epan/dissectors/packet-banana.c

   1 /* packet-bananna.c
   2  * Routines for the Twisted Banana serialization protocol dissection
   3  * Copyright 2009, Gerald Combs <gerald@wireshark.org>
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  24  */
  25
  26 /*
  27  * Based on "Banana Protocol Specifications"
  28  * http://twistedmatrix.com/projects/core/documentation/specifications/banana.html
  29  */
  30
  31 #include "config.h"
  32
  33 #include <glib.h>
  34
  35 #include <epan/packet.h>
  36 #include <epan/prefs.h>
  37 #include <epan/expert.h>
  38
  39 void proto_register_banana(void);
  40 void proto_reg_handoff_banana(void);
  41
  42 /* Initialize the protocol and registered fields */
  43 static int proto_banana = -1;
  44 static int hf_banana_list = -1;
  45 static int hf_banana_int = -1;
  46 static int hf_banana_string = -1;
  47 static int hf_banana_neg_int = -1;
  48 static int hf_banana_float = -1;
  49 static int hf_banana_lg_int = -1;
  50 static int hf_banana_lg_neg_int = -1;
  51 static int hf_banana_pb = -1;
  52
  53 /* Initialize the subtree pointers */
  54 static gint ett_banana = -1;
  55 static gint ett_list = -1;
  56
  57 static expert_field ei_banana_unknown_type = EI_INIT;
  58 static expert_field ei_banana_too_many_value_bytes = EI_INIT;
  59 static expert_field ei_banana_length_too_long = EI_INIT;
  60 static expert_field ei_banana_value_too_large = EI_INIT;
  61 static expert_field ei_banana_pb_error = EI_INIT;
  62
  63 static dissector_handle_t banana_handle;
  64
  65 #define BE_LIST         0x80
  66 #define BE_INT          0x81
  67 #define BE_STRING       0x82
  68 #define BE_NEG_INT      0x83
  69 #define BE_FLOAT        0x84
  70 #define BE_LG_INT       0x85
  71 #define BE_LG_NEG_INT   0x86
  72 #define BE_PB           0x87
  73
  74 #define is_element(b) (b >= BE_LIST && b <= BE_PB)
  75
  76 static const value_string type_vals[] = {
  77     { BE_LIST,          "List" },
  78     { BE_INT,           "Integer" },
  79     { BE_STRING,        "String" },
  80     { BE_NEG_INT,       "Negative Integer" },
  81     { BE_FLOAT,         "Float" },
  82     { BE_LG_INT,        "Large Integer" },
  83     { BE_LG_NEG_INT,    "Large Negative Integer" },
  84     { BE_PB,            "pb Profile"},
  85     { 0, NULL }
  86 };
  87
  88 static const value_string pb_vals[] = {
  89     { 0x01, "None" },
  90     { 0x02, "class" },
  91     { 0x03, "dereference" },
  92     { 0x04, "reference" },
  93     { 0x05, "dictionary" },
  94     { 0x06, "function" },
  95     { 0x07, "instance" },
  96     { 0x08, "list" },
  97     { 0x09, "module" },
  98     { 0x0a, "persistent" },
  99     { 0x0b, "tuple" },
 100     { 0x0c, "unpersistable" },
 101     { 0x0d, "copy" },
 102     { 0x0e, "cache" },
 103     { 0x0f, "cached" },
 104     { 0x10, "remote" },
 105     { 0x11, "local" },
 106     { 0x12, "lcache" },
 107     { 0x13, "version" },
 108     { 0x14, "login" },
 109     { 0x15, "password" },
 110     { 0x16, "challenge" },
 111     { 0x17, "logged_in" },
 112     { 0x18, "not_logged_in" },
 113     { 0x19, "cachemessage" },
 114     { 0x1a, "message" },
 115     { 0x1b, "answer" },
 116     { 0x1c, "error" },
 117     { 0x1d, "decref" },
 118     { 0x1e, "decache" },
 119     { 0x1f, "uncache" },
 120     { 0,    NULL }
 121 };
 122
 123 #define MAX_ELEMENT_VAL 2147483647 /* Max TE value */
 124 #define MAX_ELEMENT_INT_LEN 4
 125 #define MAX_ELEMENT_VAL_LEN 8
 126
 127 static range_t *global_banana_tcp_range = NULL;
 128 static range_t *banana_tcp_range = NULL;
 129
 130 /* Dissect the packets */
 131
 132 static int
 133 dissect_banana_element(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset) {
 134     proto_item *ti;
 135     proto_tree *list_tree;
 136     guint8 byte = 0;
 137     gint64 val = 0;
 138     gint val_len = 0;
 139     int start_offset = offset;
 140     int old_offset;
 141     int i;
 142
 143     /* Accumulate our value/length 'til we hit a valid type */
 144     while (tvb_length_remaining(tvb, offset) > 0) {
 145         byte = tvb_get_guint8(tvb, offset);
 146         offset++;
 147
 148         if (byte & 0x80) {
 149             if (is_element(byte)) {
 150                 break;
 151             } else {
 152                 expert_add_info_format(pinfo, NULL, &ei_banana_unknown_type, "Unknown type %u", byte);
 153             }
 154         } else {
 155             val_len++;
 156             if (val_len > MAX_ELEMENT_VAL_LEN) {
 157                 expert_add_info(pinfo, NULL, &ei_banana_too_many_value_bytes);
 158             }
 159             val += byte + (val << 7);
 160         }
 161     }
 162
 163     /* Type */
 164     switch (byte) {
 165         case BE_LIST:
 166             if (val > MAX_ELEMENT_VAL) {
 167                 expert_add_info_format(pinfo, NULL, &ei_banana_length_too_long, "List length %" G_GINT64_MODIFIER "d longer than we can handle", val);
 168             }
 169             ti = proto_tree_add_uint_format_value(tree, hf_banana_list, tvb, start_offset, offset - start_offset - 1, (guint32) val, "(%d items)", (gint) val);
 170             list_tree = proto_item_add_subtree(ti, ett_list);
 171             for (i = 0; i < val; i++) {
 172                 old_offset = offset;
 173                 offset += dissect_banana_element(tvb, pinfo, list_tree, offset);
 174                 if (offset <= old_offset) {
 175                     return offset - start_offset;
 176                 }
 177             }
 178             break;
 179         case BE_INT:
 180             if (val > MAX_ELEMENT_VAL) {
 181                 expert_add_info_format(pinfo, NULL, &ei_banana_value_too_large, "Integer value %" G_GINT64_MODIFIER "d too large", val);
 182             }
 183             proto_tree_add_uint(tree, hf_banana_int, tvb, start_offset, offset - start_offset, (guint32) val);
 184             break;
 185         case BE_STRING:
 186             if (val > MAX_ELEMENT_VAL) {
 187                 expert_add_info_format(pinfo, NULL, &ei_banana_length_too_long, "String length %" G_GINT64_MODIFIER "d longer than we can handle", val);
 188             }
 189             proto_tree_add_item(tree, hf_banana_string, tvb, offset, (guint32) val, ENC_ASCII|ENC_NA);
 190             offset += (gint) val;
 191             break;
 192         case BE_NEG_INT:
 193             if (val > MAX_ELEMENT_VAL) {
 194                 expert_add_info_format(pinfo, NULL, &ei_banana_value_too_large, "Integer value -%" G_GINT64_MODIFIER "d too large", val);
 195             }
 196             proto_tree_add_int(tree, hf_banana_neg_int, tvb, start_offset, offset - start_offset, (gint32) val * -1);
 197             break;
 198         case BE_FLOAT:
 199             proto_tree_add_item(tree, hf_banana_float, tvb, offset, 8, ENC_BIG_ENDIAN);
 200             offset += 8;
 201             break;
 202         case BE_LG_INT:
 203             proto_tree_add_item(tree, hf_banana_lg_int, tvb, start_offset, offset - start_offset, ENC_NA);
 204             break;
 205         case BE_LG_NEG_INT:
 206             proto_tree_add_item(tree, hf_banana_lg_neg_int, tvb, start_offset, offset - start_offset, ENC_NA);
 207             break;
 208         case BE_PB:
 209             if (val_len > 1) {
 210                 expert_add_info(pinfo, NULL, &ei_banana_pb_error);
 211             }
 212             /*
 213              * The spec says the pb dictionary value comes after the tag.
 214              * In real-world captures it comes before.
 215              */
 216             proto_tree_add_item(tree, hf_banana_pb, tvb, offset - 2, 1, ENC_BIG_ENDIAN);
 217             break;
 218         default:
 219             return 0;
 220             break;
 221     }
 222     return offset - start_offset;
 223 }
 224
 225 static int
 226 dissect_banana(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
 227     guint8 byte = 0;
 228     gint offset = 0, old_offset;
 229     proto_item *ti;
 230     proto_tree *banana_tree;
 231
 232     /* Check that there's enough data */
 233     if (tvb_length(tvb) < 2)
 234         return 0;
 235
 236     /* Fill in our protocol and info columns */
 237     col_set_str(pinfo->cinfo, COL_PROTOCOL, "Banana");
 238
 239     while (tvb_length_remaining(tvb, offset) > 0 && offset < MAX_ELEMENT_VAL_LEN) {
 240         byte = tvb_get_guint8(tvb, offset);
 241         if (is_element(byte))
 242             break;
 243         offset++;
 244     }
 245     col_add_fstr(pinfo->cinfo, COL_INFO, "First element: %s",
 246         val_to_str(byte, type_vals, "Unknown type: %u"));
 247
 248     /* Create display subtree for the protocol */
 249     ti = proto_tree_add_item(tree, proto_banana, tvb, 0, -1, ENC_NA);
 250     banana_tree = proto_item_add_subtree(ti, ett_banana);
 251
 252     offset = 0;
 253     old_offset = -1;
 254     while (offset > old_offset) {
 255         old_offset = offset;
 256         offset += dissect_banana_element(tvb, pinfo, banana_tree, offset);
 257     }
 258
 259     /* Return the amount of data this dissector was able to dissect */
 260     return tvb_length(tvb);
 261 }
 262
 263 static void
 264 banana_prefs(void) {
 265     dissector_delete_uint_range("tcp.port", banana_tcp_range, banana_handle);
 266     g_free(banana_tcp_range);
 267     banana_tcp_range = range_copy(global_banana_tcp_range);
 268     dissector_add_uint_range("tcp.port", banana_tcp_range, banana_handle);
 269 }
 270
 271 /* Register the protocol with Wireshark */
 272
 273 void
 274 proto_register_banana(void)
 275 {
 276     static hf_register_info hf[] = {
 277         { &hf_banana_list,
 278             { "List Length", "banana.list",
 279                 FT_UINT32, BASE_DEC, NULL, 0,
 280                 "Banana list", HFILL }
 281         },
 282         { &hf_banana_int,
 283             { "Integer", "banana.int",
 284                 FT_UINT32, BASE_DEC, NULL, 0,
 285                 "Banana integer", HFILL }
 286         },
 287         { &hf_banana_string,
 288             { "String", "banana.string",
 289                 FT_STRING, BASE_NONE, NULL, 0,
 290                 "Banana string", HFILL }
 291         },
 292         { &hf_banana_neg_int,
 293             { "Negative Integer", "banana.neg_int",
 294                 FT_INT32, BASE_DEC, NULL, 0,
 295                 "Banana negative integer", HFILL }
 296         },
 297         { &hf_banana_float,
 298             { "Float", "banana.float",
 299                 FT_DOUBLE, BASE_NONE, NULL, 0,
 300                 "Banana float", HFILL }
 301         },
 302         { &hf_banana_lg_int,
 303             { "Float", "banana.lg_int",
 304                 FT_BYTES, BASE_NONE, NULL, 0,
 305                 "Banana large integer", HFILL }
 306         },
 307         { &hf_banana_lg_neg_int,
 308             { "Float", "banana.lg_neg_int",
 309                 FT_BYTES, BASE_NONE, NULL, 0,
 310                 "Banana large negative integer", HFILL }
 311         },
 312         { &hf_banana_pb,
 313             { "pb Profile Value", "banana.pb",
 314                 FT_UINT8, BASE_HEX, VALS(pb_vals), 0,
 315                 "Banana Perspective Broker Profile Value", HFILL }
 316         }
 317     };
 318
 319     module_t *banana_module;
 320     expert_module_t* expert_banana;
 321
 322     /* Setup protocol subtree array */
 323     static gint *ett[] = {
 324         &ett_banana,
 325         &ett_list
 326     };
 327
 328     static ei_register_info ei[] = {
 329         { &ei_banana_unknown_type, { "banana.unknown_type", PI_UNDECODED, PI_ERROR, "Unknown type", EXPFILL }},
 330         { &ei_banana_too_many_value_bytes, { "banana.too_many_value_bytes", PI_UNDECODED, PI_ERROR, "Too many value/length bytes", EXPFILL }},
 331         { &ei_banana_length_too_long, { "banana.length_too_long", PI_UNDECODED, PI_ERROR, "Length too long", EXPFILL }},
 332         { &ei_banana_value_too_large, { "banana.value_too_large", PI_MALFORMED, PI_ERROR, "Value too large", EXPFILL }},
 333         { &ei_banana_pb_error, { "banana.pb_error", PI_MALFORMED, PI_ERROR, "More than 1 byte before pb", EXPFILL }},
 334     };
 335
 336     /* Register the protocol name and description */
 337     proto_banana = proto_register_protocol("Twisted Banana", "Banana", "banana");
 338
 339     /* Required function calls to register the header fields and subtrees used */
 340     proto_register_field_array(proto_banana, hf, array_length(hf));
 341     proto_register_subtree_array(ett, array_length(ett));
 342     expert_banana = expert_register_protocol(proto_banana);
 343     expert_register_field_array(expert_banana, ei, array_length(ei));
 344
 345     /* Initialize dissector preferences */
 346     banana_module = prefs_register_protocol(proto_banana, banana_prefs);
 347     banana_tcp_range = range_empty();
 348     prefs_register_range_preference(banana_module, "tcp.port", "TCP Ports", "Banana TCP Port range", &global_banana_tcp_range, 65535);
 349 }
 350
 351 void
 352 proto_reg_handoff_banana(void)
 353 {
 354     banana_handle = new_create_dissector_handle(dissect_banana, proto_banana);
 355 }
 356
 357 /*
 358  * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 359  *
 360  * Local variables:
 361  * c-basic-offset: 4
 362  * tab-width: 8
 363  * indent-tabs-mode: nil
 364  * End:
 365  *
 366  * ex: set shiftwidth=4 tabstop=8 expandtab:
 367  * :indentSize=4:tabSize=8:noTabs=true:
 368  */
 369
 370