toys/pb/tcp_server.cpp

#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <netinet/in.h>
#include <resolv.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <pthread.h>
#include "message.pb.h"
#include <iostream>
#include <google/protobuf/io/coded_stream.h>
#include <google/protobuf/io/zero_copy_stream_impl.h>

using namespace std;
using namespace google::protobuf::io;

void *SocketHandler(void *);

int main(int argv, char **argc)
{

    int host_port = 1101;

    struct sockaddr_in my_addr;

    int hsock;
    int *p_int;
    int err;

    socklen_t addr_size = 0;
    int *csock;
    sockaddr_in sadr;
    pthread_t thread_id = 0;

    hsock = socket(AF_INET, SOCK_STREAM, 0);
    if (hsock == -1)
    {
        printf("Error initializing socket %d\n", errno);
        goto FINISH;
    }

    p_int = (int *)malloc(sizeof(int));
    *p_int = 1;

    if ((setsockopt(hsock, SOL_SOCKET, SO_REUSEADDR, (char *)p_int, sizeof(int)) == -1) ||
        (setsockopt(hsock, SOL_SOCKET, SO_KEEPALIVE, (char *)p_int, sizeof(int)) == -1))
    {
        printf("Error setting options %d\n", errno);
        free(p_int);
        goto FINISH;
    }
    free(p_int);

    my_addr.sin_family = AF_INET;
    my_addr.sin_port = htons(host_port);

    memset(&(my_addr.sin_zero), 0, 8);
    my_addr.sin_addr.s_addr = INADDR_ANY;

    if (bind(hsock, (sockaddr *)&my_addr, sizeof(my_addr)) == -1)
    {
        fprintf(stderr, "Error binding to socket, make sure nothing else is listening on this port %d\n", errno);
        goto FINISH;
    }
    if (listen(hsock, 10) == -1)
    {
        fprintf(stderr, "Error listening %d\n", errno);
        goto FINISH;
    }

    //Now lets do the server stuff

    addr_size = sizeof(sockaddr_in);

    while (true)
    {
        printf("waiting for a connection\n");
        csock = (int *)malloc(sizeof(int));
        if ((*csock = accept(hsock, (sockaddr *)&sadr, &addr_size)) != -1)
        {
            printf("---------------------\nReceived connection from %s\n", inet_ntoa(sadr.sin_addr));
            pthread_create(&thread_id, 0, &SocketHandler, (void *)csock);
            pthread_detach(thread_id);
        }
        else
        {
            fprintf(stderr, "Error accepting %d\n", errno);
        }
    }

FINISH:; //oops
}

google::protobuf::uint32 readHdr(char *buf)
{
    google::protobuf::uint32 size;
    google::protobuf::io::ArrayInputStream ais(buf, 4);
    CodedInputStream coded_input(&ais);
    coded_input.ReadVarint32(&size); //Decode the HDR and get the size
    cout << "size of payload is " << size << endl;
    return size;
}

void readBody(int csock, google::protobuf::uint32 siz)
{
    int bytecount;
    log_packet payload;
    char buffer[siz + 4]; //size of the payload and hdr
    //Read the entire buffer including the hdr
    if ((bytecount = recv(csock, (void *)buffer, 4 + siz, MSG_WAITALL)) == -1)
    {
        fprintf(stderr, "Error receiving data %d\n", errno);
    }
    cout << "Second read byte count is " << bytecount << endl;
    //Assign ArrayInputStream with enough memory
    google::protobuf::io::ArrayInputStream ais(buffer, siz + 4);
    CodedInputStream coded_input(&ais);
    //Read an unsigned integer with Varint encoding, truncating to 32 bits.
    coded_input.ReadVarint32(&siz);
    //After the message's length is read, PushLimit() is used to prevent the CodedInputStream
    //from reading beyond that length.Limits are used when parsing length-delimited
    //embedded messages
    google::protobuf::io::CodedInputStream::Limit msgLimit = coded_input.PushLimit(siz);
    //De-Serialize
    payload.ParseFromCodedStream(&coded_input);
    //Once the embedded message has been parsed, PopLimit() is called to undo the limit
    coded_input.PopLimit(msgLimit);
    //Print the message
    cout << "Message is " << payload.DebugString();
}

void *SocketHandler(void *lp)
{
    int *csock = (int *)lp;

    char buffer[4];
    int bytecount = 0;
    string output, pl;
    log_packet logp;

    memset(buffer, '\0', 4);

    while (1)
    {
        //Peek into the socket and get the packet size
        if ((bytecount = recv(*csock,
                              buffer,
                              4, MSG_PEEK)) == -1)
        {
            fprintf(stderr, "Error receiving data %d\n", errno);
        }
        else if (bytecount == 0)
            break;
        cout << "First read byte count is " << bytecount << endl;
        readBody(*csock, readHdr(buffer));
    }

FINISH:
    free(csock);
    return 0;
}