[Linux] Test failure due to broken handling of IPv6 [FAIL: psutil.tests.test_linux.TestSystemNetIfAddrs.test_ips]

[torsava]

Summary

• OS: Linux
• Architecture: 64bit (x86_64)
• Psutil version: 5.8.0
• Python version: Python 3.9.1
• Type: tests

Description

Test psutil.tests.test_linux.TestSystemNetIfAddrs.test_ips fails when an interface has multiple IPv6 addresses.

Test failure:

...
======================================================================
FAIL: psutil.tests.test_linux.TestSystemNetIfAddrs.test_ips
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/psutil-release-5.8.0/psutil/tests/test_linux.py", line 947, in test_ips
    self.assertEqual(address, get_ipv6_address(name))
AssertionError: '2620:52:0:1330:d7b2:99a4:96ab:a55' != 'fe80::f1d4:c17e:7251:901b'
- 2620:52:0:1330:d7b2:99a4:96ab:a55
+ fe80::f1d4:c17e:7251:901b
----------------------------------------------------------------------
Ran 543 tests in 3.524s
FAILED (failures=1, skipped=182)

Test case:

   def test_ips(self):
        for name, addrs in psutil.net_if_addrs().items():
            for addr in addrs:
                if addr.family == psutil.AF_LINK:
                    self.assertEqual(addr.address, get_mac_address(name))
                elif addr.family == socket.AF_INET:
                    self.assertEqual(addr.address, get_ipv4_address(name))
                    self.assertEqual(addr.netmask, get_ipv4_netmask(name))
                    if addr.broadcast is not None:
                        self.assertEqual(addr.broadcast,
                                         get_ipv4_broadcast(name))
                    else:
                        self.assertEqual(get_ipv4_broadcast(name), '0.0.0.0')
                elif addr.family == socket.AF_INET6:
                    # IPv6 addresses can have a percent symbol at the end.
                    # E.g. these 2 are equivalent:
                    # "fe80::1ff:fe23:4567:890a"
                    # "fe80::1ff:fe23:4567:890a%eth0"
                    # That is the "zone id" portion, which usually is the name
                    # of the network interface.
                    address = addr.address.split('%')[0]
                    self.assertEqual(address, get_ipv6_address(name))

Current code of the get_ipv6_address function:

def get_ipv6_address(ifname):
    with open("/proc/net/if_inet6", 'rt') as f:
        for line in f.readlines():
            fields = line.split()
            if fields[-1] == ifname:
                break
        else:
            raise ValueError("could not find interface %r" % ifname)
    unformatted = fields[0]
    groups = []
    for i in range(0, len(unformatted), 4):
        groups.append(unformatted[i:i + 4])
    formatted = ":".join(groups)
    packed = socket.inet_pton(socket.AF_INET6, formatted)
    return socket.inet_ntop(socket.AF_INET6, packed)

The problem is caused because get_ipv6_address returns only the first IPv6 address for the given interface, and then the address is compared in self.assertEqual(address, get_ipv6_address(name)).

Instead, get_ipv6_address should return all IPv6 addresses for the given interface, and then the test should check whether address is among them.

[giampaolo]

Fixed in #2086.