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 static int proc_ipc_sem_dointvec(struct ctl_table *table, int write, 92 void __user *buffer, size_t *lenp, loff_t *ppos) 93 { 94 int ret, semmni; 95 struct ipc_namespace *ns = current->nsproxy->ipc_ns; 96 97 semmni = ns->sem_ctls[3]; 98 ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos); 99 100 if (!ret) 101 ret = sem_check_semmni(current->nsproxy->ipc_ns); 102 103 /* 104 * Reset the semmni value if an error happens. 105 */ 106 if (ret) 107 ns->sem_ctls[3] = semmni; 108 return ret; 109 } 110 111 #else 112 #define proc_ipc_doulongvec_minmax NULL 113 #define proc_ipc_dointvec NULL 114 #define proc_ipc_dointvec_minmax NULL 115 #define proc_ipc_dointvec_minmax_orphans NULL 116 #define proc_ipc_auto_msgmni NULL 117 #define proc_ipc_sem_dointvec NULL 118 #endif 119 120 static int zero; 121 static int one = 1; 122 static int int_max = INT_MAX; 123 static int ipc_mni = IPCMNI; 124 125 static struct ctl_table ipc_kern_table[] = { 126 { 127 .procname = "shmmax", 128 .data = &init_ipc_ns.shm_ctlmax, 129 .maxlen = sizeof(init_ipc_ns.shm_ctlmax), 130 .mode = 0644, 131 .proc_handler = proc_ipc_doulongvec_minmax, 132 }, 133 { 134 .procname = "shmall", 135 .data = &init_ipc_ns.shm_ctlall, 136 .maxlen = sizeof(init_ipc_ns.shm_ctlall), 137 .mode = 0644, 138 .proc_handler = proc_ipc_doulongvec_minmax, 139 }, 140 { 141 .procname = "shmmni", 142 .data = &init_ipc_ns.shm_ctlmni, 143 .maxlen = sizeof(init_ipc_ns.shm_ctlmni), 144 .mode = 0644, 145 .proc_handler = proc_ipc_dointvec_minmax, 146 .extra1 = &zero, 147 .extra2 = &ipc_mni, 148 }, 149 { 150 .procname = "shm_rmid_forced", 151 .data = &init_ipc_ns.shm_rmid_forced, 152 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced), 153 .mode = 0644, 154 .proc_handler = proc_ipc_dointvec_minmax_orphans, 155 .extra1 = &zero, 156 .extra2 = &one, 157 }, 158 { 159 .procname = "msgmax", 160 .data = &init_ipc_ns.msg_ctlmax, 161 .maxlen = sizeof(init_ipc_ns.msg_ctlmax), 162 .mode = 0644, 163 .proc_handler = proc_ipc_dointvec_minmax, 164 .extra1 = &zero, 165 .extra2 = &int_max, 166 }, 167 { 168 .procname = "msgmni", 169 .data = &init_ipc_ns.msg_ctlmni, 170 .maxlen = sizeof(init_ipc_ns.msg_ctlmni), 171 .mode = 0644, 172 .proc_handler = proc_ipc_dointvec_minmax, 173 .extra1 = &zero, 174 .extra2 = &ipc_mni, 175 }, 176 { 177 .procname = "auto_msgmni", 178 .data = NULL, 179 .maxlen = sizeof(int), 180 .mode = 0644, 181 .proc_handler = proc_ipc_auto_msgmni, 182 .extra1 = &zero, 183 .extra2 = &one, 184 }, 185 { 186 .procname = "msgmnb", 187 .data = &init_ipc_ns.msg_ctlmnb, 188 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb), 189 .mode = 0644, 190 .proc_handler = proc_ipc_dointvec_minmax, 191 .extra1 = &zero, 192 .extra2 = &int_max, 193 }, 194 { 195 .procname = "sem", 196 .data = &init_ipc_ns.sem_ctls, 197 .maxlen = 4*sizeof(int), 198 .mode = 0644, 199 .proc_handler = proc_ipc_sem_dointvec, 200 }, 201 #ifdef CONFIG_CHECKPOINT_RESTORE 202 { 203 .procname = "sem_next_id", 204 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id, 205 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id), 206 .mode = 0644, 207 .proc_handler = proc_ipc_dointvec_minmax, 208 .extra1 = &zero, 209 .extra2 = &int_max, 210 }, 211 { 212 .procname = "msg_next_id", 213 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id, 214 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id), 215 .mode = 0644, 216 .proc_handler = proc_ipc_dointvec_minmax, 217 .extra1 = &zero, 218 .extra2 = &int_max, 219 }, 220 { 221 .procname = "shm_next_id", 222 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id, 223 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id), 224 .mode = 0644, 225 .proc_handler = proc_ipc_dointvec_minmax, 226 .extra1 = &zero, 227 .extra2 = &int_max, 228 }, 229 #endif 230 {} 231 }; 232 233 static struct ctl_table ipc_root_table[] = { 234 { 235 .procname = "kernel", 236 .mode = 0555, 237 .child = ipc_kern_table, 238 }, 239 {} 240 }; 241 242 static int __init ipc_sysctl_init(void) 243 { 244 register_sysctl_table(ipc_root_table); 245 return 0; 246 } 247 248 device_initcall(ipc_sysctl_init); 249