![Guy Harris](/assets/img/avatar_default.png)
add a "match_strval_idx()" routine that does the same thing, and have "match_strval()" call it. Make those routines, and "val_to_str()", return a "const" pointer. Update dissectors as necessary to squelch compiler warnings produced by that. Use "val_to_str()" rather than using "match_strval()" and then, if the result is null, substituting a specific string. Clean up some other "match_strval()"/"val_to_str()" usages. Add a null pointer check in the NDPS dissector's "attribute_value()" routine, as it's not clear that "global_attribute_name" won't be null at that point. Make some global variables in the AFS4INT dissector local. Make some routines not used outside the module they're in static. Make some tables "static const". Clean up white space. Fix Gerald's address in some files. svn path=/trunk/; revision=14786
431 lines
13 KiB
C
431 lines
13 KiB
C
/* packet-ipsec.c
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* Routines for IPsec/IPComp packet disassembly
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*
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* $Id$
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <stdio.h>
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#include <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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#include "packet-ipsec.h"
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#include <epan/addr_resolv.h>
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#include <epan/ipproto.h>
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#include <epan/prefs.h>
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/* Place AH payload in sub tree */
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static gboolean g_ah_payload_in_subtree = FALSE;
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/* Default ESP payload decode to off (only works if payload is NULL encrypted) */
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static gboolean g_esp_enable_null_encryption_decode_heuristic = FALSE;
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static int proto_ah = -1;
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static int hf_ah_spi = -1;
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static int hf_ah_sequence = -1;
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static int proto_esp = -1;
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static int hf_esp_spi = -1;
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static int hf_esp_sequence = -1;
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static int hf_esp_pad = -1;
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static int hf_esp_protocol = -1;
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static int proto_ipcomp = -1;
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static int hf_ipcomp_flags = -1;
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static int hf_ipcomp_cpi = -1;
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static gint ett_ah = -1;
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static gint ett_esp = -1;
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static gint ett_ipcomp = -1;
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static dissector_handle_t data_handle;
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static dissector_table_t ip_dissector_table;
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struct newah {
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guint8 ah_nxt; /* Next Header */
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guint8 ah_len; /* Length of data + 1, in 32bit */
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guint16 ah_reserve; /* Reserved for future use */
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guint32 ah_spi; /* Security parameter index */
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guint32 ah_seq; /* Sequence number field */
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/* variable size, 32bit bound*/ /* Authentication data */
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};
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struct newesp {
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guint32 esp_spi; /* ESP */
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guint32 esp_seq; /* Sequence number */
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/*variable size*/ /* (IV and) Payload data */
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/*variable size*/ /* padding */
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/*8bit*/ /* pad size */
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/*8bit*/ /* next header */
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/*8bit*/ /* next header */
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/*variable size, 32bit bound*/ /* Authentication data */
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};
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struct ipcomp {
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guint8 comp_nxt; /* Next Header */
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guint8 comp_flags; /* Must be zero */
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guint16 comp_cpi; /* Compression parameter index */
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};
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/* well-known algorithm number (in CPI), from RFC2409 */
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#define IPCOMP_OUI 1 /* vendor specific */
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#define IPCOMP_DEFLATE 2 /* RFC2394 */
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#define IPCOMP_LZS 3 /* RFC2395 */
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#define IPCOMP_MAX 4
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static const value_string cpi2val[] = {
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{ IPCOMP_OUI, "OUI" },
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{ IPCOMP_DEFLATE, "DEFLATE" },
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{ IPCOMP_LZS, "LZS" },
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{ 0, NULL },
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};
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#ifndef offsetof
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#define offsetof(type, member) ((size_t)(&((type *)0)->member))
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#endif
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static void
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dissect_ah(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *next_tree;
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guint8 nxt;
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tvbuff_t *next_tvb;
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int advance;
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advance = dissect_ah_header(tvb, pinfo, tree, &nxt, &next_tree);
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next_tvb = tvb_new_subset(tvb, advance, -1, -1);
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if (g_ah_payload_in_subtree) {
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col_set_writable(pinfo->cinfo, FALSE);
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}
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/* do lookup with the subdissector table */
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if (!dissector_try_port(ip_dissector_table, nxt, next_tvb, pinfo, next_tree)) {
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call_dissector(data_handle,next_tvb, pinfo, next_tree);
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}
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}
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int
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dissect_ah_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
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guint8 *nxt_p, proto_tree **next_tree_p)
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{
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proto_tree *ah_tree;
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proto_item *ti;
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struct newah ah;
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int advance;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "AH");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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tvb_memcpy(tvb, (guint8 *)&ah, 0, sizeof(ah));
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advance = sizeof(ah) + ((ah.ah_len - 1) << 2);
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if (check_col(pinfo->cinfo, COL_INFO)) {
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col_add_fstr(pinfo->cinfo, COL_INFO, "AH (SPI=0x%08x)",
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(guint32)g_ntohl(ah.ah_spi));
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}
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if (tree) {
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/* !!! specify length */
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ti = proto_tree_add_item(tree, proto_ah, tvb, 0, advance, FALSE);
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ah_tree = proto_item_add_subtree(ti, ett_ah);
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proto_tree_add_text(ah_tree, tvb,
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offsetof(struct newah, ah_nxt), 1,
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"Next Header: %s (0x%02x)",
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ipprotostr(ah.ah_nxt), ah.ah_nxt);
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proto_tree_add_text(ah_tree, tvb,
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offsetof(struct newah, ah_len), 1,
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"Length: %u", (ah.ah_len + 2) << 2);
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proto_tree_add_uint(ah_tree, hf_ah_spi, tvb,
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offsetof(struct newah, ah_spi), 4,
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(guint32)g_ntohl(ah.ah_spi));
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proto_tree_add_uint(ah_tree, hf_ah_sequence, tvb,
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offsetof(struct newah, ah_seq), 4,
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(guint32)g_ntohl(ah.ah_seq));
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proto_tree_add_text(ah_tree, tvb,
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sizeof(ah), (ah.ah_len) ? (ah.ah_len - 1) << 2 : 0,
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"ICV");
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if (next_tree_p != NULL) {
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/* Decide where to place next protocol decode */
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if (g_ah_payload_in_subtree) {
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*next_tree_p = ah_tree;
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}
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else {
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*next_tree_p = tree;
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}
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}
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} else {
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if (next_tree_p != NULL)
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*next_tree_p = NULL;
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}
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if (nxt_p != NULL)
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*nxt_p = ah.ah_nxt;
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/* start of the new header (could be a extension header) */
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return advance;
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}
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static void
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dissect_esp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *esp_tree;
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proto_item *ti;
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struct newesp esp;
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/*
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* load the top pane info. This should be overwritten by
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* the next protocol in the stack
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*/
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "ESP");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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tvb_memcpy(tvb, (guint8 *)&esp, 0, sizeof(esp));
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if (check_col(pinfo->cinfo, COL_INFO)) {
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col_add_fstr(pinfo->cinfo, COL_INFO, "ESP (SPI=0x%08x)",
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(guint32)g_ntohl(esp.esp_spi));
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}
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/*
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* populate a tree in the second pane with the status of the link layer
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* (ie none)
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*/
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if(tree) {
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int len = 0, pad = 0, encapsulated_protocol = 0;
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gboolean auth_decode_ok = FALSE;
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ti = proto_tree_add_item(tree, proto_esp, tvb, 0, -1, FALSE);
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esp_tree = proto_item_add_subtree(ti, ett_esp);
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proto_tree_add_uint(esp_tree, hf_esp_spi, tvb,
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offsetof(struct newesp, esp_spi), 4,
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(guint32)g_ntohl(esp.esp_spi));
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proto_tree_add_uint(esp_tree, hf_esp_sequence, tvb,
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offsetof(struct newesp, esp_seq), 4,
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(guint32)g_ntohl(esp.esp_seq));
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if(g_esp_enable_null_encryption_decode_heuristic)
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{
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/* Get length of whole ESP packet. */
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len = tvb_reported_length(tvb);
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/* Make sure the packet is not truncated before the fields
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* we need to read to determine the encapsulated protocol */
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if(tvb_bytes_exist(tvb, len - 14, 2))
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{
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pad = tvb_get_guint8(tvb, len - 14);
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encapsulated_protocol = tvb_get_guint8(tvb, len - 13);
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if(dissector_try_port(ip_dissector_table,
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encapsulated_protocol,
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tvb_new_subset(tvb,
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sizeof(struct newesp),
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-1,
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len - sizeof(struct newesp) - 14 - pad),
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pinfo,
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esp_tree))
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{
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auth_decode_ok = TRUE;
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}
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}
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}
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if(auth_decode_ok)
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{
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proto_tree_add_uint(esp_tree, hf_esp_pad, tvb,
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len - 14, 1,
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pad);
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proto_tree_add_uint(esp_tree, hf_esp_protocol, tvb,
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len - 13, 1,
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encapsulated_protocol);
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/* Make sure we have the auth trailer data */
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if(tvb_bytes_exist(tvb, len - 12, 12))
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{
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proto_tree_add_text(esp_tree, tvb, len - 12, 12,
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"Authentication Data");
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}
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else
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{
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/* Truncated so just display what we have */
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proto_tree_add_text(esp_tree, tvb, len - 12, 12 - (len - tvb_length(tvb)),
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"Authentication Data (truncated)");
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}
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}
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else
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{
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call_dissector(data_handle,
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tvb_new_subset(tvb, sizeof(struct newesp), -1, -1),
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pinfo, esp_tree);
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}
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}
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}
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static void
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dissect_ipcomp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *ipcomp_tree;
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proto_item *ti;
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struct ipcomp ipcomp;
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const char *p;
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/*
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* load the top pane info. This should be overwritten by
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* the next protocol in the stack
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*/
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "IPComp");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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tvb_memcpy(tvb, (guint8 *)&ipcomp, 0, sizeof(ipcomp));
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if (check_col(pinfo->cinfo, COL_INFO)) {
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p = match_strval(g_ntohs(ipcomp.comp_cpi), cpi2val);
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if (p == NULL) {
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col_add_fstr(pinfo->cinfo, COL_INFO, "IPComp (CPI=0x%04x)",
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g_ntohs(ipcomp.comp_cpi));
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} else
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col_add_fstr(pinfo->cinfo, COL_INFO, "IPComp (CPI=%s)", p);
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}
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/*
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* populate a tree in the second pane with the status of the link layer
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* (ie none)
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*/
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if (tree) {
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ti = proto_tree_add_item(tree, proto_ipcomp, tvb, 0, -1, FALSE);
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ipcomp_tree = proto_item_add_subtree(ti, ett_ipcomp);
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proto_tree_add_text(ipcomp_tree, tvb,
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offsetof(struct ipcomp, comp_nxt), 1,
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"Next Header: %s (0x%02x)",
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ipprotostr(ipcomp.comp_nxt), ipcomp.comp_nxt);
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proto_tree_add_uint(ipcomp_tree, hf_ipcomp_flags, tvb,
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offsetof(struct ipcomp, comp_flags), 1,
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ipcomp.comp_flags);
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proto_tree_add_uint(ipcomp_tree, hf_ipcomp_cpi, tvb,
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offsetof(struct ipcomp, comp_cpi), 2,
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g_ntohs(ipcomp.comp_cpi));
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call_dissector(data_handle,
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tvb_new_subset(tvb, sizeof(struct ipcomp), -1, -1), pinfo,
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ipcomp_tree);
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}
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}
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void
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proto_register_ipsec(void)
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{
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static hf_register_info hf_ah[] = {
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{ &hf_ah_spi,
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{ "SPI", "ah.spi", FT_UINT32, BASE_HEX, NULL, 0x0,
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"", HFILL }},
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{ &hf_ah_sequence,
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{ "Sequence", "ah.sequence", FT_UINT32, BASE_DEC, NULL, 0x0,
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"", HFILL }}
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};
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static hf_register_info hf_esp[] = {
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{ &hf_esp_spi,
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{ "SPI", "esp.spi", FT_UINT32, BASE_HEX, NULL, 0x0,
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"", HFILL }},
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{ &hf_esp_sequence,
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{ "Sequence", "esp.sequence", FT_UINT32, BASE_DEC, NULL, 0x0,
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"", HFILL }},
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{ &hf_esp_pad,
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{ "Pad Length", "esp.pad", FT_UINT8, BASE_DEC, NULL, 0x0,
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"", HFILL }},
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{ &hf_esp_protocol,
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{ "Next Header", "esp.protocol", FT_UINT8, BASE_HEX, NULL, 0x0,
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"", HFILL }}
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};
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static hf_register_info hf_ipcomp[] = {
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{ &hf_ipcomp_flags,
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{ "Flags", "ipcomp.flags", FT_UINT8, BASE_HEX, NULL, 0x0,
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"", HFILL }},
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{ &hf_ipcomp_cpi,
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{ "CPI", "ipcomp.cpi", FT_UINT16, BASE_HEX,
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VALS(cpi2val), 0x0, "", HFILL }},
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};
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static gint *ett[] = {
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&ett_ah,
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&ett_esp,
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&ett_ipcomp,
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};
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module_t *ah_module;
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module_t *esp_module;
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proto_ah = proto_register_protocol("Authentication Header", "AH", "ah");
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proto_register_field_array(proto_ah, hf_ah, array_length(hf_ah));
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proto_esp = proto_register_protocol("Encapsulating Security Payload",
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"ESP", "esp");
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proto_register_field_array(proto_esp, hf_esp, array_length(hf_esp));
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proto_ipcomp = proto_register_protocol("IP Payload Compression",
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"IPComp", "ipcomp");
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proto_register_field_array(proto_ipcomp, hf_ipcomp, array_length(hf_ipcomp));
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proto_register_subtree_array(ett, array_length(ett));
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/* Register a configuration option for placement of AH payload dissection */
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ah_module = prefs_register_protocol(proto_ah, NULL);
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prefs_register_bool_preference(ah_module, "place_ah_payload_in_subtree",
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"Place AH payload in subtree",
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"Whether the AH payload decode should be placed in a subtree",
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&g_ah_payload_in_subtree);
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esp_module = prefs_register_protocol(proto_esp, NULL);
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prefs_register_bool_preference(esp_module, "enable_null_encryption_decode_heuristic",
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"Attempt to detect/decode NULL encrypted ESP payloads",
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"Assumes a 12 byte auth (SHA1/MD5) and attempts decode based on the ethertype 13 bytes from packet end",
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&g_esp_enable_null_encryption_decode_heuristic);
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register_dissector("esp", dissect_esp, proto_esp);
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register_dissector("ah", dissect_ah, proto_ah);
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}
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void
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proto_reg_handoff_ipsec(void)
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{
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dissector_handle_t esp_handle, ah_handle, ipcomp_handle;
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data_handle = find_dissector("data");
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ah_handle = find_dissector("ah");
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dissector_add("ip.proto", IP_PROTO_AH, ah_handle);
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esp_handle = find_dissector("esp");
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dissector_add("ip.proto", IP_PROTO_ESP, esp_handle);
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ipcomp_handle = create_dissector_handle(dissect_ipcomp, proto_ipcomp);
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dissector_add("ip.proto", IP_PROTO_IPCOMP, ipcomp_handle);
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ip_dissector_table = find_dissector_table("ip.proto");
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}
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