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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <pthread.h>
   5 #include <sys/socket.h>
   6
   7 #include "sd-bus.h"
   8
   9 #include "bus-error.h"
  10 #include "bus-kernel.h"
  11 #include "bus-match.h"
  12 #include "def.h"
  13 #include "hashmap.h"
  14 #include "list.h"
  15 #include "prioq.h"
  16 #include "refcnt.h"
  17 #include "socket-util.h"
  18 #include "util.h"
  19
  20 struct reply_callback {
  21         sd_bus_message_handler_t callback;
  22         usec_t timeout_usec; /* this is a relative timeout until we reach the BUS_HELLO state, and an absolute one right after */
  23         uint64_t cookie;
  24         unsigned prioq_idx;
  25 };
  26
  27 struct filter_callback {
  28         sd_bus_message_handler_t callback;
  29
  30         unsigned last_iteration;
  31
  32         LIST_FIELDS(struct filter_callback, callbacks);
  33 };
  34
  35 struct match_callback {
  36         sd_bus_message_handler_t callback;
  37         sd_bus_message_handler_t install_callback;
  38
  39         sd_bus_slot *install_slot; /* The AddMatch() call */
  40
  41         unsigned last_iteration;
  42
  43         char *match_string;
  44
  45         struct bus_match_node *match_node;
  46 };
  47
  48 struct node {
  49         char *path;
  50         struct node *parent;
  51         LIST_HEAD(struct node, child);
  52         LIST_FIELDS(struct node, siblings);
  53
  54         LIST_HEAD(struct node_callback, callbacks);
  55         LIST_HEAD(struct node_vtable, vtables);
  56         LIST_HEAD(struct node_enumerator, enumerators);
  57         LIST_HEAD(struct node_object_manager, object_managers);
  58 };
  59
  60 struct node_callback {
  61         struct node *node;
  62
  63         bool is_fallback;
  64         sd_bus_message_handler_t callback;
  65
  66         unsigned last_iteration;
  67
  68         LIST_FIELDS(struct node_callback, callbacks);
  69 };
  70
  71 struct node_enumerator {
  72         struct node *node;
  73
  74         sd_bus_node_enumerator_t callback;
  75
  76         unsigned last_iteration;
  77
  78         LIST_FIELDS(struct node_enumerator, enumerators);
  79 };
  80
  81 struct node_object_manager {
  82         struct node *node;
  83
  84         LIST_FIELDS(struct node_object_manager, object_managers);
  85 };
  86
  87 struct node_vtable {
  88         struct node *node;
  89
  90         char *interface;
  91         bool is_fallback;
  92         const sd_bus_vtable *vtable;
  93         sd_bus_object_find_t find;
  94
  95         unsigned last_iteration;
  96
  97         LIST_FIELDS(struct node_vtable, vtables);
  98 };
  99
 100 struct vtable_member {
 101         const char *path;
 102         const char *interface;
 103         const char *member;
 104         struct node_vtable *parent;
 105         unsigned last_iteration;
 106         const sd_bus_vtable *vtable;
 107 };
 108
 109 typedef enum BusSlotType {
 110         BUS_REPLY_CALLBACK,
 111         BUS_FILTER_CALLBACK,
 112         BUS_MATCH_CALLBACK,
 113         BUS_NODE_CALLBACK,
 114         BUS_NODE_ENUMERATOR,
 115         BUS_NODE_VTABLE,
 116         BUS_NODE_OBJECT_MANAGER,
 117         _BUS_SLOT_INVALID = -1,
 118 } BusSlotType;
 119
 120 struct sd_bus_slot {
 121         unsigned n_ref;
 122         sd_bus *bus;
 123         void *userdata;
 124         sd_bus_destroy_t destroy_callback;
 125         BusSlotType type:5;
 126
 127         /* Slots can be "floating" or not. If they are not floating (the usual case) then they reference the bus object
 128          * they are associated with. This means the bus object stays allocated at least as long as there is a slot
 129          * around associated with it. If it is floating, then the slot's lifecycle is bound to the lifecycle of the
 130          * bus: it will be disconnected from the bus when the bus is destroyed, and it keeping the slot reffed hence
 131          * won't mean the bus stays reffed too. Internally this means the reference direction is reversed: floating
 132          * slots objects are referenced by the bus object, and not vice versa. */
 133         bool floating:1;
 134
 135         bool match_added:1;
 136         char *description;
 137
 138         LIST_FIELDS(sd_bus_slot, slots);
 139
 140         union {
 141                 struct reply_callback reply_callback;
 142                 struct filter_callback filter_callback;
 143                 struct match_callback match_callback;
 144                 struct node_callback node_callback;
 145                 struct node_enumerator node_enumerator;
 146                 struct node_object_manager node_object_manager;
 147                 struct node_vtable node_vtable;
 148         };
 149 };
 150
 151 enum bus_state {
 152         BUS_UNSET,
 153         BUS_WATCH_BIND,      /* waiting for the socket to appear via inotify */
 154         BUS_OPENING,         /* the kernel's connect() is still not ready */
 155         BUS_AUTHENTICATING,  /* we are currently in the "SASL" authorization phase of dbus */
 156         BUS_HELLO,           /* we are waiting for the Hello() response */
 157         BUS_RUNNING,
 158         BUS_CLOSING,
 159         BUS_CLOSED,
 160         _BUS_STATE_MAX,
 161 };
 162
 163 static inline bool BUS_IS_OPEN(enum bus_state state) {
 164         return state > BUS_UNSET && state < BUS_CLOSING;
 165 }
 166
 167 enum bus_auth {
 168         _BUS_AUTH_INVALID,
 169         BUS_AUTH_EXTERNAL,
 170         BUS_AUTH_ANONYMOUS
 171 };
 172
 173 struct sd_bus {
 174         /* We use atomic ref counting here since sd_bus_message
 175            objects retain references to their originating sd_bus but
 176            we want to allow them to be processed in a different
 177            thread. We won't provide full thread safety, but only the
 178            bare minimum that makes it possible to use sd_bus and
 179            sd_bus_message objects independently and on different
 180            threads as long as each object is used only once at the
 181            same time. */
 182         RefCount n_ref;
 183
 184         enum bus_state state;
 185         int input_fd, output_fd;
 186         int inotify_fd;
 187         int message_version;
 188         int message_endian;
 189
 190         bool can_fds:1;
 191         bool bus_client:1;
 192         bool ucred_valid:1;
 193         bool is_server:1;
 194         bool anonymous_auth:1;
 195         bool prefer_readv:1;
 196         bool prefer_writev:1;
 197         bool match_callbacks_modified:1;
 198         bool filter_callbacks_modified:1;
 199         bool nodes_modified:1;
 200         bool trusted:1;
 201         bool manual_peer_interface:1;
 202         bool is_system:1;
 203         bool is_user:1;
 204         bool allow_interactive_authorization:1;
 205         bool exit_on_disconnect:1;
 206         bool exited:1;
 207         bool exit_triggered:1;
 208         bool is_local:1;
 209         bool watch_bind:1;
 210         bool is_monitor:1;
 211         bool accept_fd:1;
 212         bool attach_timestamp:1;
 213         bool connected_signal:1;
 214         bool close_on_exit:1;
 215
 216         int use_memfd;
 217
 218         void *rbuffer;
 219         size_t rbuffer_size;
 220
 221         sd_bus_message **rqueue;
 222         unsigned rqueue_size;
 223         size_t rqueue_allocated;
 224
 225         sd_bus_message **wqueue;
 226         unsigned wqueue_size;
 227         size_t windex;
 228         size_t wqueue_allocated;
 229
 230         uint64_t cookie;
 231
 232         char *unique_name;
 233         uint64_t unique_id;
 234
 235         struct bus_match_node match_callbacks;
 236         Prioq *reply_callbacks_prioq;
 237         OrderedHashmap *reply_callbacks;
 238         LIST_HEAD(struct filter_callback, filter_callbacks);
 239
 240         Hashmap *nodes;
 241         Hashmap *vtable_methods;
 242         Hashmap *vtable_properties;
 243
 244         union sockaddr_union sockaddr;
 245         socklen_t sockaddr_size;
 246
 247         char *machine;
 248         pid_t nspid;
 249
 250         sd_id128_t server_id;
 251
 252         char *address;
 253         unsigned address_index;
 254
 255         int last_connect_error;
 256
 257         enum bus_auth auth;
 258         size_t auth_rbegin;
 259         struct iovec auth_iovec[3];
 260         unsigned auth_index;
 261         char *auth_buffer;
 262         usec_t auth_timeout;
 263
 264         struct ucred ucred;
 265         char *label;
 266         gid_t *groups;
 267         size_t n_groups;
 268
 269         uint64_t creds_mask;
 270
 271         int *fds;
 272         size_t n_fds;
 273
 274         char *exec_path;
 275         char **exec_argv;
 276
 277         unsigned iteration_counter;
 278
 279         /* We do locking around the memfd cache, since we want to
 280          * allow people to process a sd_bus_message in a different
 281          * thread then it was generated on and free it there. Since
 282          * adding something to the memfd cache might happen when a
 283          * message is released, we hence need to protect this bit with
 284          * a mutex. */
 285         pthread_mutex_t memfd_cache_mutex;
 286         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 287         unsigned n_memfd_cache;
 288
 289         pid_t original_pid;
 290         pid_t busexec_pid;
 291
 292         sd_event_source *input_io_event_source;
 293         sd_event_source *output_io_event_source;
 294         sd_event_source *time_event_source;
 295         sd_event_source *quit_event_source;
 296         sd_event_source *inotify_event_source;
 297         sd_event *event;
 298         int event_priority;
 299
 300         sd_bus_message *current_message;
 301         sd_bus_slot *current_slot;
 302         sd_bus_message_handler_t current_handler;
 303         void *current_userdata;
 304
 305         sd_bus **default_bus_ptr;
 306         pid_t tid;
 307
 308         char *cgroup_root;
 309
 310         char *description;
 311         char *patch_sender;
 312
 313         sd_bus_track *track_queue;
 314
 315         LIST_HEAD(sd_bus_slot, slots);
 316         LIST_HEAD(sd_bus_track, tracks);
 317
 318         int *inotify_watches;
 319         size_t n_inotify_watches;
 320
 321         /* zero means use value specified by $SYSTEMD_BUS_TIMEOUT= environment variable or built-in default */
 322         usec_t method_call_timeout;
 323 };
 324
 325 /* For method calls we time-out at 25s, like in the D-Bus reference implementation */
 326 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 327
 328 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 329  * with enough entropy yet and might delay the boot */
 330 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 331
 332 #define BUS_WQUEUE_MAX (192*1024)
 333 #define BUS_RQUEUE_MAX (192*1024)
 334
 335 #define BUS_MESSAGE_SIZE_MAX (128*1024*1024)
 336 #define BUS_AUTH_SIZE_MAX (64*1024)
 337
 338 #define BUS_CONTAINER_DEPTH 128
 339
 340 /* Defined by the specification as maximum size of an array in 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), true);       \
 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 on */
 392 #define BUS_DONT_DESTROY(bus) \
 393         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 394
 395 int bus_set_address_system(sd_bus *bus);
 396 int bus_set_address_user(sd_bus *bus);
 397 int bus_set_address_system_remote(sd_bus *b, const char *host);
 398 int bus_set_address_system_machine(sd_bus *b, const char *machine);
 399
 400 int bus_get_root_path(sd_bus *bus);
 401
 402 int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 403
 404 #define bus_assert_return(expr, r, error)                               \
 405         do {                                                            \
 406                 if (!assert_log(expr, #expr))                           \
 407                         return sd_bus_error_set_errno(error, r);        \
 408         } while (false)
 409
 410 void bus_enter_closing(sd_bus *bus);
 411
 412 void bus_set_state(sd_bus *bus, enum bus_state state);