"condition" patch for kernel 2.6

"condition" patch for kernel 2.6

[afshin lamei]

dear all,
1- I want to use the "condition" patch in kernel 2.6.x, I remember
that it was available only for kernel 2.4.x. Is it available now for
2.6?

regards,
afshin

Re: "condition" patch for kernel 2.6

[KOVACS Krisztian]

[-- Attachment #1: Type: text/plain, Size: 341 bytes --]


  Hi,

On Monday 26 September 2005 13.39, afshin lamei wrote:
> dear all,
> 1- I want to use the "condition" patch in kernel 2.6.x, I remember
> that it was available only for kernel 2.4.x. Is it available now for
> 2.6?

  Yes, I've attached it. Unofficial, not supported, etc. I've used it 
with 2.6.11.

-- 
 Regards,
  Krisztian Kovacs

[-- Attachment #2: ipt_condition.patch --]
[-- Type: text/x-diff, Size: 8553 bytes --]

Index: linux-2.6.11-ipsec/net/ipv4/netfilter/ipt_condition.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.11-ipsec/net/ipv4/netfilter/ipt_condition.c	2005-03-03 15:17:53.826807876 +0100
@@ -0,0 +1,259 @@
+/*-------------------------------------------*\
+|          Netfilter Condition Module         |
+|                                             |
+|  Description: This module allows firewall   |
+|    rules to match using condition variables |
+|    stored in /proc files.                   |
+|                                             |
+|  Author: Stephane Ouellette     2002-10-22  |
+|          <ouellettes@videotron.ca>          |
+|                                             |
+|  History:                                   |
+|    2003-02-10  Second version with improved |
+|                locking and simplified code. |
+|                                             |
+|  This software is distributed under the     |
+|  terms of the GNU GPL.                      |
+\*-------------------------------------------*/
+
+#include<linux/module.h>
+#include<linux/proc_fs.h>
+#include<linux/spinlock.h>
+#include<linux/string.h>
+#include<asm/atomic.h>
+#include<linux/netfilter_ipv4/ip_tables.h>
+#include<linux/netfilter_ipv4/ipt_condition.h>
+
+
+#ifndef CONFIG_PROC_FS
+#error  "Proc file system support is required for this module"
+#endif
+
+
+MODULE_AUTHOR("Stephane Ouellette <ouellettes@videotron.ca>");
+MODULE_DESCRIPTION("Allows rules to match against condition variables");
+MODULE_LICENSE("GPL");
+
+
+struct condition_variable {
+	struct condition_variable *next;
+	struct proc_dir_entry *status_proc;
+	atomic_t refcount;
+        int enabled;   /* TRUE == 1, FALSE == 0 */
+};
+
+
+static rwlock_t list_lock;
+static struct condition_variable *head = NULL;
+static struct proc_dir_entry *proc_net_condition = NULL;
+
+
+static int
+ipt_condition_read_info(char *buffer, char **start, off_t offset,
+			int length, int *eof, void *data)
+{
+	struct condition_variable *var =
+	    (struct condition_variable *) data;
+
+	if (offset == 0) {
+		*start = buffer;
+		buffer[0] = (var->enabled) ? '1' : '0';
+		buffer[1] = '\n';
+		return 2;
+	}
+
+	*eof = 1;
+	return 0;
+}
+
+
+static int
+ipt_condition_write_info(struct file *file, const char *buffer,
+			 unsigned long length, void *data)
+{
+	struct condition_variable *var =
+	    (struct condition_variable *) data;
+
+	if (length) {
+	        /* Match only on the first character */
+		switch (buffer[0]) {
+		case '0':
+			var->enabled = 0;
+			break;
+		case '1':
+			var->enabled = 1;
+		}
+	}
+
+	return (int) length;
+}
+
+
+static int
+match(const struct sk_buff *skb,
+      const struct net_device *in,
+      const struct net_device *out,
+      const void *matchinfo,
+      int offset,
+      int *hotdrop)
+{
+	const struct condition_info *info =
+	    (const struct condition_info *) matchinfo;
+	struct condition_variable *var;
+	int condition_status = 0;
+
+	read_lock(&list_lock);
+
+	for (var = head; var; var = var->next) {
+		if (strcmp(info->name, var->status_proc->name) == 0) {
+			condition_status = var->enabled;
+			break;
+		}
+	}
+
+	read_unlock(&list_lock);
+
+	return condition_status ^ info->invert;
+}
+
+
+
+static int
+checkentry(const char *tablename, const struct ipt_ip *ip,
+	   void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
+{
+	struct condition_info *info = (struct condition_info *) matchinfo;
+	struct condition_variable *var, *newvar;
+
+	if (matchsize != IPT_ALIGN(sizeof(struct condition_info)))
+		return 0;
+
+	/* The first step is to check if the condition variable already exists. */
+	/* Here, a read lock is sufficient because we won't change the list */
+	read_lock(&list_lock);
+
+	for (var = head; var; var = var->next) {
+		if (strcmp(info->name, var->status_proc->name) == 0) {
+			atomic_inc(&var->refcount);
+			read_unlock(&list_lock);
+			return 1;
+		}
+	}
+
+	read_unlock(&list_lock);
+
+	/* At this point, we need to allocate a new condition variable */
+	newvar = kmalloc(sizeof(struct condition_variable), GFP_KERNEL);
+
+	if (!newvar)
+		return -ENOMEM;
+
+	/* Create the condition variable's proc file entry */
+	newvar->status_proc = create_proc_entry(info->name, 0644, proc_net_condition);
+
+	if (!newvar->status_proc) {
+	  /*
+	   * There are two possibilities:
+	   *  1- Another condition variable with the same name has been created, which is valid.
+	   *  2- There was a memory allocation error.
+	   */
+		kfree(newvar);
+		read_lock(&list_lock);
+
+		for (var = head; var; var = var->next) {
+			if (strcmp(info->name, var->status_proc->name) == 0) {
+				atomic_inc(&var->refcount);
+				read_unlock(&list_lock);
+				return 1;
+			}
+		}
+
+		read_unlock(&list_lock);
+		return -ENOMEM;
+	}
+
+	atomic_set(&newvar->refcount, 1);
+	newvar->enabled = 0;
+	newvar->status_proc->owner = THIS_MODULE;
+	newvar->status_proc->data = newvar;
+	wmb();
+	newvar->status_proc->read_proc = ipt_condition_read_info;
+	newvar->status_proc->write_proc = ipt_condition_write_info;
+
+	write_lock(&list_lock);
+
+	newvar->next = head;
+	head = newvar;
+
+	write_unlock(&list_lock);
+
+	return 1;
+}
+
+
+static void
+destroy(void *matchinfo, unsigned int matchsize)
+{
+	struct condition_info *info = (struct condition_info *) matchinfo;
+	struct condition_variable *var, *prev = NULL;
+
+	if (matchsize != IPT_ALIGN(sizeof(struct condition_info)))
+		return;
+
+	write_lock(&list_lock);
+
+	for (var = head; var && strcmp(info->name, var->status_proc->name);
+	     prev = var, var = var->next);
+
+	if (var && atomic_dec_and_test(&var->refcount)) {
+		if (prev)
+			prev->next = var->next;
+		else
+			head = var->next;
+
+		write_unlock(&list_lock);
+		remove_proc_entry(var->status_proc->name, proc_net_condition);
+		kfree(var);
+	} else
+		write_unlock(&list_lock);
+}
+
+
+static struct ipt_match condition_match = {
+	.name = "condition",
+	.match = &match,
+	.checkentry = &checkentry,
+	.destroy = &destroy,
+	.me = THIS_MODULE
+};
+
+
+static int __init
+init(void)
+{
+	int errorcode;
+
+	rwlock_init(&list_lock);
+	proc_net_condition = proc_mkdir("ipt_condition", proc_net);
+
+	if (proc_net_condition) {
+	        errorcode = ipt_register_match(&condition_match);
+
+		if (errorcode)
+			remove_proc_entry("ipt_condition", proc_net);
+	} else
+		errorcode = -EACCES;
+
+	return errorcode;
+}
+
+
+static void __exit
+fini(void)
+{
+	ipt_unregister_match(&condition_match);
+	remove_proc_entry("ipt_condition", proc_net);
+}
+
+module_init(init);
+module_exit(fini);
Index: linux-2.6.11-ipsec/net/ipv4/netfilter/Makefile
===================================================================
--- linux-2.6.11-ipsec.orig/net/ipv4/netfilter/Makefile	2005-03-03 15:17:50.724537092 +0100
+++ linux-2.6.11-ipsec/net/ipv4/netfilter/Makefile	2005-03-03 15:17:53.826807876 +0100
@@ -60,6 +60,7 @@
 obj-$(CONFIG_IP_NF_MATCH_PHYSDEV) += ipt_physdev.o
 obj-$(CONFIG_IP_NF_MATCH_COMMENT) += ipt_comment.o
 obj-$(CONFIG_IP_NF_MATCH_U32) += ipt_u32.o
+obj-$(CONFIG_IP_NF_MATCH_CONDITION) += ipt_condition.o
 
 # targets
 obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
Index: linux-2.6.11-ipsec/include/linux/netfilter_ipv4/ipt_condition.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.11-ipsec/include/linux/netfilter_ipv4/ipt_condition.h	2005-03-03 15:17:53.827807641 +0100
@@ -0,0 +1,11 @@
+#ifndef __IPT_CONDITION_MATCH__
+#define __IPT_CONDITION_MATCH__
+
+#define CONDITION_NAME_LEN  32
+
+struct condition_info {
+	char name[CONDITION_NAME_LEN];
+	int  invert;
+};
+
+#endif
Index: linux-2.6.11-ipsec/net/ipv4/netfilter/Kconfig
===================================================================
--- linux-2.6.11-ipsec.orig/net/ipv4/netfilter/Kconfig	2005-03-03 15:17:50.725536857 +0100
+++ linux-2.6.11-ipsec/net/ipv4/netfilter/Kconfig	2005-03-03 15:17:53.828807406 +0100
@@ -388,6 +388,16 @@
 	
 	  Details and examples are in the kernel module source.	
 
+config IP_NF_MATCH_CONDITION
+	tristate  'condition match support'
+	depends on IP_NF_IPTABLES
+	help
+	  This option allows you to match firewall rules against condition
+	  variables stored in the /proc/net/ipt_condition directory.
+
+	  If you want to compile it as a module, say M here and read
+	  Documentation/modules.txt.  If unsure, say `N'.
+
 # `filter', generic and specific targets
 config IP_NF_FILTER
 	tristate "Packet filtering"

Re: "condition" patch for kernel 2.6

[Samuel Díaz García]

Don't need any patch for iptables?

Thanks

KOVACS Krisztian escribió:

>   Hi,
> 
> On Monday 26 September 2005 13.39, afshin lamei wrote:
> 
>>dear all,
>>1- I want to use the "condition" patch in kernel 2.6.x, I remember
>>that it was available only for kernel 2.4.x. Is it available now for
>>2.6?
> 
> 
>   Yes, I've attached it. Unofficial, not supported, etc. I've used it 
> with 2.6.11.
> 
> 
> 
> ------------------------------------------------------------------------
> 
> Index: linux-2.6.11-ipsec/net/ipv4/netfilter/ipt_condition.c
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6.11-ipsec/net/ipv4/netfilter/ipt_condition.c	2005-03-03 15:17:53.826807876 +0100
> @@ -0,0 +1,259 @@
> +/*-------------------------------------------*\
> +|          Netfilter Condition Module         |
> +|                                             |
> +|  Description: This module allows firewall   |
> +|    rules to match using condition variables |
> +|    stored in /proc files.                   |
> +|                                             |
> +|  Author: Stephane Ouellette     2002-10-22  |
> +|          <ouellettes@videotron.ca>          |
> +|                                             |
> +|  History:                                   |
> +|    2003-02-10  Second version with improved |
> +|                locking and simplified code. |
> +|                                             |
> +|  This software is distributed under the     |
> +|  terms of the GNU GPL.                      |
> +\*-------------------------------------------*/
> +
> +#include<linux/module.h>
> +#include<linux/proc_fs.h>
> +#include<linux/spinlock.h>
> +#include<linux/string.h>
> +#include<asm/atomic.h>
> +#include<linux/netfilter_ipv4/ip_tables.h>
> +#include<linux/netfilter_ipv4/ipt_condition.h>
> +
> +
> +#ifndef CONFIG_PROC_FS
> +#error  "Proc file system support is required for this module"
> +#endif
> +
> +
> +MODULE_AUTHOR("Stephane Ouellette <ouellettes@videotron.ca>");
> +MODULE_DESCRIPTION("Allows rules to match against condition variables");
> +MODULE_LICENSE("GPL");
> +
> +
> +struct condition_variable {
> +	struct condition_variable *next;
> +	struct proc_dir_entry *status_proc;
> +	atomic_t refcount;
> +        int enabled;   /* TRUE == 1, FALSE == 0 */
> +};
> +
> +
> +static rwlock_t list_lock;
> +static struct condition_variable *head = NULL;
> +static struct proc_dir_entry *proc_net_condition = NULL;
> +
> +
> +static int
> +ipt_condition_read_info(char *buffer, char **start, off_t offset,
> +			int length, int *eof, void *data)
> +{
> +	struct condition_variable *var =
> +	    (struct condition_variable *) data;
> +
> +	if (offset == 0) {
> +		*start = buffer;
> +		buffer[0] = (var->enabled) ? '1' : '0';
> +		buffer[1] = '\n';
> +		return 2;
> +	}
> +
> +	*eof = 1;
> +	return 0;
> +}
> +
> +
> +static int
> +ipt_condition_write_info(struct file *file, const char *buffer,
> +			 unsigned long length, void *data)
> +{
> +	struct condition_variable *var =
> +	    (struct condition_variable *) data;
> +
> +	if (length) {
> +	        /* Match only on the first character */
> +		switch (buffer[0]) {
> +		case '0':
> +			var->enabled = 0;
> +			break;
> +		case '1':
> +			var->enabled = 1;
> +		}
> +	}
> +
> +	return (int) length;
> +}
> +
> +
> +static int
> +match(const struct sk_buff *skb,
> +      const struct net_device *in,
> +      const struct net_device *out,
> +      const void *matchinfo,
> +      int offset,
> +      int *hotdrop)
> +{
> +	const struct condition_info *info =
> +	    (const struct condition_info *) matchinfo;
> +	struct condition_variable *var;
> +	int condition_status = 0;
> +
> +	read_lock(&list_lock);
> +
> +	for (var = head; var; var = var->next) {
> +		if (strcmp(info->name, var->status_proc->name) == 0) {
> +			condition_status = var->enabled;
> +			break;
> +		}
> +	}
> +
> +	read_unlock(&list_lock);
> +
> +	return condition_status ^ info->invert;
> +}
> +
> +
> +
> +static int
> +checkentry(const char *tablename, const struct ipt_ip *ip,
> +	   void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
> +{
> +	struct condition_info *info = (struct condition_info *) matchinfo;
> +	struct condition_variable *var, *newvar;
> +
> +	if (matchsize != IPT_ALIGN(sizeof(struct condition_info)))
> +		return 0;
> +
> +	/* The first step is to check if the condition variable already exists. */
> +	/* Here, a read lock is sufficient because we won't change the list */
> +	read_lock(&list_lock);
> +
> +	for (var = head; var; var = var->next) {
> +		if (strcmp(info->name, var->status_proc->name) == 0) {
> +			atomic_inc(&var->refcount);
> +			read_unlock(&list_lock);
> +			return 1;
> +		}
> +	}
> +
> +	read_unlock(&list_lock);
> +
> +	/* At this point, we need to allocate a new condition variable */
> +	newvar = kmalloc(sizeof(struct condition_variable), GFP_KERNEL);
> +
> +	if (!newvar)
> +		return -ENOMEM;
> +
> +	/* Create the condition variable's proc file entry */
> +	newvar->status_proc = create_proc_entry(info->name, 0644, proc_net_condition);
> +
> +	if (!newvar->status_proc) {
> +	  /*
> +	   * There are two possibilities:
> +	   *  1- Another condition variable with the same name has been created, which is valid.
> +	   *  2- There was a memory allocation error.
> +	   */
> +		kfree(newvar);
> +		read_lock(&list_lock);
> +
> +		for (var = head; var; var = var->next) {
> +			if (strcmp(info->name, var->status_proc->name) == 0) {
> +				atomic_inc(&var->refcount);
> +				read_unlock(&list_lock);
> +				return 1;
> +			}
> +		}
> +
> +		read_unlock(&list_lock);
> +		return -ENOMEM;
> +	}
> +
> +	atomic_set(&newvar->refcount, 1);
> +	newvar->enabled = 0;
> +	newvar->status_proc->owner = THIS_MODULE;
> +	newvar->status_proc->data = newvar;
> +	wmb();
> +	newvar->status_proc->read_proc = ipt_condition_read_info;
> +	newvar->status_proc->write_proc = ipt_condition_write_info;
> +
> +	write_lock(&list_lock);
> +
> +	newvar->next = head;
> +	head = newvar;
> +
> +	write_unlock(&list_lock);
> +
> +	return 1;
> +}
> +
> +
> +static void
> +destroy(void *matchinfo, unsigned int matchsize)
> +{
> +	struct condition_info *info = (struct condition_info *) matchinfo;
> +	struct condition_variable *var, *prev = NULL;
> +
> +	if (matchsize != IPT_ALIGN(sizeof(struct condition_info)))
> +		return;
> +
> +	write_lock(&list_lock);
> +
> +	for (var = head; var && strcmp(info->name, var->status_proc->name);
> +	     prev = var, var = var->next);
> +
> +	if (var && atomic_dec_and_test(&var->refcount)) {
> +		if (prev)
> +			prev->next = var->next;
> +		else
> +			head = var->next;
> +
> +		write_unlock(&list_lock);
> +		remove_proc_entry(var->status_proc->name, proc_net_condition);
> +		kfree(var);
> +	} else
> +		write_unlock(&list_lock);
> +}
> +
> +
> +static struct ipt_match condition_match = {
> +	.name = "condition",
> +	.match = &match,
> +	.checkentry = &checkentry,
> +	.destroy = &destroy,
> +	.me = THIS_MODULE
> +};
> +
> +
> +static int __init
> +init(void)
> +{
> +	int errorcode;
> +
> +	rwlock_init(&list_lock);
> +	proc_net_condition = proc_mkdir("ipt_condition", proc_net);
> +
> +	if (proc_net_condition) {
> +	        errorcode = ipt_register_match(&condition_match);
> +
> +		if (errorcode)
> +			remove_proc_entry("ipt_condition", proc_net);
> +	} else
> +		errorcode = -EACCES;
> +
> +	return errorcode;
> +}
> +
> +
> +static void __exit
> +fini(void)
> +{
> +	ipt_unregister_match(&condition_match);
> +	remove_proc_entry("ipt_condition", proc_net);
> +}
> +
> +module_init(init);
> +module_exit(fini);
> Index: linux-2.6.11-ipsec/net/ipv4/netfilter/Makefile
> ===================================================================
> --- linux-2.6.11-ipsec.orig/net/ipv4/netfilter/Makefile	2005-03-03 15:17:50.724537092 +0100
> +++ linux-2.6.11-ipsec/net/ipv4/netfilter/Makefile	2005-03-03 15:17:53.826807876 +0100
> @@ -60,6 +60,7 @@
>  obj-$(CONFIG_IP_NF_MATCH_PHYSDEV) += ipt_physdev.o
>  obj-$(CONFIG_IP_NF_MATCH_COMMENT) += ipt_comment.o
>  obj-$(CONFIG_IP_NF_MATCH_U32) += ipt_u32.o
> +obj-$(CONFIG_IP_NF_MATCH_CONDITION) += ipt_condition.o
>  
>  # targets
>  obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
> Index: linux-2.6.11-ipsec/include/linux/netfilter_ipv4/ipt_condition.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6.11-ipsec/include/linux/netfilter_ipv4/ipt_condition.h	2005-03-03 15:17:53.827807641 +0100
> @@ -0,0 +1,11 @@
> +#ifndef __IPT_CONDITION_MATCH__
> +#define __IPT_CONDITION_MATCH__
> +
> +#define CONDITION_NAME_LEN  32
> +
> +struct condition_info {
> +	char name[CONDITION_NAME_LEN];
> +	int  invert;
> +};
> +
> +#endif
> Index: linux-2.6.11-ipsec/net/ipv4/netfilter/Kconfig
> ===================================================================
> --- linux-2.6.11-ipsec.orig/net/ipv4/netfilter/Kconfig	2005-03-03 15:17:50.725536857 +0100
> +++ linux-2.6.11-ipsec/net/ipv4/netfilter/Kconfig	2005-03-03 15:17:53.828807406 +0100
> @@ -388,6 +388,16 @@
>  	
>  	  Details and examples are in the kernel module source.	
>  
> +config IP_NF_MATCH_CONDITION
> +	tristate  'condition match support'
> +	depends on IP_NF_IPTABLES
> +	help
> +	  This option allows you to match firewall rules against condition
> +	  variables stored in the /proc/net/ipt_condition directory.
> +
> +	  If you want to compile it as a module, say M here and read
> +	  Documentation/modules.txt.  If unsure, say `N'.
> +
>  # `filter', generic and specific targets
>  config IP_NF_FILTER
>  	tristate "Packet filtering"

-- 
    Samuel Díaz García
     Director Gerente
ArcosCom Wireless, S.L.L.

CIF: B11828068
c/ Romero Gago, 19
Arcos de la Frontera
11630 - Cadiz

http://www.arcoscom.com

mailto:samueldg@arcoscom.com
msn: samueldg@arcoscom.com

Móvil: 651 93 72 48
Tlfn.: 956 70 13 15
Fax:   956 70 34 83

Re: "condition" patch for kernel 2.6

[KOVACS Krisztian]

  Hi,

On Sunday 01 January 2006 23.10, Samuel Díaz García wrote:
> Don't need any patch for iptables?

  It's included in the latest iptables release. For older iptables versions 
(1.2.x) you should use the same patch for 2.4 as for 2.6.

-- 
 Regards,
  Krisztian Kovacs