Reserve space for lower-layer headers when allocating packet buffer.

Use pkb_available() rather than pkb_len() (which will always return 0
on a freshly allocated buffer).

udp_send() should assume that the buffer has already been allocated.

diff --git a/src/net/udp.c b/src/net/udp.c
index 584a0cb9c26eaea863b94ad0ad5d33997289880a..94200b2b993687b822d97881ff5c390ddde66920 100644 (file)
--- a/src/net/udp.c
+++ b/src/net/udp.c
@@ -87,24 +87,6 @@ void udp_init ( struct udp_connection *conn, struct udp_operations *udp_op ) {
        }
 }
 
-/**
- * Allocate space to the UDP buffer
- *
- * @v conn      UDP connection
- * @v len       Length to allocate
- * @ret rc      Status
- *
- * Allocate "len" amount of space in the transmit buffer
- */
-int udp_buf_alloc ( struct udp_connection *conn, size_t len ) {
-       if ( conn->tx_pkb != NULL ) {
-               free_pkb ( conn->tx_pkb );
-               conn->tx_pkb = NULL;
-       }
-       conn->tx_pkb = alloc_pkb ( len < UDP_MIN_TXPKB ? UDP_MIN_TXPKB : len );
-       return !conn ? -ENOMEM : 0;
-}
-
 /**
  * User request to send data via a UDP connection
  *
@@ -120,11 +102,12 @@ int udp_senddata ( struct udp_connection *conn ) {
                                                        UDP_MAX_TXPKB );
                return -ENOMEM;
        }
-       conn->udp_op->senddata ( conn, conn->tx_pkb, pkb_len ( conn->tx_pkb ) );
+       pkb_reserve ( conn->tx_pkb, UDP_MAX_HLEN );
+       conn->udp_op->senddata ( conn, conn->tx_pkb, 
+                                pkb_available ( conn->tx_pkb ) );
        return 0;
 }
                
-
 /**
  * Transmit data via a UDP connection
  *
@@ -140,20 +123,9 @@ int udp_send ( struct udp_connection *conn, const void *data, size_t len ) {
                struct udp_header *udphdr;              /* UDP header */
        struct sockaddr *sock = &conn->sin;     /* Destination sockaddr */
        uint16_t *dest;
-       int rc;
 
-       /* Copy data into packet buffer, if necessary */
-       if ( data != conn->tx_pkb->data ) {
-               /* Allocate space for data and lower layer headers */
-               if ( ( rc = udp_buf_alloc ( conn, len + UDP_MAX_HLEN ) ) != 0 ) {
-                       DBG ( "Error allocating buffer" );
-                       return rc;
-               }
-
-               /* Reserve space for the headers and copy contents */
-               pkb_reserve ( conn->tx_pkb, UDP_MAX_HLEN );
-               memmove ( pkb_put ( conn->tx_pkb, len ), data, len );
-       }
+       /* Copy payload */
+       memmove ( pkb_put ( conn->tx_pkb, len ), data, len );
 
        /*
         * Add the UDP header