Message-Id: <20230118123208.17167-6-fw@strlen.de>
Date:   Wed, 18 Jan 2023 13:32:04 +0100
From:   Florian Westphal <fw@...len.de>
To:     <netdev@...r.kernel.org>
Cc:     Jakub Kicinski <kuba@...nel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Paolo Abeni <pabeni@...hat.com>,
        "David S. Miller" <davem@...emloft.net>,
        <netfilter-devel@...r.kernel.org>, Florian Westphal <fw@...len.de>
Subject: [PATCH net-next 5/9] netfilter: ip_tables: remove clusterip target

Marked as 'to be removed soon' since kernel 4.1 (2015).
Functionality was superseded by the 'cluster' match, added in kernel
2.6.30 (2009).

clusterip_tg_check still has races that can give

 proc_dir_entry 'ipt_CLUSTERIP/10.1.1.2' already registered

followed by a WARN splat.

Remove it instead of trying to fix this up again.
clusterip uapi header is left as-is for now.

Signed-off-by: Florian Westphal <fw@...len.de>
---
 net/ipv4/netfilter/Kconfig         |  14 -
 net/ipv4/netfilter/Makefile        |   1 -
 net/ipv4/netfilter/ipt_CLUSTERIP.c | 929 -----------------------------
 3 files changed, 944 deletions(-)
 delete mode 100644 net/ipv4/netfilter/ipt_CLUSTERIP.c

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index aab384126f61..f71a7e9a7de6 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -259,20 +259,6 @@ config IP_NF_MANGLE
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
-config IP_NF_TARGET_CLUSTERIP
-	tristate "CLUSTERIP target support"
-	depends on IP_NF_MANGLE
-	depends on NF_CONNTRACK
-	depends on NETFILTER_ADVANCED
-	select NF_CONNTRACK_MARK
-	select NETFILTER_FAMILY_ARP
-	help
-	  The CLUSTERIP target allows you to build load-balancing clusters of
-	  network servers without having a dedicated load-balancing
-	  router/server/switch.
-
-	  To compile it as a module, choose M here.  If unsure, say N.
-
 config IP_NF_TARGET_ECN
 	tristate "ECN target support"
 	depends on IP_NF_MANGLE
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index 93bad1184251..5a26f9de1ab9 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -39,7 +39,6 @@ obj-$(CONFIG_IP_NF_MATCH_AH) += ipt_ah.o
 obj-$(CONFIG_IP_NF_MATCH_RPFILTER) += ipt_rpfilter.o
 
 # targets
-obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
 obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_ECN.o
 obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
 obj-$(CONFIG_IP_NF_TARGET_SYNPROXY) += ipt_SYNPROXY.o
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
deleted file mode 100644
index b3cc416ed292..000000000000
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ /dev/null
@@ -1,929 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/* Cluster IP hashmark target
- * (C) 2003-2004 by Harald Welte <laforge@...filter.org>
- * based on ideas of Fabio Olive Leite <olive@...xforge.org>
- *
- * Development of this code funded by SuSE Linux AG, https://www.suse.com/
- */
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/module.h>
-#include <linux/proc_fs.h>
-#include <linux/jhash.h>
-#include <linux/bitops.h>
-#include <linux/skbuff.h>
-#include <linux/slab.h>
-#include <linux/ip.h>
-#include <linux/tcp.h>
-#include <linux/udp.h>
-#include <linux/icmp.h>
-#include <linux/if_arp.h>
-#include <linux/seq_file.h>
-#include <linux/refcount.h>
-#include <linux/netfilter_arp.h>
-#include <linux/netfilter/x_tables.h>
-#include <linux/netfilter_ipv4/ip_tables.h>
-#include <linux/netfilter_ipv4/ipt_CLUSTERIP.h>
-#include <net/netfilter/nf_conntrack.h>
-#include <net/net_namespace.h>
-#include <net/netns/generic.h>
-#include <net/checksum.h>
-#include <net/ip.h>
-
-#define CLUSTERIP_VERSION "0.8"
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Harald Welte <laforge@...filter.org>");
-MODULE_DESCRIPTION("Xtables: CLUSTERIP target");
-
-struct clusterip_config {
-	struct list_head list;			/* list of all configs */
-	refcount_t refcount;			/* reference count */
-	refcount_t entries;			/* number of entries/rules
-						 * referencing us */
-
-	__be32 clusterip;			/* the IP address */
-	u_int8_t clustermac[ETH_ALEN];		/* the MAC address */
-	int ifindex;				/* device ifindex */
-	u_int16_t num_total_nodes;		/* total number of nodes */
-	unsigned long local_nodes;		/* node number array */
-
-#ifdef CONFIG_PROC_FS
-	struct proc_dir_entry *pde;		/* proc dir entry */
-#endif
-	enum clusterip_hashmode hash_mode;	/* which hashing mode */
-	u_int32_t hash_initval;			/* hash initialization */
-	struct rcu_head rcu;			/* for call_rcu */
-	struct net *net;			/* netns for pernet list */
-	char ifname[IFNAMSIZ];			/* device ifname */
-};
-
-#ifdef CONFIG_PROC_FS
-static const struct proc_ops clusterip_proc_ops;
-#endif
-
-struct clusterip_net {
-	struct list_head configs;
-	/* lock protects the configs list */
-	spinlock_t lock;
-
-	bool clusterip_deprecated_warning;
-#ifdef CONFIG_PROC_FS
-	struct proc_dir_entry *procdir;
-	/* mutex protects the config->pde*/
-	struct mutex mutex;
-#endif
-	unsigned int hook_users;
-};
-
-static unsigned int clusterip_arp_mangle(void *priv, struct sk_buff *skb, const struct nf_hook_state *state);
-
-static const struct nf_hook_ops cip_arp_ops = {
-	.hook = clusterip_arp_mangle,
-	.pf = NFPROTO_ARP,
-	.hooknum = NF_ARP_OUT,
-	.priority = -1
-};
-
-static unsigned int clusterip_net_id __read_mostly;
-static inline struct clusterip_net *clusterip_pernet(struct net *net)
-{
-	return net_generic(net, clusterip_net_id);
-}
-
-static inline void
-clusterip_config_get(struct clusterip_config *c)
-{
-	refcount_inc(&c->refcount);
-}
-
-static void clusterip_config_rcu_free(struct rcu_head *head)
-{
-	struct clusterip_config *config;
-	struct net_device *dev;
-
-	config = container_of(head, struct clusterip_config, rcu);
-	dev = dev_get_by_name(config->net, config->ifname);
-	if (dev) {
-		dev_mc_del(dev, config->clustermac);
-		dev_put(dev);
-	}
-	kfree(config);
-}
-
-static inline void
-clusterip_config_put(struct clusterip_config *c)
-{
-	if (refcount_dec_and_test(&c->refcount))
-		call_rcu(&c->rcu, clusterip_config_rcu_free);
-}
-
-/* decrease the count of entries using/referencing this config.  If last
- * entry(rule) is removed, remove the config from lists, but don't free it
- * yet, since proc-files could still be holding references */
-static inline void
-clusterip_config_entry_put(struct clusterip_config *c)
-{
-	struct clusterip_net *cn = clusterip_pernet(c->net);
-
-	local_bh_disable();
-	if (refcount_dec_and_lock(&c->entries, &cn->lock)) {
-		list_del_rcu(&c->list);
-		spin_unlock(&cn->lock);
-		local_bh_enable();
-		/* In case anyone still accesses the file, the open/close
-		 * functions are also incrementing the refcount on their own,
-		 * so it's safe to remove the entry even if it's in use. */
-#ifdef CONFIG_PROC_FS
-		mutex_lock(&cn->mutex);
-		if (cn->procdir)
-			proc_remove(c->pde);
-		mutex_unlock(&cn->mutex);
-#endif
-		return;
-	}
-	local_bh_enable();
-}
-
-static struct clusterip_config *
-__clusterip_config_find(struct net *net, __be32 clusterip)
-{
-	struct clusterip_config *c;
-	struct clusterip_net *cn = clusterip_pernet(net);
-
-	list_for_each_entry_rcu(c, &cn->configs, list) {
-		if (c->clusterip == clusterip)
-			return c;
-	}
-
-	return NULL;
-}
-
-static inline struct clusterip_config *
-clusterip_config_find_get(struct net *net, __be32 clusterip, int entry)
-{
-	struct clusterip_config *c;
-
-	rcu_read_lock_bh();
-	c = __clusterip_config_find(net, clusterip);
-	if (c) {
-#ifdef CONFIG_PROC_FS
-		if (!c->pde)
-			c = NULL;
-		else
-#endif
-		if (unlikely(!refcount_inc_not_zero(&c->refcount)))
-			c = NULL;
-		else if (entry) {
-			if (unlikely(!refcount_inc_not_zero(&c->entries))) {
-				clusterip_config_put(c);
-				c = NULL;
-			}
-		}
-	}
-	rcu_read_unlock_bh();
-
-	return c;
-}
-
-static void
-clusterip_config_init_nodelist(struct clusterip_config *c,
-			       const struct ipt_clusterip_tgt_info *i)
-{
-	int n;
-
-	for (n = 0; n < i->num_local_nodes; n++)
-		set_bit(i->local_nodes[n] - 1, &c->local_nodes);
-}
-
-static int
-clusterip_netdev_event(struct notifier_block *this, unsigned long event,
-		       void *ptr)
-{
-	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-	struct net *net = dev_net(dev);
-	struct clusterip_net *cn = clusterip_pernet(net);
-	struct clusterip_config *c;
-
-	spin_lock_bh(&cn->lock);
-	list_for_each_entry_rcu(c, &cn->configs, list) {
-		switch (event) {
-		case NETDEV_REGISTER:
-			if (!strcmp(dev->name, c->ifname)) {
-				c->ifindex = dev->ifindex;
-				dev_mc_add(dev, c->clustermac);
-			}
-			break;
-		case NETDEV_UNREGISTER:
-			if (dev->ifindex == c->ifindex) {
-				dev_mc_del(dev, c->clustermac);
-				c->ifindex = -1;
-			}
-			break;
-		case NETDEV_CHANGENAME:
-			if (!strcmp(dev->name, c->ifname)) {
-				c->ifindex = dev->ifindex;
-				dev_mc_add(dev, c->clustermac);
-			} else if (dev->ifindex == c->ifindex) {
-				dev_mc_del(dev, c->clustermac);
-				c->ifindex = -1;
-			}
-			break;
-		}
-	}
-	spin_unlock_bh(&cn->lock);
-
-	return NOTIFY_DONE;
-}
-
-static struct clusterip_config *
-clusterip_config_init(struct net *net, const struct ipt_clusterip_tgt_info *i,
-		      __be32 ip, const char *iniface)
-{
-	struct clusterip_net *cn = clusterip_pernet(net);
-	struct clusterip_config *c;
-	struct net_device *dev;
-	int err;
-
-	if (iniface[0] == '\0') {
-		pr_info("Please specify an interface name\n");
-		return ERR_PTR(-EINVAL);
-	}
-
-	c = kzalloc(sizeof(*c), GFP_ATOMIC);
-	if (!c)
-		return ERR_PTR(-ENOMEM);
-
-	dev = dev_get_by_name(net, iniface);
-	if (!dev) {
-		pr_info("no such interface %s\n", iniface);
-		kfree(c);
-		return ERR_PTR(-ENOENT);
-	}
-	c->ifindex = dev->ifindex;
-	strcpy(c->ifname, dev->name);
-	memcpy(&c->clustermac, &i->clustermac, ETH_ALEN);
-	dev_mc_add(dev, c->clustermac);
-	dev_put(dev);
-
-	c->clusterip = ip;
-	c->num_total_nodes = i->num_total_nodes;
-	clusterip_config_init_nodelist(c, i);
-	c->hash_mode = i->hash_mode;
-	c->hash_initval = i->hash_initval;
-	c->net = net;
-	refcount_set(&c->refcount, 1);
-
-	spin_lock_bh(&cn->lock);
-	if (__clusterip_config_find(net, ip)) {
-		err = -EBUSY;
-		goto out_config_put;
-	}
-
-	list_add_rcu(&c->list, &cn->configs);
-	spin_unlock_bh(&cn->lock);
-
-#ifdef CONFIG_PROC_FS
-	{
-		char buffer[16];
-
-		/* create proc dir entry */
-		sprintf(buffer, "%pI4", &ip);
-		mutex_lock(&cn->mutex);
-		c->pde = proc_create_data(buffer, 0600,
-					  cn->procdir,
-					  &clusterip_proc_ops, c);
-		mutex_unlock(&cn->mutex);
-		if (!c->pde) {
-			err = -ENOMEM;
-			goto err;
-		}
-	}
-#endif
-
-	refcount_set(&c->entries, 1);
-	return c;
-
-#ifdef CONFIG_PROC_FS
-err:
-#endif
-	spin_lock_bh(&cn->lock);
-	list_del_rcu(&c->list);
-out_config_put:
-	spin_unlock_bh(&cn->lock);
-	clusterip_config_put(c);
-	return ERR_PTR(err);
-}
-
-#ifdef CONFIG_PROC_FS
-static int
-clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum)
-{
-
-	if (nodenum == 0 ||
-	    nodenum > c->num_total_nodes)
-		return 1;
-
-	/* check if we already have this number in our bitfield */
-	if (test_and_set_bit(nodenum - 1, &c->local_nodes))
-		return 1;
-
-	return 0;
-}
-
-static bool
-clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum)
-{
-	if (nodenum == 0 ||
-	    nodenum > c->num_total_nodes)
-		return true;
-
-	if (test_and_clear_bit(nodenum - 1, &c->local_nodes))
-		return false;
-
-	return true;
-}
-#endif
-
-static inline u_int32_t
-clusterip_hashfn(const struct sk_buff *skb,
-		 const struct clusterip_config *config)
-{
-	const struct iphdr *iph = ip_hdr(skb);
-	unsigned long hashval;
-	u_int16_t sport = 0, dport = 0;
-	int poff;
-
-	poff = proto_ports_offset(iph->protocol);
-	if (poff >= 0) {
-		const u_int16_t *ports;
-		u16 _ports[2];
-
-		ports = skb_header_pointer(skb, iph->ihl * 4 + poff, 4, _ports);
-		if (ports) {
-			sport = ports[0];
-			dport = ports[1];
-		}
-	} else {
-		net_info_ratelimited("unknown protocol %u\n", iph->protocol);
-	}
-
-	switch (config->hash_mode) {
-	case CLUSTERIP_HASHMODE_SIP:
-		hashval = jhash_1word(ntohl(iph->saddr),
-				      config->hash_initval);
-		break;
-	case CLUSTERIP_HASHMODE_SIP_SPT:
-		hashval = jhash_2words(ntohl(iph->saddr), sport,
-				       config->hash_initval);
-		break;
-	case CLUSTERIP_HASHMODE_SIP_SPT_DPT:
-		hashval = jhash_3words(ntohl(iph->saddr), sport, dport,
-				       config->hash_initval);
-		break;
-	default:
-		/* to make gcc happy */
-		hashval = 0;
-		/* This cannot happen, unless the check function wasn't called
-		 * at rule load time */
-		pr_info("unknown mode %u\n", config->hash_mode);
-		BUG();
-		break;
-	}
-
-	/* node numbers are 1..n, not 0..n */
-	return reciprocal_scale(hashval, config->num_total_nodes) + 1;
-}
-
-static inline int
-clusterip_responsible(const struct clusterip_config *config, u_int32_t hash)
-{
-	return test_bit(hash - 1, &config->local_nodes);
-}
-
-/***********************************************************************
- * IPTABLES TARGET
- ***********************************************************************/
-
-static unsigned int
-clusterip_tg(struct sk_buff *skb, const struct xt_action_param *par)
-{
-	const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
-	struct nf_conn *ct;
-	enum ip_conntrack_info ctinfo;
-	u_int32_t hash;
-
-	/* don't need to clusterip_config_get() here, since refcount
-	 * is only decremented by destroy() - and ip_tables guarantees
-	 * that the ->target() function isn't called after ->destroy() */
-
-	ct = nf_ct_get(skb, &ctinfo);
-	if (ct == NULL)
-		return NF_DROP;
-
-	/* special case: ICMP error handling. conntrack distinguishes between
-	 * error messages (RELATED) and information requests (see below) */
-	if (ip_hdr(skb)->protocol == IPPROTO_ICMP &&
-	    (ctinfo == IP_CT_RELATED ||
-	     ctinfo == IP_CT_RELATED_REPLY))
-		return XT_CONTINUE;
-
-	/* nf_conntrack_proto_icmp guarantees us that we only have ICMP_ECHO,
-	 * TIMESTAMP, INFO_REQUEST or ICMP_ADDRESS type icmp packets from here
-	 * on, which all have an ID field [relevant for hashing]. */
-
-	hash = clusterip_hashfn(skb, cipinfo->config);
-
-	switch (ctinfo) {
-	case IP_CT_NEW:
-		WRITE_ONCE(ct->mark, hash);
-		break;
-	case IP_CT_RELATED:
-	case IP_CT_RELATED_REPLY:
-		/* FIXME: we don't handle expectations at the moment.
-		 * They can arrive on a different node than
-		 * the master connection (e.g. FTP passive mode) */
-	case IP_CT_ESTABLISHED:
-	case IP_CT_ESTABLISHED_REPLY:
-		break;
-	default:			/* Prevent gcc warnings */
-		break;
-	}
-
-#ifdef DEBUG
-	nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
-#endif
-	pr_debug("hash=%u ct_hash=%u ", hash, READ_ONCE(ct->mark));
-	if (!clusterip_responsible(cipinfo->config, hash)) {
-		pr_debug("not responsible\n");
-		return NF_DROP;
-	}
-	pr_debug("responsible\n");
-
-	/* despite being received via linklayer multicast, this is
-	 * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */
-	skb->pkt_type = PACKET_HOST;
-
-	return XT_CONTINUE;
-}
-
-static int clusterip_tg_check(const struct xt_tgchk_param *par)
-{
-	struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
-	struct clusterip_net *cn = clusterip_pernet(par->net);
-	const struct ipt_entry *e = par->entryinfo;
-	struct clusterip_config *config;
-	int ret, i;
-
-	if (par->nft_compat) {
-		pr_err("cannot use CLUSTERIP target from nftables compat\n");
-		return -EOPNOTSUPP;
-	}
-
-	if (cn->hook_users == UINT_MAX)
-		return -EOVERFLOW;
-
-	if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP &&
-	    cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT &&
-	    cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) {
-		pr_info("unknown mode %u\n", cipinfo->hash_mode);
-		return -EINVAL;
-
-	}
-	if (e->ip.dmsk.s_addr != htonl(0xffffffff) ||
-	    e->ip.dst.s_addr == 0) {
-		pr_info("Please specify destination IP\n");
-		return -EINVAL;
-	}
-	if (cipinfo->num_local_nodes > ARRAY_SIZE(cipinfo->local_nodes)) {
-		pr_info("bad num_local_nodes %u\n", cipinfo->num_local_nodes);
-		return -EINVAL;
-	}
-	for (i = 0; i < cipinfo->num_local_nodes; i++) {
-		if (cipinfo->local_nodes[i] - 1 >=
-		    sizeof(config->local_nodes) * 8) {
-			pr_info("bad local_nodes[%d] %u\n",
-				i, cipinfo->local_nodes[i]);
-			return -EINVAL;
-		}
-	}
-
-	config = clusterip_config_find_get(par->net, e->ip.dst.s_addr, 1);
-	if (!config) {
-		if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
-			pr_info("no config found for %pI4, need 'new'\n",
-				&e->ip.dst.s_addr);
-			return -EINVAL;
-		} else {
-			config = clusterip_config_init(par->net, cipinfo,
-						       e->ip.dst.s_addr,
-						       e->ip.iniface);
-			if (IS_ERR(config))
-				return PTR_ERR(config);
-		}
-	} else if (memcmp(&config->clustermac, &cipinfo->clustermac, ETH_ALEN)) {
-		clusterip_config_entry_put(config);
-		clusterip_config_put(config);
-		return -EINVAL;
-	}
-
-	ret = nf_ct_netns_get(par->net, par->family);
-	if (ret < 0) {
-		pr_info("cannot load conntrack support for proto=%u\n",
-			par->family);
-		clusterip_config_entry_put(config);
-		clusterip_config_put(config);
-		return ret;
-	}
-
-	if (cn->hook_users == 0) {
-		ret = nf_register_net_hook(par->net, &cip_arp_ops);
-
-		if (ret < 0) {
-			clusterip_config_entry_put(config);
-			clusterip_config_put(config);
-			nf_ct_netns_put(par->net, par->family);
-			return ret;
-		}
-	}
-
-	cn->hook_users++;
-
-	if (!cn->clusterip_deprecated_warning) {
-		pr_info("ipt_CLUSTERIP is deprecated and it will removed soon, "
-			"use xt_cluster instead\n");
-		cn->clusterip_deprecated_warning = true;
-	}
-
-	cipinfo->config = config;
-	return ret;
-}
-
-/* drop reference count of cluster config when rule is deleted */
-static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
-{
-	const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
-	struct clusterip_net *cn = clusterip_pernet(par->net);
-
-	/* if no more entries are referencing the config, remove it
-	 * from the list and destroy the proc entry */
-	clusterip_config_entry_put(cipinfo->config);
-
-	clusterip_config_put(cipinfo->config);
-
-	nf_ct_netns_put(par->net, par->family);
-	cn->hook_users--;
-
-	if (cn->hook_users == 0)
-		nf_unregister_net_hook(par->net, &cip_arp_ops);
-}
-
-#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
-struct compat_ipt_clusterip_tgt_info
-{
-	u_int32_t	flags;
-	u_int8_t	clustermac[6];
-	u_int16_t	num_total_nodes;
-	u_int16_t	num_local_nodes;
-	u_int16_t	local_nodes[CLUSTERIP_MAX_NODES];
-	u_int32_t	hash_mode;
-	u_int32_t	hash_initval;
-	compat_uptr_t	config;
-};
-#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
-
-static struct xt_target clusterip_tg_reg __read_mostly = {
-	.name		= "CLUSTERIP",
-	.family		= NFPROTO_IPV4,
-	.target		= clusterip_tg,
-	.checkentry	= clusterip_tg_check,
-	.destroy	= clusterip_tg_destroy,
-	.targetsize	= sizeof(struct ipt_clusterip_tgt_info),
-	.usersize	= offsetof(struct ipt_clusterip_tgt_info, config),
-#ifdef CONFIG_NETFILTER_XTABLES_COMPAT
-	.compatsize	= sizeof(struct compat_ipt_clusterip_tgt_info),
-#endif /* CONFIG_NETFILTER_XTABLES_COMPAT */
-	.me		= THIS_MODULE
-};
-
-
-/***********************************************************************
- * ARP MANGLING CODE
- ***********************************************************************/
-
-/* hardcoded for 48bit ethernet and 32bit ipv4 addresses */
-struct arp_payload {
-	u_int8_t src_hw[ETH_ALEN];
-	__be32 src_ip;
-	u_int8_t dst_hw[ETH_ALEN];
-	__be32 dst_ip;
-} __packed;
-
-#ifdef DEBUG
-static void arp_print(struct arp_payload *payload)
-{
-#define HBUFFERLEN 30
-	char hbuffer[HBUFFERLEN];
-	int j, k;
-
-	for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < ETH_ALEN; j++) {
-		hbuffer[k++] = hex_asc_hi(payload->src_hw[j]);
-		hbuffer[k++] = hex_asc_lo(payload->src_hw[j]);
-		hbuffer[k++] = ':';
-	}
-	hbuffer[--k] = '\0';
-
-	pr_debug("src %pI4@%s, dst %pI4\n",
-		 &payload->src_ip, hbuffer, &payload->dst_ip);
-}
-#endif
-
-static unsigned int
-clusterip_arp_mangle(void *priv, struct sk_buff *skb,
-		     const struct nf_hook_state *state)
-{
-	struct arphdr *arp = arp_hdr(skb);
-	struct arp_payload *payload;
-	struct clusterip_config *c;
-	struct net *net = state->net;
-
-	/* we don't care about non-ethernet and non-ipv4 ARP */
-	if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
-	    arp->ar_pro != htons(ETH_P_IP) ||
-	    arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN)
-		return NF_ACCEPT;
-
-	/* we only want to mangle arp requests and replies */
-	if (arp->ar_op != htons(ARPOP_REPLY) &&
-	    arp->ar_op != htons(ARPOP_REQUEST))
-		return NF_ACCEPT;
-
-	payload = (void *)(arp+1);
-
-	/* if there is no clusterip configuration for the arp reply's
-	 * source ip, we don't want to mangle it */
-	c = clusterip_config_find_get(net, payload->src_ip, 0);
-	if (!c)
-		return NF_ACCEPT;
-
-	/* normally the linux kernel always replies to arp queries of
-	 * addresses on different interfacs.  However, in the CLUSTERIP case
-	 * this wouldn't work, since we didn't subscribe the mcast group on
-	 * other interfaces */
-	if (c->ifindex != state->out->ifindex) {
-		pr_debug("not mangling arp reply on different interface: cip'%d'-skb'%d'\n",
-			 c->ifindex, state->out->ifindex);
-		clusterip_config_put(c);
-		return NF_ACCEPT;
-	}
-
-	/* mangle reply hardware address */
-	memcpy(payload->src_hw, c->clustermac, arp->ar_hln);
-
-#ifdef DEBUG
-	pr_debug("mangled arp reply: ");
-	arp_print(payload);
-#endif
-
-	clusterip_config_put(c);
-
-	return NF_ACCEPT;
-}
-
-/***********************************************************************
- * PROC DIR HANDLING
- ***********************************************************************/
-
-#ifdef CONFIG_PROC_FS
-
-struct clusterip_seq_position {
-	unsigned int pos;	/* position */
-	unsigned int weight;	/* number of bits set == size */
-	unsigned int bit;	/* current bit */
-	unsigned long val;	/* current value */
-};
-
-static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
-{
-	struct clusterip_config *c = s->private;
-	unsigned int weight;
-	u_int32_t local_nodes;
-	struct clusterip_seq_position *idx;
-
-	/* FIXME: possible race */
-	local_nodes = c->local_nodes;
-	weight = hweight32(local_nodes);
-	if (*pos >= weight)
-		return NULL;
-
-	idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL);
-	if (!idx)
-		return ERR_PTR(-ENOMEM);
-
-	idx->pos = *pos;
-	idx->weight = weight;
-	idx->bit = ffs(local_nodes);
-	idx->val = local_nodes;
-	clear_bit(idx->bit - 1, &idx->val);
-
-	return idx;
-}
-
-static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
-{
-	struct clusterip_seq_position *idx = v;
-
-	*pos = ++idx->pos;
-	if (*pos >= idx->weight) {
-		kfree(v);
-		return NULL;
-	}
-	idx->bit = ffs(idx->val);
-	clear_bit(idx->bit - 1, &idx->val);
-	return idx;
-}
-
-static void clusterip_seq_stop(struct seq_file *s, void *v)
-{
-	if (!IS_ERR(v))
-		kfree(v);
-}
-
-static int clusterip_seq_show(struct seq_file *s, void *v)
-{
-	struct clusterip_seq_position *idx = v;
-
-	if (idx->pos != 0)
-		seq_putc(s, ',');
-
-	seq_printf(s, "%u", idx->bit);
-
-	if (idx->pos == idx->weight - 1)
-		seq_putc(s, '\n');
-
-	return 0;
-}
-
-static const struct seq_operations clusterip_seq_ops = {
-	.start	= clusterip_seq_start,
-	.next	= clusterip_seq_next,
-	.stop	= clusterip_seq_stop,
-	.show	= clusterip_seq_show,
-};
-
-static int clusterip_proc_open(struct inode *inode, struct file *file)
-{
-	int ret = seq_open(file, &clusterip_seq_ops);
-
-	if (!ret) {
-		struct seq_file *sf = file->private_data;
-		struct clusterip_config *c = pde_data(inode);
-
-		sf->private = c;
-
-		clusterip_config_get(c);
-	}
-
-	return ret;
-}
-
-static int clusterip_proc_release(struct inode *inode, struct file *file)
-{
-	struct clusterip_config *c = pde_data(inode);
-	int ret;
-
-	ret = seq_release(inode, file);
-
-	if (!ret)
-		clusterip_config_put(c);
-
-	return ret;
-}
-
-static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
-				size_t size, loff_t *ofs)
-{
-	struct clusterip_config *c = pde_data(file_inode(file));
-#define PROC_WRITELEN	10
-	char buffer[PROC_WRITELEN+1];
-	unsigned long nodenum;
-	int rc;
-
-	if (size > PROC_WRITELEN)
-		return -EIO;
-	if (copy_from_user(buffer, input, size))
-		return -EFAULT;
-	buffer[size] = 0;
-
-	if (*buffer == '+') {
-		rc = kstrtoul(buffer+1, 10, &nodenum);
-		if (rc)
-			return rc;
-		if (clusterip_add_node(c, nodenum))
-			return -ENOMEM;
-	} else if (*buffer == '-') {
-		rc = kstrtoul(buffer+1, 10, &nodenum);
-		if (rc)
-			return rc;
-		if (clusterip_del_node(c, nodenum))
-			return -ENOENT;
-	} else
-		return -EIO;
-
-	return size;
-}
-
-static const struct proc_ops clusterip_proc_ops = {
-	.proc_open	= clusterip_proc_open,
-	.proc_read	= seq_read,
-	.proc_write	= clusterip_proc_write,
-	.proc_lseek	= seq_lseek,
-	.proc_release	= clusterip_proc_release,
-};
-
-#endif /* CONFIG_PROC_FS */
-
-static int clusterip_net_init(struct net *net)
-{
-	struct clusterip_net *cn = clusterip_pernet(net);
-
-	INIT_LIST_HEAD(&cn->configs);
-
-	spin_lock_init(&cn->lock);
-
-#ifdef CONFIG_PROC_FS
-	cn->procdir = proc_mkdir("ipt_CLUSTERIP", net->proc_net);
-	if (!cn->procdir) {
-		pr_err("Unable to proc dir entry\n");
-		return -ENOMEM;
-	}
-	mutex_init(&cn->mutex);
-#endif /* CONFIG_PROC_FS */
-
-	return 0;
-}
-
-static void clusterip_net_exit(struct net *net)
-{
-#ifdef CONFIG_PROC_FS
-	struct clusterip_net *cn = clusterip_pernet(net);
-
-	mutex_lock(&cn->mutex);
-	proc_remove(cn->procdir);
-	cn->procdir = NULL;
-	mutex_unlock(&cn->mutex);
-#endif
-}
-
-static struct pernet_operations clusterip_net_ops = {
-	.init = clusterip_net_init,
-	.exit = clusterip_net_exit,
-	.id   = &clusterip_net_id,
-	.size = sizeof(struct clusterip_net),
-};
-
-static struct notifier_block cip_netdev_notifier = {
-	.notifier_call = clusterip_netdev_event
-};
-
-static int __init clusterip_tg_init(void)
-{
-	int ret;
-
-	ret = register_pernet_subsys(&clusterip_net_ops);
-	if (ret < 0)
-		return ret;
-
-	ret = xt_register_target(&clusterip_tg_reg);
-	if (ret < 0)
-		goto cleanup_subsys;
-
-	ret = register_netdevice_notifier(&cip_netdev_notifier);
-	if (ret < 0)
-		goto unregister_target;
-
-	pr_info("ClusterIP Version %s loaded successfully\n",
-		CLUSTERIP_VERSION);
-
-	return 0;
-
-unregister_target:
-	xt_unregister_target(&clusterip_tg_reg);
-cleanup_subsys:
-	unregister_pernet_subsys(&clusterip_net_ops);
-	return ret;
-}
-
-static void __exit clusterip_tg_exit(void)
-{
-	pr_info("ClusterIP Version %s unloading\n", CLUSTERIP_VERSION);
-
-	unregister_netdevice_notifier(&cip_netdev_notifier);
-	xt_unregister_target(&clusterip_tg_reg);
-	unregister_pernet_subsys(&clusterip_net_ops);
-
-	/* Wait for completion of call_rcu()'s (clusterip_config_rcu_free) */
-	rcu_barrier();
-}
-
-module_init(clusterip_tg_init);
-module_exit(clusterip_tg_exit);
-- 
2.38.2

Powered by blists - more mailing lists