From 2f10e3ad86390ab452c2c3a2128c41d515f76e7d Mon Sep 17 00:00:00 2001 From: jet2tlf Date: Mon, 3 Jun 2024 03:10:24 -0300 Subject: codecrafters submit [skip ci] --- app/forwarder.go | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 app/forwarder.go (limited to 'app/forwarder.go') diff --git a/app/forwarder.go b/app/forwarder.go new file mode 100644 index 0000000..c4eac58 --- /dev/null +++ b/app/forwarder.go @@ -0,0 +1,60 @@ +package main + +import ( + "fmt" + "net" +) + +func ForwardQuestions(addr string, questions []DNSQuestion, id uint16) []DNSAnswer { + answers := []DNSAnswer{} + + udpConn, err := net.Dial("udp", addr) + if err != nil { + fmt.Println("Failed to connect to address:", err) + return answers + } + + defer udpConn.Close() + + for _, question := range questions { + questionBytes := question.Bytes() + + header := DNSHeader{ + ID: id, + QR: 0, + OPCODE: 0, + AA: 0, + TC: 0, + RD: 1, + RA: 0, + Z: 0, + RCODE: 0, + QDCOUNT: 1, + ANCOUNT: 0, + NSCOUNT: 0, + ARCOUNT: 0, + } + + headerBytes := header.Bytes() + buf := append(headerBytes, questionBytes...) + + _, err = udpConn.Write(buf) + if err != nil { + fmt.Println("Failed to send data:", err) + return answers + } + + responseBuf := make([]byte, 512) + + n, err := udpConn.Read(responseBuf) + if err != nil { + fmt.Println("Failed to receive data:", err) + return answers + } + + responseHeader := ParseHeader(responseBuf[:n]) + answers = append(answers, ParseAnswers(responseBuf[:n], responseHeader.QDCOUNT, responseHeader.ANCOUNT)...) + } + + return answers +} -- cgit v1.2.3