servers/pm/getset.c

   1 /* This file handles the 4 system calls that get and set uids and gids.
   2  * It also handles getpid(), setsid(), and getpgrp().  The code for each
   3  * one is so tiny that it hardly seemed worthwhile to make each a separate
   4  * function.
   5  */
   6
   7 #include "pm.h"
   8 #include <minix/callnr.h>
   9 #include <minix/endpoint.h>
  10 #include <signal.h>
  11 #include "mproc.h"
  12 #include "param.h"
  13
  14 /*===========================================================================*
  15  *                              do_getset                                    *
  16  *===========================================================================*/
  17 PUBLIC int do_getset()
  18 {
  19 /* Handle GETUID, GETGID, GETPID, GETPGRP, SETUID, SETGID, SETSID.  The four
  20  * GETs and SETSID return their primary results in 'r'.  GETUID, GETGID, and
  21  * GETPID also return secondary results (the effective IDs, or the parent
  22  * process ID) in 'reply_res2', which is returned to the user.
  23  */
  24
  25   register struct mproc *rmp = mp;
  26   int r, proc;
  27
  28   switch(call_nr) {
  29         case GETUID:
  30                 r = rmp->mp_realuid;
  31                 rmp->mp_reply.reply_res2 = rmp->mp_effuid;
  32                 break;
  33
  34         case GETGID:
  35                 r = rmp->mp_realgid;
  36                 rmp->mp_reply.reply_res2 = rmp->mp_effgid;
  37                 break;
  38
  39         case GETPID:
  40                 r = mproc[who_p].mp_pid;
  41                 rmp->mp_reply.reply_res2 = mproc[rmp->mp_parent].mp_pid;
  42                 if(pm_isokendpt(m_in.endpt, &proc) == OK && proc >= 0)
  43                         rmp->mp_reply.reply_res3 = mproc[proc].mp_pid;
  44                 break;
  45
  46         case SETEUID:
  47         case SETUID:
  48                 if (rmp->mp_realuid != (uid_t) m_in.usr_id &&
  49                                 rmp->mp_effuid != SUPER_USER)
  50                         return(EPERM);
  51                 if(call_nr == SETUID) rmp->mp_realuid = (uid_t) m_in.usr_id;
  52                 rmp->mp_effuid = (uid_t) m_in.usr_id;
  53
  54                 if (rmp->mp_fs_call != PM_IDLE)
  55                 {
  56                         panic(__FILE__, "do_getset: not idle",
  57                                 rmp->mp_fs_call);
  58                 }
  59                 rmp->mp_fs_call= PM_SETUID;
  60                 r= notify(FS_PROC_NR);
  61                 if (r != OK)
  62                         panic(__FILE__, "do_getset: unable to notify FS", r);
  63
  64                 /* Do not reply until FS is ready to process the setuid
  65                  * request
  66                  */
  67                 r= SUSPEND;
  68                 break;
  69
  70         case SETEGID:
  71         case SETGID:
  72                 if (rmp->mp_realgid != (gid_t) m_in.grp_id &&
  73                                 rmp->mp_effuid != SUPER_USER)
  74                         return(EPERM);
  75                 if(call_nr == SETGID) rmp->mp_realgid = (gid_t) m_in.grp_id;
  76                 rmp->mp_effgid = (gid_t) m_in.grp_id;
  77
  78                 if (rmp->mp_fs_call != PM_IDLE)
  79                 {
  80                         panic(__FILE__, "do_getset: not idle",
  81                                 rmp->mp_fs_call);
  82                 }
  83                 rmp->mp_fs_call= PM_SETGID;
  84                 r= notify(FS_PROC_NR);
  85                 if (r != OK)
  86                         panic(__FILE__, "do_getset: unable to notify FS", r);
  87
  88                 /* Do not reply until FS is ready to process the setgid
  89                  * request
  90                  */
  91                 r= SUSPEND;
  92                 break;
  93
  94         case SETSID:
  95                 if (rmp->mp_procgrp == rmp->mp_pid) return(EPERM);
  96                 rmp->mp_procgrp = rmp->mp_pid;
  97
  98                 if (rmp->mp_fs_call != PM_IDLE)
  99                 {
 100                         panic(__FILE__, "do_getset: not idle",
 101                                 rmp->mp_fs_call);
 102                 }
 103                 rmp->mp_fs_call= PM_SETSID;
 104                 r= notify(FS_PROC_NR);
 105                 if (r != OK)
 106                         panic(__FILE__, "do_getset: unable to notify FS", r);
 107
 108                 /* Do not reply until FS is ready to process the setsid
 109                  * request
 110                  */
 111                 r= SUSPEND;
 112                 break;
 113
 114         case GETPGRP:
 115                 r = rmp->mp_procgrp;
 116                 break;
 117
 118         default:
 119                 r = EINVAL;
 120                 break;
 121   }
 122   return(r);
 123 }