Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next

Florian Westphal says:

====================
The following set contains changes for your *net-next* tree:

- make conntrack ignore packets that are delayed (containing
data already acked). The current behaviour to flag them as INVALID
causes more harm than good, let them pass so peer can send an
immediate ACK for the most recent sequence number.
- make conntrack recognize when both peers have sent 'invalid' FINs:
This helps cleaning out stale connections faster for those cases where
conntrack is no longer in sync with the actual connection state.
- Now that DECNET is gone, we don't need to reserve space for DECNET
related information.
- compact common 'find a free port number for the new inbound
connection' code and move it to a helper, then cap number of tries
the new helper will make until it gives up.
- replace various instances of strlcpy with strscpy, from Wolfram Sang.
====================

Signed-off-by: David S. Miller <[e-mail]>

include/net/netfilter/nf_nat_helper.h

···
  * to port ct->master->saved_proto. */
 void nf_nat_follow_master(struct nf_conn *ct, struct nf_conntrack_expect *this);
 
+u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port);
 #endif

include/uapi/linux/netfilter.h

···
 	NFPROTO_NETDEV =  5,
 	NFPROTO_BRIDGE =  7,
 	NFPROTO_IPV6   = 10,
+#ifndef __KERNEL__ /* no longer supported by kernel */
 	NFPROTO_DECNET = 12,
+#endif
 	NFPROTO_NUMPROTO,
 };
 

net/ipv4/netfilter/nf_nat_h323.c

···
 	exp->expectfn = nf_nat_follow_master;
 	exp->dir = !dir;
 
-	/* Try to get same port: if not, try to change it. */
-	for (; nated_port != 0; nated_port++) {
-		int ret;
-
-		exp->tuple.dst.u.tcp.port = htons(nated_port);
-		ret = nf_ct_expect_related(exp, 0);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			nated_port = 0;
-			break;
-		}
-	}
-
+	nated_port = nf_nat_exp_find_port(exp, nated_port);
 	if (nated_port == 0) {	/* No port available */
 		net_notice_ratelimited("nf_nat_h323: out of TCP ports\n");
 		return 0;
···
 	if (info->sig_port[dir] == port)
 		nated_port = ntohs(info->sig_port[!dir]);
 
-	/* Try to get same port: if not, try to change it. */
-	for (; nated_port != 0; nated_port++) {
-		int ret;
-
-		exp->tuple.dst.u.tcp.port = htons(nated_port);
-		ret = nf_ct_expect_related(exp, 0);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			nated_port = 0;
-			break;
-		}
-	}
-
+	nated_port = nf_nat_exp_find_port(exp, nated_port);
 	if (nated_port == 0) {	/* No port available */
 		net_notice_ratelimited("nf_nat_q931: out of TCP ports\n");
 		return 0;
···
 	if (info->sig_port[dir] == port)
 		nated_port = ntohs(info->sig_port[!dir]);
 
-	/* Try to get same port: if not, try to change it. */
-	for (; nated_port != 0; nated_port++) {
-		int ret;
-
-		exp->tuple.dst.u.tcp.port = htons(nated_port);
-		ret = nf_ct_expect_related(exp, 0);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			nated_port = 0;
-			break;
-		}
-	}
-
+	nated_port = nf_nat_exp_find_port(exp, nated_port);
 	if (nated_port == 0) {	/* No port available */
 		net_notice_ratelimited("nf_nat_ras: out of TCP ports\n");
 		return 0;
···
 	exp->expectfn = ip_nat_callforwarding_expect;
 	exp->dir = !dir;
 
-	/* Try to get same port: if not, try to change it. */
-	for (nated_port = ntohs(port); nated_port != 0; nated_port++) {
-		int ret;
-
-		exp->tuple.dst.u.tcp.port = htons(nated_port);
-		ret = nf_ct_expect_related(exp, 0);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			nated_port = 0;
-			break;
-		}
-	}
-
+	nated_port = nf_nat_exp_find_port(exp, ntohs(port));
 	if (nated_port == 0) {	/* No port available */
 		net_notice_ratelimited("nf_nat_q931: out of TCP ports\n");
 		return 0;

net/netfilter/ipset/ip_set_core.c

···
 	c = kmalloc(sizeof(*c) + len + 1, GFP_ATOMIC);
 	if (unlikely(!c))
 		return;
-	strlcpy(c->str, ext->comment, len + 1);
+	strscpy(c->str, ext->comment, len + 1);
 	set->ext_size += sizeof(*c) + strlen(c->str) + 1;
 	rcu_assign_pointer(comment->c, c);
 }
···
 	if (!set)
 		return -ENOMEM;
 	spin_lock_init(&set->lock);
-	strlcpy(set->name, name, IPSET_MAXNAMELEN);
+	strscpy(set->name, name, IPSET_MAXNAMELEN);
 	set->family = family;
 	set->revision = revision;
 

net/netfilter/ipvs/ip_vs_ctl.c

···
 	dst->addr = src->addr.ip;
 	dst->port = src->port;
 	dst->fwmark = src->fwmark;
-	strlcpy(dst->sched_name, sched_name, sizeof(dst->sched_name));
+	strscpy(dst->sched_name, sched_name, sizeof(dst->sched_name));
 	dst->flags = src->flags;
 	dst->timeout = src->timeout / HZ;
 	dst->netmask = src->netmask;
···
 		mutex_lock(&ipvs->sync_mutex);
 		if (ipvs->sync_state & IP_VS_STATE_MASTER) {
 			d[0].state = IP_VS_STATE_MASTER;
-			strlcpy(d[0].mcast_ifn, ipvs->mcfg.mcast_ifn,
+			strscpy(d[0].mcast_ifn, ipvs->mcfg.mcast_ifn,
 				sizeof(d[0].mcast_ifn));
 			d[0].syncid = ipvs->mcfg.syncid;
 		}
 		if (ipvs->sync_state & IP_VS_STATE_BACKUP) {
 			d[1].state = IP_VS_STATE_BACKUP;
-			strlcpy(d[1].mcast_ifn, ipvs->bcfg.mcast_ifn,
+			strscpy(d[1].mcast_ifn, ipvs->bcfg.mcast_ifn,
 				sizeof(d[1].mcast_ifn));
 			d[1].syncid = ipvs->bcfg.syncid;
 		}
···
 	      attrs[IPVS_DAEMON_ATTR_MCAST_IFN] &&
 	      attrs[IPVS_DAEMON_ATTR_SYNC_ID]))
 		return -EINVAL;
-	strlcpy(c.mcast_ifn, nla_data(attrs[IPVS_DAEMON_ATTR_MCAST_IFN]),
+	strscpy(c.mcast_ifn, nla_data(attrs[IPVS_DAEMON_ATTR_MCAST_IFN]),
 		sizeof(c.mcast_ifn));
 	c.syncid = nla_get_u32(attrs[IPVS_DAEMON_ATTR_SYNC_ID]);
 

net/netfilter/nf_conntrack_proto_tcp.c

···
 	"SYN_SENT2",
 };
 
+enum nf_ct_tcp_action {
+	NFCT_TCP_IGNORE,
+	NFCT_TCP_INVALID,
+	NFCT_TCP_ACCEPT,
+};
+
 #define SECS * HZ
 #define MINS * 60 SECS
 #define HOURS * 60 MINS
···
 	}
 }
 
-static bool tcp_in_window(struct nf_conn *ct,
-			  enum ip_conntrack_dir dir,
-			  unsigned int index,
-			  const struct sk_buff *skb,
-			  unsigned int dataoff,
-			  const struct tcphdr *tcph,
-			  const struct nf_hook_state *hook_state)
+__printf(6, 7)
+static enum nf_ct_tcp_action nf_tcp_log_invalid(const struct sk_buff *skb,
+						const struct nf_conn *ct,
+						const struct nf_hook_state *state,
+						const struct ip_ct_tcp_state *sender,
+						enum nf_ct_tcp_action ret,
+						const char *fmt, ...)
+{
+	const struct nf_tcp_net *tn = nf_tcp_pernet(nf_ct_net(ct));
+	struct va_format vaf;
+	va_list args;
+	bool be_liberal;
+
+	be_liberal = sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL || tn->tcp_be_liberal;
+	if (be_liberal)
+		return NFCT_TCP_ACCEPT;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	nf_ct_l4proto_log_invalid(skb, ct, state, "%pV", &vaf);
+	va_end(args);
+
+	return ret;
+}
+
+static enum nf_ct_tcp_action
+tcp_in_window(struct nf_conn *ct, enum ip_conntrack_dir dir,
+	      unsigned int index, const struct sk_buff *skb,
+	      unsigned int dataoff, const struct tcphdr *tcph,
+	      const struct nf_hook_state *hook_state)
 {
 	struct ip_ct_tcp *state = &ct->proto.tcp;
-	struct net *net = nf_ct_net(ct);
-	struct nf_tcp_net *tn = nf_tcp_pernet(net);
 	struct ip_ct_tcp_state *sender = &state->seen[dir];
 	struct ip_ct_tcp_state *receiver = &state->seen[!dir];
 	__u32 seq, ack, sack, end, win, swin;
-	u16 win_raw;
+	bool in_recv_win, seq_ok;
 	s32 receiver_offset;
-	bool res, in_recv_win;
+	u16 win_raw;
 
 	/*
 	 * Get the required data from the packet.
···
 					end, win);
 			if (!tcph->ack)
 				/* Simultaneous open */
-				return true;
+				return NFCT_TCP_ACCEPT;
 		} else {
 			/*
 			 * We are in the middle of a connection,
···
 				end, win);
 
 		if (dir == IP_CT_DIR_REPLY && !tcph->ack)
-			return true;
+			return NFCT_TCP_ACCEPT;
 	}
 
 	if (!(tcph->ack)) {
···
 		 */
 		seq = end = sender->td_end;
 
+	seq_ok = before(seq, sender->td_maxend + 1);
+	if (!seq_ok) {
+		u32 overshot = end - sender->td_maxend + 1;
+		bool ack_ok;
+
+		ack_ok = after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1);
+		in_recv_win = receiver->td_maxwin &&
+			      after(end, sender->td_end - receiver->td_maxwin - 1);
+
+		if (in_recv_win &&
+		    ack_ok &&
+		    overshot <= receiver->td_maxwin &&
+		    before(sack, receiver->td_end + 1)) {
+			/* Work around TCPs that send more bytes than allowed by
+			 * the receive window.
+			 *
+			 * If the (marked as invalid) packet is allowed to pass by
+			 * the ruleset and the peer acks this data, then its possible
+			 * all future packets will trigger 'ACK is over upper bound' check.
+			 *
+			 * Thus if only the sequence check fails then do update td_end so
+			 * possible ACK for this data can update internal state.
+			 */
+			sender->td_end = end;
+			sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
+
+			return nf_tcp_log_invalid(skb, ct, hook_state, sender, NFCT_TCP_IGNORE,
+						  "%u bytes more than expected", overshot);
+		}
+
+		return nf_tcp_log_invalid(skb, ct, hook_state, sender, NFCT_TCP_INVALID,
+					  "SEQ is over upper bound %u (over the window of the receiver)",
+					  sender->td_maxend + 1);
+	}
+
+	if (!before(sack, receiver->td_end + 1))
+		return nf_tcp_log_invalid(skb, ct, hook_state, sender, NFCT_TCP_INVALID,
+					  "ACK is over upper bound %u (ACKed data not seen yet)",
+					  receiver->td_end + 1);
+
 	/* Is the ending sequence in the receive window (if available)? */
 	in_recv_win = !receiver->td_maxwin ||
 		      after(end, sender->td_end - receiver->td_maxwin - 1);
+	if (!in_recv_win)
+		return nf_tcp_log_invalid(skb, ct, hook_state, sender, NFCT_TCP_IGNORE,
+					  "SEQ is under lower bound %u (already ACKed data retransmitted)",
+					  sender->td_end - receiver->td_maxwin - 1);
+	if (!after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1))
+		return nf_tcp_log_invalid(skb, ct, hook_state, sender, NFCT_TCP_IGNORE,
+					  "ignored ACK under lower bound %u (possible overly delayed)",
+					  receiver->td_end - MAXACKWINDOW(sender) - 1);
 
-	if (before(seq, sender->td_maxend + 1) &&
-	    in_recv_win &&
-	    before(sack, receiver->td_end + 1) &&
-	    after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1)) {
-		/*
-		 * Take into account window scaling (RFC 1323).
-		 */
-		if (!tcph->syn)
-			win <<= sender->td_scale;
+	/* Take into account window scaling (RFC 1323). */
+	if (!tcph->syn)
+		win <<= sender->td_scale;
 
-		/*
-		 * Update sender data.
-		 */
-		swin = win + (sack - ack);
-		if (sender->td_maxwin < swin)
-			sender->td_maxwin = swin;
-		if (after(end, sender->td_end)) {
-			sender->td_end = end;
-			sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
-		}
-		if (tcph->ack) {
-			if (!(sender->flags & IP_CT_TCP_FLAG_MAXACK_SET)) {
-				sender->td_maxack = ack;
-				sender->flags |= IP_CT_TCP_FLAG_MAXACK_SET;
-			} else if (after(ack, sender->td_maxack))
-				sender->td_maxack = ack;
-		}
-
-		/*
-		 * Update receiver data.
-		 */
-		if (receiver->td_maxwin != 0 && after(end, sender->td_maxend))
-			receiver->td_maxwin += end - sender->td_maxend;
-		if (after(sack + win, receiver->td_maxend - 1)) {
-			receiver->td_maxend = sack + win;
-			if (win == 0)
-				receiver->td_maxend++;
-		}
-		if (ack == receiver->td_end)
-			receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
-
-		/*
-		 * Check retransmissions.
-		 */
-		if (index == TCP_ACK_SET) {
-			if (state->last_dir == dir
-			    && state->last_seq == seq
-			    && state->last_ack == ack
-			    && state->last_end == end
-			    && state->last_win == win_raw)
-				state->retrans++;
-			else {
-				state->last_dir = dir;
-				state->last_seq = seq;
-				state->last_ack = ack;
-				state->last_end = end;
-				state->last_win = win_raw;
-				state->retrans = 0;
-			}
-		}
-		res = true;
-	} else {
-		res = false;
-		if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL ||
-		    tn->tcp_be_liberal)
-			res = true;
-		if (!res) {
-			bool seq_ok = before(seq, sender->td_maxend + 1);
-
-			if (!seq_ok) {
-				u32 overshot = end - sender->td_maxend + 1;
-				bool ack_ok;
-
-				ack_ok = after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1);
-
-				if (in_recv_win &&
-				    ack_ok &&
-				    overshot <= receiver->td_maxwin &&
-				    before(sack, receiver->td_end + 1)) {
-					/* Work around TCPs that send more bytes than allowed by
-					 * the receive window.
-					 *
-					 * If the (marked as invalid) packet is allowed to pass by
-					 * the ruleset and the peer acks this data, then its possible
-					 * all future packets will trigger 'ACK is over upper bound' check.
-					 *
-					 * Thus if only the sequence check fails then do update td_end so
-					 * possible ACK for this data can update internal state.
-					 */
-					sender->td_end = end;
-					sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
-
-					nf_ct_l4proto_log_invalid(skb, ct, hook_state,
-								  "%u bytes more than expected", overshot);
-					return res;
-				}
-			}
-
-			nf_ct_l4proto_log_invalid(skb, ct, hook_state,
-			"%s",
-			before(seq, sender->td_maxend + 1) ?
-			in_recv_win ?
-			before(sack, receiver->td_end + 1) ?
-			after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1) ? "BUG"
-			: "ACK is under the lower bound (possible overly delayed ACK)"
-			: "ACK is over the upper bound (ACKed data not seen yet)"
-			: "SEQ is under the lower bound (already ACKed data retransmitted)"
-			: "SEQ is over the upper bound (over the window of the receiver)");
+	/* Update sender data. */
+	swin = win + (sack - ack);
+	if (sender->td_maxwin < swin)
+		sender->td_maxwin = swin;
+	if (after(end, sender->td_end)) {
+		sender->td_end = end;
+		sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
+	}
+	if (tcph->ack) {
+		if (!(sender->flags & IP_CT_TCP_FLAG_MAXACK_SET)) {
+			sender->td_maxack = ack;
+			sender->flags |= IP_CT_TCP_FLAG_MAXACK_SET;
+		} else if (after(ack, sender->td_maxack)) {
+			sender->td_maxack = ack;
 		}
 	}
 
-	return res;
+	/* Update receiver data. */
+	if (receiver->td_maxwin != 0 && after(end, sender->td_maxend))
+		receiver->td_maxwin += end - sender->td_maxend;
+	if (after(sack + win, receiver->td_maxend - 1)) {
+		receiver->td_maxend = sack + win;
+		if (win == 0)
+			receiver->td_maxend++;
+	}
+	if (ack == receiver->td_end)
+		receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED;
+
+	/* Check retransmissions. */
+	if (index == TCP_ACK_SET) {
+		if (state->last_dir == dir &&
+		    state->last_seq == seq &&
+		    state->last_ack == ack &&
+		    state->last_end == end &&
+		    state->last_win == win_raw) {
+			state->retrans++;
+		} else {
+			state->last_dir = dir;
+			state->last_seq = seq;
+			state->last_ack = ack;
+			state->last_end = end;
+			state->last_win = win_raw;
+			state->retrans = 0;
+		}
+	}
+
+	return NFCT_TCP_ACCEPT;
+}
+
+static void __cold nf_tcp_handle_invalid(struct nf_conn *ct,
+					 enum ip_conntrack_dir dir,
+					 int index,
+					 const struct sk_buff *skb,
+					 const struct nf_hook_state *hook_state)
+{
+	const unsigned int *timeouts;
+	const struct nf_tcp_net *tn;
+	unsigned int timeout;
+	u32 expires;
+
+	if (!test_bit(IPS_ASSURED_BIT, &ct->status) ||
+	    test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
+		return;
+
+	/* We don't want to have connections hanging around in ESTABLISHED
+	 * state for long time 'just because' conntrack deemed a FIN/RST
+	 * out-of-window.
+	 *
+	 * Shrink the timeout just like when there is unacked data.
+	 * This speeds up eviction of 'dead' connections where the
+	 * connection and conntracks internal state are out of sync.
+	 */
+	switch (index) {
+	case TCP_RST_SET:
+	case TCP_FIN_SET:
+		break;
+	default:
+		return;
+	}
+
+	if (ct->proto.tcp.last_dir != dir &&
+	    (ct->proto.tcp.last_index == TCP_FIN_SET ||
+	     ct->proto.tcp.last_index == TCP_RST_SET)) {
+		expires = nf_ct_expires(ct);
+		if (expires < 120 * HZ)
+			return;
+
+		tn = nf_tcp_pernet(nf_ct_net(ct));
+		timeouts = nf_ct_timeout_lookup(ct);
+		if (!timeouts)
+			timeouts = tn->timeouts;
+
+		timeout = READ_ONCE(timeouts[TCP_CONNTRACK_UNACK]);
+		if (expires > timeout) {
+			nf_ct_l4proto_log_invalid(skb, ct, hook_state,
+					  "packet (index %d, dir %d) response for index %d lower timeout to %u",
+					  index, dir, ct->proto.tcp.last_index, timeout);
+
+			WRITE_ONCE(ct->timeout, timeout + nfct_time_stamp);
+		}
+	} else {
+		ct->proto.tcp.last_index = index;
+		ct->proto.tcp.last_dir = dir;
+	}
 }
 
 /* table of valid flag combinations - PUSH, ECE and CWR are always valid */
···
 	struct nf_conntrack_tuple *tuple;
 	enum tcp_conntrack new_state, old_state;
 	unsigned int index, *timeouts;
+	enum nf_ct_tcp_action res;
 	enum ip_conntrack_dir dir;
 	const struct tcphdr *th;
 	struct tcphdr _tcph;
···
 		break;
 	}
 
-	if (!tcp_in_window(ct, dir, index,
-			   skb, dataoff, th, state)) {
+	res = tcp_in_window(ct, dir, index,
+			    skb, dataoff, th, state);
+	switch (res) {
+	case NFCT_TCP_IGNORE:
+		spin_unlock_bh(&ct->lock);
+		return NF_ACCEPT;
+	case NFCT_TCP_INVALID:
+		nf_tcp_handle_invalid(ct, dir, index, skb, state);
 		spin_unlock_bh(&ct->lock);
 		return -NF_ACCEPT;
+	case NFCT_TCP_ACCEPT:
+		break;
 	}
      in_window:
 	/* From now on we have got in-window packets */

net/netfilter/nf_log.c

···
 		mutex_lock(&nf_log_mutex);
 		logger = nft_log_dereference(net->nf.nf_loggers[tindex]);
 		if (!logger)
-			strlcpy(buf, "NONE", sizeof(buf));
+			strscpy(buf, "NONE", sizeof(buf));
 		else
-			strlcpy(buf, logger->name, sizeof(buf));
+			strscpy(buf, logger->name, sizeof(buf));
 		mutex_unlock(&nf_log_mutex);
 		r = proc_dostring(&tmp, write, buffer, lenp, ppos);
 	}

net/netfilter/nf_nat_amanda.c

···
 	exp->expectfn = nf_nat_follow_master;
 
 	/* Try to get same port: if not, try to change it. */
-	for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
-		int res;
-
-		exp->tuple.dst.u.tcp.port = htons(port);
-		res = nf_ct_expect_related(exp, 0);
-		if (res == 0)
-			break;
-		else if (res != -EBUSY) {
-			port = 0;
-			break;
-		}
-	}
-
+	port = nf_nat_exp_find_port(exp, ntohs(exp->saved_proto.tcp.port));
 	if (port == 0) {
 		nf_ct_helper_log(skb, exp->master, "all ports in use");
 		return NF_DROP;

net/netfilter/nf_nat_ftp.c

···
 	 * this one. */
 	exp->expectfn = nf_nat_follow_master;
 
-	/* Try to get same port: if not, try to change it. */
-	for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
-		int ret;
-
-		exp->tuple.dst.u.tcp.port = htons(port);
-		ret = nf_ct_expect_related(exp, 0);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			port = 0;
-			break;
-		}
-	}
-
+	port = nf_nat_exp_find_port(exp, ntohs(exp->saved_proto.tcp.port));
 	if (port == 0) {
-		nf_ct_helper_log(skb, ct, "all ports in use");
+		nf_ct_helper_log(skb, exp->master, "all ports in use");
 		return NF_DROP;
 	}
 

net/netfilter/nf_nat_helper.c

···
 	nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST);
 }
 EXPORT_SYMBOL(nf_nat_follow_master);
+
+u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port)
+{
+	static const unsigned int max_attempts = 128;
+	int range, attempts_left;
+	u16 min = port;
+
+	range = USHRT_MAX - port;
+	attempts_left = range;
+
+	if (attempts_left > max_attempts)
+		attempts_left = max_attempts;
+
+	/* Try to get same port: if not, try to change it. */
+	for (;;) {
+		int res;
+
+		exp->tuple.dst.u.tcp.port = htons(port);
+		res = nf_ct_expect_related(exp, 0);
+		if (res == 0)
+			return port;
+
+		if (res != -EBUSY || (--attempts_left < 0))
+			break;
+
+		port = min + prandom_u32_max(range);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_nat_exp_find_port);

net/netfilter/nf_nat_irc.c

···
 	exp->dir = IP_CT_DIR_REPLY;
 	exp->expectfn = nf_nat_follow_master;
 
-	/* Try to get same port: if not, try to change it. */
-	for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
-		int ret;
-
-		exp->tuple.dst.u.tcp.port = htons(port);
-		ret = nf_ct_expect_related(exp, 0);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			port = 0;
-			break;
-		}
-	}
-
+	port = nf_nat_exp_find_port(exp,
+				    ntohs(exp->saved_proto.tcp.port));
 	if (port == 0) {
 		nf_ct_helper_log(skb, ct, "all ports in use");
 		return NF_DROP;

net/netfilter/nf_nat_sip.c

···
 	exp->dir = !dir;
 	exp->expectfn = nf_nat_sip_expected;
 
-	for (; port != 0; port++) {
-		int ret;
-
-		exp->tuple.dst.u.udp.port = htons(port);
-		ret = nf_ct_expect_related(exp, NF_CT_EXP_F_SKIP_MASTER);
-		if (ret == 0)
-			break;
-		else if (ret != -EBUSY) {
-			port = 0;
-			break;
-		}
-	}
-
+	port = nf_nat_exp_find_port(exp, port);
 	if (port == 0) {
 		nf_ct_helper_log(skb, ct, "all ports in use for SIP");
 		return NF_DROP;

net/netfilter/nf_tables_api.c

···
 		return -ENOMEM;
 
 	req->done = false;
-	strlcpy(req->module, module_name, MODULE_NAME_LEN);
+	strscpy(req->module, module_name, MODULE_NAME_LEN);
 	list_add_tail(&req->list, &nft_net->module_list);
 
 	return -EAGAIN;

net/netfilter/nft_osf.c

···
 			snprintf(os_match, NFT_OSF_MAXGENRELEN, "%s:%s",
 				 data.genre, data.version);
 		else
-			strlcpy(os_match, data.genre, NFT_OSF_MAXGENRELEN);
+			strscpy(os_match, data.genre, NFT_OSF_MAXGENRELEN);
 
 		strncpy((char *)dest, os_match, NFT_OSF_MAXGENRELEN);
 	}

net/netfilter/x_tables.c

···
 
 	msize += off;
 	m->u.user.match_size = msize;
-	strlcpy(name, match->name, sizeof(name));
+	strscpy(name, match->name, sizeof(name));
 	module_put(match->me);
 	strncpy(m->u.user.name, name, sizeof(m->u.user.name));
 
···
 
 	tsize += off;
 	t->u.user.target_size = tsize;
-	strlcpy(name, target->name, sizeof(name));
+	strscpy(name, target->name, sizeof(name));
 	module_put(target->me);
 	strncpy(t->u.user.name, name, sizeof(t->u.user.name));
 
···
 	root_uid = make_kuid(net->user_ns, 0);
 	root_gid = make_kgid(net->user_ns, 0);
 
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_TABLES, sizeof(buf));
 	proc = proc_create_net_data(buf, 0440, net->proc_net, &xt_table_seq_ops,
 			sizeof(struct seq_net_private),
···
 	if (uid_valid(root_uid) && gid_valid(root_gid))
 		proc_set_user(proc, root_uid, root_gid);
 
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 	proc = proc_create_seq_private(buf, 0440, net->proc_net,
 			&xt_match_seq_ops, sizeof(struct nf_mttg_trav),
···
 	if (uid_valid(root_uid) && gid_valid(root_gid))
 		proc_set_user(proc, root_uid, root_gid);
 
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 	proc = proc_create_seq_private(buf, 0440, net->proc_net,
 			 &xt_target_seq_ops, sizeof(struct nf_mttg_trav),
···
 
 #ifdef CONFIG_PROC_FS
 out_remove_matches:
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 	remove_proc_entry(buf, net->proc_net);
 
 out_remove_tables:
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_TABLES, sizeof(buf));
 	remove_proc_entry(buf, net->proc_net);
 out:
···
 #ifdef CONFIG_PROC_FS
 	char buf[XT_FUNCTION_MAXNAMELEN];
 
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_TABLES, sizeof(buf));
 	remove_proc_entry(buf, net->proc_net);
 
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_TARGETS, sizeof(buf));
 	remove_proc_entry(buf, net->proc_net);
 
-	strlcpy(buf, xt_prefix[af], sizeof(buf));
+	strscpy(buf, xt_prefix[af], sizeof(buf));
 	strlcat(buf, FORMAT_MATCHES, sizeof(buf));
 	remove_proc_entry(buf, net->proc_net);
 #endif /*CONFIG_PROC_FS*/

net/netfilter/xt_RATEEST.c

···
 		goto err1;
 
 	gnet_stats_basic_sync_init(&est->bstats);
-	strlcpy(est->name, info->name, sizeof(est->name));
+	strscpy(est->name, info->name, sizeof(est->name));
 	spin_lock_init(&est->lock);
 	est->refcnt		= 1;
 	est->params.interval	= info->interval;