Return process id of openvpn from interactive service to client

PATCH In review Selva Nair 2 participants 6 messages Jun 23, 2016 – Jun 24, 2016

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Selva Nair

author

2016-06-23 02:42 UTC #0 lore raw

PATCH 1/1 Return process id of openvpn from interactive service to client

- The process id is returned as a message formatted in the same manner as error messages from the service to the client: i.e., a three-line message with pid formatted as 0x%08x on line 1, "Process Id" on line 2 and a blank line 3.

This provides a way for service clients to check the status of openvpn and terminate it without needing management interface or exit event. Useful when the interactive service is used from a launch script, or to force-terminate openvpn from the GUI if/when needed.

Signed-off-by Selva Nair <[email protected]...>

---
 src/openvpnserv/interactive.c |   14 ++++++++++++++
 1 file changed, 14 insertions(+)

src/openvpnserv/interactive.c +14 -0

index 2453f17..c80a181 100644
@@ -230,6 +230,18 @@ WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even
   return AsyncPipeOp (write, pipe, data, size, count, events);
 }
 
+static VOID
+ReturnProcessId (HANDLE pipe, DWORD pid, DWORD count, LPHANDLE events)
+{
+  const WCHAR msg[] = L"\nProcess ID\n";
+  WCHAR buf[10 + _countof(msg)]; /* 10 characters for the pid in 0x%08x format */
+
+  /* A 3-line string like an error message but with pid in place of error number */
+  _snwprintf (buf, _countof(buf), L"0x%08x%s", pid, msg);
+  buf[_countof(buf) - 1] = '\0';
+
+  WritePipeAsync (pipe, buf, wcslen (buf) * 2, count, events);
+}
 
 static VOID
 ReturnError (HANDLE pipe, DWORD error, LPCWSTR func, DWORD count, LPHANDLE events)

@@ -1293,6 +1305,8 @@ RunOpenvpn (LPVOID p)
       goto out;
     }
 
+  ReturnProcessId (pipe, proc_info.dwProcessId, 1, &exit_event);
+
   CloseHandleEx (&stdout_write);
   CloseHandleEx (&stdin_read);
   CloseHandleEx (&svc_pipe);

Signature · 1 line

1.7.10.4

Gert Doering

2016-06-23 06:20 UTC #1 lore raw

Hi,

Quoted 9 lines · Selva Nair

- The process id is returned as a message formatted in the same manner as error messages from the service to the client: i.e., a three-line message with pid formatted as 0x%08x on line 1, "Process Id" on line 2 and a blank line 3.
This provides a way for service clients to check the status of openvpn and terminate it without needing management interface or exit event. Useful when the interactive service is used from a launch script, or to force-terminate openvpn from the GUI if/when needed.

How does the GUI currently handle return messages? As in, does this need GUI changes, or is the GUI prepared to handle anything that comes along?

src/openvpnserv/interactive.c WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even · line 244

Quoted 13 lines

src/openvpnserv/interactive.c +12 -0

+static VOID
+ReturnProcessId (HANDLE pipe, DWORD pid, DWORD count, LPHANDLE events)
+{
+  const WCHAR msg[] = L"\nProcess ID\n";
+  WCHAR buf[10 + _countof(msg)]; /* 10 characters for the pid in 0x%08x format */
+
+  /* A 3-line string like an error message but with pid in place of error number */
+  _snwprintf (buf, _countof(buf), L"0x%08x%s", pid, msg);
+  buf[_countof(buf) - 1] = '\0';
+
+  WritePipeAsync (pipe, buf, wcslen (buf) * 2, count, events);
+}

Where does the extra blank line come from? If I'm not all confused (this is before my first cup of tea) this will write

%08x\nProcess ID\n

into the buffer, and not \n\n...

gert

Signature · 4 lines

USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             [email protected]...
fax: +49-89-35655025                        [email protected]...

Selva Nair

author

2016-06-23 14:39 UTC #2 lore raw

Quoted 6 lines · Gert Doering

Quoted 5 lines · Selva Nair
- The process id is returned as a message formatted in the same manner as error messages from the service to the client: i.e., a three-line message with pid formatted as 0x%08x on line 1, "Process Id" on line 2 and a blank line 3.

Quoted 9 lines

Quoted 4 lines
This provides a way for service clients to check the status of openvpn and terminate it without needing management interface or exit event. Useful when the interactive service is used from a launch script, or to force-terminate openvpn from the GUI if/when needed.
How does the GUI currently handle return messages? As in, does this need GUI changes, or is the GUI prepared to handle anything that comes along?

Currently the GUI interpretes two custom error codes (0x2000000 and 0x20000001) and ignores the rest. So it will just a log a message and ignore this one. Unless the PID happens to match one of those two numbers. Though I've never seen PIDs that large.

An alternative is to set error = 0 and pass PID as the second line:

"0x00000000\nPID\Process ID"

where PID may be formatted as 0x%08x. May be that is better?

Quoted 19 lines

src/openvpnserv/interactive.c WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even
Quoted 6 lines
src/openvpnserv/interactive.c +5 -0
+static VOID
+ReturnProcessId (HANDLE pipe, DWORD pid, DWORD count, LPHANDLE events)
+{
+  const WCHAR msg[] = L"\nProcess ID\n";
+  WCHAR buf[10 + _countof(msg)]; /* 10 characters for the pid in 0x%08x
format */
Review
Quoted 2 lines
(quoted diff) +2 -0
+
+  /* A 3-line string like an error message but with pid in place of
error number */
src/openvpnserv/interactive.c WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even · line 244
Quoted 5 lines
src/openvpnserv/interactive.c +5 -0
+  _snwprintf (buf, _countof(buf), L"0x%08x%s", pid, msg);
+  buf[_countof(buf) - 1] = '\0';
+
+  WritePipeAsync (pipe, buf, wcslen (buf) * 2, count, events);
+}
Where does the extra blank line come from? If I'm not all confused (this is before my first cup of tea) this will write

Quoted 3 lines

%08x\nProcess ID\n
into the buffer, and not \n\n...

May be its my terminology of what is a "line", not your tea. The currently used format is NUMBER\nLINE2\nLINE3 so there is no \n at the end of line
3. In the present case that would be "%08x\nProcess ID\n"

Thanks for looking into this.

Selva

Gert Doering

2016-06-23 16:01 UTC #3 lore raw

Hi,

Quoted 9 lines · Selva Nair

Quoted 3 lines
How does the GUI currently handle return messages? As in, does this need GUI changes, or is the GUI prepared to handle anything that comes along?
Currently the GUI interpretes two custom error codes (0x2000000 and 0x20000001) and ignores the rest. So it will just a log a message and ignore this one. Unless the PID happens to match one of those two numbers. Though I've never seen PIDs that large.

Quoted 5 lines

An alternative is to set error = 0 and pass PID as the second line:
"0x00000000\nPID\Process ID"
where PID may be formatted as 0x%08x. May be that is better?

I think this is better - define a convention for "informational messages" (which this could be) and then use it at both ends :-)

Quoted 18 lines

Quoted 18 lines
src/openvpnserv/interactive.c WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even
Quoted 5 lines
src/openvpnserv/interactive.c +5 -0
+static VOID
+ReturnProcessId (HANDLE pipe, DWORD pid, DWORD count, LPHANDLE events)
+{
+  const WCHAR msg[] = L"\nProcess ID\n";
+  WCHAR buf[10 + _countof(msg)]; /* 10 characters for the pid in 0x%08x
format */
Review
Quoted 2 lines
(quoted diff) +2 -0
+
+  /* A 3-line string like an error message but with pid in place of
error number */
src/openvpnserv/interactive.c WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even · line 244
Quoted 5 lines
src/openvpnserv/interactive.c +5 -0
+  _snwprintf (buf, _countof(buf), L"0x%08x%s", pid, msg);
+  buf[_countof(buf) - 1] = '\0';
+
+  WritePipeAsync (pipe, buf, wcslen (buf) * 2, count, events);
+}
Where does the extra blank line come from? If I'm not all confused (this is before my first cup of tea) this will write

Quoted 8 lines

Quoted 3 lines
%08x\nProcess ID\n
into the buffer, and not \n\n...
May be its my terminology of what is a "line", not your tea. The currently used format is NUMBER\nLINE2\nLINE3 so there is no \n at the end of line
3. In the present case that would be "%08x\nProcess ID\n"

Indeed, terminology. For me, a line ends with a "\n" - but it certainly does not *have* to. If service and gui agree on "thee parts, separated by two \n, no trailing \n", this is good enough (and in which case the code does what is expected).

gert

Signature · 4 lines

USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             [email protected]...
fax: +49-89-35655025                        [email protected]...

Selva Nair

author

2016-06-24 02:50 UTC #4 lore raw

PATCH 1/1 Return process id of openvpn from interactive service to client

In reply to Selva Nair

- The process id is returned as a message formatted in the same manner as error messages from the service to the client: i.e., a three-line message with error number formatted as 0x%08x on line 1, followed by the PID in format 0x%08x on line 2 and a description that reads as "Process ID" on line 3. Error number is set to zero to indicate this is an informational message.

v2 changes: format of the message changed as described above.

Signed-off-by Selva Nair <[email protected]...>

---
 src/openvpnserv/interactive.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

src/openvpnserv/interactive.c +17 -0

index 2453f17..ffaa171 100644
@@ -230,6 +230,21 @@ WritePipeAsync (HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE even
   return AsyncPipeOp (write, pipe, data, size, count, events);
 }
 
+static VOID
+ReturnProcessId (HANDLE pipe, DWORD pid, DWORD count, LPHANDLE events)
+{
+  const WCHAR msg[] = L"Process ID";
+  WCHAR buf[22 + _countof(msg)]; /* 10 chars each for error and PID and 2 for line breaks */
+
+  /*
+   * Same format as error messages (3 line string) with error = 0 in
+   * 0x%08x format, PID on line 2 and a description "Process ID" on line 3
+   */
+  _snwprintf (buf, _countof(buf), L"0x%08x\n0x%08x\n%s", 0, pid, msg);
+  buf[_countof(buf) - 1] = '\0';
+
+  WritePipeAsync (pipe, buf, wcslen (buf) * 2, count, events);
+}
 
 static VOID
 ReturnError (HANDLE pipe, DWORD error, LPCWSTR func, DWORD count, LPHANDLE events)

@@ -1293,6 +1308,8 @@ RunOpenvpn (LPVOID p)
       goto out;
     }
 
+  ReturnProcessId (pipe, proc_info.dwProcessId, 1, &exit_event);
+
   CloseHandleEx (&stdout_write);
   CloseHandleEx (&stdin_read);
   CloseHandleEx (&svc_pipe);

Signature · 1 line

1.7.10.4

Gert Doering

2016-06-24 06:30 UTC #5 lore raw

ACK.

Only compile-tested and "stared at code".

Your patch has been applied to the master branch.

commit e4c9bbe6c367132c8570fe747d85a6075ff04245

Author: Selva Nair
Date:   Thu Jun 23 22:50:56 2016 -0400

     Return process id of openvpn from interactive service to client

     Signed-off-by: Selva Nair <[email protected]...>
     Acked-by: Gert Doering <[email protected]...>
     Message-Id: <[email protected]...>
     URL: http://article.gmane.org/gmane.network.openvpn.devel/11984
     Signed-off-by: Gert Doering <[email protected]...>

--
kind regards,

Gert Doering