CODEWITHSUNDEEP
c++socketserrnoberkeley-sockets
Darkgaze
Darkgaze

Reputation: 2573

recvfrom non-blocking returning BAD ADDRESS error in c++

I'm getting a "BAD ADDRESS" error when trying to listen and not when sending. Sending works perfectly with sendto().

Here's the function that creates the socket to listen. IP and Port are local (this is intented to execute in the same local network, in fact, in the same pc using a linux virtual machine and a windows machine).

Using NULL in getaddrinfo(NULL, port, &hints, &addrInfoResults); seems like the way to go: no idea why using the local IP of the sender (192.168.1.50 for example) would not work. But sending works.

    int socketDescriptor;
    sockaddr socketAddress;

    struct addrinfo hints;
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_family = AF_INET; // Allow only IPv4
    hints.ai_socktype = SOCK_DGRAM; // Datagram socket, type of packages used in UDP
    hints.ai_protocol = IPPROTO_UDP; // UDP protocol
    hints.ai_flags = AI_PASSIVE; // USE MY IP


    // resolve dynamically IP adress by getaddrinfo()
    struct addrinfo *addrInfoResults;
    int resVal = getaddrinfo(ip, port, &hints, &addrInfoResults);
    if (resVal != 0) {
        // ERROR
        return false;
    }

    struct addrinfo *addInf;
    for(addInf = addrInfoResults;addInf != NULL; addInf = addInf->ai_next) {
        if (addInf->ai_family == AF_INET) { // IPv4
            struct sockaddr_in *ipv4 = (struct sockaddr_in *)addInf->ai_addr;
            void *addr = &(ipv4->sin_addr);

            // convert the IP to a string
            char ipstr[16]; // IPv4 is 16
            inet_ntop(addInf->ai_family, addr, ipstr, sizeof ipstr);
            break;
        }
    }

    // Create connection with socket
    socketDescriptor = 0;
    if ( (socketDescriptor = socket(addInf->ai_family, addInf->ai_socktype, addInf->ai_protocol)) == -1)
    {
        // ERROR...
        return false;
    }

    // Try to bind to that address
    if (bind(socketDescriptor, addInf->ai_addr, addInf->ai_addrlen) == -1)
    {
        // ERROR
        return false;
    }

    socketAddress = *(addInf->ai_addr);
    freeaddrinfo(addrInfoResults);

    // Set socket non blocking
    fcntl(socketDescriptor, F_SETFL, O_NONBLOCK);

When connecting, no error is received from any call. Socket is created. The call to receive is this one:

    socklen_t addrSize = sizeof(socketAddress);
    int numbytes = recvfrom(socketDescriptor,
                        buffer,
                        sizeof(bufferStruct),
                        0,
                        &socketAddress,
                        &addrSize);

    if (numbytes < 0)
    {

        int errnoBackup = errno;
        if (errnoBackup != EWOULDBLOCK && errnoBackup != EAGAIN)
        {
            _logFile << "ERROR" << std::endl;
            ....

Why am I getting a BAD Address error? I've read all posts related to this and none help. I'm always receiving a -1.

Tests I've done so far:

Upvotes: 0

Views: 501

Answers (1)

Darkgaze
Darkgaze

Reputation: 2573

Just for everybody to know about this. In case you have BAD ADDRESS, as IBM documentation depicts:

When calling recvfrom: It is a problem with the buffer (pointing to NULL), the address (pointing to a wrong place or you are not passing the reference to the actual place and not a pointer), or the size of the address (that you didn't calculate it correctly).

My problem was that I didn't initialize the buffer.

Upvotes: 1

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