sepolgen: better analysis of why things broke

combine analysys of audit2why into audit2allow, so users can see if a
boolean would solve an AVC or if it is a constrain violation.  Rather
then blindly adding allow rules to modules.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Dan Walsh <dwalsh@redhat.com>

sepolgen/src/sepolgen/audit.py

@@ -127,6 +127,9 @@ class PathMessage(AuditMessage):
             if fields[0] == "path":
                 self.path = fields[1][1:-1]
                 return
+import selinux.audit2why as audit2why
+
+avcdict = {}
 
 class AVCMessage(AuditMessage):
     """AVC message representing an access denial or granted message.
@@ -168,6 +171,8 @@ class AVCMessage(AuditMessage):
         self.name = ""
         self.accesses = []
         self.denial = True
+        self.type = audit2why.TERULE
+        self.bools = []
 
     def __parse_access(self, recs, start):
         # This is kind of sucky - the access that is in a space separated
@@ -229,6 +234,30 @@ class AVCMessage(AuditMessage):
 
         if not found_src or not found_tgt or not found_class or not found_access:
             raise ValueError("AVC message in invalid format [%s]\n" % self.message)
+        self.analyze()
+
+    def analyze(self):
+        tcontext = self.tcontext.to_string()
+        scontext = self.scontext.to_string()
+        access_tuple = tuple( self.accesses)
+        if (scontext, tcontext, self.tclass, access_tuple) in avcdict.keys():
+            self.type, self.bools = avcdict[(scontext, tcontext, self.tclass, access_tuple)]
+        else:
+            self.type, self.bools = audit2why.analyze(scontext, tcontext, self.tclass, self.accesses);
+            if self.type == audit2why.NOPOLICY:
+                self.type = audit2why.TERULE
+            if self.type == audit2why.BADTCON:
+                raise ValueError("Invalid Target Context %s\n" % tcontext)
+            if self.type == audit2why.BADSCON:
+                raise ValueError("Invalid Source Context %s\n" % scontext)
+            if self.type == audit2why.BADSCON:
+                raise ValueError("Invalid Type Class %s\n" % self.tclass)
+            if self.type == audit2why.BADPERM:
+                raise ValueError("Invalid permission %s\n" % " ".join(self.accesses))
+            if self.type == audit2why.BADCOMPUTE:
+                raise ValueError("Error during access vector computation")
+
+            avcdict[(scontext, tcontext, self.tclass, access_tuple)] = (self.type, self.bools)
 
 class PolicyLoadMessage(AuditMessage):
     """Audit message indicating that the policy was reloaded."""
@@ -472,10 +501,10 @@ class AuditParser:
             if avc_filter:
                 if avc_filter.filter(avc):
                     av_set.add(avc.scontext.type, avc.tcontext.type, avc.tclass,
-                               avc.accesses, avc)
+                               avc.accesses, avc, avc_type=avc.type, bools=avc.bools)
             else:
                 av_set.add(avc.scontext.type, avc.tcontext.type, avc.tclass,
-                           avc.accesses, avc)
+                           avc.accesses, avc, avc_type=avc.type, bools=avc.bools)
         return av_set
 
 class AVCTypeFilter:

sepolgen/src/sepolgen/policygen.py

@@ -29,6 +29,8 @@ import objectmodel
 import access
 import interfaces
 import matching
+import selinux.audit2why as audit2why
+from setools import *
 
 # Constants for the level of explanation from the generation
 # routines
@@ -77,6 +79,7 @@ class PolicyGenerator:
 
         self.dontaudit = False
 
+        self.domains = None
     def set_gen_refpol(self, if_set=None, perm_maps=None):
         """Set whether reference policy interfaces are generated.
 
@@ -151,8 +154,41 @@ class PolicyGenerator:
             rule = refpolicy.AVRule(av)
             if self.dontaudit:
                 rule.rule_type = rule.DONTAUDIT
+            rule.comment = ""
             if self.explain:
-                rule.comment = refpolicy.Comment(explain_access(av, verbosity=self.explain))
+                rule.comment = str(refpolicy.Comment(explain_access(av, verbosity=self.explain)))
+            if av.type == audit2why.ALLOW:
+                rule.comment += "#!!!! This avc is allowed in the current policy\n"
+            if av.type == audit2why.DONTAUDIT:
+                rule.comment += "#!!!! This avc has a dontaudit rule in the current policy\n"
+
+            if av.type == audit2why.BOOLEAN:
+                if len(av.bools) > 1:
+                    rule.comment += "#!!!! This avc can be allowed using one of the these booleans:\n#     %s\n" % ", ".join(map(lambda x: x[0], av.bools))
+                else:
+                    rule.comment += "#!!!! This avc can be allowed using the boolean '%s'\n" % av.bools[0][0]
+
+            if av.type == audit2why.CONSTRAINT:
+                rule.comment += "#!!!! This avc is a constraint violation.  You will need to add an attribute to either the source or target type to make it work.\n"
+                rule.comment += "#Constraint rule: "
+
+            if av.type == audit2why.TERULE:
+                if "write" in av.perms:
+                    if "dir" in av.obj_class or "open" in av.perms:
+                        if not self.domains:
+                            self.domains = seinfo(ATTRIBUTE, name="domain")[0]["types"]
+                        types=[]
+
+                        try:
+                            for i in map(lambda x: x[TCONTEXT], sesearch([ALLOW], {SCONTEXT: av.src_type, CLASS: av.obj_class, PERMS: av.perms})):
+                                if i not in self.domains:
+                                    types.append(i)
+                            if len(types) == 1:
+                                rule.comment += "#!!!! The source type '%s' can write to a '%s' of the following type:\n# %s\n" % ( av.src_type, av.obj_class, ", ".join(types))
+                            elif len(types) >= 1:
+                                rule.comment += "#!!!! The source type '%s' can write to a '%s' of the following types:\n# %s\n" % ( av.src_type, av.obj_class, ", ".join(types))
+                        except:
+                            pass
             self.module.children.append(rule)