Extend recovery and updater to support setting file security contexts.

Extend minzip, recovery, and updater to set the security context on
files based on the file_contexts configuration included in the package.

Change-Id: Ied379f266a16c64f2b4dca15dc39b98fcce16f29

4 files changed, 65 insertions, 8 deletions

diff --git a/updater/Android.mk b/updater/Android.mk
index 2c51f99..f8ccb76 100644
--- a/updater/Android.mk
+++ b/updater/Android.mk
@@ -22,12 +22,13 @@ ifeq ($(TARGET_USERIMAGES_USE_EXT4), true)
 LOCAL_CFLAGS += -DUSE_EXT4
 LOCAL_C_INCLUDES += system/extras/ext4_utils
 LOCAL_STATIC_LIBRARIES += libext4_utils libz
+endif
+
 ifeq ($(HAVE_SELINUX), true)
 LOCAL_C_INCLUDES += external/libselinux/include
 LOCAL_STATIC_LIBRARIES += libselinux
 LOCAL_CFLAGS += -DHAVE_SELINUX
 endif # HAVE_SELINUX
-endif
 
 LOCAL_STATIC_LIBRARIES += $(TARGET_RECOVERY_UPDATER_LIBS) $(TARGET_RECOVERY_UPDATER_EXTRA_LIBS)
 LOCAL_STATIC_LIBRARIES += libapplypatch libedify libmtdutils libminzip libz
diff --git a/updater/install.c b/updater/install.c
index 7b4b99b..a59c4ed 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -79,8 +79,24 @@ Value* MountFn(const char* name, State* state, int argc, Expr* argv[]) {
         goto done;
     }
 
+#ifdef HAVE_SELINUX
+    char *secontext = NULL;
+
+    if (sehandle) {
+        selabel_lookup(sehandle, &secontext, mount_point, 0755);
+        setfscreatecon(secontext);
+    }
+#endif
+
     mkdir(mount_point, 0755);
 
+#ifdef HAVE_SELINUX
+    if (secontext) {
+        freecon(secontext);
+        setfscreatecon(NULL);
+    }
+#endif
+
     if (strcmp(partition_type, "MTD") == 0) {
         mtd_scan_partitions();
         const MtdPartition* mtd;
@@ -177,25 +193,34 @@ done:
 }
 
 
-// format(fs_type, partition_type, location, fs_size)
+// format(fs_type, partition_type, location, fs_size, mount_point)
 //
-//    fs_type="yaffs2" partition_type="MTD"     location=partition fs_size=<bytes>
-//    fs_type="ext4"   partition_type="EMMC"    location=device    fs_size=<bytes>
+//    fs_type="yaffs2" partition_type="MTD"     location=partition fs_size=<bytes> mount_point=<location>
+//    fs_type="ext4"   partition_type="EMMC"    location=device    fs_size=<bytes> mount_point=<location>
 //    if fs_size == 0, then make_ext4fs uses the entire partition.
 //    if fs_size > 0, that is the size to use
 //    if fs_size < 0, then reserve that many bytes at the end of the partition
+//    mount_point is used with SELinux as the location of the mount point, absent otherwise
 Value* FormatFn(const char* name, State* state, int argc, Expr* argv[]) {
     char* result = NULL;
-    if (argc != 4) {
-        return ErrorAbort(state, "%s() expects 4 args, got %d", name, argc);
+    if (argc != 4 && argc != 5) {
+        return ErrorAbort(state, "%s() expects 4 or 5 args, got %d", name, argc);
     }
     char* fs_type;
     char* partition_type;
     char* location;
     char* fs_size;
+    char* mount_point = NULL;
+
+#ifdef HAVE_SELINUX
+    if (ReadArgs(state, argv, 5, &fs_type, &partition_type, &location, &fs_size, &mount_point) < 0) {
+        return NULL;
+    }
+#else
     if (ReadArgs(state, argv, 4, &fs_type, &partition_type, &location, &fs_size) < 0) {
         return NULL;
     }
+#endif
 
     if (strlen(fs_type) == 0) {
         ErrorAbort(state, "fs_type argument to %s() can't be empty", name);
@@ -211,6 +236,13 @@ Value* FormatFn(const char* name, State* state, int argc, Expr* argv[]) {
         goto done;
     }
 
+#ifdef HAVE_SELINUX
+    if (!mount_point || strlen(mount_point) == 0) {
+        ErrorAbort(state, "mount_point argument to %s() can't be empty", name);
+        goto done;
+    }
+#endif
+
     if (strcmp(partition_type, "MTD") == 0) {
         mtd_scan_partitions();
         const MtdPartition* mtd = mtd_find_partition_by_name(location);
@@ -240,7 +272,7 @@ Value* FormatFn(const char* name, State* state, int argc, Expr* argv[]) {
         result = location;
 #ifdef USE_EXT4
     } else if (strcmp(fs_type, "ext4") == 0) {
-        int status = make_ext4fs(location, atoll(fs_size));
+        int status = make_ext4fs(location, atoll(fs_size), mount_point, sehandle);
         if (status != 0) {
             fprintf(stderr, "%s: make_ext4fs failed (%d) on %s",
                     name, status, location);
@@ -347,7 +379,7 @@ Value* PackageExtractDirFn(const char* name, State* state,
 
     bool success = mzExtractRecursive(za, zip_path, dest_path,
                                       MZ_EXTRACT_FILES_ONLY, &timestamp,
-                                      NULL, NULL);
+                                      NULL, NULL, sehandle);
     free(zip_path);
     free(dest_path);
     return StringValue(strdup(success ? "t" : ""));
diff --git a/updater/updater.c b/updater/updater.c
index aa626d2..5f15808 100644
--- a/updater/updater.c
+++ b/updater/updater.c
@@ -32,6 +32,8 @@
 // (Note it's "updateR-script", not the older "update-script".)
 #define SCRIPT_NAME "META-INF/com/google/android/updater-script"
 
+struct selabel_handle *sehandle;
+
 int main(int argc, char** argv) {
     // Various things log information to stdout or stderr more or less
     // at random.  The log file makes more sense if buffering is
@@ -103,6 +105,19 @@ int main(int argc, char** argv) {
         return 6;
     }
 
+#ifdef HAVE_SELINUX
+    struct selinux_opt seopts[] = {
+      { SELABEL_OPT_PATH, "/file_contexts" }
+    };
+
+    sehandle = selabel_open(SELABEL_CTX_FILE, seopts, 1);
+
+    if (!sehandle) {
+        fprintf(stderr, "Warning:  No file_contexts\n");
+        fprintf(cmd_pipe, "ui_print Warning: No file_contexts\n");
+    }
+#endif
+
     // Evaluate the parsed script.
 
     UpdaterInfo updater_info;
diff --git a/updater/updater.h b/updater/updater.h
index bd60dc1..a00872c 100644
--- a/updater/updater.h
+++ b/updater/updater.h
@@ -20,10 +20,19 @@
 #include <stdio.h>
 #include "minzip/Zip.h"
 
+#ifdef HAVE_SELINUX
+#include <selinux/selinux.h>
+#include <selinux/label.h>
+#else
+struct selabel_handle;
+#endif
+
 typedef struct {
     FILE* cmd_pipe;
     ZipArchive* package_zip;
     int version;
 } UpdaterInfo;
 
+extern struct selabel_handle *sehandle;
+
 #endif