2 Unix SMB/CIFS implementation.
4 low level socket handling for nbt dgram requests (UDP138)
6 Copyright (C) Andrew Tridgell 2005
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include "lib/events/events.h"
25 #include "dlinklist.h"
26 #include "libcli/nbt/libnbt.h"
27 #include "libcli/dgram/libdgram.h"
28 #include "lib/socket/socket.h"
30 #define DGRAM_MAX_PACKET_SIZE 2048
34 handle recv events on a nbt dgram socket
36 static void dgm_socket_recv(struct nbt_dgram_socket *dgmsock)
38 TALLOC_CTX *tmp_ctx = talloc_new(dgmsock);
44 struct nbt_dgram_packet *packet;
45 const char *mailslot_name;
47 blob = data_blob_talloc(tmp_ctx, NULL, DGRAM_MAX_PACKET_SIZE);
48 if (blob.data == NULL) {
53 status = socket_recvfrom(dgmsock->sock, blob.data, blob.length, &nread, 0,
54 &src_addr, &src_port);
55 if (!NT_STATUS_IS_OK(status)) {
59 talloc_steal(tmp_ctx, src_addr);
62 DEBUG(0,("Received dgram packet of length %d from %s:%d\n",
63 blob.length, src_addr, src_port));
65 packet = talloc(tmp_ctx, struct nbt_dgram_packet);
71 /* parse the request */
72 status = ndr_pull_struct_blob(&blob, packet, packet,
73 (ndr_pull_flags_fn_t)ndr_pull_nbt_dgram_packet);
74 if (!NT_STATUS_IS_OK(status)) {
75 DEBUG(2,("Failed to parse incoming NBT DGRAM packet - %s\n",
81 /* if this is a mailslot message, then see if we can dispatch it to a handler */
82 mailslot_name = dgram_mailslot_name(packet);
84 struct dgram_mailslot_handler *dgmslot;
85 dgmslot = dgram_mailslot_find(dgmsock, mailslot_name);
87 dgmslot->handler(dgmslot, packet, src_addr, src_port);
89 DEBUG(2,("No mailslot handler for '%s'\n", mailslot_name));
92 /* dispatch if there is a general handler */
93 if (dgmsock->incoming.handler) {
94 dgmsock->incoming.handler(dgmsock, packet, src_addr, src_port);
103 handle send events on a nbt dgram socket
105 static void dgm_socket_send(struct nbt_dgram_socket *dgmsock)
107 struct nbt_dgram_request *req;
110 while ((req = dgmsock->send_queue)) {
113 len = req->encoded.length;
114 status = socket_sendto(dgmsock->sock, &req->encoded, &len, 0,
115 req->dest_addr, req->dest_port);
116 if (NT_STATUS_IS_ERR(status)) {
117 DEBUG(3,("Failed to send datagram of length %u to %s:%d\n",
118 req->encoded.length, req->dest_addr, req->dest_port));
119 DLIST_REMOVE(dgmsock->send_queue, req);
124 if (!NT_STATUS_IS_OK(status)) return;
126 DLIST_REMOVE(dgmsock->send_queue, req);
130 EVENT_FD_NOT_WRITEABLE(dgmsock->fde);
136 handle fd events on a nbt_dgram_socket
138 static void dgm_socket_handler(struct event_context *ev, struct fd_event *fde,
139 uint16_t flags, void *private)
141 struct nbt_dgram_socket *dgmsock = talloc_get_type(private,
142 struct nbt_dgram_socket);
143 if (flags & EVENT_FD_WRITE) {
144 dgm_socket_send(dgmsock);
145 } else if (flags & EVENT_FD_READ) {
146 dgm_socket_recv(dgmsock);
151 initialise a nbt_dgram_socket. The event_ctx is optional, if provided
152 then operations will use that event context
154 struct nbt_dgram_socket *nbt_dgram_socket_init(TALLOC_CTX *mem_ctx,
155 struct event_context *event_ctx)
157 struct nbt_dgram_socket *dgmsock;
160 dgmsock = talloc(mem_ctx, struct nbt_dgram_socket);
161 if (dgmsock == NULL) goto failed;
163 if (event_ctx == NULL) {
164 dgmsock->event_ctx = event_context_init(dgmsock);
166 dgmsock->event_ctx = talloc_reference(dgmsock, event_ctx);
168 if (dgmsock->event_ctx == NULL) goto failed;
170 status = socket_create("ip", SOCKET_TYPE_DGRAM, &dgmsock->sock, 0);
171 if (!NT_STATUS_IS_OK(status)) goto failed;
173 socket_set_option(dgmsock->sock, "SO_BROADCAST", "1");
175 talloc_steal(dgmsock, dgmsock->sock);
177 dgmsock->fde = event_add_fd(dgmsock->event_ctx, dgmsock,
178 socket_get_fd(dgmsock->sock), 0,
179 dgm_socket_handler, dgmsock);
181 dgmsock->send_queue = NULL;
182 dgmsock->incoming.handler = NULL;
183 dgmsock->mailslot_handlers = NULL;
188 talloc_free(dgmsock);
194 setup a handler for generic incoming requests
196 NTSTATUS dgram_set_incoming_handler(struct nbt_dgram_socket *dgmsock,
197 void (*handler)(struct nbt_dgram_socket *,
198 struct nbt_dgram_packet *,
202 dgmsock->incoming.handler = handler;
203 dgmsock->incoming.private = private;
204 EVENT_FD_READABLE(dgmsock->fde);
210 queue a datagram for send
212 NTSTATUS nbt_dgram_send(struct nbt_dgram_socket *dgmsock,
213 struct nbt_dgram_packet *packet,
214 const char *dest_addr,
217 struct nbt_dgram_request *req;
218 NTSTATUS status = NT_STATUS_NO_MEMORY;
220 req = talloc(dgmsock, struct nbt_dgram_request);
221 if (req == NULL) goto failed;
223 req->dest_addr = talloc_strdup(req, dest_addr);
224 if (req->dest_addr == NULL) goto failed;
225 req->dest_port = dest_port;
227 status = ndr_push_struct_blob(&req->encoded, req, packet,
228 (ndr_push_flags_fn_t)ndr_push_nbt_dgram_packet);
229 if (!NT_STATUS_IS_OK(status)) goto failed;
231 DLIST_ADD_END(dgmsock->send_queue, req, struct nbt_dgram_request *);
233 EVENT_FD_WRITEABLE(dgmsock->fde);