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

   1 #pragma once
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <pthread.h>
  23 #include <sys/socket.h>
  24
  25 #include "sd-bus.h"
  26
  27 #include "bus-error.h"
  28 #include "bus-kernel.h"
  29 #include "bus-match.h"
  30 #include "def.h"
  31 #include "hashmap.h"
  32 #include "list.h"
  33 #include "prioq.h"
  34 #include "refcnt.h"
  35 #include "socket-util.h"
  36 #include "util.h"
  37
  38 struct reply_callback {
  39         sd_bus_message_handler_t callback;
  40         usec_t timeout;
  41         uint64_t cookie;
  42         unsigned prioq_idx;
  43 };
  44
  45 struct filter_callback {
  46         sd_bus_message_handler_t callback;
  47
  48         unsigned last_iteration;
  49
  50         LIST_FIELDS(struct filter_callback, callbacks);
  51 };
  52
  53 struct match_callback {
  54         sd_bus_message_handler_t callback;
  55
  56         uint64_t cookie;
  57         unsigned last_iteration;
  58
  59         char *match_string;
  60
  61         struct bus_match_node *match_node;
  62 };
  63
  64 struct node {
  65         char *path;
  66         struct node *parent;
  67         LIST_HEAD(struct node, child);
  68         LIST_FIELDS(struct node, siblings);
  69
  70         LIST_HEAD(struct node_callback, callbacks);
  71         LIST_HEAD(struct node_vtable, vtables);
  72         LIST_HEAD(struct node_enumerator, enumerators);
  73         LIST_HEAD(struct node_object_manager, object_managers);
  74 };
  75
  76 struct node_callback {
  77         struct node *node;
  78
  79         bool is_fallback;
  80         sd_bus_message_handler_t callback;
  81
  82         unsigned last_iteration;
  83
  84         LIST_FIELDS(struct node_callback, callbacks);
  85 };
  86
  87 struct node_enumerator {
  88         struct node *node;
  89
  90         sd_bus_node_enumerator_t callback;
  91
  92         unsigned last_iteration;
  93
  94         LIST_FIELDS(struct node_enumerator, enumerators);
  95 };
  96
  97 struct node_object_manager {
  98         struct node *node;
  99
 100         LIST_FIELDS(struct node_object_manager, object_managers);
 101 };
 102
 103 struct node_vtable {
 104         struct node *node;
 105
 106         char *interface;
 107         bool is_fallback;
 108         const sd_bus_vtable *vtable;
 109         sd_bus_object_find_t find;
 110
 111         unsigned last_iteration;
 112
 113         LIST_FIELDS(struct node_vtable, vtables);
 114 };
 115
 116 struct vtable_member {
 117         const char *path;
 118         const char *interface;
 119         const char *member;
 120         struct node_vtable *parent;
 121         unsigned last_iteration;
 122         const sd_bus_vtable *vtable;
 123 };
 124
 125 typedef enum BusSlotType {
 126         BUS_REPLY_CALLBACK,
 127         BUS_FILTER_CALLBACK,
 128         BUS_MATCH_CALLBACK,
 129         BUS_NODE_CALLBACK,
 130         BUS_NODE_ENUMERATOR,
 131         BUS_NODE_VTABLE,
 132         BUS_NODE_OBJECT_MANAGER,
 133         _BUS_SLOT_INVALID = -1,
 134 } BusSlotType;
 135
 136 struct sd_bus_slot {
 137         unsigned n_ref;
 138         sd_bus *bus;
 139         void *userdata;
 140         BusSlotType type:5;
 141         bool floating:1;
 142         bool match_added:1;
 143         char *description;
 144
 145         LIST_FIELDS(sd_bus_slot, slots);
 146
 147         union {
 148                 struct reply_callback reply_callback;
 149                 struct filter_callback filter_callback;
 150                 struct match_callback match_callback;
 151                 struct node_callback node_callback;
 152                 struct node_enumerator node_enumerator;
 153                 struct node_object_manager node_object_manager;
 154                 struct node_vtable node_vtable;
 155         };
 156 };
 157
 158 enum bus_state {
 159         BUS_UNSET,
 160         BUS_OPENING,
 161         BUS_AUTHENTICATING,
 162         BUS_HELLO,
 163         BUS_RUNNING,
 164         BUS_CLOSING,
 165         BUS_CLOSED
 166 };
 167
 168 static inline bool BUS_IS_OPEN(enum bus_state state) {
 169         return state > BUS_UNSET && state < BUS_CLOSING;
 170 }
 171
 172 enum bus_auth {
 173         _BUS_AUTH_INVALID,
 174         BUS_AUTH_EXTERNAL,
 175         BUS_AUTH_ANONYMOUS
 176 };
 177
 178 struct sd_bus {
 179         /* We use atomic ref counting here since sd_bus_message
 180            objects retain references to their originating sd_bus but
 181            we want to allow them to be processed in a different
 182            thread. We won't provide full thread safety, but only the
 183            bare minimum that makes it possible to use sd_bus and
 184            sd_bus_message objects independently and on different
 185            threads as long as each object is used only once at the
 186            same time. */
 187         RefCount n_ref;
 188
 189         enum bus_state state;
 190         int input_fd, output_fd;
 191         int message_version;
 192         int message_endian;
 193
 194         bool can_fds:1;
 195         bool bus_client:1;
 196         bool ucred_valid:1;
 197         bool is_server:1;
 198         bool anonymous_auth:1;
 199         bool prefer_readv:1;
 200         bool prefer_writev:1;
 201         bool match_callbacks_modified:1;
 202         bool filter_callbacks_modified:1;
 203         bool nodes_modified:1;
 204         bool trusted:1;
 205         bool manual_peer_interface:1;
 206         bool is_system:1;
 207         bool is_user:1;
 208         bool allow_interactive_authorization:1;
 209         bool exit_on_disconnect:1;
 210         bool exited:1;
 211         bool exit_triggered:1;
 212         bool is_local:1;
 213
 214         int use_memfd;
 215
 216         void *rbuffer;
 217         size_t rbuffer_size;
 218
 219         sd_bus_message **rqueue;
 220         unsigned rqueue_size;
 221         size_t rqueue_allocated;
 222
 223         sd_bus_message **wqueue;
 224         unsigned 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         char *machine;
 246         pid_t nspid;
 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         size_t auth_rbegin;
 257         struct iovec auth_iovec[3];
 258         unsigned auth_index;
 259         char *auth_buffer;
 260         usec_t auth_timeout;
 261
 262         struct ucred ucred;
 263         char *label;
 264
 265         uint64_t creds_mask;
 266
 267         int *fds;
 268         unsigned n_fds;
 269
 270         char *exec_path;
 271         char **exec_argv;
 272
 273         unsigned iteration_counter;
 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
 287         uint64_t hello_flags;
 288         uint64_t attach_flags;
 289
 290         uint64_t match_cookie;
 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 *event;
 297         int event_priority;
 298
 299         sd_bus_message *current_message;
 300         sd_bus_slot *current_slot;
 301         sd_bus_message_handler_t current_handler;
 302         void *current_userdata;
 303
 304         sd_bus **default_bus_ptr;
 305         pid_t tid;
 306
 307         char *cgroup_root;
 308
 309         char *description;
 310
 311         size_t bloom_size;
 312         unsigned bloom_n_hash;
 313
 314         sd_bus_track *track_queue;
 315
 316         LIST_HEAD(sd_bus_slot, slots);
 317         LIST_HEAD(sd_bus_track, tracks);
 318 };
 319
 320 /* For method calls we time-out at 25s, like in the D-Bus reference implementation */
 321 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 322
 323 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 324  * with enough entropy yet and might delay the boot */
 325 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 326
 327 #define BUS_WQUEUE_MAX (192*1024)
 328 #define BUS_RQUEUE_MAX (192*1024)
 329
 330 #define BUS_MESSAGE_SIZE_MAX (64*1024*1024)
 331 #define BUS_AUTH_SIZE_MAX (64*1024)
 332
 333 #define BUS_CONTAINER_DEPTH 128
 334
 335 /* Defined by the specification as maximum size of an array in
 336  * bytes */
 337 #define BUS_ARRAY_MAX_SIZE 67108864
 338
 339 #define BUS_FDS_MAX 1024
 340
 341 #define BUS_EXEC_ARGV_MAX 256
 342
 343 bool interface_name_is_valid(const char *p) _pure_;
 344 bool service_name_is_valid(const char *p) _pure_;
 345 char* service_name_startswith(const char *a, const char *b);
 346 bool member_name_is_valid(const char *p) _pure_;
 347 bool object_path_is_valid(const char *p) _pure_;
 348 char *object_path_startswith(const char *a, const char *b) _pure_;
 349
 350 bool namespace_complex_pattern(const char *pattern, const char *value) _pure_;
 351 bool path_complex_pattern(const char *pattern, const char *value) _pure_;
 352
 353 bool namespace_simple_pattern(const char *pattern, const char *value) _pure_;
 354 bool path_simple_pattern(const char *pattern, const char *value) _pure_;
 355
 356 int bus_message_type_from_string(const char *s, uint8_t *u) _pure_;
 357 const char *bus_message_type_to_string(uint8_t u) _pure_;
 358
 359 #define error_name_is_valid interface_name_is_valid
 360
 361 int bus_ensure_running(sd_bus *bus);
 362 int bus_start_running(sd_bus *bus);
 363 int bus_next_address(sd_bus *bus);
 364
 365 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m);
 366
 367 int bus_rqueue_make_room(sd_bus *bus);
 368
 369 bool bus_pid_changed(sd_bus *bus);
 370
 371 char *bus_address_escape(const char *v);
 372
 373 #define OBJECT_PATH_FOREACH_PREFIX(prefix, path)                        \
 374         for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
 375              _slash && !(_slash[(_slash) == (prefix)] = 0);             \
 376              _slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
 377
 378 /* If we are invoking callbacks of a bus object, ensure unreffing the
 379  * bus from the callback doesn't destroy the object we are working
 380  * on */
 381 #define BUS_DONT_DESTROY(bus) \
 382         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 383
 384 int bus_set_address_system(sd_bus *bus);
 385 int bus_set_address_user(sd_bus *bus);
 386 int bus_set_address_system_remote(sd_bus *b, const char *host);
 387 int bus_set_address_system_machine(sd_bus *b, const char *machine);
 388
 389 int bus_remove_match_by_string(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata);
 390
 391 int bus_get_root_path(sd_bus *bus);
 392
 393 int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 394
 395 #define bus_assert_return(expr, r, error)                               \
 396         do {                                                            \
 397                 if (!assert_log(expr, #expr))                           \
 398                         return sd_bus_error_set_errno(error, r);        \
 399         } while (false)
 400
 401 /**
 402  * enum kdbus_attach_flags - flags for metadata attachments
 403  * @KDBUS_ATTACH_TIMESTAMP:             Timestamp
 404  * @KDBUS_ATTACH_CREDS:                 Credentials
 405  * @KDBUS_ATTACH_PIDS:                  PIDs
 406  * @KDBUS_ATTACH_AUXGROUPS:             Auxiliary groups
 407  * @KDBUS_ATTACH_NAMES:                 Well-known names
 408  * @KDBUS_ATTACH_TID_COMM:              The "comm" process identifier of the TID
 409  * @KDBUS_ATTACH_PID_COMM:              The "comm" process identifier of the PID
 410  * @KDBUS_ATTACH_EXE:                   The path of the executable
 411  * @KDBUS_ATTACH_CMDLINE:               The process command line
 412  * @KDBUS_ATTACH_CGROUP:                The croup membership
 413  * @KDBUS_ATTACH_CAPS:                  The process capabilities
 414  * @KDBUS_ATTACH_SECLABEL:              The security label
 415  * @KDBUS_ATTACH_AUDIT:                 The audit IDs
 416  * @KDBUS_ATTACH_CONN_DESCRIPTION:      The human-readable connection name
 417  * @_KDBUS_ATTACH_ALL:                  All of the above
 418  * @_KDBUS_ATTACH_ANY:                  Wildcard match to enable any kind of
 419  *                                      metatdata.
 420  */
 421 enum kdbus_attach_flags {
 422         KDBUS_ATTACH_TIMESTAMP          =  1ULL <<  0,
 423         KDBUS_ATTACH_CREDS              =  1ULL <<  1,
 424         KDBUS_ATTACH_PIDS               =  1ULL <<  2,
 425         KDBUS_ATTACH_AUXGROUPS          =  1ULL <<  3,
 426         KDBUS_ATTACH_NAMES              =  1ULL <<  4,
 427         KDBUS_ATTACH_TID_COMM           =  1ULL <<  5,
 428         KDBUS_ATTACH_PID_COMM           =  1ULL <<  6,
 429         KDBUS_ATTACH_EXE                =  1ULL <<  7,
 430         KDBUS_ATTACH_CMDLINE            =  1ULL <<  8,
 431         KDBUS_ATTACH_CGROUP             =  1ULL <<  9,
 432         KDBUS_ATTACH_CAPS               =  1ULL << 10,
 433         KDBUS_ATTACH_SECLABEL           =  1ULL << 11,
 434         KDBUS_ATTACH_AUDIT              =  1ULL << 12,
 435         KDBUS_ATTACH_CONN_DESCRIPTION   =  1ULL << 13,
 436         _KDBUS_ATTACH_ALL               =  (1ULL << 14) - 1,
 437         _KDBUS_ATTACH_ANY               =  ~0ULL
 438 };
 439
 440 /**
 441  * enum kdbus_hello_flags - flags for struct kdbus_cmd_hello
 442  * @KDBUS_HELLO_ACCEPT_FD:      The connection allows the reception of
 443  *                              any passed file descriptors
 444  * @KDBUS_HELLO_ACTIVATOR:      Special-purpose connection which registers
 445  *                              a well-know name for a process to be started
 446  *                              when traffic arrives
 447  * @KDBUS_HELLO_POLICY_HOLDER:  Special-purpose connection which registers
 448  *                              policy entries for a name. The provided name
 449  *                              is not activated and not registered with the
 450  *                              name database, it only allows unprivileged
 451  *                              connections to acquire a name, talk or discover
 452  *                              a service
 453  * @KDBUS_HELLO_MONITOR:        Special-purpose connection to monitor
 454  *                              bus traffic
 455  */
 456 enum kdbus_hello_flags {
 457         KDBUS_HELLO_ACCEPT_FD           =  1ULL <<  0,
 458         KDBUS_HELLO_ACTIVATOR           =  1ULL <<  1,
 459         KDBUS_HELLO_POLICY_HOLDER       =  1ULL <<  2,
 460         KDBUS_HELLO_MONITOR             =  1ULL <<  3,
 461 };