[Qemu-devel] [RFC PATCH 01/14] KVM-test: Add a new macaddress pool algorithm

[Amos Kong]

Old method uses the mac address in the configuration files which could
lead serious problem when multiple tests running in different hosts.

This patch adds a new macaddress pool algorithm, it generates the mac prefix
based on mac address of the host which could eliminate the duplicated mac
addresses between machines.

When user have set the mac_prefix in the configuration file, we should use it
in stead of the dynamic generated mac prefix.

Other change:
. Fix randomly generating mac address so that it correspond to IEEE802.
. Update clone function to decide clone mac address or not.
. Update get_macaddr function.
. Add set_mac_address function.

New auto mac address pool algorithm:
If address_index is defined, VM will get mac from config file then record mac
in to address_pool. If address_index is not defined, VM will call
get_mac_from_pool to auto create mac then recored mac to address_pool in
following format:
{'macpool': {'AE:9D:94:6A:9b:f9': ['20100310-165222-Wt7l:0']}}

  AE:9D:94:6A:9b:f9    : mac address
  20100310-165222-Wt7l : instance attribute of VM
  0                    : index of NIC


Signed-off-by: Jason Wang <address@hidden>
Signed-off-by: Feng Yang <address@hidden>
Signed-off-by: Amos Kong <address@hidden>
---
 0 files changed, 0 insertions(+), 0 deletions(-)

diff --git a/client/tests/kvm/kvm_utils.py b/client/tests/kvm/kvm_utils.py
index fb2d1c2..7c0946e 100644
--- a/client/tests/kvm/kvm_utils.py
+++ b/client/tests/kvm/kvm_utils.py
@@ -5,6 +5,7 @@ KVM test utility functions.
 """
 
 import time, string, random, socket, os, signal, re, logging, commands, cPickle
+import fcntl, shelve
 from autotest_lib.client.bin import utils
 from autotest_lib.client.common_lib import error, logging_config
 import kvm_subprocess
@@ -82,6 +83,104 @@ def get_sub_dict_names(dict, keyword):
 
 # Functions related to MAC/IP addresses
 
+def get_mac_from_pool(root_dir, vm, nic_index, prefix='00:11:22:33:'):
+    """
+    random generated mac address.
+
+    1) First try to generate macaddress based on the mac address prefix.
+    2) And then try to use total random generated mac address.
+
+    @param root_dir: Root dir for kvm
+    @param vm: Here we use instance of vm
+    @param nic_index: The index of nic.
+    @param prefix: Prefix of mac address.
+    @Return: Return mac address.
+    """
+
+    lock_filename = os.path.join(root_dir, "mac_lock")
+    lock_file = open(lock_filename, 'w')
+    fcntl.lockf(lock_file.fileno() ,fcntl.LOCK_EX)
+    mac_filename = os.path.join(root_dir, "address_pool")
+    mac_shelve = shelve.open(mac_filename, writeback=False)
+
+    mac_pool = mac_shelve.get("macpool")
+
+    if not mac_pool:
+        mac_pool = {}
+    found = False
+
+    val = "%s:%s" % (vm, nic_index)
+    for key in mac_pool.keys():
+        if val in mac_pool[key]:
+            mac_pool[key].append(val)
+            found = True
+            mac = key
+
+    while not found:
+        postfix = "%02x:%02x" % (random.randint(0x00,0xfe),
+                                random.randint(0x00,0xfe))
+        mac = prefix + postfix
+        mac_list = mac.split(":")
+        # Clear multicast bit
+        mac_list[0] = int(mac_list[0],16) & 0xfe
+        # Set local assignment bit (IEEE802)
+        mac_list[0] = mac_list[0] | 0x02
+        mac_list[0] = "%02x" % mac_list[0]
+        mac = ":".join(mac_list)
+        if mac not in mac_pool.keys() or 0 == len(mac_pool[mac]):
+            mac_pool[mac] = ["%s:%s" % (vm,nic_index)]
+            found = True
+    mac_shelve["macpool"] = mac_pool
+    logging.debug("generating mac addr %s " % mac)
+
+    mac_shelve.close()
+    fcntl.lockf(lock_file.fileno(), fcntl.LOCK_UN)
+    lock_file.close()
+    return mac
+
+
+def put_mac_to_pool(root_dir, mac, vm):
+    """
+    Put the macaddress back to address pool
+
+    @param root_dir: Root dir for kvm
+    @param vm: Here we use instance attribute of vm
+    @param mac: mac address will be put.
+    @Return: mac address.
+    """
+
+    lock_filename = os.path.join(root_dir, "mac_lock")
+    lock_file = open(lock_filename, 'w')
+    fcntl.lockf(lock_file.fileno() ,fcntl.LOCK_EX)
+    mac_filename = os.path.join(root_dir, "address_pool")
+    mac_shelve = shelve.open(mac_filename, writeback=False)
+
+    mac_pool = mac_shelve.get("macpool")
+
+    if not mac_pool or (not mac in mac_pool):
+        logging.debug("Try to free a macaddress does no in pool")
+        logging.debug("macaddress is %s" % mac)
+        logging.debug("pool is %s" % mac_pool)
+    else:
+        if len(mac_pool[mac]) <= 1:
+            mac_pool.pop(mac)
+        else:
+            for value in mac_pool[mac]:
+                if vm in value:
+                    mac_pool[mac].remove(value)
+                    break
+            if len(mac_pool[mac]) == 0:
+                mac_pool.pop(mac)
+
+    mac_shelve["macpool"] = mac_pool
+    logging.debug("freeing mac addr %s " % mac)
+
+    mac_shelve.close()
+    fcntl.lockf(lock_file.fileno(), fcntl.LOCK_UN)
+    lock_file.close()
+    return mac
+
+
 def mac_str_to_int(addr):
     """
     Convert MAC address string to integer.
diff --git a/client/tests/kvm/kvm_vm.py b/client/tests/kvm/kvm_vm.py
index 6cd0688..a9ba6e7 100755
--- a/client/tests/kvm/kvm_vm.py
+++ b/client/tests/kvm/kvm_vm.py
@@ -5,7 +5,7 @@ Utility classes and functions to handle Virtual Machine 
creation using qemu.
 @copyright: 2008-2009 Red Hat Inc.
 """
 
-import time, socket, os, logging, fcntl, re, commands, glob
+import time, socket, os, logging, fcntl, re, commands, shelve, glob
 import kvm_utils, kvm_subprocess, kvm_monitor, rss_file_transfer
 from autotest_lib.client.common_lib import error
 from autotest_lib.client.bin import utils
@@ -117,6 +117,7 @@ class VM:
         self.params = params
         self.root_dir = root_dir
         self.address_cache = address_cache
+        self.mac_prefix = params.get('mac_prefix')
         self.netdev_id = []
 
         # Find a unique identifier for this VM
@@ -126,8 +127,15 @@ class VM:
             if not glob.glob("/tmp/*%s" % self.instance):
                 break
 
+        if self.mac_prefix is None:
+            s, o = commands.getstatusoutput("ifconfig eth0")
+            if s == 0:
+                mac = re.findall("HWaddr (\S*)", o)[0]
+                self.mac_prefix = '00' + mac[8:] + ':'
+
 
-    def clone(self, name=None, params=None, root_dir=None, address_cache=None):
+    def clone(self, name=None, params=None, root_dir=None,
+                    address_cache=None, mac_clone=True):
         """
         Return a clone of the VM object with optionally modified parameters.
         The clone is initially not alive and needs to be started using 
create().
@@ -138,6 +146,7 @@ class VM:
         @param params: Optional new VM creation parameters
         @param root_dir: Optional new base directory for relative filenames
         @param address_cache: A dict that maps MAC addresses to IP addresses
+        @param mac_clone: Clone mac address or not.
         """
         if name is None:
             name = self.name
@@ -147,9 +156,19 @@ class VM:
             root_dir = self.root_dir
         if address_cache is None:
             address_cache = self.address_cache
-        return VM(name, params, root_dir, address_cache)
+        vm = VM(name, params, root_dir, address_cache)
+        if mac_clone:
+            # Clone mac address by coping 'self.instance' to the new vm.
+            vm.instance = self.instance
+        return vm
 
 
+    def free_mac_address(self):
+        nic_num = len(kvm_utils.get_sub_dict_names(self.params, "nics"))
+        for nic in range(nic_num):
+            mac = self.get_macaddr(nic_index=nic)
+            kvm_utils.put_mac_to_pool(self.root_dir, mac, vm=self.instance)
+
     def make_qemu_command(self, name=None, params=None, root_dir=None):
         """
         Generate a qemu command line. All parameters are optional. If a
@@ -383,6 +402,13 @@ class VM:
             mac = None
             if "address_index" in nic_params:
                 mac = kvm_utils.get_mac_ip_pair_from_dict(nic_params)[0]
+                self.set_mac_address(mac=mac, nic_index=vlan)
+            else:
+                mac = kvm_utils.get_mac_from_pool(self.root_dir,
+                                                  vm=self.instance,
+                                                  nic_index=vlan,
+                                                  prefix=self.mac_prefix)
+
             qemu_cmd += add_nic(help, vlan, nic_params.get("nic_model"), mac,
                                 self.netdev_id[vlan])
             # Handle the '-net tap' or '-net user' part
@@ -396,7 +422,7 @@ class VM:
             if tftp:
                 tftp = kvm_utils.get_path(root_dir, tftp)
             qemu_cmd += add_net(help, vlan, nic_params.get("nic_mode", "user"),
-                                nic_params.get("nic_ifname"),
+                                self.get_ifname(vlan),
                                 script, downscript, tftp,
                                 nic_params.get("bootp"), redirs,
                                 self.netdev_id[vlan])
@@ -720,7 +746,7 @@ class VM:
             lockfile.close()
 
 
-    def destroy(self, gracefully=True):
+    def destroy(self, gracefully=True, free_macaddr=True):
         """
         Destroy the VM.
 
@@ -731,6 +757,7 @@ class VM:
         @param gracefully: Whether an attempt will be made to end the VM
                 using a shell command before trying to end the qemu process
                 with a 'quit' or a kill signal.
+        @param free_macaddr: Whether free macaddresses when destory a vm.
         """
         try:
             # Is it already dead?
@@ -751,11 +778,18 @@ class VM:
                         logging.debug("Shutdown command sent; waiting for VM "
                                       "to go down...")
                         if kvm_utils.wait_for(self.is_dead, 60, 1, 1):
-                            logging.debug("VM is down")
+                            logging.debug("VM is down, free mac address.")
+                            # free mac address
+                            if free_macaddr:
+                                self.free_mac_address()
                             return
                     finally:
                         session.close()
 
+            # free mac address
+            if free_macaddr:
+                self.free_mac_address()
+
             if self.monitor:
                 # Try to destroy with a monitor command
                 logging.debug("Trying to kill VM with monitor command...")
@@ -881,10 +915,14 @@ class VM:
         nic_name = nics[index]
         nic_params = kvm_utils.get_sub_dict(self.params, nic_name)
         if nic_params.get("nic_mode") == "tap":
-            mac, ip = kvm_utils.get_mac_ip_pair_from_dict(nic_params)
+            mac = self.get_macaddr(index)
             if not mac:
                 logging.debug("MAC address unavailable")
                 return None
+            else:
+                mac = mac.lower()
+            ip = None
+
             if not ip or nic_params.get("always_use_tcpdump") == "yes":
                 # Get the IP address from the cache
                 ip = self.address_cache.get(mac)
@@ -897,6 +935,7 @@ class VM:
                              for nic in nics]
                 macs = [kvm_utils.get_mac_ip_pair_from_dict(dict)[0]
                         for dict in nic_dicts]
+                macs.append(mac)
                 if not kvm_utils.verify_ip_address_ownership(ip, macs):
                     logging.debug("Could not verify MAC-IP address mapping: "
                                   "%s ---> %s" % (mac, ip))
@@ -925,6 +964,71 @@ class VM:
                              "redirected" % port)
             return self.redirs.get(port)
 
+    def get_ifname(self, nic_index=0):
+        """
+        Return the ifname of tap device for the guest nic.
+
+        @param nic_index: Index of the NIC
+        """
+
+        nics = kvm_utils.get_sub_dict_names(self.params, "nics")
+        nic_name = nics[nic_index]
+        nic_params = kvm_utils.get_sub_dict(self.params, nic_name)
+        if nic_params.get("nic_ifname"):
+            return nic_params.get("nic_ifname")
+        else:
+            return "%s_%s_%s" % (nic_params.get("nic_model"),
+                                 nic_index, self.vnc_port)
+
+    def get_macaddr(self, nic_index=0):
+        """
+        Return the macaddr of guest nic.
+
+        @param nic_index: Index of the NIC
+        """
+        mac_filename = os.path.join(self.root_dir, "address_pool")
+        mac_shelve = shelve.open(mac_filename, writeback=False)
+        mac_pool = mac_shelve.get("macpool")
+        val = "%s:%s" % (self.instance, nic_index)
+        for key in mac_pool.keys():
+            if val in mac_pool[key]:
+                return key
+        return None
+
+    def set_mac_address(self, mac, nic_index=0, shareable=False):
+        """
+        Set mac address for guest. Note: It just update address pool.
+
+        @param mac: address will set to guest
+        @param nic_index: Index of the NIC
+        @param shareable: Where VM can share mac with other VM or not.
+        """
+        lock_filename = os.path.join(self.root_dir, "mac_lock")
+        lock_file = open(lock_filename, 'w')
+        fcntl.lockf(lock_file.fileno() ,fcntl.LOCK_EX)
+        mac_filename = os.path.join(self.root_dir, "address_pool")
+        mac_shelve = shelve.open(mac_filename, writeback=False)
+        mac_pool = mac_shelve.get("macpool")
+        if not mac_pool:
+            mac_pool = {}
+        value = "%s:%s" % (self.instance, nic_index)
+        if mac not in mac_pool.keys():
+            for key in mac_pool.keys():
+                if value in mac_pool[key]:
+                    mac_pool[key].remove(value)
+                if len(mac_pool[key]) == 0:
+                    mac_pool.pop(key)
+            mac_pool[mac] = [value]
+        else:
+            if shareable:
+                mac_pool[mac].append(value)
+            else:
+                logging.error("Mac address already be used!")
+                return False
+        mac_shelve["macpool"] = mac_pool
+        mac_shelve.close()
+        fcntl.lockf(lock_file.fileno(), fcntl.LOCK_UN)
+        lock_file.close()
 
     def get_pid(self):
         """
diff --git a/client/tests/kvm/tests_base.cfg.sample 
b/client/tests/kvm/tests_base.cfg.sample
index fd9e72f..6710c00 100644
--- a/client/tests/kvm/tests_base.cfg.sample
+++ b/client/tests/kvm/tests_base.cfg.sample
@@ -51,7 +51,7 @@ guest_port_remote_shell = 22
 nic_mode = user
 #nic_mode = tap
 nic_script = scripts/qemu-ifup
-address_index = 0
+#address_index = 0
 run_tcpdump = yes
 
 # Misc