Added 'zero' command to wipe partition tables and superblocks.

6 files changed, 133 insertions, 3 deletions

diff --git a/src/generator.ml b/src/generator.ml
index 615d32ec..8d5450d1 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -1633,8 +1633,13 @@ This returns the ext2/3/4 filesystem UUID of the filesystem on
 C<device>.");
 
   ("fsck", (RInt "status", [String "fstype"; String "device"]), 84, [],
-   [InitBasicFS, TestRun (
-      [["fsck"; "ext2"; "/dev/sda1"]])],
+   [InitBasicFS, TestOutputInt (
+      [["umount"; "/dev/sda1"];
+       ["fsck"; "ext2"; "/dev/sda1"]], 0);
+    InitBasicFS, TestOutputInt (
+      [["umount"; "/dev/sda1"];
+       ["zero"; "/dev/sda1"];
+       ["fsck"; "ext2"; "/dev/sda1"]], 8)],
    "run the filesystem checker",
    "\
 This runs the filesystem checker (fsck) on C<device> which
@@ -1647,6 +1652,21 @@ status codes can be summed together.
 It is entirely equivalent to running C<fsck -a -t fstype device>.
 Note that checking or repairing NTFS volumes is not supported
 (by linux-ntfs).");
+
+  ("zero", (RErr, [String "device"]), 85, [],
+   [InitBasicFS, TestOutput (
+      [["umount"; "/dev/sda1"];
+       ["zero"; "/dev/sda1"];
+       ["file"; "/dev/sda1"]], "data")],
+   "write zeroes to the device",
+   "\
+This command writes zeroes over the first few blocks of C<device>.
+
+How many blocks are zeroed isn't specified (but it's I<not> enough
+to securely wipe the device).  It should be sufficient to remove
+any partition tables, filesystem superblocks and so on.");
+
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
diff --git a/src/guestfs-actions.c b/src/guestfs-actions.c
index a075b802..e2da1c3a 100644
--- a/src/guestfs-actions.c
+++ b/src/guestfs-actions.c
@@ -7642,3 +7642,89 @@ int guestfs_fsck (guestfs_h *g,
   return ctx.ret.status;
 }
 
+struct zero_ctx {
+  /* This flag is set by the callbacks, so we know we've done
+   * the callbacks as expected, and in the right sequence.
+   * 0 = not called, 1 = reply_cb called.
+   */
+  int cb_sequence;
+  struct guestfs_message_header hdr;
+  struct guestfs_message_error err;
+};
+
+static void zero_reply_cb (guestfs_h *g, void *data, XDR *xdr)
+{
+  guestfs_main_loop *ml = guestfs_get_main_loop (g);
+  struct zero_ctx *ctx = (struct zero_ctx *) data;
+
+  /* This should definitely not happen. */
+  if (ctx->cb_sequence != 0) {
+    ctx->cb_sequence = 9999;
+    error (g, "%s: internal error: reply callback called twice", "guestfs_zero");
+    return;
+  }
+
+  ml->main_loop_quit (ml, g);
+
+  if (!xdr_guestfs_message_header (xdr, &ctx->hdr)) {
+    error (g, "%s: failed to parse reply header", "guestfs_zero");
+    return;
+  }
+  if (ctx->hdr.status == GUESTFS_STATUS_ERROR) {
+    if (!xdr_guestfs_message_error (xdr, &ctx->err)) {
+      error (g, "%s: failed to parse reply error", "guestfs_zero");
+      return;
+    }
+    goto done;
+  }
+ done:
+  ctx->cb_sequence = 1;
+}
+
+int guestfs_zero (guestfs_h *g,
+		const char *device)
+{
+  struct guestfs_zero_args args;
+  struct zero_ctx ctx;
+  guestfs_main_loop *ml = guestfs_get_main_loop (g);
+  int serial;
+
+  if (check_state (g, "guestfs_zero") == -1) return -1;
+  guestfs_set_busy (g);
+
+  memset (&ctx, 0, sizeof ctx);
+
+  args.device = (char *) device;
+  serial = guestfs__send_sync (g, GUESTFS_PROC_ZERO,
+        (xdrproc_t) xdr_guestfs_zero_args, (char *) &args);
+  if (serial == -1) {
+    guestfs_set_ready (g);
+    return -1;
+  }
+
+  guestfs__switch_to_receiving (g);
+  ctx.cb_sequence = 0;
+  guestfs_set_reply_callback (g, zero_reply_cb, &ctx);
+  (void) ml->main_loop_run (ml, g);
+  guestfs_set_reply_callback (g, NULL, NULL);
+  if (ctx.cb_sequence != 1) {
+    error (g, "%s reply failed, see earlier error messages", "guestfs_zero");
+    guestfs_set_ready (g);
+    return -1;
+  }
+
+  if (check_reply_header (g, &ctx.hdr, GUESTFS_PROC_ZERO, serial) == -1) {
+    guestfs_set_ready (g);
+    return -1;
+  }
+
+  if (ctx.hdr.status == GUESTFS_STATUS_ERROR) {
+    error (g, "%s", ctx.err.error_message);
+    guestfs_set_ready (g);
+    return -1;
+  }
+
+  guestfs_set_ready (g);
+  return 0;
+}
+
diff --git a/src/guestfs-actions.h b/src/guestfs-actions.h
index 6e56099a..0fc62a18 100644
--- a/src/guestfs-actions.h
+++ b/src/guestfs-actions.h
@@ -124,3 +124,4 @@ extern char *guestfs_get_e2label (guestfs_h *handle, const char *device);
 extern int guestfs_set_e2uuid (guestfs_h *handle, const char *device, const char *uuid);
 extern char *guestfs_get_e2uuid (guestfs_h *handle, const char *device);
 extern int guestfs_fsck (guestfs_h *handle, const char *fstype, const char *device);
+extern int guestfs_zero (guestfs_h *handle, const char *device);
diff --git a/src/guestfs_protocol.c b/src/guestfs_protocol.c
index 16e80f17..b12133a0 100644
--- a/src/guestfs_protocol.c
+++ b/src/guestfs_protocol.c
@@ -1450,6 +1450,16 @@ xdr_guestfs_fsck_ret (XDR *xdrs, guestfs_fsck_ret *objp)
 }
 
 bool_t
+xdr_guestfs_zero_args (XDR *xdrs, guestfs_zero_args *objp)
+{
+	register int32_t *buf;
+
+	 if (!xdr_string (xdrs, &objp->device, ~0))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
 xdr_guestfs_procedure (XDR *xdrs, guestfs_procedure *objp)
 {
 	register int32_t *buf;
diff --git a/src/guestfs_protocol.h b/src/guestfs_protocol.h
index 64e4b4db..2e79669c 100644
--- a/src/guestfs_protocol.h
+++ b/src/guestfs_protocol.h
@@ -750,6 +750,11 @@ struct guestfs_fsck_ret {
 };
 typedef struct guestfs_fsck_ret guestfs_fsck_ret;
 
+struct guestfs_zero_args {
+	char *device;
+};
+typedef struct guestfs_zero_args guestfs_zero_args;
+
 enum guestfs_procedure {
 	GUESTFS_PROC_MOUNT = 1,
 	GUESTFS_PROC_SYNC = 2,
@@ -835,7 +840,8 @@ enum guestfs_procedure {
 	GUESTFS_PROC_SET_E2UUID = 82,
 	GUESTFS_PROC_GET_E2UUID = 83,
 	GUESTFS_PROC_FSCK = 84,
-	GUESTFS_PROC_NR_PROCS = 84 + 1,
+	GUESTFS_PROC_ZERO = 85,
+	GUESTFS_PROC_NR_PROCS = 85 + 1,
 };
 typedef enum guestfs_procedure guestfs_procedure;
 #define GUESTFS_MESSAGE_MAX 4194304
@@ -1002,6 +1008,7 @@ extern  bool_t xdr_guestfs_get_e2uuid_args (XDR *, guestfs_get_e2uuid_args*);
 extern  bool_t xdr_guestfs_get_e2uuid_ret (XDR *, guestfs_get_e2uuid_ret*);
 extern  bool_t xdr_guestfs_fsck_args (XDR *, guestfs_fsck_args*);
 extern  bool_t xdr_guestfs_fsck_ret (XDR *, guestfs_fsck_ret*);
+extern  bool_t xdr_guestfs_zero_args (XDR *, guestfs_zero_args*);
 extern  bool_t xdr_guestfs_procedure (XDR *, guestfs_procedure*);
 extern  bool_t xdr_guestfs_message_direction (XDR *, guestfs_message_direction*);
 extern  bool_t xdr_guestfs_message_status (XDR *, guestfs_message_status*);
@@ -1127,6 +1134,7 @@ extern bool_t xdr_guestfs_get_e2uuid_args ();
 extern bool_t xdr_guestfs_get_e2uuid_ret ();
 extern bool_t xdr_guestfs_fsck_args ();
 extern bool_t xdr_guestfs_fsck_ret ();
+extern bool_t xdr_guestfs_zero_args ();
 extern bool_t xdr_guestfs_procedure ();
 extern bool_t xdr_guestfs_message_direction ();
 extern bool_t xdr_guestfs_message_status ();
diff --git a/src/guestfs_protocol.x b/src/guestfs_protocol.x
index 92dc8eac..c940bf44 100644
--- a/src/guestfs_protocol.x
+++ b/src/guestfs_protocol.x
@@ -582,6 +582,10 @@ struct guestfs_fsck_ret {
   int status;
 };
 
+struct guestfs_zero_args {
+  string device<>;
+};
+
 enum guestfs_procedure {
   GUESTFS_PROC_MOUNT = 1,
   GUESTFS_PROC_SYNC = 2,
@@ -667,6 +671,7 @@ enum guestfs_procedure {
   GUESTFS_PROC_SET_E2UUID = 82,
   GUESTFS_PROC_GET_E2UUID = 83,
   GUESTFS_PROC_FSCK = 84,
+  GUESTFS_PROC_ZERO = 85,
   GUESTFS_PROC_NR_PROCS
 };