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  * 3. 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  * @(#) Copyright (c) 1988, 1990, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)wall.c   8.2 (Berkeley) 11/16/93
  31  * $FreeBSD: src/usr.bin/wall/wall.c,v 1.13.2.6 2001/10/18 08:08:17 des Exp $
  32  */
  33
  34 /*
  35  * This program is not related to David Wall, whose Stanford Ph.D. thesis
  36  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/stat.h>
  41 #include <sys/uio.h>
  42
  43 #include <ctype.h>
  44 #include <err.h>
  45 #include <grp.h>
  46 #include <locale.h>
  47 #include <paths.h>
  48 #include <pwd.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <time.h>
  53 #include <unistd.h>
  54 #include "utmpentry.h"
  55
  56 #include "ttymsg.h"
  57
  58 static void makemsg(char *);
  59 static void usage(void);
  60
  61 static struct wallgroup {
  62         struct wallgroup *next;
  63         char            *name;
  64         gid_t           gid;
  65 } *grouplist;
  66 static int nobanner;
  67 static int mbufsize;
  68 static char *mbuf;
  69
  70 int
  71 main(int argc, char *argv[])
  72 {
  73         struct iovec iov;
  74         struct utmpentry *ep = NULL;    /* avoid gcc warnings */
  75         int ch;
  76         int ingroup;
  77         struct wallgroup *g;
  78         struct group *grp;
  79         char **np;
  80         const char *p;
  81         struct passwd *pw;
  82
  83         (void)setlocale(LC_CTYPE, "");
  84
  85         while ((ch = getopt(argc, argv, "g:n")) != -1)
  86                 switch (ch) {
  87                 case 'n':
  88                         /* undoc option for shutdown: suppress banner */
  89                         if (geteuid() == 0)
  90                                 nobanner = 1;
  91                         break;
  92                 case 'g':
  93                         g = (struct wallgroup *)malloc(sizeof *g);
  94                         g->next = grouplist;
  95                         g->name = optarg;
  96                         g->gid = -1;
  97                         grouplist = g;
  98                         break;
  99                 case '?':
 100                 default:
 101                         usage();
 102                 }
 103         argc -= optind;
 104         argv += optind;
 105         if (argc > 1)
 106                 usage();
 107
 108         for (g = grouplist; g; g = g->next) {
 109                 grp = getgrnam(g->name);
 110                 if (grp != NULL)
 111                         g->gid = grp->gr_gid;
 112                 else
 113                         warnx("%s: no such group", g->name);
 114         }
 115
 116         makemsg(*argv);
 117
 118         iov.iov_base = mbuf;
 119         iov.iov_len = mbufsize;
 120
 121         getutentries(NULL, &ep);
 122         /* NOSTRICT */
 123         for (; ep; ep = ep->next) {
 124                 if (grouplist) {
 125                         ingroup = 0;
 126                         pw = getpwnam(ep->name);
 127                         if (!pw)
 128                                 continue;
 129                         for (g = grouplist; g && ingroup == 0; g = g->next) {
 130                                 if (g->gid == (gid_t)-1)
 131                                         continue;
 132                                 if (g->gid == pw->pw_gid)
 133                                         ingroup = 1;
 134                                 else if ((grp = getgrgid(g->gid)) != NULL) {
 135                                         for (np = grp->gr_mem; *np; np++) {
 136                                                 if (strcmp(*np, ep->name) == 0) {
 137                                                         ingroup = 1;
 138                                                         break;
 139                                                 }
 140                                         }
 141                                 }
 142                         }
 143                         if (ingroup == 0)
 144                                 continue;
 145                 }
 146                 /* skip [xgk]dm/xserver entries (":0", ":1", etc.) */
 147                 if (ep->line[0] == ':' && isdigit((unsigned char)ep->line[1]))
 148                         continue;
 149
 150                 if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL)
 151                         warnx("%s", p);
 152         }
 153         exit(0);
 154 }
 155
 156 static void
 157 usage(void)
 158 {
 159         (void)fprintf(stderr, "usage: wall [-g group] [file]\n");
 160         exit(1);
 161 }
 162
 163 void
 164 makemsg(char *fname)
 165 {
 166         int cnt;
 167         unsigned char ch;
 168         struct tm *lt;
 169         struct passwd *pw;
 170         struct stat sbuf;
 171         time_t now;
 172         FILE *fp;
 173         int fd;
 174         char *p, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[MAXPATHLEN];
 175         const char *tty;
 176         const char *whom;
 177         gid_t egid;
 178
 179         (void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
 180         if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
 181                 err(1, "can't open temporary file");
 182         (void)unlink(tmpname);
 183
 184         if (!nobanner) {
 185                 tty = ttyname(STDERR_FILENO);
 186                 if (tty == NULL)
 187                         tty = "no tty";
 188
 189                 if (!(whom = getlogin()))
 190                         whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 191                 (void)gethostname(hostname, sizeof(hostname));
 192                 (void)time(&now);
 193                 lt = localtime(&now);
 194
 195                 /*
 196                  * all this stuff is to blank out a square for the message;
 197                  * we wrap message lines at column 79, not 80, because some
 198                  * terminals wrap after 79, some do not, and we can't tell.
 199                  * Which means that we may leave a non-blank character
 200                  * in column 80, but that can't be helped.
 201                  */
 202                 (void)fprintf(fp, "\r%79s\r\n", " ");
 203                 (void)snprintf(lbuf, sizeof(lbuf),
 204                     "Broadcast Message from %s@%s",
 205                     whom, hostname);
 206                 (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf);
 207                 (void)snprintf(lbuf, sizeof(lbuf),
 208                     "        (%s) at %d:%02d %s...", tty,
 209                     lt->tm_hour, lt->tm_min, lt->tm_zone);
 210                 (void)fprintf(fp, "%-79.79s\r\n", lbuf);
 211         }
 212         (void)fprintf(fp, "%79s\r\n", " ");
 213
 214         if (fname) {
 215                 egid = getegid();
 216                 setegid(getgid());
 217                 if (freopen(fname, "r", stdin) == NULL)
 218                         err(1, "can't read %s", fname);
 219                 setegid(egid);
 220         }
 221         while (fgets(lbuf, sizeof(lbuf), stdin))
 222                 for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
 223                         if (ch == '\r') {
 224                                 cnt = 0;
 225                         } else if (cnt == 79 || ch == '\n') {
 226                                 for (; cnt < 79; ++cnt)
 227                                         putc(' ', fp);
 228                                 putc('\r', fp);
 229                                 putc('\n', fp);
 230                                 cnt = 0;
 231                         } else if (((ch & 0x80) && ch < 0xA0) ||
 232                                    /* disable upper controls */
 233                                    (!isprint(ch) && !isspace(ch) &&
 234                                     ch != '\a' && ch != '\b')
 235                                   ) {
 236                                 if (ch & 0x80) {
 237                                         ch &= 0x7F;
 238                                         putc('M', fp);
 239                                         if (++cnt == 79) {
 240                                                 putc('\r', fp);
 241                                                 putc('\n', fp);
 242                                                 cnt = 0;
 243                                         }
 244                                         putc('-', fp);
 245                                         if (++cnt == 79) {
 246                                                 putc('\r', fp);
 247                                                 putc('\n', fp);
 248                                                 cnt = 0;
 249                                         }
 250                                 }
 251                                 if (iscntrl(ch)) {
 252                                         ch ^= 040;
 253                                         putc('^', fp);
 254                                         if (++cnt == 79) {
 255                                                 putc('\r', fp);
 256                                                 putc('\n', fp);
 257                                                 cnt = 0;
 258                                         }
 259                                 }
 260                                 putc(ch, fp);
 261                         } else {
 262                                 putc(ch, fp);
 263                         }
 264                 }
 265         (void)fprintf(fp, "%79s\r\n", " ");
 266         rewind(fp);
 267
 268         if (fstat(fd, &sbuf))
 269                 err(1, "can't stat temporary file");
 270         mbufsize = sbuf.st_size;
 271         if (!(mbuf = malloc((u_int)mbufsize)))
 272                 err(1, "out of memory");
 273         if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
 274                 err(1, "can't read temporary file");
 275         (void)close(fd);
 276 }