/* * fs/cifs/smb2misc.c * * Copyright (C) International Business Machines Corp., 2002,2011 * Etersoft, 2012 * Author(s): Steve French (sfrench@us.ibm.com) * Pavel Shilovsky (pshilovsky@samba.org) 2012 * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * 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 <linux/ctype.h> #include "smb2pdu.h" #include "cifsglob.h" #include "cifsproto.h" #include "smb2proto.h" #include "cifs_debug.h" #include "cifs_unicode.h" #include "smb2status.h" static int check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid) { /* * Make sure that this really is an SMB, that it is a response, * and that the message ids match. */ if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) && (mid == hdr->MessageId)) { if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR) return 0; else { /* only one valid case where server sends us request */ if (hdr->Command == SMB2_OPLOCK_BREAK) return 0; else cERROR(1, "Received Request not response"); } } else { /* bad signature or mid */ if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER) cERROR(1, "Bad protocol string signature header %x", *(unsigned int *) hdr->ProtocolId); if (mid != hdr->MessageId) cERROR(1, "Mids do not match: %llu and %llu", mid, hdr->MessageId); } cERROR(1, "Bad SMB detected. The Mid=%llu", hdr->MessageId); return 1; } /* * The following table defines the expected "StructureSize" of SMB2 responses * in order by SMB2 command. This is similar to "wct" in SMB/CIFS responses. * * Note that commands are defined in smb2pdu.h in le16 but the array below is * indexed by command in host byte order */ static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { /* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65), /* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9), /* SMB2_LOGOFF */ __constant_cpu_to_le16(4), /* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16), /* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4), /* SMB2_CREATE */ __constant_cpu_to_le16(89), /* SMB2_CLOSE */ __constant_cpu_to_le16(60), /* SMB2_FLUSH */ __constant_cpu_to_le16(4), /* SMB2_READ */ __constant_cpu_to_le16(17), /* SMB2_WRITE */ __constant_cpu_to_le16(17), /* SMB2_LOCK */ __constant_cpu_to_le16(4), /* SMB2_IOCTL */ __constant_cpu_to_le16(49), /* BB CHECK this ... not listed in documentation */ /* SMB2_CANCEL */ __constant_cpu_to_le16(0), /* SMB2_ECHO */ __constant_cpu_to_le16(4), /* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9), /* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9), /* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9), /* SMB2_SET_INFO */ __constant_cpu_to_le16(2), /* BB FIXME can also be 44 for lease break */ /* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24) }; int smb2_check_message(char *buf, unsigned int length) { struct smb2_hdr *hdr = (struct smb2_hdr *)buf; struct smb2_pdu *pdu = (struct smb2_pdu *)hdr; __u64 mid = hdr->MessageId; __u32 len = get_rfc1002_length(buf); __u32 clc_len; /* calculated length */ int command; /* BB disable following printk later */ cFYI(1, "%s length: 0x%x, smb_buf_length: 0x%x", __func__, length, len); /* * Add function to do table lookup of StructureSize by command * ie Validate the wct via smb2_struct_sizes table above */ if (length < sizeof(struct smb2_pdu)) { if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) { pdu->StructureSize2 = 0; /* * As with SMB/CIFS, on some error cases servers may * not return wct properly */ return 0; } else { cERROR(1, "Length less than SMB header size"); } return 1; } if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) { cERROR(1, "SMB length greater than maximum, mid=%llu", mid); return 1; } if (check_smb2_hdr(hdr, mid)) return 1; if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) { cERROR(1, "Illegal structure size %u", le16_to_cpu(hdr->StructureSize)); return 1; } command = le16_to_cpu(hdr->Command); if (command >= NUMBER_OF_SMB2_COMMANDS) { cERROR(1, "Illegal SMB2 command %d", command); return 1; } if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) { if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 || pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) { /* error packets have 9 byte structure size */ cERROR(1, "Illegal response size %u for command %d", le16_to_cpu(pdu->StructureSize2), command); return 1; } else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0) && (le16_to_cpu(pdu->StructureSize2) != 44) && (le16_to_cpu(pdu->StructureSize2) != 36)) { /* special case for SMB2.1 lease break message */ cERROR(1, "Illegal response size %d for oplock break", le16_to_cpu(pdu->StructureSize2)); return 1; } } if (4 + len != length) { cERROR(1, "Total length %u RFC1002 length %u mismatch mid %llu", length, 4 + len, mid); return 1; } clc_len = smb2_calc_size(hdr); if (4 + len != clc_len) { cFYI(1, "Calculated size %u length %u mismatch mid %llu", clc_len, 4 + len, mid); /* Windows 7 server returns 24 bytes more */ if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE) return 0; /* server can return one byte more */ if (clc_len == 4 + len + 1) return 0; return 1; } return 0; } /* * The size of the variable area depends on the offset and length fields * located in different fields for various SMB2 responses. SMB2 responses * with no variable length info, show an offset of zero for the offset field. */ static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = { /* SMB2_NEGOTIATE */ true, /* SMB2_SESSION_SETUP */ true, /* SMB2_LOGOFF */ false, /* SMB2_TREE_CONNECT */ false, /* SMB2_TREE_DISCONNECT */ false, /* SMB2_CREATE */ true, /* SMB2_CLOSE */ false, /* SMB2_FLUSH */ false, /* SMB2_READ */ true, /* SMB2_WRITE */ false, /* SMB2_LOCK */ false, /* SMB2_IOCTL */ true, /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */ /* SMB2_ECHO */ false, /* SMB2_QUERY_DIRECTORY */ true, /* SMB2_CHANGE_NOTIFY */ true, /* SMB2_QUERY_INFO */ true, /* SMB2_SET_INFO */ false, /* SMB2_OPLOCK_BREAK */ false }; /* * Returns the pointer to the beginning of the data area. Length of the data * area and the offset to it (from the beginning of the smb are also returned. */ char * smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr) { *off = 0; *len = 0; /* error responses do not have data area */ if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED && (((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2) return NULL; /* * Following commands have data areas so we have to get the location * of the data buffer offset and data buffer length for the particular * command. */ switch (hdr->Command) { case SMB2_NEGOTIATE: *off = le16_to_cpu( ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset); *len = le16_to_cpu( ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength); break; case SMB2_SESSION_SETUP: *off = le16_to_cpu( ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset); *len = le16_to_cpu( ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength); break; case SMB2_CREATE: *off = le32_to_cpu( ((struct smb2_create_rsp *)hdr)->CreateContextsOffset); *len = le32_to_cpu( ((struct smb2_create_rsp *)hdr)->CreateContextsLength); break; case SMB2_QUERY_INFO: *off = le16_to_cpu( ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset); *len = le32_to_cpu( ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength); break; case SMB2_READ: *off = ((struct smb2_read_rsp *)hdr)->DataOffset; *len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength); break; case SMB2_QUERY_DIRECTORY: *off = le16_to_cpu( ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset); *len = le32_to_cpu( ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength); break; case SMB2_IOCTL: case SMB2_CHANGE_NOTIFY: default: /* BB FIXME for unimplemented cases above */ cERROR(1, "no length check for command"); break; } /* * Invalid length or offset probably means data area is invalid, but * we have little choice but to ignore the data area in this case. */ if (*off > 4096) { cERROR(1, "offset %d too large, data area ignored", *off); *len = 0; *off = 0; } else if (*off < 0) { cERROR(1, "negative offset %d to data invalid ignore data area", *off); *off = 0; *len = 0; } else if (*len < 0) { cERROR(1, "negative data length %d invalid, data area ignored", *len); *len = 0; } else if (*len > 128 * 1024) { cERROR(1, "data area larger than 128K: %d", *len); *len = 0; } /* return pointer to beginning of data area, ie offset from SMB start */ if ((*off != 0) && (*len != 0)) return hdr->ProtocolId + *off; else return NULL; } /* * Calculate the size of the SMB message based on the fixed header * portion, the number of word parameters and the data portion of the message. */ unsigned int smb2_calc_size(void *buf) { struct smb2_hdr *hdr = (struct smb2_hdr *)buf; struct smb2_pdu *pdu = (struct smb2_pdu *)hdr; int offset; /* the offset from the beginning of SMB to data area */ int data_length; /* the length of the variable length data area */ /* Structure Size has already been checked to make sure it is 64 */ int len = 4 + le16_to_cpu(pdu->hdr.StructureSize); /* * StructureSize2, ie length of fixed parameter area has already * been checked to make sure it is the correct length. */ len += le16_to_cpu(pdu->StructureSize2); if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false) goto calc_size_exit; smb2_get_data_area_len(&offset, &data_length, hdr); cFYI(1, "SMB2 data length %d offset %d", data_length, offset); if (data_length > 0) { /* * Check to make sure that data area begins after fixed area, * Note that last byte of the fixed area is part of data area * for some commands, typically those with odd StructureSize, * so we must add one to the calculation (and 4 to account for * the size of the RFC1001 hdr. */ if (offset + 4 + 1 < len) { cERROR(1, "data area offset %d overlaps SMB2 header %d", offset + 4 + 1, len); data_length = 0; } else { len = 4 + offset + data_length; } } calc_size_exit: cFYI(1, "SMB2 len %d", len); return len; } /* Note: caller must free return buffer */ __le16 * cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb) { int len; const char *start_of_path; __le16 *to; /* Windows doesn't allow paths beginning with \ */ if (from[0] == '\\') start_of_path = from + 1; else start_of_path = from; to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); return to; } __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode) { if (cinode->clientCanCacheAll) return SMB2_LEASE_WRITE_CACHING | SMB2_LEASE_READ_CACHING; else if (cinode->clientCanCacheRead) return SMB2_LEASE_READ_CACHING; return 0; } __u8 smb2_map_lease_to_oplock(__le32 lease_state) { if (lease_state & SMB2_LEASE_WRITE_CACHING) { if (lease_state & SMB2_LEASE_HANDLE_CACHING) return SMB2_OPLOCK_LEVEL_BATCH; else return SMB2_OPLOCK_LEVEL_EXCLUSIVE; } else if (lease_state & SMB2_LEASE_READ_CACHING) return SMB2_OPLOCK_LEVEL_II; return 0; } struct smb2_lease_break_work { struct work_struct lease_break; struct tcon_link *tlink; __u8 lease_key[16]; __le32 lease_state; }; static void cifs_ses_oplock_break(struct work_struct *work) { struct smb2_lease_break_work *lw = container_of(work, struct smb2_lease_break_work, lease_break); int rc; rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key, lw->lease_state); cFYI(1, "Lease release rc %d", rc); cifs_put_tlink(lw->tlink); kfree(lw); } static bool smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server) { struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer; struct list_head *tmp, *tmp1, *tmp2; struct cifs_ses *ses; struct cifs_tcon *tcon; struct cifsInodeInfo *cinode; struct cifsFileInfo *cfile; struct cifs_pending_open *open; struct smb2_lease_break_work *lw; bool found; int ack_req = le32_to_cpu(rsp->Flags & SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED); lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL); if (!lw) { cERROR(1, "Memory allocation failed during lease break check"); return false; } INIT_WORK(&lw->lease_break, cifs_ses_oplock_break); lw->lease_state = rsp->NewLeaseState; cFYI(1, "Checking for lease break"); /* look up tcon based on tid & uid */ spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &server->smb_ses_list) { ses = list_entry(tmp, struct cifs_ses, smb_ses_list); spin_lock(&cifs_file_list_lock); list_for_each(tmp1, &ses->tcon_list) { tcon = list_entry(tmp1, struct cifs_tcon, tcon_list); cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); list_for_each(tmp2, &tcon->openFileList) { cfile = list_entry(tmp2, struct cifsFileInfo, tlist); cinode = CIFS_I(cfile->dentry->d_inode); if (memcmp(cinode->lease_key, rsp->LeaseKey, SMB2_LEASE_KEY_SIZE)) continue; cFYI(1, "found in the open list"); cFYI(1, "lease key match, lease break 0x%d", le32_to_cpu(rsp->NewLeaseState)); smb2_set_oplock_level(cinode, smb2_map_lease_to_oplock(rsp->NewLeaseState)); if (ack_req) cfile->oplock_break_cancelled = false; else cfile->oplock_break_cancelled = true; queue_work(cifsiod_wq, &cfile->oplock_break); spin_unlock(&cifs_file_list_lock); spin_unlock(&cifs_tcp_ses_lock); return true; } found = false; list_for_each_entry(open, &tcon->pending_opens, olist) { if (memcmp(open->lease_key, rsp->LeaseKey, SMB2_LEASE_KEY_SIZE)) continue; if (!found && ack_req) { found = true; memcpy(lw->lease_key, open->lease_key, SMB2_LEASE_KEY_SIZE); lw->tlink = cifs_get_tlink(open->tlink); queue_work(cifsiod_wq, &lw->lease_break); } cFYI(1, "found in the pending open list"); cFYI(1, "lease key match, lease break 0x%d", le32_to_cpu(rsp->NewLeaseState)); open->oplock = smb2_map_lease_to_oplock(rsp->NewLeaseState); } if (found) { spin_unlock(&cifs_file_list_lock); spin_unlock(&cifs_tcp_ses_lock); return true; } } spin_unlock(&cifs_file_list_lock); } spin_unlock(&cifs_tcp_ses_lock); kfree(lw); cFYI(1, "Can not process lease break - no lease matched"); return false; } bool smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server) { struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer; struct list_head *tmp, *tmp1, *tmp2; struct cifs_ses *ses; struct cifs_tcon *tcon; struct cifsInodeInfo *cinode; struct cifsFileInfo *cfile; cFYI(1, "Checking for oplock break"); if (rsp->hdr.Command != SMB2_OPLOCK_BREAK) return false; if (rsp->StructureSize != smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) { if (le16_to_cpu(rsp->StructureSize) == 44) return smb2_is_valid_lease_break(buffer, server); else return false; } cFYI(1, "oplock level 0x%d", rsp->OplockLevel); /* look up tcon based on tid & uid */ spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &server->smb_ses_list) { ses = list_entry(tmp, struct cifs_ses, smb_ses_list); list_for_each(tmp1, &ses->tcon_list) { tcon = list_entry(tmp1, struct cifs_tcon, tcon_list); cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); spin_lock(&cifs_file_list_lock); list_for_each(tmp2, &tcon->openFileList) { cfile = list_entry(tmp2, struct cifsFileInfo, tlist); if (rsp->PersistentFid != cfile->fid.persistent_fid || rsp->VolatileFid != cfile->fid.volatile_fid) continue; cFYI(1, "file id match, oplock break"); cinode = CIFS_I(cfile->dentry->d_inode); if (!cinode->clientCanCacheAll && rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE) cfile->oplock_break_cancelled = true; else cfile->oplock_break_cancelled = false; smb2_set_oplock_level(cinode, rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0); queue_work(cifsiod_wq, &cfile->oplock_break); spin_unlock(&cifs_file_list_lock); spin_unlock(&cifs_tcp_ses_lock); return true; } spin_unlock(&cifs_file_list_lock); spin_unlock(&cifs_tcp_ses_lock); cFYI(1, "No matching file for oplock break"); return true; } } spin_unlock(&cifs_tcp_ses_lock); cFYI(1, "Can not process oplock break for non-existent connection"); return false; }