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/*
* Copyright (c) 1988-1997
* The Regents of the University of California. All rights reserved.
*
* Copyright (c) 1998-2012 Michael Richardson <mcr@tcpdump.org>
* The TCPDUMP project
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include "netdissect.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef USE_LIBSMI
#include <smi.h>
#endif
/*
* Initialize anything that must be initialized before dissecting
* packets.
*
* This should be called at the beginning of the program; it does
* not need to be called, and should not be called, for every
* netdissect_options structure.
*/
int
nd_init(char *errbuf, size_t errbuf_size)
{
#ifdef _WIN32
WORD wVersionRequested;
WSADATA wsaData;
int err;
/*
* Request Winsock 2.2; we expect Winsock 2.
*/
wVersionRequested = MAKEWORD(2, 2);
err = WSAStartup(wVersionRequested, &wsaData);
if (err != 0) {
strlcpy(errbuf, "Attempting to initialize Winsock failed",
errbuf_size);
return (-1);
}
#endif /* _WIN32 */
#ifdef USE_LIBSMI
/*
* XXX - should we just fail if this fails? Some of the
* libsmi calls may fail.
*/
smiInit("tcpdump");
#endif
/*
* Clears the error buffer, and uses it so we don't get
* "unused argument" warnings at compile time.
*/
strlcpy(errbuf, "", errbuf_size);
return (0);
}
/*
* Clean up anything that ndo_init() did.
*/
void
nd_cleanup(void)
{
#ifdef USE_LIBSMI
/*
* This appears, in libsmi 0.4.8, to do nothing if smiInit()
* wasn't done or failed, so we call it unconditionally.
*/
smiExit();
#endif
#ifdef _WIN32
/*
* Undo the WSAStartup() call above.
*/
WSACleanup();
#endif
}
int
nd_have_smi_support(void)
{
#ifdef USE_LIBSMI
return (1);
#else
return (0);
#endif
}
/*
* Indicates whether an SMI module has been loaded, so that we can use
* libsmi to translate OIDs.
*/
int nd_smi_module_loaded;
int
nd_load_smi_module(const char *module, char *errbuf, size_t errbuf_size)
{
#ifdef USE_LIBSMI
if (smiLoadModule(module) == 0) {
snprintf(errbuf, errbuf_size, "could not load MIB module %s",
module);
return (-1);
}
nd_smi_module_loaded = 1;
return (0);
#else
snprintf(errbuf, errbuf_size, "MIB module %s not loaded: no libsmi support",
module);
return (-1);
#endif
}
const char *
nd_smi_version_string(void)
{
#ifdef USE_LIBSMI
return (smi_version_string);
#else
return (NULL);
#endif
}
int
nd_push_buffer(netdissect_options *ndo, u_char *new_buffer,
const u_char *new_packetp, const u_char *new_snapend)
{
struct netdissect_saved_packet_info *ndspi;
ndspi = (struct netdissect_saved_packet_info *)malloc(sizeof(struct netdissect_saved_packet_info));
if (ndspi == NULL)
return (0); /* fail */
ndspi->ndspi_buffer = new_buffer;
ndspi->ndspi_packetp = ndo->ndo_packetp;
ndspi->ndspi_snapend = ndo->ndo_snapend;
ndspi->ndspi_prev = ndo->ndo_packet_info_stack;
ndo->ndo_packetp = new_packetp;
ndo->ndo_snapend = new_snapend;
ndo->ndo_packet_info_stack = ndspi;
return (1); /* success */
}
/*
* Set a new snapshot end to the minimum of the existing snapshot end
* and the new snapshot end.
*/
int
nd_push_snapend(netdissect_options *ndo, const u_char *new_snapend)
{
struct netdissect_saved_packet_info *ndspi;
ndspi = (struct netdissect_saved_packet_info *)malloc(sizeof(struct netdissect_saved_packet_info));
if (ndspi == NULL)
return (0); /* fail */
ndspi->ndspi_buffer = NULL; /* no new buffer */
ndspi->ndspi_packetp = ndo->ndo_packetp;
ndspi->ndspi_snapend = ndo->ndo_snapend;
ndspi->ndspi_prev = ndo->ndo_packet_info_stack;
/* No new packet pointer, either */
if (new_snapend < ndo->ndo_snapend)
ndo->ndo_snapend = new_snapend;
ndo->ndo_packet_info_stack = ndspi;
return (1); /* success */
}
/*
* Change an already-pushed snapshot end. This may increase the
* snapshot end, as it may be used, for example, for a Jumbo Payload
* option in IPv6. It must not increase it past the snapshot length
* atop which the current one was pushed, however.
*/
void
nd_change_snapend(netdissect_options *ndo, const u_char *new_snapend)
{
struct netdissect_saved_packet_info *ndspi;
ndspi = ndo->ndo_packet_info_stack;
if (ndspi->ndspi_prev != NULL) {
if (new_snapend <= ndspi->ndspi_prev->ndspi_snapend)
ndo->ndo_snapend = new_snapend;
} else {
if (new_snapend < ndo->ndo_snapend)
ndo->ndo_snapend = new_snapend;
}
}
void
nd_pop_packet_info(netdissect_options *ndo)
{
struct netdissect_saved_packet_info *ndspi;
ndspi = ndo->ndo_packet_info_stack;
ndo->ndo_packetp = ndspi->ndspi_packetp;
ndo->ndo_snapend = ndspi->ndspi_snapend;
ndo->ndo_packet_info_stack = ndspi->ndspi_prev;
free(ndspi->ndspi_buffer);
free(ndspi);
}
void
nd_pop_all_packet_info(netdissect_options *ndo)
{
while (ndo->ndo_packet_info_stack != NULL)
nd_pop_packet_info(ndo);
}
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