From debb66b59cfff00b34c55cd6965b240f783187bb Mon Sep 17 00:00:00 2001
From: Radek Vykydal <rvykydal@redhat.com>
Date: Aug 06 2020 08:07:49 +0000
Subject: network: fix parsing of hostname from ip= if mac is defined in dhcp


Resolves: rhbz#1852560

---

diff --git a/pyanaconda/core/regexes.py b/pyanaconda/core/regexes.py
index 63ab668..ee5cc37 100644
--- a/pyanaconda/core/regexes.py
+++ b/pyanaconda/core/regexes.py
@@ -191,3 +191,6 @@ ZFCP_WWPN_NUMBER = re.compile(r'^(?:0x|)[0-9A-Fa-f]{16}$')
 
 # IPv6 address in dracut IP option (including the square brackets)
 IPV6_ADDRESS_IN_DRACUT_IP_OPTION = re.compile(r'\[[^\]]+\]')
+
+# Octet of MAC address
+MAC_OCTET = re.compile(r'[a-fA-F0-9][a-fA-F0-9]')
diff --git a/pyanaconda/network.py b/pyanaconda/network.py
index f8e9b19..80bdb3e 100644
--- a/pyanaconda/network.py
+++ b/pyanaconda/network.py
@@ -37,7 +37,7 @@ from dasbus.typing import get_native
 from pyanaconda.core.i18n import _
 from pyanaconda.core.kernel import kernel_arguments
 from pyanaconda.core.regexes import HOSTNAME_PATTERN_WITHOUT_ANCHORS, \
-    IPV6_ADDRESS_IN_DRACUT_IP_OPTION
+    IPV6_ADDRESS_IN_DRACUT_IP_OPTION, MAC_OCTET
 from pyanaconda.core.configuration.anaconda import conf
 from pyanaconda.modules.common.constants.services import NETWORK, TIMEZONE, STORAGE
 from pyanaconda.modules.common.constants.objects import FCOE
@@ -209,7 +209,7 @@ def hostname_from_cmdline(kernel_args):
     """
     # legacy hostname= option
     hostname = kernel_args.get('hostname', "")
-    # ip= option
+    # ip= option (man dracut.cmdline)
     ipopts = kernel_args.get('ip')
     # Example (2 options):
     # ens3:dhcp 10.34.102.244::10.34.102.54:255.255.255.0:myhostname:ens9:none
@@ -219,10 +219,13 @@ def hostname_from_cmdline(kernel_args):
                 # Replace ipv6 addresses with empty string, example of ipv6 config:
                 # [fd00:10:100::84:5]::[fd00:10:100::86:49]:80:myhostname:ens9:none
                 ipopt = IPV6_ADDRESS_IN_DRACUT_IP_OPTION.sub('', ipopt)
-            try:
+            elements = ipopt.split(':')
+            # Hostname can be defined only in option having more than 6 elements.
+            # But filter out auto ip= with mac address set by MAC_OCTET matching, eg:
+            # ip=<interface>:dhcp::52:54:00:12:34:56
+            # where the 4th element is not hostname.
+            if len(elements) > 6 and not re.match(MAC_OCTET, elements[6]):
                 hostname = ipopt.split(':')[4]
-            except IndexError:
-                pass
     return hostname
 
 
diff --git a/tests/nosetests/pyanaconda_tests/network_test.py b/tests/nosetests/pyanaconda_tests/network_test.py
index e7ca630..161e883 100644
--- a/tests/nosetests/pyanaconda_tests/network_test.py
+++ b/tests/nosetests/pyanaconda_tests/network_test.py
@@ -233,9 +233,11 @@ class NetworkTests(unittest.TestCase):
         cmdline = {"ip": "10.34.102.244::10.34.102.54:255.255.255.0:myhostname:ens9:none",
                    "hostname": "hostname_bootopt"}
         self.assertEqual(network.hostname_from_cmdline(cmdline), "myhostname")
-        cmdline = {"ip": "ens3:dhcp "}
+        cmdline = {"ip": "ens3:dhcp"}
         self.assertEqual(network.hostname_from_cmdline(cmdline), "")
-        cmdline = {"ip": "ens3:dhcp ",
+        cmdline = {"ip": "ens3:dhcp:1500"}
+        self.assertEqual(network.hostname_from_cmdline(cmdline), "")
+        cmdline = {"ip": "ens3:dhcp",
                    "hostname": "hostname_bootopt"}
         self.assertEqual(network.hostname_from_cmdline(cmdline), "hostname_bootopt")
         # two ip configurations
@@ -248,6 +250,9 @@ class NetworkTests(unittest.TestCase):
         self.assertEqual(network.hostname_from_cmdline(cmdline), "myhostname")
         cmdline = {"ip": "[fd00:10:100::84:5]::[fd00:10:100::86:49]:80::ens50:none"}
         self.assertEqual(network.hostname_from_cmdline(cmdline), "")
-        cmdline = {"ip": "[fd00:10:100::84:5]::[fd00:10:100::86:49]:80::ens50:none"
+        cmdline = {"ip": "[fd00:10:100::84:5]::[fd00:10:100::86:49]:80::ens50:none "
                          "ens3:dhcp 10.34.102.244::10.34.102.54:255.255.255.0:myhostname:ens9:none"}
         self.assertEqual(network.hostname_from_cmdline(cmdline), "myhostname")
+        # automatic ip= whith MAC address set
+        cmdline = {"ip": "ens3:dhcp::52:54:00:12:34:56"}
+        self.assertEqual(network.hostname_from_cmdline(cmdline), "")