1 /* 2 * Copyright (C) 2007 3 * 4 * Author: Eric Biederman <[email protected]> 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 int ipc_mni = IPCMNI; 124 int ipc_mni_shift = IPCMNI_SHIFT; 125 126 static struct ctl_table ipc_kern_table[] = { 127 { 128 .procname = "shmmax", 129 .data = &init_ipc_ns.shm_ctlmax, 130 .maxlen = sizeof(init_ipc_ns.shm_ctlmax), 131 .mode = 0644, 132 .proc_handler = proc_ipc_doulongvec_minmax, 133 }, 134 { 135 .procname = "shmall", 136 .data = &init_ipc_ns.shm_ctlall, 137 .maxlen = sizeof(init_ipc_ns.shm_ctlall), 138 .mode = 0644, 139 .proc_handler = proc_ipc_doulongvec_minmax, 140 }, 141 { 142 .procname = "shmmni", 143 .data = &init_ipc_ns.shm_ctlmni, 144 .maxlen = sizeof(init_ipc_ns.shm_ctlmni), 145 .mode = 0644, 146 .proc_handler = proc_ipc_dointvec_minmax, 147 .extra1 = &zero, 148 .extra2 = &ipc_mni, 149 }, 150 { 151 .procname = "shm_rmid_forced", 152 .data = &init_ipc_ns.shm_rmid_forced, 153 .maxlen = sizeof(init_ipc_ns.shm_rmid_forced), 154 .mode = 0644, 155 .proc_handler = proc_ipc_dointvec_minmax_orphans, 156 .extra1 = &zero, 157 .extra2 = &one, 158 }, 159 { 160 .procname = "msgmax", 161 .data = &init_ipc_ns.msg_ctlmax, 162 .maxlen = sizeof(init_ipc_ns.msg_ctlmax), 163 .mode = 0644, 164 .proc_handler = proc_ipc_dointvec_minmax, 165 .extra1 = &zero, 166 .extra2 = &int_max, 167 }, 168 { 169 .procname = "msgmni", 170 .data = &init_ipc_ns.msg_ctlmni, 171 .maxlen = sizeof(init_ipc_ns.msg_ctlmni), 172 .mode = 0644, 173 .proc_handler = proc_ipc_dointvec_minmax, 174 .extra1 = &zero, 175 .extra2 = &ipc_mni, 176 }, 177 { 178 .procname = "auto_msgmni", 179 .data = NULL, 180 .maxlen = sizeof(int), 181 .mode = 0644, 182 .proc_handler = proc_ipc_auto_msgmni, 183 .extra1 = &zero, 184 .extra2 = &one, 185 }, 186 { 187 .procname = "msgmnb", 188 .data = &init_ipc_ns.msg_ctlmnb, 189 .maxlen = sizeof(init_ipc_ns.msg_ctlmnb), 190 .mode = 0644, 191 .proc_handler = proc_ipc_dointvec_minmax, 192 .extra1 = &zero, 193 .extra2 = &int_max, 194 }, 195 { 196 .procname = "sem", 197 .data = &init_ipc_ns.sem_ctls, 198 .maxlen = 4*sizeof(int), 199 .mode = 0644, 200 .proc_handler = proc_ipc_sem_dointvec, 201 }, 202 #ifdef CONFIG_CHECKPOINT_RESTORE 203 { 204 .procname = "sem_next_id", 205 .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id, 206 .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id), 207 .mode = 0644, 208 .proc_handler = proc_ipc_dointvec_minmax, 209 .extra1 = &zero, 210 .extra2 = &int_max, 211 }, 212 { 213 .procname = "msg_next_id", 214 .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id, 215 .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id), 216 .mode = 0644, 217 .proc_handler = proc_ipc_dointvec_minmax, 218 .extra1 = &zero, 219 .extra2 = &int_max, 220 }, 221 { 222 .procname = "shm_next_id", 223 .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id, 224 .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id), 225 .mode = 0644, 226 .proc_handler = proc_ipc_dointvec_minmax, 227 .extra1 = &zero, 228 .extra2 = &int_max, 229 }, 230 #endif 231 {} 232 }; 233 234 static struct ctl_table ipc_root_table[] = { 235 { 236 .procname = "kernel", 237 .mode = 0555, 238 .child = ipc_kern_table, 239 }, 240 {} 241 }; 242 243 static int __init ipc_sysctl_init(void) 244 { 245 register_sysctl_table(ipc_root_table); 246 return 0; 247 } 248 249 device_initcall(ipc_sysctl_init); 250 251 static int __init ipc_mni_extend(char *str) 252 { 253 ipc_mni = IPCMNI_EXTEND; 254 ipc_mni_shift = IPCMNI_EXTEND_SHIFT; 255 pr_info("IPCMNI extended to %d.\n", ipc_mni); 256 return 0; 257 } 258 early_param("ipcmni_extend", ipc_mni_extend); 259