all MAINTENANCE server functions documented, minor function changes
diff --git a/src/session_server.h b/src/session_server.h
index 21b5fbd..8c7bc7c 100644
--- a/src/session_server.h
+++ b/src/session_server.h
@@ -29,94 +29,379 @@
 #include "session.h"
 #include "netconf.h"
 
+/**
+ * @brief Prototype of callbacks that are called if some RPCs are received.
+ *
+ * If \p session termination reason is changed in the callback, one last reply
+ * is sent and then the session is considered invalid.
+ *
+ * @param[in] rpc Parsed client RPC request.
+ * @param[in] session Session the RPC arrived on.
+ * @return Server reply. If NULL, an operation-failed error will be sent to the client.
+ */
 typedef struct nc_server_reply *(*nc_rpc_clb)(struct lyd_node *rpc, struct nc_session *session);
 
+/**
+ * @brief Set the termination reason for a session.
+ *
+ * @param[in] session Session to modify.
+ * @param[in] reason Reason of termination.
+ */
+void nc_session_set_term_reason(struct nc_session *session, NC_SESSION_TERM_REASON reason);
+
+/**
+ * @brief Initialize the server using a libyang context.
+ *
+ * The context is not modified internally, only its dictionary is used for holding
+ * all the strings.
+ *
+ * Server capabilities are generated based on its content. Changing the context
+ * in ways that result in changed capabilities (adding models, changing features)
+ * is discouraged after sessions are established as it is not possible to change
+ * capabilities of a session.
+ *
+ * This context can safely be destroyed only after calling the last libnetconf2
+ * function in an application.
+ *
+ * Supported RPCs of models in the context are expected to have the private field
+ * in the corresponding RPC schema node set to a nc_rpc_clb function callback.
+ * This callback is called by nc_ps_poll() if the particular RPC request is
+ * received. Callbacks for ietf-netconf:get-schema (supporting YANG and YIN format
+ * only) and ietf-netconf:close-session are set internally if left unset.
+ *
+ * Access to the context in libnetconf2 functions is not managed in any way,
+ * the application is responsible for handling it in a thread-safe manner.
+ *
+ * @param[in] ctx Core NETCONF server context.
+ * @return 0 on success, -1 on error.
+ */
 int nc_server_init(struct ly_ctx *ctx);
 
+/**
+ * @brief Set the with-defaults capability extra parameters.
+ *
+ * For the capability to be actually advertised, the server context must also
+ * include the ietf-netconf-with-defaults model.
+ *
+ * Changing this option has the same ill effects as changing capabilities while
+ * sessions are already established.
+ *
+ * @param[in] basic_mode basic-mode with-defaults parameter.
+ * @param[in] also_supported NC_WD_MODE bit array, also-supported with-defaults
+ * parameter.
+ * @return 0 on success, -1 on error.
+ */
 int nc_server_set_capab_withdefaults(NC_WD_MODE basic_mode, int also_supported);
 
-int nc_server_set_capab_interleave(int interleave_support);
+/**
+ * @brief Set the interleave capability.
+ *
+ * For the capability to be actually advertised, the server context must also
+ * include the nc-notifications model.
+ *
+ * Changing this option has the same ill effects as changing capabilities while
+ * sessions are already established.
+ *
+ * @param[in] interleave_support 1 to suport interleave, 0 to not.
+ */
+void nc_server_set_capab_interleave(int interleave_support);
 
-int nc_server_set_hello_timeout(uint16_t hello_timeout);
+/**
+ * @brief Set server timeout for receiving a hello message.
+ *
+ * @param[in] hello_timeout Hello message timeout. 0 for infinite waiting.
+ */
+void nc_server_set_hello_timeout(uint16_t hello_timeout);
 
-int nc_server_set_idle_timeout(uint16_t idle_timeout);
+/**
+ * @brief Set server timeout for dropping an idle session.
+ *
+ * @param[in] idle_timeout Idle session timeout. 0 to never drop a session
+ * because of inactivity.
+ */
+void nc_server_set_idle_timeout(uint16_t idle_timeout);
 
-int nc_server_set_max_sessions(uint16_t max_sessions);
+/**
+ * @brief Accept a new session on a pre-established transport session.
+ *
+ * @param[in] fdin File descriptor to read (unencrypted) XML data from.
+ * @param[in] fdout File descriptor to write (unencrypted) XML data to.
+ * @param[in] username NETCONF username as provided by the transport protocol.
+ * @param[out] session New session on success.
+ * @return 0 on success, -1 on error.
+ */
+int nc_accept_inout(int fdin, int fdout, const char *username, struct nc_session **session);
 
-struct nc_session *nc_accept_inout(int fdin, int fdout, const char *username);
-
+/**
+ * @brief Create an empty structure for polling sessions.
+ *
+ * @return Empty pollsession structure, NULL on error.
+ */
 struct nc_pollsession *nc_ps_new(void);
 
+/**
+ * @brief Free a pollsession structure.
+ *
+ * @param[in] ps Pollsession structure to free.
+ */
 void nc_ps_free(struct nc_pollsession *ps);
 
+/**
+ * @brief Add a session to a pollsession structure.
+ *
+ * @param[in] ps Pollsession structure to modify.
+ * @param[in] session Session to add to \p ps.
+ * @return 0 on success, -1 on error.
+ */
 int nc_ps_add_session(struct nc_pollsession *ps, struct nc_session *session);
 
+/**
+ * @brief Remove a session from a pollsession structure.
+ *
+ * @param[in] ps Pollsession structure to modify.
+ * @param[in] session Session to remove from \p ps.
+ * @return 0 on success, 1 if not found, -1 on error.
+ */
 int nc_ps_del_session(struct nc_pollsession *ps, struct nc_session *session);
 
-/* -1 error, 0 timeout, 1 rpcs, 2 session status change */
+/**
+ * @brief Poll sessions and process any received RPCs.
+ *
+ * All the sessions must be running. If a session fails causing it to change its
+ * status, it can be learnt from the return value. Only one event (new RPC, TODO
+ * new SSH channel request) on one session is handled in one function call.
+ *
+ * @param[in] ps Pollsession structure to use.
+ * @param[in] timeout Poll timeout. 0 for non-blocking call, -1 for infinite waiting.
+ * @return 0 on elapsed timeout, 1 if some RPC were processed, 2 if a session from
+ * \p ps changed its status (was invalidated), -1 on error.
+ */
 int nc_ps_poll(struct nc_pollsession *ps, int timeout);
 
 #if defined(ENABLE_SSH) || defined(ENABLE_TLS)
 
+/**
+ * @brief Add a new server bind and start listening on it.
+ *
+ * @param[in] address IP address to bind to.
+ * @param[in] port Port to bind to.
+ * @param[in] ti Expected transport protocol of incoming connections.
+ * @return 0 on success, -1 on error.
+ */
 int nc_server_add_bind_listen(const char *address, uint16_t port, NC_TRANSPORT_IMPL ti);
 
+/**
+ * @brief Stop listening on and remove a server bind.
+ *
+ * @param[in] address IP address the bind was bound to. NULL matches all the addresses.
+ * @param[in] port Port the bind was bound to. NULL matches all the ports.
+ * @param[in] ti Expected transport. 0 matches all.
+ * @return 0 on success, -1 on not finding any match.
+ */
 int nc_server_del_bind(const char *address, uint16_t port, NC_TRANSPORT_IMPL ti);
 
-void nc_server_destroy_binds(void);
-
-struct nc_session *nc_accept(int timeout);
+/**
+ * @brief Accept new sessions on all the listening binds.
+ *
+ * @param[in] timeout Timeout for receiving a new connection, 0 for non-blocking call,
+ * -1 for infinite waiting.
+ * @param[out] session New session on success.
+ * @return 1 on success, 0 on timeout, -1 or error.
+ */
+int nc_accept(int timeout, struct nc_session **session);
 
 #endif /* ENABLE_SSH || ENABLE_TLS */
 
 #ifdef ENABLE_SSH
 
-/* one for each key */
-int nc_ssh_server_set_hostkey(const char *key_path);
+/**
+ * @brief Set SSH host keys the server will identify itself with. Each of RSA, DSA, and
+ * ECDSA key can be set. If the particular type was already set, it is replaced.
+ *
+ * @param[in] privkey_path Path to a private key.
+ * @return 0 on success, -1 on error.
+ */
+int nc_ssh_server_set_hostkey(const char *privkey_path);
 
+/**
+ * @brief Set SSH banner the server will send to every client.
+ *
+ * @param[in] banner SSH banner.
+ * @return 0 on success, -1 on error.
+ */
 int nc_ssh_server_set_banner(const char *banner);
 
+/**
+ * @brief Set accepted SSH authentication methods. All (publickey, password, interactive)
+ * are supported by default.
+ *
+ * @param[in] auth_methods Accepted authentication methods bit field of NC_SSH_AUTH_TYPE.
+ * @return 0 on success, -1 on error.
+ */
 int nc_ssh_server_set_auth_methods(int auth_methods);
 
+/**
+ * @brief Set SSH authentication attempts of every client. 3 by default.
+ *
+ * @param[in] auth_attempts Failed authentication attepmts before a client is dropped.
+ * @return 0 on success, -1 on error.
+ */
 int nc_ssh_server_set_auth_attempts(uint16_t auth_attempts);
 
+/**
+ * @brief Set SSH authentication timeout. 10 seconds by default.
+ *
+ * @param[in] auth_timeout Number of seconds before an unauthenticated client is dropped.
+ * @return 0 on success, -1 on error.
+ */
 int nc_ssh_server_set_auth_timeout(uint16_t auth_timeout);
 
-int nc_ssh_server_add_authkey(const char *keypath, const char *username);
+/**
+ * @brief Add an authorized client SSH public key. This public key can be used for
+ * publickey authentication afterwards.
+ *
+ * @param[in] pubkey_path Path to the public key.
+ * @param[in] username Username that the client with the public key must use.
+ * @return 0 on success, -1 on error.
+ */
+int nc_ssh_server_add_authkey(const char *pubkey_path, const char *username);
 
-int nc_ssh_server_del_authkey(const char *keypath, const char *username);
+/**
+ * @brief Remove an authorized client SSH public key.
+ *
+ * @param[in] pubkey_path Path to an authorized public key. NULL matches all the keys.
+ * @param[in] username Username for an authorized public key. NULL matches all the usernames.
+ * @return 0 on success, -1 on not finding any match.
+ */
+int nc_ssh_server_del_authkey(const char *pubkey_path, const char *username);
 
+/**
+ * @brief Free all the various SSH server options.
+ */
 void nc_ssh_server_free_opts(void);
 
+/* TODO remove */
 struct nc_session *nc_accept_ssh_channel(struct nc_session *session, int timeout);
 
 #endif /* ENABLE_SSH */
 
 #ifdef ENABLE_TLS
 
+/**
+ * @brief Set server TLS certificate. Alternative to nc_tls_server_set_cert_path().
+ * There can only be one certificate for each key type, it is replaced if already set.
+ *
+ * @param[in] cert Base64-encoded certificate in ASN.1 DER encoding.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_set_cert(const char *cert);
 
+/**
+ * @brief Set server TLS certificate. Alternative to nc_tls_server_set_cert().
+ * There can only be one certificate for each key type, it is replaced if already set.
+ *
+ * @param[in] cert_path Path to a certificate file in PEM format.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_set_cert_path(const char *cert_path);
 
+/**
+ * @brief Set server TLS private key matching the certificate.
+ * Alternative to nc_tls_server_set_key_path(). There can only be one of every key
+ * type, it is replaced if already set.
+ *
+ * @param[in] privkey Base64-encoded certificate in ASN.1 DER encoding.
+ * @param[in] is_rsa Whether \p privkey are the data of an RSA (1) or DSA (0) key.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_set_key(const char *privkey, int is_rsa);
 
+/**
+ * @brief Set server TLS private key matching the certificate.
+ * Alternative to nc_tls_server_set_key_path(). There can only be one of every key
+ * type, it is replaced if already set.
+ *
+ * @param[in] privkey_path Path to a private key file in PEM format.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_set_key_path(const char *privkey_path);
 
+/**
+ * @brief Add a trusted certificate. Can be both a CA or a client one.
+ *
+ * @param[in] cert Base64-enocded certificate in ASN.1DER encoding.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_add_trusted_cert(const char *cert);
 
+/**
+ * @brief Add a trusted certificate. Can be both a CA or a client one.
+ *
+ * @param[in] cert_path Path to a trusted certificate file in PEM format.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_add_trusted_cert_path(const char *cert_path);
 
+/**
+ * @brief Set trusted Certificate Authority certificate locations. There can only be
+ * one file and one directory, they are replaced if already set.
+ *
+ * @param[in] cacert_file_path Path to a trusted CA cert store file in PEM format.
+ * Can be NULL.
+ * @param[in] cacert_dir_path Path to a trusted CA cert store hashed directory
+ * (c_rehash utility can be used to create hashes) with PEM files. Can be NULL.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_set_trusted_cacert_locations(const char *cacert_file_path, const char *cacert_dir_path);
 
+/**
+ * @brief Destroy and clean all the set certificates and private keys. CRLs and
+ * CTN entries are not affected.
+ */
 void nc_tls_server_destroy_certs(void);
 
+/**
+ * @brief Set Certificate Revocation List locations. There can only be one file
+ * and one directory, they are replaced if already set.
+ *
+ * @param[in] crl_file_path Path to a CRL store file in PEM format. Can be NULL.
+ * @param[in] crl_dir_path Path to a CRL store hashed directory (c_rehash utility
+ * can be used to create hashes) with PEM files. Can be NULL.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_set_crl_locations(const char *crl_file_path, const char *crl_dir_path);
 
+/**
+ * @brief Destroy and clean CRLs. Certificates, priavte keys, and CTN entries are
+ * not affected.
+ */
 void nc_tls_server_destroy_crls(void);
 
+/**
+ * @brief Add a Cert-to-name entry.
+ *
+ * @param[in] id Priority of the entry.
+ * @param[in] fingerprint Matching certificate fingerprint.
+ * @param[in] map_type Type of username-certificate mapping.
+ * @param[in] name Specific username if \p map_type == NC_TLS_CTN_SPECIFED. Must be NULL otherwise.
+ * @return 0 on success, -1 on error.
+ */
 int nc_tls_server_add_ctn(uint32_t id, const char *fingerprint, NC_TLS_CTN_MAPTYPE map_type, const char *name);
 
+/**
+ * @brief Remove a Cert-to-name entry.
+ *
+ * @param[in] id Priority of the entry. -1 matches all the priorities.
+ * @param[in] fingerprint Fingerprint fo the entry. NULL matches all the fingerprints.
+ * @param[in] map_type Mapping type of the entry. 0 matches all the mapping types.
+ * @param[in] name Specific username for the entry. NULL matches all the usernames.
+ * @return 0 on success, -1 on not finding any match.
+ */
 int nc_tls_server_del_ctn(int64_t id, const char *fingerprint, NC_TLS_CTN_MAPTYPE map_type, const char *name);
 
+/**
+ * @brief Free all the various TLS server options.
+ */
 void nc_tls_server_free_opts(void);
 
 #endif /* ENABLE_TLS */