diff options
Diffstat (limited to 'source4/ntvfs/posix/pvfs_acl.c')
| -rw-r--r-- | source4/ntvfs/posix/pvfs_acl.c | 1083 |
1 files changed, 1083 insertions, 0 deletions
diff --git a/source4/ntvfs/posix/pvfs_acl.c b/source4/ntvfs/posix/pvfs_acl.c new file mode 100644 index 0000000..e643293 --- /dev/null +++ b/source4/ntvfs/posix/pvfs_acl.c @@ -0,0 +1,1083 @@ +/* + Unix SMB/CIFS implementation. + + POSIX NTVFS backend - ACL support + + Copyright (C) Andrew Tridgell 2004 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "system/passwd.h" +#include "auth/auth.h" +#include "vfs_posix.h" +#include "librpc/gen_ndr/xattr.h" +#include "libcli/security/security.h" +#include "param/param.h" +#include "../lib/util/unix_privs.h" +#include "lib/util/samba_modules.h" + +/* the list of currently registered ACL backends */ +static struct pvfs_acl_backend { + const struct pvfs_acl_ops *ops; +} *backends = NULL; +static int num_backends; + +/* + register a pvfs acl backend. + + The 'name' can be later used by other backends to find the operations + structure for this backend. +*/ +NTSTATUS pvfs_acl_register(TALLOC_CTX *ctx, const struct pvfs_acl_ops *ops) +{ + struct pvfs_acl_ops *new_ops; + + if (pvfs_acl_backend_byname(ops->name) != NULL) { + DEBUG(0,("pvfs acl backend '%s' already registered\n", ops->name)); + return NT_STATUS_OBJECT_NAME_COLLISION; + } + + backends = talloc_realloc(ctx, backends, + struct pvfs_acl_backend, num_backends+1); + NT_STATUS_HAVE_NO_MEMORY(backends); + + new_ops = (struct pvfs_acl_ops *)talloc_memdup(backends, ops, sizeof(*ops)); + new_ops->name = talloc_strdup(new_ops, ops->name); + + backends[num_backends].ops = new_ops; + + num_backends++; + + DEBUG(3,("NTVFS backend '%s' registered\n", ops->name)); + + return NT_STATUS_OK; +} + + +/* + return the operations structure for a named backend +*/ +const struct pvfs_acl_ops *pvfs_acl_backend_byname(const char *name) +{ + int i; + + for (i=0;i<num_backends;i++) { + if (strcmp(backends[i].ops->name, name) == 0) { + return backends[i].ops; + } + } + + return NULL; +} + +NTSTATUS pvfs_acl_init(void) +{ + static bool initialized = false; +#define _MODULE_PROTO(init) extern NTSTATUS init(TALLOC_CTX *); + STATIC_pvfs_acl_MODULES_PROTO; + init_module_fn static_init[] = { STATIC_pvfs_acl_MODULES }; + init_module_fn *shared_init; + + if (initialized) return NT_STATUS_OK; + initialized = true; + + shared_init = load_samba_modules(NULL, "pvfs_acl"); + + run_init_functions(NULL, static_init); + run_init_functions(NULL, shared_init); + + talloc_free(shared_init); + + return NT_STATUS_OK; +} + + +/* + map a single access_mask from generic to specific bits for files/dirs +*/ +static uint32_t pvfs_translate_mask(uint32_t access_mask) +{ + if (access_mask & SEC_MASK_GENERIC) { + if (access_mask & SEC_GENERIC_READ) access_mask |= SEC_RIGHTS_FILE_READ; + if (access_mask & SEC_GENERIC_WRITE) access_mask |= SEC_RIGHTS_FILE_WRITE; + if (access_mask & SEC_GENERIC_EXECUTE) access_mask |= SEC_RIGHTS_FILE_EXECUTE; + if (access_mask & SEC_GENERIC_ALL) access_mask |= SEC_RIGHTS_FILE_ALL; + access_mask &= ~SEC_MASK_GENERIC; + } + return access_mask; +} + + +/* + map any generic access bits in the given acl + this relies on the fact that the mappings for files and directories + are the same +*/ +static void pvfs_translate_generic_bits(struct security_acl *acl) +{ + unsigned i; + + if (!acl) return; + + for (i=0;i<acl->num_aces;i++) { + struct security_ace *ace = &acl->aces[i]; + ace->access_mask = pvfs_translate_mask(ace->access_mask); + } +} + + +/* + setup a default ACL for a file +*/ +static NTSTATUS pvfs_default_acl(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, int fd, + struct security_descriptor **psd) +{ + struct security_descriptor *sd; + NTSTATUS status; + struct security_ace ace = {}; + mode_t mode; + struct id_map *ids; + + *psd = security_descriptor_initialise(req); + if (*psd == NULL) { + return NT_STATUS_NO_MEMORY; + } + sd = *psd; + + ids = talloc_zero_array(sd, struct id_map, 2); + NT_STATUS_HAVE_NO_MEMORY(ids); + + ids[0].xid.id = name->st.st_uid; + ids[0].xid.type = ID_TYPE_UID; + ids[0].sid = NULL; + + ids[1].xid.id = name->st.st_gid; + ids[1].xid.type = ID_TYPE_GID; + ids[1].sid = NULL; + + status = wbc_xids_to_sids(ids, 2); + NT_STATUS_NOT_OK_RETURN(status); + + sd->owner_sid = talloc_steal(sd, ids[0].sid); + sd->group_sid = talloc_steal(sd, ids[1].sid); + + talloc_free(ids); + sd->type |= SEC_DESC_DACL_PRESENT; + + mode = name->st.st_mode; + + /* + we provide up to 4 ACEs + - Owner + - Group + - Everyone + - Administrator + */ + + + /* setup owner ACE */ + ace.type = SEC_ACE_TYPE_ACCESS_ALLOWED; + ace.flags = 0; + ace.trustee = *sd->owner_sid; + ace.access_mask = 0; + + if (mode & S_IRUSR) { + if (mode & S_IWUSR) { + ace.access_mask |= SEC_RIGHTS_FILE_ALL; + } else { + ace.access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; + } + } + if (mode & S_IWUSR) { + ace.access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE; + } + if (ace.access_mask) { + security_descriptor_dacl_add(sd, &ace); + } + + + /* setup group ACE */ + ace.trustee = *sd->group_sid; + ace.access_mask = 0; + if (mode & S_IRGRP) { + ace.access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; + } + if (mode & S_IWGRP) { + /* note that delete is not granted - this matches posix behaviour */ + ace.access_mask |= SEC_RIGHTS_FILE_WRITE; + } + if (ace.access_mask) { + security_descriptor_dacl_add(sd, &ace); + } + + /* setup other ACE */ + ace.trustee = global_sid_World; + ace.access_mask = 0; + if (mode & S_IROTH) { + ace.access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; + } + if (mode & S_IWOTH) { + ace.access_mask |= SEC_RIGHTS_FILE_WRITE; + } + if (ace.access_mask) { + security_descriptor_dacl_add(sd, &ace); + } + + /* setup system ACE */ + ace.trustee = global_sid_System; + ace.access_mask = SEC_RIGHTS_FILE_ALL; + security_descriptor_dacl_add(sd, &ace); + + return NT_STATUS_OK; +} + + +/* + omit any security_descriptor elements not specified in the given + secinfo flags +*/ +static void normalise_sd_flags(struct security_descriptor *sd, uint32_t secinfo_flags) +{ + if (!(secinfo_flags & SECINFO_OWNER)) { + sd->owner_sid = NULL; + } + if (!(secinfo_flags & SECINFO_GROUP)) { + sd->group_sid = NULL; + } + if (!(secinfo_flags & SECINFO_DACL)) { + sd->dacl = NULL; + } + if (!(secinfo_flags & SECINFO_SACL)) { + sd->sacl = NULL; + } +} + +static bool pvfs_privileged_access(uid_t uid) +{ + uid_t euid; + + if (uid_wrapper_enabled()) { + setenv("UID_WRAPPER_MYUID", "1", 1); + } + + euid = geteuid(); + + if (uid_wrapper_enabled()) { + unsetenv("UID_WRAPPER_MYUID"); + } + + return (uid == euid); +} + +/* + answer a setfileinfo for an ACL +*/ +NTSTATUS pvfs_acl_set(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, int fd, + uint32_t access_mask, + union smb_setfileinfo *info) +{ + uint32_t secinfo_flags = info->set_secdesc.in.secinfo_flags; + struct security_descriptor *new_sd, *sd, orig_sd; + NTSTATUS status = NT_STATUS_NOT_FOUND; + uid_t old_uid = -1; + gid_t old_gid = -1; + uid_t new_uid = -1; + gid_t new_gid = -1; + struct id_map *ids; + + if (pvfs->acl_ops != NULL) { + status = pvfs->acl_ops->acl_load(pvfs, name, fd, req, &sd); + } + if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) { + status = pvfs_default_acl(pvfs, req, name, fd, &sd); + } + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + ids = talloc(req, struct id_map); + NT_STATUS_HAVE_NO_MEMORY(ids); + ZERO_STRUCT(ids->xid); + ids->sid = NULL; + ids->status = ID_UNKNOWN; + + new_sd = info->set_secdesc.in.sd; + orig_sd = *sd; + + old_uid = name->st.st_uid; + old_gid = name->st.st_gid; + + /* only set the elements that have been specified */ + if (secinfo_flags & SECINFO_OWNER) { + if (!(access_mask & SEC_STD_WRITE_OWNER)) { + return NT_STATUS_ACCESS_DENIED; + } + if (!dom_sid_equal(sd->owner_sid, new_sd->owner_sid)) { + ids->sid = new_sd->owner_sid; + status = wbc_sids_to_xids(ids, 1); + NT_STATUS_NOT_OK_RETURN(status); + + if (ids->xid.type == ID_TYPE_BOTH || + ids->xid.type == ID_TYPE_UID) { + new_uid = ids->xid.id; + } + } + sd->owner_sid = new_sd->owner_sid; + } + + if (secinfo_flags & SECINFO_GROUP) { + if (!(access_mask & SEC_STD_WRITE_OWNER)) { + return NT_STATUS_ACCESS_DENIED; + } + if (!dom_sid_equal(sd->group_sid, new_sd->group_sid)) { + ids->sid = new_sd->group_sid; + status = wbc_sids_to_xids(ids, 1); + NT_STATUS_NOT_OK_RETURN(status); + + if (ids->xid.type == ID_TYPE_BOTH || + ids->xid.type == ID_TYPE_GID) { + new_gid = ids->xid.id; + } + + } + sd->group_sid = new_sd->group_sid; + } + + if (secinfo_flags & SECINFO_DACL) { + if (!(access_mask & SEC_STD_WRITE_DAC)) { + return NT_STATUS_ACCESS_DENIED; + } + sd->dacl = new_sd->dacl; + pvfs_translate_generic_bits(sd->dacl); + sd->type |= SEC_DESC_DACL_PRESENT; + } + + if (secinfo_flags & SECINFO_SACL) { + if (!(access_mask & SEC_FLAG_SYSTEM_SECURITY)) { + return NT_STATUS_ACCESS_DENIED; + } + sd->sacl = new_sd->sacl; + pvfs_translate_generic_bits(sd->sacl); + sd->type |= SEC_DESC_SACL_PRESENT; + } + + if (secinfo_flags & SECINFO_PROTECTED_DACL) { + if (new_sd->type & SEC_DESC_DACL_PROTECTED) { + sd->type |= SEC_DESC_DACL_PROTECTED; + } else { + sd->type &= ~SEC_DESC_DACL_PROTECTED; + } + } + + if (secinfo_flags & SECINFO_PROTECTED_SACL) { + if (new_sd->type & SEC_DESC_SACL_PROTECTED) { + sd->type |= SEC_DESC_SACL_PROTECTED; + } else { + sd->type &= ~SEC_DESC_SACL_PROTECTED; + } + } + + if (new_uid == old_uid) { + new_uid = -1; + } + + if (new_gid == old_gid) { + new_gid = -1; + } + + /* if there's something to change try it */ + if (new_uid != -1 || new_gid != -1) { + int ret; + if (fd == -1) { + ret = chown(name->full_name, new_uid, new_gid); + } else { + ret = fchown(fd, new_uid, new_gid); + } + if (errno == EPERM) { + if (pvfs_privileged_access(name->st.st_uid)) { + ret = 0; + } else { + /* try again as root if we have SEC_PRIV_RESTORE or + SEC_PRIV_TAKE_OWNERSHIP */ + if (security_token_has_privilege(req->session_info->security_token, + SEC_PRIV_RESTORE) || + security_token_has_privilege(req->session_info->security_token, + SEC_PRIV_TAKE_OWNERSHIP)) { + void *privs; + privs = root_privileges(); + if (fd == -1) { + ret = chown(name->full_name, new_uid, new_gid); + } else { + ret = fchown(fd, new_uid, new_gid); + } + talloc_free(privs); + } + } + } + if (ret == -1) { + return pvfs_map_errno(pvfs, errno); + } + } + + /* we avoid saving if the sd is the same. This means when clients + copy files and end up copying the default sd that we don't + needlessly use xattrs */ + if (!security_descriptor_equal(sd, &orig_sd) && pvfs->acl_ops) { + status = pvfs->acl_ops->acl_save(pvfs, name, fd, sd); + } + + return status; +} + + +/* + answer a fileinfo query for the ACL +*/ +NTSTATUS pvfs_acl_query(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, int fd, + union smb_fileinfo *info) +{ + NTSTATUS status = NT_STATUS_NOT_FOUND; + struct security_descriptor *sd; + + if (pvfs->acl_ops) { + status = pvfs->acl_ops->acl_load(pvfs, name, fd, req, &sd); + } + if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) { + status = pvfs_default_acl(pvfs, req, name, fd, &sd); + } + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + normalise_sd_flags(sd, info->query_secdesc.in.secinfo_flags); + + info->query_secdesc.out.sd = sd; + + return NT_STATUS_OK; +} + + +/* + check the read only bit against any of the write access bits +*/ +static bool pvfs_read_only(struct pvfs_state *pvfs, uint32_t access_mask) +{ + if ((pvfs->flags & PVFS_FLAG_READONLY) && + (access_mask & (SEC_FILE_WRITE_DATA | + SEC_FILE_APPEND_DATA | + SEC_FILE_WRITE_EA | + SEC_FILE_WRITE_ATTRIBUTE | + SEC_STD_DELETE | + SEC_STD_WRITE_DAC | + SEC_STD_WRITE_OWNER | + SEC_DIR_DELETE_CHILD))) { + return true; + } + return false; +} + +/* + see if we are a member of the appropriate unix group + */ +static bool pvfs_group_member(struct pvfs_state *pvfs, gid_t gid) +{ + int i, ngroups; + gid_t *groups; + if (getegid() == gid) { + return true; + } + ngroups = getgroups(0, NULL); + if (ngroups <= 0) { + return false; + } + groups = talloc_array(pvfs, gid_t, ngroups); + if (groups == NULL) { + return false; + } + if (getgroups(ngroups, groups) != ngroups) { + talloc_free(groups); + return false; + } + for (i=0; i<ngroups; i++) { + if (groups[i] == gid) break; + } + talloc_free(groups); + return i < ngroups; +} + +/* + default access check function based on unix permissions + doing this saves on building a full security descriptor + for the common case of access check on files with no + specific NT ACL + + If name is NULL then treat as a new file creation +*/ +static NTSTATUS pvfs_access_check_unix(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + uint32_t *access_mask) +{ + uint32_t max_bits = 0; + struct security_token *token = req->session_info->security_token; + + if (pvfs_read_only(pvfs, *access_mask)) { + return NT_STATUS_ACCESS_DENIED; + } + + if (name == NULL) { + max_bits |= SEC_RIGHTS_FILE_ALL | SEC_STD_ALL; + } else if (pvfs_privileged_access(name->st.st_uid)) { + /* use the IxUSR bits */ + if ((name->st.st_mode & S_IWUSR)) { + max_bits |= SEC_RIGHTS_FILE_ALL | SEC_STD_ALL; + } else if ((name->st.st_mode & (S_IRUSR | S_IXUSR))) { + max_bits |= SEC_RIGHTS_FILE_READ | SEC_RIGHTS_FILE_EXECUTE | SEC_STD_ALL; + } + } else if (pvfs_group_member(pvfs, name->st.st_gid)) { + /* use the IxGRP bits */ + if ((name->st.st_mode & S_IWGRP)) { + max_bits |= SEC_RIGHTS_FILE_ALL | SEC_STD_ALL; + } else if ((name->st.st_mode & (S_IRGRP | S_IXGRP))) { + max_bits |= SEC_RIGHTS_FILE_READ | SEC_RIGHTS_FILE_EXECUTE | SEC_STD_ALL; + } + } else { + /* use the IxOTH bits */ + if ((name->st.st_mode & S_IWOTH)) { + max_bits |= SEC_RIGHTS_FILE_ALL | SEC_STD_ALL; + } else if ((name->st.st_mode & (S_IROTH | S_IXOTH))) { + max_bits |= SEC_RIGHTS_FILE_READ | SEC_RIGHTS_FILE_EXECUTE | SEC_STD_ALL; + } + } + + if (*access_mask & SEC_FLAG_MAXIMUM_ALLOWED) { + *access_mask |= max_bits; + *access_mask &= ~SEC_FLAG_MAXIMUM_ALLOWED; + } + + if ((*access_mask & SEC_FLAG_SYSTEM_SECURITY) && + security_token_has_privilege(token, SEC_PRIV_SECURITY)) { + max_bits |= SEC_FLAG_SYSTEM_SECURITY; + } + + if (((*access_mask & ~max_bits) & SEC_RIGHTS_PRIV_RESTORE) && + security_token_has_privilege(token, SEC_PRIV_RESTORE)) { + max_bits |= ~(SEC_RIGHTS_PRIV_RESTORE); + } + if (((*access_mask & ~max_bits) & SEC_RIGHTS_PRIV_BACKUP) && + security_token_has_privilege(token, SEC_PRIV_BACKUP)) { + max_bits |= ~(SEC_RIGHTS_PRIV_BACKUP); + } + + if (*access_mask & ~max_bits) { + DEBUG(5,(__location__ " denied access to '%s' - wanted 0x%08x but got 0x%08x (missing 0x%08x)\n", + name?name->full_name:"(new file)", *access_mask, max_bits, *access_mask & ~max_bits)); + return NT_STATUS_ACCESS_DENIED; + } + + if (pvfs->ntvfs->ctx->protocol < PROTOCOL_SMB2_02) { + /* on SMB, this bit is always granted, even if not + asked for */ + *access_mask |= SEC_FILE_READ_ATTRIBUTE; + } + + return NT_STATUS_OK; +} + + +/* + check the security descriptor on a file, if any + + *access_mask is modified with the access actually granted +*/ +NTSTATUS pvfs_access_check(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + uint32_t *access_mask) +{ + struct security_token *token = req->session_info->security_token; + struct xattr_NTACL *acl; + NTSTATUS status; + struct security_descriptor *sd; + bool allow_delete = false; + + /* on SMB2 a blank access mask is always denied */ + if (pvfs->ntvfs->ctx->protocol >= PROTOCOL_SMB2_02 && + *access_mask == 0) { + return NT_STATUS_ACCESS_DENIED; + } + + if (pvfs_read_only(pvfs, *access_mask)) { + return NT_STATUS_ACCESS_DENIED; + } + + if (*access_mask & SEC_FLAG_MAXIMUM_ALLOWED || + *access_mask & SEC_STD_DELETE) { + status = pvfs_access_check_parent(pvfs, req, + name, SEC_DIR_DELETE_CHILD); + if (NT_STATUS_IS_OK(status)) { + allow_delete = true; + *access_mask &= ~SEC_STD_DELETE; + } + } + + acl = talloc(req, struct xattr_NTACL); + if (acl == NULL) { + return NT_STATUS_NO_MEMORY; + } + + /* expand the generic access bits to file specific bits */ + *access_mask = pvfs_translate_mask(*access_mask); + if (pvfs->ntvfs->ctx->protocol < PROTOCOL_SMB2_02) { + *access_mask &= ~SEC_FILE_READ_ATTRIBUTE; + } + + status = pvfs_acl_load(pvfs, name, -1, acl); + if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) { + talloc_free(acl); + status = pvfs_access_check_unix(pvfs, req, name, access_mask); + goto done; + } + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + switch (acl->version) { + case 1: + sd = acl->info.sd; + break; + default: + return NT_STATUS_INVALID_ACL; + } + + /* check the acl against the required access mask */ + status = se_file_access_check(sd, token, false, *access_mask, access_mask); + talloc_free(acl); + + /* if we used a NT acl, then allow access override if the + share allows for posix permission override + */ + if (NT_STATUS_IS_OK(status)) { + name->allow_override = (pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) != 0; + } + +done: + if (pvfs->ntvfs->ctx->protocol < PROTOCOL_SMB2_02) { + /* on SMB, this bit is always granted, even if not + asked for */ + *access_mask |= SEC_FILE_READ_ATTRIBUTE; + } + + if (allow_delete) { + *access_mask |= SEC_STD_DELETE; + } + + return status; +} + + +/* + a simplified interface to access check, designed for calls that + do not take or return an access check mask +*/ +NTSTATUS pvfs_access_check_simple(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + uint32_t access_needed) +{ + if (access_needed == 0) { + return NT_STATUS_OK; + } + return pvfs_access_check(pvfs, req, name, &access_needed); +} + +/* + access check for creating a new file/directory +*/ +NTSTATUS pvfs_access_check_create(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + uint32_t *access_mask, + bool container, + struct security_descriptor **sd) +{ + struct pvfs_filename *parent; + NTSTATUS status; + uint32_t parent_mask; + bool allow_delete = false; + + if (pvfs_read_only(pvfs, *access_mask)) { + return NT_STATUS_ACCESS_DENIED; + } + + status = pvfs_resolve_parent(pvfs, req, name, &parent); + NT_STATUS_NOT_OK_RETURN(status); + + if (container) { + parent_mask = SEC_DIR_ADD_SUBDIR; + } else { + parent_mask = SEC_DIR_ADD_FILE; + } + if (*access_mask & SEC_FLAG_MAXIMUM_ALLOWED || + *access_mask & SEC_STD_DELETE) { + parent_mask |= SEC_DIR_DELETE_CHILD; + } + + status = pvfs_access_check(pvfs, req, parent, &parent_mask); + if (NT_STATUS_IS_OK(status)) { + if (parent_mask & SEC_DIR_DELETE_CHILD) { + allow_delete = true; + } + } else if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) { + /* + * on ACCESS_DENIED we get the rejected bits + * remove the non critical SEC_DIR_DELETE_CHILD + * and check if something else was rejected. + */ + parent_mask &= ~SEC_DIR_DELETE_CHILD; + if (parent_mask != 0) { + return NT_STATUS_ACCESS_DENIED; + } + status = NT_STATUS_OK; + } else { + return status; + } + + if (*sd == NULL) { + status = pvfs_acl_inherited_sd(pvfs, req, req, parent, container, sd); + } + + talloc_free(parent); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + /* expand the generic access bits to file specific bits */ + *access_mask = pvfs_translate_mask(*access_mask); + + if (*access_mask & SEC_FLAG_MAXIMUM_ALLOWED) { + *access_mask |= SEC_RIGHTS_FILE_ALL; + *access_mask &= ~SEC_FLAG_MAXIMUM_ALLOWED; + } + + if (pvfs->ntvfs->ctx->protocol < PROTOCOL_SMB2_02) { + /* on SMB, this bit is always granted, even if not + asked for */ + *access_mask |= SEC_FILE_READ_ATTRIBUTE; + } + + if (allow_delete) { + *access_mask |= SEC_STD_DELETE; + } + + return NT_STATUS_OK; +} + +/* + access check for creating a new file/directory - no access mask supplied +*/ +NTSTATUS pvfs_access_check_parent(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + uint32_t access_mask) +{ + struct pvfs_filename *parent; + NTSTATUS status; + + status = pvfs_resolve_parent(pvfs, req, name, &parent); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + status = pvfs_access_check_simple(pvfs, req, parent, access_mask); + if (NT_STATUS_IS_OK(status) && parent->allow_override) { + name->allow_override = true; + } + return status; +} + + +/* + determine if an ACE is inheritable +*/ +static bool pvfs_inheritable_ace(struct pvfs_state *pvfs, + const struct security_ace *ace, + bool container) +{ + if (!container) { + return (ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT) != 0; + } + + if (ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT) { + return true; + } + + if ((ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT) && + !(ace->flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT)) { + return true; + } + + return false; +} + +/* + this is the core of ACL inheritance. It copies any inheritable + aces from the parent SD to the child SD. Note that the algorithm + depends on whether the child is a container or not +*/ +static NTSTATUS pvfs_acl_inherit_aces(struct pvfs_state *pvfs, + struct security_descriptor *parent_sd, + struct security_descriptor *sd, + bool container) +{ + int i; + + for (i=0;i<parent_sd->dacl->num_aces;i++) { + struct security_ace ace = parent_sd->dacl->aces[i]; + NTSTATUS status; + const struct dom_sid *creator = NULL, *new_id = NULL; + uint32_t orig_flags; + + if (!pvfs_inheritable_ace(pvfs, &ace, container)) { + continue; + } + + orig_flags = ace.flags; + + /* see the RAW-ACLS inheritance test for details on these rules */ + if (!container) { + ace.flags = 0; + } else { + ace.flags &= ~SEC_ACE_FLAG_INHERIT_ONLY; + + if (!(ace.flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) { + ace.flags |= SEC_ACE_FLAG_INHERIT_ONLY; + } + if (ace.flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT) { + ace.flags = 0; + } + } + + /* the CREATOR sids are special when inherited */ + if (dom_sid_equal(&ace.trustee, pvfs->sid_cache.creator_owner)) { + creator = pvfs->sid_cache.creator_owner; + new_id = sd->owner_sid; + } else if (dom_sid_equal(&ace.trustee, pvfs->sid_cache.creator_group)) { + creator = pvfs->sid_cache.creator_group; + new_id = sd->group_sid; + } else { + new_id = &ace.trustee; + } + + if (creator && container && + (ace.flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) { + uint32_t flags = ace.flags; + + ace.trustee = *new_id; + ace.flags = 0; + status = security_descriptor_dacl_add(sd, &ace); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + ace.trustee = *creator; + ace.flags = flags | SEC_ACE_FLAG_INHERIT_ONLY; + status = security_descriptor_dacl_add(sd, &ace); + } else if (container && + !(orig_flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT)) { + status = security_descriptor_dacl_add(sd, &ace); + } else { + ace.trustee = *new_id; + status = security_descriptor_dacl_add(sd, &ace); + } + + if (!NT_STATUS_IS_OK(status)) { + return status; + } + } + + return NT_STATUS_OK; +} + + + +/* + calculate the ACL on a new file/directory based on the inherited ACL + from the parent. If there is no inherited ACL then return a NULL + ACL, which means the default ACL should be used +*/ +NTSTATUS pvfs_acl_inherited_sd(struct pvfs_state *pvfs, + TALLOC_CTX *mem_ctx, + struct ntvfs_request *req, + struct pvfs_filename *parent, + bool container, + struct security_descriptor **ret_sd) +{ + struct xattr_NTACL *acl; + NTSTATUS status; + struct security_descriptor *parent_sd, *sd; + struct id_map *ids; + TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx); + + *ret_sd = NULL; + + acl = talloc(req, struct xattr_NTACL); + if (acl == NULL) { + TALLOC_FREE(tmp_ctx); + return NT_STATUS_NO_MEMORY; + } + + status = pvfs_acl_load(pvfs, parent, -1, acl); + if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) { + talloc_free(tmp_ctx); + return NT_STATUS_OK; + } + if (!NT_STATUS_IS_OK(status)) { + TALLOC_FREE(tmp_ctx); + return status; + } + + switch (acl->version) { + case 1: + parent_sd = acl->info.sd; + break; + default: + talloc_free(tmp_ctx); + return NT_STATUS_INVALID_ACL; + } + + if (parent_sd == NULL || + parent_sd->dacl == NULL || + parent_sd->dacl->num_aces == 0) { + /* go with the default ACL */ + talloc_free(tmp_ctx); + return NT_STATUS_OK; + } + + /* create the new sd */ + sd = security_descriptor_initialise(req); + if (sd == NULL) { + TALLOC_FREE(tmp_ctx); + return NT_STATUS_NO_MEMORY; + } + + ids = talloc_array(sd, struct id_map, 2); + if (ids == NULL) { + TALLOC_FREE(tmp_ctx); + return NT_STATUS_NO_MEMORY; + } + + ids[0].xid.id = geteuid(); + ids[0].xid.type = ID_TYPE_UID; + ids[0].sid = NULL; + ids[0].status = ID_UNKNOWN; + + ids[1].xid.id = getegid(); + ids[1].xid.type = ID_TYPE_GID; + ids[1].sid = NULL; + ids[1].status = ID_UNKNOWN; + + status = wbc_xids_to_sids(ids, 2); + if (!NT_STATUS_IS_OK(status)) { + TALLOC_FREE(tmp_ctx); + return status; + } + + sd->owner_sid = talloc_steal(sd, ids[0].sid); + sd->group_sid = talloc_steal(sd, ids[1].sid); + + sd->type |= SEC_DESC_DACL_PRESENT; + + /* fill in the aces from the parent */ + status = pvfs_acl_inherit_aces(pvfs, parent_sd, sd, container); + if (!NT_STATUS_IS_OK(status)) { + TALLOC_FREE(tmp_ctx); + return status; + } + + /* if there is nothing to inherit then we fallback to the + default acl */ + if (sd->dacl == NULL || sd->dacl->num_aces == 0) { + talloc_free(tmp_ctx); + return NT_STATUS_OK; + } + + *ret_sd = talloc_steal(mem_ctx, sd); + + talloc_free(tmp_ctx); + return NT_STATUS_OK; +} + + +/* + setup an ACL on a new file/directory based on the inherited ACL from + the parent. If there is no inherited ACL then we don't set anything, + as the default ACL applies anyway +*/ +NTSTATUS pvfs_acl_inherit(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + int fd) +{ + struct xattr_NTACL acl; + NTSTATUS status; + struct security_descriptor *sd; + struct pvfs_filename *parent; + bool container; + + /* form the parents path */ + status = pvfs_resolve_parent(pvfs, req, name, &parent); + NT_STATUS_NOT_OK_RETURN(status); + + container = (name->dos.attrib & FILE_ATTRIBUTE_DIRECTORY) ? true:false; + + status = pvfs_acl_inherited_sd(pvfs, req, req, parent, container, &sd); + if (!NT_STATUS_IS_OK(status)) { + talloc_free(parent); + return status; + } + + if (sd == NULL) { + return NT_STATUS_OK; + } + + acl.version = 1; + acl.info.sd = sd; + + status = pvfs_acl_save(pvfs, name, fd, &acl); + talloc_free(sd); + talloc_free(parent); + + return status; +} + +/* + return the maximum allowed access mask +*/ +NTSTATUS pvfs_access_maximal_allowed(struct pvfs_state *pvfs, + struct ntvfs_request *req, + struct pvfs_filename *name, + uint32_t *maximal_access) +{ + *maximal_access = SEC_FLAG_MAXIMUM_ALLOWED; + return pvfs_access_check(pvfs, req, name, maximal_access); +} |