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

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <pthread.h>
   5
   6 #include "sd-bus.h"
   7
   8 #include "bus-error.h"
   9 #include "bus-kernel.h"
  10 #include "bus-match.h"
  11 #include "constants.h"
  12 #include "hashmap.h"
  13 #include "list.h"
  14 #include "prioq.h"
  15 #include "runtime-scope.h"
  16 #include "socket-util.h"
  17 #include "time-util.h"
  18
  19 /* Note that we use the new /run prefix here (instead of /var/run) since we require them to be aliases and
  20  * that way we become independent of /var being mounted */
  21 #define DEFAULT_SYSTEM_BUS_ADDRESS "unix:path=/run/dbus/system_bus_socket"
  22 #define DEFAULT_USER_BUS_ADDRESS_FMT "unix:path=%s/bus"
  23
  24 struct reply_callback {
  25         sd_bus_message_handler_t callback;
  26         usec_t timeout_usec; /* this is a relative timeout until we reach the BUS_HELLO state, and an absolute one right after */
  27         uint64_t cookie;
  28         unsigned prioq_idx;
  29 };
  30
  31 struct filter_callback {
  32         sd_bus_message_handler_t callback;
  33
  34         unsigned last_iteration;
  35
  36         LIST_FIELDS(struct filter_callback, callbacks);
  37 };
  38
  39 struct match_callback {
  40         sd_bus_message_handler_t callback;
  41         sd_bus_message_handler_t install_callback;
  42
  43         sd_bus_slot *install_slot; /* The AddMatch() call */
  44
  45         unsigned last_iteration;
  46
  47         /* Don't dispatch this slot with messages that arrived in any iteration before or at the this
  48          * one. We use this to ensure that matches don't apply "retroactively" and confuse the caller:
  49          * only messages received after the match was installed will be considered. */
  50         uint64_t after;
  51
  52         char *match_string;
  53
  54         struct bus_match_node *match_node;
  55 };
  56
  57 struct node {
  58         char *path;
  59         struct node *parent;
  60         LIST_HEAD(struct node, child);
  61         LIST_FIELDS(struct node, siblings);
  62
  63         LIST_HEAD(struct node_callback, callbacks);
  64         LIST_HEAD(struct node_vtable, vtables);
  65         LIST_HEAD(struct node_enumerator, enumerators);
  66         LIST_HEAD(struct node_object_manager, object_managers);
  67 };
  68
  69 struct node_callback {
  70         struct node *node;
  71
  72         bool is_fallback:1;
  73         unsigned last_iteration;
  74
  75         sd_bus_message_handler_t callback;
  76
  77         LIST_FIELDS(struct node_callback, callbacks);
  78 };
  79
  80 struct node_enumerator {
  81         struct node *node;
  82
  83         sd_bus_node_enumerator_t callback;
  84
  85         unsigned last_iteration;
  86
  87         LIST_FIELDS(struct node_enumerator, enumerators);
  88 };
  89
  90 struct node_object_manager {
  91         struct node *node;
  92
  93         LIST_FIELDS(struct node_object_manager, object_managers);
  94 };
  95
  96 struct node_vtable {
  97         struct node *node;
  98
  99         bool is_fallback:1;
 100         unsigned last_iteration;
 101
 102         char *interface;
 103         const sd_bus_vtable *vtable;
 104         sd_bus_object_find_t find;
 105
 106         LIST_FIELDS(struct node_vtable, vtables);
 107 };
 108
 109 struct vtable_member {
 110         const char *path;
 111         const char *interface;
 112         const char *member;
 113         struct node_vtable *parent;
 114         unsigned last_iteration;
 115         const sd_bus_vtable *vtable;
 116 };
 117
 118 typedef enum BusSlotType {
 119         BUS_REPLY_CALLBACK,
 120         BUS_FILTER_CALLBACK,
 121         BUS_MATCH_CALLBACK,
 122         BUS_NODE_CALLBACK,
 123         BUS_NODE_ENUMERATOR,
 124         BUS_NODE_VTABLE,
 125         BUS_NODE_OBJECT_MANAGER,
 126         _BUS_SLOT_INVALID = -EINVAL,
 127 } BusSlotType;
 128
 129 struct sd_bus_slot {
 130         unsigned n_ref;
 131         BusSlotType type:8;
 132
 133         /* Slots can be "floating" or not. If they are not floating (the usual case) then they reference the
 134          * bus object they are associated with. This means the bus object stays allocated at least as long as
 135          * there is a slot around associated with it. If it is floating, then the slot's lifecycle is bound
 136          * to the lifecycle of the bus: it will be disconnected from the bus when the bus is destroyed, and
 137          * it keeping the slot reffed hence won't mean the bus stays reffed too. Internally this means the
 138          * reference direction is reversed: floating slots objects are referenced by the bus object, and not
 139          * vice versa. */
 140         bool floating;
 141         bool match_added;
 142
 143         sd_bus *bus;
 144         void *userdata;
 145         sd_bus_destroy_t destroy_callback;
 146
 147         char *description;
 148
 149         LIST_FIELDS(sd_bus_slot, slots);
 150
 151         union {
 152                 struct reply_callback reply_callback;
 153                 struct filter_callback filter_callback;
 154                 struct match_callback match_callback;
 155                 struct node_callback node_callback;
 156                 struct node_enumerator node_enumerator;
 157                 struct node_object_manager node_object_manager;
 158                 struct node_vtable node_vtable;
 159         };
 160 };
 161
 162 enum bus_state {
 163         BUS_UNSET,
 164         BUS_WATCH_BIND,      /* waiting for the socket to appear via inotify */
 165         BUS_OPENING,         /* the kernel's connect() is still not ready */
 166         BUS_AUTHENTICATING,  /* we are currently in the "SASL" authorization phase of dbus */
 167         BUS_HELLO,           /* we are waiting for the Hello() response */
 168         BUS_RUNNING,
 169         BUS_CLOSING,
 170         BUS_CLOSED,
 171         _BUS_STATE_MAX,
 172 };
 173
 174 static inline bool BUS_IS_OPEN(enum bus_state state) {
 175         return state > BUS_UNSET && state < BUS_CLOSING;
 176 }
 177
 178 enum bus_auth {
 179         _BUS_AUTH_INVALID,
 180         BUS_AUTH_EXTERNAL,
 181         BUS_AUTH_ANONYMOUS
 182 };
 183
 184 struct sd_bus {
 185         unsigned n_ref;
 186
 187         enum bus_state state;
 188         int input_fd, output_fd;
 189         int inotify_fd;
 190         int message_version;
 191         int message_endian;
 192
 193         bool can_fds:1;
 194         bool bus_client:1;
 195         bool ucred_valid:1;
 196         bool is_server:1;
 197         bool anonymous_auth:1;
 198         bool prefer_readv:1;
 199         bool prefer_writev:1;
 200         bool match_callbacks_modified:1;
 201         bool filter_callbacks_modified:1;
 202         bool nodes_modified:1;
 203         bool trusted:1;
 204         bool manual_peer_interface:1;
 205         bool allow_interactive_authorization:1;
 206         bool exit_on_disconnect:1;
 207         bool exited:1;
 208         bool exit_triggered:1;
 209         bool is_local:1;
 210         bool watch_bind:1;
 211         bool is_monitor:1;
 212         bool accept_fd:1;
 213         bool attach_timestamp:1;
 214         bool connected_signal:1;
 215         bool close_on_exit:1;
 216
 217         RuntimeScope runtime_scope;
 218
 219         signed int use_memfd:2;
 220
 221         void *rbuffer;
 222         size_t rbuffer_size;
 223
 224         sd_bus_message **rqueue;
 225         size_t rqueue_size;
 226
 227         sd_bus_message **wqueue;
 228         size_t wqueue_size;
 229         size_t windex;
 230
 231         uint64_t cookie;
 232         uint64_t read_counter; /* A counter for each incoming msg */
 233
 234         char *unique_name;
 235         uint64_t unique_id;
 236
 237         struct bus_match_node match_callbacks;
 238         Prioq *reply_callbacks_prioq;
 239         OrderedHashmap *reply_callbacks;
 240         LIST_HEAD(struct filter_callback, filter_callbacks);
 241
 242         Hashmap *nodes;
 243         Hashmap *vtable_methods;
 244         Hashmap *vtable_properties;
 245
 246         union sockaddr_union sockaddr;
 247         socklen_t sockaddr_size;
 248
 249         pid_t nspid;
 250         char *machine;
 251
 252         sd_id128_t server_id;
 253
 254         char *address;
 255         unsigned address_index;
 256
 257         int last_connect_error;
 258
 259         enum bus_auth auth;
 260         unsigned auth_index;
 261         struct iovec auth_iovec[3];
 262         size_t auth_rbegin;
 263         char *auth_buffer;
 264         usec_t auth_timeout;
 265
 266         struct ucred ucred;
 267         char *label;
 268         gid_t *groups;
 269         size_t n_groups;
 270         union sockaddr_union sockaddr_peer;
 271         socklen_t sockaddr_size_peer;
 272         int pidfd;
 273
 274         uint64_t creds_mask;
 275
 276         int *fds;
 277         size_t n_fds;
 278
 279         char *exec_path;
 280         char **exec_argv;
 281
 282         /* We do locking around the memfd cache, since we want to
 283          * allow people to process a sd_bus_message in a different
 284          * thread then it was generated on and free it there. Since
 285          * adding something to the memfd cache might happen when a
 286          * message is released, we hence need to protect this bit with
 287          * a mutex. */
 288         pthread_mutex_t memfd_cache_mutex;
 289         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 290         unsigned n_memfd_cache;
 291
 292         uint64_t origin_id;
 293         pid_t busexec_pid;
 294
 295         unsigned iteration_counter;
 296
 297         sd_event_source *input_io_event_source;
 298         sd_event_source *output_io_event_source;
 299         sd_event_source *time_event_source;
 300         sd_event_source *quit_event_source;
 301         sd_event_source *inotify_event_source;
 302         sd_event *event;
 303         int event_priority;
 304
 305         pid_t tid;
 306
 307         sd_bus_message *current_message;
 308         sd_bus_slot *current_slot;
 309         sd_bus_message_handler_t current_handler;
 310         void *current_userdata;
 311
 312         sd_bus **default_bus_ptr;
 313
 314         char *description;
 315         char *patch_sender;
 316
 317         sd_bus_track *track_queue;
 318
 319         LIST_HEAD(sd_bus_slot, slots);
 320         LIST_HEAD(sd_bus_track, tracks);
 321
 322         int *inotify_watches;
 323         size_t n_inotify_watches;
 324
 325         /* zero means use value specified by $SYSTEMD_BUS_TIMEOUT= environment variable or built-in default */
 326         usec_t method_call_timeout;
 327 };
 328
 329 /* For method calls we timeout at 25s, like in the D-Bus reference implementation */
 330 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 331
 332 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 333  * with enough entropy yet and might delay the boot */
 334 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 335
 336 #define BUS_WQUEUE_MAX (384*1024)
 337 #define BUS_RQUEUE_MAX (384*1024)
 338
 339 #define BUS_MESSAGE_SIZE_MAX (128*1024*1024)
 340 #define BUS_AUTH_SIZE_MAX (64*1024)
 341 /* Note that the D-Bus specification states that bus paths shall have no size limit. We enforce here one
 342  * anyway, since truly unbounded strings are a security problem. The limit we pick is relatively large however,
 343  * to not clash unnecessarily with real-life applications. */
 344 #define BUS_PATH_SIZE_MAX (64*1024)
 345
 346 #define BUS_CONTAINER_DEPTH 128
 347
 348 /* Defined by the specification as maximum size of an array in bytes */
 349 #define BUS_ARRAY_MAX_SIZE 67108864
 350
 351 #define BUS_FDS_MAX 1024
 352
 353 #define BUS_EXEC_ARGV_MAX 256
 354
 355 bool interface_name_is_valid(const char *p) _pure_;
 356 bool service_name_is_valid(const char *p) _pure_;
 357 bool member_name_is_valid(const char *p) _pure_;
 358 bool object_path_is_valid(const char *p) _pure_;
 359
 360 char *object_path_startswith(const char *a, const char *b) _pure_;
 361
 362 bool namespace_complex_pattern(const char *pattern, const char *value) _pure_;
 363 bool path_complex_pattern(const char *pattern, const char *value) _pure_;
 364
 365 bool namespace_simple_pattern(const char *pattern, const char *value) _pure_;
 366 bool path_simple_pattern(const char *pattern, const char *value) _pure_;
 367
 368 int bus_message_type_from_string(const char *s, uint8_t *u);
 369 const char *bus_message_type_to_string(uint8_t u) _pure_;
 370
 371 #define error_name_is_valid interface_name_is_valid
 372
 373 sd_bus *bus_resolve(sd_bus *bus);
 374
 375 int bus_ensure_running(sd_bus *bus);
 376 int bus_start_running(sd_bus *bus);
 377 int bus_next_address(sd_bus *bus);
 378
 379 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m);
 380
 381 int bus_rqueue_make_room(sd_bus *bus);
 382
 383 bool bus_origin_changed(sd_bus *bus);
 384
 385 char *bus_address_escape(const char *v);
 386
 387 int bus_attach_io_events(sd_bus *b);
 388 int bus_attach_inotify_event(sd_bus *b);
 389
 390 void bus_close_inotify_fd(sd_bus *b);
 391 void bus_close_io_fds(sd_bus *b);
 392
 393 int bus_add_match_full(
 394                 sd_bus *bus,
 395                 sd_bus_slot **slot,
 396                 bool asynchronous,
 397                 const char *match,
 398                 sd_bus_message_handler_t callback,
 399                 sd_bus_message_handler_t install_callback,
 400                 void *userdata,
 401                 uint64_t timeout_usec);
 402
 403 #define OBJECT_PATH_FOREACH_PREFIX(prefix, path)                        \
 404         for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
 405              _slash && ((_slash[(_slash) == (prefix)] = 0), true);       \
 406              _slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
 407
 408 /* If we are invoking callbacks of a bus object, ensure unreffing the
 409  * bus from the callback doesn't destroy the object we are working on */
 410 #define BUS_DONT_DESTROY(bus) \
 411         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 412
 413 int bus_set_address_system(sd_bus *bus);
 414 int bus_set_address_user(sd_bus *bus);
 415 int bus_set_address_system_remote(sd_bus *b, const char *host);
 416 int bus_set_address_machine(sd_bus *b, RuntimeScope runtime_scope, const char *machine);
 417
 418 int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 419
 420 #define bus_assert_return(expr, r, error)                               \
 421         do {                                                            \
 422                 if (!assert_log(expr, #expr))                           \
 423                         return sd_bus_error_set_errno(error, r);        \
 424         } while (false)
 425
 426 void bus_enter_closing(sd_bus *bus);
 427
 428 void bus_set_state(sd_bus *bus, enum bus_state state);