rtnetlink.c

一个基于linux的TCP/IP协议栈的实现

/* rtnetlink.c
 * [e-mail]
 * 2006-10-30
 */

#include "rtnetlink.h"
#include "neighbour.h"
#include "log.h"

#include <linux/string.h>
#include <linux/netlink.h>
#include <net/sock.h>

static struct rtattr **rta_buf;
static int myrtattr_max;

struct sock *rtnl;
struct rtnetlink_link * myrtnetlink_links[NPROTO];

static void myrtnetlink_rcv(struct sock *sk, int len)
{
/*
	unsigned int qlen = 0;

	do {
		rtnl_lock();
		netlink_run_queue(sk, &qlen, &rtnetlink_rcv_msg);
		up(&rtnl_sem);

		netdev_run_todo();
	} while (qlen);
*/
}

static int myrtnetlink_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
{
	return 0;
}

static int mydo_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	return 0;
}

static int myrtnetlink_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
{
	return 0;
}

static struct rtnetlink_link mylink_rtnetlink_table[RTM_NR_MSGTYPES] =
{
	[RTM_GETLINK     - RTM_BASE] = { .dumpit = myrtnetlink_dump_ifinfo },
	[RTM_SETLINK     - RTM_BASE] = { .doit   = mydo_setlink		 },
	[RTM_GETADDR     - RTM_BASE] = { .dumpit = myrtnetlink_dump_all	 },
	[RTM_GETROUTE    - RTM_BASE] = { .dumpit = myrtnetlink_dump_all	 },
	[RTM_NEWNEIGH    - RTM_BASE] = { .doit   = myneigh_add		 },
	[RTM_DELNEIGH    - RTM_BASE] = { .doit   = myneigh_delete		 },
	[RTM_GETNEIGH    - RTM_BASE] = { .dumpit = myneigh_dump_info	 },
	[RTM_GETRULE     - RTM_BASE] = { .dumpit = myrtnetlink_dump_all	 },
	[RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = myneightbl_dump_info	 },
	[RTM_SETNEIGHTBL - RTM_BASE] = { .doit   = myneightbl_set		 },
};

static const int myrta_max[RTM_NR_FAMILIES] =
{
	[RTM_FAM(RTM_NEWLINK)]      = IFLA_MAX,
	[RTM_FAM(RTM_NEWADDR)]      = IFA_MAX,
	[RTM_FAM(RTM_NEWROUTE)]     = RTA_MAX,
	[RTM_FAM(RTM_NEWNEIGH)]     = NDA_MAX,
	[RTM_FAM(RTM_NEWRULE)]      = RTA_MAX,
	[RTM_FAM(RTM_NEWQDISC)]     = TCA_MAX,
	[RTM_FAM(RTM_NEWTCLASS)]    = TCA_MAX,
	[RTM_FAM(RTM_NEWTFILTER)]   = TCA_MAX,
	[RTM_FAM(RTM_NEWACTION)]    = TCAA_MAX,
	[RTM_FAM(RTM_NEWNEIGHTBL)]  = NDTA_MAX,
};

void __init myrtnetlink_init(void)
{
	int i;

	myrtattr_max = 0;
	for (i = 0; i < ARRAY_SIZE( myrta_max ); i++)
		if( myrta_max[i] > myrtattr_max )
			myrtattr_max = myrta_max[i];
	rta_buf = kmalloc( myrtattr_max * sizeof(struct rtattr *), GFP_KERNEL );
	if (!rta_buf)
		panic("rtnetlink_init: cannot allocate rta_buf\n");
	rtnl = netlink_kernel_create( MY_NETLINK_ROUTE, RTNLGRP_MAX, myrtnetlink_rcv, THIS_MODULE );
	if( rtnl == NULL )
		panic("rtnetlink_init: cannot initialize rtnetlink\n");
	netlink_set_nonroot( MY_NETLINK_ROUTE, NL_NONROOT_RECV );

	myrtnetlink_links[PF_UNSPEC] = mylink_rtnetlink_table;
	myrtnetlink_links[PF_PACKET] = mylink_rtnetlink_table;
}

void __exit myrtnetlink_exit(void)
{
	if( rtnl )
		rtnl->sk_socket->ops->release( rtnl->sk_socket );
	if( rta_buf )
		kfree( rta_buf );
}