dn_dev.c

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/*
 * DECnet       An implementation of the DECnet protocol suite for the LINUX
 *              operating system.  DECnet is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              DECnet Device Layer
 *
 * Authors:     Steve Whitehouse <[e-mail]>
 *              Eduardo Marcelo Serrat <[e-mail]>
 *
 * Changes:
 *          Steve Whitehouse : Devices now see incoming frames so they
 *                             can mark on who it came from.
 *          Steve Whitehouse : Fixed bug in creating neighbours. Each neighbour
 *                             can now have a device specific setup func.
 *          Steve Whitehouse : Added /proc/sys/net/decnet/conf/<dev>/
 *          Steve Whitehouse : Fixed bug which sometimes killed timer
 *          Steve Whitehouse : Multiple ifaddr support
 *          Steve Whitehouse : SIOCGIFCONF is now a compile time option
 *          Steve Whitehouse : /proc/sys/net/decnet/conf/<sys>/forwarding
 *          Steve Whitehouse : Removed timer1 - its a user space issue now
 *         Patrick Caulfield : Fixed router hello message format
 */

#include <linux/config.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/sysctl.h>
#include <asm/uaccess.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/dn.h>
#include <net/dn_dev.h>
#include <net/dn_route.h>
#include <net/dn_neigh.h>
#include <net/dn_fib.h>

#define DN_IFREQ_SIZE (sizeof(struct ifreq) - sizeof(struct sockaddr) + sizeof(struct sockaddr_dn))

static char dn_rt_all_end_mcast[ETH_ALEN] = {0xAB,0x00,0x00,0x04,0x00,0x00};
static char dn_rt_all_rt_mcast[ETH_ALEN]  = {0xAB,0x00,0x00,0x03,0x00,0x00};
static char dn_hiord[ETH_ALEN]            = {0xAA,0x00,0x04,0x00,0x00,0x00};
static unsigned char dn_eco_version[3]    = {0x02,0x00,0x00};

extern struct neigh_table dn_neigh_table;

struct net_device *decnet_default_device = NULL;

static struct dn_dev *dn_dev_create(struct net_device *dev, int *err);
static void dn_dev_delete(struct net_device *dev);
#ifdef CONFIG_RTNETLINK
static void rtmsg_ifa(int event, struct dn_ifaddr *ifa);
#endif

static int dn_eth_up(struct net_device *);
static void dn_send_brd_hello(struct net_device *dev);
#if 0
static void dn_send_ptp_hello(struct net_device *dev);
#endif

static struct dn_dev_parms dn_dev_list[] =  {
{
	ARPHRD_ETHER, /* Ethernet */
	DN_DEV_BCAST,
	DN_DEV_S_RU,
	0,
	1498,
	1,
	10,
	0,
	"ethernet",
	NET_DECNET_CONF_ETHER,
	dn_eth_up,
	NULL,
	dn_send_brd_hello,
	NULL
},
{
	ARPHRD_IPGRE, /* DECnet tunneled over GRE in IP */
	DN_DEV_BCAST,
	DN_DEV_S_RU,
	0,
	1400,
	1,
	10,
	0,
	"ipgre",
	NET_DECNET_CONF_GRE,
	NULL,
	NULL,
	dn_send_brd_hello,
	NULL
},
#if 0
{
	ARPHRD_X25, /* Bog standard X.25 */
	DN_DEV_UCAST,
	DN_DEV_S_DS,
	0,
	230,
	1,
	120,
	0,
	"x25",
	NET_DECNET_CONF_X25,
	NULL,
	NULL,
	dn_send_ptp_hello,
	NULL
},
#endif
#if 0
{
	ARPHRD_PPP, /* DECnet over PPP */
	DN_DEV_BCAST,
	DN_DEV_S_RU,
	0,
	230,
	1,
	10,
	0,
	"ppp",
	NET_DECNET_CONF_PPP,
	NULL,
	NULL,
	dn_send_brd_hello,
	NULL
},
#endif
#if 0
{
	ARPHRD_DDCMP, /* DECnet over DDCMP */
	DN_DEV_UCAST,
	DN_DEV_S_DS,
	0,
	230,
	1,
	120,
	0,
	"ddcmp",
	NET_DECNET_CONF_DDCMP,
	NULL,
	NULL,
	dn_send_ptp_hello,
	NULL
},
#endif
{
	ARPHRD_LOOPBACK, /* Loopback interface - always last */
	DN_DEV_BCAST,
	DN_DEV_S_RU,
	0,
	1498,
	1,
	10,
	0,
	"loopback",
	NET_DECNET_CONF_LOOPBACK,
	NULL,
	NULL,
	dn_send_brd_hello,
	NULL
}
};

#define DN_DEV_LIST_SIZE (sizeof(dn_dev_list)/sizeof(struct dn_dev_parms))

#define DN_DEV_PARMS_OFFSET(x) ((int) ((char *) &((struct dn_dev_parms *)0)->x))

#ifdef CONFIG_SYSCTL

static int min_t2[] = { 1 };
static int max_t2[] = { 60 }; /* No max specified, but this seems sensible */
static int min_t3[] = { 1 };
static int max_t3[] = { 8191 }; /* Must fit in 16 bits when multiplied by BCT3MULT or T3MULT */

static int min_priority[] = { 0 };
static int max_priority[] = { 127 }; /* From DECnet spec */

static int dn_forwarding_proc(ctl_table *, int, struct file *,
			void *, size_t *);
static int dn_forwarding_sysctl(ctl_table *table, int *name, int nlen,
			void *oldval, size_t *oldlenp,
			void *newval, size_t newlen,
			void **context);

static struct dn_dev_sysctl_table {
	struct ctl_table_header *sysctl_header;
	ctl_table dn_dev_vars[5];
	ctl_table dn_dev_dev[2];
	ctl_table dn_dev_conf_dir[2];
	ctl_table dn_dev_proto_dir[2];
	ctl_table dn_dev_root_dir[2];
} dn_dev_sysctl = {
	NULL,
	{
	{NET_DECNET_CONF_DEV_FORWARDING, "forwarding",
	(void *)DN_DEV_PARMS_OFFSET(forwarding),
	sizeof(int), 0644, NULL,
	dn_forwarding_proc, dn_forwarding_sysctl,
	NULL, NULL, NULL},
	{NET_DECNET_CONF_DEV_PRIORITY, "priority",
	(void *)DN_DEV_PARMS_OFFSET(priority),
	sizeof(int), 0644, NULL,
	proc_dointvec_minmax, sysctl_intvec,
	NULL, &min_priority, &max_priority},
	{NET_DECNET_CONF_DEV_T2, "t2", (void *)DN_DEV_PARMS_OFFSET(t2),
	sizeof(int), 0644, NULL,
	proc_dointvec_minmax, sysctl_intvec,
	NULL, &min_t2, &max_t2},
	{NET_DECNET_CONF_DEV_T3, "t3", (void *)DN_DEV_PARMS_OFFSET(t3),
	sizeof(int), 0644, NULL,
	proc_dointvec_minmax, sysctl_intvec,
	NULL, &min_t3, &max_t3},
	{0}
	},
	{{0, "", NULL, 0, 0555, dn_dev_sysctl.dn_dev_vars}, {0}},
	{{NET_DECNET_CONF, "conf", NULL, 0, 0555, dn_dev_sysctl.dn_dev_dev}, {0}},
	{{NET_DECNET, "decnet", NULL, 0, 0555, dn_dev_sysctl.dn_dev_conf_dir}, {0}},
	{{CTL_NET, "net", NULL, 0, 0555, dn_dev_sysctl.dn_dev_proto_dir}, {0}}
};

static void dn_dev_sysctl_register(struct net_device *dev, struct dn_dev_parms *parms)
{
	struct dn_dev_sysctl_table *t;
	int i;

	t = kmalloc(sizeof(*t), GFP_KERNEL);
	if (t == NULL)
		return;

	memcpy(t, &dn_dev_sysctl, sizeof(*t));

	for(i = 0; i < (sizeof(t->dn_dev_vars)/sizeof(t->dn_dev_vars[0]) - 1); i++) {
		long offset = (long)t->dn_dev_vars[i].data;
		t->dn_dev_vars[i].data = ((char *)parms) + offset;
		t->dn_dev_vars[i].de = NULL;
	}

	if (dev) {
		t->dn_dev_dev[0].procname = dev->name;
		t->dn_dev_dev[0].ctl_name = dev->ifindex;
	} else {
		t->dn_dev_dev[0].procname = parms->name;
		t->dn_dev_dev[0].ctl_name = parms->ctl_name;
	}

	t->dn_dev_dev[0].child = t->dn_dev_vars;
	t->dn_dev_dev[0].de = NULL;
	t->dn_dev_conf_dir[0].child = t->dn_dev_dev;
	t->dn_dev_conf_dir[0].de = NULL;
	t->dn_dev_proto_dir[0].child = t->dn_dev_conf_dir;
	t->dn_dev_proto_dir[0].de = NULL;
	t->dn_dev_root_dir[0].child = t->dn_dev_proto_dir;
	t->dn_dev_root_dir[0].de = NULL;
	t->dn_dev_vars[0].extra1 = (void *)dev;

	t->sysctl_header = register_sysctl_table(t->dn_dev_root_dir, 0);
	if (t->sysctl_header == NULL)
		kfree(t);
	else
		parms->sysctl = t;
}

static void dn_dev_sysctl_unregister(struct dn_dev_parms *parms)
{
	if (parms->sysctl) {
		struct dn_dev_sysctl_table *t = parms->sysctl;
		parms->sysctl = NULL;
		unregister_sysctl_table(t->sysctl_header);
		kfree(t);
	}
}


static int dn_forwarding_proc(ctl_table *table, int write, 
				struct file *filep,
				void *buffer, size_t *lenp)
{
#ifdef CONFIG_DECNET_ROUTER
	struct net_device *dev = table->extra1;
	struct dn_dev *dn_db;
	int err;
	int tmp, old;

	if (table->extra1 == NULL)
		return -EINVAL;

	dn_db = dev->dn_ptr;
	old = dn_db->parms.forwarding;

	err = proc_dointvec(table, write, filep, buffer, lenp);

	if ((err >= 0) && write) {
		if (dn_db->parms.forwarding < 0)
			dn_db->parms.forwarding = 0;
		if (dn_db->parms.forwarding > 2)
			dn_db->parms.forwarding = 2;
		/*
		 * What an ugly hack this is... its works, just. It
		 * would be nice if sysctl/proc were just that little
		 * bit more flexible so I don't have to write a special
		 * routine, or suffer hacks like this - SJW
		 */
		tmp = dn_db->parms.forwarding;
		dn_db->parms.forwarding = old;
		if (dn_db->parms.down)
			dn_db->parms.down(dev);
		dn_db->parms.forwarding = tmp;
		if (dn_db->parms.up)
			dn_db->parms.up(dev);
	}

	return err;
#else
	return -EINVAL;
#endif
}

static int dn_forwarding_sysctl(ctl_table *table, int *name, int nlen,
			void *oldval, size_t *oldlenp,
			void *newval, size_t newlen,
			void **context)
{
#ifdef CONFIG_DECNET_ROUTER
	struct net_device *dev = table->extra1;
	struct dn_dev *dn_db;
	int value;

	if (table->extra1 == NULL)
		return -EINVAL;

	dn_db = dev->dn_ptr;

	if (newval && newlen) {
		if (newlen != sizeof(int))
			return -EINVAL;

		get_user(value, (int *)newval);
		if (value < 0)
			return -EINVAL;
		if (value > 2)
			return -EINVAL;

		if (dn_db->parms.down)
			dn_db->parms.down(dev);
		dn_db->parms.forwarding = value;
		if (dn_db->parms.up)
			dn_db->parms.up(dev);
	}

	return 0;
#else
	return -EINVAL;
#endif
}

#else /* CONFIG_SYSCTL */
static void dn_dev_sysctl_unregister(struct dn_dev_parms *parms)
{
}
static void dn_dev_sysctl_register(struct net_device *dev, struct dn_dev_parms *parms)
{
}

#endif /* CONFIG_SYSCTL */

static struct dn_ifaddr *dn_dev_alloc_ifa(void)
{
	struct dn_ifaddr *ifa;

	ifa = kmalloc(sizeof(*ifa), GFP_KERNEL);

	if (ifa) {
		memset(ifa, 0, sizeof(*ifa));
	}

	return ifa;
}

static __inline__ void dn_dev_free_ifa(struct dn_ifaddr *ifa)
{
	kfree(ifa);
}

static void dn_dev_del_ifa(struct dn_dev *dn_db, struct dn_ifaddr **ifap, int destroy)
{
	struct dn_ifaddr *ifa1 = *ifap;

	*ifap = ifa1->ifa_next;

#ifdef CONFIG_RTNETLINK
	rtmsg_ifa(RTM_DELADDR, ifa1);
#endif /* CONFIG_RTNETLINK */

	if (destroy) {
		dn_dev_free_ifa(ifa1);

		if (dn_db->ifa_list == NULL)
			dn_dev_delete(dn_db->dev);
	}
}

static int dn_dev_insert_ifa(struct dn_dev *dn_db, struct dn_ifaddr *ifa)
{
	/*
	 * FIXME: Duplicate check here.
	 */

	ifa->ifa_next = dn_db->ifa_list;
	dn_db->ifa_list = ifa;

#ifdef CONFIG_RTNETLINK
	rtmsg_ifa(RTM_NEWADDR, ifa);
#endif /* CONFIG_RTNETLINK */

	return 0;
}

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

	if (dn_db == NULL) {
		int err;
		dn_db = dn_dev_create(dev, &err);
		if (dn_db == NULL)
			return err;
	}

	ifa->ifa_dev = dn_db;

	if (dev->flags & IFF_LOOPBACK)
		ifa->ifa_scope = RT_SCOPE_HOST;

	return dn_dev_insert_ifa(dn_db, ifa);
}


int dn_dev_ioctl(unsigned int cmd, void *arg)
{
	char buffer[DN_IFREQ_SIZE];
	struct ifreq *ifr = (struct ifreq *)buffer;
	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 exclusive = 0;
	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;
			rtnl_lock();
			exclusive = 1;
			break;
		default:
			return -EINVAL;
	}

	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 = dn_saddr2dn(sdn);

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

	return ret;
rarok:
	if (copy_to_user(arg, ifr, DN_IFREQ_SIZE))
		return -EFAULT;

	return 0;
}

#ifdef CONFIG_RTNETLINK
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;

	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;

	memcpy(&ifa->ifa_local, RTA_DATA(rta[IFA_LOCAL-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);

	return dn_dev_insert_ifa(dn_db, ifa);
}

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;
	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);