debug lk

hc

2024-02-20 e636c8d336489bf3eed5878299e6cc045bbad077

 kernel/net/ipv6/anycast.c
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@@ -1,3 +1,4 @@
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+// SPDX-License-Identifier: GPL-2.0-or-later
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 /*
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  *	Anycast support for IPv6
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  *	Linux INET6 implementation
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@@ -6,11 +7,6 @@
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  *	David L Stevens (dlstevens@us.ibm.com)
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  *
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  *	based heavily on net/ipv6/mcast.c
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- *
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- *	This program is free software; you can redistribute it and/or
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- *      modify it under the terms of the GNU General Public License
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- *      as published by the Free Software Foundation; either version
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- *      2 of the License, or (at your option) any later version.
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  */
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11
 
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 #include <linux/capability.h>
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@@ -44,7 +40,21 @@
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40
 
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 #include <net/checksum.h>
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42
 
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+#define IN6_ADDR_HSIZE_SHIFT	8
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+#define IN6_ADDR_HSIZE		BIT(IN6_ADDR_HSIZE_SHIFT)
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+/*	anycast address hash table
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+ */
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+static struct hlist_head inet6_acaddr_lst[IN6_ADDR_HSIZE];
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+static DEFINE_SPINLOCK(acaddr_hash_lock);
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+
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 static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);
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+
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+static u32 inet6_acaddr_hash(struct net *net, const struct in6_addr *addr)
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+{
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+	u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net);
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+
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+	return hash_32(val, IN6_ADDR_HSIZE_SHIFT);
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+}
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58
 
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 /*
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  *	socket join an anycast group
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@@ -211,16 +221,39 @@
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 	rtnl_unlock();
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 }
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+static void ipv6_add_acaddr_hash(struct net *net, struct ifacaddr6 *aca)
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+{
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+	unsigned int hash = inet6_acaddr_hash(net, &aca->aca_addr);
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+
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+	spin_lock(&acaddr_hash_lock);
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+	hlist_add_head_rcu(&aca->aca_addr_lst, &inet6_acaddr_lst[hash]);
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+	spin_unlock(&acaddr_hash_lock);
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+}
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+
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+static void ipv6_del_acaddr_hash(struct ifacaddr6 *aca)
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+{
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+	spin_lock(&acaddr_hash_lock);
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+	hlist_del_init_rcu(&aca->aca_addr_lst);
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+	spin_unlock(&acaddr_hash_lock);
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+}
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+
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 static void aca_get(struct ifacaddr6 *aca)
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 {
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 	refcount_inc(&aca->aca_refcnt);
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 }
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244
 
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+static void aca_free_rcu(struct rcu_head *h)
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+{
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+	struct ifacaddr6 *aca = container_of(h, struct ifacaddr6, rcu);
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+
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+	fib6_info_release(aca->aca_rt);
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+	kfree(aca);
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+}
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+
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 static void aca_put(struct ifacaddr6 *ac)
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 {
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 	if (refcount_dec_and_test(&ac->aca_refcnt)) {
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-		fib6_info_release(ac->aca_rt);
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-		kfree(ac);
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+		call_rcu(&ac->rcu, aca_free_rcu);
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 	}
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 }
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@@ -236,6 +269,7 @@
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 	aca->aca_addr = *addr;
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 	fib6_info_hold(f6i);
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 	aca->aca_rt = f6i;
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+	INIT_HLIST_NODE(&aca->aca_addr_lst);
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 	aca->aca_users = 1;
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 	/* aca_tstamp should be updated upon changes */
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 	aca->aca_cstamp = aca->aca_tstamp = jiffies;
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@@ -292,6 +326,8 @@
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 	aca_get(aca);
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 	write_unlock_bh(&idev->lock);
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328
 
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+	ipv6_add_acaddr_hash(net, aca);
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+
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 	ip6_ins_rt(net, f6i);
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 	addrconf_join_solict(idev->dev, &aca->aca_addr);
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@@ -332,9 +368,10 @@
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 	else
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 		idev->ac_list = aca->aca_next;
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 	write_unlock_bh(&idev->lock);
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+	ipv6_del_acaddr_hash(aca);
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 	addrconf_leave_solict(idev, &aca->aca_addr);
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-	ip6_del_rt(dev_net(idev->dev), aca->aca_rt);
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+	ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
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 	aca_put(aca);
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 	return 0;
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@@ -359,9 +396,11 @@
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 		idev->ac_list = aca->aca_next;
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 		write_unlock_bh(&idev->lock);
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+		ipv6_del_acaddr_hash(aca);
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+
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 		addrconf_leave_solict(idev, &aca->aca_addr);
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402
 
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-		ip6_del_rt(dev_net(idev->dev), aca->aca_rt);
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+		ip6_del_rt(dev_net(idev->dev), aca->aca_rt, false);
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404
 
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 		aca_put(aca);
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406
 
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@@ -397,17 +436,27 @@
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 bool ipv6_chk_acast_addr(struct net *net, struct net_device *dev,
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 			 const struct in6_addr *addr)
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 {
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+	struct net_device *nh_dev;
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+	struct ifacaddr6 *aca;
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 	bool found = false;
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 	rcu_read_lock();
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 	if (dev)
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 		found = ipv6_chk_acast_dev(dev, addr);
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-	else
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-		for_each_netdev_rcu(net, dev)
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-			if (ipv6_chk_acast_dev(dev, addr)) {
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+	else {
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+		unsigned int hash = inet6_acaddr_hash(net, addr);
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+
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+		hlist_for_each_entry_rcu(aca, &inet6_acaddr_lst[hash],
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+					 aca_addr_lst) {
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+			nh_dev = fib6_info_nh_dev(aca->aca_rt);
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+			if (!nh_dev || !net_eq(dev_net(nh_dev), net))
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+				continue;
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+			if (ipv6_addr_equal(&aca->aca_addr, addr)) {
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 				found = true;
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 				break;
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 			}
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+		}
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+	}
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 	rcu_read_unlock();
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 	return found;
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 }
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@@ -547,3 +596,24 @@
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 	remove_proc_entry("anycast6", net->proc_net);
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 }
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 #endif
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+
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+/*	Init / cleanup code
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+ */
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+int __init ipv6_anycast_init(void)
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+{
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+	int i;
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+
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+	for (i = 0; i < IN6_ADDR_HSIZE; i++)
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+		INIT_HLIST_HEAD(&inet6_acaddr_lst[i]);
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+	return 0;
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+}
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+
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+void ipv6_anycast_cleanup(void)
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+{
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+	int i;
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+
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+	spin_lock(&acaddr_hash_lock);
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+	for (i = 0; i < IN6_ADDR_HSIZE; i++)
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+		WARN_ON(!hlist_empty(&inet6_acaddr_lst[i]));
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+	spin_unlock(&acaddr_hash_lock);
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+}