packet-auto_rp.c

   1 /* packet-auto_rp.c
   2  * Routines for the Cisco Auto-RP protocol
   3  * ftp://ftpeng.cisco.com/ftp/ipmulticast/specs/pim-autorp-spec01.txt
   4  *
   5  * Heikki Vatiainen <hessu@cs.tut.fi>
   6  *
   7  * $Id: packet-auto_rp.c,v 1.13 2001/01/25 06:14:13 guy Exp $
   8  *
   9  * Ethereal - Network traffic analyzer
  10  * By Gerald Combs <gerald@zing.org>
  11  * Copyright 1998 Gerald Combs
  12  *
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  27  */
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #ifdef HAVE_SYS_TYPES_H
  34 # include <sys/types.h>
  35 #endif
  36
  37 #ifdef HAVE_NETINET_IN_H
  38 #include <netinet/in.h>
  39 #endif
  40
  41 #include <string.h>
  42 #include <glib.h>
  43 #include "packet.h"
  44 #include "resolv.h"
  45
  46 static gint proto_auto_rp = -1;
  47 static gint ett_auto_rp = -1;
  48 static gint ett_auto_rp_ver_type = -1;
  49 static gint ett_auto_rp_map = -1;
  50 static gint ett_auto_rp_group = -1;
  51
  52 static gint hf_auto_rp_version = -1;
  53 static gint hf_auto_rp_type = -1;
  54 static gint hf_auto_rp_count = -1;
  55 static gint hf_auto_rp_holdtime = -1;
  56 static gint hf_auto_rp_pim_ver = -1;
  57 static gint hf_auto_rp_rp_addr = -1;
  58 static gint hf_auto_rp_prefix_sgn = -1;
  59 static gint hf_auto_rp_mask_len = -1;
  60 static gint hf_auto_rp_group_prefix = -1;
  61
  62 #define UDP_PORT_PIM_RP_DISC 496
  63
  64 struct auto_rp_fixed_hdr {
  65 #define AUTO_RP_VERSION_MASK 0xf0
  66 #define AUTO_RP_TYPE_MASK    0x0f
  67         guint8  ver_type;       /* pim-autorp-spec01.txt defines version 1+ */
  68         guint8  rp_count;       /* Number of struct auto_rp_maps that follow the this header */
  69         guint16 holdtime;       /* Time in seconds this announcement is valid. 0 equals forever */
  70         guint32 reserved;
  71 };
  72
  73 struct auto_rp_map_hdr {
  74         guint32 rp_address;       /* The unicast IPv4 address of this RP */
  75 #define AUTO_RP_PIM_VER_MASK 0x03
  76         guint8  pim_version;      /* RP's highest PIM version. 2-bit field */
  77         guint8  group_count;      /* Number of encoded group addresses that follow this header */
  78 };
  79
  80 struct auto_rp_enc_grp_hdr {   /* Encoded group address */
  81 #define AUTO_RP_SIGN_MASK 0x01
  82         guint8  prefix_sgn;    /* 0 positive, 1 negative group prefix */
  83         guint8  mask_len;      /* Length of group prefix */
  84         guint32 addr;          /* Group prefix */
  85 };
  86
  87 #define AUTO_RP_VER_1PLUS 1
  88 static const value_string auto_rp_ver_vals[] = {
  89         {AUTO_RP_VER_1PLUS, "1 or 1+"},
  90         {0,                 NULL}
  91 };
  92
  93 #define AUTO_RP_TYPE_ANNOUNCEMENT 1
  94 #define AUTO_RP_TYPE_MAPPING      2
  95 static const value_string auto_rp_type_vals[] = {
  96         {AUTO_RP_TYPE_ANNOUNCEMENT, "RP announcement"},
  97         {AUTO_RP_TYPE_MAPPING,      "RP mapping"},
  98         {0,                         NULL}
  99 };
 100
 101 #define AUTO_RP_PIM_VERSION_UNKNOWN 0x00
 102 #define AUTO_RP_PIM_VERSION_1       0x01
 103 #define AUTO_RP_PIM_VERSION_2       0x02
 104 #define AUTO_RP_PIM_VERSION_DUAL    0x03
 105 static const value_string auto_rp_pim_ver_vals[] = {
 106         {AUTO_RP_PIM_VERSION_UNKNOWN, "Version unknown"},
 107         {AUTO_RP_PIM_VERSION_1,       "Version 1"},
 108         {AUTO_RP_PIM_VERSION_2,       "Version 2"},
 109         {AUTO_RP_PIM_VERSION_DUAL,    "Dual version 1 and 2"},
 110         {0,                           NULL}
 111 };
 112
 113 #define AUTO_RP_GROUP_MASK_SIGN_POS 0
 114 #define AUTO_RP_GROUP_MASK_SIGN_NEG 1
 115 static const value_string auto_rp_mask_sign_vals[] = {
 116         {AUTO_RP_GROUP_MASK_SIGN_POS,  "Positive group prefix"},
 117         {AUTO_RP_GROUP_MASK_SIGN_NEG,  "Negative group prefix"},
 118         {0,                            NULL}
 119 };
 120
 121 static int do_auto_rp_map(tvbuff_t *tvb, int offset, proto_tree *auto_rp_tree);
 122
 123 static void dissect_auto_rp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 124 {
 125         guint8 ver_type, rp_count;
 126
 127         if (check_col(pinfo->fd, COL_PROTOCOL))
 128                 col_set_str(pinfo->fd, COL_PROTOCOL, "Auto-RP");
 129         if (check_col(pinfo->fd, COL_INFO))
 130                 col_clear(pinfo->fd, COL_INFO);
 131
 132         ver_type = tvb_get_guint8(tvb, 0);
 133         rp_count = tvb_get_guint8(tvb, 1);
 134         if (check_col(pinfo->fd, COL_INFO))
 135                 col_add_fstr(pinfo->fd, COL_INFO, "%s (v%s) for %u RP%s",
 136                              val_to_str(lo_nibble(ver_type), auto_rp_type_vals, "Unknown"),
 137                              val_to_str(hi_nibble(ver_type), auto_rp_ver_vals, "Unknown"),
 138                              rp_count, plurality(rp_count, "", "s"));
 139
 140         if (tree) {
 141                 proto_item *ti, *tv;
 142                 proto_tree *auto_rp_tree, *ver_type_tree;
 143                 int i, offset;
 144                 guint16 holdtime;
 145
 146                 offset = 0;
 147                 ti = proto_tree_add_item(tree, proto_auto_rp, tvb, offset, tvb_length(tvb), FALSE);
 148                 auto_rp_tree = proto_item_add_subtree(ti, ett_auto_rp);
 149
 150                 tv = proto_tree_add_text(auto_rp_tree, tvb, offset, 1, "Version: %s, Packet type: %s",
 151                                          val_to_str(hi_nibble(ver_type), auto_rp_ver_vals, "Unknown"),
 152                                          val_to_str(lo_nibble(ver_type), auto_rp_type_vals, "Unknown"));
 153                 ver_type_tree = proto_item_add_subtree(tv, ett_auto_rp_ver_type);
 154                 proto_tree_add_uint(ver_type_tree, hf_auto_rp_version, tvb, offset, 1, ver_type);
 155                 proto_tree_add_uint(ver_type_tree, hf_auto_rp_type, tvb, offset, 1, ver_type);
 156                 offset++;
 157
 158                 proto_tree_add_uint(auto_rp_tree, hf_auto_rp_count, tvb, offset, 1, rp_count);
 159                 offset++;
 160
 161                 holdtime = tvb_get_ntohs(tvb, offset);
 162                 proto_tree_add_uint_format(auto_rp_tree, hf_auto_rp_holdtime, tvb, offset, 2, holdtime,
 163                                            "Holdtime: %u second%s", holdtime, plurality(holdtime, "", "s"));
 164                 offset+=2;
 165
 166                 proto_tree_add_text(auto_rp_tree, tvb, offset, 4, "Reserved: 0x%x", tvb_get_ntohs(tvb, offset));
 167                 offset+=4;
 168
 169                 for (i = 0; i < rp_count; i++)
 170                         offset = do_auto_rp_map(tvb, offset, auto_rp_tree);
 171
 172                 if (tvb_length_remaining(tvb, offset) > 0)
 173                         proto_tree_add_text(tree, tvb, offset, tvb_length_remaining(tvb, offset), "Trailing junk");
 174         }
 175
 176         return;
 177 }
 178
 179 void proto_register_auto_rp(void)
 180 {
 181         static hf_register_info hf[] = {
 182                 { &hf_auto_rp_version,
 183                   {"Protocol version", "auto_rp.version",
 184                    FT_UINT8, BASE_DEC, VALS(auto_rp_ver_vals), AUTO_RP_VERSION_MASK,
 185                    "Auto-RP protocol version"}},
 186
 187                 { &hf_auto_rp_type,
 188                   {"Packet type", "auto_rp.type",
 189                    FT_UINT8, BASE_DEC, VALS(auto_rp_type_vals), AUTO_RP_TYPE_MASK,
 190                    "Auto-RP packet type"}},
 191
 192                 { &hf_auto_rp_count,
 193                   {"RP count", "auto_rp.rp_count",
 194                    FT_UINT8, BASE_DEC, NULL, 0,
 195                    "The number of RP addresses contained in this message"}},
 196
 197                 { &hf_auto_rp_holdtime,
 198                   {"Holdtime", "auto_rp.holdtime",
 199                    FT_UINT16, BASE_DEC, NULL, 0,
 200                    "The amount of time in seconds this announcement is valid"}},
 201
 202                 { &hf_auto_rp_pim_ver,
 203                   {"Version", "auto_rp.pim_ver",
 204                    FT_UINT8, BASE_DEC, VALS(auto_rp_pim_ver_vals), AUTO_RP_PIM_VER_MASK,
 205                    "RP's highest PIM version"}},
 206
 207                 { &hf_auto_rp_rp_addr,
 208                   {"RP address", "auto_rp.rp_addr",
 209                    FT_IPv4, 0, NULL, 0,
 210                    "The unicast IP address of the RP"}},
 211
 212                 { &hf_auto_rp_prefix_sgn,
 213                   {"Sign", "auto_rp.prefix_sign",
 214                    FT_UINT8, BASE_DEC, VALS(auto_rp_mask_sign_vals), AUTO_RP_SIGN_MASK,
 215                    "Group prefix sign"}},
 216
 217                 { &hf_auto_rp_mask_len,
 218                   {"Mask length", "auto_rp.mask_len",
 219                    FT_UINT8, BASE_BIN, NULL, 0x0,
 220                    "Length of group prefix"}},
 221
 222                 { &hf_auto_rp_group_prefix,
 223                   {"Prefix", "auto_rp.group_prefix",
 224                    FT_IPv4, 0, NULL, 0,
 225                    "Group prefix"}}
 226         };
 227
 228         static gint *ett[] = {
 229                 &ett_auto_rp,
 230                 &ett_auto_rp_ver_type,
 231                 &ett_auto_rp_map,
 232                 &ett_auto_rp_group
 233         };
 234
 235         proto_auto_rp = proto_register_protocol("Cisco Auto-RP",
 236             "Auto-RP", "auto_rp");
 237         proto_register_field_array(proto_auto_rp, hf, array_length(hf));
 238         proto_register_subtree_array(ett, array_length(ett));
 239
 240         return;
 241 }
 242
 243 void
 244 proto_reg_handoff_auto_rp(void)
 245 {
 246         dissector_add("udp.port", UDP_PORT_PIM_RP_DISC, dissect_auto_rp,
 247             proto_auto_rp);
 248 }
 249
 250 /*
 251  * Handles one Auto-RP map entry. Returns the new offset.
 252  */
 253 static int do_auto_rp_map(tvbuff_t *tvb, int offset, proto_tree *auto_rp_tree)
 254 {
 255         proto_item *ti;
 256         proto_tree *map_tree;
 257         guint8 group_count;
 258         guint32 rp_addr;      /* In network byte order */
 259         int i;
 260
 261         tvb_memcpy(tvb, (guint8 *)&rp_addr, offset, 4);
 262         group_count = tvb_get_guint8(tvb, offset + 5);
 263
 264                                /* sizeof map header + n * sizeof encoded group addresses */
 265         ti = proto_tree_add_text(auto_rp_tree, tvb, offset, 6 + group_count * 6,
 266                                  "RP %s: %u group%s", ip_to_str((void *)&rp_addr),
 267                                  group_count, plurality(group_count, "", "s"));
 268         map_tree = proto_item_add_subtree(ti, ett_auto_rp_map);
 269
 270         proto_tree_add_ipv4(map_tree, hf_auto_rp_rp_addr, tvb, offset, 4, rp_addr);
 271         offset += 4;
 272         proto_tree_add_uint(map_tree, hf_auto_rp_pim_ver, tvb, offset, 1, tvb_get_guint8(tvb, offset));
 273         offset++;
 274         proto_tree_add_text(map_tree, tvb, offset, 1, "Number of groups this RP maps to: %u", group_count);
 275         offset++;
 276
 277         for (i = 0; i < group_count; i++) {
 278                 proto_item *gi;
 279                 proto_tree *grp_tree;
 280                 guint8 sign, mask_len;
 281                 guint32 group_addr;     /* In network byte order */
 282
 283                 sign = tvb_get_guint8(tvb, offset);
 284                 mask_len = tvb_get_guint8(tvb, offset + 1);
 285                 tvb_memcpy(tvb, (guint8 *)&group_addr, offset + 2, 4);
 286                 gi = proto_tree_add_text(map_tree, tvb, offset, 6, "Group %s/%u (%s)",
 287                                          ip_to_str((void *)&group_addr), mask_len,
 288                                          val_to_str(sign&AUTO_RP_SIGN_MASK, auto_rp_mask_sign_vals, ""));
 289                 grp_tree = proto_item_add_subtree(gi, ett_auto_rp_group);
 290
 291                 proto_tree_add_uint(grp_tree, hf_auto_rp_prefix_sgn, tvb, offset, 1, sign);
 292                 offset++;
 293                 proto_tree_add_uint(grp_tree, hf_auto_rp_mask_len, tvb, offset, 1, mask_len);
 294                 offset++;
 295                 proto_tree_add_ipv4(grp_tree, hf_auto_rp_group_prefix, tvb, offset, 4, group_addr);
 296                 offset += 4;
 297
 298         }
 299
 300         return offset;
 301 }