Commit 11a79e83 authored by Harald Welte's avatar Harald Welte Committed by David S. Miller

[NETFILTER]: Add iptables CLUSTERIP target, seq_file version

This enables you to build a static load sharing cluster between multiple
nodes - without the requirement to have a load balancer.  It uses a
series of [evil] tricks like replying with linklayer multicast addresses
to ARP requests, and using CONNMARK for stateful blocking all traffic
not intended for the local node.
Signed-off-by: default avatarHarald Welte <laforge@netfilter.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ced208c
#ifndef _IPT_CLUSTERIP_H_target
#define _IPT_CLUSTERIP_H_target
enum clusterip_hashmode {
CLUSTERIP_HASHMODE_SIP = 0,
CLUSTERIP_HASHMODE_SIP_SPT,
CLUSTERIP_HASHMODE_SIP_SPT_DPT,
};
#define CLUSTERIP_HASHMODE_MAX CLUSTERIP_HASHMODE_SIP_SPT_DPT
#define CLUSTERIP_MAX_NODES 16
#define CLUSTERIP_FLAG_NEW 0x00000001
struct clusterip_config;
struct ipt_clusterip_tgt_info {
u_int32_t flags;
struct clusterip_config *config;
/* only relevant for new ones */
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];
enum clusterip_hashmode hash_mode;
u_int32_t hash_initval;
};
#endif /*_IPT_CLUSTERIP_H_target*/
...@@ -642,6 +642,16 @@ config IP_NF_TARGET_CONNMARK ...@@ -642,6 +642,16 @@ config IP_NF_TARGET_CONNMARK
Documentation/modules.txt. The module will be called Documentation/modules.txt. The module will be called
ipt_CONNMARK.o. If unsure, say `N'. ipt_CONNMARK.o. If unsure, say `N'.
config IP_NF_TARGET_CLUSTERIP
tristate "CLUSTERIP target support (EXPERIMENTAL)"
depends on IP_NF_CONNTRACK_MARK && IP_NF_IPTABLES && EXPERIMENTAL
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.
# raw + specific targets # raw + specific targets
config IP_NF_RAW config IP_NF_RAW
tristate 'raw table support (required for NOTRACK/TRACE)' tristate 'raw table support (required for NOTRACK/TRACE)'
......
...@@ -87,6 +87,7 @@ obj-$(CONFIG_IP_NF_TARGET_CONNMARK) += ipt_CONNMARK.o ...@@ -87,6 +87,7 @@ obj-$(CONFIG_IP_NF_TARGET_CONNMARK) += ipt_CONNMARK.o
obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o
obj-$(CONFIG_IP_NF_TARGET_TCPMSS) += ipt_TCPMSS.o obj-$(CONFIG_IP_NF_TARGET_TCPMSS) += ipt_TCPMSS.o
obj-$(CONFIG_IP_NF_TARGET_NOTRACK) += ipt_NOTRACK.o obj-$(CONFIG_IP_NF_TARGET_NOTRACK) += ipt_NOTRACK.o
obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
# generic ARP tables # generic ARP tables
obj-$(CONFIG_IP_NF_ARPTABLES) += arp_tables.o obj-$(CONFIG_IP_NF_ARPTABLES) += arp_tables.o
......
/* Cluster IP hashmark target
* (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
* based on ideas of Fabio Olive Leite <olive@unixforge.org>
*
* Development of this code funded by SuSE Linux AG, http://www.suse.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/config.h>
#include <linux/proc_fs.h>
#include <linux/jhash.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/icmp.h>
#include <linux/if_arp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <net/checksum.h>
#include <linux/netfilter_arp.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_CLUSTERIP.h>
#include <linux/netfilter_ipv4/ip_conntrack.h>
#define CLUSTERIP_VERSION "0.6"
#define DEBUG_CLUSTERIP
#ifdef DEBUG_CLUSTERIP
#define DEBUGP printk
#else
#define DEBUGP
#endif
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("iptables target for CLUSTERIP");
struct clusterip_config {
struct list_head list; /* list of all configs */
atomic_t refcount; /* reference count */
u_int32_t clusterip; /* the IP address */
u_int8_t clustermac[ETH_ALEN]; /* the MAC address */
struct net_device *dev; /* device */
u_int16_t num_total_nodes; /* total number of nodes */
u_int16_t num_local_nodes; /* number of local nodes */
u_int16_t local_nodes[CLUSTERIP_MAX_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 */
};
static LIST_HEAD(clusterip_configs);
/* clusterip_lock protects the clusterip_configs list _AND_ the configurable
* data within all structurses (num_local_nodes, local_nodes[]) */
DECLARE_RWLOCK(clusterip_lock);
#ifdef CONFIG_PROC_FS
static struct file_operations clusterip_proc_fops;
static struct proc_dir_entry *clusterip_procdir;
#endif
static inline void
clusterip_config_get(struct clusterip_config *c) {
atomic_inc(&c->refcount);
}
static inline void
clusterip_config_put(struct clusterip_config *c) {
if (atomic_dec_and_test(&c->refcount)) {
WRITE_LOCK(&clusterip_lock);
list_del(&c->list);
WRITE_UNLOCK(&clusterip_lock);
dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0);
dev_put(c->dev);
kfree(c);
}
}
static struct clusterip_config *
__clusterip_config_find(u_int32_t clusterip)
{
struct list_head *pos;
MUST_BE_READ_LOCKED(&clusterip_lock);
list_for_each(pos, &clusterip_configs) {
struct clusterip_config *c = list_entry(pos,
struct clusterip_config, list);
if (c->clusterip == clusterip) {
return c;
}
}
return NULL;
}
static inline struct clusterip_config *
clusterip_config_find_get(u_int32_t clusterip)
{
struct clusterip_config *c;
READ_LOCK(&clusterip_lock);
c = __clusterip_config_find(clusterip);
if (!c) {
READ_UNLOCK(&clusterip_lock);
return NULL;
}
atomic_inc(&c->refcount);
READ_UNLOCK(&clusterip_lock);
return c;
}
static struct clusterip_config *
clusterip_config_init(struct ipt_clusterip_tgt_info *i, u_int32_t ip,
struct net_device *dev)
{
struct clusterip_config *c;
char buffer[16];
c = kmalloc(sizeof(*c), GFP_ATOMIC);
if (!c)
return NULL;
memset(c, 0, sizeof(*c));
c->dev = dev;
c->clusterip = ip;
memcpy(&c->clustermac, &i->clustermac, ETH_ALEN);
c->num_total_nodes = i->num_total_nodes;
c->num_local_nodes = i->num_local_nodes;
memcpy(&c->local_nodes, &i->local_nodes, sizeof(&c->local_nodes));
c->hash_mode = i->hash_mode;
c->hash_initval = i->hash_initval;
atomic_set(&c->refcount, 1);
#ifdef CONFIG_PROC_FS
/* create proc dir entry */
sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip));
c->pde = create_proc_entry(buffer, S_IWUSR|S_IRUSR, clusterip_procdir);
if (!c->pde) {
kfree(c);
return NULL;
}
c->pde->proc_fops = &clusterip_proc_fops;
c->pde->data = c;
#endif
WRITE_LOCK(&clusterip_lock);
list_add(&c->list, &clusterip_configs);
WRITE_UNLOCK(&clusterip_lock);
return c;
}
static int
clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum)
{
int i;
WRITE_LOCK(&clusterip_lock);
if (c->num_local_nodes >= CLUSTERIP_MAX_NODES
|| nodenum > CLUSTERIP_MAX_NODES) {
WRITE_UNLOCK(&clusterip_lock);
return 1;
}
/* check if we alrady have this number in our array */
for (i = 0; i < c->num_local_nodes; i++) {
if (c->local_nodes[i] == nodenum) {
WRITE_UNLOCK(&clusterip_lock);
return 1;
}
}
c->local_nodes[c->num_local_nodes++] = nodenum;
WRITE_UNLOCK(&clusterip_lock);
return 0;
}
static int
clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum)
{
int i;
WRITE_LOCK(&clusterip_lock);
if (c->num_local_nodes <= 1 || nodenum > CLUSTERIP_MAX_NODES) {
WRITE_UNLOCK(&clusterip_lock);
return 1;
}
for (i = 0; i < c->num_local_nodes; i++) {
if (c->local_nodes[i] == nodenum) {
int size = sizeof(u_int16_t)*(c->num_local_nodes-(i+1));
memmove(&c->local_nodes[i], &c->local_nodes[i+1], size);
c->num_local_nodes--;
WRITE_UNLOCK(&clusterip_lock);
return 0;
}
}
WRITE_UNLOCK(&clusterip_lock);
return 1;
}
static inline u_int32_t
clusterip_hashfn(struct sk_buff *skb, struct clusterip_config *config)
{
struct iphdr *iph = skb->nh.iph;
unsigned long hashval;
u_int16_t sport, dport;
struct tcphdr *th;
struct udphdr *uh;
struct icmphdr *ih;
switch (iph->protocol) {
case IPPROTO_TCP:
th = (void *)iph+iph->ihl*4;
sport = ntohs(th->source);
dport = ntohs(th->dest);
break;
case IPPROTO_UDP:
uh = (void *)iph+iph->ihl*4;
sport = ntohs(uh->source);
dport = ntohs(uh->dest);
break;
case IPPROTO_ICMP:
ih = (void *)iph+iph->ihl*4;
sport = ntohs(ih->un.echo.id);
dport = (ih->type<<8)|ih->code;
break;
default:
if (net_ratelimit()) {
printk(KERN_NOTICE "CLUSTERIP: unknown protocol `%u'\n",
iph->protocol);
}
sport = dport = 0;
}
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 */
printk("CLUSTERIP: unknown mode `%u'\n", config->hash_mode);
BUG();
break;
}
/* node numbers are 1..n, not 0..n */
return ((hashval % config->num_total_nodes)+1);
}
static inline int
clusterip_responsible(struct clusterip_config *config, u_int32_t hash)
{
int i;
READ_LOCK(&clusterip_lock);
if (config->num_local_nodes == 0) {
READ_UNLOCK(&clusterip_lock);
return 0;
}
for (i = 0; i < config->num_local_nodes; i++) {
if (config->local_nodes[i] == hash) {
READ_UNLOCK(&clusterip_lock);
return 1;
}
}
READ_UNLOCK(&clusterip_lock);
return 0;
}
/***********************************************************************
* IPTABLES TARGET
***********************************************************************/
static unsigned int
target(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
const struct ipt_clusterip_tgt_info *cipinfo = targinfo;
enum ip_conntrack_info ctinfo;
struct ip_conntrack *ct = ip_conntrack_get((*pskb), &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() */
if (!ct) {
printk(KERN_ERR "CLUSTERIP: no conntrack!\n");
/* FIXME: need to drop invalid ones, since replies
* to outgoing connections of other nodes will be
* marked as INVALID */
return NF_DROP;
}
/* special case: ICMP error handling. conntrack distinguishes between
* error messages (RELATED) and information requests (see below) */
if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP
&& (ctinfo == IP_CT_RELATED
|| ctinfo == IP_CT_IS_REPLY+IP_CT_IS_REPLY))
return IPT_CONTINUE;
/* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO,
* TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here
* on, which all have an ID field [relevant for hashing]. */
hash = clusterip_hashfn(*pskb, cipinfo->config);
switch (ctinfo) {
case IP_CT_NEW:
ct->mark = hash;
break;
case IP_CT_RELATED:
case IP_CT_RELATED+IP_CT_IS_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+IP_CT_IS_REPLY:
break;
default:
break;
}
#ifdef DEBUG_CLUSTERP
DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
#endif
DEBUGP("hash=%u ct_hash=%lu ", hash, ct->mark);
if (!clusterip_responsible(cipinfo->config, hash)) {
DEBUGP("not responsible\n");
return NF_DROP;
}
DEBUGP("responsible\n");
/* despite being received via linklayer multicast, this is
* actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */
(*pskb)->pkt_type = PACKET_HOST;
return IPT_CONTINUE;
}
static int
checkentry(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
struct ipt_clusterip_tgt_info *cipinfo = targinfo;
struct clusterip_config *config;
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_clusterip_tgt_info))) {
printk(KERN_WARNING "CLUSTERIP: targinfosize %u != %Zu\n",
targinfosize,
IPT_ALIGN(sizeof(struct ipt_clusterip_tgt_info)));
return 0;
}
if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP &&
cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT &&
cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) {
printk(KERN_WARNING "CLUSTERIP: unknown mode `%u'\n",
cipinfo->hash_mode);
return 0;
}
if (e->ip.dmsk.s_addr != 0xffffffff
|| e->ip.dst.s_addr == 0) {
printk(KERN_ERR "CLUSTERIP: Please specify destination IP\n");
return 0;
}
/* FIXME: further sanity checks */
config = clusterip_config_find_get(e->ip.dst.s_addr);
if (!config) {
if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
printk(KERN_WARNING "CLUSTERIP: no config found for %u.%u.%u.%u, need 'new'\n", NIPQUAD(e->ip.dst.s_addr));
return 0;
} else {
struct net_device *dev;
if (e->ip.iniface[0] == '\0') {
printk(KERN_WARNING "CLUSTERIP: Please specify an interface name\n");
return 0;
}
dev = dev_get_by_name(e->ip.iniface);
if (!dev) {
printk(KERN_WARNING "CLUSTERIP: no such interface %s\n", e->ip.iniface);
return 0;
}
config = clusterip_config_init(cipinfo,
e->ip.dst.s_addr, dev);
if (!config) {
printk(KERN_WARNING "CLUSTERIP: cannot allocate config\n");
dev_put(dev);
return 0;
}
dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0);
}
}
cipinfo->config = config;
return 1;
}
/* drop reference count of cluster config when rule is deleted */
static void destroy(void *matchinfo, unsigned int matchinfosize)
{
struct ipt_clusterip_tgt_info *cipinfo = matchinfo;
/* we first remove the proc entry and then drop the reference
* count. In case anyone still accesses the file, the open/close
* functions are also incrementing the refcount on their own */
#ifdef CONFIG_PROC_FS
remove_proc_entry(cipinfo->config->pde->name,
cipinfo->config->pde->parent);
#endif
clusterip_config_put(cipinfo->config);
}
static struct ipt_target clusterip_tgt = {
.name = "CLUSTERIP",
.target = &target,
.checkentry = &checkentry,
.destroy = &destroy,
.me = THIS_MODULE
};
/***********************************************************************
* ARP MANGLING CODE
***********************************************************************/
/* hardcoded for 48bit ethernet and 32bit ipv4 addresses */
struct arp_payload {
u_int8_t src_hw[ETH_ALEN];
u_int32_t src_ip;
u_int8_t dst_hw[ETH_ALEN];
u_int32_t dst_ip;
} __attribute__ ((packed));
#ifdef CLUSTERIP_DEBUG
static void arp_print(struct arp_payload *payload)
{
#define HBUFFERLEN 30
char hbuffer[HBUFFERLEN];
int j,k;
const char hexbuf[]= "0123456789abcdef";
for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) {
hbuffer[k++]=hexbuf[(payload->src_hw[j]>>4)&15];
hbuffer[k++]=hexbuf[payload->src_hw[j]&15];
hbuffer[k++]=':';
}
hbuffer[--k]='\0';
printk("src %u.%u.%u.%u@%s, dst %u.%u.%u.%u\n",
NIPQUAD(payload->src_ip), hbuffer,
NIPQUAD(payload->dst_ip));
}
#endif
static unsigned int
arp_mangle(unsigned int hook,
struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
struct arphdr *arp = (*pskb)->nh.arph;
struct arp_payload *payload;
struct clusterip_config *c;
/* 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 replies */
if (arp->ar_op != htons(ARPOP_REPLY))
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(payload->src_ip);
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->dev != out) {
DEBUGP("CLUSTERIP: not mangling arp reply on different "
"interface: cip'%s'-skb'%s'\n", c->dev->name, out->name);
clusterip_config_put(c);
return NF_ACCEPT;
}
/* mangle reply hardware address */
memcpy(payload->src_hw, c->clustermac, arp->ar_hln);
#ifdef CLUSTERIP_DEBUG
DEBUGP(KERN_DEBUG "CLUSTERIP mangled arp reply: ");
arp_print(payload);
#endif
clusterip_config_put(c);
return NF_ACCEPT;
}
static struct nf_hook_ops cip_arp_ops = {
.hook = arp_mangle,
.pf = NF_ARP,
.hooknum = NF_ARP_OUT,
.priority = -1
};
/***********************************************************************
* PROC DIR HANDLING
***********************************************************************/
#ifdef CONFIG_PROC_FS
static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
{
struct proc_dir_entry *pde = s->private;
struct clusterip_config *c = pde->data;
unsigned int *nodeidx;
READ_LOCK(&clusterip_lock);
if (*pos >= c->num_local_nodes)
return NULL;
nodeidx = kmalloc(sizeof(unsigned int), GFP_KERNEL);
if (!nodeidx)
return ERR_PTR(-ENOMEM);
*nodeidx = *pos;
return nodeidx;
}
static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct proc_dir_entry *pde = s->private;
struct clusterip_config *c = pde->data;
unsigned int *nodeidx = (unsigned int *)v;
*pos = ++(*nodeidx);
if (*pos >= c->num_local_nodes) {
kfree(v);
return NULL;
}
return nodeidx;
}
static void clusterip_seq_stop(struct seq_file *s, void *v)
{
kfree(v);
READ_UNLOCK(&clusterip_lock);
}
static int clusterip_seq_show(struct seq_file *s, void *v)
{
struct proc_dir_entry *pde = s->private;
struct clusterip_config *c = pde->data;
unsigned int *nodeidx = (unsigned int *)v;
if (*nodeidx != 0)
seq_putc(s, ',');
seq_printf(s, "%u", c->local_nodes[*nodeidx]);
if (*nodeidx == c->num_local_nodes-1)
seq_putc(s, '\n');
return 0;
}
static 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 proc_dir_entry *pde = PDE(inode);
struct clusterip_config *c = pde->data;
sf->private = pde;
clusterip_config_get(c);
}
return ret;
}
static int clusterip_proc_release(struct inode *inode, struct file *file)
{
struct proc_dir_entry *pde = PDE(inode);
struct clusterip_config *c = pde->data;
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 *input,
size_t size, loff_t *ofs)
{
#define PROC_WRITELEN 10
char buffer[PROC_WRITELEN+1];
struct proc_dir_entry *pde = PDE(file->f_dentry->d_inode);
struct clusterip_config *c = pde->data;
unsigned long nodenum;
if (copy_from_user(buffer, input, PROC_WRITELEN))
return -EFAULT;
if (*buffer == '+') {
nodenum = simple_strtoul(buffer+1, NULL, 10);
if (clusterip_add_node(c, nodenum))
return -ENOMEM;
} else if (*buffer == '-') {
nodenum = simple_strtoul(buffer+1, NULL,10);
if (clusterip_del_node(c, nodenum))
return -ENOENT;
} else
return -EIO;
return size;
}
static struct file_operations clusterip_proc_fops = {
.owner = THIS_MODULE,
.open = clusterip_proc_open,
.read = seq_read,
.write = clusterip_proc_write,
.llseek = seq_lseek,
.release = clusterip_proc_release,
};
#endif /* CONFIG_PROC_FS */
static int init_or_cleanup(int fini)
{
int ret;
if (fini)
goto cleanup;
if (ipt_register_target(&clusterip_tgt)) {
ret = -EINVAL;
goto cleanup_none;
}
if (nf_register_hook(&cip_arp_ops) < 0) {
ret = -EINVAL;
goto cleanup_target;
}
#ifdef CONFIG_PROC_FS
clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", proc_net);
if (!clusterip_procdir) {
printk(KERN_ERR "CLUSTERIP: Unable to proc dir entry\n");
ret = -ENOMEM;
goto cleanup_hook;
}
#endif /* CONFIG_PROC_FS */
printk(KERN_NOTICE "ClusterIP Version %s loaded successfully\n",
CLUSTERIP_VERSION);
return 0;
cleanup:
printk(KERN_NOTICE "ClusterIP Version %s unloading\n",
CLUSTERIP_VERSION);
#ifdef CONFIG_PROC_FS
remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent);
#endif
cleanup_hook:
nf_unregister_hook(&cip_arp_ops);
cleanup_target:
ipt_unregister_target(&clusterip_tgt);
cleanup_none:
return -EINVAL;
}
static int __init init(void)
{
return init_or_cleanup(0);
}
static void __exit fini(void)
{
init_or_cleanup(1);
}
module_init(init);
module_exit(fini);
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