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