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- /* $Id$ */
- /*
- * Copyright (c) 2006-2007 Aaron Turner.
- * Copyright (c) 2013-2017 Fred Klassen <tcpreplay at appneta dot com> - AppNeta
- * 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 names of the copyright owners 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 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 AUTHORS OR COPYRIGHT HOLDERS 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.
- */
- #include <stdlib.h>
- #include <string.h>
- #include "tcpedit.h"
- #include "common.h"
- #include "tcpr.h"
- #include "dlt_utils.h"
- #include "tcpedit_stub.h"
- #include "pppserial.h"
- #include "pppserial_types.h"
- static char dlt_name[] = "pppserial";
- static u_int16_t dlt_value = 0x0032;
- /*
- * Function to register ourselves. This function is always called, regardless
- * of what DLT types are being used, so it shouldn't be allocating extra buffers
- * or anything like that (use the dlt_pppserial_init() function below for that).
- * Tasks:
- * - Create a new plugin struct
- * - Fill out the provides/requires bit masks. Note: Only specify which fields are
- * actually in the header.
- * - Add the plugin to the context's plugin chain
- * Returns: TCPEDIT_ERROR | TCPEDIT_OK | TCPEDIT_WARN
- */
- int
- dlt_pppserial_register(tcpeditdlt_t *ctx)
- {
- tcpeditdlt_plugin_t *plugin;
- assert(ctx);
- /* create a new plugin structure */
- plugin = tcpedit_dlt_newplugin();
- /* set what we provide & require */
- plugin->provides += PLUGIN_MASK_PROTO;
- /* plugin->requires += PLUGIN_MASK_PROTO + PLUGIN_MASK_SRCADDR + PLUGIN_MASK_DSTADDR; */
- /* what is our DLT value? */
- plugin->dlt = dlt_value;
- /* set the prefix name of our plugin. This is also used as the prefix for our options */
- plugin->name = safe_strdup(dlt_name);
- /*
- * Point to our functions, note, you need a function for EVERY method.
- * Even if it is only an empty stub returning success.
- */
- plugin->plugin_init = dlt_pppserial_init;
- plugin->plugin_post_init = dlt_pppserial_init;
- plugin->plugin_cleanup = dlt_pppserial_cleanup;
- plugin->plugin_parse_opts = dlt_pppserial_parse_opts;
- plugin->plugin_decode = dlt_pppserial_decode;
- plugin->plugin_encode = dlt_pppserial_encode;
- plugin->plugin_proto = dlt_pppserial_proto;
- plugin->plugin_l2addr_type = dlt_pppserial_l2addr_type;
- plugin->plugin_l2len = dlt_pppserial_l2len;
- plugin->plugin_get_layer3 = dlt_pppserial_get_layer3;
- plugin->plugin_merge_layer3 = dlt_pppserial_merge_layer3;
- plugin->plugin_get_mac = dlt_pppserial_get_mac;
- /* add it to the available plugin list */
- return tcpedit_dlt_addplugin(ctx, plugin);
- }
-
- /*
- * Initializer function. This function is called only once, if and only iif
- * this plugin will be utilized. Remember, if you need to keep track of any state,
- * store it in your plugin->config, not a global!
- * Returns: TCPEDIT_ERROR | TCPEDIT_OK | TCPEDIT_WARN
- */
- int
- dlt_pppserial_init(tcpeditdlt_t *ctx)
- {
- tcpeditdlt_plugin_t *plugin;
- assert(ctx);
-
- if ((plugin = tcpedit_dlt_getplugin(ctx, dlt_value)) == NULL) {
- tcpedit_seterr(ctx->tcpedit, "Unable to initialize unregistered plugin %s", dlt_name);
- return TCPEDIT_ERROR;
- }
- return TCPEDIT_OK; /* success */
- }
- /**
- * Post init function. This function is called only once after init() and parse_opts()
- * It basically allows decoders to properly initialize sub-plugins.
- */
- int
- dlt_pppserial_post_init(tcpeditdlt_t *ctx)
- {
- assert(ctx);
- /* FIXME: Only needs to do something if we're using a sub-plugin
- * See the jnpr_ether_plugin for an example of this
- pppserial_config_t *config;
-
- // do nothing if we're not the decoder
- if (ctx->decoder->dlt != dlt_value)
- return TCPEDIT_OK;
-
- // init our subcontext & decoder
- config = (pppserial_config_t *)ctx->encoder->config;
- config->subctx = tcpedit_dlt_init(ctx->tcpedit, SUB_PLUGIN_DLT_TYPE);
- */
- return TCPEDIT_OK;
- }
- /*
- * Since this is used in a library, we should manually clean up after ourselves
- * Unless you allocated some memory in dlt_pppserial_init(), this is just an stub.
- * Returns: TCPEDIT_ERROR | TCPEDIT_OK | TCPEDIT_WARN
- */
- int
- dlt_pppserial_cleanup(tcpeditdlt_t *ctx)
- {
- tcpeditdlt_plugin_t *plugin;
- assert(ctx);
- if ((plugin = tcpedit_dlt_getplugin(ctx, dlt_value)) == NULL) {
- tcpedit_seterr(ctx->tcpedit, "Unable to cleanup unregistered plugin %s", dlt_name);
- return TCPEDIT_ERROR;
- }
- /* FIXME: make this function do something if necessary */
- if (ctx->decoded_extra != NULL) {
- safe_free(ctx->decoded_extra);
- ctx->decoded_extra = NULL;
- }
-
- if (plugin->config != NULL) {
- safe_free(plugin->config);
- plugin->config = NULL;
- }
- return TCPEDIT_OK; /* success */
- }
- /*
- * This is where you should define all your AutoGen AutoOpts option parsing.
- * Any user specified option should have it's bit turned on in the 'provides'
- * bit mask.
- * Returns: TCPEDIT_ERROR | TCPEDIT_OK | TCPEDIT_WARN
- */
- int
- dlt_pppserial_parse_opts(tcpeditdlt_t *ctx)
- {
- assert(ctx);
- /* no options! nothing to do here :) */
- return TCPEDIT_OK; /* success */
- }
- /*
- * Function to decode the layer 2 header in the packet.
- * You need to fill out:
- * - ctx->l2len
- * - ctx->srcaddr
- * - ctx->dstaddr
- * - ctx->proto
- * - ctx->decoded_extra
- * Returns: TCPEDIT_ERROR | TCPEDIT_OK | TCPEDIT_WARN
- */
- int
- dlt_pppserial_decode(tcpeditdlt_t *ctx, const u_char *packet, const int pktlen)
- {
- struct tcpr_pppserial_hdr *ppp = NULL;
- assert(ctx);
- assert(packet);
- if (pktlen < 4)
- return TCPEDIT_ERROR;
- /*
- * PPP has three fields: address, control and protocol
- * address should always be 0xff, and control seems pretty meaningless.
- * protocol field informs you of the following header, but alas does not
- * use standard IEEE 802.11 values (IPv4 is not 0x0800, but is 0x0021)
- */
- ppp = (struct tcpr_pppserial_hdr *)packet;
- switch (ntohs(ppp->protocol)) {
- case 0x0021: /* IPv4 */
- ctx->proto = htons(ETHERTYPE_IP);
- ctx->l2len = 4;
- break;
- default:
- /*
- * PPP Seems to be using different protocol values then IEEE/802.x
- * but Wireshark seems to know how to decode them, so rather then
- * returning TCPEDIT_SOFT_ERROR and skipping rewrite completely,
- * I just copy the packet payload over and let Wireshark figure it out
- */
- ctx->l2len = 4;
- ctx->proto = ppp->protocol;
- }
- return TCPEDIT_OK; /* success */
- }
- /*
- * Function to encode the layer 2 header back into the packet.
- * Returns: total packet len or TCPEDIT_ERROR
- */
- int
- dlt_pppserial_encode(tcpeditdlt_t *ctx, u_char *packet, int pktlen, _U_ tcpr_dir_t dir)
- {
- assert(ctx);
- assert(packet);
-
- if (pktlen < 4)
- return TCPEDIT_ERROR;
- /* FIXME: make this function work */
-
- return pktlen; /* success */
- }
- /*
- * Function returns the Layer 3 protocol type of the given packet, or TCPEDIT_ERROR on error
- * Make sure you return this value in NETWORK byte order!
- */
- int
- dlt_pppserial_proto(tcpeditdlt_t *ctx, const u_char *packet, const int pktlen)
- {
- struct tcpr_pppserial_hdr *ppp = NULL;
- int protocol = 0;
- assert(ctx);
- assert(packet);
- if (pktlen < (int)sizeof(*ppp))
- return TCPEDIT_ERROR;
-
- ppp = (struct tcpr_pppserial_hdr *)packet;
- switch (ntohs(ppp->protocol)) {
- case 0x0021: /* IPv4 */
- protocol = ETHERTYPE_IP;
- break;
- default:
- tcpedit_seterr(ctx->tcpedit, "Packet " COUNTER_SPEC
- " isn't IP. Skipping packet",
- ctx->tcpedit->runtime.packetnum);
- return TCPEDIT_SOFT_ERROR;
- }
-
- return protocol;
- }
- /*
- * Function returns a pointer to the layer 3 protocol header or NULL on error
- */
- u_char *
- dlt_pppserial_get_layer3(tcpeditdlt_t *ctx, u_char *packet, const int pktlen)
- {
- int l2len;
- assert(ctx);
- assert(packet);
- /* FIXME: Is there anything else we need to do?? */
- l2len = dlt_pppserial_l2len(ctx, packet, pktlen);
- if (pktlen < l2len)
- return NULL;
- return tcpedit_dlt_l3data_copy(ctx, packet, pktlen, l2len);
- }
- /*
- * function merges the packet (containing L2 and old L3) with the l3data buffer
- * containing the new l3 data. Note, if L2 % 4 == 0, then they're pointing to the
- * same buffer, otherwise there was a memcpy involved on strictly aligned architectures
- * like SPARC
- */
- u_char *
- dlt_pppserial_merge_layer3(tcpeditdlt_t *ctx, u_char *packet, const int pktlen, u_char *l3data)
- {
- int l2len;
- assert(ctx);
- assert(packet);
- assert(l3data);
-
- /* FIXME: Is there anything else we need to do?? */
- l2len = dlt_pppserial_l2len(ctx, packet, pktlen);
-
- if (pktlen < l2len)
- return NULL;
-
- return tcpedit_dlt_l3data_merge(ctx, packet, pktlen, l3data, l2len);
- }
- /*
- * return a static pointer to the source/destination MAC address
- * return NULL on error/address doesn't exist
- */
- u_char *
- dlt_pppserial_get_mac(tcpeditdlt_t *ctx, tcpeditdlt_mac_type_t UNUSED(mac), const u_char *packet, const int pktlen)
- {
- assert(ctx);
- assert(packet);
- return NULL;
- }
- /*
- * return the length of the L2 header of the current packet
- */
- int
- dlt_pppserial_l2len(tcpeditdlt_t *ctx, const u_char *packet, const int pktlen)
- {
- assert(ctx);
- assert(packet);
- if (pktlen < 4)
- return 0;
- return 4;
- }
- tcpeditdlt_l2addr_type_t
- dlt_pppserial_l2addr_type(void)
- {
- return NONE;
- }
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