linux/fs/cifs/misc.c
Ronnie Sahlberg 340625e618 cifs: replace various strncpy with strscpy and similar
Using strscpy is cleaner, and avoids some problems with
handling maximum length strings.  Linus noticed the
original problem and Aurelien pointed out some additional
problems. Fortunately most of this is SMB1 code (and
in particular the ASCII string handling older, which
is less common).

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2019-08-27 17:25:12 -05:00

1036 lines
27 KiB
C

/*
* 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 <linux/vmalloc.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "smberr.h"
#include "nterr.h"
#include "cifs_unicode.h"
#include "smb2pdu.h"
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);
spin_lock_init(&ret_buf->iface_lock);
}
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);
kzfree(buf_to_free->password);
kfree(buf_to_free->user_name);
kfree(buf_to_free->domainName);
kzfree(buf_to_free->auth_key.response);
kfree(buf_to_free->iface_list);
kzfree(buf_to_free);
}
struct cifs_tcon *
tconInfoAlloc(void)
{
struct cifs_tcon *ret_buf;
ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
if (!ret_buf)
return NULL;
ret_buf->crfid.fid = kzalloc(sizeof(*ret_buf->crfid.fid), GFP_KERNEL);
if (!ret_buf->crfid.fid) {
kfree(ret_buf);
return NULL;
}
atomic_inc(&tconInfoAllocCount);
ret_buf->tidStatus = CifsNew;
++ret_buf->tc_count;
INIT_LIST_HEAD(&ret_buf->openFileList);
INIT_LIST_HEAD(&ret_buf->tcon_list);
spin_lock_init(&ret_buf->open_file_lock);
mutex_init(&ret_buf->crfid.fid_mutex);
spin_lock_init(&ret_buf->stat_lock);
atomic_set(&ret_buf->num_local_opens, 0);
atomic_set(&ret_buf->num_remote_opens, 0);
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);
kzfree(buf_to_free->password);
kfree(buf_to_free->crfid.fid);
#ifdef CONFIG_CIFS_DFS_UPCALL
kfree(buf_to_free->dfs_path);
#endif
kfree(buf_to_free);
}
struct smb_hdr *
cifs_buf_get(void)
{
struct smb_hdr *ret_buf = NULL;
/*
* SMB2 header is bigger than CIFS one - no problems to clean some
* more bytes for CIFS.
*/
size_t buf_size = sizeof(struct smb2_sync_hdr);
/*
* 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 */
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);
/* 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 TCP_Server_Info *server)
{
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, server);
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;
size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
if (get_bcc(buf) > sizeof(struct file_notify_information)) {
data_offset = le32_to_cpu(pSMBr->DataOffset);
if (data_offset >
len - sizeof(struct file_notify_information)) {
cifs_dbg(FYI, "invalid data_offset %u\n",
data_offset);
return true;
}
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(&tcon->open_file_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);
cifs_queue_oplock_break(netfile);
netfile->oplock_break_cancelled = false;
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_tcp_ses_lock);
return true;
}
spin_unlock(&tcon->open_file_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) {
struct cifs_tcon *tcon = NULL;
if (cifs_sb->master_tlink)
tcon = cifs_sb_master_tcon(cifs_sb);
cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
cifs_sb->mnt_cifs_serverino_autodisabled = true;
cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s.\n",
tcon ? tcon->treeName : "new server");
cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS).\n");
cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
}
}
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);
}
/**
* cifs_queue_oplock_break - queue the oplock break handler for cfile
*
* This function is called from the demultiplex thread when it
* receives an oplock break for @cfile.
*
* Assumes the tcon->open_file_lock is held.
* Assumes cfile->file_info_lock is NOT held.
*/
void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
{
/*
* Bump the handle refcount now while we hold the
* open_file_lock to enforce the validity of it for the oplock
* break handler. The matching put is done at the end of the
* handler.
*/
cifsFileInfo_get(cfile);
queue_work(cifsoplockd_wq, &cfile->oplock_break);
}
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(&tlink_tcon(open->tlink)->open_file_lock);
list_del(&open->olist);
spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
}
void
cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
struct cifs_pending_open *open)
{
memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
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(&tlink_tcon(tlink)->open_file_lock);
cifs_add_pending_open_locked(fid, tlink, open);
spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
}
/* parses DFS refferal V3 structure
* caller is responsible for freeing target_nodes
* returns:
* - on success - 0
* - on failure - errno
*/
int
parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
unsigned int *num_of_nodes,
struct dfs_info3_param **target_nodes,
const struct nls_table *nls_codepage, int remap,
const char *searchName, bool is_unicode)
{
int i, rc = 0;
char *data_end;
struct dfs_referral_level_3 *ref;
*num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
if (*num_of_nodes < 1) {
cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
*num_of_nodes);
rc = -EINVAL;
goto parse_DFS_referrals_exit;
}
ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
if (ref->VersionNumber != cpu_to_le16(3)) {
cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
le16_to_cpu(ref->VersionNumber));
rc = -EINVAL;
goto parse_DFS_referrals_exit;
}
/* get the upper boundary of the resp buffer */
data_end = (char *)rsp + rsp_size;
cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
*num_of_nodes, le32_to_cpu(rsp->DFSFlags));
*target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
GFP_KERNEL);
if (*target_nodes == NULL) {
rc = -ENOMEM;
goto parse_DFS_referrals_exit;
}
/* collect necessary data from referrals */
for (i = 0; i < *num_of_nodes; i++) {
char *temp;
int max_len;
struct dfs_info3_param *node = (*target_nodes)+i;
node->flags = le32_to_cpu(rsp->DFSFlags);
if (is_unicode) {
__le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
GFP_KERNEL);
if (tmp == NULL) {
rc = -ENOMEM;
goto parse_DFS_referrals_exit;
}
cifsConvertToUTF16((__le16 *) tmp, searchName,
PATH_MAX, nls_codepage, remap);
node->path_consumed = cifs_utf16_bytes(tmp,
le16_to_cpu(rsp->PathConsumed),
nls_codepage);
kfree(tmp);
} else
node->path_consumed = le16_to_cpu(rsp->PathConsumed);
node->server_type = le16_to_cpu(ref->ServerType);
node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
/* copy DfsPath */
temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
max_len = data_end - temp;
node->path_name = cifs_strndup_from_utf16(temp, max_len,
is_unicode, nls_codepage);
if (!node->path_name) {
rc = -ENOMEM;
goto parse_DFS_referrals_exit;
}
/* copy link target UNC */
temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
max_len = data_end - temp;
node->node_name = cifs_strndup_from_utf16(temp, max_len,
is_unicode, nls_codepage);
if (!node->node_name) {
rc = -ENOMEM;
goto parse_DFS_referrals_exit;
}
node->ttl = le32_to_cpu(ref->TimeToLive);
ref++;
}
parse_DFS_referrals_exit:
if (rc) {
free_dfs_info_array(*target_nodes, *num_of_nodes);
*target_nodes = NULL;
*num_of_nodes = 0;
}
return rc;
}
struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)
{
struct cifs_aio_ctx *ctx;
/*
* Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
* to false so that we know when we have to unreference pages within
* cifs_aio_ctx_release()
*/
ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
if (!ctx)
return NULL;
INIT_LIST_HEAD(&ctx->list);
mutex_init(&ctx->aio_mutex);
init_completion(&ctx->done);
kref_init(&ctx->refcount);
return ctx;
}
void
cifs_aio_ctx_release(struct kref *refcount)
{
struct cifs_aio_ctx *ctx = container_of(refcount,
struct cifs_aio_ctx, refcount);
cifsFileInfo_put(ctx->cfile);
/*
* ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
* which means that iov_iter_get_pages() was a success and thus that
* we have taken reference on pages.
*/
if (ctx->bv) {
unsigned i;
for (i = 0; i < ctx->npages; i++) {
if (ctx->should_dirty)
set_page_dirty(ctx->bv[i].bv_page);
put_page(ctx->bv[i].bv_page);
}
kvfree(ctx->bv);
}
kfree(ctx);
}
#define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
int
setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
{
ssize_t rc;
unsigned int cur_npages;
unsigned int npages = 0;
unsigned int i;
size_t len;
size_t count = iov_iter_count(iter);
unsigned int saved_len;
size_t start;
unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
struct page **pages = NULL;
struct bio_vec *bv = NULL;
if (iov_iter_is_kvec(iter)) {
memcpy(&ctx->iter, iter, sizeof(struct iov_iter));
ctx->len = count;
iov_iter_advance(iter, count);
return 0;
}
if (max_pages * sizeof(struct bio_vec) <= CIFS_AIO_KMALLOC_LIMIT)
bv = kmalloc_array(max_pages, sizeof(struct bio_vec),
GFP_KERNEL);
if (!bv) {
bv = vmalloc(array_size(max_pages, sizeof(struct bio_vec)));
if (!bv)
return -ENOMEM;
}
if (max_pages * sizeof(struct page *) <= CIFS_AIO_KMALLOC_LIMIT)
pages = kmalloc_array(max_pages, sizeof(struct page *),
GFP_KERNEL);
if (!pages) {
pages = vmalloc(array_size(max_pages, sizeof(struct page *)));
if (!pages) {
kvfree(bv);
return -ENOMEM;
}
}
saved_len = count;
while (count && npages < max_pages) {
rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
if (rc < 0) {
cifs_dbg(VFS, "couldn't get user pages (rc=%zd)\n", rc);
break;
}
if (rc > count) {
cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
count);
break;
}
iov_iter_advance(iter, rc);
count -= rc;
rc += start;
cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
if (npages + cur_npages > max_pages) {
cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
npages + cur_npages, max_pages);
break;
}
for (i = 0; i < cur_npages; i++) {
len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
bv[npages + i].bv_page = pages[i];
bv[npages + i].bv_offset = start;
bv[npages + i].bv_len = len - start;
rc -= len;
start = 0;
}
npages += cur_npages;
}
kvfree(pages);
ctx->bv = bv;
ctx->len = saved_len - count;
ctx->npages = npages;
iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
return 0;
}
/**
* cifs_alloc_hash - allocate hash and hash context together
*
* The caller has to make sure @sdesc is initialized to either NULL or
* a valid context. Both can be freed via cifs_free_hash().
*/
int
cifs_alloc_hash(const char *name,
struct crypto_shash **shash, struct sdesc **sdesc)
{
int rc = 0;
size_t size;
if (*sdesc != NULL)
return 0;
*shash = crypto_alloc_shash(name, 0, 0);
if (IS_ERR(*shash)) {
cifs_dbg(VFS, "could not allocate crypto %s\n", name);
rc = PTR_ERR(*shash);
*shash = NULL;
*sdesc = NULL;
return rc;
}
size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
*sdesc = kmalloc(size, GFP_KERNEL);
if (*sdesc == NULL) {
cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
crypto_free_shash(*shash);
*shash = NULL;
return -ENOMEM;
}
(*sdesc)->shash.tfm = *shash;
return 0;
}
/**
* cifs_free_hash - free hash and hash context together
*
* Freeing a NULL hash or context is safe.
*/
void
cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
{
kfree(*sdesc);
*sdesc = NULL;
if (*shash)
crypto_free_shash(*shash);
*shash = NULL;
}
/**
* rqst_page_get_length - obtain the length and offset for a page in smb_rqst
* Input: rqst - a smb_rqst, page - a page index for rqst
* Output: *len - the length for this page, *offset - the offset for this page
*/
void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
unsigned int *len, unsigned int *offset)
{
*len = rqst->rq_pagesz;
*offset = (page == 0) ? rqst->rq_offset : 0;
if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
*len = rqst->rq_tailsz;
else if (page == 0)
*len = rqst->rq_pagesz - rqst->rq_offset;
}
void extract_unc_hostname(const char *unc, const char **h, size_t *len)
{
const char *end;
/* skip initial slashes */
while (*unc && (*unc == '\\' || *unc == '/'))
unc++;
end = unc;
while (*end && !(*end == '\\' || *end == '/'))
end++;
*h = unc;
*len = end - unc;
}
/**
* copy_path_name - copy src path to dst, possibly truncating
*
* returns number of bytes written (including trailing nul)
*/
int copy_path_name(char *dst, const char *src)
{
int name_len;
/*
* PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
* will truncate and strlen(dst) will be PATH_MAX-1
*/
name_len = strscpy(dst, src, PATH_MAX);
if (WARN_ON_ONCE(name_len < 0))
name_len = PATH_MAX-1;
/* we count the trailing nul */
name_len++;
return name_len;
}