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_cred.cr_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 28 validate_process_creds(); 29 30 /* discard any old override before preparing the new set */ 31 revert_creds(get_cred(current_real_cred())); 32 new = prepare_creds(); 33 if (!new) 34 return -ENOMEM; 35 36 new->fsuid = rqstp->rq_cred.cr_uid; 37 new->fsgid = rqstp->rq_cred.cr_gid; 38 39 rqgi = rqstp->rq_cred.cr_group_info; 40 41 if (flags & NFSEXP_ALLSQUASH) { 42 new->fsuid = exp->ex_anon_uid; 43 new->fsgid = exp->ex_anon_gid; 44 gi = groups_alloc(0); 45 if (!gi) 46 goto oom; 47 } else if (flags & NFSEXP_ROOTSQUASH) { 48 if (uid_eq(new->fsuid, GLOBAL_ROOT_UID)) 49 new->fsuid = exp->ex_anon_uid; 50 if (gid_eq(new->fsgid, GLOBAL_ROOT_GID)) 51 new->fsgid = exp->ex_anon_gid; 52 53 gi = groups_alloc(rqgi->ngroups); 54 if (!gi) 55 goto oom; 56 57 for (i = 0; i < rqgi->ngroups; i++) { 58 if (gid_eq(GLOBAL_ROOT_GID, GROUP_AT(rqgi, i))) 59 GROUP_AT(gi, i) = exp->ex_anon_gid; 60 else 61 GROUP_AT(gi, i) = GROUP_AT(rqgi, i); 62 } 63 } else { 64 gi = get_group_info(rqgi); 65 } 66 67 if (uid_eq(new->fsuid, INVALID_UID)) 68 new->fsuid = exp->ex_anon_uid; 69 if (gid_eq(new->fsgid, INVALID_GID)) 70 new->fsgid = exp->ex_anon_gid; 71 72 set_groups(new, gi); 73 put_group_info(gi); 74 75 if (!uid_eq(new->fsuid, GLOBAL_ROOT_UID)) 76 new->cap_effective = cap_drop_nfsd_set(new->cap_effective); 77 else 78 new->cap_effective = cap_raise_nfsd_set(new->cap_effective, 79 new->cap_permitted); 80 validate_process_creds(); 81 put_cred(override_creds(new)); 82 put_cred(new); 83 validate_process_creds(); 84 return 0; 85 86 oom: 87 abort_creds(new); 88 return -ENOMEM; 89 } 90 91