linux/fs/cifs/misc.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

517 lines
15 KiB
C

/*
* fs/cifs/misc.c
*
* Copyright (C) International Business Machines Corp., 2002,2004
* 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"
extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern struct task_struct * oplockThread;
static __u16 GlobalMid; /* multiplex id - rotating counter */
/* 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
_GetXid(void)
{
unsigned int xid;
spin_lock(&GlobalMid_Lock);
GlobalTotalActiveXid++;
if (GlobalTotalActiveXid > GlobalMaxActiveXid)
GlobalMaxActiveXid = GlobalTotalActiveXid; /* keep high water mark for number of simultaneous vfs ops in our filesystem */
xid = GlobalCurrentXid++;
spin_unlock(&GlobalMid_Lock);
return xid;
}
void
_FreeXid(unsigned int xid)
{
spin_lock(&GlobalMid_Lock);
/* if(GlobalTotalActiveXid == 0)
BUG(); */
GlobalTotalActiveXid--;
spin_unlock(&GlobalMid_Lock);
}
struct cifsSesInfo *
sesInfoAlloc(void)
{
struct cifsSesInfo *ret_buf;
ret_buf =
(struct cifsSesInfo *) kmalloc(sizeof (struct cifsSesInfo),
GFP_KERNEL);
if (ret_buf) {
memset(ret_buf, 0, sizeof (struct cifsSesInfo));
write_lock(&GlobalSMBSeslock);
atomic_inc(&sesInfoAllocCount);
ret_buf->status = CifsNew;
list_add(&ret_buf->cifsSessionList, &GlobalSMBSessionList);
init_MUTEX(&ret_buf->sesSem);
write_unlock(&GlobalSMBSeslock);
}
return ret_buf;
}
void
sesInfoFree(struct cifsSesInfo *buf_to_free)
{
if (buf_to_free == NULL) {
cFYI(1, ("Null buffer passed to sesInfoFree"));
return;
}
write_lock(&GlobalSMBSeslock);
atomic_dec(&sesInfoAllocCount);
list_del(&buf_to_free->cifsSessionList);
write_unlock(&GlobalSMBSeslock);
if (buf_to_free->serverOS)
kfree(buf_to_free->serverOS);
if (buf_to_free->serverDomain)
kfree(buf_to_free->serverDomain);
if (buf_to_free->serverNOS)
kfree(buf_to_free->serverNOS);
if (buf_to_free->password)
kfree(buf_to_free->password);
kfree(buf_to_free);
}
struct cifsTconInfo *
tconInfoAlloc(void)
{
struct cifsTconInfo *ret_buf;
ret_buf =
(struct cifsTconInfo *) kmalloc(sizeof (struct cifsTconInfo),
GFP_KERNEL);
if (ret_buf) {
memset(ret_buf, 0, sizeof (struct cifsTconInfo));
write_lock(&GlobalSMBSeslock);
atomic_inc(&tconInfoAllocCount);
list_add(&ret_buf->cifsConnectionList,
&GlobalTreeConnectionList);
ret_buf->tidStatus = CifsNew;
INIT_LIST_HEAD(&ret_buf->openFileList);
init_MUTEX(&ret_buf->tconSem);
#ifdef CONFIG_CIFS_STATS
spin_lock_init(&ret_buf->stat_lock);
#endif
write_unlock(&GlobalSMBSeslock);
}
return ret_buf;
}
void
tconInfoFree(struct cifsTconInfo *buf_to_free)
{
if (buf_to_free == NULL) {
cFYI(1, ("Null buffer passed to tconInfoFree"));
return;
}
write_lock(&GlobalSMBSeslock);
atomic_dec(&tconInfoAllocCount);
list_del(&buf_to_free->cifsConnectionList);
write_unlock(&GlobalSMBSeslock);
if (buf_to_free->nativeFileSystem)
kfree(buf_to_free->nativeFileSystem);
kfree(buf_to_free);
}
struct smb_hdr *
cifs_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 =
(struct smb_hdr *) mempool_alloc(cifs_req_poolp, SLAB_KERNEL | SLAB_NOFS);
/* clear the first few header bytes */
/* for most paths, more is cleared in header_assemble */
if (ret_buf) {
memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
atomic_inc(&bufAllocCount);
}
return ret_buf;
}
void
cifs_buf_release(void *buf_to_free)
{
if (buf_to_free == NULL) {
/* cFYI(1, ("Null buffer passed to cifs_buf_release"));*/
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 =
(struct smb_hdr *) mempool_alloc(cifs_sm_req_poolp, SLAB_KERNEL | SLAB_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);
}
return ret_buf;
}
void
cifs_small_buf_release(void *buf_to_free)
{
if (buf_to_free == NULL) {
cFYI(1, ("Null buffer passed to cifs_small_buf_release"));
return;
}
mempool_free(buf_to_free,cifs_sm_req_poolp);
atomic_dec(&smBufAllocCount);
return;
}
void
header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
const struct cifsTconInfo *treeCon, int word_count
/* length of fixed section (word count) in two byte units */)
{
struct list_head* temp_item;
struct cifsSesInfo * ses;
char *temp = (char *) buffer;
memset(temp,0,MAX_CIFS_HDR_SIZE);
buffer->smb_buf_length =
(2 * word_count) + sizeof (struct smb_hdr) -
4 /* RFC 1001 length field does not count */ +
2 /* for bcc field itself */ ;
/* Note that this is the only network field that has to be converted to big endian and it is done just before we send it */
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));
spin_lock(&GlobalMid_Lock);
GlobalMid++;
buffer->Mid = GlobalMid;
spin_unlock(&GlobalMid_Lock);
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;
}
buffer->Uid = treeCon->ses->Suid; /* always in LE format */
if(multiuser_mount != 0) {
/* For the multiuser case, there are few obvious technically */
/* possible mechanisms to match the local linux user (uid) */
/* to a valid remote smb user (smb_uid): */
/* 1) Query Winbind (or other local pam/nss daemon */
/* for userid/password/logon_domain or credential */
/* 2) Query Winbind for uid to sid to username mapping */
/* and see if we have a matching password for existing*/
/* session for that user perhas getting password by */
/* adding a new pam_cifs module that stores passwords */
/* so that the cifs vfs can get at that for all logged*/
/* on users */
/* 3) (Which is the mechanism we have chosen) */
/* Search through sessions to the same server for a */
/* a match on the uid that was passed in on mount */
/* with the current processes uid (or euid?) and use */
/* that smb uid. If no existing smb session for */
/* that uid found, use the default smb session ie */
/* the smb session for the volume mounted which is */
/* the same as would be used if the multiuser mount */
/* flag were disabled. */
/* BB Add support for establishing new tCon and SMB Session */
/* with userid/password pairs found on the smb session */
/* for other target tcp/ip addresses BB */
if(current->uid != treeCon->ses->linux_uid) {
cFYI(1,("Multiuser mode and UID did not match tcon uid "));
read_lock(&GlobalSMBSeslock);
list_for_each(temp_item, &GlobalSMBSessionList) {
ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
if(ses->linux_uid == current->uid) {
if(ses->server == treeCon->ses->server) {
cFYI(1,("found matching uid substitute right smb_uid"));
buffer->Uid = ses->Suid;
break;
} else {
/* BB eventually call cifs_setup_session here */
cFYI(1,("local UID found but smb sess with this server does not exist"));
}
}
}
read_unlock(&GlobalSMBSeslock);
}
}
}
if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
buffer->Flags2 |= SMBFLG2_DFS;
if((treeCon->ses) && (treeCon->ses->server))
if(treeCon->ses->server->secMode &
(SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
}
/* endian conversion of flags is now done just before sending */
buffer->WordCount = (char) word_count;
return;
}
int
checkSMBhdr(struct smb_hdr *smb, __u16 mid)
{
/* Make sure that this really is an SMB, that it is a response,
and that the message ids match */
if ((*(__le32 *) smb->Protocol == cpu_to_le32(0x424d53ff)) &&
(mid == smb->Mid)) {
if(smb->Flags & SMBFLG_RESPONSE)
return 0;
else {
/* only one valid case where server sends us request */
if(smb->Command == SMB_COM_LOCKING_ANDX)
return 0;
else
cERROR(1, ("Rcvd Request not response "));
}
} else { /* bad signature or mid */
if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff))
cERROR(1,
("Bad protocol string signature header %x ",
*(unsigned int *) smb->Protocol));
if (mid != smb->Mid)
cERROR(1, ("Mids do not match"));
}
cERROR(1, ("bad smb detected. The Mid=%d", smb->Mid));
return 1;
}
int
checkSMB(struct smb_hdr *smb, __u16 mid, int length)
{
__u32 len = be32_to_cpu(smb->smb_buf_length);
cFYI(0,
("Entering checkSMB with Length: %x, smb_buf_length: %x ",
length, len));
if (((unsigned int)length < 2 + sizeof (struct smb_hdr)) ||
(len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)) {
if ((unsigned int)length < 2 + sizeof (struct smb_hdr)) {
if (((unsigned int)length >=
sizeof (struct smb_hdr) - 1)
&& (smb->Status.CifsError != 0)) {
smb->WordCount = 0;
return 0; /* some error cases do not return wct and bcc */
} else {
cERROR(1, ("Length less than smb header size"));
}
}
if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)
cERROR(1,
("smb_buf_length greater than MaxBufSize"));
cERROR(1,
("bad smb detected. Illegal length. The mid=%d",
smb->Mid));
return 1;
}
if (checkSMBhdr(smb, mid))
return 1;
if ((4 + len != smbCalcSize(smb))
|| (4 + len != (unsigned int)length)) {
return 0;
} else {
cERROR(1, ("smbCalcSize %x ", smbCalcSize(smb)));
cERROR(1,
("bad smb size detected. The Mid=%d", smb->Mid));
return 1;
}
}
int
is_valid_oplock_break(struct smb_hdr *buf)
{
struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)buf;
struct list_head *tmp;
struct list_head *tmp1;
struct cifsTconInfo *tcon;
struct cifsFileInfo *netfile;
cFYI(1,("Checking for oplock break or dnotify response"));
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(pSMBr->ByteCount > sizeof(struct file_notify_information)) {
data_offset = le32_to_cpu(pSMBr->DataOffset);
pnotify = (struct file_notify_information *)((char *)&pSMBr->hdr.Protocol
+ data_offset);
cFYI(1,("dnotify on %s with action: 0x%x",pnotify->FileName,
pnotify->Action)); /* BB removeme BB */
/* cifs_dump_mem("Received notify Data is: ",buf,sizeof(struct smb_hdr)+60); */
return TRUE;
}
if(pSMBr->hdr.Status.CifsError) {
cFYI(1,("notify err 0x%d",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)) {
cFYI(1,("invalid handle on oplock break"));
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;
cFYI(1,(" oplock type 0x%d level 0x%d",pSMB->LockType,pSMB->OplockLevel));
if(!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
return FALSE;
/* look up tcon based on tid & uid */
read_lock(&GlobalSMBSeslock);
list_for_each(tmp, &GlobalTreeConnectionList) {
tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
if (tcon->tid == buf->Tid) {
#ifdef CONFIG_CIFS_STATS
atomic_inc(&tcon->num_oplock_brks);
#endif
list_for_each(tmp1,&tcon->openFileList){
netfile = list_entry(tmp1,struct cifsFileInfo,tlist);
if(pSMB->Fid == netfile->netfid) {
struct cifsInodeInfo *pCifsInode;
read_unlock(&GlobalSMBSeslock);
cFYI(1,("Matching file id, processing oplock break"));
pCifsInode =
CIFS_I(netfile->pInode);
pCifsInode->clientCanCacheAll = FALSE;
if(pSMB->OplockLevel == 0)
pCifsInode->clientCanCacheRead = FALSE;
pCifsInode->oplockPending = TRUE;
AllocOplockQEntry(netfile->pInode, netfile->netfid, tcon);
cFYI(1,("about to wake up oplock thd"));
wake_up_process(oplockThread);
return TRUE;
}
}
read_unlock(&GlobalSMBSeslock);
cFYI(1,("No matching file for oplock break on connection"));
return TRUE;
}
}
read_unlock(&GlobalSMBSeslock);
cFYI(1,("Can not process oplock break for non-existent connection"));
return TRUE;
}
void
dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
{
int i, j;
char debug_line[17];
unsigned char *buffer;
if (traceSMB == 0)
return;
buffer = (unsigned char *) smb_buf;
for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
if (i % 8 == 0) { /* we have reached the beginning of line */
printk(KERN_DEBUG "| ");
j = 0;
}
printk("%0#4x ", buffer[i]);
debug_line[2 * j] = ' ';
if (isprint(buffer[i]))
debug_line[1 + (2 * j)] = buffer[i];
else
debug_line[1 + (2 * j)] = '_';
if (i % 8 == 7) { /* we have reached end of line, time to print ascii */
debug_line[16] = 0;
printk(" | %s\n", debug_line);
}
}
for (; j < 8; j++) {
printk(" ");
debug_line[2 * j] = ' ';
debug_line[1 + (2 * j)] = ' ';
}
printk( " | %s\n", debug_line);
return;
}