| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20130922053800.GA4890@verge.net.au>
Date: Sun, 22 Sep 2013 14:38:00 +0900
From: Simon Horman <horms@...ge.net.au>
To: Jesse Gross <jesse@...ira.com>
Cc: Pravin Shelar <pshelar@...ira.com>,
"dev@...nvswitch.org" <dev@...nvswitch.org>,
netdev <netdev@...r.kernel.org>, Ravi K <rkerur@...il.com>,
Isaku Yamahata <yamahata@...inux.co.jp>,
Joe Stringer <joe@...d.net.nz>
Subject: Re: [PATCH v2.39 7/7] datapath: Add basic MPLS support to kernel
On Thu, Sep 19, 2013 at 12:31:51PM -0500, Jesse Gross wrote:
> On Wed, Sep 18, 2013 at 5:07 PM, Simon Horman <horms@...ge.net.au> wrote:
> > On Tue, Sep 17, 2013 at 11:38:18AM -0700, Pravin Shelar wrote:
> >> On Mon, Sep 9, 2013 at 12:20 AM, Simon Horman <horms@...ge.net.au> wrote:
> >> > diff --git a/datapath/datapath.h b/datapath/datapath.h
> >> > index 5d50dd4..babae3b 100644
> >> > --- a/datapath/datapath.h
> >> > +++ b/datapath/datapath.h
> >> > @@ -36,6 +36,10 @@
> >> >
> >> > #define SAMPLE_ACTION_DEPTH 3
> >> >
> >> > +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,11,0)
> >> > +#define HAVE_INNER_PROTOCOL
> >> > +#endif
> >> > +
> >> > /**
> >> > * struct dp_stats_percpu - per-cpu packet processing statistics for a given
> >> > * datapath.
> >> > @@ -93,11 +97,16 @@ struct datapath {
> >> > * @pkt_key: The flow information extracted from the packet. Must be nonnull.
> >> > * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
> >> > * packet is not being tunneled.
> >> > + * @inner_protocol: Provides a substitute for the skb->inner_protocol field on
> >> > + * kernels before 3.11.
> >> > */
> >> > struct ovs_skb_cb {
> >> > struct sw_flow *flow;
> >> > struct sw_flow_key *pkt_key;
> >> > struct ovs_key_ipv4_tunnel *tun_key;
> >> > +#ifndef HAVE_INNER_PROTOCOL
> >> > + __be16 inner_protocol;
> >> > +#endif
> >> > };
> >> > #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
> >> >
> >> Can you move this to compat struct ovs_gso_cb {}
> >
> > I think that you are correct and inner_protocol needs
> > to be in struct ovs_gso_cb so that it can
> > be accessed via skb_network_protocol() from
> > rpl___skb_gso_segment().
> >
> > However I think it may also need to be present in struct ovs_cb
> > so that it can be set correctly.
> >
> > Currently it is set unconditionally
> > in ovs_execute_actions() and Jesse has suggested setting
> > it conditionally in pop_mpls() (which is called by do_execute_actions()).
> > But regardless it seems to me that the field would need to be available
> > in struct ovs_cb.
>
> Since the helper functions are also in the compat code, I think they
> should have access to ovs_gso_cb.
Pravin also believes that is the case so I have moved inner_protocol
to struct ovs_gso_cb as he requested.
> >> I think we can simplify code by pushing vlan and then segmenting skb,
> >> the way we do it for MPLS.
> >
> > Are you thinking of something like the following which applies
> > prior to the MPLS code.
>
> This is basically what I was thinking about. We might actually be able
> to move all of this to compat code by having a replacement for
> dev_queue_xmit() similar to what we have for ip_local_out() in the
> tunnel code.
I would appreciate Pravin's opinion on this but it seems to me
that it should be possible.
The following applies on top of my previous proposed change
in this thread - simplification of segmentation - and before
the MPLS patch-set. Is this along the lines of what you were
thinking of?
From: Simon Horman <horms@...ge.net.au>
datapath: Move segmentation compatibility code into a compatibility function
*** Do not apply: for informational purposes only
Move segmentation compatibility code out of netdev_send and into
rpl_dev_queue_xmit(), a compatibility function used in place
of dev_queue_xmit() as necessary.
As suggested by Jesse Gross.
Some minor though verbose implementation notes:
* This rpl_dev_queue_xmit() endeavours to return a valid error code or
zero on success as per dev_queue_xmit(). The exception is that when
dev_queue_xmit() is called in a loop only the status of the last call is
taken into account, thus ignoring any errors returned by previous calls.
This is derived from the previous calls to dev_queue_xmit() in a loop
where netdev_send() ignores the return value of dev_queue_xmit()
entirely.
* netdev_send() continues to ignore the value of dev_queue_xmit().
So the discussion of the return value of rpl_dev_queue_xmit()
above is has no bearing on run-time behaviour.
* The return value of netdev_send() may differ from the previous
implementation in the case where segmentation is performed before
calling the real dev_queue_xmit(). This is because previously in
this case netdev_send() would return the combined length of the
skbs resulting from segmentation. Whereas the current code
always returns the length of the original skb.
Compile tested only.
Signed-off-by: Simon Horman <horms@...ge.net.au>
---
datapath/linux/compat/gso.c | 80 +++++++++++++++++++++++++++++++++++++++++++++
datapath/linux/compat/gso.h | 5 +++
datapath/vport-netdev.c | 78 ++-----------------------------------------
3 files changed, 87 insertions(+), 76 deletions(-)
diff --git a/datapath/linux/compat/gso.c b/datapath/linux/compat/gso.c
index 30332a2..d7e92fb 100644
--- a/datapath/linux/compat/gso.c
+++ b/datapath/linux/compat/gso.c
@@ -36,6 +36,86 @@
#include "gso.h"
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37) && \
+ !defined(HAVE_VLAN_BUG_WORKAROUND)
+#include <linux/module.h>
+
+static int vlan_tso __read_mostly;
+module_param(vlan_tso, int, 0644);
+MODULE_PARM_DESC(vlan_tso, "Enable TSO for VLAN packets");
+#else
+#define vlan_tso true
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
+static bool dev_supports_vlan_tx(struct net_device *dev)
+{
+#if defined(HAVE_VLAN_BUG_WORKAROUND)
+ return dev->features & NETIF_F_HW_VLAN_TX;
+#else
+ /* Assume that the driver is buggy. */
+ return false;
+#endif
+}
+
+int rpl_dev_queue_xmit(struct sk_buff *skb)
+{
+#undef dev_queue_xmit
+ int err = -ENOMEM;
+
+ if (vlan_tx_tag_present(skb) && !dev_supports_vlan_tx(skb->dev)) {
+ int features;
+
+ features = netif_skb_features(skb);
+
+ if (!vlan_tso)
+ features &= ~(NETIF_F_TSO | NETIF_F_TSO6 |
+ NETIF_F_UFO | NETIF_F_FSO);
+
+ skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb));
+ if (unlikely(!skb))
+ return err;
+ vlan_set_tci(skb, 0);
+
+ if (netif_needs_gso(skb, features)) {
+ struct sk_buff *nskb;
+
+ nskb = skb_gso_segment(skb, features);
+ if (!nskb) {
+ if (unlikely(skb_cloned(skb) &&
+ pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+ goto drop;
+
+ skb_shinfo(skb)->gso_type &= ~SKB_GSO_DODGY;
+ goto xmit;
+ }
+
+ if (IS_ERR(nskb)) {
+ err = PTR_ERR(nskb);
+ goto drop;
+ }
+ consume_skb(skb);
+ skb = nskb;
+
+ do {
+ nskb = skb->next;
+ skb->next = NULL;
+ err = dev_queue_xmit(skb);
+ skb = nskb;
+ } while (skb);
+
+ return err;
+ }
+ }
+xmit:
+ return dev_queue_xmit(skb);
+
+drop:
+ kfree_skb(skb);
+ return err;
+}
+#endif /* kernel version < 3.6.37 */
+
static __be16 __skb_network_protocol(struct sk_buff *skb)
{
__be16 type = skb->protocol;
diff --git a/datapath/linux/compat/gso.h b/datapath/linux/compat/gso.h
index 44fd213..af1aaed 100644
--- a/datapath/linux/compat/gso.h
+++ b/datapath/linux/compat/gso.h
@@ -69,4 +69,9 @@ static inline void skb_reset_inner_headers(struct sk_buff *skb)
#define ip_local_out rpl_ip_local_out
int ip_local_out(struct sk_buff *skb);
+
+#if 1 // LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
+#define dev_queue_xmit rpl_dev_queue_xmit
+#endif
+
#endif
diff --git a/datapath/vport-netdev.c b/datapath/vport-netdev.c
index 31680fd..4d934b5 100644
--- a/datapath/vport-netdev.c
+++ b/datapath/vport-netdev.c
@@ -34,17 +34,6 @@
#include "vport-internal_dev.h"
#include "vport-netdev.h"
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37) && \
- !defined(HAVE_VLAN_BUG_WORKAROUND)
-#include <linux/module.h>
-
-static int vlan_tso __read_mostly;
-module_param(vlan_tso, int, 0644);
-MODULE_PARM_DESC(vlan_tso, "Enable TSO for VLAN packets");
-#else
-#define vlan_tso true
-#endif
-
static void netdev_port_receive(struct vport *vport, struct sk_buff *skb);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,39)
@@ -259,19 +248,6 @@ static unsigned int packet_length(const struct sk_buff *skb)
return length;
}
-static bool dev_supports_vlan_tx(struct net_device *dev)
-{
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,37)
- /* Software fallback means every device supports vlan_tci on TX. */
- return true;
-#elif defined(HAVE_VLAN_BUG_WORKAROUND)
- return dev->features & NETIF_F_HW_VLAN_TX;
-#else
- /* Assume that the driver is buggy. */
- return false;
-#endif
-}
-
static int netdev_send(struct vport *vport, struct sk_buff *skb)
{
struct netdev_vport *netdev_vport = netdev_vport_priv(vport);
@@ -282,65 +258,15 @@ static int netdev_send(struct vport *vport, struct sk_buff *skb)
net_warn_ratelimited("%s: dropped over-mtu packet: %d > %d\n",
netdev_vport->dev->name,
packet_length(skb), mtu);
- goto drop;
+ kfree_skb(skb);
+ return 0;
}
skb->dev = netdev_vport->dev;
-
- if (vlan_tx_tag_present(skb) && !dev_supports_vlan_tx(skb->dev)) {
- int features;
-
- features = netif_skb_features(skb);
-
- if (!vlan_tso)
- features &= ~(NETIF_F_TSO | NETIF_F_TSO6 |
- NETIF_F_UFO | NETIF_F_FSO);
-
- skb = __vlan_put_tag(skb, skb->vlan_proto, vlan_tx_tag_get(skb));
- if (unlikely(!skb))
- return 0;
- vlan_set_tci(skb, 0);
-
- if (netif_needs_gso(skb, features)) {
- struct sk_buff *nskb;
-
- nskb = skb_gso_segment(skb, features);
- if (!nskb) {
- if (unlikely(skb_cloned(skb) &&
- pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
- goto drop;
-
- skb_shinfo(skb)->gso_type &= ~SKB_GSO_DODGY;
- goto xmit;
- }
-
- if (IS_ERR(nskb))
- goto drop;
- consume_skb(skb);
- skb = nskb;
-
- len = 0;
- do {
- nskb = skb->next;
- skb->next = NULL;
- len += skb->len;
- dev_queue_xmit(skb);
- skb = nskb;
- } while (skb);
-
- return len;
- }
- }
-
-xmit:
len = skb->len;
dev_queue_xmit(skb);
return len;
-
-drop:
- kfree_skb(skb);
- return 0;
}
/* Returns null if this device is not attached to a datapath. */
--
1.8.4
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists