r6184: the beginnings of the libcli/dgram/ library, and the dgram

server. Currently just listens on port 138 and parses the packets
(using IDL like the rest of NBT). This allows me to develop the
structures and test with real packets
(This used to be commit 10d64a525349ff96695ad961a3cfeb5bc7c8844f)

2 files changed, 194 insertions, 0 deletions

diff --git a/source4/libcli/dgram/dgramsocket.c b/source4/libcli/dgram/dgramsocket.c
new file mode 100644
index 0000000000..7f179bc3c3
--- /dev/null
+++ b/source4/libcli/dgram/dgramsocket.c
@@ -0,0 +1,153 @@
+/* 
+   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;
+}
diff --git a/source4/libcli/dgram/libdgram.h b/source4/libcli/dgram/libdgram.h
new file mode 100644
index 0000000000..6ead6dccf0
--- /dev/null
+++ b/source4/libcli/dgram/libdgram.h
@@ -0,0 +1,41 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   a raw async NBT DGRAM library
+
+   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 "librpc/gen_ndr/ndr_nbt.h"
+
+/*
+  context structure for operations on dgram packets
+*/
+struct nbt_dgram_socket {
+	struct socket_context *sock;
+	struct event_context *event_ctx;
+
+	/* the fd event */
+	struct fd_event *fde;
+
+	/* what to do with incoming request packets */
+	struct {
+		void (*handler)(struct nbt_dgram_socket *, struct nbt_dgram_packet *, 
+				const char *, int );
+		void *private;
+	} incoming;
+};