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 "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         char *match_string;
  48
  49         struct bus_match_node *match_node;
  50 };
  51
  52 struct node {
  53         char *path;
  54         struct node *parent;
  55         LIST_HEAD(struct node, child);
  56         LIST_FIELDS(struct node, siblings);
  57
  58         LIST_HEAD(struct node_callback, callbacks);
  59         LIST_HEAD(struct node_vtable, vtables);
  60         LIST_HEAD(struct node_enumerator, enumerators);
  61         LIST_HEAD(struct node_object_manager, object_managers);
  62 };
  63
  64 struct node_callback {
  65         struct node *node;
  66
  67         bool is_fallback:1;
  68         unsigned last_iteration;
  69
  70         sd_bus_message_handler_t callback;
  71
  72         LIST_FIELDS(struct node_callback, callbacks);
  73 };
  74
  75 struct node_enumerator {
  76         struct node *node;
  77
  78         sd_bus_node_enumerator_t callback;
  79
  80         unsigned last_iteration;
  81
  82         LIST_FIELDS(struct node_enumerator, enumerators);
  83 };
  84
  85 struct node_object_manager {
  86         struct node *node;
  87
  88         LIST_FIELDS(struct node_object_manager, object_managers);
  89 };
  90
  91 struct node_vtable {
  92         struct node *node;
  93
  94         bool is_fallback:1;
  95         unsigned last_iteration;
  96
  97         char *interface;
  98         const sd_bus_vtable *vtable;
  99         sd_bus_object_find_t find;
 100
 101         LIST_FIELDS(struct node_vtable, vtables);
 102 };
 103
 104 struct vtable_member {
 105         const char *path;
 106         const char *interface;
 107         const char *member;
 108         struct node_vtable *parent;
 109         unsigned last_iteration;
 110         const sd_bus_vtable *vtable;
 111 };
 112
 113 typedef enum BusSlotType {
 114         BUS_REPLY_CALLBACK,
 115         BUS_FILTER_CALLBACK,
 116         BUS_MATCH_CALLBACK,
 117         BUS_NODE_CALLBACK,
 118         BUS_NODE_ENUMERATOR,
 119         BUS_NODE_VTABLE,
 120         BUS_NODE_OBJECT_MANAGER,
 121         _BUS_SLOT_INVALID = -1,
 122 } BusSlotType;
 123
 124 struct sd_bus_slot {
 125         unsigned n_ref;
 126         BusSlotType type:5;
 127
 128         /* Slots can be "floating" or not. If they are not floating (the usual case) then they reference the bus object
 129          * they are associated with. This means the bus object stays allocated at least as long as there is a slot
 130          * around associated with it. If it is floating, then the slot's lifecycle is bound to the lifecycle of the
 131          * bus: it will be disconnected from the bus when the bus is destroyed, and it keeping the slot reffed hence
 132          * won't mean the bus stays reffed too. Internally this means the reference direction is reversed: floating
 133          * slots objects are referenced by the bus object, and not vice versa. */
 134         bool floating:1;
 135
 136         bool match_added:1;
 137
 138         sd_bus *bus;
 139         void *userdata;
 140         sd_bus_destroy_t destroy_callback;
 141
 142         char *description;
 143
 144         LIST_FIELDS(sd_bus_slot, slots);
 145
 146         union {
 147                 struct reply_callback reply_callback;
 148                 struct filter_callback filter_callback;
 149                 struct match_callback match_callback;
 150                 struct node_callback node_callback;
 151                 struct node_enumerator node_enumerator;
 152                 struct node_object_manager node_object_manager;
 153                 struct node_vtable node_vtable;
 154         };
 155 };
 156
 157 enum bus_state {
 158         BUS_UNSET,
 159         BUS_WATCH_BIND,      /* waiting for the socket to appear via inotify */
 160         BUS_OPENING,         /* the kernel's connect() is still not ready */
 161         BUS_AUTHENTICATING,  /* we are currently in the "SASL" authorization phase of dbus */
 162         BUS_HELLO,           /* we are waiting for the Hello() response */
 163         BUS_RUNNING,
 164         BUS_CLOSING,
 165         BUS_CLOSED,
 166         _BUS_STATE_MAX,
 167 };
 168
 169 static inline bool BUS_IS_OPEN(enum bus_state state) {
 170         return state > BUS_UNSET && state < BUS_CLOSING;
 171 }
 172
 173 enum bus_auth {
 174         _BUS_AUTH_INVALID,
 175         BUS_AUTH_EXTERNAL,
 176         BUS_AUTH_ANONYMOUS
 177 };
 178
 179 struct sd_bus {
 180         unsigned n_ref;
 181
 182         enum bus_state state;
 183         int input_fd, output_fd;
 184         int inotify_fd;
 185         int message_version;
 186         int message_endian;
 187
 188         bool can_fds:1;
 189         bool bus_client:1;
 190         bool ucred_valid:1;
 191         bool is_server:1;
 192         bool anonymous_auth:1;
 193         bool prefer_readv:1;
 194         bool prefer_writev:1;
 195         bool match_callbacks_modified:1;
 196         bool filter_callbacks_modified:1;
 197         bool nodes_modified:1;
 198         bool trusted:1;
 199         bool manual_peer_interface:1;
 200         bool is_system:1;
 201         bool is_user:1;
 202         bool allow_interactive_authorization:1;
 203         bool exit_on_disconnect:1;
 204         bool exited:1;
 205         bool exit_triggered:1;
 206         bool is_local:1;
 207         bool watch_bind:1;
 208         bool is_monitor:1;
 209         bool accept_fd:1;
 210         bool attach_timestamp:1;
 211         bool connected_signal:1;
 212         bool close_on_exit:1;
 213
 214         int use_memfd:2;
 215
 216         void *rbuffer;
 217         size_t rbuffer_size;
 218
 219         sd_bus_message **rqueue;
 220         size_t rqueue_size;
 221         size_t rqueue_allocated;
 222
 223         sd_bus_message **wqueue;
 224         size_t wqueue_size;
 225         size_t windex;
 226         size_t wqueue_allocated;
 227
 228         uint64_t cookie;
 229
 230         char *unique_name;
 231         uint64_t unique_id;
 232
 233         struct bus_match_node match_callbacks;
 234         Prioq *reply_callbacks_prioq;
 235         OrderedHashmap *reply_callbacks;
 236         LIST_HEAD(struct filter_callback, filter_callbacks);
 237
 238         Hashmap *nodes;
 239         Hashmap *vtable_methods;
 240         Hashmap *vtable_properties;
 241
 242         union sockaddr_union sockaddr;
 243         socklen_t sockaddr_size;
 244
 245         pid_t nspid;
 246         char *machine;
 247
 248         sd_id128_t server_id;
 249
 250         char *address;
 251         unsigned address_index;
 252
 253         int last_connect_error;
 254
 255         enum bus_auth auth;
 256         unsigned auth_index;
 257         struct iovec auth_iovec[3];
 258         size_t auth_rbegin;
 259         char *auth_buffer;
 260         usec_t auth_timeout;
 261
 262         struct ucred ucred;
 263         char *label;
 264         gid_t *groups;
 265         size_t n_groups;
 266
 267         uint64_t creds_mask;
 268
 269         int *fds;
 270         size_t n_fds;
 271
 272         char *exec_path;
 273         char **exec_argv;
 274
 275         /* We do locking around the memfd cache, since we want to
 276          * allow people to process a sd_bus_message in a different
 277          * thread then it was generated on and free it there. Since
 278          * adding something to the memfd cache might happen when a
 279          * message is released, we hence need to protect this bit with
 280          * a mutex. */
 281         pthread_mutex_t memfd_cache_mutex;
 282         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 283         unsigned n_memfd_cache;
 284
 285         pid_t original_pid;
 286         pid_t busexec_pid;
 287
 288         unsigned iteration_counter;
 289
 290         sd_event_source *input_io_event_source;
 291         sd_event_source *output_io_event_source;
 292         sd_event_source *time_event_source;
 293         sd_event_source *quit_event_source;
 294         sd_event_source *inotify_event_source;
 295         sd_event *event;
 296         int event_priority;
 297
 298         pid_t tid;
 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
 307         char *description;
 308         char *patch_sender;
 309
 310         sd_bus_track *track_queue;
 311
 312         LIST_HEAD(sd_bus_slot, slots);
 313         LIST_HEAD(sd_bus_track, tracks);
 314
 315         int *inotify_watches;
 316         size_t n_inotify_watches;
 317
 318         /* zero means use value specified by $SYSTEMD_BUS_TIMEOUT= environment variable or built-in default */
 319         usec_t method_call_timeout;
 320 };
 321
 322 /* For method calls we timeout at 25s, like in the D-Bus reference implementation */
 323 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 324
 325 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 326  * with enough entropy yet and might delay the boot */
 327 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 328
 329 #define BUS_WQUEUE_MAX (192*1024)
 330 #define BUS_RQUEUE_MAX (192*1024)
 331
 332 #define BUS_MESSAGE_SIZE_MAX (128*1024*1024)
 333 #define BUS_AUTH_SIZE_MAX (64*1024)
 334 /* Note that the D-Bus specification states that bus paths shall have no size limit. We enforce here one
 335  * anyway, since truly unbounded strings are a security problem. The limit we pick is relatively large however,
 336  * to not clash unnecessarily with real-life applications. */
 337 #define BUS_PATH_SIZE_MAX (64*1024)
 338
 339 #define BUS_CONTAINER_DEPTH 128
 340
 341 /* Defined by the specification as maximum size of an array in bytes */
 342 #define BUS_ARRAY_MAX_SIZE 67108864
 343
 344 #define BUS_FDS_MAX 1024
 345
 346 #define BUS_EXEC_ARGV_MAX 256
 347
 348 bool interface_name_is_valid(const char *p) _pure_;
 349 bool service_name_is_valid(const char *p) _pure_;
 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_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 401
 402 #define bus_assert_return(expr, r, error)                               \
 403         do {                                                            \
 404                 if (!assert_log(expr, #expr))                           \
 405                         return sd_bus_error_set_errno(error, r);        \
 406         } while (false)
 407
 408 void bus_enter_closing(sd_bus *bus);
 409
 410 void bus_set_state(sd_bus *bus, enum bus_state state);