packet-icap.c

   1 /* packet-icap.c
   2  * Routines for ICAP packet disassembly
   3  *
   4  * Srishylam Simharajan simha@netapp.com
   5  *
   6  * packet-icap.c Mon Aug 13 17:50:19 PDT 2001 simha
   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 #ifdef HAVE_SYS_TYPES_H
  32 #include <sys/types.h>
  33 #endif
  34
  35 #include <string.h>
  36 #include <ctype.h>
  37
  38 #include <glib.h>
  39 #include <epan/packet.h>
  40 #include <epan/strutil.h>
  41
  42 typedef enum _icap_type {
  43         ICAP_OPTIONS,
  44         ICAP_REQMOD,
  45         ICAP_RESPMOD,
  46         ICAP_RESPONSE,
  47         ICAP_OTHER
  48 } icap_type_t;
  49
  50 static int proto_icap = -1;
  51 static int hf_icap_response = -1;
  52 static int hf_icap_reqmod = -1;
  53 static int hf_icap_respmod = -1;
  54 static int hf_icap_options = -1;
  55 static int hf_icap_other = -1;
  56
  57 static gint ett_icap = -1;
  58
  59 static dissector_handle_t data_handle;
  60
  61 #define TCP_PORT_ICAP                   1344
  62 static int is_icap_message(const u_char *data, int linelen, icap_type_t *type);
  63 static void
  64 dissect_icap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  65 {
  66         proto_tree      *icap_tree = NULL;
  67         proto_item      *ti = NULL;
  68         gint            offset = 0;
  69         const u_char    *line;
  70         gint            next_offset;
  71         const u_char    *linep, *lineend;
  72         int             linelen;
  73         u_char          c;
  74         icap_type_t     icap_type;
  75         int             datalen;
  76
  77         if (check_col(pinfo->cinfo, COL_PROTOCOL))
  78                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "ICAP");
  79
  80         if (check_col(pinfo->cinfo, COL_INFO)) {
  81                 /*
  82                  * Put the first line from the buffer into the summary
  83                  * if it's an ICAP header (but leave out the
  84                  * line terminator).
  85                  * Otherwise, just call it a continuation.
  86                  *
  87                  * Note that "tvb_find_line_end()" will return a value that
  88                  * is not longer than what's in the buffer, so the
  89                  * "tvb_get_ptr()" call won't throw an exception.
  90                  */
  91                 linelen = tvb_find_line_end(tvb, offset, -1, &next_offset);
  92                 line = tvb_get_ptr(tvb, offset, linelen);
  93                 icap_type = ICAP_OTHER; /* type not known yet */
  94                 if (is_icap_message(line, linelen, &icap_type))
  95                         col_add_str(pinfo->cinfo, COL_INFO,
  96                             format_text(line, linelen));
  97                 else
  98                         col_set_str(pinfo->cinfo, COL_INFO, "Continuation");
  99         }
 100
 101         if (tree) {
 102                 ti = proto_tree_add_item(tree, proto_icap, tvb, offset, -1,
 103                     FALSE);
 104                 icap_tree = proto_item_add_subtree(ti, ett_icap);
 105         }
 106
 107         /*
 108          * Process the packet data, a line at a time.
 109          */
 110         icap_type = ICAP_OTHER; /* type not known yet */
 111         while (tvb_offset_exists(tvb, offset)) {
 112                 gboolean is_icap = FALSE;
 113                 gboolean loop_done = FALSE;
 114                 /*
 115                  * Find the end of the line.
 116                  */
 117                 linelen = tvb_find_line_end(tvb, offset, -1, &next_offset);
 118
 119                 /*
 120                  * Get a buffer that refers to the line.
 121                  */
 122                 line = tvb_get_ptr(tvb, offset, linelen);
 123                 lineend = line + linelen;
 124
 125                 /*
 126                  * find header format
 127                  */
 128                 if (is_icap_message(line, linelen, &icap_type)) {
 129                         is_icap = TRUE;
 130                         goto is_icap_header;
 131                 }
 132
 133                 /*
 134                  * if it looks like a blank line, end of header perhaps?
 135                  */
 136                 if (linelen == 0) {
 137                         is_icap = TRUE;
 138                         goto is_icap_header;
 139                 }
 140
 141                 /*
 142                  * No.  Does it look like a MIME header?
 143                  */
 144                 linep = line;
 145                 loop_done = FALSE;
 146                 while (linep < lineend && (!loop_done)) {
 147                         c = *linep++;
 148                         if (!isprint(c)) {
 149                                 is_icap = FALSE;
 150                                 break;  /* not printable, not a MIME header */
 151                         }
 152                         switch (c) {
 153                         case ':':
 154                                 is_icap = TRUE;
 155                                 goto is_icap_header;
 156                                 break;
 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                         case '{':
 172                         case '}':
 173                                 is_icap = FALSE;
 174                                 loop_done = TRUE;
 175                                 break;
 176                         }
 177                 }
 178
 179                 /*
 180                  * We don't consider this part of an ICAP message,
 181                  * so we don't display it.
 182                  * (Yeah, that means we don't display, say, a text/icap
 183                  * page, but you can get that from the data pane.)
 184                  */
 185                 if (!is_icap)
 186                         break;
 187 is_icap_header:
 188                 if (tree) {
 189                         proto_tree_add_text(icap_tree, tvb, offset,
 190                                 next_offset - offset, "%s",
 191                                 tvb_format_text(tvb, offset,
 192                                                 next_offset - offset)
 193                                 );
 194                 }
 195                 offset = next_offset;
 196         }
 197
 198         if (tree) {
 199                 switch (icap_type) {
 200
 201                 case ICAP_OPTIONS:
 202                         proto_tree_add_boolean_hidden(icap_tree,
 203                             hf_icap_options, tvb, 0, 0, 1);
 204                         break;
 205
 206                 case ICAP_REQMOD:
 207                         proto_tree_add_boolean_hidden(icap_tree,
 208                             hf_icap_reqmod, tvb, 0, 0, 1);
 209                         break;
 210
 211                 case ICAP_RESPMOD:
 212                         proto_tree_add_boolean_hidden(icap_tree,
 213                             hf_icap_respmod, tvb, 0, 0, 1);
 214                         break;
 215
 216                 case ICAP_RESPONSE:
 217                         proto_tree_add_boolean_hidden(icap_tree,
 218                             hf_icap_response, tvb, 0, 0, 1);
 219                         break;
 220
 221                 case ICAP_OTHER:
 222                 default:
 223                         break;
 224                 }
 225         }
 226
 227         datalen = tvb_length_remaining(tvb, offset);
 228         if (datalen > 0) {
 229                 call_dissector(data_handle,tvb_new_subset(tvb, offset, -1, tvb_reported_length_remaining(tvb,offset)), pinfo, icap_tree);
 230         }
 231 }
 232
 233
 234 static int
 235 is_icap_message(const u_char *data, int linelen, icap_type_t *type)
 236 {
 237 #define ICAP_COMPARE(string, length, msgtype) {         \
 238         if (strncmp(data, string, length) == 0) {       \
 239                 if (*type == ICAP_OTHER)                \
 240                         *type = msgtype;                \
 241                 return TRUE;                            \
 242         }                                               \
 243 }
 244         /*
 245          * From draft-elson-opes-icap-01(72).txt
 246          */
 247         if (linelen >= 5) {
 248                 ICAP_COMPARE("ICAP/", 5, ICAP_RESPONSE); /* response */
 249         }
 250         if (linelen >= 7) {
 251                 ICAP_COMPARE("REQMOD ", 7, ICAP_REQMOD); /* request mod */
 252         }
 253         if (linelen >= 8) {
 254                 ICAP_COMPARE("OPTIONS ", 8, ICAP_OPTIONS); /* options */
 255                 ICAP_COMPARE("RESPMOD ", 8, ICAP_RESPMOD); /* response mod */
 256         }
 257         return FALSE;
 258 #undef ICAP_COMPARE
 259 }
 260
 261 void
 262 proto_register_icap(void)
 263 {
 264         static hf_register_info hf[] = {
 265             { &hf_icap_response,
 266               { "Response",             "icap.response",
 267                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 268                 "TRUE if ICAP response", HFILL }},
 269             { &hf_icap_reqmod,
 270               { "Reqmod",               "icap.reqmod",
 271                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 272                 "TRUE if ICAP reqmod", HFILL }},
 273             { &hf_icap_respmod,
 274               { "Respmod",              "icap.respmod",
 275                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 276                 "TRUE if ICAP respmod", HFILL }},
 277             { &hf_icap_options,
 278               { "Options",              "icap.options",
 279                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 280                 "TRUE if ICAP options", HFILL }},
 281             { &hf_icap_other,
 282               { "Other",                "icap.other",
 283                 FT_BOOLEAN, BASE_NONE, NULL, 0x0,
 284                 "TRUE if ICAP other", HFILL }},
 285         };
 286         static gint *ett[] = {
 287                 &ett_icap,
 288         };
 289
 290         proto_icap = proto_register_protocol(
 291                         "Internet Content Adaptation Protocol",
 292                         "ICAP", "icap");
 293         proto_register_field_array(proto_icap, hf, array_length(hf));
 294         proto_register_subtree_array(ett, array_length(ett));
 295
 296 }
 297
 298 void
 299 proto_reg_handoff_icap(void)
 300 {
 301         dissector_handle_t icap_handle;
 302
 303         data_handle = find_dissector("data");
 304         icap_handle = create_dissector_handle(dissect_icap, proto_icap);
 305         dissector_add("tcp.port", TCP_PORT_ICAP, icap_handle);
 306 }