/* * Store Windows ACLs in data store - common functions. * #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c * * Copyright (C) Volker Lendecke, 2008 * Copyright (C) Jeremy Allison, 2009 * * 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 . */ #include "smbd/smbd.h" #include "system/filesys.h" #include "../libcli/security/security.h" #include "../librpc/gen_ndr/ndr_security.h" #include "../lib/util/bitmap.h" #include "passdb/lookup_sid.h" static NTSTATUS create_acl_blob(const struct security_descriptor *psd, DATA_BLOB *pblob, uint16_t hash_type, uint8_t hash[XATTR_SD_HASH_SIZE]); static NTSTATUS get_acl_blob(TALLOC_CTX *ctx, vfs_handle_struct *handle, files_struct *fsp, const char *name, DATA_BLOB *pblob); static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle, files_struct *fsp, DATA_BLOB *pblob); #define HASH_SECURITY_INFO (SECINFO_OWNER | \ SECINFO_GROUP | \ SECINFO_DACL | \ SECINFO_SACL) enum default_acl_style {DEFAULT_ACL_POSIX, DEFAULT_ACL_WINDOWS}; static const struct enum_list default_acl_style[] = { {DEFAULT_ACL_POSIX, "posix"}, {DEFAULT_ACL_WINDOWS, "windows"} }; struct acl_common_config { bool ignore_system_acls; enum default_acl_style default_acl_style; }; static bool init_acl_common_config(vfs_handle_struct *handle) { struct acl_common_config *config = NULL; config = talloc_zero(handle->conn, struct acl_common_config); if (config == NULL) { DBG_ERR("talloc_zero() failed\n"); errno = ENOMEM; return false; } config->ignore_system_acls = lp_parm_bool(SNUM(handle->conn), ACL_MODULE_NAME, "ignore system acls", false); config->default_acl_style = lp_parm_enum(SNUM(handle->conn), ACL_MODULE_NAME, "default acl style", default_acl_style, DEFAULT_ACL_POSIX); SMB_VFS_HANDLE_SET_DATA(handle, config, NULL, struct acl_common_config, return false); return true; } /******************************************************************* Hash a security descriptor. *******************************************************************/ static NTSTATUS hash_blob_sha256(DATA_BLOB blob, uint8_t *hash) { SHA256_CTX tctx; memset(hash, '\0', XATTR_SD_HASH_SIZE); samba_SHA256_Init(&tctx); samba_SHA256_Update(&tctx, blob.data, blob.length); samba_SHA256_Final(hash, &tctx); return NT_STATUS_OK; } /******************************************************************* Hash a security descriptor. *******************************************************************/ static NTSTATUS hash_sd_sha256(struct security_descriptor *psd, uint8_t *hash) { DATA_BLOB blob; NTSTATUS status; memset(hash, '\0', XATTR_SD_HASH_SIZE); status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash); if (!NT_STATUS_IS_OK(status)) { return status; } return hash_blob_sha256(blob, hash); } /******************************************************************* Parse out a struct security_descriptor from a DATA_BLOB. *******************************************************************/ static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob, TALLOC_CTX *mem_ctx, struct security_descriptor **ppdesc, uint16_t *p_hash_type, uint16_t *p_version, uint8_t hash[XATTR_SD_HASH_SIZE], uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE]) { struct xattr_NTACL xacl; enum ndr_err_code ndr_err; size_t sd_size; TALLOC_CTX *frame = talloc_stackframe(); ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl, (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_INFO("ndr_pull_xattr_NTACL failed: %s\n", ndr_errstr(ndr_err)); TALLOC_FREE(frame); return ndr_map_error2ntstatus(ndr_err); } *p_version = xacl.version; switch (xacl.version) { case 1: *ppdesc = make_sec_desc(mem_ctx, SD_REVISION, xacl.info.sd->type | SEC_DESC_SELF_RELATIVE, xacl.info.sd->owner_sid, xacl.info.sd->group_sid, xacl.info.sd->sacl, xacl.info.sd->dacl, &sd_size); /* No hash - null out. */ *p_hash_type = XATTR_SD_HASH_TYPE_NONE; memset(hash, '\0', XATTR_SD_HASH_SIZE); break; case 2: *ppdesc = make_sec_desc(mem_ctx, SD_REVISION, xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE, xacl.info.sd_hs2->sd->owner_sid, xacl.info.sd_hs2->sd->group_sid, xacl.info.sd_hs2->sd->sacl, xacl.info.sd_hs2->sd->dacl, &sd_size); /* No hash - null out. */ *p_hash_type = XATTR_SD_HASH_TYPE_NONE; memset(hash, '\0', XATTR_SD_HASH_SIZE); break; case 3: *ppdesc = make_sec_desc(mem_ctx, SD_REVISION, xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE, xacl.info.sd_hs3->sd->owner_sid, xacl.info.sd_hs3->sd->group_sid, xacl.info.sd_hs3->sd->sacl, xacl.info.sd_hs3->sd->dacl, &sd_size); *p_hash_type = xacl.info.sd_hs3->hash_type; /* Current version 3 (if no sys acl hash available). */ memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE); break; case 4: *ppdesc = make_sec_desc(mem_ctx, SD_REVISION, xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE, xacl.info.sd_hs4->sd->owner_sid, xacl.info.sd_hs4->sd->group_sid, xacl.info.sd_hs4->sd->sacl, xacl.info.sd_hs4->sd->dacl, &sd_size); *p_hash_type = xacl.info.sd_hs4->hash_type; /* Current version 4. */ memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE); memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE); break; default: TALLOC_FREE(frame); return NT_STATUS_REVISION_MISMATCH; } TALLOC_FREE(frame); return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY; } /******************************************************************* Create a DATA_BLOB from a hash of the security descriptor storead at the system layer and the NT ACL we wish to preserve *******************************************************************/ static NTSTATUS create_acl_blob(const struct security_descriptor *psd, DATA_BLOB *pblob, uint16_t hash_type, uint8_t hash[XATTR_SD_HASH_SIZE]) { struct xattr_NTACL xacl; struct security_descriptor_hash_v3 sd_hs3; enum ndr_err_code ndr_err; TALLOC_CTX *ctx = talloc_tos(); ZERO_STRUCT(xacl); ZERO_STRUCT(sd_hs3); xacl.version = 3; xacl.info.sd_hs3 = &sd_hs3; xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd); xacl.info.sd_hs3->hash_type = hash_type; memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE); ndr_err = ndr_push_struct_blob( pblob, ctx, &xacl, (ndr_push_flags_fn_t)ndr_push_xattr_NTACL); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_INFO("ndr_push_xattr_NTACL failed: %s\n", ndr_errstr(ndr_err)); return ndr_map_error2ntstatus(ndr_err); } return NT_STATUS_OK; } /******************************************************************* Create a DATA_BLOB from a hash of the security descriptors (system and NT) stored at the system layer and the NT ACL we wish to preserve. *******************************************************************/ static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd, DATA_BLOB *pblob, uint16_t hash_type, uint8_t hash[XATTR_SD_HASH_SIZE], const char *description, uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE]) { struct xattr_NTACL xacl; struct security_descriptor_hash_v4 sd_hs4; enum ndr_err_code ndr_err; TALLOC_CTX *ctx = talloc_tos(); NTTIME nttime_now; struct timeval now = timeval_current(); nttime_now = timeval_to_nttime(&now); ZERO_STRUCT(xacl); ZERO_STRUCT(sd_hs4); xacl.version = 4; xacl.info.sd_hs4 = &sd_hs4; xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd); xacl.info.sd_hs4->hash_type = hash_type; memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE); xacl.info.sd_hs4->description = description; xacl.info.sd_hs4->time = nttime_now; memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE); ndr_err = ndr_push_struct_blob( pblob, ctx, &xacl, (ndr_push_flags_fn_t)ndr_push_xattr_NTACL); if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { DBG_INFO("ndr_push_xattr_NTACL failed: %s\n", ndr_errstr(ndr_err)); return ndr_map_error2ntstatus(ndr_err); } return NT_STATUS_OK; } /******************************************************************* Add in 3 inheritable components for a non-inheritable directory ACL. CREATOR_OWNER/CREATOR_GROUP/WORLD. *******************************************************************/ static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle, const char *name, SMB_STRUCT_STAT *psbuf, struct security_descriptor *psd) { struct connection_struct *conn = handle->conn; int num_aces = (psd->dacl ? psd->dacl->num_aces : 0); struct smb_filename smb_fname; enum security_ace_type acltype; uint32_t access_mask; mode_t dir_mode; mode_t file_mode; mode_t mode; struct security_ace *new_ace_list; if (psd->dacl) { new_ace_list = talloc_zero_array(psd->dacl, struct security_ace, num_aces + 3); } else { /* * make_sec_acl() at the bottom of this function * dupliates new_ace_list */ new_ace_list = talloc_zero_array(talloc_tos(), struct security_ace, num_aces + 3); } if (new_ace_list == NULL) { return NT_STATUS_NO_MEMORY; } /* Fake a quick smb_filename. */ ZERO_STRUCT(smb_fname); smb_fname.st = *psbuf; smb_fname.base_name = discard_const_p(char, name); dir_mode = unix_mode(conn, FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL); file_mode = unix_mode(conn, FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL); mode = dir_mode | file_mode; DBG_DEBUG("directory %s, mode = 0%o\n", name, (unsigned int)mode); if (num_aces) { memcpy(new_ace_list, psd->dacl->aces, num_aces * sizeof(struct security_ace)); } access_mask = map_canon_ace_perms(SNUM(conn), &acltype, mode & 0700, false); init_sec_ace(&new_ace_list[num_aces], &global_sid_Creator_Owner, acltype, access_mask, SEC_ACE_FLAG_CONTAINER_INHERIT| SEC_ACE_FLAG_OBJECT_INHERIT| SEC_ACE_FLAG_INHERIT_ONLY); access_mask = map_canon_ace_perms(SNUM(conn), &acltype, (mode << 3) & 0700, false); init_sec_ace(&new_ace_list[num_aces+1], &global_sid_Creator_Group, acltype, access_mask, SEC_ACE_FLAG_CONTAINER_INHERIT| SEC_ACE_FLAG_OBJECT_INHERIT| SEC_ACE_FLAG_INHERIT_ONLY); access_mask = map_canon_ace_perms(SNUM(conn), &acltype, (mode << 6) & 0700, false); init_sec_ace(&new_ace_list[num_aces+2], &global_sid_World, acltype, access_mask, SEC_ACE_FLAG_CONTAINER_INHERIT| SEC_ACE_FLAG_OBJECT_INHERIT| SEC_ACE_FLAG_INHERIT_ONLY); if (psd->dacl) { psd->dacl->aces = new_ace_list; psd->dacl->num_aces += 3; psd->dacl->size += new_ace_list[num_aces].size + new_ace_list[num_aces+1].size + new_ace_list[num_aces+2].size; } else { psd->dacl = make_sec_acl(psd, NT4_ACL_REVISION, 3, new_ace_list); if (psd->dacl == NULL) { return NT_STATUS_NO_MEMORY; } } return NT_STATUS_OK; } static NTSTATUS make_default_acl_posix(TALLOC_CTX *ctx, const char *name, SMB_STRUCT_STAT *psbuf, struct security_descriptor **ppdesc) { struct dom_sid owner_sid, group_sid; size_t size = 0; struct security_ace aces[4]; uint32_t access_mask = 0; mode_t mode = psbuf->st_ex_mode; struct security_acl *new_dacl = NULL; int idx = 0; DBG_DEBUG("file %s mode = 0%o\n",name, (int)mode); uid_to_sid(&owner_sid, psbuf->st_ex_uid); gid_to_sid(&group_sid, psbuf->st_ex_gid); /* We provide up to 4 ACEs - Owner - Group - Everyone - NT System */ if (mode & S_IRUSR) { if (mode & S_IWUSR) { access_mask |= SEC_RIGHTS_FILE_ALL; } else { access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; } } if (mode & S_IWUSR) { access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE; } init_sec_ace(&aces[idx], &owner_sid, SEC_ACE_TYPE_ACCESS_ALLOWED, access_mask, 0); idx++; access_mask = 0; if (mode & S_IRGRP) { access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; } if (mode & S_IWGRP) { /* note that delete is not granted - this matches posix behaviour */ access_mask |= SEC_RIGHTS_FILE_WRITE; } if (access_mask) { init_sec_ace(&aces[idx], &group_sid, SEC_ACE_TYPE_ACCESS_ALLOWED, access_mask, 0); idx++; } access_mask = 0; if (mode & S_IROTH) { access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; } if (mode & S_IWOTH) { access_mask |= SEC_RIGHTS_FILE_WRITE; } if (access_mask) { init_sec_ace(&aces[idx], &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, access_mask, 0); idx++; } init_sec_ace(&aces[idx], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED, SEC_RIGHTS_FILE_ALL, 0); idx++; new_dacl = make_sec_acl(ctx, NT4_ACL_REVISION, idx, aces); if (!new_dacl) { return NT_STATUS_NO_MEMORY; } *ppdesc = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1, SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT, &owner_sid, &group_sid, NULL, new_dacl, &size); if (!*ppdesc) { return NT_STATUS_NO_MEMORY; } return NT_STATUS_OK; } static NTSTATUS make_default_acl_windows(TALLOC_CTX *ctx, const char *name, SMB_STRUCT_STAT *psbuf, struct security_descriptor **ppdesc) { struct dom_sid owner_sid, group_sid; size_t size = 0; struct security_ace aces[4]; uint32_t access_mask = 0; mode_t mode = psbuf->st_ex_mode; struct security_acl *new_dacl = NULL; int idx = 0; DBG_DEBUG("file [%s] mode [0%o]\n", name, (int)mode); uid_to_sid(&owner_sid, psbuf->st_ex_uid); gid_to_sid(&group_sid, psbuf->st_ex_gid); /* * We provide 2 ACEs: * - Owner * - NT System */ if (mode & S_IRUSR) { if (mode & S_IWUSR) { access_mask |= SEC_RIGHTS_FILE_ALL; } else { access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE; } } if (mode & S_IWUSR) { access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE; } init_sec_ace(&aces[idx], &owner_sid, SEC_ACE_TYPE_ACCESS_ALLOWED, access_mask, 0); idx++; init_sec_ace(&aces[idx], &global_sid_System, SEC_ACE_TYPE_ACCESS_ALLOWED, SEC_RIGHTS_FILE_ALL, 0); idx++; new_dacl = make_sec_acl(ctx, NT4_ACL_REVISION, idx, aces); if (!new_dacl) { return NT_STATUS_NO_MEMORY; } *ppdesc = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1, SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT, &owner_sid, &group_sid, NULL, new_dacl, &size); if (!*ppdesc) { return NT_STATUS_NO_MEMORY; } return NT_STATUS_OK; } static NTSTATUS make_default_filesystem_acl(TALLOC_CTX *ctx, struct acl_common_config *config, const char *name, SMB_STRUCT_STAT *psbuf, struct security_descriptor **ppdesc) { NTSTATUS status; switch (config->default_acl_style) { case DEFAULT_ACL_POSIX: status = make_default_acl_posix(ctx, name, psbuf, ppdesc); break; case DEFAULT_ACL_WINDOWS: status = make_default_acl_windows(ctx, name, psbuf, ppdesc); break; default: DBG_ERR("unknown acl style %d", config->default_acl_style); status = NT_STATUS_INTERNAL_ERROR; break; } return status; } /** * Validate an ACL blob * * This validates an ACL blob against the underlying filesystem ACL. If this * function returns NT_STATUS_OK ppsd can be * * 1. the ACL from the blob (psd_from_fs=false), or * 2. the ACL from the fs (psd_from_fs=true), or * 3. NULL (!) * * If the return value is anything else then NT_STATUS_OK, ppsd is set to NULL * and psd_from_fs set to false. * * Returning the underlying filesystem ACL in case no. 2 is really just an * optimisation, because some validations have to fetch the filesytem ACL as * part of the validation, so we already have it available and callers might * need it as well. **/ static NTSTATUS validate_nt_acl_blob(TALLOC_CTX *mem_ctx, vfs_handle_struct *handle, files_struct *fsp, const char *name, const DATA_BLOB *blob, struct security_descriptor **ppsd, bool *psd_is_from_fs) { NTSTATUS status; uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE; uint16_t xattr_version = 0; uint8_t hash[XATTR_SD_HASH_SIZE]; uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE]; uint8_t hash_tmp[XATTR_SD_HASH_SIZE]; uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE]; struct security_descriptor *psd = NULL; struct security_descriptor *psd_blob = NULL; struct security_descriptor *psd_fs = NULL; char *sys_acl_blob_description = NULL; DATA_BLOB sys_acl_blob = { 0 }; struct acl_common_config *config = NULL; *ppsd = NULL; *psd_is_from_fs = false; SMB_VFS_HANDLE_GET_DATA(handle, config, struct acl_common_config, return NT_STATUS_UNSUCCESSFUL); status = parse_acl_blob(blob, mem_ctx, &psd_blob, &hash_type, &xattr_version, &hash[0], &sys_acl_hash[0]); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("parse_acl_blob returned %s\n", nt_errstr(status)); goto fail; } /* determine which type of xattr we got */ switch (xattr_version) { case 1: case 2: /* These xattr types are unilatteral, they do not * require confirmation of the hash. In particular, * the NTVFS file server uses version 1, but * 'samba-tool ntacl' can set these as well */ *ppsd = psd_blob; return NT_STATUS_OK; case 3: case 4: if (config->ignore_system_acls) { *ppsd = psd_blob; return NT_STATUS_OK; } break; default: DBG_DEBUG("ACL blob revision mismatch (%u) for file %s\n", (unsigned int)hash_type, name); TALLOC_FREE(psd_blob); return NT_STATUS_OK; } /* determine which type of xattr we got */ if (hash_type != XATTR_SD_HASH_TYPE_SHA256) { DBG_DEBUG("ACL blob hash type (%u) unexpected for file %s\n", (unsigned int)hash_type, name); TALLOC_FREE(psd_blob); return NT_STATUS_OK; } /* determine which type of xattr we got */ switch (xattr_version) { case 4: { int ret; if (fsp) { /* Get the full underlying sd, then hash. */ ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle, fsp, mem_ctx, &sys_acl_blob_description, &sys_acl_blob); } else { /* Get the full underlying sd, then hash. */ ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle, name, mem_ctx, &sys_acl_blob_description, &sys_acl_blob); } /* If we fail to get the ACL blob (for some reason) then this * is not fatal, we just work based on the NT ACL only */ if (ret == 0) { status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp); if (!NT_STATUS_IS_OK(status)) { goto fail; } TALLOC_FREE(sys_acl_blob_description); TALLOC_FREE(sys_acl_blob.data); if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) { /* Hash matches, return blob sd. */ DBG_DEBUG("blob hash matches for file %s\n", name); *ppsd = psd_blob; return NT_STATUS_OK; } } /* Otherwise, fall though and see if the NT ACL hash matches */ } case 3: /* Get the full underlying sd for the hash or to return as backup. */ if (fsp) { status = SMB_VFS_NEXT_FGET_NT_ACL(handle, fsp, HASH_SECURITY_INFO, mem_ctx, &psd_fs); } else { status = SMB_VFS_NEXT_GET_NT_ACL(handle, name, HASH_SECURITY_INFO, mem_ctx, &psd_fs); } if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("get_next_acl for file %s returned %s\n", name, nt_errstr(status)); goto fail; } status = hash_sd_sha256(psd_fs, hash_tmp); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(psd_blob); *ppsd = psd_fs; *psd_is_from_fs = true; return NT_STATUS_OK; } if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) { /* Hash matches, return blob sd. */ DBG_DEBUG("blob hash matches for file %s\n", name); *ppsd = psd_blob; return NT_STATUS_OK; } /* Hash doesn't match, return underlying sd. */ DBG_DEBUG("blob hash does not match for file %s - returning " "file system SD mapping.\n", name); if (DEBUGLEVEL >= 10) { DBG_DEBUG("acl for blob hash for %s is:\n", name); NDR_PRINT_DEBUG(security_descriptor, psd_fs); } TALLOC_FREE(psd_blob); *ppsd = psd_fs; *psd_is_from_fs = true; } return NT_STATUS_OK; fail: TALLOC_FREE(psd); TALLOC_FREE(psd_blob); TALLOC_FREE(psd_fs); TALLOC_FREE(sys_acl_blob_description); TALLOC_FREE(sys_acl_blob.data); return status; } static NTSTATUS stat_fsp_or_name(vfs_handle_struct *handle, files_struct *fsp, const char *name, SMB_STRUCT_STAT *sbuf, SMB_STRUCT_STAT **psbuf) { NTSTATUS status; int ret; if (fsp) { status = vfs_stat_fsp(fsp); if (!NT_STATUS_IS_OK(status)) { return status; } *psbuf = &fsp->fsp_name->st; } else { /* * https://bugzilla.samba.org/show_bug.cgi?id=11249 * * We are currently guaranteed that 'name' here is a * smb_fname->base_name, which *cannot* contain a stream name * (':'). vfs_stat_smb_fname() splits a name into a base name + * stream name, which when we get here we know we've already * done. So we have to call the stat or lstat VFS calls * directly here. Else, a base_name that contains a ':' (from a * demangled name) will get split again. * * FIXME. * This uglyness will go away once smb_fname is fully plumbed * through the VFS. */ ret = vfs_stat_smb_basename(handle->conn, name, sbuf); if (ret == -1) { return map_nt_error_from_unix(errno); } } return NT_STATUS_OK; } /******************************************************************* Pull a DATA_BLOB from an xattr given a pathname. If the hash doesn't match, or doesn't exist - return the underlying filesystem sd. *******************************************************************/ static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle, files_struct *fsp, const char *name, uint32_t security_info, TALLOC_CTX *mem_ctx, struct security_descriptor **ppdesc) { DATA_BLOB blob = data_blob_null; NTSTATUS status; struct security_descriptor *psd = NULL; bool psd_is_from_fs = false; struct acl_common_config *config = NULL; SMB_VFS_HANDLE_GET_DATA(handle, config, struct acl_common_config, return NT_STATUS_UNSUCCESSFUL); if (fsp && name == NULL) { name = fsp->fsp_name->base_name; } DBG_DEBUG("name=%s\n", name); status = get_acl_blob(mem_ctx, handle, fsp, name, &blob); if (NT_STATUS_IS_OK(status)) { status = validate_nt_acl_blob(mem_ctx, handle, fsp, name, &blob, &psd, &psd_is_from_fs); TALLOC_FREE(blob.data); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("ACL validation for [%s] failed\n", name); goto fail; } } if (psd == NULL) { /* Get the full underlying sd, as we failed to get the * blob for the hash, or the revision/hash type wasn't * known */ if (config->ignore_system_acls) { SMB_STRUCT_STAT sbuf; SMB_STRUCT_STAT *psbuf = &sbuf; status = stat_fsp_or_name(handle, fsp, name, &sbuf, &psbuf); if (!NT_STATUS_IS_OK(status)) { goto fail; } status = make_default_filesystem_acl( mem_ctx, config, name, psbuf, &psd); if (!NT_STATUS_IS_OK(status)) { goto fail; } } else { if (fsp) { status = SMB_VFS_NEXT_FGET_NT_ACL(handle, fsp, security_info, mem_ctx, &psd); } else { status = SMB_VFS_NEXT_GET_NT_ACL(handle, name, security_info, mem_ctx, &psd); } if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("get_next_acl for file %s " "returned %s\n", name, nt_errstr(status)); goto fail; } psd_is_from_fs = true; } } if (psd_is_from_fs) { SMB_STRUCT_STAT sbuf; SMB_STRUCT_STAT *psbuf = &sbuf; bool is_directory = false; /* * We're returning the underlying ACL from the * filesystem. If it's a directory, and has no * inheritable ACE entries we have to fake them. */ status = stat_fsp_or_name(handle, fsp, name, &sbuf, &psbuf); if (!NT_STATUS_IS_OK(status)) { goto fail; } is_directory = S_ISDIR(psbuf->st_ex_mode); if (is_directory && !sd_has_inheritable_components(psd, true)) { status = add_directory_inheritable_components( handle, name, psbuf, psd); if (!NT_STATUS_IS_OK(status)) { goto fail; } } /* * The underlying POSIX module always sets the * ~SEC_DESC_DACL_PROTECTED bit, as ACLs can't be inherited in * this way under POSIX. Remove it for Windows-style ACLs. */ psd->type &= ~SEC_DESC_DACL_PROTECTED; } if (!(security_info & SECINFO_OWNER)) { psd->owner_sid = NULL; } if (!(security_info & SECINFO_GROUP)) { psd->group_sid = NULL; } if (!(security_info & SECINFO_DACL)) { psd->type &= ~SEC_DESC_DACL_PRESENT; psd->dacl = NULL; } if (!(security_info & SECINFO_SACL)) { psd->type &= ~SEC_DESC_SACL_PRESENT; psd->sacl = NULL; } if (DEBUGLEVEL >= 10) { DBG_DEBUG("returning acl for %s is:\n", name); NDR_PRINT_DEBUG(security_descriptor, psd); } *ppdesc = psd; return NT_STATUS_OK; fail: TALLOC_FREE(psd); return status; } /********************************************************************* Fetch a security descriptor given an fsp. *********************************************************************/ static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp, uint32_t security_info, TALLOC_CTX *mem_ctx, struct security_descriptor **ppdesc) { return get_nt_acl_internal(handle, fsp, NULL, security_info, mem_ctx, ppdesc); } /********************************************************************* Fetch a security descriptor given a pathname. *********************************************************************/ static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle, const char *name, uint32_t security_info, TALLOC_CTX *mem_ctx, struct security_descriptor **ppdesc) { return get_nt_acl_internal(handle, NULL, name, security_info, mem_ctx, ppdesc); } /********************************************************************* Set the underlying ACL (e.g. POSIX ACLS, POSIX owner, etc) *********************************************************************/ static NTSTATUS set_underlying_acl(vfs_handle_struct *handle, files_struct *fsp, struct security_descriptor *psd, uint32_t security_info_sent, bool chown_needed) { NTSTATUS status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd); if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) { return status; } /* We got access denied here. If we're already root, or we didn't need to do a chown, or the fsp isn't open with WRITE_OWNER access, just return. */ if (get_current_uid(handle->conn) == 0 || chown_needed == false || !(fsp->access_mask & SEC_STD_WRITE_OWNER)) { return NT_STATUS_ACCESS_DENIED; } DBG_DEBUG("overriding chown on file %s for sid %s\n", fsp_str_dbg(fsp), sid_string_tos(psd->owner_sid)); /* Ok, we failed to chown and we have SEC_STD_WRITE_OWNER access - override. */ become_root(); status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd); unbecome_root(); return status; } /********************************************************************* Store a v3 security descriptor *********************************************************************/ static NTSTATUS store_v3_blob(vfs_handle_struct *handle, files_struct *fsp, struct security_descriptor *psd, struct security_descriptor *pdesc_next, uint8_t hash[XATTR_SD_HASH_SIZE]) { NTSTATUS status; DATA_BLOB blob; if (DEBUGLEVEL >= 10) { DBG_DEBUG("storing xattr sd for file %s\n", fsp_str_dbg(fsp)); NDR_PRINT_DEBUG( security_descriptor, discard_const_p(struct security_descriptor, psd)); if (pdesc_next != NULL) { DBG_DEBUG("storing xattr sd based on \n"); NDR_PRINT_DEBUG( security_descriptor, discard_const_p(struct security_descriptor, pdesc_next)); } else { DBG_DEBUG("ignoring underlying sd\n"); } } status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("create_acl_blob failed\n"); return status; } status = store_acl_blob_fsp(handle, fsp, &blob); return status; } /********************************************************************* Store a security descriptor given an fsp. *********************************************************************/ static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp, uint32_t security_info_sent, const struct security_descriptor *orig_psd) { NTSTATUS status; int ret; DATA_BLOB blob, sys_acl_blob; struct security_descriptor *pdesc_next = NULL; struct security_descriptor *psd = NULL; uint8_t hash[XATTR_SD_HASH_SIZE]; uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE]; bool chown_needed = false; char *sys_acl_description; TALLOC_CTX *frame = talloc_stackframe(); bool ignore_file_system_acl = lp_parm_bool( SNUM(handle->conn), ACL_MODULE_NAME, "ignore system acls", false); if (DEBUGLEVEL >= 10) { DBG_DEBUG("incoming sd for file %s\n", fsp_str_dbg(fsp)); NDR_PRINT_DEBUG(security_descriptor, discard_const_p(struct security_descriptor, orig_psd)); } status = get_nt_acl_internal(handle, fsp, NULL, SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL, frame, &psd); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(frame); return status; } psd->revision = orig_psd->revision; /* All our SD's are self relative. */ psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE; if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) { if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) { /* We're changing the owner. */ chown_needed = true; } psd->owner_sid = orig_psd->owner_sid; } if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) { if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) { /* We're changing the group. */ chown_needed = true; } psd->group_sid = orig_psd->group_sid; } if (security_info_sent & SECINFO_DACL) { if (security_descriptor_with_ms_nfs(orig_psd)) { /* * If the sd contains a MS NFS SID, do * nothing, it's a chmod() request from OS X * with AAPL context. */ TALLOC_FREE(frame); return NT_STATUS_OK; } psd->dacl = orig_psd->dacl; psd->type |= SEC_DESC_DACL_PRESENT; } if (security_info_sent & SECINFO_SACL) { psd->sacl = orig_psd->sacl; psd->type |= SEC_DESC_SACL_PRESENT; } if (ignore_file_system_acl) { if (chown_needed) { /* send only ownership stuff to lower layer */ security_info_sent &= (SECINFO_OWNER | SECINFO_GROUP); status = set_underlying_acl(handle, fsp, psd, security_info_sent, true); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(frame); return status; } } ZERO_ARRAY(hash); status = store_v3_blob(handle, fsp, psd, NULL, hash); TALLOC_FREE(frame); return status; } status = set_underlying_acl(handle, fsp, psd, security_info_sent, chown_needed); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(frame); return status; } /* Get the full underlying sd, then hash. */ status = SMB_VFS_NEXT_FGET_NT_ACL(handle, fsp, HASH_SECURITY_INFO, frame, &pdesc_next); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(frame); return status; } status = hash_sd_sha256(pdesc_next, hash); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(frame); return status; } /* Get the full underlying sd, then hash. */ ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle, fsp, frame, &sys_acl_description, &sys_acl_blob); /* If we fail to get the ACL blob (for some reason) then this * is not fatal, we just work based on the NT ACL only */ if (ret != 0) { status = store_v3_blob(handle, fsp, psd, pdesc_next, hash); TALLOC_FREE(frame); return status; } status = hash_blob_sha256(sys_acl_blob, sys_acl_hash); if (!NT_STATUS_IS_OK(status)) { TALLOC_FREE(frame); return status; } if (DEBUGLEVEL >= 10) { DBG_DEBUG("storing xattr sd for file %s based on system ACL\n", fsp_str_dbg(fsp)); NDR_PRINT_DEBUG(security_descriptor, discard_const_p(struct security_descriptor, psd)); DBG_DEBUG("storing hash in xattr sd based on system ACL and:\n"); NDR_PRINT_DEBUG(security_descriptor, discard_const_p(struct security_descriptor, pdesc_next)); } /* We store hashes of both the sys ACL blob and the NT * security desciptor mapped from that ACL so as to improve * our chances against some inadvertant change breaking the * hash used */ status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash, sys_acl_description, sys_acl_hash); if (!NT_STATUS_IS_OK(status)) { DBG_DEBUG("create_sys_acl_blob failed\n"); TALLOC_FREE(frame); return status; } status = store_acl_blob_fsp(handle, fsp, &blob); TALLOC_FREE(frame); return status; } static int acl_common_remove_object(vfs_handle_struct *handle, const char *path, bool is_directory) { connection_struct *conn = handle->conn; struct file_id id; files_struct *fsp = NULL; int ret = 0; char *parent_dir = NULL; const char *final_component = NULL; struct smb_filename local_fname; int saved_errno = 0; char *saved_dir = NULL; saved_dir = vfs_GetWd(talloc_tos(),conn); if (!saved_dir) { saved_errno = errno; goto out; } if (!parent_dirname(talloc_tos(), path, &parent_dir, &final_component)) { saved_errno = ENOMEM; goto out; } DBG_DEBUG("removing %s %s/%s\n", is_directory ? "directory" : "file", parent_dir, final_component); /* cd into the parent dir to pin it. */ ret = vfs_ChDir(conn, parent_dir); if (ret == -1) { saved_errno = errno; goto out; } ZERO_STRUCT(local_fname); local_fname.base_name = discard_const_p(char, final_component); /* Must use lstat here. */ ret = SMB_VFS_LSTAT(conn, &local_fname); if (ret == -1) { saved_errno = errno; goto out; } /* Ensure we have this file open with DELETE access. */ id = vfs_file_id_from_sbuf(conn, &local_fname.st); for (fsp = file_find_di_first(conn->sconn, id); fsp; fsp = file_find_di_next(fsp)) { if (fsp->access_mask & DELETE_ACCESS && fsp->delete_on_close) { /* We did open this for delete, * allow the delete as root. */ break; } } if (!fsp) { DBG_DEBUG("%s %s/%s not an open file\n", is_directory ? "directory" : "file", parent_dir, final_component); saved_errno = EACCES; goto out; } become_root(); if (is_directory) { ret = SMB_VFS_NEXT_RMDIR(handle, final_component); } else { ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname); } unbecome_root(); if (ret == -1) { saved_errno = errno; } out: TALLOC_FREE(parent_dir); if (saved_dir) { vfs_ChDir(conn, saved_dir); } if (saved_errno) { errno = saved_errno; } return ret; } static int rmdir_acl_common(struct vfs_handle_struct *handle, const char *path) { int ret; /* Try the normal rmdir first. */ ret = SMB_VFS_NEXT_RMDIR(handle, path); if (ret == 0) { return 0; } if (errno == EACCES || errno == EPERM) { /* Failed due to access denied, see if we need to root override. */ return acl_common_remove_object(handle, path, true); } DBG_DEBUG("unlink of %s failed %s\n", path, strerror(errno)); return -1; } static int unlink_acl_common(struct vfs_handle_struct *handle, const struct smb_filename *smb_fname) { int ret; /* Try the normal unlink first. */ ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname); if (ret == 0) { return 0; } if (errno == EACCES || errno == EPERM) { /* Failed due to access denied, see if we need to root override. */ /* Don't do anything fancy for streams. */ if (smb_fname->stream_name) { return -1; } return acl_common_remove_object(handle, smb_fname->base_name, false); } DBG_DEBUG("unlink of %s failed %s\n", smb_fname->base_name, strerror(errno)); return -1; } static int chmod_acl_module_common(struct vfs_handle_struct *handle, const char *path, mode_t mode) { if (lp_posix_pathnames()) { /* Only allow this on POSIX pathnames. */ return SMB_VFS_NEXT_CHMOD(handle, path, mode); } return 0; } static int fchmod_acl_module_common(struct vfs_handle_struct *handle, struct files_struct *fsp, mode_t mode) { if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) { /* Only allow this on POSIX opens. */ return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode); } return 0; } static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle, const char *name, mode_t mode) { if (lp_posix_pathnames()) { /* Only allow this on POSIX pathnames. */ return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode); } return 0; } static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle, struct files_struct *fsp, mode_t mode) { if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) { /* Only allow this on POSIX opens. */ return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode); } return 0; }