Release 4.11 net/decnet/dn_fib.c

/*
 * 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 Routing Forwarding Information Base (Glue/Info List)
 *
 * Author:      Steve Whitehouse <SteveW@ACM.org>
 *
 *
 * Changes:
 *              Alexey Kuznetsov : SMP locking changes
 *              Steve Whitehouse : Rewrote it... Well to be more correct, I
 *                                 copied most of it from the ipv4 fib code.
 *              Steve Whitehouse : Updated it in style and fixed a few bugs
 *                                 which were fixed in the ipv4 code since
 *                                 this code was copied from it.
 *
 */
#include <linux/string.h>
#include <linux/net.h>
#include <linux/socket.h>
#include <linux/slab.h>
#include <linux/sockios.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/proc_fs.h>
#include <linux/netdevice.h>
#include <linux/timer.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
#include <linux/uaccess.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/fib_rules.h>
#include <net/dn.h>
#include <net/dn_route.h>
#include <net/dn_fib.h>
#include <net/dn_neigh.h>
#include <net/dn_dev.h>
#include <net/nexthop.h>


#define RT_MIN_TABLE 1


#define for_fib_info() { struct dn_fib_info *fi;\
        for(fi = dn_fib_info_list; fi; fi = fi->fib_next)

#define endfor_fib_info() }


#define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;\
        for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)


#define change_nexthops(fi) { int nhsel; struct dn_fib_nh *nh;\
        for(nhsel = 0, nh = (struct dn_fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)


#define endfor_nexthops(fi) }

static DEFINE_SPINLOCK(dn_fib_multipath_lock);

static struct dn_fib_info *dn_fib_info_list;
static DEFINE_SPINLOCK(dn_fib_info_lock);

static struct
{
	
int error;
	
u8 scope;
} 
dn_fib_props[RTN_MAX+1] = {
	[RTN_UNSPEC] =      { .error = 0,       .scope = RT_SCOPE_NOWHERE },
	[RTN_UNICAST] =     { .error = 0,       .scope = RT_SCOPE_UNIVERSE },
	[RTN_LOCAL] =       { .error = 0,       .scope = RT_SCOPE_HOST },
	[RTN_BROADCAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
	[RTN_ANYCAST] =     { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
	[RTN_MULTICAST] =   { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
	[RTN_BLACKHOLE] =   { .error = -EINVAL, .scope = RT_SCOPE_UNIVERSE },
	[RTN_UNREACHABLE] = { .error = -EHOSTUNREACH, .scope = RT_SCOPE_UNIVERSE },
	[RTN_PROHIBIT] =    { .error = -EACCES, .scope = RT_SCOPE_UNIVERSE },
	[RTN_THROW] =       { .error = -EAGAIN, .scope = RT_SCOPE_UNIVERSE },
	[RTN_NAT] =         { .error = 0,       .scope = RT_SCOPE_NOWHERE },
	[RTN_XRESOLVE] =    { .error = -EINVAL, .scope = RT_SCOPE_NOWHERE },
};

static int dn_fib_sync_down(__le16 local, struct net_device *dev, int force);
static int dn_fib_sync_up(struct net_device *dev);



void dn_fib_free_info(struct dn_fib_info *fi)
{
	if (fi->fib_dead == 0) {
		printk(KERN_DEBUG "DECnet: BUG! Attempt to free alive dn_fib_info\n");
		return;
	}

	change_nexthops(fi) {
		if (nh->nh_dev)
			dev_put(nh->nh_dev);
		nh->nh_dev = NULL;
	} endfor_nexthops(fi);
	kfree(fi);
}

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void dn_fib_release_info(struct dn_fib_info *fi)
{
	spin_lock(&dn_fib_info_lock);
	if (fi && --fi->fib_treeref == 0) {
		if (fi->fib_next)
			fi->fib_next->fib_prev = fi->fib_prev;
		if (fi->fib_prev)
			fi->fib_prev->fib_next = fi->fib_next;
		if (fi == dn_fib_info_list)
			dn_fib_info_list = fi->fib_next;
		fi->fib_dead = 1;
		dn_fib_info_put(fi);
	}
	spin_unlock(&dn_fib_info_lock);
}

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2.22%
1
33.33%
Total
90
100.00%
3
100.00%



static inline int dn_fib_nh_comp(const struct dn_fib_info *fi, const struct dn_fib_info *ofi)
{
	const struct dn_fib_nh *onh = ofi->fib_nh;

	for_nexthops(fi) {
		if (nh->nh_oif != onh->nh_oif ||
			nh->nh_gw != onh->nh_gw ||
			nh->nh_scope != onh->nh_scope ||
			nh->nh_weight != onh->nh_weight ||
			((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
				return -1;
		onh++;
	} endfor_nexthops(fi);
	return 0;
}

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98.99%
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1
1.01%
1
33.33%
Total
99
100.00%
3
100.00%



static inline struct dn_fib_info *dn_fib_find_info(const struct dn_fib_info *nfi)
{
	for_fib_info() {
		if (fi->fib_nhs != nfi->fib_nhs)
			continue;
		if (nfi->fib_protocol == fi->fib_protocol &&
			nfi->fib_prefsrc == fi->fib_prefsrc &&
			nfi->fib_priority == fi->fib_priority &&
			memcmp(nfi->fib_metrics, fi->fib_metrics, sizeof(fi->fib_metrics)) == 0 &&
			((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
			(nfi->fib_nhs == 0 || dn_fib_nh_comp(fi, nfi) == 0))
				return fi;
	} endfor_fib_info();
	return NULL;
}

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Linus Torvalds (pre-git)
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66.67%
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31
26.05%
1
33.33%
Total
119
100.00%
3
100.00%



static int dn_fib_count_nhs(const struct nlattr *attr)
{
	struct rtnexthop *nhp = nla_data(attr);
	int nhs = 0, nhlen = nla_len(attr);

	while (rtnh_ok(nhp, nhlen)) {
		nhs++;
		nhp = rtnh_next(nhp, &nhlen);
	}

	/* leftover implies invalid nexthop configuration, discard it */
	return nhlen > 0 ? 0 : nhs;
}

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61.76%
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Vegard Nossum
15
22.06%
1
25.00%
Thomas Graf
11
16.18%
1
25.00%
Total
68
100.00%
4
100.00%



static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct nlattr *attr,
			  const struct rtmsg *r)
{
	struct rtnexthop *nhp = nla_data(attr);
	int nhlen = nla_len(attr);

	change_nexthops(fi) {
		int attrlen;

		if (!rtnh_ok(nhp, nhlen))
			return -EINVAL;

		nh->nh_flags  = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
		nh->nh_oif    = nhp->rtnh_ifindex;
		nh->nh_weight = nhp->rtnh_hops + 1;

		attrlen = rtnh_attrlen(nhp);
		if (attrlen > 0) {
			struct nlattr *gw_attr;

			gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
			nh->nh_gw = gw_attr ? nla_get_le16(gw_attr) : 0;
		}

		nhp = rtnh_next(nhp, &nhlen);
	} endfor_nexthops(fi);

	return 0;
}


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Linus Torvalds (pre-git)
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68.24%
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50.00%
Thomas Graf
35
20.59%
1
25.00%
Vegard Nossum
19
11.18%
1
25.00%
Total
170
100.00%
4
100.00%



static int dn_fib_check_nh(const struct rtmsg *r, struct dn_fib_info *fi, struct dn_fib_nh *nh)
{
	int err;

	if (nh->nh_gw) {
		struct flowidn fld;
		struct dn_fib_res res;

		if (nh->nh_flags&RTNH_F_ONLINK) {
			struct net_device *dev;

			if (r->rtm_scope >= RT_SCOPE_LINK)
				return -EINVAL;
			if (dnet_addr_type(nh->nh_gw) != RTN_UNICAST)
				return -EINVAL;
			if ((dev = __dev_get_by_index(&init_net, nh->nh_oif)) == NULL)
				return -ENODEV;
			if (!(dev->flags&IFF_UP))
				return -ENETDOWN;
			nh->nh_dev = dev;
			dev_hold(dev);
			nh->nh_scope = RT_SCOPE_LINK;
			return 0;
		}

		memset(&fld, 0, sizeof(fld));
		fld.daddr = nh->nh_gw;
		fld.flowidn_oif = nh->nh_oif;
		fld.flowidn_scope = r->rtm_scope + 1;

		if (fld.flowidn_scope < RT_SCOPE_LINK)
			fld.flowidn_scope = RT_SCOPE_LINK;

		if ((err = dn_fib_lookup(&fld, &res)) != 0)
			return err;

		err = -EINVAL;
		if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
			goto out;
		nh->nh_scope = res.scope;
		nh->nh_oif = DN_FIB_RES_OIF(res);
		nh->nh_dev = DN_FIB_RES_DEV(res);
		if (nh->nh_dev == NULL)
			goto out;
		dev_hold(nh->nh_dev);
		err = -ENETDOWN;
		if (!(nh->nh_dev->flags & IFF_UP))
			goto out;
		err = 0;
out:
		dn_fib_res_put(&res);
		return err;
	} else {
		struct net_device *dev;

		if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
			return -EINVAL;

		dev = __dev_get_by_index(&init_net, nh->nh_oif);
		if (dev == NULL || dev->dn_ptr == NULL)
			return -ENODEV;
		if (!(dev->flags&IFF_UP))
			return -ENETDOWN;
		nh->nh_dev = dev;
		dev_hold(nh->nh_dev);
		nh->nh_scope = RT_SCOPE_HOST;
	}

	return 0;
}


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Linus Torvalds (pre-git)
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33.33%
Steven Whitehouse
72
17.82%
1
16.67%
David S. Miller
15
3.71%
1
16.67%
Eric W. Biedermann
6
1.49%
1
16.67%
Stephen Hemminger
3
0.74%
1
16.67%
Total
404
100.00%
6
100.00%



struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *attrs[],
				       const struct nlmsghdr *nlh, int *errp)
{
	int err;
	struct dn_fib_info *fi = NULL;
	struct dn_fib_info *ofi;
	int nhs = 1;

	if (r->rtm_type > RTN_MAX)
		goto err_inval;

	if (dn_fib_props[r->rtm_type].scope > r->rtm_scope)
		goto err_inval;

	if (attrs[RTA_MULTIPATH] &&
	    (nhs = dn_fib_count_nhs(attrs[RTA_MULTIPATH])) == 0)
		goto err_inval;

	fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct dn_fib_nh), GFP_KERNEL);
	err = -ENOBUFS;
	if (fi == NULL)
		goto failure;

	fi->fib_protocol = r->rtm_protocol;
	fi->fib_nhs = nhs;
	fi->fib_flags = r->rtm_flags;

	if (attrs[RTA_PRIORITY])
		fi->fib_priority = nla_get_u32(attrs[RTA_PRIORITY]);

	if (attrs[RTA_METRICS]) {
		struct nlattr *attr;
		int rem;

		nla_for_each_nested(attr, attrs[RTA_METRICS], rem) {
			int type = nla_type(attr);

			if (type) {
				if (type > RTAX_MAX || type == RTAX_CC_ALGO ||
				    nla_len(attr) < 4)
					goto err_inval;

				fi->fib_metrics[type-1] = nla_get_u32(attr);
			}
		}
	}

	if (attrs[RTA_PREFSRC])
		fi->fib_prefsrc = nla_get_le16(attrs[RTA_PREFSRC]);

	if (attrs[RTA_MULTIPATH]) {
		if ((err = dn_fib_get_nhs(fi, attrs[RTA_MULTIPATH], r)) != 0)
			goto failure;

		if (attrs[RTA_OIF] &&
		    fi->fib_nh->nh_oif != nla_get_u32(attrs[RTA_OIF]))
			goto err_inval;

		if (attrs[RTA_GATEWAY] &&
		    fi->fib_nh->nh_gw != nla_get_le16(attrs[RTA_GATEWAY]))
			goto err_inval;
	} else {
		struct dn_fib_nh *nh = fi->fib_nh;

		if (attrs[RTA_OIF])
			nh->nh_oif = nla_get_u32(attrs[RTA_OIF]);

		if (attrs[RTA_GATEWAY])
			nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);

		nh->nh_flags = r->rtm_flags;
		nh->nh_weight = 1;
	}

	if (r->rtm_type == RTN_NAT) {
		if (!attrs[RTA_GATEWAY] || nhs != 1 || attrs[RTA_OIF])
			goto err_inval;

		fi->fib_nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
		goto link_it;
	}

	if (dn_fib_props[r->rtm_type].error) {
		if (attrs[RTA_GATEWAY] || attrs[RTA_OIF] || attrs[RTA_MULTIPATH])
			goto err_inval;

		goto link_it;
	}

	if (r->rtm_scope > RT_SCOPE_HOST)
		goto err_inval;

	if (r->rtm_scope == RT_SCOPE_HOST) {
		struct dn_fib_nh *nh = fi->fib_nh;

		/* Local address is added */
		if (nhs != 1 || nh->nh_gw)
			goto err_inval;
		nh->nh_scope = RT_SCOPE_NOWHERE;
		nh->nh_dev = dev_get_by_index(&init_net, fi->fib_nh->nh_oif);
		err = -ENODEV;
		if (nh->nh_dev == NULL)
			goto failure;
	} else {
		change_nexthops(fi) {
			if ((err = dn_fib_check_nh(r, fi, nh)) != 0)
				goto failure;
		} endfor_nexthops(fi)
	}

	if (fi->fib_prefsrc) {
		if (r->rtm_type != RTN_LOCAL || !attrs[RTA_DST] ||
		    fi->fib_prefsrc != nla_get_le16(attrs[RTA_DST]))
			if (dnet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
				goto err_inval;
	}

link_it:
	if ((ofi = dn_fib_find_info(fi)) != NULL) {
		fi->fib_dead = 1;
		dn_fib_free_info(fi);
		ofi->fib_treeref++;
		return ofi;
	}

	fi->fib_treeref++;
	atomic_inc(&fi->fib_clntref);
	spin_lock(&dn_fib_info_lock);
	fi->fib_next = dn_fib_info_list;
	fi->fib_prev = NULL;
	if (dn_fib_info_list)
		dn_fib_info_list->fib_prev