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/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#include "includes.h"
#include "session.h"
#include "dbutil.h"
#include "packet.h"
#include "algo.h"
#include "buffer.h"
#include "dss.h"
#include "ssh.h"
#include "dbrandom.h"
#include "kex.h"
#include "channel.h"
#include "chansession.h"
#include "atomicio.h"
#include "tcpfwd.h"
#include "service.h"
#include "auth.h"
#include "runopts.h"
#include "crypto_desc.h"
static void svr_remoteclosed();
struct serversession svr_ses; /* GLOBAL */
static const packettype svr_packettypes[] = {
{SSH_MSG_CHANNEL_DATA, recv_msg_channel_data},
{SSH_MSG_CHANNEL_WINDOW_ADJUST, recv_msg_channel_window_adjust},
{SSH_MSG_USERAUTH_REQUEST, recv_msg_userauth_request}, /* server */
{SSH_MSG_SERVICE_REQUEST, recv_msg_service_request}, /* server */
{SSH_MSG_KEXINIT, recv_msg_kexinit},
{SSH_MSG_KEXDH_INIT, recv_msg_kexdh_init}, /* server */
{SSH_MSG_NEWKEYS, recv_msg_newkeys},
{SSH_MSG_GLOBAL_REQUEST, recv_msg_global_request_remotetcp},
{SSH_MSG_CHANNEL_REQUEST, recv_msg_channel_request},
{SSH_MSG_CHANNEL_OPEN, recv_msg_channel_open},
{SSH_MSG_CHANNEL_EOF, recv_msg_channel_eof},
{SSH_MSG_CHANNEL_CLOSE, recv_msg_channel_close},
{SSH_MSG_REQUEST_FAILURE, ignore_recv_msg_request_failure}, /* for keepalive */
#ifdef USING_LISTENERS
{SSH_MSG_CHANNEL_OPEN_CONFIRMATION, recv_msg_channel_open_confirmation},
{SSH_MSG_CHANNEL_OPEN_FAILURE, recv_msg_channel_open_failure},
#endif
{0, 0} /* End */
};
static const struct ChanType *svr_chantypes[] = {
&svrchansess,
#ifdef ENABLE_SVR_LOCALTCPFWD
&svr_chan_tcpdirect,
#endif
NULL /* Null termination is mandatory. */
};
static void
svr_session_cleanup(void)
{
/* free potential public key options */
svr_pubkey_options_cleanup();
}
static void
svr_sessionloop() {
if (svr_ses.connect_time != 0
&& monotonic_now() - svr_ses.connect_time >= AUTH_TIMEOUT) {
dropbear_close("Timeout before auth");
}
}
void svr_session(int sock, int childpipe) {
char *host, *port;
size_t len;
common_session_init(sock, sock);
svr_ses.connect_time = monotonic_now();;
/* Initialise server specific parts of the session */
svr_ses.childpipe = childpipe;
#ifdef USE_VFORK
svr_ses.server_pid = getpid();
#endif
svr_authinitialise();
chaninitialise(svr_chantypes);
svr_chansessinitialise();
/* for logging the remote address */
get_socket_address(ses.sock_in, NULL, NULL, &host, &port, 0);
len = strlen(host) + strlen(port) + 2;
svr_ses.addrstring = m_malloc(len);
snprintf(svr_ses.addrstring, len, "%s:%s", host, port);
m_free(host);
m_free(port);
get_socket_address(ses.sock_in, NULL, NULL,
&svr_ses.remotehost, NULL, 1);
/* set up messages etc */
ses.remoteclosed = svr_remoteclosed;
ses.extra_session_cleanup = svr_session_cleanup;
/* packet handlers */
ses.packettypes = svr_packettypes;
ses.isserver = 1;
/* We're ready to go now */
sessinitdone = 1;
/* exchange identification, version etc */
send_session_identification();
/* start off with key exchange */
send_msg_kexinit();
/* Run the main for loop. NULL is for the dispatcher - only the client
* code makes use of it */
session_loop(svr_sessionloop);
/* Not reached */
}
/* failure exit - format must be <= 100 chars */
void svr_dropbear_exit(int exitcode, const char* format, va_list param) {
char fmtbuf[300];
if (!sessinitdone) {
/* before session init */
snprintf(fmtbuf, sizeof(fmtbuf),
"Early exit: %s", format);
} else if (ses.authstate.authdone) {
/* user has authenticated */
snprintf(fmtbuf, sizeof(fmtbuf),
"Exit (%s): %s",
ses.authstate.pw_name, format);
} else if (ses.authstate.pw_name) {
/* we have a potential user */
snprintf(fmtbuf, sizeof(fmtbuf),
"Exit before auth (user '%s', %d fails): %s",
ses.authstate.pw_name, ses.authstate.failcount, format);
} else {
/* before userauth */
snprintf(fmtbuf, sizeof(fmtbuf),
"Exit before auth: %s", format);
}
_dropbear_log(LOG_INFO, fmtbuf, param);
#ifdef USE_VFORK
/* For uclinux only the main server process should cleanup - we don't want
* forked children doing that */
if (svr_ses.server_pid == getpid())
#endif
{
/* must be after we've done with username etc */
session_cleanup();
}
exit(exitcode);
}
/* priority is priority as with syslog() */
void svr_dropbear_log(int priority, const char* format, va_list param) {
char printbuf[1024];
char datestr[20];
time_t timesec;
int havetrace = 0;
vsnprintf(printbuf, sizeof(printbuf), format, param);
#ifndef DISABLE_SYSLOG
if (svr_opts.usingsyslog) {
syslog(priority, "%s", printbuf);
}
#endif
/* if we are using DEBUG_TRACE, we want to print to stderr even if
* syslog is used, so it is included in error reports */
#ifdef DEBUG_TRACE
havetrace = debug_trace;
#endif
if (!svr_opts.usingsyslog || havetrace)
{
struct tm * local_tm = NULL;
timesec = time(NULL);
local_tm = localtime(×ec);
if (local_tm == NULL
|| strftime(datestr, sizeof(datestr), "%b %d %H:%M:%S",
local_tm) == 0)
{
/* upon failure, just print the epoch-seconds time. */
snprintf(datestr, sizeof(datestr), "%d", (int)timesec);
}
fprintf(stderr, "[%d] %s %s\n", getpid(), datestr, printbuf);
}
}
/* called when the remote side closes the connection */
static void svr_remoteclosed() {
m_close(ses.sock_in);
m_close(ses.sock_out);
ses.sock_in = -1;
ses.sock_out = -1;
dropbear_close("Exited normally");
}
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