shadow/lib/nscd.c

/* Copyright (c) 1999 SuSE GmbH Nuerenberg, Germany
   Author: Thorsten Kukuk <kukuk@suse.de> */

#include <assert.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>

/* Version number of the daemon interface */
#define NSCD_VERSION 2
/* Path for the Unix domain socket.  */
#define _PATH_NSCDSOCKET "/var/run/nscd/socket"
#define _PATH_NSCDSOCKET_OLD "/var/run/.nscd_socket"

/* Available services.  */
typedef enum {
	GETPWBYNAME,
	GETPWBYUID,
	GETGRBYNAME,
	GETGRBYGID,
	GETHOSTBYNAME,
	GETHOSTBYNAMEv6,
	GETHOSTBYADDR,
	GETHOSTBYADDRv6,
	LASTDBREQ = GETHOSTBYADDRv6,
	SHUTDOWN,		/* Shut the server down.  */
	GETSTAT,		/* Get the server statistic.  */
	INVALIDATE,		/* Invalidate one special cache.  */
	LASTREQ
} request_type;

/* Header common to all requests */
typedef struct {
	int version;		/* Version number of the daemon interface.  */
	request_type type;	/* Service requested.  */
#if defined(__alpha__)
	int64_t key_len;	/* Key length is 64bit on Alpha.  */
#else
	int32_t key_len;	/* Key length, 32bit on most plattforms.  */
#endif
} request_header;

/* Create a socket connected to a name.  */
static int nscd_open_socket (void)
{
	struct sockaddr_un addr;
	int sock;

	sock = socket (PF_UNIX, SOCK_STREAM, 0);
	if (sock < 0)
		return -1;

	addr.sun_family = AF_UNIX;
	assert (sizeof (addr.sun_path) >= sizeof (_PATH_NSCDSOCKET));
	strcpy (addr.sun_path, _PATH_NSCDSOCKET);
	if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0) {
		addr.sun_family = AF_UNIX;
		assert (sizeof (addr.sun_path) >=
			sizeof (_PATH_NSCDSOCKET_OLD));
		strcpy (addr.sun_path, _PATH_NSCDSOCKET_OLD);
		if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) <
		    0) {
			close (sock);
			return -1;
		}
	}

	return sock;
}

/*
 * nscd_flush_cache - flush specyfied service bufor in nscd cache
 */
int nscd_flush_cache (char *service)
{
	int sock = nscd_open_socket ();
	request_header req;
	struct iovec iov[2];
	ssize_t nbytes;

	if (sock == -1)
		return -1;

	req.version = NSCD_VERSION;
	req.type = INVALIDATE;
	req.key_len = strlen (service) + 1;

	iov[0].iov_base = &req;
	iov[0].iov_len = sizeof (req);
	iov[1].iov_base = service;
	iov[1].iov_len = req.key_len;

	nbytes = writev (sock, iov, 2);

	close (sock);
	return (nbytes != iov[0].iov_len + iov[1].iov_len ? (-1) : 0);
}