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Code Issues Releases Wiki Activity

Parse and serialize MX preference field correctly

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This commit is contained in:
Matias Fontanini
2016-01-11 15:48:03 -08:00
parent 75add84741
commit ca56cc10dd
3 changed files with 89 additions and 21 deletions
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24
src/dns.cpp
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@@ -203,7 +203,8 @@ void DNS::add_record(const Resource& resource, const sections_type& sections) {
// will end up being inconsistent.
IPv4Address v4_addr;
IPv6Address v6_addr;
string buffer = encode_domain_name(resource.dname()), encoded_data;
string buffer = encode_domain_name(resource.dname()),
encoded_data;
// By default the data size is the length of the data field.
size_t data_size = resource.data().size();
if (resource.type() == A) {
@@ -220,13 +221,17 @@ void DNS::add_record(const Resource& resource, const sections_type& sections) {
}
size_t offset = buffer.size() + sizeof(uint16_t) * 3 + sizeof(uint32_t) + data_size,
threshold = sections.empty() ? records_data_.size() :* sections.front().first;
// Skip the preference field
// Take into account the MX preference field
if (resource.type() == MX) {
offset += sizeof(uint16_t);
}
for (size_t i = 0; i < sections.size(); ++i) {
update_records(*sections[i].first, sections[i].second,
static_cast<uint32_t>(threshold), static_cast<uint32_t>(offset));
update_records(
*sections[i].first,
sections[i].second,
static_cast<uint32_t>(threshold),
static_cast<uint32_t>(offset)
);
}
records_data_.insert(
@@ -241,7 +246,7 @@ void DNS::add_record(const Resource& resource, const sections_type& sections) {
stream.write_be(resource.ttl());
stream.write_be<uint16_t>(data_size + (resource.type() == MX ? 2 : 0));
if (resource.type() == MX) {
stream.skip(sizeof(uint16_t));
stream.write_be(resource.preference());
}
if (resource.type() == A) {
stream.write(v4_addr);
@@ -380,15 +385,15 @@ void DNS::convert_records(const uint8_t* ptr,
// Retrieve the record's domain name.
stream.skip(compose_name(stream.pointer(), dname));
// Retrieve the following fields.
uint16_t type, qclass, data_size;
uint16_t type, qclass, data_size, preference = 0;
uint32_t ttl;
type = stream.read_be<uint16_t>();
qclass = stream.read_be<uint16_t>();
ttl = stream.read_be<uint32_t>();
data_size = stream.read_be<uint16_t>();
// Skip the preference field if it's MX
// Read the preference field if it's MX
if (type == MX) {
stream.skip(sizeof(uint16_t));
preference = stream.read_be<uint16_t>();
data_size -= sizeof(uint16_t);
}
if (!stream.can_read(data_size)) {
@@ -431,7 +436,8 @@ void DNS::convert_records(const uint8_t* ptr,
(used_small_buffer) ? small_addr_buf : addr,
type,
qclass,
ttl
ttl,
preference
)
);
}