net/sctp/diag.c - SHIFTPHONES/kernel/common - Gitiles

 // SPDX-License-Identifier: GPL-2.0-or-later
 /* SCTP kernel implementation
  * (C) Copyright Red Hat Inc. 2017
  *
  * This file is part of the SCTP kernel implementation
  *
  * These functions implement sctp diag support.
  *
  * Please send any bug reports or fixes you make to the
  * email addresched(es):
  *    lksctp developers <linux-sctp@vger.kernel.org>
  *
  * Written or modified by:
  *    Xin Long <lucien.xin@gmail.com>
  */

 #include <linux/module.h>
 #include <linux/inet_diag.h>
 #include <linux/sock_diag.h>
 #include <net/sctp/sctp.h>

 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 			       void *info);

 /* define some functions to make asoc/ep fill look clean */
 static void inet_diag_msg_sctpasoc_fill(struct inet_diag_msg *r,
 					struct sock *sk,
 					struct sctp_association *asoc)
 {
 	union sctp_addr laddr, paddr;
 	struct dst_entry *dst;
 	struct timer_list *t3_rtx = &asoc->peer.primary_path->T3_rtx_timer;

 	laddr = list_entry(asoc->base.bind_addr.address_list.next,
 			   struct sctp_sockaddr_entry, list)->a;
 	paddr = asoc->peer.primary_path->ipaddr;
 	dst = asoc->peer.primary_path->dst;

 	r->idiag_family = sk->sk_family;
 	r->id.idiag_sport = htons(asoc->base.bind_addr.port);
 	r->id.idiag_dport = htons(asoc->peer.port);
 	r->id.idiag_if = dst ? dst->dev->ifindex : 0;
 	sock_diag_save_cookie(sk, r->id.idiag_cookie);

 #if IS_ENABLED(CONFIG_IPV6)
 	if (sk->sk_family == AF_INET6) {
 		*(struct in6_addr *)r->id.idiag_src = laddr.v6.sin6_addr;
 		*(struct in6_addr *)r->id.idiag_dst = paddr.v6.sin6_addr;
 	} else
 #endif
 	{
 		memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
 		memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));

 		r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr;
 		r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr;
 	}

 	r->idiag_state = asoc->state;
 	if (timer_pending(t3_rtx)) {
 		r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX;
 		r->idiag_retrans = asoc->rtx_data_chunks;
 		r->idiag_expires = jiffies_to_msecs(t3_rtx->expires - jiffies);
 	} else {
 		r->idiag_timer = 0;
 		r->idiag_retrans = 0;
 		r->idiag_expires = 0;
 	}
 }

 static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb,
 					 struct list_head *address_list)
 {
 	struct sctp_sockaddr_entry *laddr;
 	int addrlen = sizeof(struct sockaddr_storage);
 	int addrcnt = 0;
 	struct nlattr *attr;
 	void *info = NULL;

 	list_for_each_entry_rcu(laddr, address_list, list)
 		addrcnt++;

 	attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
 	if (!attr)
 		return -EMSGSIZE;

 	info = nla_data(attr);
 	list_for_each_entry_rcu(laddr, address_list, list) {
 		memcpy(info, &laddr->a, sizeof(laddr->a));
 		memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
 		info += addrlen;
 	}

 	return 0;
 }

 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
 					struct sctp_association *asoc)
 {
 	int addrlen = sizeof(struct sockaddr_storage);
 	struct sctp_transport *from;
 	struct nlattr *attr;
 	void *info = NULL;

 	attr = nla_reserve(skb, INET_DIAG_PEERS,
 			   addrlen * asoc->peer.transport_count);
 	if (!attr)
 		return -EMSGSIZE;

 	info = nla_data(attr);
 	list_for_each_entry(from, &asoc->peer.transport_addr_list,
 			    transports) {
 		memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
 		memset(info + sizeof(from->ipaddr), 0,
 		       addrlen - sizeof(from->ipaddr));
 		info += addrlen;
 	}

 	return 0;
 }

 /* sctp asoc/ep fill*/
 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
 			       struct sk_buff *skb,
 			       const struct inet_diag_req_v2 *req,
 			       struct user_namespace *user_ns,
 			       int portid, u32 seq, u16 nlmsg_flags,
 			       const struct nlmsghdr *unlh,
 			       bool net_admin)
 {
 	struct sctp_endpoint *ep = sctp_sk(sk)->ep;
 	struct list_head *addr_list;
 	struct inet_diag_msg *r;
 	struct nlmsghdr  *nlh;
 	int ext = req->idiag_ext;
 	struct sctp_infox infox;
 	void *info = NULL;

 	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));

 	if (asoc) {
 		inet_diag_msg_sctpasoc_fill(r, sk, asoc);
 	} else {
 		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_SKMEMINFO - 1))) {
 		u32 mem[SK_MEMINFO_VARS];
 		int amt;

 		if (asoc && asoc->ep->sndbuf_policy)
 			amt = asoc->sndbuf_used;
 		else
 			amt = sk_wmem_alloc_get(sk);
 		mem[SK_MEMINFO_WMEM_ALLOC] = amt;
 		if (asoc && asoc->ep->rcvbuf_policy)
 			amt = atomic_read(&asoc->rmem_alloc);
 		else
 			amt = sk_rmem_alloc_get(sk);
 		mem[SK_MEMINFO_RMEM_ALLOC] = amt;
 		mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
 		mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
 		mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
 		mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
 		mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
 		mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
 		mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);

 		if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
 			goto errout;
 	}

 	if (ext & (1 << (INET_DIAG_INFO - 1))) {
 		struct nlattr *attr;

 		attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
 					 sizeof(struct sctp_info),
 					 INET_DIAG_PAD);
 		if (!attr)
 			goto errout;

 		info = nla_data(attr);
 	}
 	infox.sctpinfo = (struct sctp_info *)info;
 	infox.asoc = asoc;
 	sctp_diag_get_info(sk, r, &infox);

 	addr_list = asoc ? &asoc->base.bind_addr.address_list
 			 : &ep->base.bind_addr.address_list;
 	if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
 		goto errout;

 	if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
 		if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
 			goto errout;

 	if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
 		goto errout;

 	nlmsg_end(skb, nlh);
 	return 0;

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

 /* callback and param */
 struct sctp_comm_param {
 	struct sk_buff *skb;
 	struct netlink_callback *cb;
 	const struct inet_diag_req_v2 *r;
 	const struct nlmsghdr *nlh;
 	bool net_admin;
 };

 static size_t inet_assoc_attr_size(struct sctp_association *asoc)
 {
 	int addrlen = sizeof(struct sockaddr_storage);
 	int addrcnt = 0;
 	struct sctp_sockaddr_entry *laddr;

 	list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
 				list)
 		addrcnt++;

 	return	  nla_total_size(sizeof(struct sctp_info))
 		+ nla_total_size(addrlen * asoc->peer.transport_count)
 		+ nla_total_size(addrlen * addrcnt)
 		+ nla_total_size(sizeof(struct inet_diag_msg))
 		+ inet_diag_msg_attrs_size()
 		+ nla_total_size(sizeof(struct inet_diag_meminfo))
 		+ 64;
 }

 static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
 {
 	struct sctp_association *assoc = tsp->asoc;
 	struct sock *sk = tsp->asoc->base.sk;
 	struct sctp_comm_param *commp = p;
 	struct sk_buff *in_skb = commp->skb;
 	const struct inet_diag_req_v2 *req = commp->r;
 	const struct nlmsghdr *nlh = commp->nlh;
 	struct net *net = sock_net(in_skb->sk);
 	struct sk_buff *rep;
 	int err;

 	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
 	if (err)
 		goto out;

 	err = -ENOMEM;
 	rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
 	if (!rep)
 		goto out;

 	lock_sock(sk);
 	if (sk != assoc->base.sk) {
 		release_sock(sk);
 		sk = assoc->base.sk;
 		lock_sock(sk);
 	}
 	err = inet_sctp_diag_fill(sk, assoc, rep, req,
 				  sk_user_ns(NETLINK_CB(in_skb).sk),
 				  NETLINK_CB(in_skb).portid,
 				  nlh->nlmsg_seq, 0, nlh,
 				  commp->net_admin);
 	release_sock(sk);
 	if (err < 0) {
 		WARN_ON(err == -EMSGSIZE);
 		kfree_skb(rep);
 		goto out;
 	}

 	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
 			      MSG_DONTWAIT);
 	if (err > 0)
 		err = 0;
 out:
 	return err;
 }

 static int sctp_sock_dump(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
 {
 	struct sctp_comm_param *commp = p;
 	struct sock *sk = ep->base.sk;
 	struct sk_buff *skb = commp->skb;
 	struct netlink_callback *cb = commp->cb;
 	const struct inet_diag_req_v2 *r = commp->r;
 	struct sctp_association *assoc;
 	int err = 0;

 	lock_sock(sk);
 	if (ep != tsp->asoc->ep)
 		goto release;
 	list_for_each_entry(assoc, &ep->asocs, asocs) {
 		if (cb->args[4] < cb->args[1])
 			goto next;

 		if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
 		    r->id.idiag_sport)
 			goto next;
 		if (r->id.idiag_dport != htons(assoc->peer.port) &&
 		    r->id.idiag_dport)
 			goto next;

 		if (!cb->args[3] &&
 		    inet_sctp_diag_fill(sk, NULL, skb, r,
 					sk_user_ns(NETLINK_CB(cb->skb).sk),
 					NETLINK_CB(cb->skb).portid,
 					cb->nlh->nlmsg_seq,
 					NLM_F_MULTI, cb->nlh,
 					commp->net_admin) < 0) {
 			err = 1;
 			goto release;
 		}
 		cb->args[3] = 1;

 		if (inet_sctp_diag_fill(sk, assoc, skb, r,
 					sk_user_ns(NETLINK_CB(cb->skb).sk),
 					NETLINK_CB(cb->skb).portid,
 					cb->nlh->nlmsg_seq, 0, cb->nlh,
 					commp->net_admin) < 0) {
 			err = 1;
 			goto release;
 		}
 next:
 		cb->args[4]++;
 	}
 	cb->args[1] = 0;
 	cb->args[3] = 0;
 	cb->args[4] = 0;
 release:
 	release_sock(sk);
 	return err;
 }

 static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
 {
 	struct sctp_comm_param *commp = p;
 	struct sock *sk = ep->base.sk;
 	const struct inet_diag_req_v2 *r = commp->r;
 	struct sctp_association *assoc =
 		list_entry(ep->asocs.next, struct sctp_association, asocs);

 	/* find the ep only once through the transports by this condition */
 	if (tsp->asoc != assoc)
 		return 0;

 	if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
 		return 0;

 	return 1;
 }

 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
 {
 	struct sctp_comm_param *commp = p;
 	struct sock *sk = ep->base.sk;
 	struct sk_buff *skb = commp->skb;
 	struct netlink_callback *cb = commp->cb;
 	const struct inet_diag_req_v2 *r = commp->r;
 	struct net *net = sock_net(skb->sk);
 	struct inet_sock *inet = inet_sk(sk);
 	int err = 0;

 	if (!net_eq(sock_net(sk), net))
 		goto out;

 	if (cb->args[4] < cb->args[1])
 		goto next;

 	if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
 		goto next;

 	if (r->sdiag_family != AF_UNSPEC &&
 	    sk->sk_family != r->sdiag_family)
 		goto next;

 	if (r->id.idiag_sport != inet->inet_sport &&
 	    r->id.idiag_sport)
 		goto next;

 	if (r->id.idiag_dport != inet->inet_dport &&
 	    r->id.idiag_dport)
 		goto next;

 	if (inet_sctp_diag_fill(sk, NULL, skb, r,
 				sk_user_ns(NETLINK_CB(cb->skb).sk),
 				NETLINK_CB(cb->skb).portid,
 				cb->nlh->nlmsg_seq, NLM_F_MULTI,
 				cb->nlh, commp->net_admin) < 0) {
 		err = 2;
 		goto out;
 	}
 next:
 	cb->args[4]++;
 out:
 	return err;
 }

 /* define the functions for sctp_diag_handler*/
 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 			       void *info)
 {
 	struct sctp_infox *infox = (struct sctp_infox *)info;

 	if (infox->asoc) {
 		r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
 		r->idiag_wqueue = infox->asoc->sndbuf_used;
 	} else {
 		r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
 		r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
 	}
 	if (infox->sctpinfo)
 		sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
 }

 static int sctp_diag_dump_one(struct netlink_callback *cb,
 			      const struct inet_diag_req_v2 *req)
 {
 	struct sk_buff *in_skb = cb->skb;
 	struct net *net = sock_net(in_skb->sk);
 	const struct nlmsghdr *nlh = cb->nlh;
 	union sctp_addr laddr, paddr;
 	struct sctp_comm_param commp = {
 		.skb = in_skb,
 		.r = req,
 		.nlh = nlh,
 		.net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
 	};

 	if (req->sdiag_family == AF_INET) {
 		laddr.v4.sin_port = req->id.idiag_sport;
 		laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
 		laddr.v4.sin_family = AF_INET;

 		paddr.v4.sin_port = req->id.idiag_dport;
 		paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
 		paddr.v4.sin_family = AF_INET;
 	} else {
 		laddr.v6.sin6_port = req->id.idiag_sport;
 		memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
 		       sizeof(laddr.v6.sin6_addr));
 		laddr.v6.sin6_family = AF_INET6;

 		paddr.v6.sin6_port = req->id.idiag_dport;
 		memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
 		       sizeof(paddr.v6.sin6_addr));
 		paddr.v6.sin6_family = AF_INET6;
 	}

 	return sctp_transport_lookup_process(sctp_tsp_dump_one,
 					     net, &laddr, &paddr, &commp);
 }

 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			   const struct inet_diag_req_v2 *r)
 {
 	u32 idiag_states = r->idiag_states;
 	struct net *net = sock_net(skb->sk);
 	struct sctp_comm_param commp = {
 		.skb = skb,
 		.cb = cb,
 		.r = r,
 		.net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
 	};
 	int pos = cb->args[2];

 	/* eps hashtable dumps
 	 * args:
 	 * 0 : if it will traversal listen sock
 	 * 1 : to record the sock pos of this time's traversal
 	 * 4 : to work as a temporary variable to traversal list
 	 */
 	if (cb->args[0] == 0) {
 		if (!(idiag_states & TCPF_LISTEN))
 			goto skip;
 		if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
 			goto done;
 skip:
 		cb->args[0] = 1;
 		cb->args[1] = 0;
 		cb->args[4] = 0;
 	}

 	/* asocs by transport hashtable dump
 	 * args:
 	 * 1 : to record the assoc pos of this time's traversal
 	 * 2 : to record the transport pos of this time's traversal
 	 * 3 : to mark if we have dumped the ep info of the current asoc
 	 * 4 : to work as a temporary variable to traversal list
 	 * 5 : to save the sk we get from travelsing the tsp list.
 	 */
 	if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
 		goto done;

 	sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump,
 					net, &pos, &commp);
 	cb->args[2] = pos;

 done:
 	cb->args[1] = cb->args[4];
 	cb->args[4] = 0;
 }

 static const struct inet_diag_handler sctp_diag_handler = {
 	.dump		 = sctp_diag_dump,
 	.dump_one	 = sctp_diag_dump_one,
 	.idiag_get_info  = sctp_diag_get_info,
 	.idiag_type	 = IPPROTO_SCTP,
 	.idiag_info_size = sizeof(struct sctp_info),
 };

 static int __init sctp_diag_init(void)
 {
 	return inet_diag_register(&sctp_diag_handler);
 }

 static void __exit sctp_diag_exit(void)
 {
 	inet_diag_unregister(&sctp_diag_handler);
 }

 module_init(sctp_diag_init);
 module_exit(sctp_diag_exit);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/* SCTP kernel implementation
	* (C) Copyright Red Hat Inc. 2017
	*
	* This file is part of the SCTP kernel implementation
	*
	* These functions implement sctp diag support.
	*
	* Please send any bug reports or fixes you make to the
	* email addresched(es):
	* lksctp developers <linux-sctp@vger.kernel.org>
	*
	* Written or modified by:
	* Xin Long <lucien.xin@gmail.com>
	*/

	#include <linux/module.h>
	#include <linux/inet_diag.h>
	#include <linux/sock_diag.h>
	#include <net/sctp/sctp.h>

	static void sctp_diag_get_info(struct sock sk, struct inet_diag_msg r,
	void *info);

	/* define some functions to make asoc/ep fill look clean */
	static void inet_diag_msg_sctpasoc_fill(struct inet_diag_msg *r,
	struct sock *sk,
	struct sctp_association *asoc)
	{
	union sctp_addr laddr, paddr;
	struct dst_entry *dst;
	struct timer_list *t3_rtx = &asoc->peer.primary_path->T3_rtx_timer;

	laddr = list_entry(asoc->base.bind_addr.address_list.next,
	struct sctp_sockaddr_entry, list)->a;
	paddr = asoc->peer.primary_path->ipaddr;
	dst = asoc->peer.primary_path->dst;

	r->idiag_family = sk->sk_family;
	r->id.idiag_sport = htons(asoc->base.bind_addr.port);
	r->id.idiag_dport = htons(asoc->peer.port);
	r->id.idiag_if = dst ? dst->dev->ifindex : 0;
	sock_diag_save_cookie(sk, r->id.idiag_cookie);

	#if IS_ENABLED(CONFIG_IPV6)
	if (sk->sk_family == AF_INET6) {
	(struct in6_addr )r->id.idiag_src = laddr.v6.sin6_addr;
	(struct in6_addr )r->id.idiag_dst = paddr.v6.sin6_addr;
	} else
	#endif
	{
	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));

	r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr;
	r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr;
	}

	r->idiag_state = asoc->state;
	if (timer_pending(t3_rtx)) {
	r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX;
	r->idiag_retrans = asoc->rtx_data_chunks;
	r->idiag_expires = jiffies_to_msecs(t3_rtx->expires - jiffies);
	} else {
	r->idiag_timer = 0;
	r->idiag_retrans = 0;
	r->idiag_expires = 0;
	}
	}

	static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb,
	struct list_head *address_list)
	{
	struct sctp_sockaddr_entry *laddr;
	int addrlen = sizeof(struct sockaddr_storage);
	int addrcnt = 0;
	struct nlattr *attr;
	void *info = NULL;

	list_for_each_entry_rcu(laddr, address_list, list)
	addrcnt++;

	attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
	if (!attr)
	return -EMSGSIZE;

	info = nla_data(attr);
	list_for_each_entry_rcu(laddr, address_list, list) {
	memcpy(info, &laddr->a, sizeof(laddr->a));
	memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
	info += addrlen;
	}

	return 0;
	}

	static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
	struct sctp_association *asoc)
	{
	int addrlen = sizeof(struct sockaddr_storage);
	struct sctp_transport *from;
	struct nlattr *attr;
	void *info = NULL;

	attr = nla_reserve(skb, INET_DIAG_PEERS,
	addrlen * asoc->peer.transport_count);
	if (!attr)
	return -EMSGSIZE;

	info = nla_data(attr);
	list_for_each_entry(from, &asoc->peer.transport_addr_list,
	transports) {
	memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
	memset(info + sizeof(from->ipaddr), 0,
	addrlen - sizeof(from->ipaddr));
	info += addrlen;
	}

	return 0;
	}

	/* sctp asoc/ep fill*/
	static int inet_sctp_diag_fill(struct sock sk, struct sctp_association asoc,
	struct sk_buff *skb,
	const struct inet_diag_req_v2 *req,
	struct user_namespace *user_ns,
	int portid, u32 seq, u16 nlmsg_flags,
	const struct nlmsghdr *unlh,
	bool net_admin)
	{
	struct sctp_endpoint *ep = sctp_sk(sk)->ep;
	struct list_head *addr_list;
	struct inet_diag_msg *r;
	struct nlmsghdr *nlh;
	int ext = req->idiag_ext;
	struct sctp_infox infox;
	void *info = NULL;

	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));

	if (asoc) {
	inet_diag_msg_sctpasoc_fill(r, sk, asoc);
	} else {
	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_SKMEMINFO - 1))) {
	u32 mem[SK_MEMINFO_VARS];
	int amt;

	if (asoc && asoc->ep->sndbuf_policy)
	amt = asoc->sndbuf_used;
	else
	amt = sk_wmem_alloc_get(sk);
	mem[SK_MEMINFO_WMEM_ALLOC] = amt;
	if (asoc && asoc->ep->rcvbuf_policy)
	amt = atomic_read(&asoc->rmem_alloc);
	else
	amt = sk_rmem_alloc_get(sk);
	mem[SK_MEMINFO_RMEM_ALLOC] = amt;
	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);

	if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
	goto errout;
	}

	if (ext & (1 << (INET_DIAG_INFO - 1))) {
	struct nlattr *attr;

	attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
	sizeof(struct sctp_info),
	INET_DIAG_PAD);
	if (!attr)
	goto errout;

	info = nla_data(attr);
	}
	infox.sctpinfo = (struct sctp_info *)info;
	infox.asoc = asoc;
	sctp_diag_get_info(sk, r, &infox);

	addr_list = asoc ? &asoc->base.bind_addr.address_list
	: &ep->base.bind_addr.address_list;
	if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
	goto errout;

	if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
	if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
	goto errout;

	if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
	goto errout;

	nlmsg_end(skb, nlh);
	return 0;

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

	/* callback and param */
	struct sctp_comm_param {
	struct sk_buff *skb;
	struct netlink_callback *cb;
	const struct inet_diag_req_v2 *r;
	const struct nlmsghdr *nlh;
	bool net_admin;
	};

	static size_t inet_assoc_attr_size(struct sctp_association *asoc)
	{
	int addrlen = sizeof(struct sockaddr_storage);
	int addrcnt = 0;
	struct sctp_sockaddr_entry *laddr;

	list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
	list)
	addrcnt++;

	return nla_total_size(sizeof(struct sctp_info))
	+ nla_total_size(addrlen * asoc->peer.transport_count)
	+ nla_total_size(addrlen * addrcnt)
	+ nla_total_size(sizeof(struct inet_diag_msg))
	+ inet_diag_msg_attrs_size()
	+ nla_total_size(sizeof(struct inet_diag_meminfo))
	+ 64;
	}

	static int sctp_tsp_dump_one(struct sctp_transport tsp, void p)
	{
	struct sctp_association *assoc = tsp->asoc;
	struct sock *sk = tsp->asoc->base.sk;
	struct sctp_comm_param *commp = p;
	struct sk_buff *in_skb = commp->skb;
	const struct inet_diag_req_v2 *req = commp->r;
	const struct nlmsghdr *nlh = commp->nlh;
	struct net *net = sock_net(in_skb->sk);
	struct sk_buff *rep;
	int err;

	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
	if (err)
	goto out;

	err = -ENOMEM;
	rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
	if (!rep)
	goto out;

	lock_sock(sk);
	if (sk != assoc->base.sk) {
	release_sock(sk);
	sk = assoc->base.sk;
	lock_sock(sk);
	}
	err = inet_sctp_diag_fill(sk, assoc, rep, req,
	sk_user_ns(NETLINK_CB(in_skb).sk),
	NETLINK_CB(in_skb).portid,
	nlh->nlmsg_seq, 0, nlh,
	commp->net_admin);
	release_sock(sk);
	if (err < 0) {
	WARN_ON(err == -EMSGSIZE);
	kfree_skb(rep);
	goto out;
	}

	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
	MSG_DONTWAIT);
	if (err > 0)
	err = 0;
	out:
	return err;
	}

	static int sctp_sock_dump(struct sctp_endpoint ep, struct sctp_transport tsp, void *p)
	{
	struct sctp_comm_param *commp = p;
	struct sock *sk = ep->base.sk;
	struct sk_buff *skb = commp->skb;
	struct netlink_callback *cb = commp->cb;
	const struct inet_diag_req_v2 *r = commp->r;
	struct sctp_association *assoc;
	int err = 0;

	lock_sock(sk);
	if (ep != tsp->asoc->ep)
	goto release;
	list_for_each_entry(assoc, &ep->asocs, asocs) {
	if (cb->args[4] < cb->args[1])
	goto next;

	if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
	r->id.idiag_sport)
	goto next;
	if (r->id.idiag_dport != htons(assoc->peer.port) &&
	r->id.idiag_dport)
	goto next;

	if (!cb->args[3] &&
	inet_sctp_diag_fill(sk, NULL, skb, r,
	sk_user_ns(NETLINK_CB(cb->skb).sk),
	NETLINK_CB(cb->skb).portid,
	cb->nlh->nlmsg_seq,
	NLM_F_MULTI, cb->nlh,
	commp->net_admin) < 0) {
	err = 1;
	goto release;
	}
	cb->args[3] = 1;

	if (inet_sctp_diag_fill(sk, assoc, skb, r,
	sk_user_ns(NETLINK_CB(cb->skb).sk),
	NETLINK_CB(cb->skb).portid,
	cb->nlh->nlmsg_seq, 0, cb->nlh,
	commp->net_admin) < 0) {
	err = 1;
	goto release;
	}
	next:
	cb->args[4]++;
	}
	cb->args[1] = 0;
	cb->args[3] = 0;
	cb->args[4] = 0;
	release:
	release_sock(sk);
	return err;
	}

	static int sctp_sock_filter(struct sctp_endpoint ep, struct sctp_transport tsp, void *p)
	{
	struct sctp_comm_param *commp = p;
	struct sock *sk = ep->base.sk;
	const struct inet_diag_req_v2 *r = commp->r;
	struct sctp_association *assoc =
	list_entry(ep->asocs.next, struct sctp_association, asocs);

	/* find the ep only once through the transports by this condition */
	if (tsp->asoc != assoc)
	return 0;

	if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
	return 0;

	return 1;
	}

	static int sctp_ep_dump(struct sctp_endpoint ep, void p)
	{
	struct sctp_comm_param *commp = p;
	struct sock *sk = ep->base.sk;
	struct sk_buff *skb = commp->skb;
	struct netlink_callback *cb = commp->cb;
	const struct inet_diag_req_v2 *r = commp->r;
	struct net *net = sock_net(skb->sk);
	struct inet_sock *inet = inet_sk(sk);
	int err = 0;

	if (!net_eq(sock_net(sk), net))
	goto out;

	if (cb->args[4] < cb->args[1])
	goto next;

	if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
	goto next;

	if (r->sdiag_family != AF_UNSPEC &&
	sk->sk_family != r->sdiag_family)
	goto next;

	if (r->id.idiag_sport != inet->inet_sport &&
	r->id.idiag_sport)
	goto next;

	if (r->id.idiag_dport != inet->inet_dport &&
	r->id.idiag_dport)
	goto next;

	if (inet_sctp_diag_fill(sk, NULL, skb, r,
	sk_user_ns(NETLINK_CB(cb->skb).sk),
	NETLINK_CB(cb->skb).portid,
	cb->nlh->nlmsg_seq, NLM_F_MULTI,
	cb->nlh, commp->net_admin) < 0) {
	err = 2;
	goto out;
	}
	next:
	cb->args[4]++;
	out:
	return err;
	}

	/* define the functions for sctp_diag_handler*/
	static void sctp_diag_get_info(struct sock sk, struct inet_diag_msg r,
	void *info)
	{
	struct sctp_infox infox = (struct sctp_infox )info;

	if (infox->asoc) {
	r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
	r->idiag_wqueue = infox->asoc->sndbuf_used;
	} else {
	r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
	r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
	}
	if (infox->sctpinfo)
	sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
	}

	static int sctp_diag_dump_one(struct netlink_callback *cb,
	const struct inet_diag_req_v2 *req)
	{
	struct sk_buff *in_skb = cb->skb;
	struct net *net = sock_net(in_skb->sk);
	const struct nlmsghdr *nlh = cb->nlh;
	union sctp_addr laddr, paddr;
	struct sctp_comm_param commp = {
	.skb = in_skb,
	.r = req,
	.nlh = nlh,
	.net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
	};

	if (req->sdiag_family == AF_INET) {
	laddr.v4.sin_port = req->id.idiag_sport;
	laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
	laddr.v4.sin_family = AF_INET;

	paddr.v4.sin_port = req->id.idiag_dport;
	paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
	paddr.v4.sin_family = AF_INET;
	} else {
	laddr.v6.sin6_port = req->id.idiag_sport;
	memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
	sizeof(laddr.v6.sin6_addr));
	laddr.v6.sin6_family = AF_INET6;

	paddr.v6.sin6_port = req->id.idiag_dport;
	memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
	sizeof(paddr.v6.sin6_addr));
	paddr.v6.sin6_family = AF_INET6;
	}

	return sctp_transport_lookup_process(sctp_tsp_dump_one,
	net, &laddr, &paddr, &commp);
	}

	static void sctp_diag_dump(struct sk_buff skb, struct netlink_callback cb,
	const struct inet_diag_req_v2 *r)
	{
	u32 idiag_states = r->idiag_states;
	struct net *net = sock_net(skb->sk);
	struct sctp_comm_param commp = {
	.skb = skb,
	.cb = cb,
	.r = r,
	.net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
	};
	int pos = cb->args[2];

	/* eps hashtable dumps
	* args:
	* 0 : if it will traversal listen sock
	* 1 : to record the sock pos of this time's traversal
	* 4 : to work as a temporary variable to traversal list
	*/
	if (cb->args[0] == 0) {
	if (!(idiag_states & TCPF_LISTEN))
	goto skip;
	if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
	goto done;
	skip:
	cb->args[0] = 1;
	cb->args[1] = 0;
	cb->args[4] = 0;
	}

	/* asocs by transport hashtable dump
	* args:
	* 1 : to record the assoc pos of this time's traversal
	* 2 : to record the transport pos of this time's traversal
	* 3 : to mark if we have dumped the ep info of the current asoc
	* 4 : to work as a temporary variable to traversal list
	* 5 : to save the sk we get from travelsing the tsp list.
	*/
	if (!(idiag_states & ~(TCPF_LISTEN \| TCPF_CLOSE)))
	goto done;

	sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump,
	net, &pos, &commp);
	cb->args[2] = pos;

	done:
	cb->args[1] = cb->args[4];
	cb->args[4] = 0;
	}

	static const struct inet_diag_handler sctp_diag_handler = {
	.dump = sctp_diag_dump,
	.dump_one = sctp_diag_dump_one,
	.idiag_get_info = sctp_diag_get_info,
	.idiag_type = IPPROTO_SCTP,
	.idiag_info_size = sizeof(struct sctp_info),
	};

	static int __init sctp_diag_init(void)
	{
	return inet_diag_register(&sctp_diag_handler);
	}

	static void __exit sctp_diag_exit(void)
	{
	inet_diag_unregister(&sctp_diag_handler);
	}

	module_init(sctp_diag_init);
	module_exit(sctp_diag_exit);
	MODULE_LICENSE("GPL");
	MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);