1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)talkd.h 5.5 (Berkeley) 06/01/90 8 */ 9 10 #include <sys/types.h> 11 #include <sys/socket.h> 12 /* 13 * This describes the protocol used by the talk server and clients. 14 * 15 * The talk server acts a repository of invitations, responding to 16 * requests by clients wishing to rendezvous for the purpose of 17 * holding a conversation. In normal operation, a client, the caller, 18 * initiates a rendezvous by sending a CTL_MSG to the server of 19 * type LOOK_UP. This causes the server to search its invitation 20 * tables to check if an invitation currently exists for the caller 21 * (to speak to the callee specified in the message). If the lookup 22 * fails, the caller then sends an ANNOUNCE message causing the server 23 * to broadcast an announcement on the callee's login ports requesting 24 * contact. When the callee responds, the local server uses the 25 * recorded invitation to respond with the appropriate rendezvous 26 * address and the caller and callee client programs establish a 27 * stream connection through which the conversation takes place. 28 */ 29 30 /* 31 * Client->server request message format. 32 */ 33 typedef struct { 34 u_char vers; /* protocol version */ 35 u_char type; /* request type, see below */ 36 u_char answer; /* not used */ 37 u_char pad; 38 u_long id_num; /* message id */ 39 struct osockaddr addr; /* old (4.3) style */ 40 struct osockaddr ctl_addr; /* old (4.3) style */ 41 long pid; /* caller's process id */ 42 #define NAME_SIZE 12 43 char l_name[NAME_SIZE];/* caller's name */ 44 char r_name[NAME_SIZE];/* callee's name */ 45 #define TTY_SIZE 16 46 char r_tty[TTY_SIZE];/* callee's tty name */ 47 } CTL_MSG; 48 49 /* 50 * Server->client response message format. 51 */ 52 typedef struct { 53 u_char vers; /* protocol version */ 54 u_char type; /* type of request message, see below */ 55 u_char answer; /* respose to request message, see below */ 56 u_char pad; 57 u_long id_num; /* message id */ 58 struct osockaddr addr; /* address for establishing conversation */ 59 } CTL_RESPONSE; 60 61 #define TALK_VERSION 1 /* protocol version */ 62 63 /* message type values */ 64 #define LEAVE_INVITE 0 /* leave invitation with server */ 65 #define LOOK_UP 1 /* check for invitation by callee */ 66 #define DELETE 2 /* delete invitation by caller */ 67 #define ANNOUNCE 3 /* announce invitation by caller */ 68 69 /* answer values */ 70 #define SUCCESS 0 /* operation completed properly */ 71 #define NOT_HERE 1 /* callee not logged in */ 72 #define FAILED 2 /* operation failed for unexplained reason */ 73 #define MACHINE_UNKNOWN 3 /* caller's machine name unknown */ 74 #define PERMISSION_DENIED 4 /* callee's tty doesn't permit announce */ 75 #define UNKNOWN_REQUEST 5 /* request has invalid type value */ 76 #define BADVERSION 6 /* request has invalid protocol version */ 77 #define BADADDR 7 /* request has invalid addr value */ 78 #define BADCTLADDR 8 /* request has invalid ctl_addr value */ 79 80 /* 81 * Operational parameters. 82 */ 83 #define MAX_LIFE 60 /* max time daemon saves invitations */ 84 /* RING_WAIT should be 10's of seconds less than MAX_LIFE */ 85 #define RING_WAIT 30 /* time to wait before resending invitation */ 86