blktap2: The tap-ctl userspace control utility and library.

Tapdisk control in userspace, a replacement for the original blktap2
control stack, which had to pass a kernel space interface based on
sysfs nodes.

All tapdisk processes listen for commands on a unix stream socket. The
control library supports scanning the socket namespace for running
tapdisks, VBD minors allocated, associated images and state inquiry.

Control operations include allocating/releasing devices, spawning
tapdisks, opening/closing images, attaching disk images to
devices. disk pause/resume operations and runtime switching of disk
images.

Signed-off-by: Jake Wires <jake.wires@citrix.com>
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>

2 files changed, 130 insertions, 1 deletions

diff --git a/tools/blktap2/include/blktap2.h b/tools/blktap2/include/blktap2.h
new file mode 100644
index 0000000000..bf923fc08d
--- /dev/null
+++ b/tools/blktap2/include/blktap2.h
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of XenSource Inc. nor the names of its contributors
+ *       may be used to endorse or promote products derived from this software
+ *       without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _BLKTAP_2_H_
+#define _BLKTAP_2_H_
+
+#define BLKTAP2_MAX_MESSAGE_LEN        256
+
+#define BLKTAP2_RING_MESSAGE_PAUSE     1
+#define BLKTAP2_RING_MESSAGE_RESUME    2
+#define BLKTAP2_RING_MESSAGE_CLOSE     3
+
+#define BLKTAP2_IOCTL_KICK_FE          1
+#define BLKTAP2_IOCTL_ALLOC_TAP        200
+#define BLKTAP2_IOCTL_FREE_TAP         201
+#define BLKTAP2_IOCTL_CREATE_DEVICE    202
+#define BLKTAP2_IOCTL_SET_PARAMS       203
+#define BLKTAP2_IOCTL_PAUSE            204
+#define BLKTAP2_IOCTL_REOPEN           205
+#define BLKTAP2_IOCTL_RESUME           206
+
+#define BLKTAP2_SYSFS_DIR              "/sys/class/blktap2"
+#define BLKTAP2_CONTROL_NAME           "blktap-control"
+#define BLKTAP2_CONTROL_DIR            "/var/run/"BLKTAP2_CONTROL_NAME
+#define BLKTAP2_CONTROL_SOCKET         "ctl"
+#define BLKTAP2_DIRECTORY              "/dev/xen/blktap-2"
+#define BLKTAP2_CONTROL_DEVICE         BLKTAP2_DIRECTORY"/control"
+#define BLKTAP2_RING_DEVICE            BLKTAP2_DIRECTORY"/blktap"
+#define BLKTAP2_IO_DEVICE              BLKTAP2_DIRECTORY"/tapdev"
+
+struct blktap2_handle {
+	unsigned int                   ring;
+	unsigned int                   device;
+	unsigned int                   minor;
+};
+
+struct blktap2_params {
+	char                           name[BLKTAP2_MAX_MESSAGE_LEN];
+	unsigned long long             capacity;
+	unsigned long                  sector_size;
+};
+
+#endif
diff --git a/tools/blktap2/include/tapdisk-message.h b/tools/blktap2/include/tapdisk-message.h
index dc622bd71d..63a15a2c08 100644
--- a/tools/blktap2/include/tapdisk-message.h
+++ b/tools/blktap2/include/tapdisk-message.h
@@ -33,6 +33,9 @@
 #define TAPDISK_MESSAGE_MAX_PATH_LENGTH  256
 #define TAPDISK_MESSAGE_STRING_LENGTH    256
 
+#define TAPDISK_MESSAGE_MAX_MINORS \
+	((TAPDISK_MESSAGE_MAX_PATH_LENGTH / sizeof(int)) - 1)
+
 #define TAPDISK_MESSAGE_FLAG_SHARED      0x01
 #define TAPDISK_MESSAGE_FLAG_RDONLY      0x02
 #define TAPDISK_MESSAGE_FLAG_ADD_CACHE   0x04
@@ -44,10 +47,13 @@ typedef uint8_t                          tapdisk_message_flag_t;
 typedef struct tapdisk_message_image     tapdisk_message_image_t;
 typedef struct tapdisk_message_params    tapdisk_message_params_t;
 typedef struct tapdisk_message_string    tapdisk_message_string_t;
+typedef struct tapdisk_message_response  tapdisk_message_response_t;
+typedef struct tapdisk_message_minors    tapdisk_message_minors_t;
+typedef struct tapdisk_message_list      tapdisk_message_list_t;
 
 struct tapdisk_message_params {
 	tapdisk_message_flag_t           flags;
-	
+
 	uint8_t                          storage;
 	uint32_t                         devnum;
 	uint32_t                         domid;
@@ -65,6 +71,23 @@ struct tapdisk_message_string {
 	char                             text[TAPDISK_MESSAGE_STRING_LENGTH];
 };
 
+struct tapdisk_message_response {
+	int                              error;
+	char                             message[TAPDISK_MESSAGE_STRING_LENGTH];
+};
+
+struct tapdisk_message_minors {
+	int                              count;
+	int                              list[TAPDISK_MESSAGE_MAX_MINORS];
+};
+
+struct tapdisk_message_list {
+	int                              count;
+	int                              minor;
+	int                              state;
+	char                             path[TAPDISK_MESSAGE_MAX_PATH_LENGTH];
+};
+
 struct tapdisk_message {
 	uint16_t                         type;
 	uint16_t                         cookie;
@@ -74,6 +97,9 @@ struct tapdisk_message {
 		tapdisk_message_image_t  image;
 		tapdisk_message_params_t params;
 		tapdisk_message_string_t string;
+		tapdisk_message_minors_t minors;
+		tapdisk_message_response_t response;
+		tapdisk_message_list_t   list;
 	} u;
 };
 
@@ -82,6 +108,8 @@ enum tapdisk_message_id {
 	TAPDISK_MESSAGE_RUNTIME_ERROR,
 	TAPDISK_MESSAGE_PID,
 	TAPDISK_MESSAGE_PID_RSP,
+	TAPDISK_MESSAGE_ATTACH,
+	TAPDISK_MESSAGE_ATTACH_RSP,
 	TAPDISK_MESSAGE_OPEN,
 	TAPDISK_MESSAGE_OPEN_RSP,
 	TAPDISK_MESSAGE_PAUSE,
@@ -90,6 +118,13 @@ enum tapdisk_message_id {
 	TAPDISK_MESSAGE_RESUME_RSP,
 	TAPDISK_MESSAGE_CLOSE,
 	TAPDISK_MESSAGE_CLOSE_RSP,
+	TAPDISK_MESSAGE_DETACH,
+	TAPDISK_MESSAGE_DETACH_RSP,
+	TAPDISK_MESSAGE_LIST_MINORS,
+	TAPDISK_MESSAGE_LIST_MINORS_RSP,
+	TAPDISK_MESSAGE_LIST,
+	TAPDISK_MESSAGE_LIST_RSP,
+	TAPDISK_MESSAGE_FORCE_SHUTDOWN,
 	TAPDISK_MESSAGE_EXIT,
 };
 
@@ -127,9 +162,36 @@ tapdisk_message_name(enum tapdisk_message_id id)
 	case TAPDISK_MESSAGE_CLOSE:
 		return "close";
 
+	case TAPDISK_MESSAGE_FORCE_SHUTDOWN:
+		return "force shutdown";
+
 	case TAPDISK_MESSAGE_CLOSE_RSP:
 		return "close response";
 
+	case TAPDISK_MESSAGE_ATTACH:
+		return "attach";
+
+	case TAPDISK_MESSAGE_ATTACH_RSP:
+		return "attach response";
+
+	case TAPDISK_MESSAGE_DETACH:
+		return "detach";
+
+	case TAPDISK_MESSAGE_DETACH_RSP:
+		return "detach response";
+
+	case TAPDISK_MESSAGE_LIST_MINORS:
+		return "list minors";
+
+	case TAPDISK_MESSAGE_LIST_MINORS_RSP:
+		return "list minors response";
+
+	case TAPDISK_MESSAGE_LIST:
+		return "list";
+
+	case TAPDISK_MESSAGE_LIST_RSP:
+		return "list response";
+
 	case TAPDISK_MESSAGE_EXIT:
 		return "exit";