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IPv6: Set (jumbo) length by inspecting hop-by-hop header, if existing 

Change-Id: I84bade7526ef3f094875eaf207b2650d734ed10f
Reviewed-on: https://code.wireshark.org/review/16523
Petri-Dish: João Valverde <j@v6e.pt>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: João Valverde <j@v6e.pt>
This commit is contained in:
João Valverde 2016-07-16 14:07:40 +01:00 committed by João Valverde
parent de7241c13b
commit 83733a340f
1 changed files with 56 additions and 39 deletions
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95
epan/dissectors/packet-ipv6.c
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@ -322,7 +322,7 @@ static expert_field ei_ipv6_opt_jumbo_not_hopbyhop = EI_INIT;
static expert_field ei_ipv6_opt_invalid_len = EI_INIT;
static expert_field ei_ipv6_opt_unknown_data = EI_INIT;
static expert_field ei_ipv6_hopopts_not_first = EI_INIT;
static expert_field ei_ipv6_bogus_payload_length = EI_INIT;
static expert_field ei_ipv6_plen_exceeds_framing = EI_INIT;
static expert_field ei_ipv6_bogus_ipv6_version = EI_INIT;
static expert_field ei_ipv6_invalid_header = EI_INIT;
@ -1239,36 +1239,29 @@ struct opt_proto_item {
*/
static gint
dissect_opt_jumbo(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *opt_tree,
struct opt_proto_item *opt_ti, guint8 opt_len, gboolean hopopts)
struct opt_proto_item *opt_ti, guint8 opt_len, gboolean hopopts, guint16 ip6_plen)
{
ipv6_meta_t *ipv6_info = (ipv6_meta_t *)p_get_proto_data(pinfo->pool, pinfo, proto_ipv6, IPV6_PROTO_META);
proto_item *pi = proto_tree_get_parent(opt_tree);
proto_item *ti;
guint32 jumbo_plen;
guint32 jumbo_plen = 0;
if (opt_len != 4) {
expert_add_info_format(pinfo, opt_ti->len, &ei_ipv6_opt_invalid_len,
"Jumbo Payload: Invalid length (%u bytes)", opt_len);
}
ti = proto_tree_add_item(opt_tree, hf_ipv6_opt_jumbo, tvb, offset, 4, ENC_BIG_ENDIAN);
jumbo_plen = tvb_get_ntohl(tvb, offset);
ti = proto_tree_add_item_ret_uint(opt_tree, hf_ipv6_opt_jumbo, tvb, offset, 4, ENC_BIG_ENDIAN, &jumbo_plen);
offset += 4;
if (!hopopts) {
expert_add_info(pinfo, pi, &ei_ipv6_opt_jumbo_not_hopbyhop);
return offset;
}
if (ipv6_info->ip6_plen != 0) {
if (ip6_plen != 0) {
expert_add_info(pinfo, pi, &ei_ipv6_opt_jumbo_prohibited);
proto_item_append_text(ti, " [Ignored]");
return offset;
}
if (jumbo_plen < 65536) {
expert_add_info(pinfo, ti, &ei_ipv6_opt_jumbo_truncated);
return offset;
}
ipv6_info->jumbo_plen = jumbo_plen;
return offset;
}
@ -1656,6 +1649,7 @@ dissect_opts(tvbuff_t *tvb, int offset, proto_tree *tree, packet_info *pinfo, ws
guint8 opt_type, opt_len, opt_start;
gboolean hopopts;
struct opt_proto_item opt_ti;
ipv6_meta_t *ipv6_info = get_ipv6_meta_data(pinfo);
hopopts = (exthdr_proto == proto_ipv6_hopopts);
@ -1737,7 +1731,7 @@ dissect_opts(tvbuff_t *tvb, int offset, proto_tree *tree, packet_info *pinfo, ws
opt_start = offset;
switch (opt_type) {
case IP6OPT_JUMBO:
offset = dissect_opt_jumbo(tvb, offset, pinfo, opt_tree, &opt_ti, opt_len, hopopts);
offset = dissect_opt_jumbo(tvb, offset, pinfo, opt_tree, &opt_ti, opt_len, hopopts, ipv6_info->ip6_plen);
break;
case IP6OPT_RPL:
offset = dissect_opt_rpl(tvb, offset, pinfo, opt_tree, &opt_ti, opt_len);
@ -1816,6 +1810,38 @@ dissect_dstopts(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data
return dissect_opts(tvb, 0, tree, pinfo, (ws_ip *)data, proto_ipv6_dstopts);
}
static gboolean
ipv6_check_jumbo_plen(tvbuff_t *tvb, gint offset, packet_info *pinfo)
{
gint offset_end, opt_type, opt_len;
guint32 jumbo_plen;
ipv6_meta_t *ipv6_info;
offset_end = offset + ((tvb_get_guint8(tvb, offset + 1) +1) * 8);
offset +=2;
while (offset < offset_end && tvb_bytes_exist(tvb, offset, 6)) {
opt_type = tvb_get_guint8(tvb, offset);
offset += 1;
if (opt_type == IP6OPT_PAD1) {
continue;
}
opt_len = tvb_get_guint8(tvb, offset);
offset += 1;
if (opt_type == IP6OPT_JUMBO && opt_len == 4) {
jumbo_plen = tvb_get_guint32(tvb, offset, ENC_BIG_ENDIAN);
if (jumbo_plen > G_MAXUINT16) {
ipv6_info = get_ipv6_meta_data(pinfo);
ipv6_info->jumbo_plen = jumbo_plen;
return TRUE;
}
return FALSE;
}
offset += opt_len;
}
return FALSE;
}
static int
dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
@ -1826,6 +1852,7 @@ dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_
guint8 nxt_saved;
int advance;
int offset;
guint reported_plen;
tvbuff_t *next_tvb, *options_tvb;
gboolean save_fragmented;
gboolean show_data = FALSE, loop = TRUE;
@ -2123,37 +2150,27 @@ dissect_ipv6(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_
p_add_proto_data(pinfo->pool, pinfo, proto_ipv6,
(pinfo->curr_layer_num<<8) | IPV6_PROTO_NXT_HDR, GUINT_TO_POINTER(iph.ip_nxt));
offset += IPv6_HDR_SIZE;
advance = 0;
if (iph.ip_nxt == IP_PROTO_HOPOPTS) {
options_tvb = tvb_new_subset_remaining(tvb, offset);
nxt_handle = dissector_get_uint_handle(ipv6_next_header_dissector_table, IP_PROTO_HOPOPTS);
advance = call_dissector_with_data(nxt_handle, options_tvb, pinfo, ipv6_exthdr_tree, &iph);
if (advance > 0) {
iph.ip_nxt = tvb_get_guint8(tvb, offset);
offset += advance;
if (ipv6_info->jumbo_plen != 0) {
proto_item_append_text(ti_ipv6_plen, " (Jumbogram)");
iph.ip_len = ipv6_info->jumbo_plen;
} else if (iph.ip_len == 0) {
/* IPv6 length zero is invalid if there is a hop-by-hop header without jumbo option */
col_add_fstr(pinfo->cinfo, COL_INFO, "Invalid IPv6 payload length");
if (ti_ipv6_plen) {
expert_add_info(pinfo, ti_ipv6_plen, &ei_ipv6_opt_jumbo_missing);
}
return tvb_captured_length(tvb);
}
/* Check for Jumbo option */
if (iph.ip_len == 0 && iph.ip_nxt == IP_PROTO_HOPOPTS) {
if (ipv6_check_jumbo_plen(tvb, offset, pinfo)) {
proto_item_append_text(ti_ipv6_plen, " (Jumbogram)");
iph.ip_len = ipv6_info->jumbo_plen;
} else {
/* IPv6 length zero is invalid if there is a hop-by-hop header without jumbo option */
col_add_fstr(pinfo->cinfo, COL_INFO, "Invalid IPv6 payload length");
expert_add_info(pinfo, ti_ipv6_plen, &ei_ipv6_opt_jumbo_missing);
}
}
if (!pinfo->flags.in_error_pkt && iph.ip_len > (tvb_reported_length(tvb) - 40)) {
expert_add_info_format(pinfo, ti_ipv6_plen, &ei_ipv6_bogus_payload_length,
"IPv6 payload length exceeds framing length (%d bytes)",
tvb_reported_length(tvb) - 40);
reported_plen = tvb_reported_length(tvb) - IPv6_HDR_SIZE;
if (!pinfo->flags.in_error_pkt && iph.ip_len > reported_plen) {
expert_add_info_format(pinfo, ti_ipv6_plen, &ei_ipv6_plen_exceeds_framing,
"IPv6 payload length exceeds framing length (%d bytes)", reported_plen);
}
/* Adjust the length of this tvbuff to include only the IPv6 datagram. */
set_actual_length(tvb, iph.ip_len + IPv6_HDR_SIZE);
iph.ip_len -= advance;
save_fragmented = pinfo->fragmented;
while (loop && !show_data) {
@ -3094,8 +3111,8 @@ proto_register_ipv6(void)
{ "ipv6.opt.unknown_data.expert", PI_UNDECODED, PI_NOTE,
"Unknown Data (not interpreted)", EXPFILL }
},
{ &ei_ipv6_bogus_payload_length,
{ "ipv6.bogus_payload_length", PI_PROTOCOL, PI_WARN,
{ &ei_ipv6_plen_exceeds_framing,
{ "ipv6.plen_exceeds_framing", PI_PROTOCOL, PI_WARN,
"IPv6 payload length does not match expected framing length", EXPFILL }
},
{ &ei_ipv6_bogus_ipv6_version,