socket.c

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/*
 *	Send a datagram to a given address. We move the address into kernel
 *	space and check the user space data area is readable before invoking
 *	the protocol.
 */

asmlinkage long sys_sendto(int fd, void * buff, size_t len, unsigned flags,
			   struct sockaddr *addr, int addr_len)
{
	struct socket *sock;
	char address[MAX_SOCK_ADDR];
	int err;
	struct msghdr msg;
	struct iovec iov;
	
	sock = sockfd_lookup(fd, &err);
	if (!sock)
		goto out;
	iov.iov_base=buff;
	iov.iov_len=len;
	msg.msg_name=NULL;
	msg.msg_iov=&iov;
	msg.msg_iovlen=1;
	msg.msg_control=NULL;
	msg.msg_controllen=0;
	msg.msg_namelen=0;
	if(addr)
	{
		err = move_addr_to_kernel(addr, addr_len, address);
		if (err < 0)
			goto out_put;
		msg.msg_name=address;
		msg.msg_namelen=addr_len;
	}
	if (sock->file->f_flags & O_NONBLOCK)
		flags |= MSG_DONTWAIT;
	msg.msg_flags = flags;
	err = sock_sendmsg(sock, &msg, len);

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

/*
 *	Send a datagram down a socket. 
 */

asmlinkage long sys_send(int fd, void * buff, size_t len, unsigned flags)
{
	return sys_sendto(fd, buff, len, flags, NULL, 0);
}

/*
 *	Receive a frame from the socket and optionally record the address of the 
 *	sender. We verify the buffers are writable and if needed move the
 *	sender address from kernel to user space.
 */

asmlinkage long sys_recvfrom(int fd, void * ubuf, size_t size, unsigned flags,
			     struct sockaddr *addr, int *addr_len)
{
	struct socket *sock;
	struct iovec iov;
	struct msghdr msg;
	char address[MAX_SOCK_ADDR];
	int err,err2;

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

	msg.msg_control=NULL;
	msg.msg_controllen=0;
	msg.msg_iovlen=1;
	msg.msg_iov=&iov;
	iov.iov_len=size;
	iov.iov_base=ubuf;
	msg.msg_name=address;
	msg.msg_namelen=MAX_SOCK_ADDR;
	if (sock->file->f_flags & O_NONBLOCK)
		flags |= MSG_DONTWAIT;
	err=sock_recvmsg(sock, &msg, size, flags);

	if(err >= 0 && addr != NULL && msg.msg_namelen)
	{
		err2=move_addr_to_user(address, msg.msg_namelen, addr, addr_len);
		if(err2<0)
			err=err2;
	}
	sockfd_put(sock);			
out:
	return err;
}

/*
 *	Receive a datagram from a socket. 
 */

asmlinkage long sys_recv(int fd, void * ubuf, size_t size, unsigned flags)
{
	return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
}

/*
 *	Set a socket option. Because we don't know the option lengths we have
 *	to pass the user mode parameter for the protocols to sort out.
 */

asmlinkage long sys_setsockopt(int fd, int level, int optname, char *optval, int optlen)
{
	int err;
	struct socket *sock;

	if (optlen < 0)
		return -EINVAL;
			
	if ((sock = sockfd_lookup(fd, &err))!=NULL)
	{
		if (level == SOL_SOCKET)
			err=sock_setsockopt(sock,level,optname,optval,optlen);
		else
			err=sock->ops->setsockopt(sock, level, optname, optval, optlen);
		sockfd_put(sock);
	}
	return err;
}

/*
 *	Get a socket option. Because we don't know the option lengths we have
 *	to pass a user mode parameter for the protocols to sort out.
 */

asmlinkage long sys_getsockopt(int fd, int level, int optname, char *optval, int *optlen)
{
	int err;
	struct socket *sock;

	if ((sock = sockfd_lookup(fd, &err))!=NULL)
	{
		if (level == SOL_SOCKET)
			err=sock_getsockopt(sock,level,optname,optval,optlen);
		else
			err=sock->ops->getsockopt(sock, level, optname, optval, optlen);
		sockfd_put(sock);
	}
	return err;
}


/*
 *	Shutdown a socket.
 */

asmlinkage long sys_shutdown(int fd, int how)
{
	int err;
	struct socket *sock;

	if ((sock = sockfd_lookup(fd, &err))!=NULL)
	{
		err=sock->ops->shutdown(sock, how);
		sockfd_put(sock);
	}
	return err;
}

/*
 *	BSD sendmsg interface
 */

asmlinkage long sys_sendmsg(int fd, struct msghdr *msg, unsigned flags)
{
	struct socket *sock;
	char address[MAX_SOCK_ADDR];
	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
	unsigned char ctl[sizeof(struct cmsghdr) + 20];	/* 20 is size of ipv6_pktinfo */
	unsigned char *ctl_buf = ctl;
	struct msghdr msg_sys;
	int err, ctl_len, iov_size, total_len;
	
	err = -EFAULT;
	if (copy_from_user(&msg_sys,msg,sizeof(struct msghdr)))
		goto out; 

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

	/* do not move before msg_sys is valid */
	err = -EINVAL;
	if (msg_sys.msg_iovlen > UIO_MAXIOV)
		goto out_put;

	/* Check whether to allocate the iovec area*/
	err = -ENOMEM;
	iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
	if (msg_sys.msg_iovlen > UIO_FASTIOV) {
		iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
		if (!iov)
			goto out_put;
	}

	/* This will also move the address data into kernel space */
	err = verify_iovec(&msg_sys, iov, address, VERIFY_READ);
	if (err < 0) 
		goto out_freeiov;
	total_len = err;

	err = -ENOBUFS;

	if (msg_sys.msg_controllen > INT_MAX)
		goto out_freeiov;
	ctl_len = msg_sys.msg_controllen; 
	if (ctl_len) 
	{
		if (ctl_len > sizeof(ctl))
		{
			ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
			if (ctl_buf == NULL) 
				goto out_freeiov;
		}
		err = -EFAULT;
		if (copy_from_user(ctl_buf, msg_sys.msg_control, ctl_len))
			goto out_freectl;
		msg_sys.msg_control = ctl_buf;
	}
	msg_sys.msg_flags = flags;

	if (sock->file->f_flags & O_NONBLOCK)
		msg_sys.msg_flags |= MSG_DONTWAIT;
	err = sock_sendmsg(sock, &msg_sys, total_len);

out_freectl:
	if (ctl_buf != ctl)    
		sock_kfree_s(sock->sk, ctl_buf, ctl_len);
out_freeiov:
	if (iov != iovstack)
		sock_kfree_s(sock->sk, iov, iov_size);
out_put:
	sockfd_put(sock);
out:       
	return err;
}

/*
 *	BSD recvmsg interface
 */

asmlinkage long sys_recvmsg(int fd, struct msghdr *msg, unsigned int flags)
{
	struct socket *sock;
	struct iovec iovstack[UIO_FASTIOV];
	struct iovec *iov=iovstack;
	struct msghdr msg_sys;
	unsigned long cmsg_ptr;
	int err, iov_size, total_len, len;

	/* kernel mode address */
	char addr[MAX_SOCK_ADDR];

	/* user mode address pointers */
	struct sockaddr *uaddr;
	int *uaddr_len;
	
	err=-EFAULT;
	if (copy_from_user(&msg_sys,msg,sizeof(struct msghdr)))
		goto out;

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

	err = -EINVAL;
	if (msg_sys.msg_iovlen > UIO_MAXIOV)
		goto out_put;
	
	/* Check whether to allocate the iovec area*/
	err = -ENOMEM;
	iov_size = msg_sys.msg_iovlen * sizeof(struct iovec);
	if (msg_sys.msg_iovlen > UIO_FASTIOV) {
		iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL);
		if (!iov)
			goto out_put;
	}

	/*
	 *	Save the user-mode address (verify_iovec will change the
	 *	kernel msghdr to use the kernel address space)
	 */
	 
	uaddr = msg_sys.msg_name;
	uaddr_len = &msg->msg_namelen;
	err = verify_iovec(&msg_sys, iov, addr, VERIFY_WRITE);
	if (err < 0)
		goto out_freeiov;
	total_len=err;

	cmsg_ptr = (unsigned long)msg_sys.msg_control;
	msg_sys.msg_flags = 0;
	
	if (sock->file->f_flags & O_NONBLOCK)
		flags |= MSG_DONTWAIT;
	err = sock_recvmsg(sock, &msg_sys, total_len, flags);
	if (err < 0)
		goto out_freeiov;
	len = err;

	if (uaddr != NULL && msg_sys.msg_namelen) {
		err = move_addr_to_user(addr, msg_sys.msg_namelen, uaddr, uaddr_len);
		if (err < 0)
			goto out_freeiov;
	}
	err = __put_user(msg_sys.msg_flags, &msg->msg_flags);
	if (err)
		goto out_freeiov;
	err = __put_user((unsigned long)msg_sys.msg_control-cmsg_ptr, 
							 &msg->msg_controllen);
	if (err)
		goto out_freeiov;
	err = len;

out_freeiov:
	if (iov != iovstack)
		sock_kfree_s(sock->sk, iov, iov_size);
out_put:
	sockfd_put(sock);
out:
	return err;
}


/*
 *	Perform a file control on a socket file descriptor.
 *
 *	Doesn't acquire a fd lock, because no network fcntl
 *	function sleeps currently.
 */

int sock_fcntl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	struct socket *sock;

	sock = socki_lookup (filp->f_dentry->d_inode);
	if (sock && sock->ops)
		return sock_no_fcntl(sock, cmd, arg);
	return(-EINVAL);
}

/* Argument list sizes for sys_socketcall */
#define AL(x) ((x) * sizeof(unsigned long))
static unsigned char nargs[18]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3),
				AL(3),AL(3),AL(4),AL(4),AL(4),AL(6),
				AL(6),AL(2),AL(5),AL(5),AL(3),AL(3)};
#undef AL

/*
 *	System call vectors. 
 *
 *	Argument checking cleaned up. Saved 20% in size.
 *  This function doesn't need to set the kernel lock because
 *  it is set by the callees. 
 */

asmlinkage long sys_socketcall(int call, unsigned long *args)
{
	unsigned long a[6];
	unsigned long a0,a1;
	int err;

	if(call<1||call>SYS_RECVMSG)
		return -EINVAL;

	/* copy_from_user should be SMP safe. */
	if (copy_from_user(a, args, nargs[call]))
		return -EFAULT;
		
	a0=a[0];
	a1=a[1];
	
	switch(call) 
	{
		case SYS_SOCKET:
			err = sys_socket(a0,a1,a[2]);
			break;
		case SYS_BIND:
			err = sys_bind(a0,(struct sockaddr *)a1, a[2]);
			break;
		case SYS_CONNECT:
			err = sys_connect(a0, (struct sockaddr *)a1, a[2]);
			break;
		case SYS_LISTEN:
			err = sys_listen(a0,a1);
			break;
		case SYS_ACCEPT:
			err = sys_accept(a0,(struct sockaddr *)a1, (int *)a[2]);
			break;
		case SYS_GETSOCKNAME:
			err = sys_getsockname(a0,(struct sockaddr *)a1, (int *)a[2]);
			break;
		case SYS_GETPEERNAME:
			err = sys_getpeername(a0, (struct sockaddr *)a1, (int *)a[2]);
			break;
		case SYS_SOCKETPAIR:
			err = sys_socketpair(a0,a1, a[2], (int *)a[3]);
			break;
		case SYS_SEND:
			err = sys_send(a0, (void *)a1, a[2], a[3]);
			break;
		case SYS_SENDTO:
			err = sys_sendto(a0,(void *)a1, a[2], a[3],
					 (struct sockaddr *)a[4], a[5]);
			break;
		case SYS_RECV:
			err = sys_recv(a0, (void *)a1, a[2], a[3]);
			break;
		case SYS_RECVFROM:
			err = sys_recvfrom(a0, (void *)a1, a[2], a[3],
					   (struct sockaddr *)a[4], (int *)a[5]);
			break;
		case SYS_SHUTDOWN:
			err = sys_shutdown(a0,a1);
			break;
		case SYS_SETSOCKOPT:
			err = sys_setsockopt(a0, a1, a[2], (char *)a[3], a[4]);
			break;
		case SYS_GETSOCKOPT:
			err = sys_getsockopt(a0, a1, a[2], (char *)a[3], (int *)a[4]);
			break;
		case SYS_SENDMSG:
			err = sys_sendmsg(a0, (struct msghdr *) a1, a[2]);
			break;
		case SYS_RECVMSG:
			err = sys_recvmsg(a0, (struct msghdr *) a1, a[2]);
			break;
		default:
			err = -EINVAL;
			break;
	}
	return err;
}

/*
 *	This function is called by a protocol handler that wants to
 *	advertise its address family, and have it linked into the
 *	SOCKET module.
 */

int sock_register(struct net_proto_family *ops)
{
	int err;

	if (ops->family >= NPROTO) {
		printk(KERN_CRIT "protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
		return -ENOBUFS;
	}
	net_family_write_lock();
	err = -EEXIST;
	if (net_families[ops->family] == NULL) {
		net_families[ops->family]=ops;
		err = 0;
	}
	net_family_write_unlock();
	return err;
}

/*
 *	This function is called by a protocol handler that wants to
 *	remove its address family, and have it unlinked from the
 *	SOCKET module.
 */

int sock_unregister(int family)
{
	if (family < 0 || family >= NPROTO)
		return -1;

	net_family_write_lock();
	net_families[family]=NULL;
	net_family_write_unlock();
	return 0;
}


extern void sk_init(void);

#ifdef CONFIG_WAN_ROUTER
extern void wanrouter_init(void);
#endif

#ifdef CONFIG_BLUEZ
extern void bluez_init(void);
#endif

void __init sock_init(void)
{
	int i;

	printk(KERN_INFO "Linux NET4.0 for Linux 2.4\n");
	printk(KERN_INFO "Based upon Swansea University Computer Society NET3.039\n");

	/*
	 *	Initialize all address (protocol) families. 
	 */
	 
	for (i = 0; i < NPROTO; i++) 
		net_families[i] = NULL;

	/*
	 *	Initialize sock SLAB cache.
	 */
	 
	sk_init();

#ifdef SLAB_SKB
	/*
	 *	Initialize skbuff SLAB cache 
	 */
	skb_init();
#endif

	/*
	 *	Wan router layer. 
	 */

#ifdef CONFIG_WAN_ROUTER	 
	wanrouter_init();
#endif

	/*
	 *	Initialize the protocols module. 
	 */

	register_filesystem(&sock_fs_type);
	sock_mnt = kern_mount(&sock_fs_type);
	/* The real protocol initialization is performed when
	 *  do_initcalls is run.  
	 */


	/*
	 * The netlink device handler may be needed early.
	 */

#ifdef CONFIG_NET
	rtnetlink_init();
#endif
#ifdef CONFIG_NETLINK_DEV
	init_netlink();
#endif
#ifdef CONFIG_NETFILTER
	netfilter_init();
#endif

#ifdef CONFIG_BLUEZ
	bluez_init();
#endif
}

int socket_get_info(char *buffer, char **start, off_t offset, int length)
{
	int len, cpu;
	int counter = 0;

	for (cpu=0; cpu<smp_num_cpus; cpu++)
		counter += sockets_in_use[cpu_logical_map(cpu)].counter;

	/* It can be negative, by the way. 8) */
	if (counter < 0)
		counter = 0;

	len = sprintf(buffer, "sockets: used %d\n", counter);
	if (offset >= len)
	{
		*start = buffer;
		return 0;
	}
	*start = buffer + offset;
	len -= offset;
	if (len > length)
		len = length;
	if (len < 0)
		len = 0;
	return len;
}