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_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 int ret;
28
29 validate_process_creds();
30
31 /* discard any old override before preparing the new set */
32 revert_creds(get_cred(current->real_cred));
33 new = prepare_creds();
34 if (!new)
35 return -ENOMEM;
36
37 new->fsuid = rqstp->rq_cred.cr_uid;
38 new->fsgid = rqstp->rq_cred.cr_gid;
39
40 rqgi = rqstp->rq_cred.cr_group_info;
41
42 if (flags & NFSEXP_ALLSQUASH) {
43 new->fsuid = exp->ex_anon_uid;
44 new->fsgid = exp->ex_anon_gid;
45 gi = groups_alloc(0);
46 if (!gi)
47 goto oom;
48 } else if (flags & NFSEXP_ROOTSQUASH) {
49 if (!new->fsuid)
50 new->fsuid = exp->ex_anon_uid;
51 if (!new->fsgid)
52 new->fsgid = exp->ex_anon_gid;
53
54 gi = groups_alloc(rqgi->ngroups);
55 if (!gi)
56 goto oom;
57
58 for (i = 0; i < rqgi->ngroups; i++) {
59 if (!GROUP_AT(rqgi, i))
60 GROUP_AT(gi, i) = exp->ex_anon_gid;
61 else
62 GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
63 }
64 } else {
65 gi = get_group_info(rqgi);
66 }
67
68 if (new->fsuid == (uid_t) -1)
69 new->fsuid = exp->ex_anon_uid;
70 if (new->fsgid == (gid_t) -1)
71 new->fsgid = exp->ex_anon_gid;
72
73 ret = set_groups(new, gi);
74 put_group_info(gi);
75 if (ret < 0)
76 goto error;
77
78 if (new->fsuid)
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 ret = -ENOMEM;
91 error:
92 abort_creds(new);
93 return ret;
94 }
95
96