diff mbox series

[v6,net-next,1/9] ipeh: Fix destopts and hopopts counters on drop

Message ID 1576885124-14576-2-git-send-email-tom@herbertland.com
State Superseded
Delegated to: David Miller
Headers show
Series ipv6: Extension header infrastructure | expand

Commit Message

Tom Herbert Dec. 20, 2019, 11:38 p.m. UTC 
From: Tom Herbert <tom@quantonium.net>

For destopts, bump IPSTATS_MIB_INHDRERRORS when limit of length
of extension header is exceeded.

For hop-by-hop options, bump IPSTATS_MIB_INHDRERRORS in same
situations as for when destopts are dropped.

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 net/ipv6/exthdrs.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Willem de Bruijn Dec. 22, 2019, 4:20 p.m. UTC | #1 
On Fri, Dec 20, 2019 at 6:39 PM Tom Herbert <tom@herbertland.com> wrote:
>
> From: Tom Herbert <tom@quantonium.net>
>
> For destopts, bump IPSTATS_MIB_INHDRERRORS when limit of length
> of extension header is exceeded.
>
> For hop-by-hop options, bump IPSTATS_MIB_INHDRERRORS in same
> situations as for when destopts are dropped.
>
> Signed-off-by: Tom Herbert <tom@herbertland.com>
> ---
>  net/ipv6/exthdrs.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
> index ab5add0..f605e4e 100644
> --- a/net/ipv6/exthdrs.c
> +++ b/net/ipv6/exthdrs.c
> @@ -288,9 +288,9 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
>         if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
>             !pskb_may_pull(skb, (skb_transport_offset(skb) +
>                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> +fail_and_free:
>                 __IP6_INC_STATS(dev_net(dst->dev), idev,
>                                 IPSTATS_MIB_INHDRERRORS);
> -fail_and_free:
>                 kfree_skb(skb);
>                 return -1;
>         }
> @@ -820,8 +820,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
>
>  int ipv6_parse_hopopts(struct sk_buff *skb)
>  {
> +       struct inet6_dev *idev = __in6_dev_get(skb->dev);
>         struct inet6_skb_parm *opt = IP6CB(skb);
>         struct net *net = dev_net(skb->dev);
> +       struct dst_entry *dst = skb_dst(skb);
>         int extlen;
>
>         /*
> @@ -834,6 +836,8 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
>             !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
>                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
>  fail_and_free:
> +               __IP6_INC_STATS(dev_net(dst->dev), idev,
> +                               IPSTATS_MIB_INHDRERRORS);

ip6_rcv_core, the only caller of ipv6_parse_hopopts, checks
skb_valid_dst(skb) before deref. Does this need the same?
Tom Herbert Dec. 23, 2019, 4:53 p.m. UTC | #2 
On Sun, Dec 22, 2019 at 8:21 AM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Fri, Dec 20, 2019 at 6:39 PM Tom Herbert <tom@herbertland.com> wrote:
> >
> > From: Tom Herbert <tom@quantonium.net>
> >
> > For destopts, bump IPSTATS_MIB_INHDRERRORS when limit of length
> > of extension header is exceeded.
> >
> > For hop-by-hop options, bump IPSTATS_MIB_INHDRERRORS in same
> > situations as for when destopts are dropped.
> >
> > Signed-off-by: Tom Herbert <tom@herbertland.com>
> > ---
> >  net/ipv6/exthdrs.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
> > index ab5add0..f605e4e 100644
> > --- a/net/ipv6/exthdrs.c
> > +++ b/net/ipv6/exthdrs.c
> > @@ -288,9 +288,9 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
> >         if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
> >             !pskb_may_pull(skb, (skb_transport_offset(skb) +
> >                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> > +fail_and_free:
> >                 __IP6_INC_STATS(dev_net(dst->dev), idev,
> >                                 IPSTATS_MIB_INHDRERRORS);
> > -fail_and_free:
> >                 kfree_skb(skb);
> >                 return -1;
> >         }
> > @@ -820,8 +820,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
> >
> >  int ipv6_parse_hopopts(struct sk_buff *skb)
> >  {
> > +       struct inet6_dev *idev = __in6_dev_get(skb->dev);
> >         struct inet6_skb_parm *opt = IP6CB(skb);
> >         struct net *net = dev_net(skb->dev);
> > +       struct dst_entry *dst = skb_dst(skb);
> >         int extlen;
> >
> >         /*
> > @@ -834,6 +836,8 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
> >             !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
> >                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> >  fail_and_free:
> > +               __IP6_INC_STATS(dev_net(dst->dev), idev,
> > +                               IPSTATS_MIB_INHDRERRORS);
>
> ip6_rcv_core, the only caller of ipv6_parse_hopopts, checks
> skb_valid_dst(skb) before deref. Does this need the same?

Hi Willem,

Actually, it looks like ipv6_parse_hopopts is doing things the right
way. __IP6_INC_STATS is called from ip6_rcv_core if ipv6_parse_hopopts
and the net is always taken from skb->dev (not dst) in HBH path. I'll
fix destopts to do the same.

Tom
Willem de Bruijn Dec. 23, 2019, 6:52 p.m. UTC | #3 
On Mon, Dec 23, 2019 at 11:53 AM Tom Herbert <tom@herbertland.com> wrote:
>
> On Sun, Dec 22, 2019 at 8:21 AM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Fri, Dec 20, 2019 at 6:39 PM Tom Herbert <tom@herbertland.com> wrote:
> > >
> > > From: Tom Herbert <tom@quantonium.net>
> > >
> > > For destopts, bump IPSTATS_MIB_INHDRERRORS when limit of length
> > > of extension header is exceeded.
> > >
> > > For hop-by-hop options, bump IPSTATS_MIB_INHDRERRORS in same
> > > situations as for when destopts are dropped.
> > >
> > > Signed-off-by: Tom Herbert <tom@herbertland.com>
> > > ---
> > >  net/ipv6/exthdrs.c | 7 ++++++-
> > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
> > > index ab5add0..f605e4e 100644
> > > --- a/net/ipv6/exthdrs.c
> > > +++ b/net/ipv6/exthdrs.c
> > > @@ -288,9 +288,9 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
> > >         if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
> > >             !pskb_may_pull(skb, (skb_transport_offset(skb) +
> > >                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> > > +fail_and_free:
> > >                 __IP6_INC_STATS(dev_net(dst->dev), idev,
> > >                                 IPSTATS_MIB_INHDRERRORS);
> > > -fail_and_free:
> > >                 kfree_skb(skb);
> > >                 return -1;
> > >         }
> > > @@ -820,8 +820,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
> > >
> > >  int ipv6_parse_hopopts(struct sk_buff *skb)
> > >  {
> > > +       struct inet6_dev *idev = __in6_dev_get(skb->dev);
> > >         struct inet6_skb_parm *opt = IP6CB(skb);
> > >         struct net *net = dev_net(skb->dev);
> > > +       struct dst_entry *dst = skb_dst(skb);
> > >         int extlen;
> > >
> > >         /*
> > > @@ -834,6 +836,8 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
> > >             !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
> > >                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> > >  fail_and_free:
> > > +               __IP6_INC_STATS(dev_net(dst->dev), idev,
> > > +                               IPSTATS_MIB_INHDRERRORS);
> >
> > ip6_rcv_core, the only caller of ipv6_parse_hopopts, checks
> > skb_valid_dst(skb) before deref. Does this need the same?
>
> Hi Willem,
>
> Actually, it looks like ipv6_parse_hopopts is doing things the right
> way. __IP6_INC_STATS is called from ip6_rcv_core if ipv6_parse_hopopts
> and the net is always taken from skb->dev (not dst) in HBH path. I'll
> fix destopts to do the same.

I don't entirely follow. The above code uses dev_net(dst->dev). Using
local variable net, derived from dev_net(skb->dev), here definitely
sounds good to me, if that's what you meant.
Tom Herbert Dec. 23, 2019, 8:02 p.m. UTC | #4 
On Mon, Dec 23, 2019 at 10:53 AM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Mon, Dec 23, 2019 at 11:53 AM Tom Herbert <tom@herbertland.com> wrote:
> >
> > On Sun, Dec 22, 2019 at 8:21 AM Willem de Bruijn
> > <willemdebruijn.kernel@gmail.com> wrote:
> > >
> > > On Fri, Dec 20, 2019 at 6:39 PM Tom Herbert <tom@herbertland.com> wrote:
> > > >
> > > > From: Tom Herbert <tom@quantonium.net>
> > > >
> > > > For destopts, bump IPSTATS_MIB_INHDRERRORS when limit of length
> > > > of extension header is exceeded.
> > > >
> > > > For hop-by-hop options, bump IPSTATS_MIB_INHDRERRORS in same
> > > > situations as for when destopts are dropped.
> > > >
> > > > Signed-off-by: Tom Herbert <tom@herbertland.com>
> > > > ---
> > > >  net/ipv6/exthdrs.c | 7 ++++++-
> > > >  1 file changed, 6 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
> > > > index ab5add0..f605e4e 100644
> > > > --- a/net/ipv6/exthdrs.c
> > > > +++ b/net/ipv6/exthdrs.c
> > > > @@ -288,9 +288,9 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
> > > >         if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
> > > >             !pskb_may_pull(skb, (skb_transport_offset(skb) +
> > > >                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> > > > +fail_and_free:
> > > >                 __IP6_INC_STATS(dev_net(dst->dev), idev,
> > > >                                 IPSTATS_MIB_INHDRERRORS);
> > > > -fail_and_free:
> > > >                 kfree_skb(skb);
> > > >                 return -1;
> > > >         }
> > > > @@ -820,8 +820,10 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
> > > >
> > > >  int ipv6_parse_hopopts(struct sk_buff *skb)
> > > >  {
> > > > +       struct inet6_dev *idev = __in6_dev_get(skb->dev);
> > > >         struct inet6_skb_parm *opt = IP6CB(skb);
> > > >         struct net *net = dev_net(skb->dev);
> > > > +       struct dst_entry *dst = skb_dst(skb);
> > > >         int extlen;
> > > >
> > > >         /*
> > > > @@ -834,6 +836,8 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
> > > >             !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
> > > >                                  ((skb_transport_header(skb)[1] + 1) << 3)))) {
> > > >  fail_and_free:
> > > > +               __IP6_INC_STATS(dev_net(dst->dev), idev,
> > > > +                               IPSTATS_MIB_INHDRERRORS);
> > >
> > > ip6_rcv_core, the only caller of ipv6_parse_hopopts, checks
> > > skb_valid_dst(skb) before deref. Does this need the same?
> >
> > Hi Willem,
> >
> > Actually, it looks like ipv6_parse_hopopts is doing things the right
> > way. __IP6_INC_STATS is called from ip6_rcv_core if ipv6_parse_hopopts
> > and the net is always taken from skb->dev (not dst) in HBH path. I'll
> > fix destopts to do the same.
>
> I don't entirely follow. The above code uses dev_net(dst->dev). Using
> local variable net, derived from dev_net(skb->dev), here definitely
> sounds good to me, if that's what you meant.

Yes, I'm thinking to just do dev_net(skb->dev) in all cases of
__IP6_INC_STATS for hopopts and destopts.

Tom
diff mbox series

Patch

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index ab5add0..f605e4e 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -288,9 +288,9 @@  static int ipv6_destopt_rcv(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
 	    !pskb_may_pull(skb, (skb_transport_offset(skb) +
 				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
+fail_and_free:
 		__IP6_INC_STATS(dev_net(dst->dev), idev,
 				IPSTATS_MIB_INHDRERRORS);
-fail_and_free:
 		kfree_skb(skb);
 		return -1;
 	}
@@ -820,8 +820,10 @@  static const struct tlvtype_proc tlvprochopopt_lst[] = {
 
 int ipv6_parse_hopopts(struct sk_buff *skb)
 {
+	struct inet6_dev *idev = __in6_dev_get(skb->dev);
 	struct inet6_skb_parm *opt = IP6CB(skb);
 	struct net *net = dev_net(skb->dev);
+	struct dst_entry *dst = skb_dst(skb);
 	int extlen;
 
 	/*
@@ -834,6 +836,8 @@  int ipv6_parse_hopopts(struct sk_buff *skb)
 	    !pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
 				 ((skb_transport_header(skb)[1] + 1) << 3)))) {
 fail_and_free:
+		__IP6_INC_STATS(dev_net(dst->dev), idev,
+				IPSTATS_MIB_INHDRERRORS);
 		kfree_skb(skb);
 		return -1;
 	}
@@ -850,6 +854,7 @@  int ipv6_parse_hopopts(struct sk_buff *skb)
 		opt->nhoff = sizeof(struct ipv6hdr);
 		return 1;
 	}
+	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
 	return -1;
 }