NAME

       dnet_daemon, dnet_accept, dnet_reject - DECnet daemon functions

SYNOPSIS

       #include <netdnet/dn.h>
       #include <netdnet/dnetdb.h>
       -ldnet -ldnet_daemon -lcrypt

       int dnet_daemon (int object, char *named_object, int verbosity, int do_fork)
       void dnet_accept (int sockfd, short status, char *data, int len)
       void dnet_reject (int sockfd, short status, char *data, int len)

DESCRIPTION

       These  functions are the core of writing a DECnet daemon under Linux. They provide all the
       functionality necessary to have a daemon that will run standalone or be  forked  from  the
       dnetd(8) DECnet super-server. (see dnetd.conf(3) for information on configuring dnetd.
       dnet_daemon()  returns  a connected file descriptor which your daemon program uses to talk
       to the remote client. If your daemon is run from dnetd then this  will  be  it's  standard
       input.
       object is the numbered object which your daemon binds to. Alternatively you can bind to a
       named_object in which case the object number should be zero.
       verbosity  determines how much logging the daemon functions will do. 0 means no logging, 1
       is fairly verbose logging. Anything higher is useful only for debugging.
       do_fork If this is set then, when running standalone, the  daemon  will  fork  and  detach
       itself from the parent process.

       dnet_accept() You MUST call this or dnetd_reject() after receiving a valid file descriptor
       from dnet_daemon. The optional data and status parameters provide extra information to the
       connecting host. See below for status values.

       dnet_reject()  If  you wish to reject the connection for any reason the call this function
       instead of dnet_accept() with the status set to the reason (see below) you  are  rejecting
       the  connection. If your daemon is authenticated by dnetd then connections will already be
       rejected if they are not correctly authorized by either a valid username/password  or  the
       proxy database (see decnet.proxy(3) )
       Here is a list of status codes available in dnetd.conf:

       #define DNSTAT_REJECTED         0 /* Rejected by object */
       #define DNSTAT_RESOURCES        1 /* No resources available */
       #define DNSTAT_NODENAME         2 /* Unrecognised node name */
       #define DNSTAT_LOCNODESHUT      3 /* Local Node is shut down */
       #define DNSTAT_OBJECT           4 /* Unrecognised object */
       #define DNSTAT_OBJNAMEFORMAT    5 /* Invalid object name format */
       #define DNSTAT_TOOBUSY          6 /* Object too busy */
       #define DNSTAT_NODENAMEFORMAT  10 /* Invalid node name format */
       #define DNSTAT_REMNODESHUT     11 /* Remote Node is shut down */
       #define DNSTAT_ACCCONTROL      34 /* Access control rejection */
       #define DNSTAT_NORESPONSE      38 /* No response from object */
       #define DNSTAT_NODEUNREACH     39 /* Node Unreachable */

       /* Disconnect notification errors */
       #define DNSTAT_MANAGEMENT       8 /* Abort by management/third party */
       #define DNSTAT_ABORTOBJECT      9 /* Remote object aborted the link */
       #define DNSTAT_FAILED          38 /* Node or object failed */

       #define DNSTAT_NODERESOURCES   32 /* Node does not have sufficient resources for a new link */
       #define DNSTAT_OBJRESOURCES    33 /* Object does not have sufficient resources for a new link */
       #define DNSTAT_BADACCOUNT      36 /* The Account field in unacceptable */
       #define DNSTAT_TOOLONG         43 /* A field in the access control message was too long */

EXAMPLE

       Here  is  an example MIRROR server. The real mirror server is built into dnetd.  This also
       illustrates the logging functions in libdnetd_daemon.

       #include <sys/types.h>
       #include <sys/socket.h>
       #include <stdarg.h>
       #include <syslog.h>
       #include <netdnet/dnetdb.h>
       #include <netdnet/dn.h>

       int main(int argc, char *argv[])
       {
           int insock;

           /* Set up logging. The parameters are:
            * daemon name to use
            * 's' means log to syslog
            */
           init_daemon_logging("mirror", 's');

           // Wait for something to happen (or check to see if it already has)
           insock = dnet_daemon(DNOBJECT_MIRROR, NULL, 0, 1);

           // Make sure we got a valid socket
           if (insock > -1)
           {
               int readnum;
               char condata[] = {0x00, 0x20}; // Actually 4096 as a LE word
               char ibuf[4096];

               /* We must accept the connection */
               dnet_accept(insock, 0, condata, 2);

               while ( (readnum=read(insock,ibuf,sizeof(ibuf))) > 0)
               {
                   ibuf[0]=0x01;
                   if (write(insock,ibuf,readnum) < 0)
                   {
                       DNETLOG((LOG_WARNING, "mirror, write failed: %m\n"));
                       close(insock);
                       break;
                   }
               }
               close(insock);
           }
           return 0;
       }

       To compile:
       gcc mirror.c -omirror -ldnet -ldnet_daemon -lcrypt

SEE ALSO

       dnetd(8),  dnet_addr(3),  dnet_ntoa(3),  dnet_conn(3),  getnodeadd(3),   getnodebyname(3),
       getnodebyaddr(3), setnodeent(3), decnet.proxy(5)