net_sched: optimize tcf_match_indev()

tcf_match_indev() is called in fast path, it is not wise to
search for a netdev by ifindex and then compare by its name,
just compare the ifindex.

Also, dev->name could be changed by user-space, therefore
the match would be always fail, but dev->ifindex could
be consistent.

BTW, this will also save some bytes from the core struct of u32.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 50ea079..a2441fb 100644 (file)
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -338,27 +338,27 @@ static inline int tcf_valid_offset(const struct sk_buff *skb,
 #include <net/net_namespace.h>
 
 static inline int
-tcf_change_indev(struct tcf_proto *tp, char *indev, struct nlattr *indev_tlv)
+tcf_change_indev(struct net *net, struct nlattr *indev_tlv)
 {
+       char indev[IFNAMSIZ];
+       struct net_device *dev;
+
        if (nla_strlcpy(indev, indev_tlv, IFNAMSIZ) >= IFNAMSIZ)
                return -EINVAL;
-       return 0;
+       dev = __dev_get_by_name(net, indev);
+       if (!dev)
+               return -ENODEV;
+       return dev->ifindex;
 }
 
-static inline int
-tcf_match_indev(struct sk_buff *skb, char *indev)
+static inline bool
+tcf_match_indev(struct sk_buff *skb, int ifindex)
 {
-       struct net_device *dev;
-
-       if (indev[0]) {
-               if  (!skb->skb_iif)
-                       return 0;
-               dev = __dev_get_by_index(dev_net(skb->dev), skb->skb_iif);
-               if (!dev || strcmp(indev, dev->name))
-                       return 0;
-       }
-
-       return 1;
+       if (!ifindex)
+               return true;
+       if  (!skb->skb_iif)
+               return false;
+       return ifindex == skb->skb_iif;
 }
 #endif /* CONFIG_NET_CLS_IND */
 

diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index d605285..ca662aa 100644 (file)
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -41,7 +41,7 @@ struct fw_filter {
        u32                     id;
        struct tcf_result       res;
 #ifdef CONFIG_NET_CLS_IND
-       char                    indev[IFNAMSIZ];
+       int                     ifindex;
 #endif /* CONFIG_NET_CLS_IND */
        struct tcf_exts         exts;
 };
@@ -86,7 +86,7 @@ static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
                        if (f->id == id) {
                                *res = f->res;
 #ifdef CONFIG_NET_CLS_IND
-                               if (!tcf_match_indev(skb, f->indev))
+                               if (!tcf_match_indev(skb, f->ifindex))
                                        continue;
 #endif /* CONFIG_NET_CLS_IND */
                                r = tcf_exts_exec(skb, &f->exts, res);
@@ -207,9 +207,11 @@ fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
 
 #ifdef CONFIG_NET_CLS_IND
        if (tb[TCA_FW_INDEV]) {
-               err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
-               if (err < 0)
+               int ret;
+               ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
+               if (ret < 0)
                        goto errout;
+               f->ifindex = ret;
        }
 #endif /* CONFIG_NET_CLS_IND */
 
@@ -348,9 +350,12 @@ static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
            nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
                goto nla_put_failure;
 #ifdef CONFIG_NET_CLS_IND
-       if (strlen(f->indev) &&
-           nla_put_string(skb, TCA_FW_INDEV, f->indev))
-               goto nla_put_failure;
+       if (f->ifindex) {
+               struct net_device *dev;
+               dev = __dev_get_by_index(net, f->ifindex);
+               if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
+                       goto nla_put_failure;
+       }
 #endif /* CONFIG_NET_CLS_IND */
        if (head->mask != 0xFFFFFFFF &&
            nla_put_u32(skb, TCA_FW_MASK, head->mask))

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index e25411a..f509b79 100644 (file)
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -48,7 +48,7 @@ struct tc_u_knode {
        struct tc_u_hnode       *ht_up;
        struct tcf_exts         exts;
 #ifdef CONFIG_NET_CLS_IND
-       char                     indev[IFNAMSIZ];
+       int                     ifindex;
 #endif
        u8                      fshift;
        struct tcf_result       res;
@@ -152,7 +152,7 @@ check_terminal:
 
                                *res = n->res;
 #ifdef CONFIG_NET_CLS_IND
-                               if (!tcf_match_indev(skb, n->indev)) {
+                               if (!tcf_match_indev(skb, n->ifindex)) {
                                        n = n->next;
                                        goto next_knode;
                                }
@@ -527,9 +527,11 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 
 #ifdef CONFIG_NET_CLS_IND
        if (tb[TCA_U32_INDEV]) {
-               err = tcf_change_indev(tp, n->indev, tb[TCA_U32_INDEV]);
-               if (err < 0)
+               int ret;
+               ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
+               if (ret < 0)
                        goto errout;
+               n->ifindex = ret;
        }
 #endif
        tcf_exts_change(tp, &n->exts, &e);
@@ -760,9 +762,12 @@ static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
                        goto nla_put_failure;
 
 #ifdef CONFIG_NET_CLS_IND
-               if (strlen(n->indev) &&
-                   nla_put_string(skb, TCA_U32_INDEV, n->indev))
-                       goto nla_put_failure;
+               if (n->ifindex) {
+                       struct net_device *dev;
+                       dev = __dev_get_by_index(net, n->ifindex);
+                       if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
+                               goto nla_put_failure;
+               }
 #endif
 #ifdef CONFIG_CLS_U32_PERF
                if (nla_put(skb, TCA_U32_PCNT,