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samba-mirror/libcli/nbt/nbtsocket.c
2012-05-14 15:12:33 +02:00

554 lines
14 KiB
C

/*
Unix SMB/CIFS implementation.
low level socket handling for nbt requests
Copyright (C) Andrew Tridgell 2005
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 "lib/events/events.h"
#include "../lib/util/dlinklist.h"
#include "../libcli/nbt/libnbt.h"
#include "../libcli/nbt/nbt_proto.h"
#include "lib/socket/socket.h"
#include "librpc/gen_ndr/ndr_nbt.h"
#include "param/param.h"
#define NBT_MAX_REPLIES 1000
/*
destroy a pending request
*/
static int nbt_name_request_destructor(struct nbt_name_request *req)
{
if (req->state == NBT_REQUEST_SEND) {
DLIST_REMOVE(req->nbtsock->send_queue, req);
}
if (req->state == NBT_REQUEST_WAIT) {
req->nbtsock->num_pending--;
}
if (req->name_trn_id != 0 && !req->is_reply) {
idr_remove(req->nbtsock->idr, req->name_trn_id);
req->name_trn_id = 0;
}
if (req->te) {
talloc_free(req->te);
req->te = NULL;
}
if (req->nbtsock->send_queue == NULL) {
TEVENT_FD_NOT_WRITEABLE(req->nbtsock->fde);
}
if (req->nbtsock->num_pending == 0 &&
req->nbtsock->incoming.handler == NULL) {
TEVENT_FD_NOT_READABLE(req->nbtsock->fde);
}
return 0;
}
/*
handle send events on a nbt name socket
*/
static void nbt_name_socket_send(struct nbt_name_socket *nbtsock)
{
struct nbt_name_request *req = nbtsock->send_queue;
TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
NTSTATUS status;
while ((req = nbtsock->send_queue)) {
size_t len;
len = req->encoded.length;
status = socket_sendto(nbtsock->sock, &req->encoded, &len,
req->dest);
if (NT_STATUS_IS_ERR(status)) goto failed;
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return;
}
DLIST_REMOVE(nbtsock->send_queue, req);
req->state = NBT_REQUEST_WAIT;
if (req->is_reply) {
talloc_free(req);
} else {
TEVENT_FD_READABLE(nbtsock->fde);
nbtsock->num_pending++;
}
}
TEVENT_FD_NOT_WRITEABLE(nbtsock->fde);
talloc_free(tmp_ctx);
return;
failed:
DLIST_REMOVE(nbtsock->send_queue, req);
nbt_name_request_destructor(req);
req->status = status;
req->state = NBT_REQUEST_ERROR;
talloc_free(tmp_ctx);
if (req->async.fn) {
req->async.fn(req);
} else if (req->is_reply) {
talloc_free(req);
}
return;
}
/*
handle a request timeout
*/
static void nbt_name_socket_timeout(struct tevent_context *ev, struct tevent_timer *te,
struct timeval t, void *private_data)
{
struct nbt_name_request *req = talloc_get_type(private_data,
struct nbt_name_request);
if (req->num_retries != 0) {
req->num_retries--;
req->te = tevent_add_timer(req->nbtsock->event_ctx, req,
timeval_add(&t, req->timeout, 0),
nbt_name_socket_timeout, req);
if (req->state != NBT_REQUEST_SEND) {
req->state = NBT_REQUEST_SEND;
DLIST_ADD_END(req->nbtsock->send_queue, req,
struct nbt_name_request *);
}
TEVENT_FD_WRITEABLE(req->nbtsock->fde);
return;
}
nbt_name_request_destructor(req);
if (req->num_replies == 0) {
req->state = NBT_REQUEST_TIMEOUT;
req->status = NT_STATUS_IO_TIMEOUT;
} else {
req->state = NBT_REQUEST_DONE;
req->status = NT_STATUS_OK;
}
if (req->async.fn) {
req->async.fn(req);
} else if (req->is_reply) {
talloc_free(req);
}
}
/**
handle recv events on a nbt name socket
*/
static void nbt_name_socket_recv(struct nbt_name_socket *nbtsock)
{
TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
NTSTATUS status;
enum ndr_err_code ndr_err;
struct socket_address *src;
DATA_BLOB blob;
size_t nread, dsize;
struct nbt_name_packet *packet;
struct nbt_name_request *req;
status = socket_pending(nbtsock->sock, &dsize);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return;
}
blob = data_blob_talloc(tmp_ctx, NULL, dsize);
if (blob.data == NULL) {
talloc_free(tmp_ctx);
return;
}
status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread,
tmp_ctx, &src);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return;
}
packet = talloc(tmp_ctx, struct nbt_name_packet);
if (packet == NULL) {
talloc_free(tmp_ctx);
return;
}
/* parse the request */
ndr_err = ndr_pull_struct_blob(&blob, packet, packet,
(ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
status = ndr_map_error2ntstatus(ndr_err);
DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
nt_errstr(status)));
talloc_free(tmp_ctx);
return;
}
if (DEBUGLVL(10)) {
DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
(int)blob.length, src->addr, src->port));
NDR_PRINT_DEBUG(nbt_name_packet, packet);
}
/* if its not a reply then pass it off to the incoming request
handler, if any */
if (!(packet->operation & NBT_FLAG_REPLY)) {
if (nbtsock->incoming.handler) {
nbtsock->incoming.handler(nbtsock, packet, src);
}
talloc_free(tmp_ctx);
return;
}
/* find the matching request */
req = (struct nbt_name_request *)idr_find(nbtsock->idr,
packet->name_trn_id);
if (req == NULL) {
if (nbtsock->unexpected.handler) {
nbtsock->unexpected.handler(nbtsock, packet, src);
} else {
DEBUG(10,("Failed to match request for incoming name packet id 0x%04x on %p\n",
packet->name_trn_id, nbtsock));
}
talloc_free(tmp_ctx);
return;
}
talloc_steal(req, packet);
talloc_steal(req, src);
talloc_free(tmp_ctx);
nbt_name_socket_handle_response_packet(req, packet, src);
}
void nbt_name_socket_handle_response_packet(struct nbt_name_request *req,
struct nbt_name_packet *packet,
struct socket_address *src)
{
/* if this is a WACK response, this we need to go back to waiting,
but perhaps increase the timeout */
if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
uint32_t ttl;
if (req->received_wack || packet->ancount < 1) {
nbt_name_request_destructor(req);
req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
req->state = NBT_REQUEST_ERROR;
goto done;
}
talloc_free(req->te);
/* we know we won't need any more retries - the server
has received our request */
req->num_retries = 0;
req->received_wack = true;
/*
* there is a timeout in the packet,
* it is 5 + 4 * num_old_addresses
*
* although w2k3 screws it up
* and uses num_old_addresses = 0
*
* so we better fallback to the maximum
* of num_old_addresses = 25 if we got
* a timeout of less than 9s (5 + 4*1)
* or more than 105s (5 + 4*25).
*/
ttl = packet->answers[0].ttl;
if ((ttl < (5 + 4*1)) || (ttl > (5 + 4*25))) {
ttl = 5 + 4*25;
}
req->timeout = ttl;
req->te = tevent_add_timer(req->nbtsock->event_ctx, req,
timeval_current_ofs(req->timeout, 0),
nbt_name_socket_timeout, req);
return;
}
req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
if (req->replies == NULL) {
nbt_name_request_destructor(req);
req->state = NBT_REQUEST_ERROR;
req->status = NT_STATUS_NO_MEMORY;
goto done;
}
talloc_steal(req, src);
req->replies[req->num_replies].dest = src;
talloc_steal(req, packet);
req->replies[req->num_replies].packet = packet;
req->num_replies++;
/* if we don't want multiple replies then we are done */
if (req->allow_multiple_replies &&
req->num_replies < NBT_MAX_REPLIES) {
return;
}
nbt_name_request_destructor(req);
req->state = NBT_REQUEST_DONE;
req->status = NT_STATUS_OK;
done:
if (req->async.fn) {
req->async.fn(req);
}
}
/*
handle fd events on a nbt_name_socket
*/
static void nbt_name_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
uint16_t flags, void *private_data)
{
struct nbt_name_socket *nbtsock = talloc_get_type(private_data,
struct nbt_name_socket);
if (flags & TEVENT_FD_WRITE) {
nbt_name_socket_send(nbtsock);
}
if (flags & TEVENT_FD_READ) {
nbt_name_socket_recv(nbtsock);
}
}
/*
initialise a nbt_name_socket. The event_ctx is optional, if provided
then operations will use that event context
*/
_PUBLIC_ struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
struct tevent_context *event_ctx)
{
struct nbt_name_socket *nbtsock;
NTSTATUS status;
nbtsock = talloc(mem_ctx, struct nbt_name_socket);
if (nbtsock == NULL) goto failed;
nbtsock->event_ctx = event_ctx;
if (nbtsock->event_ctx == NULL) goto failed;
status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
if (!NT_STATUS_IS_OK(status)) goto failed;
socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
talloc_steal(nbtsock, nbtsock->sock);
nbtsock->idr = idr_init(nbtsock);
if (nbtsock->idr == NULL) goto failed;
nbtsock->send_queue = NULL;
nbtsock->num_pending = 0;
nbtsock->incoming.handler = NULL;
nbtsock->unexpected.handler = NULL;
nbtsock->fde = tevent_add_fd(nbtsock->event_ctx, nbtsock,
socket_get_fd(nbtsock->sock), 0,
nbt_name_socket_handler, nbtsock);
return nbtsock;
failed:
talloc_free(nbtsock);
return NULL;
}
/*
send off a nbt name request
*/
struct nbt_name_request *nbt_name_request_send(struct nbt_name_socket *nbtsock,
struct socket_address *dest,
struct nbt_name_packet *request,
int timeout, int retries,
bool allow_multiple_replies)
{
struct nbt_name_request *req;
int id;
enum ndr_err_code ndr_err;
req = talloc_zero(nbtsock, struct nbt_name_request);
if (req == NULL) goto failed;
req->nbtsock = nbtsock;
req->allow_multiple_replies = allow_multiple_replies;
req->state = NBT_REQUEST_SEND;
req->is_reply = false;
req->timeout = timeout;
req->num_retries = retries;
req->dest = dest;
if (talloc_reference(req, dest) == NULL) goto failed;
/* we select a random transaction id unless the user supplied one */
if (request->name_trn_id == 0) {
id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
} else {
if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
UINT16_MAX);
}
if (id == -1) goto failed;
request->name_trn_id = id;
req->name_trn_id = id;
req->te = tevent_add_timer(nbtsock->event_ctx, req,
timeval_current_ofs(req->timeout, 0),
nbt_name_socket_timeout, req);
talloc_set_destructor(req, nbt_name_request_destructor);
ndr_err = ndr_push_struct_blob(&req->encoded, req,
request,
(ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;
DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
if (DEBUGLVL(10)) {
DEBUG(10,("Queueing nbt packet to %s:%d\n",
req->dest->addr, req->dest->port));
NDR_PRINT_DEBUG(nbt_name_packet, request);
}
TEVENT_FD_WRITEABLE(nbtsock->fde);
return req;
failed:
talloc_free(req);
return NULL;
}
/*
send off a nbt name reply
*/
_PUBLIC_ NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
struct socket_address *dest,
struct nbt_name_packet *request)
{
struct nbt_name_request *req;
enum ndr_err_code ndr_err;
req = talloc_zero(nbtsock, struct nbt_name_request);
NT_STATUS_HAVE_NO_MEMORY(req);
req->nbtsock = nbtsock;
req->dest = dest;
if (talloc_reference(req, dest) == NULL) goto failed;
req->state = NBT_REQUEST_SEND;
req->is_reply = true;
talloc_set_destructor(req, nbt_name_request_destructor);
if (DEBUGLVL(10)) {
NDR_PRINT_DEBUG(nbt_name_packet, request);
}
ndr_err = ndr_push_struct_blob(&req->encoded, req,
request,
(ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
talloc_free(req);
return ndr_map_error2ntstatus(ndr_err);
}
DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
TEVENT_FD_WRITEABLE(nbtsock->fde);
return NT_STATUS_OK;
failed:
talloc_free(req);
return NT_STATUS_NO_MEMORY;
}
/*
wait for a nbt request to complete
*/
NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
{
if (!req) return NT_STATUS_NO_MEMORY;
while (req->state < NBT_REQUEST_DONE) {
if (tevent_loop_once(req->nbtsock->event_ctx) != 0) {
req->state = NBT_REQUEST_ERROR;
req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
break;
}
}
return req->status;
}
/*
setup a handler for incoming requests
*/
_PUBLIC_ NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
struct socket_address *),
void *private_data)
{
nbtsock->incoming.handler = handler;
nbtsock->incoming.private_data = private_data;
TEVENT_FD_READABLE(nbtsock->fde);
return NT_STATUS_OK;
}
/*
setup a handler for unexpected requests
*/
NTSTATUS nbt_set_unexpected_handler(struct nbt_name_socket *nbtsock,
void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
struct socket_address *),
void *private_data)
{
nbtsock->unexpected.handler = handler;
nbtsock->unexpected.private_data = private_data;
TEVENT_FD_READABLE(nbtsock->fde);
return NT_STATUS_OK;
}
/*
turn a NBT rcode into a NTSTATUS
*/
_PUBLIC_ NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
{
int i;
struct {
enum nbt_rcode rcode;
NTSTATUS status;
} map[] = {
{ NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
{ NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
{ NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
{ NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
{ NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
{ NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
{ NBT_RCODE_CFT, NT_STATUS_CONFLICTING_ADDRESSES }
};
for (i=0;i<ARRAY_SIZE(map);i++) {
if (map[i].rcode == rcode) {
return map[i].status;
}
}
return NT_STATUS_UNSUCCESSFUL;
}