summaryrefslogtreecommitdiffstats
path: root/fs/nfsd/auth.c
blob: b860d3484cd75157c8a652e23047f79fb18f8ba9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
/*
 * linux/fs/nfsd/auth.c
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/export.h>
#include "auth.h"

int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
{
	struct exp_flavor_info *f;
	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;

	for (f = exp->ex_flavors; f < end; f++) {
		if (f->pseudoflavor == rqstp->rq_flavor)
			return f->flags;
	}
	return exp->ex_flags;

}

int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
{
	struct group_info *rqgi;
	struct group_info *gi;
	struct cred *new;
	int i;
	int flags = nfsexp_flags(rqstp, exp);
	int ret;

	/* discard any old override before preparing the new set */
	revert_creds(get_cred(current->real_cred));
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

	new->fsuid = rqstp->rq_cred.cr_uid;
	new->fsgid = rqstp->rq_cred.cr_gid;

	rqgi = rqstp->rq_cred.cr_group_info;

	if (flags & NFSEXP_ALLSQUASH) {
		new->fsuid = exp->ex_anon_uid;
		new->fsgid = exp->ex_anon_gid;
		gi = groups_alloc(0);
		if (!gi)
			goto oom;
	} else if (flags & NFSEXP_ROOTSQUASH) {
		if (!new->fsuid)
			new->fsuid = exp->ex_anon_uid;
		if (!new->fsgid)
			new->fsgid = exp->ex_anon_gid;

		gi = groups_alloc(rqgi->ngroups);
		if (!gi)
			goto oom;

		for (i = 0; i < rqgi->ngroups; i++) {
			if (!GROUP_AT(rqgi, i))
				GROUP_AT(gi, i) = exp->ex_anon_gid;
			else
				GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
		}
	} else {
		gi = get_group_info(rqgi);
	}

	if (new->fsuid == (uid_t) -1)
		new->fsuid = exp->ex_anon_uid;
	if (new->fsgid == (gid_t) -1)
		new->fsgid = exp->ex_anon_gid;

	ret = set_groups(new, gi);
	put_group_info(gi);
	if (ret < 0)
		goto error;

	if (new->fsuid)
		new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
	else
		new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
							new->cap_permitted);
	put_cred(override_creds(new));
	return 0;

oom:
	ret = -ENOMEM;
error:
	abort_creds(new);
	return ret;
}