[SKBUFF]: Merge common code between copy_skb_header and skb_clone

This patch creates a new function __copy_skb_header to merge the common
code between copy_skb_header and skb_clone.  Having two functions which
are largely the same is a source of wasted labour as well as confusion.

In fact the tc_verd stuff is almost certainly a bug since it's treated
differently in skb_clone compared to the callers of copy_skb_header
(skb_copy/pskb_copy/skb_copy_expand).

I've kept that difference in tact with a comment added asking for
clarification.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 944189d96323c9944089eded7b017cb1a3050599..758bbef506d33191399b4f7adb3cecb60e98da14 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -362,6 +362,44 @@ void kfree_skb(struct sk_buff *skb)
        __kfree_skb(skb);
 }
 
+static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
+{
+       new->tstamp             = old->tstamp;
+       new->dev                = old->dev;
+       new->transport_header   = old->transport_header;
+       new->network_header     = old->network_header;
+       new->mac_header         = old->mac_header;
+       new->dst                = dst_clone(old->dst);
+#ifdef CONFIG_INET
+       new->sp                 = secpath_get(old->sp);
+#endif
+       memcpy(new->cb, old->cb, sizeof(old->cb));
+       new->csum_start         = old->csum_start;
+       new->csum_offset        = old->csum_offset;
+       new->local_df           = old->local_df;
+       new->pkt_type           = old->pkt_type;
+       new->ip_summed          = old->ip_summed;
+       skb_copy_queue_mapping(new, old);
+       new->priority           = old->priority;
+#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
+       new->ipvs_property      = old->ipvs_property;
+#endif
+       new->protocol           = old->protocol;
+       new->mark               = old->mark;
+       __nf_copy(new, old);
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+       new->nf_trace           = old->nf_trace;
+#endif
+#ifdef CONFIG_NET_SCHED
+       new->tc_index           = old->tc_index;
+#ifdef CONFIG_NET_CLS_ACT
+       new->tc_verd            = old->tc_verd;
+#endif
+#endif
+       skb_copy_secmark(new, old);
+}
+
 /**
  *     skb_clone       -       duplicate an sk_buff
  *     @skb: buffer to clone
@@ -397,51 +435,22 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
 
        n->next = n->prev = NULL;
        n->sk = NULL;
-       C(tstamp);
-       C(dev);
-       C(transport_header);
-       C(network_header);
-       C(mac_header);
-       C(dst);
-       dst_clone(skb->dst);
-       C(sp);
-#ifdef CONFIG_INET
-       secpath_get(skb->sp);
-#endif
-       memcpy(n->cb, skb->cb, sizeof(skb->cb));
+       __copy_skb_header(n, skb);
+
        C(len);
        C(data_len);
        C(mac_len);
-       C(csum);
-       C(local_df);
        n->cloned = 1;
        n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len;
        n->nohdr = 0;
-       C(pkt_type);
-       C(ip_summed);
-       skb_copy_queue_mapping(n, skb);
-       C(priority);
-#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
-       C(ipvs_property);
-#endif
-       C(protocol);
        n->destructor = NULL;
-       C(mark);
-       __nf_copy(n, skb);
-#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
-    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
-       C(nf_trace);
-#endif
-#ifdef CONFIG_NET_SCHED
-       C(tc_index);
 #ifdef CONFIG_NET_CLS_ACT
-       n->tc_verd = SET_TC_VERD(skb->tc_verd,0);
+       /* FIXME What is this and why don't we do it in copy_skb_header? */
+       n->tc_verd = SET_TC_VERD(n->tc_verd,0);
        n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
        n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
        C(iif);
 #endif
-#endif
-       skb_copy_secmark(n, skb);
        C(truesize);
        atomic_set(&n->users, 1);
        C(head);
@@ -463,50 +472,15 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
         */
        unsigned long offset = new->data - old->data;
 #endif
-       new->sk         = NULL;
-       new->dev        = old->dev;
-       skb_copy_queue_mapping(new, old);
-       new->priority   = old->priority;
-       new->protocol   = old->protocol;
-       new->dst        = dst_clone(old->dst);
-#ifdef CONFIG_INET
-       new->sp         = secpath_get(old->sp);
-#endif
-       new->csum_start = old->csum_start;
-       new->csum_offset = old->csum_offset;
-       new->ip_summed = old->ip_summed;
-       new->transport_header = old->transport_header;
-       new->network_header   = old->network_header;
-       new->mac_header       = old->mac_header;
+
+       __copy_skb_header(new, old);
+
 #ifndef NET_SKBUFF_DATA_USES_OFFSET
        /* {transport,network,mac}_header are relative to skb->head */
        new->transport_header += offset;
        new->network_header   += offset;
        new->mac_header       += offset;
 #endif
-       memcpy(new->cb, old->cb, sizeof(old->cb));
-       new->local_df   = old->local_df;
-       new->fclone     = SKB_FCLONE_UNAVAILABLE;
-       new->pkt_type   = old->pkt_type;
-       new->tstamp     = old->tstamp;
-       new->destructor = NULL;
-       new->mark       = old->mark;
-       __nf_copy(new, old);
-#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
-    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
-       new->nf_trace   = old->nf_trace;
-#endif
-#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
-       new->ipvs_property = old->ipvs_property;
-#endif
-#ifdef CONFIG_NET_SCHED
-#ifdef CONFIG_NET_CLS_ACT
-       new->tc_verd = old->tc_verd;
-#endif
-       new->tc_index   = old->tc_index;
-#endif
-       skb_copy_secmark(new, old);
-       atomic_set(&new->users, 1);
        skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size;
        skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs;
        skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type;