288 lines
8.3 KiB
C
288 lines
8.3 KiB
C
/* socket.c
|
|
|
|
BSD socket interface code... */
|
|
|
|
/*
|
|
* Copyright (c) 1995, 1996, 1997, 1998, 1999
|
|
* The Internet Software Consortium. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of The Internet Software Consortium nor the names
|
|
* of its contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
|
|
* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
|
|
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
|
|
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
|
|
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This software has been written for the Internet Software Consortium
|
|
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
|
|
* Enterprises. To learn more about the Internet Software Consortium,
|
|
* see ``http://www.vix.com/isc''. To learn more about Vixie
|
|
* Enterprises, see ``http://www.vix.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 1.26.2.10 1999/02/23 22:09:55 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium. All rights reserved.\n";
|
|
#endif /* not lint */
|
|
|
|
#include "dhcpd.h"
|
|
|
|
#ifdef USE_SOCKET_FALLBACK
|
|
# define USE_SOCKET_SEND
|
|
# define if_register_send if_register_fallback
|
|
# define send_packet send_fallback
|
|
# define if_reinitialize_send if_reinitialize_fallback
|
|
#endif
|
|
|
|
static int once = 0;
|
|
|
|
/* Reinitializes the specified interface after an address change. This
|
|
is not required for packet-filter APIs. */
|
|
|
|
#ifdef USE_SOCKET_SEND
|
|
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)
|
|
/* Generic interface registration routine... */
|
|
int if_register_socket (info)
|
|
struct interface_info *info;
|
|
{
|
|
struct sockaddr_in name;
|
|
int sock;
|
|
int flag;
|
|
|
|
#if !defined (HAVE_SO_BINDTODEVICE) && !defined (USE_FALLBACK)
|
|
/* Make sure only one interface is registered. */
|
|
if (once)
|
|
error ("The standard socket API can only support %s",
|
|
"hosts with a single network interface.");
|
|
once = 1;
|
|
#endif
|
|
|
|
/* Set up the address we're going to bind to. */
|
|
name.sin_family = AF_INET;
|
|
name.sin_port = local_port;
|
|
name.sin_addr.s_addr = INADDR_ANY;
|
|
memset (name.sin_zero, 0, sizeof (name.sin_zero));
|
|
|
|
/* Make a socket... */
|
|
if ((sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
|
|
error ("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)
|
|
error ("Can't set SO_REUSEADDR option on dhcp socket: %m");
|
|
|
|
/* Set the BROADCAST option so that we can broadcast DHCP responses. */
|
|
if (setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
|
|
(char *)&flag, sizeof flag) < 0)
|
|
error ("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)
|
|
error ("Can't bind to dhcp address: %m");
|
|
|
|
#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) {
|
|
error("setsockopt: SO_BINDTODEVICE: %m");
|
|
}
|
|
#endif
|
|
|
|
return sock;
|
|
}
|
|
#endif /* USE_SOCKET_SEND || USE_SOCKET_RECEIVE */
|
|
|
|
#ifdef USE_SOCKET_SEND
|
|
void if_register_send (info)
|
|
struct interface_info *info;
|
|
{
|
|
#ifndef USE_SOCKET_RECEIVE
|
|
info -> wfdesc = if_register_socket (info);
|
|
#else
|
|
info -> wfdesc = info -> rfdesc;
|
|
#endif
|
|
if (!quiet_interface_discovery)
|
|
note ("Sending on Socket/%s%s%s",
|
|
info -> name,
|
|
(info -> shared_network ? "/" : ""),
|
|
(info -> shared_network ?
|
|
info -> shared_network -> name : ""));
|
|
}
|
|
#endif /* USE_SOCKET_SEND */
|
|
|
|
#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)
|
|
note ("Listening on Socket/%s%s%s",
|
|
info -> name,
|
|
(info -> shared_network ? "/" : ""),
|
|
(info -> shared_network ?
|
|
info -> shared_network -> name : ""));
|
|
}
|
|
#endif /* USE_SOCKET_RECEIVE */
|
|
|
|
#ifdef USE_SOCKET_SEND
|
|
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) {
|
|
warn ("send_packet: %m");
|
|
if (errno == ENETUNREACH)
|
|
warn ("send_packet: please consult README file %s",
|
|
"regarding broadcast address.");
|
|
}
|
|
return result;
|
|
}
|
|
#endif /* USE_SOCKET_SEND */
|
|
|
|
#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;
|
|
{
|
|
int 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 */
|
|
|
|
#ifdef USE_SOCKET_SEND
|
|
/* This just reads in a packet and silently discards it. */
|
|
|
|
void fallback_discard (protocol)
|
|
struct protocol *protocol;
|
|
{
|
|
char buf [1540];
|
|
struct sockaddr_in from;
|
|
int flen = sizeof from;
|
|
int status;
|
|
struct interface_info *interface = protocol -> local;
|
|
|
|
status = recvfrom (interface -> wfdesc, buf, sizeof buf, 0,
|
|
(struct sockaddr *)&from, &flen);
|
|
if (status < 0)
|
|
warn ("fallback_discard: %m");
|
|
}
|
|
#endif /* USE_SOCKET_SEND */
|
|
|
|
#if defined (USE_SOCKET_SEND) && !defined (USE_SOCKET_FALLBACK)
|
|
int can_unicast_without_arp ()
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* If we have SO_BINDTODEVICE, set up a fallback interface; otherwise,
|
|
do not. */
|
|
|
|
void maybe_setup_fallback ()
|
|
{
|
|
#if defined (SO_BINDTODEVICE)
|
|
struct interface_info *fbi;
|
|
fbi = setup_fallback ();
|
|
if (fbi) {
|
|
fbi -> wfdesc = if_register_socket (fbi);
|
|
add_protocol ("fallback",
|
|
fbi -> wfdesc, fallback_discard, fbi);
|
|
}
|
|
#endif
|
|
}
|
|
#endif /* USE_SOCKET_SEND && !USE_SOCKET_FALLBACK */
|