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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5 ***/
   6
   7 #include <pthread.h>
   8 #include <sys/socket.h>
   9
  10 #include "sd-bus.h"
  11
  12 #include "bus-error.h"
  13 #include "bus-kernel.h"
  14 #include "bus-match.h"
  15 #include "def.h"
  16 #include "hashmap.h"
  17 #include "list.h"
  18 #include "prioq.h"
  19 #include "refcnt.h"
  20 #include "socket-util.h"
  21 #include "util.h"
  22
  23 struct reply_callback {
  24         sd_bus_message_handler_t callback;
  25         usec_t timeout_usec; /* this is a relative timeout until we reach the BUS_HELLO state, and an absolute one right after */
  26         uint64_t cookie;
  27         unsigned prioq_idx;
  28 };
  29
  30 struct filter_callback {
  31         sd_bus_message_handler_t callback;
  32
  33         unsigned last_iteration;
  34
  35         LIST_FIELDS(struct filter_callback, callbacks);
  36 };
  37
  38 struct match_callback {
  39         sd_bus_message_handler_t callback;
  40         sd_bus_message_handler_t install_callback;
  41
  42         sd_bus_slot *install_slot; /* The AddMatch() call */
  43
  44         unsigned last_iteration;
  45
  46         char *match_string;
  47
  48         struct bus_match_node *match_node;
  49 };
  50
  51 struct node {
  52         char *path;
  53         struct node *parent;
  54         LIST_HEAD(struct node, child);
  55         LIST_FIELDS(struct node, siblings);
  56
  57         LIST_HEAD(struct node_callback, callbacks);
  58         LIST_HEAD(struct node_vtable, vtables);
  59         LIST_HEAD(struct node_enumerator, enumerators);
  60         LIST_HEAD(struct node_object_manager, object_managers);
  61 };
  62
  63 struct node_callback {
  64         struct node *node;
  65
  66         bool is_fallback;
  67         sd_bus_message_handler_t callback;
  68
  69         unsigned last_iteration;
  70
  71         LIST_FIELDS(struct node_callback, callbacks);
  72 };
  73
  74 struct node_enumerator {
  75         struct node *node;
  76
  77         sd_bus_node_enumerator_t callback;
  78
  79         unsigned last_iteration;
  80
  81         LIST_FIELDS(struct node_enumerator, enumerators);
  82 };
  83
  84 struct node_object_manager {
  85         struct node *node;
  86
  87         LIST_FIELDS(struct node_object_manager, object_managers);
  88 };
  89
  90 struct node_vtable {
  91         struct node *node;
  92
  93         char *interface;
  94         bool is_fallback;
  95         const sd_bus_vtable *vtable;
  96         sd_bus_object_find_t find;
  97
  98         unsigned last_iteration;
  99
 100         LIST_FIELDS(struct node_vtable, vtables);
 101 };
 102
 103 struct vtable_member {
 104         const char *path;
 105         const char *interface;
 106         const char *member;
 107         struct node_vtable *parent;
 108         unsigned last_iteration;
 109         const sd_bus_vtable *vtable;
 110 };
 111
 112 typedef enum BusSlotType {
 113         BUS_REPLY_CALLBACK,
 114         BUS_FILTER_CALLBACK,
 115         BUS_MATCH_CALLBACK,
 116         BUS_NODE_CALLBACK,
 117         BUS_NODE_ENUMERATOR,
 118         BUS_NODE_VTABLE,
 119         BUS_NODE_OBJECT_MANAGER,
 120         _BUS_SLOT_INVALID = -1,
 121 } BusSlotType;
 122
 123 struct sd_bus_slot {
 124         unsigned n_ref;
 125         sd_bus *bus;
 126         void *userdata;
 127         sd_bus_destroy_t destroy_callback;
 128         BusSlotType type:5;
 129
 130         /* Slots can be "floating" or not. If they are not floating (the usual case) then they reference the bus object
 131          * they are associated with. This means the bus object stays allocated at least as long as there is a slot
 132          * around associated with it. If it is floating, then the slot's lifecycle is bound to the lifecycle of the
 133          * bus: it will be disconnected from the bus when the bus is destroyed, and it keeping the slot reffed hence
 134          * won't mean the bus stays reffed too. Internally this means the reference direction is reversed: floating
 135          * slots objects are referenced by the bus object, and not vice versa. */
 136         bool floating:1;
 137
 138         bool match_added:1;
 139         char *description;
 140
 141         LIST_FIELDS(sd_bus_slot, slots);
 142
 143         union {
 144                 struct reply_callback reply_callback;
 145                 struct filter_callback filter_callback;
 146                 struct match_callback match_callback;
 147                 struct node_callback node_callback;
 148                 struct node_enumerator node_enumerator;
 149                 struct node_object_manager node_object_manager;
 150                 struct node_vtable node_vtable;
 151         };
 152 };
 153
 154 enum bus_state {
 155         BUS_UNSET,
 156         BUS_WATCH_BIND,      /* waiting for the socket to appear via inotify */
 157         BUS_OPENING,         /* the kernel's connect() is still not ready */
 158         BUS_AUTHENTICATING,  /* we are currently in the "SASL" authorization phase of dbus */
 159         BUS_HELLO,           /* we are waiting for the Hello() response */
 160         BUS_RUNNING,
 161         BUS_CLOSING,
 162         BUS_CLOSED,
 163         _BUS_STATE_MAX,
 164 };
 165
 166 static inline bool BUS_IS_OPEN(enum bus_state state) {
 167         return state > BUS_UNSET && state < BUS_CLOSING;
 168 }
 169
 170 enum bus_auth {
 171         _BUS_AUTH_INVALID,
 172         BUS_AUTH_EXTERNAL,
 173         BUS_AUTH_ANONYMOUS
 174 };
 175
 176 struct sd_bus {
 177         /* We use atomic ref counting here since sd_bus_message
 178            objects retain references to their originating sd_bus but
 179            we want to allow them to be processed in a different
 180            thread. We won't provide full thread safety, but only the
 181            bare minimum that makes it possible to use sd_bus and
 182            sd_bus_message objects independently and on different
 183            threads as long as each object is used only once at the
 184            same time. */
 185         RefCount 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 is_system:1;
 206         bool is_user:1;
 207         bool allow_interactive_authorization:1;
 208         bool exit_on_disconnect:1;
 209         bool exited:1;
 210         bool exit_triggered:1;
 211         bool is_local:1;
 212         bool watch_bind:1;
 213         bool is_monitor:1;
 214         bool accept_fd:1;
 215         bool attach_timestamp:1;
 216         bool connected_signal:1;
 217
 218         int use_memfd;
 219
 220         void *rbuffer;
 221         size_t rbuffer_size;
 222
 223         sd_bus_message **rqueue;
 224         unsigned rqueue_size;
 225         size_t rqueue_allocated;
 226
 227         sd_bus_message **wqueue;
 228         unsigned wqueue_size;
 229         size_t windex;
 230         size_t wqueue_allocated;
 231
 232         uint64_t cookie;
 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         char *machine;
 250         pid_t nspid;
 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         size_t auth_rbegin;
 261         struct iovec auth_iovec[3];
 262         unsigned auth_index;
 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
 271         uint64_t creds_mask;
 272
 273         int *fds;
 274         size_t n_fds;
 275
 276         char *exec_path;
 277         char **exec_argv;
 278
 279         unsigned iteration_counter;
 280
 281         /* We do locking around the memfd cache, since we want to
 282          * allow people to process a sd_bus_message in a different
 283          * thread then it was generated on and free it there. Since
 284          * adding something to the memfd cache might happen when a
 285          * message is released, we hence need to protect this bit with
 286          * a mutex. */
 287         pthread_mutex_t memfd_cache_mutex;
 288         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 289         unsigned n_memfd_cache;
 290
 291         pid_t original_pid;
 292         pid_t busexec_pid;
 293
 294         sd_event_source *input_io_event_source;
 295         sd_event_source *output_io_event_source;
 296         sd_event_source *time_event_source;
 297         sd_event_source *quit_event_source;
 298         sd_event_source *inotify_event_source;
 299         sd_event *event;
 300         int event_priority;
 301
 302         sd_bus_message *current_message;
 303         sd_bus_slot *current_slot;
 304         sd_bus_message_handler_t current_handler;
 305         void *current_userdata;
 306
 307         sd_bus **default_bus_ptr;
 308         pid_t tid;
 309
 310         char *cgroup_root;
 311
 312         char *description;
 313         char *patch_sender;
 314
 315         sd_bus_track *track_queue;
 316
 317         LIST_HEAD(sd_bus_slot, slots);
 318         LIST_HEAD(sd_bus_track, tracks);
 319
 320         int *inotify_watches;
 321         size_t n_inotify_watches;
 322 };
 323
 324 /* For method calls we time-out at 25s, like in the D-Bus reference implementation */
 325 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 326
 327 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 328  * with enough entropy yet and might delay the boot */
 329 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 330
 331 #define BUS_WQUEUE_MAX (192*1024)
 332 #define BUS_RQUEUE_MAX (192*1024)
 333
 334 #define BUS_MESSAGE_SIZE_MAX (128*1024*1024)
 335 #define BUS_AUTH_SIZE_MAX (64*1024)
 336
 337 #define BUS_CONTAINER_DEPTH 128
 338
 339 /* Defined by the specification as maximum size of an array in
 340  * bytes */
 341 #define BUS_ARRAY_MAX_SIZE 67108864
 342
 343 #define BUS_FDS_MAX 1024
 344
 345 #define BUS_EXEC_ARGV_MAX 256
 346
 347 bool interface_name_is_valid(const char *p) _pure_;
 348 bool service_name_is_valid(const char *p) _pure_;
 349 char* service_name_startswith(const char *a, const char *b);
 350 bool member_name_is_valid(const char *p) _pure_;
 351 bool object_path_is_valid(const char *p) _pure_;
 352 char *object_path_startswith(const char *a, const char *b) _pure_;
 353
 354 bool namespace_complex_pattern(const char *pattern, const char *value) _pure_;
 355 bool path_complex_pattern(const char *pattern, const char *value) _pure_;
 356
 357 bool namespace_simple_pattern(const char *pattern, const char *value) _pure_;
 358 bool path_simple_pattern(const char *pattern, const char *value) _pure_;
 359
 360 int bus_message_type_from_string(const char *s, uint8_t *u) _pure_;
 361 const char *bus_message_type_to_string(uint8_t u) _pure_;
 362
 363 #define error_name_is_valid interface_name_is_valid
 364
 365 sd_bus *bus_resolve(sd_bus *bus);
 366
 367 int bus_ensure_running(sd_bus *bus);
 368 int bus_start_running(sd_bus *bus);
 369 int bus_next_address(sd_bus *bus);
 370
 371 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m);
 372
 373 int bus_rqueue_make_room(sd_bus *bus);
 374
 375 bool bus_pid_changed(sd_bus *bus);
 376
 377 char *bus_address_escape(const char *v);
 378
 379 int bus_attach_io_events(sd_bus *b);
 380 int bus_attach_inotify_event(sd_bus *b);
 381
 382 void bus_close_inotify_fd(sd_bus *b);
 383 void bus_close_io_fds(sd_bus *b);
 384
 385 #define OBJECT_PATH_FOREACH_PREFIX(prefix, path)                        \
 386         for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
 387              _slash && !(_slash[(_slash) == (prefix)] = 0);             \
 388              _slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
 389
 390 /* If we are invoking callbacks of a bus object, ensure unreffing the
 391  * bus from the callback doesn't destroy the object we are working
 392  * on */
 393 #define BUS_DONT_DESTROY(bus) \
 394         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 395
 396 int bus_set_address_system(sd_bus *bus);
 397 int bus_set_address_user(sd_bus *bus);
 398 int bus_set_address_system_remote(sd_bus *b, const char *host);
 399 int bus_set_address_system_machine(sd_bus *b, const char *machine);
 400
 401 int bus_get_root_path(sd_bus *bus);
 402
 403 int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 404
 405 #define bus_assert_return(expr, r, error)                               \
 406         do {                                                            \
 407                 if (!assert_log(expr, #expr))                           \
 408                         return sd_bus_error_set_errno(error, r);        \
 409         } while (false)
 410
 411 void bus_enter_closing(sd_bus *bus);
 412
 413 void bus_set_state(sd_bus *bus, enum bus_state state);