[linux-block.git] / net / core / sock_diag.c

/* License: GPL */

#include <linux/filter.h>
#include <linux/mutex.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/net_namespace.h>
#include <linux/module.h>
#include <net/sock.h>
#include <linux/kernel.h>
#include <linux/tcp.h>
#include <linux/workqueue.h>
#include <linux/nospec.h>
#include <linux/cookie.h>
#include <linux/inet_diag.h>
#include <linux/sock_diag.h>

static const struct sock_diag_handler __rcu *sock_diag_handlers[AF_MAX];

static const struct sock_diag_inet_compat __rcu *inet_rcv_compat;

static struct workqueue_struct *broadcast_wq;

DEFINE_COOKIE(sock_cookie);

u64 __sock_gen_cookie(struct sock *sk)
{
	u64 res = atomic64_read(&sk->sk_cookie);

	if (!res) {
		u64 new = gen_cookie_next(&sock_cookie);

		atomic64_cmpxchg(&sk->sk_cookie, res, new);

		/* Another thread might have changed sk_cookie before us. */
		res = atomic64_read(&sk->sk_cookie);
	}
	return res;
}

int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
{
	u64 res;

	if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE)
		return 0;

	res = sock_gen_cookie(sk);
	if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1])
		return -ESTALE;

	return 0;
}
EXPORT_SYMBOL_GPL(sock_diag_check_cookie);

void sock_diag_save_cookie(struct sock *sk, __u32 *cookie)
{
	u64 res = sock_gen_cookie(sk);

	cookie[0] = (u32)res;
	cookie[1] = (u32)(res >> 32);
}
EXPORT_SYMBOL_GPL(sock_diag_save_cookie);

int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
{
	u32 mem[SK_MEMINFO_VARS];

	sk_get_meminfo(sk, mem);

	return nla_put(skb, attrtype, sizeof(mem), &mem);
}
EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);

int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
			     struct sk_buff *skb, int attrtype)
{
	struct sock_fprog_kern *fprog;
	struct sk_filter *filter;
	struct nlattr *attr;
	unsigned int flen;
	int err = 0;

	if (!may_report_filterinfo) {
		nla_reserve(skb, attrtype, 0);
		return 0;
	}

	rcu_read_lock();
	filter = rcu_dereference(sk->sk_filter);
	if (!filter)
		goto out;

	fprog = filter->prog->orig_prog;
	if (!fprog)
		goto out;

	flen = bpf_classic_proglen(fprog);

	attr = nla_reserve(skb, attrtype, flen);
	if (attr == NULL) {
		err = -EMSGSIZE;
		goto out;
	}

	memcpy(nla_data(attr), fprog->filter, flen);
out:
	rcu_read_unlock();
	return err;
}
EXPORT_SYMBOL(sock_diag_put_filterinfo);

struct broadcast_sk {
	struct sock *sk;
	struct work_struct work;
};

static size_t sock_diag_nlmsg_size(void)
{
	return NLMSG_ALIGN(sizeof(struct inet_diag_msg)
	       + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */
	       + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */
}

static const struct sock_diag_handler *sock_diag_lock_handler(int family)
{
	const struct sock_diag_handler *handler;

	rcu_read_lock();
	handler = rcu_dereference(sock_diag_handlers[family]);
	if (handler && !try_module_get(handler->owner))
		handler = NULL;
	rcu_read_unlock();

	return handler;
}

static void sock_diag_unlock_handler(const struct sock_diag_handler *handler)
{
	module_put(handler->owner);
}

static void sock_diag_broadcast_destroy_work(struct work_struct *work)
{
	struct broadcast_sk *bsk =
		container_of(work, struct broadcast_sk, work);
	struct sock *sk = bsk->sk;
	const struct sock_diag_handler *hndl;
	struct sk_buff *skb;
	const enum sknetlink_groups group = sock_diag_destroy_group(sk);
	int err = -1;

	WARN_ON(group == SKNLGRP_NONE);

	skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL);
	if (!skb)
		goto out;

	hndl = sock_diag_lock_handler(sk->sk_family);
	if (hndl) {
		if (hndl->get_info)
			err = hndl->get_info(skb, sk);
		sock_diag_unlock_handler(hndl);
	}
	if (!err)
		nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group,
				GFP_KERNEL);
	else
		kfree_skb(skb);
out:
	sk_destruct(sk);
	kfree(bsk);
}

void sock_diag_broadcast_destroy(struct sock *sk)
{
	/* Note, this function is often called from an interrupt context. */
	struct broadcast_sk *bsk =
		kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC);
	if (!bsk)
		return sk_destruct(sk);
	bsk->sk = sk;
	INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work);
	queue_work(broadcast_wq, &bsk->work);
}

void sock_diag_register_inet_compat(const struct sock_diag_inet_compat *ptr)
{
	xchg(&inet_rcv_compat, RCU_INITIALIZER(ptr));
}
EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);

void sock_diag_unregister_inet_compat(const struct sock_diag_inet_compat *ptr)
{
	const struct sock_diag_inet_compat *old;

	old = unrcu_pointer(xchg(&inet_rcv_compat, NULL));
	WARN_ON_ONCE(old != ptr);
}
EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);

int sock_diag_register(const struct sock_diag_handler *hndl)
{
	int family = hndl->family;

	if (family >= AF_MAX)
		return -EINVAL;

	return !cmpxchg((const struct sock_diag_handler **)
				&sock_diag_handlers[family],
			NULL, hndl) ? 0 : -EBUSY;
}
EXPORT_SYMBOL_GPL(sock_diag_register);

void sock_diag_unregister(const struct sock_diag_handler *hndl)
{
	int family = hndl->family;

	if (family >= AF_MAX)
		return;

	xchg((const struct sock_diag_handler **)&sock_diag_handlers[family],
	     NULL);
}
EXPORT_SYMBOL_GPL(sock_diag_unregister);

static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	int err;
	struct sock_diag_req *req = nlmsg_data(nlh);
	const struct sock_diag_handler *hndl;

	if (nlmsg_len(nlh) < sizeof(*req))
		return -EINVAL;

	if (req->sdiag_family >= AF_MAX)
		return -EINVAL;
	req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);

	if (!rcu_access_pointer(sock_diag_handlers[req->sdiag_family]))
		sock_load_diag_module(req->sdiag_family, 0);

	hndl = sock_diag_lock_handler(req->sdiag_family);
	if (hndl == NULL)
		return -ENOENT;

	if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
		err = hndl->dump(skb, nlh);
	else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy)
		err = hndl->destroy(skb, nlh);
	else
		err = -EOPNOTSUPP;
	sock_diag_unlock_handler(hndl);

	return err;
}

static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
			     struct netlink_ext_ack *extack)
{
	const struct sock_diag_inet_compat *ptr;
	int ret;

	switch (nlh->nlmsg_type) {
	case TCPDIAG_GETSOCK:
		if (!rcu_access_pointer(inet_rcv_compat))
			sock_load_diag_module(AF_INET, 0);

		rcu_read_lock();
		ptr = rcu_dereference(inet_rcv_compat);
		if (ptr && !try_module_get(ptr->owner))
			ptr = NULL;
		rcu_read_unlock();

		ret = -EOPNOTSUPP;
		if (ptr) {
			ret = ptr->fn(skb, nlh);
			module_put(ptr->owner);
		}

		return ret;
	case SOCK_DIAG_BY_FAMILY:
	case SOCK_DESTROY:
		return __sock_diag_cmd(skb, nlh);
	default:
		return -EINVAL;
	}
}

static void sock_diag_rcv(struct sk_buff *skb)
{
	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
}

static int sock_diag_bind(struct net *net, int group)
{
	switch (group) {
	case SKNLGRP_INET_TCP_DESTROY:
	case SKNLGRP_INET_UDP_DESTROY:
		if (!rcu_access_pointer(sock_diag_handlers[AF_INET]))
			sock_load_diag_module(AF_INET, 0);
		break;
	case SKNLGRP_INET6_TCP_DESTROY:
	case SKNLGRP_INET6_UDP_DESTROY:
		if (!rcu_access_pointer(sock_diag_handlers[AF_INET6]))
			sock_load_diag_module(AF_INET6, 0);
		break;
	}
	return 0;
}

int sock_diag_destroy(struct sock *sk, int err)
{
	if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
		return -EPERM;

	if (!sk->sk_prot->diag_destroy)
		return -EOPNOTSUPP;

	return sk->sk_prot->diag_destroy(sk, err);
}
EXPORT_SYMBOL_GPL(sock_diag_destroy);

static int __net_init diag_net_init(struct net *net)
{
	struct netlink_kernel_cfg cfg = {
		.groups	= SKNLGRP_MAX,
		.input	= sock_diag_rcv,
		.bind	= sock_diag_bind,
		.flags	= NL_CFG_F_NONROOT_RECV,
	};

	net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
	return net->diag_nlsk == NULL ? -ENOMEM : 0;
}

static void __net_exit diag_net_exit(struct net *net)
{
	netlink_kernel_release(net->diag_nlsk);
	net->diag_nlsk = NULL;
}

static struct pernet_operations diag_net_ops = {
	.init = diag_net_init,
	.exit = diag_net_exit,
};

static int __init sock_diag_init(void)
{
	broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
	BUG_ON(!broadcast_wq);
	return register_pernet_subsys(&diag_net_ops);
}
device_initcall(sock_diag_init);
Commit	Line	Data
	1	/* License: GPL */
	2
	3	#include <linux/filter.h>
	4	#include <linux/mutex.h>
	5	#include <linux/socket.h>
	6	#include <linux/skbuff.h>
	7	#include <net/netlink.h>
	8	#include <net/net_namespace.h>
	9	#include <linux/module.h>
	10	#include <net/sock.h>
	11	#include <linux/kernel.h>
	12	#include <linux/tcp.h>
	13	#include <linux/workqueue.h>
	14	#include <linux/nospec.h>
	15	#include <linux/cookie.h>
	16	#include <linux/inet_diag.h>
	17	#include <linux/sock_diag.h>
	18
	19	static const struct sock_diag_handler __rcu *sock_diag_handlers[AF_MAX];
	20
	21	static const struct sock_diag_inet_compat __rcu *inet_rcv_compat;
	22
	23	static struct workqueue_struct *broadcast_wq;
	24
	25	DEFINE_COOKIE(sock_cookie);
	26
	27	u64 __sock_gen_cookie(struct sock *sk)
	28	{
	29	u64 res = atomic64_read(&sk->sk_cookie);
	30
	31	if (!res) {
	32	u64 new = gen_cookie_next(&sock_cookie);
	33
	34	atomic64_cmpxchg(&sk->sk_cookie, res, new);
	35
	36	/* Another thread might have changed sk_cookie before us. */
	37	res = atomic64_read(&sk->sk_cookie);
	38	}
	39	return res;
	40	}
	41
	42	int sock_diag_check_cookie(struct sock sk, const __u32 cookie)
	43	{
	44	u64 res;
	45
	46	if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE)
	47	return 0;
	48
	49	res = sock_gen_cookie(sk);
	50	if ((u32)res != cookie[0] \|\| (u32)(res >> 32) != cookie[1])
	51	return -ESTALE;
	52
	53	return 0;
	54	}
	55	EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
	56
	57	void sock_diag_save_cookie(struct sock sk, __u32 cookie)
	58	{
	59	u64 res = sock_gen_cookie(sk);
	60
	61	cookie[0] = (u32)res;
	62	cookie[1] = (u32)(res >> 32);
	63	}
	64	EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
	65
	66	int sock_diag_put_meminfo(struct sock sk, struct sk_buff skb, int attrtype)
	67	{
	68	u32 mem[SK_MEMINFO_VARS];
	69
	70	sk_get_meminfo(sk, mem);
	71
	72	return nla_put(skb, attrtype, sizeof(mem), &mem);
	73	}
	74	EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
	75
	76	int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
	77	struct sk_buff *skb, int attrtype)
	78	{
	79	struct sock_fprog_kern *fprog;
	80	struct sk_filter *filter;
	81	struct nlattr *attr;
	82	unsigned int flen;
	83	int err = 0;
	84
	85	if (!may_report_filterinfo) {
	86	nla_reserve(skb, attrtype, 0);
	87	return 0;
	88	}
	89
	90	rcu_read_lock();
	91	filter = rcu_dereference(sk->sk_filter);
	92	if (!filter)
	93	goto out;
	94
	95	fprog = filter->prog->orig_prog;
	96	if (!fprog)
	97	goto out;
	98
	99	flen = bpf_classic_proglen(fprog);
	100
	101	attr = nla_reserve(skb, attrtype, flen);
	102	if (attr == NULL) {
	103	err = -EMSGSIZE;
	104	goto out;
	105	}
	106
	107	memcpy(nla_data(attr), fprog->filter, flen);
	108	out:
	109	rcu_read_unlock();
	110	return err;
	111	}
	112	EXPORT_SYMBOL(sock_diag_put_filterinfo);
	113
	114	struct broadcast_sk {
	115	struct sock *sk;
	116	struct work_struct work;
	117	};
	118
	119	static size_t sock_diag_nlmsg_size(void)
	120	{
	121	return NLMSG_ALIGN(sizeof(struct inet_diag_msg)
	122	+ nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */
	123	+ nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */
	124	}
	125
	126	static const struct sock_diag_handler *sock_diag_lock_handler(int family)
	127	{
	128	const struct sock_diag_handler *handler;
	129
	130	rcu_read_lock();
	131	handler = rcu_dereference(sock_diag_handlers[family]);
	132	if (handler && !try_module_get(handler->owner))
	133	handler = NULL;
	134	rcu_read_unlock();
	135
	136	return handler;
	137	}
	138
	139	static void sock_diag_unlock_handler(const struct sock_diag_handler *handler)
	140	{
	141	module_put(handler->owner);
	142	}
	143
	144	static void sock_diag_broadcast_destroy_work(struct work_struct *work)
	145	{
	146	struct broadcast_sk *bsk =
	147	container_of(work, struct broadcast_sk, work);
	148	struct sock *sk = bsk->sk;
	149	const struct sock_diag_handler *hndl;
	150	struct sk_buff *skb;
	151	const enum sknetlink_groups group = sock_diag_destroy_group(sk);
	152	int err = -1;
	153
	154	WARN_ON(group == SKNLGRP_NONE);
	155
	156	skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL);
	157	if (!skb)
	158	goto out;
	159
	160	hndl = sock_diag_lock_handler(sk->sk_family);
	161	if (hndl) {
	162	if (hndl->get_info)
	163	err = hndl->get_info(skb, sk);
	164	sock_diag_unlock_handler(hndl);
	165	}
	166	if (!err)
	167	nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group,
	168	GFP_KERNEL);
	169	else
	170	kfree_skb(skb);
	171	out:
	172	sk_destruct(sk);
	173	kfree(bsk);
	174	}
	175
	176	void sock_diag_broadcast_destroy(struct sock *sk)
	177	{
	178	/* Note, this function is often called from an interrupt context. */
	179	struct broadcast_sk *bsk =
	180	kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC);
	181	if (!bsk)
	182	return sk_destruct(sk);
	183	bsk->sk = sk;
	184	INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work);
	185	queue_work(broadcast_wq, &bsk->work);
	186	}
	187
	188	void sock_diag_register_inet_compat(const struct sock_diag_inet_compat *ptr)
	189	{
	190	xchg(&inet_rcv_compat, RCU_INITIALIZER(ptr));
	191	}
	192	EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
	193
	194	void sock_diag_unregister_inet_compat(const struct sock_diag_inet_compat *ptr)
	195	{
	196	const struct sock_diag_inet_compat *old;
	197
	198	old = unrcu_pointer(xchg(&inet_rcv_compat, NULL));
	199	WARN_ON_ONCE(old != ptr);
	200	}
	201	EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
	202
	203	int sock_diag_register(const struct sock_diag_handler *hndl)
	204	{
	205	int family = hndl->family;
	206
	207	if (family >= AF_MAX)
	208	return -EINVAL;
	209
	210	return !cmpxchg((const struct sock_diag_handler **)
	211	&sock_diag_handlers[family],
	212	NULL, hndl) ? 0 : -EBUSY;
	213	}
	214	EXPORT_SYMBOL_GPL(sock_diag_register);
	215
	216	void sock_diag_unregister(const struct sock_diag_handler *hndl)
	217	{
	218	int family = hndl->family;
	219
	220	if (family >= AF_MAX)
	221	return;
	222
	223	xchg((const struct sock_diag_handler **)&sock_diag_handlers[family],
	224	NULL);
	225	}
	226	EXPORT_SYMBOL_GPL(sock_diag_unregister);
	227
	228	static int __sock_diag_cmd(struct sk_buff skb, struct nlmsghdr nlh)
	229	{
	230	int err;
	231	struct sock_diag_req *req = nlmsg_data(nlh);
	232	const struct sock_diag_handler *hndl;
	233
	234	if (nlmsg_len(nlh) < sizeof(*req))
	235	return -EINVAL;
	236
	237	if (req->sdiag_family >= AF_MAX)
	238	return -EINVAL;
	239	req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);
	240
	241	if (!rcu_access_pointer(sock_diag_handlers[req->sdiag_family]))
	242	sock_load_diag_module(req->sdiag_family, 0);
	243
	244	hndl = sock_diag_lock_handler(req->sdiag_family);
	245	if (hndl == NULL)
	246	return -ENOENT;
	247
	248	if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
	249	err = hndl->dump(skb, nlh);
	250	else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy)
	251	err = hndl->destroy(skb, nlh);
	252	else
	253	err = -EOPNOTSUPP;
	254	sock_diag_unlock_handler(hndl);
	255
	256	return err;
	257	}
	258
	259	static int sock_diag_rcv_msg(struct sk_buff skb, struct nlmsghdr nlh,
	260	struct netlink_ext_ack *extack)
	261	{
	262	const struct sock_diag_inet_compat *ptr;
	263	int ret;
	264
	265	switch (nlh->nlmsg_type) {
	266	case TCPDIAG_GETSOCK:
	267	if (!rcu_access_pointer(inet_rcv_compat))
	268	sock_load_diag_module(AF_INET, 0);
	269
	270	rcu_read_lock();
	271	ptr = rcu_dereference(inet_rcv_compat);
	272	if (ptr && !try_module_get(ptr->owner))
	273	ptr = NULL;
	274	rcu_read_unlock();
	275
	276	ret = -EOPNOTSUPP;
	277	if (ptr) {
	278	ret = ptr->fn(skb, nlh);
	279	module_put(ptr->owner);
	280	}
	281
	282	return ret;
	283	case SOCK_DIAG_BY_FAMILY:
	284	case SOCK_DESTROY:
	285	return __sock_diag_cmd(skb, nlh);
	286	default:
	287	return -EINVAL;
	288	}
	289	}
	290
	291	static void sock_diag_rcv(struct sk_buff *skb)
	292	{
	293	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
	294	}
	295
	296	static int sock_diag_bind(struct net *net, int group)
	297	{
	298	switch (group) {
	299	case SKNLGRP_INET_TCP_DESTROY:
	300	case SKNLGRP_INET_UDP_DESTROY:
	301	if (!rcu_access_pointer(sock_diag_handlers[AF_INET]))
	302	sock_load_diag_module(AF_INET, 0);
	303	break;
	304	case SKNLGRP_INET6_TCP_DESTROY:
	305	case SKNLGRP_INET6_UDP_DESTROY:
	306	if (!rcu_access_pointer(sock_diag_handlers[AF_INET6]))
	307	sock_load_diag_module(AF_INET6, 0);
	308	break;
	309	}
	310	return 0;
	311	}
	312
	313	int sock_diag_destroy(struct sock *sk, int err)
	314	{
	315	if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
	316	return -EPERM;
	317
	318	if (!sk->sk_prot->diag_destroy)
	319	return -EOPNOTSUPP;
	320
	321	return sk->sk_prot->diag_destroy(sk, err);
	322	}
	323	EXPORT_SYMBOL_GPL(sock_diag_destroy);
	324
	325	static int __net_init diag_net_init(struct net *net)
	326	{
	327	struct netlink_kernel_cfg cfg = {
	328	.groups = SKNLGRP_MAX,
	329	.input = sock_diag_rcv,
	330	.bind = sock_diag_bind,
	331	.flags = NL_CFG_F_NONROOT_RECV,
	332	};
	333
	334	net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
	335	return net->diag_nlsk == NULL ? -ENOMEM : 0;
	336	}
	337
	338	static void __net_exit diag_net_exit(struct net *net)
	339	{
	340	netlink_kernel_release(net->diag_nlsk);
	341	net->diag_nlsk = NULL;
	342	}
	343
	344	static struct pernet_operations diag_net_ops = {
	345	.init = diag_net_init,
	346	.exit = diag_net_exit,
	347	};
	348
	349	static int __init sock_diag_init(void)
	350	{
	351	broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
	352	BUG_ON(!broadcast_wq);
	353	return register_pernet_subsys(&diag_net_ops);
	354	}
	355	device_initcall(sock_diag_init);