git.marmaro.de Git - mmh/blob - uip/rcvtty.c

   1 /*
   2 ** rcvtty.c -- a rcvmail program (a lot like rcvalert) handling IPC ttys
   3 **
   4 ** This code is Copyright (c) 2002, by the authors of nmh.  See the
   5 ** COPYRIGHT file in the root directory of the nmh distribution for
   6 ** complete copyright information.
   7 */
   8
   9 /* Changed to use getutent() and friends.  Assumes that when getutent() exists,
  10 ** a number of other things also exist.  Please check.
  11 ** Ruud de Rooij <ruud@ruud.org>  Sun, 28 May 2000 17:28:55 +0200
  12 */
  13
  14 #include <h/mh.h>
  15 #include <h/signals.h>
  16 #include <h/rcvmail.h>
  17 #include <h/scansbr.h>
  18 #include <h/tws.h>
  19 #include <signal.h>
  20 #include <fcntl.h>
  21
  22 #include <utmp.h>
  23
  24 #ifndef HAVE_GETUTENT
  25 # ifndef UTMP_FILE
  26 #  ifdef _PATH_UTMP
  27 #   define UTMP_FILE _PATH_UTMP
  28 #  else
  29 #   define UTMP_FILE "/etc/utmp"
  30 #  endif
  31 # endif
  32 #endif
  33
  34 #define SCANFMT \
  35 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  36 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  37 %{subject}"
  38
  39 static struct swit switches[] = {
  40 #define BIFFSW  0
  41         { "biff", 0 },
  42 #define FORMSW  1
  43         { "form formatfile", 0 },
  44 #define FMTSW  2
  45         { "format string", 5 },
  46 #define WIDTHSW 3
  47         { "width columns", 0 },
  48 #define NLSW  4
  49         { "newline", 0 },
  50 #define NNLSW   5
  51         { "nonewline", 0 },
  52 #define BELSW  6
  53         { "bell", 0 },
  54 #define NBELSW  7
  55         { "nobell", 0 },
  56 #define VERSIONSW 8
  57         { "version", 0 },
  58 #define HELPSW  9
  59         { "help", 0 },
  60         { NULL, 0 }
  61 };
  62
  63 static jmp_buf myctx;
  64 static int bell = 1;
  65 static int newline = 1;
  66 static int biff = 0;
  67 static int width = 0;
  68 static char *form = NULL;
  69 static char *format = NULL;
  70
  71 /*
  72 ** static prototypes
  73 */
  74 static RETSIGTYPE alrmser(int);
  75 static int message_fd(char **);
  76 static int header_fd(void);
  77 static void alert(char *, int);
  78
  79
  80 int
  81 main(int argc, char **argv)
  82 {
  83         int md, vecp = 0;
  84         char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  85         char **argp, **arguments, *vec[MAXARGS];
  86 #ifdef HAVE_GETUTENT
  87         struct utmp * utp;
  88 #else
  89         struct utmp ut;
  90         register FILE *uf;
  91 #endif
  92
  93 #ifdef LOCALE
  94         setlocale(LC_ALL, "");
  95 #endif
  96         invo_name = mhbasename(argv[0]);
  97
  98         /* read user profile/context */
  99         context_read();
 100
 101         arguments = getarguments(invo_name, argc, argv, 1);
 102         argp = arguments;
 103
 104         while ((cp = *argp++)) {
 105                 if (*cp == '-') {
 106                         switch (smatch(++cp, switches)) {
 107                         case AMBIGSW:
 108                                 ambigsw(cp, switches);
 109                                 done(1);
 110                         case UNKWNSW:
 111                                 vec[vecp++] = --cp;
 112                                 continue;
 113
 114                         case HELPSW:
 115                                 snprintf(buf, sizeof(buf), "%s [command ...]",
 116                                                 invo_name);
 117                                 print_help(buf, switches, 1);
 118                                 done(1);
 119                         case VERSIONSW:
 120                                 print_version(invo_name);
 121                                 done(1);
 122
 123                         case BIFFSW:
 124                                 biff = 1;
 125                                 continue;
 126
 127                         case FORMSW:
 128                                 if (!(form = *argp++) || *form == '-')
 129                                         adios(NULL, "missing argument to %s",
 130                                                         argp[-2]);
 131                                 format = NULL;
 132                                 continue;
 133                         case FMTSW:
 134                                 if (!(format = *argp++) || *format == '-')
 135                                         adios(NULL, "missing argument to %s",
 136                                                         argp[-2]);
 137                                 form = NULL;
 138                                 continue;
 139
 140                         case WIDTHSW:
 141                                 if (!(cp = *argp++) || *cp == '-')
 142                                         adios(NULL, "missing argument to %s",
 143                                                         argp[-2]);
 144                                 width = atoi(cp);
 145                                 continue;
 146                         case NLSW:
 147                                 newline = 1;
 148                                 continue;
 149                         case NNLSW:
 150                                 newline = 0;
 151                                 continue;
 152                         case BELSW:
 153                                 bell = 1;
 154                                 continue;
 155                         case NBELSW:
 156                                 bell = 0;
 157                                 continue;
 158
 159                         }
 160                 }
 161                 vec[vecp++] = cp;
 162         }
 163         vec[vecp] = 0;
 164
 165         if ((md = vecp ? message_fd(vec) : header_fd()) == NOTOK)
 166                 exit(RCV_MBX);
 167
 168         user = getusername();
 169
 170 #ifdef HAVE_GETUTENT
 171         setutent();
 172         while ((utp = getutent()) != NULL) {
 173                 if (
 174 #ifdef HAVE_STRUCT_UTMP_UT_TYPE
 175                                 utp->ut_type == USER_PROCESS &&
 176 #endif
 177                                 utp->ut_name[0] != 0 && utp->ut_line[0] != 0
 178                                 && strncmp(user, utp->ut_name,
 179                                 sizeof(utp->ut_name)) == 0) {
 180                         strncpy(tty, utp->ut_line, sizeof(utp->ut_line));
 181                         alert(tty, md);
 182                 }
 183         }
 184         endutent();
 185 #else
 186         if ((uf = fopen(UTMP_FILE, "r")) == NULL)
 187                 exit(RCV_MBX);
 188         while (fread((char *) &ut, sizeof(ut), 1, uf) == 1)
 189                 if (ut.ut_name[0] != 0 &&
 190                                 strncmp(user, ut.ut_name, sizeof(ut.ut_name))
 191                                 == 0) {
 192                         strncpy(tty, ut.ut_line, sizeof(ut.ut_line));
 193                         alert(tty, md);
 194                 }
 195         fclose(uf);
 196 #endif
 197
 198         exit(RCV_MOK);
 199         return 0;  /* dead code to satisfy the compiler */
 200 }
 201
 202
 203 static RETSIGTYPE
 204 alrmser(int i)
 205 {
 206 #ifndef RELIABLE_SIGNALS
 207         SIGNAL(SIGALRM, alrmser);
 208 #endif
 209
 210         longjmp(myctx, 1);
 211 }
 212
 213
 214 static int
 215 message_fd(char **vec)
 216 {
 217         pid_t child_id;
 218         int bytes, fd, seconds;
 219         char tmpfil[BUFSIZ];
 220         struct stat st;
 221
 222 #ifdef HAVE_MKSTEMP
 223         fd = mkstemp(strncpy(tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 224 #else
 225         unlink(mktemp(strncpy(tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 226         if ((fd = open(tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 227                 return header_fd();
 228 #endif
 229         unlink(tmpfil);
 230
 231         if ((child_id = fork()) == NOTOK) {
 232                 /* fork error */
 233                 close(fd);
 234                 return header_fd();
 235         } else if (child_id) {
 236                 /* parent process */
 237                 if (!setjmp(myctx)) {
 238                         SIGNAL(SIGALRM, alrmser);
 239                         bytes = fstat(fileno(stdin), &st) != NOTOK ?
 240                                         (int) st.st_size : 100;
 241
 242                         /* amount of time to wait depends on message size */
 243                         if (bytes <= 100) {
 244                                 /* give at least 5 minutes */
 245                                 seconds = 300;
 246                         } else if (bytes >= 90000) {
 247                                 /* but 30 minutes should be long enough */
 248                                 seconds = 1800;
 249                         } else {
 250                                 seconds = (bytes / 60) + 300;
 251                         }
 252                         alarm((unsigned int) seconds);
 253                         pidwait(child_id, OK);
 254                         alarm(0);
 255
 256                         if (fstat(fd, &st) != NOTOK && st.st_size > (off_t) 0)
 257                                 return fd;
 258                 } else {
 259                         /*
 260                         ** Ruthlessly kill the child and anything
 261                         ** else in its process group.
 262                         */
 263                         KILLPG(child_id, SIGKILL);
 264                 }
 265                 close(fd);
 266                 return header_fd();
 267         }
 268
 269         /* child process */
 270         rewind(stdin);
 271         if (dup2(fd, 1) == NOTOK || dup2(fd, 2) == NOTOK)
 272                 _exit(-1);
 273         closefds(3);
 274         setpgid((pid_t) 0, getpid());  /* put in own process group */
 275         execvp(vec[0], vec);
 276         _exit(-1);
 277         return 1;  /* dead code to satisfy compiler */
 278 }
 279
 280
 281 static int
 282 header_fd(void)
 283 {
 284         int fd;
 285         char *nfs;
 286         char *tfile = NULL;
 287
 288         tfile = m_mktemp2(NULL, invo_name, &fd, NULL);
 289         if (tfile == NULL) return NOTOK;
 290         unlink(tfile);
 291
 292         rewind(stdin);
 293
 294         /* get new format string */
 295         nfs = new_fs(form, format, NULL, SCANFMT);
 296         scan(stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 297         if (newline)
 298                 write(fd, "\n\r", 2);
 299         write(fd, scanl, strlen(scanl));
 300         if (bell)
 301                 write(fd, "\007", 1);
 302
 303         return fd;
 304 }
 305
 306
 307 static void
 308 alert(char *tty, int md)
 309 {
 310         int i, td, mask;
 311         char buffer[BUFSIZ], ttyspec[BUFSIZ];
 312         struct stat st;
 313
 314         snprintf(ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 315
 316         /*
 317         ** The mask depends on whether we are checking for
 318         ** write permission based on `biff' or `mesg'.
 319         */
 320         mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 321         if (stat(ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 322                 return;
 323
 324         if (!setjmp(myctx)) {
 325                 SIGNAL(SIGALRM, alrmser);
 326                 alarm(2);
 327                 td = open(ttyspec, O_WRONLY);
 328                 alarm(0);
 329                 if (td == NOTOK)
 330                         return;
 331         } else {
 332                 alarm(0);
 333                 return;
 334         }
 335
 336         lseek(md, (off_t) 0, SEEK_SET);
 337
 338         while ((i = read(md, buffer, sizeof(buffer))) > 0)
 339                 if (write(td, buffer, i) != i)
 340                         break;
 341
 342         close(td);
 343 }