usr.bin/wall/wall.c

   1 /*
   2  * Copyright (c) 1988, 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31
  32 __FBSDID("$FreeBSD$");
  33
  34 #ifndef lint
  35 static const char copyright[] =
  36 "@(#) Copyright (c) 1988, 1990, 1993\n\
  37         The Regents of the University of California.  All rights reserved.\n";
  38 #endif
  39
  40 #ifndef lint
  41 static const char sccsid[] = "@(#)wall.c        8.2 (Berkeley) 11/16/93";
  42 #endif
  43
  44 /*
  45  * This program is not related to David Wall, whose Stanford Ph.D. thesis
  46  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
  47  */
  48
  49 #include <sys/param.h>
  50 #include <sys/stat.h>
  51 #include <sys/uio.h>
  52
  53 #include <ctype.h>
  54 #include <err.h>
  55 #include <grp.h>
  56 #include <locale.h>
  57 #include <paths.h>
  58 #include <pwd.h>
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62 #include <time.h>
  63 #include <unistd.h>
  64 #include <utmpx.h>
  65
  66 #include "ttymsg.h"
  67
  68 static void makemsg(char *);
  69 static void usage(void);
  70
  71 struct wallgroup {
  72         struct wallgroup *next;
  73         char            *name;
  74         gid_t           gid;
  75 } *grouplist;
  76 int nobanner;
  77 int mbufsize;
  78 char *mbuf;
  79
  80 static int
  81 ttystat(char *line)
  82 {
  83         struct stat sb;
  84         char ttybuf[MAXPATHLEN];
  85
  86         (void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
  87         if (stat(ttybuf, &sb) == 0) {
  88                 return (0);
  89         } else
  90                 return (-1);
  91 }
  92
  93 int
  94 main(int argc, char *argv[])
  95 {
  96         struct iovec iov;
  97         struct utmpx *utmp;
  98         int ch;
  99         int ingroup;
 100         struct wallgroup *g;
 101         struct group *grp;
 102         char **np;
 103         const char *p;
 104         struct passwd *pw;
 105
 106         (void)setlocale(LC_CTYPE, "");
 107
 108         while ((ch = getopt(argc, argv, "g:n")) != -1)
 109                 switch (ch) {
 110                 case 'n':
 111                         /* undoc option for shutdown: suppress banner */
 112                         if (geteuid() == 0)
 113                                 nobanner = 1;
 114                         break;
 115                 case 'g':
 116                         g = (struct wallgroup *)malloc(sizeof *g);
 117                         g->next = grouplist;
 118                         g->name = optarg;
 119                         g->gid = -1;
 120                         grouplist = g;
 121                         break;
 122                 case '?':
 123                 default:
 124                         usage();
 125                 }
 126         argc -= optind;
 127         argv += optind;
 128         if (argc > 1)
 129                 usage();
 130
 131         for (g = grouplist; g; g = g->next) {
 132                 grp = getgrnam(g->name);
 133                 if (grp != NULL)
 134                         g->gid = grp->gr_gid;
 135                 else
 136                         warnx("%s: no such group", g->name);
 137         }
 138
 139         makemsg(*argv);
 140
 141         iov.iov_base = mbuf;
 142         iov.iov_len = mbufsize;
 143         /* NOSTRICT */
 144         while ((utmp = getutxent()) != NULL) {
 145                 if (utmp->ut_type != USER_PROCESS)
 146                         continue;
 147                 if (ttystat(utmp->ut_line) != 0)
 148                         continue;
 149                 if (grouplist) {
 150                         ingroup = 0;
 151                         pw = getpwnam(utmp->ut_user);
 152                         if (!pw)
 153                                 continue;
 154                         for (g = grouplist; g && ingroup == 0; g = g->next) {
 155                                 if (g->gid == (gid_t)-1)
 156                                         continue;
 157                                 if (g->gid == pw->pw_gid)
 158                                         ingroup = 1;
 159                                 else if ((grp = getgrgid(g->gid)) != NULL) {
 160                                         for (np = grp->gr_mem; *np; np++) {
 161                                                 if (strcmp(*np, utmp->ut_user) == 0) {
 162                                                         ingroup = 1;
 163                                                         break;
 164                                                 }
 165                                         }
 166                                 }
 167                         }
 168                         if (ingroup == 0)
 169                                 continue;
 170                 }
 171                 if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
 172                         warnx("%s", p);
 173         }
 174         exit(0);
 175 }
 176
 177 static void
 178 usage(void)
 179 {
 180         (void)fprintf(stderr, "usage: wall [-g group] [file]\n");
 181         exit(1);
 182 }
 183
 184 void
 185 makemsg(char *fname)
 186 {
 187         int cnt;
 188         unsigned char ch;
 189         struct tm *lt;
 190         struct passwd *pw;
 191         struct stat sbuf;
 192         time_t now;
 193         FILE *fp;
 194         int fd;
 195         char *p, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
 196         const char *tty;
 197         const char *whom;
 198         gid_t egid;
 199
 200         (void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
 201         if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
 202                 err(1, "can't open temporary file");
 203         (void)unlink(tmpname);
 204
 205         if (!nobanner) {
 206                 tty = ttyname(STDERR_FILENO);
 207                 if (tty == NULL)
 208                         tty = "no tty";
 209
 210                 if (!(whom = getlogin()))
 211                         whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 212                 (void)gethostname(hostname, sizeof(hostname));
 213                 (void)time(&now);
 214                 lt = localtime(&now);
 215
 216                 /*
 217                  * all this stuff is to blank out a square for the message;
 218                  * we wrap message lines at column 79, not 80, because some
 219                  * terminals wrap after 79, some do not, and we can't tell.
 220                  * Which means that we may leave a non-blank character
 221                  * in column 80, but that can't be helped.
 222                  */
 223                 (void)fprintf(fp, "\r%79s\r\n", " ");
 224                 (void)snprintf(lbuf, sizeof(lbuf),
 225                     "Broadcast Message from %s@%s",
 226                     whom, hostname);
 227                 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
 228                 (void)snprintf(lbuf, sizeof(lbuf),
 229                     "        (%s) at %d:%02d %s...", tty,
 230                     lt->tm_hour, lt->tm_min, lt->tm_zone);
 231                 (void)fprintf(fp, "%-79.79s\r\n", lbuf);
 232         }
 233         (void)fprintf(fp, "%79s\r\n", " ");
 234
 235         if (fname) {
 236                 egid = getegid();
 237                 setegid(getgid());
 238                 if (freopen(fname, "r", stdin) == NULL)
 239                         err(1, "can't read %s", fname);
 240                 setegid(egid);
 241         }
 242         cnt = 0;
 243         while (fgets(lbuf, sizeof(lbuf), stdin)) {
 244                 for (p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
 245                         if (ch == '\r') {
 246                                 putc('\r', fp);
 247                                 cnt = 0;
 248                                 continue;
 249                         } else if (ch == '\n') {
 250                                 for (; cnt < 79; ++cnt)
 251                                         putc(' ', fp);
 252                                 putc('\r', fp);
 253                                 putc('\n', fp);
 254                                 break;
 255                         }
 256                         if (cnt == 79) {
 257                                 putc('\r', fp);
 258                                 putc('\n', fp);
 259                                 cnt = 0;
 260                         }
 261                         if (((ch & 0x80) && ch < 0xA0) ||
 262                                    /* disable upper controls */
 263                                    (!isprint(ch) && !isspace(ch) &&
 264                                     ch != '\a' && ch != '\b')
 265                                   ) {
 266                                 if (ch & 0x80) {
 267                                         ch &= 0x7F;
 268                                         putc('M', fp);
 269                                         if (++cnt == 79) {
 270                                                 putc('\r', fp);
 271                                                 putc('\n', fp);
 272                                                 cnt = 0;
 273                                         }
 274                                         putc('-', fp);
 275                                         if (++cnt == 79) {
 276                                                 putc('\r', fp);
 277                                                 putc('\n', fp);
 278                                                 cnt = 0;
 279                                         }
 280                                 }
 281                                 if (iscntrl(ch)) {
 282                                         ch ^= 040;
 283                                         putc('^', fp);
 284                                         if (++cnt == 79) {
 285                                                 putc('\r', fp);
 286                                                 putc('\n', fp);
 287                                                 cnt = 0;
 288                                         }
 289                                 }
 290                         }
 291                         putc(ch, fp);
 292                 }
 293         }
 294         (void)fprintf(fp, "%79s\r\n", " ");
 295         rewind(fp);
 296
 297         if (fstat(fd, &sbuf))
 298                 err(1, "can't stat temporary file");
 299         mbufsize = sbuf.st_size;
 300         if (!(mbuf = malloc((u_int)mbufsize)))
 301                 err(1, "out of memory");
 302         if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
 303                 err(1, "can't read temporary file");
 304         (void)close(fd);
 305 }