usr.bin/wall/wall.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   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. 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  * This program is not related to David Wall, whose Stanford Ph.D. thesis
  34  * is entitled "Mechanisms for Broadcast and Selective Broadcast".
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/stat.h>
  39 #include <sys/uio.h>
  40
  41 #include <ctype.h>
  42 #include <err.h>
  43 #include <grp.h>
  44 #include <locale.h>
  45 #include <paths.h>
  46 #include <pwd.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <time.h>
  51 #include <unistd.h>
  52 #include <utmpx.h>
  53 #include <wchar.h>
  54 #include <wctype.h>
  55
  56 #include "ttymsg.h"
  57
  58 static void makemsg(char *);
  59 static void usage(void) __dead2;
  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 static int
  71 ttystat(char *line)
  72 {
  73         struct stat sb;
  74         char ttybuf[MAXPATHLEN];
  75
  76         (void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
  77         if (stat(ttybuf, &sb) == 0) {
  78                 return (0);
  79         } else
  80                 return (-1);
  81 }
  82
  83 int
  84 main(int argc, char *argv[])
  85 {
  86         struct iovec iov;
  87         struct utmpx *utmp;
  88         int ch;
  89         int ingroup;
  90         struct wallgroup *g;
  91         struct group *grp;
  92         char **np;
  93         const char *p;
  94         struct passwd *pw;
  95
  96         (void)setlocale(LC_CTYPE, "");
  97
  98         while ((ch = getopt(argc, argv, "g:n")) != -1)
  99                 switch (ch) {
 100                 case 'n':
 101                         /* undoc option for shutdown: suppress banner */
 102                         if (geteuid() == 0)
 103                                 nobanner = 1;
 104                         break;
 105                 case 'g':
 106                         g = (struct wallgroup *)malloc(sizeof *g);
 107                         g->next = grouplist;
 108                         g->name = optarg;
 109                         g->gid = -1;
 110                         grouplist = g;
 111                         break;
 112                 case '?':
 113                 default:
 114                         usage();
 115                 }
 116         argc -= optind;
 117         argv += optind;
 118         if (argc > 1)
 119                 usage();
 120
 121         for (g = grouplist; g; g = g->next) {
 122                 grp = getgrnam(g->name);
 123                 if (grp != NULL)
 124                         g->gid = grp->gr_gid;
 125                 else
 126                         warnx("%s: no such group", g->name);
 127         }
 128
 129         makemsg(*argv);
 130
 131         iov.iov_base = mbuf;
 132         iov.iov_len = mbufsize;
 133         /* NOSTRICT */
 134         while ((utmp = getutxent()) != NULL) {
 135                 if (utmp->ut_type != USER_PROCESS)
 136                         continue;
 137                 if (ttystat(utmp->ut_line) != 0)
 138                         continue;
 139                 if (grouplist) {
 140                         ingroup = 0;
 141                         pw = getpwnam(utmp->ut_user);
 142                         if (!pw)
 143                                 continue;
 144                         for (g = grouplist; g && ingroup == 0; g = g->next) {
 145                                 if (g->gid == (gid_t)-1)
 146                                         continue;
 147                                 if (g->gid == pw->pw_gid)
 148                                         ingroup = 1;
 149                                 else if ((grp = getgrgid(g->gid)) != NULL) {
 150                                         for (np = grp->gr_mem; *np; np++) {
 151                                                 if (strcmp(*np, utmp->ut_user) == 0) {
 152                                                         ingroup = 1;
 153                                                         break;
 154                                                 }
 155                                         }
 156                                 }
 157                         }
 158                         if (ingroup == 0)
 159                                 continue;
 160                 }
 161                 if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
 162                         warnx("%s", p);
 163         }
 164         exit(0);
 165 }
 166
 167 static void
 168 usage(void)
 169 {
 170         (void)fprintf(stderr, "usage: wall [-g group] [file]\n");
 171         exit(1);
 172 }
 173
 174 void
 175 makemsg(char *fname)
 176 {
 177         int cnt;
 178         wchar_t ch;
 179         struct tm *lt;
 180         struct passwd *pw;
 181         struct stat sbuf;
 182         time_t now;
 183         FILE *fp;
 184         int fd;
 185         char hostname[MAXHOSTNAMELEN], tmpname[64];
 186         wchar_t *p, *tmp, lbuf[256], codebuf[13];
 187         const char *tty;
 188         const char *whom;
 189         gid_t egid;
 190
 191         (void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
 192         if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
 193                 err(1, "can't open temporary file");
 194         (void)unlink(tmpname);
 195
 196         if (!nobanner) {
 197                 tty = ttyname(STDERR_FILENO);
 198                 if (tty == NULL)
 199                         tty = "no tty";
 200
 201                 if (!(whom = getlogin()))
 202                         whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 203                 (void)gethostname(hostname, sizeof(hostname));
 204                 (void)time(&now);
 205                 lt = localtime(&now);
 206
 207                 /*
 208                  * all this stuff is to blank out a square for the message;
 209                  * we wrap message lines at column 79, not 80, because some
 210                  * terminals wrap after 79, some do not, and we can't tell.
 211                  * Which means that we may leave a non-blank character
 212                  * in column 80, but that can't be helped.
 213                  */
 214                 (void)fwprintf(fp, L"\r%79s\r\n", " ");
 215                 (void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
 216                     L"Broadcast Message from %s@%s",
 217                     whom, hostname);
 218                 (void)fwprintf(fp, L"%-79.79S\007\007\r\n", lbuf);
 219                 (void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
 220                     L"        (%s) at %d:%02d %s...", tty,
 221                     lt->tm_hour, lt->tm_min, lt->tm_zone);
 222                 (void)fwprintf(fp, L"%-79.79S\r\n", lbuf);
 223         }
 224         (void)fwprintf(fp, L"%79s\r\n", " ");
 225
 226         if (fname) {
 227                 egid = getegid();
 228                 setegid(getgid());
 229                 if (freopen(fname, "r", stdin) == NULL)
 230                         err(1, "can't read %s", fname);
 231                 if (setegid(egid) != 0)
 232                         err(1, "setegid failed");
 233         }
 234         cnt = 0;
 235         while (fgetws(lbuf, sizeof(lbuf)/sizeof(wchar_t), stdin)) {
 236                 for (p = lbuf; (ch = *p) != L'\0'; ++p, ++cnt) {
 237                         if (ch == L'\r') {
 238                                 putwc(L'\r', fp);
 239                                 cnt = 0;
 240                                 continue;
 241                         } else if (ch == L'\n') {
 242                                 for (; cnt < 79; ++cnt)
 243                                         putwc(L' ', fp);
 244                                 putwc(L'\r', fp);
 245                                 putwc(L'\n', fp);
 246                                 break;
 247                         }
 248                         if (cnt == 79) {
 249                                 putwc(L'\r', fp);
 250                                 putwc(L'\n', fp);
 251                                 cnt = 0;
 252                         }
 253                         if (iswprint(ch) || iswspace(ch) || ch == L'\a' || ch == L'\b') {
 254                                 putwc(ch, fp);
 255                         } else {
 256                                 (void)swprintf(codebuf, sizeof(codebuf)/sizeof(wchar_t), L"<0x%X>", ch);
 257                                 for (tmp = codebuf; *tmp != L'\0'; ++tmp) {
 258                                         putwc(*tmp, fp);
 259                                         if (++cnt == 79) {
 260                                                 putwc(L'\r', fp);
 261                                                 putwc(L'\n', fp);
 262                                                 cnt = 0;
 263                                         }
 264                                 }
 265                                 --cnt;
 266                         }
 267                 }
 268         }
 269         (void)fwprintf(fp, L"%79s\r\n", " ");
 270         rewind(fp);
 271
 272         if (fstat(fd, &sbuf))
 273                 err(1, "can't stat temporary file");
 274         mbufsize = sbuf.st_size;
 275         if (!(mbuf = malloc((u_int)mbufsize)))
 276                 err(1, "out of memory");
 277         if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
 278                 err(1, "can't read temporary file");
 279         fclose(fp);
 280 }