[PATCH RFC 1/3] Drivers: hv: kvp: convert userspace/kernel communication to using char device

From: Vitaly Kuznetsov
Date: Fri Feb 27 2015 - 11:14:43 EST

Userspace/kernel communication via netlink has a number of issues:
- It is hard for userspace to figure out if the kernel part was loaded or not
and this fact can change as there is a way to enable/disable the service from
host side. Racy daemon startup is also a problem.
- When the userspace daemon restarts/dies kernel part doesn't receive a
notification.
- Netlink communication is not stable under heavy load.
- ...

Re-implement the communication using misc char device. Use ioctl to do
kernel/userspace version negotiation (doesn't make much sense at this moment
as we're breaking backwards compatibility but can be used in future).

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
drivers/hv/hv_kvp.c | 396 +++++++++++++++++++++++++++-----------------
include/uapi/linux/hyperv.h | 8 +
tools/hv/hv_kvp_daemon.c | 187 ++++-----------------
3 files changed, 287 insertions(+), 304 deletions(-)

diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index beb8105..8078b1a 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -22,12 +22,16 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

-#include <linux/net.h>
#include <linux/nls.h>
-#include <linux/connector.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
#include <linux/workqueue.h>
+#include <linux/mutex.h>
#include <linux/hyperv.h>
+#include <linux/miscdevice.h>
+#include <linux/poll.h>

+#include <linux/uaccess.h>

/*
* Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
@@ -45,46 +49,41 @@
#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)

/*
- * Global state maintained for transaction that is being processed.
- * Note that only one transaction can be active at any point in time.
- *
- * This state is set when we receive a request from the host; we
- * cleanup this state when the transaction is completed - when we respond
- * to the host with the key value.
+ * Global state maintained for the device. Note that only one transaction can
+ * be active at any point in time.
*/

+enum kvp_device_state {
+ KVP_DEVICE_INITIALIZING = 0, /* driver was loaded */
+ KVP_DEVICE_OPENED, /* device was opened */
+ KVP_READY, /* userspace was registered */
+ KVP_HOSTMSG_RECEIVED, /* message from host was received */
+ KVP_USERMSG_READY, /* message for userspace is ready */
+ KVP_USERSPACE_REQ, /* request to userspace was sent */
+ KVP_USERSPACE_RECV, /* reply from userspace was received */
+ KVP_DEVICE_DYING, /* driver unload is in progress */
+};
+
static struct {
- bool active; /* transaction status - active or not */
+ int state; /* kvp_device_state */
int recv_len; /* number of bytes received. */
- struct hv_kvp_msg *kvp_msg; /* current message */
struct vmbus_channel *recv_channel; /* chn we got the request */
u64 recv_req_id; /* request ID. */
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 tracks
- * 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;
+ int dm_reg_value; /* daemon version number */
+ struct mutex lock; /* syncronization */
+ struct hv_kvp_msg user_msg; /* message to/from userspace */
+ struct hv_kvp_msg host_msg; /* message to/from host */
+ wait_queue_head_t proc_list; /* waiting processes */
+} kvp_device;

static void kvp_send_key(struct work_struct *dummy);
-
-
-static void kvp_respond_to_host(struct hv_kvp_msg *msg, int error);
+static void kvp_respond_to_host(int error);
static void kvp_work_func(struct work_struct *dummy);
-static void kvp_register(int);

static DECLARE_DELAYED_WORK(kvp_work, kvp_work_func);
static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);

-static struct cb_id kvp_id = { CN_KVP_IDX, CN_KVP_VAL };
static const char kvp_name[] = "kvp_kernel_module";
static u8 *recv_buffer;
/*
@@ -92,31 +91,8 @@ static u8 *recv_buffer;
* As part of this registration, pass the LIC version number.
* This number has no meaning, it satisfies the registration protocol.
*/
-#define HV_DRV_VERSION "3.1"
-
-static void
-kvp_register(int reg_value)
-{
-
- struct cn_msg *msg;
- struct hv_kvp_msg *kvp_msg;
- char *version;
-
- msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg), GFP_ATOMIC);
+#define HV_DRV_VERSION 31

- if (msg) {
- kvp_msg = (struct hv_kvp_msg *)msg->data;
- version = kvp_msg->body.kvp_register.version;
- msg->id.idx = CN_KVP_IDX;
- msg->id.val = CN_KVP_VAL;
-
- kvp_msg->kvp_hdr.operation = reg_value;
- strcpy(version, HV_DRV_VERSION);
- msg->len = sizeof(struct hv_kvp_msg);
- cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
- kfree(msg);
- }
-}
static void
kvp_work_func(struct work_struct *dummy)
{
@@ -124,7 +100,7 @@ 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(NULL, HV_E_FAIL);
+ kvp_respond_to_host(HV_E_FAIL);
}

static void poll_channel(struct vmbus_channel *channel)
@@ -138,36 +114,26 @@ static void poll_channel(struct vmbus_channel *channel)
}


-static int kvp_handle_handshake(struct hv_kvp_msg *msg)
+static int kvp_handle_handshake(u32 op)
{
- int ret = 1;
+ int ret = 0;

- switch (msg->kvp_hdr.operation) {
+ switch (op) {
case KVP_OP_REGISTER:
- dm_reg_value = KVP_OP_REGISTER;
+ kvp_device.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;
+ kvp_device.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;
+ KVP_OP_REGISTER1, op);
+ ret = 1;
}

- 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)
- poll_channel(kvp_transaction.kvp_context);
- }
return ret;
}

@@ -176,25 +142,11 @@ static int kvp_handle_handshake(struct hv_kvp_msg *msg)
* Callback when data is received from user mode.
*/

-static void
-kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
+static void kvp_userwrite_callback(void)
{
- struct hv_kvp_msg *message;
+ struct hv_kvp_msg *message = &kvp_device.user_msg;
struct hv_kvp_msg_enumerate *data;
- int error = 0;
-
- message = (struct hv_kvp_msg *)msg->data;
-
- /*
- * 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;
- }
+ int error = 0;

/*
* Based on the version of the daemon, we propagate errors from the
@@ -203,7 +155,7 @@ kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)

data = &message->body.kvp_enum_data;

- switch (dm_reg_value) {
+ switch (kvp_device.dm_reg_value) {
case KVP_OP_REGISTER:
/*
* Null string is used to pass back error condition.
@@ -226,10 +178,9 @@ kvp_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
* to the host. But first, cancel the timeout.
*/
if (cancel_delayed_work_sync(&kvp_work))
- kvp_respond_to_host(message, error);
+ kvp_respond_to_host(error);
}

-
static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
{
struct hv_kvp_msg *in = in_msg;
@@ -337,32 +288,21 @@ static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
}
}

-
-
-
static void
kvp_send_key(struct work_struct *dummy)
{
- struct cn_msg *msg;
- struct hv_kvp_msg *message;
- struct hv_kvp_msg *in_msg;
- __u8 operation = kvp_transaction.kvp_msg->kvp_hdr.operation;
- __u8 pool = kvp_transaction.kvp_msg->kvp_hdr.pool;
+ struct hv_kvp_msg *message = &kvp_device.user_msg;
+ struct hv_kvp_msg *in_msg = &kvp_device.host_msg;
+ __u8 operation = in_msg->kvp_hdr.operation;
+ __u8 pool = in_msg->kvp_hdr.pool;
__u32 val32;
__u64 val64;
- int rc;

- msg = kzalloc(sizeof(*msg) + sizeof(struct hv_kvp_msg) , GFP_ATOMIC);
- if (!msg)
- return;
-
- msg->id.idx = CN_KVP_IDX;
- msg->id.val = CN_KVP_VAL;
+ mutex_lock(&kvp_device.lock);

- message = (struct hv_kvp_msg *)msg->data;
+ memset(message, 0, sizeof(struct hv_kvp_msg));
message->kvp_hdr.operation = operation;
message->kvp_hdr.pool = pool;
- in_msg = kvp_transaction.kvp_msg;

/*
* The key/value strings sent from the host are encoded in
@@ -446,15 +386,10 @@ kvp_send_key(struct work_struct *dummy)
break;
}

- msg->len = sizeof(struct hv_kvp_msg);
- rc = cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
- if (rc) {
- pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
- if (cancel_delayed_work_sync(&kvp_work))
- kvp_respond_to_host(message, HV_E_FAIL);
- }
+ kvp_device.state = KVP_USERMSG_READY;
+ wake_up_interruptible(&kvp_device.proc_list);

- kfree(msg);
+ mutex_unlock(&kvp_device.lock);

return;
}
@@ -463,10 +398,10 @@ kvp_send_key(struct work_struct *dummy)
* Send a response back to the host.
*/

-static void
-kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
+static void kvp_respond_to_host(int error)
{
struct hv_kvp_msg *kvp_msg;
+ struct hv_kvp_msg *msg_to_host = &kvp_device.user_msg;
struct hv_kvp_exchg_msg_value *kvp_data;
char *key_name;
char *value;
@@ -479,26 +414,13 @@ kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
int ret;

/*
- * If a transaction is not active; log and return.
- */
-
- if (!kvp_transaction.active) {
- /*
- * This is a spurious call!
- */
- pr_warn("KVP: Transaction not active\n");
- return;
- }
- /*
* Copy the global state for completing the transaction. Note that
* only one transaction can be active at a time.
*/

- buf_len = kvp_transaction.recv_len;
- channel = kvp_transaction.recv_channel;
- req_id = kvp_transaction.recv_req_id;
-
- kvp_transaction.active = false;
+ buf_len = kvp_device.recv_len;
+ channel = kvp_device.recv_channel;
+ req_id = kvp_device.recv_req_id;

icmsghdrp = (struct icmsg_hdr *)
&recv_buffer[sizeof(struct vmbuspipe_hdr)];
@@ -528,7 +450,8 @@ kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
&recv_buffer[sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];

- switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
+
+ switch (kvp_device.host_msg.kvp_hdr.operation) {
case KVP_OP_GET_IP_INFO:
ret = process_ob_ipinfo(msg_to_host,
(struct hv_kvp_ip_msg *)kvp_msg,
@@ -586,6 +509,17 @@ response_done:

vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
VM_PKT_DATA_INBAND, 0);
+
+ /* We're ready to process next request, reset the device state */
+ if (kvp_device.state == KVP_USERSPACE_RECV ||
+ kvp_device.state == KVP_USERSPACE_REQ)
+ kvp_device.state = KVP_READY;
+ /*
+ * Make sure device state was set before polling the channel as
+ * processing can happen on a different CPU.
+ */
+ smp_mb();
+
poll_channel(channel);
}

@@ -612,14 +546,15 @@ void hv_kvp_onchannelcallback(void *context)
int util_fw_version;
int kvp_srv_version;

- if (kvp_transaction.active) {
+ if (kvp_device.state > KVP_READY) {
/*
* We will defer processing this callback once
* the current transaction is complete.
*/
- kvp_transaction.kvp_context = context;
+ kvp_device.kvp_context = channel;
return;
}
+ kvp_device.kvp_context = NULL;

vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
&requestid);
@@ -661,11 +596,19 @@ void hv_kvp_onchannelcallback(void *context)
* transaction; note transactions are serialized.
*/

- kvp_transaction.recv_len = recvlen;
- kvp_transaction.recv_channel = channel;
- kvp_transaction.recv_req_id = requestid;
- kvp_transaction.active = true;
- kvp_transaction.kvp_msg = kvp_msg;
+ kvp_device.recv_len = recvlen;
+ kvp_device.recv_channel = channel;
+ kvp_device.recv_req_id = requestid;
+
+ if (kvp_device.state != KVP_READY) {
+ /* Userspace daemon is not connected, fail. */
+ kvp_respond_to_host(HV_E_FAIL);
+ return;
+ }
+
+ kvp_device.state = KVP_HOSTMSG_RECEIVED;
+ memcpy(&kvp_device.host_msg, kvp_msg,
+ sizeof(struct hv_kvp_msg));

/*
* Get the information from the
@@ -690,17 +633,166 @@ void hv_kvp_onchannelcallback(void *context)
recvlen, requestid,
VM_PKT_DATA_INBAND, 0);
}
+}
+
+static int kvp_op_open(struct inode *inode, struct file *f)
+{
+ if (kvp_device.state != KVP_DEVICE_INITIALIZING)
+ return -EBUSY;
+ kvp_device.state = KVP_DEVICE_OPENED;
+ return 0;
+}
+
+static int kvp_op_release(struct inode *inode, struct file *f)
+{
+ kvp_device.state = KVP_DEVICE_INITIALIZING;
+ return 0;
+}
+
+static ssize_t kvp_op_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret = 0;
+
+ if (kvp_device.state == KVP_DEVICE_DYING)
+ return -EFAULT;
+
+ if (count != sizeof(struct hv_kvp_msg)) {
+ pr_warn("kvp_op_write: invalid write len: %d (expected: %d)\n",
+ (int)count, (int)sizeof(struct hv_kvp_msg));
+ return -EINVAL;
+ }

+ mutex_lock(&kvp_device.lock);
+
+ if (kvp_device.state == KVP_USERSPACE_REQ) {
+ if (!copy_from_user(&kvp_device.user_msg, buf,
+ sizeof(struct hv_kvp_msg))) {
+ kvp_device.state = KVP_USERSPACE_RECV;
+ kvp_userwrite_callback();
+ ret = sizeof(struct hv_kvp_msg);
+ } else
+ ret = -EFAULT;
+ } else {
+ pr_warn("kvp_op_write: invalid transaction state: %d\n",
+ kvp_device.state);
+ ret = -EINVAL;
+ }
+
+ mutex_unlock(&kvp_device.lock);
+ return ret;
}

+static ssize_t kvp_op_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t ret = 0;
+
+ if (kvp_device.state == KVP_DEVICE_DYING)
+ return -EFAULT;
+
+ if (count != sizeof(struct hv_kvp_msg)) {
+ pr_warn("kvp_op_read: invalid read len: %d (expected: %d)\n",
+ (int)count, (int)sizeof(struct hv_kvp_msg));
+ return -EINVAL;
+ }
+
+ if (wait_event_interruptible(kvp_device.proc_list,
+ kvp_device.state == KVP_USERMSG_READY ||
+ kvp_device.state == KVP_DEVICE_DYING))
+ return -EFAULT;
+
+ if (kvp_device.state != KVP_USERMSG_READY)
+ return -EFAULT;
+
+ mutex_lock(&kvp_device.lock);
+
+ if (!copy_to_user(buf, &kvp_device.user_msg,
+ sizeof(struct hv_kvp_msg))) {
+ kvp_device.state = KVP_USERSPACE_REQ;
+ ret = sizeof(struct hv_kvp_msg);
+ } else
+ ret = -EFAULT;
+
+ mutex_unlock(&kvp_device.lock);
+ return ret;
+}
+
+static unsigned int kvp_op_poll(struct file *file, poll_table *wait)
+{
+ if (kvp_device.state == KVP_DEVICE_DYING)
+ return -EFAULT;
+
+ poll_wait(file, &kvp_device.proc_list, wait);
+ if (kvp_device.state == KVP_USERMSG_READY)
+ return POLLIN | POLLRDNORM;
+ return 0;
+}
+
+static long kvp_op_ioctl(struct file *fp,
+ unsigned int cmd, unsigned long arg)
+{
+ long ret = 0;
+ void __user *argp = (void __user *)arg;
+ u32 val32;
+
+ if (kvp_device.state == KVP_DEVICE_DYING)
+ return -EFAULT;
+
+ /* The only ioctl we have is registation */
+ if (kvp_device.state != KVP_DEVICE_OPENED)
+ return -EINVAL;
+
+ mutex_lock(&kvp_device.lock);
+
+ switch (cmd) {
+ case HYPERV_KVP_REGISTER:
+ if (copy_from_user(&val32, argp, sizeof(val32))) {
+ ret = -EFAULT;
+ break;
+ }
+ if (!kvp_handle_handshake(val32)) {
+ val32 = (u32)HV_DRV_VERSION;
+ if (copy_to_user(argp, &val32, sizeof(val32))) {
+ ret = -EFAULT;
+ break;
+ }
+ kvp_device.state = KVP_READY;
+ pr_info("KVP: user-mode registering done.\n");
+ if (kvp_device.kvp_context)
+ poll_channel(kvp_device.kvp_context);
+ } else
+ ret = -EINVAL;
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&kvp_device.lock);
+ return ret;
+}
+
+static const struct file_operations kvp_fops = {
+ .owner = THIS_MODULE,
+ .read = kvp_op_read,
+ .write = kvp_op_write,
+ .release = kvp_op_release,
+ .open = kvp_op_open,
+ .poll = kvp_op_poll,
+ .unlocked_ioctl = kvp_op_ioctl
+};
+
+static struct miscdevice kvp_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "vmbus/hv_kvp",
+ .fops = &kvp_fops,
+};
+
int
hv_kvp_init(struct hv_util_service *srv)
{
- int err;
-
- err = cn_add_callback(&kvp_id, kvp_name, kvp_cn_callback);
- if (err)
- return err;
recv_buffer = srv->recv_buffer;

/*
@@ -709,14 +801,20 @@ hv_kvp_init(struct hv_util_service *srv)
* Defer processing channel callbacks until the daemon
* has registered.
*/
- kvp_transaction.active = true;
+ kvp_device.state = KVP_DEVICE_INITIALIZING;
+ init_waitqueue_head(&kvp_device.proc_list);
+ mutex_init(&kvp_device.lock);

- return 0;
+ return misc_register(&kvp_misc);
}

void hv_kvp_deinit(void)
{
- cn_del_callback(&kvp_id);
+ kvp_device.state = KVP_DEVICE_DYING;
+ /* Make sure nobody sees the old state */
+ smp_mb();
+ wake_up_interruptible(&kvp_device.proc_list);
cancel_delayed_work_sync(&kvp_work);
cancel_work_sync(&kvp_sendkey_work);
+ misc_deregister(&kvp_misc);
}
diff --git a/include/uapi/linux/hyperv.h b/include/uapi/linux/hyperv.h
index bb1cb73..80713a3 100644
--- a/include/uapi/linux/hyperv.h
+++ b/include/uapi/linux/hyperv.h
@@ -26,6 +26,7 @@
#define _UAPI_HYPERV_H

#include <linux/uuid.h>
+#include <linux/types.h>

/*
* Framework version for util services.
@@ -389,4 +390,11 @@ struct hv_kvp_ip_msg {
struct hv_kvp_ipaddr_value kvp_ip_val;
} __attribute__((packed));

+/*
+ * Userspace registration ioctls. Userspace daemons are supposed to pass their
+ * version as a parameter and get driver version back. KVP daemon supplies
+ * either KVP_OP_REGISTER or KVP_OP_REGISTER1.
+ */
+#define HYPERV_KVP_REGISTER _IOWR('v', 0, __u32)
+
#endif /* _UAPI_HYPERV_H */
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 408bb07..0c3cac7 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -33,7 +33,6 @@
#include <ctype.h>
#include <errno.h>
#include <arpa/inet.h>
-#include <linux/connector.h>
#include <linux/hyperv.h>
#include <linux/netlink.h>
#include <ifaddrs.h>
@@ -44,6 +43,7 @@
#include <dirent.h>
#include <net/if.h>
#include <getopt.h>
+#include <sys/ioctl.h>

/*
* KVP protocol: The user mode component first registers with the
@@ -79,9 +79,6 @@ enum {
DNS
};

-static struct sockaddr_nl addr;
-static int in_hand_shake = 1;
-
static char *os_name = "";
static char *os_major = "";
static char *os_minor = "";
@@ -1387,34 +1384,6 @@ kvp_get_domain_name(char *buffer, int length)
freeaddrinfo(info);
}

-static int
-netlink_send(int fd, struct cn_msg *msg)
-{
- struct nlmsghdr nlh = { .nlmsg_type = NLMSG_DONE };
- unsigned int size;
- struct msghdr message;
- struct iovec iov[2];
-
- size = sizeof(struct cn_msg) + msg->len;
-
- nlh.nlmsg_pid = getpid();
- nlh.nlmsg_len = NLMSG_LENGTH(size);
-
- iov[0].iov_base = &nlh;
- iov[0].iov_len = sizeof(nlh);
-
- iov[1].iov_base = msg;
- iov[1].iov_len = size;
-
- memset(&message, 0, sizeof(message));
- message.msg_name = &addr;
- message.msg_namelen = sizeof(addr);
- message.msg_iov = iov;
- message.msg_iovlen = 2;
-
- return sendmsg(fd, &message, 0);
-}
-
void print_usage(char *argv[])
{
fprintf(stderr, "Usage: %s [options]\n"
@@ -1425,23 +1394,18 @@ void print_usage(char *argv[])

int main(int argc, char *argv[])
{
- int fd, len, nl_group;
+ int kvp_fd, len;
int error;
- struct cn_msg *message;
struct pollfd pfd;
- struct nlmsghdr *incoming_msg;
- struct cn_msg *incoming_cn_msg;
- struct hv_kvp_msg *hv_msg;
- char *p;
+ struct hv_kvp_msg hv_msg[1];
char *key_value;
char *key_name;
int op;
int pool;
char *if_name;
struct hv_kvp_ipaddr_value *kvp_ip_val;
- char *kvp_recv_buffer;
- size_t kvp_recv_buffer_len;
int daemonize = 1, long_index = 0, opt;
+ __u32 daemon_ver = (__u32)KVP_OP_REGISTER1;

static struct option long_options[] = {
{"help", no_argument, 0, 'h' },
@@ -1468,12 +1432,14 @@ int main(int argc, char *argv[])
openlog("KVP", 0, LOG_USER);
syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());

- kvp_recv_buffer_len = NLMSG_LENGTH(0) + sizeof(struct cn_msg) + sizeof(struct hv_kvp_msg);
- kvp_recv_buffer = calloc(1, kvp_recv_buffer_len);
- if (!kvp_recv_buffer) {
- syslog(LOG_ERR, "Failed to allocate netlink buffer");
+ kvp_fd = open("/dev/vmbus/hv_kvp", O_RDWR);
+
+ if (kvp_fd < 0) {
+ syslog(LOG_ERR, "open /dev/vmbus/hv_kvp failed; error: %d %s",
+ errno, strerror(errno));
exit(EXIT_FAILURE);
}
+
/*
* Retrieve OS release information.
*/
@@ -1489,100 +1455,44 @@ int main(int argc, char *argv[])
exit(EXIT_FAILURE);
}

- fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
- if (fd < 0) {
- syslog(LOG_ERR, "netlink socket creation failed; error: %d %s", errno,
- strerror(errno));
- exit(EXIT_FAILURE);
- }
- addr.nl_family = AF_NETLINK;
- addr.nl_pad = 0;
- addr.nl_pid = 0;
- addr.nl_groups = 0;
-
-
- error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
- if (error < 0) {
- syslog(LOG_ERR, "bind failed; error: %d %s", errno, strerror(errno));
- close(fd);
- exit(EXIT_FAILURE);
- }
- nl_group = CN_KVP_IDX;
-
- if (setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &nl_group, sizeof(nl_group)) < 0) {
- syslog(LOG_ERR, "setsockopt failed; error: %d %s", errno, strerror(errno));
- close(fd);
- exit(EXIT_FAILURE);
- }
-
/*
* Register ourselves with the kernel.
*/
- message = (struct cn_msg *)kvp_recv_buffer;
- message->id.idx = CN_KVP_IDX;
- message->id.val = CN_KVP_VAL;
-
- hv_msg = (struct hv_kvp_msg *)message->data;
- hv_msg->kvp_hdr.operation = KVP_OP_REGISTER1;
- message->ack = 0;
- message->len = sizeof(struct hv_kvp_msg);
-
- len = netlink_send(fd, message);
- if (len < 0) {
- syslog(LOG_ERR, "netlink_send failed; error: %d %s", errno, strerror(errno));
- close(fd);
+ if (ioctl(kvp_fd, HYPERV_KVP_REGISTER, &daemon_ver)) {
+ syslog(LOG_ERR, "registration to kernel failed; error: %d %s",
+ errno, strerror(errno));
+ close(kvp_fd);
exit(EXIT_FAILURE);
}

- pfd.fd = fd;
+ syslog(LOG_INFO, "KVP LIC Version: %d", daemon_ver);
+
+ pfd.fd = kvp_fd;

while (1) {
- struct sockaddr *addr_p = (struct sockaddr *) &addr;
- socklen_t addr_l = sizeof(addr);
pfd.events = POLLIN;
pfd.revents = 0;

if (poll(&pfd, 1, -1) < 0) {
syslog(LOG_ERR, "poll failed; error: %d %s", errno, strerror(errno));
if (errno == EINVAL) {
- close(fd);
+ close(kvp_fd);
exit(EXIT_FAILURE);
}
else
continue;
}

- len = recvfrom(fd, kvp_recv_buffer, kvp_recv_buffer_len, 0,
- addr_p, &addr_l);
-
- if (len < 0) {
- int saved_errno = errno;
- syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
- addr.nl_pid, errno, strerror(errno));
-
- if (saved_errno == ENOBUFS) {
- syslog(LOG_ERR, "receive error: ignored");
- continue;
- }
+ len = read(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));

- close(fd);
- return -1;
- }
+ if (len != sizeof(struct hv_kvp_msg)) {
+ syslog(LOG_ERR, "read failed; error:%d %s",
+ errno, strerror(errno));

- if (addr.nl_pid) {
- syslog(LOG_WARNING, "Received packet from untrusted pid:%u",
- addr.nl_pid);
- continue;
+ close(kvp_fd);
+ return EXIT_FAILURE;
}

- incoming_msg = (struct nlmsghdr *)kvp_recv_buffer;
-
- if (incoming_msg->nlmsg_type != NLMSG_DONE)
- continue;
-
- incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg);
- hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
-
/*
* We will use the KVP header information to pass back
* the error from this daemon. So, first copy the state
@@ -1592,24 +1502,6 @@ int main(int argc, char *argv[])
pool = hv_msg->kvp_hdr.pool;
hv_msg->error = 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) {
- strcpy(lic_version, p);
- syslog(LOG_INFO, "KVP LIC Version: %s",
- lic_version);
- } else {
- syslog(LOG_ERR, "malloc failed");
- }
- continue;
- }
-
switch (op) {
case KVP_OP_GET_IP_INFO:
kvp_ip_val = &hv_msg->body.kvp_ip_val;
@@ -1702,7 +1594,6 @@ int main(int argc, char *argv[])
goto kvp_done;
}

- hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data;
key_name = (char *)hv_msg->body.kvp_enum_data.data.key;
key_value = (char *)hv_msg->body.kvp_enum_data.data.value;

@@ -1753,31 +1644,17 @@ int main(int argc, char *argv[])
hv_msg->error = HV_S_CONT;
break;
}
- /*
- * Send the value back to the kernel. The response is
- * already in the receive buffer. Update the cn_msg header to
- * reflect the key value that has been added to the message
- */
-kvp_done:
-
- incoming_cn_msg->id.idx = CN_KVP_IDX;
- incoming_cn_msg->id.val = CN_KVP_VAL;
- incoming_cn_msg->ack = 0;
- incoming_cn_msg->len = sizeof(struct hv_kvp_msg);
-
- len = netlink_send(fd, incoming_cn_msg);
- if (len < 0) {
- int saved_errno = errno;
- syslog(LOG_ERR, "net_link send failed; error: %d %s", errno,
- strerror(errno));
-
- if (saved_errno == ENOMEM || saved_errno == ENOBUFS) {
- syslog(LOG_ERR, "send error: ignored");
- continue;
- }

+ /* Send the value back to the kernel. */
+kvp_done:
+ len = write(kvp_fd, hv_msg, sizeof(struct hv_kvp_msg));
+ if (len != sizeof(struct hv_kvp_msg)) {
+ syslog(LOG_ERR, "write failed; error: %d %s", errno,
+ strerror(errno));
exit(EXIT_FAILURE);
}
}

+ close(kvp_fd);
+ exit(0);
}
--
1.9.3

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