diff options
Diffstat (limited to 'kernel/fs/cifs/misc.c')
| -rw-r--r-- | kernel/fs/cifs/misc.c | 641 |
1 files changed, 641 insertions, 0 deletions
diff --git a/kernel/fs/cifs/misc.c b/kernel/fs/cifs/misc.c new file mode 100644 index 000000000..8442b8b8e --- /dev/null +++ b/kernel/fs/cifs/misc.c @@ -0,0 +1,641 @@ +/* + * fs/cifs/misc.c + * + * Copyright (C) International Business Machines Corp., 2002,2008 + * Author(s): Steve French (sfrench@us.ibm.com) + * + * 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/slab.h> +#include <linux/ctype.h> +#include <linux/mempool.h> +#include "cifspdu.h" +#include "cifsglob.h" +#include "cifsproto.h" +#include "cifs_debug.h" +#include "smberr.h" +#include "nterr.h" +#include "cifs_unicode.h" +#ifdef CONFIG_CIFS_SMB2 +#include "smb2pdu.h" +#endif + +extern mempool_t *cifs_sm_req_poolp; +extern mempool_t *cifs_req_poolp; + +/* The xid serves as a useful identifier for each incoming vfs request, + in a similar way to the mid which is useful to track each sent smb, + and CurrentXid can also provide a running counter (although it + will eventually wrap past zero) of the total vfs operations handled + since the cifs fs was mounted */ + +unsigned int +_get_xid(void) +{ + unsigned int xid; + + spin_lock(&GlobalMid_Lock); + GlobalTotalActiveXid++; + + /* keep high water mark for number of simultaneous ops in filesystem */ + if (GlobalTotalActiveXid > GlobalMaxActiveXid) + GlobalMaxActiveXid = GlobalTotalActiveXid; + if (GlobalTotalActiveXid > 65000) + cifs_dbg(FYI, "warning: more than 65000 requests active\n"); + xid = GlobalCurrentXid++; + spin_unlock(&GlobalMid_Lock); + return xid; +} + +void +_free_xid(unsigned int xid) +{ + spin_lock(&GlobalMid_Lock); + /* if (GlobalTotalActiveXid == 0) + BUG(); */ + GlobalTotalActiveXid--; + spin_unlock(&GlobalMid_Lock); +} + +struct cifs_ses * +sesInfoAlloc(void) +{ + struct cifs_ses *ret_buf; + + ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL); + if (ret_buf) { + atomic_inc(&sesInfoAllocCount); + ret_buf->status = CifsNew; + ++ret_buf->ses_count; + INIT_LIST_HEAD(&ret_buf->smb_ses_list); + INIT_LIST_HEAD(&ret_buf->tcon_list); + mutex_init(&ret_buf->session_mutex); + } + return ret_buf; +} + +void +sesInfoFree(struct cifs_ses *buf_to_free) +{ + if (buf_to_free == NULL) { + cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n"); + return; + } + + atomic_dec(&sesInfoAllocCount); + kfree(buf_to_free->serverOS); + kfree(buf_to_free->serverDomain); + kfree(buf_to_free->serverNOS); + if (buf_to_free->password) { + memset(buf_to_free->password, 0, strlen(buf_to_free->password)); + kfree(buf_to_free->password); + } + kfree(buf_to_free->user_name); + kfree(buf_to_free->domainName); + kfree(buf_to_free->auth_key.response); + kfree(buf_to_free); +} + +struct cifs_tcon * +tconInfoAlloc(void) +{ + struct cifs_tcon *ret_buf; + ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL); + if (ret_buf) { + atomic_inc(&tconInfoAllocCount); + ret_buf->tidStatus = CifsNew; + ++ret_buf->tc_count; + INIT_LIST_HEAD(&ret_buf->openFileList); + INIT_LIST_HEAD(&ret_buf->tcon_list); +#ifdef CONFIG_CIFS_STATS + spin_lock_init(&ret_buf->stat_lock); +#endif + } + return ret_buf; +} + +void +tconInfoFree(struct cifs_tcon *buf_to_free) +{ + if (buf_to_free == NULL) { + cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n"); + return; + } + atomic_dec(&tconInfoAllocCount); + kfree(buf_to_free->nativeFileSystem); + if (buf_to_free->password) { + memset(buf_to_free->password, 0, strlen(buf_to_free->password)); + kfree(buf_to_free->password); + } + kfree(buf_to_free); +} + +struct smb_hdr * +cifs_buf_get(void) +{ + struct smb_hdr *ret_buf = NULL; + size_t buf_size = sizeof(struct smb_hdr); + +#ifdef CONFIG_CIFS_SMB2 + /* + * SMB2 header is bigger than CIFS one - no problems to clean some + * more bytes for CIFS. + */ + buf_size = sizeof(struct smb2_hdr); +#endif + /* + * We could use negotiated size instead of max_msgsize - + * but it may be more efficient to always alloc same size + * albeit slightly larger than necessary and maxbuffersize + * defaults to this and can not be bigger. + */ + ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS); + + /* clear the first few header bytes */ + /* for most paths, more is cleared in header_assemble */ + if (ret_buf) { + memset(ret_buf, 0, buf_size + 3); + atomic_inc(&bufAllocCount); +#ifdef CONFIG_CIFS_STATS2 + atomic_inc(&totBufAllocCount); +#endif /* CONFIG_CIFS_STATS2 */ + } + + return ret_buf; +} + +void +cifs_buf_release(void *buf_to_free) +{ + if (buf_to_free == NULL) { + /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/ + return; + } + mempool_free(buf_to_free, cifs_req_poolp); + + atomic_dec(&bufAllocCount); + return; +} + +struct smb_hdr * +cifs_small_buf_get(void) +{ + struct smb_hdr *ret_buf = NULL; + +/* We could use negotiated size instead of max_msgsize - + but it may be more efficient to always alloc same size + albeit slightly larger than necessary and maxbuffersize + defaults to this and can not be bigger */ + ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS); + if (ret_buf) { + /* No need to clear memory here, cleared in header assemble */ + /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/ + atomic_inc(&smBufAllocCount); +#ifdef CONFIG_CIFS_STATS2 + atomic_inc(&totSmBufAllocCount); +#endif /* CONFIG_CIFS_STATS2 */ + + } + return ret_buf; +} + +void +cifs_small_buf_release(void *buf_to_free) +{ + + if (buf_to_free == NULL) { + cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n"); + return; + } + mempool_free(buf_to_free, cifs_sm_req_poolp); + + atomic_dec(&smBufAllocCount); + return; +} + +void +free_rsp_buf(int resp_buftype, void *rsp) +{ + if (resp_buftype == CIFS_SMALL_BUFFER) + cifs_small_buf_release(rsp); + else if (resp_buftype == CIFS_LARGE_BUFFER) + cifs_buf_release(rsp); +} + +/* NB: MID can not be set if treeCon not passed in, in that + case it is responsbility of caller to set the mid */ +void +header_assemble(struct smb_hdr *buffer, char smb_command /* command */ , + const struct cifs_tcon *treeCon, int word_count + /* length of fixed section (word count) in two byte units */) +{ + char *temp = (char *) buffer; + + memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */ + + buffer->smb_buf_length = cpu_to_be32( + (2 * word_count) + sizeof(struct smb_hdr) - + 4 /* RFC 1001 length field does not count */ + + 2 /* for bcc field itself */) ; + + buffer->Protocol[0] = 0xFF; + buffer->Protocol[1] = 'S'; + buffer->Protocol[2] = 'M'; + buffer->Protocol[3] = 'B'; + buffer->Command = smb_command; + buffer->Flags = 0x00; /* case sensitive */ + buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES; + buffer->Pid = cpu_to_le16((__u16)current->tgid); + buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16)); + if (treeCon) { + buffer->Tid = treeCon->tid; + if (treeCon->ses) { + if (treeCon->ses->capabilities & CAP_UNICODE) + buffer->Flags2 |= SMBFLG2_UNICODE; + if (treeCon->ses->capabilities & CAP_STATUS32) + buffer->Flags2 |= SMBFLG2_ERR_STATUS; + + /* Uid is not converted */ + buffer->Uid = treeCon->ses->Suid; + buffer->Mid = get_next_mid(treeCon->ses->server); + } + if (treeCon->Flags & SMB_SHARE_IS_IN_DFS) + buffer->Flags2 |= SMBFLG2_DFS; + if (treeCon->nocase) + buffer->Flags |= SMBFLG_CASELESS; + if ((treeCon->ses) && (treeCon->ses->server)) + if (treeCon->ses->server->sign) + buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE; + } + +/* endian conversion of flags is now done just before sending */ + buffer->WordCount = (char) word_count; + return; +} + +static int +check_smb_hdr(struct smb_hdr *smb) +{ + /* does it have the right SMB "signature" ? */ + if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) { + cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n", + *(unsigned int *)smb->Protocol); + return 1; + } + + /* if it's a response then accept */ + if (smb->Flags & SMBFLG_RESPONSE) + return 0; + + /* only one valid case where server sends us request */ + if (smb->Command == SMB_COM_LOCKING_ANDX) + return 0; + + cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", + get_mid(smb)); + return 1; +} + +int +checkSMB(char *buf, unsigned int total_read) +{ + struct smb_hdr *smb = (struct smb_hdr *)buf; + __u32 rfclen = be32_to_cpu(smb->smb_buf_length); + __u32 clc_len; /* calculated length */ + cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n", + total_read, rfclen); + + /* is this frame too small to even get to a BCC? */ + if (total_read < 2 + sizeof(struct smb_hdr)) { + if ((total_read >= sizeof(struct smb_hdr) - 1) + && (smb->Status.CifsError != 0)) { + /* it's an error return */ + smb->WordCount = 0; + /* some error cases do not return wct and bcc */ + return 0; + } else if ((total_read == sizeof(struct smb_hdr) + 1) && + (smb->WordCount == 0)) { + char *tmp = (char *)smb; + /* Need to work around a bug in two servers here */ + /* First, check if the part of bcc they sent was zero */ + if (tmp[sizeof(struct smb_hdr)] == 0) { + /* some servers return only half of bcc + * on simple responses (wct, bcc both zero) + * in particular have seen this on + * ulogoffX and FindClose. This leaves + * one byte of bcc potentially unitialized + */ + /* zero rest of bcc */ + tmp[sizeof(struct smb_hdr)+1] = 0; + return 0; + } + cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n"); + } else { + cifs_dbg(VFS, "Length less than smb header size\n"); + } + return -EIO; + } + + /* otherwise, there is enough to get to the BCC */ + if (check_smb_hdr(smb)) + return -EIO; + clc_len = smbCalcSize(smb); + + if (4 + rfclen != total_read) { + cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n", + rfclen); + return -EIO; + } + + if (4 + rfclen != clc_len) { + __u16 mid = get_mid(smb); + /* check if bcc wrapped around for large read responses */ + if ((rfclen > 64 * 1024) && (rfclen > clc_len)) { + /* check if lengths match mod 64K */ + if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF)) + return 0; /* bcc wrapped */ + } + cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n", + clc_len, 4 + rfclen, mid); + + if (4 + rfclen < clc_len) { + cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n", + rfclen, mid); + return -EIO; + } else if (rfclen > clc_len + 512) { + /* + * Some servers (Windows XP in particular) send more + * data than the lengths in the SMB packet would + * indicate on certain calls (byte range locks and + * trans2 find first calls in particular). While the + * client can handle such a frame by ignoring the + * trailing data, we choose limit the amount of extra + * data to 512 bytes. + */ + cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n", + rfclen, mid); + return -EIO; + } + } + return 0; +} + +bool +is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) +{ + struct smb_hdr *buf = (struct smb_hdr *)buffer; + struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf; + struct list_head *tmp, *tmp1, *tmp2; + struct cifs_ses *ses; + struct cifs_tcon *tcon; + struct cifsInodeInfo *pCifsInode; + struct cifsFileInfo *netfile; + + cifs_dbg(FYI, "Checking for oplock break or dnotify response\n"); + if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) && + (pSMB->hdr.Flags & SMBFLG_RESPONSE)) { + struct smb_com_transaction_change_notify_rsp *pSMBr = + (struct smb_com_transaction_change_notify_rsp *)buf; + struct file_notify_information *pnotify; + __u32 data_offset = 0; + if (get_bcc(buf) > sizeof(struct file_notify_information)) { + data_offset = le32_to_cpu(pSMBr->DataOffset); + + pnotify = (struct file_notify_information *) + ((char *)&pSMBr->hdr.Protocol + data_offset); + cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n", + pnotify->FileName, pnotify->Action); + /* cifs_dump_mem("Rcvd notify Data: ",buf, + sizeof(struct smb_hdr)+60); */ + return true; + } + if (pSMBr->hdr.Status.CifsError) { + cifs_dbg(FYI, "notify err 0x%x\n", + pSMBr->hdr.Status.CifsError); + return true; + } + return false; + } + if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX) + return false; + if (pSMB->hdr.Flags & SMBFLG_RESPONSE) { + /* no sense logging error on invalid handle on oplock + break - harmless race between close request and oplock + break response is expected from time to time writing out + large dirty files cached on the client */ + if ((NT_STATUS_INVALID_HANDLE) == + le32_to_cpu(pSMB->hdr.Status.CifsError)) { + cifs_dbg(FYI, "invalid handle on oplock break\n"); + return true; + } else if (ERRbadfid == + le16_to_cpu(pSMB->hdr.Status.DosError.Error)) { + return true; + } else { + return false; /* on valid oplock brk we get "request" */ + } + } + if (pSMB->hdr.WordCount != 8) + return false; + + cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n", + pSMB->LockType, pSMB->OplockLevel); + if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)) + return false; + + /* look up tcon based on tid & uid */ + spin_lock(&cifs_tcp_ses_lock); + list_for_each(tmp, &srv->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); + if (tcon->tid != buf->Tid) + continue; + + cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks); + spin_lock(&cifs_file_list_lock); + list_for_each(tmp2, &tcon->openFileList) { + netfile = list_entry(tmp2, struct cifsFileInfo, + tlist); + if (pSMB->Fid != netfile->fid.netfid) + continue; + + cifs_dbg(FYI, "file id match, oplock break\n"); + pCifsInode = CIFS_I(d_inode(netfile->dentry)); + + set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, + &pCifsInode->flags); + + /* + * Set flag if the server downgrades the oplock + * to L2 else clear. + */ + if (pSMB->OplockLevel) + set_bit( + CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, + &pCifsInode->flags); + else + clear_bit( + CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, + &pCifsInode->flags); + + queue_work(cifsiod_wq, + &netfile->oplock_break); + netfile->oplock_break_cancelled = false; + + 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 true; +} + +void +dump_smb(void *buf, int smb_buf_length) +{ + if (traceSMB == 0) + return; + + print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf, + smb_buf_length, true); +} + +void +cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb) +{ + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) { + cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM; + cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n", + cifs_sb_master_tcon(cifs_sb)->treeName); + } +} + +void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) +{ + oplock &= 0xF; + + if (oplock == OPLOCK_EXCLUSIVE) { + cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG; + cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n", + &cinode->vfs_inode); + } else if (oplock == OPLOCK_READ) { + cinode->oplock = CIFS_CACHE_READ_FLG; + cifs_dbg(FYI, "Level II Oplock granted on inode %p\n", + &cinode->vfs_inode); + } else + cinode->oplock = 0; +} + +/* + * We wait for oplock breaks to be processed before we attempt to perform + * writes. + */ +int cifs_get_writer(struct cifsInodeInfo *cinode) +{ + int rc; + +start: + rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK, + TASK_KILLABLE); + if (rc) + return rc; + + spin_lock(&cinode->writers_lock); + if (!cinode->writers) + set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); + cinode->writers++; + /* Check to see if we have started servicing an oplock break */ + if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) { + cinode->writers--; + if (cinode->writers == 0) { + clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); + wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); + } + spin_unlock(&cinode->writers_lock); + goto start; + } + spin_unlock(&cinode->writers_lock); + return 0; +} + +void cifs_put_writer(struct cifsInodeInfo *cinode) +{ + spin_lock(&cinode->writers_lock); + cinode->writers--; + if (cinode->writers == 0) { + clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags); + wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS); + } + spin_unlock(&cinode->writers_lock); +} + +void cifs_done_oplock_break(struct cifsInodeInfo *cinode) +{ + clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags); + wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK); +} + +bool +backup_cred(struct cifs_sb_info *cifs_sb) +{ + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) { + if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid())) + return true; + } + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) { + if (in_group_p(cifs_sb->mnt_backupgid)) + return true; + } + + return false; +} + +void +cifs_del_pending_open(struct cifs_pending_open *open) +{ + spin_lock(&cifs_file_list_lock); + list_del(&open->olist); + spin_unlock(&cifs_file_list_lock); +} + +void +cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink, + struct cifs_pending_open *open) +{ +#ifdef CONFIG_CIFS_SMB2 + memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE); +#endif + open->oplock = CIFS_OPLOCK_NO_CHANGE; + open->tlink = tlink; + fid->pending_open = open; + list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens); +} + +void +cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, + struct cifs_pending_open *open) +{ + spin_lock(&cifs_file_list_lock); + cifs_add_pending_open_locked(fid, tlink, open); + spin_unlock(&cifs_file_list_lock); +} |