+
+Using SILC Client Library
+
+
+Introduction
+
+
+SILC Client library is a full featured SILC Client protocol implementation.
+The library has been designed to be complete SILC client without actual
+user interface. The library provides the API for the appliation which
+it can use to implement generally whatever user interface it wants. The
+SILC Client Library recides in the lib/silcclient/ directory. It uses
+common and core component of SILC protocol from the lib/silccore, SKE
+from lib/silcske and general utility routines from lib/silcutil.
+
+
+The `silcclient.h' file defines the function prototypes that application
+must implement in order to be able to create the user interface with the
+library. The idea is that the application can implement whatever user
+interface routines in the functions and display the data whatever way
+it wants. The library is entirely transparent to the user interface and
+it does not include any user interface specific issues such as window
+handling or item handling on the screen etc. These does not interest
+the library. The `silcclient.h' and `silcclient_entry.h' also defines the
+client libary interface the application can call. The interface includes
+for example functions for sending channel and private messages, client and
+channel retrieval and other utility functions.
+
+
+Including Library Headers
+
+
+Your application must include the following includes in your sources to
+get access all SILC Client Library routines:
+
+
+
+#include "silc.h"
+#include "silcclient.h"
+
+
+
+
+Creating Client
+
+
+The client is context or entity based, so several client entitites can
+be created in the application if needed. However, it should be noted
+that they are completely independent from each other and can be seen
+as different applications. Usually only one client entity is needed
+per application.
+
+
+The client object is SilcClient which is usually allocated in following
+manner:
+
+
+ SilcClient client = silc_client_alloc(&ops, params, context, NULL);
+
+
+`ops' is the static structure of client operations that library will call.
+`context' can be some application specific context that will be saved into
+the SilcClient object. It is up to the caller to free this context.
+SilcClient is always passed to the application thus the application
+specific context can be retrieved from the SilcClient object.
+
+
+`ops' can be defined for example as follows:
+
+
+
+SilcClientOperations ops = {
+ silc_say,
+ silc_channel_message,
+ silc_private_message,
+ silc_notify,
+ silc_command,
+ silc_command_reply,
+ silc_get_auth_method,
+ silc_verify_public_key,
+ silc_ask_passphrase,
+ silc_key_agreement,
+ silc_file_transfer,
+};
+
+
+
+Please see the `client_ops_example.c' source file in lib/silcclient/
+directory for predefined structure and stub functions for your
+convenience. It is provided for programmers so that they can copy
+it and use it directly in their application.
+
+
+
+Initializing the Client
+
+
+The client must be initialized before running. The client is initialized
+simply by calling silc_client_init function:
+
+
+ silc_client_init(client, username, hostname, realname,
+ foo_client_running, foo_ctx);
+
+
+which then initializes the client library for the `client'. The `username'
+and `hostname' pointers are required. The `foo_client_running' with
+`foo_ctx' in this example will be called by the client library after the
+client is up and running. After you receive this callback you may start
+using other API functions, such as creating connection to remote server.
+
+
+
+Running the Client
+
+
+The client is run by calling silc_client_run. The function will call
+the scheduler from utility library that will be run until the program is
+ended. When silc_client_run returns the application is ended. Thus,
+to run the client, call:
+
+
+ silc_client_run(client);
+
+
+Usually application may do some other initializations before calling
+this function. For example before calling this function application
+should initialize the user interface.
+
+
+
+Running the Client in GUI application
+
+
+Many GUI applications has their own main loop or event loop, which they
+would like to use or are forced to use by the underlaying system. If you
+are developing for example GUI application on Unix system, and you are
+using GTK+ or QT as GUI library you would probably like to use their own
+main loop. SILC Client can be run under external main loop as well. The
+interface provides a function silc_client_run_one which will run the
+client library once, and returns immediately. During that running it can
+process incoming data and send outgoing data, but it is guaranteed that it
+will not block the calling process.
+
+
+It is suggested that you would call this function as many times in a
+second as possible to provide smooth action for the client library. You
+can use an timeout task, or an idle task provided by your GUI library to
+accomplish this. After you have initialized the client library with
+silc_client_init, you should register the timeout task or idle task that
+will call the silc_client_run_one periodically.
+
+
+For Win32 the silc_client_run can be used instead of using the Windows's
+own event loop. However, if you would like to use the silc_client_run_one
+also on Win32 system it is possible.
+
+
+
+Running Client in GTK--
+
+
+Here is a short example how to run the SILC Client libary under the
+Gnome/GTK--'s main loop:
+
+
+
+gint YourClass::silc_scheduler()
+{
+ // Run the SILC client once, and return immediately. This function
+ // is called every 50 milliseconds by the Gnome main loop, to process
+ // SILC stuff. This function will read data, and write data to network,
+ // etc. Makes the client library tick! :)
+ silc_client_run_one(silc_client);
+ return 1;
+}
+
+
+
+then, during initialization of the SILC Client call:
+
+
+
+// Setup SILC scheduler as timeout task. This will handle the SILC
+// client library every 50 milliseconds. It will actually make the
+// SILC client work on background.
+Gnome::Main::timeout.connect(slot(this, &YourClass::silc_scheduler), 50);
+
+
+
+This will call the function silc_scheduler every 50 millisecconds, which
+on the otherhand will call silc_client_run_one, which will make the SILC
+Client library work on the background of the GUI application.
+
+
+
+Creating Connection to Server
+
+
+After your client is up and running you may create connection to remote
+SILC server. It is done simply by calling:
+
+
+ silc_client_connect_to_server(client, ¶ms,
+ public_key, private_key,
+ remote_host, remote_port,
+ foo_connected_cb, foo_ctx);
+
+
+The function will create the connection asynchronously to the server, ie.
+the function will return before the actual connection is created. The
+`foo_connected_cb' will be called once the connection has been established.
+The `params' may be NULL but it may be used to provide additional parameters
+to the connecting. For example it is possible to set the initial nickname
+you would like to use into the `params'.
+
+
+
+Debugging
+
+
+Being able to debug what you have coded is important when troubles occurs
+during coding, and they always do. SILC supports extensive debugging
+capabilities which are also available for client library user. You should
+have compiled the Toolkit with --enable-debug option so that run-time
+debugging is enabled.
+
+
+Then, to say in your application you would like to use the debugging use
+the SILC_DEBUG macro. Put this macro to your main header file, or
+some other file that needs the debugging enabled. After using this macro
+you are able to use the debugging routines provided by the SILC Toolkit.
+Note that, the Toolkit library must be compiled with --enable-debug for
+this macro to have any effect.
+
+
+To turn on the run-time debugging call function silc_log_debug with TRUE
+value. To see packet hexdumps you can call also silc_log_debug_hexdump
+with TRUE value. Hexdumps can create more debug log so not setting it
+to TRUE by default is probably best. To get debug messages out of specific
+modules you can set a debug string with silc_log_set_debug_string function.
+The function takes regex string as argument, for example:
+
+
+
+ silc_log_debug(TRUE);
+ silc_log_set_debug_string("*");
+
+
+
+This piece of code turns on the debugging and sets "*" as debug string. This
+means that all debug messages are printed. To get debugging out of only
+for example SILC Client Library the debug string could be "silc_client*".
+The debug string matches to function names and filenames so it is possible
+to get debugging out of specific files, and specific functions. Other
+examples could be:
+
+
+
+ silc_log_set_debug_string("silc_client*,*sock*,*ske*");
+
+
+
+By default, all debug messages are printed to standard error output (stderr).
+If you want to redirect the debug messages somewhere else you can set your
+own debug callback with silc_log_set_debug_callbacks function:
+
+
+
+ silc_log_set_debug_callbacks(my_debug_callback, my_context, my_hexdump_callback, my_context);
+
+
+
+See the lib/silcutil/silclog.h for definition of the callbacks. See the
+same file for other logging and debugging information.
+
+
+You can also use SILC debugging capabilities in your own application. To
+produce debug messages you can use SILC_LOG_DEBUG and SILC_LOG_HEXDUMP
+macros in your application. The SILC_LOG_DEBUG can print out normal debug
+messages with variable argument list, for example:
+
+
+
+ SILC_LOG_DEBUG(("Start"));
+ SILC_LOG_DEBUG(("Packet length %d", packet_len));
+ SILC_LOG_DEBUG(("The remote is %s on %d", sock->ip, sock->port));
+
+
+
+The SILC_LOG_HEXDUMP macro can be used dump data which couldn't be printed
+out otherwise, for example binary data.
+
+
+
+ SILC_LOG_HEXDUMP(("Packet"), packet->data, packet->len);
+ SILC_LOG_HEXDUMP(("Packet, size=%d", size), packet->data, packet->len);
+
+
+
+Note that the variable arguments in SILC_LOG_HEXDUMP are before the second
+last parenthesis, and the last two arguments are the data, and its length that
+are hexdumped.
+
+ |
+ 
SILC Toolkit Reference Manual
Introduction to SILC RNG