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 19 static void *get_ipc(ctl_table *table) 20 { 21 char *which = table->data; 22 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; 23 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns; 24 return which; 25 } 26 27 #ifdef CONFIG_PROC_FS 28 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp, 29 void __user *buffer, size_t *lenp, loff_t *ppos) 30 { 31 struct ctl_table ipc_table; 32 memcpy(&ipc_table, table, sizeof(ipc_table)); 33 ipc_table.data = get_ipc(table); 34 35 return proc_dointvec(&ipc_table, write, filp, buffer, lenp, ppos); 36 } 37 38 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, 39 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos) 40 { 41 struct ctl_table ipc_table; 42 memcpy(&ipc_table, table, sizeof(ipc_table)); 43 ipc_table.data = get_ipc(table); 44 45 return proc_doulongvec_minmax(&ipc_table, write, filp, buffer, 46 lenp, ppos); 47 } 48 49 #else 50 #define proc_ipc_doulongvec_minmax NULL 51 #define proc_ipc_dointvec NULL 52 #endif 53 54 #ifdef CONFIG_SYSCTL_SYSCALL 55 /* The generic sysctl ipc data routine. */ 56 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen, 57 void __user *oldval, size_t __user *oldlenp, 58 void __user *newval, size_t newlen) 59 { 60 size_t len; 61 void *data; 62 63 /* Get out of I don't have a variable */ 64 if (!table->data || !table->maxlen) 65 return -ENOTDIR; 66 67 data = get_ipc(table); 68 if (!data) 69 return -ENOTDIR; 70 71 if (oldval && oldlenp) { 72 if (get_user(len, oldlenp)) 73 return -EFAULT; 74 if (len) { 75 if (len > table->maxlen) 76 len = table->maxlen; 77 if (copy_to_user(oldval, data, len)) 78 return -EFAULT; 79 if (put_user(len, oldlenp)) 80 return -EFAULT; 81 } 82 } 83 84 if (newval && newlen) { 85 if (newlen > table->maxlen) 86 newlen = table->maxlen; 87 88 if (copy_from_user(data, newval, newlen)) 89 return -EFAULT; 90 } 91 return 1; 92 } 93 #else 94 #define sysctl_ipc_data NULL 95 #endif 96 97 static struct ctl_table ipc_kern_table[] = { 98 { 99 .ctl_name = KERN_SHMMAX, 100 .procname = "shmmax", 101 .data = &init_ipc_ns.shm_ctlmax, 102 .maxlen = sizeof (init_ipc_ns.shm_ctlmax), 103 .mode = 0644, 104 .proc_handler = proc_ipc_doulongvec_minmax, 105 .strategy = sysctl_ipc_data, 106 }, 107 { 108 .ctl_name = KERN_SHMALL, 109 .procname = "shmall", 110 .data = &init_ipc_ns.shm_ctlall, 111 .maxlen = sizeof (init_ipc_ns.shm_ctlall), 112 .mode = 0644, 113 .proc_handler = proc_ipc_doulongvec_minmax, 114 .strategy = sysctl_ipc_data, 115 }, 116 { 117 .ctl_name = KERN_SHMMNI, 118 .procname = "shmmni", 119 .data = &init_ipc_ns.shm_ctlmni, 120 .maxlen = sizeof (init_ipc_ns.shm_ctlmni), 121 .mode = 0644, 122 .proc_handler = proc_ipc_dointvec, 123 .strategy = sysctl_ipc_data, 124 }, 125 { 126 .ctl_name = KERN_MSGMAX, 127 .procname = "msgmax", 128 .data = &init_ipc_ns.msg_ctlmax, 129 .maxlen = sizeof (init_ipc_ns.msg_ctlmax), 130 .mode = 0644, 131 .proc_handler = proc_ipc_dointvec, 132 .strategy = sysctl_ipc_data, 133 }, 134 { 135 .ctl_name = KERN_MSGMNI, 136 .procname = "msgmni", 137 .data = &init_ipc_ns.msg_ctlmni, 138 .maxlen = sizeof (init_ipc_ns.msg_ctlmni), 139 .mode = 0644, 140 .proc_handler = proc_ipc_dointvec, 141 .strategy = sysctl_ipc_data, 142 }, 143 { 144 .ctl_name = KERN_MSGMNB, 145 .procname = "msgmnb", 146 .data = &init_ipc_ns.msg_ctlmnb, 147 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb), 148 .mode = 0644, 149 .proc_handler = proc_ipc_dointvec, 150 .strategy = sysctl_ipc_data, 151 }, 152 { 153 .ctl_name = KERN_SEM, 154 .procname = "sem", 155 .data = &init_ipc_ns.sem_ctls, 156 .maxlen = 4*sizeof (int), 157 .mode = 0644, 158 .proc_handler = proc_ipc_dointvec, 159 .strategy = sysctl_ipc_data, 160 }, 161 {} 162 }; 163 164 static struct ctl_table ipc_root_table[] = { 165 { 166 .ctl_name = CTL_KERN, 167 .procname = "kernel", 168 .mode = 0555, 169 .child = ipc_kern_table, 170 }, 171 {} 172 }; 173 174 static int __init ipc_sysctl_init(void) 175 { 176 register_sysctl_table(ipc_root_table); 177 return 0; 178 } 179 180 __initcall(ipc_sysctl_init); 181