summaryrefslogtreecommitdiff
path: root/src/conf_mode/system_console.py
blob: 034cbee63bd4058ed41daa63f7daff40fe6d773f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
#!/usr/bin/env python3
#
# Copyright (C) 2020 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import re

from fileinput import input as replace_in_file
from vyos.config import Config
from vyos.util import call
from vyos.template import render
from vyos import ConfigError, airbag
airbag.enable()

by_bus_dir = '/dev/serial/by-bus'

def get_config():
    conf = Config()
    base = ['system', 'console']

    # retrieve configuration at once
    console = conf.get_config_dict(base)

    # bail out early if no serial console is configured
    if 'device' not in console.keys():
        return console

    # convert CLI values to system values
    for device in console['device'].keys():
        # no speed setting has been configured - use default value
        if not 'speed' in console['device'][device].keys():
            tmp = { 'speed': '' }
            if device.startswith('hvc'):
                tmp['speed'] = 38400
            else:
                tmp['speed'] = 115200

            console['device'][device].update(tmp)

        if device.startswith('usb'):
            # It is much easiert to work with the native ttyUSBn name when using
            # getty, but that name may change across reboots - depending on the
            # amount of connected devices. We will resolve the fixed device name
            # to its dynamic device file - and create a new dict entry for it.
            by_bus_device = f'{by_bus_dir}/{device}'
            if os.path.isdir(by_bus_dir) and os.path.exists(by_bus_device):
                tmp = os.path.basename(os.readlink(by_bus_device))
                # updating the dict must come as last step in the loop!
                console['device'][tmp] = console['device'].pop(device)

    return console

def verify(console):
    return None

def generate(console):
    base_dir = '/etc/systemd/system'
    # Remove all serial-getty configuration files in advance
    for root, dirs, files in os.walk(base_dir):
        for basename in files:
            if 'serial-getty' in basename:
                call(f'systemctl stop {basename}')
                os.unlink(os.path.join(root, basename))

    if not console:
        return None

    for device in console['device'].keys():
        config_file = base_dir + f'/serial-getty@{device}.service'
        getty_wants_symlink = base_dir + f'/getty.target.wants/serial-getty@{device}.service'

        render(config_file, 'getty/serial-getty.service.tmpl', console['device'][device])
        os.symlink(config_file, getty_wants_symlink)

    # GRUB
    # For existing serial line change speed (if necessary)
    # Only applys to ttyS0
    if 'ttyS0' not in console['device'].keys():
        return None

    speed = console['device']['ttyS0']['speed']
    grub_config = '/boot/grub/grub.cfg'
    if not os.path.isfile(grub_config):
        return None

    # stdin/stdout are redirected in replace_in_file(), thus print() is fine
    p = re.compile(r'^(.* console=ttyS0),[0-9]+(.*)$')
    for line in replace_in_file(grub_config, inplace=True):
        if line.startswith('serial --unit'):
            line = f'serial --unit=0 --speed={speed}\n'
        elif p.match(line):
            line = '{},{}{}\n'.format(p.search(line)[1], speed, p.search(line)[2])

        print(line, end='')

    return None

def apply(console):
    # reset screen blanking
    call('/usr/bin/setterm -blank 0 -powersave off -powerdown 0 -term linux </dev/tty1 >/dev/tty1 2>&1')

    # Reload systemd manager configuration
    call('systemctl daemon-reload')

    if not console:
        return None

    if 'powersave' in console.keys():
        # Configure screen blank powersaving on VGA console
        call('/usr/bin/setterm -blank 15 -powersave powerdown -powerdown 60 -term linux </dev/tty1 >/dev/tty1 2>&1')

    # Start getty process on configured serial interfaces
    for device in console['device'].keys():
        # Only start console if it exists on the running system. If a user
        # detaches a USB serial console and reboots - it should not fail!
        if os.path.exists(f'/dev/{device}'):
            call(f'systemctl start serial-getty@{device}.service')

    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)