/* talk.c Copyright Michael Temari 08/01/1996 All Rights Reserved */#include <sys/types.h>#include <sys/stat.h>#include <stdio.h>#include <string.h>#include <unistd.h>#include <stdlib.h>#include <signal.h>#include <utmp.h>#include <termios.h>#include <net/gen/netdb.h>#include <net/hton.h>#include <net/gen/socket.h>#include <net/gen/in.h>#include <net/gen/inet.h>#include <net/gen/tcp.h>#include <net/gen/udp.h>#include "talk.h"#include "proto.h"#include "net.h"#include "screen.h"_PROTOTYPE(int main, (int argc, char *argv[]));_PROTOTYPE(void DoTalk, (void));int main(argc, argv)int argc;char *argv[];{char *p;struct hostent *hp;struct stat st;struct utmp utmp;int slot;FILE *fp;   if(argc < 2 || argc > 3) {   	fprintf(stderr, "Usage: talk user[@host] [tty]\n");   	return(-1);   }   /* get local host name */   if(gethostname(lhost, HOST_SIZE) < 0) {   	fprintf(stderr, "talk: Error getting local host name\n");   	return(-1);   }   /* get local user name and tty */   if((slot = ttyslot()) < 0) {   	fprintf(stderr, "talk: You are not on a terminal\n");   	return(-1);   }   if((fp = fopen(UTMP, "r")) == (FILE *)NULL) {   	fprintf(stderr, "talk: Could not open %s\n", UTMP);   	return(-1);   }   if(fseek(fp, (off_t) sizeof(utmp) * slot, SEEK_SET)) {   	fprintf(stderr, "talk: Could not seek %s\n", UTMP);   	fclose(fp);   	return(-1);   }   if(fread((char *)&utmp, sizeof(utmp), 1 , fp) != 1) {   	fprintf(stderr, "talk: Could not read %s\n", UTMP);   	fclose(fp);   	return(-1);   }   fclose(fp);   strncpy(luser, utmp.ut_user, USER_SIZE < sizeof(utmp.ut_user) ?   				USER_SIZE : sizeof(utmp.ut_user));   luser[USER_SIZE] = '\0';   /* get local tty */   if((p = ttyname(0)) == (char *)NULL) {   	fprintf(stderr, "talk: You are not on a terminal\n");   	return(-1);   }   strncpy(ltty, p+5, TTY_SIZE);   ltty[TTY_SIZE] = '\0';   /* check if local tty is going to be writable */   if(stat(p, &st) < 0) {   	perror("talk: Could not stat local tty");   	return(-1);   }   if((st.st_mode & S_IWGRP) == 0) {   	fprintf(stderr, "talk: Your terminal is not writable.  Use: mesg y\n");   	return(-1);   }   /* get remote user and host name */   if((p = strchr(argv[1], '@')) != (char *)NULL)   	*p++ = '\0';   else   	p = lhost;   strncpy(ruser, argv[1], USER_SIZE);   ruser[USER_SIZE] = '\0';   strncpy(rhost, p, HOST_SIZE);   rhost[HOST_SIZE] = '\0';   /* get remote tty */   if(argc > 2)   	strncpy(rtty, argv[2], TTY_SIZE);   else   	rtty[0] = '\0';   rtty[TTY_SIZE] = '\0';   if((hp = gethostbyname(rhost)) == (struct hostent *)NULL) {   	fprintf(stderr, "talk: Could not determine address of %s\n", rhost);   	return(-1);   }   memcpy((char *)&raddr, (char *)hp->h_addr, hp->h_length);   if(NetInit()) {   	fprintf(stderr, "talk: Error in NetInit\n");   	return(-1);   }   if(ScreenInit())   	return(-1);   if(!TalkInit())	DoTalk();   ScreenEnd();   return(0);}struct pdata {	int win;	int len;	char buffer[64];} pdata;void DoTalk(){int s;int s2;int kid;int pfd[2];int win;int len;struct termios termios;char lcc[3];char rcc[3];   ScreenMsg("");   ScreenWho(ruser, rhost);   /* Get and send edit characters */   s = tcgetattr(0, &termios);   if(s < 0) {   	perror("talk: tcgetattr");   	return;   }   lcc[0] = termios.c_cc[VERASE];   lcc[1] = termios.c_cc[VKILL];   lcc[2] = 0x17; /* Control - W */   s = write(tcp_fd, lcc, sizeof(lcc));   if(s != sizeof(lcc)) {   	ScreenMsg("Connection Closing due to error");   	return;   }   s = read(tcp_fd, rcc, sizeof(rcc));   if(s != sizeof(rcc)) {   	ScreenMsg("Connection Closing due to error");   	return;   }   ScreenEdit(lcc, rcc);   s = pipe(pfd);   if(s < 0) {   	ScreenMsg("Could not create pipes");   	return;   }   if((kid = fork()) < 0) {   	ScreenMsg("Could not fork");   	close(pfd[0]);   	close(pfd[1]);   	return;   }   if(kid == 0) {   	close(tcp_fd);   	close(pfd[1]);   	while(1) {   		s = read(pfd[0], &pdata, sizeof(pdata));   		if(s != sizeof(pdata)) {   			close(pfd[0]);   			exit(-1);   		}   		ScreenPut(pdata.buffer, pdata.len, pdata.win);   	}   }   close(pfd[0]);   if((kid = fork()) < 0) {   	ScreenMsg("Could not fork");   	close(pfd[1]);   	return;   }   if(kid == 0) {   	pdata.win = REMOTEWIN;   	while(!ScreenDone) {	   	s = read(tcp_fd, pdata.buffer, sizeof(pdata.buffer));   		if(s <= 0)   			break;   		pdata.len = s;		write(pfd[1], &pdata, sizeof(pdata));   	}   	close(pfd[1]);   	close(tcp_fd);	kill(getppid(), SIGINT);   	exit(-1);   }   pdata.win = LOCALWIN;   while(!ScreenDone) {	s = read(0, pdata.buffer, sizeof(pdata.buffer));	if(s <= 0)		break;	pdata.len = s;	write(pfd[1], &pdata, sizeof(pdata));	s2 = write(tcp_fd, pdata.buffer, s);	if(s2 != s)		break;   }   kill(kid, SIGINT);   close(pfd[1]);   close(tcp_fd);   return;}