socket.c

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	msg.msg_name=NULL;
	msg.msg_namelen=0;
	msg.msg_iov=&iov;
	msg.msg_iovlen=1;
	msg.msg_control=NULL;
	msg.msg_controllen=0;
	msg.msg_flags=!(file->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
	if (sock->type == SOCK_SEQPACKET)
		msg.msg_flags |= MSG_EOR;
	iov.iov_base=(void *)ubuf;
	iov.iov_len=size;
	
	return sock_sendmsg(sock, &msg, size);
}

ssize_t sock_sendpage(struct file *file, struct page *page,
		      int offset, size_t size, loff_t *ppos, int more)
{
	struct socket *sock;
	int flags;

	if (ppos != &file->f_pos)
		return -ESPIPE;

	sock = socki_lookup(file->f_dentry->d_inode);

	flags = !(file->f_flags & O_NONBLOCK) ? 0 : MSG_DONTWAIT;
	if (more)
		flags |= MSG_MORE;

	return sock->ops->sendpage(sock, page, offset, size, flags);
}

int sock_readv_writev(int type, struct inode * inode, struct file * file,
		      const struct iovec * iov, long count, long size)
{
	struct msghdr msg;
	struct socket *sock;

	sock = socki_lookup(inode);

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = NULL;
	msg.msg_controllen = 0;
	msg.msg_iov = (struct iovec *) iov;
	msg.msg_iovlen = count;
	msg.msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;

	/* read() does a VERIFY_WRITE */
	if (type == VERIFY_WRITE)
		return sock_recvmsg(sock, &msg, size, msg.msg_flags);

	if (sock->type == SOCK_SEQPACKET)
		msg.msg_flags |= MSG_EOR;

	return sock_sendmsg(sock, &msg, size);
}

static ssize_t sock_readv(struct file *file, const struct iovec *vector,
			  unsigned long count, loff_t *ppos)
{
	size_t tot_len = 0;
	int i;
        for (i = 0 ; i < count ; i++)
                tot_len += vector[i].iov_len;
	return sock_readv_writev(VERIFY_WRITE, file->f_dentry->d_inode,
				 file, vector, count, tot_len);
}
	
static ssize_t sock_writev(struct file *file, const struct iovec *vector,
			   unsigned long count, loff_t *ppos)
{
	size_t tot_len = 0;
	int i;
        for (i = 0 ; i < count ; i++)
                tot_len += vector[i].iov_len;
	return sock_readv_writev(VERIFY_READ, file->f_dentry->d_inode,
				 file, vector, count, tot_len);
}

/*
 *	With an ioctl arg may well be a user mode pointer, but we don't know what to do
 *	with it - that's up to the protocol still.
 */

int sock_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
	   unsigned long arg)
{
	struct socket *sock;
	int err;

	unlock_kernel();
	sock = socki_lookup(inode);
	err = sock->ops->ioctl(sock, cmd, arg);
	lock_kernel();

	return err;
}


/* No kernel lock held - perfect */
static unsigned int sock_poll(struct file *file, poll_table * wait)
{
	struct socket *sock;

	/*
	 *	We can't return errors to poll, so it's either yes or no. 
	 */
	sock = socki_lookup(file->f_dentry->d_inode);
	return sock->ops->poll(file, sock, wait);
}

static int sock_mmap(struct file * file, struct vm_area_struct * vma)
{
	struct socket *sock = socki_lookup(file->f_dentry->d_inode);

	return sock->ops->mmap(file, sock, vma);
}

int sock_close(struct inode *inode, struct file *filp)
{
	/*
	 *	It was possible the inode is NULL we were 
	 *	closing an unfinished socket. 
	 */

	if (!inode)
	{
		printk(KERN_DEBUG "sock_close: NULL inode\n");
		return 0;
	}
	sock_fasync(-1, filp, 0);
	sock_release(socki_lookup(inode));
	return 0;
}

/*
 *	Update the socket async list
 *
 *	Fasync_list locking strategy.
 *
 *	1. fasync_list is modified only under process context socket lock
 *	   i.e. under semaphore.
 *	2. fasync_list is used under read_lock(&sk->callback_lock)
 *	   or under socket lock.
 *	3. fasync_list can be used from softirq context, so that
 *	   modification under socket lock have to be enhanced with
 *	   write_lock_bh(&sk->callback_lock).
 *							--ANK (990710)
 */

static int sock_fasync(int fd, struct file *filp, int on)
{
	struct fasync_struct *fa, *fna=NULL, **prev;
	struct socket *sock;
	struct sock *sk;

	if (on)
	{
		fna=(struct fasync_struct *)kmalloc(sizeof(struct fasync_struct), GFP_KERNEL);
		if(fna==NULL)
			return -ENOMEM;
	}


	sock = socki_lookup(filp->f_dentry->d_inode);
	
	if ((sk=sock->sk) == NULL)
		return -EINVAL;

	lock_sock(sk);

	prev=&(sock->fasync_list);

	for (fa=*prev; fa!=NULL; prev=&fa->fa_next,fa=*prev)
		if (fa->fa_file==filp)
			break;

	if(on)
	{
		if(fa!=NULL)
		{
			write_lock_bh(&sk->callback_lock);
			fa->fa_fd=fd;
			write_unlock_bh(&sk->callback_lock);

			kfree(fna);
			goto out;
		}
		fna->fa_file=filp;
		fna->fa_fd=fd;
		fna->magic=FASYNC_MAGIC;
		fna->fa_next=sock->fasync_list;
		write_lock_bh(&sk->callback_lock);
		sock->fasync_list=fna;
		write_unlock_bh(&sk->callback_lock);
	}
	else
	{
		if (fa!=NULL)
		{
			write_lock_bh(&sk->callback_lock);
			*prev=fa->fa_next;
			write_unlock_bh(&sk->callback_lock);
			kfree(fa);
		}
	}

out:
	release_sock(sock->sk);
	return 0;
}

/* This function may be called only under socket lock or callback_lock */

int sock_wake_async(struct socket *sock, int how, int band)
{
	if (!sock || !sock->fasync_list)
		return -1;
	switch (how)
	{
	case 1:
		
		if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
			break;
		goto call_kill;
	case 2:
		if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags))
			break;
		/* fall through */
	case 0:
	call_kill:
		__kill_fasync(sock->fasync_list, SIGIO, band);
		break;
	case 3:
		__kill_fasync(sock->fasync_list, SIGURG, band);
	}
	return 0;
}


int sock_create(int family, int type, int protocol, struct socket **res)
{
	int i;
	struct socket *sock;

	/*
	 *	Check protocol is in range
	 */
	if (family < 0 || family >= NPROTO)
		return -EAFNOSUPPORT;
	if (type < 0 || type >= SOCK_MAX)
		return -EINVAL;

	/* Compatibility.

	   This uglymoron is moved from INET layer to here to avoid
	   deadlock in module load.
	 */
	if (family == PF_INET && type == SOCK_PACKET) {
		static int warned; 
		if (!warned) {
			warned = 1;
			printk(KERN_INFO "%s uses obsolete (PF_INET,SOCK_PACKET)\n", current->comm);
		}
		family = PF_PACKET;
	}
		
#if defined(CONFIG_KMOD) && defined(CONFIG_NET)
	/* Attempt to load a protocol module if the find failed. 
	 * 
	 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user 
	 * requested real, full-featured networking support upon configuration.
	 * Otherwise module support will break!
	 */
	if (net_families[family]==NULL)
	{
		char module_name[30];
		sprintf(module_name,"net-pf-%d",family);
		request_module(module_name);
	}
#endif

	net_family_read_lock();
	if (net_families[family] == NULL) {
		i = -EAFNOSUPPORT;
		goto out;
	}

/*
 *	Allocate the socket and allow the family to set things up. if
 *	the protocol is 0, the family is instructed to select an appropriate
 *	default.
 */

	if (!(sock = sock_alloc())) 
	{
		printk(KERN_WARNING "socket: no more sockets\n");
		i = -ENFILE;		/* Not exactly a match, but its the
					   closest posix thing */
		goto out;
	}

	sock->type  = type;

	if ((i = net_families[family]->create(sock, protocol)) < 0) 
	{
		sock_release(sock);
		goto out;
	}

	*res = sock;

out:
	net_family_read_unlock();
	return i;
}

asmlinkage long sys_socket(int family, int type, int protocol)
{
	int retval;
	struct socket *sock;

	retval = sock_create(family, type, protocol, &sock);
	if (retval < 0)
		goto out;

	retval = sock_map_fd(sock);
	if (retval < 0)
		goto out_release;

out:
	/* It may be already another descriptor 8) Not kernel problem. */
	return retval;

out_release:
	sock_release(sock);
	return retval;
}

/*
 *	Create a pair of connected sockets.
 */

asmlinkage long sys_socketpair(int family, int type, int protocol, int usockvec[2])
{
	struct socket *sock1, *sock2;
	int fd1, fd2, err;

	/*
	 * Obtain the first socket and check if the underlying protocol
	 * supports the socketpair call.
	 */

	err = sock_create(family, type, protocol, &sock1);
	if (err < 0)
		goto out;

	err = sock_create(family, type, protocol, &sock2);
	if (err < 0)
		goto out_release_1;

	err = sock1->ops->socketpair(sock1, sock2);
	if (err < 0) 
		goto out_release_both;

	fd1 = fd2 = -1;

	err = sock_map_fd(sock1);
	if (err < 0)
		goto out_release_both;
	fd1 = err;

	err = sock_map_fd(sock2);
	if (err < 0)
		goto out_close_1;
	fd2 = err;

	/* fd1 and fd2 may be already another descriptors.
	 * Not kernel problem.
	 */

	err = put_user(fd1, &usockvec[0]); 
	if (!err)
		err = put_user(fd2, &usockvec[1]);
	if (!err)
		return 0;

	sys_close(fd2);
	sys_close(fd1);
	return err;

out_close_1:
        sock_release(sock2);
	sys_close(fd1);
	return err;

out_release_both:
        sock_release(sock2);
out_release_1:
        sock_release(sock1);
out:
	return err;
}


/*
 *	Bind a name to a socket. Nothing much to do here since it's
 *	the protocol's responsibility to handle the local address.
 *
 *	We move the socket address to kernel space before we call
 *	the protocol layer (having also checked the address is ok).
 */

asmlinkage long sys_bind(int fd, struct sockaddr *umyaddr, int addrlen)
{
	struct socket *sock;
	char address[MAX_SOCK_ADDR];
	int err;

	if((sock = sockfd_lookup(fd,&err))!=NULL)
	{
		if((err=move_addr_to_kernel(umyaddr,addrlen,address))>=0)
			err = sock->ops->bind(sock, (struct sockaddr *)address, addrlen);
		sockfd_put(sock);
	}			
	return err;
}


/*
 *	Perform a listen. Basically, we allow the protocol to do anything
 *	necessary for a listen, and if that works, we mark the socket as
 *	ready for listening.
 */

asmlinkage long sys_listen(int fd, int backlog)
{
	struct socket *sock;
	int err;
	
	if ((sock = sockfd_lookup(fd, &err)) != NULL) {
		if ((unsigned) backlog > SOMAXCONN)
			backlog = SOMAXCONN;
		err=sock->ops->listen(sock, backlog);
		sockfd_put(sock);
	}
	return err;
}


/*
 *	For accept, we attempt to create a new socket, set up the link
 *	with the client, wake up the client, then return the new
 *	connected fd. We collect the address of the connector in kernel
 *	space and move it to user at the very end. This is unclean because
 *	we open the socket then return an error.
 *
 *	1003.1g adds the ability to recvmsg() to query connection pending
 *	status to recvmsg. We need to add that support in a way thats
 *	clean when we restucture accept also.
 */

asmlinkage long sys_accept(int fd, struct sockaddr *upeer_sockaddr, int *upeer_addrlen)
{
	struct socket *sock, *newsock;
	int err, len;
	char address[MAX_SOCK_ADDR];

	sock = sockfd_lookup(fd, &err);
	if (!sock)
		goto out;

	err = -EMFILE;
	if (!(newsock = sock_alloc())) 
		goto out_put;

	newsock->type = sock->type;
	newsock->ops = sock->ops;

	err = sock->ops->accept(sock, newsock, sock->file->f_flags);
	if (err < 0)
		goto out_release;

	if (upeer_sockaddr) {
		if(newsock->ops->getname(newsock, (struct sockaddr *)address, &len, 2)<0) {
			err = -ECONNABORTED;
			goto out_release;
		}
		err = move_addr_to_user(address, len, upeer_sockaddr, upeer_addrlen);
		if (err < 0)
			goto out_release;
	}

	/* File flags are not inherited via accept() unlike another OSes. */

	if ((err = sock_map_fd(newsock)) < 0)
		goto out_release;

out_put:
	sockfd_put(sock);
out:
	return err;

out_release:
	sock_release(newsock);
	goto out_put;
}


/*
 *	Attempt to connect to a socket with the server address.  The address
 *	is in user space so we verify it is OK and move it to kernel space.
 *
 *	For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
 *	break bindings
 *
 *	NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
 *	other SEQPACKET protocols that take time to connect() as it doesn't
 *	include the -EINPROGRESS status for such sockets.
 */

asmlinkage long sys_connect(int fd, struct sockaddr *uservaddr, int addrlen)
{
	struct socket *sock;
	char address[MAX_SOCK_ADDR];
	int err;

	sock = sockfd_lookup(fd, &err);
	if (!sock)
		goto out;
	err = move_addr_to_kernel(uservaddr, addrlen, address);
	if (err < 0)
		goto out_put;
	err = sock->ops->connect(sock, (struct sockaddr *) address, addrlen,
				 sock->file->f_flags);
out_put:
	sockfd_put(sock);
out:
	return err;
}

/*
 *	Get the local address ('name') of a socket object. Move the obtained
 *	name to user space.
 */

asmlinkage long sys_getsockname(int fd, struct sockaddr *usockaddr, int *usockaddr_len)
{
	struct socket *sock;
	char address[MAX_SOCK_ADDR];
	int len, err;
	
	sock = sockfd_lookup(fd, &err);
	if (!sock)
		goto out;
	err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 0);
	if (err)
		goto out_put;
	err = move_addr_to_user(address, len, usockaddr, usockaddr_len);

out_put:
	sockfd_put(sock);
out:
	return err;
}

/*
 *	Get the remote address ('name') of a socket object. Move the obtained
 *	name to user space.
 */

asmlinkage long sys_getpeername(int fd, struct sockaddr *usockaddr, int *usockaddr_len)
{
	struct socket *sock;
	char address[MAX_SOCK_ADDR];
	int len, err;

	if ((sock = sockfd_lookup(fd, &err))!=NULL)
	{
		err = sock->ops->getname(sock, (struct sockaddr *)address, &len, 1);
		if (!err)
			err=move_addr_to_user(address,len, usockaddr, usockaddr_len);
		sockfd_put(sock);
	}
	return err;
}