man/vtable-example.c

   1 /* SPDX-License-Identifier: MIT-0 */
   2
   3 #define _GNU_SOURCE 1
   4 #include <errno.h>
   5 #include <stdbool.h>
   6 #include <stddef.h>
   7 #include <stdlib.h>
   8 #include <stdio.h>
   9 #include <systemd/sd-bus.h>
  10
  11 #define _cleanup_(f) __attribute__((cleanup(f)))
  12
  13 typedef struct object {
  14   char *name;
  15   uint32_t number;
  16 } object;
  17
  18 static int method(sd_bus_message *m, void *userdata, sd_bus_error *error) {
  19   int r;
  20
  21   printf("Got called with userdata=%p\n", userdata);
  22
  23   if (sd_bus_message_is_method_call(m,
  24                                     "org.freedesktop.systemd.VtableExample",
  25                                     "Method4"))
  26     return 1;
  27
  28   const char *string;
  29   r = sd_bus_message_read(m, "s", &string);
  30   if (r < 0) {
  31     fprintf(stderr, "sd_bus_message_read() failed: %s\n", strerror(-r));
  32     return 0;
  33   }
  34
  35   r = sd_bus_reply_method_return(m, "s", string);
  36   if (r < 0) {
  37     fprintf(stderr, "sd_bus_reply_method_return() failed: %s\n", strerror(-r));
  38     return 0;
  39   }
  40
  41   return 1;
  42 }
  43
  44 static const sd_bus_vtable vtable[] = {
  45         SD_BUS_VTABLE_START(0),
  46         SD_BUS_METHOD(
  47             "Method1", "s", "s", method, 0),
  48         SD_BUS_METHOD_WITH_NAMES_OFFSET(
  49             "Method2",
  50             "so", SD_BUS_PARAM(string) SD_BUS_PARAM(path),
  51             "s", SD_BUS_PARAM(returnstring),
  52             method, offsetof(object, number),
  53             SD_BUS_VTABLE_DEPRECATED),
  54         SD_BUS_METHOD_WITH_ARGS_OFFSET(
  55             "Method3",
  56             SD_BUS_ARGS("s", string, "o", path),
  57             SD_BUS_RESULT("s", returnstring),
  58             method, offsetof(object, number),
  59             SD_BUS_VTABLE_UNPRIVILEGED),
  60         SD_BUS_METHOD_WITH_ARGS(
  61             "Method4",
  62             SD_BUS_NO_ARGS,
  63             SD_BUS_NO_RESULT,
  64             method,
  65             SD_BUS_VTABLE_UNPRIVILEGED),
  66         SD_BUS_SIGNAL(
  67             "Signal1",
  68             "so",
  69             0),
  70         SD_BUS_SIGNAL_WITH_NAMES(
  71             "Signal2",
  72             "so", SD_BUS_PARAM(string) SD_BUS_PARAM(path),
  73             0),
  74         SD_BUS_SIGNAL_WITH_ARGS(
  75             "Signal3",
  76             SD_BUS_ARGS("s", string, "o", path),
  77             0),
  78         SD_BUS_WRITABLE_PROPERTY(
  79             "AutomaticStringProperty", "s", NULL, NULL,
  80             offsetof(object, name),
  81             SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
  82         SD_BUS_WRITABLE_PROPERTY(
  83             "AutomaticIntegerProperty", "u", NULL, NULL,
  84             offsetof(object, number),
  85             SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION),
  86         SD_BUS_VTABLE_END
  87 };
  88
  89 int main(int argc, char **argv) {
  90   _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
  91   int r;
  92
  93   sd_bus_default(&bus);
  94
  95   object object = { .number = 666 };
  96   object.name = strdup("name");
  97   if (!object.name) {
  98     fprintf(stderr, "OOM\n");
  99     return EXIT_FAILURE;
 100   }
 101
 102   r = sd_bus_add_object_vtable(bus, NULL,
 103                                "/org/freedesktop/systemd/VtableExample",
 104                                "org.freedesktop.systemd.VtableExample",
 105                                vtable,
 106                                &object);
 107   if (r < 0) {
 108     fprintf(stderr, "sd_bus_add_object_vtable() failed: %s\n", strerror(-r));
 109     return EXIT_FAILURE;
 110   }
 111
 112   r = sd_bus_request_name(bus,
 113                           "org.freedesktop.systemd.VtableExample",
 114                           0);
 115   if (r < 0) {
 116     fprintf(stderr, "sd_bus_request_name() failed: %s\n", strerror(-r));
 117     return EXIT_FAILURE;
 118   }
 119
 120   for (;;) {
 121     r = sd_bus_wait(bus, UINT64_MAX);
 122     if (r < 0) {
 123       fprintf(stderr, "sd_bus_wait() failed: %s\n", strerror(-r));
 124       return EXIT_FAILURE;
 125     }
 126
 127     r = sd_bus_process(bus, NULL);
 128     if (r < 0) {
 129       fprintf(stderr, "sd_bus_process() failed: %s\n", strerror(-r));
 130       return EXIT_FAILURE;
 131     }
 132   }
 133
 134   r = sd_bus_release_name(bus, "org.freedesktop.systemd.VtableExample");
 135   if (r < 0) {
 136     fprintf(stderr, "sd_bus_release_name() failed: %s\n", strerror(-r));
 137     return EXIT_FAILURE;
 138   }
 139
 140   free(object.name);
 141
 142   return 0;
 143 }