C++ VNC_DEBUG函数代码示例

static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len)
{
    int auth = read_u32(data, 0);

    if (auth != vs->vd->subauth) {
        VNC_DEBUG("Rejecting auth %d\n", auth);
        vnc_write_u8(vs, 0); /* Reject auth */
        vnc_flush(vs);
        vnc_client_error(vs);
    } else {
        VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth);
        vnc_write_u8(vs, 1); /* Accept auth */
        vnc_flush(vs);

        if (vnc_tls_client_setup(vs, NEED_X509_AUTH(vs)) < 0) {
            VNC_DEBUG("Failed to setup TLS\n");
            return 0;
        }

        VNC_DEBUG("Start TLS VeNCrypt handshake process\n");
        if (vnc_start_vencrypt_handshake(vs) < 0) {
            VNC_DEBUG("Failed to start TLS handshake\n");
            return 0;
        }
    }
    return 0;
}

static int vnc_auth_sasl_check_access(VncState *vs)
{
    const void *val;
    int err;
    int allow;

    err = sasl_getprop(vs->sasl.conn, SASL_USERNAME, &val);
    if (err != SASL_OK) {
        VNC_DEBUG("cannot query SASL username on connection %d (%s), denying access\n",
                  err, sasl_errstring(err, NULL, NULL));
        return -1;
    }
    if (val == NULL) {
        VNC_DEBUG("no client username was found, denying access\n");
        return -1;
    }
    VNC_DEBUG("SASL client username %s\n", (const char *)val);

    vs->sasl.username = g_strdup((const char*)val);

    if (vs->vd->sasl.acl == NULL) {
        VNC_DEBUG("no ACL activated, allowing access\n");
        return 0;
    }

    allow = qemu_acl_party_is_allowed(vs->vd->sasl.acl, vs->sasl.username);

    VNC_DEBUG("SASL client %s %s by ACL\n", vs->sasl.username,
              allow ? "allowed" : "denied");
    return allow ? 0 : -1;
}

static int vnc_start_vencrypt_handshake(struct VncState *vs) {
    int ret;

    if ((ret = gnutls_handshake(vs->tls.session)) < 0) {
       if (!gnutls_error_is_fatal(ret)) {
           VNC_DEBUG("Handshake interrupted (blocking)\n");
           if (!gnutls_record_get_direction(vs->tls.session))
               qemu_set_fd_handler(vs->csock, vnc_tls_handshake_io, NULL, vs);
           else
               qemu_set_fd_handler(vs->csock, NULL, vnc_tls_handshake_io, vs);
           return 0;
       }
       VNC_DEBUG("Handshake failed %s\n", gnutls_strerror(ret));
       vnc_client_error(vs);
       return -1;
    }

    if (vs->vd->tls.x509verify) {
        if (vnc_tls_validate_certificate(vs) < 0) {
            VNC_DEBUG("Client verification failed\n");
            vnc_client_error(vs);
            return -1;
        } else {
            VNC_DEBUG("Client verification passed\n");
        }
    }

    VNC_DEBUG("Handshake done, switching to TLS data mode\n");
    vs->tls.wiremode = VNC_WIREMODE_TLS;
    qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, vnc_client_write, vs);

    start_auth_vencrypt_subauth(vs);

    return 0;
}

static void start_auth_vencrypt_subauth(VncState *vs)
{
    switch (vs->subauth) {
    case VNC_AUTH_VENCRYPT_TLSNONE:
    case VNC_AUTH_VENCRYPT_X509NONE:
       VNC_DEBUG("Accept TLS auth none\n");
       vnc_write_u32(vs, 0); /* Accept auth completion */
       start_client_init(vs);
       break;

    case VNC_AUTH_VENCRYPT_TLSVNC:
    case VNC_AUTH_VENCRYPT_X509VNC:
       VNC_DEBUG("Start TLS auth VNC\n");
       start_auth_vnc(vs);
       break;

#ifdef CONFIG_VNC_SASL
    case VNC_AUTH_VENCRYPT_TLSSASL:
    case VNC_AUTH_VENCRYPT_X509SASL:
      VNC_DEBUG("Start TLS auth SASL\n");
      start_auth_sasl(vs);
      break;
#endif /* CONFIG_VNC_SASL */

    default: /* Should not be possible, but just in case */
       VNC_DEBUG("Reject subauth %d server bug\n", vs->auth);
       vnc_write_u8(vs, 1);
       if (vs->minor >= 8) {
           static const char err[] = "Unsupported authentication type";
           vnc_write_u32(vs, sizeof(err));
           vnc_write(vs, err, sizeof(err));
       }
       vnc_client_error(vs);
    }
}

static int vncws_start_tls_handshake(struct VncState *vs)
{
    int ret = gnutls_handshake(vs->ws_tls.session);

    if (ret < 0) {
        if (!gnutls_error_is_fatal(ret)) {
            VNC_DEBUG("Handshake interrupted (blocking)\n");
            if (!gnutls_record_get_direction(vs->ws_tls.session)) {
                qemu_set_fd_handler(vs->csock, vncws_tls_handshake_io,
                                    NULL, vs);
            } else {
                qemu_set_fd_handler(vs->csock, NULL, vncws_tls_handshake_io,
                                    vs);
            }
            return 0;
        }
        VNC_DEBUG("Handshake failed %s\n", gnutls_strerror(ret));
        vnc_client_error(vs);
        return -1;
    }

    VNC_DEBUG("Handshake done, switching to TLS data mode\n");
    vs->ws_tls.wiremode = VNC_WIREMODE_TLS;
    qemu_set_fd_handler2(vs->csock, NULL, vncws_handshake_read, NULL, vs);

    return 0;
}

void vncws_tls_handshake_io(void *opaque)
{
    VncState *vs = (VncState *)opaque;
    Error *err = NULL;

    vs->tls = qcrypto_tls_session_new(vs->vd->tlscreds,
                                      NULL,
                                      vs->vd->tlsaclname,
                                      QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
                                      &err);
    if (!vs->tls) {
        VNC_DEBUG("Failed to setup TLS %s\n",
                  error_get_pretty(err));
        error_free(err);
        vnc_client_error(vs);
        return;
    }

    qcrypto_tls_session_set_callbacks(vs->tls,
                                      vnc_tls_push,
                                      vnc_tls_pull,
                                      vs);

    VNC_DEBUG("Start TLS WS handshake process\n");
    vncws_start_tls_handshake(vs);
}

void vncws_tls_handshake_io(void *opaque)
{
    struct VncState *vs = (struct VncState *)opaque;

    if (!vs->tls.session) {
        VNC_DEBUG("TLS Websocket setup\n");
        if (vnc_tls_client_setup(vs, vs->vd->tls.x509cert != NULL) < 0) {
            return;
        }
    }
    VNC_DEBUG("Handshake IO continue\n");
    vncws_start_tls_handshake(vs);
}

static void vncws_tls_handshake_done(Object *source,
                                     Error *err,
                                     gpointer user_data)
{
    VncState *vs = user_data;

    if (err) {
        VNC_DEBUG("Handshake failed %s\n", error_get_pretty(err));
        vnc_client_error(vs);
    } else {
        VNC_DEBUG("TLS handshake complete, starting websocket handshake\n");
        vs->ioc_tag = qio_channel_add_watch(
            QIO_CHANNEL(vs->ioc), G_IO_IN, vncws_handshake_io, vs, NULL);
    }
}

static void vncws_send_handshake_response(VncState *vs, const char* key)
{
    char combined_key[WS_CLIENT_KEY_LEN + WS_GUID_LEN + 1];
    unsigned char hash[SHA1_DIGEST_LEN];
    size_t hash_size = sizeof(hash);
    char *accept = NULL, *response = NULL;
    gnutls_datum_t in;
    int ret;

    g_strlcpy(combined_key, key, WS_CLIENT_KEY_LEN + 1);
    g_strlcat(combined_key, WS_GUID, WS_CLIENT_KEY_LEN + WS_GUID_LEN + 1);

    /* hash and encode it */
    in.data = (void *)combined_key;
    in.size = WS_CLIENT_KEY_LEN + WS_GUID_LEN;
    ret = gnutls_fingerprint(GNUTLS_DIG_SHA1, &in, hash, &hash_size);
    if (ret == GNUTLS_E_SUCCESS && hash_size <= SHA1_DIGEST_LEN) {
        accept = g_base64_encode(hash, hash_size);
    }
    if (accept == NULL) {
        VNC_DEBUG("Hashing Websocket combined key failed\n");
        vnc_client_error(vs);
        return;
    }

    response = g_strdup_printf(WS_HANDSHAKE, accept);
    vnc_client_write_buf(vs, (const uint8_t *)response, strlen(response));

    g_free(accept);
    g_free(response);

    vs->encode_ws = 1;
    vnc_init_state(vs);
}

static void vnc_tls_handshake_io(void *opaque)
{
    VncState *vs = (VncState *)opaque;

    VNC_DEBUG("Handshake IO continue\n");
    vnc_start_vencrypt_handshake(vs);
}

static void vncws_tls_handshake_io(void *opaque)
{
    struct VncState *vs = (struct VncState *)opaque;

    VNC_DEBUG("Handshake IO continue\n");
    vncws_start_tls_handshake(vs);
}

long vnc_client_read_ws(VncState *vs)
{
    int ret, err;
    uint8_t *payload;
    size_t payload_size, frame_size;
    VNC_DEBUG("Read websocket %p size %zd offset %zd\n", vs->ws_input.buffer,
            vs->ws_input.capacity, vs->ws_input.offset);
    buffer_reserve(&vs->ws_input, 4096);
    ret = vnc_client_read_buf(vs, buffer_end(&vs->ws_input), 4096);
    if (!ret) {
        return 0;
    }
    vs->ws_input.offset += ret;

    /* make sure that nothing is left in the ws_input buffer */
    do {
        err = vncws_decode_frame(&vs->ws_input, &payload,
                              &payload_size, &frame_size);
        if (err <= 0) {
            return err;
        }

        buffer_reserve(&vs->input, payload_size);
        buffer_append(&vs->input, payload, payload_size);

        buffer_advance(&vs->ws_input, frame_size);
    } while (vs->ws_input.offset > 0);

    return ret;
}

void vncws_handshake_read(void *opaque)
{
    VncState *vs = opaque;
    uint8_t *handshake_end;
    long ret;
    /* Typical HTTP headers from novnc are 512 bytes, so limiting
     * total header size to 4096 is easily enough. */
    size_t want = 4096 - vs->ws_input.offset;
    buffer_reserve(&vs->ws_input, want);
    ret = vnc_client_read_buf(vs, buffer_end(&vs->ws_input), want);

    if (!ret) {
        if (vs->csock == -1) {
            vnc_disconnect_finish(vs);
        }
        return;
    }
    vs->ws_input.offset += ret;

    handshake_end = (uint8_t *)g_strstr_len((char *)vs->ws_input.buffer,
            vs->ws_input.offset, WS_HANDSHAKE_END);
    if (handshake_end) {
        qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, NULL, vs);
        vncws_process_handshake(vs, vs->ws_input.buffer, vs->ws_input.offset);
        buffer_advance(&vs->ws_input, handshake_end - vs->ws_input.buffer +
                strlen(WS_HANDSHAKE_END));
    } else if (vs->ws_input.offset >= 4096) {
        VNC_DEBUG("End of headers not found in first 4096 bytes\n");
        vnc_client_error(vs);
    }
}

static int vnc_set_x509_credential(VncDisplay *vd,
                                   const char *certdir,
                                   const char *filename,
                                   char **cred,
                                   int ignoreMissing)
{
    struct stat sb;

    if (*cred) {
        g_free(*cred);
        *cred = NULL;
    }

    *cred = g_malloc(strlen(certdir) + strlen(filename) + 2);

    strcpy(*cred, certdir);
    strcat(*cred, "/");
    strcat(*cred, filename);

    VNC_DEBUG("Check %s\n", *cred);
    if (stat(*cred, &sb) < 0) {
        g_free(*cred);
        *cred = NULL;
        if (ignoreMissing && errno == ENOENT)
            return 0;
        return -1;
    }

    return 0;
}

static void vncws_send_handshake_response(VncState *vs, const char* key)
{
    char combined_key[WS_CLIENT_KEY_LEN + WS_GUID_LEN + 1];
    char *accept = NULL, *response = NULL;
    Error *err = NULL;

    g_strlcpy(combined_key, key, WS_CLIENT_KEY_LEN + 1);
    g_strlcat(combined_key, WS_GUID, WS_CLIENT_KEY_LEN + WS_GUID_LEN + 1);

    /* hash and encode it */
    if (qcrypto_hash_base64(QCRYPTO_HASH_ALG_SHA1,
                            combined_key,
                            WS_CLIENT_KEY_LEN + WS_GUID_LEN,
                            &accept,
                            &err) < 0) {
        VNC_DEBUG("Hashing Websocket combined key failed %s\n",
                  error_get_pretty(err));
        error_free(err);
        vnc_client_error(vs);
        return;
    }

    response = g_strdup_printf(WS_HANDSHAKE, accept);
    vnc_client_write_buf(vs, (const uint8_t *)response, strlen(response));

    g_free(accept);
    g_free(response);

    vs->encode_ws = 1;
    vnc_init_state(vs);
}