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-rw-r--r--src/dns.cpp93
1 files changed, 47 insertions, 46 deletions
diff --git a/src/dns.cpp b/src/dns.cpp
index 60318dcc3..b82e705cd 100644
--- a/src/dns.cpp
+++ b/src/dns.cpp
@@ -135,14 +135,6 @@ class DNSRequest
int SendRequests(const DNSHeader *header, const int length, QueryType qt);
};
-/*
- * Optimized by brain, these were using integer division and modulus.
- * We can use logic shifts and logic AND to replace these even divisions
- * and multiplications, it should be a bit faster (probably not noticably,
- * but of course, more impressive). Also made these inline.
- */
-
-
/* Fill a ResourceRecord class based on raw data input */
inline void DNS::FillResourceRecord(ResourceRecord* rr, const unsigned char *input)
{
@@ -244,25 +236,37 @@ int DNS::GetMasterSocket()
/* Initialise the DNS UDP socket so that we can send requests */
DNS::DNS()
{
- log(DEBUG,"----- Initialize dns class ----- ");
- memset(Classes,0,sizeof(Classes));
insp_inaddr addr;
+
+ /* Clear the Resolver class table */
+ memset(Classes,0,sizeof(Classes));
+
+ /* Seed random number generator, we use this to generate
+ * dns packet id's
+ */
srand((unsigned int)time(NULL));
+
+ /* Clear the namesever address */
memset(&myserver,0,sizeof(insp_inaddr));
+
+ /* Convert the nameserver address into an insp_inaddr */
if (insp_aton(Config->DNSServer,&addr) > 0)
memcpy(&myserver,&addr,sizeof(insp_inaddr));
+ /* Initialize mastersocket */
MasterSocket = socket(PF_PROTOCOL, SOCK_DGRAM, 0);
if (MasterSocket != -1)
{
- log(DEBUG,"Set query socket nonblock");
+ /* Did it succeed? */
if (fcntl(MasterSocket, F_SETFL, O_NONBLOCK) != 0)
{
+ /* Couldn't make the socket nonblocking */
shutdown(MasterSocket,2);
close(MasterSocket);
MasterSocket = -1;
}
}
+ /* Have we got a socket and is it nonblocking? */
if (MasterSocket != -1)
{
#ifdef IPV6
@@ -278,10 +282,11 @@ DNS::DNS()
addr.sin_port = 0;
addr.sin_addr.s_addr = INADDR_ANY;
#endif
- log(DEBUG,"Binding query port");
+ /* Bind the port */
if (bind(MasterSocket,(sockaddr *)&addr,sizeof(addr)) != 0)
{
- log(DEBUG,"Cant bind with source port = 0");
+ /* Failed to bind */
+ log(DEBUG,"Cant bind DNS::MasterSocket");
shutdown(MasterSocket,2);
close(MasterSocket);
MasterSocket = -1;
@@ -289,63 +294,61 @@ DNS::DNS()
if (MasterSocket >= 0)
{
- log(DEBUG,"Attach query port to socket engine");
+ /* Hook the descriptor into the socket engine */
if (ServerInstance && ServerInstance->SE)
ServerInstance->SE->AddFd(MasterSocket,true,X_ESTAB_DNS);
}
}
}
+/* Build a payload to be placed after the header, based upon input data, a resource type, a class and a pointer to a buffer */
int DNS::MakePayload(const char * const name, const unsigned short rr, const unsigned short rr_class, unsigned char * const payload)
{
- short payloadpos;
- const char * tempchr, * tempchr2;
- unsigned short l;
-
- payloadpos = 0;
- tempchr2 = name;
+ short payloadpos = 0;
+ const char* tempchr, *tempchr2 = name;
+ unsigned short length;
/* split name up into labels, create query */
while ((tempchr = strchr(tempchr2,'.')) != NULL)
{
- l = tempchr - tempchr2;
- if (payloadpos + l + 1 > 507)
+ length = tempchr - tempchr2;
+ if (payloadpos + length + 1 > 507)
return -1;
- payload[payloadpos++] = l;
- memcpy(&payload[payloadpos],tempchr2,l);
- payloadpos += l;
+ payload[payloadpos++] = length;
+ memcpy(&payload[payloadpos],tempchr2,length);
+ payloadpos += length;
tempchr2 = &tempchr[1];
}
- l = strlen(tempchr2);
- if (l)
+ length = strlen(tempchr2);
+ if (length)
{
- if (payloadpos + l + 2 > 507)
+ if (payloadpos + length + 2 > 507)
return -1;
- payload[payloadpos++] = l;
- memcpy(&payload[payloadpos],tempchr2,l);
- payloadpos += l;
+ payload[payloadpos++] = length;
+ memcpy(&payload[payloadpos],tempchr2,length);
+ payloadpos += length;
payload[payloadpos++] = 0;
}
if (payloadpos > 508)
return -1;
- l = htons(rr);
- memcpy(&payload[payloadpos],&l,2);
- l = htons(rr_class);
- memcpy(&payload[payloadpos + 2],&l,2);
+ length = htons(rr);
+ memcpy(&payload[payloadpos],&length,2);
+ length = htons(rr_class);
+ memcpy(&payload[payloadpos + 2],&length,2);
return payloadpos + 4;
}
+/* Start lookup of an hostname to an IP address */
int DNS::GetIP(const char *name)
{
DNSHeader h;
int id;
int length;
- DNSRequest* req;
if ((length = this->MakePayload(name,DNS_QRY_A,1,(unsigned char*)&h.payload)) == -1)
return -1;
- req = this->AddQuery(&h, id);
+ DNSRequest* req = this->AddQuery(&h, id);
if (req->SendRequests(&h,length,DNS_QRY_A) == -1)
return -1;
@@ -353,6 +356,7 @@ int DNS::GetIP(const char *name)
return id;
}
+/* Start lookup of an IP address to a hostname */
int DNS::GetName(const insp_inaddr *ip)
{
#ifdef IPV6
@@ -362,7 +366,6 @@ int DNS::GetName(const insp_inaddr *ip)
DNSHeader h;
int id;
int length;
- DNSRequest* req;
unsigned char* c = (unsigned char*)&ip->s_addr;
@@ -371,7 +374,7 @@ int DNS::GetName(const insp_inaddr *ip)
if ((length = this->MakePayload(query,DNS_QRY_PTR,1,(unsigned char*)&h.payload)) == -1)
return -1;
- req = this->AddQuery(&h, id);
+ DNSRequest* req = this->AddQuery(&h, id);
if (req->SendRequests(&h,length,DNS_QRY_PTR) == -1)
return -1;
@@ -380,18 +383,16 @@ int DNS::GetName(const insp_inaddr *ip)
#endif
}
-/* Return the next id which is ready, and the result attached to it
- */
+/* Return the next id which is ready, and the result attached to it */
DNSResult DNS::GetResult()
{
/* Fetch dns query response and decide where it belongs */
DNSHeader header;
DNSRequest *req;
- int length;
unsigned char buffer[sizeof(DNSHeader)];
/* Attempt to read a header */
- length = recv(MasterSocket,buffer,sizeof(DNSHeader),0);
+ int length = recv(MasterSocket,buffer,sizeof(DNSHeader),0);
/* Did we get the whole header? */
if (length < 12)
@@ -469,7 +470,7 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
int q = 0;
int curanswer, o;
ResourceRecord rr;
- unsigned short p;
+ unsigned short ptr;
if (!(header.flags1 & FLAGS_MASK_QR))
return std::make_pair((unsigned char*)NULL,"Not a query result");
@@ -561,8 +562,8 @@ DNSInfo DNSRequest::ResultIsReady(DNSHeader &header, int length)
{
if (header.payload[i] > 63)
{
- memcpy(&p,&header.payload[i],2);
- i = ntohs(p) - 0xC000 - 12;
+ memcpy(&ptr,&header.payload[i],2);
+ i = ntohs(ptr) - 0xC000 - 12;
}
else
{
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 00:11:21 +0000