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/*
a simple TCP connector
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include "config.h"
#include "stty.h"
#define PORT 8500
#define BUFF_SIZE 4096
extern int errno;
#define max(x,y) ((x) > (y) ? (x) : (y))
void errorf (char *fmt, ...)
{
va_list args;
va_start (args, fmt);
vfprintf (stderr, fmt, args);
exit (1);
}
int main (int argc, char **argv)
{
fd_set readset;
struct sockaddr_in my_addr;
struct hostent *host;
int sock, n, fd, fdmax, port = PORT, quit = 0, echar = 0;
char buff[BUFF_SIZE], *device = NULL, *s;
for (n = 1; argv[n] && *argv[n] == '-'; n++)
switch (argv[n][1])
{
case 'e' :
echar = argv[n][2] ? argv[n][2] : 28;
break;
case 'd' :
device = argv[n][2] || n + 2 >= argc || *argv[n + 1] == '-' ? argv[n] + 2 : argv[++n];
break;
case 'p' :
port = atoi (argv[n][2] || n + 2 >= argc || *argv[n + 1] == '-' ? argv[n] + 2 : argv[++n]);
break;
case 'h' :
errorf ("Usage: tcpconn [-d[pty]] [-p port] [-e[char]] hostname[:port]\n");
}
if (!argv[n])
errorf ("too few arguments\n");
if ((s = strtok(argv[n], ":")) == NULL)
errorf ("invalid hostname\n");
if ((host = gethostbyname(s)) == NULL)
errorf ("can't resolve hostname %s\n", s);
if ((s = strtok(NULL, ":")) != NULL)
port = atoi(s);
if (!port)
port = PORT;
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
errorf ("can't create client socket (%s)\n", strerror(errno));
bzero (&my_addr, sizeof(my_addr));
my_addr.sin_family = AF_INET;
my_addr.sin_addr = *(struct in_addr *) host->h_addr_list[0];
my_addr.sin_port = htons(port);
if (connect(sock, (struct sockaddr *) &my_addr, sizeof(my_addr)) < 0)
errorf ("can't connect to server (%s)\n", strerror(errno));
if (device)
{
if (!*device)
{
/* allocate a pty (derived from screen's pty.c) */
#ifdef BSD
char pty_name[] = "/dev/pty??", tty_name[] = "/dev/tty??", *p, *t, *l, *d;
uid_t euid = geteuid ();
p = strchr (pty_name, '?');
t = strchr (tty_name, '?');
for (l = "qpr"; (p[0] = *l) != '\0'; l++)
for (d = "0123456789abcdef"; (p[1] = *d) != '\0'; d++)
{
if ((fd = open (pty_name, O_RDWR | O_NOCTTY)) < 0)
continue;
t[0] = *l;
t[1] = *d;
if (euid && access (tty_name, R_OK | W_OK))
{
close (fd);
continue;
}
s = tty_name;
goto pty_allocated;
}
#else /* not BSD */
char *ptsname (int);
int grantpt (int), unlockpt (int);
if (!((fd = open ("/dev/ptmx", O_RDWR | O_NOCTTY)) < 0
|| (s = ptsname (fd)) == NULL
|| grantpt (fd) || unlockpt (fd)))
goto pty_allocated;
#endif /* BSD */
errorf ("can't allocate pty (%s)\n", strerror (errno));
pty_allocated:
puts (s);
chdir ("/");
switch (fork ())
{
case -1:
errorf ("can't fork (%s)\n", strerror (errno));
case 0:
break;
default:
exit (0);
}
}
else if ((fd = open(device, O_RDWR | O_NOCTTY)) < 0)
errorf ("can't open device %s (%s)\n", device, strerror(errno));
dup2 (fd, STDIN_FILENO);
dup2 (fd, STDOUT_FILENO);
}
else if (isatty(STDIN_FILENO))
{
stty_initstore ();
stty_raw (STDIN_FILENO);
atexit (stty_orig);
}
fdmax = max(STDIN_FILENO, sock);
while (!quit)
{
FD_ZERO (&readset);
FD_SET (STDIN_FILENO, &readset);
FD_SET (sock, &readset);
if (select(fdmax + 1, &readset, NULL, NULL, NULL) < 0)
errorf ("select failed (%s)\n", strerror(errno));
if (FD_ISSET(STDIN_FILENO, &readset))
{
if ((n = read(STDIN_FILENO, buff, BUFF_SIZE)) <= 0)
quit = 1;
else if (n == 1 && echar && *buff == echar)
quit = 1;
else
write (sock, buff, n);
}
if (FD_ISSET(sock, &readset))
{
if ((n = read(sock, buff, BUFF_SIZE)) <= 0)
quit = 1;
else
write (STDOUT_FILENO, buff, n);
}
}
close (sock);
printf ("\r\n");
return (0);
}
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