summaryrefslogtreecommitdiff
path: root/src/machine/operation.c
blob: c966d0d21c07da26493cf2bcc9b7fe48a1887884 (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
142
143
144
145
146
147
148
149
150
151
/***
  This file is part of systemd.

  Copyright 2016 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include "alloc-util.h"
#include "fd-util.h"
#include "operation.h"
#include "process-util.h"

static int operation_done(sd_event_source *s, const siginfo_t *si, void *userdata) {
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        Operation *o = userdata;
        int r;

        assert(o);
        assert(si);

        log_debug("Operating " PID_FMT " is now complete with code=%s status=%i",
                  o->pid,
                  sigchld_code_to_string(si->si_code), si->si_status);

        o->pid = 0;

        if (si->si_code != CLD_EXITED) {
                r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
                goto fail;
        }

        if (si->si_status == EXIT_SUCCESS)
                r = 0;
        else if (read(o->errno_fd, &r, sizeof(r)) != sizeof(r)) { /* Try to acquire error code for failed operation */
                r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child failed.");
                goto fail;
        }

        if (o->done) {
                /* A completion routine is set for this operation, call it. */
                r = o->done(o, r, &error);
                if (r < 0) {
                        if (!sd_bus_error_is_set(&error))
                                sd_bus_error_set_errno(&error, r);

                        goto fail;
                }

        } else {
                /* The default operation when done is to simply return an error on failure or an empty success
                 * message on success. */
                if (r < 0)
                        goto fail;

                r = sd_bus_reply_method_return(o->message, NULL);
                if (r < 0)
                        log_error_errno(r, "Failed to reply to message: %m");
        }

        operation_free(o);
        return 0;

fail:
        r = sd_bus_reply_method_error(o->message, &error);
        if (r < 0)
                log_error_errno(r, "Failed to reply to message: %m");

        operation_free(o);
        return 0;
}

int operation_new(Manager *manager, Machine *machine, pid_t child, sd_bus_message *message, int errno_fd, Operation **ret) {
        Operation *o;
        int r;

        assert(manager);
        assert(child > 1);
        assert(message);
        assert(errno_fd >= 0);

        o = new0(Operation, 1);
        if (!o)
                return -ENOMEM;

        o->extra_fd = -1;

        r = sd_event_add_child(manager->event, &o->event_source, child, WEXITED, operation_done, o);
        if (r < 0) {
                free(o);
                return r;
        }

        o->pid = child;
        o->message = sd_bus_message_ref(message);
        o->errno_fd = errno_fd;

        LIST_PREPEND(operations, manager->operations, o);
        manager->n_operations++;
        o->manager = manager;

        if (machine) {
                LIST_PREPEND(operations_by_machine, machine->operations, o);
                o->machine = machine;
        }

        log_debug("Started new operation " PID_FMT ".", child);

        /* At this point we took ownership of both the child and the errno file descriptor! */

        if (ret)
                *ret = o;

        return 0;
}

Operation *operation_free(Operation *o) {
        if (!o)
                return NULL;

        sd_event_source_unref(o->event_source);

        safe_close(o->errno_fd);
        safe_close(o->extra_fd);

        if (o->pid > 1)
                (void) sigkill_wait(o->pid);

        sd_bus_message_unref(o->message);

        if (o->manager) {
                LIST_REMOVE(operations, o->manager->operations, o);
                o->manager->n_operations--;
        }

        if (o->machine)
                LIST_REMOVE(operations_by_machine, o->machine->operations, o);

        return mfree(o);
}