skb_checksum_help is designed to compute the Internet Checksum only. To
avoid duplicating code when other checksumming algorithms (e.g. crc32c)
are used, separate common part from RFC1624-specific part.
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Signed-off-by: Davide Caratti <dcaratti@xxxxxxxxxx>
---
net/core/dev.c | 51 +++++++++++++++++++++++++++++++++++----------------
1 file changed, 35 insertions(+), 16 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index ad5959e..6742160 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2532,13 +2532,36 @@ static void skb_warn_bad_offload(const struct sk_buff *skb)
skb_shinfo(skb)->gso_type, skb->ip_summed);
}
-/*
- * Invalidate hardware checksum when packet is to be mangled, and
+/* compute 16-bit RFC1624 checksum and store it at skb->data + offset */
+static int skb_rfc1624_csum(struct sk_buff *skb, int offset)
+{
+ __wsum csum;
+ int ret = 0;
+
+ csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+ offset += skb->csum_offset;
+ BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
+
+ if (skb_cloned(skb) &&
+ !skb_clone_writable(skb, offset + sizeof(__sum16))) {
+ ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+ if (ret)
+ goto out;
+ }
+ *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
+out:
+ return ret;
+}
+
+/* Invalidate hardware checksum when packet is to be mangled, and
* complete checksum manually on outgoing path.
+ * @skb - buffer that needs checksum
+ * @csum_algo(skb, offset) - function used to compute the checksum
*/
-int skb_checksum_help(struct sk_buff *skb)
+static int __skb_checksum_help(struct sk_buff *skb,
+ int (*csum_algo)(struct sk_buff *, int))
{
- __wsum csum;
int ret = 0, offset;
if (skb->ip_summed == CHECKSUM_COMPLETE)
@@ -2560,24 +2583,20 @@ int skb_checksum_help(struct sk_buff *skb)
offset = skb_checksum_start_offset(skb);
BUG_ON(offset >= skb_headlen(skb));
- csum = skb_checksum(skb, offset, skb->len - offset, 0);
-
- offset += skb->csum_offset;
- BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
-
- if (skb_cloned(skb) &&
- !skb_clone_writable(skb, offset + sizeof(__sum16))) {
- ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
- if (ret)
- goto out;
- }
- *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
+ ret = csum_algo(skb, offset);
+ if (ret)
+ goto out;
out_set_summed:
skb->ip_summed = CHECKSUM_NONE;
out:
return ret;
}
+
+int skb_checksum_help(struct sk_buff *skb)
+{
+ return __skb_checksum_help(skb, skb_rfc1624_csum);
+}
EXPORT_SYMBOL(skb_checksum_help);
__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
--
2.7.4
--
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