servers/pm/getset.c

   1 /* This file handles the 6 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 <limits.h>
  11 #include <minix/com.h>
  12 #include <signal.h>
  13 #include "mproc.h"
  14 #include "param.h"
  15
  16 /*===========================================================================*
  17  *                              do_get                                       *
  18  *===========================================================================*/
  19 PUBLIC int do_get()
  20 {
  21 /* Handle GETUID, GETGID, GETPID, GETPGRP.
  22  */
  23
  24   register struct mproc *rmp = mp;
  25   int r, proc;
  26   int ngroups;
  27
  28   switch(call_nr) {
  29         case GETGROUPS:
  30                 ngroups = m_in.grp_no;
  31                 if (ngroups > NGROUPS_MAX || ngroups < 0)
  32                         return(EINVAL);
  33
  34                 if (ngroups == 0) {
  35                         r = rmp->mp_ngroups;
  36                         break;
  37                 }
  38
  39                 if (ngroups < rmp->mp_ngroups)
  40                         /* Asking for less groups than available */
  41                         return(EINVAL);
  42
  43
  44                 r = sys_datacopy(SELF, (vir_bytes) rmp->mp_sgroups, who_e,
  45                         (vir_bytes) m_in.groupsp, ngroups * sizeof(gid_t));
  46
  47                 if (r != OK)
  48                         return(r);
  49
  50                 r = rmp->mp_ngroups;
  51                 break;
  52         case GETUID:
  53                 r = rmp->mp_realuid;
  54                 rmp->mp_reply.reply_res2 = rmp->mp_effuid;
  55                 break;
  56
  57         case GETGID:
  58                 r = rmp->mp_realgid;
  59                 rmp->mp_reply.reply_res2 = rmp->mp_effgid;
  60                 break;
  61
  62         case MINIX_GETPID:
  63                 r = mproc[who_p].mp_pid;
  64                 rmp->mp_reply.reply_res2 = mproc[rmp->mp_parent].mp_pid;
  65                 break;
  66
  67         case GETPGRP:
  68                 r = rmp->mp_procgrp;
  69                 break;
  70
  71         default:
  72                 r = EINVAL;
  73                 break;
  74   }
  75   return(r);
  76 }
  77
  78 /*===========================================================================*
  79  *                              do_set                                       *
  80  *===========================================================================*/
  81 PUBLIC int do_set()
  82 {
  83 /* Handle SETUID, SETEUID, SETGID, SETEGID, SETSID. These calls have in common
  84  * that, if successful, they will be forwarded to VFS as well.
  85  */
  86   register struct mproc *rmp = mp;
  87   message m;
  88   int r, i;
  89   int ngroups;
  90
  91   switch(call_nr) {
  92         case SETUID:
  93         case SETEUID:
  94                 if (rmp->mp_realuid != (uid_t) m_in.usr_id &&
  95                                 rmp->mp_effuid != SUPER_USER)
  96                         return(EPERM);
  97                 if(call_nr == SETUID) rmp->mp_realuid = (uid_t) m_in.usr_id;
  98                 rmp->mp_effuid = (uid_t) m_in.usr_id;
  99
 100                 m.m_type = PM_SETUID;
 101                 m.PM_PROC = rmp->mp_endpoint;
 102                 m.PM_EID = rmp->mp_effuid;
 103                 m.PM_RID = rmp->mp_realuid;
 104
 105                 break;
 106
 107         case SETGID:
 108         case SETEGID:
 109                 if (rmp->mp_realgid != (gid_t) m_in.grp_id &&
 110                                 rmp->mp_effuid != SUPER_USER)
 111                         return(EPERM);
 112                 if(call_nr == SETGID) rmp->mp_realgid = (gid_t) m_in.grp_id;
 113                 rmp->mp_effgid = (gid_t) m_in.grp_id;
 114
 115                 m.m_type = PM_SETGID;
 116                 m.PM_PROC = rmp->mp_endpoint;
 117                 m.PM_EID = rmp->mp_effgid;
 118                 m.PM_RID = rmp->mp_realgid;
 119
 120                 break;
 121         case SETGROUPS:
 122                 if (rmp->mp_effuid != SUPER_USER)
 123                         return(EPERM);
 124
 125                 ngroups = m_in.grp_no;
 126
 127                 if (ngroups > NGROUPS_MAX || ngroups < 0)
 128                         return(EINVAL);
 129
 130                 if (m_in.groupsp == NULL)
 131                         return(EFAULT);
 132
 133                 r = sys_datacopy(who_e, (vir_bytes) m_in.groupsp, SELF,
 134                              (vir_bytes) rmp->mp_sgroups,
 135                              ngroups * sizeof(gid_t));
 136                 if (r != OK)
 137                         return(r);
 138
 139                 for (i = ngroups; i < NGROUPS_MAX; i++)
 140                         rmp->mp_sgroups[i] = 0;
 141                 rmp->mp_ngroups = ngroups;
 142
 143                 m.m_type = PM_SETGROUPS;
 144                 m.PM_PROC = rmp->mp_endpoint;
 145                 m.PM_GROUP_NO = rmp->mp_ngroups;
 146                 m.PM_GROUP_ADDR = rmp->mp_sgroups;
 147
 148                 break;
 149         case SETSID:
 150                 if (rmp->mp_procgrp == rmp->mp_pid) return(EPERM);
 151                 rmp->mp_procgrp = rmp->mp_pid;
 152
 153                 m.m_type = PM_SETSID;
 154                 m.PM_PROC = rmp->mp_endpoint;
 155
 156                 break;
 157
 158         default:
 159                 return(EINVAL);
 160   }
 161
 162   /* Send the request to FS */
 163   tell_fs(rmp, &m);
 164
 165   /* Do not reply until FS has processed the request */
 166   return(SUSPEND);
 167 }