NetBSD/usr.sbin/dhcp/common/icmp.c

229 lines
6.5 KiB
C

/* dhcp.c
ICMP Protocol engine - for sending out pings and receiving
responses. */
/*
* Copyright (c) 1996-2000 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 in cooperation with Vixie Enterprises and Nominum, Inc.
* To learn more about the Internet Software 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''.
*/
#ifndef lint
static char copyright[] =
"$Id: icmp.c,v 1.1.1.9 2000/07/08 20:40:20 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
#include "netinet/ip.h"
#include "netinet/ip_icmp.h"
struct icmp_state {
OMAPI_OBJECT_PREAMBLE;
int socket;
void (*icmp_handler) PROTO ((struct iaddr, u_int8_t *, int));
};
static struct icmp_state *icmp_state;
static omapi_object_type_t *dhcp_type_icmp;
/* Initialize the ICMP protocol. */
void icmp_startup (routep, handler)
int routep;
void (*handler) PROTO ((struct iaddr, u_int8_t *, int));
{
struct protoent *proto;
int protocol = 1;
struct sockaddr_in from;
int fd;
int state;
struct icmp_state *new;
omapi_object_t *h;
isc_result_t result;
/* Only initialize icmp once. */
if (dhcp_type_icmp)
log_fatal ("attempted to reinitialize icmp protocol");
result = omapi_object_type_register (&dhcp_type_icmp,
"icmp", 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, sizeof (struct icmp_state));
if (result != ISC_R_SUCCESS)
log_fatal ("Can't register icmp object type: %s",
isc_result_totext (result));
new = (struct icmp_state *)dmalloc (sizeof *new, MDL);
if (!new)
log_fatal ("Unable to allocate state for icmp protocol");
memset (new, 0, sizeof *new);
new -> refcnt = 1;
new -> type = dhcp_type_icmp;
new -> icmp_handler = handler;
/* Get the protocol number (should be 1). */
proto = getprotobyname ("icmp");
if (proto)
protocol = proto -> p_proto;
/* Get a raw socket for the ICMP protocol. */
new -> socket = socket (AF_INET, SOCK_RAW, protocol);
if (new -> socket < 0)
log_fatal ("unable to create icmp socket: %m");
#if defined (HAVE_SETFD)
if (fcntl (new -> socket, F_SETFD, 1) < 0)
log_error ("Can't set close-on-exec on icmp socket: %m");
#endif
/* Make sure it does routing... */
state = 0;
if (setsockopt (new -> socket, SOL_SOCKET, SO_DONTROUTE,
(char *)&state, sizeof state) < 0)
log_fatal ("Can't disable SO_DONTROUTE on ICMP socket: %m");
result = omapi_register_io_object ((omapi_object_t *)new,
icmp_readsocket, 0,
icmp_echoreply, 0, 0);
if (result != ISC_R_SUCCESS)
log_fatal ("Can't register icmp handle: %s",
isc_result_totext (result));
icmp_state = new;
}
int icmp_readsocket (h)
omapi_object_t *h;
{
struct icmp_state *state;
state = (struct icmp_state *)h;
return state -> socket;
}
int icmp_echorequest (addr)
struct iaddr *addr;
{
struct sockaddr_in to;
struct icmp icmp;
int status;
if (!icmp_state)
log_fatal ("ICMP protocol used before initialization.");
#ifdef HAVE_SA_LEN
to.sin_len = sizeof to;
#endif
to.sin_family = AF_INET;
to.sin_port = 0; /* unused. */
memcpy (&to.sin_addr, addr -> iabuf, sizeof to.sin_addr); /* XXX */
icmp.icmp_type = ICMP_ECHO;
icmp.icmp_code = 0;
icmp.icmp_cksum = 0;
icmp.icmp_seq = 0;
#ifdef PTRSIZE_64BIT
icmp.icmp_id = (((u_int32_t)(u_int64_t)addr) ^
(u_int32_t)(((u_int64_t)addr) >> 32));
#else
icmp.icmp_id = (u_int32_t)addr;
#endif
memset (&icmp.icmp_dun, 0, sizeof icmp.icmp_dun);
icmp.icmp_cksum = wrapsum (checksum ((unsigned char *)&icmp,
sizeof icmp, 0));
/* Send the ICMP packet... */
status = sendto (icmp_state -> socket, (char *)&icmp, sizeof icmp, 0,
(struct sockaddr *)&to, sizeof to);
if (status < 0)
log_error ("icmp_echorequest %s: %m", inet_ntoa(to.sin_addr));
if (status != sizeof icmp)
return 0;
return 1;
}
isc_result_t icmp_echoreply (h)
omapi_object_t *h;
{
struct icmp *icfrom;
struct ip *ip;
struct sockaddr_in from;
unsigned char icbuf [1500];
int status;
SOCKLEN_T sl;
int hlen, len;
struct iaddr ia;
struct icmp_state *state;
state = (struct icmp_state *)h;
sl = sizeof from;
status = recvfrom (state -> socket, (char *)icbuf, sizeof icbuf, 0,
(struct sockaddr *)&from, &sl);
if (status < 0) {
log_error ("icmp_echoreply: %m");
return ISC_R_UNEXPECTED;
}
/* Find the IP header length... */
ip = (struct ip *)icbuf;
hlen = IP_HL (ip);
/* Short packet? */
if (status < hlen + (sizeof *icfrom)) {
return ISC_R_SUCCESS;
}
len = status - hlen;
icfrom = (struct icmp *)(icbuf + hlen);
/* Silently discard ICMP packets that aren't echoreplies. */
if (icfrom -> icmp_type != ICMP_ECHOREPLY) {
return ISC_R_SUCCESS;
}
/* If we were given a second-stage handler, call it. */
if (state -> icmp_handler) {
memcpy (ia.iabuf, &from.sin_addr, sizeof from.sin_addr);
ia.len = sizeof from.sin_addr;
(*state -> icmp_handler) (ia, icbuf, len);
}
return ISC_R_SUCCESS;
}