2 Unix SMB/CIFS implementation.
4 packet handling for mailslot requests.
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 3 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, see <http://www.gnu.org/licenses/>.
23 This implements "Class 2 mailslots", i.e. the communication mechanism
24 used for all mailslot packets smaller than 425 bytes.
26 "Class 1 mailslots" (which use SMB) are used for messages larger
27 than 426 bytes and are supported on some systems. These are not implemented
28 in Samba4 yet, as there don't appear to be any core services that use
31 425 and 426-byte sized messages are not supported at all.
35 #include "lib/events/events.h"
36 #include "../lib/util/dlinklist.h"
37 #include "libcli/dgram/libdgram.h"
38 #include "lib/socket/socket.h"
39 #include "param/param.h"
42 destroy a mailslot handler
44 static int dgram_mailslot_destructor(struct dgram_mailslot_handler *dgmslot)
46 DLIST_REMOVE(dgmslot->dgmsock->mailslot_handlers, dgmslot);
51 start listening on a mailslot. talloc_free() the handle to stop listening
53 struct dgram_mailslot_handler *dgram_mailslot_listen(struct nbt_dgram_socket *dgmsock,
54 const char *mailslot_name,
55 dgram_mailslot_handler_t handler,
58 struct dgram_mailslot_handler *dgmslot;
60 dgmslot = talloc(dgmsock, struct dgram_mailslot_handler);
61 if (dgmslot == NULL) return NULL;
63 dgmslot->dgmsock = dgmsock;
64 dgmslot->mailslot_name = talloc_strdup(dgmslot, mailslot_name);
65 if (dgmslot->mailslot_name == NULL) {
69 dgmslot->handler = handler;
70 dgmslot->private = private;
72 DLIST_ADD(dgmsock->mailslot_handlers, dgmslot);
73 talloc_set_destructor(dgmslot, dgram_mailslot_destructor);
75 EVENT_FD_READABLE(dgmsock->fde);
81 find the handler for a specific mailslot name
83 struct dgram_mailslot_handler *dgram_mailslot_find(struct nbt_dgram_socket *dgmsock,
84 const char *mailslot_name)
86 struct dgram_mailslot_handler *h;
87 for (h=dgmsock->mailslot_handlers;h;h=h->next) {
88 if (strcasecmp(h->mailslot_name, mailslot_name) == 0) {
96 check that a datagram packet is a valid mailslot request, and return the
97 mailslot name if it is, otherwise return NULL
99 const char *dgram_mailslot_name(struct nbt_dgram_packet *packet)
101 if (packet->msg_type != DGRAM_DIRECT_UNIQUE &&
102 packet->msg_type != DGRAM_DIRECT_GROUP &&
103 packet->msg_type != DGRAM_BCAST) {
106 if (packet->data.msg.dgram_body_type != DGRAM_SMB) return NULL;
107 if (packet->data.msg.body.smb.smb_command != SMB_TRANSACTION) return NULL;
108 return packet->data.msg.body.smb.body.trans.mailslot_name;
113 create a temporary mailslot handler for a reply mailslot, allocating
114 a new mailslot name using the given base name and a random integer extension
116 struct dgram_mailslot_handler *dgram_mailslot_temp(struct nbt_dgram_socket *dgmsock,
117 const char *mailslot_name,
118 dgram_mailslot_handler_t handler,
123 struct dgram_mailslot_handler *dgmslot;
125 /* try a 100 times at most */
126 for (i=0;i<100;i++) {
127 name = talloc_asprintf(dgmsock, "%s%03u",
129 generate_random() % 1000);
130 if (name == NULL) return NULL;
131 if (dgram_mailslot_find(dgmsock, name)) {
135 dgmslot = dgram_mailslot_listen(dgmsock, name, handler, private);
137 if (dgmslot != NULL) {
141 DEBUG(2,("Unable to create temporary mailslot from %s\n", mailslot_name));
147 send a mailslot request
149 NTSTATUS dgram_mailslot_send(struct nbt_dgram_socket *dgmsock,
150 enum dgram_msg_type msg_type,
151 const char *mailslot_name,
152 struct nbt_name *dest_name,
153 struct socket_address *dest,
154 struct nbt_name *src_name,
157 TALLOC_CTX *tmp_ctx = talloc_new(dgmsock);
158 struct nbt_dgram_packet packet;
159 struct dgram_message *msg;
160 struct dgram_smb_packet *smb;
161 struct smb_trans_body *trans;
162 struct socket_address *src;
165 if (dest->port == 0) {
166 return NT_STATUS_INVALID_PARAMETER;
170 packet.msg_type = msg_type;
171 packet.flags = DGRAM_FLAG_FIRST | DGRAM_NODE_NBDD;
172 packet.dgram_id = generate_random() % UINT16_MAX;
173 src = socket_get_my_addr(dgmsock->sock, tmp_ctx);
175 return NT_STATUS_NO_MEMORY;
177 packet.src_addr = src->addr;
178 packet.src_port = src->port;
180 msg = &packet.data.msg;
181 /* this length calculation is very crude - it should be based on gensize
183 msg->length = 138 + strlen(mailslot_name) + request->length;
186 msg->source_name = *src_name;
187 msg->dest_name = *dest_name;
188 msg->dgram_body_type = DGRAM_SMB;
190 smb = &msg->body.smb;
191 smb->smb_command = SMB_TRANSACTION;
193 trans = &smb->body.trans;
194 trans->total_data_count = request->length;
195 trans->timeout = 1000;
196 trans->data_count = request->length;
197 trans->data_offset = 70 + strlen(mailslot_name);
198 trans->opcode = 1; /* write mail slot */
201 trans->mailslot_name = mailslot_name;
202 trans->data = *request;
204 status = nbt_dgram_send(dgmsock, &packet, dest);
206 talloc_free(tmp_ctx);
212 return the mailslot data portion from a mailslot packet
214 DATA_BLOB dgram_mailslot_data(struct nbt_dgram_packet *dgram)
216 struct smb_trans_body *trans = &dgram->data.msg.body.smb.body.trans;
217 DATA_BLOB ret = trans->data;
218 int pad = trans->data_offset - (70 + strlen(trans->mailslot_name));
220 if (pad < 0 || pad > ret.length) {
221 DEBUG(2,("Badly formatted data in mailslot - pad = %d\n", pad));
222 return data_blob(NULL, 0);