dn_dev.c

linux 内核源代码

/*
 * 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 - it's a user space issue now
 *         Patrick Caulfield : Fixed router hello message format
 *          Steve Whitehouse : Got rid of constant sizes for blksize for
 *                             devices. All mtu based now.
 */

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/if_addr.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/sysctl.h>
#include <linux/notifier.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <net/net_namespace.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/fib_rules.h>
#include <net/netlink.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;

/*
 * decnet_address is kept in network order.
 */
__le16 decnet_address = 0;

static DEFINE_RWLOCK(dndev_lock);
static struct net_device *decnet_default_device;
static BLOCKING_NOTIFIER_HEAD(dnaddr_chain);

static struct dn_dev *dn_dev_create(struct net_device *dev, int *err);
static void dn_dev_delete(struct net_device *dev);
static void dn_ifaddr_notify(int event, struct dn_ifaddr *ifa);

static int dn_eth_up(struct net_device *);
static void dn_eth_down(struct net_device *);
static void dn_send_brd_hello(struct net_device *dev, struct dn_ifaddr *ifa);
static void dn_send_ptp_hello(struct net_device *dev, struct dn_ifaddr *ifa);

static struct dn_dev_parms dn_dev_list[] =  {
{
	.type =		ARPHRD_ETHER, /* Ethernet */
	.mode =		DN_DEV_BCAST,
	.state =	DN_DEV_S_RU,
	.t2 =		1,
	.t3 =		10,
	.name =		"ethernet",
	.ctl_name =	NET_DECNET_CONF_ETHER,
	.up =		dn_eth_up,
	.down = 	dn_eth_down,
	.timer3 =	dn_send_brd_hello,
},
{
	.type =		ARPHRD_IPGRE, /* DECnet tunneled over GRE in IP */
	.mode =		DN_DEV_BCAST,
	.state =	DN_DEV_S_RU,
	.t2 =		1,
	.t3 =		10,
	.name =		"ipgre",
	.ctl_name =	NET_DECNET_CONF_GRE,
	.timer3 =	dn_send_brd_hello,
},
#if 0
{
	.type =		ARPHRD_X25, /* Bog standard X.25 */
	.mode =		DN_DEV_UCAST,
	.state =	DN_DEV_S_DS,
	.t2 =		1,
	.t3 =		120,
	.name =		"x25",
	.ctl_name =	NET_DECNET_CONF_X25,
	.timer3 =	dn_send_ptp_hello,
},
#endif
#if 0
{
	.type =		ARPHRD_PPP, /* DECnet over PPP */
	.mode =		DN_DEV_BCAST,
	.state =	DN_DEV_S_RU,
	.t2 =		1,
	.t3 =		10,
	.name =		"ppp",
	.ctl_name =	NET_DECNET_CONF_PPP,
	.timer3 =	dn_send_brd_hello,
},
#endif
{
	.type =		ARPHRD_DDCMP, /* DECnet over DDCMP */
	.mode =		DN_DEV_UCAST,
	.state =	DN_DEV_S_DS,
	.t2 =		1,
	.t3 =		120,
	.name =		"ddcmp",
	.ctl_name =	NET_DECNET_CONF_DDCMP,
	.timer3 =	dn_send_ptp_hello,
},
{
	.type =		ARPHRD_LOOPBACK, /* Loopback interface - always last */
	.mode =		DN_DEV_BCAST,
	.state =	DN_DEV_S_RU,
	.t2 =		1,
	.t3 =		10,
	.name =		"loopback",
	.ctl_name =	NET_DECNET_CONF_LOOPBACK,
	.timer3 =	dn_send_brd_hello,
}
};

#define DN_DEV_LIST_SIZE ARRAY_SIZE(dn_dev_list)

#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[1];
static int max_priority[] = { 127 }; /* From DECnet spec */

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

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,
	{
	{
		.ctl_name = NET_DECNET_CONF_DEV_FORWARDING,
		.procname = "forwarding",
		.data = (void *)DN_DEV_PARMS_OFFSET(forwarding),
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = dn_forwarding_proc,
		.strategy = dn_forwarding_sysctl,
	},
	{
		.ctl_name = NET_DECNET_CONF_DEV_PRIORITY,
		.procname = "priority",
		.data = (void *)DN_DEV_PARMS_OFFSET(priority),
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = proc_dointvec_minmax,
		.strategy = sysctl_intvec,
		.extra1 = &min_priority,
		.extra2 = &max_priority
	},
	{
		.ctl_name = NET_DECNET_CONF_DEV_T2,
		.procname = "t2",
		.data = (void *)DN_DEV_PARMS_OFFSET(t2),
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = proc_dointvec_minmax,
		.strategy = sysctl_intvec,
		.extra1 = &min_t2,
		.extra2 = &max_t2
	},
	{
		.ctl_name = NET_DECNET_CONF_DEV_T3,
		.procname = "t3",
		.data = (void *)DN_DEV_PARMS_OFFSET(t3),
		.maxlen = sizeof(int),
		.mode = 0644,
		.proc_handler = proc_dointvec_minmax,
		.strategy = sysctl_intvec,
		.extra1 = &min_t3,
		.extra2 = &max_t3
	},
	{0}
	},
	{{
		.ctl_name = 0,
		.procname = "",
		.mode = 0555,
		.child = dn_dev_sysctl.dn_dev_vars
	}, {0}},
	{{
		.ctl_name = NET_DECNET_CONF,
		.procname = "conf",
		.mode = 0555,
		.child = dn_dev_sysctl.dn_dev_dev
	}, {0}},
	{{
		.ctl_name = NET_DECNET,
		.procname = "decnet",
		.mode = 0555,
		.child = dn_dev_sysctl.dn_dev_conf_dir
	}, {0}},
	{{
		.ctl_name = CTL_NET,
		.procname = "net",
		.mode = 0555,
		.child = 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 = kmemdup(&dn_dev_sysctl, sizeof(*t), GFP_KERNEL);
	if (t == NULL)
		return;

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

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

	t->sysctl_header = register_sysctl_table(t->dn_dev_root_dir);
	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 __user *buffer,
				size_t *lenp, loff_t *ppos)
{
#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, ppos);

	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 __user *name, int nlen,
			void __user *oldval, size_t __user *oldlenp,
			void __user *newval, size_t newlen)
{
#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;

		if (get_user(value, (int __user *)newval))
			return -EFAULT;
		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 inline __u16 mtu2blksize(struct net_device *dev)
{
	u32 blksize = dev->mtu;
	if (blksize > 0xffff)
		blksize = 0xffff;

	if (dev->type == ARPHRD_ETHER ||
	    dev->type == ARPHRD_PPP ||
	    dev->type == ARPHRD_IPGRE ||
	    dev->type == ARPHRD_LOOPBACK)
		blksize -= 2;

	return (__u16)blksize;
}

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

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

	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;
	unsigned char mac_addr[6];
	struct net_device *dev = dn_db->dev;

	ASSERT_RTNL();

	*ifap = ifa1->ifa_next;

	if (dn_db->dev->type == ARPHRD_ETHER) {
		if (ifa1->ifa_local != dn_eth2dn(dev->dev_addr)) {
			dn_dn2eth(mac_addr, ifa1->ifa_local);
			dev_mc_delete(dev, mac_addr, ETH_ALEN, 0);
		}
	}

	dn_ifaddr_notify(RTM_DELADDR, ifa1);
	blocking_notifier_call_chain(&dnaddr_chain, NETDEV_DOWN, ifa1);
	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)
{
	struct net_device *dev = dn_db->dev;
	struct dn_ifaddr *ifa1;
	unsigned char mac_addr[6];

	ASSERT_RTNL();

	/* Check for duplicates */
	for(ifa1 = dn_db->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
		if (ifa1->ifa_local == ifa->ifa_local)
			return -EEXIST;
	}

	if (dev->type == ARPHRD_ETHER) {
		if (ifa->ifa_local != dn_eth2dn(dev->dev_addr)) {
			dn_dn2eth(mac_addr, ifa->ifa_local);
			dev_mc_add(dev, mac_addr, ETH_ALEN, 0);
		}
	}

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

	dn_ifaddr_notify(RTM_NEWADDR, ifa);
	blocking_notifier_call_chain(&dnaddr_chain, NETDEV_UP, ifa);

	return 0;
}

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

	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;

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