[PATCH v2 12/22] tasst: Add ifup and network address helpers to SimNetHost

[David Gibson <david@gibson.dropbear.id.au>]

Add a helper to bring network interfaces up on an snh, and to retrieve
configured IP addresses.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 test/tasst/nstool.py | 11 +++++++++--
 test/tasst/snh.py    | 28 +++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/test/tasst/nstool.py b/test/tasst/nstool.py
index 0b23fbfb..d852d81e 100644
--- a/test/tasst/nstool.py
+++ b/test/tasst/nstool.py
@@ -113,8 +113,11 @@ def test_sockdir_cleanup(s):
         assert not os.path.exists(os.path.dirname(path))
 
 
+@contextlib.contextmanager
 def userns_snh():
-    return unshare_snh('usernetns', '-Ucn')
+    with unshare_snh('usernetns', '-Ucn') as ns:
+        ns.ifup('lo')
+        yield ns
 
 
 @exeter.test
@@ -131,11 +134,15 @@ def test_userns():
 def nested_snh():
     with unshare_snh('userns', '-Uc') as userns:
         with unshare_snh('netns', '-n', parent=userns, capable=True) as netns:
+            netns.ifup('lo')
             yield netns
 
 
+@contextlib.contextmanager
 def pidns_snh():
-    return unshare_snh('pidns', '-Upfn')
+    with unshare_snh('pidns', '-Upfn') as ns:
+        ns.ifup('lo')
+        yield ns
 
 
 @exeter.test
diff --git a/test/tasst/snh.py b/test/tasst/snh.py
index 598ea979..fd8f6f13 100644
--- a/test/tasst/snh.py
+++ b/test/tasst/snh.py
@@ -13,6 +13,7 @@ tasst/snh.py - Simulated network hosts for testing
 
 
 import contextlib
+import ipaddress
 import json
 import subprocess
 import sys
@@ -110,6 +111,25 @@ class SimNetHost(contextlib.AbstractContextManager):
         info = json.loads(self.output('ip', '-j', 'link', 'show'))
         return [i['ifname'] for i in info]
 
+    def ifup(self, ifname):
+        self.fg('ip', 'link', 'set', f'{ifname}', 'up', capable=True)
+
+    def addrinfos(self, ifname, **criteria):
+        info = json.loads(self.output('ip', '-j', 'addr', 'show', f'{ifname}'))
+        assert len(info) == 1  # We specified a specific interface
+
+        ais = list(ai for ai in info[0]['addr_info'])
+        for key, value in criteria.items():
+            ais = [ai for ai in ais if key in ai and ai[key] == value]
+
+        return ais
+
+    def addrs(self, ifname, **criteria):
+        # Return just the parsed, non-tentative addresses
+        return [ipaddress.ip_interface(f'{ai["local"]}/{ai["prefixlen"]}')
+                for ai in self.addrinfos(ifname, **criteria)
+                if 'tentative' not in ai]
+
     # Internal tests
     def test_true(self):
         with self as snh:
@@ -166,10 +186,16 @@ class SimNetHost(contextlib.AbstractContextManager):
         with self as snh:
             assert 'lo' in snh.ifs()
 
+    def test_lo_addrs(self):
+        expected = set(ipaddress.ip_interface(a)
+                       for a in ['127.0.0.1/8', '::1/128'])
+        with self as snh:
+            assert set(snh.addrs('lo')) == expected
+
     SELFTESTS = [test_true, test_false, test_echo, test_timeout,
                  test_bg_true, test_bg_false, test_bg_echo, test_bg_timeout,
                  test_bg_context_timeout,
-                 test_has_lo]
+                 test_has_lo, test_lo_addrs]
 
     @classmethod
     def selftest(cls, setup):
-- 
@@ -13,6 +13,7 @@ tasst/snh.py - Simulated network hosts for testing
 
 
 import contextlib
+import ipaddress
 import json
 import subprocess
 import sys
@@ -110,6 +111,25 @@ class SimNetHost(contextlib.AbstractContextManager):
         info = json.loads(self.output('ip', '-j', 'link', 'show'))
         return [i['ifname'] for i in info]
 
+    def ifup(self, ifname):
+        self.fg('ip', 'link', 'set', f'{ifname}', 'up', capable=True)
+
+    def addrinfos(self, ifname, **criteria):
+        info = json.loads(self.output('ip', '-j', 'addr', 'show', f'{ifname}'))
+        assert len(info) == 1  # We specified a specific interface
+
+        ais = list(ai for ai in info[0]['addr_info'])
+        for key, value in criteria.items():
+            ais = [ai for ai in ais if key in ai and ai[key] == value]
+
+        return ais
+
+    def addrs(self, ifname, **criteria):
+        # Return just the parsed, non-tentative addresses
+        return [ipaddress.ip_interface(f'{ai["local"]}/{ai["prefixlen"]}')
+                for ai in self.addrinfos(ifname, **criteria)
+                if 'tentative' not in ai]
+
     # Internal tests
     def test_true(self):
         with self as snh:
@@ -166,10 +186,16 @@ class SimNetHost(contextlib.AbstractContextManager):
         with self as snh:
             assert 'lo' in snh.ifs()
 
+    def test_lo_addrs(self):
+        expected = set(ipaddress.ip_interface(a)
+                       for a in ['127.0.0.1/8', '::1/128'])
+        with self as snh:
+            assert set(snh.addrs('lo')) == expected
+
     SELFTESTS = [test_true, test_false, test_echo, test_timeout,
                  test_bg_true, test_bg_false, test_bg_echo, test_bg_timeout,
                  test_bg_context_timeout,
-                 test_has_lo]
+                 test_has_lo, test_lo_addrs]
 
     @classmethod
     def selftest(cls, setup):
-- 
2.45.2