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/*
Unix SMB/CIFS implementation.
smb2 lib
Copyright (C) Volker Lendecke 2011
Copyright (C) Stefan Metzmacher 2011
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 "client.h"
#include "read_smb.h"
#include "smb2cli_base.h"
#include "lib/async_req/async_sock.h"
#include "lib/util/tevent_ntstatus.h"
struct smb2cli_req_state {
struct tevent_context *ev;
struct cli_state *cli;
const uint8_t *fixed;
uint16_t fixed_len;
const uint8_t *dyn;
uint32_t dyn_len;
uint8_t nbt[4];
uint8_t hdr[64];
uint8_t pad[7]; /* padding space for compounding */
/* always an array of 3 talloc elements */
struct iovec *recv_iov;
};
static void smb2cli_req_unset_pending(struct tevent_req *req)
{
struct smb2cli_req_state *state =
tevent_req_data(req,
struct smb2cli_req_state);
struct cli_state *cli = state->cli;
int num_pending = talloc_array_length(cli->conn.pending);
int i;
talloc_set_destructor(req, NULL);
if (num_pending == 1) {
/*
* The pending read_smb tevent_req is a child of
* cli->conn.pending. So if nothing is pending anymore,
* we need to delete the socket read fde.
*/
TALLOC_FREE(cli->conn.pending);
return;
}
for (i=0; i<num_pending; i++) {
if (req == cli->conn.pending[i]) {
break;
}
}
if (i == num_pending) {
/*
* Something's seriously broken. Just returning here is the
* right thing nevertheless, the point of this routine is to
* remove ourselves from cli->conn.pending.
*/
return;
}
/*
* Remove ourselves from the cli->pending array
*/
for (; i < (num_pending - 1); i++) {
cli->conn.pending[i] = cli->conn.pending[i+1];
}
/*
* No NULL check here, we're shrinking by sizeof(void *), and
* talloc_realloc just adjusts the size for this.
*/
cli->conn.pending = talloc_realloc(NULL, cli->conn.pending,
struct tevent_req *,
num_pending - 1);
return;
}
static int smb2cli_req_destructor(struct tevent_req *req)
{
smb2cli_req_unset_pending(req);
return 0;
}
static void smb2cli_inbuf_received(struct tevent_req *subreq);
static bool smb2cli_req_set_pending(struct tevent_req *req)
{
struct smb2cli_req_state *state =
tevent_req_data(req,
struct smb2cli_req_state);
struct cli_state *cli;
struct tevent_req **pending;
int num_pending;
struct tevent_req *subreq;
cli = state->cli;
num_pending = talloc_array_length(cli->conn.pending);
pending = talloc_realloc(cli, cli->conn.pending, struct tevent_req *,
num_pending+1);
if (pending == NULL) {
return false;
}
pending[num_pending] = req;
cli->conn.pending = pending;
talloc_set_destructor(req, smb2cli_req_destructor);
if (num_pending > 0) {
return true;
}
/*
* We're the first ones, add the read_smb request that waits for the
* answer from the server
*/
subreq = read_smb_send(cli->conn.pending, state->ev, cli->conn.fd);
if (subreq == NULL) {
smb2cli_req_unset_pending(req);
return false;
}
tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
return true;
}
static void smb2cli_notify_pending(struct cli_state *cli, NTSTATUS status)
{
if (cli->conn.fd != -1) {
close(cli->conn.fd);
}
cli->conn.fd = -1;
/*
* Cancel all pending requests. We don't do a for-loop walking
* cli->conn.pending because that array changes in
* cli_smb_req_destructor().
*/
while (talloc_array_length(cli->conn.pending) > 0) {
struct tevent_req *req;
struct smb2cli_req_state *state;
req = cli->conn.pending[0];
state = tevent_req_data(req, struct smb2cli_req_state);
smb2cli_req_unset_pending(req);
/*
* we need to defer the callback, because we may notify more
* then one caller.
*/
tevent_req_defer_callback(req, state->ev);
tevent_req_nterror(req, status);
}
}
struct tevent_req *smb2cli_req_create(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct cli_state *cli,
uint16_t cmd,
uint32_t additional_flags,
uint32_t clear_flags,
uint32_t pid,
uint32_t tid,
uint64_t uid,
const uint8_t *fixed,
uint16_t fixed_len,
const uint8_t *dyn,
uint32_t dyn_len)
{
struct tevent_req *req;
struct smb2cli_req_state *state;
uint32_t flags = 0;
req = tevent_req_create(mem_ctx, &state,
struct smb2cli_req_state);
if (req == NULL) {
return NULL;
}
state->ev = ev;
state->cli = cli;
state->recv_iov = talloc_zero_array(state, struct iovec, 3);
if (state->recv_iov == NULL) {
TALLOC_FREE(req);
return NULL;
}
flags |= additional_flags;
flags &= ~clear_flags;
state->fixed = fixed;
state->fixed_len = fixed_len;
state->dyn = dyn;
state->dyn_len = dyn_len;
SIVAL(state->hdr, SMB2_HDR_PROTOCOL_ID, SMB2_MAGIC);
SSVAL(state->hdr, SMB2_HDR_LENGTH, SMB2_HDR_BODY);
SSVAL(state->hdr, SMB2_HDR_EPOCH, 1);
SIVAL(state->hdr, SMB2_HDR_STATUS, NT_STATUS_V(NT_STATUS_OK));
SSVAL(state->hdr, SMB2_HDR_OPCODE, cmd);
SSVAL(state->hdr, SMB2_HDR_CREDIT, 31);
SIVAL(state->hdr, SMB2_HDR_FLAGS, flags);
SIVAL(state->hdr, SMB2_HDR_PID, cli->smb2.pid);
SIVAL(state->hdr, SMB2_HDR_TID, cli->smb2.tid);
SBVAL(state->hdr, SMB2_HDR_SESSION_ID, cli->smb2.uid);
return req;
}
static void smb2cli_writev_done(struct tevent_req *subreq);
NTSTATUS smb2cli_req_compound_submit(struct tevent_req **reqs,
int num_reqs)
{
struct smb2cli_req_state *state;
struct tevent_req *subreq;
struct iovec *iov;
int i, num_iov, nbt_len;
/*
* 1 for the nbt length
* per request: HDR, fixed, dyn, padding
* -1 because the last one does not need padding
*/
iov = talloc_array(reqs[0], struct iovec, 1 + 4*num_reqs - 1);
if (iov == NULL) {
return NT_STATUS_NO_MEMORY;
}
num_iov = 1;
nbt_len = 0;
for (i=0; i<num_reqs; i++) {
size_t reqlen;
bool ret;
uint64_t mid;
state = tevent_req_data(reqs[i], struct smb2cli_req_state);
mid = state->cli->smb2.mid;
state->cli->smb2.mid += 1;
SBVAL(state->hdr, SMB2_HDR_MESSAGE_ID, mid);
iov[num_iov].iov_base = state->hdr;
iov[num_iov].iov_len = sizeof(state->hdr);
num_iov += 1;
iov[num_iov].iov_base = discard_const(state->fixed);
iov[num_iov].iov_len = state->fixed_len;
num_iov += 1;
if (state->dyn != NULL) {
iov[num_iov].iov_base = discard_const(state->dyn);
iov[num_iov].iov_len = state->dyn_len;
num_iov += 1;
}
reqlen = sizeof(state->hdr) + state->fixed_len +
state->dyn_len;
if (i < num_reqs-1) {
if ((reqlen % 8) > 0) {
uint8_t pad = 8 - (reqlen % 8);
iov[num_iov].iov_base = state->pad;
iov[num_iov].iov_len = pad;
num_iov += 1;
reqlen += pad;
}
SIVAL(state->hdr, SMB2_HDR_NEXT_COMMAND, reqlen);
}
nbt_len += reqlen;
ret = smb2cli_req_set_pending(reqs[i]);
if (!ret) {
return NT_STATUS_NO_MEMORY;
}
}
/*
* TODO: Do signing here
*/
state = tevent_req_data(reqs[0], struct smb2cli_req_state);
_smb_setlen_large(state->nbt, nbt_len);
iov[0].iov_base = state->nbt;
iov[0].iov_len = sizeof(state->nbt);
subreq = writev_send(state, state->ev, state->cli->conn.outgoing,
state->cli->conn.fd, false, iov, num_iov);
if (subreq == NULL) {
return NT_STATUS_NO_MEMORY;
}
tevent_req_set_callback(subreq, smb2cli_writev_done, reqs[0]);
return NT_STATUS_OK;
}
struct tevent_req *smb2cli_req_send(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct cli_state *cli,
uint16_t cmd,
uint32_t additional_flags,
uint32_t clear_flags,
uint32_t pid,
uint32_t tid,
uint64_t uid,
const uint8_t *fixed,
uint16_t fixed_len,
const uint8_t *dyn,
uint32_t dyn_len)
{
struct tevent_req *req;
NTSTATUS status;
req = smb2cli_req_create(mem_ctx, ev, cli, cmd,
additional_flags, clear_flags,
pid, tid, uid,
fixed, fixed_len, dyn, dyn_len);
if (req == NULL) {
return NULL;
}
if (!tevent_req_is_in_progress(req)) {
return tevent_req_post(req, ev);
}
status = smb2cli_req_compound_submit(&req, 1);
if (tevent_req_nterror(req, status)) {
return tevent_req_post(req, ev);
}
return req;
}
static void smb2cli_writev_done(struct tevent_req *subreq)
{
struct tevent_req *req =
tevent_req_callback_data(subreq,
struct tevent_req);
struct smb2cli_req_state *state =
tevent_req_data(req,
struct smb2cli_req_state);
ssize_t nwritten;
int err;
nwritten = writev_recv(subreq, &err);
TALLOC_FREE(subreq);
if (nwritten == -1) {
/* here, we need to notify all pending requests */
smb2cli_notify_pending(state->cli, map_nt_error_from_unix(err));
return;
}
}
static NTSTATUS smb2cli_inbuf_parse_compound(uint8_t *buf, TALLOC_CTX *mem_ctx,
struct iovec **piov, int *pnum_iov)
{
struct iovec *iov;
int num_iov;
size_t buflen;
size_t taken;
num_iov = 1;
iov = talloc_array(mem_ctx, struct iovec, num_iov);
if (iov == NULL) {
return NT_STATUS_NO_MEMORY;
}
iov[0].iov_base = buf;
iov[0].iov_len = 4;
buflen = smb_len_large(buf) + 4;
taken = 4;
while (taken < buflen) {
size_t len = buflen - taken;
uint8_t *hdr = buf + taken;
struct iovec *cur;
size_t full_size;
size_t next_command_ofs;
uint16_t body_size;
struct iovec *iov_tmp;
/*
* We need the header plus the body length field
*/
if (len < SMB2_HDR_BODY + 2) {
DEBUG(10, ("%d bytes left, expected at least %d\n",
(int)len, SMB2_HDR_BODY));
goto inval;
}
if (IVAL(hdr, 0) != SMB2_MAGIC) {
DEBUG(10, ("Got non-SMB2 PDU: %x\n",
IVAL(hdr, 0)));
goto inval;
}
if (SVAL(hdr, 4) != SMB2_HDR_BODY) {
DEBUG(10, ("Got HDR len %d, expected %d\n",
SVAL(hdr, 4), SMB2_HDR_BODY));
goto inval;
}
full_size = len;
next_command_ofs = IVAL(hdr, SMB2_HDR_NEXT_COMMAND);
body_size = SVAL(hdr, SMB2_HDR_BODY);
if (next_command_ofs != 0) {
if (next_command_ofs < (SMB2_HDR_BODY + 2)) {
goto inval;
}
if (next_command_ofs > full_size) {
goto inval;
}
full_size = next_command_ofs;
}
if (body_size < 2) {
goto inval;
}
body_size &= 0xfffe;
if (body_size > (full_size - SMB2_HDR_BODY)) {
goto inval;
}
iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
num_iov + 3);
if (iov_tmp == NULL) {
TALLOC_FREE(iov);
return NT_STATUS_NO_MEMORY;
}
iov = iov_tmp;
cur = &iov[num_iov];
num_iov += 3;
cur[0].iov_base = hdr;
cur[0].iov_len = SMB2_HDR_BODY;
cur[1].iov_base = hdr + SMB2_HDR_BODY;
cur[1].iov_len = body_size;
cur[2].iov_base = hdr + SMB2_HDR_BODY + body_size;
cur[2].iov_len = full_size - (SMB2_HDR_BODY + body_size);
taken += full_size;
}
*piov = iov;
*pnum_iov = num_iov;
return NT_STATUS_OK;
inval:
TALLOC_FREE(iov);
return NT_STATUS_INVALID_NETWORK_RESPONSE;
}
static struct tevent_req *cli_smb2_find_pending(struct cli_state *cli,
uint64_t mid)
{
int num_pending = talloc_array_length(cli->conn.pending);
int i;
for (i=0; i<num_pending; i++) {
struct tevent_req *req = cli->conn.pending[i];
struct smb2cli_req_state *state =
tevent_req_data(req,
struct smb2cli_req_state);
if (mid == BVAL(state->hdr, SMB2_HDR_MESSAGE_ID)) {
return req;
}
}
return NULL;
}
static void smb2cli_inbuf_received(struct tevent_req *subreq)
{
struct cli_state *cli =
tevent_req_callback_data(subreq,
struct cli_state);
TALLOC_CTX *frame = talloc_stackframe();
struct tevent_req *req;
struct smb2cli_req_state *state;
struct iovec *iov;
int i, num_iov;
NTSTATUS status;
uint8_t *inbuf;
ssize_t received;
int err;
size_t num_pending;
received = read_smb_recv(subreq, frame, &inbuf, &err);
TALLOC_FREE(subreq);
if (received == -1) {
/*
* We need to close the connection and notify
* all pending requests.
*/
smb2cli_notify_pending(cli, map_nt_error_from_unix(err));
TALLOC_FREE(frame);
return;
}
status = smb2cli_inbuf_parse_compound(inbuf, frame,
&iov, &num_iov);
if (!NT_STATUS_IS_OK(status)) {
/*
* if we cannot parse the incoming pdu,
* the connection becomes unusable.
*
* We need to close the connection and notify
* all pending requests.
*/
smb2cli_notify_pending(cli, status);
TALLOC_FREE(frame);
return;
}
for (i=1; i<num_iov; i+=3) {
uint8_t *inbuf_ref = NULL;
struct iovec *cur = &iov[i];
uint8_t *inhdr = (uint8_t *)cur[0].iov_base;
req = cli_smb2_find_pending(
cli, BVAL(inhdr, SMB2_HDR_MESSAGE_ID));
if (req == NULL) {
/*
* TODO: handle oplock breaks and async responses
*/
/*
* We need to close the connection and notify
* all pending requests.
*/
smb2cli_notify_pending(cli, status);
TALLOC_FREE(frame);
return;
}
smb2cli_req_unset_pending(req);
state = tevent_req_data(req, struct smb2cli_req_state);
/*
* There might be more than one response
* we need to defer the notifications
*/
tevent_req_defer_callback(req, state->ev);
/*
* Note: here we use talloc_reference() in a way
* that does not expose it to the caller.
*/
inbuf_ref = talloc_reference(state->recv_iov, inbuf);
if (tevent_req_nomem(inbuf_ref, req)) {
continue;
}
/* copy the related buffers */
state->recv_iov[0] = cur[0];
state->recv_iov[1] = cur[1];
state->recv_iov[2] = cur[2];
tevent_req_done(req);
}
TALLOC_FREE(frame);
num_pending = talloc_array_length(cli->conn.pending);
if (num_pending == 0) {
/* no more pending requests, so we are done for now */
return;
}
req = cli->conn.pending[0];
state = tevent_req_data(req, struct smb2cli_req_state);
/*
* add the read_smb request that waits for the
* next answer from the server
*/
subreq = read_smb_send(cli->conn.pending, state->ev, cli->conn.fd);
if (subreq == NULL) {
smb2cli_notify_pending(cli, NT_STATUS_NO_MEMORY);
return;
}
tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
}
NTSTATUS smb2cli_req_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
struct iovec **piov, int body_size)
{
struct smb2cli_req_state *state =
tevent_req_data(req,
struct smb2cli_req_state);
NTSTATUS status;
if (tevent_req_is_nterror(req, &status)) {
return status;
}
status = NT_STATUS(IVAL(state->recv_iov[0].iov_base, SMB2_HDR_STATUS));
if (body_size != 0) {
if (body_size != SVAL(state->recv_iov[1].iov_base, 0)) {
return NT_STATUS_INVALID_NETWORK_RESPONSE;
}
}
if (piov != NULL) {
*piov = talloc_move(mem_ctx, &state->recv_iov);
}
return status;
}
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