diff options
Diffstat (limited to 'epan/dissectors/packet-auto_rp.c')
| -rw-r--r-- | epan/dissectors/packet-auto_rp.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/epan/dissectors/packet-auto_rp.c b/epan/dissectors/packet-auto_rp.c new file mode 100644 index 00000000..59fc5c5b --- /dev/null +++ b/epan/dissectors/packet-auto_rp.c @@ -0,0 +1,301 @@ +/* packet-auto_rp.c + * Routines for the Cisco Auto-RP protocol + * ftp://ftpeng.cisco.com/ftp/ipmulticast/specs/pim-autorp-spec01.txt + * + * Heikki Vatiainen <hessu@cs.tut.fi> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + +#include <epan/packet.h> +#include <epan/to_str.h> + +#include <wsutil/str_util.h> + +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 = -1; +static gint ett_auto_rp = -1; +static gint ett_auto_rp_ver_type = -1; +static gint ett_auto_rp_map = -1; +static gint ett_auto_rp_group = -1; + +static gint hf_auto_rp_version = -1; +static gint hf_auto_rp_type = -1; +static gint hf_auto_rp_count = -1; +static gint hf_auto_rp_holdtime = -1; +static gint hf_auto_rp_pim_ver = -1; +static gint hf_auto_rp_rp_addr = -1; +static gint hf_auto_rp_prefix_sgn = -1; +static gint hf_auto_rp_mask_len = -1; +static gint hf_auto_rp_group_prefix = -1; +static gint hf_auto_rp_reserved = -1; +static gint hf_auto_rp_trailing_junk = -1; +static gint hf_auto_rp_group_num = -1; + +#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(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(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(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(wmem_packet_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(wmem_packet_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: + */ |