1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 33 34 #include <sys/param.h> 35 36 #include <err.h> 37 #include <pwd.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 42 #include "talk.h" 43 44 extern CTL_MSG msg; 45 46 static void 47 usage(void) 48 { 49 fprintf(stderr, "usage: talk person [ttyname]\n"); 50 exit(1); 51 } 52 53 /* 54 * Determine the local and remote user, tty, and machines 55 */ 56 void 57 get_names(int argc, char *argv[]) 58 { 59 char hostname[MAXHOSTNAMELEN]; 60 char *his_name, *my_name; 61 const char *my_machine_name, *his_machine_name; 62 const char *his_tty; 63 char *cp; 64 65 if (argc < 2 ) 66 usage(); 67 if (!isatty(0)) 68 errx(1, "standard input must be a tty, not a pipe or a file"); 69 if ((my_name = getlogin()) == NULL) { 70 struct passwd *pw; 71 72 if ((pw = getpwuid(getuid())) == NULL) 73 errx(1, "you don't exist. Go away"); 74 my_name = pw->pw_name; 75 } 76 gethostname(hostname, sizeof (hostname)); 77 my_machine_name = hostname; 78 /* check for, and strip out, the machine name of the target */ 79 cp = argv[1] + strcspn(argv[1], "@:!"); 80 if (*cp == '\0') { 81 /* this is a local to local talk */ 82 his_name = argv[1]; 83 my_machine_name = his_machine_name = "localhost"; 84 } else { 85 if (*cp++ == '@') { 86 /* user@host */ 87 his_name = argv[1]; 88 his_machine_name = cp; 89 } else { 90 /* host!user or host:user */ 91 his_name = cp; 92 his_machine_name = argv[1]; 93 } 94 *--cp = '\0'; 95 } 96 if (argc > 2) 97 his_tty = argv[2]; /* tty name is arg 2 */ 98 else 99 his_tty = ""; 100 get_addrs(my_machine_name, his_machine_name); 101 /* 102 * Initialize the message template. 103 */ 104 msg.vers = TALK_VERSION; 105 msg.addr.sa_family = htons(AF_INET); 106 msg.ctl_addr.sa_family = htons(AF_INET); 107 msg.id_num = htonl(0); 108 strlcpy(msg.l_name, my_name, NAME_SIZE); 109 strlcpy(msg.r_name, his_name, NAME_SIZE); 110 strlcpy(msg.r_tty, his_tty, TTY_SIZE); 111 } 112