Revert "Revert "Adding e4crypt support""

Fix build break caused by original change

This reverts commit 84b0bab58fcc7f225e9a17a15c531b0c2fc509c5.

Change-Id: I99fbd7c3d1ed92db1f546033c8493bb71a327924

4 files changed, 102 insertions, 27 deletions

diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index d4daed6..273a2ec 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -31,6 +31,7 @@
 #include <dirent.h>
 #include <ext4.h>
 #include <ext4_sb.h>
+#include <ext4_crypt.h>
 
 #include <linux/loop.h>
 #include <private/android_filesystem_config.h>
@@ -428,6 +429,73 @@ out:
     return ret;
 }
 
+// Check to see if a mountable volume has encryption requirements
+static int handle_encryptable(struct fstab *fstab, const struct fstab_rec* rec)
+{
+    /* If this is block encryptable, need to trigger encryption */
+    if (   (rec->fs_mgr_flags & MF_FORCECRYPT)
+        || (device_is_force_encrypted() && fs_mgr_is_encryptable(rec))) {
+        if (umount(rec->mount_point) == 0) {
+            return FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION;
+        } else {
+            WARNING("Could not umount %s (%s) - allow continue unencrypted\n",
+                    rec->mount_point, strerror(errno));
+            return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
+        }
+    }
+
+    // Deal with file level encryption
+    if (rec->fs_mgr_flags & MF_FILEENCRYPTION) {
+        // Default or not yet initialized encryption requires no more work here
+        if (!e4crypt_non_default_key(rec->mount_point)) {
+            INFO("%s is default file encrypted\n", rec->mount_point);
+            return FS_MGR_MNTALL_DEV_DEFAULT_FILE_ENCRYPTED;
+        }
+
+        INFO("%s is non-default file encrypted\n", rec->mount_point);
+
+        // Uses non-default key, so must unmount and set up temp file system
+        if (umount(rec->mount_point)) {
+            ERROR("Failed to umount %s - rebooting\n", rec->mount_point);
+            return FS_MGR_MNTALL_FAIL;
+        }
+
+        if (fs_mgr_do_tmpfs_mount(rec->mount_point) != 0) {
+            ERROR("Failed to mount a tmpfs at %s\n", rec->mount_point);
+            return FS_MGR_MNTALL_FAIL;
+        }
+
+        // Mount data temporarily so we can access unencrypted dir
+        char tmp_mnt[PATH_MAX];
+        strlcpy(tmp_mnt, rec->mount_point, sizeof(tmp_mnt));
+        strlcat(tmp_mnt, "/tmp_mnt", sizeof(tmp_mnt));
+        if (mkdir(tmp_mnt, 0700)) {
+            ERROR("Failed to create temp mount point\n");
+            return FS_MGR_MNTALL_FAIL;
+        }
+
+        if (fs_mgr_do_mount(fstab, rec->mount_point,
+                            rec->blk_device, tmp_mnt)) {
+            ERROR("Error temp mounting encrypted file system\n");
+            return FS_MGR_MNTALL_FAIL;
+        }
+
+        // Link it to the normal place so ext4_crypt functions work normally
+        strlcat(tmp_mnt, "/unencrypted", sizeof(tmp_mnt));
+        char link_path[PATH_MAX];
+        strlcpy(link_path, rec->mount_point, sizeof(link_path));
+        strlcat(link_path, "/unencrypted", sizeof(link_path));
+        if (symlink(tmp_mnt, link_path)) {
+            ERROR("Error creating symlink to unencrypted directory\n");
+            return FS_MGR_MNTALL_FAIL;
+        }
+
+        return FS_MGR_MNTALL_DEV_NON_DEFAULT_FILE_ENCRYPTED;
+    }
+
+    return FS_MGR_MNTALL_DEV_NOT_ENCRYPTED;
+}
+
 /* When multiple fstab records share the same mount_point, it will
  * try to mount each one in turn, and ignore any duplicates after a
  * first successful mount.
@@ -490,25 +558,21 @@ int fs_mgr_mount_all(struct fstab *fstab)
 
         /* Deal with encryptability. */
         if (!mret) {
-            /* If this is encryptable, need to trigger encryption */
-            if (   (fstab->recs[attempted_idx].fs_mgr_flags & MF_FORCECRYPT)
-                || (device_is_force_encrypted()
-                    && fs_mgr_is_encryptable(&fstab->recs[attempted_idx]))) {
-                if (umount(fstab->recs[attempted_idx].mount_point) == 0) {
-                    if (encryptable == FS_MGR_MNTALL_DEV_NOT_ENCRYPTED) {
-                        ERROR("Will try to encrypt %s %s\n", fstab->recs[attempted_idx].mount_point,
-                              fstab->recs[attempted_idx].fs_type);
-                        encryptable = FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION;
-                    } else {
-                        ERROR("Only one encryptable/encrypted partition supported\n");
-                        encryptable = FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED;
-                    }
-                } else {
-                    WARNING("Could not umount %s (%s) - allow continue unencrypted\n",
-                            fstab->recs[attempted_idx].mount_point, strerror(errno));
-                    continue;
+            int status = handle_encryptable(fstab, &fstab->recs[attempted_idx]);
+
+            if (status == FS_MGR_MNTALL_FAIL) {
+                /* Fatal error - no point continuing */
+                return status;
+            }
+
+            if (status != FS_MGR_MNTALL_DEV_NOT_ENCRYPTED) {
+                if (encryptable != FS_MGR_MNTALL_DEV_NOT_ENCRYPTED) {
+                    // Log and continue
+                    ERROR("Only one encryptable/encrypted partition supported\n");
                 }
+                encryptable = status;
             }
+
             /* Success!  Go get the next one */
             continue;
         }
diff --git a/fs_mgr/fs_mgr_fstab.c b/fs_mgr/fs_mgr_fstab.c
index 2c3c90d..8b0f714 100644
--- a/fs_mgr/fs_mgr_fstab.c
+++ b/fs_mgr/fs_mgr_fstab.c
@@ -61,6 +61,7 @@ static struct flag_list fs_mgr_flags[] = {
     { "check",       MF_CHECK },
     { "encryptable=",MF_CRYPT },
     { "forceencrypt=",MF_FORCECRYPT },
+    { "fileencryption",MF_FILEENCRYPTION },
     { "nonremovable",MF_NONREMOVABLE },
     { "voldmanaged=",MF_VOLDMANAGED},
     { "length=",     MF_LENGTH },
@@ -418,27 +419,32 @@ struct fstab_rec *fs_mgr_get_entry_for_mount_point(struct fstab *fstab, const ch
     return fs_mgr_get_entry_for_mount_point_after(NULL, fstab, path);
 }
 
-int fs_mgr_is_voldmanaged(struct fstab_rec *fstab)
+int fs_mgr_is_voldmanaged(const struct fstab_rec *fstab)
 {
     return fstab->fs_mgr_flags & MF_VOLDMANAGED;
 }
 
-int fs_mgr_is_nonremovable(struct fstab_rec *fstab)
+int fs_mgr_is_nonremovable(const struct fstab_rec *fstab)
 {
     return fstab->fs_mgr_flags & MF_NONREMOVABLE;
 }
 
-int fs_mgr_is_verified(struct fstab_rec *fstab)
+int fs_mgr_is_verified(const struct fstab_rec *fstab)
 {
     return fstab->fs_mgr_flags & MF_VERIFY;
 }
 
-int fs_mgr_is_encryptable(struct fstab_rec *fstab)
+int fs_mgr_is_encryptable(const struct fstab_rec *fstab)
 {
     return fstab->fs_mgr_flags & (MF_CRYPT | MF_FORCECRYPT);
 }
 
-int fs_mgr_is_noemulatedsd(struct fstab_rec *fstab)
+int fs_mgr_is_file_encrypted(const struct fstab_rec *fstab)
+{
+    return fstab->fs_mgr_flags & MF_FILEENCRYPTION;
+}
+
+int fs_mgr_is_noemulatedsd(const struct fstab_rec *fstab)
 {
     return fstab->fs_mgr_flags & MF_NOEMULATEDSD;
 }
diff --git a/fs_mgr/fs_mgr_priv.h b/fs_mgr/fs_mgr_priv.h
index 88a1040..d56111a 100644
--- a/fs_mgr/fs_mgr_priv.h
+++ b/fs_mgr/fs_mgr_priv.h
@@ -76,6 +76,7 @@
 #define MF_FORCECRYPT   0x400
 #define MF_NOEMULATEDSD 0x800 /* no emulated sdcard daemon, sd card is the only
                                  external storage */
+#define MF_FILEENCRYPTION 0x2000
 
 #define DM_BUF_SIZE 4096
 
diff --git a/fs_mgr/include/fs_mgr.h b/fs_mgr/include/fs_mgr.h
index ad8a8fc..b5e02f9 100644
--- a/fs_mgr/include/fs_mgr.h
+++ b/fs_mgr/include/fs_mgr.h
@@ -74,10 +74,13 @@ typedef void (*fs_mgr_verity_state_callback)(struct fstab_rec *fstab,
 struct fstab *fs_mgr_read_fstab(const char *fstab_path);
 void fs_mgr_free_fstab(struct fstab *fstab);
 
+#define FS_MGR_MNTALL_DEV_NON_DEFAULT_FILE_ENCRYPTED 5
+#define FS_MGR_MNTALL_DEV_DEFAULT_FILE_ENCRYPTED 4
 #define FS_MGR_MNTALL_DEV_NEEDS_RECOVERY 3
 #define FS_MGR_MNTALL_DEV_NEEDS_ENCRYPTION 2
 #define FS_MGR_MNTALL_DEV_MIGHT_BE_ENCRYPTED 1
 #define FS_MGR_MNTALL_DEV_NOT_ENCRYPTED 0
+#define FS_MGR_MNTALL_FAIL -1
 int fs_mgr_mount_all(struct fstab *fstab);
 
 #define FS_MGR_DOMNT_FAILED -1
@@ -94,11 +97,12 @@ int fs_mgr_add_entry(struct fstab *fstab,
                      const char *mount_point, const char *fs_type,
                      const char *blk_device);
 struct fstab_rec *fs_mgr_get_entry_for_mount_point(struct fstab *fstab, const char *path);
-int fs_mgr_is_voldmanaged(struct fstab_rec *fstab);
-int fs_mgr_is_nonremovable(struct fstab_rec *fstab);
-int fs_mgr_is_verified(struct fstab_rec *fstab);
-int fs_mgr_is_encryptable(struct fstab_rec *fstab);
-int fs_mgr_is_noemulatedsd(struct fstab_rec *fstab);
+int fs_mgr_is_voldmanaged(const struct fstab_rec *fstab);
+int fs_mgr_is_nonremovable(const struct fstab_rec *fstab);
+int fs_mgr_is_verified(const struct fstab_rec *fstab);
+int fs_mgr_is_encryptable(const struct fstab_rec *fstab);
+int fs_mgr_is_file_encrypted(const struct fstab_rec *fstab);
+int fs_mgr_is_noemulatedsd(const struct fstab_rec *fstab);
 int fs_mgr_swapon_all(struct fstab *fstab);
 #ifdef __cplusplus
 }