// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2018 Samsung Electronics Co., Ltd. * Copyright (C) 2018 Namjae Jeon */ #include #include "smb_common.h" #include "server.h" #include "misc.h" #include "smbstatus.h" #include "connection.h" #include "ksmbd_work.h" #include "mgmt/user_session.h" #include "mgmt/user_config.h" #include "mgmt/tree_connect.h" #include "mgmt/share_config.h" /*for shortname implementation */ static const char basechars[43] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_-!@#$%"; #define MANGLE_BASE (sizeof(basechars) / sizeof(char) - 1) #define MAGIC_CHAR '~' #define PERIOD '.' #define mangle(V) ((char)(basechars[(V) % MANGLE_BASE])) struct smb_protocol { int index; char *name; char *prot; __u16 prot_id; }; static struct smb_protocol smb1_protos[] = { { SMB21_PROT, "\2SMB 2.1", "SMB2_10", SMB21_PROT_ID }, { SMB2X_PROT, "\2SMB 2.???", "SMB2_22", SMB2X_PROT_ID }, }; static struct smb_protocol smb2_protos[] = { { SMB21_PROT, "\2SMB 2.1", "SMB2_10", SMB21_PROT_ID }, { SMB30_PROT, "\2SMB 3.0", "SMB3_00", SMB30_PROT_ID }, { SMB302_PROT, "\2SMB 3.02", "SMB3_02", SMB302_PROT_ID }, { SMB311_PROT, "\2SMB 3.1.1", "SMB3_11", SMB311_PROT_ID }, }; unsigned int ksmbd_server_side_copy_max_chunk_count(void) { return 256; } unsigned int ksmbd_server_side_copy_max_chunk_size(void) { return (2U << 30) - 1; } unsigned int ksmbd_server_side_copy_max_total_size(void) { return (2U << 30) - 1; } inline int ksmbd_min_protocol(void) { return SMB21_PROT; } inline int ksmbd_max_protocol(void) { return SMB311_PROT; } int ksmbd_lookup_protocol_idx(char *str) { int offt = ARRAY_SIZE(smb1_protos) - 1; int len = strlen(str); while (offt >= 0) { if (!strncmp(str, smb1_protos[offt].prot, len)) { ksmbd_debug(SMB, "selected %s dialect idx = %d\n", smb1_protos[offt].prot, offt); return smb1_protos[offt].index; } offt--; } offt = ARRAY_SIZE(smb2_protos) - 1; while (offt >= 0) { if (!strncmp(str, smb2_protos[offt].prot, len)) { ksmbd_debug(SMB, "selected %s dialect idx = %d\n", smb2_protos[offt].prot, offt); return smb2_protos[offt].index; } offt--; } return -1; } /** * ksmbd_verify_smb_message() - check for valid smb2 request header * @work: smb work * * check for valid smb signature and packet direction(request/response) * * Return: 0 on success, otherwise -EINVAL */ int ksmbd_verify_smb_message(struct ksmbd_work *work) { struct smb2_hdr *smb2_hdr = ksmbd_req_buf_next(work); struct smb_hdr *hdr; if (smb2_hdr->ProtocolId == SMB2_PROTO_NUMBER) return ksmbd_smb2_check_message(work); hdr = work->request_buf; if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER && hdr->Command == SMB_COM_NEGOTIATE) { work->conn->outstanding_credits++; return 0; } return -EINVAL; } /** * ksmbd_smb_request() - check for valid smb request type * @conn: connection instance * * Return: true on success, otherwise false */ bool ksmbd_smb_request(struct ksmbd_conn *conn) { __le32 *proto; if (conn->request_buf[0] != 0) return false; proto = (__le32 *)smb2_get_msg(conn->request_buf); if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) { pr_err_ratelimited("smb2 compression not support yet"); return false; } if (*proto != SMB1_PROTO_NUMBER && *proto != SMB2_PROTO_NUMBER && *proto != SMB2_TRANSFORM_PROTO_NUM) return false; return true; } static bool supported_protocol(int idx) { if (idx == SMB2X_PROT && (server_conf.min_protocol >= SMB21_PROT || server_conf.max_protocol <= SMB311_PROT)) return true; return (server_conf.min_protocol <= idx && idx <= server_conf.max_protocol); } static char *next_dialect(char *dialect, int *next_off, int bcount) { dialect = dialect + *next_off; *next_off = strnlen(dialect, bcount); if (dialect[*next_off] != '\0') return NULL; return dialect; } static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count) { int i, seq_num, bcount, next; char *dialect; for (i = ARRAY_SIZE(smb1_protos) - 1; i >= 0; i--) { seq_num = 0; next = 0; dialect = cli_dialects; bcount = le16_to_cpu(byte_count); do { dialect = next_dialect(dialect, &next, bcount); if (!dialect) break; ksmbd_debug(SMB, "client requested dialect %s\n", dialect); if (!strcmp(dialect, smb1_protos[i].name)) { if (supported_protocol(smb1_protos[i].index)) { ksmbd_debug(SMB, "selected %s dialect\n", smb1_protos[i].name); if (smb1_protos[i].index == SMB1_PROT) return seq_num; return smb1_protos[i].prot_id; } } seq_num++; bcount -= (++next); } while (bcount > 0); } return BAD_PROT_ID; } int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count) { int i; int count; for (i = ARRAY_SIZE(smb2_protos) - 1; i >= 0; i--) { count = le16_to_cpu(dialects_count); while (--count >= 0) { ksmbd_debug(SMB, "client requested dialect 0x%x\n", le16_to_cpu(cli_dialects[count])); if (le16_to_cpu(cli_dialects[count]) != smb2_protos[i].prot_id) continue; if (supported_protocol(smb2_protos[i].index)) { ksmbd_debug(SMB, "selected %s dialect\n", smb2_protos[i].name); return smb2_protos[i].prot_id; } } } return BAD_PROT_ID; } static int ksmbd_negotiate_smb_dialect(void *buf) { int smb_buf_length = get_rfc1002_len(buf); __le32 proto = ((struct smb2_hdr *)smb2_get_msg(buf))->ProtocolId; if (proto == SMB2_PROTO_NUMBER) { struct smb2_negotiate_req *req; int smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects); req = (struct smb2_negotiate_req *)smb2_get_msg(buf); if (smb2_neg_size > smb_buf_length) goto err_out; if (struct_size(req, Dialects, le16_to_cpu(req->DialectCount)) > smb_buf_length) goto err_out; return ksmbd_lookup_dialect_by_id(req->Dialects, req->DialectCount); } proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol; if (proto == SMB1_PROTO_NUMBER) { struct smb_negotiate_req *req; req = (struct smb_negotiate_req *)buf; if (le16_to_cpu(req->ByteCount) < 2) goto err_out; if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 + le16_to_cpu(req->ByteCount) > smb_buf_length) { goto err_out; } return ksmbd_lookup_dialect_by_name(req->DialectsArray, req->ByteCount); } err_out: return BAD_PROT_ID; } #define SMB_COM_NEGOTIATE_EX 0x0 /** * get_smb1_cmd_val() - get smb command value from smb header * @work: smb work containing smb header * * Return: smb command value */ static u16 get_smb1_cmd_val(struct ksmbd_work *work) { return SMB_COM_NEGOTIATE_EX; } /** * init_smb1_rsp_hdr() - initialize smb negotiate response header * @work: smb work containing smb request * * Return: 0 on success, otherwise -EINVAL */ static int init_smb1_rsp_hdr(struct ksmbd_work *work) { struct smb_hdr *rsp_hdr = (struct smb_hdr *)work->response_buf; struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf; rsp_hdr->Command = SMB_COM_NEGOTIATE; *(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER; rsp_hdr->Flags = SMBFLG_RESPONSE; rsp_hdr->Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS | SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME; rsp_hdr->Pid = rcv_hdr->Pid; rsp_hdr->Mid = rcv_hdr->Mid; return 0; } /** * smb1_check_user_session() - check for valid session for a user * @work: smb work containing smb request buffer * * Return: 0 on success, otherwise error */ static int smb1_check_user_session(struct ksmbd_work *work) { unsigned int cmd = work->conn->ops->get_cmd_val(work); if (cmd == SMB_COM_NEGOTIATE_EX) return 0; return -EINVAL; } /** * smb1_allocate_rsp_buf() - allocate response buffer for a command * @work: smb work containing smb request * * Return: 0 on success, otherwise -ENOMEM */ static int smb1_allocate_rsp_buf(struct ksmbd_work *work) { work->response_buf = kzalloc(MAX_CIFS_SMALL_BUFFER_SIZE, GFP_KERNEL); work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE; if (!work->response_buf) { pr_err("Failed to allocate %u bytes buffer\n", MAX_CIFS_SMALL_BUFFER_SIZE); return -ENOMEM; } return 0; } /** * set_smb1_rsp_status() - set error type in smb response header * @work: smb work containing smb response header * @err: error code to set in response */ static void set_smb1_rsp_status(struct ksmbd_work *work, __le32 err) { work->send_no_response = 1; } static struct smb_version_ops smb1_server_ops = { .get_cmd_val = get_smb1_cmd_val, .init_rsp_hdr = init_smb1_rsp_hdr, .allocate_rsp_buf = smb1_allocate_rsp_buf, .check_user_session = smb1_check_user_session, .set_rsp_status = set_smb1_rsp_status, }; static int smb1_negotiate(struct ksmbd_work *work) { return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE); } static struct smb_version_cmds smb1_server_cmds[1] = { [SMB_COM_NEGOTIATE_EX] = { .proc = smb1_negotiate, }, }; static int init_smb1_server(struct ksmbd_conn *conn) { conn->ops = &smb1_server_ops; conn->cmds = smb1_server_cmds; conn->max_cmds = ARRAY_SIZE(smb1_server_cmds); return 0; } int ksmbd_init_smb_server(struct ksmbd_work *work) { struct ksmbd_conn *conn = work->conn; __le32 proto; proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol; if (conn->need_neg == false) { if (proto == SMB1_PROTO_NUMBER) return -EINVAL; return 0; } if (proto == SMB1_PROTO_NUMBER) return init_smb1_server(conn); return init_smb3_11_server(conn); } int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level, struct ksmbd_file *dir, struct ksmbd_dir_info *d_info, char *search_pattern, int (*fn)(struct ksmbd_conn *, int, struct ksmbd_dir_info *, struct ksmbd_kstat *)) { int i, rc = 0; struct ksmbd_conn *conn = work->conn; struct mnt_idmap *idmap = file_mnt_idmap(dir->filp); for (i = 0; i < 2; i++) { struct kstat kstat; struct ksmbd_kstat ksmbd_kstat; struct dentry *dentry; if (!dir->dot_dotdot[i]) { /* fill dot entry info */ if (i == 0) { d_info->name = "."; d_info->name_len = 1; dentry = dir->filp->f_path.dentry; } else { d_info->name = ".."; d_info->name_len = 2; dentry = dir->filp->f_path.dentry->d_parent; } if (!match_pattern(d_info->name, d_info->name_len, search_pattern)) { dir->dot_dotdot[i] = 1; continue; } ksmbd_kstat.kstat = &kstat; rc = ksmbd_vfs_fill_dentry_attrs(work, idmap, dentry, &ksmbd_kstat); if (rc) break; rc = fn(conn, info_level, d_info, &ksmbd_kstat); if (rc) break; if (d_info->out_buf_len <= 0) break; dir->dot_dotdot[i] = 1; if (d_info->flags & SMB2_RETURN_SINGLE_ENTRY) { d_info->out_buf_len = 0; break; } } } return rc; } /** * ksmbd_extract_shortname() - get shortname from long filename * @conn: connection instance * @longname: source long filename * @shortname: destination short filename * * Return: shortname length or 0 when source long name is '.' or '..' * TODO: Though this function comforms the restriction of 8.3 Filename spec, * but the result is different with Windows 7's one. need to check. */ int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname, char *shortname) { const char *p; char base[9], extension[4]; char out[13] = {0}; int baselen = 0; int extlen = 0, len = 0; unsigned int csum = 0; const unsigned char *ptr; bool dot_present = true; p = longname; if ((*p == '.') || (!(strcmp(p, "..")))) { /*no mangling required */ return 0; } p = strrchr(longname, '.'); if (p == longname) { /*name starts with a dot*/ strscpy(extension, "___", strlen("___")); } else { if (p) { p++; while (*p && extlen < 3) { if (*p != '.') extension[extlen++] = toupper(*p); p++; } extension[extlen] = '\0'; } else { dot_present = false; } } p = longname; if (*p == '.') { p++; longname++; } while (*p && (baselen < 5)) { if (*p != '.') base[baselen++] = toupper(*p); p++; } base[baselen] = MAGIC_CHAR; memcpy(out, base, baselen + 1); ptr = longname; len = strlen(longname); for (; len > 0; len--, ptr++) csum += *ptr; csum = csum % (MANGLE_BASE * MANGLE_BASE); out[baselen + 1] = mangle(csum / MANGLE_BASE); out[baselen + 2] = mangle(csum); out[baselen + 3] = PERIOD; if (dot_present) memcpy(out + baselen + 4, extension, 4); else out[baselen + 4] = '\0'; smbConvertToUTF16((__le16 *)shortname, out, PATH_MAX, conn->local_nls, 0); len = strlen(out) * 2; return len; } static int __smb2_negotiate(struct ksmbd_conn *conn) { return (conn->dialect >= SMB20_PROT_ID && conn->dialect <= SMB311_PROT_ID); } static int smb_handle_negotiate(struct ksmbd_work *work) { struct smb_negotiate_rsp *neg_rsp = work->response_buf; ksmbd_debug(SMB, "Unsupported SMB1 protocol\n"); if (ksmbd_iov_pin_rsp(work, (void *)neg_rsp, sizeof(struct smb_negotiate_rsp) - 4)) return -ENOMEM; neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS; neg_rsp->hdr.WordCount = 1; neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect); neg_rsp->ByteCount = 0; return 0; } int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command) { struct ksmbd_conn *conn = work->conn; int ret; conn->dialect = ksmbd_negotiate_smb_dialect(work->request_buf); ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect); if (command == SMB2_NEGOTIATE_HE) { ret = smb2_handle_negotiate(work); return ret; } if (command == SMB_COM_NEGOTIATE) { if (__smb2_negotiate(conn)) { init_smb3_11_server(conn); init_smb2_neg_rsp(work); ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n"); return 0; } return smb_handle_negotiate(work); } pr_err("Unknown SMB negotiation command: %u\n", command); return -EINVAL; } enum SHARED_MODE_ERRORS { SHARE_DELETE_ERROR, SHARE_READ_ERROR, SHARE_WRITE_ERROR, FILE_READ_ERROR, FILE_WRITE_ERROR, FILE_DELETE_ERROR, }; static const char * const shared_mode_errors[] = { "Current access mode does not permit SHARE_DELETE", "Current access mode does not permit SHARE_READ", "Current access mode does not permit SHARE_WRITE", "Desired access mode does not permit FILE_READ", "Desired access mode does not permit FILE_WRITE", "Desired access mode does not permit FILE_DELETE", }; static void smb_shared_mode_error(int error, struct ksmbd_file *prev_fp, struct ksmbd_file *curr_fp) { ksmbd_debug(SMB, "%s\n", shared_mode_errors[error]); ksmbd_debug(SMB, "Current mode: 0x%x Desired mode: 0x%x\n", prev_fp->saccess, curr_fp->daccess); } int ksmbd_smb_check_shared_mode(struct file *filp, struct ksmbd_file *curr_fp) { int rc = 0; struct ksmbd_file *prev_fp; /* * Lookup fp in master fp list, and check desired access and * shared mode between previous open and current open. */ read_lock(&curr_fp->f_ci->m_lock); list_for_each_entry(prev_fp, &curr_fp->f_ci->m_fp_list, node) { if (file_inode(filp) != file_inode(prev_fp->filp)) continue; if (filp == prev_fp->filp) continue; if (ksmbd_stream_fd(prev_fp) && ksmbd_stream_fd(curr_fp)) if (strcmp(prev_fp->stream.name, curr_fp->stream.name)) continue; if (prev_fp->attrib_only != curr_fp->attrib_only) continue; if (!(prev_fp->saccess & FILE_SHARE_DELETE_LE) && curr_fp->daccess & FILE_DELETE_LE) { smb_shared_mode_error(SHARE_DELETE_ERROR, prev_fp, curr_fp); rc = -EPERM; break; } /* * Only check FILE_SHARE_DELETE if stream opened and * normal file opened. */ if (ksmbd_stream_fd(prev_fp) && !ksmbd_stream_fd(curr_fp)) continue; if (!(prev_fp->saccess & FILE_SHARE_READ_LE) && curr_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE)) { smb_shared_mode_error(SHARE_READ_ERROR, prev_fp, curr_fp); rc = -EPERM; break; } if (!(prev_fp->saccess & FILE_SHARE_WRITE_LE) && curr_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE)) { smb_shared_mode_error(SHARE_WRITE_ERROR, prev_fp, curr_fp); rc = -EPERM; break; } if (prev_fp->daccess & (FILE_EXECUTE_LE | FILE_READ_DATA_LE) && !(curr_fp->saccess & FILE_SHARE_READ_LE)) { smb_shared_mode_error(FILE_READ_ERROR, prev_fp, curr_fp); rc = -EPERM; break; } if (prev_fp->daccess & (FILE_WRITE_DATA_LE | FILE_APPEND_DATA_LE) && !(curr_fp->saccess & FILE_SHARE_WRITE_LE)) { smb_shared_mode_error(FILE_WRITE_ERROR, prev_fp, curr_fp); rc = -EPERM; break; } if (prev_fp->daccess & FILE_DELETE_LE && !(curr_fp->saccess & FILE_SHARE_DELETE_LE)) { smb_shared_mode_error(FILE_DELETE_ERROR, prev_fp, curr_fp); rc = -EPERM; break; } } read_unlock(&curr_fp->f_ci->m_lock); return rc; } bool is_asterisk(char *p) { return p && p[0] == '*'; } int ksmbd_override_fsids(struct ksmbd_work *work) { struct ksmbd_session *sess = work->sess; struct ksmbd_share_config *share = work->tcon->share_conf; struct cred *cred; struct group_info *gi; unsigned int uid; unsigned int gid; uid = user_uid(sess->user); gid = user_gid(sess->user); if (share->force_uid != KSMBD_SHARE_INVALID_UID) uid = share->force_uid; if (share->force_gid != KSMBD_SHARE_INVALID_GID) gid = share->force_gid; cred = prepare_kernel_cred(&init_task); if (!cred) return -ENOMEM; cred->fsuid = make_kuid(&init_user_ns, uid); cred->fsgid = make_kgid(&init_user_ns, gid); gi = groups_alloc(0); if (!gi) { abort_creds(cred); return -ENOMEM; } set_groups(cred, gi); put_group_info(gi); if (!uid_eq(cred->fsuid, GLOBAL_ROOT_UID)) cred->cap_effective = cap_drop_fs_set(cred->cap_effective); WARN_ON(work->saved_cred); work->saved_cred = override_creds(cred); if (!work->saved_cred) { abort_creds(cred); return -EINVAL; } return 0; } void ksmbd_revert_fsids(struct ksmbd_work *work) { const struct cred *cred; WARN_ON(!work->saved_cred); cred = current_cred(); revert_creds(work->saved_cred); put_cred(cred); work->saved_cred = NULL; } __le32 smb_map_generic_desired_access(__le32 daccess) { if (daccess & FILE_GENERIC_READ_LE) { daccess |= cpu_to_le32(GENERIC_READ_FLAGS); daccess &= ~FILE_GENERIC_READ_LE; } if (daccess & FILE_GENERIC_WRITE_LE) { daccess |= cpu_to_le32(GENERIC_WRITE_FLAGS); daccess &= ~FILE_GENERIC_WRITE_LE; } if (daccess & FILE_GENERIC_EXECUTE_LE) { daccess |= cpu_to_le32(GENERIC_EXECUTE_FLAGS); daccess &= ~FILE_GENERIC_EXECUTE_LE; } if (daccess & FILE_GENERIC_ALL_LE) { daccess |= cpu_to_le32(GENERIC_ALL_FLAGS); daccess &= ~FILE_GENERIC_ALL_LE; } return daccess; }