tcp: Revert no longer abort SYN_SENT when receiving some ICMP

This reverts commit 0a8de36.

Shachar reported that Vagrant (https://www.vagrantup.com/), which is
very popular tool to manage fleet of VMs stopped to work after commit
citied in Fixes line.

The issue appears while using Vagrant to manage nested VMs.
The steps are:
* create vagrant file
* vagrant up
* vagrant halt (VM is created but shut down)
* vagrant up - fail

Vagrant up stdout:
Bringing machine 'player1' up with 'libvirt' provider...
==> player1: Creating shared folders metadata...
==> player1: Starting domain.
==> player1: Domain launching with graphics connection settings...
==> player1:  -- Graphics Port:      5900
==> player1:  -- Graphics IP:        127.0.0.1
==> player1:  -- Graphics Password:  Not defined
==> player1:  -- Graphics Websocket: 5700
==> player1: Waiting for domain to get an IP address...
==> player1: Waiting for machine to boot. This may take a few minutes...
    player1: SSH address: 192.168.123.61:22
    player1: SSH username: vagrant
    player1: SSH auth method: private key
==> player1: Attempting graceful shutdown of VM...
==> player1: Attempting graceful shutdown of VM...
==> player1: Attempting graceful shutdown of VM...
    player1: Guest communication could not be established! This is usually because
    player1: SSH is not running, the authentication information was changed,
    player1: or some other networking issue. Vagrant will force halt, if
    player1: capable.
==> player1: Attempting direct shutdown of domain...

Fixes: 0a8de36 ("tcp: no longer abort SYN_SENT when receiving some ICMP")
Closes: https://lore.kernel.org/all/MN2PR12MB44863139E562A59329E89DBEB982A@MN2PR12MB4486.namprd12.prod.outlook.com
Signed-off-by: Shachar Kagan <skagan@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/14459261ea9f9c7d7dfb28eb004ce8734fa83ade.1704185904.git.leonro@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: ShacharKagan

net/ipv4/tcp_ipv4.c

@@ -482,7 +482,6 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
 	const int code = icmp_hdr(skb)->code;
 	struct sock *sk;
 	struct request_sock *fastopen;
-	bool harderr = false;
 	u32 seq, snd_una;
 	int err;
 	struct net *net = dev_net(skb->dev);
@@ -556,7 +555,6 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
 		goto out;
 	case ICMP_PARAMETERPROB:
 		err = EPROTO;
-		harderr = true;
 		break;
 	case ICMP_DEST_UNREACH:
 		if (code > NR_ICMP_UNREACH)
@@ -581,7 +579,6 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
 		}
 
 		err = icmp_err_convert[code].errno;
-		harderr = icmp_err_convert[code].fatal;
 		/* check if this ICMP message allows revert of backoff.
 		 * (see RFC 6069)
 		 */
@@ -607,9 +604,6 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
 
 		ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th);
 
-		if (!harderr)
-			break;
-
 		if (!sock_owned_by_user(sk)) {
 			WRITE_ONCE(sk->sk_err, err);
 

net/ipv6/tcp_ipv6.c

@@ -381,7 +381,7 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	struct tcp_sock *tp;
 	__u32 seq, snd_una;
 	struct sock *sk;
-	bool harderr;
+	bool fatal;
 	int err;
 
 	sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
@@ -402,9 +402,9 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		return 0;
 	}
 	seq = ntohl(th->seq);
-	harderr = icmpv6_err_convert(type, code, &err);
+	fatal = icmpv6_err_convert(type, code, &err);
 	if (sk->sk_state == TCP_NEW_SYN_RECV) {
-		tcp_req_err(sk, seq, harderr);
+		tcp_req_err(sk, seq, fatal);
 		return 0;
 	}
 
@@ -489,9 +489,6 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 
 		ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
 
-		if (!harderr)
-			break;
-
 		if (!sock_owned_by_user(sk)) {
 			WRITE_ONCE(sk->sk_err, err);
 			sk_error_report(sk);		/* Wake people up to see the error (see connect in sock.c) */