packet-icap.c

   1 /* packet-icap.c
   2  * Routines for ICAP packet disassembly
   3  *
   4  * Srishylam Simharajan simha@netapp.com
   5  *
   6  * $Id: packet-icap.c,v 1.12 2002/08/28 21:00:17 jmayer Exp $
   7  *
   8  * Ethereal - Network traffic analyzer
   9  * By Gerald Combs <gerald@ethereal.com>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include <string.h>
  32 #include <ctype.h>
  33
  34 #include <glib.h>
  35 #include <epan/packet.h>
  36 #include <epan/strutil.h>
  37
  38 typedef enum _icap_type {
  39         ICAP_OPTIONS,
  40         ICAP_REQMOD,
  41         ICAP_RESPMOD,
  42         ICAP_RESPONSE,
  43         ICAP_OTHER
  44 } icap_type_t;
  45
  46 static int proto_icap = -1;
  47 static int hf_icap_response = -1;
  48 static int hf_icap_reqmod = -1;
  49 static int hf_icap_respmod = -1;
  50 static int hf_icap_options = -1;
  51 static int hf_icap_other = -1;
  52
  53 static gint ett_icap = -1;
  54
  55 static dissector_handle_t data_handle;
  56
  57 #define TCP_PORT_ICAP                   1344
  58 static int is_icap_message(const guchar *data, int linelen, icap_type_t *type);
  59 static void
  60 dissect_icap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  61 {
  62         proto_tree      *icap_tree = NULL;
  63         proto_item      *ti = NULL;
  64         gint            offset = 0;
  65         const guchar    *line;
  66         gint            next_offset;
  67         const guchar    *linep, *lineend;
  68         int             linelen;
  69         guchar          c;
  70         icap_type_t     icap_type;
  71         int             datalen;
  72
  73         if (check_col(pinfo->cinfo, COL_PROTOCOL))
  74                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "ICAP");
  75
  76         if (check_col(pinfo->cinfo, COL_INFO)) {
  77                 /*
  78                  * Put the first line from the buffer into the summary
  79                  * if it's an ICAP header (but leave out the
  80                  * line terminator).
  81                  * Otherwise, just call it a continuation.
  82                  *
  83                  * Note that "tvb_find_line_end()" will return a value that
  84                  * is not longer than what's in the buffer, so the
  85                  * "tvb_get_ptr()" call won't throw an exception.
  86                  */
  87                 linelen = tvb_find_line_end(tvb, offset, -1, &next_offset,
  88                     FALSE);
  89                 line = tvb_get_ptr(tvb, offset, linelen);
  90                 icap_type = ICAP_OTHER; /* type not known yet */
  91                 if (is_icap_message(line, linelen, &icap_type))
  92                         col_add_str(pinfo->cinfo, COL_INFO,
  93                             format_text(line, linelen));
  94                 else
  95                         col_set_str(pinfo->cinfo, COL_INFO, "Continuation");
  96         }
  97
  98         if (tree) {
  99                 ti = proto_tree_add_item(tree, proto_icap, tvb, offset, -1,
 100                     FALSE);
 101                 icap_tree = proto_item_add_subtree(ti, ett_icap);
 102         }
 103
 104         /*
 105          * Process the packet data, a line at a time.
 106          */
 107         icap_type = ICAP_OTHER; /* type not known yet */
 108         while (tvb_offset_exists(tvb, offset)) {
 109                 gboolean is_icap = FALSE;
 110                 gboolean loop_done = FALSE;
 111                 /*
 112                  * Find the end of the line.
 113                  */
 114                 linelen = tvb_find_line_end(tvb, offset, -1, &next_offset,
 115                     FALSE);
 116
 117                 /*
 118                  * Get a buffer that refers to the line.
 119                  */
 120                 line = tvb_get_ptr(tvb, offset, linelen);
 121                 lineend = line + linelen;
 122
 123                 /*
 124                  * find header format
 125                  */
 126                 if (is_icap_message(line, linelen, &icap_type)) {
 127                         is_icap = TRUE;
 128                         goto is_icap_header;
 129                 }
 130
 131                 /*
 132                  * if it looks like a blank line, end of header perhaps?
 133                  */
 134                 if (linelen == 0) {
 135                         is_icap = TRUE;
 136                         goto is_icap_header;
 137                 }
 138
 139                 /*
 140                  * No.  Does it look like a MIME header?
 141                  */
 142                 linep = line;
 143                 loop_done = FALSE;
 144                 while (linep < lineend && (!loop_done)) {
 145                         c = *linep++;
 146                         if (!isprint(c)) {
 147                                 is_icap = FALSE;
 148                                 break;  /* not printable, not a MIME header */
 149                         }
 150                         switch (c) {
 151                         case ':':
 152                                 is_icap = TRUE;
 153                                 goto is_icap_header;
 154                                 break;
 155                         case '(':
 156                         case ')':
 157                         case '<':
 158                         case '>':
 159                         case '@':
 160                         case ',':
 161                         case ';':
 162                         case '\\':
 163                         case '"':
 164                         case '/':
 165                         case '[':
 166                         case ']':
 167                         case '?':
 168                         case '=':
 169                         case '{':
 170                         case '}':
 171                                 is_icap = FALSE;
 172                                 loop_done = TRUE;
 173                                 break;
 174                         }
 175                 }
 176
 177                 /*
 178                  * We don't consider this part of an ICAP message,
 179                  * so we don't display it.
 180                  * (Yeah, that means we don't display, say, a text/icap
 181                  * page, but you can get that from the data pane.)
 182                  */
 183                 if (!is_icap)
 184                         break;
 185 is_icap_header:
 186                 if (tree) {
 187                         proto_tree_add_text(icap_tree, tvb, offset,
 188                                 next_offset - offset, "%s",
 189                                 tvb_format_text(tvb, offset,
 190                                                 next_offset - offset)
 191                                 );
 192                 }
 193                 offset = next_offset;
 194         }
 195
 196         if (tree) {
 197                 switch (icap_type) {
 198
 199                 case ICAP_OPTIONS:
 200                         proto_tree_add_boolean_hidden(icap_tree,
 201                             hf_icap_options, tvb, 0, 0, 1);
 202                         break;
 203
 204                 case ICAP_REQMOD:
 205                         proto_tree_add_boolean_hidden(icap_tree,
 206                             hf_icap_reqmod, tvb, 0, 0, 1);
 207                         break;
 208
 209                 case ICAP_RESPMOD:
 210                         proto_tree_add_boolean_hidden(icap_tree,
 211                             hf_icap_respmod, tvb, 0, 0, 1);
 212                         break;
 213
 214                 case ICAP_RESPONSE:
 215                         proto_tree_add_boolean_hidden(icap_tree,
 216                             hf_icap_response, tvb, 0, 0, 1);
 217                         break;
 218
 219                 case ICAP_OTHER:
 220                 default:
 221                         break;
 222                 }
 223         }
 224
 225         datalen = tvb_length_remaining(tvb, offset);
 226         if (datalen > 0) {
 227                 call_dissector(data_handle,
 228                     tvb_new_subset(tvb, offset, -1, -1), pinfo, icap_tree);
 229         }
 230 }
 231
 232
 233 static int
 234 is_icap_message(const guchar *data, int linelen, icap_type_t *type)
 235 {
 236 #define ICAP_COMPARE(string, length, msgtype) {         \
 237         if (strncmp(data, string, length) == 0) {       \
 238                 if (*type == ICAP_OTHER)                \
 239                         *type = msgtype;                \
 240                 return TRUE;                            \
 241         }                                               \
 242 }
 243         /*
 244          * From draft-elson-opes-icap-01(72).txt
 245          */
 246         if (linelen >= 5) {
 247                 ICAP_COMPARE("ICAP/", 5, ICAP_RESPONSE); /* response */
 248         }
 249         if (linelen >= 7) {
 250                 ICAP_COMPARE("REQMOD ", 7, ICAP_REQMOD); /* request mod */
 251         }
 252         if (linelen >= 8) {
 253                 ICAP_COMPARE("OPTIONS ", 8, ICAP_OPTIONS); /* options */
 254                 ICAP_COMPARE("RESPMOD ", 8, ICAP_RESPMOD); /* response mod */
 255         }
 256         return FALSE;
 257 #undef ICAP_COMPARE
 258 }
 259
 260 void
 261 proto_register_icap(void)
 262 {
 263         static hf_register_info hf[] = {
 264             { &hf_icap_response,
 265               { "Response",             "icap.response",
 266                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 267                 "TRUE if ICAP response", HFILL }},
 268             { &hf_icap_reqmod,
 269               { "Reqmod",               "icap.reqmod",
 270                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 271                 "TRUE if ICAP reqmod", HFILL }},
 272             { &hf_icap_respmod,
 273               { "Respmod",              "icap.respmod",
 274                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 275                 "TRUE if ICAP respmod", HFILL }},
 276             { &hf_icap_options,
 277               { "Options",              "icap.options",
 278                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 279                 "TRUE if ICAP options", HFILL }},
 280             { &hf_icap_other,
 281               { "Other",                "icap.other",
 282                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 283                 "TRUE if ICAP other", HFILL }},
 284         };
 285         static gint *ett[] = {
 286                 &ett_icap,
 287         };
 288
 289         proto_icap = proto_register_protocol(
 290                         "Internet Content Adaptation Protocol",
 291                         "ICAP", "icap");
 292         proto_register_field_array(proto_icap, hf, array_length(hf));
 293         proto_register_subtree_array(ett, array_length(ett));
 294
 295 }
 296
 297 void
 298 proto_reg_handoff_icap(void)
 299 {
 300         dissector_handle_t icap_handle;
 301
 302         data_handle = find_dissector("data");
 303         icap_handle = create_dissector_handle(dissect_icap, proto_icap);
 304         dissector_add("tcp.port", TCP_PORT_ICAP, icap_handle);
 305 }