Don't rely on random source port of a connected socket alone as a
protection against spoofed packets in chronyc. Generate a fully random
32-bit sequence number for each request and modify the code to not send
a new request until the timeout expires or a valid response is received.
For a monitoring protocol this should be more than good enough.
Add xleave option to the peer directive to enable an interleaved mode
compatible with ntpd. This allows peers to exchange transmit timestamps
captured after the actual transmission and significantly improve
the accuracy of the measurements.
Replace struct timeval with struct timespec as the main data type for
timestamps. This will allow the NTP code to work with timestamps in
nanosecond resolution.
Add offset option to the server/pool/peer directive. It specifies a
correction which will be applied to offsets measured with the NTP
source. It's particularly useful to compensate for a known asymmetry in
network delay or timestamping errors.
Add a new option (-c) to chronyc to enable printing of reports in a
column-separated values (CSV) format. IP addresses will not be resolved
to hostnames, time will be printed as number of seconds since the epoch
and values in seconds will not be converted to other units.
Add a new printf-like function to allow printing of all fields at once
and rework all commands which print a report to use it. Add functions
for printing of headers and information fields, and formatting of IP
addresses and reference IDs.
There was an incompatible change in the client access report. To avoid
bumping the protocol version drop support for the original request/reply
types and define new CLIENT_ACCESSES_BY_INDEX2 types as a newer version
of the command.
The clientlog record still uses 16-bit integers to count dropped
packets, but this will avoid an incompatible change in the command
reply if there will be a need to count more than 2^16 drops.
Require that at least one of the sources specified with this option is
selectable (i.e. recently reachable and not a falseticker) before
updating the clock. Together with the trust option this may be useful to
allow a trusted, but not very precise, reference clock or a trusted
authenticated NTP source to be safely combined with unauthenticated NTP
sources in order to improve the accuracy of the clock. They can be
selected and used for synchronization only if they agree with the
trusted and required source.
Assume time from a source that is specified with the trust option is
always true. It can't be rejected as falseticker in the source
selection if sources that are specified without this option don't agree
with it.
Instead of printing some large arbitrary values use dash in the LastRx
column of the sources output and the Last/Int columns in the clients
output when no sample or hit is recorded.
Add new fields from clientlog to the report and print them in chronyc.
Rework the code to skip empty records in the hash table. The reply no
longer has variable length, all client fields are filled even if some
are empty. Reply with RPY_NULL when the facility is disabled.
- a feature test macro is needed to get msg_control in struct msghdr
- variables must not be named sun to avoid conflict with a macro
- res_init() needs -lresolv
- configure tests for IPv6 and getaddrinfo need -lsocket -lnsl
- pid_t is defined as long and needs to be cast for %d format
Follow the removal of the server authentication support and remove also
the client support. The -a and -f options are now silently ignored to
not break scripts. The authhash and password commands print a warning,
but they don't return an error.
Allow multiple hostnames/addresses separated by comma to be specified
with the -h option. Hostnames are resolved to up to 16 addresses. When
connecting to an address fails or no reply is received, try the next
address in the list.
Set the default value for the -h option to 127.0.0.1,::1.
If the specified hostname starts with /, consider it to be the path of
the chronyd Unix domain command socket. Create the client socket in the
same directory as the server socket (which is not accessible by others)
and change its permission to 0666 to allow chronyd running without root
privileges to send a reply. Remove the socket on exit.
Call connect() on the socket to set the remote address and switch from
sendto()/recvfrom() to send()/recv(). Setting the IP_RECVERR option no
longer seems to be necessary in order to get ECONNREFUSED errors.
Add a signal handler and rework the code to go through close_io() even
when terminated by a signal. This will allow chronyc to remove Unix
domain sockets on exit.
The second form configures the automatic stepping, similarly to the
makestep directive. It has two parameters, stepping threshold (in
seconds) and number of future clock updates for which will be the
threshold active. This can be used with the burst command to quickly
make a new measurement and correct the clock by stepping if needed,
without waiting for chronyd to complete the measurement and update the
clock.
The minsamples and maxsamples directives now set the default value,
which can be overriden for individual sources in the server/peer/pool
and refclock directives.
A new option can be now used in the pool directive: maxsources sets the
maximum number of sources that can be used from the pool, the default
value is 4.
On start, when the pool name is resolved, chronyd will add up to 16
sources, one for each resolved address. When the number of sources from
which at least one valid reply was received reaches maxsources, the
other sources will be removed.
This is to make sure chronyd will see the remote address as 127.0.0.1
and allow access even when localhost resolves to an address of a
non-loopback interface.
To prevent an attacker using chronyd in an amplification attack, change
the protocol to include padding in request packets so that the largest
possible reply is not larger than the request. Request packets that
don't include this padding are ignored as invalid.
This is an incompatible change in the protocol. Clients from chrony
1.27, 1.28 and 1.29 will receive NULL reply with STT_BADPKTVERSION and
print "Protocol version mismatch". Clients from 1.26 and older will not
receive a reply as it would be larger than the request if it was padded
to be compatible with their protocol.
Before calling PKL_ReplyLength() check that the packet has full header.
This didn't change the outcome of the test if the packet was shorter as
the invalid result from PKL_ReplyLength() was either larger than length
of the packet or smaller than header length, failing the length check in
both cases.
Support for the SUBNETS_ACCESSED and CLIENT_ACCESSES commands was
enabled in chronyd, but in chronyc it was always disabled and the
CLIENT_ACCESSES_BY_INDEX command was used instead. As there is no plan
to enable it in the future, remove the support completely.
When the length of the REQ_SUBNETS_ACCESSED, REQ_CLIENT_ACCESSES
command requests and the RPY_SUBNETS_ACCESSED, RPY_CLIENT_ACCESSES,
RPY_CLIENT_ACCESSES_BY_INDEX, RPY_MANUAL_LIST command replies is
calculated, the number of items stored in the packet is not validated.
A crafted command request/reply can be used to crash the server/client.
Only clients allowed by cmdallow (by default only localhost) can crash
the server.
With chrony versions 1.25 and 1.26 this bug has a smaller security
impact as the server requires the clients to be authenticated in order
to process the subnet and client accesses commands. In 1.27 and 1.28,
however, the invalid calculated length is included also in the
authentication check which may cause another crash.
Combine only sources whose distance is shorter than distance of the
selected source multiplied by the value of combinelimit and their
estimated frequencies are close to the frequency of the selected source.
Add outlyer status for sources which are selectable, but not included in
the combining. The status is displayed as '-' in the chronyc sources
output.
- normalize command line before parsing
- compare whole words
- check for missing/extra arguments in config parsing
- use strdup for string allocation
- share code for reporting syntax errors
- avoid using function pointers
- cleanup the code a bit
Allow different hash functions to be used in the NTP and cmdmon
protocols. This breaks the cmdmon protocol compatibility. Extended key
file format is used to specify the hash functions for chronyd and new
authhash command is added to chronyc. MD5 is the default and the only
function included in the chrony source code, other functions will be
available from libraries.
Require that the ratio of the increase in delay from the minimum one in
the stats data register to the standard deviation of the offsets in the
register is less than maxdelaydevratio or the difference between
measured offset and predicted offset is larger than the increase in
delay. In the allowed delay increase is included also skew and maximum
clock frequency error.
maxdelaydevratio is 10.0 by default.
Instead of following skew changes, adjust polling interval so that the
number of measurements used in the regression algorithm remains close to
a target value. It can be configured with a new polltarget option
(6 by default).
