1 /* $NetBSD: wall.c,v 1.18 2001/01/05 04:06:49 mjl Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1990, 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1988, 1990, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93"; 45 #endif 46 __RCSID("$NetBSD: wall.c,v 1.18 2001/01/05 04:06:49 mjl Exp $"); 47 #endif /* not lint */ 48 49 /* 50 * This program is not related to David Wall, whose Stanford Ph.D. thesis 51 * is entitled "Mechanisms for Broadcast and Selective Broadcast". 52 */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 #include <sys/time.h> 57 #include <sys/uio.h> 58 59 #include <err.h> 60 #include <paths.h> 61 #include <pwd.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <unistd.h> 66 #include <utmp.h> 67 #include <util.h> 68 69 void makemsg(const char *); 70 int main(int, char **); 71 72 int nobanner; 73 int mbufsize; 74 char *mbuf; 75 76 /* ARGSUSED */ 77 int 78 main(int argc, char **argv) 79 { 80 int ch; 81 struct iovec iov; 82 struct utmp utmp; 83 FILE *fp; 84 char *p; 85 struct passwd *pep = getpwnam("nobody"); 86 char line[sizeof(utmp.ut_line) + 1]; 87 88 while ((ch = getopt(argc, argv, "n")) != -1) 89 switch (ch) { 90 case 'n': 91 /* undoc option for shutdown: suppress banner */ 92 if (geteuid() == 0 || (pep && getuid() == pep->pw_uid)) 93 nobanner = 1; 94 break; 95 case '?': 96 default: 97 usage: 98 (void)fprintf(stderr, "usage: wall [file]\n"); 99 exit(1); 100 } 101 argc -= optind; 102 argv += optind; 103 if (argc > 1) 104 goto usage; 105 106 makemsg(*argv); 107 108 if (!(fp = fopen(_PATH_UTMP, "r"))) 109 err(1, "cannot read %s", _PATH_UTMP); 110 iov.iov_base = mbuf; 111 iov.iov_len = mbufsize; 112 /* NOSTRICT */ 113 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) { 114 if (!utmp.ut_name[0]) 115 continue; 116 strncpy(line, utmp.ut_line, sizeof(utmp.ut_line)); 117 line[sizeof(utmp.ut_line)] = '\0'; 118 if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL) 119 warnx("%s", p); 120 } 121 exit(0); 122 } 123 124 void 125 makemsg(const char *fname) 126 { 127 register int ch, cnt; 128 struct tm *lt; 129 struct passwd *pw; 130 struct stat sbuf; 131 time_t now; 132 FILE *fp; 133 int fd; 134 const char *whom; 135 char *p, *tty, tmpname[32], lbuf[100], hostname[MAXHOSTNAMELEN+1]; 136 137 (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); 138 if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+"))) 139 err(1, "can't open temporary file"); 140 (void)unlink(tmpname); 141 142 if (!nobanner) { 143 if (!(whom = getlogin())) 144 whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; 145 (void)gethostname(hostname, sizeof(hostname)); 146 hostname[sizeof(hostname) - 1] = '\0'; 147 (void)time(&now); 148 lt = localtime(&now); 149 150 /* 151 * all this stuff is to blank out a square for the message; 152 * we wrap message lines at column 79, not 80, because some 153 * terminals wrap after 79, some do not, and we can't tell. 154 * Which means that we may leave a non-blank character 155 * in column 80, but that can't be helped. 156 */ 157 (void)fprintf(fp, "\r%79s\r\n", " "); 158 (void)snprintf(lbuf, sizeof lbuf, 159 "Broadcast Message from %s@%s", whom, hostname); 160 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); 161 tty = ttyname(STDERR_FILENO); 162 if (tty == NULL) 163 tty = "??"; 164 (void)snprintf(lbuf, sizeof lbuf, 165 " (%s) at %d:%02d ...", tty, lt->tm_hour, 166 lt->tm_min); 167 (void)fprintf(fp, "%-79.79s\r\n", lbuf); 168 } 169 (void)fprintf(fp, "%79s\r\n", " "); 170 171 if (fname && !(freopen(fname, "r", stdin))) 172 err(1, "can't read %s", fname); 173 while (fgets(lbuf, sizeof(lbuf), stdin)) 174 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { 175 if (cnt == 79 || ch == '\n') { 176 for (; cnt < 79; ++cnt) 177 putc(' ', fp); 178 putc('\r', fp); 179 putc('\n', fp); 180 cnt = -1; 181 } 182 if (ch != '\n') 183 putc(ch, fp); 184 } 185 (void)fprintf(fp, "%79s\r\n", " "); 186 rewind(fp); 187 188 if (fstat(fd, &sbuf)) 189 err(1, "can't stat temporary file"); 190 mbufsize = sbuf.st_size; 191 if (!(mbuf = malloc((u_int)mbufsize))) 192 err(1, "malloc"); 193 if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize) 194 err(1, "can't read temporary file"); 195 (void)close(fd); 196 } 197