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, rqgi->gid[i]))
59 gi->gid[i] = exp->ex_anon_gid;
60 else
61 gi->gid[i] = rqgi->gid[i];
62 }
63
64 /* Each thread allocates its own gi, no race */
65 groups_sort(gi);
66 } else {
67 gi = get_group_info(rqgi);
68 }
69
70 if (uid_eq(new->fsuid, INVALID_UID))
71 new->fsuid = exp->ex_anon_uid;
72 if (gid_eq(new->fsgid, INVALID_GID))
73 new->fsgid = exp->ex_anon_gid;
74
75 set_groups(new, gi);
76 put_group_info(gi);
77
78 if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID))
79 new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
80 else
81 new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
82 new->cap_permitted);
83 validate_process_creds();
84 put_cred(override_creds(new));
85 put_cred(new);
86 validate_process_creds();
87 return 0;
88
89 oom:
90 abort_creds(new);
91 return -ENOMEM;
92 }
93
94