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/*
* Kernel module to match various things tied to sockets associated with
* locally generated outgoing packets.
*
* (C) 2000 Marc Boucher <marc@mbsi.ca>
*
* Copyright © CC Computer Consultants GmbH, 2007 - 2008
* <jengelh@computergmbh.de>
*
* 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/skbuff.h>
#include <linux/file.h>
#include <net/sock.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_owner.h>
#include <linux/netfilter_ipv4/ipt_owner.h>
#include <linux/netfilter_ipv6/ip6t_owner.h>
static bool
owner_mt_v0(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop)
{
const struct ipt_owner_info *info = matchinfo;
const struct file *filp;
if (skb->sk == NULL || skb->sk->sk_socket == NULL)
return false;
filp = skb->sk->sk_socket->file;
if (filp == NULL)
return false;
if (info->match & IPT_OWNER_UID)
if ((filp->f_uid != info->uid) ^
!!(info->invert & IPT_OWNER_UID))
return false;
if (info->match & IPT_OWNER_GID)
if ((filp->f_gid != info->gid) ^
!!(info->invert & IPT_OWNER_GID))
return false;
return true;
}
static bool
owner_mt6_v0(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop)
{
const struct ip6t_owner_info *info = matchinfo;
const struct file *filp;
if (skb->sk == NULL || skb->sk->sk_socket == NULL)
return false;
filp = skb->sk->sk_socket->file;
if (filp == NULL)
return false;
if (info->match & IP6T_OWNER_UID)
if ((filp->f_uid != info->uid) ^
!!(info->invert & IP6T_OWNER_UID))
return false;
if (info->match & IP6T_OWNER_GID)
if ((filp->f_gid != info->gid) ^
!!(info->invert & IP6T_OWNER_GID))
return false;
return true;
}
static bool
owner_mt(const struct sk_buff *skb, const struct net_device *in,
const struct net_device *out, const struct xt_match *match,
const void *matchinfo, int offset, unsigned int protoff,
bool *hotdrop)
{
const struct xt_owner_match_info *info = matchinfo;
const struct file *filp;
if (skb->sk == NULL || skb->sk->sk_socket == NULL)
return (info->match ^ info->invert) == 0;
else if (info->match & info->invert & XT_OWNER_SOCKET)
/*
* Socket exists but user wanted ! --socket-exists.
* (Single ampersands intended.)
*/
return false;
filp = skb->sk->sk_socket->file;
if (filp == NULL)
return ((info->match ^ info->invert) &
(XT_OWNER_UID | XT_OWNER_GID)) == 0;
if (info->match & XT_OWNER_UID)
if ((filp->f_uid >= info->uid_min &&
filp->f_uid <= info->uid_max) ^
!(info->invert & XT_OWNER_UID))
return false;
if (info->match & XT_OWNER_GID)
if ((filp->f_gid >= info->gid_min &&
filp->f_gid <= info->gid_max) ^
!(info->invert & XT_OWNER_GID))
return false;
return true;
}
static bool
owner_mt_check_v0(const char *tablename, const void *ip,
const struct xt_match *match, void *matchinfo,
unsigned int hook_mask)
{
const struct ipt_owner_info *info = matchinfo;
if (info->match & (IPT_OWNER_PID | IPT_OWNER_SID | IPT_OWNER_COMM)) {
printk(KERN_WARNING KBUILD_MODNAME
": PID, SID and command matching is not "
"supported anymore\n");
return false;
}
return true;
}
static bool
owner_mt6_check_v0(const char *tablename, const void *ip,
const struct xt_match *match, void *matchinfo,
unsigned int hook_mask)
{
const struct ip6t_owner_info *info = matchinfo;
if (info->match & (IP6T_OWNER_PID | IP6T_OWNER_SID)) {
printk(KERN_WARNING KBUILD_MODNAME
": PID and SID matching is not supported anymore\n");
return false;
}
return true;
}
static struct xt_match owner_mt_reg[] __read_mostly = {
{
.name = "owner",
.revision = 0,
.family = NFPROTO_IPV4,
.match = owner_mt_v0,
.matchsize = sizeof(struct ipt_owner_info),
.checkentry = owner_mt_check_v0,
.hooks = (1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_POST_ROUTING),
.me = THIS_MODULE,
},
{
.name = "owner",
.revision = 0,
.family = NFPROTO_IPV6,
.match = owner_mt6_v0,
.matchsize = sizeof(struct ip6t_owner_info),
.checkentry = owner_mt6_check_v0,
.hooks = (1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_POST_ROUTING),
.me = THIS_MODULE,
},
{
.name = "owner",
.revision = 1,
.family = NFPROTO_IPV4,
.match = owner_mt,
.matchsize = sizeof(struct xt_owner_match_info),
.hooks = (1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_POST_ROUTING),
.me = THIS_MODULE,
},
{
.name = "owner",
.revision = 1,
.family = NFPROTO_IPV6,
.match = owner_mt,
.matchsize = sizeof(struct xt_owner_match_info),
.hooks = (1 << NF_INET_LOCAL_OUT) |
(1 << NF_INET_POST_ROUTING),
.me = THIS_MODULE,
},
};
static int __init owner_mt_init(void)
{
return xt_register_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
}
static void __exit owner_mt_exit(void)
{
xt_unregister_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
}
module_init(owner_mt_init);
module_exit(owner_mt_exit);
MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
MODULE_DESCRIPTION("Xtables: socket owner matching");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_owner");
MODULE_ALIAS("ip6t_owner");
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