/* S R I A L P O P (POP over serial lines) Author: Rudi van Houten Ac.Comp.Centr.Utrecht (Netherlands) With thanks to: Steve Dorner Scott Hannahs Mogen Trab Damsgaard see the file README for an introduction and hints for installation */ static char sccsid[]= "@(#)srialpop.c 1.2"; #define LOGOUTGRACE 3 /* this is the time to wait (seconds) after a logout command before actually breaking the connection */ #include #include #include #include #include #include #include #include #ifdef SYSV #define bcopy(a,b,c) memcpy(b,a,c) #include #else #include #endif #if __STDC__==1 #include #else #include #endif #define CRLF "\r\n" #define iBuflen 512 static char sBuf[iBuflen]; static short iValidPort[]= {25 /* SMTP */ ,105 /* PH server */ ,106 /* password server */ ,109 /* POP2 */ ,110 /* POP3 */ }; #define iValidPortsCount sizeof(iValidPort)/sizeof(short) #ifdef SYSV static struct termio sTermHold, sTermCurr; #else static struct sgttyb sTermHold, sTermCurr; #endif #if __STDC__==1 static void errorexit(char*, ... ); void main(void); # ifdef EXTRATTYFLAGS static void extrattyflags(void); # endif #endif #ifdef EXTRATTYFLAGS static void extrattyflags() { /* * here code can be placed to add/clear extra flags in * the tty discipline descriptions * here is an example that Scott Hannahs used on SGI */ sTermCurr.c_iflag |= (IXON | IXOFF); return; } /* void extrattyflags */ #endif #if __STDC__==1 static void errorexit(char *sFormat, ...) { #else static void errorexit(va_alist) va_dcl { char *sFormat; #endif va_list ap; fputs(CRLF,stderr); #if __STDC__==1 va_start(ap,sFormat); #else va_start(ap); sFormat= va_arg(ap,char*); #endif vfprintf(stderr,sFormat,ap); va_end(ap); fputs(CRLF,stderr); #ifdef SYSV ioctl(0,TCSETAF,&sTermHold); #else ioctl(0,TIOCSETP,&sTermHold); #endif sleep(1); exit(1); } /* errorexit */ void main() { int iSock, iPort, iChild; register int i, l; struct in_addr sInAddr; struct sockaddr_in sServer; struct hostent *psHost, *gethostbyname(), *gethostbyaddr(); char *psCommand, *psName, *psNumber; /* get stty structure sTermHold */ #ifdef SYSV ioctl(0,TCGETA,&sTermHold); #else ioctl(0,TIOCGETP,&sTermHold); #endif bcopy(&sTermHold,&sTermCurr,sizeof(sTermCurr)); /* and here prepare the line characteristics */ #ifdef SYSV sTermCurr.c_iflag &= ~(ICRNL | IXANY); sTermCurr.c_oflag &= ~OPOST; sTermCurr.c_lflag &= ~(ECHO | ICANON | ISIG ); sTermCurr.c_cc[VMIN] = 1; sTermCurr.c_cc[VTIME] = 0; #else sTermCurr.sg_flags &= ~(ECHO | CRMOD | XTABS); sTermCurr.sg_flags |= CBREAK; #endif #ifdef EXTRATTYFLAGS extrattyflags(); #endif /* set line characteristics to NOECHO, NOCRLF etc. */ #ifdef SYSV ioctl(0,TCSETAF,&sTermCurr); #else ioctl(0,TIOCSETP,&sTermCurr); #endif /* this is the main loop, it reads the telnet or exit commandline */ for (;;) { write(1,"%",1); l= 0; while(read(0,&sBuf[l],1) == 1 && sBuf[l] != '\n' && sBuf[l] != '\r') { write(1,&sBuf[l],1); if (++l >= iBuflen) errorexit("Too long commandline",0); } write(1,CRLF,2); if (sBuf[l] == '\n' || sBuf[l] == '\r') sBuf[l]= '\0'; else sBuf[++l]= '\0'; if (l == 0) continue; if (strcmp(sBuf,"logout") == 0 || strcmp(sBuf,"exit") == 0 || strcmp(sBuf,"quit") == 0 ) break; /* finished, logout now */ /* next loop splits the commandline in its constituents */ i= 0; psCommand= psName= psNumber= NULL; while (i < l && psNumber == NULL) { while (isspace(sBuf[i])) i++; if (i >= l) break; if (psCommand == NULL) psCommand= &sBuf[i]; /* command found */ else if (psName == NULL) psName= &sBuf[i]; /* argument 1 */ else psNumber= &sBuf[i]; /* argument 2 */ do { i++; } while (!isspace(sBuf[i]) && i < l); sBuf[i++]= '\0'; /* terminator after last argument */ } /* now we have a command (telnet) with two arguments (1=host 2=portnumber) */ if (strcmp(psCommand,"telnet")) errorexit("Sorry, don't know '%s'\n",psCommand); /* telnet is the only known command */ if (psName == NULL || psNumber == NULL) errorexit("Sorry, hostname or portnumber missing\n",0); /* and both host and port are required */ if (l= strlen(psNumber)) { for (i= 0; i < l; i++) if (!isdigit(psNumber[i])) errorexit("Portnumber (%s) not numeric\n",psNumber); iPort= atoi(psNumber); } else iPort= 0; /* check validity of portnumber */ for (i=0; iPort != iValidPort[i]; i++) if (i == iValidPortsCount) errorexit("Sorry, %d is not a valid port\n",iPort); /* (unsigned long)(-1) = 0xffffffff, returnvalue from inet_addr() if illegal address passed through. I assume then it is a domain name. Thanks to Edwin Kremer (edwin@cs.ruu.nl) for the trick */ if ((sInAddr.s_addr= inet_addr(psName)) == 0xffffffff) psHost= gethostbyname(psName); else psHost= gethostbyaddr((char*)&sInAddr,sizeof(struct in_addr),AF_INET); if (psHost == 0) errorexit("Cannot find server %s (host unknown)\n",psName); /* create socket */ if ((iSock= socket(AF_INET,SOCK_STREAM,0)) < 0) { perror("Cannot open IP socket"); exit(1); } /* fill socket structure .....*/ sServer.sin_family= AF_INET; bcopy(psHost->h_addr,&(sServer.sin_addr),psHost->h_length); sServer.sin_port= htons(iPort); /*........and connect */ if (connect(iSock,&sServer,sizeof(sServer)) < 0) { perror("connecting stream socket"); exit(1); } /* now fork a child to copy stdin to socket */ iChild= fork(); if (iChild < 0) { perror("Cannot fork"); exit(1); } if (iChild == 0) { /* the child copies stdin to the socket */ close(1); close(2); /* now close stdout and stderr */ while ((l= read(0,sBuf,iBuflen)) > 0) write(iSock,sBuf,l); close(0); exit(0); } /* if (iChild == 0) */ /* no else part, child does exit the parent copies the socket to stdout */ while ((l= read(iSock,sBuf,iBuflen)) > 0) write(1,sBuf,l); close(iSock); kill(iChild,SIGTERM); /* superfluous */ } /* main loop */ /* reset line characteristics */ #ifdef SYSV ioctl(0,TCSETAF,&sTermHold); #else ioctl(0,TIOCSETP,&sTermHold); #endif sleep(LOGOUTGRACE); /* wait to satisfy Mac's Hayes Modem Tool */ close(0); close(1); close(2); exit(0); } /* main */