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 96