tc_ctl_tfilter handles three netlink message types: RTM_NEWTFILTER,
RTM_DELTFILTER, RTM_GETTFILTER. However, implementation of this function
involves a lot of branching on specific message type because most of the
code is message-specific. This significantly complicates adding new
functionality and doesn't provide much benefit of code reuse.
Split tc_ctl_tfilter to three standalone functions that handle filter new,
delete and get requests.
The only truly protocol independent part of tc_ctl_tfilter is code that
looks up queue, class, and block. Refactor this code to standalone
tcf_block_find function that is used by all three new handlers.
Signed-off-by: Vlad Buslov
---
net/sched/cls_api.c | 438 +++-
1 file changed, 293 insertions(+), 145 deletions(-)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 1ed673f501c2..8dfbad1bddf5 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -436,6 +436,78 @@ static struct tcf_block *tcf_block_lookup(struct net *net,
u32 block_index)
return idr_find(&tn->idr, block_index);
}
+/* Find tcf block.
+ * Set q, parent, cl when appropriate.
+ */
+
+static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
+ u32 *parent, unsigned long *cl,
+ int ifindex, u32 block_index,
+ struct netlink_ext_ack *extack)
+{
+ struct tcf_block *block;
+
+ if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
+ block = tcf_block_lookup(net, block_index);
+ if (!block) {
+ NL_SET_ERR_MSG(extack, "Block of given index was not
found");
+ return ERR_PTR(-EINVAL);
+ }
+ } else {
+ const struct Qdisc_class_ops *cops;
+ struct net_device *dev;
+
+ /* Find link */
+ dev = __dev_get_by_index(net, ifindex);
+ if (!dev)
+ return ERR_PTR(-ENODEV);
+
+ /* Find qdisc */
+ if (!*parent) {
+ *q = dev->qdisc;
+ *parent = (*q)->handle;
+ } else {
+ *q = qdisc_lookup(dev, TC_H_MAJ(*parent));
+ if (!*q) {
+ NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't
exists");
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ /* Is it classful? */
+ cops = (*q)->ops->cl_ops;
+ if (!cops) {
+ NL_SET_ERR_MSG(extack, "Qdisc not classful");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!cops->tcf_block) {
+ NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+
+ /* Do we search for filter, attached to class? */
+ if (TC_H_MIN(*parent)) {
+ *cl = cops->find(*q, *parent);
+ if (*cl == 0) {
+ NL_SET_ERR_MSG(extack, "Specified class doesn't
exist");
+ return ERR_PTR(-ENOENT);
+ }
+ }
+
+ /* And the last stroke */
+ block = cops->tcf_block(*q, *cl, extack);
+ if (!block)
+ return ERR_PTR(-EINVAL);
+ if (tcf_block_shared(block)) {
+ NL_SET_ERR_MSG(extack, "This filter block is shared.
Please use the block index to manipulate the filters");
+ return ERR_PTR(-EOPNOTSUPP);
+ }
+ }
+
+ return block;
+}
+
static struct tcf_chain *tcf_block_chain_zero(struct tcf_block *block)
{
return list_first_entry(&block->chain_list, struct tcf_chain, list);
@@ -1002,9 +1074,7 @@ static void tfilter_notify_chain(struct net *net, struct
sk_buff *oskb,
q, parent, 0, event, false);
}
-/* Add/change/delete/get a filter node */
-
-static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
+static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
@@ -1025,8 +1095,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
int err;
int tp_created;
- if ((n->nlmsg_type != RTM_GETTFILTER) &&
- !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
+ if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
replay:
@@ -1044,24 +1113,13 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct
nlmsghdr *n,
cl = 0;
if (prio == 0) {
- switch (n->nlmsg_type) {
-
