ANDROID: net: Paranoid network.

With CONFIG_ANDROID_PARANOID_NETWORK, require specific uids/gids to instantiate
network sockets.

Signed-off-by: Robert Love <rlove@google.com>

paranoid networking: Use in_egroup_p() to check group membership

The previous group_search() caused trouble for partners with module builds.
in_egroup_p() is also cleaner.

Signed-off-by: Nick Pelly <npelly@google.com>

Fix 2.6.29 build.

Signed-off-by: Arve Hjønnevåg <arve@android.com>

net: Fix compilation of the IPv6 module

Fix compilation of the IPv6 module -- current->euid does not exist anymore,
current_euid() is what needs to be used.

Signed-off-by: Steinar H. Gunderson <sesse@google.com>

net: bluetooth: Remove the AID_NET_BT* gid numbers

Removed bluetooth checks for AID_NET_BT and AID_NET_BT_ADMIN
which are not useful anymore.
This is in preparation for getting rid of all the AID_* gids.

Change-Id: I879d7181f07532784499ef152288d12a03ab6354
Signed-off-by: JP Abgrall <jpa@google.com>

[AmitP: Folded following android-4.9 commit changes into this patch
        a2624d7b9d73 ("ANDROID: Add android_aid.h")]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

include/linux/android_aid.h

@@ -0,0 +1,25 @@
+/* include/linux/android_aid.h
+ *
+ * Copyright (C) 2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_ANDROID_AID_H
+#define _LINUX_ANDROID_AID_H
+
+/* AIDs that the kernel treats differently */
+#define AID_OBSOLETE_000 KGIDT_INIT(3001)  /* was NET_BT_ADMIN */
+#define AID_OBSOLETE_001 KGIDT_INIT(3002)  /* was NET_BT */
+#define AID_INET         KGIDT_INIT(3003)
+#define AID_NET_RAW      KGIDT_INIT(3004)
+
+#endif

net/Kconfig

@@ -92,6 +92,12 @@ source "net/netlabel/Kconfig"
 
 endif # if INET
 
+config ANDROID_PARANOID_NETWORK
+	bool "Only allow certain groups to create sockets"
+	default y
+	help
+		none
+
 config NETWORK_SECMARK
 	bool "Security Marking"
 	help

net/bluetooth/af_bluetooth.c

@@ -108,11 +108,40 @@ void bt_sock_unregister(int proto)
 }
 EXPORT_SYMBOL(bt_sock_unregister);
 
+#ifdef CONFIG_PARANOID_NETWORK
+static inline int current_has_bt_admin(void)
+{
+	return !current_euid();
+}
+
+static inline int current_has_bt(void)
+{
+	return current_has_bt_admin();
+}
+# else
+static inline int current_has_bt_admin(void)
+{
+	return 1;
+}
+
+static inline int current_has_bt(void)
+{
+	return 1;
+}
+#endif
+
 static int bt_sock_create(struct net *net, struct socket *sock, int proto,
 			  int kern)
 {
 	int err;
 
+	if (proto == BTPROTO_RFCOMM || proto == BTPROTO_SCO ||
+			proto == BTPROTO_L2CAP) {
+		if (!current_has_bt())
+			return -EPERM;
+	} else if (!current_has_bt_admin())
+		return -EPERM;
+
 	if (net != &init_net)
 		return -EAFNOSUPPORT;
 

net/ipv4/af_inet.c

@@ -123,6 +123,10 @@
 
 #include <trace/events/sock.h>
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+#include <linux/android_aid.h>
+#endif
+
 /* The inetsw table contains everything that inet_create needs to
  * build a new socket.
  */
@@ -240,6 +244,29 @@ int inet_listen(struct socket *sock, int backlog)
 }
 EXPORT_SYMBOL(inet_listen);
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+static inline int current_has_network(void)
+{
+	return (!current_euid() || in_egroup_p(AID_INET) ||
+		in_egroup_p(AID_NET_RAW));
+}
+static inline int current_has_cap(struct net *net, int cap)
+{
+	if (cap == CAP_NET_RAW && in_egroup_p(AID_NET_RAW))
+		return 1;
+	return ns_capable(net->user_ns, cap);
+}
+# else
+static inline int current_has_network(void)
+{
+	return 1;
+}
+static inline int current_has_cap(struct net *net, int cap)
+{
+	return ns_capable(net->user_ns, cap);
+}
+#endif
+
 /*
  *	Create an inet socket.
  */
@@ -258,6 +285,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 	if (protocol < 0 || protocol >= IPPROTO_MAX)
 		return -EINVAL;
 
+	if (!current_has_network())
+		return -EACCES;
+
 	sock->state = SS_UNCONNECTED;
 
 	/* Look for the requested type/protocol pair. */
@@ -307,7 +337,7 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 
 	err = -EPERM;
 	if (sock->type == SOCK_RAW && !kern &&
-	    !ns_capable(net->user_ns, CAP_NET_RAW))
+	    !current_has_cap(net, CAP_NET_RAW))
 		goto out_rcu_unlock;
 
 	sock->ops = answer->ops;

net/ipv6/af_inet6.c

@@ -66,6 +66,10 @@
 #include <linux/uaccess.h>
 #include <linux/mroute6.h>
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+#include <linux/android_aid.h>
+#endif
+
 #include "ip6_offload.h"
 
 MODULE_AUTHOR("Cast of dozens");
@@ -107,6 +111,29 @@ static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
 	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
 }
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+static inline int current_has_network(void)
+{
+	return (!current_euid() || in_egroup_p(AID_INET) ||
+		in_egroup_p(AID_NET_RAW));
+}
+static inline int current_has_cap(struct net *net, int cap)
+{
+	if (cap == CAP_NET_RAW && in_egroup_p(AID_NET_RAW))
+		return 1;
+	return ns_capable(net->user_ns, cap);
+}
+# else
+static inline int current_has_network(void)
+{
+	return 1;
+}
+static inline int current_has_cap(struct net *net, int cap)
+{
+	return ns_capable(net->user_ns, cap);
+}
+#endif
+
 static int inet6_create(struct net *net, struct socket *sock, int protocol,
 			int kern)
 {
@@ -122,6 +149,9 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
 	if (protocol < 0 || protocol >= IPPROTO_MAX)
 		return -EINVAL;
 
+	if (!current_has_network())
+		return -EACCES;
+
 	/* Look for the requested type/protocol pair. */
 lookup_protocol:
 	err = -ESOCKTNOSUPPORT;
@@ -169,7 +199,7 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
 
 	err = -EPERM;
 	if (sock->type == SOCK_RAW && !kern &&
-	    !ns_capable(net->user_ns, CAP_NET_RAW))
+	    !current_has_cap(net, CAP_NET_RAW))
 		goto out_rcu_unlock;
 
 	sock->ops = answer->ops;