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/*
Unix SMB/CIFS implementation.
low level socket handling for nbt dgram requests (UDP138)
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
#include "lib/events/events.h"
#include "dlinklist.h"
#include "libcli/nbt/libnbt.h"
#include "libcli/dgram/libdgram.h"
#include "lib/socket/socket.h"
#define DGRAM_MAX_PACKET_SIZE 2048
/*
handle recv events on a nbt dgram socket
*/
static void dgm_socket_recv(struct nbt_dgram_socket *nbtsock)
{
TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
NTSTATUS status;
const char *src_addr;
int src_port;
DATA_BLOB blob;
size_t nread;
struct nbt_dgram_packet *packet;
blob = data_blob_talloc(tmp_ctx, NULL, DGRAM_MAX_PACKET_SIZE);
if (blob.data == NULL) {
talloc_free(tmp_ctx);
return;
}
status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread, 0,
&src_addr, &src_port);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return;
}
talloc_steal(tmp_ctx, src_addr);
blob.length = nread;
DEBUG(0,("Received dgram packet of length %d from %s:%d\n",
blob.length, src_addr, src_port));
packet = talloc(tmp_ctx, struct nbt_dgram_packet);
if (packet == NULL) {
talloc_free(tmp_ctx);
return;
}
/* parse the request */
status = ndr_pull_struct_blob(&blob, packet, packet,
(ndr_pull_flags_fn_t)ndr_pull_nbt_dgram_packet);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(2,("Failed to parse incoming NBT DGRAM packet - %s\n",
nt_errstr(status)));
talloc_free(tmp_ctx);
return;
}
NDR_PRINT_DEBUG(nbt_dgram_packet, packet);
talloc_free(tmp_ctx);
}
/*
handle fd events on a nbt_dgram_socket
*/
static void dgm_socket_handler(struct event_context *ev, struct fd_event *fde,
uint16_t flags, void *private)
{
struct nbt_dgram_socket *dgmsock = talloc_get_type(private,
struct nbt_dgram_socket);
if (flags & EVENT_FD_WRITE) {
/* nothing at the moment */
} else if (flags & EVENT_FD_READ) {
dgm_socket_recv(dgmsock);
}
}
/*
initialise a nbt_dgram_socket. The event_ctx is optional, if provided
then operations will use that event context
*/
struct nbt_dgram_socket *nbt_dgram_socket_init(TALLOC_CTX *mem_ctx,
struct event_context *event_ctx)
{
struct nbt_dgram_socket *dgmsock;
NTSTATUS status;
dgmsock = talloc(mem_ctx, struct nbt_dgram_socket);
if (dgmsock == NULL) goto failed;
if (event_ctx == NULL) {
dgmsock->event_ctx = event_context_init(dgmsock);
} else {
dgmsock->event_ctx = talloc_reference(dgmsock, event_ctx);
}
if (dgmsock->event_ctx == NULL) goto failed;
status = socket_create("ip", SOCKET_TYPE_DGRAM, &dgmsock->sock, 0);
if (!NT_STATUS_IS_OK(status)) goto failed;
socket_set_option(dgmsock->sock, "SO_BROADCAST", "1");
talloc_steal(dgmsock, dgmsock->sock);
dgmsock->fde = event_add_fd(dgmsock->event_ctx, dgmsock,
socket_get_fd(dgmsock->sock), 0,
dgm_socket_handler, dgmsock);
return dgmsock;
failed:
talloc_free(dgmsock);
return NULL;
}
/*
setup a handler for incoming requests
*/
NTSTATUS dgram_set_incoming_handler(struct nbt_dgram_socket *dgmsock,
void (*handler)(struct nbt_dgram_socket *,
struct nbt_dgram_packet *,
const char *, int ),
void *private)
{
dgmsock->incoming.handler = handler;
dgmsock->incoming.private = private;
EVENT_FD_READABLE(dgmsock->fde);
return NT_STATUS_OK;
}
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