ConnectFlags(), ConnectFlags_r()

Updated: October 26, 2022

Modify or query the flags associated with a connection


#include <sys/neutrino.h>

int ConnectFlags( pid_t pid,
                  int coid, 
                  unsigned mask, 
                  unsigned bits );

int ConnectFlags_r( pid_t pid,
                    int coid, 
                    unsigned mask, 
                    unsigned bits );


The ID of the process that the connection ID belongs to, or 0 for the current process.
The ID of the connection whose flags you want to modify.
A bitmap that indicates which bits are to be modified in the flags. The bits currently defined include:
  • _NTO_COF_CLOEXEC — close the connection if the process calls an exec*() function to start a new process.
  • _NTO_COF_INSECURE (QNX Neutrino 6.6 or later) — mark the connection as insecure. The kernel sets this flag on a connection if the client program replaces its process image (e.g., by calling exec*()) with a setuid or setgid binary. If this flag is set on a connection, calls to MsgDeliverEvent() with an event type of SIGEV_MEMORY or SIGEV_THREAD fail with an error of EACCES.

    In QNX Neutrino 7.0 and later, the server or client can set this flag if it doesn't trust the program at the other end of the connection, but only the kernel can clear it. Currently the flag stays set until the connection is detached.

  • _NTO_COF_NOEVENT (QNX Neutrino 7.0 or later) — prevent the server from sending sigevents over the channel to the client. Only the client can clear this bit.
  • _NTO_COF_NOSHARE (QNX Neutrino 7.1 or later) — this is an internal flag.
  • _NTO_COF_REG_EVENTS (QNX Neutrino 7.0.1 or later; you can use ConnectFlags() to set it in QNX Neutrino 7.1 or later) — reject the delivery of any sigevents that weren't registered as secure events with MsgRegisterEvent().
The new value of the flags.



Use the -l c option to qcc to link against this library. This library is usually included automatically.


The ConnectFlags() and ConnectFlags_r() kernel calls modify or query the flags associated with the specified connection. These kernel calls don't block.

These functions are identical except in the way they indicate errors. See the Returns section for details.

You need to initialize the bits that correspond to the flag in both the mask and bits arguments:

  • In order to change the connection flags on a coid for another process with a different user ID, your process must have the PROCMGR_AID_CONNECTION ability enabled.
  • In order to request information about another process, your process must have the PROCMGR_AID_XPROCESS_QUERY ability enabled.

For more information, see procmgr_ability().


The previous value of the flags associated with the connection.

Note: This value includes only the _NTO_COF_* bits listed above.

If an error occurs:


The coid isn't a valid connection ID for the process.
The mask includes invalid bits.
The calling process doesn't have the required permission; see procmgr_ability().
The process ID is invalid.


QNX Neutrino

Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes