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.
20 #include "dynamic-string.h"
21 #include "netdev-dpdk.h"
22 #include "dp-packet.h"
26 dp_packet_init__(struct dp_packet *b, size_t allocated, enum dp_packet_source source)
28 dp_packet_set_allocated(b, allocated);
30 dp_packet_reset_offsets(b);
31 pkt_metadata_init(&b->md, 0);
35 dp_packet_use__(struct dp_packet *b, void *base, size_t allocated,
36 enum dp_packet_source source)
38 dp_packet_set_base(b, base);
39 dp_packet_set_data(b, base);
40 dp_packet_set_size(b, 0);
42 dp_packet_init__(b, allocated, source);
45 /* Initializes 'b' as an empty dp_packet that contains the 'allocated' bytes of
46 * memory starting at 'base'. 'base' should be the first byte of a region
47 * obtained from malloc(). It will be freed (with free()) if 'b' is resized or
50 dp_packet_use(struct dp_packet *b, void *base, size_t allocated)
52 dp_packet_use__(b, base, allocated, DPBUF_MALLOC);
55 /* Initializes 'b' as an empty dp_packet that contains the 'allocated' bytes of
56 * memory starting at 'base'. 'base' should point to a buffer on the stack.
57 * (Nothing actually relies on 'base' being allocated on the stack. It could
58 * be static or malloc()'d memory. But stack space is the most common use
61 * 'base' should be appropriately aligned. Using an array of uint32_t or
62 * uint64_t for the buffer is a reasonable way to ensure appropriate alignment
63 * for 32- or 64-bit data.
65 * An dp_packet operation that requires reallocating data will copy the provided
66 * buffer into a malloc()'d buffer. Thus, it is wise to call dp_packet_uninit()
67 * on an dp_packet initialized by this function, so that if it expanded into the
68 * heap, that memory is freed. */
70 dp_packet_use_stub(struct dp_packet *b, void *base, size_t allocated)
72 dp_packet_use__(b, base, allocated, DPBUF_STUB);
75 /* Initializes 'b' as an dp_packet whose data starts at 'data' and continues for
76 * 'size' bytes. This is appropriate for an dp_packet that will be used to
77 * inspect existing data, without moving it around or reallocating it, and
78 * generally without modifying it at all.
80 * An dp_packet operation that requires reallocating data will assert-fail if this
81 * function was used to initialize it. */
83 dp_packet_use_const(struct dp_packet *b, const void *data, size_t size)
85 dp_packet_use__(b, CONST_CAST(void *, data), size, DPBUF_STACK);
86 dp_packet_set_size(b, size);
89 /* Initializes 'b' as an empty dp_packet that contains the 'allocated' bytes of
90 * memory starting at 'base'. DPDK allocated dp_packet and *data is allocated
91 * from one continous memory region, so in memory data start right after
92 * dp_packet. Therefore there is special method to free this type of
93 * buffer. dp_packet base, data and size are initialized by dpdk rcv() so no
94 * need to initialize those fields. */
96 dp_packet_init_dpdk(struct dp_packet *b, size_t allocated)
98 dp_packet_init__(b, allocated, DPBUF_DPDK);
101 /* Initializes 'b' as an empty dp_packet with an initial capacity of 'size'
104 dp_packet_init(struct dp_packet *b, size_t size)
106 dp_packet_use(b, size ? xmalloc(size) : NULL, size);
109 /* Frees memory that 'b' points to. */
111 dp_packet_uninit(struct dp_packet *b)
114 if (b->source == DPBUF_MALLOC) {
115 free(dp_packet_base(b));
116 } else if (b->source == DPBUF_DPDK) {
118 /* If this dp_packet was allocated by DPDK it must have been
119 * created as a dp_packet */
120 free_dpdk_buf((struct dp_packet*) b);
126 /* Creates and returns a new dp_packet with an initial capacity of 'size'
129 dp_packet_new(size_t size)
131 struct dp_packet *b = xmalloc(sizeof *b);
132 dp_packet_init(b, size);
136 /* Creates and returns a new dp_packet with an initial capacity of 'size +
137 * headroom' bytes, reserving the first 'headroom' bytes as headroom. */
139 dp_packet_new_with_headroom(size_t size, size_t headroom)
141 struct dp_packet *b = dp_packet_new(size + headroom);
142 dp_packet_reserve(b, headroom);
146 /* Creates and returns a new dp_packet that initially contains a copy of the
147 * 'dp_packet_size(buffer)' bytes of data starting at 'buffer->data' with no headroom or
150 dp_packet_clone(const struct dp_packet *buffer)
152 return dp_packet_clone_with_headroom(buffer, 0);
155 /* Creates and returns a new dp_packet whose data are copied from 'buffer'. The
156 * returned dp_packet will additionally have 'headroom' bytes of headroom. */
158 dp_packet_clone_with_headroom(const struct dp_packet *buffer, size_t headroom)
160 struct dp_packet *new_buffer;
162 new_buffer = dp_packet_clone_data_with_headroom(dp_packet_data(buffer),
163 dp_packet_size(buffer),
165 new_buffer->l2_pad_size = buffer->l2_pad_size;
166 new_buffer->l2_5_ofs = buffer->l2_5_ofs;
167 new_buffer->l3_ofs = buffer->l3_ofs;
168 new_buffer->l4_ofs = buffer->l4_ofs;
169 new_buffer->md = buffer->md;
174 /* Creates and returns a new dp_packet that initially contains a copy of the
175 * 'size' bytes of data starting at 'data' with no headroom or tailroom. */
177 dp_packet_clone_data(const void *data, size_t size)
179 return dp_packet_clone_data_with_headroom(data, size, 0);
182 /* Creates and returns a new dp_packet that initially contains 'headroom' bytes of
183 * headroom followed by a copy of the 'size' bytes of data starting at
186 dp_packet_clone_data_with_headroom(const void *data, size_t size, size_t headroom)
188 struct dp_packet *b = dp_packet_new_with_headroom(size, headroom);
189 dp_packet_put(b, data, size);
194 dp_packet_copy__(struct dp_packet *b, uint8_t *new_base,
195 size_t new_headroom, size_t new_tailroom)
197 const uint8_t *old_base = dp_packet_base(b);
198 size_t old_headroom = dp_packet_headroom(b);
199 size_t old_tailroom = dp_packet_tailroom(b);
200 size_t copy_headroom = MIN(old_headroom, new_headroom);
201 size_t copy_tailroom = MIN(old_tailroom, new_tailroom);
203 memcpy(&new_base[new_headroom - copy_headroom],
204 &old_base[old_headroom - copy_headroom],
205 copy_headroom + dp_packet_size(b) + copy_tailroom);
208 /* Reallocates 'b' so that it has exactly 'new_headroom' and 'new_tailroom'
209 * bytes of headroom and tailroom, respectively. */
211 dp_packet_resize__(struct dp_packet *b, size_t new_headroom, size_t new_tailroom)
213 void *new_base, *new_data;
214 size_t new_allocated;
216 new_allocated = new_headroom + dp_packet_size(b) + new_tailroom;
223 if (new_headroom == dp_packet_headroom(b)) {
224 new_base = xrealloc(dp_packet_base(b), new_allocated);
226 new_base = xmalloc(new_allocated);
227 dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
228 free(dp_packet_base(b));
236 b->source = DPBUF_MALLOC;
237 new_base = xmalloc(new_allocated);
238 dp_packet_copy__(b, new_base, new_headroom, new_tailroom);
245 dp_packet_set_allocated(b, new_allocated);
246 dp_packet_set_base(b, new_base);
248 new_data = (char *) new_base + new_headroom;
249 if (dp_packet_data(b) != new_data) {
250 dp_packet_set_data(b, new_data);
254 /* Ensures that 'b' has room for at least 'size' bytes at its tail end,
255 * reallocating and copying its data if necessary. Its headroom, if any, is
258 dp_packet_prealloc_tailroom(struct dp_packet *b, size_t size)
260 if (size > dp_packet_tailroom(b)) {
261 dp_packet_resize__(b, dp_packet_headroom(b), MAX(size, 64));
265 /* Ensures that 'b' has room for at least 'size' bytes at its head,
266 * reallocating and copying its data if necessary. Its tailroom, if any, is
269 dp_packet_prealloc_headroom(struct dp_packet *b, size_t size)
271 if (size > dp_packet_headroom(b)) {
272 dp_packet_resize__(b, MAX(size, 64), dp_packet_tailroom(b));
276 /* Shifts all of the data within the allocated space in 'b' by 'delta' bytes.
277 * For example, a 'delta' of 1 would cause each byte of data to move one byte
278 * forward (from address 'p' to 'p+1'), and a 'delta' of -1 would cause each
279 * byte to move one byte backward (from 'p' to 'p-1'). */
281 dp_packet_shift(struct dp_packet *b, int delta)
283 ovs_assert(delta > 0 ? delta <= dp_packet_tailroom(b)
284 : delta < 0 ? -delta <= dp_packet_headroom(b)
288 char *dst = (char *) dp_packet_data(b) + delta;
289 memmove(dst, dp_packet_data(b), dp_packet_size(b));
290 dp_packet_set_data(b, dst);
294 /* Appends 'size' bytes of data to the tail end of 'b', reallocating and
295 * copying its data if necessary. Returns a pointer to the first byte of the
296 * new data, which is left uninitialized. */
298 dp_packet_put_uninit(struct dp_packet *b, size_t size)
301 dp_packet_prealloc_tailroom(b, size);
302 p = dp_packet_tail(b);
303 dp_packet_set_size(b, dp_packet_size(b) + size);
307 /* Appends 'size' zeroed bytes to the tail end of 'b'. Data in 'b' is
308 * reallocated and copied if necessary. Returns a pointer to the first byte of
309 * the data's location in the dp_packet. */
311 dp_packet_put_zeros(struct dp_packet *b, size_t size)
313 void *dst = dp_packet_put_uninit(b, size);
314 memset(dst, 0, size);
318 /* Appends the 'size' bytes of data in 'p' to the tail end of 'b'. Data in 'b'
319 * is reallocated and copied if necessary. Returns a pointer to the first
320 * byte of the data's location in the dp_packet. */
322 dp_packet_put(struct dp_packet *b, const void *p, size_t size)
324 void *dst = dp_packet_put_uninit(b, size);
325 memcpy(dst, p, size);
329 /* Parses as many pairs of hex digits as possible (possibly separated by
330 * spaces) from the beginning of 's', appending bytes for their values to 'b'.
331 * Returns the first character of 's' that is not the first of a pair of hex
332 * digits. If 'n' is nonnull, stores the number of bytes added to 'b' in
335 dp_packet_put_hex(struct dp_packet *b, const char *s, size_t *n)
337 size_t initial_size = dp_packet_size(b);
342 s += strspn(s, " \t\r\n");
343 byte = hexits_value(s, 2, &ok);
346 *n = dp_packet_size(b) - initial_size;
348 return CONST_CAST(char *, s);
351 dp_packet_put(b, &byte, 1);
356 /* Reserves 'size' bytes of headroom so that they can be later allocated with
357 * dp_packet_push_uninit() without reallocating the dp_packet. */
359 dp_packet_reserve(struct dp_packet *b, size_t size)
361 ovs_assert(!dp_packet_size(b));
362 dp_packet_prealloc_tailroom(b, size);
363 dp_packet_set_data(b, (char*)dp_packet_data(b) + size);
366 /* Reserves 'headroom' bytes at the head and 'tailroom' at the end so that
367 * they can be later allocated with dp_packet_push_uninit() or
368 * dp_packet_put_uninit() without reallocating the dp_packet. */
370 dp_packet_reserve_with_tailroom(struct dp_packet *b, size_t headroom,
373 ovs_assert(!dp_packet_size(b));
374 dp_packet_prealloc_tailroom(b, headroom + tailroom);
375 dp_packet_set_data(b, (char*)dp_packet_data(b) + headroom);
378 /* Prefixes 'size' bytes to the head end of 'b', reallocating and copying its
379 * data if necessary. Returns a pointer to the first byte of the data's
380 * location in the dp_packet. The new data is left uninitialized. */
382 dp_packet_push_uninit(struct dp_packet *b, size_t size)
384 dp_packet_prealloc_headroom(b, size);
385 dp_packet_set_data(b, (char*)dp_packet_data(b) - size);
386 dp_packet_set_size(b, dp_packet_size(b) + size);
387 return dp_packet_data(b);
390 /* Prefixes 'size' zeroed bytes to the head end of 'b', reallocating and
391 * copying its data if necessary. Returns a pointer to the first byte of the
392 * data's location in the dp_packet. */
394 dp_packet_push_zeros(struct dp_packet *b, size_t size)
396 void *dst = dp_packet_push_uninit(b, size);
397 memset(dst, 0, size);
401 /* Copies the 'size' bytes starting at 'p' to the head end of 'b', reallocating
402 * and copying its data if necessary. Returns a pointer to the first byte of
403 * the data's location in the dp_packet. */
405 dp_packet_push(struct dp_packet *b, const void *p, size_t size)
407 void *dst = dp_packet_push_uninit(b, size);
408 memcpy(dst, p, size);
412 /* Returns the data in 'b' as a block of malloc()'d memory and frees the buffer
413 * within 'b'. (If 'b' itself was dynamically allocated, e.g. with
414 * dp_packet_new(), then it should still be freed with, e.g., dp_packet_delete().) */
416 dp_packet_steal_data(struct dp_packet *b)
419 ovs_assert(b->source != DPBUF_DPDK);
421 if (b->source == DPBUF_MALLOC && dp_packet_data(b) == dp_packet_base(b)) {
422 p = dp_packet_data(b);
424 p = xmemdup(dp_packet_data(b), dp_packet_size(b));
425 if (b->source == DPBUF_MALLOC) {
426 free(dp_packet_base(b));
429 dp_packet_set_base(b, NULL);
430 dp_packet_set_data(b, NULL);
434 /* Returns a string that describes some of 'b''s metadata plus a hex dump of up
435 * to 'maxbytes' from the start of the buffer. */
437 dp_packet_to_string(const struct dp_packet *b, size_t maxbytes)
442 ds_put_format(&s, "size=%"PRIu32", allocated=%"PRIu32", head=%"PRIuSIZE", tail=%"PRIuSIZE"\n",
443 dp_packet_size(b), dp_packet_get_allocated(b),
444 dp_packet_headroom(b), dp_packet_tailroom(b));
445 ds_put_hex_dump(&s, dp_packet_data(b), MIN(dp_packet_size(b), maxbytes), 0, false);
450 dp_packet_adjust_layer_offset(uint16_t *offset, int increment)
452 if (*offset != UINT16_MAX) {
453 *offset += increment;
457 /* Adjust the size of the l2_5 portion of the dp_packet, updating the l2
458 * pointer and the layer offsets. The caller is responsible for
459 * modifying the contents. */
461 dp_packet_resize_l2_5(struct dp_packet *b, int increment)
463 if (increment >= 0) {
464 dp_packet_push_uninit(b, increment);
466 dp_packet_pull(b, -increment);
469 /* Adjust layer offsets after l2_5. */
470 dp_packet_adjust_layer_offset(&b->l3_ofs, increment);
471 dp_packet_adjust_layer_offset(&b->l4_ofs, increment);
473 return dp_packet_data(b);
476 /* Adjust the size of the l2 portion of the dp_packet, updating the l2
477 * pointer and the layer offsets. The caller is responsible for
478 * modifying the contents. */
480 dp_packet_resize_l2(struct dp_packet *b, int increment)
482 dp_packet_resize_l2_5(b, increment);
483 dp_packet_adjust_layer_offset(&b->l2_5_ofs, increment);
484 return dp_packet_data(b);