af_ax25.c

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

		return -ENODEV;

	if (ax25_ctl.digi_count > AX25_MAX_DIGIS)
		return -EINVAL;

	digi.ndigi = ax25_ctl.digi_count;
	for (k = 0; k < digi.ndigi; k++)
		digi.calls[k] = ax25_ctl.digi_addr[k];

	if ((ax25 = ax25_find_cb(&ax25_ctl.source_addr, &ax25_ctl.dest_addr, &digi, ax25_dev->dev)) == NULL)
		return -ENOTCONN;

	switch (ax25_ctl.cmd) {
		case AX25_KILL:
			ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
#ifdef CONFIG_AX25_DAMA_SLAVE
			if (ax25_dev->dama.slave && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)
				ax25_dama_off(ax25);
#endif
			ax25_disconnect(ax25, ENETRESET);
			break;

	  	case AX25_WINDOW:
	  		if (ax25->modulus == AX25_MODULUS) {
	  			if (ax25_ctl.arg < 1 || ax25_ctl.arg > 7)
	  				return -EINVAL;
	  		} else {
	  			if (ax25_ctl.arg < 1 || ax25_ctl.arg > 63)
	  				return -EINVAL;
	  		}
	  		ax25->window = ax25_ctl.arg;
	  		break;

	  	case AX25_T1:
  			if (ax25_ctl.arg < 1)
  				return -EINVAL;
  			ax25->rtt = (ax25_ctl.arg * HZ) / 2;
  			ax25->t1  = ax25_ctl.arg * HZ;
  			break;

	  	case AX25_T2:
	  		if (ax25_ctl.arg < 1)
	  			return -EINVAL;
	  		ax25->t2 = ax25_ctl.arg * HZ;
	  		break;

	  	case AX25_N2:
	  		if (ax25_ctl.arg < 1 || ax25_ctl.arg > 31)
	  			return -EINVAL;
	  		ax25->n2count = 0;
	  		ax25->n2 = ax25_ctl.arg;
	  		break;

	  	case AX25_T3:
	  		if (ax25_ctl.arg < 0)
	  			return -EINVAL;
	  		ax25->t3 = ax25_ctl.arg * HZ;
	  		break;

	  	case AX25_IDLE:
	  		if (ax25_ctl.arg < 0)
	  			return -EINVAL;
	  		ax25->idle = ax25_ctl.arg * 60 * HZ;
	  		break;

	  	case AX25_PACLEN:
	  		if (ax25_ctl.arg < 16 || ax25_ctl.arg > 65535)
	  			return -EINVAL;
	  		ax25->paclen = ax25_ctl.arg;
	  		break;

	  	default:
	  		return -EINVAL;
	  }

	  return 0;
}

/*
 *	Fill in a created AX.25 created control block with the default
 *	values for a particular device.
 */
void ax25_fillin_cb(ax25_cb *ax25, ax25_dev *ax25_dev)
{
	ax25->ax25_dev = ax25_dev;

	if (ax25->ax25_dev != NULL) {
		ax25->rtt     = ax25_dev->values[AX25_VALUES_T1] / 2;
		ax25->t1      = ax25_dev->values[AX25_VALUES_T1];
		ax25->t2      = ax25_dev->values[AX25_VALUES_T2];
		ax25->t3      = ax25_dev->values[AX25_VALUES_T3];
		ax25->n2      = ax25_dev->values[AX25_VALUES_N2];
		ax25->paclen  = ax25_dev->values[AX25_VALUES_PACLEN];
		ax25->idle    = ax25_dev->values[AX25_VALUES_IDLE];
		ax25->backoff = ax25_dev->values[AX25_VALUES_BACKOFF];

		if (ax25_dev->values[AX25_VALUES_AXDEFMODE]) {
			ax25->modulus = AX25_EMODULUS;
			ax25->window  = ax25_dev->values[AX25_VALUES_EWINDOW];
		} else {
			ax25->modulus = AX25_MODULUS;
			ax25->window  = ax25_dev->values[AX25_VALUES_WINDOW];
		}
	} else {
		ax25->rtt     = AX25_DEF_T1 / 2;
		ax25->t1      = AX25_DEF_T1;
		ax25->t2      = AX25_DEF_T2;
		ax25->t3      = AX25_DEF_T3;
		ax25->n2      = AX25_DEF_N2;
		ax25->paclen  = AX25_DEF_PACLEN;
		ax25->idle    = AX25_DEF_IDLE;
		ax25->backoff = AX25_DEF_BACKOFF;

		if (AX25_DEF_AXDEFMODE) {
			ax25->modulus = AX25_EMODULUS;
			ax25->window  = AX25_DEF_EWINDOW;
		} else {
			ax25->modulus = AX25_MODULUS;
			ax25->window  = AX25_DEF_WINDOW;
		}
	}
}

/*
 * Create an empty AX.25 control block.
 */
ax25_cb *ax25_create_cb(void)
{
	ax25_cb *ax25;

	if ((ax25 = kmalloc(sizeof(*ax25), GFP_ATOMIC)) == NULL)
		return NULL;

	MOD_INC_USE_COUNT;

	memset(ax25, 0x00, sizeof(*ax25));

	skb_queue_head_init(&ax25->write_queue);
	skb_queue_head_init(&ax25->frag_queue);
	skb_queue_head_init(&ax25->ack_queue);
	skb_queue_head_init(&ax25->reseq_queue);

	init_timer(&ax25->timer);
	init_timer(&ax25->t1timer);
	init_timer(&ax25->t2timer);
	init_timer(&ax25->t3timer);
	init_timer(&ax25->idletimer);

	ax25_fillin_cb(ax25, NULL);

	ax25->state = AX25_STATE_0;

	return ax25;
}

/*
 *	Handling for system calls applied via the various interfaces to an
 *	AX25 socket object
 */

static int ax25_setsockopt(struct socket *sock, int level, int optname, char *optval, int optlen)
{
	struct sock *sk = sock->sk;
	struct net_device *dev;
	char devname[IFNAMSIZ];
	int opt;

	if (level != SOL_AX25)
		return -ENOPROTOOPT;

	if (optlen < sizeof(int))
		return -EINVAL;

	if (get_user(opt, (int *)optval))
		return -EFAULT;

	switch (optname) {
		case AX25_WINDOW:
			if (sk->protinfo.ax25->modulus == AX25_MODULUS) {
				if (opt < 1 || opt > 7)
					return -EINVAL;
			} else {
				if (opt < 1 || opt > 63)
					return -EINVAL;
			}
			sk->protinfo.ax25->window = opt;
			return 0;

		case AX25_T1:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.ax25->rtt = (opt * HZ) / 2;
			sk->protinfo.ax25->t1  = opt * HZ;
			return 0;

		case AX25_T2:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.ax25->t2 = opt * HZ;
			return 0;

		case AX25_N2:
			if (opt < 1 || opt > 31)
				return -EINVAL;
			sk->protinfo.ax25->n2 = opt;
			return 0;

		case AX25_T3:
			if (opt < 1)
				return -EINVAL;
			sk->protinfo.ax25->t3 = opt * HZ;
			return 0;

		case AX25_IDLE:
			if (opt < 0)
				return -EINVAL;
			sk->protinfo.ax25->idle = opt * 60 * HZ;
			return 0;

		case AX25_BACKOFF:
			if (opt < 0 || opt > 2)
				return -EINVAL;
			sk->protinfo.ax25->backoff = opt;
			return 0;

		case AX25_EXTSEQ:
			sk->protinfo.ax25->modulus = opt ? AX25_EMODULUS : AX25_MODULUS;
			return 0;

		case AX25_PIDINCL:
			sk->protinfo.ax25->pidincl = opt ? 1 : 0;
			return 0;

		case AX25_IAMDIGI:
			sk->protinfo.ax25->iamdigi = opt ? 1 : 0;
			return 0;

		case AX25_PACLEN:
			if (opt < 16 || opt > 65535)
				return -EINVAL;
			sk->protinfo.ax25->paclen = opt;
			return 0;

		case SO_BINDTODEVICE:
			if (optlen > IFNAMSIZ) optlen=IFNAMSIZ;
			if (copy_from_user(devname, optval, optlen))
				return -EFAULT;

			dev = dev_get_by_name(devname);
			if (dev == NULL) return -ENODEV;

			if (sk->type == SOCK_SEQPACKET && 
			   (sock->state != SS_UNCONNECTED || sk->state == TCP_LISTEN))
				return -EADDRNOTAVAIL;
		
			sk->protinfo.ax25->ax25_dev = ax25_dev_ax25dev(dev);
			ax25_fillin_cb(sk->protinfo.ax25, sk->protinfo.ax25->ax25_dev);
			return 0;

		default:
			return -ENOPROTOOPT;
	}
}

static int ax25_getsockopt(struct socket *sock, int level, int optname, char *optval, int *optlen)
{
	struct sock *sk = sock->sk;
	struct ax25_dev *ax25_dev;
	char devname[IFNAMSIZ];
	void *valptr;
	int val = 0;
	int maxlen, length;

	if (level != SOL_AX25)
		return -ENOPROTOOPT;

	if (get_user(maxlen, optlen))
		return -EFAULT;
		
	if (maxlen < 1)
		return -EFAULT;

	valptr = (void *) &val;
	length = min_t(unsigned int, maxlen, sizeof(int));

	switch (optname) {
		case AX25_WINDOW:
			val = sk->protinfo.ax25->window;
			break;

		case AX25_T1:
			val = sk->protinfo.ax25->t1 / HZ;
			break;

		case AX25_T2:
			val = sk->protinfo.ax25->t2 / HZ;
			break;

		case AX25_N2:
			val = sk->protinfo.ax25->n2;
			break;

		case AX25_T3:
			val = sk->protinfo.ax25->t3 / HZ;
			break;

		case AX25_IDLE:
			val = sk->protinfo.ax25->idle / (60 * HZ);
			break;

		case AX25_BACKOFF:
			val = sk->protinfo.ax25->backoff;
			break;

		case AX25_EXTSEQ:
			val = (sk->protinfo.ax25->modulus == AX25_EMODULUS);
			break;

		case AX25_PIDINCL:
			val = sk->protinfo.ax25->pidincl;
			break;

		case AX25_IAMDIGI:
			val = sk->protinfo.ax25->iamdigi;
			break;

		case AX25_PACLEN:
			val = sk->protinfo.ax25->paclen;
			break;
			
		case SO_BINDTODEVICE:
			ax25_dev = sk->protinfo.ax25->ax25_dev;

			if (ax25_dev != NULL && ax25_dev->dev != NULL) {
				strncpy(devname, ax25_dev->dev->name, IFNAMSIZ);
				length = min_t(unsigned int, strlen(ax25_dev->dev->name)+1, maxlen);
				devname[length-1] = '\0';
			} else {
				*devname = '\0';
				length = 1;
			}

			valptr = (void *) devname;
			break;

		default:
			return -ENOPROTOOPT;
	}

	if (put_user(length, optlen))
		return -EFAULT;

	return copy_to_user(optval, valptr, length) ? -EFAULT : 0;
}

static int ax25_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;

	if (sk->type == SOCK_SEQPACKET && sk->state != TCP_LISTEN) {
		sk->max_ack_backlog = backlog;
		sk->state           = TCP_LISTEN;
		return 0;
	}

	return -EOPNOTSUPP;
}

int ax25_create(struct socket *sock, int protocol)
{
	struct sock *sk;
	ax25_cb *ax25;

	switch (sock->type) {
		case SOCK_DGRAM:
			if (protocol == 0 || protocol == PF_AX25)
				protocol = AX25_P_TEXT;
			break;
		case SOCK_SEQPACKET:
			switch (protocol) {
				case 0:
				case PF_AX25:	/* For CLX */
					protocol = AX25_P_TEXT;
					break;
				case AX25_P_SEGMENT:
#ifdef CONFIG_INET
				case AX25_P_ARP:
				case AX25_P_IP:
#endif
#ifdef CONFIG_NETROM
				case AX25_P_NETROM:
#endif
#ifdef CONFIG_ROSE
				case AX25_P_ROSE:
#endif
					return -ESOCKTNOSUPPORT;
#ifdef CONFIG_NETROM_MODULE
				case AX25_P_NETROM:
					if (ax25_protocol_is_registered(AX25_P_NETROM))
						return -ESOCKTNOSUPPORT;
#endif
#ifdef CONFIG_ROSE_MODULE
				case AX25_P_ROSE:
					if (ax25_protocol_is_registered(AX25_P_ROSE))
						return -ESOCKTNOSUPPORT;
#endif
				default:
					break;
			}
			break;
		case SOCK_RAW:
			break;
		default:
			return -ESOCKTNOSUPPORT;
	}

	if ((sk = sk_alloc(PF_AX25, GFP_ATOMIC, 1)) == NULL)
		return -ENOMEM;

	if ((ax25 = ax25_create_cb()) == NULL) {
		sk_free(sk);
		return -ENOMEM;
	}

	sock_init_data(sock, sk);

	sk->destruct = ax25_free_sock;
	sock->ops    = &ax25_proto_ops;
	sk->protocol = protocol;

	ax25->sk          = sk;
	sk->protinfo.ax25 = ax25;

	return 0;
}

struct sock *ax25_make_new(struct sock *osk, struct ax25_dev *ax25_dev)
{
	struct sock *sk;
	ax25_cb *ax25;

	if ((sk = sk_alloc(PF_AX25, GFP_ATOMIC, 1)) == NULL)
		return NULL;

	if ((ax25 = ax25_create_cb()) == NULL) {
		sk_free(sk);
		return NULL;
	}

	switch (osk->type) {
		case SOCK_DGRAM:
			break;
		case SOCK_SEQPACKET:
			break;
		default:
			sk_free(sk);
			ax25_free_cb(ax25);
			return NULL;
	}

	sock_init_data(NULL, sk);

	sk->destruct = ax25_free_sock;
	sk->type     = osk->type;
	sk->socket   = osk->socket;
	sk->priority = osk->priority;
	sk->protocol = osk->protocol;
	sk->rcvbuf   = osk->rcvbuf;
	sk->sndbuf   = osk->sndbuf;
	sk->debug    = osk->debug;
	sk->state    = TCP_ESTABLISHED;