| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 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 | |
| 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 | |
| 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 | |