lib/dp-packet.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
   3  *
   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:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #ifndef DPBUF_H
  18 #define DPBUF_H 1
  19
  20 #include <stddef.h>
  21 #include <stdint.h>
  22 #include "list.h"
  23 #include "packets.h"
  24 #include "util.h"
  25 #include "netdev-dpdk.h"
  26
  27 #ifdef  __cplusplus
  28 extern "C" {
  29 #endif
  30
  31 enum OVS_PACKED_ENUM dp_packet_source {
  32     DPBUF_MALLOC,              /* Obtained via malloc(). */
  33     DPBUF_STACK,               /* Un-movable stack space or static buffer. */
  34     DPBUF_STUB,                /* Starts on stack, may expand into heap. */
  35     DPBUF_DPDK,                /* buffer data is from DPDK allocated memory.
  36                                 * ref to build_dp_packet() in netdev-dpdk. */
  37 };
  38
  39 /* Buffer for holding packet data.  A dp_packet is automatically reallocated
  40  * as necessary if it grows too large for the available memory.
  41  */
  42 struct dp_packet {
  43 #ifdef DPDK_NETDEV
  44     struct rte_mbuf mbuf;       /* DPDK mbuf */
  45 #else
  46     void *base_;                /* First byte of allocated space. */
  47     uint16_t allocated_;        /* Number of bytes allocated. */
  48     uint16_t data_ofs;          /* First byte actually in use. */
  49     uint32_t size_;             /* Number of bytes in use. */
  50     uint32_t rss_hash;          /* Packet hash. */
  51 #endif
  52     enum dp_packet_source source;  /* Source of memory allocated as 'base'. */
  53     uint8_t l2_pad_size;           /* Detected l2 padding size.
  54                                     * Padding is non-pullable. */
  55     uint16_t l2_5_ofs;             /* MPLS label stack offset, or UINT16_MAX */
  56     uint16_t l3_ofs;               /* Network-level header offset,
  57                                     * or UINT16_MAX. */
  58     uint16_t l4_ofs;               /* Transport-level header offset,
  59                                       or UINT16_MAX. */
  60     struct pkt_metadata md;
  61 };
  62
  63 static inline void *dp_packet_data(const struct dp_packet *);
  64 static inline void dp_packet_set_data(struct dp_packet *, void *);
  65 static inline void *dp_packet_base(const struct dp_packet *);
  66 static inline void dp_packet_set_base(struct dp_packet *, void *);
  67
  68 static inline uint32_t dp_packet_size(const struct dp_packet *);
  69 static inline void dp_packet_set_size(struct dp_packet *, uint32_t);
  70
  71 static inline uint16_t dp_packet_get_allocated(const struct dp_packet *);
  72 static inline void dp_packet_set_allocated(struct dp_packet *, uint16_t);
  73
  74 void *dp_packet_resize_l2(struct dp_packet *, int increment);
  75 void *dp_packet_resize_l2_5(struct dp_packet *, int increment);
  76 static inline void *dp_packet_l2(const struct dp_packet *);
  77 static inline void dp_packet_reset_offsets(struct dp_packet *);
  78 static inline uint8_t dp_packet_l2_pad_size(const struct dp_packet *);
  79 static inline void dp_packet_set_l2_pad_size(struct dp_packet *, uint8_t);
  80 static inline void *dp_packet_l2_5(const struct dp_packet *);
  81 static inline void dp_packet_set_l2_5(struct dp_packet *, void *);
  82 static inline void *dp_packet_l3(const struct dp_packet *);
  83 static inline void dp_packet_set_l3(struct dp_packet *, void *);
  84 static inline void *dp_packet_l4(const struct dp_packet *);
  85 static inline void dp_packet_set_l4(struct dp_packet *, void *);
  86 static inline size_t dp_packet_l4_size(const struct dp_packet *);
  87 static inline const void *dp_packet_get_tcp_payload(const struct dp_packet *);
  88 static inline const void *dp_packet_get_udp_payload(const struct dp_packet *);
  89 static inline const void *dp_packet_get_sctp_payload(const struct dp_packet *);
  90 static inline const void *dp_packet_get_icmp_payload(const struct dp_packet *);
  91 static inline const void *dp_packet_get_nd_payload(const struct dp_packet *);
  92
  93 void dp_packet_use(struct dp_packet *, void *, size_t);
  94 void dp_packet_use_stub(struct dp_packet *, void *, size_t);
  95 void dp_packet_use_const(struct dp_packet *, const void *, size_t);
  96
  97 void dp_packet_init_dpdk(struct dp_packet *, size_t allocated);
  98
  99 void dp_packet_init(struct dp_packet *, size_t);
 100 void dp_packet_uninit(struct dp_packet *);
 101
 102 struct dp_packet *dp_packet_new(size_t);
 103 struct dp_packet *dp_packet_new_with_headroom(size_t, size_t headroom);
 104 struct dp_packet *dp_packet_clone(const struct dp_packet *);
 105 struct dp_packet *dp_packet_clone_with_headroom(const struct dp_packet *,
 106                                                 size_t headroom);
 107 struct dp_packet *dp_packet_clone_data(const void *, size_t);
 108 struct dp_packet *dp_packet_clone_data_with_headroom(const void *, size_t,
 109                                                      size_t headroom);
 110 static inline void dp_packet_delete(struct dp_packet *);
 111
 112 static inline void *dp_packet_at(const struct dp_packet *, size_t offset,
 113                                  size_t size);
 114 static inline void *dp_packet_at_assert(const struct dp_packet *,
 115                                         size_t offset, size_t size);
 116 static inline void *dp_packet_tail(const struct dp_packet *);
 117 static inline void *dp_packet_end(const struct dp_packet *);
 118
 119 void *dp_packet_put_uninit(struct dp_packet *, size_t);
 120 void *dp_packet_put_zeros(struct dp_packet *, size_t);
 121 void *dp_packet_put(struct dp_packet *, const void *, size_t);
 122 char *dp_packet_put_hex(struct dp_packet *, const char *s, size_t *n);
 123 void dp_packet_reserve(struct dp_packet *, size_t);
 124 void dp_packet_reserve_with_tailroom(struct dp_packet *, size_t headroom,
 125                                      size_t tailroom);
 126 void *dp_packet_push_uninit(struct dp_packet *, size_t);
 127 void *dp_packet_push_zeros(struct dp_packet *, size_t);
 128 void *dp_packet_push(struct dp_packet *, const void *, size_t);
 129
 130 static inline size_t dp_packet_headroom(const struct dp_packet *);
 131 static inline size_t dp_packet_tailroom(const struct dp_packet *);
 132 void dp_packet_prealloc_headroom(struct dp_packet *, size_t);
 133 void dp_packet_prealloc_tailroom(struct dp_packet *, size_t);
 134 void dp_packet_shift(struct dp_packet *, int);
 135
 136 static inline void dp_packet_clear(struct dp_packet *);
 137 static inline void *dp_packet_pull(struct dp_packet *, size_t);
 138 static inline void *dp_packet_try_pull(struct dp_packet *, size_t);
 139
 140 void *dp_packet_steal_data(struct dp_packet *);
 141
 142 char *dp_packet_to_string(const struct dp_packet *, size_t maxbytes);
 143 static inline bool dp_packet_equal(const struct dp_packet *,
 144                                    const struct dp_packet *);
 145
 146 \f
 147 /* Frees memory that 'b' points to, as well as 'b' itself. */
 148 static inline void
 149 dp_packet_delete(struct dp_packet *b)
 150 {
 151     if (b) {
 152         if (b->source == DPBUF_DPDK) {
 153             /* If this dp_packet was allocated by DPDK it must have been
 154              * created as a dp_packet */
 155             free_dpdk_buf((struct dp_packet*) b);
 156             return;
 157         }
 158
 159         dp_packet_uninit(b);
 160         free(b);
 161     }
 162 }
 163
 164 /* If 'b' contains at least 'offset + size' bytes of data, returns a pointer to
 165  * byte 'offset'.  Otherwise, returns a null pointer. */
 166 static inline void *
 167 dp_packet_at(const struct dp_packet *b, size_t offset, size_t size)
 168 {
 169     return offset + size <= dp_packet_size(b)
 170            ? (char *) dp_packet_data(b) + offset
 171            : NULL;
 172 }
 173
 174 /* Returns a pointer to byte 'offset' in 'b', which must contain at least
 175  * 'offset + size' bytes of data. */
 176 static inline void *
 177 dp_packet_at_assert(const struct dp_packet *b, size_t offset, size_t size)
 178 {
 179     ovs_assert(offset + size <= dp_packet_size(b));
 180     return ((char *) dp_packet_data(b)) + offset;
 181 }
 182
 183 /* Returns a pointer to byte following the last byte of data in use in 'b'. */
 184 static inline void *
 185 dp_packet_tail(const struct dp_packet *b)
 186 {
 187     return (char *) dp_packet_data(b) + dp_packet_size(b);
 188 }
 189
 190 /* Returns a pointer to byte following the last byte allocated for use (but
 191  * not necessarily in use) in 'b'. */
 192 static inline void *
 193 dp_packet_end(const struct dp_packet *b)
 194 {
 195     return (char *) dp_packet_base(b) + dp_packet_get_allocated(b);
 196 }
 197
 198 /* Returns the number of bytes of headroom in 'b', that is, the number of bytes
 199  * of unused space in dp_packet 'b' before the data that is in use.  (Most
 200  * commonly, the data in a dp_packet is at its beginning, and thus the
 201  * dp_packet's headroom is 0.) */
 202 static inline size_t
 203 dp_packet_headroom(const struct dp_packet *b)
 204 {
 205     return (char *) dp_packet_data(b) - (char *) dp_packet_base(b);
 206 }
 207
 208 /* Returns the number of bytes that may be appended to the tail end of
 209  * dp_packet 'b' before the dp_packet must be reallocated. */
 210 static inline size_t
 211 dp_packet_tailroom(const struct dp_packet *b)
 212 {
 213     return (char *) dp_packet_end(b) - (char *) dp_packet_tail(b);
 214 }
 215
 216 /* Clears any data from 'b'. */
 217 static inline void
 218 dp_packet_clear(struct dp_packet *b)
 219 {
 220     dp_packet_set_data(b, dp_packet_base(b));
 221     dp_packet_set_size(b, 0);
 222 }
 223
 224 /* Removes 'size' bytes from the head end of 'b', which must contain at least
 225  * 'size' bytes of data.  Returns the first byte of data removed. */
 226 static inline void *
 227 dp_packet_pull(struct dp_packet *b, size_t size)
 228 {
 229     void *data = dp_packet_data(b);
 230     ovs_assert(dp_packet_size(b) - dp_packet_l2_pad_size(b) >= size);
 231     dp_packet_set_data(b, (char *) dp_packet_data(b) + size);
 232     dp_packet_set_size(b, dp_packet_size(b) - size);
 233     return data;
 234 }
 235
 236 /* If 'b' has at least 'size' bytes of data, removes that many bytes from the
 237  * head end of 'b' and returns the first byte removed.  Otherwise, returns a
 238  * null pointer without modifying 'b'. */
 239 static inline void *
 240 dp_packet_try_pull(struct dp_packet *b, size_t size)
 241 {
 242     return dp_packet_size(b) - dp_packet_l2_pad_size(b) >= size
 243         ? dp_packet_pull(b, size) : NULL;
 244 }
 245
 246 static inline bool
 247 dp_packet_equal(const struct dp_packet *a, const struct dp_packet *b)
 248 {
 249     return dp_packet_size(a) == dp_packet_size(b) &&
 250            !memcmp(dp_packet_data(a), dp_packet_data(b), dp_packet_size(a));
 251 }
 252
 253 /* Get the start of the Ethernet frame.  'l3_ofs' marks the end of the l2
 254  * headers, so return NULL if it is not set. */
 255 static inline void *
 256 dp_packet_l2(const struct dp_packet *b)
 257 {
 258     return (b->l3_ofs != UINT16_MAX) ? dp_packet_data(b) : NULL;
 259 }
 260
 261 /* Resets all layer offsets.  'l3' offset must be set before 'l2' can be
 262  * retrieved. */
 263 static inline void
 264 dp_packet_reset_offsets(struct dp_packet *b)
 265 {
 266     b->l2_pad_size = 0;
 267     b->l2_5_ofs = UINT16_MAX;
 268     b->l3_ofs = UINT16_MAX;
 269     b->l4_ofs = UINT16_MAX;
 270 }
 271
 272 static inline uint8_t
 273 dp_packet_l2_pad_size(const struct dp_packet *b)
 274 {
 275     return b->l2_pad_size;
 276 }
 277
 278 static inline void
 279 dp_packet_set_l2_pad_size(struct dp_packet *b, uint8_t pad_size)
 280 {
 281     ovs_assert(pad_size <= dp_packet_size(b));
 282     b->l2_pad_size = pad_size;
 283 }
 284
 285 static inline void *
 286 dp_packet_l2_5(const struct dp_packet *b)
 287 {
 288     return b->l2_5_ofs != UINT16_MAX
 289            ? (char *) dp_packet_data(b) + b->l2_5_ofs
 290            : NULL;
 291 }
 292
 293 static inline void
 294 dp_packet_set_l2_5(struct dp_packet *b, void *l2_5)
 295 {
 296     b->l2_5_ofs = l2_5
 297                   ? (char *) l2_5 - (char *) dp_packet_data(b)
 298                   : UINT16_MAX;
 299 }
 300
 301 static inline void *
 302 dp_packet_l3(const struct dp_packet *b)
 303 {
 304     return b->l3_ofs != UINT16_MAX
 305            ? (char *) dp_packet_data(b) + b->l3_ofs
 306            : NULL;
 307 }
 308
 309 static inline void
 310 dp_packet_set_l3(struct dp_packet *b, void *l3)
 311 {
 312     b->l3_ofs = l3 ? (char *) l3 - (char *) dp_packet_data(b) : UINT16_MAX;
 313 }
 314
 315 static inline void *
 316 dp_packet_l4(const struct dp_packet *b)
 317 {
 318     return b->l4_ofs != UINT16_MAX
 319            ? (char *) dp_packet_data(b) + b->l4_ofs
 320            : NULL;
 321 }
 322
 323 static inline void
 324 dp_packet_set_l4(struct dp_packet *b, void *l4)
 325 {
 326     b->l4_ofs = l4 ? (char *) l4 - (char *) dp_packet_data(b) : UINT16_MAX;
 327 }
 328
 329 static inline size_t
 330 dp_packet_l4_size(const struct dp_packet *b)
 331 {
 332     return b->l4_ofs != UINT16_MAX
 333         ? (const char *)dp_packet_tail(b) - (const char *)dp_packet_l4(b)
 334         - dp_packet_l2_pad_size(b)
 335         : 0;
 336 }
 337
 338 static inline const void *
 339 dp_packet_get_tcp_payload(const struct dp_packet *b)
 340 {
 341     size_t l4_size = dp_packet_l4_size(b);
 342
 343     if (OVS_LIKELY(l4_size >= TCP_HEADER_LEN)) {
 344         struct tcp_header *tcp = dp_packet_l4(b);
 345         int tcp_len = TCP_OFFSET(tcp->tcp_ctl) * 4;
 346
 347         if (OVS_LIKELY(tcp_len >= TCP_HEADER_LEN && tcp_len <= l4_size)) {
 348             return (const char *)tcp + tcp_len;
 349         }
 350     }
 351     return NULL;
 352 }
 353
 354 static inline const void *
 355 dp_packet_get_udp_payload(const struct dp_packet *b)
 356 {
 357     return OVS_LIKELY(dp_packet_l4_size(b) >= UDP_HEADER_LEN)
 358         ? (const char *)dp_packet_l4(b) + UDP_HEADER_LEN : NULL;
 359 }
 360
 361 static inline const void *
 362 dp_packet_get_sctp_payload(const struct dp_packet *b)
 363 {
 364     return OVS_LIKELY(dp_packet_l4_size(b) >= SCTP_HEADER_LEN)
 365         ? (const char *)dp_packet_l4(b) + SCTP_HEADER_LEN : NULL;
 366 }
 367
 368 static inline const void *
 369 dp_packet_get_icmp_payload(const struct dp_packet *b)
 370 {
 371     return OVS_LIKELY(dp_packet_l4_size(b) >= ICMP_HEADER_LEN)
 372         ? (const char *)dp_packet_l4(b) + ICMP_HEADER_LEN : NULL;
 373 }
 374
 375 static inline const void *
 376 dp_packet_get_nd_payload(const struct dp_packet *b)
 377 {
 378     return OVS_LIKELY(dp_packet_l4_size(b) >= ND_MSG_LEN)
 379         ? (const char *)dp_packet_l4(b) + ND_MSG_LEN : NULL;
 380 }
 381
 382 #ifdef DPDK_NETDEV
 383 BUILD_ASSERT_DECL(offsetof(struct dp_packet, mbuf) == 0);
 384
 385 static inline void *
 386 dp_packet_base(const struct dp_packet *b)
 387 {
 388     return b->mbuf.buf_addr;
 389 }
 390
 391 static inline void
 392 dp_packet_set_base(struct dp_packet *b, void *d)
 393 {
 394     b->mbuf.buf_addr = d;
 395 }
 396
 397 static inline uint32_t
 398 dp_packet_size(const struct dp_packet *b)
 399 {
 400     return b->mbuf.pkt_len;
 401 }
 402
 403 static inline void
 404 dp_packet_set_size(struct dp_packet *b, uint32_t v)
 405 {
 406     /* netdev-dpdk does not currently support segmentation; consequently, for
 407      * all intents and purposes, 'data_len' (16 bit) and 'pkt_len' (32 bit) may
 408      * be used interchangably.
 409      *
 410      * On the datapath, it is expected that the size of packets
 411      * (and thus 'v') will always be <= UINT16_MAX; this means that there is no
 412      * loss of accuracy in assigning 'v' to 'data_len'.
 413      */
 414     b->mbuf.data_len = (uint16_t)v;  /* Current seg length. */
 415     b->mbuf.pkt_len = v;             /* Total length of all segments linked to
 416                                       * this segment. */
 417 }
 418
 419 static inline uint16_t
 420 __packet_data(const struct dp_packet *b)
 421 {
 422     return b->mbuf.data_off;
 423 }
 424
 425 static inline void
 426 __packet_set_data(struct dp_packet *b, uint16_t v)
 427 {
 428     b->mbuf.data_off = v;
 429 }
 430
 431 static inline uint16_t
 432 dp_packet_get_allocated(const struct dp_packet *b)
 433 {
 434     return b->mbuf.buf_len;
 435 }
 436
 437 static inline void
 438 dp_packet_set_allocated(struct dp_packet *b, uint16_t s)
 439 {
 440     b->mbuf.buf_len = s;
 441 }
 442 #else
 443 static inline void *
 444 dp_packet_base(const struct dp_packet *b)
 445 {
 446     return b->base_;
 447 }
 448
 449 static inline void
 450 dp_packet_set_base(struct dp_packet *b, void *d)
 451 {
 452     b->base_ = d;
 453 }
 454
 455 static inline uint32_t
 456 dp_packet_size(const struct dp_packet *b)
 457 {
 458     return b->size_;
 459 }
 460
 461 static inline void
 462 dp_packet_set_size(struct dp_packet *b, uint32_t v)
 463 {
 464     b->size_ = v;
 465 }
 466
 467 static inline uint16_t
 468 __packet_data(const struct dp_packet *b)
 469 {
 470     return b->data_ofs;
 471 }
 472
 473 static inline void
 474 __packet_set_data(struct dp_packet *b, uint16_t v)
 475 {
 476     b->data_ofs = v;
 477 }
 478
 479 static inline uint16_t
 480 dp_packet_get_allocated(const struct dp_packet *b)
 481 {
 482     return b->allocated_;
 483 }
 484
 485 static inline void
 486 dp_packet_set_allocated(struct dp_packet *b, uint16_t s)
 487 {
 488     b->allocated_ = s;
 489 }
 490 #endif
 491
 492 static inline void *
 493 dp_packet_data(const struct dp_packet *b)
 494 {
 495     return __packet_data(b) != UINT16_MAX
 496            ? (char *) dp_packet_base(b) + __packet_data(b) : NULL;
 497 }
 498
 499 static inline void
 500 dp_packet_set_data(struct dp_packet *b, void *data)
 501 {
 502     if (data) {
 503         __packet_set_data(b, (char *) data - (char *) dp_packet_base(b));
 504     } else {
 505         __packet_set_data(b, UINT16_MAX);
 506     }
 507 }
 508
 509 static inline void
 510 dp_packet_reset_packet(struct dp_packet *b, int off)
 511 {
 512     dp_packet_set_size(b, dp_packet_size(b) - off);
 513     dp_packet_set_data(b, ((unsigned char *) dp_packet_data(b) + off));
 514     b->l2_5_ofs = b->l3_ofs = b->l4_ofs = UINT16_MAX;
 515 }
 516
 517 static inline uint32_t
 518 dp_packet_get_rss_hash(struct dp_packet *p)
 519 {
 520 #ifdef DPDK_NETDEV
 521     return p->mbuf.hash.rss;
 522 #else
 523     return p->rss_hash;
 524 #endif
 525 }
 526
 527 static inline void
 528 dp_packet_set_rss_hash(struct dp_packet *p, uint32_t hash)
 529 {
 530 #ifdef DPDK_NETDEV
 531     p->mbuf.hash.rss = hash;
 532 #else
 533     p->rss_hash = hash;
 534 #endif
 535 }
 536
 537 #ifdef  __cplusplus
 538 }
 539 #endif
 540
 541 #endif /* dp-packet.h */