From d6e5342f8993b338236bfea1e119c42ee2379b97 Mon Sep 17 00:00:00 2001
From: Matt Borgerson <contact@mborgerson.com>
Date: Tue, 17 Oct 2023 23:34:39 -0700
Subject: [PATCH] nvnet: Add unicast and multicast filtering

---
 hw/xbox/nvnet.c      | 62 ++++++++++++++++++++++++++++++++++++++++++++
 hw/xbox/trace-events |  7 +++++
 2 files changed, 69 insertions(+)

diff --git a/hw/xbox/nvnet.c b/hw/xbox/nvnet.c
index 121369a8be..2440b2cd93 100644
--- a/hw/xbox/nvnet.c
+++ b/hw/xbox/nvnet.c
@@ -25,6 +25,7 @@
 #include "hw/pci/pci.h"
 #include "hw/qdev-properties.h"
 #include "net/net.h"
+#include "qemu/bswap.h"
 #include "qemu/iov.h"
 #include "migration/vmstate.h"
 #include "nvnet_regs.h"
@@ -32,6 +33,8 @@
 #define IOPORT_SIZE 0x8
 #define MMIO_SIZE   0x400
 
+static const uint8_t bcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+
 // #define DEBUG
 #ifdef DEBUG
 #   define NVNET_DPRINTF(format, ...) printf(format, ## __VA_ARGS__)
@@ -432,6 +435,58 @@ static bool nvnet_is_packet_oversized(size_t size)
     return size > RX_ALLOC_BUFSIZE;
 }
 
+static bool receive_filter(NvNetState *s, const uint8_t *buf, int size)
+{
+    if (size < 6) {
+        return false;
+    }
+
+    uint32_t rctl = nvnet_get_reg(s, NvRegPacketFilterFlags, 4);
+    int isbcast = !memcmp(buf, bcast, sizeof bcast);
+
+    /* Broadcast */
+    if (isbcast) {
+        /* FIXME: bcast filtering */
+        trace_nvnet_rx_filter_bcast_match();
+        return true;
+    }
+
+    if (!(rctl & NVREG_PFF_MYADDR)) {
+        /* FIXME: Confirm PFF_MYADDR filters mcast */
+        return true;
+    }
+
+    /* Multicast */
+    uint32_t addr[2];
+    addr[0] = cpu_to_le32(nvnet_get_reg(s, NvRegMulticastAddrA, 4));
+    addr[1] = cpu_to_le32(nvnet_get_reg(s, NvRegMulticastAddrB, 4));
+    if (memcmp(addr, bcast, sizeof bcast)) {
+        uint32_t dest_addr[2];
+        memcpy(dest_addr, buf, 6);
+        dest_addr[0] &= cpu_to_le32(nvnet_get_reg(s, NvRegMulticastMaskA, 4));
+        dest_addr[1] &= cpu_to_le32(nvnet_get_reg(s, NvRegMulticastMaskB, 4));
+
+        if (!memcmp(dest_addr, addr, 6)) {
+            trace_nvnet_rx_filter_mcast_match(MAC_ARG(dest_addr));
+            return true;
+        } else {
+            trace_nvnet_rx_filter_mcast_mismatch(MAC_ARG(dest_addr));
+        }
+    }
+
+    /* Unicast */
+    addr[0] = cpu_to_le32(nvnet_get_reg(s, NvRegMacAddrA, 4));
+    addr[1] = cpu_to_le32(nvnet_get_reg(s, NvRegMacAddrB, 4));
+    if (!memcmp(buf, addr, 6)) {
+        trace_nvnet_rx_filter_ucast_match(MAC_ARG(buf));
+        return true;
+    } else {
+        trace_nvnet_rx_filter_ucast_mismatch(MAC_ARG(buf));
+    }
+
+    return false;
+}
+
 static ssize_t nvnet_receive_iov(NetClientState *nc,
                                  const struct iovec *iov, int iovcnt)
 {
@@ -443,10 +498,17 @@ static ssize_t nvnet_receive_iov(NetClientState *nc,
     if (nvnet_is_packet_oversized(size)) {
         /* Drop */
         NVNET_DPRINTF("%s packet too large!\n", __func__);
+        trace_nvnet_rx_oversized(size);
         return size;
     }
 
     iov_to_buf(iov, iovcnt, 0, s->rx_dma_buf, size);
+
+    if (!receive_filter(s, s->rx_dma_buf, size)) {
+        trace_nvnet_rx_filter_dropped();
+        return size;
+    }
+
 #ifdef DEBUG
     nvnet_hex_dump(s, s->rx_dma_buf, size);
 #endif
diff --git a/hw/xbox/trace-events b/hw/xbox/trace-events
index 91e39b3ce2..fbda278fe7 100644
--- a/hw/xbox/trace-events
+++ b/hw/xbox/trace-events
@@ -7,3 +7,10 @@ nvnet_reg_read(uint32_t addr, const char *name, unsigned int size, uint64_t val)
 nvnet_reg_write(uint32_t addr, const char *name, unsigned int size, uint64_t val) "addr 0x%"PRIx32" %s size %d val 0x%"PRIx64
 nvnet_io_read(uint32_t addr, unsigned int size, uint64_t val) "addr 0x%"PRIx32" size %d val 0x%"PRIx64
 nvnet_io_write(uint32_t addr, unsigned int size, uint64_t val) "addr 0x%"PRIx32" size %d val 0x%"PRIx64
+nvnet_rx_filter_bcast_match(void) "broadcast match"
+nvnet_rx_filter_mcast_match(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) "multicast match: %02x:%02x:%02x:%02x:%02x:%02x"
+nvnet_rx_filter_mcast_mismatch(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) "multicast mismatch: %02x:%02x:%02x:%02x:%02x:%02x"
+nvnet_rx_filter_ucast_match(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) "unicast match: %02x:%02x:%02x:%02x:%02x:%02x"
+nvnet_rx_filter_ucast_mismatch(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3, uint8_t b4, uint8_t b5) "unicast mismatch: %02x:%02x:%02x:%02x:%02x:%02x"
+nvnet_rx_oversized(size_t size) "Received packet dropped because it was oversized (%zu bytes)"
+nvnet_rx_filter_dropped(void) "Received packet dropped by RX filter"