net: more accurate checksumming in validate_xmit_skb()
skb_csum_hwoffload_help() uses netdev features and skb->csum_not_inet to
determine if skb needs software computation of Internet Checksum or crc32c
(or nothing, if this computation can be done by the hardware). Use it in
place of skb_checksum_help() in validate_xmit_skb() to avoid corruption
of non-GSO SCTP packets having skb->ip_summed equal to CHECKSUM_PARTIAL.
While at it, remove references to skb_csum_off_chk* functions, since they
are not present anymore in Linux _ see commit cf53b1da73bd ("Revert
"net: Add driver helper functions to determine checksum offloadability"").
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a43d208..43d7ca07 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -162,14 +162,11 @@
*
* NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
* NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
- * checksum offload capability. If a device has limited checksum capabilities
- * (for instance can only perform NETIF_F_IP_CSUM or NETIF_F_IPV6_CSUM as
- * described above) a helper function can be called to resolve
- * CHECKSUM_PARTIAL. The helper functions are skb_csum_off_chk*. The helper
- * function takes a spec argument that describes the protocol layer that is
- * supported for checksum offload and can be called for each packet. If a
- * packet does not match the specification for offload, skb_checksum_help
- * is called to resolve the checksum.
+ * checksum offload capability.
+ * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
+ * on network device checksumming capabilities: if a packet does not match
+ * them, skb_checksum_help or skb_crc32c_help (depending on the value of
+ * csum_not_inet, see item D.) is called to resolve the checksum.
*
* CHECKSUM_NONE:
*