| /** |
| * \file libnetconf.h |
| * \author Radek Krejci <rkrejci@cesnet.cz> |
| * \author Michal Vasko <mvasko@cesnet.cz> |
| * \brief libnetconf2 main internal header. |
| * |
| * Copyright (c) 2015 CESNET, z.s.p.o. |
| * |
| * This source code is licensed under BSD 3-Clause License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * https://opensource.org/licenses/BSD-3-Clause |
| */ |
| |
| #ifndef NC_LIBNETCONF_H_ |
| #define NC_LIBNETCONF_H_ |
| |
| #include "config.h" |
| #include "netconf.h" |
| #include "log_p.h" |
| #include "session_p.h" |
| #include "messages_p.h" |
| |
| /* Tests whether string is empty or non-empty. */ |
| #define strisempty(str) ((str)[0] == '\0') |
| #define strnonempty(str) ((str)[0] != '\0') |
| |
| /** |
| * @mainpage About |
| * |
| * libnetconf2 is a NETCONF library in C handling NETCONF authentication and all NETCONF |
| * RPC communication both server and client-side. NETCONF datastore and session management is not a part of this library, |
| * but it helps a lot with the sessions. |
| * |
| * @section about-features Main Features |
| * |
| * - Creating SSH (using libssh) or TLS (using OpenSSL) authenticated NETCONF sessions. |
| * - Creating NETCONF sessions with a pre-established transport protocol |
| * (using this mechanism the communication can be tunneled through sshd(8), for instance). |
| * - Creating NETCONF Call Home sessions. |
| * - Creating, sending, receiving, and replying to RPCs. |
| * - Receiving notifications. |
| * |
| * - \todo Creating and sending notifications. |
| * |
| * @section about-license License |
| * |
| * Copyright (c) 2015-2016 CESNET, z.s.p.o. |
| * |
| * (The BSD 3-Clause License) |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * 3. Neither the name of the Company nor the names of its contributors |
| * may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| */ |
| |
| /** |
| * @page howto How To ... |
| * |
| * - @subpage howtoinit |
| * - @subpage howtoclient |
| * - @subpage howtoserver |
| * - @subpage howtoclientcomm |
| * - @subpage howtoservercomm |
| */ |
| |
| /** |
| * @page howtoinit Init and Thread-safety Information |
| * |
| * Before working with the library, it must be initialized using nc_client_init() |
| * or nc_server_init(). Optionally, a client can use nc_client_set_schema_searchpath() |
| * to set the path to a directory with modules that will be loaded from there if they |
| * could not be downloaded from the server (it does not support \<get-schema\>). |
| * However, to be able to create at least the \<get-schema\> RPC, this directory must |
| * contain the module _ietf-netconf-monitoring_. If this directory is not set, |
| * the default _libnetconf2_ schema directory is used that includes this module |
| * and a few others. |
| * |
| * Based on how the library was compiled, also _libssh_ and/or |
| * _libssh_/_libcrypto_ are initialized (for multi-threaded use) too. It is advised |
| * to compile _libnetconf2_, for instance, with TLS support even if you do not want |
| * to use _lnc2_ TLS functions, but only use _libssl/libcrypto_ functions in your |
| * application. You can then use _libnetconf2_ cleanup function and do not |
| * trouble yourself with the cleanup. |
| * |
| * To prevent any reachable memory at the end of your application, there |
| * are complementary destroy functions available. If your application is |
| * multi-threaded, call the destroy functions in the last thread, after all |
| * the other threads have ended. In every other thread you should call |
| * nc_thread_destroy() just before it exits. |
| * |
| * If _libnetconf2_ is used in accordance with this information, there should |
| * not be memory leaks of any kind at program exit. For thread-safety details |
| * of _libssh_, _libssl_, and _libcrypto_, please refer to the corresponding project |
| * documentation. _libnetconf2_ thread-safety information is below. |
| * |
| * Client is __NOT__ thread-safe and there is no access control in the client |
| * functions at all. Server is __MOSTLY__ thread-safe meaning you can set all the |
| * options simultaneously while listening for or accepting new sessions or |
| * polling the existing ones. It should even be safe to poll one session in |
| * several threads, but it is definitely discouraged. Generally, servers can |
| * use more threads without any problems as long as they keep their workflow sane |
| * (behavior such as freeing sessions only after no thread uses them or similar). |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_client.h__. |
| * |
| * - nc_client_init() |
| * - nc_client_destroy() |
| * |
| * - nc_client_set_schema_searchpath() |
| * - nc_client_get_schema_searchpath() |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_server_init() |
| * - nc_server_destroy() |
| * |
| * Available in both __nc_client.h__ and __nc_server.h__. |
| * |
| * - nc_thread_destroy() |
| */ |
| |
| /** |
| * @page howtoclient Client sessions |
| * |
| * To connect to a NETCONF server, a NETCONF session must be established, |
| * which requires a working transport session. It is possible to create |
| * NETCONF sessions with SSH (using _libssh_) or TLS (using _libssl/libcrypto_) |
| * as the underlying transport protocol. It is also possible to establish |
| * the transport protocol outside _libnetconf2_ and then provide these file |
| * descriptors (FD) for full NETCONF session creation. |
| * |
| * There are a lot of options for both an SSH and a TLS client. All of them |
| * have setters and getters so that there is no need to duplicate them in |
| * a client. |
| * |
| * SSH |
| * === |
| * |
| * Connecting to a server using SSH does not strictly require to set any |
| * options, there are sensible default values for all the basic ones. |
| * Except all the SSH options, optionally some authetication callbacks can be set, |
| * which are particulary useful in automated clients (passwords cannot be |
| * asked a user) or simply if any additional information is retrieved some |
| * other way than from standard terminal input. |
| * |
| * Having the default options or changing any unsuitable ones, there are 2 functions |
| * to use for a new server connection. nc_connect_ssh() is the standard function |
| * that creates sessions using the set options. If there are some options, which |
| * cannot be changed with the provided API, there is nc_connect_libssh() available. |
| * It requires a _libssh_ session, in which all the SSH options can be modified |
| * and even the connection established. This allows for full customization and |
| * should fit any specific situation. |
| * |
| * New NETCONF sessions can also be created on existing authenticated SSH sessions. |
| * There is a new SSH channel needed, on which the NETCONF session is then created. |
| * Use nc_connect_ssh_channel() for this purpose. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_client.h__. |
| * |
| * - nc_client_ssh_set_auth_hostkey_check_clb() |
| * - nc_client_ssh_set_auth_password_clb() |
| * - nc_client_ssh_set_auth_interactive_clb() |
| * - nc_client_ssh_set_auth_privkey_passphrase_clb() |
| * - nc_client_ssh_add_keypair() |
| * - nc_client_ssh_del_keypair() |
| * - nc_client_ssh_get_keypair_count() |
| * - nc_client_ssh_get_keypair() |
| * - nc_client_ssh_set_auth_pref() |
| * - nc_client_ssh_get_auth_pref() |
| * - nc_client_ssh_set_username() |
| * - nc_client_ssh_get_username() |
| * |
| * - nc_connect_ssh() |
| * - nc_connect_libssh() |
| * - nc_connect_ssh_channel() |
| * |
| * |
| * TLS |
| * === |
| * |
| * To connect to a server using TLS, there must be some client identification |
| * options set. Client must specify its certificate with a private key using |
| * nc_client_tls_set_cert_key_paths(). Also, the Certificate Authority of |
| * a server certificate must be considered trusted. Paths to all the trusted |
| * CA certificates can be set by nc_client_tls_set_trusted_ca_paths(). |
| * |
| * Then there are again 2 functions for connecting, nc_connect_tls() being |
| * the standard way of connecting. nc_connect_libssl() again enables |
| * to customize the TLS session in every way _libssl_ allows. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_client.h__. |
| * |
| * - nc_client_tls_set_cert_key_paths() |
| * - nc_client_tls_get_cert_key_paths() |
| * - nc_client_tls_set_trusted_ca_paths() |
| * - nc_client_tls_get_trusted_ca_paths() |
| * - nc_client_tls_set_crl_paths() |
| * - nc_client_tls_get_crl_paths() |
| * |
| * - nc_connect_tls() |
| * - nc_connect_libssl() |
| * |
| * |
| * FD |
| * == |
| * |
| * If you authenticated the connection using some tunneling software, you |
| * can pass its file descriptors to _libnetconf2_ using nc_connect_inout(), |
| * which will continue to establish a full NETCONF session. |
| * |
| * Funtions List |
| * ------------- |
| * |
| * Available in __nc_client.h__. |
| * |
| * - nc_connect_inout() |
| * |
| * |
| * Call Home |
| * ========= |
| * |
| * Call Home needs the same options set as standard SSH or TLS and the functions |
| * reflect it exactly. However, to accept a connection, the client must first |
| * specify addresses and ports, which to listen on by nc_client_ssh_ch_add_bind_listen() |
| * and nc_client_tls_ch_add_bind_listen(). Then connections can be |
| * accepted using nc_accept_callhome(). |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_client.h__. |
| * |
| * - nc_client_ssh_ch_set_auth_hostkey_check_clb() |
| * - nc_client_ssh_ch_set_auth_password_clb() |
| * - nc_client_ssh_ch_set_auth_interactive_clb() |
| * - nc_client_ssh_ch_set_auth_privkey_passphrase_clb() |
| * - nc_client_ssh_ch_add_bind_listen() |
| * - nc_client_ssh_ch_del_bind() |
| * - nc_client_ssh_ch_add_keypair() |
| * - nc_client_ssh_ch_del_keypair() |
| * - nc_client_ssh_ch_get_keypair_count() |
| * - nc_client_ssh_ch_get_keypair() |
| * - nc_client_ssh_ch_set_auth_pref() |
| * - nc_client_ssh_ch_get_auth_pref() |
| * - nc_client_ssh_ch_set_username() |
| * - nc_client_ssh_ch_get_username() |
| * |
| * - nc_client_tls_ch_add_bind_listen() |
| * - nc_client_tls_ch_del_bind() |
| * - nc_client_tls_ch_set_cert_key_paths() |
| * - nc_client_tls_ch_get_cert_key_paths() |
| * - nc_client_tls_ch_set_trusted_ca_paths() |
| * - nc_client_tls_ch_get_trusted_ca_paths() |
| * - nc_client_tls_ch_set_crl_paths() |
| * - nc_client_tls_ch_get_crl_paths() |
| * |
| * - nc_accept_callhome() |
| * |
| * |
| * Cleanup |
| * ======= |
| * |
| * These options and the schema searchpath are stored in dynamically |
| * allocated memory. They are freed as a part of [destroying the client](@ref howtoinit). |
| */ |
| |
| /** |
| * @page howtoserver Server sessions |
| * |
| * Init |
| * ==== |
| * |
| * Server takes an argument for its [initialization function](@ref howtoinit). |
| * In it, you set the server context, which determines what modules it |
| * supports and what capabilities to advertise. Few capabilities that |
| * cannot be learnt from the context are set with separate functions |
| * nc_server_set_capab_withdefaults() and nc_server_set_capab_interleave(). |
| * Timeout for receiving the _hello_ message on a new session can be set |
| * by nc_server_set_hello_timeout() and the timeout for disconnecting |
| * an inactive session by nc_server_set_idle_timeout(). |
| * |
| * Context does not only determine server modules, but its overall |
| * functionality as well. For every RPC the server should support, |
| * an nc_rpc_clb callback should be set on that node in the context using nc_set_rpc_callback(). |
| * Server then calls these as appropriate [during poll](@ref howtoservercomm). |
| * |
| * Just like in the [client](@ref howtoclient), you can let _libnetconf2_ |
| * establish SSH or TLS transport or do it yourself and only provide the file |
| * descriptors of the connection. |
| * |
| * Server options can be only set, there are no getters. |
| * |
| * To be able to accept any connections, general endpoints must first be added |
| * with nc_server_add_endpt(). They can then be modified to accept either SSH, TLS, |
| * or both kinds of sessions. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_server_set_capab_withdefaults() |
| * - nc_server_set_capab_interleave() |
| * - nc_server_set_hello_timeout() |
| * - nc_server_set_idle_timeout() |
| * |
| * - nc_server_add_endpt() |
| * - nc_server_del_endpt() |
| * |
| * |
| * SSH |
| * === |
| * |
| * To start listening for SSH connections you must set the address |
| * and port to listen on for a particular endpoint using nc_server_ssh_endpt_set_address() |
| * and nc_server_endpt_set_port(). |
| * To then successfully accept an SSH session you must also set the host key using |
| * nc_server_ssh_endpt_add_hostkey(). |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_server_ssh_endpt_set_address() |
| * - nc_server_ssh_endpt_set_port() |
| * |
| * - nc_server_ssh_endpt_add_hostkey() |
| * - nc_server_ssh_endpt_del_hostkey() |
| * - nc_server_ssh_endpt_set_banner() |
| * - nc_server_ssh_endpt_set_auth_methods() |
| * - nc_server_ssh_endpt_set_auth_attempts() |
| * - nc_server_ssh_endpt_set_auth_timeout() |
| * - nc_server_ssh_endpt_add_authkey() |
| * - nc_server_ssh_endpt_del_authkey() |
| * |
| * |
| * TLS |
| * === |
| * |
| * TLS works with endpoints too, but its options differ |
| * significantly from the SSH ones, especially in the _cert-to-name_ |
| * options that TLS uses to derive usernames from client certificates. |
| * So, after starting listening on an endpoint by calling nc_server_tls_endpt_set_address() |
| * and nc_server_tls_endpt_set_port(), |
| * you need to set the server certificate (nc_server_tls_endpt_set_cert() |
| * or nc_server_tls_endpt_set_cert_path()) and private key (nc_server_tls_endpt_set_key() |
| * or nc_server_tls_endpt_set_key_path()). |
| * |
| * To accept client certificates, they must first be considered trusted, |
| * which you have three ways of achieving. You can add each of their Certificate Authority |
| * certificates to the trusted ones or mark a specific client certificate |
| * as trusted using nc_server_tls_endpt_add_trusted_cert(). Lastly, you can |
| * set paths with all the trusted CA certificates with nc_server_tls_endpt_set_trusted_ca_paths(). |
| * |
| * Then, from each trusted client certificate a username must be derived |
| * for the NETCONF session. This is accomplished by finding a matching |
| * _cert-to-name_ entry. They are added using nc_server_tls_endpt_add_ctn(). |
| * |
| * If you need to remove trusted certificates, you can do so with nc_server_tls_endpt_del_trusted_cert(). |
| * To clear all Certificate Revocation Lists use nc_server_tls_endpt_clear_crls(). |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_server_tls_endpt_set_address() |
| * - nc_server_tls_endpt_set_port() |
| * |
| * - nc_server_tls_endpt_set_cert() |
| * - nc_server_tls_endpt_set_cert_path() |
| * - nc_server_tls_endpt_set_key() |
| * - nc_server_tls_endpt_set_key_path() |
| * - nc_server_tls_endpt_add_trusted_cert() |
| * - nc_server_tls_endpt_add_trusted_cert_path() |
| * - nc_server_tls_endpt_set_trusted_ca_paths() |
| * - nc_server_tls_endpt_del_trusted_cert(); |
| * - nc_server_tls_endpt_set_crl_paths() |
| * - nc_server_tls_endpt_clear_crls() |
| * - nc_server_tls_endpt_add_ctn() |
| * - nc_server_tls_endpt_del_ctn() |
| * |
| * FD |
| * == |
| * |
| * If you used a tunneling software, which does its own authentication, |
| * you can accept a NETCONF session on its file descriptors with |
| * nc_accept_inout(). |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_accept_inout() |
| * |
| * |
| * Call Home |
| * ========= |
| * |
| * Call Home does not work with endpoints like standard sessions. |
| * Connecting is similar to the [client](@ref howtoclient), just call |
| * nc_connect_callhome_ssh() or nc_connect_callhome_tls(). Any options |
| * must be reset manually by nc_server_ssh_ch_clear_opts() |
| * or using nc_server_tls_ch_del_trusted_cert() and nc_server_tls_ch_clear_crls() |
| * after another Call Home session (with different options than the previous one) |
| * is to be established. Also, monitoring of these sessions is up to the application. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_connect_callhome_ssh() |
| * - nc_connect_callhome_tls() |
| * |
| * - nc_server_ssh_ch_add_hostkey() |
| * - nc_server_ssh_ch_del_hostkey() |
| * - nc_server_ssh_ch_set_banner() |
| * - nc_server_ssh_ch_set_auth_methods() |
| * - nc_server_ssh_ch_set_auth_attempts() |
| * - nc_server_ssh_ch_set_auth_timeout() |
| * - nc_server_ssh_ch_add_authkey() |
| * - nc_server_ssh_ch_del_authkey() |
| * - nc_server_ssh_ch_clear_opts() |
| * |
| * - nc_server_tls_ch_set_cert() |
| * - nc_server_tls_ch_set_cert_path() |
| * - nc_server_tls_ch_set_key() |
| * - nc_server_tls_ch_set_key_path() |
| * - nc_server_tls_ch_add_trusted_cert() |
| * - nc_server_tls_ch_add_trusted_cert_path() |
| * - nc_server_tls_ch_set_trusted_ca_paths() |
| * - nc_server_tls_ch_del_trusted_cert(); |
| * - nc_server_tls_ch_set_crl_paths() |
| * - nc_server_tls_ch_clear_crls() |
| * - nc_server_tls_ch_add_ctn() |
| * - nc_server_tls_ch_del_ctn() |
| * - nc_server_tls_ch_clear_opts() |
| * |
| * |
| * Connecting And Cleanup |
| * ====================== |
| * |
| * When accepting connections with nc_accept(), all the endpoints are examined |
| * and the first with a pending connection is used. To remove all |
| * the endpoints and free any used dynamic memory, [destroy](@ref howtoinit) the server. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_accept() |
| */ |
| |
| /** |
| * @page howtoclientcomm Client communication |
| * |
| * To send RPCs on a session, you simply create an RPC, send it using nc_send_rpc(), |
| * and then wait for a reply using nc_recv_reply(). If you are subscribed, there are 2 ways |
| * of receiving notifications. Either you wait for them the same way |
| * as for standard replies with nc_recv_notif() or you create a dispatcher |
| * with nc_recv_notif_dispatch() that asynchronously (in a separate thread) |
| * reads notifications and passes them to your callback. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_client.h__. |
| * |
| * - nc_rpc_act_generic() |
| * - nc_rpc_act_generic_xml() |
| * - nc_rpc_getconfig() |
| * - nc_rpc_edit() |
| * - nc_rpc_copy() |
| * - nc_rpc_delete() |
| * - nc_rpc_lock() |
| * - nc_rpc_unlock() |
| * - nc_rpc_get() |
| * - nc_rpc_kill() |
| * - nc_rpc_commit() |
| * - nc_rpc_discard() |
| * - nc_rpc_cancel() |
| * - nc_rpc_validate() |
| * - nc_rpc_getschema() |
| * - nc_rpc_subscribe() |
| * |
| * - nc_send_rpc() |
| * - nc_recv_reply() |
| * - nc_recv_notif() |
| * - nc_recv_notif_dispatch() |
| */ |
| |
| /** |
| * @page howtoservercomm Server communication |
| * |
| * Once at least one session is established, an nc_pollsession structure |
| * should be created with nc_ps_new(), filled with the session using |
| * nc_ps_add_session() and finally polled with nc_ps_poll(). Based on |
| * the return value from the poll, further actions can be taken. More |
| * sessions can be polled at the same time and any requests received on |
| * the sessions are [handled internally](@ref howtoserver). |
| * |
| * If an SSH NETCONF session asks for a new channel, you can accept |
| * this request with nc_ps_accept_ssh_channel() or nc_session_accept_ssh_channel() |
| * depending on the structure you want to use as the argument. |
| * |
| * Functions List |
| * -------------- |
| * |
| * Available in __nc_server.h__. |
| * |
| * - nc_ps_new() |
| * - nc_ps_add_session() |
| * - nc_ps_del_session() |
| * - nc_ps_session_count() |
| * - nc_ps_free() |
| * |
| * - nc_ps_poll() |
| * - nc_ps_clear() |
| * - nc_ps_accept_ssh_channel() |
| * - nc_session_accept_ssh_channel() |
| */ |
| |
| #endif /* NC_LIBNETCONF_H_ */ |