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 #include <wchar.h>
  66 #include <wctype.h>
  67
  68 #include "ttymsg.h"
  69
  70 static void makemsg(char *);
  71 static void usage(void);
  72
  73 static struct wallgroup {
  74         struct wallgroup *next;
  75         char            *name;
  76         gid_t           gid;
  77 } *grouplist;
  78 static int nobanner;
  79 static int mbufsize;
  80 static char *mbuf;
  81
  82 static int
  83 ttystat(char *line)
  84 {
  85         struct stat sb;
  86         char ttybuf[MAXPATHLEN];
  87
  88         (void)snprintf(ttybuf, sizeof(ttybuf), "%s%s", _PATH_DEV, line);
  89         if (stat(ttybuf, &sb) == 0) {
  90                 return (0);
  91         } else
  92                 return (-1);
  93 }
  94
  95 int
  96 main(int argc, char *argv[])
  97 {
  98         struct iovec iov;
  99         struct utmpx *utmp;
 100         int ch;
 101         int ingroup;
 102         struct wallgroup *g;
 103         struct group *grp;
 104         char **np;
 105         const char *p;
 106         struct passwd *pw;
 107
 108         (void)setlocale(LC_CTYPE, "");
 109
 110         while ((ch = getopt(argc, argv, "g:n")) != -1)
 111                 switch (ch) {
 112                 case 'n':
 113                         /* undoc option for shutdown: suppress banner */
 114                         if (geteuid() == 0)
 115                                 nobanner = 1;
 116                         break;
 117                 case 'g':
 118                         g = (struct wallgroup *)malloc(sizeof *g);
 119                         g->next = grouplist;
 120                         g->name = optarg;
 121                         g->gid = -1;
 122                         grouplist = g;
 123                         break;
 124                 case '?':
 125                 default:
 126                         usage();
 127                 }
 128         argc -= optind;
 129         argv += optind;
 130         if (argc > 1)
 131                 usage();
 132
 133         for (g = grouplist; g; g = g->next) {
 134                 grp = getgrnam(g->name);
 135                 if (grp != NULL)
 136                         g->gid = grp->gr_gid;
 137                 else
 138                         warnx("%s: no such group", g->name);
 139         }
 140
 141         makemsg(*argv);
 142
 143         iov.iov_base = mbuf;
 144         iov.iov_len = mbufsize;
 145         /* NOSTRICT */
 146         while ((utmp = getutxent()) != NULL) {
 147                 if (utmp->ut_type != USER_PROCESS)
 148                         continue;
 149                 if (ttystat(utmp->ut_line) != 0)
 150                         continue;
 151                 if (grouplist) {
 152                         ingroup = 0;
 153                         pw = getpwnam(utmp->ut_user);
 154                         if (!pw)
 155                                 continue;
 156                         for (g = grouplist; g && ingroup == 0; g = g->next) {
 157                                 if (g->gid == (gid_t)-1)
 158                                         continue;
 159                                 if (g->gid == pw->pw_gid)
 160                                         ingroup = 1;
 161                                 else if ((grp = getgrgid(g->gid)) != NULL) {
 162                                         for (np = grp->gr_mem; *np; np++) {
 163                                                 if (strcmp(*np, utmp->ut_user) == 0) {
 164                                                         ingroup = 1;
 165                                                         break;
 166                                                 }
 167                                         }
 168                                 }
 169                         }
 170                         if (ingroup == 0)
 171                                 continue;
 172                 }
 173                 if ((p = ttymsg(&iov, 1, utmp->ut_line, 60*5)) != NULL)
 174                         warnx("%s", p);
 175         }
 176         exit(0);
 177 }
 178
 179 static void
 180 usage(void)
 181 {
 182         (void)fprintf(stderr, "usage: wall [-g group] [file]\n");
 183         exit(1);
 184 }
 185
 186 void
 187 makemsg(char *fname)
 188 {
 189         int cnt;
 190         wchar_t ch;
 191         struct tm *lt;
 192         struct passwd *pw;
 193         struct stat sbuf;
 194         time_t now;
 195         FILE *fp;
 196         int fd;
 197         char hostname[MAXHOSTNAMELEN], tmpname[64];
 198         wchar_t *p, *tmp, lbuf[256], codebuf[13];
 199         const char *tty;
 200         const char *whom;
 201         gid_t egid;
 202
 203         (void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
 204         if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
 205                 err(1, "can't open temporary file");
 206         (void)unlink(tmpname);
 207
 208         if (!nobanner) {
 209                 tty = ttyname(STDERR_FILENO);
 210                 if (tty == NULL)
 211                         tty = "no tty";
 212
 213                 if (!(whom = getlogin()))
 214                         whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
 215                 (void)gethostname(hostname, sizeof(hostname));
 216                 (void)time(&now);
 217                 lt = localtime(&now);
 218
 219                 /*
 220                  * all this stuff is to blank out a square for the message;
 221                  * we wrap message lines at column 79, not 80, because some
 222                  * terminals wrap after 79, some do not, and we can't tell.
 223                  * Which means that we may leave a non-blank character
 224                  * in column 80, but that can't be helped.
 225                  */
 226                 (void)fwprintf(fp, L"\r%79s\r\n", " ");
 227                 (void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
 228                     L"Broadcast Message from %s@%s",
 229                     whom, hostname);
 230                 (void)fwprintf(fp, L"%-79.79S\007\007\r\n", lbuf);
 231                 (void)swprintf(lbuf, sizeof(lbuf)/sizeof(wchar_t),
 232                     L"        (%s) at %d:%02d %s...", tty,
 233                     lt->tm_hour, lt->tm_min, lt->tm_zone);
 234                 (void)fwprintf(fp, L"%-79.79S\r\n", lbuf);
 235         }
 236         (void)fwprintf(fp, L"%79s\r\n", " ");
 237
 238         if (fname) {
 239                 egid = getegid();
 240                 setegid(getgid());
 241                 if (freopen(fname, "r", stdin) == NULL)
 242                         err(1, "can't read %s", fname);
 243                 if (setegid(egid) != 0)
 244                         err(1, "setegid failed");
 245         }
 246         cnt = 0;
 247         while (fgetws(lbuf, sizeof(lbuf)/sizeof(wchar_t), stdin)) {
 248                 for (p = lbuf; (ch = *p) != L'\0'; ++p, ++cnt) {
 249                         if (ch == L'\r') {
 250                                 putwc(L'\r', fp);
 251                                 cnt = 0;
 252                                 continue;
 253                         } else if (ch == L'\n') {
 254                                 for (; cnt < 79; ++cnt)
 255                                         putwc(L' ', fp);
 256                                 putwc(L'\r', fp);
 257                                 putwc(L'\n', fp);
 258                                 break;
 259                         }
 260                         if (cnt == 79) {
 261                                 putwc(L'\r', fp);
 262                                 putwc(L'\n', fp);
 263                                 cnt = 0;
 264                         }
 265                         if (iswprint(ch) || iswspace(ch) || ch == L'\a' || ch == L'\b') {
 266                                 putwc(ch, fp);
 267                         } else {
 268                                 (void)swprintf(codebuf, sizeof(codebuf)/sizeof(wchar_t), L"<0x%X>", ch);
 269                                 for (tmp = codebuf; *tmp != L'\0'; ++tmp) {
 270                                         putwc(*tmp, fp);
 271                                         if (++cnt == 79) {
 272                                                 putwc(L'\r', fp);
 273                                                 putwc(L'\n', fp);
 274                                                 cnt = 0;
 275                                         }
 276                                 }
 277                                 --cnt;
 278                         }
 279                 }
 280         }
 281         (void)fwprintf(fp, L"%79s\r\n", " ");
 282         rewind(fp);
 283
 284         if (fstat(fd, &sbuf))
 285                 err(1, "can't stat temporary file");
 286         mbufsize = sbuf.st_size;
 287         if (!(mbuf = malloc((u_int)mbufsize)))
 288                 err(1, "out of memory");
 289         if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
 290                 err(1, "can't read temporary file");
 291         (void)close(fd);
 292 }