diff --git a/hw/eepro100.c b/hw/eepro100.c
index e3ba719..02e6f7e 100644
--- a/hw/eepro100.c
+++ b/hw/eepro100.c
@@ -322,33 +322,8 @@ static const uint16_t eepro100_mdi_mask[] = {
     0xffff, 0xffff, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
 };
 
-#define POLYNOMIAL 0x04c11db6
-
 static E100PCIDeviceInfo *eepro100_get_class(EEPRO100State *s);
 
-/* From FreeBSD */
-/* XXX: optimize */
-static unsigned compute_mcast_idx(const uint8_t * ep)
-{
-    uint32_t crc;
-    int carry, i, j;
-    uint8_t b;
-
-    crc = 0xffffffff;
-    for (i = 0; i < 6; i++) {
-        b = *ep++;
-        for (j = 0; j < 8; j++) {
-            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
-            crc <<= 1;
-            b >>= 1;
-            if (carry) {
-                crc = ((crc ^ POLYNOMIAL) | carry);
-            }
-        }
-    }
-    return (crc & BITS(7, 2)) >> 2;
-}
-
 /* Read a 16 bit control/status (CSR) register. */
 static uint16_t e100_read_reg2(EEPRO100State *s, E100RegisterOffset addr)
 {
diff --git a/hw/ne2000.c b/hw/ne2000.c
index 71452e1..d02e60c 100644
--- a/hw/ne2000.c
+++ b/hw/ne2000.c
@@ -150,30 +150,6 @@ static void ne2000_update_irq(NE2000State *s)
     qemu_set_irq(s->irq, (isr != 0));
 }
 
-#define POLYNOMIAL 0x04c11db6
-
-/* From FreeBSD */
-/* XXX: optimize */
-static int compute_mcast_idx(const uint8_t *ep)
-{
-    uint32_t crc;
-    int carry, i, j;
-    uint8_t b;
-
-    crc = 0xffffffff;
-    for (i = 0; i < 6; i++) {
-        b = *ep++;
-        for (j = 0; j < 8; j++) {
-            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
-            crc <<= 1;
-            b >>= 1;
-            if (carry)
-                crc = ((crc ^ POLYNOMIAL) | carry);
-        }
-    }
-    return (crc >> 26);
-}
-
 static int ne2000_buffer_full(NE2000State *s)
 {
     int avail, index, boundary;
diff --git a/hw/opencores_eth.c b/hw/opencores_eth.c
index 9b036cb..06ef712 100644
--- a/hw/opencores_eth.c
+++ b/hw/opencores_eth.c
@@ -351,31 +351,6 @@ static int open_eth_can_receive(VLANClientState *nc)
         (rx_desc(s)->len_flags & RXD_E);
 }
 
-#define POLYNOMIAL 0x04c11db6
-
-/* From FreeBSD */
-/* XXX: optimize */
-static unsigned compute_mcast_idx(const uint8_t *ep)
-{
-    uint32_t crc;
-    int carry, i, j;
-    uint8_t b;
-
-    crc = 0xffffffff;
-    for (i = 0; i < 6; i++) {
-        b = *ep++;
-        for (j = 0; j < 8; j++) {
-            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
-            crc <<= 1;
-            b >>= 1;
-            if (carry) {
-                crc = ((crc ^ POLYNOMIAL) | carry);
-            }
-        }
-    }
-    return crc >> 26;
-}
-
 static ssize_t open_eth_receive(VLANClientState *nc,
         const uint8_t *buf, size_t size)
 {
diff --git a/hw/rtl8139.c b/hw/rtl8139.c
index a946e79..509a53e 100644
--- a/hw/rtl8139.c
+++ b/hw/rtl8139.c
@@ -708,30 +708,6 @@ static void rtl8139_update_irq(RTL8139State *s)
     qemu_set_irq(s->dev.irq[0], (isr != 0));
 }
 
-#define POLYNOMIAL 0x04c11db6
-
-/* From FreeBSD */
-/* XXX: optimize */
-static int compute_mcast_idx(const uint8_t *ep)
-{
-    uint32_t crc;
-    int carry, i, j;
-    uint8_t b;
-
-    crc = 0xffffffff;
-    for (i = 0; i < 6; i++) {
-        b = *ep++;
-        for (j = 0; j < 8; j++) {
-            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
-            crc <<= 1;
-            b >>= 1;
-            if (carry)
-                crc = ((crc ^ POLYNOMIAL) | carry);
-        }
-    }
-    return (crc >> 26);
-}
-
 static int rtl8139_RxWrap(RTL8139State *s)
 {
     /* wrapping enabled; assume 1.5k more buffer space if size < 65536 */
diff --git a/net.c b/net.c
index c34474f..1922d8a 100644
--- a/net.c
+++ b/net.c
@@ -1475,3 +1475,26 @@ int net_client_parse(QemuOptsList *opts_list, const char *optarg)
     default_net = 0;
     return 0;
 }
+
+/* From FreeBSD */
+/* XXX: optimize */
+unsigned compute_mcast_idx(const uint8_t *ep)
+{
+    uint32_t crc;
+    int carry, i, j;
+    uint8_t b;
+
+    crc = 0xffffffff;
+    for (i = 0; i < 6; i++) {
+        b = *ep++;
+        for (j = 0; j < 8; j++) {
+            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
+            crc <<= 1;
+            b >>= 1;
+            if (carry) {
+                crc = ((crc ^ POLYNOMIAL) | carry);
+            }
+        }
+    }
+    return crc >> 26;
+}
diff --git a/net.h b/net.h
index 75a8c15..64993b4 100644
--- a/net.h
+++ b/net.h
@@ -182,6 +182,9 @@ void qdev_set_nic_properties(DeviceState *dev, NICInfo *nd);
 
 int net_handle_fd_param(Monitor *mon, const char *param);
 
+#define POLYNOMIAL 0x04c11db6
+unsigned compute_mcast_idx(const uint8_t *ep);
+
 #define vmstate_offset_macaddr(_state, _field)                       \
     vmstate_offset_array(_state, _field.a, uint8_t,                \
                          sizeof(typeof_field(_state, _field)))
