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channels.c
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3995 lines (3527 loc) · 109 KB
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/*
* channels.c - SSH channel functions
*
* This file is part of the SSH Library
*
* Copyright (c) 2003-2013 by Aris Adamantiadis
* Copyright (c) 2009-2013 by Andreas Schneider <asn@cryptomilk.org>
*
* 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.
*/
#include "config.h"
#include <limits.h>
#include <stdio.h>
#include <errno.h>
#include <time.h>
#include <stdbool.h>
#include <string.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif /* HAVE_SYS_TIME_H */
#ifndef _WIN32
#include <netinet/in.h>
#include <arpa/inet.h>
#endif
#include "libssh/priv.h"
#include "libssh/ssh2.h"
#include "libssh/buffer.h"
#include "libssh/packet.h"
#include "libssh/socket.h"
#include "libssh/channels.h"
#include "libssh/session.h"
#include "libssh/misc.h"
#include "libssh/messages.h"
#if WITH_SERVER
#include "libssh/server.h"
#endif
/*
* All implementations MUST be able to process packets with an
* uncompressed payload length of 32768 bytes or less and a total packet
* size of 35000 bytes or less.
*/
#define CHANNEL_MAX_PACKET 32768
/*
* WINDOW_DEFAULT matches the default OpenSSH session window size.
* This controls how much data the peer can send before needing to receive
* a round-trip SSH2_MSG_CHANNEL_WINDOW_ADJUST message that increases the window.
*/
#define WINDOW_DEFAULT (64*CHANNEL_MAX_PACKET)
/**
* @defgroup libssh_channel The SSH channel functions
* @ingroup libssh
*
* Functions that manage a SSH channel.
*
* @{
*/
static ssh_channel channel_from_msg(ssh_session session, ssh_buffer packet);
/**
* @brief Allocate a new channel.
*
* @param[in] session The ssh session to use.
*
* @return A pointer to a newly allocated channel, NULL on error.
* The channel needs to be freed with ssh_channel_free().
*
* @see ssh_channel_free()
*/
ssh_channel ssh_channel_new(ssh_session session)
{
ssh_channel channel = NULL;
if (session == NULL) {
return NULL;
}
/* Check if we have an authenticated session */
if (!(session->flags & SSH_SESSION_FLAG_AUTHENTICATED)) {
return NULL;
}
channel = calloc(1, sizeof(struct ssh_channel_struct));
if (channel == NULL) {
ssh_set_error_oom(session);
return NULL;
}
channel->stdout_buffer = ssh_buffer_new();
if (channel->stdout_buffer == NULL) {
ssh_set_error_oom(session);
SAFE_FREE(channel);
return NULL;
}
channel->stderr_buffer = ssh_buffer_new();
if (channel->stderr_buffer == NULL) {
ssh_set_error_oom(session);
SSH_BUFFER_FREE(channel->stdout_buffer);
SAFE_FREE(channel);
return NULL;
}
channel->session = session;
channel->exit.code = (uint32_t)-1;
channel->flags = SSH_CHANNEL_FLAG_NOT_BOUND;
if (session->channels == NULL) {
session->channels = ssh_list_new();
if (session->channels == NULL) {
ssh_set_error_oom(session);
SSH_BUFFER_FREE(channel->stdout_buffer);
SSH_BUFFER_FREE(channel->stderr_buffer);
SAFE_FREE(channel);
return NULL;
}
}
ssh_list_prepend(session->channels, channel);
/* Set states explicitly */
channel->state = SSH_CHANNEL_STATE_NOT_OPEN;
channel->request_state = SSH_CHANNEL_REQ_STATE_NONE;
return channel;
}
/**
* @internal
*
* @brief Create a new channel identifier.
*
* @param[in] session The SSH session to use.
*
* @return The new channel identifier.
*/
uint32_t ssh_channel_new_id(ssh_session session)
{
return ++(session->maxchannel);
}
/**
* @internal
*
* @brief Handle a SSH_PACKET_CHANNEL_OPEN_CONFIRMATION packet.
*
* Constructs the channel object.
*/
SSH_PACKET_CALLBACK(ssh_packet_channel_open_conf){
uint32_t channelid=0;
ssh_channel channel = NULL;
int rc;
(void)type;
(void)user;
SSH_LOG(SSH_LOG_PACKET,"Received SSH2_MSG_CHANNEL_OPEN_CONFIRMATION");
rc = ssh_buffer_unpack(packet, "d", &channelid);
if (rc != SSH_OK)
goto error;
channel=ssh_channel_from_local(session,channelid);
if(channel==NULL){
ssh_set_error(session, SSH_FATAL,
"Unknown channel id %" PRIu32,
(uint32_t) channelid);
/* TODO: Set error marking in channel object */
return SSH_PACKET_USED;
}
rc = ssh_buffer_unpack(packet, "ddd",
&channel->remote_channel,
&channel->remote_window,
&channel->remote_maxpacket);
if (rc != SSH_OK)
goto error;
SSH_LOG(SSH_LOG_DEBUG,
"Received a CHANNEL_OPEN_CONFIRMATION for channel %" PRIu32 ":%" PRIu32,
channel->local_channel,
channel->remote_channel);
if (channel->state != SSH_CHANNEL_STATE_OPENING) {
SSH_LOG(SSH_LOG_RARE,
"SSH2_MSG_CHANNEL_OPEN_CONFIRMATION received in incorrect "
"channel state %d",
channel->state);
goto error;
}
SSH_LOG(SSH_LOG_DEBUG,
"Remote window : %" PRIu32 ", maxpacket : %" PRIu32,
channel->remote_window,
channel->remote_maxpacket);
channel->state = SSH_CHANNEL_STATE_OPEN;
channel->flags &= ~SSH_CHANNEL_FLAG_NOT_BOUND;
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_open_response_function,
channel->session,
channel,
true /* is_success */);
return SSH_PACKET_USED;
error:
ssh_set_error(session, SSH_FATAL, "Invalid packet");
return SSH_PACKET_USED;
}
/**
* @internal
*
* @brief Handle a SSH_CHANNEL_OPEN_FAILURE and set the state of the channel.
*/
SSH_PACKET_CALLBACK(ssh_packet_channel_open_fail){
ssh_channel channel = NULL;
char *error = NULL;
uint32_t code;
int rc;
(void)user;
(void)type;
channel=channel_from_msg(session,packet);
if(channel==NULL){
SSH_LOG(SSH_LOG_RARE,"Invalid channel in packet");
return SSH_PACKET_USED;
}
rc = ssh_buffer_unpack(packet, "ds", &code, &error);
if (rc != SSH_OK){
ssh_set_error(session, SSH_FATAL, "Invalid packet");
return SSH_PACKET_USED;
}
if (channel->state != SSH_CHANNEL_STATE_OPENING) {
SSH_LOG(SSH_LOG_RARE,
"SSH2_MSG_CHANNEL_OPEN_FAILURE received in incorrect channel "
"state %d",
channel->state);
SAFE_FREE(error);
goto error;
}
ssh_set_error(session, SSH_REQUEST_DENIED,
"Channel opening failure: channel %" PRIu32 " error (%" PRIu32 ") %s",
channel->local_channel,
code,
error);
SAFE_FREE(error);
channel->state=SSH_CHANNEL_STATE_OPEN_DENIED;
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_open_response_function,
channel->session,
channel,
false /* is_success */);
return SSH_PACKET_USED;
error:
ssh_set_error(session, SSH_FATAL, "Invalid packet");
return SSH_PACKET_USED;
}
static int ssh_channel_open_termination(void *c)
{
ssh_channel channel = (ssh_channel) c;
if (channel->state != SSH_CHANNEL_STATE_OPENING ||
channel->session->session_state == SSH_SESSION_STATE_ERROR)
return 1;
else
return 0;
}
/**
* @internal
*
* @brief Open a channel by sending a SSH_OPEN_CHANNEL message and
* wait for the reply.
*
* @param[in] channel The current channel.
*
* @param[in] type A C string describing the kind of channel (e.g. "exec").
*
* @param[in] window The receiving window of the channel. The window is the
* maximum size of data that can stay in buffers and
* network.
*
* @param[in] maxpacket The maximum packet size allowed (like MTU).
*
* @param[in] payload The buffer containing additional payload for the query.
*
* @return SSH_OK if successful; SSH_ERROR otherwise.
*/
static int
channel_open(ssh_channel channel,
const char *type,
uint32_t window,
uint32_t maxpacket,
ssh_buffer payload)
{
ssh_session session = channel->session;
int err = SSH_ERROR;
int rc;
switch (channel->state) {
case SSH_CHANNEL_STATE_NOT_OPEN:
break;
case SSH_CHANNEL_STATE_OPENING:
goto pending;
case SSH_CHANNEL_STATE_OPEN:
case SSH_CHANNEL_STATE_CLOSED:
case SSH_CHANNEL_STATE_OPEN_DENIED:
goto end;
default:
ssh_set_error(session, SSH_FATAL, "Bad state in channel_open: %d",
channel->state);
}
channel->local_channel = ssh_channel_new_id(session);
channel->local_maxpacket = maxpacket;
channel->local_window = window;
SSH_LOG(SSH_LOG_DEBUG,
"Creating a channel %" PRIu32 " with %" PRIu32 " window and %" PRIu32 " max packet",
channel->local_channel, window, maxpacket);
rc = ssh_buffer_pack(session->out_buffer,
"bsddd",
SSH2_MSG_CHANNEL_OPEN,
type,
channel->local_channel,
channel->local_window,
channel->local_maxpacket);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
return err;
}
if (payload != NULL) {
if (ssh_buffer_add_buffer(session->out_buffer, payload) < 0) {
ssh_set_error_oom(session);
return err;
}
}
channel->state = SSH_CHANNEL_STATE_OPENING;
if (ssh_packet_send(session) == SSH_ERROR) {
return err;
}
SSH_LOG(SSH_LOG_PACKET,
"Sent a SSH_MSG_CHANNEL_OPEN type %s for channel %" PRIu32,
type, channel->local_channel);
pending:
/* wait until channel is opened by server */
err = ssh_handle_packets_termination(session,
SSH_TIMEOUT_DEFAULT,
ssh_channel_open_termination,
channel);
if (session->session_state == SSH_SESSION_STATE_ERROR) {
err = SSH_ERROR;
}
end:
/* This needs to pass the SSH_AGAIN from the above,
* but needs to catch failed channel states */
if (channel->state == SSH_CHANNEL_STATE_OPEN) {
err = SSH_OK;
} else if (err != SSH_AGAIN) {
/* Messages were handled correctly, but the channel state is invalid */
err = SSH_ERROR;
}
return err;
}
/* return channel with corresponding local id, or NULL if not found */
ssh_channel ssh_channel_from_local(ssh_session session, uint32_t id) {
struct ssh_iterator *it;
ssh_channel channel = NULL;
for (it = ssh_list_get_iterator(session->channels); it != NULL ; it=it->next) {
channel = ssh_iterator_value(ssh_channel, it);
if (channel == NULL) {
continue;
}
if (channel->local_channel == id) {
return channel;
}
}
return NULL;
}
/**
* @internal
* @brief grows the local window and sends a packet to the other party
* @param session SSH session
* @param channel SSH channel
* @return SSH_OK if successful; SSH_ERROR otherwise.
*/
static int grow_window(ssh_session session,
ssh_channel channel)
{
uint32_t used;
uint32_t increment;
int rc;
/* Calculate the increment taking into account what the peer may still send
* (local_window) and what we've already buffered (stdout_buffer and
* stderr_buffer).
*/
used = channel->local_window;
if (channel->stdout_buffer != NULL) {
used += ssh_buffer_get_len(channel->stdout_buffer);
}
if (channel->stderr_buffer != NULL) {
used += ssh_buffer_get_len(channel->stderr_buffer);
}
/* Avoid a negative increment in case the peer sent more than the window allowed */
increment = WINDOW_DEFAULT > used ? WINDOW_DEFAULT - used : 0;
/* Don't grow until we can request at least half a window */
if (increment < (WINDOW_DEFAULT / 2)) {
SSH_LOG(SSH_LOG_DEBUG,
"growing window (channel %" PRIu32 ":%" PRIu32 ") to %" PRIu32 " bytes : not needed (%" PRIu32 " bytes)",
channel->local_channel, channel->remote_channel, WINDOW_DEFAULT,
channel->local_window);
return SSH_OK;
}
rc = ssh_buffer_pack(session->out_buffer,
"bdd",
SSH2_MSG_CHANNEL_WINDOW_ADJUST,
channel->remote_channel,
increment);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
goto error;
}
if (ssh_packet_send(session) == SSH_ERROR) {
goto error;
}
SSH_LOG(SSH_LOG_DEBUG,
"growing window (channel %" PRIu32 ":%" PRIu32 ") by %" PRIu32 " bytes",
channel->local_channel,
channel->remote_channel,
increment);
channel->local_window += increment;
return SSH_OK;
error:
ssh_buffer_reinit(session->out_buffer);
return SSH_ERROR;
}
/**
* @internal
*
* @brief Parse a channel-related packet to resolve it to a ssh_channel.
*
* @param[in] session The current SSH session.
*
* @param[in] packet The buffer to parse packet from. The read pointer will
* be moved after the call.
*
* @return The related ssh_channel, or NULL if the channel is
* unknown or the packet is invalid.
*/
static ssh_channel channel_from_msg(ssh_session session, ssh_buffer packet)
{
ssh_channel channel = NULL;
uint32_t chan;
int rc;
rc = ssh_buffer_unpack(packet,"d",&chan);
if (rc != SSH_OK) {
ssh_set_error(session, SSH_FATAL,
"Getting channel from message: short read");
return NULL;
}
channel = ssh_channel_from_local(session, chan);
if (channel == NULL) {
ssh_set_error(session, SSH_FATAL,
"Server specified invalid channel %" PRIu32,
(uint32_t) chan);
}
return channel;
}
SSH_PACKET_CALLBACK(channel_rcv_change_window) {
ssh_channel channel = NULL;
uint32_t bytes;
int rc;
bool was_empty;
(void)user;
(void)type;
channel = channel_from_msg(session,packet);
if (channel == NULL) {
SSH_LOG(SSH_LOG_FUNCTIONS, "%s", ssh_get_error(session));
}
rc = ssh_buffer_unpack(packet, "d", &bytes);
if (channel == NULL || rc != SSH_OK) {
SSH_LOG(SSH_LOG_PACKET,
"Error getting a window adjust message: invalid packet");
return SSH_PACKET_USED;
}
SSH_LOG(SSH_LOG_DEBUG,
"Adding %" PRIu32 " bytes to channel (%" PRIu32 ":%" PRIu32 ") (from %" PRIu32 " bytes)",
bytes,
channel->local_channel,
channel->remote_channel,
channel->remote_window);
was_empty = channel->remote_window == 0;
channel->remote_window += bytes;
/* Writing to the channel is non-blocking until the receive window is empty.
When the receive window becomes non-zero again, call channel_write_wontblock_function. */
if (was_empty && bytes > 0) {
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_write_wontblock_function,
session,
channel,
channel->remote_window);
}
return SSH_PACKET_USED;
}
/* is_stderr is set to 1 if the data are extended, ie stderr */
SSH_PACKET_CALLBACK(channel_rcv_data)
{
ssh_channel channel = NULL;
ssh_string str = NULL;
ssh_buffer buf = NULL;
void *data = NULL;
uint32_t len;
int extended, is_stderr = 0;
int rest;
(void)user;
if (type == SSH2_MSG_CHANNEL_DATA) {
extended = 0;
} else { /* SSH_MSG_CHANNEL_EXTENDED_DATA */
extended = 1;
}
channel = channel_from_msg(session, packet);
if (channel == NULL) {
SSH_LOG(SSH_LOG_FUNCTIONS, "%s", ssh_get_error(session));
return SSH_PACKET_USED;
}
if (extended) {
uint32_t data_type_code, rc;
rc = ssh_buffer_get_u32(packet, &data_type_code);
if (rc != sizeof(uint32_t)) {
SSH_LOG(SSH_LOG_PACKET,
"Failed to read data type code: rc = %" PRIu32, rc);
return SSH_PACKET_USED;
}
is_stderr = 1;
data_type_code = ntohl(data_type_code);
if (data_type_code != SSH2_EXTENDED_DATA_STDERR) {
SSH_LOG(SSH_LOG_PACKET, "Invalid data type code %" PRIu32 "!",
data_type_code);
}
}
str = ssh_buffer_get_ssh_string(packet);
if (str == NULL) {
SSH_LOG(SSH_LOG_PACKET, "Invalid data packet!");
return SSH_PACKET_USED;
}
len = ssh_string_len(str);
SSH_LOG(SSH_LOG_PACKET,
"Channel receiving %" PRIu32 " bytes data%s (local win=%" PRIu32
" remote win=%" PRIu32 ")",
len,
is_stderr ? " in stderr" : "",
channel->local_window,
channel->remote_window);
if (len > channel->local_window) {
SSH_LOG(SSH_LOG_RARE,
"Data packet too big for our window(%" PRIu32 " vs %" PRIu32 ")",
len,
channel->local_window);
SSH_STRING_FREE(str);
ssh_set_error(session, SSH_FATAL, "Window exceeded");
return SSH_PACKET_USED;
}
data = ssh_string_data(str);
if (channel_default_bufferize(channel, data, len, is_stderr) < 0) {
SSH_STRING_FREE(str);
return SSH_PACKET_USED;
}
channel->local_window -= len;
SSH_LOG(SSH_LOG_PACKET,
"Channel windows are now (local win=%" PRIu32 " remote win=%" PRIu32 ")",
channel->local_window,
channel->remote_window);
SSH_STRING_FREE(str);
if (is_stderr) {
buf = channel->stderr_buffer;
} else {
buf = channel->stdout_buffer;
}
ssh_callbacks_iterate(channel->callbacks,
ssh_channel_callbacks,
channel_data_function) {
if (ssh_buffer_get(buf) == NULL) {
break;
}
rest = ssh_callbacks_iterate_exec(channel_data_function,
channel->session,
channel,
ssh_buffer_get(buf),
ssh_buffer_get_len(buf),
is_stderr);
if (rest > 0) {
int rc;
if (channel->counter != NULL) {
channel->counter->in_bytes += rest;
}
ssh_buffer_pass_bytes(buf, rest);
rc = grow_window(session, channel);
if (rc == SSH_ERROR) {
return -1;
}
}
}
ssh_callbacks_iterate_end();
return SSH_PACKET_USED;
}
SSH_PACKET_CALLBACK(channel_rcv_eof) {
ssh_channel channel = NULL;
(void)user;
(void)type;
channel = channel_from_msg(session,packet);
if (channel == NULL) {
SSH_LOG(SSH_LOG_FUNCTIONS, "%s", ssh_get_error(session));
return SSH_PACKET_USED;
}
SSH_LOG(SSH_LOG_PACKET,
"Received eof on channel (%" PRIu32 ":%" PRIu32 ")",
channel->local_channel,
channel->remote_channel);
/* channel->remote_window = 0; */
channel->remote_eof = 1;
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_eof_function,
channel->session,
channel);
return SSH_PACKET_USED;
}
static bool ssh_channel_has_unread_data(ssh_channel channel)
{
if (channel == NULL) {
return false;
}
if ((channel->stdout_buffer &&
ssh_buffer_get_len(channel->stdout_buffer) > 0) ||
(channel->stderr_buffer &&
ssh_buffer_get_len(channel->stderr_buffer) > 0))
{
return true;
}
return false;
}
SSH_PACKET_CALLBACK(channel_rcv_close)
{
ssh_channel channel = NULL;
(void)user;
(void)type;
channel = channel_from_msg(session,packet);
if (channel == NULL) {
SSH_LOG(SSH_LOG_FUNCTIONS, "%s", ssh_get_error(session));
return SSH_PACKET_USED;
}
SSH_LOG(SSH_LOG_PACKET,
"Received close on channel (%" PRIu32 ":%" PRIu32 ")",
channel->local_channel,
channel->remote_channel);
if (!ssh_channel_has_unread_data(channel)) {
channel->state = SSH_CHANNEL_STATE_CLOSED;
} else {
channel->delayed_close = 1;
}
if (channel->remote_eof == 0) {
SSH_LOG(SSH_LOG_PACKET,
"Remote host not polite enough to send an eof before close");
}
/*
* The remote eof doesn't break things if there was still data into read
* buffer because the eof is ignored until the buffer is empty.
*/
channel->remote_eof = 1;
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_close_function,
channel->session,
channel);
channel->flags |= SSH_CHANNEL_FLAG_CLOSED_REMOTE;
if(channel->flags & SSH_CHANNEL_FLAG_FREED_LOCAL)
ssh_channel_do_free(channel);
return SSH_PACKET_USED;
}
SSH_PACKET_CALLBACK(channel_rcv_request)
{
ssh_channel channel = NULL;
char *request = NULL;
uint8_t want_reply;
int rc;
(void)user;
(void)type;
channel = channel_from_msg(session, packet);
if (channel == NULL) {
SSH_LOG(SSH_LOG_FUNCTIONS, "%s", ssh_get_error(session));
return SSH_PACKET_USED;
}
rc = ssh_buffer_unpack(packet, "sb", &request, &want_reply);
if (rc != SSH_OK) {
SSH_LOG(SSH_LOG_PACKET, "Invalid MSG_CHANNEL_REQUEST");
return SSH_PACKET_USED;
}
if (strcmp(request, "exit-status") == 0) {
SAFE_FREE(request);
rc = ssh_buffer_unpack(packet, "d", &channel->exit.code);
if (rc != SSH_OK) {
SSH_LOG(SSH_LOG_PACKET, "Invalid exit-status packet");
return SSH_PACKET_USED;
}
channel->exit.status = true;
SSH_LOG(SSH_LOG_PACKET,
"received exit-status %u",
channel->exit.code);
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_exit_status_function,
channel->session,
channel,
channel->exit.code);
return SSH_PACKET_USED;
}
if (strcmp(request, "signal") == 0) {
char *sig = NULL;
SAFE_FREE(request);
SSH_LOG(SSH_LOG_PACKET, "received signal");
rc = ssh_buffer_unpack(packet, "s", &sig);
if (rc != SSH_OK) {
SSH_LOG(SSH_LOG_PACKET, "Invalid MSG_CHANNEL_REQUEST");
return SSH_PACKET_USED;
}
SSH_LOG(SSH_LOG_PACKET, "Remote connection sent a signal SIG %s", sig);
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_signal_function,
channel->session,
channel,
sig);
SAFE_FREE(sig);
return SSH_PACKET_USED;
}
if (strcmp(request, "exit-signal") == 0) {
const char *core = "(core dumped)";
char *sig = NULL;
char *errmsg = NULL;
char *lang = NULL;
uint8_t core_dumped;
SAFE_FREE(request);
rc = ssh_buffer_unpack(packet,
"sbss",
&sig, /* signal name */
&core_dumped, /* core dumped */
&errmsg, /* error message */
&lang);
if (rc != SSH_OK) {
SSH_LOG(SSH_LOG_PACKET, "Invalid MSG_CHANNEL_REQUEST");
return SSH_PACKET_USED;
}
if (core_dumped == 0) {
core = "";
}
SSH_LOG(SSH_LOG_PACKET,
"Remote connection closed by signal SIG %s %s",
sig,
core);
ssh_callbacks_execute_list(channel->callbacks,
ssh_channel_callbacks,
channel_exit_signal_function,
channel->session,
channel,
sig,
core_dumped,
errmsg,
lang);
channel->exit.core_dumped = core_dumped;
if (sig != NULL) {
SAFE_FREE(channel->exit.signal);
channel->exit.signal = sig;
}
channel->exit.status = true;
SAFE_FREE(lang);
SAFE_FREE(errmsg);
return SSH_PACKET_USED;
}
if (strcmp(request, "keepalive@openssh.com") == 0) {
SAFE_FREE(request);
SSH_LOG(SSH_LOG_DEBUG, "Responding to Openssh's keepalive");
rc = ssh_buffer_pack(session->out_buffer,
"bd",
SSH2_MSG_CHANNEL_FAILURE,
channel->remote_channel);
if (rc != SSH_OK) {
return SSH_PACKET_USED;
}
ssh_packet_send(session);
return SSH_PACKET_USED;
}
if (strcmp(request, "auth-agent-req@openssh.com") == 0) {
int status;
SAFE_FREE(request);
SSH_LOG(SSH_LOG_DEBUG, "Received an auth-agent-req request");
status = SSH2_MSG_CHANNEL_FAILURE;
ssh_callbacks_iterate (channel->callbacks,
ssh_channel_callbacks,
channel_auth_agent_req_function) {
ssh_callbacks_iterate_exec(channel_auth_agent_req_function,
channel->session,
channel);
/* in lieu of a return value, if the callback exists it's supported
*/
status = SSH2_MSG_CHANNEL_SUCCESS;
break;
}
ssh_callbacks_iterate_end();
if (want_reply) {
rc = ssh_buffer_pack(session->out_buffer,
"bd",
status,
channel->remote_channel);
if (rc != SSH_OK) {
return SSH_PACKET_USED;
}
ssh_packet_send(session);
}
return SSH_PACKET_USED;
}
#ifdef WITH_SERVER
/* If we are here, that means we have a request that is not in the
* understood client requests. That means we need to create a ssh message to
* be passed to the user code handling ssh messages
*/
ssh_message_handle_channel_request(session,
channel,
packet,
request,
want_reply);
#else
SSH_LOG(SSH_LOG_DEBUG, "Unhandled channel request %s", request);
#endif
SAFE_FREE(request);
return SSH_PACKET_USED;
}
/*
* When data has been received from the ssh server, it can be applied to the
* known user function, with help of the callback, or inserted here
*
* FIXME is the window changed?
*/
int channel_default_bufferize(ssh_channel channel,
void *data, uint32_t len,
bool is_stderr)
{
ssh_session session = NULL;
if(channel == NULL) {
return -1;
}
session = channel->session;
if(data == NULL) {
ssh_set_error_invalid(session);
return -1;
}
SSH_LOG(SSH_LOG_PACKET,
"placing %" PRIu32 " bytes into channel buffer (%s)",
len,
is_stderr ? "stderr" : "stdout");