Move SCP synch calls from sesman tools to library

The sesman tools have some private functions to make syncronous calls
to sesman over SCP. This commit moves these calls to a new module
scp_sync in libipm so that they can be utilised by other parts of
xrdp (i.e. chansrv)

libipm/Makefile.am

@@ -19,6 +19,8 @@ libipm_la_SOURCES = \
   ercp.c \
   scp.h \
   scp.c \
+  scp_sync.h \
+  scp_sync.c \
   scp_application_types.h \
   scp_application_types.c
 

libipm/scp_sync.c

@@ -0,0 +1,168 @@
+/**
+ * xrdp: A Remote Desktop Protocol server.
+ *
+ * Copyright (C) Jay Sorg 2004-2022
+ *
+ * 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 scp_sync.c
+ * @brief scp definitions (synchronous calls)
+ * @author Matt Burt
+ *
+ */
+
+#if defined(HAVE_CONFIG_H)
+#include "config_ac.h"
+#endif
+
+//nclude "tools_common.h"
+//nclude "trans.h"
+#include "os_calls.h"
+#include "log.h"
+#include "scp.h"
+#include "scp_sync.h"
+
+/*****************************************************************************/
+int
+scp_sync_wait_specific(struct trans *t, enum scp_msg_code wait_msgno)
+{
+
+    int rv = 0;
+    int available = 0;
+
+    while (rv == 0 && !available)
+    {
+        if ((rv = scp_msg_in_wait_available(t)) != 0)
+        {
+            LOG(LOG_LEVEL_ERROR, "Error waiting on sesman transport");
+        }
+        else
+        {
+            enum scp_msg_code reply_msgno = scp_msg_in_get_msgno(t);
+
+            available = 1;
+            if (reply_msgno != wait_msgno)
+            {
+                char buff[64];
+                scp_msgno_to_str(reply_msgno, buff, sizeof(buff));
+
+                LOG(LOG_LEVEL_WARNING,
+                    "Ignoring unexpected message %s", buff);
+                scp_msg_in_reset(t);
+                available = 0;
+            }
+        }
+    }
+
+    return rv;
+}
+
+/*****************************************************************************/
+int
+scp_sync_uds_login_request(struct trans *t)
+{
+    int rv = scp_send_uds_login_request(t);
+    if (rv == 0)
+    {
+        if ((rv = scp_sync_wait_specific(t, E_SCP_LOGIN_RESPONSE)) == 0)
+        {
+            enum scp_login_status login_result;
+            int server_closed;
+            rv = scp_get_login_response(t, &login_result, &server_closed, NULL);
+            if (rv == 0 && login_result != E_SCP_LOGIN_OK)
+            {
+                char msg[256];
+                scp_login_status_to_str(login_result, msg, sizeof(msg));
+                g_printf("Login failed; %s\n", msg);
+                rv = 1;
+                if (!server_closed)
+                {
+                    (void)scp_send_close_connection_request(t);
+                }
+            }
+            scp_msg_in_reset(t); // Done with this message
+        }
+
+    }
+    return rv;
+}
+
+/*****************************************************************************/
+struct list *
+scp_sync_list_sessions_request(struct trans *t)
+{
+    struct list *sessions = list_create();
+    if (sessions == NULL)
+    {
+        LOG(LOG_LEVEL_ERROR, "Out of memory for sessions list");
+    }
+    else
+    {
+        int end_of_list = 0;
+
+        enum scp_list_sessions_status status;
+        struct scp_session_info *p;
+
+        int rv = scp_send_list_sessions_request(t);
+
+        sessions->auto_free = 1;
+
+        while (rv == 0 && !end_of_list)
+        {
+            rv = scp_sync_wait_specific(t, E_SCP_LIST_SESSIONS_RESPONSE);
+            if (rv != 0)
+            {
+                break;
+            }
+
+            rv = scp_get_list_sessions_response(t, &status, &p);
+            if (rv != 0)
+            {
+                break;
+            }
+
+            switch (status)
+            {
+                case E_SCP_LS_SESSION_INFO:
+                    if (!list_add_item(sessions, (tintptr)p))
+                    {
+                        g_free(p);
+                        LOG(LOG_LEVEL_ERROR, "Out of memory for session item");
+                        rv = 1;
+                    }
+                    break;
+
+                case E_SCP_LS_END_OF_LIST:
+                    end_of_list = 1;
+                    break;
+
+                default:
+                    LOG(LOG_LEVEL_ERROR,
+                        "Unexpected return code %d for session item", status);
+                    rv = 1;
+            }
+            scp_msg_in_reset(t);
+        }
+
+        if (rv != 0)
+        {
+            list_delete(sessions);
+            sessions = NULL;
+        }
+    }
+
+    return sessions;
+}

libipm/scp_sync.h

@@ -0,0 +1,89 @@
+/**
+ * xrdp: A Remote Desktop Protocol server.
+ *
+ * Copyright (C) Jay Sorg 2004-2022, all xrdp contributors
+ *
+ * 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 libipm/scp_sync.h
+ * @brief scp declarations (synchronous calls)
+ * @author Simone Fedele/ Matt Burt
+ *
+ * This module places a synchronous wrapper on top of some of the
+ * calls in scp.h. It is intended to be used for simple SCP applications
+ * which do not need to handle SCP messages along with other messages
+ * using the xrdp transport mechanism.
+ *
+ */
+
+#ifndef SCP_SYNC_H
+#define SCP_SYNC_H
+
+#include <scp.h>
+
+/**
+ * Waits on a single transport for a specific SCP message to be available for
+ * parsing
+ *
+ * @param trans libipm transport
+ * @param wait_msgno Message number to wait for
+ * @return != 0 for error
+ *
+ * This is a convenience function, used to implement synchronous calls.
+ *
+ * While the call is active, data-in callbacks for the transport are
+ * disabled.
+ *
+ * Unexpected messages are ignored and logged.
+ *
+ * Only use this call if you have nothing to do until a message
+ * arrives on the transport.
+ * - If you have other transports to service, use
+ *   scp_msg_in_check_available()
+ * - If you can process any incoming message, use
+ *   scp_msg_in_wait_available()
+ */
+int
+scp_sync_wait_specific(struct trans *t, enum scp_msg_code wait_msgno);
+
+/**
+ * Send UDS login request to sesman and wait for answer
+ *
+ * @param t SCP transport
+ * @return 0 for successful login
+ *
+ * If non-zero is returned, the scp_connection has been closed (if
+ * appropriate) and simply remains to be deleted.
+ */
+int
+scp_sync_uds_login_request(struct trans *t);
+
+/**
+ * Send list sessions request to sesman and wait for answer(s)
+ *
+ * @param t SCP transport
+ * @return list of sessions
+ *
+ * If NULL is returned, the scp_connection has been closed (if
+ * appropriate) and simply remains to be deleted.
+ *
+ * If NULL is not returned, the caller must call list_delete() to
+ * free it.
+ */
+struct list *
+scp_sync_list_sessions_request(struct trans *t);
+
+#endif /* SCP_SYNC_H */

sesman/tools/Makefile.am

@@ -17,14 +17,10 @@ noinst_PROGRAMS = \
   xrdp-xcon
 
 xrdp_sesrun_SOURCES = \
-  sesrun.c \
+  sesrun.c
-  tools_common.h \
-  tools_common.c
 
 xrdp_sesadmin_SOURCES = \
-  sesadmin.c \
+  sesadmin.c
-  tools_common.h \
-  tools_common.c
 
 xrdp_dis_SOURCES = \
   dis.c

sesman/tools/sesadmin.c

@@ -26,11 +26,14 @@
 #include "log.h"
 #include "os_calls.h"
 #include "string_calls.h"
-#include "tools_common.h"
+
+#include "scp.h"
+#include "scp_sync.h"
 
 #include <stdio.h>
 #include <unistd.h>
 
+
 char cmnd[257];
 char port[257];
 
@@ -89,25 +92,8 @@ int main(int argc, char **argv)
     }
     else
     {
-        enum scp_login_status  login_result;
-
         /* Log in as the current user */
-        if ((rv = scp_send_uds_login_request(t)) == 0 &&
+        rv = scp_sync_uds_login_request(t);
-                (rv = wait_for_sesman_reply(t, E_SCP_LOGIN_RESPONSE)) == 0)
-        {
-            rv = scp_get_login_response(t, &login_result, NULL, NULL);
-            if (rv == 0)
-            {
-                if (login_result != E_SCP_LOGIN_OK)
-                {
-                    char msg[256];
-                    scp_login_status_to_str(login_result, msg, sizeof(msg));
-                    g_printf("Login failed; %s\n", msg);
-                    rv = 1;
-                }
-            }
-            scp_msg_in_reset(t); // Done with this message
-        }
     }
 
     if (rv == 0)
@@ -169,48 +155,9 @@ print_session(const struct scp_session_info *s)
 static int
 cmndList(struct trans *t)
 {
-    struct list *sessions = list_create();
+    int rv = 1;
-    int end_of_list = 0;
+    struct list *sessions = scp_sync_list_sessions_request(t);
-
+    if (sessions != NULL)
-    enum scp_list_sessions_status status;
-    struct scp_session_info *p;
-
-    int rv = scp_send_list_sessions_request(t);
-
-    sessions->auto_free = 1;
-
-    while (rv == 0 && !end_of_list)
-    {
-        rv = wait_for_sesman_reply(t, E_SCP_LIST_SESSIONS_RESPONSE);
-        if (rv != 0)
-        {
-            break;
-        }
-
-        rv = scp_get_list_sessions_response(t, &status, &p);
-        if (rv != 0)
-        {
-            break;
-        }
-
-        switch (status)
-        {
-            case E_SCP_LS_SESSION_INFO:
-                list_add_item(sessions, (tintptr)p);
-                break;
-
-            case E_SCP_LS_END_OF_LIST:
-                end_of_list = 1;
-                break;
-
-            default:
-                printf("Unexpected return code %d\n", status);
-                rv = 1;
-        }
-        scp_msg_in_reset(t);
-    }
-
-    if (rv == 0)
     {
         if (sessions->count == 0)
         {
@@ -224,9 +171,10 @@ cmndList(struct trans *t)
                 print_session((struct scp_session_info *)sessions->items[i]);
             }
         }
+        (void)scp_send_close_connection_request(t);
+        list_delete(sessions);
     }
 
-    list_delete(sessions);
     return rv;
 }
 

sesman/tools/sesrun.c

@@ -40,7 +40,8 @@
 #include "string_calls.h"
 #include "guid.h"
 
-#include "tools_common.h"
+#include "scp.h"
+#include "scp_sync.h"
 
 // cppcheck doesn't always set this macro to something in double-quotes
 #if defined(__cppcheck__)
@@ -453,7 +454,7 @@ handle_login_response(struct trans *t, int *server_closed)
 {
     enum scp_login_status login_result;
 
-    int rv = wait_for_sesman_reply(t, E_SCP_LOGIN_RESPONSE);
+    int rv = scp_sync_wait_specific(t, E_SCP_LOGIN_RESPONSE);
     if (rv != 0)
     {
         *server_closed = 1;
@@ -511,7 +512,7 @@ handle_create_session_response(struct trans *t)
     int display;
     struct guid guid;
 
-    int rv = wait_for_sesman_reply(t, E_SCP_CREATE_SESSION_RESPONSE);
+    int rv = scp_sync_wait_specific(t, E_SCP_CREATE_SESSION_RESPONSE);
     if (rv == 0)
     {
         rv = scp_get_create_session_response(t, &status,

sesman/tools/tools_common.c

@@ -1,71 +0,0 @@
-/**
- * xrdp: A Remote Desktop Protocol server.
- *
- * Copyright (C) Jay Sorg 2004-2022
- *
- * 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 tools_common.c
- * @brief Common definitions for the tools utilities
- * @author Matt Burt
- *
- */
-
-
-#if defined(HAVE_CONFIG_H)
-#include "config_ac.h"
-#endif
-
-#include "tools_common.h"
-#include "trans.h"
-#include "os_calls.h"
-#include "scp.h"
-
-
-/*****************************************************************************/
-int
-wait_for_sesman_reply(struct trans *t, enum scp_msg_code wait_msgno)
-{
-
-    int rv = 0;
-    int available = 0;
-
-    while (rv == 0 && !available)
-    {
-        if ((rv = scp_msg_in_wait_available(t)) != 0)
-        {
-            LOG(LOG_LEVEL_ERROR, "Error waiting on sesman transport");
-        }
-        else
-        {
-            enum scp_msg_code reply_msgno = scp_msg_in_get_msgno(t);
-
-            available = 1;
-            if (reply_msgno != wait_msgno)
-            {
-                char buff[64];
-                scp_msgno_to_str(reply_msgno, buff, sizeof(buff));
-
-                LOG(LOG_LEVEL_WARNING,
-                    "Ignoring unexpected message %s", buff);
-                scp_msg_in_reset(t);
-                available = 0;
-            }
-        }
-    }
-
-    return rv;
-}

sesman/tools/tools_common.h

@@ -1,48 +0,0 @@
-/**
- * xrdp: A Remote Desktop Protocol server.
- *
- * Copyright (C) Jay Sorg 2004-2022
- *
- * 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 tools_common.c
- * @brief Common definitions for the tools utilities
- * @author Matt Burt
- *
- */
-
-#if !defined(TOOLS_COMMON_H)
-#define TOOLS_COMMON_H
-
-#include "scp.h"
-
-struct trans;
-
-/**************************************************************************//**
- * Waits for an expected reply from sesman
- *
- * Any other incoming messages are ignored.
- *
- * Following this call, the message can be parsed in the usual way.
- *
- * @param t SCP transport
- * @param wait_msgno Code of the message we're waiting for.
- * @result 0 for success
- */
-int
-wait_for_sesman_reply(struct trans *t, enum scp_msg_code wait_msgno);
-
-#endif /* TOOLS_COMMON_H */