tty intercept works

1 files changed, 147 insertions, 0 deletions

diff --git a/ptyim.c b/ptyim.c
new file mode 100644
index 0000000..047bb25
--- /dev/null
+++ b/ptyim.c
@@ -0,0 +1,147 @@
+//required for posix_openpt to work
+#define _XOPEN_SOURCE 600
+#define _DEFAULT_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <termios.h>
+//#include <asm/termbits.h>
+#include <string.h>
+#include <signal.h>
+#include "im.h"
+int running = 1;
+//hook for when the pty child process dies
+void childhook(int a) {
+	running = 0;
+}
+int pty_slave = -1;
+//hook for SIGWINCH
+void winchhook(int a) {
+	struct winsize sz;
+	ioctl(STDIN_FILENO, TIOCGWINSZ, &sz);
+	ioctl(pty_slave, TIOCSWINSZ, &sz);
+
+}
+int main (int argc, char * argv[], char * envp[]) {
+	printf("%s: %d\n", "a", im_search("a",0,IM_TABLE_LEN));
+	printf("%s: %d\n", "bb", im_search("bb",0,IM_TABLE_LEN));
+	printf("%s: %d\n", "c", im_search("c",0,IM_TABLE_LEN));
+	printf("%s: %d\n", "ba", im_search("ba",0,IM_TABLE_LEN));
+	//creates the pty master
+	int pty_master = posix_openpt(O_RDWR);
+	if (pty_master < 0) {
+		fprintf(stderr, "errno: %d, failed to create pty master", errno);
+		return errno;
+	}
+	//makes it nonblocking
+	fcntl(pty_master, F_SETFL,O_NONBLOCK);
+	//make it raw
+	struct termios stdin_termio;
+	struct termios stdin_termio_bk;
+	tcgetattr(STDIN_FILENO,&stdin_termio);
+	tcgetattr(STDIN_FILENO,&stdin_termio_bk);
+	cfmakeraw(&stdin_termio);
+	tcsetattr(STDIN_FILENO,TCSANOW,&stdin_termio);
+	//make it nonblocking
+	fcntl(STDIN_FILENO, F_SETFL,O_NONBLOCK);
+
+
+	if ( unlockpt(pty_master) <0) {
+		fprintf(stderr, "errno: %d, failed to unlock pty slave", errno);
+		return errno;
+	}
+	//gets slave path
+	char * pty_slave_fn = ptsname(pty_master);
+	printf("Slave name %s\n", pty_slave_fn);
+	//tries to open pty slave
+	pty_slave = open(pty_slave_fn, O_RDWR);
+	if (pty_slave < 0) {
+		fprintf(stderr, "errno: %d, failed to open pty slave '%s'",\
+			errno, pty_slave_fn);
+		return errno;
+	}
+	//make the pty slave the same line discipline stdin was
+	tcsetattr(pty_slave,TCSANOW,&stdin_termio_bk);
+	//syncs the window sizes for the first time
+	winchhook(0);
+	//forks for running bash
+	pid_t mypid = fork();
+	printf("forked w/ pid %d\n", mypid);
+	if (mypid == 0) {
+
+		//set self to be session leader
+		if (setsid() <0) {
+			fprintf(stderr, "failed to make new session\n");
+		}
+		//all the stand streams
+		freopen(pty_slave_fn, "r", stdin);
+		freopen(pty_slave_fn, "w", stdout);
+		freopen(pty_slave_fn, "w", stderr);
+		//must be a session leader to set the controlling terminal
+		if (ioctl(pty_slave, TIOCSCTTY, 0)) {
+			fprintf(stderr, "errno: %d, failed to set controlling tty\n", errno);
+		}
+
+
+		
+		/*
+		 *  Opens up the Shell now
+		 */
+		
+		//opens up the slave pty
+		//needs to fork
+		//then set its own process group
+		//need to set the terminal
+		//exec bash then
+		//gets the shell to use, order is
+		// argument 1, then $SHELL< then /bin/sh
+		char * shellpath = "/bin/sh";
+		if (argc >1) {
+			shellpath = argv[1];
+		} else if (getenv("SHELL") != NULL) {
+			shellpath = getenv("SHELL");
+		}
+		//gets the terminal environmental variabke, 32 should be enough
+		char env_term[32] = "TERM="; 
+		strcat(env_term, getenv("TERM"));
+		char env_home[32] = "HOME="; 
+		strcat(env_home, getenv("HOME"));
+		char * shell_envs[3] = {env_term,env_home, NULL};
+		char * shell_args[2] = {shellpath, NULL};
+		//if (execve(shellpath,shell_args, shell_envs) == -1) {
+		if (execve(shellpath,shell_args, envp) == -1) {
+			fprintf(stderr, "errno: %d, Failed to start shell '%s'\n", errno, shellpath);
+			return errno;
+		}
+		//should automatically close any file descriptors
+		_exit(0);
+	} else {
+		signal(SIGCHLD, childhook);
+		signal(SIGWINCH, winchhook);
+		char readbuffer[1] = {0};
+		int chars_read = 0;
+		//open
+		while (running) {
+			//just relay everything for now
+			//read uses file descriptors and is a system call
+			chars_read = read(pty_master,readbuffer,1);
+			if (chars_read >0) {
+				write(STDIN_FILENO,readbuffer,1);
+			}
+			//relays input from stdin
+			char input_buffer[IM_TABLE_ENTRY_LEN] = {0};
+
+			chars_read = read(STDIN_FILENO, readbuffer, 1);
+			if (chars_read > 0) {
+				write(pty_master,readbuffer,1);
+			}
+		}
+	}
+	close(pty_master);
+	tcsetattr(STDIN_FILENO,TCSANOW,&stdin_termio_bk);
+	//close(pty_slave);
+	return 0;
+}