1 /* 2 * Copyright (C) 2007 3 * 4 * Author: Eric Biederman <ebiederm@xmision.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/module.h> 13 #include <linux/ipc.h> 14 #include <linux/nsproxy.h> 15 #include <linux/sysctl.h> 16 #include <linux/uaccess.h> 17 #include <linux/ipc_namespace.h> 18 #include <linux/msg.h> 19 #include "util.h" 20 21 static void *get_ipc(struct ctl_table *table) 22 { 23 char *which = table->data; 24 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; 25 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns; 26 return which; 27 } 28 29 #ifdef CONFIG_PROC_SYSCTL 30 static int proc_ipc_dointvec(struct ctl_table *table, int write, 31 void __user *buffer, size_t *lenp, loff_t *ppos) 32 { 33 struct ctl_table ipc_table; 34 35 memcpy(&ipc_table, table, sizeof(ipc_table)); 36 ipc_table.data = get_ipc(table); 37 38 return proc_dointvec(&ipc_table, write, buffer, lenp, ppos); 39 } 40 41 static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write, 42 void __user *buffer, size_t *lenp, loff_t *ppos) 43 { 44 struct ctl_table ipc_table; 45 46 memcpy(&ipc_table, table, sizeof(ipc_table)); 47 ipc_table.data = get_ipc(table); 48 49 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); 50 } 51 52 static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write, 53 void __user *buffer, size_t *lenp, loff_t *ppos) 54 { 55 struct ipc_namespace *ns = current->nsproxy->ipc_ns; 56 int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos); 57 58 if (err < 0) 59 return err; 60 if (ns->shm_rmid_forced) 61 shm_destroy_orphaned(ns); 62 return err; 63 } 64 65 static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write, 66 void __user *buffer, size_t *lenp, loff_t *ppos) 67 { 68 struct ctl_table ipc_table; 69 memcpy(&ipc_table, table, sizeof(ipc_table)); 70 ipc_table.data = get_ipc(table); 71 72 return proc_doulongvec_minmax(&ipc_table, write, buffer, 73 lenp, ppos); 74 } 75 76 static int proc_ipc_auto_msgmni(struct ctl_table *table, int write, 77 void __user *buffer, size_t *lenp, loff_t *ppos) 78 { 79 struct ctl_table ipc_table; 80 int dummy = 0; 81 82 memcpy(&ipc_table, table, sizeof(ipc_table)); 83 ipc_table.data = &dummy; 84 85 if (write) 86 pr_info_once("writing to auto_msgmni has no effect"); 87 88 return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); 89 } 90 91 #else 92 #define proc_ipc_doulongvec_minmax NULL 93 #define proc_ipc_dointvec NULL 94 #define proc_ipc_dointvec_minmax NULL 95 #define proc_ipc_dointvec_minmax_orphans NULL 96 #define proc_ipc_auto_msgmni NULL 97 #endif 98 99 static int zero; 100 static int one = 1; 101 static int int_max = INT_MAX; 102 103 static struct ctl_table ipc_kern_table[] = { 104 { 105 .procname = "shmmax", 106 .data = &init_ipc_ns.shm_ctlmax, 107 .maxlen = sizeof(init_ipc_ns.shm_ctlmax), 108 .mode = 0644, 109 .proc_handler = proc_ipc_doulongvec_minmax, 110 }, 111 { 112 .procname = "shmall", 113 .data = &init_ipc_ns.shm_ctlall, 114 .maxlen = sizeof(init_ipc_ns.shm_ctlall), 115 .mode = 0644, 116 .proc_handler = proc_ipc_doulongvec_minmax, 117 }, 118 { 119 .procname = "shmmni", 120 .data = &init_ipc_ns.shm_ctlmni, 121 .maxlen = sizeof(init_ipc_ns.shm_ctlmni), 122 .mode = 0644, 123 .proc_handler = proc_ipc_dointvec, 124 }, 125 { 126 .procname = "shm_rmid_forced", 127 .data = &init_ipc_ns.shm_rmid_forced, 128 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced), 129 .mode = 0644, 130 .proc_handler = proc_ipc_dointvec_minmax_orphans, 131 .extra1 = &zero, 132 .extra2 = &one, 133 }, 134 { 135 .procname = "msgmax", 136 .data = &init_ipc_ns.msg_ctlmax, 137 .maxlen = sizeof(init_ipc_ns.msg_ctlmax), 138 .mode = 0644, 139 .proc_handler = proc_ipc_dointvec_minmax, 140 .extra1 = &zero, 141 .extra2 = &int_max, 142 }, 143 { 144 .procname = "msgmni", 145 .data = &init_ipc_ns.msg_ctlmni, 146 .maxlen = sizeof(init_ipc_ns.msg_ctlmni), 147 .mode = 0644, 148 .proc_handler = proc_ipc_dointvec_minmax, 149 .extra1 = &zero, 150 .extra2 = &int_max, 151 }, 152 { 153 .procname = "auto_msgmni", 154 .data = NULL, 155 .maxlen = sizeof(int), 156 .mode = 0644, 157 .proc_handler = proc_ipc_auto_msgmni, 158 .extra1 = &zero, 159 .extra2 = &one, 160 }, 161 { 162 .procname = "msgmnb", 163 .data = &init_ipc_ns.msg_ctlmnb, 164 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb), 165 .mode = 0644, 166 .proc_handler = proc_ipc_dointvec_minmax, 167 .extra1 = &zero, 168 .extra2 = &int_max, 169 }, 170 { 171 .procname = "sem", 172 .data = &init_ipc_ns.sem_ctls, 173 .maxlen = 4*sizeof(int), 174 .mode = 0644, 175 .proc_handler = proc_ipc_dointvec, 176 }, 177 #ifdef CONFIG_CHECKPOINT_RESTORE 178 { 179 .procname = "sem_next_id", 180 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id, 181 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id), 182 .mode = 0644, 183 .proc_handler = proc_ipc_dointvec_minmax, 184 .extra1 = &zero, 185 .extra2 = &int_max, 186 }, 187 { 188 .procname = "msg_next_id", 189 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id, 190 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id), 191 .mode = 0644, 192 .proc_handler = proc_ipc_dointvec_minmax, 193 .extra1 = &zero, 194 .extra2 = &int_max, 195 }, 196 { 197 .procname = "shm_next_id", 198 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id, 199 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id), 200 .mode = 0644, 201 .proc_handler = proc_ipc_dointvec_minmax, 202 .extra1 = &zero, 203 .extra2 = &int_max, 204 }, 205 #endif 206 {} 207 }; 208 209 static struct ctl_table ipc_root_table[] = { 210 { 211 .procname = "kernel", 212 .mode = 0555, 213 .child = ipc_kern_table, 214 }, 215 {} 216 }; 217 218 static int __init ipc_sysctl_init(void) 219 { 220 register_sysctl_table(ipc_root_table); 221 return 0; 222 } 223 224 device_initcall(ipc_sysctl_init); 225