[eoib] Support non-FullMember gateway devices

Some EoIB implementations utilise an EoIB-to-Ethernet gateway device
that does not perform a FullMember join to the multicast group for the
EoIB broadcast domain.  This has various exciting side-effects, such
as requiring every EoIB node to send every broadcast packet twice.

As an added bonus, the gateway may also break the EoIB MAC address to
GID mapping protocol by sending Ethernet-sourced packets from the
wrong QPN.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/drivers/net/eoib.c b/src/drivers/net/eoib.c
index a5f9e29ee40b298c530c4a1e743ef062afadf752..f58e74b7d496ce1d5e84a850533fe1c81f690fbb 100644 (file)
--- a/src/drivers/net/eoib.c
+++ b/src/drivers/net/eoib.c
@@ -269,6 +269,14 @@ static void eoib_rx_av ( struct eoib_device *eoib, const uint8_t *mac,
                return;
        }
 
+       /* Some dubious EoIB implementations utilise an Ethernet-to-
+        * EoIB gateway that will send packets from the wrong QPN.
+        */
+       if ( eoib_has_gateway ( eoib ) &&
+            ( memcmp ( gid, &eoib->gateway.gid, sizeof ( *gid ) ) == 0 ) ) {
+               qpn = eoib->gateway.qpn;
+       }
+
        /* Do nothing if peer cache entry is complete and correct */
        if ( ( peer->av.lid == av->lid ) && ( peer->av.qpn == qpn ) ) {
                DBGCP ( eoib, "EoIB %s %s RX unchanged\n",
@@ -326,9 +334,14 @@ static int eoib_transmit ( struct net_device *netdev,
        if ( iob_len ( iobuf ) < zlen )
                iob_pad ( iobuf, zlen );
 
-       /* If we have no unicast address then send as a broadcast */
-       if ( ! av )
+       /* If we have no unicast address then send as a broadcast,
+        * with a duplicate sent to the gateway if applicable.
+        */
+       if ( ! av ) {
                av = &eoib->broadcast;
+               if ( eoib_has_gateway ( eoib ) )
+                       eoib->duplicate ( eoib, iobuf );
+       }
 
        /* Post send work queue entry */
        return ib_post_send ( eoib->ibdev, eoib->qp, av, iobuf );
@@ -797,3 +810,86 @@ struct net_protocol eoib_heartbeat_protocol __net_protocol = {
        .rx = eoib_heartbeat_rx,
        .ntoa = eoib_heartbeat_ntoa,
 };
+
+/****************************************************************************
+ *
+ * EoIB gateway
+ *
+ ****************************************************************************
+ *
+ * Some dubious EoIB implementations require all broadcast traffic to
+ * be sent twice: once to the actual broadcast group, and once as a
+ * unicast to the EoIB-to-Ethernet gateway.  This somewhat curious
+ * design arises since the EoIB-to-Ethernet gateway hardware lacks the
+ * ability to attach a queue pair to a multicast GID (or LID), and so
+ * cannot receive traffic sent to the broadcast group.
+ *
+ */
+
+/**
+ * Transmit duplicate packet to the EoIB gateway
+ *
+ * @v eoib             EoIB device
+ * @v original         Original I/O buffer
+ */
+static void eoib_duplicate ( struct eoib_device *eoib,
+                            struct io_buffer *original ) {
+       struct net_device *netdev = eoib->netdev;
+       struct ib_device *ibdev = eoib->ibdev;
+       struct ib_address_vector *av = &eoib->gateway;
+       size_t len = iob_len ( original );
+       struct io_buffer *copy;
+       int rc;
+
+       /* Create copy of I/O buffer */
+       copy = alloc_iob ( len );
+       if ( ! copy ) {
+               rc = -ENOMEM;
+               goto err_alloc;
+       }
+       memcpy ( iob_put ( copy, len ), original->data, len );
+
+       /* Append to network device's transmit queue */
+       list_add_tail ( &copy->list, &original->list );
+
+       /* Resolve path to gateway */
+       if ( ( rc = ib_resolve_path ( ibdev, av ) ) != 0 ) {
+               DBGC ( eoib, "EoIB %s no path to gateway: %s\n",
+                      eoib->name, strerror ( rc ) );
+               goto err_path;
+       }
+
+       /* Force use of GRH even for local destinations */
+       av->gid_present = 1;
+
+       /* Post send work queue entry */
+       if ( ( rc = ib_post_send ( eoib->ibdev, eoib->qp, av, copy ) ) != 0 )
+               goto err_post_send;
+
+       return;
+
+ err_post_send:
+ err_path:
+ err_alloc:
+       netdev_tx_complete_err ( netdev, copy, rc );
+}
+
+/**
+ * Set EoIB gateway
+ *
+ * @v eoib             EoIB device
+ * @v av               Address vector, or NULL to clear gateway
+ */
+void eoib_set_gateway ( struct eoib_device *eoib,
+                       struct ib_address_vector *av ) {
+
+       if ( av ) {
+               DBGC ( eoib, "EoIB %s using gateway " IB_GID_FMT "\n",
+                      eoib->name, IB_GID_ARGS ( &av->gid ) );
+               memcpy ( &eoib->gateway, av, sizeof ( eoib->gateway ) );
+               eoib->duplicate = eoib_duplicate;
+       } else {
+               DBGC ( eoib, "EoIB %s not using gateway\n", eoib->name );
+               eoib->duplicate = NULL;
+       }
+}

diff --git a/src/include/ipxe/eoib.h b/src/include/ipxe/eoib.h
index acae542b6d331af25aab0a01f0759b9f270c292d..93f496c3623291d94176ce34e95eda981f769e48 100644 (file)
--- a/src/include/ipxe/eoib.h
+++ b/src/include/ipxe/eoib.h
@@ -49,10 +49,30 @@ struct eoib_device {
        /** Peer cache */
        struct list_head peers;
 
+       /** Send duplicate packet to gateway (or NULL)
+        *
+        * @v eoib              EoIB device
+        * @v original          Original I/O buffer
+        */
+       void ( * duplicate ) ( struct eoib_device *eoib,
+                              struct io_buffer *original );
+       /** Gateway (if any) */
+       struct ib_address_vector gateway;
        /** Multicast group additional component mask */
        unsigned int mask;
 };
 
+/**
+ * Check if EoIB device uses a gateway
+ *
+ * @v eoib             EoIB device
+ * @v has_gw           EoIB device uses a gateway
+ */
+static inline int eoib_has_gateway ( struct eoib_device *eoib ) {
+
+       return ( eoib->duplicate != NULL );
+}
+
 /**
  * Force creation of multicast group
  *
@@ -77,5 +97,7 @@ extern int eoib_create ( struct ib_device *ibdev, const uint8_t *hw_addr,
 extern struct eoib_device * eoib_find ( struct ib_device *ibdev,
                                        const uint8_t *hw_addr );
 extern void eoib_destroy ( struct eoib_device *eoib );
+extern void eoib_set_gateway ( struct eoib_device *eoib,
+                              struct ib_address_vector *av );
 
 #endif /* _IPXE_EOIB_H */