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Use actual payload length to construct inner PDU. (#179)

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Fixes #178
This commit is contained in:
Ed Catmur
2017-01-16 17:36:33 +00:00
committed by Matias Fontanini
parent d5cba00ce0
commit 9051197603
3 changed files with 59 additions and 6 deletions
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34
src/ipv6.cpp
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@@ -82,6 +82,7 @@ IPv6::IPv6(const uint8_t* buffer, uint32_t total_sz)
InputMemoryStream stream(buffer, total_sz);
stream.read(header_);
uint8_t current_header = header_.next_header;
uint32_t actual_payload_length = payload_length();
bool is_payload_fragmented = false;
while (stream) {
if (is_extension_header(current_header)) {
@@ -93,24 +94,47 @@ IPv6::IPv6(const uint8_t* buffer, uint32_t total_sz)
// minus one, from the next_header field.
const uint32_t ext_size = (static_cast<uint32_t>(stream.read<uint8_t>()) + 1) * 8;
const uint32_t payload_size = ext_size - sizeof(uint8_t) * 2;
if (!stream.can_read(ext_size)) {
if (!stream.can_read(payload_size)) {
throw malformed_packet();
}
// minus one, from the size field
add_ext_header(ext_header(ext_type, payload_size, stream.pointer()));
if (actual_payload_length == 0u && current_header == HOP_BY_HOP) {
// could be a jumbogram, look for Jumbo Payload Option
InputMemoryStream options(stream.pointer(), payload_size);
while (options) {
const uint8_t opt_type = options.read<uint8_t>();
if (opt_type == PAD_1) {
continue;
}
const uint8_t opt_size = options.read<uint8_t>();
if (opt_type == JUMBO_PAYLOAD) {
if (opt_size != 4) {
throw malformed_packet();
}
actual_payload_length = stream.read_be<uint32_t>();
break;
}
options.skip(opt_size);
}
}
current_header = ext_type;
actual_payload_length -= ext_size;
stream.skip(payload_size);
}
else {
if (!stream.can_read(actual_payload_length)) {
throw malformed_packet();
}
if (is_payload_fragmented) {
inner_pdu(new Tins::RawPDU(stream.pointer(), stream.size()));
inner_pdu(new Tins::RawPDU(stream.pointer(), actual_payload_length));
}
else {
inner_pdu(
Internals::pdu_from_flag(
static_cast<Constants::IP::e>(current_header),
stream.pointer(),
stream.size(),
actual_payload_length,
false
)
);
@@ -119,11 +143,11 @@ IPv6::IPv6(const uint8_t* buffer, uint32_t total_sz)
Internals::allocate<IPv6>(
current_header,
stream.pointer(),
stream.size()
actual_payload_length
)
);
if (!inner_pdu()) {
inner_pdu(new Tins::RawPDU(stream.pointer(), stream.size()));
inner_pdu(new Tins::RawPDU(stream.pointer(), actual_payload_length));
}
}
}