krb5/os/read_msg.c

/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 * lib/krb5/os/read_msg.c
 *
 * Copyright 1991 by the Massachusetts Institute of Technology.
 * All Rights Reserved.
 *
 * Export of this software from the United States of America may
 *   require a specific license from the United States Government.
 *   It is the responsibility of any person or organization contemplating
 *   export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 *
 * Write a message to the network
 */

#include "k5-int.h"
#include <errno.h>

krb5_error_code
krb5_read_message(krb5_context context, krb5_pointer fdp, krb5_data *inbuf)
{
    krb5_int32      len;
    int             len2, ilen;
    char            *buf = NULL;
    int             fd = *( (int *) fdp);

    inbuf->data = NULL;
    inbuf->length = 0;

    if ((len2 = krb5_net_read(context, fd, (char *)&len, 4)) != 4)
        return((len2 < 0) ? errno : ECONNABORTED);
    len = ntohl(len);

    if ((len & VALID_UINT_BITS) != (krb5_ui_4) len)  /* Overflow size_t??? */
        return ENOMEM;

    inbuf->length = ilen = (int) len;
    if (ilen) {
        /*
         * We may want to include a sanity check here someday....
         */
        if (!(buf = malloc(inbuf->length))) {
            return(ENOMEM);
        }
        if ((len2 = krb5_net_read(context, fd, buf, ilen)) != ilen) {
            free(buf);
            return((len2 < 0) ? errno : ECONNABORTED);
        }
    }
    inbuf->data = buf;
    return(0);
}