test/py: add a networking test

This tests:
- dhcp (if indicated by boardenv file).
- Static IP network setup (if provided by boardenv file).
- Ping.
- TFTP get.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

test/py/tests/test_net.py

+# Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+#
+# SPDX-License-Identifier: GPL-2.0
+
+# Test various network-related functionality, such as the dhcp, ping, and
+# tftpboot commands.
+
+import pytest
+import u_boot_utils
+
+'''
+Note: This test relies on boardenv_* containing configuration values to define
+which the network environment available for testing. Without this, this test
+will be automatically skipped.
+
+For example:
+
+# Any commands that need to be executed prior to testing,
+# to get the network hardware into an operational state.
+#
+# If no commands are required, this variable may be omitted, or set to an
+# empty list.
+env__net_pre_commands = [
+    "usb start",
+]
+
+# True if a DHCP server is attached to the network, and should be tested.
+# If DHCP testing is not possible or desired, this variable may be omitted or
+# set to False.
+env__net_dhcp_server = True
+
+# A list of environment variables that should be set in order to configure a
+# static IP. If solely relying on DHCP, this variable may be omitted or set to
+# an empty list.
+env__net_static_env_vars = [
+    ("ipaddr", "10.0.0.100"),
+    ("netmask", "255.255.255.0"),
+    ("serverip", "10.0.0.1"),
+]
+
+# Details regarding a file that may be read from a TFTP server. This variable
+# may be omitted or set to None if TFTP testing is not possible or desired.
+env__net_tftp_readable_file = {
+    "fn": "ubtest-readable.bin",
+    "size": 5058624,
+    "crc32": "c2244b26",
+}
+'''
+
+net_set_up = False
+
+def test_net_pre_commands(u_boot_console):
+    '''Execute any commands required to enable network hardware.
+
+    These commands are provided by the boardenv_* file; see the comment at the
+    beginning of this file.
+    '''
+
+    cmds = u_boot_console.config.env.get('env__net_pre_commands', None)
+    if not cmds:
+        pytest.skip('No network pre-commands defined')
+
+    for cmd in cmds:
+        u_boot_console.run_command(cmd)
+
+@pytest.mark.buildconfigspec('cmd_dhcp')
+def test_net_dhcp(u_boot_console):
+    '''Test the dhcp command.
+
+    The boardenv_* file may be used to enable/disable this test; see the
+    comment at the beginning of this file.
+    '''
+
+    test_dhcp = u_boot_console.config.env.get('env__net_dhcp_server', False)
+    if not test_dhcp:
+        pytest.skip('No DHCP server available')
+
+    u_boot_console.run_command('setenv autoload no')
+    output = u_boot_console.run_command('dhcp')
+    assert 'DHCP client bound to address ' in output
+
+    global net_set_up
+    net_set_up = True
+
+@pytest.mark.buildconfigspec('net')
+def test_net_setup_static(u_boot_console):
+    '''Set up a static IP configuration.
+
+    The configuration is provided by the boardenv_* file; see the comment at
+    the beginning of this file.
+    '''
+
+    env_vars = u_boot_console.config.env.get('env__net_static_env_vars', None)
+    if not env_vars:
+        pytest.skip('No static network configuration is defined')
+
+    for (var, val) in env_vars:
+        u_boot_console.run_command('setenv %s %s' % (var, val))
+
+    global net_set_up
+    net_set_up = True
+
+@pytest.mark.buildconfigspec('cmd_ping')
+def test_net_ping(u_boot_console):
+    '''Test the ping command.
+
+    The $serverip (as set up by either test_net_dhcp or test_net_setup_static)
+    is pinged. The test validates that the host is alive, as reported by the
+    ping command's output.
+    '''
+
+    if not net_set_up:
+        pytest.skip("Network not initialized")
+
+    output = u_boot_console.run_command('ping $serverip')
+    assert 'is alive' in output
+
+@pytest.mark.buildconfigspec('cmd_net')
+def test_net_tftpboot(u_boot_console):
+    '''Test the tftpboot command.
+
+    A file is downloaded from the TFTP server, its size and optionally its
+    CRC32 are validated.
+
+    The details of the file to download are provided by the boardenv_* file;
+    see the comment at the beginning of this file.
+    '''
+
+    if not net_set_up:
+        pytest.skip("Network not initialized")
+
+    f = u_boot_console.config.env.get('env__net_tftp_readable_file', None)
+    if not f:
+        pytest.skip('No TFTP readable file to read')
+
+    addr = u_boot_utils.find_ram_base(u_boot_console)
+    fn = f['fn']
+    output = u_boot_console.run_command('tftpboot %x %s' % (addr, fn))
+    expected_text = 'Bytes transferred = '
+    sz = f.get('size', None)
+    if sz:
+        expected_text += '%d' % sz
+    assert expected_text in output
+
+    expected_crc = f.get('crc32', None)
+    if not expected_crc:
+        return
+
+    if u_boot_console.config.buildconfig.get('config_cmd_crc32', 'n') != 'y':
+        return
+
+    output = u_boot_console.run_command('crc32 %x $filesize' % addr)
+    assert expected_crc in output