buffer on the stack.
79 * (Nothing actually relies on 'base' being allocated on the stack. It could
80 * be static or malloc()'d memory. But stack space is the most common use
83 * 'base' should be appropriately aligned. Using an array of uint32_t or
84 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
85 * for 32- or 64-bit data.
87 * An ofpbuf operation that requires reallocating data will copy the provided
88 * buffer into a malloc()'d buffer. Thus, it is wise to call ofpbuf_uninit()
89 * on an ofpbuf initialized by this function, so that if it expanded into the
90 * heap, that memory is freed. */
92 ofpbuf_use_stub(struct ofpbuf
*b
, void *base
, size_t allocated
)
94 ofpbuf_use__(b
, base
, allocated
, OFPBUF_STUB
);
97 /* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
98 * 'size' bytes. This is appropriate for an ofpbuf that will be used to
99 * inspect existing data, without moving it around or reallocating it, and
100 * generally without modifying it at all.
102 * An ofpbuf operation that requires reallocating data will assert-fail if this
103 * function was used to initialize it. */
105 ofpbuf_use_const(struct ofpbuf
*b
, const void *data
, size_t size
)
107 ofpbuf_use__(b
, CONST_CAST(void *, data
), size
, OFPBUF_STACK
);
108 ofpbuf_set_size(b
, size
);
111 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
112 * memory starting at 'base'. DPDK allocated ofpbuf and *data is allocated
113 * from one continous memory region, so in memory data start right after
114 * ofpbuf. Therefore there is special method to free this type of
115 * buffer. ofpbuf base, data and size are initialized by dpdk rcv() so no
116 * need to initialize those fields. */
118 ofpbuf_init_dpdk(struct ofpbuf
*b
, size_t allocated
)
120 ofpbuf_init__(b
, allocated
, OFPBUF_DPDK
);
123 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'
126 ofpbuf_init(struct ofpbuf
*b
, size_t size
)
128 ofpbuf_use(b
, size
? xmalloc(size
) : NULL
, size
);
131 /* Frees memory that 'b' points to. */
133 ofpbuf_uninit(struct ofpbuf
*b
)
136 if (b
->source
== OFPBUF_MALLOC
) {
137 free(ofpbuf_base(b
));
138 } else if (b
->source
== OFPBUF_DPDK
) {
140 /* If this ofpbuf was allocated by DPDK it must have been
141 * created as a dpif_packet */
142 free_dpdk_buf((struct dpif_packet
*) b
);
144 ovs_assert(b
->source
!= OFPBUF_DPDK
);
150 /* Frees memory that 'b' points to and allocates a new ofpbuf */
152 ofpbuf_reinit(struct ofpbuf
*b
, size_t size
)
155 ofpbuf_init(b
, size
);
158 /* Creates and returns a new ofpbuf with an initial capacity of 'size'
161 ofpbuf_new(size_t size
)
163 struct ofpbuf
*b
= xmalloc(sizeof *b
);
164 ofpbuf_init(b
, size
);
168 /* Creates and returns a new ofpbuf with an initial capacity of 'size +
169 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
171 ofpbuf_new_with_headroom(size_t size
, size_t headroom
)
173 struct ofpbuf
*b
= ofpbuf_new(size
+ headroom
);
174 ofpbuf_reserve(b
, headroom
);
178 /* Creates and returns a new ofpbuf that initially contains a copy of the
179 * 'ofpbuf_size(buffer)' bytes of data starting at 'buffer->data' with no headroom or
182 ofpbuf_clone(const struct ofpbuf
*buffer
)
184 return ofpbuf_clone_with_headroom(buffer
, 0);
187 /* Creates and returns a new ofpbuf whose data are copied from 'buffer'. The
188 * returned ofpbuf will additionally have 'headroom' bytes of headroom. */
190 ofpbuf_clone_with_headroom(const struct ofpbuf
*buffer
, size_t headroom
)
192 struct ofpbuf
*new_buffer
;
194 new_buffer
= ofpbuf_clone_data_with_headroom(ofpbuf_data(buffer
),
199 = (char *)ofpbuf_data(new_buffer
) - (char *)ofpbuf_data(buffer
);
201 new_buffer
->frame
= (char *) buffer
->frame
+ data_delta
;
203 new_buffer
->l2_pad_size
= buffer
->l2_pad_size
;
204 new_buffer
->l2_5_ofs
= buffer
->l2_5_ofs
;
205 new_buffer
->l3_ofs
= buffer
->l3_ofs
;
206 new_buffer
->l4_ofs
= buffer
->l4_ofs
;
211 /* Creates and returns a new ofpbuf that initially contains a copy of the
212 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
214 ofpbuf_clone_data(const void *data
, size_t size
)
216 return ofpbuf_clone_data_with_headroom(data
, size
, 0);
219 /* Creates and returns a new ofpbuf that initially contains 'headroom' bytes of
220 * headroom followed by a copy of the 'size' bytes of data starting at
223 ofpbuf_clone_data_with_headroom(const void *data
, size_t size
, size_t headroom
)
225 struct ofpbuf
*b
= ofpbuf_new_with_headroom(size
, headroom
);
226 ofpbuf_put(b
, data
, size
);
231 ofpbuf_copy__(struct ofpbuf
*b
, uint8_t *new_base
,
232 size_t new_headroom
, size_t new_tailroom
)
234 const uint8_t *old_base
= ofpbuf_base(b
);
235 size_t old_headroom
= ofpbuf_headroom(b
);
236 size_t old_tailroom
= ofpbuf_tailroom(b
);
237 size_t copy_headroom
= MIN(old_headroom
, new_headroom
);
238 size_t copy_tailroom
= MIN(old_tailroom
, new_tailroom
);
240 memcpy(&new_base
[new_headroom
- copy_headroom
],
241 &old_base
[old_headroom
- copy_headroom
],
242 copy_headroom
+ ofpbuf_size(b
) + copy_tailroom
);
245 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
246 * bytes of headroom and tailroom, respectively. */
248 ofpbuf_resize__(struct ofpbuf
*b
, size_t new_headroom
, size_t new_tailroom
)
250 void *new_base
, *new_data
;
251 size_t new_allocated
;
253 new_allocated
= new_headroom
+ ofpbuf_size(b
) + new_tailroom
;
260 if (new_headroom
== ofpbuf_headroom(b
)) {
261 new_base
= xrealloc(ofpbuf_base(b
), new_allocated
);
263 new_base
= xmalloc(new_allocated
);
264 ofpbuf_copy__(b
, new_base
, new_headroom
, new_tailroom
);
265 free(ofpbuf_base(b
));
273 b
->source
= OFPBUF_MALLOC
;
274 new_base
= xmalloc(new_allocated
);
275 ofpbuf_copy__(b
, new_base
, new_headroom
, new_tailroom
);
282 b
->allocated
= new_allocated
;
283 ofpbuf_set_base(b
, new_base
);
285 new_data
= (char *) new_base
+ new_headroom
;
286 if (ofpbuf_data(b
) != new_data
) {
288 uintptr_t data_delta
= (char *) new_data
- (char *) ofpbuf_data(b
);
290 b
->frame
= (char *) b
->frame
+ data_delta
;
292 ofpbuf_set_data(b
, new_data
);
296 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
297 * reallocating and copying its data if necessary. Its headroom, if any, is
300 ofpbuf_prealloc_tailroom(struct ofpbuf
*b
, size_t size
)
302 if (size
> ofpbuf_tailroom(b
)) {
303 ofpbuf_resize__(b
, ofpbuf_headroom(b
), MAX(size
, 64));
307 /* Ensures that 'b' has room for at least 'size' bytes at its head,
308 * reallocating and copying its data if necessary. Its tailroom, if any, is
311 ofpbuf_prealloc_headroom(struct ofpbuf
*b
, size_t size
)
313 if (size
> ofpbuf_headroom(b
)) {
314 ofpbuf_resize__(b
, MAX(size
, 64), ofpbuf_tailroom(b
));
318 /* Trims the size of 'b' to fit its actual content, reducing its headroom and
319 * tailroom to 0, if any.
321 * Buffers not obtained from malloc() are not resized, since that wouldn't save
324 ofpbuf_trim(struct ofpbuf
*b
)
326 ovs_assert(b
->source
!= OFPBUF_DPDK
);
328 if (b
->source
== OFPBUF_MALLOC
329 && (ofpbuf_headroom(b
) || ofpbuf_tailroom(b
))) {
330 ofpbuf_resize__(b
, 0, 0);
334 /* If 'b' is shorter than 'length' bytes, pads its tail out with zeros to that
337 ofpbuf_padto(struct ofpbuf
*b
, size_t length
)
339 if (ofpbuf_size(b
) < length
) {
340 ofpbuf_put_zeros(b
, length
- ofpbuf_size(b
));
344 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
345 * For example, a 'delta' of 1 would cause each byte of data to move one byte
346 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
347 * byte to move one byte backward (from 'p' to 'p-1'). */
349 ofpbuf_shift(struct ofpbuf
*b
, int delta
)
351 ovs_assert(delta
> 0 ? delta
<= ofpbuf_tailroom(b
)
352 : delta
< 0 ? -delta
<= ofpbuf_headroom(b
)
356 char *dst
= (char *) ofpbuf_data(b
) + delta
;
357 memmove(dst
, ofpbuf_data(b
), ofpbuf_size(b
));
358 ofpbuf_set_data(b
, dst
);
362 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
363 * copying its data if necessary. Returns a pointer to the first byte of the
364 * new data, which is left uninitialized. */
366 ofpbuf_put_uninit(struct ofpbuf
*b
, size_t size
)
369 ofpbuf_prealloc_tailroom(b
, size
);
371 ofpbuf_set_size(b
, ofpbuf_size(b
) + size
);
375 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
376 * reallocated and copied if necessary. Returns a pointer to the first byte of
377 * the data's location in the ofpbuf. */
379 ofpbuf_put_zeros(struct ofpbuf
*b
, size_t size
)
381 void *dst
= ofpbuf_put_uninit(b
, size
);
382 memset(dst
, 0, size
);
386 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
387 * is reallocated and copied if necessary. Returns a pointer to the first
388 * byte of the data's location in the ofpbuf. */
390 ofpbuf_put(struct ofpbuf
*b
, const void *p
, size_t size
)
392 void *dst
= ofpbuf_put_uninit(b
, size
);
393 memcpy(dst
, p
, size
);
397 /* Parses as many pairs of hex digits as possible (possibly separated by
398 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
399 * Returns the first character of 's' that is not the first of a pair of hex
400 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
403 ofpbuf_put_hex(struct ofpbuf
*b
, const char *s
, size_t *n
)
405 size_t initial_size
= ofpbuf_size(b
);
410 s
+= strspn(s
, " \t\r\n");
411 byte
= hexits_value(s
, 2, &ok
);
414 *n
= ofpbuf_size(b
) - initial_size
;
416 return CONST_CAST(char *, s
);
419 ofpbuf_put(b
, &byte
, 1);
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(struct ofpbuf
*b
, size_t size
)
429 ovs_assert(!ofpbuf_size(b
));
430 ofpbuf_prealloc_tailroom(b
, size
);
431 ofpbuf_set_data(b
, (char*)ofpbuf_data(b
) + size
);
434 /* Reserves 'headroom' bytes at the head and 'tailroom' at the end so that
435 * they can be later allocated with ofpbuf_push_uninit() or
436 * ofpbuf_put_uninit() without reallocating the ofpbuf. */
438 ofpbuf_reserve_with_tailroom(struct ofpbuf
*b
, size_t headroom
,
441 ovs_assert(!ofpbuf_size(b
));
442 ofpbuf_prealloc_tailroom(b
, headroom
+ tailroom
);
443 ofpbuf_set_data(b
, (char*)ofpbuf_data(b
) + headroom
);
446 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
447 * data if necessary. Returns a pointer to the first byte of the data's
448 * location in the ofpbuf. The new data is left uninitialized. */
450 ofpbuf_push_uninit(struct ofpbuf
*b
, size_t size
)
452 ofpbuf_prealloc_headroom(b
, size
);
453 ofpbuf_set_data(b
, (char*)ofpbuf_data(b
) - size
);
454 ofpbuf_set_size(b
, ofpbuf_size(b
) + size
);
455 return ofpbuf_data(b
);
458 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
459 * copying its data if necessary. Returns a pointer to the first byte of the
460 * data's location in the ofpbuf. */
462 ofpbuf_push_zeros(struct ofpbuf
*b
, size_t size
)
464 void *dst
= ofpbuf_push_uninit(b
, size
);
465 memset(dst
, 0, size
);
469 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
470 * and copying its data if necessary. Returns a pointer to the first byte of
471 * the data's location in the ofpbuf. */
473 ofpbuf_push(struct ofpbuf
*b
, const void *p
, size_t size
)
475 void *dst
= ofpbuf_push_uninit(b
, size
);
476 memcpy(dst
, p
, size
);
480 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
481 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
482 * ofpbuf_new(), then it should still be freed with, e.g., ofpbuf_delete().) */
484 ofpbuf_steal_data(struct ofpbuf
*b
)
487 ovs_assert(b
->source
!= OFPBUF_DPDK
);
489 if (b
->source
== OFPBUF_MALLOC
&& ofpbuf_data(b
) == ofpbuf_base(b
)) {
492 p
= xmemdup(ofpbuf_data(b
), ofpbuf_size(b
));
493 if (b
->source
== OFPBUF_MALLOC
) {
494 free(ofpbuf_base(b
));
497 ofpbuf_set_base(b
, NULL
);
498 ofpbuf_set_data(b
, NULL
);
502 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
503 * to 'maxbytes' from the start of the buffer. */
505 ofpbuf_to_string(const struct ofpbuf
*b
, size_t maxbytes
)
510 ds_put_format(&s
, "size=%"PRIu32
", allocated=%"PRIu32
", head=%"PRIuSIZE
", tail=%"PRIuSIZE
"\n",
511 ofpbuf_size(b
), b
->allocated
,
512 ofpbuf_headroom(b
), ofpbuf_tailroom(b
));
513 ds_put_hex_dump(&s
, ofpbuf_data(b
), MIN(ofpbuf_size(b
), maxbytes
), 0, false);
517 /* Removes each of the "struct ofpbuf"s on 'list' from the list and frees
520 ofpbuf_list_delete(struct list
*list
)
522 struct ofpbuf
*b
, *next
;
524 LIST_FOR_EACH_SAFE (b
, next
, list_node
, list
) {
525 list_remove(&b
->list_node
);
531 ofpbuf_adjust_layer_offset(uint16_t *offset
, int increment
)
533 if (*offset
!= UINT16_MAX
) {
534 *offset
+= increment
;
538 /* Adjust the size of the l2_5 portion of the ofpbuf, updating the l2
539 * pointer and the layer offsets. The caller is responsible for
540 * modifying the contents. */
542 ofpbuf_resize_l2_5(struct ofpbuf
*b
, int increment
)
544 if (increment
>= 0) {
545 ofpbuf_push_uninit(b
, increment
);
547 ofpbuf_pull(b
, -increment
);
550 b
->frame
= ofpbuf_data(b
);
551 /* Adjust layer offsets after l2_5. */
552 ofpbuf_adjust_layer_offset(&b
->l3_ofs
, increment
);
553 ofpbuf_adjust_layer_offset(&b
->l4_ofs
, increment
);
558 /* Adjust the size of the l2 portion of the ofpbuf, updating the l2
559 * pointer and the layer offsets. The caller is responsible for
560 * modifying the contents. */
562 ofpbuf_resize_l2(struct ofpbuf
*b
, int increment
)
564 ofpbuf_resize_l2_5(b
, increment
);
565 ofpbuf_adjust_layer_offset(&b
->l2_5_ofs
, increment
);