[PATCH 07/10] netfilter: ipset: Remove rbtree from hash:net,iface in order to run under RCU

[Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>]

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
---
 net/netfilter/ipset/ip_set_hash_netiface.c | 156 ++++-------------------------
 1 file changed, 17 insertions(+), 139 deletions(-)

diff --git a/net/netfilter/ipset/ip_set_hash_netiface.c b/net/netfilter/ipset/ip_set_hash_netiface.c
index 758b002..d8a53ec 100644
--- a/net/netfilter/ipset/ip_set_hash_netiface.c
+++ b/net/netfilter/ipset/ip_set_hash_netiface.c
@@ -13,7 +13,6 @@
 #include <linux/skbuff.h>
 #include <linux/errno.h>
 #include <linux/random.h>
-#include <linux/rbtree.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
 #include <net/netlink.h>
@@ -36,88 +35,14 @@ MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>");
 IP_SET_MODULE_DESC("hash:net,iface", IPSET_TYPE_REV_MIN, IPSET_TYPE_REV_MAX);
 MODULE_ALIAS("ip_set_hash:net,iface");
 
-/* Interface name rbtree */
-
-struct iface_node {
-	struct rb_node node;
-	char iface[IFNAMSIZ];
-};
-
-#define iface_data(n)	(rb_entry(n, struct iface_node, node)->iface)
-
-static void
-rbtree_destroy(struct rb_root *root)
-{
-	struct iface_node *node, *next;
-
-	rbtree_postorder_for_each_entry_safe(node, next, root, node)
-		kfree(node);
-
-	*root = RB_ROOT;
-}
-
-static int
-iface_test(struct rb_root *root, const char **iface)
-{
-	struct rb_node *n = root->rb_node;
-
-	while (n) {
-		const char *d = iface_data(n);
-		int res = strcmp(*iface, d);
-
-		if (res < 0)
-			n = n->rb_left;
-		else if (res > 0)
-			n = n->rb_right;
-		else {
-			*iface = d;
-			return 1;
-		}
-	}
-	return 0;
-}
-
-static int
-iface_add(struct rb_root *root, const char **iface)
-{
-	struct rb_node **n = &(root->rb_node), *p = NULL;
-	struct iface_node *d;
-
-	while (*n) {
-		char *ifname = iface_data(*n);
-		int res = strcmp(*iface, ifname);
-
-		p = *n;
-		if (res < 0)
-			n = &((*n)->rb_left);
-		else if (res > 0)
-			n = &((*n)->rb_right);
-		else {
-			*iface = ifname;
-			return 0;
-		}
-	}
-
-	d = kzalloc(sizeof(*d), GFP_ATOMIC);
-	if (!d)
-		return -ENOMEM;
-	strcpy(d->iface, *iface);
-
-	rb_link_node(&d->node, p, n);
-	rb_insert_color(&d->node, root);
-
-	*iface = d->iface;
-	return 0;
-}
-
 /* Type specific function prefix */
 #define HTYPE		hash_netiface
 #define IP_SET_HASH_WITH_NETS
-#define IP_SET_HASH_WITH_RBTREE
 #define IP_SET_HASH_WITH_MULTI
 #define IP_SET_HASH_WITH_NET0
 
 #define STREQ(a, b)	(strcmp(a, b) == 0)
+#define IFNAMCPY(a, b)	strncpy(a, b, IFNAMSIZ)
 
 /* IPv4 variant */
 
@@ -136,7 +61,7 @@ struct hash_netiface4_elem {
 	u8 cidr;
 	u8 nomatch;
 	u8 elem;
-	const char *iface;
+	char iface[IFNAMSIZ];
 };
 
 /* Common functions */
@@ -150,7 +75,7 @@ hash_netiface4_data_equal(const struct hash_netiface4_elem *ip1,
 	       ip1->cidr == ip2->cidr &&
 	       (++*multi) &&
 	       ip1->physdev == ip2->physdev &&
-	       ip1->iface == ip2->iface;
+	       STREQ(ip1->iface, ip2->iface);
 }
 
 static inline int
@@ -223,7 +148,6 @@ hash_netiface4_kadt(struct ip_set *set, const struct sk_buff *skb,
 		.elem = 1,
 	};
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
-	int ret;
 
 	if (e.cidr == 0)
 		return -EINVAL;
@@ -233,8 +157,8 @@ hash_netiface4_kadt(struct ip_set *set, const struct sk_buff *skb,
 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
 	e.ip &= ip_set_netmask(e.cidr);
 
-#define IFACE(dir)	(par->dir ? par->dir->name : NULL)
-#define PHYSDEV(dir)	(nf_bridge->dir ? nf_bridge->dir->name : NULL)
+#define IFACE(dir)	(par->dir ? par->dir->name : "")
+#define PHYSDEV(dir)	(nf_bridge->dir ? nf_bridge->dir->name : "")
 #define SRCDIR		(opt->flags & IPSET_DIM_TWO_SRC)
 
 	if (opt->cmdflags & IPSET_FLAG_PHYSDEV) {
@@ -243,26 +167,15 @@ hash_netiface4_kadt(struct ip_set *set, const struct sk_buff *skb,
 
 		if (!nf_bridge)
 			return -EINVAL;
-		e.iface = SRCDIR ? PHYSDEV(physindev) : PHYSDEV(physoutdev);
+		IFNAMCPY(e.iface,
+			 SRCDIR ? PHYSDEV(physindev) : PHYSDEV(physoutdev));
 		e.physdev = 1;
-#else
-		e.iface = NULL;
 #endif
 	} else
-		e.iface = SRCDIR ? IFACE(in) : IFACE(out);
+		IFNAMCPY(e.iface, SRCDIR ? IFACE(in) : IFACE(out));
 
-	if (!e.iface)
+	if (strlen(e.iface) == 0)
 		return -EINVAL;
-	ret = iface_test(&h->rbtree, &e.iface);
-	if (adt == IPSET_ADD) {
-		if (!ret) {
-			ret = iface_add(&h->rbtree, &e.iface);
-			if (ret)
-				return ret;
-		}
-	} else if (!ret)
-		return ret;
-
 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
 }
 
@@ -275,7 +188,6 @@ hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
 	struct hash_netiface4_elem e = { .cidr = HOST_MASK, .elem = 1 };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
 	u32 ip = 0, ip_to = 0, last;
-	char iface[IFNAMSIZ];
 	int ret;
 
 	if (unlikely(!tb[IPSET_ATTR_IP] ||
@@ -302,18 +214,7 @@ hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
 		if (e.cidr > HOST_MASK)
 			return -IPSET_ERR_INVALID_CIDR;
 	}
-
-	strcpy(iface, nla_data(tb[IPSET_ATTR_IFACE]));
-	e.iface = iface;
-	ret = iface_test(&h->rbtree, &e.iface);
-	if (adt == IPSET_ADD) {
-		if (!ret) {
-			ret = iface_add(&h->rbtree, &e.iface);
-			if (ret)
-				return ret;
-		}
-	} else if (!ret)
-		return ret;
+	IFNAMCPY(e.iface, nla_data(tb[IPSET_ATTR_IFACE]));
 
 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
@@ -372,7 +273,7 @@ struct hash_netiface6_elem {
 	u8 cidr;
 	u8 nomatch;
 	u8 elem;
-	const char *iface;
+	char iface[IFNAMSIZ];
 };
 
 /* Common functions */
@@ -386,7 +287,7 @@ hash_netiface6_data_equal(const struct hash_netiface6_elem *ip1,
 	       ip1->cidr == ip2->cidr &&
 	       (++*multi) &&
 	       ip1->physdev == ip2->physdev &&
-	       ip1->iface == ip2->iface;
+	       STREQ(ip1->iface, ip2->iface);
 }
 
 static inline int
@@ -464,7 +365,6 @@ hash_netiface6_kadt(struct ip_set *set, const struct sk_buff *skb,
 		.elem = 1,
 	};
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
-	int ret;
 
 	if (e.cidr == 0)
 		return -EINVAL;
@@ -480,25 +380,15 @@ hash_netiface6_kadt(struct ip_set *set, const struct sk_buff *skb,
 
 		if (!nf_bridge)
 			return -EINVAL;
-		e.iface = SRCDIR ? PHYSDEV(physindev) : PHYSDEV(physoutdev);
+		IFNAMCPY(e.iface,
+			 SRCDIR ? PHYSDEV(physindev) : PHYSDEV(physoutdev));
 		e.physdev = 1;
-#else
-		e.iface = NULL;
 #endif
 	} else
-		e.iface = SRCDIR ? IFACE(in) : IFACE(out);
+		IFNAMCPY(e.iface, SRCDIR ? IFACE(in) : IFACE(out));
 
-	if (!e.iface)
+	if (strlen(e.iface) == 0)
 		return -EINVAL;
-	ret = iface_test(&h->rbtree, &e.iface);
-	if (adt == IPSET_ADD) {
-		if (!ret) {
-			ret = iface_add(&h->rbtree, &e.iface);
-			if (ret)
-				return ret;
-		}
-	} else if (!ret)
-		return ret;
 
 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
 }
@@ -507,11 +397,9 @@ static int
 hash_netiface6_uadt(struct ip_set *set, struct nlattr *tb[],
 		   enum ipset_adt adt, u32 *lineno, u32 flags, bool retried)
 {
-	struct hash_netiface *h = set->data;
 	ipset_adtfn adtfn = set->variant->adt[adt];
 	struct hash_netiface6_elem e = { .cidr = HOST_MASK, .elem = 1 };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
-	char iface[IFNAMSIZ];
 	int ret;
 
 	if (unlikely(!tb[IPSET_ATTR_IP] ||
@@ -541,17 +429,7 @@ hash_netiface6_uadt(struct ip_set *set, struct nlattr *tb[],
 		return -IPSET_ERR_INVALID_CIDR;
 	ip6_netmask(&e.ip, e.cidr);
 
-	strcpy(iface, nla_data(tb[IPSET_ATTR_IFACE]));
-	e.iface = iface;
-	ret = iface_test(&h->rbtree, &e.iface);
-	if (adt == IPSET_ADD) {
-		if (!ret) {
-			ret = iface_add(&h->rbtree, &e.iface);
-			if (ret)
-				return ret;
-		}
-	} else if (!ret)
-		return ret;
+	IFNAMCPY(e.iface, nla_data(tb[IPSET_ATTR_IFACE]));
 
 	if (tb[IPSET_ATTR_CADT_FLAGS]) {
 		u32 cadt_flags = ip_set_get_h32(tb[IPSET_ATTR_CADT_FLAGS]);
-- 
1.8.5.1