1 files changed, 425 insertions, 0 deletions
diff --git a/src/tcpedit/plugins/dlt_plugins.c b/src/tcpedit/plugins/dlt_plugins.c
new file mode 100644
index 0000000..7aaad34
--- /dev/null
+++ b/src/tcpedit/plugins/dlt_plugins.c
@@ -0,0 +1,425 @@
+/* $Id: dlt_plugins.c 2423 2010-03-13 07:09:49Z aturner $ */
+
+/*
+ * Copyright (c) 2006-2010 Aaron Turner.
+ * 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 "config.h"
+
+#include <stdlib.h>
+
+#include "dlt_plugins-int.h"
+#include "dlt_utils.h"
+#include "common.h"
+
+/**
+ * Include plugin header files here...
+ */
+#include "dlt_en10mb/en10mb.h"
+#include "dlt_user/user.h"
+#include "dlt_hdlc/hdlc.h"
+#include "dlt_raw/raw.h"
+#include "dlt_null/null.h"
+#include "dlt_loop/loop.h"
+#include "dlt_linuxsll/linuxsll.h"
+#include "dlt_ieee80211/ieee80211.h"
+#include "dlt_radiotap/radiotap.h"
+
+
+/**
+ * Everyone writing a DLT plugin, must add their registration function
+ * here.
+ */
+int 
+tcpedit_dlt_register(tcpeditdlt_t *ctx)
+{
+    int retcode = 0;
+    assert(ctx);
+    
+    retcode += dlt_en10mb_register(ctx);
+    retcode += dlt_hdlc_register(ctx);
+    retcode += dlt_user_register(ctx);
+    retcode += dlt_raw_register(ctx);
+    retcode += dlt_null_register(ctx);
+    retcode += dlt_loop_register(ctx);
+    retcode += dlt_linuxsll_register(ctx);
+    retcode += dlt_ieee80211_register(ctx);
+    retcode += dlt_radiotap_register(ctx);
+    
+    if (retcode < 0)
+        return TCPEDIT_ERROR;
+    
+    return TCPEDIT_OK;
+}
+
+
+
+/********************************************************************
+ * People writing DLT plugins should stop editing here!
+ *
+ * Well actually, that's true most of the time, but feel free to take
+ * a look!
+ ********************************************************************/
+
+/* 
+ * mapping for bit_mask to bit_info.  If you're making changes here
+ * then you almost certainly need to modify tcpeditdlt_t in dlt_plugins-int.h
+ */
+const u_int32_t tcpeditdlt_bit_map[] = {
+    PLUGIN_MASK_PROTO,
+    PLUGIN_MASK_SRCADDR,
+    PLUGIN_MASK_DSTADDR
+};
+
+/* Meanings of the above map */
+const char *tcpeditdlt_bit_info[] = {
+    "Missing required Layer 3 protocol.",
+    "Missing required Layer 2 source address.",
+    "Missing required Layer 2 destination address."
+};
+ 
+/*********************************************************************
+ * Internal functions
+ ********************************************************************/
+
+/*********************************************************************
+ * Public functions
+ ********************************************************************/
+ 
+/**
+ * initialize our plugin library.  Pass the DLT of the source pcap handle.
+ * Actions:
+ * - Create new tcpeditdlt_t context
+ * - Link tcpedit to new context
+ * - Register plugins
+ * - Select decoder plugin using srcdlt
+ * - Select encoder plugin using destination name
+ * - Initialize decoder/encoder plugins
+ * - Parse options for encoder plugin
+ * - Validate provides/reqiures + user options
+ */
+tcpeditdlt_t *
+tcpedit_dlt_init(tcpedit_t *tcpedit, const int srcdlt) 
+{
+    tcpeditdlt_t *ctx;
+    int rcode;
+    const char *dst_dlt_name = NULL;
+
+    assert(tcpedit);
+    assert(srcdlt >= 0);
+
+    ctx = (tcpeditdlt_t *)safe_malloc(sizeof(tcpeditdlt_t));
+
+    /* do we need a side buffer for L3 data? */
+#ifdef FORCE_ALIGN
+    ctx->l3buff = (u_char *)safe_malloc(MAXPACKET);
+#endif
+
+    /* copy our tcpedit context */
+    ctx->tcpedit = tcpedit;
+
+    /* register all our plugins */
+    if (tcpedit_dlt_register(ctx) != TCPEDIT_OK) {
+        goto INIT_ERROR;
+    }
+
+    /* Choose decode plugin */
+    if ((ctx->decoder = tcpedit_dlt_getplugin(ctx, srcdlt)) == NULL) {
+        tcpedit_seterr(tcpedit, "No DLT plugin available for source DLT: 0x%x", srcdlt);
+        goto INIT_ERROR;
+    }
+
+    /* set our dlt type */
+    ctx->dlt = srcdlt;
+
+    /* set our address type */
+    ctx->addr_type = ctx->decoder->plugin_l2addr_type();
+
+    /* initalize decoder plugin */
+    rcode = ctx->decoder->plugin_init(ctx);
+    if (tcpedit_checkerror(ctx->tcpedit, rcode, NULL) != TCPEDIT_OK) {
+        goto INIT_ERROR;
+    }
+
+    /* Select the encoder plugin */
+    dst_dlt_name = OPT_ARG(DLT) ? OPT_ARG(DLT) : ctx->decoder->name;
+    if ((ctx->encoder = tcpedit_dlt_getplugin_byname(ctx, dst_dlt_name)) == NULL) {
+        tcpedit_seterr(tcpedit, "No output DLT plugin available for: %s", dst_dlt_name);
+        goto INIT_ERROR;
+    }
+    
+    /* Figure out if we're skipping braodcast & multicast */
+    if (HAVE_OPT(SKIPL2BROADCAST))
+        ctx->skip_broadcast = 1;
+
+    /* init encoder plugin if it's not the decoder plugin */
+    if (ctx->encoder->dlt != ctx->decoder->dlt) {
+        rcode = ctx->encoder->plugin_init(ctx);
+        if (tcpedit_checkerror(ctx->tcpedit, rcode, NULL) != TCPEDIT_OK) {
+            goto INIT_ERROR;
+        }
+    }
+
+    /* parse the DLT specific options */
+    rcode = tcpedit_dlt_parse_opts(ctx);
+    if (tcpedit_checkerror(ctx->tcpedit, rcode, "parsing options") != TCPEDIT_OK) {
+        goto INIT_ERROR;
+    }
+
+
+    /* validate that the SRC/DST DLT + options give us enough info */
+    rcode = tcpedit_dlt_validate(ctx);
+    if (tcpedit_checkerror(ctx->tcpedit, rcode, "validating options") != TCPEDIT_OK) {
+        goto INIT_ERROR;
+    }
+
+    /* we're OK */
+    return ctx;
+
+INIT_ERROR:
+    tcpedit_dlt_cleanup(ctx);
+    return NULL;
+}
+ 
+
+/**
+ * This is the recommended method to edit a packet.  Returns (new) total packet length
+ * FIXME: This is *broken*.  taking packet as a u_char*, but using it as a u_char **!
+ */
+int
+tcpedit_dlt_process(tcpeditdlt_t *ctx, u_char **packet, int pktlen, tcpr_dir_t direction)
+{
+    int rcode;
+    
+    assert(ctx);
+    assert(packet);
+    assert(pktlen);
+    assert(direction == TCPR_DIR_C2S || direction == TCPR_DIR_S2C || direction == TCPR_DIR_NOSEND);
+    
+    /* nothing to do here */
+    if (direction == TCPR_DIR_NOSEND)
+        return pktlen;
+    
+    /* decode packet */    
+    if ((rcode = tcpedit_dlt_decode(ctx, *packet, pktlen)) == TCPEDIT_ERROR) {
+        return TCPEDIT_ERROR;
+    } else if (rcode == TCPEDIT_WARN) {
+        warnx("Warning decoding packet: %s", tcpedit_getwarn(ctx->tcpedit));
+    } else if (rcode == TCPEDIT_SOFT_ERROR) {
+        return rcode; /* can't edit the packet */
+    }
+    
+    /* encode packet */
+    if ((rcode = tcpedit_dlt_encode(ctx, *packet, pktlen, direction)) == TCPEDIT_ERROR) {
+        return TCPEDIT_ERROR;
+    } else if (rcode == TCPEDIT_WARN) {
+        warnx("Warning encoding packet: %s", tcpedit_getwarn(ctx->tcpedit));
+    }
+       
+    return rcode;
+}
+
+
+/**
+ * What is the output DLT type???
+ */
+int 
+tcpedit_dlt_output_dlt(tcpeditdlt_t *ctx)
+{
+    u_int16_t dlt;
+    assert(ctx);
+        
+    /* 
+     * usually we just return the DLT value of the decoder, but for DLT_USER0
+     * we return a user-specified value via --user-dlt
+     */
+    if (ctx->encoder->dlt == DLT_USER0) {
+        dlt = dlt_user_get_output_dlt(ctx);
+    } else {
+        dlt = ctx->encoder->dlt;
+    }
+    return dlt;
+}
+
+/**
+ * Get the layer 2 length of the packet using the DLT plugin currently in
+ * place
+ */
+int
+tcpedit_dlt_l2len(tcpeditdlt_t *ctx, int dlt, const u_char *packet, const int pktlen)
+{
+    tcpeditdlt_plugin_t *plugin;
+    assert(ctx);
+    assert(dlt >= 0);
+    assert(packet);
+    assert(pktlen);
+    
+    if ((plugin = tcpedit_dlt_getplugin(ctx, dlt)) == NULL) {
+        tcpedit_seterr(ctx->tcpedit, "Unable to find plugin for DLT 0x%04x", dlt);
+        return -1;        
+    }
+    return plugin->plugin_l2len(ctx, packet, pktlen);
+}
+
+/**
+ * Get the L3 type.  Returns -1 on error.  Get error via tcpedit->geterr()
+ */
+int
+tcpedit_dlt_proto(tcpeditdlt_t *ctx, int dlt, const u_char *packet, const int pktlen)
+{
+    tcpeditdlt_plugin_t *plugin;
+
+    assert(ctx);
+    assert(dlt >= 0);
+    assert(packet);
+    assert(pktlen);
+
+    if ((plugin = tcpedit_dlt_getplugin(ctx, dlt)) == NULL) {
+        tcpedit_seterr(ctx->tcpedit, "Unable to find plugin for DLT 0x%04x", dlt);
+        return -1;
+    }
+    
+    return plugin->plugin_proto(ctx, packet, pktlen);
+}
+
+/**
+ * Get the L3 data.  Returns NULL on error.  Get error via tcpedit->geterr()
+ */
+u_char *
+tcpedit_dlt_l3data(tcpeditdlt_t *ctx, int dlt, u_char *packet, const int pktlen)
+{
+    tcpeditdlt_plugin_t *plugin;
+
+    assert(ctx);
+    assert(dlt >= 0);
+    assert(packet);
+    assert(pktlen);
+        
+    if ((plugin = tcpedit_dlt_getplugin(ctx, dlt)) == NULL) {
+        tcpedit_seterr(ctx->tcpedit, "Unable to find plugin for DLT 0x%04x", dlt);
+        return NULL;
+    }
+
+    return plugin->plugin_get_layer3(ctx, packet, pktlen);
+}
+
+/**
+ * \brief Merge the Layer 3 data back onto the mainbuffer so it's immediately
+ *   after the layer 2 header
+ * 
+ * Since some L2 headers aren't strictly aligned, we need to "merge" the packet w/ L2 data
+ * and the L3 buffer.  This is basically a NO-OP for things like vlan tagged ethernet (16 byte) header
+ * or Cisco HDLC (4 byte header) but is critical for std ethernet (12 byte header)
+ */
+u_char *
+tcpedit_dlt_merge_l3data(tcpeditdlt_t *ctx, int dlt, u_char *packet, const int pktlen, u_char *l3data)
+{
+    tcpeditdlt_plugin_t *plugin;
+    assert(ctx);
+    assert(dlt >= 0);
+    assert(pktlen >= 0);
+    assert(packet);
+
+    if (l3data == NULL)
+        return packet;
+        
+    if ((plugin = tcpedit_dlt_getplugin(ctx, dlt)) == NULL) {
+        tcpedit_seterr(ctx->tcpedit, "Unable to find plugin for DLT 0x%04x", dlt);
+        return NULL;
+    }
+
+    return plugin->plugin_merge_layer3(ctx, packet, pktlen, l3data);
+}
+
+
+
+/**
+ * Call the specific plugin decode() method
+ */
+int 
+tcpedit_dlt_decode(tcpeditdlt_t *ctx, const u_char *packet, const int pktlen)
+{
+    return ctx->decoder->plugin_decode(ctx, packet, pktlen);
+}
+
+/**
+ * Call the specific plugin encode() method
+ */
+int 
+tcpedit_dlt_encode(tcpeditdlt_t* ctx, u_char *packet, int pktlen, tcpr_dir_t direction)
+{
+    return ctx->encoder->plugin_encode(ctx, packet, pktlen, direction);
+}
+
+/**
+ * what is the source (decoder) DLT type?
+ */
+int 
+tcpedit_dlt_src(tcpeditdlt_t *ctx)
+{
+    assert(ctx);
+    return ctx->decoder->dlt;
+}
+
+/**
+ * What is the destination (encoder) DLT type
+ */
+int 
+tcpedit_dlt_dst(tcpeditdlt_t *ctx)
+{
+   assert(ctx);
+   return ctx->encoder->dlt; 
+}
+
+
+/**
+ * cleanup after ourselves: destroys our context and all plugin data
+ */
+void
+tcpedit_dlt_cleanup(tcpeditdlt_t *ctx)
+{
+    assert(ctx);
+    
+    if (ctx->encoder != NULL)
+        ctx->encoder->plugin_cleanup(ctx);
+    
+    if (ctx->decoder != NULL)
+        ctx->decoder->plugin_cleanup(ctx);
+
+#ifdef FORCE_ALIGN
+    safe_free(ctx->l3buff);
+#endif
+
+    if (ctx->decoded_extra != NULL)
+        safe_free(ctx->decoded_extra);
+        
+    safe_free(ctx);
+}
+
+