svr-session.c - third_party/dropbear - Git at Google

 /*
  * 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(void);

 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_CHANNEL_SUCCESS, ignore_recv_response},
 	{SSH_MSG_CHANNEL_FAILURE, ignore_recv_response},
 	{SSH_MSG_REQUEST_FAILURE, ignore_recv_response}, /* for keepalive */
 	{SSH_MSG_REQUEST_SUCCESS, ignore_recv_response}, /* client */
 #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();

 	m_free(svr_ses.addrstring);
 	m_free(svr_ses.remotehost);
 	m_free(svr_ses.childpids);
 	svr_ses.childpidsize = 0;
 }

 void svr_session(int sock, int childpipe) {
 	char *host, *port;
 	size_t len;

 	common_session_init(sock, sock);

 	/* 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();

 	kexfirstinitialise(); /* initialise the kex state */

 	/* 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(NULL);

 	/* Not reached */

 }

 /* failure exit - format must be <= 100 chars */
 void svr_dropbear_exit(int exitcode, const char* format, va_list param) {
 	char exitmsg[150];
 	char fullmsg[300];
 	int i;

 	/* Render the formatted exit message */
 	vsnprintf(exitmsg, sizeof(exitmsg), format, param);

 	/* Add the prefix depending on session/auth state */
 	if (!sessinitdone) {
 		/* before session init */
 		snprintf(fullmsg, sizeof(fullmsg), "Early exit: %s", exitmsg);
 	} else if (ses.authstate.authdone) {
 		/* user has authenticated */
 		snprintf(fullmsg, sizeof(fullmsg),
 				"Exit (%s): %s",
 				ses.authstate.pw_name, exitmsg);
 	} else if (ses.authstate.pw_name) {
 		/* we have a potential user */
 		snprintf(fullmsg, sizeof(fullmsg),
 				"Exit before auth (user '%s', %u fails): %s",
 				ses.authstate.pw_name, ses.authstate.failcount, exitmsg);
 	} else {
 		/* before userauth */
 		snprintf(fullmsg, sizeof(fullmsg), "Exit before auth: %s", exitmsg);
 	}

 	dropbear_log(LOG_INFO, "%s", fullmsg);

 #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();
 	}

 	if (svr_opts.hostkey) {
 		sign_key_free(svr_opts.hostkey);
 		svr_opts.hostkey = NULL;
 	}
 	for (i = 0; i < DROPBEAR_MAX_PORTS; i++) {
 		m_free(svr_opts.addresses[i]);
 		m_free(svr_opts.ports[i]);
 	}

 	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 (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 (!opts.usingsyslog || havetrace) {
 		struct tm * local_tm = NULL;
 		timesec = time(NULL);
 		local_tm = localtime(&timesec);
 		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");

 }
	/*
	* 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(void);

	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_CHANNEL_SUCCESS, ignore_recv_response},
	{SSH_MSG_CHANNEL_FAILURE, ignore_recv_response},
	{SSH_MSG_REQUEST_FAILURE, ignore_recv_response}, /* for keepalive */
	{SSH_MSG_REQUEST_SUCCESS, ignore_recv_response}, /* client */
	#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();

	m_free(svr_ses.addrstring);
	m_free(svr_ses.remotehost);
	m_free(svr_ses.childpids);
	svr_ses.childpidsize = 0;
	}

	void svr_session(int sock, int childpipe) {
	char host, port;
	size_t len;

	common_session_init(sock, sock);

	/* 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();

	kexfirstinitialise(); /* initialise the kex state */

	/* 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(NULL);

	/* Not reached */

	}

	/* failure exit - format must be <= 100 chars */
	void svr_dropbear_exit(int exitcode, const char* format, va_list param) {
	char exitmsg[150];
	char fullmsg[300];
	int i;

	/* Render the formatted exit message */
	vsnprintf(exitmsg, sizeof(exitmsg), format, param);

	/* Add the prefix depending on session/auth state */
	if (!sessinitdone) {
	/* before session init */
	snprintf(fullmsg, sizeof(fullmsg), "Early exit: %s", exitmsg);
	} else if (ses.authstate.authdone) {
	/* user has authenticated */
	snprintf(fullmsg, sizeof(fullmsg),
	"Exit (%s): %s",
	ses.authstate.pw_name, exitmsg);
	} else if (ses.authstate.pw_name) {
	/* we have a potential user */
	snprintf(fullmsg, sizeof(fullmsg),
	"Exit before auth (user '%s', %u fails): %s",
	ses.authstate.pw_name, ses.authstate.failcount, exitmsg);
	} else {
	/* before userauth */
	snprintf(fullmsg, sizeof(fullmsg), "Exit before auth: %s", exitmsg);
	}

	dropbear_log(LOG_INFO, "%s", fullmsg);

	#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();
	}

	if (svr_opts.hostkey) {
	sign_key_free(svr_opts.hostkey);
	svr_opts.hostkey = NULL;
	}
	for (i = 0; i < DROPBEAR_MAX_PORTS; i++) {
	m_free(svr_opts.addresses[i]);
	m_free(svr_opts.ports[i]);
	}

	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 (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 (!opts.usingsyslog \|\| havetrace) {
	struct tm * local_tm = NULL;
	timesec = time(NULL);
	local_tm = localtime(&timesec);
	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");

	}