[xfer] Make consistent assumptions that xfer metadata can never be NULL

The documentation in xfer.h and xfer.c does not say that the metadata
parameter is optional in calls such as xfer_deliver_iob_meta() and the
deliver_iob() method.  However, some code in net/ is prepared to
accept a NULL pointer, and xfer_deliver_as_iob() passes a NULL pointer
directly to the deliver_iob() method.

Fix this mess of conflicting assumptions by making everything assume
that the metadata parameter is mandatory, and fixing
xfer_deliver_as_iob() to pass in a dummy metadata structure (as is
already done in xfer_deliver_iob()).

diff --git a/src/core/xfer.c b/src/core/xfer.c
index 14c77d6..9ed19da 100644 (file)
--- a/src/core/xfer.c
+++ b/src/core/xfer.c
@@ -27,6 +27,14 @@
  *
  */
 
+/**
+ * Dummy transfer metadata
+ *
+ * This gets passed to xfer_interface::deliver_iob() and equivalents
+ * when no metadata is available.
+ */
+static struct xfer_metadata dummy_metadata;
+
 /**
  * Close data transfer interface
  *
@@ -159,7 +167,6 @@ int xfer_deliver_iob_meta ( struct xfer_interface *xfer,
  */
 int xfer_deliver_iob ( struct xfer_interface *xfer,
                       struct io_buffer *iobuf ) {
-       static struct xfer_metadata dummy_metadata;
        return xfer_deliver_iob_meta ( xfer, iobuf, &dummy_metadata );
 }
 
@@ -366,7 +373,7 @@ int xfer_deliver_as_iob ( struct xfer_interface *xfer,
                return -ENOMEM;
 
        memcpy ( iob_put ( iobuf, len ), data, len );
-       return xfer->op->deliver_iob ( xfer, iobuf, NULL );
+       return xfer->op->deliver_iob ( xfer, iobuf, &dummy_metadata );
 }
 
 /**

diff --git a/src/net/tcp.c b/src/net/tcp.c
index 094317b..6bcd193 100644 (file)
--- a/src/net/tcp.c
+++ b/src/net/tcp.c
@@ -1033,7 +1033,7 @@ static size_t tcp_xfer_window ( struct xfer_interface *xfer ) {
  *
  * @v xfer             Data transfer interface
  * @v iobuf            Datagram I/O buffer
- * @v meta             Data transfer metadata, or NULL
+ * @v meta             Data transfer metadata
  * @ret rc             Return status code
  */
 static int tcp_xfer_deliver_iob ( struct xfer_interface *xfer,

diff --git a/src/net/tcp/ftp.c b/src/net/tcp/ftp.c
index 82dc19c..445e32b 100644 (file)
--- a/src/net/tcp/ftp.c
+++ b/src/net/tcp/ftp.c
@@ -380,7 +380,7 @@ static void ftp_data_closed ( struct xfer_interface *data, int rc ) {
  *
  * @v xfer             FTP data channel interface
  * @v iobuf            I/O buffer
- * @v meta             Data transfer metadata, or NULL
+ * @v meta             Data transfer metadata
  * @ret rc             Return status code
  */
 static int ftp_data_deliver_iob ( struct xfer_interface *data,

diff --git a/src/net/tcp/http.c b/src/net/tcp/http.c
index 5748730..0191750 100644 (file)
--- a/src/net/tcp/http.c
+++ b/src/net/tcp/http.c
@@ -321,7 +321,7 @@ static int http_rx_data ( struct http_request *http,
  *
  * @v socket           Transport layer interface
  * @v iobuf            I/O buffer
- * @v meta             Data transfer metadata, or NULL
+ * @v meta             Data transfer metadata
  * @ret rc             Return status code
  */
 static int http_socket_deliver_iob ( struct xfer_interface *socket,

diff --git a/src/net/udp.c b/src/net/udp.c
index 57edb9c..c3a1eba 100644 (file)
--- a/src/net/udp.c
+++ b/src/net/udp.c
@@ -390,7 +390,7 @@ static struct io_buffer * udp_alloc_iob ( struct xfer_interface *xfer,
  *
  * @v xfer             Data transfer interface
  * @v iobuf            Datagram I/O buffer
- * @v meta             Data transfer metadata, or NULL
+ * @v meta             Data transfer metadata
  * @ret rc             Return status code
  */
 static int udp_xfer_deliver_iob ( struct xfer_interface *xfer,
@@ -398,19 +398,10 @@ static int udp_xfer_deliver_iob ( struct xfer_interface *xfer,
                                  struct xfer_metadata *meta ) {
        struct udp_connection *udp =
                container_of ( xfer, struct udp_connection, xfer );
-       struct sockaddr_tcpip *src = NULL;
-       struct sockaddr_tcpip *dest = NULL;
-       struct net_device *netdev = NULL;
-
-       /* Apply xfer metadata */
-       if ( meta ) {
-               src = ( struct sockaddr_tcpip * ) meta->src;
-               dest = ( struct sockaddr_tcpip * ) meta->dest;
-               netdev = meta->netdev;
-       }
 
        /* Transmit data, if possible */
-       udp_tx ( udp, iobuf, src, dest, netdev );
+       udp_tx ( udp, iobuf, ( ( struct sockaddr_tcpip * ) meta->src ),
+                ( ( struct sockaddr_tcpip * ) meta->dest ), meta->netdev );
 
        return 0;
 }

diff --git a/src/net/udp/dhcp.c b/src/net/udp/dhcp.c
index d149214..776635c 100644 (file)
--- a/src/net/udp/dhcp.c
+++ b/src/net/udp/dhcp.c
@@ -1052,12 +1052,6 @@ static int dhcp_deliver_iob ( struct xfer_interface *xfer,
        int rc = 0;
 
        /* Sanity checks */
-       if ( ! meta ) {
-               DBGC ( dhcp, "DHCP %p received packet without metadata\n",
-                      dhcp );
-               rc = -EINVAL;
-               goto err_no_meta;
-       }
        if ( ! meta->src ) {
                DBGC ( dhcp, "DHCP %p received packet without source port\n",
                       dhcp );
@@ -1106,7 +1100,6 @@ static int dhcp_deliver_iob ( struct xfer_interface *xfer,
        dhcppkt_put ( dhcppkt );
  err_alloc_dhcppkt:
  err_no_src:
- err_no_meta:
        free_iob ( iobuf );
        return rc;
 }

diff --git a/src/net/udp/tftp.c b/src/net/udp/tftp.c
index ec6b1b4..19525f7 100644 (file)
--- a/src/net/udp/tftp.c
+++ b/src/net/udp/tftp.c
@@ -839,7 +839,7 @@ static int tftp_rx_error ( struct tftp_request *tftp, void *buf, size_t len ) {
  *
  * @v tftp             TFTP connection
  * @v iobuf            I/O buffer
- * @v meta             Transfer metadata, or NULL
+ * @v meta             Transfer metadata
  * @ret rc             Return status code
  */
 static int tftp_rx ( struct tftp_request *tftp,
@@ -856,11 +856,6 @@ static int tftp_rx ( struct tftp_request *tftp,
                       "%zd\n", tftp, len );
                goto done;
        }
-       if ( ! meta ) {
-               DBGC ( tftp, "TFTP %p received packet without metadata\n",
-                      tftp );
-               goto done;
-       }
        if ( ! meta->src ) {
                DBGC ( tftp, "TFTP %p received packet without source port\n",
                       tftp );
@@ -907,7 +902,7 @@ static int tftp_rx ( struct tftp_request *tftp,
  *
  * @v socket           Transport layer interface
  * @v iobuf            I/O buffer
- * @v meta             Transfer metadata, or NULL
+ * @v meta             Transfer metadata
  * @ret rc             Return status code
  */
 static int tftp_socket_deliver_iob ( struct xfer_interface *socket,
@@ -951,7 +946,7 @@ static struct xfer_interface_operations tftp_socket_operations = {
  *
  * @v mc_socket                Multicast transport layer interface
  * @v iobuf            I/O buffer
- * @v meta             Transfer metadata, or NULL
+ * @v meta             Transfer metadata
  * @ret rc             Return status code
  */
 static int tftp_mc_socket_deliver_iob ( struct xfer_interface *mc_socket,