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_WATCH_BIND, /* waiting for the socket to appear via inotify */
 161         BUS_OPENING,
 162         BUS_AUTHENTICATING,
 163         BUS_HELLO,
 164         BUS_RUNNING,
 165         BUS_CLOSING,
 166         BUS_CLOSED
 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         /* We use atomic ref counting here since sd_bus_message
 181            objects retain references to their originating sd_bus but
 182            we want to allow them to be processed in a different
 183            thread. We won't provide full thread safety, but only the
 184            bare minimum that makes it possible to use sd_bus and
 185            sd_bus_message objects independently and on different
 186            threads as long as each object is used only once at the
 187            same time. */
 188         RefCount n_ref;
 189
 190         enum bus_state state;
 191         int input_fd, output_fd;
 192         int inotify_fd;
 193         int message_version;
 194         int message_endian;
 195
 196         bool can_fds:1;
 197         bool bus_client:1;
 198         bool ucred_valid:1;
 199         bool is_server:1;
 200         bool anonymous_auth:1;
 201         bool prefer_readv:1;
 202         bool prefer_writev:1;
 203         bool match_callbacks_modified:1;
 204         bool filter_callbacks_modified:1;
 205         bool nodes_modified:1;
 206         bool trusted:1;
 207         bool manual_peer_interface:1;
 208         bool is_system:1;
 209         bool is_user:1;
 210         bool allow_interactive_authorization:1;
 211         bool exit_on_disconnect:1;
 212         bool exited:1;
 213         bool exit_triggered:1;
 214         bool is_local:1;
 215         bool watch_bind:1;
 216
 217         int use_memfd;
 218
 219         void *rbuffer;
 220         size_t rbuffer_size;
 221
 222         sd_bus_message **rqueue;
 223         unsigned rqueue_size;
 224         size_t rqueue_allocated;
 225
 226         sd_bus_message **wqueue;
 227         unsigned wqueue_size;
 228         size_t windex;
 229         size_t wqueue_allocated;
 230
 231         uint64_t cookie;
 232
 233         char *unique_name;
 234         uint64_t unique_id;
 235
 236         struct bus_match_node match_callbacks;
 237         Prioq *reply_callbacks_prioq;
 238         OrderedHashmap *reply_callbacks;
 239         LIST_HEAD(struct filter_callback, filter_callbacks);
 240
 241         Hashmap *nodes;
 242         Hashmap *vtable_methods;
 243         Hashmap *vtable_properties;
 244
 245         union sockaddr_union sockaddr;
 246         socklen_t sockaddr_size;
 247
 248         char *machine;
 249         pid_t nspid;
 250
 251         sd_id128_t server_id;
 252
 253         char *address;
 254         unsigned address_index;
 255
 256         int last_connect_error;
 257
 258         enum bus_auth auth;
 259         size_t auth_rbegin;
 260         struct iovec auth_iovec[3];
 261         unsigned auth_index;
 262         char *auth_buffer;
 263         usec_t auth_timeout;
 264
 265         struct ucred ucred;
 266         char *label;
 267         gid_t *groups;
 268         size_t n_groups;
 269
 270         uint64_t creds_mask;
 271
 272         int *fds;
 273         unsigned n_fds;
 274
 275         char *exec_path;
 276         char **exec_argv;
 277
 278         unsigned iteration_counter;
 279
 280         /* We do locking around the memfd cache, since we want to
 281          * allow people to process a sd_bus_message in a different
 282          * thread then it was generated on and free it there. Since
 283          * adding something to the memfd cache might happen when a
 284          * message is released, we hence need to protect this bit with
 285          * a mutex. */
 286         pthread_mutex_t memfd_cache_mutex;
 287         struct memfd_cache memfd_cache[MEMFD_CACHE_MAX];
 288         unsigned n_memfd_cache;
 289
 290         pid_t original_pid;
 291
 292         uint64_t hello_flags;
 293         uint64_t attach_flags;
 294
 295         sd_event_source *input_io_event_source;
 296         sd_event_source *output_io_event_source;
 297         sd_event_source *time_event_source;
 298         sd_event_source *quit_event_source;
 299         sd_event_source *inotify_event_source;
 300         sd_event *event;
 301         int event_priority;
 302
 303         sd_bus_message *current_message;
 304         sd_bus_slot *current_slot;
 305         sd_bus_message_handler_t current_handler;
 306         void *current_userdata;
 307
 308         sd_bus **default_bus_ptr;
 309         pid_t tid;
 310
 311         char *cgroup_root;
 312
 313         char *description;
 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 (64*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 int bus_ensure_running(sd_bus *bus);
 366 int bus_start_running(sd_bus *bus);
 367 int bus_next_address(sd_bus *bus);
 368
 369 int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m);
 370
 371 int bus_rqueue_make_room(sd_bus *bus);
 372
 373 bool bus_pid_changed(sd_bus *bus);
 374
 375 char *bus_address_escape(const char *v);
 376
 377 int bus_attach_io_events(sd_bus *b);
 378 int bus_attach_inotify_event(sd_bus *b);
 379
 380 void bus_close_inotify_fd(sd_bus *b);
 381 void bus_close_io_fds(sd_bus *b);
 382
 383 #define OBJECT_PATH_FOREACH_PREFIX(prefix, path)                        \
 384         for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
 385              _slash && !(_slash[(_slash) == (prefix)] = 0);             \
 386              _slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
 387
 388 /* If we are invoking callbacks of a bus object, ensure unreffing the
 389  * bus from the callback doesn't destroy the object we are working
 390  * on */
 391 #define BUS_DONT_DESTROY(bus) \
 392         _cleanup_(sd_bus_unrefp) _unused_ sd_bus *_dont_destroy_##bus = sd_bus_ref(bus)
 393
 394 int bus_set_address_system(sd_bus *bus);
 395 int bus_set_address_user(sd_bus *bus);
 396 int bus_set_address_system_remote(sd_bus *b, const char *host);
 397 int bus_set_address_system_machine(sd_bus *b, const char *machine);
 398
 399 int bus_remove_match_by_string(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata);
 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 /**
 412  * enum kdbus_attach_flags - flags for metadata attachments
 413  * @KDBUS_ATTACH_TIMESTAMP:             Timestamp
 414  * @KDBUS_ATTACH_CREDS:                 Credentials
 415  * @KDBUS_ATTACH_PIDS:                  PIDs
 416  * @KDBUS_ATTACH_AUXGROUPS:             Auxiliary groups
 417  * @KDBUS_ATTACH_NAMES:                 Well-known names
 418  * @KDBUS_ATTACH_TID_COMM:              The "comm" process identifier of the TID
 419  * @KDBUS_ATTACH_PID_COMM:              The "comm" process identifier of the PID
 420  * @KDBUS_ATTACH_EXE:                   The path of the executable
 421  * @KDBUS_ATTACH_CMDLINE:               The process command line
 422  * @KDBUS_ATTACH_CGROUP:                The croup membership
 423  * @KDBUS_ATTACH_CAPS:                  The process capabilities
 424  * @KDBUS_ATTACH_SECLABEL:              The security label
 425  * @KDBUS_ATTACH_AUDIT:                 The audit IDs
 426  * @KDBUS_ATTACH_CONN_DESCRIPTION:      The human-readable connection name
 427  * @_KDBUS_ATTACH_ALL:                  All of the above
 428  * @_KDBUS_ATTACH_ANY:                  Wildcard match to enable any kind of
 429  *                                      metatdata.
 430  */
 431 enum kdbus_attach_flags {
 432         KDBUS_ATTACH_TIMESTAMP          =  1ULL <<  0,
 433         KDBUS_ATTACH_CREDS              =  1ULL <<  1,
 434         KDBUS_ATTACH_PIDS               =  1ULL <<  2,
 435         KDBUS_ATTACH_AUXGROUPS          =  1ULL <<  3,
 436         KDBUS_ATTACH_NAMES              =  1ULL <<  4,
 437         KDBUS_ATTACH_TID_COMM           =  1ULL <<  5,
 438         KDBUS_ATTACH_PID_COMM           =  1ULL <<  6,
 439         KDBUS_ATTACH_EXE                =  1ULL <<  7,
 440         KDBUS_ATTACH_CMDLINE            =  1ULL <<  8,
 441         KDBUS_ATTACH_CGROUP             =  1ULL <<  9,
 442         KDBUS_ATTACH_CAPS               =  1ULL << 10,
 443         KDBUS_ATTACH_SECLABEL           =  1ULL << 11,
 444         KDBUS_ATTACH_AUDIT              =  1ULL << 12,
 445         KDBUS_ATTACH_CONN_DESCRIPTION   =  1ULL << 13,
 446         _KDBUS_ATTACH_ALL               =  (1ULL << 14) - 1,
 447         _KDBUS_ATTACH_ANY               =  ~0ULL
 448 };
 449
 450 /**
 451  * enum kdbus_hello_flags - flags for struct kdbus_cmd_hello
 452  * @KDBUS_HELLO_ACCEPT_FD:      The connection allows the reception of
 453  *                              any passed file descriptors
 454  * @KDBUS_HELLO_ACTIVATOR:      Special-purpose connection which registers
 455  *                              a well-know name for a process to be started
 456  *                              when traffic arrives
 457  * @KDBUS_HELLO_POLICY_HOLDER:  Special-purpose connection which registers
 458  *                              policy entries for a name. The provided name
 459  *                              is not activated and not registered with the
 460  *                              name database, it only allows unprivileged
 461  *                              connections to acquire a name, talk or discover
 462  *                              a service
 463  * @KDBUS_HELLO_MONITOR:        Special-purpose connection to monitor
 464  *                              bus traffic
 465  */
 466 enum kdbus_hello_flags {
 467         KDBUS_HELLO_ACCEPT_FD           =  1ULL <<  0,
 468         KDBUS_HELLO_ACTIVATOR           =  1ULL <<  1,
 469         KDBUS_HELLO_POLICY_HOLDER       =  1ULL <<  2,
 470         KDBUS_HELLO_MONITOR             =  1ULL <<  3,
 471 };