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samba-mirror/source3/smbd/smb2_read.c
Jeremy Allison a8eed184a0 Implement "use sendfile = yes" for SMB2. (cherry picked from commit 95cb7adcd03a1abbd0af395b6c96dd8e0eebd3d1)
Autobuild-User: Jeremy Allison <jra@samba.org>
Autobuild-Date: Wed Dec 15 02:24:08 CET 2010 on sn-devel-104
2010-12-15 02:24:08 +01:00

598 lines
16 KiB
C

/*
Unix SMB/CIFS implementation.
Core SMB2 server
Copyright (C) Stefan Metzmacher 2009
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "smbd/globals.h"
#include "../libcli/smb/smb_common.h"
#include "libcli/security/security.h"
static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct smbd_smb2_request *smb2req,
uint32_t in_smbpid,
uint64_t in_file_id_volatile,
uint32_t in_length,
uint64_t in_offset,
uint32_t in_minimum,
uint32_t in_remaining);
static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
TALLOC_CTX *mem_ctx,
DATA_BLOB *out_data,
uint32_t *out_remaining);
static void smbd_smb2_request_read_done(struct tevent_req *subreq);
NTSTATUS smbd_smb2_request_process_read(struct smbd_smb2_request *req)
{
const uint8_t *inhdr;
const uint8_t *inbody;
int i = req->current_idx;
size_t expected_body_size = 0x31;
size_t body_size;
uint32_t in_smbpid;
uint32_t in_length;
uint64_t in_offset;
uint64_t in_file_id_persistent;
uint64_t in_file_id_volatile;
uint32_t in_minimum_count;
uint32_t in_remaining_bytes;
struct tevent_req *subreq;
inhdr = (const uint8_t *)req->in.vector[i+0].iov_base;
if (req->in.vector[i+1].iov_len != (expected_body_size & 0xFFFFFFFE)) {
return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
}
inbody = (const uint8_t *)req->in.vector[i+1].iov_base;
body_size = SVAL(inbody, 0x00);
if (body_size != expected_body_size) {
return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
}
in_smbpid = IVAL(inhdr, SMB2_HDR_PID);
in_length = IVAL(inbody, 0x04);
in_offset = BVAL(inbody, 0x08);
in_file_id_persistent = BVAL(inbody, 0x10);
in_file_id_volatile = BVAL(inbody, 0x18);
in_minimum_count = IVAL(inbody, 0x20);
in_remaining_bytes = IVAL(inbody, 0x28);
/* check the max read size */
if (in_length > lp_smb2_max_read()) {
DEBUG(0,("here:%s: 0x%08X: 0x%08X\n",
__location__, in_length, lp_smb2_max_read()));
return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
}
if (req->compat_chain_fsp) {
/* skip check */
} else if (in_file_id_persistent != in_file_id_volatile) {
return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
}
subreq = smbd_smb2_read_send(req,
req->sconn->smb2.event_ctx,
req,
in_smbpid,
in_file_id_volatile,
in_length,
in_offset,
in_minimum_count,
in_remaining_bytes);
if (subreq == NULL) {
return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
}
tevent_req_set_callback(subreq, smbd_smb2_request_read_done, req);
return smbd_smb2_request_pending_queue(req, subreq);
}
static void smbd_smb2_request_read_done(struct tevent_req *subreq)
{
struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
struct smbd_smb2_request);
int i = req->current_idx;
uint8_t *outhdr;
DATA_BLOB outbody;
DATA_BLOB outdyn;
uint8_t out_data_offset;
DATA_BLOB out_data_buffer = data_blob_null;
uint32_t out_data_remaining = 0;
NTSTATUS status;
NTSTATUS error; /* transport error */
status = smbd_smb2_read_recv(subreq,
req,
&out_data_buffer,
&out_data_remaining);
TALLOC_FREE(subreq);
if (!NT_STATUS_IS_OK(status)) {
error = smbd_smb2_request_error(req, status);
if (!NT_STATUS_IS_OK(error)) {
smbd_server_connection_terminate(req->sconn,
nt_errstr(error));
return;
}
return;
}
out_data_offset = SMB2_HDR_BODY + 0x10;
outhdr = (uint8_t *)req->out.vector[i].iov_base;
outbody = data_blob_talloc(req->out.vector, NULL, 0x10);
if (outbody.data == NULL) {
error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
if (!NT_STATUS_IS_OK(error)) {
smbd_server_connection_terminate(req->sconn,
nt_errstr(error));
return;
}
return;
}
SSVAL(outbody.data, 0x00, 0x10 + 1); /* struct size */
SCVAL(outbody.data, 0x02,
out_data_offset); /* data offset */
SCVAL(outbody.data, 0x03, 0); /* reserved */
SIVAL(outbody.data, 0x04,
out_data_buffer.length); /* data length */
SIVAL(outbody.data, 0x08,
out_data_remaining); /* data remaining */
SIVAL(outbody.data, 0x0C, 0); /* reserved */
outdyn = out_data_buffer;
error = smbd_smb2_request_done(req, outbody, &outdyn);
if (!NT_STATUS_IS_OK(error)) {
smbd_server_connection_terminate(req->sconn,
nt_errstr(error));
return;
}
}
struct smbd_smb2_read_state {
struct smbd_smb2_request *smb2req;
files_struct *fsp;
uint64_t in_file_id_volatile;
uint32_t in_length;
uint64_t in_offset;
uint32_t in_minimum;
DATA_BLOB out_data;
uint32_t out_remaining;
};
/* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
{
struct lock_struct lock;
uint32_t in_length = state->in_length;
uint64_t in_offset = state->in_offset;
files_struct *fsp = state->fsp;
ssize_t nread;
nread = SMB_VFS_SENDFILE(fsp->conn->sconn->sock,
fsp,
NULL,
in_offset,
in_length);
DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
(int)nread,
fsp_str_dbg(fsp) ));
if (nread == -1) {
if (errno == ENOSYS || errno == EINTR) {
/*
* Special hack for broken systems with no working
* sendfile. Fake this up by doing read/write calls.
*/
set_use_sendfile(SNUM(fsp->conn), false);
nread = fake_sendfile(fsp, in_offset, in_length);
if (nread == -1) {
DEBUG(0,("smb2_sendfile_send_data: "
"fake_sendfile failed for "
"file %s (%s).\n",
fsp_str_dbg(fsp),
strerror(errno)));
exit_server_cleanly("smb2_sendfile_send_data: "
"fake_sendfile failed");
}
goto out;
}
DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
"%s (%s). Terminating\n",
fsp_str_dbg(fsp),
strerror(errno)));
exit_server_cleanly("smb2_sendfile_send_data: sendfile failed");
} else if (nread == 0) {
/*
* Some sendfile implementations return 0 to indicate
* that there was a short read, but nothing was
* actually written to the socket. In this case,
* fallback to the normal read path so the header gets
* the correct byte count.
*/
DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
"falling back to the normal read: %s\n",
fsp_str_dbg(fsp)));
nread = fake_sendfile(fsp, in_offset, in_length);
if (nread == -1) {
DEBUG(0,("smb2_sendfile_send_data: "
"fake_sendfile failed for file "
"%s (%s). Terminating\n",
fsp_str_dbg(fsp),
strerror(errno)));
exit_server_cleanly("smb2_sendfile_send_data: "
"fake_sendfile failed");
}
}
out:
if (nread < in_length) {
sendfile_short_send(fsp, nread, 0, in_length);
}
init_strict_lock_struct(fsp,
state->in_file_id_volatile,
in_offset,
in_length,
READ_LOCK,
&lock);
SMB_VFS_STRICT_UNLOCK(fsp->conn, fsp, &lock);
return 0;
}
static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
struct smbd_smb2_read_state *state)
{
struct smbd_smb2_read_state *state_copy = NULL;
files_struct *fsp = state->fsp;
/*
* We cannot use sendfile if...
* We were not configured to do so OR
* Signing is active OR
* This is a compound SMB2 operation OR
* fsp is a STREAM file OR
* We're using a write cache OR
* It's not a regular file OR
* Requested offset is greater than file size OR
* there's not enough data in the file.
* Phew :-). Luckily this means most
* reads on most normal files. JRA.
*/
if (!_lp_use_sendfile(SNUM(fsp->conn)) ||
smb2req->do_signing ||
smb2req->in.vector_count != 4 ||
(fsp->base_fsp != NULL) ||
(fsp->wcp != NULL) ||
(!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
(state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
(fsp->fsp_name->st.st_ex_size < state->in_offset +
state->in_length)) {
return NT_STATUS_RETRY;
}
/* We've already checked there's this amount of data
to read. */
state->out_data.length = state->in_length;
state->out_remaining = 0;
/* Make a copy of state attached to the smb2req. Attach
the destructor here as this will trigger the sendfile
call when the request is destroyed. */
state_copy = TALLOC_P(smb2req, struct smbd_smb2_read_state);
if (!state_copy) {
return NT_STATUS_NO_MEMORY;
}
*state_copy = *state;
talloc_set_destructor(state_copy, smb2_sendfile_send_data);
return NT_STATUS_OK;
}
static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
/*******************************************************************
Common read complete processing function for both synchronous and
asynchronous reads.
*******************************************************************/
NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
{
struct smbd_smb2_read_state *state = tevent_req_data(req,
struct smbd_smb2_read_state);
files_struct *fsp = state->fsp;
if (nread < 0) {
NTSTATUS status = map_nt_error_from_unix(err);
DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
"Error = %s (NTSTATUS %s)\n",
fsp_str_dbg(fsp),
(int)nread,
strerror(err),
nt_errstr(status)));
return status;
}
if (nread == 0 && state->in_length != 0) {
DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
fsp_str_dbg(fsp)));
return NT_STATUS_END_OF_FILE;
}
if (nread < state->in_minimum) {
DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
"minimum requested %u. Returning end of file\n",
fsp_str_dbg(fsp),
(int)nread,
(unsigned int)state->in_minimum));
return NT_STATUS_END_OF_FILE;
}
DEBUG(3,("smbd_smb2_read: fnum=[%d/%s] length=%lu offset=%lu read=%lu\n",
fsp->fnum,
fsp_str_dbg(fsp),
(unsigned long)state->in_length,
(unsigned long)state->in_offset,
(unsigned long)nread));
state->out_data.length = nread;
state->out_remaining = 0;
return NT_STATUS_OK;
}
static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct smbd_smb2_request *smb2req,
uint32_t in_smbpid,
uint64_t in_file_id_volatile,
uint32_t in_length,
uint64_t in_offset,
uint32_t in_minimum,
uint32_t in_remaining)
{
NTSTATUS status;
struct tevent_req *req = NULL;
struct smbd_smb2_read_state *state = NULL;
struct smb_request *smbreq = NULL;
connection_struct *conn = smb2req->tcon->compat_conn;
files_struct *fsp = NULL;
ssize_t nread = -1;
struct lock_struct lock;
int saved_errno;
req = tevent_req_create(mem_ctx, &state,
struct smbd_smb2_read_state);
if (req == NULL) {
return NULL;
}
state->smb2req = smb2req;
state->in_length = in_length;
state->in_offset = in_offset;
state->in_minimum = in_minimum;
state->out_data = data_blob_null;
state->out_remaining = 0;
DEBUG(10,("smbd_smb2_read: file_id[0x%016llX]\n",
(unsigned long long)in_file_id_volatile));
smbreq = smbd_smb2_fake_smb_request(smb2req);
if (tevent_req_nomem(smbreq, req)) {
return tevent_req_post(req, ev);
}
fsp = file_fsp(smbreq, (uint16_t)in_file_id_volatile);
if (fsp == NULL) {
tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
return tevent_req_post(req, ev);
}
if (conn != fsp->conn) {
tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
return tevent_req_post(req, ev);
}
if (smb2req->session->vuid != fsp->vuid) {
tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
return tevent_req_post(req, ev);
}
if (fsp->is_directory) {
tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
return tevent_req_post(req, ev);
}
state->fsp = fsp;
state->in_file_id_volatile = in_file_id_volatile;
if (IS_IPC(smbreq->conn)) {
struct tevent_req *subreq = NULL;
state->out_data = data_blob_talloc(state, NULL, in_length);
if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
return tevent_req_post(req, ev);
}
if (!fsp_is_np(fsp)) {
tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
return tevent_req_post(req, ev);
}
subreq = np_read_send(state, smbd_event_context(),
fsp->fake_file_handle,
state->out_data.data,
state->out_data.length);
if (tevent_req_nomem(subreq, req)) {
return tevent_req_post(req, ev);
}
tevent_req_set_callback(subreq,
smbd_smb2_read_pipe_done,
req);
return req;
}
if (!CHECK_READ(fsp, smbreq)) {
tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
return tevent_req_post(req, ev);
}
status = schedule_smb2_aio_read(fsp->conn,
smbreq,
fsp,
state,
&state->out_data,
(SMB_OFF_T)in_offset,
(size_t)in_length);
if (NT_STATUS_IS_OK(status)) {
/*
* Doing an async read. Don't
* send a "gone async" message
* as we expect this to be less
* than the client timeout period.
* JRA. FIXME for offline files..
* FIXME. Add cancel code..
*/
smb2req->async = true;
return req;
}
if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
/* Real error in setting up aio. Fail. */
tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
return tevent_req_post(req, ev);
}
/* Fallback to synchronous. */
init_strict_lock_struct(fsp,
in_file_id_volatile,
in_offset,
in_length,
READ_LOCK,
&lock);
if (!SMB_VFS_STRICT_LOCK(conn, fsp, &lock)) {
tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
return tevent_req_post(req, ev);
}
/* Try sendfile in preference. */
status = schedule_smb2_sendfile_read(smb2req, state);
if (NT_STATUS_IS_OK(status)) {
tevent_req_done(req);
return tevent_req_post(req, ev);
} else {
if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
tevent_req_nterror(req, status);
return tevent_req_post(req, ev);
}
}
/* Ok, read into memory. Allocate the out buffer. */
state->out_data = data_blob_talloc(state, NULL, in_length);
if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
return tevent_req_post(req, ev);
}
nread = read_file(fsp,
(char *)state->out_data.data,
in_offset,
in_length);
saved_errno = errno;
SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
DEBUG(10,("smbd_smb2_read: file %s handle [0x%016llX] offset=%llu "
"len=%llu returned %lld\n",
fsp_str_dbg(fsp),
(unsigned long long)in_file_id_volatile,
(unsigned long long)in_offset,
(unsigned long long)in_length,
(long long)nread));
status = smb2_read_complete(req, nread, saved_errno);
if (!NT_STATUS_IS_OK(status)) {
tevent_req_nterror(req, status);
} else {
/* Success. */
tevent_req_done(req);
}
return tevent_req_post(req, ev);
}
static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
{
struct tevent_req *req = tevent_req_callback_data(subreq,
struct tevent_req);
struct smbd_smb2_read_state *state = tevent_req_data(req,
struct smbd_smb2_read_state);
NTSTATUS status;
ssize_t nread = -1;
bool is_data_outstanding;
status = np_read_recv(subreq, &nread, &is_data_outstanding);
TALLOC_FREE(subreq);
if (!NT_STATUS_IS_OK(status)) {
tevent_req_nterror(req, status);
return;
}
if (nread == 0 && state->out_data.length != 0) {
tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
return;
}
state->out_data.length = nread;
state->out_remaining = 0;
tevent_req_done(req);
}
static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
TALLOC_CTX *mem_ctx,
DATA_BLOB *out_data,
uint32_t *out_remaining)
{
NTSTATUS status;
struct smbd_smb2_read_state *state = tevent_req_data(req,
struct smbd_smb2_read_state);
if (tevent_req_is_nterror(req, &status)) {
tevent_req_received(req);
return status;
}
*out_data = state->out_data;
talloc_steal(mem_ctx, out_data->data);
*out_remaining = state->out_remaining;
tevent_req_received(req);
return NT_STATUS_OK;
}