[PATCH 00/17] drivers: hv: kvp

@@ -146,43 +146,9 @@ static ssize_t vmbus_show_device_attr(struct device *dev,
 	get_channel_info(hv_dev, device_info);
 
 	if (!strcmp(dev_attr->attr.name, "class_id")) {
-		ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
-			       "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
-			       device_info->chn_type.b[3],
-			       device_info->chn_type.b[2],
-			       device_info->chn_type.b[1],
-			       device_info->chn_type.b[0],
-			       device_info->chn_type.b[5],
-			       device_info->chn_type.b[4],
-			       device_info->chn_type.b[7],
-			       device_info->chn_type.b[6],
-			       device_info->chn_type.b[8],
-			       device_info->chn_type.b[9],
-			       device_info->chn_type.b[10],
-			       device_info->chn_type.b[11],
-			       device_info->chn_type.b[12],
-			       device_info->chn_type.b[13],
-			       device_info->chn_type.b[14],
-			       device_info->chn_type.b[15]);
+		ret = sprintf(buf, "{%pUl}\n", device_info->chn_type.b);
 	} else if (!strcmp(dev_attr->attr.name, "device_id")) {
-		ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
-			       "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
-			       device_info->chn_instance.b[3],
-			       device_info->chn_instance.b[2],
-			       device_info->chn_instance.b[1],
-			       device_info->chn_instance.b[0],
-			       device_info->chn_instance.b[5],
-			       device_info->chn_instance.b[4],
-			       device_info->chn_instance.b[7],
-			       device_info->chn_instance.b[6],
-			       device_info->chn_instance.b[8],
-			       device_info->chn_instance.b[9],
-			       device_info->chn_instance.b[10],
-			       device_info->chn_instance.b[11],
-			       device_info->chn_instance.b[12],
-			       device_info->chn_instance.b[13],
-			       device_info->chn_instance.b[14],
-			       device_info->chn_instance.b[15]);
+		ret = sprintf(buf, "{%pUl}\n", device_info->chn_instance.b);
 	} else if (!strcmp(dev_attr->attr.name, "modalias")) {
 		print_alias_name(hv_dev, alias_name);
 		ret = sprintf(buf, "vmbus:%s\n", alias_name);

@@ -263,7 +263,7 @@ static int util_probe(struct hv_device *dev,
 		(struct hv_util_service *)dev_id->driver_data;
 	int ret;
 
-	srv->recv_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	srv->recv_buffer = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
 	if (!srv->recv_buffer)
 		return -ENOMEM;
 	if (srv->util_init) {

@@ -274,7 +274,7 @@ static int util_probe(struct hv_device *dev,
 		}
 	}
 
-	ret = vmbus_open(dev->channel, 2 * PAGE_SIZE, 2 * PAGE_SIZE, NULL, 0,
+	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
 			srv->util_cb, dev->channel);
 	if (ret)
 		goto error;

@@ -122,12 +122,53 @@
 #define REG_U32 4
 #define REG_U64 8
 
+/*
+ * As we look at expanding the KVP functionality to include
+ * IP injection functionality, we need to maintain binary
+ * compatibility with older daemons.
+ *
+ * The KVP opcodes are defined by the host and it was unfortunate
+ * that I chose to treat the registration operation as part of the
+ * KVP operations defined by the host.
+ * Here is the level of compatibility
+ * (between the user level daemon and the kernel KVP driver) that we
+ * will implement:
+ *
+ * An older daemon will always be supported on a newer driver.
+ * A given user level daemon will require a minimal version of the
+ * kernel driver.
+ * If we cannot handle the version differences, we will fail gracefully
+ * (this can happen when we have a user level daemon that is more
+ * advanced than the KVP driver.
+ *
+ * We will use values used in this handshake for determining if we have
+ * workable user level daemon and the kernel driver. We begin by taking the
+ * registration opcode out of the KVP opcode namespace. We will however,
+ * maintain compatibility with the existing user-level daemon code.
+ */
+
+/*
+ * Daemon code not supporting IP injection (legacy daemon).
+ */
+
+#define KVP_OP_REGISTER	4
+
+/*
+ * Daemon code supporting IP injection.
+ * The KVP opcode field is used to communicate the
+ * registration information; so define a namespace that
+ * will be distinct from the host defined KVP opcode.
+ */
+
+#define KVP_OP_REGISTER1 100
+
 enum hv_kvp_exchg_op {
 	KVP_OP_GET = 0,
 	KVP_OP_SET,
 	KVP_OP_DELETE,
 	KVP_OP_ENUMERATE,
-	KVP_OP_REGISTER,
+	KVP_OP_GET_IP_INFO,
+	KVP_OP_SET_IP_INFO,
 	KVP_OP_COUNT /* Number of operations, must be last. */
 };
 

@@ -140,6 +181,26 @@ enum hv_kvp_exchg_pool {
 	KVP_POOL_COUNT /* Number of pools, must be last. */
 };
 
+#define ADDR_FAMILY_NONE	0x00
+#define ADDR_FAMILY_IPV4	0x01
+#define ADDR_FAMILY_IPV6	0x02
+
+#define MAX_ADAPTER_ID_SIZE	128
+#define MAX_IP_ADDR_SIZE	1024
+#define MAX_GATEWAY_SIZE	512
+
+
+struct hv_kvp_ipaddr_value {
+	__u16	adapter_id[MAX_ADAPTER_ID_SIZE];
+	__u8	addr_family;
+	__u8	dhcp_enabled;
+	__u16	ip_addr[MAX_IP_ADDR_SIZE];
+	__u16	sub_net[MAX_IP_ADDR_SIZE];
+	__u16	gate_way[MAX_GATEWAY_SIZE];
+	__u16	dns_addr[MAX_IP_ADDR_SIZE];
+} __attribute__((packed));
+
+
 struct hv_kvp_hdr {
 	__u8 operation;
 	__u8 pool;

@@ -187,10 +248,17 @@ struct hv_kvp_msg {
 		struct hv_kvp_msg_set		kvp_set;
 		struct hv_kvp_msg_delete	kvp_delete;
 		struct hv_kvp_msg_enumerate	kvp_enum_data;
+		struct hv_kvp_ipaddr_value      kvp_ip_val;
 		struct hv_kvp_register		kvp_register;
 	} body;
 } __attribute__((packed));
 
+struct hv_kvp_ip_msg {
+	__u8 operation;
+	__u8 pool;
+	struct hv_kvp_ipaddr_value      kvp_ip_val;
+} __attribute__((packed));
+
 #ifdef __KERNEL__
 #include <linux/scatterlist.h>
 #include <linux/list.h>

@@ -982,6 +1050,7 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
 #define HV_S_CONT			0x80070103
 #define HV_ERROR_NOT_SUPPORTED		0x80070032
 #define HV_ERROR_MACHINE_LOCKED		0x800704F7
+#define HV_ERROR_DEVICE_NOT_CONNECTED	0x8007048F
 
 /*
  * While we want to handle util services as regular devices,

@@ -69,7 +69,7 @@ enum key_index {
 };
 
 static char kvp_send_buffer[4096];
-static char kvp_recv_buffer[4096];
+static char kvp_recv_buffer[4096 * 2];
 static struct sockaddr_nl addr;
 
 static char *os_name = "";

@@ -96,8 +96,8 @@ static struct utsname uts_buf;
 #define ENTRIES_PER_BLOCK 50
 
 struct kvp_record {
-	__u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
-	__u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
+	char key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
+	char value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
 };
 
 struct kvp_file_state {

@@ -105,7 +105,7 @@ struct kvp_file_state {
 	int num_blocks;
 	struct kvp_record *records;
 	int num_records;
-	__u8 fname[MAX_FILE_NAME];
+	char fname[MAX_FILE_NAME];
 };
 
 static struct kvp_file_state kvp_file_info[KVP_POOL_COUNT];

@@ -209,7 +209,7 @@ static int kvp_file_init(void)
 	int  fd;
 	FILE *filep;
 	size_t records_read;
-	__u8 *fname;
+	char *fname;
 	struct kvp_record *record;
 	struct kvp_record *readp;
 	int num_blocks;

@@ -206,7 +206,7 @@ static void kvp_update_mem_state(int pool)
 }
 static int kvp_file_init(void)
 {
-	int ret, fd;
+	int  fd;
 	FILE *filep;
 	size_t records_read;
 	__u8 *fname;

@@ -322,7 +322,6 @@ static int kvp_key_add_or_modify(int pool, __u8 *key, int key_size, __u8 *value,
 			int value_size)
 {
 	int i;
-	int j, k;
 	int num_records;
 	struct kvp_record *record;
 	int num_blocks;

@@ -491,6 +491,72 @@ done:
 	return;
 }
 
+static void kvp_process_ipconfig_file(char *cmd,
+					char *config_buf, int len,
+					int element_size, int offset)
+{
+	char buf[256];
+	char *p;
+	char *x;
+	FILE *file;
+
+	/*
+	 * First execute the command.
+	 */
+	file = popen(cmd, "r");
+	if (file == NULL)
+		return;
+
+	if (offset == 0)
+		memset(config_buf, 0, len);
+	while ((p = fgets(buf, sizeof(buf), file)) != NULL) {
+		if ((len - strlen(config_buf)) < (element_size + 1))
+			break;
+
+		x = strchr(p, '\n');
+		*x = '\0';
+		strcat(config_buf, p);
+		strcat(config_buf, ";");
+	}
+	pclose(file);
+}
+
+static void kvp_get_ipconfig_info(char *if_name,
+				 struct hv_kvp_ipaddr_value *buffer)
+{
+	char cmd[512];
+
+	/*
+	 * Get the address of default gateway (ipv4).
+	 */
+	memset(cmd, 0, sizeof(cmd));
+	strcat(cmd, "/sbin/ip -f inet  route | grep -w ");
+	strcat(cmd, if_name);
+	strcat(cmd, " | awk '/default/ {print $3 }'");
+
+	/*
+	 * Execute the command to gather gateway info.
+	 */
+	kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way,
+				(MAX_GATEWAY_SIZE * 2), INET_ADDRSTRLEN, 0);
+
+	/*
+	 * Get the address of default gateway (ipv6).
+	 */
+	memset(cmd, 0, sizeof(cmd));
+	strcat(cmd, "/sbin/ip -f inet6  route | grep -w ");
+	strcat(cmd, if_name);
+	strcat(cmd, " | awk '/default/ {print $3 }'");
+
+	/*
+	 * Execute the command to gather gateway info (ipv6).
+	 */
+	kvp_process_ipconfig_file(cmd, (char *)buffer->gate_way,
+				(MAX_GATEWAY_SIZE * 2), INET6_ADDRSTRLEN, 1);
+
+}
+
+
 static unsigned int hweight32(unsigned int *w)
 {
 	unsigned int res = *w - ((*w >> 1) & 0x55555555);

@@ -649,6 +715,12 @@ kvp_get_ip_address(int family, char *if_name, int op,
 				strcat((char *)ip_buffer->sub_net, ";");
 				sn_offset += strlen(sn_str) + 1;
 			}
+
+			/*
+			 * Collect other ip related configuration info.
+			 */
+
+			kvp_get_ipconfig_info(if_name, ip_buffer);
 		}
 
 gather_ipaddr:

@@ -491,6 +491,15 @@ done:
 	return;
 }
 
+static unsigned int hweight32(unsigned int *w)
+{
+	unsigned int res = *w - ((*w >> 1) & 0x55555555);
+	res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
+	res = (res + (res >> 4)) & 0x0F0F0F0F;
+	res = res + (res >> 8);
+	return (res + (res >> 16)) & 0x000000FF;
+}
+
 static int kvp_process_ip_address(void *addrp,
 				int family, char *buffer,
 				int length,  int *offset)

@@ -535,10 +544,15 @@ kvp_get_ip_address(int family, char *if_name, int op,
 	struct ifaddrs *curp;
 	int offset = 0;
 	int sn_offset = 0;
-	const char *str;
 	int error = 0;
 	char *buffer;
 	struct hv_kvp_ipaddr_value *ip_buffer;
+	char cidr_mask[5]; /* /xyz */
+	int weight;
+	int i;
+	unsigned int *w;
+	char *sn_str;
+	struct sockaddr_in6 *addr6;
 
 	if (op == KVP_OP_ENUMERATE) {
 		buffer = out_buffer;

@@ -612,17 +626,28 @@ kvp_get_ip_address(int family, char *if_name, int op,
 			} else {
 				ip_buffer->addr_family |= ADDR_FAMILY_IPV6;
 				/*
-				 * Get subnet info.
+				 * Get subnet info in CIDR format.
 				 */
-				error = kvp_process_ip_address(
-							curp->ifa_netmask,
-							AF_INET6,
-							(char *)
-							ip_buffer->sub_net,
-							length,
-							&sn_offset);
-				if (error)
+				weight = 0;
+				sn_str = (char *)ip_buffer->sub_net;
+				addr6 = (struct sockaddr_in6 *)
+					curp->ifa_netmask;
+				w = addr6->sin6_addr.s6_addr32;
+
+				for (i = 0; i < 4; i++)
+					weight += hweight32(&w[i]);
+
+				sprintf(cidr_mask, "/%d", weight);
+				if ((length - sn_offset) <
+					(strlen(cidr_mask) + 1))
 					goto gather_ipaddr;
+
+				if (sn_offset == 0)
+					strcpy(sn_str, cidr_mask);
+				else
+					strcat(sn_str, cidr_mask);
+				strcat((char *)ip_buffer->sub_net, ";");
+				sn_offset += strlen(sn_str) + 1;
 			}
 		}
 

@@ -589,6 +589,17 @@ kvp_get_ip_address(int family, char *if_name, int op,
 			continue;
 		}
 
+		if (op == KVP_OP_GET_IP_INFO) {
+			/*
+			 * Gather info other than the IP address.
+			 * IP address info will be gathered later.
+			 */
+			if (curp->ifa_addr->sa_family == AF_INET)
+				ip_buffer->addr_family |= ADDR_FAMILY_IPV4;
+			else
+				ip_buffer->addr_family |= ADDR_FAMILY_IPV6;
+		}
+
 		error = kvp_process_ip_address(curp->ifa_addr,
 						curp->ifa_addr->sa_family,
 						buffer,

@@ -491,17 +491,50 @@ done:
 	return;
 }
 
+static int kvp_process_ip_address(void *addrp,
+				int family, char *buffer,
+				int length,  int *offset)
+{
+	struct sockaddr_in *addr;
+	struct sockaddr_in6 *addr6;
+	int addr_length;
+	char tmp[50];
+	const char *str;
+
+	if (family == AF_INET) {
+		addr = (struct sockaddr_in *)addrp;
+		str = inet_ntop(family, &addr->sin_addr, tmp, 50);
+		addr_length = INET_ADDRSTRLEN;
+	} else {
+		addr6 = (struct sockaddr_in6 *)addrp;
+		str = inet_ntop(family, &addr6->sin6_addr.s6_addr, tmp, 50);
+		addr_length = INET6_ADDRSTRLEN;
+	}
+
+	if ((length - *offset) < addr_length + 1)
+		return 1;
+	if (str == NULL) {
+		strcpy(buffer, "inet_ntop failed\n");
+		return 1;
+	}
+	if (*offset == 0)
+		strcpy(buffer, tmp);
+	else
+		strcat(buffer, tmp);
+	strcat(buffer, ";");
+
+	*offset += strlen(str) + 1;
+	return 0;
+}
+
 static int
 kvp_get_ip_address(int family, char *if_name, int op,
 		 void  *out_buffer, int length)
 {
 	struct ifaddrs *ifap;
 	struct ifaddrs *curp;
-	int ipv4_len = strlen("255.255.255.255") + 1;
-	int ipv6_len = strlen("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")+1;
 	int offset = 0;
 	const char *str;
-	char tmp[50];
 	int error = 0;
 	char *buffer;
 	struct hv_kvp_ipaddr_value *ip_buffer;

@@ -556,55 +589,12 @@ kvp_get_ip_address(int family, char *if_name, int op,
 			continue;
 		}
 
-		if ((curp->ifa_addr->sa_family == AF_INET) &&
-			((family == AF_INET) || (family == 0))) {
-			struct sockaddr_in *addr =
-			(struct sockaddr_in *) curp->ifa_addr;
-
-			str = inet_ntop(AF_INET, &addr->sin_addr, tmp, 50);
-			if (str == NULL) {
-				strcpy(buffer, "inet_ntop failed\n");
-				error = 1;
-				goto getaddr_done;
-			}
-			if (offset == 0)
-				strcpy(buffer, tmp);
-			else
-				strcat(buffer, tmp);
-			strcat(buffer, ";");
-
-			offset += strlen(str) + 1;
-			if ((length - offset) < (ipv4_len + 1))
-				goto getaddr_done;
-
-		} else if ((family == AF_INET6) || (family == 0)) {
-
-			/*
-			 * We only support AF_INET and AF_INET6
-			 * and the list of addresses is separated by a ";".
-			 */
-			struct sockaddr_in6 *addr =
-				(struct sockaddr_in6 *) curp->ifa_addr;
-
-			str = inet_ntop(AF_INET6,
-					&addr->sin6_addr.s6_addr,
-					tmp, 50);
-			if (str == NULL) {
-				strcpy(buffer, "inet_ntop failed\n");
-				error = 1;
-				goto getaddr_done;
-			}
-			if (offset == 0)
-				strcpy(buffer, tmp);
-			else
-				strcat(buffer, tmp);
-			strcat(buffer, ";");
-			offset += strlen(str) + 1;
-			if ((length - offset) < (ipv6_len + 1))
-				goto getaddr_done;
-
-		}
-
+		error = kvp_process_ip_address(curp->ifa_addr,
+						curp->ifa_addr->sa_family,
+						buffer,
+						length, &offset);
+		if (error)
+			goto getaddr_done;
 
 		curp = curp->ifa_next;
 	}

@@ -48,13 +48,24 @@ static struct {
 	void *kvp_context; /* for the channel callback */
 } kvp_transaction;
 
+/*
+ * Before we can accept KVP messages from the host, we need
+ * to handshake with the user level daemon. This state tarcks
+ * if we are in the handshake phase.
+ */
+static bool in_hand_shake = true;
+
+/*
+ * This state maintains the version number registered by the daemon.
+ */
+static int dm_reg_value;
+
 static void kvp_send_key(struct work_struct *dummy);
 
-#define TIMEOUT_FIRED 1
 
 static void kvp_respond_to_host(char *key, char *value, int error);
 static void kvp_work_func(struct work_struct *dummy);
-static void kvp_register(void);
+static void kvp_register(int);
 
 static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
 static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);

@@ -68,7 +79,7 @@ static u8 *recv_buffer;
  */
 
 static void
-kvp_register(void)
+kvp_register(int reg_value)
 {
 
 	struct cn_msg *msg;

@@ -83,7 +94,7 @@ kvp_register(void)
 		msg->id.idx =  CN_KVP_IDX;
 		msg->id.val = CN_KVP_VAL;
 
-		kvp_msg->kvp_hdr.operation = KVP_OP_REGISTER;
+		kvp_msg->kvp_hdr.operation = reg_value;
 		strcpy(version, HV_DRV_VERSION);
 		msg->len = sizeof(struct hv_kvp_msg);
 		cn_netlink_send(msg, 0, GFP_ATOMIC);

@@ -97,9 +108,43 @@ kvp_work_func(struct work_struct *dummy)
 	 * If the timer fires, the user-mode component has not responded;
 	 * process the pending transaction.
 	 */
-	kvp_respond_to_host("Unknown key", "Guest timed out", TIMEOUT_FIRED);
+	kvp_respond_to_host("Unknown key", "Guest timed out", HV_E_FAIL);
+}
+
+static int kvp_handle_handshake(struct hv_kvp_msg *msg)
+{
+	int ret = 1;
+
+	switch (msg->kvp_hdr.operation) {
+	case KVP_OP_REGISTER:
+		dm_reg_value = KVP_OP_REGISTER;
+		pr_info("KVP: IP injection functionality not available\n");
+		pr_info("KVP: Upgrade the KVP daemon\n");
+		break;
+	case KVP_OP_REGISTER1:
+		dm_reg_value = KVP_OP_REGISTER1;
+		break;
+	default:
+		pr_info("KVP: incompatible daemon\n");
+		pr_info("KVP: KVP version: %d, Daemon version: %d\n",
+			KVP_OP_REGISTER1, msg->kvp_hdr.operation);
+		ret = 0;
+	}
+
+	if (ret) {
+		/*
+		 * We have a compatible daemon; complete the handshake.
+		 */
+		pr_info("KVP: user-mode registering done.\n");
+		kvp_register(dm_reg_value);
+		kvp_transaction.active = false;
+		if (kvp_transaction.kvp_context)
+			hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
+	}
+	return ret;
 }
 
+
 /*
  * Callback when data is received from user mode.
  */

@@ -109,27 +154,52 @@ kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 {
 	struct hv_kvp_msg *message;
 	struct hv_kvp_msg_enumerate *data;
+	int	error = 0;
 
 	message = (struct hv_kvp_msg *)msg->data;
-	switch (message->kvp_hdr.operation) {
+
+	/*
+	 * If we are negotiating the version information
+	 * with the daemon; handle that first.
+	 */
+
+	if (in_hand_shake) {
+		if (kvp_handle_handshake(message))
+			in_hand_shake = false;
+		return;
+	}
+
+	/*
+	 * Based on the version of the daemon, we propagate errors from the
+	 * daemon differently.
+	 */
+
+	data = &message->body.kvp_enum_data;
+
+	switch (dm_reg_value) {
 	case KVP_OP_REGISTER:
-		pr_info("KVP: user-mode registering done.\n");
-		kvp_register();
-		kvp_transaction.active = false;
-		hv_kvp_onchannelcallback(kvp_transaction.kvp_context);
+		/*
+		 * Null string is used to pass back error condition.
+		 */
+		if (!strlen(data->data.key))
+			error = HV_S_CONT;
 		break;
 
-	default:
-		data = &message->body.kvp_enum_data;
+	case KVP_OP_REGISTER1:
 		/*
-		 * Complete the transaction by forwarding the key value
-		 * to the host. But first, cancel the timeout.
+		 * We use the message header information from
+		 * the user level daemon to transmit errors.
 		 */
-		if (cancel_delayed_work_sync(&kvp_work))
-			kvp_respond_to_host(data->data.key,
-					 data->data.value,
-					!strlen(data->data.key));
+		error = *((int *)(&message->kvp_hdr.operation));
+		break;
 	}
+
+	/*
+	 * Complete the transaction by forwarding the key value
+	 * to the host. But first, cancel the timeout.
+	 */
+	if (cancel_delayed_work_sync(&kvp_work))
+		kvp_respond_to_host(data->data.key, data->data.value, error);
 }
 
 static void

@@ -287,6 +357,7 @@ kvp_respond_to_host(char *key, char *value, int error)
 		 */
 		return;
 
+	icmsghdrp->status = error;
 
 	/*
 	 * If the error parameter is set, terminate the host's enumeration

@@ -294,15 +365,12 @@ kvp_respond_to_host(char *key, char *value, int error)
 	 */
 	if (error) {
 		/*
-		 * Something failed or the we have timedout;
+		 * Something failed or  we have timedout;
 		 * terminate the current  host-side iteration.
 		 */
-		icmsghdrp->status = HV_S_CONT;
 		goto response_done;
 	}
 
-	icmsghdrp->status = HV_S_OK;
-
 	kvp_msg = (struct hv_kvp_msg *)
 			&recv_buffer[sizeof(struct vmbuspipe_hdr) +
 			sizeof(struct icmsg_hdr)];

@@ -181,6 +181,17 @@ enum hv_kvp_exchg_pool {
 	KVP_POOL_COUNT /* Number of pools, must be last. */
 };
 
+/*
+ * Some Hyper-V status codes.
+ */
+
+#define HV_S_OK				0x00000000
+#define HV_E_FAIL			0x80004005
+#define HV_S_CONT			0x80070103
+#define HV_ERROR_NOT_SUPPORTED		0x80070032
+#define HV_ERROR_MACHINE_LOCKED		0x800704F7
+#define HV_ERROR_DEVICE_NOT_CONNECTED	0x8007048F
+
 #define ADDR_FAMILY_NONE	0x00
 #define ADDR_FAMILY_IPV4	0x01
 #define ADDR_FAMILY_IPV6	0x02

@@ -1045,12 +1056,6 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
 #define ICMSGHDRFLAG_REQUEST		2
 #define ICMSGHDRFLAG_RESPONSE		4
 
-#define HV_S_OK				0x00000000
-#define HV_E_FAIL			0x80004005
-#define HV_S_CONT			0x80070103
-#define HV_ERROR_NOT_SUPPORTED		0x80070032
-#define HV_ERROR_MACHINE_LOCKED		0x800704F7
-#define HV_ERROR_DEVICE_NOT_CONNECTED	0x8007048F
 
 /*
  * While we want to handle util services as regular devices,

@@ -71,13 +71,14 @@ enum key_index {
 static char kvp_send_buffer[4096];
 static char kvp_recv_buffer[4096 * 2];
 static struct sockaddr_nl addr;
+static int in_hand_shake = 1;
 
 static char *os_name = "";
 static char *os_major = "";
 static char *os_minor = "";
 static char *processor_arch;
 static char *os_build;
-static char *lic_version;
+static char *lic_version = "Unknown version";
 static struct utsname uts_buf;
 
 

@@ -394,7 +395,7 @@ static int kvp_get_value(int pool, __u8 *key, int key_size, __u8 *value,
 	return 1;
 }
 
-static void kvp_pool_enumerate(int pool, int index, __u8 *key, int key_size,
+static int kvp_pool_enumerate(int pool, int index, __u8 *key, int key_size,
 				__u8 *value, int value_size)
 {
 	struct kvp_record *record;

@@ -406,16 +407,12 @@ static void kvp_pool_enumerate(int pool, int index, __u8 *key, int key_size,
 	record = kvp_file_info[pool].records;
 
 	if (index >= kvp_file_info[pool].num_records) {
-		/*
-		 * This is an invalid index; terminate enumeration;
-		 * - a NULL value will do the trick.
-		 */
-		strcpy(value, "");
-		return;
+		return 1;
 	}
 
 	memcpy(key, record[index].key, key_size);
 	memcpy(value, record[index].value, value_size);
+	return 0;
 }
 
 

@@ -646,6 +643,8 @@ int main(void)
 	char	*p;
 	char	*key_value;
 	char	*key_name;
+	int	op;
+	int	pool;
 
 	daemon(1, 0);
 	openlog("KVP", 0, LOG_USER);

@@ -687,7 +686,7 @@ int main(void)
 	message->id.val = CN_KVP_VAL;
 
 	hv_msg = (struct hv_kvp_msg *)message->data;
-	hv_msg->kvp_hdr.operation = KVP_OP_REGISTER;
+	hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1;
 	message->ack = 0;
 	message->len = sizeof(struct hv_kvp_msg);
 

@@ -721,12 +720,21 @@ int main(void)
 		incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
 		hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
 
-		switch (hv_msg->kvp_hdr.operation) {
-		case KVP_OP_REGISTER:
+		/*
+		 * We will use the KVP header information to pass back
+		 * the error from this daemon. So, first copy the state
+		 * and set the error code to success.
+		 */
+		op = hv_msg->kvp_hdr.operation;
+		pool = hv_msg->kvp_hdr.pool;
+		*((int *)(&hv_msg->kvp_hdr.operation)) = HV_S_OK;
+
+		if ((in_hand_shake) && (op == KVP_OP_REGISTER1)) {
 			/*
 			 * Driver is registering with us; stash away the version
 			 * information.
 			 */
+			in_hand_shake = 0;
 			p = (char *)hv_msg->body.kvp_register.version;
 			lic_version = malloc(strlen(p) + 1);
 			if (lic_version) {

@@ -737,44 +745,42 @@ int main(void)
 				syslog(LOG_ERR, "malloc failed");
 			}
 			continue;
+		}
 
-		/*
-		 * The current protocol with the kernel component uses a
-		 * NULL key name to pass an error condition.
-		 * For the SET, GET and DELETE operations,
-		 * use the existing protocol to pass back error.
-		 */
-
+		switch (op) {
 		case KVP_OP_SET:
-			if (kvp_key_add_or_modify(hv_msg->kvp_hdr.pool,
+			if (kvp_key_add_or_modify(pool,
 					hv_msg->body.kvp_set.data.key,
 					hv_msg->body.kvp_set.data.key_size,
 					hv_msg->body.kvp_set.data.value,
 					hv_msg->body.kvp_set.data.value_size))
-				strcpy(hv_msg->body.kvp_set.data.key, "");
+				*((int *)(&hv_msg->kvp_hdr.operation)) =
+								HV_S_CONT;
 			break;
 
 		case KVP_OP_GET:
-			if (kvp_get_value(hv_msg->kvp_hdr.pool,
+			if (kvp_get_value(pool,
 					hv_msg->body.kvp_set.data.key,
 					hv_msg->body.kvp_set.data.key_size,
 					hv_msg->body.kvp_set.data.value,
 					hv_msg->body.kvp_set.data.value_size))
-				strcpy(hv_msg->body.kvp_set.data.key, "");
+				*((int *)(&hv_msg->kvp_hdr.operation)) =
+								HV_S_CONT;
 			break;
 
 		case KVP_OP_DELETE:
-			if (kvp_key_delete(hv_msg->kvp_hdr.pool,
+			if (kvp_key_delete(pool,
 					hv_msg->body.kvp_delete.key,
 					hv_msg->body.kvp_delete.key_size))
-				strcpy(hv_msg->body.kvp_delete.key, "");
+				*((int *)(&hv_msg->kvp_hdr.operation)) =
+								HV_S_CONT;
 			break;
 
 		default:
 			break;
 		}
 
-		if (hv_msg->kvp_hdr.operation != KVP_OP_ENUMERATE)
+		if (op != KVP_OP_ENUMERATE)
 			goto kvp_done;
 
 		/*

@@ -782,13 +788,15 @@ int main(void)
 		 * both the key and the value; if not read from the
 		 * appropriate pool.
 		 */
-		if (hv_msg->kvp_hdr.pool != KVP_POOL_AUTO) {
-			kvp_pool_enumerate(hv_msg->kvp_hdr.pool,
+		if (pool != KVP_POOL_AUTO) {
+			if (kvp_pool_enumerate(pool,
 					hv_msg->body.kvp_enum_data.index,
 					hv_msg->body.kvp_enum_data.data.key,
 					HV_KVP_EXCHANGE_MAX_KEY_SIZE,
 					hv_msg->body.kvp_enum_data.data.value,
-					HV_KVP_EXCHANGE_MAX_VALUE_SIZE);
+					HV_KVP_EXCHANGE_MAX_VALUE_SIZE))
+				*((int *)(&hv_msg->kvp_hdr.operation)) =
+								HV_S_CONT;
 			goto kvp_done;
 		}
 

@@ -841,11 +849,7 @@ int main(void)
 			strcpy(key_name, "ProcessorArchitecture");
 			break;
 		default:
-			strcpy(key_value, "Unknown Key");
-			/*
-			 * We use a null key name to terminate enumeration.
-			 */
-			strcpy(key_name, "");
+			*((int *)(&hv_msg->kvp_hdr.operation)) = HV_S_CONT;
 			break;
 		}
 		/*