# + tak sie kompiluje:
# tclkit ~/tcl/kit/critcl.kit -lib sockopt_lib.tcl
# + dostarczane cmd, 31.01.2021
# fileno, setsockopt_tos, getsockopt_tos
# + tcl api docs; Tcl_GetChannel i Tcl_GetChannelHandle
# http://www.tcl.tk/man/tcl8.6/TclLib/OpenFileChnl.htm
# http://www.tcl.tk/man/tcl8.6/TclLib/CrtChannel.htm
#
package re critcl
critcl::ccode {
#include <sys/types.h>
#include <sys/socket.h>
//#include <linux/in.h>
#include <linux/ip.h>
#include <netinet/in.h>
//#include <netinet/ip.h>
#include <errno.h>
}
critcl::cproc fileno {Tcl_Interp* in char* str} int {
  Tcl_Channel ch; int desc, err;
  ch=Tcl_GetChannel(in, str, 0);
  if (ch==0) {return -1;}
  err=Tcl_GetChannelHandle(ch, TCL_READABLE , &desc);
  if (err!=TCL_OK) {err=Tcl_GetChannelHandle(ch, TCL_WRITABLE , &desc); }
  if (err!=TCL_OK) {return -1;}
  return desc;
}
critcl::cproc getsockopt_tos {Tcl_Interp* in int desk} int {
  int buf=0, ret=0, len;
  len=sizeof(buf);
  ret=getsockopt(desk, IPPROTO_IP, IP_TOS, (void*)&buf, (void*)&len);
  if (ret==-1) {buf=-1; perror("critcl/getsockopt");}
  return buf;
}
critcl::cproc setsockopt_tos {Tcl_Interp* in int desk int val} int {
  int ret,ret2=0; char b=val;
  ret=setsockopt(desk, IPPROTO_IP, IP_TOS, (const void*)&b, sizeof(b));
  if (ret==-1) {ret2=errno; perror("critcl/setsockopt");}
  return ret2;
}