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 <h/mts.h>
  20 #include <signal.h>
  21 #include <fcntl.h>
  22
  23 #include <utmp.h>
  24
  25 #ifndef HAVE_GETUTENT
  26 # ifndef UTMP_FILE
  27 #  ifdef _PATH_UTMP
  28 #   define UTMP_FILE _PATH_UTMP
  29 #  else
  30 #   define UTMP_FILE "/etc/utmp"
  31 #  endif
  32 # endif
  33 #endif
  34
  35 #define SCANFMT \
  36 "%2(hour{dtimenow}):%02(min{dtimenow}): %<(size)%5(size) %>%<{encrypted}E%>\
  37 %<(mymbox{from})%<{to}To:%14(friendly{to})%>%>%<(zero)%17(friendly{from})%>  \
  38 %{subject}%<{body}<<%{body}>>%>"
  39
  40 static struct swit switches[] = {
  41 #define BIFFSW  0
  42         { "biff", 0 },
  43 #define FORMSW  1
  44         { "form formatfile", 0 },
  45 #define FMTSW  2
  46         { "format string", 5 },
  47 #define WIDTHSW 3
  48         { "width columns", 0 },
  49 #define NLSW  4
  50         { "newline", 0 },
  51 #define NNLSW   5
  52         { "nonewline", 0 },
  53 #define BELSW  6
  54         { "bell", 0 },
  55 #define NBELSW  7
  56         { "nobell", 0 },
  57 #define VERSIONSW 8
  58         { "version", 0 },
  59 #define HELPSW  9
  60         { "help", 0 },
  61         { NULL, 0 }
  62 };
  63
  64 static jmp_buf myctx;
  65 static int bell = 1;
  66 static int newline = 1;
  67 static int biff = 0;
  68 static int width = 0;
  69 static char *form = NULL;
  70 static char *format = NULL;
  71
  72 /*
  73 ** external prototypes
  74 */
  75 char *getusername(void);
  76
  77 /*
  78 ** static prototypes
  79 */
  80 static RETSIGTYPE alrmser(int);
  81 static int message_fd(char **);
  82 static int header_fd(void);
  83 static void alert(char *, int);
  84
  85
  86 int
  87 main(int argc, char **argv)
  88 {
  89         int md, vecp = 0;
  90         char *cp, *user, buf[BUFSIZ], tty[BUFSIZ];
  91         char **argp, **arguments, *vec[MAXARGS];
  92 #ifdef HAVE_GETUTENT
  93         struct utmp * utp;
  94 #else
  95         struct utmp ut;
  96         register FILE *uf;
  97 #endif
  98
  99 #ifdef LOCALE
 100         setlocale(LC_ALL, "");
 101 #endif
 102         invo_name = mhbasename(argv[0]);
 103
 104         /* read user profile/context */
 105         context_read();
 106
 107         mts_init(invo_name);
 108         arguments = getarguments(invo_name, argc, argv, 1);
 109         argp = arguments;
 110
 111         while ((cp = *argp++)) {
 112                 if (*cp == '-') {
 113                         switch (smatch(++cp, switches)) {
 114                         case AMBIGSW:
 115                                 ambigsw(cp, switches);
 116                                 done(1);
 117                         case UNKWNSW:
 118                                 vec[vecp++] = --cp;
 119                                 continue;
 120
 121                         case HELPSW:
 122                                 snprintf(buf, sizeof(buf), "%s [command ...]",
 123                                                 invo_name);
 124                                 print_help(buf, switches, 1);
 125                                 done(1);
 126                         case VERSIONSW:
 127                                 print_version(invo_name);
 128                                 done(1);
 129
 130                         case BIFFSW:
 131                                 biff = 1;
 132                                 continue;
 133
 134                         case FORMSW:
 135                                 if (!(form = *argp++) || *form == '-')
 136                                         adios(NULL, "missing argument to %s",
 137                                                         argp[-2]);
 138                                 format = NULL;
 139                                 continue;
 140                         case FMTSW:
 141                                 if (!(format = *argp++) || *format == '-')
 142                                         adios(NULL, "missing argument to %s",
 143                                                         argp[-2]);
 144                                 form = NULL;
 145                                 continue;
 146
 147                         case WIDTHSW:
 148                                 if (!(cp = *argp++) || *cp == '-')
 149                                         adios(NULL, "missing argument to %s",
 150                                                         argp[-2]);
 151                                 width = atoi(cp);
 152                                 continue;
 153                         case NLSW:
 154                                 newline = 1;
 155                                 continue;
 156                         case NNLSW:
 157                                 newline = 0;
 158                                 continue;
 159                         case BELSW:
 160                                 bell = 1;
 161                                 continue;
 162                         case NBELSW:
 163                                 bell = 0;
 164                                 continue;
 165
 166                         }
 167                 }
 168                 vec[vecp++] = cp;
 169         }
 170         vec[vecp] = 0;
 171
 172         if ((md = vecp ? message_fd(vec) : header_fd()) == NOTOK)
 173                 exit(RCV_MBX);
 174
 175         user = getusername();
 176
 177 #ifdef HAVE_GETUTENT
 178         setutent();
 179         while ((utp = getutent()) != NULL) {
 180                 if (
 181 #ifdef HAVE_STRUCT_UTMP_UT_TYPE
 182                                 utp->ut_type == USER_PROCESS &&
 183 #endif
 184                                 utp->ut_name[0] != 0 && utp->ut_line[0] != 0
 185                                 && strncmp(user, utp->ut_name,
 186                                 sizeof(utp->ut_name)) == 0) {
 187                         strncpy(tty, utp->ut_line, sizeof(utp->ut_line));
 188                         alert(tty, md);
 189                 }
 190         }
 191         endutent();
 192 #else
 193         if ((uf = fopen(UTMP_FILE, "r")) == NULL)
 194                 exit(RCV_MBX);
 195         while (fread((char *) &ut, sizeof(ut), 1, uf) == 1)
 196                 if (ut.ut_name[0] != 0 &&
 197                                 strncmp(user, ut.ut_name, sizeof(ut.ut_name))
 198                                 == 0) {
 199                         strncpy(tty, ut.ut_line, sizeof(ut.ut_line));
 200                         alert(tty, md);
 201                 }
 202         fclose(uf);
 203 #endif
 204
 205         exit(RCV_MOK);
 206         return 0;  /* dead code to satisfy the compiler */
 207 }
 208
 209
 210 static RETSIGTYPE
 211 alrmser(int i)
 212 {
 213 #ifndef RELIABLE_SIGNALS
 214         SIGNAL(SIGALRM, alrmser);
 215 #endif
 216
 217         longjmp(myctx, 1);
 218 }
 219
 220
 221 static int
 222 message_fd(char **vec)
 223 {
 224         pid_t child_id;
 225         int bytes, fd, seconds;
 226         char tmpfil[BUFSIZ];
 227         struct stat st;
 228
 229 #ifdef HAVE_MKSTEMP
 230         fd = mkstemp(strncpy(tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil)));
 231 #else
 232         unlink(mktemp(strncpy(tmpfil, "/tmp/rcvttyXXXXX", sizeof(tmpfil))));
 233         if ((fd = open(tmpfil, O_RDWR | O_CREAT | O_TRUNC, 0600)) == NOTOK)
 234                 return header_fd();
 235 #endif
 236         unlink(tmpfil);
 237
 238         if ((child_id = vfork()) == NOTOK) {
 239                 /* fork error */
 240                 close(fd);
 241                 return header_fd();
 242         } else if (child_id) {
 243                 /* parent process */
 244                 if (!setjmp(myctx)) {
 245                         SIGNAL(SIGALRM, alrmser);
 246                         bytes = fstat(fileno(stdin), &st) != NOTOK ?
 247                                         (int) st.st_size : 100;
 248
 249                         /* amount of time to wait depends on message size */
 250                         if (bytes <= 100) {
 251                                 /* give at least 5 minutes */
 252                                 seconds = 300;
 253                         } else if (bytes >= 90000) {
 254                                 /* but 30 minutes should be long enough */
 255                                 seconds = 1800;
 256                         } else {
 257                                 seconds = (bytes / 60) + 300;
 258                         }
 259                         alarm((unsigned int) seconds);
 260                         pidwait(child_id, OK);
 261                         alarm(0);
 262
 263                         if (fstat(fd, &st) != NOTOK && st.st_size > (off_t) 0)
 264                                 return fd;
 265                 } else {
 266                         /*
 267                         ** Ruthlessly kill the child and anything
 268                         ** else in its process group.
 269                         */
 270                         KILLPG(child_id, SIGKILL);
 271                 }
 272                 close(fd);
 273                 return header_fd();
 274         }
 275
 276         /* child process */
 277         rewind(stdin);
 278         if (dup2(fd, 1) == NOTOK || dup2(fd, 2) == NOTOK)
 279                 _exit(-1);
 280         closefds(3);
 281         setpgid((pid_t) 0, getpid());  /* put in own process group */
 282         execvp(vec[0], vec);
 283         _exit(-1);
 284         return 1;  /* dead code to satisfy compiler */
 285 }
 286
 287
 288 static int
 289 header_fd(void)
 290 {
 291         int fd;
 292         char *nfs;
 293         char *tfile = NULL;
 294
 295         tfile = m_mktemp2(NULL, invo_name, &fd, NULL);
 296         if (tfile == NULL) return NOTOK;
 297         unlink(tfile);
 298
 299         rewind(stdin);
 300
 301         /* get new format string */
 302         nfs = new_fs(form, format, SCANFMT);
 303         scan(stdin, 0, 0, nfs, width, 0, 0, NULL, 0L, 0);
 304         if (newline)
 305                 write(fd, "\n\r", 2);
 306         write(fd, scanl, strlen(scanl));
 307         if (bell)
 308                 write(fd, "\007", 1);
 309
 310         return fd;
 311 }
 312
 313
 314 static void
 315 alert(char *tty, int md)
 316 {
 317         int i, td, mask;
 318         char buffer[BUFSIZ], ttyspec[BUFSIZ];
 319         struct stat st;
 320
 321         snprintf(ttyspec, sizeof(ttyspec), "/dev/%s", tty);
 322
 323         /*
 324         ** The mask depends on whether we are checking for
 325         ** write permission based on `biff' or `mesg'.
 326         */
 327         mask = biff ? S_IEXEC : (S_IWRITE >> 3);
 328         if (stat(ttyspec, &st) == NOTOK || (st.st_mode & mask) == 0)
 329                 return;
 330
 331         if (!setjmp(myctx)) {
 332                 SIGNAL(SIGALRM, alrmser);
 333                 alarm(2);
 334                 td = open(ttyspec, O_WRONLY);
 335                 alarm(0);
 336                 if (td == NOTOK)
 337                         return;
 338         } else {
 339                 alarm(0);
 340                 return;
 341         }
 342
 343         lseek(md, (off_t) 0, SEEK_SET);
 344
 345         while ((i = read(md, buffer, sizeof(buffer))) > 0)
 346                 if (write(td, buffer, i) != i)
 347                         break;
 348
 349         close(td);
 350 }