The libssh callbacks

Collaboration diagram for The libssh callbacks:

Data Structures
struct	ssh_callbacks_struct
struct	ssh_server_callbacks_struct
struct	ssh_socket_callbacks_struct

Macros
#define	ssh_callbacks_init(p)
	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_exists(p, c)
#define	ssh_callbacks_execute_list(list, cbtype, c, ...)
#define	ssh_callbacks_iterate(_cb_list, _cb_type, _cb_name)
#define	ssh_callbacks_iterate_exec(_cb_name, ...)    _cb->_cb_name(__VA_ARGS__, _cb->userdata)
#define	ssh_callbacks_iterate_end()
#define	SSH_PACKET_USED   1
#define	SSH_PACKET_NOT_USED   2
#define	SSH_PACKET_CALLBACK(name)    int name (ssh_session session, uint8_t type, ssh_buffer packet, void *user)
	This macro declares a packet callback handler.

Typedefs
typedef void(*	ssh_log_callback) (ssh_session session, int priority, const char *message, void *userdata)
	SSH log callback. All logging messages will go through this callback.
typedef void(*	ssh_logging_callback) (int priority, const char *function, const char *buffer, void *userdata)
	SSH log callback.
typedef void(*	ssh_status_callback) (ssh_session session, float status, void *userdata)
	SSH Connection status callback.
typedef void(*	ssh_global_request_callback) (ssh_session session, ssh_message message, void *userdata)
	SSH global request callback. All global request will go through this callback.
typedef ssh_channel(*	ssh_channel_open_request_x11_callback) (ssh_session session, const char *originator_address, int originator_port, void *userdata)
	Handles an SSH new channel open X11 request. This happens when the server sends back an X11 connection attempt. This is a client-side API.
typedef ssh_channel(*	ssh_channel_open_request_auth_agent_callback) (ssh_session session, void *userdata)
	Handles an SSH new channel open "auth-agent" request. This happens when the server sends back an "auth-agent" connection attempt. This is a client-side API.
typedef ssh_channel(*	ssh_channel_open_request_forwarded_tcpip_callback) (ssh_session session, const char *destination_address, int destination_port, const char *originator_address, int originator_port, void *userdata)
	Handles an SSH new channel open "forwarded-tcpip" request. This happens when the server forwards an incoming TCP connection on a port it was previously requested to listen on. This is a client-side API.
typedef int(*	ssh_auth_password_callback) (ssh_session session, const char *user, const char *password, void *userdata)
	SSH authentication callback.
typedef int(*	ssh_auth_none_callback) (ssh_session session, const char *user, void *userdata)
	SSH authentication callback. Tries to authenticates user with the "none" method which is anonymous or passwordless.
typedef int(*	ssh_auth_gssapi_mic_callback) (ssh_session session, const char *user, const char *principal, void *userdata)
	SSH authentication callback. Tries to authenticates user with the "gssapi-with-mic" method.
typedef int(*	ssh_auth_pubkey_callback) (ssh_session session, const char *user, struct ssh_key_struct *pubkey, char signature_state, void *userdata)
	SSH authentication callback.
typedef int(*	ssh_service_request_callback) (ssh_session session, const char *service, void *userdata)
	Handles an SSH service request.
typedef ssh_channel(*	ssh_channel_open_request_session_callback) (ssh_session session, void *userdata)
	Handles an SSH new channel open session request.
typedef int(*	ssh_packet_callback) (ssh_session session, uint8_t type, ssh_buffer packet, void *user)
	Prototype for a packet callback, to be called when a new packet arrives.
typedef int(*	ssh_channel_data_callback) (ssh_session session, ssh_channel channel, void *data, uint32_t len, int is_stderr, void *userdata)
	SSH channel data callback. Called when data is available on a channel.
typedef void(*	ssh_channel_eof_callback) (ssh_session session, ssh_channel channel, void *userdata)
	SSH channel eof callback. Called when a channel receives EOF.
typedef void(*	ssh_channel_close_callback) (ssh_session session, ssh_channel channel, void *userdata)
	SSH channel close callback. Called when a channel is closed by remote peer.
typedef void(*	ssh_channel_signal_callback) (ssh_session session, ssh_channel channel, const char *signal, void *userdata)
	SSH channel signal callback. Called when a channel has received a signal.
typedef void(*	ssh_channel_exit_status_callback) (ssh_session session, ssh_channel channel, int exit_status, void *userdata)
	SSH channel exit status callback. Called when a channel has received an exit status.
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)
	SSH channel exit signal callback. Called when a channel has received an exit signal.
typedef int(*	ssh_channel_pty_request_callback) (ssh_session session, ssh_channel channel, const char *term, int width, int height, int pxwidth, int pwheight, void *userdata)
	SSH channel PTY request from a client.
typedef int(*	ssh_channel_shell_request_callback) (ssh_session session, ssh_channel channel, void *userdata)
	SSH channel Shell request from a client.
typedef void(*	ssh_channel_auth_agent_req_callback) (ssh_session session, ssh_channel channel, void *userdata)
	SSH auth-agent-request from the client. This request is sent by a client when agent forwarding is available. Server is free to ignore this callback, no answer is expected.
typedef void(*	ssh_channel_x11_req_callback) (ssh_session session, ssh_channel channel, int single_connection, const char *auth_protocol, const char *auth_cookie, uint32_t screen_number, void *userdata)
	SSH X11 request from the client. This request is sent by a client when X11 forwarding is requested(and available). Server is free to ignore this callback, no answer is expected.
typedef int(*	ssh_channel_pty_window_change_callback) (ssh_session session, ssh_channel channel, int width, int height, int pxwidth, int pwheight, void *userdata)
	SSH channel PTY windows change (terminal size) from a client.
typedef int(*	ssh_channel_exec_request_callback) (ssh_session session, ssh_channel channel, const char *command, void *userdata)
	SSH channel Exec request from a client.
typedef int(*	ssh_channel_env_request_callback) (ssh_session session, ssh_channel channel, const char *env_name, const char *env_value, void *userdata)
	SSH channel environment request from a client.
typedef int(*	ssh_channel_subsystem_request_callback) (ssh_session session, ssh_channel channel, const char *subsystem, void *userdata)
	SSH channel subsystem request from a client.
typedef int(*	ssh_channel_write_wontblock_callback) (ssh_session session, ssh_channel channel, uint32_t bytes, void *userdata)
	SSH channel write will not block (flow control).
typedef void(*	ssh_channel_open_resp_callback) (ssh_session session, ssh_channel channel, bool is_success, void *userdata)
	SSH channel open callback. Called when a channel open succeeds or fails.
typedef void(*	ssh_channel_request_resp_callback) (ssh_session session, ssh_channel channel, void *userdata)
	SSH channel request response callback. Called when a response to the pending request is received.

Functions
LIBSSH_API int	ssh_set_server_callbacks (ssh_session session, ssh_server_callbacks cb)
	Set the session server callback functions.
LIBSSH_API int	ssh_set_callbacks (ssh_session session, ssh_callbacks cb)
	Set the session callback functions.
LIBSSH_API int	ssh_set_channel_callbacks (ssh_channel channel, ssh_channel_callbacks cb)
	Set the channel callback functions.
LIBSSH_API int	ssh_add_channel_callbacks (ssh_channel channel, ssh_channel_callbacks cb)
	Add channel callback functions.
LIBSSH_API int	ssh_remove_channel_callbacks (ssh_channel channel, ssh_channel_callbacks cb)
	Remove a channel callback.

Detailed Description

Callback which can be replaced in libssh.

Macro Definition Documentation

ssh_callbacks_execute_list

#define ssh_callbacks_execute_list	(		list,
			cbtype,
			c,
			... )

Value:

    do {                                                      \
        struct ssh_iterator *i = ssh_list_get_iterator(list); \
        cbtype cb;                                            \
        while (i != NULL){                                    \
            cb = ssh_iterator_value(cbtype, i);               \
            if (ssh_callbacks_exists(cb, c))                  \
                cb-> c (__VA_ARGS__, cb->userdata);           \
            i = i->next;                                      \
        }                                                     \
    } while(0)

ssh_callbacks_exists

#define ssh_callbacks_exists	(		p,
			c )

Value:

  (\
  (p != NULL) && ( (char *)&((p)-> c) < (char *)(p) + (p)->size ) && \
  ((p)-> c != NULL) \
  )

ssh_callbacks_init

#define ssh_callbacks_init

(

p

)

Value:

    do {\
    (p)->size=sizeof(*(p)); \
} while(0);

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.

ssh_callbacks_iterate

#define ssh_callbacks_iterate	(		_cb_list,
			_cb_type,
			_cb_name )

Value:

    do {                                                              \
        struct ssh_iterator *_cb_i = ssh_list_get_iterator(_cb_list); \
        _cb_type _cb;                                                 \
        for (; _cb_i != NULL; _cb_i = _cb_i->next) {                  \
            _cb = ssh_iterator_value(_cb_type, _cb_i);                \
            if (ssh_callbacks_exists(_cb, _cb_name))

ssh_callbacks_iterate_end

#define ssh_callbacks_iterate_end

(

)

Value:

        }                           \
    } while(0)

SSH_PACKET_CALLBACK

#define SSH_PACKET_CALLBACK

(

name

)

int name (ssh_session session, uint8_t type, ssh_buffer packet, void *user)

This macro declares a packet callback handler.

SSH_PACKET_CALLBACK(mycallback){
...
}

SSH_PACKET_NOT_USED

#define SSH_PACKET_NOT_USED   2

Packet was not used and should be passed to any other callback available

SSH_PACKET_USED

#define SSH_PACKET_USED   1

return values for a ssh_packet_callback Packet was used and should not be parsed by another callback

Typedef Documentation

ssh_auth_gssapi_mic_callback

typedef int(* ssh_auth_gssapi_mic_callback) (ssh_session session, const char *user, const char *principal, void *userdata)

SSH authentication callback. Tries to authenticates user with the "gssapi-with-mic" method.

Parameters

session	Current session handler
user	Username of the user (can be spoofed)
principal	Authenticated principal of the user, including realm.
userdata	Userdata to be passed to the callback function.

Returns

SSH_AUTH_SUCCESS Authentication is accepted.

SSH_AUTH_PARTIAL Partial authentication, more authentication means are needed.

SSH_AUTH_DENIED Authentication failed.

Warning

Implementations should verify that parameter user matches in some way the principal. user and principal can be different. Only the latter is guaranteed to be safe.

ssh_auth_none_callback

typedef int(* ssh_auth_none_callback) (ssh_session session, const char *user, void *userdata)

SSH authentication callback. Tries to authenticates user with the "none" method which is anonymous or passwordless.

Parameters

session	Current session handler
user	User that wants to authenticate
userdata	Userdata to be passed to the callback function.

Returns

SSH_AUTH_SUCCESS Authentication is accepted.

SSH_AUTH_PARTIAL Partial authentication, more authentication means are needed.

SSH_AUTH_DENIED Authentication failed.

ssh_auth_password_callback

typedef int(* ssh_auth_password_callback) (ssh_session session, const char *user, const char *password, void *userdata)

SSH authentication callback.

These are callbacks used specifically in SSH servers.

Parameters

session	Current session handler
user	User that wants to authenticate
password	Password used for authentication
userdata	Userdata to be passed to the callback function.

Returns

SSH_AUTH_SUCCESS Authentication is accepted.

SSH_AUTH_PARTIAL Partial authentication, more authentication means are needed.

SSH_AUTH_DENIED Authentication failed.

ssh_auth_pubkey_callback

typedef int(* ssh_auth_pubkey_callback) (ssh_session session, const char *user, struct ssh_key_struct *pubkey, char signature_state, void *userdata)

SSH authentication callback.

Parameters

session	Current session handler
user	User that wants to authenticate
pubkey	public key used for authentication
signature_state	SSH_PUBLICKEY_STATE_NONE if the key is not signed (simple public key probe), SSH_PUBLICKEY_STATE_VALID if the signature is valid. Others values should be replied with a SSH_AUTH_DENIED.
userdata	Userdata to be passed to the callback function.

Returns

SSH_AUTH_SUCCESS Authentication is accepted.

SSH_AUTH_PARTIAL Partial authentication, more authentication means are needed.

SSH_AUTH_DENIED Authentication failed.

ssh_channel_auth_agent_req_callback

typedef void(* ssh_channel_auth_agent_req_callback) (ssh_session session, ssh_channel channel, void *userdata)

SSH auth-agent-request from the client. This request is sent by a client when agent forwarding is available. Server is free to ignore this callback, no answer is expected.

Parameters

session	the session
channel	the channel
userdata	Userdata to be passed to the callback function.

ssh_channel_close_callback

typedef void(* ssh_channel_close_callback) (ssh_session session, ssh_channel channel, void *userdata)

SSH channel close callback. Called when a channel is closed by remote peer.

Parameters

session	Current session handler
channel	the actual channel
userdata	Userdata to be passed to the callback function.

ssh_channel_data_callback

typedef int(* ssh_channel_data_callback) (ssh_session session, ssh_channel channel, void *data, uint32_t len, int is_stderr, void *userdata)

SSH channel data callback. Called when data is available on a channel.

Parameters

session	Current session handler
channel	the actual channel
data	the data that has been read on the channel
len	the length of the data
is_stderr	is 0 for stdout or 1 for stderr
userdata	Userdata to be passed to the callback function.

Returns

number of bytes processed by the callee. The remaining bytes will be sent in the next callback message, when more data is available.

ssh_channel_env_request_callback

typedef int(* ssh_channel_env_request_callback) (ssh_session session, ssh_channel channel, const char *env_name, const char *env_value, void *userdata)

SSH channel environment request from a client.

Parameters

session	the session
channel	the channel
env_name	name of the environment value to be set
env_value	value of the environment value to be set
userdata	Userdata to be passed to the callback function.

Returns

0 if the env request is accepted

1 if the request is denied

Warning

some environment variables can be dangerous if changed (e.g. LD_PRELOAD) and should not be fulfilled.

ssh_channel_eof_callback

typedef void(* ssh_channel_eof_callback) (ssh_session session, ssh_channel channel, void *userdata)

SSH channel eof callback. Called when a channel receives EOF.

Parameters

session	Current session handler
channel	the actual channel
userdata	Userdata to be passed to the callback function.

ssh_channel_exec_request_callback

typedef int(* ssh_channel_exec_request_callback) (ssh_session session, ssh_channel channel, const char *command, void *userdata)

SSH channel Exec request from a client.

Parameters

session	the session
channel	the channel
command	the shell command to be executed
userdata	Userdata to be passed to the callback function.

Returns

0 if the exec request is accepted

1 if the request is denied

ssh_channel_exit_signal_callback

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)

SSH channel exit signal callback. Called when a channel has received an exit signal.

Parameters

session	Current session handler
channel	the actual channel
signal	the signal name (without the SIG prefix)
core	a boolean telling whether a core has been dumped or not
errmsg	the description of the exception
lang	the language of the description (format: RFC 3066)
userdata	Userdata to be passed to the callback function.

ssh_channel_exit_status_callback

typedef void(* ssh_channel_exit_status_callback) (ssh_session session, ssh_channel channel, int exit_status, void *userdata)

SSH channel exit status callback. Called when a channel has received an exit status.

Parameters

session	Current session handler
channel	the actual channel
exit_status	Exit status of the ran command
userdata	Userdata to be passed to the callback function.

ssh_channel_open_request_auth_agent_callback

typedef ssh_channel(* ssh_channel_open_request_auth_agent_callback) (ssh_session session, void *userdata)

Handles an SSH new channel open "auth-agent" request. This happens when the server sends back an "auth-agent" connection attempt. This is a client-side API.

Parameters

session	current session handler
userdata	Userdata to be passed to the callback function.

Returns

a valid ssh_channel handle if the request is to be allowed

NULL if the request should not be allowed

Warning

The channel pointer returned by this callback must be closed by the application.

ssh_channel_open_request_forwarded_tcpip_callback

typedef ssh_channel(* ssh_channel_open_request_forwarded_tcpip_callback) (ssh_session session, const char *destination_address, int destination_port, const char *originator_address, int originator_port, void *userdata)

Handles an SSH new channel open "forwarded-tcpip" request. This happens when the server forwards an incoming TCP connection on a port it was previously requested to listen on. This is a client-side API.

Parameters

session	current session handler
destination_address	the address that the TCP connection connected to
destination_port	the port that the TCP connection connected to
originator_address	the originator IP address
originator_port	the originator port
userdata	Userdata to be passed to the callback function.

Returns

a valid ssh_channel handle if the request is to be allowed

NULL if the request should not be allowed

Warning

The channel pointer returned by this callback must be closed by the application.

ssh_channel_open_request_session_callback

typedef ssh_channel(* ssh_channel_open_request_session_callback) (ssh_session session, void *userdata)

Handles an SSH new channel open session request.

Parameters

session	current session handler
userdata	Userdata to be passed to the callback function.

Returns

a valid ssh_channel handle if the request is to be allowed

NULL if the request should not be allowed

Warning

The channel pointer returned by this callback must be closed by the application.

ssh_channel_open_request_x11_callback

typedef ssh_channel(* ssh_channel_open_request_x11_callback) (ssh_session session, const char *originator_address, int originator_port, void *userdata)

Handles an SSH new channel open X11 request. This happens when the server sends back an X11 connection attempt. This is a client-side API.

Parameters

session	current session handler
userdata	Userdata to be passed to the callback function.
originator_address	IP address of the machine who sent the request
originator_port	port number of the machine who sent the request

Returns

a valid ssh_channel handle if the request is to be allowed

NULL if the request should not be allowed

Warning

The channel pointer returned by this callback must be closed by the application.

ssh_channel_open_resp_callback

typedef void(* ssh_channel_open_resp_callback) (ssh_session session, ssh_channel channel, bool is_success, void *userdata)

SSH channel open callback. Called when a channel open succeeds or fails.

Parameters

session	Current session handler
channel	the actual channel
is_success	is 1 when the open succeeds, and 0 otherwise.
userdata	Userdata to be passed to the callback function.

ssh_channel_pty_request_callback

typedef int(* ssh_channel_pty_request_callback) (ssh_session session, ssh_channel channel, const char *term, int width, int height, int pxwidth, int pwheight, void *userdata)

SSH channel PTY request from a client.

Parameters

session	the session
channel	the channel
term	The type of terminal emulation
width	width of the terminal, in characters
height	height of the terminal, in characters
pxwidth	width of the terminal, in pixels
pwheight	height of the terminal, in pixels
userdata	Userdata to be passed to the callback function.

Returns

0 if the pty request is accepted

-1 if the request is denied

ssh_channel_pty_window_change_callback

typedef int(* ssh_channel_pty_window_change_callback) (ssh_session session, ssh_channel channel, int width, int height, int pxwidth, int pwheight, void *userdata)

SSH channel PTY windows change (terminal size) from a client.

Parameters

session	the session
channel	the channel
width	width of the terminal, in characters
height	height of the terminal, in characters
pxwidth	width of the terminal, in pixels
pwheight	height of the terminal, in pixels
userdata	Userdata to be passed to the callback function.

Returns

0 if the pty request is accepted

-1 if the request is denied

ssh_channel_request_resp_callback

typedef void(* ssh_channel_request_resp_callback) (ssh_session session, ssh_channel channel, void *userdata)

SSH channel request response callback. Called when a response to the pending request is received.

Parameters

session	Current session handler
channel	the actual channel
userdata	Userdata to be passed to the callback function.

ssh_channel_shell_request_callback

typedef int(* ssh_channel_shell_request_callback) (ssh_session session, ssh_channel channel, void *userdata)

SSH channel Shell request from a client.

Parameters

session	the session
channel	the channel
userdata	Userdata to be passed to the callback function.

Returns

0 if the shell request is accepted

1 if the request is denied

ssh_channel_signal_callback

typedef void(* ssh_channel_signal_callback) (ssh_session session, ssh_channel channel, const char *signal, void *userdata)

SSH channel signal callback. Called when a channel has received a signal.

Parameters

session	Current session handler
channel	the actual channel
signal	the signal name (without the SIG prefix)
userdata	Userdata to be passed to the callback function.

ssh_channel_subsystem_request_callback

typedef int(* ssh_channel_subsystem_request_callback) (ssh_session session, ssh_channel channel, const char *subsystem, void *userdata)

SSH channel subsystem request from a client.

Parameters

session	the session
channel	the channel
subsystem	the subsystem required
userdata	Userdata to be passed to the callback function.

Returns

0 if the subsystem request is accepted

1 if the request is denied

ssh_channel_write_wontblock_callback

typedef int(* ssh_channel_write_wontblock_callback) (ssh_session session, ssh_channel channel, uint32_t bytes, void *userdata)

SSH channel write will not block (flow control).

Parameters

	session	the session
	channel	the channel
[in]	bytes	size of the remote window in bytes. Writing as much data will not block.
[in]	userdata	Userdata to be passed to the callback function.

Returns

0 default return value (other return codes may be added in future).

ssh_channel_x11_req_callback

typedef void(* ssh_channel_x11_req_callback) (ssh_session session, ssh_channel channel, int single_connection, const char *auth_protocol, const char *auth_cookie, uint32_t screen_number, void *userdata)

SSH X11 request from the client. This request is sent by a client when X11 forwarding is requested(and available). Server is free to ignore this callback, no answer is expected.

Parameters

session	the session
channel	the channel
single_connection	If true, only one channel should be forwarded
auth_protocol	The X11 authentication method to be used
auth_cookie	Authentication cookie encoded hexadecimal
screen_number	Screen number
userdata	Userdata to be passed to the callback function.

ssh_global_request_callback

typedef void(* ssh_global_request_callback) (ssh_session session, ssh_message message, void *userdata)

SSH global request callback. All global request will go through this callback.

Parameters

session	Current session handler
message	the actual message
userdata	Userdata to be passed to the callback function.

ssh_log_callback

typedef void(* ssh_log_callback) (ssh_session session, int priority, const char *message, void *userdata)

SSH log callback. All logging messages will go through this callback.

Parameters

session	Current session handler
priority	Priority of the log, the smaller being the more important
message	the actual message
userdata	Userdata to be passed to the callback function.

ssh_logging_callback

typedef void(* ssh_logging_callback) (int priority, const char *function, const char *buffer, void *userdata)

SSH log callback.

All logging messages will go through this callback.

Parameters

priority	Priority of the log, the smaller being the more important.
function	The function name calling the logging functions.
buffer	The actual message
userdata	Userdata to be passed to the callback function.

ssh_packet_callback

typedef int(* ssh_packet_callback) (ssh_session session, uint8_t type, ssh_buffer packet, void *user)

Prototype for a packet callback, to be called when a new packet arrives.

Parameters

session	The current session of the packet
type	packet type (see ssh2.h)
packet	buffer containing the packet, excluding size, type and padding fields
user	user argument to the callback and are called each time a packet shows up

Returns

SSH_PACKET_USED Packet was parsed and used

SSH_PACKET_NOT_USED Packet was not used or understood, processing must continue

ssh_service_request_callback

typedef int(* ssh_service_request_callback) (ssh_session session, const char *service, void *userdata)

Handles an SSH service request.

Parameters

session	current session handler
service	name of the service (e.g. "ssh-userauth") requested
userdata	Userdata to be passed to the callback function.

Returns

0 if the request is to be allowed

-1 if the request should not be allowed

ssh_status_callback

typedef void(* ssh_status_callback) (ssh_session session, float status, void *userdata)

SSH Connection status callback.

Parameters

session	Current session handler
status	Percentage of connection status, going from 0.0 to 1.0 once connection is done.
userdata	Userdata to be passed to the callback function.

Function Documentation

ssh_add_channel_callbacks()

LIBSSH_API int ssh_add_channel_callbacks	(	ssh_channel	channel,
		ssh_channel_callbacks	cb )

Add channel callback functions.

This function will add channel callback functions to the channel callback list. Callbacks missing from a callback structure will be probed in the next on the list.

Parameters

channel	The channel to set the callback structure.
cb	The callback structure itself.

Returns

SSH_OK on success, SSH_ERROR on error.

See also

ssh_set_channel_callbacks

ssh_remove_channel_callbacks()

LIBSSH_API int ssh_remove_channel_callbacks	(	ssh_channel	channel,
		ssh_channel_callbacks	cb )

Remove a channel callback.

The channel has been added with ssh_add_channel_callbacks or ssh_set_channel_callbacks in this case.

Parameters

channel	The channel to remove the callback structure from.
cb	The callback structure to remove

Returns

SSH_OK on success, SSH_ERROR on error.

ssh_set_callbacks()

LIBSSH_API int ssh_set_callbacks	(	ssh_session	session,
		ssh_callbacks	cb )

Set the session callback functions.

This functions sets the callback structure to use your own callback functions for auth, logging and status.

Note, that the callback structure is not copied into the session so it needs to be valid for the whole session lifetime.

struct ssh_callbacks_struct cb = {
  .userdata = data,
  .auth_function = my_auth_function
};
ssh_callbacks_init(&cb);
ssh_set_callbacks(session, &cb);

Parameters

session	The session to set the callback structure.
cb	The callback structure itself.

Returns

SSH_OK on success, SSH_ERROR on error.

ssh_set_channel_callbacks()

LIBSSH_API int ssh_set_channel_callbacks	(	ssh_channel	channel,
		ssh_channel_callbacks	cb )

Set the channel callback functions.

This functions sets the callback structure to use your own callback functions for channel data and exceptions.

Note, that the structure is not copied to the channel structure so it needs to be valid as for the whole life of the channel or until it is removed with ssh_remove_channel_callbacks().

struct ssh_channel_callbacks_struct cb = {
  .userdata = data,
  .channel_data_function = my_channel_data_function
};
ssh_callbacks_init(&cb);
ssh_set_channel_callbacks(channel, &cb);

Parameters

channel	The channel to set the callback structure.
cb	The callback structure itself.

Returns

SSH_OK on success, SSH_ERROR on error.

Warning

this function will not replace existing callbacks but set the new one atop of them.

ssh_set_server_callbacks()

LIBSSH_API int ssh_set_server_callbacks	(	ssh_session	session,
		ssh_server_callbacks	cb )

Set the session server callback functions.

This functions sets the callback structure to use your own callback functions for user authentication, new channels and requests.

Note, that the structure is not copied to the session structure so it needs to be valid for the whole session lifetime.

struct ssh_server_callbacks_struct cb = {
  .userdata = data,
  .auth_password_function = my_auth_function
};
ssh_callbacks_init(&cb);
ssh_set_server_callbacks(session, &cb);

Parameters

session	The session to set the callback structure.
cb	The callback structure itself.

Returns

SSH_OK on success, SSH_ERROR on error.