1 files changed, 437 insertions, 0 deletions

diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
new file mode 100644
index 0000000..39d0aad
--- /dev/null
+++ b/net/ipv4/fib_rules.c
@@ -0,0 +1,437 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 Forwarding Information Base: policy rules.
+ *
+ * Version:	$Id: fib_rules.c,v 1.17 2001/10/31 21:55:54 davem Exp $
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ * 		Rani Assaf	:	local_rule cannot be deleted
+ *		Marc Boucher	:	routing by fwmark
+ */
+
+#include <linux/config.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+
+#define FRprintk(a...)
+
+struct fib_rule
+{
+	struct fib_rule *r_next;
+	atomic_t	r_clntref;
+	u32		r_preference;
+	unsigned char	r_table;
+	unsigned char	r_action;
+	unsigned char	r_dst_len;
+	unsigned char	r_src_len;
+	u32		r_src;
+	u32		r_srcmask;
+	u32		r_dst;
+	u32		r_dstmask;
+	u32		r_srcmap;
+	u8		r_flags;
+	u8		r_tos;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+	u32		r_fwmark;
+#endif
+	int		r_ifindex;
+#ifdef CONFIG_NET_CLS_ROUTE
+	__u32		r_tclassid;
+#endif
+	char		r_ifname[IFNAMSIZ];
+	int		r_dead;
+};
+
+static struct fib_rule default_rule = {
+	.r_clntref =	ATOMIC_INIT(2),
+	.r_preference =	0x7FFF,
+	.r_table =	RT_TABLE_DEFAULT,
+	.r_action =	RTN_UNICAST,
+};
+
+static struct fib_rule main_rule = {
+	.r_next =	&default_rule,
+	.r_clntref =	ATOMIC_INIT(2),
+	.r_preference =	0x7FFE,
+	.r_table =	RT_TABLE_MAIN,
+	.r_action =	RTN_UNICAST,
+};
+
+static struct fib_rule local_rule = {
+	.r_next =	&main_rule,
+	.r_clntref =	ATOMIC_INIT(2),
+	.r_table =	RT_TABLE_LOCAL,
+	.r_action =	RTN_UNICAST,
+};
+
+static struct fib_rule *fib_rules = &local_rule;
+static DEFINE_RWLOCK(fib_rules_lock);
+
+int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
+{
+	struct rtattr **rta = arg;
+	struct rtmsg *rtm = NLMSG_DATA(nlh);
+	struct fib_rule *r, **rp;
+	int err = -ESRCH;
+
+	for (rp=&fib_rules; (r=*rp) != NULL; rp=&r->r_next) {
+		if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) &&
+		    rtm->rtm_src_len == r->r_src_len &&
+		    rtm->rtm_dst_len == r->r_dst_len &&
+		    (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) &&
+		    rtm->rtm_tos == r->r_tos &&
+#ifdef CONFIG_IP_ROUTE_FWMARK
+		    (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
+#endif
+		    (!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
+		    (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
+		    (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
+		    (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
+			err = -EPERM;
+			if (r == &local_rule)
+				break;
+
+			write_lock_bh(&fib_rules_lock);
+			*rp = r->r_next;
+			r->r_dead = 1;
+			write_unlock_bh(&fib_rules_lock);
+			fib_rule_put(r);
+			err = 0;
+			break;
+		}
+	}
+	return err;
+}
+
+/* Allocate new unique table id */
+
+static struct fib_table *fib_empty_table(void)
+{
+	int id;
+
+	for (id = 1; id <= RT_TABLE_MAX; id++)
+		if (fib_tables[id] == NULL)
+			return __fib_new_table(id);
+	return NULL;
+}
+
+void fib_rule_put(struct fib_rule *r)
+{
+	if (atomic_dec_and_test(&r->r_clntref)) {
+		if (r->r_dead)
+			kfree(r);
+		else
+			printk("Freeing alive rule %p\n", r);
+	}
+}
+
+int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
+{
+	struct rtattr **rta = arg;
+	struct rtmsg *rtm = NLMSG_DATA(nlh);
+	struct fib_rule *r, *new_r, **rp;
+	unsigned char table_id;
+
+	if (rtm->rtm_src_len > 32 || rtm->rtm_dst_len > 32 ||
+	    (rtm->rtm_tos & ~IPTOS_TOS_MASK))
+		return -EINVAL;
+
+	if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
+		return -EINVAL;
+
+	table_id = rtm->rtm_table;
+	if (table_id == RT_TABLE_UNSPEC) {
+		struct fib_table *table;
+		if (rtm->rtm_type == RTN_UNICAST) {
+			if ((table = fib_empty_table()) == NULL)
+				return -ENOBUFS;
+			table_id = table->tb_id;
+		}
+	}
+
+	new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
+	if (!new_r)
+		return -ENOMEM;
+	memset(new_r, 0, sizeof(*new_r));
+	if (rta[RTA_SRC-1])
+		memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4);
+	if (rta[RTA_DST-1])
+		memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4);
+	if (rta[RTA_GATEWAY-1])
+		memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4);
+	new_r->r_src_len = rtm->rtm_src_len;
+	new_r->r_dst_len = rtm->rtm_dst_len;
+	new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len);
+	new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len);
+	new_r->r_tos = rtm->rtm_tos;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+	if (rta[RTA_PROTOINFO-1])
+		memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
+#endif
+	new_r->r_action = rtm->rtm_type;
+	new_r->r_flags = rtm->rtm_flags;
+	if (rta[RTA_PRIORITY-1])
+		memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
+	new_r->r_table = table_id;
+	if (rta[RTA_IIF-1]) {
+		struct net_device *dev;
+		rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
+		new_r->r_ifindex = -1;
+		dev = __dev_get_by_name(new_r->r_ifname);
+		if (dev)
+			new_r->r_ifindex = dev->ifindex;
+	}
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (rta[RTA_FLOW-1])
+		memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4);
+#endif
+
+	rp = &fib_rules;
+	if (!new_r->r_preference) {
+		r = fib_rules;
+		if (r && (r = r->r_next) != NULL) {
+			rp = &fib_rules->r_next;
+			if (r->r_preference)
+				new_r->r_preference = r->r_preference - 1;
+		}
+	}
+
+	while ( (r = *rp) != NULL ) {
+		if (r->r_preference > new_r->r_preference)
+			break;
+		rp = &r->r_next;
+	}
+
+	new_r->r_next = r;
+	atomic_inc(&new_r->r_clntref);
+	write_lock_bh(&fib_rules_lock);
+	*rp = new_r;
+	write_unlock_bh(&fib_rules_lock);
+	return 0;
+}
+
+#ifdef CONFIG_NET_CLS_ROUTE
+u32 fib_rules_tclass(struct fib_result *res)
+{
+	if (res->r)
+		return res->r->r_tclassid;
+	return 0;
+}
+#endif
+
+
+static void fib_rules_detach(struct net_device *dev)
+{
+	struct fib_rule *r;
+
+	for (r=fib_rules; r; r=r->r_next) {
+		if (r->r_ifindex == dev->ifindex) {
+			write_lock_bh(&fib_rules_lock);
+			r->r_ifindex = -1;
+			write_unlock_bh(&fib_rules_lock);
+		}
+	}
+}
+
+static void fib_rules_attach(struct net_device *dev)
+{
+	struct fib_rule *r;
+
+	for (r=fib_rules; r; r=r->r_next) {
+		if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) {
+			write_lock_bh(&fib_rules_lock);
+			r->r_ifindex = dev->ifindex;
+			write_unlock_bh(&fib_rules_lock);
+		}
+	}
+}
+
+int fib_lookup(const struct flowi *flp, struct fib_result *res)
+{
+	int err;
+	struct fib_rule *r, *policy;
+	struct fib_table *tb;
+
+	u32 daddr = flp->fl4_dst;
+	u32 saddr = flp->fl4_src;
+
+FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ",
+	NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src));
+	read_lock(&fib_rules_lock);
+	for (r = fib_rules; r; r=r->r_next) {
+		if (((saddr^r->r_src) & r->r_srcmask) ||
+		    ((daddr^r->r_dst) & r->r_dstmask) ||
+		    (r->r_tos && r->r_tos != flp->fl4_tos) ||
+#ifdef CONFIG_IP_ROUTE_FWMARK
+		    (r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) ||
+#endif
+		    (r->r_ifindex && r->r_ifindex != flp->iif))
+			continue;
+
+FRprintk("tb %d r %d ", r->r_table, r->r_action);
+		switch (r->r_action) {
+		case RTN_UNICAST:
+			policy = r;
+			break;
+		case RTN_UNREACHABLE:
+			read_unlock(&fib_rules_lock);
+			return -ENETUNREACH;
+		default:
+		case RTN_BLACKHOLE:
+			read_unlock(&fib_rules_lock);
+			return -EINVAL;
+		case RTN_PROHIBIT:
+			read_unlock(&fib_rules_lock);
+			return -EACCES;
+		}
+
+		if ((tb = fib_get_table(r->r_table)) == NULL)
+			continue;
+		err = tb->tb_lookup(tb, flp, res);
+		if (err == 0) {
+			res->r = policy;
+			if (policy)
+				atomic_inc(&policy->r_clntref);
+			read_unlock(&fib_rules_lock);
+			return 0;
+		}
+		if (err < 0 && err != -EAGAIN) {
+			read_unlock(&fib_rules_lock);
+			return err;
+		}
+	}
+FRprintk("FAILURE\n");
+	read_unlock(&fib_rules_lock);
+	return -ENETUNREACH;
+}
+
+void fib_select_default(const struct flowi *flp, struct fib_result *res)
+{
+	if (res->r && res->r->r_action == RTN_UNICAST &&
+	    FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
+		struct fib_table *tb;
+		if ((tb = fib_get_table(res->r->r_table)) != NULL)
+			tb->tb_select_default(tb, flp, res);
+	}
+}
+
+static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+
+	if (event == NETDEV_UNREGISTER)
+		fib_rules_detach(dev);
+	else if (event == NETDEV_REGISTER)
+		fib_rules_attach(dev);
+	return NOTIFY_DONE;
+}
+
+
+static struct notifier_block fib_rules_notifier = {
+	.notifier_call =fib_rules_event,
+};
+
+static __inline__ int inet_fill_rule(struct sk_buff *skb,
+				     struct fib_rule *r,
+				     struct netlink_callback *cb)
+{
+	struct rtmsg *rtm;
+	struct nlmsghdr  *nlh;
+	unsigned char	 *b = skb->tail;
+
+	nlh = NLMSG_PUT(skb, NETLINK_CREDS(cb->skb)->pid, cb->nlh->nlmsg_seq, RTM_NEWRULE, sizeof(*rtm));
+	rtm = NLMSG_DATA(nlh);
+	rtm->rtm_family = AF_INET;
+	rtm->rtm_dst_len = r->r_dst_len;
+	rtm->rtm_src_len = r->r_src_len;
+	rtm->rtm_tos = r->r_tos;
+#ifdef CONFIG_IP_ROUTE_FWMARK
+	if (r->r_fwmark)
+		RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
+#endif
+	rtm->rtm_table = r->r_table;
+	rtm->rtm_protocol = 0;
+	rtm->rtm_scope = 0;
+	rtm->rtm_type = r->r_action;
+	rtm->rtm_flags = r->r_flags;
+
+	if (r->r_dst_len)
+		RTA_PUT(skb, RTA_DST, 4, &r->r_dst);
+	if (r->r_src_len)
+		RTA_PUT(skb, RTA_SRC, 4, &r->r_src);
+	if (r->r_ifname[0])
+		RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
+	if (r->r_preference)
+		RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
+	if (r->r_srcmap)
+		RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap);
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (r->r_tclassid)
+		RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid);
+#endif
+	nlh->nlmsg_len = skb->tail - b;
+	return skb->len;
+
+nlmsg_failure:
+rtattr_failure:
+	skb_trim(skb, b - skb->data);
+	return -1;
+}
+
+int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int idx;
+	int s_idx = cb->args[0];
+	struct fib_rule *r;
+
+	read_lock(&fib_rules_lock);
+	for (r=fib_rules, idx=0; r; r = r->r_next, idx++) {
+		if (idx < s_idx)
+			continue;
+		if (inet_fill_rule(skb, r, cb) < 0)
+			break;
+	}
+	read_unlock(&fib_rules_lock);
+	cb->args[0] = idx;
+
+	return skb->len;
+}
+
+void __init fib_rules_init(void)
+{
+	register_netdevice_notifier(&fib_rules_notifier);
+}