apparmor: add base infastructure for socket mediation

Provide a basic mediation of sockets. This is not a full net mediation
but just whether a spcific family of socket can be used by an
application, along with setting up some basic infrastructure for
network mediation to follow.

the user space rule hav the basic form of
  NETWORK RULE = [ QUALIFIERS ] 'network' [ DOMAIN ]
                 [ TYPE | PROTOCOL ]

  DOMAIN = ( 'inet' | 'ax25' | 'ipx' | 'appletalk' | 'netrom' |
             'bridge' | 'atmpvc' | 'x25' | 'inet6' | 'rose' |
	     'netbeui' | 'security' | 'key' | 'packet' | 'ash' |
	     'econet' | 'atmsvc' | 'sna' | 'irda' | 'pppox' |
	     'wanpipe' | 'bluetooth' | 'netlink' | 'unix' | 'rds' |
	     'llc' | 'can' | 'tipc' | 'iucv' | 'rxrpc' | 'isdn' |
	     'phonet' | 'ieee802154' | 'caif' | 'alg' | 'nfc' |
	     'vsock' | 'mpls' | 'ib' | 'kcm' ) ','

  TYPE = ( 'stream' | 'dgram' | 'seqpacket' |  'rdm' | 'raw' |
           'packet' )

  PROTOCOL = ( 'tcp' | 'udp' | 'icmp' )

eg.
  network,
  network inet,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

1 files changed, 46 insertions, 1 deletions

diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 4ede87c30f8b..5a2aec358322 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -275,6 +275,19 @@ fail:
 	return 0;
 }
 
+static bool unpack_u16(struct aa_ext *e, u16 *data, const char *name)
+{
+	if (unpack_nameX(e, AA_U16, name)) {
+		if (!inbounds(e, sizeof(u16)))
+			return 0;
+		if (data)
+			*data = le16_to_cpu(get_unaligned((__le16 *) e->pos));
+		e->pos += sizeof(u16);
+		return 1;
+	}
+	return 0;
+}
+
 static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
 {
 	if (unpack_nameX(e, AA_U32, name)) {
@@ -584,7 +597,7 @@ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
 	struct aa_profile *profile = NULL;
 	const char *tmpname, *tmpns = NULL, *name = NULL;
 	const char *info = "failed to unpack profile";
-	size_t ns_len;
+	size_t size = 0, ns_len;
 	struct rhashtable_params params = { 0 };
 	char *key = NULL;
 	struct aa_data *data;
@@ -717,6 +730,38 @@ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name)
 		goto fail;
 	}
 
+	size = unpack_array(e, "net_allowed_af");
+	if (size) {
+
+		for (i = 0; i < size; i++) {
+			/* discard extraneous rules that this kernel will
+			 * never request
+			 */
+			if (i >= AF_MAX) {
+				u16 tmp;
+
+				if (!unpack_u16(e, &tmp, NULL) ||
+				    !unpack_u16(e, &tmp, NULL) ||
+				    !unpack_u16(e, &tmp, NULL))
+					goto fail;
+				continue;
+			}
+			if (!unpack_u16(e, &profile->net.allow[i], NULL))
+				goto fail;
+			if (!unpack_u16(e, &profile->net.audit[i], NULL))
+				goto fail;
+			if (!unpack_u16(e, &profile->net.quiet[i], NULL))
+				goto fail;
+		}
+		if (!unpack_nameX(e, AA_ARRAYEND, NULL))
+			goto fail;
+	}
+	if (VERSION_LT(e->version, v7)) {
+		/* pre v7 policy always allowed these */
+		profile->net.allow[AF_UNIX] = 0xffff;
+		profile->net.allow[AF_NETLINK] = 0xffff;
+	}
+
 	if (unpack_nameX(e, AA_STRUCT, "policydb")) {
 		/* generic policy dfa - optional and may be NULL */
 		info = "failed to unpack policydb";