究竟他在kernel里加了什么以支持mpls？

1 加了netlink相关命令和属性

MPLS_ATTR_ILM

MPLS_CMD_NEWILM

2 arp处加了mpls tunnel接口

ARPHRD_MPLS_TUNNEL

3 网卡中加入mpls属性

net_device

mpls_ptr

4 加了

RTA_SHIM (FIXME)

5 加了socket

AF_MPLS

6 加了

NET_MPLS

7 fib_config里加了rt_shim

8 fib表的操作是大头 rtm_to_fib_config

        case RTA_SHIM:

            memcpy(&cfg->fc_shim, nla_data(attr), nla_len(attr));

9 独立文件的增加

mpls.h

    MPLS_OP_POP,

    MPLS_OP_PEEK,

    MPLS_OP_PUSH,

    MPLS_OP_DLV,

    MPLS_OP_FWD,

标签操作

10 shim.h

内容？（FIXME）

11 net/mpls.h

/****************************************************************************

 * MPLS Interface "Extension"

 * In the current implementation the "all loved" net_device struct is

 * extended with one field struct mpls_interface (cast'd to void) called

 * mpls_ptr; This holds basically the "per interface" labelspace.

 ****************************************************************************/

struct mpls_interface {

    /*  

     * (any mif object)->list_out is a circular d-linked list. Each node

     * of this list is a NHLFE. NHLFE's are added to this list when adding a

     * OP_SET opcode to a nhlfe instruction array.

     *

     * list_add(&nhlfe->dev_entry, &mpls_if->list_out) : adds nhlfe to this

     * list.

     *

     * "List of all NHLFEs that use this device (e.g. eth0) as output"

     * cf. mpls_init.c

     */

    struct list_head list_out;

                             

    /*  

     * (any mif object)->list_in is a circular d-linked list. Each node

     * of this list is a ILM. ILM's are added to this list when

     */

    struct list_head list_in;  

    /*

     * Label Space for this interface

     */

    int  labelspace;  

};

要用到radix树

12

桥下操作 mplsbr, 桥下过滤 netfilter/mpls

13

shim操作

14

static struct mpls_prot_driver mpls4_driver = {

    .name            =    "ipv4",

    .family                 =       AF_INET,

    .ethertype              =       __constant_htons(ETH_P_IP),

    .cache_flush            =       mpls4_cache_flush,

    .set_ttl                =       mpls4_set_ttl,

    .get_ttl                =       mpls4_get_ttl,

    .change_dsfield         =       mpls4_change_dsfield,

    .get_dsfield            =       mpls4_get_dsfield,

    .ttl_expired            =       mpls4_ttl_expired,

    .mtu_exceeded        =    mpls4_mtu_exceeded,

    .local_deliver        =    mpls4_local_deliver,

    .nexthop_resolve        =       mpls4_nexthop_resolve,

    .owner                  =       THIS_MODULE,

};

15

xt_mpls 原来是netfilter

总体上，我不知道他干了什么？我猜，kernel的作用就是解释netlink发来的路由信息

FIXME