/* packet-auto_rp.c * Routines for the Cisco Auto-RP protocol * ftp://ftpeng.cisco.com/ftp/ipmulticast/specs/pim-autorp-spec01.txt * * Heikki Vatiainen * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include #include void proto_register_auto_rp(void); void proto_reg_handoff_auto_rp(void); static dissector_handle_t auto_rp_handle; static gint proto_auto_rp; static gint ett_auto_rp; static gint ett_auto_rp_ver_type; static gint ett_auto_rp_map; static gint ett_auto_rp_group; static gint hf_auto_rp_version; static gint hf_auto_rp_type; static gint hf_auto_rp_count; static gint hf_auto_rp_holdtime; static gint hf_auto_rp_pim_ver; static gint hf_auto_rp_rp_addr; static gint hf_auto_rp_prefix_sgn; static gint hf_auto_rp_mask_len; static gint hf_auto_rp_group_prefix; static gint hf_auto_rp_reserved; static gint hf_auto_rp_trailing_junk; static gint hf_auto_rp_group_num; #define UDP_PORT_PIM_RP_DISC 496 struct auto_rp_fixed_hdr { #define AUTO_RP_VERSION_MASK 0xf0 #define AUTO_RP_TYPE_MASK 0x0f guint8 ver_type; /* pim-autorp-spec01.txt defines version 1+ */ guint8 rp_count; /* Number of struct auto_rp_maps that follow the this header */ guint16 holdtime; /* Time in seconds this announcement is valid. 0 equals forever */ guint32 reserved; }; struct auto_rp_map_hdr { guint32 rp_address; /* The unicast IPv4 address of this RP */ #define AUTO_RP_PIM_VER_MASK 0x03 guint8 pim_version; /* RP's highest PIM version. 2-bit field */ guint8 group_count; /* Number of encoded group addresses that follow this header */ }; struct auto_rp_enc_grp_hdr { /* Encoded group address */ #define AUTO_RP_SIGN_MASK 0x01 guint8 prefix_sgn; /* 0 positive, 1 negative group prefix */ guint8 mask_len; /* Length of group prefix */ guint32 addr; /* Group prefix */ }; #define AUTO_RP_VER_1PLUS 1 static const value_string auto_rp_ver_vals[] = { {AUTO_RP_VER_1PLUS, "1 or 1+"}, {0, NULL} }; #define AUTO_RP_TYPE_ANNOUNCEMENT 1 #define AUTO_RP_TYPE_MAPPING 2 static const value_string auto_rp_type_vals[] = { {AUTO_RP_TYPE_ANNOUNCEMENT, "RP announcement"}, {AUTO_RP_TYPE_MAPPING, "RP mapping"}, {0, NULL} }; #define AUTO_RP_PIM_VERSION_UNKNOWN 0x00 #define AUTO_RP_PIM_VERSION_1 0x01 #define AUTO_RP_PIM_VERSION_2 0x02 #define AUTO_RP_PIM_VERSION_DUAL 0x03 static const value_string auto_rp_pim_ver_vals[] = { {AUTO_RP_PIM_VERSION_UNKNOWN, "Version unknown"}, {AUTO_RP_PIM_VERSION_1, "Version 1"}, {AUTO_RP_PIM_VERSION_2, "Version 2"}, {AUTO_RP_PIM_VERSION_DUAL, "Dual version 1 and 2"}, {0, NULL} }; #define AUTO_RP_GROUP_MASK_SIGN_POS 0 #define AUTO_RP_GROUP_MASK_SIGN_NEG 1 static const value_string auto_rp_mask_sign_vals[] = { {AUTO_RP_GROUP_MASK_SIGN_POS, "Positive group prefix"}, {AUTO_RP_GROUP_MASK_SIGN_NEG, "Negative group prefix"}, {0, NULL} }; static int do_auto_rp_map(wmem_allocator_t *scope, tvbuff_t *tvb, int offset, proto_tree *auto_rp_tree); static int dissect_auto_rp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { guint8 ver_type, rp_count; col_set_str(pinfo->cinfo, COL_PROTOCOL, "Auto-RP"); col_clear(pinfo->cinfo, COL_INFO); ver_type = tvb_get_guint8(tvb, 0); rp_count = tvb_get_guint8(tvb, 1); col_add_fstr(pinfo->cinfo, COL_INFO, "%s (v%s) for %u RP%s", val_to_str_const(lo_nibble(ver_type), auto_rp_type_vals, "Unknown"), val_to_str_const(hi_nibble(ver_type), auto_rp_ver_vals, "Unknown"), rp_count, plurality(rp_count, "", "s")); if (tree) { proto_item *ti; proto_tree *auto_rp_tree, *ver_type_tree; int i, offset; guint16 holdtime; offset = 0; ti = proto_tree_add_item(tree, proto_auto_rp, tvb, offset, -1, ENC_NA); auto_rp_tree = proto_item_add_subtree(ti, ett_auto_rp); ver_type_tree = proto_tree_add_subtree_format(auto_rp_tree, tvb, offset, 1, ett_auto_rp_ver_type, NULL, "Version: %s, Packet type: %s", val_to_str_const(hi_nibble(ver_type), auto_rp_ver_vals, "Unknown"), val_to_str_const(lo_nibble(ver_type), auto_rp_type_vals, "Unknown")); proto_tree_add_uint(ver_type_tree, hf_auto_rp_version, tvb, offset, 1, ver_type); proto_tree_add_uint(ver_type_tree, hf_auto_rp_type, tvb, offset, 1, ver_type); offset++; proto_tree_add_uint(auto_rp_tree, hf_auto_rp_count, tvb, offset, 1, rp_count); offset++; holdtime = tvb_get_ntohs(tvb, offset); proto_tree_add_uint_format_value(auto_rp_tree, hf_auto_rp_holdtime, tvb, offset, 2, holdtime, "%u second%s", holdtime, plurality(holdtime, "", "s")); offset+=2; proto_tree_add_item(auto_rp_tree, hf_auto_rp_reserved, tvb, offset, 4, ENC_BIG_ENDIAN); offset+=4; for (i = 0; i < rp_count; i++) offset = do_auto_rp_map(pinfo->pool, tvb, offset, auto_rp_tree); if (tvb_reported_length_remaining(tvb, offset) > 0) proto_tree_add_item(tree, hf_auto_rp_trailing_junk, tvb, offset, -1, ENC_NA); } return tvb_captured_length(tvb); } /* * Handles one Auto-RP map entry. Returns the new offset. */ static int do_auto_rp_map(wmem_allocator_t *scope, tvbuff_t *tvb, int offset, proto_tree *auto_rp_tree) { proto_tree *map_tree; guint8 group_count; int i; group_count = tvb_get_guint8(tvb, offset + 5); /* sizeof map header + n * sizeof encoded group addresses */ map_tree = proto_tree_add_subtree_format(auto_rp_tree, tvb, offset, 6 + group_count * 6, ett_auto_rp_map, NULL, "RP %s: %u group%s", tvb_ip_to_str(scope, tvb, offset), group_count, plurality(group_count, "", "s")); proto_tree_add_item(map_tree, hf_auto_rp_rp_addr, tvb, offset, 4, ENC_BIG_ENDIAN); offset += 4; proto_tree_add_item(map_tree, hf_auto_rp_pim_ver, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; proto_tree_add_uint(map_tree, hf_auto_rp_group_num, tvb, offset, 1, group_count); offset++; for (i = 0; i < group_count; i++) { proto_tree *grp_tree; guint8 sign, mask_len; sign = tvb_get_guint8(tvb, offset); mask_len = tvb_get_guint8(tvb, offset + 1); grp_tree = proto_tree_add_subtree_format(map_tree, tvb, offset, 6, ett_auto_rp_group, NULL, "Group %s/%u (%s)", tvb_ip_to_str(scope, tvb, offset + 2), mask_len, val_to_str_const(sign&AUTO_RP_SIGN_MASK, auto_rp_mask_sign_vals, "")); proto_tree_add_uint(grp_tree, hf_auto_rp_prefix_sgn, tvb, offset, 1, sign); offset++; proto_tree_add_uint(grp_tree, hf_auto_rp_mask_len, tvb, offset, 1, mask_len); offset++; proto_tree_add_item(grp_tree, hf_auto_rp_group_prefix, tvb, offset, 4, ENC_BIG_ENDIAN); offset += 4; } return offset; } void proto_register_auto_rp(void) { static hf_register_info hf[] = { { &hf_auto_rp_version, {"Protocol version", "auto_rp.version", FT_UINT8, BASE_DEC, VALS(auto_rp_ver_vals), AUTO_RP_VERSION_MASK, "Auto-RP protocol version", HFILL }}, { &hf_auto_rp_type, {"Packet type", "auto_rp.type", FT_UINT8, BASE_DEC, VALS(auto_rp_type_vals), AUTO_RP_TYPE_MASK, "Auto-RP packet type", HFILL }}, { &hf_auto_rp_count, {"RP count", "auto_rp.rp_count", FT_UINT8, BASE_DEC, NULL, 0, "The number of RP addresses contained in this message", HFILL }}, { &hf_auto_rp_group_num, {"Number of groups this RP maps to", "auto_rp.group_num", FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }}, { &hf_auto_rp_holdtime, {"Holdtime", "auto_rp.holdtime", FT_UINT16, BASE_DEC, NULL, 0, "The amount of time in seconds this announcement is valid", HFILL }}, { &hf_auto_rp_pim_ver, {"Version", "auto_rp.pim_ver", FT_UINT8, BASE_DEC, VALS(auto_rp_pim_ver_vals), AUTO_RP_PIM_VER_MASK, "RP's highest PIM version", HFILL }}, { &hf_auto_rp_rp_addr, {"RP address", "auto_rp.rp_addr", FT_IPv4, BASE_NONE, NULL, 0, "The unicast IP address of the RP", HFILL }}, { &hf_auto_rp_prefix_sgn, {"Sign", "auto_rp.prefix_sign", FT_UINT8, BASE_DEC, VALS(auto_rp_mask_sign_vals), AUTO_RP_SIGN_MASK, "Group prefix sign", HFILL }}, { &hf_auto_rp_mask_len, {"Mask length", "auto_rp.mask_len", FT_UINT8, BASE_DEC, NULL, 0x0, "Length of group prefix", HFILL }}, { &hf_auto_rp_group_prefix, {"Prefix", "auto_rp.group_prefix", FT_IPv4, BASE_NONE, NULL, 0, "Group prefix", HFILL }}, { &hf_auto_rp_reserved, {"Reserved", "auto_rp.reserved", FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }}, { &hf_auto_rp_trailing_junk, {"Trailing junk", "auto_rp.trailing_junk", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, }; static gint *ett[] = { &ett_auto_rp, &ett_auto_rp_ver_type, &ett_auto_rp_map, &ett_auto_rp_group }; proto_auto_rp = proto_register_protocol("Cisco Auto-RP", "Auto-RP", "auto_rp"); proto_register_field_array(proto_auto_rp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); auto_rp_handle = register_dissector("auto_rp", dissect_auto_rp, proto_auto_rp); } void proto_reg_handoff_auto_rp(void) { dissector_add_uint_with_preference("udp.port", UDP_PORT_PIM_RP_DISC, auto_rp_handle); } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 8 * tab-width: 8 * indent-tabs-mode: nil * End: * * vi: set shiftwidth=8 tabstop=8 expandtab: * :indentSize=8:tabSize=8:noTabs=true: */