diff options
Diffstat (limited to 'kernel/fs/cifs/smb2misc.c')
| -rw-r--r-- | kernel/fs/cifs/smb2misc.c | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/kernel/fs/cifs/smb2misc.c b/kernel/fs/cifs/smb2misc.c new file mode 100644 index 000000000..1c5907019 --- /dev/null +++ b/kernel/fs/cifs/smb2misc.c @@ -0,0 +1,632 @@ +/* + * 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) +{ + __u64 wire_mid = le64_to_cpu(hdr->MessageId); + + /* + * 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 == wire_mid)) { + 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 + cifs_dbg(VFS, "Received Request not response\n"); + } + } else { /* bad signature or mid */ + if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER) + cifs_dbg(VFS, "Bad protocol string signature header %x\n", + *(unsigned int *) hdr->ProtocolId); + if (mid != wire_mid) + cifs_dbg(VFS, "Mids do not match: %llu and %llu\n", + mid, wire_mid); + } + cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid); + 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 */ cpu_to_le16(65), + /* SMB2_SESSION_SETUP */ cpu_to_le16(9), + /* SMB2_LOGOFF */ cpu_to_le16(4), + /* SMB2_TREE_CONNECT */ cpu_to_le16(16), + /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4), + /* SMB2_CREATE */ cpu_to_le16(89), + /* SMB2_CLOSE */ cpu_to_le16(60), + /* SMB2_FLUSH */ cpu_to_le16(4), + /* SMB2_READ */ cpu_to_le16(17), + /* SMB2_WRITE */ cpu_to_le16(17), + /* SMB2_LOCK */ cpu_to_le16(4), + /* SMB2_IOCTL */ cpu_to_le16(49), + /* BB CHECK this ... not listed in documentation */ + /* SMB2_CANCEL */ cpu_to_le16(0), + /* SMB2_ECHO */ cpu_to_le16(4), + /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9), + /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9), + /* SMB2_QUERY_INFO */ cpu_to_le16(9), + /* SMB2_SET_INFO */ cpu_to_le16(2), + /* BB FIXME can also be 44 for lease break */ + /* SMB2_OPLOCK_BREAK */ 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 = le64_to_cpu(hdr->MessageId); + __u32 len = get_rfc1002_length(buf); + __u32 clc_len; /* calculated length */ + int command; + + /* BB disable following printk later */ + cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n", + __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 { + cifs_dbg(VFS, "Length less than SMB header size\n"); + } + return 1; + } + if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) { + cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n", + mid); + return 1; + } + + if (check_smb2_hdr(hdr, mid)) + return 1; + + if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) { + cifs_dbg(VFS, "Illegal structure size %u\n", + le16_to_cpu(hdr->StructureSize)); + return 1; + } + + command = le16_to_cpu(hdr->Command); + if (command >= NUMBER_OF_SMB2_COMMANDS) { + cifs_dbg(VFS, "Illegal SMB2 command %d\n", 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 */ + cifs_dbg(VFS, "Illegal response size %u for command %d\n", + 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 */ + cifs_dbg(VFS, "Illegal response size %d for oplock break\n", + le16_to_cpu(pdu->StructureSize2)); + return 1; + } + } + + if (4 + len != length) { + cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n", + length, 4 + len, mid); + return 1; + } + + clc_len = smb2_calc_size(hdr); + + if (4 + len != clc_len) { + cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n", + clc_len, 4 + len, mid); + /* create failed on symlink */ + if (command == SMB2_CREATE_HE && + hdr->Status == STATUS_STOPPED_ON_SYMLINK) + return 0; + /* 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 due to implied bcc[0] */ + if (clc_len == 4 + len + 1) + return 0; + + /* + * MacOS server pads after SMB2.1 write response with 3 bytes + * of junk. Other servers match RFC1001 len to actual + * SMB2/SMB3 frame length (header + smb2 response specific data) + * Log the server error (once), but allow it and continue + * since the frame is parseable. + */ + if (clc_len < 4 /* RFC1001 header size */ + len) { + printk_once(KERN_WARNING + "SMB2 server sent bad RFC1001 len %d not %d\n", + len, clc_len - 4); + 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: + *off = le32_to_cpu( + ((struct smb2_ioctl_rsp *)hdr)->OutputOffset); + *len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount); + break; + case SMB2_CHANGE_NOTIFY: + default: + /* BB FIXME for unimplemented cases above */ + cifs_dbg(VFS, "no length check for command\n"); + 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) { + cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off); + *len = 0; + *off = 0; + } else if (*off < 0) { + cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n", + *off); + *off = 0; + *len = 0; + } else if (*len < 0) { + cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n", + *len); + *len = 0; + } else if (*len > 128 * 1024) { + cifs_dbg(VFS, "data area larger than 128K: %d\n", *len); + *len = 0; + } + + /* return pointer to beginning of data area, ie offset from SMB start */ + if ((*off != 0) && (*len != 0)) + return (char *)(&hdr->ProtocolId[0]) + *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); + cifs_dbg(FYI, "SMB2 data length %d offset %d\n", 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) { + cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n", + offset + 4 + 1, len); + data_length = 0; + } else { + len = 4 + offset + data_length; + } + } +calc_size_exit: + cifs_dbg(FYI, "SMB2 len %d\n", 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; + int map_type; + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR) + map_type = SFM_MAP_UNI_RSVD; + else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR) + map_type = SFU_MAP_UNI_RSVD; + else + map_type = NO_MAP_UNI_RSVD; + + /* 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, map_type); + return to; +} + +__le32 +smb2_get_lease_state(struct cifsInodeInfo *cinode) +{ + __le32 lease = 0; + + if (CIFS_CACHE_WRITE(cinode)) + lease |= SMB2_LEASE_WRITE_CACHING; + if (CIFS_CACHE_HANDLE(cinode)) + lease |= SMB2_LEASE_HANDLE_CACHING; + if (CIFS_CACHE_READ(cinode)) + lease |= SMB2_LEASE_READ_CACHING; + return lease; +} + +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); + cifs_dbg(FYI, "Lease release rc %d\n", rc); + cifs_put_tlink(lw->tlink); + kfree(lw); +} + +static bool +smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp, + struct smb2_lease_break_work *lw) +{ + bool found; + __u8 lease_state; + struct list_head *tmp; + struct cifsFileInfo *cfile; + struct TCP_Server_Info *server = tcon->ses->server; + struct cifs_pending_open *open; + struct cifsInodeInfo *cinode; + int ack_req = le32_to_cpu(rsp->Flags & + SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED); + + lease_state = le32_to_cpu(rsp->NewLeaseState); + + list_for_each(tmp, &tcon->openFileList) { + cfile = list_entry(tmp, struct cifsFileInfo, tlist); + cinode = CIFS_I(d_inode(cfile->dentry)); + + if (memcmp(cinode->lease_key, rsp->LeaseKey, + SMB2_LEASE_KEY_SIZE)) + continue; + + cifs_dbg(FYI, "found in the open list\n"); + cifs_dbg(FYI, "lease key match, lease break 0x%x\n", + le32_to_cpu(rsp->NewLeaseState)); + + server->ops->set_oplock_level(cinode, lease_state, 0, NULL); + + if (ack_req) + cfile->oplock_break_cancelled = false; + else + cfile->oplock_break_cancelled = true; + + queue_work(cifsiod_wq, &cfile->oplock_break); + kfree(lw); + 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); + } + + cifs_dbg(FYI, "found in the pending open list\n"); + cifs_dbg(FYI, "lease key match, lease break 0x%x\n", + le32_to_cpu(rsp->NewLeaseState)); + + open->oplock = lease_state; + } + return found; +} + +static bool +smb2_is_valid_lease_break(char *buffer) +{ + struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer; + struct list_head *tmp, *tmp1, *tmp2; + struct TCP_Server_Info *server; + struct cifs_ses *ses; + struct cifs_tcon *tcon; + struct smb2_lease_break_work *lw; + + lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL); + if (!lw) + return false; + + INIT_WORK(&lw->lease_break, cifs_ses_oplock_break); + lw->lease_state = rsp->NewLeaseState; + + cifs_dbg(FYI, "Checking for lease break\n"); + + /* look up tcon based on tid & uid */ + spin_lock(&cifs_tcp_ses_lock); + list_for_each(tmp, &cifs_tcp_ses_list) { + server = list_entry(tmp, struct TCP_Server_Info, tcp_ses_list); + + list_for_each(tmp1, &server->smb_ses_list) { + ses = list_entry(tmp1, struct cifs_ses, smb_ses_list); + + spin_lock(&cifs_file_list_lock); + list_for_each(tmp2, &ses->tcon_list) { + tcon = list_entry(tmp2, struct cifs_tcon, + tcon_list); + cifs_stats_inc( + &tcon->stats.cifs_stats.num_oplock_brks); + if (smb2_tcon_has_lease(tcon, rsp, lw)) { + 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); + cifs_dbg(FYI, "Can not process lease break - no lease matched\n"); + 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; + + cifs_dbg(FYI, "Checking for oplock break\n"); + + 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); + else + return false; + } + + cifs_dbg(FYI, "oplock level 0x%x\n", 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; + + cifs_dbg(FYI, "file id match, oplock break\n"); + cinode = CIFS_I(d_inode(cfile->dentry)); + + if (!CIFS_CACHE_WRITE(cinode) && + rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE) + cfile->oplock_break_cancelled = true; + else + cfile->oplock_break_cancelled = false; + + set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, + &cinode->flags); + + /* + * Set flag if the server downgrades the oplock + * to L2 else clear. + */ + if (rsp->OplockLevel) + set_bit( + CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, + &cinode->flags); + else + clear_bit( + CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, + &cinode->flags); + + 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); + cifs_dbg(FYI, "No matching file for oplock break\n"); + return true; + } + } + spin_unlock(&cifs_tcp_ses_lock); + cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); + return false; +} |