dn_dev.c

Linux Kernel 2.6.9 for OMAP1710

	struct sockaddr_dn *sdn = (struct sockaddr_dn *)&ifr->ifr_addr;
	struct dn_dev *dn_db;
	struct net_device *dev;
	struct dn_ifaddr *ifa = NULL, **ifap = NULL;
	int ret = 0;

	if (copy_from_user(ifr, arg, DN_IFREQ_SIZE))
		return -EFAULT;
	ifr->ifr_name[IFNAMSIZ-1] = 0;

#ifdef CONFIG_KMOD
	dev_load(ifr->ifr_name);
#endif

	switch(cmd) {
		case SIOCGIFADDR:
			break;
		case SIOCSIFADDR:
			if (!capable(CAP_NET_ADMIN))
				return -EACCES;
			if (sdn->sdn_family != AF_DECnet)
				return -EINVAL;
			break;
		default:
			return -EINVAL;
	}

	rtnl_lock();

	if ((dev = __dev_get_by_name(ifr->ifr_name)) == NULL) {
		ret = -ENODEV;
		goto done;
	}

	if ((dn_db = dev->dn_ptr) != NULL) {
		for (ifap = &dn_db->ifa_list; (ifa=*ifap) != NULL; ifap = &ifa->ifa_next)
			if (strcmp(ifr->ifr_name, ifa->ifa_label) == 0)
				break;
	}

	if (ifa == NULL && cmd != SIOCSIFADDR) {
		ret = -EADDRNOTAVAIL;
		goto done;
	}

	switch(cmd) {
		case SIOCGIFADDR:
			*((dn_address *)sdn->sdn_nodeaddr) = ifa->ifa_local;
			goto rarok;

		case SIOCSIFADDR:
			if (!ifa) {
				if ((ifa = dn_dev_alloc_ifa()) == NULL) {
					ret = -ENOBUFS;
					break;
				}
				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
			} else {
				if (ifa->ifa_local == dn_saddr2dn(sdn))
					break;
				dn_dev_del_ifa(dn_db, ifap, 0);
			}

			ifa->ifa_local = ifa->ifa_address = dn_saddr2dn(sdn);

			ret = dn_dev_set_ifa(dev, ifa);
	}
done:
	rtnl_unlock();

	return ret;
rarok:
	if (copy_to_user(arg, ifr, DN_IFREQ_SIZE))
		ret = -EFAULT;
	goto done;
}

struct net_device *dn_dev_get_default(void)
{
	struct net_device *dev;
	read_lock(&dndev_lock);
	dev = decnet_default_device;
	if (dev) {
		if (dev->dn_ptr)
			dev_hold(dev);
		else
			dev = NULL;
	}
	read_unlock(&dndev_lock);
	return dev;
}

int dn_dev_set_default(struct net_device *dev, int force)
{
	struct net_device *old = NULL;
	int rv = -EBUSY;
	if (!dev->dn_ptr)
		return -ENODEV;
	write_lock(&dndev_lock);
	if (force || decnet_default_device == NULL) {
		old = decnet_default_device;
		decnet_default_device = dev;
		rv = 0;
	}
	write_unlock(&dndev_lock);
	if (old)
		dev_put(dev);
	return rv;
}

static void dn_dev_check_default(struct net_device *dev)
{
	write_lock(&dndev_lock);
	if (dev == decnet_default_device) {
		decnet_default_device = NULL;
	} else {
		dev = NULL;
	}
	write_unlock(&dndev_lock);
	if (dev)
		dev_put(dev);
}

static struct dn_dev *dn_dev_by_index(int ifindex)
{
	struct net_device *dev;
	struct dn_dev *dn_dev = NULL;
	dev = dev_get_by_index(ifindex);
	if (dev) {
		dn_dev = dev->dn_ptr;
		dev_put(dev);
	}

	return dn_dev;
}

static int dn_dev_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct dn_dev *dn_db;
	struct ifaddrmsg *ifm = NLMSG_DATA(nlh);
	struct dn_ifaddr *ifa, **ifap;

	if ((dn_db = dn_dev_by_index(ifm->ifa_index)) == NULL)
		return -EADDRNOTAVAIL;

	for(ifap = &dn_db->ifa_list; (ifa=*ifap) != NULL; ifap = &ifa->ifa_next) {
		void *tmp = rta[IFA_LOCAL-1];
		if ((tmp && memcmp(RTA_DATA(tmp), &ifa->ifa_local, 2)) ||
				(rta[IFA_LABEL-1] && strcmp(RTA_DATA(rta[IFA_LABEL-1]), ifa->ifa_label)))
			continue;

		dn_dev_del_ifa(dn_db, ifap, 1);
		return 0;
	}

	return -EADDRNOTAVAIL;
}

static int dn_dev_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct rtattr **rta = arg;
	struct net_device *dev;
	struct dn_dev *dn_db;
	struct ifaddrmsg *ifm = NLMSG_DATA(nlh);
	struct dn_ifaddr *ifa;
	int rv;

	if (rta[IFA_LOCAL-1] == NULL)
		return -EINVAL;

	if ((dev = __dev_get_by_index(ifm->ifa_index)) == NULL)
		return -ENODEV;

	if ((dn_db = dev->dn_ptr) == NULL) {
		int err;
		dn_db = dn_dev_create(dev, &err);
		if (!dn_db)
			return err;
	}
	
	if ((ifa = dn_dev_alloc_ifa()) == NULL)
		return -ENOBUFS;

	if (!rta[IFA_ADDRESS - 1])
		rta[IFA_ADDRESS - 1] = rta[IFA_LOCAL - 1];
	memcpy(&ifa->ifa_local, RTA_DATA(rta[IFA_LOCAL-1]), 2);
	memcpy(&ifa->ifa_address, RTA_DATA(rta[IFA_ADDRESS-1]), 2);
	ifa->ifa_flags = ifm->ifa_flags;
	ifa->ifa_scope = ifm->ifa_scope;
	ifa->ifa_dev = dn_db;
	if (rta[IFA_LABEL-1])
		memcpy(ifa->ifa_label, RTA_DATA(rta[IFA_LABEL-1]), IFNAMSIZ);
	else
		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);

	rv = dn_dev_insert_ifa(dn_db, ifa);
	if (rv)
		dn_dev_free_ifa(ifa);
	return rv;
}

static int dn_dev_fill_ifaddr(struct sk_buff *skb, struct dn_ifaddr *ifa,
				u32 pid, u32 seq, int event)
{
	struct ifaddrmsg *ifm;
	struct nlmsghdr *nlh;
	unsigned char *b = skb->tail;

	nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*ifm));
	ifm = NLMSG_DATA(nlh);

	ifm->ifa_family = AF_DECnet;
	ifm->ifa_prefixlen = 16;
	ifm->ifa_flags = ifa->ifa_flags | IFA_F_PERMANENT;
	ifm->ifa_scope = ifa->ifa_scope;
	ifm->ifa_index = ifa->ifa_dev->dev->ifindex;
	if (ifa->ifa_address)
		RTA_PUT(skb, IFA_ADDRESS, 2, &ifa->ifa_address);
	if (ifa->ifa_local)
		RTA_PUT(skb, IFA_LOCAL, 2, &ifa->ifa_local);
	if (ifa->ifa_label[0])
		RTA_PUT(skb, IFA_LABEL, IFNAMSIZ, &ifa->ifa_label);
	nlh->nlmsg_len = skb->tail - b;
	return skb->len;

nlmsg_failure:
rtattr_failure:
        skb_trim(skb, b - skb->data);
        return -1;
}

static void rtmsg_ifa(int event, struct dn_ifaddr *ifa)
{
	struct sk_buff *skb;
	int size = NLMSG_SPACE(sizeof(struct ifaddrmsg)+128);

	skb = alloc_skb(size, GFP_KERNEL);
	if (!skb) {
		netlink_set_err(rtnl, 0, RTMGRP_DECnet_IFADDR, ENOBUFS);
		return;
	}
	if (dn_dev_fill_ifaddr(skb, ifa, 0, 0, event) < 0) {
		kfree_skb(skb);
		netlink_set_err(rtnl, 0, RTMGRP_DECnet_IFADDR, EINVAL);
		return;
	}
	NETLINK_CB(skb).dst_groups = RTMGRP_DECnet_IFADDR;
	netlink_broadcast(rtnl, skb, 0, RTMGRP_DECnet_IFADDR, GFP_KERNEL);
}

static int dn_dev_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx, dn_idx;
	int s_idx, s_dn_idx;
	struct net_device *dev;
	struct dn_dev *dn_db;
	struct dn_ifaddr *ifa;

	s_idx = cb->args[0];
	s_dn_idx = dn_idx = cb->args[1];
	read_lock(&dev_base_lock);
	for(dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
		if (idx < s_idx)
			continue;
		if (idx > s_idx)
			s_dn_idx = 0;
		if ((dn_db = dev->dn_ptr) == NULL)
			continue;

		for(ifa = dn_db->ifa_list, dn_idx = 0; ifa; ifa = ifa->ifa_next, dn_idx++) {
			if (dn_idx < s_dn_idx)
				continue;

			if (dn_dev_fill_ifaddr(skb, ifa,
					       NETLINK_CB(cb->skb).pid,
					       cb->nlh->nlmsg_seq,
					       RTM_NEWADDR) <= 0)
				goto done;
		}
	}
done:
	read_unlock(&dev_base_lock);
	cb->args[0] = idx;
	cb->args[1] = dn_idx;

	return skb->len;
}

static int dn_dev_get_first(struct net_device *dev, dn_address *addr)
{
	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;
	struct dn_ifaddr *ifa;
	int rv = -ENODEV;
	if (dn_db == NULL)
		goto out;
	ifa = dn_db->ifa_list;
	if (ifa != NULL) {
		*addr = ifa->ifa_local;
		rv = 0;
	}
out:
	return rv;
}

/* 
 * Find a default address to bind to.
 *
 * This is one of those areas where the initial VMS concepts don't really
 * map onto the Linux concepts, and since we introduced multiple addresses
 * per interface we have to cope with slightly odd ways of finding out what
 * "our address" really is. Mostly it's not a problem; for this we just guess
 * a sensible default. Eventually the routing code will take care of all the
 * nasties for us I hope.
 */
int dn_dev_bind_default(dn_address *addr)
{
	struct net_device *dev;
	int rv;
	dev = dn_dev_get_default();
last_chance:
	if (dev) {
		read_lock(&dev_base_lock);
		rv = dn_dev_get_first(dev, addr);
		read_unlock(&dev_base_lock);
		dev_put(dev);
		if (rv == 0 || dev == &loopback_dev)
			return rv;
	}
	dev = &loopback_dev;
	dev_hold(dev);
	goto last_chance;
}

static void dn_send_endnode_hello(struct net_device *dev, struct dn_ifaddr *ifa)
{
        struct endnode_hello_message *msg;
        struct sk_buff *skb = NULL;
        unsigned short int *pktlen;
	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;

        if ((skb = dn_alloc_skb(NULL, sizeof(*msg), GFP_ATOMIC)) == NULL)
		return;

        skb->dev = dev;

        msg = (struct endnode_hello_message *)skb_put(skb,sizeof(*msg));

        msg->msgflg  = 0x0D;
        memcpy(msg->tiver, dn_eco_version, 3);
	dn_dn2eth(msg->id, ifa->ifa_local);
        msg->iinfo   = DN_RT_INFO_ENDN;
        msg->blksize = dn_htons(mtu2blksize(dev));
        msg->area    = 0x00;
        memset(msg->seed, 0, 8);
        memcpy(msg->neighbor, dn_hiord, ETH_ALEN);

	if (dn_db->router) {
		struct dn_neigh *dn = (struct dn_neigh *)dn_db->router;
		dn_dn2eth(msg->neighbor, dn->addr);
	}

        msg->timer   = dn_htons((unsigned short)dn_db->parms.t3);
        msg->mpd     = 0x00;
        msg->datalen = 0x02;
        memset(msg->data, 0xAA, 2);
        
        pktlen = (unsigned short *)skb_push(skb,2);
        *pktlen = dn_htons(skb->len - 2);

	skb->nh.raw = skb->data;

	dn_rt_finish_output(skb, dn_rt_all_rt_mcast, msg->id);
}


#define DRDELAY (5 * HZ)

static int dn_am_i_a_router(struct dn_neigh *dn, struct dn_dev *dn_db, struct dn_ifaddr *ifa)
{
	/* First check time since device went up */
	if ((jiffies - dn_db->uptime) < DRDELAY)
		return 0;

	/* If there is no router, then yes... */
	if (!dn_db->router)
		return 1;

	/* otherwise only if we have a higher priority or.. */
	if (dn->priority < dn_db->parms.priority)
		return 1;

	/* if we have equal priority and a higher node number */
	if (dn->priority != dn_db->parms.priority)
		return 0;

	if (dn_ntohs(dn->addr) < dn_ntohs(ifa->ifa_local))
		return 1;

	return 0;
}

static void dn_send_router_hello(struct net_device *dev, struct dn_ifaddr *ifa)
{
	int n;
	struct dn_dev *dn_db = dev->dn_ptr;
	struct dn_neigh *dn = (struct dn_neigh *)dn_db->router;
	struct sk_buff *skb;
	size_t size;
	unsigned char *ptr;
	unsigned char *i1, *i2;
	unsigned short *pktlen;
	char *src;

	if (mtu2blksize(dev) < (26 + 7))
		return;

	n = mtu2blksize(dev) - 26;
	n /= 7;

	if (n > 32)
		n = 32;

	size = 2 + 26 + 7 * n;

	if ((skb = dn_alloc_skb(NULL, size, GFP_ATOMIC)) == NULL)
		return;

	skb->dev = dev;
	ptr = skb_put(skb, size);

	*ptr++ = DN_RT_PKT_CNTL | DN_RT_PKT_ERTH;
	*ptr++ = 2; /* ECO */
	*ptr++ = 0;
	*ptr++ = 0;
	dn_dn2eth(ptr, ifa->ifa_local);
	src = ptr;
	ptr += ETH_ALEN;
	*ptr++ = dn_db->parms.forwarding == 1 ? 
			DN_RT_INFO_L1RT : DN_RT_INFO_L2RT;
	*((unsigned short *)ptr) = dn_htons(mtu2blksize(dev));
	ptr += 2;
	*ptr++ = dn_db->parms.priority; /* Priority */ 
	*ptr++ = 0; /* Area: Reserved */
	*((unsigned short *)ptr) = dn_htons((unsigned short)dn_db->parms.t3);
	ptr += 2;
	*ptr++ = 0; /* MPD: Reserved */
	i1 = ptr++;
	memset(ptr, 0, 7); /* Name: Reserved */
	ptr += 7;
	i2 = ptr++;

	n = dn_neigh_elist(dev, ptr, n);

	*i2 = 7 * n;
	*i1 = 8 + *i2;

	skb_trim(skb, (27 + *i2));

	pktlen = (unsigned short *)skb_push(skb, 2);
	*pktlen = dn_htons(skb->len - 2);

	skb->nh.raw = skb->data;

	if (dn_am_i_a_router(dn, dn_db, ifa)) {
		struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
		if (skb2) {
			dn_rt_finish_output(skb2, dn_rt_all_end_mcast, src);
		}
	}

	dn_rt_finish_output(skb, dn_rt_all_rt_mcast, src);
}

static void dn_send_brd_hello(struct net_device *dev, struct dn_ifaddr *ifa)
{
	struct dn_dev *dn_db = (struct dn_dev *)dev->dn_ptr;

	if (dn_db->parms.forwarding == 0)
		dn_send_endnode_hello(dev, ifa);
	else
		dn_send_router_hello(dev, ifa);
}

static void dn_send_ptp_hello(struct net_device *dev, struct dn_ifaddr *ifa)
{
	int tdlen = 16;
	int size = dev->hard_header_len + 2 + 4 + tdlen;
	struct sk_buff *skb = dn_alloc_skb(NULL, size, GFP_ATOMIC);
	int i;
	unsigned char *ptr;
	char src[ETH_ALEN];

	if (skb == NULL)
		return ;

	skb->dev = dev;
	skb_push(skb, dev->hard_header_len);
	ptr = skb_put(skb, 2 + 4 + tdlen);

	*ptr++ = DN_RT_PKT_HELO;
	*((dn_address *)ptr) = ifa->ifa_local;
	ptr += 2;
	*ptr++ = tdlen;

	for(i = 0; i < tdlen; i++)
		*ptr++ = 0252;

	dn_dn2eth(src, ifa->ifa_local);
	dn_rt_finish_output(skb, dn_rt_all_rt_mcast, src);
}

static int dn_eth_up(struct net_device *dev)
{
	struct dn_dev *dn_db = dev->dn_ptr;