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/* author: klacke@hyber.org */
/* purpose, make us run under a different username */
/* as well as iface to some other idiotic syscalls */
/* FIXME replace this entirely with a proper */
/* posix interface */
#include <unistd.h>
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pwd.h>
#include <stdlib.h>
#include "erl_driver.h"
static ErlDrvData setuid_start(ErlDrvPort port, char *buf);
static void setuid_stop(ErlDrvData drv_data);
static ErlDrvEntry setuid_driver_entry;
/* buf is the name of the intented user */
static ErlDrvData setuid_start(ErlDrvPort port, char *buf)
{
char *t;
char xbuf[BUFSIZ];
struct passwd *pe;
if ((t = strchr(buf, ' ')) == NULL)
return (ErlDrvData) -1;
/* Rewind pw mapping */
setpwent();
t++;
switch (*t++) {
case 's': /* setuid */
while ((pe = getpwent())) {
if (strcmp(pe->pw_name , t) == 0) {
if ((setuid(pe->pw_uid) != 0) ||
(setreuid(pe->pw_uid, pe->pw_uid) != 0)) {
return (ErlDrvData) -1;
}
sprintf(xbuf, "ok %u", (unsigned)pe->pw_uid);
endpwent();
driver_output(port,xbuf, strlen(xbuf));
return (ErlDrvData) port;
}
}
endpwent();
break;
case 'n': {
int uid = atoi(t);
while ((pe = getpwent())) {
if (pe->pw_uid == uid) {
sprintf(xbuf, "ok %s", pe->pw_name);
endpwent();
driver_output(port,xbuf, strlen(xbuf));
return (ErlDrvData) port;
}
}
endpwent();
driver_output(port, "ok -", 4);
return (ErlDrvData) port;
}
case 'g': /* getuid */
sprintf(xbuf, "ok %u", (unsigned)getuid());
driver_output(port,xbuf, strlen(xbuf));
return (ErlDrvData) port;
case 'u':
while ((pe = getpwent())) {
if (strcmp(pe->pw_name , t) == 0) {
sprintf(xbuf, "ok %u", (unsigned)pe->pw_uid);
endpwent();
driver_output(port,xbuf, strlen(xbuf));
return (ErlDrvData) port;
}
}
endpwent();
break;
case 'h':
while ((pe = getpwent())) {
if (strcmp(pe->pw_name , t) == 0) {
sprintf(xbuf, "ok %s", pe->pw_dir);
endpwent();
driver_output(port,xbuf, strlen(xbuf));
return (ErlDrvData) port;
}
}
endpwent();
break;
}
// In any case return error(?) for non void function
return (ErlDrvData) -1;
}
static void setuid_stop(ErlDrvData drv_data)
{
}
/*
* Initialize and return a driver entry struct
*/
DRIVER_INIT(setuid_drv)
{
setuid_driver_entry.init = NULL; /* Not used */
setuid_driver_entry.start = setuid_start;
setuid_driver_entry.stop = setuid_stop;
setuid_driver_entry.output = NULL;
setuid_driver_entry.ready_input = NULL;
setuid_driver_entry.ready_output = NULL;
setuid_driver_entry.driver_name = "setuid_drv";
setuid_driver_entry.finish = NULL;
setuid_driver_entry.handle = NULL;
setuid_driver_entry.control = NULL;
setuid_driver_entry.timeout = NULL;
setuid_driver_entry.outputv = NULL;
setuid_driver_entry.ready_async = NULL;
setuid_driver_entry.flush = NULL;
setuid_driver_entry.call = NULL;
setuid_driver_entry.extended_marker = ERL_DRV_EXTENDED_MARKER;
setuid_driver_entry.major_version = ERL_DRV_EXTENDED_MAJOR_VERSION;
setuid_driver_entry.minor_version = ERL_DRV_EXTENDED_MINOR_VERSION;
setuid_driver_entry.driver_flags = 0;
setuid_driver_entry.handle2 = NULL;
setuid_driver_entry.process_exit = NULL;
setuid_driver_entry.stop_select = NULL;
return (ErlDrvEntry*) &setuid_driver_entry;
}
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