diff options
Diffstat (limited to 'fs/smb/server/smb_common.c')
-rw-r--r-- | fs/smb/server/smb_common.c | 810 |
1 files changed, 810 insertions, 0 deletions
diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c new file mode 100644 index 0000000000..7c98bf6997 --- /dev/null +++ b/fs/smb/server/smb_common.c @@ -0,0 +1,810 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2018 Samsung Electronics Co., Ltd. + * Copyright (C) 2018 Namjae Jeon <linkinjeon@kernel.org> + */ + +#include <linux/user_namespace.h> + +#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; + ksmbd_vfs_fill_dentry_attrs(work, + idmap, + dentry, + &ksmbd_kstat); + 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; +} |