#ifndef PACKETCACHE_HH
#define PACKETCACHE_HH
-#include <string>
-#include <utility>
-#include <map>
-#include <map>
-#include "dns.hh"
-#include <boost/version.hpp>
-#include "namespaces.hh"
-using namespace ::boost::multi_index;
-
-#include "namespaces.hh"
-#include "dnspacket.hh"
-#include "lock.hh"
-#include "statbag.hh"
-
-/** This class performs 'whole packet caching'. Feed it a question packet and it will
- try to find an answer. If you have an answer, insert it to have it cached for later use.
- Take care not to replace existing cache entries. While this works, it is wasteful. Only
- insert packets that where not found by get()
-
- Locking!
-
- The cache itself is protected by a read/write lock. Because deleting is a two step process, which
- first marks and then sweeps, a second lock is present to prevent simultaneous inserts and deletes.
-*/
+#include "ednsoptions.hh"
+#include "misc.hh"
+#include "iputils.hh"
class PacketCache : public boost::noncopyable
{
public:
- PacketCache();
- ~PacketCache();
- enum CacheEntryType { PACKETCACHE, QUERYCACHE};
-
- void insert(DNSPacket *q, DNSPacket *r, bool recursive, unsigned int maxttl=UINT_MAX); //!< We copy the contents of *p into our cache. Do not needlessly call this to insert questions already in the cache as it wastes resources
+ static uint32_t canHashPacket(const std::string& packet, uint16_t* ecsBegin, uint16_t* ecsEnd)
+ {
+ uint32_t ret = 0;
+ ret = burtle(reinterpret_cast<const unsigned char*>(packet.c_str()) + 2, sizeof(dnsheader) - 2, ret); // rest of dnsheader, skip id
+ size_t packetSize = packet.size();
+ size_t pos = sizeof(dnsheader);
+ const char* end = packet.c_str() + packetSize;
+ const char* p = packet.c_str() + pos;
+
+ for(; p < end && *p; ++p, ++pos) { // XXX if you embed a 0 in your qname we'll stop lowercasing there
+ const unsigned char l = dns_tolower(*p); // label lengths can safely be lower cased
+ ret=burtle(&l, 1, ret);
+ } // XXX the embedded 0 in the qname will break the subnet stripping
+
+ const struct dnsheader* dh = reinterpret_cast<const struct dnsheader*>(packet.c_str());
+ const char* skipBegin = p;
+ const char* skipEnd = p;
+ if (ecsBegin != nullptr && ecsEnd != nullptr) {
+ *ecsBegin = 0;
+ *ecsEnd = 0;
+ }
+ /* we need at least 1 (final empty label) + 2 (QTYPE) + 2 (QCLASS)
+ + OPT root label (1), type (2), class (2) and ttl (4)
+ + the OPT RR rdlen (2)
+ = 16
+ */
+ if(ntohs(dh->arcount)==1 && (pos+16) < packetSize) {
+ char* optionBegin = nullptr;
+ size_t optionLen = 0;
+ /* skip the final empty label (1), the qtype (2), qclass (2) */
+ /* root label (1), type (2), class (2) and ttl (4) */
+ int res = getEDNSOption(const_cast<char*>(reinterpret_cast<const char*>(p)) + 14, end - (p + 14), EDNSOptionCode::ECS, &optionBegin, &optionLen);
+ if (res == 0) {
+ skipBegin = optionBegin;
+ skipEnd = optionBegin + optionLen;
+ if (ecsBegin != nullptr && ecsEnd != nullptr) {
+ *ecsBegin = optionBegin - packet.c_str();
+ *ecsEnd = *ecsBegin + optionLen;
+ }
+ }
+ }
+ if (skipBegin > p) {
+ ret = burtle(reinterpret_cast<const unsigned char*>(p), skipBegin-p, ret);
+ }
+ if (skipEnd < end) {
+ ret = burtle(reinterpret_cast<const unsigned char*>(skipEnd), end-skipEnd, ret);
+ }
- void insert(const DNSName &qname, const QType& qtype, CacheEntryType cet, const string& value, unsigned int ttl, int zoneID=-1, bool meritsRecursion=false,
- unsigned int maxReplyLen=512, bool dnssecOk=false, bool EDNS=false);
+ return ret;
+ }
- void insert(const DNSName &qname, const QType& qtype, CacheEntryType cet, const vector<DNSResourceRecord>& content, unsigned int ttl, int zoneID=-1);
+ static uint32_t canHashPacket(const std::string& packet)
+ {
+ uint32_t ret = 0;
+ ret = burtle(reinterpret_cast<const unsigned char*>(packet.c_str()) + 2, sizeof(dnsheader) - 2, ret); // rest of dnsheader, skip id
+ size_t packetSize = packet.size();
+ size_t pos = sizeof(dnsheader);
+ const char* end = packet.c_str() + packetSize;
+ const char* p = packet.c_str() + pos;
+
+ for(; p < end && *p; ++p) { // XXX if you embed a 0 in your qname we'll stop lowercasing there
+ const unsigned char l = dns_tolower(*p); // label lengths can safely be lower cased
+ ret=burtle(&l, 1, ret);
+ } // XXX the embedded 0 in the qname will break the subnet stripping
+
+ if (p < end) {
+ ret = burtle(reinterpret_cast<const unsigned char*>(p), end-p, ret);
+ }
- int get(DNSPacket *p, DNSPacket *q, bool recursive); //!< We return a dynamically allocated copy out of our cache. You need to delete it. You also need to spoof in the right ID with the DNSPacket.spoofID() method.
- bool getEntry(const DNSName &qname, const QType& qtype, CacheEntryType cet, string& entry, int zoneID=-1,
- bool meritsRecursion=false, unsigned int maxReplyLen=512, bool dnssecOk=false, bool hasEDNS=false, unsigned int *age=0);
- bool getEntry(const DNSName &qname, const QType& qtype, CacheEntryType cet, vector<DNSResourceRecord>& entry, int zoneID=-1);
-
+ return ret;
+ }
- int size(); //!< number of entries in the cache
- void cleanupIfNeeded()
+ static bool queryHeaderMatches(const std::string& cachedQuery, const std::string& query)
{
- if(!(++d_ops % 300000)) {
- if(d_lastclean + 30 < time(0)) {
- d_lastclean=time(0);
- cleanup();
- }
+ if (cachedQuery.size() != query.size()) {
+ return false;
}
+
+ return (cachedQuery.compare(/* skip the ID */ 2, sizeof(dnsheader) - 2, query, 2, sizeof(dnsheader) - 2) == 0);
}
- void cleanup(); //!< force the cache to preen itself from expired packets
- int purge();
- int purge(const std::string& match); // could be $ terminated. Is not a dnsname!
- int purgeExact(const DNSName& qname); // no wildcard matching here
- map<char,int> getCounts();
-private:
- bool getEntryLocked(const DNSName &content, const QType& qtype, CacheEntryType cet, string& entry, int zoneID=-1,
- bool meritsRecursion=false, unsigned int maxReplyLen=512, bool dnssecOk=false, bool hasEDNS=false, unsigned int *age=0);
- bool getEntryLocked(const DNSName &content, const QType& qtype, CacheEntryType cet, vector<DNSResourceRecord>& entry, int zoneID=-1);
+ static bool queryMatches(const std::string& cachedQuery, const std::string& query, const DNSName& qname)
+ {
+ if (!queryHeaderMatches(cachedQuery, query)) {
+ return false;
+ }
+ size_t pos = sizeof(dnsheader) + qname.wirelength();
- struct CacheEntry
- {
- CacheEntry() { qtype = ctype = 0; zoneID = -1; meritsRecursion=false; dnssecOk=false; hasEDNS=false; created=0; ttd=0; maxReplyLen=512;}
-
- DNSName qname;
- string value;
- vector<DNSResourceRecord> drs;
- time_t created;
- time_t ttd;
-
- uint16_t qtype;
- uint16_t ctype;
- int zoneID;
- unsigned int maxReplyLen;
-
- bool meritsRecursion;
- bool dnssecOk;
- bool hasEDNS;
- };
-
- void getTTLS();
-
- typedef multi_index_container<
- CacheEntry,
- indexed_by <
- ordered_unique<
- composite_key<
- CacheEntry,
- member<CacheEntry,DNSName,&CacheEntry::qname>,
- member<CacheEntry,uint16_t,&CacheEntry::qtype>,
- member<CacheEntry,uint16_t, &CacheEntry::ctype>,
- member<CacheEntry,int, &CacheEntry::zoneID>,
- member<CacheEntry,bool, &CacheEntry::meritsRecursion>,
- member<CacheEntry,unsigned int, &CacheEntry::maxReplyLen>,
- member<CacheEntry,bool, &CacheEntry::dnssecOk>,
- member<CacheEntry,bool, &CacheEntry::hasEDNS>
- >,
- composite_key_compare<CanonDNSNameCompare, std::less<uint16_t>, std::less<uint16_t>, std::less<int>, std::less<bool>,
- std::less<unsigned int>, std::less<bool>, std::less<bool> >
- >,
- sequenced<>
- >
- > cmap_t;
-
-
- struct MapCombo
- {
- pthread_rwlock_t d_mut;
- cmap_t d_map;
- };
+ return (cachedQuery.compare(pos, cachedQuery.size() - pos, query, pos, query.size() - pos) == 0);
+ }
- vector<MapCombo> d_maps;
- MapCombo& getMap(const DNSName& qname)
+ static bool queryMatches(const std::string& cachedQuery, const std::string& query, const DNSName& qname, uint16_t ecsBegin, uint16_t ecsEnd)
{
- return d_maps[qname.hash() % d_maps.size()];
- }
+ if (!queryHeaderMatches(cachedQuery, query)) {
+ return false;
+ }
- AtomicCounter d_ops;
- time_t d_lastclean{0}; // doesn't need to be atomic
- AtomicCounter *d_statnumhit;
- AtomicCounter *d_statnummiss;
- AtomicCounter *d_statnumentries;
+ size_t pos = sizeof(dnsheader) + qname.wirelength();
- int d_ttl;
- int d_recursivettl;
- bool d_doRecursion;
-};
+ if (ecsBegin != 0 && ecsBegin >= pos && ecsEnd > ecsBegin) {
+ if (cachedQuery.compare(pos, ecsBegin - pos, query, pos, ecsBegin - pos) != 0) {
+ return false;
+ }
+ if (cachedQuery.compare(ecsEnd, cachedQuery.size() - ecsEnd, query, ecsEnd, query.size() - ecsEnd) != 0) {
+ return false;
+ }
+ }
+ else {
+ if (cachedQuery.compare(pos, cachedQuery.size() - pos, query, pos, query.size() - pos) != 0) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+};
#endif /* PACKETCACHE_HH */
projects / thirdparty / pdns.git / blobdiff