The state machine in the hv_utils driver can run out of order in some
corner cases, e.g. if the kvp daemon doesn't call write() fast enough
due to some reason, kvp_timeout_func() can run first and move the state
to HVUTIL_READY; next, when kvp_on_msg() is called it returns -EINVAL
since kvp_transaction.state is smaller than HVUTIL_USERSPACE_REQ; later,
the daemon's write() gets an error -EINVAL, and the daemon will exit().

We can reproduce the issue by sending a SIGSTOP signal to the daemon, wait
for 1 minute, and send a SIGCONT signal to the daemon: the daemon will
exit() quickly.

We can fix the issue by forcing a reset of the device (which means the
daemon can close() and open() the device again) and doing extra necessary
clean-up.
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

When building hv_kvp_daemon GCC-8.3 complains:

hv_kvp_daemon.c: In function ‘kvp_get_ip_info.constprop’:
hv_kvp_daemon.c:812:30: warning: ‘ip_buffer’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  struct hv_kvp_ipaddr_value *ip_buffer;

this seems to be a false positive: we only use ip_buffer when
op == KVP_OP_GET_IP_INFO and it is only unset when op == KVP_OP_ENUMERATE.

Silence the warning by initializing ip_buffer to NULL.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

Fix typos in the HyperV toolchain.
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

HyperV KVP and VSS daemons should exit with 0 when the '--help'
or '-h' flags are used.
Signed-off-by: NAdrian Vladu <avladu@cloudbasesolutions.com>

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Alessandro Pilotti <apilotti@cloudbasesolutions.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

The patch fixes:

hv_kvp_daemon.c: In function 'kvp_set_ip_info':
hv_kvp_daemon.c:1305:2: note: 'snprintf' output between 41 and 4136 bytes
into a destination of size 4096

The "(unsigned int)str_len" is to avoid:

hv_kvp_daemon.c:1309:30: warning: comparison of integer expressions of
different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix a bug in the key delete code - the num_records range
from 0 to num_records-1.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reported-by: NDavid Binderman <dcb314@hotmail.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On Hyper-V the VF NIC has the same MAC as the related synthetic NIC.
VF NIC can work under the synthetic NIC transparently, without its
own IP address. The existing KVP daemon only gets IP from the first
NIC matching a MAC address, and may not be able to find the IP in
this case.

This patch fixes the problem by searching the NIC matching the MAC,
and having an IP address. So, the IP address will be found and
reported to the host successfully.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

While reading in more than one block (50) of KVP records, the allocation
goes per block, but the reads used the total number of allocated records
(without resetting the pointer/stream). This causes the records buffer to
overrun when the refresh reads more than one block over the previous
capacity (e.g. reading more than 100 KVP records whereas the in-memory
database was empty before).

Fix this by reading the correct number of KVP records from file each time.
Signed-off-by: NPaul Meyer <Paul.Meyer@microsoft.com>
Signed-off-by: NLong Li <longli@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Increase buffer size so that "_{-INT_MAX}" will fit.
Spotted by the gcc7 snprintf checker.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Paths can be up to PATH_MAX long and PATH_MAX is usually greater than 256.
While on it, simplify path reconstruction to a simple snprintf(), define
and reuse KVP_NET_DIR.
Suggested-by: NTomas Hozza <thozza@redhat.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

error when running hypervkvpd:
$ sudo ./hv_kvp_daemon -n

sh: hv_get_dns_info: command not found
sh: hv_get_dhcp_info: command not found
sh: hv_get_dns_info: command not found
sh: hv_get_dhcp_info: command not found

The external scripts are not installed in system path,
adding a configurable macro.
Signed-off-by: NAlex Fluter <afluter@yandex.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove unnecessary header files and netlink related code as the daemons
do not use netlink to communicate with the kernel now.
Signed-off-by: NWeibing Zhang <atheism.zhang@gmail.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hv_kvp_daemon.c: In function .kvp_mac_to_if_name.:
hv_kvp_daemon.c:705:2: warning: format not a string literal and no format arguments [-Wformat-security]
  snprintf(dev_id, sizeof(dev_id), kvp_net_dir);
  ^
hv_kvp_daemon.c:705:2: warning: format not a string literal and no format arguments [-Wformat-security]
Signed-off-by: NWeibing Zhang <atheism.zhang@gmail.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

KVP daemon does fork()/exec() (with popen()) so we need to close our fds
to avoid sharing them with child processes. The immediate implication of
not doing so I see is SELinux complaining about 'ip' trying to access
'/dev/vmbus/hv_kvp'.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use /dev/vmbus/hv_kvp instead of netlink.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch addresses two types of compiler warnings:
... warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
and
... warning: pointer targets in passing argument N of .kvp_.... differ in signedness [-Wpointer-sign]
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

fwrite() does not actually return the number of bytes written and
this value is being ignored anyway and ferror() is being called to
check for an error. As we assign to this variable and never use it
we get the following compile-time warning:
hv_kvp_daemon.c:149:9: warning: variable .bytes_written. set but not used [-Wunused-but-set-variable]
Remove bytes_written completely.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the case the host only injects an IPv6 address, the dhcp_enabled flag is
true (it's only for IPv4 according to Hyper-V host team), but we still need to
proceed to parse the IPv6 information.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Reviewed-By: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Under high memory pressure and very high KVP R/W test pressure, the netlink
recvfrom() may transiently return ENOBUFS to the daemon -- we found this
during a 2-week stress test.

We'd better not terminate the daemon on the failure, because a typical KVP
user will re-try the R/W and hopefully it will succeed next time.

We can also ignore the errors on sending.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Reviewed-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All tools/hv daemons do mandatory daemon() on startup. However, no pidfile
is created, this make it difficult for an init system to track such daemons.
Modern linux distros use systemd as their init system. It can handle the
daemonizing by itself, however, it requires a daemon to stay in foreground
for that. Some distros already carry distro-specific patch for hv tools
which switches off daemon().

Introduce -n/--no-daemon option for all 3 daemons in hv/tools. Parse options
with getopt() to make this part easily expandable.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With very old libc headers the inclusion of sys/types.h causes conflicts
with linux/types.h. Since the latter is not required anyway, remove it
from the source files. If any of the headers really needs linux/types.h
it has to include it itself.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

send_buffer is used only once during registration. To reduce runtime
memory usage reuse the recv_buffer for registration. Also use
NLMSG_LENGTH instead of NLMSG_HDRLEN to take alignment into account.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

kvp_daemon does some operations which take an unpredicable amount of
time. In addition the kernel driver gives the kvp_daemon a 5 second
timeout to respond to message from the host. If an operation such as
getaddrinfo takes a long time and the timeout triggers then netlink
errors occour. As a result of such errors the daemon just terminates and
the service becomes unavailable.

Idendifying and fixing these shortcomings in the kernel-userland
communication protocol will be done in separate patches. This change
fixes just one obvious timeout bug.

Update kvp_get_domain_name to not return a value, better diagnostic for
the consumer of the hostname string, remove trailing newline in error
case, use snprintf to not overrun output buffer, get hostname only once
and return the cached result.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need to have a nlmsghdr pointer to another temporary buffer.
Instead use a full struct nlmsghdr.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

netlink_send is supposed to send just the cn_msg+hv_kvp_msg via netlink.
Currently it sets an incorrect iovec size, as reported by valgrind.

In the case of registering with the kernel the allocated buffer is large
enough to hold nlmsghdr+cn_msg+hv_kvp_msg, no overrun happens. In the
case of responding to the kernel the cn_msg is located in the middle of
recv_buffer, after the nlmsghdr. Currently the code in netlink_send adds
also the size of nlmsghdr to the payload. But nlmsghdr is a separate
iovec. This leads to an (harmless) out-of-bounds access when the kernel
processes the iovec. Correct the iovec size of the cn_msg to be just
cn_msg + its payload.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hv_kvp_daemon.c: In function 'main':
hv_kvp_daemon.c:1441:8: warning: ignoring return value of 'daemon', declared with attribute warn_unused_result [-Wunused-result]
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

... to simplify error path in upcoming changes.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hv_kvp_daemon.c: In function 'main':
hv_kvp_daemon.c:1441:8: warning: ignoring return value of 'daemon', declared with attribute warn_unused_result [-Wunused-result]
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hv_kvp_daemon fails to start in current openSuSE 13.1 snapshots because
the kvp_send_buffer is too small to hold cn_msg+hv_kvp_msg, the very
first sendmsg returns with EFAULT. In addition it fixes the Network info
tab in Windows Server 2012R2 in SLES11.

Adjust the code in kvp and vss daemon to allocate the needed buffers at
runtime. To keep the code simple, the buffer_len includes also the
nlmsghdr, although only the recv_buffer needs this extra space.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Each subnet string needs to be separated with a semicolon. Fix this bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use errno and strerror() when logging errors to provide
more information.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Close "fd" file descriptor when is goes out of scope so it does
not leak.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check return value of strchr call and dereference it only if it is
not NULL.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check return value of poll call and if it fails print error
to the system log. If errno is EINVAL then exit with non-zero
value otherwise continue the while loop and call poll again.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check return value of setsockopt call and if it fails print error
to the system log and exit with non-zero value.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

HyperV KVP daemon should check nlmsg_type in received netlink message
header. If message type is NLMSG_DONE daemon can proceed with processing
otherwise it should wait for next message.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

HyperV daemon should use macros for option values when calling setsockopt.
Using specific numeric values instead of macros is confusing.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Previously HyperV daemon set sockaddr_nl.nl_groups to CN_KVP_IDX.
Netlink documentation says: "nl_groups is a bit mask with every bit
representing a netlink group number". Since CN_KVP_IDX value is "9"
HyperV daemon was receiving Netlink messages also from group number
"1" which is used by CGroup Rules Engine Daemon. This caused the
daemon to segfault (at least on 2.6.32 kernel).

HyperV daemon should set nl_groups to zero and specify multicast
group CN_KVP_IDX only by using socket options.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use CLOEXEC flag when opening kvp_pool_x files to prevent file
descriptor leakage. Not using it was causing a problem when
SELinux was enabled.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix for the daemon code and for hv_set_ifconfig.sh script, so
that the created ifcfg-* file is consistent with initscripts
documentation.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>