freebsd-dev/contrib/isc-dhcp/common/icmp.c
2002-02-19 11:04:34 +00:00

326 lines
8.9 KiB
C

/* dhcp.c
ICMP Protocol engine - for sending out pings and receiving
responses. */
/*
* Copyright (c) 1996-2001 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 1.30.2.3 2001/10/18 20:11:24 mellon Exp $ Copyright (c) 1996-2001 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 *icmp_state;
static omapi_object_type_t *dhcp_type_icmp;
static int no_icmp;
OMAPI_OBJECT_ALLOC (icmp_state, struct icmp_state, dhcp_type_icmp)
#if defined (TRACING)
trace_type_t *trace_icmp_input;
trace_type_t *trace_icmp_output;
#endif
/* 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),
0, RC_MISC);
if (result != ISC_R_SUCCESS)
log_fatal ("Can't register icmp object type: %s",
isc_result_totext (result));
icmp_state_allocate (&icmp_state, MDL);
icmp_state -> icmp_handler = handler;
#if defined (TRACING)
trace_icmp_input = trace_type_register ("icmp-input", (void *)0,
trace_icmp_input_input,
trace_icmp_input_stop, MDL);
trace_icmp_output = trace_type_register ("icmp-output", (void *)0,
trace_icmp_output_input,
trace_icmp_output_stop, MDL);
/* If we're playing back a trace file, don't create the socket
or set up the callback. */
if (!trace_playback ()) {
#endif
/* Get the protocol number (should be 1). */
proto = getprotobyname ("icmp");
if (proto)
protocol = proto -> p_proto;
/* Get a raw socket for the ICMP protocol. */
icmp_state -> socket = socket (AF_INET, SOCK_RAW, protocol);
if (icmp_state -> socket < 0) {
no_icmp = 1;
log_error ("unable to create icmp socket: %m");
return;
}
#if defined (HAVE_SETFD)
if (fcntl (icmp_state -> socket, F_SETFD, 1) < 0)
log_error ("Can't set close-on-exec on icmp: %m");
#endif
/* Make sure it does routing... */
state = 0;
if (setsockopt (icmp_state -> socket, SOL_SOCKET, SO_DONTROUTE,
(char *)&state, sizeof state) < 0)
log_fatal ("Can't disable SO_DONTROUTE on ICMP: %m");
result = (omapi_register_io_object
((omapi_object_t *)icmp_state,
icmp_readsocket, 0, icmp_echoreply, 0, 0));
if (result != ISC_R_SUCCESS)
log_fatal ("Can't register icmp handle: %s",
isc_result_totext (result));
#if defined (TRACING)
}
#endif
}
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 defined (TRACING)
trace_iov_t iov [2];
#endif
if (no_icmp)
return 1;
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));
#if defined (TRACING)
if (trace_playback ()) {
char *buf = (char *)0;
unsigned buflen = 0;
/* Consume the ICMP event. */
status = trace_get_packet (&trace_icmp_output, &buflen, &buf);
if (status != ISC_R_SUCCESS)
log_error ("icmp_echorequest: %s",
isc_result_totext (status));
if (buf)
dfree (buf, MDL);
} else {
if (trace_record ()) {
iov [0].buf = (char *)addr;
iov [0].len = sizeof *addr;
iov [1].buf = (char *)&icmp;
iov [1].len = sizeof icmp;
trace_write_packet_iov (trace_icmp_output,
2, iov, MDL);
}
#endif
/* 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;
#if defined (TRACING)
}
#endif
return 1;
}
isc_result_t icmp_echoreply (h)
omapi_object_t *h;
{
struct icmp *icfrom;
struct ip *ip;
struct sockaddr_in from;
u_int8_t icbuf [1500];
int status;
SOCKLEN_T sl;
int hlen, len;
struct iaddr ia;
struct icmp_state *state;
#if defined (TRACING)
trace_iov_t iov [2];
#endif
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;
#if defined (TRACING)
if (trace_record ()) {
ia.len = htonl(ia.len);
iov [0].buf = (char *)&ia;
iov [0].len = sizeof ia;
iov [1].buf = (char *)icbuf;
iov [1].len = len;
trace_write_packet_iov (trace_icmp_input, 2, iov, MDL);
ia.len = ntohl(ia.len);
}
#endif
(*state -> icmp_handler) (ia, icbuf, len);
}
return ISC_R_SUCCESS;
}
#if defined (TRACING)
void trace_icmp_input_input (trace_type_t *ttype, unsigned length, char *buf)
{
struct iaddr *ia;
unsigned len;
u_int8_t *icbuf;
ia = (struct iaddr *)buf;
ia->len = ntohl(ia->len);
icbuf = (u_int8_t *)(ia + 1);
if (icmp_state -> icmp_handler)
(*icmp_state -> icmp_handler) (*ia, icbuf,
(int)(length - sizeof ia));
}
void trace_icmp_input_stop (trace_type_t *ttype) { }
void trace_icmp_output_input (trace_type_t *ttype, unsigned length, char *buf)
{
struct icmp *icmp;
struct iaddr ia;
if (length != (sizeof (*icmp) + (sizeof ia))) {
log_error ("trace_icmp_output_input: data size mismatch %d:%d",
length, (int)((sizeof (*icmp)) + (sizeof ia)));
return;
}
ia.len = 4;
memcpy (ia.iabuf, buf, 4);
icmp = (struct icmp *)(buf + 1);
log_error ("trace_icmp_output_input: unsent ping to %s", piaddr (ia));
}
void trace_icmp_output_stop (trace_type_t *ttype) { }
#endif /* TRACING */