sched: push TC filter protocol creation into a separate function

Make the long function tc_ctl_tfilter a little bit shorter and easier to
read. Also make the creation of filter proto symmetric to destruction.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 4efa4df..d378a0b 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/skbuff.h>
 #include <linux/init.h>
 #include <linux/kmod.h>
@@ -38,14 +39,14 @@ static DEFINE_RWLOCK(cls_mod_lock);
 
 /* Find classifier type by string name */
 
-static const struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
+static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
 {
        const struct tcf_proto_ops *t, *res = NULL;
 
        if (kind) {
                read_lock(&cls_mod_lock);
                list_for_each_entry(t, &tcf_proto_base, head) {
-                       if (nla_strcmp(kind, t->kind) == 0) {
+                       if (strcmp(kind, t->kind) == 0) {
                                if (try_module_get(t->owner))
                                        res = t;
                                break;
@@ -127,6 +128,56 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
        return first;
 }
 
+static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
+                                         u32 prio, u32 parent, struct Qdisc *q)
+{
+       struct tcf_proto *tp;
+       int err;
+
+       tp = kzalloc(sizeof(*tp), GFP_KERNEL);
+       if (!tp)
+               return ERR_PTR(-ENOBUFS);
+
+       err = -ENOENT;
+       tp->ops = tcf_proto_lookup_ops(kind);
+       if (!tp->ops) {
+#ifdef CONFIG_MODULES
+               rtnl_unlock();
+               request_module("cls_%s", kind);
+               rtnl_lock();
+               tp->ops = tcf_proto_lookup_ops(kind);
+               /* We dropped the RTNL semaphore in order to perform
+                * the module load. So, even if we succeeded in loading
+                * the module we have to replay the request. We indicate
+                * this using -EAGAIN.
+                */
+               if (tp->ops) {
+                       module_put(tp->ops->owner);
+                       err = -EAGAIN;
+               } else {
+                       err = -ENOENT;
+               }
+               goto errout;
+#endif
+       }
+       tp->classify = tp->ops->classify;
+       tp->protocol = protocol;
+       tp->prio = prio;
+       tp->classid = parent;
+       tp->q = q;
+
+       err = tp->ops->init(tp);
+       if (err) {
+               module_put(tp->ops->owner);
+               goto errout;
+       }
+       return tp;
+
+errout:
+       kfree(tp);
+       return ERR_PTR(err);
+}
+
 static bool tcf_proto_destroy(struct tcf_proto *tp, bool force)
 {
        if (tp->ops->destroy(tp, force)) {
@@ -164,7 +215,6 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n)
        struct tcf_proto __rcu **back;
        struct tcf_proto __rcu **chain;
        struct tcf_proto *tp;
-       const struct tcf_proto_ops *tp_ops;
        const struct Qdisc_class_ops *cops;
        unsigned long cl;
        unsigned long fh;
@@ -279,58 +329,16 @@ replay:
                    !(n->nlmsg_flags & NLM_F_CREATE))
                        goto errout;
 
+               if (!nprio)
+                       nprio = TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back)));
 
-               /* Create new proto tcf */
-
-               err = -ENOBUFS;
-               tp = kzalloc(sizeof(*tp), GFP_KERNEL);
-               if (tp == NULL)
-                       goto errout;
-               err = -ENOENT;
-               tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
-               if (tp_ops == NULL) {
-#ifdef CONFIG_MODULES
-                       struct nlattr *kind = tca[TCA_KIND];
-                       char name[IFNAMSIZ];
-
-                       if (kind != NULL &&
-                           nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
-                               rtnl_unlock();
-                               request_module("cls_%s", name);
-                               rtnl_lock();
-                               tp_ops = tcf_proto_lookup_ops(kind);
-                               /* We dropped the RTNL semaphore in order to
-                                * perform the module load.  So, even if we
-                                * succeeded in loading the module we have to
-                                * replay the request.  We indicate this using
-                                * -EAGAIN.
-                                */
-                               if (tp_ops != NULL) {
-                                       module_put(tp_ops->owner);
-                                       err = -EAGAIN;
-                               }
-                       }
-#endif
-                       kfree(tp);
+               tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
+                                     protocol, nprio, parent, q);
+               if (IS_ERR(tp)) {
+                       err = PTR_ERR(tp);
                        goto errout;
                }
-               tp->ops = tp_ops;
-               tp->protocol = protocol;
-               tp->prio = nprio ? :
-                              TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back)));
-               tp->q = q;
-               tp->classify = tp_ops->classify;
-               tp->classid = parent;
-
-               err = tp_ops->init(tp);
-               if (err != 0) {
-                       module_put(tp_ops->owner);
-                       kfree(tp);
-                       goto errout;
-               }
-
                tp_created = 1;
-
        } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
                goto errout;