ipc/mq_sysctl.c

   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
  26 static 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
  34 static int proc_mq_dointvec(ctl_table *table, int write, struct file *filp,
  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, filp, buffer, lenp, ppos);
  42 }
  43
  44 static int proc_mq_dointvec_minmax(ctl_table *table, int write,
  45         struct file *filp, 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, filp, buffer,
  52                                         lenp, ppos);
  53 }
  54 #else
  55 #define proc_mq_dointvec NULL
  56 #define proc_mq_dointvec_minmax NULL
  57 #endif
  58
  59 static int msg_max_limit_min = MIN_MSGMAX;
  60 static int msg_max_limit_max = MAX_MSGMAX;
  61
  62 static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
  63 static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
  64
  65 static 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         { .ctl_name = 0 }
  92 };
  93
  94 static ctl_table mq_sysctl_dir[] = {
  95         {
  96                 .procname       = "mqueue",
  97                 .mode           = 0555,
  98                 .child          = mq_sysctls,
  99         },
 100         { .ctl_name = 0 }
 101 };
 102
 103 static ctl_table mq_sysctl_root[] = {
 104         {
 105                 .ctl_name       = CTL_FS,
 106                 .procname       = "fs",
 107                 .mode           = 0555,
 108                 .child          = mq_sysctl_dir,
 109         },
 110         { .ctl_name = 0 }
 111 };
 112
 113 struct ctl_table_header *mq_register_sysctl_table(void)
 114 {
 115         return register_sysctl_table(mq_sysctl_root);
 116 }