static int
ip_proto_bind (struct socket *sock, struct sockaddr *uaddr,
int addr_len)
{
struct sockaddr_in addr;
volatile struct sock *sk, *sk2;
unsigned short snum;
sk = sock->data;
if (sk == NULL)
{
printk ("Warning: sock->data = NULL: %d\n" ,__LINE__);
return (0);
}
/* check this error. */
if (sk->state != TCP_CLOSE) return (-EIO);
verify_area (uaddr, addr_len);
memcpy_fromfs (&addr, uaddr, min (sizeof (addr), addr_len));
if (addr.sin_family && addr.sin_family != AF_INET)
return (-EIO); /* this needs to be changed. */
snum = net16(addr.sin_port);
PRINTK ("bind sk =%X to port = %d\n", sk, snum);
print_sk (sk);
sk = sock->data;
/* we can't just leave the socket bound wherever it is, it might be bound
to a priveledged port. However, since there seems to be a bug here,
we will leave it if the port is not priveledged(sp?) */
if (snum == 0)
{
if ( sk->num > PROT_SOCK) return (0);
snum = get_new_socknum (sk->prot, 0);
}
if (snum <= PROT_SOCK && !suser())
return (-EPERM);
if (my_ip_addr(addr.sin_addr.s_addr) || addr.sin_addr.s_addr == 0)
sk->saddr = addr.sin_addr.s_addr;
PRINTK ("sock_array[%d] = %X:\n", snum & (SOCK_ARRAY_SIZE -1),
sk->prot->sock_array[snum & (SOCK_ARRAY_SIZE -1)]);
print_sk (sk->prot->sock_array[snum & (SOCK_ARRAY_SIZE -1)]);
/* make sure we are allowed to bind here. */
for (sk2 = sk->prot->sock_array[snum & (SOCK_ARRAY_SIZE -1)];
sk2 != NULL;
sk2 = sk2->next)
{
if (sk2->num != snum) continue;
if (sk2->saddr != sk->saddr) continue;
if (!sk->reuse) return (-EADDRINUSE);
if (!sk2->reuse) return (-EADDRINUSE);
}
remove_sock (sk);
put_sock(snum, sk);
sk->dummy_th.source = net16(sk->num);
sk->daddr = 0;
sk->dummy_th.dest = 0;
return (0);
}
static inline bool check_sock(void *data)
{
Sock *sock = (Sock*)data;
if((curr_time - sock->last_pack_time) >= SOCK_TIME_OUT)
{
remove_sock(sock, true);
return true;
}
return false;
}
static int inet_bind(struct socket *sock, struct sockaddr *uaddr,
int addr_len)
{
struct sockaddr_in *addr=(struct sockaddr_in *)uaddr;
struct sock *sk=(struct sock *)sock->data, *sk2;
unsigned short snum = 0 /* Stoopid compiler.. this IS ok */;
int chk_addr_ret;
/* check this error. */
if (sk->state != TCP_CLOSE)
return(-EIO);
if(addr_len<sizeof(struct sockaddr_in))
return -EINVAL;
if(sock->type != SOCK_RAW)
{
/* 验证sk已经加入到对应传输层协议的管理结构中 */
if (sk->num != 0)
return(-EINVAL);
snum = ntohs(addr->sin_port);
/*
* We can't just leave the socket bound wherever it is, it might
* be bound to a privileged port. However, since there seems to
* be a bug here, we will leave it if the port is not privileged.
*/
if (snum == 0)
{
snum = get_new_socknum(sk->prot, 0);
}
if (snum < PROT_SOCK && !suser())
return(-EACCES);
}
chk_addr_ret = ip_chk_addr(addr->sin_addr.s_addr);
if (addr->sin_addr.s_addr != 0 && chk_addr_ret != IS_MYADDR && chk_addr_ret != IS_MULTICAST)
return(-EADDRNOTAVAIL); /* Source address MUST be ours! */
if (chk_addr_ret || addr->sin_addr.s_addr == 0)
sk->saddr = addr->sin_addr.s_addr;
if(sock->type != SOCK_RAW)
{
/* Make sure we are allowed to bind here. */
cli();
for(sk2 = sk->prot->sock_array[snum & (SOCK_ARRAY_SIZE -1)];
sk2 != NULL; sk2 = sk2->next)
{
/* should be below! */
if (sk2->num != snum)
continue;
if (!sk->reuse)
{
sti();
return(-EADDRINUSE);
}
if (sk2->num != snum)
continue; /* more than one */
if (sk2->saddr != sk->saddr)
continue; /* socket per slot ! -FB */
if (!sk2->reuse || sk2->state==TCP_LISTEN)
{
sti();
return(-EADDRINUSE);
}
}
sti();
remove_sock(sk);
put_sock(snum, sk);
sk->dummy_th.source = ntohs(sk->num);
sk->daddr = 0;
sk->dummy_th.dest = 0;
}
return(0);
}
void destroy_sock(struct sock *sk)
{
struct sk_buff *skb;
sk->inuse = 1; /* just to be safe.对sock结构上锁 */
/* 首先检查dead标志，只有dead=1时才表示sock结构等待释放 */
/* In case it's sleeping somewhere. */
if (!sk->dead)
sk->write_space(sk); // sock如果出现SO_NOSPACE标志，需要唤醒异步等待sock的进程
remove_sock(sk);
/* 移除sock连接使用的定时器 */
/* Now we can no longer get new packets. */
delete_timer(sk); // 移除通用定时器
/* Nor send them */
del_timer(&sk->retransmit_timer); // 移除重传定时器
/* 释放sock::partial指向的数据写缓冲 */
while ((skb = tcp_dequeue_partial(sk)) != NULL) {
IS_SKB(skb);
kfree_skb(skb, FREE_WRITE);
}
/* Cleanup up the write buffer. */
while((skb = skb_dequeue(&sk->write_queue)) != NULL) {
IS_SKB(skb);
kfree_skb(skb, FREE_WRITE);
}
/*
* Don't discard received data until the user side kills its
* half of the socket.
*/
if (sk->dead)
{
while((skb=skb_dequeue(&sk->receive_queue))!=NULL)
{
/*
* This will take care of closing sockets that were
* listening and didn't accept everything.
*/
if (skb->sk != NULL && skb->sk != sk)
{
/* 如果当前sock对应一个listen socket就需要关闭尚未完成创建的socket连接
* 这其中的sock可能是establish或者syn_recv状态 */
IS_SKB(skb);
skb->sk->dead = 1;
skb->sk->prot->close(skb->sk, 0);
}
IS_SKB(skb);
kfree_skb(skb, FREE_READ);
}
}
/* Now we need to clean up the send head. 清理重发队列 */
cli();
for(skb = sk->send_head; skb != NULL; )
{
struct sk_buff *skb2;
/*
* We need to remove skb from the transmit queue,
* or maybe the arp queue.
*/
if (skb->next && skb->prev) {
/* printk("destroy_sock: unlinked skb\n");*/
IS_SKB(skb);
skb_unlink(skb);
}
skb->dev = NULL;
skb2 = skb->link3; // link3在TCP中构建重发队列
kfree_skb(skb, FREE_WRITE);
skb = skb2;
}
sk->send_head = NULL;
sti();
/* And now the backlog. */
while((skb=skb_dequeue(&sk->back_log))!=NULL)
{
/* this should never happen. */
/* printk("cleaning back_log\n");*/
kfree_skb(skb, FREE_READ);
}
/* Now if it has a half accepted/ closed socket. */
if (sk->pair)
{
sk->pair->dead = 1;
sk->pair->prot->close(sk->pair, 0);
sk->pair = NULL;
}
/*
* Now if everything is gone we can free the socket
* structure, otherwise we need to keep it around until
* everything is gone.
*/
if (sk->dead && sk->rmem_alloc == 0 && sk->wmem_alloc == 0)
{
kfree_s((void *)sk,sizeof(*sk));
}
else
{
/* this should never happen. */
/* actually it can if an ack has just been sent. */
sk->destroy = 1;
sk->ack_backlog = 0;
sk->inuse = 0;
reset_timer(sk, TIME_DESTROY, SOCK_DESTROY_TIME);
}
}
void
destroy_sock(volatile struct sock *sk)
{
struct sk_buff *skb;
PRINTK ("destroying socket %X\n",sk);
/* just to be safe. */
sk->inuse = 1;
remove_sock (sk);
/* now we can no longer get new packets. */
delete_timer((struct timer *)&sk->time_wait);
/* cleanup up the write buffer. */
for (skb = sk->wfront; skb != NULL; )
{
struct sk_buff *skb2;
skb2=skb->next;
free_skb(skb, FREE_WRITE);
skb=skb2;
}
sk->wfront = NULL;
if (sk->rqueue != NULL)
{
skb = sk->rqueue;
do {
struct sk_buff *skb2;
skb2=skb->next;
/* this will take care of closing sockets that were
listening and didn't accept everything. */
if (skb->sk != NULL && skb->sk != sk)
{
skb->sk->dead = 1;
skb->sk->prot->close (skb->sk, 0);
}
free_skb(skb, FREE_READ);
skb=skb2;
} while (skb != sk->rqueue);
}
sk->rqueue = NULL;
/* now we need to clean up the send head. */
for (skb = sk->send_head; skb != NULL; )
{
struct sk_buff *skb2;
/* we need to remove skb from the transmit queue. */
cli();
/* see if it's in a transmit queue. */
if (skb->next != NULL)
{
if (skb->next != skb)
{
skb->next->prev = skb->prev;
skb->prev->next = skb->next;
}
else
{
int i;
for (i = 0; i < DEV_NUMBUFFS; i++)
{
if (skb->dev && skb->dev->buffs[i] == skb)
{
skb->dev->buffs[i]= NULL;
break;
}
}
}
}
sti();
skb2=skb->link3;
free_skb(skb, FREE_WRITE);
skb=skb2;
}
sk->send_head = NULL;
/* and now the backlog. */
if (sk->back_log != NULL)
{
/* this should never happen. */
printk ("cleaning back_log. \n");
cli();
skb = sk->back_log;
do {
struct sk_buff *skb2;
skb2=skb->next;
free_skb(skb, FREE_READ);
skb=skb2;
} while (skb != sk->back_log);
sti();
}
sk->back_log = NULL;
/* now if everything is gone we can free the socket structure,
otherwise we need to keep it around until everything is gone. */
if (sk->rmem_alloc == 0 && sk->wmem_alloc == 0)
{
free_s ((void *)sk,sizeof (*sk));
}
else
{
/* this should never happen. */
/* actually it can if an ack has just been sent. */
PRINTK ("possible memory leak in socket = %X\n", sk);
print_sk (sk);
sk->destroy = 1;
sk->ack_backlog = 0;
sk->inuse = 0;
sk->time_wait.len = SOCK_DESTROY_TIME;
sk->timeout = TIME_DESTROY;
reset_timer ((struct timer *)&sk->time_wait);
}
}
