334 lines
9.1 KiB
C
334 lines
9.1 KiB
C
/* dhcp.c
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ICMP Protocol engine - for sending out pings and receiving
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responses. */
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/*
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* Copyright (c) 1996-2001 Internet Software Consortium.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of The Internet Software Consortium nor the names
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* of its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
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* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This software has been written for the Internet Software Consortium
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* by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
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* To learn more about the Internet Software Consortium, see
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* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
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* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
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* ``http://www.nominum.com''.
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*/
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#ifndef lint
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static char copyright[] =
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"$Id: icmp.c,v 1.1.1.12 2001/06/18 18:13:15 drochner Exp $ Copyright (c) 1996-2001 The Internet Software Consortium. All rights reserved.\n";
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#endif /* not lint */
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#include "dhcpd.h"
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#include "netinet/ip.h"
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#include "netinet/ip_icmp.h"
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struct icmp_state {
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OMAPI_OBJECT_PREAMBLE;
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int socket;
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void (*icmp_handler) PROTO ((struct iaddr, u_int8_t *, int));
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};
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static struct icmp_state *icmp_state;
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static omapi_object_type_t *dhcp_type_icmp;
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static int no_icmp;
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#if defined (TRACING)
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trace_type_t *trace_icmp_input;
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trace_type_t *trace_icmp_output;
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#endif
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/* Initialize the ICMP protocol. */
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void icmp_startup (routep, handler)
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int routep;
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void (*handler) PROTO ((struct iaddr, u_int8_t *, int));
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{
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struct protoent *proto;
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int protocol = 1;
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struct sockaddr_in from;
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int fd;
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int state;
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struct icmp_state *new;
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omapi_object_t *h;
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isc_result_t result;
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/* Only initialize icmp once. */
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if (dhcp_type_icmp)
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log_fatal ("attempted to reinitialize icmp protocol");
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result = omapi_object_type_register (&dhcp_type_icmp, "icmp",
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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sizeof (struct icmp_state), 0);
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if (result != ISC_R_SUCCESS)
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log_fatal ("Can't register icmp object type: %s",
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isc_result_totext (result));
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new = (struct icmp_state *)dmalloc (sizeof *new, MDL);
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if (!new)
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log_fatal ("Unable to allocate state for icmp protocol");
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memset (new, 0, sizeof *new);
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new -> refcnt = 1;
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new -> type = dhcp_type_icmp;
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new -> icmp_handler = handler;
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#if defined (TRACING)
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trace_icmp_input = trace_type_register ("icmp-input", (void *)0,
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trace_icmp_input_input,
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trace_icmp_input_stop, MDL);
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trace_icmp_output = trace_type_register ("icmp-output", (void *)0,
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trace_icmp_output_input,
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trace_icmp_output_stop, MDL);
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/* If we're playing back a trace file, don't create the socket
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or set up the callback. */
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if (!trace_playback ()) {
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#endif
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/* Get the protocol number (should be 1). */
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proto = getprotobyname ("icmp");
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if (proto)
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protocol = proto -> p_proto;
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/* Get a raw socket for the ICMP protocol. */
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new -> socket = socket (AF_INET, SOCK_RAW, protocol);
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if (new -> socket < 0) {
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no_icmp = 1;
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log_error ("unable to create icmp socket: %m");
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return;
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}
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#if defined (HAVE_SETFD)
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if (fcntl (new -> socket, F_SETFD, 1) < 0)
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log_error ("Can't set close-on-exec on icmp: %m");
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#endif
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/* Make sure it does routing... */
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state = 0;
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if (setsockopt (new -> socket, SOL_SOCKET, SO_DONTROUTE,
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(char *)&state, sizeof state) < 0)
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log_fatal ("Can't disable SO_DONTROUTE on ICMP: %m");
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result = omapi_register_io_object ((omapi_object_t *)new,
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icmp_readsocket, 0,
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icmp_echoreply, 0, 0);
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if (result != ISC_R_SUCCESS)
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log_fatal ("Can't register icmp handle: %s",
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isc_result_totext (result));
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#if defined (TRACING)
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}
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#endif
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icmp_state = new;
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}
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int icmp_readsocket (h)
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omapi_object_t *h;
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{
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struct icmp_state *state;
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state = (struct icmp_state *)h;
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return state -> socket;
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}
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int icmp_echorequest (addr)
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struct iaddr *addr;
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{
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struct sockaddr_in to;
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struct icmp icmp;
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int status;
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#if defined (TRACING)
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trace_iov_t iov [2];
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#endif
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if (no_icmp)
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return 1;
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if (!icmp_state)
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log_fatal ("ICMP protocol used before initialization.");
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#ifdef HAVE_SA_LEN
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to.sin_len = sizeof to;
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#endif
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to.sin_family = AF_INET;
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to.sin_port = 0; /* unused. */
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memcpy (&to.sin_addr, addr -> iabuf, sizeof to.sin_addr); /* XXX */
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icmp.icmp_type = ICMP_ECHO;
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icmp.icmp_code = 0;
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icmp.icmp_cksum = 0;
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icmp.icmp_seq = 0;
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#ifdef PTRSIZE_64BIT
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icmp.icmp_id = (((u_int32_t)(u_int64_t)addr) ^
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(u_int32_t)(((u_int64_t)addr) >> 32));
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#else
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icmp.icmp_id = (u_int32_t)addr;
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#endif
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memset (&icmp.icmp_dun, 0, sizeof icmp.icmp_dun);
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icmp.icmp_cksum = wrapsum (checksum ((unsigned char *)&icmp,
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sizeof icmp, 0));
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#if defined (TRACING)
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if (trace_playback ()) {
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char *buf = (char *)0;
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unsigned buflen = 0;
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/* Consume the ICMP event. */
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status = trace_get_packet (&trace_icmp_output, &buflen, &buf);
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if (status != ISC_R_SUCCESS)
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log_error ("icmp_echorequest: %s",
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isc_result_totext (status));
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if (buf)
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dfree (buf, MDL);
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} else {
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if (trace_record ()) {
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iov [0].buf = (char *)addr;
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iov [0].len = sizeof *addr;
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iov [1].buf = (char *)&icmp;
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iov [1].len = sizeof icmp;
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trace_write_packet_iov (trace_icmp_output,
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2, iov, MDL);
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}
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#endif
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/* Send the ICMP packet... */
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status = sendto (icmp_state -> socket,
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(char *)&icmp, sizeof icmp, 0,
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(struct sockaddr *)&to, sizeof to);
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if (status < 0)
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log_error ("icmp_echorequest %s: %m",
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inet_ntoa(to.sin_addr));
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if (status != sizeof icmp)
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return 0;
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#if defined (TRACING)
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}
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#endif
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return 1;
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}
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isc_result_t icmp_echoreply (h)
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omapi_object_t *h;
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{
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struct icmp *icfrom;
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struct ip *ip;
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struct sockaddr_in from;
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u_int8_t icbuf [1500];
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int status;
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SOCKLEN_T sl;
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int hlen, len;
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struct iaddr ia;
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struct icmp_state *state;
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#if defined (TRACING)
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trace_iov_t iov [2];
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#endif
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state = (struct icmp_state *)h;
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sl = sizeof from;
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status = recvfrom (state -> socket, (char *)icbuf, sizeof icbuf, 0,
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(struct sockaddr *)&from, &sl);
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if (status < 0) {
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log_error ("icmp_echoreply: %m");
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return ISC_R_UNEXPECTED;
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}
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/* Find the IP header length... */
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ip = (struct ip *)icbuf;
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hlen = IP_HL (ip);
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/* Short packet? */
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if (status < hlen + (sizeof *icfrom)) {
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return ISC_R_SUCCESS;
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}
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len = status - hlen;
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icfrom = (struct icmp *)(icbuf + hlen);
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/* Silently discard ICMP packets that aren't echoreplies. */
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if (icfrom -> icmp_type != ICMP_ECHOREPLY) {
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return ISC_R_SUCCESS;
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}
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/* If we were given a second-stage handler, call it. */
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if (state -> icmp_handler) {
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memcpy (ia.iabuf, &from.sin_addr, sizeof from.sin_addr);
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ia.len = sizeof from.sin_addr;
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#if defined (TRACING)
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if (trace_record ()) {
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ia.len = htonl(ia.len);
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iov [0].buf = (char *)&ia;
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iov [0].len = sizeof ia;
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iov [1].buf = (char *)icbuf;
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iov [1].len = len;
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trace_write_packet_iov (trace_icmp_input, 2, iov, MDL);
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ia.len = ntohl(ia.len);
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}
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#endif
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(*state -> icmp_handler) (ia, icbuf, len);
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}
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return ISC_R_SUCCESS;
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}
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#if defined (TRACING)
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void trace_icmp_input_input (trace_type_t *ttype, unsigned length, char *buf)
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{
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struct iaddr *ia;
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unsigned len;
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u_int8_t *icbuf;
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ia = (struct iaddr *)buf;
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ia->len = ntohl(ia->len);
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icbuf = (u_int8_t *)(ia + 1);
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if (icmp_state -> icmp_handler)
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(*icmp_state -> icmp_handler) (*ia, icbuf,
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(int)(length - sizeof ia));
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}
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void trace_icmp_input_stop (trace_type_t *ttype) { }
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void trace_icmp_output_input (trace_type_t *ttype, unsigned length, char *buf)
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{
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struct icmp *icmp;
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struct iaddr *ia;
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if (length != (sizeof (*icmp) + (sizeof *ia))) {
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log_error ("trace_icmp_output_input: data size mismatch %d:%d",
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length, (int)((sizeof (*icmp)) + (sizeof *ia)));
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return;
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}
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ia = (struct iaddr *)buf;
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icmp = (struct icmp *)(ia + 1);
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log_error ("trace_icmp_output_input: unsent ping to %s", piaddr (*ia));
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}
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void trace_icmp_output_stop (trace_type_t *ttype) { }
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#endif /* TRACING */
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