xrdp/sesman/libscp/libscp_v1s_mng.c
Ben Cohen c7d08bd9e7 xrdp-sesadmin: fix error when there are no sessions
Test case:  On a system running xrdp with no sessions running run:

  xrdp-sesadmin -u=<user> -p=<password> -c=list

Expected result: "No sessions." (ignoring debug output)
Observed result: "Error getting session list."

In the SCP_SERVER_STATE_MNG_LISTREQ case in scp_v1_mng_process() if
there are no sessions it ends the scp session, which causes an error in
the client.  In commit 0017081d the client was changed to report errors,
giving the result above.

Fix by calling scp_v1s_mng_list_sessions() from scp_v1_mng_process()
even when there are no sessions, and if so sending a packet with a count
of zero so that the client gets what it expects.
2017-07-06 13:40:25 +09:00

366 lines
9.7 KiB
C

/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2004-2012
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
*
* @file libscp_v1s_mng.c
* @brief libscp version 1 server api code - session management
* @author Simone Fedele
*
*/
#if defined(HAVE_CONFIG_H)
#include <config_ac.h>
#endif
#ifndef LIBSCP_V1S_MNG_C
#define LIBSCP_V1S_MNG_C
#include "libscp_v1s_mng.h"
//extern struct log_config* s_log;
static enum SCP_SERVER_STATES_E
_scp_v1s_mng_check_response(struct SCP_CONNECTION *c, struct SCP_SESSION *s);
/* server API */
enum SCP_SERVER_STATES_E
scp_v1s_mng_accept(struct SCP_CONNECTION *c, struct SCP_SESSION **s)
{
struct SCP_SESSION *session;
tui32 ipaddr;
tui16 cmd;
tui8 sz;
char buf[257];
/* reading command */
in_uint16_be(c->in_s, cmd);
if (cmd != 1) /* manager login */
{
return SCP_SERVER_STATE_SEQUENCE_ERR;
}
session = scp_session_create();
if (0 == session)
{
return SCP_SERVER_STATE_INTERNAL_ERR;
}
scp_session_set_version(session, 1);
scp_session_set_type(session, SCP_SESSION_TYPE_MANAGE);
/* reading username */
in_uint8(c->in_s, sz);
buf[sz] = '\0';
in_uint8a(c->in_s, buf, sz);
if (0 != scp_session_set_username(session, buf))
{
scp_session_destroy(session);
return SCP_SERVER_STATE_INTERNAL_ERR;
}
/* reading password */
in_uint8(c->in_s, sz);
buf[sz] = '\0';
in_uint8a(c->in_s, buf, sz);
if (0 != scp_session_set_password(session, buf))
{
scp_session_destroy(session);
return SCP_SERVER_STATE_INTERNAL_ERR;
}
/* reading remote address */
in_uint8(c->in_s, sz);
if (sz == SCP_ADDRESS_TYPE_IPV4)
{
in_uint32_be(c->in_s, ipaddr);
scp_session_set_addr(session, sz, &ipaddr);
}
else if (sz == SCP_ADDRESS_TYPE_IPV6)
{
in_uint8a(c->in_s, buf, 16);
scp_session_set_addr(session, sz, buf);
}
/* reading hostname */
in_uint8(c->in_s, sz);
buf[sz] = '\0';
in_uint8a(c->in_s, buf, sz);
if (0 != scp_session_set_hostname(session, buf))
{
scp_session_destroy(session);
return SCP_SERVER_STATE_INTERNAL_ERR;
}
/* returning the struct */
(*s) = session;
return SCP_SERVER_STATE_START_MANAGE;
}
/* 002 */
enum SCP_SERVER_STATES_E
scp_v1s_mng_allow_connection(struct SCP_CONNECTION *c, struct SCP_SESSION *s)
{
init_stream(c->out_s, c->out_s->size);
out_uint32_be(c->out_s, 1);
/* packet size: 4 + 4 + 2 + 2 */
/* version + size + cmdset + cmd */
out_uint32_be(c->out_s, 12);
out_uint16_be(c->out_s, SCP_COMMAND_SET_MANAGE);
out_uint16_be(c->out_s, SCP_CMD_MNG_LOGIN_ALLOW);
if (0 != scp_tcp_force_send(c->in_sck, c->out_s->data, 12))
{
return SCP_SERVER_STATE_NETWORK_ERR;
}
return _scp_v1s_mng_check_response(c, s);
}
/* 003 */
enum SCP_SERVER_STATES_E
scp_v1s_mng_deny_connection(struct SCP_CONNECTION *c, const char *reason)
{
int rlen;
init_stream(c->out_s, c->out_s->size);
/* forcing message not to exceed 64k */
rlen = g_strlen(reason);
if (rlen > 65535)
{
rlen = 65535;
}
out_uint32_be(c->out_s, 1);
/* packet size: 4 + 4 + 2 + 2 + 2 + strlen(reason)*/
/* version + size + cmdset + cmd + msglen + msg */
out_uint32_be(c->out_s, rlen + 14);
out_uint16_be(c->out_s, SCP_COMMAND_SET_MANAGE);
out_uint16_be(c->out_s, SCP_CMD_MNG_LOGIN_DENY);
out_uint16_be(c->out_s, rlen);
out_uint8p(c->out_s, reason, rlen);
if (0 != scp_tcp_force_send(c->in_sck, c->out_s->data, rlen + 14))
{
return SCP_SERVER_STATE_NETWORK_ERR;
}
return SCP_SERVER_STATE_END;
}
/* 006 */
enum SCP_SERVER_STATES_E
scp_v1s_mng_list_sessions(struct SCP_CONNECTION *c, struct SCP_SESSION *s,
int sescnt, struct SCP_DISCONNECTED_SESSION *ds)
{
tui32 version = 1;
tui32 size = 12;
tui16 cmd = SCP_CMD_MNG_LIST;
int pktcnt;
int idx;
int sidx;
int pidx;
struct SCP_DISCONNECTED_SESSION *cds;
/* calculating the number of packets to send */
if (sescnt == 0)
{
pktcnt = 1;
}
else
{
pktcnt = sescnt / SCP_SERVER_MAX_LIST_SIZE;
if ((sescnt % SCP_SERVER_MAX_LIST_SIZE) != 0)
{
pktcnt++;
}
}
for (idx = 0; idx < pktcnt; idx++)
{
/* ok, we send session session list */
init_stream(c->out_s, c->out_s->size);
/* size: ver+size+cmdset+cmd+sescnt+continue+count */
size = 4 + 4 + 2 + 2 + 4 + 1 + 1;
/* header */
s_push_layer(c->out_s, channel_hdr, 8);
out_uint16_be(c->out_s, SCP_COMMAND_SET_MANAGE);
out_uint16_be(c->out_s, cmd);
/* session count */
out_uint32_be(c->out_s, sescnt);
/* setting the continue flag */
if ((idx + 1)*SCP_SERVER_MAX_LIST_SIZE >= sescnt)
{
out_uint8(c->out_s, 0);
/* setting session count for this packet */
pidx = sescnt - (idx * SCP_SERVER_MAX_LIST_SIZE);
out_uint8(c->out_s, pidx);
}
else
{
out_uint8(c->out_s, 1);
/* setting session count for this packet */
pidx = SCP_SERVER_MAX_LIST_SIZE;
out_uint8(c->out_s, pidx);
}
/* adding session descriptors */
for (sidx = 0; sidx < pidx; sidx++)
{
/* shortcut to the current session to send */
cds = ds + ((idx) * SCP_SERVER_MAX_LIST_SIZE) + sidx;
/* session data */
out_uint32_be(c->out_s, cds->SID); /* session id */
out_uint8(c->out_s, cds->type);
out_uint16_be(c->out_s, cds->height);
out_uint16_be(c->out_s, cds->width);
out_uint8(c->out_s, cds->bpp);
out_uint8(c->out_s, cds->idle_days);
out_uint8(c->out_s, cds->idle_hours);
out_uint8(c->out_s, cds->idle_minutes);
size += 13;
out_uint16_be(c->out_s, cds->conn_year);
out_uint8(c->out_s, cds->conn_month);
out_uint8(c->out_s, cds->conn_day);
out_uint8(c->out_s, cds->conn_hour);
out_uint8(c->out_s, cds->conn_minute);
out_uint8(c->out_s, cds->addr_type);
size += 7;
if (cds->addr_type == SCP_ADDRESS_TYPE_IPV4)
{
in_uint32_be(c->out_s, cds->ipv4addr);
size += 4;
}
else if (cds->addr_type == SCP_ADDRESS_TYPE_IPV6)
{
in_uint8a(c->out_s, cds->ipv6addr, 16);
size += 16;
}
}
s_pop_layer(c->out_s, channel_hdr);
out_uint32_be(c->out_s, version);
out_uint32_be(c->out_s, size);
if (0 != scp_tcp_force_send(c->in_sck, c->out_s->data, size))
{
log_message(LOG_LEVEL_WARNING, "[v1s_mng:%d] connection aborted: network error", __LINE__);
return SCP_SERVER_STATE_NETWORK_ERR;
}
}
return _scp_v1s_mng_check_response(c, s);
}
static enum SCP_SERVER_STATES_E
_scp_v1s_mng_check_response(struct SCP_CONNECTION *c, struct SCP_SESSION *s)
{
tui32 version;
tui32 size;
tui16 cmd;
// tui8 dim;
// char buf[257];
init_stream(c->in_s, c->in_s->size);
if (0 != scp_tcp_force_recv(c->in_sck, c->in_s->data, 8))
{
log_message(LOG_LEVEL_WARNING, "[v1s_mng:%d] connection aborted: network error", __LINE__);
return SCP_SERVER_STATE_NETWORK_ERR;
}
in_uint32_be(c->in_s, version);
if (version != 1)
{
log_message(LOG_LEVEL_WARNING, "[v1s_mng:%d] connection aborted: version error", __LINE__);
return SCP_SERVER_STATE_VERSION_ERR;
}
in_uint32_be(c->in_s, size);
init_stream(c->in_s, c->in_s->size);
/* read the rest of the packet */
if (0 != scp_tcp_force_recv(c->in_sck, c->in_s->data, size - 8))
{
log_message(LOG_LEVEL_WARNING, "[v1s_mng:%d] connection aborted: network error", __LINE__);
return SCP_SERVER_STATE_NETWORK_ERR;
}
in_uint16_be(c->in_s, cmd);
if (cmd != SCP_COMMAND_SET_MANAGE)
{
log_message(LOG_LEVEL_WARNING, "[v1s_mng:%d] connection aborted: sequence error", __LINE__);
return SCP_SERVER_STATE_SEQUENCE_ERR;
}
in_uint16_be(c->in_s, cmd);
if (cmd == SCP_CMD_MNG_LIST_REQ) /* request session list */
{
log_message(LOG_LEVEL_INFO, "[v1s_mng:%d] request session list", __LINE__);
return SCP_SERVER_STATE_MNG_LISTREQ;
}
else if (cmd == SCP_CMD_MNG_ACTION) /* execute an action */
{
/*in_uint8(c->in_s, dim);
buf[dim]='\0';
in_uint8a(c->in_s, buf, dim);
scp_session_set_errstr(s, buf);*/
log_message(LOG_LEVEL_INFO, "[v1s_mng:%d] action request", __LINE__);
return SCP_SERVER_STATE_MNG_ACTION;
}
/* else if (cmd == 20) / * password change * /
{
in_uint16_be(c->in_s, s->display);
return SCP_SERVER_STATE_OK;
}
else if (cmd == 40) / * session list * /
{
return SCP_SERVER_STATE_SESSION_LIST;
}*/
log_message(LOG_LEVEL_WARNING, "[v1s_mng:%d] connection aborted: sequence error", __LINE__);
return SCP_SERVER_STATE_SEQUENCE_ERR;
}
#endif