From e7abd910a9cd94677bbcb19cdf5a2bdc2cb83279 Mon Sep 17 00:00:00 2001 From: Hans Nilsson Date: Wed, 7 Aug 2019 17:17:54 +0200 Subject: ssh: The ssh_connection documentation is now generated --- lib/ssh/doc/src/ssh_connection.xml | 411 +++++++++++++++++++------------------ lib/ssh/src/ssh_connection.erl | 160 ++++++++++++--- 2 files changed, 345 insertions(+), 226 deletions(-) diff --git a/lib/ssh/doc/src/ssh_connection.xml b/lib/ssh/doc/src/ssh_connection.xml index 2a701929f6..ea41ccf252 100644 --- a/lib/ssh/doc/src/ssh_connection.xml +++ b/lib/ssh/doc/src/ssh_connection.xml @@ -40,105 +40,148 @@

The SSH Connection Protocol is used by clients and servers, that is, SSH channels, to communicate over the SSH connection. The API functions in this module send SSH Connection Protocol events, - which are received as messages by the remote channel. - If the receiving channel is an Erlang process, the - messages have the format - . + which are received as messages by the remote channel handling the remote channel. + The Erlang format of thoose messages is + (see also below): +

+

{ssh_cm, ssh:connection_ref(), ssh_event_msg()} +

+

If the ssh_client_channel behavior is used to implement the channel process, these messages are handled by handle_ssh_msg/2.

-
- DATA TYPES - -

Type definitions that are used more than once in this module, - or abstractions to indicate the intended use of the data - type, or both:

- - - boolean() = -

true | false

- string() = -

list of ASCII characters

 - timeout() = -

infinity | integer() in milliseconds

 - connection_ref() = -

opaque() -as returned by - ssh:connect/3 or sent to an SSH channel processes

 - channel_id() = -

integer()

 - ssh_data_type_code() = -

1 ("stderr") | 0 ("normal") are - valid values, see - RFC 4254 Section 5.2.

 - ssh_request_status() = -

success | failure

 - event() = -

{ssh_cm, connection_ref(), ssh_event_msg()}

 - ssh_event_msg() = -

data_events() | status_events() | terminal_events()

 - reason() = -

timeout | closed

 - - - - data_events() - - - -

Data has arrived on the channel. This event is sent as a - result of calling - ssh_connection:send/[3,4,5].

 - - -

Indicates that the other side sends no more data. - This event is sent as a result of calling ssh_connection:send_eof/2. -

- - + + + + +

The valid values are 0 ("normal") and 1 ("stderr"), see + RFC 4254, Section 5.2.

+ + + + + + + +

The result of a call.

+

If the request reached the peer, was handled and the response + reached the requesting node the req_status() + is the status reported from the peer.

+

If not, the reason() indicates what went wrong:

+ + closed + indicates that the channel or connection was closed when trying to send the request + + timeout + indicates that the operation exceeded a time limit + + + + + + + + +

The status of a request. + Coresponds to the SSH_MSG_CHANNEL_SUCCESS and SSH_MSG_CHANNEL_FAILURE values in + RFC 4254, Section 5.4. +

+ + + + SSH Connection Protocol: General + + + + +

As mentioned in the introduction, the + SSH Connection Protocol + events are handled as messages. When writing a channel handling process without using + the support by the ssh_client_channel + behavior the process must handle thoose messages. +

+ + - status_events() - + SSH Connection Protocol: Data Events + + + + + + + + + +

Data has arrived on the channel. This event is sent as a result of calling + ssh_connection:send/[3,4,5]. +

+ + + + + +

Indicates that the other side sends no more data. This event is sent as a result of calling + ssh_connection:send_eof/2. +

+ + + + SSH Connection Protocol: Status Events + + + + + - - -

A signal can be delivered to the remote process/service + + + +

A signal can be delivered to the remote process/service using the following message. Some systems do not support signals, in which case they are to ignore this message. There is currently no function to generate this event as the signals referred to are on OS-level and not something generated by an - Erlang program.

 - - + Erlang program.

+ + -

A remote execution can terminate violently because of a signal. + + + +

A remote execution can terminate violently because of a signal. Then this message can be received. For details on valid string values, see RFC 4254 - Section 6.10, which shows a special case of these signals.

 - - -

When the command running at the other end terminates, the + Section 6.10, which shows a special case of these signals.

+ + + + + +

When the command running at the other end terminates, the following message can be sent to return the exit status of the command. A zero exit_status usually means that the command terminated successfully. This event is sent as a result of calling - ssh_connection:exit_status/3.

 - - -

This event is sent as a result of calling + ssh_connection:exit_status/3.

+ + + + + +

This event is sent as a result of calling ssh_connection:close/2. Both the handling of this event and sending it are taken care of by the - ssh_client_channel behavior.

 - - - - - terminal_events() + ssh_client_channel behavior.

+ + - + SSH Connection Protocol: Terminal Events + + +

Channels implementing a shell and command execution on the server side are to handle the following messages that can be sent by client- channel processes.

@@ -146,22 +189,24 @@

Events that include a WantReply expect the event handling process to call ssh_connection:reply_request/4 - with the boolean value of WantReply as the second argument.

+ with the boolean value of WantReply as the second argument.

+ + - - -

Environment variables can be passed to the shell/command + + + +

Environment variables can be passed to the shell/command to be started later. This event is sent as a result of calling ssh_connection:setenv/5. -

- - -

A pseudo-terminal has been requested for the +

+ + + + + + +

A pseudo-terminal has been requested for the session. Terminal is the value of the TERM environment variable value, that is, vt100. Zero dimension parameters must be ignored. The character/row dimensions override the pixel @@ -173,42 +218,48 @@ It can also be an Opcode if the mnemonic name is not listed in the RFC. Example: OP code: 53, mnemonic name ECHO erlang atom: echo. This event is sent as a result of calling ssh_connection:ptty_alloc/4.

 + marker="ssh_connection#ptty_alloc/4">ssh_connection:ptty_alloc/4.

+ + - -

This message requests that the user default shell + + + +

This message requests that the user default shell is started at the other end. This event is sent as a result of calling ssh_connection:shell/2. -

+

+ + - -

When the window (terminal) size changes on the client + + + +

When the window (terminal) size changes on the client side, it can send a message to the server side to inform it of - the new dimensions. No API function generates this event.

 + the new dimensions. No API function generates this event.

+ + - -

This message requests that the server starts + + + +

This message requests that the server starts execution of the given command. This event is sent as a result of calling ssh_connection:exec/4 . -

- - - -
+

+ + + + + - adjust_window(ConnectionRef, ChannelId, NumOfBytes) -> ok + Adjusts the SSH flow control window. - - ConnectionRef = connection_ref() - ChannelId = channel_id() - NumOfBytes = integer() - - +

Adjusts the SSH flow control window. This is to be done by both the client- and server-side channel processes.

@@ -221,17 +272,12 @@ - close(ConnectionRef, ChannelId) -> ok + Sends a close message on the channel ChannelId. - - ConnectionRef = connection_ref() - ChannelId = channel_id() -

A server- or client-channel process can choose to close their session by sending a close event.

-

This function is called by the ssh_client_channel behavior when the channel is terminated, see ssh_client_channel(3). Thus, channels implemented @@ -240,57 +286,61 @@ - exec(ConnectionRef, ChannelId, Command, TimeOut) -> ssh_request_status() | - {error, reason()} + Requests that the server starts the execution of the given command. - - ConnectionRef = connection_ref() - ChannelId = channel_id() - Command = string() - Timeout = timeout() -

Is to be called by a client-channel process to request that the server starts executing the given command. The result is several messages according to the following pattern. The last message is a channel close message, as the exec request is a one-time execution that closes the channel when it is done.

- - N x {ssh_cm, connection_ref(), - {data, channel_id(), ssh_data_type_code(), Data :: binary()}} + + + + N x data message(s) +

The result of executing the command can be only one line + or thousands of lines depending on the command.

 + + 0 or 1 x eof message +

Indicates that no more data is to be sent.

 + + 0 or 1 x exit signal message +

Not all systems send signals. For details on valid string + values, see RFC 4254, Section 6.10

 + + 0 or 1 x exit status message +

It is recommended by the SSH Connection Protocol to send this + message, but that is not always the case.

 + + 1 x closed status message +

Indicates that the ssh_client_channel started for the + execution of the command has now been shut down.

 - exit_status(ConnectionRef, ChannelId, Status) -> ok + Sends the exit status of a command to the client. - - ConnectionRef = connection_ref() - ChannelId = channel_id() - Status = integer() -

Is to be called by a server-channel process to send the exit status of a command to the client.

@@ -298,16 +348,10 @@ - ptty_alloc(ConnectionRef, ChannelId, Options) -> - ptty_alloc(ConnectionRef, ChannelId, Options, Timeout) -> > ssh_request_status() | - {error, reason()} + + Sends an SSH Connection Protocol pty_req, to allocate a pseudo-terminal. - - ConnectionRef = connection_ref() - ChannelId = channel_id() - Options = proplists:proplist() -

Sends an SSH Connection Protocol pty_req, to allocate a pseudo-terminal. Is to be called by an SSH client process.

@@ -339,14 +383,8 @@ - reply_request(ConnectionRef, WantReply, Status, ChannelId) -> ok + Sends status replies to requests that want such replies. - - ConnectionRef = connection_ref() - WantReply = boolean() - Status = ssh_request_status() - ChannelId = channel_id() -

Sends status replies to requests where the requester has stated that it wants a status report, that is, WantReply = true. @@ -361,14 +399,15 @@ send(ConnectionRef, ChannelId, Data, Timeout) -> send(ConnectionRef, ChannelId, Type, Data) -> send(ConnectionRef, ChannelId, Type, Data, TimeOut) -> - ok | {error, timeout} | {error, closed} + ok | Error Sends channel data. - ConnectionRef = connection_ref() - ChannelId = channel_id() + ConnectionRef = ssh:connection_ref() + ChannelId = ssh:channel_id() Data = binary() - Type = ssh_data_type_code() + Type = ssh_data_type_code() Timeout = timeout() + Error = {error, reason()}

Is to be called by client- and server-channel processes to send data to each other. @@ -380,29 +419,17 @@ - send_eof(ConnectionRef, ChannelId) -> ok | {error, closed} + Sends EOF on channel ChannelId. - - ConnectionRef = connection_ref() - ChannelId = channel_id() -

Sends EOF on channel ChannelId.

 - session_channel(ConnectionRef, Timeout) -> - session_channel(ConnectionRef, InitialWindowSize, - MaxPacketSize, Timeout) -> {ok, channel_id()} | {error, reason()} + + Opens a channel for an SSH session. - - ConnectionRef = connection_ref() - InitialWindowSize = integer() - MaxPacketSize = integer() - Timeout = timeout() - Reason = term() -

Opens a channel for an SSH session. The channel id returned from this function is the id used as input to the other functions in this module.

@@ -410,17 +437,9 @@ - setenv(ConnectionRef, ChannelId, Var, Value, TimeOut) -> ssh_request_status() | - {error, reason()} + Environment variables can be passed to the shell/command to be started later. - - ConnectionRef = connection_ref() - ChannelId = channel_id() - Var = string() - Value = string() - Timeout = timeout() -

Environment variables can be passed before starting the shell/command. Is to be called by a client channel processes.

@@ -428,14 +447,9 @@ - shell(ConnectionRef, ChannelId) -> ok | failure | {error, closed} - + Requests that the user default shell (typically defined in /etc/passwd in Unix systems) is to be executed at the server end. - - ConnectionRef = connection_ref() - ChannelId = channel_id() -

Is to be called by a client channel process to request that the user default shell (typically defined in /etc/passwd in Unix systems) is executed @@ -448,15 +462,8 @@ - subsystem(ConnectionRef, ChannelId, Subsystem, Timeout) -> ssh_request_status() | - {error, reason()} + Requests to execute a predefined subsystem on the server. - - ConnectionRef = connection_ref() - ChannelId = channel_id() - Subsystem = string() - Timeout = timeout() -

Is to be called by a client-channel process for requesting to execute a predefined subsystem on the server. diff --git a/lib/ssh/src/ssh_connection.erl b/lib/ssh/src/ssh_connection.erl index 83f85b1d8e..1e54be2a16 100644 --- a/lib/ssh/src/ssh_connection.erl +++ b/lib/ssh/src/ssh_connection.erl @@ -67,6 +67,79 @@ -type connection_ref() :: ssh:connection_ref(). -type channel_id() :: ssh:channel_id(). +-type req_status() :: success | failure . +-type reason() :: closed | timeout . + +-type result() :: req_status() | {error, reason()} . + +-type ssh_data_type_code() :: non_neg_integer(). % Only 0 and 1 are used + + +%%% The SSH Connection Protocol + +-export_type([event/0, + ssh_event_msg/0, + data_event/0, + data_data_event/0, + data_eof_event/0, + status_event/0, + status_signal_event/0, + status_exit_signal_event/0, + status_exit_status_event/0, + status_closed_event/0, + terminal_event/0, + terminal_env_event/0, + terminal_pty_event/0, + terminal_shell_event/0, + terminal_window_change_event/0, + terminal_exec_event/0 + ]). + +-type event() :: {ssh_cm, ssh:connection_ref(), ssh_event_msg()}. +-type ssh_event_msg() :: data_event() | status_event() | terminal_event() . + +-type data_event() :: data_data_event() + | data_eof_event() . +-type data_data_event() :: {data, ssh:channel_id(), ssh_data_type_code(), Data :: binary()} . +-type data_eof_event() :: {eof, ssh:channel_id()} . + + +-type status_event() :: status_signal_event() + | status_exit_signal_event() + | status_exit_status_event() + | status_closed_event() . + +-type status_signal_event() :: {signal, ssh:channel_id(), SignalName::string()} . +-type status_exit_signal_event() :: {exit_signal, ssh:channel_id(), + ExitSignal :: string(), + ErrorMsg ::string(), + LanguageString :: string()} . +-type status_exit_status_event() :: {exit_status, ssh:channel_id(), ExitStatus :: integer()} . +-type status_closed_event() :: {closed, ssh:channel_id()} . + +-type terminal_event() :: terminal_env_event() + | terminal_pty_event() + | terminal_shell_event() + | terminal_window_change_event() + | terminal_exec_event() . + +-type terminal_env_event() :: {env, ssh:channel_id(), WantReply :: boolean(), Var ::string(), Value :: string()} . +-type terminal_pty_event() :: {pty, ssh:channel_id(), + WantReply :: boolean(), + {Terminal :: string(), CharWidth :: integer(), RowHeight :: integer(), PixelWidth :: integer(), PixelHeight :: integer(), + TerminalModes :: [{Opcode :: atom() | integer(), + Value :: integer()}]}} . +-type terminal_shell_event() :: {shell, WantReply :: boolean()} . +-type terminal_window_change_event() :: {window_change, ssh:channel_id(), CharWidth :: integer(), + RowHeight :: integer(), PixWidth :: integer(), PixHeight :: integer()} . +-type terminal_exec_event() :: {exec, ssh:channel_id(), WantReply :: boolean(), Cmd :: string()} . + +%%% This function is soley to convince all +%%% checks that the type event() exists... +-export([dummy/1]). +-spec dummy(event()) -> false. +dummy(_) -> false. + %%-------------------------------------------------------------------- %%% API %%-------------------------------------------------------------------- @@ -77,14 +150,21 @@ %% application, a system command, or some built-in subsystem. %% -------------------------------------------------------------------- --spec session_channel(connection_ref(), timeout()) -> - {ok, channel_id()} | {error, timeout | closed}. +-spec session_channel(ConnectionRef, Timeout) -> Result when + ConnectionRef :: ssh:connection_ref(), + Timeout :: timeout(), + Result :: {ok, ssh:channel_id()} | {error, reason()} . session_channel(ConnectionHandler, Timeout) -> session_channel(ConnectionHandler, ?DEFAULT_WINDOW_SIZE, ?DEFAULT_PACKET_SIZE, Timeout). --spec session_channel(connection_ref(), integer(), integer(), timeout()) -> - {ok, channel_id()} | {error, timeout | closed}. + +-spec session_channel(ConnectionRef, InitialWindowSize, MaxPacketSize, Timeout) -> Result when + ConnectionRef :: ssh:connection_ref(), + InitialWindowSize :: pos_integer(), + MaxPacketSize :: pos_integer(), + Timeout :: timeout(), + Result :: {ok, ssh:channel_id()} | {error, reason()} . session_channel(ConnectionHandler, InitialWindowSize, MaxPacketSize, Timeout) -> case ssh_connection_handler:open_channel(ConnectionHandler, "session", <<>>, @@ -100,8 +180,11 @@ session_channel(ConnectionHandler, InitialWindowSize, MaxPacketSize, Timeout) -> %% Description: Will request that the server start the %% execution of the given command. %%-------------------------------------------------------------------- --spec exec(connection_ref(), channel_id(), string(), timeout()) -> - success | failure | {error, timeout | closed}. +-spec exec(ConnectionRef, ChannelId, Command, Timeout) -> result() when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Command :: string(), + Timeout :: timeout(). exec(ConnectionHandler, ChannelId, Command, TimeOut) -> ssh_connection_handler:request(ConnectionHandler, self(), ChannelId, "exec", @@ -112,8 +195,10 @@ exec(ConnectionHandler, ChannelId, Command, TimeOut) -> %% defined in /etc/passwd in UNIX systems) be started at the other %% end. %%-------------------------------------------------------------------- --spec shell(connection_ref(), channel_id()) -> - ok | success | failure | {error, timeout}. +-spec shell(ConnectionRef, ChannelId) -> Result when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Result :: ok | success | failure | {error, timeout} . shell(ConnectionHandler, ChannelId) -> ssh_connection_handler:request(ConnectionHandler, self(), ChannelId, @@ -122,8 +207,11 @@ shell(ConnectionHandler, ChannelId) -> %% %% Description: Executes a predefined subsystem. %%-------------------------------------------------------------------- --spec subsystem(connection_ref(), channel_id(), string(), timeout()) -> - success | failure | {error, timeout | closed}. +-spec subsystem(ConnectionRef, ChannelId, Subsystem, Timeout) -> result() when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Subsystem :: string(), + Timeout :: timeout(). subsystem(ConnectionHandler, ChannelId, SubSystem, TimeOut) -> ssh_connection_handler:request(ConnectionHandler, self(), @@ -134,12 +222,13 @@ subsystem(ConnectionHandler, ChannelId, SubSystem, TimeOut) -> %%-------------------------------------------------------------------- -spec send(connection_ref(), channel_id(), iodata()) -> ok | {error, timeout | closed}. + send(ConnectionHandler, ChannelId, Data) -> send(ConnectionHandler, ChannelId, 0, Data, infinity). --spec send(connection_ref(), channel_id(), integer()| iodata(), timeout() | iodata()) -> - ok | {error, timeout | closed}. +-spec send(connection_ref(), channel_id(), iodata(), timeout()) -> ok | {error, reason()}; + (connection_ref(), channel_id(), ssh_data_type_code(), iodata()) -> ok | {error, reason()}. send(ConnectionHandler, ChannelId, Data, TimeOut) when is_integer(TimeOut) -> send(ConnectionHandler, ChannelId, 0, Data, TimeOut); @@ -151,14 +240,15 @@ send(ConnectionHandler, ChannelId, Type, Data) -> send(ConnectionHandler, ChannelId, Type, Data, infinity). --spec send(connection_ref(), channel_id(), integer(), iodata(), timeout()) -> - ok | {error, timeout | closed}. +-spec send(connection_ref(), channel_id(), ssh_data_type_code(), iodata(), timeout()) -> ok | {error, reason()}. send(ConnectionHandler, ChannelId, Type, Data, TimeOut) -> ssh_connection_handler:send(ConnectionHandler, ChannelId, Type, Data, TimeOut). %%-------------------------------------------------------------------- --spec send_eof(connection_ref(), channel_id()) -> ok | {error, closed}. +-spec send_eof(ConnectionRef, ChannelId) -> ok | {error, closed} when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(). %% %% %% Description: Sends eof on the channel . @@ -167,7 +257,10 @@ send_eof(ConnectionHandler, Channel) -> ssh_connection_handler:send_eof(ConnectionHandler, Channel). %%-------------------------------------------------------------------- --spec adjust_window(connection_ref(), channel_id(), integer()) -> ok. +-spec adjust_window(ConnectionRef, ChannelId, NumOfBytes) -> ok when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + NumOfBytes :: integer(). %% %% %% Description: Adjusts the ssh flowcontrol window. @@ -176,8 +269,12 @@ adjust_window(ConnectionHandler, Channel, Bytes) -> ssh_connection_handler:adjust_window(ConnectionHandler, Channel, Bytes). %%-------------------------------------------------------------------- --spec setenv(connection_ref(), channel_id(), string(), string(), timeout()) -> - success | failure | {error, timeout | closed}. +-spec setenv(ConnectionRef, ChannelId, Var, Value, Timeout) -> result() when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Var :: string(), + Value :: string(), + Timeout :: timeout(). %% %% %% Description: Environment variables may be passed to the shell/command to be @@ -189,7 +286,9 @@ setenv(ConnectionHandler, ChannelId, Var, Value, TimeOut) -> %%-------------------------------------------------------------------- --spec close(connection_ref(), channel_id()) -> ok. +-spec close(ConnectionRef, ChannelId) -> ok when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(). %% %% %% Description: Sends a close message on the channel . @@ -198,7 +297,11 @@ close(ConnectionHandler, ChannelId) -> ssh_connection_handler:close(ConnectionHandler, ChannelId). %%-------------------------------------------------------------------- --spec reply_request(connection_ref(), boolean(), success | failure, channel_id()) -> ok. +-spec reply_request(ConnectionRef, WantReply, Status, ChannelId) -> ok when + ConnectionRef :: ssh:connection_ref(), + WantReply :: boolean(), + Status :: req_status(), + ChannelId :: ssh:channel_id(). %% %% %% Description: Send status replies to requests that want such replies. @@ -211,15 +314,20 @@ reply_request(_,false, _, _) -> %%-------------------------------------------------------------------- %% Description: Sends a ssh connection protocol pty_req. %%-------------------------------------------------------------------- --spec ptty_alloc(connection_ref(), channel_id(), proplists:proplist()) -> - success | failure | {error, timeout}. +-spec ptty_alloc(ConnectionRef, ChannelId, Options) -> result() when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Options :: proplists:proplist(). ptty_alloc(ConnectionHandler, Channel, Options) -> ptty_alloc(ConnectionHandler, Channel, Options, infinity). --spec ptty_alloc(connection_ref(), channel_id(), proplists:proplist(), timeout()) -> - success | failure | {error, timeout | closed}. +-spec ptty_alloc(ConnectionRef, ChannelId, Options, Timeout) -> result() when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Options :: proplists:proplist(), + Timeout :: timeout(). ptty_alloc(ConnectionHandler, Channel, Options0, TimeOut) -> TermData = backwards_compatible(Options0, []), % FIXME @@ -252,6 +360,10 @@ signal(ConnectionHandler, Channel, Sig) -> "signal", false, [?string(Sig)], 0). +-spec exit_status(ConnectionRef, ChannelId, Status) -> ok when + ConnectionRef :: ssh:connection_ref(), + ChannelId :: ssh:channel_id(), + Status :: integer(). exit_status(ConnectionHandler, Channel, Status) -> ssh_connection_handler:request(ConnectionHandler, Channel, "exit-status", false, [?uint32(Status)], 0). -- cgit v1.2.3