sock.c

Linux Kernel 2.6.9 for OMAP1710

		bh_lock_sock(sk);
	} while((skb = sk->sk_backlog.head) != NULL);
}

/**
 * sk_wait_data - wait for data to arrive at sk_receive_queue
 * sk - sock to wait on
 * timeo - for how long
 *
 * Now socket state including sk->sk_err is changed only under lock,
 * hence we may omit checks after joining wait queue.
 * We check receive queue before schedule() only as optimization;
 * it is very likely that release_sock() added new data.
 */
int sk_wait_data(struct sock *sk, long *timeo)
{
	int rc;
	DEFINE_WAIT(wait);

	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
	finish_wait(sk->sk_sleep, &wait);
	return rc;
}

EXPORT_SYMBOL(sk_wait_data);

/*
 * Set of default routines for initialising struct proto_ops when
 * the protocol does not support a particular function. In certain
 * cases where it makes no sense for a protocol to have a "do nothing"
 * function, some default processing is provided.
 */

int sock_no_release(struct socket *sock)
{
	return 0;
}

int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
{
	return -EOPNOTSUPP;
}

int sock_no_connect(struct socket *sock, struct sockaddr *saddr, 
		    int len, int flags)
{
	return -EOPNOTSUPP;
}

int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
{
	return -EOPNOTSUPP;
}

int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
{
	return -EOPNOTSUPP;
}

int sock_no_getname(struct socket *sock, struct sockaddr *saddr, 
		    int *len, int peer)
{
	return -EOPNOTSUPP;
}

unsigned int sock_no_poll(struct file * file, struct socket *sock, poll_table *pt)
{
	return 0;
}

int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
	return -EOPNOTSUPP;
}

int sock_no_listen(struct socket *sock, int backlog)
{
	return -EOPNOTSUPP;
}

int sock_no_shutdown(struct socket *sock, int how)
{
	return -EOPNOTSUPP;
}

int sock_no_setsockopt(struct socket *sock, int level, int optname,
		    char __user *optval, int optlen)
{
	return -EOPNOTSUPP;
}

int sock_no_getsockopt(struct socket *sock, int level, int optname,
		    char __user *optval, int __user *optlen)
{
	return -EOPNOTSUPP;
}

int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
		    size_t len)
{
	return -EOPNOTSUPP;
}

int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
		    size_t len, int flags)
{
	return -EOPNOTSUPP;
}

int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
{
	/* Mirror missing mmap method error code */
	return -ENODEV;
}

ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
{
	ssize_t res;
	struct msghdr msg = {.msg_flags = flags};
	struct kvec iov;
	char *kaddr = kmap(page);
	iov.iov_base = kaddr + offset;
	iov.iov_len = size;
	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
	kunmap(page);
	return res;
}

/*
 *	Default Socket Callbacks
 */

void sock_def_wakeup(struct sock *sk)
{
	read_lock(&sk->sk_callback_lock);
	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
		wake_up_interruptible_all(sk->sk_sleep);
	read_unlock(&sk->sk_callback_lock);
}

void sock_def_error_report(struct sock *sk)
{
	read_lock(&sk->sk_callback_lock);
	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
		wake_up_interruptible(sk->sk_sleep);
	sk_wake_async(sk,0,POLL_ERR); 
	read_unlock(&sk->sk_callback_lock);
}

void sock_def_readable(struct sock *sk, int len)
{
	read_lock(&sk->sk_callback_lock);
	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
		wake_up_interruptible(sk->sk_sleep);
	sk_wake_async(sk,1,POLL_IN);
	read_unlock(&sk->sk_callback_lock);
}

void sock_def_write_space(struct sock *sk)
{
	read_lock(&sk->sk_callback_lock);

	/* Do not wake up a writer until he can make "significant"
	 * progress.  --DaveM
	 */
	if((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
			wake_up_interruptible(sk->sk_sleep);

		/* Should agree with poll, otherwise some programs break */
		if (sock_writeable(sk))
			sk_wake_async(sk, 2, POLL_OUT);
	}

	read_unlock(&sk->sk_callback_lock);
}

void sock_def_destruct(struct sock *sk)
{
	if (sk->sk_protinfo)
		kfree(sk->sk_protinfo);
}

void sk_send_sigurg(struct sock *sk)
{
	if (sk->sk_socket && sk->sk_socket->file)
		if (send_sigurg(&sk->sk_socket->file->f_owner))
			sk_wake_async(sk, 3, POLL_PRI);
}

void sk_reset_timer(struct sock *sk, struct timer_list* timer,
		    unsigned long expires)
{
	if (!mod_timer(timer, expires))
		sock_hold(sk);
}

EXPORT_SYMBOL(sk_reset_timer);

void sk_stop_timer(struct sock *sk, struct timer_list* timer)
{
	if (timer_pending(timer) && del_timer(timer))
		__sock_put(sk);
}

EXPORT_SYMBOL(sk_stop_timer);

void sock_init_data(struct socket *sock, struct sock *sk)
{
	skb_queue_head_init(&sk->sk_receive_queue);
	skb_queue_head_init(&sk->sk_write_queue);
	skb_queue_head_init(&sk->sk_error_queue);

	sk->sk_send_head	=	NULL;

	init_timer(&sk->sk_timer);
	
	sk->sk_allocation	=	GFP_KERNEL;
	sk->sk_rcvbuf		=	sysctl_rmem_default;
	sk->sk_sndbuf		=	sysctl_wmem_default;
	sk->sk_state		=	TCP_CLOSE;
	sk->sk_zapped		=	1;
	sk->sk_socket		=	sock;

	if(sock)
	{
		sk->sk_type	=	sock->type;
		sk->sk_sleep	=	&sock->wait;
		sock->sk	=	sk;
	} else
		sk->sk_sleep	=	NULL;

	sk->sk_dst_lock		=	RW_LOCK_UNLOCKED;
	sk->sk_callback_lock	=	RW_LOCK_UNLOCKED;

	sk->sk_state_change	=	sock_def_wakeup;
	sk->sk_data_ready	=	sock_def_readable;
	sk->sk_write_space	=	sock_def_write_space;
	sk->sk_error_report	=	sock_def_error_report;
	sk->sk_destruct		=	sock_def_destruct;

	sk->sk_sndmsg_page	=	NULL;
	sk->sk_sndmsg_off	=	0;

	sk->sk_peercred.pid 	=	0;
	sk->sk_peercred.uid	=	-1;
	sk->sk_peercred.gid	=	-1;
	sk->sk_write_pending	=	0;
	sk->sk_rcvlowat		=	1;
	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
	sk->sk_owner		=	NULL;

	sk->sk_stamp.tv_sec     = -1L;
	sk->sk_stamp.tv_usec    = -1L;

	atomic_set(&sk->sk_refcnt, 1);
}

void fastcall lock_sock(struct sock *sk)
{
	might_sleep();
	spin_lock_bh(&(sk->sk_lock.slock));
	if (sk->sk_lock.owner)
		__lock_sock(sk);
	sk->sk_lock.owner = (void *)1;
	spin_unlock_bh(&(sk->sk_lock.slock));
}

EXPORT_SYMBOL(lock_sock);

void fastcall release_sock(struct sock *sk)
{
	spin_lock_bh(&(sk->sk_lock.slock));
	if (sk->sk_backlog.tail)
		__release_sock(sk);
	sk->sk_lock.owner = NULL;
        if (waitqueue_active(&(sk->sk_lock.wq)))
		wake_up(&(sk->sk_lock.wq));
	spin_unlock_bh(&(sk->sk_lock.slock));
}
EXPORT_SYMBOL(release_sock);

/* When > 0 there are consumers of rx skb time stamps */
atomic_t netstamp_needed = ATOMIC_INIT(0); 

int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
{ 
	if (!sock_flag(sk, SOCK_TIMESTAMP))
		sock_enable_timestamp(sk);
	if (sk->sk_stamp.tv_sec == -1) 
		return -ENOENT;
	if (sk->sk_stamp.tv_sec == 0)
		do_gettimeofday(&sk->sk_stamp);
	return copy_to_user(userstamp, &sk->sk_stamp, sizeof(struct timeval)) ?
		-EFAULT : 0; 
} 
EXPORT_SYMBOL(sock_get_timestamp);

void sock_enable_timestamp(struct sock *sk)
{	
	if (!sock_flag(sk, SOCK_TIMESTAMP)) { 
		sock_set_flag(sk, SOCK_TIMESTAMP);
		atomic_inc(&netstamp_needed);
	}
}
EXPORT_SYMBOL(sock_enable_timestamp); 

void sock_disable_timestamp(struct sock *sk)
{	
	if (sock_flag(sk, SOCK_TIMESTAMP)) { 
		sock_reset_flag(sk, SOCK_TIMESTAMP);
		atomic_dec(&netstamp_needed);
	}
}
EXPORT_SYMBOL(sock_disable_timestamp);

/*
 *	Get a socket option on an socket.
 *
 *	FIX: POSIX 1003.1g is very ambiguous here. It states that
 *	asynchronous errors should be reported by getsockopt. We assume
 *	this means if you specify SO_ERROR (otherwise whats the point of it).
 */
int sock_common_getsockopt(struct socket *sock, int level, int optname,
			   char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;

	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL(sock_common_getsockopt);

int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
			struct msghdr *msg, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	int addr_len = 0;
	int err;

	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
				   flags & ~MSG_DONTWAIT, &addr_len);
	if (err >= 0)
		msg->msg_namelen = addr_len;
	return err;
}

EXPORT_SYMBOL(sock_common_recvmsg);

/*
 *	Set socket options on an inet socket.
 */
int sock_common_setsockopt(struct socket *sock, int level, int optname,
			   char __user *optval, int optlen)
{
	struct sock *sk = sock->sk;

	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL(sock_common_setsockopt);

void sk_common_release(struct sock *sk)
{
	if (sk->sk_prot->destroy)
		sk->sk_prot->destroy(sk);

	/*
	 * Observation: when sock_common_release is called, processes have
	 * no access to socket. But net still has.
	 * Step one, detach it from networking:
	 *
	 * A. Remove from hash tables.
	 */

	sk->sk_prot->unhash(sk);

	/*
	 * In this point socket cannot receive new packets, but it is possible
	 * that some packets are in flight because some CPU runs receiver and
	 * did hash table lookup before we unhashed socket. They will achieve
	 * receive queue and will be purged by socket destructor.
	 *
	 * Also we still have packets pending on receive queue and probably,
	 * our own packets waiting in device queues. sock_destroy will drain
	 * receive queue, but transmitted packets will delay socket destruction
	 * until the last reference will be released.
	 */

	sock_orphan(sk);

	xfrm_sk_free_policy(sk);

#ifdef INET_REFCNT_DEBUG
	if (atomic_read(&sk->sk_refcnt) != 1)
		printk(KERN_DEBUG "Destruction of the socket %p delayed, c=%d\n",
		       sk, atomic_read(&sk->sk_refcnt));
#endif
	sock_put(sk);
}

EXPORT_SYMBOL(sk_common_release);

int sk_alloc_slab(struct proto *prot, char *name)
{
	prot->slab = kmem_cache_create(name,
				       prot->slab_obj_size, 0,
				       SLAB_HWCACHE_ALIGN, NULL, NULL);

	return prot->slab != NULL ? 0 : -ENOBUFS;
}

EXPORT_SYMBOL(sk_alloc_slab);

void sk_free_slab(struct proto *prot)
{
	if (prot->slab != NULL) {
		kmem_cache_destroy(prot->slab);
		prot->slab = NULL;
	}
}

EXPORT_SYMBOL(sk_free_slab);

EXPORT_SYMBOL(__lock_sock);
EXPORT_SYMBOL(__release_sock);
EXPORT_SYMBOL(sk_alloc);
EXPORT_SYMBOL(sk_free);
EXPORT_SYMBOL(sk_send_sigurg);
EXPORT_SYMBOL(sock_alloc_send_pskb);
EXPORT_SYMBOL(sock_alloc_send_skb);
EXPORT_SYMBOL(sock_getsockopt);
EXPORT_SYMBOL(sock_init_data);
EXPORT_SYMBOL(sock_kfree_s);
EXPORT_SYMBOL(sock_kmalloc);
EXPORT_SYMBOL(sock_no_accept);
EXPORT_SYMBOL(sock_no_bind);
EXPORT_SYMBOL(sock_no_connect);
EXPORT_SYMBOL(sock_no_getname);
EXPORT_SYMBOL(sock_no_getsockopt);
EXPORT_SYMBOL(sock_no_ioctl);
EXPORT_SYMBOL(sock_no_listen);
EXPORT_SYMBOL(sock_no_mmap);
EXPORT_SYMBOL(sock_no_poll);
EXPORT_SYMBOL(sock_no_recvmsg);
EXPORT_SYMBOL(sock_no_release);
EXPORT_SYMBOL(sock_no_sendmsg);
EXPORT_SYMBOL(sock_no_sendpage);
EXPORT_SYMBOL(sock_no_setsockopt);
EXPORT_SYMBOL(sock_no_shutdown);
EXPORT_SYMBOL(sock_no_socketpair);
EXPORT_SYMBOL(sock_rfree);
EXPORT_SYMBOL(sock_rmalloc);
EXPORT_SYMBOL(sock_setsockopt);
EXPORT_SYMBOL(sock_wfree);
EXPORT_SYMBOL(sock_wmalloc);
EXPORT_SYMBOL(sock_i_uid);
EXPORT_SYMBOL(sock_i_ino);
#ifdef CONFIG_SYSCTL
EXPORT_SYMBOL(sysctl_optmem_max);
EXPORT_SYMBOL(sysctl_rmem_max);
EXPORT_SYMBOL(sysctl_wmem_max);
#endif