NetBSD-5.0.2/dist/dhcp/common/socket.c
/* socket.c
BSD socket interface code... */
/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1995-2003 by Internet Software Consortium
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Internet Systems Consortium, Inc.
* 950 Charter Street
* Redwood City, CA 94063
* <info@isc.org>
* http://www.isc.org/
*
* This software has been written for Internet Systems Consortium
* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
* To learn more about Internet Systems Consortium, see
* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
* ``http://www.nominum.com''.
*/
/* SO_BINDTODEVICE support added by Elliot Poger (poger@leland.stanford.edu).
* This sockopt allows a socket to be bound to a particular interface,
* thus enabling the use of DHCPD on a multihomed host.
* If SO_BINDTODEVICE is defined in your system header files, the use of
* this sockopt will be automatically enabled.
* I have implemented it under Linux; other systems should be doable also.
*/
#ifndef lint
static char copyright[] =
"$Id: socket.c,v 1.7 2005/08/11 17:13:21 drochner Exp $ Copyright (c) 2004 Internet Systems Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
#ifdef USE_SOCKET_FALLBACK
# if !defined (USE_SOCKET_SEND)
# define if_register_send if_register_fallback
# define send_packet send_fallback
# define if_reinitialize_send if_reinitialize_fallback
# endif
#endif
#if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_FALLBACK)
#if 0
#ifndef USE_SOCKET_RECEIVE
static int once = 0;
#endif
#endif
#endif
/* Reinitializes the specified interface after an address change. This
is not required for packet-filter APIs. */
#if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_FALLBACK)
void if_reinitialize_send (info)
struct interface_info *info;
{
#if 0
#ifndef USE_SOCKET_RECEIVE
once = 0;
close (info -> wfdesc);
#endif
if_register_send (info);
#endif
}
#endif
#ifdef USE_SOCKET_RECEIVE
void if_reinitialize_receive (info)
struct interface_info *info;
{
#if 0
once = 0;
close (info -> rfdesc);
if_register_receive (info);
#endif
}
#endif
#if defined (USE_SOCKET_SEND) || \
defined (USE_SOCKET_RECEIVE) || \
defined (USE_SOCKET_FALLBACK)
/* Generic interface registration routine... */
int if_register_socket (info)
struct interface_info *info;
{
struct sockaddr_in name;
int sock;
int flag;
#ifndef SMALL
char *buf;
char *policy = "out bypass";
#endif
#if !defined (HAVE_SO_BINDTODEVICE) && !defined (USE_FALLBACK)
/* Make sure only one interface is registered. */
if (once)
log_fatal ("The standard socket API can only support %s",
"hosts with a single network interface.");
once = 1;
#endif
memset (&name, 0, sizeof (name));
/* Set up the address we're going to bind to. */
name.sin_family = AF_INET;
name.sin_port = local_port;
name.sin_addr = local_address;
/* Make a socket... */
if ((sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
log_fatal ("Can't create dhcp socket: %m");
/* Set the REUSEADDR option so that we don't fail to start if
we're being restarted. */
flag = 1;
if (setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
(char *)&flag, sizeof flag) < 0)
log_fatal ("Can't set SO_REUSEADDR option on dhcp socket: %m");
#ifndef SMALL
/* Set a per-socket IPsec policy to prevent encryption. */
buf = ipsec_set_policy(policy, strlen(policy));
if (setsockopt (sock, IPPROTO_IP, IP_IPSEC_POLICY, buf,
ipsec_get_policylen(buf)) < 0 && errno != ENOPROTOOPT)
log_fatal ("Can't set IPsec policy on dhcp socket: %m");
free (buf);
#endif
/* Set the BROADCAST option so that we can broadcast DHCP responses.
We shouldn't do this for fallback devices, and we can detect that
a device is a fallback because it has no ifp structure. */
if (info -> ifp &&
(setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
(char *)&flag, sizeof flag) < 0))
log_fatal ("Can't set SO_BROADCAST option on dhcp socket: %m");
/* Bind the socket to this interface's IP address. */
if (bind (sock, (struct sockaddr *)&name, sizeof name) < 0) {
log_error ("Can't bind to dhcp address: %m");
log_error ("Please make sure there is no other dhcp server");
log_error ("running and that there's no entry for dhcp or");
log_error ("bootp in /etc/inetd.conf. Also make sure you");
log_error ("are not running HP JetAdmin software, which");
log_fatal ("includes a bootp server.");
}
#if defined (HAVE_SO_BINDTODEVICE)
/* Bind this socket to this interface. */
if (info -> ifp &&
setsockopt (sock, SOL_SOCKET, SO_BINDTODEVICE,
(char *)(info -> ifp), sizeof *(info -> ifp)) < 0) {
log_fatal ("setsockopt: SO_BINDTODEVICE: %m");
}
#endif
return sock;
}
#endif /* USE_SOCKET_SEND || USE_SOCKET_RECEIVE || USE_SOCKET_FALLBACK */
#if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_FALLBACK)
void if_register_send (info)
struct interface_info *info;
{
#ifndef USE_SOCKET_RECEIVE
info -> wfdesc = if_register_socket (info);
#if defined (USE_SOCKET_FALLBACK)
/* Fallback only registers for send, but may need to receive as
well. */
info -> rfdesc = info -> wfdesc;
#endif
#else
info -> wfdesc = info -> rfdesc;
#endif
if (!quiet_interface_discovery)
log_info ("Sending on Socket/%s%s%s",
info -> name,
(info -> shared_network ? "/" : ""),
(info -> shared_network ?
info -> shared_network -> name : ""));
}
#if defined (USE_SOCKET_SEND)
void if_deregister_send (info)
struct interface_info *info;
{
#ifndef USE_SOCKET_RECEIVE
close (info -> wfdesc);
#endif
info -> wfdesc = -1;
if (!quiet_interface_discovery)
log_info ("Disabling output on Socket/%s%s%s",
info -> name,
(info -> shared_network ? "/" : ""),
(info -> shared_network ?
info -> shared_network -> name : ""));
}
#endif /* USE_SOCKET_SEND */
#endif /* USE_SOCKET_SEND || USE_SOCKET_FALLBACK */
#ifdef USE_SOCKET_RECEIVE
void if_register_receive (info)
struct interface_info *info;
{
/* If we're using the socket API for sending and receiving,
we don't need to register this interface twice. */
info -> rfdesc = if_register_socket (info);
if (!quiet_interface_discovery)
log_info ("Listening on Socket/%s%s%s",
info -> name,
(info -> shared_network ? "/" : ""),
(info -> shared_network ?
info -> shared_network -> name : ""));
}
void if_deregister_receive (info)
struct interface_info *info;
{
close (info -> rfdesc);
info -> rfdesc = -1;
if (!quiet_interface_discovery)
log_info ("Disabling input on Socket/%s%s%s",
info -> name,
(info -> shared_network ? "/" : ""),
(info -> shared_network ?
info -> shared_network -> name : ""));
}
#endif /* USE_SOCKET_RECEIVE */
#if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_FALLBACK)
ssize_t send_packet (interface, packet, raw, len, from, to, hto)
struct interface_info *interface;
struct packet *packet;
struct dhcp_packet *raw;
size_t len;
struct in_addr from;
struct sockaddr_in *to;
struct hardware *hto;
{
int result;
#ifdef IGNORE_HOSTUNREACH
int retry = 0;
do {
#endif
result = sendto (interface -> wfdesc, (char *)raw, len, 0,
(struct sockaddr *)to, sizeof *to);
#ifdef IGNORE_HOSTUNREACH
} while (to -> sin_addr.s_addr == htonl (INADDR_BROADCAST) &&
result < 0 &&
(errno == EHOSTUNREACH ||
errno == ECONNREFUSED) &&
retry++ < 10);
#endif
if (result < 0) {
log_error ("send_packet: %m");
if (errno == ENETUNREACH)
log_error ("send_packet: please consult README file%s",
" regarding broadcast address.");
}
return result;
}
#endif /* USE_SOCKET_SEND || USE_SOCKET_FALLBACK */
#ifdef USE_SOCKET_RECEIVE
ssize_t receive_packet (interface, buf, len, from, hfrom)
struct interface_info *interface;
unsigned char *buf;
size_t len;
struct sockaddr_in *from;
struct hardware *hfrom;
{
SOCKLEN_T flen = sizeof *from;
int result;
#ifdef IGNORE_HOSTUNREACH
int retry = 0;
do {
#endif
result = recvfrom (interface -> rfdesc, (char *)buf, len, 0,
(struct sockaddr *)from, &flen);
#ifdef IGNORE_HOSTUNREACH
} while (result < 0 &&
(errno == EHOSTUNREACH ||
errno == ECONNREFUSED) &&
retry++ < 10);
#endif
return result;
}
#endif /* USE_SOCKET_RECEIVE */
#if defined (USE_SOCKET_FALLBACK)
/* This just reads in a packet and silently discards it. */
isc_result_t fallback_discard (object)
omapi_object_t *object;
{
char buf [1540];
struct sockaddr_in from;
SOCKLEN_T flen = sizeof from;
int status;
struct interface_info *interface;
if (object -> type != dhcp_type_interface)
return ISC_R_INVALIDARG;
interface = (struct interface_info *)object;
status = recvfrom (interface -> wfdesc, buf, sizeof buf, 0,
(struct sockaddr *)&from, &flen);
#if defined (DEBUG)
/* Only report fallback discard errors if we're debugging. */
if (status < 0) {
log_error ("fallback_discard: %m");
return ISC_R_UNEXPECTED;
}
#endif
return ISC_R_SUCCESS;
}
#endif /* USE_SOCKET_FALLBACK */
#if defined (USE_SOCKET_SEND)
int can_unicast_without_arp (ip)
struct interface_info *ip;
{
return 0;
}
int can_receive_unicast_unconfigured (ip)
struct interface_info *ip;
{
#if defined (SOCKET_CAN_RECEIVE_UNICAST_UNCONFIGURED)
return 1;
#else
return 0;
#endif
}
int supports_multiple_interfaces (ip)
struct interface_info *ip;
{
#if defined (SO_BINDTODEVICE)
return 1;
#else
return 0;
#endif
}
/* If we have SO_BINDTODEVICE, set up a fallback interface; otherwise,
do not. */
void maybe_setup_fallback ()
{
#if defined (USE_SOCKET_FALLBACK)
isc_result_t status;
struct interface_info *fbi = (struct interface_info *)0;
if (setup_fallback (&fbi, MDL)) {
fbi -> wfdesc = if_register_socket (fbi);
fbi -> rfdesc = fbi -> wfdesc;
log_info ("Sending on Socket/%s%s%s",
fbi -> name,
(fbi -> shared_network ? "/" : ""),
(fbi -> shared_network ?
fbi -> shared_network -> name : ""));
status = omapi_register_io_object ((omapi_object_t *)fbi,
if_readsocket, 0,
fallback_discard, 0, 0);
if (status != ISC_R_SUCCESS)
log_fatal ("Can't register I/O handle for %s: %s",
fbi -> name, isc_result_totext (status));
interface_dereference (&fbi, MDL);
}
#endif
}
#endif /* USE_SOCKET_SEND */