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/*
* $Id$
*
* A central point for invoking getlogin(). Hopefully, this is a
* little harder to spoof than all the other versions that are out
* there.
*/
#include "pam_modutil_private.h"
#include <stdlib.h>
#include <unistd.h>
#include <utmp.h>
#define _PAMMODUTIL_GETLOGIN "_pammodutil_getlogin"
const char *
pam_modutil_getlogin(pam_handle_t *pamh)
{
int status;
const void *logname;
const void *void_curr_tty;
const char *curr_tty;
char *curr_user;
struct utmp *ut, line;
status = pam_get_data(pamh, _PAMMODUTIL_GETLOGIN, &logname);
if (status == PAM_SUCCESS) {
return logname;
}
status = pam_get_item(pamh, PAM_TTY, &void_curr_tty);
if ((status != PAM_SUCCESS) || (void_curr_tty == NULL))
curr_tty = ttyname(0);
else
curr_tty = (const char*)void_curr_tty;
if (curr_tty == NULL) {
return NULL;
}
if (curr_tty[0] == '/') { /* full path */
const char *t;
curr_tty++;
if ((t = strchr(curr_tty, '/')) != NULL) {
curr_tty = t + 1;
}
}
logname = NULL;
setutent();
strncpy(line.ut_line, curr_tty, sizeof(line.ut_line));
if ((ut = getutline(&line)) == NULL) {
goto clean_up_and_go_home;
}
curr_user = calloc(sizeof(line.ut_user)+1, 1);
if (curr_user == NULL) {
goto clean_up_and_go_home;
}
strncpy(curr_user, ut->ut_user, sizeof(ut->ut_user));
/* calloc already zeroed the memory */
status = pam_set_data(pamh, _PAMMODUTIL_GETLOGIN, curr_user,
pam_modutil_cleanup);
if (status != PAM_SUCCESS) {
free(curr_user);
goto clean_up_and_go_home;
}
logname = curr_user;
clean_up_and_go_home:
endutent();
return logname;
}
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