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cifs: add server->vals->header_preamble_size
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This variable is set to 4 for all protocol versions and replaces
the hardcoded constant 4 throughought the code.
This will later be updated to reflect whether a response packet
has a 4 byte length preamble or not once we start removing this
field from the SMB2+ dialects.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
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Ronnie Sahlberg authored and Steve French committed Apr 2, 2018
1 parent 21a4e14 commit 93012bf
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Showing 8 changed files with 75 additions and 45 deletions.
1 change: 1 addition & 0 deletions fs/cifs/cifsglob.h
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Original file line number Diff line number Diff line change
Expand Up @@ -468,6 +468,7 @@ struct smb_version_values {
__u32 exclusive_lock_type;
__u32 shared_lock_type;
__u32 unlock_lock_type;
size_t header_preamble_size;
size_t header_size;
size_t max_header_size;
size_t read_rsp_size;
Expand Down
6 changes: 4 additions & 2 deletions fs/cifs/cifssmb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1454,7 +1454,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
unsigned int data_offset, data_len;
struct cifs_readdata *rdata = mid->callback_data;
char *buf = server->smallbuf;
unsigned int buflen = get_rfc1002_length(buf) + 4;
unsigned int buflen = get_rfc1002_length(buf) +
server->vals->header_preamble_size;
bool use_rdma_mr = false;

cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
Expand Down Expand Up @@ -1504,7 +1505,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
return cifs_readv_discard(server, mid);
}

data_offset = server->ops->read_data_offset(buf) + 4;
data_offset = server->ops->read_data_offset(buf) +
server->vals->header_preamble_size;
if (data_offset < server->total_read) {
/*
* win2k8 sometimes sends an offset of 0 when the read
Expand Down
16 changes: 11 additions & 5 deletions fs/cifs/connect.c
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Original file line number Diff line number Diff line change
Expand Up @@ -775,7 +775,8 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
unsigned int pdu_length = get_rfc1002_length(buf);

/* make sure this will fit in a large buffer */
if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) - 4) {
if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
server->vals->header_preamble_size) {
cifs_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
cifs_reconnect(server);
wake_up(&server->response_q);
Expand All @@ -791,7 +792,9 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)

/* now read the rest */
length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
pdu_length - HEADER_SIZE(server) + 1 + 4);
pdu_length - HEADER_SIZE(server) + 1
+ server->vals->header_preamble_size);

if (length < 0)
return length;
server->total_read += length;
Expand Down Expand Up @@ -884,7 +887,8 @@ cifs_demultiplex_thread(void *p)
continue;

/* make sure we have enough to get to the MID */
if (pdu_length < HEADER_SIZE(server) - 1 - 4) {
if (pdu_length < HEADER_SIZE(server) - 1 -
server->vals->header_preamble_size) {
cifs_dbg(VFS, "SMB response too short (%u bytes)\n",
pdu_length);
cifs_reconnect(server);
Expand All @@ -893,8 +897,10 @@ cifs_demultiplex_thread(void *p)
}

/* read down to the MID */
length = cifs_read_from_socket(server, buf + 4,
HEADER_SIZE(server) - 1 - 4);
length = cifs_read_from_socket(server,
buf + server->vals->header_preamble_size,
HEADER_SIZE(server) - 1
- server->vals->header_preamble_size);
if (length < 0)
continue;
server->total_read += length;
Expand Down
1 change: 1 addition & 0 deletions fs/cifs/smb1ops.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1122,6 +1122,7 @@ struct smb_version_values smb1_values = {
.exclusive_lock_type = 0,
.shared_lock_type = LOCKING_ANDX_SHARED_LOCK,
.unlock_lock_type = 0,
.header_preamble_size = 4,
.header_size = sizeof(struct smb_hdr),
.max_header_size = MAX_CIFS_HDR_SIZE,
.read_rsp_size = sizeof(READ_RSP),
Expand Down
19 changes: 10 additions & 9 deletions fs/cifs/smb2misc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -150,7 +150,8 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr)
}
return 1;
}
if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE -
srvr->vals->header_preamble_size) {
cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
mid);
return 1;
Expand Down Expand Up @@ -189,26 +190,26 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr)
}
}

if (4 + len != length) {
if (srvr->vals->header_preamble_size + len != length) {
cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
length, 4 + len, mid);
length, srvr->vals->header_preamble_size + len, mid);
return 1;
}

clc_len = smb2_calc_size(hdr);

if (4 + len != clc_len) {
if (srvr->vals->header_preamble_size + len != clc_len) {
cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
clc_len, 4 + len, mid);
clc_len, srvr->vals->header_preamble_size + len, mid);
/* create failed on symlink */
if (command == SMB2_CREATE_HE &&
shdr->Status == STATUS_STOPPED_ON_SYMLINK)
return 0;
/* Windows 7 server returns 24 bytes more */
if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
if (clc_len + 24 - srvr->vals->header_preamble_size == 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)
if (clc_len == srvr->vals->header_preamble_size + len + 1)
return 0;

/*
Expand All @@ -218,10 +219,10 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr)
* Log the server error (once), but allow it and continue
* since the frame is parseable.
*/
if (clc_len < 4 /* RFC1001 header size */ + len) {
if (clc_len < srvr->vals->header_preamble_size /* RFC1001 header size */ + len) {
printk_once(KERN_WARNING
"SMB2 server sent bad RFC1001 len %d not %d\n",
len, clc_len - 4);
len, clc_len - srvr->vals->header_preamble_size);
return 0;
}

Expand Down
59 changes: 37 additions & 22 deletions fs/cifs/smb2ops.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1457,6 +1457,8 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
unsigned int sub_offset;
unsigned int print_len;
unsigned int print_offset;
struct cifs_ses *ses = tcon->ses;
struct TCP_Server_Info *server = ses->server;

cifs_dbg(FYI, "%s: path: %s\n", __func__, full_path);

Expand All @@ -1479,7 +1481,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
}

if (le32_to_cpu(err_buf->ByteCount) < sizeof(struct smb2_symlink_err_rsp) ||
get_rfc1002_length(err_buf) + 4 < SMB2_SYMLINK_STRUCT_SIZE) {
get_rfc1002_length(err_buf) + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE) {
kfree(utf16_path);
return -ENOENT;
}
Expand All @@ -1492,13 +1494,13 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
print_len = le16_to_cpu(symlink->PrintNameLength);
print_offset = le16_to_cpu(symlink->PrintNameOffset);

if (get_rfc1002_length(err_buf) + 4 <
if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size <
SMB2_SYMLINK_STRUCT_SIZE + sub_offset + sub_len) {
kfree(utf16_path);
return -ENOENT;
}

if (get_rfc1002_length(err_buf) + 4 <
if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size <
SMB2_SYMLINK_STRUCT_SIZE + print_offset + print_len) {
kfree(utf16_path);
return -ENOENT;
Expand Down Expand Up @@ -2050,7 +2052,8 @@ smb2_dir_needs_close(struct cifsFileInfo *cfile)
}

static void
fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq)
fill_transform_hdr(struct TCP_Server_Info *server,
struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq)
{
struct smb2_sync_hdr *shdr =
(struct smb2_sync_hdr *)old_rq->rq_iov[1].iov_base;
Expand All @@ -2062,7 +2065,7 @@ fill_transform_hdr(struct smb2_transform_hdr *tr_hdr, struct smb_rqst *old_rq)
tr_hdr->Flags = cpu_to_le16(0x01);
get_random_bytes(&tr_hdr->Nonce, SMB3_AES128CMM_NONCE);
memcpy(&tr_hdr->SessionId, &shdr->SessionId, 8);
inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - 4);
inc_rfc1001_len(tr_hdr, sizeof(struct smb2_transform_hdr) - server->vals->header_preamble_size);
inc_rfc1001_len(tr_hdr, orig_len);
}

Expand Down Expand Up @@ -2134,7 +2137,7 @@ crypt_message(struct TCP_Server_Info *server, struct smb_rqst *rqst, int enc)
{
struct smb2_transform_hdr *tr_hdr =
(struct smb2_transform_hdr *)rqst->rq_iov[0].iov_base;
unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 24;
unsigned int assoc_data_len = sizeof(struct smb2_transform_hdr) - 20 - server->vals->header_preamble_size;
int rc = 0;
struct scatterlist *sg;
u8 sign[SMB2_SIGNATURE_SIZE] = {};
Expand Down Expand Up @@ -2262,7 +2265,7 @@ smb3_init_transform_rq(struct TCP_Server_Info *server, struct smb_rqst *new_rq,
goto err_free_iov;

/* fill the 1st iov with a transform header */
fill_transform_hdr(tr_hdr, old_rq);
fill_transform_hdr(server, tr_hdr, old_rq);
new_rq->rq_iov[0].iov_base = tr_hdr;
new_rq->rq_iov[0].iov_len = sizeof(struct smb2_transform_hdr);

Expand Down Expand Up @@ -2344,10 +2347,10 @@ decrypt_raw_data(struct TCP_Server_Info *server, char *buf,
if (rc)
return rc;

memmove(buf + 4, iov[1].iov_base, buf_data_size);
memmove(buf + server->vals->header_preamble_size, iov[1].iov_base, buf_data_size);
hdr = (struct smb2_hdr *)buf;
hdr->smb2_buf_length = cpu_to_be32(buf_data_size + page_data_size);
server->total_read = buf_data_size + page_data_size + 4;
server->total_read = buf_data_size + page_data_size + server->vals->header_preamble_size;

return rc;
}
Expand Down Expand Up @@ -2451,7 +2454,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
return 0;
}

data_offset = server->ops->read_data_offset(buf) + 4;
data_offset = server->ops->read_data_offset(buf) + server->vals->header_preamble_size;
#ifdef CONFIG_CIFS_SMB_DIRECT
use_rdma_mr = rdata->mr;
#endif
Expand Down Expand Up @@ -2547,20 +2550,22 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
unsigned int npages;
struct page **pages;
unsigned int len;
unsigned int buflen = get_rfc1002_length(buf) + 4;
unsigned int buflen = get_rfc1002_length(buf) + server->vals->header_preamble_size;
int rc;
int i = 0;

len = min_t(unsigned int, buflen, server->vals->read_rsp_size - 4 +
len = min_t(unsigned int, buflen, server->vals->read_rsp_size -
server->vals->header_preamble_size +
sizeof(struct smb2_transform_hdr)) - HEADER_SIZE(server) + 1;

rc = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1, len);
if (rc < 0)
return rc;
server->total_read += rc;

len = le32_to_cpu(tr_hdr->OriginalMessageSize) + 4 -
server->vals->read_rsp_size;
len = le32_to_cpu(tr_hdr->OriginalMessageSize) +
server->vals->header_preamble_size -
server->vals->read_rsp_size;
npages = DIV_ROUND_UP(len, PAGE_SIZE);

pages = kmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
Expand All @@ -2586,7 +2591,8 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
if (rc)
goto free_pages;

rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size - 4,
rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size -
server->vals->header_preamble_size,
pages, npages, len);
if (rc)
goto free_pages;
Expand Down Expand Up @@ -2623,20 +2629,21 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
struct mid_q_entry *mid_entry;

/* switch to large buffer if too big for a small one */
if (pdu_length + 4 > MAX_CIFS_SMALL_BUFFER_SIZE) {
if (pdu_length + server->vals->header_preamble_size > MAX_CIFS_SMALL_BUFFER_SIZE) {
server->large_buf = true;
memcpy(server->bigbuf, buf, server->total_read);
buf = server->bigbuf;
}

/* now read the rest */
length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
pdu_length - HEADER_SIZE(server) + 1 + 4);
pdu_length - HEADER_SIZE(server) + 1 +
server->vals->header_preamble_size);
if (length < 0)
return length;
server->total_read += length;

buf_size = pdu_length + 4 - sizeof(struct smb2_transform_hdr);
buf_size = pdu_length + server->vals->header_preamble_size - sizeof(struct smb2_transform_hdr);
length = decrypt_raw_data(server, buf, buf_size, NULL, 0, 0);
if (length)
return length;
Expand Down Expand Up @@ -2665,7 +2672,7 @@ smb3_receive_transform(struct TCP_Server_Info *server, struct mid_q_entry **mid)
struct smb2_transform_hdr *tr_hdr = (struct smb2_transform_hdr *)buf;
unsigned int orig_len = le32_to_cpu(tr_hdr->OriginalMessageSize);

if (pdu_length + 4 < sizeof(struct smb2_transform_hdr) +
if (pdu_length + server->vals->header_preamble_size < sizeof(struct smb2_transform_hdr) +
sizeof(struct smb2_sync_hdr)) {
cifs_dbg(VFS, "Transform message is too small (%u)\n",
pdu_length);
Expand All @@ -2674,14 +2681,14 @@ smb3_receive_transform(struct TCP_Server_Info *server, struct mid_q_entry **mid)
return -ECONNABORTED;
}

if (pdu_length + 4 < orig_len + sizeof(struct smb2_transform_hdr)) {
if (pdu_length + server->vals->header_preamble_size < orig_len + sizeof(struct smb2_transform_hdr)) {
cifs_dbg(VFS, "Transform message is broken\n");
cifs_reconnect(server);
wake_up(&server->response_q);
return -ECONNABORTED;
}

if (pdu_length + 4 > CIFSMaxBufSize + MAX_HEADER_SIZE(server))
if (pdu_length + server->vals->header_preamble_size > CIFSMaxBufSize + MAX_HEADER_SIZE(server))
return receive_encrypted_read(server, mid);

return receive_encrypted_standard(server, mid);
Expand All @@ -2692,7 +2699,8 @@ smb3_handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid)
{
char *buf = server->large_buf ? server->bigbuf : server->smallbuf;

return handle_read_data(server, mid, buf, get_rfc1002_length(buf) + 4,
return handle_read_data(server, mid, buf, get_rfc1002_length(buf) +
server->vals->header_preamble_size,
NULL, 0, 0);
}

Expand Down Expand Up @@ -3097,6 +3105,7 @@ struct smb_version_values smb20_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand All @@ -3117,6 +3126,7 @@ struct smb_version_values smb21_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand All @@ -3137,6 +3147,7 @@ struct smb_version_values smb3any_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand All @@ -3157,6 +3168,7 @@ struct smb_version_values smbdefault_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand All @@ -3177,6 +3189,7 @@ struct smb_version_values smb30_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand All @@ -3197,6 +3210,7 @@ struct smb_version_values smb302_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand All @@ -3218,6 +3232,7 @@ struct smb_version_values smb311_values = {
.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
.header_size = sizeof(struct smb2_hdr),
.header_preamble_size = 4,
.max_header_size = MAX_SMB2_HDR_SIZE,
.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
.lock_cmd = SMB2_LOCK,
Expand Down
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