selinux: generate flask headers during kernel build

Add a simple utility (scripts/selinux/genheaders) and invoke it to
generate the kernel-private class and permission indices in flask.h
and av_permissions.h automatically during the kernel build from the
security class mapping definitions in classmap.h.  Adding new kernel
classes and permissions can then be done just by adding them to classmap.h.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

3 files changed, 125 insertions, 2 deletions

diff --git a/scripts/selinux/Makefile b/scripts/selinux/Makefile
index ca4b1ec01822..e8049da1831f 100644
--- a/scripts/selinux/Makefile
+++ b/scripts/selinux/Makefile
@@ -1,2 +1,2 @@
-subdir-y := mdp
-subdir- += mdp
+subdir-y := mdp genheaders
+subdir- += mdp genheaders
diff --git a/scripts/selinux/genheaders/Makefile b/scripts/selinux/genheaders/Makefile
new file mode 100644
index 000000000000..417b165008ee
--- /dev/null
+++ b/scripts/selinux/genheaders/Makefile
@@ -0,0 +1,5 @@
+hostprogs-y     := genheaders
+HOST_EXTRACFLAGS += -Isecurity/selinux/include
+
+always          := $(hostprogs-y)
+clean-files     := $(hostprogs-y)
diff --git a/scripts/selinux/genheaders/genheaders.c b/scripts/selinux/genheaders/genheaders.c
new file mode 100644
index 000000000000..3b16145dabe3
--- /dev/null
+++ b/scripts/selinux/genheaders/genheaders.c
@@ -0,0 +1,118 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <ctype.h>
+
+struct security_class_mapping {
+        const char *name;
+        const char *perms[sizeof(unsigned) * 8 + 1];
+};
+
+#include "classmap.h"
+#include "initial_sid_to_string.h"
+
+#define max(x, y) ((x > y) ? x : y)
+
+const char *progname;
+
+void usage(void)
+{
+        printf("usage: %s flask.h av_permissions.h\n", progname);
+        exit(1);
+}
+
+char *stoupperx(const char *s)
+{
+        char *s2 = strdup(s);
+        char *p;
+
+        if (!s2) {
+                fprintf(stderr, "%s:  out of memory\n", progname);
+                exit(3);
+        }
+
+        for (p = s2; *p; p++)
+                *p = toupper(*p);
+        return s2;
+}
+
+int main(int argc, char *argv[])
+{
+        int i, j, k;
+        int isids_len;
+        FILE *fout;
+
+        progname = argv[0];
+
+        if (argc < 3)
+                usage();
+
+        fout = fopen(argv[1], "w");
+        if (!fout) {
+                fprintf(stderr, "Could not open %s for writing:  %s\n",
+                        argv[1], strerror(errno));
+                exit(2);
+        }
+
+        for (i = 0; secclass_map[i].name; i++) {
+                struct security_class_mapping *map = &secclass_map[i];
+                map->name = stoupperx(map->name);
+                for (j = 0; map->perms[j]; j++)
+                        map->perms[j] = stoupperx(map->perms[j]);
+        }
+
+        isids_len = sizeof(initial_sid_to_string) / sizeof (char *);
+        for (i = 1; i < isids_len; i++)
+                initial_sid_to_string[i] = stoupperx(initial_sid_to_string[i]);
+
+        fprintf(fout, "/* This file is automatically generated.  Do not edit. */\n");
+        fprintf(fout, "#ifndef _SELINUX_FLASK_H_\n#define _SELINUX_FLASK_H_\n\n");
+
+        for (i = 0; secclass_map[i].name; i++) {
+                struct security_class_mapping *map = &secclass_map[i];
+                fprintf(fout, "#define SECCLASS_%s", map->name);
+                for (j = 0; j < max(1, 40 - strlen(map->name)); j++)
+                        fprintf(fout, " ");
+                fprintf(fout, "%2d\n", i+1);
+        }
+
+        fprintf(fout, "\n");
+
+        for (i = 1; i < isids_len; i++) {
+                char *s = initial_sid_to_string[i];
+                fprintf(fout, "#define SECINITSID_%s", s);
+                for (j = 0; j < max(1, 40 - strlen(s)); j++)
+                        fprintf(fout, " ");
+                fprintf(fout, "%2d\n", i);
+        }
+        fprintf(fout, "\n#define SECINITSID_NUM %d\n", i-1);
+        fprintf(fout, "\n#endif\n");
+        fclose(fout);
+
+        fout = fopen(argv[2], "w");
+        if (!fout) {
+                fprintf(stderr, "Could not open %s for writing:  %s\n",
+                        argv[2], strerror(errno));
+                exit(4);
+        }
+
+        fprintf(fout, "/* This file is automatically generated.  Do not edit. */\n");
+        fprintf(fout, "#ifndef _SELINUX_AV_PERMISSIONS_H_\n#define _SELINUX_AV_PERMISSIONS_H_\n\n");
+
+        for (i = 0; secclass_map[i].name; i++) {
+                struct security_class_mapping *map = &secclass_map[i];
+                for (j = 0; map->perms[j]; j++) {
+                        fprintf(fout, "#define %s__%s", map->name,
+                                map->perms[j]);
+                        for (k = 0; k < max(1, 40 - strlen(map->name) - strlen(map->perms[j])); k++)
+                                fprintf(fout, " ");
+                        fprintf(fout, "0x%08xUL\n", (1<<j));
+                }
+        }
+
+        fprintf(fout, "\n#endif\n");
+        fclose(fout);
+        exit(0);
+}