sys/src/ape/lib/ap/plan9/fcntl.c

   1 #include "lib.h"
   2 #include <unistd.h>
   3 #include <errno.h>
   4 #include <stdarg.h>
   5 #include "sys9.h"
   6
   7 /*
   8  * BUG: advisory locking not implemented
   9  */
  10
  11 #define OFL (O_ACCMODE|O_NONBLOCK|O_APPEND)
  12
  13 int
  14 fcntl(int fd, int cmd, ...)
  15 {
  16         int arg, i, ans, err;
  17         Fdinfo *fi, *fans;
  18         va_list va;
  19         unsigned long oflags;
  20
  21         err = 0;
  22         ans = 0;
  23         va_start(va, cmd);
  24         arg = va_arg(va, int);
  25         va_end(va);
  26         fi = &_fdinfo[fd];
  27         if(fd<0 || fd>=OPEN_MAX || !(fi->flags&FD_ISOPEN))
  28                 err = EBADF;
  29         else switch(cmd){
  30                 case F_DUPFD:
  31                         if(fi->flags&(FD_BUFFERED|FD_BUFFEREDX)){
  32                                 err = EGREG;    /* dup of buffered fd not implemented */
  33                                 break;
  34                         }
  35                         oflags = fi->oflags;
  36                         for(i = (arg>0)? arg : 0; i<OPEN_MAX; i++)
  37                                 if(!(_fdinfo[i].flags&FD_ISOPEN))
  38                                         break;
  39                         if(i == OPEN_MAX)
  40                                 err = EMFILE;
  41                         else {
  42                                 ans = _DUP(fd, i);
  43                                 if(ans != i){
  44                                         if(ans < 0){
  45                                                 _syserrno();
  46                                                 err = errno;
  47                                         }else
  48                                                 err = EBADF;
  49                                 }else{
  50                                         fans = &_fdinfo[ans];
  51                                         fans->flags = fi->flags&~FD_CLOEXEC;
  52                                         fans->oflags = oflags;
  53                                         fans->uid = fi->uid;
  54                                         fans->gid = fi->gid;
  55                                 }
  56                         }
  57                         break;
  58                 case F_GETFD:
  59                         ans = fi->flags&FD_CLOEXEC;
  60                         break;
  61                 case F_SETFD:
  62                         fi->flags = (fi->flags&~FD_CLOEXEC)|(arg&FD_CLOEXEC);
  63                         break;
  64                 case F_GETFL:
  65                         ans = fi->oflags&OFL;
  66                         break;
  67                 case F_SETFL:
  68                         fi->oflags = (fi->oflags&~OFL)|(arg&OFL);
  69                         break;
  70                 case F_GETLK:
  71                 case F_SETLK:
  72                 case F_SETLKW:
  73                         err = EINVAL;
  74                         break;
  75                 }
  76         if(err){
  77                 errno = err;
  78                 ans = -1;
  79         }
  80         return ans;
  81 }