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>

4 files changed, 106 insertions, 2 deletions

diff --git a/net/Kconfig b/net/Kconfig
index cdb8fdef6c4a..5250712fae9f 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -61,6 +61,12 @@ 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
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 02b9baa1930b..ba8860e73cae 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -41,6 +41,15 @@
 
 #include <net/bluetooth/bluetooth.h>
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+#include <linux/android_aid.h>
+#endif
+
+#ifndef CONFIG_BT_SOCK_DEBUG
+#undef  BT_DBG
+#define BT_DBG(D...)
+#endif
+
 #define VERSION "2.15"
 
 /* Bluetooth sockets */
@@ -126,10 +135,39 @@ int bt_sock_unregister(int proto)
 }
 EXPORT_SYMBOL(bt_sock_unregister);
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+static inline int current_has_bt_admin(void)
+{
+	return (!current_euid() || in_egroup_p(AID_NET_BT_ADMIN));
+}
+
+static inline int current_has_bt(void)
+{
+	return (current_has_bt_admin() || in_egroup_p(AID_NET_BT));
+}
+# 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 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;
 
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 743f5542d65a..27410c339e19 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -116,6 +116,10 @@
 #include <linux/mroute.h>
 #endif
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+#include <linux/android_aid.h>
+#endif
+
 extern void ip_mc_drop_socket(struct sock *sk);
 
 /* The inetsw table contains everything that inet_create needs to
@@ -258,6 +262,29 @@ static inline int inet_netns_ok(struct net *net, int protocol)
 	return ipprot->netns_ok;
 }
 
+#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(int cap)
+{
+	if (cap == CAP_NET_RAW && in_egroup_p(AID_NET_RAW))
+		return 1;
+	return capable(cap);
+}
+# else
+static inline int current_has_network(void)
+{
+	return 1;
+}
+static inline int current_has_cap(int cap)
+{
+	return capable(cap);
+}
+#endif
+
 /*
  *	Create an inet socket.
  */
@@ -273,6 +300,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol)
 	int try_loading_module = 0;
 	int err;
 
+	if (!current_has_network())
+		return -EACCES;
+
 	if (unlikely(!inet_ehash_secret))
 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
 			build_ehash_secret();
@@ -325,7 +355,7 @@ lookup_protocol:
 	}
 
 	err = -EPERM;
-	if (answer->capability > 0 && !capable(answer->capability))
+	if (answer->capability > 0 && !current_has_cap(answer->capability))
 		goto out_rcu_unlock;
 
 	err = -EAFNOSUPPORT;
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 9c8309ed35cf..c30f24bf2ccd 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -62,6 +62,10 @@
 #include <asm/system.h>
 #include <linux/mroute6.h>
 
+#ifdef CONFIG_ANDROID_PARANOID_NETWORK
+#include <linux/android_aid.h>
+#endif
+
 MODULE_AUTHOR("Cast of dozens");
 MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
 MODULE_LICENSE("GPL");
@@ -83,6 +87,29 @@ 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(int cap)
+{
+	if (cap == CAP_NET_RAW && in_egroup_p(AID_NET_RAW))
+		return 1;
+	return capable(cap);
+}
+# else
+static inline int current_has_network(void)
+{
+	return 1;
+}
+static inline int current_has_cap(int cap)
+{
+	return capable(cap);
+}
+#endif
+
 static int inet6_create(struct net *net, struct socket *sock, int protocol)
 {
 	struct inet_sock *inet;
@@ -95,6 +122,9 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol)
 	int try_loading_module = 0;
 	int err;
 
+	if (!current_has_network())
+		return -EACCES;
+
 	if (sock->type != SOCK_RAW &&
 	    sock->type != SOCK_DGRAM &&
 	    !inet_ehash_secret)
@@ -146,7 +176,7 @@ lookup_protocol:
 	}
 
 	err = -EPERM;
-	if (answer->capability > 0 && !capable(answer->capability))
+	if (answer->capability > 0 && !current_has_cap(answer->capability))
 		goto out_rcu_unlock;
 
 	sock->ops = answer->ops;