src/interfaces/hostnamed/hostnamed.c

   1 /*
   2  * Copyright (c) 2014 Ian Sutton <ian@kremlin.cc>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <unistd.h>
  18 #include <limits.h>
  19 #include <signal.h>
  20
  21 #include <sys/param.h>
  22 #include <sys/sysctl.h>
  23 #include <string.h>
  24
  25 #include <glib/gprintf.h>
  26 #include <glib-unix.h>
  27
  28 #include "hostnamed-gen.h"
  29 #include "hostnamed.h"
  30
  31 GPtrArray *hostnamed_freeable;
  32 Hostname1 *hostnamed_interf;
  33
  34 GMainLoop *hostnamed_loop;
  35
  36 guint bus_descriptor;
  37 gboolean dbus_interface_exported; /* reliable because of gdbus operational guarantees */
  38
  39 /* --- begin method/property/dbus signal code --- */
  40
  41 /* add any sysctl strings that suggest virtualization here */
  42 const gchar* vmstring_list[] = {
  43     "QEMU Virtual CPU",
  44     "SmartDC HVM",
  45     "KVM",
  46     "VirtualBox"
  47 };
  48
  49 static gboolean is_vm;
  50
  51 static gboolean
  52 on_handle_set_hostname(Hostname1 *hn1_passed_interf,
  53                        GDBusMethodInvocation *invoc,
  54                        const gchar *greet,
  55                        gpointer data) {
  56     return FALSE;
  57 }
  58
  59 static gboolean
  60 on_handle_set_static_hostname(Hostname1 *hn1_passed_interf,
  61                               GDBusMethodInvocation *invoc,
  62                               const gchar *greet,
  63                               gpointer data) {
  64     return FALSE;
  65 }
  66
  67 static gboolean
  68 on_handle_set_pretty_hostname(Hostname1 *hn1_passed_interf,
  69                               GDBusMethodInvocation *invoc,
  70                               const gchar *greet,
  71                               gpointer data) {
  72     return FALSE;
  73 }
  74
  75 static gboolean
  76 on_handle_set_chassis(Hostname1 *hn1_passed_interf,
  77                       GDBusMethodInvocation *invoc,
  78                       const gchar *greet,
  79                       gpointer data) {
  80     return FALSE;
  81 }
  82
  83 static gboolean
  84 on_handle_set_icon_name(Hostname1 *hn1_passed_interf,
  85                         GDBusMethodInvocation *invoc,
  86                         const gchar *greet,
  87                         gpointer data) {
  88     return FALSE;
  89 }
  90
  91 /* note: all hostnamed/hostname1's properties are read-only,
  92  * and do not need set_ functions, gdbus-codegen realized
  93  * this from the XML and handled the to-be error of trying
  94  * to set a read-only property's value
  95  */
  96
  97 const gchar *
  98 our_get_hostname() {
  99
 100     gchar *hostname_buf, *ret;
 101     size_t hostname_divider;
 102
 103     hostname_buf = (gchar*) g_malloc0(MAXHOSTNAMELEN);
 104     ret          = (gchar*) g_malloc0(MAXHOSTNAMELEN);
 105
 106     g_ptr_array_add(hostnamed_freeable, hostname_buf);
 107     g_ptr_array_add(hostnamed_freeable, ret);
 108
 109     if(gethostname(hostname_buf, MAXHOSTNAMELEN) || g_strcmp0(hostname_buf, "") == 0)
 110         return "localhost";
 111
 112     hostname_divider = strcspn(hostname_buf, ".");
 113
 114     return strncpy(ret, hostname_buf, hostname_divider);
 115 }
 116
 117 const gchar *
 118 our_get_static_hostname() {
 119
 120     const gchar *pretty_hostname;
 121     const gchar *ret;
 122
 123     pretty_hostname = our_get_pretty_hostname();
 124
 125     if(g_strcmp0(pretty_hostname, "") == 0)
 126         ret = our_get_hostname();
 127
 128     else if((ret = g_hostname_to_ascii(pretty_hostname))) {
 129
 130         g_ptr_array_add(hostnamed_freeable, (gpointer)ret);
 131         return ret;
 132     }
 133
 134     return ret;
 135 }
 136
 137 const gchar *
 138 our_get_pretty_hostname() {
 139
 140     GKeyFile *config;
 141     gchar *ret;
 142
 143     config = g_key_file_new();
 144
 145     if(g_key_file_load_from_file(config, "/etc/systemd_compat.conf", G_KEY_FILE_NONE, NULL)
 146         && (ret = g_key_file_get_value(config, "hostnamed", "PrettyHostname", NULL))) { /* ret might need to be freed, docs dont specify but i am suspicious */
 147
 148         g_key_file_unref(config);
 149         return ret;
 150     }
 151
 152     if(config)
 153         g_free(config);
 154
 155     return "";
 156 }
 157
 158 const gchar *
 159 our_get_chassis() {
 160
 161     char *hwproduct, *hwmodel;
 162     size_t hwproduct_size, hwmodel_size;
 163     int hwproduct_name[2], hwmodel_name[2];
 164
 165     hwproduct_name[0] = CTL_HW;
 166     hwproduct_name[1] = HW_PRODUCT;
 167
 168     hwmodel_name[0] = CTL_HW;
 169     hwmodel_name[1] = HW_MODEL;
 170
 171     /* pass NULL buffer to check size first, then pass hw to be filled according to freshly-set hw_size */
 172     if(sysctl(&hwproduct_name, 2, NULL, &hwproduct_size, NULL, 0) || sysctl(&hwproduct_name, 2, hwproduct, &hwproduct_size, NULL, 0))
 173         return "desktop"; /* TODO error properly here */
 174
 175     if(sysctl(&hwmodel_name, 2, NULL, &hwmodel_size, NULL, 0) || sysctl(&hwmodel_name, 2, hwmodel, &hwmodel_size, NULL, 0))
 176         return "desktop"; /* TODO error properly here */
 177
 178     if(test_against_known_vm_strings(hwproduct) || test_against_known_vm_strings(hwmodel))
 179         return "vm"; /*TODO differentiate between VMs (hardware virt, seperate kernel) and containers (paravirt, shared kernel)
 180
 181     /* TODO: test for laptop, if not, dmidecode for desktop vs. server
 182      *       probably move this code to vm test func and set a global after running it early, once */
 183
 184     return "desktop";
 185 }
 186
 187 const gchar *
 188 our_get_icon_name() {
 189
 190     return "TODO";
 191 }
 192
 193 const gchar *
 194 our_get_kernel_name() {
 195
 196     return "TODO";
 197 }
 198
 199 const gchar *
 200 our_get_kernel_version() {
 201
 202     return "TODO";
 203 }
 204
 205 const gchar *
 206 our_get_kernel_release() {
 207
 208     return "TODO";
 209 }
 210
 211 const gchar *
 212 our_get_os_cpename() {
 213
 214     return "TODO";
 215 }
 216
 217 const gchar *
 218 our_get_os_pretty_name() {
 219
 220     return "TODO";
 221 }
 222
 223 /* --- end method/property/dbus signal code, begin bus/name handlers --- */
 224
 225 static void hostnamed_on_bus_acquired(GDBusConnection *conn,
 226                             const gchar *name,
 227                             gpointer user_data) {
 228
 229     g_printf("got bus/name, exporting %s's interface...\n", name);
 230
 231     hostnamed_interf = hostname1_skeleton_new();
 232
 233     /* attach function pointers to generated struct's method handlers */
 234     g_signal_connect(hostnamed_interf, "handle-set-hostname", G_CALLBACK(on_handle_set_hostname), NULL);
 235     g_signal_connect(hostnamed_interf, "handle-set-static-hostname", G_CALLBACK(on_handle_set_static_hostname), NULL);
 236     g_signal_connect(hostnamed_interf, "handle-set-pretty-hostname", G_CALLBACK(on_handle_set_pretty_hostname), NULL);
 237     g_signal_connect(hostnamed_interf, "handle-set-chassis", G_CALLBACK(on_handle_set_chassis), NULL);
 238     g_signal_connect(hostnamed_interf, "handle-set-icon-name", G_CALLBACK(on_handle_set_icon_name), NULL);
 239
 240     /* set our properties before export */
 241     hostname1_set_hostname(hostnamed_interf, our_get_hostname());
 242     hostname1_set_static_hostname(hostnamed_interf, our_get_static_hostname());
 243     hostname1_set_pretty_hostname(hostnamed_interf, our_get_pretty_hostname());
 244     hostname1_set_chassis(hostnamed_interf, our_get_chassis());
 245     hostname1_set_icon_name(hostnamed_interf, our_get_icon_name());
 246     hostname1_set_kernel_name(hostnamed_interf, our_get_kernel_name());
 247     hostname1_set_kernel_version(hostnamed_interf, our_get_kernel_version());
 248     hostname1_set_kernel_release(hostnamed_interf, our_get_kernel_release());
 249     hostname1_set_operating_system_cpename(hostnamed_interf, our_get_os_cpename());
 250     hostname1_set_operating_system_pretty_name(hostnamed_interf, our_get_os_pretty_name());
 251
 252     if(!g_dbus_interface_skeleton_export(G_DBUS_INTERFACE_SKELETON(hostnamed_interf),
 253                                          conn,
 254                                          "/org/freedesktop/hostname1",
 255                                          NULL)) {
 256
 257         g_printf("failed to export %s's interface!\n", name); /* unusual edge case, TODO check errno */
 258         hostnamed_mem_clean();
 259
 260     } else {
 261
 262         dbus_interface_exported = TRUE;
 263         g_printf("exported %s's interface on the system bus...\n", name);
 264     }
 265 }
 266
 267 static void hostnamed_on_name_acquired(GDBusConnection *conn,
 268                                        const gchar *name,
 269                                        gpointer user_data) {
 270
 271     g_printf("success!\n");
 272 }
 273
 274 static void hostnamed_on_name_lost(GDBusConnection *conn,
 275                                    const gchar *name,
 276                                    gpointer user_data) {
 277
 278     if(!conn) {
 279
 280         g_printf("failed to connect to the system bus while trying to acquire name '%s': either dbus-daemon isn't running or we don't have permission to push names and/or their interfaces to it.\n", name);
 281         hostnamed_mem_clean();
 282     }
 283
 284     g_printf("lost name %s, exiting...\n", name);
 285
 286     hostnamed_mem_clean();
 287 }
 288
 289 /* --- end bus/name handlers, begin misc unix functions --- */
 290
 291 /* safe call to clean and then exit
 292  * this stops our GMainLoop safely before letting main() return */
 293 void hostnamed_mem_clean() {
 294
 295     g_printf("exiting...\n");
 296
 297     if(dbus_interface_exported)
 298         g_dbus_interface_skeleton_unexport(G_DBUS_INTERFACE_SKELETON(hostnamed_interf));
 299
 300     if(g_main_loop_is_running(hostnamed_loop))
 301         g_main_loop_quit(hostnamed_loop);
 302
 303 }
 304
 305 /* wrapper for glib's unix signal handling; called only once if terminatating signal is raised against us */
 306 gboolean unix_sig_terminate_handler(gpointer data) {
 307
 308     g_printf("caught SIGINT/HUP/TERM, exiting\n");
 309
 310     hostnamed_mem_clean();
 311     return G_SOURCE_REMOVE;
 312 }
 313
 314 void set_signal_handlers() {
 315
 316     /* we don't care about its descriptor, we never need to unregister these */
 317     g_unix_signal_add(SIGINT,  unix_sig_terminate_handler, NULL);
 318     g_unix_signal_add(SIGHUP,  unix_sig_terminate_handler, NULL);
 319     g_unix_signal_add(SIGTERM, unix_sig_terminate_handler, NULL);
 320
 321     /* TODO: the "only once" guarantee only counts towards specific signals.
 322      *       make sure calling a SIGINT and SIGHUP doesn't cause term_handler()
 323      *       to be called twice */
 324 }
 325
 326 int main() {
 327
 328     set_signal_handlers();
 329
 330     hostnamed_loop = g_main_loop_new(NULL, TRUE);
 331     hostnamed_freeable = g_ptr_array_new();
 332
 333     bus_descriptor = g_bus_own_name(G_BUS_TYPE_SYSTEM,
 334                                    "org.freedesktop.hostname1",
 335                                    G_BUS_NAME_OWNER_FLAGS_NONE,
 336                                    hostnamed_on_bus_acquired,
 337                                    hostnamed_on_name_acquired,
 338                                    hostnamed_on_name_lost,
 339                                    NULL,
 340                                    NULL);
 341
 342     g_main_loop_run(hostnamed_loop);
 343     /* runs until single g_main_loop_quit() call is raised inside <interface>_mem_clean() */
 344     g_main_loop_unref(hostnamed_loop);
 345
 346     /* guaranteed unownable */
 347     g_bus_unown_name(bus_descriptor);
 348
 349     /* at this point no operations can occur with our data, it is safe to free it + its container */
 350     g_ptr_array_free(hostnamed_freeable, TRUE);
 351
 352     return 0;
 353 }
 354
 355 gboolean test_against_known_vm_strings(gchar *sysctl_string) {
 356
 357     unsigned int i;
 358
 359     if(is_vm)
 360         return TRUE;
 361
 362     for(; i < G_N_ELEMENTS(vmstring_list); i++)
 363         if(strcasestr(sysctl_string, vmstring_list[i]))
 364             return (is_vm = TRUE) ? TRUE : FALSE;
 365
 366          return FALSE;
 367 }
 368
 369 /* TODO figure out DMI variables on obsd */
 370 /*static gchar *guess_icon_name() {
 371
 372     gchar *filebuf = NULL;
 373     gchar *ret = NULL;
 374
 375     #if defined(__i386__) || defined(__x86_64__)
 376
 377        Taken with a few minor changes from systemd's hostnamed.c,
 378        copyright 2011 Lennart Poettering.
 379
 380        See the SMBIOS Specification 2.7.1 section 7.4.1 for
 381        details about the values listed here:
 382
 383        http://www.dmtf.org/sites/default/files/standards/documents/DSP0134_2.7.1.pdf
 384
 385
 386     if (g_file_get_contents ("/sys/class/dmi/id/chassis_type", &filebuf, NULL, NULL)) {
 387         switch (g_ascii_strtoull (filebuf, NULL, 10)) {
 388         case 0x3:
 389         case 0x4:
 390         case 0x5:
 391         case 0x6:
 392         case 0x7:
 393             ret = g_strdup ("computer-desktop");
 394             goto out;
 395         case 0x9:
 396         case 0xA:
 397         case 0xE:
 398             ret = g_strdup ("computer-laptop");
 399             goto out;
 400         case 0x11:
 401         case 0x17:
 402         case 0x1C:
 403         case 0x1D:
 404             ret = g_strdup ("computer-server");
 405             goto out;
 406         }
 407     }
 408     #endif
 409     ret = g_strdup ("computer");
 410   out:
 411     g_free (filebuf);
 412     return ret;
 413 }*/
 414