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1 | package PVE::Systemd; | |
2 | ||
3 | use strict; | |
4 | use warnings; | |
5 | ||
6 | use Net::DBus qw(dbus_uint32 dbus_uint64); | |
7 | use Net::DBus::Callback; | |
8 | use Net::DBus::Reactor; | |
9 | ||
10 | # $code should take the parameters ($interface, $reactor, $finish_callback). | |
11 | # | |
12 | # $finish_callback can be used by dbus-signal-handlers to stop the reactor. | |
13 | # | |
14 | # In order to even start waiting on the reactor, $code needs to return undef, if it returns a | |
15 | # defined value instead, it is assumed that this is the result already and we can stop. | |
16 | # NOTE: This calls the dbus main loop and must not be used when another dbus | |
17 | # main loop is being used as we need to wait signals. | |
18 | sub systemd_call($;$) { | |
19 | my ($code, $timeout) = @_; | |
20 | ||
21 | my $bus = Net::DBus->system(); | |
22 | my $reactor = Net::DBus::Reactor->main(); | |
23 | ||
24 | my $service = $bus->get_service('org.freedesktop.systemd1'); | |
25 | my $if = $service->get_object('/org/freedesktop/systemd1', 'org.freedesktop.systemd1.Manager'); | |
26 | ||
27 | my ($finished, $current_result, $timer); | |
28 | my $finish_callback = sub { | |
29 | my ($result) = @_; | |
30 | ||
31 | $current_result = $result; | |
32 | ||
33 | $finished = 1; | |
34 | ||
35 | if (defined($timer)) { | |
36 | $reactor->remove_timeout($timer); | |
37 | $timer = undef; | |
38 | } | |
39 | ||
40 | if (defined($reactor)) { | |
41 | $reactor->shutdown(); | |
42 | $reactor = undef; | |
43 | } | |
44 | }; | |
45 | ||
46 | my $result = $code->($if, $reactor, $finish_callback); | |
47 | # Are we done immediately? | |
48 | return $result if defined $result; | |
49 | ||
50 | # Alterantively $finish_callback may have been called already? | |
51 | return $current_result if $finished; | |
52 | ||
53 | # Otherwise wait: | |
54 | my $on_timeout = sub { | |
55 | $finish_callback->(undef); | |
56 | die "timeout waiting on systemd\n"; | |
57 | }; | |
58 | $timer = $reactor->add_timeout($timeout * 1000, Net::DBus::Callback->new(method => $on_timeout)) | |
59 | if defined($timeout); | |
60 | ||
61 | $reactor->run(); | |
62 | $reactor->shutdown() if defined($reactor); # $finish_callback clears it | |
63 | ||
64 | return $current_result; | |
65 | } | |
66 | ||
67 | # Polling the job status instead doesn't work because this doesn't give us the | |
68 | # distinction between success and failure. | |
69 | # | |
70 | # Note that the description is mandatory for security reasons. | |
71 | sub enter_systemd_scope { | |
72 | my ($unit, $description, %extra) = @_; | |
73 | die "missing description\n" if !defined($description); | |
74 | ||
75 | my $timeout = delete $extra{timeout}; | |
76 | ||
77 | $unit .= '.scope'; | |
78 | my $properties = [ [PIDs => [dbus_uint32($$)]] ]; | |
79 | ||
80 | foreach my $key (keys %extra) { | |
81 | if ($key eq 'Slice' || $key eq 'KillMode') { | |
82 | push @{$properties}, [$key, $extra{$key}]; | |
83 | } elsif ($key eq 'CPUShares') { | |
84 | push @{$properties}, [$key, dbus_uint64($extra{$key})]; | |
85 | } elsif ($key eq 'CPUQuota') { | |
86 | push @{$properties}, ['CPUQuotaPerSecUSec', | |
87 | dbus_uint64($extra{$key} * 10_000)]; | |
88 | } else { | |
89 | die "Don't know how to encode $key for systemd scope\n"; | |
90 | } | |
91 | } | |
92 | ||
93 | systemd_call(sub { | |
94 | my ($if, $reactor, $finish_cb) = @_; | |
95 | ||
96 | my $job; | |
97 | ||
98 | $if->connect_to_signal('JobRemoved', sub { | |
99 | my ($id, $removed_job, $signaled_unit, $result) = @_; | |
100 | return if $signaled_unit ne $unit || $removed_job ne $job; | |
101 | if ($result ne 'done') { | |
102 | # I seem to remember $reactor->run() catching die() at some point? | |
103 | # so better call finish to be sure...: | |
104 | $finish_cb->(0); | |
105 | die "systemd job failed\n"; | |
106 | } else { | |
107 | $finish_cb->(1); | |
108 | } | |
109 | }); | |
110 | ||
111 | $job = $if->StartTransientUnit($unit, 'fail', $properties, []); | |
112 | ||
113 | return undef; | |
114 | }, $timeout); | |
115 | } | |
116 | ||
117 | sub wait_for_unit_removed($;$) { | |
118 | my ($unit, $timeout) = @_; | |
119 | ||
120 | systemd_call(sub { | |
121 | my ($if, $reactor, $finish_cb) = @_; | |
122 | ||
123 | my $unit_obj = eval { $if->GetUnit($unit) }; | |
124 | return 1 if !$unit_obj; | |
125 | ||
126 | $if->connect_to_signal('UnitRemoved', sub { | |
127 | my ($id, $removed_unit) = @_; | |
128 | $finish_cb->(1) if $removed_unit eq $unit_obj; | |
129 | }); | |
130 | ||
131 | # Deal with what we lost between GetUnit() and connecting to UnitRemoved: | |
132 | my $unit_obj_new = eval { $if->GetUnit($unit) }; | |
133 | if (!$unit_obj_new) { | |
134 | return 1; | |
135 | } | |
136 | ||
137 | return undef; | |
138 | }, $timeout); | |
139 | } | |
140 | ||
141 | 1; |