1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)announce.c	5.1 (Berkeley) 6/6/85";
   9: #endif not lint
  10: 
  11: #include "ctl.h"
  12: 
  13: #include <sys/stat.h>
  14: #include <sgtty.h>
  15: #include <sys/ioctl.h>
  16: #include <sys/time.h>
  17: #include <stdio.h>
  18: #include <sys/wait.h>
  19: #include <errno.h>
  20: 
  21: char *sprintf();
  22: 
  23: extern int errno;
  24: extern char hostname[];
  25: int nofork = 0;     /* to be set from the debugger */
  26: 
  27: /*
  28:  * Because the tty driver insists on attaching a terminal-less
  29:  * process to any terminal that it writes on, we must fork a child
  30:  * to protect ourselves
  31:  */
  32: 
  33: announce(request, remote_machine)
  34:     CTL_MSG *request;
  35:     char *remote_machine;
  36: {
  37:     int pid, val, status;
  38: 
  39:     if (nofork)
  40:         return(announce_proc(request, remote_machine));
  41:     if (pid = fork()) {
  42:         /* we are the parent, so wait for the child */
  43:         if (pid == -1)      /* the fork failed */
  44:             return(FAILED);
  45:         do {
  46:             val = wait(&status);
  47:             if (val == -1) {
  48:                 if (errno == EINTR)
  49:                     continue;
  50:                 /* shouldn't happen */
  51:                 perror("wait");
  52:                 return (FAILED);
  53:             }
  54:         } while (val != pid);
  55:         if (status&0377 > 0)    /* we were killed by some signal */
  56:             return (FAILED);
  57:         /* Get the second byte, this is the exit/return code */
  58:         return ((status >> 8) & 0377);
  59:     }
  60:     /* we are the child, go and do it */
  61:     _exit(announce_proc(request, remote_machine));
  62: }
  63: 
  64: /*
  65:  * See if the user is accepting messages. If so, announce that
  66:  * a talk is requested.
  67:  */
  68: announce_proc(request, remote_machine)
  69:     CTL_MSG *request;
  70:     char *remote_machine;
  71: {
  72:     int pid, status;
  73:     char full_tty[32];
  74:     FILE *tf;
  75:     struct stat stbuf;
  76: 
  77:     (void) sprintf(full_tty, "/dev/%s", request->r_tty);
  78:     if (access(full_tty, 0) != 0)
  79:         return (FAILED);
  80:     if ((tf = fopen(full_tty, "w")) == NULL)
  81:         return (PERMISSION_DENIED);
  82:     /*
  83: 	 * Open gratuitously attaches the talkd to
  84: 	 * any tty it opens, so disconnect us from the
  85: 	 * tty before we catch a signal
  86: 	 */
  87:     ioctl(fileno(tf), TIOCNOTTY, (struct sgttyb *) 0);
  88:     if (fstat(fileno(tf), &stbuf) < 0)
  89:         return (PERMISSION_DENIED);
  90:     if ((stbuf.st_mode&020) == 0)
  91:         return (PERMISSION_DENIED);
  92:     print_mesg(tf, request, remote_machine);
  93:     fclose(tf);
  94:     return (SUCCESS);
  95: }
  96: 
  97: #define max(a,b) ( (a) > (b) ? (a) : (b) )
  98: #define N_LINES 5
  99: #define N_CHARS 120
 100: 
 101: /*
 102:  * Build a block of characters containing the message.
 103:  * It is sent blank filled and in a single block to
 104:  * try to keep the message in one piece if the recipient
 105:  * in in vi at the time
 106:  */
 107: print_mesg(tf, request, remote_machine)
 108:     FILE *tf;
 109:     CTL_MSG *request;
 110:     char *remote_machine;
 111: {
 112:     struct timeval clock;
 113:     struct timezone zone;
 114:     struct tm *localtime();
 115:     struct tm *localclock;
 116:     char line_buf[N_LINES][N_CHARS];
 117:     int sizes[N_LINES];
 118:     char big_buf[N_LINES*N_CHARS];
 119:     char *bptr, *lptr;
 120:     int i, j, max_size;
 121: 
 122:     i = 0;
 123:     max_size = 0;
 124:     gettimeofday(&clock, &zone);
 125:     localclock = localtime( &clock.tv_sec );
 126:     sprintf(line_buf[i], " ");
 127:     sizes[i] = strlen(line_buf[i]);
 128:     max_size = max(max_size, sizes[i]);
 129:     i++;
 130:     sprintf(line_buf[i], "Message from Talk_Daemon@%s at %d:%02d ...",
 131:     hostname, localclock->tm_hour , localclock->tm_min );
 132:     sizes[i] = strlen(line_buf[i]);
 133:     max_size = max(max_size, sizes[i]);
 134:     i++;
 135:     sprintf(line_buf[i], "talk: connection requested by %s@%s.",
 136:         request->l_name, remote_machine);
 137:     sizes[i] = strlen(line_buf[i]);
 138:     max_size = max(max_size, sizes[i]);
 139:     i++;
 140:     sprintf(line_buf[i], "talk: respond with:  /usr/old/talk %s@%s",
 141:         request->l_name, remote_machine);
 142:     sizes[i] = strlen(line_buf[i]);
 143:     max_size = max(max_size, sizes[i]);
 144:     i++;
 145:     sprintf(line_buf[i], " ");
 146:     sizes[i] = strlen(line_buf[i]);
 147:     max_size = max(max_size, sizes[i]);
 148:     i++;
 149:     bptr = big_buf;
 150:     *(bptr++) = ''; /* send something to wake them up */
 151:     *(bptr++) = '\r';   /* add a \r in case of raw mode */
 152:     *(bptr++) = '\n';
 153:     for (i = 0; i < N_LINES; i++) {
 154:         /* copy the line into the big buffer */
 155:         lptr = line_buf[i];
 156:         while (*lptr != '\0')
 157:             *(bptr++) = *(lptr++);
 158:         /* pad out the rest of the lines with blanks */
 159:         for (j = sizes[i]; j < max_size + 2; j++)
 160:             *(bptr++) = ' ';
 161:         *(bptr++) = '\r';   /* add a \r in case of raw mode */
 162:         *(bptr++) = '\n';
 163:     }
 164:     *bptr = '\0';
 165:     fprintf(tf, big_buf);
 166:     fflush(tf);
 167:     ioctl(fileno(tf), TIOCNOTTY, (struct sgttyb *) 0);
 168: }

Defined functions

announce defined in line 33; used 2 times
announce_proc defined in line 68; used 2 times
print_mesg defined in line 107; used 1 times
  • in line 92

Defined variables

nofork defined in line 25; used 1 times
  • in line 39
sccsid defined in line 8; never used

Defined macros

N_CHARS defined in line 99; used 2 times
N_LINES defined in line 98; used 4 times
max defined in line 97; used 5 times
Last modified: 1986-04-26
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