xref: /openbmc/linux/fs/nfsd/auth.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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 
13 #define	CAP_NFSD_MASK (CAP_FS_MASK|CAP_TO_MASK(CAP_SYS_RESOURCE))
14 
15 int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
16 {
17 	struct svc_cred	*cred = &rqstp->rq_cred;
18 	int i;
19 	int ret;
20 
21 	if (exp->ex_flags & NFSEXP_ALLSQUASH) {
22 		cred->cr_uid = exp->ex_anon_uid;
23 		cred->cr_gid = exp->ex_anon_gid;
24 		put_group_info(cred->cr_group_info);
25 		cred->cr_group_info = groups_alloc(0);
26 	} else if (exp->ex_flags & NFSEXP_ROOTSQUASH) {
27 		struct group_info *gi;
28 		if (!cred->cr_uid)
29 			cred->cr_uid = exp->ex_anon_uid;
30 		if (!cred->cr_gid)
31 			cred->cr_gid = exp->ex_anon_gid;
32 		gi = groups_alloc(cred->cr_group_info->ngroups);
33 		if (gi)
34 			for (i = 0; i < cred->cr_group_info->ngroups; i++) {
35 				if (!GROUP_AT(cred->cr_group_info, i))
36 					GROUP_AT(gi, i) = exp->ex_anon_gid;
37 				else
38 					GROUP_AT(gi, i) = GROUP_AT(cred->cr_group_info, i);
39 			}
40 		put_group_info(cred->cr_group_info);
41 		cred->cr_group_info = gi;
42 	}
43 
44 	if (cred->cr_uid != (uid_t) -1)
45 		current->fsuid = cred->cr_uid;
46 	else
47 		current->fsuid = exp->ex_anon_uid;
48 	if (cred->cr_gid != (gid_t) -1)
49 		current->fsgid = cred->cr_gid;
50 	else
51 		current->fsgid = exp->ex_anon_gid;
52 
53 	if (!cred->cr_group_info)
54 		return -ENOMEM;
55 	ret = set_current_groups(cred->cr_group_info);
56 	if ((cred->cr_uid)) {
57 		cap_t(current->cap_effective) &= ~CAP_NFSD_MASK;
58 	} else {
59 		cap_t(current->cap_effective) |= (CAP_NFSD_MASK &
60 						  current->cap_permitted);
61 	}
62 	return ret;
63 }
64