/* *  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(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_SYSCTLstatic int proc_ipc_dointvec(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_callback_dointvec(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(&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(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(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_callback_dointvec NULL#define proc_ipcauto_dointvec_minmax NULL#endif #ifdef CONFIG_SYSCTL_SYSCALL/* The generic sysctl ipc data routine. */static int sysctl_ipc_data(ctl_table *table,		void __user *oldval, size_t __user *oldlenp,		void __user *newval, size_t newlen){	size_t len;	void *data; 	/* Get out of I don't have a variable */	if (!table->data || !table->maxlen)		return -ENOTDIR; 	data = get_ipc(table);	if (!data)		return -ENOTDIR; 	if (oldval && oldlenp) {		if (get_user(len, oldlenp))			return -EFAULT;		if (len) {			if (len > table->maxlen)				len = table->maxlen;			if (copy_to_user(oldval, data, len))				return -EFAULT;			if (put_user(len, oldlenp))				return -EFAULT;		}	} 	if (newval && newlen) {		if (newlen > table->maxlen)			newlen = table->maxlen; 		if (copy_from_user(data, newval, newlen))			return -EFAULT;	}	return 1;} static int sysctl_ipc_registered_data(ctl_table *table,		void __user *oldval, size_t __user *oldlenp,		void __user *newval, size_t newlen){	int rc; 	rc = sysctl_ipc_data(table, oldval, oldlenp, newval, newlen); 	if (newval && newlen && rc > 0)		/*		 * Tunable has successfully been changed from userland		 */		unregister_ipcns_notifier(current->nsproxy->ipc_ns); 	return rc;}#else#define sysctl_ipc_data NULL#define sysctl_ipc_registered_data NULL#endif static int zero;static int one = 1; static struct ctl_table ipc_kern_table[] = {	{		.ctl_name	= KERN_SHMMAX,		.procname	= "shmmax",		.data		= &init_ipc_ns.shm_ctlmax,		.maxlen		= sizeof (init_ipc_ns.shm_ctlmax),		.mode		= 0644,		.proc_handler	= proc_ipc_doulongvec_minmax,		.strategy	= sysctl_ipc_data,	},	{		.ctl_name	= KERN_SHMALL,		.procname	= "shmall",		.data		= &init_ipc_ns.shm_ctlall,		.maxlen		= sizeof (init_ipc_ns.shm_ctlall),		.mode		= 0644,		.proc_handler	= proc_ipc_doulongvec_minmax,		.strategy	= sysctl_ipc_data,	},	{		.ctl_name	= KERN_SHMMNI,		.procname	= "shmmni",		.data		= &init_ipc_ns.shm_ctlmni,		.maxlen		= sizeof (init_ipc_ns.shm_ctlmni),		.mode		= 0644,		.proc_handler	= proc_ipc_dointvec,		.strategy	= sysctl_ipc_data,	},	{		.ctl_name	= KERN_MSGMAX,		.procname	= "msgmax",		.data		= &init_ipc_ns.msg_ctlmax,		.maxlen		= sizeof (init_ipc_ns.msg_ctlmax),		.mode		= 0644,		.proc_handler	= proc_ipc_dointvec,		.strategy	= sysctl_ipc_data,	},	{		.ctl_name	= KERN_MSGMNI,		.procname	= "msgmni",		.data		= &init_ipc_ns.msg_ctlmni,		.maxlen		= sizeof (init_ipc_ns.msg_ctlmni),		.mode		= 0644,		.proc_handler	= proc_ipc_callback_dointvec,		.strategy	= sysctl_ipc_registered_data,	},	{		.ctl_name	= KERN_MSGMNB,		.procname	=  "msgmnb",		.data		= &init_ipc_ns.msg_ctlmnb,		.maxlen		= sizeof (init_ipc_ns.msg_ctlmnb),		.mode		= 0644,		.proc_handler	= proc_ipc_dointvec,		.strategy	= sysctl_ipc_data,	},	{		.ctl_name	= KERN_SEM,		.procname	= "sem",		.data		= &init_ipc_ns.sem_ctls,		.maxlen		= 4*sizeof (int),		.mode		= 0644,		.proc_handler	= proc_ipc_dointvec,		.strategy	= sysctl_ipc_data,	},	{		.ctl_name	= CTL_UNNUMBERED,		.procname	= "auto_msgmni",		.data		= &init_ipc_ns.auto_msgmni,		.maxlen		= sizeof(int),		.mode		= 0644,		.proc_handler	= proc_ipcauto_dointvec_minmax,		.extra1		= &zero,		.extra2		= &one,	},	{}}; static struct ctl_table ipc_root_table[] = {	{		.ctl_name	= CTL_KERN,		.procname	= "kernel",		.mode		= 0555,		.child		= ipc_kern_table,	},	{}}; static int __init ipc_sysctl_init(void){	register_sysctl_table(ipc_root_table);	return 0;} __initcall(ipc_sysctl_init);