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magic numbers to defs, llarp_buffer_t implementation, cleanup, Michael/Sang code review changes

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pull/58/head
Ryan Tharp 6 years ago
parent 5d94125346
commit 638692f48a
2 changed files with 47 additions and 87 deletions
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10
include/llarp/dns.hpp
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@ -14,6 +14,14 @@
#include <llarp/net.hpp> // for llarp::Addr , llarp::huint32_t
#include <llarp/dns_rectypes.hpp>
#define LLARP_DNS_RECTYPE_A 1
#define LLARP_DNS_RECTYPE_NS 2
#define LLARP_DNS_RECTYPE_CNAME 5
#define LLARP_DNS_RECTYPE_SOA 6
#define LLARP_DNS_RECTYPE_PTR 12
#define LLARP_DNS_RECTYPE_MX 15
#define LLARP_DNS_RECTYPE_TXT 16
struct dnsd_context;
// dnsc can work over any UDP socket
@ -113,7 +121,7 @@ extern "C"
get32bits(const char *&buffer) throw();
dns_msg_header *
decode_hdr(const char *buffer);
decode_hdr(llarp_buffer_t &buffer);
dns_msg_question *
decode_question(const char *buffer, uint32_t *pos);

124
llarp/dns.cpp
Unescape Escape View File

@ -245,15 +245,10 @@ packet2bytes(dns_packet &in)
// don't pull these from the header, trust what we actually have more
vput16bits(write_buffer, in.questions.size()); // QD (number of questions)
vput16bits(write_buffer, in.answers.size()); // AN (number of answers)
// be lazy for now
// vput16bits(write_buffer, 0); // NS (number of auth RRs)
// vput16bits(write_buffer, 0); // AR (number of Additional
vput16bits(write_buffer, in.auth_rrs.size()); // NS (number of auth RRs)
vput16bits(write_buffer,
in.additional_rrs.size()); // AR (number of Additional RRs)
// llarp::LogInfo("Header took ", write_buffer.size());
for(auto &it : in.questions)
{
// code question
@ -261,9 +256,7 @@ packet2bytes(dns_packet &in)
vput16bits(write_buffer, it->type);
vput16bits(write_buffer, it->qClass);
}
// llarp::LogInfo("Questions finished at ", write_buffer.size());
// llarp::LogDebug("Starting answers for ", in.questions[0]->name);
for(auto &it : in.answers)
{
// code answers
@ -273,8 +266,6 @@ packet2bytes(dns_packet &in)
vput32bits(write_buffer, 1); // ttl
dns_writeType(write_buffer, it->record.get());
}
// llarp::LogDebug("Done with answers");
// llarp::LogInfo("Answers finished at ", write_buffer.size());
for(auto &it : in.auth_rrs)
{
@ -318,13 +309,24 @@ extern "C"
}
dns_msg_header *
decode_hdr(const char *buffer)
decode_hdr(llarp_buffer_t &buffer)
{
dns_msg_header *hdr = new dns_msg_header;
hdr->id = get16bits(buffer);
uint16_t fields = get16bits(buffer);
uint16_t fields;
// reads as network byte order
llarp_buffer_read_uint16(&buffer, &hdr->id);
llarp_buffer_read_uint16(&buffer, &fields);
llarp_buffer_read_uint16(&buffer, &hdr->qdCount);
llarp_buffer_read_uint16(&buffer, &hdr->anCount);
llarp_buffer_read_uint16(&buffer, &hdr->nsCount);
llarp_buffer_read_uint16(&buffer, &hdr->arCount);
// decode fields into hdr
uint8_t lFields = (fields & 0x00FF) >> 0;
uint8_t hFields = (fields & 0xFF00) >> 8;
// process high byte
// hdr->qr = fields & 0x8000;
hdr->qr = (hFields >> 7) & 0x1;
hdr->opcode = fields & 0x7800;
@ -332,68 +334,32 @@ extern "C"
hdr->tc = fields & 0x0200;
hdr->rd = fields & 0x0100;
// process low byte
hdr->ra = (lFields >> 7) & 0x1;
hdr->z = (lFields >> 6) & 0x1;
hdr->ad = (lFields >> 5) & 0x1;
hdr->cd = (lFields >> 4) & 0x1;
hdr->rcode = lFields & 0xf;
hdr->qdCount = get16bits(buffer);
hdr->anCount = get16bits(buffer);
hdr->nsCount = get16bits(buffer);
hdr->arCount = get16bits(buffer);
return hdr;
}
dns_msg_question *
decode_question(const char *buffer, uint32_t *pos)
{
// char *start = (char *)buffer;
dns_msg_question *question = new dns_msg_question;
// uint32_t start = *pos;
std::string m_qName = getDNSstring(buffer, pos);
llarp::LogDebug("Got question name: ", m_qName);
// llarp::LogInfo("Started at ", std::to_string(start), " ended at: ",
// std::to_string(*pos)); llarp::LogInfo("Advancing question buffer by ",
// std::to_string(*pos)); buffer += (*pos) - start; buffer +=
// m_qName.length() + 2; // + length byte & ending terminator
const char *moveable = buffer;
moveable += *pos; // advance to position
// hexDump(moveable, 4);
// printf("Now0 at [%d]\n", buffer - start);
// buffer += m_qName.size() + 1;
/*
std::string m_qName = "";
int length = *buffer++;
// llarp::LogInfo("qNamLen", length);
while(length != 0)
{
for(int i = 0; i < length; i++)
{
char c = *buffer++;
m_qName.append(1, c);
}
length = *buffer++;
if(length != 0)
m_qName.append(1, '.');
}
*/
question->name = m_qName;
question->type = get16bits(moveable);
(*pos) += 2;
// printf("Now1 at [%d]\n", buffer - start);
question->qClass = get16bits(moveable);
(*pos) += 2;
// printf("Now2 at [%d]\n", buffer - start);
/*
llarp::LogDebug("Type ", std::to_string(question->type), " Class ",
std::to_string(question->qClass));
*/
// hexDump(moveable, 4);
return question;
}
@ -493,8 +459,8 @@ extern "C"
*/
moveable += answer->rdLen;
(*pos) += answer->rdLen; // advance the length
answer->record.reset(new llarp::dns::type_1a());
answer->record = std::make_unique< llarp::dns::type_1a >();
answer->record->parse(answer->rData);
}
else
@ -503,7 +469,7 @@ extern "C"
// FIXME: move this out of here, this shouldn't be responsible for decode
switch(answer->type)
{
case 2: // NS
case LLARP_DNS_RECTYPE_NS: // NS
{
std::string ns = getDNSstring(buffer, pos);
answer->rData.resize(ns.size());
@ -513,12 +479,12 @@ extern "C"
// don't really need to do anything here
moveable += answer->rdLen;
//(*pos) += answer->rdLen; // advance the length
answer->record.reset(new llarp::dns::type_2ns());
answer->record = std::make_unique< llarp::dns::type_2ns >();
answer->record->parse(answer->rData);
}
break;
case 5: // CNAME
case LLARP_DNS_RECTYPE_CNAME: // CNAME
{
std::string cname = getDNSstring(buffer, pos);
llarp::LogDebug("CNAME ", cname);
@ -527,12 +493,12 @@ extern "C"
moveable += answer->rdLen;
//(*pos) += answer->rdLen; // advance the length
answer->record.reset(new llarp::dns::type_5cname());
answer->record = std::make_unique< llarp::dns::type_5cname >();
answer->record->parse(answer->rData);
}
break;
case 6: // type 6 = SOA
case LLARP_DNS_RECTYPE_SOA: // type 6 = SOA
{
// 2 names, then 4x 32bit
// why risk any crashes
@ -560,7 +526,7 @@ extern "C"
(*pos) += answer->rdLen; // advance the length
}
break;
case 12:
case LLARP_DNS_RECTYPE_PTR:
{
std::string revname = getDNSstring(buffer, pos);
llarp::LogInfo("revDNSname: ", revname);
@ -571,11 +537,11 @@ extern "C"
moveable += answer->rdLen;
//(*pos) += answer->rdLen; // advance the length
answer->record.reset(new llarp::dns::type_12ptr());
answer->record = std::make_unique< llarp::dns::type_12ptr >();
answer->record->parse(answer->rData);
}
break;
case 15:
case LLARP_DNS_RECTYPE_MX:
{
uint16_t priority = get16bits(moveable);
(*pos) += 2;
@ -590,11 +556,11 @@ extern "C"
// hexDumpAt(buffer, *pos, 5);
// hexDump(moveable, 5);
answer->record.reset(new llarp::dns::type_15mx());
answer->record = std::make_unique< llarp::dns::type_15mx >();
answer->record->parse(answer->rData);
}
break;
case 16:
case LLARP_DNS_RECTYPE_TXT:
{
// hexDump(buffer, 5);
// std::string revname = getDNSstring((char *)buffer);
@ -604,7 +570,7 @@ extern "C"
moveable += answer->rdLen;
(*pos) += answer->rdLen; // advance the length
answer->record.reset(new llarp::dns::type_16txt());
answer->record = std::make_unique< llarp::dns::type_16txt >();
answer->record->parse(answer->rData);
}
break;
@ -638,10 +604,14 @@ extern "C"
const struct sockaddr *addr, const void *buf,
ssize_t sz)
{
unsigned char *castBuf = (unsigned char *)buf;
// auto buffer = llarp::StackBuffer< decltype(castBuf) >(castBuf);
dns_msg_header *hdr = decode_hdr((const char *)castBuf);
// castBuf += 12;
//auto abuffer = llarp::StackBuffer< decltype(buf) >(buf);
llarp_buffer_t buffer;
buffer.base = (byte_t *)buf;
buffer.cur = buffer.base;
buffer.sz = sz;
dns_msg_header *hdr = decode_hdr(buffer);
llarp::LogDebug("msg id ", hdr->id);
llarp::LogDebug("msg qr ", (uint8_t)hdr->qr);
if(!udp)
@ -663,23 +633,5 @@ extern "C"
llarp_handle_dnsd_recvfrom(udp, addr, buf, sz);
}
delete hdr;
/*
llarp::LogInfo("msg op ", hdr->opcode);
llarp::LogInfo("msg rc ", hdr->rcode);
for(uint8_t i = 0; i < hdr->qdCount; i++)
{
dns_msg_question *question = decode_question((const char*)castBuf);
llarp::LogInfo("Read a question");
castBuf += question->name.length() + 8;
}
for(uint8_t i = 0; i < hdr->anCount; i++)
{
dns_msg_answer *answer = decode_answer((const char*)castBuf);
llarp::LogInfo("Read an answer");
castBuf += answer->name.length() + 4 + 4 + 4 + answer->rdLen;
}
*/
}
}

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