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-rw-r--r--include/dns.h44
-rw-r--r--src/dns.cpp153
2 files changed, 154 insertions, 43 deletions
diff --git a/include/dns.h b/include/dns.h
index 9d6f161df..7b96f792d 100644
--- a/include/dns.h
+++ b/include/dns.h
@@ -88,6 +88,25 @@ typedef std::map<int,DNSRequest*> requestlist;
typedef requestlist::iterator requestlist_iter;
/**
+ * Query and resource record types
+ */
+enum QueryType
+{
+ DNS_QUERY_A = 1, /* 'A' record: an ipv4 address */
+ DNS_QUERY_CNAME = 5, /* 'CNAME' record: An alias */
+ DNS_QUERY_PTR = 12, /* 'PTR' record: a hostname */
+ DNS_QUERY_AAAA = 28, /* 'AAAA' record: an ipv6 address */
+};
+
+#ifdef IPV6
+const QueryType DNS_QUERY_FORWARD = DNS_QUERY_AAAA;
+const QueryType DNS_QUERY_REVERSE = DNS_QUERY_PTR;
+#else
+const QueryType DNS_QUERY_FORWARD = DNS_QUERY_A;
+const QueryType DNS_QUERY_REVERSE = DNS_QUERY_PTR;
+#endif
+
+/**
* The Resolver class is a high-level abstraction for resolving DNS entries.
* It can do forward and reverse IPv4 lookups, and where IPv6 is supported, will
* also be able to do those, transparent of protocols. Module developers must
@@ -107,7 +126,7 @@ class Resolver : public Extensible
/**
* True if a forward lookup is being performed, false if otherwise
*/
- bool fwd;
+ QueryType querytype;
/**
* The DNS erver being used for lookups. If this is an empty string,
* the value of ServerConfig::DNSServer is used instead.
@@ -137,7 +156,7 @@ class Resolver : public Extensible
* event a lookup could not be allocated, or a similar hard error occurs such as
* the network being down.
*/
- Resolver(const std::string &source, bool forward);
+ Resolver(const std::string &source, QueryType qt);
/**
* The default destructor does nothing.
*/
@@ -165,15 +184,6 @@ class Resolver : public Extensible
int GetId();
};
-/**
- * Query and resource record types
- */
-enum QueryType
-{
- DNS_QUERY_A = 1, /* 'A' record: an IP address */
- DNS_QUERY_PTR = 12 /* 'PTR' record: a hostname */
-};
-
/** DNS is a singleton class used by the core to dispatch dns
* requests to the dns server, and route incoming dns replies
* back to Resolver objects, based upon the request ID. You
@@ -244,7 +254,7 @@ class DNS : public Extensible
static int GetMasterSocket();
/**
- * Start the lookup of an ip from a hostname
+ * Start the lookup of an ipv4 from a hostname
*/
int GetIP(const char* name);
@@ -254,6 +264,16 @@ class DNS : public Extensible
int GetName(const insp_inaddr* ip);
/**
+ * Start lookup of an ipv6 from a hostname
+ */
+ int GetIP6(const char *name);
+
+ /**
+ * Start lookup of a CNAME from another hostname
+ */
+ int GetCName(const char* alias);
+
+ /**
* Fetch the result string (an ip or host)
* and/or an error message to go with it.
*/
diff --git a/src/dns.cpp b/src/dns.cpp
index 1ce68f186..2980a2502 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -360,6 +360,42 @@ int DNS::GetIP(const char *name)
return id;
}
+/* Start lookup of an hostname to an IPv6 address */
+int DNS::GetIP6(const char *name)
+{
+ DNSHeader h;
+ int id;
+ int length;
+
+ if ((length = this->MakePayload(name, DNS_QUERY_AAAA, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
+
+ DNSRequest* req = this->AddQuery(&h, id);
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_AAAA) == -1))
+ return -1;
+
+ return id;
+}
+
+/* Start lookup of a cname to another name */
+int DNS::GetCName(const char *alias)
+{
+ DNSHeader h;
+ int id;
+ int length;
+
+ if ((length = this->MakePayload(alias, DNS_QUERY_CNAME, 1, (unsigned char*)&h.payload)) == -1)
+ return -1;
+
+ DNSRequest* req = this->AddQuery(&h, id);
+
+ if ((!req) || (req->SendRequests(&h, length, DNS_QUERY_CNAME) == -1))
+ return -1;
+
+ return id;
+}
+
/* Start lookup of an IP address to a hostname */
int DNS::GetName(const insp_inaddr *ip)
{
@@ -471,17 +507,53 @@ DNSResult DNS::GetResult()
}
else
{
+ char formatted[128];
+
/* Forward lookups come back as binary data. We must format them into ascii */
- if (req->type == DNS_QUERY_A)
+ switch (req->type)
{
- char formatted[16];
- snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]);
- resultstr = formatted;
- }
- else
- {
- /* Reverse lookups just come back as char* */
- resultstr = std::string((const char*)data.first);
+ case DNS_QUERY_A:
+ snprintf(formatted,16,"%u.%u.%u.%u",data.first[0],data.first[1],data.first[2],data.first[3]);
+ resultstr = formatted;
+ break;
+
+ case DNS_QUERY_AAAA:
+ {
+ in6_addr* ip = (in6_addr*)&data.first;
+
+ snprintf(formatted,40,"%x:%x:%x:%x:%x:%x:%x:%x",
+ ntohs(*((unsigned short *)&ip->s6_addr[0])),
+ ntohs(*((unsigned short *)&ip->s6_addr[2])),
+ ntohs(*((unsigned short *)&ip->s6_addr[4])),
+ ntohs(*((unsigned short *)&ip->s6_addr[6])),
+ ntohs(*((unsigned short *)&ip->s6_addr[8])),
+ ntohs(*((unsigned short *)&ip->s6_addr[10])),
+ ntohs(*((unsigned short *)&ip->s6_addr[12])),
+ ntohs(*((unsigned short *)&ip->s6_addr[14])));
+ char* c = strstr(formatted,":0:");
+ if (c != NULL)
+ {
+ memmove(c+1,c+2,strlen(c+2) + 1);
+ c += 2;
+ while (memcmp(c,"0:",2) == 0)
+ memmove(c,c+2,strlen(c+2) + 1);
+ if (memcmp(c,"0",2) == 0)
+ *c = 0;
+ if (memcmp(formatted,"0::",3) == 0)
+ memmove(formatted,formatted + 1, strlen(formatted + 1) + 1);
+ }
+ resultstr = formatted;
+ }
+ break;
+
+ case DNS_QUERY_CNAME:
+ /* Identical handling to PTR */
+
+ case DNS_QUERY_PTR:
+ /* Reverse lookups just come back as char* */
+ resultstr = std::string((const char*)data.first);
+ break;
+
}
/* Build the reply with the id and hostname/ip in it */
@@ -582,6 +654,8 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
switch (rr.type)
{
+ case DNS_QUERY_CNAME:
+ /* CNAME and PTR have the same processing code */
case DNS_QUERY_PTR:
o = 0;
q = 0;
@@ -611,14 +685,18 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
}
res[o] = 0;
break;
+ case DNS_QUERY_AAAA:
+ memcpy(res,&header.payload[i],rr.rdlength);
+ res[rr.rdlength] = 0;
+ break;
case DNS_QUERY_A:
memcpy(res,&header.payload[i],rr.rdlength);
res[rr.rdlength] = 0;
- break;
+ break;
default:
memcpy(res,&header.payload[i],rr.rdlength);
res[rr.rdlength] = 0;
- break;
+ break;
}
return std::make_pair(res,"No error");;
}
@@ -631,28 +709,41 @@ DNS::~DNS()
}
/* High level abstraction of dns used by application at large */
-Resolver::Resolver(const std::string &source, bool forward) : input(source), fwd(forward)
+Resolver::Resolver(const std::string &source, QueryType qt) : input(source), querytype(qt)
{
- if (forward)
- {
- log(DEBUG,"Resolver: Forward lookup on %s",source.c_str());
- this->myid = ServerInstance->Res->GetIP(source.c_str());
- }
- else
+ insp_inaddr binip;
+
+ switch (querytype)
{
- log(DEBUG,"Resolver: Reverse lookup on %s",source.c_str());
- insp_inaddr binip;
- if (insp_aton(source.c_str(), &binip) > 0)
- {
- /* Valid ip address */
- this->myid = ServerInstance->Res->GetName(&binip);
- }
- else
- {
- this->OnError(RESOLVER_BADIP, "Bad IP address for reverse lookup");
- throw ModuleException("Resolver: Bad IP address");
- return;
- }
+ case DNS_QUERY_A:
+ this->myid = ServerInstance->Res->GetIP(source.c_str());
+ break;
+
+ case DNS_QUERY_PTR:
+ if (insp_aton(source.c_str(), &binip) > 0)
+ {
+ /* Valid ip address */
+ this->myid = ServerInstance->Res->GetName(&binip);
+ }
+ else
+ {
+ this->OnError(RESOLVER_BADIP, "Bad IP address for reverse lookup");
+ throw ModuleException("Resolver: Bad IP address");
+ return;
+ }
+ break;
+
+ case DNS_QUERY_AAAA:
+ this->myid = ServerInstance->Res->GetIP6(source.c_str());
+ break;
+
+ case DNS_QUERY_CNAME:
+ this->myid = ServerInstance->Res->GetCName(source.c_str());
+ break;
+
+ default:
+ this->myid = -1;
+ break;
}
if (this->myid == -1)
{
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 14:26:28 +0000