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

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2013 Lennart Poettering
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 #include <pthread.h>
  24 #include <sys/socket.h>
  25
  26 #include "sd-bus.h"
  27
  28 #include "bus-error.h"
  29 #include "bus-kernel.h"
  30 #include "bus-match.h"
  31 #include "def.h"
  32 #include "hashmap.h"
  33 #include "list.h"
  34 #include "prioq.h"
  35 #include "refcnt.h"
  36 #include "socket-util.h"
  37 #include "util.h"
  38
  39 struct reply_callback {
  40         sd_bus_message_handler_t callback;
  41         usec_t timeout;
  42         uint64_t cookie;
  43         unsigned prioq_idx;
  44 };
  45
  46 struct filter_callback {
  47         sd_bus_message_handler_t callback;
  48
  49         unsigned last_iteration;
  50
  51         LIST_FIELDS(struct filter_callback, callbacks);
  52 };
  53
  54 struct match_callback {
  55         sd_bus_message_handler_t callback;
  56
  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         gid_t *groups;
 265         size_t n_groups;
 266
 267         uint64_t creds_mask;
 268
 269         int *fds;
 270         unsigned n_fds;
 271
 272         char *exec_path;
 273         char **exec_argv;
 274
 275         unsigned iteration_counter;
 276
 277         /* We do locking around the memfd cache, since we want to
 278          * allow people to process a sd_bus_message in a different
 279          * thread then it was generated on and free it there. Since
 280          * adding something to the memfd cache might happen when a
 281          * message is released, we hence need to protect this bit with
 282          * a mutex. */
 283         pthread_mutex_t memfd_cache_mutex;
 284         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 285         unsigned n_memfd_cache;
 286
 287         pid_t original_pid;
 288
 289         uint64_t hello_flags;
 290         uint64_t attach_flags;
 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         sd_bus_track *track_queue;
 312
 313         LIST_HEAD(sd_bus_slot, slots);
 314         LIST_HEAD(sd_bus_track, tracks);
 315 };
 316
 317 /* For method calls we time-out at 25s, like in the D-Bus reference implementation */
 318 #define BUS_DEFAULT_TIMEOUT ((usec_t) (25 * USEC_PER_SEC))
 319
 320 /* For the authentication phase we grant 90s, to provide extra room during boot, when RNGs and such are not filled up
 321  * with enough entropy yet and might delay the boot */
 322 #define BUS_AUTH_TIMEOUT ((usec_t) DEFAULT_TIMEOUT_USEC)
 323
 324 #define BUS_WQUEUE_MAX (192*1024)
 325 #define BUS_RQUEUE_MAX (192*1024)
 326
 327 #define BUS_MESSAGE_SIZE_MAX (64*1024*1024)
 328 #define BUS_AUTH_SIZE_MAX (64*1024)
 329
 330 #define BUS_CONTAINER_DEPTH 128
 331
 332 /* Defined by the specification as maximum size of an array in
 333  * bytes */
 334 #define BUS_ARRAY_MAX_SIZE 67108864
 335
 336 #define BUS_FDS_MAX 1024
 337
 338 #define BUS_EXEC_ARGV_MAX 256
 339
 340 bool interface_name_is_valid(const char *p) _pure_;
 341 bool service_name_is_valid(const char *p) _pure_;
 342 char* service_name_startswith(const char *a, const char *b);
 343 bool member_name_is_valid(const char *p) _pure_;
 344 bool object_path_is_valid(const char *p) _pure_;
 345 char *object_path_startswith(const char *a, const char *b) _pure_;
 346
 347 bool namespace_complex_pattern(const char *pattern, const char *value) _pure_;
 348 bool path_complex_pattern(const char *pattern, const char *value) _pure_;
 349
 350 bool namespace_simple_pattern(const char *pattern, const char *value) _pure_;
 351 bool path_simple_pattern(const char *pattern, const char *value) _pure_;
 352
 353 int bus_message_type_from_string(const char *s, uint8_t *u) _pure_;
 354 const char *bus_message_type_to_string(uint8_t u) _pure_;
 355
 356 #define error_name_is_valid interface_name_is_valid
 357
 358 int bus_ensure_running(sd_bus *bus);
 359 int bus_start_running(sd_bus *bus);
 360 int bus_next_address(sd_bus *bus);
 361
 362 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m);
 363
 364 int bus_rqueue_make_room(sd_bus *bus);
 365
 366 bool bus_pid_changed(sd_bus *bus);
 367
 368 char *bus_address_escape(const char *v);
 369
 370 #define OBJECT_PATH_FOREACH_PREFIX(prefix, path)                        \
 371         for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
 372              _slash && !(_slash[(_slash) == (prefix)] = 0);             \
 373              _slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
 374
 375 /* If we are invoking callbacks of a bus object, ensure unreffing the
 376  * bus from the callback doesn't destroy the object we are working
 377  * on */
 378 #define BUS_DONT_DESTROY(bus) \
 379         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 380
 381 int bus_set_address_system(sd_bus *bus);
 382 int bus_set_address_user(sd_bus *bus);
 383 int bus_set_address_system_remote(sd_bus *b, const char *host);
 384 int bus_set_address_system_machine(sd_bus *b, const char *machine);
 385
 386 int bus_remove_match_by_string(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata);
 387
 388 int bus_get_root_path(sd_bus *bus);
 389
 390 int bus_maybe_reply_error(sd_bus_message *m, int r, sd_bus_error *error);
 391
 392 #define bus_assert_return(expr, r, error)                               \
 393         do {                                                            \
 394                 if (!assert_log(expr, #expr))                           \
 395                         return sd_bus_error_set_errno(error, r);        \
 396         } while (false)
 397
 398 /**
 399  * enum kdbus_attach_flags - flags for metadata attachments
 400  * @KDBUS_ATTACH_TIMESTAMP:             Timestamp
 401  * @KDBUS_ATTACH_CREDS:                 Credentials
 402  * @KDBUS_ATTACH_PIDS:                  PIDs
 403  * @KDBUS_ATTACH_AUXGROUPS:             Auxiliary groups
 404  * @KDBUS_ATTACH_NAMES:                 Well-known names
 405  * @KDBUS_ATTACH_TID_COMM:              The "comm" process identifier of the TID
 406  * @KDBUS_ATTACH_PID_COMM:              The "comm" process identifier of the PID
 407  * @KDBUS_ATTACH_EXE:                   The path of the executable
 408  * @KDBUS_ATTACH_CMDLINE:               The process command line
 409  * @KDBUS_ATTACH_CGROUP:                The croup membership
 410  * @KDBUS_ATTACH_CAPS:                  The process capabilities
 411  * @KDBUS_ATTACH_SECLABEL:              The security label
 412  * @KDBUS_ATTACH_AUDIT:                 The audit IDs
 413  * @KDBUS_ATTACH_CONN_DESCRIPTION:      The human-readable connection name
 414  * @_KDBUS_ATTACH_ALL:                  All of the above
 415  * @_KDBUS_ATTACH_ANY:                  Wildcard match to enable any kind of
 416  *                                      metatdata.
 417  */
 418 enum kdbus_attach_flags {
 419         KDBUS_ATTACH_TIMESTAMP          =  1ULL <<  0,
 420         KDBUS_ATTACH_CREDS              =  1ULL <<  1,
 421         KDBUS_ATTACH_PIDS               =  1ULL <<  2,
 422         KDBUS_ATTACH_AUXGROUPS          =  1ULL <<  3,
 423         KDBUS_ATTACH_NAMES              =  1ULL <<  4,
 424         KDBUS_ATTACH_TID_COMM           =  1ULL <<  5,
 425         KDBUS_ATTACH_PID_COMM           =  1ULL <<  6,
 426         KDBUS_ATTACH_EXE                =  1ULL <<  7,
 427         KDBUS_ATTACH_CMDLINE            =  1ULL <<  8,
 428         KDBUS_ATTACH_CGROUP             =  1ULL <<  9,
 429         KDBUS_ATTACH_CAPS               =  1ULL << 10,
 430         KDBUS_ATTACH_SECLABEL           =  1ULL << 11,
 431         KDBUS_ATTACH_AUDIT              =  1ULL << 12,
 432         KDBUS_ATTACH_CONN_DESCRIPTION   =  1ULL << 13,
 433         _KDBUS_ATTACH_ALL               =  (1ULL << 14) - 1,
 434         _KDBUS_ATTACH_ANY               =  ~0ULL
 435 };
 436
 437 /**
 438  * enum kdbus_hello_flags - flags for struct kdbus_cmd_hello
 439  * @KDBUS_HELLO_ACCEPT_FD:      The connection allows the reception of
 440  *                              any passed file descriptors
 441  * @KDBUS_HELLO_ACTIVATOR:      Special-purpose connection which registers
 442  *                              a well-know name for a process to be started
 443  *                              when traffic arrives
 444  * @KDBUS_HELLO_POLICY_HOLDER:  Special-purpose connection which registers
 445  *                              policy entries for a name. The provided name
 446  *                              is not activated and not registered with the
 447  *                              name database, it only allows unprivileged
 448  *                              connections to acquire a name, talk or discover
 449  *                              a service
 450  * @KDBUS_HELLO_MONITOR:        Special-purpose connection to monitor
 451  *                              bus traffic
 452  */
 453 enum kdbus_hello_flags {
 454         KDBUS_HELLO_ACCEPT_FD           =  1ULL <<  0,
 455         KDBUS_HELLO_ACTIVATOR           =  1ULL <<  1,
 456         KDBUS_HELLO_POLICY_HOLDER       =  1ULL <<  2,
 457         KDBUS_HELLO_MONITOR             =  1ULL <<  3,
 458 };