net sched: Pass the skb into change so it can access NETLINK_CB

cls_flow.c plays with uids and gids.  Unless I misread that
code it is possible for classifiers to depend on the specific uid and
gid values.  Therefore I need to know the user namespace of the
netlink socket that is installing the packet classifiers.  Pass
in the rtnetlink skb so I can access the NETLINK_CB of the passed
packet.  In particular I want access to sk_user_ns(NETLINK_CB(in_skb).ssk).

Pass in not the user namespace but the incomming rtnetlink skb into
the the classifier change routines as that is generally the more useful
parameter.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

include/net/sch_generic.h

@@ -188,7 +188,8 @@ struct tcf_proto_ops {
 
 	unsigned long		(*get)(struct tcf_proto*, u32 handle);
 	void			(*put)(struct tcf_proto*, unsigned long);
-	int			(*change)(struct tcf_proto*, unsigned long,
+	int			(*change)(struct sk_buff *,
+					struct tcf_proto*, unsigned long,
 					u32 handle, struct nlattr **,
 					unsigned long *);
 	int			(*delete)(struct tcf_proto*, unsigned long);

net/sched/cls_api.c

@@ -319,7 +319,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 		}
 	}
 
-	err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
+	err = tp->ops->change(skb, tp, cl, t->tcm_handle, tca, &fh);
 	if (err == 0) {
 		if (tp_created) {
 			spin_lock_bh(root_lock);

net/sched/cls_basic.c

@@ -162,7 +162,8 @@ static int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f,
 	return err;
 }
 
-static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle,
+static int basic_change(struct sk_buff *in_skb,
+			struct tcf_proto *tp, unsigned long base, u32 handle,
 			struct nlattr **tca, unsigned long *arg)
 {
 	int err;

net/sched/cls_cgroup.c

@@ -151,7 +151,8 @@ static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
 	[TCA_CGROUP_EMATCHES]	= { .type = NLA_NESTED },
 };
 
-static int cls_cgroup_change(struct tcf_proto *tp, unsigned long base,
+static int cls_cgroup_change(struct sk_buff *in_skb,
+			     struct tcf_proto *tp, unsigned long base,
 			     u32 handle, struct nlattr **tca,
 			     unsigned long *arg)
 {

net/sched/cls_flow.c

@@ -347,7 +347,8 @@ static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 	[TCA_FLOW_PERTURB]	= { .type = NLA_U32 },
 };
 
-static int flow_change(struct tcf_proto *tp, unsigned long base,
+static int flow_change(struct sk_buff *in_skb, 
+		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
 		       unsigned long *arg)
 {

net/sched/cls_fw.c

@@ -233,7 +233,8 @@ fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
 	return err;
 }
 
-static int fw_change(struct tcf_proto *tp, unsigned long base,
+static int fw_change(struct sk_buff *in_skb,
+		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle,
 		     struct nlattr **tca,
 		     unsigned long *arg)

net/sched/cls_route.c

@@ -427,7 +427,8 @@ static int route4_set_parms(struct tcf_proto *tp, unsigned long base,
 	return err;
 }
 
-static int route4_change(struct tcf_proto *tp, unsigned long base,
+static int route4_change(struct sk_buff *in_skb,
+		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle,
 		       struct nlattr **tca,
 		       unsigned long *arg)

net/sched/cls_rsvp.h

@@ -416,7 +416,8 @@ static const struct nla_policy rsvp_policy[TCA_RSVP_MAX + 1] = {
 	[TCA_RSVP_PINFO]	= { .len = sizeof(struct tc_rsvp_pinfo) },
 };
 
-static int rsvp_change(struct tcf_proto *tp, unsigned long base,
+static int rsvp_change(struct sk_buff *in_skb,
+		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle,
 		       struct nlattr **tca,
 		       unsigned long *arg)

net/sched/cls_tcindex.c

@@ -332,7 +332,8 @@ tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle,
 }
 
 static int
-tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
+tcindex_change(struct sk_buff *in_skb,
+	       struct tcf_proto *tp, unsigned long base, u32 handle,
 	       struct nlattr **tca, unsigned long *arg)
 {
 	struct nlattr *opt = tca[TCA_OPTIONS];

net/sched/cls_u32.c

@@ -544,7 +544,8 @@ static int u32_set_parms(struct tcf_proto *tp, unsigned long base,
 	return err;
 }
 
-static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle,
+static int u32_change(struct sk_buff *in_skb,
+		      struct tcf_proto *tp, unsigned long base, u32 handle,
 		      struct nlattr **tca,
 		      unsigned long *arg)
 {