lib/libminixfs/fetch_credentials.c

   1
   2 #include <minix/vfsif.h>
   3 #include <minix/type.h>
   4 #include <minix/syslib.h>
   5 #include <assert.h>
   6 #include <string.h>
   7
   8 #include "minixfs.h"
   9
  10 int fs_lookup_credentials(vfs_ucred_t *credentials,
  11         uid_t *caller_uid, gid_t *caller_gid, cp_grant_id_t grant2, size_t cred_size)
  12 {
  13   vfs_ucred_old_t old_cred;
  14   int r;
  15
  16   memset(credentials, 0, sizeof(*credentials));
  17
  18   if(cred_size == sizeof(*credentials)) {
  19            r = sys_safecopyfrom(VFS_PROC_NR, grant2, (vir_bytes) 0,
  20                                 (vir_bytes) credentials, cred_size);
  21            if (r != OK) {
  22                 printf("FS: cred copy (regular) failed.\n");
  23                 return(r);
  24            }
  25   } else if(cred_size == sizeof(old_cred)) {
  26            int g;
  27            r = sys_safecopyfrom(VFS_PROC_NR, grant2, (vir_bytes) 0,
  28                                 (vir_bytes) &old_cred, sizeof(old_cred));
  29            if (r != OK) {
  30                 printf("FS: cred copy (fallback) failed.\n");
  31                 return(r);
  32            }
  33            credentials->vu_ngroups = old_cred.vu_ngroups;
  34            credentials->vu_uid = old_cred.vu_uid;
  35            credentials->vu_gid = old_cred.vu_gid;
  36            for(g = 0; g < NGROUPS_MAX_OLD; g++) {
  37                    assert(g < NGROUPS_MAX);
  38                    credentials->vu_sgroups[g] = old_cred.vu_sgroups[g];
  39            }
  40   } else {
  41            static int w = 0;
  42            if(!w) { printf("FS: cred size incompatible with VFS.\n"); w = 1; }
  43            return(EINVAL); /* Wrong size. */
  44   }
  45
  46    assert(credentials->vu_ngroups <= NGROUPS_MAX);
  47
  48    *caller_uid = credentials->vu_uid;
  49    *caller_gid = credentials->vu_gid;
  50
  51    return OK;
  52 }
  53