bus: basic implementation of kdbus client side

1 files changed, 360 insertions, 0 deletions

diff --git a/src/libsystemd-bus/kdbus.h b/src/libsystemd-bus/kdbus.h
new file mode 100644
index 0000000000..ba59fd0d37
--- /dev/null
+++ b/src/libsystemd-bus/kdbus.h
@@ -0,0 +1,360 @@
+/*
+ * Copyright (C) 2013 Kay Sievers
+ * Copyright (C) 2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013 Linux Foundation
+ *
+ * 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_H_
+#define _KDBUS_H_
+
+#ifndef __KERNEL__
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <linux/types.h>
+#endif
+
+#define KDBUS_IOC_MAGIC			0x95
+
+/* Message sent from kernel to userspace, when the owner or starter of
+ * a well-known name changes */
+struct kdbus_manager_msg_name_change {
+	__u64 old_id;
+	__u64 new_id;
+	__u64 flags;		/* 0 or (possibly?) KDBUS_CMD_NAME_IN_QUEUE */
+	char name[0];
+};
+
+struct kdbus_manager_msg_id_change {
+	__u64 id;
+	__u64 flags; /* The kernel flags field from KDBUS_CMD_HELLO */
+};
+
+struct kdbus_creds {
+	__u64 uid;
+	__u64 gid;
+	__u64 pid;
+	__u64 tid;
+
+	/* The starttime of the process PID. This is useful to detect
+	PID overruns from the client side. i.e. if you use the PID to
+	look something up in /proc/$PID/ you can afterwards check the
+	starttime field of it to ensure you didn't run into a PID
+	ovretun. */
+	__u64 starttime;
+};
+
+#define KDBUS_SRC_ID_KERNEL		(0)
+#define KDBUS_DST_ID_WELL_KNOWN_NAME	(0)
+#define KDBUS_MATCH_SRC_ID_ANY		(~0ULL)
+#define KDBUS_DST_ID_BROADCAST		(~0ULL)
+
+/* Message Data Types */
+enum {
+	/* Filled in by userspace */
+	KDBUS_MSG_NULL,			/* empty record */
+	KDBUS_MSG_PAYLOAD,		/* .data */
+	KDBUS_MSG_PAYLOAD_VEC,		/* .data_vec, converted into _PAYLOAD at delivery */
+	KDBUS_MSG_MMAP,			/* .data_vec */
+	KDBUS_MSG_MMAP_DONATE,		/* .data_vec, unmap the memory from the sender */
+	KDBUS_MSG_UNIX_FDS,		/* .data_fds of file descriptors */
+	KDBUS_MSG_BLOOM,		/* for broadcasts, carries bloom filter blob */
+	KDBUS_MSG_DST_NAME,		/* destination's well-known name */
+
+	/* Filled in by kernelspace */
+	KDBUS_MSG_SRC_NAMES	= 0x200,/* NUL separated string list with well-known names of source */
+	KDBUS_MSG_TIMESTAMP,		/* .ts_ns of CLOCK_MONOTONIC */
+	KDBUS_MSG_SRC_CREDS,		/* .creds */
+	KDBUS_MSG_SRC_COMM,		/* optional */
+	KDBUS_MSG_SRC_EXE,		/* optional */
+	KDBUS_MSG_SRC_CMDLINE,		/* optional */
+	KDBUS_MSG_SRC_CGROUP,		/* optional, specified which one */
+	KDBUS_MSG_SRC_CAPS,		/* caps data blob */
+	KDBUS_MSG_SRC_SECLABEL,		/* NUL terminated string */
+	KDBUS_MSG_SRC_AUDIT,		/* array of two uint64_t of audit loginuid + sessiond */
+
+	/* Special messages from kernel, consisting of one and only one of these data blocks */
+	KDBUS_MSG_NAME_ADD	= 0x400,/* .name_change */
+	KDBUS_MSG_NAME_REMOVE,		/* .name_change */
+	KDBUS_MSG_NAME_CHANGE,		/* .name_change */
+	KDBUS_MSG_ID_ADD,		/* .id_change */
+	KDBUS_MSG_ID_REMOVE,		/* .id_change */
+	KDBUS_MSG_ID_CHANGE,		/* .id_change */
+	KDBUS_MSG_REPLY_TIMEOUT,	/* empty, but .reply_cookie in .kdbus_msg is filled in */
+	KDBUS_MSG_REPLY_DEAD,		/* dito */
+};
+
+struct kdbus_vec {
+	__u64 address;
+	__u64 size;
+};
+
+/**
+ * struct  kdbus_msg_data - chain of data blocks
+ *
+ * size: overall data record size
+ * type: kdbus_msg_data_type of data
+ */
+struct kdbus_msg_data {
+	__u64 size;
+	__u64 type;
+	union {
+		/* inline data */
+		__u8 data[0];
+		__u32 data_u32[0];
+		__u64 data_u64[0];
+
+		/* data vector */
+		struct kdbus_vec vec;
+
+		/* specific fields */
+		int fds[0];				/* int array of file descriptors */
+		__u64 ts_ns;				/* timestamp in nanoseconds */
+		struct kdbus_creds creds;
+		struct kdbus_manager_msg_name_change name_change;
+		struct kdbus_manager_msg_id_change id_change;
+	};
+};
+
+enum {
+	KDBUS_MSG_FLAGS_EXPECT_REPLY	= 1,
+	KDBUS_MSG_FLAGS_NO_AUTO_START	= 2, /* possibly? */
+};
+
+enum {
+	KDBUS_PAYLOAD_NONE	= 0,
+	KDBUS_PAYLOAD_DBUS1	= 0x4442757356657231ULL, /* 'DBusVer1' */
+	KDBUS_PAYLOAD_GVARIANT	= 0x4756617269616e74ULL, /* 'GVariant' */
+};
+
+/**
+ * struct kdbus_msg
+ *
+ * set by userspace:
+ * dst_id: destination id
+ * flags: KDBUS_MSG_FLAGS_*
+ * data_size: overall message size
+ * data: data records
+ *
+ * set by kernel:
+ * src_id: who sent the message
+ */
+struct kdbus_msg {
+	__u64 size;
+	__u64 flags;
+	__u64 dst_id;		/* connection, 0 == name in data, ~0 broadcast */
+	__u64 src_id;		/* connection, 0 == kernel */
+	__u64 payload_type;	/* 'DBusVer1', 'GVariant', ... */
+	__u64 cookie;		/* userspace-supplied cookie */
+	union {
+		__u64 cookie_reply;	/* cookie we reply to */
+		__u64 timeout_ns;	/* timespan to wait for reply */
+	};
+	struct kdbus_msg_data data[0];
+};
+
+enum {
+	KDBUS_POLICY_NAME,
+	KDBUS_POLICY_ACCESS,
+};
+
+enum {
+	KDBUS_POLICY_USER,
+	KDBUS_POLICY_GROUP,
+	KDBUS_POLICY_WORLD,
+};
+
+enum {
+	KDBUS_POLICY_RECV	= 4,
+	KDBUS_POLICY_SEND	= 2,
+	KDBUS_POLICY_OWN	= 1,
+};
+
+struct kdbus_policy {
+	__u64 size;
+	__u64 type; /* NAME or ACCESS */
+	union {
+		char name[0];
+		struct {
+			__u32 type;	/* USER, GROUP, WORLD */
+			__u32 bits;	/* RECV, SEND, OWN */
+			__u64 id;	/* uid, gid, 0 */
+		} access;
+	};
+};
+
+struct kdbus_cmd_policy {
+	__u64 size;
+	__u8 buffer[0];	/* a series of KDBUS_POLICY_NAME plus one or more KDBUS_POLICY_ACCESS each. */
+};
+
+enum {
+	KDBUS_CMD_HELLO_STARTER		=  1,
+	KDBUS_CMD_HELLO_ACCEPT_FD	=  2,
+	KDBUS_CMD_HELLO_ACCEPT_MMAP	=  4,
+};
+
+enum {
+	KDBUS_CMD_FNAME_ACCESS_GROUP	=  1,
+	KDBUS_CMD_FNAME_ACCESS_WORLD	=  2,
+};
+
+struct kdbus_cmd_hello {
+	/* userspace → kernel, kernel → userspace */
+	__u64 kernel_flags;	/* userspace specifies its
+				 * capabilities and more, kernel
+				 * returns its capabilites and
+				 * more. Kernel might refuse client's
+				 * capabilities by returning an error
+				 * from KDBUS_CMD_HELLO */
+
+	/* userspace → kernel */
+	__u64 pid;		/* To allow translator services which
+				 * connect to the bus on behalf of
+				 * somebody else, allow specifiying
+				 * the PID of the client to connect on
+				 * behalf on. Normal clients should
+				 * pass this as 0 (i.e. to do things
+				 * under their own PID). Priviliged
+				 * clients can pass != 0, to operate
+				 * on behalf of somebody else. */
+
+	/* kernel → userspace */
+	__u64 bus_flags;	/* this is .flags copied verbatim from
+				 * from original KDBUS_CMD_BUS_MAKE
+				 * ioctl. It's intended to be useful
+				 * to do negotiation of features of
+				 * the payload that is transfreted. */
+	__u64 id;		/* peer id */
+};
+
+struct kdbus_cmd_fname {
+	__u64 size;
+	__u64 kernel_flags;	/* userspace → kernel, kernel → userspace
+				 * When creating a bus/ns/ep feature
+				 * kernel negotiation done the same
+				 * way as for KDBUS_CMD_BUS_MAKE. */
+	__u64 user_flags;	/* userspace → kernel
+				 * When a bus is created this value is
+				 * copied verbatim into the bus
+				 * structure and returned from
+				 * KDBUS_CMD_HELLO, later */
+	char name[0];
+};
+
+enum {
+	/* userspace → kernel */
+	KDBUS_CMD_NAME_REPLACE_EXISTING		=  1,
+	KDBUS_CMD_NAME_QUEUE			=  2,
+	KDBUS_CMD_NAME_ALLOW_REPLACEMENT	=  4,
+	KDBUS_CMD_NAME_STEAL_MESSAGES		=  8,
+
+	/* kernel → userspace */
+	KDBUS_CMD_NAME_IN_QUEUE = 0x200,
+};
+
+struct kdbus_cmd_name {
+	__u64 size;
+	__u64 flags;
+	__u64 id;		/* We allow registration/deregestration of names of other peers */
+	char name[0];
+};
+
+struct kdbus_cmd_names {
+	__u64 size;
+	struct kdbus_cmd_name names[0];
+};
+
+enum {
+	KDBUS_CMD_NAME_INFO_ITEM_NAME,
+	KDBUS_CMD_NAME_INFO_ITEM_SECLABEL,
+	KDBUS_CMD_NAME_INFO_ITEM_AUDIT,
+};
+
+struct kdbus_cmd_name_info_item {
+	__u64 size;
+	__u64 type;
+	__u8 data[0];
+};
+
+struct kdbus_cmd_name_info {
+	__u64 size;			/* overall size of info */
+	__u64 flags;
+	__u64 id;			/* either ID, or 0 and _ITEM_NAME follows */
+	struct kdbus_creds creds;
+	struct kdbus_cmd_name_info_item item[0]; /* list of item records */
+};
+
+enum {
+	KDBUS_CMD_MATCH_BLOOM,		/* Matches a mask blob against KDBUS_MSG_BLOOM */
+	KDBUS_CMD_MATCH_SRC_NAME,	/* Matches a name string against KDBUS_MSG_SRC_NAMES */
+	KDBUS_CMD_MATCH_NAME_ADD,	/* Matches a name string against KDBUS_MSG_NAME_ADD */
+	KDBUS_CMD_MATCH_NAME_REMOVE,	/* Matches a name string against KDBUS_MSG_NAME_REMOVE */
+	KDBUS_CMD_MATCH_NAME_CHANGE,	/* Matches a name string against KDBUS_MSG_NAME_CHANGE */
+	KDBUS_CMD_MATCH_ID_ADD,		/* Matches an ID against KDBUS_MSG_ID_ADD */
+	KDBUS_CMD_MATCH_ID_REMOVE,	/* Matches an ID against KDBUS_MSG_ID_REMOVE */
+	KDBUS_CMD_MATCH_ID_CHANGE,	/* Matches an ID against KDBUS_MSG_ID_CHANGE */
+};
+
+struct kdbus_cmd_match_item {
+	__u64 size;
+	__u64 type;
+	__u8 data[0];
+};
+
+struct kdbus_cmd_match {
+	__u64 size;
+	__u64 id;	/* We allow registration/deregestration of matches for other peers */
+	__u64 cookie;	/* userspace supplied cookie; when removing; kernel deletes everything with same cookie */
+	__u64 src_id;	/* ~0: any. other: exact unique match */
+	struct kdbus_cmd_match_item items[0];
+};
+
+struct kdbus_cmd_monitor {
+	__u64 id;		/* We allow setting the monitor flag of other peers */
+	int enabled;		/* A boolean to enable/disable monitoring */
+};
+
+/* FD states:
+ * control nodes: unset
+ *   bus owner  (via KDBUS_CMD_BUS_MAKE)
+ *   ns owner   (via KDBUS_CMD_NS_MAKE)
+ *
+ * ep nodes: unset
+ *   connected  (via KDBUS_CMD_HELLO)
+ *   starter    (via KDBUS_CMD_HELLO with KDBUS_CMD_HELLO_STARTER)
+ *   ep owner   (via KDBUS_CMD_EP_MAKE)
+ */
+enum kdbus_cmd {
+	/* kdbus control node commands: require unset state */
+	KDBUS_CMD_BUS_MAKE =		_IOWR(KDBUS_IOC_MAGIC, 0x00, struct kdbus_cmd_fname),
+	KDBUS_CMD_NS_MAKE =		_IOWR(KDBUS_IOC_MAGIC, 0x10, struct kdbus_cmd_fname),
+
+	/* kdbus control node commands: require bus owner state */
+	KDBUS_CMD_BUS_POLICY_SET =	_IOWR(KDBUS_IOC_MAGIC, 0x20, struct kdbus_cmd_policy),
+
+	/* kdbus ep node commands: require unset state */
+	KDBUS_CMD_EP_MAKE =		_IOWR(KDBUS_IOC_MAGIC, 0x30, struct kdbus_cmd_fname),
+	KDBUS_CMD_HELLO =		_IOWR(KDBUS_IOC_MAGIC, 0x31, struct kdbus_cmd_hello),
+
+	/* kdbus ep node commands: require connected state */
+	KDBUS_CMD_MSG_SEND =		_IOWR(KDBUS_IOC_MAGIC, 0x40, struct kdbus_msg),
+	KDBUS_CMD_MSG_RECV =		_IOWR(KDBUS_IOC_MAGIC, 0x41, struct kdbus_msg),
+
+	KDBUS_CMD_NAME_ACQUIRE =	_IOWR(KDBUS_IOC_MAGIC, 0x50, struct kdbus_cmd_name),
+	KDBUS_CMD_NAME_RELEASE =	_IOWR(KDBUS_IOC_MAGIC, 0x51, struct kdbus_cmd_name),
+	KDBUS_CMD_NAME_LIST =		_IOWR(KDBUS_IOC_MAGIC, 0x52, struct kdbus_cmd_names),
+	KDBUS_CMD_NAME_QUERY =		_IOWR(KDBUS_IOC_MAGIC, 0x53, struct kdbus_cmd_name_info),
+
+	KDBUS_CMD_MATCH_ADD =		_IOWR(KDBUS_IOC_MAGIC, 0x60, struct kdbus_cmd_match),
+	KDBUS_CMD_MATCH_REMOVE =	_IOWR(KDBUS_IOC_MAGIC, 0x61, struct kdbus_cmd_match),
+	KDBUS_CMD_MONITOR =		_IOWR(KDBUS_IOC_MAGIC, 0x62, struct kdbus_cmd_monitor),
+
+	/* kdbus ep node commands: require ep owner state */
+	KDBUS_CMD_EP_POLICY_SET =	_IOWR(KDBUS_IOC_MAGIC, 0x70, struct kdbus_cmd_policy),
+};
+#endif