/* * This file is part of the SSH Library * * Copyright (c) 2009 Aris Adamantiadis * * The SSH Library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or (at your * option) any later version. * * The SSH Library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with the SSH Library; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, * MA 02111-1307, USA. */ /* callback.h * This file includes the public declarations for the libssh callback mechanism */ #ifndef _SSH_CALLBACK_H #define _SSH_CALLBACK_H #include #include #ifdef __cplusplus extern "C" { #endif /** * @defgroup libssh_callbacks The libssh callbacks * @ingroup libssh * * Callback which can be replaced in libssh. * * @{ */ /** @internal * @brief callback to process simple codes * @param code value to transmit * @param user Userdata to pass in callback */ typedef void (*ssh_callback_int) (int code, void *user); /** @internal * @brief callback for data received messages. * @param data data retrieved from the socket or stream * @param len number of bytes available from this stream * @param user user-supplied pointer sent along with all callback messages * @returns number of bytes processed by the callee. The remaining bytes will * be sent in the next callback message, when more data is available. */ typedef int (*ssh_callback_data) (const void *data, size_t len, void *user); typedef void (*ssh_callback_int_int) (int code, int errno_code, void *user); typedef int (*ssh_message_callback) (ssh_session, ssh_message message, void *user); typedef int (*ssh_channel_callback_int) (ssh_channel channel, int code, void *user); typedef int (*ssh_channel_callback_data) (ssh_channel channel, int code, void *data, size_t len, void *user); /** * @brief SSH log callback. All logging messages will go through this callback * @param session Current session handler * @param priority Priority of the log, the smaller being the more important * @param message the actual message * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_log_callback) (ssh_session session, int priority, const char *message, void *userdata); /** * @brief SSH Connection status callback. * @param session Current session handler * @param status Percentage of connection status, going from 0.0 to 1.0 * once connection is done. * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_status_callback) (ssh_session session, float status, void *userdata); /** * @brief SSH global request callback. All global request will go through this * callback. * @param session Current session handler * @param message the actual message * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_global_request_callback) (ssh_session session, ssh_message message, void *userdata); /** * The structure to replace libssh functions with appropriate callbacks. */ struct ssh_callbacks_struct { /** DON'T SET THIS use ssh_callbacks_init() instead. */ size_t size; /** * User-provided data. User is free to set anything he wants here */ void *userdata; /** * This functions will be called if e.g. a keyphrase is needed. */ ssh_auth_callback auth_function; /** * This function will be called each time a loggable event happens. */ ssh_log_callback log_function; /** * This function gets called during connection time to indicate the * percentage of connection steps completed. */ void (*connect_status_function)(void *userdata, float status); /** * This function will be called each time a global request is received. */ ssh_global_request_callback global_request_function; }; typedef struct ssh_callbacks_struct *ssh_callbacks; /** * These are the callbacks exported by the socket structure * They are called by the socket module when a socket event appears */ struct ssh_socket_callbacks_struct { /** * User-provided data. User is free to set anything he wants here */ void *userdata; /** * This function will be called each time data appears on socket. The data * not consumed will appear on the next data event. */ ssh_callback_data data; /** This function will be called each time a controlflow state changes, i.e. * the socket is available for reading or writing. */ ssh_callback_int controlflow; /** This function will be called each time an exception appears on socket. An * exception can be a socket problem (timeout, ...) or an end-of-file. */ ssh_callback_int_int exception; /** This function is called when the ssh_socket_connect was used on the socket * on nonblocking state, and the connection successed. */ ssh_callback_int_int connected; }; typedef struct ssh_socket_callbacks_struct *ssh_socket_callbacks; #define SSH_SOCKET_FLOW_WRITEWILLBLOCK 1 #define SSH_SOCKET_FLOW_WRITEWONTBLOCK 2 #define SSH_SOCKET_EXCEPTION_EOF 1 #define SSH_SOCKET_EXCEPTION_ERROR 2 #define SSH_SOCKET_CONNECTED_OK 1 #define SSH_SOCKET_CONNECTED_ERROR 2 #define SSH_SOCKET_CONNECTED_TIMEOUT 3 /** * @brief Initializes an ssh_callbacks_struct * A call to this macro is mandatory when you have set a new * ssh_callback_struct structure. Its goal is to maintain the binary * compatibility with future versions of libssh as the structure * evolves with time. */ #define ssh_callbacks_init(p) do {\ (p)->size=sizeof(*(p)); \ } while(0); /** * @internal * @brief tests if a callback can be called without crash * verifies that the struct size if big enough * verifies that the callback pointer exists * @param p callback pointer * @param c callback name * @returns nonzero if callback can be called */ #define ssh_callbacks_exists(p,c) (\ (p != NULL) && ( (char *)&((p)-> c) < (char *)(p) + (p)->size ) && \ ((p)-> c != NULL) \ ) /** @brief Prototype for a packet callback, to be called when a new packet arrives * @param session The current session of the packet * @param type packet type (see ssh2.h) * @param packet buffer containing the packet, excluding size, type and padding fields * @param user user argument to the callback * and are called each time a packet shows up * @returns SSH_PACKET_USED Packet was parsed and used * @returns SSH_PACKET_NOT_USED Packet was not used or understood, processing must continue */ typedef int (*ssh_packet_callback) (ssh_session session, uint8_t type, ssh_buffer packet, void *user); /** return values for a ssh_packet_callback */ /** Packet was used and should not be parsed by another callback */ #define SSH_PACKET_USED 1 /** Packet was not used and should be passed to any other callback * available */ #define SSH_PACKET_NOT_USED 2 /** @brief This macro declares a packet callback handler * @code * SSH_PACKET_CALLBACK(mycallback){ * ... * } * @endcode */ #define SSH_PACKET_CALLBACK(name) \ int name (ssh_session session, uint8_t type, ssh_buffer packet, void *user) struct ssh_packet_callbacks_struct { /** Index of the first packet type being handled */ uint8_t start; /** Number of packets being handled by this callback struct */ uint8_t n_callbacks; /** A pointer to n_callbacks packet callbacks */ ssh_packet_callback *callbacks; /** * User-provided data. User is free to set anything he wants here */ void *user; }; typedef struct ssh_packet_callbacks_struct *ssh_packet_callbacks; /** * @brief Set the session callback functions. * * This functions sets the callback structure to use your own callback * functions for auth, logging and status. * * @code * struct ssh_callbacks_struct cb = { * .userdata = data, * .auth_function = my_auth_function * }; * ssh_callbacks_init(&cb); * ssh_set_callbacks(session, &cb); * @endcode * * @param session The session to set the callback structure. * * @param cb The callback structure itself. * * @return SSH_OK on success, SSH_ERROR on error. */ LIBSSH_API int ssh_set_callbacks(ssh_session session, ssh_callbacks cb); /** * @brief SSH channel data callback. Called when data is available on a channel * @param session Current session handler * @param channel the actual channel * @param data the data that has been read on the channel * @param len the length of the data * @param is_stderr is 0 for stdout or 1 for stderr * @param userdata Userdata to be passed to the callback function. */ typedef int (*ssh_channel_data_callback) (ssh_session session, ssh_channel channel, void *data, uint32_t len, int is_stderr, void *userdata); /** * @brief SSH channel eof callback. Called when a channel receives EOF * @param session Current session handler * @param channel the actual channel * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_channel_eof_callback) (ssh_session session, ssh_channel channel, void *userdata); /** * @brief SSH channel close callback. Called when a channel is closed by remote peer * @param session Current session handler * @param channel the actual channel * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_channel_close_callback) (ssh_session session, ssh_channel channel, void *userdata); /** * @brief SSH channel signal callback. Called when a channel has received a signal * @param session Current session handler * @param channel the actual channel * @param signal the signal name (without the SIG prefix) * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_channel_signal_callback) (ssh_session session, ssh_channel channel, const char *signal, void *userdata); /** * @brief SSH channel exit status callback. Called when a channel has received an exit status * @param session Current session handler * @param channel the actual channel * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_channel_exit_status_callback) (ssh_session session, ssh_channel channel, int exit_status, void *userdata); /** * @brief SSH channel exit signal callback. Called when a channel has received an exit signal * @param session Current session handler * @param channel the actual channel * @param signal the signal name (without the SIG prefix) * @param core a boolean telling wether a core has been dumped or not * @param errmsg the description of the exception * @param lang the language of the description (format: RFC 3066) * @param userdata Userdata to be passed to the callback function. */ typedef void (*ssh_channel_exit_signal_callback) (ssh_session session, ssh_channel channel, const char *signal, int core, const char *errmsg, const char *lang, void *userdata); struct ssh_channel_callbacks_struct { /** DON'T SET THIS use ssh_callbacks_init() instead. */ size_t size; /** * User-provided data. User is free to set anything he wants here */ void *userdata; /** * This functions will be called when there is data available. */ ssh_channel_data_callback channel_data_function; /** * This functions will be called when the channel has received an EOF. */ ssh_channel_eof_callback channel_eof_function; /** * This functions will be called when the channel has been closed by remote */ ssh_channel_close_callback channel_close_function; /** * This functions will be called when a signal has been received */ ssh_channel_signal_callback channel_signal_function; /** * This functions will be called when an exit status has been received */ ssh_channel_exit_status_callback channel_exit_status_function; /** * This functions will be called when an exit signal has been received */ ssh_channel_exit_signal_callback channel_exit_signal_function; }; typedef struct ssh_channel_callbacks_struct *ssh_channel_callbacks; /** * @brief Set the channel callback functions. * * This functions sets the callback structure to use your own callback * functions for channel data and exceptions * * @code * struct ssh_channel_callbacks_struct cb = { * .userdata = data, * .channel_data = my_channel_data_function * }; * ssh_callbacks_init(&cb); * ssh_set_channel_callbacks(channel, &cb); * @endcode * * @param channel The channel to set the callback structure. * * @param cb The callback structure itself. * * @return SSH_OK on success, SSH_ERROR on error. */ LIBSSH_API int ssh_set_channel_callbacks(ssh_channel channel, ssh_channel_callbacks cb); /** @} */ /** @group libssh_threads * @{ */ typedef int (*ssh_thread_callback) (void **lock); typedef unsigned long (*ssh_thread_id_callback) (void); struct ssh_threads_callbacks_struct { const char *type; ssh_thread_callback mutex_init; ssh_thread_callback mutex_destroy; ssh_thread_callback mutex_lock; ssh_thread_callback mutex_unlock; ssh_thread_id_callback thread_id; }; /** * @brief sets the thread callbacks necessary if your program is using * libssh in a multithreaded fashion. This function must be called first, * outside of any threading context (in your main() for instance), before * ssh_init(). * @param cb pointer to a ssh_threads_callbacks_struct structure, which contains * the different callbacks to be set. * @see ssh_threads_callbacks_struct * @see SSH_THREADS_PTHREAD */ LIBSSH_API int ssh_threads_set_callbacks(struct ssh_threads_callbacks_struct *cb); /** * @brief returns a pointer on the pthread threads callbacks, to be used with * ssh_threads_set_callbacks. * @warning you have to link with the library ssh_threads. * @see ssh_threads_set_callbacks */ LIBSSH_API struct ssh_threads_callbacks_struct *ssh_threads_get_pthread(void); /** * @brief returns a pointer on the noop threads callbacks, to be used with * ssh_threads_set_callbacks. These callbacks do nothing and are being used by * default. * @see ssh_threads_set_callbacks */ LIBSSH_API struct ssh_threads_callbacks_struct *ssh_threads_get_noop(void); /** @} */ #ifdef __cplusplus } #endif #endif /*_SSH_CALLBACK_H */ /* @} */