-core_initcall(sysctl_init);
-
-static struct ctl_table *is_branch_in(struct ctl_table *branch,
- struct ctl_table *table)
-{
- struct ctl_table *p;
- const char *s = branch->procname;
-
- /* branch should have named subdirectory as its first element */
- if (!s || !branch->child)
- return NULL;
-
- /* ... and nothing else */
- if (branch[1].procname)
- return NULL;
-
- /* table should contain subdirectory with the same name */
- for (p = table; p->procname; p++) {
- if (!p->child)
- continue;
- if (p->procname && strcmp(p->procname, s) == 0)
- return p;
- }
- return NULL;
-}
-
-/* see if attaching q to p would be an improvement */
-static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
-{
- struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
- struct ctl_table *next;
- int is_better = 0;
- int not_in_parent = !p->attached_by;
-
- while ((next = is_branch_in(by, to)) != NULL) {
- if (by == q->attached_by)
- is_better = 1;
- if (to == p->attached_by)
- not_in_parent = 1;
- by = by->child;
- to = next->child;
- }
-
- if (is_better && not_in_parent) {
- q->attached_by = by;
- q->attached_to = to;
- q->parent = p;
- }
-}
-
-/**
- * __register_sysctl_paths - register a sysctl hierarchy
- * @root: List of sysctl headers to register on
- * @namespaces: Data to compute which lists of sysctl entries are visible
- * @path: The path to the directory the sysctl table is in.
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- *
- * The members of the &struct ctl_table structure are used as follows:
- *
- * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
- * enter a sysctl file
- *
- * data - a pointer to data for use by proc_handler
- *
- * maxlen - the maximum size in bytes of the data
- *
- * mode - the file permissions for the /proc/sys file, and for sysctl(2)
- *
- * child - a pointer to the child sysctl table if this entry is a directory, or
- * %NULL.
- *
- * proc_handler - the text handler routine (described below)
- *
- * de - for internal use by the sysctl routines
- *
- * extra1, extra2 - extra pointers usable by the proc handler routines
- *
- * Leaf nodes in the sysctl tree will be represented by a single file
- * under /proc; non-leaf nodes will be represented by directories.
- *
- * sysctl(2) can automatically manage read and write requests through
- * the sysctl table. The data and maxlen fields of the ctl_table
- * struct enable minimal validation of the values being written to be
- * performed, and the mode field allows minimal authentication.
- *
- * There must be a proc_handler routine for any terminal nodes
- * mirrored under /proc/sys (non-terminals are handled by a built-in
- * directory handler). Several default handlers are available to
- * cover common cases -
- *
- * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
- * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
- * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
- *
- * It is the handler's job to read the input buffer from user memory
- * and process it. The handler should return 0 on success.
- *
- * This routine returns %NULL on a failure to register, and a pointer
- * to the table header on success.
- */
-struct ctl_table_header *__register_sysctl_paths(
- struct ctl_table_root *root,
- struct nsproxy *namespaces,
- const struct ctl_path *path, struct ctl_table *table)
-{
- struct ctl_table_header *header;
- struct ctl_table *new, **prevp;
- unsigned int n, npath;
- struct ctl_table_set *set;
-
- /* Count the path components */
- for (npath = 0; path[npath].procname; ++npath)
- ;
-
- /*
- * For each path component, allocate a 2-element ctl_table array.
- * The first array element will be filled with the sysctl entry
- * for this, the second will be the sentinel (procname == 0).
- *
- * We allocate everything in one go so that we don't have to
- * worry about freeing additional memory in unregister_sysctl_table.
- */
- header = kzalloc(sizeof(struct ctl_table_header) +
- (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
- if (!header)
- return NULL;
-
- new = (struct ctl_table *) (header + 1);
-
- /* Now connect the dots */
- prevp = &header->ctl_table;
- for (n = 0; n < npath; ++n, ++path) {
- /* Copy the procname */
- new->procname = path->procname;
- new->mode = 0555;
-
- *prevp = new;
- prevp = &new->child;
-
- new += 2;
- }
- *prevp = table;
- header->ctl_table_arg = table;
-
- INIT_LIST_HEAD(&header->ctl_entry);
- header->used = 0;
- header->unregistering = NULL;
- header->root = root;
- sysctl_set_parent(NULL, header->ctl_table);
- header->count = 1;
-#ifdef CONFIG_SYSCTL_SYSCALL_CHECK
- if (sysctl_check_table(namespaces, header->ctl_table)) {
- kfree(header);
- return NULL;
- }
-#endif
- spin_lock(&sysctl_lock);
- header->set = lookup_header_set(root, namespaces);
- header->attached_by = header->ctl_table;
- header->attached_to = root_table;
- header->parent = &root_table_header;
- for (set = header->set; set; set = set->parent) {
- struct ctl_table_header *p;
- list_for_each_entry(p, &set->list, ctl_entry) {
- if (p->unregistering)
- continue;
- try_attach(p, header);
- }
- }
- header->parent->count++;
- list_add_tail(&header->ctl_entry, &header->set->list);
- spin_unlock(&sysctl_lock);
-
- return header;
-}
-
-/**
- * register_sysctl_table_path - register a sysctl table hierarchy
- * @path: The path to the directory the sysctl table is in.
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- *
- * See __register_sysctl_paths for more details.
- */
-struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
- struct ctl_table *table)
-{
- return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
- path, table);
-}
-
-/**
- * register_sysctl_table - register a sysctl table hierarchy
- * @table: the top-level table structure
- *
- * Register a sysctl table hierarchy. @table should be a filled in ctl_table
- * array. A completely 0 filled entry terminates the table.
- *
- * See register_sysctl_paths for more details.
- */
-struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
-{
- static const struct ctl_path null_path[] = { {} };
-
- return register_sysctl_paths(null_path, table);
-}
-
-/**
- * unregister_sysctl_table - unregister a sysctl table hierarchy
- * @header: the header returned from register_sysctl_table
- *
- * Unregisters the sysctl table and all children. proc entries may not
- * actually be removed until they are no longer used by anyone.
- */
-void unregister_sysctl_table(struct ctl_table_header * header)
-{
- might_sleep();
-
- if (header == NULL)
- return;
-
- spin_lock(&sysctl_lock);
- start_unregistering(header);
- if (!--header->parent->count) {
- WARN_ON(1);
- kfree_rcu(header->parent, rcu);
- }
- if (!--header->count)
- kfree_rcu(header, rcu);
- spin_unlock(&sysctl_lock);
-}
-
-int sysctl_is_seen(struct ctl_table_header *p)
-{
- struct ctl_table_set *set = p->set;
- int res;
- spin_lock(&sysctl_lock);
- if (p->unregistering)
- res = 0;
- else if (!set->is_seen)
- res = 1;
- else
- res = set->is_seen(set);
- spin_unlock(&sysctl_lock);
- return res;
-}
-
-void setup_sysctl_set(struct ctl_table_set *p,
- struct ctl_table_set *parent,
- int (*is_seen)(struct ctl_table_set *))
-{
- INIT_LIST_HEAD(&p->list);
- p->parent = parent ? parent : &sysctl_table_root.default_set;
- p->is_seen = is_seen;
-}
-
-#else /* !CONFIG_SYSCTL */
-struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
-{
- return NULL;
-}
-
-struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
- struct ctl_table *table)
-{
- return NULL;
-}
-
-void unregister_sysctl_table(struct ctl_table_header * table)
-{
-}
-
-void setup_sysctl_set(struct ctl_table_set *p,
- struct ctl_table_set *parent,
- int (*is_seen)(struct ctl_table_set *))
-{
-}
-
-void sysctl_head_put(struct ctl_table_header *head)
-{
-}
-