From: Daniel Mack Date: Thu, 11 Sep 2014 18:38:06 +0200 Subject: [PATCH] kdbus: add uapi header file This patch adds the header file which describes the low-level transport protocol used by various ioctls. The header file is located in include/uapi/linux/ as it is shared between kernel and userspace, and it only contains data structure definitions, enums and defines for constants. The low-level kernel API of kdbus is exposed through ioctls, employed on nodes exposed by kdbusfs. We've chosen a ioctl-based implementation over syscalls for various reaons: * The ioctls kdbus offers are completely specific to nodes exposed by kdbusfs and can not be applied to any other file descriptor in a system. * The file descriptors derived from opening nodes in kdbusfs can only be used for poll(), close() and the ioctls described in kdbus.h. * Not all systems will make use of kdbus eventually, and we want to make as many parts of the kernel optional at build time. * We want to build the kdbus code as module, which is impossible to do when implemented with syscalls. * The ioctl dispatching logic does not show up in our performance graphs; its overhead is negligible. * For development, being able to build, load and unload a separate module with a versioned name suffix is essential. Signed-off-by: Daniel Mack Signed-off-by: David Herrmann Signed-off-by: Djalal Harouni Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/Kbuild | 1 + include/uapi/linux/kdbus.h | 979 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 980 insertions(+) create mode 100644 include/uapi/linux/kdbus.h diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild index 1ff9942718fe..67a4c60e1deb 100644 --- a/include/uapi/linux/Kbuild +++ b/include/uapi/linux/Kbuild @@ -216,6 +216,7 @@ header-y += ixjuser.h header-y += jffs2.h header-y += joystick.h header-y += kcmp.h +header-y += kdbus.h header-y += kdev_t.h header-y += kd.h header-y += kernelcapi.h diff --git a/include/uapi/linux/kdbus.h b/include/uapi/linux/kdbus.h new file mode 100644 index 000000000000..fc1d77dd7c93 --- /dev/null +++ b/include/uapi/linux/kdbus.h @@ -0,0 +1,979 @@ +/* + * kdbus is free software; you can redistribute it and/or modify it under + * the terms of the GNU Lesser General Public License as published by the + * Free Software Foundation; either version 2.1 of the License, or (at + * your option) any later version. + */ + +#ifndef _KDBUS_UAPI_H_ +#define _KDBUS_UAPI_H_ + +#include +#include + +#define KDBUS_IOCTL_MAGIC 0x95 +#define KDBUS_SRC_ID_KERNEL (0) +#define KDBUS_DST_ID_NAME (0) +#define KDBUS_MATCH_ID_ANY (~0ULL) +#define KDBUS_DST_ID_BROADCAST (~0ULL) +#define KDBUS_FLAG_NEGOTIATE (1ULL << 63) + +/** + * struct kdbus_notify_id_change - name registry change message + * @id: New or former owner of the name + * @flags: flags field from KDBUS_HELLO_* + * + * Sent from kernel to userspace when the owner or activator of + * a well-known name changes. + * + * Attached to: + * KDBUS_ITEM_ID_ADD + * KDBUS_ITEM_ID_REMOVE + */ +struct kdbus_notify_id_change { + __u64 id; + __u64 flags; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_notify_name_change - name registry change message + * @old_id: ID and flags of former owner of a name + * @new_id: ID and flags of new owner of a name + * @name: Well-known name + * + * Sent from kernel to userspace when the owner or activator of + * a well-known name changes. + * + * Attached to: + * KDBUS_ITEM_NAME_ADD + * KDBUS_ITEM_NAME_REMOVE + * KDBUS_ITEM_NAME_CHANGE + */ +struct kdbus_notify_name_change { + struct kdbus_notify_id_change old_id; + struct kdbus_notify_id_change new_id; + char name[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_creds - process credentials + * @uid: User ID + * @euid: Effective UID + * @suid: Saved UID + * @fsuid: Filesystem UID + * @gid: Group ID + * @egid: Effective GID + * @sgid: Saved GID + * @fsgid: Filesystem GID + * + * Attached to: + * KDBUS_ITEM_CREDS + */ +struct kdbus_creds { + __u64 uid; + __u64 euid; + __u64 suid; + __u64 fsuid; + __u64 gid; + __u64 egid; + __u64 sgid; + __u64 fsgid; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_pids - process identifiers + * @pid: Process ID + * @tid: Thread ID + * @ppid: Parent process ID + * + * The PID and TID of a process. + * + * Attached to: + * KDBUS_ITEM_PIDS + */ +struct kdbus_pids { + __u64 pid; + __u64 tid; + __u64 ppid; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_caps - process capabilities + * @last_cap: Highest currently known capability bit + * @caps: Variable number of 32-bit capabilities flags + * + * Contains a variable number of 32-bit capabilities flags. + * + * Attached to: + * KDBUS_ITEM_CAPS + */ +struct kdbus_caps { + __u32 last_cap; + __u32 caps[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_audit - audit information + * @sessionid: The audit session ID + * @loginuid: The audit login uid + * + * Attached to: + * KDBUS_ITEM_AUDIT + */ +struct kdbus_audit { + __u32 sessionid; + __u32 loginuid; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_timestamp + * @seqnum: Global per-domain message sequence number + * @monotonic_ns: Monotonic timestamp, in nanoseconds + * @realtime_ns: Realtime timestamp, in nanoseconds + * + * Attached to: + * KDBUS_ITEM_TIMESTAMP + */ +struct kdbus_timestamp { + __u64 seqnum; + __u64 monotonic_ns; + __u64 realtime_ns; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_vec - I/O vector for kdbus payload items + * @size: The size of the vector + * @address: Memory address of data buffer + * @offset: Offset in the in-message payload memory, + * relative to the message head + * + * Attached to: + * KDBUS_ITEM_PAYLOAD_VEC, KDBUS_ITEM_PAYLOAD_OFF + */ +struct kdbus_vec { + __u64 size; + union { + __u64 address; + __u64 offset; + }; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_bloom_parameter - bus-wide bloom parameters + * @size: Size of the bit field in bytes (m / 8) + * @n_hash: Number of hash functions used (k) + */ +struct kdbus_bloom_parameter { + __u64 size; + __u64 n_hash; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_bloom_filter - bloom filter containing n elements + * @generation: Generation of the element set in the filter + * @data: Bit field, multiple of 8 bytes + */ +struct kdbus_bloom_filter { + __u64 generation; + __u64 data[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_memfd - a kdbus memfd + * @start: The offset into the memfd where the segment starts + * @size: The size of the memfd segment + * @fd: The file descriptor number + * @__pad: Padding to ensure proper alignment and size + * + * Attached to: + * KDBUS_ITEM_PAYLOAD_MEMFD + */ +struct kdbus_memfd { + __u64 start; + __u64 size; + int fd; + __u32 __pad; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_name - a registered well-known name with its flags + * @flags: Flags from KDBUS_NAME_* + * @name: Well-known name + * + * Attached to: + * KDBUS_ITEM_OWNED_NAME + */ +struct kdbus_name { + __u64 flags; + char name[0]; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_policy_access_type - permissions of a policy record + * @_KDBUS_POLICY_ACCESS_NULL: Uninitialized/invalid + * @KDBUS_POLICY_ACCESS_USER: Grant access to a uid + * @KDBUS_POLICY_ACCESS_GROUP: Grant access to gid + * @KDBUS_POLICY_ACCESS_WORLD: World-accessible + */ +enum kdbus_policy_access_type { + _KDBUS_POLICY_ACCESS_NULL, + KDBUS_POLICY_ACCESS_USER, + KDBUS_POLICY_ACCESS_GROUP, + KDBUS_POLICY_ACCESS_WORLD, +}; + +/** + * enum kdbus_policy_access_flags - mode flags + * @KDBUS_POLICY_OWN: Allow to own a well-known name + * Implies KDBUS_POLICY_TALK and KDBUS_POLICY_SEE + * @KDBUS_POLICY_TALK: Allow communication to a well-known name + * Implies KDBUS_POLICY_SEE + * @KDBUS_POLICY_SEE: Allow to see a well-known name + */ +enum kdbus_policy_type { + KDBUS_POLICY_SEE = 0, + KDBUS_POLICY_TALK, + KDBUS_POLICY_OWN, +}; + +/** + * struct kdbus_policy_access - policy access item + * @type: One of KDBUS_POLICY_ACCESS_* types + * @access: Access to grant + * @id: For KDBUS_POLICY_ACCESS_USER, the uid + * For KDBUS_POLICY_ACCESS_GROUP, the gid + */ +struct kdbus_policy_access { + __u64 type; /* USER, GROUP, WORLD */ + __u64 access; /* OWN, TALK, SEE */ + __u64 id; /* uid, gid, 0 */ +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_attach_flags - flags for metadata attachments + * @KDBUS_ATTACH_TIMESTAMP: Timestamp + * @KDBUS_ATTACH_CREDS: Credentials + * @KDBUS_ATTACH_PIDS: PIDs + * @KDBUS_ATTACH_AUXGROUPS: Auxiliary groups + * @KDBUS_ATTACH_NAMES: Well-known names + * @KDBUS_ATTACH_TID_COMM: The "comm" process identifier of the TID + * @KDBUS_ATTACH_PID_COMM: The "comm" process identifier of the PID + * @KDBUS_ATTACH_EXE: The path of the executable + * @KDBUS_ATTACH_CMDLINE: The process command line + * @KDBUS_ATTACH_CGROUP: The croup membership + * @KDBUS_ATTACH_CAPS: The process capabilities + * @KDBUS_ATTACH_SECLABEL: The security label + * @KDBUS_ATTACH_AUDIT: The audit IDs + * @KDBUS_ATTACH_CONN_DESCRIPTION: The human-readable connection name + * @_KDBUS_ATTACH_ALL: All of the above + * @_KDBUS_ATTACH_ANY: Wildcard match to enable any kind of + * metatdata. + */ +enum kdbus_attach_flags { + KDBUS_ATTACH_TIMESTAMP = 1ULL << 0, + KDBUS_ATTACH_CREDS = 1ULL << 1, + KDBUS_ATTACH_PIDS = 1ULL << 2, + KDBUS_ATTACH_AUXGROUPS = 1ULL << 3, + KDBUS_ATTACH_NAMES = 1ULL << 4, + KDBUS_ATTACH_TID_COMM = 1ULL << 5, + KDBUS_ATTACH_PID_COMM = 1ULL << 6, + KDBUS_ATTACH_EXE = 1ULL << 7, + KDBUS_ATTACH_CMDLINE = 1ULL << 8, + KDBUS_ATTACH_CGROUP = 1ULL << 9, + KDBUS_ATTACH_CAPS = 1ULL << 10, + KDBUS_ATTACH_SECLABEL = 1ULL << 11, + KDBUS_ATTACH_AUDIT = 1ULL << 12, + KDBUS_ATTACH_CONN_DESCRIPTION = 1ULL << 13, + _KDBUS_ATTACH_ALL = (1ULL << 14) - 1, + _KDBUS_ATTACH_ANY = ~0ULL +}; + +/** + * enum kdbus_item_type - item types to chain data in a list + * @_KDBUS_ITEM_NULL: Uninitialized/invalid + * @_KDBUS_ITEM_USER_BASE: Start of user items + * @KDBUS_ITEM_NEGOTIATE: Negotiate supported items + * @KDBUS_ITEM_PAYLOAD_VEC: Vector to data + * @KDBUS_ITEM_PAYLOAD_OFF: Data at returned offset to message head + * @KDBUS_ITEM_PAYLOAD_MEMFD: Data as sealed memfd + * @KDBUS_ITEM_FDS: Attached file descriptors + * @KDBUS_ITEM_CANCEL_FD: FD used to cancel a synchronous + * operation by writing to it from + * userspace + * @KDBUS_ITEM_BLOOM_PARAMETER: Bus-wide bloom parameters, used with + * KDBUS_CMD_BUS_MAKE, carries a + * struct kdbus_bloom_parameter + * @KDBUS_ITEM_BLOOM_FILTER: Bloom filter carried with a message, + * used to match against a bloom mask of a + * connection, carries a struct + * kdbus_bloom_filter + * @KDBUS_ITEM_BLOOM_MASK: Bloom mask used to match against a + * message'sbloom filter + * @KDBUS_ITEM_DST_NAME: Destination's well-known name + * @KDBUS_ITEM_MAKE_NAME: Name of domain, bus, endpoint + * @KDBUS_ITEM_ATTACH_FLAGS_SEND: Attach-flags, used for updating which + * metadata a connection opts in to send + * @KDBUS_ITEM_ATTACH_FLAGS_RECV: Attach-flags, used for updating which + * metadata a connection requests to + * receive for each reeceived message + * @KDBUS_ITEM_ID: Connection ID + * @KDBUS_ITEM_NAME: Well-know name with flags + * @_KDBUS_ITEM_ATTACH_BASE: Start of metadata attach items + * @KDBUS_ITEM_TIMESTAMP: Timestamp + * @KDBUS_ITEM_CREDS: Process credentials + * @KDBUS_ITEM_PIDS: Process identifiers + * @KDBUS_ITEM_AUXGROUPS: Auxiliary process groups + * @KDBUS_ITEM_OWNED_NAME: A name owned by the associated + * connection + * @KDBUS_ITEM_TID_COMM: Thread ID "comm" identifier + * (Don't trust this, see below.) + * @KDBUS_ITEM_PID_COMM: Process ID "comm" identifier + * (Don't trust this, see below.) + * @KDBUS_ITEM_EXE: The path of the executable + * (Don't trust this, see below.) + * @KDBUS_ITEM_CMDLINE: The process command line + * (Don't trust this, see below.) + * @KDBUS_ITEM_CGROUP: The croup membership + * @KDBUS_ITEM_CAPS: The process capabilities + * @KDBUS_ITEM_SECLABEL: The security label + * @KDBUS_ITEM_AUDIT: The audit IDs + * @KDBUS_ITEM_CONN_DESCRIPTION: The connection's human-readable name + * (debugging) + * @_KDBUS_ITEM_POLICY_BASE: Start of policy items + * @KDBUS_ITEM_POLICY_ACCESS: Policy access block + * @_KDBUS_ITEM_KERNEL_BASE: Start of kernel-generated message items + * @KDBUS_ITEM_NAME_ADD: Notification in kdbus_notify_name_change + * @KDBUS_ITEM_NAME_REMOVE: Notification in kdbus_notify_name_change + * @KDBUS_ITEM_NAME_CHANGE: Notification in kdbus_notify_name_change + * @KDBUS_ITEM_ID_ADD: Notification in kdbus_notify_id_change + * @KDBUS_ITEM_ID_REMOVE: Notification in kdbus_notify_id_change + * @KDBUS_ITEM_REPLY_TIMEOUT: Timeout has been reached + * @KDBUS_ITEM_REPLY_DEAD: Destination died + * + * N.B: The process and thread COMM fields, as well as the CMDLINE and + * EXE fields may be altered by unprivileged processes und should + * hence *not* used for security decisions. Peers should make use of + * these items only for informational purposes, such as generating log + * records. + */ +enum kdbus_item_type { + _KDBUS_ITEM_NULL, + _KDBUS_ITEM_USER_BASE, + KDBUS_ITEM_NEGOTIATE = _KDBUS_ITEM_USER_BASE, + KDBUS_ITEM_PAYLOAD_VEC, + KDBUS_ITEM_PAYLOAD_OFF, + KDBUS_ITEM_PAYLOAD_MEMFD, + KDBUS_ITEM_FDS, + KDBUS_ITEM_CANCEL_FD, + KDBUS_ITEM_BLOOM_PARAMETER, + KDBUS_ITEM_BLOOM_FILTER, + KDBUS_ITEM_BLOOM_MASK, + KDBUS_ITEM_DST_NAME, + KDBUS_ITEM_MAKE_NAME, + KDBUS_ITEM_ATTACH_FLAGS_SEND, + KDBUS_ITEM_ATTACH_FLAGS_RECV, + KDBUS_ITEM_ID, + KDBUS_ITEM_NAME, + + /* keep these item types in sync with KDBUS_ATTACH_* flags */ + _KDBUS_ITEM_ATTACH_BASE = 0x1000, + KDBUS_ITEM_TIMESTAMP = _KDBUS_ITEM_ATTACH_BASE, + KDBUS_ITEM_CREDS, + KDBUS_ITEM_PIDS, + KDBUS_ITEM_AUXGROUPS, + KDBUS_ITEM_OWNED_NAME, + KDBUS_ITEM_TID_COMM, + KDBUS_ITEM_PID_COMM, + KDBUS_ITEM_EXE, + KDBUS_ITEM_CMDLINE, + KDBUS_ITEM_CGROUP, + KDBUS_ITEM_CAPS, + KDBUS_ITEM_SECLABEL, + KDBUS_ITEM_AUDIT, + KDBUS_ITEM_CONN_DESCRIPTION, + + _KDBUS_ITEM_POLICY_BASE = 0x2000, + KDBUS_ITEM_POLICY_ACCESS = _KDBUS_ITEM_POLICY_BASE, + + _KDBUS_ITEM_KERNEL_BASE = 0x8000, + KDBUS_ITEM_NAME_ADD = _KDBUS_ITEM_KERNEL_BASE, + KDBUS_ITEM_NAME_REMOVE, + KDBUS_ITEM_NAME_CHANGE, + KDBUS_ITEM_ID_ADD, + KDBUS_ITEM_ID_REMOVE, + KDBUS_ITEM_REPLY_TIMEOUT, + KDBUS_ITEM_REPLY_DEAD, +}; + +/** + * struct kdbus_item - chain of data blocks + * @size: Overall data record size + * @type: Kdbus_item type of data + * @data: Generic bytes + * @data32: Generic 32 bit array + * @data64: Generic 64 bit array + * @str: Generic string + * @id: Connection ID + * @vec: KDBUS_ITEM_PAYLOAD_VEC + * @creds: KDBUS_ITEM_CREDS + * @audit: KDBUS_ITEM_AUDIT + * @timestamp: KDBUS_ITEM_TIMESTAMP + * @name: KDBUS_ITEM_NAME + * @bloom_parameter: KDBUS_ITEM_BLOOM_PARAMETER + * @bloom_filter: KDBUS_ITEM_BLOOM_FILTER + * @memfd: KDBUS_ITEM_PAYLOAD_MEMFD + * @name_change: KDBUS_ITEM_NAME_ADD + * KDBUS_ITEM_NAME_REMOVE + * KDBUS_ITEM_NAME_CHANGE + * @id_change: KDBUS_ITEM_ID_ADD + * KDBUS_ITEM_ID_REMOVE + * @policy: KDBUS_ITEM_POLICY_ACCESS + */ +struct kdbus_item { + __u64 size; + __u64 type; + union { + __u8 data[0]; + __u32 data32[0]; + __u64 data64[0]; + char str[0]; + + __u64 id; + struct kdbus_vec vec; + struct kdbus_creds creds; + struct kdbus_pids pids; + struct kdbus_audit audit; + struct kdbus_caps caps; + struct kdbus_timestamp timestamp; + struct kdbus_name name; + struct kdbus_bloom_parameter bloom_parameter; + struct kdbus_bloom_filter bloom_filter; + struct kdbus_memfd memfd; + int fds[0]; + struct kdbus_notify_name_change name_change; + struct kdbus_notify_id_change id_change; + struct kdbus_policy_access policy_access; + }; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_msg_flags - type of message + * @KDBUS_MSG_EXPECT_REPLY: Expect a reply message, used for + * method calls. The userspace-supplied + * cookie identifies the message and the + * respective reply carries the cookie + * in cookie_reply + * @KDBUS_MSG_NO_AUTO_START: Do not start a service if the addressed + * name is not currently active. This flag is + * not looked at by the kernel but only + * serves as hint for userspace implementations. + * @KDBUS_MSG_SIGNAL: Treat this message as signal + */ +enum kdbus_msg_flags { + KDBUS_MSG_EXPECT_REPLY = 1ULL << 0, + KDBUS_MSG_NO_AUTO_START = 1ULL << 1, + KDBUS_MSG_SIGNAL = 1ULL << 2, +}; + +/** + * enum kdbus_payload_type - type of payload carried by message + * @KDBUS_PAYLOAD_KERNEL: Kernel-generated simple message + * @KDBUS_PAYLOAD_DBUS: D-Bus marshalling "DBusDBus" + * + * Any payload-type is accepted. Common types will get added here once + * established. + */ +enum kdbus_payload_type { + KDBUS_PAYLOAD_KERNEL, + KDBUS_PAYLOAD_DBUS = 0x4442757344427573ULL, +}; + +/** + * struct kdbus_msg - the representation of a kdbus message + * @size: Total size of the message + * @flags: Message flags (KDBUS_MSG_*), userspace → kernel + * @priority: Message queue priority value + * @dst_id: 64-bit ID of the destination connection + * @src_id: 64-bit ID of the source connection + * @payload_type: Payload type (KDBUS_PAYLOAD_*) + * @cookie: Userspace-supplied cookie, for the connection + * to identify its messages + * @timeout_ns: The time to wait for a message reply from the peer. + * If there is no reply, and the send command is + * executed asynchronously, a kernel-generated message + * with an attached KDBUS_ITEM_REPLY_TIMEOUT item + * is sent to @src_id. For synchronously executed send + * command, the value denotes the maximum time the call + * blocks to wait for a reply. The timeout is expected in + * nanoseconds and as absolute CLOCK_MONOTONIC value. + * @cookie_reply: A reply to the requesting message with the same + * cookie. The requesting connection can match its + * request and the reply with this value + * @items: A list of kdbus_items containing the message payload + */ +struct kdbus_msg { + __u64 size; + __u64 flags; + __s64 priority; + __u64 dst_id; + __u64 src_id; + __u64 payload_type; + __u64 cookie; + union { + __u64 timeout_ns; + __u64 cookie_reply; + }; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_msg_info - returned message container + * @offset: Offset of kdbus_msg slice in pool + * @msg_size: Copy of the kdbus_msg.size field + * @return_flags: Command return flags, kernel → userspace + */ +struct kdbus_msg_info { + __u64 offset; + __u64 msg_size; + __u64 return_flags; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_send_flags - flags for sending messages + * @KDBUS_SEND_SYNC_REPLY: Wait for destination connection to + * reply to this message. The + * KDBUS_CMD_SEND ioctl() will block + * until the reply is received, and + * offset_reply in struct kdbus_msg will + * yield the offset in the sender's pool + * where the reply can be found. + * This flag is only valid if + * @KDBUS_MSG_EXPECT_REPLY is set as well. + */ +enum kdbus_send_flags { + KDBUS_SEND_SYNC_REPLY = 1ULL << 0, +}; + +/** + * struct kdbus_cmd_send - send message + * @size: Overall size of this structure + * @flags: Flags to change send behavior (KDBUS_SEND_*) + * @return_flags: Command return flags, kernel → userspace + * @msg_address: Storage address of the kdbus_msg to send + * @reply: Storage for message reply if KDBUS_SEND_SYNC_REPLY + * was given + * @items: Additional items for this command + */ +struct kdbus_cmd_send { + __u64 size; + __u64 flags; + __u64 return_flags; + __u64 msg_address; + struct kdbus_msg_info reply; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_recv_flags - flags for de-queuing messages + * @KDBUS_RECV_PEEK: Return the next queued message without + * actually de-queuing it, and without installing + * any file descriptors or other resources. It is + * usually used to determine the activating + * connection of a bus name. + * @KDBUS_RECV_DROP: Drop and free the next queued message and all + * its resources without actually receiving it. + * @KDBUS_RECV_USE_PRIORITY: Only de-queue messages with the specified or + * higher priority (lowest values); if not set, + * the priority value is ignored. + */ +enum kdbus_recv_flags { + KDBUS_RECV_PEEK = 1ULL << 0, + KDBUS_RECV_DROP = 1ULL << 1, + KDBUS_RECV_USE_PRIORITY = 1ULL << 2, +}; + +/** + * enum kdbus_recv_return_flags - return flags for message receive commands + * @KDBUS_RECV_RETURN_INCOMPLETE_FDS: One or more file descriptors could not + * be installed. These descriptors in + * KDBUS_ITEM_FDS will carry the value -1. + * @KDBUS_RECV_RETURN_DROPPED_MSGS: There have been dropped messages since + * the last time a message was received. + * The 'dropped_msgs' counter contains the + * number of messages dropped pool + * overflows or other missed broadcasts. + */ +enum kdbus_recv_return_flags { + KDBUS_RECV_RETURN_INCOMPLETE_FDS = 1ULL << 0, + KDBUS_RECV_RETURN_DROPPED_MSGS = 1ULL << 1, +}; + +/** + * struct kdbus_cmd_recv - struct to de-queue a buffered message + * @size: Overall size of this object + * @flags: KDBUS_RECV_* flags, userspace → kernel + * @return_flags: Command return flags, kernel → userspace + * @priority: Minimum priority of the messages to de-queue. Lowest + * values have the highest priority. + * @dropped_msgs: In case there were any dropped messages since the last + * time a message was received, this will be set to the + * number of lost messages and + * KDBUS_RECV_RETURN_DROPPED_MSGS will be set in + * 'return_flags'. This can only happen if the ioctl + * returns 0 or EAGAIN. + * @msg: Return storage for received message. + * @items: Additional items for this command. + * + * This struct is used with the KDBUS_CMD_RECV ioctl. + */ +struct kdbus_cmd_recv { + __u64 size; + __u64 flags; + __u64 return_flags; + __s64 priority; + __u64 dropped_msgs; + struct kdbus_msg_info msg; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_cmd_free - struct to free a slice of memory in the pool + * @size: Overall size of this structure + * @flags: Flags for the free command, userspace → kernel + * @return_flags: Command return flags, kernel → userspace + * @offset: The offset of the memory slice, as returned by other + * ioctls + * @items: Additional items to modify the behavior + * + * This struct is used with the KDBUS_CMD_FREE ioctl. + */ +struct kdbus_cmd_free { + __u64 size; + __u64 flags; + __u64 return_flags; + __u64 offset; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_hello_flags - flags for struct kdbus_cmd_hello + * @KDBUS_HELLO_ACCEPT_FD: The connection allows the reception of + * any passed file descriptors + * @KDBUS_HELLO_ACTIVATOR: Special-purpose connection which registers + * a well-know name for a process to be started + * when traffic arrives + * @KDBUS_HELLO_POLICY_HOLDER: Special-purpose connection which registers + * policy entries for a name. The provided name + * is not activated and not registered with the + * name database, it only allows unprivileged + * connections to acquire a name, talk or discover + * a service + * @KDBUS_HELLO_MONITOR: Special-purpose connection to monitor + * bus traffic + */ +enum kdbus_hello_flags { + KDBUS_HELLO_ACCEPT_FD = 1ULL << 0, + KDBUS_HELLO_ACTIVATOR = 1ULL << 1, + KDBUS_HELLO_POLICY_HOLDER = 1ULL << 2, + KDBUS_HELLO_MONITOR = 1ULL << 3, +}; + +/** + * struct kdbus_cmd_hello - struct to say hello to kdbus + * @size: The total size of the structure + * @flags: Connection flags (KDBUS_HELLO_*), userspace → kernel + * @return_flags: Command return flags, kernel → userspace + * @attach_flags_send: Mask of metadata to attach to each message sent + * off by this connection (KDBUS_ATTACH_*) + * @attach_flags_recv: Mask of metadata to attach to each message receieved + * by the new connection (KDBUS_ATTACH_*) + * @bus_flags: The flags field copied verbatim from the original + * KDBUS_CMD_BUS_MAKE ioctl. It's intended to be useful + * to do negotiation of features of the payload that is + * transferred (kernel → userspace) + * @id: The ID of this connection (kernel → userspace) + * @pool_size: Size of the connection's buffer where the received + * messages are placed + * @offset: Pool offset where items are returned to report + * additional information about the bus and the newly + * created connection. + * @items_size: Size of buffer returned in the pool slice at @offset. + * @id128: Unique 128-bit ID of the bus (kernel → userspace) + * @items: A list of items + * + * This struct is used with the KDBUS_CMD_HELLO ioctl. + */ +struct kdbus_cmd_hello { + __u64 size; + __u64 flags; + __u64 return_flags; + __u64 attach_flags_send; + __u64 attach_flags_recv; + __u64 bus_flags; + __u64 id; + __u64 pool_size; + __u64 offset; + __u64 items_size; + __u8 id128[16]; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_info - connection information + * @size: total size of the struct + * @id: 64bit object ID + * @flags: object creation flags + * @items: list of items + * + * Note that the user is responsible for freeing the allocated memory with + * the KDBUS_CMD_FREE ioctl. + */ +struct kdbus_info { + __u64 size; + __u64 id; + __u64 flags; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_list_flags - what to include into the returned list + * @KDBUS_LIST_UNIQUE: active connections + * @KDBUS_LIST_ACTIVATORS: activator connections + * @KDBUS_LIST_NAMES: known well-known names + * @KDBUS_LIST_QUEUED: queued-up names + */ +enum kdbus_list_flags { + KDBUS_LIST_UNIQUE = 1ULL << 0, + KDBUS_LIST_NAMES = 1ULL << 1, + KDBUS_LIST_ACTIVATORS = 1ULL << 2, + KDBUS_LIST_QUEUED = 1ULL << 3, +}; + +/** + * struct kdbus_cmd_list - list connections + * @size: overall size of this object + * @flags: flags for the query (KDBUS_LIST_*), userspace → kernel + * @return_flags: command return flags, kernel → userspace + * @offset: Offset in the caller's pool buffer where an array of + * kdbus_info objects is stored. + * The user must use KDBUS_CMD_FREE to free the + * allocated memory. + * @list_size: size of returned list in bytes + * @items: Items for the command. Reserved for future use. + * + * This structure is used with the KDBUS_CMD_LIST ioctl. + */ +struct kdbus_cmd_list { + __u64 size; + __u64 flags; + __u64 return_flags; + __u64 offset; + __u64 list_size; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * struct kdbus_cmd_info - struct used for KDBUS_CMD_CONN_INFO ioctl + * @size: The total size of the struct + * @flags: Flags for this ioctl, userspace → kernel + * @return_flags: Command return flags, kernel → userspace + * @id: The 64-bit ID of the connection. If set to zero, passing + * @name is required. kdbus will look up the name to + * determine the ID in this case. + * @attach_flags: Set of attach flags to specify the set of information + * to receive, userspace → kernel + * @offset: Returned offset in the caller's pool buffer where the + * kdbus_info struct result is stored. The user must + * use KDBUS_CMD_FREE to free the allocated memory. + * @info_size: Output buffer to report size of data at @offset. + * @items: The optional item list, containing the + * well-known name to look up as a KDBUS_ITEM_NAME. + * Only needed in case @id is zero. + * + * On success, the KDBUS_CMD_CONN_INFO ioctl will return 0 and @offset will + * tell the user the offset in the connection pool buffer at which to find the + * result in a struct kdbus_info. + */ +struct kdbus_cmd_info { + __u64 size; + __u64 flags; + __u64 return_flags; + __u64 id; + __u64 attach_flags; + __u64 offset; + __u64 info_size; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_cmd_match_flags - flags to control the KDBUS_CMD_MATCH_ADD ioctl + * @KDBUS_MATCH_REPLACE: If entries with the supplied cookie already + * exists, remove them before installing the new + * matches. + */ +enum kdbus_cmd_match_flags { + KDBUS_MATCH_REPLACE = 1ULL << 0, +}; + +/** + * struct kdbus_cmd_match - struct to add or remove matches + * @size: The total size of the struct + * @flags: Flags for match command (KDBUS_MATCH_*), + * userspace → kernel + * @return_flags: Command return flags, kernel → userspace + * @cookie: Userspace supplied cookie. When removing, the cookie + * identifies the match to remove + * @items: A list of items for additional information + * + * This structure is used with the KDBUS_CMD_MATCH_ADD and + * KDBUS_CMD_MATCH_REMOVE ioctl. + */ +struct kdbus_cmd_match { + __u64 size; + __u64 flags; + __u64 return_flags; + __u64 cookie; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * enum kdbus_make_flags - Flags for KDBUS_CMD_{BUS,ENDPOINT}_MAKE + * @KDBUS_MAKE_ACCESS_GROUP: Make the bus or endpoint node group-accessible + * @KDBUS_MAKE_ACCESS_WORLD: Make the bus or endpoint node world-accessible + */ +enum kdbus_make_flags { + KDBUS_MAKE_ACCESS_GROUP = 1ULL << 0, + KDBUS_MAKE_ACCESS_WORLD = 1ULL << 1, +}; + +/** + * enum kdbus_name_flags - flags for KDBUS_CMD_NAME_ACQUIRE + * @KDBUS_NAME_REPLACE_EXISTING: Try to replace name of other connections + * @KDBUS_NAME_ALLOW_REPLACEMENT: Allow the replacement of the name + * @KDBUS_NAME_QUEUE: Name should be queued if busy + * @KDBUS_NAME_IN_QUEUE: Name is queued + * @KDBUS_NAME_ACTIVATOR: Name is owned by a activator connection + */ +enum kdbus_name_flags { + KDBUS_NAME_REPLACE_EXISTING = 1ULL << 0, + KDBUS_NAME_ALLOW_REPLACEMENT = 1ULL << 1, + KDBUS_NAME_QUEUE = 1ULL << 2, + KDBUS_NAME_IN_QUEUE = 1ULL << 3, + KDBUS_NAME_ACTIVATOR = 1ULL << 4, +}; + +/** + * struct kdbus_cmd - generic ioctl payload + * @size: Overall size of this structure + * @flags: Flags for this ioctl, userspace → kernel + * @return_flags: Ioctl return flags, kernel → userspace + * @items: Additional items to modify the behavior + * + * This is a generic ioctl payload object. It's used by all ioctls that only + * take flags and items as input. + */ +struct kdbus_cmd { + __u64 size; + __u64 flags; + __u64 return_flags; + struct kdbus_item items[0]; +} __attribute__((__aligned__(8))); + +/** + * Ioctl API + * + * KDBUS_CMD_BUS_MAKE: After opening the "control" node, this command + * creates a new bus with the specified + * name. The bus is immediately shut down and + * cleaned up when the opened file descriptor is + * closed. + * + * KDBUS_CMD_ENDPOINT_MAKE: Creates a new named special endpoint to talk to + * the bus. Such endpoints usually carry a more + * restrictive policy and grant restricted access + * to specific applications. + * KDBUS_CMD_ENDPOINT_UPDATE: Update the properties of a custom enpoint. Used + * to update the policy. + * + * KDBUS_CMD_HELLO: By opening the bus node, a connection is + * created. After a HELLO the opened connection + * becomes an active peer on the bus. + * KDBUS_CMD_UPDATE: Update the properties of a connection. Used to + * update the metadata subscription mask and + * policy. + * KDBUS_CMD_BYEBYE: Disconnect a connection. If there are no + * messages queued up in the connection's pool, + * the call succeeds, and the handle is rendered + * unusable. Otherwise, -EBUSY is returned without + * any further side-effects. + * KDBUS_CMD_FREE: Release the allocated memory in the receiver's + * pool. + * KDBUS_CMD_CONN_INFO: Retrieve credentials and properties of the + * initial creator of the connection. The data was + * stored at registration time and does not + * necessarily represent the connected process or + * the actual state of the process. + * KDBUS_CMD_BUS_CREATOR_INFO: Retrieve information of the creator of the bus + * a connection is attached to. + * + * KDBUS_CMD_SEND: Send a message and pass data from userspace to + * the kernel. + * KDBUS_CMD_RECV: Receive a message from the kernel which is + * placed in the receiver's pool. + * + * KDBUS_CMD_NAME_ACQUIRE: Request a well-known bus name to associate with + * the connection. Well-known names are used to + * address a peer on the bus. + * KDBUS_CMD_NAME_RELEASE: Release a well-known name the connection + * currently owns. + * KDBUS_CMD_LIST: Retrieve the list of all currently registered + * well-known and unique names. + * + * KDBUS_CMD_MATCH_ADD: Install a match which broadcast messages should + * be delivered to the connection. + * KDBUS_CMD_MATCH_REMOVE: Remove a current match for broadcast messages. + */ +enum kdbus_ioctl_type { + /* bus owner (00-0f) */ + KDBUS_CMD_BUS_MAKE = _IOW(KDBUS_IOCTL_MAGIC, 0x00, + struct kdbus_cmd), + + /* endpoint owner (10-1f) */ + KDBUS_CMD_ENDPOINT_MAKE = _IOW(KDBUS_IOCTL_MAGIC, 0x10, + struct kdbus_cmd), + KDBUS_CMD_ENDPOINT_UPDATE = _IOW(KDBUS_IOCTL_MAGIC, 0x11, + struct kdbus_cmd), + + /* connection owner (80-ff) */ + KDBUS_CMD_HELLO = _IOWR(KDBUS_IOCTL_MAGIC, 0x80, + struct kdbus_cmd_hello), + KDBUS_CMD_UPDATE = _IOW(KDBUS_IOCTL_MAGIC, 0x81, + struct kdbus_cmd), + KDBUS_CMD_BYEBYE = _IOW(KDBUS_IOCTL_MAGIC, 0x82, + struct kdbus_cmd), + KDBUS_CMD_FREE = _IOW(KDBUS_IOCTL_MAGIC, 0x83, + struct kdbus_cmd_free), + KDBUS_CMD_CONN_INFO = _IOR(KDBUS_IOCTL_MAGIC, 0x84, + struct kdbus_cmd_info), + KDBUS_CMD_BUS_CREATOR_INFO = _IOR(KDBUS_IOCTL_MAGIC, 0x85, + struct kdbus_cmd_info), + KDBUS_CMD_LIST = _IOR(KDBUS_IOCTL_MAGIC, 0x86, + struct kdbus_cmd_list), + + KDBUS_CMD_SEND = _IOW(KDBUS_IOCTL_MAGIC, 0x90, + struct kdbus_cmd_send), + KDBUS_CMD_RECV = _IOR(KDBUS_IOCTL_MAGIC, 0x91, + struct kdbus_cmd_recv), + + KDBUS_CMD_NAME_ACQUIRE = _IOW(KDBUS_IOCTL_MAGIC, 0xa0, + struct kdbus_cmd), + KDBUS_CMD_NAME_RELEASE = _IOW(KDBUS_IOCTL_MAGIC, 0xa1, + struct kdbus_cmd), + + KDBUS_CMD_MATCH_ADD = _IOW(KDBUS_IOCTL_MAGIC, 0xb0, + struct kdbus_cmd_match), + KDBUS_CMD_MATCH_REMOVE = _IOW(KDBUS_IOCTL_MAGIC, 0xb1, + struct kdbus_cmd_match), +}; + +#endif /* _KDBUS_UAPI_H_ */