SELinux: add default_type statements

Because Fedora shipped userspace based on my development tree we now
have policy version 27 in the wild defining only default user, role, and
range.  Thus to add default_type we need a policy.28.

Signed-off-by: Eric Paris <eparis@redhat.com>

3 files changed, 31 insertions, 5 deletions

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 2bb9c2fd5f1a..9cd9b7c661ec 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -138,6 +138,11 @@ static struct policydb_compat_info policydb_compat[] = {
                 .sym_num        = SYM_NUM,
                 .ocon_num       = OCON_NUM,
         },
+        {
+                .version        = POLICYDB_VERSION_DEFAULT_TYPE,
+                .sym_num        = SYM_NUM,
+                .ocon_num       = OCON_NUM,
+        },
 };
 
 static struct policydb_compat_info *policydb_lookup_compat(int version)
@@ -1321,6 +1326,13 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp)
                 cladatum->default_range = le32_to_cpu(buf[2]);
         }
 
+        if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
+                rc = next_entry(buf, fp, sizeof(u32) * 1);
+                if (rc)
+                        goto bad;
+                cladatum->default_type = le32_to_cpu(buf[0]);
+        }
+
         rc = hashtab_insert(h, key, cladatum);
         if (rc)
                 goto bad;
@@ -2857,6 +2869,13 @@ static int class_write(void *vkey, void *datum, void *ptr)
                         return rc;
         }
 
+        if (p->policyvers >= POLICYDB_VERSION_DEFAULT_TYPE) {
+                buf[0] = cpu_to_le32(cladatum->default_type);
+                rc = put_entry(buf, sizeof(uint32_t), 1, fp);
+                if (rc)
+                        return rc;
+        }
+
         return 0;
 }
 
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index a949f1ad43bb..da637471d4ce 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -60,11 +60,12 @@ struct class_datum {
         struct symtab permissions;      /* class-specific permission symbol table */
         struct constraint_node *constraints;    /* constraints on class permissions */
         struct constraint_node *validatetrans;  /* special transition rules */
-        /* Options how a new object user and role should be decided */
+/* Options how a new object user, role, and type should be decided */
 #define DEFAULT_SOURCE         1
 #define DEFAULT_TARGET         2
         char default_user;
         char default_role;
+        char default_type;
 /* Options how a new object range should be decided */
 #define DEFAULT_SOURCE_LOW     1
 #define DEFAULT_SOURCE_HIGH    2
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 2ea108c2c048..1ded0ec7e8c2 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1472,12 +1472,18 @@ static int security_compute_sid(u32 ssid,
         }
 
         /* Set the type to default values. */
-        if ((tclass == policydb.process_class) || (sock == true)) {
-                /* Use the type of process. */
+        if (cladatum && cladatum->default_type == DEFAULT_SOURCE) {
                 newcontext.type = scontext->type;
-        } else {
-                /* Use the type of the related object. */
+        } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) {
                 newcontext.type = tcontext->type;
+        } else {
+                if ((tclass == policydb.process_class) || (sock == true)) {
+                        /* Use the type of process. */
+                        newcontext.type = scontext->type;
+                } else {
+                        /* Use the type of the related object. */
+                        newcontext.type = tcontext->type;
+                }
         }
 
         /* Look for a type transition/member/change rule. */