214 lines
5.7 KiB
C
214 lines
5.7 KiB
C
/*
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* Kernel module to match various things tied to sockets associated with
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* locally generated outgoing packets.
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*
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* (C) 2000 Marc Boucher <marc@mbsi.ca>
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*
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* Copyright © CC Computer Consultants GmbH, 2007 - 2008
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* <jengelh@computergmbh.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/file.h>
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#include <net/sock.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_owner.h>
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#include <linux/netfilter_ipv4/ipt_owner.h>
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#include <linux/netfilter_ipv6/ip6t_owner.h>
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static bool
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owner_mt_v0(const struct sk_buff *skb, const struct net_device *in,
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const struct net_device *out, const struct xt_match *match,
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const void *matchinfo, int offset, unsigned int protoff,
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bool *hotdrop)
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{
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const struct ipt_owner_info *info = matchinfo;
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const struct file *filp;
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if (skb->sk == NULL || skb->sk->sk_socket == NULL)
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return false;
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filp = skb->sk->sk_socket->file;
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if (filp == NULL)
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return false;
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if (info->match & IPT_OWNER_UID)
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if ((filp->f_uid != info->uid) ^
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!!(info->invert & IPT_OWNER_UID))
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return false;
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if (info->match & IPT_OWNER_GID)
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if ((filp->f_gid != info->gid) ^
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!!(info->invert & IPT_OWNER_GID))
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return false;
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return true;
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}
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static bool
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owner_mt6_v0(const struct sk_buff *skb, const struct net_device *in,
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const struct net_device *out, const struct xt_match *match,
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const void *matchinfo, int offset, unsigned int protoff,
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bool *hotdrop)
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{
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const struct ip6t_owner_info *info = matchinfo;
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const struct file *filp;
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if (skb->sk == NULL || skb->sk->sk_socket == NULL)
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return false;
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filp = skb->sk->sk_socket->file;
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if (filp == NULL)
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return false;
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if (info->match & IP6T_OWNER_UID)
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if ((filp->f_uid != info->uid) ^
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!!(info->invert & IP6T_OWNER_UID))
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return false;
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if (info->match & IP6T_OWNER_GID)
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if ((filp->f_gid != info->gid) ^
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!!(info->invert & IP6T_OWNER_GID))
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return false;
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return true;
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}
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static bool
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owner_mt(const struct sk_buff *skb, const struct net_device *in,
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const struct net_device *out, const struct xt_match *match,
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const void *matchinfo, int offset, unsigned int protoff,
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bool *hotdrop)
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{
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const struct xt_owner_match_info *info = matchinfo;
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const struct file *filp;
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if (skb->sk == NULL || skb->sk->sk_socket == NULL)
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return (info->match ^ info->invert) == 0;
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else if (info->match & info->invert & XT_OWNER_SOCKET)
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/*
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* Socket exists but user wanted ! --socket-exists.
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* (Single ampersands intended.)
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*/
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return false;
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filp = skb->sk->sk_socket->file;
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if (filp == NULL)
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return ((info->match ^ info->invert) &
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(XT_OWNER_UID | XT_OWNER_GID)) == 0;
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if (info->match & XT_OWNER_UID)
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if ((filp->f_uid >= info->uid_min &&
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filp->f_uid <= info->uid_max) ^
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!(info->invert & XT_OWNER_UID))
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return false;
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if (info->match & XT_OWNER_GID)
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if ((filp->f_gid >= info->gid_min &&
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filp->f_gid <= info->gid_max) ^
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!(info->invert & XT_OWNER_GID))
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return false;
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return true;
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}
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static bool
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owner_mt_check_v0(const char *tablename, const void *ip,
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const struct xt_match *match, void *matchinfo,
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unsigned int hook_mask)
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{
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const struct ipt_owner_info *info = matchinfo;
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if (info->match & (IPT_OWNER_PID | IPT_OWNER_SID | IPT_OWNER_COMM)) {
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printk(KERN_WARNING KBUILD_MODNAME
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": PID, SID and command matching is not "
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"supported anymore\n");
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return false;
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}
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return true;
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}
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static bool
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owner_mt6_check_v0(const char *tablename, const void *ip,
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const struct xt_match *match, void *matchinfo,
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unsigned int hook_mask)
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{
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const struct ip6t_owner_info *info = matchinfo;
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if (info->match & (IP6T_OWNER_PID | IP6T_OWNER_SID)) {
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printk(KERN_WARNING KBUILD_MODNAME
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": PID and SID matching is not supported anymore\n");
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return false;
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}
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return true;
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}
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static struct xt_match owner_mt_reg[] __read_mostly = {
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{
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.name = "owner",
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.revision = 0,
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.family = AF_INET,
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.match = owner_mt_v0,
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.matchsize = sizeof(struct ipt_owner_info),
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.checkentry = owner_mt_check_v0,
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.hooks = (1 << NF_INET_LOCAL_OUT) |
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(1 << NF_INET_POST_ROUTING),
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.me = THIS_MODULE,
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},
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{
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.name = "owner",
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.revision = 0,
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.family = AF_INET6,
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.match = owner_mt6_v0,
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.matchsize = sizeof(struct ip6t_owner_info),
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.checkentry = owner_mt6_check_v0,
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.hooks = (1 << NF_INET_LOCAL_OUT) |
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(1 << NF_INET_POST_ROUTING),
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.me = THIS_MODULE,
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},
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{
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.name = "owner",
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.revision = 1,
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.family = AF_INET,
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.match = owner_mt,
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.matchsize = sizeof(struct xt_owner_match_info),
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.hooks = (1 << NF_INET_LOCAL_OUT) |
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(1 << NF_INET_POST_ROUTING),
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.me = THIS_MODULE,
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},
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{
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.name = "owner",
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.revision = 1,
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.family = AF_INET6,
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.match = owner_mt,
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.matchsize = sizeof(struct xt_owner_match_info),
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.hooks = (1 << NF_INET_LOCAL_OUT) |
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(1 << NF_INET_POST_ROUTING),
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.me = THIS_MODULE,
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},
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};
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static int __init owner_mt_init(void)
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{
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return xt_register_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
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}
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static void __exit owner_mt_exit(void)
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{
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xt_unregister_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
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}
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module_init(owner_mt_init);
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module_exit(owner_mt_exit);
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MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
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MODULE_DESCRIPTION("Xtables: socket owner matching");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_owner");
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MODULE_ALIAS("ip6t_owner");
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