示例#1
0
int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
		      struct sk_buff *skb, const struct inet_diag_req_v2 *req,
		      struct user_namespace *user_ns,
		      u32 portid, u32 seq, u16 nlmsg_flags,
		      const struct nlmsghdr *unlh)
{
	const struct inet_sock *inet = inet_sk(sk);
	const struct tcp_congestion_ops *ca_ops;
	const struct inet_diag_handler *handler;
	int ext = req->idiag_ext;
	struct inet_diag_msg *r;
	struct nlmsghdr  *nlh;
	struct nlattr *attr;
	void *info = NULL;

	handler = inet_diag_table[req->sdiag_protocol];
	BUG_ON(!handler);

	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
			nlmsg_flags);
	if (!nlh)
		return -EMSGSIZE;

	r = nlmsg_data(nlh);
	BUG_ON(!sk_fullsock(sk));

	inet_diag_msg_common_fill(r, sk);
	r->idiag_state = sk->sk_state;
	r->idiag_timer = 0;
	r->idiag_retrans = 0;

	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
		goto errout;

	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
	 * hence this needs to be included regardless of socket family.
	 */
	if (ext & (1 << (INET_DIAG_TOS - 1)))
		if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
			goto errout;

#if IS_ENABLED(CONFIG_IPV6)
	if (r->idiag_family == AF_INET6) {
		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
			if (nla_put_u8(skb, INET_DIAG_TCLASS,
				       inet6_sk(sk)->tclass) < 0)
				goto errout;

		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
			goto errout;
	}
#endif

	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
	r->idiag_inode = sock_i_ino(sk);

	if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
		struct inet_diag_meminfo minfo = {
			.idiag_rmem = sk_rmem_alloc_get(sk),
			.idiag_wmem = sk->sk_wmem_queued,
			.idiag_fmem = sk->sk_forward_alloc,
			.idiag_tmem = sk_wmem_alloc_get(sk),
		};

		if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0)
			goto errout;
	}

	if (ext & (1 << (INET_DIAG_SKMEMINFO - 1)))
		if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
			goto errout;

	if (!icsk) {
		handler->idiag_get_info(sk, r, NULL);
		goto out;
	}

#define EXPIRES_IN_MS(tmo)  DIV_ROUND_UP((tmo - jiffies) * 1000, HZ)

	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
	    icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
		r->idiag_timer = 1;
		r->idiag_retrans = icsk->icsk_retransmits;
		r->idiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
		r->idiag_timer = 4;
		r->idiag_retrans = icsk->icsk_probes_out;
		r->idiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
	} else if (timer_pending(&sk->sk_timer)) {
		r->idiag_timer = 2;
		r->idiag_retrans = icsk->icsk_probes_out;
		r->idiag_expires = EXPIRES_IN_MS(sk->sk_timer.expires);
	} else {
		r->idiag_timer = 0;
		r->idiag_expires = 0;
	}
#undef EXPIRES_IN_MS

	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
		attr = nla_reserve(skb, INET_DIAG_INFO,
				   handler->idiag_info_size);
		if (!attr)
			goto errout;

		info = nla_data(attr);
	}

	if (ext & (1 << (INET_DIAG_CONG - 1))) {
		int err = 0;

		rcu_read_lock();
		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
		if (ca_ops)
			err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name);
		rcu_read_unlock();
		if (err < 0)
			goto errout;
	}

	handler->idiag_get_info(sk, r, info);

	if (sk->sk_state < TCP_TIME_WAIT) {
		union tcp_cc_info info;
		size_t sz = 0;
		int attr;

		rcu_read_lock();
		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
		if (ca_ops && ca_ops->get_info)
			sz = ca_ops->get_info(sk, ext, &attr, &info);
		rcu_read_unlock();
		if (sz && nla_put(skb, attr, sz, &info) < 0)
			goto errout;
	}

out:
	nlmsg_end(skb, nlh);
	return 0;

errout:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}
EXPORT_SYMBOL_GPL(inet_sk_diag_fill);

static int inet_csk_diag_fill(struct sock *sk,
			      struct sk_buff *skb,
			      const struct inet_diag_req_v2 *req,
			      struct user_namespace *user_ns,
			      u32 portid, u32 seq, u16 nlmsg_flags,
			      const struct nlmsghdr *unlh)
{
	return inet_sk_diag_fill(sk, inet_csk(sk), skb, req,
				 user_ns, portid, seq, nlmsg_flags, unlh);
}

static int inet_twsk_diag_fill(struct sock *sk,
			       struct sk_buff *skb,
			       u32 portid, u32 seq, u16 nlmsg_flags,
			       const struct nlmsghdr *unlh)
{
	struct inet_timewait_sock *tw = inet_twsk(sk);
	struct inet_diag_msg *r;
	struct nlmsghdr *nlh;
	long tmo;

	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
			nlmsg_flags);
	if (!nlh)
		return -EMSGSIZE;

	r = nlmsg_data(nlh);
	BUG_ON(tw->tw_state != TCP_TIME_WAIT);

	tmo = tw->tw_timer.expires - jiffies;
	if (tmo < 0)
		tmo = 0;

	inet_diag_msg_common_fill(r, sk);
	r->idiag_retrans      = 0;

	r->idiag_state	      = tw->tw_substate;
	r->idiag_timer	      = 3;
	r->idiag_expires      = jiffies_to_msecs(tmo);
	r->idiag_rqueue	      = 0;
	r->idiag_wqueue	      = 0;
	r->idiag_uid	      = 0;
	r->idiag_inode	      = 0;

	nlmsg_end(skb, nlh);
	return 0;
}

static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
			      u32 portid, u32 seq, u16 nlmsg_flags,
			      const struct nlmsghdr *unlh)
{
	struct inet_diag_msg *r;
	struct nlmsghdr *nlh;
	long tmo;

	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
			nlmsg_flags);
	if (!nlh)
		return -EMSGSIZE;

	r = nlmsg_data(nlh);
	inet_diag_msg_common_fill(r, sk);
	r->idiag_state = TCP_SYN_RECV;
	r->idiag_timer = 1;
	r->idiag_retrans = inet_reqsk(sk)->num_retrans;

	BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
		     offsetof(struct sock, sk_cookie));

	tmo = inet_reqsk(sk)->rsk_timer.expires - jiffies;
	r->idiag_expires = (tmo >= 0) ? jiffies_to_msecs(tmo) : 0;
	r->idiag_rqueue	= 0;
	r->idiag_wqueue	= 0;
	r->idiag_uid	= 0;
	r->idiag_inode	= 0;

	nlmsg_end(skb, nlh);
	return 0;
}

static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
			const struct inet_diag_req_v2 *r,
			struct user_namespace *user_ns,
			u32 portid, u32 seq, u16 nlmsg_flags,
			const struct nlmsghdr *unlh)
{
	if (sk->sk_state == TCP_TIME_WAIT)
		return inet_twsk_diag_fill(sk, skb, portid, seq,
					   nlmsg_flags, unlh);

	if (sk->sk_state == TCP_NEW_SYN_RECV)
		return inet_req_diag_fill(sk, skb, portid, seq,
					  nlmsg_flags, unlh);

	return inet_csk_diag_fill(sk, skb, r, user_ns, portid, seq,
				  nlmsg_flags, unlh);
}

struct sock *inet_diag_find_one_icsk(struct net *net,
				     struct inet_hashinfo *hashinfo,
				     const struct inet_diag_req_v2 *req)
{
	struct sock *sk;

	if (req->sdiag_family == AF_INET)
		sk = inet_lookup(net, hashinfo, req->id.idiag_dst[0],
				 req->id.idiag_dport, req->id.idiag_src[0],
				 req->id.idiag_sport, req->id.idiag_if);
#if IS_ENABLED(CONFIG_IPV6)
	else if (req->sdiag_family == AF_INET6) {
		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
			sk = inet_lookup(net, hashinfo, req->id.idiag_dst[3],
					 req->id.idiag_dport, req->id.idiag_src[3],
					 req->id.idiag_sport, req->id.idiag_if);
		else
			sk = inet6_lookup(net, hashinfo,
					  (struct in6_addr *)req->id.idiag_dst,
					  req->id.idiag_dport,
					  (struct in6_addr *)req->id.idiag_src,
					  req->id.idiag_sport,
					  req->id.idiag_if);
	}
#endif
	else
		return ERR_PTR(-EINVAL);

	if (!sk)
		return ERR_PTR(-ENOENT);

	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
		sock_gen_put(sk);
		return ERR_PTR(-ENOENT);
	}

	return sk;
}
EXPORT_SYMBOL_GPL(inet_diag_find_one_icsk);

int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
			    struct sk_buff *in_skb,
			    const struct nlmsghdr *nlh,
			    const struct inet_diag_req_v2 *req)
{
	struct net *net = sock_net(in_skb->sk);
	struct sk_buff *rep;
	struct sock *sk;
	int err;

	sk = inet_diag_find_one_icsk(net, hashinfo, req);
	if (IS_ERR(sk))
		return PTR_ERR(sk);

	rep = nlmsg_new(inet_sk_attr_size(), GFP_KERNEL);
	if (!rep) {
		err = -ENOMEM;
		goto out;
	}

	err = sk_diag_fill(sk, rep, req,
			   sk_user_ns(NETLINK_CB(in_skb).sk),
			   NETLINK_CB(in_skb).portid,
			   nlh->nlmsg_seq, 0, nlh);
	if (err < 0) {
		WARN_ON(err == -EMSGSIZE);
		nlmsg_free(rep);
		goto out;
	}
	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
			      MSG_DONTWAIT);
	if (err > 0)
		err = 0;

out:
	if (sk)
		sock_gen_put(sk);

	return err;
}
EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk);

static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb,
			       const struct nlmsghdr *nlh,
			       const struct inet_diag_req_v2 *req)
{
	const struct inet_diag_handler *handler;
	int err;

	handler = inet_diag_lock_handler(req->sdiag_protocol);
	if (IS_ERR(handler))
		err = PTR_ERR(handler);
	else if (cmd == SOCK_DIAG_BY_FAMILY)
		err = handler->dump_one(in_skb, nlh, req);
	else if (cmd == SOCK_DESTROY_BACKPORT && handler->destroy)
		err = handler->destroy(in_skb, req);
	else
		err = -EOPNOTSUPP;
	inet_diag_unlock_handler(handler);

	return err;
}

static int bitstring_match(const __be32 *a1, const __be32 *a2, int bits)
{
	int words = bits >> 5;

	bits &= 0x1f;

	if (words) {
		if (memcmp(a1, a2, words << 2))
			return 0;
	}
	if (bits) {
		__be32 w1, w2;
		__be32 mask;

		w1 = a1[words];
		w2 = a2[words];

		mask = htonl((0xffffffff) << (32 - bits));

		if ((w1 ^ w2) & mask)
			return 0;
	}

	return 1;
}
示例#2
0
int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
		      struct sk_buff *skb, const struct inet_diag_req_v2 *req,
		      struct user_namespace *user_ns,
		      u32 portid, u32 seq, u16 nlmsg_flags,
		      const struct nlmsghdr *unlh,
		      bool net_admin)
{
	const struct tcp_congestion_ops *ca_ops;
	const struct inet_diag_handler *handler;
	int ext = req->idiag_ext;
	struct inet_diag_msg *r;
	struct nlmsghdr  *nlh;
	struct nlattr *attr;
	void *info = NULL;

	handler = inet_diag_table[req->sdiag_protocol];
	BUG_ON(!handler);

	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
			nlmsg_flags);
	if (!nlh)
		return -EMSGSIZE;

	r = nlmsg_data(nlh);
	BUG_ON(!sk_fullsock(sk));

	inet_diag_msg_common_fill(r, sk);
	r->idiag_state = sk->sk_state;
	r->idiag_timer = 0;
	r->idiag_retrans = 0;

	if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
		goto errout;

	if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
		struct inet_diag_meminfo minfo = {
			.idiag_rmem = sk_rmem_alloc_get(sk),
			.idiag_wmem = sk->sk_wmem_queued,
			.idiag_fmem = sk->sk_forward_alloc,
			.idiag_tmem = sk_wmem_alloc_get(sk),
		};

		if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0)
			goto errout;
	}

	if (ext & (1 << (INET_DIAG_SKMEMINFO - 1)))
		if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
			goto errout;

	/*
	 * RAW sockets might have user-defined protocols assigned,
	 * so report the one supplied on socket creation.
	 */
	if (sk->sk_type == SOCK_RAW) {
		if (nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))
			goto errout;
	}

	if (!icsk) {
		handler->idiag_get_info(sk, r, NULL);
		goto out;
	}

	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
	    icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
		r->idiag_timer = 1;
		r->idiag_retrans = icsk->icsk_retransmits;
		r->idiag_expires =
			jiffies_to_msecs(icsk->icsk_timeout - jiffies);
	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
		r->idiag_timer = 4;
		r->idiag_retrans = icsk->icsk_probes_out;
		r->idiag_expires =
			jiffies_to_msecs(icsk->icsk_timeout - jiffies);
	} else if (timer_pending(&sk->sk_timer)) {
		r->idiag_timer = 2;
		r->idiag_retrans = icsk->icsk_probes_out;
		r->idiag_expires =
			jiffies_to_msecs(sk->sk_timer.expires - jiffies);
	} else {
		r->idiag_timer = 0;
		r->idiag_expires = 0;
	}

	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
		attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
					 handler->idiag_info_size,
					 INET_DIAG_PAD);
		if (!attr)
			goto errout;

		info = nla_data(attr);
	}

	if (ext & (1 << (INET_DIAG_CONG - 1))) {
		int err = 0;

		rcu_read_lock();
		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
		if (ca_ops)
			err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name);
		rcu_read_unlock();
		if (err < 0)
			goto errout;
	}

	handler->idiag_get_info(sk, r, info);

	if (ext & (1 << (INET_DIAG_INFO - 1)) && handler->idiag_get_aux)
		if (handler->idiag_get_aux(sk, net_admin, skb) < 0)
			goto errout;

	if (sk->sk_state < TCP_TIME_WAIT) {
		union tcp_cc_info info;
		size_t sz = 0;
		int attr;

		rcu_read_lock();
		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
		if (ca_ops && ca_ops->get_info)
			sz = ca_ops->get_info(sk, ext, &attr, &info);
		rcu_read_unlock();
		if (sz && nla_put(skb, attr, sz, &info) < 0)
			goto errout;
	}

	if (ext & (1 << (INET_DIAG_CLASS_ID - 1))) {
		u32 classid = 0;

#ifdef CONFIG_SOCK_CGROUP_DATA
		classid = sock_cgroup_classid(&sk->sk_cgrp_data);
#endif

		if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid))
			goto errout;
	}

out:
	nlmsg_end(skb, nlh);
	return 0;

errout:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}
EXPORT_SYMBOL_GPL(inet_sk_diag_fill);

static int inet_csk_diag_fill(struct sock *sk,
			      struct sk_buff *skb,
			      const struct inet_diag_req_v2 *req,
			      struct user_namespace *user_ns,
			      u32 portid, u32 seq, u16 nlmsg_flags,
			      const struct nlmsghdr *unlh,
			      bool net_admin)
{
	return inet_sk_diag_fill(sk, inet_csk(sk), skb, req, user_ns,
				 portid, seq, nlmsg_flags, unlh, net_admin);
}

static int inet_twsk_diag_fill(struct sock *sk,
			       struct sk_buff *skb,
			       u32 portid, u32 seq, u16 nlmsg_flags,
			       const struct nlmsghdr *unlh)
{
	struct inet_timewait_sock *tw = inet_twsk(sk);
	struct inet_diag_msg *r;
	struct nlmsghdr *nlh;
	long tmo;

	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
			nlmsg_flags);
	if (!nlh)
		return -EMSGSIZE;

	r = nlmsg_data(nlh);
	BUG_ON(tw->tw_state != TCP_TIME_WAIT);

	tmo = tw->tw_timer.expires - jiffies;
	if (tmo < 0)
		tmo = 0;

	inet_diag_msg_common_fill(r, sk);
	r->idiag_retrans      = 0;

	r->idiag_state	      = tw->tw_substate;
	r->idiag_timer	      = 3;
	r->idiag_expires      = jiffies_to_msecs(tmo);
	r->idiag_rqueue	      = 0;
	r->idiag_wqueue	      = 0;
	r->idiag_uid	      = 0;
	r->idiag_inode	      = 0;

	nlmsg_end(skb, nlh);
	return 0;
}

static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
			      u32 portid, u32 seq, u16 nlmsg_flags,
			      const struct nlmsghdr *unlh, bool net_admin)
{
	struct request_sock *reqsk = inet_reqsk(sk);
	struct inet_diag_msg *r;
	struct nlmsghdr *nlh;
	long tmo;

	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
			nlmsg_flags);
	if (!nlh)
		return -EMSGSIZE;

	r = nlmsg_data(nlh);
	inet_diag_msg_common_fill(r, sk);
	r->idiag_state = TCP_SYN_RECV;
	r->idiag_timer = 1;
	r->idiag_retrans = reqsk->num_retrans;

	BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
		     offsetof(struct sock, sk_cookie));

	tmo = inet_reqsk(sk)->rsk_timer.expires - jiffies;
	r->idiag_expires = (tmo >= 0) ? jiffies_to_msecs(tmo) : 0;
	r->idiag_rqueue	= 0;
	r->idiag_wqueue	= 0;
	r->idiag_uid	= 0;
	r->idiag_inode	= 0;

	if (net_admin && nla_put_u32(skb, INET_DIAG_MARK,
				     inet_rsk(reqsk)->ir_mark))
		return -EMSGSIZE;

	nlmsg_end(skb, nlh);
	return 0;
}

static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
			const struct inet_diag_req_v2 *r,
			struct user_namespace *user_ns,
			u32 portid, u32 seq, u16 nlmsg_flags,
			const struct nlmsghdr *unlh, bool net_admin)
{
	if (sk->sk_state == TCP_TIME_WAIT)
		return inet_twsk_diag_fill(sk, skb, portid, seq,
					   nlmsg_flags, unlh);

	if (sk->sk_state == TCP_NEW_SYN_RECV)
		return inet_req_diag_fill(sk, skb, portid, seq,
					  nlmsg_flags, unlh, net_admin);

	return inet_csk_diag_fill(sk, skb, r, user_ns, portid, seq,
				  nlmsg_flags, unlh, net_admin);
}

struct sock *inet_diag_find_one_icsk(struct net *net,
				     struct inet_hashinfo *hashinfo,
				     const struct inet_diag_req_v2 *req)
{
	struct sock *sk;

	rcu_read_lock();
	if (req->sdiag_family == AF_INET)
		sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[0],
				 req->id.idiag_dport, req->id.idiag_src[0],
				 req->id.idiag_sport, req->id.idiag_if);
#if IS_ENABLED(CONFIG_IPV6)
	else if (req->sdiag_family == AF_INET6) {
		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
			sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[3],
					 req->id.idiag_dport, req->id.idiag_src[3],
					 req->id.idiag_sport, req->id.idiag_if);
		else
			sk = inet6_lookup(net, hashinfo, NULL, 0,
					  (struct in6_addr *)req->id.idiag_dst,
					  req->id.idiag_dport,
					  (struct in6_addr *)req->id.idiag_src,
					  req->id.idiag_sport,
					  req->id.idiag_if);
	}
#endif
	else {
		rcu_read_unlock();
		return ERR_PTR(-EINVAL);
	}
	rcu_read_unlock();
	if (!sk)
		return ERR_PTR(-ENOENT);

	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
		sock_gen_put(sk);
		return ERR_PTR(-ENOENT);
	}

	return sk;
}
EXPORT_SYMBOL_GPL(inet_diag_find_one_icsk);

int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
			    struct sk_buff *in_skb,
			    const struct nlmsghdr *nlh,
			    const struct inet_diag_req_v2 *req)
{
	bool net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN);
	struct net *net = sock_net(in_skb->sk);
	struct sk_buff *rep;
	struct sock *sk;
	int err;

	sk = inet_diag_find_one_icsk(net, hashinfo, req);
	if (IS_ERR(sk))
		return PTR_ERR(sk);

	rep = nlmsg_new(inet_sk_attr_size(sk, req, net_admin), GFP_KERNEL);
	if (!rep) {
		err = -ENOMEM;
		goto out;
	}

	err = sk_diag_fill(sk, rep, req,
			   sk_user_ns(NETLINK_CB(in_skb).sk),
			   NETLINK_CB(in_skb).portid,
			   nlh->nlmsg_seq, 0, nlh, net_admin);
	if (err < 0) {
		WARN_ON(err == -EMSGSIZE);
		nlmsg_free(rep);
		goto out;
	}
	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
			      MSG_DONTWAIT);
	if (err > 0)
		err = 0;

out:
	if (sk)
		sock_gen_put(sk);

	return err;
}