CODEWITHSUNDEEP
clinuxsockets
user4238474
user4238474

Reputation:

How to destructively close a socket when my write() times out?

Not sure how well I worded the title. I've written a linux domain socket server and client. The client sets a timeout value on the write. If the client can't send all of its data I don't want the server to accept the data that it has sent. Is there way the client can indicate that it didn't send all of the data? Maybe somehow cause the server's read() to fail? The sockets are setup as stream sockets.

So basically I want to know what to do in this case:

ssize_t bytes_written = write(fd, buffer, length);
if (bytes_written == -1)
    {
    result = -1;
    goto done;
    }

// I think the only case where we can have write return                     
// a successful code but not all bytes written is when the                  
// timeout value has elapsed and some number of bytes have                  
// been written.                                                            

if (bytes_written != length)
    {
    result = -1;
    errno = ETIMEDOUT;
    }
.
.
.

done:
    if (result == -1)
        result = errno;
    if (fd != -1)
        {
        shutdown(fd, SHUT_RDWR);
        close(fd);
        }
    return result;
}

I realize an obvious solution is for the client to send a byte count first and then send the bytes. I was wondering whether there was another way. Also, each message could be a different size.

Upvotes: 0

Views: 45

Answers (1)

stan
stan

Reputation: 139

You can packet your data with a length in the head. If the data doesn't match the length, the server can drop the data.

Upvotes: 1

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