[PATCH net-next v2 0/2] gtp: simple gtp improvements

[PATCH net-next v2 0/2] gtp: simple gtp improvements

[Andreas Schultz]

This is the part of the previous "simple gtp improvements" series
that Pablo indicated should go into net-next.

The rcu_lock removal is small correctness changes. Passing invalid
to user space allows for more standards compliant handling of invalid
tunnels.

[PATCH net-next v2 1/2] gtp: remove unnecessary rcu_read_lock

[Andreas Schultz]

The rcu read lock is hold by default in the ip input path. There
is no need to hold it twice in the socket recv decapsulate code path.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 24 ++++--------------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 8b6810b..5c63a37 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -184,7 +184,6 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 			      sizeof(struct gtp0_header);
 	struct gtp0_header *gtp0;
 	struct pdp_ctx *pctx;
-	int ret = 0;
 
 	if (!pskb_may_pull(skb, hdrlen))
 		return -1;
@@ -197,26 +196,19 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 	if (gtp0->type != GTP_TPDU)
 		return 1;
 
-	rcu_read_lock();
 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
 	if (!pctx) {
 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
-		ret = -1;
-		goto out_rcu;
+		return -1;
 	}
 
 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-		ret = -1;
-		goto out_rcu;
+		return -1;
 	}
-	rcu_read_unlock();
 
 	/* Get rid of the GTP + UDP headers. */
 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
-out_rcu:
-	rcu_read_unlock();
-	return ret;
 }
 
 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
@@ -226,7 +218,6 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 			      sizeof(struct gtp1_header);
 	struct gtp1_header *gtp1;
 	struct pdp_ctx *pctx;
-	int ret = 0;
 
 	if (!pskb_may_pull(skb, hdrlen))
 		return -1;
@@ -254,26 +245,19 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 
 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
 
-	rcu_read_lock();
 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
 	if (!pctx) {
 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
-		ret = -1;
-		goto out_rcu;
+		return -1;
 	}
 
 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-		ret = -1;
-		goto out_rcu;
+		return -1;
 	}
-	rcu_read_unlock();
 
 	/* Get rid of the GTP + UDP headers. */
 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
-out_rcu:
-	rcu_read_unlock();
-	return ret;
 }
 
 static void gtp_encap_disable(struct gtp_dev *gtp)
-- 
2.10.2

[PATCH net-next v2 2/2] gtp: let userspace handle packets for invalid tunnels

[Andreas Schultz]

enable userspace to send error replies for invalid tunnels

Acked-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 5c63a37..5dd7de6 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -199,12 +199,12 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
 	if (!pctx) {
 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
-		return -1;
+		return 1;
 	}
 
 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-		return -1;
+		return 1;
 	}
 
 	/* Get rid of the GTP + UDP headers. */
@@ -248,12 +248,12 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
 	if (!pctx) {
 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
-		return -1;
+		return 1;
 	}
 
 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-		return -1;
+		return 1;
 	}
 
 	/* Get rid of the GTP + UDP headers. */
-- 
2.10.2

Re: [PATCH net-next v2 0/2] gtp: simple gtp improvements

[David Miller]

From: Andreas Schultz <aschultz@tpip.net>
Date: Thu, 26 Jan 2017 16:21:47 +0100

> This is the part of the previous "simple gtp improvements" series
> that Pablo indicated should go into net-next.
> 
> The rcu_lock removal is small correctness changes. Passing invalid
> to user space allows for more standards compliant handling of invalid
> tunnels.

Series applied, thanks.