linux/ipc/mq_sysctl.c
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   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
  13static 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
  21static int proc_mq_dointvec(struct ctl_table *table, int write,
  22                            void *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
  31static int proc_mq_dointvec_minmax(struct ctl_table *table, int write,
  32                void *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
  46static int msg_max_limit_min = MIN_MSGMAX;
  47static int msg_max_limit_max = HARD_MSGMAX;
  48
  49static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
  50static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
  51
  52static 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
  99static struct ctl_table mq_sysctl_dir[] = {
 100        {
 101                .procname       = "mqueue",
 102                .mode           = 0555,
 103                .child          = mq_sysctls,
 104        },
 105        {}
 106};
 107
 108static struct ctl_table mq_sysctl_root[] = {
 109        {
 110                .procname       = "fs",
 111                .mode           = 0555,
 112                .child          = mq_sysctl_dir,
 113        },
 114        {}
 115};
 116
 117struct ctl_table_header *mq_register_sysctl_table(void)
 118{
 119        return register_sysctl_table(mq_sysctl_root);
 120}
 121