niceSOFT/libssh2: the SSH library

include/libssh2.h
476 строк25 KB
Dan Fandrich
Stop shadowing a global declaration
28 сен 2007, 22:29
28 сен 2007, 22:292d773f9
/* Copyright (c) 2004-2007, Sara Golemon <sarag@libssh2.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms,
 * with or without modification, are permitted provided
 * that the following conditions are met:
 *
 *   Redistributions of source code must retain the above
 *   copyright notice, this list of conditions and the
 *   following disclaimer.
 *
 *   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.
 *
 *   Neither the name of the copyright holder nor the names
 *   of any other contributors may be used to endorse or
 *   promote products derived from this software without
 *   specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

#ifndef LIBSSH2_H
#define LIBSSH2_H 1

#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>

/* Allow alternate API prefix from CFLAGS or calling app */
#ifndef LIBSSH2_API
# ifdef LIBSSH2_WIN32
#  ifdef LIBSSH2_LIBRARY
#   define LIBSSH2_API __declspec(dllexport)
#  else
#   define LIBSSH2_API __declspec(dllimport)
#  endif /* LIBSSH2_LIBRARY */
# else /* !LIBSSH2_WIN32 */
#  define LIBSSH2_API
# endif /* LIBSSH2_WIN32 */
#endif /* LIBSSH2_API */

#if defined(LIBSSH2_DARWIN) || (defined(LIBSSH2_WIN32) && !defined(_MSC_VER) && !defined(__MINGW32__))
# include <sys/uio.h>
#endif

#if (defined(NETWARE) && !defined(__NOVELL_LIBC__))
# include <sys/bsdskt.h>
typedef unsigned int uint32_t;
#endif

#if defined(LIBSSH2_WIN32) && defined(_MSC_VER) && (_MSC_VER <= 1400)
typedef unsigned __int64 libssh2_uint64_t;
typedef __int64 libssh2_int64_t;
typedef unsigned int uint32_t;
#ifndef _SSIZE_T_DEFINED
typedef int ssize_t;
#define _SSIZE_T_DEFINED
#endif
#else
typedef unsigned long long libssh2_uint64_t;
typedef long long libssh2_int64_t;
#endif

#define LIBSSH2_VERSION                             "0.18.0-CVS"

/* The numeric version number is also available "in parts" by using these
   defines: */
#define LIBSSH2_VERSION_MAJOR                       0
#define LIBSSH2_VERSION_MINOR                       18
#define LIBSSH2_VERSION_PATCH                       0

/* This is the numeric version of the libssh2 version number, meant for easier
   parsing and comparions by programs. The LIBSSH2_VERSION_NUM define will
   always follow this syntax:

         0xXXYYZZ

   Where XX, YY and ZZ are the main version, release and patch numbers in
   hexadecimal (using 8 bits each). All three numbers are always represented
   using two digits.  1.2 would appear as "0x010200" while version 9.11.7
   appears as "0x090b07".

   This 6-digit (24 bits) hexadecimal number does not show pre-release number,
   and it is always a greater number in a more recent release. It makes
   comparisons with greater than and less than work.
*/
#define LIBSSH2_VERSION_NUM                         0x001200

/*
 * This is the date and time when the full source package was created. The
 * timestamp is not stored in CVS, as the timestamp is properly set in the
 * tarballs by the maketgz script.
 *
 * The format of the date should follow this template:
 *
 * "Mon Feb 12 11:35:33 UTC 2007"
 */
#define LIBSSH2_TIMESTAMP "CVS"

/* Part of every banner, user specified or not */
#define LIBSSH2_SSH_BANNER                  "SSH-2.0-libssh2_" LIBSSH2_VERSION

/* We *could* add a comment here if we so chose */
#define LIBSSH2_SSH_DEFAULT_BANNER                  LIBSSH2_SSH_BANNER
#define LIBSSH2_SSH_DEFAULT_BANNER_WITH_CRLF        LIBSSH2_SSH_DEFAULT_BANNER "\r\n"

/* Default generate and safe prime sizes for diffie-hellman-group-exchange-sha1 */
#define LIBSSH2_DH_GEX_MINGROUP     1024
#define LIBSSH2_DH_GEX_OPTGROUP     1536
#define LIBSSH2_DH_GEX_MAXGROUP     2048

/* Defaults for pty requests */
#define LIBSSH2_TERM_WIDTH      80
#define LIBSSH2_TERM_HEIGHT     24
#define LIBSSH2_TERM_WIDTH_PX   0
#define LIBSSH2_TERM_HEIGHT_PX  0

/* 1/4 second */
#define LIBSSH2_SOCKET_POLL_UDELAY      250000
/* 0.25 * 120 == 30 seconds */
#define LIBSSH2_SOCKET_POLL_MAXLOOPS    120

/* Maximum size to allow a payload to compress to, plays it safe by falling short of spec limits */
#define LIBSSH2_PACKET_MAXCOMP      32000

/* Maximum size to allow a payload to deccompress to, plays it safe by allowing more than spec requires */
#define LIBSSH2_PACKET_MAXDECOMP    40000

/* Maximum size for an inbound compressed payload, plays it safe by overshooting spec limits */
#define LIBSSH2_PACKET_MAXPAYLOAD   40000

/* Malloc callbacks */
#define LIBSSH2_ALLOC_FUNC(name)                    void *name(size_t count, void **abstract)
#define LIBSSH2_REALLOC_FUNC(name)                  void *name(void *ptr, size_t count, void **abstract)
#define LIBSSH2_FREE_FUNC(name)                     void name(void *ptr, void **abstract)

typedef struct _LIBSSH2_USERAUTH_KBDINT_PROMPT
{
    char* text;
    unsigned int length;
    unsigned char echo;
} LIBSSH2_USERAUTH_KBDINT_PROMPT;

typedef struct _LIBSSH2_USERAUTH_KBDINT_RESPONSE
{
    char* text;
    unsigned int length;
} LIBSSH2_USERAUTH_KBDINT_RESPONSE;

/* 'keyboard-interactive' authentication callback */
#define LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC(name_) void name_(const char* name, int name_len, const char* instruction, int instruction_len, int num_prompts, const LIBSSH2_USERAUTH_KBDINT_PROMPT* prompts, LIBSSH2_USERAUTH_KBDINT_RESPONSE* responses, void **abstract)

/* Callbacks for special SSH packets */
#define LIBSSH2_IGNORE_FUNC(name)                   void name(LIBSSH2_SESSION *session, const char *message, int message_len, void **abstract)
#define LIBSSH2_DEBUG_FUNC(name)                    void name(LIBSSH2_SESSION *session, int always_display, const char *message, int message_len, const char *language, int language_len,void **abstract)
#define LIBSSH2_DISCONNECT_FUNC(name)               void name(LIBSSH2_SESSION *session, int reason, const char *message, int message_len, const char *language, int language_len, void **abstract)
#define LIBSSH2_PASSWD_CHANGEREQ_FUNC(name)         void name(LIBSSH2_SESSION *session, char **newpw, int *newpw_len, void **abstract)
#define LIBSSH2_MACERROR_FUNC(name)                 int  name(LIBSSH2_SESSION *session, const char *packet, int packet_len, void **abstract)
#define LIBSSH2_X11_OPEN_FUNC(name)                 void name(LIBSSH2_SESSION *session, LIBSSH2_CHANNEL *channel, const char *shost, int sport, void **abstract)

#define LIBSSH2_CHANNEL_CLOSE_FUNC(name)            void name(LIBSSH2_SESSION *session, void **session_abstract, LIBSSH2_CHANNEL *channel, void **channel_abstract)

/* libssh2_session_callback_set() constants */
#define LIBSSH2_CALLBACK_IGNORE             0
#define LIBSSH2_CALLBACK_DEBUG              1
#define LIBSSH2_CALLBACK_DISCONNECT         2
#define LIBSSH2_CALLBACK_MACERROR           3
#define LIBSSH2_CALLBACK_X11                4

/* libssh2_session_method_pref() constants */
#define LIBSSH2_METHOD_KEX          0
#define LIBSSH2_METHOD_HOSTKEY      1
#define LIBSSH2_METHOD_CRYPT_CS     2
#define LIBSSH2_METHOD_CRYPT_SC     3
#define LIBSSH2_METHOD_MAC_CS       4
#define LIBSSH2_METHOD_MAC_SC       5
#define LIBSSH2_METHOD_COMP_CS      6
#define LIBSSH2_METHOD_COMP_SC      7
#define LIBSSH2_METHOD_LANG_CS      8
#define LIBSSH2_METHOD_LANG_SC      9

/* session.flags bits */
#define LIBSSH2_FLAG_SIGPIPE        0x00000001

typedef struct _LIBSSH2_SESSION                     LIBSSH2_SESSION;
typedef struct _LIBSSH2_CHANNEL                     LIBSSH2_CHANNEL;
typedef struct _LIBSSH2_LISTENER                    LIBSSH2_LISTENER;

typedef struct _LIBSSH2_POLLFD {
    unsigned char type; /* LIBSSH2_POLLFD_* below */

    union {
        int socket; /* File descriptors -- examined with system select() call */
        LIBSSH2_CHANNEL *channel; /* Examined by checking internal state */
        LIBSSH2_LISTENER *listener; /* Read polls only -- are inbound connections waiting to be accepted? */
    } fd;

    unsigned long events; /* Requested Events */
    unsigned long revents; /* Returned Events */
} LIBSSH2_POLLFD;

/* Poll FD Descriptor Types */
#define LIBSSH2_POLLFD_SOCKET       1
#define LIBSSH2_POLLFD_CHANNEL      2
#define LIBSSH2_POLLFD_LISTENER     3

/* Note: Win32 Doesn't actually have a poll() implementation, so some of these values are faked with select() data */
/* Poll FD events/revents -- Match sys/poll.h where possible */
#define LIBSSH2_POLLFD_POLLIN           0x0001      /* Data available to be read or connection available -- All */
#define LIBSSH2_POLLFD_POLLPRI          0x0002      /* Priority data available to be read -- Socket only */
#define LIBSSH2_POLLFD_POLLEXT          0x0002      /* Extended data available to be read -- Channel only */
#define LIBSSH2_POLLFD_POLLOUT          0x0004      /* Can may be written -- Socket/Channel */
/* revents only */
#define LIBSSH2_POLLFD_POLLERR          0x0008      /* Error Condition -- Socket */
#define LIBSSH2_POLLFD_POLLHUP          0x0010      /* HangUp/EOF -- Socket */
#define LIBSSH2_POLLFD_SESSION_CLOSED   0x0010      /* Session Disconnect */
#define LIBSSH2_POLLFD_POLLNVAL         0x0020      /* Invalid request -- Socket Only */
#define LIBSSH2_POLLFD_POLLEX           0x0040      /* Exception Condition -- Socket/Win32 */
#define LIBSSH2_POLLFD_CHANNEL_CLOSED   0x0080      /* Channel Disconnect */
#define LIBSSH2_POLLFD_LISTENER_CLOSED  0x0080      /* Listener Disconnect */

/* Hash Types */
#define LIBSSH2_HOSTKEY_HASH_MD5                            1
#define LIBSSH2_HOSTKEY_HASH_SHA1                           2

/* Disconnect Codes (defined by SSH protocol) */
#define SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT          1
#define SSH_DISCONNECT_PROTOCOL_ERROR                       2
#define SSH_DISCONNECT_KEY_EXCHANGE_FAILED                  3
#define SSH_DISCONNECT_RESERVED                             4
#define SSH_DISCONNECT_MAC_ERROR                            5
#define SSH_DISCONNECT_COMPRESSION_ERROR                    6
#define SSH_DISCONNECT_SERVICE_NOT_AVAILABLE                7
#define SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED       8
#define SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE              9
#define SSH_DISCONNECT_CONNECTION_LOST                      10
#define SSH_DISCONNECT_BY_APPLICATION                       11
#define SSH_DISCONNECT_TOO_MANY_CONNECTIONS                 12
#define SSH_DISCONNECT_AUTH_CANCELLED_BY_USER               13
#define SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE       14
#define SSH_DISCONNECT_ILLEGAL_USER_NAME                    15

/* Error Codes (defined by libssh2) */
#define LIBSSH2_ERROR_NONE                      0
#define LIBSSH2_ERROR_SOCKET_NONE               -1
#define LIBSSH2_ERROR_BANNER_NONE               -2
#define LIBSSH2_ERROR_BANNER_SEND               -3
#define LIBSSH2_ERROR_INVALID_MAC               -4
#define LIBSSH2_ERROR_KEX_FAILURE               -5
#define LIBSSH2_ERROR_ALLOC                     -6
#define LIBSSH2_ERROR_SOCKET_SEND               -7
#define LIBSSH2_ERROR_KEY_EXCHANGE_FAILURE      -8
#define LIBSSH2_ERROR_TIMEOUT                   -9
#define LIBSSH2_ERROR_HOSTKEY_INIT              -10
#define LIBSSH2_ERROR_HOSTKEY_SIGN              -11
#define LIBSSH2_ERROR_DECRYPT                   -12
#define LIBSSH2_ERROR_SOCKET_DISCONNECT         -13
#define LIBSSH2_ERROR_PROTO                     -14
#define LIBSSH2_ERROR_PASSWORD_EXPIRED          -15
#define LIBSSH2_ERROR_FILE                      -16
#define LIBSSH2_ERROR_METHOD_NONE               -17
#define LIBSSH2_ERROR_PUBLICKEY_UNRECOGNIZED    -18
#define LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED      -19
#define LIBSSH2_ERROR_CHANNEL_OUTOFORDER        -20
#define LIBSSH2_ERROR_CHANNEL_FAILURE           -21
#define LIBSSH2_ERROR_CHANNEL_REQUEST_DENIED    -22
#define LIBSSH2_ERROR_CHANNEL_UNKNOWN           -23
#define LIBSSH2_ERROR_CHANNEL_WINDOW_EXCEEDED   -24
#define LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED   -25
#define LIBSSH2_ERROR_CHANNEL_CLOSED            -26
#define LIBSSH2_ERROR_CHANNEL_EOF_SENT          -27
#define LIBSSH2_ERROR_SCP_PROTOCOL              -28
#define LIBSSH2_ERROR_ZLIB                      -29
#define LIBSSH2_ERROR_SOCKET_TIMEOUT            -30
#define LIBSSH2_ERROR_SFTP_PROTOCOL             -31
#define LIBSSH2_ERROR_REQUEST_DENIED            -32
#define LIBSSH2_ERROR_METHOD_NOT_SUPPORTED      -33
#define LIBSSH2_ERROR_INVAL                     -34
#define LIBSSH2_ERROR_INVALID_POLL_TYPE         -35
#define LIBSSH2_ERROR_PUBLICKEY_PROTOCOL        -36
#define LIBSSH2_ERROR_EAGAIN                    -37

/* Session API */
LIBSSH2_API LIBSSH2_SESSION *libssh2_session_init_ex(LIBSSH2_ALLOC_FUNC((*my_alloc)), LIBSSH2_FREE_FUNC((*my_free)), LIBSSH2_REALLOC_FUNC((*my_realloc)), void *abstract);
#define libssh2_session_init()                      libssh2_session_init_ex(NULL, NULL, NULL, NULL)
LIBSSH2_API void **libssh2_session_abstract(LIBSSH2_SESSION *session);

LIBSSH2_API void *libssh2_session_callback_set(LIBSSH2_SESSION *session, int cbtype, void *callback);
LIBSSH2_API int libssh2_banner_set(LIBSSH2_SESSION *session, const char *banner);

LIBSSH2_API int libssh2_session_startup(LIBSSH2_SESSION *session, int sock);
LIBSSH2_API int libssh2_session_disconnect_ex(LIBSSH2_SESSION *session, int reason, const char *description, const char *lang);
#define libssh2_session_disconnect(session, description)    libssh2_session_disconnect_ex((session), SSH_DISCONNECT_BY_APPLICATION, (description), "")
LIBSSH2_API int libssh2_session_free(LIBSSH2_SESSION *session);

LIBSSH2_API const char *libssh2_hostkey_hash(LIBSSH2_SESSION *session, int hash_type);

LIBSSH2_API int libssh2_session_method_pref(LIBSSH2_SESSION *session, int method_type, const char *prefs);
LIBSSH2_API const char *libssh2_session_methods(LIBSSH2_SESSION *session, int method_type);
LIBSSH2_API int libssh2_session_last_error(LIBSSH2_SESSION *session, char **errmsg, int *errmsg_len, int want_buf);
LIBSSH2_API int libssh2_session_last_errno(LIBSSH2_SESSION *session);

LIBSSH2_API int libssh2_session_flag(LIBSSH2_SESSION *session, int flag, int value);

/* Userauth API */
LIBSSH2_API char *libssh2_userauth_list(LIBSSH2_SESSION *session, const char *username, unsigned int username_len);
LIBSSH2_API int libssh2_userauth_authenticated(LIBSSH2_SESSION *session);
LIBSSH2_API int libssh2_userauth_password_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len, const char *password, unsigned int password_len, LIBSSH2_PASSWD_CHANGEREQ_FUNC((*passwd_change_cb)));
#define libssh2_userauth_password(session, username, password)  libssh2_userauth_password_ex((session), (username), strlen(username), (password), strlen(password), NULL)

LIBSSH2_API int libssh2_userauth_publickey_fromfile_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
                                                                                 const char *publickey, const char *privatekey,
                                                                                 const char *passphrase);
#define libssh2_userauth_publickey_fromfile(session, username, publickey, privatekey, passphrase)   \
        libssh2_userauth_publickey_fromfile_ex((session), (username), strlen(username), (publickey), (privatekey), (passphrase))
LIBSSH2_API int libssh2_userauth_hostbased_fromfile_ex(LIBSSH2_SESSION *session, const char *username, unsigned int username_len,
                                                                                 const char *publickey, const char *privatekey,
                                                                                 const char *passphrase,
                                                                                 const char *hostname, unsigned int hostname_len,
                                                                                 const char *local_username, unsigned int local_username_len);
#define libssh2_userauth_hostbased_fromfile(session, username, publickey, privatekey, passphrase, hostname) \
        libssh2_userauth_hostbased_fromfile_ex((session), (username), strlen(username), (publickey), (privatekey), (passphrase), (hostname), strlen(hostname), (username), strlen(username))

/*
 * response_callback is provided with filled by library prompts array,
 * but client must allocate and fill individual responses. Responses
 * array is already allocated. Responses data will be freed by libssh2
 * after callback return, but before subsequent callback invokation.
 */
LIBSSH2_API int libssh2_userauth_keyboard_interactive_ex(LIBSSH2_SESSION* session, const char *username, unsigned int username_len,
                                                         LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC((*response_callback)));
#define libssh2_userauth_keyboard_interactive(session, username, response_callback) \
        libssh2_userauth_keyboard_interactive_ex((session), (username), strlen(username), (response_callback))

LIBSSH2_API int libssh2_poll(LIBSSH2_POLLFD *fds, unsigned int nfds, long timeout);

/* Channel API */
#define LIBSSH2_CHANNEL_WINDOW_DEFAULT  65536
#define LIBSSH2_CHANNEL_PACKET_DEFAULT  16384
#define LIBSSH2_CHANNEL_MINADJUST       1024

/* Extended Data Handling */
#define LIBSSH2_CHANNEL_EXTENDED_DATA_NORMAL        0
#define LIBSSH2_CHANNEL_EXTENDED_DATA_IGNORE        1
#define LIBSSH2_CHANNEL_EXTENDED_DATA_MERGE         2

#define SSH_EXTENDED_DATA_STDERR 1

/* Returned by any function that would block during a read/write opperation */
#define LIBSSH2CHANNEL_EAGAIN LIBSSH2_ERROR_EAGAIN

LIBSSH2_API LIBSSH2_CHANNEL *libssh2_channel_open_ex(LIBSSH2_SESSION *session, const char *channel_type, unsigned int channel_type_len, unsigned int window_size, unsigned int packet_size, const char *message, unsigned int message_len);
#define libssh2_channel_open_session(session)   libssh2_channel_open_ex((session), "session", sizeof("session") - 1, LIBSSH2_CHANNEL_WINDOW_DEFAULT, LIBSSH2_CHANNEL_PACKET_DEFAULT, NULL, 0)

LIBSSH2_API LIBSSH2_CHANNEL *libssh2_channel_direct_tcpip_ex(LIBSSH2_SESSION *session, const char *host, int port, const char *shost, int sport);
#define libssh2_channel_direct_tcpip(session, host, port)   libssh2_channel_direct_tcpip_ex((session), (host), (port), "127.0.0.1", 22)

LIBSSH2_API LIBSSH2_LISTENER *libssh2_channel_forward_listen_ex(LIBSSH2_SESSION *session, const char *host, int port, int *bound_port, int queue_maxsize);
#define libssh2_channel_forward_listen(session, port)           libssh2_channel_forward_listen_ex((session), NULL, (port), NULL, 16)

LIBSSH2_API int libssh2_channel_forward_cancel(LIBSSH2_LISTENER *listener);

LIBSSH2_API LIBSSH2_CHANNEL *libssh2_channel_forward_accept(LIBSSH2_LISTENER *listener);

LIBSSH2_API int libssh2_channel_setenv_ex(LIBSSH2_CHANNEL *channel, const char *varname, unsigned int varname_len, const char *value, unsigned int value_len);
#define libssh2_channel_setenv(channel, varname, value) libssh2_channel_setenv_ex((channel), (varname), strlen(varname), (value), strlen(value))

LIBSSH2_API int libssh2_channel_request_pty_ex(LIBSSH2_CHANNEL *channel, const char *term, unsigned int term_len, const char *modes, unsigned int modes_len, int width, int height, int width_px, int height_px);
#define libssh2_channel_request_pty(channel, term)  libssh2_channel_request_pty_ex((channel), (term), strlen(term), NULL, 0, LIBSSH2_TERM_WIDTH, LIBSSH2_TERM_HEIGHT, LIBSSH2_TERM_WIDTH_PX, LIBSSH2_TERM_HEIGHT_PX)

LIBSSH2_API int libssh2_channel_x11_req_ex(LIBSSH2_CHANNEL *channel, int single_connection, const char *auth_proto, const char *auth_cookie, int screen_number);
#define libssh2_channel_x11_req(channel, screen_number) libssh2_channel_x11_req_ex((channel), 0, NULL, NULL, (screen_number))

LIBSSH2_API int libssh2_channel_process_startup(LIBSSH2_CHANNEL *channel, const char *request, unsigned int request_len, const char *message, unsigned int message_len);
#define libssh2_channel_shell(channel)                  libssh2_channel_process_startup((channel), "shell", sizeof("shell") - 1, NULL, 0)
#define libssh2_channel_exec(channel, command)          libssh2_channel_process_startup((channel), "exec", sizeof("exec") - 1, (command), strlen(command))
#define libssh2_channel_subsystem(channel, subsystem)   libssh2_channel_process_startup((channel), "subsystem", sizeof("subsystem") - 1, (subsystem), strlen(subsystem))

LIBSSH2_API ssize_t libssh2_channel_read_ex(LIBSSH2_CHANNEL *channel, int stream_id, char *buf, size_t buflen);
#define libssh2_channel_read(channel, buf, buflen) \
                                libssh2_channel_read_ex((channel), 0, (buf), (buflen))
#define libssh2_channel_read_stderr(channel, buf, buflen) \
                                libssh2_channel_read_ex((channel), SSH_EXTENDED_DATA_STDERR, (buf), (buflen))

LIBSSH2_API int libssh2_poll_channel_read(LIBSSH2_CHANNEL *channel, int extended);

LIBSSH2_API unsigned long libssh2_channel_window_read_ex(LIBSSH2_CHANNEL *channel, unsigned long *read_avail, unsigned long *window_size_initial);
#define libssh2_channel_window_read(channel) \
            libssh2_channel_window_read_ex((channel), NULL, NULL)

LIBSSH2_API unsigned long libssh2_channel_receive_window_adjust(LIBSSH2_CHANNEL *channel, unsigned long adjustment, unsigned char force);

LIBSSH2_API ssize_t libssh2_channel_write_ex(LIBSSH2_CHANNEL *channel, int stream_id, const char *buf, size_t buflen);

#define libssh2_channel_write(channel, buf, buflen) \
                                libssh2_channel_write_ex((channel), 0, (buf), (buflen))
#define libssh2_channel_write_stderr(channel, buf, buflen)  \
                                libssh2_channel_write_ex((channel), SSH_EXTENDED_DATA_STDERR, (buf), (buflen))

LIBSSH2_API unsigned long libssh2_channel_window_write_ex(LIBSSH2_CHANNEL *channel, unsigned long *window_size_initial);
#define libssh2_channel_window_write(channel)           libssh2_channel_window_write_ex((channel), NULL)

LIBSSH2_API void libssh2_session_set_blocking(LIBSSH2_SESSION* session, int blocking);
LIBSSH2_API int libssh2_session_get_blocking(LIBSSH2_SESSION* session);

LIBSSH2_API void libssh2_channel_set_blocking(LIBSSH2_CHANNEL *channel, int blocking);

LIBSSH2_API void libssh2_channel_handle_extended_data(LIBSSH2_CHANNEL *channel, int ignore_mode);
LIBSSH2_API int libssh2_channel_handle_extended_data2(LIBSSH2_CHANNEL *channel, int ignore_mode);
/* libssh2_channel_ignore_extended_data() is defined below for BC with version 0.1
 * Future uses should use libssh2_channel_handle_extended_data() directly
 * if LIBSSH2_CHANNEL_EXTENDED_DATA_MERGE is passed, extended data will be read (FIFO) from the standard data channel
 */
/* DEPRECATED */
#define libssh2_channel_ignore_extended_data(channel, ignore)       libssh2_channel_handle_extended_data((channel), (ignore) ? LIBSSH2_CHANNEL_EXTENDED_DATA_IGNORE : LIBSSH2_CHANNEL_EXTENDED_DATA_NORMAL )

#define LIBSSH2_CHANNEL_FLUSH_EXTENDED_DATA     -1
#define LIBSSH2_CHANNEL_FLUSH_ALL               -2
LIBSSH2_API int libssh2_channel_flush_ex(LIBSSH2_CHANNEL *channel, int streamid);
#define libssh2_channel_flush(channel)          libssh2_channel_flush_ex((channel), 0)
#define libssh2_channel_flush_stderr(channel)   libssh2_channel_flush_ex((channel), SSH_EXTENDED_DATA_STDERR)
LIBSSH2_API int libssh2_channel_get_exit_status(LIBSSH2_CHANNEL* channel);

LIBSSH2_API int libssh2_channel_send_eof(LIBSSH2_CHANNEL *channel);
LIBSSH2_API int libssh2_channel_eof(LIBSSH2_CHANNEL *channel);
LIBSSH2_API int libssh2_channel_wait_eof(LIBSSH2_CHANNEL *channel);
LIBSSH2_API int libssh2_channel_close(LIBSSH2_CHANNEL *channel);
LIBSSH2_API int libssh2_channel_wait_closed(LIBSSH2_CHANNEL *channel);
LIBSSH2_API int libssh2_channel_free(LIBSSH2_CHANNEL *channel);

LIBSSH2_API LIBSSH2_CHANNEL *libssh2_scp_recv(LIBSSH2_SESSION *session, const char *path, struct stat *sb);
LIBSSH2_API LIBSSH2_CHANNEL *libssh2_scp_send_ex(LIBSSH2_SESSION *session, const char *path, int mode, size_t size, long mtime, long atime);
#define libssh2_scp_send(session, path, mode, size)                 libssh2_scp_send_ex((session), (path), (mode), (size), 0, 0)

LIBSSH2_API int libssh2_base64_decode(LIBSSH2_SESSION *session, char **dest, unsigned int *dest_len, const char *src, unsigned int src_len);

/* NOTE NOTE NOTE
   libssh2_trace() has no function in builds that aren't built with debug
   enabled
 */
LIBSSH2_API int libssh2_trace(LIBSSH2_SESSION *session, int bitmask);
#define LIBSSH2_TRACE_TRANS (1<<1)
#define LIBSSH2_TRACE_KEX   (1<<2)
#define LIBSSH2_TRACE_AUTH  (1<<3)
#define LIBSSH2_TRACE_CONN  (1<<4)
#define LIBSSH2_TRACE_SCP   (1<<5)
#define LIBSSH2_TRACE_SFTP  (1<<6)
#define LIBSSH2_TRACE_ERROR (1<<7)
#define LIBSSH2_TRACE_PUBLICKEY (1<<8)

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* LIBSSH2_H */