[apparmor] [patch 12/12] map the net permission set into a form compatible with the old dfa table

[john.johansen at canonical.com]

The old dfa table format has 2 64 bit permission field used to store
all of allow, quiet, audit, owner/!owner and transition mask. This leaves
7 bits for entry + a few other special bits.

Since policydb entries when using old style dfa permission format
don't use support the !owner permission entries we can map, the
high net work permission bits to these entries.

This allows us to enforce base network permissions on system with
only support for the old dfa table format.

Signed-off-by: John Johansen <john.johansen at canonical.com>
---
 parser/af_unix.cc |   30 +++++++++++++++++++-----------
 1 file changed, 19 insertions(+), 11 deletions(-)

--- 2.9-test.orig/parser/af_unix.cc
+++ 2.9-test/parser/af_unix.cc
@@ -216,6 +216,14 @@
 	}
 }
 
+static uint32_t map_perms(uint32_t mask)
+{
+	return (mask & 0x7f) |
+		((mask & (AA_NET_GETATTR | AA_NET_SETATTR)) << (AA_OTHER_SHIFT - 8)) |
+		((mask & (AA_NET_ACCEPT | AA_NET_BIND | AA_NET_LISTEN)) >> 4) | /* 2 + (AA_OTHER_SHIFT - 20) */
+		((mask & (AA_NET_SETOPT | AA_NET_GETOPT)) >> 5); /* 5 + (AA_OTHER_SHIFT - 24) */
+}
+
 int unix_rule::gen_policy_re(Profile &prof)
 {
 	std::ostringstream buffer, tmp;
@@ -258,8 +266,8 @@
 	if (mask & AA_NET_CREATE) {
 		buf = buffer.str();
 		if (!prof.policy.rules->add_rule(buf.c_str(), deny,
-						 AA_NET_CREATE,
-						 audit & AA_NET_CREATE,
+						 map_perms(AA_NET_CREATE),
+						 map_perms(audit & AA_NET_CREATE),
 						 dfaflags))
 			goto fail;
 		mask &= ~AA_NET_CREATE;
@@ -300,8 +308,8 @@
 		if (mask & AA_LOCAL_NET_PERMS & ~AA_LOCAL_NET_CMD) {
 			buf = buffer.str();
 			if (!prof.policy.rules->add_rule(buf.c_str(), deny,
-							 mask & AA_LOCAL_NET_PERMS & ~AA_LOCAL_NET_CMD,
-							 audit & AA_LOCAL_NET_PERMS & ~AA_LOCAL_NET_CMD,
+							 map_perms(mask & AA_LOCAL_NET_PERMS & ~AA_LOCAL_NET_CMD),
+							 map_perms(audit & AA_LOCAL_NET_PERMS & ~AA_LOCAL_NET_CMD),
 							 dfaflags))
 				goto fail;
 		}
@@ -312,8 +320,8 @@
 			tmp << "\\x" << std::setfill('0') << std::setw(2) << std::hex << CMD_ACCEPT;
 			buf = tmp.str();
 			if (!prof.policy.rules->add_rule(buf.c_str(), deny,
-							 AA_NET_ACCEPT,
-							 audit & AA_NET_ACCEPT,
+							 map_perms(AA_NET_ACCEPT),
+							 map_perms(audit & AA_NET_ACCEPT),
 							 dfaflags))
 				goto fail;
 		}
@@ -324,8 +332,8 @@
 			tmp << "..";
 			buf = tmp.str();
 			if (!prof.policy.rules->add_rule(buf.c_str(), deny,
-							 AA_NET_LISTEN,
-							 audit & AA_NET_LISTEN,
+							 map_perms(AA_NET_LISTEN),
+							 map_perms(audit & AA_NET_LISTEN),
 							 dfaflags))
 				goto fail;
 		}
@@ -336,8 +344,8 @@
 			tmp << "..";
 			buf = tmp.str();
 			if (!prof.policy.rules->add_rule(buf.c_str(), deny,
-							 AA_NET_OPT,
-							 audit & AA_NET_OPT,
+							 map_perms(AA_NET_OPT),
+							 map_perms(audit & AA_NET_OPT),
 							 dfaflags))
 				goto fail;
 		}
@@ -375,7 +383,7 @@
 		}
 
 		buf = buffer.str();
-		if (!prof.policy.rules->add_rule(buf.c_str(), deny, mode & AA_PEER_NET_PERMS, audit, dfaflags))
+		if (!prof.policy.rules->add_rule(buf.c_str(), deny, map_perms(mode & AA_PEER_NET_PERMS), map_perms(audit), dfaflags))
 			goto fail;
 	}