[20/33] ipv4: add ip_sock_set_recverr
diff mbox series

Message ID 20200513062649.2100053-21-hch@lst.de
State New
Headers show
Series
  • [01/33] net: add sock_set_reuseaddr
Related show

Commit Message

Christoph Hellwig May 13, 2020, 6:26 a.m. UTC
Add a helper to directly set the IP_RECVERR sockopt from kernel space
without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/net/ip.h         |  1 +
 net/ipv4/ip_sockglue.c   | 10 ++++++++++
 net/rxrpc/local_object.c |  8 +-------
 3 files changed, 12 insertions(+), 7 deletions(-)

Comments

David Howells May 13, 2020, 1:24 p.m. UTC | #1
Christoph Hellwig <hch@lst.de> wrote:

> Add a helper to directly set the IP_RECVERR sockopt from kernel space
> without going through a fake uaccess.

It looks like if this is an AF_INET6 socket, it will just pass the message
straight through to AF_INET4, so:

Reviewed-by: David Howells <dhowells@redhat.com>
Joe Perches May 13, 2020, 9 p.m. UTC | #2
On Wed, 2020-05-13 at 08:26 +0200, Christoph Hellwig wrote:
> Add a helper to directly set the IP_RECVERR sockopt from kernel space
> without going through a fake uaccess.

This seems used only with true as the second arg.
Is there reason to have that argument at all?

> diff --git a/include/net/ip.h b/include/net/ip.h
[]
> @@ -767,5 +767,6 @@ static inline bool inetdev_valid_mtu(unsigned int mtu)
>  
>  void ip_sock_set_tos(struct sock *sk, int val);
>  void ip_sock_set_freebind(struct sock *sk, bool val);
> +void ip_sock_set_recverr(struct sock *sk, bool val);
>  
>  #endif	/* _IP_H */
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 0c40887a817f8..9abecc3195520 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -589,6 +589,16 @@ void ip_sock_set_freebind(struct sock *sk, bool val)
>  }
>  EXPORT_SYMBOL(ip_sock_set_freebind);
>  
> +void ip_sock_set_recverr(struct sock *sk, bool val)
> +{
> +	lock_sock(sk);
> +	inet_sk(sk)->recverr = val;
> +	if (!val)
> +		skb_queue_purge(&sk->sk_error_queue);
> +	release_sock(sk);
> +}
> +EXPORT_SYMBOL(ip_sock_set_recverr);
> +
>  /*
>   *	Socket option code for IP. This is the end of the line after any
>   *	TCP,UDP etc options on an IP socket.
> diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
> index 562ea36c96b0f..1b87b8a9ff725 100644
> --- a/net/rxrpc/local_object.c
> +++ b/net/rxrpc/local_object.c
> @@ -171,13 +171,7 @@ static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
>  		/* Fall through */
>  	case AF_INET:
>  		/* we want to receive ICMP errors */
> -		opt = 1;
> -		ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
> -					(char *) &opt, sizeof(opt));
> -		if (ret < 0) {
> -			_debug("setsockopt failed");
> -			goto error;
> -		}
> +		ip_sock_set_recverr(local->socket->sk, true);
>  
>  		/* we want to set the don't fragment bit */
>  		opt = IP_PMTUDISC_DO;
Christoph Hellwig May 14, 2020, 10:30 a.m. UTC | #3
On Wed, May 13, 2020 at 02:00:43PM -0700, Joe Perches wrote:
> On Wed, 2020-05-13 at 08:26 +0200, Christoph Hellwig wrote:
> > Add a helper to directly set the IP_RECVERR sockopt from kernel space
> > without going through a fake uaccess.
> 
> This seems used only with true as the second arg.
> Is there reason to have that argument at all?

Mostly to keep it symmetric with the sockopt.  I could probably remove
a few arguments in the series if we want to be strict.
Joe Perches May 14, 2020, 11:51 a.m. UTC | #4
On Thu, 2020-05-14 at 12:30 +0200, Christoph Hellwig wrote:
> On Wed, May 13, 2020 at 02:00:43PM -0700, Joe Perches wrote:
> > On Wed, 2020-05-13 at 08:26 +0200, Christoph Hellwig wrote:
> > > Add a helper to directly set the IP_RECVERR sockopt from kernel space
> > > without going through a fake uaccess.
> > 
> > This seems used only with true as the second arg.
> > Is there reason to have that argument at all?
> 
> Mostly to keep it symmetric with the sockopt.  I could probably remove
> a few arguments in the series if we want to be strict.

My preference would use strict and add
arguments only when necessary.
Christoph Hellwig May 20, 2020, 2:18 p.m. UTC | #5
On Thu, May 14, 2020 at 04:51:26AM -0700, Joe Perches wrote:
> > Mostly to keep it symmetric with the sockopt.  I could probably remove
> > a few arguments in the series if we want to be strict.
> 
> My preference would use strict and add
> arguments only when necessary.

In a few cases that would create confusion as the arguments are rather
overloaded.  But for a lot of the cases where it doesn't and there isn't
really much use for other arguments I've done that now.

Patch
diff mbox series

diff --git a/include/net/ip.h b/include/net/ip.h
index 1e2feca8630d0..7ab8140b54429 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -767,5 +767,6 @@  static inline bool inetdev_valid_mtu(unsigned int mtu)
 
 void ip_sock_set_tos(struct sock *sk, int val);
 void ip_sock_set_freebind(struct sock *sk, bool val);
+void ip_sock_set_recverr(struct sock *sk, bool val);
 
 #endif	/* _IP_H */
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 0c40887a817f8..9abecc3195520 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -589,6 +589,16 @@  void ip_sock_set_freebind(struct sock *sk, bool val)
 }
 EXPORT_SYMBOL(ip_sock_set_freebind);
 
+void ip_sock_set_recverr(struct sock *sk, bool val)
+{
+	lock_sock(sk);
+	inet_sk(sk)->recverr = val;
+	if (!val)
+		skb_queue_purge(&sk->sk_error_queue);
+	release_sock(sk);
+}
+EXPORT_SYMBOL(ip_sock_set_recverr);
+
 /*
  *	Socket option code for IP. This is the end of the line after any
  *	TCP,UDP etc options on an IP socket.
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
index 562ea36c96b0f..1b87b8a9ff725 100644
--- a/net/rxrpc/local_object.c
+++ b/net/rxrpc/local_object.c
@@ -171,13 +171,7 @@  static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
 		/* Fall through */
 	case AF_INET:
 		/* we want to receive ICMP errors */
-		opt = 1;
-		ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
-					(char *) &opt, sizeof(opt));
-		if (ret < 0) {
-			_debug("setsockopt failed");
-			goto error;
-		}
+		ip_sock_set_recverr(local->socket->sk, true);
 
 		/* we want to set the don't fragment bit */
 		opt = IP_PMTUDISC_DO;