1 /* $NetBSD: get_names.c,v 1.16 2012/12/29 23:44:23 christos Exp $ */ 2 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 #include <sys/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)get_names.c 8.1 (Berkeley) 6/6/93"; 36 #endif 37 __RCSID("$NetBSD: get_names.c,v 1.16 2012/12/29 23:44:23 christos Exp $"); 38 #endif /* not lint */ 39 40 #include "talk.h" 41 #include <err.h> 42 #include <sys/param.h> 43 #include <pwd.h> 44 #include <stdlib.h> 45 #include <unistd.h> 46 #include <util.h> 47 48 extern CTL_MSG msg; 49 50 /* 51 * Determine the local and remote user, tty, and machines 52 */ 53 void 54 get_names(int argc, char *argv[]) 55 { 56 char hostname[MAXHOSTNAMELEN + 1]; 57 const char *his_name, *my_name; 58 const char *my_machine_name, *his_machine_name; 59 const char *his_tty; 60 char *cp; 61 char *names; 62 63 if (argc < 2 ) { 64 fprintf(stderr, "Usage: %s user [ttyname]\n", getprogname()); 65 exit(1); 66 } 67 if (!isatty(0)) 68 errx(EXIT_FAILURE, "Standard input must be a tty, " 69 "not a pipe or a file"); 70 if ((my_name = getlogin()) == NULL) { 71 struct passwd *pw; 72 73 if ((pw = getpwuid(getuid())) == NULL) 74 errx(EXIT_FAILURE, "You don't exist. Go away."); 75 my_name = pw->pw_name; 76 } 77 if ((cp = getenv("TALKHOST")) != NULL) 78 (void)estrlcpy(hostname, cp, sizeof(hostname)); 79 else { 80 if (gethostname(hostname, sizeof(hostname)) == -1) 81 err(EXIT_FAILURE, "gethostname"); 82 hostname[sizeof(hostname) - 1] = '\0'; 83 } 84 my_machine_name = hostname; 85 /* check for, and strip out, the machine name of the target */ 86 names = strdup(argv[1]); 87 for (cp = names; *cp && !strchr("@:!.", *cp); cp++) 88 ; 89 if (*cp == '\0') { 90 /* this is a local to local talk */ 91 his_name = names; 92 his_machine_name = my_machine_name; 93 } else { 94 if (*cp++ == '@') { 95 /* user@host */ 96 his_name = names; 97 his_machine_name = cp; 98 } else { 99 /* host.user or host!user or host:user */ 100 his_name = cp; 101 his_machine_name = names; 102 } 103 *--cp = '\0'; 104 } 105 if (argc > 2) 106 his_tty = argv[2]; /* tty name is arg 2 */ 107 else 108 his_tty = ""; 109 get_addrs(my_machine_name, his_machine_name); 110 /* 111 * Initialize the message template. 112 */ 113 msg.vers = TALK_VERSION; 114 msg.addr.sa_family = htons(AF_INET); 115 msg.ctl_addr.sa_family = htons(AF_INET); 116 msg.id_num = htonl(0); 117 strncpy(msg.l_name, my_name, NAME_SIZE); 118 msg.l_name[NAME_SIZE - 1] = '\0'; 119 strncpy(msg.r_name, his_name, NAME_SIZE); 120 msg.r_name[NAME_SIZE - 1] = '\0'; 121 strncpy(msg.r_tty, his_tty, TTY_SIZE); 122 msg.r_tty[TTY_SIZE - 1] = '\0'; 123 free(names); 124 } 125