fs/nfsd/auth.c

   1 /*
   2  * linux/fs/nfsd/auth.c
   3  *
   4  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   5  */
   6
   7 #include <linux/types.h>
   8 #include <linux/sched.h>
   9 #include <linux/sunrpc/svc.h>
  10 #include <linux/sunrpc/svcauth.h>
  11 #include <linux/nfsd/nfsd.h>
  12 #include <linux/nfsd/export.h>
  13 #include "auth.h"
  14
  15 int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
  16 {
  17         struct exp_flavor_info *f;
  18         struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
  19
  20         for (f = exp->ex_flavors; f < end; f++) {
  21                 if (f->pseudoflavor == rqstp->rq_flavor)
  22                         return f->flags;
  23         }
  24         return exp->ex_flags;
  25
  26 }
  27
  28 int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
  29 {
  30         struct group_info *rqgi;
  31         struct group_info *gi;
  32         struct cred *new;
  33         int i;
  34         int flags = nfsexp_flags(rqstp, exp);
  35         int ret;
  36
  37         /* discard any old override before preparing the new set */
  38         revert_creds(get_cred(current->real_cred));
  39         new = prepare_creds();
  40         if (!new)
  41                 return -ENOMEM;
  42
  43         new->fsuid = rqstp->rq_cred.cr_uid;
  44         new->fsgid = rqstp->rq_cred.cr_gid;
  45
  46         rqgi = rqstp->rq_cred.cr_group_info;
  47
  48         if (flags & NFSEXP_ALLSQUASH) {
  49                 new->fsuid = exp->ex_anon_uid;
  50                 new->fsgid = exp->ex_anon_gid;
  51                 gi = groups_alloc(0);
  52         } else if (flags & NFSEXP_ROOTSQUASH) {
  53                 if (!new->fsuid)
  54                         new->fsuid = exp->ex_anon_uid;
  55                 if (!new->fsgid)
  56                         new->fsgid = exp->ex_anon_gid;
  57
  58                 gi = groups_alloc(rqgi->ngroups);
  59                 if (!gi)
  60                         goto oom;
  61
  62                 for (i = 0; i < rqgi->ngroups; i++) {
  63                         if (!GROUP_AT(rqgi, i))
  64                                 GROUP_AT(gi, i) = exp->ex_anon_gid;
  65                         else
  66                                 GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
  67                 }
  68         } else {
  69                 gi = get_group_info(rqgi);
  70         }
  71
  72         if (new->fsuid == (uid_t) -1)
  73                 new->fsuid = exp->ex_anon_uid;
  74         if (new->fsgid == (gid_t) -1)
  75                 new->fsgid = exp->ex_anon_gid;
  76
  77         ret = set_groups(new, gi);
  78         put_group_info(gi);
  79         if (!ret)
  80                 goto error;
  81
  82         if (new->uid)
  83                 new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
  84         else
  85                 new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
  86                                                         new->cap_permitted);
  87         put_cred(override_creds(new));
  88         return 0;
  89
  90 oom:
  91         ret = -ENOMEM;
  92 error:
  93         abort_creds(new);
  94         return ret;
  95 }
  96