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/*
* Copyright IBM Corporation. 2007
*
* Author: Balbir Singh <balbir@linux.vnet.ibm.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#ifndef _LIBCG_H
#define _LIBCG_H
#include <grp.h>
#include <sys/stat.h>
#define _GNU_SOURCE
#define __USE_GNU
/* Maximum number of mount points/controllers */
#define MAX_MNT_ELEMENTS 8
/* Estimated number of groups created */
#define MAX_GROUP_ELEMENTS 128
int verbose;
#ifdef DEBUG
#define dbg(x...) if (verbose) { \
printf(x); \
}
#else
#define dbg(x...) do { } while(0)
#endif
/*
* NOTE: Wide characters are not supported at the moment. Wide character support
* would require us to use a scanner/parser that can parse beyond ASCII
*/
/*
* These data structures are heavily controller dependent, which means
* any changes (additions/removal) of configuration items would have to
* be reflected in this library. We might implement a plugin
* infrastructure, so that we can deal with such changes with ease.
*/
struct cpu_controller {
/*TODO: Add the cpu.usage file here, also need to automate this.*/
char *shares; /* Having strings helps us write them to files */
/*
* XX: No it does not make a difference. It requires a fprintf anyway
* so it needs the qualifier.
*/
};
struct cg_group {
char *name;
uid_t tasks_uid;
gid_t tasks_gid;
uid_t admin_uid;
gid_t admin_gid;
struct cpu_controller cpu_config;
};
/*
* A singly linked list suffices since we don't expect too many mount points
*/
struct mount_table {
char *options; /* Name(s) of the controller */
char *mount_point; /* The place where the controller is mounted */
struct mount_table *next;
};
/*
* Maintain a list of all group names. These will be used during cleanup
*/
/* XX: Why a recursive structure? */
struct list_of_names {
char *name;
struct list_of_names *next;
};
enum cg_msg_type {
CG_MSG_LOAD_FILE,
CG_MSG_UNLOAD_FILE,
CG_MSG_ERR,
CG_MSG_DONE,
};
#define CG_MAX_MSG_SIZE 256
#define CG_SERVER_MSG_PATH "/tmp/control_group"
#define CG_BACKLOG 5
/* Message's exchanged between server and client */
struct cg_msg {
enum cg_msg_type type;
char buf[CG_MAX_MSG_SIZE];
};
/* Function Prototypes start here */
int cg_init_group_and_mount_info(void);
int cg_insert_into_mount_table(const char *name, const char *mount_point);
void cg_cleanup_mount_table(void);
int cg_group_admin_perm(char *perm_type, char *value);
int cg_group_task_perm(char *perm_type, char *value);
int cg_parse_controller_options(char *controller, char *name_value);
int cg_insert_group(const char *group_name);
int chown_recursive(const char* path, uid_t owner, gid_t group);
int cg_make_directory(struct cg_group *cg_group, const char *group_path);
char *cg_build_group_path(struct cg_group *cg_group,
struct mount_table *mount_info);
int cg_mount_controllers(void);
int cg_unmount_controllers(void);
int cg_load_config(const char *pathname);
void cg_unload_current_config(void);
#endif /* _LIBCG_H */
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