[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>

1 files changed, 45 insertions, 71 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 944189d96323..758bbef506d3 100644
--- 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;