#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h> 
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <pwd.h>

#ifndef __linux__
#include <login_cap.h>
#endif

#define PAM_SM_AUTH

#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <security/pam_mod_misc.h>

#define NOLOGIN "/etc/nologin"

PAM_EXTERN int 
pam_sm_authenticate( pam_handle_t *pamh, int flags, 
		int argc, const char * argv[] ) 
{
	struct passwd *pwd;
	struct stat st;
	char *mtmp = NULL;
	const char * user;
	int pam_err, fd; 
#ifndef __linux__ 
	login_cap_t *lc;
#endif 

	if( (pam_err = pam_get_user(pamh,&user, NULL)) != PAM_SUCCESS ||
			(user == NULL) ) {
		PAM_ERROR("Could not determine user");
		return (PAM_USER_UNKNOWN);
	}


#ifndef __linux__ 
	lc = login_getclass(NULL);
        nologin = login_getcapstr(lc, "nologin", nologin_def, nologin_def);
        login_close(lc);
        lc = NULL;

	fd = open(nologin, O_RDONLY, 0);
#else
	fd = open(NOLOGIN, O_RDONLY, 0);
#endif
	/* 
	 * LinuxPAM's nologin returns PAM_IGNORE when no 'nologin' file is
	 * present while freebsd's nologin returns PAM_SUCCESS. We'll go 
	 * with PAM_IGNORE
	 * */

	if (fd < 0 )
		return (PAM_IGNORE);

	pwd = getpwnam(user);
	if(pwd && pwd->pw_uid == 0 )
		pam_err = PAM_SUCCESS;
	else { 
		if ( ! pwd ) 
			pam_err = PAM_USER_UNKNOWN;
	 	else 
			pam_err = PAM_AUTH_ERR;
	}

	/* get contents of /etc/nologin */
	if (fstat(fd,&st) < 0) { 
		close(fd);
		free(mtmp);
		return (pam_err);
	}


	mtmp = malloc(st.st_size + 1);
	if (!mtmp) {
		PAM_ERROR("Out of memory");
		close(fd);
		free(mtmp);
		return (PAM_BUF_ERR);
	}

	if ( read(fd, mtmp, st.st_size) == st.st_size ) {
		mtmp[st.st_size] = '\0';
		PAM_ERROR("%s", mtmp);
	} else 
		pam_err = PAM_SYSTEM_ERR;

	close(fd);
	free (mtmp);

	return (pam_err);

}	

PAM_EXTERN int
pam_sm_setcred(pam_handle_t *pamh , int flags ,
		    int argc , const char *argv[])
{

	        return (PAM_SUCCESS);
}

PAM_MODULE_ENTRY("pam_nologin");