bsd_acct: plain current->real_parent access is not always safe
[linux-2.6] / 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
14 int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
15 {
16         struct exp_flavor_info *f;
17         struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
18
19         for (f = exp->ex_flavors; f < end; f++) {
20                 if (f->pseudoflavor == rqstp->rq_flavor)
21                         return f->flags;
22         }
23         return exp->ex_flags;
24
25 }
26
27 int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
28 {
29         struct svc_cred cred = rqstp->rq_cred;
30         int i;
31         int flags = nfsexp_flags(rqstp, exp);
32         int ret;
33
34         if (flags & NFSEXP_ALLSQUASH) {
35                 cred.cr_uid = exp->ex_anon_uid;
36                 cred.cr_gid = exp->ex_anon_gid;
37                 cred.cr_group_info = groups_alloc(0);
38         } else if (flags & NFSEXP_ROOTSQUASH) {
39                 struct group_info *gi;
40                 if (!cred.cr_uid)
41                         cred.cr_uid = exp->ex_anon_uid;
42                 if (!cred.cr_gid)
43                         cred.cr_gid = exp->ex_anon_gid;
44                 gi = groups_alloc(cred.cr_group_info->ngroups);
45                 if (gi)
46                         for (i = 0; i < cred.cr_group_info->ngroups; i++) {
47                                 if (!GROUP_AT(cred.cr_group_info, i))
48                                         GROUP_AT(gi, i) = exp->ex_anon_gid;
49                                 else
50                                         GROUP_AT(gi, i) = GROUP_AT(cred.cr_group_info, i);
51                         }
52                 cred.cr_group_info = gi;
53         } else
54                 get_group_info(cred.cr_group_info);
55
56         if (cred.cr_uid != (uid_t) -1)
57                 current->fsuid = cred.cr_uid;
58         else
59                 current->fsuid = exp->ex_anon_uid;
60         if (cred.cr_gid != (gid_t) -1)
61                 current->fsgid = cred.cr_gid;
62         else
63                 current->fsgid = exp->ex_anon_gid;
64
65         if (!cred.cr_group_info)
66                 return -ENOMEM;
67         ret = set_current_groups(cred.cr_group_info);
68         put_group_info(cred.cr_group_info);
69         if ((cred.cr_uid)) {
70                 current->cap_effective =
71                         cap_drop_nfsd_set(current->cap_effective);
72         } else {
73                 current->cap_effective =
74                         cap_raise_nfsd_set(current->cap_effective,
75                                            current->cap_permitted);
76         }
77         return ret;
78 }