int
main(int argc, char *argv[])
{
int ch, login;
if ((euid = geteuid()) != 0)
warnx("need root permissions to function properly, check setuid bit");
if (seteuid(getuid()) < 0)
err(1, "seteuid");
if ((pwd = getpwuid(getuid())) == NULL)
errx(1, "unknown user");
login = 0;
while ((ch = getopt(argc, argv, "-l")) != -1) {
switch (ch) {
case '-': /* Obsolescent */
case 'l':
login = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
switch (argc) {
case 0:
restoregrps();
break;
case 1:
addgroup(*argv);
break;
default:
usage();
}
if (seteuid(euid) < 0)
err(1, "seteuid");
if (setuid(getuid()) < 0)
err(1, "setuid");
if (login)
loginshell();
else
doshell();
/*NOTREACHED*/
exit(1);
}
/*
The 'channel_exec' function executes new process.
If terminal is requsted, than users shell is executed,
if exec is requested, than command 'cmd' is executed.
Process is executed under appropriate users UID.
*/
int channel_exec(const char *cmd) {
char *run[4];
char *shell;
char *name;
int fd[3];
char ln[32];
if (channel.maxpacket == 0) bug_proto();
if (channel.pid != 0 ) bug_proto();
if (channel.flagterminal) {
channel.pid = channel_forkpty(fd, channel.master, channel.slave);
if (channel.pid > 0) {
name = ptsname(fd[0]);
if (!name) bug();
if (!str_copyn(channel.termname, sizeof channel.termname, name)) bug_nomem();
}
}
else {
channel.pid = channel_fork(fd);
}
if (channel.pid == -1) return 0;
if (channel.pid == 0) {
logsys_login(channel.user, channel.remoteip, 0, 0);
if (!channel_droppriv(channel.user, &shell)) _exit(111);
if (cmd) {
run[0] = shell;
run[1] = (char *)"-c";
run[2] = (char *)cmd;
run[3] = 0;
}
else {
if (!loginshell(ln, sizeof ln, shell)) bug();
run[0] = ln;
run[1] = 0;
}
signal(SIGPIPE, SIG_DFL);
newenv_exec(shell, run);
_exit(111);
}
channel.fd0 = fd[0];
channel.fd1 = fd[1];
channel.fd2 = fd[2];
channel.len0 = 0;
newenv_purge();
if (channel.flagterminal && channel.pid > 0) channel_ptyresize(channel.a, channel.b, channel.x, channel.y);
return 1;
}
