/* * Copyright (C) 2007 * * Author: Eric Biederman <ebiederm@xmision.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation, version 2 of the * License. */ #include <linux/module.h> #include <linux/ipc.h> #include <linux/nsproxy.h> #include <linux/sysctl.h> #include <linux/uaccess.h> #include <linux/ipc_namespace.h> #include <linux/msg.h> #include "util.h" static void *get_ipc(struct ctl_table *table) { char *which = table->data; struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns; return which; } #ifdef CONFIG_PROC_SYSCTL static int proc_ipc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); return proc_dointvec(&ipc_table, write, buffer, lenp, ppos); } static int proc_ipc_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); } static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ipc_namespace *ns = current->nsproxy->ipc_ns; int err = proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos); if (err < 0) return err; if (ns->shm_rmid_forced) shm_destroy_orphaned(ns); return err; } static int proc_ipc_callback_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; size_t lenp_bef = *lenp; int rc; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); if (write && !rc && lenp_bef == *lenp) /* * Tunable has successfully been changed by hand. Disable its * automatic adjustment. This simply requires unregistering * the notifiers that trigger recalculation. */ unregister_ipcns_notifier(current->nsproxy->ipc_ns); return rc; } static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); return proc_doulongvec_minmax(&ipc_table, write, buffer, lenp, ppos); } /* * Routine that is called when the file "auto_msgmni" has successfully been * written. * Two values are allowed: * 0: unregister msgmni's callback routine from the ipc namespace notifier * chain. This means that msgmni won't be recomputed anymore upon memory * add/remove or ipc namespace creation/removal. * 1: register back the callback routine. */ static void ipc_auto_callback(int val) { if (!val) unregister_ipcns_notifier(current->nsproxy->ipc_ns); else { /* * Re-enable automatic recomputing only if not already * enabled. */ recompute_msgmni(current->nsproxy->ipc_ns); cond_register_ipcns_notifier(current->nsproxy->ipc_ns); } } static int proc_ipcauto_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table ipc_table; size_t lenp_bef = *lenp; int oldval; int rc; memcpy(&ipc_table, table, sizeof(ipc_table)); ipc_table.data = get_ipc(table); oldval = *((int *)(ipc_table.data)); rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos); if (write && !rc && lenp_bef == *lenp) { int newval = *((int *)(ipc_table.data)); /* * The file "auto_msgmni" has correctly been set. * React by (un)registering the corresponding tunable, if the * value has changed. */ if (newval != oldval) ipc_auto_callback(newval); } return rc; } #else #define proc_ipc_doulongvec_minmax NULL #define proc_ipc_dointvec NULL #define proc_ipc_dointvec_minmax NULL #define proc_ipc_dointvec_minmax_orphans NULL #define proc_ipc_callback_dointvec_minmax NULL #define proc_ipcauto_dointvec_minmax NULL #endif static int zero; static int one = 1; static int int_max = INT_MAX; static struct ctl_table ipc_kern_table[] = { { .procname = "shmmax", .data = &init_ipc_ns.shm_ctlmax, .maxlen = sizeof(init_ipc_ns.shm_ctlmax), .mode = 0644, .proc_handler = proc_ipc_doulongvec_minmax, }, { .procname = "shmall", .data = &init_ipc_ns.shm_ctlall, .maxlen = sizeof(init_ipc_ns.shm_ctlall), .mode = 0644, .proc_handler = proc_ipc_doulongvec_minmax, }, { .procname = "shmmni", .data = &init_ipc_ns.shm_ctlmni, .maxlen = sizeof(init_ipc_ns.shm_ctlmni), .mode = 0644, .proc_handler = proc_ipc_dointvec, }, { .procname = "shm_rmid_forced", .data = &init_ipc_ns.shm_rmid_forced, .maxlen = sizeof(init_ipc_ns.shm_rmid_forced), .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax_orphans, .extra1 = &zero, .extra2 = &one, }, { .procname = "msgmax", .data = &init_ipc_ns.msg_ctlmax, .maxlen = sizeof(init_ipc_ns.msg_ctlmax), .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax, .extra1 = &zero, .extra2 = &int_max, }, { .procname = "msgmni", .data = &init_ipc_ns.msg_ctlmni, .maxlen = sizeof(init_ipc_ns.msg_ctlmni), .mode = 0644, .proc_handler = proc_ipc_callback_dointvec_minmax, .extra1 = &zero, .extra2 = &int_max, }, { .procname = "msgmnb", .data = &init_ipc_ns.msg_ctlmnb, .maxlen = sizeof(init_ipc_ns.msg_ctlmnb), .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax, .extra1 = &zero, .extra2 = &int_max, }, { .procname = "sem", .data = &init_ipc_ns.sem_ctls, .maxlen = 4*sizeof(int), .mode = 0644, .proc_handler = proc_ipc_dointvec, }, { .procname = "auto_msgmni", .data = &init_ipc_ns.auto_msgmni, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_ipcauto_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, #ifdef CONFIG_CHECKPOINT_RESTORE { .procname = "sem_next_id", .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id, .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id), .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax, .extra1 = &zero, .extra2 = &int_max, }, { .procname = "msg_next_id", .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id, .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id), .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax, .extra1 = &zero, .extra2 = &int_max, }, { .procname = "shm_next_id", .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id, .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id), .mode = 0644, .proc_handler = proc_ipc_dointvec_minmax, .extra1 = &zero, .extra2 = &int_max, }, #endif {} }; static struct ctl_table ipc_root_table[] = { { .procname = "kernel", .mode = 0555, .child = ipc_kern_table, }, {} }; static int __init ipc_sysctl_init(void) { register_sysctl_table(ipc_root_table); return 0; } device_initcall(ipc_sysctl_init);