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