/* SPDX-License-Identifier: (BSD-2-Clause OR GPL-2.0-or-later)
* (C) 2019-2021 AVM GmbH <info@avm.de>
*
* vim:set noexpandtab shiftwidth=8 softtabstop=8 fileencoding=utf-8:
*
* Simple handling of linux kernel proc fs trees
*/
#ifndef SHAREDLIBS_CPROCFS_H
#define SHAREDLIBS_CPROCFS_H
#ifdef CONFIG_PROC_FS
#include <linux/version.h>
#include <linux/proc_fs.h>
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 6, 0)
/* The wrappers are public for anyone who needs to use the procfs API directly (like
* cprocfs internally). So just include cprocfs.h and use either cprocfs or the
* new-style procfs kernel API (even on old kernels).
*
* See mainline commits:
* commit 97a32539b956 proc: convert everything to "struct proc_ops"
* commit d56c0d45f0e2 proc: decouple proc from VFS with "struct proc_ops"
*
* proc_ops replaces file_operations and must be passed to proc_* interfaces.
*
* Conversion rule (see commit 97a32539b956):
* llseek => proc_lseek
* unlocked_ioctl => proc_ioctl
* * => proc_*
* owner => delete assignment
*/
#ifndef CPROCFS_NO_PROC_OPS
/* Define if you don't want CPROCFS_NO_PROC_OPS, e.g. if the proc_read
* definition conflicts with members in unrelated types.
*/
struct proc_ops {
#define proc_open _proc_fops.open
#define proc_read _proc_fops.read
#define proc_write _proc_fops.write
#define proc_lseek _proc_fops.llseek
#define proc_ioctl _proc_fops.unlocked_ioctl
#define proc_release _proc_fops.release
struct file_operations _proc_fops;
};
#define proc_create_data(name, mode, proc_dir, proc_ops, data) \
proc_create_data(name, mode, proc_dir, &(proc_ops)->_proc_fops, data)
#define proc_create(name, mode, proc_dir, proc_ops) \
proc_create(name, mode, proc_dir, &(proc_ops)->_proc_fops)
#endif /* CPROCFS_NO_PROC_OPS */
#endif
/* --------------------------------------------------------------------- */
typedef int (*cprocfs_walk_cb_t)(void *, const char *, ...) __attribute__((format(printf, 2, 3)));
struct cprocfs_file;
struct cprocfs_dir {
struct cprocfs_dir *next;
const char *name;
bool is_root;
struct cprocfs_dir *parent; /* NULL if is_root or not attached */
struct proc_dir_entry *proc_dir;
struct cprocfs_file *cfiles;
struct cprocfs_dir *cdirs;
};
struct cprocfs_file {
struct cprocfs_file *next;
struct cprocfs_dir *cdir;
const char *name;
struct proc_dir_entry *procfs_file;
void (*showfunc)(void *userdata, cprocfs_walk_cb_t cb, void *arg);
void (*control)(void *userdata, int argc, char *argv[]);
void *userdata;
};
/* --------------------------------------------------------------------- */
/**
* cprocfs_create_root_dir: set root proc_dir_entry of a cprocfs_root.
*
* @param name name of directory
*
*/
struct cprocfs_dir *cprocfs_create_root_dir(const char *name);
/**
* cprocfs_destroy: remove all files and directories under 'root'
*
* @param root tree to destroy (NOT NULL).
*
*/
void cprocfs_destroy(struct cprocfs_dir *root);
/* --------------------------------------------------------------------- */
/**
* cprocfs_add_dir: add a directory to a directory.
*
* @param cdir parent directory (NOT NULL).
*
* @returns cprocfs_dir or NULL (kmalloc() failed).
*/
struct cprocfs_dir *cprocfs_add_dir(struct cprocfs_dir *cdir, const char *name);
/**
* cprocfs_delete_dir: remove a directory tree
*
* @param cdir directory to remove (NOT NULL).
*/
void cprocfs_delete_dir(struct cprocfs_dir *cdir);
/**
* cprocfs_register_file: add a readonly file
*
* @param cdir directory NOT NULL
* @param name name of file
* @param userdata used as first argument for 'showfunc'
* @param showfunc 'read' function.
*
* @retval 0 file registered
* @retval -1 kmalloc failed
*/
int cprocfs_register_file(struct cprocfs_dir *cdir,
const char *name,
void (*showfunc)(void *userdata, cprocfs_walk_cb_t cb, void *arg),
void *userdata);
/**
* cprocfs_register_control: add a readwrite file
*
* @param cdir directory NOT NULL
* @param name name of file
* @param showfunc 'read' function.
* @param control 'write' function.
* @param userdata used as first argument for 'showfunc' and 'control'
*
* @retval 0 file registered
* @retval -1 kmalloc failed
*/
int cprocfs_register_control(struct cprocfs_dir *cdir,
const char *name,
void (*showfunc)(void *userdata, cprocfs_walk_cb_t cb, void *arg),
void (*control)(void *userdata, int argc, char *argv[]),
void *userdata);
/* --------------------------------------------------------------------- */
/**
* cprocfs_create_detached_dir: create a cprocfs_dir without parent
*
* can be attached with cprocfs_attach_dir().
*
* @param name name of directory
*
* @returns cprocfs_dir or NULL
*/
struct cprocfs_dir *cprocfs_create_detached_dir(const char *name);
/**
* cprocfs_attach_dir: add a directory to a directory.
*
* @param parent directory where 'child' will be attached (NOT NULL).
* @param child directory to add to 'parent' (NOT NULL).
*/
void cprocfs_attach_dir(struct cprocfs_dir *parent, struct cprocfs_dir *child);
/**
* cprocfs_rename_dir: rename a detached directory.
*
* @param cdir directory to rename (NOT NULL).
*
* @retval 0 directory renamed
* @retval -1 directory already detached
*/
int cprocfs_rename_dir(struct cprocfs_dir *cdir, const char *name);
/**
* cprocfs_walk: walk over directory tree and output information
*
* @param cdir directory to start (NOT NULL).
* @param cb function (if NULL output will be done via printk)
* @param arg arg to function
*
* @returns number of objects visited
*/
unsigned int cprocfs_walk(struct cprocfs_dir *cdir, cprocfs_walk_cb_t cb, void *arg);
/* --------------------------------------------------------------------- */
#endif /* CONFIG_PROCFS */
#endif /* SHAREDLIBS_CPROCFS_H */