ipc/mq_sysctl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Copyright (C) 2007 IBM Corporation
   4  *
   5  *  Author: Cedric Le Goater <clg@fr.ibm.com>
   6  */
   7
   8 #include <linux/nsproxy.h>
   9 #include <linux/ipc_namespace.h>
  10 #include <linux/sysctl.h>
  11
  12 #ifdef CONFIG_PROC_SYSCTL
  13 static void *get_mq(struct ctl_table *table)
  14 {
  15         char *which = table->data;
  16         struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
  17         which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
  18         return which;
  19 }
  20
  21 static int proc_mq_dointvec(struct ctl_table *table, int write,
  22                             void __user *buffer, size_t *lenp, loff_t *ppos)
  23 {
  24         struct ctl_table mq_table;
  25         memcpy(&mq_table, table, sizeof(mq_table));
  26         mq_table.data = get_mq(table);
  27
  28         return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
  29 }
  30
  31 static int proc_mq_dointvec_minmax(struct ctl_table *table, int write,
  32         void __user *buffer, size_t *lenp, loff_t *ppos)
  33 {
  34         struct ctl_table mq_table;
  35         memcpy(&mq_table, table, sizeof(mq_table));
  36         mq_table.data = get_mq(table);
  37
  38         return proc_dointvec_minmax(&mq_table, write, buffer,
  39                                         lenp, ppos);
  40 }
  41 #else
  42 #define proc_mq_dointvec NULL
  43 #define proc_mq_dointvec_minmax NULL
  44 #endif
  45
  46 static int msg_max_limit_min = MIN_MSGMAX;
  47 static int msg_max_limit_max = HARD_MSGMAX;
  48
  49 static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
  50 static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
  51
  52 static struct ctl_table mq_sysctls[] = {
  53         {
  54                 .procname       = "queues_max",
  55                 .data           = &init_ipc_ns.mq_queues_max,
  56                 .maxlen         = sizeof(int),
  57                 .mode           = 0644,
  58                 .proc_handler   = proc_mq_dointvec,
  59         },
  60         {
  61                 .procname       = "msg_max",
  62                 .data           = &init_ipc_ns.mq_msg_max,
  63                 .maxlen         = sizeof(int),
  64                 .mode           = 0644,
  65                 .proc_handler   = proc_mq_dointvec_minmax,
  66                 .extra1         = &msg_max_limit_min,
  67                 .extra2         = &msg_max_limit_max,
  68         },
  69         {
  70                 .procname       = "msgsize_max",
  71                 .data           = &init_ipc_ns.mq_msgsize_max,
  72                 .maxlen         = sizeof(int),
  73                 .mode           = 0644,
  74                 .proc_handler   = proc_mq_dointvec_minmax,
  75                 .extra1         = &msg_maxsize_limit_min,
  76                 .extra2         = &msg_maxsize_limit_max,
  77         },
  78         {
  79                 .procname       = "msg_default",
  80                 .data           = &init_ipc_ns.mq_msg_default,
  81                 .maxlen         = sizeof(int),
  82                 .mode           = 0644,
  83                 .proc_handler   = proc_mq_dointvec_minmax,
  84                 .extra1         = &msg_max_limit_min,
  85                 .extra2         = &msg_max_limit_max,
  86         },
  87         {
  88                 .procname       = "msgsize_default",
  89                 .data           = &init_ipc_ns.mq_msgsize_default,
  90                 .maxlen         = sizeof(int),
  91                 .mode           = 0644,
  92                 .proc_handler   = proc_mq_dointvec_minmax,
  93                 .extra1         = &msg_maxsize_limit_min,
  94                 .extra2         = &msg_maxsize_limit_max,
  95         },
  96         {}
  97 };
  98
  99 static struct ctl_table mq_sysctl_dir[] = {
 100         {
 101                 .procname       = "mqueue",
 102                 .mode           = 0555,
 103                 .child          = mq_sysctls,
 104         },
 105         {}
 106 };
 107
 108 static struct ctl_table mq_sysctl_root[] = {
 109         {
 110                 .procname       = "fs",
 111                 .mode           = 0555,
 112                 .child          = mq_sysctl_dir,
 113         },
 114         {}
 115 };
 116
 117 struct ctl_table_header *mq_register_sysctl_table(void)
 118 {
 119         return register_sysctl_table(mq_sysctl_root);
 120 }