netgiv/client.go

package main

import (
	"bufio"
	"bytes"
	"encoding/gob"
	"errors"
	"fmt"
	"io"
	"log"
	"net"
	"os"

	"github.com/tardisx/netgiv/secure"
)

type Client struct {
	address string
	port    int
	list    bool
	receive bool
}

func (c *Client) Connect() error {
	address := fmt.Sprintf("%s:%d", c.address, c.port)

	serverAddress, _ := net.ResolveTCPAddr("tcp", address)

	conn, err := net.DialTCP("tcp", nil, serverAddress)
	if err != nil {
		return errors.New("problem connecting to server, is it running?\n")
	}
	defer conn.Close()

	log.Printf("Connection on %s\n", address)

	sharedKey := secure.Handshake(conn)
	secureConnection := secure.SecureConnection{Conn: conn, SharedKey: sharedKey, Buffer: &bytes.Buffer{}}

	enc := gob.NewEncoder(&secureConnection)
	dec := gob.NewDecoder(&secureConnection)

	if c.list {
		log.Printf("requesting file list")
		// list mode
		msg := secure.PacketStart{
			OperationType:   secure.OperationTypeList,
			ClientName:      "Justin Hawkins",
			ProtocolVersion: "v1.0",
			AuthToken:       "abc123",
		}
		err := enc.Encode(msg)
		if err != nil {
			panic(err)
		}
		// now we expect to get stuff back until we don't
		for {
			listPacket := secure.PacketListData{}
			err := dec.Decode(&listPacket)
			if err == io.EOF {
				break
			}
			if err != nil {
				panic(err)
			}
			log.Printf("%d: %s (%d bytes)", listPacket.Id, listPacket.Kind, listPacket.FileSize)
		}
		conn.Close()
		log.Printf("done listing")

	} else if c.receive {
		log.Printf("receiving a file")
		// list mode
		msg := secure.PacketStart{
			OperationType:   secure.OperationTypeReceive,
			ClientName:      "Justin Hawkins",
			ProtocolVersion: "v1.0",
			AuthToken:       "abc123",
		}
		err := enc.Encode(msg)
		if err != nil {
			panic(err)
		}

		req := secure.PacketReceiveDataStartRequest{
			Id: 234,
		}
		err = enc.Encode(req)
		if err != nil {
			panic(err)
		}
		// expect a response telling us if we can go ahead
		res := secure.PacketReceiveDataStartResponse{}
		err = dec.Decode(&res)
		if err != nil {
			panic(err)
		}

		log.Printf("server said %v", res)
		if res.Status == secure.ReceiveDataStartResponseOK {
			for {
				res := secure.PacketReceiveDataNext{}
				err = dec.Decode(&res)
				if err != nil {
					panic(err)
				}
				// log.Printf("got %d bytes, last is %t", res.Size, res.Last)
				// print(res.Data)
				os.Stdout.Write(res.Data[:res.Size])
				if res.Last {
					break
				}
			}
			log.Printf("finished")
		} else {
			panic("don't handle this yet")
		}

		conn.Close()
	} else {
		// must be send mode

		msg := secure.PacketStart{
			OperationType:   secure.OperationTypeSend,
			ClientName:      "Justin Hawkins",
			ProtocolVersion: "v1.0",
			AuthToken:       "abc123",
		}

		// gob.Register(secure.PacketSendStart{})
		err := enc.Encode(msg)
		if err != nil {
			panic(err)
		}

		data := secure.PacketSendDataStart{
			Filename:  "",
			TotalSize: 0,
		}
		err = enc.Encode(data)
		if err != nil {
			panic(err)
		}

		nBytes, nChunks := int64(0), int64(0)
		reader := bufio.NewReader(os.Stdin)
		buf := make([]byte, 0, 1024)

		for {
			n, err := reader.Read(buf[:cap(buf)])

			buf = buf[:n]

			if n == 0 {
				if err == nil {
					continue
				}
				if err == io.EOF {
					break
				}
				log.Fatal(err)
			}
			nChunks++
			nBytes += int64(len(buf))

			send := secure.PacketSendDataNext{
				Size: 5000,
				Data: buf,
			}
			enc.Encode(send)
			// time.Sleep(time.Second)
			if err != nil {
				log.Fatal(err)
			}
		}
		log.Println("Bytes:", nBytes, "Chunks:", nChunks)

		conn.Close()

	}
	return nil

}