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Refactored DNS and UDP class.

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This commit is contained in:
Matias Fontanini
2012-08-06 18:59:31 -03:00
parent e2ad917549
commit 66dfcb746b
6 changed files with 185 additions and 195 deletions
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199
src/dns.cpp
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@@ -22,17 +22,19 @@
#include <utility>
#include <stdexcept>
#include <cassert>
#include <memory>
#include "dns.h"
using std::string;
using std::list;
namespace Tins {
Tins::DNS::DNS() : PDU(255), extra_size(0) {
DNS::DNS() : PDU(255), extra_size(0) {
std::memset(&dns, 0, sizeof(dns));
}
Tins::DNS::DNS(const uint8_t *buffer, uint32_t total_sz) : PDU(255), extra_size(0) {
DNS::DNS(const uint8_t *buffer, uint32_t total_sz) : PDU(255), extra_size(0) {
if(total_sz < sizeof(dnshdr))
throw std::runtime_error("Not enough size for a DNS header in the buffer.");
std::memcpy(&dns, buffer, sizeof(dnshdr));
@@ -61,23 +63,43 @@ Tins::DNS::DNS(const uint8_t *buffer, uint32_t total_sz) : PDU(255), extra_size(
build_resource_list(addit, buffer, total_sz, additional());
}
Tins::DNS::DNS(const DNS &other) : PDU(255) {
copy_fields(&other);
copy_inner_pdu(other);
DNS::DNS(const DNS& rhs) : PDU(rhs) {
copy_fields(&rhs);
}
const uint8_t *Tins::DNS::build_resource_list(list<ResourceRecord*> &lst, const uint8_t *ptr, uint32_t &sz, uint16_t nrecs) {
DNS& DNS::operator=(const DNS& rhs) {
free_list(ans);
free_list(arity);
free_list(addit);
copy_fields(&rhs);
return *this;
}
DNS::~DNS() {
free_list(ans);
free_list(arity);
free_list(addit);
}
void DNS::free_list(ResourcesType &lst) {
while(lst.size()) {
delete lst.front();
lst.pop_front();
}
}
const uint8_t *DNS::build_resource_list(list<ResourceRecord*> &lst, const uint8_t *ptr, uint32_t &sz, uint16_t nrecs) {
const uint8_t *ptr_end(ptr + sz);
const uint8_t *parse_start(ptr);
for(uint16_t i(0); i < nrecs; ++i) {
const uint8_t *this_opt_start(ptr);
if(ptr + sizeof(uint16_t) > ptr_end)
throw std::runtime_error("Not enough size for a given resource.");
ResourceRecord *res;
std::auto_ptr<ResourceRecord> res;
if((*ptr & 0xc0)) {
uint16_t offset(*reinterpret_cast<const uint16_t*>(ptr));
offset = Utils::net_to_host_s(offset) & 0x3fff;
res = new OffsetedResourceRecord(Utils::net_to_host_s(offset));
res.reset(new OffsetedResourceRecord(Utils::net_to_host_s(offset)));
ptr += sizeof(uint16_t);
}
else {
@@ -87,7 +109,7 @@ const uint8_t *Tins::DNS::build_resource_list(list<ResourceRecord*> &lst, const
if(str_end == end)
throw std::runtime_error("Not enough size for a resource domain name.");
str_end++;
res = new NamedResourceRecord(string(ptr, str_end));
res.reset(new NamedResourceRecord(string(ptr, str_end)));
ptr = str_end;
}
if(ptr + sizeof(res->info) > ptr_end)
@@ -96,95 +118,81 @@ const uint8_t *Tins::DNS::build_resource_list(list<ResourceRecord*> &lst, const
ptr += sizeof(res->info);
if(ptr + sizeof(uint16_t) > ptr_end)
throw std::runtime_error("Not enough size for resource data size.");
res->data_sz = Utils::net_to_host_s(
*reinterpret_cast<const uint16_t*>(ptr)
// Store the option size.
res->data.resize(
Utils::net_to_host_s(*reinterpret_cast<const uint16_t*>(ptr))
);
ptr += sizeof(uint16_t);
if(ptr + res->data_sz > ptr_end)
if(ptr + res->data.size() > ptr_end)
throw std::runtime_error("Not enough size for resource data");
res->data = new uint8_t[res->data_sz];
if(contains_dname(res->info.type))
std::memcpy(res->data, ptr, res->data_sz);
else {
*(uint32_t*)res->data = Utils::net_to_host_l(*(uint32_t*)ptr);
}
std::copy(ptr, ptr + res->data.size(), res->data.begin());
else
*(uint32_t*)&res->data[0] = Utils::net_to_host_l(*(uint32_t*)ptr);
ptr += res->data_sz;
ptr += res->data.size();
extra_size += ptr - this_opt_start;
lst.push_back(res);
lst.push_back(res.release());
}
sz -= ptr - parse_start;
return ptr;
}
Tins::DNS::~DNS() {
free_list(ans);
free_list(arity);
free_list(addit);
}
void Tins::DNS::free_list(std::list<ResourceRecord*> &lst) {
while(lst.size()) {
delete[] lst.front()->data;
delete lst.front();
lst.pop_front();
}
}
uint32_t Tins::DNS::header_size() const {
uint32_t DNS::header_size() const {
return sizeof(dns) + extra_size;
}
void Tins::DNS::id(uint16_t new_id) {
void DNS::id(uint16_t new_id) {
dns.id = Utils::net_to_host_s(new_id);
}
void Tins::DNS::type(QRType new_qr) {
void DNS::type(QRType new_qr) {
dns.qr = new_qr;
}
void Tins::DNS::opcode(uint8_t new_opcode) {
void DNS::opcode(uint8_t new_opcode) {
dns.opcode = new_opcode;
}
void Tins::DNS::authoritative_answer(uint8_t new_aa) {
void DNS::authoritative_answer(uint8_t new_aa) {
dns.aa = new_aa;
}
void Tins::DNS::truncated(uint8_t new_tc) {
void DNS::truncated(uint8_t new_tc) {
dns.tc = new_tc;
}
void Tins::DNS::recursion_desired(uint8_t new_rd) {
void DNS::recursion_desired(uint8_t new_rd) {
dns.rd = new_rd;
}
void Tins::DNS::recursion_available(uint8_t new_ra) {
void DNS::recursion_available(uint8_t new_ra) {
dns.ra = new_ra;
}
void Tins::DNS::z(uint8_t new_z) {
void DNS::z(uint8_t new_z) {
dns.z = new_z;
}
void Tins::DNS::authenticated_data(uint8_t new_ad) {
void DNS::authenticated_data(uint8_t new_ad) {
dns.ad = new_ad;
}
void Tins::DNS::checking_disabled(uint8_t new_cd) {
void DNS::checking_disabled(uint8_t new_cd) {
dns.cd = new_cd;
}
void Tins::DNS::rcode(uint8_t new_rcode) {
void DNS::rcode(uint8_t new_rcode) {
dns.rcode = new_rcode;
}
bool Tins::DNS::contains_dname(uint16_t type) {
bool DNS::contains_dname(uint16_t type) {
return type == Utils::net_to_host_s(MX) || type == Utils::net_to_host_s(CNAME) ||
type == Utils::net_to_host_s(PTR) || type == Utils::net_to_host_s(NS);
}
void Tins::DNS::add_query(const string &name, QueryType type, QueryClass qclass) {
void DNS::add_query(const string &name, QueryType type, QueryClass qclass) {
string new_str;
parse_domain_name(name, new_str);
@@ -197,7 +205,7 @@ void Tins::DNS::add_query(const string &name, QueryType type, QueryClass qclass)
dns.questions = Utils::net_to_host_s(queries.size());
}
void Tins::DNS::add_query(const Query &query) {
void DNS::add_query(const Query &query) {
add_query(
query.name,
static_cast<QueryType>(query.type),
@@ -205,13 +213,13 @@ void Tins::DNS::add_query(const Query &query) {
);
}
void Tins::DNS::add_answer(const string &name, QueryType type, QueryClass qclass, uint32_t ttl, uint32_t ip) {
void DNS::add_answer(const string &name, QueryType type, QueryClass qclass, uint32_t ttl, uint32_t ip) {
ResourceRecord *res = make_record(name, type, qclass, ttl, ip);
ans.push_back(res);
dns.answers = Utils::net_to_host_s(ans.size());
}
void Tins::DNS::add_answer(const std::string &name, QueryType type, QueryClass qclass,
void DNS::add_answer(const std::string &name, QueryType type, QueryClass qclass,
uint32_t ttl, const std::string &dname) {
string new_str;
parse_domain_name(dname, new_str);
@@ -220,36 +228,36 @@ void Tins::DNS::add_answer(const std::string &name, QueryType type, QueryClass q
dns.answers = Utils::net_to_host_s(ans.size());
}
void Tins::DNS::add_answer(const std::string &name, QueryType type, QueryClass qclass,
void DNS::add_answer(const std::string &name, QueryType type, QueryClass qclass,
uint32_t ttl, const uint8_t *data, uint32_t sz) {
ResourceRecord *res = make_record(name, type, qclass, ttl, data, sz);
ans.push_back(res);
dns.answers = Utils::net_to_host_s(ans.size());
}
void Tins::DNS::add_authority(const string &name, QueryType type,
void DNS::add_authority(const string &name, QueryType type,
QueryClass qclass, uint32_t ttl, const uint8_t *data, uint32_t sz) {
ResourceRecord *res = make_record(name, type, qclass, ttl, data, sz);
arity.push_back(res);
dns.authority = Utils::net_to_host_s(arity.size());
}
void Tins::DNS::add_additional(const string &name, QueryType type, QueryClass qclass, uint32_t ttl, uint32_t ip) {
void DNS::add_additional(const string &name, QueryType type, QueryClass qclass, uint32_t ttl, uint32_t ip) {
ResourceRecord *res = make_record(name, type, qclass, ttl, ip);
addit.push_back(res);
dns.additional = Utils::net_to_host_s(addit.size());
}
Tins::DNS::ResourceRecord *Tins::DNS::make_record(const std::string &name, QueryType type, QueryClass qclass, uint32_t ttl, uint32_t ip) {
DNS::ResourceRecord *DNS::make_record(const std::string &name, QueryType type, QueryClass qclass, uint32_t ttl, uint32_t ip) {
ip = Utils::net_to_host_l(ip);
return make_record(name, type, qclass, ttl, reinterpret_cast<uint8_t*>(&ip), sizeof(ip));
}
Tins::DNS::ResourceRecord *Tins::DNS::make_record(const std::string &name, QueryType type, QueryClass qclass, uint32_t ttl, const std::string &dname) {
DNS::ResourceRecord *DNS::make_record(const std::string &name, QueryType type, QueryClass qclass, uint32_t ttl, const std::string &dname) {
return make_record(name, type, qclass, ttl, reinterpret_cast<const uint8_t*>(dname.c_str()), dname.size() + 1);
}
Tins::DNS::ResourceRecord *Tins::DNS::make_record(const std::string &name, QueryType type, QueryClass qclass, uint32_t ttl, const uint8_t *ptr, uint32_t len) {
DNS::ResourceRecord *DNS::make_record(const std::string &name, QueryType type, QueryClass qclass, uint32_t ttl, const uint8_t *ptr, uint32_t len) {
string nm;
parse_domain_name(name, nm);
uint16_t index = find_domain_name(nm);
@@ -265,7 +273,7 @@ Tins::DNS::ResourceRecord *Tins::DNS::make_record(const std::string &name, Query
return res;
}
uint32_t Tins::DNS::find_domain_name(const std::string &dname) {
uint32_t DNS::find_domain_name(const std::string &dname) {
uint16_t index(sizeof(dnshdr));
list<Query>::const_iterator it(queries.begin());
for(; it != queries.end() && it->name != dname; ++it)
@@ -279,8 +287,8 @@ uint32_t Tins::DNS::find_domain_name(const std::string &dname) {
return 0;
}
bool Tins::DNS::find_domain_name(const std::string &dname, const std::list<ResourceRecord*> &lst, uint16_t &out) {
list<ResourceRecord*>::const_iterator it(lst.begin());
bool DNS::find_domain_name(const std::string &dname, const ResourcesType &lst, uint16_t &out) {
ResourcesType::const_iterator it(lst.begin());
while(it != lst.end()) {
if((*it)->matches(dname))
break;
@@ -290,7 +298,7 @@ bool Tins::DNS::find_domain_name(const std::string &dname, const std::list<Resou
return it != lst.end();
}
void Tins::DNS::parse_domain_name(const std::string &dn, std::string &out) const {
void DNS::parse_domain_name(const std::string &dn, std::string &out) const {
size_t last_index(0), index;
while((index = dn.find('.', last_index+1)) != string::npos) {
out.push_back(index - last_index);
@@ -301,7 +309,7 @@ void Tins::DNS::parse_domain_name(const std::string &dn, std::string &out) const
out.append(dn.begin() + last_index, dn.end());
}
void Tins::DNS::unparse_domain_name(const std::string &dn, std::string &out) const {
void DNS::unparse_domain_name(const std::string &dn, std::string &out) const {
if(dn.size()) {
uint32_t index(1), len(dn[0]);
while(index + len < dn.size() && len) {
@@ -320,7 +328,7 @@ void Tins::DNS::unparse_domain_name(const std::string &dn, std::string &out) con
}
}
void Tins::DNS::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
void DNS::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
assert(total_sz >= sizeof(dns) + extra_size);
std::memcpy(buffer, &dns, sizeof(dns));
buffer += sizeof(dns);
@@ -337,13 +345,13 @@ void Tins::DNS::write_serialization(uint8_t *buffer, uint32_t total_sz, const PD
buffer = serialize_list(addit, buffer);
}
uint8_t *Tins::DNS::serialize_list(const std::list<ResourceRecord*> &lst, uint8_t *buffer) const {
for(list<ResourceRecord*>::const_iterator it(lst.begin()); it != lst.end(); ++it)
uint8_t *DNS::serialize_list(const ResourcesType &lst, uint8_t *buffer) const {
for(ResourcesType::const_iterator it(lst.begin()); it != lst.end(); ++it)
buffer += (*it)->write(buffer);
return buffer;
}
void Tins::DNS::add_suffix(uint32_t index, const uint8_t *data, uint32_t sz) {
void DNS::add_suffix(uint32_t index, const uint8_t *data, uint32_t sz) {
uint32_t i(0), suff_sz(data[0]);
SuffixMap::iterator it;
while((i + suff_sz + 1 <= sz || (suff_sz == 0xc0 && i + 1 < sz)) && suff_sz) {
@@ -362,9 +370,9 @@ void Tins::DNS::add_suffix(uint32_t index, const uint8_t *data, uint32_t sz) {
}
}
uint32_t Tins::DNS::build_suffix_map(uint32_t index, const list<ResourceRecord*> &lst) {
uint32_t DNS::build_suffix_map(uint32_t index, const list<ResourceRecord*> &lst) {
const string *str;
for(list<ResourceRecord*>::const_iterator it(lst.begin()); it != lst.end(); ++it) {
for(ResourcesType::const_iterator it(lst.begin()); it != lst.end(); ++it) {
str = (*it)->dname_pointer();
if(str) {
add_suffix(index, (uint8_t*)str->c_str(), str->size());
@@ -387,7 +395,7 @@ uint32_t Tins::DNS::build_suffix_map(uint32_t index, const list<ResourceRecord*>
return index;
}
uint32_t Tins::DNS::build_suffix_map(uint32_t index, const list<Query> &lst) {
uint32_t DNS::build_suffix_map(uint32_t index, const list<Query> &lst) {
for(list<Query>::const_iterator it(lst.begin()); it != lst.end(); ++it) {
add_suffix(index, (uint8_t*)it->name.c_str(), it->name.size());
index += it->name.size() + 1 + (sizeof(uint16_t) << 1);
@@ -395,7 +403,7 @@ uint32_t Tins::DNS::build_suffix_map(uint32_t index, const list<Query> &lst) {
return index;
}
void Tins::DNS::build_suffix_map() {
void DNS::build_suffix_map() {
uint32_t index(sizeof(dnshdr));
index = build_suffix_map(index, queries);
index = build_suffix_map(index, ans);
@@ -403,7 +411,7 @@ void Tins::DNS::build_suffix_map() {
build_suffix_map(index, addit);
}
void Tins::DNS::compose_name(const uint8_t *ptr, uint32_t sz, std::string &out) {
void DNS::compose_name(const uint8_t *ptr, uint32_t sz, std::string &out) {
uint32_t i(0);
while(i < sz) {
if(i && ptr[i])
@@ -444,13 +452,13 @@ void Tins::DNS::compose_name(const uint8_t *ptr, uint32_t sz, std::string &out)
}
}
void Tins::DNS::convert_resources(const std::list<ResourceRecord*> &lst, std::list<Resource> &res) {
void DNS::convert_resources(const ResourcesType &lst, std::list<Resource> &res) {
if(!suffixes.size())
build_suffix_map();
const string *str_ptr;
const uint8_t *ptr;
uint32_t sz;
for(list<ResourceRecord*>::const_iterator it(lst.begin()); it != lst.end(); ++it) {
for(ResourcesType::const_iterator it(lst.begin()); it != lst.end(); ++it) {
string dname, addr;
if((str_ptr = (*it)->dname_pointer()))
compose_name(reinterpret_cast<const uint8_t*>(str_ptr->c_str()), str_ptr->size(), dname);
@@ -476,7 +484,7 @@ void Tins::DNS::convert_resources(const std::list<ResourceRecord*> &lst, std::li
}
}
list<Tins::DNS::Query> Tins::DNS::dns_queries() const {
list<DNS::Query> DNS::dns_queries() const {
list<Query> output;
for(std::list<Query>::const_iterator it(queries.begin()); it != queries.end(); ++it) {
string dn;
@@ -486,20 +494,13 @@ list<Tins::DNS::Query> Tins::DNS::dns_queries() const {
return output;
}
list<Tins::DNS::Resource> Tins::DNS::dns_answers() {
list<DNS::Resource> DNS::dns_answers() {
list<Resource> res;
convert_resources(ans, res);
return res;
}
Tins::PDU *Tins::DNS::clone_pdu() const {
DNS *new_pdu = new DNS();
new_pdu->copy_fields(this);
new_pdu->copy_inner_pdu(*this);
return new_pdu;
}
void Tins::DNS::copy_fields(const DNS *other) {
void DNS::copy_fields(const DNS *other) {
std::memcpy(&dns, &other->dns, sizeof(dns));
extra_size = other->extra_size;
queries = other->queries;
@@ -508,40 +509,30 @@ void Tins::DNS::copy_fields(const DNS *other) {
copy_list(other->addit, addit);
}
void Tins::DNS::copy_list(const list<ResourceRecord*> &from, list<ResourceRecord*> &to) const {
for(list<ResourceRecord*>::const_iterator it(from.begin()); it != from.end(); ++it) {
void DNS::copy_list(const ResourcesType &from, ResourcesType &to) const {
for(ResourcesType::const_iterator it(from.begin()); it != from.end(); ++it) {
to.push_back((*it)->clone());
}
}
// ResourceRecord
void Tins::DNS::ResourceRecord::copy_fields(ResourceRecord *other) const {
std::memcpy(&other->info, &info, sizeof(info));
other->data_sz = data_sz;
other->data = new uint8_t[data_sz];
std::memcpy(other->data, data, data_sz);
}
uint32_t Tins::DNS::ResourceRecord::write(uint8_t *buffer) const {
uint32_t sz(do_write(buffer));
uint32_t DNS::ResourceRecord::write(uint8_t *buffer) const {
const uint32_t sz(do_write(buffer));
buffer += sz;
std::memcpy(buffer, &info, sizeof(info));
buffer += sizeof(info);
*((uint16_t*)buffer) = Utils::net_to_host_s(data_sz);
*((uint16_t*)buffer) = Utils::net_to_host_s(data.size());
buffer += sizeof(uint16_t);
std::memcpy(buffer, data, data_sz);
return sz + sizeof(info) + sizeof(uint16_t) + data_sz;
std::copy(data.begin(), data.end(), buffer);
return sz + sizeof(info) + sizeof(uint16_t) + data.size();
}
Tins::DNS::ResourceRecord *Tins::DNS::OffsetedResourceRecord::clone() const {
ResourceRecord *r = new OffsetedResourceRecord(offset);
copy_fields(r);
return r;
DNS::ResourceRecord *DNS::OffsetedResourceRecord::clone() const {
return new OffsetedResourceRecord(*this);
}
Tins::DNS::ResourceRecord *Tins::DNS::NamedResourceRecord::clone() const {
ResourceRecord *r = new NamedResourceRecord(name);
copy_fields(r);
return r;
DNS::ResourceRecord *DNS::NamedResourceRecord::clone() const {
return new NamedResourceRecord(*this);
}
}