src/libsystemd/sd-bus/bus-internal.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include "sd-id128.h"
   5
   6 #include "bus-forward.h"
   7 #include "bus-kernel.h"
   8 #include "bus-match.h"
   9 #include "constants.h"
  10 #include "list.h"
  11 #include "runtime-scope.h"
  12 #include "socket-util.h"
  13
  14 /* Note that we use the new /run prefix here (instead of /var/run) since we require them to be aliases and
  15  * that way we become independent of /var being mounted */
  16 #define DEFAULT_SYSTEM_BUS_ADDRESS "unix:path=/run/dbus/system_bus_socket"
  17 #define DEFAULT_USER_BUS_ADDRESS_FMT "unix:path=%s/bus"
  18
  19 typedef struct BusReplyCallback {
  20         sd_bus_message_handler_t callback;
  21         usec_t timeout_usec; /* this is a relative timeout until we reach the BUS_HELLO state, and an absolute one right after */
  22         uint64_t cookie;
  23         unsigned prioq_idx;
  24 } BusReplyCallback;
  25
  26 typedef struct BusFilterCallback {
  27         sd_bus_message_handler_t callback;
  28
  29         unsigned last_iteration;
  30
  31         LIST_FIELDS(BusFilterCallback, callbacks);
  32 } BusFilterCallback;
  33
  34 typedef struct BusNode {
  35         char *path;
  36         BusNode *parent;
  37         LIST_HEAD(BusNode, child);
  38         LIST_FIELDS(BusNode, siblings);
  39
  40         LIST_HEAD(BusNodeCallback, callbacks);
  41         LIST_HEAD(BusNodeVTable, vtables);
  42         LIST_HEAD(BusNodeEnumerator, enumerators);
  43         LIST_HEAD(BusNodeObjectManager, object_managers);
  44 } BusNode;
  45
  46 typedef struct BusNodeCallback {
  47         BusNode *node;
  48
  49         bool is_fallback;
  50         unsigned last_iteration;
  51
  52         sd_bus_message_handler_t callback;
  53
  54         LIST_FIELDS(BusNodeCallback, callbacks);
  55 } BusNodeCallback;
  56
  57 typedef struct BusNodeEnumerator {
  58         BusNode *node;
  59
  60         sd_bus_node_enumerator_t callback;
  61
  62         unsigned last_iteration;
  63
  64         LIST_FIELDS(BusNodeEnumerator, enumerators);
  65 } BusNodeEnumerator;
  66
  67 typedef struct BusNodeObjectManager {
  68         BusNode *node;
  69
  70         LIST_FIELDS(BusNodeObjectManager, object_managers);
  71 } BusNodeObjectManager;
  72
  73 typedef struct BusNodeVTable {
  74         BusNode *node;
  75
  76         bool is_fallback;
  77         unsigned last_iteration;
  78
  79         char *interface;
  80         const sd_bus_vtable *vtable;
  81         sd_bus_object_find_t find;
  82
  83         LIST_FIELDS(BusNodeVTable, vtables);
  84 } BusNodeVTable;
  85
  86 typedef struct BusVTableMember {
  87         const char *path;
  88         const char *interface;
  89         const char *member;
  90         BusNodeVTable *parent;
  91         unsigned last_iteration;
  92         const sd_bus_vtable *vtable;
  93 } BusVTableMember;
  94
  95 typedef enum BusSlotType {
  96         BUS_REPLY_CALLBACK,
  97         BUS_FILTER_CALLBACK,
  98         BUS_MATCH_CALLBACK,
  99         BUS_NODE_CALLBACK,
 100         BUS_NODE_ENUMERATOR,
 101         BUS_NODE_VTABLE,
 102         BUS_NODE_OBJECT_MANAGER,
 103         _BUS_SLOT_INVALID = -EINVAL,
 104 } BusSlotType;
 105
 106 typedef struct sd_bus_slot {
 107         unsigned n_ref;
 108         BusSlotType type:8;
 109
 110         /* Slots can be "floating" or not. If they are not floating (the usual case) then they reference the
 111          * bus object they are associated with. This means the bus object stays allocated at least as long as
 112          * there is a slot around associated with it. If it is floating, then the slot's lifecycle is bound
 113          * to the lifecycle of the bus: it will be disconnected from the bus when the bus is destroyed, and
 114          * it keeping the slot reffed hence won't mean the bus stays reffed too. Internally this means the
 115          * reference direction is reversed: floating slots objects are referenced by the bus object, and not
 116          * vice versa. */
 117         bool floating;
 118         bool match_added;
 119
 120         sd_bus *bus;
 121         void *userdata;
 122         sd_bus_destroy_t destroy_callback;
 123
 124         char *description;
 125
 126         LIST_FIELDS(sd_bus_slot, slots);
 127
 128         union {
 129                 BusReplyCallback reply_callback;
 130                 BusFilterCallback filter_callback;
 131                 BusMatchCallback match_callback;
 132                 BusNodeCallback node_callback;
 133                 BusNodeEnumerator node_enumerator;
 134                 BusNodeObjectManager node_object_manager;
 135                 BusNodeVTable node_vtable;
 136         };
 137 } sd_bus_slot;
 138
 139 typedef enum BusState {
 140         BUS_UNSET,
 141         BUS_WATCH_BIND,      /* waiting for the socket to appear via inotify */
 142         BUS_OPENING,         /* the kernel's connect() is still not ready */
 143         BUS_AUTHENTICATING,  /* we are currently in the "SASL" authorization phase of dbus */
 144         BUS_HELLO,           /* we are waiting for the Hello() response */
 145         BUS_RUNNING,
 146         BUS_CLOSING,
 147         BUS_CLOSED,
 148         _BUS_STATE_MAX,
 149 } BusState;
 150
 151 static inline bool BUS_IS_OPEN(BusState state) {
 152         return state > BUS_UNSET && state < BUS_CLOSING;
 153 }
 154
 155 typedef enum BusAuth {
 156         _BUS_AUTH_INVALID,
 157         BUS_AUTH_EXTERNAL,
 158         BUS_AUTH_ANONYMOUS
 159 } BusAuth;
 160
 161 typedef struct sd_bus {
 162         unsigned n_ref;
 163
 164         BusState state;
 165         int input_fd, output_fd;
 166         int inotify_fd;
 167         int message_version;
 168         int message_endian;
 169
 170         bool can_fds;
 171         bool bus_client;
 172         bool ucred_valid;
 173         bool is_server;
 174         bool anonymous_auth;
 175         bool prefer_readv;
 176         bool prefer_writev;
 177         bool match_callbacks_modified;
 178         bool filter_callbacks_modified;
 179         bool nodes_modified;
 180         bool trusted;
 181         bool manual_peer_interface;
 182         bool allow_interactive_authorization;
 183         bool exit_on_disconnect;
 184         bool exited;
 185         bool exit_triggered;
 186         bool is_local;
 187         bool watch_bind;
 188         bool is_monitor;
 189         bool accept_fd;
 190         bool attach_timestamp;
 191         bool connected_signal;
 192         bool close_on_exit;
 193
 194         RuntimeScope runtime_scope;
 195
 196         int use_memfd;
 197
 198         void *rbuffer;
 199         size_t rbuffer_size;
 200
 201         sd_bus_message **rqueue;
 202         size_t rqueue_size;
 203
 204         sd_bus_message **wqueue;
 205         size_t wqueue_size;
 206         size_t windex;
 207
 208         uint64_t cookie;
 209         uint64_t read_counter; /* A counter for each incoming msg */
 210
 211         char *unique_name;
 212         uint64_t unique_id;
 213
 214         BusMatchNode match_callbacks;
 215         Prioq *reply_callbacks_prioq;
 216         OrderedHashmap *reply_callbacks;
 217         LIST_HEAD(BusFilterCallback, filter_callbacks);
 218
 219         Hashmap *nodes;
 220         Set *vtable_methods;
 221         Set *vtable_properties;
 222
 223         union sockaddr_union sockaddr;
 224         socklen_t sockaddr_size;
 225
 226         pid_t nspid;
 227         char *machine;
 228
 229         sd_id128_t server_id;
 230
 231         char *address;
 232         unsigned address_index;
 233
 234         uid_t connect_as_uid;
 235         gid_t connect_as_gid;
 236
 237         int last_connect_error;
 238
 239         BusAuth auth;
 240         unsigned auth_index;
 241         struct iovec auth_iovec[3];
 242         size_t auth_rbegin;
 243         char *auth_buffer;
 244         usec_t auth_timeout;
 245
 246         struct ucred ucred;
 247         char *label;
 248         gid_t *groups;
 249         size_t n_groups;
 250         union sockaddr_union sockaddr_peer;
 251         socklen_t sockaddr_size_peer;
 252         int pidfd;
 253
 254         uint64_t creds_mask;
 255
 256         int *fds;
 257         size_t n_fds;
 258
 259         char *exec_path;
 260         char **exec_argv;
 261
 262         /* We do locking around the memfd cache, since we want to
 263          * allow people to process a sd_bus_message in a different
 264          * thread then it was generated on and free it there. Since
 265          * adding something to the memfd cache might happen when a
 266          * message is released, we hence need to protect this bit with
 267          * a mutex. */
 268         pthread_mutex_t memfd_cache_mutex;
 269         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 270         unsigned n_memfd_cache;
 271
 272         uint64_t origin_id;
 273         pid_t busexec_pid;
 274
 275         unsigned iteration_counter;
 276
 277         sd_event_source *input_io_event_source;
 278         sd_event_source *output_io_event_source;
 279         sd_event_source *time_event_source;
 280         sd_event_source *quit_event_source;
 281         sd_event_source *inotify_event_source;
 282         sd_event *event;
 283         int event_priority;
 284
 285         pid_t tid;
 286
 287         sd_bus_message *current_message;
 288         sd_bus_slot *current_slot;
 289         sd_bus_message_handler_t current_handler;
 290         void *current_userdata;
 291
 292         sd_bus **default_bus_ptr;
 293
 294         char *description;
 295         char *patch_sender;
 296
 297         sd_bus_track *track_queue;
 298
 299         LIST_HEAD(sd_bus_slot, slots);
 300         LIST_HEAD(sd_bus_track, tracks);
 301
 302         int *inotify_watches;
 303         size_t n_inotify_watches;
 304
 305         /* zero means use value specified by $SYSTEMD_BUS_TIMEOUT= environment variable or built-in default */
 306         usec_t method_call_timeout;
 307 } sd_bus;
 308
 309 /* For method calls we timeout at 25s, like in the D-Bus reference implementation */
 310 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 311
 312 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 313  * with enough entropy yet and might delay the boot */
 314 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 315
 316 #define BUS_WQUEUE_MAX (384*1024)
 317 #define BUS_RQUEUE_MAX (384*1024)
 318
 319 #define BUS_MESSAGE_SIZE_MAX (128*1024*1024)
 320 #define BUS_AUTH_SIZE_MAX (64*1024)
 321 /* Note that the D-Bus specification states that bus paths shall have no size limit. We enforce here one
 322  * anyway, since truly unbounded strings are a security problem. The limit we pick is relatively large however,
 323  * to not clash unnecessarily with real-life applications. */
 324 #define BUS_PATH_SIZE_MAX (64*1024)
 325
 326 #define BUS_CONTAINER_DEPTH 128
 327
 328 /* Defined by the specification as maximum size of an array in bytes */
 329 #define BUS_ARRAY_MAX_SIZE 67108864
 330
 331 #define BUS_FDS_MAX 1024
 332
 333 #define BUS_EXEC_ARGV_MAX 256
 334
 335 bool interface_name_is_valid(const char *p) _pure_;
 336 bool service_name_is_valid(const char *p) _pure_;
 337 bool member_name_is_valid(const char *p) _pure_;
 338 bool object_path_is_valid(const char *p) _pure_;
 339
 340 char* object_path_startswith(const char *a, const char *b) _pure_;
 341
 342 bool namespace_complex_pattern(const char *pattern, const char *value) _pure_;
 343 bool path_complex_pattern(const char *pattern, const char *value) _pure_;
 344
 345 bool namespace_simple_pattern(const char *pattern, const char *value) _pure_;
 346 bool path_simple_pattern(const char *pattern, const char *value) _pure_;
 347
 348 int bus_message_type_from_string(const char *s, uint8_t *u);
 349 const char* bus_message_type_to_string(uint8_t u) _pure_;
 350
 351 #define error_name_is_valid interface_name_is_valid
 352
 353 sd_bus *bus_resolve(sd_bus *bus);
 354
 355 int bus_ensure_running(sd_bus *bus);
 356 int bus_start_running(sd_bus *bus);
 357 int bus_next_address(sd_bus *bus);
 358
 359 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m);
 360
 361 int bus_rqueue_make_room(sd_bus *bus);
 362
 363 bool bus_origin_changed(sd_bus *bus);
 364
 365 char* bus_address_escape(const char *v);
 366
 367 int bus_attach_io_events(sd_bus *b);
 368 int bus_attach_inotify_event(sd_bus *b);
 369
 370 void bus_close_inotify_fd(sd_bus *b);
 371 void bus_close_io_fds(sd_bus *b);
 372
 373 int bus_add_match_full(
 374                 sd_bus *bus,
 375                 sd_bus_slot **slot,
 376                 bool asynchronous,
 377                 const char *match,
 378                 sd_bus_message_handler_t callback,
 379                 sd_bus_message_handler_t install_callback,
 380                 void *userdata,
 381                 uint64_t timeout_usec);
 382
 383 #define OBJECT_PATH_FOREACH_PREFIX(prefix, path)                        \
 384         for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
 385              _slash && ((_slash[(_slash) == (prefix)] = 0), true);       \
 386              _slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
 387
 388 /* If we are invoking callbacks of a bus object, ensure unreffing the
 389  * bus from the callback doesn't destroy the object we are working on */
 390 #define BUS_DONT_DESTROY(bus) \
 391         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 392
 393 int bus_set_address_system(sd_bus *bus);
 394 int bus_set_address_user(sd_bus *bus);
 395 int bus_set_address_system_remote(sd_bus *b, const char *host);
 396 int bus_set_address_machine(sd_bus *b, RuntimeScope runtime_scope, const char *machine);
 397
 398 int bus_maybe_reply_error(sd_bus_message *m, int r, const sd_bus_error *e);
 399
 400 #define bus_assert_return(expr, r, error)                               \
 401         do {                                                            \
 402                 if (!assert_log(expr, #expr))                           \
 403                         return sd_bus_error_set_errno(error, r);        \
 404         } while (false)
 405
 406 void bus_enter_closing(sd_bus *bus);
 407
 408 void bus_set_state(sd_bus *bus, BusState state);