OpenCloudOS-Kernel/drivers/hv/hv_kvp.c

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/*
* An implementation of key value pair (KVP) functionality for Linux.
*
*
* Copyright (C) 2010, Novell, Inc.
* Author : K. Y. Srinivasan <ksrinivasan@novell.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/net.h>
#include <linux/nls.h>
#include <linux/connector.h>
#include <linux/workqueue.h>
#include <linux/hyperv.h>
#include <asm/hyperv-tlfs.h>
#include "hyperv_vmbus.h"
#include "hv_utils_transport.h"
/*
* Pre win8 version numbers used in ws2008 and ws 2008 r2 (win7)
*/
#define WS2008_SRV_MAJOR 1
#define WS2008_SRV_MINOR 0
#define WS2008_SRV_VERSION (WS2008_SRV_MAJOR << 16 | WS2008_SRV_MINOR)
#define WIN7_SRV_MAJOR 3
#define WIN7_SRV_MINOR 0
#define WIN7_SRV_VERSION (WIN7_SRV_MAJOR << 16 | WIN7_SRV_MINOR)
#define WIN8_SRV_MAJOR 4
#define WIN8_SRV_MINOR 0
#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
#define KVP_VER_COUNT 3
static const int kvp_versions[] = {
WIN8_SRV_VERSION,
WIN7_SRV_VERSION,
WS2008_SRV_VERSION
};
#define FW_VER_COUNT 2
static const int fw_versions[] = {
UTIL_FW_VERSION,
UTIL_WS2K8_FW_VERSION
};
/*
* Global state maintained for transaction that is being processed. For a class
* of integration services, including the "KVP service", the specified protocol
* is a "request/response" protocol which means that there can only be single
* outstanding transaction from the host at any given point in time. We use
* this to simplify memory management in this driver - we cache and process
* only one message at a time.
*
* While the request/response protocol is guaranteed by the host, we further
* ensure this by serializing packet processing in this driver - we do not
* read additional packets from the VMBUS until the current packet is fully
* handled.
*/
static struct {
int state; /* hvutil_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. */
} kvp_transaction;
/*
* This state maintains the version number registered by the daemon.
*/
static int dm_reg_value;
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_timeout_func(struct work_struct *dummy);
static void kvp_host_handshake_func(struct work_struct *dummy);
static void kvp_register(int);
static DECLARE_DELAYED_WORK(kvp_timeout_work, kvp_timeout_func);
static DECLARE_DELAYED_WORK(kvp_host_handshake_work, kvp_host_handshake_func);
static DECLARE_WORK(kvp_sendkey_work, kvp_send_key);
static const char kvp_devname[] = "vmbus/hv_kvp";
static u8 *recv_buffer;
static struct hvutil_transport *hvt;
/*
* Register the kernel component with the user-level daemon.
* 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_poll_wrapper(void *channel)
{
/* Transaction is finished, reset the state here to avoid races. */
kvp_transaction.state = HVUTIL_READY;
tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event);
}
Drivers: hv: utils: fix a race on userspace daemons registration Background: userspace daemons registration protocol for Hyper-V utilities drivers has two steps: 1) daemon writes its own version to kernel 2) kernel reads it and replies with module version at this point we consider the handshake procedure being completed and we do hv_poll_channel() transitioning the utility device to HVUTIL_READY state. At this point we're ready to handle messages from kernel. When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a single buffer for outgoing message. hvutil_transport_send() puts to this buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT to all consequent calls. Host<->guest protocol guarantees there is no more than one request at a time and we will not get new requests till we reply to the previous one so this single message buffer is enough. Now to the race. When we finish negotiation procedure and send kernel module version to userspace with hvutil_transport_send() it goes into the above mentioned buffer and if the daemon is slow enough to read it from there we can get a collision when a request from the host comes, we won't be able to put anything to the buffer so the request will be lost. To solve the issue we need to know when the negotiation is really done (when the version message is read by the daemon) and transition to HVUTIL_READY state after this happens. Implement a callback on read to support this. Old style netlink communication is not affected by the change, we don't really know when these messages are delivered but we don't have a single message buffer there. Reported-by: Barry Davis <barry_davis@stormagic.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-10 08:08:57 +08:00
static void kvp_register_done(void)
{
/*
* If we're still negotiating with the host cancel the timeout
* work to not poll the channel twice.
*/
pr_debug("KVP: userspace daemon registered\n");
cancel_delayed_work_sync(&kvp_host_handshake_work);
hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}
static void
kvp_register(int reg_value)
{
struct hv_kvp_msg *kvp_msg;
char *version;
kvp_msg = kzalloc(sizeof(*kvp_msg), GFP_KERNEL);
if (kvp_msg) {
version = kvp_msg->body.kvp_register.version;
kvp_msg->kvp_hdr.operation = reg_value;
strcpy(version, HV_DRV_VERSION);
Drivers: hv: utils: fix a race on userspace daemons registration Background: userspace daemons registration protocol for Hyper-V utilities drivers has two steps: 1) daemon writes its own version to kernel 2) kernel reads it and replies with module version at this point we consider the handshake procedure being completed and we do hv_poll_channel() transitioning the utility device to HVUTIL_READY state. At this point we're ready to handle messages from kernel. When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a single buffer for outgoing message. hvutil_transport_send() puts to this buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT to all consequent calls. Host<->guest protocol guarantees there is no more than one request at a time and we will not get new requests till we reply to the previous one so this single message buffer is enough. Now to the race. When we finish negotiation procedure and send kernel module version to userspace with hvutil_transport_send() it goes into the above mentioned buffer and if the daemon is slow enough to read it from there we can get a collision when a request from the host comes, we won't be able to put anything to the buffer so the request will be lost. To solve the issue we need to know when the negotiation is really done (when the version message is read by the daemon) and transition to HVUTIL_READY state after this happens. Implement a callback on read to support this. Old style netlink communication is not affected by the change, we don't really know when these messages are delivered but we don't have a single message buffer there. Reported-by: Barry Davis <barry_davis@stormagic.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-10 08:08:57 +08:00
hvutil_transport_send(hvt, kvp_msg, sizeof(*kvp_msg),
kvp_register_done);
kfree(kvp_msg);
}
}
static void kvp_timeout_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);
hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}
static void kvp_host_handshake_func(struct work_struct *dummy)
{
tasklet_schedule(&kvp_transaction.recv_channel->callback_event);
}
static int kvp_handle_handshake(struct hv_kvp_msg *msg)
{
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);
return -EINVAL;
}
/*
* We have a compatible daemon; complete the handshake.
*/
Drivers: hv: utils: fix a race on userspace daemons registration Background: userspace daemons registration protocol for Hyper-V utilities drivers has two steps: 1) daemon writes its own version to kernel 2) kernel reads it and replies with module version at this point we consider the handshake procedure being completed and we do hv_poll_channel() transitioning the utility device to HVUTIL_READY state. At this point we're ready to handle messages from kernel. When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a single buffer for outgoing message. hvutil_transport_send() puts to this buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT to all consequent calls. Host<->guest protocol guarantees there is no more than one request at a time and we will not get new requests till we reply to the previous one so this single message buffer is enough. Now to the race. When we finish negotiation procedure and send kernel module version to userspace with hvutil_transport_send() it goes into the above mentioned buffer and if the daemon is slow enough to read it from there we can get a collision when a request from the host comes, we won't be able to put anything to the buffer so the request will be lost. To solve the issue we need to know when the negotiation is really done (when the version message is read by the daemon) and transition to HVUTIL_READY state after this happens. Implement a callback on read to support this. Old style netlink communication is not affected by the change, we don't really know when these messages are delivered but we don't have a single message buffer there. Reported-by: Barry Davis <barry_davis@stormagic.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-10 08:08:57 +08:00
pr_debug("KVP: userspace daemon ver. %d connected\n",
msg->kvp_hdr.operation);
kvp_register(dm_reg_value);
return 0;
}
/*
* Callback when data is received from user mode.
*/
static int kvp_on_msg(void *msg, int len)
{
struct hv_kvp_msg *message = (struct hv_kvp_msg *)msg;
struct hv_kvp_msg_enumerate *data;
int error = 0;
if (len < sizeof(*message))
return -EINVAL;
/*
* If we are negotiating the version information
* with the daemon; handle that first.
*/
if (kvp_transaction.state < HVUTIL_READY) {
return kvp_handle_handshake(message);
}
/* We didn't send anything to userspace so the reply is spurious */
if (kvp_transaction.state < HVUTIL_USERSPACE_REQ)
return -EINVAL;
kvp_transaction.state = HVUTIL_USERSPACE_RECV;
/*
* 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:
/*
* Null string is used to pass back error condition.
*/
if (data->data.key[0] == 0)
error = HV_S_CONT;
break;
case KVP_OP_REGISTER1:
/*
* We use the message header information from
* the user level daemon to transmit errors.
*/
error = message->error;
break;
}
/*
* Complete the transaction by forwarding the key value
* to the host. But first, cancel the timeout.
*/
if (cancel_delayed_work_sync(&kvp_timeout_work)) {
kvp_respond_to_host(message, error);
hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}
return 0;
}
static int process_ob_ipinfo(void *in_msg, void *out_msg, int op)
{
struct hv_kvp_msg *in = in_msg;
struct hv_kvp_ip_msg *out = out_msg;
int len;
switch (op) {
case KVP_OP_GET_IP_INFO:
/*
* Transform all parameters into utf16 encoding.
*/
len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.ip_addr,
strlen((char *)in->body.kvp_ip_val.ip_addr),
UTF16_HOST_ENDIAN,
(wchar_t *)out->kvp_ip_val.ip_addr,
MAX_IP_ADDR_SIZE);
if (len < 0)
return len;
len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.sub_net,
strlen((char *)in->body.kvp_ip_val.sub_net),
UTF16_HOST_ENDIAN,
(wchar_t *)out->kvp_ip_val.sub_net,
MAX_IP_ADDR_SIZE);
if (len < 0)
return len;
len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.gate_way,
strlen((char *)in->body.kvp_ip_val.gate_way),
UTF16_HOST_ENDIAN,
(wchar_t *)out->kvp_ip_val.gate_way,
MAX_GATEWAY_SIZE);
if (len < 0)
return len;
len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.dns_addr,
strlen((char *)in->body.kvp_ip_val.dns_addr),
UTF16_HOST_ENDIAN,
(wchar_t *)out->kvp_ip_val.dns_addr,
MAX_IP_ADDR_SIZE);
if (len < 0)
return len;
len = utf8s_to_utf16s((char *)in->body.kvp_ip_val.adapter_id,
strlen((char *)in->body.kvp_ip_val.adapter_id),
UTF16_HOST_ENDIAN,
(wchar_t *)out->kvp_ip_val.adapter_id,
MAX_ADAPTER_ID_SIZE);
if (len < 0)
return len;
out->kvp_ip_val.dhcp_enabled =
in->body.kvp_ip_val.dhcp_enabled;
out->kvp_ip_val.addr_family =
in->body.kvp_ip_val.addr_family;
}
return 0;
}
static void process_ib_ipinfo(void *in_msg, void *out_msg, int op)
{
struct hv_kvp_ip_msg *in = in_msg;
struct hv_kvp_msg *out = out_msg;
switch (op) {
case KVP_OP_SET_IP_INFO:
/*
* Transform all parameters into utf8 encoding.
*/
utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.ip_addr,
MAX_IP_ADDR_SIZE,
UTF16_LITTLE_ENDIAN,
(__u8 *)out->body.kvp_ip_val.ip_addr,
MAX_IP_ADDR_SIZE);
utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.sub_net,
MAX_IP_ADDR_SIZE,
UTF16_LITTLE_ENDIAN,
(__u8 *)out->body.kvp_ip_val.sub_net,
MAX_IP_ADDR_SIZE);
utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.gate_way,
MAX_GATEWAY_SIZE,
UTF16_LITTLE_ENDIAN,
(__u8 *)out->body.kvp_ip_val.gate_way,
MAX_GATEWAY_SIZE);
utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.dns_addr,
MAX_IP_ADDR_SIZE,
UTF16_LITTLE_ENDIAN,
(__u8 *)out->body.kvp_ip_val.dns_addr,
MAX_IP_ADDR_SIZE);
out->body.kvp_ip_val.dhcp_enabled = in->kvp_ip_val.dhcp_enabled;
fallthrough;
case KVP_OP_GET_IP_INFO:
utf16s_to_utf8s((wchar_t *)in->kvp_ip_val.adapter_id,
MAX_ADAPTER_ID_SIZE,
UTF16_LITTLE_ENDIAN,
(__u8 *)out->body.kvp_ip_val.adapter_id,
MAX_ADAPTER_ID_SIZE);
out->body.kvp_ip_val.addr_family = in->kvp_ip_val.addr_family;
}
}
static void
kvp_send_key(struct work_struct *dummy)
{
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;
__u32 val32;
__u64 val64;
int rc;
/* The transaction state is wrong. */
if (kvp_transaction.state != HVUTIL_HOSTMSG_RECEIVED)
return;
message = kzalloc(sizeof(*message), GFP_KERNEL);
if (!message)
return;
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
* in utf16; convert it to utf8 strings.
* The host assures us that the utf16 strings will not exceed
* the max lengths specified. We will however, reserve room
* for the string terminating character - in the utf16s_utf8s()
* function we limit the size of the buffer where the converted
* string is placed to HV_KVP_EXCHANGE_MAX_*_SIZE -1 to guarantee
* that the strings can be properly terminated!
*/
switch (message->kvp_hdr.operation) {
case KVP_OP_SET_IP_INFO:
process_ib_ipinfo(in_msg, message, KVP_OP_SET_IP_INFO);
break;
case KVP_OP_GET_IP_INFO:
/*
* We only need to pass on the info of operation, adapter_id
* and addr_family to the userland kvp daemon.
*/
process_ib_ipinfo(in_msg, message, KVP_OP_GET_IP_INFO);
break;
case KVP_OP_SET:
switch (in_msg->body.kvp_set.data.value_type) {
case REG_SZ:
/*
* The value is a string - utf16 encoding.
*/
message->body.kvp_set.data.value_size =
utf16s_to_utf8s(
(wchar_t *)in_msg->body.kvp_set.data.value,
in_msg->body.kvp_set.data.value_size,
UTF16_LITTLE_ENDIAN,
message->body.kvp_set.data.value,
HV_KVP_EXCHANGE_MAX_VALUE_SIZE - 1) + 1;
break;
case REG_U32:
/*
* The value is a 32 bit scalar.
* We save this as a utf8 string.
*/
val32 = in_msg->body.kvp_set.data.value_u32;
message->body.kvp_set.data.value_size =
sprintf(message->body.kvp_set.data.value,
"%u", val32) + 1;
break;
case REG_U64:
/*
* The value is a 64 bit scalar.
* We save this as a utf8 string.
*/
val64 = in_msg->body.kvp_set.data.value_u64;
message->body.kvp_set.data.value_size =
sprintf(message->body.kvp_set.data.value,
"%llu", val64) + 1;
break;
}
/*
* The key is always a string - utf16 encoding.
*/
message->body.kvp_set.data.key_size =
utf16s_to_utf8s(
(wchar_t *)in_msg->body.kvp_set.data.key,
in_msg->body.kvp_set.data.key_size,
UTF16_LITTLE_ENDIAN,
message->body.kvp_set.data.key,
HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
break;
case KVP_OP_GET:
message->body.kvp_get.data.key_size =
utf16s_to_utf8s(
(wchar_t *)in_msg->body.kvp_get.data.key,
in_msg->body.kvp_get.data.key_size,
UTF16_LITTLE_ENDIAN,
message->body.kvp_get.data.key,
HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
break;
case KVP_OP_DELETE:
message->body.kvp_delete.key_size =
utf16s_to_utf8s(
(wchar_t *)in_msg->body.kvp_delete.key,
in_msg->body.kvp_delete.key_size,
UTF16_LITTLE_ENDIAN,
message->body.kvp_delete.key,
HV_KVP_EXCHANGE_MAX_KEY_SIZE - 1) + 1;
break;
case KVP_OP_ENUMERATE:
message->body.kvp_enum_data.index =
in_msg->body.kvp_enum_data.index;
break;
}
kvp_transaction.state = HVUTIL_USERSPACE_REQ;
Drivers: hv: utils: fix a race on userspace daemons registration Background: userspace daemons registration protocol for Hyper-V utilities drivers has two steps: 1) daemon writes its own version to kernel 2) kernel reads it and replies with module version at this point we consider the handshake procedure being completed and we do hv_poll_channel() transitioning the utility device to HVUTIL_READY state. At this point we're ready to handle messages from kernel. When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a single buffer for outgoing message. hvutil_transport_send() puts to this buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT to all consequent calls. Host<->guest protocol guarantees there is no more than one request at a time and we will not get new requests till we reply to the previous one so this single message buffer is enough. Now to the race. When we finish negotiation procedure and send kernel module version to userspace with hvutil_transport_send() it goes into the above mentioned buffer and if the daemon is slow enough to read it from there we can get a collision when a request from the host comes, we won't be able to put anything to the buffer so the request will be lost. To solve the issue we need to know when the negotiation is really done (when the version message is read by the daemon) and transition to HVUTIL_READY state after this happens. Implement a callback on read to support this. Old style netlink communication is not affected by the change, we don't really know when these messages are delivered but we don't have a single message buffer there. Reported-by: Barry Davis <barry_davis@stormagic.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-10 08:08:57 +08:00
rc = hvutil_transport_send(hvt, message, sizeof(*message), NULL);
if (rc) {
pr_debug("KVP: failed to communicate to the daemon: %d\n", rc);
if (cancel_delayed_work_sync(&kvp_timeout_work)) {
kvp_respond_to_host(message, HV_E_FAIL);
kvp_transaction.state = HVUTIL_READY;
}
}
kfree(message);
}
/*
* Send a response back to the host.
*/
static void
kvp_respond_to_host(struct hv_kvp_msg *msg_to_host, int error)
{
struct hv_kvp_msg *kvp_msg;
struct hv_kvp_exchg_msg_value *kvp_data;
char *key_name;
char *value;
struct icmsg_hdr *icmsghdrp;
int keylen = 0;
int valuelen = 0;
u32 buf_len;
struct vmbus_channel *channel;
u64 req_id;
int ret;
/*
* 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;
icmsghdrp = (struct icmsg_hdr *)
&recv_buffer[sizeof(struct vmbuspipe_hdr)];
if (channel->onchannel_callback == NULL)
/*
* We have raced with util driver being unloaded;
* silently return.
*/
return;
icmsghdrp->status = error;
/*
* If the error parameter is set, terminate the host's enumeration
* on this pool.
*/
if (error) {
/*
* Something failed or we have timed out;
* terminate the current host-side iteration.
*/
goto response_done;
}
kvp_msg = (struct hv_kvp_msg *)
&recv_buffer[sizeof(struct vmbuspipe_hdr) +
sizeof(struct icmsg_hdr)];
switch (kvp_transaction.kvp_msg->kvp_hdr.operation) {
case KVP_OP_GET_IP_INFO:
ret = process_ob_ipinfo(msg_to_host,
(struct hv_kvp_ip_msg *)kvp_msg,
KVP_OP_GET_IP_INFO);
if (ret < 0)
icmsghdrp->status = HV_E_FAIL;
goto response_done;
case KVP_OP_SET_IP_INFO:
goto response_done;
case KVP_OP_GET:
kvp_data = &kvp_msg->body.kvp_get.data;
goto copy_value;
case KVP_OP_SET:
case KVP_OP_DELETE:
goto response_done;
default:
break;
}
kvp_data = &kvp_msg->body.kvp_enum_data.data;
key_name = msg_to_host->body.kvp_enum_data.data.key;
/*
* The windows host expects the key/value pair to be encoded
* in utf16. Ensure that the key/value size reported to the host
* will be less than or equal to the MAX size (including the
* terminating character).
*/
keylen = utf8s_to_utf16s(key_name, strlen(key_name), UTF16_HOST_ENDIAN,
(wchar_t *) kvp_data->key,
(HV_KVP_EXCHANGE_MAX_KEY_SIZE / 2) - 2);
kvp_data->key_size = 2*(keylen + 1); /* utf16 encoding */
copy_value:
value = msg_to_host->body.kvp_enum_data.data.value;
valuelen = utf8s_to_utf16s(value, strlen(value), UTF16_HOST_ENDIAN,
(wchar_t *) kvp_data->value,
(HV_KVP_EXCHANGE_MAX_VALUE_SIZE / 2) - 2);
kvp_data->value_size = 2*(valuelen + 1); /* utf16 encoding */
/*
* If the utf8s to utf16s conversion failed; notify host
* of the error.
*/
if ((keylen < 0) || (valuelen < 0))
icmsghdrp->status = HV_E_FAIL;
kvp_data->value_type = REG_SZ; /* all our values are strings */
response_done:
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
VM_PKT_DATA_INBAND, 0);
}
/*
* This callback is invoked when we get a KVP message from the host.
* The host ensures that only one KVP transaction can be active at a time.
* KVP implementation in Linux needs to forward the key to a user-mde
* component to retrieve the corresponding value. Consequently, we cannot
* respond to the host in the context of this callback. Since the host
* guarantees that at most only one transaction can be active at a time,
* we stash away the transaction state in a set of global variables.
*/
void hv_kvp_onchannelcallback(void *context)
{
struct vmbus_channel *channel = context;
u32 recvlen;
u64 requestid;
struct hv_kvp_msg *kvp_msg;
struct icmsg_hdr *icmsghdrp;
int kvp_srv_version;
static enum {NEGO_NOT_STARTED,
NEGO_IN_PROGRESS,
NEGO_FINISHED} host_negotiatied = NEGO_NOT_STARTED;
if (kvp_transaction.state < HVUTIL_READY) {
/*
* If userspace daemon is not connected and host is asking
* us to negotiate we need to delay to not lose messages.
* This is important for Failover IP setting.
*/
if (host_negotiatied == NEGO_NOT_STARTED) {
host_negotiatied = NEGO_IN_PROGRESS;
schedule_delayed_work(&kvp_host_handshake_work,
HV_UTIL_NEGO_TIMEOUT * HZ);
}
return;
}
if (kvp_transaction.state > HVUTIL_READY)
return;
if (vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 4, &recvlen, &requestid)) {
pr_err_ratelimited("KVP request received. Could not read into recv buf\n");
return;
}
if (!recvlen)
return;
/* Ensure recvlen is big enough to read header data */
if (recvlen < ICMSG_HDR) {
pr_err_ratelimited("KVP request received. Packet length too small: %d\n",
recvlen);
return;
}
icmsghdrp = (struct icmsg_hdr *)&recv_buffer[sizeof(struct vmbuspipe_hdr)];
if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
if (vmbus_prep_negotiate_resp(icmsghdrp,
recv_buffer, recvlen,
fw_versions, FW_VER_COUNT,
kvp_versions, KVP_VER_COUNT,
NULL, &kvp_srv_version)) {
pr_info("KVP IC version %d.%d\n",
kvp_srv_version >> 16,
kvp_srv_version & 0xFFFF);
}
} else if (icmsghdrp->icmsgtype == ICMSGTYPE_KVPEXCHANGE) {
/*
* recvlen is not checked against sizeof(struct kvp_msg) because kvp_msg contains
* a union of structs and the msg type received is not known. Code using this
* struct should provide validation when accessing its fields.
*/
kvp_msg = (struct hv_kvp_msg *)&recv_buffer[ICMSG_HDR];
/*
* Stash away this global state for completing the
* transaction; note transactions are serialized.
*/
kvp_transaction.recv_len = recvlen;
kvp_transaction.recv_req_id = requestid;
kvp_transaction.kvp_msg = kvp_msg;
if (kvp_transaction.state < HVUTIL_READY) {
/* Userspace is not registered yet */
kvp_respond_to_host(NULL, HV_E_FAIL);
return;
}
kvp_transaction.state = HVUTIL_HOSTMSG_RECEIVED;
/*
* Get the information from the
* user-mode component.
* component. This transaction will be
* completed when we get the value from
* the user-mode component.
* Set a timeout to deal with
* user-mode not responding.
*/
schedule_work(&kvp_sendkey_work);
schedule_delayed_work(&kvp_timeout_work,
HV_UTIL_TIMEOUT * HZ);
return;
} else {
pr_err_ratelimited("KVP request received. Invalid msg type: %d\n",
icmsghdrp->icmsgtype);
return;
}
icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE;
vmbus_sendpacket(channel, recv_buffer,
recvlen, requestid,
VM_PKT_DATA_INBAND, 0);
host_negotiatied = NEGO_FINISHED;
hv_poll_channel(kvp_transaction.recv_channel, kvp_poll_wrapper);
}
static void kvp_on_reset(void)
{
if (cancel_delayed_work_sync(&kvp_timeout_work))
kvp_respond_to_host(NULL, HV_E_FAIL);
kvp_transaction.state = HVUTIL_DEVICE_INIT;
}
int
hv_kvp_init(struct hv_util_service *srv)
{
recv_buffer = srv->recv_buffer;
kvp_transaction.recv_channel = srv->channel;
kvp_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 4;
/*
* When this driver loads, the user level daemon that
* processes the host requests may not yet be running.
* Defer processing channel callbacks until the daemon
* has registered.
*/
kvp_transaction.state = HVUTIL_DEVICE_INIT;
hvt = hvutil_transport_init(kvp_devname, CN_KVP_IDX, CN_KVP_VAL,
kvp_on_msg, kvp_on_reset);
if (!hvt)
return -EFAULT;
return 0;
}
static void hv_kvp_cancel_work(void)
{
cancel_delayed_work_sync(&kvp_host_handshake_work);
cancel_delayed_work_sync(&kvp_timeout_work);
cancel_work_sync(&kvp_sendkey_work);
}
int hv_kvp_pre_suspend(void)
{
struct vmbus_channel *channel = kvp_transaction.recv_channel;
tasklet_disable(&channel->callback_event);
/*
* If there is a pending transtion, it's unnecessary to tell the host
* that the transaction will fail, because that is implied when
* util_suspend() calls vmbus_close() later.
*/
hv_kvp_cancel_work();
/*
* Forece the state to READY to handle the ICMSGTYPE_NEGOTIATE message
* later. The user space daemon may go out of order and its write()
* may fail with EINVAL: this doesn't matter since the daemon will
* reset the device by closing and re-opening it.
*/
kvp_transaction.state = HVUTIL_READY;
return 0;
}
int hv_kvp_pre_resume(void)
{
struct vmbus_channel *channel = kvp_transaction.recv_channel;
tasklet_enable(&channel->callback_event);
return 0;
}
void hv_kvp_deinit(void)
{
kvp_transaction.state = HVUTIL_DEVICE_DYING;
hv_kvp_cancel_work();
hvutil_transport_destroy(hvt);
}