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add some stats to tres plus detect hosts that don't respond

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This commit is contained in:
bert hubert
2018-11-02 11:47:31 +01:00
parent 4b10e5c9b9
commit 947908cb56
1 changed files with 21 additions and 2 deletions
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23
tdns/tres.cc
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@ -91,6 +91,9 @@ private:
}
public:
unsigned int d_numqueries{0};
unsigned int d_numtimeouts{0};
unsigned int d_numformerrs{0};
};
/** Helper function that extracts a useable IP address from an
@ -119,9 +122,15 @@ static ComboAddress getIP(const std::unique_ptr<RRGen>& rr)
*/
DNSMessageReader TDNSResolver::getResponse(const ComboAddress& server, const DNSName& dn, const DNSType& dt, int depth)
{
static set<std::tuple<ComboAddress, DNSName, DNSType>> skips;
std::string prefix(depth, ' ');
prefix += dn.toString() + "|"+toString(dt)+" ";
if(skips.count({server,dn,dt})) {
throw std::runtime_error("Skipping query to "+server.toString()+": failed before");
}
bool doEDNS=true, doTCP=false;
for(int tries = 0; tries < 4 ; ++tries) {
@ -147,6 +156,7 @@ DNSMessageReader TDNSResolver::getResponse(const ComboAddress& server, const DNS
int err = waitForData(sock, &timeout);
if( err <= 0) {
if(!err) d_numtimeouts++;
throw std::runtime_error("Error waiting for data from "+server.toStringWithPort()+": "+ (err ? string(strerror(errno)): string("Timeout")));
}
@ -157,6 +167,7 @@ DNSMessageReader TDNSResolver::getResponse(const ComboAddress& server, const DNS
err = waitForData(sock, &timeout);
if( err <= 0) {
if(!err) d_numtimeouts++;
throw std::runtime_error("Error waiting for data from "+server.toStringWithPort()+": "+ (err ? string(strerror(errno)): string("Timeout")));
}
// and even this is not good enough, an authoritative server could be trickling us bytes
@ -171,6 +182,9 @@ DNSMessageReader TDNSResolver::getResponse(const ComboAddress& server, const DNS
// so one could simply retry on a timeout, but here we don't
if( err <= 0) {
skips.insert({server,dn,dt});
if(!err) d_numtimeouts++;
throw std::runtime_error("Error waiting for data from "+server.toStringWithPort()+": "+ (err ? string(strerror(errno)): string("Timeout")));
}
ComboAddress ign=server;
@ -188,6 +202,7 @@ DNSMessageReader TDNSResolver::getResponse(const ComboAddress& server, const DNS
if((RCode)dmr.dh.rcode == RCode::Formerr) { // XXX this should check that there is no OPT in the response
lstream() << prefix <<"Got a Formerr, resending without EDNS"<<endl;
doEDNS=false;
d_numformerrs++;
continue;
}
if(dmr.dh.tc) {
@ -597,7 +612,8 @@ try
nlohmann::json jres;
jres["name"]=dn.toString();
jres["type"]=toString(dt);
jres["intermediate"]= nlohmann::json::array();
jres["intermediate"]= nlohmann::json::array();
jres["answer"]= nlohmann::json::array();
try {
tdr.createPlot("plot.dot");
// ofstream devnull;
@ -635,9 +651,12 @@ try
{
cout<<argv[1]<< ": exceeded maximum number of queries (" << tdr.d_numqueries<<")"<<endl;
rc= EXIT_FAILURE;
jres["rcode"]=2;
}
jres["numqueries"]=tdr.d_numqueries;
jres["numtimeouts"]=tdr.d_numtimeouts;
jres["numformerrs"]=tdr.d_numformerrs;
cout << jres << endl;
std::vector<std::uint8_t> v_cbor = nlohmann::json::to_cbor(jres);
FILE* out = fopen("cbor", "w");