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#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <time.h>
#include <alloca.h>
#include <grp.h>
#include <termios.h>
#include <sys/ioctl.h>
#include "str_defs.h"
#include "scan_defs.h"
#include "fmt_defs.h"
#define UUU "unable to "
void w(char *s) { write(2, s, str_len(s)); }
void e(char *x0, char *x1)
{ w("\nngetty-argv: "); w(x0); w(x1); w("\n"); sleep(1); }
/* sleep is needed to see the erros. see the option clear also */
unsigned int expand_string(char *tmp, char *string, char *user, char *tty) {
char *s=string, *pos=tmp, *exp, ch, found_one = 0;
for (; (ch=*s); s++) {
if (ch == '%') {
found_one = 1;
ch = s[1];
exp = user;
switch (ch) {
case 'T': exp = tty;
case 'U':
pos += (tmp) ? str_copy(pos, exp) : str_len(exp);
++s;
break;
case '%': /* %%U -> %U */
++s;
default:
ch = *s;
goto non_special;
}
} else {
non_special:
if (tmp) *pos = ch;
++pos;
}
}
if (found_one) {
if (tmp==0) return pos - tmp;
else *pos = 0;
}
return 0;
}
int main(int argc, char **argv, char **env) {
char **arg, **aa, *in, *s, *tmp, ch;
char *user, *tty, flagsetsid=0, flagdaemon=0, flagtty=0, *flagpid=0;
unsigned long n;
uid_t uid=0;
gid_t gid=0;
if (argc<2) {
usage:
e("usage:\n\tngetty-argv [Options][--]ArgvString [user [tty]]\n\n",
"\tArgvString:\t:/bin/sleep:hacker_sleep:39:other:args...\n"
"\tOptions:\t:-D:-S:-N:-C:-u123:-g59:-a45:-s3:-d/tmp:-r/var/tmp\n"
"\tOptions:\t:-e,HOME=/,TERM=linux:-p/var/run/ngetty.pid\n"
"\tExample:\t:-u106:-g506:-d/var/qmail:--:./bin/qmail-qread:queue\n");
return 100;
}
in = argv[1];
user =(argc>2) ? argv[2] : "";
tty =(argc>3) ? argv[3] : "";
ch = *in++; /* don't use '%' as split char */
if (ch == 0 || *in == 0 ||
(n=splitmem(0, in, ch)) < 2) goto usage;
arg = alloca((n+5) * sizeof(char *)); if (arg==0) _exit(111);
splitmem(arg, in, ch);
for (aa=arg; (s=*aa); ++aa) {
n = expand_string(0, s, user, tty);
if (n==0) continue;
tmp = alloca(n + 4); if (tmp==0) _exit(111);
*aa = tmp;
expand_string(tmp, s, user, tty);
}
for (aa=arg; (s=*aa); aa++) {
if (*s != '-') break;
s += 2;
switch (s[-1]) {
case 'e':
if (*s == 0) { env = 0; }
else {
ch = *s++;
n=splitmem(0,s,ch);
env=alloca((n+1) * sizeof(char*)); if (env==0) _exit(1);
splitmem(env,s,ch);
}
break;
case 'D': flagdaemon=1; break;
case 'S': flagsetsid=1; break;
case 'N': flagtty=1; break;
case 'C': flagtty=2; break;
case 'p': if (*s) flagpid=s; break;
case 'g': scan_ulong(s, &n); gid = n; break;
case 'u': scan_ulong(s, &n); uid = n; break;
case 'a': scan_ulong(s, &n); alarm(n); break;
case 's': scan_ulong(s, &n); sleep(n); break;
case 'd': if (chdir(s)) { e(s, ": chdir error"); return 100; } break;
case 'r': if (chroot(s)) { e(s, ": chroot error"); return 100; } break;
case '-': aa++; goto do_it;
default:
e(s-2, " : unknown option");
return 1;
}
}
do_it:
if (flagdaemon) {
int pid;
while ((pid=fork()) <0) sleep(1);
if (pid) _exit(0);
}
if (flagsetsid) setsid();
if (flagtty==1) ioctl(0, TIOCNOTTY, (void *)1);
if (flagtty==2) ioctl(0, TIOCSCTTY, (void *)1);
if (flagpid) {
int fd = open(flagpid, O_RDWR | O_TRUNC | O_CREAT, 0644);
if (fd>=0) {
char tmp[12];
n=fmt_ulong(tmp, getpid());
tmp[n] = '\n';
write(fd, tmp, n+1);
close(fd);
}
}
if (uid || gid) {
if (gid==0) gid = uid;
if (setgroups(1,&gid) ||
setgid(gid) ||
setuid(uid)) { e(UUU, "set uidgid"); return 100; }
}
s = *aa++;
if (s==0 || *aa==0) return 0;
if (aa[0][0] == 0) aa[0] = s;
execve(s, aa, env);
e(s, ": exec error");
return 127;
}
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