From 7c56f4776b0e78ae0581e5df672e20f6ee1bf56d Mon Sep 17 00:00:00 2001 From: Guy Harris Date: Mon, 8 Jan 2018 21:08:32 -0800 Subject: Clean up dissection of "power requested" and "power available" TLVs. Fix the addition of power values to the top-level item for the TLV so that it actually adds power values. Make the list of power values in that item display correctly, without extra commas. Fail if the length of the TLV is less than 8. (We should really add an expert info item for that.) Change-Id: Ic4229c0652306f69156b8341c9fbb67cacc8154c Reviewed-on: https://code.wireshark.org/review/25215 Reviewed-by: Guy Harris --- epan/dissectors/packet-cdp.c | 74 ++++++++++++++++++++++++++------------------ 1 file changed, 44 insertions(+), 30 deletions(-) (limited to 'epan/dissectors/packet-cdp.c') diff --git a/epan/dissectors/packet-cdp.c b/epan/dissectors/packet-cdp.c index 2b93dac651..17bd381c47 100644 --- a/epan/dissectors/packet-cdp.c +++ b/epan/dissectors/packet-cdp.c @@ -279,12 +279,13 @@ dissect_cdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) int offset = 0; guint16 type; guint16 length, data_length; - proto_item *tlvi = NULL; - proto_tree *tlv_tree = NULL; + proto_item *tlvi; + proto_tree *tlv_tree; int real_length; guint32 naddresses; guint32 power_avail_len, power_avail; guint32 power_req_len, power_req; + gboolean first; int addr_length; vec_t cksum_vec[1]; @@ -342,6 +343,7 @@ dissect_cdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) offset += 2; while (tvb_reported_length_remaining(tvb, offset) != 0) { + tlv_tree = NULL; type = tvb_get_ntohs(tvb, offset + TLV_TYPE); length = tvb_get_ntohs(tvb, offset + TLV_LENGTH); if (length < 4) { @@ -739,57 +741,69 @@ dissect_cdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) break; case TYPE_POWER_REQUESTED: + tlvi = NULL; if (tree) { tlv_tree = proto_tree_add_subtree(cdp_tree, tvb, - offset, length, ett_cdp_tlv, NULL, "Power Request: "); + offset, length, ett_cdp_tlv, &tlvi, + "Power Request"); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, tvb, offset + TLV_TYPE, 2, ENC_BIG_ENDIAN); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, tvb, offset + TLV_LENGTH, 2, ENC_BIG_ENDIAN); proto_tree_add_item(tlv_tree, hf_cdp_request_id, tvb, offset + 4, 2, ENC_BIG_ENDIAN); proto_tree_add_item(tlv_tree, hf_cdp_management_id, tvb, offset + 6, 2, ENC_BIG_ENDIAN); } - power_req_len = (tvb_get_ntohs(tvb, offset + TLV_LENGTH)) - 8; + power_req_len = tvb_get_ntohs(tvb, offset + TLV_LENGTH); + if (power_req_len < 8) { + offset += power_req_len; + break; + } + power_req_len -= 8; /* Move offset to where the list of Power Request Values Exist */ offset += 8; - while(power_req_len) { - if (power_req_len > 4) { - proto_tree_add_item_ret_uint(tlv_tree, hf_cdp_power_requested, tvb, offset, 4, ENC_BIG_ENDIAN, &power_req); - proto_item_append_text(tlvi, "%u mW, ", power_req); - power_req_len -= 4; - offset += 4; - } else { - if (power_req_len == 4) { - proto_tree_add_item_ret_uint(tlv_tree, hf_cdp_power_requested, tvb, offset, 4, ENC_BIG_ENDIAN, &power_req); - proto_item_append_text(tlvi, "%u mW", power_req); - } - offset += power_req_len; - break; - } + first = TRUE; + while (power_req_len >= 4) { + proto_tree_add_item_ret_uint(tlv_tree, hf_cdp_power_requested, tvb, offset, 4, ENC_BIG_ENDIAN, &power_req); + if (first) { + proto_item_append_text(tlvi, ": %u mW", power_req); + first = FALSE; + } else + proto_item_append_text(tlvi, ", %u mW", power_req); + power_req_len -= 4; + offset += 4; } + offset += power_req_len; break; case TYPE_POWER_AVAILABLE: + tlvi = NULL; if (tree) { tlv_tree = proto_tree_add_subtree(cdp_tree, tvb, - offset, length, ett_cdp_tlv, NULL, "Power Available: "); + offset, length, ett_cdp_tlv, &tlvi, + "Power Available"); proto_tree_add_item(tlv_tree, hf_cdp_tlvtype, tvb, offset + TLV_TYPE, 2, ENC_BIG_ENDIAN); proto_tree_add_item(tlv_tree, hf_cdp_tlvlength, tvb, offset + TLV_LENGTH, 2, ENC_BIG_ENDIAN); proto_tree_add_item(tlv_tree, hf_cdp_request_id, tvb, offset + 4, 2, ENC_BIG_ENDIAN); proto_tree_add_item(tlv_tree, hf_cdp_management_id, tvb, offset + 6, 2, ENC_BIG_ENDIAN); } - power_avail_len = (tvb_get_ntohs(tvb, offset + TLV_LENGTH)) - 8; + power_avail_len = tvb_get_ntohs(tvb, offset + TLV_LENGTH); + if (power_avail_len < 8) { + offset += power_avail_len; + break; + } + power_avail_len -= 8; /* Move offset to where the list of Power Available Values Exist */ offset += 8; - while(power_avail_len) { - if (power_avail_len >= 4) { - proto_tree_add_item_ret_uint(tlv_tree, hf_cdp_power_available, tvb, offset, 4, ENC_BIG_ENDIAN, &power_avail); - proto_item_append_text(tlvi, "%u mW, ", power_avail); - power_avail_len -= 4; - offset += 4; - } else { - offset += power_avail_len; - break; - } + first = TRUE; + while (power_avail_len >= 4) { + proto_tree_add_item_ret_uint(tlv_tree, hf_cdp_power_available, tvb, offset, 4, ENC_BIG_ENDIAN, &power_avail); + if (first) { + proto_item_append_text(tlvi, ": %u mW", power_avail); + first = FALSE; + } else + proto_item_append_text(tlvi, ", %u mW", power_avail); + power_avail_len -= 4; + offset += 4; } + offset += power_avail_len; break; case TYPE_NRGYZ: -- cgit v1.2.3