LXR linux/ipc/mq

   1/*
   2 *  Copyright (C) 2007 IBM Corporation
   3 *
   4 *  Author: Cedric Le Goater <clg@fr.ibm.com>
   5 *
   6 *  This program is free software; you can redistribute it and/or
   7 *  modify it under the terms of the GNU General Public License as
   8 *  published by the Free Software Foundation, version 2 of the
   9 *  License.
  10 */
  11
  12#include <linux/nsproxy.h>
  13#include <linux/ipc_namespace.h>
  14#include <linux/sysctl.h>
  15
  16/*
  17 * Define the ranges various user-specified maximum values can
  18 * be set to.
  19 */
  20#define MIN_MSGMAX      1               /* min value for msg_max */
  21#define MAX_MSGMAX      HARD_MSGMAX     /* max value for msg_max */
  22#define MIN_MSGSIZEMAX  128             /* min value for msgsize_max */
  23#define MAX_MSGSIZEMAX  (8192*128)      /* max value for msgsize_max */
  24
  25#ifdef CONFIG_PROC_SYSCTL
  26static void *get_mq(ctl_table *table)
  27{
  28        char *which = table->data;
  29        struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
  30        which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
  31        return which;
  32}
  33
  34static int proc_mq_dointvec(ctl_table *table, int write,
  35        void __user *buffer, size_t *lenp, loff_t *ppos)
  36{
  37        struct ctl_table mq_table;
  38        memcpy(&mq_table, table, sizeof(mq_table));
  39        mq_table.data = get_mq(table);
  40
  41        return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
  42}
  43
  44static int proc_mq_dointvec_minmax(ctl_table *table, int write,
  45        void __user *buffer, size_t *lenp, loff_t *ppos)
  46{
  47        struct ctl_table mq_table;
  48        memcpy(&mq_table, table, sizeof(mq_table));
  49        mq_table.data = get_mq(table);
  50
  51        return proc_dointvec_minmax(&mq_table, write, buffer,
  52                                        lenp, ppos);
  53}
  54#else
  55#define proc_mq_dointvec NULL
  56#define proc_mq_dointvec_minmax NULL
  57#endif
  58
  59static int msg_max_limit_min = MIN_MSGMAX;
  60static int msg_max_limit_max = MAX_MSGMAX;
  61
  62static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
  63static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
  64
  65static ctl_table mq_sysctls[] = {
  66        {
  67                .procname       = "queues_max",
  68                .data           = &init_ipc_ns.mq_queues_max,
  69                .maxlen         = sizeof(int),
  70                .mode           = 0644,
  71                .proc_handler   = proc_mq_dointvec,
  72        },
  73        {
  74                .procname       = "msg_max",
  75                .data           = &init_ipc_ns.mq_msg_max,
  76                .maxlen         = sizeof(int),
  77                .mode           = 0644,
  78                .proc_handler   = proc_mq_dointvec_minmax,
  79                .extra1         = &msg_max_limit_min,
  80                .extra2         = &msg_max_limit_max,
  81        },
  82        {
  83                .procname       = "msgsize_max",
  84                .data           = &init_ipc_ns.mq_msgsize_max,
  85                .maxlen         = sizeof(int),
  86                .mode           = 0644,
  87                .proc_handler   = proc_mq_dointvec_minmax,
  88                .extra1         = &msg_maxsize_limit_min,
  89                .extra2         = &msg_maxsize_limit_max,
  90        },
  91        {}
  92};
  93
  94static ctl_table mq_sysctl_dir[] = {
  95        {
  96                .procname       = "mqueue",
  97                .mode           = 0555,
  98                .child          = mq_sysctls,
  99        },
 100        {}
 101};
 102
 103static ctl_table mq_sysctl_root[] = {
 104        {
 105                .procname       = "fs",
 106                .mode           = 0555,
 107                .child          = mq_sysctl_dir,
 108        },
 109        {}
 110};
 111
 112struct ctl_table_header *mq_register_sysctl_table(void)
 113{
 114        return register_sysctl_table(mq_sysctl_root);
 115}
 116