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 #include <linux/nfsd/export.h> 13 #include "auth.h" 14 15 int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp) 16 { 17 struct exp_flavor_info *f; 18 struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors; 19 20 for (f = exp->ex_flavors; f < end; f++) { 21 if (f->pseudoflavor == rqstp->rq_flavor) 22 return f->flags; 23 } 24 return exp->ex_flags; 25 26 } 27 28 int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp) 29 { 30 struct group_info *rqgi; 31 struct group_info *gi; 32 struct cred *new; 33 int i; 34 int flags = nfsexp_flags(rqstp, exp); 35 int ret; 36 37 /* discard any old override before preparing the new set */ 38 revert_creds(get_cred(current->real_cred)); 39 new = prepare_creds(); 40 if (!new) 41 return -ENOMEM; 42 43 new->fsuid = rqstp->rq_cred.cr_uid; 44 new->fsgid = rqstp->rq_cred.cr_gid; 45 46 rqgi = rqstp->rq_cred.cr_group_info; 47 48 if (flags & NFSEXP_ALLSQUASH) { 49 new->fsuid = exp->ex_anon_uid; 50 new->fsgid = exp->ex_anon_gid; 51 gi = groups_alloc(0); 52 if (!gi) 53 goto oom; 54 } else if (flags & NFSEXP_ROOTSQUASH) { 55 if (!new->fsuid) 56 new->fsuid = exp->ex_anon_uid; 57 if (!new->fsgid) 58 new->fsgid = exp->ex_anon_gid; 59 60 gi = groups_alloc(rqgi->ngroups); 61 if (!gi) 62 goto oom; 63 64 for (i = 0; i < rqgi->ngroups; i++) { 65 if (!GROUP_AT(rqgi, i)) 66 GROUP_AT(gi, i) = exp->ex_anon_gid; 67 else 68 GROUP_AT(gi, i) = GROUP_AT(rqgi, i); 69 } 70 } else { 71 gi = get_group_info(rqgi); 72 } 73 74 if (new->fsuid == (uid_t) -1) 75 new->fsuid = exp->ex_anon_uid; 76 if (new->fsgid == (gid_t) -1) 77 new->fsgid = exp->ex_anon_gid; 78 79 ret = set_groups(new, gi); 80 put_group_info(gi); 81 if (ret < 0) 82 goto error; 83 84 if (new->fsuid) 85 new->cap_effective = cap_drop_nfsd_set(new->cap_effective); 86 else 87 new->cap_effective = cap_raise_nfsd_set(new->cap_effective, 88 new->cap_permitted); 89 put_cred(override_creds(new)); 90 put_cred(new); 91 return 0; 92 93 oom: 94 ret = -ENOMEM; 95 error: 96 abort_creds(new); 97 return ret; 98 } 99 100