xref: /aosp_15_r20/external/sdv/vsomeip/documentation/vsomeipUserGuide

vsomeip
=======
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Copyright
+++++++
Copyright (C) 2015-2019, Bayerische Motoren Werke Aktiengesellschaft (BMW AG)

License
+++++++
This Source Code Form is subject to the terms of the Mozilla Public
License, v. 2.0. If a copy of the MPL was not distributed with this
file, You can obtain one at http://mozilla.org/MPL/2.0/.

Version
+++++++
// set the version to the one we get from cmake
// or pass it via -a version=$VSOMEIP_VERSION to asciidoc
This documentation was generated for version {version} of vsomeip.

vsomeip Overview
----------------
The vsomeip stack implements the http://some-ip.com/[Scalable service-Oriented
MiddlewarE over IP (SOME/IP)] protocol. The stack consists out of:

* a shared library for SOME/IP (`libvsomeip.so`)
* a second shared library for SOME/IP's service discovery (`libvsomeip-sd.so`)
  which is loaded during runtime if the service discovery is enabled.

Build Instructions
------------------
Dependencies
~~~~~~~~~~~~
* A C++11 enabled compiler like gcc >= 5.2 is needed.
* vsomeip uses cmake as buildsystem.
* vsomeip uses Boost >= 1.55:
** Ubuntu 14.04:
*** `sudo apt-get install libboost-system1.55-dev libboost-thread1.55-dev
    libboost-log1.55-dev`
** Ubuntu 12.04: a PPA is necessary to use version 1.54 of Boost:
*** URL: https://launchpad.net/~boost-latest/+archive/ubuntu/ppa
*** `sudo add-apt-repository ppa:boost-latest/ppa`
*** `sudo apt-get install libboost-system1.55-dev libboost-thread1.55-dev
    libboost-log1.55-dev`
* For the tests Google's test framework
  https://code.google.com/p/googletest/[gtest] in version 1.7.0 is needed
** URL: https://googletest.googlecode.com/files/gtest-1.7.0.zip[direct link,
   version 1.7.0]
* To build the documentation asciidoc, source-highlight, doxygen and graphviz is needed:
** `sudo apt-get install asciidoc source-highlight doxygen graphviz`

Compilation
~~~~~~~~~~~
anchor:Compilation[]
For compilation call:
[source, bash]
----
mkdir build
cd build
cmake ..
make
----

To specify a installation directory (like `--prefix=` if you're used to
autotools) call cmake like:
[source, bash]
----
cmake -DCMAKE_INSTALL_PREFIX:PATH=$YOUR_PATH ..
make
make install
----

Compilation with predefined base path
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To predefine the base path, the path that is used to create the local sockets,
call cmake like:
[source,bash]
----
cmake -DBASE_PATH=<YOUR BASE PATH> ..
----
The default base path is /tmp.

Compilation with predefined unicast and/or diagnosis address
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To predefine the unicast address, call cmake like:
[source,bash]
----
cmake -DUNICAST_ADDRESS=<YOUR IP ADDRESS> ..
----

To predefine the diagnosis address, call cmake like:
[source,bash]
----
cmake -DDIAGNOSIS_ADDRESS=<YOUR DIAGNOSIS ADDRESS> ..
----
The diagnosis address is a single byte value.

Compilation with custom default configuration folder
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To change the default configuration folder, call cmake like:
[source,bash]
----
cmake -DDEFAULT_CONFIGURATION_FOLDER=<DEFAULT CONFIGURATION FOLDER> ..
----
The default configuration folder is /etc/vsomeip.

Compilation with custom default configuration file
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To change the default configuration file, call cmake like:
[source,bash]
----
cmake -DDEFAULT_CONFIGURATION_FILE=<DEFAULT CONFIGURATION FILE> ..
----
The default configuration file is /etc/vsomeip.json.

Compilation with signal handling
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To compile vsomeip with signal handling (SIGINT/SIGTERM) enabled,
call cmake like:
[source,bash]
----
cmake -DENABLE_SIGNAL_HANDLING=1 ..
----
In the default setting, the application has to take care of shutting
down vsomeip in case these signals are received.

Compilation with user defined "READY" message
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To compile vsomeip with a user defined message signal the IP routing
to be ready to send/receive messages, call cmake like:
[source,bash]
----
cmake -DROUTING_READY_MESSAGE=<YOUR MESSAGE> ..
----

Compilation with configuration overlays
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To compile vsomeip with configuration overlays enabled, call cmake
like:
[source,bash]
----
cmake -DENABLE_CONFIGURATION_OVERLAYS=1 ..
----

Compilation with vSomeIP 2 compatibility layer
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To compile vsomeip with enabled vSomeIP 2 compatibility layer, call
cmake like:
[source,bash]
----
cmake -DENABLE_COMPAT=1 ..
----

Compilation of examples
^^^^^^^^^^^^^^^^^^^^^^^
For compilation of the examples call:
[source, bash]
----
mkdir build
cd build
cmake ..
make examples
----

Compilation of tests
^^^^^^^^^^^^^^^^^^^^
To compile the tests, first unzip gtest to location of your desire.
Some of the tests require a second node on the same network. There are two cmake
variables which are used to automatically adapt the json files to the used
network setup:

* `TEST_IP_MASTER`: The IP address of the interface which will act as test
  master.
* `TEST_IP_SLAVE`: The IP address of the interface of the second node which will
  act as test slave.

If one of this variables isn't specified, only the tests using local
communication exclusively will be runnable.

Additionally the unit tests require enabled signal handling which can be enabled
via the `ENABLE_SIGNAL_HANDLING` cmake variable.

Example, compilation of tests:
[source, bash]
----
mkdir build
cd build
export GTEST_ROOT=$PATH_TO_GTEST/gtest-1.7.0/
cmake -DENABLE_SIGNAL_HANDLING=1 -DTEST_IP_MASTER=10.0.3.1 -DTEST_IP_SLAVE=10.0.3.125 ..
make check
----

Additional make targets for the tests:

* Call `make build_tests` to only compile the tests
* Call `ctest` in the build directory to execute the tests without a verbose
  output
* To run single tests call `ctest --verbose --tests-regex $TESTNAME` short
  form: `ctest -V -R $TESTNAME`
* To list all available tests run `ctest -N`.
* For further information about the tests please have a look at the
  `readme.txt` in the `test` subdirectory.

For development purposes two cmake variables exist which control if the
json files and test scripts are copied (default) or symlinked into the build
directory. These settings are ignored on Windows.

* `TEST_SYMLINK_CONFIG_FILES`: Controls if the json and scripts needed
  to run the tests are copied or symlinked into the build directory. (Default:
  OFF, ignored on Windows)
* `TEST_SYMLINK_CONFIG_FILES_RELATIVE`: Controls if the json and scripts needed
  to run the tests are symlinked relatively into the build directory.
  (Default: OFF, ignored on Windows)

Example cmake call:
[source, bash]
----
cmake  -DTEST_SYMLINK_CONFIG_FILES=ON -DTEST_SYMLINK_CONFIG_FILES_RELATIVE=ON ..
----

For compilation of only a subset of tests (for a quick
functionality check) the cmake variable `TESTS_BAT` has
to be set:

Example cmake call:
[source, bash]
----
cmake  -DTESTS_BAT=ON ..
----

Compilation of vsomeip_ctrl
^^^^^^^^^^^^^^^^^^^^^^^^^^^
For compilation of the <<vsomeip_ctrl>> utility call:
[source, bash]
----
mkdir build
cd build
cmake ..
make vsomeip_ctrl
----

Generating the documentation
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
To generate the documentation call cmake as described in <<Compilation>> and
then call `make doc`.
This will generate:

* The README file in html: `$BUILDDIR/documentation/README.html`
* A doxygen documentation in `$BUILDDIR/documentation/html/index.html`

Starting vsomeip Applications / Used environment variables
----------------------------------------------------------
On startup the following environment variables are read out:

* `VSOMEIP_APPLICATION_NAME`: This environment variable is used to specify the
  name of the application. This name is later used to map a client id to the
  application in the configuration file. It is independent from the
  application's binary name.
* `VSOMEIP_CONFIGURATION`: vsomeip uses the default configuration file `/etc/vsomeip.json`
   and/or the default configuration folder `/etc/vsomeip`. This can be overridden by a
   local configuration file `./vsomeip.json` and/or a local configuration folder `./vsomeip`.
   If `VSOMEIP_CONFIGURATION` is set to a valid file or directory path, this is used instead
   of the standard configuration (thus neither default nor local file/folder will be parsed).
* `VSOMEIP_MANDATORY_CONFIGURATION_FILES`: vsomeip allows to specify mandatory configuration
   files to speed-up application startup. While mandatory configuration files are read by all
   applications, all other configuration files are only read by the application that is
   responsible for connections to external devices. If this configuration variable is not set,
   the default mandatory files vsomeip_std.json, vsomeip_app.json and vsomeip_plc.json are used.
* `VSOMEIP_CLIENTSIDELOGGING`: Set this variable to an empty string to enable logging of
   any received messages to DLT in all applications acting as routing manager proxies. For
   example add the following line to the  application's systemd service file:
   `Environment=VSOMEIP_CLIENTSIDELOGGING=""`
   To enable service-specific logs, provide a space- or colon-separated list of ServiceIDs (using
   4-digit hexadecimal notation, optionally followed by dot-separted InstanceID). For example:
   `Environment=VSOMEIP_CLIENTSIDELOGGING="b003.0001 f013.000a 1001 1002"`
   `Environment=VSOMEIP_CLIENTSIDELOGGING="b003.0001:f013.000a:1001:1002"`

NOTE: If the file/folder that is configured by `VSOMEIP_CONFIGURATION` does _not_ exist,
the default configuration locations will be used.

NOTE: vsomeip will parse and use the configuration from all files in a configuration folder
but will _not_ consider directories within the configuration folder.

In the following example the application `my_vsomeip_application` is started.
The settings are read from the file `my_settings.json` in the current working
directory. The client id for the application can be found under the name
`my_vsomeip_client` in the configuration file.

[source, bash]
----
#!/bin/bash
export VSOMEIP_APPLICATION_NAME=my_vsomeip_client
export VSOMEIP_CONFIGURATION=my_settings.json
./my_vsomeip_application
----

Configuration File Structure
----------------------------
The configuration files for vsomeip are http://www.json.org/[JSON]-Files and are
composed out of multiple key value pairs and arrays.

[quote, , json.org]
____
* An object is an unordered set of name/value pairs. An object begins with `{
(left brace)` and ends with `} (right brace)`. Each name is followed by `:
(colon)` and the name/value pairs are separated by `, (comma)`.

* An array is an ordered collection of values. An array begins with `[ (left
bracket)` and ends with `] (right bracket)`. Values are separated by `,
(comma)`.

* A value can be a _string_ in double quotes, or a _number_, or `true` or `false`
or `null`, or an _object_ or an _array_. These structures can be nested.
____

Configuration file element explanation:


* 'unicast'
+
The IP address of the host system.
+
* 'netmask'
+
The netmask to specify the subnet of the host system.
+
* 'device' (optional)
+
If specified, IP endpoints will be bound to this device.
+
* 'diagnosis'
+
The diagnosis address (byte) that will be used to build client identifiers. The
diagnosis address is assigned to the most significant byte in all client
identifiers if not specified otherwise (for example through a predefined client
ID).
+
* 'diagnosis_mask'
+
The diagnosis mask (2 byte) is used to control the maximum amount of allowed
concurrent vsomeip clients on an ECU and the start value of the client IDs.
+
The default value is `0xFF00` meaning
the most significant byte of the client ID is reserved for the diagnosis
address and the client IDs will start with the diagnosis address as specified.
The maximum number of clients is 255 as the Hamming weight of the inverted mask
is 8 (2^8 = 256 - 1 (for the routing manager) = 255). The resulting client ID
range with a diagnosis address of for example 0x45 would be 0x4501 to 0x45ff.
+
Setting the mask to `0xFE00` doubles client ID range to 511 clients as the
Hamming weight of the inverted mask is greater by one.  With a diagnosis address
of 0x45 the start value of client IDs is 0x4401 as bit 8 in 0x4500 is masked
out. This then yields a client ID range of 0x4400 to 0x45ff.

* 'network'
+
Network identifier used to support multiple routing managers on one host. This
setting changes the name of the shared memory segment in `/dev/shm` and the name
of the unix domain sockets in `/tmp/`. Defaults to `vsomeip` meaning the shared
memory will be named `/dev/shm/vsomeip` and the unix domain sockets will be
named `/tmp/vsomeip-$CLIENTID`
+
//Logging
* 'logging'
+
** 'level'
+
Specifies the log level (valid values: _trace_, _debug_, _info_, _warning_,
_error_, _fatal_).
+
** 'console'
+
Specifies whether logging via console is enabled (valid values: _true, false_).
+
** 'file'
+
*** 'enable'
+
Specifies whether a log file should be created (valid values: _true, false_).
+
*** 'path'
+
The absolute path of the log file.
+
** 'dlt'
+
Specifies whether Diagnostic Log and Trace (DLT) is enabled (valid values:
_true, false_).
+
** 'version'
+
Configures logging of the vsomeip version
+
*** 'enable'
+
Enable or disable cyclic logging of vsomeip version, defaults to true (valid
values: _true, false_)
+
*** 'interval'
+
Configures interval in seconds to log the vsomeip version. Default value is 10.
+
** 'memory_log_interval'
+
Configures interval in seconds in which the routing manager logs its used
memory. Setting a value greater than zero enables the logging.
+
** 'status_log_interval'
+
Configures interval in seconds in which the routing manager logs its internal
status. Setting a value greater than zero enables the logging.
+
//Tracing
* anchor:config-tracing[]'tracing' (optional)
+
** 'enable'
+
Specifies whether the tracing of the SOME/IP messages is enabled
(valid values: _true, false_). Default value is _false_.
If tracing is enabled, the messages will be forwarded to DLT by
the <<traceconnector, Trace Connector>>
+
** 'sd_enable'
+
Specifies whether the tracing of the SOME/IP service discovery messages is
enabled (valid values: _true, false_). Default value is _false_.
+
** 'channels (array)' (optional)
+
Contains the channels to DLT.
+
NOTE: You can set up multiple channels to DLT over that you can forward the
messages.
+
*** 'name'
+
The name of the channel.
+
*** 'id'
+
The id of the channel.
+
** 'filters (array)' (optional)
+
Contains the filters that are applied on the messages.
+
NOTE: You can apply filters respectively filter rules on the messages with
specific criterias and expressions. So only the filtered messages are forwarded
to DLT.
+
*** 'channel' (optional)
+
The id of the channel over that the filtered messages are forwarded to DLT. If
no channel is specified the default channel (TC) is used. If you want to use a
filter in several different channels, you can provide an array of channel ids.
+
NOTE: If you use a positive filter with multiple channels, the same message
will be forwared multiple times to DLT.
+
*** 'matches' (optional)
+
Specification of the criteria to include/exclude a message into/from the trace.
You can either specify lists (array) or ranges of matching elements.
+
A list may contain single identifiers which match all messages from/to all
instances of the corresponding service or tuples consisting of service-,
instance- and method-identifier. 'any' may be used as a wildcard for matching
all services, instances or methods.
+
A range is specified by two tuples "from" and "to", each consisting of
service-, instance-and method-identifier. All messages with service-,
instance-and method-identifiers that are greater than or equal to "from"
and less than or equal to "to" are matched.
+
*** 'type' (optional)
+
Specifies the filter type (valid values: "positive", "negative"). When a positive
filter is used and a message matches one of the filter rules, the message will be
traced/forwarded to DLT. With a negative filter messages can be excluded. So when a
message matches one of the filter rules, the message will not be traced/forwarded to
DLT. Default value is "positive".
+
//Applications
* 'applications (array)'
+
Contains the applications of the host system that use this config file.
+
** 'name'
+
The name of the application.
+
** 'id'
+
The id of the application. Usually its high byte is equal to the diagnosis address. In this
case the low byte must be different from zero. Thus, if the diagnosis address is 0x63, valid
values range from 0x6301 until 0x63FF. It is also possible to use id values with a high byte
different from the diagnosis address.
+
** 'max_dispatchers' (optional)
+
The maximum number of threads that shall be used to execute the application callbacks. Default is 10.
+
** 'max_dispatch_time' (optional)
+
The maximum time in ms that an application callback may consume before the callback is
considered to be blocked (and an additional thread is used to execute pending
callbacks if max_dispatchers is configured greater than 0). The default value if not specified is 100ms.
+
** 'threads' (optional)
+
The number of internal threads to process messages and events within an application.
Valid values are 1-255. Default is 2.
+
** 'io_thread_nice' (optional)
+
The nice level for internal threads processing messages and events. POSIX/Linux only.
For actual values refer to nice() documentation.
+
** 'request_debounce_time' (optional)
+
Specifies a debounce-time interval in ms in which request-service messages are sent to
the routing manager. If an application requests many services in short same time
the load of sent messages to the routing manager and furthermore the replies from the
routing manager (which contains the routing info for the requested service if available)
can be heavily reduced. The default value if not specified is 10ms.
+
** 'plugins' (optional array)
+
Contains the plug-ins that should be loaded to extend the functionality of vsomeip.
+
*** 'name'
+
The name of the plug-in.
+
*** 'type'
+
The plug-in type (valid values: _application_plugin_).
+
An application plug-in extends the functionality on application level. It gets informed
by vsomeip over the basic application states (INIT/START/STOP) and can, based on these
notifications, access the standard "application"-API via the runtime.
+
** 'overlay' (optional)
+
Contains the path to a configuration that overwrites specific configuration elements
(unicast, netmask, device, network, diagnosis address & mask, service discovery) for the
application. This allows to manage different network addresses from a single process.
+
NOTE: This feature is only available if vsomeip was compiled with ENABLE_CONFIGURATION_OVERLAYS.
+
* `services` (array)
+
Contains the services of the service provider.

** `service`
+
The id of the service.

** `instance`
+
The id of the service instance.

** `protocol` (optional)
+
The protocol that is used to implement the service instance. The default setting
is _someip_. If a different setting is provided, vsomeip does not open the specified
port (server side) or does not connect to the specified port (client side). Thus,
this option can be used to let the service discovery announce a service that is
externally implemented.

** `unicast` (optional)
+
The unicast that hosts the service instance.
+
NOTE: The unicast address is needed if external service instances shall be used,
but service discovery is disabled. In this case, the provided unicast address
is used to access the service instance.

** `reliable`
+
Specifies that the communication with the service is reliable respectively the
TCP protocol is used for communication.

*** `port`
+
The port of the TCP endpoint.

*** `enable-magic-cookies`
+
Specifies whether magic cookies are enabled (valid values: _true_, _false_).

** `unreliable`
+
Specifies that the communication with the service is unreliable respectively the
UDP protocol is used for communication (valid values: the _port_ of the UDP
endpoint).

** `events` (array)
+
Contains the events of the service.

*** `event`
+
The id of the event.

*** `is_field`
+
Specifies whether the event is of type field.
+
NOTE: A field is a combination of getter, setter and notification event. It
contains at least a getter, a setter, or a notifier. The notifier sends an event
message that transports the current value of a field on change.

*** `is_reliable`
+
Specifies whether the communication is reliable respectively whether the event
is sent with the TCP protocol (valid values: _true_,_false_).
+
If the value is _false_ the UDP protocol will be used.

** `eventgroups` (array)
+
Events can be grouped together into on event group. For a client it is thus
possible to subscribe for an event group and to receive the appropriate events
within the group.

*** `eventgroup`
+
The id of the event group.

*** `events` (array)
+
Contains the ids of the appropriate events.

*** `multicast`
+
Specifies the multicast that is used to publish the eventgroup.

**** `address`
+
The multicast address.

**** `port`
+
The multicast port.

*** `threshold`
+
Specifies when to use multicast and when to use unicast to send a notification event.
Must be set to a non-negative number. If it is set to zero, all events of the eventgroup
will be sent by unicast. Otherwise, the events will be sent by unicast as long as the
number of subscribers is lower than the threshold and by multicast if the number
of subscribers is greater or equal. This means, a threshold of 1 will lead to all events
being sent by multicast. The default value is _0_.

** `debounce-times` (object)
+
Used to configure the nPDU feature. This is described in detail in
<<npdu,vSomeIP nPDU feature>>.

** `someip-tp` (object)
+
Used to configure the SOME/IP-TP feature. There's an example available at
<<someiptp, SOME/IP-TP>>.

*** `service-to-client` (array)
+
Contains the IDs for responses, fields and events which are sent from the node
to a remote client which can be segmented via SOME/IP-TP if they exceed the
maximum message size for UDP communication. If an ID isn't listed here the
message will otherwise be dropped if the maximum message size is exceeded.

*** `client-to-service` (array)
+
Contains the IDs for requests, which are sent from the node
to a remote service which can be segmented via SOME/IP-TP if they exceed the
maximum message size for UDP communication. If an ID isn't listed here the
message will otherwise be dropped if the maximum message size is exceeded.
Please note that the unicast key has to be set to the remote IP address of the
offering node for this setting to take effect.


* `clients` (array)
+
The client-side ports that shall be used to connect to a specific service.
For each service, an array of ports to be used for reliable / unreliable
communication can be specified. vsomeip will take the first free port of
the list. If no free port can be found, the connection will fail. If
vsomeip is asked to connect to a service instance without specified port(s),
the port will be selected by the system. This implies that the user has
to ensure that the ports configured here do not overlap with the ports
automatically selected by the IP stack.

** `service`
** `instance`
+
Together they specify the service instance the port configuration shall be applied to.

** `reliable` (array)
+
The list of client ports to be used for reliable (TCP) communication to the given
service instance.

** `unreliable` (array)
+
The list of client ports to be used for unreliable (UDP) communication to the given
service instance.

+
Additionally there is the possibility to configure mappings between ranges of client
ports and ranges of remote service ports.
(If a client port is configured for a specific service / instance, the port range mapping is ignored)

** `reliable_remote_ports`
+
Specifies a range of reliable remote service ports

** `unreliable_remote_ports`
+
Specifies a range of unreliable remote service ports

** `reliable_client_ports`
+
Specifies the range of reliable client ports to be mapped to the reliable_remote_ports range

** `unreliable_client_ports`
+
Specifies the range of unreliable client ports to be mapped to the unreliable_remote_ports range


** `first`
+
Specifies the lower bound of a port range

** `last`
+
Specifies the upper bound of a port range

* `payload-sizes` (array)
+
Array to limit the maximum allowed payload sizes per IP and port. If not
specified otherwise the allowed payload sizes are unlimited. The settings in
this array only affect communication over TCP. To limit the local payload size
`max-payload-size-local` can be used.

** `unicast`
+
On client side: the IP of the remote service for which the payload size should
be limited.
+
On service side: the IP of the offered service for which the payload size for
receiving and sending should be limited.

** `ports` (array)
+
Array which holds pairs of port and payload size statements.

*** `port`
+
On client side: the port of the remote service for which the payload size should
be limited.
+
On service side: the port of the offered service for which the payload size for
receiving and sending should be limited.

*** `max-payload-size`
+
On client side: the payload size limit in bytes of a message sent to the
remote service hosted on beforehand specified IP and port.
+
On service side: the payload size limit in bytes of messages received and sent
by the service offered on previously specified IP and port.
+
If multiple services are hosted on the same port they all share the limit
specified.

* `max-payload-size-local`
+
The maximum allowed payload size for node internal communication in bytes. By
default the payload size for node internal communication is unlimited. It can be
limited via this setting.

* `max-payload-size-reliable`
+
The maximum allowed payload size for TCP communication in
bytes. By default the payload size for TCP communication is
unlimited. It can be limited via this setting.

* `max-payload-size-unreliable`
+
The maximum allowed payload size for UDP communication via SOME/IP-TP in
bytes. By default the payload size for UDP via SOME/IP-TP communication is
unlimited. It can be limited via this setting. This setting only applies for
SOME/IP-TP enabled methods/events/fields (otherwise the UDP default of 1400
bytes applies). See <<someiptp, SOME/IP-TP>> for an example configuration.

* `endpoint-queue-limits` (array)
+
Array to limit the maximum allowed size in bytes of cached outgoing messages per
IP and port (message queue size per endpoint). If not specified otherwise the
allowed queue size is unlimited. The settings in this array only affect external
communication. To limit the local queue size `endpoint-queue-limit-local` can
be used.

** `unicast`
+
On client side: the IP of the remote service for which the queue size of sent
requests should be limited.
+
On service side: the IP of the offered service for which the queue size for
sent responses should be limited. This IP address is therefore
identical to the IP address specified via `unicast` setting on top level of the
json file.

** `ports` (array)
+
Array which holds pairs of port and queue size statements.

*** `port`
+
On client side: the port of the remote service for which the queue size of sent
requests should be limited.
+
On service side: the port of the offered service for which the queue size for
send responses should be limited.

*** `queue-size-limit`
+
On client side: the queue size limit in bytes of messages sent to the
remote service hosted on beforehand specified IP and port.
+
On service side: the queue size limit in bytes for responses sent by the service
offered on previously specified IP and port.
+
If multiple services are hosted on the same port they all share the limit
specified.

* `endpoint-queue-limit-external`
+
Setting to limit the maximum allowed size in bytes of cached outgoing messages
for external communication (message queue size per endpoint). By default the
queue size for external communication is unlimited. It can be limited via this
setting. Settings done in the `endpoint-queue-limits` array override this
setting.

* `endpoint-queue-limit-local`
+
Setting to limit the maximum allowed size in bytes of cached outgoing messages
for local communication (message queue size per endpoint). By default the queue
size for node internal communication is unlimited. It can be limited via this
setting.

* `buffer-shrink-threshold`
+
The number of processed messages which are half the size or smaller than the
allocated buffer used to process them before the memory for the buffer is
released and starts to grow dynamically again. This setting can be useful in
scenarios where only a small number of the overall messages are a lot bigger
then the rest and the memory allocated to process them should be released in a
timely manner. If the value is set to zero the buffer sizes aren't reseted and
are as big as the biggest processed message. (default is 5)
+
Example: `buffer-shrink-threshold` is set to 50. A message with 500 bytes has to
be processed and the buffers grow accordingly. After this message 50 consecutive
messages smaller than 250 bytes have to be processed before the buffer size is
reduced and starts to grow dynamically again.

* `tcp-restart-aborts-max`
+
Setting to limit the number of TCP client endpoint restart aborts due to unfinished TCP handshake.
After the limit is reached, a forced restart of the TCP client endpoint is done if the connection attempt is still pending.

* `tcp-connect-time-max`
+
Setting to define the maximum time until the TCP client endpoint connection attempt should be finished.
If `tcp-connect-time-max` is elapsed, the TCP client endpoint is forcely restarted if the connection attempt is still pending.

* `udp-receive-buffer-size`
+
Specifies the size of the socket receive buffer (`SO_RCVBUF`) used for
UDP client and server endpoints in bytes. (default: 1703936)

* `internal_services` (optional array)
+
Specifies service/instance ranges for pure internal service-instances.
This information is used by vsomeip to avoid sending Find-Service messages
via the Service-Discovery when a client is requesting a not available service-
instance. Its can either be done on service/instance level or on service level
only which then includes all instance from 0x0000-0xffff.

** `first`
+
The lowest entry of the internal service range.

*** `service`
+
The lowest Service-ID in hex of the internal service range.

*** `instance` (optional)
+
The lowest Instance-ID in hex of a internal service-instance range.
If not specified the lowest Instance-ID is 0x0000.

** `last`
+
The highest entry of the internal service range.

*** `service`
+
The highest Service-ID in hex of a internal service range.

*** `instance` (optional)
+
The highest Instance-ID in hex of a internal service-instance range.
If not specified the highest Instance-ID is 0xFFFF.

* `debounce` (optional array)
+
Events/fields sent by external devices will be forwarded to the
applications only if a configurable function evaluates to true. The
function checks whether the event/field payload has changed and whether
a specified interval has been elapsed since the last forwarding.

** `service`
+
Service ID which hosts the events to be debounced.

** `instance`
+
Instance ID which hosts the events to be debounced.

** `events`
+
Array of events which shall be debounced based on the following
configuration options.

*** `event`
+
Event ID.

*** `on_change`
+
Specifies whether the event is only forwared on
paylaod change or not. (valid values: _true_, _false_).

*** `ignore`
+
Array of payload indexes with given bit mask (optional)
to be ignored in payload change evaluation.
Instead of specifying an index / bitmask pair, one can only define the paylaod index
which shall be ignored in the evaluation.

**** `index`
+
Payload index to be checked with given bitmask.

**** `mask`
+
1Byte bitmask applied to byte at given payload index.
Example mask: 0x0f ignores payload changes in low nibble of the byte at given index.

*** `interval`
+
Specifies if the event shall be debounced based on elapsed time interval.
(valid values: _time in ms_, _never_).

*** `on_change_resets_interval_` (optional)
Specifies if interval timer is reset when payload change was detected.
(valid values: _false_, _true_).

* `routing`
+
The name of the application that is responsible for the routing.

* `routing-credentials`
+
The UID / GID of the application acting as routing manager.
(Must be specified if credentials checks are enabled using _check_credentials_ set to _true_ in order to successfully check the routing managers credentials passed on connect)

** `uid`
+
The routing managers UID.

** `gid`
+
The routing managers GID.

* `shutdown_timeout`
+
Configures the time in milliseconds local clients wait for acknowledgement of
their deregistration from the routing manager during shutdown. Defaults to
5000ms.

* `warn_fill_level`
+
The routing manager regulary checks the fill level of the send buffers to its
clients. This variable defines the minimum fill level in percent that leads to
a warning being logged. Defaults to 67.

* `service-discovery`
+
Contains settings related to the Service Discovery of the host application.

** `enable`
+
Specifies whether the Service Discovery is enabled (valid values: _true_,
_false_). The default value is _true_.

** `multicast`
+
The multicast address which the messages of the Service Discovery will be sent
to. The default value is _224.0.0.1_.

** `port`
+
The port of the Service Discovery. The default setting is _30490_.

** `protocol`
+
The protocol that is used for sending the Service Discovery messages (valid
values: _tcp_, _udp_). The default setting is _udp_.

** `initial_delay_min`
+
Minimum delay before first offer message.

** `initial_delay_max`
+
Maximum delay before first offer message.

** `repetitions_base_delay`
+
Base delay sending offer messages within the repetition phase.

** `repetitions_max`
+
Maximum number of repetitions for provided services within the
repetition phase.

** `ttl`
+
Lifetime of entries for provided services as well as consumed services and eventgroups.

** `ttl_factor_offers` (optional array)
+
Array which holds correction factors for incoming remote offers. If a value
greater than one is specified for a service instance, the TTL field of the
corresponding service entry will be multiplied with the specified factor. +
Example: An offer of a service is received with a TTL of 3 sec and the TTL
factor is set to 5. The remote node stops offering the service w/o sending a
StopOffer message. The service will then expire (marked as unavailable) 15 seconds
after the last offer has been received.

*** `service`
+
The id of the service.

*** `instance`
+
The id of the service instance.

*** `ttl_factor`
+
TTL correction factor

** `ttl_factor_subscriptions` (optional array)
+
Array which holds correction factors for incoming remote subscriptions. If a
value greater than one is specified for a service instance, the TTL field of the
corresponding eventgroup entry will be multiplied with the specified factor. +
Example: A remote subscription to an offered service is received with a TTL of 3
sec and the TTL factor is set to 5. The remote node stops resubscribing to the
service w/o sending a StopSubscribeEventgroup message. The subscription will
then expire 15 seconds after the last resubscription has been received.

*** `service`
+
The id of the service.

*** `instance`
+
The id of the service instance.

*** `ttl_factor`
+
TTL correction factor

** `cyclic_offer_delay`
+
Cycle of the OfferService messages in the main phase.


** `request_response_delay`
+
Minimum delay of a unicast message to a multicast message for
provided services and eventgroups.
+

** `offer_debounce_time`
+
Time which the stack collects new service offers before they enter the
repetition phase. This can be used to reduce the number of
sent messages during startup. The default setting is _500ms_.
+

** `max_remote_subscribers`
+
Limit the number of possible remote subscribers from same remote IP address
to an eventgroup provided by a service/instance if the remote subscriber uses
different ports for its subscriptions. The default setting is _3_.
+

//Watchdog
* anchor:config-watchdog[]`watchdog` (optional)
+
The Watchdog sends periodically pings to all known local clients.
If a client isn't responding within a configurred time/amount of pongs
the watchdog deregisters this application/client.
If not configured the watchdog isn't activated.
+
** `enable`
+
Specifies whether the watchdog is enabled or disabled.
(valid values: _true, false_), (default is _false_).
+
** `timeout`
+
Specifies the timeout in ms the watchdog gets activated if a ping
isn't answered with a pong by a local client within that time.
(valid values: _2 - 2^32_), (default is _5000_ ms).
+
** `allowed_missing_pongs`
+
Specifies the amount of allowed missing pongs.
(valid values: _1 - 2^32_), (default is _3_ pongs).
+
//CAPI-Selective Broadcasts support
* anchor:config-supports_selective_broadcasts[]`supports_selective_broadcasts` (optional array)
+
This nodes allow to add a list of IP addresses on which CAPI-Selective-Broadcasts feature is supported.
If not specified the feature can't be used and the subscription behavior of the stack is same as with
normal events.
+
** `address`
+
Specifies an IP-Address (in IPv4 or IPv6 notation) on which the "selective"-feature is supported.
Multiple addresses can be configured.

Security
--------
vsomeip has a security implementation based on UNIX credentials.
If activated every local connection is authenticated during connect using the standard UNIX credential passing mechanism.
During authentication a client transfers its client identifier together with its credentials (UID / GID) to the server which is then matched against the configuration.
If received credentials don't match the policy the socket will be immediately closed by the server and an message is logged.
If accepted the client identifier is bound to the receiving socket and can therefore be used to do further security checks on incoming messages (vsomeip messages as well as internal commands).

In general clients can be configured to be allowed/denied to request (means communicate with) and offer different service instances.
Every incoming vsomeip message (request/response/notification) as well as offer service requests or local subscriptions are then checked against the policy.
If an incoming vsomeip message or another operation (e.g. offer/subscribe) violates the configured policies it is skipped and a message is logged.

Furthermore if an application receives informations about other clients/services in the system, it must be received from the authenticated routing manager.
This is to avoid malicious applications faking the routing manager and therefore being able to wrongly inform other clients about services running on the system.
Therefore, whenever the "security" tag is specified, the routing manager (e.g. routingmanagerd/vsomeipd) must be a configured application with a fixed client identifier.
See chapter "Configuration File Structure" on how to configure an application to use a specific client identifier.

Credential passing is only possible via Unix-Domain-Sockets and therefore only available for local communication.
However if security is activated method calls from remote clients to local services are checked as well which means remote clients needs to be explicitly allowed.
Such a policy looks same in case for local clients except the _credentials_ tag can be skipped.

Security configuration
~~~~~~~~~~~~~~~~~~~~~~
The available configuration switches for the security feature are:

// Security
* anchor:config-policy[]`security` (optional)
+
If specified the credential passing mechanism is activated. However no credential or security checks are done as long as _check_credentials_ isn't set to _true_, but the routing manager client ID must be configured if security tag is specified and shall not be set to 0x6300.
If _check_credentials_ is set to _true_, the routing managers UID and GID needs to be specified using _routing-credentials_ tag.

** `check_credentials` (optional)
+
Specifies whether security checks are active or not. This includes credentials checks on connect as well as all policies checks configured in follow.
(valid values: _true, false_), (default is _false_).

** `allow_remote_clients` (optional)
+
Specifies whether incoming remote requests / subscriptions are allowed to be sent to a local proxy / client.
If not specified, all remote requests / subscriptions are allowed to be received by default.
(valid values are 'true' and 'false')

** `policies` (array)
+
Specifies the security policies. Each policy at least needs to specify _allow_ or _deny_.

*** `credentials`
+
Specifies the credentials for which a security policy will be applied.
If _check_credentials_ is set to _true_ the credentials of a local application needs to be specified correctly to ensure local socket authentication can succeed.

**** `uid`
+
Specifies the LINUX user id of the client application as decimal number.
As a wildcard "any" can be used.

**** `gid`
+
Specifies the LINUX group id of the client application as decimal number.
As a wildcard "any" can be used.

**** `allow` / `deny` (optional)
+
Specifies whether the LINUX user and group ids are allowed or denied for the policy.

. `uid` (array)
+
Specifies a list of LINUX user ids. These may either be specified as decimal numbers or as ranges. Ranges
are specified by the first and the last valid id (see example below).

. `gid` (array)
+
Specifies a list of LINUX group ids. These may either be specified as decimal numbers or as ranges. Ranges
are specified by the first and the last valid id (see example below).

*** `allow` / `deny`
+
This tag specifies either _allow_ or _deny_ depending on white- or blacklisting is needed. Specifing _allow_ and _deny_ entries in one policy is therefore not allowed.
With _allow_ a whitelisting of what is allowed can be done which means an empty _allow_ tag implies everything is denied.
With _deny_ a blacklisting of what is allowed can be done which means an empty _deny_ tag implies everything is allowed.

**** `requests` (array)
+
Specifies a set of service instance pairs which the above client application using the credentials above is allowed/denied to communicate with.

. `service`
+
Specifies a service for the _requests_.

. `instance` (deprecated)
+
Specifies a instance for the _requests_
As a wildcard "any" can be used which means a range from instance ID 0x01 to 0xFFFF
which also implies a method ID range from 0x01 to 0xFFFF.

. `instances` (array)
+
Specifies a set of instance ID and method ID range pairs which are allowed/denied to communicate with.
If the `ids` tag below is not used to specify allowed/denied requests on method ID level one can also
only specify a a set of instance ID ranges which are allowed/denied to be requested analogous to the
allowed/denied `offers` section.
If no method IDs are specified, the allowed/denied methods are by default a range from 0x01 to 0xFFFF.

.. `ids`
+
Specifies a set of instance ID ranges which are allowed/denied to communicate with.
It is also possible to specify a single instance ID as array element without giving an upper / lower range bound.
As a wildcard "any" can be used which means a range from instance ID 0x01 to 0xFFFF.
+
`first` - The lower bound of the instance range.
+
`last`  - The upper bound of the instance range.

.. `methods`
+
Specifies a set of method ID ranges which are allowed/denied to communicate with.
It is also possible to specify a single method ID as array element without giving an upper / lower range bound.
As a wildcard "any" can be used which means a range from method ID 0x01 to 0xFFFF.
+
`first` - The lower bound of the method range.
+
`last`  - The upper bound of the method range.

**** `offers` (array)
+
Specifies a set of service instance pairs which are allowed/denied to be offered by the client application using the credentials above.

. `service`
+
Specifies a service for the _offers_.

. `instance` (deprecated)
+
Specifies a instance for the _offers_
As a wildcard "any" can be used which means a range from instance ID 0x01 to 0xFFFF.

. `instances` (array)
+
Specifies a set of instance ID ranges which are allowed/denied to be offered by the client application using the credentials above.
It is also possible to specify a single instance ID as array element without giving an upper / lower range bound.
As a wildcard "any" can be used which means a range from instance ID 0x01 to 0xFFFF.

.. `first`
+
The lower bound of the instance range.

.. `last`
+
The upper bound of the instance range.

<<<

Security configuration example
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[source, bash]
----
...
"security" :
{
    ...
    "policies" :
    [
        {
            ...
            "credentials" :
            {
                "uid" : "44",
                "gid" : "any"
             },
             "allow" :
             [
                 "requests" :
                 [
                     {
                         "service" : "0x6731",
                         "instance" : "0x0001"
                     }
                 ]
             ]
         },
         {
            "credentials" :
            {
                "deny" :
                [
                    {
                        "uid" : [ "1000", { "first" : "1002", "last" : "max" }],
                        "gid" : [ "0", { "first" : "100", "last" : "243" }, "300"]
                    },
                    {
                        "uid" : ["55"],
                        "gid" : ["55"]
                    }
                 ]
             },
             "allow" :
             [
                 "offers" :
                 [
                     {
                        "service" : "0x6728",
                        "instances" : [ "0x0001", { "first" : "0x0003", "last" : "0x0007" }, "0x0009"]
                     },
                     {
                        "service" : "0x6729",
                        "instances" : ["0x88"]
                     },
                     {
                        "service" : "0x6730",
                        "instance" : "any"
                     }
                 ],
                 "requests" :
                 [
                     {
                         "service" : "0x6732",
                         "instances" :
                         [
                             {
                                 "ids" : [ "0x0001", { "first" : "0x0003", "last" : "0x0007" }],
                                 "methods" : [ "0x0001", "0x0003", { "first" : "0x8001", "last" : "0x8006" } ]
                             },
                             {
                                 "ids" : [ "0x0009" ],
                                 "methods" : "any"
                             }
                         ]
                     },
                     {
                        "service" : "0x6733",
                        "instance" : "0x1"
                     },
                     {
                        "service" : "0x6733",
                        "instances" : [ "0x0002", { "first" : "0x0003", "last" : "0x0007" }, "0x0009"]
                     }
                 ]
             ]
         }
     ]
}
----

The config/ folder contains some addition vsomeip configuration files to run the vsomeip
examples with activated security checks.
Additionally there's a security test in the `test/` subfolder which can be used
for further reference. +
They give a basic overview how to use the security related configuration tags described
in this chapter to run a simple request/response or subscribe/notify example locally or
remotely.

Audit Mode
~~~~~~~~~~
vsomeip's security implementation can be put in a so called 'Audit Mode' where
all security violations will be logged but allowed. This mode can be used to
build a security configuration.

To activate the 'Audit Mode' the 'security' object has to be included in the
json file but the 'check_credentials' switch has to be set to false. For
example:

[source, bash]
----
    [...]
    "services" :
    [
        [...]
    ],
    "security" :
    {
        "check_credentials" : "false"
    },
    "routing" : "service-sample",
    [...]
----

Autoconfiguration
-----------------
vsomeip supports the automatic configuration of client identifiers and the routing.
The first application that starts using vsomeip will automatically become the
routing manager if it is _not_ explicitly configured. The client identifiers
are generated from the diagnosis address that can be specified by defining
DIAGNOSIS_ADDRESS when compiling vsomeip. vsomeip will use the diagnosis address
as the high byte and enumerate the connecting applications within the low byte
of the client identifier.

Autoconfiguration of client identifiers isn't meant to be used together with vsomeip Security.
Every client running locally needs to have at least its own credentials configured when security is activated to ensure the credential checks can pass.
Practically that means if a client requests its identifier over the autoconfiguration for which no credentials are configured (at least it isn't known which client identifier is used beforehand) it is impossible for that client to establish a connection to a server endpoint.
However if the credentials for all clients are same it's possible to configure them for the overall (or DIAGNOSIS_ADDRESS) client identifier range to mix autoconfiguration together with activated security.

routingmanagerd
---------------
The routingmanagerd is a minimal vsomeip application intended to offer routing
manager functionality on a node where one system wide configuration file is
present. It can be found in the examples folder.

Example: Starting the daemon on a system where the system wide configuration is
stored under `/etc/vsomeip.json`:
[source, bash]
----
VSOMEIP_CONFIGURATION=/etc/vsomeip.json ./routingmanagerd
----

When using the daemon it should be ensured that:

* In the system wide configuration file the routingmanagerd is defined as
  routing manager, meaning it contains the line `"routing" : "routingmanagerd"`.
  If the default name is overridden the entry has to be adapted accordingly.
  The system wide configuration file should contain the information about all
  other offered services on the system as well.
* There's no other vsomeip configuration file used on the system which contains
  a `"routing"` entry. As there can only be one routing manager per system.


vsomeip Hello World
-------------------
In this paragraph a Hello World program consisting out of a client and a service
is developed. The client sends a message containing a string to the service.
The service appends the received string to the string `Hello` and sends it back
to the client.
Upon receiving a response from the service the client prints the payload of the
response ("Hello World").
This example is intended to be run on the same host.

All files listed here are contained in the `examples\hello_world` subdirectory.

Build instructions
~~~~~~~~~~~~~~~~~~
The example can build with its own CMakeFile, please compile the vsomeip stack
before hand as described in <<Compilation>>. Then compile the example starting
from the repository root directory as followed:
[source, bash]
----
cd examples/hello_world
mkdir build
cd build
cmake ..
make
----

Starting and expected output
~~~~~~~~~~~~~~~~~~~~~~~~~~~

Starting and expected output of service
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[source, bash]
----
$ VSOMEIP_CONFIGURATION=../helloworld-local.json \
  VSOMEIP_APPLICATION_NAME=hello_world_service \
  ./hello_world_service
2015-04-01 11:31:13.248437 [info] Using configuration file: ../helloworld-local.json
2015-04-01 11:31:13.248766 [debug] Routing endpoint at /tmp/vsomeip-0
2015-04-01 11:31:13.248913 [info] Service Discovery disabled. Using static routing information.
2015-04-01 11:31:13.248979 [debug] Application(hello_world_service, 4444) is initialized.
2015-04-01 11:31:22.705010 [debug] Application/Client 5555 got registered!
----

Starting and expected output of client
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[source, bash]
----
$ VSOMEIP_CONFIGURATION=../helloworld-local.json \
  VSOMEIP_APPLICATION_NAME=hello_world_client \
  ./hello_world_client
2015-04-01 11:31:22.704166 [info] Using configuration file: ../helloworld-local.json
2015-04-01 11:31:22.704417 [debug] Connecting to [0] at /tmp/vsomeip-0
2015-04-01 11:31:22.704630 [debug] Listening at /tmp/vsomeip-5555
2015-04-01 11:31:22.704680 [debug] Application(hello_world_client, 5555) is initialized.
Sending: World
Received: Hello World
----

CMakeFile
~~~~~~~~~

[source, bash]
----
include::../examples/hello_world/CMakeLists.txt[]
----

Configuration File For Client and Service
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[source, bash]
----
include::../examples/hello_world/helloworld-local.json[]
----

Service
~~~~~~~

[source, bash]
----
include::../examples/hello_world/hello_world_service.cpp[]
----

The service example results in the following program execution:

:numbered!:

[float]

Main
^^^^^

. __main()__
+
First the application is initialized. After the initialization is
finished the application is started.

[float]
Initialization
^^^^^^^^^^^^^^

[start=2]
. __init()__
+
The initialization contains the registration of a message
handler and an event handler.
+
The message handler declares a callback (__on_message_cbk__) for messages that
are sent to the specific service (specifying the service id, the service
instance id and the service method id).
+
The event handler declares a callback (__on_event_cbk__) for events that occur.
One event can be the successful registration of the application at the runtime.

[float]
Start
^^^^^

[start=3]
. __start()__
+
The application will be started. This function only returns when the application
will be stopped.

[float]
Callbacks
^^^^^^^^^

[start=4]
. __on_state_cbk()__
+
This function is called by the application when an state change occurred. If
the application was successfully registered at the runtime then the specific
service is offered.

. __on_message_cbk()__
+
This function is called when a message/request from a client for the specified
service was received.
+
First a response based upon the request is created.
Afterwards the string 'Hello' will be concatenated with the payload of the
client's request.
After that the payload of the response is created. The payload data is set with
the previously concatenated string.
Finally the response is sent back to the client and the application is stopped.

[float]
Stop
^^^^

[start=6]
. __stop()__
+
This function stops offering the service, unregister the message and the event
handler and shuts down the application.

:numbered:

Client
~~~~~~
[source, bash]
----
include::../examples/hello_world/hello_world_client.cpp[]
----

The client example results in the following program execution:

:numbered!:

[float]
Main
^^^^^

. __main()__
+
First the application is initialized. After the initialization is finished the
application is started.

[float]
Initialization
^^^^^^^^^^^^^^

[start=2]
. __init()__
+
The initialization contains the registration of a message handler, an event
handler and an availability handler.
+
The event handler declares again a callback (__on_state_cbk__) for state changes
that occur.
+
The message handler declares a callback (__on_message_cbk__) for messages that
are received from any service, any service instance and any method.
+
The availability handler declares a callback (__on_availability_cbk__) which is
called when the specific service is available (specifying the service id and the
service instance id).

[float]
Start
^^^^^

[start=3]
. __start()__
+
The application will be started. This function only returns when the application
will be stopped.

[float]
Callbacks
^^^^^^^^^

[start=4]
. __on_state_cbk()__
+

This function is called by the application when an state change occurred. If the
application was successfully registered at the runtime then the specific service
is requested.

. __on_availability_cbk()__
+
This function is called when the requested service is available or no longer
available.
+
First there is a check if the change of the availability is related to the
'hello world service' and the availability changed to true.
If the check is successful a service request is created and the appropriate
service information are set (service id, service instance id, service method
id).
After that the payload of the request is created. The data of the payload is
'World' and will be set afterwards.
Finally the request is sent to the service.

. __on_message_cbk()__
+
This function is called when a message/response was received.
If the response is from the requested service, of type 'RESPONSE' and the return
code is 'OK' then the payload of the response is printed. Finally the
application is stopped.

[float]
Stop
^^^^

[start=7]
. __stop()__
+
This function unregister the event and the message handler and shuts down the
application.

:numbered:

Trace Connector
---------------
anchor:traceconnector[]

Overview/Prerequisites
~~~~~~~~~~~~~~~~~~~~~~

The Trace Connector is used to forward the internal messages that are sent over
the Unix Domain Sockets to DLT. +
Thus, it requires that DLT is installed and the DLT module can be found in the
context of CMake.

Configuration
~~~~~~~~~~~~~

Static Configuration
^^^^^^^^^^^^^^^^^^^^

The Trace Connector can be configured statically over the
<<config-tracing,JSON configuration file>>. +

[float]
Example 1 (Minimal Configuration)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[source, bash]
----
{
    ...

    "tracing" :
    {
        "enable" : "true"
    },

    ...
----

This is the minimal configuration of the Trace Connector. This just enables the
tracing and all of the sent internal messages will be traced/forwarded to DLT.

[float]
Example 2 (Using Filters)
^^^^^^^^^^^^^^^^^^^^^^^^^

[source, bash]
----
{
    ...

    "tracing" :
    {
        "enable" : "true",
        "channels" :
        [
            {
                "name" : "My channel",
                "id" : "MC"
            }
        ],
        "filters" : [
            {
                "channel" : "MC",
                "matches" : [ { "service" : "0x1234", "instance" : "any", "method" : "0x80e8" } ],
                "type" : "positive"
            }
        ]
    },

    ...
----

As it is a positive filter, the example filter ensures that only messages
representing method '0x80e8' from instances of service '0x1234' will be
forwarded to the DLT. If it was specified as a negative filter, all messages
except messages representing method '0x80e8' from instances of service
'0x1234' would be forwarded to the DLT.

The general filter rules are:

* The default filter is a positive filter for all messages.
* The default filter is active on a channel as long as no other positive
filter is specified.
* Negative filters block matching messages. Negative filters overrule
positive filters. Thus, as soon as a messages matches a negative filter it
will not be forwarded.
* The identifier '0xffff' is a wildcard that matches any service, instance or method.
The keyword 'any' can be used as a replacement for '0xffff'.
* Wildcards must not be used within range filters.

Dynamic Configuration
^^^^^^^^^^^^^^^^^^^^^

The Trace Connector can also be configured dynamically over its interfaces.
You need to include '<vsomeip/trace.hpp>' to access its public interface.

[float]
Example:
^^^^^^^^

[source, bash]
----
    // get trace connector
    std::shared_ptr<vsomeip::trace::connector> its_connector
	= vsomeip::trace::connector::get();

    // add channel
    std::shared_ptr<vsomeip::trace::channel> its_channel
	= its_connector->create_channel("MC", "My channel");

    // add filter rule
    vsomeip::trace::match_t its_match
        = std::make_tuple(0x1234, 0xffff, 0x80e8);
    vsomeip::trace::filter_id_t its_filter_id
	= its_channel->add_filter(its_match, true);

    // init trace connector
    its_connector->init();

    // enable trace connector
    its_connector->set_enabled(true);

    // remove the filter
    its_channel->remove_filter(its_filter_id);
----

anchor:npdu[]

vsomeip nPDU feature
------------------

This is the add-on documentation for the nPDU feature, aka. _Zugverfahren_.

The nPDU feature can be used to reduce network load as it enables the vsomeip
stack to combine multiple vsomeip messages in one single ethernet frame.

Some general _important_ things regarding the nPDU feature first:

* Due to its nature the nPDU feature trades lower network load for speed.
* As the nPDU feature requires some settings which are not transmitted
through the service discovery, it's *not* sufficient anymore to have an json
file without a "services" section on the client side.
* As the client- and server-endpoints of a node are managed by the routing
 manager (which is the application entered at "routing" in the json file)
 the nPDU feature settings *always* have to be defined in the json file used by
 the application acting as routing manager.
* The nPDU feature timings are defined in milliseconds.
* Node internal communication over UNIX domain sockets is not affected by the
  nPDU feature.
* If the debounce times configuration for a method in the json file is missing
  or incomplete the default values are used: 2ms debounce time and 5ms max
  retention time. The global default values can be overwritten via the
  `npdu-default-timings` json object.

Configuration
~~~~~~~~~~~~~
There are two parameters specific for the nPDU feature:

* *debounce time*: minimal time between sending a message to the same method of
  a remote service over the same connection (src/dst address + src/dst port).
* *max retention time*: the maximum time which a message to the same method of a
  remote service over the same connection (src/dst address + src/dst port) is
  allowed to be buffered on sender side.

For more information please see the corresponding requirement documents.


The nPDU feature specific settings are configured in the json file in the
"services" section on service level in a special _debounce-times_ section:

[source, bash]
----
[...]
"services":
[
    {
        "service":"0x1000",
        "instance":"0x0001",
        "unreliable":"30509",
        "debounce-times":
        {
            // nPDU feature configuration for this
            // service here
        }
    }
],
[...]
----

Additionally nPDU default timings can be configured globally.

The global default timings can be overwritten via the `npdu-default-timings`
json object. For example the following configuration snippet shows how to set
all default timings to zero:

[source, bash]
----
{
    "unicast":"192.168.1.9",
    [...]
    "npdu-default-timings" : {
        "debounce-time-request" : "0",
        "debounce-time-response" : "0",
        "max-retention-time-request" : "0",
        "max-retention-time-response" : "0"
    },
    "routing":"[...]",
    "service-discovery": { [...] }
}
----


Example 1: One service with one method offered over UDP
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* The service is hosted on IP: 192.168.1.9.
* The service is offered on port 30509 via UDP.
* The service has the ID 0x1000
* The method has the ID 0x0001
* The client accesses the service from IP: 192.168.1.77

Service side
++++++++++++

* Debounce time for responses should have a:
** debounce time of 10 milliseconds
** maximum retention time of 100 milliseconds

[source, bash]
----
{
    "unicast":"192.168.1.9",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x0001",
            "unreliable":"30509",
            "debounce-times":
            {
                "responses": {
                    "0x1001" : {
                        "debounce-time":"10",
                        "maximum-retention-time":"100"
                    }
                }
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----
Client side
++++++++++++

* Debounce time for requests to the service on 192.168.1.9 should have a:
** debounce time of 20 milliseconds
** maximum retention time of 200 milliseconds

[source, bash]
----
{
    "unicast":"192.168.1.77",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x0001",
            "unicast":"192.168.1.9", // required to mark service as external
            "unreliable":"30509",
            "debounce-times":
            {
                "requests": {
                    "0x1001" : {
                        "debounce-time":"20",
                        "maximum-retention-time":"200"
                    }
                }
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----

Example 2: One service with two methods offered over UDP
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* The service is hosted on IP: 192.168.1.9.
* The service is offered on port 30509 via UDP.
* The service has the ID 0x1000
* The method has the ID 0x0001
* The second method has the ID 0x0002
* The client accesses the service from IP: 192.168.1.77

Service side
++++++++++++

* Debounce time for responses should have a:
** debounce time of 10 milliseconds for method 0x1001 and 20 for 0x1002
** maximum retention time of 100 milliseconds for method 0x1001 and 200 for 0x1002

[source, bash]
----
{
    "unicast":"192.168.1.9",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x0001",
            "unreliable":"30509",
            "debounce-times":
            {
                "responses": {
                    "0x1001" : {
                        "debounce-time":"10",
                        "maximum-retention-time":"100"
                    },
                    "0x1002" : {
                        "debounce-time":"20",
                        "maximum-retention-time":"200"
                    }
                }
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----
Client side
++++++++++++

* Debounce time for requests to the service on 192.168.1.9 should have a:
** debounce time of 20 milliseconds for method 0x1001 and 40 for 0x1002
** maximum retention time of 200 milliseconds for method 0x1001 and 400 for 0x1002

[source, bash]
----
{
    "unicast":"192.168.1.77",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x0001",
            "unicast":"192.168.1.9", // required to mark service as external
            "unreliable":"30509",
            "debounce-times":
            {
                "requests": {
                    "0x1001" : {
                        "debounce-time":"20",
                        "maximum-retention-time":"200"
                    },
                    "0x1002" : {
                        "debounce-time":"40",
                        "maximum-retention-time":"400"
                    }
                }
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----

Example 3: One service with one method offered over UDP and TCP
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* The service is hosted on IP: 192.168.1.9.
* The service is offered on port 30509 via UDP.
* The service is offered on port 30510 via TCP.
* The service has the ID 0x1000
* The method has the ID 0x0001
* The client accesses the service from IP: 192.168.1.77

Service side
++++++++++++

* Debounce time for responses should have a:
** debounce time of 10 milliseconds
** maximum retention time of 100 milliseconds
** TCP should use the same settings as UDP

[source, bash]
----
{
    "unicast":"192.168.1.9",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x0001",
            "unreliable":"30509",
            "reliable":
            {
                "port":"30510",
                "enable-magic-cookies":"false"
            },
            "debounce-times":
            {
                "responses": {
                    "0x1001" : {
                        "debounce-time":"10",
                        "maximum-retention-time":"100",
                    }
                }
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----
Client side
++++++++++++

* Debounce time for requests to the service on 192.168.1.9 should have a:
** debounce time of 20 milliseconds
** maximum retention time of 200 milliseconds
** TCP should use the same settings as UDP

[source, bash]
----
{
    "unicast":"192.168.1.77",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x0001",
            "unicast":"192.168.1.9", // required to mark service as external
            "unreliable":"30509",
            "reliable":
            {
                "port":"30510",
                "enable-magic-cookies":"false"
            },
            "debounce-times":
            {
                "requests": {
                    "0x1001" : {
                        "debounce-time":"20",
                        "maximum-retention-time":"200",
                    }
                }
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----


anchor:someiptp[]

SOME/IP TP
----------
With SOME/IP Transport Protocol (TP) it is possible to transport messages which
exceed the UDP payload size limit of 1400 byte. If enabled the message is
segmented and send in multiple UDP datagrams.

Example configuration:

* Service 0x1111/0x1 is hosted on 192.168.0.1 on UDP port 40000
* Client is running on 192.168.0.100
* The service has two methods with ID: 0x1 and 0x2 which require large requests
  and large responses. Additionally the service offers a field with ID 0x8001
  which requires a large payloads as well.
* The maximum payload size on service side should be limited to 5000 bytes.

Configuration service side:
[source, bash]
----
{
    "unicast":"192.168.0.1",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x1",
            "unreliable":"40000",
            "someip-tp": {
                "service-to-client": [
                    "0x1", "0x2", "0x8001"
                ]
            }
        }
    ],
    "max-payload-size-unreliable" : "5000",
    "routing":"[...]",
    "service-discovery": { [...] }
}
----

Configuration client side:

[source, bash]
----
{
    "unicast":"192.168.0.100",
    "logging": { [...] },
    "applications": [ [...] ],
    "services":
    [
        {
            "service":"0x1000",
            "instance":"0x1",
            "unicast":"192.168.0.1", // required to mark service as external
            "unreliable":"40000", // required to mark service as external
            "someip-tp": {
                "client-to-service": [
                    "0x1", "0x2"
                ]
            }
        }
    ],
    "routing":"[...]",
    "service-discovery": { [...] }
}
----

Tools
-----

vsomeip_ctrl
~~~~~~~~~~~~
anchor:vsomeip_ctrl[]
`vsomeip_ctrl` is a small utility which can be used to send SOME/IP messages
from the commandline. If a response arrives within 5 seconds the response will
be printed.

* It can be build via `vsomeip_ctrl` make target (`make vsomeip_ctrl`).
* The instance id of the target service has to be passed in hexadecimal
  notation.
* The complete message has to be passed in hexadecimal notation.
* See the `--help` parameter for available options.
* If `vsomeip_ctrl` is used to send messages to a remote service and no
 `routingmanagerd` is running on the local machine, make sure to pass a json
 configuration file where `vsomeip_ctrl` is set as routing manager via
 environment variable.
* If `vsomeip_ctrl` is used to send messages to a local service and no
 `routingmanagerd` is running on the local machine, make sure to use the same json
 configuration file as the local service.

Example: Calling method with method id 0x80e8 on service with service id 0x1234,
instance id 0x5678:
[source, bash]
----
./vsomeip_ctrl --instance 5678 --message 123480e800000015134300030100000000000009efbbbf576f726c6400
----

Example: Sending a message to service with service id 0x1234, instance id
0x5678 and method id 0x0bb8 via TCP
[source, bash]
----
./vsomeip_ctrl --tcp --instance 5678 --message 12340bb8000000081344000101010000
----