au-ts · alexandermbrown · Jul 28, 2024 · Jul 28, 2024 · Jul 1, 2024 · Jul 29, 2024
diff --git a/include/sddf/network/mac802.h b/include/sddf/network/mac802.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024, UNSW (ABN 57 195 873 179)
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <sddf/util/printf.h>
+
+#define PR_MAC802_ADDR  "%x:%x:%x:%x:%x:%x"
+
+/* Expects a *pointer* to a struct ether_addr */
+#define PR_MAC802_ADDR_ARGS(a, dir)     (a)->ether_##dir##_addr_octet[0], \
+                                        (a)->ether_##dir##_addr_octet[1], \
+                                        (a)->ether_##dir##_addr_octet[2], \
+                                        (a)->ether_##dir##_addr_octet[3], \
+                                        (a)->ether_##dir##_addr_octet[4], \
+                                        (a)->ether_##dir##_addr_octet[5]
+
+#define PR_MAC802_DEST_ADDR_ARGS(a) PR_MAC802_ADDR_ARGS(a, dest)
+#define PR_MAC802_SRC_ADDR_ARGS(a) PR_MAC802_ADDR_ARGS(a, src)
+
+#define MAC802_BYTES 6
+
+/* This is a name for the 96 bit ethernet addresses available on many
+   systems.  */
+struct ether_addr {
+    uint8_t ether_dest_addr_octet[MAC802_BYTES];
+    uint8_t ether_src_addr_octet[MAC802_BYTES];
+    uint8_t etype[2]; // Ethertype
+    uint8_t payload[46];
+    uint8_t crc[4];
+} __attribute__ ((__packed__));
+
+
+static inline bool mac802_addr_eq_num(const uint8_t *addr0, const uint8_t *addr1, unsigned int num)
+{
+    for (int i = 0; i < num; i++) {
+        if (addr0[i] != addr1[i]) {
+            return false;
+        }
+    }
+    return true;
+}
+
+static inline bool mac802_addr_eq(const uint8_t *addr0, const uint8_t *addr1)
+{
+    return mac802_addr_eq_num(addr0, addr1, MAC802_BYTES);
+}
+
+static inline bool mac802_addr_is_bcast(const uint8_t *addr)
+{
+    const uint8_t bcast_macaddr[MAC802_BYTES] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+    return mac802_addr_eq(addr, bcast_macaddr);
+}
diff --git a/include/sddf/network/vswitch.h b/include/sddf/network/vswitch.h
@@ -0,0 +1,28 @@
+#pragma once
+#include <microkit.h>
+#include <sddf/network/queue.h>
+
+#define VSWITCH_MAX_PORT_COUNT 64
+
+typedef uint64_t vswitch_port_bitmap_t;
+
+typedef struct vswitch_channel {
+    net_queue_handle_t q;
+    microkit_channel ch;
+    char *data_region;
+} vswitch_channel_t;
+
+/* These ports are analogous to ports on a physical switch.
+ * They represent a medium you can send to and receive from. */
+typedef struct vswitch_port {
+    /* For clients, incoming is TX, outgoing is RX.
+     * For virtualisers, incoming is RX, outgoing is TX. */
+    vswitch_channel_t incoming;
+    vswitch_channel_t outgoing;
+    vswitch_port_bitmap_t allow_list;
+} vswitch_port_t;
+
+static inline bool vswitch_can_send_to(vswitch_port_t *src, int dst)
+{
+    return src->allow_list & (1 << (uint64_t)dst);
+}
diff --git a/network/components/copy.c b/network/components/copy.c
@@ -4,6 +4,7 @@
 #include <sddf/util/string.h>
 #include <sddf/util/util.h>
 #include <sddf/util/printf.h>
+#include <sddf/util/string.h>
 #include <ethernet_config.h>
 
 #define VIRT_RX_CH 0

diff --git a/network/components/virt_rx.c b/network/components/virt_rx.c
@@ -94,7 +94,11 @@ void rx_return(void)
             //
             // [1]: https://developer.arm.com/documentation/ddi0595/2021-06/AArch64-Instructions/DC-IVAC--Data-or-unified-Cache-line-Invalidate-by-VA-to-PoC
             cache_clean_and_invalidate(buffer_vaddr, buffer_vaddr + buffer.len);
-            int client = get_mac_addr_match((struct ethernet_header *) buffer_vaddr);
+            // int client = get_mac_addr_match((struct ethernet_header *) buffer_vaddr);
+
+            // Layer 2 forwarding now happens in the vswitch
+            int client = 0;
+
             if (client == BROADCAST_ID) {
                 int ref_index = buffer.io_or_offset / NET_BUFFER_SIZE;
                 assert(buffer_refs[ref_index] == 0);

diff --git a/network/components/virt_tx.c b/network/components/virt_tx.c
@@ -133,7 +133,7 @@ void init(void)
 
     /* CDTODO: Can we make this system agnostic? */
     state.buffer_region_paddrs[0] = buffer_data_region_cli0_paddr;
-    state.buffer_region_paddrs[1] = buffer_data_region_cli1_paddr;
+    // state.buffer_region_paddrs[1] = buffer_data_region_cli1_paddr;
 
     tx_provide();
 }
diff --git a/network/components/vswitch/vswitch.c b/network/components/vswitch/vswitch.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright 2024, UNSW
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <microkit.h>
+#include <sddf/network/vswitch.h>
+#include <sddf/network/queue.h>
+#include <sddf/network/mac802.h>
+#include <sddf/network/util.h>
+#include <sddf/util/fence.h>
+#include <sddf/util/util.h>
+#include <sddf/util/printf.h>
+#define VSWITCH_IMPL
+#include <vswitch_config.h>
+
+_Static_assert(VSWITCH_PORT_COUNT <= VSWITCH_MAX_PORT_COUNT, "Too many ports");
+#define UNKNOWN_PORT -1
+
+typedef struct mac_addr {
+    uint8_t addr[6];
+} mac_addr_t;
+
+typedef struct channel_map {
+    // Store macs contiguously for better cache performance during lookup.
+    mac_addr_t macs[VSWITCH_LOOKUP_SIZE];
+    uint8_t port[VSWITCH_LOOKUP_SIZE];
+    uint32_t len;
+} channel_map_t;
+
+static struct {
+    vswitch_port_t ports[VSWITCH_PORT_COUNT];
+    channel_map_t map;
+} vswitch;
+
+
+static int channel_map_find(channel_map_t *map, const uint8_t *dest_macaddr)
+{
+    for (int i = 0; i < map->len; i++) {
+        if (mac802_addr_eq(map->macs[i].addr, dest_macaddr)) {
+            return map->port[i];
+        }
+    }
+    return UNKNOWN_PORT;
+}
+
+static bool channel_map_add(channel_map_t *map, const uint8_t *macaddr, int port)
+{
+    if (map->len >= VSWITCH_LOOKUP_SIZE) {
+        sddf_dprintf("VSWITCH: Channel map is full\n");
+        return false;
+    }
+    if (channel_map_find(map, macaddr) != UNKNOWN_PORT) {
+        return false;
+    }
+    if (mac802_addr_is_bcast(macaddr)) {
+        return false;
+    }
+
+    sddf_memcpy(map->macs[map->len].addr, macaddr, 6);
+    map->port[map->len] = port;
+    map->len++;
+    return true;
+}
+
+static void forward_frame(vswitch_channel_t *src, vswitch_channel_t *dest, net_buff_desc_t *src_buf)
+{
+    const char *src_data = src->data_region + src_buf->io_or_offset;
+
+    net_buff_desc_t d_buffer;
+    if (net_dequeue_free(&dest->q, &d_buffer) != 0) {
+        return;
+    }
+    // TODO: make fast memcpy
+    sddf_memcpy(dest->data_region + d_buffer.io_or_offset, src_data, src_buf->len);
+
+    d_buffer.len = src_buf->len;
+    net_enqueue_active(&dest->q, d_buffer);
+
+    if (net_require_signal_active(&dest->q)) {
+        net_cancel_signal_active(&dest->q);
+        microkit_notify(dest->ch);
+    }
+}
+
+static void try_broadcast(int src_port, vswitch_port_t *src, net_buff_desc_t *buffer)
+{
+    for (int i = 0; i < VSWITCH_PORT_COUNT; i++) {
+        if (i != src_port && vswitch_can_send_to(src, i)) {
+            vswitch_channel_t *outgoing = &vswitch.ports[i].outgoing;
+            forward_frame(&src->incoming, outgoing, buffer);
+        }
+    }
+}
+
+static void try_send(vswitch_port_t *src, const uint8_t *dest_macaddr, net_buff_desc_t *buffer)
+{
+    int dest_port = channel_map_find(&vswitch.map, dest_macaddr);
+
+    if (dest_port == UNKNOWN_PORT || !vswitch_can_send_to(src, dest_port)) {
+        return;
+    }
+
+    vswitch_channel_t *outgoing = &vswitch.ports[dest_port].outgoing;
+    forward_frame(&src->incoming, outgoing, buffer);
+}
+
+static void notified_by_port(int port)
+{
+    net_buff_desc_t sddf_buffer;
+
+    vswitch_port_t *src = &vswitch.ports[port];
+    net_queue_handle_t *src_queue = &src->incoming.q;
+
+    bool reprocess = true;
+    while (reprocess) {
+        while (net_dequeue_active(src_queue, &sddf_buffer) != -1) {
+            const char *frame_data = src->incoming.data_region + sddf_buffer.io_or_offset;
+            const struct ether_addr *macaddr = (void *)frame_data;
+
+            // Add forwarding table entry from source MAC to port
+            channel_map_add(&vswitch.map, macaddr->ether_src_addr_octet, port);
+
+            // Forward frame
+            if (mac802_addr_is_bcast(macaddr->ether_dest_addr_octet)) {
+                try_broadcast(port, src, &sddf_buffer);
+            } else {
+                try_send(src, macaddr->ether_dest_addr_octet, &sddf_buffer);
+            }
+
+            sddf_buffer.len = 0;
+            net_enqueue_free(src_queue, sddf_buffer);
+        }
+
+        net_request_signal_active(src_queue);
+        reprocess = false;
+
+        if (!net_queue_empty_active(src_queue)) {
+            net_cancel_signal_active(src_queue);
+            reprocess = true;
+        }
+    }
+}
+
+void notified(microkit_channel ch)
+{
+    // This could be optimised but port count is usually low.
+    for (int port = 0; port < VSWITCH_PORT_COUNT; port++) {
+        if (ch == vswitch.ports[port].incoming.ch) {
+            notified_by_port(port);
+            return;
+        }
+        if (ch == vswitch.ports[port].outgoing.ch) {
+            // TODO: check if anyone is waiting for room in this port?
+            // Might be better to drop packets in this case.
+            return;
+        }
+    }
+}
+
+void init(void)
+{
+    for (int i = 0; i < VSWITCH_PORT_COUNT; i++) {
+        net_vswitch_init_port(i, &vswitch.ports[i]);
+        net_buffers_init(&vswitch.ports[i].outgoing.q, 0);
+    }
+}
diff --git a/network/components/vswitch/vswitch.mk b/network/components/vswitch/vswitch.mk
@@ -0,0 +1,49 @@
+#
+# Copyright 2024, UNSW
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# This Makefile snippet builds the network components
+# (for example, simple RX and TX virtualisers)
+# it should be included into your project Makefile
+#
+# NOTES:
+# Generates vswitch.elf
+# Requires ${SDDF}/util/util.mk to build the utility library for debug output
+
+
+VSWITCH_COMPONENTS_DIR := $(abspath $(dir $(lastword ${MAKEFILE_LIST})))
+VSWITCH_IMAGES := vswitch.elf
+network/components/vswitch/%.o: ${SDDF}/network/components/%.c
+	${CC} ${CFLAGS} -c -o $@ $<
+
+VSWITCH_COMPONENT_OBJ := network/components/vswitch/vswitch.o
+
+CFLAGS_vswitch += ${NUM_VSWITCH_CLIENTS} -I${SDDF}/include/sddf/util
+
+CHECK_VSWITCH_FLAGS_MD5:=.vswitch_cflags-$(shell echo -- ${CFLAGS} ${CFLAGS_vswitch} | shasum | sed 's/ *-//')
+
+${CHECK_VSWITCH_FLAGS_MD5}:
+	-rm -f .vswitch_cflags-*
+	touch $@
+
+
+${VSWITCH_IMAGES}: LIBS := libsddf_util_debug.a ${LIBS}
+
+${VSWITCH_COMPONENT_OBJ}: |network/components/vswitch
+${VSWITCH_COMPONENT_OBJ}: ${CHECK_NETWORK_FLAGS_MD5}
+${VSWITCH_COMPONENT_OBJ}: CFLAGS+=${CFLAGS_vswitch}
+
+%.elf: network/components/vswitch/%.o
+	${LD} ${LDFLAGS} -o $@ $< ${LIBS}
+
+clean::
+	rm -f vswitch.[od]
+
+clobber::
+	rm -f ${IMAGES}
+
+network/components/vswitch:
+	mkdir -p $@
+
+-include ${VSWITCH_COMPONENTS_OBJS:.o=.d}