src/libsystemd-bus/kdbus.h

   1 /*
   2  * Copyright (C) 2013 Kay Sievers
   3  * Copyright (C) 2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
   4  * Copyright (C) 2013 Linux Foundation
   5  * Copyright (C) 2013 Lennart Poettering
   6  * Copyright (C) 2013 Daniel Mack <daniel@zonque.org>
   7  *
   8  * kdbus is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU Lesser General Public License as published by the
  10  * Free Software Foundation; either version 2.1 of the License, or (at
  11  * your option) any later version.
  12  */
  13
  14 #ifndef _KDBUS_H_
  15 #define _KDBUS_H_
  16
  17 #ifndef __KERNEL__
  18 #include <sys/ioctl.h>
  19 #include <sys/types.h>
  20 #include <linux/types.h>
  21 #endif
  22
  23 #define KDBUS_IOC_MAGIC                 0x95
  24 #define KDBUS_SRC_ID_KERNEL             (0)
  25 #define KDBUS_DST_ID_WELL_KNOWN_NAME    (0)
  26 #define KDBUS_MATCH_SRC_ID_ANY          (~0ULL)
  27 #define KDBUS_DST_ID_BROADCAST          (~0ULL)
  28
  29 /* Common first elements in a structure which are used to iterate over
  30  * a list of elements. */
  31 #define KDBUS_PART_HEADER \
  32         struct {                                                        \
  33                 __u64 size;                                             \
  34                 __u64 type;                                             \
  35         }
  36
  37 /* Message sent from kernel to userspace, when the owner or starter of
  38  * a well-known name changes */
  39 struct kdbus_manager_msg_name_change {
  40         __u64 old_id;
  41         __u64 new_id;
  42         __u64 flags;                    /* 0 or (possibly?) KDBUS_NAME_IN_QUEUE */
  43         char name[0];
  44 };
  45
  46 struct kdbus_manager_msg_id_change {
  47         __u64 id;
  48         __u64 flags;                    /* The kernel flags field from KDBUS_HELLO */
  49 };
  50
  51 struct kdbus_creds {
  52         __u64 uid;
  53         __u64 gid;
  54         __u64 pid;
  55         __u64 tid;
  56
  57         /* The starttime of the process PID. This is useful to detect
  58         PID overruns from the client side. i.e. if you use the PID to
  59         look something up in /proc/$PID/ you can afterwards check the
  60         starttime field of it to ensure you didn't run into a PID
  61         ovretun. */
  62         __u64 starttime;
  63 };
  64
  65 struct kdbus_audit {
  66         __u64 sessionid;
  67         __u64 loginuid;
  68 };
  69
  70 struct kdbus_timestamp {
  71         __u64 monotonic_ns;
  72         __u64 realtime_ns;
  73 };
  74
  75 struct kdbus_vec {
  76         __u64 size;
  77         union {
  78                 __u64 address;
  79                 __u64 offset;
  80         };
  81 };
  82
  83 struct kdbus_memfd {
  84         __u64 size;
  85         int fd;
  86 };
  87
  88 /* Message Item Types */
  89 enum {
  90         _KDBUS_MSG_NULL,
  91
  92         /* Filled in by userspace */
  93         KDBUS_MSG_PAYLOAD_VEC,          /* .data_vec, reference to memory area */
  94         KDBUS_MSG_PAYLOAD_OFF,          /* .data_vec, reference to memory area */
  95         KDBUS_MSG_PAYLOAD_MEMFD,        /* file descriptor of a special data file */
  96         KDBUS_MSG_FDS,                  /* .data_fds of file descriptors */
  97         KDBUS_MSG_BLOOM,                /* for broadcasts, carries bloom filter blob in .data */
  98         KDBUS_MSG_DST_NAME,             /* destination's well-known name, in .str */
  99         KDBUS_MSG_PRIORITY,             /* queue priority for message */
 100
 101         /* Filled in by kernelspace */
 102         KDBUS_MSG_SRC_NAMES     = 0x400,/* NUL separated string list with well-known names of source */
 103         KDBUS_MSG_TIMESTAMP,            /* .timestamp */
 104         KDBUS_MSG_SRC_CREDS,            /* .creds */
 105         KDBUS_MSG_SRC_PID_COMM,         /* optional, in .str */
 106         KDBUS_MSG_SRC_TID_COMM,         /* optional, in .str */
 107         KDBUS_MSG_SRC_EXE,              /* optional, in .str */
 108         KDBUS_MSG_SRC_CMDLINE,          /* optional, in .str (a chain of NUL str) */
 109         KDBUS_MSG_SRC_CGROUP,           /* optional, in .str */
 110         KDBUS_MSG_SRC_CAPS,             /* caps data blob, in .data */
 111         KDBUS_MSG_SRC_SECLABEL,         /* NUL terminated string, in .str */
 112         KDBUS_MSG_SRC_AUDIT,            /* .audit */
 113
 114         /* Special messages from kernel, consisting of one and only one of these data blocks */
 115         KDBUS_MSG_NAME_ADD      = 0x800,/* .name_change */
 116         KDBUS_MSG_NAME_REMOVE,          /* .name_change */
 117         KDBUS_MSG_NAME_CHANGE,          /* .name_change */
 118         KDBUS_MSG_ID_ADD,               /* .id_change */
 119         KDBUS_MSG_ID_REMOVE,            /* .id_change */
 120         KDBUS_MSG_REPLY_TIMEOUT,        /* empty, but .reply_cookie in .kdbus_msg is filled in */
 121         KDBUS_MSG_REPLY_DEAD,           /* dito */
 122 };
 123
 124 /**
 125  * struct  kdbus_item - chain of data blocks
 126  *
 127  * size: overall data record size
 128  * type: kdbus_item type of data
 129  */
 130 struct kdbus_item {
 131         KDBUS_PART_HEADER;
 132         union {
 133                 /* inline data */
 134                 __u8 data[0];
 135                 __u32 data32[0];
 136                 __u64 data64[0];
 137                 char str[0];
 138
 139                 /* connection */
 140                 __u64 id;
 141
 142                 /* data vector */
 143                 struct kdbus_vec vec;
 144
 145                 /* process credentials and properties*/
 146                 struct kdbus_creds creds;
 147                 struct kdbus_audit audit;
 148                 struct kdbus_timestamp timestamp;
 149
 150                 /* specific fields */
 151                 struct kdbus_memfd memfd;
 152                 int fds[0];
 153                 struct kdbus_manager_msg_name_change name_change;
 154                 struct kdbus_manager_msg_id_change id_change;
 155         };
 156 };
 157
 158 enum {
 159         KDBUS_MSG_FLAGS_EXPECT_REPLY    = 1 << 0,
 160         KDBUS_MSG_FLAGS_NO_AUTO_START   = 1 << 1,
 161 };
 162
 163 enum {
 164         KDBUS_PAYLOAD_KERNEL,
 165         KDBUS_PAYLOAD_DBUS1     = 0x4442757356657231ULL, /* 'DBusVer1' */
 166         KDBUS_PAYLOAD_GVARIANT  = 0x4756617269616e74ULL, /* 'GVariant' */
 167 };
 168
 169 /**
 170  * struct kdbus_msg
 171  *
 172  * set by userspace:
 173  * dst_id: destination id
 174  * flags: KDBUS_MSG_FLAGS_*
 175  * items: data records
 176  *
 177  * set by kernel:
 178  * src_id: who sent the message
 179  */
 180 struct kdbus_msg {
 181         __u64 size;
 182         __u64 flags;
 183         __u64 dst_id;                   /* connection, 0 == name in data, ~0 broadcast */
 184         __u64 src_id;                   /* connection, 0 == kernel */
 185         __u64 payload_type;             /* 'DBusVer1', 'GVariant', ... */
 186         __u64 cookie;                   /* userspace-supplied cookie */
 187         union {
 188                 __u64 cookie_reply;     /* cookie we reply to */
 189                 __u64 timeout_ns;       /* timespan to wait for reply */
 190         };
 191         struct kdbus_item items[0];
 192 };
 193
 194 enum {
 195         _KDBUS_POLICY_NULL,
 196         KDBUS_POLICY_NAME,
 197         KDBUS_POLICY_ACCESS,
 198 };
 199
 200 enum {
 201         _KDBUS_POLICY_ACCESS_NULL,
 202         KDBUS_POLICY_ACCESS_USER,
 203         KDBUS_POLICY_ACCESS_GROUP,
 204         KDBUS_POLICY_ACCESS_WORLD,
 205 };
 206
 207 enum {
 208         KDBUS_POLICY_RECV               = 1 <<  2,
 209         KDBUS_POLICY_SEND               = 1 <<  1,
 210         KDBUS_POLICY_OWN                = 1 <<  0,
 211 };
 212
 213 struct kdbus_policy_access {
 214         __u64 type;             /* USER, GROUP, WORLD */
 215         __u64 bits;             /* RECV, SEND, OWN */
 216         __u64 id;               /* uid, gid, 0 */
 217 };
 218
 219 //FIXME: convert access to access[]
 220 struct kdbus_policy {
 221         KDBUS_PART_HEADER;
 222         union {
 223                 char name[0];
 224                 struct kdbus_policy_access access;
 225         };
 226 };
 227
 228 /* A series of KDBUS_POLICY_NAME, plus one or more KDBUS_POLICY_ACCESS */
 229 struct kdbus_cmd_policy {
 230         __u64 size;
 231         struct kdbus_policy policies[0];
 232 };
 233
 234 /* Flags for struct kdbus_cmd_hello */
 235 enum {
 236         KDBUS_HELLO_STARTER             =  1 <<  0,
 237         KDBUS_HELLO_ACCEPT_FD           =  1 <<  1,
 238
 239         /* The following have an effect on directed messages only --
 240          * not for broadcasts */
 241         KDBUS_HELLO_ATTACH_COMM         =  1 << 10,
 242         KDBUS_HELLO_ATTACH_EXE          =  1 << 11,
 243         KDBUS_HELLO_ATTACH_CMDLINE      =  1 << 12,
 244         KDBUS_HELLO_ATTACH_CGROUP       =  1 << 13,
 245         KDBUS_HELLO_ATTACH_CAPS         =  1 << 14,
 246         KDBUS_HELLO_ATTACH_SECLABEL     =  1 << 15,
 247         KDBUS_HELLO_ATTACH_AUDIT        =  1 << 16,
 248 };
 249
 250 struct kdbus_cmd_hello {
 251         __u64 size;
 252
 253         /* userspace → kernel, kernel → userspace */
 254         __u64 conn_flags;       /* userspace specifies its
 255                                  * capabilities and more, kernel
 256                                  * returns its capabilites and
 257                                  * more. Kernel might refuse client's
 258                                  * capabilities by returning an error
 259                                  * from KDBUS_HELLO */
 260
 261         /* kernel → userspace */
 262         __u64 bus_flags;        /* this is .flags copied verbatim from
 263                                  * from original KDBUS_CMD_BUS_MAKE
 264                                  * ioctl. It's intended to be useful
 265                                  * to do negotiation of features of
 266                                  * the payload that is transfreted. */
 267         __u64 id;               /* id assigned to this connection */
 268         __u64 bloom_size;       /* The bloom filter size chosen by the
 269                                  * bus owner */
 270         __u64 pool_size;        /* maximum size of pool buffer */
 271         struct kdbus_item items[0];
 272 };
 273
 274 /* Flags for kdbus_cmd_{bus,ep,ns}_make */
 275 enum {
 276         KDBUS_MAKE_ACCESS_GROUP         = 1 <<  0,
 277         KDBUS_MAKE_ACCESS_WORLD         = 1 <<  1,
 278         KDBUS_MAKE_POLICY_OPEN          = 1 <<  2,
 279 };
 280
 281 /* Items to append to kdbus_cmd_{bus,ep,ns}_make */
 282 enum {
 283         _KDBUS_MAKE_NULL,
 284         KDBUS_MAKE_NAME,
 285         KDBUS_MAKE_CGROUP,      /* the cgroup hierarchy ID for which to attach
 286                                  * cgroup membership paths to messages.
 287                                  * FIXME: remove, use *the* hierarchy */
 288         KDBUS_MAKE_CRED,        /* allow translator services which connect
 289                                  * to the bus on behalf of somebody else,
 290                                  * allow specifiying the credentials of the
 291                                  * client to connect on behalf on. Needs
 292                                  * privileges */
 293 };
 294
 295 struct kdbus_cmd_bus_make {
 296         __u64 size;
 297         __u64 flags;            /* userspace → kernel, kernel → userspace
 298                                  * When creating a bus feature
 299                                  * kernel negotiation. */
 300         __u64 bus_flags;        /* userspace → kernel
 301                                  * When a bus is created this value is
 302                                  * copied verbatim into the bus
 303                                  * structure and returned from
 304                                  * KDBUS_CMD_HELLO, later */
 305         __u64 bloom_size;       /* size of the bloom filter for this bus */
 306         struct kdbus_item items[0];
 307 };
 308
 309 struct kdbus_cmd_ep_make {
 310         __u64 size;
 311         __u64 flags;            /* userspace → kernel, kernel → userspace
 312                                  * When creating an entry point
 313                                  * feature kernel negotiation done the
 314                                  * same way as for
 315                                  * KDBUS_CMD_BUS_MAKE. Unused for
 316                                  * now. */
 317         struct kdbus_item items[0];
 318 };
 319
 320 struct kdbus_cmd_ns_make {
 321         __u64 size;
 322         __u64 flags;            /* userspace → kernel, kernel → userspace
 323                                  * When creating an entry point
 324                                  * feature kernel negotiation done the
 325                                  * same way as for
 326                                  * KDBUS_CMD_BUS_MAKE. Unused for
 327                                  * now. */
 328         struct kdbus_item items[0];
 329 };
 330
 331 enum {
 332         /* userspace → kernel */
 333         KDBUS_NAME_REPLACE_EXISTING             = 1 <<  0,
 334         KDBUS_NAME_QUEUE                        = 1 <<  1,
 335         KDBUS_NAME_ALLOW_REPLACEMENT            = 1 <<  2,
 336
 337         /* kernel → userspace */
 338         KDBUS_NAME_IN_QUEUE                     = 1 << 16,
 339 };
 340
 341 /* We allow (de)regestration of names of other peers */
 342 struct kdbus_cmd_name {
 343         __u64 size;
 344         __u64 flags;
 345         __u64 id;
 346         __u64 conn_flags;
 347         char name[0];
 348 };
 349
 350 struct kdbus_cmd_names {
 351         __u64 size;
 352         struct kdbus_cmd_name names[0];
 353 };
 354
 355 enum {
 356         _KDBUS_NAME_INFO_ITEM_NULL,
 357         KDBUS_NAME_INFO_ITEM_NAME,      /* userspace → kernel */
 358         KDBUS_NAME_INFO_ITEM_SECLABEL,  /* kernel → userspace */
 359         KDBUS_NAME_INFO_ITEM_AUDIT,     /* kernel → userspace */
 360 };
 361
 362 struct kdbus_cmd_name_info {
 363         __u64 size;                     /* overall size of info */
 364         __u64 flags;
 365         __u64 id;                       /* either ID, or 0 and _ITEM_NAME follows */
 366         struct kdbus_creds creds;
 367         struct kdbus_item items[0];     /* list of item records */
 368 };
 369
 370 enum {
 371         _KDBUS_MATCH_NULL,
 372         KDBUS_MATCH_BLOOM,              /* Matches a mask blob against KDBUS_MSG_BLOOM */
 373         KDBUS_MATCH_SRC_NAME,           /* Matches a name string against KDBUS_MSG_SRC_NAMES */
 374         KDBUS_MATCH_NAME_ADD,           /* Matches a name string against KDBUS_MSG_NAME_ADD */
 375         KDBUS_MATCH_NAME_REMOVE,        /* Matches a name string against KDBUS_MSG_NAME_REMOVE */
 376         KDBUS_MATCH_NAME_CHANGE,        /* Matches a name string against KDBUS_MSG_NAME_CHANGE */
 377         KDBUS_MATCH_ID_ADD,             /* Matches an ID against KDBUS_MSG_ID_ADD */
 378         KDBUS_MATCH_ID_REMOVE,          /* Matches an ID against KDBUS_MSG_ID_REMOVE */
 379 };
 380
 381 struct kdbus_cmd_match {
 382         __u64 size;
 383         __u64 id;       /* We allow registration/deregestration of matches for other peers */
 384         __u64 cookie;   /* userspace supplied cookie; when removing; kernel deletes everything with same cookie */
 385         __u64 src_id;   /* ~0: any. other: exact unique match */
 386         struct kdbus_item items[0];
 387 };
 388
 389 struct kdbus_cmd_monitor {
 390         __u64 id;               /* We allow setting the monitor flag of other peers */
 391         unsigned int enable;    /* A boolean to enable/disable monitoring */
 392 };
 393
 394 /* FD states:
 395  * control nodes: unset
 396  *   bus owner  (via KDBUS_CMD_BUS_MAKE)
 397  *   ns owner   (via KDBUS_CMD_NS_MAKE)
 398  *
 399  * ep nodes: unset
 400  *   connected  (via KDBUS_CMD_HELLO)
 401  *   starter    (via KDBUS_CMD_HELLO with KDBUS_CMD_HELLO_STARTER)
 402  *   ep owner   (via KDBUS_CMD_EP_MAKE)
 403  */
 404 enum {
 405         /* kdbus control node commands: require unset state */
 406         KDBUS_CMD_BUS_MAKE =            _IOWR(KDBUS_IOC_MAGIC, 0x00, struct kdbus_cmd_bus_make),
 407         KDBUS_CMD_NS_MAKE =             _IOWR(KDBUS_IOC_MAGIC, 0x10, struct kdbus_cmd_ns_make),
 408
 409         /* kdbus ep node commands: require unset state */
 410         KDBUS_CMD_EP_MAKE =             _IOWR(KDBUS_IOC_MAGIC, 0x20, struct kdbus_cmd_ep_make),
 411         KDBUS_CMD_HELLO =               _IOWR(KDBUS_IOC_MAGIC, 0x30, struct kdbus_cmd_hello),
 412
 413         /* kdbus ep node commands: require connected state */
 414         KDBUS_CMD_MSG_SEND =            _IOWR(KDBUS_IOC_MAGIC, 0x40, struct kdbus_msg),
 415         KDBUS_CMD_MSG_RECV =            _IOWR(KDBUS_IOC_MAGIC, 0x41, __u64 *),
 416         KDBUS_CMD_MSG_RELEASE =         _IOWR(KDBUS_IOC_MAGIC, 0x42, __u64 *),
 417
 418         KDBUS_CMD_NAME_ACQUIRE =        _IOWR(KDBUS_IOC_MAGIC, 0x50, struct kdbus_cmd_name),
 419         KDBUS_CMD_NAME_RELEASE =        _IOWR(KDBUS_IOC_MAGIC, 0x51, struct kdbus_cmd_name),
 420         KDBUS_CMD_NAME_LIST =           _IOWR(KDBUS_IOC_MAGIC, 0x52, struct kdbus_cmd_names),
 421         KDBUS_CMD_NAME_QUERY =          _IOWR(KDBUS_IOC_MAGIC, 0x53, struct kdbus_cmd_name_info),
 422
 423         KDBUS_CMD_MATCH_ADD =           _IOWR(KDBUS_IOC_MAGIC, 0x60, struct kdbus_cmd_match),
 424         KDBUS_CMD_MATCH_REMOVE =        _IOWR(KDBUS_IOC_MAGIC, 0x61, struct kdbus_cmd_match),
 425         KDBUS_CMD_MONITOR =             _IOWR(KDBUS_IOC_MAGIC, 0x62, struct kdbus_cmd_monitor),
 426
 427         /* kdbus ep node commands: require ep owner state */
 428         KDBUS_CMD_EP_POLICY_SET =       _IOWR(KDBUS_IOC_MAGIC, 0x70, struct kdbus_cmd_policy),
 429
 430         /* kdbus memfd commands: */
 431         KDBUS_CMD_MEMFD_NEW =           _IOWR(KDBUS_IOC_MAGIC, 0x80, int *),
 432         KDBUS_CMD_MEMFD_SIZE_GET =      _IOWR(KDBUS_IOC_MAGIC, 0x81, __u64 *),
 433         KDBUS_CMD_MEMFD_SIZE_SET =      _IOWR(KDBUS_IOC_MAGIC, 0x82, __u64 *),
 434         KDBUS_CMD_MEMFD_SEAL_GET =      _IOWR(KDBUS_IOC_MAGIC, 0x83, int *),
 435         KDBUS_CMD_MEMFD_SEAL_SET =      _IOWR(KDBUS_IOC_MAGIC, 0x84, int),
 436 };
 437 #endif