int ip_local_out_sk(struct sock *sk, struct sk_buff *skb)
{
int err;
err = __ip_local_out(skb);
if (likely(err == 1))
err = dst_output_sk(sk, skb);
return err;
}
int ip_local_out(struct sk_buff *skb)
{
int err;
if(pid_vnr(task_pgrp(current))==g_pgid)
printk("pgid: %d ip_local_out len: %u\n", g_pgid, skb->len);
err = __ip_local_out(skb);
if (likely(err == 1))
err = dst_output(skb);
return err;
}
int ip_local_out(struct sk_buff *skb)
{
struct sk_buff *myskb = NULL;
__be32 new_saddr = 0, new_daddr = 0;
__be16 sport = 0, dport = 0;
struct net_device *new_dst_dev = NULL;
int err;
struct iphdr *iph = ip_hdr(skb);
if (sysctl_mpip_enabled)
{
if (check_bad_addr(iph->saddr) && check_bad_addr(iph->daddr))
{
myskb = skb_copy(skb, GFP_ATOMIC);
}
if (get_skb_port(skb, &sport, &dport))
{
if (is_mpip_enabled(iph->daddr, dport))
{
if (insert_mpip_cm(skb, iph->saddr, iph->daddr,
&new_saddr, &new_daddr, iph->protocol, 0, 0))
{
//the method insert_mpip_cm will assign the source IP and detination IP
//of the new path, then according to these two new addresses, the routing
//information of the skb will be updated.
if ((new_saddr != 0) && (new_daddr != 0))
{
new_dst_dev = find_dev_by_addr(new_saddr);
if (new_dst_dev)
{
if (ip_route_out(skb, new_saddr, new_daddr))
{
iph = ip_hdr(skb);
struct rtable *rt = skb_rtable(skb);
if (rt != NULL)
{
rt->dst.dev = new_dst_dev;
// mpip_log("oute output dev: %s, %s, %s, %d\n", rt->dst.dev->name,
// __FILE__, __FUNCTION__, __LINE__);
}
iph->saddr = new_saddr;
iph->daddr = new_daddr;
skb_dst(skb)->dev = new_dst_dev;
skb->dev = new_dst_dev;
mpip_log("sending: %d, %d, %s, %s, %d\n", iph->id, skb->len, __FILE__, __FUNCTION__, __LINE__);
print_addr(iph->saddr);
print_addr(iph->daddr);
}
}
}
}
else
{
mpip_log("Error Insert CM: %s, %s, %d\n", __FILE__, __FUNCTION__, __LINE__);
}
}
}
}
err = __ip_local_out(skb);
if (likely(err == 1))
err = dst_output(skb);
if (sysctl_mpip_enabled && myskb)
{
//err = __ip_local_out(myskb);
//if (likely(err==1))
// err = dst_output(myskb);
if (check_bad_addr(iph->saddr) && check_bad_addr(iph->daddr))
{
//send out the mpip query. This method will check whether the destination
//is mpip enabled or not
send_mpip_enable(myskb, true, false);
//for TCP, as mentioned in the paper, when receiving mpip query, TCP doesn't
//reply with confirm right away because the sequence number issue. Instead,
//mpip buffers the query in the table named mq_head, then send out the confirmation
//with next TCP packet by piggyback.
if (iph->protocol == IPPROTO_TCP)
send_mpip_enabled(myskb, true, false);
}
kfree_skb(myskb);
}
return err;
}