[linux-block.git] / ipc / mq_sysctl.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 2007 IBM Corporation
 *
 *  Author: Cedric Le Goater <clg@fr.ibm.com>
 */

#include <linux/nsproxy.h>
#include <linux/ipc_namespace.h>
#include <linux/sysctl.h>

#include <linux/stat.h>
#include <linux/capability.h>
#include <linux/slab.h>
#include <linux/cred.h>

static int msg_max_limit_min = MIN_MSGMAX;
static int msg_max_limit_max = HARD_MSGMAX;

static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;

static struct ctl_table mq_sysctls[] = {
	{
		.procname	= "queues_max",
		.data		= &init_ipc_ns.mq_queues_max,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
	},
	{
		.procname	= "msg_max",
		.data		= &init_ipc_ns.mq_msg_max,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= &msg_max_limit_min,
		.extra2		= &msg_max_limit_max,
	},
	{
		.procname	= "msgsize_max",
		.data		= &init_ipc_ns.mq_msgsize_max,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= &msg_maxsize_limit_min,
		.extra2		= &msg_maxsize_limit_max,
	},
	{
		.procname	= "msg_default",
		.data		= &init_ipc_ns.mq_msg_default,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= &msg_max_limit_min,
		.extra2		= &msg_max_limit_max,
	},
	{
		.procname	= "msgsize_default",
		.data		= &init_ipc_ns.mq_msgsize_default,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= &msg_maxsize_limit_min,
		.extra2		= &msg_maxsize_limit_max,
	},
};

static struct ctl_table_set *set_lookup(struct ctl_table_root *root)
{
	return &current->nsproxy->ipc_ns->mq_set;
}

static int set_is_seen(struct ctl_table_set *set)
{
	return &current->nsproxy->ipc_ns->mq_set == set;
}

static void mq_set_ownership(struct ctl_table_header *head,
			     kuid_t *uid, kgid_t *gid)
{
	struct ipc_namespace *ns =
		container_of(head->set, struct ipc_namespace, mq_set);

	kuid_t ns_root_uid = make_kuid(ns->user_ns, 0);
	kgid_t ns_root_gid = make_kgid(ns->user_ns, 0);

	*uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID;
	*gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID;
}

static int mq_permissions(struct ctl_table_header *head, const struct ctl_table *table)
{
	int mode = table->mode;
	kuid_t ns_root_uid;
	kgid_t ns_root_gid;

	mq_set_ownership(head, &ns_root_uid, &ns_root_gid);

	if (uid_eq(current_euid(), ns_root_uid))
		mode >>= 6;

	else if (in_egroup_p(ns_root_gid))
		mode >>= 3;

	mode &= 7;

	return (mode << 6) | (mode << 3) | mode;
}

static struct ctl_table_root set_root = {
	.lookup = set_lookup,
	.permissions = mq_permissions,
	.set_ownership = mq_set_ownership,
};

bool setup_mq_sysctls(struct ipc_namespace *ns)
{
	struct ctl_table *tbl;

	setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen);

	tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
	if (tbl) {
		int i;

		for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
			if (tbl[i].data == &init_ipc_ns.mq_queues_max)
				tbl[i].data = &ns->mq_queues_max;

			else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
				tbl[i].data = &ns->mq_msg_max;

			else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
				tbl[i].data = &ns->mq_msgsize_max;

			else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
				tbl[i].data = &ns->mq_msg_default;

			else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
				tbl[i].data = &ns->mq_msgsize_default;
			else
				tbl[i].data = NULL;
		}

		ns->mq_sysctls = __register_sysctl_table(&ns->mq_set,
							 "fs/mqueue", tbl,
							 ARRAY_SIZE(mq_sysctls));
	}
	if (!ns->mq_sysctls) {
		kfree(tbl);
		retire_sysctl_set(&ns->mq_set);
		return false;
	}

	return true;
}

void retire_mq_sysctls(struct ipc_namespace *ns)
{
	const struct ctl_table *tbl;

	tbl = ns->mq_sysctls->ctl_table_arg;
	unregister_sysctl_table(ns->mq_sysctls);
	retire_sysctl_set(&ns->mq_set);
	kfree(tbl);
}
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
bdc8e5f8 SH	2	/*
	3	* Copyright (C) 2007 IBM Corporation
	4	*
	5	* Author: Cedric Le Goater <clg@fr.ibm.com>
bdc8e5f8 SH	6	*/
	7
	8	#include <linux/nsproxy.h>
	9	#include <linux/ipc_namespace.h>
	10	#include <linux/sysctl.h>
	11
dc55e35f AG	12	#include <linux/stat.h>
	13	#include <linux/capability.h>
	14	#include <linux/slab.h>
f9436a5d	15	#include <linux/cred.h>
bdc8e5f8 SH	16
bdc8e5f8 SH	17	static int msg_max_limit_min = MIN_MSGMAX;
93e6f119	18	static int msg_max_limit_max = HARD_MSGMAX;
bdc8e5f8 SH	19
bdc8e5f8 SH	20	static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
93e6f119	21	static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
bdc8e5f8	22
a5c5928b	23	static struct ctl_table mq_sysctls[] = {
bdc8e5f8 SH	24	{
	25	.procname = "queues_max",
	26	.data = &init_ipc_ns.mq_queues_max,
	27	.maxlen = sizeof(int),
	28	.mode = 0644,
dc55e35f	29	.proc_handler = proc_dointvec,
bdc8e5f8 SH	30	},
	31	{
	32	.procname = "msg_max",
	33	.data = &init_ipc_ns.mq_msg_max,
	34	.maxlen = sizeof(int),
	35	.mode = 0644,
dc55e35f	36	.proc_handler = proc_dointvec_minmax,
bdc8e5f8 SH	37	.extra1 = &msg_max_limit_min,
	38	.extra2 = &msg_max_limit_max,
	39	},
	40	{
	41	.procname = "msgsize_max",
	42	.data = &init_ipc_ns.mq_msgsize_max,
	43	.maxlen = sizeof(int),
	44	.mode = 0644,
dc55e35f	45	.proc_handler = proc_dointvec_minmax,
bdc8e5f8 SH	46	.extra1 = &msg_maxsize_limit_min,
	47	.extra2 = &msg_maxsize_limit_max,
	48	},
cef0184c KM	49	{
	50	.procname = "msg_default",
	51	.data = &init_ipc_ns.mq_msg_default,
	52	.maxlen = sizeof(int),
	53	.mode = 0644,
dc55e35f	54	.proc_handler = proc_dointvec_minmax,
cef0184c KM	55	.extra1 = &msg_max_limit_min,
	56	.extra2 = &msg_max_limit_max,
	57	},
	58	{
	59	.procname = "msgsize_default",
	60	.data = &init_ipc_ns.mq_msgsize_default,
	61	.maxlen = sizeof(int),
	62	.mode = 0644,
dc55e35f	63	.proc_handler = proc_dointvec_minmax,
cef0184c KM	64	.extra1 = &msg_maxsize_limit_min,
	65	.extra2 = &msg_maxsize_limit_max,
	66	},
bdc8e5f8 SH	67	};
bdc8e5f8 SH	68
dc55e35f AG	69	static struct ctl_table_set set_lookup(struct ctl_table_root root)
	70	{
	71	return &current->nsproxy->ipc_ns->mq_set;
	72	}
bdc8e5f8	73
dc55e35f AG	74	static int set_is_seen(struct ctl_table_set *set)
	75	{
	76	return &current->nsproxy->ipc_ns->mq_set == set;
	77	}
	78
f9436a5d	79	static void mq_set_ownership(struct ctl_table_header *head,
f9436a5d AG	80	kuid_t uid, kgid_t gid)
	81	{
	82	struct ipc_namespace *ns =
	83	container_of(head->set, struct ipc_namespace, mq_set);
	84
	85	kuid_t ns_root_uid = make_kuid(ns->user_ns, 0);
	86	kgid_t ns_root_gid = make_kgid(ns->user_ns, 0);
	87
	88	*uid = uid_valid(ns_root_uid) ? ns_root_uid : GLOBAL_ROOT_UID;
	89	*gid = gid_valid(ns_root_gid) ? ns_root_gid : GLOBAL_ROOT_GID;
	90	}
	91
795f90c6	92	static int mq_permissions(struct ctl_table_header head, const struct ctl_table table)
f9436a5d AG	93	{
	94	int mode = table->mode;
	95	kuid_t ns_root_uid;
	96	kgid_t ns_root_gid;
	97
520713a9	98	mq_set_ownership(head, &ns_root_uid, &ns_root_gid);
f9436a5d AG	99
	100	if (uid_eq(current_euid(), ns_root_uid))
	101	mode >>= 6;
	102
	103	else if (in_egroup_p(ns_root_gid))
	104	mode >>= 3;
	105
	106	mode &= 7;
	107
	108	return (mode << 6) \| (mode << 3) \| mode;
	109	}
	110
dc55e35f AG	111	static struct ctl_table_root set_root = {
dc55e35f AG	112	.lookup = set_lookup,
f9436a5d AG	113	.permissions = mq_permissions,
f9436a5d AG	114	.set_ownership = mq_set_ownership,
bdc8e5f8 SH	115	};
bdc8e5f8 SH	116
dc55e35f	117	bool setup_mq_sysctls(struct ipc_namespace *ns)
bdc8e5f8	118	{
dc55e35f AG	119	struct ctl_table *tbl;
	120
	121	setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen);
	122
	123	tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL);
	124	if (tbl) {
	125	int i;
	126
	127	for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) {
	128	if (tbl[i].data == &init_ipc_ns.mq_queues_max)
	129	tbl[i].data = &ns->mq_queues_max;
	130
	131	else if (tbl[i].data == &init_ipc_ns.mq_msg_max)
	132	tbl[i].data = &ns->mq_msg_max;
	133
	134	else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max)
	135	tbl[i].data = &ns->mq_msgsize_max;
	136
	137	else if (tbl[i].data == &init_ipc_ns.mq_msg_default)
	138	tbl[i].data = &ns->mq_msg_default;
	139
	140	else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default)
	141	tbl[i].data = &ns->mq_msgsize_default;
	142	else
	143	tbl[i].data = NULL;
	144	}
	145
bff97cf1 JG	146	ns->mq_sysctls = __register_sysctl_table(&ns->mq_set,
	147	"fs/mqueue", tbl,
	148	ARRAY_SIZE(mq_sysctls));
dc55e35f AG	149	}
	150	if (!ns->mq_sysctls) {
	151	kfree(tbl);
	152	retire_sysctl_set(&ns->mq_set);
	153	return false;
	154	}
	155
	156	return true;
	157	}
	158
	159	void retire_mq_sysctls(struct ipc_namespace *ns)
	160	{
bfa858f2	161	const struct ctl_table *tbl;
dc55e35f AG	162
	163	tbl = ns->mq_sysctls->ctl_table_arg;
	164	unregister_sysctl_table(ns->mq_sysctls);
	165	retire_sysctl_set(&ns->mq_set);
	166	kfree(tbl);
bdc8e5f8	167	}