/* * SMB1 (CIFS) version specific operations * * Copyright (c) 2012, Jeff Layton <jlayton@redhat.com> * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License v2 as published * by the Free Software Foundation. * * This library 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "cifsglob.h" #include "cifsproto.h" #include "cifs_debug.h" #include "cifspdu.h" /* * An NT cancel request header looks just like the original request except: * * The Command is SMB_COM_NT_CANCEL * The WordCount is zeroed out * The ByteCount is zeroed out * * This function mangles an existing request buffer into a * SMB_COM_NT_CANCEL request and then sends it. */ static int send_nt_cancel(struct TCP_Server_Info *server, void *buf, struct mid_q_entry *mid) { int rc = 0; struct smb_hdr *in_buf = (struct smb_hdr *)buf; /* -4 for RFC1001 length and +2 for BCC field */ in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4 + 2); in_buf->Command = SMB_COM_NT_CANCEL; in_buf->WordCount = 0; put_bcc(0, in_buf); mutex_lock(&server->srv_mutex); rc = cifs_sign_smb(in_buf, server, &mid->sequence_number); if (rc) { mutex_unlock(&server->srv_mutex); return rc; } rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length)); mutex_unlock(&server->srv_mutex); cFYI(1, "issued NT_CANCEL for mid %u, rc = %d", in_buf->Mid, rc); return rc; } static bool cifs_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2) { return ob1->netfid == ob2->netfid; } static unsigned int cifs_read_data_offset(char *buf) { READ_RSP *rsp = (READ_RSP *)buf; return le16_to_cpu(rsp->DataOffset); } static unsigned int cifs_read_data_length(char *buf) { READ_RSP *rsp = (READ_RSP *)buf; return (le16_to_cpu(rsp->DataLengthHigh) << 16) + le16_to_cpu(rsp->DataLength); } static struct mid_q_entry * cifs_find_mid(struct TCP_Server_Info *server, char *buffer) { struct smb_hdr *buf = (struct smb_hdr *)buffer; struct mid_q_entry *mid; spin_lock(&GlobalMid_Lock); list_for_each_entry(mid, &server->pending_mid_q, qhead) { if (mid->mid == buf->Mid && mid->mid_state == MID_REQUEST_SUBMITTED && le16_to_cpu(mid->command) == buf->Command) { spin_unlock(&GlobalMid_Lock); return mid; } } spin_unlock(&GlobalMid_Lock); return NULL; } static void cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add, const int optype) { spin_lock(&server->req_lock); server->credits += add; server->in_flight--; spin_unlock(&server->req_lock); wake_up(&server->request_q); } static void cifs_set_credits(struct TCP_Server_Info *server, const int val) { spin_lock(&server->req_lock); server->credits = val; server->oplocks = val > 1 ? enable_oplocks : false; spin_unlock(&server->req_lock); } static int * cifs_get_credits_field(struct TCP_Server_Info *server, const int optype) { return &server->credits; } static unsigned int cifs_get_credits(struct mid_q_entry *mid) { return 1; } /* * Find a free multiplex id (SMB mid). Otherwise there could be * mid collisions which might cause problems, demultiplexing the * wrong response to this request. Multiplex ids could collide if * one of a series requests takes much longer than the others, or * if a very large number of long lived requests (byte range * locks or FindNotify requests) are pending. No more than * 64K-1 requests can be outstanding at one time. If no * mids are available, return zero. A future optimization * could make the combination of mids and uid the key we use * to demultiplex on (rather than mid alone). * In addition to the above check, the cifs demultiplex * code already used the command code as a secondary * check of the frame and if signing is negotiated the * response would be discarded if the mid were the same * but the signature was wrong. Since the mid is not put in the * pending queue until later (when it is about to be dispatched) * we do have to limit the number of outstanding requests * to somewhat less than 64K-1 although it is hard to imagine * so many threads being in the vfs at one time. */ static __u64 cifs_get_next_mid(struct TCP_Server_Info *server) { __u64 mid = 0; __u16 last_mid, cur_mid; bool collision; spin_lock(&GlobalMid_Lock); /* mid is 16 bit only for CIFS/SMB */ cur_mid = (__u16)((server->CurrentMid) & 0xffff); /* we do not want to loop forever */ last_mid = cur_mid; cur_mid++; /* * This nested loop looks more expensive than it is. * In practice the list of pending requests is short, * fewer than 50, and the mids are likely to be unique * on the first pass through the loop unless some request * takes longer than the 64 thousand requests before it * (and it would also have to have been a request that * did not time out). */ while (cur_mid != last_mid) { struct mid_q_entry *mid_entry; unsigned int num_mids; collision = false; if (cur_mid == 0) cur_mid++; num_mids = 0; list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) { ++num_mids; if (mid_entry->mid == cur_mid && mid_entry->mid_state == MID_REQUEST_SUBMITTED) { /* This mid is in use, try a different one */ collision = true; break; } } /* * if we have more than 32k mids in the list, then something * is very wrong. Possibly a local user is trying to DoS the * box by issuing long-running calls and SIGKILL'ing them. If * we get to 2^16 mids then we're in big trouble as this * function could loop forever. * * Go ahead and assign out the mid in this situation, but force * an eventual reconnect to clean out the pending_mid_q. */ if (num_mids > 32768) server->tcpStatus = CifsNeedReconnect; if (!collision) { mid = (__u64)cur_mid; server->CurrentMid = mid; break; } cur_mid++; } spin_unlock(&GlobalMid_Lock); return mid; } /* return codes: 0 not a transact2, or all data present >0 transact2 with that much data missing -EINVAL invalid transact2 */ static int check2ndT2(char *buf) { struct smb_hdr *pSMB = (struct smb_hdr *)buf; struct smb_t2_rsp *pSMBt; int remaining; __u16 total_data_size, data_in_this_rsp; if (pSMB->Command != SMB_COM_TRANSACTION2) return 0; /* check for plausible wct, bcc and t2 data and parm sizes */ /* check for parm and data offset going beyond end of smb */ if (pSMB->WordCount != 10) { /* coalesce_t2 depends on this */ cFYI(1, "invalid transact2 word count"); return -EINVAL; } pSMBt = (struct smb_t2_rsp *)pSMB; total_data_size = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount); data_in_this_rsp = get_unaligned_le16(&pSMBt->t2_rsp.DataCount); if (total_data_size == data_in_this_rsp) return 0; else if (total_data_size < data_in_this_rsp) { cFYI(1, "total data %d smaller than data in frame %d", total_data_size, data_in_this_rsp); return -EINVAL; } remaining = total_data_size - data_in_this_rsp; cFYI(1, "missing %d bytes from transact2, check next response", remaining); if (total_data_size > CIFSMaxBufSize) { cERROR(1, "TotalDataSize %d is over maximum buffer %d", total_data_size, CIFSMaxBufSize); return -EINVAL; } return remaining; } static int coalesce_t2(char *second_buf, struct smb_hdr *target_hdr) { struct smb_t2_rsp *pSMBs = (struct smb_t2_rsp *)second_buf; struct smb_t2_rsp *pSMBt = (struct smb_t2_rsp *)target_hdr; char *data_area_of_tgt; char *data_area_of_src; int remaining; unsigned int byte_count, total_in_tgt; __u16 tgt_total_cnt, src_total_cnt, total_in_src; src_total_cnt = get_unaligned_le16(&pSMBs->t2_rsp.TotalDataCount); tgt_total_cnt = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount); if (tgt_total_cnt != src_total_cnt) cFYI(1, "total data count of primary and secondary t2 differ " "source=%hu target=%hu", src_total_cnt, tgt_total_cnt); total_in_tgt = get_unaligned_le16(&pSMBt->t2_rsp.DataCount); remaining = tgt_total_cnt - total_in_tgt; if (remaining < 0) { cFYI(1, "Server sent too much data. tgt_total_cnt=%hu " "total_in_tgt=%hu", tgt_total_cnt, total_in_tgt); return -EPROTO; } if (remaining == 0) { /* nothing to do, ignore */ cFYI(1, "no more data remains"); return 0; } total_in_src = get_unaligned_le16(&pSMBs->t2_rsp.DataCount); if (remaining < total_in_src) cFYI(1, "transact2 2nd response contains too much data"); /* find end of first SMB data area */ data_area_of_tgt = (char *)&pSMBt->hdr.Protocol + get_unaligned_le16(&pSMBt->t2_rsp.DataOffset); /* validate target area */ data_area_of_src = (char *)&pSMBs->hdr.Protocol + get_unaligned_le16(&pSMBs->t2_rsp.DataOffset); data_area_of_tgt += total_in_tgt; total_in_tgt += total_in_src; /* is the result too big for the field? */ if (total_in_tgt > USHRT_MAX) { cFYI(1, "coalesced DataCount too large (%u)", total_in_tgt); return -EPROTO; } put_unaligned_le16(total_in_tgt, &pSMBt->t2_rsp.DataCount); /* fix up the BCC */ byte_count = get_bcc(target_hdr); byte_count += total_in_src; /* is the result too big for the field? */ if (byte_count > USHRT_MAX) { cFYI(1, "coalesced BCC too large (%u)", byte_count); return -EPROTO; } put_bcc(byte_count, target_hdr); byte_count = be32_to_cpu(target_hdr->smb_buf_length); byte_count += total_in_src; /* don't allow buffer to overflow */ if (byte_count > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) { cFYI(1, "coalesced BCC exceeds buffer size (%u)", byte_count); return -ENOBUFS; } target_hdr->smb_buf_length = cpu_to_be32(byte_count); /* copy second buffer into end of first buffer */ memcpy(data_area_of_tgt, data_area_of_src, total_in_src); if (remaining != total_in_src) { /* more responses to go */ cFYI(1, "waiting for more secondary responses"); return 1; } /* we are done */ cFYI(1, "found the last secondary response"); return 0; } static bool cifs_check_trans2(struct mid_q_entry *mid, struct TCP_Server_Info *server, char *buf, int malformed) { if (malformed) return false; if (check2ndT2(buf) <= 0) return false; mid->multiRsp = true; if (mid->resp_buf) { /* merge response - fix up 1st*/ malformed = coalesce_t2(buf, mid->resp_buf); if (malformed > 0) return true; /* All parts received or packet is malformed. */ mid->multiEnd = true; dequeue_mid(mid, malformed); return true; } if (!server->large_buf) { /*FIXME: switch to already allocated largebuf?*/ cERROR(1, "1st trans2 resp needs bigbuf"); } else { /* Have first buffer */ mid->resp_buf = buf; mid->large_buf = true; server->bigbuf = NULL; } return true; } static bool cifs_need_neg(struct TCP_Server_Info *server) { return server->maxBuf == 0; } static int cifs_negotiate(const unsigned int xid, struct cifs_ses *ses) { int rc; rc = CIFSSMBNegotiate(xid, ses); if (rc == -EAGAIN) { /* retry only once on 1st time connection */ set_credits(ses->server, 1); rc = CIFSSMBNegotiate(xid, ses); if (rc == -EAGAIN) rc = -EHOSTDOWN; } return rc; } static void cifs_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon) { CIFSSMBQFSDeviceInfo(xid, tcon); CIFSSMBQFSAttributeInfo(xid, tcon); } static int cifs_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const char *full_path) { int rc; FILE_ALL_INFO *file_info; file_info = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL); if (file_info == NULL) return -ENOMEM; rc = CIFSSMBQPathInfo(xid, tcon, full_path, file_info, 0 /* not legacy */, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc == -EOPNOTSUPP || rc == -EINVAL) rc = SMBQueryInformation(xid, tcon, full_path, file_info, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); kfree(file_info); return rc; } static int cifs_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const char *full_path, FILE_ALL_INFO *data, bool *adjustTZ) { int rc; /* could do find first instead but this returns more info */ rc = CIFSSMBQPathInfo(xid, tcon, full_path, data, 0 /* not legacy */, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); /* * BB optimize code so we do not make the above call when server claims * no NT SMB support and the above call failed at least once - set flag * in tcon or mount. */ if ((rc == -EOPNOTSUPP) || (rc == -EINVAL)) { rc = SMBQueryInformation(xid, tcon, full_path, data, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); *adjustTZ = true; } return rc; } static int cifs_get_srv_inum(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, const char *full_path, u64 *uniqueid, FILE_ALL_INFO *data) { /* * We can not use the IndexNumber field by default from Windows or * Samba (in ALL_INFO buf) but we can request it explicitly. The SNIA * CIFS spec claims that this value is unique within the scope of a * share, and the windows docs hint that it's actually unique * per-machine. * * There may be higher info levels that work but are there Windows * server or network appliances for which IndexNumber field is not * guaranteed unique? */ return CIFSGetSrvInodeNumber(xid, tcon, full_path, uniqueid, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); } static char * cifs_build_path_to_root(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, struct cifs_tcon *tcon) { int pplen = vol->prepath ? strlen(vol->prepath) : 0; int dfsplen; char *full_path = NULL; /* if no prefix path, simply set path to the root of share to "" */ if (pplen == 0) { full_path = kzalloc(1, GFP_KERNEL); return full_path; } if (tcon->Flags & SMB_SHARE_IS_IN_DFS) dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1); else dfsplen = 0; full_path = kmalloc(dfsplen + pplen + 1, GFP_KERNEL); if (full_path == NULL) return full_path; if (dfsplen) strncpy(full_path, tcon->treeName, dfsplen); strncpy(full_path + dfsplen, vol->prepath, pplen); convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb)); full_path[dfsplen + pplen] = 0; /* add trailing null */ return full_path; } struct smb_version_operations smb1_operations = { .send_cancel = send_nt_cancel, .compare_fids = cifs_compare_fids, .setup_request = cifs_setup_request, .setup_async_request = cifs_setup_async_request, .check_receive = cifs_check_receive, .add_credits = cifs_add_credits, .set_credits = cifs_set_credits, .get_credits_field = cifs_get_credits_field, .get_credits = cifs_get_credits, .get_next_mid = cifs_get_next_mid, .read_data_offset = cifs_read_data_offset, .read_data_length = cifs_read_data_length, .map_error = map_smb_to_linux_error, .find_mid = cifs_find_mid, .check_message = checkSMB, .dump_detail = cifs_dump_detail, .is_oplock_break = is_valid_oplock_break, .check_trans2 = cifs_check_trans2, .need_neg = cifs_need_neg, .negotiate = cifs_negotiate, .sess_setup = CIFS_SessSetup, .logoff = CIFSSMBLogoff, .tree_connect = CIFSTCon, .tree_disconnect = CIFSSMBTDis, .get_dfs_refer = CIFSGetDFSRefer, .qfs_tcon = cifs_qfs_tcon, .is_path_accessible = cifs_is_path_accessible, .query_path_info = cifs_query_path_info, .get_srv_inum = cifs_get_srv_inum, .build_path_to_root = cifs_build_path_to_root, }; struct smb_version_values smb1_values = { .version_string = SMB1_VERSION_STRING, .large_lock_type = LOCKING_ANDX_LARGE_FILES, .exclusive_lock_type = 0, .shared_lock_type = LOCKING_ANDX_SHARED_LOCK, .unlock_lock_type = 0, .header_size = sizeof(struct smb_hdr), .max_header_size = MAX_CIFS_HDR_SIZE, .read_rsp_size = sizeof(READ_RSP), .lock_cmd = cpu_to_le16(SMB_COM_LOCKING_ANDX), };