/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2008-2010 Edward Tomasz Napierała * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * ACL support routines specific to NFSv4 access control lists. These are * utility routines for code common across file systems implementing NFSv4 * ACLs. */ #ifdef _KERNEL #include #if 0 __FBSDID("$FreeBSD: head/sys/kern/subr_acl_nfs4.c 341827 2018-12-11 19:32:16Z mjg $"); #endif __KERNEL_RCSID(0, "$NetBSD: subr_acl_nfs4.c,v 1.1 2020/05/16 18:31:50 christos Exp $"); #include #include #include #include #include #include #include #include #include #include #include static void acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode); #else #include #include #include #include #define KASSERT(a) assert(a) #endif /* !_KERNEL */ #if 0 static int _acl_entry_matches(struct acl_entry *ae, acl_tag_t tag, acl_perm_t perm, acl_entry_type_t entry_type) { if (ae->ae_tag != tag) return (0); if (ae->ae_id != ACL_UNDEFINED_ID) return (0); if (ae->ae_perm != perm) return (0); if (ae->ae_entry_type != entry_type) return (0); if (ae->ae_flags != 0) return (0); return (1); } #endif static struct acl_entry * _acl_append(struct acl *aclp, acl_tag_t tag, acl_perm_t perm, acl_entry_type_t entry_type) { struct acl_entry *ae; KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES); ae = &(aclp->acl_entry[aclp->acl_cnt]); aclp->acl_cnt++; ae->ae_tag = tag; ae->ae_id = ACL_UNDEFINED_ID; ae->ae_perm = perm; ae->ae_entry_type = entry_type; ae->ae_flags = 0; return (ae); } #if 0 static struct acl_entry * _acl_duplicate_entry(struct acl *aclp, unsigned int entry_index) { size_t i; KASSERT(aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES); for (i = aclp->acl_cnt; i > entry_index; i--) aclp->acl_entry[i] = aclp->acl_entry[i - 1]; aclp->acl_cnt++; return (&(aclp->acl_entry[entry_index + 1])); } #endif #ifdef _KERNEL void acl_nfs4_sync_acl_from_mode(struct acl *aclp, mode_t mode, int file_owner_id) { acl_nfs4_trivial_from_mode(aclp, mode); } #endif /* _KERNEL */ void __acl_nfs4_sync_mode_from_acl(mode_t *_mode, const struct acl *aclp) { size_t i; mode_t old_mode = *_mode, mode = 0, seen = 0; const struct acl_entry *ae; KASSERT(aclp->acl_cnt <= ACL_MAX_ENTRIES); /* * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt * * 3.16.6.1. Recomputing mode upon SETATTR of ACL */ for (i = 0; i < aclp->acl_cnt; i++) { ae = &(aclp->acl_entry[i]); if (ae->ae_entry_type != ACL_ENTRY_TYPE_ALLOW && ae->ae_entry_type != ACL_ENTRY_TYPE_DENY) continue; if (ae->ae_flags & ACL_ENTRY_INHERIT_ONLY) continue; if (ae->ae_tag == ACL_USER_OBJ) { if ((ae->ae_perm & ACL_READ_DATA) && ((seen & S_IRUSR) == 0)) { seen |= S_IRUSR; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IRUSR; } if ((ae->ae_perm & ACL_WRITE_DATA) && ((seen & S_IWUSR) == 0)) { seen |= S_IWUSR; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IWUSR; } if ((ae->ae_perm & ACL_EXECUTE) && ((seen & S_IXUSR) == 0)) { seen |= S_IXUSR; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IXUSR; } } else if (ae->ae_tag == ACL_GROUP_OBJ) { if ((ae->ae_perm & ACL_READ_DATA) && ((seen & S_IRGRP) == 0)) { seen |= S_IRGRP; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IRGRP; } if ((ae->ae_perm & ACL_WRITE_DATA) && ((seen & S_IWGRP) == 0)) { seen |= S_IWGRP; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IWGRP; } if ((ae->ae_perm & ACL_EXECUTE) && ((seen & S_IXGRP) == 0)) { seen |= S_IXGRP; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IXGRP; } } else if (ae->ae_tag == ACL_EVERYONE) { if (ae->ae_perm & ACL_READ_DATA) { if ((seen & S_IRUSR) == 0) { seen |= S_IRUSR; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IRUSR; } if ((seen & S_IRGRP) == 0) { seen |= S_IRGRP; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IRGRP; } if ((seen & S_IROTH) == 0) { seen |= S_IROTH; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IROTH; } } if (ae->ae_perm & ACL_WRITE_DATA) { if ((seen & S_IWUSR) == 0) { seen |= S_IWUSR; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IWUSR; } if ((seen & S_IWGRP) == 0) { seen |= S_IWGRP; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IWGRP; } if ((seen & S_IWOTH) == 0) { seen |= S_IWOTH; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IWOTH; } } if (ae->ae_perm & ACL_EXECUTE) { if ((seen & S_IXUSR) == 0) { seen |= S_IXUSR; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IXUSR; } if ((seen & S_IXGRP) == 0) { seen |= S_IXGRP; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IXGRP; } if ((seen & S_IXOTH) == 0) { seen |= S_IXOTH; if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW) mode |= S_IXOTH; } } } } *_mode = mode | (old_mode & ACL_PRESERVE_MASK); } /* * Populate the ACL with entries inherited from parent_aclp. */ static void acl_nfs4_inherit_entries(const struct acl *parent_aclp, struct acl *child_aclp, mode_t mode, int file_owner_id, int is_directory) { int flags, tag; size_t i; const struct acl_entry *parent_entry; struct acl_entry *ae; KASSERT(parent_aclp->acl_cnt <= ACL_MAX_ENTRIES); for (i = 0; i < parent_aclp->acl_cnt; i++) { parent_entry = &(parent_aclp->acl_entry[i]); flags = parent_entry->ae_flags; tag = parent_entry->ae_tag; /* * Don't inherit owner@, group@, or everyone@ entries. */ if (tag == ACL_USER_OBJ || tag == ACL_GROUP_OBJ || tag == ACL_EVERYONE) continue; /* * Entry is not inheritable at all. */ if ((flags & (ACL_ENTRY_DIRECTORY_INHERIT | ACL_ENTRY_FILE_INHERIT)) == 0) continue; /* * We're creating a file, but ae is not inheritable * by files. */ if (!is_directory && (flags & ACL_ENTRY_FILE_INHERIT) == 0) continue; /* * Entry is inheritable only by files, but has NO_PROPAGATE * flag set, and we're creating a directory, so it wouldn't * propagate to any file in that directory anyway. */ if (is_directory && (flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0 && (flags & ACL_ENTRY_NO_PROPAGATE_INHERIT)) continue; /* * Entry qualifies for being inherited. */ KASSERT(child_aclp->acl_cnt + 1 <= ACL_MAX_ENTRIES); ae = &(child_aclp->acl_entry[child_aclp->acl_cnt]); *ae = *parent_entry; child_aclp->acl_cnt++; ae->ae_flags &= ~ACL_ENTRY_INHERIT_ONLY; ae->ae_flags |= ACL_ENTRY_INHERITED; /* * If the type of the ACE is neither ALLOW nor DENY, * then leave it as it is and proceed to the next one. */ if (ae->ae_entry_type != ACL_ENTRY_TYPE_ALLOW && ae->ae_entry_type != ACL_ENTRY_TYPE_DENY) continue; /* * If the ACL_ENTRY_NO_PROPAGATE_INHERIT is set, or if * the object being created is not a directory, then clear * the following flags: ACL_ENTRY_NO_PROPAGATE_INHERIT, * ACL_ENTRY_FILE_INHERIT, ACL_ENTRY_DIRECTORY_INHERIT, * ACL_ENTRY_INHERIT_ONLY. */ if (ae->ae_flags & ACL_ENTRY_NO_PROPAGATE_INHERIT || !is_directory) { ae->ae_flags &= ~(ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT | ACL_ENTRY_INHERIT_ONLY); } /* * If the object is a directory and ACL_ENTRY_FILE_INHERIT * is set, but ACL_ENTRY_DIRECTORY_INHERIT is not set, ensure * that ACL_ENTRY_INHERIT_ONLY is set. */ if (is_directory && (ae->ae_flags & ACL_ENTRY_FILE_INHERIT) && ((ae->ae_flags & ACL_ENTRY_DIRECTORY_INHERIT) == 0)) { ae->ae_flags |= ACL_ENTRY_INHERIT_ONLY; } if (ae->ae_entry_type == ACL_ENTRY_TYPE_ALLOW && (ae->ae_flags & ACL_ENTRY_INHERIT_ONLY) == 0) { /* * Some permissions must never be inherited. */ ae->ae_perm &= ~(ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_NAMED_ATTRS | ACL_WRITE_ATTRIBUTES); /* * Others must be masked according to the file mode. */ if ((mode & S_IRGRP) == 0) ae->ae_perm &= ~ACL_READ_DATA; if ((mode & S_IWGRP) == 0) ae->ae_perm &= ~(ACL_WRITE_DATA | ACL_APPEND_DATA); if ((mode & S_IXGRP) == 0) ae->ae_perm &= ~ACL_EXECUTE; } } } /* * Calculate inherited ACL in a manner compatible with PSARC/2010/029. * It's also being used to calculate a trivial ACL, by inheriting from * a NULL ACL. */ static void acl_nfs4_compute_inherited_acl_psarc(const struct acl *parent_aclp, struct acl *aclp, mode_t mode, int file_owner_id, int is_directory) { acl_perm_t user_allow_first = 0, user_deny = 0, group_deny = 0; acl_perm_t user_allow, group_allow, everyone_allow; KASSERT(aclp->acl_cnt == 0); user_allow = group_allow = everyone_allow = ACL_READ_ACL | ACL_READ_ATTRIBUTES | ACL_READ_NAMED_ATTRS | ACL_SYNCHRONIZE; user_allow |= ACL_WRITE_ACL | ACL_WRITE_OWNER | ACL_WRITE_ATTRIBUTES | ACL_WRITE_NAMED_ATTRS; if (mode & S_IRUSR) user_allow |= ACL_READ_DATA; if (mode & S_IWUSR) user_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA); if (mode & S_IXUSR) user_allow |= ACL_EXECUTE; if (mode & S_IRGRP) group_allow |= ACL_READ_DATA; if (mode & S_IWGRP) group_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA); if (mode & S_IXGRP) group_allow |= ACL_EXECUTE; if (mode & S_IROTH) everyone_allow |= ACL_READ_DATA; if (mode & S_IWOTH) everyone_allow |= (ACL_WRITE_DATA | ACL_APPEND_DATA); if (mode & S_IXOTH) everyone_allow |= ACL_EXECUTE; user_deny = ((group_allow | everyone_allow) & ~user_allow); group_deny = everyone_allow & ~group_allow; user_allow_first = group_deny & ~user_deny; if (user_allow_first != 0) _acl_append(aclp, ACL_USER_OBJ, user_allow_first, ACL_ENTRY_TYPE_ALLOW); if (user_deny != 0) _acl_append(aclp, ACL_USER_OBJ, user_deny, ACL_ENTRY_TYPE_DENY); if (group_deny != 0) _acl_append(aclp, ACL_GROUP_OBJ, group_deny, ACL_ENTRY_TYPE_DENY); if (parent_aclp != NULL) acl_nfs4_inherit_entries(parent_aclp, aclp, mode, file_owner_id, is_directory); _acl_append(aclp, ACL_USER_OBJ, user_allow, ACL_ENTRY_TYPE_ALLOW); _acl_append(aclp, ACL_GROUP_OBJ, group_allow, ACL_ENTRY_TYPE_ALLOW); _acl_append(aclp, ACL_EVERYONE, everyone_allow, ACL_ENTRY_TYPE_ALLOW); } #ifdef _KERNEL void acl_nfs4_compute_inherited_acl(const struct acl *parent_aclp, struct acl *child_aclp, mode_t mode, int file_owner_id, int is_directory) { acl_nfs4_compute_inherited_acl_psarc(parent_aclp, child_aclp, mode, file_owner_id, is_directory); } #endif /* _KERNEL */ /* * Calculate trivial ACL in a manner compatible with PSARC/2010/029. * Note that this results in an ACL different from (but semantically * equal to) the "canonical six" trivial ACL computed using algorithm * described in draft-ietf-nfsv4-minorversion1-03.txt, 3.16.6.2. */ static void acl_nfs4_trivial_from_mode(struct acl *aclp, mode_t mode) { aclp->acl_cnt = 0; acl_nfs4_compute_inherited_acl_psarc(NULL, aclp, mode, -1, -1); } #ifndef _KERNEL /* * This routine is used by libc to implement acl_strip_np(3) * and acl_is_trivial_np(3). */ void __acl_nfs4_trivial_from_mode_libc(struct acl *aclp, int mode, int canonical_six) { aclp->acl_cnt = 0; acl_nfs4_trivial_from_mode(aclp, mode); } #endif /* !_KERNEL */ #ifdef _KERNEL static int _acls_are_equal(const struct acl *a, const struct acl *b) { int i; const struct acl_entry *entrya, *entryb; if (a->acl_cnt != b->acl_cnt) return (0); for (i = 0; i < b->acl_cnt; i++) { entrya = &(a->acl_entry[i]); entryb = &(b->acl_entry[i]); if (entrya->ae_tag != entryb->ae_tag || entrya->ae_id != entryb->ae_id || entrya->ae_perm != entryb->ae_perm || entrya->ae_entry_type != entryb->ae_entry_type || entrya->ae_flags != entryb->ae_flags) return (0); } return (1); } /* * This routine is used to determine whether to remove extended attribute * that stores ACL contents. */ int acl_nfs4_is_trivial(const struct acl *aclp, int file_owner_id) { int trivial; mode_t tmpmode = 0; struct acl *tmpaclp; if (aclp->acl_cnt > 6) return (0); /* * Compute the mode from the ACL, then compute new ACL from that mode. * If the ACLs are identical, then the ACL is trivial. * * XXX: I guess there is a faster way to do this. However, even * this slow implementation significantly speeds things up * for files that don't have non-trivial ACLs - it's critical * for performance to not use EA when they are not needed. * * First try the PSARC/2010/029 semantics. */ tmpaclp = acl_alloc(KM_SLEEP); __acl_nfs4_sync_mode_from_acl(&tmpmode, aclp); acl_nfs4_trivial_from_mode(tmpaclp, tmpmode); trivial = _acls_are_equal(aclp, tmpaclp); if (trivial) { acl_free(tmpaclp); return (trivial); } /* * Check if it's a draft-ietf-nfsv4-minorversion1-03.txt trivial ACL. */ acl_free(tmpaclp); return (trivial); } int acl_nfs4_check(const struct acl *aclp, int is_directory) { size_t i; const struct acl_entry *ae; /* * The spec doesn't seem to say anything about ACL validity. * It seems there is not much to do here. There is even no need * to count "owner@" or "everyone@" (ACL_USER_OBJ and ACL_EVERYONE) * entries, as there can be several of them and that's perfectly * valid. There can be none of them too. Really. */ if (aclp->acl_cnt > ACL_MAX_ENTRIES || aclp->acl_cnt <= 0) return (EINVAL); for (i = 0; i < aclp->acl_cnt; i++) { ae = &(aclp->acl_entry[i]); switch (ae->ae_tag) { case ACL_USER_OBJ: case ACL_GROUP_OBJ: case ACL_EVERYONE: if (ae->ae_id != ACL_UNDEFINED_ID) return (EINVAL); break; case ACL_USER: case ACL_GROUP: if (ae->ae_id == ACL_UNDEFINED_ID) return (EINVAL); break; default: return (EINVAL); } if ((ae->ae_perm | ACL_NFS4_PERM_BITS) != ACL_NFS4_PERM_BITS) return (EINVAL); /* * Disallow ACL_ENTRY_TYPE_AUDIT and ACL_ENTRY_TYPE_ALARM for now. */ if (ae->ae_entry_type != ACL_ENTRY_TYPE_ALLOW && ae->ae_entry_type != ACL_ENTRY_TYPE_DENY) return (EINVAL); if ((ae->ae_flags | ACL_FLAGS_BITS) != ACL_FLAGS_BITS) return (EINVAL); /* Disallow unimplemented flags. */ if (ae->ae_flags & (ACL_ENTRY_SUCCESSFUL_ACCESS | ACL_ENTRY_FAILED_ACCESS)) return (EINVAL); /* Disallow flags not allowed for ordinary files. */ if (!is_directory) { if (ae->ae_flags & (ACL_ENTRY_FILE_INHERIT | ACL_ENTRY_DIRECTORY_INHERIT | ACL_ENTRY_NO_PROPAGATE_INHERIT | ACL_ENTRY_INHERIT_ONLY)) return (EINVAL); } } return (0); } #endif