selftests: net: reuse common code in bpf_offload

net/lib/py/nsim.py already contains the most useful parts
of the netdevsim wrapper classes. Reuse them.
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240409031549.3531084-5-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/bpf_offload.py

@@ -29,6 +29,9 @@ import subprocess
 import time
 import traceback
 
+from lib.py import NetdevSim, NetdevSimDev
+
+
 logfile = None
 log_level = 1
 skip_extack = False
@@ -145,8 +148,10 @@ def tool(name, args, flags, JSON=True, ns="", fail=True, include_stderr=False):
     if JSON:
         params += "%s " % (flags["json"])
 
-    if ns != "":
+    if ns:
         ns = "ip netns exec %s " % (ns)
+    elif ns is None:
+        ns = ""
 
     if include_stderr:
         ret, stdout, stderr = cmd(ns + name + " " + params + args,
@@ -334,72 +339,16 @@ class DebugfsDir:
 
         return dfs
 
-class NetdevSimDev:
+class BpfNetdevSimDev(NetdevSimDev):
     """
     Class for netdevsim bus device and its attributes.
     """
-    @staticmethod
-    def ctrl_write(path, val):
-        fullpath = os.path.join("/sys/bus/netdevsim/", path)
-        try:
-            with open(fullpath, "w") as f:
-                f.write(val)
-        except OSError as e:
-            log("WRITE %s: %r" % (fullpath, val), -e.errno)
-            raise e
-        log("WRITE %s: %r" % (fullpath, val), 0)
-
-    def __init__(self, port_count=1):
-        addr = 0
-        while True:
-            try:
-                self.ctrl_write("new_device", "%u %u" % (addr, port_count))
-            except OSError as e:
-                if e.errno == errno.ENOSPC:
-                    addr += 1
-                    continue
-                raise e
-            break
-        self.addr = addr
-
-        # As probe of netdevsim device might happen from a workqueue,
-        # so wait here until all netdevs appear.
-        self.wait_for_netdevs(port_count)
-
-        ret, out = cmd("udevadm settle", fail=False)
-        if ret:
-            raise Exception("udevadm settle failed")
-        ifnames = self.get_ifnames()
-
+    def __init__(self, port_count=1, ns=None):
+        super().__init__(port_count, ns=ns)
         devs.append(self)
-        self.dfs_dir = "/sys/kernel/debug/netdevsim/netdevsim%u/" % addr
-
-        self.nsims = []
-        for port_index in range(port_count):
-            self.nsims.append(NetdevSim(self, port_index, ifnames[port_index]))
-
-    def get_ifnames(self):
-        ifnames = []
-        listdir = os.listdir("/sys/bus/netdevsim/devices/netdevsim%u/net/" % self.addr)
-        for ifname in listdir:
-            ifnames.append(ifname)
-        ifnames.sort()
-        return ifnames
-
-    def wait_for_netdevs(self, port_count):
-        timeout = 5
-        timeout_start = time.time()
-
-        while True:
-            try:
-                ifnames = self.get_ifnames()
-            except FileNotFoundError as e:
-                ifnames = []
-            if len(ifnames) == port_count:
-                break
-            if time.time() < timeout_start + timeout:
-                continue
-            raise Exception("netdevices did not appear within timeout")
+
+    def _make_port(self, port_index, ifname):
+        return BpfNetdevSim(self, port_index, ifname, self.ns)
 
     def dfs_num_bound_progs(self):
         path = os.path.join(self.dfs_dir, "bpf_bound_progs")
@@ -415,33 +364,20 @@ class NetdevSimDev:
         return progs
 
     def remove(self):
-        self.ctrl_write("del_device", "%u" % (self.addr, ))
+        super().remove()
         devs.remove(self)
 
-    def remove_nsim(self, nsim):
-        self.nsims.remove(nsim)
-        self.ctrl_write("devices/netdevsim%u/del_port" % (self.addr, ),
-                        "%u" % (nsim.port_index, ))
 
-class NetdevSim:
+class BpfNetdevSim(NetdevSim):
     """
     Class for netdevsim netdevice and its attributes.
     """
 
-    def __init__(self, nsimdev, port_index, ifname):
-        # In case udev renamed the netdev to according to new schema,
-        # check if the name matches the port_index.
-        nsimnamere = re.compile("eni\d+np(\d+)")
-        match = nsimnamere.match(ifname)
-        if match and int(match.groups()[0]) != port_index + 1:
-            raise Exception("netdevice name mismatches the expected one")
-
-        self.nsimdev = nsimdev
-        self.port_index = port_index
-        self.ns = ""
+    def __init__(self, nsimdev, port_index, ifname, ns=None):
+        super().__init__(nsimdev, port_index, ifname, ns=ns)
+
         self.dfs_dir = "%s/ports/%u/" % (nsimdev.dfs_dir, port_index)
         self.dfs_refresh()
-        _, [self.dev] = ip("link show dev %s" % ifname)
 
     def __getitem__(self, key):
         return self.dev[key]
@@ -468,7 +404,7 @@ class NetdevSim:
         raise Exception("Time out waiting for program counts to stabilize want %d/%d, have %d bound, %d loaded" % (bound, total, nbound, nprogs))
 
     def set_ns(self, ns):
-        name = "1" if ns == "" else ns
+        name = ns if ns else "1"
         ip("link set dev %s netns %s" % (self.dev["ifname"], name), ns=self.ns)
         self.ns = ns
 
@@ -744,7 +680,7 @@ def test_multi_prog(simdev, sim, obj, modename, modeid):
     start_test("Test multi-attachment XDP - device remove...")
     simdev.remove()
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.set_ethtool_tc_offloads(True)
     return [simdev, sim]
@@ -809,13 +745,13 @@ try:
     bytecode = bpf_bytecode("1,6 0 0 4294967295,")
 
     start_test("Test destruction of generic XDP...")
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.set_xdp(obj, "generic")
     simdev.remove()
     bpftool_prog_list_wait(expected=0)
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.tc_add_ingress()
 
@@ -967,7 +903,7 @@ try:
     simdev.remove()
     bpftool_prog_list_wait(expected=0)
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.set_ethtool_tc_offloads(True)
 
@@ -976,7 +912,7 @@ try:
     simdev.remove()
     bpftool_prog_list_wait(expected=0)
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.set_ethtool_tc_offloads(True)
 
@@ -1080,7 +1016,7 @@ try:
     bpftool_prog_list_wait(expected=0)
 
     start_test("Test attempt to use a program for a wrong device...")
-    simdev2 = NetdevSimDev()
+    simdev2 = BpfNetdevSimDev()
     sim2, = simdev2.nsims
     sim2.set_xdp(obj, "offload")
     pin_file, pinned = pin_prog("/sys/fs/bpf/tmp")
@@ -1169,7 +1105,7 @@ try:
     clean_up()
     bpftool_prog_list_wait(expected=0)
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     map_obj = bpf_obj("sample_map_ret0.bpf.o")
     start_test("Test loading program with maps...")
@@ -1201,7 +1137,7 @@ try:
     clean_up()
     bpftool_prog_list_wait(expected=0)
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
 
     start_test("Test map update (no flags)...")
@@ -1285,14 +1221,14 @@ try:
     bpftool_map_list_wait(expected=0)
     simdev.remove()
 
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.set_xdp(map_obj, "offload", JSON=False) # map fixup msg breaks JSON
     simdev.remove()
     bpftool_map_list_wait(expected=0)
 
     start_test("Test map creation fail path...")
-    simdev = NetdevSimDev()
+    simdev = BpfNetdevSimDev()
     sim, = simdev.nsims
     sim.dfs["bpf_map_accept"] = "N"
     ret, _ = sim.set_xdp(map_obj, "offload", JSON=False, fail=False)
@@ -1302,9 +1238,9 @@ try:
     simdev.remove()
 
     start_test("Test multi-dev ASIC program reuse...")
-    simdevA = NetdevSimDev()
+    simdevA = BpfNetdevSimDev()
     simA, = simdevA.nsims
-    simdevB = NetdevSimDev(3)
+    simdevB = BpfNetdevSimDev(3)
     simB1, simB2, simB3 = simdevB.nsims
     sims = (simA, simB1, simB2, simB3)
     simB = (simB1, simB2, simB3)

tools/testing/selftests/net/lib/py/nsim.py

@@ -21,8 +21,11 @@ class NetdevSim:
         if match and int(match.groups()[0]) != port_index + 1:
             raise Exception("netdevice name mismatches the expected one")
 
+        self.ifname = ifname
         self.nsimdev = nsimdev
         self.port_index = port_index
+        self.ns = ns
+        self.dfs_dir = "%s/ports/%u/" % (nsimdev.dfs_dir, port_index)
         ret = ip("-j link show dev %s" % ifname, ns=ns)
         self.dev = json.loads(ret.stdout)[0]
 
@@ -79,8 +82,10 @@ class NetdevSimDev:
 
         self.nsims = []
         for port_index in range(port_count):
-            self.nsims.append(NetdevSim(self, port_index, ifnames[port_index],
-                                        ns=ns))
+            self.nsims.append(self._make_port(port_index, ifnames[port_index]))
+
+    def _make_port(self, port_index, ifname):
+        return NetdevSim(self, port_index, ifname, self.ns)
 
     def get_ifnames(self):
         ifnames = []