1 .\" This man page is Copyright (C) 1998 Alan Cox.
3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
5 .\" $Id: ddp.7,v 1.3 1999/05/13 11:33:22 freitag Exp $
7 .TH ddp 7 (date) "Linux man-pages (unreleased)"
9 ddp \- Linux AppleTalk protocol implementation
12 .B #include <sys/socket.h>
13 .B #include <netatalk/at.h>
15 .IB ddp_socket " = socket(AF_APPLETALK, SOCK_DGRAM, 0);"
16 .IB raw_socket " = socket(AF_APPLETALK, SOCK_RAW, " protocol ");"
19 Linux implements the AppleTalk protocols described in
20 .IR "Inside AppleTalk" .
21 Only the DDP layer and AARP are present in
23 They are designed to be used via the
27 This page documents the interface for those who wish or need to
28 use the DDP layer directly.
30 The communication between AppleTalk and the user program works using a
31 BSD-compatible socket interface.
32 For more information on sockets, see
35 An AppleTalk socket is created by calling the
39 socket family argument.
40 Valid socket types are
50 is the AppleTalk protocol to be received or sent.
56 Raw sockets may be opened only by a process with effective user ID 0
57 or when the process has the
61 An AppleTalk socket address is defined as a combination of a network number,
62 a node number, and a port number.
71 struct sockaddr_atalk {
72 sa_family_t sat_family; /* address family */
73 unsigned char sat_port; /* port */
74 struct at_addr sat_addr; /* net/node */
84 The port numbers below 129 are known as
85 .IR "reserved ports" .
86 Only processes with the effective user ID 0 or the
87 .B CAP_NET_BIND_SERVICE
97 contains the host network in network byte order.
101 wildcard and also implies \[lq]this network.\[rq]
106 contains the host node number.
110 wildcard and also implies \[lq]this node.\[rq] The value of
113 local broadcast address.
114 .\" FIXME . this doesn't make sense [johnl]
116 No protocol-specific socket options are supported.
120 interfaces to configure some global AppleTalk parameters.
121 The parameters can be accessed by reading or writing files in the directory
122 .IR /proc/sys/net/atalk/ .
124 .I aarp\-expiry\-time
125 The time interval (in seconds) before an AARP cache entry expires.
127 .I aarp\-resolve\-time
128 The time interval (in seconds) before an AARP cache entry is resolved.
130 .I aarp\-retransmit\-limit
131 The number of retransmissions of an AARP query before the node is declared
135 The timer rate (in seconds) for the timer driving AARP.
137 The default values match the specification and should never need to be
140 All ioctls described in
143 .\" FIXME . Add a section about multicasting
147 The user tried to execute an operation without the necessary permissions.
148 These include sending to a broadcast address without
149 having the broadcast flag set,
150 and trying to bind to a reserved port without effective user ID 0 or
151 .BR CAP_NET_BIND_SERVICE .
154 Tried to bind to an address already in use.
157 A nonexistent interface was requested or the requested source address was
161 Operation on a nonblocking socket would block.
164 A connection operation on a nonblocking socket is already in progress.
167 A connection was closed during an
171 No routing table entry matches the destination address.
174 Invalid argument passed.
178 was called on an already connected socket.
181 Datagram is bigger than the DDP MTU.
184 Network device not available or not capable of sending IP.
188 was called on a socket where no packet arrived.
193 Not enough memory available.
196 A kernel subsystem was not configured.
201 Invalid socket option passed.
204 The operation is defined only on a connected socket, but the socket wasn't
208 User doesn't have permission to set high priority,
209 make a configuration change,
210 or send signals to the requested process or group.
213 The connection was unexpectedly closed or shut down by the other end.
216 The socket was unconfigured, or an unknown socket type was requested.
218 AppleTalk is supported by Linux 2.0 or higher.
221 interfaces exist since Linux 2.2.
223 Be very careful with the
225 option; it is not privileged in Linux.
226 It is easy to overload the network
227 with careless sending to broadcast addresses.
229 The basic AppleTalk socket interface is compatible with
231 on BSD-derived systems.
232 Many BSD systems fail to check
234 when sending broadcast frames; this can lead to compatibility problems.
238 socket mode is unique to Linux and exists to support the alternative CAP
239 package and AppleTalk monitoring tools more easily.
241 There are too many inconsistent error values.
243 The ioctls used to configure routing tables, devices,
244 AARP tables, and other devices are not yet described.
248 .BR capabilities (7),