源码分析: Mbuf ¶

更新于2019.03.30

源码分析: Mbuf

概述 ¶

DPDK mbuf实现了message buffer，可以存储报文数据或者控制信息等。mbuf存储在mempool中，以便在数据面提高访问性能。

原理 ¶

DPDK把元数据(metadata)和实际数据存储在一个mbuf中，并且使mbuf结构体尽量小，目前仅占用2个cache line，且最常访问的成员在第1个cache line中。

mbuf从前至后主要由mbuf首部(即rte_mbuf结构体)、head room、实际数据和tailroom构成。用户还可以在mbuf首部和head room之前加入一定长度的私有数据(private data)。head room的大小在DPDK编译配置文件(如common_linuxapp)中指定，如 CONFIG_RTE_PKTMBUF_HEADROOM=128 。mbuf的基本结构如下图所示：

一些指针、成员或函数结果的内容在下表中列出，mbuf指针简写为m：

项	内容
m	首部，即mbuf结构体
m->buf_addr	headroom起始地址
m->data_off	data起始地址相对于buf_addr的偏移
m->buf_len	mbuf和priv之后内存的长度，包含headroom
m->pkt_len	整个mbuf链的data总长度
m->data_len	实际data的长度
m->buf_addr+m->data_off	实际data的起始地址
rte_pktmbuf_mtod(m)	同上
rte_pktmbuf_data_len(m)	同m->data_len
rte_pktmbuf_pkt_len	同m->pkt_len
rte_pktmbuf_data_room_size	同m->buf_len
rte_pktmbuf_headroom	headroom长度
rte_pktmbuf_tailroom	尾部剩余空间长度

注：data_off = MIN(headroom_len, buf_len)

上图中的buf只有一个数据段，在某些情况下，比如要处理巨帧(jumbo frame)时，可以把多个mbuf链接起来组成一个mbuf。下图是包含3个数据段的mbuf：

对于链式的mbuf，仅在第一个mbuf结构体中包含元数据信息。

以下代码分别创建了两个mbuf，给它们添加数据，最后将它们组合成链。在此过程中打印了上表中的一些数据，可以帮助理解各指针和长度的含义，其中省去了错误处理代码。

static int mbuf_demo(void)
{
    int ret;
    struct rte_mempool* mpool;
    struct rte_mbuf *m, *m2;
    struct rte_pktmbuf_pool_private priv;

    priv.mbuf_data_room_size = 1600 + RTE_PKTMBUF_HEADROOM - 16;
    priv.mbuf_priv_size = 16;
    mpool = rte_mempool_create("test_pool",
                               ITEM_COUNT,
                               ITEM_SIZE,
                               CACHE_SIZE,
                               sizeof(struct rte_pktmbuf_pool_private),
                               rte_pktmbuf_pool_init,
                               &priv,
                               rte_pktmbuf_init,
                               NULL,
                               0,
                               MEMPOOL_F_SC_GET);
    m = rte_pktmbuf_alloc(mpool);
    mbuf_dump(m);   // (1)

    rte_pktmbuf_append(m, 1400);
    mbuf_dump(m);   // (2)

    m2 = rte_pktmbuf_alloc(mpool);
    rte_pktmbuf_append(m2, 500);
    mbuf_dump(m2);

    ret = rte_pktmbuf_chain(m, m2);
    mbuf_dump(m);   // (3)

    return 0;
}

首先注意第8，9，16行，为了演示用户私有数据，在创建mempool时传入了priv，这将在每个mbuf的首部后面添加16字节的私有数据，然后才是head room。内存池对象数目、第个对象的大小和cache大小分别是:

#define ITEM_COUNT 1024
#define ITEM_SIZE  (1600 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
#define CACHE_SIZE 32

1600是预估的一个packet的最大长度。

在(1)处，新分配了一个mbuf m，此时m的data长度为0，打印结果如下:

RTE_PKTMBUF_HEADROOM: 128
sizeof(mbuf): 128
m: 0x7fbf1a810000
m->buf_addr: 0x7fbf1a810090
m->data_off: 128
m->buf_len: 1712
m->pkt_len: 0
m->data_len: 0
m->buf_addr+m->data_off: 0x7fbf1a810110
rte_pktmbuf_mtod(m): 0x7fbf1a810110
rte_pktmbuf_data_len(m): 0
rte_pktmbuf_pkt_len(m): 0
rte_pktmbuf_headroom(m): 128
rte_pktmbuf_tailroom(m): 1584
rte_pktmbuf_data_room_size(mpool): 1712
rte_pktmbuf_priv_size(mpool): 16

用图表示如下：

在(2)，用rte_pktmbuf_append模拟给m填充了1400字节的data，此时打印结果如下:

m: 0x7fbf1a810000
m->buf_addr: 0x7fbf1a810090
m->data_off: 128
m->buf_len: 1712
m->pkt_len: 1400
m->data_len: 1400
m->buf_addr+m->data_off: 0x7fbf1a810110
rte_pktmbuf_mtod(m): 0x7fbf1a810110
rte_pktmbuf_data_len(m): 1400
rte_pktmbuf_pkt_len(m): 1400
rte_pktmbuf_headroom(m): 128
rte_pktmbuf_tailroom(m): 184
rte_pktmbuf_data_room_size(mpool): 1712
rte_pktmbuf_priv_size(mpool): 16

用图表示如下：

之后创建m2并给它添加data，在(3)处将m与m2连接，m做为链的首节点，此时m的打印结果如下:

m: 0x7fbf1a810000
m->buf_addr: 0x7fbf1a810090
m->data_off: 128
m->buf_len: 1712
m->pkt_len: 1900
m->data_len: 1400
m->buf_addr+m->data_off: 0x7fbf1a810110
rte_pktmbuf_mtod(m): 0x7fbf1a810110
rte_pktmbuf_data_len(m): 1400
rte_pktmbuf_pkt_len(m): 1900
rte_pktmbuf_headroom(m): 128
rte_pktmbuf_tailroom(m): 184
rte_pktmbuf_data_room_size(mpool): 1712
rte_pktmbuf_priv_size(mpool): 16

注意pkt_len的变化，它已经加上了m2的500字节。如果此时打印m—>next，会发现m->next == m2。

数据结构 ¶

rte_mbuf(librte_mbuf/rte_mbuf.h):

struct rte_mbuf {
    MARKER cacheline0;

    void *buf_addr;           /**< Virtual address of segment buffer. */
    phys_addr_t buf_physaddr; /**< Physical address of segment buffer. */

    uint16_t buf_len;         /**< Length of segment buffer. */

    /* next 6 bytes are initialised on RX descriptor rearm */
    MARKER8 rearm_data;
    uint16_t data_off;

    /**
     * 16-bit Reference counter.
     * It should only be accessed using the following functions:
     * rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(), and
     * rte_mbuf_refcnt_set(). The functionality of these functions (atomic,
     * or non-atomic) is controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC
     * config option.
     */
    union {
        rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */
        uint16_t refcnt;              /**< Non-atomically accessed refcnt */
    };
    uint8_t nb_segs;          /**< Number of segments. */
    uint8_t port;             /**< Input port. */

    uint64_t ol_flags;        /**< Offload features. */

    /* remaining bytes are set on RX when pulling packet from descriptor */
    MARKER rx_descriptor_fields1;

    /*
     * The packet type, which is the combination of outer/inner L2, L3, L4
     * and tunnel types.
     */
    union {
        uint32_t packet_type; /**< L2/L3/L4 and tunnel information. */
        struct {
            uint32_t l2_type:4; /**< (Outer) L2 type. */
            uint32_t l3_type:4; /**< (Outer) L3 type. */
            uint32_t l4_type:4; /**< (Outer) L4 type. */
            uint32_t tun_type:4; /**< Tunnel type. */
            uint32_t inner_l2_type:4; /**< Inner L2 type. */
            uint32_t inner_l3_type:4; /**< Inner L3 type. */
            uint32_t inner_l4_type:4; /**< Inner L4 type. */
        };
    };

    uint32_t pkt_len;         /**< Total pkt len: sum of all segments. */
    uint16_t data_len;        /**< Amount of data in segment buffer. */
    uint16_t vlan_tci;        /**< VLAN Tag Control Identifier (CPU order) */

    union {
        uint32_t rss;     /**< RSS hash result if RSS enabled */
        struct {
            union {
                struct {
                    uint16_t hash;
                    uint16_t id;
                };
                uint32_t lo;
                /**< Second 4 flexible bytes */
            };
            uint32_t hi;
            /**< First 4 flexible bytes or FD ID, dependent on
                 PKT_RX_FDIR_* flag in ol_flags. */
        } fdir;           /**< Filter identifier if FDIR enabled */
        struct {
            uint32_t lo;
            uint32_t hi;
        } sched;          /**< Hierarchical scheduler */
        uint32_t usr;         /**< User defined tags. See rte_distributor_process() */
    } hash;                   /**< hash information */

    uint32_t seqn; /**< Sequence number. See also rte_reorder_insert() */

    uint16_t vlan_tci_outer;  /**< Outer VLAN Tag Control Identifier (CPU order) */

    /* second cache line - fields only used in slow path or on TX */
    MARKER cacheline1 __rte_cache_aligned;

    union {
        void *userdata;   /**< Can be used for external metadata */
        uint64_t udata64; /**< Allow 8-byte userdata on 32-bit */
    };

    struct rte_mempool *pool; /**< Pool from which mbuf was allocated. */
    struct rte_mbuf *next;    /**< Next segment of scattered packet. */

    /* fields to support TX offloads */
    union {
        uint64_t tx_offload;       /**< combined for easy fetch */
        struct {
            uint64_t l2_len:7; /**< L2 (MAC) Header Length. */
            uint64_t l3_len:9; /**< L3 (IP) Header Length. */
            uint64_t l4_len:8; /**< L4 (TCP/UDP) Header Length. */
            uint64_t tso_segsz:16; /**< TCP TSO segment size */

            /* fields for TX offloading of tunnels */
            uint64_t outer_l3_len:9; /**< Outer L3 (IP) Hdr Length. */
            uint64_t outer_l2_len:7; /**< Outer L2 (MAC) Hdr Length. */

            /* uint64_t unused:8; */
        };
    };

    /** Size of the application private data. In case of an indirect
     * mbuf, it stores the direct mbuf private data size. */
    uint16_t priv_size;

    /** Timesync flags for use with IEEE1588. */
    uint16_t timesync;

    /* Chain of off-load operations to perform on mbuf */
    struct rte_mbuf_offload *offload_ops;
}

indirect mbuf机制有一些限制条件：

不能attach一个indirect mbuf
attach之前，mbuf的引用计数必须是1，也就是说，它没有被其他mbuf引用过
不能把indirect mbuf再次attach到一个direct mbuf，除非先deattch

虽然可以直接调用attach/detach操作，但推荐使用clone操作来浅拷贝mbuf，因为clone会正确处理链式mbuf。

Packet Type ¶

概述 ¶

rte_mbuf有32bit的packet type成员, 其构成如下所示:

0               4               8               12              16
+---------------+---------------+---------------+---------------+
| outer_L2_type | outer_L3_type | outer_L4_type |  tunnel_type  |
+---------------+---------------+---------------+---------------+
| inner_L2_type | inner_L3_type | inner_L4_type |               |
+---------------+---------------+---------------+---------------+

为了方便, 这32bit可以使用packet_type成员来一次性访问. 不同网卡对同一个报文的报文类型的识别结果是不同的.

下面是两个例子. 以下封装的报文:

<'ether type'=0x0800
| 'version'=4, 'protocol'=0x29
| 'version'=6, 'next header'=0x3A
| 'ICMPv6 header'>

在i40e网卡上解析的报文类型如下:

RTE_PTYPE_L2_ETHER |
RTE_PTYPE_L3_IPV4_EXT_UNKNOWN |
RTE_PTYPE_TUNNEL_IP |
RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
RTE_PTYPE_INNER_L4_ICMP

以下封装的报文:

<'ether type'=0x86DD
| 'version'=6, 'next header'=0x2F
| 'GRE header'
| 'version'=6, 'next header'=0x11
| 'UDP header'>

在i40e网卡上解析的报文类型如下:

RTE_PTYPE_L2_ETHER |
RTE_PTYPE_L3_IPV6_EXT_UNKNOWN |
RTE_PTYPE_TUNNEL_GRENAT |
RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN |
RTE_PTYPE_INNER_L4_UDP

不同类型含义 ¶

RTE_PTYPE_UNKNOWN ¶

表示不包含任何报文类型信息:

/**
* No packet type information.
*/
#define RTE_PTYPE_UNKNOWN                   0x00000000

RTE_PTYPE_L2_ETHER ¶

2层: Ethernet类型, tunnel情况中用于外层报文:

/**
* Ethernet packet type.
* It is used for outer packet for tunneling cases.
*
* Packet format:
* <'ether type'=[0x0800|0x86DD]>
*/
#define RTE_PTYPE_L2_ETHER                  0x00000001

RTE_PTYPE_L2_ETHER_TIMESYNC ¶

2层: 时间同步类型:

/**
* Ethernet packet type for time sync.
*
* Packet format:
* <'ether type'=0x88F7>
*/
#define RTE_PTYPE_L2_ETHER_TIMESYNC         0x00000002

RTE_PTYPE_L2_ETHER_ARP ¶

2层: ARP类型:

/**
* ARP (Address Resolution Protocol) packet type.
*
* Packet format:
* <'ether type'=0x0806>
*/
#define RTE_PTYPE_L2_ETHER_ARP              0x00000003

RTE_PTYPE_L2_ETHER_LLDP ¶

2层: LLDP类型:

/**
* LLDP (Link Layer Discovery Protocol) packet type.
*
* Packet format:
* <'ether type'=0x88CC>
*/
#define RTE_PTYPE_L2_ETHER_LLDP             0x00000004

RTE_PTYPE_L2_ETHER_NSH ¶

2层: NSH类型:

/**
* NSH (Network Service Header) packet type.
*
* Packet format:
* <'ether type'=0x894F>
*/
#define RTE_PTYPE_L2_ETHER_NSH              0x00000005

RTE_PTYPE_L2_ETHER_VLAN ¶

2层: VLAN类型:

/**
* VLAN packet type.
*
* Packet format:
* <'ether type'=[0x8100]>
*/
#define RTE_PTYPE_L2_ETHER_VLAN             0x00000006

RTE_PTYPE_L2_ETHER_QINQ ¶

2层: QinQ类型:

/**
* QinQ packet type.
*
* Packet format:
* <'ether type'=[0x88A8]>
*/
#define RTE_PTYPE_L2_ETHER_QINQ             0x00000007

RTE_PTYPE_L2_MASK ¶

2层类型掩码:

/**
* Mask of layer 2 packet types.
* It is used for outer packet for tunneling cases.
*/
#define RTE_PTYPE_L2_MASK                   0x0000000f

RTE_PTYPE_L3_IPV4 ¶

3层: IPv4类型, 不包含选项, bit位``0001``

/**
* IP (Internet Protocol) version 4 packet type.
* It is used for outer packet for tunneling cases, and does not contain any
* header option.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'ihl'=5>
*/
#define RTE_PTYPE_L3_IPV4                   0x00000010

RTE_PTYPE_L3_IPV4_EXT ¶

3层: IPv4类型, 包含选项, bit位``0011``

/**
* IP (Internet Protocol) version 4 packet type.
* It is used for outer packet for tunneling cases, and contains header
* options.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'ihl'=[6-15], 'options'>
*/
#define RTE_PTYPE_L3_IPV4_EXT               0x00000030

RTE_PTYPE_L3_IPV6 ¶

3层: IPv6类型, 不包含扩展首部, bit位``0100``

/**
* IP (Internet Protocol) version 6 packet type.
* It is used for outer packet for tunneling cases, and does not contain any
* extension header.
*
* Packet format:
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=0x3B>
*/
#define RTE_PTYPE_L3_IPV6                   0x00000040

RTE_PTYPE_L3_IPV4_EXT_UNKNOWN ¶

3层: IPv4类型, 有可能包含, 也有可能不包含选项, bit位``1001``

/**
* IP (Internet Protocol) version 4 packet type.
* It is used for outer packet for tunneling cases, and may or maynot contain
* header options.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'ihl'=[5-15], <'options'>>
*/
#define RTE_PTYPE_L3_IPV4_EXT_UNKNOWN       0x00000090

RTE_PTYPE_L3_IPV6_EXT ¶

3层: IPv6类型, 包含扩展首部, bit位``1100``

/**
* IP (Internet Protocol) version 6 packet type.
* It is used for outer packet for tunneling cases, and contains extension
* headers.
*
* Packet format:
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=[0x0|0x2B|0x2C|0x32|0x33|0x3C|0x87],
*   'extension headers'>
*/
#define RTE_PTYPE_L3_IPV6_EXT               0x000000c0

RTE_PTYPE_L3_IPV6_EXT_UNKNOWN ¶

3层: IPv6类型, 有可能包含, 也有可能不包含扩展首部, bit位``1110``

/**
* IP (Internet Protocol) version 6 packet type.
* It is used for outer packet for tunneling cases, and may or maynot contain
* extension headers.
*
* Packet format:
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=[0x3B|0x0|0x2B|0x2C|0x32|0x33|0x3C|0x87],
*   <'extension headers'>>
*/
#define RTE_PTYPE_L3_IPV6_EXT_UNKNOWN       0x000000e0

RTE_PTYPE_L3_MASK ¶

3层类型掩码:

/**
* Mask of layer 3 packet types.
* It is used for outer packet for tunneling cases.
*/
#define RTE_PTYPE_L3_MASK                   0x000000f0

RTE_PTYPE_L4_TCP ¶

4层: TCP, 如果下层是IPv4, 则它后面没有更多分片

/**
* TCP (Transmission Control Protocol) packet type.
* It is used for outer packet for tunneling cases.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=6, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=6>
*/
#define RTE_PTYPE_L4_TCP                    0x00000100

RTE_PTYPE_L4_UDP ¶

4层: UDP, 如果下层是IPv4, 则它后面没有更多分片

/**
* UDP (User Datagram Protocol) packet type.
* It is used for outer packet for tunneling cases.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17>
*/
#define RTE_PTYPE_L4_UDP                    0x00000200

RTE_PTYPE_L4_FRAG ¶

4层: IPv4或IPv6分片类型, 这样的报文无法被识别为其他4层协议:

/**
* Fragmented IP (Internet Protocol) packet type.
* It is used for outer packet for tunneling cases.
*
* It refers to those packets of any IP types, which can be recognized as
* fragmented. A fragmented packet cannot be recognized as any other L4 types
* (RTE_PTYPE_L4_TCP, RTE_PTYPE_L4_UDP, RTE_PTYPE_L4_SCTP, RTE_PTYPE_L4_ICMP,
* RTE_PTYPE_L4_NONFRAG).
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'MF'=1>
* or,
* <'ether type'=0x0800
* | 'version'=4, 'frag_offset'!=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=44>
*/
#define RTE_PTYPE_L4_FRAG                   0x00000300

RTE_PTYPE_L4_SCTP ¶

4层: SCTP类型, 如果下层是IPv4, 则它后面没有更多分片

/**
* SCTP (Stream Control Transmission Protocol) packet type.
* It is used for outer packet for tunneling cases.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=132, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=132>
*/
#define RTE_PTYPE_L4_SCTP                   0x00000400

RTE_PTYPE_L4_ICMP ¶

4层: ICMP, 如果下层是IPv4, 则它后面没有更多分片

/**
* ICMP (Internet Control Message Protocol) packet type.
* It is used for outer packet for tunneling cases.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=1, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=1>
*/
#define RTE_PTYPE_L4_ICMP                   0x00000500

RTE_PTYPE_L4_NONFRAG ¶

4层: IP不分片, 但无法识别为其他4层协议的类型:

/**
* Non-fragmented IP (Internet Protocol) packet type.
* It is used for outer packet for tunneling cases.
*
* It refers to those packets of any IP types, while cannot be recognized as
* any of above L4 types (RTE_PTYPE_L4_TCP, RTE_PTYPE_L4_UDP,
* RTE_PTYPE_L4_FRAG, RTE_PTYPE_L4_SCTP, RTE_PTYPE_L4_ICMP).
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'!=[6|17|132|1], 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'!=[6|17|44|132|1]>
*/
#define RTE_PTYPE_L4_NONFRAG                0x00000600

RTE_PTYPE_L4_MASK ¶

4层类型掩码:

/**
* Mask of layer 4 packet types.
* It is used for outer packet for tunneling cases.
*/
#define RTE_PTYPE_L4_MASK                   0x00000f00

RTE_PTYPE_TUNNEL_IP ¶

tunnel: IP in IP类型:

/**
* IP (Internet Protocol) in IP (Internet Protocol) tunneling packet type.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=[4|41]>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=[4|41]>
*/
#define RTE_PTYPE_TUNNEL_IP                 0x00001000

RTE_PTYPE_TUNNEL_GRE ¶

tunnel: GRE类型:

/**
* GRE (Generic Routing Encapsulation) tunneling packet type.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=47>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=47>
*/
#define RTE_PTYPE_TUNNEL_GRE                0x00002000

RTE_PTYPE_TUNNEL_VXLAN ¶

tunnel: VXLAN类型:

/**
* VXLAN (Virtual eXtensible Local Area Network) tunneling packet type.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17
* | 'destination port'=4789>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17
* | 'destination port'=4789>
*/
#define RTE_PTYPE_TUNNEL_VXLAN              0x00003000

RTE_PTYPE_TUNNEL_NVGRE ¶

tunnel: NVGRE类型:

/**
* NVGRE (Network Virtualization using Generic Routing Encapsulation) tunneling
* packet type.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=47
* | 'protocol type'=0x6558>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=47
* | 'protocol type'=0x6558'>
*/
#define RTE_PTYPE_TUNNEL_NVGRE              0x00004000

RTE_PTYPE_TUNNEL_GENEVE ¶

tunnel: GENEVE类型:

/**
* GENEVE (Generic Network Virtualization Encapsulation) tunneling packet type.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17
* | 'destination port'=6081>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17
* | 'destination port'=6081>
*/
#define RTE_PTYPE_TUNNEL_GENEVE             0x00005000

RTE_PTYPE_TUNNEL_GRENAT ¶

tunnel: VXLAN或GRE类型, 因为有的网卡无法单独识别这两种类型:

/**
* Tunneling packet type of Teredo, VXLAN (Virtual eXtensible Local Area
* Network) or GRE (Generic Routing Encapsulation) could be recognized as this
* packet type, if they can not be recognized independently as of hardware
* capability.
*/
#define RTE_PTYPE_TUNNEL_GRENAT             0x00006000

RTE_PTYPE_TUNNEL_GTPC ¶

tunnel: GTP-C类型:

/**
* GTP-C (GPRS Tunnelling Protocol) control tunneling packet type.
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17
* | 'destination port'=2123>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17
* | 'destination port'=2123>
* or,
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17
* | 'source port'=2123>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17
* | 'source port'=2123>
*/
#define RTE_PTYPE_TUNNEL_GTPC               0x00007000

RTE_PTYPE_TUNNEL_GTPU ¶

tunnel: GTP-U类型:

/**
* GTP-U (GPRS Tunnelling Protocol) user data tunneling packet type.
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17
* | 'destination port'=2152>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17
* | 'destination port'=2152>
*/
#define RTE_PTYPE_TUNNEL_GTPU               0x00008000

RTE_PTYPE_TUNNEL_ESP ¶

tunnel: ESP类型

/**
* ESP (IP Encapsulating Security Payload) tunneling packet type.
*
* Packet format:
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=51>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=51>
*/
#define RTE_PTYPE_TUNNEL_ESP                0x00009000

RTE_PTYPE_TUNNEL_MASK ¶

tunnel类型掩码:

/**
* Mask of tunneling packet types.
*/
#define RTE_PTYPE_TUNNEL_MASK               0x0000f000

RTE_PTYPE_INNER_L2_ETHER ¶

内层中的2层: Ethernet类型:

/**
* Ethernet packet type.
* It is used for inner packet type only.
*
* Packet format (inner only):
* <'ether type'=[0x800|0x86DD]>
*/
#define RTE_PTYPE_INNER_L2_ETHER            0x00010000

RTE_PTYPE_INNER_L2_ETHER_VLAN ¶

内层中的2层: VLAN类型:

/**
* Ethernet packet type with VLAN (Virtual Local Area Network) tag.
*
* Packet format (inner only):
* <'ether type'=[0x800|0x86DD], vlan=[1-4095]>
*/
#define RTE_PTYPE_INNER_L2_ETHER_VLAN       0x00020000

RTE_PTYPE_INNER_L2_ETHER_QINQ ¶

内层中的2层: QinQ类型:

/**
* QinQ packet type.
*
* Packet format:
* <'ether type'=[0x88A8]>
*/
#define RTE_PTYPE_INNER_L2_ETHER_QINQ       0x00030000

RTE_PTYPE_INNER_L2_MASK ¶

内层中的2层掩码:

/**
* Mask of inner layer 2 packet types.
*/
#define RTE_PTYPE_INNER_L2_MASK             0x000f0000

RTE_PTYPE_INNER_L3_IPV4 ¶

内层中的3层: IPv4类型, 不包含选项

/**
* IP (Internet Protocol) version 4 packet type.
* It is used for inner packet only, and does not contain any header option.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'ihl'=5>
*/
#define RTE_PTYPE_INNER_L3_IPV4             0x00100000

RTE_PTYPE_INNER_L3_IPV4_EXT ¶

内层中的3层: IPv4类型, 包含选项

/**
* IP (Internet Protocol) version 4 packet type.
* It is used for inner packet only, and contains header options.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'ihl'=[6-15], 'options'>
*/
#define RTE_PTYPE_INNER_L3_IPV4_EXT         0x00200000

RTE_PTYPE_INNER_L3_IPV6 ¶

内层中的3层: IPv6类型, 不包含扩展首部

/**
* IP (Internet Protocol) version 6 packet type.
* It is used for inner packet only, and does not contain any extension header.
*
* Packet format (inner only):
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=0x3B>
*/
#define RTE_PTYPE_INNER_L3_IPV6             0x00300000

RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN ¶

内层中的3层: IPv4类型, 有可能包含, 也有可能不包含选项

/**
* IP (Internet Protocol) version 4 packet type.
* It is used for inner packet only, and may or maynot contain header options.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'ihl'=[5-15], <'options'>>
*/
#define RTE_PTYPE_INNER_L3_IPV4_EXT_UNKNOWN 0x00400000

RTE_PTYPE_INNER_L3_IPV6_EXT ¶

内层中的3层: IPv6类型, 包含扩展首部

/**
* IP (Internet Protocol) version 6 packet type.
* It is used for inner packet only, and contains extension headers.
*
* Packet format (inner only):
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=[0x0|0x2B|0x2C|0x32|0x33|0x3C|0x87],
*   'extension headers'>
*/
#define RTE_PTYPE_INNER_L3_IPV6_EXT         0x00500000

RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN ¶

内层中的3层: IPv6类型, 可能包含, 也可能不包含扩展首部

/**
* IP (Internet Protocol) version 6 packet type.
* It is used for inner packet only, and may or maynot contain extension
* headers.
*
* Packet format (inner only):
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=[0x3B|0x0|0x2B|0x2C|0x32|0x33|0x3C|0x87],
*   <'extension headers'>>
*/
#define RTE_PTYPE_INNER_L3_IPV6_EXT_UNKNOWN 0x00600000

RTE_PTYPE_INNER_L3_MASK ¶

内层中的3层类型掩码:

/**
* Mask of inner layer 3 packet types.
*/
#define RTE_PTYPE_INNER_L3_MASK             0x00f00000

RTE_PTYPE_INNER_L4_TCP ¶

内层中的4层: TCP, 如果下层是IPv4, 则它后面没有更多分片

/**
* TCP (Transmission Control Protocol) packet type.
* It is used for inner packet only.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=6, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=6>
*/
#define RTE_PTYPE_INNER_L4_TCP              0x01000000

RTE_PTYPE_INNER_L4_UDP ¶

内层中的4层: UDP, 如果下层是IPv4, 则它后面没有更多分片

/**
* UDP (User Datagram Protocol) packet type.
* It is used for inner packet only.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=17, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=17>
*/
#define RTE_PTYPE_INNER_L4_UDP              0x02000000

RTE_PTYPE_INNER_L4_FRAG ¶

内层中的4层: IP分片类型, 可能包含, 也可能不包含4层类型

/**
* Fragmented IP (Internet Protocol) packet type.
* It is used for inner packet only, and may or maynot have layer 4 packet.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'MF'=1>
* or,
* <'ether type'=0x0800
* | 'version'=4, 'frag_offset'!=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=44>
*/
#define RTE_PTYPE_INNER_L4_FRAG             0x03000000

RTE_PTYPE_INNER_L4_SCTP ¶

内层中的4层: SCTP, 如果下层是IPv4, 则它后面没有更多分片

/**
* SCTP (Stream Control Transmission Protocol) packet type.
* It is used for inner packet only.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=132, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=132>
*/
#define RTE_PTYPE_INNER_L4_SCTP             0x04000000

RTE_PTYPE_INNER_L4_ICMP ¶

内层中的4层: ICMP, 如果下层是IPv4, 则它后面没有更多分片

/**
* ICMP (Internet Control Message Protocol) packet type.
* It is used for inner packet only.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'protocol'=1, 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'=1>
*/
#define RTE_PTYPE_INNER_L4_ICMP             0x05000000

RTE_PTYPE_INNER_L4_NONFRAG ¶

内层中的4层: 不分片的IP类型, 可能包含也可能不饮食其他4层类型

/**
* Non-fragmented IP (Internet Protocol) packet type.
* It is used for inner packet only, and may or maynot have other unknown layer
* 4 packet types.
*
* Packet format (inner only):
* <'ether type'=0x0800
* | 'version'=4, 'protocol'!=[6|17|132|1], 'MF'=0, 'frag_offset'=0>
* or,
* <'ether type'=0x86DD
* | 'version'=6, 'next header'!=[6|17|44|132|1]>
*/
#define RTE_PTYPE_INNER_L4_NONFRAG          0x06000000

RTE_PTYPE_INNER_L4_MASK ¶

内层中的4层掩码:

/**
* Mask of inner layer 4 packet types.
*/
#define RTE_PTYPE_INNER_L4_MASK             0x0f000000

RTE_PTYPE_ALL_MASK ¶

报文类型整体掩码:

/**
* All valid layer masks.
*/
#define RTE_PTYPE_ALL_MASK                  0x0fffffff

RTE_ETH_IS_IPV4_HDR ¶

宏: 检查外层的3层类型是否为IPv4:

/**
* Check if the (outer) L3 header is IPv4. To avoid comparing IPv4 types one by
* one, bit 4 is selected to be used for IPv4 only. Then checking bit 4 can
* determine if it is an IPv4 packet.
*/
#define  RTE_ETH_IS_IPV4_HDR(ptype) ((ptype) & RTE_PTYPE_L3_IPV4)

RTE_ETH_IS_IPV6_HDR ¶

宏: 检查外层的3层类型是否为IPv6:

/**
* Check if the (outer) L3 header is IPv6. To avoid comparing IPv4 types one by
* one, bit 6 is selected to be used for IPv6 only. Then checking bit 6 can
* determine if it is an IPv6 packet.
*/
#define  RTE_ETH_IS_IPV6_HDR(ptype) ((ptype) & RTE_PTYPE_L3_IPV6)

RTE_ETH_IS_TUNNEL_PKT ¶

宏: 检查是否为tunnel报文:

/* Check if it is a tunneling packet */
#define RTE_ETH_IS_TUNNEL_PKT(ptype) ((ptype) &                             \
    (RTE_PTYPE_TUNNEL_MASK |                                        \
        RTE_PTYPE_INNER_L2_MASK |                           \
        RTE_PTYPE_INNER_L3_MASK |                           \
        RTE_PTYPE_INNER_L4_MASK))

参考 ¶

DPDK Programmer’s Guide - Mbuf Library
DPDK源码: lib/librte_mbuf/rte_mbuf.h
DPDK源码: lib/librte_mbuf/rte_mbuf_ptype.h
DPDK Test Plans - Unified Packet Type Tests