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authorShannon Zhao <shannon.zhao@linaro.org>2015-05-21 17:44:48 +0800
committerStefan Hajnoczi <stefanha@redhat.com>2015-05-27 10:34:07 +0100
commit2bc22a58e16f0650e56dccfac9495e5aef58e2ef (patch)
tree24f38de78463888de57d61aa76bac3639e7fc298 /net/net.c
parenta308817743be5cc051d3379477f54027deb0befb (diff)
net/net: Record usage status of mac address
Currently QEMU dynamically generates mac address for the NIC which doesn't specify the mac address. But when we hotplug a NIC without specifying mac address, the mac address will increase for the same NIC along with hotplug and hot-unplug, and at last it will overflow. And if we codeplug one NIC with mac address e.g. "52:54:00:12:34:56", then hotplug one NIC without specifying mac address and the mac address of the hotplugged NIC is duplicate of "52:54:00:12:34:56". This patch add a mac_table to record the usage status and free the mac address when the NIC is unrealized. Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'net/net.c')
-rw-r--r--net/net.c59
1 files changed, 55 insertions, 4 deletions
diff --git a/net/net.c b/net/net.c
index 0fe5b8bbd5..db6be12a1e 100644
--- a/net/net.c
+++ b/net/net.c
@@ -167,19 +167,68 @@ void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6])
macaddr[3], macaddr[4], macaddr[5]);
}
+static int mac_table[256] = {0};
+
+static void qemu_macaddr_set_used(MACAddr *macaddr)
+{
+ int index;
+
+ for (index = 0x56; index < 0xFF; index++) {
+ if (macaddr->a[5] == index) {
+ mac_table[index]++;
+ }
+ }
+}
+
+static void qemu_macaddr_set_free(MACAddr *macaddr)
+{
+ int index;
+ static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
+
+ if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
+ return;
+ }
+ for (index = 0x56; index < 0xFF; index++) {
+ if (macaddr->a[5] == index) {
+ mac_table[index]--;
+ }
+ }
+}
+
+static int qemu_macaddr_get_free(void)
+{
+ int index;
+
+ for (index = 0x56; index < 0xFF; index++) {
+ if (mac_table[index] == 0) {
+ return index;
+ }
+ }
+
+ return -1;
+}
+
void qemu_macaddr_default_if_unset(MACAddr *macaddr)
{
- static int index = 0;
static const MACAddr zero = { .a = { 0,0,0,0,0,0 } };
+ static const MACAddr base = { .a = { 0x52, 0x54, 0x00, 0x12, 0x34, 0 } };
+
+ if (memcmp(macaddr, &zero, sizeof(zero)) != 0) {
+ if (memcmp(macaddr->a, &base.a, (sizeof(base.a) - 1)) != 0) {
+ return;
+ } else {
+ qemu_macaddr_set_used(macaddr);
+ return;
+ }
+ }
- if (memcmp(macaddr, &zero, sizeof(zero)) != 0)
- return;
macaddr->a[0] = 0x52;
macaddr->a[1] = 0x54;
macaddr->a[2] = 0x00;
macaddr->a[3] = 0x12;
macaddr->a[4] = 0x34;
- macaddr->a[5] = 0x56 + index++;
+ macaddr->a[5] = qemu_macaddr_get_free();
+ qemu_macaddr_set_used(macaddr);
}
/**
@@ -374,6 +423,8 @@ void qemu_del_nic(NICState *nic)
{
int i, queues = MAX(nic->conf->peers.queues, 1);
+ qemu_macaddr_set_free(&nic->conf->macaddr);
+
/* If this is a peer NIC and peer has already been deleted, free it now. */
if (nic->peer_deleted) {
for (i = 0; i < queues; i++) {