[NETFILTER]: merge ipt_owner/ip6t_owner in xt_owner

xt_owner merges ipt_owner and ip6t_owner, and adds a flag to match
on socket (non-)existence.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 211 insertions, 0 deletions

diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c
new file mode 100644
index 0000000..4222fa2
--- /dev/null
+++ b/net/netfilter/xt_owner.c
@@ -0,0 +1,211 @@
+/*
+ * 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
+ * Contact: <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) ^
+		    !!(info->invert & XT_OWNER_UID))
+			return false;
+
+	if (info->match & XT_OWNER_GID)
+		if ((filp->f_gid != info->gid) ^
+		    !!(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     = AF_INET,
+		.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     = AF_INET6,
+		.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     = AF_INET,
+		.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     = AF_INET6,
+		.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("netfilter \"owner\" match module");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_owner");
+MODULE_ALIAS("ip6t_owner");