src/machine/operation.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <sys/wait.h>
   4
   5 #include "alloc-util.h"
   6 #include "fd-util.h"
   7 #include "operation.h"
   8 #include "process-util.h"
   9
  10 static int operation_done(sd_event_source *s, const siginfo_t *si, void *userdata) {
  11         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
  12         Operation *o = userdata;
  13         int r;
  14
  15         assert(o);
  16         assert(si);
  17
  18         log_debug("Operating " PID_FMT " is now complete with code=%s status=%i",
  19                   o->pid,
  20                   sigchld_code_to_string(si->si_code), si->si_status);
  21
  22         o->pid = 0;
  23
  24         if (si->si_code != CLD_EXITED) {
  25                 r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
  26                 goto fail;
  27         }
  28
  29         if (si->si_status == EXIT_SUCCESS)
  30                 r = 0;
  31         else if (read(o->errno_fd, &r, sizeof(r)) != sizeof(r)) { /* Try to acquire error code for failed operation */
  32                 r = sd_bus_error_setf(&error, SD_BUS_ERROR_FAILED, "Child failed.");
  33                 goto fail;
  34         }
  35
  36         if (o->done) {
  37                 /* A completion routine is set for this operation, call it. */
  38                 r = o->done(o, r, &error);
  39                 if (r < 0) {
  40                         if (!sd_bus_error_is_set(&error))
  41                                 sd_bus_error_set_errno(&error, r);
  42
  43                         goto fail;
  44                 }
  45
  46         } else {
  47                 /* The default operation when done is to simply return an error on failure or an empty success
  48                  * message on success. */
  49                 if (r < 0) {
  50                         sd_bus_error_set_errno(&error, r);
  51                         goto fail;
  52                 }
  53
  54                 r = sd_bus_reply_method_return(o->message, NULL);
  55                 if (r < 0)
  56                         log_error_errno(r, "Failed to reply to message: %m");
  57         }
  58
  59         operation_free(o);
  60         return 0;
  61
  62 fail:
  63         r = sd_bus_reply_method_error(o->message, &error);
  64         if (r < 0)
  65                 log_error_errno(r, "Failed to reply to message: %m");
  66
  67         operation_free(o);
  68         return 0;
  69 }
  70
  71 int operation_new(Manager *manager, Machine *machine, pid_t child, sd_bus_message *message, int errno_fd, Operation **ret) {
  72         Operation *o;
  73         int r;
  74
  75         assert(manager);
  76         assert(child > 1);
  77         assert(message);
  78         assert(errno_fd >= 0);
  79
  80         o = new0(Operation, 1);
  81         if (!o)
  82                 return -ENOMEM;
  83
  84         o->extra_fd = -1;
  85
  86         r = sd_event_add_child(manager->event, &o->event_source, child, WEXITED, operation_done, o);
  87         if (r < 0) {
  88                 free(o);
  89                 return r;
  90         }
  91
  92         o->pid = child;
  93         o->message = sd_bus_message_ref(message);
  94         o->errno_fd = errno_fd;
  95
  96         LIST_PREPEND(operations, manager->operations, o);
  97         manager->n_operations++;
  98         o->manager = manager;
  99
 100         if (machine) {
 101                 LIST_PREPEND(operations_by_machine, machine->operations, o);
 102                 o->machine = machine;
 103         }
 104
 105         log_debug("Started new operation " PID_FMT ".", child);
 106
 107         /* At this point we took ownership of both the child and the errno file descriptor! */
 108
 109         if (ret)
 110                 *ret = o;
 111
 112         return 0;
 113 }
 114
 115 Operation *operation_free(Operation *o) {
 116         if (!o)
 117                 return NULL;
 118
 119         sd_event_source_unref(o->event_source);
 120
 121         safe_close(o->errno_fd);
 122         safe_close(o->extra_fd);
 123
 124         if (o->pid > 1)
 125                 (void) sigkill_wait(o->pid);
 126
 127         sd_bus_message_unref(o->message);
 128
 129         if (o->manager) {
 130                 LIST_REMOVE(operations, o->manager->operations, o);
 131                 o->manager->n_operations--;
 132         }
 133
 134         if (o->machine)
 135                 LIST_REMOVE(operations_by_machine, o->machine->operations, o);
 136
 137         return mfree(o);
 138 }