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