rte_mbuf(3)

💅 rte_mbuf 💅

okay so bestie, welcome to the rte_mbuf(3) page — that's section 3, Library Functions Manual, DPDK edition. This whole page is about the generic rte_mbuf, aka the packet mbuf, aka the lil container every packet in DPDK rides around in. Grab a boba, we're reading a struct together. 🍓

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✨ NAME ✨

rte_mbuf — that's the name, that's the whole name. Short, iconic, no notes. 👑

🎀 SYNOPSIS 🎀

#include <rte_mbuf_core.h>

🌸 Data Fields 🌸

listing these in exactly the order I was given them, no cap:

• void * buf_addr
• struct rte_mbuf * next
• uint64_t ol_flags
• struct rte_mempool * pool
• uint64_t dynfield2
• struct rte_mbuf_ext_shared_info * shinfo
• uint16_t priv_size
• uint16_t timesync
• uint32_t dynfield1 [9]

🦋 Detailed Description 🦋

okay so here's the tea: this is the the generic rte_mbuf, containing a packet mbuf. That's literally what it is — the generic mbuf that holds a packet. It's defined at line 475 of the file rte_mbuf_core.h. 🫶

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👑 Field Documentation 👑

🌟 void* buf_addr

Virtual address of the segment buffer. ✨

Definition at line 476 of file rte_mbuf_core.h.

🌟 struct rte_mbuf* next

Next segment of a scattered packet. This field is valid when the physical address field is undefined. Otherwise, the next pointer in the second cache line gets used instead. 💫

Definition at line 493 of file rte_mbuf_core.h.

🌟 uint16_t refcnt

Reference counter. Its size should at least equal the size of the port field (16 bits), so zero-copy broadcast can work. And lowkey important: it should only be accessed using rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(), and rte_mbuf_refcnt_set(). Whether those functions are atomic or non-atomic is controlled by the RTE_MBUF_REFCNT_ATOMIC flag. 🔥

Definition at line 514 of file rte_mbuf_core.h.

🌟 uint16_t nb_segs

Number of segments. Only valid for the first segment of an mbuf chain, bestie — first only, don't be out here reading it off segment three. 🙈

Definition at line 520 of file rte_mbuf_core.h.

🌟 uint16_t port

Input port (16 bits, so more than 256 virtual ports can exist). The event eth Tx adapter uses this field to specify the output port. 🎀

Definition at line 525 of file rte_mbuf_core.h.

🌟 uint64_t ol_flags

Offload features. ✨

Definition at line 529 of file rte_mbuf_core.h.

🌟 uint32_t packet_type

L2/L3/L4 and tunnel information. 🌈

Definition at line 545 of file rte_mbuf_core.h.

🌟 uint8_t l2_type

(Outer) L2 type.

Definition at line 548 of file rte_mbuf_core.h.

🌟 uint8_t l3_type

(Outer) L3 type.

Definition at line 549 of file rte_mbuf_core.h.

🌟 uint8_t l4_type

(Outer) L4 type.

Definition at line 550 of file rte_mbuf_core.h.

🌟 uint8_t tun_type

Tunnel type. 🕳️✨

Definition at line 551 of file rte_mbuf_core.h.

🌟 uint8_t inner_esp_next_proto

ESP next protocol type, valid if the RTE_PTYPE_TUNNEL_ESP tunnel type is set on both Tx and Rx.

Definition at line 553 of file rte_mbuf_core.h.

🌟 uint8_t inner_l2_type

Inner L2 type.

Definition at line 560 of file rte_mbuf_core.h.

🌟 uint8_t inner_l3_type

Inner L3 type.

Definition at line 562 of file rte_mbuf_core.h.

🌟 uint8_t inner_l4_type

Inner L4 type.

Definition at line 566 of file rte_mbuf_core.h.

🌟 uint32_t pkt_len

Total pkt len: the sum of all segments. 🧮

Definition at line 570 of file rte_mbuf_core.h.

🌟 uint16_t data_len

Amount of data in the segment buffer.

Definition at line 571 of file rte_mbuf_core.h.

🌟 uint16_t vlan_tci

VLAN TCI (CPU order), valid if RTE_MBUF_F_RX_VLAN is set. 💜

Definition at line 573 of file rte_mbuf_core.h.

🌟 uint32_t rss

RSS hash result, if RSS is enabled.

Definition at line 577 of file rte_mbuf_core.h.

🌟 uint32_t lo

Second 4 flexible bytes.

Definition at line 584 of file rte_mbuf_core.h.

🌟 uint32_t hi

First 4 flexible bytes or FD ID, dependent on the RTE_MBUF_F_RX_FDIR_* flag in ol_flags. 👀

Definition at line 587 of file rte_mbuf_core.h.

🌟 struct { ... } fdir

Filter identifier, if FDIR is enabled.

🌟 struct rte_mbuf_sched sched

Hierarchical scheduler : 8 bytes.

Definition at line 592 of file rte_mbuf_core.h.

🌟 uint16_t txq

The event eth Tx adapter uses this field to store the Tx queue id.

See also: rte_event_eth_tx_adapter_txq_set()

Definition at line 597 of file rte_mbuf_core.h.

🌟 struct { ... } txadapter

Eventdev ethdev Tx adapter.

🌟 uint32_t usr

User defined tags. See rte_distributor_process(). 🏷️

Definition at line 603 of file rte_mbuf_core.h.

🌟 union { ... } hash

hash information.

🌟 uint16_t vlan_tci_outer

Outer VLAN TCI (CPU order), valid if RTE_MBUF_F_RX_QINQ is set. 💅

Definition at line 609 of file rte_mbuf_core.h.

🌟 uint16_t buf_len

Length of the segment buffer.

Definition at line 611 of file rte_mbuf_core.h.

🌟 struct rte_mempool* pool

Pool from which the mbuf was allocated. 🏊

Definition at line 615 of file rte_mbuf_core.h.

🌟 uint64_t dynfield2

Reserved for dynamic fields when the next pointer is in the first cache line (i.e. RTE_IOVA_IN_MBUF is 0). ✨

Definition at line 635 of file rte_mbuf_core.h.

🌟 uint64_t tx_offload

combined for easy fetch.

Definition at line 640 of file rte_mbuf_core.h.

🌟 uint64_t l2_len

L2 (MAC) Header Length for a non-tunneling pkt. For a tunneling pkt: Outer_L4_len + ... + Inner_L2_len. 🧵

Definition at line 643 of file rte_mbuf_core.h.

🌟 uint64_t l3_len

L3 (IP) Header Length.

Definition at line 647 of file rte_mbuf_core.h.

🌟 uint64_t l4_len

L4 (TCP/UDP) Header Length.

Definition at line 649 of file rte_mbuf_core.h.

🌟 uint64_t tso_segsz

TCP TSO segment size.

Definition at line 651 of file rte_mbuf_core.h.

🌟 uint64_t outer_l3_len

Outer L3 (IP) Hdr Length.

Definition at line 666 of file rte_mbuf_core.h.

🌟 uint64_t outer_l2_len

Outer L2 (MAC) Hdr Length.

Definition at line 668 of file rte_mbuf_core.h.

🌟 struct rte_mbuf_ext_shared_info* shinfo

Shared data for an external buffer attached to the mbuf. See rte_pktmbuf_attach_extbuf(). 🔗

Definition at line 678 of file rte_mbuf_core.h.

🌟 uint16_t priv_size

Size of the application private data. In the case of an indirect mbuf, it stores the direct mbuf's private data size. 🧺

Definition at line 683 of file rte_mbuf_core.h.

🌟 uint16_t timesync

Timesync flags, for use with IEEE1588. ⏰

Definition at line 686 of file rte_mbuf_core.h.

🌟 uint32_t dynfield1[9]

Reserved for dynamic fields.

Definition at line 688 of file rte_mbuf_core.h.

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🫶 Author 🫶

Generated automatically by Doxygen for DPDK from the source code. (Not a human, not a girlie, just Doxygen doing its lil thing. 💖)

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and that's the whole page bestie!! this was DPDK, Version 25.11.3 — that's the footer energy right there, no date on this one, just the version. mwah 💋 go forth and mbuf responsibly 👑✨