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41 * The mbuf library provides the ability to create and destroy buffers
42 * that may be used by the RTE application to store message
43 * buffers. The message buffers are stored in a mempool, using the
44 * RTE mempool library.
46 * This library provide an API to allocate/free mbufs, manipulate
47 * control message buffer (ctrlmbuf), which are generic message
48 * buffers, and packet buffers (pktmbuf), which are used to carry
51 * To understand the concepts of packet buffers or mbufs, you
52 * should read "TCP/IP Illustrated, Volume 2: The Implementation,
53 * Addison-Wesley, 1995, ISBN 0-201-63354-X from Richard Stevens"
54 * http://www.kohala.com/start/tcpipiv2.html
56 * The main modification of this implementation is the use of mbuf for
57 * transports other than packets. mbufs can have other types.
61 #include <rte_mempool.h>
62 #include <rte_atomic.h>
63 #include <rte_prefetch.h>
64 #include <rte_branch_prediction.h>
71 * A control message buffer.
74 void *data; /**< Pointer to data. */
75 uint32_t data_len; /**< Length of data. */
80 * Packet Offload Features Flags. It also carry packet type information.
81 * Critical resources. Both rx/tx shared these bits. Be cautious on any change
83 #define PKT_RX_VLAN_PKT 0x0001 /**< RX packet is a 802.1q VLAN packet. */
84 #define PKT_RX_RSS_HASH 0x0002 /**< RX packet with RSS hash result. */
85 #define PKT_RX_FDIR 0x0004 /**< RX packet with FDIR infos. */
86 #define PKT_RX_L4_CKSUM_BAD 0x0008 /**< L4 cksum of RX pkt. is not OK. */
87 #define PKT_RX_IP_CKSUM_BAD 0x0010 /**< IP cksum of RX pkt. is not OK. */
88 #define PKT_RX_IPV4_HDR 0x0020 /**< RX packet with IPv4 header. */
89 #define PKT_RX_IPV4_HDR_EXT 0x0040 /**< RX packet with extended IPv4 header. */
90 #define PKT_RX_IPV6_HDR 0x0080 /**< RX packet with IPv6 header. */
91 #define PKT_RX_IPV6_HDR_EXT 0x0100 /**< RX packet with extended IPv6 header. */
92 #define PKT_RX_IEEE1588_PTP 0x0200 /**< RX IEEE1588 L2 Ethernet PT Packet. */
93 #define PKT_RX_IEEE1588_TMST 0x0400 /**< RX IEEE1588 L2/L4 timestamped packet.*/
95 #define PKT_TX_VLAN_PKT 0x0800 /**< TX packet is a 802.1q VLAN packet. */
96 #define PKT_TX_IP_CKSUM 0x1000 /**< IP cksum of TX pkt. computed by NIC. */
98 * Bit 14~13 used for L4 packet type with checksum enabled.
104 #define PKT_TX_L4_MASK 0x6000 /**< Mask bits for L4 checksum offload request. */
105 #define PKT_TX_L4_NO_CKSUM 0x0000 /**< Disable L4 cksum of TX pkt. */
106 #define PKT_TX_TCP_CKSUM 0x2000 /**< TCP cksum of TX pkt. computed by NIC. */
107 #define PKT_TX_SCTP_CKSUM 0x4000 /**< SCTP cksum of TX pkt. computed by NIC. */
108 #define PKT_TX_UDP_CKSUM 0x6000 /**< UDP cksum of TX pkt. computed by NIC. */
110 #define PKT_TX_IEEE1588_TMST 0x8000 /**< TX IEEE1588 packet to timestamp. */
113 * Bit Mask to indicate what bits required for building TX context
115 #define PKT_TX_OFFLOAD_MASK (PKT_TX_VLAN_PKT | PKT_TX_IP_CKSUM | PKT_TX_L4_MASK)
117 /** Offload features */
118 union rte_vlan_macip {
121 uint16_t l3_len:9; /**< L3 (IP) Header Length. */
122 uint16_t l2_len:7; /**< L2 (MAC) Header Length. */
124 /**< VLAN Tag Control Identifier (CPU order). */
129 * Compare mask for vlan_macip_len.data,
130 * should be in sync with rte_vlan_macip.f layout.
132 #define TX_VLAN_CMP_MASK 0xFFFF0000 /**< VLAN length - 16-bits. */
133 #define TX_MAC_LEN_CMP_MASK 0x0000FE00 /**< MAC length - 7-bits. */
134 #define TX_IP_LEN_CMP_MASK 0x000001FF /**< IP length - 9-bits. */
135 /**< MAC+IP length. */
136 #define TX_MACIP_LEN_CMP_MASK (TX_MAC_LEN_CMP_MASK | TX_IP_LEN_CMP_MASK)
139 * A packet message buffer.
142 /* valid for any segment */
143 struct rte_mbuf *next; /**< Next segment of scattered packet. */
144 void* data; /**< Start address of data in segment buffer. */
145 uint16_t data_len; /**< Amount of data in segment buffer. */
147 /* these fields are valid for first segment only */
148 uint8_t nb_segs; /**< Number of segments. */
149 uint8_t in_port; /**< Input port. */
150 uint32_t pkt_len; /**< Total pkt len: sum of all segment data_len. */
152 /* offload features */
153 union rte_vlan_macip vlan_macip;
155 uint32_t rss; /**< RSS hash result if RSS enabled */
159 } fdir; /**< Filter identifier if FDIR enabled */
160 uint32_t sched; /**< Hierarchical scheduler */
161 } hash; /**< hash information */
165 * This enum indicates the mbuf type.
168 RTE_MBUF_CTRL, /**< Control mbuf. */
169 RTE_MBUF_PKT, /**< Packet mbuf. */
173 * The generic rte_mbuf, containing a packet mbuf or a control mbuf.
176 struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */
177 void *buf_addr; /**< Virtual address of segment buffer. */
178 phys_addr_t buf_physaddr; /**< Physical address of segment buffer. */
179 uint16_t buf_len; /**< Length of segment buffer. */
180 #ifdef RTE_MBUF_SCATTER_GATHER
182 * 16-bit Reference counter.
183 * It should only be accessed using the following functions:
184 * rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(), and
185 * rte_mbuf_refcnt_set(). The functionality of these functions (atomic,
186 * or non-atomic) is controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC
190 rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */
191 uint16_t refcnt; /**< Non-atomically accessed refcnt */
194 uint16_t refcnt_reserved; /**< Do not use this field */
196 uint8_t type; /**< Type of mbuf. */
197 uint8_t reserved; /**< Unused field. Required for padding. */
198 uint16_t ol_flags; /**< Offload features. */
201 struct rte_ctrlmbuf ctrl;
202 struct rte_pktmbuf pkt;
204 } __rte_cache_aligned;
207 * Given the buf_addr returns the pointer to corresponding mbuf.
209 #define RTE_MBUF_FROM_BADDR(ba) (((struct rte_mbuf *)(ba)) - 1)
212 * Given the pointer to mbuf returns an address where it's buf_addr
215 #define RTE_MBUF_TO_BADDR(mb) (((struct rte_mbuf *)(mb)) + 1)
218 * Returns TRUE if given mbuf is indirect, or FALSE otherwise.
220 #define RTE_MBUF_INDIRECT(mb) (RTE_MBUF_FROM_BADDR((mb)->buf_addr) != (mb))
223 * Returns TRUE if given mbuf is direct, or FALSE otherwise.
225 #define RTE_MBUF_DIRECT(mb) (RTE_MBUF_FROM_BADDR((mb)->buf_addr) == (mb))
229 * Private data in case of pktmbuf pool.
231 * A structure that contains some pktmbuf_pool-specific data that are
232 * appended after the mempool structure (in private data).
234 struct rte_pktmbuf_pool_private {
235 uint16_t mbuf_data_room_size; /**< Size of data space in each mbuf.*/
238 #ifdef RTE_LIBRTE_MBUF_DEBUG
240 /** check mbuf type in debug mode */
241 #define __rte_mbuf_sanity_check(m, t, is_h) rte_mbuf_sanity_check(m, t, is_h)
243 /** check mbuf type in debug mode if mbuf pointer is not null */
244 #define __rte_mbuf_sanity_check_raw(m, t, is_h) do { \
246 rte_mbuf_sanity_check(m, t, is_h); \
249 /** MBUF asserts in debug mode */
250 #define RTE_MBUF_ASSERT(exp) \
252 rte_panic("line%d\tassert \"" #exp "\" failed\n", __LINE__); \
255 #else /* RTE_LIBRTE_MBUF_DEBUG */
257 /** check mbuf type in debug mode */
258 #define __rte_mbuf_sanity_check(m, t, is_h) do { } while(0)
260 /** check mbuf type in debug mode if mbuf pointer is not null */
261 #define __rte_mbuf_sanity_check_raw(m, t, is_h) do { } while(0)
263 /** MBUF asserts in debug mode */
264 #define RTE_MBUF_ASSERT(exp) do { } while(0)
266 #endif /* RTE_LIBRTE_MBUF_DEBUG */
268 #ifdef RTE_MBUF_SCATTER_GATHER
269 #ifdef RTE_MBUF_REFCNT_ATOMIC
272 * Adds given value to an mbuf's refcnt and returns its new value.
276 * Value to add/subtract
280 static inline uint16_t
281 rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value)
283 return (uint16_t)(rte_atomic16_add_return(&m->refcnt_atomic, value));
287 * Reads the value of an mbuf's refcnt.
291 * Reference count number.
293 static inline uint16_t
294 rte_mbuf_refcnt_read(const struct rte_mbuf *m)
296 return (uint16_t)(rte_atomic16_read(&m->refcnt_atomic));
300 * Sets an mbuf's refcnt to a defined value.
307 rte_mbuf_refcnt_set(struct rte_mbuf *m, uint16_t new_value)
309 rte_atomic16_set(&m->refcnt_atomic, new_value);
312 #else /* ! RTE_MBUF_REFCNT_ATOMIC */
315 * Adds given value to an mbuf's refcnt and returns its new value.
317 static inline uint16_t
318 rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value)
320 m->refcnt = (uint16_t)(m->refcnt + value);
325 * Reads the value of an mbuf's refcnt.
327 static inline uint16_t
328 rte_mbuf_refcnt_read(const struct rte_mbuf *m)
334 * Sets an mbuf's refcnt to the defined value.
337 rte_mbuf_refcnt_set(struct rte_mbuf *m, uint16_t new_value)
339 m->refcnt = new_value;
342 #endif /* RTE_MBUF_REFCNT_ATOMIC */
345 #define RTE_MBUF_PREFETCH_TO_FREE(m) do { \
350 #else /* ! RTE_MBUF_SCATTER_GATHER */
353 #define RTE_MBUF_PREFETCH_TO_FREE(m) do { } while(0)
355 #define rte_mbuf_refcnt_set(m,v) do { } while(0)
357 #endif /* RTE_MBUF_SCATTER_GATHER */
361 * Sanity checks on an mbuf.
363 * Check the consistency of the given mbuf. The function will cause a
364 * panic if corruption is detected.
367 * The mbuf to be checked.
369 * The expected type of the mbuf.
371 * True if the mbuf is a packet header, false if it is a sub-segment
372 * of a packet (in this case, some fields like nb_segs are not checked)
375 rte_mbuf_sanity_check(const struct rte_mbuf *m, enum rte_mbuf_type t,
379 * @internal Allocate a new mbuf from mempool *mp*.
380 * The use of that function is reserved for RTE internal needs.
381 * Please use either rte_ctrlmbuf_alloc() or rte_pktmbuf_alloc().
384 * The mempool from which mbuf is allocated.
386 * - The pointer to the new mbuf on success.
387 * - NULL if allocation failed.
389 static inline struct rte_mbuf *__rte_mbuf_raw_alloc(struct rte_mempool *mp)
393 if (rte_mempool_get(mp, &mb) < 0)
395 m = (struct rte_mbuf *)mb;
396 #ifdef RTE_MBUF_SCATTER_GATHER
397 RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(m) == 0);
398 rte_mbuf_refcnt_set(m, 1);
399 #endif /* RTE_MBUF_SCATTER_GATHER */
404 * @internal Put mbuf back into its original mempool.
405 * The use of that function is reserved for RTE internal needs.
406 * Please use either rte_ctrlmbuf_free() or rte_pktmbuf_free().
409 * The mbuf to be freed.
411 static inline void __attribute__((always_inline))
412 __rte_mbuf_raw_free(struct rte_mbuf *m)
414 #ifdef RTE_MBUF_SCATTER_GATHER
415 RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(m) == 0);
416 #endif /* RTE_MBUF_SCATTER_GATHER */
417 rte_mempool_put(m->pool, m);
420 /* Operations on ctrl mbuf */
423 * The control mbuf constructor.
425 * This function initializes some fields in an mbuf structure that are
426 * not modified by the user once created (mbuf type, origin pool, buffer
427 * start address, and so on). This function is given as a callback function
428 * to rte_mempool_create() at pool creation time.
431 * The mempool from which the mbuf is allocated.
433 * A pointer that can be used by the user to retrieve useful information
434 * for mbuf initialization. This pointer comes from the ``init_arg``
435 * parameter of rte_mempool_create().
437 * The mbuf to initialize.
439 * The index of the mbuf in the pool table.
441 void rte_ctrlmbuf_init(struct rte_mempool *mp, void *opaque_arg,
442 void *m, unsigned i);
445 * Allocate a new mbuf (type is ctrl) from mempool *mp*.
447 * This new mbuf is initialized with data pointing to the beginning of
448 * buffer, and with a length of zero.
451 * The mempool from which the mbuf is allocated.
453 * - The pointer to the new mbuf on success.
454 * - NULL if allocation failed.
456 static inline struct rte_mbuf *rte_ctrlmbuf_alloc(struct rte_mempool *mp)
459 if ((m = __rte_mbuf_raw_alloc(mp)) != NULL) {
460 m->ctrl.data = m->buf_addr;
461 m->ctrl.data_len = 0;
462 __rte_mbuf_sanity_check(m, RTE_MBUF_CTRL, 0);
468 * Free a control mbuf back into its original mempool.
471 * The control mbuf to be freed.
473 static inline void rte_ctrlmbuf_free(struct rte_mbuf *m)
475 __rte_mbuf_sanity_check(m, RTE_MBUF_CTRL, 0);
476 #ifdef RTE_MBUF_SCATTER_GATHER
477 if (rte_mbuf_refcnt_update(m, -1) == 0)
478 #endif /* RTE_MBUF_SCATTER_GATHER */
479 __rte_mbuf_raw_free(m);
483 * A macro that returns the pointer to the carried data.
485 * The value that can be read or assigned.
490 #define rte_ctrlmbuf_data(m) ((m)->ctrl.data)
493 * A macro that returns the length of the carried data.
495 * The value that can be read or assigned.
500 #define rte_ctrlmbuf_len(m) ((m)->ctrl.data_len)
502 /* Operations on pkt mbuf */
505 * The packet mbuf constructor.
507 * This function initializes some fields in the mbuf structure that are not
508 * modified by the user once created (mbuf type, origin pool, buffer start
509 * address, and so on). This function is given as a callback function to
510 * rte_mempool_create() at pool creation time.
513 * The mempool from which mbufs originate.
515 * A pointer that can be used by the user to retrieve useful information
516 * for mbuf initialization. This pointer comes from the ``init_arg``
517 * parameter of rte_mempool_create().
519 * The mbuf to initialize.
521 * The index of the mbuf in the pool table.
523 void rte_pktmbuf_init(struct rte_mempool *mp, void *opaque_arg,
524 void *m, unsigned i);
528 * A packet mbuf pool constructor.
530 * This function initializes the mempool private data in the case of a
531 * pktmbuf pool. This private data is needed by the driver. The
532 * function is given as a callback function to rte_mempool_create() at
533 * pool creation. It can be extended by the user, for example, to
534 * provide another packet size.
537 * The mempool from which mbufs originate.
539 * A pointer that can be used by the user to retrieve useful information
540 * for mbuf initialization. This pointer comes from the ``init_arg``
541 * parameter of rte_mempool_create().
543 void rte_pktmbuf_pool_init(struct rte_mempool *mp, void *opaque_arg);
546 * Reset the fields of a packet mbuf to their default values.
548 * The given mbuf must have only one segment.
551 * The packet mbuf to be resetted.
553 static inline void rte_pktmbuf_reset(struct rte_mbuf *m)
559 m->pkt.vlan_macip.data = 0;
561 m->pkt.in_port = 0xff;
564 buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
565 RTE_PKTMBUF_HEADROOM : m->buf_len;
566 m->pkt.data = (char*) m->buf_addr + buf_ofs;
569 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
573 * Allocate a new mbuf (type is pkt) from a mempool.
575 * This new mbuf contains one segment, which has a length of 0. The pointer
576 * to data is initialized to have some bytes of headroom in the buffer
577 * (if buffer size allows).
580 * The mempool from which the mbuf is allocated.
582 * - The pointer to the new mbuf on success.
583 * - NULL if allocation failed.
585 static inline struct rte_mbuf *rte_pktmbuf_alloc(struct rte_mempool *mp)
588 if ((m = __rte_mbuf_raw_alloc(mp)) != NULL)
589 rte_pktmbuf_reset(m);
593 #ifdef RTE_MBUF_SCATTER_GATHER
596 * Attach packet mbuf to another packet mbuf.
597 * After attachment we refer the mbuf we attached as 'indirect',
598 * while mbuf we attached to as 'direct'.
599 * Right now, not supported:
600 * - attachment to indirect mbuf (e.g. - md has to be direct).
601 * - attachment for already indirect mbuf (e.g. - mi has to be direct).
602 * - mbuf we trying to attach (mi) is used by someone else
603 * e.g. it's reference counter is greater then 1.
606 * The indirect packet mbuf.
608 * The direct packet mbuf.
611 static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *md)
613 RTE_MBUF_ASSERT(RTE_MBUF_DIRECT(md) &&
614 RTE_MBUF_DIRECT(mi) &&
615 rte_mbuf_refcnt_read(mi) == 1);
617 rte_mbuf_refcnt_update(md, 1);
618 mi->buf_physaddr = md->buf_physaddr;
619 mi->buf_addr = md->buf_addr;
620 mi->buf_len = md->buf_len;
625 mi->pkt.pkt_len = mi->pkt.data_len;
628 __rte_mbuf_sanity_check(mi, RTE_MBUF_PKT, 1);
629 __rte_mbuf_sanity_check(md, RTE_MBUF_PKT, 0);
633 * Detach an indirect packet mbuf -
634 * - restore original mbuf address and length values.
635 * - reset pktmbuf data and data_len to their default values.
636 * All other fields of the given packet mbuf will be left intact.
639 * The indirect attached packet mbuf.
642 static inline void rte_pktmbuf_detach(struct rte_mbuf *m)
644 const struct rte_mempool *mp = m->pool;
645 void *buf = RTE_MBUF_TO_BADDR(m);
647 uint32_t buf_len = mp->elt_size - sizeof(*m);
648 m->buf_physaddr = rte_mempool_virt2phy(mp, m) + sizeof (*m);
651 m->buf_len = (uint16_t)buf_len;
653 buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
654 RTE_PKTMBUF_HEADROOM : m->buf_len;
655 m->pkt.data = (char*) m->buf_addr + buf_ofs;
660 #endif /* RTE_MBUF_SCATTER_GATHER */
663 static inline struct rte_mbuf* __attribute__((always_inline))
664 __rte_pktmbuf_prefree_seg(struct rte_mbuf *m)
666 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 0);
668 #ifdef RTE_MBUF_SCATTER_GATHER
669 if (likely (rte_mbuf_refcnt_read(m) == 1) ||
670 likely (rte_mbuf_refcnt_update(m, -1) == 0)) {
671 struct rte_mbuf *md = RTE_MBUF_FROM_BADDR(m->buf_addr);
673 rte_mbuf_refcnt_set(m, 0);
675 /* if this is an indirect mbuf, then
677 * - free attached mbuf segment
679 if (unlikely (md != m)) {
680 rte_pktmbuf_detach(m);
681 if (rte_mbuf_refcnt_update(md, -1) == 0)
682 __rte_mbuf_raw_free(md);
686 #ifdef RTE_MBUF_SCATTER_GATHER
693 * Free a segment of a packet mbuf into its original mempool.
695 * Free an mbuf, without parsing other segments in case of chained
699 * The packet mbuf segment to be freed.
701 static inline void __attribute__((always_inline))
702 rte_pktmbuf_free_seg(struct rte_mbuf *m)
704 if (likely(NULL != (m = __rte_pktmbuf_prefree_seg(m))))
705 __rte_mbuf_raw_free(m);
709 * Free a packet mbuf back into its original mempool.
711 * Free an mbuf, and all its segments in case of chained buffers. Each
712 * segment is added back into its original mempool.
715 * The packet mbuf to be freed.
717 static inline void rte_pktmbuf_free(struct rte_mbuf *m)
719 struct rte_mbuf *m_next;
721 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
724 m_next = m->pkt.next;
725 rte_pktmbuf_free_seg(m);
730 #ifdef RTE_MBUF_SCATTER_GATHER
733 * Creates a "clone" of the given packet mbuf.
735 * Walks through all segments of the given packet mbuf, and for each of them:
736 * - Creates a new packet mbuf from the given pool.
737 * - Attaches newly created mbuf to the segment.
738 * Then updates pkt_len and nb_segs of the "clone" packet mbuf to match values
739 * from the original packet mbuf.
742 * The packet mbuf to be cloned.
744 * The mempool from which the "clone" mbufs are allocated.
746 * - The pointer to the new "clone" mbuf on success.
747 * - NULL if allocation fails.
749 static inline struct rte_mbuf *rte_pktmbuf_clone(struct rte_mbuf *md,
750 struct rte_mempool *mp)
752 struct rte_mbuf *mc, *mi, **prev;
756 if (unlikely ((mc = rte_pktmbuf_alloc(mp)) == NULL))
760 prev = &mi->pkt.next;
761 pktlen = md->pkt.pkt_len;
766 rte_pktmbuf_attach(mi, md);
768 prev = &mi->pkt.next;
769 } while ((md = md->pkt.next) != NULL &&
770 (mi = rte_pktmbuf_alloc(mp)) != NULL);
773 mc->pkt.nb_segs = nseg;
774 mc->pkt.pkt_len = pktlen;
776 /* Allocation of new indirect segment failed */
777 if (unlikely (mi == NULL)) {
778 rte_pktmbuf_free(mc);
782 __rte_mbuf_sanity_check(mc, RTE_MBUF_PKT, 1);
787 * Adds given value to the refcnt of all packet mbuf segments.
789 * Walks through all segments of given packet mbuf and for each of them
790 * invokes rte_mbuf_refcnt_update().
793 * The packet mbuf whose refcnt to be updated.
795 * The value to add to the mbuf's segments refcnt.
797 static inline void rte_pktmbuf_refcnt_update(struct rte_mbuf *m, int16_t v)
799 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
802 rte_mbuf_refcnt_update(m, v);
803 } while ((m = m->pkt.next) != NULL);
806 #endif /* RTE_MBUF_SCATTER_GATHER */
809 * Get the headroom in a packet mbuf.
814 * The length of the headroom.
816 static inline uint16_t rte_pktmbuf_headroom(const struct rte_mbuf *m)
818 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
819 return (uint16_t) ((char*) m->pkt.data - (char*) m->buf_addr);
823 * Get the tailroom of a packet mbuf.
828 * The length of the tailroom.
830 static inline uint16_t rte_pktmbuf_tailroom(const struct rte_mbuf *m)
832 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
833 return (uint16_t)(m->buf_len - rte_pktmbuf_headroom(m) -
838 * Get the last segment of the packet.
843 * The last segment of the given mbuf.
845 static inline struct rte_mbuf *rte_pktmbuf_lastseg(struct rte_mbuf *m)
847 struct rte_mbuf *m2 = (struct rte_mbuf *)m;
849 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
850 while (m2->pkt.next != NULL)
856 * A macro that points to the start of the data in the mbuf.
858 * The returned pointer is cast to type t. Before using this
859 * function, the user must ensure that m_headlen(m) is large enough to
865 * The type to cast the result into.
867 #define rte_pktmbuf_mtod(m, t) ((t)((m)->pkt.data))
870 * A macro that returns the length of the packet.
872 * The value can be read or assigned.
877 #define rte_pktmbuf_pkt_len(m) ((m)->pkt.pkt_len)
880 * A macro that returns the length of the segment.
882 * The value can be read or assigned.
887 #define rte_pktmbuf_data_len(m) ((m)->pkt.data_len)
890 * Prepend len bytes to an mbuf data area.
892 * Returns a pointer to the new
893 * data start address. If there is not enough headroom in the first
894 * segment, the function will return NULL, without modifying the mbuf.
899 * The amount of data to prepend (in bytes).
901 * A pointer to the start of the newly prepended data, or
902 * NULL if there is not enough headroom space in the first segment
904 static inline char *rte_pktmbuf_prepend(struct rte_mbuf *m,
907 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
909 if (unlikely(len > rte_pktmbuf_headroom(m)))
912 m->pkt.data = (char*) m->pkt.data - len;
913 m->pkt.data_len = (uint16_t)(m->pkt.data_len + len);
914 m->pkt.pkt_len = (m->pkt.pkt_len + len);
916 return (char*) m->pkt.data;
920 * Append len bytes to an mbuf.
922 * Append len bytes to an mbuf and return a pointer to the start address
923 * of the added data. If there is not enough tailroom in the last
924 * segment, the function will return NULL, without modifying the mbuf.
929 * The amount of data to append (in bytes).
931 * A pointer to the start of the newly appended data, or
932 * NULL if there is not enough tailroom space in the last segment
934 static inline char *rte_pktmbuf_append(struct rte_mbuf *m, uint16_t len)
937 struct rte_mbuf *m_last;
939 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
941 m_last = rte_pktmbuf_lastseg(m);
942 if (unlikely(len > rte_pktmbuf_tailroom(m_last)))
945 tail = (char*) m_last->pkt.data + m_last->pkt.data_len;
946 m_last->pkt.data_len = (uint16_t)(m_last->pkt.data_len + len);
947 m->pkt.pkt_len = (m->pkt.pkt_len + len);
952 * Remove len bytes at the beginning of an mbuf.
954 * Returns a pointer to the start address of the new data area. If the
955 * length is greater than the length of the first segment, then the
956 * function will fail and return NULL, without modifying the mbuf.
961 * The amount of data to remove (in bytes).
963 * A pointer to the new start of the data.
965 static inline char *rte_pktmbuf_adj(struct rte_mbuf *m, uint16_t len)
967 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
969 if (unlikely(len > m->pkt.data_len))
972 m->pkt.data_len = (uint16_t)(m->pkt.data_len - len);
973 m->pkt.data = ((char*) m->pkt.data + len);
974 m->pkt.pkt_len = (m->pkt.pkt_len - len);
975 return (char*) m->pkt.data;
979 * Remove len bytes of data at the end of the mbuf.
981 * If the length is greater than the length of the last segment, the
982 * function will fail and return -1 without modifying the mbuf.
987 * The amount of data to remove (in bytes).
992 static inline int rte_pktmbuf_trim(struct rte_mbuf *m, uint16_t len)
994 struct rte_mbuf *m_last;
996 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
998 m_last = rte_pktmbuf_lastseg(m);
999 if (unlikely(len > m_last->pkt.data_len))
1002 m_last->pkt.data_len = (uint16_t)(m_last->pkt.data_len - len);
1003 m->pkt.pkt_len = (m->pkt.pkt_len - len);
1008 * Test if mbuf data is contiguous.
1013 * - 1, if all data is contiguous (one segment).
1014 * - 0, if there is several segments.
1016 static inline int rte_pktmbuf_is_contiguous(const struct rte_mbuf *m)
1018 __rte_mbuf_sanity_check(m, RTE_MBUF_PKT, 1);
1019 return !!(m->pkt.nb_segs == 1);
1023 * Dump an mbuf structure to the console.
1025 * Dump all fields for the given packet mbuf and all its associated
1026 * segments (in the case of a chained buffer).
1031 * If dump_len != 0, also dump the "dump_len" first data bytes of
1034 void rte_pktmbuf_dump(const struct rte_mbuf *m, unsigned dump_len);
1040 #endif /* _RTE_MBUF_H_ */