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Diffstat (limited to 'ipc/kdbus/message.h')
| -rw-r--r-- | ipc/kdbus/message.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/ipc/kdbus/message.h b/ipc/kdbus/message.h new file mode 100644 index 000000000..298f9c99d --- /dev/null +++ b/ipc/kdbus/message.h @@ -0,0 +1,120 @@ +/* + * Copyright (C) 2013-2015 Kay Sievers + * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org> + * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org> + * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com> + * Copyright (C) 2013-2015 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_MESSAGE_H +#define __KDBUS_MESSAGE_H + +#include <linux/fs.h> +#include <linux/kref.h> +#include <uapi/linux/kdbus.h> + +struct kdbus_bus; +struct kdbus_conn; +struct kdbus_meta_conn; +struct kdbus_meta_proc; +struct kdbus_pool_slice; + +/** + * struct kdbus_gaps - gaps in message to be filled later + * @kref: Reference counter + * @n_memfd_offs: Number of memfds + * @memfd_offs: Offsets of kdbus_memfd items in target slice + * @n_fds: Number of fds + * @fds: Array of sent fds + * @fds_offset: Offset of fd-array in target slice + * + * The 'gaps' object is used to track data that is needed to fill gaps in a + * message at RECV time. Usually, we try to compile the whole message at SEND + * time. This has the advantage, that we don't have to cache any information and + * can keep the memory consumption small. Furthermore, all copy operations can + * be combined into a single function call, which speeds up transactions + * considerably. + * However, things like file-descriptors can only be fully installed at RECV + * time. The gaps object tracks this data and pins it until a message is + * received. The gaps object is shared between all receivers of the same + * message. + */ +struct kdbus_gaps { + struct kref kref; + + /* state tracking for KDBUS_ITEM_PAYLOAD_MEMFD entries */ + size_t n_memfds; + u64 *memfd_offsets; + struct file **memfd_files; + + /* state tracking for KDBUS_ITEM_FDS */ + size_t n_fds; + struct file **fd_files; + u64 fd_offset; +}; + +struct kdbus_gaps *kdbus_gaps_ref(struct kdbus_gaps *gaps); +struct kdbus_gaps *kdbus_gaps_unref(struct kdbus_gaps *gaps); +int kdbus_gaps_install(struct kdbus_gaps *gaps, struct kdbus_pool_slice *slice, + bool *out_incomplete); + +/** + * struct kdbus_staging - staging area to import messages + * @msg: User-supplied message + * @gaps: Gaps-object created during import (or NULL if empty) + * @msg_seqnum: Message sequence number + * @notify_entry: Entry into list of kernel-generated notifications + * @i_payload: Current relative index of start of payload + * @n_payload: Total number of bytes needed for payload + * @n_parts: Number of parts + * @parts: Array of iovecs that make up the whole message + * @meta_proc: Process metadata of the sender (or NULL if empty) + * @meta_conn: Connection metadata of the sender (or NULL if empty) + * @bloom_filter: Pointer to the bloom-item in @msg, or NULL + * @dst_name: Pointer to the dst-name-item in @msg, or NULL + * @notify: Pointer to the notification item in @msg, or NULL + * + * The kdbus_staging object is a temporary staging area to import user-supplied + * messages into the kernel. It is only used during SEND and dropped once the + * message is queued. Any data that cannot be collected during SEND, is + * collected in a kdbus_gaps object and attached to the message queue. + */ +struct kdbus_staging { + struct kdbus_msg *msg; + struct kdbus_gaps *gaps; + u64 msg_seqnum; + struct list_head notify_entry; + + /* crafted iovecs to copy the message */ + size_t i_payload; + size_t n_payload; + size_t n_parts; + struct iovec *parts; + + /* metadata state */ + struct kdbus_meta_proc *meta_proc; + struct kdbus_meta_conn *meta_conn; + + /* cached pointers into @msg */ + const struct kdbus_bloom_filter *bloom_filter; + const char *dst_name; + struct kdbus_item *notify; +}; + +struct kdbus_staging *kdbus_staging_new_kernel(struct kdbus_bus *bus, + u64 dst, u64 cookie_timeout, + size_t it_size, size_t it_type); +struct kdbus_staging *kdbus_staging_new_user(struct kdbus_bus *bus, + struct kdbus_cmd_send *cmd, + struct kdbus_msg *msg); +struct kdbus_staging *kdbus_staging_free(struct kdbus_staging *staging); +struct kdbus_pool_slice *kdbus_staging_emit(struct kdbus_staging *staging, + struct kdbus_conn *src, + struct kdbus_conn *dst); + +#endif |