1 /* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
2
3 #include <linux/sched.h>
4 #include "nfsd.h"
5 #include "auth.h"
6
nfsexp_flags(struct svc_rqst * rqstp,struct svc_export * exp)7 int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
8 {
9 struct exp_flavor_info *f;
10 struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
11
12 for (f = exp->ex_flavors; f < end; f++) {
13 if (f->pseudoflavor == rqstp->rq_cred.cr_flavor)
14 return f->flags;
15 }
16 return exp->ex_flags;
17
18 }
19
nfsd_setuser(struct svc_rqst * rqstp,struct svc_export * exp)20 int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
21 {
22 struct group_info *rqgi;
23 struct group_info *gi;
24 struct cred *new;
25 int i;
26 int flags = nfsexp_flags(rqstp, exp);
27
28 validate_process_creds();
29
30 /* discard any old override before preparing the new set */
31 revert_creds(get_cred(current_real_cred()));
32 new = prepare_creds();
33 if (!new)
34 return -ENOMEM;
35
36 new->fsuid = rqstp->rq_cred.cr_uid;
37 new->fsgid = rqstp->rq_cred.cr_gid;
38
39 rqgi = rqstp->rq_cred.cr_group_info;
40
41 if (flags & NFSEXP_ALLSQUASH) {
42 new->fsuid = exp->ex_anon_uid;
43 new->fsgid = exp->ex_anon_gid;
44 gi = groups_alloc(0);
45 if (!gi)
46 goto oom;
47 } else if (flags & NFSEXP_ROOTSQUASH) {
48 if (uid_eq(new->fsuid, GLOBAL_ROOT_UID))
49 new->fsuid = exp->ex_anon_uid;
50 if (gid_eq(new->fsgid, GLOBAL_ROOT_GID))
51 new->fsgid = exp->ex_anon_gid;
52
53 gi = groups_alloc(rqgi->ngroups);
54 if (!gi)
55 goto oom;
56
57 for (i = 0; i < rqgi->ngroups; i++) {
58 if (gid_eq(GLOBAL_ROOT_GID, GROUP_AT(rqgi, i)))
59 GROUP_AT(gi, i) = exp->ex_anon_gid;
60 else
61 GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
62
63 }
64
65 /* Each thread allocates its own gi, no race */
66 groups_sort(gi);
67 } else {
68 gi = get_group_info(rqgi);
69 }
70
71 if (uid_eq(new->fsuid, INVALID_UID))
72 new->fsuid = exp->ex_anon_uid;
73 if (gid_eq(new->fsgid, INVALID_GID))
74 new->fsgid = exp->ex_anon_gid;
75
76 set_groups(new, gi);
77 put_group_info(gi);
78
79 if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID))
80 new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
81 else
82 new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
83 new->cap_permitted);
84 validate_process_creds();
85 put_cred(override_creds(new));
86 put_cred(new);
87 validate_process_creds();
88 return 0;
89
90 oom:
91 abort_creds(new);
92 return -ENOMEM;
93 }
94
95