SELinux: Auto-generate security_is_socket_class

The security_is_socket_class() is auto-generated by genheaders based
on classmap.h to reduce maintenance effort when a new class is defined
in SELinux kernel. The name for any socket class should be suffixed by
"socket" and doesn't contain more than one substr of "socket".

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/scripts/selinux/genheaders/genheaders.c b/scripts/selinux/genheaders/genheaders.c
index 58a12c2..539855f 100644
--- a/scripts/selinux/genheaders/genheaders.c
+++ b/scripts/selinux/genheaders/genheaders.c
@@ -43,6 +43,8 @@
 	int i, j, k;
 	int isids_len;
 	FILE *fout;
+	const char *needle = "SOCKET";
+	char *substr;
 
 	progname = argv[0];
 
@@ -88,6 +90,24 @@
 		fprintf(fout, "%2d\n", i);
 	}
 	fprintf(fout, "\n#define SECINITSID_NUM %d\n", i-1);
+	fprintf(fout, "\nstatic inline bool security_is_socket_class(u16 kern_tclass)\n");
+	fprintf(fout, "{\n");
+	fprintf(fout, "\tbool sock = false;\n\n");
+	fprintf(fout, "\tswitch (kern_tclass) {\n");
+	for (i = 0; secclass_map[i].name; i++) {
+		struct security_class_mapping *map = &secclass_map[i];
+		substr = strstr(map->name, needle);
+		if (substr && strcmp(substr, needle) == 0)
+			fprintf(fout, "\tcase SECCLASS_%s:\n", map->name);
+	}
+	fprintf(fout, "\t\tsock = true;\n");
+	fprintf(fout, "\t\tbreak;\n");
+	fprintf(fout, "\tdefault:\n");
+	fprintf(fout, "\t\tbreak;\n");
+	fprintf(fout, "\t}\n\n");
+	fprintf(fout, "\treturn sock;\n");
+	fprintf(fout, "}\n");
+
 	fprintf(fout, "\n#endif\n");
 	fclose(fout);
 
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 4227e5f..b8c5372 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -12,6 +12,10 @@
 #define COMMON_IPC_PERMS "create", "destroy", "getattr", "setattr", "read", \
 	    "write", "associate", "unix_read", "unix_write"
 
+/*
+ * Note: The name for any socket class should be suffixed by "socket",
+ *	 and doesn't contain more than one substr of "socket".
+ */
 struct security_class_mapping secclass_map[] = {
 	{ "security",
 	  { "compute_av", "compute_create", "compute_member",